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Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents):
Revision 1.92 by jsr166, Mon Jan 28 17:27:03 2013 UTC vs.
Revision 1.121 by jsr166, Sat Dec 21 21:32:34 2013 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;
20 < import java.util.AbstractCollection;
17 < import java.util.Hashtable;
18 > import java.util.Comparator;
19 > import java.util.ConcurrentModificationException;
20 > import java.util.Enumeration;
21   import java.util.HashMap;
22 + import java.util.Hashtable;
23   import java.util.Iterator;
24 < import java.util.Enumeration;
21 < import java.util.ConcurrentModificationException;
24 > import java.util.Map;
25   import java.util.NoSuchElementException;
26 + import java.util.Set;
27   import java.util.concurrent.ConcurrentMap;
24 import java.util.concurrent.locks.AbstractQueuedSynchronizer;
25 import java.util.concurrent.atomic.AtomicInteger;
28   import java.util.concurrent.atomic.AtomicReference;
29 < import java.io.Serializable;
29 > import java.util.concurrent.atomic.AtomicInteger;
30 > import java.util.concurrent.locks.LockSupport;
31 > import java.util.concurrent.locks.ReentrantLock;
32  
33   /**
34   * A hash table supporting full concurrency of retrievals and
# Line 78 | Line 82 | import java.io.Serializable;
82   * expected {@code concurrencyLevel} as an additional hint for
83   * internal sizing.  Note that using many keys with exactly the same
84   * {@code hashCode()} is a sure way to slow down performance of any
85 < * hash table.
85 > * hash table. To ameliorate impact, when keys are {@link Comparable},
86 > * this class may use comparison order among keys to help break ties.
87   *
88   * <p>A {@link Set} projection of a ConcurrentHashMapV8 may be created
89   * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
# Line 86 | Line 91 | import java.io.Serializable;
91   * mapped values are (perhaps transiently) not used or all take the
92   * same mapping value.
93   *
89 * <p>A ConcurrentHashMapV8 can be used as scalable frequency map (a
90 * form of histogram or multiset) by using {@link LongAdder} values
91 * and initializing via {@link #computeIfAbsent}. For example, to add
92 * a count to a {@code ConcurrentHashMapV8<String,LongAdder> freqs}, you
93 * can use {@code freqs.computeIfAbsent(k -> new
94 * LongAdder()).increment();}
95 *
94   * <p>This class and its views and iterators implement all of the
95   * <em>optional</em> methods of the {@link Map} and {@link Iterator}
96   * interfaces.
# Line 100 | Line 98 | import java.io.Serializable;
98   * <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
99   * does <em>not</em> allow {@code null} to be used as a key or value.
100   *
101 < * <p>ConcurrentHashMapV8s support sequential and parallel operations
102 < * bulk operations. (Parallel forms use the {@link
103 < * ForkJoinPool#commonPool()}). Tasks that may be used in other
104 < * contexts are available in class {@link ForkJoinTasks}. These
105 < * operations are designed to be safely, and often sensibly, applied
106 < * even with maps that are being concurrently updated by other
107 < * threads; for example, when computing a snapshot summary of the
108 < * values in a shared registry.  There are three kinds of operation,
109 < * each with four forms, accepting functions with Keys, Values,
110 < * Entries, and (Key, Value) arguments and/or return values. Because
111 < * the elements of a ConcurrentHashMapV8 are not ordered in any
112 < * particular way, and may be processed in different orders in
113 < * different parallel executions, the correctness of supplied
114 < * functions should not depend on any ordering, or on any other
115 < * objects or values that may transiently change while computation is
118 < * in progress; and except for forEach actions, should ideally be
119 < * side-effect-free.
101 > * <p>ConcurrentHashMapV8s support a set of sequential and parallel bulk
102 > * operations that are designed
103 > * to be safely, and often sensibly, applied even with maps that are
104 > * being concurrently updated by other threads; for example, when
105 > * computing a snapshot summary of the values in a shared registry.
106 > * There are three kinds of operation, each with four forms, accepting
107 > * functions with Keys, Values, Entries, and (Key, Value) arguments
108 > * and/or return values. Because the elements of a ConcurrentHashMapV8
109 > * are not ordered in any particular way, and may be processed in
110 > * different orders in different parallel executions, the correctness
111 > * of supplied functions should not depend on any ordering, or on any
112 > * other objects or values that may transiently change while
113 > * computation is in progress; and except for forEach actions, should
114 > * ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
115 > * objects do not support method {@code setValue}.
116   *
117   * <ul>
118   * <li> forEach: Perform a given action on each element.
# Line 143 | Line 139 | import java.io.Serializable;
139   * <li> Reductions to scalar doubles, longs, and ints, using a
140   * given basis value.</li>
141   *
146 * </li>
142   * </ul>
143 + * </li>
144   * </ul>
145   *
146 + * <p>These bulk operations accept a {@code parallelismThreshold}
147 + * argument. Methods proceed sequentially if the current map size is
148 + * estimated to be less than the given threshold. Using a value of
149 + * {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
150 + * of {@code 1} results in maximal parallelism by partitioning into
151 + * enough subtasks to fully utilize the {@link
152 + * ForkJoinPool#commonPool()} that is used for all parallel
153 + * computations. Normally, you would initially choose one of these
154 + * extreme values, and then measure performance of using in-between
155 + * values that trade off overhead versus throughput.
156 + *
157   * <p>The concurrency properties of bulk operations follow
158   * from those of ConcurrentHashMapV8: Any non-null result returned
159   * from {@code get(key)} and related access methods bears a
# Line 212 | Line 219 | import java.io.Serializable;
219   * @param <K> the type of keys maintained by this map
220   * @param <V> the type of mapped values
221   */
222 < public class ConcurrentHashMapV8<K, V>
223 <    implements ConcurrentMap<K, V>, Serializable {
222 > public class ConcurrentHashMapV8<K,V> extends AbstractMap<K,V>
223 >    implements ConcurrentMap<K,V>, Serializable {
224      private static final long serialVersionUID = 7249069246763182397L;
225  
226      /**
227 <     * A partitionable iterator. A Spliterator can be traversed
228 <     * directly, but can also be partitioned (before traversal) by
229 <     * creating another Spliterator that covers a non-overlapping
223 <     * portion of the elements, and so may be amenable to parallel
224 <     * execution.
225 <     *
226 <     * <p>This interface exports a subset of expected JDK8
227 <     * functionality.
228 <     *
229 <     * <p>Sample usage: Here is one (of the several) ways to compute
230 <     * the sum of the values held in a map using the ForkJoin
231 <     * framework. As illustrated here, Spliterators are well suited to
232 <     * designs in which a task repeatedly splits off half its work
233 <     * into forked subtasks until small enough to process directly,
234 <     * and then joins these subtasks. Variants of this style can also
235 <     * be used in completion-based designs.
236 <     *
237 <     * <pre>
238 <     * {@code ConcurrentHashMapV8<String, Long> m = ...
239 <     * // split as if have 8 * parallelism, for load balance
240 <     * int n = m.size();
241 <     * int p = aForkJoinPool.getParallelism() * 8;
242 <     * int split = (n < p)? n : p;
243 <     * long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
244 <     * // ...
245 <     * static class SumValues extends RecursiveTask<Long> {
246 <     *   final Spliterator<Long> s;
247 <     *   final int split;             // split while > 1
248 <     *   final SumValues nextJoin;    // records forked subtasks to join
249 <     *   SumValues(Spliterator<Long> s, int depth, SumValues nextJoin) {
250 <     *     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
251 <     *   }
252 <     *   public Long compute() {
253 <     *     long sum = 0;
254 <     *     SumValues subtasks = null; // fork subtasks
255 <     *     for (int s = split >>> 1; s > 0; s >>>= 1)
256 <     *       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
257 <     *     while (s.hasNext())        // directly process remaining elements
258 <     *       sum += s.next();
259 <     *     for (SumValues t = subtasks; t != null; t = t.nextJoin)
260 <     *       sum += t.join();         // collect subtask results
261 <     *     return sum;
262 <     *   }
263 <     * }
264 <     * }</pre>
227 >     * An object for traversing and partitioning elements of a source.
228 >     * This interface provides a subset of the functionality of JDK8
229 >     * java.util.Spliterator.
230       */
231 <    public static interface Spliterator<T> extends Iterator<T> {
231 >    public static interface ConcurrentHashMapSpliterator<T> {
232          /**
233 <         * Returns a Spliterator covering approximately half of the
234 <         * elements, guaranteed not to overlap with those subsequently
235 <         * returned by this Spliterator.  After invoking this method,
236 <         * the current Spliterator will <em>not</em> produce any of
272 <         * the elements of the returned Spliterator, but the two
273 <         * Spliterators together will produce all of the elements that
274 <         * would have been produced by this Spliterator had this
275 <         * method not been called. The exact number of elements
276 <         * produced by the returned Spliterator is not guaranteed, and
277 <         * may be zero (i.e., with {@code hasNext()} reporting {@code
278 <         * false}) if this Spliterator cannot be further split.
279 <         *
280 <         * @return a Spliterator covering approximately half of the
281 <         * elements
282 <         * @throws IllegalStateException if this Spliterator has
283 <         * already commenced traversing elements
233 >         * If possible, returns a new spliterator covering
234 >         * approximately one half of the elements, which will not be
235 >         * covered by this spliterator. Returns null if cannot be
236 >         * split.
237           */
238 <        Spliterator<T> split();
238 >        ConcurrentHashMapSpliterator<T> trySplit();
239 >        /**
240 >         * Returns an estimate of the number of elements covered by
241 >         * this Spliterator.
242 >         */
243 >        long estimateSize();
244 >
245 >        /** Applies the action to each untraversed element */
246 >        void forEachRemaining(Action<? super T> action);
247 >        /** If an element remains, applies the action and returns true. */
248 >        boolean tryAdvance(Action<? super T> action);
249      }
250  
251 +    // Sams
252 +    /** Interface describing a void action of one argument */
253 +    public interface Action<A> { void apply(A a); }
254 +    /** Interface describing a void action of two arguments */
255 +    public interface BiAction<A,B> { void apply(A a, B b); }
256 +    /** Interface describing a function of one argument */
257 +    public interface Fun<A,T> { T apply(A a); }
258 +    /** Interface describing a function of two arguments */
259 +    public interface BiFun<A,B,T> { T apply(A a, B b); }
260 +    /** Interface describing a function mapping its argument to a double */
261 +    public interface ObjectToDouble<A> { double apply(A a); }
262 +    /** Interface describing a function mapping its argument to a long */
263 +    public interface ObjectToLong<A> { long apply(A a); }
264 +    /** Interface describing a function mapping its argument to an int */
265 +    public interface ObjectToInt<A> {int apply(A a); }
266 +    /** Interface describing a function mapping two arguments to a double */
267 +    public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
268 +    /** Interface describing a function mapping two arguments to a long */
269 +    public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
270 +    /** Interface describing a function mapping two arguments to an int */
271 +    public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
272 +    /** Interface describing a function mapping two doubles to a double */
273 +    public interface DoubleByDoubleToDouble { double apply(double a, double b); }
274 +    /** Interface describing a function mapping two longs to a long */
275 +    public interface LongByLongToLong { long apply(long a, long b); }
276 +    /** Interface describing a function mapping two ints to an int */
277 +    public interface IntByIntToInt { int apply(int a, int b); }
278 +
279 +
280      /*
281       * Overview:
282       *
# Line 295 | Line 287 | public class ConcurrentHashMapV8<K, V>
287       * the same or better than java.util.HashMap, and to support high
288       * initial insertion rates on an empty table by many threads.
289       *
290 <     * Each key-value mapping is held in a Node.  Because Node key
291 <     * fields can contain special values, they are defined using plain
292 <     * Object types (not type "K"). This leads to a lot of explicit
293 <     * casting (and many explicit warning suppressions to tell
294 <     * compilers not to complain about it). It also allows some of the
295 <     * public methods to be factored into a smaller number of internal
296 <     * methods (although sadly not so for the five variants of
297 <     * put-related operations). The validation-based approach
298 <     * explained below leads to a lot of code sprawl because
299 <     * retry-control precludes factoring into smaller methods.
290 >     * This map usually acts as a binned (bucketed) hash table.  Each
291 >     * key-value mapping is held in a Node.  Most nodes are instances
292 >     * of the basic Node class with hash, key, value, and next
293 >     * fields. However, various subclasses exist: TreeNodes are
294 >     * arranged in balanced trees, not lists.  TreeBins hold the roots
295 >     * of sets of TreeNodes. ForwardingNodes are placed at the heads
296 >     * of bins during resizing. ReservationNodes are used as
297 >     * placeholders while establishing values in computeIfAbsent and
298 >     * related methods.  The types TreeBin, ForwardingNode, and
299 >     * ReservationNode do not hold normal user keys, values, or
300 >     * hashes, and are readily distinguishable during search etc
301 >     * because they have negative hash fields and null key and value
302 >     * fields. (These special nodes are either uncommon or transient,
303 >     * so the impact of carrying around some unused fields is
304 >     * insignificant.)
305       *
306       * The table is lazily initialized to a power-of-two size upon the
307       * first insertion.  Each bin in the table normally contains a
# Line 312 | Line 309 | public class ConcurrentHashMapV8<K, V>
309       * Table accesses require volatile/atomic reads, writes, and
310       * CASes.  Because there is no other way to arrange this without
311       * adding further indirections, we use intrinsics
312 <     * (sun.misc.Unsafe) operations.  The lists of nodes within bins
316 <     * are always accurately traversable under volatile reads, so long
317 <     * as lookups check hash code and non-nullness of value before
318 <     * checking key equality.
312 >     * (sun.misc.Unsafe) operations.
313       *
314       * We use the top (sign) bit of Node hash fields for control
315       * purposes -- it is available anyway because of addressing
316 <     * constraints.  Nodes with negative hash fields are forwarding
317 <     * nodes to either TreeBins or resized tables.  The lower 31 bits
324 <     * of each normal Node's hash field contain a transformation of
325 <     * the key's hash code.
316 >     * constraints.  Nodes with negative hash fields are specially
317 >     * handled or ignored in map methods.
318       *
319       * Insertion (via put or its variants) of the first node in an
320       * empty bin is performed by just CASing it to the bin.  This is
# Line 339 | Line 331 | public class ConcurrentHashMapV8<K, V>
331       * validate that it is still the first node after locking it, and
332       * retry if not. Because new nodes are always appended to lists,
333       * once a node is first in a bin, it remains first until deleted
334 <     * or the bin becomes invalidated (upon resizing).  However,
343 <     * operations that only conditionally update may inspect nodes
344 <     * until the point of update. This is a converse of sorts to the
345 <     * lazy locking technique described by Herlihy & Shavit.
334 >     * or the bin becomes invalidated (upon resizing).
335       *
336       * The main disadvantage of per-bin locks is that other update
337       * operations on other nodes in a bin list protected by the same
# Line 375 | Line 364 | public class ConcurrentHashMapV8<K, V>
364       * sometimes deviate significantly from uniform randomness.  This
365       * includes the case when N > (1<<30), so some keys MUST collide.
366       * Similarly for dumb or hostile usages in which multiple keys are
367 <     * designed to have identical hash codes. Also, although we guard
368 <     * against the worst effects of this (see method spread), sets of
369 <     * hashes may differ only in bits that do not impact their bin
370 <     * index for a given power-of-two mask.  So we use a secondary
371 <     * strategy that applies when the number of nodes in a bin exceeds
372 <     * a threshold, and at least one of the keys implements
384 <     * Comparable.  These TreeBins use a balanced tree to hold nodes
385 <     * (a specialized form of red-black trees), bounding search time
386 <     * to O(log N).  Each search step in a TreeBin is around twice as
367 >     * designed to have identical hash codes or ones that differs only
368 >     * in masked-out high bits. So we use a secondary strategy that
369 >     * applies when the number of nodes in a bin exceeds a
370 >     * threshold. These TreeBins use a balanced tree to hold nodes (a
371 >     * specialized form of red-black trees), bounding search time to
372 >     * O(log N).  Each search step in a TreeBin is at least twice as
373       * slow as in a regular list, but given that N cannot exceed
374       * (1<<64) (before running out of addresses) this bounds search
375       * steps, lock hold times, etc, to reasonable constants (roughly
# Line 396 | Line 382 | public class ConcurrentHashMapV8<K, V>
382       * The table is resized when occupancy exceeds a percentage
383       * threshold (nominally, 0.75, but see below).  Any thread
384       * noticing an overfull bin may assist in resizing after the
385 <     * initiating thread allocates and sets up the replacement
386 <     * array. However, rather than stalling, these other threads may
387 <     * proceed with insertions etc.  The use of TreeBins shields us
388 <     * from the worst case effects of overfilling while resizes are in
385 >     * initiating thread allocates and sets up the replacement array.
386 >     * However, rather than stalling, these other threads may proceed
387 >     * with insertions etc.  The use of TreeBins shields us from the
388 >     * worst case effects of overfilling while resizes are in
389       * progress.  Resizing proceeds by transferring bins, one by one,
390 <     * from the table to the next table. To enable concurrency, the
391 <     * next table must be (incrementally) prefilled with place-holders
392 <     * serving as reverse forwarders to the old table.  Because we are
390 >     * from the table to the next table. However, threads claim small
391 >     * blocks of indices to transfer (via field transferIndex) before
392 >     * doing so, reducing contention.  A generation stamp in field
393 >     * sizeCtl ensures that resizings do not overlap. Because we are
394       * using power-of-two expansion, the elements from each bin must
395       * either stay at same index, or move with a power of two
396       * offset. We eliminate unnecessary node creation by catching
# Line 424 | Line 411 | public class ConcurrentHashMapV8<K, V>
411       * locks, average aggregate waits become shorter as resizing
412       * progresses.  The transfer operation must also ensure that all
413       * accessible bins in both the old and new table are usable by any
414 <     * traversal.  This is arranged by proceeding from the last bin
415 <     * (table.length - 1) up towards the first.  Upon seeing a
416 <     * forwarding node, traversals (see class Traverser) arrange to
417 <     * move to the new table without revisiting nodes.  However, to
418 <     * ensure that no intervening nodes are skipped, bin splitting can
419 <     * only begin after the associated reverse-forwarders are in
420 <     * place.
414 >     * traversal.  This is arranged in part by proceeding from the
415 >     * last bin (table.length - 1) up towards the first.  Upon seeing
416 >     * a forwarding node, traversals (see class Traverser) arrange to
417 >     * move to the new table without revisiting nodes.  To ensure that
418 >     * no intervening nodes are skipped even when moved out of order,
419 >     * a stack (see class TableStack) is created on first encounter of
420 >     * a forwarding node during a traversal, to maintain its place if
421 >     * later processing the current table. The need for these
422 >     * save/restore mechanics is relatively rare, but when one
423 >     * forwarding node is encountered, typically many more will be.
424 >     * So Traversers use a simple caching scheme to avoid creating so
425 >     * many new TableStack nodes. (Thanks to Peter Levart for
426 >     * suggesting use of a stack here.)
427       *
428       * The traversal scheme also applies to partial traversals of
429       * ranges of bins (via an alternate Traverser constructor)
# Line 456 | Line 449 | public class ConcurrentHashMapV8<K, V>
449       * bin already holding two or more nodes. Under uniform hash
450       * distributions, the probability of this occurring at threshold
451       * is around 13%, meaning that only about 1 in 8 puts check
452 <     * threshold (and after resizing, many fewer do so). The bulk
453 <     * putAll operation further reduces contention by only committing
454 <     * count updates upon these size checks.
452 >     * threshold (and after resizing, many fewer do so).
453 >     *
454 >     * TreeBins use a special form of comparison for search and
455 >     * related operations (which is the main reason we cannot use
456 >     * existing collections such as TreeMaps). TreeBins contain
457 >     * Comparable elements, but may contain others, as well as
458 >     * elements that are Comparable but not necessarily Comparable for
459 >     * the same T, so we cannot invoke compareTo among them. To handle
460 >     * this, the tree is ordered primarily by hash value, then by
461 >     * Comparable.compareTo order if applicable.  On lookup at a node,
462 >     * if elements are not comparable or compare as 0 then both left
463 >     * and right children may need to be searched in the case of tied
464 >     * hash values. (This corresponds to the full list search that
465 >     * would be necessary if all elements were non-Comparable and had
466 >     * tied hashes.) On insertion, to keep a total ordering (or as
467 >     * close as is required here) across rebalancings, we compare
468 >     * classes and identityHashCodes as tie-breakers. The red-black
469 >     * balancing code is updated from pre-jdk-collections
470 >     * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
471 >     * based in turn on Cormen, Leiserson, and Rivest "Introduction to
472 >     * Algorithms" (CLR).
473 >     *
474 >     * TreeBins also require an additional locking mechanism.  While
475 >     * list traversal is always possible by readers even during
476 >     * updates, tree traversal is not, mainly because of tree-rotations
477 >     * that may change the root node and/or its linkages.  TreeBins
478 >     * include a simple read-write lock mechanism parasitic on the
479 >     * main bin-synchronization strategy: Structural adjustments
480 >     * associated with an insertion or removal are already bin-locked
481 >     * (and so cannot conflict with other writers) but must wait for
482 >     * ongoing readers to finish. Since there can be only one such
483 >     * waiter, we use a simple scheme using a single "waiter" field to
484 >     * block writers.  However, readers need never block.  If the root
485 >     * lock is held, they proceed along the slow traversal path (via
486 >     * next-pointers) until the lock becomes available or the list is
487 >     * exhausted, whichever comes first. These cases are not fast, but
488 >     * maximize aggregate expected throughput.
489       *
490       * Maintaining API and serialization compatibility with previous
491       * versions of this class introduces several oddities. Mainly: We
# Line 468 | Line 495 | public class ConcurrentHashMapV8<K, V>
495       * time that we can guarantee to honor it.) We also declare an
496       * unused "Segment" class that is instantiated in minimal form
497       * only when serializing.
498 +     *
499 +     * Also, solely for compatibility with previous versions of this
500 +     * class, it extends AbstractMap, even though all of its methods
501 +     * are overridden, so it is just useless baggage.
502 +     *
503 +     * This file is organized to make things a little easier to follow
504 +     * while reading than they might otherwise: First the main static
505 +     * declarations and utilities, then fields, then main public
506 +     * methods (with a few factorings of multiple public methods into
507 +     * internal ones), then sizing methods, trees, traversers, and
508 +     * bulk operations.
509       */
510  
511      /* ---------------- Constants -------------- */
# Line 510 | Line 548 | public class ConcurrentHashMapV8<K, V>
548  
549      /**
550       * The bin count threshold for using a tree rather than list for a
551 <     * bin.  The value reflects the approximate break-even point for
552 <     * using tree-based operations.
553 <     */
554 <    private static final int TREE_THRESHOLD = 8;
555 <
518 <    /**
519 <     * Minimum number of rebinnings per transfer step. Ranges are
520 <     * subdivided to allow multiple resizer threads.  This value
521 <     * serves as a lower bound to avoid resizers encountering
522 <     * excessive memory contention.  The value should be at least
523 <     * DEFAULT_CAPACITY.
524 <     */
525 <    private static final int MIN_TRANSFER_STRIDE = 16;
526 <
527 <    /*
528 <     * Encodings for Node hash fields. See above for explanation.
529 <     */
530 <    static final int MOVED     = 0x80000000; // hash field for forwarding nodes
531 <    static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
532 <
533 <    /** Number of CPUS, to place bounds on some sizings */
534 <    static final int NCPU = Runtime.getRuntime().availableProcessors();
535 <
536 <    /* ---------------- Counters -------------- */
537 <
538 <    // Adapted from LongAdder and Striped64.
539 <    // See their internal docs for explanation.
540 <
541 <    // A padded cell for distributing counts
542 <    static final class CounterCell {
543 <        volatile long p0, p1, p2, p3, p4, p5, p6;
544 <        volatile long value;
545 <        volatile long q0, q1, q2, q3, q4, q5, q6;
546 <        CounterCell(long x) { value = x; }
547 <    }
548 <
549 <    /**
550 <     * Holder for the thread-local hash code determining which
551 <     * CounterCell to use. The code is initialized via the
552 <     * counterHashCodeGenerator, but may be moved upon collisions.
553 <     */
554 <    static final class CounterHashCode {
555 <        int code;
556 <    }
557 <
558 <    /**
559 <     * Generates initial value for per-thread CounterHashCodes
560 <     */
561 <    static final AtomicInteger counterHashCodeGenerator = new AtomicInteger();
562 <
563 <    /**
564 <     * Increment for counterHashCodeGenerator. See class ThreadLocal
565 <     * for explanation.
566 <     */
567 <    static final int SEED_INCREMENT = 0x61c88647;
568 <
569 <    /**
570 <     * Per-thread counter hash codes. Shared across all instances.
571 <     */
572 <    static final ThreadLocal<CounterHashCode> threadCounterHashCode =
573 <        new ThreadLocal<CounterHashCode>();
574 <
575 <    /* ---------------- Fields -------------- */
576 <
577 <    /**
578 <     * The array of bins. Lazily initialized upon first insertion.
579 <     * Size is always a power of two. Accessed directly by iterators.
551 >     * bin.  Bins are converted to trees when adding an element to a
552 >     * bin with at least this many nodes. The value must be greater
553 >     * than 2, and should be at least 8 to mesh with assumptions in
554 >     * tree removal about conversion back to plain bins upon
555 >     * shrinkage.
556       */
557 <    transient volatile Node<V>[] table;
557 >    static final int TREEIFY_THRESHOLD = 8;
558  
559      /**
560 <     * The next table to use; non-null only while resizing.
560 >     * The bin count threshold for untreeifying a (split) bin during a
561 >     * resize operation. Should be less than TREEIFY_THRESHOLD, and at
562 >     * most 6 to mesh with shrinkage detection under removal.
563       */
564 <    private transient volatile Node<V>[] nextTable;
564 >    static final int UNTREEIFY_THRESHOLD = 6;
565  
566      /**
567 <     * Base counter value, used mainly when there is no contention,
568 <     * but also as a fallback during table initialization
569 <     * races. Updated via CAS.
567 >     * The smallest table capacity for which bins may be treeified.
568 >     * (Otherwise the table is resized if too many nodes in a bin.)
569 >     * The value should be at least 4 * TREEIFY_THRESHOLD to avoid
570 >     * conflicts between resizing and treeification thresholds.
571       */
572 <    private transient volatile long baseCount;
572 >    static final int MIN_TREEIFY_CAPACITY = 64;
573  
574      /**
575 <     * Table initialization and resizing control.  When negative, the
576 <     * table is being initialized or resized: -1 for initialization,
577 <     * else -(1 + the number of active resizing threads).  Otherwise,
578 <     * when table is null, holds the initial table size to use upon
579 <     * creation, or 0 for default. After initialization, holds the
601 <     * next element count value upon which to resize the table.
602 <     */
603 <    private transient volatile int sizeCtl;
604 <
605 <    /**
606 <     * The next table index (plus one) to split while resizing.
575 >     * Minimum number of rebinnings per transfer step. Ranges are
576 >     * subdivided to allow multiple resizer threads.  This value
577 >     * serves as a lower bound to avoid resizers encountering
578 >     * excessive memory contention.  The value should be at least
579 >     * DEFAULT_CAPACITY.
580       */
581 <    private transient volatile int transferIndex;
581 >    private static final int MIN_TRANSFER_STRIDE = 16;
582  
583      /**
584 <     * The least available table index to split while resizing.
584 >     * The number of bits used for generation stamp in sizeCtl.
585 >     * Must be at least 6 for 32bit arrays.
586       */
587 <    private transient volatile int transferOrigin;
587 >    private static int RESIZE_STAMP_BITS = 16;
588  
589      /**
590 <     * Spinlock (locked via CAS) used when resizing and/or creating Cells.
590 >     * The maximum number of threads that can help resize.
591 >     * Must fit in 32 - RESIZE_STAMP_BITS bits.
592       */
593 <    private transient volatile int counterBusy;
593 >    private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
594  
595      /**
596 <     * Table of counter cells. When non-null, size is a power of 2.
596 >     * The bit shift for recording size stamp in sizeCtl.
597       */
598 <    private transient volatile CounterCell[] counterCells;
624 <
625 <    // views
626 <    private transient KeySetView<K,V> keySet;
627 <    private transient ValuesView<K,V> values;
628 <    private transient EntrySetView<K,V> entrySet;
629 <
630 <    /** For serialization compatibility. Null unless serialized; see below */
631 <    private Segment<K,V>[] segments;
632 <
633 <    /* ---------------- Table element access -------------- */
598 >    private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
599  
600      /*
601 <     * Volatile access methods are used for table elements as well as
602 <     * elements of in-progress next table while resizing.  Uses are
603 <     * null checked by callers, and implicitly bounds-checked, relying
604 <     * on the invariants that tab arrays have non-zero size, and all
605 <     * indices are masked with (tab.length - 1) which is never
606 <     * negative and always less than length. Note that, to be correct
642 <     * wrt arbitrary concurrency errors by users, bounds checks must
643 <     * operate on local variables, which accounts for some odd-looking
644 <     * inline assignments below.
645 <     */
646 <
647 <    @SuppressWarnings("unchecked") static final <V> Node<V> tabAt
648 <        (Node<V>[] tab, int i) { // used by Traverser
649 <        return (Node<V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
650 <    }
601 >     * Encodings for Node hash fields. See above for explanation.
602 >     */
603 >    static final int MOVED     = -1; // hash for forwarding nodes
604 >    static final int TREEBIN   = -2; // hash for roots of trees
605 >    static final int RESERVED  = -3; // hash for transient reservations
606 >    static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
607  
608 <    private static final <V> boolean casTabAt
609 <        (Node<V>[] tab, int i, Node<V> c, Node<V> v) {
654 <        return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
655 <    }
608 >    /** Number of CPUS, to place bounds on some sizings */
609 >    static final int NCPU = Runtime.getRuntime().availableProcessors();
610  
611 <    private static final <V> void setTabAt
612 <        (Node<V>[] tab, int i, Node<V> v) {
613 <        U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
614 <    }
611 >    /** For serialization compatibility. */
612 >    private static final ObjectStreamField[] serialPersistentFields = {
613 >        new ObjectStreamField("segments", Segment[].class),
614 >        new ObjectStreamField("segmentMask", Integer.TYPE),
615 >        new ObjectStreamField("segmentShift", Integer.TYPE)
616 >    };
617  
618      /* ---------------- Nodes -------------- */
619  
620      /**
621 <     * Key-value entry. Note that this is never exported out as a
622 <     * user-visible Map.Entry (see MapEntry below). Nodes with a hash
623 <     * field of MOVED are special, and do not contain user keys or
624 <     * values.  Otherwise, keys are never null, and null val fields
625 <     * indicate that a node is in the process of being deleted or
626 <     * created. For purposes of read-only access, a key may be read
671 <     * before a val, but can only be used after checking val to be
672 <     * non-null.
621 >     * Key-value entry.  This class is never exported out as a
622 >     * user-mutable Map.Entry (i.e., one supporting setValue; see
623 >     * MapEntry below), but can be used for read-only traversals used
624 >     * in bulk tasks.  Subclasses of Node with a negative hash field
625 >     * are special, and contain null keys and values (but are never
626 >     * exported).  Otherwise, keys and vals are never null.
627       */
628 <    static class Node<V> {
628 >    static class Node<K,V> implements Map.Entry<K,V> {
629          final int hash;
630 <        final Object key;
630 >        final K key;
631          volatile V val;
632 <        volatile Node<V> next;
632 >        volatile Node<K,V> next;
633  
634 <        Node(int hash, Object key, V val, Node<V> next) {
634 >        Node(int hash, K key, V val, Node<K,V> next) {
635              this.hash = hash;
636              this.key = key;
637              this.val = val;
638              this.next = next;
639          }
686    }
687
688    /* ---------------- TreeBins -------------- */
689
690    /**
691     * Nodes for use in TreeBins
692     */
693    static final class TreeNode<V> extends Node<V> {
694        TreeNode<V> parent;  // red-black tree links
695        TreeNode<V> left;
696        TreeNode<V> right;
697        TreeNode<V> prev;    // needed to unlink next upon deletion
698        boolean red;
699
700        TreeNode(int hash, Object key, V val, Node<V> next, TreeNode<V> parent) {
701            super(hash, key, val, next);
702            this.parent = parent;
703        }
704    }
705
706    /**
707     * A specialized form of red-black tree for use in bins
708     * whose size exceeds a threshold.
709     *
710     * TreeBins use a special form of comparison for search and
711     * related operations (which is the main reason we cannot use
712     * existing collections such as TreeMaps). TreeBins contain
713     * Comparable elements, but may contain others, as well as
714     * elements that are Comparable but not necessarily Comparable<T>
715     * for the same T, so we cannot invoke compareTo among them. To
716     * handle this, the tree is ordered primarily by hash value, then
717     * by getClass().getName() order, and then by Comparator order
718     * among elements of the same class.  On lookup at a node, if
719     * elements are not comparable or compare as 0, both left and
720     * right children may need to be searched in the case of tied hash
721     * values. (This corresponds to the full list search that would be
722     * necessary if all elements were non-Comparable and had tied
723     * hashes.)  The red-black balancing code is updated from
724     * pre-jdk-collections
725     * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
726     * based in turn on Cormen, Leiserson, and Rivest "Introduction to
727     * Algorithms" (CLR).
728     *
729     * TreeBins also maintain a separate locking discipline than
730     * regular bins. Because they are forwarded via special MOVED
731     * nodes at bin heads (which can never change once established),
732     * we cannot use those nodes as locks. Instead, TreeBin
733     * extends AbstractQueuedSynchronizer to support a simple form of
734     * read-write lock. For update operations and table validation,
735     * the exclusive form of lock behaves in the same way as bin-head
736     * locks. However, lookups use shared read-lock mechanics to allow
737     * multiple readers in the absence of writers.  Additionally,
738     * these lookups do not ever block: While the lock is not
739     * available, they proceed along the slow traversal path (via
740     * next-pointers) until the lock becomes available or the list is
741     * exhausted, whichever comes first. (These cases are not fast,
742     * but maximize aggregate expected throughput.)  The AQS mechanics
743     * for doing this are straightforward.  The lock state is held as
744     * AQS getState().  Read counts are negative; the write count (1)
745     * is positive.  There are no signalling preferences among readers
746     * and writers. Since we don't need to export full Lock API, we
747     * just override the minimal AQS methods and use them directly.
748     */
749    static final class TreeBin<V> extends AbstractQueuedSynchronizer {
750        private static final long serialVersionUID = 2249069246763182397L;
751        transient TreeNode<V> root;  // root of tree
752        transient TreeNode<V> first; // head of next-pointer list
753
754        /* AQS overrides */
755        public final boolean isHeldExclusively() { return getState() > 0; }
756        public final boolean tryAcquire(int ignore) {
757            if (compareAndSetState(0, 1)) {
758                setExclusiveOwnerThread(Thread.currentThread());
759                return true;
760            }
761            return false;
762        }
763        public final boolean tryRelease(int ignore) {
764            setExclusiveOwnerThread(null);
765            setState(0);
766            return true;
767        }
768        public final int tryAcquireShared(int ignore) {
769            for (int c;;) {
770                if ((c = getState()) > 0)
771                    return -1;
772                if (compareAndSetState(c, c -1))
773                    return 1;
774            }
775        }
776        public final boolean tryReleaseShared(int ignore) {
777            int c;
778            do {} while (!compareAndSetState(c = getState(), c + 1));
779            return c == -1;
780        }
781
782        /** From CLR */
783        private void rotateLeft(TreeNode<V> p) {
784            if (p != null) {
785                TreeNode<V> r = p.right, pp, rl;
786                if ((rl = p.right = r.left) != null)
787                    rl.parent = p;
788                if ((pp = r.parent = p.parent) == null)
789                    root = r;
790                else if (pp.left == p)
791                    pp.left = r;
792                else
793                    pp.right = r;
794                r.left = p;
795                p.parent = r;
796            }
797        }
798
799        /** From CLR */
800        private void rotateRight(TreeNode<V> p) {
801            if (p != null) {
802                TreeNode<V> l = p.left, pp, lr;
803                if ((lr = p.left = l.right) != null)
804                    lr.parent = p;
805                if ((pp = l.parent = p.parent) == null)
806                    root = l;
807                else if (pp.right == p)
808                    pp.right = l;
809                else
810                    pp.left = l;
811                l.right = p;
812                p.parent = l;
813            }
814        }
640  
641 <        /**
642 <         * Returns the TreeNode (or null if not found) for the given key
643 <         * starting at given root.
644 <         */
645 <        @SuppressWarnings("unchecked") final TreeNode<V> getTreeNode
646 <            (int h, Object k, TreeNode<V> p) {
822 <            Class<?> c = k.getClass();
823 <            while (p != null) {
824 <                int dir, ph;  Object pk; Class<?> pc;
825 <                if ((ph = p.hash) == h) {
826 <                    if ((pk = p.key) == k || k.equals(pk))
827 <                        return p;
828 <                    if (c != (pc = pk.getClass()) ||
829 <                        !(k instanceof Comparable) ||
830 <                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
831 <                        if ((dir = (c == pc) ? 0 :
832 <                             c.getName().compareTo(pc.getName())) == 0) {
833 <                            TreeNode<V> r = null, pl, pr; // check both sides
834 <                            if ((pr = p.right) != null && h >= pr.hash &&
835 <                                (r = getTreeNode(h, k, pr)) != null)
836 <                                return r;
837 <                            else if ((pl = p.left) != null && h <= pl.hash)
838 <                                dir = -1;
839 <                            else // nothing there
840 <                                return null;
841 <                        }
842 <                    }
843 <                }
844 <                else
845 <                    dir = (h < ph) ? -1 : 1;
846 <                p = (dir > 0) ? p.right : p.left;
847 <            }
848 <            return null;
641 >        public final K getKey()       { return key; }
642 >        public final V getValue()     { return val; }
643 >        public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
644 >        public final String toString(){ return key + "=" + val; }
645 >        public final V setValue(V value) {
646 >            throw new UnsupportedOperationException();
647          }
648  
649 <        /**
650 <         * Wrapper for getTreeNode used by CHM.get. Tries to obtain
651 <         * read-lock to call getTreeNode, but during failure to get
652 <         * lock, searches along next links.
653 <         */
654 <        final V getValue(int h, Object k) {
655 <            Node<V> r = null;
858 <            int c = getState(); // Must read lock state first
859 <            for (Node<V> e = first; e != null; e = e.next) {
860 <                if (c <= 0 && compareAndSetState(c, c - 1)) {
861 <                    try {
862 <                        r = getTreeNode(h, k, root);
863 <                    } finally {
864 <                        releaseShared(0);
865 <                    }
866 <                    break;
867 <                }
868 <                else if (e.hash == h && k.equals(e.key)) {
869 <                    r = e;
870 <                    break;
871 <                }
872 <                else
873 <                    c = getState();
874 <            }
875 <            return r == null ? null : r.val;
649 >        public final boolean equals(Object o) {
650 >            Object k, v, u; Map.Entry<?,?> e;
651 >            return ((o instanceof Map.Entry) &&
652 >                    (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
653 >                    (v = e.getValue()) != null &&
654 >                    (k == key || k.equals(key)) &&
655 >                    (v == (u = val) || v.equals(u)));
656          }
657  
658          /**
659 <         * Finds or adds a node.
880 <         * @return null if added
659 >         * Virtualized support for map.get(); overridden in subclasses.
660           */
661 <        @SuppressWarnings("unchecked") final TreeNode<V> putTreeNode
662 <            (int h, Object k, V v) {
663 <            Class<?> c = k.getClass();
664 <            TreeNode<V> pp = root, p = null;
665 <            int dir = 0;
666 <            while (pp != null) { // find existing node or leaf to insert at
667 <                int ph;  Object pk; Class<?> pc;
668 <                p = pp;
669 <                if ((ph = p.hash) == h) {
891 <                    if ((pk = p.key) == k || k.equals(pk))
892 <                        return p;
893 <                    if (c != (pc = pk.getClass()) ||
894 <                        !(k instanceof Comparable) ||
895 <                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
896 <                        TreeNode<V> s = null, r = null, pr;
897 <                        if ((dir = (c == pc) ? 0 :
898 <                             c.getName().compareTo(pc.getName())) == 0) {
899 <                            if ((pr = p.right) != null && h >= pr.hash &&
900 <                                (r = getTreeNode(h, k, pr)) != null)
901 <                                return r;
902 <                            else // continue left
903 <                                dir = -1;
904 <                        }
905 <                        else if ((pr = p.right) != null && h >= pr.hash)
906 <                            s = pr;
907 <                        if (s != null && (r = getTreeNode(h, k, s)) != null)
908 <                            return r;
909 <                    }
910 <                }
911 <                else
912 <                    dir = (h < ph) ? -1 : 1;
913 <                pp = (dir > 0) ? p.right : p.left;
914 <            }
915 <
916 <            TreeNode<V> f = first;
917 <            TreeNode<V> x = first = new TreeNode<V>(h, k, v, f, p);
918 <            if (p == null)
919 <                root = x;
920 <            else { // attach and rebalance; adapted from CLR
921 <                TreeNode<V> xp, xpp;
922 <                if (f != null)
923 <                    f.prev = x;
924 <                if (dir <= 0)
925 <                    p.left = x;
926 <                else
927 <                    p.right = x;
928 <                x.red = true;
929 <                while (x != null && (xp = x.parent) != null && xp.red &&
930 <                       (xpp = xp.parent) != null) {
931 <                    TreeNode<V> xppl = xpp.left;
932 <                    if (xp == xppl) {
933 <                        TreeNode<V> y = xpp.right;
934 <                        if (y != null && y.red) {
935 <                            y.red = false;
936 <                            xp.red = false;
937 <                            xpp.red = true;
938 <                            x = xpp;
939 <                        }
940 <                        else {
941 <                            if (x == xp.right) {
942 <                                rotateLeft(x = xp);
943 <                                xpp = (xp = x.parent) == null ? null : xp.parent;
944 <                            }
945 <                            if (xp != null) {
946 <                                xp.red = false;
947 <                                if (xpp != null) {
948 <                                    xpp.red = true;
949 <                                    rotateRight(xpp);
950 <                                }
951 <                            }
952 <                        }
953 <                    }
954 <                    else {
955 <                        TreeNode<V> y = xppl;
956 <                        if (y != null && y.red) {
957 <                            y.red = false;
958 <                            xp.red = false;
959 <                            xpp.red = true;
960 <                            x = xpp;
961 <                        }
962 <                        else {
963 <                            if (x == xp.left) {
964 <                                rotateRight(x = xp);
965 <                                xpp = (xp = x.parent) == null ? null : xp.parent;
966 <                            }
967 <                            if (xp != null) {
968 <                                xp.red = false;
969 <                                if (xpp != null) {
970 <                                    xpp.red = true;
971 <                                    rotateLeft(xpp);
972 <                                }
973 <                            }
974 <                        }
975 <                    }
976 <                }
977 <                TreeNode<V> r = root;
978 <                if (r != null && r.red)
979 <                    r.red = false;
661 >        Node<K,V> find(int h, Object k) {
662 >            Node<K,V> e = this;
663 >            if (k != null) {
664 >                do {
665 >                    K ek;
666 >                    if (e.hash == h &&
667 >                        ((ek = e.key) == k || (ek != null && k.equals(ek))))
668 >                        return e;
669 >                } while ((e = e.next) != null);
670              }
671              return null;
672          }
983
984        /**
985         * Removes the given node, that must be present before this
986         * call.  This is messier than typical red-black deletion code
987         * because we cannot swap the contents of an interior node
988         * with a leaf successor that is pinned by "next" pointers
989         * that are accessible independently of lock. So instead we
990         * swap the tree linkages.
991         */
992        final void deleteTreeNode(TreeNode<V> p) {
993            TreeNode<V> next = (TreeNode<V>)p.next; // unlink traversal pointers
994            TreeNode<V> pred = p.prev;
995            if (pred == null)
996                first = next;
997            else
998                pred.next = next;
999            if (next != null)
1000                next.prev = pred;
1001            TreeNode<V> replacement;
1002            TreeNode<V> pl = p.left;
1003            TreeNode<V> pr = p.right;
1004            if (pl != null && pr != null) {
1005                TreeNode<V> s = pr, sl;
1006                while ((sl = s.left) != null) // find successor
1007                    s = sl;
1008                boolean c = s.red; s.red = p.red; p.red = c; // swap colors
1009                TreeNode<V> sr = s.right;
1010                TreeNode<V> pp = p.parent;
1011                if (s == pr) { // p was s's direct parent
1012                    p.parent = s;
1013                    s.right = p;
1014                }
1015                else {
1016                    TreeNode<V> sp = s.parent;
1017                    if ((p.parent = sp) != null) {
1018                        if (s == sp.left)
1019                            sp.left = p;
1020                        else
1021                            sp.right = p;
1022                    }
1023                    if ((s.right = pr) != null)
1024                        pr.parent = s;
1025                }
1026                p.left = null;
1027                if ((p.right = sr) != null)
1028                    sr.parent = p;
1029                if ((s.left = pl) != null)
1030                    pl.parent = s;
1031                if ((s.parent = pp) == null)
1032                    root = s;
1033                else if (p == pp.left)
1034                    pp.left = s;
1035                else
1036                    pp.right = s;
1037                replacement = sr;
1038            }
1039            else
1040                replacement = (pl != null) ? pl : pr;
1041            TreeNode<V> pp = p.parent;
1042            if (replacement == null) {
1043                if (pp == null) {
1044                    root = null;
1045                    return;
1046                }
1047                replacement = p;
1048            }
1049            else {
1050                replacement.parent = pp;
1051                if (pp == null)
1052                    root = replacement;
1053                else if (p == pp.left)
1054                    pp.left = replacement;
1055                else
1056                    pp.right = replacement;
1057                p.left = p.right = p.parent = null;
1058            }
1059            if (!p.red) { // rebalance, from CLR
1060                TreeNode<V> x = replacement;
1061                while (x != null) {
1062                    TreeNode<V> xp, xpl;
1063                    if (x.red || (xp = x.parent) == null) {
1064                        x.red = false;
1065                        break;
1066                    }
1067                    if (x == (xpl = xp.left)) {
1068                        TreeNode<V> sib = xp.right;
1069                        if (sib != null && sib.red) {
1070                            sib.red = false;
1071                            xp.red = true;
1072                            rotateLeft(xp);
1073                            sib = (xp = x.parent) == null ? null : xp.right;
1074                        }
1075                        if (sib == null)
1076                            x = xp;
1077                        else {
1078                            TreeNode<V> sl = sib.left, sr = sib.right;
1079                            if ((sr == null || !sr.red) &&
1080                                (sl == null || !sl.red)) {
1081                                sib.red = true;
1082                                x = xp;
1083                            }
1084                            else {
1085                                if (sr == null || !sr.red) {
1086                                    if (sl != null)
1087                                        sl.red = false;
1088                                    sib.red = true;
1089                                    rotateRight(sib);
1090                                    sib = (xp = x.parent) == null ?
1091                                        null : xp.right;
1092                                }
1093                                if (sib != null) {
1094                                    sib.red = (xp == null) ? false : xp.red;
1095                                    if ((sr = sib.right) != null)
1096                                        sr.red = false;
1097                                }
1098                                if (xp != null) {
1099                                    xp.red = false;
1100                                    rotateLeft(xp);
1101                                }
1102                                x = root;
1103                            }
1104                        }
1105                    }
1106                    else { // symmetric
1107                        TreeNode<V> sib = xpl;
1108                        if (sib != null && sib.red) {
1109                            sib.red = false;
1110                            xp.red = true;
1111                            rotateRight(xp);
1112                            sib = (xp = x.parent) == null ? null : xp.left;
1113                        }
1114                        if (sib == null)
1115                            x = xp;
1116                        else {
1117                            TreeNode<V> sl = sib.left, sr = sib.right;
1118                            if ((sl == null || !sl.red) &&
1119                                (sr == null || !sr.red)) {
1120                                sib.red = true;
1121                                x = xp;
1122                            }
1123                            else {
1124                                if (sl == null || !sl.red) {
1125                                    if (sr != null)
1126                                        sr.red = false;
1127                                    sib.red = true;
1128                                    rotateLeft(sib);
1129                                    sib = (xp = x.parent) == null ?
1130                                        null : xp.left;
1131                                }
1132                                if (sib != null) {
1133                                    sib.red = (xp == null) ? false : xp.red;
1134                                    if ((sl = sib.left) != null)
1135                                        sl.red = false;
1136                                }
1137                                if (xp != null) {
1138                                    xp.red = false;
1139                                    rotateRight(xp);
1140                                }
1141                                x = root;
1142                            }
1143                        }
1144                    }
1145                }
1146            }
1147            if (p == replacement && (pp = p.parent) != null) {
1148                if (p == pp.left) // detach pointers
1149                    pp.left = null;
1150                else if (p == pp.right)
1151                    pp.right = null;
1152                p.parent = null;
1153            }
1154        }
673      }
674  
675 <    /* ---------------- Collision reduction methods -------------- */
675 >    /* ---------------- Static utilities -------------- */
676  
677      /**
678 <     * Spreads higher bits to lower, and also forces top bit to 0.
679 <     * Because the table uses power-of-two masking, sets of hashes
680 <     * that vary only in bits above the current mask will always
681 <     * collide. (Among known examples are sets of Float keys holding
682 <     * consecutive whole numbers in small tables.)  To counter this,
683 <     * we apply a transform that spreads the impact of higher bits
678 >     * Spreads (XORs) higher bits of hash to lower and also forces top
679 >     * bit to 0. Because the table uses power-of-two masking, sets of
680 >     * hashes that vary only in bits above the current mask will
681 >     * always collide. (Among known examples are sets of Float keys
682 >     * holding consecutive whole numbers in small tables.)  So we
683 >     * apply a transform that spreads the impact of higher bits
684       * downward. There is a tradeoff between speed, utility, and
685       * quality of bit-spreading. Because many common sets of hashes
686 <     * are already reasonably distributed across bits (so don't benefit
687 <     * from spreading), and because we use trees to handle large sets
688 <     * of collisions in bins, we don't need excessively high quality.
