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Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents):
Revision 1.76 by jsr166, Fri Nov 9 03:30:03 2012 UTC vs.
Revision 1.123 by jsr166, Fri Feb 27 21:08:53 2015 UTC

# Line 6 | Line 6
6  
7   package jsr166e;
8  
9 < import java.util.Comparator;
9 > import jsr166e.ForkJoinPool;
10 >
11 > import java.io.ObjectStreamField;
12 > import java.io.Serializable;
13 > import java.lang.reflect.ParameterizedType;
14 > import java.lang.reflect.Type;
15 > import java.util.AbstractMap;
16   import java.util.Arrays;
11 import java.util.Map;
12 import java.util.Set;
17   import java.util.Collection;
18 < import java.util.AbstractMap;
19 < import java.util.AbstractSet;
16 < import java.util.AbstractCollection;
17 < import java.util.Hashtable;
18 > import java.util.ConcurrentModificationException;
19 > import java.util.Enumeration;
20   import java.util.HashMap;
21 + import java.util.Hashtable;
22   import java.util.Iterator;
23 < import java.util.Enumeration;
21 < import java.util.ConcurrentModificationException;
23 > import java.util.Map;
24   import java.util.NoSuchElementException;
25 + import java.util.Set;
26   import java.util.concurrent.ConcurrentMap;
24 import java.util.concurrent.ThreadLocalRandom;
25 import java.util.concurrent.locks.LockSupport;
26 import java.util.concurrent.locks.AbstractQueuedSynchronizer;
27   import java.util.concurrent.atomic.AtomicReference;
28 <
29 < import java.io.Serializable;
28 > import java.util.concurrent.atomic.AtomicInteger;
29 > import java.util.concurrent.locks.LockSupport;
30 > import java.util.concurrent.locks.ReentrantLock;
31  
32   /**
33   * A hash table supporting full concurrency of retrievals and
# Line 40 | Line 41 | import java.io.Serializable;
41   * interoperable with {@code Hashtable} in programs that rely on its
42   * thread safety but not on its synchronization details.
43   *
44 < * <p> Retrieval operations (including {@code get}) generally do not
44 > * <p>Retrieval operations (including {@code get}) generally do not
45   * block, so may overlap with update operations (including {@code put}
46   * and {@code remove}). Retrievals reflect the results of the most
47   * recently <em>completed</em> update operations holding upon their
# Line 61 | Line 62 | import java.io.Serializable;
62   * that may be adequate for monitoring or estimation purposes, but not
63   * for program control.
64   *
65 < * <p> The table is dynamically expanded when there are too many
65 > * <p>The table is dynamically expanded when there are too many
66   * collisions (i.e., keys that have distinct hash codes but fall into
67   * the same slot modulo the table size), with the expected average
68   * effect of maintaining roughly two bins per mapping (corresponding
# Line 80 | Line 81 | import java.io.Serializable;
81   * expected {@code concurrencyLevel} as an additional hint for
82   * internal sizing.  Note that using many keys with exactly the same
83   * {@code hashCode()} is a sure way to slow down performance of any
84 < * hash table.
84 > * hash table. To ameliorate impact, when keys are {@link Comparable},
85 > * this class may use comparison order among keys to help break ties.
86   *
87 < * <p> A {@link Set} projection of a ConcurrentHashMapV8 may be created
87 > * <p>A {@link Set} projection of a ConcurrentHashMapV8 may be created
88   * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
89   * (using {@link #keySet(Object)} when only keys are of interest, and the
90   * mapped values are (perhaps transiently) not used or all take the
91   * same mapping value.
92   *
91 * <p> A ConcurrentHashMapV8 can be used as scalable frequency map (a
92 * form of histogram or multiset) by using {@link LongAdder} values
93 * and initializing via {@link #computeIfAbsent}. For example, to add
94 * a count to a {@code ConcurrentHashMapV8<String,LongAdder> freqs}, you
95 * can use {@code freqs.computeIfAbsent(k -> new
96 * LongAdder()).increment();}
97 *
93   * <p>This class and its views and iterators implement all of the
94   * <em>optional</em> methods of the {@link Map} and {@link Iterator}
95   * interfaces.
96   *
97 < * <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
97 > * <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
98   * does <em>not</em> allow {@code null} to be used as a key or value.
99   *
100 < * <p>ConcurrentHashMapV8s support parallel operations using the {@link
101 < * ForkJoinPool#commonPool}. (Tasks that may be used in other contexts
102 < * are available in class {@link ForkJoinTasks}). These operations are
103 < * designed to be safely, and often sensibly, applied even with maps
104 < * that are being concurrently updated by other threads; for example,
105 < * when computing a snapshot summary of the values in a shared
106 < * registry.  There are three kinds of operation, each with four
107 < * forms, accepting functions with Keys, Values, Entries, and (Key,
108 < * Value) arguments and/or return values. (The first three forms are
109 < * also available via the {@link #keySet()}, {@link #values()} and
110 < * {@link #entrySet()} views). Because the elements of a
111 < * ConcurrentHashMapV8 are not ordered in any particular way, and may be
112 < * processed in different orders in different parallel executions, the
113 < * correctness of supplied functions should not depend on any
114 < * ordering, or on any other objects or values that may transiently
120 < * change while computation is in progress; and except for forEach
121 < * actions, should ideally be side-effect-free.
100 > * <p>ConcurrentHashMapV8s support a set of sequential and parallel bulk
101 > * operations that are designed
102 > * to be safely, and often sensibly, applied even with maps that are
103 > * being concurrently updated by other threads; for example, when
104 > * computing a snapshot summary of the values in a shared registry.
105 > * There are three kinds of operation, each with four forms, accepting
106 > * functions with Keys, Values, Entries, and (Key, Value) arguments
107 > * and/or return values. Because the elements of a ConcurrentHashMapV8
108 > * are not ordered in any particular way, and may be processed in
109 > * different orders in different parallel executions, the correctness
110 > * of supplied functions should not depend on any ordering, or on any
111 > * other objects or values that may transiently change while
112 > * computation is in progress; and except for forEach actions, should
113 > * ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
114 > * objects do not support method {@code setValue}.
115   *
116   * <ul>
117   * <li> forEach: Perform a given action on each element.
# Line 145 | Line 138 | import java.io.Serializable;
138   * <li> Reductions to scalar doubles, longs, and ints, using a
139   * given basis value.</li>
140   *
148 * </li>
141   * </ul>
142 + * </li>
143   * </ul>
144   *
145 + * <p>These bulk operations accept a {@code parallelismThreshold}
146 + * argument. Methods proceed sequentially if the current map size is
147 + * estimated to be less than the given threshold. Using a value of
148 + * {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
149 + * of {@code 1} results in maximal parallelism by partitioning into
150 + * enough subtasks to fully utilize the {@link
151 + * ForkJoinPool#commonPool()} that is used for all parallel
152 + * computations. Normally, you would initially choose one of these
153 + * extreme values, and then measure performance of using in-between
154 + * values that trade off overhead versus throughput.
155 + *
156   * <p>The concurrency properties of bulk operations follow
157   * from those of ConcurrentHashMapV8: Any non-null result returned
158   * from {@code get(key)} and related access methods bears a
# Line 184 | Line 188 | import java.io.Serializable;
188   * arguments can be supplied using {@code new
189   * AbstractMap.SimpleEntry(k,v)}.
190   *
191 < * <p> Bulk operations may complete abruptly, throwing an
191 > * <p>Bulk operations may complete abruptly, throwing an
192   * exception encountered in the application of a supplied
193   * function. Bear in mind when handling such exceptions that other
194   * concurrently executing functions could also have thrown
195   * exceptions, or would have done so if the first exception had
196   * not occurred.
197   *
198 < * <p>Parallel speedups for bulk operations compared to sequential
199 < * processing are common but not guaranteed.  Operations involving
200 < * brief functions on small maps may execute more slowly than
201 < * sequential loops if the underlying work to parallelize the
202 < * computation is more expensive than the computation itself.
203 < * Similarly, parallelization may not lead to much actual parallelism
204 < * if all processors are busy performing unrelated tasks.
198 > * <p>Speedups for parallel compared to sequential forms are common
199 > * but not guaranteed.  Parallel operations involving brief functions
200 > * on small maps may execute more slowly than sequential forms if the
201 > * underlying work to parallelize the computation is more expensive
202 > * than the computation itself.  Similarly, parallelization may not
203 > * lead to much actual parallelism if all processors are busy
204 > * performing unrelated tasks.
205   *
206 < * <p> All arguments to all task methods must be non-null.
206 > * <p>All arguments to all task methods must be non-null.
207   *
208   * <p><em>jsr166e note: During transition, this class
209   * uses nested functional interfaces with different names but the
210 < * same forms as those expected for JDK8.<em>
210 > * same forms as those expected for JDK8.</em>
211   *
212   * <p>This class is a member of the
213   * <a href="{@docRoot}/../technotes/guides/collections/index.html">
# Line 214 | Line 218 | import java.io.Serializable;
218   * @param <K> the type of keys maintained by this map
219   * @param <V> the type of mapped values
220   */
221 < public class ConcurrentHashMapV8<K, V>
222 <    implements ConcurrentMap<K, V>, Serializable {
221 > public class ConcurrentHashMapV8<K,V> extends AbstractMap<K,V>
222 >    implements ConcurrentMap<K,V>, Serializable {
223      private static final long serialVersionUID = 7249069246763182397L;
224  
225      /**
226 <     * A partitionable iterator. A Spliterator can be traversed
227 <     * directly, but can also be partitioned (before traversal) by
228 <     * creating another Spliterator that covers a non-overlapping
225 <     * portion of the elements, and so may be amenable to parallel
226 <     * execution.
227 <     *
228 <     * <p> This interface exports a subset of expected JDK8
229 <     * functionality.
230 <     *
231 <     * <p>Sample usage: Here is one (of the several) ways to compute
232 <     * the sum of the values held in a map using the ForkJoin
233 <     * framework. As illustrated here, Spliterators are well suited to
234 <     * designs in which a task repeatedly splits off half its work
235 <     * into forked subtasks until small enough to process directly,
236 <     * and then joins these subtasks. Variants of this style can also
237 <     * be used in completion-based designs.
238 <     *
239 <     * <pre>
240 <     * {@code ConcurrentHashMapV8<String, Long> m = ...
241 <     * // split as if have 8 * parallelism, for load balance
242 <     * int n = m.size();
243 <     * int p = aForkJoinPool.getParallelism() * 8;
244 <     * int split = (n < p)? n : p;
245 <     * long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
246 <     * // ...
247 <     * static class SumValues extends RecursiveTask<Long> {
248 <     *   final Spliterator<Long> s;
249 <     *   final int split;             // split while > 1
250 <     *   final SumValues nextJoin;    // records forked subtasks to join
251 <     *   SumValues(Spliterator<Long> s, int depth, SumValues nextJoin) {
252 <     *     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
253 <     *   }
254 <     *   public Long compute() {
255 <     *     long sum = 0;
256 <     *     SumValues subtasks = null; // fork subtasks
257 <     *     for (int s = split >>> 1; s > 0; s >>>= 1)
258 <     *       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
259 <     *     while (s.hasNext())        // directly process remaining elements
260 <     *       sum += s.next();
261 <     *     for (SumValues t = subtasks; t != null; t = t.nextJoin)
262 <     *       sum += t.join();         // collect subtask results
263 <     *     return sum;
264 <     *   }
265 <     * }
266 <     * }</pre>
226 >     * An object for traversing and partitioning elements of a source.
227 >     * This interface provides a subset of the functionality of JDK8
228 >     * java.util.Spliterator.
229       */
230 <    public static interface Spliterator<T> extends Iterator<T> {
230 >    public static interface ConcurrentHashMapSpliterator<T> {
231          /**
232 <         * Returns a Spliterator covering approximately half of the
233 <         * elements, guaranteed not to overlap with those subsequently
234 <         * returned by this Spliterator.  After invoking this method,
235 <         * the current Spliterator will <em>not</em> produce any of
236 <         * the elements of the returned Spliterator, but the two
237 <         * Spliterators together will produce all of the elements that
238 <         * would have been produced by this Spliterator had this
239 <         * method not been called. The exact number of elements
240 <         * produced by the returned Spliterator is not guaranteed, and
279 <         * may be zero (i.e., with {@code hasNext()} reporting {@code
280 <         * false}) if this Spliterator cannot be further split.
281 <         *
282 <         * @return a Spliterator covering approximately half of the
283 <         * elements
284 <         * @throws IllegalStateException if this Spliterator has
285 <         * already commenced traversing elements
232 >         * If possible, returns a new spliterator covering
233 >         * approximately one half of the elements, which will not be
234 >         * covered by this spliterator. Returns null if cannot be
235 >         * split.
236 >         */
237 >        ConcurrentHashMapSpliterator<T> trySplit();
238 >        /**
239 >         * Returns an estimate of the number of elements covered by
240 >         * this Spliterator.
241           */
242 <        Spliterator<T> split();
242 >        long estimateSize();
243 >
244 >        /** Applies the action to each untraversed element */
245 >        void forEachRemaining(Action<? super T> action);
246 >        /** If an element remains, applies the action and returns true. */
247 >        boolean tryAdvance(Action<? super T> action);
248      }
249  
250 +    // Sams
251 +    /** Interface describing a void action of one argument */
252 +    public interface Action<A> { void apply(A a); }
253 +    /** Interface describing a void action of two arguments */
254 +    public interface BiAction<A,B> { void apply(A a, B b); }
255 +    /** Interface describing a function of one argument */
256 +    public interface Fun<A,T> { T apply(A a); }
257 +    /** Interface describing a function of two arguments */
258 +    public interface BiFun<A,B,T> { T apply(A a, B b); }
259 +    /** Interface describing a function mapping its argument to a double */
260 +    public interface ObjectToDouble<A> { double apply(A a); }
261 +    /** Interface describing a function mapping its argument to a long */
262 +    public interface ObjectToLong<A> { long apply(A a); }
263 +    /** Interface describing a function mapping its argument to an int */
264 +    public interface ObjectToInt<A> {int apply(A a); }
265 +    /** Interface describing a function mapping two arguments to a double */
266 +    public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
267 +    /** Interface describing a function mapping two arguments to a long */
268 +    public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
269 +    /** Interface describing a function mapping two arguments to an int */
270 +    public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
271 +    /** Interface describing a function mapping two doubles to a double */
272 +    public interface DoubleByDoubleToDouble { double apply(double a, double b); }
273 +    /** Interface describing a function mapping two longs to a long */
274 +    public interface LongByLongToLong { long apply(long a, long b); }
275 +    /** Interface describing a function mapping two ints to an int */
276 +    public interface IntByIntToInt { int apply(int a, int b); }
277 +
278  
279      /*
280       * Overview:
# Line 298 | Line 286 | public class ConcurrentHashMapV8<K, V>
286       * the same or better than java.util.HashMap, and to support high
287       * initial insertion rates on an empty table by many threads.
288       *
289 <     * Each key-value mapping is held in a Node.  Because Node fields
290 <     * can contain special values, they are defined using plain Object
291 <     * types. Similarly in turn, all internal methods that use them
292 <     * work off Object types. And similarly, so do the internal
293 <     * methods of auxiliary iterator and view classes.  All public
294 <     * generic typed methods relay in/out of these internal methods,
295 <     * supplying null-checks and casts as needed. This also allows
296 <     * many of the public methods to be factored into a smaller number
297 <     * of internal methods (although sadly not so for the five
298 <     * variants of put-related operations). The validation-based
299 <     * approach explained below leads to a lot of code sprawl because
300 <     * retry-control precludes factoring into smaller methods.
289 >     * This map usually acts as a binned (bucketed) hash table.  Each
290 >     * key-value mapping is held in a Node.  Most nodes are instances
291 >     * of the basic Node class with hash, key, value, and next
292 >     * fields. However, various subclasses exist: TreeNodes are
293 >     * arranged in balanced trees, not lists.  TreeBins hold the roots
294 >     * of sets of TreeNodes. ForwardingNodes are placed at the heads
295 >     * of bins during resizing. ReservationNodes are used as
296 >     * placeholders while establishing values in computeIfAbsent and
297 >     * related methods.  The types TreeBin, ForwardingNode, and
298 >     * ReservationNode do not hold normal user keys, values, or
299 >     * hashes, and are readily distinguishable during search etc
300 >     * because they have negative hash fields and null key and value
301 >     * fields. (These special nodes are either uncommon or transient,
302 >     * so the impact of carrying around some unused fields is
303 >     * insignificant.)
304       *
305       * The table is lazily initialized to a power-of-two size upon the
306       * first insertion.  Each bin in the table normally contains a
# Line 317 | Line 308 | public class ConcurrentHashMapV8<K, V>
308       * Table accesses require volatile/atomic reads, writes, and
309       * CASes.  Because there is no other way to arrange this without
310       * adding further indirections, we use intrinsics
311 <     * (sun.misc.Unsafe) operations.  The lists of nodes within bins
312 <     * are always accurately traversable under volatile reads, so long
313 <     * as lookups check hash code and non-nullness of value before
314 <     * checking key equality.
315 <     *
316 <     * We use the top two bits of Node hash fields for control
326 <     * purposes -- they are available anyway because of addressing
327 <     * constraints.  As explained further below, these top bits are
328 <     * used as follows:
329 <     *  00 - Normal
330 <     *  01 - Locked
331 <     *  11 - Locked and may have a thread waiting for lock
332 <     *  10 - Node is a forwarding node
333 <     *
334 <     * The lower 30 bits of each Node's hash field contain a
335 <     * transformation of the key's hash code, except for forwarding
336 <     * nodes, for which the lower bits are zero (and so always have
337 <     * hash field == MOVED).
311 >     * (sun.misc.Unsafe) operations.
312 >     *
313 >     * We use the top (sign) bit of Node hash fields for control
314 >     * purposes -- it is available anyway because of addressing
315 >     * constraints.  Nodes with negative hash fields are specially
316 >     * handled or ignored in map methods.
317       *
318       * Insertion (via put or its variants) of the first node in an
319       * empty bin is performed by just CASing it to the bin.  This is
# Line 343 | Line 322 | public class ConcurrentHashMapV8<K, V>
322       * delete, and replace) require locks.  We do not want to waste
323       * the space required to associate a distinct lock object with
324       * each bin, so instead use the first node of a bin list itself as
325 <     * a lock. Blocking support for these locks relies on the builtin
326 <     * "synchronized" monitors.  However, we also need a tryLock
348 <     * construction, so we overlay these by using bits of the Node
349 <     * hash field for lock control (see above), and so normally use
350 <     * builtin monitors only for blocking and signalling using
351 <     * wait/notifyAll constructions. See Node.tryAwaitLock.
325 >     * a lock. Locking support for these locks relies on builtin
326 >     * "synchronized" monitors.
327       *
328       * Using the first node of a list as a lock does not by itself
329       * suffice though: When a node is locked, any update must first
330       * validate that it is still the first node after locking it, and
331       * retry if not. Because new nodes are always appended to lists,
332       * once a node is first in a bin, it remains first until deleted
333 <     * or the bin becomes invalidated (upon resizing).  However,
359 <     * operations that only conditionally update may inspect nodes
360 <     * until the point of update. This is a converse of sorts to the
361 <     * lazy locking technique described by Herlihy & Shavit.
333 >     * or the bin becomes invalidated (upon resizing).
334       *
335       * The main disadvantage of per-bin locks is that other update
336       * operations on other nodes in a bin list protected by the same
# Line 391 | Line 363 | public class ConcurrentHashMapV8<K, V>
363       * sometimes deviate significantly from uniform randomness.  This
364       * includes the case when N > (1<<30), so some keys MUST collide.
365       * Similarly for dumb or hostile usages in which multiple keys are
366 <     * designed to have identical hash codes. Also, although we guard
367 <     * against the worst effects of this (see method spread), sets of
368 <     * hashes may differ only in bits that do not impact their bin
369 <     * index for a given power-of-two mask.  So we use a secondary
370 <     * strategy that applies when the number of nodes in a bin exceeds
371 <     * a threshold, and at least one of the keys implements
400 <     * Comparable.  These TreeBins use a balanced tree to hold nodes
401 <     * (a specialized form of red-black trees), bounding search time
402 <     * to O(log N).  Each search step in a TreeBin is around twice as
366 >     * designed to have identical hash codes or ones that differs only
367 >     * in masked-out high bits. So we use a secondary strategy that
368 >     * applies when the number of nodes in a bin exceeds a
369 >     * threshold. These TreeBins use a balanced tree to hold nodes (a
370 >     * specialized form of red-black trees), bounding search time to
371 >     * O(log N).  Each search step in a TreeBin is at least twice as
372       * slow as in a regular list, but given that N cannot exceed
373       * (1<<64) (before running out of addresses) this bounds search
374       * steps, lock hold times, etc, to reasonable constants (roughly
# Line 410 | Line 379 | public class ConcurrentHashMapV8<K, V>
379       * iterators in the same way.
380       *
381       * The table is resized when occupancy exceeds a percentage
382 <     * threshold (nominally, 0.75, but see below).  Only a single
383 <     * thread performs the resize (using field "sizeCtl", to arrange
384 <     * exclusion), but the table otherwise remains usable for reads
385 <     * and updates. Resizing proceeds by transferring bins, one by
386 <     * one, from the table to the next table.  Because we are using
387 <     * power-of-two expansion, the elements from each bin must either
388 <     * stay at same index, or move with a power of two offset. We
389 <     * eliminate unnecessary node creation by catching cases where old
390 <     * nodes can be reused because their next fields won't change.  On
391 <     * average, only about one-sixth of them need cloning when a table
392 <     * doubles. The nodes they replace will be garbage collectable as
393 <     * soon as they are no longer referenced by any reader thread that
394 <     * may be in the midst of concurrently traversing table.  Upon
395 <     * transfer, the old table bin contains only a special forwarding
396 <     * node (with hash field "MOVED") that contains the next table as
397 <     * its key. On encountering a forwarding node, access and update
398 <     * operations restart, using the new table.
399 <     *
400 <     * Each bin transfer requires its bin lock. However, unlike other
401 <     * cases, a transfer can skip a bin if it fails to acquire its
402 <     * lock, and revisit it later (unless it is a TreeBin). Method
403 <     * rebuild maintains a buffer of TRANSFER_BUFFER_SIZE bins that
404 <     * have been skipped because of failure to acquire a lock, and
405 <     * blocks only if none are available (i.e., only very rarely).
406 <     * The transfer operation must also ensure that all accessible
407 <     * bins in both the old and new table are usable by any traversal.
408 <     * When there are no lock acquisition failures, this is arranged
409 <     * simply by proceeding from the last bin (table.length - 1) up
410 <     * towards the first.  Upon seeing a forwarding node, traversals
411 <     * (see class Iter) arrange to move to the new table
412 <     * without revisiting nodes.  However, when any node is skipped
413 <     * during a transfer, all earlier table bins may have become
414 <     * visible, so are initialized with a reverse-forwarding node back
415 <     * to the old table until the new ones are established. (This
416 <     * sometimes requires transiently locking a forwarding node, which
417 <     * is possible under the above encoding.) These more expensive
418 <     * mechanics trigger only when necessary.
382 >     * threshold (nominally, 0.75, but see below).  Any thread
383 >     * noticing an overfull bin may assist in resizing after the
384 >     * initiating thread allocates and sets up the replacement array.
385 >     * However, rather than stalling, these other threads may proceed
386 >     * with insertions etc.  The use of TreeBins shields us from the
387 >     * worst case effects of overfilling while resizes are in
388 >     * progress.  Resizing proceeds by transferring bins, one by one,
389 >     * from the table to the next table. However, threads claim small
390 >     * blocks of indices to transfer (via field transferIndex) before
391 >     * doing so, reducing contention.  A generation stamp in field
392 >     * sizeCtl ensures that resizings do not overlap. Because we are
393 >     * using power-of-two expansion, the elements from each bin must
394 >     * either stay at same index, or move with a power of two
395 >     * offset. We eliminate unnecessary node creation by catching
396 >     * cases where old nodes can be reused because their next fields
397 >     * won't change.  On average, only about one-sixth of them need
398 >     * cloning when a table doubles. The nodes they replace will be
399 >     * garbage collectable as soon as they are no longer referenced by
400 >     * any reader thread that may be in the midst of concurrently
401 >     * traversing table.  Upon transfer, the old table bin contains
402 >     * only a special forwarding node (with hash field "MOVED") that
403 >     * contains the next table as its key. On encountering a
404 >     * forwarding node, access and update operations restart, using
405 >     * the new table.
406 >     *
407 >     * Each bin transfer requires its bin lock, which can stall
408 >     * waiting for locks while resizing. However, because other
409 >     * threads can join in and help resize rather than contend for
410 >     * locks, average aggregate waits become shorter as resizing
411 >     * progresses.  The transfer operation must also ensure that all
412 >     * accessible bins in both the old and new table are usable by any
413 >     * traversal.  This is arranged in part by proceeding from the
414 >     * last bin (table.length - 1) up towards the first.  Upon seeing
415 >     * a forwarding node, traversals (see class Traverser) arrange to
416 >     * move to the new table without revisiting nodes.  To ensure that
417 >     * no intervening nodes are skipped even when moved out of order,
418 >     * a stack (see class TableStack) is created on first encounter of
419 >     * a forwarding node during a traversal, to maintain its place if
420 >     * later processing the current table. The need for these
421 >     * save/restore mechanics is relatively rare, but when one
422 >     * forwarding node is encountered, typically many more will be.
423 >     * So Traversers use a simple caching scheme to avoid creating so
424 >     * many new TableStack nodes. (Thanks to Peter Levart for
425 >     * suggesting use of a stack here.)
426       *
427       * The traversal scheme also applies to partial traversals of
428       * ranges of bins (via an alternate Traverser constructor)
# Line 461 | Line 437 | public class ConcurrentHashMapV8<K, V>
437       * These cases attempt to override the initial capacity settings,
438       * but harmlessly fail to take effect in cases of races.
439       *
440 <     * The element count is maintained using a LongAdder, which avoids
441 <     * contention on updates but can encounter cache thrashing if read
442 <     * too frequently during concurrent access. To avoid reading so
443 <     * often, resizing is attempted either when a bin lock is
444 <     * contended, or upon adding to a bin already holding two or more
445 <     * nodes (checked before adding in the xIfAbsent methods, after
446 <     * adding in others). Under uniform hash distributions, the
447 <     * probability of this occurring at threshold is around 13%,
448 <     * meaning that only about 1 in 8 puts check threshold (and after
449 <     * resizing, many fewer do so). But this approximation has high
450 <     * variance for small table sizes, so we check on any collision
451 <     * for sizes <= 64. The bulk putAll operation further reduces
452 <     * contention by only committing count updates upon these size
453 <     * checks.
440 >     * The element count is maintained using a specialization of
441 >     * LongAdder. We need to incorporate a specialization rather than
442 >     * just use a LongAdder in order to access implicit
443 >     * contention-sensing that leads to creation of multiple
444 >     * CounterCells.  The counter mechanics avoid contention on
445 >     * updates but can encounter cache thrashing if read too
446 >     * frequently during concurrent access. To avoid reading so often,
447 >     * resizing under contention is attempted only upon adding to a
448 >     * bin already holding two or more nodes. Under uniform hash
449 >     * distributions, the probability of this occurring at threshold
450 >     * is around 13%, meaning that only about 1 in 8 puts check
451 >     * threshold (and after resizing, many fewer do so).
452 >     *
453 >     * TreeBins use a special form of comparison for search and
454 >     * related operations (which is the main reason we cannot use
455 >     * existing collections such as TreeMaps). TreeBins contain
456 >     * Comparable elements, but may contain others, as well as
457 >     * elements that are Comparable but not necessarily Comparable for
458 >     * the same T, so we cannot invoke compareTo among them. To handle
459 >     * this, the tree is ordered primarily by hash value, then by
460 >     * Comparable.compareTo order if applicable.  On lookup at a node,
461 >     * if elements are not comparable or compare as 0 then both left
462 >     * and right children may need to be searched in the case of tied
463 >     * hash values. (This corresponds to the full list search that
464 >     * would be necessary if all elements were non-Comparable and had
465 >     * tied hashes.) On insertion, to keep a total ordering (or as
466 >     * close as is required here) across rebalancings, we compare
467 >     * classes and identityHashCodes as tie-breakers. The red-black
468 >     * balancing code is updated from pre-jdk-collections
469 >     * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
470 >     * based in turn on Cormen, Leiserson, and Rivest "Introduction to
471 >     * Algorithms" (CLR).
472 >     *
473 >     * TreeBins also require an additional locking mechanism.  While
474 >     * list traversal is always possible by readers even during
475 >     * updates, tree traversal is not, mainly because of tree-rotations
476 >     * that may change the root node and/or its linkages.  TreeBins
477 >     * include a simple read-write lock mechanism parasitic on the
478 >     * main bin-synchronization strategy: Structural adjustments
479 >     * associated with an insertion or removal are already bin-locked
480 >     * (and so cannot conflict with other writers) but must wait for
481 >     * ongoing readers to finish. Since there can be only one such
482 >     * waiter, we use a simple scheme using a single "waiter" field to
483 >     * block writers.  However, readers need never block.  If the root
484 >     * lock is held, they proceed along the slow traversal path (via
485 >     * next-pointers) until the lock becomes available or the list is
486 >     * exhausted, whichever comes first. These cases are not fast, but
487 >     * maximize aggregate expected throughput.
488       *
489       * Maintaining API and serialization compatibility with previous
490       * versions of this class introduces several oddities. Mainly: We
# Line 484 | Line 494 | public class ConcurrentHashMapV8<K, V>
494       * time that we can guarantee to honor it.) We also declare an
495       * unused "Segment" class that is instantiated in minimal form
496       * only when serializing.
497 +     *
498 +     * Also, solely for compatibility with previous versions of this
499 +     * class, it extends AbstractMap, even though all of its methods
500 +     * are overridden, so it is just useless baggage.
501 +     *
502 +     * This file is organized to make things a little easier to follow
503 +     * while reading than they might otherwise: First the main static
504 +     * declarations and utilities, then fields, then main public
505 +     * methods (with a few factorings of multiple public methods into
506 +     * internal ones), then sizing methods, trees, traversers, and
507 +     * bulk operations.
508       */
509  
510      /* ---------------- Constants -------------- */
# Line 525 | Line 546 | public class ConcurrentHashMapV8<K, V>
546      private static final float LOAD_FACTOR = 0.75f;
547  
548      /**
549 <     * The buffer size for skipped bins during transfers. The
550 <     * value is arbitrary but should be large enough to avoid
551 <     * most locking stalls during resizes.
549 >     * The bin count threshold for using a tree rather than list for a
550 >     * bin.  Bins are converted to trees when adding an element to a
551 >     * bin with at least this many nodes. The value must be greater
552 >     * than 2, and should be at least 8 to mesh with assumptions in
553 >     * tree removal about conversion back to plain bins upon
554 >     * shrinkage.
555       */
556 <    private static final int TRANSFER_BUFFER_SIZE = 32;
556 >    static final int TREEIFY_THRESHOLD = 8;
557  
558      /**
559 <     * The bin count threshold for using a tree rather than list for a
560 <     * bin.  The value reflects the approximate break-even point for
561 <     * using tree-based operations.
559 >     * The bin count threshold for untreeifying a (split) bin during a
560 >     * resize operation. Should be less than TREEIFY_THRESHOLD, and at
561 >     * most 6 to mesh with shrinkage detection under removal.
562       */
563 <    private static final int TREE_THRESHOLD = 8;
563 >    static final int UNTREEIFY_THRESHOLD = 6;
564  
565 <    /*
566 <     * Encodings for special uses of Node hash fields. See above for
567 <     * explanation.
565 >    /**
566 >     * The smallest table capacity for which bins may be treeified.
567 >     * (Otherwise the table is resized if too many nodes in a bin.)
568 >     * The value should be at least 4 * TREEIFY_THRESHOLD to avoid
569 >     * conflicts between resizing and treeification thresholds.
570       */
571 <    static final int MOVED     = 0x80000000; // hash field for forwarding nodes
546 <    static final int LOCKED    = 0x40000000; // set/tested only as a bit
547 <    static final int WAITING   = 0xc0000000; // both bits set/tested together
548 <    static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash
549 <
550 <    /* ---------------- Fields -------------- */
571 >    static final int MIN_TREEIFY_CAPACITY = 64;
572  
573      /**
574 <     * The array of bins. Lazily initialized upon first insertion.
575 <     * Size is always a power of two. Accessed directly by iterators.
574 >     * Minimum number of rebinnings per transfer step. Ranges are
575 >     * subdivided to allow multiple resizer threads.  This value
576 >     * serves as a lower bound to avoid resizers encountering
577 >     * excessive memory contention.  The value should be at least
578 >     * DEFAULT_CAPACITY.
579       */
580 <    transient volatile Node[] table;
580 >    private static final int MIN_TRANSFER_STRIDE = 16;
581  
582      /**
583 <     * The counter maintaining number of elements.
583 >     * The number of bits used for generation stamp in sizeCtl.
584 >     * Must be at least 6 for 32bit arrays.
585       */
586 <    private transient final LongAdder counter;
586 >    private static int RESIZE_STAMP_BITS = 16;
587  
588      /**
589 <     * Table initialization and resizing control.  When negative, the
590 <     * table is being initialized or resized. Otherwise, when table is
566 <     * null, holds the initial table size to use upon creation, or 0
567 <     * for default. After initialization, holds the next element count
568 <     * value upon which to resize the table.
589 >     * The maximum number of threads that can help resize.
590 >     * Must fit in 32 - RESIZE_STAMP_BITS bits.
591       */
592 <    private transient volatile int sizeCtl;
571 <
572 <    // views
573 <    private transient KeySetView<K,V> keySet;
574 <    private transient ValuesView<K,V> values;
575 <    private transient EntrySetView<K,V> entrySet;
576 <
577 <    /** For serialization compatibility. Null unless serialized; see below */
578 <    private Segment<K,V>[] segments;
592 >    private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
593  
594 <    /* ---------------- Table element access -------------- */
594 >    /**
595 >     * The bit shift for recording size stamp in sizeCtl.
596 >     */
597 >    private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
598  
599      /*
600 <     * Volatile access methods are used for table elements as well as
584 <     * elements of in-progress next table while resizing.  Uses are
585 <     * null checked by callers, and implicitly bounds-checked, relying
586 <     * on the invariants that tab arrays have non-zero size, and all
587 <     * indices are masked with (tab.length - 1) which is never
588 <     * negative and always less than length. Note that, to be correct
589 <     * wrt arbitrary concurrency errors by users, bounds checks must
590 <     * operate on local variables, which accounts for some odd-looking
591 <     * inline assignments below.
600 >     * Encodings for Node hash fields. See above for explanation.
601       */
602 <
603 <    static final Node tabAt(Node[] tab, int i) { // used by Iter
604 <        return (Node)UNSAFE.getObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE);
605 <    }
606 <
607 <    private static final boolean casTabAt(Node[] tab, int i, Node c, Node v) {
608 <        return UNSAFE.compareAndSwapObject(tab, ((long)i<<ASHIFT)+ABASE, c, v);
609 <    }
610 <
611 <    private static final void setTabAt(Node[] tab, int i, Node v) {
612 <        UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v);
613 <    }
602 >    static final int MOVED     = -1; // hash for forwarding nodes
603 >    static final int TREEBIN   = -2; // hash for roots of trees
604 >    static final int RESERVED  = -3; // hash for transient reservations
605 >    static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
606 >
607 >    /** Number of CPUS, to place bounds on some sizings */
608 >    static final int NCPU = Runtime.getRuntime().availableProcessors();
609 >
610 >    /** For serialization compatibility. */
611 >    private static final ObjectStreamField[] serialPersistentFields = {
612 >        new ObjectStreamField("segments", Segment[].class),
613 >        new ObjectStreamField("segmentMask", Integer.TYPE),
614 >        new ObjectStreamField("segmentShift", Integer.TYPE)
615 >    };
616  
617      /* ---------------- Nodes -------------- */
618  
619      /**
620 <     * Key-value entry. Note that this is never exported out as a
621 <     * user-visible Map.Entry (see MapEntry below). Nodes with a hash
622 <     * field of MOVED are special, and do not contain user keys or
623 <     * values.  Otherwise, keys are never null, and null val fields
624 <     * indicate that a node is in the process of being deleted or
625 <     * created. For purposes of read-only access, a key may be read
626 <     * before a val, but can only be used after checking val to be
627 <     * non-null.
628 <     */
629 <    static class Node {
630 <        volatile int hash;
631 <        final Object key;
621 <        volatile Object val;
622 <        volatile Node next;
620 >     * Key-value entry.  This class is never exported out as a
621 >     * user-mutable Map.Entry (i.e., one supporting setValue; see
622 >     * MapEntry below), but can be used for read-only traversals used
623 >     * in bulk tasks.  Subclasses of Node with a negative hash field
624 >     * are special, and contain null keys and values (but are never
625 >     * exported).  Otherwise, keys and vals are never null.
626 >     */
627 >    static class Node<K,V> implements Map.Entry<K,V> {
628 >        final int hash;
629 >        final K key;
630 >        volatile V val;
631 >        volatile Node<K,V> next;
632  
633 <        Node(int hash, Object key, Object val, Node next) {
633 >        Node(int hash, K key, V val, Node<K,V> next) {
634              this.hash = hash;
635              this.key = key;
636              this.val = val;
637              this.next = next;
638          }
639  
640 <        /** CompareAndSet the hash field */
641 <        final boolean casHash(int cmp, int val) {
642 <            return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val);
643 <        }
644 <
645 <        /** The number of spins before blocking for a lock */
637 <        static final int MAX_SPINS =
638 <            Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
639 <
640 <        /**
641 <         * Spins a while if LOCKED bit set and this node is the first
642 <         * of its bin, and then sets WAITING bits on hash field and
643 <         * blocks (once) if they are still set.  It is OK for this
644 <         * method to return even if lock is not available upon exit,
645 <         * which enables these simple single-wait mechanics.
646 <         *
647 <         * The corresponding signalling operation is performed within
648 <         * callers: Upon detecting that WAITING has been set when
649 <         * unlocking lock (via a failed CAS from non-waiting LOCKED
650 <         * state), unlockers acquire the sync lock and perform a
651 <         * notifyAll.
652 <         *
653 <         * The initial sanity check on tab and bounds is not currently
654 <         * necessary in the only usages of this method, but enables
655 <         * use in other future contexts.
656 <         */
657 <        final void tryAwaitLock(Node[] tab, int i) {
658 <            if (tab != null && i >= 0 && i < tab.length) { // sanity check
659 <                int r = ThreadLocalRandom.current().nextInt(); // randomize spins
660 <                int spins = MAX_SPINS, h;
661 <                while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) {
662 <                    if (spins >= 0) {
663 <                        r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
664 <                        if (r >= 0 && --spins == 0)
665 <                            Thread.yield();  // yield before block
666 <                    }
667 <                    else if (casHash(h, h | WAITING)) {
668 <                        synchronized (this) {
669 <                            if (tabAt(tab, i) == this &&
670 <                                (hash & WAITING) == WAITING) {
671 <                                try {
672 <                                    wait();
673 <                                } catch (InterruptedException ie) {
674 <                                    Thread.currentThread().interrupt();
675 <                                }
676 <                            }
677 <                            else
678 <                                notifyAll(); // possibly won race vs signaller
679 <                        }
680 <                        break;
681 <                    }
682 <                }
683 <            }
684 <        }
685 <
686 <        // Unsafe mechanics for casHash
687 <        private static final sun.misc.Unsafe UNSAFE;
688 <        private static final long hashOffset;
689 <
690 <        static {
691 <            try {
692 <                UNSAFE = getUnsafe();
693 <                Class<?> k = Node.class;
694 <                hashOffset = UNSAFE.objectFieldOffset
695 <                    (k.getDeclaredField("hash"));
696 <            } catch (Exception e) {
697 <                throw new Error(e);
698 <            }
699 <        }
700 <    }
701 <
702 <    /* ---------------- TreeBins -------------- */
703 <
704 <    /**
705 <     * Nodes for use in TreeBins
706 <     */
707 <    static final class TreeNode extends Node {
708 <        TreeNode parent;  // red-black tree links
709 <        TreeNode left;
710 <        TreeNode right;
711 <        TreeNode prev;    // needed to unlink next upon deletion
712 <        boolean red;
713 <
714 <        TreeNode(int hash, Object key, Object val, Node next, TreeNode parent) {
715 <            super(hash, key, val, next);
716 <            this.parent = parent;
717 <        }
718 <    }
719 <
720 <    /**
721 <     * A specialized form of red-black tree for use in bins
722 <     * whose size exceeds a threshold.
723 <     *
724 <     * TreeBins use a special form of comparison for search and
725 <     * related operations (which is the main reason we cannot use
726 <     * existing collections such as TreeMaps). TreeBins contain
727 <     * Comparable elements, but may contain others, as well as
728 <     * elements that are Comparable but not necessarily Comparable<T>
729 <     * for the same T, so we cannot invoke compareTo among them. To
730 <     * handle this, the tree is ordered primarily by hash value, then
731 <     * by getClass().getName() order, and then by Comparator order
732 <     * among elements of the same class.  On lookup at a node, if
733 <     * elements are not comparable or compare as 0, both left and
734 <     * right children may need to be searched in the case of tied hash
735 <     * values. (This corresponds to the full list search that would be
736 <     * necessary if all elements were non-Comparable and had tied
737 <     * hashes.)  The red-black balancing code is updated from
738 <     * pre-jdk-collections
739 <     * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
740 <     * based in turn on Cormen, Leiserson, and Rivest "Introduction to
741 <     * Algorithms" (CLR).
742 <     *
743 <     * TreeBins also maintain a separate locking discipline than
744 <     * regular bins. Because they are forwarded via special MOVED
745 <     * nodes at bin heads (which can never change once established),
746 <     * we cannot use those nodes as locks. Instead, TreeBin
747 <     * extends AbstractQueuedSynchronizer to support a simple form of
748 <     * read-write lock. For update operations and table validation,
749 <     * the exclusive form of lock behaves in the same way as bin-head
750 <     * locks. However, lookups use shared read-lock mechanics to allow
751 <     * multiple readers in the absence of writers.  Additionally,
752 <     * these lookups do not ever block: While the lock is not
753 <     * available, they proceed along the slow traversal path (via
754 <     * next-pointers) until the lock becomes available or the list is
755 <     * exhausted, whichever comes first. (These cases are not fast,
756 <     * but maximize aggregate expected throughput.)  The AQS mechanics
757 <     * for doing this are straightforward.  The lock state is held as
758 <     * AQS getState().  Read counts are negative; the write count (1)
759 <     * is positive.  There are no signalling preferences among readers
760 <     * and writers. Since we don't need to export full Lock API, we
761 <     * just override the minimal AQS methods and use them directly.
762 <     */
763 <    static final class TreeBin extends AbstractQueuedSynchronizer {
764 <        private static final long serialVersionUID = 2249069246763182397L;
765 <        transient TreeNode root;  // root of tree
766 <        transient TreeNode first; // head of next-pointer list
767 <
768 <        /* AQS overrides */
769 <        public final boolean isHeldExclusively() { return getState() > 0; }
770 <        public final boolean tryAcquire(int ignore) {
771 <            if (compareAndSetState(0, 1)) {
772 <                setExclusiveOwnerThread(Thread.currentThread());
773 <                return true;
774 <            }
775 <            return false;
776 <        }
777 <        public final boolean tryRelease(int ignore) {
778 <            setExclusiveOwnerThread(null);
779 <            setState(0);
780 <            return true;
781 <        }
782 <        public final int tryAcquireShared(int ignore) {
783 <            for (int c;;) {
784 <                if ((c = getState()) > 0)
785 <                    return -1;
786 <                if (compareAndSetState(c, c -1))
787 <                    return 1;
788 <            }
789 <        }
790 <        public final boolean tryReleaseShared(int ignore) {
791 <            int c;
792 <            do {} while (!compareAndSetState(c = getState(), c + 1));
793 <            return c == -1;
794 <        }
795 <
796 <        /** From CLR */
797 <        private void rotateLeft(TreeNode p) {
798 <            if (p != null) {
799 <                TreeNode r = p.right, pp, rl;
800 <                if ((rl = p.right = r.left) != null)
801 <                    rl.parent = p;
802 <                if ((pp = r.parent = p.parent) == null)
803 <                    root = r;
804 <                else if (pp.left == p)
805 <                    pp.left = r;
806 <                else
807 <                    pp.right = r;
808 <                r.left = p;
809 <                p.parent = r;
810 <            }
811 <        }
812 <
813 <        /** From CLR */
814 <        private void rotateRight(TreeNode p) {
815 <            if (p != null) {
816 <                TreeNode l = p.left, pp, lr;
817 <                if ((lr = p.left = l.right) != null)
818 <                    lr.parent = p;
819 <                if ((pp = l.parent = p.parent) == null)
820 <                    root = l;
821 <                else if (pp.right == p)
822 <                    pp.right = l;
823 <                else
824 <                    pp.left = l;
825 <                l.right = p;
826 <                p.parent = l;
827 <            }
828 <        }
829 <
830 <        /**
831 <         * Returns the TreeNode (or null if not found) for the given key
832 <         * starting at given root.
833 <         */
834 <        @SuppressWarnings("unchecked") final TreeNode getTreeNode
835 <            (int h, Object k, TreeNode p) {
836 <            Class<?> c = k.getClass();
837 <            while (p != null) {
838 <                int dir, ph;  Object pk; Class<?> pc;
839 <                if ((ph = p.hash) == h) {
840 <                    if ((pk = p.key) == k || k.equals(pk))
841 <                        return p;
842 <                    if (c != (pc = pk.getClass()) ||
843 <                        !(k instanceof Comparable) ||
844 <                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
845 <                        dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName());
846 <                        TreeNode r = null, s = null, pl, pr;
847 <                        if (dir >= 0) {
848 <                            if ((pl = p.left) != null && h <= pl.hash)
849 <                                s = pl;
850 <                        }
851 <                        else if ((pr = p.right) != null && h >= pr.hash)
852 <                            s = pr;
853 <                        if (s != null && (r = getTreeNode(h, k, s)) != null)
854 <                            return r;
855 <                    }
856 <                }
857 <                else
858 <                    dir = (h < ph) ? -1 : 1;
859 <                p = (dir > 0) ? p.right : p.left;
860 <            }
861 <            return null;
640 >        public final K getKey()     { return key; }
641 >        public final V getValue()   { return val; }
642 >        public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
643 >        public final String toString() { return key + "=" + val; }
644 >        public final V setValue(V value) {
645 >            throw new UnsupportedOperationException();
646          }
647  
648 <        /**
649 <         * Wrapper for getTreeNode used by CHM.get. Tries to obtain
650 <         * read-lock to call getTreeNode, but during failure to get
651 <         * lock, searches along next links.
652 <         */
653 <        final Object getValue(int h, Object k) {
654 <            Node r = null;
871 <            int c = getState(); // Must read lock state first
872 <            for (Node e = first; e != null; e = e.next) {
873 <                if (c <= 0 && compareAndSetState(c, c - 1)) {
874 <                    try {
875 <                        r = getTreeNode(h, k, root);
876 <                    } finally {
877 <                        releaseShared(0);
878 <                    }
879 <                    break;
880 <                }
881 <                else if ((e.hash & HASH_BITS) == h && k.equals(e.key)) {
882 <                    r = e;
883 <                    break;
884 <                }
885 <                else
886 <                    c = getState();
887 <            }
888 <            return r == null ? null : r.val;
648 >        public final boolean equals(Object o) {
649 >            Object k, v, u; Map.Entry<?,?> e;
650 >            return ((o instanceof Map.Entry) &&
651 >                    (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
652 >                    (v = e.getValue()) != null &&
653 >                    (k == key || k.equals(key)) &&
654 >                    (v == (u = val) || v.equals(u)));
655          }
656  
657          /**
658 <         * Finds or adds a node.
893 <         * @return null if added
658 >         * Virtualized support for map.get(); overridden in subclasses.
659           */
660 <        @SuppressWarnings("unchecked") final TreeNode putTreeNode
661 <            (int h, Object k, Object v) {
662 <            Class<?> c = k.getClass();
663 <            TreeNode pp = root, p = null;
664 <            int dir = 0;
665 <            while (pp != null) { // find existing node or leaf to insert at
666 <                int ph;  Object pk; Class<?> pc;
667 <                p = pp;
668 <                if ((ph = p.hash) == h) {
904 <                    if ((pk = p.key) == k || k.equals(pk))
905 <                        return p;
906 <                    if (c != (pc = pk.getClass()) ||
907 <                        !(k instanceof Comparable) ||
908 <                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
909 <                        dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName());
910 <                        TreeNode r = null, s = null, pl, pr;
911 <                        if (dir >= 0) {
912 <                            if ((pl = p.left) != null && h <= pl.hash)
913 <                                s = pl;
914 <                        }
915 <                        else if ((pr = p.right) != null && h >= pr.hash)
916 <                            s = pr;
917 <                        if (s != null && (r = getTreeNode(h, k, s)) != null)
918 <                            return r;
919 <                    }
920 <                }
921 <                else
922 <                    dir = (h < ph) ? -1 : 1;
923 <                pp = (dir > 0) ? p.right : p.left;
924 <            }
925 <
926 <            TreeNode f = first;
927 <            TreeNode x = first = new TreeNode(h, k, v, f, p);
928 <            if (p == null)
929 <                root = x;
930 <            else { // attach and rebalance; adapted from CLR
931 <                TreeNode xp, xpp;
932 <                if (f != null)
933 <                    f.prev = x;
934 <                if (dir <= 0)
935 <                    p.left = x;
936 <                else
937 <                    p.right = x;
938 <                x.red = true;
939 <                while (x != null && (xp = x.parent) != null && xp.red &&
940 <                       (xpp = xp.parent) != null) {
941 <                    TreeNode xppl = xpp.left;
942 <                    if (xp == xppl) {
943 <                        TreeNode y = xpp.right;
944 <                        if (y != null && y.red) {
945 <                            y.red = false;
946 <                            xp.red = false;
947 <                            xpp.red = true;
948 <                            x = xpp;
949 <                        }
950 <                        else {
951 <                            if (x == xp.right) {
952 <                                rotateLeft(x = xp);
953 <                                xpp = (xp = x.parent) == null ? null : xp.parent;
954 <                            }
955 <                            if (xp != null) {
956 <                                xp.red = false;
957 <                                if (xpp != null) {
958 <                                    xpp.red = true;
959 <                                    rotateRight(xpp);
960 <                                }
961 <                            }
962 <                        }
963 <                    }
964 <                    else {
965 <                        TreeNode y = xppl;
966 <                        if (y != null && y.red) {
967 <                            y.red = false;
968 <                            xp.red = false;
969 <                            xpp.red = true;
970 <                            x = xpp;
971 <                        }
972 <                        else {
973 <                            if (x == xp.left) {
974 <                                rotateRight(x = xp);
975 <                                xpp = (xp = x.parent) == null ? null : xp.parent;
976 <                            }
977 <                            if (xp != null) {
978 <                                xp.red = false;
979 <                                if (xpp != null) {
980 <                                    xpp.red = true;
981 <                                    rotateLeft(xpp);
982 <                                }
983 <                            }
984 <                        }
985 <                    }
986 <                }
987 <                TreeNode r = root;
988 <                if (r != null && r.red)
989 <                    r.red = false;
660 >        Node<K,V> find(int h, Object k) {
661 >            Node<K,V> e = this;
662 >            if (k != null) {
663 >                do {
664 >                    K ek;
665 >                    if (e.hash == h &&
666 >                        ((ek = e.key) == k || (ek != null && k.equals(ek))))
667 >                        return e;
668 >                } while ((e = e.next) != null);
669              }
670              return null;
671          }
993
994        /**
995         * Removes the given node, that must be present before this
996         * call.  This is messier than typical red-black deletion code
997         * because we cannot swap the contents of an interior node
998         * with a leaf successor that is pinned by "next" pointers
999         * that are accessible independently of lock. So instead we
1000         * swap the tree linkages.
1001         */
1002        final void deleteTreeNode(TreeNode p) {
1003            TreeNode next = (TreeNode)p.next; // unlink traversal pointers
1004            TreeNode pred = p.prev;
1005            if (pred == null)
1006                first = next;
1007            else
1008                pred.next = next;
1009            if (next != null)
1010                next.prev = pred;
1011            TreeNode replacement;
1012            TreeNode pl = p.left;
1013            TreeNode pr = p.right;
1014            if (pl != null && pr != null) {
1015                TreeNode s = pr, sl;
1016                while ((sl = s.left) != null) // find successor
1017                    s = sl;
1018                boolean c = s.red; s.red = p.red; p.red = c; // swap colors
1019                TreeNode sr = s.right;
1020                TreeNode pp = p.parent;
1021                if (s == pr) { // p was s's direct parent
1022                    p.parent = s;
1023                    s.right = p;
1024                }
1025                else {
1026                    TreeNode sp = s.parent;
1027                    if ((p.parent = sp) != null) {
1028                        if (s == sp.left)
1029                            sp.left = p;
1030                        else
1031                            sp.right = p;
1032                    }
1033                    if ((s.right = pr) != null)
1034                        pr.parent = s;
1035                }
1036                p.left = null;
1037                if ((p.right = sr) != null)
1038                    sr.parent = p;
1039                if ((s.left = pl) != null)
1040                    pl.parent = s;
1041                if ((s.parent = pp) == null)
1042                    root = s;
1043                else if (p == pp.left)
1044                    pp.left = s;
1045                else
1046                    pp.right = s;
1047                replacement = sr;
1048            }
1049            else
1050                replacement = (pl != null) ? pl : pr;
1051            TreeNode pp = p.parent;
1052            if (replacement == null) {
1053                if (pp == null) {
1054                    root = null;
1055                    return;
1056                }
1057                replacement = p;
1058            }
1059            else {
1060                replacement.parent = pp;
1061                if (pp == null)
1062                    root = replacement;
1063                else if (p == pp.left)
1064                    pp.left = replacement;
1065                else
1066                    pp.right = replacement;
1067                p.left = p.right = p.parent = null;
1068            }
1069            if (!p.red) { // rebalance, from CLR
1070                TreeNode x = replacement;
1071                while (x != null) {
1072                    TreeNode xp, xpl;
1073                    if (x.red || (xp = x.parent) == null) {
1074                        x.red = false;
1075                        break;
1076                    }
1077                    if (x == (xpl = xp.left)) {
1078                        TreeNode sib = xp.right;
1079                        if (sib != null && sib.red) {
1080                            sib.red = false;
1081                            xp.red = true;
1082                            rotateLeft(xp);
1083                            sib = (xp = x.parent) == null ? null : xp.right;
1084                        }
1085                        if (sib == null)
1086                            x = xp;
1087                        else {
1088                            TreeNode sl = sib.left, sr = sib.right;
1089                            if ((sr == null || !sr.red) &&
1090                                (sl == null || !sl.red)) {
1091                                sib.red = true;
1092                                x = xp;
1093                            }
1094                            else {
1095                                if (sr == null || !sr.red) {
1096                                    if (sl != null)
1097                                        sl.red = false;
1098                                    sib.red = true;
1099                                    rotateRight(sib);
1100                                    sib = (xp = x.parent) == null ? null : xp.right;
1101                                }
1102                                if (sib != null) {
1103                                    sib.red = (xp == null) ? false : xp.red;
1104                                    if ((sr = sib.right) != null)
1105                                        sr.red = false;
1106                                }
1107                                if (xp != null) {
1108                                    xp.red = false;
1109                                    rotateLeft(xp);
1110                                }
1111                                x = root;
1112                            }
1113                        }
1114                    }
1115                    else { // symmetric
1116                        TreeNode sib = xpl;
1117                        if (sib != null && sib.red) {
1118                            sib.red = false;
1119                            xp.red = true;
1120                            rotateRight(xp);
1121                            sib = (xp = x.parent) == null ? null : xp.left;
1122                        }
1123                        if (sib == null)
1124                            x = xp;
1125                        else {
1126                            TreeNode sl = sib.left, sr = sib.right;
1127                            if ((sl == null || !sl.red) &&
1128                                (sr == null || !sr.red)) {
1129                                sib.red = true;
1130                                x = xp;
1131                            }
1132                            else {
1133                                if (sl == null || !sl.red) {
1134                                    if (sr != null)
1135                                        sr.red = false;
1136                                    sib.red = true;
1137                                    rotateLeft(sib);
1138                                    sib = (xp = x.parent) == null ? null : xp.left;
1139                                }
1140                                if (sib != null) {
1141                                    sib.red = (xp == null) ? false : xp.red;
1142                                    if ((sl = sib.left) != null)
1143                                        sl.red = false;
1144                                }
1145                                if (xp != null) {
1146                                    xp.red = false;
1147                                    rotateRight(xp);
1148                                }
1149                                x = root;
1150                            }
1151                        }
1152                    }
1153                }
1154            }
1155            if (p == replacement && (pp = p.parent) != null) {
1156                if (p == pp.left) // detach pointers
1157                    pp.left = null;
1158                else if (p == pp.right)
1159                    pp.right = null;
1160                p.parent = null;
1161            }
1162        }
672      }
673  
674 <    /* ---------------- Collision reduction methods -------------- */
674 >    /* ---------------- Static utilities -------------- */
675  
676      /**
677 <     * Spreads higher bits to lower, and also forces top 2 bits to 0.
