[ViewVC] Diff of: jsr166/jsr166/src/jsr166e/ConcurrentHashMapV8.java

Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents):
Revision 1.31 by jsr166, Tue Oct 25 20:26:37 2011 UTC vs.
Revision 1.81 by dl, Sat Dec 8 14:10:38 2012 UTC

+ */
+package jsr166e;
-<
+import jsr166e.LongAdder;
->
->
+import java.util.Comparator;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.Set;
+import java.util.ConcurrentModificationException;
+import java.util.NoSuchElementException;
+import java.util.concurrent.ConcurrentMap;
-+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.locks.LockSupport;
-+
+import java.util.concurrent.locks.AbstractQueuedSynchronizer;
-+
+import java.util.concurrent.atomic.AtomicReference;
-+
-+
+import java.io.Serializable;
-+
-+
+import java.util.Comparator;
-+
+import java.util.Arrays;
-+
+import java.util.Map;
-+
+import java.util.Set;
-+
+import java.util.Collection;
-+
+import java.util.AbstractMap;
-+
+import java.util.AbstractSet;
-+
+import java.util.AbstractCollection;
-+
+import java.util.Hashtable;
-+
+import java.util.HashMap;
-+
+import java.util.Iterator;
-+
+import java.util.Enumeration;
-+
+import java.util.ConcurrentModificationException;
-+
+import java.util.NoSuchElementException;
-+
+import java.util.concurrent.ConcurrentMap;
-+
+import java.util.concurrent.ThreadLocalRandom;
-+
+import java.util.concurrent.locks.LockSupport;
-+
+import java.util.concurrent.locks.AbstractQueuedSynchronizer;
-+
+import java.util.concurrent.atomic.AtomicReference;
-+
+import java.io.Serializable;
+/**
+ * interoperable with {@code Hashtable} in programs that rely on its
+ * thread safety but not on its synchronization details.
-<
+ * <p> Retrieval operations (including {@code get}) generally do not
->
+ * <p>Retrieval operations (including {@code get}) generally do not
+ * block, so may overlap with update operations (including {@code put}
+ * and {@code remove}). Retrievals reflect the results of the most
+ * recently <em>completed</em> update operations holding upon their
-<
+ * onset.  For aggregate operations such as {@code putAll} and {@code
-<
+ * clear}, concurrent retrievals may reflect insertion or removal of
-<
+ * only some entries.  Similarly, Iterators and Enumerations return
-<
+ * elements reflecting the state of the hash table at some point at or
-<
+ * since the creation of the iterator/enumeration.  They do
-<
+ * <em>not</em> throw {@link ConcurrentModificationException}.
-<
+ * However, iterators are designed to be used by only one thread at a
-<
+ * time.  Bear in mind that the results of aggregate status methods
-<
+ * including {@code size}, {@code isEmpty}, and {@code containsValue}
-<
+ * are typically useful only when a map is not undergoing concurrent
-<
+ * updates in other threads.  Otherwise the results of these methods
-<
+ * reflect transient states that may be adequate for monitoring
-<
+ * or estimation purposes, but not for program control.
->
+ * onset. (More formally, an update operation for a given key bears a
->
+ * <em>happens-before</em> relation with any (non-null) retrieval for
->
+ * that key reporting the updated value.)  For aggregate operations
->
+ * such as {@code putAll} and {@code clear}, concurrent retrievals may
->
+ * reflect insertion or removal of only some entries.  Similarly,
->
+ * Iterators and Enumerations return elements reflecting the state of
->
+ * the hash table at some point at or since the creation of the
->
+ * iterator/enumeration.  They do <em>not</em> throw {@link
->
+ * ConcurrentModificationException}.  However, iterators are designed
->
+ * to be used by only one thread at a time.  Bear in mind that the
->
+ * results of aggregate status methods including {@code size}, {@code
->
+ * isEmpty}, and {@code containsValue} are typically useful only when
->
+ * a map is not undergoing concurrent updates in other threads.
->
+ * Otherwise the results of these methods reflect transient states
->
+ * that may be adequate for monitoring or estimation purposes, but not
->
+ * for program control.
-<
+ * <p> The table is dynamically expanded when there are too many
->
+ * <p>The table is dynamically expanded when there are too many
+ * collisions (i.e., keys that have distinct hash codes but fall into
+ * the same slot modulo the table size), with the expected average
+ * effect of maintaining roughly two bins per mapping (corresponding
+ * {@code hashCode()} is a sure way to slow down performance of any
+ * hash table.
-+
+ * <p>A {@link Set} projection of a ConcurrentHashMapV8 may be created
-+
+ * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
-+
+ * (using {@link #keySet(Object)} when only keys are of interest, and the
-+
+ * mapped values are (perhaps transiently) not used or all take the
-+
+ * same mapping value.
-+
+ *
-+
+ * <p>A ConcurrentHashMapV8 can be used as scalable frequency map (a
-+
+ * form of histogram or multiset) by using {@link LongAdder} values
-+
+ * and initializing via {@link #computeIfAbsent}. For example, to add
-+
+ * a count to a {@code ConcurrentHashMapV8<String,LongAdder> freqs}, you
-+
+ * can use {@code freqs.computeIfAbsent(k -> new
-+
+ * LongAdder()).increment();}
-+
+ *
+ * <p>This class and its views and iterators implement all of the
+ * <em>optional</em> methods of the {@link Map} and {@link Iterator}
+ * interfaces.
-<
+ * <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
->
+ * <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
+ * does <em>not</em> allow {@code null} to be used as a key or value.
-+
+ * <p>ConcurrentHashMapV8s support parallel operations using the {@link
-+
+ * ForkJoinPool#commonPool}. (Tasks that may be used in other contexts
-+
+ * are available in class {@link ForkJoinTasks}). These operations are
-+
+ * designed to be safely, and often sensibly, applied even with maps
-+
+ * that are being concurrently updated by other threads; for example,
-+
+ * when computing a snapshot summary of the values in a shared
-+
+ * registry.  There are three kinds of operation, each with four
-+
+ * forms, accepting functions with Keys, Values, Entries, and (Key,
-+
+ * Value) arguments and/or return values. (The first three forms are
-+
+ * also available via the {@link #keySet()}, {@link #values()} and
-+
+ * {@link #entrySet()} views). Because the elements of a
-+
+ * ConcurrentHashMapV8 are not ordered in any particular way, and may be
-+
+ * processed in different orders in different parallel executions, the
-+
+ * correctness of supplied functions should not depend on any
-+
+ * ordering, or on any other objects or values that may transiently
-+
+ * change while computation is in progress; and except for forEach
-+
+ * actions, should ideally be side-effect-free.
-+
+ *
-+
+ * <ul>
-+
+ * <li> forEach: Perform a given action on each element.
-+
+ * A variant form applies a given transformation on each element
-+
+ * before performing the action.</li>
-+
+ *
-+
+ * <li> search: Return the first available non-null result of
-+
+ * applying a given function on each element; skipping further
-+
+ * search when a result is found.</li>
-+
+ *
-+
+ * <li> reduce: Accumulate each element.  The supplied reduction
-+
+ * function cannot rely on ordering (more formally, it should be
-+
+ * both associative and commutative).  There are five variants:
-+
+ *
-+
+ * <ul>
-+
+ *
-+
+ * <li> Plain reductions. (There is not a form of this method for
-+
+ * (key, value) function arguments since there is no corresponding
-+
+ * return type.)</li>
-+
+ *
-+
+ * <li> Mapped reductions that accumulate the results of a given
-+
+ * function applied to each element.</li>
-+
+ *
-+
+ * <li> Reductions to scalar doubles, longs, and ints, using a
-+
+ * given basis value.</li>
-+
+ *
-+
+ * </li>
-+
+ * </ul>
-+
+ * </ul>
-+
+ *
-+
+ * <p>The concurrency properties of bulk operations follow
-+
+ * from those of ConcurrentHashMapV8: Any non-null result returned
-+
+ * from {@code get(key)} and related access methods bears a
-+
+ * happens-before relation with the associated insertion or
-+
+ * update.  The result of any bulk operation reflects the
-+
+ * composition of these per-element relations (but is not
-+
+ * necessarily atomic with respect to the map as a whole unless it
-+
+ * is somehow known to be quiescent).  Conversely, because keys
-+
+ * and values in the map are never null, null serves as a reliable
-+
+ * atomic indicator of the current lack of any result.  To
-+
+ * maintain this property, null serves as an implicit basis for
-+
+ * all non-scalar reduction operations. For the double, long, and
-+
+ * int versions, the basis should be one that, when combined with
-+
+ * any other value, returns that other value (more formally, it
-+
+ * should be the identity element for the reduction). Most common
-+
+ * reductions have these properties; for example, computing a sum
-+
+ * with basis 0 or a minimum with basis MAX_VALUE.
-+
+ *
-+
+ * <p>Search and transformation functions provided as arguments
-+
+ * should similarly return null to indicate the lack of any result
-+
+ * (in which case it is not used). In the case of mapped
-+
+ * reductions, this also enables transformations to serve as
-+
+ * filters, returning null (or, in the case of primitive
-+
+ * specializations, the identity basis) if the element should not
-+
+ * be combined. You can create compound transformations and
-+
+ * filterings by composing them yourself under this "null means
-+
+ * there is nothing there now" rule before using them in search or
-+
+ * reduce operations.
-+
+ *
-+
+ * <p>Methods accepting and/or returning Entry arguments maintain
-+
+ * key-value associations. They may be useful for example when
-+
+ * finding the key for the greatest value. Note that "plain" Entry
-+
+ * arguments can be supplied using {@code new
-+
+ * AbstractMap.SimpleEntry(k,v)}.
-+
+ *
-+
+ * <p>Bulk operations may complete abruptly, throwing an
-+
+ * exception encountered in the application of a supplied
-+
+ * function. Bear in mind when handling such exceptions that other
-+
+ * concurrently executing functions could also have thrown
-+
+ * exceptions, or would have done so if the first exception had
-+
+ * not occurred.
-+
+ *
-+
+ * <p>Parallel speedups for bulk operations compared to sequential
-+
+ * processing are common but not guaranteed.  Operations involving
-+
+ * brief functions on small maps may execute more slowly than
-+
+ * sequential loops if the underlying work to parallelize the
-+
+ * computation is more expensive than the computation itself.
-+
+ * Similarly, parallelization may not lead to much actual parallelism
-+
+ * if all processors are busy performing unrelated tasks.
-+
+ *
-+
+ * <p>All arguments to all task methods must be non-null.
-+
+ *
-+
+ * <p><em>jsr166e note: During transition, this class
-+
+ * uses nested functional interfaces with different names but the
-+
+ * same forms as those expected for JDK8.</em>
-+
+ *
+ * <p>This class is a member of the
+ * <a href="{@docRoot}/../technotes/guides/collections/index.html">
+ * Java Collections Framework</a>.
-–
+ * <p><em>jsr166e note: This class is a candidate replacement for
-–
+ * java.util.concurrent.ConcurrentHashMap.<em>
-–
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <K> the type of keys maintained by this map
+ * @param <V> the type of mapped values
+ */
+public class ConcurrentHashMapV8<K, V>
-<
+        implements ConcurrentMap<K, V>, Serializable {
->
+    implements ConcurrentMap<K, V>, Serializable {
+    private static final long serialVersionUID = 7249069246763182397L;
+    /**
-<
+     * A function computing a mapping from the given key to a value.
-<
+     * This is a place-holder for an upcoming JDK8 interface.
->
+     * A partitionable iterator. A Spliterator can be traversed
->
+     * directly, but can also be partitioned (before traversal) by
->
+     * creating another Spliterator that covers a non-overlapping
->
+     * portion of the elements, and so may be amenable to parallel
->
+     * execution.
->
+     *
->
+     * <p>This interface exports a subset of expected JDK8
->
+     * functionality.
->
+     *
->
+     * <p>Sample usage: Here is one (of the several) ways to compute
->
+     * the sum of the values held in a map using the ForkJoin
->
+     * framework. As illustrated here, Spliterators are well suited to
->
+     * designs in which a task repeatedly splits off half its work
->
+     * into forked subtasks until small enough to process directly,
->
+     * and then joins these subtasks. Variants of this style can also
->
+     * be used in completion-based designs.
->
+     *
->
+     * <pre>
->
+     * {@code ConcurrentHashMapV8<String, Long> m = ...
->
+     * // split as if have 8 * parallelism, for load balance
->
+     * int n = m.size();
->
+     * int p = aForkJoinPool.getParallelism() * 8;
->
+     * int split = (n < p)? n : p;
->
+     * long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
->
+     * // ...
->
+     * static class SumValues extends RecursiveTask<Long> {
->
+     *   final Spliterator<Long> s;
->
+     *   final int split;             // split while > 1
->
+     *   final SumValues nextJoin;    // records forked subtasks to join
->
+     *   SumValues(Spliterator<Long> s, int depth, SumValues nextJoin) {
->
+     *     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
->
+     *   }
->
+     *   public Long compute() {
->
+     *     long sum = 0;
->
+     *     SumValues subtasks = null; // fork subtasks
->
+     *     for (int s = split >>> 1; s > 0; s >>>= 1)
->
+     *       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
->
+     *     while (s.hasNext())        // directly process remaining elements
->
+     *       sum += s.next();
->
+     *     for (SumValues t = subtasks; t != null; t = t.nextJoin)
->
+     *       sum += t.join();         // collect subtask results
->
+     *     return sum;
->
+     *   }
->
+     * }
->
+     * }</pre>
+     */
-<
+    public static interface MappingFunction<K, V> {
->
+    public static interface Spliterator<T> extends Iterator<T> {
+        /**
-<
+         * Returns a non-null value for the given key.
->
+         * Returns a Spliterator covering approximately half of the
->
+         * elements, guaranteed not to overlap with those subsequently
->
+         * returned by this Spliterator.  After invoking this method,
->
+         * the current Spliterator will <em>not</em> produce any of
->
+         * the elements of the returned Spliterator, but the two
->
+         * Spliterators together will produce all of the elements that
->
+         * would have been produced by this Spliterator had this
->
+         * method not been called. The exact number of elements
->
+         * produced by the returned Spliterator is not guaranteed, and
->
+         * may be zero (i.e., with {@code hasNext()} reporting {@code
->
+         * false}) if this Spliterator cannot be further split.
-<
+         * @param key the (non-null) key
-<
+         * @return a non-null value
->
+         * @return a Spliterator covering approximately half of the
->
+         * elements
->
+         * @throws IllegalStateException if this Spliterator has
->
+         * already commenced traversing elements
+         */
-<
+        V map(K key);
->
+        Spliterator<T> split();
-–
+    /**
-–
+     * A function computing a new mapping given a key and its current
-–
+     * mapped value (or {@code null} if there is no current
-–
+     * mapping). This is a place-holder for an upcoming JDK8
-–
+     * interface.
-–
+     */
-–
+    public static interface RemappingFunction<K, V> {
-–
+        /**
-–
+         * Returns a new value given a key and its current value.
-–
+         *
-–
+         * @param key the (non-null) key
-–
+         * @param value the current value, or null if there is no mapping
-–
+         * @return a non-null value
-–
+         */
-–
+        V remap(K key, V value);
-–
+    }
+    /*
+     * Overview:
+     * supplying null-checks and casts as needed. This also allows
+     * many of the public methods to be factored into a smaller number
+     * of internal methods (although sadly not so for the five
-<
+     * sprawling variants of put-related operations).
->
+     * variants of put-related operations). The validation-based
->
+     * approach explained below leads to a lot of code sprawl because
->
+     * retry-control precludes factoring into smaller methods.
+     * The table is lazily initialized to a power-of-two size upon the
-<
+     * first insertion.  Each bin in the table contains a list of
-<
+     * Nodes (most often, the list has only zero or one Node).  Table
-<
+     * accesses require volatile/atomic reads, writes, and CASes.
-<
+     * Because there is no other way to arrange this without adding
-<
+     * further indirections, we use intrinsics (sun.misc.Unsafe)
-<
+     * operations.  The lists of nodes within bins are always
-<
+     * accurately traversable under volatile reads, so long as lookups
-<
+     * check hash code and non-nullness of value before checking key
-<
+     * equality.
->
+     * first insertion.  Each bin in the table normally contains a
->
+     * list of Nodes (most often, the list has only zero or one Node).
->
+     * Table accesses require volatile/atomic reads, writes, and
->
+     * CASes.  Because there is no other way to arrange this without
->
+     * adding further indirections, we use intrinsics
->
+     * (sun.misc.Unsafe) operations.  The lists of nodes within bins
->
+     * are always accurately traversable under volatile reads, so long
->
+     * as lookups check hash code and non-nullness of value before
->
+     * checking key equality.
+     * We use the top two bits of Node hash fields for control
+     * purposes -- they are available anyway because of addressing
+     *  10 - Node is a forwarding node
+     * The lower 30 bits of each Node's hash field contain a
-<
+     * transformation (for better randomization -- method "spread") of
-<
+     * the key's hash code, except for forwarding nodes, for which the
-<
+     * lower bits are zero (and so always have hash field == MOVED).
->
+     * transformation of the key's hash code, except for forwarding
->
+     * nodes, for which the lower bits are zero (and so always have
->
+     * hash field == MOVED).
+     * Insertion (via put or its variants) of the first node in an
+     * empty bin is performed by just CASing it to the bin.  This is
-<
+     * by far the most common case for put operations.  Other update
-<
+     * operations (insert, delete, and replace) require locks.  We do
-<
+     * not want to waste the space required to associate a distinct
-<
+     * lock object with each bin, so instead use the first node of a
-<
+     * bin list itself as a lock. Blocking support for these locks
-<
+     * relies on the builtin "synchronized" monitors.  However, we
-<
+     * also need a tryLock construction, so we overlay these by using
-<
+     * bits of the Node hash field for lock control (see above), and
-<
+     * so normally use builtin monitors only for blocking and
-<
+     * signalling using wait/notifyAll constructions. See
-<
+     * Node.tryAwaitLock.
->
+     * by far the most common case for put operations under most
->
+     * key/hash distributions.  Other update operations (insert,
->
+     * delete, and replace) require locks.  We do not want to waste
->
+     * the space required to associate a distinct lock object with
->
+     * each bin, so instead use the first node of a bin list itself as
->
+     * a lock. Blocking support for these locks relies on the builtin
->
+     * "synchronized" monitors.  However, we also need a tryLock
->
+     * construction, so we overlay these by using bits of the Node
->
+     * hash field for lock control (see above), and so normally use
->
+     * builtin monitors only for blocking and signalling using
->
+     * wait/notifyAll constructions. See Node.tryAwaitLock.
+     * Using the first node of a list as a lock does not by itself
+     * suffice though: When a node is locked, any update must first
+     * The main disadvantage of per-bin locks is that other update
+     * operations on other nodes in a bin list protected by the same
+     * lock can stall, for example when user equals() or mapping
-<
+     * functions take a long time.  However, statistically, this is
-<
+     * not a common enough problem to outweigh the time/space overhead
-<
+     * of alternatives: Under random hash codes, the frequency of
-<
+     * nodes in bins follows a Poisson distribution
->
+     * functions take a long time.  However, statistically, under
->
+     * random hash codes, this is not a common problem.  Ideally, the
->
+     * frequency of nodes in bins follows a Poisson distribution
+     * (http://en.wikipedia.org/wiki/Poisson_distribution) with a
+     * parameter of about 0.5 on average, given the resizing threshold
+     * of 0.75, although with a large variance because of resizing
+     * granularity. Ignoring variance, the expected occurrences of
+     * list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
-<
+     * first few values are:
->
+     * first values are:
-<
+     * 0:    0.607
-<
+     * 1:    0.303
-<
+     * 2:    0.076
-<
+     * 3:    0.012
-<
+     * more: 0.002
->
+     * 0:    0.60653066
->
+     * 1:    0.30326533
->
+     * 2:    0.07581633
->
+     * 3:    0.01263606
->
+     * 4:    0.00157952
->
+     * 5:    0.00015795
->
+     * 6:    0.00001316
->
+     * 7:    0.00000094
->
+     * 8:    0.00000006
->
+     * more: less than 1 in ten million
+     * Lock contention probability for two threads accessing distinct
-<
+     * elements is roughly 1 / (8 * #elements).  Function "spread"
-<
+     * performs hashCode randomization that improves the likelihood
-<
+     * that these assumptions hold unless users define exactly the
-<
+     * same value for too many hashCodes.
->
+     * elements is roughly 1 / (8 * #elements) under random hashes.
->
+     *
->
+     * Actual hash code distributions encountered in practice
->
+     * sometimes deviate significantly from uniform randomness.  This
->
+     * includes the case when N > (1<<30), so some keys MUST collide.
->
+     * Similarly for dumb or hostile usages in which multiple keys are
->
+     * designed to have identical hash codes. Also, although we guard
->
+     * against the worst effects of this (see method spread), sets of
->
+     * hashes may differ only in bits that do not impact their bin
->
+     * index for a given power-of-two mask.  So we use a secondary
->
+     * strategy that applies when the number of nodes in a bin exceeds
->
+     * a threshold, and at least one of the keys implements
->
+     * Comparable.  These TreeBins use a balanced tree to hold nodes
->
+     * (a specialized form of red-black trees), bounding search time
->
+     * to O(log N).  Each search step in a TreeBin is around twice as
->
+     * slow as in a regular list, but given that N cannot exceed
->
+     * (1<<64) (before running out of addresses) this bounds search
->
+     * steps, lock hold times, etc, to reasonable constants (roughly
->
+     * 100 nodes inspected per operation worst case) so long as keys
->
+     * are Comparable (which is very common -- String, Long, etc).
->
+     * TreeBin nodes (TreeNodes) also maintain the same "next"
->
+     * traversal pointers as regular nodes, so can be traversed in
->
+     * iterators in the same way.