686 >     * are already reasonably distributed (so don't benefit from
687 >     * spreading), and because we use trees to handle large sets of
688 >     * collisions in bins, we just XOR some shifted bits in the
689 >     * cheapest possible way to reduce systematic lossage, as well as
690 >     * to incorporate impact of the highest bits that would otherwise
691 >     * never be used in index calculations because of table bounds.
692       */
693 <    private static final int spread(int h) {
694 <        h ^= (h >>> 18) ^ (h >>> 12);
1174 <        return (h ^ (h >>> 10)) & HASH_BITS;
693 >    static final int spread(int h) {
694 >        return (h ^ (h >>> 16)) & HASH_BITS;
695      }
696  
697      /**
698 <     * Replaces a list bin with a tree bin if key is comparable.  Call
699 <     * only when locked.
698 >     * Returns a power of two table size for the given desired capacity.
699 >     * See Hackers Delight, sec 3.2
700       */
701 <    private final void replaceWithTreeBin(Node<V>[] tab, int index, Object key) {
702 <        if (key instanceof Comparable) {
703 <            TreeBin<V> t = new TreeBin<V>();
704 <            for (Node<V> e = tabAt(tab, index); e != null; e = e.next)
705 <                t.putTreeNode(e.hash, e.key, e.val);
706 <            setTabAt(tab, index, new Node<V>(MOVED, t, null, null));
707 <        }
701 >    private static final int tableSizeFor(int c) {
702 >        int n = c - 1;
703 >        n |= n >>> 1;
704 >        n |= n >>> 2;
705 >        n |= n >>> 4;
706 >        n |= n >>> 8;
707 >        n |= n >>> 16;
708 >        return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
709      }
710  
711 <    /* ---------------- Internal access and update methods -------------- */
712 <
713 <    /** Implementation for get and containsKey */
714 <    @SuppressWarnings("unchecked") private final V internalGet(Object k) {
715 <        int h = spread(k.hashCode());
716 <        retry: for (Node<V>[] tab = table; tab != null;) {
717 <            Node<V> e; Object ek; V ev; int eh; // locals to read fields once
718 <            for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
719 <                if ((eh = e.hash) < 0) {
720 <                    if ((ek = e.key) instanceof TreeBin)  // search TreeBin
721 <                        return ((TreeBin<V>)ek).getValue(h, k);
722 <                    else {                      // restart with new table
723 <                        tab = (Node<V>[])ek;
724 <                        continue retry;
725 <                    }
711 >    /**
712 >     * Returns x's Class if it is of the form "class C implements
713 >     * Comparable<C>", else null.
714 >     */
715 >    static Class<?> comparableClassFor(Object x) {
716 >        if (x instanceof Comparable) {
717 >            Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
718 >            if ((c = x.getClass()) == String.class) // bypass checks
719 >                return c;
720 >            if ((ts = c.getGenericInterfaces()) != null) {
721 >                for (int i = 0; i < ts.length; ++i) {
722 >                    if (((t = ts[i]) instanceof ParameterizedType) &&
723 >                        ((p = (ParameterizedType)t).getRawType() ==
724 >                         Comparable.class) &&
725 >                        (as = p.getActualTypeArguments()) != null &&
726 >                        as.length == 1 && as[0] == c) // type arg is c
727 >                        return c;
728                  }
1206                else if (eh == h && (ev = e.val) != null &&
1207                         ((ek = e.key) == k || k.equals(ek)))
1208                    return ev;
729              }
1210            break;
730          }
731          return null;
732      }
733  
734      /**
735 <     * Implementation for the four public remove/replace methods:
736 <     * Replaces node value with v, conditional upon match of cv if
1218 <     * non-null.  If resulting value is null, delete.
735 >     * Returns k.compareTo(x) if x matches kc (k's screened comparable
736 >     * class), else 0.
737       */
738 <    @SuppressWarnings("unchecked") private final V internalReplace
739 <        (Object k, V v, Object cv) {
740 <        int h = spread(k.hashCode());
741 <        V oldVal = null;
1224 <        for (Node<V>[] tab = table;;) {
1225 <            Node<V> f; int i, fh; Object fk;
1226 <            if (tab == null ||
1227 <                (f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1228 <                break;
1229 <            else if ((fh = f.hash) < 0) {
1230 <                if ((fk = f.key) instanceof TreeBin) {
1231 <                    TreeBin<V> t = (TreeBin<V>)fk;
1232 <                    boolean validated = false;
1233 <                    boolean deleted = false;
1234 <                    t.acquire(0);
1235 <                    try {
1236 <                        if (tabAt(tab, i) == f) {
1237 <                            validated = true;
1238 <                            TreeNode<V> p = t.getTreeNode(h, k, t.root);
1239 <                            if (p != null) {
1240 <                                V pv = p.val;
1241 <                                if (cv == null || cv == pv || cv.equals(pv)) {
1242 <                                    oldVal = pv;
1243 <                                    if ((p.val = v) == null) {
1244 <                                        deleted = true;
1245 <                                        t.deleteTreeNode(p);
1246 <                                    }
1247 <                                }
1248 <                            }
1249 <                        }
1250 <                    } finally {
1251 <                        t.release(0);
1252 <                    }
1253 <                    if (validated) {
1254 <                        if (deleted)
1255 <                            addCount(-1L, -1);
1256 <                        break;
1257 <                    }
1258 <                }
1259 <                else
1260 <                    tab = (Node<V>[])fk;
1261 <            }
1262 <            else if (fh != h && f.next == null) // precheck
1263 <                break;                          // rules out possible existence
1264 <            else {
1265 <                boolean validated = false;
1266 <                boolean deleted = false;
1267 <                synchronized (f) {
1268 <                    if (tabAt(tab, i) == f) {
1269 <                        validated = true;
1270 <                        for (Node<V> e = f, pred = null;;) {
1271 <                            Object ek; V ev;
1272 <                            if (e.hash == h &&
1273 <                                ((ev = e.val) != null) &&
1274 <                                ((ek = e.key) == k || k.equals(ek))) {
1275 <                                if (cv == null || cv == ev || cv.equals(ev)) {
1276 <                                    oldVal = ev;
1277 <                                    if ((e.val = v) == null) {
1278 <                                        deleted = true;
1279 <                                        Node<V> en = e.next;
1280 <                                        if (pred != null)
1281 <                                            pred.next = en;
1282 <                                        else
1283 <                                            setTabAt(tab, i, en);
1284 <                                    }
1285 <                                }
1286 <                                break;
1287 <                            }
1288 <                            pred = e;
1289 <                            if ((e = e.next) == null)
1290 <                                break;
1291 <                        }
1292 <                    }
1293 <                }
1294 <                if (validated) {
1295 <                    if (deleted)
1296 <                        addCount(-1L, -1);
1297 <                    break;
1298 <                }
1299 <            }
1300 <        }
1301 <        return oldVal;
738 >    @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
739 >    static int compareComparables(Class<?> kc, Object k, Object x) {
740 >        return (x == null || x.getClass() != kc ? 0 :
741 >                ((Comparable)k).compareTo(x));
742      }
743  
744 <    /*
1305 <     * Internal versions of insertion methods
1306 <     * All have the same basic structure as the first (internalPut):
1307 <     *  1. If table uninitialized, create
1308 <     *  2. If bin empty, try to CAS new node
1309 <     *  3. If bin stale, use new table
1310 <     *  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1311 <     *  5. Lock and validate; if valid, scan and add or update
1312 <     *
1313 <     * The putAll method differs mainly in attempting to pre-allocate
1314 <     * enough table space, and also more lazily performs count updates
1315 <     * and checks.
1316 <     *
1317 <     * Most of the function-accepting methods can't be factored nicely
1318 <     * because they require different functional forms, so instead
1319 <     * sprawl out similar mechanics.
1320 <     */
1321 <
1322 <    /** Implementation for put and putIfAbsent */
1323 <    @SuppressWarnings("unchecked") private final V internalPut
1324 <        (K k, V v, boolean onlyIfAbsent) {
1325 <        if (k == null || v == null) throw new NullPointerException();
1326 <        int h = spread(k.hashCode());
1327 <        int len = 0;
1328 <        for (Node<V>[] tab = table;;) {
1329 <            int i, fh; Node<V> f; Object fk; V fv;
1330 <            if (tab == null)
1331 <                tab = initTable();
1332 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1333 <                if (casTabAt(tab, i, null, new Node<V>(h, k, v, null)))
1334 <                    break;                   // no lock when adding to empty bin
1335 <            }
1336 <            else if ((fh = f.hash) < 0) {
1337 <                if ((fk = f.key) instanceof TreeBin) {
1338 <                    TreeBin<V> t = (TreeBin<V>)fk;
1339 <                    V oldVal = null;
1340 <                    t.acquire(0);
1341 <                    try {
1342 <                        if (tabAt(tab, i) == f) {
1343 <                            len = 2;
1344 <                            TreeNode<V> p = t.putTreeNode(h, k, v);
1345 <                            if (p != null) {
1346 <                                oldVal = p.val;
1347 <                                if (!onlyIfAbsent)
1348 <                                    p.val = v;
1349 <                            }
1350 <                        }
1351 <                    } finally {
1352 <                        t.release(0);
1353 <                    }
1354 <                    if (len != 0) {
1355 <                        if (oldVal != null)
1356 <                            return oldVal;
1357 <                        break;
1358 <                    }
1359 <                }
1360 <                else
1361 <                    tab = (Node<V>[])fk;
1362 <            }
1363 <            else if (onlyIfAbsent && fh == h && (fv = f.val) != null &&
1364 <                     ((fk = f.key) == k || k.equals(fk))) // peek while nearby
1365 <                return fv;
1366 <            else {
1367 <                V oldVal = null;
1368 <                synchronized (f) {
1369 <                    if (tabAt(tab, i) == f) {
1370 <                        len = 1;
1371 <                        for (Node<V> e = f;; ++len) {
1372 <                            Object ek; V ev;
1373 <                            if (e.hash == h &&
1374 <                                (ev = e.val) != null &&
1375 <                                ((ek = e.key) == k || k.equals(ek))) {
1376 <                                oldVal = ev;
1377 <                                if (!onlyIfAbsent)
1378 <                                    e.val = v;
1379 <                                break;
1380 <                            }
1381 <                            Node<V> last = e;
1382 <                            if ((e = e.next) == null) {
1383 <                                last.next = new Node<V>(h, k, v, null);
1384 <                                if (len >= TREE_THRESHOLD)
1385 <                                    replaceWithTreeBin(tab, i, k);
1386 <                                break;
1387 <                            }
1388 <                        }
1389 <                    }
1390 <                }
1391 <                if (len != 0) {
1392 <                    if (oldVal != null)
1393 <                        return oldVal;
1394 <                    break;
1395 <                }
1396 <            }
1397 <        }
1398 <        addCount(1L, len);
1399 <        return null;
1400 <    }
744 >    /* ---------------- Table element access -------------- */
745  
746 <    /** Implementation for computeIfAbsent */
747 <    @SuppressWarnings("unchecked") private final V internalComputeIfAbsent
748 <        (K k, Fun<? super K, ? extends V> mf) {
749 <        if (k == null || mf == null)
750 <            throw new NullPointerException();
751 <        int h = spread(k.hashCode());
752 <        V val = null;
753 <        int len = 0;
754 <        for (Node<V>[] tab = table;;) {
755 <            Node<V> f; int i; Object fk;
756 <            if (tab == null)
757 <                tab = initTable();
758 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
759 <                Node<V> node = new Node<V>(h, k, null, null);
760 <                synchronized (node) {
761 <                    if (casTabAt(tab, i, null, node)) {
762 <                        len = 1;
763 <                        try {
764 <                            if ((val = mf.apply(k)) != null)
1421 <                                node.val = val;
1422 <                        } finally {
1423 <                            if (val == null)
1424 <                                setTabAt(tab, i, null);
1425 <                        }
1426 <                    }
1427 <                }
1428 <                if (len != 0)
1429 <                    break;
1430 <            }
1431 <            else if (f.hash < 0) {
1432 <                if ((fk = f.key) instanceof TreeBin) {
1433 <                    TreeBin<V> t = (TreeBin<V>)fk;
1434 <                    boolean added = false;
1435 <                    t.acquire(0);
1436 <                    try {
1437 <                        if (tabAt(tab, i) == f) {
1438 <                            len = 1;
1439 <                            TreeNode<V> p = t.getTreeNode(h, k, t.root);
1440 <                            if (p != null)
1441 <                                val = p.val;
1442 <                            else if ((val = mf.apply(k)) != null) {
1443 <                                added = true;
1444 <                                len = 2;
1445 <                                t.putTreeNode(h, k, val);
1446 <                            }
1447 <                        }
1448 <                    } finally {
1449 <                        t.release(0);
1450 <                    }
1451 <                    if (len != 0) {
1452 <                        if (!added)
1453 <                            return val;
1454 <                        break;
1455 <                    }
1456 <                }
1457 <                else
1458 <                    tab = (Node<V>[])fk;
1459 <            }
1460 <            else {
1461 <                for (Node<V> e = f; e != null; e = e.next) { // prescan
1462 <                    Object ek; V ev;
1463 <                    if (e.hash == h && (ev = e.val) != null &&
1464 <                        ((ek = e.key) == k || k.equals(ek)))
1465 <                        return ev;
1466 <                }
1467 <                boolean added = false;
1468 <                synchronized (f) {
1469 <                    if (tabAt(tab, i) == f) {
1470 <                        len = 1;
1471 <                        for (Node<V> e = f;; ++len) {
1472 <                            Object ek; V ev;
1473 <                            if (e.hash == h &&
1474 <                                (ev = e.val) != null &&
1475 <                                ((ek = e.key) == k || k.equals(ek))) {
1476 <                                val = ev;
1477 <                                break;
1478 <                            }
1479 <                            Node<V> last = e;
1480 <                            if ((e = e.next) == null) {
1481 <                                if ((val = mf.apply(k)) != null) {
1482 <                                    added = true;
1483 <                                    last.next = new Node<V>(h, k, val, null);
1484 <                                    if (len >= TREE_THRESHOLD)
1485 <                                        replaceWithTreeBin(tab, i, k);
1486 <                                }
1487 <                                break;
1488 <                            }
1489 <                        }
1490 <                    }
1491 <                }
1492 <                if (len != 0) {
1493 <                    if (!added)
1494 <                        return val;
1495 <                    break;
1496 <                }
1497 <            }
1498 <        }
1499 <        if (val != null)
1500 <            addCount(1L, len);
1501 <        return val;
746 >    /*
747 >     * Volatile access methods are used for table elements as well as
748 >     * elements of in-progress next table while resizing.  All uses of
749 >     * the tab arguments must be null checked by callers.  All callers
750 >     * also paranoically precheck that tab's length is not zero (or an
751 >     * equivalent check), thus ensuring that any index argument taking
752 >     * the form of a hash value anded with (length - 1) is a valid
753 >     * index.  Note that, to be correct wrt arbitrary concurrency
754 >     * errors by users, these checks must operate on local variables,
755 >     * which accounts for some odd-looking inline assignments below.
756 >     * Note that calls to setTabAt always occur within locked regions,
757 >     * and so in principle require only release ordering, not
758 >     * full volatile semantics, but are currently coded as volatile
759 >     * writes to be conservative.
760 >     */
761 >
762 >    @SuppressWarnings("unchecked")
763 >    static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
764 >        return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
765      }
766  
767 <    /** Implementation for compute */
768 <    @SuppressWarnings("unchecked") private final V internalCompute
769 <        (K k, boolean onlyIfPresent,
1507 <         BiFun<? super K, ? super V, ? extends V> mf) {
1508 <        if (k == null || mf == null)
1509 <            throw new NullPointerException();
1510 <        int h = spread(k.hashCode());
1511 <        V val = null;
1512 <        int delta = 0;
1513 <        int len = 0;
1514 <        for (Node<V>[] tab = table;;) {
1515 <            Node<V> f; int i, fh; Object fk;
1516 <            if (tab == null)
1517 <                tab = initTable();
1518 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1519 <                if (onlyIfPresent)
1520 <                    break;
1521 <                Node<V> node = new Node<V>(h, k, null, null);
1522 <                synchronized (node) {
1523 <                    if (casTabAt(tab, i, null, node)) {
1524 <                        try {
1525 <                            len = 1;
1526 <                            if ((val = mf.apply(k, null)) != null) {
1527 <                                node.val = val;
1528 <                                delta = 1;
1529 <                            }
1530 <                        } finally {
1531 <                            if (delta == 0)
1532 <                                setTabAt(tab, i, null);
1533 <                        }
1534 <                    }
1535 <                }
1536 <                if (len != 0)
1537 <                    break;
1538 <            }
1539 <            else if ((fh = f.hash) < 0) {
1540 <                if ((fk = f.key) instanceof TreeBin) {
1541 <                    TreeBin<V> t = (TreeBin<V>)fk;
1542 <                    t.acquire(0);
1543 <                    try {
1544 <                        if (tabAt(tab, i) == f) {
1545 <                            len = 1;
1546 <                            TreeNode<V> p = t.getTreeNode(h, k, t.root);
1547 <                            if (p == null && onlyIfPresent)
1548 <                                break;
1549 <                            V pv = (p == null) ? null : p.val;
1550 <                            if ((val = mf.apply(k, pv)) != null) {
1551 <                                if (p != null)
1552 <                                    p.val = val;
1553 <                                else {
1554 <                                    len = 2;
1555 <                                    delta = 1;
1556 <                                    t.putTreeNode(h, k, val);
1557 <                                }
1558 <                            }
1559 <                            else if (p != null) {
1560 <                                delta = -1;
1561 <                                t.deleteTreeNode(p);
1562 <                            }
1563 <                        }
1564 <                    } finally {
1565 <                        t.release(0);
1566 <                    }
1567 <                    if (len != 0)
1568 <                        break;
1569 <                }
1570 <                else
1571 <                    tab = (Node<V>[])fk;
1572 <            }
1573 <            else {
1574 <                synchronized (f) {
1575 <                    if (tabAt(tab, i) == f) {
1576 <                        len = 1;
1577 <                        for (Node<V> e = f, pred = null;; ++len) {
1578 <                            Object ek; V ev;
1579 <                            if (e.hash == h &&
1580 <                                (ev = e.val) != null &&
1581 <                                ((ek = e.key) == k || k.equals(ek))) {
1582 <                                val = mf.apply(k, ev);
1583 <                                if (val != null)
1584 <                                    e.val = val;
1585 <                                else {
1586 <                                    delta = -1;
1587 <                                    Node<V> en = e.next;
1588 <                                    if (pred != null)
1589 <                                        pred.next = en;
1590 <                                    else
1591 <                                        setTabAt(tab, i, en);
1592 <                                }
1593 <                                break;
1594 <                            }
1595 <                            pred = e;
1596 <                            if ((e = e.next) == null) {
1597 <                                if (!onlyIfPresent &&
1598 <                                    (val = mf.apply(k, null)) != null) {
1599 <                                    pred.next = new Node<V>(h, k, val, null);
1600 <                                    delta = 1;
1601 <                                    if (len >= TREE_THRESHOLD)
1602 <                                        replaceWithTreeBin(tab, i, k);
1603 <                                }
1604 <                                break;
1605 <                            }
1606 <                        }
1607 <                    }
1608 <                }
1609 <                if (len != 0)
1610 <                    break;
1611 <            }
1612 <        }
1613 <        if (delta != 0)
1614 <            addCount((long)delta, len);
1615 <        return val;
767 >    static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
768 >                                        Node<K,V> c, Node<K,V> v) {
769 >        return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
770      }
771  
772 <    /** Implementation for merge */
773 <    @SuppressWarnings("unchecked") private final V internalMerge
1620 <        (K k, V v, BiFun<? super V, ? super V, ? extends V> mf) {
1621 <        if (k == null || v == null || mf == null)
1622 <            throw new NullPointerException();
1623 <        int h = spread(k.hashCode());
1624 <        V val = null;
1625 <        int delta = 0;
1626 <        int len = 0;
1627 <        for (Node<V>[] tab = table;;) {
1628 <            int i; Node<V> f; Object fk; V fv;
1629 <            if (tab == null)
1630 <                tab = initTable();
1631 <            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1632 <                if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1633 <                    delta = 1;
1634 <                    val = v;
1635 <                    break;
1636 <                }
1637 <            }
1638 <            else if (f.hash < 0) {
1639 <                if ((fk = f.key) instanceof TreeBin) {
1640 <                    TreeBin<V> t = (TreeBin<V>)fk;
1641 <                    t.acquire(0);
1642 <                    try {
1643 <                        if (tabAt(tab, i) == f) {
1644 <                            len = 1;
1645 <                            TreeNode<V> p = t.getTreeNode(h, k, t.root);
1646 <                            val = (p == null) ? v : mf.apply(p.val, v);
1647 <                            if (val != null) {
1648 <                                if (p != null)
1649 <                                    p.val = val;
1650 <                                else {
1651 <                                    len = 2;
1652 <                                    delta = 1;
1653 <                                    t.putTreeNode(h, k, val);
1654 <                                }
1655 <                            }
1656 <                            else if (p != null) {
1657 <                                delta = -1;
1658 <                                t.deleteTreeNode(p);
1659 <                            }
1660 <                        }
1661 <                    } finally {
1662 <                        t.release(0);
1663 <                    }
1664 <                    if (len != 0)
1665 <                        break;
1666 <                }
1667 <                else
1668 <                    tab = (Node<V>[])fk;
1669 <            }
1670 <            else {
1671 <                synchronized (f) {
1672 <                    if (tabAt(tab, i) == f) {
1673 <                        len = 1;
1674 <                        for (Node<V> e = f, pred = null;; ++len) {
1675 <                            Object ek; V ev;
1676 <                            if (e.hash == h &&
1677 <                                (ev = e.val) != null &&
1678 <                                ((ek = e.key) == k || k.equals(ek))) {
1679 <                                val = mf.apply(ev, v);
1680 <                                if (val != null)
1681 <                                    e.val = val;
1682 <                                else {
1683 <                                    delta = -1;
1684 <                                    Node<V> en = e.next;
1685 <                                    if (pred != null)
1686 <                                        pred.next = en;
1687 <                                    else
1688 <                                        setTabAt(tab, i, en);
1689 <                                }
1690 <                                break;
1691 <                            }
1692 <                            pred = e;
1693 <                            if ((e = e.next) == null) {
1694 <                                val = v;
1695 <                                pred.next = new Node<V>(h, k, val, null);
1696 <                                delta = 1;
1697 <                                if (len >= TREE_THRESHOLD)
1698 <                                    replaceWithTreeBin(tab, i, k);
1699 <                                break;
1700 <                            }
1701 <                        }
1702 <                    }
1703 <                }
1704 <                if (len != 0)
1705 <                    break;
1706 <            }
1707 <        }
1708 <        if (delta != 0)
1709 <            addCount((long)delta, len);
1710 <        return val;
772 >    static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
773 >        U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
774      }
775  
776 <    /** Implementation for putAll */
1714 <    @SuppressWarnings("unchecked") private final void internalPutAll
1715 <        (Map<? extends K, ? extends V> m) {
1716 <        tryPresize(m.size());
1717 <        long delta = 0L;     // number of uncommitted additions
1718 <        boolean npe = false; // to throw exception on exit for nulls
1719 <        try {                // to clean up counts on other exceptions
1720 <            for (Map.Entry<?, ? extends V> entry : m.entrySet()) {
1721 <                Object k; V v;
1722 <                if (entry == null || (k = entry.getKey()) == null ||
1723 <                    (v = entry.getValue()) == null) {
1724 <                    npe = true;
1725 <                    break;
1726 <                }
1727 <                int h = spread(k.hashCode());
1728 <                for (Node<V>[] tab = table;;) {
1729 <                    int i; Node<V> f; int fh; Object fk;
1730 <                    if (tab == null)
1731 <                        tab = initTable();
1732 <                    else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1733 <                        if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1734 <                            ++delta;
1735 <                            break;
1736 <                        }
1737 <                    }
1738 <                    else if ((fh = f.hash) < 0) {
1739 <                        if ((fk = f.key) instanceof TreeBin) {
1740 <                            TreeBin<V> t = (TreeBin<V>)fk;
1741 <                            boolean validated = false;
1742 <                            t.acquire(0);
1743 <                            try {
1744 <                                if (tabAt(tab, i) == f) {
1745 <                                    validated = true;
1746 <                                    TreeNode<V> p = t.getTreeNode(h, k, t.root);
1747 <                                    if (p != null)
1748 <                                        p.val = v;
1749 <                                    else {
1750 <                                        t.putTreeNode(h, k, v);
1751 <                                        ++delta;
1752 <                                    }
1753 <                                }
1754 <                            } finally {
1755 <                                t.release(0);
1756 <                            }
1757 <                            if (validated)
1758 <                                break;
1759 <                        }
1760 <                        else
1761 <                            tab = (Node<V>[])fk;
1762 <                    }
1763 <                    else {
1764 <                        int len = 0;
1765 <                        synchronized (f) {
1766 <                            if (tabAt(tab, i) == f) {
1767 <                                len = 1;
1768 <                                for (Node<V> e = f;; ++len) {
1769 <                                    Object ek; V ev;
1770 <                                    if (e.hash == h &&
1771 <                                        (ev = e.val) != null &&
1772 <                                        ((ek = e.key) == k || k.equals(ek))) {
1773 <                                        e.val = v;
1774 <                                        break;
1775 <                                    }
1776 <                                    Node<V> last = e;
1777 <                                    if ((e = e.next) == null) {
1778 <                                        ++delta;
1779 <                                        last.next = new Node<V>(h, k, v, null);
1780 <                                        if (len >= TREE_THRESHOLD)
1781 <                                            replaceWithTreeBin(tab, i, k);
1782 <                                        break;
1783 <                                    }
1784 <                                }
1785 <                            }
1786 <                        }
1787 <                        if (len != 0) {
1788 <                            if (len > 1) {
1789 <                                addCount(delta, len);
1790 <                                delta = 0L;
1791 <                            }
1792 <                            break;
1793 <                        }
1794 <                    }
1795 <                }
1796 <            }
1797 <        } finally {
1798 <            if (delta != 0L)
1799 <                addCount(delta, 2);
1800 <        }
1801 <        if (npe)
1802 <            throw new NullPointerException();
1803 <    }
776 >    /* ---------------- Fields -------------- */
777  
778      /**
779 <     * Implementation for clear. Steps through each bin, removing all
780 <     * nodes.
779 >     * The array of bins. Lazily initialized upon first insertion.
780 >     * Size is always a power of two. Accessed directly by iterators.
781       */
782 <    @SuppressWarnings("unchecked") private final void internalClear() {
1810 <        long delta = 0L; // negative number of deletions
1811 <        int i = 0;
1812 <        Node<V>[] tab = table;
1813 <        while (tab != null && i < tab.length) {
1814 <            Node<V> f = tabAt(tab, i);
1815 <            if (f == null)
1816 <                ++i;
1817 <            else if (f.hash < 0) {
1818 <                Object fk;
1819 <                if ((fk = f.key) instanceof TreeBin) {
1820 <                    TreeBin<V> t = (TreeBin<V>)fk;
1821 <                    t.acquire(0);
1822 <                    try {
1823 <                        if (tabAt(tab, i) == f) {
1824 <                            for (Node<V> p = t.first; p != null; p = p.next) {
1825 <                                if (p.val != null) { // (currently always true)
1826 <                                    p.val = null;
1827 <                                    --delta;
1828 <                                }
1829 <                            }
1830 <                            t.first = null;
1831 <                            t.root = null;
1832 <                            ++i;
1833 <                        }
1834 <                    } finally {
1835 <                        t.release(0);
1836 <                    }
1837 <                }
1838 <                else
1839 <                    tab = (Node<V>[])fk;
1840 <            }
1841 <            else {
1842 <                synchronized (f) {
1843 <                    if (tabAt(tab, i) == f) {
1844 <                        for (Node<V> e = f; e != null; e = e.next) {
1845 <                            if (e.val != null) {  // (currently always true)
1846 <                                e.val = null;
1847 <                                --delta;
1848 <                            }
1849 <                        }
1850 <                        setTabAt(tab, i, null);
1851 <                        ++i;
1852 <                    }
1853 <                }
1854 <            }
1855 <        }
1856 <        if (delta != 0L)
1857 <            addCount(delta, -1);
1858 <    }
1859 <
1860 <    /* ---------------- Table Initialization and Resizing -------------- */
782 >    transient volatile Node<K,V>[] table;
783  
784      /**
785 <     * Returns a power of two table size for the given desired capacity.
1864 <     * See Hackers Delight, sec 3.2
785 >     * The next table to use; non-null only while resizing.
786       */
787 <    private static final int tableSizeFor(int c) {
1867 <        int n = c - 1;
1868 <        n |= n >>> 1;
1869 <        n |= n >>> 2;
1870 <        n |= n >>> 4;
1871 <        n |= n >>> 8;
1872 <        n |= n >>> 16;
1873 <        return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1874 <    }
787 >    private transient volatile Node<K,V>[] nextTable;
788  
789      /**
790 <     * Initializes table, using the size recorded in sizeCtl.
790 >     * Base counter value, used mainly when there is no contention,
791 >     * but also as a fallback during table initialization
792 >     * races. Updated via CAS.
793       */
794 <    @SuppressWarnings("unchecked") private final Node<V>[] initTable() {
1880 <        Node<V>[] tab; int sc;
1881 <        while ((tab = table) == null) {
1882 <            if ((sc = sizeCtl) < 0)
1883 <                Thread.yield(); // lost initialization race; just spin
1884 <            else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1885 <                try {
1886 <                    if ((tab = table) == null) {
1887 <                        int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1888 <                        @SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1889 <                        table = tab = (Node<V>[])tb;
1890 <                        sc = n - (n >>> 2);
1891 <                    }
1892 <                } finally {
1893 <                    sizeCtl = sc;
1894 <                }
1895 <                break;
1896 <            }
1897 <        }
1898 <        return tab;
1899 <    }
794 >    private transient volatile long baseCount;
795  
796      /**
797 <     * Adds to count, and if table is too small and not already
798 <     * resizing, initiates transfer. If already resizing, helps
799 <     * perform transfer if work is available.  Rechecks occupancy
800 <     * after a transfer to see if another resize is already needed
801 <     * because resizings are lagging additions.
802 <     *
1908 <     * @param x the count to add
1909 <     * @param check if <0, don't check resize, if <= 1 only check if uncontended
797 >     * Table initialization and resizing control.  When negative, the
798 >     * table is being initialized or resized: -1 for initialization,
799 >     * else -(1 + the number of active resizing threads).  Otherwise,
800 >     * when table is null, holds the initial table size to use upon
801 >     * creation, or 0 for default. After initialization, holds the
802 >     * next element count value upon which to resize the table.
803       */
804 <    private final void addCount(long x, int check) {
1912 <        CounterCell[] as; long b, s;
1913 <        if ((as = counterCells) != null ||
1914 <            !U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1915 <            CounterHashCode hc; CounterCell a; long v; int m;
1916 <            boolean uncontended = true;
1917 <            if ((hc = threadCounterHashCode.get()) == null ||
1918 <                as == null || (m = as.length - 1) < 0 ||
1919 <                (a = as[m & hc.code]) == null ||
1920 <                !(uncontended =
1921 <                  U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1922 <                fullAddCount(x, hc, uncontended);
1923 <                return;
1924 <            }
1925 <            if (check <= 1)
1926 <                return;
1927 <            s = sumCount();
1928 <        }
1929 <        if (check >= 0) {
1930 <            Node<V>[] tab, nt; int sc;
1931 <            while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1932 <                   tab.length < MAXIMUM_CAPACITY) {
1933 <                if (sc < 0) {
1934 <                    if (sc == -1 || transferIndex <= transferOrigin ||
1935 <                        (nt = nextTable) == null)
1936 <                        break;
1937 <                    if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1938 <                        transfer(tab, nt);
1939 <                }
1940 <                else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1941 <                    transfer(tab, null);
1942 <                s = sumCount();
1943 <            }
1944 <        }
1945 <    }
804 >    private transient volatile int sizeCtl;
805  
806      /**
807 <     * Tries to presize table to accommodate the given number of elements.
1949 <     *
1950 <     * @param size number of elements (doesn't need to be perfectly accurate)
807 >     * The next table index (plus one) to split while resizing.
808       */
809 <    @SuppressWarnings("unchecked") private final void tryPresize(int size) {
1953 <        int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1954 <            tableSizeFor(size + (size >>> 1) + 1);
1955 <        int sc;
1956 <        while ((sc = sizeCtl) >= 0) {
1957 <            Node<V>[] tab = table; int n;
1958 <            if (tab == null || (n = tab.length) == 0) {
1959 <                n = (sc > c) ? sc : c;
1960 <                if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1961 <                    try {
1962 <                        if (table == tab) {
1963 <                            @SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1964 <                            table = (Node<V>[])tb;
1965 <                            sc = n - (n >>> 2);
1966 <                        }
1967 <                    } finally {
1968 <                        sizeCtl = sc;
1969 <                    }
1970 <                }
1971 <            }
1972 <            else if (c <= sc || n >= MAXIMUM_CAPACITY)
1973 <                break;
1974 <            else if (tab == table &&
1975 <                     U.compareAndSwapInt(this, SIZECTL, sc, -2))
1976 <                transfer(tab, null);
1977 <        }
1978 <    }
809 >    private transient volatile int transferIndex;
810  
811      /**
812 <     * Moves and/or copies the nodes in each bin to new table. See
1982 <     * above for explanation.
812 >     * Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
813       */
814 <    @SuppressWarnings("unchecked") private final void transfer
1985 <        (Node<V>[] tab, Node<V>[] nextTab) {
1986 <        int n = tab.length, stride;
1987 <        if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1988 <            stride = MIN_TRANSFER_STRIDE; // subdivide range
1989 <        if (nextTab == null) {            // initiating
1990 <            try {
1991 <                @SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1];
1992 <                nextTab = (Node<V>[])tb;
1993 <            } catch (Throwable ex) {      // try to cope with OOME
1994 <                sizeCtl = Integer.MAX_VALUE;
1995 <                return;
1996 <            }
1997 <            nextTable = nextTab;
1998 <            transferOrigin = n;
1999 <            transferIndex = n;
2000 <            Node<V> rev = new Node<V>(MOVED, tab, null, null);
2001 <            for (int k = n; k > 0;) {    // progressively reveal ready slots
2002 <                int nextk = (k > stride) ? k - stride : 0;
2003 <                for (int m = nextk; m < k; ++m)
2004 <                    nextTab[m] = rev;
2005 <                for (int m = n + nextk; m < n + k; ++m)
2006 <                    nextTab[m] = rev;
2007 <                U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2008 <            }
2009 <        }
2010 <        int nextn = nextTab.length;
2011 <        Node<V> fwd = new Node<V>(MOVED, nextTab, null, null);
2012 <        boolean advance = true;
2013 <        for (int i = 0, bound = 0;;) {
2014 <            int nextIndex, nextBound; Node<V> f; Object fk;
2015 <            while (advance) {
2016 <                if (--i >= bound)
2017 <                    advance = false;
2018 <                else if ((nextIndex = transferIndex) <= transferOrigin) {
2019 <                    i = -1;
2020 <                    advance = false;
2021 <                }
2022 <                else if (U.compareAndSwapInt
2023 <                         (this, TRANSFERINDEX, nextIndex,
2024 <                          nextBound = (nextIndex > stride ?
2025 <                                       nextIndex - stride : 0))) {
2026 <                    bound = nextBound;
2027 <                    i = nextIndex - 1;
2028 <                    advance = false;
2029 <                }
2030 <            }
2031 <            if (i < 0 || i >= n || i + n >= nextn) {
2032 <                for (int sc;;) {
2033 <                    if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2034 <                        if (sc == -1) {
2035 <                            nextTable = null;
2036 <                            table = nextTab;
2037 <                            sizeCtl = (n << 1) - (n >>> 1);
2038 <                        }
2039 <                        return;
2040 <                    }
2041 <                }
2042 <            }
2043 <            else if ((f = tabAt(tab, i)) == null) {
2044 <                if (casTabAt(tab, i, null, fwd)) {
2045 <                    setTabAt(nextTab, i, null);
2046 <                    setTabAt(nextTab, i + n, null);
2047 <                    advance = true;
2048 <                }
2049 <            }
2050 <            else if (f.hash >= 0) {
2051 <                synchronized (f) {
2052 <                    if (tabAt(tab, i) == f) {
2053 <                        int runBit = f.hash & n;
2054 <                        Node<V> lastRun = f, lo = null, hi = null;
2055 <                        for (Node<V> p = f.next; p != null; p = p.next) {
2056 <                            int b = p.hash & n;
2057 <                            if (b != runBit) {
2058 <                                runBit = b;
2059 <                                lastRun = p;
2060 <                            }
2061 <                        }
2062 <                        if (runBit == 0)
2063 <                            lo = lastRun;
2064 <                        else
2065 <                            hi = lastRun;
2066 <                        for (Node<V> p = f; p != lastRun; p = p.next) {
2067 <                            int ph = p.hash;
2068 <                            Object pk = p.key; V pv = p.val;
2069 <                            if ((ph & n) == 0)
2070 <                                lo = new Node<V>(ph, pk, pv, lo);
2071 <                            else
2072 <                                hi = new Node<V>(ph, pk, pv, hi);
2073 <                        }
2074 <                        setTabAt(nextTab, i, lo);
2075 <                        setTabAt(nextTab, i + n, hi);
2076 <                        setTabAt(tab, i, fwd);
2077 <                        advance = true;
2078 <                    }
2079 <                }
2080 <            }
2081 <            else if ((fk = f.key) instanceof TreeBin) {
2082 <                TreeBin<V> t = (TreeBin<V>)fk;
2083 <                t.acquire(0);
2084 <                try {
2085 <                    if (tabAt(tab, i) == f) {
2086 <                        TreeBin<V> lt = new TreeBin<V>();
2087 <                        TreeBin<V> ht = new TreeBin<V>();
2088 <                        int lc = 0, hc = 0;
2089 <                        for (Node<V> e = t.first; e != null; e = e.next) {
2090 <                            int h = e.hash;
2091 <                            Object k = e.key; V v = e.val;
2092 <                            if ((h & n) == 0) {
2093 <                                ++lc;
2094 <                                lt.putTreeNode(h, k, v);
2095 <                            }
2096 <                            else {
2097 <                                ++hc;
2098 <                                ht.putTreeNode(h, k, v);
2099 <                            }
2100 <                        }
2101 <                        Node<V> ln, hn; // throw away trees if too small
2102 <                        if (lc < TREE_THRESHOLD) {
2103 <                            ln = null;
2104 <                            for (Node<V> p = lt.first; p != null; p = p.next)
2105 <                                ln = new Node<V>(p.hash, p.key, p.val, ln);
2106 <                        }
2107 <                        else
2108 <                            ln = new Node<V>(MOVED, lt, null, null);
2109 <                        setTabAt(nextTab, i, ln);
2110 <                        if (hc < TREE_THRESHOLD) {
2111 <                            hn = null;
2112 <                            for (Node<V> p = ht.first; p != null; p = p.next)
2113 <                                hn = new Node<V>(p.hash, p.key, p.val, hn);
2114 <                        }
2115 <                        else
2116 <                            hn = new Node<V>(MOVED, ht, null, null);
2117 <                        setTabAt(nextTab, i + n, hn);
2118 <                        setTabAt(tab, i, fwd);
2119 <                        advance = true;
2120 <                    }
2121 <                } finally {
2122 <                    t.release(0);
2123 <                }
2124 <            }
2125 <            else
2126 <                advance = true; // already processed
2127 <        }
2128 <    }
2129 <
2130 <    /* ---------------- Counter support -------------- */
2131 <
2132 <    final long sumCount() {
2133 <        CounterCell[] as = counterCells; CounterCell a;
2134 <        long sum = baseCount;
2135 <        if (as != null) {
2136 <            for (int i = 0; i < as.length; ++i) {
2137 <                if ((a = as[i]) != null)
2138 <                    sum += a.value;
2139 <            }
2140 <        }
2141 <        return sum;
2142 <    }
2143 <
2144 <    // See LongAdder version for explanation
2145 <    private final void fullAddCount(long x, CounterHashCode hc,
2146 <                                    boolean wasUncontended) {
2147 <        int h;
2148 <        if (hc == null) {
2149 <            hc = new CounterHashCode();
2150 <            int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT);
2151 <            h = hc.code = (s == 0) ? 1 : s; // Avoid zero
2152 <            threadCounterHashCode.set(hc);
2153 <        }
2154 <        else
2155 <            h = hc.code;
2156 <        boolean collide = false;                // True if last slot nonempty
2157 <        for (;;) {
2158 <            CounterCell[] as; CounterCell a; int n; long v;
2159 <            if ((as = counterCells) != null && (n = as.length) > 0) {
2160 <                if ((a = as[(n - 1) & h]) == null) {
2161 <                    if (counterBusy == 0) {            // Try to attach new Cell
2162 <                        CounterCell r = new CounterCell(x); // Optimistic create
2163 <                        if (counterBusy == 0 &&
2164 <                            U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) {
2165 <                            boolean created = false;
2166 <                            try {               // Recheck under lock
2167 <                                CounterCell[] rs; int m, j;
2168 <                                if ((rs = counterCells) != null &&
2169 <                                    (m = rs.length) > 0 &&
2170 <                                    rs[j = (m - 1) & h] == null) {
2171 <                                    rs[j] = r;
2172 <                                    created = true;
2173 <                                }
2174 <                            } finally {
2175 <                                counterBusy = 0;
2176 <                            }
2177 <                            if (created)
2178 <                                break;
2179 <                            continue;           // Slot is now non-empty
2180 <                        }
2181 <                    }
2182 <                    collide = false;
2183 <                }
2184 <                else if (!wasUncontended)       // CAS already known to fail
2185 <                    wasUncontended = true;      // Continue after rehash
2186 <                else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2187 <                    break;
2188 <                else if (counterCells != as || n >= NCPU)
2189 <                    collide = false;            // At max size or stale
2190 <                else if (!collide)
2191 <                    collide = true;
2192 <                else if (counterBusy == 0 &&
2193 <                         U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) {
2194 <                    try {
2195 <                        if (counterCells == as) {// Expand table unless stale
2196 <                            CounterCell[] rs = new CounterCell[n << 1];
2197 <                            for (int i = 0; i < n; ++i)
2198 <                                rs[i] = as[i];
2199 <                            counterCells = rs;
2200 <                        }
2201 <                    } finally {
2202 <                        counterBusy = 0;
2203 <                    }
2204 <                    collide = false;
2205 <                    continue;                   // Retry with expanded table
2206 <                }
2207 <                h ^= h << 13;                   // Rehash
2208 <                h ^= h >>> 17;
2209 <                h ^= h << 5;
2210 <            }
2211 <            else if (counterBusy == 0 && counterCells == as &&
2212 <                     U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) {
2213 <                boolean init = false;
2214 <                try {                           // Initialize table
2215 <                    if (counterCells == as) {
2216 <                        CounterCell[] rs = new CounterCell[2];
2217 <                        rs[h & 1] = new CounterCell(x);
2218 <                        counterCells = rs;
2219 <                        init = true;
2220 <                    }
2221 <                } finally {
2222 <                    counterBusy = 0;
2223 <                }
2224 <                if (init)
2225 <                    break;
2226 <            }
2227 <            else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2228 <                break;                          // Fall back on using base
2229 <        }
2230 <        hc.code = h;                            // Record index for next time
2231 <    }
2232 <
2233 <    /* ----------------Table Traversal -------------- */
814 >    private transient volatile int cellsBusy;
815  
816      /**
817 <     * Encapsulates traversal for methods such as containsValue; also
818 <     * serves as a base class for other iterators and bulk tasks.
819 <     *
2239 <     * At each step, the iterator snapshots the key ("nextKey") and
2240 <     * value ("nextVal") of a valid node (i.e., one that, at point of
2241 <     * snapshot, has a non-null user value). Because val fields can
2242 <     * change (including to null, indicating deletion), field nextVal
2243 <     * might not be accurate at point of use, but still maintains the
2244 <     * weak consistency property of holding a value that was once
2245 <     * valid. To support iterator.remove, the nextKey field is not
2246 <     * updated (nulled out) when the iterator cannot advance.
2247 <     *
2248 <     * Internal traversals directly access these fields, as in:
2249 <     * {@code while (it.advance() != null) { process(it.nextKey); }}
2250 <     *
2251 <     * Exported iterators must track whether the iterator has advanced
2252 <     * (in hasNext vs next) (by setting/checking/nulling field
2253 <     * nextVal), and then extract key, value, or key-value pairs as
2254 <     * return values of next().
2255 <     *
2256 <     * The iterator visits once each still-valid node that was
2257 <     * reachable upon iterator construction. It might miss some that
2258 <     * were added to a bin after the bin was visited, which is OK wrt
2259 <     * consistency guarantees. Maintaining this property in the face
2260 <     * of possible ongoing resizes requires a fair amount of
2261 <     * bookkeeping state that is difficult to optimize away amidst
2262 <     * volatile accesses.  Even so, traversal maintains reasonable
2263 <     * throughput.
2264 <     *
2265 <     * Normally, iteration proceeds bin-by-bin traversing lists.
2266 <     * However, if the table has been resized, then all future steps
2267 <     * must traverse both the bin at the current index as well as at
2268 <     * (index + baseSize); and so on for further resizings. To
2269 <     * paranoically cope with potential sharing by users of iterators
2270 <     * across threads, iteration terminates if a bounds checks fails
2271 <     * for a table read.
2272 <     *
2273 <     * This class extends CountedCompleter to streamline parallel
2274 <     * iteration in bulk operations. This adds only a few fields of
2275 <     * space overhead, which is small enough in cases where it is not
2276 <     * needed to not worry about it.  Because CountedCompleter is
2277 <     * Serializable, but iterators need not be, we need to add warning
2278 <     * suppressions.
2279 <     */
2280 <    @SuppressWarnings("serial") static class Traverser<K,V,R>
2281 <        extends CountedCompleter<R> {
2282 <        final ConcurrentHashMapV8<K, V> map;
2283 <        Node<V> next;        // the next entry to use
2284 <        Object nextKey;      // cached key field of next
2285 <        V nextVal;           // cached val field of next
2286 <        Node<V>[] tab;       // current table; updated if resized
2287 <        int index;           // index of bin to use next
2288 <        int baseIndex;       // current index of initial table
2289 <        int baseLimit;       // index bound for initial table
2290 <        int baseSize;        // initial table size
2291 <        int batch;           // split control
2292 <
2293 <        /** Creates iterator for all entries in the table. */
2294 <        Traverser(ConcurrentHashMapV8<K, V> map) {
2295 <            this.map = map;
2296 <        }
2297 <
2298 <        /** Creates iterator for split() methods and task constructors */
2299 <        Traverser(ConcurrentHashMapV8<K,V> map, Traverser<K,V,?> it, int batch) {
2300 <            super(it);
2301 <            this.batch = batch;
2302 <            if ((this.map = map) != null && it != null) { // split parent
2303 <                Node<V>[] t;
2304 <                if ((t = it.tab) == null &&
2305 <                    (t = it.tab = map.table) != null)
2306 <                    it.baseLimit = it.baseSize = t.length;
2307 <                this.tab = t;
2308 <                this.baseSize = it.baseSize;
2309 <                int hi = this.baseLimit = it.baseLimit;
2310 <                it.baseLimit = this.index = this.baseIndex =
2311 <                    (hi + it.baseIndex + 1) >>> 1;
2312 <            }
2313 <        }
2314 <
2315 <        /**
2316 <         * Advances next; returns nextVal or null if terminated.
2317 <         * See above for explanation.
2318 <         */
2319 <        @SuppressWarnings("unchecked") final V advance() {
2320 <            Node<V> e = next;
2321 <            V ev = null;
2322 <            outer: do {
2323 <                if (e != null)                  // advance past used/skipped node
2324 <                    e = e.next;
2325 <                while (e == null) {             // get to next non-null bin
2326 <                    ConcurrentHashMapV8<K, V> m;
2327 <                    Node<V>[] t; int b, i, n; Object ek; //  must use locals
2328 <                    if ((t = tab) != null)
2329 <                        n = t.length;
2330 <                    else if ((m = map) != null && (t = tab = m.table) != null)
2331 <                        n = baseLimit = baseSize = t.length;
2332 <                    else
2333 <                        break outer;
2334 <                    if ((b = baseIndex) >= baseLimit ||
2335 <                        (i = index) < 0 || i >= n)
2336 <                        break outer;
2337 <                    if ((e = tabAt(t, i)) != null && e.hash < 0) {
2338 <                        if ((ek = e.key) instanceof TreeBin)
2339 <                            e = ((TreeBin<V>)ek).first;
2340 <                        else {
2341 <                            tab = (Node<V>[])ek;
2342 <                            continue;           // restarts due to null val
2343 <                        }
2344 <                    }                           // visit upper slots if present
2345 <                    index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2346 <                }
2347 <                nextKey = e.key;
2348 <            } while ((ev = e.val) == null);    // skip deleted or special nodes
2349 <            next = e;
2350 <            return nextVal = ev;
2351 <        }
2352 <
2353 <        public final void remove() {
2354 <            Object k = nextKey;
2355 <            if (k == null && (advance() == null || (k = nextKey) == null))
2356 <                throw new IllegalStateException();
2357 <            map.internalReplace(k, null, null);
2358 <        }
2359 <
2360 <        public final boolean hasNext() {
2361 <            return nextVal != null || advance() != null;
2362 <        }
2363 <
2364 <        public final boolean hasMoreElements() { return hasNext(); }
2365 <
2366 <        public void compute() { } // default no-op CountedCompleter body
817 >     * Table of counter cells. When non-null, size is a power of 2.
818 >     */
819 >    private transient volatile CounterCell[] counterCells;
820  
821 <        /**
822 <         * Returns a batch value > 0 if this task should (and must) be
823 <         * split, if so, adding to pending count, and in any case
824 <         * updating batch value. The initial batch value is approx
2372 <         * exp2 of the number of times (minus one) to split task by
2373 <         * two before executing leaf action. This value is faster to
2374 <         * compute and more convenient to use as a guide to splitting
2375 <         * than is the depth, since it is used while dividing by two
2376 <         * anyway.