678 <     * Because the table uses power-of-two masking, sets of hashes
679 <     * that vary only in bits above the current mask will always
680 <     * collide. (Among known examples are sets of Float keys holding
681 <     * consecutive whole numbers in small tables.)  To counter this,
682 <     * we apply a transform that spreads the impact of higher bits
677 >     * Spreads (XORs) higher bits of hash to lower and also forces top
678 >     * bit to 0. Because the table uses power-of-two masking, sets of
679 >     * hashes that vary only in bits above the current mask will
680 >     * always collide. (Among known examples are sets of Float keys
681 >     * holding consecutive whole numbers in small tables.)  So we
682 >     * apply a transform that spreads the impact of higher bits
683       * downward. There is a tradeoff between speed, utility, and
684       * quality of bit-spreading. Because many common sets of hashes
685 <     * are already reasonably distributed across bits (so don't benefit
686 <     * from spreading), and because we use trees to handle large sets
687 <     * of collisions in bins, we don't need excessively high quality.
688 <     */
689 <    private static final int spread(int h) {
690 <        h ^= (h >>> 18) ^ (h >>> 12);
1182 <        return (h ^ (h >>> 10)) & HASH_BITS;
1183 <    }
1184 <
1185 <    /**
1186 <     * Replaces a list bin with a tree bin. Call only when locked.
1187 <     * Fails to replace if the given key is non-comparable or table
1188 <     * is, or needs, resizing.
685 >     * are already reasonably distributed (so don't benefit from
686 >     * spreading), and because we use trees to handle large sets of
687 >     * collisions in bins, we just XOR some shifted bits in the
688 >     * cheapest possible way to reduce systematic lossage, as well as
689 >     * to incorporate impact of the highest bits that would otherwise
690 >     * never be used in index calculations because of table bounds.
691       */
692 <    private final void replaceWithTreeBin(Node[] tab, int index, Object key) {
693 <        if ((key instanceof Comparable) &&
1192 <            (tab.length >= MAXIMUM_CAPACITY || counter.sum() < (long)sizeCtl)) {
1193 <            TreeBin t = new TreeBin();
1194 <            for (Node e = tabAt(tab, index); e != null; e = e.next)
1195 <                t.putTreeNode(e.hash & HASH_BITS, e.key, e.val);
1196 <            setTabAt(tab, index, new Node(MOVED, t, null, null));
1197 <        }
1198 <    }
1199 <
1200 <    /* ---------------- Internal access and update methods -------------- */
1201 <
1202 <    /** Implementation for get and containsKey */
1203 <    private final Object internalGet(Object k) {
1204 <        int h = spread(k.hashCode());
1205 <        retry: for (Node[] tab = table; tab != null;) {
1206 <            Node e, p; Object ek, ev; int eh;      // locals to read fields once
1207 <            for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
1208 <                if ((eh = e.hash) == MOVED) {
1209 <                    if ((ek = e.key) instanceof TreeBin)  // search TreeBin
1210 <                        return ((TreeBin)ek).getValue(h, k);
1211 <                    else {                        // restart with new table
1212 <                        tab = (Node[])ek;
1213 <                        continue retry;
1214 <                    }
1215 <                }
1216 <                else if ((eh & HASH_BITS) == h && (ev = e.val) != null &&
1217 <                         ((ek = e.key) == k || k.equals(ek)))
1218 <                    return ev;
1219 <            }
1220 <            break;
1221 <        }
1222 <        return null;
1223 <    }
1224 <
1225 <    /**
1226 <     * Implementation for the four public remove/replace methods:
1227 <     * Replaces node value with v, conditional upon match of cv if
1228 <     * non-null.  If resulting value is null, delete.
1229 <     */
1230 <    private final Object internalReplace(Object k, Object v, Object cv) {
1231 <        int h = spread(k.hashCode());
1232 <        Object oldVal = null;
1233 <        for (Node[] tab = table;;) {
1234 <            Node f; int i, fh; Object fk;
1235 <            if (tab == null ||
1236 <                (f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1237 <                break;
1238 <            else if ((fh = f.hash) == MOVED) {
1239 <                if ((fk = f.key) instanceof TreeBin) {
1240 <                    TreeBin t = (TreeBin)fk;
1241 <                    boolean validated = false;
1242 <                    boolean deleted = false;
1243 <                    t.acquire(0);
1244 <                    try {
1245 <                        if (tabAt(tab, i) == f) {
1246 <                            validated = true;
1247 <                            TreeNode p = t.getTreeNode(h, k, t.root);
1248 <                            if (p != null) {
1249 <                                Object pv = p.val;
1250 <                                if (cv == null || cv == pv || cv.equals(pv)) {
1251 <                                    oldVal = pv;
1252 <                                    if ((p.val = v) == null) {
1253 <                                        deleted = true;
1254 <                                        t.deleteTreeNode(p);
1255 <                                    }
1256 <                                }
1257 <                            }
1258 <                        }
1259 <                    } finally {
1260 <                        t.release(0);
1261 <                    }
1262 <                    if (validated) {
1263 <                        if (deleted)
1264 <                            counter.add(-1L);
1265 <                        break;
1266 <                    }
1267 <                }
1268 <                else
1269 <                    tab = (Node[])fk;
1270 <            }
1271 <            else if ((fh & HASH_BITS) != h && f.next == null) // precheck
1272 <                break;                          // rules out possible existence
1273 <            else if ((fh & LOCKED) != 0) {
1274 <                checkForResize();               // try resizing if can't get lock
1275 <                f.tryAwaitLock(tab, i);
1276 <            }
1277 <            else if (f.casHash(fh, fh | LOCKED)) {
1278 <                boolean validated = false;
1279 <                boolean deleted = false;
1280 <                try {
1281 <                    if (tabAt(tab, i) == f) {
1282 <                        validated = true;
1283 <                        for (Node e = f, pred = null;;) {
1284 <                            Object ek, ev;
1285 <                            if ((e.hash & HASH_BITS) == h &&
1286 <                                ((ev = e.val) != null) &&
1287 <                                ((ek = e.key) == k || k.equals(ek))) {
1288 <                                if (cv == null || cv == ev || cv.equals(ev)) {
1289 <                                    oldVal = ev;
1290 <                                    if ((e.val = v) == null) {
1291 <                                        deleted = true;
1292 <                                        Node en = e.next;
1293 <                                        if (pred != null)
1294 <                                            pred.next = en;
1295 <                                        else
1296 <                                            setTabAt(tab, i, en);
1297 <                                    }
1298 <                                }
1299 <                                break;
1300 <                            }
1301 <                            pred = e;
1302 <                            if ((e = e.next) == null)
1303 <                                break;
1304 <                        }
1305 <                    }
1306 <                } finally {
1307 <                    if (!f.casHash(fh | LOCKED, fh)) {
1308 <                        f.hash = fh;
1309 <                        synchronized (f) { f.notifyAll(); };
1310 <                    }
1311 <                }
1312 <                if (validated) {
1313 <                    if (deleted)
1314 <                        counter.add(-1L);
1315 <                    break;
1316 <                }
1317 <            }
1318 <        }
1319 <        return oldVal;
1320 <    }
1321 <
1322 <    /*
1323 <     * Internal versions of the six insertion methods, each a
1324 <     * little more complicated than the last. All have
1325 <     * the same basic structure as the first (internalPut):
1326 <     *  1. If table uninitialized, create
1327 <     *  2. If bin empty, try to CAS new node
1328 <     *  3. If bin stale, use new table
1329 <     *  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1330 <     *  5. Lock and validate; if valid, scan and add or update
1331 <     *
1332 <     * The others interweave other checks and/or alternative actions:
1333 <     *  * Plain put checks for and performs resize after insertion.
1334 <     *  * putIfAbsent prescans for mapping without lock (and fails to add
1335 <     *    if present), which also makes pre-emptive resize checks worthwhile.
1336 <     *  * computeIfAbsent extends form used in putIfAbsent with additional
1337 <     *    mechanics to deal with, calls, potential exceptions and null
1338 <     *    returns from function call.
1339 <     *  * compute uses the same function-call mechanics, but without
1340 <     *    the prescans
1341 <     *  * merge acts as putIfAbsent in the absent case, but invokes the
1342 <     *    update function if present
1343 <     *  * putAll attempts to pre-allocate enough table space
1344 <     *    and more lazily performs count updates and checks.
1345 <     *
1346 <     * Someday when details settle down a bit more, it might be worth
1347 <     * some factoring to reduce sprawl.
1348 <     */
1349 <
1350 <    /** Implementation for put */
1351 <    private final Object internalPut(Object k, Object v) {
1352 <        int h = spread(k.hashCode());
1353 <        int count = 0;
1354 <        for (Node[] tab = table;;) {
1355 <            int i; Node f; int fh; Object fk;
1356 <            if (tab == null)
1357 <                tab = initTable();
1358 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1359 <                if (casTabAt(tab, i, null, new Node(h, k, v, null)))
1360 <                    break;                   // no lock when adding to empty bin
1361 <            }
1362 <            else if ((fh = f.hash) == MOVED) {
1363 <                if ((fk = f.key) instanceof TreeBin) {
1364 <                    TreeBin t = (TreeBin)fk;
1365 <                    Object oldVal = null;
1366 <                    t.acquire(0);
1367 <                    try {
1368 <                        if (tabAt(tab, i) == f) {
1369 <                            count = 2;
1370 <                            TreeNode p = t.putTreeNode(h, k, v);
1371 <                            if (p != null) {
1372 <                                oldVal = p.val;
1373 <                                p.val = v;
1374 <                            }
1375 <                        }
1376 <                    } finally {
1377 <                        t.release(0);
1378 <                    }
1379 <                    if (count != 0) {
1380 <                        if (oldVal != null)
1381 <                            return oldVal;
1382 <                        break;
1383 <                    }
1384 <                }
1385 <                else
1386 <                    tab = (Node[])fk;
1387 <            }
1388 <            else if ((fh & LOCKED) != 0) {
1389 <                checkForResize();
1390 <                f.tryAwaitLock(tab, i);
1391 <            }
1392 <            else if (f.casHash(fh, fh | LOCKED)) {
1393 <                Object oldVal = null;
1394 <                try {                        // needed in case equals() throws
1395 <                    if (tabAt(tab, i) == f) {
1396 <                        count = 1;
1397 <                        for (Node e = f;; ++count) {
1398 <                            Object ek, ev;
1399 <                            if ((e.hash & HASH_BITS) == h &&
1400 <                                (ev = e.val) != null &&
1401 <                                ((ek = e.key) == k || k.equals(ek))) {
1402 <                                oldVal = ev;
1403 <                                e.val = v;
1404 <                                break;
1405 <                            }
1406 <                            Node last = e;
1407 <                            if ((e = e.next) == null) {
1408 <                                last.next = new Node(h, k, v, null);
1409 <                                if (count >= TREE_THRESHOLD)
1410 <                                    replaceWithTreeBin(tab, i, k);
1411 <                                break;
1412 <                            }
1413 <                        }
1414 <                    }
1415 <                } finally {                  // unlock and signal if needed
1416 <                    if (!f.casHash(fh | LOCKED, fh)) {
1417 <                        f.hash = fh;
1418 <                        synchronized (f) { f.notifyAll(); };
1419 <                    }
1420 <                }
1421 <                if (count != 0) {
1422 <                    if (oldVal != null)
1423 <                        return oldVal;
1424 <                    if (tab.length <= 64)
1425 <                        count = 2;
1426 <                    break;
1427 <                }
1428 <            }
1429 <        }
1430 <        counter.add(1L);
1431 <        if (count > 1)
1432 <            checkForResize();
1433 <        return null;
1434 <    }
1435 <
1436 <    /** Implementation for putIfAbsent */
1437 <    private final Object internalPutIfAbsent(Object k, Object v) {
1438 <        int h = spread(k.hashCode());
1439 <        int count = 0;
1440 <        for (Node[] tab = table;;) {
1441 <            int i; Node f; int fh; Object fk, fv;
1442 <            if (tab == null)
1443 <                tab = initTable();
1444 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1445 <                if (casTabAt(tab, i, null, new Node(h, k, v, null)))
1446 <                    break;
1447 <            }
1448 <            else if ((fh = f.hash) == MOVED) {
1449 <                if ((fk = f.key) instanceof TreeBin) {
1450 <                    TreeBin t = (TreeBin)fk;
1451 <                    Object oldVal = null;
1452 <                    t.acquire(0);
1453 <                    try {
1454 <                        if (tabAt(tab, i) == f) {
1455 <                            count = 2;
1456 <                            TreeNode p = t.putTreeNode(h, k, v);
1457 <                            if (p != null)
1458 <                                oldVal = p.val;
1459 <                        }
1460 <                    } finally {
1461 <                        t.release(0);
1462 <                    }
1463 <                    if (count != 0) {
1464 <                        if (oldVal != null)
1465 <                            return oldVal;
1466 <                        break;
1467 <                    }
1468 <                }
1469 <                else
1470 <                    tab = (Node[])fk;
1471 <            }
1472 <            else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
1473 <                     ((fk = f.key) == k || k.equals(fk)))
1474 <                return fv;
1475 <            else {
1476 <                Node g = f.next;
1477 <                if (g != null) { // at least 2 nodes -- search and maybe resize
1478 <                    for (Node e = g;;) {
1479 <                        Object ek, ev;
1480 <                        if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
1481 <                            ((ek = e.key) == k || k.equals(ek)))
1482 <                            return ev;
1483 <                        if ((e = e.next) == null) {
1484 <                            checkForResize();
1485 <                            break;
1486 <                        }
1487 <                    }
1488 <                }
1489 <                if (((fh = f.hash) & LOCKED) != 0) {
1490 <                    checkForResize();
1491 <                    f.tryAwaitLock(tab, i);
1492 <                }
1493 <                else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
1494 <                    Object oldVal = null;
1495 <                    try {
1496 <                        if (tabAt(tab, i) == f) {
1497 <                            count = 1;
1498 <                            for (Node e = f;; ++count) {
1499 <                                Object ek, ev;
1500 <                                if ((e.hash & HASH_BITS) == h &&
1501 <                                    (ev = e.val) != null &&
1502 <                                    ((ek = e.key) == k || k.equals(ek))) {
1503 <                                    oldVal = ev;
1504 <                                    break;
1505 <                                }
1506 <                                Node last = e;
1507 <                                if ((e = e.next) == null) {
1508 <                                    last.next = new Node(h, k, v, null);
1509 <                                    if (count >= TREE_THRESHOLD)
1510 <                                        replaceWithTreeBin(tab, i, k);
1511 <                                    break;
1512 <                                }
1513 <                            }
1514 <                        }
1515 <                    } finally {
1516 <                        if (!f.casHash(fh | LOCKED, fh)) {
1517 <                            f.hash = fh;
1518 <                            synchronized (f) { f.notifyAll(); };
1519 <                        }
1520 <                    }
1521 <                    if (count != 0) {
1522 <                        if (oldVal != null)
1523 <                            return oldVal;
1524 <                        if (tab.length <= 64)
1525 <                            count = 2;
1526 <                        break;
1527 <                    }
1528 <                }
1529 <            }
1530 <        }
1531 <        counter.add(1L);
1532 <        if (count > 1)
1533 <            checkForResize();
1534 <        return null;
1535 <    }
1536 <
1537 <    /** Implementation for computeIfAbsent */
1538 <    private final Object internalComputeIfAbsent(K k,
1539 <                                                 Fun<? super K, ?> mf) {
1540 <        int h = spread(k.hashCode());
1541 <        Object val = null;
1542 <        int count = 0;
1543 <        for (Node[] tab = table;;) {
1544 <            Node f; int i, fh; Object fk, fv;
1545 <            if (tab == null)
1546 <                tab = initTable();
1547 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1548 <                Node node = new Node(fh = h | LOCKED, k, null, null);
1549 <                if (casTabAt(tab, i, null, node)) {
1550 <                    count = 1;
1551 <                    try {
1552 <                        if ((val = mf.apply(k)) != null)
1553 <                            node.val = val;
1554 <                    } finally {
1555 <                        if (val == null)
1556 <                            setTabAt(tab, i, null);
1557 <                        if (!node.casHash(fh, h)) {
1558 <                            node.hash = h;
1559 <                            synchronized (node) { node.notifyAll(); };
1560 <                        }
1561 <                    }
1562 <                }
1563 <                if (count != 0)
1564 <                    break;
1565 <            }
1566 <            else if ((fh = f.hash) == MOVED) {
1567 <                if ((fk = f.key) instanceof TreeBin) {
1568 <                    TreeBin t = (TreeBin)fk;
1569 <                    boolean added = false;
1570 <                    t.acquire(0);
1571 <                    try {
1572 <                        if (tabAt(tab, i) == f) {
1573 <                            count = 1;
1574 <                            TreeNode p = t.getTreeNode(h, k, t.root);
1575 <                            if (p != null)
1576 <                                val = p.val;
1577 <                            else if ((val = mf.apply(k)) != null) {
1578 <                                added = true;
1579 <                                count = 2;
1580 <                                t.putTreeNode(h, k, val);
1581 <                            }
1582 <                        }
1583 <                    } finally {
1584 <                        t.release(0);
1585 <                    }
1586 <                    if (count != 0) {
1587 <                        if (!added)
1588 <                            return val;
1589 <                        break;
1590 <                    }
1591 <                }
1592 <                else
1593 <                    tab = (Node[])fk;
1594 <            }
1595 <            else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
1596 <                     ((fk = f.key) == k || k.equals(fk)))
1597 <                return fv;
1598 <            else {
1599 <                Node g = f.next;
1600 <                if (g != null) {
1601 <                    for (Node e = g;;) {
1602 <                        Object ek, ev;
1603 <                        if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
1604 <                            ((ek = e.key) == k || k.equals(ek)))
1605 <                            return ev;
1606 <                        if ((e = e.next) == null) {
1607 <                            checkForResize();
1608 <                            break;
1609 <                        }
1610 <                    }
1611 <                }
1612 <                if (((fh = f.hash) & LOCKED) != 0) {
1613 <                    checkForResize();
1614 <                    f.tryAwaitLock(tab, i);
1615 <                }
1616 <                else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
1617 <                    boolean added = false;
1618 <                    try {
1619 <                        if (tabAt(tab, i) == f) {
1620 <                            count = 1;
1621 <                            for (Node e = f;; ++count) {
1622 <                                Object ek, ev;
1623 <                                if ((e.hash & HASH_BITS) == h &&
1624 <                                    (ev = e.val) != null &&
1625 <                                    ((ek = e.key) == k || k.equals(ek))) {
1626 <                                    val = ev;
1627 <                                    break;
1628 <                                }
1629 <                                Node last = e;
1630 <                                if ((e = e.next) == null) {
1631 <                                    if ((val = mf.apply(k)) != null) {
1632 <                                        added = true;
1633 <                                        last.next = new Node(h, k, val, null);
1634 <                                        if (count >= TREE_THRESHOLD)
1635 <                                            replaceWithTreeBin(tab, i, k);
1636 <                                    }
1637 <                                    break;
1638 <                                }
1639 <                            }
1640 <                        }
1641 <                    } finally {
1642 <                        if (!f.casHash(fh | LOCKED, fh)) {
1643 <                            f.hash = fh;
1644 <                            synchronized (f) { f.notifyAll(); };
1645 <                        }
1646 <                    }
1647 <                    if (count != 0) {
1648 <                        if (!added)
1649 <                            return val;
1650 <                        if (tab.length <= 64)
1651 <                            count = 2;
1652 <                        break;
1653 <                    }
1654 <                }
1655 <            }
1656 <        }
1657 <        if (val != null) {
1658 <            counter.add(1L);
1659 <            if (count > 1)
1660 <                checkForResize();
1661 <        }
1662 <        return val;
692 >    static final int spread(int h) {
693 >        return (h ^ (h >>> 16)) & HASH_BITS;
694      }
695  
1665    /** Implementation for compute */
1666    @SuppressWarnings("unchecked") private final Object internalCompute
1667        (K k, boolean onlyIfPresent, BiFun<? super K, ? super V, ? extends V> mf) {
1668        int h = spread(k.hashCode());
1669        Object val = null;
1670        int delta = 0;
1671        int count = 0;
1672        for (Node[] tab = table;;) {
1673            Node f; int i, fh; Object fk;
1674            if (tab == null)
1675                tab = initTable();
1676            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1677                if (onlyIfPresent)
1678                    break;
1679                Node node = new Node(fh = h | LOCKED, k, null, null);
1680                if (casTabAt(tab, i, null, node)) {
1681                    try {
1682                        count = 1;
1683                        if ((val = mf.apply(k, null)) != null) {
1684                            node.val = val;
1685                            delta = 1;
1686                        }
1687                    } finally {
1688                        if (delta == 0)
1689                            setTabAt(tab, i, null);
1690                        if (!node.casHash(fh, h)) {
1691                            node.hash = h;
1692                            synchronized (node) { node.notifyAll(); };
1693                        }
1694                    }
1695                }
1696                if (count != 0)
1697                    break;
1698            }
1699            else if ((fh = f.hash) == MOVED) {
1700                if ((fk = f.key) instanceof TreeBin) {
1701                    TreeBin t = (TreeBin)fk;
1702                    t.acquire(0);
1703                    try {
1704                        if (tabAt(tab, i) == f) {
1705                            count = 1;
1706                            TreeNode p = t.getTreeNode(h, k, t.root);
1707                            Object pv = (p == null) ? null : p.val;
1708                            if ((val = mf.apply(k, (V)pv)) != null) {
1709                                if (p != null)
1710                                    p.val = val;
1711                                else {
1712                                    count = 2;
1713                                    delta = 1;
1714                                    t.putTreeNode(h, k, val);
1715                                }
1716                            }
1717                            else if (p != null) {
1718                                delta = -1;
1719                                t.deleteTreeNode(p);
1720                            }
1721                        }
1722                    } finally {
1723                        t.release(0);
1724                    }
1725                    if (count != 0)
1726                        break;
1727                }
1728                else
1729                    tab = (Node[])fk;
1730            }
1731            else if ((fh & LOCKED) != 0) {
1732                checkForResize();
1733                f.tryAwaitLock(tab, i);
1734            }
1735            else if (f.casHash(fh, fh | LOCKED)) {
1736                try {
1737                    if (tabAt(tab, i) == f) {
1738                        count = 1;
1739                        for (Node e = f, pred = null;; ++count) {
1740                            Object ek, ev;
1741                            if ((e.hash & HASH_BITS) == h &&
1742                                (ev = e.val) != null &&
1743                                ((ek = e.key) == k || k.equals(ek))) {
1744                                val = mf.apply(k, (V)ev);
1745                                if (val != null)
1746                                    e.val = val;
1747                                else {
1748                                    delta = -1;
1749                                    Node en = e.next;
1750                                    if (pred != null)
1751                                        pred.next = en;
1752                                    else
1753                                        setTabAt(tab, i, en);
1754                                }
1755                                break;
1756                            }
1757                            pred = e;
1758                            if ((e = e.next) == null) {
1759                                if (!onlyIfPresent && (val = mf.apply(k, null)) != null) {
1760                                    pred.next = new Node(h, k, val, null);
1761                                    delta = 1;
1762                                    if (count >= TREE_THRESHOLD)
1763                                        replaceWithTreeBin(tab, i, k);
1764                                }
1765                                break;
1766                            }
1767                        }
1768                    }
1769                } finally {
1770                    if (!f.casHash(fh | LOCKED, fh)) {
1771                        f.hash = fh;
1772                        synchronized (f) { f.notifyAll(); };
1773                    }
1774                }
1775                if (count != 0) {
1776                    if (tab.length <= 64)
1777                        count = 2;
1778                    break;
1779                }
1780            }
1781        }
1782        if (delta != 0) {
1783            counter.add((long)delta);
1784            if (count > 1)
1785                checkForResize();
1786        }
1787        return val;
1788    }
1789
1790    /** Implementation for merge */
1791    @SuppressWarnings("unchecked") private final Object internalMerge
1792        (K k, V v, BiFun<? super V, ? super V, ? extends V> mf) {
1793        int h = spread(k.hashCode());
1794        Object val = null;
1795        int delta = 0;
1796        int count = 0;
1797        for (Node[] tab = table;;) {
1798            int i; Node f; int fh; Object fk, fv;
1799            if (tab == null)
1800                tab = initTable();
1801            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1802                if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
1803                    delta = 1;
1804                    val = v;
1805                    break;
1806                }
1807            }
1808            else if ((fh = f.hash) == MOVED) {
1809                if ((fk = f.key) instanceof TreeBin) {
1810                    TreeBin t = (TreeBin)fk;
1811                    t.acquire(0);
1812                    try {
1813                        if (tabAt(tab, i) == f) {
1814                            count = 1;
1815                            TreeNode p = t.getTreeNode(h, k, t.root);
1816                            val = (p == null) ? v : mf.apply((V)p.val, v);
1817                            if (val != null) {
1818                                if (p != null)
1819                                    p.val = val;
1820                                else {
1821                                    count = 2;
1822                                    delta = 1;
1823                                    t.putTreeNode(h, k, val);
1824                                }
1825                            }
1826                            else if (p != null) {
1827                                delta = -1;
1828                                t.deleteTreeNode(p);
1829                            }
1830                        }
1831                    } finally {
1832                        t.release(0);
1833                    }
1834                    if (count != 0)
1835                        break;
1836                }
1837                else
1838                    tab = (Node[])fk;
1839            }
1840            else if ((fh & LOCKED) != 0) {
1841                checkForResize();
1842                f.tryAwaitLock(tab, i);
1843            }
1844            else if (f.casHash(fh, fh | LOCKED)) {
1845                try {
1846                    if (tabAt(tab, i) == f) {
1847                        count = 1;
1848                        for (Node e = f, pred = null;; ++count) {
1849                            Object ek, ev;
1850                            if ((e.hash & HASH_BITS) == h &&
1851                                (ev = e.val) != null &&
1852                                ((ek = e.key) == k || k.equals(ek))) {
1853                                val = mf.apply(v, (V)ev);
1854                                if (val != null)
1855                                    e.val = val;
1856                                else {
1857                                    delta = -1;
1858                                    Node en = e.next;
1859                                    if (pred != null)
1860                                        pred.next = en;
1861                                    else
1862                                        setTabAt(tab, i, en);
1863                                }
1864                                break;
1865                            }
1866                            pred = e;
1867                            if ((e = e.next) == null) {
1868                                val = v;
1869                                pred.next = new Node(h, k, val, null);
1870                                delta = 1;
1871                                if (count >= TREE_THRESHOLD)
1872                                    replaceWithTreeBin(tab, i, k);
1873                                break;
1874                            }
1875                        }
1876                    }
1877                } finally {
1878                    if (!f.casHash(fh | LOCKED, fh)) {
1879                        f.hash = fh;
1880                        synchronized (f) { f.notifyAll(); };
1881                    }
1882                }
1883                if (count != 0) {
1884                    if (tab.length <= 64)
1885                        count = 2;
1886                    break;
1887                }
1888            }
1889        }
1890        if (delta != 0) {
1891            counter.add((long)delta);
1892            if (count > 1)
1893                checkForResize();
1894        }
1895        return val;
1896    }
1897
1898    /** Implementation for putAll */
1899    private final void internalPutAll(Map<?, ?> m) {
1900        tryPresize(m.size());
1901        long delta = 0L;     // number of uncommitted additions
1902        boolean npe = false; // to throw exception on exit for nulls
1903        try {                // to clean up counts on other exceptions
1904            for (Map.Entry<?, ?> entry : m.entrySet()) {
1905                Object k, v;
1906                if (entry == null || (k = entry.getKey()) == null ||
1907                    (v = entry.getValue()) == null) {
1908                    npe = true;
1909                    break;
1910                }
1911                int h = spread(k.hashCode());
1912                for (Node[] tab = table;;) {
1913                    int i; Node f; int fh; Object fk;
1914                    if (tab == null)
1915                        tab = initTable();
1916                    else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1917                        if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
1918                            ++delta;
1919                            break;
1920                        }
1921                    }
1922                    else if ((fh = f.hash) == MOVED) {
1923                        if ((fk = f.key) instanceof TreeBin) {
1924                            TreeBin t = (TreeBin)fk;
1925                            boolean validated = false;
1926                            t.acquire(0);
1927                            try {
1928                                if (tabAt(tab, i) == f) {
1929                                    validated = true;
1930                                    TreeNode p = t.getTreeNode(h, k, t.root);
1931                                    if (p != null)
1932                                        p.val = v;
1933                                    else {
1934                                        t.putTreeNode(h, k, v);
1935                                        ++delta;
1936                                    }
1937                                }
1938                            } finally {
1939                                t.release(0);
1940                            }
1941                            if (validated)
1942                                break;
1943                        }
1944                        else
1945                            tab = (Node[])fk;
1946                    }
1947                    else if ((fh & LOCKED) != 0) {
1948                        counter.add(delta);
1949                        delta = 0L;
1950                        checkForResize();
1951                        f.tryAwaitLock(tab, i);
1952                    }
1953                    else if (f.casHash(fh, fh | LOCKED)) {
1954                        int count = 0;
1955                        try {
1956                            if (tabAt(tab, i) == f) {
1957                                count = 1;
1958                                for (Node e = f;; ++count) {
1959                                    Object ek, ev;
1960                                    if ((e.hash & HASH_BITS) == h &&
1961                                        (ev = e.val) != null &&
1962                                        ((ek = e.key) == k || k.equals(ek))) {
1963                                        e.val = v;
1964                                        break;
1965                                    }
1966                                    Node last = e;
1967                                    if ((e = e.next) == null) {
1968                                        ++delta;
1969                                        last.next = new Node(h, k, v, null);
1970                                        if (count >= TREE_THRESHOLD)
1971                                            replaceWithTreeBin(tab, i, k);
1972                                        break;
1973                                    }
1974                                }
1975                            }
1976                        } finally {
1977                            if (!f.casHash(fh | LOCKED, fh)) {
1978                                f.hash = fh;
1979                                synchronized (f) { f.notifyAll(); };
1980                            }
1981                        }
1982                        if (count != 0) {
1983                            if (count > 1) {
1984                                counter.add(delta);
1985                                delta = 0L;
1986                                checkForResize();
1987                            }
1988                            break;
1989                        }
1990                    }
1991                }
1992            }
1993        } finally {
1994            if (delta != 0)
1995                counter.add(delta);
1996        }
1997        if (npe)
1998            throw new NullPointerException();
1999    }
2000
2001    /* ---------------- Table Initialization and Resizing -------------- */
2002
696      /**
697       * Returns a power of two table size for the given desired capacity.
698       * See Hackers Delight, sec 3.2
# Line 2015 | Line 708 | public class ConcurrentHashMapV8<K, V>
708      }
709  
710      /**
711 <     * Initializes table, using the size recorded in sizeCtl.
711 >     * Returns x's Class if it is of the form "class C implements
712 >     * Comparable<C>", else null.
713       */
714 <    private final Node[] initTable() {
715 <        Node[] tab; int sc;
716 <        while ((tab = table) == null) {
717 <            if ((sc = sizeCtl) < 0)
718 <                Thread.yield(); // lost initialization race; just spin
719 <            else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
720 <                try {
721 <                    if ((tab = table) == null) {
722 <                        int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
723 <                        tab = table = new Node[n];
724 <                        sc = n - (n >>> 2);
725 <                    }
726 <                } finally {
2033 <                    sizeCtl = sc;
714 >    static Class<?> comparableClassFor(Object x) {
715 >        if (x instanceof Comparable) {
716 >            Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
717 >            if ((c = x.getClass()) == String.class) // bypass checks
718 >                return c;
719 >            if ((ts = c.getGenericInterfaces()) != null) {
720 >                for (int i = 0; i < ts.length; ++i) {
721 >                    if (((t = ts[i]) instanceof ParameterizedType) &&
722 >                        ((p = (ParameterizedType)t).getRawType() ==
723 >                         Comparable.class) &&
724 >                        (as = p.getActualTypeArguments()) != null &&
725 >                        as.length == 1 && as[0] == c) // type arg is c
726 >                        return c;
727                  }
2035                break;
2036            }
2037        }
2038        return tab;
2039    }
2040
2041    /**
2042     * If table is too small and not already resizing, creates next
2043     * table and transfers bins.  Rechecks occupancy after a transfer
2044     * to see if another resize is already needed because resizings
2045     * are lagging additions.
2046     */
2047    private final void checkForResize() {
2048        Node[] tab; int n, sc;
2049        while ((tab = table) != null &&
2050               (n = tab.length) < MAXIMUM_CAPACITY &&
2051               (sc = sizeCtl) >= 0 && counter.sum() >= (long)sc &&
2052               UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2053            try {
2054                if (tab == table) {
2055                    table = rebuild(tab);
2056                    sc = (n << 1) - (n >>> 1);
2057                }
2058            } finally {
2059                sizeCtl = sc;
728              }
729          }
730 +        return null;
731      }
732  
733      /**
734 <     * Tries to presize table to accommodate the given number of elements.
735 <     *
2067 <     * @param size number of elements (doesn't need to be perfectly accurate)
734 >     * Returns k.compareTo(x) if x matches kc (k's screened comparable
735 >     * class), else 0.
736       */
737 <    private final void tryPresize(int size) {
738 <        int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
739 <            tableSizeFor(size + (size >>> 1) + 1);
740 <        int sc;
2073 <        while ((sc = sizeCtl) >= 0) {
2074 <            Node[] tab = table; int n;
2075 <            if (tab == null || (n = tab.length) == 0) {
2076 <                n = (sc > c) ? sc : c;
2077 <                if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2078 <                    try {
2079 <                        if (table == tab) {
2080 <                            table = new Node[n];
2081 <                            sc = n - (n >>> 2);
2082 <                        }
2083 <                    } finally {
2084 <                        sizeCtl = sc;
2085 <                    }
2086 <                }
2087 <            }
2088 <            else if (c <= sc || n >= MAXIMUM_CAPACITY)
2089 <                break;
2090 <            else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2091 <                try {
2092 <                    if (table == tab) {
2093 <                        table = rebuild(tab);
2094 <                        sc = (n << 1) - (n >>> 1);
2095 <                    }
2096 <                } finally {
2097 <                    sizeCtl = sc;
2098 <                }
2099 <            }
2100 <        }
737 >    @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
738 >    static int compareComparables(Class<?> kc, Object k, Object x) {
739 >        return (x == null || x.getClass() != kc ? 0 :
740 >                ((Comparable)k).compareTo(x));
741      }
742  
743 +    /* ---------------- Table element access -------------- */
744 +
745      /*
746 <     * Moves and/or copies the nodes in each bin to new table. See
747 <     * above for explanation.
748 <     *
749 <     * @return the new table
750 <     */
751 <    private static final Node[] rebuild(Node[] tab) {
752 <        int n = tab.length;
753 <        Node[] nextTab = new Node[n << 1];
754 <        Node fwd = new Node(MOVED, nextTab, null, null);
755 <        int[] buffer = null;       // holds bins to revisit; null until needed
756 <        Node rev = null;           // reverse forwarder; null until needed
757 <        int nbuffered = 0;         // the number of bins in buffer list
758 <        int bufferIndex = 0;       // buffer index of current buffered bin
759 <        int bin = n - 1;           // current non-buffered bin or -1 if none
760 <
761 <        for (int i = bin;;) {      // start upwards sweep
762 <            int fh; Node f;
763 <            if ((f = tabAt(tab, i)) == null) {
764 <                if (bin >= 0) {    // Unbuffered; no lock needed (or available)
765 <                    if (!casTabAt(tab, i, f, fwd))
766 <                        continue;
767 <                }
768 <                else {             // transiently use a locked forwarding node
2127 <                    Node g = new Node(MOVED|LOCKED, nextTab, null, null);
2128 <                    if (!casTabAt(tab, i, f, g))
2129 <                        continue;
2130 <                    setTabAt(nextTab, i, null);
2131 <                    setTabAt(nextTab, i + n, null);
2132 <                    setTabAt(tab, i, fwd);
2133 <                    if (!g.casHash(MOVED|LOCKED, MOVED)) {
2134 <                        g.hash = MOVED;
2135 <                        synchronized (g) { g.notifyAll(); }
2136 <                    }
2137 <                }
2138 <            }
2139 <            else if ((fh = f.hash) == MOVED) {
2140 <                Object fk = f.key;
2141 <                if (fk instanceof TreeBin) {
2142 <                    TreeBin t = (TreeBin)fk;
2143 <                    boolean validated = false;
2144 <                    t.acquire(0);
2145 <                    try {
2146 <                        if (tabAt(tab, i) == f) {
2147 <                            validated = true;
2148 <                            splitTreeBin(nextTab, i, t);
2149 <                            setTabAt(tab, i, fwd);
2150 <                        }
2151 <                    } finally {
2152 <                        t.release(0);
2153 <                    }
2154 <                    if (!validated)
2155 <                        continue;
2156 <                }
2157 <            }
2158 <            else if ((fh & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) {
2159 <                boolean validated = false;
2160 <                try {              // split to lo and hi lists; copying as needed
2161 <                    if (tabAt(tab, i) == f) {
2162 <                        validated = true;
2163 <                        splitBin(nextTab, i, f);
2164 <                        setTabAt(tab, i, fwd);
2165 <                    }
2166 <                } finally {
2167 <                    if (!f.casHash(fh | LOCKED, fh)) {
2168 <                        f.hash = fh;
2169 <                        synchronized (f) { f.notifyAll(); };
2170 <                    }
2171 <                }
2172 <                if (!validated)
2173 <                    continue;
2174 <            }
2175 <            else {
2176 <                if (buffer == null) // initialize buffer for revisits
2177 <                    buffer = new int[TRANSFER_BUFFER_SIZE];
2178 <                if (bin < 0 && bufferIndex > 0) {
2179 <                    int j = buffer[--bufferIndex];
2180 <                    buffer[bufferIndex] = i;
2181 <                    i = j;         // swap with another bin
2182 <                    continue;
2183 <                }
2184 <                if (bin < 0 || nbuffered >= TRANSFER_BUFFER_SIZE) {
2185 <                    f.tryAwaitLock(tab, i);
2186 <                    continue;      // no other options -- block
2187 <                }
2188 <                if (rev == null)   // initialize reverse-forwarder
2189 <                    rev = new Node(MOVED, tab, null, null);
2190 <                if (tabAt(tab, i) != f || (f.hash & LOCKED) == 0)
2191 <                    continue;      // recheck before adding to list
2192 <                buffer[nbuffered++] = i;
2193 <                setTabAt(nextTab, i, rev);     // install place-holders
2194 <                setTabAt(nextTab, i + n, rev);
2195 <            }
2196 <
2197 <            if (bin > 0)
2198 <                i = --bin;
2199 <            else if (buffer != null && nbuffered > 0) {
2200 <                bin = -1;
2201 <                i = buffer[bufferIndex = --nbuffered];
2202 <            }
2203 <            else
2204 <                return nextTab;
2205 <        }
746 >     * Volatile access methods are used for table elements as well as
747 >     * elements of in-progress next table while resizing.  All uses of
748 >     * the tab arguments must be null checked by callers.  All callers
749 >     * also paranoically precheck that tab's length is not zero (or an
750 >     * equivalent check), thus ensuring that any index argument taking
751 >     * the form of a hash value anded with (length - 1) is a valid
752 >     * index.  Note that, to be correct wrt arbitrary concurrency
753 >     * errors by users, these checks must operate on local variables,
754 >     * which accounts for some odd-looking inline assignments below.
755 >     * Note that calls to setTabAt always occur within locked regions,
756 >     * and so in principle require only release ordering, not
757 >     * full volatile semantics, but are currently coded as volatile
758 >     * writes to be conservative.
759 >     */
760 >
761 >    @SuppressWarnings("unchecked")
762 >    static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
763 >        return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
764 >    }
765 >
766 >    static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
767 >                                        Node<K,V> c, Node<K,V> v) {
768 >        return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
769      }
770  
771 <    /**
772 <     * Splits a normal bin with list headed by e into lo and hi parts;
2210 <     * installs in given table.
2211 <     */
2212 <    private static void splitBin(Node[] nextTab, int i, Node e) {
2213 <        int bit = nextTab.length >>> 1; // bit to split on
2214 <        int runBit = e.hash & bit;
2215 <        Node lastRun = e, lo = null, hi = null;
2216 <        for (Node p = e.next; p != null; p = p.next) {
2217 <            int b = p.hash & bit;
2218 <            if (b != runBit) {
2219 <                runBit = b;
2220 <                lastRun = p;
2221 <            }
2222 <        }
2223 <        if (runBit == 0)
2224 <            lo = lastRun;
2225 <        else
2226 <            hi = lastRun;
2227 <        for (Node p = e; p != lastRun; p = p.next) {
2228 <            int ph = p.hash & HASH_BITS;
2229 <            Object pk = p.key, pv = p.val;
2230 <            if ((ph & bit) == 0)
2231 <                lo = new Node(ph, pk, pv, lo);
2232 <            else
2233 <                hi = new Node(ph, pk, pv, hi);
2234 <        }
2235 <        setTabAt(nextTab, i, lo);
2236 <        setTabAt(nextTab, i + bit, hi);
771 >    static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
772 >        U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
773      }
774  
775 +    /* ---------------- Fields -------------- */
776 +
777      /**
778 <     * Splits a tree bin into lo and hi parts; installs in given table.
778 >     * The array of bins. Lazily initialized upon first insertion.
779 >     * Size is always a power of two. Accessed directly by iterators.
780       */
781 <    private static void splitTreeBin(Node[] nextTab, int i, TreeBin t) {
2243 <        int bit = nextTab.length >>> 1;
2244 <        TreeBin lt = new TreeBin();
2245 <        TreeBin ht = new TreeBin();
2246 <        int lc = 0, hc = 0;
2247 <        for (Node e = t.first; e != null; e = e.next) {
2248 <            int h = e.hash & HASH_BITS;
2249 <            Object k = e.key, v = e.val;
2250 <            if ((h & bit) == 0) {
2251 <                ++lc;
2252 <                lt.putTreeNode(h, k, v);
2253 <            }
2254 <            else {
2255 <                ++hc;
2256 <                ht.putTreeNode(h, k, v);
2257 <            }
2258 <        }
2259 <        Node ln, hn; // throw away trees if too small
2260 <        if (lc <= (TREE_THRESHOLD >>> 1)) {
2261 <            ln = null;
2262 <            for (Node p = lt.first; p != null; p = p.next)
2263 <                ln = new Node(p.hash, p.key, p.val, ln);
2264 <        }
2265 <        else
2266 <            ln = new Node(MOVED, lt, null, null);
2267 <        setTabAt(nextTab, i, ln);
2268 <        if (hc <= (TREE_THRESHOLD >>> 1)) {
2269 <            hn = null;
2270 <            for (Node p = ht.first; p != null; p = p.next)
2271 <                hn = new Node(p.hash, p.key, p.val, hn);
2272 <        }
2273 <        else
2274 <            hn = new Node(MOVED, ht, null, null);
2275 <        setTabAt(nextTab, i + bit, hn);
2276 <    }
781 >    transient volatile Node<K,V>[] table;
782  
783      /**
784 <     * Implementation for clear. Steps through each bin, removing all
2280 <     * nodes.
784 >     * The next table to use; non-null only while resizing.
785       */
786 <    private final void internalClear() {
2283 <        long delta = 0L; // negative number of deletions
2284 <        int i = 0;
2285 <        Node[] tab = table;
2286 <        while (tab != null && i < tab.length) {
2287 <            int fh; Object fk;
2288 <            Node f = tabAt(tab, i);
2289 <            if (f == null)
2290 <                ++i;
2291 <            else if ((fh = f.hash) == MOVED) {
2292 <                if ((fk = f.key) instanceof TreeBin) {
2293 <                    TreeBin t = (TreeBin)fk;
2294 <                    t.acquire(0);
2295 <                    try {
2296 <                        if (tabAt(tab, i) == f) {
2297 <                            for (Node p = t.first; p != null; p = p.next) {
2298 <                                if (p.val != null) { // (currently always true)
2299 <                                    p.val = null;
2300 <                                    --delta;
2301 <                                }
2302 <                            }
2303 <                            t.first = null;
2304 <                            t.root = null;
2305 <                            ++i;
2306 <                        }
2307 <                    } finally {
2308 <                        t.release(0);
2309 <                    }
2310 <                }
2311 <                else
2312 <                    tab = (Node[])fk;
2313 <            }
2314 <            else if ((fh & LOCKED) != 0) {
2315 <                counter.add(delta); // opportunistically update count
2316 <                delta = 0L;
2317 <                f.tryAwaitLock(tab, i);
2318 <            }
2319 <            else if (f.casHash(fh, fh | LOCKED)) {
2320 <                try {
2321 <                    if (tabAt(tab, i) == f) {
2322 <                        for (Node e = f; e != null; e = e.next) {
2323 <                            if (e.val != null) {  // (currently always true)
2324 <                                e.val = null;
2325 <                                --delta;
2326 <                            }
2327 <                        }
2328 <                        setTabAt(tab, i, null);
2329 <                        ++i;
2330 <                    }
2331 <                } finally {
2332 <                    if (!f.casHash(fh | LOCKED, fh)) {
2333 <                        f.hash = fh;
2334 <                        synchronized (f) { f.notifyAll(); };
2335 <                    }
2336 <                }
2337 <            }
2338 <        }
2339 <        if (delta != 0)
2340 <            counter.add(delta);
2341 <    }
2342 <
2343 <    /* ----------------Table Traversal -------------- */
786 >    private transient volatile Node<K,V>[] nextTable;
787  
788      /**
789 <     * Encapsulates traversal for methods such as containsValue; also
790 <     * serves as a base class for other iterators and bulk tasks.
791 <     *
792 <     * At each step, the iterator snapshots the key ("nextKey") and
793 <     * value ("nextVal") of a valid node (i.e., one that, at point of
2351 <     * snapshot, has a non-null user value). Because val fields can
2352 <     * change (including to null, indicating deletion), field nextVal
2353 <     * might not be accurate at point of use, but still maintains the
2354 <     * weak consistency property of holding a value that was once
2355 <     * valid. To support iterator.remove, the nextKey field is not
2356 <     * updated (nulled out) when the iterator cannot advance.
2357 <     *
2358 <     * Internal traversals directly access these fields, as in:
2359 <     * {@code while (it.advance() != null) { process(it.nextKey); }}
2360 <     *
2361 <     * Exported iterators must track whether the iterator has advanced
2362 <     * (in hasNext vs next) (by setting/checking/nulling field
2363 <     * nextVal), and then extract key, value, or key-value pairs as
2364 <     * return values of next().
2365 <     *
2366 <     * The iterator visits once each still-valid node that was
2367 <     * reachable upon iterator construction. It might miss some that
2368 <     * were added to a bin after the bin was visited, which is OK wrt
2369 <     * consistency guarantees. Maintaining this property in the face
2370 <     * of possible ongoing resizes requires a fair amount of
2371 <     * bookkeeping state that is difficult to optimize away amidst
2372 <     * volatile accesses.  Even so, traversal maintains reasonable
2373 <     * throughput.
2374 <     *
2375 <     * Normally, iteration proceeds bin-by-bin traversing lists.
2376 <     * However, if the table has been resized, then all future steps
2377 <     * must traverse both the bin at the current index as well as at
2378 <     * (index + baseSize); and so on for further resizings. To
2379 <     * paranoically cope with potential sharing by users of iterators
2380 <     * across threads, iteration terminates if a bounds checks fails
2381 <     * for a table read.
2382 <     *
2383 <     * This class extends ForkJoinTask to streamline parallel
2384 <     * iteration in bulk operations (see BulkTask). This adds only an
2385 <     * int of space overhead, which is close enough to negligible in
2386 <     * cases where it is not needed to not worry about it.  Because
2387 <     * ForkJoinTask is Serializable, but iterators need not be, we
2388 <     * need to add warning suppressions.
2389 <     */
2390 <    @SuppressWarnings("serial") static class Traverser<K,V,R> extends ForkJoinTask<R> {
2391 <        final ConcurrentHashMapV8<K, V> map;
2392 <        Node next;           // the next entry to use
2393 <        Object nextKey;      // cached key field of next
2394 <        Object nextVal;      // cached val field of next
2395 <        Node[] tab;          // current table; updated if resized
2396 <        int index;           // index of bin to use next
2397 <        int baseIndex;       // current index of initial table
2398 <        int baseLimit;       // index bound for initial table
2399 <        int baseSize;        // initial table size
789 >     * Base counter value, used mainly when there is no contention,
790 >     * but also as a fallback during table initialization
791 >     * races. Updated via CAS.
792 >     */
793 >    private transient volatile long baseCount;
794  
795 <        /** Creates iterator for all entries in the table. */
796 <        Traverser(ConcurrentHashMapV8<K, V> map) {
797 <            this.map = map;
798 <        }
795 >    /**
796 >     * Table initialization and resizing control.  When negative, the
797 >     * table is being initialized or resized: -1 for initialization,
798 >     * else -(1 + the number of active resizing threads).  Otherwise,
799 >     * when table is null, holds the initial table size to use upon
800 >     * creation, or 0 for default. After initialization, holds the
801 >     * next element count value upon which to resize the table.
802 >     */
803 >    private transient volatile int sizeCtl;
804  
805 <        /** Creates iterator for split() methods */
806 <        Traverser(Traverser<K,V,?> it) {
807 <            ConcurrentHashMapV8<K, V> m; Node[] t;
808 <            if ((m = this.map = it.map) == null)
2410 <                t = null;
2411 <            else if ((t = it.tab) == null && // force parent tab initialization
2412 <                     (t = it.tab = m.table) != null)
2413 <                it.baseLimit = it.baseSize = t.length;
2414 <            this.tab = t;
2415 <            this.baseSize = it.baseSize;
2416 <            it.baseLimit = this.index = this.baseIndex =
2417 <                ((this.baseLimit = it.baseLimit) + it.baseIndex + 1) >>> 1;
2418 <        }
805 >    /**
806 >     * The next table index (plus one) to split while resizing.
807 >     */
808 >    private transient volatile int transferIndex;
809  
810 <        /**
811 <         * Advances next; returns nextVal or null if terminated.
812 <         * See above for explanation.
813 <         */
2424 <        final Object advance() {
2425 <            Node e = next;
2426 <            Object ev = null;
2427 <            outer: do {
2428 <                if (e != null)                  // advance past used/skipped node
2429 <                    e = e.next;
2430 <                while (e == null) {             // get to next non-null bin
2431 <                    ConcurrentHashMapV8<K, V> m;
2432 <                    Node[] t; int b, i, n; Object ek; // checks must use locals
2433 <                    if ((t = tab) != null)
2434 <                        n = t.length;
2435 <                    else if ((m = map) != null && (t = tab = m.table) != null)
2436 <                        n = baseLimit = baseSize = t.length;
2437 <                    else
2438 <                        break outer;
2439 <                    if ((b = baseIndex) >= baseLimit ||
2440 <                        (i = index) < 0 || i >= n)
2441 <                        break outer;
2442 <                    if ((e = tabAt(t, i)) != null && e.hash == MOVED) {
2443 <                        if ((ek = e.key) instanceof TreeBin)
2444 <                            e = ((TreeBin)ek).first;
2445 <                        else {
2446 <                            tab = (Node[])ek;
2447 <                            continue;           // restarts due to null val
2448 <                        }
2449 <                    }                           // visit upper slots if present
2450 <                    index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2451 <                }
2452 <                nextKey = e.key;
2453 <            } while ((ev = e.val) == null);    // skip deleted or special nodes
2454 <            next = e;
2455 <            return nextVal = ev;
2456 <        }
810 >    /**
811 >     * Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
812 >     */
813 >    private transient volatile int cellsBusy;
814  
815 <        public final void remove() {
816 <            Object k = nextKey;
817 <            if (k == null && (advance() == null || (k = nextKey) == null))
818 <                throw new IllegalStateException();
2462 <            map.internalReplace(k, null, null);
2463 <        }
815 >    /**
816 >     * Table of counter cells. When non-null, size is a power of 2.
817 >     */
818 >    private transient volatile CounterCell[] counterCells;
819  
820 <        public final boolean hasNext() {
821 <            return nextVal != null || advance() != null;
822 <        }
820 >    // views
821 >    private transient KeySetView<K,V> keySet;
822 >    private transient ValuesView<K,V> values;
823 >    private transient EntrySetView<K,V> entrySet;
824  
2469        public final boolean hasMoreElements() { return hasNext(); }
2470        public final void setRawResult(Object x) { }
2471        public R getRawResult() { return null; }
2472        public boolean exec() { return true; }
2473    }
825  
826      /* ---------------- Public operations -------------- */
827  
# Line 2478 | Line 829 | public class ConcurrentHashMapV8<K, V>
829       * Creates a new, empty map with the default initial table size (16).
830       */
831      public ConcurrentHashMapV8() {
2481        this.counter = new LongAdder();
832      }
833  
834      /**
# Line 2497 | Line 847 | public class ConcurrentHashMapV8<K, V>
847          int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
848                     MAXIMUM_CAPACITY :
849                     tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2500        this.counter = new LongAdder();
850          this.sizeCtl = cap;
851      }
852  
# Line 2507 | Line 856 | public class ConcurrentHashMapV8<K, V>
856       * @param m the map
857       */
858      public ConcurrentHashMapV8(Map<? extends K, ? extends V> m) {
2510        this.counter = new LongAdder();
859          this.sizeCtl = DEFAULT_CAPACITY;
860 <        internalPutAll(m);
860 >        putAll(m);
861      }
862  
863      /**
# Line 2550 | Line 898 | public class ConcurrentHashMapV8<K, V>
898       * nonpositive
899       */
900      public ConcurrentHashMapV8(int initialCapacity,
901 <                               float loadFactor, int concurrencyLevel) {
901 >                             float loadFactor, int concurrencyLevel) {
902          if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
903              throw new IllegalArgumentException();
904          if (initialCapacity < concurrencyLevel)   // Use at least as many bins
# Line 2558 | Line 906 | public class ConcurrentHashMapV8<K, V>
906          long size = (long)(1.0 + (long)initialCapacity / loadFactor);
907          int cap = (size >= (long)MAXIMUM_CAPACITY) ?
908              MAXIMUM_CAPACITY : tableSizeFor((int)size);
2561        this.counter = new LongAdder();
909          this.sizeCtl = cap;
910      }
911  
912 <    /**
2566 <     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2567 <     * from the given type to {@code Boolean.TRUE}.
2568 <     *
2569 <     * @return the new set
2570 <     */
2571 <    public static <K> KeySetView<K,Boolean> newKeySet() {
2572 <        return new KeySetView<K,Boolean>(new ConcurrentHashMapV8<K,Boolean>(),
2573 <                                      Boolean.TRUE);
2574 <    }
2575 <
2576 <    /**
2577 <     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2578 <     * from the given type to {@code Boolean.TRUE}.
2579 <     *
2580 <     * @param initialCapacity The implementation performs internal
2581 <     * sizing to accommodate this many elements.