-<
+     * The table is resized when occupancy exceeds an occupancy
->
+     * The table is resized when occupancy exceeds a percentage
+     * threshold (nominally, 0.75, but see below).  Only a single
+     * thread performs the resize (using field "sizeCtl", to arrange
+     * exclusion), but the table otherwise remains usable for reads
+     * Each bin transfer requires its bin lock. However, unlike other
+     * cases, a transfer can skip a bin if it fails to acquire its
-<
+     * lock, and revisit it later. Method rebuild maintains a buffer
-<
+     * of TRANSFER_BUFFER_SIZE bins that have been skipped because of
-<
+     * failure to acquire a lock, and blocks only if none are
-<
+     * available (i.e., only very rarely).  The transfer operation
-<
+     * must also ensure that all accessible bins in both the old and
-<
+     * new table are usable by any traversal.  When there are no lock
-<
+     * acquisition failures, this is arranged simply by proceeding
-<
+     * from the last bin (table.length - 1) up towards the first.
-<
+     * Upon seeing a forwarding node, traversals (see class
-<
+     * InternalIterator) arrange to move to the new table without
-<
+     * revisiting nodes.  However, when any node is skipped during a
-<
+     * transfer, all earlier table bins may have become visible, so
-<
+     * are initialized with a reverse-forwarding node back to the old
-<
+     * table until the new ones are established. (This sometimes
-<
+     * requires transiently locking a forwarding node, which is
-<
+     * possible under the above encoding.) These more expensive
->
+     * lock, and revisit it later (unless it is a TreeBin). Method
->
+     * rebuild maintains a buffer of TRANSFER_BUFFER_SIZE bins that
->
+     * have been skipped because of failure to acquire a lock, and
->
+     * blocks only if none are available (i.e., only very rarely).
->
+     * The transfer operation must also ensure that all accessible
->
+     * bins in both the old and new table are usable by any traversal.
->
+     * When there are no lock acquisition failures, this is arranged
->
+     * simply by proceeding from the last bin (table.length - 1) up
->
+     * towards the first.  Upon seeing a forwarding node, traversals
->
+     * (see class Iter) arrange to move to the new table
->
+     * without revisiting nodes.  However, when any node is skipped
->
+     * during a transfer, all earlier table bins may have become
->
+     * visible, so are initialized with a reverse-forwarding node back
->
+     * to the old table until the new ones are established. (This
->
+     * sometimes requires transiently locking a forwarding node, which
->
+     * is possible under the above encoding.) These more expensive
+     * mechanics trigger only when necessary.
+     * The traversal scheme also applies to partial traversals of
-<
+     * ranges of bins (via an alternate InternalIterator constructor)
-<
+     * to support partitioned aggregate operations (that are not
-<
+     * otherwise implemented yet).  Also, read-only operations give up
-<
+     * if ever forwarded to a null table, which provides support for
-<
+     * shutdown-style clearing, which is also not currently
-<
+     * implemented.
->
+     * ranges of bins (via an alternate Traverser constructor)
->
+     * to support partitioned aggregate operations.  Also, read-only
->
+     * operations give up if ever forwarded to a null table, which
->
+     * provides support for shutdown-style clearing, which is also not
->
+     * currently implemented.
+     * Lazy table initialization minimizes footprint until first use,
+     * and also avoids resizings when the first operation is from a
+     */
+    private static final int TRANSFER_BUFFER_SIZE = 32;
-+
+    /**
-+
+     * The bin count threshold for using a tree rather than list for a
-+
+     * bin.  The value reflects the approximate break-even point for
-+
+     * using tree-based operations.
-+
+     */
-+
+    private static final int TREE_THRESHOLD = 8;
-+
+    /*
+     * Encodings for special uses of Node hash fields. See above for
+     * explanation.
+     */
-<
+    static final int MOVED     = 0x80000000; // hash field for fowarding nodes
->
+    static final int MOVED     = 0x80000000; // hash field for forwarding nodes
+    static final int LOCKED    = 0x40000000; // set/tested only as a bit
+    static final int WAITING   = 0xc0000000; // both bits set/tested together
+    static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash
+    private transient volatile int sizeCtl;
+    // views
-<
+    private transient KeySet<K,V> keySet;
-<
+    private transient Values<K,V> values;
-<
+    private transient EntrySet<K,V> entrySet;
->
+    private transient KeySetView<K,V> keySet;
->
+    private transient ValuesView<K,V> values;
->
+    private transient EntrySetView<K,V> entrySet;
+    /** For serialization compatibility. Null unless serialized; see below */
+    private Segment<K,V>[] segments;
-+
+    /* ---------------- Table element access -------------- */
-+
-+
+    /*
-+
+     * Volatile access methods are used for table elements as well as
-+
+     * elements of in-progress next table while resizing.  Uses are
-+
+     * null checked by callers, and implicitly bounds-checked, relying
-+
+     * on the invariants that tab arrays have non-zero size, and all
-+
+     * indices are masked with (tab.length - 1) which is never
-+
+     * negative and always less than length. Note that, to be correct
-+
+     * wrt arbitrary concurrency errors by users, bounds checks must
-+
+     * operate on local variables, which accounts for some odd-looking
-+
+     * inline assignments below.
-+
+     */
-+
-+
+    static final Node tabAt(Node[] tab, int i) { // used by Iter
-+
+        return (Node)UNSAFE.getObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE);
-+
+    }
-+
-+
+    private static final boolean casTabAt(Node[] tab, int i, Node c, Node v) {
-+
+        return UNSAFE.compareAndSwapObject(tab, ((long)i<<ASHIFT)+ABASE, c, v);
-+
+    }
-+
-+
+    private static final void setTabAt(Node[] tab, int i, Node v) {
-+
+        UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v);
-+
+    }
-+
+    /* ---------------- Nodes -------------- */
+    /**
+     * Key-value entry. Note that this is never exported out as a
-<
+     * user-visible Map.Entry (see WriteThroughEntry and SnapshotEntry
-<
+     * below). Nodes with a hash field of MOVED are special, and do
-<
+     * not contain user keys or values.  Otherwise, keys are never
-<
+     * null, and null val fields indicate that a node is in the
-<
+     * process of being deleted or created. For purposes of read-only
-<
+     * access, a key may be read before a val, but can only be used
-<
+     * after checking val to be non-null.
->
+     * user-visible Map.Entry (see MapEntry below). Nodes with a hash
->
+     * field of MOVED are special, and do not contain user keys or
->
+     * values.  Otherwise, keys are never null, and null val fields
->
+     * indicate that a node is in the process of being deleted or
->
+     * created. For purposes of read-only access, a key may be read
->
+     * before a val, but can only be used after checking val to be
->
+     * non-null.
+     */
-<
+    static final class Node {
->
+    static class Node {
+        volatile int hash;
+        final Object key;
+        volatile Object val;
+         * unlocking lock (via a failed CAS from non-waiting LOCKED
+         * state), unlockers acquire the sync lock and perform a
+         * notifyAll.
-+
+         *
-+
+         * The initial sanity check on tab and bounds is not currently
-+
+         * necessary in the only usages of this method, but enables
-+
+         * use in other future contexts.
+         */
+        final void tryAwaitLock(Node[] tab, int i) {
-<
+            if (tab != null && i >= 0 && i < tab.length) { // bounds check
->
+            if (tab != null && i >= 0 && i < tab.length) { // sanity check
->
+                int r = ThreadLocalRandom.current().nextInt(); // randomize spins
+                int spins = MAX_SPINS, h;
+                while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) {
+                    if (spins >= 0) {
-<
+                        if (--spins == MAX_SPINS >>> 1)
-<
+                            Thread.yield();  // heuristically yield mid-way
->
+                        r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
->
+                        if (r >= 0 && --spins == 0)
->
+                            Thread.yield();  // yield before block
+                    else if (casHash(h, h | WAITING)) {
+                        synchronized (this) {
+                                try {
+                                    wait();
+                                } catch (InterruptedException ie) {
-<
+                                    Thread.currentThread().interrupt();
->
+                                    try {
->
+                                        Thread.currentThread().interrupt();
->
+                                    } catch (SecurityException ignore) {
->
+                                    }
+                            else
-<
+    /* ---------------- Table element access -------------- */
->
+    /* ---------------- TreeBins -------------- */
-<
+    /*
-<
+     * Volatile access methods are used for table elements as well as
-<
+     * elements of in-progress next table while resizing.  Uses are
-<
+     * null checked by callers, and implicitly bounds-checked, relying
-<
+     * on the invariants that tab arrays have non-zero size, and all
-<
+     * indices are masked with (tab.length - 1) which is never
-<
+     * negative and always less than length. Note that, to be correct
-<
+     * wrt arbitrary concurrency errors by users, bounds checks must
-<
+     * operate on local variables, which accounts for some odd-looking
-<
+     * inline assignments below.
->
+    /**
->
+     * Nodes for use in TreeBins
+     */
-<
-<
+    static final Node tabAt(Node[] tab, int i) { // used by InternalIterator
-<
+        return (Node)UNSAFE.getObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE);
->
+    static final class TreeNode extends Node {
->
+        TreeNode parent;  // red-black tree links
->
+        TreeNode left;
->
+        TreeNode right;
->
+        TreeNode prev;    // needed to unlink next upon deletion
->
+        boolean red;
->
->
+        TreeNode(int hash, Object key, Object val, Node next, TreeNode parent) {
->
+            super(hash, key, val, next);
->
+            this.parent = parent;
->
+        }
-<
+    private static final boolean casTabAt(Node[] tab, int i, Node c, Node v) {
-<
+        return UNSAFE.compareAndSwapObject(tab, ((long)i<<ASHIFT)+ABASE, c, v);
-<
+    }
->
+    /**
->
+     * A specialized form of red-black tree for use in bins
->
+     * whose size exceeds a threshold.
->
+     *
->
+     * TreeBins use a special form of comparison for search and
->
+     * related operations (which is the main reason we cannot use
->
+     * existing collections such as TreeMaps). TreeBins contain
->
+     * Comparable elements, but may contain others, as well as
->
+     * elements that are Comparable but not necessarily Comparable<T>
->
+     * for the same T, so we cannot invoke compareTo among them. To
->
+     * handle this, the tree is ordered primarily by hash value, then
->
+     * by getClass().getName() order, and then by Comparator order
->
+     * among elements of the same class.  On lookup at a node, if
->
+     * elements are not comparable or compare as 0, both left and
->
+     * right children may need to be searched in the case of tied hash
->
+     * values. (This corresponds to the full list search that would be
->
+     * necessary if all elements were non-Comparable and had tied
->
+     * hashes.)  The red-black balancing code is updated from
->
+     * pre-jdk-collections
->
+     * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
->
+     * based in turn on Cormen, Leiserson, and Rivest "Introduction to
->
+     * Algorithms" (CLR).
->
+     *
->
+     * TreeBins also maintain a separate locking discipline than
->
+     * regular bins. Because they are forwarded via special MOVED
->
+     * nodes at bin heads (which can never change once established),
->
+     * we cannot use those nodes as locks. Instead, TreeBin
->
+     * extends AbstractQueuedSynchronizer to support a simple form of
->
+     * read-write lock. For update operations and table validation,
->
+     * the exclusive form of lock behaves in the same way as bin-head
->
+     * locks. However, lookups use shared read-lock mechanics to allow
->
+     * multiple readers in the absence of writers.  Additionally,
->
+     * these lookups do not ever block: While the lock is not
->
+     * available, they proceed along the slow traversal path (via
->
+     * next-pointers) until the lock becomes available or the list is
->
+     * exhausted, whichever comes first. (These cases are not fast,
->
+     * but maximize aggregate expected throughput.)  The AQS mechanics
->
+     * for doing this are straightforward.  The lock state is held as
->
+     * AQS getState().  Read counts are negative; the write count (1)
->
+     * is positive.  There are no signalling preferences among readers
->
+     * and writers. Since we don't need to export full Lock API, we
->
+     * just override the minimal AQS methods and use them directly.
->
+     */
->
+    static final class TreeBin extends AbstractQueuedSynchronizer {
->
+        private static final long serialVersionUID = 2249069246763182397L;
->
+        transient TreeNode root;  // root of tree
->
+        transient TreeNode first; // head of next-pointer list
-<
+    private static final void setTabAt(Node[] tab, int i, Node v) {
-<
+        UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v);
-<
+    }
->
+        /* AQS overrides */
->
+        public final boolean isHeldExclusively() { return getState() > 0; }
->
+        public final boolean tryAcquire(int ignore) {
->
+            if (compareAndSetState(0, 1)) {
->
+                setExclusiveOwnerThread(Thread.currentThread());
->
+                return true;
->
+            }
->
+            return false;
->
+        }
->
+        public final boolean tryRelease(int ignore) {
->
+            setExclusiveOwnerThread(null);
->
+            setState(0);
->
+            return true;
->
+        }
->
+        public final int tryAcquireShared(int ignore) {
->
+            for (int c;;) {
->
+                if ((c = getState()) > 0)
->
+                    return -1;
->
+                if (compareAndSetState(c, c -1))
->
+                    return 1;
->
+            }
->
+        }
->
+        public final boolean tryReleaseShared(int ignore) {
->
+            int c;
->
+            do {} while (!compareAndSetState(c = getState(), c + 1));
->
+            return c == -1;
->
+        }
->
->
+        /** From CLR */
->
+        private void rotateLeft(TreeNode p) {
->
+            if (p != null) {
->
+                TreeNode r = p.right, pp, rl;
->
+                if ((rl = p.right = r.left) != null)
->
+                    rl.parent = p;
->
+                if ((pp = r.parent = p.parent) == null)
->
+                    root = r;
->
+                else if (pp.left == p)
->
+                    pp.left = r;
->
+                else
->
+                    pp.right = r;
->
+                r.left = p;
->
+                p.parent = r;
->
+            }
->
+        }
-<
+    /* ---------------- Internal access and update methods -------------- */
->
+        /** From CLR */
->
+        private void rotateRight(TreeNode p) {
->
+            if (p != null) {
->
+                TreeNode l = p.left, pp, lr;
->
+                if ((lr = p.left = l.right) != null)
->
+                    lr.parent = p;
->
+                if ((pp = l.parent = p.parent) == null)
->
+                    root = l;
->
+                else if (pp.right == p)
->
+                    pp.right = l;
->
+                else
->
+                    pp.left = l;
->
+                l.right = p;
->
+                p.parent = l;
->
+            }
->
+        }
-<
+    /**
-<
+     * Applies a supplemental hash function to a given hashCode, which
-<
+     * defends against poor quality hash functions.  The result must
-<
+     * be have the top 2 bits clear. For reasonable performance, this
-<
+     * function must have good avalanche properties; i.e., that each
-<
+     * bit of the argument affects each bit of the result. (Although
-<
+     * we don't care about the unused top 2 bits.)
->
+        /**
->
+         * Returns the TreeNode (or null if not found) for the given key
->
+         * starting at given root.
->
+         */
->
+        @SuppressWarnings("unchecked") final TreeNode getTreeNode
->
+            (int h, Object k, TreeNode p) {
->
+            Class<?> c = k.getClass();
->
+            while (p != null) {
->
+                int dir, ph;  Object pk; Class<?> pc;
->
+                if ((ph = p.hash) == h) {
->
+                    if ((pk = p.key) == k || k.equals(pk))
->
+                        return p;
->
+                    if (c != (pc = pk.getClass()) ||
->
+                        !(k instanceof Comparable) ||
->
+                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
->
+                        if ((dir = (c == pc) ? 0 :
->
+                             c.getName().compareTo(pc.getName())) == 0) {
->
+                            TreeNode r = null, pl, pr; // check both sides
->
+                            if ((pr = p.right) != null && h >= pr.hash &&
->
+                                (r = getTreeNode(h, k, pr)) != null)
->
+                                return r;
->
+                            else if ((pl = p.left) != null && h <= pl.hash)
->
+                                dir = -1;
->
+                            else // nothing there
->
+                                return null;
->
+                        }
->
+                    }
->
+                }
->
+                else
->
+                    dir = (h < ph) ? -1 : 1;
->
+                p = (dir > 0) ? p.right : p.left;
->
+            }
->
+            return null;
->
+        }
->
->
+        /**
->
+         * Wrapper for getTreeNode used by CHM.get. Tries to obtain
->
+         * read-lock to call getTreeNode, but during failure to get
->
+         * lock, searches along next links.
->
+         */
->
+        final Object getValue(int h, Object k) {
->
+            Node r = null;
->
+            int c = getState(); // Must read lock state first
->
+            for (Node e = first; e != null; e = e.next) {
->
+                if (c <= 0 && compareAndSetState(c, c - 1)) {
->
+                    try {
->
+                        r = getTreeNode(h, k, root);
->
+                    } finally {
->
+                        releaseShared(0);
->
+                    }
->
+                    break;
->
+                }
->
+                else if ((e.hash & HASH_BITS) == h && k.equals(e.key)) {
->
+                    r = e;
->
+                    break;
->
+                }
->
+                else
->
+                    c = getState();
->
+            }
->
+            return r == null ? null : r.val;
->
+        }
->
->
+        /**
->
+         * Finds or adds a node.
->
+         * @return null if added
->
+         */
->
+        @SuppressWarnings("unchecked") final TreeNode putTreeNode
->
+            (int h, Object k, Object v) {
->
+            Class<?> c = k.getClass();
->
+            TreeNode pp = root, p = null;
->
+            int dir = 0;
->
+            while (pp != null) { // find existing node or leaf to insert at
->
+                int ph;  Object pk; Class<?> pc;
->
+                p = pp;
->
+                if ((ph = p.hash) == h) {
->
+                    if ((pk = p.key) == k || k.equals(pk))
->
+                        return p;
->
+                    if (c != (pc = pk.getClass()) ||
->
+                        !(k instanceof Comparable) ||
->
+                        (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
->
+                        TreeNode s = null, r = null, pr;
->
+                        if ((dir = (c == pc) ? 0 :
->
+                             c.getName().compareTo(pc.getName())) == 0) {
->
+                            if ((pr = p.right) != null && h >= pr.hash &&
->
+                                (r = getTreeNode(h, k, pr)) != null)
->
+                                return r;
->
+                            else // continue left
->
+                                dir = -1;
->
+                        }
->
+                        else if ((pr = p.right) != null && h >= pr.hash)
->
+                            s = pr;
->
+                        if (s != null && (r = getTreeNode(h, k, s)) != null)
->
+                            return r;
->
+                    }
->
+                }
->
+                else
->
+                    dir = (h < ph) ? -1 : 1;
->
+                pp = (dir > 0) ? p.right : p.left;
->
+            }
->
->
+            TreeNode f = first;
->
+            TreeNode x = first = new TreeNode(h, k, v, f, p);
->
+            if (p == null)
->
+                root = x;
->
+            else { // attach and rebalance; adapted from CLR
->
+                TreeNode xp, xpp;
->
+                if (f != null)
->
+                    f.prev = x;
->
+                if (dir <= 0)
->
+                    p.left = x;
->
+                else
->
+                    p.right = x;
->
+                x.red = true;
->
+                while (x != null && (xp = x.parent) != null && xp.red &&
->
+                       (xpp = xp.parent) != null) {
->
+                    TreeNode xppl = xpp.left;
->
+                    if (xp == xppl) {
->
+                        TreeNode y = xpp.right;
->
+                        if (y != null && y.red) {
->
+                            y.red = false;
->
+                            xp.red = false;
->
+                            xpp.red = true;
->
+                            x = xpp;
->
+                        }
->
+                        else {
->
+                            if (x == xp.right) {
->
+                                rotateLeft(x = xp);
->
+                                xpp = (xp = x.parent) == null ? null : xp.parent;
->
+                            }
->
+                            if (xp != null) {
->
+                                xp.red = false;
->
+                                if (xpp != null) {
->
+                                    xpp.red = true;
->
+                                    rotateRight(xpp);
->
+                                }
->
+                            }
->
+                        }
->
+                    }
->
+                    else {
->
+                        TreeNode y = xppl;
->
+                        if (y != null && y.red) {
->
+                            y.red = false;
->
+                            xp.red = false;
->
+                            xpp.red = true;
->
+                            x = xpp;
->
+                        }
->
+                        else {
->
+                            if (x == xp.left) {
->
+                                rotateRight(x = xp);
->
+                                xpp = (xp = x.parent) == null ? null : xp.parent;
->
+                            }
->
+                            if (xp != null) {
->
+                                xp.red = false;
->
+                                if (xpp != null) {
->
+                                    xpp.red = true;
->
+                                    rotateLeft(xpp);
->
+                                }
->
+                            }
->
+                        }
->
+                    }
->
+                }
->
+                TreeNode r = root;
->
+                if (r != null && r.red)
->
+                    r.red = false;
->
+            }
->
+            return null;
->
+        }
->
->
+        /**
->
+         * Removes the given node, that must be present before this
->
+         * call.  This is messier than typical red-black deletion code
->
+         * because we cannot swap the contents of an interior node
->
+         * with a leaf successor that is pinned by "next" pointers
->
+         * that are accessible independently of lock. So instead we
->
+         * swap the tree linkages.