2377 <         */
2378 <        final int preSplit() {
2379 <            ConcurrentHashMapV8<K, V> m; int b; Node<V>[] t;  ForkJoinPool pool;
2380 <            if ((b = batch) < 0 && (m = map) != null) { // force initialization
2381 <                if ((t = tab) == null && (t = tab = m.table) != null)
2382 <                    baseLimit = baseSize = t.length;
2383 <                if (t != null) {
2384 <                    long n = m.sumCount();
2385 <                    int par = ((pool = getPool()) == null) ?
2386 <                        ForkJoinPool.getCommonPoolParallelism() :
2387 <                        pool.getParallelism();
2388 <                    int sp = par << 3; // slack of 8
2389 <                    b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2390 <                }
2391 <            }
2392 <            b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1);
2393 <            if ((batch = b) > 0)
2394 <                addToPendingCount(1);
2395 <            return b;
2396 <        }
821 >    // views
822 >    private transient KeySetView<K,V> keySet;
823 >    private transient ValuesView<K,V> values;
824 >    private transient EntrySetView<K,V> entrySet;
825  
2398    }
826  
827      /* ---------------- Public operations -------------- */
828  
# Line 2431 | Line 858 | public class ConcurrentHashMapV8<K, V>
858       */
859      public ConcurrentHashMapV8(Map<? extends K, ? extends V> m) {
860          this.sizeCtl = DEFAULT_CAPACITY;
861 <        internalPutAll(m);
861 >        putAll(m);
862      }
863  
864      /**
# Line 2472 | Line 899 | public class ConcurrentHashMapV8<K, V>
899       * nonpositive
900       */
901      public ConcurrentHashMapV8(int initialCapacity,
902 <                               float loadFactor, int concurrencyLevel) {
902 >                             float loadFactor, int concurrencyLevel) {
903          if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
904              throw new IllegalArgumentException();
905          if (initialCapacity < concurrencyLevel)   // Use at least as many bins
# Line 2483 | Line 910 | public class ConcurrentHashMapV8<K, V>
910          this.sizeCtl = cap;
911      }
912  
913 <    /**
2487 <     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2488 <     * from the given type to {@code Boolean.TRUE}.
2489 <     *
2490 <     * @return the new set
2491 <     */
2492 <    public static <K> KeySetView<K,Boolean> newKeySet() {
2493 <        return new KeySetView<K,Boolean>(new ConcurrentHashMapV8<K,Boolean>(),
2494 <                                      Boolean.TRUE);
2495 <    }
2496 <
2497 <    /**
2498 <     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2499 <     * from the given type to {@code Boolean.TRUE}.
2500 <     *
2501 <     * @param initialCapacity The implementation performs internal
2502 <     * sizing to accommodate this many elements.
2503 <     * @throws IllegalArgumentException if the initial capacity of
2504 <     * elements is negative
2505 <     * @return the new set
2506 <     */
2507 <    public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2508 <        return new KeySetView<K,Boolean>
2509 <            (new ConcurrentHashMapV8<K,Boolean>(initialCapacity), Boolean.TRUE);
2510 <    }
2511 <
2512 <    /**
2513 <     * {@inheritDoc}
2514 <     */
2515 <    public boolean isEmpty() {
2516 <        return sumCount() <= 0L; // ignore transient negative values
2517 <    }
913 >    // Original (since JDK1.2) Map methods
914  
915      /**
916       * {@inheritDoc}
# Line 2527 | Line 923 | public class ConcurrentHashMapV8<K, V>
923      }
924  
925      /**
926 <     * Returns the number of mappings. This method should be used
2531 <     * instead of {@link #size} because a ConcurrentHashMapV8 may
2532 <     * contain more mappings than can be represented as an int. The
2533 <     * value returned is an estimate; the actual count may differ if
2534 <     * there are concurrent insertions or removals.
2535 <     *
2536 <     * @return the number of mappings
926 >     * {@inheritDoc}
927       */
928 <    public long mappingCount() {
929 <        long n = sumCount();
2540 <        return (n < 0L) ? 0L : n; // ignore transient negative values
928 >    public boolean isEmpty() {
929 >        return sumCount() <= 0L; // ignore transient negative values
930      }
931  
932      /**
# Line 2552 | Line 941 | public class ConcurrentHashMapV8<K, V>
941       * @throws NullPointerException if the specified key is null
942       */
943      public V get(Object key) {
944 <        return internalGet(key);
945 <    }
946 <
947 <    /**
948 <     * Returns the value to which the specified key is mapped,
949 <     * or the given defaultValue if this map contains no mapping for the key.
950 <     *
951 <     * @param key the key
952 <     * @param defaultValue the value to return if this map contains
953 <     * no mapping for the given key
954 <     * @return the mapping for the key, if present; else the defaultValue
955 <     * @throws NullPointerException if the specified key is null
956 <     */
957 <    public V getValueOrDefault(Object key, V defaultValue) {
958 <        V v;
959 <        return (v = internalGet(key)) == null ? defaultValue : v;
944 >        Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
945 >        int h = spread(key.hashCode());
946 >        if ((tab = table) != null && (n = tab.length) > 0 &&
947 >            (e = tabAt(tab, (n - 1) & h)) != null) {
948 >            if ((eh = e.hash) == h) {
949 >                if ((ek = e.key) == key || (ek != null && key.equals(ek)))
950 >                    return e.val;
951 >            }
952 >            else if (eh < 0)
953 >                return (p = e.find(h, key)) != null ? p.val : null;
954 >            while ((e = e.next) != null) {
955 >                if (e.hash == h &&
956 >                    ((ek = e.key) == key || (ek != null && key.equals(ek))))
957 >                    return e.val;
958 >            }
959 >        }
960 >        return null;
961      }
962  
963      /**
964       * Tests if the specified object is a key in this table.
965       *
966 <     * @param  key   possible key
966 >     * @param  key possible key
967       * @return {@code true} if and only if the specified object
968       *         is a key in this table, as determined by the
969       *         {@code equals} method; {@code false} otherwise
970       * @throws NullPointerException if the specified key is null
971       */
972      public boolean containsKey(Object key) {
973 <        return internalGet(key) != null;
973 >        return get(key) != null;
974      }
975  
976      /**
# Line 2596 | Line 986 | public class ConcurrentHashMapV8<K, V>
986      public boolean containsValue(Object value) {
987          if (value == null)
988              throw new NullPointerException();
989 <        V v;
990 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
991 <        while ((v = it.advance()) != null) {
992 <            if (v == value || value.equals(v))
993 <                return true;
989 >        Node<K,V>[] t;
990 >        if ((t = table) != null) {
991 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
992 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
993 >                V v;
994 >                if ((v = p.val) == value || (v != null && value.equals(v)))
995 >                    return true;
996 >            }
997          }
998          return false;
999      }
1000  
1001      /**
2609     * Legacy method testing if some key maps into the specified value
2610     * in this table.  This method is identical in functionality to
2611     * {@link #containsValue}, and exists solely to ensure
2612     * full compatibility with class {@link java.util.Hashtable},
2613     * which supported this method prior to introduction of the
2614     * Java Collections framework.
2615     *
2616     * @param  value a value to search for
2617     * @return {@code true} if and only if some key maps to the
2618     *         {@code value} argument in this table as
2619     *         determined by the {@code equals} method;
2620     *         {@code false} otherwise
2621     * @throws NullPointerException if the specified value is null
2622     */
2623    @Deprecated public boolean contains(Object value) {
2624        return containsValue(value);
2625    }
2626
2627    /**
1002       * Maps the specified key to the specified value in this table.
1003       * Neither the key nor the value can be null.
1004       *
# Line 2638 | Line 1012 | public class ConcurrentHashMapV8<K, V>
1012       * @throws NullPointerException if the specified key or value is null
1013       */
1014      public V put(K key, V value) {
1015 <        return internalPut(key, value, false);
1015 >        return putVal(key, value, false);
1016      }
1017  
1018 <    /**
1019 <     * {@inheritDoc}
1020 <     *
1021 <     * @return the previous value associated with the specified key,
1022 <     *         or {@code null} if there was no mapping for the key
1023 <     * @throws NullPointerException if the specified key or value is null
1024 <     */
1025 <    public V putIfAbsent(K key, V value) {
1026 <        return internalPut(key, value, true);
1018 >    /** Implementation for put and putIfAbsent */
1019 >    final V putVal(K key, V value, boolean onlyIfAbsent) {
1020 >        if (key == null || value == null) throw new NullPointerException();
1021 >        int hash = spread(key.hashCode());
1022 >        int binCount = 0;
1023 >        for (Node<K,V>[] tab = table;;) {
1024 >            Node<K,V> f; int n, i, fh;
1025 >            if (tab == null || (n = tab.length) == 0)
1026 >                tab = initTable();
1027 >            else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1028 >                if (casTabAt(tab, i, null,
1029 >                             new Node<K,V>(hash, key, value, null)))
1030 >                    break;                   // no lock when adding to empty bin
1031 >            }
1032 >            else if ((fh = f.hash) == MOVED)
1033 >                tab = helpTransfer(tab, f);
1034 >            else {
1035 >                V oldVal = null;
1036 >                synchronized (f) {
1037 >                    if (tabAt(tab, i) == f) {
1038 >                        if (fh >= 0) {
1039 >                            binCount = 1;
1040 >                            for (Node<K,V> e = f;; ++binCount) {
1041 >                                K ek;
1042 >                                if (e.hash == hash &&
1043 >                                    ((ek = e.key) == key ||
1044 >                                     (ek != null && key.equals(ek)))) {
1045 >                                    oldVal = e.val;
1046 >                                    if (!onlyIfAbsent)
1047 >                                        e.val = value;
1048 >                                    break;
1049 >                                }
1050 >                                Node<K,V> pred = e;
1051 >                                if ((e = e.next) == null) {
1052 >                                    pred.next = new Node<K,V>(hash, key,
1053 >                                                              value, null);
1054 >                                    break;
1055 >                                }
1056 >                            }
1057 >                        }
1058 >                        else if (f instanceof TreeBin) {
1059 >                            Node<K,V> p;
1060 >                            binCount = 2;
1061 >                            if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1062 >                                                           value)) != null) {
1063 >                                oldVal = p.val;
1064 >                                if (!onlyIfAbsent)
1065 >                                    p.val = value;
1066 >                            }
1067 >                        }
1068 >                    }
1069 >                }
1070 >                if (binCount != 0) {
1071 >                    if (binCount >= TREEIFY_THRESHOLD)
1072 >                        treeifyBin(tab, i);
1073 >                    if (oldVal != null)
1074 >                        return oldVal;
1075 >                    break;
1076 >                }
1077 >            }
1078 >        }
1079 >        addCount(1L, binCount);
1080 >        return null;
1081      }
1082  
1083      /**
# Line 2660 | Line 1088 | public class ConcurrentHashMapV8<K, V>
1088       * @param m mappings to be stored in this map
1089       */
1090      public void putAll(Map<? extends K, ? extends V> m) {
1091 <        internalPutAll(m);
1092 <    }
1093 <
2666 <    /**
2667 <     * If the specified key is not already associated with a value,
2668 <     * computes its value using the given mappingFunction and enters
2669 <     * it into the map unless null.  This is equivalent to
2670 <     * <pre> {@code
2671 <     * if (map.containsKey(key))
2672 <     *   return map.get(key);
2673 <     * value = mappingFunction.apply(key);
2674 <     * if (value != null)
2675 <     *   map.put(key, value);
2676 <     * return value;}</pre>
2677 <     *
2678 <     * except that the action is performed atomically.  If the
2679 <     * function returns {@code null} no mapping is recorded. If the
2680 <     * function itself throws an (unchecked) exception, the exception
2681 <     * is rethrown to its caller, and no mapping is recorded.  Some
2682 <     * attempted update operations on this map by other threads may be
2683 <     * blocked while computation is in progress, so the computation
2684 <     * should be short and simple, and must not attempt to update any
2685 <     * other mappings of this Map. The most appropriate usage is to
2686 <     * construct a new object serving as an initial mapped value, or
2687 <     * memoized result, as in:
2688 <     *
2689 <     *  <pre> {@code
2690 <     * map.computeIfAbsent(key, new Fun<K, V>() {
2691 <     *   public V map(K k) { return new Value(f(k)); }});}</pre>
2692 <     *
2693 <     * @param key key with which the specified value is to be associated
2694 <     * @param mappingFunction the function to compute a value
2695 <     * @return the current (existing or computed) value associated with
2696 <     *         the specified key, or null if the computed value is null
2697 <     * @throws NullPointerException if the specified key or mappingFunction
2698 <     *         is null
2699 <     * @throws IllegalStateException if the computation detectably
2700 <     *         attempts a recursive update to this map that would
2701 <     *         otherwise never complete
2702 <     * @throws RuntimeException or Error if the mappingFunction does so,
2703 <     *         in which case the mapping is left unestablished
2704 <     */
2705 <    public V computeIfAbsent
2706 <        (K key, Fun<? super K, ? extends V> mappingFunction) {
2707 <        return internalComputeIfAbsent(key, mappingFunction);
2708 <    }
2709 <
2710 <    /**
2711 <     * If the given key is present, computes a new mapping value given a key and
2712 <     * its current mapped value. This is equivalent to
2713 <     *  <pre> {@code
2714 <     *   if (map.containsKey(key)) {
2715 <     *     value = remappingFunction.apply(key, map.get(key));
2716 <     *     if (value != null)
2717 <     *       map.put(key, value);
2718 <     *     else
2719 <     *       map.remove(key);
2720 <     *   }
2721 <     * }</pre>
2722 <     *
2723 <     * except that the action is performed atomically.  If the
2724 <     * function returns {@code null}, the mapping is removed.  If the
2725 <     * function itself throws an (unchecked) exception, the exception
2726 <     * is rethrown to its caller, and the current mapping is left
2727 <     * unchanged.  Some attempted update operations on this map by
2728 <     * other threads may be blocked while computation is in progress,
2729 <     * so the computation should be short and simple, and must not
2730 <     * attempt to update any other mappings of this Map. For example,
2731 <     * to either create or append new messages to a value mapping:
2732 <     *
2733 <     * @param key key with which the specified value is to be associated
2734 <     * @param remappingFunction the function to compute a value
2735 <     * @return the new value associated with the specified key, or null if none
2736 <     * @throws NullPointerException if the specified key or remappingFunction
2737 <     *         is null
2738 <     * @throws IllegalStateException if the computation detectably
2739 <     *         attempts a recursive update to this map that would
2740 <     *         otherwise never complete
2741 <     * @throws RuntimeException or Error if the remappingFunction does so,
2742 <     *         in which case the mapping is unchanged
2743 <     */
2744 <    public V computeIfPresent
2745 <        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2746 <        return internalCompute(key, true, remappingFunction);
2747 <    }
2748 <
2749 <    /**
2750 <     * Computes a new mapping value given a key and
2751 <     * its current mapped value (or {@code null} if there is no current
2752 <     * mapping). This is equivalent to
2753 <     *  <pre> {@code
2754 <     *   value = remappingFunction.apply(key, map.get(key));
2755 <     *   if (value != null)
2756 <     *     map.put(key, value);
2757 <     *   else
2758 <     *     map.remove(key);
2759 <     * }</pre>
2760 <     *
2761 <     * except that the action is performed atomically.  If the
2762 <     * function returns {@code null}, the mapping is removed.  If the
2763 <     * function itself throws an (unchecked) exception, the exception
2764 <     * is rethrown to its caller, and the current mapping is left
2765 <     * unchanged.  Some attempted update operations on this map by
2766 <     * other threads may be blocked while computation is in progress,
2767 <     * so the computation should be short and simple, and must not
2768 <     * attempt to update any other mappings of this Map. For example,
2769 <     * to either create or append new messages to a value mapping:
2770 <     *
2771 <     * <pre> {@code
2772 <     * Map<Key, String> map = ...;
2773 <     * final String msg = ...;
2774 <     * map.compute(key, new BiFun<Key, String, String>() {
2775 <     *   public String apply(Key k, String v) {
2776 <     *    return (v == null) ? msg : v + msg;});}}</pre>
2777 <     *
2778 <     * @param key key with which the specified value is to be associated
2779 <     * @param remappingFunction the function to compute a value
2780 <     * @return the new value associated with the specified key, or null if none
2781 <     * @throws NullPointerException if the specified key or remappingFunction
2782 <     *         is null
2783 <     * @throws IllegalStateException if the computation detectably
2784 <     *         attempts a recursive update to this map that would
2785 <     *         otherwise never complete
2786 <     * @throws RuntimeException or Error if the remappingFunction does so,
2787 <     *         in which case the mapping is unchanged
2788 <     */
2789 <    public V compute
2790 <        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2791 <        return internalCompute(key, false, remappingFunction);
2792 <    }
2793 <
2794 <    /**
2795 <     * If the specified key is not already associated
2796 <     * with a value, associate it with the given value.
2797 <     * Otherwise, replace the value with the results of
2798 <     * the given remapping function. This is equivalent to:
2799 <     *  <pre> {@code
2800 <     *   if (!map.containsKey(key))
2801 <     *     map.put(value);
2802 <     *   else {
2803 <     *     newValue = remappingFunction.apply(map.get(key), value);
2804 <     *     if (value != null)
2805 <     *       map.put(key, value);
2806 <     *     else
2807 <     *       map.remove(key);
2808 <     *   }
2809 <     * }</pre>
2810 <     * except that the action is performed atomically.  If the
2811 <     * function returns {@code null}, the mapping is removed.  If the
2812 <     * function itself throws an (unchecked) exception, the exception
2813 <     * is rethrown to its caller, and the current mapping is left
2814 <     * unchanged.  Some attempted update operations on this map by
2815 <     * other threads may be blocked while computation is in progress,
2816 <     * so the computation should be short and simple, and must not
2817 <     * attempt to update any other mappings of this Map.
2818 <     */
2819 <    public V merge
2820 <        (K key, V value,
2821 <         BiFun<? super V, ? super V, ? extends V> remappingFunction) {
2822 <        return internalMerge(key, value, remappingFunction);
1091 >        tryPresize(m.size());
1092 >        for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1093 >            putVal(e.getKey(), e.getValue(), false);
1094      }
1095  
1096      /**
# Line 2832 | Line 1103 | public class ConcurrentHashMapV8<K, V>
1103       * @throws NullPointerException if the specified key is null
1104       */
1105      public V remove(Object key) {
1106 <        return internalReplace(key, null, null);
1106 >        return replaceNode(key, null, null);
1107      }
1108  
1109      /**
1110 <     * {@inheritDoc}
1111 <     *
1112 <     * @throws NullPointerException if the specified key is null
2842 <     */
2843 <    public boolean remove(Object key, Object value) {
2844 <        return value != null && internalReplace(key, null, value) != null;
2845 <    }
2846 <
2847 <    /**
2848 <     * {@inheritDoc}
2849 <     *
2850 <     * @throws NullPointerException if any of the arguments are null
2851 <     */
2852 <    public boolean replace(K key, V oldValue, V newValue) {
2853 <        if (key == null || oldValue == null || newValue == null)
2854 <            throw new NullPointerException();
2855 <        return internalReplace(key, newValue, oldValue) != null;
2856 <    }
2857 <
2858 <    /**
2859 <     * {@inheritDoc}
2860 <     *
2861 <     * @return the previous value associated with the specified key,
2862 <     *         or {@code null} if there was no mapping for the key
2863 <     * @throws NullPointerException if the specified key or value is null
1110 >     * Implementation for the four public remove/replace methods:
1111 >     * Replaces node value with v, conditional upon match of cv if
1112 >     * non-null.  If resulting value is null, delete.
1113       */
1114 <    public V replace(K key, V value) {
1115 <        if (key == null || value == null)
1116 <            throw new NullPointerException();
1117 <        return internalReplace(key, value, null);
1114 >    final V replaceNode(Object key, V value, Object cv) {
1115 >        int hash = spread(key.hashCode());
1116 >        for (Node<K,V>[] tab = table;;) {
1117 >            Node<K,V> f; int n, i, fh;
1118 >            if (tab == null || (n = tab.length) == 0 ||
1119 >                (f = tabAt(tab, i = (n - 1) & hash)) == null)
1120 >                break;
1121 >            else if ((fh = f.hash) == MOVED)
1122 >                tab = helpTransfer(tab, f);
1123 >            else {
1124 >                V oldVal = null;
1125 >                boolean validated = false;
1126 >                synchronized (f) {
1127 >                    if (tabAt(tab, i) == f) {
1128 >                        if (fh >= 0) {
1129 >                            validated = true;
1130 >                            for (Node<K,V> e = f, pred = null;;) {
1131 >                                K ek;
1132 >                                if (e.hash == hash &&
1133 >                                    ((ek = e.key) == key ||
1134 >                                     (ek != null && key.equals(ek)))) {
1135 >                                    V ev = e.val;
1136 >                                    if (cv == null || cv == ev ||
1137 >                                        (ev != null && cv.equals(ev))) {
1138 >                                        oldVal = ev;
1139 >                                        if (value != null)
1140 >                                            e.val = value;
1141 >                                        else if (pred != null)
1142 >                                            pred.next = e.next;
1143 >                                        else
1144 >                                            setTabAt(tab, i, e.next);
1145 >                                    }
1146 >                                    break;
1147 >                                }
1148 >                                pred = e;
1149 >                                if ((e = e.next) == null)
1150 >                                    break;
1151 >                            }
1152 >                        }
1153 >                        else if (f instanceof TreeBin) {
1154 >                            validated = true;
1155 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1156 >                            TreeNode<K,V> r, p;
1157 >                            if ((r = t.root) != null &&
1158 >                                (p = r.findTreeNode(hash, key, null)) != null) {
1159 >                                V pv = p.val;
1160 >                                if (cv == null || cv == pv ||
1161 >                                    (pv != null && cv.equals(pv))) {
1162 >                                    oldVal = pv;
1163 >                                    if (value != null)
1164 >                                        p.val = value;
1165 >                                    else if (t.removeTreeNode(p))
1166 >                                        setTabAt(tab, i, untreeify(t.first));
1167 >                                }
1168 >                            }
1169 >                        }
1170 >                    }
1171 >                }
1172 >                if (validated) {
1173 >                    if (oldVal != null) {
1174 >                        if (value == null)
1175 >                            addCount(-1L, -1);
1176 >                        return oldVal;
1177 >                    }
1178 >                    break;
1179 >                }
1180 >            }
1181 >        }
1182 >        return null;
1183      }
1184  
1185      /**
1186       * Removes all of the mappings from this map.
1187       */
1188      public void clear() {
1189 <        internalClear();
1189 >        long delta = 0L; // negative number of deletions
1190 >        int i = 0;
1191 >        Node<K,V>[] tab = table;
1192 >        while (tab != null && i < tab.length) {
1193 >            int fh;
1194 >            Node<K,V> f = tabAt(tab, i);
1195 >            if (f == null)
1196 >                ++i;
1197 >            else if ((fh = f.hash) == MOVED) {
1198 >                tab = helpTransfer(tab, f);
1199 >                i = 0; // restart
1200 >            }
1201 >            else {
1202 >                synchronized (f) {
1203 >                    if (tabAt(tab, i) == f) {
1204 >                        Node<K,V> p = (fh >= 0 ? f :
1205 >                                       (f instanceof TreeBin) ?
1206 >                                       ((TreeBin<K,V>)f).first : null);
1207 >                        while (p != null) {
1208 >                            --delta;
1209 >                            p = p.next;
1210 >                        }
1211 >                        setTabAt(tab, i++, null);
1212 >                    }
1213 >                }
1214 >            }
1215 >        }
1216 >        if (delta != 0L)
1217 >            addCount(delta, -1);
1218      }
1219  
1220      /**
1221       * Returns a {@link Set} view of the keys contained in this map.
1222       * The set is backed by the map, so changes to the map are
1223 <     * reflected in the set, and vice-versa.
1223 >     * reflected in the set, and vice-versa. The set supports element
1224 >     * removal, which removes the corresponding mapping from this map,
1225 >     * via the {@code Iterator.remove}, {@code Set.remove},
1226 >     * {@code removeAll}, {@code retainAll}, and {@code clear}
1227 >     * operations.  It does not support the {@code add} or
1228 >     * {@code addAll} operations.
1229       *
1230 <     * @return the set view
1231 <     */
1232 <    public KeySetView<K,V> keySet() {
1233 <        KeySetView<K,V> ks = keySet;
1234 <        return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2888 <    }
2889 <
2890 <    /**
2891 <     * Returns a {@link Set} view of the keys in this map, using the
2892 <     * given common mapped value for any additions (i.e., {@link
2893 <     * Collection#add} and {@link Collection#addAll}). This is of
2894 <     * course only appropriate if it is acceptable to use the same
2895 <     * value for all additions from this view.
1230 >     * <p>The view's {@code iterator} is a "weakly consistent" iterator
1231 >     * that will never throw {@link ConcurrentModificationException},
1232 >     * and guarantees to traverse elements as they existed upon
1233 >     * construction of the iterator, and may (but is not guaranteed to)
1234 >     * reflect any modifications subsequent to construction.
1235       *
2897     * @param mappedValue the mapped value to use for any
2898     * additions.
1236       * @return the set view
2900     * @throws NullPointerException if the mappedValue is null
1237       */
1238 <    public KeySetView<K,V> keySet(V mappedValue) {
1239 <        if (mappedValue == null)
1240 <            throw new NullPointerException();
2905 <        return new KeySetView<K,V>(this, mappedValue);
1238 >    public KeySetView<K,V> keySet() {
1239 >        KeySetView<K,V> ks;
1240 >        return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1241      }
1242  
1243      /**
1244       * Returns a {@link Collection} view of the values contained in this map.
1245       * The collection is backed by the map, so changes to the map are
1246 <     * reflected in the collection, and vice-versa.
1246 >     * reflected in the collection, and vice-versa.  The collection
1247 >     * supports element removal, which removes the corresponding
1248 >     * mapping from this map, via the {@code Iterator.remove},
1249 >     * {@code Collection.remove}, {@code removeAll},
1250 >     * {@code retainAll}, and {@code clear} operations.  It does not
1251 >     * support the {@code add} or {@code addAll} operations.
1252 >     *
1253 >     * <p>The view's {@code iterator} is a "weakly consistent" iterator
1254 >     * that will never throw {@link ConcurrentModificationException},
1255 >     * and guarantees to traverse elements as they existed upon
1256 >     * construction of the iterator, and may (but is not guaranteed to)
1257 >     * reflect any modifications subsequent to construction.
1258 >     *
1259 >     * @return the collection view
1260       */
1261 <    public ValuesView<K,V> values() {
1262 <        ValuesView<K,V> vs = values;
1263 <        return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
1261 >    public Collection<V> values() {
1262 >        ValuesView<K,V> vs;
1263 >        return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1264      }
1265  
1266      /**
# Line 2922 | Line 1270 | public class ConcurrentHashMapV8<K, V>
1270       * removal, which removes the corresponding mapping from the map,
1271       * via the {@code Iterator.remove}, {@code Set.remove},
1272       * {@code removeAll}, {@code retainAll}, and {@code clear}
1273 <     * operations.  It does not support the {@code add} or
2926 <     * {@code addAll} operations.
1273 >     * operations.
1274       *
1275       * <p>The view's {@code iterator} is a "weakly consistent" iterator
1276       * that will never throw {@link ConcurrentModificationException},
1277       * and guarantees to traverse elements as they existed upon
1278       * construction of the iterator, and may (but is not guaranteed to)
1279       * reflect any modifications subsequent to construction.
2933     */
2934    public Set<Map.Entry<K,V>> entrySet() {
2935        EntrySetView<K,V> es = entrySet;
2936        return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2937    }
2938
2939    /**
2940     * Returns an enumeration of the keys in this table.
2941     *
2942     * @return an enumeration of the keys in this table
2943     * @see #keySet()
2944     */
2945    public Enumeration<K> keys() {
2946        return new KeyIterator<K,V>(this);
2947    }
2948
2949    /**
2950     * Returns an enumeration of the values in this table.
1280       *
1281 <     * @return an enumeration of the values in this table
2953 <     * @see #values()
2954 <     */
2955 <    public Enumeration<V> elements() {
2956 <        return new ValueIterator<K,V>(this);
2957 <    }
2958 <
2959 <    /**
2960 <     * Returns a partitionable iterator of the keys in this map.
2961 <     *
2962 <     * @return a partitionable iterator of the keys in this map
2963 <     */
2964 <    public Spliterator<K> keySpliterator() {
2965 <        return new KeyIterator<K,V>(this);
2966 <    }
2967 <
2968 <    /**
2969 <     * Returns a partitionable iterator of the values in this map.
2970 <     *
2971 <     * @return a partitionable iterator of the values in this map
2972 <     */
2973 <    public Spliterator<V> valueSpliterator() {
2974 <        return new ValueIterator<K,V>(this);
2975 <    }
2976 <
2977 <    /**
2978 <     * Returns a partitionable iterator of the entries in this map.
2979 <     *
2980 <     * @return a partitionable iterator of the entries in this map
1281 >     * @return the set view
1282       */
1283 <    public Spliterator<Map.Entry<K,V>> entrySpliterator() {
1284 <        return new EntryIterator<K,V>(this);
1283 >    public Set<Map.Entry<K,V>> entrySet() {
1284 >        EntrySetView<K,V> es;
1285 >        return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1286      }
1287  
1288      /**
# Line 2992 | Line 1294 | public class ConcurrentHashMapV8<K, V>
1294       */
1295      public int hashCode() {
1296          int h = 0;
1297 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1298 <        V v;
1299 <        while ((v = it.advance()) != null) {
1300 <            h += it.nextKey.hashCode() ^ v.hashCode();
1297 >        Node<K,V>[] t;
1298 >        if ((t = table) != null) {
1299 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1300 >            for (Node<K,V> p; (p = it.advance()) != null; )
1301 >                h += p.key.hashCode() ^ p.val.hashCode();
1302          }
1303          return h;
1304      }
# Line 3012 | Line 1315 | public class ConcurrentHashMapV8<K, V>
1315       * @return a string representation of this map
1316       */
1317      public String toString() {
1318 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1318 >        Node<K,V>[] t;
1319 >        int f = (t = table) == null ? 0 : t.length;
1320 >        Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1321          StringBuilder sb = new StringBuilder();
1322          sb.append('{');
1323 <        V v;
1324 <        if ((v = it.advance()) != null) {
1323 >        Node<K,V> p;
1324 >        if ((p = it.advance()) != null) {
1325              for (;;) {
1326 <                Object k = it.nextKey;
1326 >                K k = p.key;
1327 >                V v = p.val;
1328                  sb.append(k == this ? "(this Map)" : k);
1329                  sb.append('=');
1330                  sb.append(v == this ? "(this Map)" : v);
1331 <                if ((v = it.advance()) == null)
1331 >                if ((p = it.advance()) == null)
1332                      break;
1333                  sb.append(',').append(' ');
1334              }
# Line 3045 | Line 1351 | public class ConcurrentHashMapV8<K, V>
1351              if (!(o instanceof Map))
1352                  return false;
1353              Map<?,?> m = (Map<?,?>) o;
1354 <            Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1355 <            V val;
1356 <            while ((val = it.advance()) != null) {
1357 <                Object v = m.get(it.nextKey);
1354 >            Node<K,V>[] t;
1355 >            int f = (t = table) == null ? 0 : t.length;
1356 >            Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1357 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1358 >                V val = p.val;
1359 >                Object v = m.get(p.key);
1360                  if (v == null || (v != val && !v.equals(val)))
1361                      return false;
1362              }
# Line 3056 | Line 1364 | public class ConcurrentHashMapV8<K, V>
1364                  Object mk, mv, v;
1365                  if ((mk = e.getKey()) == null ||
1366                      (mv = e.getValue()) == null ||
1367 <                    (v = internalGet(mk)) == null ||
1367 >                    (v = get(mk)) == null ||
1368                      (mv != v && !mv.equals(v)))
1369                      return false;
1370              }
# Line 3064 | Line 1372 | public class ConcurrentHashMapV8<K, V>
1372          return true;
1373      }
1374  
3067    /* ----------------Iterators -------------- */
3068
3069    @SuppressWarnings("serial") static final class KeyIterator<K,V>
3070        extends Traverser<K,V,Object>
3071        implements Spliterator<K>, Enumeration<K> {
3072        KeyIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3073        KeyIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
3074            super(map, it, -1);
3075        }
3076        public KeyIterator<K,V> split() {
3077            if (nextKey != null)
3078                throw new IllegalStateException();
3079            return new KeyIterator<K,V>(map, this);
3080        }
3081        @SuppressWarnings("unchecked") public final K next() {
3082            if (nextVal == null && advance() == null)
3083                throw new NoSuchElementException();
3084            Object k = nextKey;
3085            nextVal = null;
3086            return (K) k;
3087        }
3088
3089        public final K nextElement() { return next(); }
3090    }
3091
3092    @SuppressWarnings("serial") static final class ValueIterator<K,V>
3093        extends Traverser<K,V,Object>
3094        implements Spliterator<V>, Enumeration<V> {
3095        ValueIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3096        ValueIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
3097            super(map, it, -1);
3098        }
3099        public ValueIterator<K,V> split() {
3100            if (nextKey != null)
3101                throw new IllegalStateException();
3102            return new ValueIterator<K,V>(map, this);
3103        }
3104
3105        public final V next() {
3106            V v;
3107            if ((v = nextVal) == null && (v = advance()) == null)
3108                throw new NoSuchElementException();
3109            nextVal = null;
3110            return v;
3111        }
3112
3113        public final V nextElement() { return next(); }
3114    }
3115
3116    @SuppressWarnings("serial") static final class EntryIterator<K,V>
3117        extends Traverser<K,V,Object>
3118        implements Spliterator<Map.Entry<K,V>> {
3119        EntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
3120        EntryIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
3121            super(map, it, -1);
3122        }
3123        public EntryIterator<K,V> split() {
3124            if (nextKey != null)
3125                throw new IllegalStateException();
3126            return new EntryIterator<K,V>(map, this);
3127        }
3128
3129        @SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
3130            V v;
3131            if ((v = nextVal) == null && (v = advance()) == null)
3132                throw new NoSuchElementException();
3133            Object k = nextKey;
3134            nextVal = null;
3135            return new MapEntry<K,V>((K)k, v, map);
3136        }
3137    }
3138
3139    /**
3140     * Exported Entry for iterators
3141     */
3142    static final class MapEntry<K,V> implements Map.Entry<K, V> {
3143        final K key; // non-null
3144        V val;       // non-null
3145        final ConcurrentHashMapV8<K, V> map;
3146        MapEntry(K key, V val, ConcurrentHashMapV8<K, V> map) {
3147            this.key = key;
3148            this.val = val;
3149            this.map = map;
3150        }
3151        public final K getKey()       { return key; }
3152        public final V getValue()     { return val; }
3153        public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3154        public final String toString(){ return key + "=" + val; }
3155
3156        public final boolean equals(Object o) {
3157            Object k, v; Map.Entry<?,?> e;
3158            return ((o instanceof Map.Entry) &&
3159                    (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3160                    (v = e.getValue()) != null &&
3161                    (k == key || k.equals(key)) &&
3162                    (v == val || v.equals(val)));
3163        }
3164
3165        /**
3166         * Sets our entry's value and writes through to the map. The
3167         * value to return is somewhat arbitrary here. Since we do not
3168         * necessarily track asynchronous changes, the most recent
3169         * "previous" value could be different from what we return (or
3170         * could even have been removed in which case the put will
3171         * re-establish). We do not and cannot guarantee more.
3172         */
3173        public final V setValue(V value) {
3174            if (value == null) throw new NullPointerException();
3175            V v = val;
3176            val = value;
3177            map.put(key, value);
3178            return v;
3179        }
3180    }
3181
3182    /**
3183     * Returns exportable snapshot entry for the given key and value
3184     * when write-through can't or shouldn't be used.
3185     */
3186    static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3187        return new AbstractMap.SimpleEntry<K,V>(k, v);
3188    }
3189
3190    /* ---------------- Serialization Support -------------- */
3191
1375      /**
1376       * Stripped-down version of helper class used in previous version,
1377       * declared for the sake of serialization compatibility
1378       */
1379 <    static class Segment<K,V> implements Serializable {
1379 >    static class Segment<K,V> extends ReentrantLock implements Serializable {
1380          private static final long serialVersionUID = 2249069246763182397L;
1381          final float loadFactor;
1382          Segment(float lf) { this.loadFactor = lf; }
# Line 3203 | Line 1386 | public class ConcurrentHashMapV8<K, V>
1386       * Saves the state of the {@code ConcurrentHashMapV8} instance to a
1387       * stream (i.e., serializes it).
1388       * @param s the stream
1389 +     * @throws java.io.IOException if an I/O error occurs
1390       * @serialData
1391       * the key (Object) and value (Object)
1392       * for each key-value mapping, followed by a null pair.
1393       * The key-value mappings are emitted in no particular order.
1394       */
1395 <    @SuppressWarnings("unchecked") private void writeObject
3212 <        (java.io.ObjectOutputStream s)
1395 >    private void writeObject(java.io.ObjectOutputStream s)
1396          throws java.io.IOException {
1397 <        if (segments == null) { // for serialization compatibility
1398 <            segments = (Segment<K,V>[])
1399 <                new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1400 <            for (int i = 0; i < segments.length; ++i)
1401 <                segments[i] = new Segment<K,V>(LOAD_FACTOR);
1402 <        }
1403 <        s.defaultWriteObject();
1404 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1405 <        V v;
1406 <        while ((v = it.advance()) != null) {
1407 <            s.writeObject(it.nextKey);
1408 <            s.writeObject(v);
1397 >        // For serialization compatibility
1398 >        // Emulate segment calculation from previous version of this class
1399 >        int sshift = 0;
1400 >        int ssize = 1;
1401 >        while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1402 >            ++sshift;
1403 >            ssize <<= 1;
1404 >        }
1405 >        int segmentShift = 32 - sshift;
1406 >        int segmentMask = ssize - 1;
1407 >        @SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1408 >            new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1409 >        for (int i = 0; i < segments.length; ++i)
1410 >            segments[i] = new Segment<K,V>(LOAD_FACTOR);
1411 >        s.putFields().put("segments", segments);
1412 >        s.putFields().put("segmentShift", segmentShift);
1413 >        s.putFields().put("segmentMask", segmentMask);
1414 >        s.writeFields();
1415 >
1416 >        Node<K,V>[] t;
1417 >        if ((t = table) != null) {
1418 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1419 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1420 >                s.writeObject(p.key);
1421 >                s.writeObject(p.val);
1422 >            }
1423          }
1424          s.writeObject(null);
1425          s.writeObject(null);
# Line 3232 | Line 1429 | public class ConcurrentHashMapV8<K, V>
1429      /**
1430       * Reconstitutes the instance from a stream (that is, deserializes it).
1431       * @param s the stream
1432 +     * @throws ClassNotFoundException if the class of a serialized object
1433 +     *         could not be found
1434 +     * @throws java.io.IOException if an I/O error occurs
1435       */
1436 <    @SuppressWarnings("unchecked") private void readObject
3237 <        (java.io.ObjectInputStream s)
1436 >    private void readObject(java.io.ObjectInputStream s)
1437          throws java.io.IOException, ClassNotFoundException {
1438 +        /*
1439 +         * To improve performance in typical cases, we create nodes
1440 +         * while reading, then place in table once size is known.
1441 +         * However, we must also validate uniqueness and deal with
1442 +         * overpopulated bins while doing so, which requires
1443 +         * specialized versions of putVal mechanics.
1444 +         */
1445 +        sizeCtl = -1; // force exclusion for table construction
1446          s.defaultReadObject();
3240        this.segments = null; // unneeded
3241
3242        // Create all nodes, then place in table once size is known
1447          long size = 0L;
1448 <        Node<V> p = null;
1448 >        Node<K,V> p = null;
1449          for (;;) {
1450 <            K k = (K) s.readObject();
1451 <            V v = (V) s.readObject();
1450 >            @SuppressWarnings("unchecked") K k = (K) s.readObject();
1451 >            @SuppressWarnings("unchecked") V v = (V) s.readObject();
1452              if (k != null && v != null) {
1453 <                int h = spread(k.hashCode());
3250 <                p = new Node<V>(h, k, v, p);
1453 >                p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1454                  ++size;
1455              }
1456              else
1457                  break;
1458          }
1459 <        if (p != null) {
1460 <            boolean init = false;
1459 >        if (size == 0L)
1460 >            sizeCtl = 0;
1461 >        else {
1462              int n;
1463              if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1464                  n = MAXIMUM_CAPACITY;
# Line 3262 | Line 1466 | public class ConcurrentHashMapV8<K, V>
1466                  int sz = (int)size;
1467                  n = tableSizeFor(sz + (sz >>> 1) + 1);
1468              }
1469 <            int sc = sizeCtl;
1470 <            boolean collide = false;
1471 <            if (n > sc &&
1472 <                U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1473 <                try {
1474 <                    if (table == null) {
1475 <                        init = true;
1476 <                        @SuppressWarnings("rawtypes") Node[] rt = new Node[n];
1477 <                        Node<V>[] tab = (Node<V>[])rt;
1478 <                        int mask = n - 1;
1479 <                        while (p != null) {
1480 <                            int j = p.hash & mask;
1481 <                            Node<V> next = p.next;
1482 <                            Node<V> q = p.next = tabAt(tab, j);
1483 <                            setTabAt(tab, j, p);
1484 <                            if (!collide && q != null && q.hash == p.hash)
1485 <                                collide = true;
3282 <                            p = next;
3283 <                        }
3284 <                        table = tab;
3285 <                        addCount(size, -1);
3286 <                        sc = n - (n >>> 2);
1469 >            @SuppressWarnings("unchecked")
1470 >                Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1471 >            int mask = n - 1;
1472 >            long added = 0L;
1473 >            while (p != null) {
1474 >                boolean insertAtFront;
1475 >                Node<K,V> next = p.next, first;
1476 >                int h = p.hash, j = h & mask;
1477 >                if ((first = tabAt(tab, j)) == null)
1478 >                    insertAtFront = true;
1479 >                else {
1480 >                    K k = p.key;
1481 >                    if (first.hash < 0) {
1482 >                        TreeBin<K,V> t = (TreeBin<K,V>)first;
1483 >                        if (t.putTreeVal(h, k, p.val) == null)
1484 >                            ++added;
1485 >                        insertAtFront = false;
1486                      }
1487 <                } finally {
1488 <                    sizeCtl = sc;
1489 <                }
1490 <                if (collide) { // rescan and convert to TreeBins
1491 <                    Node<V>[] tab = table;
1492 <                    for (int i = 0; i < tab.length; ++i) {
1493 <                        int c = 0;
1494 <                        for (Node<V> e = tabAt(tab, i); e != null; e = e.next) {
1495 <                            if (++c > TREE_THRESHOLD &&
3297 <                                (e.key instanceof Comparable)) {
3298 <                                replaceWithTreeBin(tab, i, e.key);
1487 >                    else {
1488 >                        int binCount = 0;
1489 >                        insertAtFront = true;
1490 >                        Node<K,V> q; K qk;
1491 >                        for (q = first; q != null; q = q.next) {
1492 >                            if (q.hash == h &&
1493 >                                ((qk = q.key) == k ||
1494 >                                 (qk != null && k.equals(qk)))) {
1495 >                                insertAtFront = false;
1496                                  break;
1497                              }
1498 +                            ++binCount;
1499 +                        }
1500 +                        if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1501 +                            insertAtFront = false;
1502 +                            ++added;
1503 +                            p.next = first;
1504 +                            TreeNode<K,V> hd = null, tl = null;
1505 +                            for (q = p; q != null; q = q.next) {
1506 +                                TreeNode<K,V> t = new TreeNode<K,V>
1507 +                                    (q.hash, q.key, q.val, null, null);
1508 +                                if ((t.prev = tl) == null)
1509 +                                    hd = t;
1510 +                                else
1511 +                                    tl.next = t;
1512 +                                tl = t;
1513 +                            }
1514 +                            setTabAt(tab, j, new TreeBin<K,V>(hd));
1515                          }
1516                      }
1517                  }
1518 <            }
1519 <            if (!init) { // Can only happen if unsafely published.
1520 <                while (p != null) {
1521 <                    internalPut((K)p.key, p.val, false);
3308 <                    p = p.next;
1518 >                if (insertAtFront) {
1519 >                    ++added;
1520 >                    p.next = first;
1521 >                    setTabAt(tab, j, p);
1522                  }
1523 +                p = next;
1524              }
1525 +            table = tab;
1526 +            sizeCtl = n - (n >>> 2);
1527 +            baseCount = added;
1528          }
1529      }
1530  
1531 <    // -------------------------------------------------------
3315 <
3316 <    // Sams
3317 <    /** Interface describing a void action of one argument */
3318 <    public interface Action<A> { void apply(A a); }
3319 <    /** Interface describing a void action of two arguments */
3320 <    public interface BiAction<A,B> { void apply(A a, B b); }
3321 <    /** Interface describing a function of one argument */
3322 <    public interface Fun<A,T> { T apply(A a); }
3323 <    /** Interface describing a function of two arguments */
3324 <    public interface BiFun<A,B,T> { T apply(A a, B b); }
3325 <    /** Interface describing a function of no arguments */
3326 <    public interface Generator<T> { T apply(); }
3327 <    /** Interface describing a function mapping its argument to a double */
3328 <    public interface ObjectToDouble<A> { double apply(A a); }
3329 <    /** Interface describing a function mapping its argument to a long */
3330 <    public interface ObjectToLong<A> { long apply(A a); }
3331 <    /** Interface describing a function mapping its argument to an int */
3332 <    public interface ObjectToInt<A> {int apply(A a); }
3333 <    /** Interface describing a function mapping two arguments to a double */
3334 <    public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
3335 <    /** Interface describing a function mapping two arguments to a long */
3336 <    public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
3337 <    /** Interface describing a function mapping two arguments to an int */
3338 <    public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
3339 <    /** Interface describing a function mapping a double to a double */
3340 <    public interface DoubleToDouble { double apply(double a); }
3341 <    /** Interface describing a function mapping a long to a long */
3342 <    public interface LongToLong { long apply(long a); }
3343 <    /** Interface describing a function mapping an int to an int */
3344 <    public interface IntToInt { int apply(int a); }
3345 <    /** Interface describing a function mapping two doubles to a double */
3346 <    public interface DoubleByDoubleToDouble { double apply(double a, double b); }
3347 <    /** Interface describing a function mapping two longs to a long */
3348 <    public interface LongByLongToLong { long apply(long a, long b); }
3349 <    /** Interface describing a function mapping two ints to an int */
3350 <    public interface IntByIntToInt { int apply(int a, int b); }
3351 <
3352 <
3353 <    // -------------------------------------------------------
3354 <
3355 <    // Sequential bulk operations
1531 >    // ConcurrentMap methods
1532  
1533      /**
1534 <     * Performs the given action for each (key, value).
1534 >     * {@inheritDoc}
1535       *
1536 <     * @param action the action
1536 >     * @return the previous value associated with the specified key,
1537 >     *         or {@code null} if there was no mapping for the key
1538 >     * @throws NullPointerException if the specified key or value is null
1539       */
1540 <    @SuppressWarnings("unchecked") public void forEachSequentially
1541 <        (BiAction<K,V> action) {
3364 <        if (action == null) throw new NullPointerException();
3365 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3366 <        V v;
3367 <        while ((v = it.advance()) != null)
3368 <            action.apply((K)it.nextKey, v);
1540 >    public V putIfAbsent(K key, V value) {
1541 >        return putVal(key, value, true);
1542      }
1543  
1544      /**
1545 <     * Performs the given action for each non-null transformation
3373 <     * of each (key, value).
1545 >     * {@inheritDoc}
1546       *
1547 <     * @param transformer a function returning the transformation
3376 <     * for an element, or null if there is no transformation (in
3377 <     * which case the action is not applied).
3378 <     * @param action the action
1547 >     * @throws NullPointerException if the specified key is null
1548       */
1549 <    @SuppressWarnings("unchecked") public <U> void forEachSequentially
1550 <        (BiFun<? super K, ? super V, ? extends U> transformer,
3382 <         Action<U> action) {
3383 <        if (transformer == null || action == null)
1549 >    public boolean remove(Object key, Object value) {
1550 >        if (key == null)
1551              throw new NullPointerException();
1552 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3386 <        V v; U u;
3387 <        while ((v = it.advance()) != null) {
3388 <            if ((u = transformer.apply((K)it.nextKey, v)) != null)
3389 <                action.apply(u);
3390 <        }
1552 >        return value != null && replaceNode(key, null, value) != null;
1553      }
1554  
1555      /**
1556 <     * Returns a non-null result from applying the given search
3395 <     * function on each (key, value), or null if none.
1556 >     * {@inheritDoc}
1557       *
1558 <     * @param searchFunction a function returning a non-null
3398 <     * result on success, else null
3399 <     * @return a non-null result from applying the given search
3400 <     * function on each (key, value), or null if none
1558 >     * @throws NullPointerException if any of the arguments are null
1559       */
1560 <    @SuppressWarnings("unchecked") public <U> U searchSequentially
1561 <        (BiFun<? super K, ? super V, ? extends U> searchFunction) {
1562 <        if (searchFunction == null) throw new NullPointerException();
1563 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3406 <        V v; U u;
3407 <        while ((v = it.advance()) != null) {
3408 <            if ((u = searchFunction.apply((K)it.nextKey, v)) != null)
3409 <                return u;
3410 <        }
3411 <        return null;
1560 >    public boolean replace(K key, V oldValue, V newValue) {
1561 >        if (key == null || oldValue == null || newValue == null)
1562 >            throw new NullPointerException();
1563 >        return replaceNode(key, newValue, oldValue) != null;
1564      }
1565  
1566      /**
1567 <     * Returns the result of accumulating the given transformation
3416 <     * of all (key, value) pairs using the given reducer to
3417 <     * combine values, or null if none.
1567 >     * {@inheritDoc}
1568       *
1569 <     * @param transformer a function returning the transformation
1570 <     * for an element, or null if there is no transformation (in
1571 <     * which case it is not combined).