2582 <     * @throws IllegalArgumentException if the initial capacity of
2583 <     * elements is negative
2584 <     * @return the new set
2585 <     */
2586 <    public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2587 <        return new KeySetView<K,Boolean>(new ConcurrentHashMapV8<K,Boolean>(initialCapacity),
2588 <                                      Boolean.TRUE);
2589 <    }
2590 <
2591 <    /**
2592 <     * {@inheritDoc}
2593 <     */
2594 <    public boolean isEmpty() {
2595 <        return counter.sum() <= 0L; // ignore transient negative values
2596 <    }
912 >    // Original (since JDK1.2) Map methods
913  
914      /**
915       * {@inheritDoc}
916       */
917      public int size() {
918 <        long n = counter.sum();
918 >        long n = sumCount();
919          return ((n < 0L) ? 0 :
920                  (n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
921                  (int)n);
922      }
923  
924      /**
925 <     * Returns the number of mappings. This method should be used
2610 <     * instead of {@link #size} because a ConcurrentHashMapV8 may
2611 <     * contain more mappings than can be represented as an int. The
2612 <     * value returned is a snapshot; the actual count may differ if
2613 <     * there are ongoing concurrent insertions or removals.
2614 <     *
2615 <     * @return the number of mappings
925 >     * {@inheritDoc}
926       */
927 <    public long mappingCount() {
928 <        long n = counter.sum();
2619 <        return (n < 0L) ? 0L : n; // ignore transient negative values
927 >    public boolean isEmpty() {
928 >        return sumCount() <= 0L; // ignore transient negative values
929      }
930  
931      /**
# Line 2630 | Line 939 | public class ConcurrentHashMapV8<K, V>
939       *
940       * @throws NullPointerException if the specified key is null
941       */
942 <    @SuppressWarnings("unchecked") public V get(Object key) {
943 <        if (key == null)
944 <            throw new NullPointerException();
945 <        return (V)internalGet(key);
946 <    }
947 <
948 <    /**
949 <     * Returns the value to which the specified key is mapped,
950 <     * or the given defaultValue if this map contains no mapping for the key.
951 <     *
952 <     * @param key the key
953 <     * @param defaultValue the value to return if this map contains
954 <     * no mapping for the given key
955 <     * @return the mapping for the key, if present; else the defaultValue
956 <     * @throws NullPointerException if the specified key is null
957 <     */
958 <    @SuppressWarnings("unchecked") public V getValueOrDefault(Object key, V defaultValue) {
959 <        if (key == null)
2651 <            throw new NullPointerException();
2652 <        V v = (V) internalGet(key);
2653 <        return v == null ? defaultValue : v;
942 >    public V get(Object key) {
943 >        Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
944 >        int h = spread(key.hashCode());
945 >        if ((tab = table) != null && (n = tab.length) > 0 &&
946 >            (e = tabAt(tab, (n - 1) & h)) != null) {
947 >            if ((eh = e.hash) == h) {
948 >                if ((ek = e.key) == key || (ek != null && key.equals(ek)))
949 >                    return e.val;
950 >            }
951 >            else if (eh < 0)
952 >                return (p = e.find(h, key)) != null ? p.val : null;
953 >            while ((e = e.next) != null) {
954 >                if (e.hash == h &&
955 >                    ((ek = e.key) == key || (ek != null && key.equals(ek))))
956 >                    return e.val;
957 >            }
958 >        }
959 >        return null;
960      }
961  
962      /**
963       * Tests if the specified object is a key in this table.
964       *
965 <     * @param  key   possible key
965 >     * @param  key possible key
966       * @return {@code true} if and only if the specified object
967       *         is a key in this table, as determined by the
968       *         {@code equals} method; {@code false} otherwise
969       * @throws NullPointerException if the specified key is null
970       */
971      public boolean containsKey(Object key) {
972 <        if (key == null)
2667 <            throw new NullPointerException();
2668 <        return internalGet(key) != null;
972 >        return get(key) != null;
973      }
974  
975      /**
# Line 2681 | Line 985 | public class ConcurrentHashMapV8<K, V>
985      public boolean containsValue(Object value) {
986          if (value == null)
987              throw new NullPointerException();
988 <        Object v;
989 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
990 <        while ((v = it.advance()) != null) {
991 <            if (v == value || value.equals(v))
992 <                return true;
988 >        Node<K,V>[] t;
989 >        if ((t = table) != null) {
990 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
991 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
992 >                V v;
993 >                if ((v = p.val) == value || (v != null && value.equals(v)))
994 >                    return true;
995 >            }
996          }
997          return false;
998      }
999  
1000      /**
2694     * Legacy method testing if some key maps into the specified value
2695     * in this table.  This method is identical in functionality to
2696     * {@link #containsValue}, and exists solely to ensure
2697     * full compatibility with class {@link java.util.Hashtable},
2698     * which supported this method prior to introduction of the
2699     * Java Collections framework.
2700     *
2701     * @param  value a value to search for
2702     * @return {@code true} if and only if some key maps to the
2703     *         {@code value} argument in this table as
2704     *         determined by the {@code equals} method;
2705     *         {@code false} otherwise
2706     * @throws NullPointerException if the specified value is null
2707     */
2708    public boolean contains(Object value) {
2709        return containsValue(value);
2710    }
2711
2712    /**
1001       * Maps the specified key to the specified value in this table.
1002       * Neither the key nor the value can be null.
1003       *
1004 <     * <p> The value can be retrieved by calling the {@code get} method
1004 >     * <p>The value can be retrieved by calling the {@code get} method
1005       * with a key that is equal to the original key.
1006       *
1007       * @param key key with which the specified value is to be associated
# Line 2722 | Line 1010 | public class ConcurrentHashMapV8<K, V>
1010       *         {@code null} if there was no mapping for {@code key}
1011       * @throws NullPointerException if the specified key or value is null
1012       */
1013 <    @SuppressWarnings("unchecked") public V put(K key, V value) {
1014 <        if (key == null || value == null)
1013 >    public V put(K key, V value) {
1014 >        return putVal(key, value, false);
1015 >    }
1016 >
1017 >    /** Implementation for put and putIfAbsent */
1018 >    final V putVal(K key, V value, boolean onlyIfAbsent) {
1019 >        if (key == null || value == null) throw new NullPointerException();
1020 >        int hash = spread(key.hashCode());
1021 >        int binCount = 0;
1022 >        for (Node<K,V>[] tab = table;;) {
1023 >            Node<K,V> f; int n, i, fh;
1024 >            if (tab == null || (n = tab.length) == 0)
1025 >                tab = initTable();
1026 >            else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1027 >                if (casTabAt(tab, i, null,
1028 >                             new Node<K,V>(hash, key, value, null)))
1029 >                    break;                   // no lock when adding to empty bin
1030 >            }
1031 >            else if ((fh = f.hash) == MOVED)
1032 >                tab = helpTransfer(tab, f);
1033 >            else {
1034 >                V oldVal = null;
1035 >                synchronized (f) {
1036 >                    if (tabAt(tab, i) == f) {
1037 >                        if (fh >= 0) {
1038 >                            binCount = 1;
1039 >                            for (Node<K,V> e = f;; ++binCount) {
1040 >                                K ek;
1041 >                                if (e.hash == hash &&
1042 >                                    ((ek = e.key) == key ||
1043 >                                     (ek != null && key.equals(ek)))) {
1044 >                                    oldVal = e.val;
1045 >                                    if (!onlyIfAbsent)
1046 >                                        e.val = value;
1047 >                                    break;
1048 >                                }
1049 >                                Node<K,V> pred = e;
1050 >                                if ((e = e.next) == null) {
1051 >                                    pred.next = new Node<K,V>(hash, key,
1052 >                                                              value, null);
1053 >                                    break;
1054 >                                }
1055 >                            }
1056 >                        }
1057 >                        else if (f instanceof TreeBin) {
1058 >                            Node<K,V> p;
1059 >                            binCount = 2;
1060 >                            if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1061 >                                                           value)) != null) {
1062 >                                oldVal = p.val;
1063 >                                if (!onlyIfAbsent)
1064 >                                    p.val = value;
1065 >                            }
1066 >                        }
1067 >                    }
1068 >                }
1069 >                if (binCount != 0) {
1070 >                    if (binCount >= TREEIFY_THRESHOLD)
1071 >                        treeifyBin(tab, i);
1072 >                    if (oldVal != null)
1073 >                        return oldVal;
1074 >                    break;
1075 >                }
1076 >            }
1077 >        }
1078 >        addCount(1L, binCount);
1079 >        return null;
1080 >    }
1081 >
1082 >    /**
1083 >     * Copies all of the mappings from the specified map to this one.
1084 >     * These mappings replace any mappings that this map had for any of the
1085 >     * keys currently in the specified map.
1086 >     *
1087 >     * @param m mappings to be stored in this map
1088 >     */
1089 >    public void putAll(Map<? extends K, ? extends V> m) {
1090 >        tryPresize(m.size());
1091 >        for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1092 >            putVal(e.getKey(), e.getValue(), false);
1093 >    }
1094 >
1095 >    /**
1096 >     * Removes the key (and its corresponding value) from this map.
1097 >     * This method does nothing if the key is not in the map.
1098 >     *
1099 >     * @param  key the key that needs to be removed
1100 >     * @return the previous value associated with {@code key}, or
1101 >     *         {@code null} if there was no mapping for {@code key}
1102 >     * @throws NullPointerException if the specified key is null
1103 >     */
1104 >    public V remove(Object key) {
1105 >        return replaceNode(key, null, null);
1106 >    }
1107 >
1108 >    /**
1109 >     * Implementation for the four public remove/replace methods:
1110 >     * Replaces node value with v, conditional upon match of cv if
1111 >     * non-null.  If resulting value is null, delete.
1112 >     */
1113 >    final V replaceNode(Object key, V value, Object cv) {
1114 >        int hash = spread(key.hashCode());
1115 >        for (Node<K,V>[] tab = table;;) {
1116 >            Node<K,V> f; int n, i, fh;
1117 >            if (tab == null || (n = tab.length) == 0 ||
1118 >                (f = tabAt(tab, i = (n - 1) & hash)) == null)
1119 >                break;
1120 >            else if ((fh = f.hash) == MOVED)
1121 >                tab = helpTransfer(tab, f);
1122 >            else {
1123 >                V oldVal = null;
1124 >                boolean validated = false;
1125 >                synchronized (f) {
1126 >                    if (tabAt(tab, i) == f) {
1127 >                        if (fh >= 0) {
1128 >                            validated = true;
1129 >                            for (Node<K,V> e = f, pred = null;;) {
1130 >                                K ek;
1131 >                                if (e.hash == hash &&
1132 >                                    ((ek = e.key) == key ||
1133 >                                     (ek != null && key.equals(ek)))) {
1134 >                                    V ev = e.val;
1135 >                                    if (cv == null || cv == ev ||
1136 >                                        (ev != null && cv.equals(ev))) {
1137 >                                        oldVal = ev;
1138 >                                        if (value != null)
1139 >                                            e.val = value;
1140 >                                        else if (pred != null)
1141 >                                            pred.next = e.next;
1142 >                                        else
1143 >                                            setTabAt(tab, i, e.next);
1144 >                                    }
1145 >                                    break;
1146 >                                }
1147 >                                pred = e;
1148 >                                if ((e = e.next) == null)
1149 >                                    break;
1150 >                            }
1151 >                        }
1152 >                        else if (f instanceof TreeBin) {
1153 >                            validated = true;
1154 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1155 >                            TreeNode<K,V> r, p;
1156 >                            if ((r = t.root) != null &&
1157 >                                (p = r.findTreeNode(hash, key, null)) != null) {
1158 >                                V pv = p.val;
1159 >                                if (cv == null || cv == pv ||
1160 >                                    (pv != null && cv.equals(pv))) {
1161 >                                    oldVal = pv;
1162 >                                    if (value != null)
1163 >                                        p.val = value;
1164 >                                    else if (t.removeTreeNode(p))
1165 >                                        setTabAt(tab, i, untreeify(t.first));
1166 >                                }
1167 >                            }
1168 >                        }
1169 >                    }
1170 >                }
1171 >                if (validated) {
1172 >                    if (oldVal != null) {
1173 >                        if (value == null)
1174 >                            addCount(-1L, -1);
1175 >                        return oldVal;
1176 >                    }
1177 >                    break;
1178 >                }
1179 >            }
1180 >        }
1181 >        return null;
1182 >    }
1183 >
1184 >    /**
1185 >     * Removes all of the mappings from this map.
1186 >     */
1187 >    public void clear() {
1188 >        long delta = 0L; // negative number of deletions
1189 >        int i = 0;
1190 >        Node<K,V>[] tab = table;
1191 >        while (tab != null && i < tab.length) {
1192 >            int fh;
1193 >            Node<K,V> f = tabAt(tab, i);
1194 >            if (f == null)
1195 >                ++i;
1196 >            else if ((fh = f.hash) == MOVED) {
1197 >                tab = helpTransfer(tab, f);
1198 >                i = 0; // restart
1199 >            }
1200 >            else {
1201 >                synchronized (f) {
1202 >                    if (tabAt(tab, i) == f) {
1203 >                        Node<K,V> p = (fh >= 0 ? f :
1204 >                                       (f instanceof TreeBin) ?
1205 >                                       ((TreeBin<K,V>)f).first : null);
1206 >                        while (p != null) {
1207 >                            --delta;
1208 >                            p = p.next;
1209 >                        }
1210 >                        setTabAt(tab, i++, null);
1211 >                    }
1212 >                }
1213 >            }
1214 >        }
1215 >        if (delta != 0L)
1216 >            addCount(delta, -1);
1217 >    }
1218 >
1219 >    /**
1220 >     * Returns a {@link Set} view of the keys contained in this map.
1221 >     * The set is backed by the map, so changes to the map are
1222 >     * reflected in the set, and vice-versa. The set supports element
1223 >     * removal, which removes the corresponding mapping from this map,
1224 >     * via the {@code Iterator.remove}, {@code Set.remove},
1225 >     * {@code removeAll}, {@code retainAll}, and {@code clear}
1226 >     * operations.  It does not support the {@code add} or
1227 >     * {@code addAll} operations.
1228 >     *
1229 >     * <p>The view's {@code iterator} is a "weakly consistent" iterator
1230 >     * that will never throw {@link ConcurrentModificationException},
1231 >     * and guarantees to traverse elements as they existed upon
1232 >     * construction of the iterator, and may (but is not guaranteed to)
1233 >     * reflect any modifications subsequent to construction.
1234 >     *
1235 >     * @return the set view
1236 >     */
1237 >    public KeySetView<K,V> keySet() {
1238 >        KeySetView<K,V> ks;
1239 >        return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1240 >    }
1241 >
1242 >    /**
1243 >     * Returns a {@link Collection} view of the values contained in this map.
1244 >     * The collection is backed by the map, so changes to the map are
1245 >     * reflected in the collection, and vice-versa.  The collection
1246 >     * supports element removal, which removes the corresponding
1247 >     * mapping from this map, via the {@code Iterator.remove},
1248 >     * {@code Collection.remove}, {@code removeAll},
1249 >     * {@code retainAll}, and {@code clear} operations.  It does not
1250 >     * support the {@code add} or {@code addAll} operations.
1251 >     *
1252 >     * <p>The view's {@code iterator} is a "weakly consistent" iterator
1253 >     * that will never throw {@link ConcurrentModificationException},
1254 >     * and guarantees to traverse elements as they existed upon
1255 >     * construction of the iterator, and may (but is not guaranteed to)
1256 >     * reflect any modifications subsequent to construction.
1257 >     *
1258 >     * @return the collection view
1259 >     */
1260 >    public Collection<V> values() {
1261 >        ValuesView<K,V> vs;
1262 >        return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1263 >    }
1264 >
1265 >    /**
1266 >     * Returns a {@link Set} view of the mappings contained in this map.
1267 >     * The set is backed by the map, so changes to the map are
1268 >     * reflected in the set, and vice-versa.  The set supports element
1269 >     * removal, which removes the corresponding mapping from the map,
1270 >     * via the {@code Iterator.remove}, {@code Set.remove},
1271 >     * {@code removeAll}, {@code retainAll}, and {@code clear}
1272 >     * operations.
1273 >     *
1274 >     * <p>The view's {@code iterator} is a "weakly consistent" iterator
1275 >     * that will never throw {@link ConcurrentModificationException},
1276 >     * and guarantees to traverse elements as they existed upon
1277 >     * construction of the iterator, and may (but is not guaranteed to)
1278 >     * reflect any modifications subsequent to construction.
1279 >     *
1280 >     * @return the set view
1281 >     */
1282 >    public Set<Map.Entry<K,V>> entrySet() {
1283 >        EntrySetView<K,V> es;
1284 >        return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1285 >    }
1286 >
1287 >    /**
1288 >     * Returns the hash code value for this {@link Map}, i.e.,
1289 >     * the sum of, for each key-value pair in the map,
1290 >     * {@code key.hashCode() ^ value.hashCode()}.
1291 >     *
1292 >     * @return the hash code value for this map
1293 >     */
1294 >    public int hashCode() {
1295 >        int h = 0;
1296 >        Node<K,V>[] t;
1297 >        if ((t = table) != null) {
1298 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1299 >            for (Node<K,V> p; (p = it.advance()) != null; )
1300 >                h += p.key.hashCode() ^ p.val.hashCode();
1301 >        }
1302 >        return h;
1303 >    }
1304 >
1305 >    /**
1306 >     * Returns a string representation of this map.  The string
1307 >     * representation consists of a list of key-value mappings (in no
1308 >     * particular order) enclosed in braces ("{@code {}}").  Adjacent
1309 >     * mappings are separated by the characters {@code ", "} (comma
1310 >     * and space).  Each key-value mapping is rendered as the key
1311 >     * followed by an equals sign ("{@code =}") followed by the
1312 >     * associated value.
1313 >     *
1314 >     * @return a string representation of this map
1315 >     */
1316 >    public String toString() {
1317 >        Node<K,V>[] t;
1318 >        int f = (t = table) == null ? 0 : t.length;
1319 >        Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1320 >        StringBuilder sb = new StringBuilder();
1321 >        sb.append('{');
1322 >        Node<K,V> p;
1323 >        if ((p = it.advance()) != null) {
1324 >            for (;;) {
1325 >                K k = p.key;
1326 >                V v = p.val;
1327 >                sb.append(k == this ? "(this Map)" : k);
1328 >                sb.append('=');
1329 >                sb.append(v == this ? "(this Map)" : v);
1330 >                if ((p = it.advance()) == null)
1331 >                    break;
1332 >                sb.append(',').append(' ');
1333 >            }
1334 >        }
1335 >        return sb.append('}').toString();
1336 >    }
1337 >
1338 >    /**
1339 >     * Compares the specified object with this map for equality.
1340 >     * Returns {@code true} if the given object is a map with the same
1341 >     * mappings as this map.  This operation may return misleading
1342 >     * results if either map is concurrently modified during execution
1343 >     * of this method.
1344 >     *
1345 >     * @param o object to be compared for equality with this map
1346 >     * @return {@code true} if the specified object is equal to this map
1347 >     */
1348 >    public boolean equals(Object o) {
1349 >        if (o != this) {
1350 >            if (!(o instanceof Map))
1351 >                return false;
1352 >            Map<?,?> m = (Map<?,?>) o;
1353 >            Node<K,V>[] t;
1354 >            int f = (t = table) == null ? 0 : t.length;
1355 >            Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1356 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1357 >                V val = p.val;
1358 >                Object v = m.get(p.key);
1359 >                if (v == null || (v != val && !v.equals(val)))
1360 >                    return false;
1361 >            }
1362 >            for (Map.Entry<?,?> e : m.entrySet()) {
1363 >                Object mk, mv, v;
1364 >                if ((mk = e.getKey()) == null ||
1365 >                    (mv = e.getValue()) == null ||
1366 >                    (v = get(mk)) == null ||
1367 >                    (mv != v && !mv.equals(v)))
1368 >                    return false;
1369 >            }
1370 >        }
1371 >        return true;
1372 >    }
1373 >
1374 >    /**
1375 >     * Stripped-down version of helper class used in previous version,
1376 >     * declared for the sake of serialization compatibility
1377 >     */
1378 >    static class Segment<K,V> extends ReentrantLock implements Serializable {
1379 >        private static final long serialVersionUID = 2249069246763182397L;
1380 >        final float loadFactor;
1381 >        Segment(float lf) { this.loadFactor = lf; }
1382 >    }
1383 >
1384 >    /**
1385 >     * Saves the state of the {@code ConcurrentHashMapV8} instance to a
1386 >     * stream (i.e., serializes it).
1387 >     * @param s the stream
1388 >     * @throws java.io.IOException if an I/O error occurs
1389 >     * @serialData
1390 >     * the key (Object) and value (Object)
1391 >     * for each key-value mapping, followed by a null pair.
1392 >     * The key-value mappings are emitted in no particular order.
1393 >     */
1394 >    private void writeObject(java.io.ObjectOutputStream s)
1395 >        throws java.io.IOException {
1396 >        // For serialization compatibility
1397 >        // Emulate segment calculation from previous version of this class
1398 >        int sshift = 0;
1399 >        int ssize = 1;
1400 >        while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1401 >            ++sshift;
1402 >            ssize <<= 1;
1403 >        }
1404 >        int segmentShift = 32 - sshift;
1405 >        int segmentMask = ssize - 1;
1406 >        @SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1407 >            new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1408 >        for (int i = 0; i < segments.length; ++i)
1409 >            segments[i] = new Segment<K,V>(LOAD_FACTOR);
1410 >        s.putFields().put("segments", segments);
1411 >        s.putFields().put("segmentShift", segmentShift);
1412 >        s.putFields().put("segmentMask", segmentMask);
1413 >        s.writeFields();
1414 >
1415 >        Node<K,V>[] t;
1416 >        if ((t = table) != null) {
1417 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1418 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1419 >                s.writeObject(p.key);
1420 >                s.writeObject(p.val);
1421 >            }
1422 >        }
1423 >        s.writeObject(null);
1424 >        s.writeObject(null);
1425 >        segments = null; // throw away
1426 >    }
1427 >
1428 >    /**
1429 >     * Reconstitutes the instance from a stream (that is, deserializes it).
1430 >     * @param s the stream
1431 >     * @throws ClassNotFoundException if the class of a serialized object
1432 >     *         could not be found
1433 >     * @throws java.io.IOException if an I/O error occurs
1434 >     */
1435 >    private void readObject(java.io.ObjectInputStream s)
1436 >        throws java.io.IOException, ClassNotFoundException {
1437 >        /*
1438 >         * To improve performance in typical cases, we create nodes
1439 >         * while reading, then place in table once size is known.
1440 >         * However, we must also validate uniqueness and deal with
1441 >         * overpopulated bins while doing so, which requires
1442 >         * specialized versions of putVal mechanics.
1443 >         */
1444 >        sizeCtl = -1; // force exclusion for table construction
1445 >        s.defaultReadObject();
1446 >        long size = 0L;
1447 >        Node<K,V> p = null;
1448 >        for (;;) {
1449 >            @SuppressWarnings("unchecked") K k = (K) s.readObject();
1450 >            @SuppressWarnings("unchecked") V v = (V) s.readObject();
1451 >            if (k != null && v != null) {
1452 >                p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1453 >                ++size;
1454 >            }
1455 >            else
1456 >                break;
1457 >        }
1458 >        if (size == 0L)
1459 >            sizeCtl = 0;
1460 >        else {
1461 >            int n;
1462 >            if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1463 >                n = MAXIMUM_CAPACITY;
1464 >            else {
1465 >                int sz = (int)size;
1466 >                n = tableSizeFor(sz + (sz >>> 1) + 1);
1467 >            }
1468 >            @SuppressWarnings("unchecked")
1469 >                Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1470 >            int mask = n - 1;
1471 >            long added = 0L;
1472 >            while (p != null) {
1473 >                boolean insertAtFront;
1474 >                Node<K,V> next = p.next, first;
1475 >                int h = p.hash, j = h & mask;
1476 >                if ((first = tabAt(tab, j)) == null)
1477 >                    insertAtFront = true;
1478 >                else {
1479 >                    K k = p.key;
1480 >                    if (first.hash < 0) {
1481 >                        TreeBin<K,V> t = (TreeBin<K,V>)first;
1482 >                        if (t.putTreeVal(h, k, p.val) == null)
1483 >                            ++added;
1484 >                        insertAtFront = false;
1485 >                    }
1486 >                    else {
1487 >                        int binCount = 0;
1488 >                        insertAtFront = true;
1489 >                        Node<K,V> q; K qk;
1490 >                        for (q = first; q != null; q = q.next) {
1491 >                            if (q.hash == h &&
1492 >                                ((qk = q.key) == k ||
1493 >                                 (qk != null && k.equals(qk)))) {
1494 >                                insertAtFront = false;
1495 >                                break;
1496 >                            }
1497 >                            ++binCount;
1498 >                        }
1499 >                        if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1500 >                            insertAtFront = false;
1501 >                            ++added;
1502 >                            p.next = first;
1503 >                            TreeNode<K,V> hd = null, tl = null;
1504 >                            for (q = p; q != null; q = q.next) {
1505 >                                TreeNode<K,V> t = new TreeNode<K,V>
1506 >                                    (q.hash, q.key, q.val, null, null);
1507 >                                if ((t.prev = tl) == null)
1508 >                                    hd = t;
1509 >                                else
1510 >                                    tl.next = t;
1511 >                                tl = t;
1512 >                            }
1513 >                            setTabAt(tab, j, new TreeBin<K,V>(hd));
1514 >                        }
1515 >                    }
1516 >                }
1517 >                if (insertAtFront) {
1518 >                    ++added;
1519 >                    p.next = first;
1520 >                    setTabAt(tab, j, p);
1521 >                }
1522 >                p = next;
1523 >            }
1524 >            table = tab;
1525 >            sizeCtl = n - (n >>> 2);
1526 >            baseCount = added;
1527 >        }
1528 >    }
1529 >
1530 >    // ConcurrentMap methods
1531 >
1532 >    /**
1533 >     * {@inheritDoc}
1534 >     *
1535 >     * @return the previous value associated with the specified key,
1536 >     *         or {@code null} if there was no mapping for the key
1537 >     * @throws NullPointerException if the specified key or value is null
1538 >     */
1539 >    public V putIfAbsent(K key, V value) {
1540 >        return putVal(key, value, true);
1541 >    }
1542 >
1543 >    /**
1544 >     * {@inheritDoc}
1545 >     *
1546 >     * @throws NullPointerException if the specified key is null
1547 >     */
1548 >    public boolean remove(Object key, Object value) {
1549 >        if (key == null)
1550 >            throw new NullPointerException();
1551 >        return value != null && replaceNode(key, null, value) != null;
1552 >    }
1553 >
1554 >    /**
1555 >     * {@inheritDoc}
1556 >     *
1557 >     * @throws NullPointerException if any of the arguments are null
1558 >     */
1559 >    public boolean replace(K key, V oldValue, V newValue) {
1560 >        if (key == null || oldValue == null || newValue == null)
1561              throw new NullPointerException();
1562 <        return (V)internalPut(key, value);
1562 >        return replaceNode(key, newValue, oldValue) != null;
1563      }
1564  
1565      /**
# Line 2735 | Line 1569 | public class ConcurrentHashMapV8<K, V>
1569       *         or {@code null} if there was no mapping for the key
1570       * @throws NullPointerException if the specified key or value is null
1571       */
1572 <    @SuppressWarnings("unchecked") public V putIfAbsent(K key, V value) {
1572 >    public V replace(K key, V value) {
1573          if (key == null || value == null)
1574              throw new NullPointerException();
1575 <        return (V)internalPutIfAbsent(key, value);
1575 >        return replaceNode(key, value, null);
1576      }
1577  
1578 +    // Overrides of JDK8+ Map extension method defaults
1579 +
1580      /**
1581 <     * Copies all of the mappings from the specified map to this one.
1582 <     * These mappings replace any mappings that this map had for any of the
1583 <     * keys currently in the specified map.
1581 >     * Returns the value to which the specified key is mapped, or the
1582 >     * given default value if this map contains no mapping for the
1583 >     * key.
1584       *
1585 <     * @param m mappings to be stored in this map
1585 >     * @param key the key whose associated value is to be returned
1586 >     * @param defaultValue the value to return if this map contains
1587 >     * no mapping for the given key
1588 >     * @return the mapping for the key, if present; else the default value
1589 >     * @throws NullPointerException if the specified key is null
1590       */
1591 <    public void putAll(Map<? extends K, ? extends V> m) {
1592 <        internalPutAll(m);
1591 >    public V getOrDefault(Object key, V defaultValue) {
1592 >        V v;
1593 >        return (v = get(key)) == null ? defaultValue : v;
1594 >    }
1595 >
1596 >    public void forEach(BiAction<? super K, ? super V> action) {
1597 >        if (action == null) throw new NullPointerException();
1598 >        Node<K,V>[] t;
1599 >        if ((t = table) != null) {
1600 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1601 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1602 >                action.apply(p.key, p.val);
1603 >            }
1604 >        }
1605 >    }
1606 >
1607 >    public void replaceAll(BiFun<? super K, ? super V, ? extends V> function) {
1608 >        if (function == null) throw new NullPointerException();
1609 >        Node<K,V>[] t;
1610 >        if ((t = table) != null) {
1611 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1612 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1613 >                V oldValue = p.val;
1614 >                for (K key = p.key;;) {
1615 >                    V newValue = function.apply(key, oldValue);
1616 >                    if (newValue == null)
1617 >                        throw new NullPointerException();
1618 >                    if (replaceNode(key, newValue, oldValue) != null ||
1619 >                        (oldValue = get(key)) == null)
1620 >                        break;
1621 >                }
1622 >            }
1623 >        }
1624      }
1625  
1626      /**
1627       * If the specified key is not already associated with a value,
1628 <     * computes its value using the given mappingFunction and enters
1629 <     * it into the map unless null.  This is equivalent to
1630 <     * <pre> {@code
1631 <     * if (map.containsKey(key))
1632 <     *   return map.get(key);
1633 <     * value = mappingFunction.apply(key);
1634 <     * if (value != null)
2764 <     *   map.put(key, value);
2765 <     * return value;}</pre>
2766 <     *
2767 <     * except that the action is performed atomically.  If the
2768 <     * function returns {@code null} no mapping is recorded. If the
2769 <     * function itself throws an (unchecked) exception, the exception
2770 <     * is rethrown to its caller, and no mapping is recorded.  Some
2771 <     * attempted update operations on this map by other threads may be
2772 <     * blocked while computation is in progress, so the computation
2773 <     * should be short and simple, and must not attempt to update any
2774 <     * other mappings of this Map. The most appropriate usage is to
2775 <     * construct a new object serving as an initial mapped value, or
2776 <     * memoized result, as in:
2777 <     *
2778 <     *  <pre> {@code
2779 <     * map.computeIfAbsent(key, new Fun<K, V>() {
2780 <     *   public V map(K k) { return new Value(f(k)); }});}</pre>
1628 >     * attempts to compute its value using the given mapping function
1629 >     * and enters it into this map unless {@code null}.  The entire
1630 >     * method invocation is performed atomically, so the function is
1631 >     * applied at most once per key.  Some attempted update operations
1632 >     * on this map by other threads may be blocked while computation
1633 >     * is in progress, so the computation should be short and simple,
1634 >     * and must not attempt to update any other mappings of this map.
1635       *
1636       * @param key key with which the specified value is to be associated
1637       * @param mappingFunction the function to compute a value
# Line 2791 | Line 1645 | public class ConcurrentHashMapV8<K, V>
1645       * @throws RuntimeException or Error if the mappingFunction does so,
1646       *         in which case the mapping is left unestablished
1647       */
1648 <    @SuppressWarnings("unchecked") public V computeIfAbsent
2795 <        (K key, Fun<? super K, ? extends V> mappingFunction) {
1648 >    public V computeIfAbsent(K key, Fun<? super K, ? extends V> mappingFunction) {
1649          if (key == null || mappingFunction == null)
1650              throw new NullPointerException();
1651 <        return (V)internalComputeIfAbsent(key, mappingFunction);
1651 >        int h = spread(key.hashCode());
1652 >        V val = null;
1653 >        int binCount = 0;
1654 >        for (Node<K,V>[] tab = table;;) {
1655 >            Node<K,V> f; int n, i, fh;
1656 >            if (tab == null || (n = tab.length) == 0)
1657 >                tab = initTable();
1658 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1659 >                Node<K,V> r = new ReservationNode<K,V>();
1660 >                synchronized (r) {
1661 >                    if (casTabAt(tab, i, null, r)) {
1662 >                        binCount = 1;
1663 >                        Node<K,V> node = null;
1664 >                        try {
1665 >                            if ((val = mappingFunction.apply(key)) != null)
1666 >                                node = new Node<K,V>(h, key, val, null);
1667 >                        } finally {
1668 >                            setTabAt(tab, i, node);
1669 >                        }
1670 >                    }
1671 >                }
1672 >                if (binCount != 0)
1673 >                    break;
1674 >            }
1675 >            else if ((fh = f.hash) == MOVED)
1676 >                tab = helpTransfer(tab, f);
1677 >            else {
1678 >                boolean added = false;
1679 >                synchronized (f) {
1680 >                    if (tabAt(tab, i) == f) {
1681 >                        if (fh >= 0) {
1682 >                            binCount = 1;
1683 >                            for (Node<K,V> e = f;; ++binCount) {
1684 >                                K ek; V ev;
1685 >                                if (e.hash == h &&
1686 >                                    ((ek = e.key) == key ||
1687 >                                     (ek != null && key.equals(ek)))) {
1688 >                                    val = e.val;
1689 >                                    break;
1690 >                                }
1691 >                                Node<K,V> pred = e;
1692 >                                if ((e = e.next) == null) {
1693 >                                    if ((val = mappingFunction.apply(key)) != null) {
1694 >                                        added = true;
1695 >                                        pred.next = new Node<K,V>(h, key, val, null);
1696 >                                    }
1697 >                                    break;
1698 >                                }
1699 >                            }
1700 >                        }
1701 >                        else if (f instanceof TreeBin) {
1702 >                            binCount = 2;
1703 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1704 >                            TreeNode<K,V> r, p;
1705 >                            if ((r = t.root) != null &&
1706 >                                (p = r.findTreeNode(h, key, null)) != null)
1707 >                                val = p.val;
1708 >                            else if ((val = mappingFunction.apply(key)) != null) {
1709 >                                added = true;
1710 >                                t.putTreeVal(h, key, val);
1711 >                            }
1712 >                        }
1713 >                    }
1714 >                }
1715 >                if (binCount != 0) {
1716 >                    if (binCount >= TREEIFY_THRESHOLD)
1717 >                        treeifyBin(tab, i);
1718 >                    if (!added)
1719 >                        return val;
1720 >                    break;
1721 >                }
1722 >            }
1723 >        }
1724 >        if (val != null)
1725 >            addCount(1L, binCount);
1726 >        return val;
1727      }
1728  
1729      /**
1730 <     * If the given key is present, computes a new mapping value given a key and
1731 <     * its current mapped value. This is equivalent to
1732 <     *  <pre> {@code
1733 <     *   if (map.containsKey(key)) {
1734 <     *     value = remappingFunction.apply(key, map.get(key));
1735 <     *     if (value != null)
1736 <     *       map.put(key, value);
2809 <     *     else
2810 <     *       map.remove(key);
2811 <     *   }
2812 <     * }</pre>
2813 <     *
2814 <     * except that the action is performed atomically.  If the
2815 <     * function returns {@code null}, the mapping is removed.  If the
2816 <     * function itself throws an (unchecked) exception, the exception
2817 <     * is rethrown to its caller, and the current mapping is left
2818 <     * unchanged.  Some attempted update operations on this map by
2819 <     * other threads may be blocked while computation is in progress,
2820 <     * so the computation should be short and simple, and must not
2821 <     * attempt to update any other mappings of this Map. For example,
2822 <     * to either create or append new messages to a value mapping:
1730 >     * If the value for the specified key is present, attempts to
1731 >     * compute a new mapping given the key and its current mapped
1732 >     * value.  The entire method invocation is performed atomically.
1733 >     * Some attempted update operations on this map by other threads
1734 >     * may be blocked while computation is in progress, so the
1735 >     * computation should be short and simple, and must not attempt to
1736 >     * update any other mappings of this map.
1737       *
1738 <     * @param key key with which the specified value is to be associated
1738 >     * @param key key with which a value may be associated
1739       * @param remappingFunction the function to compute a value
1740       * @return the new value associated with the specified key, or null if none
1741       * @throws NullPointerException if the specified key or remappingFunction
# Line 2832 | Line 1746 | public class ConcurrentHashMapV8<K, V>
1746       * @throws RuntimeException or Error if the remappingFunction does so,
1747       *         in which case the mapping is unchanged
1748       */
1749 <    @SuppressWarnings("unchecked") public V computeIfPresent
2836 <        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1749 >    public V computeIfPresent(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1750          if (key == null || remappingFunction == null)
1751              throw new NullPointerException();
1752 <        return (V)internalCompute(key, true, remappingFunction);
1752 >        int h = spread(key.hashCode());
1753 >        V val = null;
1754 >        int delta = 0;
1755 >        int binCount = 0;
1756 >        for (Node<K,V>[] tab = table;;) {
1757 >            Node<K,V> f; int n, i, fh;
1758 >            if (tab == null || (n = tab.length) == 0)
1759 >                tab = initTable();
1760 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1761 >                break;
1762 >            else if ((fh = f.hash) == MOVED)
1763 >                tab = helpTransfer(tab, f);
1764 >            else {
1765 >                synchronized (f) {
1766 >                    if (tabAt(tab, i) == f) {
1767 >                        if (fh >= 0) {
1768 >                            binCount = 1;
1769 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1770 >                                K ek;
1771 >                                if (e.hash == h &&
1772 >                                    ((ek = e.key) == key ||
1773 >                                     (ek != null && key.equals(ek)))) {
1774 >                                    val = remappingFunction.apply(key, e.val);
1775 >                                    if (val != null)
1776 >                                        e.val = val;
1777 >                                    else {
1778 >                                        delta = -1;
1779 >                                        Node<K,V> en = e.next;
1780 >                                        if (pred != null)
1781 >                                            pred.next = en;
1782 >                                        else
1783 >                                            setTabAt(tab, i, en);
1784 >                                    }
1785 >                                    break;
1786 >                                }
1787 >                                pred = e;
1788 >                                if ((e = e.next) == null)
1789 >                                    break;
1790 >                            }
1791 >                        }
1792 >                        else if (f instanceof TreeBin) {
1793 >                            binCount = 2;
1794 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1795 >                            TreeNode<K,V> r, p;
1796 >                            if ((r = t.root) != null &&
1797 >                                (p = r.findTreeNode(h, key, null)) != null) {
1798 >                                val = remappingFunction.apply(key, p.val);
1799 >                                if (val != null)
1800 >                                    p.val = val;
1801 >                                else {
1802 >                                    delta = -1;
1803 >                                    if (t.removeTreeNode(p))
1804 >                                        setTabAt(tab, i, untreeify(t.first));
1805 >                                }
1806 >                            }
1807 >                        }
1808 >                    }
1809 >                }
1810 >                if (binCount != 0)
1811 >                    break;
1812 >            }
1813 >        }
1814 >        if (delta != 0)
1815 >            addCount((long)delta, binCount);
1816 >        return val;
1817      }
1818  
1819      /**
1820 <     * Computes a new mapping value given a key and
1821 <     * its current mapped value (or {@code null} if there is no current
1822 <     * mapping). This is equivalent to
1823 <     *  <pre> {@code
1824 <     *   value = remappingFunction.apply(key, map.get(key));
1825 <     *   if (value != null)
1826 <     *     map.put(key, value);
2850 <     *   else
2851 <     *     map.remove(key);
2852 <     * }</pre>
2853 <     *
2854 <     * except that the action is performed atomically.  If the
2855 <     * function returns {@code null}, the mapping is removed.  If the
2856 <     * function itself throws an (unchecked) exception, the exception
2857 <     * is rethrown to its caller, and the current mapping is left
2858 <     * unchanged.  Some attempted update operations on this map by
2859 <     * other threads may be blocked while computation is in progress,
2860 <     * so the computation should be short and simple, and must not
2861 <     * attempt to update any other mappings of this Map. For example,
2862 <     * to either create or append new messages to a value mapping:
2863 <     *
2864 <     * <pre> {@code
2865 <     * Map<Key, String> map = ...;
2866 <     * final String msg = ...;
2867 <     * map.compute(key, new BiFun<Key, String, String>() {
2868 <     *   public String apply(Key k, String v) {
2869 <     *    return (v == null) ? msg : v + msg;});}}</pre>
1820 >     * Attempts to compute a mapping for the specified key and its
1821 >     * current mapped value (or {@code null} if there is no current
1822 >     * mapping). The entire method invocation is performed atomically.
1823 >     * Some attempted update operations on this map by other threads
1824 >     * may be blocked while computation is in progress, so the
1825 >     * computation should be short and simple, and must not attempt to
1826 >     * update any other mappings of this Map.
1827       *
1828       * @param key key with which the specified value is to be associated
1829       * @param remappingFunction the function to compute a value
# Line 2879 | Line 1836 | public class ConcurrentHashMapV8<K, V>
1836       * @throws RuntimeException or Error if the remappingFunction does so,
1837       *         in which case the mapping is unchanged
1838       */
1839 <    @SuppressWarnings("unchecked") public V compute
1840 <        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1839 >    public V compute(K key,
1840 >                     BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1841          if (key == null || remappingFunction == null)
1842              throw new NullPointerException();
1843 <        return (V)internalCompute(key, false, remappingFunction);
1843 >        int h = spread(key.hashCode());
1844 >        V val = null;
1845 >        int delta = 0;
1846 >        int binCount = 0;
1847 >        for (Node<K,V>[] tab = table;;) {
1848 >            Node<K,V> f; int n, i, fh;
1849 >            if (tab == null || (n = tab.length) == 0)
1850 >                tab = initTable();
1851 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1852 >                Node<K,V> r = new ReservationNode<K,V>();
1853 >                synchronized (r) {
1854 >                    if (casTabAt(tab, i, null, r)) {
1855 >                        binCount = 1;
1856 >                        Node<K,V> node = null;
1857 >                        try {
1858 >                            if ((val = remappingFunction.apply(key, null)) != null) {
1859 >                                delta = 1;
1860 >                                node = new Node<K,V>(h, key, val, null);
1861 >                            }
1862 >                        } finally {
1863 >                            setTabAt(tab, i, node);
1864 >                        }
1865 >                    }
1866 >                }
1867 >                if (binCount != 0)
1868 >                    break;
1869 >            }
1870 >            else if ((fh = f.hash) == MOVED)
1871 >                tab = helpTransfer(tab, f);
1872 >            else {
1873 >                synchronized (f) {
1874 >                    if (tabAt(tab, i) == f) {
1875 >                        if (fh >= 0) {
1876 >                            binCount = 1;
1877 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1878 >                                K ek;
1879 >                                if (e.hash == h &&
1880 >                                    ((ek = e.key) == key ||
1881 >                                     (ek != null && key.equals(ek)))) {
1882 >                                    val = remappingFunction.apply(key, e.val);
1883 >                                    if (val != null)
1884 >                                        e.val = val;
1885 >                                    else {
1886 >                                        delta = -1;
1887 >                                        Node<K,V> en = e.next;
1888 >                                        if (pred != null)
1889 >                                            pred.next = en;
1890 >                                        else
1891 >                                            setTabAt(tab, i, en);
1892 >                                    }
1893 >                                    break;
1894 >                                }
1895 >                                pred = e;
1896 >                                if ((e = e.next) == null) {
1897 >                                    val = remappingFunction.apply(key, null);
1898 >                                    if (val != null) {
1899 >                                        delta = 1;
1900 >                                        pred.next =
1901 >                                            new Node<K,V>(h, key, val, null);
1902 >                                    }
1903 >                                    break;
1904 >                                }
1905 >                            }
1906 >                        }
1907 >                        else if (f instanceof TreeBin) {
1908 >                            binCount = 1;
1909 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1910 >                            TreeNode<K,V> r, p;
1911 >                            if ((r = t.root) != null)
1912 >                                p = r.findTreeNode(h, key, null);
1913 >                            else
1914 >                                p = null;
1915 >                            V pv = (p == null) ? null : p.val;
1916 >                            val = remappingFunction.apply(key, pv);
1917 >                            if (val != null) {
1918 >                                if (p != null)
1919 >                                    p.val = val;
1920 >                                else {
1921 >                                    delta = 1;
1922 >                                    t.putTreeVal(h, key, val);
1923 >                                }
1924 >                            }
1925 >                            else if (p != null) {
1926 >                                delta = -1;
1927 >                                if (t.removeTreeNode(p))
1928 >                                    setTabAt(tab, i, untreeify(t.first));
1929 >                            }
1930 >                        }
1931 >                    }
1932 >                }
1933 >                if (binCount != 0) {
1934 >                    if (binCount >= TREEIFY_THRESHOLD)
1935 >                        treeifyBin(tab, i);
1936 >                    break;
1937 >                }
1938 >            }
1939 >        }
1940 >        if (delta != 0)
1941 >            addCount((long)delta, binCount);
1942 >        return val;
1943      }
1944  
1945      /**
1946 <     * If the specified key is not already associated
1947 <     * with a value, associate it with the given value.
1948 <     * Otherwise, replace the value with the results of
1949 <     * the given remapping function. This is equivalent to:
1950 <     *  <pre> {@code
1951 <     *   if (!map.containsKey(key))
1952 <     *     map.put(value);
1953 <     *   else {
1954 <     *     newValue = remappingFunction.apply(map.get(key), value);
1955 <     *     if (value != null)
1956 <     *       map.put(key, value);
1957 <     *     else
1958 <     *       map.remove(key);
1959 <     *   }
1960 <     * }</pre>
1961 <     * except that the action is performed atomically.  If the
1962 <     * function returns {@code null}, the mapping is removed.  If the
1963 <     * function itself throws an (unchecked) exception, the exception
2908 <     * is rethrown to its caller, and the current mapping is left
2909 <     * unchanged.  Some attempted update operations on this map by
2910 <     * other threads may be blocked while computation is in progress,
2911 <     * so the computation should be short and simple, and must not
2912 <     * attempt to update any other mappings of this Map.
1946 >     * If the specified key is not already associated with a
1947 >     * (non-null) value, associates it with the given value.
1948 >     * Otherwise, replaces the value with the results of the given
1949 >     * remapping function, or removes if {@code null}. The entire
1950 >     * method invocation is performed atomically.  Some attempted
1951 >     * update operations on this map by other threads may be blocked
1952 >     * while computation is in progress, so the computation should be
1953 >     * short and simple, and must not attempt to update any other
1954 >     * mappings of this Map.
1955 >     *
1956 >     * @param key key with which the specified value is to be associated
1957 >     * @param value the value to use if absent
1958 >     * @param remappingFunction the function to recompute a value if present
1959 >     * @return the new value associated with the specified key, or null if none
1960 >     * @throws NullPointerException if the specified key or the
1961 >     *         remappingFunction is null
1962 >     * @throws RuntimeException or Error if the remappingFunction does so,
1963 >     *         in which case the mapping is unchanged
1964       */
1965 <    @SuppressWarnings("unchecked") public V merge
2915 <        (K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
1965 >    public V merge(K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
1966          if (key == null || value == null || remappingFunction == null)
1967              throw new NullPointerException();
1968 <        return (V)internalMerge(key, value, remappingFunction);
1968 >        int h = spread(key.hashCode());
1969 >        V val = null;
1970 >        int delta = 0;
1971 >        int binCount = 0;
1972 >        for (Node<K,V>[] tab = table;;) {
1973 >            Node<K,V> f; int n, i, fh;
1974 >            if (tab == null || (n = tab.length) == 0)
1975 >                tab = initTable();
1976 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1977 >                if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1978 >                    delta = 1;
1979 >                    val = value;
1980 >                    break;
1981 >                }
1982 >            }
1983 >            else if ((fh = f.hash) == MOVED)
1984 >                tab = helpTransfer(tab, f);
1985 >            else {
1986 >                synchronized (f) {
1987 >                    if (tabAt(tab, i) == f) {
1988 >                        if (fh >= 0) {
1989 >                            binCount = 1;
1990 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1991 >                                K ek;
1992 >                                if (e.hash == h &&
1993 >                                    ((ek = e.key) == key ||
1994 >                                     (ek != null && key.equals(ek)))) {
1995 >                                    val = remappingFunction.apply(e.val, value);
1996 >                                    if (val != null)
1997 >                                        e.val = val;
1998 >                                    else {
1999 >                                        delta = -1;
2000 >                                        Node<K,V> en = e.next;
2001 >                                        if (pred != null)
2002 >                                            pred.next = en;
2003 >                                        else
2004 >                                            setTabAt(tab, i, en);
2005 >                                    }
2006 >                                    break;
2007 >                                }
2008 >                                pred = e;
2009 >                                if ((e = e.next) == null) {
2010 >                                    delta = 1;
2011 >                                    val = value;
2012 >                                    pred.next =
2013 >                                        new Node<K,V>(h, key, val, null);
2014 >                                    break;
2015 >                                }
2016 >                            }
2017 >                        }
2018 >                        else if (f instanceof TreeBin) {
2019 >                            binCount = 2;
2020 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
2021 >                            TreeNode<K,V> r = t.root;
2022 >                            TreeNode<K,V> p = (r == null) ? null :
2023 >                                r.findTreeNode(h, key, null);
2024 >                            val = (p == null) ? value :
2025 >                                remappingFunction.apply(p.val, value);
2026 >                            if (val != null) {
2027 >                                if (p != null)
2028 >                                    p.val = val;
2029 >                                else {
2030 >                                    delta = 1;
2031 >                                    t.putTreeVal(h, key, val);
2032 >                                }
2033 >                            }
2034 >                            else if (p != null) {
2035 >                                delta = -1;
2036 >                                if (t.removeTreeNode(p))
2037 >                                    setTabAt(tab, i, untreeify(t.first));
2038 >                            }
2039 >                        }
2040 >                    }
2041 >                }
2042 >                if (binCount != 0) {
2043 >                    if (binCount >= TREEIFY_THRESHOLD)
2044 >                        treeifyBin(tab, i);
2045 >                    break;
2046 >                }
2047 >            }
2048 >        }
2049 >        if (delta != 0)
2050 >            addCount((long)delta, binCount);
2051 >        return val;
2052      }
2053  
2054 +    // Hashtable legacy methods
2055 +
2056      /**
2057 <     * Removes the key (and its corresponding value) from this map.
2058 <     * This method does nothing if the key is not in the map.
2057 >     * Legacy method testing if some key maps into the specified value
2058 >     * in this table.  This method is identical in functionality to
2059 >     * {@link #containsValue(Object)}, and exists solely to ensure
2060 >     * full compatibility with class {@link java.util.Hashtable},
2061 >     * which supported this method prior to introduction of the
2062 >     * Java Collections framework.
2063       *
2064 <     * @param  key the key that needs to be removed
2065 <     * @return the previous value associated with {@code key}, or
2066 <     *         {@code null} if there was no mapping for {@code key}
2067 <     * @throws NullPointerException if the specified key is null
2064 >     * @param  value a value to search for
2065 >     * @return {@code true} if and only if some key maps to the
2066 >     *         {@code value} argument in this table as
2067 >     *         determined by the {@code equals} method;
2068 >     *         {@code false} otherwise
2069 >     * @throws NullPointerException if the specified value is null
2070       */
2071 <    @SuppressWarnings("unchecked") public V remove(Object key) {
2072 <        if (key == null)
2932 <            throw new NullPointerException();
2933 <        return (V)internalReplace(key, null, null);
2071 >    @Deprecated public boolean contains(Object value) {
2072 >        return containsValue(value);
2073      }
2074  
2075      /**
2076 <     * {@inheritDoc}
2076 >     * Returns an enumeration of the keys in this table.
2077       *
2078 <     * @throws NullPointerException if the specified key is null
2078 >     * @return an enumeration of the keys in this table
2079 >     * @see #keySet()
2080       */
2081 <    public boolean remove(Object key, Object value) {
2082 <        if (key == null)
2083 <            throw new NullPointerException();
2084 <        if (value == null)
2945 <            return false;
2946 <        return internalReplace(key, null, value) != null;
2081 >    public Enumeration<K> keys() {
2082 >        Node<K,V>[] t;
2083 >        int f = (t = table) == null ? 0 : t.length;
2084 >        return new KeyIterator<K,V>(t, f, 0, f, this);
2085      }
2086  
2087      /**
2088 <     * {@inheritDoc}
2088 >     * Returns an enumeration of the values in this table.
2089       *
2090 <     * @throws NullPointerException if any of the arguments are null
2090 >     * @return an enumeration of the values in this table
2091 >     * @see #values()
2092       */
2093 <    public boolean replace(K key, V oldValue, V newValue) {
2094 <        if (key == null || oldValue == null || newValue == null)
2095 <            throw new NullPointerException();
2096 <        return internalReplace(key, newValue, oldValue) != null;
2093 >    public Enumeration<V> elements() {
2094 >        Node<K,V>[] t;
2095 >        int f = (t = table) == null ? 0 : t.length;
2096 >        return new ValueIterator<K,V>(t, f, 0, f, this);
2097      }
2098  
2099 +    // ConcurrentHashMapV8-only methods
2100 +
2101      /**
2102 <     * {@inheritDoc}
2102 >     * Returns the number of mappings. This method should be used
2103 >     * instead of {@link #size} because a ConcurrentHashMapV8 may
2104 >     * contain more mappings than can be represented as an int. The
2105 >     * value returned is an estimate; the actual count may differ if
2106 >     * there are concurrent insertions or removals.
2107       *
2108 <     * @return the previous value associated with the specified key,
2109 <     *         or {@code null} if there was no mapping for the key
2965 <     * @throws NullPointerException if the specified key or value is null
2108 >     * @return the number of mappings
2109 >     * @since 1.8
2110       */
2111 <    @SuppressWarnings("unchecked") public V replace(K key, V value) {
2112 <        if (key == null || value == null)
2113 <            throw new NullPointerException();
2970 <        return (V)internalReplace(key, value, null);
2111 >    public long mappingCount() {
2112 >        long n = sumCount();
2113 >        return (n < 0L) ? 0L : n; // ignore transient negative values
2114      }
2115  
2116      /**
2117 <     * Removes all of the mappings from this map.
2117 >     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2118 >     * from the given type to {@code Boolean.TRUE}.
2119 >     *
2120 >     * @return the new set
2121 >     * @since 1.8
2122       */
2123 <    public void clear() {
2124 <        internalClear();
2123 >    public static <K> KeySetView<K,Boolean> newKeySet() {
2124 >        return new KeySetView<K,Boolean>
2125 >            (new ConcurrentHashMapV8<K,Boolean>(), Boolean.TRUE);
2126      }
2127  
2128      /**
2129 <     * Returns a {@link Set} view of the keys contained in this map.
2130 <     * The set is backed by the map, so changes to the map are
2983 <     * reflected in the set, and vice-versa.
2129 >     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2130 >     * from the given type to {@code Boolean.TRUE}.
2131       *
2132 <     * @return the set view
2132 >     * @param initialCapacity The implementation performs internal
2133 >     * sizing to accommodate this many elements.
2134 >     * @return the new set
2135 >     * @throws IllegalArgumentException if the initial capacity of
2136 >     * elements is negative
2137 >     * @since 1.8
2138       */
2139 <    public KeySetView<K,V> keySet() {
2140 <        KeySetView<K,V> ks = keySet;
2141 <        return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2139 >    public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2140 >        return new KeySetView<K,Boolean>
2141 >            (new ConcurrentHashMapV8<K,Boolean>(initialCapacity), Boolean.TRUE);
2142      }
2143  
2144      /**
2145       * Returns a {@link Set} view of the keys in this map, using the
2146       * given common mapped value for any additions (i.e., {@link
2147 <     * Collection#add} and {@link Collection#addAll}). This is of
2148 <     * course only appropriate if it is acceptable to use the same
2149 <     * value for all additions from this view.
2147 >     * Collection#add} and {@link Collection#addAll(Collection)}).
2148 >     * This is of course only appropriate if it is acceptable to use
2149 >     * the same value for all additions from this view.
2150       *
2151 <     * @param mappedValue the mapped value to use for any
3000 <     * additions.