->
+         */
->
+        final void deleteTreeNode(TreeNode p) {
->
+            TreeNode next = (TreeNode)p.next; // unlink traversal pointers
->
+            TreeNode pred = p.prev;
->
+            if (pred == null)
->
+                first = next;
->
+            else
->
+                pred.next = next;
->
+            if (next != null)
->
+                next.prev = pred;
->
+            TreeNode replacement;
->
+            TreeNode pl = p.left;
->
+            TreeNode pr = p.right;
->
+            if (pl != null && pr != null) {
->
+                TreeNode s = pr, sl;
->
+                while ((sl = s.left) != null) // find successor
->
+                    s = sl;
->
+                boolean c = s.red; s.red = p.red; p.red = c; // swap colors
->
+                TreeNode sr = s.right;
->
+                TreeNode pp = p.parent;
->
+                if (s == pr) { // p was s's direct parent
->
+                    p.parent = s;
->
+                    s.right = p;
->
+                }
->
+                else {
->
+                    TreeNode sp = s.parent;
->
+                    if ((p.parent = sp) != null) {
->
+                        if (s == sp.left)
->
+                            sp.left = p;
->
+                        else
->
+                            sp.right = p;
->
+                    }
->
+                    if ((s.right = pr) != null)
->
+                        pr.parent = s;
->
+                }
->
+                p.left = null;
->
+                if ((p.right = sr) != null)
->
+                    sr.parent = p;
->
+                if ((s.left = pl) != null)
->
+                    pl.parent = s;
->
+                if ((s.parent = pp) == null)
->
+                    root = s;
->
+                else if (p == pp.left)
->
+                    pp.left = s;
->
+                else
->
+                    pp.right = s;
->
+                replacement = sr;
->
+            }
->
+            else
->
+                replacement = (pl != null) ? pl : pr;
->
+            TreeNode pp = p.parent;
->
+            if (replacement == null) {
->
+                if (pp == null) {
->
+                    root = null;
->
+                    return;
->
+                }
->
+                replacement = p;
->
+            }
->
+            else {
->
+                replacement.parent = pp;
->
+                if (pp == null)
->
+                    root = replacement;
->
+                else if (p == pp.left)
->
+                    pp.left = replacement;
->
+                else
->
+                    pp.right = replacement;
->
+                p.left = p.right = p.parent = null;
->
+            }
->
+            if (!p.red) { // rebalance, from CLR
->
+                TreeNode x = replacement;
->
+                while (x != null) {
->
+                    TreeNode xp, xpl;
->
+                    if (x.red || (xp = x.parent) == null) {
->
+                        x.red = false;
->
+                        break;
->
+                    }
->
+                    if (x == (xpl = xp.left)) {
->
+                        TreeNode sib = xp.right;
->
+                        if (sib != null && sib.red) {
->
+                            sib.red = false;
->
+                            xp.red = true;
->
+                            rotateLeft(xp);
->
+                            sib = (xp = x.parent) == null ? null : xp.right;
->
+                        }
->
+                        if (sib == null)
->
+                            x = xp;
->
+                        else {
->
+                            TreeNode sl = sib.left, sr = sib.right;
->
+                            if ((sr == null || !sr.red) &&
->
+                                (sl == null || !sl.red)) {
->
+                                sib.red = true;
->
+                                x = xp;
->
+                            }
->
+                            else {
->
+                                if (sr == null || !sr.red) {
->
+                                    if (sl != null)
->
+                                        sl.red = false;
->
+                                    sib.red = true;
->
+                                    rotateRight(sib);
->
+                                    sib = (xp = x.parent) == null ? null : xp.right;
->
+                                }
->
+                                if (sib != null) {
->
+                                    sib.red = (xp == null) ? false : xp.red;
->
+                                    if ((sr = sib.right) != null)
->
+                                        sr.red = false;
->
+                                }
->
+                                if (xp != null) {
->
+                                    xp.red = false;
->
+                                    rotateLeft(xp);
->
+                                }
->
+                                x = root;
->
+                            }
->
+                        }
->
+                    }
->
+                    else { // symmetric
->
+                        TreeNode sib = xpl;
->
+                        if (sib != null && sib.red) {
->
+                            sib.red = false;
->
+                            xp.red = true;
->
+                            rotateRight(xp);
->
+                            sib = (xp = x.parent) == null ? null : xp.left;
->
+                        }
->
+                        if (sib == null)
->
+                            x = xp;
->
+                        else {
->
+                            TreeNode sl = sib.left, sr = sib.right;
->
+                            if ((sl == null || !sl.red) &&
->
+                                (sr == null || !sr.red)) {
->
+                                sib.red = true;
->
+                                x = xp;
->
+                            }
->
+                            else {
->
+                                if (sl == null || !sl.red) {
->
+                                    if (sr != null)
->
+                                        sr.red = false;
->
+                                    sib.red = true;
->
+                                    rotateLeft(sib);
->
+                                    sib = (xp = x.parent) == null ? null : xp.left;
->
+                                }
->
+                                if (sib != null) {
->
+                                    sib.red = (xp == null) ? false : xp.red;
->
+                                    if ((sl = sib.left) != null)
->
+                                        sl.red = false;
->
+                                }
->
+                                if (xp != null) {
->
+                                    xp.red = false;
->
+                                    rotateRight(xp);
->
+                                }
->
+                                x = root;
->
+                            }
->
+                        }
->
+                    }
->
+                }
->
+            }
->
+            if (p == replacement && (pp = p.parent) != null) {
->
+                if (p == pp.left) // detach pointers
->
+                    pp.left = null;
->
+                else if (p == pp.right)
->
+                    pp.right = null;
->
+                p.parent = null;
->
+            }
->
+        }
->
+    }
->
->
+    /* ---------------- Collision reduction methods -------------- */
->
->
+    /**
->
+     * Spreads higher bits to lower, and also forces top 2 bits to 0.
->
+     * Because the table uses power-of-two masking, sets of hashes
->
+     * that vary only in bits above the current mask will always
->
+     * collide. (Among known examples are sets of Float keys holding
->
+     * consecutive whole numbers in small tables.)  To counter this,
->
+     * we apply a transform that spreads the impact of higher bits
->
+     * downward. There is a tradeoff between speed, utility, and
->
+     * quality of bit-spreading. Because many common sets of hashes
->
+     * are already reasonably distributed across bits (so don't benefit
->
+     * from spreading), and because we use trees to handle large sets
->
+     * of collisions in bins, we don't need excessively high quality.
+     */
+    private static final int spread(int h) {
-<
+        // Apply base step of MurmurHash; see http://code.google.com/p/smhasher/
-<
+        // Despite two multiplies, this is often faster than others
-<
+        // with comparable bit-spread properties.
-<
+        h ^= h >>> 16;
-<
+        h *= 0x85ebca6b;
-<
+        h ^= h >>> 13;
-<
+        h *= 0xc2b2ae35;
-<
+        return ((h >>> 16) ^ h) & HASH_BITS; // mask out top bits
->
+        h ^= (h >>> 18) ^ (h >>> 12);
->
+        return (h ^ (h >>> 10)) & HASH_BITS;
->
+    }
->
->
+    /**
->
+     * Replaces a list bin with a tree bin. Call only when locked.
->
+     * Fails to replace if the given key is non-comparable or table
->
+     * is, or needs, resizing.
->
+     */
->
+    private final void replaceWithTreeBin(Node[] tab, int index, Object key) {
->
+        if ((key instanceof Comparable) &&
->
+            (tab.length >= MAXIMUM_CAPACITY || counter.sum() < (long)sizeCtl)) {
->
+            TreeBin t = new TreeBin();
->
+            for (Node e = tabAt(tab, index); e != null; e = e.next)
->
+                t.putTreeNode(e.hash & HASH_BITS, e.key, e.val);
->
+            setTabAt(tab, index, new Node(MOVED, t, null, null));
->
+        }
-+
+    /* ---------------- Internal access and update methods -------------- */
-+
+    /** Implementation for get and containsKey */
+    private final Object internalGet(Object k) {
+        int h = spread(k.hashCode());
+        retry: for (Node[] tab = table; tab != null;) {
-<
+            Node e; Object ek, ev; int eh;    // locals to read fields once
->
+            Node e, p; Object ek, ev; int eh;      // locals to read fields once
+            for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
+                if ((eh = e.hash) == MOVED) {
-<
+                    tab = (Node[])e.key;      // restart with new table
-<
+                    continue retry;
->
+                    if ((ek = e.key) instanceof TreeBin)  // search TreeBin
->
+                        return ((TreeBin)ek).getValue(h, k);
->
+                    else {                        // restart with new table
->
+                        tab = (Node[])ek;
->
+                        continue retry;
->
+                    }
-<
+                if ((eh & HASH_BITS) == h && (ev = e.val) != null &&
-<
+                    ((ek = e.key) == k || k.equals(ek)))
->
+                else if ((eh & HASH_BITS) == h && (ev = e.val) != null &&
->
+                         ((ek = e.key) == k || k.equals(ek)))
+                    return ev;
+            break;
+        int h = spread(k.hashCode());
+        Object oldVal = null;
+        for (Node[] tab = table;;) {
-<
+            Node f; int i, fh;
->
+            Node f; int i, fh; Object fk;
+            if (tab == null ||
+                (f = tabAt(tab, i = (tab.length - 1) & h)) == null)
+                break;
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    boolean validated = false;
->
+                    boolean deleted = false;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            validated = true;
->
+                            TreeNode p = t.getTreeNode(h, k, t.root);
->
+                            if (p != null) {
->
+                                Object pv = p.val;
->
+                                if (cv == null || cv == pv || cv.equals(pv)) {
->
+                                    oldVal = pv;
->
+                                    if ((p.val = v) == null) {
->
+                                        deleted = true;
->
+                                        t.deleteTreeNode(p);
->
+                                    }
->
+                                }
->
+                            }
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (validated) {
->
+                        if (deleted)
->
+                            counter.add(-1L);
->
+                        break;
->
+                    }
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & HASH_BITS) != h && f.next == null) // precheck
+                break;                          // rules out possible existence
+            else if ((fh & LOCKED) != 0) {
+    /*
-<
+     * Internal versions of the five insertion methods, each a
->
+     * Internal versions of the six insertion methods, each a
+     * little more complicated than the last. All have
+     * the same basic structure as the first (internalPut):
+     *  1. If table uninitialized, create
+     *  2. If bin empty, try to CAS new node
+     *  3. If bin stale, use new table
-<
+     *  4. Lock and validate; if valid, scan and add or update
->
+     *  4. if bin converted to TreeBin, validate and relay to TreeBin methods
->
+     *  5. Lock and validate; if valid, scan and add or update
+     * The others interweave other checks and/or alternative actions:
+     *  * Plain put checks for and performs resize after insertion.
+     *    returns from function call.
+     *  * compute uses the same function-call mechanics, but without
+     *    the prescans
-+
+     *  * merge acts as putIfAbsent in the absent case, but invokes the
-+
+     *    update function if present
+     *  * putAll attempts to pre-allocate enough table space
+     *    and more lazily performs count updates and checks.
+    /** Implementation for put */
+    private final Object internalPut(Object k, Object v) {
+        int h = spread(k.hashCode());
-<
+        boolean checkSize = false;
->
+        int count = 0;
+        for (Node[] tab = table;;) {
-<
+            int i; Node f; int fh;
->
+            int i; Node f; int fh; Object fk;
+            if (tab == null)
+                tab = initTable();
+            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
+                if (casTabAt(tab, i, null, new Node(h, k, v, null)))
+                    break;                   // no lock when adding to empty bin
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    Object oldVal = null;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            count = 2;
->
+                            TreeNode p = t.putTreeNode(h, k, v);
->
+                            if (p != null) {
->
+                                oldVal = p.val;
->
+                                p.val = v;
->
+                            }
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (count != 0) {
->
+                        if (oldVal != null)
->
+                            return oldVal;
->
+                        break;
->
+                    }
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & LOCKED) != 0) {
+                checkForResize();
+                f.tryAwaitLock(tab, i);
+            else if (f.casHash(fh, fh | LOCKED)) {
+                Object oldVal = null;
-–
+                boolean validated = false;
+                try {                        // needed in case equals() throws
+                    if (tabAt(tab, i) == f) {
-<
+                        validated = true;    // retry if 1st already deleted
-<
+                        for (Node e = f;;) {
->
+                        count = 1;
->
+                        for (Node e = f;; ++count) {
+                            Object ek, ev;
+                            if ((e.hash & HASH_BITS) == h &&
+                                (ev = e.val) != null &&
+                            Node last = e;
+                            if ((e = e.next) == null) {
+                                last.next = new Node(h, k, v, null);
-<
+                                if (last != f || tab.length <= 64)
-<
+                                    checkSize = true;
->
+                                if (count >= TREE_THRESHOLD)
->
+                                    replaceWithTreeBin(tab, i, k);
+                                break;
+                        synchronized (f) { f.notifyAll(); };
-<
+                if (validated) {
->
+                if (count != 0) {
+                    if (oldVal != null)
+                        return oldVal;
-+
+                    if (tab.length <= 64)
-+
+                        count = 2;
+                    break;
+        counter.add(1L);
-<
+        if (checkSize)
->
+        if (count > 1)
+            checkForResize();
+        return null;
+    /** Implementation for putIfAbsent */
+    private final Object internalPutIfAbsent(Object k, Object v) {
+        int h = spread(k.hashCode());
-+
+        int count = 0;
+        for (Node[] tab = table;;) {
+            int i; Node f; int fh; Object fk, fv;
+            if (tab == null)
+                if (casTabAt(tab, i, null, new Node(h, k, v, null)))
+                    break;
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    Object oldVal = null;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            count = 2;
->
+                            TreeNode p = t.putTreeNode(h, k, v);
->
+                            if (p != null)
->
+                                oldVal = p.val;
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (count != 0) {
->
+                        if (oldVal != null)
->
+                            return oldVal;
->
+                        break;
->
+                    }
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
+                     ((fk = f.key) == k || k.equals(fk)))
+                return fv;
+                else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
+                    Object oldVal = null;
-–
+                    boolean validated = false;
+                    try {
+                        if (tabAt(tab, i) == f) {
-<
+                            validated = true;
-<
+                            for (Node e = f;;) {
->
+                            count = 1;
->
+                            for (Node e = f;; ++count) {
+                                Object ek, ev;
+                                if ((e.hash & HASH_BITS) == h &&
+                                    (ev = e.val) != null &&
+                                Node last = e;
+                                if ((e = e.next) == null) {
+                                    last.next = new Node(h, k, v, null);
-+
+                                    if (count >= TREE_THRESHOLD)
-+
+                                        replaceWithTreeBin(tab, i, k);
+                                    break;
+                            synchronized (f) { f.notifyAll(); };
-<
+                    if (validated) {
->
+                    if (count != 0) {
+                        if (oldVal != null)
+                            return oldVal;
-+
+                        if (tab.length <= 64)
-+
+                            count = 2;
+                        break;
+        counter.add(1L);
-+
+        if (count > 1)
-+
+            checkForResize();
+        return null;
+    /** Implementation for computeIfAbsent */
+    private final Object internalComputeIfAbsent(K k,
-<
+                                                 MappingFunction<? super K, ?> mf) {
->
+                                                 Fun<? super K, ?> mf) {
+        int h = spread(k.hashCode());
+        Object val = null;
-+
+        int count = 0;
+        for (Node[] tab = table;;) {
+            Node f; int i, fh; Object fk, fv;
+            if (tab == null)
+                tab = initTable();
+            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
+                Node node = new Node(fh = h | LOCKED, k, null, null);
-–
+                boolean validated = false;
+                if (casTabAt(tab, i, null, node)) {
-<
+                    validated = true;
->
+                    count = 1;
+                    try {
-<
+                        if ((val = mf.map(k)) != null)
->
+                        if ((val = mf.apply(k)) != null)
+                            node.val = val;
+                    } finally {
+                        if (val == null)
-<
+                if (validated)
->
+                if (count != 0)
+                    break;
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    boolean added = false;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            count = 1;
->
+                            TreeNode p = t.getTreeNode(h, k, t.root);
->
+                            if (p != null)
->
+                                val = p.val;
->
+                            else if ((val = mf.apply(k)) != null) {
->
+                                added = true;
->
+                                count = 2;
->
+                                t.putTreeNode(h, k, val);
->
+                            }
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (count != 0) {
->
+                        if (!added)
->
+                            return val;
->
+                        break;
->
+                    }
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
+                     ((fk = f.key) == k || k.equals(fk)))
+                return fv;
+                    f.tryAwaitLock(tab, i);
+                else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
-<
+                    boolean validated = false;
->
+                    boolean added = false;
+                    try {
+                        if (tabAt(tab, i) == f) {
-<
+                            validated = true;
-<
+                            for (Node e = f;;) {
->
+                            count = 1;
->
+                            for (Node e = f;; ++count) {
+                                Object ek, ev;
+                                if ((e.hash & HASH_BITS) == h &&
+                                    (ev = e.val) != null &&
+                                Node last = e;
+                                if ((e = e.next) == null) {
-<
+                                    if ((val = mf.map(k)) != null)
->
+                                    if ((val = mf.apply(k)) != null) {
->
+                                        added = true;
+                                        last.next = new Node(h, k, val, null);
-+
+                                        if (count >= TREE_THRESHOLD)
-+
+                                            replaceWithTreeBin(tab, i, k);
-+
+                                    }
+                                    break;
+                            synchronized (f) { f.notifyAll(); };
-<
+                    if (validated)
->
+                    if (count != 0) {
->
+                        if (!added)
->
+                            return val;
->
+                        if (tab.length <= 64)
->
+                            count = 2;
+                        break;
-+
+                    }
-<
+        if (val == null)
-<
+            throw new NullPointerException();
-<
+        counter.add(1L);
->
+        if (val != null) {
->
+            counter.add(1L);
->
+            if (count > 1)
->
+                checkForResize();
->
+        }
+        return val;
+    /** Implementation for compute */
-<
+    @SuppressWarnings("unchecked")
-<
+    private final Object internalCompute(K k,
-<
+                                         RemappingFunction<? super K, V> mf) {
->
+    @SuppressWarnings("unchecked") private final Object internalCompute
->
+        (K k, boolean onlyIfPresent, BiFun<? super K, ? super V, ? extends V> mf) {
+        int h = spread(k.hashCode());
+        Object val = null;
-<
+        boolean added = false;
-<
+        boolean checkSize = false;
->
+        int delta = 0;
->
+        int count = 0;
+        for (Node[] tab = table;;) {
-<
+            Node f; int i, fh;
->
+            Node f; int i, fh; Object fk;
+            if (tab == null)
+                tab = initTable();
+            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
-+
+                if (onlyIfPresent)
-+
+                    break;
+                Node node = new Node(fh = h | LOCKED, k, null, null);
-–
+                boolean validated = false;
+                if (casTabAt(tab, i, null, node)) {
-–
+                    validated = true;
+                    try {
-<
+                        if ((val = mf.remap(k, null)) != null) {
->
+                        count = 1;
->
+                        if ((val = mf.apply(k, null)) != null) {
+                            node.val = val;
-<
+                            added = true;
->
+                            delta = 1;
+                    } finally {
-<
+                        if (!added)
->
+                        if (delta == 0)
+                            setTabAt(tab, i, null);
+                        if (!node.casHash(fh, h)) {
+                            node.hash = h;
-<
+                if (validated)
->
+                if (count != 0)
+                    break;
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            count = 1;
->
+                            TreeNode p = t.getTreeNode(h, k, t.root);
->
+                            Object pv = (p == null) ? null : p.val;
->
+                            if ((val = mf.apply(k, (V)pv)) != null) {
->
+                                if (p != null)
->
+                                    p.val = val;
->
+                                else {
->
+                                    count = 2;
->
+                                    delta = 1;
->
+                                    t.putTreeNode(h, k, val);
->
+                                }
->
+                            }
->
+                            else if (p != null) {
->
+                                delta = -1;
->
+                                t.deleteTreeNode(p);
->
+                            }
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (count != 0)
->
+                        break;
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & LOCKED) != 0) {
+                checkForResize();
+                f.tryAwaitLock(tab, i);
+            else if (f.casHash(fh, fh | LOCKED)) {
-–
+                boolean validated = false;
+                try {
+                    if (tabAt(tab, i) == f) {
-<
+                        validated = true;
-<
+                        for (Node e = f;;) {
->
+                        count = 1;
->
+                        for (Node e = f, pred = null;; ++count) {
+                            Object ek, ev;
+                            if ((e.hash & HASH_BITS) == h &&
+                                (ev = e.val) != null &&
+                                ((ek = e.key) == k || k.equals(ek))) {
-<
+                                val = mf.remap(k, (V)ev);
->
+                                val = mf.apply(k, (V)ev);
+                                if (val != null)
+                                    e.val = val;
-+
+                                else {
-+
+                                    delta = -1;
-+
+                                    Node en = e.next;
-+
+                                    if (pred != null)
-+
+                                        pred.next = en;
-+
+                                    else
-+
+                                        setTabAt(tab, i, en);
-+
+                                }
+                                break;
-<
+                            Node last = e;
->
+                            pred = e;
+                            if ((e = e.next) == null) {
-<
+                                if ((val = mf.remap(k, null)) != null) {
-<
+                                    last.next = new Node(h, k, val, null);
-<
+                                    added = true;
-<
+                                    if (last != f || tab.length <= 64)
-<
+                                        checkSize = true;