3422 <     * @param reducer a commutative associative combining function
3423 <     * @return the result of accumulating the given transformation
3424 <     * of all (key, value) pairs
1569 >     * @return the previous value associated with the specified key,
1570 >     *         or {@code null} if there was no mapping for the key
1571 >     * @throws NullPointerException if the specified key or value is null
1572       */
1573 <    @SuppressWarnings("unchecked") public <U> U reduceSequentially
1574 <        (BiFun<? super K, ? super V, ? extends U> transformer,
3428 <         BiFun<? super U, ? super U, ? extends U> reducer) {
3429 <        if (transformer == null || reducer == null)
1573 >    public V replace(K key, V value) {
1574 >        if (key == null || value == null)
1575              throw new NullPointerException();
1576 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3432 <        U r = null, u; V v;
3433 <        while ((v = it.advance()) != null) {
3434 <            if ((u = transformer.apply((K)it.nextKey, v)) != null)
3435 <                r = (r == null) ? u : reducer.apply(r, u);
3436 <        }
3437 <        return r;
1576 >        return replaceNode(key, value, null);
1577      }
1578  
1579 +    // Overrides of JDK8+ Map extension method defaults
1580 +
1581      /**
1582 <     * Returns the result of accumulating the given transformation
1583 <     * of all (key, value) pairs using the given reducer to
1584 <     * combine values, and the given basis as an identity value.
1582 >     * Returns the value to which the specified key is mapped, or the
1583 >     * given default value if this map contains no mapping for the
1584 >     * key.
1585       *
1586 <     * @param transformer a function returning the transformation
1587 <     * for an element
1588 <     * @param basis the identity (initial default value) for the reduction
1589 <     * @param reducer a commutative associative combining function
1590 <     * @return the result of accumulating the given transformation
3450 <     * of all (key, value) pairs
1586 >     * @param key the key whose associated value is to be returned
1587 >     * @param defaultValue the value to return if this map contains
1588 >     * no mapping for the given key
1589 >     * @return the mapping for the key, if present; else the default value
1590 >     * @throws NullPointerException if the specified key is null
1591       */
1592 <    @SuppressWarnings("unchecked") public double reduceToDoubleSequentially
1593 <        (ObjectByObjectToDouble<? super K, ? super V> transformer,
1594 <         double basis,
1595 <         DoubleByDoubleToDouble reducer) {
1596 <        if (transformer == null || reducer == null)
1597 <            throw new NullPointerException();
1598 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1599 <        double r = basis; V v;
1600 <        while ((v = it.advance()) != null)
1601 <            r = reducer.apply(r, transformer.apply((K)it.nextKey, v));
1602 <        return r;
1592 >    public V getOrDefault(Object key, V defaultValue) {
1593 >        V v;
1594 >        return (v = get(key)) == null ? defaultValue : v;
1595 >    }
1596 >
1597 >    public void forEach(BiAction<? super K, ? super V> action) {
1598 >        if (action == null) throw new NullPointerException();
1599 >        Node<K,V>[] t;
1600 >        if ((t = table) != null) {
1601 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1602 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1603 >                action.apply(p.key, p.val);
1604 >            }
1605 >        }
1606 >    }
1607 >
1608 >    public void replaceAll(BiFun<? super K, ? super V, ? extends V> function) {
1609 >        if (function == null) throw new NullPointerException();
1610 >        Node<K,V>[] t;
1611 >        if ((t = table) != null) {
1612 >            Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1613 >            for (Node<K,V> p; (p = it.advance()) != null; ) {
1614 >                V oldValue = p.val;
1615 >                for (K key = p.key;;) {
1616 >                    V newValue = function.apply(key, oldValue);
1617 >                    if (newValue == null)
1618 >                        throw new NullPointerException();
1619 >                    if (replaceNode(key, newValue, oldValue) != null ||
1620 >                        (oldValue = get(key)) == null)
1621 >                        break;
1622 >                }
1623 >            }
1624 >        }
1625      }
1626  
1627      /**
1628 <     * Returns the result of accumulating the given transformation
1629 <     * of all (key, value) pairs using the given reducer to
1630 <     * combine values, and the given basis as an identity value.
1628 >     * If the specified key is not already associated with a value,
1629 >     * attempts to compute its value using the given mapping function
1630 >     * and enters it into this map unless {@code null}.  The entire
1631 >     * method invocation is performed atomically, so the function is
1632 >     * applied at most once per key.  Some attempted update operations
1633 >     * on this map by other threads may be blocked while computation
1634 >     * is in progress, so the computation should be short and simple,
1635 >     * and must not attempt to update any other mappings of this map.
1636       *
1637 <     * @param transformer a function returning the transformation
1638 <     * for an element
1639 <     * @param basis the identity (initial default value) for the reduction
1640 <     * @param reducer a commutative associative combining function
1641 <     * @return the result of accumulating the given transformation
1642 <     * of all (key, value) pairs
1637 >     * @param key key with which the specified value is to be associated
1638 >     * @param mappingFunction the function to compute a value
1639 >     * @return the current (existing or computed) value associated with
1640 >     *         the specified key, or null if the computed value is null
1641 >     * @throws NullPointerException if the specified key or mappingFunction
1642 >     *         is null
1643 >     * @throws IllegalStateException if the computation detectably
1644 >     *         attempts a recursive update to this map that would
1645 >     *         otherwise never complete
1646 >     * @throws RuntimeException or Error if the mappingFunction does so,
1647 >     *         in which case the mapping is left unestablished
1648       */
1649 <    @SuppressWarnings("unchecked") public long reduceToLongSequentially
1650 <        (ObjectByObjectToLong<? super K, ? super V> transformer,
3479 <         long basis,
3480 <         LongByLongToLong reducer) {
3481 <        if (transformer == null || reducer == null)
1649 >    public V computeIfAbsent(K key, Fun<? super K, ? extends V> mappingFunction) {
1650 >        if (key == null || mappingFunction == null)
1651              throw new NullPointerException();
1652 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1653 <        long r = basis; V v;
1654 <        while ((v = it.advance()) != null)
1655 <            r = reducer.apply(r, transformer.apply((K)it.nextKey, v));
1656 <        return r;
1652 >        int h = spread(key.hashCode());
1653 >        V val = null;
1654 >        int binCount = 0;
1655 >        for (Node<K,V>[] tab = table;;) {
1656 >            Node<K,V> f; int n, i, fh;
1657 >            if (tab == null || (n = tab.length) == 0)
1658 >                tab = initTable();
1659 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1660 >                Node<K,V> r = new ReservationNode<K,V>();
1661 >                synchronized (r) {
1662 >                    if (casTabAt(tab, i, null, r)) {
1663 >                        binCount = 1;
1664 >                        Node<K,V> node = null;
1665 >                        try {
1666 >                            if ((val = mappingFunction.apply(key)) != null)
1667 >                                node = new Node<K,V>(h, key, val, null);
1668 >                        } finally {
1669 >                            setTabAt(tab, i, node);
1670 >                        }
1671 >                    }
1672 >                }
1673 >                if (binCount != 0)
1674 >                    break;
1675 >            }
1676 >            else if ((fh = f.hash) == MOVED)
1677 >                tab = helpTransfer(tab, f);
1678 >            else {
1679 >                boolean added = false;
1680 >                synchronized (f) {
1681 >                    if (tabAt(tab, i) == f) {
1682 >                        if (fh >= 0) {
1683 >                            binCount = 1;
1684 >                            for (Node<K,V> e = f;; ++binCount) {
1685 >                                K ek; V ev;
1686 >                                if (e.hash == h &&
1687 >                                    ((ek = e.key) == key ||
1688 >                                     (ek != null && key.equals(ek)))) {
1689 >                                    val = e.val;
1690 >                                    break;
1691 >                                }
1692 >                                Node<K,V> pred = e;
1693 >                                if ((e = e.next) == null) {
1694 >                                    if ((val = mappingFunction.apply(key)) != null) {
1695 >                                        added = true;
1696 >                                        pred.next = new Node<K,V>(h, key, val, null);
1697 >                                    }
1698 >                                    break;
1699 >                                }
1700 >                            }
1701 >                        }
1702 >                        else if (f instanceof TreeBin) {
1703 >                            binCount = 2;
1704 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1705 >                            TreeNode<K,V> r, p;
1706 >                            if ((r = t.root) != null &&
1707 >                                (p = r.findTreeNode(h, key, null)) != null)
1708 >                                val = p.val;
1709 >                            else if ((val = mappingFunction.apply(key)) != null) {
1710 >                                added = true;
1711 >                                t.putTreeVal(h, key, val);
1712 >                            }
1713 >                        }
1714 >                    }
1715 >                }
1716 >                if (binCount != 0) {
1717 >                    if (binCount >= TREEIFY_THRESHOLD)
1718 >                        treeifyBin(tab, i);
1719 >                    if (!added)
1720 >                        return val;
1721 >                    break;
1722 >                }
1723 >            }
1724 >        }
1725 >        if (val != null)
1726 >            addCount(1L, binCount);
1727 >        return val;
1728      }
1729  
1730      /**
1731 <     * Returns the result of accumulating the given transformation
1732 <     * of all (key, value) pairs using the given reducer to
1733 <     * combine values, and the given basis as an identity value.
1731 >     * If the value for the specified key is present, attempts to
1732 >     * compute a new mapping given the key and its current mapped
1733 >     * value.  The entire method invocation is performed atomically.
1734 >     * Some attempted update operations on this map by other threads
1735 >     * may be blocked while computation is in progress, so the
1736 >     * computation should be short and simple, and must not attempt to
1737 >     * update any other mappings of this map.
1738       *
1739 <     * @param transformer a function returning the transformation
1740 <     * for an element
1741 <     * @param basis the identity (initial default value) for the reduction
1742 <     * @param reducer a commutative associative combining function
1743 <     * @return the result of accumulating the given transformation
1744 <     * of all (key, value) pairs
1739 >     * @param key key with which a value may be associated
1740 >     * @param remappingFunction the function to compute a value
1741 >     * @return the new value associated with the specified key, or null if none
1742 >     * @throws NullPointerException if the specified key or remappingFunction
1743 >     *         is null
1744 >     * @throws IllegalStateException if the computation detectably
1745 >     *         attempts a recursive update to this map that would
1746 >     *         otherwise never complete
1747 >     * @throws RuntimeException or Error if the remappingFunction does so,
1748 >     *         in which case the mapping is unchanged
1749       */
1750 <    @SuppressWarnings("unchecked") public int reduceToIntSequentially
1751 <        (ObjectByObjectToInt<? super K, ? super V> transformer,
3504 <         int basis,
3505 <         IntByIntToInt reducer) {
3506 <        if (transformer == null || reducer == null)
1750 >    public V computeIfPresent(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1751 >        if (key == null || remappingFunction == null)
1752              throw new NullPointerException();
1753 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1754 <        int r = basis; V v;
1755 <        while ((v = it.advance()) != null)
1756 <            r = reducer.apply(r, transformer.apply((K)it.nextKey, v));
1757 <        return r;
1753 >        int h = spread(key.hashCode());
1754 >        V val = null;
1755 >        int delta = 0;
1756 >        int binCount = 0;
1757 >        for (Node<K,V>[] tab = table;;) {
1758 >            Node<K,V> f; int n, i, fh;
1759 >            if (tab == null || (n = tab.length) == 0)
1760 >                tab = initTable();
1761 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1762 >                break;
1763 >            else if ((fh = f.hash) == MOVED)
1764 >                tab = helpTransfer(tab, f);
1765 >            else {
1766 >                synchronized (f) {
1767 >                    if (tabAt(tab, i) == f) {
1768 >                        if (fh >= 0) {
1769 >                            binCount = 1;
1770 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1771 >                                K ek;
1772 >                                if (e.hash == h &&
1773 >                                    ((ek = e.key) == key ||
1774 >                                     (ek != null && key.equals(ek)))) {
1775 >                                    val = remappingFunction.apply(key, e.val);
1776 >                                    if (val != null)
1777 >                                        e.val = val;
1778 >                                    else {
1779 >                                        delta = -1;
1780 >                                        Node<K,V> en = e.next;
1781 >                                        if (pred != null)
1782 >                                            pred.next = en;
1783 >                                        else
1784 >                                            setTabAt(tab, i, en);
1785 >                                    }
1786 >                                    break;
1787 >                                }
1788 >                                pred = e;
1789 >                                if ((e = e.next) == null)
1790 >                                    break;
1791 >                            }
1792 >                        }
1793 >                        else if (f instanceof TreeBin) {
1794 >                            binCount = 2;
1795 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1796 >                            TreeNode<K,V> r, p;
1797 >                            if ((r = t.root) != null &&
1798 >                                (p = r.findTreeNode(h, key, null)) != null) {
1799 >                                val = remappingFunction.apply(key, p.val);
1800 >                                if (val != null)
1801 >                                    p.val = val;
1802 >                                else {
1803 >                                    delta = -1;
1804 >                                    if (t.removeTreeNode(p))
1805 >                                        setTabAt(tab, i, untreeify(t.first));
1806 >                                }
1807 >                            }
1808 >                        }
1809 >                    }
1810 >                }
1811 >                if (binCount != 0)
1812 >                    break;
1813 >            }
1814 >        }
1815 >        if (delta != 0)
1816 >            addCount((long)delta, binCount);
1817 >        return val;
1818      }
1819  
1820      /**
1821 <     * Performs the given action for each key.
1821 >     * Attempts to compute a mapping for the specified key and its
1822 >     * current mapped value (or {@code null} if there is no current
1823 >     * mapping). The entire method invocation is performed atomically.
1824 >     * Some attempted update operations on this map by other threads
1825 >     * may be blocked while computation is in progress, so the
1826 >     * computation should be short and simple, and must not attempt to
1827 >     * update any other mappings of this Map.
1828       *
1829 <     * @param action the action
1829 >     * @param key key with which the specified value is to be associated
1830 >     * @param remappingFunction the function to compute a value
1831 >     * @return the new value associated with the specified key, or null if none
1832 >     * @throws NullPointerException if the specified key or remappingFunction
1833 >     *         is null
1834 >     * @throws IllegalStateException if the computation detectably
1835 >     *         attempts a recursive update to this map that would
1836 >     *         otherwise never complete
1837 >     * @throws RuntimeException or Error if the remappingFunction does so,
1838 >     *         in which case the mapping is unchanged
1839       */
1840 <    @SuppressWarnings("unchecked") public void forEachKeySequentially
1841 <        (Action<K> action) {
1842 <        if (action == null) throw new NullPointerException();
1843 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1844 <        while (it.advance() != null)
1845 <            action.apply((K)it.nextKey);
1840 >    public V compute(K key,
1841 >                     BiFun<? super K, ? super V, ? extends V> remappingFunction) {
1842 >        if (key == null || remappingFunction == null)
1843 >            throw new NullPointerException();
1844 >        int h = spread(key.hashCode());
1845 >        V val = null;
1846 >        int delta = 0;
1847 >        int binCount = 0;
1848 >        for (Node<K,V>[] tab = table;;) {
1849 >            Node<K,V> f; int n, i, fh;
1850 >            if (tab == null || (n = tab.length) == 0)
1851 >                tab = initTable();
1852 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1853 >                Node<K,V> r = new ReservationNode<K,V>();
1854 >                synchronized (r) {
1855 >                    if (casTabAt(tab, i, null, r)) {
1856 >                        binCount = 1;
1857 >                        Node<K,V> node = null;
1858 >                        try {
1859 >                            if ((val = remappingFunction.apply(key, null)) != null) {
1860 >                                delta = 1;
1861 >                                node = new Node<K,V>(h, key, val, null);
1862 >                            }
1863 >                        } finally {
1864 >                            setTabAt(tab, i, node);
1865 >                        }
1866 >                    }
1867 >                }
1868 >                if (binCount != 0)
1869 >                    break;
1870 >            }
1871 >            else if ((fh = f.hash) == MOVED)
1872 >                tab = helpTransfer(tab, f);
1873 >            else {
1874 >                synchronized (f) {
1875 >                    if (tabAt(tab, i) == f) {
1876 >                        if (fh >= 0) {
1877 >                            binCount = 1;
1878 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1879 >                                K ek;
1880 >                                if (e.hash == h &&
1881 >                                    ((ek = e.key) == key ||
1882 >                                     (ek != null && key.equals(ek)))) {
1883 >                                    val = remappingFunction.apply(key, e.val);
1884 >                                    if (val != null)
1885 >                                        e.val = val;
1886 >                                    else {
1887 >                                        delta = -1;
1888 >                                        Node<K,V> en = e.next;
1889 >                                        if (pred != null)
1890 >                                            pred.next = en;
1891 >                                        else
1892 >                                            setTabAt(tab, i, en);
1893 >                                    }
1894 >                                    break;
1895 >                                }
1896 >                                pred = e;
1897 >                                if ((e = e.next) == null) {
1898 >                                    val = remappingFunction.apply(key, null);
1899 >                                    if (val != null) {
1900 >                                        delta = 1;
1901 >                                        pred.next =
1902 >                                            new Node<K,V>(h, key, val, null);
1903 >                                    }
1904 >                                    break;
1905 >                                }
1906 >                            }
1907 >                        }
1908 >                        else if (f instanceof TreeBin) {
1909 >                            binCount = 1;
1910 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
1911 >                            TreeNode<K,V> r, p;
1912 >                            if ((r = t.root) != null)
1913 >                                p = r.findTreeNode(h, key, null);
1914 >                            else
1915 >                                p = null;
1916 >                            V pv = (p == null) ? null : p.val;
1917 >                            val = remappingFunction.apply(key, pv);
1918 >                            if (val != null) {
1919 >                                if (p != null)
1920 >                                    p.val = val;
1921 >                                else {
1922 >                                    delta = 1;
1923 >                                    t.putTreeVal(h, key, val);
1924 >                                }
1925 >                            }
1926 >                            else if (p != null) {
1927 >                                delta = -1;
1928 >                                if (t.removeTreeNode(p))
1929 >                                    setTabAt(tab, i, untreeify(t.first));
1930 >                            }
1931 >                        }
1932 >                    }
1933 >                }
1934 >                if (binCount != 0) {
1935 >                    if (binCount >= TREEIFY_THRESHOLD)
1936 >                        treeifyBin(tab, i);
1937 >                    break;
1938 >                }
1939 >            }
1940 >        }
1941 >        if (delta != 0)
1942 >            addCount((long)delta, binCount);
1943 >        return val;
1944      }
1945  
1946      /**
1947 <     * Performs the given action for each non-null transformation
1948 <     * of each key.
1947 >     * If the specified key is not already associated with a
1948 >     * (non-null) value, associates it with the given value.
1949 >     * Otherwise, replaces the value with the results of the given
1950 >     * remapping function, or removes if {@code null}. The entire
1951 >     * method invocation is performed atomically.  Some attempted
1952 >     * update operations on this map by other threads may be blocked
1953 >     * while computation is in progress, so the computation should be
1954 >     * short and simple, and must not attempt to update any other
1955 >     * mappings of this Map.
1956       *
1957 <     * @param transformer a function returning the transformation
1958 <     * for an element, or null if there is no transformation (in
1959 <     * which case the action is not applied).
1960 <     * @param action the action
1957 >     * @param key key with which the specified value is to be associated
1958 >     * @param value the value to use if absent
1959 >     * @param remappingFunction the function to recompute a value if present
1960 >     * @return the new value associated with the specified key, or null if none
1961 >     * @throws NullPointerException if the specified key or the
1962 >     *         remappingFunction is null
1963 >     * @throws RuntimeException or Error if the remappingFunction does so,
1964 >     *         in which case the mapping is unchanged
1965       */
1966 <    @SuppressWarnings("unchecked") public <U> void forEachKeySequentially
1967 <        (Fun<? super K, ? extends U> transformer,
3539 <         Action<U> action) {
3540 <        if (transformer == null || action == null)
1966 >    public V merge(K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
1967 >        if (key == null || value == null || remappingFunction == null)
1968              throw new NullPointerException();
1969 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
1970 <        U u;
1971 <        while (it.advance() != null) {
1972 <            if ((u = transformer.apply((K)it.nextKey)) != null)
1973 <                action.apply(u);
1969 >        int h = spread(key.hashCode());
1970 >        V val = null;
1971 >        int delta = 0;
1972 >        int binCount = 0;
1973 >        for (Node<K,V>[] tab = table;;) {
1974 >            Node<K,V> f; int n, i, fh;
1975 >            if (tab == null || (n = tab.length) == 0)
1976 >                tab = initTable();
1977 >            else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1978 >                if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1979 >                    delta = 1;
1980 >                    val = value;
1981 >                    break;
1982 >                }
1983 >            }
1984 >            else if ((fh = f.hash) == MOVED)
1985 >                tab = helpTransfer(tab, f);
1986 >            else {
1987 >                synchronized (f) {
1988 >                    if (tabAt(tab, i) == f) {
1989 >                        if (fh >= 0) {
1990 >                            binCount = 1;
1991 >                            for (Node<K,V> e = f, pred = null;; ++binCount) {
1992 >                                K ek;
1993 >                                if (e.hash == h &&
1994 >                                    ((ek = e.key) == key ||
1995 >                                     (ek != null && key.equals(ek)))) {
1996 >                                    val = remappingFunction.apply(e.val, value);
1997 >                                    if (val != null)
1998 >                                        e.val = val;
1999 >                                    else {
2000 >                                        delta = -1;
2001 >                                        Node<K,V> en = e.next;
2002 >                                        if (pred != null)
2003 >                                            pred.next = en;
2004 >                                        else
2005 >                                            setTabAt(tab, i, en);
2006 >                                    }
2007 >                                    break;
2008 >                                }
2009 >                                pred = e;
2010 >                                if ((e = e.next) == null) {
2011 >                                    delta = 1;
2012 >                                    val = value;
2013 >                                    pred.next =
2014 >                                        new Node<K,V>(h, key, val, null);
2015 >                                    break;
2016 >                                }
2017 >                            }
2018 >                        }
2019 >                        else if (f instanceof TreeBin) {
2020 >                            binCount = 2;
2021 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
2022 >                            TreeNode<K,V> r = t.root;
2023 >                            TreeNode<K,V> p = (r == null) ? null :
2024 >                                r.findTreeNode(h, key, null);
2025 >                            val = (p == null) ? value :
2026 >                                remappingFunction.apply(p.val, value);
2027 >                            if (val != null) {
2028 >                                if (p != null)
2029 >                                    p.val = val;
2030 >                                else {
2031 >                                    delta = 1;
2032 >                                    t.putTreeVal(h, key, val);
2033 >                                }
2034 >                            }
2035 >                            else if (p != null) {
2036 >                                delta = -1;
2037 >                                if (t.removeTreeNode(p))
2038 >                                    setTabAt(tab, i, untreeify(t.first));
2039 >                            }
2040 >                        }
2041 >                    }
2042 >                }
2043 >                if (binCount != 0) {
2044 >                    if (binCount >= TREEIFY_THRESHOLD)
2045 >                        treeifyBin(tab, i);
2046 >                    break;
2047 >                }
2048 >            }
2049          }
2050 <        ForkJoinTasks.forEachKey
2051 <            (this, transformer, action).invoke();
2050 >        if (delta != 0)
2051 >            addCount((long)delta, binCount);
2052 >        return val;
2053      }
2054  
2055 +    // Hashtable legacy methods
2056 +
2057      /**
2058 <     * Returns a non-null result from applying the given search
2059 <     * function on each key, or null if none.
2058 >     * Legacy method testing if some key maps into the specified value
2059 >     * in this table.  This method is identical in functionality to
2060 >     * {@link #containsValue(Object)}, and exists solely to ensure
2061 >     * full compatibility with class {@link java.util.Hashtable},
2062 >     * which supported this method prior to introduction of the
2063 >     * Java Collections framework.
2064       *
2065 <     * @param searchFunction a function returning a non-null
2066 <     * result on success, else null
2067 <     * @return a non-null result from applying the given search
2068 <     * function on each key, or null if none
2065 >     * @param  value a value to search for
2066 >     * @return {@code true} if and only if some key maps to the
2067 >     *         {@code value} argument in this table as
2068 >     *         determined by the {@code equals} method;
2069 >     *         {@code false} otherwise
2070 >     * @throws NullPointerException if the specified value is null
2071       */
2072 <    @SuppressWarnings("unchecked") public <U> U searchKeysSequentially
2073 <        (Fun<? super K, ? extends U> searchFunction) {
3563 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3564 <        U u;
3565 <        while (it.advance() != null) {
3566 <            if ((u = searchFunction.apply((K)it.nextKey)) != null)
3567 <                return u;
3568 <        }
3569 <        return null;
2072 >    @Deprecated public boolean contains(Object value) {
2073 >        return containsValue(value);
2074      }
2075  
2076      /**
2077 <     * Returns the result of accumulating all keys using the given
3574 <     * reducer to combine values, or null if none.
2077 >     * Returns an enumeration of the keys in this table.
2078       *
2079 <     * @param reducer a commutative associative combining function
2080 <     * @return the result of accumulating all keys using the given
3578 <     * reducer to combine values, or null if none
2079 >     * @return an enumeration of the keys in this table
2080 >     * @see #keySet()
2081       */
2082 <    @SuppressWarnings("unchecked") public K reduceKeysSequentially
2083 <        (BiFun<? super K, ? super K, ? extends K> reducer) {
2084 <        if (reducer == null) throw new NullPointerException();
2085 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3584 <        K r = null;
3585 <        while (it.advance() != null) {
3586 <            K u = (K)it.nextKey;
3587 <            r = (r == null) ? u : reducer.apply(r, u);
3588 <        }
3589 <        return r;
2082 >    public Enumeration<K> keys() {
2083 >        Node<K,V>[] t;
2084 >        int f = (t = table) == null ? 0 : t.length;
2085 >        return new KeyIterator<K,V>(t, f, 0, f, this);
2086      }
2087  
2088      /**
2089 <     * Returns the result of accumulating the given transformation
3594 <     * of all keys using the given reducer to combine values, or
3595 <     * null if none.
2089 >     * Returns an enumeration of the values in this table.
2090       *
2091 <     * @param transformer a function returning the transformation
2092 <     * for an element, or null if there is no transformation (in
3599 <     * which case it is not combined).
3600 <     * @param reducer a commutative associative combining function
3601 <     * @return the result of accumulating the given transformation
3602 <     * of all keys
2091 >     * @return an enumeration of the values in this table
2092 >     * @see #values()
2093       */
2094 <    @SuppressWarnings("unchecked") public <U> U reduceKeysSequentially
2095 <        (Fun<? super K, ? extends U> transformer,
2096 <         BiFun<? super U, ? super U, ? extends U> reducer) {
2097 <        if (transformer == null || reducer == null)
3608 <            throw new NullPointerException();
3609 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3610 <        U r = null, u;
3611 <        while (it.advance() != null) {
3612 <            if ((u = transformer.apply((K)it.nextKey)) != null)
3613 <                r = (r == null) ? u : reducer.apply(r, u);
3614 <        }
3615 <        return r;
2094 >    public Enumeration<V> elements() {
2095 >        Node<K,V>[] t;
2096 >        int f = (t = table) == null ? 0 : t.length;
2097 >        return new ValueIterator<K,V>(t, f, 0, f, this);
2098      }
2099  
2100 +    // ConcurrentHashMapV8-only methods
2101 +
2102      /**
2103 <     * Returns the result of accumulating the given transformation
2104 <     * of all keys using the given reducer to combine values, and
2105 <     * the given basis as an identity value.
2103 >     * Returns the number of mappings. This method should be used
2104 >     * instead of {@link #size} because a ConcurrentHashMapV8 may
2105 >     * contain more mappings than can be represented as an int. The
2106 >     * value returned is an estimate; the actual count may differ if
2107 >     * there are concurrent insertions or removals.
2108       *
2109 <     * @param transformer a function returning the transformation
2110 <     * for an element
3625 <     * @param basis the identity (initial default value) for the reduction
3626 <     * @param reducer a commutative associative combining function
3627 <     * @return  the result of accumulating the given transformation
3628 <     * of all keys
2109 >     * @return the number of mappings
2110 >     * @since 1.8
2111       */
2112 <    @SuppressWarnings("unchecked") public double reduceKeysToDoubleSequentially
2113 <        (ObjectToDouble<? super K> transformer,
2114 <         double basis,
3633 <         DoubleByDoubleToDouble reducer) {
3634 <        if (transformer == null || reducer == null)
3635 <            throw new NullPointerException();
3636 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3637 <        double r = basis;
3638 <        while (it.advance() != null)
3639 <            r = reducer.apply(r, transformer.apply((K)it.nextKey));
3640 <        return r;
2112 >    public long mappingCount() {
2113 >        long n = sumCount();
2114 >        return (n < 0L) ? 0L : n; // ignore transient negative values
2115      }
2116  
2117      /**
2118 <     * Returns the result of accumulating the given transformation
2119 <     * of all keys using the given reducer to combine values, and
3646 <     * the given basis as an identity value.
2118 >     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2119 >     * from the given type to {@code Boolean.TRUE}.
2120       *
2121 <     * @param transformer a function returning the transformation
2122 <     * for an element
3650 <     * @param basis the identity (initial default value) for the reduction
3651 <     * @param reducer a commutative associative combining function
3652 <     * @return the result of accumulating the given transformation
3653 <     * of all keys
2121 >     * @return the new set
2122 >     * @since 1.8
2123       */
2124 <    @SuppressWarnings("unchecked") public long reduceKeysToLongSequentially
2125 <        (ObjectToLong<? super K> transformer,
2126 <         long basis,
3658 <         LongByLongToLong reducer) {
3659 <        if (transformer == null || reducer == null)
3660 <            throw new NullPointerException();
3661 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3662 <        long r = basis;
3663 <        while (it.advance() != null)
3664 <            r = reducer.apply(r, transformer.apply((K)it.nextKey));
3665 <        return r;
2124 >    public static <K> KeySetView<K,Boolean> newKeySet() {
2125 >        return new KeySetView<K,Boolean>
2126 >            (new ConcurrentHashMapV8<K,Boolean>(), Boolean.TRUE);
2127      }
2128  
2129      /**
2130 <     * Returns the result of accumulating the given transformation
2131 <     * of all keys using the given reducer to combine values, and
3671 <     * the given basis as an identity value.
2130 >     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
2131 >     * from the given type to {@code Boolean.TRUE}.
2132       *
2133 <     * @param transformer a function returning the transformation
2134 <     * for an element
2135 <     * @param basis the identity (initial default value) for the reduction
2136 <     * @param reducer a commutative associative combining function
2137 <     * @return the result of accumulating the given transformation
2138 <     * of all keys
2133 >     * @param initialCapacity The implementation performs internal
2134 >     * sizing to accommodate this many elements.
2135 >     * @return the new set
2136 >     * @throws IllegalArgumentException if the initial capacity of
2137 >     * elements is negative
2138 >     * @since 1.8
2139       */
2140 <    @SuppressWarnings("unchecked") public int reduceKeysToIntSequentially
2141 <        (ObjectToInt<? super K> transformer,
2142 <         int basis,
3683 <         IntByIntToInt reducer) {
3684 <        if (transformer == null || reducer == null)
3685 <            throw new NullPointerException();
3686 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3687 <        int r = basis;
3688 <        while (it.advance() != null)
3689 <            r = reducer.apply(r, transformer.apply((K)it.nextKey));
3690 <        return r;
2140 >    public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2141 >        return new KeySetView<K,Boolean>
2142 >            (new ConcurrentHashMapV8<K,Boolean>(initialCapacity), Boolean.TRUE);
2143      }
2144  
2145      /**
2146 <     * Performs the given action for each value.
2146 >     * Returns a {@link Set} view of the keys in this map, using the
2147 >     * given common mapped value for any additions (i.e., {@link
2148 >     * Collection#add} and {@link Collection#addAll(Collection)}).
2149 >     * This is of course only appropriate if it is acceptable to use
2150 >     * the same value for all additions from this view.
2151       *
2152 <     * @param action the action
2152 >     * @param mappedValue the mapped value to use for any additions
2153 >     * @return the set view
2154 >     * @throws NullPointerException if the mappedValue is null
2155       */
2156 <    public void forEachValueSequentially(Action<V> action) {
2157 <        if (action == null) throw new NullPointerException();
2158 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2159 <        V v;
3702 <        while ((v = it.advance()) != null)
3703 <            action.apply(v);
2156 >    public KeySetView<K,V> keySet(V mappedValue) {
2157 >        if (mappedValue == null)
2158 >            throw new NullPointerException();
2159 >        return new KeySetView<K,V>(this, mappedValue);
2160      }
2161  
2162 +    /* ---------------- Special Nodes -------------- */
2163 +
2164      /**
2165 <     * Performs the given action for each non-null transformation
3708 <     * of each value.
3709 <     *
3710 <     * @param transformer a function returning the transformation
3711 <     * for an element, or null if there is no transformation (in
3712 <     * which case the action is not applied).
2165 >     * A node inserted at head of bins during transfer operations.
2166       */
2167 <    public <U> void forEachValueSequentially
2168 <        (Fun<? super V, ? extends U> transformer,
2169 <         Action<U> action) {
2170 <        if (transformer == null || action == null)
2171 <            throw new NullPointerException();
2172 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2173 <        V v; U u;
2174 <        while ((v = it.advance()) != null) {
2175 <            if ((u = transformer.apply(v)) != null)
2176 <                action.apply(u);
2167 >    static final class ForwardingNode<K,V> extends Node<K,V> {
2168 >        final Node<K,V>[] nextTable;
2169 >        ForwardingNode(Node<K,V>[] tab) {
2170 >            super(MOVED, null, null, null);
2171 >            this.nextTable = tab;
2172 >        }
2173 >
2174 >        Node<K,V> find(int h, Object k) {
2175 >            // loop to avoid arbitrarily deep recursion on forwarding nodes
2176 >            outer: for (Node<K,V>[] tab = nextTable;;) {
2177 >                Node<K,V> e; int n;
2178 >                if (k == null || tab == null || (n = tab.length) == 0 ||
2179 >                    (e = tabAt(tab, (n - 1) & h)) == null)
2180 >                    return null;
2181 >                for (;;) {
2182 >                    int eh; K ek;
2183 >                    if ((eh = e.hash) == h &&
2184 >                        ((ek = e.key) == k || (ek != null && k.equals(ek))))
2185 >                        return e;
2186 >                    if (eh < 0) {
2187 >                        if (e instanceof ForwardingNode) {
2188 >                            tab = ((ForwardingNode<K,V>)e).nextTable;
2189 >                            continue outer;
2190 >                        }
2191 >                        else
2192 >                            return e.find(h, k);
2193 >                    }
2194 >                    if ((e = e.next) == null)
2195 >                        return null;
2196 >                }
2197 >            }
2198          }
2199      }
2200  
2201      /**
2202 <     * Returns a non-null result from applying the given search
3729 <     * function on each value, or null if none.
3730 <     *
3731 <     * @param searchFunction a function returning a non-null
3732 <     * result on success, else null
3733 <     * @return a non-null result from applying the given search
3734 <     * function on each value, or null if none
2202 >     * A place-holder node used in computeIfAbsent and compute
2203       */
2204 <    public <U> U searchValuesSequentially
2205 <        (Fun<? super V, ? extends U> searchFunction) {
2206 <        if (searchFunction == null) throw new NullPointerException();
2207 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2208 <        V v; U u;
2209 <        while ((v = it.advance()) != null) {
2210 <            if ((u = searchFunction.apply(v)) != null)
3743 <                return u;
2204 >    static final class ReservationNode<K,V> extends Node<K,V> {
2205 >        ReservationNode() {
2206 >            super(RESERVED, null, null, null);
2207 >        }
2208 >
2209 >        Node<K,V> find(int h, Object k) {
2210 >            return null;
2211          }
3745        return null;
2212      }
2213  
2214 +    /* ---------------- Table Initialization and Resizing -------------- */
2215 +
2216      /**
2217 <     * Returns the result of accumulating all values using the
2218 <     * given reducer to combine values, or null if none.
3751 <     *
3752 <     * @param reducer a commutative associative combining function
3753 <     * @return  the result of accumulating all values
2217 >     * Returns the stamp bits for resizing a table of size n.
2218 >     * Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2219       */
2220 <    public V reduceValuesSequentially
2221 <        (BiFun<? super V, ? super V, ? extends V> reducer) {
3757 <        if (reducer == null) throw new NullPointerException();
3758 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3759 <        V r = null; V v;
3760 <        while ((v = it.advance()) != null)
3761 <            r = (r == null) ? v : reducer.apply(r, v);
3762 <        return r;
2220 >    static final int resizeStamp(int n) {
2221 >        return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2222      }
2223  
2224      /**
2225 <     * Returns the result of accumulating the given transformation
3767 <     * of all values using the given reducer to combine values, or
3768 <     * null if none.
3769 <     *
3770 <     * @param transformer a function returning the transformation
3771 <     * for an element, or null if there is no transformation (in
3772 <     * which case it is not combined).
3773 <     * @param reducer a commutative associative combining function
3774 <     * @return the result of accumulating the given transformation
3775 <     * of all values
2225 >     * Initializes table, using the size recorded in sizeCtl.
2226       */
2227 <    public <U> U reduceValuesSequentially
2228 <        (Fun<? super V, ? extends U> transformer,
2229 <         BiFun<? super U, ? super U, ? extends U> reducer) {
2230 <        if (transformer == null || reducer == null)
2231 <            throw new NullPointerException();
2232 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2233 <        U r = null, u; V v;
2234 <        while ((v = it.advance()) != null) {
2235 <            if ((u = transformer.apply(v)) != null)
2236 <                r = (r == null) ? u : reducer.apply(r, u);
2227 >    private final Node<K,V>[] initTable() {
2228 >        Node<K,V>[] tab; int sc;
2229 >        while ((tab = table) == null || tab.length == 0) {
2230 >            if ((sc = sizeCtl) < 0)
2231 >                Thread.yield(); // lost initialization race; just spin
2232 >            else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2233 >                try {
2234 >                    if ((tab = table) == null || tab.length == 0) {
2235 >                        int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2236 >                        @SuppressWarnings("unchecked")
2237 >                        Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2238 >                        table = tab = nt;
2239 >                        sc = n - (n >>> 2);
2240 >                    }
2241 >                } finally {
2242 >                    sizeCtl = sc;
2243 >                }
2244 >                break;
2245 >            }
2246          }
2247 <        return r;
2247 >        return tab;
2248      }
2249  
2250      /**
2251 <     * Returns the result of accumulating the given transformation
2252 <     * of all values using the given reducer to combine values,
2253 <     * and the given basis as an identity value.
2251 >     * Adds to count, and if table is too small and not already
2252 >     * resizing, initiates transfer. If already resizing, helps
2253 >     * perform transfer if work is available.  Rechecks occupancy
2254 >     * after a transfer to see if another resize is already needed
2255 >     * because resizings are lagging additions.
2256       *
2257 <     * @param transformer a function returning the transformation
2258 <     * for an element
3798 <     * @param basis the identity (initial default value) for the reduction
3799 <     * @param reducer a commutative associative combining function
3800 <     * @return the result of accumulating the given transformation
3801 <     * of all values
2257 >     * @param x the count to add
2258 >     * @param check if <0, don't check resize, if <= 1 only check if uncontended
2259       */
2260 <    public double reduceValuesToDoubleSequentially
2261 <        (ObjectToDouble<? super V> transformer,
2262 <         double basis,
2263 <         DoubleByDoubleToDouble reducer) {
2264 <        if (transformer == null || reducer == null)
2265 <            throw new NullPointerException();
2266 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2267 <        double r = basis; V v;
2268 <        while ((v = it.advance()) != null)
2269 <            r = reducer.apply(r, transformer.apply(v));
2270 <        return r;
2260 >    private final void addCount(long x, int check) {
2261 >        CounterCell[] as; long b, s;
2262 >        if ((as = counterCells) != null ||
2263 >            !U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2264 >            CounterHashCode hc; CounterCell a; long v; int m;
2265 >            boolean uncontended = true;
2266 >            if ((hc = threadCounterHashCode.get()) == null ||
2267 >                as == null || (m = as.length - 1) < 0 ||
2268 >                (a = as[m & hc.code]) == null ||
2269 >                !(uncontended =
2270 >                  U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2271 >                fullAddCount(x, hc, uncontended);
2272 >                return;
2273 >            }
2274 >            if (check <= 1)
2275 >                return;
2276 >            s = sumCount();
2277 >        }
2278 >        if (check >= 0) {
2279 >            Node<K,V>[] tab, nt; int n, sc;
2280 >            while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2281 >                   (n = tab.length) < MAXIMUM_CAPACITY) {
2282 >                int rs = resizeStamp(n);
2283 >                if (sc < 0) {
2284 >                    if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2285 >                        sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2286 >                        transferIndex <= 0)
2287 >                        break;
2288 >                    if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2289 >                        transfer(tab, nt);
2290 >                }
2291 >                else if (U.compareAndSwapInt(this, SIZECTL, sc,
2292 >                                             (rs << RESIZE_STAMP_SHIFT) + 2))
2293 >                    transfer(tab, null);
2294 >                s = sumCount();
2295 >            }
2296 >        }
2297      }
2298  
2299      /**
2300 <     * Returns the result of accumulating the given transformation
3818 <     * of all values using the given reducer to combine values,
3819 <     * and the given basis as an identity value.
3820 <     *
3821 <     * @param transformer a function returning the transformation
3822 <     * for an element
3823 <     * @param basis the identity (initial default value) for the reduction
3824 <     * @param reducer a commutative associative combining function
3825 <     * @return the result of accumulating the given transformation
3826 <     * of all values
2300 >     * Helps transfer if a resize is in progress.
2301       */
2302 <    public long reduceValuesToLongSequentially
2303 <        (ObjectToLong<? super V> transformer,
2304 <         long basis,
2305 <         LongByLongToLong reducer) {
2306 <        if (transformer == null || reducer == null)
2307 <            throw new NullPointerException();
2308 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2309 <        long r = basis; V v;
2310 <        while ((v = it.advance()) != null)
2311 <            r = reducer.apply(r, transformer.apply(v));
2312 <        return r;
2302 >    final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2303 >        Node<K,V>[] nextTab; int sc;
2304 >        if (tab != null && (f instanceof ForwardingNode) &&
2305 >            (nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2306 >            int rs = resizeStamp(tab.length);
2307 >            while (nextTab == nextTable && table == tab &&
2308 >                   (sc = sizeCtl) < 0) {
2309 >                if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2310 >                    sc == rs + MAX_RESIZERS || transferIndex <= 0)
2311 >                    break;
2312 >                if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2313 >                    transfer(tab, nextTab);
2314 >                    break;
2315 >                }
2316 >            }
2317 >            return nextTab;
2318 >        }
2319 >        return table;
2320      }
2321  
2322      /**
2323 <     * Returns the result of accumulating the given transformation
3843 <     * of all values using the given reducer to combine values,
3844 <     * and the given basis as an identity value.
2323 >     * Tries to presize table to accommodate the given number of elements.
2324       *
2325 <     * @param transformer a function returning the transformation
3847 <     * for an element
3848 <     * @param basis the identity (initial default value) for the reduction
3849 <     * @param reducer a commutative associative combining function
3850 <     * @return the result of accumulating the given transformation
3851 <     * of all values
2325 >     * @param size number of elements (doesn't need to be perfectly accurate)
2326       */
2327 <    public int reduceValuesToIntSequentially
2328 <        (ObjectToInt<? super V> transformer,
2329 <         int basis,
2330 <         IntByIntToInt reducer) {
2331 <        if (transformer == null || reducer == null)
2332 <            throw new NullPointerException();
2333 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2334 <        int r = basis; V v;
2335 <        while ((v = it.advance()) != null)
2336 <            r = reducer.apply(r, transformer.apply(v));
2337 <        return r;
2327 >    private final void tryPresize(int size) {
2328 >        int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2329 >            tableSizeFor(size + (size >>> 1) + 1);
2330 >        int sc;
2331 >        while ((sc = sizeCtl) >= 0) {
2332 >            Node<K,V>[] tab = table; int n;
2333 >            if (tab == null || (n = tab.length) == 0) {
2334 >                n = (sc > c) ? sc : c;
2335 >                if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2336 >                    try {
2337 >                        if (table == tab) {
2338 >                            @SuppressWarnings("unchecked")
2339 >                            Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2340 >                            table = nt;
2341 >                            sc = n - (n >>> 2);
2342 >                        }
2343 >                    } finally {
2344 >                        sizeCtl = sc;
2345 >                    }
2346 >                }
2347 >            }
2348 >            else if (c <= sc || n >= MAXIMUM_CAPACITY)
2349 >                break;
2350 >            else if (tab == table) {
2351 >                int rs = resizeStamp(n);
2352 >                if (sc < 0) {
2353 >                    Node<K,V>[] nt;
2354 >                    if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2355 >                        sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2356 >                        transferIndex <= 0)
2357 >                        break;
2358 >                    if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2359 >                        transfer(tab, nt);
2360 >                }
2361 >                else if (U.compareAndSwapInt(this, SIZECTL, sc,
2362 >                                             (rs << RESIZE_STAMP_SHIFT) + 2))
2363 >                    transfer(tab, null);
2364 >            }
2365 >        }
2366      }
2367  
2368      /**
2369 <     * Performs the given action for each entry.
2370 <     *
3869 <     * @param action the action
2369 >     * Moves and/or copies the nodes in each bin to new table. See
2370 >     * above for explanation.
2371       */
2372 <    @SuppressWarnings("unchecked") public void forEachEntrySequentially
2373 <        (Action<Map.Entry<K,V>> action) {
2374 <        if (action == null) throw new NullPointerException();
2375 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2376 <        V v;
2377 <        while ((v = it.advance()) != null)
2378 <            action.apply(entryFor((K)it.nextKey, v));
2372 >    private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2373 >        int n = tab.length, stride;
2374 >        if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2375 >            stride = MIN_TRANSFER_STRIDE; // subdivide range
2376 >        if (nextTab == null) {            // initiating
2377 >            try {
2378 >                @SuppressWarnings("unchecked")
2379 >                Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2380 >                nextTab = nt;
2381 >            } catch (Throwable ex) {      // try to cope with OOME
2382 >                sizeCtl = Integer.MAX_VALUE;
2383 >                return;
2384 >            }
2385 >            nextTable = nextTab;
2386 >            transferIndex = n;
2387 >        }
2388 >        int nextn = nextTab.length;
2389 >        ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2390 >        boolean advance = true;
2391 >        boolean finishing = false; // to ensure sweep before committing nextTab
2392 >        for (int i = 0, bound = 0;;) {
2393 >            Node<K,V> f; int fh;
2394 >            while (advance) {
2395 >                int nextIndex, nextBound;
2396 >                if (--i >= bound || finishing)
2397 >                    advance = false;
2398 >                else if ((nextIndex = transferIndex) <= 0) {
2399 >                    i = -1;
2400 >                    advance = false;
2401 >                }
2402 >                else if (U.compareAndSwapInt
2403 >                         (this, TRANSFERINDEX, nextIndex,
2404 >                          nextBound = (nextIndex > stride ?
2405 >                                       nextIndex - stride : 0))) {
2406 >                    bound = nextBound;
2407 >                    i = nextIndex - 1;
2408 >                    advance = false;
2409 >                }
2410 >            }
2411 >            if (i < 0 || i >= n || i + n >= nextn) {
2412 >                int sc;
2413 >                if (finishing) {
2414 >                    nextTable = null;
2415 >                    table = nextTab;
2416 >                    sizeCtl = (n << 1) - (n >>> 1);
2417 >                    return;
2418 >                }
2419 >                if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2420 >                    if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2421 >                        return;
2422 >                    finishing = advance = true;
2423 >                    i = n; // recheck before commit
2424 >                }
2425 >            }
2426 >            else if ((f = tabAt(tab, i)) == null)
2427 >                advance = casTabAt(tab, i, null, fwd);
2428 >            else if ((fh = f.hash) == MOVED)
2429 >                advance = true; // already processed
2430 >            else {
2431 >                synchronized (f) {
2432 >                    if (tabAt(tab, i) == f) {
2433 >                        Node<K,V> ln, hn;
2434 >                        if (fh >= 0) {
2435 >                            int runBit = fh & n;
2436 >                            Node<K,V> lastRun = f;
2437 >                            for (Node<K,V> p = f.next; p != null; p = p.next) {
2438 >                                int b = p.hash & n;
2439 >                                if (b != runBit) {
2440 >                                    runBit = b;
2441 >                                    lastRun = p;
2442 >                                }
2443 >                            }
2444 >                            if (runBit == 0) {
2445 >                                ln = lastRun;
2446 >                                hn = null;
2447 >                            }
2448 >                            else {
2449 >                                hn = lastRun;
2450 >                                ln = null;
2451 >                            }
2452 >                            for (Node<K,V> p = f; p != lastRun; p = p.next) {
2453 >                                int ph = p.hash; K pk = p.key; V pv = p.val;
2454 >                                if ((ph & n) == 0)
2455 >                                    ln = new Node<K,V>(ph, pk, pv, ln);
2456 >                                else
2457 >                                    hn = new Node<K,V>(ph, pk, pv, hn);
2458 >                            }
2459 >                            setTabAt(nextTab, i, ln);
2460 >                            setTabAt(nextTab, i + n, hn);
2461 >                            setTabAt(tab, i, fwd);
2462 >                            advance = true;
2463 >                        }
2464 >                        else if (f instanceof TreeBin) {
2465 >                            TreeBin<K,V> t = (TreeBin<K,V>)f;
2466 >                            TreeNode<K,V> lo = null, loTail = null;
2467 >                            TreeNode<K,V> hi = null, hiTail = null;
2468 >                            int lc = 0, hc = 0;
2469 >                            for (Node<K,V> e = t.first; e != null; e = e.next) {
2470 >                                int h = e.hash;
2471 >                                TreeNode<K,V> p = new TreeNode<K,V>
2472 >                                    (h, e.key, e.val, null, null);
2473 >                                if ((h & n) == 0) {
2474 >                                    if ((p.prev = loTail) == null)
2475 >                                        lo = p;
2476 >                                    else
2477 >                                        loTail.next = p;
2478 >                                    loTail = p;
2479 >                                    ++lc;
2480 >                                }
2481 >                                else {
2482 >                                    if ((p.prev = hiTail) == null)
2483 >                                        hi = p;
2484 >                                    else
2485 >                                        hiTail.next = p;
2486 >                                    hiTail = p;
2487 >                                    ++hc;
2488 >                                }
2489 >                            }
2490 >                            ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2491 >                                (hc != 0) ? new TreeBin<K,V>(lo) : t;
2492 >                            hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2493 >                                (lc != 0) ? new TreeBin<K,V>(hi) : t;
2494 >                            setTabAt(nextTab, i, ln);
2495 >                            setTabAt(nextTab, i + n, hn);
2496 >                            setTabAt(tab, i, fwd);
2497 >                            advance = true;
2498 >                        }
2499 >                    }
2500 >                }
2501 >            }
2502 >        }
2503      }
2504  
2505 +    /* ---------------- Conversion from/to TreeBins -------------- */
2506 +
2507      /**
2508 <     * Performs the given action for each non-null transformation
2509 <     * of each entry.