2151 >     * @param mappedValue the mapped value to use for any additions
2152       * @return the set view
2153       * @throws NullPointerException if the mappedValue is null
2154       */
# Line 3007 | Line 2158 | public class ConcurrentHashMapV8<K, V>
2158          return new KeySetView<K,V>(this, mappedValue);
2159      }
2160  
2161 +    /* ---------------- Special Nodes -------------- */
2162 +
2163      /**
2164 <     * Returns a {@link Collection} view of the values contained in this map.
3012 <     * The collection is backed by the map, so changes to the map are
3013 <     * reflected in the collection, and vice-versa.
2164 >     * A node inserted at head of bins during transfer operations.
2165       */
2166 <    public ValuesView<K,V> values() {
2167 <        ValuesView<K,V> vs = values;
2168 <        return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2166 >    static final class ForwardingNode<K,V> extends Node<K,V> {
2167 >        final Node<K,V>[] nextTable;
2168 >        ForwardingNode(Node<K,V>[] tab) {
2169 >            super(MOVED, null, null, null);
2170 >            this.nextTable = tab;
2171 >        }
2172 >
2173 >        Node<K,V> find(int h, Object k) {
2174 >            // loop to avoid arbitrarily deep recursion on forwarding nodes
2175 >            outer: for (Node<K,V>[] tab = nextTable;;) {
2176 >                Node<K,V> e; int n;
2177 >                if (k == null || tab == null || (n = tab.length) == 0 ||
2178 >                    (e = tabAt(tab, (n - 1) & h)) == null)
2179 >                    return null;
2180 >                for (;;) {
2181 >                    int eh; K ek;
2182 >                    if ((eh = e.hash) == h &&
2183 >                        ((ek = e.key) == k || (ek != null && k.equals(ek))))
2184 >                        return e;
2185 >                    if (eh < 0) {
2186 >                        if (e instanceof ForwardingNode) {
2187 >                            tab = ((ForwardingNode<K,V>)e).nextTable;
2188 >                            continue outer;
2189 >                        }
2190 >                        else
2191 >                            return e.find(h, k);
2192 >                    }
2193 >                    if ((e = e.next) == null)
2194 >                        return null;
2195 >                }
2196 >            }
2197 >        }
2198      }
2199  
2200      /**
2201 <     * Returns a {@link Set} view of the mappings contained in this map.
3022 <     * The set is backed by the map, so changes to the map are
3023 <     * reflected in the set, and vice-versa.  The set supports element
3024 <     * removal, which removes the corresponding mapping from the map,
3025 <     * via the {@code Iterator.remove}, {@code Set.remove},
3026 <     * {@code removeAll}, {@code retainAll}, and {@code clear}
3027 <     * operations.  It does not support the {@code add} or
3028 <     * {@code addAll} operations.
3029 <     *
3030 <     * <p>The view's {@code iterator} is a "weakly consistent" iterator
3031 <     * that will never throw {@link ConcurrentModificationException},
3032 <     * and guarantees to traverse elements as they existed upon
3033 <     * construction of the iterator, and may (but is not guaranteed to)
3034 <     * reflect any modifications subsequent to construction.
2201 >     * A place-holder node used in computeIfAbsent and compute
2202       */
2203 <    public Set<Map.Entry<K,V>> entrySet() {
2204 <        EntrySetView<K,V> es = entrySet;
2205 <        return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2203 >    static final class ReservationNode<K,V> extends Node<K,V> {
2204 >        ReservationNode() {
2205 >            super(RESERVED, null, null, null);
2206 >        }
2207 >
2208 >        Node<K,V> find(int h, Object k) {
2209 >            return null;
2210 >        }
2211      }
2212  
2213 +    /* ---------------- Table Initialization and Resizing -------------- */
2214 +
2215      /**
2216 <     * Returns an enumeration of the keys in this table.
2217 <     *
3044 <     * @return an enumeration of the keys in this table
3045 <     * @see #keySet()
2216 >     * Returns the stamp bits for resizing a table of size n.
2217 >     * Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2218       */
2219 <    public Enumeration<K> keys() {
2220 <        return new KeyIterator<K,V>(this);
2219 >    static final int resizeStamp(int n) {
2220 >        return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2221      }
2222  
2223      /**
2224 <     * Returns an enumeration of the values in this table.
3053 <     *
3054 <     * @return an enumeration of the values in this table
3055 <     * @see #values()
2224 >     * Initializes table, using the size recorded in sizeCtl.
2225       */
2226 <    public Enumeration<V> elements() {
2227 <        return new ValueIterator<K,V>(this);
2226 >    private final Node<K,V>[] initTable() {
2227 >        Node<K,V>[] tab; int sc;
2228 >        while ((tab = table) == null || tab.length == 0) {
2229 >            if ((sc = sizeCtl) < 0)
2230 >                Thread.yield(); // lost initialization race; just spin
2231 >            else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2232 >                try {
2233 >                    if ((tab = table) == null || tab.length == 0) {
2234 >                        int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2235 >                        @SuppressWarnings("unchecked")
2236 >                        Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2237 >                        table = tab = nt;
2238 >                        sc = n - (n >>> 2);
2239 >                    }
2240 >                } finally {
2241 >                    sizeCtl = sc;
2242 >                }
2243 >                break;
2244 >            }
2245 >        }
2246 >        return tab;
2247      }
2248  
2249      /**
2250 <     * Returns a partitionable iterator of the keys in this map.
2251 <     *
2252 <     * @return a partitionable iterator of the keys in this map
2250 >     * Adds to count, and if table is too small and not already
2251 >     * resizing, initiates transfer. If already resizing, helps
2252 >     * perform transfer if work is available.  Rechecks occupancy
2253 >     * after a transfer to see if another resize is already needed
2254 >     * because resizings are lagging additions.
2255 >     *
2256 >     * @param x the count to add
2257 >     * @param check if <0, don't check resize, if <= 1 only check if uncontended
2258 >     */
2259 >    private final void addCount(long x, int check) {
2260 >        CounterCell[] as; long b, s;
2261 >        if ((as = counterCells) != null ||
2262 >            !U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2263 >            CounterHashCode hc; CounterCell a; long v; int m;
2264 >            boolean uncontended = true;
2265 >            if ((hc = threadCounterHashCode.get()) == null ||
2266 >                as == null || (m = as.length - 1) < 0 ||
2267 >                (a = as[m & hc.code]) == null ||
2268 >                !(uncontended =
2269 >                  U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2270 >                fullAddCount(x, hc, uncontended);
2271 >                return;
2272 >            }
2273 >            if (check <= 1)
2274 >                return;
2275 >            s = sumCount();
2276 >        }
2277 >        if (check >= 0) {
2278 >            Node<K,V>[] tab, nt; int n, sc;
2279 >            while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2280 >                   (n = tab.length) < MAXIMUM_CAPACITY) {
2281 >                int rs = resizeStamp(n);
2282 >                if (sc < 0) {
2283 >                    if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2284 >                        sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2285 >                        transferIndex <= 0)
2286 >                        break;
2287 >                    if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2288 >                        transfer(tab, nt);
2289 >                }
2290 >                else if (U.compareAndSwapInt(this, SIZECTL, sc,
2291 >                                             (rs << RESIZE_STAMP_SHIFT) + 2))
2292 >                    transfer(tab, null);
2293 >                s = sumCount();
2294 >            }
2295 >        }
2296 >    }
2297 >
2298 >    /**
2299 >     * Helps transfer if a resize is in progress.
2300       */
2301 <    public Spliterator<K> keySpliterator() {
2302 <        return new KeyIterator<K,V>(this);
2301 >    final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2302 >        Node<K,V>[] nextTab; int sc;
2303 >        if (tab != null && (f instanceof ForwardingNode) &&
2304 >            (nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2305 >            int rs = resizeStamp(tab.length);
2306 >            while (nextTab == nextTable && table == tab &&
2307 >                   (sc = sizeCtl) < 0) {
2308 >                if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2309 >                    sc == rs + MAX_RESIZERS || transferIndex <= 0)
2310 >                    break;
2311 >                if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2312 >                    transfer(tab, nextTab);
2313 >                    break;
2314 >                }
2315 >            }
2316 >            return nextTab;
2317 >        }
2318 >        return table;
2319      }
2320  
2321      /**
2322 <     * Returns a partitionable iterator of the values in this map.
2322 >     * Tries to presize table to accommodate the given number of elements.
2323       *
2324 <     * @return a partitionable iterator of the values in this map
2324 >     * @param size number of elements (doesn't need to be perfectly accurate)
2325       */
2326 <    public Spliterator<V> valueSpliterator() {
2327 <        return new ValueIterator<K,V>(this);
2326 >    private final void tryPresize(int size) {
2327 >        int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2328 >            tableSizeFor(size + (size >>> 1) + 1);
2329 >        int sc;
2330 >        while ((sc = sizeCtl) >= 0) {
2331 >            Node<K,V>[] tab = table; int n;
2332 >            if (tab == null || (n = tab.length) == 0) {
2333 >                n = (sc > c) ? sc : c;
2334 >                if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2335 >                    try {
2336 >                        if (table == tab) {
2337 >                            @SuppressWarnings("unchecked")
2338 >                            Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2339 >                            table = nt;
2340 >                            sc = n - (n >>> 2);
2341 >                        }
2342 >                    } finally {
2343 >                        sizeCtl = sc;
2344 >                    }
2345 >                }
2346 >            }
2347 >            else if (c <= sc || n >= MAXIMUM_CAPACITY)
2348 >                break;
2349 >            else if (tab == table) {
2350 >                int rs = resizeStamp(n);
2351 >                if (sc < 0) {
2352 >                    Node<K,V>[] nt;
2353 >                    if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2354 >                        sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2355 >                        transferIndex <= 0)
2356 >                        break;
2357 >                    if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2358 >                        transfer(tab, nt);
2359 >                }
2360 >                else if (U.compareAndSwapInt(this, SIZECTL, sc,
2361 >                                             (rs << RESIZE_STAMP_SHIFT) + 2))
2362 >                    transfer(tab, null);
2363 >            }
2364 >        }
2365      }
2366  
2367      /**
2368 <     * Returns a partitionable iterator of the entries in this map.
2369 <     *
3082 <     * @return a partitionable iterator of the entries in this map
2368 >     * Moves and/or copies the nodes in each bin to new table. See
2369 >     * above for explanation.
2370       */
2371 <    public Spliterator<Map.Entry<K,V>> entrySpliterator() {
2372 <        return new EntryIterator<K,V>(this);
2371 >    private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2372 >        int n = tab.length, stride;
2373 >        if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2374 >            stride = MIN_TRANSFER_STRIDE; // subdivide range
2375 >        if (nextTab == null) {            // initiating
2376 >            try {
2377 >                @SuppressWarnings("unchecked")
2378 >                Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2379 >                nextTab = nt;
2380 >            } catch (Throwable ex) {      // try to cope with OOME
2381 >                sizeCtl = Integer.MAX_VALUE;
2382 >                return;
2383 >            }
2384 >            nextTable = nextTab;
2385 >            transferIndex = n;
2386 >        }
2387 >        int nextn = nextTab.length;
2388 >        ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2389 >        boolean advance = true;
2390 >        boolean finishing = false; // to ensure sweep before committing nextTab
2391 >        for (int i = 0, bound = 0;;) {
2392 >            Node<K,V> f; int fh;
2393 >            while (advance) {
2394 >                int nextIndex, nextBound;
2395 >                if (--i >= bound || finishing)
2396 >                    advance = false;
2397 >                else if ((nextIndex = transferIndex) <= 0) {
2398 >                    i = -1;
2399 >                    advance = false;
2400 >                }
2401 >                else if (U.compareAndSwapInt
2402 >                         (this, TRANSFERINDEX, nextIndex,
2403 >                          nextBound = (nextIndex > stride ?
2404 >                                       nextIndex - stride : 0))) {
2405 >                    bound = nextBound;
2406 >                    i = nextIndex - 1;
2407 >                    advance = false;
2408 >                }
2409 >            }
2410 >            if (i < 0 || i >= n || i + n >= nextn) {
2411 >                int sc;
2412 >                if (finishing) {
2413 >                    nextTable = null;
2414 >                    table = nextTab;
2415 >                    sizeCtl = (n << 1) - (n >>> 1);
2416 >                    return;
2417 >                }
2418 >                if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2419 >                    if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2420 >                        return;
2421 >                    finishing = advance = true;
2422 >                    i = n; // recheck before commit
2423 >                }
2424 >            }
2425 >            else if ((f = tabAt(tab, i)) == null)
2426 >                advance = casTabAt(tab, i, null, fwd);
2427 >            else if ((fh = f.hash) == MOVED)
2428 >                advance = true; // already processed
2429 >            else {
2430 >                synchronized (f) {
2431 >                    if (tabAt(tab, i) == f) {
2432 >                        Node<K,V> ln, hn;
2433 >                        if (fh >= 0) {
2434 >                            int runBit = fh & n;
2435 >                            Node<K,V> lastRun = f;
2436 >                            for (Node<K,V> p = f.next; p != null; p = p.next) {
2437 >                                int b = p.hash & n;
2438 >                                if (b != runBit) {
2439 >                                    runBit = b;
2440 >                                    lastRun = p;
2441 >                                }
2442 >                            }
2443 >                            if (runBit == 0) {
2444 >                                ln = lastRun;
2445 >                                hn = null;
2446 >                            }
2447 >                            else {
2448 >                                hn = lastRun;
2449 >                                ln = null;
2450 >                            }
2451 >                            for (Node<K,V> p = f; p != lastRun; p = p.next) {
2452 >                                int ph = p.hash; K pk = p.key; V pv = p.val;
2453 >                                if ((ph & n) == 0)
2454 >                                    ln = new Node<K,V>(ph, pk, pv, ln);
2455 >                                else
2456 >                                    hn = new Node<K,V>(ph, pk, pv, hn);
2457 >                            }
2458 >                            setTabAt(nextTab, i, ln);
2459 >                            setTabAt(nextTab, i + n, hn);
2460 >                            setTabAt(tab, i, fwd);
2461 >                            advance = true;
2462 >                        }
2463 >                        else if (f instanceof TreeBin) {
2464 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
2465 >                            TreeNode<K,V> lo = null, loTail = null;
2466 >                            TreeNode<K,V> hi = null, hiTail = null;
2467 >                            int lc = 0, hc = 0;
2468 >                            for (Node<K,V> e = t.first; e != null; e = e.next) {
2469 >                                int h = e.hash;
2470 >                                TreeNode<K,V> p = new TreeNode<K,V>
2471 >                                    (h, e.key, e.val, null, null);
2472 >                                if ((h & n) == 0) {
2473 >                                    if ((p.prev = loTail) == null)
2474 >                                        lo = p;
2475 >                                    else
2476 >                                        loTail.next = p;
2477 >                                    loTail = p;
2478 >                                    ++lc;
2479 >                                }
2480 >                                else {
2481 >                                    if ((p.prev = hiTail) == null)
2482 >                                        hi = p;
2483 >                                    else
2484 >                                        hiTail.next = p;
2485 >                                    hiTail = p;
2486 >                                    ++hc;
2487 >                                }
2488 >                            }
2489 >                            ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2490 >                                (hc != 0) ? new TreeBin<K,V>(lo) : t;
2491 >                            hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2492 >                                (lc != 0) ? new TreeBin<K,V>(hi) : t;
2493 >                            setTabAt(nextTab, i, ln);
2494 >                            setTabAt(nextTab, i + n, hn);
2495 >                            setTabAt(tab, i, fwd);
2496 >                            advance = true;
2497 >                        }
2498 >                    }
2499 >                }
2500 >            }
2501 >        }
2502      }
2503  
2504 +    /* ---------------- Conversion from/to TreeBins -------------- */
2505 +
2506      /**
2507 <     * Returns the hash code value for this {@link Map}, i.e.,
2508 <     * the sum of, for each key-value pair in the map,
3091 <     * {@code key.hashCode() ^ value.hashCode()}.
3092 <     *
3093 <     * @return the hash code value for this map
2507 >     * Replaces all linked nodes in bin at given index unless table is
2508 >     * too small, in which case resizes instead.
2509       */
2510 <    public int hashCode() {
2511 <        int h = 0;
2512 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2513 <        Object v;
2514 <        while ((v = it.advance()) != null) {
2515 <            h += it.nextKey.hashCode() ^ v.hashCode();
2510 >    private final void treeifyBin(Node<K,V>[] tab, int index) {
2511 >        Node<K,V> b; int n, sc;
2512 >        if (tab != null) {
2513 >            if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2514 >                tryPresize(n << 1);
2515 >            else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2516 >                synchronized (b) {
2517 >                    if (tabAt(tab, index) == b) {
2518 >                        TreeNode<K,V> hd = null, tl = null;
2519 >                        for (Node<K,V> e = b; e != null; e = e.next) {
2520 >                            TreeNode<K,V> p =
2521 >                                new TreeNode<K,V>(e.hash, e.key, e.val,
2522 >                                                  null, null);
2523 >                            if ((p.prev = tl) == null)
2524 >                                hd = p;
2525 >                            else
2526 >                                tl.next = p;
2527 >                            tl = p;
2528 >                        }
2529 >                        setTabAt(tab, index, new TreeBin<K,V>(hd));
2530 >                    }
2531 >                }
2532 >            }
2533          }
3102        return h;
2534      }
2535  
2536      /**
2537 <     * Returns a string representation of this map.  The string
3107 <     * representation consists of a list of key-value mappings (in no
3108 <     * particular order) enclosed in braces ("{@code {}}").  Adjacent
3109 <     * mappings are separated by the characters {@code ", "} (comma
3110 <     * and space).  Each key-value mapping is rendered as the key
3111 <     * followed by an equals sign ("{@code =}") followed by the
3112 <     * associated value.
3113 <     *
3114 <     * @return a string representation of this map
2537 >     * Returns a list on non-TreeNodes replacing those in given list.
2538       */
2539 <    public String toString() {
2540 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2541 <        StringBuilder sb = new StringBuilder();
2542 <        sb.append('{');
2543 <        Object v;
2544 <        if ((v = it.advance()) != null) {
2545 <            for (;;) {
2546 <                Object k = it.nextKey;
2547 <                sb.append(k == this ? "(this Map)" : k);
2548 <                sb.append('=');
2549 <                sb.append(v == this ? "(this Map)" : v);
2550 <                if ((v = it.advance()) == null)
2539 >    static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2540 >        Node<K,V> hd = null, tl = null;
2541 >        for (Node<K,V> q = b; q != null; q = q.next) {
2542 >            Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2543 >            if (tl == null)
2544 >                hd = p;
2545 >            else
2546 >                tl.next = p;
2547 >            tl = p;
2548 >        }
2549 >        return hd;
2550 >    }
2551 >
2552 >    /* ---------------- TreeNodes -------------- */
2553 >
2554 >    /**
2555 >     * Nodes for use in TreeBins
2556 >     */
2557 >    static final class TreeNode<K,V> extends Node<K,V> {
2558 >        TreeNode<K,V> parent;  // red-black tree links
2559 >        TreeNode<K,V> left;
2560 >        TreeNode<K,V> right;
2561 >        TreeNode<K,V> prev;    // needed to unlink next upon deletion
2562 >        boolean red;
2563 >
2564 >        TreeNode(int hash, K key, V val, Node<K,V> next,
2565 >                 TreeNode<K,V> parent) {
2566 >            super(hash, key, val, next);
2567 >            this.parent = parent;
2568 >        }
2569 >
2570 >        Node<K,V> find(int h, Object k) {
2571 >            return findTreeNode(h, k, null);
2572 >        }
2573 >
2574 >        /**
2575 >         * Returns the TreeNode (or null if not found) for the given key
2576 >         * starting at given root.
2577 >         */
2578 >        final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2579 >            if (k != null) {
2580 >                TreeNode<K,V> p = this;
2581 >                do {
2582 >                    int ph, dir; K pk; TreeNode<K,V> q;
2583 >                    TreeNode<K,V> pl = p.left, pr = p.right;
2584 >                    if ((ph = p.hash) > h)
2585 >                        p = pl;
2586 >                    else if (ph < h)
2587 >                        p = pr;
2588 >                    else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2589 >                        return p;
2590 >                    else if (pl == null)
2591 >                        p = pr;
2592 >                    else if (pr == null)
2593 >                        p = pl;
2594 >                    else if ((kc != null ||
2595 >                              (kc = comparableClassFor(k)) != null) &&
2596 >                             (dir = compareComparables(kc, k, pk)) != 0)
2597 >                        p = (dir < 0) ? pl : pr;
2598 >                    else if ((q = pr.findTreeNode(h, k, kc)) != null)
2599 >                        return q;
2600 >                    else
2601 >                        p = pl;
2602 >                } while (p != null);
2603 >            }
2604 >            return null;
2605 >        }
2606 >    }
2607 >
2608 >    /* ---------------- TreeBins -------------- */
2609 >
2610 >    /**
2611 >     * TreeNodes used at the heads of bins. TreeBins do not hold user
2612 >     * keys or values, but instead point to list of TreeNodes and
2613 >     * their root. They also maintain a parasitic read-write lock
2614 >     * forcing writers (who hold bin lock) to wait for readers (who do
2615 >     * not) to complete before tree restructuring operations.
2616 >     */
2617 >    static final class TreeBin<K,V> extends Node<K,V> {
2618 >        TreeNode<K,V> root;
2619 >        volatile TreeNode<K,V> first;
2620 >        volatile Thread waiter;
2621 >        volatile int lockState;
2622 >        // values for lockState
2623 >        static final int WRITER = 1; // set while holding write lock
2624 >        static final int WAITER = 2; // set when waiting for write lock
2625 >        static final int READER = 4; // increment value for setting read lock
2626 >
2627 >        /**
2628 >         * Tie-breaking utility for ordering insertions when equal
2629 >         * hashCodes and non-comparable. We don't require a total
2630 >         * order, just a consistent insertion rule to maintain
2631 >         * equivalence across rebalancings. Tie-breaking further than
2632 >         * necessary simplifies testing a bit.
2633 >         */
2634 >        static int tieBreakOrder(Object a, Object b) {
2635 >            int d;
2636 >            if (a == null || b == null ||
2637 >                (d = a.getClass().getName().
2638 >                 compareTo(b.getClass().getName())) == 0)
2639 >                d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2640 >                     -1 : 1);
2641 >            return d;
2642 >        }
2643 >
2644 >        /**
2645 >         * Creates bin with initial set of nodes headed by b.
2646 >         */
2647 >        TreeBin(TreeNode<K,V> b) {
2648 >            super(TREEBIN, null, null, null);
2649 >            this.first = b;
2650 >            TreeNode<K,V> r = null;
2651 >            for (TreeNode<K,V> x = b, next; x != null; x = next) {
2652 >                next = (TreeNode<K,V>)x.next;
2653 >                x.left = x.right = null;
2654 >                if (r == null) {
2655 >                    x.parent = null;
2656 >                    x.red = false;
2657 >                    r = x;
2658 >                }
2659 >                else {
2660 >                    K k = x.key;
2661 >                    int h = x.hash;
2662 >                    Class<?> kc = null;
2663 >                    for (TreeNode<K,V> p = r;;) {
2664 >                        int dir, ph;
2665 >                        K pk = p.key;
2666 >                        if ((ph = p.hash) > h)
2667 >                            dir = -1;
2668 >                        else if (ph < h)
2669 >                            dir = 1;
2670 >                        else if ((kc == null &&
2671 >                                  (kc = comparableClassFor(k)) == null) ||
2672 >                                 (dir = compareComparables(kc, k, pk)) == 0)
2673 >                            dir = tieBreakOrder(k, pk);
2674 >                            TreeNode<K,V> xp = p;
2675 >                        if ((p = (dir <= 0) ? p.left : p.right) == null) {
2676 >                            x.parent = xp;
2677 >                            if (dir <= 0)
2678 >                                xp.left = x;
2679 >                            else
2680 >                                xp.right = x;
2681 >                            r = balanceInsertion(r, x);
2682 >                            break;
2683 >                        }
2684 >                    }
2685 >                }
2686 >            }
2687 >            this.root = r;
2688 >            assert checkInvariants(root);
2689 >        }
2690 >
2691 >        /**
2692 >         * Acquires write lock for tree restructuring.
2693 >         */
2694 >        private final void lockRoot() {
2695 >            if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2696 >                contendedLock(); // offload to separate method
2697 >        }
2698 >
2699 >        /**
2700 >         * Releases write lock for tree restructuring.
2701 >         */
2702 >        private final void unlockRoot() {
2703 >            lockState = 0;
2704 >        }
2705 >
2706 >        /**
2707 >         * Possibly blocks awaiting root lock.
2708 >         */
2709 >        private final void contendedLock() {
2710 >            boolean waiting = false;
2711 >            for (int s;;) {
2712 >                if (((s = lockState) & ~WAITER) == 0) {
2713 >                    if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2714 >                        if (waiting)
2715 >                            waiter = null;
2716 >                        return;
2717 >                    }
2718 >                }
2719 >                else if ((s & WAITER) == 0) {
2720 >                    if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2721 >                        waiting = true;
2722 >                        waiter = Thread.currentThread();
2723 >                    }
2724 >                }
2725 >                else if (waiting)
2726 >                    LockSupport.park(this);
2727 >            }
2728 >        }
2729 >
2730 >        /**
2731 >         * Returns matching node or null if none. Tries to search
2732 >         * using tree comparisons from root, but continues linear
2733 >         * search when lock not available.
2734 >         */
2735 >        final Node<K,V> find(int h, Object k) {
2736 >            if (k != null) {
2737 >                for (Node<K,V> e = first; e != null; ) {
2738 >                    int s; K ek;
2739 >                    if (((s = lockState) & (WAITER|WRITER)) != 0) {
2740 >                        if (e.hash == h &&
2741 >                            ((ek = e.key) == k || (ek != null && k.equals(ek))))
2742 >                            return e;
2743 >                        e = e.next;
2744 >                    }
2745 >                    else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2746 >                                                 s + READER)) {
2747 >                        TreeNode<K,V> r, p;
2748 >                        try {
2749 >                            p = ((r = root) == null ? null :
2750 >                                 r.findTreeNode(h, k, null));
2751 >                        } finally {
2752 >                            Thread w;
2753 >                            int ls;
2754 >                            do {} while (!U.compareAndSwapInt
2755 >                                         (this, LOCKSTATE,
2756 >                                          ls = lockState, ls - READER));
2757 >                            if (ls == (READER|WAITER) && (w = waiter) != null)
2758 >                                LockSupport.unpark(w);
2759 >                        }
2760 >                        return p;
2761 >                    }
2762 >                }
2763 >            }
2764 >            return null;
2765 >        }
2766 >
2767 >        /**
2768 >         * Finds or adds a node.
2769 >         * @return null if added
2770 >         */
2771 >        final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2772 >            Class<?> kc = null;
2773 >            boolean searched = false;
2774 >            for (TreeNode<K,V> p = root;;) {
2775 >                int dir, ph; K pk;
2776 >                if (p == null) {
2777 >                    first = root = new TreeNode<K,V>(h, k, v, null, null);
2778                      break;
2779 <                sb.append(',').append(' ');
2779 >                }
2780 >                else if ((ph = p.hash) > h)
2781 >                    dir = -1;
2782 >                else if (ph < h)
2783 >                    dir = 1;
2784 >                else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2785 >                    return p;
2786 >                else if ((kc == null &&
2787 >                          (kc = comparableClassFor(k)) == null) ||
2788 >                         (dir = compareComparables(kc, k, pk)) == 0) {
2789 >                    if (!searched) {
2790 >                        TreeNode<K,V> q, ch;
2791 >                        searched = true;
2792 >                        if (((ch = p.left) != null &&
2793 >                             (q = ch.findTreeNode(h, k, kc)) != null) ||
2794 >                            ((ch = p.right) != null &&
2795 >                             (q = ch.findTreeNode(h, k, kc)) != null))
2796 >                            return q;
2797 >                    }
2798 >                    dir = tieBreakOrder(k, pk);
2799 >                }
2800 >
2801 >                TreeNode<K,V> xp = p;
2802 >                if ((p = (dir <= 0) ? p.left : p.right) == null) {
2803 >                    TreeNode<K,V> x, f = first;
2804 >                    first = x = new TreeNode<K,V>(h, k, v, f, xp);
2805 >                    if (f != null)
2806 >                        f.prev = x;
2807 >                    if (dir <= 0)
2808 >                        xp.left = x;
2809 >                    else
2810 >                        xp.right = x;
2811 >                    if (!xp.red)
2812 >                        x.red = true;
2813 >                    else {
2814 >                        lockRoot();
2815 >                        try {
2816 >                            root = balanceInsertion(root, x);
2817 >                        } finally {
2818 >                            unlockRoot();
2819 >                        }
2820 >                    }
2821 >                    break;
2822 >                }
2823              }
2824 +            assert checkInvariants(root);
2825 +            return null;
2826          }
2827 <        return sb.append('}').toString();
2827 >
2828 >        /**
2829 >         * Removes the given node, that must be present before this
2830 >         * call.  This is messier than typical red-black deletion code
2831 >         * because we cannot swap the contents of an interior node
2832 >         * with a leaf successor that is pinned by "next" pointers
2833 >         * that are accessible independently of lock. So instead we
2834 >         * swap the tree linkages.
2835 >         *
2836 >         * @return true if now too small, so should be untreeified
2837 >         */
2838 >        final boolean removeTreeNode(TreeNode<K,V> p) {
2839 >            TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2840 >            TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2841 >            TreeNode<K,V> r, rl;
2842 >            if (pred == null)
2843 >                first = next;
2844 >            else
2845 >                pred.next = next;
2846 >            if (next != null)
2847 >                next.prev = pred;
2848 >            if (first == null) {
2849 >                root = null;
2850 >                return true;
2851 >            }
2852 >            if ((r = root) == null || r.right == null || // too small
2853 >                (rl = r.left) == null || rl.left == null)
2854 >                return true;
2855 >            lockRoot();
2856 >            try {
2857 >                TreeNode<K,V> replacement;
2858 >                TreeNode<K,V> pl = p.left;
2859 >                TreeNode<K,V> pr = p.right;
2860 >                if (pl != null && pr != null) {
2861 >                    TreeNode<K,V> s = pr, sl;
2862 >                    while ((sl = s.left) != null) // find successor
2863 >                        s = sl;
2864 >                    boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2865 >                    TreeNode<K,V> sr = s.right;
2866 >                    TreeNode<K,V> pp = p.parent;
2867 >                    if (s == pr) { // p was s's direct parent
2868 >                        p.parent = s;
2869 >                        s.right = p;
2870 >                    }
2871 >                    else {
2872 >                        TreeNode<K,V> sp = s.parent;
2873 >                        if ((p.parent = sp) != null) {
2874 >                            if (s == sp.left)
2875 >                                sp.left = p;
2876 >                            else
2877 >                                sp.right = p;
2878 >                        }
2879 >                        if ((s.right = pr) != null)
2880 >                            pr.parent = s;
2881 >                    }
2882 >                    p.left = null;
2883 >                    if ((p.right = sr) != null)
2884 >                        sr.parent = p;
2885 >                    if ((s.left = pl) != null)
2886 >                        pl.parent = s;
2887 >                    if ((s.parent = pp) == null)
2888 >                        r = s;
2889 >                    else if (p == pp.left)
2890 >                        pp.left = s;
2891 >                    else
2892 >                        pp.right = s;
2893 >                    if (sr != null)
2894 >                        replacement = sr;
2895 >                    else
2896 >                        replacement = p;
2897 >                }
2898 >                else if (pl != null)
2899 >                    replacement = pl;
2900 >                else if (pr != null)
2901 >                    replacement = pr;
2902 >                else
2903 >                    replacement = p;
2904 >                if (replacement != p) {
2905 >                    TreeNode<K,V> pp = replacement.parent = p.parent;
2906 >                    if (pp == null)
2907 >                        r = replacement;
2908 >                    else if (p == pp.left)
2909 >                        pp.left = replacement;
2910 >                    else
2911 >                        pp.right = replacement;
2912 >                    p.left = p.right = p.parent = null;
2913 >                }
2914 >
2915 >                root = (p.red) ? r : balanceDeletion(r, replacement);
2916 >
2917 >                if (p == replacement) {  // detach pointers
2918 >                    TreeNode<K,V> pp;
2919 >                    if ((pp = p.parent) != null) {
2920 >                        if (p == pp.left)
2921 >                            pp.left = null;
2922 >                        else if (p == pp.right)
2923 >                            pp.right = null;
2924 >                        p.parent = null;
2925 >                    }
2926 >                }
2927 >            } finally {
2928 >                unlockRoot();
2929 >            }
2930 >            assert checkInvariants(root);
2931 >            return false;
2932 >        }
2933 >
2934 >        /* ------------------------------------------------------------ */
2935 >        // Red-black tree methods, all adapted from CLR
2936 >
2937 >        static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2938 >                                              TreeNode<K,V> p) {
2939 >            TreeNode<K,V> r, pp, rl;
2940 >            if (p != null && (r = p.right) != null) {
2941 >                if ((rl = p.right = r.left) != null)
2942 >                    rl.parent = p;
2943 >                if ((pp = r.parent = p.parent) == null)
2944 >                    (root = r).red = false;
2945 >                else if (pp.left == p)
2946 >                    pp.left = r;
2947 >                else
2948 >                    pp.right = r;
2949 >                r.left = p;
2950 >                p.parent = r;
2951 >            }
2952 >            return root;
2953 >        }
2954 >
2955 >        static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2956 >                                               TreeNode<K,V> p) {
2957 >            TreeNode<K,V> l, pp, lr;
2958 >            if (p != null && (l = p.left) != null) {
2959 >                if ((lr = p.left = l.right) != null)
2960 >                    lr.parent = p;
2961 >                if ((pp = l.parent = p.parent) == null)
2962 >                    (root = l).red = false;
2963 >                else if (pp.right == p)
2964 >                    pp.right = l;
2965 >                else
2966 >                    pp.left = l;
2967 >                l.right = p;
2968 >                p.parent = l;
2969 >            }
2970 >            return root;
2971 >        }
2972 >
2973 >        static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2974 >                                                    TreeNode<K,V> x) {
2975 >            x.red = true;
2976 >            for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2977 >                if ((xp = x.parent) == null) {
2978 >                    x.red = false;
2979 >                    return x;
2980 >                }
2981 >                else if (!xp.red || (xpp = xp.parent) == null)
2982 >                    return root;
2983 >                if (xp == (xppl = xpp.left)) {
2984 >                    if ((xppr = xpp.right) != null && xppr.red) {
2985 >                        xppr.red = false;
2986 >                        xp.red = false;
2987 >                        xpp.red = true;
2988 >                        x = xpp;
2989 >                    }
2990 >                    else {
2991 >                        if (x == xp.right) {
2992 >                            root = rotateLeft(root, x = xp);
2993 >                            xpp = (xp = x.parent) == null ? null : xp.parent;
2994 >                        }
2995 >                        if (xp != null) {
2996 >                            xp.red = false;
2997 >                            if (xpp != null) {
2998 >                                xpp.red = true;
2999 >                                root = rotateRight(root, xpp);
3000 >                            }
3001 >                        }
3002 >                    }
3003 >                }
3004 >                else {
3005 >                    if (xppl != null && xppl.red) {
3006 >                        xppl.red = false;
3007 >                        xp.red = false;
3008 >                        xpp.red = true;
3009 >                        x = xpp;
3010 >                    }
3011 >                    else {
3012 >                        if (x == xp.left) {
3013 >                            root = rotateRight(root, x = xp);
3014 >                            xpp = (xp = x.parent) == null ? null : xp.parent;
3015 >                        }
3016 >                        if (xp != null) {
3017 >                            xp.red = false;
3018 >                            if (xpp != null) {
3019 >                                xpp.red = true;
3020 >                                root = rotateLeft(root, xpp);
3021 >                            }
3022 >                        }
3023 >                    }
3024 >                }
3025 >            }
3026 >        }
3027 >
3028 >        static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3029 >                                                   TreeNode<K,V> x) {
3030 >            for (TreeNode<K,V> xp, xpl, xpr;;) {
3031 >                if (x == null || x == root)
3032 >                    return root;
3033 >                else if ((xp = x.parent) == null) {
3034 >                    x.red = false;
3035 >                    return x;
3036 >                }
3037 >                else if (x.red) {
3038 >                    x.red = false;
3039 >                    return root;
3040 >                }
3041 >                else if ((xpl = xp.left) == x) {
3042 >                    if ((xpr = xp.right) != null && xpr.red) {
3043 >                        xpr.red = false;
3044 >                        xp.red = true;
3045 >                        root = rotateLeft(root, xp);
3046 >                        xpr = (xp = x.parent) == null ? null : xp.right;
3047 >                    }
3048 >                    if (xpr == null)
3049 >                        x = xp;
3050 >                    else {
3051 >                        TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3052 >                        if ((sr == null || !sr.red) &&
3053 >                            (sl == null || !sl.red)) {
3054 >                            xpr.red = true;
3055 >                            x = xp;
3056 >                        }
3057 >                        else {
3058 >                            if (sr == null || !sr.red) {
3059 >                                if (sl != null)
3060 >                                    sl.red = false;
3061 >                                xpr.red = true;
3062 >                                root = rotateRight(root, xpr);
3063 >                                xpr = (xp = x.parent) == null ?
3064 >                                    null : xp.right;
3065 >                            }
3066 >                            if (xpr != null) {
3067 >                                xpr.red = (xp == null) ? false : xp.red;
3068 >                                if ((sr = xpr.right) != null)
3069 >                                    sr.red = false;
3070 >                            }
3071 >                            if (xp != null) {
3072 >                                xp.red = false;
3073 >                                root = rotateLeft(root, xp);
3074 >                            }
3075 >                            x = root;
3076 >                        }
3077 >                    }
3078 >                }
3079 >                else { // symmetric
3080 >                    if (xpl != null && xpl.red) {
3081 >                        xpl.red = false;
3082 >                        xp.red = true;
3083 >                        root = rotateRight(root, xp);
3084 >                        xpl = (xp = x.parent) == null ? null : xp.left;
3085 >                    }
3086 >                    if (xpl == null)
3087 >                        x = xp;
3088 >                    else {
3089 >                        TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3090 >                        if ((sl == null || !sl.red) &&
3091 >                            (sr == null || !sr.red)) {
3092 >                            xpl.red = true;
3093 >                            x = xp;
3094 >                        }
3095 >                        else {
3096 >                            if (sl == null || !sl.red) {
3097 >                                if (sr != null)
3098 >                                    sr.red = false;
3099 >                                xpl.red = true;
3100 >                                root = rotateLeft(root, xpl);
3101 >                                xpl = (xp = x.parent) == null ?
3102 >                                    null : xp.left;
3103 >                            }
3104 >                            if (xpl != null) {
3105 >                                xpl.red = (xp == null) ? false : xp.red;
3106 >                                if ((sl = xpl.left) != null)
3107 >                                    sl.red = false;
3108 >                            }
3109 >                            if (xp != null) {
3110 >                                xp.red = false;
3111 >                                root = rotateRight(root, xp);
3112 >                            }
3113 >                            x = root;
3114 >                        }
3115 >                    }
3116 >                }
3117 >            }
3118 >        }
3119 >
3120 >        /**
3121 >         * Recursive invariant check
3122 >         */
3123 >        static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3124 >            TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3125 >                tb = t.prev, tn = (TreeNode<K,V>)t.next;
3126 >            if (tb != null && tb.next != t)
3127 >                return false;
3128 >            if (tn != null && tn.prev != t)
3129 >                return false;
3130 >            if (tp != null && t != tp.left && t != tp.right)
3131 >                return false;
3132 >            if (tl != null && (tl.parent != t || tl.hash > t.hash))
3133 >                return false;
3134 >            if (tr != null && (tr.parent != t || tr.hash < t.hash))
3135 >                return false;
3136 >            if (t.red && tl != null && tl.red && tr != null && tr.red)
3137 >                return false;
3138 >            if (tl != null && !checkInvariants(tl))
3139 >                return false;
3140 >            if (tr != null && !checkInvariants(tr))
3141 >                return false;
3142 >            return true;
3143 >        }
3144 >
3145 >        private static final sun.misc.Unsafe U;
3146 >        private static final long LOCKSTATE;
3147 >        static {
3148 >            try {
3149 >                U = getUnsafe();
3150 >                Class<?> k = TreeBin.class;
3151 >                LOCKSTATE = U.objectFieldOffset
3152 >                    (k.getDeclaredField("lockState"));
3153 >            } catch (Exception e) {
3154 >                throw new Error(e);
3155 >            }
3156 >        }
3157 >    }
3158 >
3159 >    /* ----------------Table Traversal -------------- */
3160 >
3161 >    /**
3162 >     * Records the table, its length, and current traversal index for a
3163 >     * traverser that must process a region of a forwarded table before
3164 >     * proceeding with current table.
3165 >     */
3166 >    static final class TableStack<K,V> {
3167 >        int length;
3168 >        int index;
3169 >        Node<K,V>[] tab;
3170 >        TableStack<K,V> next;
3171      }
3172  
3173      /**
3174 <     * Compares the specified object with this map for equality.
3175 <     * Returns {@code true} if the given object is a map with the same
3138 <     * mappings as this map.  This operation may return misleading
3139 <     * results if either map is concurrently modified during execution
3140 <     * of this method.
3174 >     * Encapsulates traversal for methods such as containsValue; also
3175 >     * serves as a base class for other iterators and spliterators.
3176       *
3177 <     * @param o object to be compared for equality with this map
3178 <     * @return {@code true} if the specified object is equal to this map
3177 >     * Method advance visits once each still-valid node that was
3178 >     * reachable upon iterator construction. It might miss some that
3179 >     * were added to a bin after the bin was visited, which is OK wrt
3180 >     * consistency guarantees. Maintaining this property in the face
3181 >     * of possible ongoing resizes requires a fair amount of
3182 >     * bookkeeping state that is difficult to optimize away amidst
3183 >     * volatile accesses.  Even so, traversal maintains reasonable
3184 >     * throughput.
3185 >     *
3186 >     * Normally, iteration proceeds bin-by-bin traversing lists.
3187 >     * However, if the table has been resized, then all future steps
3188 >     * must traverse both the bin at the current index as well as at
3189 >     * (index + baseSize); and so on for further resizings. To
3190 >     * paranoically cope with potential sharing by users of iterators
3191 >     * across threads, iteration terminates if a bounds checks fails
3192 >     * for a table read.
3193       */
3194 <    public boolean equals(Object o) {
3195 <        if (o != this) {
3196 <            if (!(o instanceof Map))
3197 <                return false;
3198 <            Map<?,?> m = (Map<?,?>) o;
3199 <            Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3200 <            Object val;
3201 <            while ((val = it.advance()) != null) {
3202 <                Object v = m.get(it.nextKey);
3203 <                if (v == null || (v != val && !v.equals(val)))
3204 <                    return false;
3194 >    static class Traverser<K,V> {
3195 >        Node<K,V>[] tab;        // current table; updated if resized
3196 >        Node<K,V> next;         // the next entry to use
3197 >        TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3198 >        int index;              // index of bin to use next
3199 >        int baseIndex;          // current index of initial table
3200 >        int baseLimit;          // index bound for initial table
3201 >        final int baseSize;     // initial table size
3202 >
3203 >        Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3204 >            this.tab = tab;
3205 >            this.baseSize = size;
3206 >            this.baseIndex = this.index = index;
3207 >            this.baseLimit = limit;
3208 >            this.next = null;
3209 >        }
3210 >
3211 >        /**
3212 >         * Advances if possible, returning next valid node, or null if none.
3213 >         */
3214 >        final Node<K,V> advance() {
3215 >            Node<K,V> e;
3216 >            if ((e = next) != null)
3217 >                e = e.next;
3218 >            for (;;) {
3219 >                Node<K,V>[] t; int i, n;  // must use locals in checks
3220 >                if (e != null)
3221 >                    return next = e;
3222 >                if (baseIndex >= baseLimit || (t = tab) == null ||
3223 >                    (n = t.length) <= (i = index) || i < 0)
3224 >                    return next = null;
3225 >                if ((e = tabAt(t, i)) != null && e.hash < 0) {
3226 >                    if (e instanceof ForwardingNode) {
3227 >                        tab = ((ForwardingNode<K,V>)e).nextTable;
3228 >                        e = null;
3229 >                        pushState(t, i, n);
3230 >                        continue;
3231 >                    }
3232 >                    else if (e instanceof TreeBin)
3233 >                        e = ((TreeBin<K,V>)e).first;
3234 >                    else
3235 >                        e = null;
3236 >                }
3237 >                if (stack != null)
3238 >                    recoverState(n);
3239 >                else if ((index = i + baseSize) >= n)
3240 >                    index = ++baseIndex; // visit upper slots if present
3241              }
3242 <            for (Map.Entry<?,?> e : m.entrySet()) {
3243 <                Object mk, mv, v;
3244 <                if ((mk = e.getKey()) == null ||
3245 <                    (mv = e.getValue()) == null ||
3246 <                    (v = internalGet(mk)) == null ||
3247 <                    (mv != v && !mv.equals(v)))
3248 <                    return false;
3242 >        }
3243 >
3244 >        /**
3245 >         * Saves traversal state upon encountering a forwarding node.
3246 >         */
3247 >        private void pushState(Node<K,V>[] t, int i, int n) {
3248 >            TableStack<K,V> s = spare;  // reuse if possible
3249 >            if (s != null)
3250 >                spare = s.next;
3251 >            else
3252 >                s = new TableStack<K,V>();
3253 >            s.tab = t;
3254 >            s.length = n;
3255 >            s.index = i;
3256 >            s.next = stack;
3257 >            stack = s;
3258 >        }
3259 >
3260 >        /**
3261 >         * Possibly pops traversal state.
3262 >         *
3263 >         * @param n length of current table
3264 >         */
3265 >        private void recoverState(int n) {
3266 >            TableStack<K,V> s; int len;
3267 >            while ((s = stack) != null && (index += (len = s.length)) >= n) {
3268 >                n = len;
3269 >                index = s.index;
3270 >                tab = s.tab;
3271 >                s.tab = null;
3272 >                TableStack<K,V> next = s.next;
3273 >                s.next = spare; // save for reuse
3274 >                stack = next;
3275 >                spare = s;
3276              }
3277 +            if (s == null && (index += baseSize) >= n)
3278 +                index = ++baseIndex;
3279          }
3166        return true;
3280      }
3281  
3282 <    /* ----------------Iterators -------------- */
3283 <
3284 <    @SuppressWarnings("serial") static final class KeyIterator<K,V> extends Traverser<K,V,Object>
3285 <        implements Spliterator<K>, Enumeration<K> {
3286 <        KeyIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3287 <        KeyIterator(Traverser<K,V,Object> it) {
3288 <            super(it);
3282 >    /**
3283 >     * Base of key, value, and entry Iterators. Adds fields to
3284 >     * Traverser to support iterator.remove.
3285 >     */
3286 >    static class BaseIterator<K,V> extends Traverser<K,V> {
3287 >        final ConcurrentHashMapV8<K,V> map;
3288 >        Node<K,V> lastReturned;
3289 >        BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3290 >                    ConcurrentHashMapV8<K,V> map) {
3291 >            super(tab, size, index, limit);
3292 >            this.map = map;
3293 >            advance();
3294          }
3295 <        public KeyIterator<K,V> split() {
3296 <            if (nextKey != null)
3295 >
3296 >        public final boolean hasNext() { return next != null; }
3297 >        public final boolean hasMoreElements() { return next != null; }
3298 >
3299 >        public final void remove() {
3300 >            Node<K,V> p;
3301 >            if ((p = lastReturned) == null)
3302                  throw new IllegalStateException();
3303 <            return new KeyIterator<K,V>(this);
3303 >            lastReturned = null;
3304 >            map.replaceNode(p.key, null, null);
3305          }
3306 <        @SuppressWarnings("unchecked") public final K next() {
3307 <            if (nextVal == null && advance() == null)
3306 >    }
3307 >
3308 >    static final class KeyIterator<K,V> extends BaseIterator<K,V>
3309 >        implements Iterator<K>, Enumeration<K> {
3310 >        KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3311 >                    ConcurrentHashMapV8<K,V> map) {
3312 >            super(tab, index, size, limit, map);
3313 >        }
3314 >
3315 >        public final K next() {
3316 >            Node<K,V> p;
3317 >            if ((p = next) == null)
3318                  throw new NoSuchElementException();
3319 <            Object k = nextKey;
3320 <            nextVal = null;
3321 <            return (K) k;
3319 >            K k = p.key;
3320 >            lastReturned = p;
3321 >            advance();
3322 >            return k;
3323          }
3324  
3325          public final K nextElement() { return next(); }
3326      }
3327  
3328 <    @SuppressWarnings("serial") static final class ValueIterator<K,V> extends Traverser<K,V,Object>
3329 <        implements Spliterator<V>, Enumeration<V> {
3330 <        ValueIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3331 <        ValueIterator(Traverser<K,V,Object> it) {
3332 <            super(it);
3198 <        }
3199 <        public ValueIterator<K,V> split() {
3200 <            if (nextKey != null)
3201 <                throw new IllegalStateException();
3202 <            return new ValueIterator<K,V>(this);
3328 >    static final class ValueIterator<K,V> extends BaseIterator<K,V>
3329 >        implements Iterator<V>, Enumeration<V> {
3330 >        ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3331 >                      ConcurrentHashMapV8<K,V> map) {
3332 >            super(tab, index, size, limit, map);
3333          }
3334  
3335 <        @SuppressWarnings("unchecked") public final V next() {
3336 <            Object v;
3337 <            if ((v = nextVal) == null && (v = advance()) == null)
3335 >        public final V next() {
3336 >            Node<K,V> p;
3337 >            if ((p = next) == null)
3338                  throw new NoSuchElementException();
3339 <            nextVal = null;
3340 <            return (V) v;
3339 >            V v = p.val;
3340 >            lastReturned = p;
3341 >            advance();
3342 >            return v;
3343          }
3344  
3345          public final V nextElement() { return next(); }
3346      }
3347  
3348 <    @SuppressWarnings("serial") static final class EntryIterator<K,V> extends Traverser<K,V,Object>
3349 <        implements Spliterator<Map.Entry<K,V>> {
3350 <        EntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3351 <        EntryIterator(Traverser<K,V,Object> it) {
3352 <            super(it);
3221 <        }
3222 <        public EntryIterator<K,V> split() {
3223 <            if (nextKey != null)
3224 <                throw new IllegalStateException();
3225 <            return new EntryIterator<K,V>(this);
3348 >    static final class EntryIterator<K,V> extends BaseIterator<K,V>
3349 >        implements Iterator<Map.Entry<K,V>> {
3350 >        EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3351 >                      ConcurrentHashMapV8<K,V> map) {
3352 >            super(tab, index, size, limit, map);
3353          }
3354  
3355 <        @SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
3356 <            Object v;
3357 <            if ((v = nextVal) == null && (v = advance()) == null)
3355 >        public final Map.Entry<K,V> next() {
3356 >            Node<K,V> p;
3357 >            if ((p = next) == null)
3358                  throw new NoSuchElementException();
3359 <            Object k = nextKey;
3360 <            nextVal = null;
3361 <            return new MapEntry<K,V>((K)k, (V)v, map);
3359 >            K k = p.key;
3360 >            V v = p.val;
3361 >            lastReturned = p;
3362 >            advance();
3363 >            return new MapEntry<K,V>(k, v, map);
3364          }
3365      }
3366  
3367      /**
3368 <     * Exported Entry for iterators
3368 >     * Exported Entry for EntryIterator
3369       */
3370 <    static final class MapEntry<K,V> implements Map.Entry<K, V> {
3370 >    static final class MapEntry<K,V> implements Map.Entry<K,V> {
3371          final K key; // non-null
3372          V val;       // non-null
3373 <        final ConcurrentHashMapV8<K, V> map;
3374 <        MapEntry(K key, V val, ConcurrentHashMapV8<K, V> map) {
3373 >        final ConcurrentHashMapV8<K,V> map;
3374 >        MapEntry(K key, V val, ConcurrentHashMapV8<K,V> map) {
3375              this.key = key;
3376              this.val = val;
3377              this.map = map;
3378          }
3379 <        public final K getKey()       { return key; }
3380 <        public final V getValue()     { return val; }
3381 <        public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3382 <        public final String toString(){ return key + "=" + val; }
3379 >        public K getKey()        { return key; }
3380 >        public V getValue()      { return val; }
3381 >        public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3382 >        public String toString() { return key + "=" + val; }
3383  
3384 <        public final boolean equals(Object o) {
3384 >        public boolean equals(Object o) {
3385              Object k, v; Map.Entry<?,?> e;
3386              return ((o instanceof Map.Entry) &&
3387                      (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
# Line 3266 | Line 3395 | public class ConcurrentHashMapV8<K, V>
3395           * value to return is somewhat arbitrary here. Since we do not
3396           * necessarily track asynchronous changes, the most recent
3397           * "previous" value could be different from what we return (or
3398 <         * could even have been removed in which case the put will
3398 >         * could even have been removed, in which case the put will
3399           * re-establish). We do not and cannot guarantee more.
3400           */
3401 <        public final V setValue(V value) {
3401 >        public V setValue(V value) {
3402              if (value == null) throw new NullPointerException();
3403              V v = val;
3404              val = value;
# Line 3278 | Line 3407 | public class ConcurrentHashMapV8<K, V>
3407          }
3408      }
3409  
3410 <    /* ---------------- Serialization Support -------------- */
3410 >    static final class KeySpliterator<K,V> extends Traverser<K,V>
3411 >        implements ConcurrentHashMapSpliterator<K> {
3412 >        long est;               // size estimate
3413 >        KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3414 >                       long est) {
3415 >            super(tab, size, index, limit);
3416 >            this.est = est;
3417 >        }
3418 >
3419 >        public ConcurrentHashMapSpliterator<K> trySplit() {
3420 >            int i, f, h;
3421 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3422 >                new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3423 >                                        f, est >>>= 1);
3424 >        }
3425  
3426 <    /**
3427 <     * Stripped-down version of helper class used in previous version,
3428 <     * declared for the sake of serialization compatibility
3429 <     */
3430 <    static class Segment<K,V> implements Serializable {
3288 <        private static final long serialVersionUID = 2249069246763182397L;
3289 <        final float loadFactor;
3290 <        Segment(float lf) { this.loadFactor = lf; }
3291 <    }
3426 >        public void forEachRemaining(Action<? super K> action) {
3427 >            if (action == null) throw new NullPointerException();
3428 >            for (Node<K,V> p; (p = advance()) != null;)
3429 >                action.apply(p.key);
3430 >        }
3431  
3432 <    /**
3433 <     * Saves the state of the {@code ConcurrentHashMapV8} instance to a
3434 <     * stream (i.e., serializes it).
3435 <     * @param s the stream
3436 <     * @serialData
3437 <     * the key (Object) and value (Object)
3438 <     * for each key-value mapping, followed by a null pair.
3300 <     * The key-value mappings are emitted in no particular order.
3301 <     */
3302 <    @SuppressWarnings("unchecked") private void writeObject(java.io.ObjectOutputStream s)
3303 <        throws java.io.IOException {
3304 <        if (segments == null) { // for serialization compatibility
3305 <            segments = (Segment<K,V>[])
3306 <                new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3307 <            for (int i = 0; i < segments.length; ++i)
3308 <                segments[i] = new Segment<K,V>(LOAD_FACTOR);
3309 <        }
3310 <        s.defaultWriteObject();
3311 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3312 <        Object v;
3313 <        while ((v = it.advance()) != null) {
3314 <            s.writeObject(it.nextKey);
3315 <            s.writeObject(v);
3432 >        public boolean tryAdvance(Action<? super K> action) {
3433 >            if (action == null) throw new NullPointerException();
3434 >            Node<K,V> p;
3435 >            if ((p = advance()) == null)
3436 >                return false;
3437 >            action.apply(p.key);
3438 >            return true;
3439          }
3440 <        s.writeObject(null);
3441 <        s.writeObject(null);
3442 <        segments = null; // throw away
3440 >
3441 >        public long estimateSize() { return est; }
3442 >
3443      }
3444  
3445 <    /**
3446 <     * Reconstitutes the instance from a stream (that is, deserializes it).