->
+                                if (!onlyIfPresent && (val = mf.apply(k, null)) != null) {
->
+                                    pred.next = new Node(h, k, val, null);
->
+                                    delta = 1;
->
+                                    if (count >= TREE_THRESHOLD)
->
+                                        replaceWithTreeBin(tab, i, k);
+                                break;
+                        synchronized (f) { f.notifyAll(); };
-<
+                if (validated)
->
+                if (count != 0) {
->
+                    if (tab.length <= 64)
->
+                        count = 2;
+                    break;
-+
+                }
-<
+        if (val == null)
-<
+            throw new NullPointerException();
-<
+        if (added) {
-<
+            counter.add(1L);
-<
+            if (checkSize)
->
+        if (delta != 0) {
->
+            counter.add((long)delta);
->
+            if (count > 1)
->
+                checkForResize();
->
+        }
->
+        return val;
->
+    }
->
->
+    /** Implementation for merge */
->
+    @SuppressWarnings("unchecked") private final Object internalMerge
->
+        (K k, V v, BiFun<? super V, ? super V, ? extends V> mf) {
->
+        int h = spread(k.hashCode());
->
+        Object val = null;
->
+        int delta = 0;
->
+        int count = 0;
->
+        for (Node[] tab = table;;) {
->
+            int i; Node f; int fh; Object fk, fv;
->
+            if (tab == null)
->
+                tab = initTable();
->
+            else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
->
+                if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
->
+                    delta = 1;
->
+                    val = v;
->
+                    break;
->
+                }
->
+            }
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            count = 1;
->
+                            TreeNode p = t.getTreeNode(h, k, t.root);
->
+                            val = (p == null) ? v : mf.apply((V)p.val, v);
->
+                            if (val != null) {
->
+                                if (p != null)
->
+                                    p.val = val;
->
+                                else {
->
+                                    count = 2;
->
+                                    delta = 1;
->
+                                    t.putTreeNode(h, k, val);
->
+                                }
->
+                            }
->
+                            else if (p != null) {
->
+                                delta = -1;
->
+                                t.deleteTreeNode(p);
->
+                            }
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (count != 0)
->
+                        break;
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
->
+            else if ((fh & LOCKED) != 0) {
->
+                checkForResize();
->
+                f.tryAwaitLock(tab, i);
->
+            }
->
+            else if (f.casHash(fh, fh | LOCKED)) {
->
+                try {
->
+                    if (tabAt(tab, i) == f) {
->
+                        count = 1;
->
+                        for (Node e = f, pred = null;; ++count) {
->
+                            Object ek, ev;
->
+                            if ((e.hash & HASH_BITS) == h &&
->
+                                (ev = e.val) != null &&
->
+                                ((ek = e.key) == k || k.equals(ek))) {
->
+                                val = mf.apply(v, (V)ev);
->
+                                if (val != null)
->
+                                    e.val = val;
->
+                                else {
->
+                                    delta = -1;
->
+                                    Node en = e.next;
->
+                                    if (pred != null)
->
+                                        pred.next = en;
->
+                                    else
->
+                                        setTabAt(tab, i, en);
->
+                                }
->
+                                break;
->
+                            }
->
+                            pred = e;
->
+                            if ((e = e.next) == null) {
->
+                                val = v;
->
+                                pred.next = new Node(h, k, val, null);
->
+                                delta = 1;
->
+                                if (count >= TREE_THRESHOLD)
->
+                                    replaceWithTreeBin(tab, i, k);
->
+                                break;
->
+                            }
->
+                        }
->
+                    }
->
+                } finally {
->
+                    if (!f.casHash(fh | LOCKED, fh)) {
->
+                        f.hash = fh;
->
+                        synchronized (f) { f.notifyAll(); };
->
+                    }
->
+                }
->
+                if (count != 0) {
->
+                    if (tab.length <= 64)
->
+                        count = 2;
->
+                    break;
->
+                }
->
+            }
->
+        }
->
+        if (delta != 0) {
->
+            counter.add((long)delta);
->
+            if (count > 1)
+                checkForResize();
+        return val;
+                int h = spread(k.hashCode());
+                for (Node[] tab = table;;) {
-<
+                    int i; Node f; int fh;
->
+                    int i; Node f; int fh; Object fk;
+                    if (tab == null)
+                        tab = initTable();
+                    else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
+                            break;
-<
+                    else if ((fh = f.hash) == MOVED)
-<
+                        tab = (Node[])f.key;
->
+                    else if ((fh = f.hash) == MOVED) {
->
+                        if ((fk = f.key) instanceof TreeBin) {
->
+                            TreeBin t = (TreeBin)fk;
->
+                            boolean validated = false;
->
+                            t.acquire(0);
->
+                            try {
->
+                                if (tabAt(tab, i) == f) {
->
+                                    validated = true;
->
+                                    TreeNode p = t.getTreeNode(h, k, t.root);
->
+                                    if (p != null)
->
+                                        p.val = v;
->
+                                    else {
->
+                                        t.putTreeNode(h, k, v);
->
+                                        ++delta;
->
+                                    }
->
+                                }
->
+                            } finally {
->
+                                t.release(0);
->
+                            }
->
+                            if (validated)
->
+                                break;
->
+                        }
->
+                        else
->
+                            tab = (Node[])fk;
->
+                    }
+                    else if ((fh & LOCKED) != 0) {
+                        counter.add(delta);
+                        delta = 0L;
+                        f.tryAwaitLock(tab, i);
+                    else if (f.casHash(fh, fh | LOCKED)) {
-<
+                        boolean validated = false;
-<
+                        boolean tooLong = false;
->
+                        int count = 0;
+                        try {
+                            if (tabAt(tab, i) == f) {
-<
+                                validated = true;
-<
+                                for (Node e = f;;) {
->
+                                count = 1;
->
+                                for (Node e = f;; ++count) {
+                                    Object ek, ev;
+                                    if ((e.hash & HASH_BITS) == h &&
+                                        (ev = e.val) != null &&
+                                    if ((e = e.next) == null) {
+                                        ++delta;
+                                        last.next = new Node(h, k, v, null);
-+
+                                        if (count >= TREE_THRESHOLD)
-+
+                                            replaceWithTreeBin(tab, i, k);
+                                        break;
-–
+                                    tooLong = true;
+                        } finally {
+                                synchronized (f) { f.notifyAll(); };
-<
+                        if (validated) {
-<
+                            if (tooLong) {
->
+                        if (count != 0) {
->
+                            if (count > 1) {
+                                counter.add(delta);
+                                delta = 0L;
+                                checkForResize();
+        for (int i = bin;;) {      // start upwards sweep
+            int fh; Node f;
+            if ((f = tabAt(tab, i)) == null) {
-<
+                if (bin >= 0) {    // no lock needed (or available)
->
+                if (bin >= 0) {    // Unbuffered; no lock needed (or available)
+                    if (!casTabAt(tab, i, f, fwd))
+                        continue;
+                else {             // transiently use a locked forwarding node
-<
+                    Node g =  new Node(MOVED|LOCKED, nextTab, null, null);
->
+                    Node g = new Node(MOVED|LOCKED, nextTab, null, null);
+                    if (!casTabAt(tab, i, f, g))
+                        continue;
+                    setTabAt(nextTab, i, null);
-<
+            else if (((fh = f.hash) & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) {
->
+            else if ((fh = f.hash) == MOVED) {
->
+                Object fk = f.key;
->
+                if (fk instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    boolean validated = false;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            validated = true;
->
+                            splitTreeBin(nextTab, i, t);
->
+                            setTabAt(tab, i, fwd);
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                    if (!validated)
->
+                        continue;
->
+                }
->
+            }
->
+            else if ((fh & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) {
+                boolean validated = false;
+                try {              // split to lo and hi lists; copying as needed
+                    if (tabAt(tab, i) == f) {
+                        validated = true;
-<
+                        Node e = f, lastRun = f;
-<
+                        Node lo = null, hi = null;
-<
+                        int runBit = e.hash & n;
-<
+                        for (Node p = e.next; p != null; p = p.next) {
-<
+                            int b = p.hash & n;
-<
+                            if (b != runBit) {
-<
+                                runBit = b;
-<
+                                lastRun = p;
-<
+                            }
-<
+                        }
-<
+                        if (runBit == 0)
-<
+                            lo = lastRun;
-<
+                        else
-<
+                            hi = lastRun;
-<
+                        for (Node p = e; p != lastRun; p = p.next) {
-<
+                            int ph = p.hash & HASH_BITS;
-<
+                            Object pk = p.key, pv = p.val;
-<
+                            if ((ph & n) == 0)
-<
+                                lo = new Node(ph, pk, pv, lo);
-<
+                            else
-<
+                                hi = new Node(ph, pk, pv, hi);
-<
+                        }
-<
+                        setTabAt(nextTab, i, lo);
-<
+                        setTabAt(nextTab, i + n, hi);
->
+                        splitBin(nextTab, i, f);
+                        setTabAt(tab, i, fwd);
+                } finally {
+    /**
-+
+     * Splits a normal bin with list headed by e into lo and hi parts;
-+
+     * installs in given table.
-+
+     */
-+
+    private static void splitBin(Node[] nextTab, int i, Node e) {
-+
+        int bit = nextTab.length >>> 1; // bit to split on
-+
+        int runBit = e.hash & bit;
-+
+        Node lastRun = e, lo = null, hi = null;
-+
+        for (Node p = e.next; p != null; p = p.next) {
-+
+            int b = p.hash & bit;
-+
+            if (b != runBit) {
-+
+                runBit = b;
-+
+                lastRun = p;
-+
+            }
-+
+        }
-+
+        if (runBit == 0)
-+
+            lo = lastRun;
-+
+        else
-+
+            hi = lastRun;
-+
+        for (Node p = e; p != lastRun; p = p.next) {
-+
+            int ph = p.hash & HASH_BITS;
-+
+            Object pk = p.key, pv = p.val;
-+
+            if ((ph & bit) == 0)
-+
+                lo = new Node(ph, pk, pv, lo);
-+
+            else
-+
+                hi = new Node(ph, pk, pv, hi);
-+
+        }
-+
+        setTabAt(nextTab, i, lo);
-+
+        setTabAt(nextTab, i + bit, hi);
-+
+    }
-+
-+
+    /**
-+
+     * Splits a tree bin into lo and hi parts; installs in given table.
-+
+     */
-+
+    private static void splitTreeBin(Node[] nextTab, int i, TreeBin t) {
-+
+        int bit = nextTab.length >>> 1;
-+
+        TreeBin lt = new TreeBin();
-+
+        TreeBin ht = new TreeBin();
-+
+        int lc = 0, hc = 0;
-+
+        for (Node e = t.first; e != null; e = e.next) {
-+
+            int h = e.hash & HASH_BITS;
-+
+            Object k = e.key, v = e.val;
-+
+            if ((h & bit) == 0) {
-+
+                ++lc;
-+
+                lt.putTreeNode(h, k, v);
-+
+            }
-+
+            else {
-+
+                ++hc;
-+
+                ht.putTreeNode(h, k, v);
-+
+            }
-+
+        }
-+
+        Node ln, hn; // throw away trees if too small
-+
+        if (lc <= (TREE_THRESHOLD >>> 1)) {
-+
+            ln = null;
-+
+            for (Node p = lt.first; p != null; p = p.next)
-+
+                ln = new Node(p.hash, p.key, p.val, ln);
-+
+        }
-+
+        else
-+
+            ln = new Node(MOVED, lt, null, null);
-+
+        setTabAt(nextTab, i, ln);
-+
+        if (hc <= (TREE_THRESHOLD >>> 1)) {
-+
+            hn = null;
-+
+            for (Node p = ht.first; p != null; p = p.next)
-+
+                hn = new Node(p.hash, p.key, p.val, hn);
-+
+        }
-+
+        else
-+
+            hn = new Node(MOVED, ht, null, null);
-+
+        setTabAt(nextTab, i + bit, hn);
-+
+    }
-+
-+
+    /**
+     * Implementation for clear. Steps through each bin, removing all
+     * nodes.
+     */
+        int i = 0;
+        Node[] tab = table;
+        while (tab != null && i < tab.length) {
-<
+            int fh;
->
+            int fh; Object fk;
+            Node f = tabAt(tab, i);
+            if (f == null)
+                ++i;
-<
+            else if ((fh = f.hash) == MOVED)
-<
+                tab = (Node[])f.key;
->
+            else if ((fh = f.hash) == MOVED) {
->
+                if ((fk = f.key) instanceof TreeBin) {
->
+                    TreeBin t = (TreeBin)fk;
->
+                    t.acquire(0);
->
+                    try {
->
+                        if (tabAt(tab, i) == f) {
->
+                            for (Node p = t.first; p != null; p = p.next) {
->
+                                if (p.val != null) { // (currently always true)
->
+                                    p.val = null;
->
+                                    --delta;
->
+                                }
->
+                            }
->
+                            t.first = null;
->
+                            t.root = null;
->
+                            ++i;
->
+                        }
->
+                    } finally {
->
+                        t.release(0);
->
+                    }
->
+                }
->
+                else
->
+                    tab = (Node[])fk;
->
+            }
+            else if ((fh & LOCKED) != 0) {
+                counter.add(delta); // opportunistically update count
+                delta = 0L;
+                f.tryAwaitLock(tab, i);
+            else if (f.casHash(fh, fh | LOCKED)) {
-–
+                boolean validated = false;
+                try {
+                    if (tabAt(tab, i) == f) {
-–
+                        validated = true;
+                        for (Node e = f; e != null; e = e.next) {
-<
+                            if (e.val != null) { // currently always true
->
+                            if (e.val != null) {  // (currently always true)
+                                e.val = null;
+                                --delta;
+                        setTabAt(tab, i, null);
-+
+                        ++i;
+                } finally {
+                    if (!f.casHash(fh | LOCKED, fh)) {
+                        synchronized (f) { f.notifyAll(); };
-–
+                if (validated)
-–
+                    ++i;
+        if (delta != 0)
+            counter.add(delta);
-–
+    /* ----------------Table Traversal -------------- */
+    /**
+     * Encapsulates traversal for methods such as containsValue; also
-<
+     * serves as a base class for other iterators.
->
+     * serves as a base class for other iterators and bulk tasks.
+     * At each step, the iterator snapshots the key ("nextKey") and
+     * value ("nextVal") of a valid node (i.e., one that, at point of
-<
+     * snapshot, has a nonnull user value). Because val fields can
->
+     * snapshot, has a non-null user value). Because val fields can
+     * change (including to null, indicating deletion), field nextVal
+     * might not be accurate at point of use, but still maintains the
+     * weak consistency property of holding a value that was once
-<
+     * valid.
->
+     * valid. To support iterator.remove, the nextKey field is not
->
+     * updated (nulled out) when the iterator cannot advance.
+     * Internal traversals directly access these fields, as in:
-<
+     * {@code while (it.next != null) { process(it.nextKey); it.advance(); }}
->
+     * {@code while (it.advance() != null) { process(it.nextKey); }}
-<
+     * Exported iterators (subclasses of ViewIterator) extract key,
-<
+     * value, or key-value pairs as return values of Iterator.next(),
-<
+     * and encapsulate the it.next check as hasNext();
->
+     * Exported iterators must track whether the iterator has advanced
->
+     * (in hasNext vs next) (by setting/checking/nulling field
->
+     * nextVal), and then extract key, value, or key-value pairs as
->
+     * return values of next().
+     * The iterator visits once each still-valid node that was
+     * reachable upon iterator construction. It might miss some that
+     * across threads, iteration terminates if a bounds checks fails
+     * for a table read.
-<
+     * The range-based constructor enables creation of parallel
-<
+     * range-splitting traversals. (Not yet implemented.)
->
+     * This class extends CountedCompleter to streamline parallel
->
+     * iteration in bulk operations. This adds only a few fields of
->
+     * space overhead, which is small enough in cases where it is not
->
+     * needed to not worry about it.  Because CountedCompleter is
->
+     * Serializable, but iterators need not be, we need to add warning
->
+     * suppressions.
+     */
-<
+    static class InternalIterator {
->
+    @SuppressWarnings("serial") static class Traverser<K,V,R> extends CountedCompleter<R> {
->
+        final ConcurrentHashMapV8<K, V> map;
+        Node next;           // the next entry to use
-–
+        Node last;           // the last entry used
+        Object nextKey;      // cached key field of next
+        Object nextVal;      // cached val field of next
+        Node[] tab;          // current table; updated if resized
+        int index;           // index of bin to use next
+        int baseIndex;       // current index of initial table
-<
+        final int baseLimit; // index bound for initial table
-<
+        final int baseSize;  // initial table size
->
+        int baseLimit;       // index bound for initial table
->
+        int baseSize;        // initial table size
->
+        int batch;           // split control
+        /** Creates iterator for all entries in the table. */
-<
+        InternalIterator(Node[] tab) {
-<
+            this.tab = tab;
-<
+            baseLimit = baseSize = (tab == null) ? 0 : tab.length;
-<
+            index = baseIndex = 0;
-<
+            next = null;
-<
+            advance();
-<
+        }
-<
-<
+        /** Creates iterator for the given range of the table */
-<
+        InternalIterator(Node[] tab, int lo, int hi) {
-<
+            this.tab = tab;
-<
+            baseSize = (tab == null) ? 0 : tab.length;
-<
+            baseLimit = (hi <= baseSize) ? hi : baseSize;
-<
+            index = baseIndex = (lo >= 0) ? lo : 0;
-<
+            next = null;
-<
+            advance();
-<
+        }
-<
-<
+        /** Advances next. See above for explanation. */
-<
+        final void advance() {
-<
+            Node e = last = next;
->
+        Traverser(ConcurrentHashMapV8<K, V> map) {
->
+            this.map = map;
->
+        }
->
->
+        /** Creates iterator for split() methods and task constructors */
->
+        Traverser(ConcurrentHashMapV8<K,V> map, Traverser<K,V,?> it, int batch) {
->
+            super(it);
->
+            this.batch = batch;
->
+            if ((this.map = map) != null && it != null) { // split parent
->
+                Node[] t;
->
+                if ((t = it.tab) == null &&
->
+                    (t = it.tab = map.table) != null)
->
+                    it.baseLimit = it.baseSize = t.length;
->
+                this.tab = t;
->
+                this.baseSize = it.baseSize;
->
+                int hi = this.baseLimit = it.baseLimit;
->
+                it.baseLimit = this.index = this.baseIndex =
->
+                    (hi + it.baseIndex + 1) >>> 1;
->
+            }
->
+        }
->
->
+        /**
->
+         * Advances next; returns nextVal or null if terminated.
->
+         * See above for explanation.
->
+         */
->
+        final Object advance() {
->
+            Node e = next;
->
+            Object ev = null;
+            outer: do {
+                if (e != null)                  // advance past used/skipped node
+                    e = e.next;
+                while (e == null) {             // get to next non-null bin
-<
+                    Node[] t; int b, i, n;      // checks must use locals
-<
+                    if ((b = baseIndex) >= baseLimit || (i = index) < 0 ||
-<
+                        (t = tab) == null || i >= (n = t.length))
->
+                    ConcurrentHashMapV8<K, V> m;
->
+                    Node[] t; int b, i, n; Object ek; // checks must use locals
->
+                    if ((t = tab) != null)
->
+                        n = t.length;
->
+                    else if ((m = map) != null && (t = tab = m.table) != null)
->
+                        n = baseLimit = baseSize = t.length;
->
+                    else
->
+                        break outer;
->
+                    if ((b = baseIndex) >= baseLimit ||
->
+                        (i = index) < 0 || i >= n)
+                        break outer;
-<
+                    else if ((e = tabAt(t, i)) != null && e.hash == MOVED)
-<
+                        tab = (Node[])e.key;    // restarts due to null val
-<
+                    else                        // visit upper slots if present
-<
+                        index = (i += baseSize) < n ? i : (baseIndex = b + 1);
->
+                    if ((e = tabAt(t, i)) != null && e.hash == MOVED) {
->
+                        if ((ek = e.key) instanceof TreeBin)
->
+                            e = ((TreeBin)ek).first;
->
+                        else {
->
+                            tab = (Node[])ek;
->
+                            continue;           // restarts due to null val
->
+                        }
->
+                    }                           // visit upper slots if present
->
+                    index = (i += baseSize) < n ? i : (baseIndex = b + 1);
+                nextKey = e.key;
-<
+            } while ((nextVal = e.val) == null);// skip deleted or special nodes
->
+            } while ((ev = e.val) == null);    // skip deleted or special nodes
+            next = e;
-+
+            return nextVal = ev;
-+
+        }
-+
-+
+        public final void remove() {
-+
+            Object k = nextKey;
-+
+            if (k == null && (advance() == null || (k = nextKey) == null))
-+
+                throw new IllegalStateException();
-+
+            map.internalReplace(k, null, null);
-+
+        }
-+
-+
+        public final boolean hasNext() {
-+
+            return nextVal != null || advance() != null;
-+
+        }
-+
-+
+        public final boolean hasMoreElements() { return hasNext(); }
-+
-+
+        public void compute() { } // default no-op CountedCompleter body
-+
-+
+        /**
-+
+         * Returns a batch value > 0 if this task should (and must) be
-+
+         * split, if so, adding to pending count, and in any case
-+
+         * updating batch value. The initial batch value is approx
-+
+         * exp2 of the number of times (minus one) to split task by
-+
+         * two before executing leaf action. This value is faster to
-+
+         * compute and more convenient to use as a guide to splitting
-+
+         * than is the depth, since it is used while dividing by two
-+
+         * anyway.
-+
+         */
-+
+        final int preSplit() {
-+
+            ConcurrentHashMapV8<K, V> m; int b; Node[] t;  ForkJoinPool pool;
-+
+            if ((b = batch) < 0 && (m = map) != null) { // force initialization
-+
+                if ((t = tab) == null && (t = tab = m.table) != null)
-+
+                    baseLimit = baseSize = t.length;
-+
+                if (t != null) {
-+
+                    long n = m.counter.sum();
-+
+                    int par = ((pool = getPool()) == null) ?
-+
+                        ForkJoinPool.getCommonPoolParallelism() :
-+
+                        pool.getParallelism();
-+
+                    int sp = par << 3; // slack of 8
-+
+                    b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
-+
+                }
-+
+            }
-+
+            b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1);
-+
+            if ((batch = b) > 0)
-+
+                addToPendingCount(1);
-+
+            return b;
-+
+    /* ---------------- Public operations -------------- */
+    /**
-<
+     * Creates a new, empty map with the default initial table size (16),
->
+     * Creates a new, empty map with the default initial table size (16).
+     */
+    public ConcurrentHashMapV8() {
+        this.counter = new LongAdder();
+        if (initialCapacity < concurrencyLevel)   // Use at least as many bins
+            initialCapacity = concurrencyLevel;   // as estimated threads
+        long size = (long)(1.0 + (long)initialCapacity / loadFactor);
-<
+        int cap =  ((size >= (long)MAXIMUM_CAPACITY) ?
-<
+                    MAXIMUM_CAPACITY: tableSizeFor((int)size));
->
+        int cap = (size >= (long)MAXIMUM_CAPACITY) ?
->
+            MAXIMUM_CAPACITY : tableSizeFor((int)size);
+        this.counter = new LongAdder();
+        this.sizeCtl = cap;
+    /**
-+
+     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
-+
+     * from the given type to {@code Boolean.TRUE}.
-+
+     *
-+
+     * @return the new set
-+
+     */
-+
+    public static <K> KeySetView<K,Boolean> newKeySet() {
-+
+        return new KeySetView<K,Boolean>(new ConcurrentHashMapV8<K,Boolean>(),
-+
+                                      Boolean.TRUE);
-+
+    }
-+
-+
+    /**
-+
+     * Creates a new {@link Set} backed by a ConcurrentHashMapV8
-+
+     * from the given type to {@code Boolean.TRUE}.