3883 <     *
3884 <     * @param transformer a function returning the transformation
3885 <     * for an element, or null if there is no transformation (in
3886 <     * which case the action is not applied).
3887 <     * @param action the action
2508 >     * Replaces all linked nodes in bin at given index unless table is
2509 >     * too small, in which case resizes instead.
2510       */
2511 <    @SuppressWarnings("unchecked") public <U> void forEachEntrySequentially
2512 <        (Fun<Map.Entry<K,V>, ? extends U> transformer,
2513 <         Action<U> action) {
2514 <        if (transformer == null || action == null)
2515 <            throw new NullPointerException();
2516 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2517 <        V v; U u;
2518 <        while ((v = it.advance()) != null) {
2519 <            if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null)
2520 <                action.apply(u);
2511 >    private final void treeifyBin(Node<K,V>[] tab, int index) {
2512 >        Node<K,V> b; int n, sc;
2513 >        if (tab != null) {
2514 >            if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2515 >                tryPresize(n << 1);
2516 >            else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2517 >                synchronized (b) {
2518 >                    if (tabAt(tab, index) == b) {
2519 >                        TreeNode<K,V> hd = null, tl = null;
2520 >                        for (Node<K,V> e = b; e != null; e = e.next) {
2521 >                            TreeNode<K,V> p =
2522 >                                new TreeNode<K,V>(e.hash, e.key, e.val,
2523 >                                                  null, null);
2524 >                            if ((p.prev = tl) == null)
2525 >                                hd = p;
2526 >                            else
2527 >                                tl.next = p;
2528 >                            tl = p;
2529 >                        }
2530 >                        setTabAt(tab, index, new TreeBin<K,V>(hd));
2531 >                    }
2532 >                }
2533 >            }
2534          }
2535      }
2536  
2537      /**
2538 <     * Returns a non-null result from applying the given search
3904 <     * function on each entry, or null if none.
3905 <     *
3906 <     * @param searchFunction a function returning a non-null
3907 <     * result on success, else null
3908 <     * @return a non-null result from applying the given search
3909 <     * function on each entry, or null if none
2538 >     * Returns a list on non-TreeNodes replacing those in given list.
2539       */
2540 <    @SuppressWarnings("unchecked") public <U> U searchEntriesSequentially
2541 <        (Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
2542 <        if (searchFunction == null) throw new NullPointerException();
2543 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2544 <        V v; U u;
2545 <        while ((v = it.advance()) != null) {
2546 <            if ((u = searchFunction.apply(entryFor((K)it.nextKey, v))) != null)
2547 <                return u;
2540 >    static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2541 >        Node<K,V> hd = null, tl = null;
2542 >        for (Node<K,V> q = b; q != null; q = q.next) {
2543 >            Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2544 >            if (tl == null)
2545 >                hd = p;
2546 >            else
2547 >                tl.next = p;
2548 >            tl = p;
2549          }
2550 <        return null;
2550 >        return hd;
2551      }
2552  
2553 +    /* ---------------- TreeNodes -------------- */
2554 +
2555      /**
2556 <     * Returns the result of accumulating all entries using the
3925 <     * given reducer to combine values, or null if none.
3926 <     *
3927 <     * @param reducer a commutative associative combining function
3928 <     * @return the result of accumulating all entries
2556 >     * Nodes for use in TreeBins
2557       */
2558 <    @SuppressWarnings("unchecked") public Map.Entry<K,V> reduceEntriesSequentially
2559 <        (BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
2560 <        if (reducer == null) throw new NullPointerException();
2561 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2562 <        Map.Entry<K,V> r = null; V v;
2563 <        while ((v = it.advance()) != null) {
2564 <            Map.Entry<K,V> u = entryFor((K)it.nextKey, v);
2565 <            r = (r == null) ? u : reducer.apply(r, u);
2558 >    static final class TreeNode<K,V> extends Node<K,V> {
2559 >        TreeNode<K,V> parent;  // red-black tree links
2560 >        TreeNode<K,V> left;
2561 >        TreeNode<K,V> right;
2562 >        TreeNode<K,V> prev;    // needed to unlink next upon deletion
2563 >        boolean red;
2564 >
2565 >        TreeNode(int hash, K key, V val, Node<K,V> next,
2566 >                 TreeNode<K,V> parent) {
2567 >            super(hash, key, val, next);
2568 >            this.parent = parent;
2569 >        }
2570 >
2571 >        Node<K,V> find(int h, Object k) {
2572 >            return findTreeNode(h, k, null);
2573 >        }
2574 >
2575 >        /**
2576 >         * Returns the TreeNode (or null if not found) for the given key
2577 >         * starting at given root.
2578 >         */
2579 >        final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2580 >            if (k != null) {
2581 >                TreeNode<K,V> p = this;
2582 >                do {
2583 >                    int ph, dir; K pk; TreeNode<K,V> q;
2584 >                    TreeNode<K,V> pl = p.left, pr = p.right;
2585 >                    if ((ph = p.hash) > h)
2586 >                        p = pl;
2587 >                    else if (ph < h)
2588 >                        p = pr;
2589 >                    else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2590 >                        return p;
2591 >                    else if (pl == null)
2592 >                        p = pr;
2593 >                    else if (pr == null)
2594 >                        p = pl;
2595 >                    else if ((kc != null ||
2596 >                              (kc = comparableClassFor(k)) != null) &&
2597 >                             (dir = compareComparables(kc, k, pk)) != 0)
2598 >                        p = (dir < 0) ? pl : pr;
2599 >                    else if ((q = pr.findTreeNode(h, k, kc)) != null)
2600 >                        return q;
2601 >                    else
2602 >                        p = pl;
2603 >                } while (p != null);
2604 >            }
2605 >            return null;
2606          }
3939        return r;
2607      }
2608  
2609 +    /* ---------------- TreeBins -------------- */
2610 +
2611      /**
2612 <     * Returns the result of accumulating the given transformation
2613 <     * of all entries using the given reducer to combine values,
2614 <     * or null if none.
2615 <     *
2616 <     * @param transformer a function returning the transformation
2617 <     * for an element, or null if there is no transformation (in
2618 <     * which case it is not combined).
2619 <     * @param reducer a commutative associative combining function
2620 <     * @return the result of accumulating the given transformation
2621 <     * of all entries
2622 <     */
2623 <    @SuppressWarnings("unchecked") public <U> U reduceEntriesSequentially
2624 <        (Fun<Map.Entry<K,V>, ? extends U> transformer,
2625 <         BiFun<? super U, ? super U, ? extends U> reducer) {
2626 <        if (transformer == null || reducer == null)
2627 <            throw new NullPointerException();
2628 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2629 <        U r = null, u; V v;
2630 <        while ((v = it.advance()) != null) {
2631 <            if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null)
2632 <                r = (r == null) ? u : reducer.apply(r, u);
2612 >     * TreeNodes used at the heads of bins. TreeBins do not hold user
2613 >     * keys or values, but instead point to list of TreeNodes and
2614 >     * their root. They also maintain a parasitic read-write lock
2615 >     * forcing writers (who hold bin lock) to wait for readers (who do
2616 >     * not) to complete before tree restructuring operations.
2617 >     */
2618 >    static final class TreeBin<K,V> extends Node<K,V> {
2619 >        TreeNode<K,V> root;
2620 >        volatile TreeNode<K,V> first;
2621 >        volatile Thread waiter;
2622 >        volatile int lockState;
2623 >        // values for lockState
2624 >        static final int WRITER = 1; // set while holding write lock
2625 >        static final int WAITER = 2; // set when waiting for write lock
2626 >        static final int READER = 4; // increment value for setting read lock
2627 >
2628 >        /**
2629 >         * Tie-breaking utility for ordering insertions when equal
2630 >         * hashCodes and non-comparable. We don't require a total
2631 >         * order, just a consistent insertion rule to maintain
2632 >         * equivalence across rebalancings. Tie-breaking further than
2633 >         * necessary simplifies testing a bit.
2634 >         */
2635 >        static int tieBreakOrder(Object a, Object b) {
2636 >            int d;
2637 >            if (a == null || b == null ||
2638 >                (d = a.getClass().getName().
2639 >                 compareTo(b.getClass().getName())) == 0)
2640 >                d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2641 >                     -1 : 1);
2642 >            return d;
2643 >        }
2644 >
2645 >        /**
2646 >         * Creates bin with initial set of nodes headed by b.
2647 >         */
2648 >        TreeBin(TreeNode<K,V> b) {
2649 >            super(TREEBIN, null, null, null);
2650 >            this.first = b;
2651 >            TreeNode<K,V> r = null;
2652 >            for (TreeNode<K,V> x = b, next; x != null; x = next) {
2653 >                next = (TreeNode<K,V>)x.next;
2654 >                x.left = x.right = null;
2655 >                if (r == null) {
2656 >                    x.parent = null;
2657 >                    x.red = false;
2658 >                    r = x;
2659 >                }
2660 >                else {
2661 >                    K k = x.key;
2662 >                    int h = x.hash;
2663 >                    Class<?> kc = null;
2664 >                    for (TreeNode<K,V> p = r;;) {
2665 >                        int dir, ph;
2666 >                        K pk = p.key;
2667 >                        if ((ph = p.hash) > h)
2668 >                            dir = -1;
2669 >                        else if (ph < h)
2670 >                            dir = 1;
2671 >                        else if ((kc == null &&
2672 >                                  (kc = comparableClassFor(k)) == null) ||
2673 >                                 (dir = compareComparables(kc, k, pk)) == 0)
2674 >                            dir = tieBreakOrder(k, pk);
2675 >                            TreeNode<K,V> xp = p;
2676 >                        if ((p = (dir <= 0) ? p.left : p.right) == null) {
2677 >                            x.parent = xp;
2678 >                            if (dir <= 0)
2679 >                                xp.left = x;
2680 >                            else
2681 >                                xp.right = x;
2682 >                            r = balanceInsertion(r, x);
2683 >                            break;
2684 >                        }
2685 >                    }
2686 >                }
2687 >            }
2688 >            this.root = r;
2689 >            assert checkInvariants(root);
2690 >        }
2691 >
2692 >        /**
2693 >         * Acquires write lock for tree restructuring.
2694 >         */
2695 >        private final void lockRoot() {
2696 >            if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2697 >                contendedLock(); // offload to separate method
2698 >        }
2699 >
2700 >        /**
2701 >         * Releases write lock for tree restructuring.
2702 >         */
2703 >        private final void unlockRoot() {
2704 >            lockState = 0;
2705 >        }
2706 >
2707 >        /**
2708 >         * Possibly blocks awaiting root lock.
2709 >         */
2710 >        private final void contendedLock() {
2711 >            boolean waiting = false;
2712 >            for (int s;;) {
2713 >                if (((s = lockState) & ~WAITER) == 0) {
2714 >                    if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2715 >                        if (waiting)
2716 >                            waiter = null;
2717 >                        return;
2718 >                    }
2719 >                }
2720 >                else if ((s & WAITER) == 0) {
2721 >                    if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2722 >                        waiting = true;
2723 >                        waiter = Thread.currentThread();
2724 >                    }
2725 >                }
2726 >                else if (waiting)
2727 >                    LockSupport.park(this);
2728 >            }
2729 >        }
2730 >
2731 >        /**
2732 >         * Returns matching node or null if none. Tries to search
2733 >         * using tree comparisons from root, but continues linear
2734 >         * search when lock not available.
2735 >         */
2736 >        final Node<K,V> find(int h, Object k) {
2737 >            if (k != null) {
2738 >                for (Node<K,V> e = first; e != null; ) {
2739 >                    int s; K ek;
2740 >                    if (((s = lockState) & (WAITER|WRITER)) != 0) {
2741 >                        if (e.hash == h &&
2742 >                            ((ek = e.key) == k || (ek != null && k.equals(ek))))
2743 >                            return e;
2744 >                        e = e.next;
2745 >                    }
2746 >                    else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2747 >                                                 s + READER)) {
2748 >                        TreeNode<K,V> r, p;
2749 >                        try {
2750 >                            p = ((r = root) == null ? null :
2751 >                                 r.findTreeNode(h, k, null));
2752 >                        } finally {
2753 >                            Thread w;
2754 >                            int ls;
2755 >                            do {} while (!U.compareAndSwapInt
2756 >                                         (this, LOCKSTATE,
2757 >                                          ls = lockState, ls - READER));
2758 >                            if (ls == (READER|WAITER) && (w = waiter) != null)
2759 >                                LockSupport.unpark(w);
2760 >                        }
2761 >                        return p;
2762 >                    }
2763 >                }
2764 >            }
2765 >            return null;
2766 >        }
2767 >
2768 >        /**
2769 >         * Finds or adds a node.
2770 >         * @return null if added
2771 >         */
2772 >        final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2773 >            Class<?> kc = null;
2774 >            boolean searched = false;
2775 >            for (TreeNode<K,V> p = root;;) {
2776 >                int dir, ph; K pk;
2777 >                if (p == null) {
2778 >                    first = root = new TreeNode<K,V>(h, k, v, null, null);
2779 >                    break;
2780 >                }
2781 >                else if ((ph = p.hash) > h)
2782 >                    dir = -1;
2783 >                else if (ph < h)
2784 >                    dir = 1;
2785 >                else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2786 >                    return p;
2787 >                else if ((kc == null &&
2788 >                          (kc = comparableClassFor(k)) == null) ||
2789 >                         (dir = compareComparables(kc, k, pk)) == 0) {
2790 >                    if (!searched) {
2791 >                        TreeNode<K,V> q, ch;
2792 >                        searched = true;
2793 >                        if (((ch = p.left) != null &&
2794 >                             (q = ch.findTreeNode(h, k, kc)) != null) ||
2795 >                            ((ch = p.right) != null &&
2796 >                             (q = ch.findTreeNode(h, k, kc)) != null))
2797 >                            return q;
2798 >                    }
2799 >                    dir = tieBreakOrder(k, pk);
2800 >                }
2801 >
2802 >                TreeNode<K,V> xp = p;
2803 >                if ((p = (dir <= 0) ? p.left : p.right) == null) {
2804 >                    TreeNode<K,V> x, f = first;
2805 >                    first = x = new TreeNode<K,V>(h, k, v, f, xp);
2806 >                    if (f != null)
2807 >                        f.prev = x;
2808 >                    if (dir <= 0)
2809 >                        xp.left = x;
2810 >                    else
2811 >                        xp.right = x;
2812 >                    if (!xp.red)
2813 >                        x.red = true;
2814 >                    else {
2815 >                        lockRoot();
2816 >                        try {
2817 >                            root = balanceInsertion(root, x);
2818 >                        } finally {
2819 >                            unlockRoot();
2820 >                        }
2821 >                    }
2822 >                    break;
2823 >                }
2824 >            }
2825 >            assert checkInvariants(root);
2826 >            return null;
2827 >        }
2828 >
2829 >        /**
2830 >         * Removes the given node, that must be present before this
2831 >         * call.  This is messier than typical red-black deletion code
2832 >         * because we cannot swap the contents of an interior node
2833 >         * with a leaf successor that is pinned by "next" pointers
2834 >         * that are accessible independently of lock. So instead we
2835 >         * swap the tree linkages.
2836 >         *
2837 >         * @return true if now too small, so should be untreeified
2838 >         */
2839 >        final boolean removeTreeNode(TreeNode<K,V> p) {
2840 >            TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2841 >            TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2842 >            TreeNode<K,V> r, rl;
2843 >            if (pred == null)
2844 >                first = next;
2845 >            else
2846 >                pred.next = next;
2847 >            if (next != null)
2848 >                next.prev = pred;
2849 >            if (first == null) {
2850 >                root = null;
2851 >                return true;
2852 >            }
2853 >            if ((r = root) == null || r.right == null || // too small
2854 >                (rl = r.left) == null || rl.left == null)
2855 >                return true;
2856 >            lockRoot();
2857 >            try {
2858 >                TreeNode<K,V> replacement;
2859 >                TreeNode<K,V> pl = p.left;
2860 >                TreeNode<K,V> pr = p.right;
2861 >                if (pl != null && pr != null) {
2862 >                    TreeNode<K,V> s = pr, sl;
2863 >                    while ((sl = s.left) != null) // find successor
2864 >                        s = sl;
2865 >                    boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2866 >                    TreeNode<K,V> sr = s.right;
2867 >                    TreeNode<K,V> pp = p.parent;
2868 >                    if (s == pr) { // p was s's direct parent
2869 >                        p.parent = s;
2870 >                        s.right = p;
2871 >                    }
2872 >                    else {
2873 >                        TreeNode<K,V> sp = s.parent;
2874 >                        if ((p.parent = sp) != null) {
2875 >                            if (s == sp.left)
2876 >                                sp.left = p;
2877 >                            else
2878 >                                sp.right = p;
2879 >                        }
2880 >                        if ((s.right = pr) != null)
2881 >                            pr.parent = s;
2882 >                    }
2883 >                    p.left = null;
2884 >                    if ((p.right = sr) != null)
2885 >                        sr.parent = p;
2886 >                    if ((s.left = pl) != null)
2887 >                        pl.parent = s;
2888 >                    if ((s.parent = pp) == null)
2889 >                        r = s;
2890 >                    else if (p == pp.left)
2891 >                        pp.left = s;
2892 >                    else
2893 >                        pp.right = s;
2894 >                    if (sr != null)
2895 >                        replacement = sr;
2896 >                    else
2897 >                        replacement = p;
2898 >                }
2899 >                else if (pl != null)
2900 >                    replacement = pl;
2901 >                else if (pr != null)
2902 >                    replacement = pr;
2903 >                else
2904 >                    replacement = p;
2905 >                if (replacement != p) {
2906 >                    TreeNode<K,V> pp = replacement.parent = p.parent;
2907 >                    if (pp == null)
2908 >                        r = replacement;
2909 >                    else if (p == pp.left)
2910 >                        pp.left = replacement;
2911 >                    else
2912 >                        pp.right = replacement;
2913 >                    p.left = p.right = p.parent = null;
2914 >                }
2915 >
2916 >                root = (p.red) ? r : balanceDeletion(r, replacement);
2917 >
2918 >                if (p == replacement) {  // detach pointers
2919 >                    TreeNode<K,V> pp;
2920 >                    if ((pp = p.parent) != null) {
2921 >                        if (p == pp.left)
2922 >                            pp.left = null;
2923 >                        else if (p == pp.right)
2924 >                            pp.right = null;
2925 >                        p.parent = null;
2926 >                    }
2927 >                }
2928 >            } finally {
2929 >                unlockRoot();
2930 >            }
2931 >            assert checkInvariants(root);
2932 >            return false;
2933 >        }
2934 >
2935 >        /* ------------------------------------------------------------ */
2936 >        // Red-black tree methods, all adapted from CLR
2937 >
2938 >        static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2939 >                                              TreeNode<K,V> p) {
2940 >            TreeNode<K,V> r, pp, rl;
2941 >            if (p != null && (r = p.right) != null) {
2942 >                if ((rl = p.right = r.left) != null)
2943 >                    rl.parent = p;
2944 >                if ((pp = r.parent = p.parent) == null)
2945 >                    (root = r).red = false;
2946 >                else if (pp.left == p)
2947 >                    pp.left = r;
2948 >                else
2949 >                    pp.right = r;
2950 >                r.left = p;
2951 >                p.parent = r;
2952 >            }
2953 >            return root;
2954 >        }
2955 >
2956 >        static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2957 >                                               TreeNode<K,V> p) {
2958 >            TreeNode<K,V> l, pp, lr;
2959 >            if (p != null && (l = p.left) != null) {
2960 >                if ((lr = p.left = l.right) != null)
2961 >                    lr.parent = p;
2962 >                if ((pp = l.parent = p.parent) == null)
2963 >                    (root = l).red = false;
2964 >                else if (pp.right == p)
2965 >                    pp.right = l;
2966 >                else
2967 >                    pp.left = l;
2968 >                l.right = p;
2969 >                p.parent = l;
2970 >            }
2971 >            return root;
2972 >        }
2973 >
2974 >        static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2975 >                                                    TreeNode<K,V> x) {
2976 >            x.red = true;
2977 >            for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2978 >                if ((xp = x.parent) == null) {
2979 >                    x.red = false;
2980 >                    return x;
2981 >                }
2982 >                else if (!xp.red || (xpp = xp.parent) == null)
2983 >                    return root;
2984 >                if (xp == (xppl = xpp.left)) {
2985 >                    if ((xppr = xpp.right) != null && xppr.red) {
2986 >                        xppr.red = false;
2987 >                        xp.red = false;
2988 >                        xpp.red = true;
2989 >                        x = xpp;
2990 >                    }
2991 >                    else {
2992 >                        if (x == xp.right) {
2993 >                            root = rotateLeft(root, x = xp);
2994 >                            xpp = (xp = x.parent) == null ? null : xp.parent;
2995 >                        }
2996 >                        if (xp != null) {
2997 >                            xp.red = false;
2998 >                            if (xpp != null) {
2999 >                                xpp.red = true;
3000 >                                root = rotateRight(root, xpp);
3001 >                            }
3002 >                        }
3003 >                    }
3004 >                }
3005 >                else {
3006 >                    if (xppl != null && xppl.red) {
3007 >                        xppl.red = false;
3008 >                        xp.red = false;
3009 >                        xpp.red = true;
3010 >                        x = xpp;
3011 >                    }
3012 >                    else {
3013 >                        if (x == xp.left) {
3014 >                            root = rotateRight(root, x = xp);
3015 >                            xpp = (xp = x.parent) == null ? null : xp.parent;
3016 >                        }
3017 >                        if (xp != null) {
3018 >                            xp.red = false;
3019 >                            if (xpp != null) {
3020 >                                xpp.red = true;
3021 >                                root = rotateLeft(root, xpp);
3022 >                            }
3023 >                        }
3024 >                    }
3025 >                }
3026 >            }
3027 >        }
3028 >
3029 >        static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3030 >                                                   TreeNode<K,V> x) {
3031 >            for (TreeNode<K,V> xp, xpl, xpr;;) {
3032 >                if (x == null || x == root)
3033 >                    return root;
3034 >                else if ((xp = x.parent) == null) {
3035 >                    x.red = false;
3036 >                    return x;
3037 >                }
3038 >                else if (x.red) {
3039 >                    x.red = false;
3040 >                    return root;
3041 >                }
3042 >                else if ((xpl = xp.left) == x) {
3043 >                    if ((xpr = xp.right) != null && xpr.red) {
3044 >                        xpr.red = false;
3045 >                        xp.red = true;
3046 >                        root = rotateLeft(root, xp);
3047 >                        xpr = (xp = x.parent) == null ? null : xp.right;
3048 >                    }
3049 >                    if (xpr == null)
3050 >                        x = xp;
3051 >                    else {
3052 >                        TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3053 >                        if ((sr == null || !sr.red) &&
3054 >                            (sl == null || !sl.red)) {
3055 >                            xpr.red = true;
3056 >                            x = xp;
3057 >                        }
3058 >                        else {
3059 >                            if (sr == null || !sr.red) {
3060 >                                if (sl != null)
3061 >                                    sl.red = false;
3062 >                                xpr.red = true;
3063 >                                root = rotateRight(root, xpr);
3064 >                                xpr = (xp = x.parent) == null ?
3065 >                                    null : xp.right;
3066 >                            }
3067 >                            if (xpr != null) {
3068 >                                xpr.red = (xp == null) ? false : xp.red;
3069 >                                if ((sr = xpr.right) != null)
3070 >                                    sr.red = false;
3071 >                            }
3072 >                            if (xp != null) {
3073 >                                xp.red = false;
3074 >                                root = rotateLeft(root, xp);
3075 >                            }
3076 >                            x = root;
3077 >                        }
3078 >                    }
3079 >                }
3080 >                else { // symmetric
3081 >                    if (xpl != null && xpl.red) {
3082 >                        xpl.red = false;
3083 >                        xp.red = true;
3084 >                        root = rotateRight(root, xp);
3085 >                        xpl = (xp = x.parent) == null ? null : xp.left;
3086 >                    }
3087 >                    if (xpl == null)
3088 >                        x = xp;
3089 >                    else {
3090 >                        TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3091 >                        if ((sl == null || !sl.red) &&
3092 >                            (sr == null || !sr.red)) {
3093 >                            xpl.red = true;
3094 >                            x = xp;
3095 >                        }
3096 >                        else {
3097 >                            if (sl == null || !sl.red) {
3098 >                                if (sr != null)
3099 >                                    sr.red = false;
3100 >                                xpl.red = true;
3101 >                                root = rotateLeft(root, xpl);
3102 >                                xpl = (xp = x.parent) == null ?
3103 >                                    null : xp.left;
3104 >                            }
3105 >                            if (xpl != null) {
3106 >                                xpl.red = (xp == null) ? false : xp.red;
3107 >                                if ((sl = xpl.left) != null)
3108 >                                    sl.red = false;
3109 >                            }
3110 >                            if (xp != null) {
3111 >                                xp.red = false;
3112 >                                root = rotateRight(root, xp);
3113 >                            }
3114 >                            x = root;
3115 >                        }
3116 >                    }
3117 >                }
3118 >            }
3119 >        }
3120 >
3121 >        /**
3122 >         * Recursive invariant check
3123 >         */
3124 >        static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3125 >            TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3126 >                tb = t.prev, tn = (TreeNode<K,V>)t.next;
3127 >            if (tb != null && tb.next != t)
3128 >                return false;
3129 >            if (tn != null && tn.prev != t)
3130 >                return false;
3131 >            if (tp != null && t != tp.left && t != tp.right)
3132 >                return false;
3133 >            if (tl != null && (tl.parent != t || tl.hash > t.hash))
3134 >                return false;
3135 >            if (tr != null && (tr.parent != t || tr.hash < t.hash))
3136 >                return false;
3137 >            if (t.red && tl != null && tl.red && tr != null && tr.red)
3138 >                return false;
3139 >            if (tl != null && !checkInvariants(tl))
3140 >                return false;
3141 >            if (tr != null && !checkInvariants(tr))
3142 >                return false;
3143 >            return true;
3144 >        }
3145 >
3146 >        private static final sun.misc.Unsafe U;
3147 >        private static final long LOCKSTATE;
3148 >        static {
3149 >            try {
3150 >                U = getUnsafe();
3151 >                Class<?> k = TreeBin.class;
3152 >                LOCKSTATE = U.objectFieldOffset
3153 >                    (k.getDeclaredField("lockState"));
3154 >            } catch (Exception e) {
3155 >                throw new Error(e);
3156 >            }
3157          }
3965        return r;
3158      }
3159  
3160 +    /* ----------------Table Traversal -------------- */
3161 +
3162      /**
3163 <     * Returns the result of accumulating the given transformation
3164 <     * of all entries using the given reducer to combine values,
3165 <     * and the given basis as an identity value.
3166 <     *
3167 <     * @param transformer a function returning the transformation
3168 <     * for an element
3169 <     * @param basis the identity (initial default value) for the reduction
3170 <     * @param reducer a commutative associative combining function
3171 <     * @return the result of accumulating the given transformation
3978 <     * of all entries
3979 <     */
3980 <    @SuppressWarnings("unchecked") public double reduceEntriesToDoubleSequentially
3981 <        (ObjectToDouble<Map.Entry<K,V>> transformer,
3982 <         double basis,
3983 <         DoubleByDoubleToDouble reducer) {
3984 <        if (transformer == null || reducer == null)
3985 <            throw new NullPointerException();
3986 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3987 <        double r = basis; V v;
3988 <        while ((v = it.advance()) != null)
3989 <            r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v)));
3990 <        return r;
3163 >     * Records the table, its length, and current traversal index for a
3164 >     * traverser that must process a region of a forwarded table before
3165 >     * proceeding with current table.
3166 >     */
3167 >    static final class TableStack<K,V> {
3168 >        int length;
3169 >        int index;
3170 >        Node<K,V>[] tab;
3171 >        TableStack<K,V> next;
3172      }
3173  
3174      /**
3175 <     * Returns the result of accumulating the given transformation
3176 <     * of all entries using the given reducer to combine values,
3996 <     * and the given basis as an identity value.
3175 >     * Encapsulates traversal for methods such as containsValue; also
3176 >     * serves as a base class for other iterators and spliterators.
3177       *
3178 <     * @param transformer a function returning the transformation
3179 <     * for an element
3180 <     * @param basis the identity (initial default value) for the reduction
3181 <     * @param reducer a commutative associative combining function
3182 <     * @return  the result of accumulating the given transformation
3183 <     * of all entries
3178 >     * Method advance visits once each still-valid node that was
3179 >     * reachable upon iterator construction. It might miss some that
3180 >     * were added to a bin after the bin was visited, which is OK wrt
3181 >     * consistency guarantees. Maintaining this property in the face
3182 >     * of possible ongoing resizes requires a fair amount of
3183 >     * bookkeeping state that is difficult to optimize away amidst
3184 >     * volatile accesses.  Even so, traversal maintains reasonable
3185 >     * throughput.
3186 >     *
3187 >     * Normally, iteration proceeds bin-by-bin traversing lists.
3188 >     * However, if the table has been resized, then all future steps
3189 >     * must traverse both the bin at the current index as well as at
3190 >     * (index + baseSize); and so on for further resizings. To
3191 >     * paranoically cope with potential sharing by users of iterators
3192 >     * across threads, iteration terminates if a bounds checks fails
3193 >     * for a table read.
3194       */
3195 <    @SuppressWarnings("unchecked") public long reduceEntriesToLongSequentially
3196 <        (ObjectToLong<Map.Entry<K,V>> transformer,
3197 <         long basis,
3198 <         LongByLongToLong reducer) {
3199 <        if (transformer == null || reducer == null)
3200 <            throw new NullPointerException();
3201 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3202 <        long r = basis; V v;
3203 <        while ((v = it.advance()) != null)
3204 <            r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v)));
3205 <        return r;
3195 >    static class Traverser<K,V> {
3196 >        Node<K,V>[] tab;        // current table; updated if resized
3197 >        Node<K,V> next;         // the next entry to use
3198 >        TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3199 >        int index;              // index of bin to use next
3200 >        int baseIndex;          // current index of initial table
3201 >        int baseLimit;          // index bound for initial table
3202 >        final int baseSize;     // initial table size
3203 >
3204 >        Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3205 >            this.tab = tab;
3206 >            this.baseSize = size;
3207 >            this.baseIndex = this.index = index;
3208 >            this.baseLimit = limit;
3209 >            this.next = null;
3210 >        }
3211 >
3212 >        /**
3213 >         * Advances if possible, returning next valid node, or null if none.
3214 >         */
3215 >        final Node<K,V> advance() {
3216 >            Node<K,V> e;
3217 >            if ((e = next) != null)
3218 >                e = e.next;
3219 >            for (;;) {
3220 >                Node<K,V>[] t; int i, n;  // must use locals in checks
3221 >                if (e != null)
3222 >                    return next = e;
3223 >                if (baseIndex >= baseLimit || (t = tab) == null ||
3224 >                    (n = t.length) <= (i = index) || i < 0)
3225 >                    return next = null;
3226 >                if ((e = tabAt(t, i)) != null && e.hash < 0) {
3227 >                    if (e instanceof ForwardingNode) {
3228 >                        tab = ((ForwardingNode<K,V>)e).nextTable;
3229 >                        e = null;
3230 >                        pushState(t, i, n);
3231 >                        continue;
3232 >                    }
3233 >                    else if (e instanceof TreeBin)
3234 >                        e = ((TreeBin<K,V>)e).first;
3235 >                    else
3236 >                        e = null;
3237 >                }
3238 >                if (stack != null)
3239 >                    recoverState(n);
3240 >                else if ((index = i + baseSize) >= n)
3241 >                    index = ++baseIndex; // visit upper slots if present
3242 >            }
3243 >        }
3244 >
3245 >        /**
3246 >         * Saves traversal state upon encountering a forwarding node.
3247 >         */
3248 >        private void pushState(Node<K,V>[] t, int i, int n) {
3249 >            TableStack<K,V> s = spare;  // reuse if possible
3250 >            if (s != null)
3251 >                spare = s.next;
3252 >            else
3253 >                s = new TableStack<K,V>();
3254 >            s.tab = t;
3255 >            s.length = n;
3256 >            s.index = i;
3257 >            s.next = stack;
3258 >            stack = s;
3259 >        }
3260 >
3261 >        /**
3262 >         * Possibly pops traversal state.
3263 >         *
3264 >         * @param n length of current table
3265 >         */
3266 >        private void recoverState(int n) {
3267 >            TableStack<K,V> s; int len;
3268 >            while ((s = stack) != null && (index += (len = s.length)) >= n) {
3269 >                n = len;
3270 >                index = s.index;
3271 >                tab = s.tab;
3272 >                s.tab = null;
3273 >                TableStack<K,V> next = s.next;
3274 >                s.next = spare; // save for reuse
3275 >                stack = next;
3276 >                spare = s;
3277 >            }
3278 >            if (s == null && (index += baseSize) >= n)
3279 >                index = ++baseIndex;
3280 >        }
3281      }
3282  
3283      /**
3284 <     * Returns the result of accumulating the given transformation
3285 <     * of all entries using the given reducer to combine values,
3286 <     * and the given basis as an identity value.
3287 <     *
3288 <     * @param transformer a function returning the transformation
3289 <     * for an element
3290 <     * @param basis the identity (initial default value) for the reduction
3291 <     * @param reducer a commutative associative combining function
3292 <     * @return the result of accumulating the given transformation
3293 <     * of all entries
3284 >     * Base of key, value, and entry Iterators. Adds fields to
3285 >     * Traverser to support iterator.remove.
3286 >     */
3287 >    static class BaseIterator<K,V> extends Traverser<K,V> {
3288 >        final ConcurrentHashMapV8<K,V> map;
3289 >        Node<K,V> lastReturned;
3290 >        BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3291 >                    ConcurrentHashMapV8<K,V> map) {
3292 >            super(tab, size, index, limit);
3293 >            this.map = map;
3294 >            advance();
3295 >        }
3296 >
3297 >        public final boolean hasNext() { return next != null; }
3298 >        public final boolean hasMoreElements() { return next != null; }
3299 >
3300 >        public final void remove() {
3301 >            Node<K,V> p;
3302 >            if ((p = lastReturned) == null)
3303 >                throw new IllegalStateException();
3304 >            lastReturned = null;
3305 >            map.replaceNode(p.key, null, null);
3306 >        }
3307 >    }
3308 >
3309 >    static final class KeyIterator<K,V> extends BaseIterator<K,V>
3310 >        implements Iterator<K>, Enumeration<K> {
3311 >        KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3312 >                    ConcurrentHashMapV8<K,V> map) {
3313 >            super(tab, index, size, limit, map);
3314 >        }
3315 >
3316 >        public final K next() {
3317 >            Node<K,V> p;
3318 >            if ((p = next) == null)
3319 >                throw new NoSuchElementException();
3320 >            K k = p.key;
3321 >            lastReturned = p;
3322 >            advance();
3323 >            return k;
3324 >        }
3325 >
3326 >        public final K nextElement() { return next(); }
3327 >    }
3328 >
3329 >    static final class ValueIterator<K,V> extends BaseIterator<K,V>
3330 >        implements Iterator<V>, Enumeration<V> {
3331 >        ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3332 >                      ConcurrentHashMapV8<K,V> map) {
3333 >            super(tab, index, size, limit, map);
3334 >        }
3335 >
3336 >        public final V next() {
3337 >            Node<K,V> p;
3338 >            if ((p = next) == null)
3339 >                throw new NoSuchElementException();
3340 >            V v = p.val;
3341 >            lastReturned = p;
3342 >            advance();
3343 >            return v;
3344 >        }
3345 >
3346 >        public final V nextElement() { return next(); }
3347 >    }
3348 >
3349 >    static final class EntryIterator<K,V> extends BaseIterator<K,V>
3350 >        implements Iterator<Map.Entry<K,V>> {
3351 >        EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3352 >                      ConcurrentHashMapV8<K,V> map) {
3353 >            super(tab, index, size, limit, map);
3354 >        }
3355 >
3356 >        public final Map.Entry<K,V> next() {
3357 >            Node<K,V> p;
3358 >            if ((p = next) == null)
3359 >                throw new NoSuchElementException();
3360 >            K k = p.key;
3361 >            V v = p.val;
3362 >            lastReturned = p;
3363 >            advance();
3364 >            return new MapEntry<K,V>(k, v, map);
3365 >        }
3366 >    }
3367 >
3368 >    /**
3369 >     * Exported Entry for EntryIterator
3370       */
3371 <    @SuppressWarnings("unchecked") public int reduceEntriesToIntSequentially
3372 <        (ObjectToInt<Map.Entry<K,V>> transformer,
3373 <         int basis,
3374 <         IntByIntToInt reducer) {
3375 <        if (transformer == null || reducer == null)
3376 <            throw new NullPointerException();
3377 <        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3378 <        int r = basis; V v;
3379 <        while ((v = it.advance()) != null)
3380 <            r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v)));
3381 <        return r;
3371 >    static final class MapEntry<K,V> implements Map.Entry<K,V> {
3372 >        final K key; // non-null
3373 >        V val;       // non-null
3374 >        final ConcurrentHashMapV8<K,V> map;
3375 >        MapEntry(K key, V val, ConcurrentHashMapV8<K,V> map) {
3376 >            this.key = key;
3377 >            this.val = val;
3378 >            this.map = map;
3379 >        }
3380 >        public K getKey()        { return key; }
3381 >        public V getValue()      { return val; }
3382 >        public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3383 >        public String toString() { return key + "=" + val; }
3384 >
3385 >        public boolean equals(Object o) {
3386 >            Object k, v; Map.Entry<?,?> e;
3387 >            return ((o instanceof Map.Entry) &&
3388 >                    (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3389 >                    (v = e.getValue()) != null &&
3390 >                    (k == key || k.equals(key)) &&
3391 >                    (v == val || v.equals(val)));
3392 >        }
3393 >
3394 >        /**
3395 >         * Sets our entry's value and writes through to the map. The
3396 >         * value to return is somewhat arbitrary here. Since we do not
3397 >         * necessarily track asynchronous changes, the most recent
3398 >         * "previous" value could be different from what we return (or
3399 >         * could even have been removed, in which case the put will
3400 >         * re-establish). We do not and cannot guarantee more.
3401 >         */
3402 >        public V setValue(V value) {
3403 >            if (value == null) throw new NullPointerException();
3404 >            V v = val;
3405 >            val = value;
3406 >            map.put(key, value);
3407 >            return v;
3408 >        }
3409 >    }
3410 >
3411 >    static final class KeySpliterator<K,V> extends Traverser<K,V>
3412 >        implements ConcurrentHashMapSpliterator<K> {
3413 >        long est;               // size estimate
3414 >        KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3415 >                       long est) {
3416 >            super(tab, size, index, limit);
3417 >            this.est = est;
3418 >        }
3419 >
3420 >        public ConcurrentHashMapSpliterator<K> trySplit() {
3421 >            int i, f, h;
3422 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3423 >                new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3424 >                                        f, est >>>= 1);
3425 >        }
3426 >
3427 >        public void forEachRemaining(Action<? super K> action) {
3428 >            if (action == null) throw new NullPointerException();
3429 >            for (Node<K,V> p; (p = advance()) != null;)
3430 >                action.apply(p.key);
3431 >        }
3432 >
3433 >        public boolean tryAdvance(Action<? super K> action) {
3434 >            if (action == null) throw new NullPointerException();
3435 >            Node<K,V> p;
3436 >            if ((p = advance()) == null)
3437 >                return false;
3438 >            action.apply(p.key);
3439 >            return true;
3440 >        }
3441 >
3442 >        public long estimateSize() { return est; }
3443 >
3444 >    }
3445 >
3446 >    static final class ValueSpliterator<K,V> extends Traverser<K,V>
3447 >        implements ConcurrentHashMapSpliterator<V> {
3448 >        long est;               // size estimate
3449 >        ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3450 >                         long est) {
3451 >            super(tab, size, index, limit);
3452 >            this.est = est;
3453 >        }
3454 >
3455 >        public ConcurrentHashMapSpliterator<V> trySplit() {
3456 >            int i, f, h;
3457 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3458 >                new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3459 >                                          f, est >>>= 1);
3460 >        }
3461 >
3462 >        public void forEachRemaining(Action<? super V> action) {
3463 >            if (action == null) throw new NullPointerException();
3464 >            for (Node<K,V> p; (p = advance()) != null;)
3465 >                action.apply(p.val);
3466 >        }
3467 >
3468 >        public boolean tryAdvance(Action<? super V> action) {
3469 >            if (action == null) throw new NullPointerException();
3470 >            Node<K,V> p;
3471 >            if ((p = advance()) == null)
3472 >                return false;
3473 >            action.apply(p.val);
3474 >            return true;
3475 >        }
3476 >
3477 >        public long estimateSize() { return est; }
3478 >
3479 >    }
3480 >
3481 >    static final class EntrySpliterator<K,V> extends Traverser<K,V>
3482 >        implements ConcurrentHashMapSpliterator<Map.Entry<K,V>> {
3483 >        final ConcurrentHashMapV8<K,V> map; // To export MapEntry
3484 >        long est;               // size estimate
3485 >        EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3486 >                         long est, ConcurrentHashMapV8<K,V> map) {
3487 >            super(tab, size, index, limit);
3488 >            this.map = map;
3489 >            this.est = est;
3490 >        }
3491 >
3492 >        public ConcurrentHashMapSpliterator<Map.Entry<K,V>> trySplit() {
3493 >            int i, f, h;
3494 >            return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3495 >                new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3496 >                                          f, est >>>= 1, map);
3497 >        }
3498 >
3499 >        public void forEachRemaining(Action<? super Map.Entry<K,V>> action) {
3500 >            if (action == null) throw new NullPointerException();
3501 >            for (Node<K,V> p; (p = advance()) != null; )
3502 >                action.apply(new MapEntry<K,V>(p.key, p.val, map));
3503 >        }
3504 >
3505 >        public boolean tryAdvance(Action<? super Map.Entry<K,V>> action) {
3506 >            if (action == null) throw new NullPointerException();
3507 >            Node<K,V> p;
3508 >            if ((p = advance()) == null)
3509 >                return false;
3510 >            action.apply(new MapEntry<K,V>(p.key, p.val, map));
3511 >            return true;
3512 >        }
3513 >
3514 >        public long estimateSize() { return est; }
3515 >
3516      }
3517  
3518      // Parallel bulk operations
3519  
3520      /**
3521 +     * Computes initial batch value for bulk tasks. The returned value
3522 +     * is approximately exp2 of the number of times (minus one) to
3523 +     * split task by two before executing leaf action. This value is
3524 +     * faster to compute and more convenient to use as a guide to
3525 +     * splitting than is the depth, since it is used while dividing by
3526 +     * two anyway.
3527 +     */
3528 +    final int batchFor(long b) {
3529 +        long n;
3530 +        if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3531 +            return 0;
3532 +        int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3533 +        return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3534 +    }
3535 +
3536 +    /**
3537       * Performs the given action for each (key, value).
3538       *
3539 +     * @param parallelismThreshold the (estimated) number of elements
3540 +     * needed for this operation to be executed in parallel
3541       * @param action the action
3542 +     * @since 1.8
3543       */
3544 <    public void forEachInParallel(BiAction<K,V> action) {
3545 <        ForkJoinTasks.forEach
3546 <            (this, action).invoke();
3544 >    public void forEach(long parallelismThreshold,
3545 >                        BiAction<? super K,? super V> action) {
3546 >        if (action == null) throw new NullPointerException();
3547 >        new ForEachMappingTask<K,V>
3548 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3549 >             action).invoke();
3550      }
3551  
3552      /**
3553       * Performs the given action for each non-null transformation
3554       * of each (key, value).
3555       *
3556 +     * @param parallelismThreshold the (estimated) number of elements
3557 +     * needed for this operation to be executed in parallel
3558       * @param transformer a function returning the transformation
3559       * for an element, or null if there is no transformation (in
3560 <     * which case the action is not applied).
3560 >     * which case the action is not applied)
3561       * @param action the action
3562 +     * @since 1.8
3563       */
3564 <    public <U> void forEachInParallel
3565 <        (BiFun<? super K, ? super V, ? extends U> transformer,
3566 <                            Action<U> action) {
3567 <        ForkJoinTasks.forEach
3568 <            (this, transformer, action).invoke();
3564 >    public <U> void forEach(long parallelismThreshold,
3565 >                            BiFun<? super K, ? super V, ? extends U> transformer,
3566 >                            Action<? super U> action) {
3567 >        if (transformer == null || action == null)
3568 >            throw new NullPointerException();
3569 >        new ForEachTransformedMappingTask<K,V,U>
3570 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3571 >             transformer, action).invoke();
3572      }
3573  
3574      /**
# Line 4075 | Line 3578 | public class ConcurrentHashMapV8<K, V>
3578       * results of any other parallel invocations of the search
3579       * function are ignored.
3580       *
3581 +     * @param parallelismThreshold the (estimated) number of elements
3582 +     * needed for this operation to be executed in parallel
3583       * @param searchFunction a function returning a non-null
3584       * result on success, else null
3585       * @return a non-null result from applying the given search
3586       * function on each (key, value), or null if none
3587 +     * @since 1.8
3588       */
3589 <    public <U> U searchInParallel
3590 <        (BiFun<? super K, ? super V, ? extends U> searchFunction) {
3591 <        return ForkJoinTasks.search
3592 <            (this, searchFunction).invoke();
3589 >    public <U> U search(long parallelismThreshold,
3590 >                        BiFun<? super K, ? super V, ? extends U> searchFunction) {
3591 >        if (searchFunction == null) throw new NullPointerException();
3592 >        return new SearchMappingsTask<K,V,U>
3593 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3594 >             searchFunction, new AtomicReference<U>()).invoke();
3595      }
3596  
3597      /**
# Line 4091 | Line 3599 | public class ConcurrentHashMapV8<K, V>
3599       * of all (key, value) pairs using the given reducer to
3600       * combine values, or null if none.
3601       *
3602 +     * @param parallelismThreshold the (estimated) number of elements
3603 +     * needed for this operation to be executed in parallel
3604       * @param transformer a function returning the transformation
3605       * for an element, or null if there is no transformation (in
3606 <     * which case it is not combined).
3606 >     * which case it is not combined)
3607       * @param reducer a commutative associative combining function
3608       * @return the result of accumulating the given transformation
3609       * of all (key, value) pairs
3610 +     * @since 1.8
3611       */
3612 <    public <U> U reduceInParallel
3613 <        (BiFun<? super K, ? super V, ? extends U> transformer,
3614 <         BiFun<? super U, ? super U, ? extends U> reducer) {
3615 <        return ForkJoinTasks.reduce
3616 <            (this, transformer, reducer).invoke();
3612 >    public <U> U reduce(long parallelismThreshold,
3613 >                        BiFun<? super K, ? super V, ? extends U> transformer,
3614 >                        BiFun<? super U, ? super U, ? extends U> reducer) {
3615 >        if (transformer == null || reducer == null)
3616 >            throw new NullPointerException();
3617 >        return new MapReduceMappingsTask<K,V,U>
3618 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3619 >             null, transformer, reducer).invoke();
3620      }
3621  
3622      /**
# Line 4110 | Line 3624 | public class ConcurrentHashMapV8<K, V>
3624       * of all (key, value) pairs using the given reducer to
3625       * combine values, and the given basis as an identity value.
3626       *
3627 +     * @param parallelismThreshold the (estimated) number of elements
3628 +     * needed for this operation to be executed in parallel
3629       * @param transformer a function returning the transformation
3630       * for an element
3631       * @param basis the identity (initial default value) for the reduction
3632       * @param reducer a commutative associative combining function
3633       * @return the result of accumulating the given transformation
3634       * of all (key, value) pairs
3635 +     * @since 1.8
3636       */
3637 <    public double reduceToDoubleInParallel
3638 <        (ObjectByObjectToDouble<? super K, ? super V> transformer,
3639 <         double basis,
3640 <         DoubleByDoubleToDouble reducer) {
3641 <        return ForkJoinTasks.reduceToDouble
3642 <            (this, transformer, basis, reducer).invoke();
3637 >    public double reduceToDouble(long parallelismThreshold,
3638 >                                 ObjectByObjectToDouble<? super K, ? super V> transformer,
3639 >                                 double basis,
3640 >                                 DoubleByDoubleToDouble reducer) {
3641 >        if (transformer == null || reducer == null)
3642 >            throw new NullPointerException();
3643 >        return new MapReduceMappingsToDoubleTask<K,V>
3644 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3645 >             null, transformer, basis, reducer).invoke();
3646      }
3647  
3648      /**
# Line 4130 | Line 3650 | public class ConcurrentHashMapV8<K, V>
3650       * of all (key, value) pairs using the given reducer to
3651       * combine values, and the given basis as an identity value.
3652       *
3653 +     * @param parallelismThreshold the (estimated) number of elements
3654 +     * needed for this operation to be executed in parallel
3655       * @param transformer a function returning the transformation
3656       * for an element
3657       * @param basis the identity (initial default value) for the reduction
3658       * @param reducer a commutative associative combining function
3659       * @return the result of accumulating the given transformation
3660       * of all (key, value) pairs
3661 +     * @since 1.8
3662       */
3663 <    public long reduceToLongInParallel
3664 <        (ObjectByObjectToLong<? super K, ? super V> transformer,
3665 <         long basis,
3666 <         LongByLongToLong reducer) {
3667 <        return ForkJoinTasks.reduceToLong
3668 <            (this, transformer, basis, reducer).invoke();
3663 >    public long reduceToLong(long parallelismThreshold,
3664 >                             ObjectByObjectToLong<? super K, ? super V> transformer,
3665 >                             long basis,
3666 >                             LongByLongToLong reducer) {
3667 >        if (transformer == null || reducer == null)
3668 >            throw new NullPointerException();
3669 >        return new MapReduceMappingsToLongTask<K,V>
3670 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3671 >             null, transformer, basis, reducer).invoke();
3672      }
3673  
3674      /**
# Line 4150 | Line 3676 | public class ConcurrentHashMapV8<K, V>
3676       * of all (key, value) pairs using the given reducer to
3677       * combine values, and the given basis as an identity value.