3447 <     * @param s the stream
3448 <     */
3449 <    @SuppressWarnings("unchecked") private void readObject(java.io.ObjectInputStream s)
3450 <        throws java.io.IOException, ClassNotFoundException {
3451 <        s.defaultReadObject();
3452 <        this.segments = null; // unneeded
3330 <        // initialize transient final field
3331 <        UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
3445 >    static final class ValueSpliterator<K,V> extends Traverser<K,V>
3446 >        implements ConcurrentHashMapSpliterator<V> {
3447 >        long est;               // size estimate
3448 >        ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3449 >                         long est) {
3450 >            super(tab, size, index, limit);
3451 >            this.est = est;
3452 >        }
3453  
3454 <        // Create all nodes, then place in table once size is known
3455 <        long size = 0L;
3456 <        Node p = null;
3457 <        for (;;) {
3458 <            K k = (K) s.readObject();
3338 <            V v = (V) s.readObject();
3339 <            if (k != null && v != null) {
3340 <                int h = spread(k.hashCode());
3341 <                p = new Node(h, k, v, p);
3342 <                ++size;
3343 <            }
3344 <            else
3345 <                break;
3454 >        public ConcurrentHashMapSpliterator<V> trySplit() {
3455 >            int i, f, h;
3456 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3457 >                new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3458 >                                          f, est >>>= 1);
3459          }
3460 <        if (p != null) {
3461 <            boolean init = false;
3462 <            int n;
3463 <            if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3464 <                n = MAXIMUM_CAPACITY;
3352 <            else {
3353 <                int sz = (int)size;
3354 <                n = tableSizeFor(sz + (sz >>> 1) + 1);
3355 <            }
3356 <            int sc = sizeCtl;
3357 <            boolean collide = false;
3358 <            if (n > sc &&
3359 <                UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
3360 <                try {
3361 <                    if (table == null) {
3362 <                        init = true;
3363 <                        Node[] tab = new Node[n];
3364 <                        int mask = n - 1;
3365 <                        while (p != null) {
3366 <                            int j = p.hash & mask;
3367 <                            Node next = p.next;
3368 <                            Node q = p.next = tabAt(tab, j);
3369 <                            setTabAt(tab, j, p);
3370 <                            if (!collide && q != null && q.hash == p.hash)
3371 <                                collide = true;
3372 <                            p = next;
3373 <                        }
3374 <                        table = tab;
3375 <                        counter.add(size);
3376 <                        sc = n - (n >>> 2);
3377 <                    }
3378 <                } finally {
3379 <                    sizeCtl = sc;
3380 <                }
3381 <                if (collide) { // rescan and convert to TreeBins
3382 <                    Node[] tab = table;
3383 <                    for (int i = 0; i < tab.length; ++i) {
3384 <                        int c = 0;
3385 <                        for (Node e = tabAt(tab, i); e != null; e = e.next) {
3386 <                            if (++c > TREE_THRESHOLD &&
3387 <                                (e.key instanceof Comparable)) {
3388 <                                replaceWithTreeBin(tab, i, e.key);
3389 <                                break;
3390 <                            }
3391 <                        }
3392 <                    }
3393 <                }
3394 <            }
3395 <            if (!init) { // Can only happen if unsafely published.
3396 <                while (p != null) {
3397 <                    internalPut(p.key, p.val);
3398 <                    p = p.next;
3399 <                }
3400 <            }
3460 >
3461 >        public void forEachRemaining(Action<? super V> action) {
3462 >            if (action == null) throw new NullPointerException();
3463 >            for (Node<K,V> p; (p = advance()) != null;)
3464 >                action.apply(p.val);
3465          }
3466 +
3467 +        public boolean tryAdvance(Action<? super V> action) {
3468 +            if (action == null) throw new NullPointerException();
3469 +            Node<K,V> p;
3470 +            if ((p = advance()) == null)
3471 +                return false;
3472 +            action.apply(p.val);
3473 +            return true;
3474 +        }
3475 +
3476 +        public long estimateSize() { return est; }
3477 +
3478      }
3479  
3480 +    static final class EntrySpliterator<K,V> extends Traverser<K,V>
3481 +        implements ConcurrentHashMapSpliterator<Map.Entry<K,V>> {
3482 +        final ConcurrentHashMapV8<K,V> map; // To export MapEntry
3483 +        long est;               // size estimate
3484 +        EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3485 +                         long est, ConcurrentHashMapV8<K,V> map) {
3486 +            super(tab, size, index, limit);
3487 +            this.map = map;
3488 +            this.est = est;
3489 +        }
3490  
3491 <    // -------------------------------------------------------
3491 >        public ConcurrentHashMapSpliterator<Map.Entry<K,V>> trySplit() {
3492 >            int i, f, h;
3493 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3494 >                new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3495 >                                          f, est >>>= 1, map);
3496 >        }
3497  
3498 <    // Sams
3499 <    /** Interface describing a void action of one argument */
3500 <    public interface Action<A> { void apply(A a); }
3501 <    /** Interface describing a void action of two arguments */
3502 <    public interface BiAction<A,B> { void apply(A a, B b); }
3412 <    /** Interface describing a function of one argument */
3413 <    public interface Fun<A,T> { T apply(A a); }
3414 <    /** Interface describing a function of two arguments */
3415 <    public interface BiFun<A,B,T> { T apply(A a, B b); }
3416 <    /** Interface describing a function of no arguments */
3417 <    public interface Generator<T> { T apply(); }
3418 <    /** Interface describing a function mapping its argument to a double */
3419 <    public interface ObjectToDouble<A> { double apply(A a); }
3420 <    /** Interface describing a function mapping its argument to a long */
3421 <    public interface ObjectToLong<A> { long apply(A a); }
3422 <    /** Interface describing a function mapping its argument to an int */
3423 <    public interface ObjectToInt<A> {int apply(A a); }
3424 <    /** Interface describing a function mapping two arguments to a double */
3425 <    public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
3426 <    /** Interface describing a function mapping two arguments to a long */
3427 <    public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
3428 <    /** Interface describing a function mapping two arguments to an int */
3429 <    public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
3430 <    /** Interface describing a function mapping a double to a double */
3431 <    public interface DoubleToDouble { double apply(double a); }
3432 <    /** Interface describing a function mapping a long to a long */
3433 <    public interface LongToLong { long apply(long a); }
3434 <    /** Interface describing a function mapping an int to an int */
3435 <    public interface IntToInt { int apply(int a); }
3436 <    /** Interface describing a function mapping two doubles to a double */
3437 <    public interface DoubleByDoubleToDouble { double apply(double a, double b); }
3438 <    /** Interface describing a function mapping two longs to a long */
3439 <    public interface LongByLongToLong { long apply(long a, long b); }
3440 <    /** Interface describing a function mapping two ints to an int */
3441 <    public interface IntByIntToInt { int apply(int a, int b); }
3498 >        public void forEachRemaining(Action<? super Map.Entry<K,V>> action) {
3499 >            if (action == null) throw new NullPointerException();
3500 >            for (Node<K,V> p; (p = advance()) != null; )
3501 >                action.apply(new MapEntry<K,V>(p.key, p.val, map));
3502 >        }
3503  
3504 +        public boolean tryAdvance(Action<? super Map.Entry<K,V>> action) {
3505 +            if (action == null) throw new NullPointerException();
3506 +            Node<K,V> p;
3507 +            if ((p = advance()) == null)
3508 +                return false;
3509 +            action.apply(new MapEntry<K,V>(p.key, p.val, map));
3510 +            return true;
3511 +        }
3512  
3513 <    // -------------------------------------------------------
3513 >        public long estimateSize() { return est; }
3514 >
3515 >    }
3516 >
3517 >    // Parallel bulk operations
3518 >
3519 >    /**
3520 >     * Computes initial batch value for bulk tasks. The returned value
3521 >     * is approximately exp2 of the number of times (minus one) to
3522 >     * split task by two before executing leaf action. This value is
3523 >     * faster to compute and more convenient to use as a guide to
3524 >     * splitting than is the depth, since it is used while dividing by
3525 >     * two anyway.
3526 >     */
3527 >    final int batchFor(long b) {
3528 >        long n;
3529 >        if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3530 >            return 0;
3531 >        int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3532 >        return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3533 >    }
3534  
3535      /**
3536       * Performs the given action for each (key, value).
3537       *
3538 +     * @param parallelismThreshold the (estimated) number of elements
3539 +     * needed for this operation to be executed in parallel
3540       * @param action the action
3541 +     * @since 1.8
3542       */
3543 <    public void forEach(BiAction<K,V> action) {
3544 <        ForkJoinTasks.forEach
3545 <            (this, action).invoke();
3543 >    public void forEach(long parallelismThreshold,
3544 >                        BiAction<? super K,? super V> action) {
3545 >        if (action == null) throw new NullPointerException();
3546 >        new ForEachMappingTask<K,V>
3547 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3548 >             action).invoke();
3549      }
3550  
3551      /**
3552       * Performs the given action for each non-null transformation
3553       * of each (key, value).
3554       *
3555 +     * @param parallelismThreshold the (estimated) number of elements
3556 +     * needed for this operation to be executed in parallel
3557       * @param transformer a function returning the transformation
3558 <     * for an element, or null of there is no transformation (in
3559 <     * which case the action is not applied).
3558 >     * for an element, or null if there is no transformation (in
3559 >     * which case the action is not applied)
3560       * @param action the action
3561 +     * @since 1.8
3562       */
3563 <    public <U> void forEach(BiFun<? super K, ? super V, ? extends U> transformer,
3564 <                            Action<U> action) {
3565 <        ForkJoinTasks.forEach
3566 <            (this, transformer, action).invoke();
3563 >    public <U> void forEach(long parallelismThreshold,
3564 >                            BiFun<? super K, ? super V, ? extends U> transformer,
3565 >                            Action<? super U> action) {
3566 >        if (transformer == null || action == null)
3567 >            throw new NullPointerException();
3568 >        new ForEachTransformedMappingTask<K,V,U>
3569 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3570 >             transformer, action).invoke();
3571      }
3572  
3573      /**
# Line 3475 | Line 3577 | public class ConcurrentHashMapV8<K, V>
3577       * results of any other parallel invocations of the search
3578       * function are ignored.
3579       *
3580 +     * @param parallelismThreshold the (estimated) number of elements
3581 +     * needed for this operation to be executed in parallel
3582       * @param searchFunction a function returning a non-null
3583       * result on success, else null
3584       * @return a non-null result from applying the given search
3585       * function on each (key, value), or null if none
3586 +     * @since 1.8
3587       */
3588 <    public <U> U search(BiFun<? super K, ? super V, ? extends U> searchFunction) {
3589 <        return ForkJoinTasks.search
3590 <            (this, searchFunction).invoke();
3588 >    public <U> U search(long parallelismThreshold,
3589 >                        BiFun<? super K, ? super V, ? extends U> searchFunction) {
3590 >        if (searchFunction == null) throw new NullPointerException();
3591 >        return new SearchMappingsTask<K,V,U>
3592 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3593 >             searchFunction, new AtomicReference<U>()).invoke();
3594      }
3595  
3596      /**
# Line 3490 | Line 3598 | public class ConcurrentHashMapV8<K, V>
3598       * of all (key, value) pairs using the given reducer to
3599       * combine values, or null if none.
3600       *
3601 +     * @param parallelismThreshold the (estimated) number of elements
3602 +     * needed for this operation to be executed in parallel
3603       * @param transformer a function returning the transformation
3604 <     * for an element, or null of there is no transformation (in
3605 <     * which case it is not combined).
3604 >     * for an element, or null if there is no transformation (in
3605 >     * which case it is not combined)
3606       * @param reducer a commutative associative combining function
3607       * @return the result of accumulating the given transformation
3608       * of all (key, value) pairs
3609 +     * @since 1.8
3610       */
3611 <    public <U> U reduce(BiFun<? super K, ? super V, ? extends U> transformer,
3611 >    public <U> U reduce(long parallelismThreshold,
3612 >                        BiFun<? super K, ? super V, ? extends U> transformer,
3613                          BiFun<? super U, ? super U, ? extends U> reducer) {
3614 <        return ForkJoinTasks.reduce
3615 <            (this, transformer, reducer).invoke();
3614 >        if (transformer == null || reducer == null)
3615 >            throw new NullPointerException();
3616 >        return new MapReduceMappingsTask<K,V,U>
3617 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3618 >             null, transformer, reducer).invoke();
3619      }
3620  
3621      /**
# Line 3508 | Line 3623 | public class ConcurrentHashMapV8<K, V>
3623       * of all (key, value) pairs using the given reducer to
3624       * combine values, and the given basis as an identity value.
3625       *
3626 +     * @param parallelismThreshold the (estimated) number of elements
3627 +     * needed for this operation to be executed in parallel
3628       * @param transformer a function returning the transformation
3629       * for an element
3630       * @param basis the identity (initial default value) for the reduction
3631       * @param reducer a commutative associative combining function
3632       * @return the result of accumulating the given transformation
3633       * of all (key, value) pairs
3634 +     * @since 1.8
3635       */
3636 <    public double reduceToDouble(ObjectByObjectToDouble<? super K, ? super V> transformer,
3636 >    public double reduceToDouble(long parallelismThreshold,
3637 >                                 ObjectByObjectToDouble<? super K, ? super V> transformer,
3638                                   double basis,
3639                                   DoubleByDoubleToDouble reducer) {
3640 <        return ForkJoinTasks.reduceToDouble
3641 <            (this, transformer, basis, reducer).invoke();
3640 >        if (transformer == null || reducer == null)
3641 >            throw new NullPointerException();
3642 >        return new MapReduceMappingsToDoubleTask<K,V>
3643 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3644 >             null, transformer, basis, reducer).invoke();
3645      }
3646  
3647      /**
# Line 3527 | Line 3649 | public class ConcurrentHashMapV8<K, V>
3649       * of all (key, value) pairs using the given reducer to
3650       * combine values, and the given basis as an identity value.
3651       *
3652 +     * @param parallelismThreshold the (estimated) number of elements
3653 +     * needed for this operation to be executed in parallel
3654       * @param transformer a function returning the transformation
3655       * for an element
3656       * @param basis the identity (initial default value) for the reduction
3657       * @param reducer a commutative associative combining function
3658       * @return the result of accumulating the given transformation
3659       * of all (key, value) pairs
3660 +     * @since 1.8
3661       */
3662 <    public long reduceToLong(ObjectByObjectToLong<? super K, ? super V> transformer,
3662 >    public long reduceToLong(long parallelismThreshold,
3663 >                             ObjectByObjectToLong<? super K, ? super V> transformer,
3664                               long basis,
3665                               LongByLongToLong reducer) {
3666 <        return ForkJoinTasks.reduceToLong
3667 <            (this, transformer, basis, reducer).invoke();
3666 >        if (transformer == null || reducer == null)
3667 >            throw new NullPointerException();
3668 >        return new MapReduceMappingsToLongTask<K,V>
3669 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3670 >             null, transformer, basis, reducer).invoke();
3671      }
3672  
3673      /**
# Line 3546 | Line 3675 | public class ConcurrentHashMapV8<K, V>
3675       * of all (key, value) pairs using the given reducer to
3676       * combine values, and the given basis as an identity value.
3677       *
3678 +     * @param parallelismThreshold the (estimated) number of elements
3679 +     * needed for this operation to be executed in parallel
3680       * @param transformer a function returning the transformation
3681       * for an element
3682       * @param basis the identity (initial default value) for the reduction
3683       * @param reducer a commutative associative combining function
3684       * @return the result of accumulating the given transformation
3685       * of all (key, value) pairs
3686 +     * @since 1.8
3687       */
3688 <    public int reduceToInt(ObjectByObjectToInt<? super K, ? super V> transformer,
3688 >    public int reduceToInt(long parallelismThreshold,
3689 >                           ObjectByObjectToInt<? super K, ? super V> transformer,
3690                             int basis,
3691                             IntByIntToInt reducer) {
3692 <        return ForkJoinTasks.reduceToInt
3693 <            (this, transformer, basis, reducer).invoke();
3692 >        if (transformer == null || reducer == null)
3693 >            throw new NullPointerException();
3694 >        return new MapReduceMappingsToIntTask<K,V>
3695 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3696 >             null, transformer, basis, reducer).invoke();
3697      }
3698  
3699      /**
3700       * Performs the given action for each key.
3701       *
3702 +     * @param parallelismThreshold the (estimated) number of elements
3703 +     * needed for this operation to be executed in parallel
3704       * @param action the action
3705 +     * @since 1.8
3706       */
3707 <    public void forEachKey(Action<K> action) {
3708 <        ForkJoinTasks.forEachKey
3709 <            (this, action).invoke();
3707 >    public void forEachKey(long parallelismThreshold,
3708 >                           Action<? super K> action) {
3709 >        if (action == null) throw new NullPointerException();
3710 >        new ForEachKeyTask<K,V>
3711 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3712 >             action).invoke();
3713      }
3714  
3715      /**
3716       * Performs the given action for each non-null transformation
3717       * of each key.
3718       *
3719 +     * @param parallelismThreshold the (estimated) number of elements
3720 +     * needed for this operation to be executed in parallel
3721       * @param transformer a function returning the transformation
3722 <     * for an element, or null of there is no transformation (in
3723 <     * which case the action is not applied).
3722 >     * for an element, or null if there is no transformation (in
3723 >     * which case the action is not applied)
3724       * @param action the action
3725 +     * @since 1.8
3726       */
3727 <    public <U> void forEachKey(Fun<? super K, ? extends U> transformer,
3728 <                               Action<U> action) {
3729 <        ForkJoinTasks.forEachKey
3730 <            (this, transformer, action).invoke();
3727 >    public <U> void forEachKey(long parallelismThreshold,
3728 >                               Fun<? super K, ? extends U> transformer,
3729 >                               Action<? super U> action) {
3730 >        if (transformer == null || action == null)
3731 >            throw new NullPointerException();
3732 >        new ForEachTransformedKeyTask<K,V,U>
3733 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3734 >             transformer, action).invoke();
3735      }
3736  
3737      /**
# Line 3592 | Line 3741 | public class ConcurrentHashMapV8<K, V>
3741       * any other parallel invocations of the search function are
3742       * ignored.
3743       *
3744 +     * @param parallelismThreshold the (estimated) number of elements
3745 +     * needed for this operation to be executed in parallel
3746       * @param searchFunction a function returning a non-null
3747       * result on success, else null
3748       * @return a non-null result from applying the given search
3749       * function on each key, or null if none
3750 +     * @since 1.8
3751       */
3752 <    public <U> U searchKeys(Fun<? super K, ? extends U> searchFunction) {
3753 <        return ForkJoinTasks.searchKeys
3754 <            (this, searchFunction).invoke();
3752 >    public <U> U searchKeys(long parallelismThreshold,
3753 >                            Fun<? super K, ? extends U> searchFunction) {
3754 >        if (searchFunction == null) throw new NullPointerException();
3755 >        return new SearchKeysTask<K,V,U>
3756 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3757 >             searchFunction, new AtomicReference<U>()).invoke();
3758      }
3759  
3760      /**
3761       * Returns the result of accumulating all keys using the given
3762       * reducer to combine values, or null if none.
3763       *
3764 +     * @param parallelismThreshold the (estimated) number of elements
3765 +     * needed for this operation to be executed in parallel
3766       * @param reducer a commutative associative combining function
3767       * @return the result of accumulating all keys using the given
3768       * reducer to combine values, or null if none
3769 +     * @since 1.8
3770       */
3771 <    public K reduceKeys(BiFun<? super K, ? super K, ? extends K> reducer) {
3772 <        return ForkJoinTasks.reduceKeys
3773 <            (this, reducer).invoke();
3771 >    public K reduceKeys(long parallelismThreshold,
3772 >                        BiFun<? super K, ? super K, ? extends K> reducer) {
3773 >        if (reducer == null) throw new NullPointerException();
3774 >        return new ReduceKeysTask<K,V>
3775 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3776 >             null, reducer).invoke();
3777      }
3778  
3779      /**
# Line 3620 | Line 3781 | public class ConcurrentHashMapV8<K, V>
3781       * of all keys using the given reducer to combine values, or
3782       * null if none.
3783       *
3784 +     * @param parallelismThreshold the (estimated) number of elements
3785 +     * needed for this operation to be executed in parallel
3786       * @param transformer a function returning the transformation
3787 <     * for an element, or null of there is no transformation (in
3788 <     * which case it is not combined).
3787 >     * for an element, or null if there is no transformation (in
3788 >     * which case it is not combined)
3789       * @param reducer a commutative associative combining function
3790       * @return the result of accumulating the given transformation
3791       * of all keys
3792 +     * @since 1.8
3793       */
3794 <    public <U> U reduceKeys(Fun<? super K, ? extends U> transformer,
3795 <                            BiFun<? super U, ? super U, ? extends U> reducer) {
3796 <        return ForkJoinTasks.reduceKeys
3797 <            (this, transformer, reducer).invoke();
3794 >    public <U> U reduceKeys(long parallelismThreshold,
3795 >                            Fun<? super K, ? extends U> transformer,
3796 >         BiFun<? super U, ? super U, ? extends U> reducer) {
3797 >        if (transformer == null || reducer == null)
3798 >            throw new NullPointerException();
3799 >        return new MapReduceKeysTask<K,V,U>
3800 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3801 >             null, transformer, reducer).invoke();
3802      }
3803  
3804      /**
# Line 3638 | Line 3806 | public class ConcurrentHashMapV8<K, V>
3806       * of all keys using the given reducer to combine values, and
3807       * the given basis as an identity value.
3808       *
3809 +     * @param parallelismThreshold the (estimated) number of elements
3810 +     * needed for this operation to be executed in parallel
3811       * @param transformer a function returning the transformation
3812       * for an element
3813       * @param basis the identity (initial default value) for the reduction
3814       * @param reducer a commutative associative combining function
3815 <     * @return  the result of accumulating the given transformation
3815 >     * @return the result of accumulating the given transformation
3816       * of all keys
3817 +     * @since 1.8
3818       */
3819 <    public double reduceKeysToDouble(ObjectToDouble<? super K> transformer,
3819 >    public double reduceKeysToDouble(long parallelismThreshold,
3820 >                                     ObjectToDouble<? super K> transformer,
3821                                       double basis,
3822                                       DoubleByDoubleToDouble reducer) {
3823 <        return ForkJoinTasks.reduceKeysToDouble
3824 <            (this, transformer, basis, reducer).invoke();
3823 >        if (transformer == null || reducer == null)
3824 >            throw new NullPointerException();
3825 >        return new MapReduceKeysToDoubleTask<K,V>
3826 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3827 >             null, transformer, basis, reducer).invoke();
3828      }
3829  
3830      /**
# Line 3657 | Line 3832 | public class ConcurrentHashMapV8<K, V>
3832       * of all keys using the given reducer to combine values, and
3833       * the given basis as an identity value.
3834       *
3835 +     * @param parallelismThreshold the (estimated) number of elements
3836 +     * needed for this operation to be executed in parallel
3837       * @param transformer a function returning the transformation
3838       * for an element
3839       * @param basis the identity (initial default value) for the reduction
3840       * @param reducer a commutative associative combining function
3841       * @return the result of accumulating the given transformation
3842       * of all keys
3843 +     * @since 1.8
3844       */
3845 <    public long reduceKeysToLong(ObjectToLong<? super K> transformer,
3845 >    public long reduceKeysToLong(long parallelismThreshold,
3846 >                                 ObjectToLong<? super K> transformer,
3847                                   long basis,
3848                                   LongByLongToLong reducer) {
3849 <        return ForkJoinTasks.reduceKeysToLong
3850 <            (this, transformer, basis, reducer).invoke();
3849 >        if (transformer == null || reducer == null)
3850 >            throw new NullPointerException();
3851 >        return new MapReduceKeysToLongTask<K,V>
3852 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3853 >             null, transformer, basis, reducer).invoke();
3854      }
3855  
3856      /**
# Line 3676 | Line 3858 | public class ConcurrentHashMapV8<K, V>
3858       * of all keys using the given reducer to combine values, and
3859       * the given basis as an identity value.
3860       *
3861 +     * @param parallelismThreshold the (estimated) number of elements
3862 +     * needed for this operation to be executed in parallel
3863       * @param transformer a function returning the transformation
3864       * for an element
3865       * @param basis the identity (initial default value) for the reduction
3866       * @param reducer a commutative associative combining function
3867       * @return the result of accumulating the given transformation
3868       * of all keys
3869 +     * @since 1.8
3870       */
3871 <    public int reduceKeysToInt(ObjectToInt<? super K> transformer,
3871 >    public int reduceKeysToInt(long parallelismThreshold,
3872 >                               ObjectToInt<? super K> transformer,
3873                                 int basis,
3874                                 IntByIntToInt reducer) {
3875 <        return ForkJoinTasks.reduceKeysToInt
3876 <            (this, transformer, basis, reducer).invoke();
3875 >        if (transformer == null || reducer == null)
3876 >            throw new NullPointerException();
3877 >        return new MapReduceKeysToIntTask<K,V>
3878 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3879 >             null, transformer, basis, reducer).invoke();
3880      }
3881  
3882      /**
3883       * Performs the given action for each value.
3884       *
3885 +     * @param parallelismThreshold the (estimated) number of elements
3886 +     * needed for this operation to be executed in parallel
3887       * @param action the action
3888 +     * @since 1.8
3889       */
3890 <    public void forEachValue(Action<V> action) {
3891 <        ForkJoinTasks.forEachValue
3892 <            (this, action).invoke();
3890 >    public void forEachValue(long parallelismThreshold,
3891 >                             Action<? super V> action) {
3892 >        if (action == null)
3893 >            throw new NullPointerException();
3894 >        new ForEachValueTask<K,V>
3895 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3896 >             action).invoke();
3897      }
3898  
3899      /**
3900       * Performs the given action for each non-null transformation
3901       * of each value.
3902       *
3903 +     * @param parallelismThreshold the (estimated) number of elements
3904 +     * needed for this operation to be executed in parallel
3905       * @param transformer a function returning the transformation
3906 <     * for an element, or null of there is no transformation (in
3907 <     * which case the action is not applied).
3906 >     * for an element, or null if there is no transformation (in
3907 >     * which case the action is not applied)
3908 >     * @param action the action
3909 >     * @since 1.8
3910       */
3911 <    public <U> void forEachValue(Fun<? super V, ? extends U> transformer,
3912 <                                 Action<U> action) {
3913 <        ForkJoinTasks.forEachValue
3914 <            (this, transformer, action).invoke();
3911 >    public <U> void forEachValue(long parallelismThreshold,
3912 >                                 Fun<? super V, ? extends U> transformer,
3913 >                                 Action<? super U> action) {
3914 >        if (transformer == null || action == null)
3915 >            throw new NullPointerException();
3916 >        new ForEachTransformedValueTask<K,V,U>
3917 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3918 >             transformer, action).invoke();
3919      }
3920  
3921      /**
# Line 3721 | Line 3925 | public class ConcurrentHashMapV8<K, V>
3925       * any other parallel invocations of the search function are
3926       * ignored.
3927       *
3928 +     * @param parallelismThreshold the (estimated) number of elements
3929 +     * needed for this operation to be executed in parallel
3930       * @param searchFunction a function returning a non-null
3931       * result on success, else null
3932       * @return a non-null result from applying the given search
3933       * function on each value, or null if none
3934 <     *
3934 >     * @since 1.8
3935       */
3936 <    public <U> U searchValues(Fun<? super V, ? extends U> searchFunction) {
3937 <        return ForkJoinTasks.searchValues
3938 <            (this, searchFunction).invoke();
3936 >    public <U> U searchValues(long parallelismThreshold,
3937 >                              Fun<? super V, ? extends U> searchFunction) {
3938 >        if (searchFunction == null) throw new NullPointerException();
3939 >        return new SearchValuesTask<K,V,U>
3940 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3941 >             searchFunction, new AtomicReference<U>()).invoke();
3942      }
3943  
3944      /**
3945       * Returns the result of accumulating all values using the
3946       * given reducer to combine values, or null if none.
3947       *
3948 +     * @param parallelismThreshold the (estimated) number of elements
3949 +     * needed for this operation to be executed in parallel
3950       * @param reducer a commutative associative combining function
3951 <     * @return  the result of accumulating all values
3951 >     * @return the result of accumulating all values
3952 >     * @since 1.8
3953       */
3954 <    public V reduceValues(BiFun<? super V, ? super V, ? extends V> reducer) {
3955 <        return ForkJoinTasks.reduceValues
3956 <            (this, reducer).invoke();
3954 >    public V reduceValues(long parallelismThreshold,
3955 >                          BiFun<? super V, ? super V, ? extends V> reducer) {
3956 >        if (reducer == null) throw new NullPointerException();
3957 >        return new ReduceValuesTask<K,V>
3958 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3959 >             null, reducer).invoke();
3960      }
3961  
3962      /**
# Line 3749 | Line 3964 | public class ConcurrentHashMapV8<K, V>
3964       * of all values using the given reducer to combine values, or
3965       * null if none.
3966       *
3967 +     * @param parallelismThreshold the (estimated) number of elements
3968 +     * needed for this operation to be executed in parallel
3969       * @param transformer a function returning the transformation
3970 <     * for an element, or null of there is no transformation (in
3971 <     * which case it is not combined).
3970 >     * for an element, or null if there is no transformation (in
3971 >     * which case it is not combined)
3972       * @param reducer a commutative associative combining function
3973       * @return the result of accumulating the given transformation
3974       * of all values
3975 +     * @since 1.8
3976       */
3977 <    public <U> U reduceValues(Fun<? super V, ? extends U> transformer,
3977 >    public <U> U reduceValues(long parallelismThreshold,
3978 >                              Fun<? super V, ? extends U> transformer,
3979                                BiFun<? super U, ? super U, ? extends U> reducer) {
3980 <        return ForkJoinTasks.reduceValues
3981 <            (this, transformer, reducer).invoke();
3980 >        if (transformer == null || reducer == null)
3981 >            throw new NullPointerException();
3982 >        return new MapReduceValuesTask<K,V,U>
3983 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3984 >             null, transformer, reducer).invoke();
3985      }
3986  
3987      /**
# Line 3767 | Line 3989 | public class ConcurrentHashMapV8<K, V>
3989       * of all values using the given reducer to combine values,
3990       * and the given basis as an identity value.
3991       *
3992 +     * @param parallelismThreshold the (estimated) number of elements
3993 +     * needed for this operation to be executed in parallel
3994       * @param transformer a function returning the transformation
3995       * for an element
3996       * @param basis the identity (initial default value) for the reduction
3997       * @param reducer a commutative associative combining function
3998       * @return the result of accumulating the given transformation
3999       * of all values
4000 +     * @since 1.8
4001       */
4002 <    public double reduceValuesToDouble(ObjectToDouble<? super V> transformer,
4002 >    public double reduceValuesToDouble(long parallelismThreshold,
4003 >                                       ObjectToDouble<? super V> transformer,
4004                                         double basis,
4005                                         DoubleByDoubleToDouble reducer) {
4006 <        return ForkJoinTasks.reduceValuesToDouble
4007 <            (this, transformer, basis, reducer).invoke();
4006 >        if (transformer == null || reducer == null)
4007 >            throw new NullPointerException();
4008 >        return new MapReduceValuesToDoubleTask<K,V>
4009 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4010 >             null, transformer, basis, reducer).invoke();
4011      }
4012  
4013      /**
# Line 3786 | Line 4015 | public class ConcurrentHashMapV8<K, V>
4015       * of all values using the given reducer to combine values,
4016       * and the given basis as an identity value.
4017       *
4018 +     * @param parallelismThreshold the (estimated) number of elements
4019 +     * needed for this operation to be executed in parallel
4020       * @param transformer a function returning the transformation
4021       * for an element
4022       * @param basis the identity (initial default value) for the reduction
4023       * @param reducer a commutative associative combining function
4024       * @return the result of accumulating the given transformation
4025       * of all values
4026 +     * @since 1.8
4027       */
4028 <    public long reduceValuesToLong(ObjectToLong<? super V> transformer,
4028 >    public long reduceValuesToLong(long parallelismThreshold,
4029 >                                   ObjectToLong<? super V> transformer,
4030                                     long basis,
4031                                     LongByLongToLong reducer) {
4032 <        return ForkJoinTasks.reduceValuesToLong
4033 <            (this, transformer, basis, reducer).invoke();
4032 >        if (transformer == null || reducer == null)
4033 >            throw new NullPointerException();
4034 >        return new MapReduceValuesToLongTask<K,V>
4035 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4036 >             null, transformer, basis, reducer).invoke();
4037      }
4038  
4039      /**
# Line 3805 | Line 4041 | public class ConcurrentHashMapV8<K, V>
4041       * of all values using the given reducer to combine values,
4042       * and the given basis as an identity value.
4043       *
4044 +     * @param parallelismThreshold the (estimated) number of elements
4045 +     * needed for this operation to be executed in parallel
4046       * @param transformer a function returning the transformation
4047       * for an element
4048       * @param basis the identity (initial default value) for the reduction
4049       * @param reducer a commutative associative combining function
4050       * @return the result of accumulating the given transformation
4051       * of all values
4052 +     * @since 1.8
4053       */
4054 <    public int reduceValuesToInt(ObjectToInt<? super V> transformer,
4054 >    public int reduceValuesToInt(long parallelismThreshold,
4055 >                                 ObjectToInt<? super V> transformer,
4056                                   int basis,
4057                                   IntByIntToInt reducer) {
4058 <        return ForkJoinTasks.reduceValuesToInt
4059 <            (this, transformer, basis, reducer).invoke();
4058 >        if (transformer == null || reducer == null)
4059 >            throw new NullPointerException();
4060 >        return new MapReduceValuesToIntTask<K,V>
4061 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4062 >             null, transformer, basis, reducer).invoke();
4063      }
4064  
4065      /**
4066       * Performs the given action for each entry.
4067       *
4068 +     * @param parallelismThreshold the (estimated) number of elements
4069 +     * needed for this operation to be executed in parallel
4070       * @param action the action
4071 +     * @since 1.8
4072       */
4073 <    public void forEachEntry(Action<Map.Entry<K,V>> action) {
4074 <        ForkJoinTasks.forEachEntry
4075 <            (this, action).invoke();
4073 >    public void forEachEntry(long parallelismThreshold,
4074 >                             Action<? super Map.Entry<K,V>> action) {
4075 >        if (action == null) throw new NullPointerException();
4076 >        new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4077 >                                  action).invoke();
4078      }
4079  
4080      /**
4081       * Performs the given action for each non-null transformation
4082       * of each entry.
4083       *
4084 +     * @param parallelismThreshold the (estimated) number of elements
4085 +     * needed for this operation to be executed in parallel
4086       * @param transformer a function returning the transformation
4087 <     * for an element, or null of there is no transformation (in
4088 <     * which case the action is not applied).
4087 >     * for an element, or null if there is no transformation (in
4088 >     * which case the action is not applied)
4089       * @param action the action
4090 +     * @since 1.8
4091       */
4092 <    public <U> void forEachEntry(Fun<Map.Entry<K,V>, ? extends U> transformer,
4093 <                                 Action<U> action) {
4094 <        ForkJoinTasks.forEachEntry
4095 <            (this, transformer, action).invoke();
4092 >    public <U> void forEachEntry(long parallelismThreshold,
4093 >                                 Fun<Map.Entry<K,V>, ? extends U> transformer,
4094 >                                 Action<? super U> action) {
4095 >        if (transformer == null || action == null)
4096 >            throw new NullPointerException();
4097 >        new ForEachTransformedEntryTask<K,V,U>
4098 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4099 >             transformer, action).invoke();
4100      }
4101  
4102      /**
# Line 3851 | Line 4106 | public class ConcurrentHashMapV8<K, V>
4106       * any other parallel invocations of the search function are
4107       * ignored.
4108       *
4109 +     * @param parallelismThreshold the (estimated) number of elements
4110 +     * needed for this operation to be executed in parallel
4111       * @param searchFunction a function returning a non-null
4112       * result on success, else null
4113       * @return a non-null result from applying the given search
4114       * function on each entry, or null if none
4115 +     * @since 1.8
4116       */
4117 <    public <U> U searchEntries(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4118 <        return ForkJoinTasks.searchEntries
4119 <            (this, searchFunction).invoke();
4117 >    public <U> U searchEntries(long parallelismThreshold,
4118 >                               Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4119 >        if (searchFunction == null) throw new NullPointerException();
4120 >        return new SearchEntriesTask<K,V,U>
4121 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4122 >             searchFunction, new AtomicReference<U>()).invoke();
4123      }
4124  
4125      /**
4126       * Returns the result of accumulating all entries using the
4127       * given reducer to combine values, or null if none.
4128       *
4129 +     * @param parallelismThreshold the (estimated) number of elements
4130 +     * needed for this operation to be executed in parallel
4131       * @param reducer a commutative associative combining function
4132       * @return the result of accumulating all entries
4133 +     * @since 1.8
4134       */
4135 <    public Map.Entry<K,V> reduceEntries(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4136 <        return ForkJoinTasks.reduceEntries
4137 <            (this, reducer).invoke();
4135 >    public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4136 >                                        BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4137 >        if (reducer == null) throw new NullPointerException();
4138 >        return new ReduceEntriesTask<K,V>
4139 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4140 >             null, reducer).invoke();
4141      }
4142  
4143      /**
# Line 3878 | Line 4145 | public class ConcurrentHashMapV8<K, V>
4145       * of all entries using the given reducer to combine values,
4146       * or null if none.
4147       *
4148 +     * @param parallelismThreshold the (estimated) number of elements
4149 +     * needed for this operation to be executed in parallel
4150       * @param transformer a function returning the transformation
4151 <     * for an element, or null of there is no transformation (in
4152 <     * which case it is not combined).
4151 >     * for an element, or null if there is no transformation (in
4152 >     * which case it is not combined)
4153       * @param reducer a commutative associative combining function
4154       * @return the result of accumulating the given transformation
4155       * of all entries
4156 +     * @since 1.8
4157       */
4158 <    public <U> U reduceEntries(Fun<Map.Entry<K,V>, ? extends U> transformer,
4158 >    public <U> U reduceEntries(long parallelismThreshold,
4159 >                               Fun<Map.Entry<K,V>, ? extends U> transformer,
4160                                 BiFun<? super U, ? super U, ? extends U> reducer) {
4161 <        return ForkJoinTasks.reduceEntries
4162 <            (this, transformer, reducer).invoke();
4161 >        if (transformer == null || reducer == null)
4162 >            throw new NullPointerException();
4163 >        return new MapReduceEntriesTask<K,V,U>
4164 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4165 >             null, transformer, reducer).invoke();
4166      }
4167  
4168      /**
# Line 3896 | Line 4170 | public class ConcurrentHashMapV8<K, V>
4170       * of all entries using the given reducer to combine values,
4171       * and the given basis as an identity value.
4172       *
4173 +     * @param parallelismThreshold the (estimated) number of elements
4174 +     * needed for this operation to be executed in parallel
4175       * @param transformer a function returning the transformation
4176       * for an element
4177       * @param basis the identity (initial default value) for the reduction
4178       * @param reducer a commutative associative combining function
4179       * @return the result of accumulating the given transformation
4180       * of all entries
4181 +     * @since 1.8
4182       */
4183 <    public double reduceEntriesToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
4183 >    public double reduceEntriesToDouble(long parallelismThreshold,
4184 >                                        ObjectToDouble<Map.Entry<K,V>> transformer,
4185                                          double basis,
4186                                          DoubleByDoubleToDouble reducer) {
4187 <        return ForkJoinTasks.reduceEntriesToDouble
4188 <            (this, transformer, basis, reducer).invoke();
4187 >        if (transformer == null || reducer == null)
4188 >            throw new NullPointerException();
4189 >        return new MapReduceEntriesToDoubleTask<K,V>
4190 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4191 >             null, transformer, basis, reducer).invoke();
4192      }
4193  
4194      /**
# Line 3915 | Line 4196 | public class ConcurrentHashMapV8<K, V>
4196       * of all entries using the given reducer to combine values,
4197       * and the given basis as an identity value.
4198       *
4199 +     * @param parallelismThreshold the (estimated) number of elements
4200 +     * needed for this operation to be executed in parallel
4201       * @param transformer a function returning the transformation
4202       * for an element
4203       * @param basis the identity (initial default value) for the reduction
4204       * @param reducer a commutative associative combining function
4205 <     * @return  the result of accumulating the given transformation
4205 >     * @return the result of accumulating the given transformation
4206       * of all entries
4207 +     * @since 1.8
4208       */
4209 <    public long reduceEntriesToLong(ObjectToLong<Map.Entry<K,V>> transformer,
4209 >    public long reduceEntriesToLong(long parallelismThreshold,
4210 >                                    ObjectToLong<Map.Entry<K,V>> transformer,
4211                                      long basis,
4212                                      LongByLongToLong reducer) {
4213 <        return ForkJoinTasks.reduceEntriesToLong
4214 <            (this, transformer, basis, reducer).invoke();
4213 >        if (transformer == null || reducer == null)
4214 >            throw new NullPointerException();
4215 >        return new MapReduceEntriesToLongTask<K,V>
4216 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4217 >             null, transformer, basis, reducer).invoke();
4218      }
4219  
4220      /**
# Line 3934 | Line 4222 | public class ConcurrentHashMapV8<K, V>
4222       * of all entries using the given reducer to combine values,
4223       * and the given basis as an identity value.
4224       *
4225 +     * @param parallelismThreshold the (estimated) number of elements
4226 +     * needed for this operation to be executed in parallel
4227       * @param transformer a function returning the transformation
4228       * for an element
4229       * @param basis the identity (initial default value) for the reduction
4230       * @param reducer a commutative associative combining function
4231       * @return the result of accumulating the given transformation
4232       * of all entries
4233 +     * @since 1.8
4234       */
4235 <    public int reduceEntriesToInt(ObjectToInt<Map.Entry<K,V>> transformer,
4235 >    public int reduceEntriesToInt(long parallelismThreshold,
4236 >                                  ObjectToInt<Map.Entry<K,V>> transformer,
4237                                    int basis,
4238                                    IntByIntToInt reducer) {
4239 <        return ForkJoinTasks.reduceEntriesToInt
4240 <            (this, transformer, basis, reducer).invoke();
4239 >        if (transformer == null || reducer == null)
4240 >            throw new NullPointerException();
4241 >        return new MapReduceEntriesToIntTask<K,V>
4242 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4243 >             null, transformer, basis, reducer).invoke();
4244      }
4245  
4246 +
4247      /* ----------------Views -------------- */
4248  
4249      /**
4250       * Base class for views.
4251       */
4252 <    static abstract class CHMView<K, V> {
4253 <        final ConcurrentHashMapV8<K, V> map;
4254 <        CHMView(ConcurrentHashMapV8<K, V> map)  { this.map = map; }
4252 >    abstract static class CollectionView<K,V,E>
4253 >        implements Collection<E>, java.io.Serializable {
4254 >        private static final long serialVersionUID = 7249069246763182397L;
4255 >        final ConcurrentHashMapV8<K,V> map;
4256 >        CollectionView(ConcurrentHashMapV8<K,V> map)  { this.map = map; }
4257  
4258          /**
4259           * Returns the map backing this view.
# Line 3964 | Line 4262 | public class ConcurrentHashMapV8<K, V>
4262           */
4263          public ConcurrentHashMapV8<K,V> getMap() { return map; }
4264  
4265 <        public final int size()                 { return map.size(); }
4266 <        public final boolean isEmpty()          { return map.isEmpty(); }
4267 <        public final void clear()               { map.clear(); }
4265 >        /**
4266 >         * Removes all of the elements from this view, by removing all
4267 >         * the mappings from the map backing this view.
4268 >         */
4269 >        public final void clear()      { map.clear(); }
4270 >        public final int size()        { return map.size(); }
4271 >        public final boolean isEmpty() { return map.isEmpty(); }
4272  
4273          // implementations below rely on concrete classes supplying these
4274 <        abstract public Iterator<?> iterator();
4275 <        abstract public boolean contains(Object o);
4276 <        abstract public boolean remove(Object o);
4274 >        // abstract methods
4275 >        /**
4276 >         * Returns a "weakly consistent" iterator that will never
4277 >         * throw {@link ConcurrentModificationException}, and
4278 >         * guarantees to traverse elements as they existed upon
4279 >         * construction of the iterator, and may (but is not
4280 >         * guaranteed to) reflect any modifications subsequent to
4281 >         * construction.
4282 >         */
4283 >        public abstract Iterator<E> iterator();
4284 >        public abstract boolean contains(Object o);
4285 >        public abstract boolean remove(Object o);
4286  
4287          private static final String oomeMsg = "Required array size too large";
4288  
4289          public final Object[] toArray() {
4290              long sz = map.mappingCount();
4291 <            if (sz > (long)(MAX_ARRAY_SIZE))
4291 >            if (sz > MAX_ARRAY_SIZE)
4292                  throw new OutOfMemoryError(oomeMsg);
4293              int n = (int)sz;
4294              Object[] r = new Object[n];
4295              int i = 0;
4296 <            Iterator<?> it = iterator();
3986 <            while (it.hasNext()) {
4296 >            for (E e : this) {
4297                  if (i == n) {
4298                      if (n >= MAX_ARRAY_SIZE)
4299                          throw new OutOfMemoryError(oomeMsg);
# Line 3993 | Line 4303 | public class ConcurrentHashMapV8<K, V>
4303                          n += (n >>> 1) + 1;
4304                      r = Arrays.copyOf(r, n);
4305                  }
4306 <                r[i++] = it.next();
4306 >                r[i++] = e;
4307              }
4308              return (i == n) ? r : Arrays.copyOf(r, i);
4309          }
4310  
4311 <        @SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4311 >        @SuppressWarnings("unchecked")
4312 >        public final <T> T[] toArray(T[] a) {
4313              long sz = map.mappingCount();
4314 <            if (sz > (long)(MAX_ARRAY_SIZE))
4314 >            if (sz > MAX_ARRAY_SIZE)
4315                  throw new OutOfMemoryError(oomeMsg);
4316              int m = (int)sz;
4317              T[] r = (a.length >= m) ? a :
# Line 4008 | Line 4319 | public class ConcurrentHashMapV8<K, V>
4319                  .newInstance(a.getClass().getComponentType(), m);
4320              int n = r.length;
4321              int i = 0;
4322 <            Iterator<?> it = iterator();
4012 <            while (it.hasNext()) {
4322 >            for (E e : this) {
4323                  if (i == n) {
4324                      if (n >= MAX_ARRAY_SIZE)
4325                          throw new OutOfMemoryError(oomeMsg);
# Line 4019 | Line 4329 | public class ConcurrentHashMapV8<K, V>
4329                          n += (n >>> 1) + 1;
4330                      r = Arrays.copyOf(r, n);
4331                  }
4332 <                r[i++] = (T)it.next();
4332 >                r[i++] = (T)e;
4333              }
4334              if (a == r && i < n) {
4335                  r[i] = null; // null-terminate
# Line 4028 | Line 4338 | public class ConcurrentHashMapV8<K, V>
4338              return (i == n) ? r : Arrays.copyOf(r, i);
4339          }
4340  
4341 <        public final int hashCode() {
4342 <            int h = 0;
4343 <            for (Iterator<?> it = iterator(); it.hasNext();)
4344 <                h += it.next().hashCode();
4345 <            return h;
4346 <        }
4347 <
4341 >        /**
4342 >         * Returns a string representation of this collection.
4343 >         * The string representation consists of the string representations
4344 >         * of the collection's elements in the order they are returned by
4345 >         * its iterator, enclosed in square brackets ({@code "[]"}).
4346 >         * Adjacent elements are separated by the characters {@code ", "}
4347 >         * (comma and space).  Elements are converted to strings as by
4348 >         * {@link String#valueOf(Object)}.
4349 >         *
4350 >         * @return a string representation of this collection
4351 >         */
4352          public final String toString() {
4353              StringBuilder sb = new StringBuilder();
4354              sb.append('[');
4355 <            Iterator<?> it = iterator();
4355 >            Iterator<E> it = iterator();
4356              if (it.hasNext()) {
4357                  for (;;) {
4358                      Object e = it.next();
# Line 4053 | Line 4367 | public class ConcurrentHashMapV8<K, V>
4367  
4368          public final boolean containsAll(Collection<?> c) {
4369              if (c != this) {
4370 <                for (Iterator<?> it = c.iterator(); it.hasNext();) {
4057 <                    Object e = it.next();
4370 >                for (Object e : c) {
4371                      if (e == null || !contains(e))
4372                          return false;
4373                  }
# Line 4064 | Line 4377 | public class ConcurrentHashMapV8<K, V>
4377  
4378          public final boolean removeAll(Collection<?> c) {
4379              boolean modified = false;
4380 <            for (Iterator<?> it = iterator(); it.hasNext();) {
4380 >            for (Iterator<E> it = iterator(); it.hasNext();) {
4381                  if (c.contains(it.next())) {
4382                      it.remove();
4383                      modified = true;
# Line 4075 | Line 4388 | public class ConcurrentHashMapV8<K, V>
4388  
4389          public final boolean retainAll(Collection<?> c) {
4390              boolean modified = false;
4391 <            for (Iterator<?> it = iterator(); it.hasNext();) {
4391 >            for (Iterator<E> it = iterator(); it.hasNext();) {
4392                  if (!c.contains(it.next())) {
4393                      it.remove();
4394                      modified = true;
# Line 4089 | Line 4402 | public class ConcurrentHashMapV8<K, V>
4402      /**
4403       * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in
4404       * which additions may optionally be enabled by mapping to a
4405 <     * common value.  This class cannot be directly instantiated. See
4406 <     * {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4407 <     * {@link #newKeySet(int)}.
4405 >     * common value.  This class cannot be directly instantiated.
4406 >     * See {@link #keySet() keySet()},
4407 >     * {@link #keySet(Object) keySet(V)},
4408 >     * {@link #newKeySet() newKeySet()},
4409 >     * {@link #newKeySet(int) newKeySet(int)}.
4410 >     *
4411 >     * @since 1.8
4412       */
4413 <    public static class KeySetView<K,V> extends CHMView<K,V> implements Set<K>, java.io.Serializable {
4413 >    public static class KeySetView<K,V> extends CollectionView<K,V,K>
4414 >        implements Set<K>, java.io.Serializable {
4415          private static final long serialVersionUID = 7249069246763182397L;
4416          private final V value;
4417 <        KeySetView(ConcurrentHashMapV8<K, V> map, V value) {  // non-public
4417 >        KeySetView(ConcurrentHashMapV8<K,V> map, V value) {  // non-public
4418              super(map);
4419              this.value = value;
4420          }
# Line 4106 | Line 4424 | public class ConcurrentHashMapV8<K, V>
4424           * or {@code null} if additions are not supported.
4425           *
4426           * @return the default mapped value for additions, or {@code null}
4427 <         * if not supported.
4427 >         * if not supported
4428           */
4429          public V getMappedValue() { return value; }
4430  
4431 <        // implement Set API
4432 <
4431 >        /**
4432 >         * {@inheritDoc}
4433 >         * @throws NullPointerException if the specified key is null
4434 >         */
4435          public boolean contains(Object o) { return map.containsKey(o); }
4116        public boolean remove(Object o)   { return map.remove(o) != null; }
4436  
4437          /**
4438 <         * Returns a "weakly consistent" iterator that will never
4439 <         * throw {@link ConcurrentModificationException}, and
4440 <         * guarantees to traverse elements as they existed upon
4122 <         * construction of the iterator, and may (but is not
4123 <         * guaranteed to) reflect any modifications subsequent to
4124 <         * construction.
4438 >         * Removes the key from this map view, by removing the key (and its
4439 >         * corresponding value) from the backing map.  This method does
4440 >         * nothing if the key is not in the map.
4441           *
4442 <         * @return an iterator over the keys of this map
4442 >         * @param  o the key to be removed from the backing map
4443 >         * @return {@code true} if the backing map contained the specified key
4444 >         * @throws NullPointerException if the specified key is null
4445 >         */
4446 >        public boolean remove(Object o) { return map.remove(o) != null; }
4447 >
4448 >        /**
4449 >         * @return an iterator over the keys of the backing map
4450 >         */
4451 >        public Iterator<K> iterator() {
4452 >            Node<K,V>[] t;
4453 >            ConcurrentHashMapV8<K,V> m = map;
4454 >            int f = (t = m.table) == null ? 0 : t.length;
4455 >            return new KeyIterator<K,V>(t, f, 0, f, m);
4456 >        }
4457 >
4458 >        /**
4459 >         * Adds the specified key to this set view by mapping the key to
4460 >         * the default mapped value in the backing map, if defined.
4461 >         *
4462 >         * @param e key to be added
4463 >         * @return {@code true} if this set changed as a result of the call
4464 >         * @throws NullPointerException if the specified key is null
4465 >         * @throws UnsupportedOperationException if no default mapped value
4466 >         * for additions was provided
4467           */
4128        public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4468          public boolean add(K e) {
4469              V v;
4470              if ((v = value) == null)
4471                  throw new UnsupportedOperationException();
4472 <            if (e == null)
4134 <                throw new NullPointerException();
4135 <            return map.internalPutIfAbsent(e, v) == null;
4472 >            return map.putVal(e, v, true) == null;
4473          }
4474 +
4475 +        /**
4476 +         * Adds all of the elements in the specified collection to this set,
4477 +         * as if by calling {@link #add} on each one.
4478 +         *
4479 +         * @param c the elements to be inserted into this set
4480 +         * @return {@code true} if this set changed as a result of the call
4481 +         * @throws NullPointerException if the collection or any of its
4482 +         * elements are {@code null}
4483 +         * @throws UnsupportedOperationException if no default mapped value
4484 +         * for additions was provided
4485 +         */
4486          public boolean addAll(Collection<? extends K> c) {
4487              boolean added = false;
4488              V v;
4489              if ((v = value) == null)
4490                  throw new UnsupportedOperationException();
4491              for (K e : c) {
4492 <                if (e == null)
4144 <                    throw new NullPointerException();
4145 <                if (map.internalPutIfAbsent(e, v) == null)
4492 >                if (map.putVal(e, v, true) == null)
4493                      added = true;
4494              }
4495              return added;
4496          }
4497 +
4498 +        public int hashCode() {
4499 +            int h = 0;
4500 +            for (K e : this)
4501 +                h += e.hashCode();
4502 +            return h;
4503 +        }
4504 +
4505          public boolean equals(Object o) {
4506              Set<?> c;
4507              return ((o instanceof Set) &&
# Line 4154 | Line 4509 | public class ConcurrentHashMapV8<K, V>
4509                       (containsAll(c) && c.containsAll(this))));
4510          }
4511  
4512 <        /**
4513 <         * Performs the given action for each key.
4514 <         *
4515 <         * @param action the action
4516 <         */
4517 <        public void forEach(Action<K> action) {
4163 <            ForkJoinTasks.forEachKey
4164 <                (map, action).invoke();
4512 >        public ConcurrentHashMapSpliterator<K> spliterator() {
4513 >            Node<K,V>[] t;
4514 >            ConcurrentHashMapV8<K,V> m = map;
4515 >            long n = m.sumCount();
4516 >            int f = (t = m.table) == null ? 0 : t.length;
4517 >            return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4518          }
4519  
4520 <        /**
4521 <         * Performs the given action for each non-null transformation
4522 <         * of each key.
4523 <         *
4524 <         * @param transformer a function returning the transformation
4525 <         * for an element, or null of there is no transformation (in
4526 <         * which case the action is not applied).
4527 <         * @param action the action
4175 <         */
4176 <        public <U> void forEach(Fun<? super K, ? extends U> transformer,
4177 <                                Action<U> action) {
4178 <            ForkJoinTasks.forEachKey
4179 <                (map, transformer, action).invoke();
4180 <        }
4181 <
4182 <        /**
4183 <         * Returns a non-null result from applying the given search
4184 <         * function on each key, or null if none. Upon success,
4185 <         * further element processing is suppressed and the results of
4186 <         * any other parallel invocations of the search function are
4187 <         * ignored.