-+
+     *
-+
+     * @param initialCapacity The implementation performs internal
-+
+     * sizing to accommodate this many elements.
-+
+     * @throws IllegalArgumentException if the initial capacity of
-+
+     * elements is negative
-+
+     * @return the new set
-+
+     */
-+
+    public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
-+
+        return new KeySetView<K,Boolean>(new ConcurrentHashMapV8<K,Boolean>(initialCapacity),
-+
+                                      Boolean.TRUE);
-+
+    }
-+
-+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean isEmpty() {
+                (int)n);
-<
+    final long longSize() { // accurate version of size needed for views
->
+    /**
->
+     * Returns the number of mappings. This method should be used
->
+     * instead of {@link #size} because a ConcurrentHashMapV8 may
->
+     * contain more mappings than can be represented as an int. The
->
+     * value returned is an estimate; the actual count may differ if
->
+     * there are concurrent insertions or removals.
->
+     *
->
+     * @return the number of mappings
->
+     */
->
+    public long mappingCount() {
+        long n = counter.sum();
-<
+        return (n < 0L) ? 0L : n;
->
+        return (n < 0L) ? 0L : n; // ignore transient negative values
+    /**
+     * @throws NullPointerException if the specified key is null
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V get(Object key) {
->
+    @SuppressWarnings("unchecked") public V get(Object key) {
+        if (key == null)
+            throw new NullPointerException();
+        return (V)internalGet(key);
+    /**
-+
+     * Returns the value to which the specified key is mapped,
-+
+     * or the given defaultValue if this map contains no mapping for the key.
-+
+     *
-+
+     * @param key the key
-+
+     * @param defaultValue the value to return if this map contains
-+
+     * no mapping for the given key
-+
+     * @return the mapping for the key, if present; else the defaultValue
-+
+     * @throws NullPointerException if the specified key is null
-+
+     */
-+
+    @SuppressWarnings("unchecked") public V getValueOrDefault(Object key, V defaultValue) {
-+
+        if (key == null)
-+
+            throw new NullPointerException();
-+
+        V v = (V) internalGet(key);
-+
+        return v == null ? defaultValue : v;
-+
+    }
-+
-+
+    /**
+     * Tests if the specified object is a key in this table.
+     * @param  key   possible key
+        if (value == null)
+            throw new NullPointerException();
+        Object v;
-<
+        InternalIterator it = new InternalIterator(table);
-<
+        while (it.next != null) {
-<
+            if ((v = it.nextVal) == value || value.equals(v))
->
+        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
->
+        while ((v = it.advance()) != null) {
->
+            if (v == value || value.equals(v))
+                return true;
-–
+            it.advance();
+        return false;
+     * Maps the specified key to the specified value in this table.
+     * Neither the key nor the value can be null.
-<
+     * <p> The value can be retrieved by calling the {@code get} method
->
+     * <p>The value can be retrieved by calling the {@code get} method
+     * with a key that is equal to the original key.
+     * @param key key with which the specified value is to be associated
+     *         {@code null} if there was no mapping for {@code key}
+     * @throws NullPointerException if the specified key or value is null
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V put(K key, V value) {
->
+    @SuppressWarnings("unchecked") public V put(K key, V value) {
+        if (key == null || value == null)
+            throw new NullPointerException();
+        return (V)internalPut(key, value);
+     *         or {@code null} if there was no mapping for the key
+     * @throws NullPointerException if the specified key or value is null
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V putIfAbsent(K key, V value) {
->
+    @SuppressWarnings("unchecked") public V putIfAbsent(K key, V value) {
+        if (key == null || value == null)
+            throw new NullPointerException();
+        return (V)internalPutIfAbsent(key, value);
+    /**
+     * If the specified key is not already associated with a value,
-<
+     * computes its value using the given mappingFunction and
-<
+     * enters it into the map.  This is equivalent to
->
+     * computes its value using the given mappingFunction and enters
->
+     * it into the map unless null.  This is equivalent to
+     * <pre> {@code
+     * if (map.containsKey(key))
+     *   return map.get(key);
-<
+     * value = mappingFunction.map(key);
-<
+     * map.put(key, value);
->
+     * value = mappingFunction.apply(key);
->
+     * if (value != null)
->
+     *   map.put(key, value);
+     * return value;}</pre>
+     * except that the action is performed atomically.  If the
-<
+     * function returns {@code null} (in which case a {@code
-<
+     * NullPointerException} is thrown), or the function itself throws
-<
+     * an (unchecked) exception, the exception is rethrown to its
-<
+     * caller, and no mapping is recorded.  Some attempted update
-<
+     * operations on this map by other threads may be blocked while
-<
+     * computation is in progress, so the computation should be short
-<
+     * and simple, and must not attempt to update any other mappings
-<
+     * of this Map. The most appropriate usage is to construct a new
-<
+     * object serving as an initial mapped value, or memoized result,
-<
+     * as in:
->
+     * function returns {@code null} no mapping is recorded. If the
->
+     * function itself throws an (unchecked) exception, the exception
->
+     * is rethrown to its caller, and no mapping is recorded.  Some
->
+     * attempted update operations on this map by other threads may be
->
+     * blocked while computation is in progress, so the computation
->
+     * should be short and simple, and must not attempt to update any
->
+     * other mappings of this Map. The most appropriate usage is to
->
+     * construct a new object serving as an initial mapped value, or
->
+     * memoized result, as in:
+     *  <pre> {@code
-<
+     * map.computeIfAbsent(key, new MappingFunction<K, V>() {
->
+     * map.computeIfAbsent(key, new Fun<K, V>() {
+     *   public V map(K k) { return new Value(f(k)); }});}</pre>
+     * @param key key with which the specified value is to be associated
+     * @param mappingFunction the function to compute a value
+     * @return the current (existing or computed) value associated with
-<
+     *         the specified key.
-<
+     * @throws NullPointerException if the specified key, mappingFunction,
-<
+     *         or computed value is null
->
+     *         the specified key, or null if the computed value is null
->
+     * @throws NullPointerException if the specified key or mappingFunction
->
+     *         is null
+     * @throws IllegalStateException if the computation detectably
+     *         attempts a recursive update to this map that would
+     *         otherwise never complete
+     * @throws RuntimeException or Error if the mappingFunction does so,
+     *         in which case the mapping is left unestablished
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V computeIfAbsent(K key, MappingFunction<? super K, ? extends V> mappingFunction) {
->
+    @SuppressWarnings("unchecked") public V computeIfAbsent
->
+        (K key, Fun<? super K, ? extends V> mappingFunction) {
+        if (key == null || mappingFunction == null)
+            throw new NullPointerException();
+        return (V)internalComputeIfAbsent(key, mappingFunction);
+    /**
-<
+     * Computes and enters a new mapping value given a key and
->
+     * If the given key is present, computes a new mapping value given a key and
->
+     * its current mapped value. This is equivalent to
->
+     *  <pre> {@code
->
+     *   if (map.containsKey(key)) {
->
+     *     value = remappingFunction.apply(key, map.get(key));
->
+     *     if (value != null)
->
+     *       map.put(key, value);
->
+     *     else
->
+     *       map.remove(key);
->
+     *   }
->
+     * }</pre>
->
+     *
->
+     * except that the action is performed atomically.  If the
->
+     * function returns {@code null}, the mapping is removed.  If the
->
+     * function itself throws an (unchecked) exception, the exception
->
+     * is rethrown to its caller, and the current mapping is left
->
+     * unchanged.  Some attempted update operations on this map by
->
+     * other threads may be blocked while computation is in progress,
->
+     * so the computation should be short and simple, and must not
->
+     * attempt to update any other mappings of this Map. For example,
->
+     * to either create or append new messages to a value mapping:
->
+     *
->
+     * @param key key with which the specified value is to be associated
->
+     * @param remappingFunction the function to compute a value
->
+     * @return the new value associated with the specified key, or null if none
->
+     * @throws NullPointerException if the specified key or remappingFunction
->
+     *         is null
->
+     * @throws IllegalStateException if the computation detectably
->
+     *         attempts a recursive update to this map that would
->
+     *         otherwise never complete
->
+     * @throws RuntimeException or Error if the remappingFunction does so,
->
+     *         in which case the mapping is unchanged
->
+     */
->
+    @SuppressWarnings("unchecked") public V computeIfPresent
->
+        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
->
+        if (key == null || remappingFunction == null)
->
+            throw new NullPointerException();
->
+        return (V)internalCompute(key, true, remappingFunction);
->
+    }
->
->
+    /**
->
+     * Computes a new mapping value given a key and
+     * its current mapped value (or {@code null} if there is no current
+     * mapping). This is equivalent to
+     *  <pre> {@code
-<
+     *  map.put(key, remappingFunction.remap(key, map.get(key));
->
+     *   value = remappingFunction.apply(key, map.get(key));
->
+     *   if (value != null)
->
+     *     map.put(key, value);
->
+     *   else
->
+     *     map.remove(key);
+     * }</pre>
+     * except that the action is performed atomically.  If the
-<
+     * function returns {@code null} (in which case a {@code
-<
+     * NullPointerException} is thrown), or the function itself throws
-<
+     * an (unchecked) exception, the exception is rethrown to its
-<
+     * caller, and current mapping is left unchanged.  Some attempted
-<
+     * update operations on this map by other threads may be blocked
-<
+     * while computation is in progress, so the computation should be
-<
+     * short and simple, and must not attempt to update any other
-<
+     * mappings of this Map. For example, to either create or
-<
+     * append new messages to a value mapping:
->
+     * function returns {@code null}, the mapping is removed.  If the
->
+     * function itself throws an (unchecked) exception, the exception
->
+     * is rethrown to its caller, and the current mapping is left
->
+     * unchanged.  Some attempted update operations on this map by
->
+     * other threads may be blocked while computation is in progress,
->
+     * so the computation should be short and simple, and must not
->
+     * attempt to update any other mappings of this Map. For example,
->
+     * to either create or append new messages to a value mapping:
+     * <pre> {@code
+     * Map<Key, String> map = ...;
+     * final String msg = ...;
-<
+     * map.compute(key, new RemappingFunction<Key, String>() {
-<
+     *   public String remap(Key k, String v) {
->
+     * map.compute(key, new BiFun<Key, String, String>() {
->
+     *   public String apply(Key k, String v) {
+     *    return (v == null) ? msg : v + msg;});}}</pre>
+     * @param key key with which the specified value is to be associated
+     * @param remappingFunction the function to compute a value
-<
+     * @return the new value associated with
-<
+     *         the specified key.
->
+     * @return the new value associated with the specified key, or null if none
+     * @throws NullPointerException if the specified key or remappingFunction
-<
+     *         or computed value is null
->
+     *         is null
+     * @throws IllegalStateException if the computation detectably
+     *         attempts a recursive update to this map that would
+     *         otherwise never complete
+     * @throws RuntimeException or Error if the remappingFunction does so,
+     *         in which case the mapping is unchanged
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V compute(K key, RemappingFunction<? super K, V> remappingFunction) {
->
+    @SuppressWarnings("unchecked") public V compute
->
+        (K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
+        if (key == null || remappingFunction == null)
+            throw new NullPointerException();
-<
+        return (V)internalCompute(key, remappingFunction);
->
+        return (V)internalCompute(key, false, remappingFunction);
->
+    }
->
->
+    /**
->
+     * If the specified key is not already associated
->
+     * with a value, associate it with the given value.
->
+     * Otherwise, replace the value with the results of
->
+     * the given remapping function. This is equivalent to:
->
+     *  <pre> {@code
->
+     *   if (!map.containsKey(key))
->
+     *     map.put(value);
->
+     *   else {
->
+     *     newValue = remappingFunction.apply(map.get(key), value);
->
+     *     if (value != null)
->
+     *       map.put(key, value);
->
+     *     else
->
+     *       map.remove(key);
->
+     *   }
->
+     * }</pre>
->
+     * except that the action is performed atomically.  If the
->
+     * function returns {@code null}, the mapping is removed.  If the
->
+     * function itself throws an (unchecked) exception, the exception
->
+     * is rethrown to its caller, and the current mapping is left
->
+     * unchanged.  Some attempted update operations on this map by
->
+     * other threads may be blocked while computation is in progress,
->
+     * so the computation should be short and simple, and must not
->
+     * attempt to update any other mappings of this Map.
->
+     */
->
+    @SuppressWarnings("unchecked") public V merge
->
+        (K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
->
+        if (key == null || value == null || remappingFunction == null)
->
+            throw new NullPointerException();
->
+        return (V)internalMerge(key, value, remappingFunction);
+    /**
+     *         {@code null} if there was no mapping for {@code key}
+     * @throws NullPointerException if the specified key is null
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V remove(Object key) {
->
+    @SuppressWarnings("unchecked") public V remove(Object key) {
+        if (key == null)
+            throw new NullPointerException();
+        return (V)internalReplace(key, null, null);
+     *         or {@code null} if there was no mapping for the key
+     * @throws NullPointerException if the specified key or value is null
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    public V replace(K key, V value) {
->
+    @SuppressWarnings("unchecked") public V replace(K key, V value) {
+        if (key == null || value == null)
+            throw new NullPointerException();
+        return (V)internalReplace(key, value, null);
+    /**
+     * Returns a {@link Set} view of the keys contained in this map.
+     * The set is backed by the map, so changes to the map are
-<
+     * reflected in the set, and vice-versa.  The set supports element
-<
+     * removal, which removes the corresponding mapping from this map,
-<
+     * via the {@code Iterator.remove}, {@code Set.remove},
-<
+     * {@code removeAll}, {@code retainAll}, and {@code clear}
-<
+     * operations.  It does not support the {@code add} or
-<
+     * {@code addAll} operations.
->
+     * reflected in the set, and vice-versa.
-<
+     * <p>The view's {@code iterator} is a "weakly consistent" iterator
-<
+     * that will never throw {@link ConcurrentModificationException},
-<
+     * and guarantees to traverse elements as they existed upon
-<
+     * construction of the iterator, and may (but is not guaranteed to)
-<
+     * reflect any modifications subsequent to construction.
->
+     * @return the set view
+     */
-<
+    public Set<K> keySet() {
-<
+        KeySet<K,V> ks = keySet;
-<
+        return (ks != null) ? ks : (keySet = new KeySet<K,V>(this));
->
+    public KeySetView<K,V> keySet() {
->
+        KeySetView<K,V> ks = keySet;
->
+        return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
->
+    }
->
->
+    /**
->
+     * Returns a {@link Set} view of the keys in this map, using the
->
+     * given common mapped value for any additions (i.e., {@link
->
+     * Collection#add} and {@link Collection#addAll}). This is of
->
+     * course only appropriate if it is acceptable to use the same
->
+     * value for all additions from this view.
->
+     *
->
+     * @param mappedValue the mapped value to use for any
->
+     * additions.
->
+     * @return the set view
->
+     * @throws NullPointerException if the mappedValue is null
->
+     */
->
+    public KeySetView<K,V> keySet(V mappedValue) {
->
+        if (mappedValue == null)
->
+            throw new NullPointerException();
->
+        return new KeySetView<K,V>(this, mappedValue);
+    /**
+     * Returns a {@link Collection} view of the values contained in this map.
+     * The collection is backed by the map, so changes to the map are
-<
+     * reflected in the collection, and vice-versa.  The collection
-<
+     * supports element removal, which removes the corresponding
-<
+     * mapping from this map, via the {@code Iterator.remove},
-<
+     * {@code Collection.remove}, {@code removeAll},
-<
+     * {@code retainAll}, and {@code clear} operations.  It does not
-<
+     * support the {@code add} or {@code addAll} operations.
-<
+     *
-<
+     * <p>The view's {@code iterator} is a "weakly consistent" iterator
-<
+     * that will never throw {@link ConcurrentModificationException},
-<
+     * and guarantees to traverse elements as they existed upon
-<
+     * construction of the iterator, and may (but is not guaranteed to)
-<
+     * reflect any modifications subsequent to construction.
->
+     * reflected in the collection, and vice-versa.
+     */
-<
+    public Collection<V> values() {
-<
+        Values<K,V> vs = values;
-<
+        return (vs != null) ? vs : (values = new Values<K,V>(this));
->
+    public ValuesView<K,V> values() {
->
+        ValuesView<K,V> vs = values;
->
+        return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
+    /**
+     * reflect any modifications subsequent to construction.
+     */
+    public Set<Map.Entry<K,V>> entrySet() {
-<
+        EntrySet<K,V> es = entrySet;
-<
+        return (es != null) ? es : (entrySet = new EntrySet<K,V>(this));
->
+        EntrySetView<K,V> es = entrySet;
->
+        return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
+    /**
+    /**
-+
+     * Returns a partitionable iterator of the keys in this map.
-+
+     *
-+
+     * @return a partitionable iterator of the keys in this map
-+
+     */
-+
+    public Spliterator<K> keySpliterator() {
-+
+        return new KeyIterator<K,V>(this);
-+
+    }
-+
-+
+    /**
-+
+     * Returns a partitionable iterator of the values in this map.
-+
+     *
-+
+     * @return a partitionable iterator of the values in this map
-+
+     */
-+
+    public Spliterator<V> valueSpliterator() {
-+
+        return new ValueIterator<K,V>(this);
-+
+    }
-+
-+
+    /**
-+
+     * Returns a partitionable iterator of the entries in this map.
-+
+     *
-+
+     * @return a partitionable iterator of the entries in this map
-+
+     */
-+
+    public Spliterator<Map.Entry<K,V>> entrySpliterator() {
-+
+        return new EntryIterator<K,V>(this);
-+
+    }
-+
-+
+    /**
+     * Returns the hash code value for this {@link Map}, i.e.,
+     * the sum of, for each key-value pair in the map,
+     * {@code key.hashCode() ^ value.hashCode()}.
+     */
+    public int hashCode() {
+        int h = 0;
-<
+        InternalIterator it = new InternalIterator(table);
-<
+        while (it.next != null) {
-<
+            h += it.nextKey.hashCode() ^ it.nextVal.hashCode();
-<
+            it.advance();
->
+        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
->
+        Object v;
->
+        while ((v = it.advance()) != null) {
->
+            h += it.nextKey.hashCode() ^ v.hashCode();
+        return h;
+     * @return a string representation of this map
+     */
+    public String toString() {
-<
+        InternalIterator it = new InternalIterator(table);
->
+        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
+        StringBuilder sb = new StringBuilder();
+        sb.append('{');
-<
+        if (it.next != null) {
->
+        Object v;
->
+        if ((v = it.advance()) != null) {
+            for (;;) {
-<
+                Object k = it.nextKey, v = it.nextVal;
->
+                Object k = it.nextKey;
+                sb.append(k == this ? "(this Map)" : k);
+                sb.append('=');
+                sb.append(v == this ? "(this Map)" : v);
-<
+                it.advance();
-<
+                if (it.next == null)
->
+                if ((v = it.advance()) == null)
+                    break;
+                sb.append(',').append(' ');
+            if (!(o instanceof Map))
+                return false;
+            Map<?,?> m = (Map<?,?>) o;
-<
+            InternalIterator it = new InternalIterator(table);
-<
+            while (it.next != null) {
-<
+                Object val = it.nextVal;
->
+            Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
->
+            Object val;
->
+            while ((val = it.advance()) != null) {
+                Object v = m.get(it.nextKey);
+                if (v == null || (v != val && !v.equals(val)))
+                    return false;
-–
+                it.advance();
+            for (Map.Entry<?,?> e : m.entrySet()) {
+                Object mk, mv, v;
+    /* ----------------Iterators -------------- */
-<
+    /**
-<
+     * Base class for key, value, and entry iterators.  Adds a map
-<
+     * reference to InternalIterator to support Iterator.remove.