3678       *
3679 +     * @param parallelismThreshold the (estimated) number of elements
3680 +     * needed for this operation to be executed in parallel
3681       * @param transformer a function returning the transformation
3682       * for an element
3683       * @param basis the identity (initial default value) for the reduction
3684       * @param reducer a commutative associative combining function
3685       * @return the result of accumulating the given transformation
3686       * of all (key, value) pairs
3687 +     * @since 1.8
3688       */
3689 <    public int reduceToIntInParallel
3690 <        (ObjectByObjectToInt<? super K, ? super V> transformer,
3691 <         int basis,
3692 <         IntByIntToInt reducer) {
3693 <        return ForkJoinTasks.reduceToInt
3694 <            (this, transformer, basis, reducer).invoke();
3689 >    public int reduceToInt(long parallelismThreshold,
3690 >                           ObjectByObjectToInt<? super K, ? super V> transformer,
3691 >                           int basis,
3692 >                           IntByIntToInt reducer) {
3693 >        if (transformer == null || reducer == null)
3694 >            throw new NullPointerException();
3695 >        return new MapReduceMappingsToIntTask<K,V>
3696 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3697 >             null, transformer, basis, reducer).invoke();
3698      }
3699  
3700      /**
3701       * Performs the given action for each key.
3702       *
3703 +     * @param parallelismThreshold the (estimated) number of elements
3704 +     * needed for this operation to be executed in parallel
3705       * @param action the action
3706 +     * @since 1.8
3707       */
3708 <    public void forEachKeyInParallel(Action<K> action) {
3709 <        ForkJoinTasks.forEachKey
3710 <            (this, action).invoke();
3708 >    public void forEachKey(long parallelismThreshold,
3709 >                           Action<? super K> action) {
3710 >        if (action == null) throw new NullPointerException();
3711 >        new ForEachKeyTask<K,V>
3712 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3713 >             action).invoke();
3714      }
3715  
3716      /**
3717       * Performs the given action for each non-null transformation
3718       * of each key.
3719       *
3720 +     * @param parallelismThreshold the (estimated) number of elements
3721 +     * needed for this operation to be executed in parallel
3722       * @param transformer a function returning the transformation
3723       * for an element, or null if there is no transformation (in
3724 <     * which case the action is not applied).
3724 >     * which case the action is not applied)
3725       * @param action the action
3726 +     * @since 1.8
3727       */
3728 <    public <U> void forEachKeyInParallel
3729 <        (Fun<? super K, ? extends U> transformer,
3730 <         Action<U> action) {
3731 <        ForkJoinTasks.forEachKey
3732 <            (this, transformer, action).invoke();
3728 >    public <U> void forEachKey(long parallelismThreshold,
3729 >                               Fun<? super K, ? extends U> transformer,
3730 >                               Action<? super U> action) {
3731 >        if (transformer == null || action == null)
3732 >            throw new NullPointerException();
3733 >        new ForEachTransformedKeyTask<K,V,U>
3734 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3735 >             transformer, action).invoke();
3736      }
3737  
3738      /**
# Line 4198 | Line 3742 | public class ConcurrentHashMapV8<K, V>
3742       * any other parallel invocations of the search function are
3743       * ignored.
3744       *
3745 +     * @param parallelismThreshold the (estimated) number of elements
3746 +     * needed for this operation to be executed in parallel
3747       * @param searchFunction a function returning a non-null
3748       * result on success, else null
3749       * @return a non-null result from applying the given search
3750       * function on each key, or null if none
3751 +     * @since 1.8
3752       */
3753 <    public <U> U searchKeysInParallel
3754 <        (Fun<? super K, ? extends U> searchFunction) {
3755 <        return ForkJoinTasks.searchKeys
3756 <            (this, searchFunction).invoke();
3753 >    public <U> U searchKeys(long parallelismThreshold,
3754 >                            Fun<? super K, ? extends U> searchFunction) {
3755 >        if (searchFunction == null) throw new NullPointerException();
3756 >        return new SearchKeysTask<K,V,U>
3757 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3758 >             searchFunction, new AtomicReference<U>()).invoke();
3759      }
3760  
3761      /**
3762       * Returns the result of accumulating all keys using the given
3763       * reducer to combine values, or null if none.
3764       *
3765 +     * @param parallelismThreshold the (estimated) number of elements
3766 +     * needed for this operation to be executed in parallel
3767       * @param reducer a commutative associative combining function
3768       * @return the result of accumulating all keys using the given
3769       * reducer to combine values, or null if none
3770 +     * @since 1.8
3771       */
3772 <    public K reduceKeysInParallel
3773 <        (BiFun<? super K, ? super K, ? extends K> reducer) {
3774 <        return ForkJoinTasks.reduceKeys
3775 <            (this, reducer).invoke();
3772 >    public K reduceKeys(long parallelismThreshold,
3773 >                        BiFun<? super K, ? super K, ? extends K> reducer) {
3774 >        if (reducer == null) throw new NullPointerException();
3775 >        return new ReduceKeysTask<K,V>
3776 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3777 >             null, reducer).invoke();
3778      }
3779  
3780      /**
# Line 4228 | Line 3782 | public class ConcurrentHashMapV8<K, V>
3782       * of all keys using the given reducer to combine values, or
3783       * null if none.
3784       *
3785 +     * @param parallelismThreshold the (estimated) number of elements
3786 +     * needed for this operation to be executed in parallel
3787       * @param transformer a function returning the transformation
3788       * for an element, or null if there is no transformation (in
3789 <     * which case it is not combined).
3789 >     * which case it is not combined)
3790       * @param reducer a commutative associative combining function
3791       * @return the result of accumulating the given transformation
3792       * of all keys
3793 +     * @since 1.8
3794       */
3795 <    public <U> U reduceKeysInParallel
3796 <        (Fun<? super K, ? extends U> transformer,
3795 >    public <U> U reduceKeys(long parallelismThreshold,
3796 >                            Fun<? super K, ? extends U> transformer,
3797           BiFun<? super U, ? super U, ? extends U> reducer) {
3798 <        return ForkJoinTasks.reduceKeys
3799 <            (this, transformer, reducer).invoke();
3798 >        if (transformer == null || reducer == null)
3799 >            throw new NullPointerException();
3800 >        return new MapReduceKeysTask<K,V,U>
3801 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3802 >             null, transformer, reducer).invoke();
3803      }
3804  
3805      /**
# Line 4247 | Line 3807 | public class ConcurrentHashMapV8<K, V>
3807       * of all keys using the given reducer to combine values, and
3808       * the given basis as an identity value.
3809       *
3810 +     * @param parallelismThreshold the (estimated) number of elements
3811 +     * needed for this operation to be executed in parallel
3812       * @param transformer a function returning the transformation
3813       * for an element
3814       * @param basis the identity (initial default value) for the reduction
3815       * @param reducer a commutative associative combining function
3816 <     * @return  the result of accumulating the given transformation
3816 >     * @return the result of accumulating the given transformation
3817       * of all keys
3818 +     * @since 1.8
3819       */
3820 <    public double reduceKeysToDoubleInParallel
3821 <        (ObjectToDouble<? super K> transformer,
3822 <         double basis,
3823 <         DoubleByDoubleToDouble reducer) {
3824 <        return ForkJoinTasks.reduceKeysToDouble
3825 <            (this, transformer, basis, reducer).invoke();
3820 >    public double reduceKeysToDouble(long parallelismThreshold,
3821 >                                     ObjectToDouble<? super K> transformer,
3822 >                                     double basis,
3823 >                                     DoubleByDoubleToDouble reducer) {
3824 >        if (transformer == null || reducer == null)
3825 >            throw new NullPointerException();
3826 >        return new MapReduceKeysToDoubleTask<K,V>
3827 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3828 >             null, transformer, basis, reducer).invoke();
3829      }
3830  
3831      /**
# Line 4267 | Line 3833 | public class ConcurrentHashMapV8<K, V>
3833       * of all keys using the given reducer to combine values, and
3834       * the given basis as an identity value.
3835       *
3836 +     * @param parallelismThreshold the (estimated) number of elements
3837 +     * needed for this operation to be executed in parallel
3838       * @param transformer a function returning the transformation
3839       * for an element
3840       * @param basis the identity (initial default value) for the reduction
3841       * @param reducer a commutative associative combining function
3842       * @return the result of accumulating the given transformation
3843       * of all keys
3844 +     * @since 1.8
3845       */
3846 <    public long reduceKeysToLongInParallel
3847 <        (ObjectToLong<? super K> transformer,
3848 <         long basis,
3849 <         LongByLongToLong reducer) {
3850 <        return ForkJoinTasks.reduceKeysToLong
3851 <            (this, transformer, basis, reducer).invoke();
3846 >    public long reduceKeysToLong(long parallelismThreshold,
3847 >                                 ObjectToLong<? super K> transformer,
3848 >                                 long basis,
3849 >                                 LongByLongToLong reducer) {
3850 >        if (transformer == null || reducer == null)
3851 >            throw new NullPointerException();
3852 >        return new MapReduceKeysToLongTask<K,V>
3853 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3854 >             null, transformer, basis, reducer).invoke();
3855      }
3856  
3857      /**
# Line 4287 | Line 3859 | public class ConcurrentHashMapV8<K, V>
3859       * of all keys using the given reducer to combine values, and
3860       * the given basis as an identity value.
3861       *
3862 +     * @param parallelismThreshold the (estimated) number of elements
3863 +     * needed for this operation to be executed in parallel
3864       * @param transformer a function returning the transformation
3865       * for an element
3866       * @param basis the identity (initial default value) for the reduction
3867       * @param reducer a commutative associative combining function
3868       * @return the result of accumulating the given transformation
3869       * of all keys
3870 +     * @since 1.8
3871       */
3872 <    public int reduceKeysToIntInParallel
3873 <        (ObjectToInt<? super K> transformer,
3874 <         int basis,
3875 <         IntByIntToInt reducer) {
3876 <        return ForkJoinTasks.reduceKeysToInt
3877 <            (this, transformer, basis, reducer).invoke();
3872 >    public int reduceKeysToInt(long parallelismThreshold,
3873 >                               ObjectToInt<? super K> transformer,
3874 >                               int basis,
3875 >                               IntByIntToInt reducer) {
3876 >        if (transformer == null || reducer == null)
3877 >            throw new NullPointerException();
3878 >        return new MapReduceKeysToIntTask<K,V>
3879 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3880 >             null, transformer, basis, reducer).invoke();
3881      }
3882  
3883      /**
3884       * Performs the given action for each value.
3885       *
3886 +     * @param parallelismThreshold the (estimated) number of elements
3887 +     * needed for this operation to be executed in parallel
3888       * @param action the action
3889 +     * @since 1.8
3890       */
3891 <    public void forEachValueInParallel(Action<V> action) {
3892 <        ForkJoinTasks.forEachValue
3893 <            (this, action).invoke();
3891 >    public void forEachValue(long parallelismThreshold,
3892 >                             Action<? super V> action) {
3893 >        if (action == null)
3894 >            throw new NullPointerException();
3895 >        new ForEachValueTask<K,V>
3896 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3897 >             action).invoke();
3898      }
3899  
3900      /**
3901       * Performs the given action for each non-null transformation
3902       * of each value.
3903       *
3904 +     * @param parallelismThreshold the (estimated) number of elements
3905 +     * needed for this operation to be executed in parallel
3906       * @param transformer a function returning the transformation
3907       * for an element, or null if there is no transformation (in
3908 <     * which case the action is not applied).
3908 >     * which case the action is not applied)
3909 >     * @param action the action
3910 >     * @since 1.8
3911       */
3912 <    public <U> void forEachValueInParallel
3913 <        (Fun<? super V, ? extends U> transformer,
3914 <         Action<U> action) {
3915 <        ForkJoinTasks.forEachValue
3916 <            (this, transformer, action).invoke();
3912 >    public <U> void forEachValue(long parallelismThreshold,
3913 >                                 Fun<? super V, ? extends U> transformer,
3914 >                                 Action<? super U> action) {
3915 >        if (transformer == null || action == null)
3916 >            throw new NullPointerException();
3917 >        new ForEachTransformedValueTask<K,V,U>
3918 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3919 >             transformer, action).invoke();
3920      }
3921  
3922      /**
# Line 4334 | Line 3926 | public class ConcurrentHashMapV8<K, V>
3926       * any other parallel invocations of the search function are
3927       * ignored.
3928       *
3929 +     * @param parallelismThreshold the (estimated) number of elements
3930 +     * needed for this operation to be executed in parallel
3931       * @param searchFunction a function returning a non-null
3932       * result on success, else null
3933       * @return a non-null result from applying the given search
3934       * function on each value, or null if none
3935 +     * @since 1.8
3936       */
3937 <    public <U> U searchValuesInParallel
3938 <        (Fun<? super V, ? extends U> searchFunction) {
3939 <        return ForkJoinTasks.searchValues
3940 <            (this, searchFunction).invoke();
3937 >    public <U> U searchValues(long parallelismThreshold,
3938 >                              Fun<? super V, ? extends U> searchFunction) {
3939 >        if (searchFunction == null) throw new NullPointerException();
3940 >        return new SearchValuesTask<K,V,U>
3941 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3942 >             searchFunction, new AtomicReference<U>()).invoke();
3943      }
3944  
3945      /**
3946       * Returns the result of accumulating all values using the
3947       * given reducer to combine values, or null if none.
3948       *
3949 +     * @param parallelismThreshold the (estimated) number of elements
3950 +     * needed for this operation to be executed in parallel
3951       * @param reducer a commutative associative combining function
3952 <     * @return  the result of accumulating all values
3952 >     * @return the result of accumulating all values
3953 >     * @since 1.8
3954       */
3955 <    public V reduceValuesInParallel
3956 <        (BiFun<? super V, ? super V, ? extends V> reducer) {
3957 <        return ForkJoinTasks.reduceValues
3958 <            (this, reducer).invoke();
3955 >    public V reduceValues(long parallelismThreshold,
3956 >                          BiFun<? super V, ? super V, ? extends V> reducer) {
3957 >        if (reducer == null) throw new NullPointerException();
3958 >        return new ReduceValuesTask<K,V>
3959 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3960 >             null, reducer).invoke();
3961      }
3962  
3963      /**
# Line 4363 | Line 3965 | public class ConcurrentHashMapV8<K, V>
3965       * of all values using the given reducer to combine values, or
3966       * null if none.
3967       *
3968 +     * @param parallelismThreshold the (estimated) number of elements
3969 +     * needed for this operation to be executed in parallel
3970       * @param transformer a function returning the transformation
3971       * for an element, or null if there is no transformation (in
3972 <     * which case it is not combined).
3972 >     * which case it is not combined)
3973       * @param reducer a commutative associative combining function
3974       * @return the result of accumulating the given transformation
3975       * of all values
3976 +     * @since 1.8
3977       */
3978 <    public <U> U reduceValuesInParallel
3979 <        (Fun<? super V, ? extends U> transformer,
3980 <         BiFun<? super U, ? super U, ? extends U> reducer) {
3981 <        return ForkJoinTasks.reduceValues
3982 <            (this, transformer, reducer).invoke();
3978 >    public <U> U reduceValues(long parallelismThreshold,
3979 >                              Fun<? super V, ? extends U> transformer,
3980 >                              BiFun<? super U, ? super U, ? extends U> reducer) {
3981 >        if (transformer == null || reducer == null)
3982 >            throw new NullPointerException();
3983 >        return new MapReduceValuesTask<K,V,U>
3984 >            (null, batchFor(parallelismThreshold), 0, 0, table,
3985 >             null, transformer, reducer).invoke();
3986      }
3987  
3988      /**
# Line 4382 | Line 3990 | public class ConcurrentHashMapV8<K, V>
3990       * of all values using the given reducer to combine values,
3991       * and the given basis as an identity value.
3992       *
3993 +     * @param parallelismThreshold the (estimated) number of elements
3994 +     * needed for this operation to be executed in parallel
3995       * @param transformer a function returning the transformation
3996       * for an element
3997       * @param basis the identity (initial default value) for the reduction
3998       * @param reducer a commutative associative combining function
3999       * @return the result of accumulating the given transformation
4000       * of all values
4001 +     * @since 1.8
4002       */
4003 <    public double reduceValuesToDoubleInParallel
4004 <        (ObjectToDouble<? super V> transformer,
4005 <         double basis,
4006 <         DoubleByDoubleToDouble reducer) {
4007 <        return ForkJoinTasks.reduceValuesToDouble
4008 <            (this, transformer, basis, reducer).invoke();
4003 >    public double reduceValuesToDouble(long parallelismThreshold,
4004 >                                       ObjectToDouble<? super V> transformer,
4005 >                                       double basis,
4006 >                                       DoubleByDoubleToDouble reducer) {
4007 >        if (transformer == null || reducer == null)
4008 >            throw new NullPointerException();
4009 >        return new MapReduceValuesToDoubleTask<K,V>
4010 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4011 >             null, transformer, basis, reducer).invoke();
4012      }
4013  
4014      /**
# Line 4402 | Line 4016 | public class ConcurrentHashMapV8<K, V>
4016       * of all values using the given reducer to combine values,
4017       * and the given basis as an identity value.
4018       *
4019 +     * @param parallelismThreshold the (estimated) number of elements
4020 +     * needed for this operation to be executed in parallel
4021       * @param transformer a function returning the transformation
4022       * for an element
4023       * @param basis the identity (initial default value) for the reduction
4024       * @param reducer a commutative associative combining function
4025       * @return the result of accumulating the given transformation
4026       * of all values
4027 +     * @since 1.8
4028       */
4029 <    public long reduceValuesToLongInParallel
4030 <        (ObjectToLong<? super V> transformer,
4031 <         long basis,
4032 <         LongByLongToLong reducer) {
4033 <        return ForkJoinTasks.reduceValuesToLong
4034 <            (this, transformer, basis, reducer).invoke();
4029 >    public long reduceValuesToLong(long parallelismThreshold,
4030 >                                   ObjectToLong<? super V> transformer,
4031 >                                   long basis,
4032 >                                   LongByLongToLong reducer) {
4033 >        if (transformer == null || reducer == null)
4034 >            throw new NullPointerException();
4035 >        return new MapReduceValuesToLongTask<K,V>
4036 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4037 >             null, transformer, basis, reducer).invoke();
4038      }
4039  
4040      /**
# Line 4422 | Line 4042 | public class ConcurrentHashMapV8<K, V>
4042       * of all values using the given reducer to combine values,
4043       * and the given basis as an identity value.
4044       *
4045 +     * @param parallelismThreshold the (estimated) number of elements
4046 +     * needed for this operation to be executed in parallel
4047       * @param transformer a function returning the transformation
4048       * for an element
4049       * @param basis the identity (initial default value) for the reduction
4050       * @param reducer a commutative associative combining function
4051       * @return the result of accumulating the given transformation
4052       * of all values
4053 +     * @since 1.8
4054       */
4055 <    public int reduceValuesToIntInParallel
4056 <        (ObjectToInt<? super V> transformer,
4057 <         int basis,
4058 <         IntByIntToInt reducer) {
4059 <        return ForkJoinTasks.reduceValuesToInt
4060 <            (this, transformer, basis, reducer).invoke();
4055 >    public int reduceValuesToInt(long parallelismThreshold,
4056 >                                 ObjectToInt<? super V> transformer,
4057 >                                 int basis,
4058 >                                 IntByIntToInt reducer) {
4059 >        if (transformer == null || reducer == null)
4060 >            throw new NullPointerException();
4061 >        return new MapReduceValuesToIntTask<K,V>
4062 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4063 >             null, transformer, basis, reducer).invoke();
4064      }
4065  
4066      /**
4067       * Performs the given action for each entry.
4068       *
4069 +     * @param parallelismThreshold the (estimated) number of elements
4070 +     * needed for this operation to be executed in parallel
4071       * @param action the action
4072 +     * @since 1.8
4073       */
4074 <    public void forEachEntryInParallel(Action<Map.Entry<K,V>> action) {
4075 <        ForkJoinTasks.forEachEntry
4076 <            (this, action).invoke();
4074 >    public void forEachEntry(long parallelismThreshold,
4075 >                             Action<? super Map.Entry<K,V>> action) {
4076 >        if (action == null) throw new NullPointerException();
4077 >        new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4078 >                                  action).invoke();
4079      }
4080  
4081      /**
4082       * Performs the given action for each non-null transformation
4083       * of each entry.
4084       *
4085 +     * @param parallelismThreshold the (estimated) number of elements
4086 +     * needed for this operation to be executed in parallel
4087       * @param transformer a function returning the transformation
4088       * for an element, or null if there is no transformation (in
4089 <     * which case the action is not applied).
4089 >     * which case the action is not applied)
4090       * @param action the action
4091 +     * @since 1.8
4092       */
4093 <    public <U> void forEachEntryInParallel
4094 <        (Fun<Map.Entry<K,V>, ? extends U> transformer,
4095 <         Action<U> action) {
4096 <        ForkJoinTasks.forEachEntry
4097 <            (this, transformer, action).invoke();
4093 >    public <U> void forEachEntry(long parallelismThreshold,
4094 >                                 Fun<Map.Entry<K,V>, ? extends U> transformer,
4095 >                                 Action<? super U> action) {
4096 >        if (transformer == null || action == null)
4097 >            throw new NullPointerException();
4098 >        new ForEachTransformedEntryTask<K,V,U>
4099 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4100 >             transformer, action).invoke();
4101      }
4102  
4103      /**
# Line 4470 | Line 4107 | public class ConcurrentHashMapV8<K, V>
4107       * any other parallel invocations of the search function are
4108       * ignored.
4109       *
4110 +     * @param parallelismThreshold the (estimated) number of elements
4111 +     * needed for this operation to be executed in parallel
4112       * @param searchFunction a function returning a non-null
4113       * result on success, else null
4114       * @return a non-null result from applying the given search
4115       * function on each entry, or null if none
4116 +     * @since 1.8
4117       */
4118 <    public <U> U searchEntriesInParallel
4119 <        (Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4120 <        return ForkJoinTasks.searchEntries
4121 <            (this, searchFunction).invoke();
4118 >    public <U> U searchEntries(long parallelismThreshold,
4119 >                               Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4120 >        if (searchFunction == null) throw new NullPointerException();
4121 >        return new SearchEntriesTask<K,V,U>
4122 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4123 >             searchFunction, new AtomicReference<U>()).invoke();
4124      }
4125  
4126      /**
4127       * Returns the result of accumulating all entries using the
4128       * given reducer to combine values, or null if none.
4129       *
4130 +     * @param parallelismThreshold the (estimated) number of elements
4131 +     * needed for this operation to be executed in parallel
4132       * @param reducer a commutative associative combining function
4133       * @return the result of accumulating all entries
4134 +     * @since 1.8
4135       */
4136 <    public Map.Entry<K,V> reduceEntriesInParallel
4137 <        (BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4138 <        return ForkJoinTasks.reduceEntries
4139 <            (this, reducer).invoke();
4136 >    public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4137 >                                        BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4138 >        if (reducer == null) throw new NullPointerException();
4139 >        return new ReduceEntriesTask<K,V>
4140 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4141 >             null, reducer).invoke();
4142      }
4143  
4144      /**
# Line 4499 | Line 4146 | public class ConcurrentHashMapV8<K, V>
4146       * of all entries using the given reducer to combine values,
4147       * or null if none.
4148       *
4149 +     * @param parallelismThreshold the (estimated) number of elements
4150 +     * needed for this operation to be executed in parallel
4151       * @param transformer a function returning the transformation
4152       * for an element, or null if there is no transformation (in
4153 <     * which case it is not combined).
4153 >     * which case it is not combined)
4154       * @param reducer a commutative associative combining function
4155       * @return the result of accumulating the given transformation
4156       * of all entries
4157 +     * @since 1.8
4158       */
4159 <    public <U> U reduceEntriesInParallel
4160 <        (Fun<Map.Entry<K,V>, ? extends U> transformer,
4161 <         BiFun<? super U, ? super U, ? extends U> reducer) {
4162 <        return ForkJoinTasks.reduceEntries
4163 <            (this, transformer, reducer).invoke();
4159 >    public <U> U reduceEntries(long parallelismThreshold,
4160 >                               Fun<Map.Entry<K,V>, ? extends U> transformer,
4161 >                               BiFun<? super U, ? super U, ? extends U> reducer) {
4162 >        if (transformer == null || reducer == null)
4163 >            throw new NullPointerException();
4164 >        return new MapReduceEntriesTask<K,V,U>
4165 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4166 >             null, transformer, reducer).invoke();
4167      }
4168  
4169      /**
# Line 4518 | Line 4171 | public class ConcurrentHashMapV8<K, V>
4171       * of all entries using the given reducer to combine values,
4172       * and the given basis as an identity value.
4173       *
4174 +     * @param parallelismThreshold the (estimated) number of elements
4175 +     * needed for this operation to be executed in parallel
4176       * @param transformer a function returning the transformation
4177       * for an element
4178       * @param basis the identity (initial default value) for the reduction
4179       * @param reducer a commutative associative combining function
4180       * @return the result of accumulating the given transformation
4181       * of all entries
4182 +     * @since 1.8
4183       */
4184 <    public double reduceEntriesToDoubleInParallel
4185 <        (ObjectToDouble<Map.Entry<K,V>> transformer,
4186 <         double basis,
4187 <         DoubleByDoubleToDouble reducer) {
4188 <        return ForkJoinTasks.reduceEntriesToDouble
4189 <            (this, transformer, basis, reducer).invoke();
4184 >    public double reduceEntriesToDouble(long parallelismThreshold,
4185 >                                        ObjectToDouble<Map.Entry<K,V>> transformer,
4186 >                                        double basis,
4187 >                                        DoubleByDoubleToDouble reducer) {
4188 >        if (transformer == null || reducer == null)
4189 >            throw new NullPointerException();
4190 >        return new MapReduceEntriesToDoubleTask<K,V>
4191 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4192 >             null, transformer, basis, reducer).invoke();
4193      }
4194  
4195      /**
# Line 4538 | Line 4197 | public class ConcurrentHashMapV8<K, V>
4197       * of all entries using the given reducer to combine values,
4198       * and the given basis as an identity value.
4199       *
4200 +     * @param parallelismThreshold the (estimated) number of elements
4201 +     * needed for this operation to be executed in parallel
4202       * @param transformer a function returning the transformation
4203       * for an element
4204       * @param basis the identity (initial default value) for the reduction
4205       * @param reducer a commutative associative combining function
4206 <     * @return  the result of accumulating the given transformation
4206 >     * @return the result of accumulating the given transformation
4207       * of all entries
4208 +     * @since 1.8
4209       */
4210 <    public long reduceEntriesToLongInParallel
4211 <        (ObjectToLong<Map.Entry<K,V>> transformer,
4212 <         long basis,
4213 <         LongByLongToLong reducer) {
4214 <        return ForkJoinTasks.reduceEntriesToLong
4215 <            (this, transformer, basis, reducer).invoke();
4210 >    public long reduceEntriesToLong(long parallelismThreshold,
4211 >                                    ObjectToLong<Map.Entry<K,V>> transformer,
4212 >                                    long basis,
4213 >                                    LongByLongToLong reducer) {
4214 >        if (transformer == null || reducer == null)
4215 >            throw new NullPointerException();
4216 >        return new MapReduceEntriesToLongTask<K,V>
4217 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4218 >             null, transformer, basis, reducer).invoke();
4219      }
4220  
4221      /**
# Line 4558 | Line 4223 | public class ConcurrentHashMapV8<K, V>
4223       * of all entries using the given reducer to combine values,
4224       * and the given basis as an identity value.
4225       *
4226 +     * @param parallelismThreshold the (estimated) number of elements
4227 +     * needed for this operation to be executed in parallel
4228       * @param transformer a function returning the transformation
4229       * for an element
4230       * @param basis the identity (initial default value) for the reduction
4231       * @param reducer a commutative associative combining function
4232       * @return the result of accumulating the given transformation
4233       * of all entries
4234 +     * @since 1.8
4235       */
4236 <    public int reduceEntriesToIntInParallel
4237 <        (ObjectToInt<Map.Entry<K,V>> transformer,
4238 <         int basis,
4239 <         IntByIntToInt reducer) {
4240 <        return ForkJoinTasks.reduceEntriesToInt
4241 <            (this, transformer, basis, reducer).invoke();
4236 >    public int reduceEntriesToInt(long parallelismThreshold,
4237 >                                  ObjectToInt<Map.Entry<K,V>> transformer,
4238 >                                  int basis,
4239 >                                  IntByIntToInt reducer) {
4240 >        if (transformer == null || reducer == null)
4241 >            throw new NullPointerException();
4242 >        return new MapReduceEntriesToIntTask<K,V>
4243 >            (null, batchFor(parallelismThreshold), 0, 0, table,
4244 >             null, transformer, basis, reducer).invoke();
4245      }
4246  
4247  
# Line 4579 | Line 4250 | public class ConcurrentHashMapV8<K, V>
4250      /**
4251       * Base class for views.
4252       */
4253 <    abstract static class CHMView<K, V> {
4254 <        final ConcurrentHashMapV8<K, V> map;
4255 <        CHMView(ConcurrentHashMapV8<K, V> map)  { this.map = map; }
4253 >    abstract static class CollectionView<K,V,E>
4254 >        implements Collection<E>, java.io.Serializable {
4255 >        private static final long serialVersionUID = 7249069246763182397L;
4256 >        final ConcurrentHashMapV8<K,V> map;
4257 >        CollectionView(ConcurrentHashMapV8<K,V> map)  { this.map = map; }
4258  
4259          /**
4260           * Returns the map backing this view.
# Line 4590 | Line 4263 | public class ConcurrentHashMapV8<K, V>
4263           */
4264          public ConcurrentHashMapV8<K,V> getMap() { return map; }
4265  
4266 <        public final int size()                 { return map.size(); }
4267 <        public final boolean isEmpty()          { return map.isEmpty(); }
4268 <        public final void clear()               { map.clear(); }
4266 >        /**
4267 >         * Removes all of the elements from this view, by removing all
4268 >         * the mappings from the map backing this view.
4269 >         */
4270 >        public final void clear()      { map.clear(); }
4271 >        public final int size()        { return map.size(); }
4272 >        public final boolean isEmpty() { return map.isEmpty(); }
4273  
4274          // implementations below rely on concrete classes supplying these
4275 <        public abstract Iterator<?> iterator();
4275 >        // abstract methods
4276 >        /**
4277 >         * Returns a "weakly consistent" iterator that will never
4278 >         * throw {@link ConcurrentModificationException}, and
4279 >         * guarantees to traverse elements as they existed upon
4280 >         * construction of the iterator, and may (but is not
4281 >         * guaranteed to) reflect any modifications subsequent to
4282 >         * construction.
4283 >         */
4284 >        public abstract Iterator<E> iterator();
4285          public abstract boolean contains(Object o);
4286          public abstract boolean remove(Object o);
4287  
# Line 4603 | Line 4289 | public class ConcurrentHashMapV8<K, V>
4289  
4290          public final Object[] toArray() {
4291              long sz = map.mappingCount();
4292 <            if (sz > (long)(MAX_ARRAY_SIZE))
4292 >            if (sz > MAX_ARRAY_SIZE)
4293                  throw new OutOfMemoryError(oomeMsg);
4294              int n = (int)sz;
4295              Object[] r = new Object[n];
4296              int i = 0;
4297 <            Iterator<?> it = iterator();
4612 <            while (it.hasNext()) {
4297 >            for (E e : this) {
4298                  if (i == n) {
4299                      if (n >= MAX_ARRAY_SIZE)
4300                          throw new OutOfMemoryError(oomeMsg);
# Line 4619 | Line 4304 | public class ConcurrentHashMapV8<K, V>
4304                          n += (n >>> 1) + 1;
4305                      r = Arrays.copyOf(r, n);
4306                  }
4307 <                r[i++] = it.next();
4307 >                r[i++] = e;
4308              }
4309              return (i == n) ? r : Arrays.copyOf(r, i);
4310          }
4311  
4312 <        @SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4312 >        @SuppressWarnings("unchecked")
4313 >        public final <T> T[] toArray(T[] a) {
4314              long sz = map.mappingCount();
4315 <            if (sz > (long)(MAX_ARRAY_SIZE))
4315 >            if (sz > MAX_ARRAY_SIZE)
4316                  throw new OutOfMemoryError(oomeMsg);
4317              int m = (int)sz;
4318              T[] r = (a.length >= m) ? a :
# Line 4634 | Line 4320 | public class ConcurrentHashMapV8<K, V>
4320                  .newInstance(a.getClass().getComponentType(), m);
4321              int n = r.length;
4322              int i = 0;
4323 <            Iterator<?> it = iterator();
4638 <            while (it.hasNext()) {
4323 >            for (E e : this) {
4324                  if (i == n) {
4325                      if (n >= MAX_ARRAY_SIZE)
4326                          throw new OutOfMemoryError(oomeMsg);
# Line 4645 | Line 4330 | public class ConcurrentHashMapV8<K, V>
4330                          n += (n >>> 1) + 1;
4331                      r = Arrays.copyOf(r, n);
4332                  }
4333 <                r[i++] = (T)it.next();
4333 >                r[i++] = (T)e;
4334              }
4335              if (a == r && i < n) {
4336                  r[i] = null; // null-terminate
# Line 4654 | Line 4339 | public class ConcurrentHashMapV8<K, V>
4339              return (i == n) ? r : Arrays.copyOf(r, i);
4340          }
4341  
4342 <        public final int hashCode() {
4343 <            int h = 0;
4344 <            for (Iterator<?> it = iterator(); it.hasNext();)
4345 <                h += it.next().hashCode();
4346 <            return h;
4347 <        }
4348 <
4342 >        /**
4343 >         * Returns a string representation of this collection.
4344 >         * The string representation consists of the string representations
4345 >         * of the collection's elements in the order they are returned by
4346 >         * its iterator, enclosed in square brackets ({@code "[]"}).
4347 >         * Adjacent elements are separated by the characters {@code ", "}
4348 >         * (comma and space).  Elements are converted to strings as by
4349 >         * {@link String#valueOf(Object)}.
4350 >         *
4351 >         * @return a string representation of this collection
4352 >         */
4353          public final String toString() {
4354              StringBuilder sb = new StringBuilder();
4355              sb.append('[');
4356 <            Iterator<?> it = iterator();
4356 >            Iterator<E> it = iterator();
4357              if (it.hasNext()) {
4358                  for (;;) {
4359                      Object e = it.next();
# Line 4679 | Line 4368 | public class ConcurrentHashMapV8<K, V>
4368  
4369          public final boolean containsAll(Collection<?> c) {
4370              if (c != this) {
4371 <                for (Iterator<?> it = c.iterator(); it.hasNext();) {
4683 <                    Object e = it.next();
4371 >                for (Object e : c) {
4372                      if (e == null || !contains(e))
4373                          return false;
4374                  }
# Line 4690 | Line 4378 | public class ConcurrentHashMapV8<K, V>
4378  
4379          public final boolean removeAll(Collection<?> c) {
4380              boolean modified = false;
4381 <            for (Iterator<?> it = iterator(); it.hasNext();) {
4381 >            for (Iterator<E> it = iterator(); it.hasNext();) {
4382                  if (c.contains(it.next())) {
4383                      it.remove();
4384                      modified = true;
# Line 4701 | Line 4389 | public class ConcurrentHashMapV8<K, V>
4389  
4390          public final boolean retainAll(Collection<?> c) {
4391              boolean modified = false;
4392 <            for (Iterator<?> it = iterator(); it.hasNext();) {
4392 >            for (Iterator<E> it = iterator(); it.hasNext();) {
4393                  if (!c.contains(it.next())) {
4394                      it.remove();
4395                      modified = true;
# Line 4715 | Line 4403 | public class ConcurrentHashMapV8<K, V>
4403      /**
4404       * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in
4405       * which additions may optionally be enabled by mapping to a
4406 <     * common value.  This class cannot be directly instantiated. See
4407 <     * {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4408 <     * {@link #newKeySet(int)}.
4406 >     * common value.  This class cannot be directly instantiated.
4407 >     * See {@link #keySet() keySet()},
4408 >     * {@link #keySet(Object) keySet(V)},
4409 >     * {@link #newKeySet() newKeySet()},
4410 >     * {@link #newKeySet(int) newKeySet(int)}.
4411 >     *
4412 >     * @since 1.8
4413       */
4414 <    public static class KeySetView<K,V> extends CHMView<K,V>
4414 >    public static class KeySetView<K,V> extends CollectionView<K,V,K>
4415          implements Set<K>, java.io.Serializable {
4416          private static final long serialVersionUID = 7249069246763182397L;
4417          private final V value;
4418 <        KeySetView(ConcurrentHashMapV8<K, V> map, V value) {  // non-public
4418 >        KeySetView(ConcurrentHashMapV8<K,V> map, V value) {  // non-public
4419              super(map);
4420              this.value = value;
4421          }
# Line 4733 | Line 4425 | public class ConcurrentHashMapV8<K, V>
4425           * or {@code null} if additions are not supported.
4426           *
4427           * @return the default mapped value for additions, or {@code null}
4428 <         * if not supported.
4428 >         * if not supported
4429           */
4430          public V getMappedValue() { return value; }
4431  
4432 <        // implement Set API
4433 <
4432 >        /**
4433 >         * {@inheritDoc}
4434 >         * @throws NullPointerException if the specified key is null
4435 >         */
4436          public boolean contains(Object o) { return map.containsKey(o); }
4743        public boolean remove(Object o)   { return map.remove(o) != null; }
4437  
4438          /**
4439 <         * Returns a "weakly consistent" iterator that will never
4440 <         * throw {@link ConcurrentModificationException}, and
4441 <         * guarantees to traverse elements as they existed upon
4749 <         * construction of the iterator, and may (but is not
4750 <         * guaranteed to) reflect any modifications subsequent to
4751 <         * construction.
4439 >         * Removes the key from this map view, by removing the key (and its
4440 >         * corresponding value) from the backing map.  This method does
4441 >         * nothing if the key is not in the map.
4442           *
4443 <         * @return an iterator over the keys of this map
4443 >         * @param  o the key to be removed from the backing map
4444 >         * @return {@code true} if the backing map contained the specified key
4445 >         * @throws NullPointerException if the specified key is null
4446 >         */
4447 >        public boolean remove(Object o) { return map.remove(o) != null; }
4448 >
4449 >        /**
4450 >         * @return an iterator over the keys of the backing map
4451 >         */
4452 >        public Iterator<K> iterator() {
4453 >            Node<K,V>[] t;
4454 >            ConcurrentHashMapV8<K,V> m = map;
4455 >            int f = (t = m.table) == null ? 0 : t.length;
4456 >            return new KeyIterator<K,V>(t, f, 0, f, m);
4457 >        }
4458 >
4459 >        /**
4460 >         * Adds the specified key to this set view by mapping the key to
4461 >         * the default mapped value in the backing map, if defined.
4462 >         *
4463 >         * @param e key to be added
4464 >         * @return {@code true} if this set changed as a result of the call
4465 >         * @throws NullPointerException if the specified key is null
4466 >         * @throws UnsupportedOperationException if no default mapped value
4467 >         * for additions was provided
4468           */
4755        public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4469          public boolean add(K e) {
4470              V v;
4471              if ((v = value) == null)
4472                  throw new UnsupportedOperationException();
4473 <            if (e == null)
4761 <                throw new NullPointerException();
4762 <            return map.internalPut(e, v, true) == null;
4473 >            return map.putVal(e, v, true) == null;
4474          }
4475 +
4476 +        /**
4477 +         * Adds all of the elements in the specified collection to this set,
4478 +         * as if by calling {@link #add} on each one.
4479 +         *
4480 +         * @param c the elements to be inserted into this set
4481 +         * @return {@code true} if this set changed as a result of the call
4482 +         * @throws NullPointerException if the collection or any of its
4483 +         * elements are {@code null}
4484 +         * @throws UnsupportedOperationException if no default mapped value
4485 +         * for additions was provided
4486 +         */
4487          public boolean addAll(Collection<? extends K> c) {
4488              boolean added = false;
4489              V v;
4490              if ((v = value) == null)
4491                  throw new UnsupportedOperationException();
4492              for (K e : c) {
4493 <                if (e == null)
4771 <                    throw new NullPointerException();
4772 <                if (map.internalPut(e, v, true) == null)
4493 >                if (map.putVal(e, v, true) == null)
4494                      added = true;
4495              }
4496              return added;
4497          }
4498 +
4499 +        public int hashCode() {
4500 +            int h = 0;
4501 +            for (K e : this)
4502 +                h += e.hashCode();
4503 +            return h;
4504 +        }
4505 +
4506          public boolean equals(Object o) {
4507              Set<?> c;
4508              return ((o instanceof Set) &&
4509                      ((c = (Set<?>)o) == this ||
4510                       (containsAll(c) && c.containsAll(this))));
4511          }
4512 +
4513 +        public ConcurrentHashMapSpliterator<K> spliterator() {
4514 +            Node<K,V>[] t;
4515 +            ConcurrentHashMapV8<K,V> m = map;
4516 +            long n = m.sumCount();
4517 +            int f = (t = m.table) == null ? 0 : t.length;
4518 +            return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4519 +        }
4520 +
4521 +        public void forEach(Action<? super K> action) {
4522 +            if (action == null) throw new NullPointerException();
4523 +            Node<K,V>[] t;
4524 +            if ((t = map.table) != null) {
4525 +                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4526 +                for (Node<K,V> p; (p = it.advance()) != null; )
4527 +                    action.apply(p.key);
4528 +            }
4529 +        }
4530      }
4531  
4532      /**
4533       * A view of a ConcurrentHashMapV8 as a {@link Collection} of
4534       * values, in which additions are disabled. This class cannot be
4535 <     * directly instantiated. See {@link #values},
4789 <     *
4790 <     * <p>The view's {@code iterator} is a "weakly consistent" iterator
4791 <     * that will never throw {@link ConcurrentModificationException},
4792 <     * and guarantees to traverse elements as they existed upon
4793 <     * construction of the iterator, and may (but is not guaranteed to)
4794 <     * reflect any modifications subsequent to construction.
4535 >     * directly instantiated. See {@link #values()}.
4536       */
4537 <    public static final class ValuesView<K,V> extends CHMView<K,V>
4538 <        implements Collection<V> {
4539 <        ValuesView(ConcurrentHashMapV8<K, V> map)   { super(map); }
4540 <        public final boolean contains(Object o) { return map.containsValue(o); }
4537 >    static final class ValuesView<K,V> extends CollectionView<K,V,V>
4538 >        implements Collection<V>, java.io.Serializable {
4539 >        private static final long serialVersionUID = 2249069246763182397L;
4540 >        ValuesView(ConcurrentHashMapV8<K,V> map) { super(map); }
4541 >        public final boolean contains(Object o) {
4542 >            return map.containsValue(o);
4543 >        }
4544 >
4545          public final boolean remove(Object o) {
4546              if (o != null) {
4547 <                Iterator<V> it = new ValueIterator<K,V>(map);
4803 <                while (it.hasNext()) {
4547 >                for (Iterator<V> it = iterator(); it.hasNext();) {
4548                      if (o.equals(it.next())) {
4549                          it.remove();
4550                          return true;
# Line 4810 | Line 4554 | public class ConcurrentHashMapV8<K, V>
4554              return false;
4555          }
4556  
4813        /**
4814         * Returns a "weakly consistent" iterator that will never
4815         * throw {@link ConcurrentModificationException}, and
4816         * guarantees to traverse elements as they existed upon
4817         * construction of the iterator, and may (but is not
4818         * guaranteed to) reflect any modifications subsequent to
4819         * construction.
4820         *
4821         * @return an iterator over the values of this map
4822         */
4557          public final Iterator<V> iterator() {
4558 <            return new ValueIterator<K,V>(map);
4558 >            ConcurrentHashMapV8<K,V> m = map;
4559 >            Node<K,V>[] t;
4560 >            int f = (t = m.table) == null ? 0 : t.length;
4561 >            return new ValueIterator<K,V>(t, f, 0, f, m);
4562          }
4563 +
4564          public final boolean add(V e) {
4565              throw new UnsupportedOperationException();
4566          }
# Line 4830 | Line 4568 | public class ConcurrentHashMapV8<K, V>
4568              throw new UnsupportedOperationException();
4569          }
4570  
4571 +        public ConcurrentHashMapSpliterator<V> spliterator() {
4572 +            Node<K,V>[] t;
4573 +            ConcurrentHashMapV8<K,V> m = map;
4574 +            long n = m.sumCount();
4575 +            int f = (t = m.table) == null ? 0 : t.length;
4576 +            return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4577 +        }
4578 +
4579 +        public void forEach(Action<? super V> action) {
4580 +            if (action == null) throw new NullPointerException();
4581 +            Node<K,V>[] t;
4582 +            if ((t = map.table) != null) {
4583 +                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4584 +                for (Node<K,V> p; (p = it.advance()) != null; )
4585 +                    action.apply(p.val);
4586 +            }
4587 +        }
4588      }
4589  
4590      /**
4591       * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value)
4592       * entries.  This class cannot be directly instantiated. See
4593 <     * {@link #entrySet}.
4593 >     * {@link #entrySet()}.
4594       */
4595 <    public static final class EntrySetView<K,V> extends CHMView<K,V>
4596 <        implements Set<Map.Entry<K,V>> {
4597 <        EntrySetView(ConcurrentHashMapV8<K, V> map) { super(map); }
4598 <        public final boolean contains(Object o) {
4595 >    static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4596 >        implements Set<Map.Entry<K,V>>, java.io.Serializable {
4597 >        private static final long serialVersionUID = 2249069246763182397L;
4598 >        EntrySetView(ConcurrentHashMapV8<K,V> map) { super(map); }
4599 >
4600 >        public boolean contains(Object o) {
4601              Object k, v, r; Map.Entry<?,?> e;
4602              return ((o instanceof Map.Entry) &&
4603                      (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
# Line 4848 | Line 4605 | public class ConcurrentHashMapV8<K, V>
4605                      (v = e.getValue()) != null &&
4606                      (v == r || v.equals(r)));
4607          }
4608 <        public final boolean remove(Object o) {
4608 >
4609 >        public boolean remove(Object o) {
4610              Object k, v; Map.Entry<?,?> e;
4611              return ((o instanceof Map.Entry) &&
4612                      (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
# Line 4857 | Line 4615 | public class ConcurrentHashMapV8<K, V>
4615          }
4616  
4617          /**
4618 <         * Returns a "weakly consistent" iterator that will never
4861 <         * throw {@link ConcurrentModificationException}, and
4862 <         * guarantees to traverse elements as they existed upon
4863 <         * construction of the iterator, and may (but is not
4864 <         * guaranteed to) reflect any modifications subsequent to
4865 <         * construction.
4866 <         *
4867 <         * @return an iterator over the entries of this map
4618 >         * @return an iterator over the entries of the backing map
4619           */
4620 <        public final Iterator<Map.Entry<K,V>> iterator() {
4621 <            return new EntryIterator<K,V>(map);
4620 >        public Iterator<Map.Entry<K,V>> iterator() {
4621 >            ConcurrentHashMapV8<K,V> m = map;
4622 >            Node<K,V>[] t;
4623 >            int f = (t = m.table) == null ? 0 : t.length;
4624 >            return new EntryIterator<K,V>(t, f, 0, f, m);
4625          }
4626  
4627 <        public final boolean add(Entry<K,V> e) {
4628 <            K key = e.getKey();
4875 <            V value = e.getValue();
4876 <            if (key == null || value == null)
4877 <                throw new NullPointerException();
4878 <            return map.internalPut(key, value, false) == null;
4627 >        public boolean add(Entry<K,V> e) {
4628 >            return map.putVal(e.getKey(), e.getValue(), false) == null;
4629          }
4630 <        public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4630 >
4631 >        public boolean addAll(Collection<? extends Entry<K,V>> c) {
4632              boolean added = false;
4633              for (Entry<K,V> e : c) {
4634                  if (add(e))
# Line 4885 | Line 4636 | public class ConcurrentHashMapV8<K, V>
4636              }
4637              return added;
4638          }
4639 <        public boolean equals(Object o) {
4639 >
4640 >        public final int hashCode() {
4641 >            int h = 0;
4642 >            Node<K,V>[] t;
4643 >            if ((t = map.table) != null) {
4644 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4645 >                for (Node<K,V> p; (p = it.advance()) != null; ) {
4646 >                    h += p.hashCode();
4647 >                }
4648 >            }
4649 >            return h;
4650 >        }
4651 >
4652 >        public final boolean equals(Object o) {
4653              Set<?> c;
4654              return ((o instanceof Set) &&
4655                      ((c = (Set<?>)o) == this ||
4656                       (containsAll(c) && c.containsAll(this))));
4657          }
4894    }
4895
4896    // ---------------------------------------------------------------------
4897
4898    /**
4899     * Predefined tasks for performing bulk parallel operations on
4900     * ConcurrentHashMapV8s. These tasks follow the forms and rules used
4901     * for bulk operations. Each method has the same name, but returns
4902     * a task rather than invoking it. These methods may be useful in
4903     * custom applications such as submitting a task without waiting
4904     * for completion, using a custom pool, or combining with other
4905     * tasks.
4906     */
4907    public static class ForkJoinTasks {
4908        private ForkJoinTasks() {}
4909
4910        /**
4911         * Returns a task that when invoked, performs the given
4912         * action for each (key, value)
4913         *
4914         * @param map the map
4915         * @param action the action
4916         * @return the task
4917         */
4918        public static <K,V> ForkJoinTask<Void> forEach
4919            (ConcurrentHashMapV8<K,V> map,
4920             BiAction<K,V> action) {
4921            if (action == null) throw new NullPointerException();
4922            return new ForEachMappingTask<K,V>(map, null, -1, action);
4923        }
4924
4925        /**
4926         * Returns a task that when invoked, performs the given
4927         * action for each non-null transformation of each (key, value)
4928         *
4929         * @param map the map
4930         * @param transformer a function returning the transformation
4931         * for an element, or null if there is no transformation (in
4932         * which case the action is not applied)
4933         * @param action the action
4934         * @return the task
4935         */
4936        public static <K,V,U> ForkJoinTask<Void> forEach
4937            (ConcurrentHashMapV8<K,V> map,
4938             BiFun<? super K, ? super V, ? extends U> transformer,
4939             Action<U> action) {
4940            if (transformer == null || action == null)
4941                throw new NullPointerException();
4942            return new ForEachTransformedMappingTask<K,V,U>
4943                (map, null, -1, transformer, action);
4944        }
4945
4946        /**
4947         * Returns a task that when invoked, returns a non-null result
4948         * from applying the given search function on each (key,
4949         * value), or null if none. Upon success, further element
4950         * processing is suppressed and the results of any other
4951         * parallel invocations of the search function are ignored.