4188 <         *
4189 <         * @param searchFunction a function returning a non-null
4190 <         * result on success, else null
4191 <         * @return a non-null result from applying the given search
4192 <         * function on each key, or null if none
4193 <         */
4194 <        public <U> U search(Fun<? super K, ? extends U> searchFunction) {
4195 <            return ForkJoinTasks.searchKeys
4196 <                (map, searchFunction).invoke();
4197 <        }
4198 <
4199 <        /**
4200 <         * Returns the result of accumulating all keys using the given
4201 <         * reducer to combine values, or null if none.
4202 <         *
4203 <         * @param reducer a commutative associative combining function
4204 <         * @return the result of accumulating all keys using the given
4205 <         * reducer to combine values, or null if none
4206 <         */
4207 <        public K reduce(BiFun<? super K, ? super K, ? extends K> reducer) {
4208 <            return ForkJoinTasks.reduceKeys
4209 <                (map, reducer).invoke();
4210 <        }
4211 <
4212 <        /**
4213 <         * Returns the result of accumulating the given transformation
4214 <         * of all keys using the given reducer to combine values, and
4215 <         * the given basis as an identity value.
4216 <         *
4217 <         * @param transformer a function returning the transformation
4218 <         * for an element
4219 <         * @param basis the identity (initial default value) for the reduction
4220 <         * @param reducer a commutative associative combining function
4221 <         * @return  the result of accumulating the given transformation
4222 <         * of all keys
4223 <         */
4224 <        public double reduceToDouble(ObjectToDouble<? super K> transformer,
4225 <                                     double basis,
4226 <                                     DoubleByDoubleToDouble reducer) {
4227 <            return ForkJoinTasks.reduceKeysToDouble
4228 <                (map, transformer, basis, reducer).invoke();
4229 <        }
4230 <
4231 <
4232 <        /**
4233 <         * Returns the result of accumulating the given transformation
4234 <         * of all keys using the given reducer to combine values, and
4235 <         * the given basis as an identity value.
4236 <         *
4237 <         * @param transformer a function returning the transformation
4238 <         * for an element
4239 <         * @param basis the identity (initial default value) for the reduction
4240 <         * @param reducer a commutative associative combining function
4241 <         * @return the result of accumulating the given transformation
4242 <         * of all keys
4243 <         */
4244 <        public long reduceToLong(ObjectToLong<? super K> transformer,
4245 <                                 long basis,
4246 <                                 LongByLongToLong reducer) {
4247 <            return ForkJoinTasks.reduceKeysToLong
4248 <                (map, transformer, basis, reducer).invoke();
4249 <        }
4250 <
4251 <        /**
4252 <         * Returns the result of accumulating the given transformation
4253 <         * of all keys using the given reducer to combine values, and
4254 <         * the given basis as an identity value.
4255 <         *
4256 <         * @param transformer a function returning the transformation
4257 <         * for an element
4258 <         * @param basis the identity (initial default value) for the reduction
4259 <         * @param reducer a commutative associative combining function
4260 <         * @return the result of accumulating the given transformation
4261 <         * of all keys
4262 <         */
4263 <        public int reduceToInt(ObjectToInt<? super K> transformer,
4264 <                               int basis,
4265 <                               IntByIntToInt reducer) {
4266 <            return ForkJoinTasks.reduceKeysToInt
4267 <                (map, transformer, basis, reducer).invoke();
4520 >        public void forEach(Action<? super K> action) {
4521 >            if (action == null) throw new NullPointerException();
4522 >            Node<K,V>[] t;
4523 >            if ((t = map.table) != null) {
4524 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4525 >                for (Node<K,V> p; (p = it.advance()) != null; )
4526 >                    action.apply(p.key);
4527 >            }
4528          }
4269
4529      }
4530  
4531      /**
4532       * A view of a ConcurrentHashMapV8 as a {@link Collection} of
4533       * values, in which additions are disabled. This class cannot be
4534 <     * directly instantiated. See {@link #values},
4276 <     *
4277 <     * <p>The view's {@code iterator} is a "weakly consistent" iterator
4278 <     * that will never throw {@link ConcurrentModificationException},
4279 <     * and guarantees to traverse elements as they existed upon
4280 <     * construction of the iterator, and may (but is not guaranteed to)
4281 <     * reflect any modifications subsequent to construction.
4534 >     * directly instantiated. See {@link #values()}.
4535       */
4536 <    public static final class ValuesView<K,V> extends CHMView<K,V>
4537 <        implements Collection<V> {
4538 <        ValuesView(ConcurrentHashMapV8<K, V> map)   { super(map); }
4539 <        public final boolean contains(Object o) { return map.containsValue(o); }
4536 >    static final class ValuesView<K,V> extends CollectionView<K,V,V>
4537 >        implements Collection<V>, java.io.Serializable {
4538 >        private static final long serialVersionUID = 2249069246763182397L;
4539 >        ValuesView(ConcurrentHashMapV8<K,V> map) { super(map); }
4540 >        public final boolean contains(Object o) {
4541 >            return map.containsValue(o);
4542 >        }
4543 >
4544          public final boolean remove(Object o) {
4545              if (o != null) {
4546 <                Iterator<V> it = new ValueIterator<K,V>(map);
4290 <                while (it.hasNext()) {
4546 >                for (Iterator<V> it = iterator(); it.hasNext();) {
4547                      if (o.equals(it.next())) {
4548                          it.remove();
4549                          return true;
# Line 4297 | Line 4553 | public class ConcurrentHashMapV8<K, V>
4553              return false;
4554          }
4555  
4300        /**
4301         * Returns a "weakly consistent" iterator that will never
4302         * throw {@link ConcurrentModificationException}, and
4303         * guarantees to traverse elements as they existed upon
4304         * construction of the iterator, and may (but is not
4305         * guaranteed to) reflect any modifications subsequent to
4306         * construction.
4307         *
4308         * @return an iterator over the values of this map
4309         */
4556          public final Iterator<V> iterator() {
4557 <            return new ValueIterator<K,V>(map);
4557 >            ConcurrentHashMapV8<K,V> m = map;
4558 >            Node<K,V>[] t;
4559 >            int f = (t = m.table) == null ? 0 : t.length;
4560 >            return new ValueIterator<K,V>(t, f, 0, f, m);
4561          }
4562 +
4563          public final boolean add(V e) {
4564              throw new UnsupportedOperationException();
4565          }
# Line 4317 | Line 4567 | public class ConcurrentHashMapV8<K, V>
4567              throw new UnsupportedOperationException();
4568          }
4569  
4570 <        /**
4571 <         * Performs the given action for each value.
4572 <         *
4573 <         * @param action the action
4574 <         */
4575 <        public void forEach(Action<V> action) {
4326 <            ForkJoinTasks.forEachValue
4327 <                (map, action).invoke();
4328 <        }
4329 <
4330 <        /**
4331 <         * Performs the given action for each non-null transformation
4332 <         * of each value.
4333 <         *
4334 <         * @param transformer a function returning the transformation
4335 <         * for an element, or null of there is no transformation (in
4336 <         * which case the action is not applied).
4337 <         */
4338 <        public <U> void forEach(Fun<? super V, ? extends U> transformer,
4339 <                                     Action<U> action) {
4340 <            ForkJoinTasks.forEachValue
4341 <                (map, transformer, action).invoke();
4342 <        }
4343 <
4344 <        /**
4345 <         * Returns a non-null result from applying the given search
4346 <         * function on each value, or null if none.  Upon success,
4347 <         * further element processing is suppressed and the results of
4348 <         * any other parallel invocations of the search function are
4349 <         * ignored.
4350 <         *
4351 <         * @param searchFunction a function returning a non-null
4352 <         * result on success, else null
4353 <         * @return a non-null result from applying the given search
4354 <         * function on each value, or null if none
4355 <         *
4356 <         */
4357 <        public <U> U search(Fun<? super V, ? extends U> searchFunction) {
4358 <            return ForkJoinTasks.searchValues
4359 <                (map, searchFunction).invoke();
4360 <        }
4361 <
4362 <        /**
4363 <         * Returns the result of accumulating all values using the
4364 <         * given reducer to combine values, or null if none.
4365 <         *
4366 <         * @param reducer a commutative associative combining function
4367 <         * @return  the result of accumulating all values
4368 <         */
4369 <        public V reduce(BiFun<? super V, ? super V, ? extends V> reducer) {
4370 <            return ForkJoinTasks.reduceValues
4371 <                (map, reducer).invoke();
4372 <        }
4373 <
4374 <        /**
4375 <         * Returns the result of accumulating the given transformation
4376 <         * of all values using the given reducer to combine values, or
4377 <         * null if none.
4378 <         *
4379 <         * @param transformer a function returning the transformation
4380 <         * for an element, or null of there is no transformation (in
4381 <         * which case it is not combined).
4382 <         * @param reducer a commutative associative combining function
4383 <         * @return the result of accumulating the given transformation
4384 <         * of all values
4385 <         */
4386 <        public <U> U reduce(Fun<? super V, ? extends U> transformer,
4387 <                            BiFun<? super U, ? super U, ? extends U> reducer) {
4388 <            return ForkJoinTasks.reduceValues
4389 <                (map, transformer, reducer).invoke();
4390 <        }
4391 <
4392 <        /**
4393 <         * Returns the result of accumulating the given transformation
4394 <         * of all values using the given reducer to combine values,
4395 <         * and the given basis as an identity value.
4396 <         *
4397 <         * @param transformer a function returning the transformation
4398 <         * for an element
4399 <         * @param basis the identity (initial default value) for the reduction
4400 <         * @param reducer a commutative associative combining function
4401 <         * @return the result of accumulating the given transformation
4402 <         * of all values
4403 <         */
4404 <        public double reduceToDouble(ObjectToDouble<? super V> transformer,
4405 <                                     double basis,
4406 <                                     DoubleByDoubleToDouble reducer) {
4407 <            return ForkJoinTasks.reduceValuesToDouble
4408 <                (map, transformer, basis, reducer).invoke();
4409 <        }
4410 <
4411 <        /**
4412 <         * Returns the result of accumulating the given transformation
4413 <         * of all values using the given reducer to combine values,
4414 <         * and the given basis as an identity value.
4415 <         *
4416 <         * @param transformer a function returning the transformation
4417 <         * for an element
4418 <         * @param basis the identity (initial default value) for the reduction
4419 <         * @param reducer a commutative associative combining function
4420 <         * @return the result of accumulating the given transformation
4421 <         * of all values
4422 <         */
4423 <        public long reduceToLong(ObjectToLong<? super V> transformer,
4424 <                                 long basis,
4425 <                                 LongByLongToLong reducer) {
4426 <            return ForkJoinTasks.reduceValuesToLong
4427 <                (map, transformer, basis, reducer).invoke();
4570 >        public ConcurrentHashMapSpliterator<V> spliterator() {
4571 >            Node<K,V>[] t;
4572 >            ConcurrentHashMapV8<K,V> m = map;
4573 >            long n = m.sumCount();
4574 >            int f = (t = m.table) == null ? 0 : t.length;
4575 >            return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4576          }
4577  
4578 <        /**
4579 <         * Returns the result of accumulating the given transformation
4580 <         * of all values using the given reducer to combine values,
4581 <         * and the given basis as an identity value.
4582 <         *
4583 <         * @param transformer a function returning the transformation
4584 <         * for an element
4585 <         * @param basis the identity (initial default value) for the reduction
4438 <         * @param reducer a commutative associative combining function
4439 <         * @return the result of accumulating the given transformation
4440 <         * of all values
4441 <         */
4442 <        public int reduceToInt(ObjectToInt<? super V> transformer,
4443 <                               int basis,
4444 <                               IntByIntToInt reducer) {
4445 <            return ForkJoinTasks.reduceValuesToInt
4446 <                (map, transformer, basis, reducer).invoke();
4578 >        public void forEach(Action<? super V> action) {
4579 >            if (action == null) throw new NullPointerException();
4580 >            Node<K,V>[] t;
4581 >            if ((t = map.table) != null) {
4582 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4583 >                for (Node<K,V> p; (p = it.advance()) != null; )
4584 >                    action.apply(p.val);
4585 >            }
4586          }
4448
4587      }
4588  
4589      /**
4590       * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value)
4591       * entries.  This class cannot be directly instantiated. See
4592 <     * {@link #entrySet}.
4592 >     * {@link #entrySet()}.
4593       */
4594 <    public static final class EntrySetView<K,V> extends CHMView<K,V>
4595 <        implements Set<Map.Entry<K,V>> {
4596 <        EntrySetView(ConcurrentHashMapV8<K, V> map) { super(map); }
4597 <        public final boolean contains(Object o) {
4594 >    static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4595 >        implements Set<Map.Entry<K,V>>, java.io.Serializable {
4596 >        private static final long serialVersionUID = 2249069246763182397L;
4597 >        EntrySetView(ConcurrentHashMapV8<K,V> map) { super(map); }
4598 >
4599 >        public boolean contains(Object o) {
4600              Object k, v, r; Map.Entry<?,?> e;
4601              return ((o instanceof Map.Entry) &&
4602                      (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
# Line 4464 | Line 4604 | public class ConcurrentHashMapV8<K, V>
4604                      (v = e.getValue()) != null &&
4605                      (v == r || v.equals(r)));
4606          }
4607 <        public final boolean remove(Object o) {
4607 >
4608 >        public boolean remove(Object o) {
4609              Object k, v; Map.Entry<?,?> e;
4610              return ((o instanceof Map.Entry) &&
4611                      (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
# Line 4473 | Line 4614 | public class ConcurrentHashMapV8<K, V>
4614          }
4615  
4616          /**
4617 <         * Returns a "weakly consistent" iterator that will never
4477 <         * throw {@link ConcurrentModificationException}, and
4478 <         * guarantees to traverse elements as they existed upon
4479 <         * construction of the iterator, and may (but is not
4480 <         * guaranteed to) reflect any modifications subsequent to
4481 <         * construction.
4482 <         *
4483 <         * @return an iterator over the entries of this map
4617 >         * @return an iterator over the entries of the backing map
4618           */
4619 <        public final Iterator<Map.Entry<K,V>> iterator() {
4620 <            return new EntryIterator<K,V>(map);
4619 >        public Iterator<Map.Entry<K,V>> iterator() {
4620 >            ConcurrentHashMapV8<K,V> m = map;
4621 >            Node<K,V>[] t;
4622 >            int f = (t = m.table) == null ? 0 : t.length;
4623 >            return new EntryIterator<K,V>(t, f, 0, f, m);
4624          }
4625  
4626 <        public final boolean add(Entry<K,V> e) {
4627 <            K key = e.getKey();
4491 <            V value = e.getValue();
4492 <            if (key == null || value == null)
4493 <                throw new NullPointerException();
4494 <            return map.internalPut(key, value) == null;
4626 >        public boolean add(Entry<K,V> e) {
4627 >            return map.putVal(e.getKey(), e.getValue(), false) == null;
4628          }
4629 <        public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4629 >
4630 >        public boolean addAll(Collection<? extends Entry<K,V>> c) {
4631              boolean added = false;
4632              for (Entry<K,V> e : c) {
4633                  if (add(e))
# Line 4501 | Line 4635 | public class ConcurrentHashMapV8<K, V>
4635              }
4636              return added;
4637          }
4638 <        public boolean equals(Object o) {
4638 >
4639 >        public final int hashCode() {
4640 >            int h = 0;
4641 >            Node<K,V>[] t;
4642 >            if ((t = map.table) != null) {
4643 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4644 >                for (Node<K,V> p; (p = it.advance()) != null; ) {
4645 >                    h += p.hashCode();
4646 >                }
4647 >            }
4648 >            return h;
4649 >        }
4650 >
4651 >        public final boolean equals(Object o) {
4652              Set<?> c;
4653              return ((o instanceof Set) &&
4654                      ((c = (Set<?>)o) == this ||
4655                       (containsAll(c) && c.containsAll(this))));
4656          }
4657  
4658 <        /**
4659 <         * Performs the given action for each entry.
4660 <         *
4661 <         * @param action the action
4662 <         */
4663 <        public void forEach(Action<Map.Entry<K,V>> action) {
4517 <            ForkJoinTasks.forEachEntry
4518 <                (map, action).invoke();
4519 <        }
4520 <
4521 <        /**
4522 <         * Performs the given action for each non-null transformation
4523 <         * of each entry.
4524 <         *
4525 <         * @param transformer a function returning the transformation
4526 <         * for an element, or null of there is no transformation (in
4527 <         * which case the action is not applied).
4528 <         * @param action the action
4529 <         */
4530 <        public <U> void forEach(Fun<Map.Entry<K,V>, ? extends U> transformer,
4531 <                                Action<U> action) {
4532 <            ForkJoinTasks.forEachEntry
4533 <                (map, transformer, action).invoke();
4534 <        }
4535 <
4536 <        /**
4537 <         * Returns a non-null result from applying the given search
4538 <         * function on each entry, or null if none.  Upon success,
4539 <         * further element processing is suppressed and the results of
4540 <         * any other parallel invocations of the search function are
4541 <         * ignored.
4542 <         *
4543 <         * @param searchFunction a function returning a non-null
4544 <         * result on success, else null
4545 <         * @return a non-null result from applying the given search
4546 <         * function on each entry, or null if none
4547 <         */
4548 <        public <U> U search(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4549 <            return ForkJoinTasks.searchEntries
4550 <                (map, searchFunction).invoke();
4551 <        }
4552 <
4553 <        /**
4554 <         * Returns the result of accumulating all entries using the
4555 <         * given reducer to combine values, or null if none.
4556 <         *
4557 <         * @param reducer a commutative associative combining function
4558 <         * @return the result of accumulating all entries
4559 <         */
4560 <        public Map.Entry<K,V> reduce(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4561 <            return ForkJoinTasks.reduceEntries
4562 <                (map, reducer).invoke();
4563 <        }
4564 <
4565 <        /**
4566 <         * Returns the result of accumulating the given transformation
4567 <         * of all entries using the given reducer to combine values,
4568 <         * or null if none.
4569 <         *
4570 <         * @param transformer a function returning the transformation
4571 <         * for an element, or null of there is no transformation (in
4572 <         * which case it is not combined).
4573 <         * @param reducer a commutative associative combining function
4574 <         * @return the result of accumulating the given transformation
4575 <         * of all entries
4576 <         */
4577 <        public <U> U reduce(Fun<Map.Entry<K,V>, ? extends U> transformer,
4578 <                            BiFun<? super U, ? super U, ? extends U> reducer) {
4579 <            return ForkJoinTasks.reduceEntries
4580 <                (map, transformer, reducer).invoke();
4581 <        }
4582 <
4583 <        /**
4584 <         * Returns the result of accumulating the given transformation
4585 <         * of all entries using the given reducer to combine values,
4586 <         * and the given basis as an identity value.
4587 <         *
4588 <         * @param transformer a function returning the transformation
4589 <         * for an element
4590 <         * @param basis the identity (initial default value) for the reduction
4591 <         * @param reducer a commutative associative combining function
4592 <         * @return the result of accumulating the given transformation
4593 <         * of all entries
4594 <         */
4595 <        public double reduceToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
4596 <                                     double basis,
4597 <                                     DoubleByDoubleToDouble reducer) {
4598 <            return ForkJoinTasks.reduceEntriesToDouble
4599 <                (map, transformer, basis, reducer).invoke();
4600 <        }
4601 <
4602 <        /**
4603 <         * Returns the result of accumulating the given transformation
4604 <         * of all entries using the given reducer to combine values,
4605 <         * and the given basis as an identity value.
4606 <         *
4607 <         * @param transformer a function returning the transformation
4608 <         * for an element
4609 <         * @param basis the identity (initial default value) for the reduction
4610 <         * @param reducer a commutative associative combining function
4611 <         * @return  the result of accumulating the given transformation
4612 <         * of all entries
4613 <         */
4614 <        public long reduceToLong(ObjectToLong<Map.Entry<K,V>> transformer,
4615 <                                 long basis,
4616 <                                 LongByLongToLong reducer) {
4617 <            return ForkJoinTasks.reduceEntriesToLong
4618 <                (map, transformer, basis, reducer).invoke();
4619 <        }
4620 <
4621 <        /**
4622 <         * Returns the result of accumulating the given transformation
4623 <         * of all entries using the given reducer to combine values,
4624 <         * and the given basis as an identity value.
4625 <         *
4626 <         * @param transformer a function returning the transformation
4627 <         * for an element
4628 <         * @param basis the identity (initial default value) for the reduction
4629 <         * @param reducer a commutative associative combining function
4630 <         * @return the result of accumulating the given transformation
4631 <         * of all entries
4632 <         */
4633 <        public int reduceToInt(ObjectToInt<Map.Entry<K,V>> transformer,
4634 <                               int basis,
4635 <                               IntByIntToInt reducer) {
4636 <            return ForkJoinTasks.reduceEntriesToInt
4637 <                (map, transformer, basis, reducer).invoke();
4658 >        public ConcurrentHashMapSpliterator<Map.Entry<K,V>> spliterator() {
4659 >            Node<K,V>[] t;
4660 >            ConcurrentHashMapV8<K,V> m = map;
4661 >            long n = m.sumCount();
4662 >            int f = (t = m.table) == null ? 0 : t.length;
4663 >            return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4664          }
4665  
4666 <    }
4641 <
4642 <    // ---------------------------------------------------------------------
4643 <
4644 <    /**
4645 <     * Predefined tasks for performing bulk parallel operations on
4646 <     * ConcurrentHashMapV8s. These tasks follow the forms and rules used
4647 <     * for bulk operations. Each method has the same name, but returns
4648 <     * a task rather than invoking it. These methods may be useful in
4649 <     * custom applications such as submitting a task without waiting
4650 <     * for completion, using a custom pool, or combining with other
4651 <     * tasks.
4652 <     */
4653 <    public static class ForkJoinTasks {
4654 <        private ForkJoinTasks() {}
4655 <
4656 <        /**
4657 <         * Returns a task that when invoked, performs the given
4658 <         * action for each (key, value)
4659 <         *
4660 <         * @param map the map
4661 <         * @param action the action
4662 <         * @return the task
4663 <         */
4664 <        public static <K,V> ForkJoinTask<Void> forEach
4665 <            (ConcurrentHashMapV8<K,V> map,
4666 <             BiAction<K,V> action) {
4666 >        public void forEach(Action<? super Map.Entry<K,V>> action) {
4667              if (action == null) throw new NullPointerException();
4668 <            return new ForEachMappingTask<K,V>(map, null, -1, null, action);
4669 <        }
4670 <
4671 <        /**
4672 <         * Returns a task that when invoked, performs the given
4673 <         * action for each non-null transformation of each (key, value)
4674 <         *
4675 <         * @param map the map
4676 <         * @param transformer a function returning the transformation
4677 <         * for an element, or null if there is no transformation (in
4678 <         * which case the action is not applied)
4679 <         * @param action the action
4680 <         * @return the task
4681 <         */
4682 <        public static <K,V,U> ForkJoinTask<Void> forEach
4683 <            (ConcurrentHashMapV8<K,V> map,
4684 <             BiFun<? super K, ? super V, ? extends U> transformer,
4685 <             Action<U> action) {
4686 <            if (transformer == null || action == null)
4687 <                throw new NullPointerException();
4688 <            return new ForEachTransformedMappingTask<K,V,U>
4689 <                (map, null, -1, null, transformer, action);
4690 <        }
4691 <
4692 <        /**
4693 <         * Returns a task that when invoked, returns a non-null result
4694 <         * from applying the given search function on each (key,
4695 <         * value), or null if none. Upon success, further element
4696 <         * processing is suppressed and the results of any other
4697 <         * parallel invocations of the search function are ignored.
4698 <         *
4699 <         * @param map the map
4700 <         * @param searchFunction a function returning a non-null
4701 <         * result on success, else null
4702 <         * @return the task
4703 <         */
4704 <        public static <K,V,U> ForkJoinTask<U> search
4705 <            (ConcurrentHashMapV8<K,V> map,
4706 <             BiFun<? super K, ? super V, ? extends U> searchFunction) {
4707 <            if (searchFunction == null) throw new NullPointerException();
4708 <            return new SearchMappingsTask<K,V,U>
4709 <                (map, null, -1, null, searchFunction,
4710 <                 new AtomicReference<U>());
4711 <        }
4712 <
4713 <        /**
4714 <         * Returns a task that when invoked, returns the result of
4715 <         * accumulating the given transformation of all (key, value) pairs
4716 <         * using the given reducer to combine values, or null if none.
4717 <         *
4718 <         * @param map the map
4719 <         * @param transformer a function returning the transformation
4720 <         * for an element, or null if there is no transformation (in
4721 <         * which case it is not combined).
4722 <         * @param reducer a commutative associative combining function
4723 <         * @return the task
4724 <         */
4725 <        public static <K,V,U> ForkJoinTask<U> reduce
4726 <            (ConcurrentHashMapV8<K,V> map,
4727 <             BiFun<? super K, ? super V, ? extends U> transformer,
4728 <             BiFun<? super U, ? super U, ? extends U> reducer) {
4729 <            if (transformer == null || reducer == null)
4730 <                throw new NullPointerException();
4731 <            return new MapReduceMappingsTask<K,V,U>
4732 <                (map, null, -1, null, transformer, reducer);
4733 <        }
4734 <
4735 <        /**
4736 <         * Returns a task that when invoked, returns the result of
4737 <         * accumulating the given transformation of all (key, value) pairs
4738 <         * using the given reducer to combine values, and the given
4739 <         * basis as an identity value.
4740 <         *
4741 <         * @param map the map
4742 <         * @param transformer a function returning the transformation
4743 <         * for an element
4744 <         * @param basis the identity (initial default value) for the reduction
4745 <         * @param reducer a commutative associative combining function
4746 <         * @return the task
4747 <         */
4748 <        public static <K,V> ForkJoinTask<Double> reduceToDouble
4749 <            (ConcurrentHashMapV8<K,V> map,
4750 <             ObjectByObjectToDouble<? super K, ? super V> transformer,
4751 <             double basis,
4752 <             DoubleByDoubleToDouble reducer) {
4753 <            if (transformer == null || reducer == null)
4754 <                throw new NullPointerException();
4755 <            return new MapReduceMappingsToDoubleTask<K,V>
4756 <                (map, null, -1, null, transformer, basis, reducer);
4757 <        }
4758 <
4759 <        /**
4760 <         * Returns a task that when invoked, returns the result of
4761 <         * accumulating the given transformation of all (key, value) pairs
4762 <         * using the given reducer to combine values, and the given
4763 <         * basis as an identity value.
4764 <         *
4765 <         * @param map the map
4766 <         * @param transformer a function returning the transformation
4767 <         * for an element
4768 <         * @param basis the identity (initial default value) for the reduction
4769 <         * @param reducer a commutative associative combining function
4770 <         * @return the task
4771 <         */
4772 <        public static <K,V> ForkJoinTask<Long> reduceToLong
4773 <            (ConcurrentHashMapV8<K,V> map,
4774 <             ObjectByObjectToLong<? super K, ? super V> transformer,
4775 <             long basis,
4776 <             LongByLongToLong reducer) {
4777 <            if (transformer == null || reducer == null)
4778 <                throw new NullPointerException();
4779 <            return new MapReduceMappingsToLongTask<K,V>
4780 <                (map, null, -1, null, transformer, basis, reducer);
4781 <        }
4782 <
4783 <        /**
4784 <         * Returns a task that when invoked, returns the result of
4785 <         * accumulating the given transformation of all (key, value) pairs
4786 <         * using the given reducer to combine values, and the given
4787 <         * basis as an identity value.
4788 <         *
4789 <         * @param transformer a function returning the transformation
4790 <         * for an element
4791 <         * @param basis the identity (initial default value) for the reduction
4792 <         * @param reducer a commutative associative combining function
4793 <         * @return the task
4794 <         */
4795 <        public static <K,V> ForkJoinTask<Integer> reduceToInt
4796 <            (ConcurrentHashMapV8<K,V> map,
4797 <             ObjectByObjectToInt<? super K, ? super V> transformer,
4798 <             int basis,
4799 <             IntByIntToInt reducer) {
4800 <            if (transformer == null || reducer == null)
4801 <                throw new NullPointerException();
4802 <            return new MapReduceMappingsToIntTask<K,V>
4803 <                (map, null, -1, null, transformer, basis, reducer);
4804 <        }
4805 <
4806 <        /**
4807 <         * Returns a task that when invoked, performs the given action
4808 <         * for each key.
4809 <         *
4810 <         * @param map the map
4811 <         * @param action the action
4812 <         * @return the task
4813 <         */
4814 <        public static <K,V> ForkJoinTask<Void> forEachKey
4815 <            (ConcurrentHashMapV8<K,V> map,
4816 <             Action<K> action) {
4817 <            if (action == null) throw new NullPointerException();
4818 <            return new ForEachKeyTask<K,V>(map, null, -1, null, action);
4819 <        }
4820 <
4821 <        /**
4822 <         * Returns a task that when invoked, performs the given action
4823 <         * for each non-null transformation of each key.
4824 <         *
4825 <         * @param map the map
4826 <         * @param transformer a function returning the transformation
4827 <         * for an element, or null if there is no transformation (in
4828 <         * which case the action is not applied)
4829 <         * @param action the action
4830 <         * @return the task
4831 <         */
4832 <        public static <K,V,U> ForkJoinTask<Void> forEachKey
4833 <            (ConcurrentHashMapV8<K,V> map,
4834 <             Fun<? super K, ? extends U> transformer,
4835 <             Action<U> action) {
4836 <            if (transformer == null || action == null)
4837 <                throw new NullPointerException();
4838 <            return new ForEachTransformedKeyTask<K,V,U>
4839 <                (map, null, -1, null, transformer, action);
4840 <        }
4841 <
4842 <        /**
4843 <         * Returns a task that when invoked, returns a non-null result
4844 <         * from applying the given search function on each key, or
4845 <         * null if none.  Upon success, further element processing is
4846 <         * suppressed and the results of any other parallel
4847 <         * invocations of the search function are ignored.
4848 <         *
4849 <         * @param map the map
4850 <         * @param searchFunction a function returning a non-null
4851 <         * result on success, else null
4852 <         * @return the task
4853 <         */
4854 <        public static <K,V,U> ForkJoinTask<U> searchKeys
4855 <            (ConcurrentHashMapV8<K,V> map,
4856 <             Fun<? super K, ? extends U> searchFunction) {
4857 <            if (searchFunction == null) throw new NullPointerException();
4858 <            return new SearchKeysTask<K,V,U>
4859 <                (map, null, -1, null, searchFunction,
4860 <                 new AtomicReference<U>());
4861 <        }
4862 <
4863 <        /**
4864 <         * Returns a task that when invoked, returns the result of
4865 <         * accumulating all keys using the given reducer to combine
4866 <         * values, or null if none.
4867 <         *
4868 <         * @param map the map
4869 <         * @param reducer a commutative associative combining function
4870 <         * @return the task
4871 <         */
4872 <        public static <K,V> ForkJoinTask<K> reduceKeys
4873 <            (ConcurrentHashMapV8<K,V> map,
4874 <             BiFun<? super K, ? super K, ? extends K> reducer) {
4875 <            if (reducer == null) throw new NullPointerException();
4876 <            return new ReduceKeysTask<K,V>
4877 <                (map, null, -1, null, reducer);
4878 <        }
4879 <
4880 <        /**
4881 <         * Returns a task that when invoked, returns the result of
4882 <         * accumulating the given transformation of all keys using the given
4883 <         * reducer to combine values, or null if none.
4884 <         *
4885 <         * @param map the map
4886 <         * @param transformer a function returning the transformation
4887 <         * for an element, or null if there is no transformation (in
4888 <         * which case it is not combined).
4889 <         * @param reducer a commutative associative combining function
4890 <         * @return the task
4891 <         */
4892 <        public static <K,V,U> ForkJoinTask<U> reduceKeys
4893 <            (ConcurrentHashMapV8<K,V> map,
4894 <             Fun<? super K, ? extends U> transformer,
4895 <             BiFun<? super U, ? super U, ? extends U> reducer) {
4896 <            if (transformer == null || reducer == null)
4897 <                throw new NullPointerException();
4898 <            return new MapReduceKeysTask<K,V,U>
4899 <                (map, null, -1, null, transformer, reducer);
4900 <        }
4901 <
4902 <        /**
4903 <         * Returns a task that when invoked, returns the result of
4904 <         * accumulating the given transformation of all keys using the given
4905 <         * reducer to combine values, and the given basis as an
4906 <         * identity value.
4907 <         *
4908 <         * @param map the map
4909 <         * @param transformer a function returning the transformation
4910 <         * for an element
4911 <         * @param basis the identity (initial default value) for the reduction
4912 <         * @param reducer a commutative associative combining function
4913 <         * @return the task
4914 <         */
4915 <        public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
4916 <            (ConcurrentHashMapV8<K,V> map,
4917 <             ObjectToDouble<? super K> transformer,
4918 <             double basis,
4919 <             DoubleByDoubleToDouble reducer) {
4920 <            if (transformer == null || reducer == null)
4921 <                throw new NullPointerException();
4922 <            return new MapReduceKeysToDoubleTask<K,V>
4923 <                (map, null, -1, null, transformer, basis, reducer);
4924 <        }
4925 <
4926 <        /**
4927 <         * Returns a task that when invoked, returns the result of
4928 <         * accumulating the given transformation of all keys using the given
4929 <         * reducer to combine values, and the given basis as an
4930 <         * identity value.
4931 <         *
4932 <         * @param map the map
4933 <         * @param transformer a function returning the transformation
4934 <         * for an element
4935 <         * @param basis the identity (initial default value) for the reduction
4936 <         * @param reducer a commutative associative combining function
4937 <         * @return the task
4938 <         */
4939 <        public static <K,V> ForkJoinTask<Long> reduceKeysToLong
4940 <            (ConcurrentHashMapV8<K,V> map,
4941 <             ObjectToLong<? super K> transformer,
4942 <             long basis,
4943 <             LongByLongToLong reducer) {
4944 <            if (transformer == null || reducer == null)
4945 <                throw new NullPointerException();
4946 <            return new MapReduceKeysToLongTask<K,V>
4947 <                (map, null, -1, null, transformer, basis, reducer);
4948 <        }
4949 <
4950 <        /**
4951 <         * Returns a task that when invoked, returns the result of
4952 <         * accumulating the given transformation of all keys using the given
4953 <         * reducer to combine values, and the given basis as an
4954 <         * identity value.
4955 <         *
4956 <         * @param map the map
4957 <         * @param transformer a function returning the transformation
4958 <         * for an element
4959 <         * @param basis the identity (initial default value) for the reduction
4960 <         * @param reducer a commutative associative combining function
4961 <         * @return the task
4962 <         */
4963 <        public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
4964 <            (ConcurrentHashMapV8<K,V> map,
4965 <             ObjectToInt<? super K> transformer,
4966 <             int basis,
4967 <             IntByIntToInt reducer) {
4968 <            if (transformer == null || reducer == null)
4969 <                throw new NullPointerException();
4970 <            return new MapReduceKeysToIntTask<K,V>
4971 <                (map, null, -1, null, transformer, basis, reducer);
4972 <        }
4973 <
4974 <        /**
4975 <         * Returns a task that when invoked, performs the given action
4976 <         * for each value.
4977 <         *
4978 <         * @param map the map
4979 <         * @param action the action
4980 <         */
4981 <        public static <K,V> ForkJoinTask<Void> forEachValue
4982 <            (ConcurrentHashMapV8<K,V> map,
4983 <             Action<V> action) {
4984 <            if (action == null) throw new NullPointerException();
4985 <            return new ForEachValueTask<K,V>(map, null, -1, null, action);
4986 <        }
4987 <
4988 <        /**
4989 <         * Returns a task that when invoked, performs the given action
4990 <         * for each non-null transformation of each value.
4991 <         *
4992 <         * @param map the map
4993 <         * @param transformer a function returning the transformation
4994 <         * for an element, or null if there is no transformation (in
4995 <         * which case the action is not applied)
4996 <         * @param action the action
4997 <         */
4998 <        public static <K,V,U> ForkJoinTask<Void> forEachValue
4999 <            (ConcurrentHashMapV8<K,V> map,
5000 <             Fun<? super V, ? extends U> transformer,
5001 <             Action<U> action) {
5002 <            if (transformer == null || action == null)
5003 <                throw new NullPointerException();
5004 <            return new ForEachTransformedValueTask<K,V,U>
5005 <                (map, null, -1, null, transformer, action);
5006 <        }
5007 <
5008 <        /**
5009 <         * Returns a task that when invoked, returns a non-null result
5010 <         * from applying the given search function on each value, or
5011 <         * null if none.  Upon success, further element processing is
5012 <         * suppressed and the results of any other parallel
5013 <         * invocations of the search function are ignored.
5014 <         *
5015 <         * @param map the map
5016 <         * @param searchFunction a function returning a non-null
5017 <         * result on success, else null
5018 <         * @return the task
5019 <         */
5020 <        public static <K,V,U> ForkJoinTask<U> searchValues
5021 <            (ConcurrentHashMapV8<K,V> map,
5022 <             Fun<? super V, ? extends U> searchFunction) {
5023 <            if (searchFunction == null) throw new NullPointerException();
5024 <            return new SearchValuesTask<K,V,U>
5025 <                (map, null, -1, null, searchFunction,
5026 <                 new AtomicReference<U>());
5027 <        }
5028 <
5029 <        /**
5030 <         * Returns a task that when invoked, returns the result of
5031 <         * accumulating all values using the given reducer to combine
5032 <         * values, or null if none.
5033 <         *
5034 <         * @param map the map
5035 <         * @param reducer a commutative associative combining function
5036 <         * @return the task
5037 <         */
5038 <        public static <K,V> ForkJoinTask<V> reduceValues
5039 <            (ConcurrentHashMapV8<K,V> map,
5040 <             BiFun<? super V, ? super V, ? extends V> reducer) {
5041 <            if (reducer == null) throw new NullPointerException();
5042 <            return new ReduceValuesTask<K,V>
5043 <                (map, null, -1, null, reducer);
5044 <        }
5045 <
5046 <        /**
5047 <         * Returns a task that when invoked, returns the result of
5048 <         * accumulating the given transformation of all values using the
5049 <         * given reducer to combine values, or null if none.
5050 <         *
5051 <         * @param map the map
5052 <         * @param transformer a function returning the transformation
5053 <         * for an element, or null if there is no transformation (in
5054 <         * which case it is not combined).
5055 <         * @param reducer a commutative associative combining function
5056 <         * @return the task
5057 <         */
5058 <        public static <K,V,U> ForkJoinTask<U> reduceValues
5059 <            (ConcurrentHashMapV8<K,V> map,
5060 <             Fun<? super V, ? extends U> transformer,
5061 <             BiFun<? super U, ? super U, ? extends U> reducer) {
5062 <            if (transformer == null || reducer == null)
5063 <                throw new NullPointerException();
5064 <            return new MapReduceValuesTask<K,V,U>
5065 <                (map, null, -1, null, transformer, reducer);
5066 <        }
5067 <
5068 <        /**
5069 <         * Returns a task that when invoked, returns the result of
5070 <         * accumulating the given transformation of all values using the
5071 <         * given reducer to combine values, and the given basis as an
5072 <         * identity value.
5073 <         *
5074 <         * @param map the map
5075 <         * @param transformer a function returning the transformation
5076 <         * for an element
5077 <         * @param basis the identity (initial default value) for the reduction
5078 <         * @param reducer a commutative associative combining function
5079 <         * @return the task
5080 <         */
5081 <        public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5082 <            (ConcurrentHashMapV8<K,V> map,
5083 <             ObjectToDouble<? super V> transformer,
5084 <             double basis,
5085 <             DoubleByDoubleToDouble reducer) {
5086 <            if (transformer == null || reducer == null)
5087 <                throw new NullPointerException();
5088 <            return new MapReduceValuesToDoubleTask<K,V>
5089 <                (map, null, -1, null, transformer, basis, reducer);
5090 <        }
5091 <
5092 <        /**
5093 <         * Returns a task that when invoked, returns the result of
5094 <         * accumulating the given transformation of all values using the
5095 <         * given reducer to combine values, and the given basis as an
5096 <         * identity value.
5097 <         *
5098 <         * @param map the map
5099 <         * @param transformer a function returning the transformation
5100 <         * for an element
5101 <         * @param basis the identity (initial default value) for the reduction
5102 <         * @param reducer a commutative associative combining function
5103 <         * @return the task
5104 <         */
5105 <        public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5106 <            (ConcurrentHashMapV8<K,V> map,
5107 <             ObjectToLong<? super V> transformer,
5108 <             long basis,
5109 <             LongByLongToLong reducer) {
5110 <            if (transformer == null || reducer == null)
5111 <                throw new NullPointerException();
5112 <            return new MapReduceValuesToLongTask<K,V>
5113 <                (map, null, -1, null, transformer, basis, reducer);
5114 <        }
5115 <
5116 <        /**
5117 <         * Returns a task that when invoked, returns the result of
5118 <         * accumulating the given transformation of all values using the
5119 <         * given reducer to combine values, and the given basis as an
5120 <         * identity value.
5121 <         *
5122 <         * @param map the map
5123 <         * @param transformer a function returning the transformation
5124 <         * for an element
5125 <         * @param basis the identity (initial default value) for the reduction
5126 <         * @param reducer a commutative associative combining function
5127 <         * @return the task
5128 <         */
5129 <        public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5130 <            (ConcurrentHashMapV8<K,V> map,
5131 <             ObjectToInt<? super V> transformer,
5132 <             int basis,
5133 <             IntByIntToInt reducer) {
5134 <            if (transformer == null || reducer == null)
5135 <                throw new NullPointerException();
5136 <            return new MapReduceValuesToIntTask<K,V>
5137 <                (map, null, -1, null, transformer, basis, reducer);
5138 <        }
5139 <
5140 <        /**
5141 <         * Returns a task that when invoked, perform the given action
5142 <         * for each entry.
5143 <         *
5144 <         * @param map the map
5145 <         * @param action the action
5146 <         */
5147 <        public static <K,V> ForkJoinTask<Void> forEachEntry
5148 <            (ConcurrentHashMapV8<K,V> map,
5149 <             Action<Map.Entry<K,V>> action) {
5150 <            if (action == null) throw new NullPointerException();
5151 <            return new ForEachEntryTask<K,V>(map, null, -1, null, action);
5152 <        }
5153 <
5154 <        /**
5155 <         * Returns a task that when invoked, perform the given action
5156 <         * for each non-null transformation of each entry.
5157 <         *
5158 <         * @param map the map
5159 <         * @param transformer a function returning the transformation
5160 <         * for an element, or null if there is no transformation (in
5161 <         * which case the action is not applied)
5162 <         * @param action the action
5163 <         */
5164 <        public static <K,V,U> ForkJoinTask<Void> forEachEntry
5165 <            (ConcurrentHashMapV8<K,V> map,
5166 <             Fun<Map.Entry<K,V>, ? extends U> transformer,
5167 <             Action<U> action) {
5168 <            if (transformer == null || action == null)
5169 <                throw new NullPointerException();
5170 <            return new ForEachTransformedEntryTask<K,V,U>
5171 <                (map, null, -1, null, transformer, action);
5172 <        }
5173 <
5174 <        /**
5175 <         * Returns a task that when invoked, returns a non-null result
5176 <         * from applying the given search function on each entry, or
5177 <         * null if none.  Upon success, further element processing is
5178 <         * suppressed and the results of any other parallel
5179 <         * invocations of the search function are ignored.
5180 <         *
5181 <         * @param map the map
5182 <         * @param searchFunction a function returning a non-null
5183 <         * result on success, else null
5184 <         * @return the task
5185 <         */
5186 <        public static <K,V,U> ForkJoinTask<U> searchEntries
5187 <            (ConcurrentHashMapV8<K,V> map,
5188 <             Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
5189 <            if (searchFunction == null) throw new NullPointerException();
5190 <            return new SearchEntriesTask<K,V,U>
5191 <                (map, null, -1, null, searchFunction,
5192 <                 new AtomicReference<U>());
5193 <        }
5194 <
5195 <        /**
5196 <         * Returns a task that when invoked, returns the result of
5197 <         * accumulating all entries using the given reducer to combine
5198 <         * values, or null if none.
5199 <         *
5200 <         * @param map the map
5201 <         * @param reducer a commutative associative combining function
5202 <         * @return the task
5203 <         */
5204 <        public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5205 <            (ConcurrentHashMapV8<K,V> map,
5206 <             BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5207 <            if (reducer == null) throw new NullPointerException();
5208 <            return new ReduceEntriesTask<K,V>
5209 <                (map, null, -1, null, reducer);
5210 <        }
5211 <
5212 <        /**
5213 <         * Returns a task that when invoked, returns the result of
5214 <         * accumulating the given transformation of all entries using the
5215 <         * given reducer to combine values, or null if none.
5216 <         *
5217 <         * @param map the map
5218 <         * @param transformer a function returning the transformation
5219 <         * for an element, or null if there is no transformation (in
5220 <         * which case it is not combined).
5221 <         * @param reducer a commutative associative combining function
5222 <         * @return the task
5223 <         */
5224 <        public static <K,V,U> ForkJoinTask<U> reduceEntries
5225 <            (ConcurrentHashMapV8<K,V> map,
5226 <             Fun<Map.Entry<K,V>, ? extends U> transformer,
5227 <             BiFun<? super U, ? super U, ? extends U> reducer) {
5228 <            if (transformer == null || reducer == null)
5229 <                throw new NullPointerException();
5230 <            return new MapReduceEntriesTask<K,V,U>
5231 <                (map, null, -1, null, transformer, reducer);
5232 <        }
5233 <
5234 <        /**
5235 <         * Returns a task that when invoked, returns the result of
5236 <         * accumulating the given transformation of all entries using the
5237 <         * given reducer to combine values, and the given basis as an
5238 <         * identity value.
5239 <         *
5240 <         * @param map the map
5241 <         * @param transformer a function returning the transformation
5242 <         * for an element
5243 <         * @param basis the identity (initial default value) for the reduction
5244 <         * @param reducer a commutative associative combining function
5245 <         * @return the task
5246 <         */
5247 <        public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5248 <            (ConcurrentHashMapV8<K,V> map,
5249 <             ObjectToDouble<Map.Entry<K,V>> transformer,
5250 <             double basis,
5251 <             DoubleByDoubleToDouble reducer) {
5252 <            if (transformer == null || reducer == null)
5253 <                throw new NullPointerException();
5254 <            return new MapReduceEntriesToDoubleTask<K,V>
5255 <                (map, null, -1, null, transformer, basis, reducer);
5256 <        }
5257 <
5258 <        /**
5259 <         * Returns a task that when invoked, returns the result of
5260 <         * accumulating the given transformation of all entries using the
5261 <         * given reducer to combine values, and the given basis as an
5262 <         * identity value.
5263 <         *
5264 <         * @param map the map
5265 <         * @param transformer a function returning the transformation
5266 <         * for an element
5267 <         * @param basis the identity (initial default value) for the reduction
5268 <         * @param reducer a commutative associative combining function
5269 <         * @return the task
5270 <         */
5271 <        public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5272 <            (ConcurrentHashMapV8<K,V> map,
5273 <             ObjectToLong<Map.Entry<K,V>> transformer,
5274 <             long basis,
5275 <             LongByLongToLong reducer) {
5276 <            if (transformer == null || reducer == null)
5277 <                throw new NullPointerException();
5278 <            return new MapReduceEntriesToLongTask<K,V>
5279 <                (map, null, -1, null, transformer, basis, reducer);
4668 >            Node<K,V>[] t;
4669 >            if ((t = map.table) != null) {
4670 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4671 >                for (Node<K,V> p; (p = it.advance()) != null; )
4672 >                    action.apply(new MapEntry<K,V>(p.key, p.val, map));
4673 >            }
4674          }
4675  
5282        /**
5283         * Returns a task that when invoked, returns the result of
5284         * accumulating the given transformation of all entries using the
5285         * given reducer to combine values, and the given basis as an
5286         * identity value.
5287         *
5288         * @param map the map
5289         * @param transformer a function returning the transformation
5290         * for an element
5291         * @param basis the identity (initial default value) for the reduction
5292         * @param reducer a commutative associative combining function
5293         * @return the task
5294         */
5295        public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5296            (ConcurrentHashMapV8<K,V> map,
5297             ObjectToInt<Map.Entry<K,V>> transformer,
5298             int basis,
5299             IntByIntToInt reducer) {
5300            if (transformer == null || reducer == null)
5301                throw new NullPointerException();
5302            return new MapReduceEntriesToIntTask<K,V>
5303                (map, null, -1, null, transformer, basis, reducer);
5304        }
4676      }
4677  
4678      // -------------------------------------------------------
4679  
4680      /**
4681 <     * Base for FJ tasks for bulk operations. This adds a variant of
4682 <     * CountedCompleters and some split and merge bookkeeping to
5312 <     * iterator functionality. The forEach and reduce methods are
5313 <     * similar to those illustrated in CountedCompleter documentation,
5314 <     * except that bottom-up reduction completions perform them within
5315 <     * their compute methods. The search methods are like forEach
5316 <     * except they continually poll for success and exit early.  Also,
5317 <     * exceptions are handled in a simpler manner, by just trying to
5318 <     * complete root task exceptionally.
5319 <     */
5320 <    @SuppressWarnings("serial") static abstract class BulkTask<K,V,R> extends Traverser<K,V,R> {
5321 <        final BulkTask<K,V,?> parent;  // completion target
5322 <        int batch;                     // split control; -1 for unknown
5323 <        int pending;                   // completion control
5324 <
5325 <        BulkTask(ConcurrentHashMapV8<K,V> map, BulkTask<K,V,?> parent,
5326 <                 int batch) {
5327 <            super(map);
5328 <            this.parent = parent;
5329 <            this.batch = batch;
5330 <            if (parent != null && map != null) { // split parent
5331 <                Node[] t;
5332 <                if ((t = parent.tab) == null &&
5333 <                    (t = parent.tab = map.table) != null)
5334 <                    parent.baseLimit = parent.baseSize = t.length;
5335 <                this.tab = t;
5336 <                this.baseSize = parent.baseSize;
5337 <                int hi = this.baseLimit = parent.baseLimit;
5338 <                parent.baseLimit = this.index = this.baseIndex =
5339 <                    (hi + parent.baseIndex + 1) >>> 1;
5340 <            }
5341 <        }
5342 <
5343 <        /**
5344 <         * Forces root task to complete.
5345 <         * @param ex if null, complete normally, else exceptionally
5346 <         * @return false to simplify use
5347 <         */
5348 <        final boolean tryCompleteComputation(Throwable ex) {
5349 <            for (BulkTask<K,V,?> a = this;;) {
5350 <                BulkTask<K,V,?> p = a.parent;
5351 <                if (p == null) {
5352 <                    if (ex != null)
5353 <                        a.completeExceptionally(ex);
5354 <                    else
5355 <                        a.quietlyComplete();
5356 <                    return false;
5357 <                }
5358 <                a = p;
5359 <            }
5360 <        }
5361 <
5362 <        /**
5363 <         * Version of tryCompleteComputation for function screening checks
5364 <         */
5365 <        final boolean abortOnNullFunction() {
5366 <            return tryCompleteComputation(new Error("Unexpected null function"));
5367 <        }
5368 <
5369 <        // utilities
5370 <
5371 <        /** CompareAndSet pending count */
5372 <        final boolean casPending(int cmp, int val) {
5373 <            return U.compareAndSwapInt(this, PENDING, cmp, val);
5374 <        }
5375 <
5376 <        /**
5377 <         * Returns approx exp2 of the number of times (minus one) to
5378 <         * split task by two before executing leaf action. This value
5379 <         * is faster to compute and more convenient to use as a guide
5380 <         * to splitting than is the depth, since it is used while
5381 <         * dividing by two anyway.
5382 <         */
5383 <        final int batch() {
5384 <            ConcurrentHashMapV8<K, V> m; int b; Node[] t;  ForkJoinPool pool;
5385 <            if ((b = batch) < 0 && (m = map) != null) { // force initialization
5386 <                if ((t = tab) == null && (t = tab = m.table) != null)
5387 <                    baseLimit = baseSize = t.length;
5388 <                if (t != null) {
5389 <                    long n = m.counter.sum();
5390 <                    int par = ((pool = getPool()) == null) ?
5391 <                        ForkJoinPool.getCommonPoolParallelism() :
5392 <                        pool.getParallelism();
5393 <                    int sp = par << 3; // slack of 8
5394 <                    b = batch = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
5395 <                }
5396 <            }
5397 <            return b;
5398 <        }
5399 <
5400 <        /**
5401 <         * Returns exportable snapshot entry.
5402 <         */
5403 <        static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
5404 <            return new AbstractMap.SimpleEntry<K,V>(k, v);
5405 <        }
5406 <
5407 <        // Unsafe mechanics
5408 <        private static final sun.misc.Unsafe U;
5409 <        private static final long PENDING;
5410 <        static {
5411 <            try {
5412 <                U = getUnsafe();
5413 <                PENDING = U.objectFieldOffset
5414 <                    (BulkTask.class.getDeclaredField("pending"));
5415 <            } catch (Exception e) {
5416 <                throw new Error(e);
5417 <            }
5418 <        }
5419 <    }
5420 <
5421 <    /**
5422 <     * Base class for non-reductive actions
4681 >     * Base class for bulk tasks. Repeats some fields and code from
4682 >     * class Traverser, because we need to subclass CountedCompleter.
4683       */
4684 <    @SuppressWarnings("serial") static abstract class BulkAction<K,V,R> extends BulkTask<K,V,R> {
4685 <        BulkAction<K,V,?> nextTask;
4686 <        BulkAction(ConcurrentHashMapV8<K,V> map, BulkTask<K,V,?> parent,
4687 <                   int batch, BulkAction<K,V,?> nextTask) {
4688 <            super(map, parent, batch);
4689 <            this.nextTask = nextTask;
4684 >    abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4685 >        Node<K,V>[] tab;        // same as Traverser
4686 >        Node<K,V> next;
4687 >        int index;
4688 >        int baseIndex;
4689 >        int baseLimit;
4690 >        final int baseSize;
4691 >        int batch;              // split control
4692 >
4693 >        BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4694 >            super(par);
4695 >            this.batch = b;
4696 >            this.index = this.baseIndex = i;
4697 >            if ((this.tab = t) == null)
4698 >                this.baseSize = this.baseLimit = 0;
4699 >            else if (par == null)
4700 >                this.baseSize = this.baseLimit = t.length;
4701 >            else {
4702 >                this.baseLimit = f;
4703 >                this.baseSize = par.baseSize;
4704 >            }
4705          }
4706  
4707          /**
4708 <         * Try to complete task and upward parents. Upon hitting
5434 <         * non-completed parent, if a non-FJ task, try to help out the
5435 <         * computation.
4708 >         * Same as Traverser version
4709           */
4710 <        final void tryComplete(BulkAction<K,V,?> subtasks) {
4711 <            BulkTask<K,V,?> a = this, s = a;
4712 <            for (int c;;) {
4713 <                if ((c = a.pending) == 0) {
4714 <                    if ((a = (s = a).parent) == null) {
4715 <                        s.quietlyComplete();
4716 <                        break;
4717 <                    }
4718 <                }
4719 <                else if (a.casPending(c, c - 1)) {
4720 <                    if (subtasks != null && !inForkJoinPool()) {
4721 <                        while ((s = a.parent) != null)
4722 <                            a = s;
4723 <                        while (!a.isDone()) {
4724 <                            BulkAction<K,V,?> next = subtasks.nextTask;
4725 <                            if (subtasks.tryUnfork())
5453 <                                subtasks.exec();
5454 <                            if ((subtasks = next) == null)
5455 <                                break;
5456 <                        }
4710 >        final Node<K,V> advance() {
4711 >            Node<K,V> e;
4712 >            if ((e = next) != null)
4713 >                e = e.next;
4714 >            for (;;) {
4715 >                Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4716 >                if (e != null)
4717 >                    return next = e;
4718 >                if (baseIndex >= baseLimit || (t = tab) == null ||
4719 >                    (n = t.length) <= (i = index) || i < 0)
4720 >                    return next = null;
4721 >                if ((e = tabAt(t, index)) != null && e.hash < 0) {
4722 >                    if (e instanceof ForwardingNode) {
4723 >                        tab = ((ForwardingNode<K,V>)e).nextTable;
4724 >                        e = null;
4725 >                        continue;
4726                      }
4727 <                    break;
4727 >                    else if (e instanceof TreeBin)
4728 >                        e = ((TreeBin<K,V>)e).first;
4729 >                    else
4730 >                        e = null;
4731                  }
4732 +                if ((index += baseSize) >= n)
4733 +                    index = ++baseIndex;    // visit upper slots if present
4734              }
4735          }
5462
4736      }
4737  
4738      /*
4739       * Task classes. Coded in a regular but ugly format/style to
4740       * simplify checks that each variant differs in the right way from
4741 <     * others.