-<
+     */
-<
+    static abstract class ViewIterator<K,V> extends InternalIterator {
-<
+        final ConcurrentHashMapV8<K, V> map;
-<
+        ViewIterator(ConcurrentHashMapV8<K, V> map) {
-<
+            super(map.table);
-<
+            this.map = map;
->
+    @SuppressWarnings("serial") static final class KeyIterator<K,V> extends Traverser<K,V,Object>
->
+        implements Spliterator<K>, Enumeration<K> {
->
+        KeyIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
->
+        KeyIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
->
+            super(map, it, -1);
-<
-<
+        public final void remove() {
-<
+            if (last == null)
->
+        public KeyIterator<K,V> split() {
->
+            if (nextKey != null)
+                throw new IllegalStateException();
-<
+            map.remove(last.key);
-<
+            last = null;
->
+            return new KeyIterator<K,V>(map, this);
-<
-<
+        public final boolean hasNext()         { return next != null; }
-<
+        public final boolean hasMoreElements() { return next != null; }
-<
+    }
-<
-<
+    static final class KeyIterator<K,V> extends ViewIterator<K,V>
-<
+        implements Iterator<K>, Enumeration<K> {
-<
+        KeyIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
-<
-<
+        @SuppressWarnings("unchecked")
-<
+        public final K next() {
-<
+            if (next == null)
->
+        @SuppressWarnings("unchecked") public final K next() {
->
+            if (nextVal == null && advance() == null)
+                throw new NoSuchElementException();
+            Object k = nextKey;
-<
+            advance();
-<
+            return (K)k;
->
+            nextVal = null;
->
+            return (K) k;
+        public final K nextElement() { return next(); }
-<
+    static final class ValueIterator<K,V> extends ViewIterator<K,V>
-<
+        implements Iterator<V>, Enumeration<V> {
->
+    @SuppressWarnings("serial") static final class ValueIterator<K,V> extends Traverser<K,V,Object>
->
+        implements Spliterator<V>, Enumeration<V> {
+        ValueIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
-+
+        ValueIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
-+
+            super(map, it, -1);
-+
+        }
-+
+        public ValueIterator<K,V> split() {
-+
+            if (nextKey != null)
-+
+                throw new IllegalStateException();
-+
+            return new ValueIterator<K,V>(map, this);
-+
+        }
-<
+        @SuppressWarnings("unchecked")
-<
+        public final V next() {
-<
+            if (next == null)
->
+        @SuppressWarnings("unchecked") public final V next() {
->
+            Object v;
->
+            if ((v = nextVal) == null && (v = advance()) == null)
+                throw new NoSuchElementException();
-<
+            Object v = nextVal;
-<
+            advance();
-<
+            return (V)v;
->
+            nextVal = null;
->
+            return (V) v;
+        public final V nextElement() { return next(); }
-<
+    static final class EntryIterator<K,V> extends ViewIterator<K,V>
-<
+        implements Iterator<Map.Entry<K,V>> {
->
+    @SuppressWarnings("serial") static final class EntryIterator<K,V> extends Traverser<K,V,Object>
->
+        implements Spliterator<Map.Entry<K,V>> {
+        EntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
-<
-<
+        @SuppressWarnings("unchecked")
-<
+        public final Map.Entry<K,V> next() {
-<
+            if (next == null)
-<
+                throw new NoSuchElementException();
-<
+            Object k = nextKey;
-<
+            Object v = nextVal;
-<
+            advance();
-<
+            return new WriteThroughEntry<K,V>((K)k, (V)v, map);
->
+        EntryIterator(ConcurrentHashMapV8<K, V> map, Traverser<K,V,Object> it) {
->
+            super(map, it, -1);
->
+        }
->
+        public EntryIterator<K,V> split() {
->
+            if (nextKey != null)
->
+                throw new IllegalStateException();
->
+            return new EntryIterator<K,V>(map, this);
-–
+    }
-–
-–
+    static final class SnapshotEntryIterator<K,V> extends ViewIterator<K,V>
-–
+        implements Iterator<Map.Entry<K,V>> {
-–
+        SnapshotEntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
-<
+        @SuppressWarnings("unchecked")
-<
+        public final Map.Entry<K,V> next() {
-<
+            if (next == null)
->
+        @SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
->
+            Object v;
->
+            if ((v = nextVal) == null && (v = advance()) == null)
+                throw new NoSuchElementException();
+            Object k = nextKey;
-<
+            Object v = nextVal;
-<
+            advance();
-<
+            return new SnapshotEntry<K,V>((K)k, (V)v);
->
+            nextVal = null;
->
+            return new MapEntry<K,V>((K)k, (V)v, map);
+    /**
-<
+     * Base of writeThrough and Snapshot entry classes
->
+     * Exported Entry for iterators
+     */
-<
+    static abstract class MapEntry<K,V> implements Map.Entry<K, V> {
->
+    static final class MapEntry<K,V> implements Map.Entry<K, V> {
+        final K key; // non-null
+        V val;       // non-null
-<
+        MapEntry(K key, V val)        { this.key = key; this.val = val; }
->
+        final ConcurrentHashMapV8<K, V> map;
->
+        MapEntry(K key, V val, ConcurrentHashMapV8<K, V> map) {
->
+            this.key = key;
->
+            this.val = val;
->
+            this.map = map;
->
+        }
+        public final K getKey()       { return key; }
+        public final V getValue()     { return val; }
+        public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
+                    (v == val || v.equals(val)));
-–
+        public abstract V setValue(V value);
-–
+    }
-–
-–
+    /**
-–
+     * Entry used by EntryIterator.next(), that relays setValue
-–
+     * changes to the underlying map.
-–
+     */
-–
+    static final class WriteThroughEntry<K,V> extends MapEntry<K,V>
-–
+        implements Map.Entry<K, V> {
-–
+        final ConcurrentHashMapV8<K, V> map;
-–
+        WriteThroughEntry(K key, V val, ConcurrentHashMapV8<K, V> map) {
-–
+            super(key, val);
-–
+            this.map = map;
-–
+        }
-–
+        /**
+         * Sets our entry's value and writes through to the map. The
-<
+         * value to return is somewhat arbitrary here. Since a
-<
+         * WriteThroughEntry does not necessarily track asynchronous
-<
+         * changes, the most recent "previous" value could be
-<
+         * different from what we return (or could even have been
-<
+         * removed in which case the put will re-establish). We do not
-<
+         * and cannot guarantee more.
->
+         * value to return is somewhat arbitrary here. Since we do not
->
+         * necessarily track asynchronous changes, the most recent
->
+         * "previous" value could be different from what we return (or
->
+         * could even have been removed in which case the put will
->
+         * re-establish). We do not and cannot guarantee more.
+         */
+        public final V setValue(V value) {
+            if (value == null) throw new NullPointerException();
+    /**
-<
+     * Internal version of entry, that doesn't write though changes
->
+     * Returns exportable snapshot entry for the given key and value
->
+     * when write-through can't or shouldn't be used.
+     */
-<
+    static final class SnapshotEntry<K,V> extends MapEntry<K,V>
-<
+        implements Map.Entry<K, V> {
-<
+        SnapshotEntry(K key, V val) { super(key, val); }
-<
+        public final V setValue(V value) { // only locally update
-<
+            if (value == null) throw new NullPointerException();
-<
+            V v = val;
-<
+            val = value;
-<
+            return v;
->
+    static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
->
+        return new AbstractMap.SimpleEntry<K,V>(k, v);
->
+    }
->
->
+    /* ---------------- Serialization Support -------------- */
->
->
+    /**
->
+     * Stripped-down version of helper class used in previous version,
->
+     * declared for the sake of serialization compatibility
->
+     */
->
+    static class Segment<K,V> implements Serializable {
->
+        private static final long serialVersionUID = 2249069246763182397L;
->
+        final float loadFactor;
->
+        Segment(float lf) { this.loadFactor = lf; }
->
+    }
->
->
+    /**
->
+     * Saves the state of the {@code ConcurrentHashMapV8} instance to a
->
+     * stream (i.e., serializes it).
->
+     * @param s the stream
->
+     * @serialData
->
+     * the key (Object) and value (Object)
->
+     * for each key-value mapping, followed by a null pair.
->
+     * The key-value mappings are emitted in no particular order.
->
+     */
->
+    @SuppressWarnings("unchecked") private void writeObject(java.io.ObjectOutputStream s)
->
+        throws java.io.IOException {
->
+        if (segments == null) { // for serialization compatibility
->
+            segments = (Segment<K,V>[])
->
+                new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
->
+            for (int i = 0; i < segments.length; ++i)
->
+                segments[i] = new Segment<K,V>(LOAD_FACTOR);
->
+        }
->
+        s.defaultWriteObject();
->
+        Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
->
+        Object v;
->
+        while ((v = it.advance()) != null) {
->
+            s.writeObject(it.nextKey);
->
+            s.writeObject(v);
-+
+        s.writeObject(null);
-+
+        s.writeObject(null);
-+
+        segments = null; // throw away
-+
+    }
-+
-+
+    /**
-+
+     * Reconstitutes the instance from a stream (that is, deserializes it).
-+
+     * @param s the stream
-+
+     */
-+
+    @SuppressWarnings("unchecked") private void readObject(java.io.ObjectInputStream s)
-+
+        throws java.io.IOException, ClassNotFoundException {
-+
+        s.defaultReadObject();
-+
+        this.segments = null; // unneeded
-+
+        // initialize transient final field
-+
+        UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
-+
-+
+        // Create all nodes, then place in table once size is known
-+
+        long size = 0L;
-+
+        Node p = null;
-+
+        for (;;) {
-+
+            K k = (K) s.readObject();
-+
+            V v = (V) s.readObject();
-+
+            if (k != null && v != null) {
-+
+                int h = spread(k.hashCode());
-+
+                p = new Node(h, k, v, p);
-+
+                ++size;
-+
+            }
-+
+            else
-+
+                break;
-+
+        }
-+
+        if (p != null) {
-+
+            boolean init = false;
-+
+            int n;
-+
+            if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
-+
+                n = MAXIMUM_CAPACITY;
-+
+            else {
-+
+                int sz = (int)size;
-+
+                n = tableSizeFor(sz + (sz >>> 1) + 1);
-+
+            }
-+
+            int sc = sizeCtl;
-+
+            boolean collide = false;
-+
+            if (n > sc &&
-+
+                UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
-+
+                try {
-+
+                    if (table == null) {
-+
+                        init = true;
-+
+                        Node[] tab = new Node[n];
-+
+                        int mask = n - 1;
-+
+                        while (p != null) {
-+
+                            int j = p.hash & mask;
-+
+                            Node next = p.next;
-+
+                            Node q = p.next = tabAt(tab, j);
-+
+                            setTabAt(tab, j, p);
-+
+                            if (!collide && q != null && q.hash == p.hash)
-+
+                                collide = true;
-+
+                            p = next;
-+
+                        }
-+
+                        table = tab;
-+
+                        counter.add(size);
-+
+                        sc = n - (n >>> 2);
-+
+                    }
-+
+                } finally {
-+
+                    sizeCtl = sc;
-+
+                }
-+
+                if (collide) { // rescan and convert to TreeBins
-+
+                    Node[] tab = table;
-+
+                    for (int i = 0; i < tab.length; ++i) {
-+
+                        int c = 0;
-+
+                        for (Node e = tabAt(tab, i); e != null; e = e.next) {
-+
+                            if (++c > TREE_THRESHOLD &&
-+
+                                (e.key instanceof Comparable)) {
-+
+                                replaceWithTreeBin(tab, i, e.key);
-+
+                                break;
-+
+                            }
-+
+                        }
-+
+                    }
-+
+                }
-+
+            }
-+
+            if (!init) { // Can only happen if unsafely published.
-+
+                while (p != null) {
-+
+                    internalPut(p.key, p.val);
-+
+                    p = p.next;
-+
+                }
-+
+            }
-+
+        }
-+
+    }
-+
-+
-+
+    // -------------------------------------------------------
-+
-+
+    // Sams
-+
+    /** Interface describing a void action of one argument */
-+
+    public interface Action<A> { void apply(A a); }
-+
+    /** Interface describing a void action of two arguments */
-+
+    public interface BiAction<A,B> { void apply(A a, B b); }
-+
+    /** Interface describing a function of one argument */
-+
+    public interface Fun<A,T> { T apply(A a); }
-+
+    /** Interface describing a function of two arguments */
-+
+    public interface BiFun<A,B,T> { T apply(A a, B b); }
-+
+    /** Interface describing a function of no arguments */
-+
+    public interface Generator<T> { T apply(); }
-+
+    /** Interface describing a function mapping its argument to a double */
-+
+    public interface ObjectToDouble<A> { double apply(A a); }
-+
+    /** Interface describing a function mapping its argument to a long */
-+
+    public interface ObjectToLong<A> { long apply(A a); }
-+
+    /** Interface describing a function mapping its argument to an int */
-+
+    public interface ObjectToInt<A> {int apply(A a); }
-+
+    /** Interface describing a function mapping two arguments to a double */
-+
+    public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
-+
+    /** Interface describing a function mapping two arguments to a long */
-+
+    public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
-+
+    /** Interface describing a function mapping two arguments to an int */
-+
+    public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
-+
+    /** Interface describing a function mapping a double to a double */
-+
+    public interface DoubleToDouble { double apply(double a); }
-+
+    /** Interface describing a function mapping a long to a long */
-+
+    public interface LongToLong { long apply(long a); }
-+
+    /** Interface describing a function mapping an int to an int */
-+
+    public interface IntToInt { int apply(int a); }
-+
+    /** Interface describing a function mapping two doubles to a double */
-+
+    public interface DoubleByDoubleToDouble { double apply(double a, double b); }
-+
+    /** Interface describing a function mapping two longs to a long */
-+
+    public interface LongByLongToLong { long apply(long a, long b); }
-+
+    /** Interface describing a function mapping two ints to an int */
-+
+    public interface IntByIntToInt { int apply(int a, int b); }
-+
-+
-+
+    // -------------------------------------------------------
-+
-+
+    /**
-+
+     * Performs the given action for each (key, value).
-+
+     *
-+
+     * @param action the action
-+
+     */
-+
+    public void forEach(BiAction<K,V> action) {
-+
+        ForkJoinTasks.forEach
-+
+            (this, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each non-null transformation
-+
+     * of each (key, value).
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case the action is not applied).
-+
+     * @param action the action
-+
+     */
-+
+    public <U> void forEach(BiFun<? super K, ? super V, ? extends U> transformer,
-+
+                            Action<U> action) {
-+
+        ForkJoinTasks.forEach
-+
+            (this, transformer, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns a non-null result from applying the given search
-+
+     * function on each (key, value), or null if none.  Upon
-+
+     * success, further element processing is suppressed and the
-+
+     * results of any other parallel invocations of the search
-+
+     * function are ignored.
-+
+     *
-+
+     * @param searchFunction a function returning a non-null
-+
+     * result on success, else null
-+
+     * @return a non-null result from applying the given search
-+
+     * function on each (key, value), or null if none
-+
+     */
-+
+    public <U> U search(BiFun<? super K, ? super V, ? extends U> searchFunction) {
-+
+        return ForkJoinTasks.search
-+
+            (this, searchFunction).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all (key, value) pairs using the given reducer to
-+
+     * combine values, or null if none.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case it is not combined).
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all (key, value) pairs
-+
+     */
-+
+    public <U> U reduce(BiFun<? super K, ? super V, ? extends U> transformer,
-+
+                        BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+        return ForkJoinTasks.reduce
-+
+            (this, transformer, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all (key, value) pairs using the given reducer to
-+
+     * combine values, and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all (key, value) pairs
-+
+     */
-+
+    public double reduceToDouble(ObjectByObjectToDouble<? super K, ? super V> transformer,
-+
+                                 double basis,
-+
+                                 DoubleByDoubleToDouble reducer) {
-+
+        return ForkJoinTasks.reduceToDouble
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all (key, value) pairs using the given reducer to
-+
+     * combine values, and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all (key, value) pairs
-+
+     */
-+
+    public long reduceToLong(ObjectByObjectToLong<? super K, ? super V> transformer,
-+
+                             long basis,
-+
+                             LongByLongToLong reducer) {
-+
+        return ForkJoinTasks.reduceToLong
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all (key, value) pairs using the given reducer to
-+
+     * combine values, and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all (key, value) pairs
-+
+     */
-+
+    public int reduceToInt(ObjectByObjectToInt<? super K, ? super V> transformer,
-+
+                           int basis,
-+
+                           IntByIntToInt reducer) {
-+
+        return ForkJoinTasks.reduceToInt
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each key.
-+
+     *
-+
+     * @param action the action
-+
+     */
-+
+    public void forEachKey(Action<K> action) {
-+
+        ForkJoinTasks.forEachKey
-+
+            (this, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each non-null transformation
-+
+     * of each key.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case the action is not applied).
-+
+     * @param action the action
-+
+     */
-+
+    public <U> void forEachKey(Fun<? super K, ? extends U> transformer,
-+
+                               Action<U> action) {
-+
+        ForkJoinTasks.forEachKey
-+
+            (this, transformer, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns a non-null result from applying the given search
-+
+     * function on each key, or null if none. Upon success,
-+
+     * further element processing is suppressed and the results of
-+
+     * any other parallel invocations of the search function are
-+
+     * ignored.
-+
+     *
-+
+     * @param searchFunction a function returning a non-null
-+
+     * result on success, else null
-+
+     * @return a non-null result from applying the given search
-+
+     * function on each key, or null if none
-+
+     */
-+
+    public <U> U searchKeys(Fun<? super K, ? extends U> searchFunction) {
-+
+        return ForkJoinTasks.searchKeys
-+
+            (this, searchFunction).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating all keys using the given
-+
+     * reducer to combine values, or null if none.
-+
+     *
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating all keys using the given
-+
+     * reducer to combine values, or null if none
-+
+     */
-+
+    public K reduceKeys(BiFun<? super K, ? super K, ? extends K> reducer) {
-+
+        return ForkJoinTasks.reduceKeys
-+
+            (this, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all keys using the given reducer to combine values, or
-+
+     * null if none.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case it is not combined).
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all keys
-+
+     */
-+
+    public <U> U reduceKeys(Fun<? super K, ? extends U> transformer,
-+
+                            BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+        return ForkJoinTasks.reduceKeys
-+
+            (this, transformer, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all keys using the given reducer to combine values, and
-+
+     * the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return  the result of accumulating the given transformation
-+
+     * of all keys
-+
+     */
-+
+    public double reduceKeysToDouble(ObjectToDouble<? super K> transformer,
-+
+                                     double basis,
-+
+                                     DoubleByDoubleToDouble reducer) {
-+
+        return ForkJoinTasks.reduceKeysToDouble
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all keys using the given reducer to combine values, and
-+
+     * the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all keys
-+
+     */
-+
+    public long reduceKeysToLong(ObjectToLong<? super K> transformer,
-+
+                                 long basis,
-+
+                                 LongByLongToLong reducer) {
-+
+        return ForkJoinTasks.reduceKeysToLong
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all keys using the given reducer to combine values, and
-+
+     * the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all keys
-+
+     */
-+
+    public int reduceKeysToInt(ObjectToInt<? super K> transformer,
-+
+                               int basis,
-+
+                               IntByIntToInt reducer) {
-+
+        return ForkJoinTasks.reduceKeysToInt
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each value.
-+
+     *
-+
+     * @param action the action
-+
+     */
-+
+    public void forEachValue(Action<V> action) {
-+
+        ForkJoinTasks.forEachValue
-+
+            (this, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each non-null transformation
-+
+     * of each value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case the action is not applied).
-+
+     */
-+
+    public <U> void forEachValue(Fun<? super V, ? extends U> transformer,
-+
+                                 Action<U> action) {
-+
+        ForkJoinTasks.forEachValue
-+
+            (this, transformer, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns a non-null result from applying the given search
-+
+     * function on each value, or null if none.  Upon success,
-+
+     * further element processing is suppressed and the results of
-+
+     * any other parallel invocations of the search function are
-+
+     * ignored.
-+
+     *
-+
+     * @param searchFunction a function returning a non-null
-+
+     * result on success, else null
-+
+     * @return a non-null result from applying the given search
-+
+     * function on each value, or null if none
-+
+     *
-+
+     */
-+
+    public <U> U searchValues(Fun<? super V, ? extends U> searchFunction) {
-+
+        return ForkJoinTasks.searchValues
-+
+            (this, searchFunction).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating all values using the
-+
+     * given reducer to combine values, or null if none.
-+
+     *
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return  the result of accumulating all values
-+
+     */
-+
+    public V reduceValues(BiFun<? super V, ? super V, ? extends V> reducer) {
-+
+        return ForkJoinTasks.reduceValues
-+
+            (this, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all values using the given reducer to combine values, or
-+
+     * null if none.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case it is not combined).
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all values
-+
+     */
-+
+    public <U> U reduceValues(Fun<? super V, ? extends U> transformer,
-+
+                              BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+        return ForkJoinTasks.reduceValues
-+
+            (this, transformer, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all values using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all values
-+
+     */
-+
+    public double reduceValuesToDouble(ObjectToDouble<? super V> transformer,
-+
+                                       double basis,
-+
+                                       DoubleByDoubleToDouble reducer) {
-+
+        return ForkJoinTasks.reduceValuesToDouble
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all values using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all values
-+
+     */
-+
+    public long reduceValuesToLong(ObjectToLong<? super V> transformer,
-+
+                                   long basis,
-+
+                                   LongByLongToLong reducer) {
-+
+        return ForkJoinTasks.reduceValuesToLong
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all values using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all values
-+
+     */
-+
+    public int reduceValuesToInt(ObjectToInt<? super V> transformer,
-+
+                                 int basis,
-+
+                                 IntByIntToInt reducer) {
-+
+        return ForkJoinTasks.reduceValuesToInt
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each entry.
-+
+     *
-+
+     * @param action the action
-+
+     */
-+
+    public void forEachEntry(Action<Map.Entry<K,V>> action) {
-+
+        ForkJoinTasks.forEachEntry
-+
+            (this, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Performs the given action for each non-null transformation
-+
+     * of each entry.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case the action is not applied).
-+
+     * @param action the action
-+
+     */
-+
+    public <U> void forEachEntry(Fun<Map.Entry<K,V>, ? extends U> transformer,
-+
+                                 Action<U> action) {
-+
+        ForkJoinTasks.forEachEntry
-+
+            (this, transformer, action).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns a non-null result from applying the given search
-+
+     * function on each entry, or null if none.  Upon success,
-+
+     * further element processing is suppressed and the results of
-+
+     * any other parallel invocations of the search function are
-+
+     * ignored.
-+
+     *
-+
+     * @param searchFunction a function returning a non-null
-+
+     * result on success, else null
-+
+     * @return a non-null result from applying the given search
-+
+     * function on each entry, or null if none
-+
+     */
-+
+    public <U> U searchEntries(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
-+
+        return ForkJoinTasks.searchEntries
-+
+            (this, searchFunction).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating all entries using the
-+
+     * given reducer to combine values, or null if none.
-+
+     *
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating all entries
-+
+     */
-+
+    public Map.Entry<K,V> reduceEntries(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
-+
+        return ForkJoinTasks.reduceEntries
-+
+            (this, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all entries using the given reducer to combine values,
-+
+     * or null if none.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element, or null of there is no transformation (in
-+
+     * which case it is not combined).
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all entries
-+
+     */
-+
+    public <U> U reduceEntries(Fun<Map.Entry<K,V>, ? extends U> transformer,
-+
+                               BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+        return ForkJoinTasks.reduceEntries
-+
+            (this, transformer, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all entries using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all entries
-+
+     */
-+
+    public double reduceEntriesToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
-+
+                                        double basis,
-+
+                                        DoubleByDoubleToDouble reducer) {
-+
+        return ForkJoinTasks.reduceEntriesToDouble
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all entries using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return  the result of accumulating the given transformation
-+
+     * of all entries
-+
+     */
-+
+    public long reduceEntriesToLong(ObjectToLong<Map.Entry<K,V>> transformer,
-+
+                                    long basis,
-+
+                                    LongByLongToLong reducer) {
-+
+        return ForkJoinTasks.reduceEntriesToLong
-+
+            (this, transformer, basis, reducer).invoke();
-+
+    }
-+
-+
+    /**
-+
+     * Returns the result of accumulating the given transformation
-+
+     * of all entries using the given reducer to combine values,
-+
+     * and the given basis as an identity value.