4952         *
4953         * @param map the map
4954         * @param searchFunction a function returning a non-null
4955         * result on success, else null
4956         * @return the task
4957         */
4958        public static <K,V,U> ForkJoinTask<U> search
4959            (ConcurrentHashMapV8<K,V> map,
4960             BiFun<? super K, ? super V, ? extends U> searchFunction) {
4961            if (searchFunction == null) throw new NullPointerException();
4962            return new SearchMappingsTask<K,V,U>
4963                (map, null, -1, searchFunction,
4964                 new AtomicReference<U>());
4965        }
4966
4967        /**
4968         * Returns a task that when invoked, returns the result of
4969         * accumulating the given transformation of all (key, value) pairs
4970         * using the given reducer to combine values, or null if none.
4971         *
4972         * @param map the map
4973         * @param transformer a function returning the transformation
4974         * for an element, or null if there is no transformation (in
4975         * which case it is not combined).
4976         * @param reducer a commutative associative combining function
4977         * @return the task
4978         */
4979        public static <K,V,U> ForkJoinTask<U> reduce
4980            (ConcurrentHashMapV8<K,V> map,
4981             BiFun<? super K, ? super V, ? extends U> transformer,
4982             BiFun<? super U, ? super U, ? extends U> reducer) {
4983            if (transformer == null || reducer == null)
4984                throw new NullPointerException();
4985            return new MapReduceMappingsTask<K,V,U>
4986                (map, null, -1, null, transformer, reducer);
4987        }
4988
4989        /**
4990         * Returns a task that when invoked, returns the result of
4991         * accumulating the given transformation of all (key, value) pairs
4992         * using the given reducer to combine values, and the given
4993         * basis as an identity value.
4994         *
4995         * @param map the map
4996         * @param transformer a function returning the transformation
4997         * for an element
4998         * @param basis the identity (initial default value) for the reduction
4999         * @param reducer a commutative associative combining function
5000         * @return the task
5001         */
5002        public static <K,V> ForkJoinTask<Double> reduceToDouble
5003            (ConcurrentHashMapV8<K,V> map,
5004             ObjectByObjectToDouble<? super K, ? super V> transformer,
5005             double basis,
5006             DoubleByDoubleToDouble reducer) {
5007            if (transformer == null || reducer == null)
5008                throw new NullPointerException();
5009            return new MapReduceMappingsToDoubleTask<K,V>
5010                (map, null, -1, null, transformer, basis, reducer);
5011        }
5012
5013        /**
5014         * Returns a task that when invoked, returns the result of
5015         * accumulating the given transformation of all (key, value) pairs
5016         * using the given reducer to combine values, and the given
5017         * basis as an identity value.
5018         *
5019         * @param map the map
5020         * @param transformer a function returning the transformation
5021         * for an element
5022         * @param basis the identity (initial default value) for the reduction
5023         * @param reducer a commutative associative combining function
5024         * @return the task
5025         */
5026        public static <K,V> ForkJoinTask<Long> reduceToLong
5027            (ConcurrentHashMapV8<K,V> map,
5028             ObjectByObjectToLong<? super K, ? super V> transformer,
5029             long basis,
5030             LongByLongToLong reducer) {
5031            if (transformer == null || reducer == null)
5032                throw new NullPointerException();
5033            return new MapReduceMappingsToLongTask<K,V>
5034                (map, null, -1, null, transformer, basis, reducer);
5035        }
5036
5037        /**
5038         * Returns a task that when invoked, returns the result of
5039         * accumulating the given transformation of all (key, value) pairs
5040         * using the given reducer to combine values, and the given
5041         * basis as an identity value.
5042         *
5043         * @param transformer a function returning the transformation
5044         * for an element
5045         * @param basis the identity (initial default value) for the reduction
5046         * @param reducer a commutative associative combining function
5047         * @return the task
5048         */
5049        public static <K,V> ForkJoinTask<Integer> reduceToInt
5050            (ConcurrentHashMapV8<K,V> map,
5051             ObjectByObjectToInt<? super K, ? super V> transformer,
5052             int basis,
5053             IntByIntToInt reducer) {
5054            if (transformer == null || reducer == null)
5055                throw new NullPointerException();
5056            return new MapReduceMappingsToIntTask<K,V>
5057                (map, null, -1, null, transformer, basis, reducer);
5058        }
5059
5060        /**
5061         * Returns a task that when invoked, performs the given action
5062         * for each key.
5063         *
5064         * @param map the map
5065         * @param action the action
5066         * @return the task
5067         */
5068        public static <K,V> ForkJoinTask<Void> forEachKey
5069            (ConcurrentHashMapV8<K,V> map,
5070             Action<K> action) {
5071            if (action == null) throw new NullPointerException();
5072            return new ForEachKeyTask<K,V>(map, null, -1, action);
5073        }
5074
5075        /**
5076         * Returns a task that when invoked, performs the given action
5077         * for each non-null transformation of each key.
5078         *
5079         * @param map the map
5080         * @param transformer a function returning the transformation
5081         * for an element, or null if there is no transformation (in
5082         * which case the action is not applied)
5083         * @param action the action
5084         * @return the task
5085         */
5086        public static <K,V,U> ForkJoinTask<Void> forEachKey
5087            (ConcurrentHashMapV8<K,V> map,
5088             Fun<? super K, ? extends U> transformer,
5089             Action<U> action) {
5090            if (transformer == null || action == null)
5091                throw new NullPointerException();
5092            return new ForEachTransformedKeyTask<K,V,U>
5093                (map, null, -1, transformer, action);
5094        }
5095
5096        /**
5097         * Returns a task that when invoked, returns a non-null result
5098         * from applying the given search function on each key, or
5099         * null if none.  Upon success, further element processing is
5100         * suppressed and the results of any other parallel
5101         * invocations of the search function are ignored.
5102         *
5103         * @param map the map
5104         * @param searchFunction a function returning a non-null
5105         * result on success, else null
5106         * @return the task
5107         */
5108        public static <K,V,U> ForkJoinTask<U> searchKeys
5109            (ConcurrentHashMapV8<K,V> map,
5110             Fun<? super K, ? extends U> searchFunction) {
5111            if (searchFunction == null) throw new NullPointerException();
5112            return new SearchKeysTask<K,V,U>
5113                (map, null, -1, searchFunction,
5114                 new AtomicReference<U>());
5115        }
5116
5117        /**
5118         * Returns a task that when invoked, returns the result of
5119         * accumulating all keys using the given reducer to combine
5120         * values, or null if none.
5121         *
5122         * @param map the map
5123         * @param reducer a commutative associative combining function
5124         * @return the task
5125         */
5126        public static <K,V> ForkJoinTask<K> reduceKeys
5127            (ConcurrentHashMapV8<K,V> map,
5128             BiFun<? super K, ? super K, ? extends K> reducer) {
5129            if (reducer == null) throw new NullPointerException();
5130            return new ReduceKeysTask<K,V>
5131                (map, null, -1, null, reducer);
5132        }
5133
5134        /**
5135         * Returns a task that when invoked, returns the result of
5136         * accumulating the given transformation of all keys using the given
5137         * reducer to combine values, or null if none.
5138         *
5139         * @param map the map
5140         * @param transformer a function returning the transformation
5141         * for an element, or null if there is no transformation (in
5142         * which case it is not combined).
5143         * @param reducer a commutative associative combining function
5144         * @return the task
5145         */
5146        public static <K,V,U> ForkJoinTask<U> reduceKeys
5147            (ConcurrentHashMapV8<K,V> map,
5148             Fun<? super K, ? extends U> transformer,
5149             BiFun<? super U, ? super U, ? extends U> reducer) {
5150            if (transformer == null || reducer == null)
5151                throw new NullPointerException();
5152            return new MapReduceKeysTask<K,V,U>
5153                (map, null, -1, null, transformer, reducer);
5154        }
5155
5156        /**
5157         * Returns a task that when invoked, returns the result of
5158         * accumulating the given transformation of all keys using the given
5159         * reducer to combine values, and the given basis as an
5160         * identity value.
5161         *
5162         * @param map the map
5163         * @param transformer a function returning the transformation
5164         * for an element
5165         * @param basis the identity (initial default value) for the reduction
5166         * @param reducer a commutative associative combining function
5167         * @return the task
5168         */
5169        public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
5170            (ConcurrentHashMapV8<K,V> map,
5171             ObjectToDouble<? super K> transformer,
5172             double basis,
5173             DoubleByDoubleToDouble reducer) {
5174            if (transformer == null || reducer == null)
5175                throw new NullPointerException();
5176            return new MapReduceKeysToDoubleTask<K,V>
5177                (map, null, -1, null, transformer, basis, reducer);
5178        }
5179
5180        /**
5181         * Returns a task that when invoked, returns the result of
5182         * accumulating the given transformation of all keys using the given
5183         * reducer to combine values, and the given basis as an
5184         * identity value.
5185         *
5186         * @param map the map
5187         * @param transformer a function returning the transformation
5188         * for an element
5189         * @param basis the identity (initial default value) for the reduction
5190         * @param reducer a commutative associative combining function
5191         * @return the task
5192         */
5193        public static <K,V> ForkJoinTask<Long> reduceKeysToLong
5194            (ConcurrentHashMapV8<K,V> map,
5195             ObjectToLong<? super K> transformer,
5196             long basis,
5197             LongByLongToLong reducer) {
5198            if (transformer == null || reducer == null)
5199                throw new NullPointerException();
5200            return new MapReduceKeysToLongTask<K,V>
5201                (map, null, -1, null, transformer, basis, reducer);
5202        }
5203
5204        /**
5205         * Returns a task that when invoked, returns the result of
5206         * accumulating the given transformation of all keys using the given
5207         * reducer to combine values, and the given basis as an
5208         * identity value.
5209         *
5210         * @param map the map
5211         * @param transformer a function returning the transformation
5212         * for an element
5213         * @param basis the identity (initial default value) for the reduction
5214         * @param reducer a commutative associative combining function
5215         * @return the task
5216         */
5217        public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5218            (ConcurrentHashMapV8<K,V> map,
5219             ObjectToInt<? super K> transformer,
5220             int basis,
5221             IntByIntToInt reducer) {
5222            if (transformer == null || reducer == null)
5223                throw new NullPointerException();
5224            return new MapReduceKeysToIntTask<K,V>
5225                (map, null, -1, null, transformer, basis, reducer);
5226        }
5227
5228        /**
5229         * Returns a task that when invoked, performs the given action
5230         * for each value.
5231         *
5232         * @param map the map
5233         * @param action the action
5234         */
5235        public static <K,V> ForkJoinTask<Void> forEachValue
5236            (ConcurrentHashMapV8<K,V> map,
5237             Action<V> action) {
5238            if (action == null) throw new NullPointerException();
5239            return new ForEachValueTask<K,V>(map, null, -1, action);
5240        }
5241
5242        /**
5243         * Returns a task that when invoked, performs the given action
5244         * for each non-null transformation of each value.
5245         *
5246         * @param map the map
5247         * @param transformer a function returning the transformation
5248         * for an element, or null if there is no transformation (in
5249         * which case the action is not applied)
5250         * @param action the action
5251         */
5252        public static <K,V,U> ForkJoinTask<Void> forEachValue
5253            (ConcurrentHashMapV8<K,V> map,
5254             Fun<? super V, ? extends U> transformer,
5255             Action<U> action) {
5256            if (transformer == null || action == null)
5257                throw new NullPointerException();
5258            return new ForEachTransformedValueTask<K,V,U>
5259                (map, null, -1, transformer, action);
5260        }
5261
5262        /**
5263         * Returns a task that when invoked, returns a non-null result
5264         * from applying the given search function on each value, or
5265         * null if none.  Upon success, further element processing is
5266         * suppressed and the results of any other parallel
5267         * invocations of the search function are ignored.
5268         *
5269         * @param map the map
5270         * @param searchFunction a function returning a non-null
5271         * result on success, else null
5272         * @return the task
5273         */
5274        public static <K,V,U> ForkJoinTask<U> searchValues
5275            (ConcurrentHashMapV8<K,V> map,
5276             Fun<? super V, ? extends U> searchFunction) {
5277            if (searchFunction == null) throw new NullPointerException();
5278            return new SearchValuesTask<K,V,U>
5279                (map, null, -1, searchFunction,
5280                 new AtomicReference<U>());
5281        }
5282
5283        /**
5284         * Returns a task that when invoked, returns the result of
5285         * accumulating all values using the given reducer to combine
5286         * values, or null if none.
5287         *
5288         * @param map the map
5289         * @param reducer a commutative associative combining function
5290         * @return the task
5291         */
5292        public static <K,V> ForkJoinTask<V> reduceValues
5293            (ConcurrentHashMapV8<K,V> map,
5294             BiFun<? super V, ? super V, ? extends V> reducer) {
5295            if (reducer == null) throw new NullPointerException();
5296            return new ReduceValuesTask<K,V>
5297                (map, null, -1, null, reducer);
5298        }
5299
5300        /**
5301         * Returns a task that when invoked, returns the result of
5302         * accumulating the given transformation of all values using the
5303         * given reducer to combine values, or null if none.
5304         *
5305         * @param map the map
5306         * @param transformer a function returning the transformation
5307         * for an element, or null if there is no transformation (in
5308         * which case it is not combined).
5309         * @param reducer a commutative associative combining function
5310         * @return the task
5311         */
5312        public static <K,V,U> ForkJoinTask<U> reduceValues
5313            (ConcurrentHashMapV8<K,V> map,
5314             Fun<? super V, ? extends U> transformer,
5315             BiFun<? super U, ? super U, ? extends U> reducer) {
5316            if (transformer == null || reducer == null)
5317                throw new NullPointerException();
5318            return new MapReduceValuesTask<K,V,U>
5319                (map, null, -1, null, transformer, reducer);
5320        }
5321
5322        /**
5323         * Returns a task that when invoked, returns the result of
5324         * accumulating the given transformation of all values using the
5325         * given reducer to combine values, and the given basis as an
5326         * identity value.
5327         *
5328         * @param map the map
5329         * @param transformer a function returning the transformation
5330         * for an element
5331         * @param basis the identity (initial default value) for the reduction
5332         * @param reducer a commutative associative combining function
5333         * @return the task
5334         */
5335        public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5336            (ConcurrentHashMapV8<K,V> map,
5337             ObjectToDouble<? super V> transformer,
5338             double basis,
5339             DoubleByDoubleToDouble reducer) {
5340            if (transformer == null || reducer == null)
5341                throw new NullPointerException();
5342            return new MapReduceValuesToDoubleTask<K,V>
5343                (map, null, -1, null, transformer, basis, reducer);
5344        }
5345
5346        /**
5347         * Returns a task that when invoked, returns the result of
5348         * accumulating the given transformation of all values using the
5349         * given reducer to combine values, and the given basis as an
5350         * identity value.
5351         *
5352         * @param map the map
5353         * @param transformer a function returning the transformation
5354         * for an element
5355         * @param basis the identity (initial default value) for the reduction
5356         * @param reducer a commutative associative combining function
5357         * @return the task
5358         */
5359        public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5360            (ConcurrentHashMapV8<K,V> map,
5361             ObjectToLong<? super V> transformer,
5362             long basis,
5363             LongByLongToLong reducer) {
5364            if (transformer == null || reducer == null)
5365                throw new NullPointerException();
5366            return new MapReduceValuesToLongTask<K,V>
5367                (map, null, -1, null, transformer, basis, reducer);
5368        }
4658  
4659 <        /**
4660 <         * Returns a task that when invoked, returns the result of
4661 <         * accumulating the given transformation of all values using the
4662 <         * given reducer to combine values, and the given basis as an
4663 <         * identity value.
4664 <         *
5376 <         * @param map the map
5377 <         * @param transformer a function returning the transformation
5378 <         * for an element
5379 <         * @param basis the identity (initial default value) for the reduction
5380 <         * @param reducer a commutative associative combining function
5381 <         * @return the task
5382 <         */
5383 <        public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5384 <            (ConcurrentHashMapV8<K,V> map,
5385 <             ObjectToInt<? super V> transformer,
5386 <             int basis,
5387 <             IntByIntToInt reducer) {
5388 <            if (transformer == null || reducer == null)
5389 <                throw new NullPointerException();
5390 <            return new MapReduceValuesToIntTask<K,V>
5391 <                (map, null, -1, null, transformer, basis, reducer);
4659 >        public ConcurrentHashMapSpliterator<Map.Entry<K,V>> spliterator() {
4660 >            Node<K,V>[] t;
4661 >            ConcurrentHashMapV8<K,V> m = map;
4662 >            long n = m.sumCount();
4663 >            int f = (t = m.table) == null ? 0 : t.length;
4664 >            return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4665          }
4666  
4667 <        /**
5395 <         * Returns a task that when invoked, perform the given action
5396 <         * for each entry.
5397 <         *
5398 <         * @param map the map
5399 <         * @param action the action
5400 <         */
5401 <        public static <K,V> ForkJoinTask<Void> forEachEntry
5402 <            (ConcurrentHashMapV8<K,V> map,
5403 <             Action<Map.Entry<K,V>> action) {
4667 >        public void forEach(Action<? super Map.Entry<K,V>> action) {
4668              if (action == null) throw new NullPointerException();
4669 <            return new ForEachEntryTask<K,V>(map, null, -1, action);
4670 <        }
4671 <
4672 <        /**
4673 <         * Returns a task that when invoked, perform the given action
4674 <         * for each non-null transformation of each entry.
5411 <         *
5412 <         * @param map the map
5413 <         * @param transformer a function returning the transformation
5414 <         * for an element, or null if there is no transformation (in
5415 <         * which case the action is not applied)
5416 <         * @param action the action
5417 <         */
5418 <        public static <K,V,U> ForkJoinTask<Void> forEachEntry
5419 <            (ConcurrentHashMapV8<K,V> map,
5420 <             Fun<Map.Entry<K,V>, ? extends U> transformer,
5421 <             Action<U> action) {
5422 <            if (transformer == null || action == null)
5423 <                throw new NullPointerException();
5424 <            return new ForEachTransformedEntryTask<K,V,U>
5425 <                (map, null, -1, transformer, action);
5426 <        }
5427 <
5428 <        /**
5429 <         * Returns a task that when invoked, returns a non-null result
5430 <         * from applying the given search function on each entry, or
5431 <         * null if none.  Upon success, further element processing is
5432 <         * suppressed and the results of any other parallel
5433 <         * invocations of the search function are ignored.
5434 <         *
5435 <         * @param map the map
5436 <         * @param searchFunction a function returning a non-null
5437 <         * result on success, else null
5438 <         * @return the task
5439 <         */
5440 <        public static <K,V,U> ForkJoinTask<U> searchEntries
5441 <            (ConcurrentHashMapV8<K,V> map,
5442 <             Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
5443 <            if (searchFunction == null) throw new NullPointerException();
5444 <            return new SearchEntriesTask<K,V,U>
5445 <                (map, null, -1, searchFunction,
5446 <                 new AtomicReference<U>());
5447 <        }
5448 <
5449 <        /**
5450 <         * Returns a task that when invoked, returns the result of
5451 <         * accumulating all entries using the given reducer to combine
5452 <         * values, or null if none.
5453 <         *
5454 <         * @param map the map
5455 <         * @param reducer a commutative associative combining function
5456 <         * @return the task
5457 <         */
5458 <        public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5459 <            (ConcurrentHashMapV8<K,V> map,
5460 <             BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5461 <            if (reducer == null) throw new NullPointerException();
5462 <            return new ReduceEntriesTask<K,V>
5463 <                (map, null, -1, null, reducer);
4669 >            Node<K,V>[] t;
4670 >            if ((t = map.table) != null) {
4671 >                Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4672 >                for (Node<K,V> p; (p = it.advance()) != null; )
4673 >                    action.apply(new MapEntry<K,V>(p.key, p.val, map));
4674 >            }
4675          }
4676  
4677 <        /**
5467 <         * Returns a task that when invoked, returns the result of
5468 <         * accumulating the given transformation of all entries using the
5469 <         * given reducer to combine values, or null if none.
5470 <         *
5471 <         * @param map the map
5472 <         * @param transformer a function returning the transformation
5473 <         * for an element, or null if there is no transformation (in
5474 <         * which case it is not combined).
5475 <         * @param reducer a commutative associative combining function
5476 <         * @return the task
5477 <         */
5478 <        public static <K,V,U> ForkJoinTask<U> reduceEntries
5479 <            (ConcurrentHashMapV8<K,V> map,
5480 <             Fun<Map.Entry<K,V>, ? extends U> transformer,
5481 <             BiFun<? super U, ? super U, ? extends U> reducer) {
5482 <            if (transformer == null || reducer == null)
5483 <                throw new NullPointerException();
5484 <            return new MapReduceEntriesTask<K,V,U>
5485 <                (map, null, -1, null, transformer, reducer);
5486 <        }
4677 >    }
4678  
4679 <        /**
5489 <         * Returns a task that when invoked, returns the result of
5490 <         * accumulating the given transformation of all entries using the
5491 <         * given reducer to combine values, and the given basis as an
5492 <         * identity value.
5493 <         *
5494 <         * @param map the map
5495 <         * @param transformer a function returning the transformation
5496 <         * for an element
5497 <         * @param basis the identity (initial default value) for the reduction
5498 <         * @param reducer a commutative associative combining function
5499 <         * @return the task
5500 <         */
5501 <        public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5502 <            (ConcurrentHashMapV8<K,V> map,
5503 <             ObjectToDouble<Map.Entry<K,V>> transformer,
5504 <             double basis,
5505 <             DoubleByDoubleToDouble reducer) {
5506 <            if (transformer == null || reducer == null)
5507 <                throw new NullPointerException();
5508 <            return new MapReduceEntriesToDoubleTask<K,V>
5509 <                (map, null, -1, null, transformer, basis, reducer);
5510 <        }
4679 >    // -------------------------------------------------------
4680  
4681 <        /**
4682 <         * Returns a task that when invoked, returns the result of
4683 <         * accumulating the given transformation of all entries using the
4684 <         * given reducer to combine values, and the given basis as an
4685 <         * identity value.
4686 <         *
4687 <         * @param map the map
4688 <         * @param transformer a function returning the transformation
4689 <         * for an element
4690 <         * @param basis the identity (initial default value) for the reduction
4691 <         * @param reducer a commutative associative combining function
4692 <         * @return the task
4693 <         */
4694 <        public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
4695 <            (ConcurrentHashMapV8<K,V> map,
4696 <             ObjectToLong<Map.Entry<K,V>> transformer,
4697 <             long basis,
4698 <             LongByLongToLong reducer) {
4699 <            if (transformer == null || reducer == null)
4700 <                throw new NullPointerException();
4701 <            return new MapReduceEntriesToLongTask<K,V>
4702 <                (map, null, -1, null, transformer, basis, reducer);
4681 >    /**
4682 >     * Base class for bulk tasks. Repeats some fields and code from
4683 >     * class Traverser, because we need to subclass CountedCompleter.
4684 >     */
4685 >    abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4686 >        Node<K,V>[] tab;        // same as Traverser
4687 >        Node<K,V> next;
4688 >        int index;
4689 >        int baseIndex;
4690 >        int baseLimit;
4691 >        final int baseSize;
4692 >        int batch;              // split control
4693 >
4694 >        BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4695 >            super(par);
4696 >            this.batch = b;
4697 >            this.index = this.baseIndex = i;
4698 >            if ((this.tab = t) == null)
4699 >                this.baseSize = this.baseLimit = 0;
4700 >            else if (par == null)
4701 >                this.baseSize = this.baseLimit = t.length;
4702 >            else {
4703 >                this.baseLimit = f;
4704 >                this.baseSize = par.baseSize;
4705 >            }
4706          }
4707  
4708          /**
4709 <         * Returns a task that when invoked, returns the result of
5538 <         * accumulating the given transformation of all entries using the
5539 <         * given reducer to combine values, and the given basis as an
5540 <         * identity value.
5541 <         *
5542 <         * @param map the map
5543 <         * @param transformer a function returning the transformation
5544 <         * for an element
5545 <         * @param basis the identity (initial default value) for the reduction
5546 <         * @param reducer a commutative associative combining function
5547 <         * @return the task
4709 >         * Same as Traverser version
4710           */
4711 <        public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
4712 <            (ConcurrentHashMapV8<K,V> map,
4713 <             ObjectToInt<Map.Entry<K,V>> transformer,
4714 <             int basis,
4715 <             IntByIntToInt reducer) {
4716 <            if (transformer == null || reducer == null)
4717 <                throw new NullPointerException();
4718 <            return new MapReduceEntriesToIntTask<K,V>
4719 <                (map, null, -1, null, transformer, basis, reducer);
4711 >        final Node<K,V> advance() {
4712 >            Node<K,V> e;
4713 >            if ((e = next) != null)
4714 >                e = e.next;
4715 >            for (;;) {
4716 >                Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4717 >                if (e != null)
4718 >                    return next = e;
4719 >                if (baseIndex >= baseLimit || (t = tab) == null ||
4720 >                    (n = t.length) <= (i = index) || i < 0)
4721 >                    return next = null;
4722 >                if ((e = tabAt(t, index)) != null && e.hash < 0) {
4723 >                    if (e instanceof ForwardingNode) {
4724 >                        tab = ((ForwardingNode<K,V>)e).nextTable;
4725 >                        e = null;
4726 >                        continue;
4727 >                    }
4728 >                    else if (e instanceof TreeBin)
4729 >                        e = ((TreeBin<K,V>)e).first;
4730 >                    else
4731 >                        e = null;
4732 >                }
4733 >                if ((index += baseSize) >= n)
4734 >                    index = ++baseIndex;    // visit upper slots if present
4735 >            }
4736          }
4737      }
4738  
5561    // -------------------------------------------------------
5562
4739      /*
4740       * Task classes. Coded in a regular but ugly format/style to
4741       * simplify checks that each variant differs in the right way from
# Line 5567 | Line 4743 | public class ConcurrentHashMapV8<K, V>
4743       * that we've already null-checked task arguments, so we force
4744       * simplest hoisted bypass to help avoid convoluted traps.
4745       */
4746 <
4747 <    @SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
4748 <        extends Traverser<K,V,Void> {
4749 <        final Action<K> action;
4746 >    @SuppressWarnings("serial")
4747 >    static final class ForEachKeyTask<K,V>
4748 >        extends BulkTask<K,V,Void> {
4749 >        final Action<? super K> action;
4750          ForEachKeyTask
4751 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4752 <             Action<K> action) {
4753 <            super(m, p, b);
4751 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4752 >             Action<? super K> action) {
4753 >            super(p, b, i, f, t);
4754              this.action = action;
4755          }
4756 <        @SuppressWarnings("unchecked") public final void compute() {
4757 <            final Action<K> action;
4756 >        public final void compute() {
4757 >            final Action<? super K> action;
4758              if ((action = this.action) != null) {
4759 <                for (int b; (b = preSplit()) > 0;)
4760 <                    new ForEachKeyTask<K,V>(map, this, b, action).fork();
4761 <                while (advance() != null)
4762 <                    action.apply((K)nextKey);
4759 >                for (int i = baseIndex, f, h; batch > 0 &&
4760 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4761 >                    addToPendingCount(1);
4762 >                    new ForEachKeyTask<K,V>
4763 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4764 >                         action).fork();
4765 >                }
4766 >                for (Node<K,V> p; (p = advance()) != null;)
4767 >                    action.apply(p.key);
4768                  propagateCompletion();
4769              }
4770          }
4771      }
4772  
4773 <    @SuppressWarnings("serial") static final class ForEachValueTask<K,V>
4774 <        extends Traverser<K,V,Void> {
4775 <        final Action<V> action;
4773 >    @SuppressWarnings("serial")
4774 >    static final class ForEachValueTask<K,V>
4775 >        extends BulkTask<K,V,Void> {
4776 >        final Action<? super V> action;
4777          ForEachValueTask
4778 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4779 <             Action<V> action) {
4780 <            super(m, p, b);
4778 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4779 >             Action<? super V> action) {
4780 >            super(p, b, i, f, t);
4781              this.action = action;
4782          }
4783 <        @SuppressWarnings("unchecked") public final void compute() {
4784 <            final Action<V> action;
4783 >        public final void compute() {
4784 >            final Action<? super V> action;
4785              if ((action = this.action) != null) {
4786 <                for (int b; (b = preSplit()) > 0;)
4787 <                    new ForEachValueTask<K,V>(map, this, b, action).fork();
4788 <                V v;
4789 <                while ((v = advance()) != null)
4790 <                    action.apply(v);
4786 >                for (int i = baseIndex, f, h; batch > 0 &&
4787 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4788 >                    addToPendingCount(1);
4789 >                    new ForEachValueTask<K,V>
4790 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4791 >                         action).fork();
4792 >                }
4793 >                for (Node<K,V> p; (p = advance()) != null;)
4794 >                    action.apply(p.val);
4795                  propagateCompletion();
4796              }
4797          }
4798      }
4799  
4800 <    @SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
4801 <        extends Traverser<K,V,Void> {
4802 <        final Action<Entry<K,V>> action;
4800 >    @SuppressWarnings("serial")
4801 >    static final class ForEachEntryTask<K,V>
4802 >        extends BulkTask<K,V,Void> {
4803 >        final Action<? super Entry<K,V>> action;
4804          ForEachEntryTask
4805 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4806 <             Action<Entry<K,V>> action) {
4807 <            super(m, p, b);
4805 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4806 >             Action<? super Entry<K,V>> action) {
4807 >            super(p, b, i, f, t);
4808              this.action = action;
4809          }
4810 <        @SuppressWarnings("unchecked") public final void compute() {
4811 <            final Action<Entry<K,V>> action;
4810 >        public final void compute() {
4811 >            final Action<? super Entry<K,V>> action;
4812              if ((action = this.action) != null) {
4813 <                for (int b; (b = preSplit()) > 0;)
4814 <                    new ForEachEntryTask<K,V>(map, this, b, action).fork();
4815 <                V v;
4816 <                while ((v = advance()) != null)
4817 <                    action.apply(entryFor((K)nextKey, v));
4813 >                for (int i = baseIndex, f, h; batch > 0 &&
4814 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4815 >                    addToPendingCount(1);
4816 >                    new ForEachEntryTask<K,V>
4817 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4818 >                         action).fork();
4819 >                }
4820 >                for (Node<K,V> p; (p = advance()) != null; )
4821 >                    action.apply(p);
4822                  propagateCompletion();
4823              }
4824          }
4825      }
4826  
4827 <    @SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
4828 <        extends Traverser<K,V,Void> {
4829 <        final BiAction<K,V> action;
4827 >    @SuppressWarnings("serial")
4828 >    static final class ForEachMappingTask<K,V>
4829 >        extends BulkTask<K,V,Void> {
4830 >        final BiAction<? super K, ? super V> action;
4831          ForEachMappingTask
4832 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4833 <             BiAction<K,V> action) {
4834 <            super(m, p, b);
4832 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4833 >             BiAction<? super K,? super V> action) {
4834 >            super(p, b, i, f, t);
4835              this.action = action;
4836          }
4837 <        @SuppressWarnings("unchecked") public final void compute() {
4838 <            final BiAction<K,V> action;
4837 >        public final void compute() {
4838 >            final BiAction<? super K, ? super V> action;
4839              if ((action = this.action) != null) {
4840 <                for (int b; (b = preSplit()) > 0;)
4841 <                    new ForEachMappingTask<K,V>(map, this, b, action).fork();
4842 <                V v;
4843 <                while ((v = advance()) != null)
4844 <                    action.apply((K)nextKey, v);
4840 >                for (int i = baseIndex, f, h; batch > 0 &&
4841 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4842 >                    addToPendingCount(1);
4843 >                    new ForEachMappingTask<K,V>
4844 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4845 >                         action).fork();
4846 >                }
4847 >                for (Node<K,V> p; (p = advance()) != null; )
4848 >                    action.apply(p.key, p.val);
4849                  propagateCompletion();
4850              }
4851          }
4852      }
4853  
4854 <    @SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
4855 <        extends Traverser<K,V,Void> {
4854 >    @SuppressWarnings("serial")
4855 >    static final class ForEachTransformedKeyTask<K,V,U>
4856 >        extends BulkTask<K,V,Void> {
4857          final Fun<? super K, ? extends U> transformer;
4858 <        final Action<U> action;
4858 >        final Action<? super U> action;
4859          ForEachTransformedKeyTask
4860 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4861 <             Fun<? super K, ? extends U> transformer, Action<U> action) {
4862 <            super(m, p, b);
4860 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4861 >             Fun<? super K, ? extends U> transformer, Action<? super U> action) {
4862 >            super(p, b, i, f, t);
4863              this.transformer = transformer; this.action = action;
4864          }
4865 <        @SuppressWarnings("unchecked") public final void compute() {
4865 >        public final void compute() {
4866              final Fun<? super K, ? extends U> transformer;
4867 <            final Action<U> action;
4867 >            final Action<? super U> action;
4868              if ((transformer = this.transformer) != null &&
4869                  (action = this.action) != null) {
4870 <                for (int b; (b = preSplit()) > 0;)
4870 >                for (int i = baseIndex, f, h; batch > 0 &&
4871 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4872 >                    addToPendingCount(1);
4873                      new ForEachTransformedKeyTask<K,V,U>
4874 <                        (map, this, b, transformer, action).fork();
4875 <                U u;
4876 <                while (advance() != null) {
4877 <                    if ((u = transformer.apply((K)nextKey)) != null)
4874 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4875 >                         transformer, action).fork();
4876 >                }
4877 >                for (Node<K,V> p; (p = advance()) != null; ) {
4878 >                    U u;
4879 >                    if ((u = transformer.apply(p.key)) != null)
4880                          action.apply(u);
4881                  }
4882                  propagateCompletion();
# Line 5683 | Line 4884 | public class ConcurrentHashMapV8<K, V>
4884          }
4885      }
4886  
4887 <    @SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
4888 <        extends Traverser<K,V,Void> {
4887 >    @SuppressWarnings("serial")
4888 >    static final class ForEachTransformedValueTask<K,V,U>
4889 >        extends BulkTask<K,V,Void> {
4890          final Fun<? super V, ? extends U> transformer;
4891 <        final Action<U> action;
4891 >        final Action<? super U> action;
4892          ForEachTransformedValueTask
4893 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4894 <             Fun<? super V, ? extends U> transformer, Action<U> action) {
4895 <            super(m, p, b);
4893 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4894 >             Fun<? super V, ? extends U> transformer, Action<? super U> action) {
4895 >            super(p, b, i, f, t);
4896              this.transformer = transformer; this.action = action;
4897          }
4898 <        @SuppressWarnings("unchecked") public final void compute() {
4898 >        public final void compute() {
4899              final Fun<? super V, ? extends U> transformer;
4900 <            final Action<U> action;
4900 >            final Action<? super U> action;
4901              if ((transformer = this.transformer) != null &&
4902                  (action = this.action) != null) {
4903 <                for (int b; (b = preSplit()) > 0;)
4903 >                for (int i = baseIndex, f, h; batch > 0 &&
4904 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4905 >                    addToPendingCount(1);
4906                      new ForEachTransformedValueTask<K,V,U>
4907 <                        (map, this, b, transformer, action).fork();
4908 <                V v; U u;
4909 <                while ((v = advance()) != null) {
4910 <                    if ((u = transformer.apply(v)) != null)
4907 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4908 >                         transformer, action).fork();
4909 >                }
4910 >                for (Node<K,V> p; (p = advance()) != null; ) {
4911 >                    U u;
4912 >                    if ((u = transformer.apply(p.val)) != null)
4913                          action.apply(u);
4914                  }
4915                  propagateCompletion();
# Line 5711 | Line 4917 | public class ConcurrentHashMapV8<K, V>
4917          }
4918      }
4919  
4920 <    @SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
4921 <        extends Traverser<K,V,Void> {
4920 >    @SuppressWarnings("serial")
4921 >    static final class ForEachTransformedEntryTask<K,V,U>
4922 >        extends BulkTask<K,V,Void> {
4923          final Fun<Map.Entry<K,V>, ? extends U> transformer;
4924 <        final Action<U> action;
4924 >        final Action<? super U> action;
4925          ForEachTransformedEntryTask
4926 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4927 <             Fun<Map.Entry<K,V>, ? extends U> transformer, Action<U> action) {
4928 <            super(m, p, b);
4926 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4927 >             Fun<Map.Entry<K,V>, ? extends U> transformer, Action<? super U> action) {
4928 >            super(p, b, i, f, t);
4929              this.transformer = transformer; this.action = action;
4930          }
4931 <        @SuppressWarnings("unchecked") public final void compute() {
4931 >        public final void compute() {
4932              final Fun<Map.Entry<K,V>, ? extends U> transformer;
4933 <            final Action<U> action;
4933 >            final Action<? super U> action;
4934              if ((transformer = this.transformer) != null &&
4935                  (action = this.action) != null) {
4936 <                for (int b; (b = preSplit()) > 0;)
4936 >                for (int i = baseIndex, f, h; batch > 0 &&
4937 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4938 >                    addToPendingCount(1);
4939                      new ForEachTransformedEntryTask<K,V,U>
4940 <                        (map, this, b, transformer, action).fork();
4941 <                V v; U u;
4942 <                while ((v = advance()) != null) {
4943 <                    if ((u = transformer.apply(entryFor((K)nextKey,
4944 <                                                        v))) != null)
4940 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4941 >                         transformer, action).fork();
4942 >                }
4943 >                for (Node<K,V> p; (p = advance()) != null; ) {
4944 >                    U u;
4945 >                    if ((u = transformer.apply(p)) != null)
4946                          action.apply(u);
4947                  }
4948                  propagateCompletion();
# Line 5740 | Line 4950 | public class ConcurrentHashMapV8<K, V>
4950          }
4951      }
4952  
4953 <    @SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
4954 <        extends Traverser<K,V,Void> {
4953 >    @SuppressWarnings("serial")
4954 >    static final class ForEachTransformedMappingTask<K,V,U>
4955 >        extends BulkTask<K,V,Void> {
4956          final BiFun<? super K, ? super V, ? extends U> transformer;
4957 <        final Action<U> action;
4957 >        final Action<? super U> action;
4958          ForEachTransformedMappingTask
4959 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4959 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4960               BiFun<? super K, ? super V, ? extends U> transformer,
4961 <             Action<U> action) {
4962 <            super(m, p, b);
4961 >             Action<? super U> action) {
4962 >            super(p, b, i, f, t);
4963              this.transformer = transformer; this.action = action;
4964          }
4965 <        @SuppressWarnings("unchecked") public final void compute() {
4965 >        public final void compute() {
4966              final BiFun<? super K, ? super V, ? extends U> transformer;
4967 <            final Action<U> action;
4967 >            final Action<? super U> action;
4968              if ((transformer = this.transformer) != null &&
4969                  (action = this.action) != null) {
4970 <                for (int b; (b = preSplit()) > 0;)
4970 >                for (int i = baseIndex, f, h; batch > 0 &&
4971 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
4972 >                    addToPendingCount(1);
4973                      new ForEachTransformedMappingTask<K,V,U>
4974 <                        (map, this, b, transformer, action).fork();
4975 <                V v; U u;
4976 <                while ((v = advance()) != null) {
4977 <                    if ((u = transformer.apply((K)nextKey, v)) != null)
4974 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
4975 >                         transformer, action).fork();
4976 >                }
4977 >                for (Node<K,V> p; (p = advance()) != null; ) {
4978 >                    U u;
4979 >                    if ((u = transformer.apply(p.key, p.val)) != null)
4980                          action.apply(u);
4981                  }
4982                  propagateCompletion();
# Line 5769 | Line 4984 | public class ConcurrentHashMapV8<K, V>
4984          }
4985      }
4986  
4987 <    @SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
4988 <        extends Traverser<K,V,U> {
4987 >    @SuppressWarnings("serial")
4988 >    static final class SearchKeysTask<K,V,U>
4989 >        extends BulkTask<K,V,U> {
4990          final Fun<? super K, ? extends U> searchFunction;
4991          final AtomicReference<U> result;
4992          SearchKeysTask
4993 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
4993 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4994               Fun<? super K, ? extends U> searchFunction,
4995               AtomicReference<U> result) {
4996 <            super(m, p, b);
4996 >            super(p, b, i, f, t);
4997              this.searchFunction = searchFunction; this.result = result;
4998          }
4999          public final U getRawResult() { return result.get(); }
5000 <        @SuppressWarnings("unchecked") public final void compute() {
5000 >        public final void compute() {
5001              final Fun<? super K, ? extends U> searchFunction;
5002              final AtomicReference<U> result;
5003              if ((searchFunction = this.searchFunction) != null &&
5004                  (result = this.result) != null) {
5005 <                for (int b;;) {
5005 >                for (int i = baseIndex, f, h; batch > 0 &&
5006 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5007                      if (result.get() != null)
5008                          return;
5009 <                    if ((b = preSplit()) <= 0)
5793 <                        break;
5009 >                    addToPendingCount(1);
5010                      new SearchKeysTask<K,V,U>
5011 <                        (map, this, b, searchFunction, result).fork();
5011 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5012 >                         searchFunction, result).fork();
5013                  }
5014                  while (result.get() == null) {
5015                      U u;
5016 <                    if (advance() == null) {
5016 >                    Node<K,V> p;
5017 >                    if ((p = advance()) == null) {
5018                          propagateCompletion();
5019                          break;
5020                      }
5021 <                    if ((u = searchFunction.apply((K)nextKey)) != null) {
5021 >                    if ((u = searchFunction.apply(p.key)) != null) {
5022                          if (result.compareAndSet(null, u))
5023                              quietlyCompleteRoot();
5024                          break;
# Line 5810 | Line 5028 | public class ConcurrentHashMapV8<K, V>
5028          }
5029      }
5030  
5031 <    @SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5032 <        extends Traverser<K,V,U> {
5031 >    @SuppressWarnings("serial")
5032 >    static final class SearchValuesTask<K,V,U>
5033 >        extends BulkTask<K,V,U> {
5034          final Fun<? super V, ? extends U> searchFunction;
5035          final AtomicReference<U> result;
5036          SearchValuesTask
5037 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5037 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5038               Fun<? super V, ? extends U> searchFunction,
5039               AtomicReference<U> result) {
5040 <            super(m, p, b);
5040 >            super(p, b, i, f, t);
5041              this.searchFunction = searchFunction; this.result = result;
5042          }
5043          public final U getRawResult() { return result.get(); }
5044 <        @SuppressWarnings("unchecked") public final void compute() {
5044 >        public final void compute() {
5045              final Fun<? super V, ? extends U> searchFunction;
5046              final AtomicReference<U> result;
5047              if ((searchFunction = this.searchFunction) != null &&
5048                  (result = this.result) != null) {
5049 <                for (int b;;) {
5049 >                for (int i = baseIndex, f, h; batch > 0 &&
5050 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5051                      if (result.get() != null)
5052                          return;
5053 <                    if ((b = preSplit()) <= 0)
5834 <                        break;
5053 >                    addToPendingCount(1);
5054                      new SearchValuesTask<K,V,U>
5055 <                        (map, this, b, searchFunction, result).fork();
5055 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5056 >                         searchFunction, result).fork();
5057                  }
5058                  while (result.get() == null) {
5059 <                    V v; U u;
5060 <                    if ((v = advance()) == null) {
5059 >                    U u;
5060 >                    Node<K,V> p;
5061 >                    if ((p = advance()) == null) {
5062                          propagateCompletion();
5063                          break;
5064                      }
5065 <                    if ((u = searchFunction.apply(v)) != null) {
5065 >                    if ((u = searchFunction.apply(p.val)) != null) {
5066                          if (result.compareAndSet(null, u))
5067                              quietlyCompleteRoot();
5068                          break;
# Line 5851 | Line 5072 | public class ConcurrentHashMapV8<K, V>
5072          }
5073      }
5074  
5075 <    @SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5076 <        extends Traverser<K,V,U> {
5075 >    @SuppressWarnings("serial")
5076 >    static final class SearchEntriesTask<K,V,U>
5077 >        extends BulkTask<K,V,U> {
5078          final Fun<Entry<K,V>, ? extends U> searchFunction;
5079          final AtomicReference<U> result;
5080          SearchEntriesTask
5081 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5081 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5082               Fun<Entry<K,V>, ? extends U> searchFunction,
5083               AtomicReference<U> result) {
5084 <            super(m, p, b);
5084 >            super(p, b, i, f, t);
5085              this.searchFunction = searchFunction; this.result = result;
5086          }
5087          public final U getRawResult() { return result.get(); }
5088 <        @SuppressWarnings("unchecked") public final void compute() {
5088 >        public final void compute() {
5089              final Fun<Entry<K,V>, ? extends U> searchFunction;
5090              final AtomicReference<U> result;
5091              if ((searchFunction = this.searchFunction) != null &&
5092                  (result = this.result) != null) {
5093 <                for (int b;;) {
5093 >                for (int i = baseIndex, f, h; batch > 0 &&
5094 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5095                      if (result.get() != null)
5096                          return;
5097 <                    if ((b = preSplit()) <= 0)
5875 <                        break;
5097 >                    addToPendingCount(1);
5098                      new SearchEntriesTask<K,V,U>
5099 <                        (map, this, b, searchFunction, result).fork();
5099 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5100 >                         searchFunction, result).fork();
5101                  }
5102                  while (result.get() == null) {
5103 <                    V v; U u;
5104 <                    if ((v = advance()) == null) {
5103 >                    U u;
5104 >                    Node<K,V> p;
5105 >                    if ((p = advance()) == null) {
5106                          propagateCompletion();
5107                          break;
5108                      }
5109 <                    if ((u = searchFunction.apply(entryFor((K)nextKey,
5886 <                                                           v))) != null) {
5109 >                    if ((u = searchFunction.apply(p)) != null) {
5110                          if (result.compareAndSet(null, u))
5111                              quietlyCompleteRoot();
5112                          return;
# Line 5893 | Line 5116 | public class ConcurrentHashMapV8<K, V>
5116          }
5117      }
5118  
5119 <    @SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5120 <        extends Traverser<K,V,U> {
5119 >    @SuppressWarnings("serial")
5120 >    static final class SearchMappingsTask<K,V,U>
5121 >        extends BulkTask<K,V,U> {
5122          final BiFun<? super K, ? super V, ? extends U> searchFunction;
5123          final AtomicReference<U> result;
5124          SearchMappingsTask
5125 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5125 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5126               BiFun<? super K, ? super V, ? extends U> searchFunction,
5127               AtomicReference<U> result) {
5128 <            super(m, p, b);
5128 >            super(p, b, i, f, t);
5129              this.searchFunction = searchFunction; this.result = result;
5130          }
5131          public final U getRawResult() { return result.get(); }
5132 <        @SuppressWarnings("unchecked") public final void compute() {
5132 >        public final void compute() {
5133              final BiFun<? super K, ? super V, ? extends U> searchFunction;
5134              final AtomicReference<U> result;
5135              if ((searchFunction = this.searchFunction) != null &&
5136                  (result = this.result) != null) {
5137 <                for (int b;;) {
5137 >                for (int i = baseIndex, f, h; batch > 0 &&
5138 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5139                      if (result.get() != null)
5140                          return;
5141 <                    if ((b = preSplit()) <= 0)
5917 <                        break;
5141 >                    addToPendingCount(1);
5142                      new SearchMappingsTask<K,V,U>
5143 <                        (map, this, b, searchFunction, result).fork();
5143 >                        (this, batch >>>= 1, baseLimit = h, f, tab,
5144 >                         searchFunction, result).fork();
5145                  }
5146                  while (result.get() == null) {
5147 <                    V v; U u;
5148 <                    if ((v = advance()) == null) {
5147 >                    U u;
5148 >                    Node<K,V> p;
5149 >                    if ((p = advance()) == null) {
5150                          propagateCompletion();
5151                          break;
5152                      }
5153 <                    if ((u = searchFunction.apply((K)nextKey, v)) != null) {
5153 >                    if ((u = searchFunction.apply(p.key, p.val)) != null) {
5154                          if (result.compareAndSet(null, u))
5155                              quietlyCompleteRoot();
5156                          break;
# Line 5934 | Line 5160 | public class ConcurrentHashMapV8<K, V>
5160          }
5161      }
5162  
5163 <    @SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5164 <        extends Traverser<K,V,K> {
5163 >    @SuppressWarnings("serial")
5164 >    static final class ReduceKeysTask<K,V>
5165 >        extends BulkTask<K,V,K> {
5166          final BiFun<? super K, ? super K, ? extends K> reducer;
5167          K result;
5168          ReduceKeysTask<K,V> rights, nextRight;
5169          ReduceKeysTask
5170 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5170 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5171               ReduceKeysTask<K,V> nextRight,
5172               BiFun<? super K, ? super K, ? extends K> reducer) {
5173 <            super(m, p, b); this.nextRight = nextRight;
5173 >            super(p, b, i, f, t); this.nextRight = nextRight;
5174              this.reducer = reducer;
5175          }
5176          public final K getRawResult() { return result; }
5177 <        @SuppressWarnings("unchecked") public final void compute() {
5177 >        public final void compute() {
5178              final BiFun<? super K, ? super K, ? extends K> reducer;
5179              if ((reducer = this.reducer) != null) {
5180 <                for (int b; (b = preSplit()) > 0;)
5180 >                for (int i = baseIndex, f, h; batch > 0 &&
5181 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5182 >                    addToPendingCount(1);
5183                      (rights = new ReduceKeysTask<K,V>
5184 <                     (map, this, b, rights, reducer)).fork();
5184 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5185 >                      rights, reducer)).fork();
5186 >                }
5187                  K r = null;
5188 <                while (advance() != null) {
5189 <                    K u = (K)nextKey;
5190 <                    r = (r == null) ? u : reducer.apply(r, u);
5188 >                for (Node<K,V> p; (p = advance()) != null; ) {
5189 >                    K u = p.key;
5190 >                    r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5191                  }