4742 <     */
4743 <
4744 <    @SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
4745 <        extends BulkAction<K,V,Void> {
4746 <        final Action<K> action;
4741 >     * others. The null screenings exist because compilers cannot tell
4742 >     * that we've already null-checked task arguments, so we force
4743 >     * simplest hoisted bypass to help avoid convoluted traps.
4744 >     */
4745 >    @SuppressWarnings("serial")
4746 >    static final class ForEachKeyTask<K,V>
4747 >        extends BulkTask<K,V,Void> {
4748 >        final Action<? super K> action;
4749          ForEachKeyTask
4750 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4751 <             ForEachKeyTask<K,V> nextTask,
4752 <             Action<K> action) {
5478 <            super(m, p, b, nextTask);
4750 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4751 >             Action<? super K> action) {
4752 >            super(p, b, i, f, t);
4753              this.action = action;
4754          }
4755 <        @SuppressWarnings("unchecked") public final boolean exec() {
4756 <            final Action<K> action = this.action;
4757 <            if (action == null)
4758 <                return abortOnNullFunction();
4759 <            ForEachKeyTask<K,V> subtasks = null;
4760 <            try {
4761 <                int b = batch(), c;
4762 <                while (b > 1 && baseIndex != baseLimit) {
4763 <                    do {} while (!casPending(c = pending, c+1));
4764 <                    (subtasks = new ForEachKeyTask<K,V>
4765 <                     (map, this, b >>>= 1, subtasks, action)).fork();
4766 <                }
4767 <                while (advance() != null)
5494 <                    action.apply((K)nextKey);
5495 <            } catch (Throwable ex) {
5496 <                return tryCompleteComputation(ex);
4755 >        public final void compute() {
4756 >            final Action<? super K> action;
4757 >            if ((action = this.action) != null) {
4758 >                for (int i = baseIndex, f, h; batch > 0 &&
4759 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4760 >                    addToPendingCount(1);
4761 >                    new ForEachKeyTask<K,V>
4762 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4763 >                         action).fork();
4764 >                }
4765 >                for (Node<K,V> p; (p = advance()) != null;)
4766 >                    action.apply(p.key);
4767 >                propagateCompletion();
4768              }
5498            tryComplete(subtasks);
5499            return false;
4769          }
4770      }
4771  
4772 <    @SuppressWarnings("serial") static final class ForEachValueTask<K,V>
4773 <        extends BulkAction<K,V,Void> {
4774 <        final Action<V> action;
4772 >    @SuppressWarnings("serial")
4773 >    static final class ForEachValueTask<K,V>
4774 >        extends BulkTask<K,V,Void> {
4775 >        final Action<? super V> action;
4776          ForEachValueTask
4777 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4778 <             ForEachValueTask<K,V> nextTask,
4779 <             Action<V> action) {
5510 <            super(m, p, b, nextTask);
4777 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4778 >             Action<? super V> action) {
4779 >            super(p, b, i, f, t);
4780              this.action = action;
4781          }
4782 <        @SuppressWarnings("unchecked") public final boolean exec() {
4783 <            final Action<V> action = this.action;
4784 <            if (action == null)
4785 <                return abortOnNullFunction();
4786 <            ForEachValueTask<K,V> subtasks = null;
4787 <            try {
4788 <                int b = batch(), c;
4789 <                while (b > 1 && baseIndex != baseLimit) {
4790 <                    do {} while (!casPending(c = pending, c+1));
4791 <                    (subtasks = new ForEachValueTask<K,V>
4792 <                     (map, this, b >>>= 1, subtasks, action)).fork();
4793 <                }
4794 <                Object v;
5526 <                while ((v = advance()) != null)
5527 <                    action.apply((V)v);
5528 <            } catch (Throwable ex) {
5529 <                return tryCompleteComputation(ex);
4782 >        public final void compute() {
4783 >            final Action<? super V> action;
4784 >            if ((action = this.action) != null) {
4785 >                for (int i = baseIndex, f, h; batch > 0 &&
4786 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4787 >                    addToPendingCount(1);
4788 >                    new ForEachValueTask<K,V>
4789 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4790 >                         action).fork();
4791 >                }
4792 >                for (Node<K,V> p; (p = advance()) != null;)
4793 >                    action.apply(p.val);
4794 >                propagateCompletion();
4795              }
5531            tryComplete(subtasks);
5532            return false;
4796          }
4797      }
4798  
4799 <    @SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
4800 <        extends BulkAction<K,V,Void> {
4801 <        final Action<Entry<K,V>> action;
4799 >    @SuppressWarnings("serial")
4800 >    static final class ForEachEntryTask<K,V>
4801 >        extends BulkTask<K,V,Void> {
4802 >        final Action<? super Entry<K,V>> action;
4803          ForEachEntryTask
4804 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4805 <             ForEachEntryTask<K,V> nextTask,
4806 <             Action<Entry<K,V>> action) {
5543 <            super(m, p, b, nextTask);
4804 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4805 >             Action<? super Entry<K,V>> action) {
4806 >            super(p, b, i, f, t);
4807              this.action = action;
4808          }
4809 <        @SuppressWarnings("unchecked") public final boolean exec() {
4810 <            final Action<Entry<K,V>> action = this.action;
4811 <            if (action == null)
4812 <                return abortOnNullFunction();
4813 <            ForEachEntryTask<K,V> subtasks = null;
4814 <            try {
4815 <                int b = batch(), c;
4816 <                while (b > 1 && baseIndex != baseLimit) {
4817 <                    do {} while (!casPending(c = pending, c+1));
4818 <                    (subtasks = new ForEachEntryTask<K,V>
4819 <                     (map, this, b >>>= 1, subtasks, action)).fork();
4820 <                }
4821 <                Object v;
5559 <                while ((v = advance()) != null)
5560 <                    action.apply(entryFor((K)nextKey, (V)v));
5561 <            } catch (Throwable ex) {
5562 <                return tryCompleteComputation(ex);
4809 >        public final void compute() {
4810 >            final Action<? super Entry<K,V>> action;
4811 >            if ((action = this.action) != null) {
4812 >                for (int i = baseIndex, f, h; batch > 0 &&
4813 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4814 >                    addToPendingCount(1);
4815 >                    new ForEachEntryTask<K,V>
4816 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4817 >                         action).fork();
4818 >                }
4819 >                for (Node<K,V> p; (p = advance()) != null; )
4820 >                    action.apply(p);
4821 >                propagateCompletion();
4822              }
5564            tryComplete(subtasks);
5565            return false;
4823          }
4824      }
4825  
4826 <    @SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
4827 <        extends BulkAction<K,V,Void> {
4828 <        final BiAction<K,V> action;
4826 >    @SuppressWarnings("serial")
4827 >    static final class ForEachMappingTask<K,V>
4828 >        extends BulkTask<K,V,Void> {
4829 >        final BiAction<? super K, ? super V> action;
4830          ForEachMappingTask
4831 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4832 <             ForEachMappingTask<K,V> nextTask,
4833 <             BiAction<K,V> action) {
5576 <            super(m, p, b, nextTask);
4831 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4832 >             BiAction<? super K,? super V> action) {
4833 >            super(p, b, i, f, t);
4834              this.action = action;
4835          }
4836 <        @SuppressWarnings("unchecked") public final boolean exec() {
4837 <            final BiAction<K,V> action = this.action;
4838 <            if (action == null)
4839 <                return abortOnNullFunction();
4840 <            ForEachMappingTask<K,V> subtasks = null;
4841 <            try {
4842 <                int b = batch(), c;
4843 <                while (b > 1 && baseIndex != baseLimit) {
4844 <                    do {} while (!casPending(c = pending, c+1));
4845 <                    (subtasks = new ForEachMappingTask<K,V>
4846 <                     (map, this, b >>>= 1, subtasks, action)).fork();
4847 <                }
4848 <                Object v;
5592 <                while ((v = advance()) != null)
5593 <                    action.apply((K)nextKey, (V)v);
5594 <            } catch (Throwable ex) {
5595 <                return tryCompleteComputation(ex);
4836 >        public final void compute() {
4837 >            final BiAction<? super K, ? super V> action;
4838 >            if ((action = this.action) != null) {
4839 >                for (int i = baseIndex, f, h; batch > 0 &&
4840 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4841 >                    addToPendingCount(1);
4842 >                    new ForEachMappingTask<K,V>
4843 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4844 >                         action).fork();
4845 >                }
4846 >                for (Node<K,V> p; (p = advance()) != null; )
4847 >                    action.apply(p.key, p.val);
4848 >                propagateCompletion();
4849              }
5597            tryComplete(subtasks);
5598            return false;
4850          }
4851      }
4852  
4853 <    @SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
4854 <        extends BulkAction<K,V,Void> {
4853 >    @SuppressWarnings("serial")
4854 >    static final class ForEachTransformedKeyTask<K,V,U>
4855 >        extends BulkTask<K,V,Void> {
4856          final Fun<? super K, ? extends U> transformer;
4857 <        final Action<U> action;
4857 >        final Action<? super U> action;
4858          ForEachTransformedKeyTask
4859 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4860 <             ForEachTransformedKeyTask<K,V,U> nextTask,
4861 <             Fun<? super K, ? extends U> transformer,
4862 <             Action<U> action) {
4863 <            super(m, p, b, nextTask);
4864 <            this.transformer = transformer;
4865 <            this.action = action;
4866 <
4867 <        }
4868 <        @SuppressWarnings("unchecked") public final boolean exec() {
4869 <            final Fun<? super K, ? extends U> transformer =
4870 <                this.transformer;
4871 <            final Action<U> action = this.action;
4872 <            if (transformer == null || action == null)
4873 <                return abortOnNullFunction();
4874 <            ForEachTransformedKeyTask<K,V,U> subtasks = null;
4875 <            try {
4876 <                int b = batch(), c;
4877 <                while (b > 1 && baseIndex != baseLimit) {
4878 <                    do {} while (!casPending(c = pending, c+1));
5627 <                    (subtasks = new ForEachTransformedKeyTask<K,V,U>
5628 <                     (map, this, b >>>= 1, subtasks, transformer, action)).fork();
5629 <                }
5630 <                U u;
5631 <                while (advance() != null) {
5632 <                    if ((u = transformer.apply((K)nextKey)) != null)
4859 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4860 >             Fun<? super K, ? extends U> transformer, Action<? super U> action) {
4861 >            super(p, b, i, f, t);
4862 >            this.transformer = transformer; this.action = action;
4863 >        }
4864 >        public final void compute() {
4865 >            final Fun<? super K, ? extends U> transformer;
4866 >            final Action<? super U> action;
4867 >            if ((transformer = this.transformer) != null &&
4868 >                (action = this.action) != null) {
4869 >                for (int i = baseIndex, f, h; batch > 0 &&
4870 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4871 >                    addToPendingCount(1);
4872 >                    new ForEachTransformedKeyTask<K,V,U>
4873 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4874 >                         transformer, action).fork();
4875 >                }
4876 >                for (Node<K,V> p; (p = advance()) != null; ) {
4877 >                    U u;
4878 >                    if ((u = transformer.apply(p.key)) != null)
4879                          action.apply(u);
4880                  }
4881 <            } catch (Throwable ex) {
5636 <                return tryCompleteComputation(ex);
4881 >                propagateCompletion();
4882              }
5638            tryComplete(subtasks);
5639            return false;
4883          }
4884      }
4885  
4886 <    @SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
4887 <        extends BulkAction<K,V,Void> {
4886 >    @SuppressWarnings("serial")
4887 >    static final class ForEachTransformedValueTask<K,V,U>
4888 >        extends BulkTask<K,V,Void> {
4889          final Fun<? super V, ? extends U> transformer;
4890 <        final Action<U> action;
4890 >        final Action<? super U> action;
4891          ForEachTransformedValueTask
4892 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4893 <             ForEachTransformedValueTask<K,V,U> nextTask,
4894 <             Fun<? super V, ? extends U> transformer,
4895 <             Action<U> action) {
4896 <            super(m, p, b, nextTask);
4897 <            this.transformer = transformer;
4898 <            this.action = action;
4899 <
4900 <        }
4901 <        @SuppressWarnings("unchecked") public final boolean exec() {
4902 <            final Fun<? super V, ? extends U> transformer =
4903 <                this.transformer;
4904 <            final Action<U> action = this.action;
4905 <            if (transformer == null || action == null)
4906 <                return abortOnNullFunction();
4907 <            ForEachTransformedValueTask<K,V,U> subtasks = null;
4908 <            try {
4909 <                int b = batch(), c;
4910 <                while (b > 1 && baseIndex != baseLimit) {
4911 <                    do {} while (!casPending(c = pending, c+1));
5668 <                    (subtasks = new ForEachTransformedValueTask<K,V,U>
5669 <                     (map, this, b >>>= 1, subtasks, transformer, action)).fork();
5670 <                }
5671 <                Object v; U u;
5672 <                while ((v = advance()) != null) {
5673 <                    if ((u = transformer.apply((V)v)) != null)
4892 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4893 >             Fun<? super V, ? extends U> transformer, Action<? super U> action) {
4894 >            super(p, b, i, f, t);
4895 >            this.transformer = transformer; this.action = action;
4896 >        }
4897 >        public final void compute() {
4898 >            final Fun<? super V, ? extends U> transformer;
4899 >            final Action<? super U> action;
4900 >            if ((transformer = this.transformer) != null &&
4901 >                (action = this.action) != null) {
4902 >                for (int i = baseIndex, f, h; batch > 0 &&
4903 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4904 >                    addToPendingCount(1);
4905 >                    new ForEachTransformedValueTask<K,V,U>
4906 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4907 >                         transformer, action).fork();
4908 >                }
4909 >                for (Node<K,V> p; (p = advance()) != null; ) {
4910 >                    U u;
4911 >                    if ((u = transformer.apply(p.val)) != null)
4912                          action.apply(u);
4913                  }
4914 <            } catch (Throwable ex) {
5677 <                return tryCompleteComputation(ex);
4914 >                propagateCompletion();
4915              }
5679            tryComplete(subtasks);
5680            return false;
4916          }
4917      }
4918  
4919 <    @SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
4920 <        extends BulkAction<K,V,Void> {
4919 >    @SuppressWarnings("serial")
4920 >    static final class ForEachTransformedEntryTask<K,V,U>
4921 >        extends BulkTask<K,V,Void> {
4922          final Fun<Map.Entry<K,V>, ? extends U> transformer;
4923 <        final Action<U> action;
4923 >        final Action<? super U> action;
4924          ForEachTransformedEntryTask
4925 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
4926 <             ForEachTransformedEntryTask<K,V,U> nextTask,
4927 <             Fun<Map.Entry<K,V>, ? extends U> transformer,
4928 <             Action<U> action) {
4929 <            super(m, p, b, nextTask);
4930 <            this.transformer = transformer;
4931 <            this.action = action;
4932 <
4933 <        }
4934 <        @SuppressWarnings("unchecked") public final boolean exec() {
4935 <            final Fun<Map.Entry<K,V>, ? extends U> transformer =
4936 <                this.transformer;
4937 <            final Action<U> action = this.action;
4938 <            if (transformer == null || action == null)
4939 <                return abortOnNullFunction();
4940 <            ForEachTransformedEntryTask<K,V,U> subtasks = null;
4941 <            try {
4942 <                int b = batch(), c;
4943 <                while (b > 1 && baseIndex != baseLimit) {
4944 <                    do {} while (!casPending(c = pending, c+1));
5709 <                    (subtasks = new ForEachTransformedEntryTask<K,V,U>
5710 <                     (map, this, b >>>= 1, subtasks, transformer, action)).fork();
5711 <                }
5712 <                Object v; U u;
5713 <                while ((v = advance()) != null) {
5714 <                    if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
4925 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4926 >             Fun<Map.Entry<K,V>, ? extends U> transformer, Action<? super U> action) {
4927 >            super(p, b, i, f, t);
4928 >            this.transformer = transformer; this.action = action;
4929 >        }
4930 >        public final void compute() {
4931 >            final Fun<Map.Entry<K,V>, ? extends U> transformer;
4932 >            final Action<? super U> action;
4933 >            if ((transformer = this.transformer) != null &&
4934 >                (action = this.action) != null) {
4935 >                for (int i = baseIndex, f, h; batch > 0 &&
4936 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4937 >                    addToPendingCount(1);
4938 >                    new ForEachTransformedEntryTask<K,V,U>
4939 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4940 >                         transformer, action).fork();
4941 >                }
4942 >                for (Node<K,V> p; (p = advance()) != null; ) {
4943 >                    U u;
4944 >                    if ((u = transformer.apply(p)) != null)
4945                          action.apply(u);
4946                  }
4947 <            } catch (Throwable ex) {
5718 <                return tryCompleteComputation(ex);
4947 >                propagateCompletion();
4948              }
5720            tryComplete(subtasks);
5721            return false;
4949          }
4950      }
4951  
4952 <    @SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
4953 <        extends BulkAction<K,V,Void> {
4952 >    @SuppressWarnings("serial")
4953 >    static final class ForEachTransformedMappingTask<K,V,U>
4954 >        extends BulkTask<K,V,Void> {
4955          final BiFun<? super K, ? super V, ? extends U> transformer;
4956 <        final Action<U> action;
4956 >        final Action<? super U> action;
4957          ForEachTransformedMappingTask
4958 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5731 <             ForEachTransformedMappingTask<K,V,U> nextTask,
4958 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4959               BiFun<? super K, ? super V, ? extends U> transformer,
4960 <             Action<U> action) {
4961 <            super(m, p, b, nextTask);
4962 <            this.transformer = transformer;
4963 <            this.action = action;
4964 <
4965 <        }
4966 <        @SuppressWarnings("unchecked") public final boolean exec() {
4967 <            final BiFun<? super K, ? super V, ? extends U> transformer =
4968 <                this.transformer;
4969 <            final Action<U> action = this.action;
4970 <            if (transformer == null || action == null)
4971 <                return abortOnNullFunction();
4972 <            ForEachTransformedMappingTask<K,V,U> subtasks = null;
4973 <            try {
4974 <                int b = batch(), c;
4975 <                while (b > 1 && baseIndex != baseLimit) {
4976 <                    do {} while (!casPending(c = pending, c+1));
4977 <                    (subtasks = new ForEachTransformedMappingTask<K,V,U>
4978 <                     (map, this, b >>>= 1, subtasks, transformer, action)).fork();
5752 <                }
5753 <                Object v; U u;
5754 <                while ((v = advance()) != null) {
5755 <                    if ((u = transformer.apply((K)nextKey, (V)v)) != null)
4960 >             Action<? super U> action) {
4961 >            super(p, b, i, f, t);
4962 >            this.transformer = transformer; this.action = action;
4963 >        }
4964 >        public final void compute() {
4965 >            final BiFun<? super K, ? super V, ? extends U> transformer;
4966 >            final Action<? super U> action;
4967 >            if ((transformer = this.transformer) != null &&
4968 >                (action = this.action) != null) {
4969 >                for (int i = baseIndex, f, h; batch > 0 &&
4970 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4971 >                    addToPendingCount(1);
4972 >                    new ForEachTransformedMappingTask<K,V,U>
4973 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4974 >                         transformer, action).fork();
4975 >                }
4976 >                for (Node<K,V> p; (p = advance()) != null; ) {
4977 >                    U u;
4978 >                    if ((u = transformer.apply(p.key, p.val)) != null)
4979                          action.apply(u);
4980                  }
4981 <            } catch (Throwable ex) {
5759 <                return tryCompleteComputation(ex);
4981 >                propagateCompletion();
4982              }
5761            tryComplete(subtasks);
5762            return false;
4983          }
4984      }
4985  
4986 <    @SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
4987 <        extends BulkAction<K,V,U> {
4986 >    @SuppressWarnings("serial")
4987 >    static final class SearchKeysTask<K,V,U>
4988 >        extends BulkTask<K,V,U> {
4989          final Fun<? super K, ? extends U> searchFunction;
4990          final AtomicReference<U> result;
4991          SearchKeysTask
4992 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5772 <             SearchKeysTask<K,V,U> nextTask,
4992 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4993               Fun<? super K, ? extends U> searchFunction,
4994               AtomicReference<U> result) {
4995 <            super(m, p, b, nextTask);
4995 >            super(p, b, i, f, t);
4996              this.searchFunction = searchFunction; this.result = result;
4997          }
4998 <        @SuppressWarnings("unchecked") public final boolean exec() {
4999 <            AtomicReference<U> result = this.result;
5000 <            final Fun<? super K, ? extends U> searchFunction =
5001 <                this.searchFunction;
5002 <            if (searchFunction == null || result == null)
5003 <                return abortOnNullFunction();
5004 <            SearchKeysTask<K,V,U> subtasks = null;
5005 <            try {
5006 <                int b = batch(), c;
5007 <                while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5008 <                    do {} while (!casPending(c = pending, c+1));
5009 <                    (subtasks = new SearchKeysTask<K,V,U>
5010 <                     (map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5011 <                }
5012 <                U u;
5013 <                while (result.get() == null && advance() != null) {
5014 <                    if ((u = searchFunction.apply((K)nextKey)) != null) {
4998 >        public final U getRawResult() { return result.get(); }
4999 >        public final void compute() {
5000 >            final Fun<? super K, ? extends U> searchFunction;
5001 >            final AtomicReference<U> result;
5002 >            if ((searchFunction = this.searchFunction) != null &&
5003 >                (result = this.result) != null) {
5004 >                for (int i = baseIndex, f, h; batch > 0 &&
5005 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5006 >                    if (result.get() != null)
5007 >                        return;
5008 >                    addToPendingCount(1);
5009 >                    new SearchKeysTask<K,V,U>
5010 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5011 >                         searchFunction, result).fork();
5012 >                }
5013 >                while (result.get() == null) {
5014 >                    U u;
5015 >                    Node<K,V> p;
5016 >                    if ((p = advance()) == null) {
5017 >                        propagateCompletion();
5018 >                        break;
5019 >                    }
5020 >                    if ((u = searchFunction.apply(p.key)) != null) {
5021                          if (result.compareAndSet(null, u))
5022 <                            tryCompleteComputation(null);
5022 >                            quietlyCompleteRoot();
5023                          break;
5024                      }
5025                  }
5800            } catch (Throwable ex) {
5801                return tryCompleteComputation(ex);
5026              }
5803            tryComplete(subtasks);
5804            return false;
5027          }
5806        public final U getRawResult() { return result.get(); }
5028      }
5029  
5030 <    @SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5031 <        extends BulkAction<K,V,U> {
5030 >    @SuppressWarnings("serial")
5031 >    static final class SearchValuesTask<K,V,U>
5032 >        extends BulkTask<K,V,U> {
5033          final Fun<? super V, ? extends U> searchFunction;
5034          final AtomicReference<U> result;
5035          SearchValuesTask
5036 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5815 <             SearchValuesTask<K,V,U> nextTask,
5036 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5037               Fun<? super V, ? extends U> searchFunction,
5038               AtomicReference<U> result) {
5039 <            super(m, p, b, nextTask);
5039 >            super(p, b, i, f, t);
5040              this.searchFunction = searchFunction; this.result = result;
5041          }
5042 <        @SuppressWarnings("unchecked") public final boolean exec() {
5043 <            AtomicReference<U> result = this.result;
5044 <            final Fun<? super V, ? extends U> searchFunction =
5045 <                this.searchFunction;
5046 <            if (searchFunction == null || result == null)
5047 <                return abortOnNullFunction();
5048 <            SearchValuesTask<K,V,U> subtasks = null;
5049 <            try {
5050 <                int b = batch(), c;
5051 <                while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5052 <                    do {} while (!casPending(c = pending, c+1));
5053 <                    (subtasks = new SearchValuesTask<K,V,U>
5054 <                     (map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5055 <                }
5056 <                Object v; U u;
5057 <                while (result.get() == null && (v = advance()) != null) {
5058 <                    if ((u = searchFunction.apply((V)v)) != null) {
5042 >        public final U getRawResult() { return result.get(); }
5043 >        public final void compute() {
5044 >            final Fun<? super V, ? extends U> searchFunction;
5045 >            final AtomicReference<U> result;
5046 >            if ((searchFunction = this.searchFunction) != null &&
5047 >                (result = this.result) != null) {
5048 >                for (int i = baseIndex, f, h; batch > 0 &&
5049 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5050 >                    if (result.get() != null)
5051 >                        return;
5052 >                    addToPendingCount(1);
5053 >                    new SearchValuesTask<K,V,U>
5054 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5055 >                         searchFunction, result).fork();
5056 >                }
5057 >                while (result.get() == null) {
5058 >                    U u;
5059 >                    Node<K,V> p;
5060 >                    if ((p = advance()) == null) {
5061 >                        propagateCompletion();
5062 >                        break;
5063 >                    }
5064 >                    if ((u = searchFunction.apply(p.val)) != null) {
5065                          if (result.compareAndSet(null, u))
5066 <                            tryCompleteComputation(null);
5066 >                            quietlyCompleteRoot();
5067                          break;
5068                      }
5069                  }
5843            } catch (Throwable ex) {
5844                return tryCompleteComputation(ex);
5070              }
5846            tryComplete(subtasks);
5847            return false;
5071          }
5849        public final U getRawResult() { return result.get(); }
5072      }
5073  
5074 <    @SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5075 <        extends BulkAction<K,V,U> {
5074 >    @SuppressWarnings("serial")
5075 >    static final class SearchEntriesTask<K,V,U>
5076 >        extends BulkTask<K,V,U> {
5077          final Fun<Entry<K,V>, ? extends U> searchFunction;
5078          final AtomicReference<U> result;
5079          SearchEntriesTask
5080 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5858 <             SearchEntriesTask<K,V,U> nextTask,
5080 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5081               Fun<Entry<K,V>, ? extends U> searchFunction,
5082               AtomicReference<U> result) {
5083 <            super(m, p, b, nextTask);
5083 >            super(p, b, i, f, t);
5084              this.searchFunction = searchFunction; this.result = result;
5085          }
5086 <        @SuppressWarnings("unchecked") public final boolean exec() {
5087 <            AtomicReference<U> result = this.result;
5088 <            final Fun<Entry<K,V>, ? extends U> searchFunction =
5089 <                this.searchFunction;
5090 <            if (searchFunction == null || result == null)
5091 <                return abortOnNullFunction();
5092 <            SearchEntriesTask<K,V,U> subtasks = null;
5093 <            try {
5094 <                int b = batch(), c;
5095 <                while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5096 <                    do {} while (!casPending(c = pending, c+1));
5097 <                    (subtasks = new SearchEntriesTask<K,V,U>
5098 <                     (map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5099 <                }
5100 <                Object v; U u;
5101 <                while (result.get() == null && (v = advance()) != null) {
5102 <                    if ((u = searchFunction.apply(entryFor((K)nextKey, (V)v))) != null) {
5103 <                        if (result.compareAndSet(null, u))
5104 <                            tryCompleteComputation(null);
5086 >        public final U getRawResult() { return result.get(); }
5087 >        public final void compute() {
5088 >            final Fun<Entry<K,V>, ? extends U> searchFunction;
5089 >            final AtomicReference<U> result;
5090 >            if ((searchFunction = this.searchFunction) != null &&
5091 >                (result = this.result) != null) {
5092 >                for (int i = baseIndex, f, h; batch > 0 &&
5093 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5094 >                    if (result.get() != null)
5095 >                        return;
5096 >                    addToPendingCount(1);
5097 >                    new SearchEntriesTask<K,V,U>
5098 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5099 >                         searchFunction, result).fork();
5100 >                }
5101 >                while (result.get() == null) {
5102 >                    U u;
5103 >                    Node<K,V> p;
5104 >                    if ((p = advance()) == null) {
5105 >                        propagateCompletion();
5106                          break;
5107                      }
5108 +                    if ((u = searchFunction.apply(p)) != null) {
5109 +                        if (result.compareAndSet(null, u))
5110 +                            quietlyCompleteRoot();
5111 +                        return;
5112 +                    }
5113                  }
5886            } catch (Throwable ex) {
5887                return tryCompleteComputation(ex);
5114              }
5889            tryComplete(subtasks);
5890            return false;
5115          }
5892        public final U getRawResult() { return result.get(); }
5116      }
5117  
5118 <    @SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5119 <        extends BulkAction<K,V,U> {
5118 >    @SuppressWarnings("serial")
5119 >    static final class SearchMappingsTask<K,V,U>
5120 >        extends BulkTask<K,V,U> {
5121          final BiFun<? super K, ? super V, ? extends U> searchFunction;
5122          final AtomicReference<U> result;
5123          SearchMappingsTask
5124 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5901 <             SearchMappingsTask<K,V,U> nextTask,
5124 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5125               BiFun<? super K, ? super V, ? extends U> searchFunction,
5126               AtomicReference<U> result) {
5127 <            super(m, p, b, nextTask);
5127 >            super(p, b, i, f, t);
5128              this.searchFunction = searchFunction; this.result = result;
5129          }
5130 <        @SuppressWarnings("unchecked") public final boolean exec() {
5131 <            AtomicReference<U> result = this.result;
5132 <            final BiFun<? super K, ? super V, ? extends U> searchFunction =
5133 <                this.searchFunction;
5134 <            if (searchFunction == null || result == null)
5135 <                return abortOnNullFunction();
5136 <            SearchMappingsTask<K,V,U> subtasks = null;
5137 <            try {
5138 <                int b = batch(), c;
5139 <                while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5140 <                    do {} while (!casPending(c = pending, c+1));
5141 <                    (subtasks = new SearchMappingsTask<K,V,U>
5142 <                     (map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5143 <                }
5144 <                Object v; U u;
5145 <                while (result.get() == null && (v = advance()) != null) {
5146 <                    if ((u = searchFunction.apply((K)nextKey, (V)v)) != null) {
5130 >        public final U getRawResult() { return result.get(); }
5131 >        public final void compute() {
5132 >            final BiFun<? super K, ? super V, ? extends U> searchFunction;
5133 >            final AtomicReference<U> result;
5134 >            if ((searchFunction = this.searchFunction) != null &&
5135 >                (result = this.result) != null) {
5136 >                for (int i = baseIndex, f, h; batch > 0 &&
5137 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5138 >                    if (result.get() != null)
5139 >                        return;
5140 >                    addToPendingCount(1);
5141 >                    new SearchMappingsTask<K,V,U>
5142 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5143 >                         searchFunction, result).fork();
5144 >                }
5145 >                while (result.get() == null) {
5146 >                    U u;
5147 >                    Node<K,V> p;
5148 >                    if ((p = advance()) == null) {
5149 >                        propagateCompletion();
5150 >                        break;
5151 >                    }
5152 >                    if ((u = searchFunction.apply(p.key, p.val)) != null) {
5153                          if (result.compareAndSet(null, u))
5154 <                            tryCompleteComputation(null);
5154 >                            quietlyCompleteRoot();
5155                          break;
5156                      }
5157                  }
5929            } catch (Throwable ex) {
5930                return tryCompleteComputation(ex);
5158              }
5932            tryComplete(subtasks);
5933            return false;
5159          }
5935        public final U getRawResult() { return result.get(); }
5160      }
5161  
5162 <    @SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5162 >    @SuppressWarnings("serial")
5163 >    static final class ReduceKeysTask<K,V>
5164          extends BulkTask<K,V,K> {
5165          final BiFun<? super K, ? super K, ? extends K> reducer;
5166          K result;
5167          ReduceKeysTask<K,V> rights, nextRight;
5168          ReduceKeysTask
5169 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5169 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5170               ReduceKeysTask<K,V> nextRight,
5171               BiFun<? super K, ? super K, ? extends K> reducer) {
5172 <            super(m, p, b); this.nextRight = nextRight;
5172 >            super(p, b, i, f, t); this.nextRight = nextRight;
5173              this.reducer = reducer;
5174          }
5175 <        @SuppressWarnings("unchecked") public final boolean exec() {
5176 <            final BiFun<? super K, ? super K, ? extends K> reducer =
5177 <                this.reducer;
5178 <            if (reducer == null)
5179 <                return abortOnNullFunction();
5180 <            try {
5181 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5957 <                    do {} while (!casPending(c = pending, c+1));
5175 >        public final K getRawResult() { return result; }
5176 >        public final void compute() {
5177 >            final BiFun<? super K, ? super K, ? extends K> reducer;
5178 >            if ((reducer = this.reducer) != null) {
5179 >                for (int i = baseIndex, f, h; batch > 0 &&
5180 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5181 >                    addToPendingCount(1);
5182                      (rights = new ReduceKeysTask<K,V>
5183 <                     (map, this, b >>>= 1, rights, reducer)).fork();
5183 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5184 >                      rights, reducer)).fork();
5185                  }
5186                  K r = null;
5187 <                while (advance() != null) {
5188 <                    K u = (K)nextKey;
5189 <                    r = (r == null) ? u : reducer.apply(r, u);
5187 >                for (Node<K,V> p; (p = advance()) != null; ) {
5188 >                    K u = p.key;
5189 >                    r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5190                  }
5191                  result = r;
5192 <                for (ReduceKeysTask<K,V> t = this, s;;) {
5193 <                    int c; BulkTask<K,V,?> par; K tr, sr;
5194 <                    if ((c = t.pending) == 0) {
5195 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5196 <                            if ((sr = s.result) != null)
5197 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5198 <                        }
5199 <                        if ((par = t.parent) == null ||
5200 <                            !(par instanceof ReduceKeysTask)) {
5201 <                            t.quietlyComplete();
5202 <                            break;
5978 <                        }
5979 <                        t = (ReduceKeysTask<K,V>)par;
5192 >                CountedCompleter<?> c;
5193 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5194 >                    @SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5195 >                        t = (ReduceKeysTask<K,V>)c,
5196 >                        s = t.rights;
5197 >                    while (s != null) {
5198 >                        K tr, sr;
5199 >                        if ((sr = s.result) != null)
5200 >                            t.result = (((tr = t.result) == null) ? sr :
5201 >                                        reducer.apply(tr, sr));
5202 >                        s = t.rights = s.nextRight;
5203                      }
5981                    else if (t.casPending(c, c - 1))
5982                        break;
5204                  }
5984            } catch (Throwable ex) {
5985                return tryCompleteComputation(ex);
5205              }
5987            ReduceKeysTask<K,V> s = rights;
5988            if (s != null && !inForkJoinPool()) {
5989                do  {
5990                    if (s.tryUnfork())
5991                        s.exec();
5992                } while ((s = s.nextRight) != null);
5993            }
5994            return false;
5206          }
5996        public final K getRawResult() { return result; }
5207      }
5208  
5209 <    @SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
5209 >    @SuppressWarnings("serial")
5210 >    static final class ReduceValuesTask<K,V>
5211          extends BulkTask<K,V,V> {
5212          final BiFun<? super V, ? super V, ? extends V> reducer;
5213          V result;
5214          ReduceValuesTask<K,V> rights, nextRight;
5215          ReduceValuesTask
5216 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5216 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5217               ReduceValuesTask<K,V> nextRight,
5218               BiFun<? super V, ? super V, ? extends V> reducer) {
5219 <            super(m, p, b); this.nextRight = nextRight;
5219 >            super(p, b, i, f, t); this.nextRight = nextRight;
5220              this.reducer = reducer;
5221          }
5222 <        @SuppressWarnings("unchecked") public final boolean exec() {
5223 <            final BiFun<? super V, ? super V, ? extends V> reducer =
5224 <                this.reducer;
5225 <            if (reducer == null)
5226 <                return abortOnNullFunction();
5227 <            try {
5228 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6018 <                    do {} while (!casPending(c = pending, c+1));
5222 >        public final V getRawResult() { return result; }
5223 >        public final void compute() {
5224 >            final BiFun<? super V, ? super V, ? extends V> reducer;
5225 >            if ((reducer = this.reducer) != null) {
5226 >                for (int i = baseIndex, f, h; batch > 0 &&
5227 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5228 >                    addToPendingCount(1);
5229                      (rights = new ReduceValuesTask<K,V>
5230 <                     (map, this, b >>>= 1, rights, reducer)).fork();
5230 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5231 >                      rights, reducer)).fork();
5232                  }
5233                  V r = null;
5234 <                Object v;
5235 <                while ((v = advance()) != null) {
5236 <                    V u = (V)v;
6026 <                    r = (r == null) ? u : reducer.apply(r, u);
5234 >                for (Node<K,V> p; (p = advance()) != null; ) {
5235 >                    V v = p.val;
5236 >                    r = (r == null) ? v : reducer.apply(r, v);
5237                  }
5238                  result = r;
5239 <                for (ReduceValuesTask<K,V> t = this, s;;) {
5240 <                    int c; BulkTask<K,V,?> par; V tr, sr;
5241 <                    if ((c = t.pending) == 0) {
5242 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5243 <                            if ((sr = s.result) != null)
5244 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5245 <                        }
5246 <                        if ((par = t.parent) == null ||
5247 <                            !(par instanceof ReduceValuesTask)) {
5248 <                            t.quietlyComplete();
5249 <                            break;
6040 <                        }
6041 <                        t = (ReduceValuesTask<K,V>)par;
5239 >                CountedCompleter<?> c;
5240 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5241 >                    @SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5242 >                        t = (ReduceValuesTask<K,V>)c,
5243 >                        s = t.rights;
5244 >                    while (s != null) {
5245 >                        V tr, sr;
5246 >                        if ((sr = s.result) != null)
5247 >                            t.result = (((tr = t.result) == null) ? sr :
5248 >                                        reducer.apply(tr, sr));
5249 >                        s = t.rights = s.nextRight;
5250                      }
6043                    else if (t.casPending(c, c - 1))
6044                        break;
5251                  }
6046            } catch (Throwable ex) {
6047                return tryCompleteComputation(ex);
6048            }
6049            ReduceValuesTask<K,V> s = rights;
6050            if (s != null && !inForkJoinPool()) {
6051                do  {
6052                    if (s.tryUnfork())
6053                        s.exec();
6054                } while ((s = s.nextRight) != null);
5252              }
6056            return false;
5253          }
6058        public final V getRawResult() { return result; }
5254      }
5255  
5256 <    @SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
5256 >    @SuppressWarnings("serial")
5257 >    static final class ReduceEntriesTask<K,V>
5258          extends BulkTask<K,V,Map.Entry<K,V>> {
5259          final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5260          Map.Entry<K,V> result;
5261          ReduceEntriesTask<K,V> rights, nextRight;
5262          ReduceEntriesTask
5263 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5263 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5264               ReduceEntriesTask<K,V> nextRight,
5265               BiFun<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5266 <            super(m, p, b); this.nextRight = nextRight;
5266 >            super(p, b, i, f, t); this.nextRight = nextRight;
5267              this.reducer = reducer;
5268          }
5269 <        @SuppressWarnings("unchecked") public final boolean exec() {
5270 <            final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer =
5271 <                this.reducer;
5272 <            if (reducer == null)
5273 <                return abortOnNullFunction();
5274 <            try {
5275 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6080 <                    do {} while (!casPending(c = pending, c+1));
5269 >        public final Map.Entry<K,V> getRawResult() { return result; }
5270 >        public final void compute() {
5271 >            final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5272 >            if ((reducer = this.reducer) != null) {
5273 >                for (int i = baseIndex, f, h; batch > 0 &&
5274 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5275 >                    addToPendingCount(1);
5276                      (rights = new ReduceEntriesTask<K,V>
5277 <                     (map, this, b >>>= 1, rights, reducer)).fork();
5277 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5278 >                      rights, reducer)).fork();
5279                  }
5280                  Map.Entry<K,V> r = null;
5281 <                Object v;
5282 <                while ((v = advance()) != null) {
6087 <                    Map.Entry<K,V> u = entryFor((K)nextKey, (V)v);
6088 <                    r = (r == null) ? u : reducer.apply(r, u);
6089 <                }
5281 >                for (Node<K,V> p; (p = advance()) != null; )
5282 >                    r = (r == null) ? p : reducer.apply(r, p);
5283                  result = r;
5284 <                for (ReduceEntriesTask<K,V> t = this, s;;) {
5285 <                    int c; BulkTask<K,V,?> par; Map.Entry<K,V> tr, sr;
5286 <                    if ((c = t.pending) == 0) {
5287 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5288 <                            if ((sr = s.result) != null)
5289 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5290 <                        }
5291 <                        if ((par = t.parent) == null ||
5292 <                            !(par instanceof ReduceEntriesTask)) {
5293 <                            t.quietlyComplete();
5294 <                            break;
6102 <                        }
6103 <                        t = (ReduceEntriesTask<K,V>)par;
5284 >                CountedCompleter<?> c;
5285 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5286 >                    @SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5287 >                        t = (ReduceEntriesTask<K,V>)c,
5288 >                        s = t.rights;
5289 >                    while (s != null) {
5290 >                        Map.Entry<K,V> tr, sr;
5291 >                        if ((sr = s.result) != null)
5292 >                            t.result = (((tr = t.result) == null) ? sr :
5293 >                                        reducer.apply(tr, sr));
5294 >                        s = t.rights = s.nextRight;
5295                      }
6105                    else if (t.casPending(c, c - 1))
6106                        break;
5296                  }
6108            } catch (Throwable ex) {
6109                return tryCompleteComputation(ex);
5297              }
6111            ReduceEntriesTask<K,V> s = rights;
6112            if (s != null && !inForkJoinPool()) {
6113                do  {
6114                    if (s.tryUnfork())
6115                        s.exec();
6116                } while ((s = s.nextRight) != null);
6117            }
6118            return false;
5298          }
6120        public final Map.Entry<K,V> getRawResult() { return result; }
5299      }
5300  
5301 <    @SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
5301 >    @SuppressWarnings("serial")
5302 >    static final class MapReduceKeysTask<K,V,U>
5303          extends BulkTask<K,V,U> {
5304          final Fun<? super K, ? extends U> transformer;
5305          final BiFun<? super U, ? super U, ? extends U> reducer;
5306          U result;
5307          MapReduceKeysTask<K,V,U> rights, nextRight;
5308          MapReduceKeysTask
5309 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5309 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5310               MapReduceKeysTask<K,V,U> nextRight,
5311               Fun<? super K, ? extends U> transformer,
5312               BiFun<? super U, ? super U, ? extends U> reducer) {
5313 <            super(m, p, b); this.nextRight = nextRight;
5313 >            super(p, b, i, f, t); this.nextRight = nextRight;
5314              this.transformer = transformer;
5315              this.reducer = reducer;
5316          }
5317 <        @SuppressWarnings("unchecked") public final boolean exec() {
5318 <            final Fun<? super K, ? extends U> transformer =
5319 <                this.transformer;
5320 <            final BiFun<? super U, ? super U, ? extends U> reducer =
5321 <                this.reducer;
5322 <            if (transformer == null || reducer == null)
5323 <                return abortOnNullFunction();
5324 <            try {
5325 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6147 <                    do {} while (!casPending(c = pending, c+1));
5317 >        public final U getRawResult() { return result; }
5318 >        public final void compute() {
5319 >            final Fun<? super K, ? extends U> transformer;
5320 >            final BiFun<? super U, ? super U, ? extends U> reducer;
5321 >            if ((transformer = this.transformer) != null &&
5322 >                (reducer = this.reducer) != null) {
5323 >                for (int i = baseIndex, f, h; batch > 0 &&
5324 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5325 >                    addToPendingCount(1);
5326                      (rights = new MapReduceKeysTask<K,V,U>
5327 <                     (map, this, b >>>= 1, rights, transformer, reducer)).fork();
5327 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5328 >                      rights, transformer, reducer)).fork();
5329                  }
5330 <                U r = null, u;
5331 <                while (advance() != null) {
5332 <                    if ((u = transformer.apply((K)nextKey)) != null)
5330 >                U r = null;
5331 >                for (Node<K,V> p; (p = advance()) != null; ) {
5332 >                    U u;
5333 >                    if ((u = transformer.apply(p.key)) != null)
5334                          r = (r == null) ? u : reducer.apply(r, u);
5335                  }
5336                  result = r;
5337 <                for (MapReduceKeysTask<K,V,U> t = this, s;;) {
5338 <                    int c; BulkTask<K,V,?> par; U tr, sr;
5339 <                    if ((c = t.pending) == 0) {
5340 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5341 <                            if ((sr = s.result) != null)
5342 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5343 <                        }
5344 <                        if ((par = t.parent) == null ||
5345 <                            !(par instanceof MapReduceKeysTask)) {
5346 <                            t.quietlyComplete();
5347 <                            break;
6168 <                        }
6169 <                        t = (MapReduceKeysTask<K,V,U>)par;
5337 >                CountedCompleter<?> c;
5338 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5339 >                    @SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5340 >                        t = (MapReduceKeysTask<K,V,U>)c,
5341 >                        s = t.rights;
5342 >                    while (s != null) {
5343 >                        U tr, sr;
5344 >                        if ((sr = s.result) != null)
5345 >                            t.result = (((tr = t.result) == null) ? sr :
5346 >                                        reducer.apply(tr, sr));
5347 >                        s = t.rights = s.nextRight;
5348                      }
6171                    else if (t.casPending(c, c - 1))
6172                        break;
5349                  }
6174            } catch (Throwable ex) {
6175                return tryCompleteComputation(ex);
6176            }
6177            MapReduceKeysTask<K,V,U> s = rights;
6178            if (s != null && !inForkJoinPool()) {
6179                do  {
6180                    if (s.tryUnfork())
6181                        s.exec();
6182                } while ((s = s.nextRight) != null);
5350              }
6184            return false;
5351          }
6186        public final U getRawResult() { return result; }
5352      }
5353  
5354 <    @SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
5354 >    @SuppressWarnings("serial")
5355 >    static final class MapReduceValuesTask<K,V,U>
5356          extends BulkTask<K,V,U> {
5357          final Fun<? super V, ? extends U> transformer;
5358          final BiFun<? super U, ? super U, ? extends U> reducer;
5359          U result;
5360          MapReduceValuesTask<K,V,U> rights, nextRight;
5361          MapReduceValuesTask
5362 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5362 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5363               MapReduceValuesTask<K,V,U> nextRight,
5364               Fun<? super V, ? extends U> transformer,
5365               BiFun<? super U, ? super U, ? extends U> reducer) {
5366 <            super(m, p, b); this.nextRight = nextRight;
5366 >            super(p, b, i, f, t); this.nextRight = nextRight;
5367              this.transformer = transformer;
5368              this.reducer = reducer;
5369          }
5370 <        @SuppressWarnings("unchecked") public final boolean exec() {
5371 <            final Fun<? super V, ? extends U> transformer =
5372 <                this.transformer;
5373 <            final BiFun<? super U, ? super U, ? extends U> reducer =
5374 <                this.reducer;
5375 <            if (transformer == null || reducer == null)
5376 <                return abortOnNullFunction();
5377 <            try {
5378 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6213 <                    do {} while (!casPending(c = pending, c+1));
5370 >        public final U getRawResult() { return result; }
5371 >        public final void compute() {
5372 >            final Fun<? super V, ? extends U> transformer;
5373 >            final BiFun<? super U, ? super U, ? extends U> reducer;
5374 >            if ((transformer = this.transformer) != null &&
5375 >                (reducer = this.reducer) != null) {
5376 >                for (int i = baseIndex, f, h; batch > 0 &&
5377 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5378 >                    addToPendingCount(1);
5379                      (rights = new MapReduceValuesTask<K,V,U>
5380 <                     (map, this, b >>>= 1, rights, transformer, reducer)).fork();
5380 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5381 >                      rights, transformer, reducer)).fork();
5382                  }
5383 <                U r = null, u;
5384 <                Object v;
5385 <                while ((v = advance()) != null) {
5386 <                    if ((u = transformer.apply((V)v)) != null)
5383 >                U r = null;
5384 >                for (Node<K,V> p; (p = advance()) != null; ) {
5385 >                    U u;
5386 >                    if ((u = transformer.apply(p.val)) != null)
5387                          r = (r == null) ? u : reducer.apply(r, u);
5388                  }
5389                  result = r;
5390 <                for (MapReduceValuesTask<K,V,U> t = this, s;;) {
5391 <                    int c; BulkTask<K,V,?> par; U tr, sr;
5392 <                    if ((c = t.pending) == 0) {
5393 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5394 <                            if ((sr = s.result) != null)
5395 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5396 <                        }
5397 <                        if ((par = t.parent) == null ||
5398 <                            !(par instanceof MapReduceValuesTask)) {
5399 <                            t.quietlyComplete();
5400 <                            break;
6235 <                        }
6236 <                        t = (MapReduceValuesTask<K,V,U>)par;
5390 >                CountedCompleter<?> c;
5391 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5392 >                    @SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5393 >                        t = (MapReduceValuesTask<K,V,U>)c,
5394 >                        s = t.rights;
5395 >                    while (s != null) {
5396 >                        U tr, sr;
5397 >                        if ((sr = s.result) != null)
5398 >                            t.result = (((tr = t.result) == null) ? sr :
5399 >                                        reducer.apply(tr, sr));
5400 >                        s = t.rights = s.nextRight;
5401                      }
6238                    else if (t.casPending(c, c - 1))
6239                        break;
5402                  }
6241            } catch (Throwable ex) {
6242                return tryCompleteComputation(ex);
5403              }
6244            MapReduceValuesTask<K,V,U> s = rights;
6245            if (s != null && !inForkJoinPool()) {
6246                do  {
6247                    if (s.tryUnfork())
6248                        s.exec();
6249                } while ((s = s.nextRight) != null);
6250            }
6251            return false;
5404          }
6253        public final U getRawResult() { return result; }
5405      }
5406  
5407 <    @SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
5407 >    @SuppressWarnings("serial")
5408 >    static final class MapReduceEntriesTask<K,V,U>
5409          extends BulkTask<K,V,U> {
5410          final Fun<Map.Entry<K,V>, ? extends U> transformer;
5411          final BiFun<? super U, ? super U, ? extends U> reducer;
5412          U result;
5413          MapReduceEntriesTask<K,V,U> rights, nextRight;
5414          MapReduceEntriesTask
5415 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5415 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5416               MapReduceEntriesTask<K,V,U> nextRight,
5417               Fun<Map.Entry<K,V>, ? extends U> transformer,
5418               BiFun<? super U, ? super U, ? extends U> reducer) {
5419 <            super(m, p, b); this.nextRight = nextRight;
5419 >            super(p, b, i, f, t); this.nextRight = nextRight;
5420              this.transformer = transformer;
5421              this.reducer = reducer;
5422          }
5423 <        @SuppressWarnings("unchecked") public final boolean exec() {
5424 <            final Fun<Map.Entry<K,V>, ? extends U> transformer =
5425 <                this.transformer;
5426 <            final BiFun<? super U, ? super U, ? extends U> reducer =
5427 <                this.reducer;
5428 <            if (transformer == null || reducer == null)
5429 <                return abortOnNullFunction();
5430 <            try {
5431 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6280 <                    do {} while (!casPending(c = pending, c+1));
5423 >        public final U getRawResult() { return result; }
5424 >        public final void compute() {
5425 >            final Fun<Map.Entry<K,V>, ? extends U> transformer;
5426 >            final BiFun<? super U, ? super U, ? extends U> reducer;
5427 >            if ((transformer = this.transformer) != null &&
5428 >                (reducer = this.reducer) != null) {
5429 >                for (int i = baseIndex, f, h; batch > 0 &&
5430 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5431 >                    addToPendingCount(1);
5432                      (rights = new MapReduceEntriesTask<K,V,U>
5433 <                     (map, this, b >>>= 1, rights, transformer, reducer)).fork();
5433 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5434 >                      rights, transformer, reducer)).fork();
5435                  }
5436 <                U r = null, u;
5437 <                Object v;
5438 <                while ((v = advance()) != null) {
5439 <                    if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
5436 >                U r = null;
5437 >                for (Node<K,V> p; (p = advance()) != null; ) {
5438 >                    U u;
5439 >                    if ((u = transformer.apply(p)) != null)
5440                          r = (r == null) ? u : reducer.apply(r, u);
5441                  }
5442                  result = r;
5443 <                for (MapReduceEntriesTask<K,V,U> t = this, s;;) {
5444 <                    int c; BulkTask<K,V,?> par; U tr, sr;
5445 <                    if ((c = t.pending) == 0) {
5446 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5447 <                            if ((sr = s.result) != null)
5448 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5449 <                        }
5450 <                        if ((par = t.parent) == null ||
5451 <                            !(par instanceof MapReduceEntriesTask)) {
5452 <                            t.quietlyComplete();
5453 <                            break;
6302 <                        }
6303 <                        t = (MapReduceEntriesTask<K,V,U>)par;
5443 >                CountedCompleter<?> c;
5444 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5445 >                    @SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5446 >                        t = (MapReduceEntriesTask<K,V,U>)c,
5447 >                        s = t.rights;
5448 >                    while (s != null) {
5449 >                        U tr, sr;
5450 >                        if ((sr = s.result) != null)
5451 >                            t.result = (((tr = t.result) == null) ? sr :
5452 >                                        reducer.apply(tr, sr));
5453 >                        s = t.rights = s.nextRight;
5454                      }
6305                    else if (t.casPending(c, c - 1))
6306                        break;
5455                  }
6308            } catch (Throwable ex) {
6309                return tryCompleteComputation(ex);
5456              }
6311            MapReduceEntriesTask<K,V,U> s = rights;
6312            if (s != null && !inForkJoinPool()) {
6313                do  {
6314                    if (s.tryUnfork())
6315                        s.exec();
6316                } while ((s = s.nextRight) != null);
6317            }
6318            return false;
5457          }
6320        public final U getRawResult() { return result; }
5458      }
5459  
5460 <    @SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
5460 >    @SuppressWarnings("serial")
5461 >    static final class MapReduceMappingsTask<K,V,U>
5462          extends BulkTask<K,V,U> {
5463          final BiFun<? super K, ? super V, ? extends U> transformer;
5464          final BiFun<? super U, ? super U, ? extends U> reducer;
5465          U result;
5466          MapReduceMappingsTask<K,V,U> rights, nextRight;
5467          MapReduceMappingsTask
5468 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5468 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5469               MapReduceMappingsTask<K,V,U> nextRight,
5470               BiFun<? super K, ? super V, ? extends U> transformer,
5471               BiFun<? super U, ? super U, ? extends U> reducer) {
5472 <            super(m, p, b); this.nextRight = nextRight;
5472 >            super(p, b, i, f, t); this.nextRight = nextRight;
5473              this.transformer = transformer;
5474              this.reducer = reducer;
5475          }
5476 <        @SuppressWarnings("unchecked") public final boolean exec() {
5477 <            final BiFun<? super K, ? super V, ? extends U> transformer =
5478 <                this.transformer;
5479 <            final BiFun<? super U, ? super U, ? extends U> reducer =
5480 <                this.reducer;
5481 <            if (transformer == null || reducer == null)
5482 <                return abortOnNullFunction();
5483 <            try {
5484 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6347 <                    do {} while (!casPending(c = pending, c+1));
5476 >        public final U getRawResult() { return result; }
5477 >        public final void compute() {
5478 >            final BiFun<? super K, ? super V, ? extends U> transformer;
5479 >            final BiFun<? super U, ? super U, ? extends U> reducer;
5480 >            if ((transformer = this.transformer) != null &&
5481 >                (reducer = this.reducer) != null) {
5482 >                for (int i = baseIndex, f, h; batch > 0 &&
5483 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5484 >                    addToPendingCount(1);
5485                      (rights = new MapReduceMappingsTask<K,V,U>
5486 <                     (map, this, b >>>= 1, rights, transformer, reducer)).fork();
5486 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5487 >                      rights, transformer, reducer)).fork();
5488                  }
5489 <                U r = null, u;
5490 <                Object v;
5491 <                while ((v = advance()) != null) {
5492 <                    if ((u = transformer.apply((K)nextKey, (V)v)) != null)
5489 >                U r = null;
5490 >                for (Node<K,V> p; (p = advance()) != null; ) {
5491 >                    U u;
5492 >                    if ((u = transformer.apply(p.key, p.val)) != null)
5493                          r = (r == null) ? u : reducer.apply(r, u);
5494                  }
5495                  result = r;
5496 <                for (MapReduceMappingsTask<K,V,U> t = this, s;;) {
5497 <                    int c; BulkTask<K,V,?> par; U tr, sr;
5498 <                    if ((c = t.pending) == 0) {
5499 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5500 <                            if ((sr = s.result) != null)
5501 <                                t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5502 <                        }
5503 <                        if ((par = t.parent) == null ||
5504 <                            !(par instanceof MapReduceMappingsTask)) {