-+
+     *
-+
+     * @param transformer a function returning the transformation
-+
+     * for an element
-+
+     * @param basis the identity (initial default value) for the reduction
-+
+     * @param reducer a commutative associative combining function
-+
+     * @return the result of accumulating the given transformation
-+
+     * of all entries
-+
+     */
-+
+    public int reduceEntriesToInt(ObjectToInt<Map.Entry<K,V>> transformer,
-+
+                                  int basis,
-+
+                                  IntByIntToInt reducer) {
-+
+        return ForkJoinTasks.reduceEntriesToInt
-+
+            (this, transformer, basis, reducer).invoke();
+    /* ----------------Views -------------- */
+    /**
-<
+     * Base class for views. This is done mainly to allow adding
-<
+     * customized parallel traversals (not yet implemented.)
->
+     * Base class for views.
+     */
-<
+    static abstract class MapView<K, V> {
->
+    static abstract class CHMView<K, V> {
+        final ConcurrentHashMapV8<K, V> map;
-<
+        MapView(ConcurrentHashMapV8<K, V> map)  { this.map = map; }
->
+        CHMView(ConcurrentHashMapV8<K, V> map)  { this.map = map; }
->
->
+        /**
->
+         * Returns the map backing this view.
->
+         *
->
+         * @return the map backing this view
->
+         */
->
+        public ConcurrentHashMapV8<K,V> getMap() { return map; }
->
+        public final int size()                 { return map.size(); }
+        public final boolean isEmpty()          { return map.isEmpty(); }
+        public final void clear()               { map.clear(); }
+        // implementations below rely on concrete classes supplying these
-<
+        abstract Iterator<?> iter();
->
+        abstract public Iterator<?> iterator();
+        abstract public boolean contains(Object o);
+        abstract public boolean remove(Object o);
+        private static final String oomeMsg = "Required array size too large";
+        public final Object[] toArray() {
-<
+            long sz = map.longSize();
->
+            long sz = map.mappingCount();
+            if (sz > (long)(MAX_ARRAY_SIZE))
+                throw new OutOfMemoryError(oomeMsg);
+            int n = (int)sz;
+            Object[] r = new Object[n];
+            int i = 0;
-<
+            Iterator<?> it = iter();
->
+            Iterator<?> it = iterator();
+            while (it.hasNext()) {
+                if (i == n) {
+                    if (n >= MAX_ARRAY_SIZE)
+            return (i == n) ? r : Arrays.copyOf(r, i);
-<
+        @SuppressWarnings("unchecked")
-<
+        public final <T> T[] toArray(T[] a) {
-<
+            long sz = map.longSize();
->
+        @SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
->
+            long sz = map.mappingCount();
+            if (sz > (long)(MAX_ARRAY_SIZE))
+                throw new OutOfMemoryError(oomeMsg);
+            int m = (int)sz;
+                .newInstance(a.getClass().getComponentType(), m);
+            int n = r.length;
+            int i = 0;
-<
+            Iterator<?> it = iter();
->
+            Iterator<?> it = iterator();
+            while (it.hasNext()) {
+                if (i == n) {
+                    if (n >= MAX_ARRAY_SIZE)
+        public final int hashCode() {
+            int h = 0;
-<
+            for (Iterator<?> it = iter(); it.hasNext();)
->
+            for (Iterator<?> it = iterator(); it.hasNext();)
+                h += it.next().hashCode();
+            return h;
+        public final String toString() {
+            StringBuilder sb = new StringBuilder();
+            sb.append('[');
-<
+            Iterator<?> it = iter();
->
+            Iterator<?> it = iterator();
+            if (it.hasNext()) {
+                for (;;) {
+                    Object e = it.next();
+            return true;
-<
+        public final boolean removeAll(Collection c) {
->
+        public final boolean removeAll(Collection<?> c) {
+            boolean modified = false;
-<
+            for (Iterator<?> it = iter(); it.hasNext();) {
->
+            for (Iterator<?> it = iterator(); it.hasNext();) {
+                if (c.contains(it.next())) {
+                    it.remove();
+                    modified = true;
+        public final boolean retainAll(Collection<?> c) {
+            boolean modified = false;
-<
+            for (Iterator<?> it = iter(); it.hasNext();) {
->
+            for (Iterator<?> it = iterator(); it.hasNext();) {
+                if (!c.contains(it.next())) {
+                    it.remove();
+                    modified = true;
-<
+    static final class KeySet<K,V> extends MapView<K,V> implements Set<K> {
-<
+        KeySet(ConcurrentHashMapV8<K, V> map)   { super(map); }
-<
+        public final boolean contains(Object o) { return map.containsKey(o); }
-<
+        public final boolean remove(Object o)   { return map.remove(o) != null; }
-<
-<
+        public final Iterator<K> iterator() {
-<
+            return new KeyIterator<K,V>(map);
-<
+        }
-<
+        final Iterator<?> iter() {
-<
+            return new KeyIterator<K,V>(map);
-<
+        }
-<
+        public final boolean add(K e) {
-<
+            throw new UnsupportedOperationException();
->
+    /**
->
+     * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in
->
+     * which additions may optionally be enabled by mapping to a
->
+     * common value.  This class cannot be directly instantiated. See
->
+     * {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
->
+     * {@link #newKeySet(int)}.
->
+     */
->
+    public static class KeySetView<K,V> extends CHMView<K,V> implements Set<K>, java.io.Serializable {
->
+        private static final long serialVersionUID = 7249069246763182397L;
->
+        private final V value;
->
+        KeySetView(ConcurrentHashMapV8<K, V> map, V value) {  // non-public
->
+            super(map);
->
+            this.value = value;
-<
+        public final boolean addAll(Collection<? extends K> c) {
-<
+            throw new UnsupportedOperationException();
->
->
+        /**
->
+         * Returns the default mapped value for additions,
->
+         * or {@code null} if additions are not supported.
->
+         *
->
+         * @return the default mapped value for additions, or {@code null}
->
+         * if not supported.
->
+         */
->
+        public V getMappedValue() { return value; }
->
->
+        // implement Set API
->
->
+        public boolean contains(Object o) { return map.containsKey(o); }
->
+        public boolean remove(Object o)   { return map.remove(o) != null; }
->
->
+        /**
->
+         * Returns a "weakly consistent" iterator that will never
->
+         * throw {@link ConcurrentModificationException}, and
->
+         * guarantees to traverse elements as they existed upon
->
+         * construction of the iterator, and may (but is not
->
+         * guaranteed to) reflect any modifications subsequent to
->
+         * construction.
->
+         *
->
+         * @return an iterator over the keys of this map
->
+         */
->
+        public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
->
+        public boolean add(K e) {
->
+            V v;
->
+            if ((v = value) == null)
->
+                throw new UnsupportedOperationException();
->
+            if (e == null)
->
+                throw new NullPointerException();
->
+            return map.internalPutIfAbsent(e, v) == null;
->
+        }
->
+        public boolean addAll(Collection<? extends K> c) {
->
+            boolean added = false;
->
+            V v;
->
+            if ((v = value) == null)
->
+                throw new UnsupportedOperationException();
->
+            for (K e : c) {
->
+                if (e == null)
->
+                    throw new NullPointerException();
->
+                if (map.internalPutIfAbsent(e, v) == null)
->
+                    added = true;
->
+            }
->
+            return added;
+        public boolean equals(Object o) {
+            Set<?> c;
+                    ((c = (Set<?>)o) == this ||
+                     (containsAll(c) && c.containsAll(this))));
-+
-+
+        /**
-+
+         * Performs the given action for each key.
-+
+         *
-+
+         * @param action the action
-+
+         */
-+
+        public void forEach(Action<K> action) {
-+
+            ForkJoinTasks.forEachKey
-+
+                (map, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Performs the given action for each non-null transformation
-+
+         * of each key.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element, or null of there is no transformation (in
-+
+         * which case the action is not applied).
-+
+         * @param action the action
-+
+         */
-+
+        public <U> void forEach(Fun<? super K, ? extends U> transformer,
-+
+                                Action<U> action) {
-+
+            ForkJoinTasks.forEachKey
-+
+                (map, transformer, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns a non-null result from applying the given search
-+
+         * function on each key, or null if none. Upon success,
-+
+         * further element processing is suppressed and the results of
-+
+         * any other parallel invocations of the search function are
-+
+         * ignored.
-+
+         *
-+
+         * @param searchFunction a function returning a non-null
-+
+         * result on success, else null
-+
+         * @return a non-null result from applying the given search
-+
+         * function on each key, or null if none
-+
+         */
-+
+        public <U> U search(Fun<? super K, ? extends U> searchFunction) {
-+
+            return ForkJoinTasks.searchKeys
-+
+                (map, searchFunction).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating all keys using the given
-+
+         * reducer to combine values, or null if none.
-+
+         *
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating all keys using the given
-+
+         * reducer to combine values, or null if none
-+
+         */
-+
+        public K reduce(BiFun<? super K, ? super K, ? extends K> reducer) {
-+
+            return ForkJoinTasks.reduceKeys
-+
+                (map, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all keys using the given reducer to combine values, and
-+
+         * the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return  the result of accumulating the given transformation
-+
+         * of all keys
-+
+         */
-+
+        public double reduceToDouble(ObjectToDouble<? super K> transformer,
-+
+                                     double basis,
-+
+                                     DoubleByDoubleToDouble reducer) {
-+
+            return ForkJoinTasks.reduceKeysToDouble
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all keys using the given reducer to combine values, and
-+
+         * the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all keys
-+
+         */
-+
+        public long reduceToLong(ObjectToLong<? super K> transformer,
-+
+                                 long basis,
-+
+                                 LongByLongToLong reducer) {
-+
+            return ForkJoinTasks.reduceKeysToLong
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all keys using the given reducer to combine values, and
-+
+         * the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all keys
-+
+         */
-+
+        public int reduceToInt(ObjectToInt<? super K> transformer,
-+
+                               int basis,
-+
+                               IntByIntToInt reducer) {
-+
+            return ForkJoinTasks.reduceKeysToInt
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-<
+    static final class Values<K,V> extends MapView<K,V>
-<
+        implements Collection<V>  {
-<
+        Values(ConcurrentHashMapV8<K, V> map)   { super(map); }
->
+    /**
->
+     * A view of a ConcurrentHashMapV8 as a {@link Collection} of
->
+     * values, in which additions are disabled. This class cannot be
->
+     * directly instantiated. See {@link #values},
->
+     *
->
+     * <p>The view's {@code iterator} is a "weakly consistent" iterator
->
+     * that will never throw {@link ConcurrentModificationException},
->
+     * and guarantees to traverse elements as they existed upon
->
+     * construction of the iterator, and may (but is not guaranteed to)
->
+     * reflect any modifications subsequent to construction.
->
+     */
->
+    public static final class ValuesView<K,V> extends CHMView<K,V>
->
+        implements Collection<V> {
->
+        ValuesView(ConcurrentHashMapV8<K, V> map)   { super(map); }
+        public final boolean contains(Object o) { return map.containsValue(o); }
-–
+        public final boolean remove(Object o) {
+            if (o != null) {
+                Iterator<V> it = new ValueIterator<K,V>(map);
+            return false;
-+
-+
+        /**
-+
+         * Returns a "weakly consistent" iterator that will never
-+
+         * throw {@link ConcurrentModificationException}, and
-+
+         * guarantees to traverse elements as they existed upon
-+
+         * construction of the iterator, and may (but is not
-+
+         * guaranteed to) reflect any modifications subsequent to
-+
+         * construction.
-+
+         *
-+
+         * @return an iterator over the values of this map
-+
+         */
+        public final Iterator<V> iterator() {
+            return new ValueIterator<K,V>(map);
-–
+        final Iterator<?> iter() {
-–
+            return new ValueIterator<K,V>(map);
-–
+        }
+        public final boolean add(V e) {
+            throw new UnsupportedOperationException();
+        public final boolean addAll(Collection<? extends V> c) {
+            throw new UnsupportedOperationException();
-+
-+
+        /**
-+
+         * Performs the given action for each value.
-+
+         *
-+
+         * @param action the action
-+
+         */
-+
+        public void forEach(Action<V> action) {
-+
+            ForkJoinTasks.forEachValue
-+
+                (map, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Performs the given action for each non-null transformation
-+
+         * of each value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element, or null of there is no transformation (in
-+
+         * which case the action is not applied).
-+
+         */
-+
+        public <U> void forEach(Fun<? super V, ? extends U> transformer,
-+
+                                     Action<U> action) {
-+
+            ForkJoinTasks.forEachValue
-+
+                (map, transformer, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns a non-null result from applying the given search
-+
+         * function on each value, or null if none.  Upon success,
-+
+         * further element processing is suppressed and the results of
-+
+         * any other parallel invocations of the search function are
-+
+         * ignored.
-+
+         *
-+
+         * @param searchFunction a function returning a non-null
-+
+         * result on success, else null
-+
+         * @return a non-null result from applying the given search
-+
+         * function on each value, or null if none
-+
+         *
-+
+         */
-+
+        public <U> U search(Fun<? super V, ? extends U> searchFunction) {
-+
+            return ForkJoinTasks.searchValues
-+
+                (map, searchFunction).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating all values using the
-+
+         * given reducer to combine values, or null if none.
-+
+         *
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return  the result of accumulating all values
-+
+         */
-+
+        public V reduce(BiFun<? super V, ? super V, ? extends V> reducer) {
-+
+            return ForkJoinTasks.reduceValues
-+
+                (map, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all values using the given reducer to combine values, or
-+
+         * null if none.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element, or null of there is no transformation (in
-+
+         * which case it is not combined).
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all values
-+
+         */
-+
+        public <U> U reduce(Fun<? super V, ? extends U> transformer,
-+
+                            BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+            return ForkJoinTasks.reduceValues
-+
+                (map, transformer, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all values using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all values
-+
+         */
-+
+        public double reduceToDouble(ObjectToDouble<? super V> transformer,
-+
+                                     double basis,
-+
+                                     DoubleByDoubleToDouble reducer) {
-+
+            return ForkJoinTasks.reduceValuesToDouble
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all values using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all values
-+
+         */
-+
+        public long reduceToLong(ObjectToLong<? super V> transformer,
-+
+                                 long basis,
-+
+                                 LongByLongToLong reducer) {
-+
+            return ForkJoinTasks.reduceValuesToLong
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all values using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all values
-+
+         */
-+
+        public int reduceToInt(ObjectToInt<? super V> transformer,
-+
+                               int basis,
-+
+                               IntByIntToInt reducer) {
-+
+            return ForkJoinTasks.reduceValuesToInt
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-<
+    static final class EntrySet<K,V>  extends MapView<K,V>
->
+    /**
->
+     * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value)
->
+     * entries.  This class cannot be directly instantiated. See
->
+     * {@link #entrySet}.
->
+     */
->
+    public static final class EntrySetView<K,V> extends CHMView<K,V>
+        implements Set<Map.Entry<K,V>> {
-<
+        EntrySet(ConcurrentHashMapV8<K, V> map) { super(map); }
-<
->
+        EntrySetView(ConcurrentHashMapV8<K, V> map) { super(map); }
+        public final boolean contains(Object o) {
+            Object k, v, r; Map.Entry<?,?> e;
+            return ((o instanceof Map.Entry) &&
+                    (v = e.getValue()) != null &&
+                    (v == r || v.equals(r)));
-–
+        public final boolean remove(Object o) {
+            Object k, v; Map.Entry<?,?> e;
+            return ((o instanceof Map.Entry) &&
+                    map.remove(k, v));
-+
+        /**
-+
+         * Returns a "weakly consistent" iterator that will never
-+
+         * throw {@link ConcurrentModificationException}, and
-+
+         * guarantees to traverse elements as they existed upon
-+
+         * construction of the iterator, and may (but is not
-+
+         * guaranteed to) reflect any modifications subsequent to
-+
+         * construction.
-+
+         *
-+
+         * @return an iterator over the entries of this map
-+
+         */
+        public final Iterator<Map.Entry<K,V>> iterator() {
+            return new EntryIterator<K,V>(map);
-<
+        final Iterator<?> iter() {
-<
+            return new SnapshotEntryIterator<K,V>(map);
-<
+        }
->
+        public final boolean add(Entry<K,V> e) {
-<
+            throw new UnsupportedOperationException();
->
+            K key = e.getKey();
->
+            V value = e.getValue();
->
+            if (key == null || value == null)
->
+                throw new NullPointerException();
->
+            return map.internalPut(key, value) == null;
+        public final boolean addAll(Collection<? extends Entry<K,V>> c) {
-<
+            throw new UnsupportedOperationException();
->
+            boolean added = false;
->
+            for (Entry<K,V> e : c) {
->
+                if (add(e))
->
+                    added = true;
->
+            }
->
+            return added;
+        public boolean equals(Object o) {
+            Set<?> c;
+                    ((c = (Set<?>)o) == this ||
+                     (containsAll(c) && c.containsAll(this))));
-+
-+
+        /**
-+
+         * Performs the given action for each entry.
-+
+         *
-+
+         * @param action the action
-+
+         */
-+
+        public void forEach(Action<Map.Entry<K,V>> action) {
-+
+            ForkJoinTasks.forEachEntry
-+
+                (map, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Performs the given action for each non-null transformation
-+
+         * of each entry.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element, or null of there is no transformation (in
-+
+         * which case the action is not applied).
-+
+         * @param action the action
-+
+         */
-+
+        public <U> void forEach(Fun<Map.Entry<K,V>, ? extends U> transformer,
-+
+                                Action<U> action) {
-+
+            ForkJoinTasks.forEachEntry
-+
+                (map, transformer, action).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns a non-null result from applying the given search
-+
+         * function on each entry, or null if none.  Upon success,
-+
+         * further element processing is suppressed and the results of
-+
+         * any other parallel invocations of the search function are
-+
+         * ignored.
-+
+         *
-+
+         * @param searchFunction a function returning a non-null
-+
+         * result on success, else null
-+
+         * @return a non-null result from applying the given search
-+
+         * function on each entry, or null if none
-+
+         */
-+
+        public <U> U search(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
-+
+            return ForkJoinTasks.searchEntries
-+
+                (map, searchFunction).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating all entries using the
-+
+         * given reducer to combine values, or null if none.
-+
+         *
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating all entries
-+
+         */
-+
+        public Map.Entry<K,V> reduce(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
-+
+            return ForkJoinTasks.reduceEntries
-+
+                (map, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all entries using the given reducer to combine values,
-+
+         * or null if none.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element, or null of there is no transformation (in
-+
+         * which case it is not combined).
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all entries
-+
+         */
-+
+        public <U> U reduce(Fun<Map.Entry<K,V>, ? extends U> transformer,
-+
+                            BiFun<? super U, ? super U, ? extends U> reducer) {
-+
+            return ForkJoinTasks.reduceEntries
-+
+                (map, transformer, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all entries using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all entries
-+
+         */
-+
+        public double reduceToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
-+
+                                     double basis,
-+
+                                     DoubleByDoubleToDouble reducer) {
-+
+            return ForkJoinTasks.reduceEntriesToDouble
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all entries using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return  the result of accumulating the given transformation
-+
+         * of all entries
-+
+         */
-+
+        public long reduceToLong(ObjectToLong<Map.Entry<K,V>> transformer,
-+
+                                 long basis,
-+
+                                 LongByLongToLong reducer) {
-+
+            return ForkJoinTasks.reduceEntriesToLong
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-+
+        /**
-+
+         * Returns the result of accumulating the given transformation
-+
+         * of all entries using the given reducer to combine values,
-+
+         * and the given basis as an identity value.
-+
+         *
-+
+         * @param transformer a function returning the transformation
-+
+         * for an element
-+
+         * @param basis the identity (initial default value) for the reduction
-+
+         * @param reducer a commutative associative combining function
-+
+         * @return the result of accumulating the given transformation
-+
+         * of all entries
-+
+         */
-+
+        public int reduceToInt(ObjectToInt<Map.Entry<K,V>> transformer,
-+
+                               int basis,
-+
+                               IntByIntToInt reducer) {
-+
+            return ForkJoinTasks.reduceEntriesToInt
-+
+                (map, transformer, basis, reducer).invoke();
-+
+        }
-+
-<
+    /* ---------------- Serialization Support -------------- */
->
+    // ---------------------------------------------------------------------
+    /**
-<
+     * Stripped-down version of helper class used in previous version,
-<
+     * declared for the sake of serialization compatibility
->
+     * Predefined tasks for performing bulk parallel operations on
->
+     * ConcurrentHashMapV8s. These tasks follow the forms and rules used
->
+     * for bulk operations. Each method has the same name, but returns
->
+     * a task rather than invoking it. These methods may be useful in
->
+     * custom applications such as submitting a task without waiting
->
+     * for completion, using a custom pool, or combining with other
->
+     * tasks.
+     */
-<
+    static class Segment<K,V> implements Serializable {
-<
+        private static final long serialVersionUID = 2249069246763182397L;
-<
+        final float loadFactor;
-<
+        Segment(float lf) { this.loadFactor = lf; }
->
+    public static class ForkJoinTasks {
->
+        private ForkJoinTasks() {}
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given
->
+         * action for each (key, value)
->
+         *
->
+         * @param map the map
->
+         * @param action the action
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Void> forEach
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiAction<K,V> action) {
->
+            if (action == null) throw new NullPointerException();
->
+            return new ForEachMappingTask<K,V>(map, null, -1, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given
->
+         * action for each non-null transformation of each (key, value)
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case the action is not applied)
->
+         * @param action the action
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<Void> forEach
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<? super K, ? super V, ? extends U> transformer,
->
+             Action<U> action) {
->
+            if (transformer == null || action == null)
->
+                throw new NullPointerException();
->
+            return new ForEachTransformedMappingTask<K,V,U>
->
+                (map, null, -1, transformer, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns a non-null result
->
+         * from applying the given search function on each (key,
->
+         * value), or null if none. Upon success, further element
->
+         * processing is suppressed and the results of any other
->
+         * parallel invocations of the search function are ignored.