5192                  result = r;
5193                  CountedCompleter<?> c;
5194                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5195 <                    ReduceKeysTask<K,V>
5195 >                    @SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5196                          t = (ReduceKeysTask<K,V>)c,
5197                          s = t.rights;
5198                      while (s != null) {
# Line 5976 | Line 5207 | public class ConcurrentHashMapV8<K, V>
5207          }
5208      }
5209  
5210 <    @SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
5211 <        extends Traverser<K,V,V> {
5210 >    @SuppressWarnings("serial")
5211 >    static final class ReduceValuesTask<K,V>
5212 >        extends BulkTask<K,V,V> {
5213          final BiFun<? super V, ? super V, ? extends V> reducer;
5214          V result;
5215          ReduceValuesTask<K,V> rights, nextRight;
5216          ReduceValuesTask
5217 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5217 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5218               ReduceValuesTask<K,V> nextRight,
5219               BiFun<? super V, ? super V, ? extends V> reducer) {
5220 <            super(m, p, b); this.nextRight = nextRight;
5220 >            super(p, b, i, f, t); this.nextRight = nextRight;
5221              this.reducer = reducer;
5222          }
5223          public final V getRawResult() { return result; }
5224 <        @SuppressWarnings("unchecked") public final void compute() {
5224 >        public final void compute() {
5225              final BiFun<? super V, ? super V, ? extends V> reducer;
5226              if ((reducer = this.reducer) != null) {
5227 <                for (int b; (b = preSplit()) > 0;)
5227 >                for (int i = baseIndex, f, h; batch > 0 &&
5228 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5229 >                    addToPendingCount(1);
5230                      (rights = new ReduceValuesTask<K,V>
5231 <                     (map, this, b, rights, reducer)).fork();
5231 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5232 >                      rights, reducer)).fork();
5233 >                }
5234                  V r = null;
5235 <                V v;
5236 <                while ((v = advance()) != null) {
5237 <                    V u = v;
6002 <                    r = (r == null) ? u : reducer.apply(r, u);
5235 >                for (Node<K,V> p; (p = advance()) != null; ) {
5236 >                    V v = p.val;
5237 >                    r = (r == null) ? v : reducer.apply(r, v);
5238                  }
5239                  result = r;
5240                  CountedCompleter<?> c;
5241                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5242 <                    ReduceValuesTask<K,V>
5242 >                    @SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5243                          t = (ReduceValuesTask<K,V>)c,
5244                          s = t.rights;
5245                      while (s != null) {
# Line 6019 | Line 5254 | public class ConcurrentHashMapV8<K, V>
5254          }
5255      }
5256  
5257 <    @SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
5258 <        extends Traverser<K,V,Map.Entry<K,V>> {
5257 >    @SuppressWarnings("serial")
5258 >    static final class ReduceEntriesTask<K,V>
5259 >        extends BulkTask<K,V,Map.Entry<K,V>> {
5260          final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5261          Map.Entry<K,V> result;
5262          ReduceEntriesTask<K,V> rights, nextRight;
5263          ReduceEntriesTask
5264 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5264 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5265               ReduceEntriesTask<K,V> nextRight,
5266               BiFun<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5267 <            super(m, p, b); this.nextRight = nextRight;
5267 >            super(p, b, i, f, t); this.nextRight = nextRight;
5268              this.reducer = reducer;
5269          }
5270          public final Map.Entry<K,V> getRawResult() { return result; }
5271 <        @SuppressWarnings("unchecked") public final void compute() {
5271 >        public final void compute() {
5272              final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5273              if ((reducer = this.reducer) != null) {
5274 <                for (int b; (b = preSplit()) > 0;)
5274 >                for (int i = baseIndex, f, h; batch > 0 &&
5275 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5276 >                    addToPendingCount(1);
5277                      (rights = new ReduceEntriesTask<K,V>
5278 <                     (map, this, b, rights, reducer)).fork();
5279 <                Map.Entry<K,V> r = null;
6042 <                V v;
6043 <                while ((v = advance()) != null) {
6044 <                    Map.Entry<K,V> u = entryFor((K)nextKey, v);
6045 <                    r = (r == null) ? u : reducer.apply(r, u);
5278 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5279 >                      rights, reducer)).fork();
5280                  }
5281 +                Map.Entry<K,V> r = null;
5282 +                for (Node<K,V> p; (p = advance()) != null; )
5283 +                    r = (r == null) ? p : reducer.apply(r, p);
5284                  result = r;
5285                  CountedCompleter<?> c;
5286                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5287 <                    ReduceEntriesTask<K,V>
5287 >                    @SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5288                          t = (ReduceEntriesTask<K,V>)c,
5289                          s = t.rights;
5290                      while (s != null) {
# Line 6062 | Line 5299 | public class ConcurrentHashMapV8<K, V>
5299          }
5300      }
5301  
5302 <    @SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
5303 <        extends Traverser<K,V,U> {
5302 >    @SuppressWarnings("serial")
5303 >    static final class MapReduceKeysTask<K,V,U>
5304 >        extends BulkTask<K,V,U> {
5305          final Fun<? super K, ? extends U> transformer;
5306          final BiFun<? super U, ? super U, ? extends U> reducer;
5307          U result;
5308          MapReduceKeysTask<K,V,U> rights, nextRight;
5309          MapReduceKeysTask
5310 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5310 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5311               MapReduceKeysTask<K,V,U> nextRight,
5312               Fun<? super K, ? extends U> transformer,
5313               BiFun<? super U, ? super U, ? extends U> reducer) {
5314 <            super(m, p, b); this.nextRight = nextRight;
5314 >            super(p, b, i, f, t); this.nextRight = nextRight;
5315              this.transformer = transformer;
5316              this.reducer = reducer;
5317          }
5318          public final U getRawResult() { return result; }
5319 <        @SuppressWarnings("unchecked") public final void compute() {
5319 >        public final void compute() {
5320              final Fun<? super K, ? extends U> transformer;
5321              final BiFun<? super U, ? super U, ? extends U> reducer;
5322              if ((transformer = this.transformer) != null &&
5323                  (reducer = this.reducer) != null) {
5324 <                for (int b; (b = preSplit()) > 0;)
5324 >                for (int i = baseIndex, f, h; batch > 0 &&
5325 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5326 >                    addToPendingCount(1);
5327                      (rights = new MapReduceKeysTask<K,V,U>
5328 <                     (map, this, b, rights, transformer, reducer)).fork();
5329 <                U r = null, u;
5330 <                while (advance() != null) {
5331 <                    if ((u = transformer.apply((K)nextKey)) != null)
5328 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5329 >                      rights, transformer, reducer)).fork();
5330 >                }
5331 >                U r = null;
5332 >                for (Node<K,V> p; (p = advance()) != null; ) {
5333 >                    U u;
5334 >                    if ((u = transformer.apply(p.key)) != null)
5335                          r = (r == null) ? u : reducer.apply(r, u);
5336                  }
5337                  result = r;
5338                  CountedCompleter<?> c;
5339                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5340 <                    MapReduceKeysTask<K,V,U>
5340 >                    @SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5341                          t = (MapReduceKeysTask<K,V,U>)c,
5342                          s = t.rights;
5343                      while (s != null) {
# Line 6109 | Line 5352 | public class ConcurrentHashMapV8<K, V>
5352          }
5353      }
5354  
5355 <    @SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
5356 <        extends Traverser<K,V,U> {
5355 >    @SuppressWarnings("serial")
5356 >    static final class MapReduceValuesTask<K,V,U>
5357 >        extends BulkTask<K,V,U> {
5358          final Fun<? super V, ? extends U> transformer;
5359          final BiFun<? super U, ? super U, ? extends U> reducer;
5360          U result;
5361          MapReduceValuesTask<K,V,U> rights, nextRight;
5362          MapReduceValuesTask
5363 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5363 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5364               MapReduceValuesTask<K,V,U> nextRight,
5365               Fun<? super V, ? extends U> transformer,
5366               BiFun<? super U, ? super U, ? extends U> reducer) {
5367 <            super(m, p, b); this.nextRight = nextRight;
5367 >            super(p, b, i, f, t); this.nextRight = nextRight;
5368              this.transformer = transformer;
5369              this.reducer = reducer;
5370          }
5371          public final U getRawResult() { return result; }
5372 <        @SuppressWarnings("unchecked") public final void compute() {
5372 >        public final void compute() {
5373              final Fun<? super V, ? extends U> transformer;
5374              final BiFun<? super U, ? super U, ? extends U> reducer;
5375              if ((transformer = this.transformer) != null &&
5376                  (reducer = this.reducer) != null) {
5377 <                for (int b; (b = preSplit()) > 0;)
5377 >                for (int i = baseIndex, f, h; batch > 0 &&
5378 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5379 >                    addToPendingCount(1);
5380                      (rights = new MapReduceValuesTask<K,V,U>
5381 <                     (map, this, b, rights, transformer, reducer)).fork();
5382 <                U r = null, u;
5383 <                V v;
5384 <                while ((v = advance()) != null) {
5385 <                    if ((u = transformer.apply(v)) != null)
5381 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5382 >                      rights, transformer, reducer)).fork();
5383 >                }
5384 >                U r = null;
5385 >                for (Node<K,V> p; (p = advance()) != null; ) {
5386 >                    U u;
5387 >                    if ((u = transformer.apply(p.val)) != null)
5388                          r = (r == null) ? u : reducer.apply(r, u);
5389                  }
5390                  result = r;
5391                  CountedCompleter<?> c;
5392                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5393 <                    MapReduceValuesTask<K,V,U>
5393 >                    @SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5394                          t = (MapReduceValuesTask<K,V,U>)c,
5395                          s = t.rights;
5396                      while (s != null) {
# Line 6157 | Line 5405 | public class ConcurrentHashMapV8<K, V>
5405          }
5406      }
5407  
5408 <    @SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
5409 <        extends Traverser<K,V,U> {
5408 >    @SuppressWarnings("serial")
5409 >    static final class MapReduceEntriesTask<K,V,U>
5410 >        extends BulkTask<K,V,U> {
5411          final Fun<Map.Entry<K,V>, ? extends U> transformer;
5412          final BiFun<? super U, ? super U, ? extends U> reducer;
5413          U result;
5414          MapReduceEntriesTask<K,V,U> rights, nextRight;
5415          MapReduceEntriesTask
5416 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5416 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5417               MapReduceEntriesTask<K,V,U> nextRight,
5418               Fun<Map.Entry<K,V>, ? extends U> transformer,
5419               BiFun<? super U, ? super U, ? extends U> reducer) {
5420 <            super(m, p, b); this.nextRight = nextRight;
5420 >            super(p, b, i, f, t); this.nextRight = nextRight;
5421              this.transformer = transformer;
5422              this.reducer = reducer;
5423          }
5424          public final U getRawResult() { return result; }
5425 <        @SuppressWarnings("unchecked") public final void compute() {
5425 >        public final void compute() {
5426              final Fun<Map.Entry<K,V>, ? extends U> transformer;
5427              final BiFun<? super U, ? super U, ? extends U> reducer;
5428              if ((transformer = this.transformer) != null &&
5429                  (reducer = this.reducer) != null) {
5430 <                for (int b; (b = preSplit()) > 0;)
5430 >                for (int i = baseIndex, f, h; batch > 0 &&
5431 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5432 >                    addToPendingCount(1);
5433                      (rights = new MapReduceEntriesTask<K,V,U>
5434 <                     (map, this, b, rights, transformer, reducer)).fork();
5435 <                U r = null, u;
5436 <                V v;
5437 <                while ((v = advance()) != null) {
5438 <                    if ((u = transformer.apply(entryFor((K)nextKey,
5439 <                                                        v))) != null)
5434 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5435 >                      rights, transformer, reducer)).fork();
5436 >                }
5437 >                U r = null;
5438 >                for (Node<K,V> p; (p = advance()) != null; ) {
5439 >                    U u;
5440 >                    if ((u = transformer.apply(p)) != null)
5441                          r = (r == null) ? u : reducer.apply(r, u);
5442                  }
5443                  result = r;
5444                  CountedCompleter<?> c;
5445                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5446 <                    MapReduceEntriesTask<K,V,U>
5446 >                    @SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5447                          t = (MapReduceEntriesTask<K,V,U>)c,
5448                          s = t.rights;
5449                      while (s != null) {
# Line 6206 | Line 5458 | public class ConcurrentHashMapV8<K, V>
5458          }
5459      }
5460  
5461 <    @SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
5462 <        extends Traverser<K,V,U> {
5461 >    @SuppressWarnings("serial")
5462 >    static final class MapReduceMappingsTask<K,V,U>
5463 >        extends BulkTask<K,V,U> {
5464          final BiFun<? super K, ? super V, ? extends U> transformer;
5465          final BiFun<? super U, ? super U, ? extends U> reducer;
5466          U result;
5467          MapReduceMappingsTask<K,V,U> rights, nextRight;
5468          MapReduceMappingsTask
5469 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5469 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5470               MapReduceMappingsTask<K,V,U> nextRight,
5471               BiFun<? super K, ? super V, ? extends U> transformer,
5472               BiFun<? super U, ? super U, ? extends U> reducer) {
5473 <            super(m, p, b); this.nextRight = nextRight;
5473 >            super(p, b, i, f, t); this.nextRight = nextRight;
5474              this.transformer = transformer;
5475              this.reducer = reducer;
5476          }
5477          public final U getRawResult() { return result; }
5478 <        @SuppressWarnings("unchecked") public final void compute() {
5478 >        public final void compute() {
5479              final BiFun<? super K, ? super V, ? extends U> transformer;
5480              final BiFun<? super U, ? super U, ? extends U> reducer;
5481              if ((transformer = this.transformer) != null &&
5482                  (reducer = this.reducer) != null) {
5483 <                for (int b; (b = preSplit()) > 0;)
5483 >                for (int i = baseIndex, f, h; batch > 0 &&
5484 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5485 >                    addToPendingCount(1);
5486                      (rights = new MapReduceMappingsTask<K,V,U>
5487 <                     (map, this, b, rights, transformer, reducer)).fork();
5488 <                U r = null, u;
5489 <                V v;
5490 <                while ((v = advance()) != null) {
5491 <                    if ((u = transformer.apply((K)nextKey, v)) != null)
5487 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5488 >                      rights, transformer, reducer)).fork();
5489 >                }
5490 >                U r = null;
5491 >                for (Node<K,V> p; (p = advance()) != null; ) {
5492 >                    U u;
5493 >                    if ((u = transformer.apply(p.key, p.val)) != null)
5494                          r = (r == null) ? u : reducer.apply(r, u);
5495                  }
5496                  result = r;
5497                  CountedCompleter<?> c;
5498                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5499 <                    MapReduceMappingsTask<K,V,U>
5499 >                    @SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5500                          t = (MapReduceMappingsTask<K,V,U>)c,
5501                          s = t.rights;
5502                      while (s != null) {
# Line 6254 | Line 5511 | public class ConcurrentHashMapV8<K, V>
5511          }
5512      }
5513  
5514 <    @SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
5515 <        extends Traverser<K,V,Double> {
5514 >    @SuppressWarnings("serial")
5515 >    static final class MapReduceKeysToDoubleTask<K,V>
5516 >        extends BulkTask<K,V,Double> {
5517          final ObjectToDouble<? super K> transformer;
5518          final DoubleByDoubleToDouble reducer;
5519          final double basis;
5520          double result;
5521          MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5522          MapReduceKeysToDoubleTask
5523 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5523 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5524               MapReduceKeysToDoubleTask<K,V> nextRight,
5525               ObjectToDouble<? super K> transformer,
5526               double basis,
5527               DoubleByDoubleToDouble reducer) {
5528 <            super(m, p, b); this.nextRight = nextRight;
5528 >            super(p, b, i, f, t); this.nextRight = nextRight;
5529              this.transformer = transformer;
5530              this.basis = basis; this.reducer = reducer;
5531          }
5532          public final Double getRawResult() { return result; }
5533 <        @SuppressWarnings("unchecked") public final void compute() {
5533 >        public final void compute() {
5534              final ObjectToDouble<? super K> transformer;
5535              final DoubleByDoubleToDouble reducer;
5536              if ((transformer = this.transformer) != null &&
5537                  (reducer = this.reducer) != null) {
5538                  double r = this.basis;
5539 <                for (int b; (b = preSplit()) > 0;)
5539 >                for (int i = baseIndex, f, h; batch > 0 &&
5540 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5541 >                    addToPendingCount(1);
5542                      (rights = new MapReduceKeysToDoubleTask<K,V>
5543 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5544 <                while (advance() != null)
5545 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5543 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5544 >                      rights, transformer, r, reducer)).fork();
5545 >                }
5546 >                for (Node<K,V> p; (p = advance()) != null; )
5547 >                    r = reducer.apply(r, transformer.apply(p.key));
5548                  result = r;
5549                  CountedCompleter<?> c;
5550                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5551 <                    MapReduceKeysToDoubleTask<K,V>
5551 >                    @SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5552                          t = (MapReduceKeysToDoubleTask<K,V>)c,
5553                          s = t.rights;
5554                      while (s != null) {
# Line 6298 | Line 5560 | public class ConcurrentHashMapV8<K, V>
5560          }
5561      }
5562  
5563 <    @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
5564 <        extends Traverser<K,V,Double> {
5563 >    @SuppressWarnings("serial")
5564 >    static final class MapReduceValuesToDoubleTask<K,V>
5565 >        extends BulkTask<K,V,Double> {
5566          final ObjectToDouble<? super V> transformer;
5567          final DoubleByDoubleToDouble reducer;
5568          final double basis;
5569          double result;
5570          MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5571          MapReduceValuesToDoubleTask
5572 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5572 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5573               MapReduceValuesToDoubleTask<K,V> nextRight,
5574               ObjectToDouble<? super V> transformer,
5575               double basis,
5576               DoubleByDoubleToDouble reducer) {
5577 <            super(m, p, b); this.nextRight = nextRight;
5577 >            super(p, b, i, f, t); this.nextRight = nextRight;
5578              this.transformer = transformer;
5579              this.basis = basis; this.reducer = reducer;
5580          }
5581          public final Double getRawResult() { return result; }
5582 <        @SuppressWarnings("unchecked") public final void compute() {
5582 >        public final void compute() {
5583              final ObjectToDouble<? super V> transformer;
5584              final DoubleByDoubleToDouble reducer;
5585              if ((transformer = this.transformer) != null &&
5586                  (reducer = this.reducer) != null) {
5587                  double r = this.basis;
5588 <                for (int b; (b = preSplit()) > 0;)
5588 >                for (int i = baseIndex, f, h; batch > 0 &&
5589 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5590 >                    addToPendingCount(1);
5591                      (rights = new MapReduceValuesToDoubleTask<K,V>
5592 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5593 <                V v;
5594 <                while ((v = advance()) != null)
5595 <                    r = reducer.apply(r, transformer.apply(v));
5592 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5593 >                      rights, transformer, r, reducer)).fork();
5594 >                }
5595 >                for (Node<K,V> p; (p = advance()) != null; )
5596 >                    r = reducer.apply(r, transformer.apply(p.val));
5597                  result = r;
5598                  CountedCompleter<?> c;
5599                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5600 <                    MapReduceValuesToDoubleTask<K,V>
5600 >                    @SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5601                          t = (MapReduceValuesToDoubleTask<K,V>)c,
5602                          s = t.rights;
5603                      while (s != null) {
# Line 6343 | Line 5609 | public class ConcurrentHashMapV8<K, V>
5609          }
5610      }
5611  
5612 <    @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
5613 <        extends Traverser<K,V,Double> {
5612 >    @SuppressWarnings("serial")
5613 >    static final class MapReduceEntriesToDoubleTask<K,V>
5614 >        extends BulkTask<K,V,Double> {
5615          final ObjectToDouble<Map.Entry<K,V>> transformer;
5616          final DoubleByDoubleToDouble reducer;
5617          final double basis;
5618          double result;
5619          MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5620          MapReduceEntriesToDoubleTask
5621 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5621 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5622               MapReduceEntriesToDoubleTask<K,V> nextRight,
5623               ObjectToDouble<Map.Entry<K,V>> transformer,
5624               double basis,
5625               DoubleByDoubleToDouble reducer) {
5626 <            super(m, p, b); this.nextRight = nextRight;
5626 >            super(p, b, i, f, t); this.nextRight = nextRight;
5627              this.transformer = transformer;
5628              this.basis = basis; this.reducer = reducer;
5629          }
5630          public final Double getRawResult() { return result; }
5631 <        @SuppressWarnings("unchecked") public final void compute() {
5631 >        public final void compute() {
5632              final ObjectToDouble<Map.Entry<K,V>> transformer;
5633              final DoubleByDoubleToDouble reducer;
5634              if ((transformer = this.transformer) != null &&
5635                  (reducer = this.reducer) != null) {
5636                  double r = this.basis;
5637 <                for (int b; (b = preSplit()) > 0;)
5637 >                for (int i = baseIndex, f, h; batch > 0 &&
5638 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5639 >                    addToPendingCount(1);
5640                      (rights = new MapReduceEntriesToDoubleTask<K,V>
5641 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5642 <                V v;
5643 <                while ((v = advance()) != null)
5644 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey,
5645 <                                                                    v)));
5641 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5642 >                      rights, transformer, r, reducer)).fork();
5643 >                }
5644 >                for (Node<K,V> p; (p = advance()) != null; )
5645 >                    r = reducer.apply(r, transformer.apply(p));
5646                  result = r;
5647                  CountedCompleter<?> c;
5648                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5649 <                    MapReduceEntriesToDoubleTask<K,V>
5649 >                    @SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5650                          t = (MapReduceEntriesToDoubleTask<K,V>)c,
5651                          s = t.rights;
5652                      while (s != null) {
# Line 6389 | Line 5658 | public class ConcurrentHashMapV8<K, V>
5658          }
5659      }
5660  
5661 <    @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
5662 <        extends Traverser<K,V,Double> {
5661 >    @SuppressWarnings("serial")
5662 >    static final class MapReduceMappingsToDoubleTask<K,V>
5663 >        extends BulkTask<K,V,Double> {
5664          final ObjectByObjectToDouble<? super K, ? super V> transformer;
5665          final DoubleByDoubleToDouble reducer;
5666          final double basis;
5667          double result;
5668          MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5669          MapReduceMappingsToDoubleTask
5670 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5670 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5671               MapReduceMappingsToDoubleTask<K,V> nextRight,
5672               ObjectByObjectToDouble<? super K, ? super V> transformer,
5673               double basis,
5674               DoubleByDoubleToDouble reducer) {
5675 <            super(m, p, b); this.nextRight = nextRight;
5675 >            super(p, b, i, f, t); this.nextRight = nextRight;
5676              this.transformer = transformer;
5677              this.basis = basis; this.reducer = reducer;
5678          }
5679          public final Double getRawResult() { return result; }
5680 <        @SuppressWarnings("unchecked") public final void compute() {
5680 >        public final void compute() {
5681              final ObjectByObjectToDouble<? super K, ? super V> transformer;
5682              final DoubleByDoubleToDouble reducer;
5683              if ((transformer = this.transformer) != null &&
5684                  (reducer = this.reducer) != null) {
5685                  double r = this.basis;
5686 <                for (int b; (b = preSplit()) > 0;)
5686 >                for (int i = baseIndex, f, h; batch > 0 &&
5687 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5688 >                    addToPendingCount(1);
5689                      (rights = new MapReduceMappingsToDoubleTask<K,V>
5690 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5691 <                V v;
5692 <                while ((v = advance()) != null)
5693 <                    r = reducer.apply(r, transformer.apply((K)nextKey, v));
5690 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5691 >                      rights, transformer, r, reducer)).fork();
5692 >                }
5693 >                for (Node<K,V> p; (p = advance()) != null; )
5694 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
5695                  result = r;
5696                  CountedCompleter<?> c;
5697                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5698 <                    MapReduceMappingsToDoubleTask<K,V>
5698 >                    @SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5699                          t = (MapReduceMappingsToDoubleTask<K,V>)c,
5700                          s = t.rights;
5701                      while (s != null) {
# Line 6434 | Line 5707 | public class ConcurrentHashMapV8<K, V>
5707          }
5708      }
5709  
5710 <    @SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
5711 <        extends Traverser<K,V,Long> {
5710 >    @SuppressWarnings("serial")
5711 >    static final class MapReduceKeysToLongTask<K,V>
5712 >        extends BulkTask<K,V,Long> {
5713          final ObjectToLong<? super K> transformer;
5714          final LongByLongToLong reducer;
5715          final long basis;
5716          long result;
5717          MapReduceKeysToLongTask<K,V> rights, nextRight;
5718          MapReduceKeysToLongTask
5719 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5719 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5720               MapReduceKeysToLongTask<K,V> nextRight,
5721               ObjectToLong<? super K> transformer,
5722               long basis,
5723               LongByLongToLong reducer) {
5724 <            super(m, p, b); this.nextRight = nextRight;
5724 >            super(p, b, i, f, t); this.nextRight = nextRight;
5725              this.transformer = transformer;
5726              this.basis = basis; this.reducer = reducer;
5727          }
5728          public final Long getRawResult() { return result; }
5729 <        @SuppressWarnings("unchecked") public final void compute() {
5729 >        public final void compute() {
5730              final ObjectToLong<? super K> transformer;
5731              final LongByLongToLong reducer;
5732              if ((transformer = this.transformer) != null &&
5733                  (reducer = this.reducer) != null) {
5734                  long r = this.basis;
5735 <                for (int b; (b = preSplit()) > 0;)
5735 >                for (int i = baseIndex, f, h; batch > 0 &&
5736 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5737 >                    addToPendingCount(1);
5738                      (rights = new MapReduceKeysToLongTask<K,V>
5739 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5740 <                while (advance() != null)
5741 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5739 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5740 >                      rights, transformer, r, reducer)).fork();
5741 >                }
5742 >                for (Node<K,V> p; (p = advance()) != null; )
5743 >                    r = reducer.apply(r, transformer.apply(p.key));
5744                  result = r;
5745                  CountedCompleter<?> c;
5746                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5747 <                    MapReduceKeysToLongTask<K,V>
5747 >                    @SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5748                          t = (MapReduceKeysToLongTask<K,V>)c,
5749                          s = t.rights;
5750                      while (s != null) {
# Line 6478 | Line 5756 | public class ConcurrentHashMapV8<K, V>
5756          }
5757      }
5758  
5759 <    @SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
5760 <        extends Traverser<K,V,Long> {
5759 >    @SuppressWarnings("serial")
5760 >    static final class MapReduceValuesToLongTask<K,V>
5761 >        extends BulkTask<K,V,Long> {
5762          final ObjectToLong<? super V> transformer;
5763          final LongByLongToLong reducer;
5764          final long basis;
5765          long result;
5766          MapReduceValuesToLongTask<K,V> rights, nextRight;
5767          MapReduceValuesToLongTask
5768 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5768 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5769               MapReduceValuesToLongTask<K,V> nextRight,
5770               ObjectToLong<? super V> transformer,
5771               long basis,
5772               LongByLongToLong reducer) {
5773 <            super(m, p, b); this.nextRight = nextRight;
5773 >            super(p, b, i, f, t); this.nextRight = nextRight;
5774              this.transformer = transformer;
5775              this.basis = basis; this.reducer = reducer;
5776          }
5777          public final Long getRawResult() { return result; }
5778 <        @SuppressWarnings("unchecked") public final void compute() {
5778 >        public final void compute() {
5779              final ObjectToLong<? super V> transformer;
5780              final LongByLongToLong reducer;
5781              if ((transformer = this.transformer) != null &&
5782                  (reducer = this.reducer) != null) {
5783                  long r = this.basis;
5784 <                for (int b; (b = preSplit()) > 0;)
5784 >                for (int i = baseIndex, f, h; batch > 0 &&
5785 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5786 >                    addToPendingCount(1);
5787                      (rights = new MapReduceValuesToLongTask<K,V>
5788 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5789 <                V v;
5790 <                while ((v = advance()) != null)
5791 <                    r = reducer.apply(r, transformer.apply(v));
5788 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5789 >                      rights, transformer, r, reducer)).fork();
5790 >                }
5791 >                for (Node<K,V> p; (p = advance()) != null; )
5792 >                    r = reducer.apply(r, transformer.apply(p.val));
5793                  result = r;
5794                  CountedCompleter<?> c;
5795                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5796 <                    MapReduceValuesToLongTask<K,V>
5796 >                    @SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5797                          t = (MapReduceValuesToLongTask<K,V>)c,
5798                          s = t.rights;
5799                      while (s != null) {
# Line 6523 | Line 5805 | public class ConcurrentHashMapV8<K, V>
5805          }
5806      }
5807  
5808 <    @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
5809 <        extends Traverser<K,V,Long> {
5808 >    @SuppressWarnings("serial")
5809 >    static final class MapReduceEntriesToLongTask<K,V>
5810 >        extends BulkTask<K,V,Long> {
5811          final ObjectToLong<Map.Entry<K,V>> transformer;
5812          final LongByLongToLong reducer;
5813          final long basis;
5814          long result;
5815          MapReduceEntriesToLongTask<K,V> rights, nextRight;
5816          MapReduceEntriesToLongTask
5817 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5817 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5818               MapReduceEntriesToLongTask<K,V> nextRight,
5819               ObjectToLong<Map.Entry<K,V>> transformer,
5820               long basis,
5821               LongByLongToLong reducer) {
5822 <            super(m, p, b); this.nextRight = nextRight;
5822 >            super(p, b, i, f, t); this.nextRight = nextRight;
5823              this.transformer = transformer;
5824              this.basis = basis; this.reducer = reducer;
5825          }
5826          public final Long getRawResult() { return result; }
5827 <        @SuppressWarnings("unchecked") public final void compute() {
5827 >        public final void compute() {
5828              final ObjectToLong<Map.Entry<K,V>> transformer;
5829              final LongByLongToLong reducer;
5830              if ((transformer = this.transformer) != null &&
5831                  (reducer = this.reducer) != null) {
5832                  long r = this.basis;
5833 <                for (int b; (b = preSplit()) > 0;)
5833 >                for (int i = baseIndex, f, h; batch > 0 &&
5834 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5835 >                    addToPendingCount(1);
5836                      (rights = new MapReduceEntriesToLongTask<K,V>
5837 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5838 <                V v;
5839 <                while ((v = advance()) != null)
5840 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey,
5841 <                                                                    v)));
5837 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5838 >                      rights, transformer, r, reducer)).fork();
5839 >                }
5840 >                for (Node<K,V> p; (p = advance()) != null; )
5841 >                    r = reducer.apply(r, transformer.apply(p));
5842                  result = r;
5843                  CountedCompleter<?> c;
5844                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5845 <                    MapReduceEntriesToLongTask<K,V>
5845 >                    @SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5846                          t = (MapReduceEntriesToLongTask<K,V>)c,
5847                          s = t.rights;
5848                      while (s != null) {
# Line 6569 | Line 5854 | public class ConcurrentHashMapV8<K, V>
5854          }
5855      }
5856  
5857 <    @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
5858 <        extends Traverser<K,V,Long> {
5857 >    @SuppressWarnings("serial")
5858 >    static final class MapReduceMappingsToLongTask<K,V>
5859 >        extends BulkTask<K,V,Long> {
5860          final ObjectByObjectToLong<? super K, ? super V> transformer;
5861          final LongByLongToLong reducer;
5862          final long basis;
5863          long result;
5864          MapReduceMappingsToLongTask<K,V> rights, nextRight;
5865          MapReduceMappingsToLongTask
5866 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5866 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5867               MapReduceMappingsToLongTask<K,V> nextRight,
5868               ObjectByObjectToLong<? super K, ? super V> transformer,
5869               long basis,
5870               LongByLongToLong reducer) {
5871 <            super(m, p, b); this.nextRight = nextRight;
5871 >            super(p, b, i, f, t); this.nextRight = nextRight;
5872              this.transformer = transformer;
5873              this.basis = basis; this.reducer = reducer;
5874          }
5875          public final Long getRawResult() { return result; }
5876 <        @SuppressWarnings("unchecked") public final void compute() {
5876 >        public final void compute() {
5877              final ObjectByObjectToLong<? super K, ? super V> transformer;
5878              final LongByLongToLong reducer;
5879              if ((transformer = this.transformer) != null &&
5880                  (reducer = this.reducer) != null) {
5881                  long r = this.basis;
5882 <                for (int b; (b = preSplit()) > 0;)
5882 >                for (int i = baseIndex, f, h; batch > 0 &&
5883 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5884 >                    addToPendingCount(1);
5885                      (rights = new MapReduceMappingsToLongTask<K,V>
5886 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5887 <                V v;
5888 <                while ((v = advance()) != null)
5889 <                    r = reducer.apply(r, transformer.apply((K)nextKey, v));
5886 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5887 >                      rights, transformer, r, reducer)).fork();
5888 >                }
5889 >                for (Node<K,V> p; (p = advance()) != null; )
5890 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
5891                  result = r;
5892                  CountedCompleter<?> c;
5893                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5894 <                    MapReduceMappingsToLongTask<K,V>
5894 >                    @SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5895                          t = (MapReduceMappingsToLongTask<K,V>)c,
5896                          s = t.rights;
5897                      while (s != null) {
# Line 6614 | Line 5903 | public class ConcurrentHashMapV8<K, V>
5903          }
5904      }
5905  
5906 <    @SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
5907 <        extends Traverser<K,V,Integer> {
5906 >    @SuppressWarnings("serial")
5907 >    static final class MapReduceKeysToIntTask<K,V>
5908 >        extends BulkTask<K,V,Integer> {
5909          final ObjectToInt<? super K> transformer;
5910          final IntByIntToInt reducer;
5911          final int basis;
5912          int result;
5913          MapReduceKeysToIntTask<K,V> rights, nextRight;
5914          MapReduceKeysToIntTask
5915 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5915 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5916               MapReduceKeysToIntTask<K,V> nextRight,
5917               ObjectToInt<? super K> transformer,
5918               int basis,
5919               IntByIntToInt reducer) {
5920 <            super(m, p, b); this.nextRight = nextRight;
5920 >            super(p, b, i, f, t); this.nextRight = nextRight;
5921              this.transformer = transformer;
5922              this.basis = basis; this.reducer = reducer;
5923          }
5924          public final Integer getRawResult() { return result; }
5925 <        @SuppressWarnings("unchecked") public final void compute() {
5925 >        public final void compute() {
5926              final ObjectToInt<? super K> transformer;
5927              final IntByIntToInt reducer;
5928              if ((transformer = this.transformer) != null &&
5929                  (reducer = this.reducer) != null) {
5930                  int r = this.basis;
5931 <                for (int b; (b = preSplit()) > 0;)
5931 >                for (int i = baseIndex, f, h; batch > 0 &&
5932 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5933 >                    addToPendingCount(1);
5934                      (rights = new MapReduceKeysToIntTask<K,V>
5935 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5936 <                while (advance() != null)
5937 <                    r = reducer.apply(r, transformer.apply((K)nextKey));
5935 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5936 >                      rights, transformer, r, reducer)).fork();
5937 >                }
5938 >                for (Node<K,V> p; (p = advance()) != null; )
5939 >                    r = reducer.apply(r, transformer.apply(p.key));
5940                  result = r;
5941                  CountedCompleter<?> c;
5942                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5943 <                    MapReduceKeysToIntTask<K,V>
5943 >                    @SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5944                          t = (MapReduceKeysToIntTask<K,V>)c,
5945                          s = t.rights;
5946                      while (s != null) {
# Line 6658 | Line 5952 | public class ConcurrentHashMapV8<K, V>
5952          }
5953      }
5954  
5955 <    @SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
5956 <        extends Traverser<K,V,Integer> {
5955 >    @SuppressWarnings("serial")
5956 >    static final class MapReduceValuesToIntTask<K,V>
5957 >        extends BulkTask<K,V,Integer> {
5958          final ObjectToInt<? super V> transformer;
5959          final IntByIntToInt reducer;
5960          final int basis;
5961          int result;
5962          MapReduceValuesToIntTask<K,V> rights, nextRight;
5963          MapReduceValuesToIntTask
5964 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
5964 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5965               MapReduceValuesToIntTask<K,V> nextRight,
5966               ObjectToInt<? super V> transformer,
5967               int basis,
5968               IntByIntToInt reducer) {
5969 <            super(m, p, b); this.nextRight = nextRight;
5969 >            super(p, b, i, f, t); this.nextRight = nextRight;
5970              this.transformer = transformer;
5971              this.basis = basis; this.reducer = reducer;
5972          }
5973          public final Integer getRawResult() { return result; }
5974 <        @SuppressWarnings("unchecked") public final void compute() {
5974 >        public final void compute() {
5975              final ObjectToInt<? super V> transformer;
5976              final IntByIntToInt reducer;
5977              if ((transformer = this.transformer) != null &&
5978                  (reducer = this.reducer) != null) {
5979                  int r = this.basis;
5980 <                for (int b; (b = preSplit()) > 0;)
5980 >                for (int i = baseIndex, f, h; batch > 0 &&
5981 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
5982 >                    addToPendingCount(1);
5983                      (rights = new MapReduceValuesToIntTask<K,V>
5984 <                     (map, this, b, rights, transformer, r, reducer)).fork();
5985 <                V v;
5986 <                while ((v = advance()) != null)
5987 <                    r = reducer.apply(r, transformer.apply(v));
5984 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
5985 >                      rights, transformer, r, reducer)).fork();
5986 >                }
5987 >                for (Node<K,V> p; (p = advance()) != null; )
5988 >                    r = reducer.apply(r, transformer.apply(p.val));
5989                  result = r;
5990                  CountedCompleter<?> c;
5991                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
5992 <                    MapReduceValuesToIntTask<K,V>
5992 >                    @SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5993                          t = (MapReduceValuesToIntTask<K,V>)c,
5994                          s = t.rights;
5995                      while (s != null) {
# Line 6703 | Line 6001 | public class ConcurrentHashMapV8<K, V>
6001          }
6002      }
6003  
6004 <    @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6005 <        extends Traverser<K,V,Integer> {
6004 >    @SuppressWarnings("serial")
6005 >    static final class MapReduceEntriesToIntTask<K,V>
6006 >        extends BulkTask<K,V,Integer> {
6007          final ObjectToInt<Map.Entry<K,V>> transformer;
6008          final IntByIntToInt reducer;
6009          final int basis;
6010          int result;
6011          MapReduceEntriesToIntTask<K,V> rights, nextRight;
6012          MapReduceEntriesToIntTask
6013 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
6013 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6014               MapReduceEntriesToIntTask<K,V> nextRight,
6015               ObjectToInt<Map.Entry<K,V>> transformer,
6016               int basis,
6017               IntByIntToInt reducer) {
6018 <            super(m, p, b); this.nextRight = nextRight;
6018 >            super(p, b, i, f, t); this.nextRight = nextRight;
6019              this.transformer = transformer;
6020              this.basis = basis; this.reducer = reducer;
6021          }
6022          public final Integer getRawResult() { return result; }
6023 <        @SuppressWarnings("unchecked") public final void compute() {
6023 >        public final void compute() {
6024              final ObjectToInt<Map.Entry<K,V>> transformer;
6025              final IntByIntToInt reducer;
6026              if ((transformer = this.transformer) != null &&
6027                  (reducer = this.reducer) != null) {
6028                  int r = this.basis;
6029 <                for (int b; (b = preSplit()) > 0;)
6029 >                for (int i = baseIndex, f, h; batch > 0 &&
6030 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
6031 >                    addToPendingCount(1);
6032                      (rights = new MapReduceEntriesToIntTask<K,V>
6033 <                     (map, this, b, rights, transformer, r, reducer)).fork();
6034 <                V v;
6035 <                while ((v = advance()) != null)
6036 <                    r = reducer.apply(r, transformer.apply(entryFor((K)nextKey,
6037 <                                                                    v)));
6033 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
6034 >                      rights, transformer, r, reducer)).fork();
6035 >                }
6036 >                for (Node<K,V> p; (p = advance()) != null; )
6037 >                    r = reducer.apply(r, transformer.apply(p));
6038                  result = r;
6039                  CountedCompleter<?> c;
6040                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
6041 <                    MapReduceEntriesToIntTask<K,V>
6041 >                    @SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
6042                          t = (MapReduceEntriesToIntTask<K,V>)c,
6043                          s = t.rights;
6044                      while (s != null) {
# Line 6749 | Line 6050 | public class ConcurrentHashMapV8<K, V>
6050          }
6051      }
6052  
6053 <    @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6054 <        extends Traverser<K,V,Integer> {
6053 >    @SuppressWarnings("serial")
6054 >    static final class MapReduceMappingsToIntTask<K,V>
6055 >        extends BulkTask<K,V,Integer> {
6056          final ObjectByObjectToInt<? super K, ? super V> transformer;
6057          final IntByIntToInt reducer;
6058          final int basis;
6059          int result;
6060          MapReduceMappingsToIntTask<K,V> rights, nextRight;
6061          MapReduceMappingsToIntTask
6062 <            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
6062 >            (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6063               MapReduceMappingsToIntTask<K,V> nextRight,
6064               ObjectByObjectToInt<? super K, ? super V> transformer,
6065               int basis,
6066               IntByIntToInt reducer) {
6067 <            super(m, p, b); this.nextRight = nextRight;
6067 >            super(p, b, i, f, t); this.nextRight = nextRight;
6068              this.transformer = transformer;
6069              this.basis = basis; this.reducer = reducer;
6070          }
6071          public final Integer getRawResult() { return result; }
6072 <        @SuppressWarnings("unchecked") public final void compute() {
6072 >        public final void compute() {
6073              final ObjectByObjectToInt<? super K, ? super V> transformer;
6074              final IntByIntToInt reducer;
6075              if ((transformer = this.transformer) != null &&
6076                  (reducer = this.reducer) != null) {
6077                  int r = this.basis;
6078 <                for (int b; (b = preSplit()) > 0;)
6078 >                for (int i = baseIndex, f, h; batch > 0 &&
6079 >                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
6080 >                    addToPendingCount(1);
6081                      (rights = new MapReduceMappingsToIntTask<K,V>
6082 <                     (map, this, b, rights, transformer, r, reducer)).fork();
6083 <                V v;
6084 <                while ((v = advance()) != null)
6085 <                    r = reducer.apply(r, transformer.apply((K)nextKey, v));
6082 >                     (this, batch >>>= 1, baseLimit = h, f, tab,
6083 >                      rights, transformer, r, reducer)).fork();
6084 >                }
6085 >                for (Node<K,V> p; (p = advance()) != null; )
6086 >                    r = reducer.apply(r, transformer.apply(p.key, p.val));
6087                  result = r;
6088                  CountedCompleter<?> c;
6089                  for (c = firstComplete(); c != null; c = c.nextComplete()) {
6090 <                    MapReduceMappingsToIntTask<K,V>
6090 >                    @SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6091                          t = (MapReduceMappingsToIntTask<K,V>)c,
6092                          s = t.rights;
6093                      while (s != null) {
# Line 6794 | Line 6099 | public class ConcurrentHashMapV8<K, V>
6099          }
6100      }
6101  
6102 +    /* ---------------- Counters -------------- */
6103 +
6104 +    // Adapted from LongAdder and Striped64.
6105 +    // See their internal docs for explanation.
6106 +
6107 +    // A padded cell for distributing counts
6108 +    static final class CounterCell {
6109 +        volatile long p0, p1, p2, p3, p4, p5, p6;
6110 +        volatile long value;
6111 +        volatile long q0, q1, q2, q3, q4, q5, q6;
6112 +        CounterCell(long x) { value = x; }
6113 +    }
6114 +
6115 +    /**
6116 +     * Holder for the thread-local hash code determining which
6117 +     * CounterCell to use. The code is initialized via the
6118 +     * counterHashCodeGenerator, but may be moved upon collisions.
6119 +     */
6120 +    static final class CounterHashCode {
6121 +        int code;
6122 +    }
6123 +
6124 +    /**
6125 +     * Generates initial value for per-thread CounterHashCodes.
6126 +     */
6127 +    static final AtomicInteger counterHashCodeGenerator = new AtomicInteger();
6128 +
6129 +    /**
6130 +     * Increment for counterHashCodeGenerator. See class ThreadLocal
6131 +     * for explanation.
6132 +     */
6133 +    static final int SEED_INCREMENT = 0x61c88647;
6134 +
6135 +    /**
6136 +     * Per-thread counter hash codes. Shared across all instances.
6137 +     */
6138 +    static final ThreadLocal<CounterHashCode> threadCounterHashCode =
6139 +        new ThreadLocal<CounterHashCode>();
6140 +
6141 +
6142 +    final long sumCount() {
6143 +        CounterCell[] as = counterCells; CounterCell a;
6144 +        long sum = baseCount;
6145 +        if (as != null) {
6146 +            for (int i = 0; i < as.length; ++i) {
6147 +                if ((a = as[i]) != null)
6148 +                    sum += a.value;
6149 +            }
6150 +        }
6151 +        return sum;
6152 +    }
6153 +
6154 +    // See LongAdder version for explanation
6155 +    private final void fullAddCount(long x, CounterHashCode hc,
6156 +                                    boolean wasUncontended) {
6157 +        int h;
6158 +        if (hc == null) {
6159 +            hc = new CounterHashCode();
6160 +            int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT);
6161 +            h = hc.code = (s == 0) ? 1 : s; // Avoid zero
6162 +            threadCounterHashCode.set(hc);
6163 +        }
6164 +        else
6165 +            h = hc.code;
6166 +        boolean collide = false;                // True if last slot nonempty
6167 +        for (;;) {
6168 +            CounterCell[] as; CounterCell a; int n; long v;
6169 +            if ((as = counterCells) != null && (n = as.length) > 0) {
6170 +                if ((a = as[(n - 1) & h]) == null) {
6171 +                    if (cellsBusy == 0) {            // Try to attach new Cell
6172 +                        CounterCell r = new CounterCell(x); // Optimistic create
6173 +                        if (cellsBusy == 0 &&
6174 +                            U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6175 +                            boolean created = false;
6176 +                            try {               // Recheck under lock
6177 +                                CounterCell[] rs; int m, j;
6178 +                                if ((rs = counterCells) != null &&
6179 +                                    (m = rs.length) > 0 &&
6180 +                                    rs[j = (m - 1) & h] == null) {
6181 +                                    rs[j] = r;
6182 +                                    created = true;
6183 +                                }
6184 +                            } finally {
6185 +                                cellsBusy = 0;
6186 +                            }
6187 +                            if (created)
6188 +                                break;
6189 +                            continue;           // Slot is now non-empty
6190 +                        }
6191 +                    }
6192 +                    collide = false;
6193 +                }
6194 +                else if (!wasUncontended)       // CAS already known to fail
6195 +                    wasUncontended = true;      // Continue after rehash
6196 +                else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
6197 +                    break;
6198 +                else if (counterCells != as || n >= NCPU)
6199 +                    collide = false;            // At max size or stale
6200 +                else if (!collide)
6201 +                    collide = true;
6202 +                else if (cellsBusy == 0 &&
6203 +                         U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6204 +                    try {
6205 +                        if (counterCells == as) {// Expand table unless stale
6206 +                            CounterCell[] rs = new CounterCell[n << 1];
6207 +                            for (int i = 0; i < n; ++i)
6208 +                                rs[i] = as[i];
6209 +                            counterCells = rs;
6210 +                        }
6211 +                    } finally {
6212 +                        cellsBusy = 0;
6213 +                    }
6214 +                    collide = false;
6215 +                    continue;                   // Retry with expanded table
6216 +                }
6217 +                h ^= h << 13;                   // Rehash
6218 +                h ^= h >>> 17;
6219 +                h ^= h << 5;
6220 +            }
6221 +            else if (cellsBusy == 0 && counterCells == as &&
6222 +                     U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
6223 +                boolean init = false;
6224 +                try {                           // Initialize table
6225 +                    if (counterCells == as) {
6226 +                        CounterCell[] rs = new CounterCell[2];
6227 +                        rs[h & 1] = new CounterCell(x);
6228 +                        counterCells = rs;
6229 +                        init = true;
6230 +                    }
6231 +                } finally {
6232 +                    cellsBusy = 0;
6233 +                }
6234 +                if (init)
6235 +                    break;
6236 +            }
6237 +            else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
6238 +                break;                          // Fall back on using base
6239 +        }
6240 +        hc.code = h;                            // Record index for next time
6241 +    }
6242 +
6243      // Unsafe mechanics
6244      private static final sun.misc.Unsafe U;
6245      private static final long SIZECTL;
6246      private static final long TRANSFERINDEX;
6801    private static final long TRANSFERORIGIN;
6247      private static final long BASECOUNT;
6248 <    private static final long COUNTERBUSY;
6248 >    private static final long CELLSBUSY;
6249      private static final long CELLVALUE;
6250      private static final long ABASE;
6251      private static final int ASHIFT;
# Line 6813 | Line 6258 | public class ConcurrentHashMapV8<K, V>
6258                  (k.getDeclaredField("sizeCtl"));
6259              TRANSFERINDEX = U.objectFieldOffset
6260                  (k.getDeclaredField("transferIndex"));
6816            TRANSFERORIGIN = U.objectFieldOffset
6817                (k.getDeclaredField("transferOrigin"));
6261              BASECOUNT = U.objectFieldOffset
6262                  (k.getDeclaredField("baseCount"));
6263 <            COUNTERBUSY = U.objectFieldOffset
6264 <                (k.getDeclaredField("counterBusy"));
6263 >            CELLSBUSY = U.objectFieldOffset
6264 >                (k.getDeclaredField("cellsBusy"));
6265              Class<?> ck = CounterCell.class;
6266              CELLVALUE = U.objectFieldOffset
6267                  (ck.getDeclaredField("value"));
6268 <            Class<?> sc = Node[].class;
6269 <            ABASE = U.arrayBaseOffset(sc);
6270 <            int scale = U.arrayIndexScale(sc);
6268 >            Class<?> ak = Node[].class;
6269 >            ABASE = U.arrayBaseOffset(ak);
6270 >            int scale = U.arrayIndexScale(ak);
6271              if ((scale & (scale - 1)) != 0)
6272                  throw new Error("data type scale not a power of two");
6273              ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);

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