5505 <                            t.quietlyComplete();
5506 <                            break;
6369 <                        }
6370 <                        t = (MapReduceMappingsTask<K,V,U>)par;
5496 >                CountedCompleter<?> c;
5497 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5498 >                    @SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5499 >                        t = (MapReduceMappingsTask<K,V,U>)c,
5500 >                        s = t.rights;
5501 >                    while (s != null) {
5502 >                        U tr, sr;
5503 >                        if ((sr = s.result) != null)
5504 >                            t.result = (((tr = t.result) == null) ? sr :
5505 >                                        reducer.apply(tr, sr));
5506 >                        s = t.rights = s.nextRight;
5507                      }
6372                    else if (t.casPending(c, c - 1))
6373                        break;
5508                  }
6375            } catch (Throwable ex) {
6376                return tryCompleteComputation(ex);
6377            }
6378            MapReduceMappingsTask<K,V,U> s = rights;
6379            if (s != null && !inForkJoinPool()) {
6380                do  {
6381                    if (s.tryUnfork())
6382                        s.exec();
6383                } while ((s = s.nextRight) != null);
5509              }
6385            return false;
5510          }
6387        public final U getRawResult() { return result; }
5511      }
5512  
5513 <    @SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
5513 >    @SuppressWarnings("serial")
5514 >    static final class MapReduceKeysToDoubleTask<K,V>
5515          extends BulkTask<K,V,Double> {
5516          final ObjectToDouble<? super K> transformer;
5517          final DoubleByDoubleToDouble reducer;
# Line 6395 | Line 5519 | public class ConcurrentHashMapV8<K, V>
5519          double result;
5520          MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5521          MapReduceKeysToDoubleTask
5522 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5522 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5523               MapReduceKeysToDoubleTask<K,V> nextRight,
5524               ObjectToDouble<? super K> transformer,
5525               double basis,
5526               DoubleByDoubleToDouble reducer) {
5527 <            super(m, p, b); this.nextRight = nextRight;
5527 >            super(p, b, i, f, t); this.nextRight = nextRight;
5528              this.transformer = transformer;
5529              this.basis = basis; this.reducer = reducer;
5530          }
5531 <        @SuppressWarnings("unchecked") public final boolean exec() {
5532 <            final ObjectToDouble<? super K> transformer =
5533 <                this.transformer;
5534 <            final DoubleByDoubleToDouble reducer = this.reducer;
5535 <            if (transformer == null || reducer == null)
5536 <                return abortOnNullFunction();
5537 <            try {
5538 <                final double id = this.basis;
5539 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5540 <                    do {} while (!casPending(c = pending, c+1));
5531 >        public final Double getRawResult() { return result; }
5532 >        public final void compute() {
5533 >            final ObjectToDouble<? super K> transformer;
5534 >            final DoubleByDoubleToDouble reducer;
5535 >            if ((transformer = this.transformer) != null &&
5536 >                (reducer = this.reducer) != null) {
5537 >                double r = this.basis;
5538 >                for (int i = baseIndex, f, h; batch > 0 &&
5539 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5540 >                    addToPendingCount(1);
5541                      (rights = new MapReduceKeysToDoubleTask<K,V>
5542 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5542 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5543 >                      rights, transformer, r, reducer)).fork();
5544                  }
5545 <                double r = id;
5546 <                while (advance() != null)
6422 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5545 >                for (Node<K,V> p; (p = advance()) != null; )
5546 >                    r = reducer.apply(r, transformer.apply(p.key));
5547                  result = r;
5548 <                for (MapReduceKeysToDoubleTask<K,V> t = this, s;;) {
5549 <                    int c; BulkTask<K,V,?> par;
5550 <                    if ((c = t.pending) == 0) {
5551 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5552 <                            t.result = reducer.apply(t.result, s.result);
5553 <                        }
5554 <                        if ((par = t.parent) == null ||
5555 <                            !(par instanceof MapReduceKeysToDoubleTask)) {
6432 <                            t.quietlyComplete();
6433 <                            break;
6434 <                        }
6435 <                        t = (MapReduceKeysToDoubleTask<K,V>)par;
5548 >                CountedCompleter<?> c;
5549 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5550 >                    @SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5551 >                        t = (MapReduceKeysToDoubleTask<K,V>)c,
5552 >                        s = t.rights;
5553 >                    while (s != null) {
5554 >                        t.result = reducer.apply(t.result, s.result);
5555 >                        s = t.rights = s.nextRight;
5556                      }
6437                    else if (t.casPending(c, c - 1))
6438                        break;
5557                  }
6440            } catch (Throwable ex) {
6441                return tryCompleteComputation(ex);
6442            }
6443            MapReduceKeysToDoubleTask<K,V> s = rights;
6444            if (s != null && !inForkJoinPool()) {
6445                do  {
6446                    if (s.tryUnfork())
6447                        s.exec();
6448                } while ((s = s.nextRight) != null);
5558              }
6450            return false;
5559          }
6452        public final Double getRawResult() { return result; }
5560      }
5561  
5562 <    @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
5562 >    @SuppressWarnings("serial")
5563 >    static final class MapReduceValuesToDoubleTask<K,V>
5564          extends BulkTask<K,V,Double> {
5565          final ObjectToDouble<? super V> transformer;
5566          final DoubleByDoubleToDouble reducer;
# Line 6460 | Line 5568 | public class ConcurrentHashMapV8<K, V>
5568          double result;
5569          MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5570          MapReduceValuesToDoubleTask
5571 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5571 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5572               MapReduceValuesToDoubleTask<K,V> nextRight,
5573               ObjectToDouble<? super V> transformer,
5574               double basis,
5575               DoubleByDoubleToDouble reducer) {
5576 <            super(m, p, b); this.nextRight = nextRight;
5576 >            super(p, b, i, f, t); this.nextRight = nextRight;
5577              this.transformer = transformer;
5578              this.basis = basis; this.reducer = reducer;
5579          }
5580 <        @SuppressWarnings("unchecked") public final boolean exec() {
5581 <            final ObjectToDouble<? super V> transformer =
5582 <                this.transformer;
5583 <            final DoubleByDoubleToDouble reducer = this.reducer;
5584 <            if (transformer == null || reducer == null)
5585 <                return abortOnNullFunction();
5586 <            try {
5587 <                final double id = this.basis;
5588 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5589 <                    do {} while (!casPending(c = pending, c+1));
5580 >        public final Double getRawResult() { return result; }
5581 >        public final void compute() {
5582 >            final ObjectToDouble<? super V> transformer;
5583 >            final DoubleByDoubleToDouble reducer;
5584 >            if ((transformer = this.transformer) != null &&
5585 >                (reducer = this.reducer) != null) {
5586 >                double r = this.basis;
5587 >                for (int i = baseIndex, f, h; batch > 0 &&
5588 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5589 >                    addToPendingCount(1);
5590                      (rights = new MapReduceValuesToDoubleTask<K,V>
5591 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5591 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5592 >                      rights, transformer, r, reducer)).fork();
5593                  }
5594 <                double r = id;
5595 <                Object v;
6487 <                while ((v = advance()) != null)
6488 <                    r = reducer.apply(r, transformer.apply((V)v));
5594 >                for (Node<K,V> p; (p = advance()) != null; )
5595 >                    r = reducer.apply(r, transformer.apply(p.val));
5596                  result = r;
5597 <                for (MapReduceValuesToDoubleTask<K,V> t = this, s;;) {
5598 <                    int c; BulkTask<K,V,?> par;
5599 <                    if ((c = t.pending) == 0) {
5600 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5601 <                            t.result = reducer.apply(t.result, s.result);
5602 <                        }
5603 <                        if ((par = t.parent) == null ||
5604 <                            !(par instanceof MapReduceValuesToDoubleTask)) {
6498 <                            t.quietlyComplete();
6499 <                            break;
6500 <                        }
6501 <                        t = (MapReduceValuesToDoubleTask<K,V>)par;
5597 >                CountedCompleter<?> c;
5598 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5599 >                    @SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5600 >                        t = (MapReduceValuesToDoubleTask<K,V>)c,
5601 >                        s = t.rights;
5602 >                    while (s != null) {
5603 >                        t.result = reducer.apply(t.result, s.result);
5604 >                        s = t.rights = s.nextRight;
5605                      }
6503                    else if (t.casPending(c, c - 1))
6504                        break;
5606                  }
6506            } catch (Throwable ex) {
6507                return tryCompleteComputation(ex);
5607              }
6509            MapReduceValuesToDoubleTask<K,V> s = rights;
6510            if (s != null && !inForkJoinPool()) {
6511                do  {
6512                    if (s.tryUnfork())
6513                        s.exec();
6514                } while ((s = s.nextRight) != null);
6515            }
6516            return false;
5608          }
6518        public final Double getRawResult() { return result; }
5609      }
5610  
5611 <    @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
5611 >    @SuppressWarnings("serial")
5612 >    static final class MapReduceEntriesToDoubleTask<K,V>
5613          extends BulkTask<K,V,Double> {
5614          final ObjectToDouble<Map.Entry<K,V>> transformer;
5615          final DoubleByDoubleToDouble reducer;
# Line 6526 | Line 5617 | public class ConcurrentHashMapV8<K, V>
5617          double result;
5618          MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5619          MapReduceEntriesToDoubleTask
5620 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5620 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5621               MapReduceEntriesToDoubleTask<K,V> nextRight,
5622               ObjectToDouble<Map.Entry<K,V>> transformer,
5623               double basis,
5624               DoubleByDoubleToDouble reducer) {
5625 <            super(m, p, b); this.nextRight = nextRight;
5625 >            super(p, b, i, f, t); this.nextRight = nextRight;
5626              this.transformer = transformer;
5627              this.basis = basis; this.reducer = reducer;
5628          }
5629 <        @SuppressWarnings("unchecked") public final boolean exec() {
5630 <            final ObjectToDouble<Map.Entry<K,V>> transformer =
5631 <                this.transformer;
5632 <            final DoubleByDoubleToDouble reducer = this.reducer;
5633 <            if (transformer == null || reducer == null)
5634 <                return abortOnNullFunction();
5635 <            try {
5636 <                final double id = this.basis;
5637 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5638 <                    do {} while (!casPending(c = pending, c+1));
5629 >        public final Double getRawResult() { return result; }
5630 >        public final void compute() {
5631 >            final ObjectToDouble<Map.Entry<K,V>> transformer;
5632 >            final DoubleByDoubleToDouble reducer;
5633 >            if ((transformer = this.transformer) != null &&
5634 >                (reducer = this.reducer) != null) {
5635 >                double r = this.basis;
5636 >                for (int i = baseIndex, f, h; batch > 0 &&
5637 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5638 >                    addToPendingCount(1);
5639                      (rights = new MapReduceEntriesToDoubleTask<K,V>
5640 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5640 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5641 >                      rights, transformer, r, reducer)).fork();
5642                  }
5643 <                double r = id;
5644 <                Object v;
6553 <                while ((v = advance()) != null)
6554 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
5643 >                for (Node<K,V> p; (p = advance()) != null; )
5644 >                    r = reducer.apply(r, transformer.apply(p));
5645                  result = r;
5646 <                for (MapReduceEntriesToDoubleTask<K,V> t = this, s;;) {
5647 <                    int c; BulkTask<K,V,?> par;
5648 <                    if ((c = t.pending) == 0) {
5649 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5650 <                            t.result = reducer.apply(t.result, s.result);
5651 <                        }
5652 <                        if ((par = t.parent) == null ||
5653 <                            !(par instanceof MapReduceEntriesToDoubleTask)) {
6564 <                            t.quietlyComplete();
6565 <                            break;
6566 <                        }
6567 <                        t = (MapReduceEntriesToDoubleTask<K,V>)par;
5646 >                CountedCompleter<?> c;
5647 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5648 >                    @SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5649 >                        t = (MapReduceEntriesToDoubleTask<K,V>)c,
5650 >                        s = t.rights;
5651 >                    while (s != null) {
5652 >                        t.result = reducer.apply(t.result, s.result);
5653 >                        s = t.rights = s.nextRight;
5654                      }
6569                    else if (t.casPending(c, c - 1))
6570                        break;
5655                  }
6572            } catch (Throwable ex) {
6573                return tryCompleteComputation(ex);
6574            }
6575            MapReduceEntriesToDoubleTask<K,V> s = rights;
6576            if (s != null && !inForkJoinPool()) {
6577                do  {
6578                    if (s.tryUnfork())
6579                        s.exec();
6580                } while ((s = s.nextRight) != null);
5656              }
6582            return false;
5657          }
6584        public final Double getRawResult() { return result; }
5658      }
5659  
5660 <    @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
5660 >    @SuppressWarnings("serial")
5661 >    static final class MapReduceMappingsToDoubleTask<K,V>
5662          extends BulkTask<K,V,Double> {
5663          final ObjectByObjectToDouble<? super K, ? super V> transformer;
5664          final DoubleByDoubleToDouble reducer;
# Line 6592 | Line 5666 | public class ConcurrentHashMapV8<K, V>
5666          double result;
5667          MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5668          MapReduceMappingsToDoubleTask
5669 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5669 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5670               MapReduceMappingsToDoubleTask<K,V> nextRight,
5671               ObjectByObjectToDouble<? super K, ? super V> transformer,
5672               double basis,
5673               DoubleByDoubleToDouble reducer) {
5674 <            super(m, p, b); this.nextRight = nextRight;
5674 >            super(p, b, i, f, t); this.nextRight = nextRight;
5675              this.transformer = transformer;
5676              this.basis = basis; this.reducer = reducer;
5677          }
5678 <        @SuppressWarnings("unchecked") public final boolean exec() {
5679 <            final ObjectByObjectToDouble<? super K, ? super V> transformer =
5680 <                this.transformer;
5681 <            final DoubleByDoubleToDouble reducer = this.reducer;
5682 <            if (transformer == null || reducer == null)
5683 <                return abortOnNullFunction();
5684 <            try {
5685 <                final double id = this.basis;
5686 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5687 <                    do {} while (!casPending(c = pending, c+1));
5678 >        public final Double getRawResult() { return result; }
5679 >        public final void compute() {
5680 >            final ObjectByObjectToDouble<? super K, ? super V> transformer;
5681 >            final DoubleByDoubleToDouble reducer;
5682 >            if ((transformer = this.transformer) != null &&
5683 >                (reducer = this.reducer) != null) {
5684 >                double r = this.basis;
5685 >                for (int i = baseIndex, f, h; batch > 0 &&
5686 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5687 >                    addToPendingCount(1);
5688                      (rights = new MapReduceMappingsToDoubleTask<K,V>
5689 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5689 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5690 >                      rights, transformer, r, reducer)).fork();
5691                  }
5692 <                double r = id;
5693 <                Object v;
6619 <                while ((v = advance()) != null)
6620 <                    r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
5692 >                for (Node<K,V> p; (p = advance()) != null; )
5693 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
5694                  result = r;
5695 <                for (MapReduceMappingsToDoubleTask<K,V> t = this, s;;) {
5696 <                    int c; BulkTask<K,V,?> par;
5697 <                    if ((c = t.pending) == 0) {
5698 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5699 <                            t.result = reducer.apply(t.result, s.result);
5700 <                        }
5701 <                        if ((par = t.parent) == null ||
5702 <                            !(par instanceof MapReduceMappingsToDoubleTask)) {
6630 <                            t.quietlyComplete();
6631 <                            break;
6632 <                        }
6633 <                        t = (MapReduceMappingsToDoubleTask<K,V>)par;
5695 >                CountedCompleter<?> c;
5696 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5697 >                    @SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5698 >                        t = (MapReduceMappingsToDoubleTask<K,V>)c,
5699 >                        s = t.rights;
5700 >                    while (s != null) {
5701 >                        t.result = reducer.apply(t.result, s.result);
5702 >                        s = t.rights = s.nextRight;
5703                      }
6635                    else if (t.casPending(c, c - 1))
6636                        break;
5704                  }
6638            } catch (Throwable ex) {
6639                return tryCompleteComputation(ex);
6640            }
6641            MapReduceMappingsToDoubleTask<K,V> s = rights;
6642            if (s != null && !inForkJoinPool()) {
6643                do  {
6644                    if (s.tryUnfork())
6645                        s.exec();
6646                } while ((s = s.nextRight) != null);
5705              }
6648            return false;
5706          }
6650        public final Double getRawResult() { return result; }
5707      }
5708  
5709 <    @SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
5709 >    @SuppressWarnings("serial")
5710 >    static final class MapReduceKeysToLongTask<K,V>
5711          extends BulkTask<K,V,Long> {
5712          final ObjectToLong<? super K> transformer;
5713          final LongByLongToLong reducer;
# Line 6658 | Line 5715 | public class ConcurrentHashMapV8<K, V>
5715          long result;
5716          MapReduceKeysToLongTask<K,V> rights, nextRight;
5717          MapReduceKeysToLongTask
5718 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5718 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5719               MapReduceKeysToLongTask<K,V> nextRight,
5720               ObjectToLong<? super K> transformer,
5721               long basis,
5722               LongByLongToLong reducer) {
5723 <            super(m, p, b); this.nextRight = nextRight;
5723 >            super(p, b, i, f, t); this.nextRight = nextRight;
5724              this.transformer = transformer;
5725              this.basis = basis; this.reducer = reducer;
5726          }
5727 <        @SuppressWarnings("unchecked") public final boolean exec() {
5728 <            final ObjectToLong<? super K> transformer =
5729 <                this.transformer;
5730 <            final LongByLongToLong reducer = this.reducer;
5731 <            if (transformer == null || reducer == null)
5732 <                return abortOnNullFunction();
5733 <            try {
5734 <                final long id = this.basis;
5735 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5736 <                    do {} while (!casPending(c = pending, c+1));
5727 >        public final Long getRawResult() { return result; }
5728 >        public final void compute() {
5729 >            final ObjectToLong<? super K> transformer;
5730 >            final LongByLongToLong reducer;
5731 >            if ((transformer = this.transformer) != null &&
5732 >                (reducer = this.reducer) != null) {
5733 >                long r = this.basis;
5734 >                for (int i = baseIndex, f, h; batch > 0 &&
5735 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5736 >                    addToPendingCount(1);
5737                      (rights = new MapReduceKeysToLongTask<K,V>
5738 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5738 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5739 >                      rights, transformer, r, reducer)).fork();
5740                  }
5741 <                long r = id;
5742 <                while (advance() != null)
6685 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5741 >                for (Node<K,V> p; (p = advance()) != null; )
5742 >                    r = reducer.apply(r, transformer.apply(p.key));
5743                  result = r;
5744 <                for (MapReduceKeysToLongTask<K,V> t = this, s;;) {
5745 <                    int c; BulkTask<K,V,?> par;
5746 <                    if ((c = t.pending) == 0) {
5747 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5748 <                            t.result = reducer.apply(t.result, s.result);
5749 <                        }
5750 <                        if ((par = t.parent) == null ||
5751 <                            !(par instanceof MapReduceKeysToLongTask)) {
6695 <                            t.quietlyComplete();
6696 <                            break;
6697 <                        }
6698 <                        t = (MapReduceKeysToLongTask<K,V>)par;
5744 >                CountedCompleter<?> c;
5745 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5746 >                    @SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5747 >                        t = (MapReduceKeysToLongTask<K,V>)c,
5748 >                        s = t.rights;
5749 >                    while (s != null) {
5750 >                        t.result = reducer.apply(t.result, s.result);
5751 >                        s = t.rights = s.nextRight;
5752                      }
6700                    else if (t.casPending(c, c - 1))
6701                        break;
5753                  }
6703            } catch (Throwable ex) {
6704                return tryCompleteComputation(ex);
6705            }
6706            MapReduceKeysToLongTask<K,V> s = rights;
6707            if (s != null && !inForkJoinPool()) {
6708                do  {
6709                    if (s.tryUnfork())
6710                        s.exec();
6711                } while ((s = s.nextRight) != null);
5754              }
6713            return false;
5755          }
6715        public final Long getRawResult() { return result; }
5756      }
5757  
5758 <    @SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
5758 >    @SuppressWarnings("serial")
5759 >    static final class MapReduceValuesToLongTask<K,V>
5760          extends BulkTask<K,V,Long> {
5761          final ObjectToLong<? super V> transformer;
5762          final LongByLongToLong reducer;
# Line 6723 | Line 5764 | public class ConcurrentHashMapV8<K, V>
5764          long result;
5765          MapReduceValuesToLongTask<K,V> rights, nextRight;
5766          MapReduceValuesToLongTask
5767 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5767 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5768               MapReduceValuesToLongTask<K,V> nextRight,
5769               ObjectToLong<? super V> transformer,
5770               long basis,
5771               LongByLongToLong reducer) {
5772 <            super(m, p, b); this.nextRight = nextRight;
5772 >            super(p, b, i, f, t); this.nextRight = nextRight;
5773              this.transformer = transformer;
5774              this.basis = basis; this.reducer = reducer;
5775          }
5776 <        @SuppressWarnings("unchecked") public final boolean exec() {
5777 <            final ObjectToLong<? super V> transformer =
5778 <                this.transformer;
5779 <            final LongByLongToLong reducer = this.reducer;
5780 <            if (transformer == null || reducer == null)
5781 <                return abortOnNullFunction();
5782 <            try {
5783 <                final long id = this.basis;
5784 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5785 <                    do {} while (!casPending(c = pending, c+1));
5776 >        public final Long getRawResult() { return result; }
5777 >        public final void compute() {
5778 >            final ObjectToLong<? super V> transformer;
5779 >            final LongByLongToLong reducer;
5780 >            if ((transformer = this.transformer) != null &&
5781 >                (reducer = this.reducer) != null) {
5782 >                long r = this.basis;
5783 >                for (int i = baseIndex, f, h; batch > 0 &&
5784 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5785 >                    addToPendingCount(1);
5786                      (rights = new MapReduceValuesToLongTask<K,V>
5787 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5787 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5788 >                      rights, transformer, r, reducer)).fork();
5789                  }
5790 <                long r = id;
5791 <                Object v;
6750 <                while ((v = advance()) != null)
6751 <                    r = reducer.apply(r, transformer.apply((V)v));
5790 >                for (Node<K,V> p; (p = advance()) != null; )
5791 >                    r = reducer.apply(r, transformer.apply(p.val));
5792                  result = r;
5793 <                for (MapReduceValuesToLongTask<K,V> t = this, s;;) {
5794 <                    int c; BulkTask<K,V,?> par;
5795 <                    if ((c = t.pending) == 0) {
5796 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5797 <                            t.result = reducer.apply(t.result, s.result);
5798 <                        }
5799 <                        if ((par = t.parent) == null ||
5800 <                            !(par instanceof MapReduceValuesToLongTask)) {
6761 <                            t.quietlyComplete();
6762 <                            break;
6763 <                        }
6764 <                        t = (MapReduceValuesToLongTask<K,V>)par;
5793 >                CountedCompleter<?> c;
5794 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5795 >                    @SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5796 >                        t = (MapReduceValuesToLongTask<K,V>)c,
5797 >                        s = t.rights;
5798 >                    while (s != null) {
5799 >                        t.result = reducer.apply(t.result, s.result);
5800 >                        s = t.rights = s.nextRight;
5801                      }
6766                    else if (t.casPending(c, c - 1))
6767                        break;
5802                  }
6769            } catch (Throwable ex) {
6770                return tryCompleteComputation(ex);
5803              }
6772            MapReduceValuesToLongTask<K,V> s = rights;
6773            if (s != null && !inForkJoinPool()) {
6774                do  {
6775                    if (s.tryUnfork())
6776                        s.exec();
6777                } while ((s = s.nextRight) != null);
6778            }
6779            return false;
5804          }
6781        public final Long getRawResult() { return result; }
5805      }
5806  
5807 <    @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
5807 >    @SuppressWarnings("serial")
5808 >    static final class MapReduceEntriesToLongTask<K,V>
5809          extends BulkTask<K,V,Long> {
5810          final ObjectToLong<Map.Entry<K,V>> transformer;
5811          final LongByLongToLong reducer;
# Line 6789 | Line 5813 | public class ConcurrentHashMapV8<K, V>
5813          long result;
5814          MapReduceEntriesToLongTask<K,V> rights, nextRight;
5815          MapReduceEntriesToLongTask
5816 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5816 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5817               MapReduceEntriesToLongTask<K,V> nextRight,
5818               ObjectToLong<Map.Entry<K,V>> transformer,
5819               long basis,
5820               LongByLongToLong reducer) {
5821 <            super(m, p, b); this.nextRight = nextRight;
5821 >            super(p, b, i, f, t); this.nextRight = nextRight;
5822              this.transformer = transformer;
5823              this.basis = basis; this.reducer = reducer;
5824          }
5825 <        @SuppressWarnings("unchecked") public final boolean exec() {
5826 <            final ObjectToLong<Map.Entry<K,V>> transformer =
5827 <                this.transformer;
5828 <            final LongByLongToLong reducer = this.reducer;
5829 <            if (transformer == null || reducer == null)
5830 <                return abortOnNullFunction();
5831 <            try {
5832 <                final long id = this.basis;
5833 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5834 <                    do {} while (!casPending(c = pending, c+1));
5825 >        public final Long getRawResult() { return result; }
5826 >        public final void compute() {
5827 >            final ObjectToLong<Map.Entry<K,V>> transformer;
5828 >            final LongByLongToLong reducer;
5829 >            if ((transformer = this.transformer) != null &&
5830 >                (reducer = this.reducer) != null) {
5831 >                long r = this.basis;
5832 >                for (int i = baseIndex, f, h; batch > 0 &&
5833 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5834 >                    addToPendingCount(1);
5835                      (rights = new MapReduceEntriesToLongTask<K,V>
5836 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5836 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5837 >                      rights, transformer, r, reducer)).fork();
5838                  }
5839 <                long r = id;
5840 <                Object v;
6816 <                while ((v = advance()) != null)
6817 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
5839 >                for (Node<K,V> p; (p = advance()) != null; )
5840 >                    r = reducer.apply(r, transformer.apply(p));
5841                  result = r;
5842 <                for (MapReduceEntriesToLongTask<K,V> t = this, s;;) {
5843 <                    int c; BulkTask<K,V,?> par;
5844 <                    if ((c = t.pending) == 0) {
5845 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5846 <                            t.result = reducer.apply(t.result, s.result);
5847 <                        }
5848 <                        if ((par = t.parent) == null ||
5849 <                            !(par instanceof MapReduceEntriesToLongTask)) {
6827 <                            t.quietlyComplete();
6828 <                            break;
6829 <                        }
6830 <                        t = (MapReduceEntriesToLongTask<K,V>)par;
5842 >                CountedCompleter<?> c;
5843 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5844 >                    @SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5845 >                        t = (MapReduceEntriesToLongTask<K,V>)c,
5846 >                        s = t.rights;
5847 >                    while (s != null) {
5848 >                        t.result = reducer.apply(t.result, s.result);
5849 >                        s = t.rights = s.nextRight;
5850                      }
6832                    else if (t.casPending(c, c - 1))
6833                        break;
5851                  }
6835            } catch (Throwable ex) {
6836                return tryCompleteComputation(ex);
6837            }
6838            MapReduceEntriesToLongTask<K,V> s = rights;
6839            if (s != null && !inForkJoinPool()) {
6840                do  {
6841                    if (s.tryUnfork())
6842                        s.exec();
6843                } while ((s = s.nextRight) != null);
5852              }
6845            return false;
5853          }
6847        public final Long getRawResult() { return result; }
5854      }
5855  
5856 <    @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
5856 >    @SuppressWarnings("serial")
5857 >    static final class MapReduceMappingsToLongTask<K,V>
5858          extends BulkTask<K,V,Long> {
5859          final ObjectByObjectToLong<? super K, ? super V> transformer;
5860          final LongByLongToLong reducer;
# Line 6855 | Line 5862 | public class ConcurrentHashMapV8<K, V>
5862          long result;
5863          MapReduceMappingsToLongTask<K,V> rights, nextRight;
5864          MapReduceMappingsToLongTask
5865 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5865 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5866               MapReduceMappingsToLongTask<K,V> nextRight,
5867               ObjectByObjectToLong<? super K, ? super V> transformer,
5868               long basis,
5869               LongByLongToLong reducer) {
5870 <            super(m, p, b); this.nextRight = nextRight;
5870 >            super(p, b, i, f, t); this.nextRight = nextRight;
5871              this.transformer = transformer;
5872              this.basis = basis; this.reducer = reducer;
5873          }
5874 <        @SuppressWarnings("unchecked") public final boolean exec() {
5875 <            final ObjectByObjectToLong<? super K, ? super V> transformer =
5876 <                this.transformer;
5877 <            final LongByLongToLong reducer = this.reducer;
5878 <            if (transformer == null || reducer == null)
5879 <                return abortOnNullFunction();
5880 <            try {
5881 <                final long id = this.basis;
5882 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5883 <                    do {} while (!casPending(c = pending, c+1));
5874 >        public final Long getRawResult() { return result; }
5875 >        public final void compute() {
5876 >            final ObjectByObjectToLong<? super K, ? super V> transformer;
5877 >            final LongByLongToLong reducer;
5878 >            if ((transformer = this.transformer) != null &&
5879 >                (reducer = this.reducer) != null) {
5880 >                long r = this.basis;
5881 >                for (int i = baseIndex, f, h; batch > 0 &&
5882 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5883 >                    addToPendingCount(1);
5884                      (rights = new MapReduceMappingsToLongTask<K,V>
5885 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5885 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5886 >                      rights, transformer, r, reducer)).fork();
5887                  }
5888 <                long r = id;
5889 <                Object v;
6882 <                while ((v = advance()) != null)
6883 <                    r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
5888 >                for (Node<K,V> p; (p = advance()) != null; )
5889 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
5890                  result = r;
5891 <                for (MapReduceMappingsToLongTask<K,V> t = this, s;;) {
5892 <                    int c; BulkTask<K,V,?> par;
5893 <                    if ((c = t.pending) == 0) {
5894 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5895 <                            t.result = reducer.apply(t.result, s.result);
5896 <                        }
5897 <                        if ((par = t.parent) == null ||
5898 <                            !(par instanceof MapReduceMappingsToLongTask)) {
6893 <                            t.quietlyComplete();
6894 <                            break;
6895 <                        }
6896 <                        t = (MapReduceMappingsToLongTask<K,V>)par;
5891 >                CountedCompleter<?> c;
5892 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5893 >                    @SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5894 >                        t = (MapReduceMappingsToLongTask<K,V>)c,
5895 >                        s = t.rights;
5896 >                    while (s != null) {
5897 >                        t.result = reducer.apply(t.result, s.result);
5898 >                        s = t.rights = s.nextRight;
5899                      }
6898                    else if (t.casPending(c, c - 1))
6899                        break;
5900                  }
6901            } catch (Throwable ex) {
6902                return tryCompleteComputation(ex);
6903            }
6904            MapReduceMappingsToLongTask<K,V> s = rights;
6905            if (s != null && !inForkJoinPool()) {
6906                do  {
6907                    if (s.tryUnfork())
6908                        s.exec();
6909                } while ((s = s.nextRight) != null);
5901              }
6911            return false;
5902          }
6913        public final Long getRawResult() { return result; }
5903      }
5904  
5905 <    @SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
5905 >    @SuppressWarnings("serial")
5906 >    static final class MapReduceKeysToIntTask<K,V>
5907          extends BulkTask<K,V,Integer> {
5908          final ObjectToInt<? super K> transformer;
5909          final IntByIntToInt reducer;
# Line 6921 | Line 5911 | public class ConcurrentHashMapV8<K, V>
5911          int result;
5912          MapReduceKeysToIntTask<K,V> rights, nextRight;
5913          MapReduceKeysToIntTask
5914 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5914 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5915               MapReduceKeysToIntTask<K,V> nextRight,
5916               ObjectToInt<? super K> transformer,
5917               int basis,
5918               IntByIntToInt reducer) {
5919 <            super(m, p, b); this.nextRight = nextRight;
5919 >            super(p, b, i, f, t); this.nextRight = nextRight;
5920              this.transformer = transformer;
5921              this.basis = basis; this.reducer = reducer;
5922          }
5923 <        @SuppressWarnings("unchecked") public final boolean exec() {
5924 <            final ObjectToInt<? super K> transformer =
5925 <                this.transformer;
5926 <            final IntByIntToInt reducer = this.reducer;
5927 <            if (transformer == null || reducer == null)
5928 <                return abortOnNullFunction();
5929 <            try {
5930 <                final int id = this.basis;
5931 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5932 <                    do {} while (!casPending(c = pending, c+1));
5923 >        public final Integer getRawResult() { return result; }
5924 >        public final void compute() {
5925 >            final ObjectToInt<? super K> transformer;
5926 >            final IntByIntToInt reducer;
5927 >            if ((transformer = this.transformer) != null &&
5928 >                (reducer = this.reducer) != null) {
5929 >                int r = this.basis;
5930 >                for (int i = baseIndex, f, h; batch > 0 &&
5931 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5932 >                    addToPendingCount(1);
5933                      (rights = new MapReduceKeysToIntTask<K,V>
5934 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5934 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5935 >                      rights, transformer, r, reducer)).fork();
5936                  }
5937 <                int r = id;
5938 <                while (advance() != null)
6948 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5937 >                for (Node<K,V> p; (p = advance()) != null; )
5938 >                    r = reducer.apply(r, transformer.apply(p.key));
5939                  result = r;
5940 <                for (MapReduceKeysToIntTask<K,V> t = this, s;;) {
5941 <                    int c; BulkTask<K,V,?> par;
5942 <                    if ((c = t.pending) == 0) {
5943 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5944 <                            t.result = reducer.apply(t.result, s.result);
5945 <                        }
5946 <                        if ((par = t.parent) == null ||
5947 <                            !(par instanceof MapReduceKeysToIntTask)) {
6958 <                            t.quietlyComplete();
6959 <                            break;
6960 <                        }
6961 <                        t = (MapReduceKeysToIntTask<K,V>)par;
5940 >                CountedCompleter<?> c;
5941 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5942 >                    @SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5943 >                        t = (MapReduceKeysToIntTask<K,V>)c,
5944 >                        s = t.rights;
5945 >                    while (s != null) {
5946 >                        t.result = reducer.apply(t.result, s.result);
5947 >                        s = t.rights = s.nextRight;
5948                      }
6963                    else if (t.casPending(c, c - 1))
6964                        break;
5949                  }
6966            } catch (Throwable ex) {
6967                return tryCompleteComputation(ex);
5950              }
6969            MapReduceKeysToIntTask<K,V> s = rights;
6970            if (s != null && !inForkJoinPool()) {
6971                do  {
6972                    if (s.tryUnfork())
6973                        s.exec();
6974                } while ((s = s.nextRight) != null);
6975            }
6976            return false;
5951          }
6978        public final Integer getRawResult() { return result; }
5952      }
5953  
5954 <    @SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
5954 >    @SuppressWarnings("serial")
5955 >    static final class MapReduceValuesToIntTask<K,V>
5956          extends BulkTask<K,V,Integer> {
5957          final ObjectToInt<? super V> transformer;
5958          final IntByIntToInt reducer;
# Line 6986 | Line 5960 | public class ConcurrentHashMapV8<K, V>
5960          int result;
5961          MapReduceValuesToIntTask<K,V> rights, nextRight;
5962          MapReduceValuesToIntTask
5963 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
5963 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5964               MapReduceValuesToIntTask<K,V> nextRight,
5965               ObjectToInt<? super V> transformer,
5966               int basis,
5967               IntByIntToInt reducer) {
5968 <            super(m, p, b); this.nextRight = nextRight;
5968 >            super(p, b, i, f, t); this.nextRight = nextRight;
5969              this.transformer = transformer;
5970              this.basis = basis; this.reducer = reducer;
5971          }
5972 <        @SuppressWarnings("unchecked") public final boolean exec() {
5973 <            final ObjectToInt<? super V> transformer =
5974 <                this.transformer;
5975 <            final IntByIntToInt reducer = this.reducer;
5976 <            if (transformer == null || reducer == null)
5977 <                return abortOnNullFunction();
5978 <            try {
5979 <                final int id = this.basis;
5980 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5981 <                    do {} while (!casPending(c = pending, c+1));
5972 >        public final Integer getRawResult() { return result; }
5973 >        public final void compute() {
5974 >            final ObjectToInt<? super V> transformer;
5975 >            final IntByIntToInt reducer;
5976 >            if ((transformer = this.transformer) != null &&
5977 >                (reducer = this.reducer) != null) {
5978 >                int r = this.basis;
5979 >                for (int i = baseIndex, f, h; batch > 0 &&
5980 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5981 >                    addToPendingCount(1);
5982                      (rights = new MapReduceValuesToIntTask<K,V>
5983 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
5983 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5984 >                      rights, transformer, r, reducer)).fork();
5985                  }
5986 <                int r = id;
5987 <                Object v;
7013 <                while ((v = advance()) != null)
7014 <                    r = reducer.apply(r, transformer.apply((V)v));
5986 >                for (Node<K,V> p; (p = advance()) != null; )
5987 >                    r = reducer.apply(r, transformer.apply(p.val));
5988                  result = r;
5989 <                for (MapReduceValuesToIntTask<K,V> t = this, s;;) {
5990 <                    int c; BulkTask<K,V,?> par;
5991 <                    if ((c = t.pending) == 0) {
5992 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5993 <                            t.result = reducer.apply(t.result, s.result);
5994 <                        }
5995 <                        if ((par = t.parent) == null ||
5996 <                            !(par instanceof MapReduceValuesToIntTask)) {
7024 <                            t.quietlyComplete();
7025 <                            break;
7026 <                        }
7027 <                        t = (MapReduceValuesToIntTask<K,V>)par;
5989 >                CountedCompleter<?> c;
5990 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
5991 >                    @SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5992 >                        t = (MapReduceValuesToIntTask<K,V>)c,
5993 >                        s = t.rights;
5994 >                    while (s != null) {
5995 >                        t.result = reducer.apply(t.result, s.result);
5996 >                        s = t.rights = s.nextRight;
5997                      }
7029                    else if (t.casPending(c, c - 1))
7030                        break;
5998                  }
7032            } catch (Throwable ex) {
7033                return tryCompleteComputation(ex);
5999              }
7035            MapReduceValuesToIntTask<K,V> s = rights;
7036            if (s != null && !inForkJoinPool()) {
7037                do  {
7038                    if (s.tryUnfork())
7039                        s.exec();
7040                } while ((s = s.nextRight) != null);
7041            }
7042            return false;
6000          }
7044        public final Integer getRawResult() { return result; }
6001      }
6002  
6003 <    @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6003 >    @SuppressWarnings("serial")
6004 >    static final class MapReduceEntriesToIntTask<K,V>
6005          extends BulkTask<K,V,Integer> {
6006          final ObjectToInt<Map.Entry<K,V>> transformer;
6007          final IntByIntToInt reducer;
# Line 7052 | Line 6009 | public class ConcurrentHashMapV8<K, V>
6009          int result;
6010          MapReduceEntriesToIntTask<K,V> rights, nextRight;
6011          MapReduceEntriesToIntTask
6012 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
6012 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6013               MapReduceEntriesToIntTask<K,V> nextRight,
6014               ObjectToInt<Map.Entry<K,V>> transformer,
6015               int basis,
6016               IntByIntToInt reducer) {
6017 <            super(m, p, b); this.nextRight = nextRight;
6017 >            super(p, b, i, f, t); this.nextRight = nextRight;
6018              this.transformer = transformer;
6019              this.basis = basis; this.reducer = reducer;
6020          }
6021 <        @SuppressWarnings("unchecked") public final boolean exec() {
6022 <            final ObjectToInt<Map.Entry<K,V>> transformer =
6023 <                this.transformer;
6024 <            final IntByIntToInt reducer = this.reducer;
6025 <            if (transformer == null || reducer == null)
6026 <                return abortOnNullFunction();
6027 <            try {
6028 <                final int id = this.basis;
6029 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6030 <                    do {} while (!casPending(c = pending, c+1));
6021 >        public final Integer getRawResult() { return result; }
6022 >        public final void compute() {
6023 >            final ObjectToInt<Map.Entry<K,V>> transformer;
6024 >            final IntByIntToInt reducer;
6025 >            if ((transformer = this.transformer) != null &&
6026 >                (reducer = this.reducer) != null) {
6027 >                int r = this.basis;
6028 >                for (int i = baseIndex, f, h; batch > 0 &&
6029 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
6030 >                    addToPendingCount(1);
6031                      (rights = new MapReduceEntriesToIntTask<K,V>
6032 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6032 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
6033 >                      rights, transformer, r, reducer)).fork();
6034                  }
6035 <                int r = id;
6036 <                Object v;
7079 <                while ((v = advance()) != null)
7080 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6035 >                for (Node<K,V> p; (p = advance()) != null; )
6036 >                    r = reducer.apply(r, transformer.apply(p));
6037                  result = r;
6038 <                for (MapReduceEntriesToIntTask<K,V> t = this, s;;) {
6039 <                    int c; BulkTask<K,V,?> par;
6040 <                    if ((c = t.pending) == 0) {
6041 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6042 <                            t.result = reducer.apply(t.result, s.result);
6043 <                        }
6044 <                        if ((par = t.parent) == null ||
6045 <                            !(par instanceof MapReduceEntriesToIntTask)) {
7090 <                            t.quietlyComplete();
7091 <                            break;
7092 <                        }
7093 <                        t = (MapReduceEntriesToIntTask<K,V>)par;
6038 >                CountedCompleter<?> c;
6039 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
6040 >                    @SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
6041 >                        t = (MapReduceEntriesToIntTask<K,V>)c,
6042 >                        s = t.rights;
6043 >                    while (s != null) {
6044 >                        t.result = reducer.apply(t.result, s.result);
6045 >                        s = t.rights = s.nextRight;
6046                      }
7095                    else if (t.casPending(c, c - 1))
7096                        break;
6047                  }
7098            } catch (Throwable ex) {
7099                return tryCompleteComputation(ex);
7100            }
7101            MapReduceEntriesToIntTask<K,V> s = rights;
7102            if (s != null && !inForkJoinPool()) {
7103                do  {
7104                    if (s.tryUnfork())
7105                        s.exec();
7106                } while ((s = s.nextRight) != null);
6048              }
7108            return false;
6049          }
7110        public final Integer getRawResult() { return result; }
6050      }
6051  
6052 <    @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6052 >    @SuppressWarnings("serial")
6053 >    static final class MapReduceMappingsToIntTask<K,V>
6054          extends BulkTask<K,V,Integer> {
6055          final ObjectByObjectToInt<? super K, ? super V> transformer;
6056          final IntByIntToInt reducer;
# Line 7118 | Line 6058 | public class ConcurrentHashMapV8<K, V>
6058          int result;
6059          MapReduceMappingsToIntTask<K,V> rights, nextRight;
6060          MapReduceMappingsToIntTask
6061 <            (ConcurrentHashMapV8<K,V> m, BulkTask<K,V,?> p, int b,
6062 <             MapReduceMappingsToIntTask<K,V> rights,
6061 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6062 >             MapReduceMappingsToIntTask<K,V> nextRight,
6063               ObjectByObjectToInt<? super K, ? super V> transformer,
6064               int basis,
6065               IntByIntToInt reducer) {
6066 <            super(m, p, b); this.nextRight = nextRight;
6066 >            super(p, b, i, f, t); this.nextRight = nextRight;
6067              this.transformer = transformer;
6068              this.basis = basis; this.reducer = reducer;
6069          }
6070 <        @SuppressWarnings("unchecked") public final boolean exec() {
6071 <            final ObjectByObjectToInt<? super K, ? super V> transformer =
6072 <                this.transformer;
6073 <            final IntByIntToInt reducer = this.reducer;
6074 <            if (transformer == null || reducer == null)
6075 <                return abortOnNullFunction();
6076 <            try {
6077 <                final int id = this.basis;
6078 <                for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6079 <                    do {} while (!casPending(c = pending, c+1));
6070 >        public final Integer getRawResult() { return result; }
6071 >        public final void compute() {
6072 >            final ObjectByObjectToInt<? super K, ? super V> transformer;
6073 >            final IntByIntToInt reducer;
6074 >            if ((transformer = this.transformer) != null &&
6075 >                (reducer = this.reducer) != null) {
6076 >                int r = this.basis;
6077 >                for (int i = baseIndex, f, h; batch > 0 &&
6078 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
6079 >                    addToPendingCount(1);
6080                      (rights = new MapReduceMappingsToIntTask<K,V>
6081 <                     (map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6081 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
6082 >                      rights, transformer, r, reducer)).fork();
6083                  }
6084 <                int r = id;
6085 <                Object v;
7145 <                while ((v = advance()) != null)
7146 <                    r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6084 >                for (Node<K,V> p; (p = advance()) != null; )
6085 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
6086                  result = r;
6087 <                for (MapReduceMappingsToIntTask<K,V> t = this, s;;) {
6088 <                    int c; BulkTask<K,V,?> par;
6089 <                    if ((c = t.pending) == 0) {
6090 <                        for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6091 <                            t.result = reducer.apply(t.result, s.result);
6087 >                CountedCompleter<?> c;
6088 >                for (c = firstComplete(); c != null; c = c.nextComplete()) {
6089 >                    @SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6090 >                        t = (MapReduceMappingsToIntTask<K,V>)c,
6091 >                        s = t.rights;
6092 >                    while (s != null) {
6093 >                        t.result = reducer.apply(t.result, s.result);
6094 >                        s = t.rights = s.nextRight;
6095 >                    }
6096 >                }
6097 >            }
6098 >        }
6099 >    }
6100 >
6101 >    /* ---------------- Counters -------------- */
6102 >
6103 >    // Adapted from LongAdder and Striped64.
6104 >    // See their internal docs for explanation.
6105 >
6106 >    // A padded cell for distributing counts
6107 >    static final class CounterCell {
6108 >        volatile long p0, p1, p2, p3, p4, p5, p6;
6109 >        volatile long value;
6110 >        volatile long q0, q1, q2, q3, q4, q5, q6;
6111 >        CounterCell(long x) { value = x; }
6112 >    }
6113 >
6114 >    /**
6115 >     * Holder for the thread-local hash code determining which
6116 >     * CounterCell to use. The code is initialized via the
6117 >     * counterHashCodeGenerator, but may be moved upon collisions.
6118 >     */
6119 >    static final class CounterHashCode {
6120 >        int code;
6121 >    }
6122 >
6123 >    /**
6124 >     * Generates initial value for per-thread CounterHashCodes.
6125 >     */
6126 >    static final AtomicInteger counterHashCodeGenerator = new AtomicInteger();
6127 >
6128 >    /**
6129 >     * Increment for counterHashCodeGenerator. See class ThreadLocal
6130 >     * for explanation.
6131 >     */
6132 >    static final int SEED_INCREMENT = 0x61c88647;
6133 >
6134 >    /**
6135 >     * Per-thread counter hash codes. Shared across all instances.
6136 >     */
6137 >    static final ThreadLocal<CounterHashCode> threadCounterHashCode =
6138 >        new ThreadLocal<CounterHashCode>();
6139 >
6140 >
6141 >    final long sumCount() {
6142 >        CounterCell[] as = counterCells; CounterCell a;
6143 >        long sum = baseCount;
6144 >        if (as != null) {
6145 >            for (int i = 0; i < as.length; ++i) {
6146 >                if ((a = as[i]) != null)
6147 >                    sum += a.value;
6148 >            }
6149 >        }
6150 >        return sum;
6151 >    }
6152 >
6153 >    // See LongAdder version for explanation
6154 >    private final void fullAddCount(long x, CounterHashCode hc,
6155 >                                    boolean wasUncontended) {
6156 >        int h;
6157 >        if (hc == null) {
6158 >            hc = new CounterHashCode();
6159 >            int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT);
6160 >            h = hc.code = (s == 0) ? 1 : s; // Avoid zero
6161 >            threadCounterHashCode.set(hc);
6162 >        }
6163 >        else
6164 >            h = hc.code;
6165 >        boolean collide = false;                // True if last slot nonempty
6166 >        for (;;) {
6167 >            CounterCell[] as; CounterCell a; int n; long v;
6168 >            if ((as = counterCells) != null && (n = as.length) > 0) {
6169 >                if ((a = as[(n - 1) & h]) == null) {
6170 >                    if (cellsBusy == 0) {            // Try to attach new Cell
6171 >                        CounterCell r = new CounterCell(x); // Optimistic create
6172 >                        if (cellsBusy == 0 &&
6173 >                            U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6174 >                            boolean created = false;
6175 >                            try {               // Recheck under lock
6176 >                                CounterCell[] rs; int m, j;
6177 >                                if ((rs = counterCells) != null &&
6178 >                                    (m = rs.length) > 0 &&
6179 >                                    rs[j = (m - 1) & h] == null) {
6180 >                                    rs[j] = r;
6181 >                                    created = true;
6182 >                                }
6183 >                            } finally {
6184 >                                cellsBusy = 0;
6185 >                            }
6186 >                            if (created)
6187 >                                break;
6188 >                            continue;           // Slot is now non-empty
6189                          }
6190 <                        if ((par = t.parent) == null ||
6191 <                            !(par instanceof MapReduceMappingsToIntTask)) {
6192 <                            t.quietlyComplete();
6193 <                            break;
6190 >                    }
6191 >                    collide = false;
6192 >                }
6193 >                else if (!wasUncontended)       // CAS already known to fail
6194 >                    wasUncontended = true;      // Continue after rehash
6195 >                else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
6196 >                    break;
6197 >                else if (counterCells != as || n >= NCPU)
6198 >                    collide = false;            // At max size or stale
6199 >                else if (!collide)
6200 >                    collide = true;
6201 >                else if (cellsBusy == 0 &&
6202 >                         U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6203 >                    try {
6204 >                        if (counterCells == as) {// Expand table unless stale
6205 >                            CounterCell[] rs = new CounterCell[n << 1];
6206 >                            for (int i = 0; i < n; ++i)
6207 >                                rs[i] = as[i];
6208 >                            counterCells = rs;
6209                          }
6210 <                        t = (MapReduceMappingsToIntTask<K,V>)par;
6210 >                    } finally {
6211 >                        cellsBusy = 0;
6212                      }
6213 <                    else if (t.casPending(c, c - 1))
6214 <                        break;
6213 >                    collide = false;
6214 >                    continue;                   // Retry with expanded table
6215                  }
6216 <            } catch (Throwable ex) {
6217 <                return tryCompleteComputation(ex);
6218 <            }
6219 <            MapReduceMappingsToIntTask<K,V> s = rights;
6220 <            if (s != null && !inForkJoinPool()) {
6221 <                do  {
6222 <                    if (s.tryUnfork())
6223 <                        s.exec();
6224 <                } while ((s = s.nextRight) != null);
6216 >                h ^= h << 13;                   // Rehash
6217 >                h ^= h >>> 17;
6218 >                h ^= h << 5;
6219 >            }
6220 >            else if (cellsBusy == 0 && counterCells == as &&
6221 >                     U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6222 >                boolean init = false;
6223 >                try {                           // Initialize table
6224 >                    if (counterCells == as) {
6225 >                        CounterCell[] rs = new CounterCell[2];
6226 >                        rs[h & 1] = new CounterCell(x);
6227 >                        counterCells = rs;
6228 >                        init = true;
6229 >                    }
6230 >                } finally {
6231 >                    cellsBusy = 0;
6232 >                }
6233 >                if (init)
6234 >                    break;
6235              }
6236 <            return false;
6236 >            else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
6237 >                break;                          // Fall back on using base
6238          }
6239 <        public final Integer getRawResult() { return result; }
6239 >        hc.code = h;                            // Record index for next time
6240      }
6241  
6242      // Unsafe mechanics
6243 <    private static final sun.misc.Unsafe UNSAFE;
6244 <    private static final long counterOffset;
6245 <    private static final long sizeCtlOffset;
6243 >    private static final sun.misc.Unsafe U;
6244 >    private static final long SIZECTL;
6245 >    private static final long TRANSFERINDEX;
6246 >    private static final long BASECOUNT;
6247 >    private static final long CELLSBUSY;
6248 >    private static final long CELLVALUE;
6249      private static final long ABASE;
6250      private static final int ASHIFT;
6251  
6252      static {
7187        int ss;
6253          try {
6254 <            UNSAFE = getUnsafe();
6254 >            U = getUnsafe();
6255              Class<?> k = ConcurrentHashMapV8.class;
6256 <            counterOffset = UNSAFE.objectFieldOffset
7192 <                (k.getDeclaredField("counter"));
7193 <            sizeCtlOffset = UNSAFE.objectFieldOffset
6256 >            SIZECTL = U.objectFieldOffset
6257                  (k.getDeclaredField("sizeCtl"));
6258 <            Class<?> sc = Node[].class;
6259 <            ABASE = UNSAFE.arrayBaseOffset(sc);
6260 <            ss = UNSAFE.arrayIndexScale(sc);
6258 >            TRANSFERINDEX = U.objectFieldOffset
6259 >                (k.getDeclaredField("transferIndex"));
6260 >            BASECOUNT = U.objectFieldOffset
6261 >                (k.getDeclaredField("baseCount"));
6262 >            CELLSBUSY = U.objectFieldOffset
6263 >                (k.getDeclaredField("cellsBusy"));
6264 >            Class<?> ck = CounterCell.class;
6265 >            CELLVALUE = U.objectFieldOffset
6266 >                (ck.getDeclaredField("value"));
6267 >            Class<?> ak = Node[].class;
6268 >            ABASE = U.arrayBaseOffset(ak);
6269 >            int scale = U.arrayIndexScale(ak);
6270 >            if ((scale & (scale - 1)) != 0)
6271 >                throw new Error("data type scale not a power of two");
6272 >            ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6273          } catch (Exception e) {
6274              throw new Error(e);
6275          }
7201        if ((ss & (ss-1)) != 0)
7202            throw new Error("data type scale not a power of two");
7203        ASHIFT = 31 - Integer.numberOfLeadingZeros(ss);
6276      }
6277  
6278      /**
# Line 7213 | Line 6285 | public class ConcurrentHashMapV8<K, V>
6285      private static sun.misc.Unsafe getUnsafe() {
6286          try {
6287              return sun.misc.Unsafe.getUnsafe();
6288 <        } catch (SecurityException se) {
6289 <            try {
6290 <                return java.security.AccessController.doPrivileged
6291 <                    (new java.security
6292 <                     .PrivilegedExceptionAction<sun.misc.Unsafe>() {
6293 <                        public sun.misc.Unsafe run() throws Exception {
6294 <                            java.lang.reflect.Field f = sun.misc
6295 <                                .Unsafe.class.getDeclaredField("theUnsafe");
6296 <                            f.setAccessible(true);
6297 <                            return (sun.misc.Unsafe) f.get(null);
6298 <                        }});
6299 <            } catch (java.security.PrivilegedActionException e) {
6300 <                throw new RuntimeException("Could not initialize intrinsics",
6301 <                                           e.getCause());
6302 <            }
6288 >        } catch (SecurityException tryReflectionInstead) {}
6289 >        try {
6290 >            return java.security.AccessController.doPrivileged
6291 >            (new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() {
6292 >                public sun.misc.Unsafe run() throws Exception {
6293 >                    Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
6294 >                    for (java.lang.reflect.Field f : k.getDeclaredFields()) {
6295 >                        f.setAccessible(true);
6296 >                        Object x = f.get(null);
6297 >                        if (k.isInstance(x))
6298 >                            return k.cast(x);
6299 >                    }
6300 >                    throw new NoSuchFieldError("the Unsafe");
6301 >                }});
6302 >        } catch (java.security.PrivilegedActionException e) {
6303 >            throw new RuntimeException("Could not initialize intrinsics",
6304 >                                       e.getCause());
6305          }
6306      }
6307   }

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