->
+         *
->
+         * @param map the map
->
+         * @param searchFunction a function returning a non-null
->
+         * result on success, else null
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> search
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<? super K, ? super V, ? extends U> searchFunction) {
->
+            if (searchFunction == null) throw new NullPointerException();
->
+            return new SearchMappingsTask<K,V,U>
->
+                (map, null, -1, searchFunction,
->
+                 new AtomicReference<U>());
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all (key, value) pairs
->
+         * using the given reducer to combine values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case it is not combined).
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> reduce
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<? super K, ? super V, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceMappingsTask<K,V,U>
->
+                (map, null, -1, null, transformer, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all (key, value) pairs
->
+         * using the given reducer to combine values, and the given
->
+         * basis as an identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Double> reduceToDouble
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectByObjectToDouble<? super K, ? super V> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceMappingsToDoubleTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all (key, value) pairs
->
+         * using the given reducer to combine values, and the given
->
+         * basis as an identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Long> reduceToLong
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectByObjectToLong<? super K, ? super V> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceMappingsToLongTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all (key, value) pairs
->
+         * using the given reducer to combine values, and the given
->
+         * basis as an identity value.
->
+         *
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Integer> reduceToInt
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectByObjectToInt<? super K, ? super V> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceMappingsToIntTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given action
->
+         * for each key.
->
+         *
->
+         * @param map the map
->
+         * @param action the action
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Void> forEachKey
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Action<K> action) {
->
+            if (action == null) throw new NullPointerException();
->
+            return new ForEachKeyTask<K,V>(map, null, -1, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given action
->
+         * for each non-null transformation of each key.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case the action is not applied)
->
+         * @param action the action
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<Void> forEachKey
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super K, ? extends U> transformer,
->
+             Action<U> action) {
->
+            if (transformer == null || action == null)
->
+                throw new NullPointerException();
->
+            return new ForEachTransformedKeyTask<K,V,U>
->
+                (map, null, -1, transformer, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns a non-null result
->
+         * from applying the given search function on each key, or
->
+         * null if none.  Upon success, further element processing is
->
+         * suppressed and the results of any other parallel
->
+         * invocations of the search function are ignored.
->
+         *
->
+         * @param map the map
->
+         * @param searchFunction a function returning a non-null
->
+         * result on success, else null
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> searchKeys
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super K, ? extends U> searchFunction) {
->
+            if (searchFunction == null) throw new NullPointerException();
->
+            return new SearchKeysTask<K,V,U>
->
+                (map, null, -1, searchFunction,
->
+                 new AtomicReference<U>());
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating all keys using the given reducer to combine
->
+         * values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<K> reduceKeys
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<? super K, ? super K, ? extends K> reducer) {
->
+            if (reducer == null) throw new NullPointerException();
->
+            return new ReduceKeysTask<K,V>
->
+                (map, null, -1, null, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all keys using the given
->
+         * reducer to combine values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case it is not combined).
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> reduceKeys
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super K, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceKeysTask<K,V,U>
->
+                (map, null, -1, null, transformer, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all keys using the given
->
+         * reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToDouble<? super K> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceKeysToDoubleTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all keys using the given
->
+         * reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Long> reduceKeysToLong
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToLong<? super K> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceKeysToLongTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all keys using the given
->
+         * reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToInt<? super K> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceKeysToIntTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given action
->
+         * for each value.
->
+         *
->
+         * @param map the map
->
+         * @param action the action
->
+         */
->
+        public static <K,V> ForkJoinTask<Void> forEachValue
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Action<V> action) {
->
+            if (action == null) throw new NullPointerException();
->
+            return new ForEachValueTask<K,V>(map, null, -1, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, performs the given action
->
+         * for each non-null transformation of each value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case the action is not applied)
->
+         * @param action the action
->
+         */
->
+        public static <K,V,U> ForkJoinTask<Void> forEachValue
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super V, ? extends U> transformer,
->
+             Action<U> action) {
->
+            if (transformer == null || action == null)
->
+                throw new NullPointerException();
->
+            return new ForEachTransformedValueTask<K,V,U>
->
+                (map, null, -1, transformer, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns a non-null result
->
+         * from applying the given search function on each value, or
->
+         * null if none.  Upon success, further element processing is
->
+         * suppressed and the results of any other parallel
->
+         * invocations of the search function are ignored.
->
+         *
->
+         * @param map the map
->
+         * @param searchFunction a function returning a non-null
->
+         * result on success, else null
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> searchValues
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super V, ? extends U> searchFunction) {
->
+            if (searchFunction == null) throw new NullPointerException();
->
+            return new SearchValuesTask<K,V,U>
->
+                (map, null, -1, searchFunction,
->
+                 new AtomicReference<U>());
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating all values using the given reducer to combine
->
+         * values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<V> reduceValues
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<? super V, ? super V, ? extends V> reducer) {
->
+            if (reducer == null) throw new NullPointerException();
->
+            return new ReduceValuesTask<K,V>
->
+                (map, null, -1, null, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all values using the
->
+         * given reducer to combine values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case it is not combined).
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> reduceValues
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<? super V, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceValuesTask<K,V,U>
->
+                (map, null, -1, null, transformer, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all values using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToDouble<? super V> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceValuesToDoubleTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all values using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Long> reduceValuesToLong
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToLong<? super V> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceValuesToLongTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all values using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToInt<? super V> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceValuesToIntTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, perform the given action
->
+         * for each entry.
->
+         *
->
+         * @param map the map
->
+         * @param action the action
->
+         */
->
+        public static <K,V> ForkJoinTask<Void> forEachEntry
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Action<Map.Entry<K,V>> action) {
->
+            if (action == null) throw new NullPointerException();
->
+            return new ForEachEntryTask<K,V>(map, null, -1, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, perform the given action
->
+         * for each non-null transformation of each entry.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case the action is not applied)
->
+         * @param action the action
->
+         */
->
+        public static <K,V,U> ForkJoinTask<Void> forEachEntry
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<Map.Entry<K,V>, ? extends U> transformer,
->
+             Action<U> action) {
->
+            if (transformer == null || action == null)
->
+                throw new NullPointerException();
->
+            return new ForEachTransformedEntryTask<K,V,U>
->
+                (map, null, -1, transformer, action);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns a non-null result
->
+         * from applying the given search function on each entry, or
->
+         * null if none.  Upon success, further element processing is
->
+         * suppressed and the results of any other parallel
->
+         * invocations of the search function are ignored.
->
+         *
->
+         * @param map the map
->
+         * @param searchFunction a function returning a non-null
->
+         * result on success, else null
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> searchEntries
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
->
+            if (searchFunction == null) throw new NullPointerException();
->
+            return new SearchEntriesTask<K,V,U>
->
+                (map, null, -1, searchFunction,
->
+                 new AtomicReference<U>());
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating all entries using the given reducer to combine
->
+         * values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
->
+            if (reducer == null) throw new NullPointerException();
->
+            return new ReduceEntriesTask<K,V>
->
+                (map, null, -1, null, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all entries using the
->
+         * given reducer to combine values, or null if none.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element, or null if there is no transformation (in
->
+         * which case it is not combined).
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V,U> ForkJoinTask<U> reduceEntries
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             Fun<Map.Entry<K,V>, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceEntriesTask<K,V,U>
->
+                (map, null, -1, null, transformer, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all entries using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToDouble<Map.Entry<K,V>> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceEntriesToDoubleTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all entries using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToLong<Map.Entry<K,V>> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceEntriesToLongTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
->
->
+        /**
->
+         * Returns a task that when invoked, returns the result of
->
+         * accumulating the given transformation of all entries using the
->
+         * given reducer to combine values, and the given basis as an
->
+         * identity value.
->
+         *
->
+         * @param map the map
->
+         * @param transformer a function returning the transformation
->
+         * for an element
->
+         * @param basis the identity (initial default value) for the reduction
->
+         * @param reducer a commutative associative combining function
->
+         * @return the task
->
+         */
->
+        public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
->
+            (ConcurrentHashMapV8<K,V> map,
->
+             ObjectToInt<Map.Entry<K,V>> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            return new MapReduceEntriesToIntTask<K,V>
->
+                (map, null, -1, null, transformer, basis, reducer);
->
+        }
-<
+    /**
-<
+     * Saves the state of the {@code ConcurrentHashMapV8} instance to a
-<
+     * stream (i.e., serializes it).
-<
+     * @param s the stream
-<
+     * @serialData
-<
+     * the key (Object) and value (Object)
-<
+     * for each key-value mapping, followed by a null pair.
-<
+     * The key-value mappings are emitted in no particular order.
-<
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    private void writeObject(java.io.ObjectOutputStream s)
-<
+            throws java.io.IOException {
-<
+        if (segments == null) { // for serialization compatibility
-<
+            segments = (Segment<K,V>[])
-<
+                new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
-<
+            for (int i = 0; i < segments.length; ++i)
-<
+                segments[i] = new Segment<K,V>(LOAD_FACTOR);
->
+    // -------------------------------------------------------
->
->
+    /*
->
+     * Task classes. Coded in a regular but ugly format/style to
->
+     * simplify checks that each variant differs in the right way from
->
+     * others.
->
+     */
->
->
+    @SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
->
+        extends Traverser<K,V,Void> {
->
+        final Action<K> action;
->
+        ForEachKeyTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Action<K> action) {
->
+            super(m, p, b);
->
+            this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Action<K> action;
->
+            if ((action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachKeyTask<K,V>(map, this, b, action).fork();
->
+            while (advance() != null)
->
+                action.apply((K)nextKey);
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachValueTask<K,V>
->
+        extends Traverser<K,V,Void> {
->
+        final Action<V> action;
->
+        ForEachValueTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Action<V> action) {
->
+            super(m, p, b);
->
+            this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Action<V> action;
->
+            if ((action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachValueTask<K,V>(map, this, b, action).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                action.apply((V)v);
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
->
+        extends Traverser<K,V,Void> {
->
+        final Action<Entry<K,V>> action;
->
+        ForEachEntryTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Action<Entry<K,V>> action) {
->
+            super(m, p, b);
->
+            this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Action<Entry<K,V>> action;
->
+            if ((action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachEntryTask<K,V>(map, this, b, action).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                action.apply(entryFor((K)nextKey, (V)v));
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
->
+        extends Traverser<K,V,Void> {
->
+        final BiAction<K,V> action;
->
+        ForEachMappingTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             BiAction<K,V> action) {
->
+            super(m, p, b);
->
+            this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiAction<K,V> action;
->
+            if ((action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachMappingTask<K,V>(map, this, b, action).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                action.apply((K)nextKey, (V)v);
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
->
+        extends Traverser<K,V,Void> {
->
+        final Fun<? super K, ? extends U> transformer;
->
+        final Action<U> action;
->
+        ForEachTransformedKeyTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<? super K, ? extends U> transformer, Action<U> action) {
->
+            super(m, p, b);
->
+            this.transformer = transformer; this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super K, ? extends U> transformer;
->
+            final Action<U> action;
->
+            if ((transformer = this.transformer) == null ||
->
+                (action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachTransformedKeyTask<K,V,U>
->
+                     (map, this, b, transformer, action).fork();
->
+            U u;
->
+            while (advance() != null) {
->
+                if ((u = transformer.apply((K)nextKey)) != null)
->
+                    action.apply(u);
->
+            }
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
->
+        extends Traverser<K,V,Void> {
->
+        final Fun<? super V, ? extends U> transformer;
->
+        final Action<U> action;
->
+        ForEachTransformedValueTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<? super V, ? extends U> transformer, Action<U> action) {
->
+            super(m, p, b);
->
+            this.transformer = transformer; this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super V, ? extends U> transformer;
->
+            final Action<U> action;
->
+            if ((transformer = this.transformer) == null ||
->
+                (action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachTransformedValueTask<K,V,U>
->
+                    (map, this, b, transformer, action).fork();
->
+            Object v; U u;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply((V)v)) != null)
->
+                    action.apply(u);
->
+            }
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
->
+        extends Traverser<K,V,Void> {
->
+        final Fun<Map.Entry<K,V>, ? extends U> transformer;
->
+        final Action<U> action;
->
+        ForEachTransformedEntryTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<Map.Entry<K,V>, ? extends U> transformer, Action<U> action) {
->
+            super(m, p, b);
->
+            this.transformer = transformer; this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<Map.Entry<K,V>, ? extends U> transformer;
->
+            final Action<U> action;
->
+            if ((transformer = this.transformer) == null ||
->
+                (action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachTransformedEntryTask<K,V,U>
->
+                    (map, this, b, transformer, action).fork();
->
+            Object v; U u;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
->
+                    action.apply(u);
->
+            }
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
->
+        extends Traverser<K,V,Void> {
->
+        final BiFun<? super K, ? super V, ? extends U> transformer;
->
+        final Action<U> action;
->
+        ForEachTransformedMappingTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             BiFun<? super K, ? super V, ? extends U> transformer,
->
+             Action<U> action) {
->
+            super(m, p, b);
->
+            this.transformer = transformer; this.action = action;
->
+        }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<? super K, ? super V, ? extends U> transformer;
->
+            final Action<U> action;
->
+            if ((transformer = this.transformer) == null ||
->
+                (action = this.action) == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                new ForEachTransformedMappingTask<K,V,U>
->
+                    (map, this, b, transformer, action).fork();
->
+            Object v; U u;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply((K)nextKey, (V)v)) != null)
->
+                    action.apply(u);
->
+            }
->
+            propagateCompletion();
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<? super K, ? extends U> searchFunction;
->
+        final AtomicReference<U> result;
->
+        SearchKeysTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<? super K, ? extends U> searchFunction,
->
+             AtomicReference<U> result) {
->
+            super(m, p, b);
->
+            this.searchFunction = searchFunction; this.result = result;
->
+        }
->
+        public final U getRawResult() { return result.get(); }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super K, ? extends U> searchFunction;
->
+            final AtomicReference<U> result;
->
+            if ((searchFunction = this.searchFunction) == null ||
->
+                (result = this.result) == null)
->
+                throw new NullPointerException();
->
+            for (int b;;) {
->
+                if (result.get() != null)
->
+                    return;
->
+                if ((b = preSplit()) <= 0)
->
+                    break;
->
+                new SearchKeysTask<K,V,U>
->
+                    (map, this, b, searchFunction, result).fork();
->
+            }
->
+            while (result.get() == null) {
->
+                U u;
->
+                if (advance() == null) {
->
+                    propagateCompletion();
->
+                    break;
->
+                }
->
+                if ((u = searchFunction.apply((K)nextKey)) != null) {
->
+                    if (result.compareAndSet(null, u))
->
+                        quietlyCompleteRoot();
->
+                    break;
->
+                }
->
+            }
-<
+        s.defaultWriteObject();
-<
+        InternalIterator it = new InternalIterator(table);
-<
+        while (it.next != null) {
-<
+            s.writeObject(it.nextKey);
-<
+            s.writeObject(it.nextVal);
-<
+            it.advance();
->
+    }
->
->
+    @SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<? super V, ? extends U> searchFunction;
->
+        final AtomicReference<U> result;
->
+        SearchValuesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<? super V, ? extends U> searchFunction,
->
+             AtomicReference<U> result) {
->
+            super(m, p, b);
->
+            this.searchFunction = searchFunction; this.result = result;
->
+        }
->
+        public final U getRawResult() { return result.get(); }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super V, ? extends U> searchFunction;
->
+            final AtomicReference<U> result;
->
+            if ((searchFunction = this.searchFunction) == null ||
->
+                (result = this.result) == null)
->
+                throw new NullPointerException();
->
+            for (int b;;) {
->
+                if (result.get() != null)
->
+                    return;
->
+                if ((b = preSplit()) <= 0)
->
+                    break;
->
+                new SearchValuesTask<K,V,U>
->
+                    (map, this, b, searchFunction, result).fork();
->
+            }
->
+            while (result.get() == null) {
->
+                Object v; U u;
->
+                if ((v = advance()) == null) {
->
+                    propagateCompletion();
->
+                    break;
->
+                }
->
+                if ((u = searchFunction.apply((V)v)) != null) {
->
+                    if (result.compareAndSet(null, u))
->
+                        quietlyCompleteRoot();
->
+                    break;
->
+                }
->
+            }
-–
+        s.writeObject(null);
-–
+        s.writeObject(null);
-–
+        segments = null; // throw away
-<
+    /**
-<
+     * Reconstitutes the instance from a stream (that is, deserializes it).
-<
+     * @param s the stream
-<
+     */
-<
+    @SuppressWarnings("unchecked")
-<
+    private void readObject(java.io.ObjectInputStream s)
-<
+            throws java.io.IOException, ClassNotFoundException {
-<
+        s.defaultReadObject();
-<
+        this.segments = null; // unneeded
-<
+        // initialize transient final field
-<
+        UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
->
+    @SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<Entry<K,V>, ? extends U> searchFunction;
->
+        final AtomicReference<U> result;
->
+        SearchEntriesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             Fun<Entry<K,V>, ? extends U> searchFunction,
->
+             AtomicReference<U> result) {
->
+            super(m, p, b);
->
+            this.searchFunction = searchFunction; this.result = result;
->
+        }
->
+        public final U getRawResult() { return result.get(); }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<Entry<K,V>, ? extends U> searchFunction;
->
+            final AtomicReference<U> result;
->
+            if ((searchFunction = this.searchFunction) == null ||
->
+                (result = this.result) == null)
->
+                throw new NullPointerException();
->
+            for (int b;;) {
->
+                if (result.get() != null)
->
+                    return;
->
+                if ((b = preSplit()) <= 0)
->
+                    break;
->
+                new SearchEntriesTask<K,V,U>
->
+                    (map, this, b, searchFunction, result).fork();
->
+            }
->
+            while (result.get() == null) {
->
+                Object v; U u;
->
+                if ((v = advance()) == null) {
->
+                    propagateCompletion();
->
+                    break;
->
+                }
->
+                if ((u = searchFunction.apply(entryFor((K)nextKey, (V)v))) != null) {
->
+                    if (result.compareAndSet(null, u))
->
+                        quietlyCompleteRoot();
->
+                    return;
->
+                }
->
+            }
->
+        }
->
+    }
-<
+        // Create all nodes, then place in table once size is known
-<
+        long size = 0L;
-<
+        Node p = null;
-<
+        for (;;) {
-<
+            K k = (K) s.readObject();
-<
+            V v = (V) s.readObject();
-<
+            if (k != null && v != null) {
-<
+                p = new Node(spread(k.hashCode()), k, v, p);
-<
+                ++size;
->
+    @SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final BiFun<? super K, ? super V, ? extends U> searchFunction;
->
+        final AtomicReference<U> result;
->
+        SearchMappingsTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             BiFun<? super K, ? super V, ? extends U> searchFunction,
->
+             AtomicReference<U> result) {
->
+            super(m, p, b);
->
+            this.searchFunction = searchFunction; this.result = result;
->
+        }
->
+        public final U getRawResult() { return result.get(); }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<? super K, ? super V, ? extends U> searchFunction;
->
+            final AtomicReference<U> result;
->
+            if ((searchFunction = this.searchFunction) == null ||
->
+                (result = this.result) == null)
->
+                throw new NullPointerException();
->
+            for (int b;;) {
->
+                if (result.get() != null)
->
+                    return;
->
+                if ((b = preSplit()) <= 0)
->
+                    break;
->
+                new SearchMappingsTask<K,V,U>
->
+                    (map, this, b, searchFunction, result).fork();
->
+            }
->
+            while (result.get() == null) {
->
+                Object v; U u;
->
+                if ((v = advance()) == null) {
->
+                    propagateCompletion();
->
+                    break;
->
+                }
->
+                if ((u = searchFunction.apply((K)nextKey, (V)v)) != null) {
->
+                    if (result.compareAndSet(null, u))
->
+                        quietlyCompleteRoot();
->
+                    break;
->
+                }
-–
+            else
-–
+                break;
-<
+        if (p != null) {
-<
+            boolean init = false;
-<
+            int n;
-<
+            if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
-<
+                n = MAXIMUM_CAPACITY;
-<
+            else {
-<
+                int sz = (int)size;
-<
+                n = tableSizeFor(sz + (sz >>> 1) + 1);
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
->
+        extends Traverser<K,V,K> {
->
+        final BiFun<? super K, ? super K, ? extends K> reducer;
->
+        K result;
->
+        ReduceKeysTask<K,V> rights, nextRight;
->
+        ReduceKeysTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             ReduceKeysTask<K,V> nextRight,
->
+             BiFun<? super K, ? super K, ? extends K> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.reducer = reducer;
->
+        }
->
+        public final K getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<? super K, ? super K, ? extends K> reducer =
->
+                this.reducer;
->
+            if (reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new ReduceKeysTask<K,V>
->
+                 (map, this, b, rights, reducer)).fork();
->
+            K r = null;
->
+            while (advance() != null) {
->
+                K u = (K)nextKey;
->
+                r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                ReduceKeysTask<K,V>
->
+                    t = (ReduceKeysTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    K tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
-<
+            int sc = sizeCtl;
-<
+            if (n > sc &&
-<
+                UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
-<
+                try {
-<
+                    if (table == null) {
-<
+                        init = true;
-<
+                        Node[] tab = new Node[n];
-<
+                        int mask = n - 1;
-<
+                        while (p != null) {
-<
+                            int j = p.hash & mask;
-<
+                            Node next = p.next;
-<
+                            p.next = tabAt(tab, j);
-<
+                            setTabAt(tab, j, p);
-<
+                            p = next;
-<
+                        }
-<
+                        table = tab;
-<
+                        counter.add(size);
-<
+                        sc = n - (n >>> 2);
-<
+                    }
-<
+                } finally {
-<
+                    sizeCtl = sc;
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
->
+        extends Traverser<K,V,V> {
->
+        final BiFun<? super V, ? super V, ? extends V> reducer;
->
+        V result;
->
+        ReduceValuesTask<K,V> rights, nextRight;
->
+        ReduceValuesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             ReduceValuesTask<K,V> nextRight,
->
+             BiFun<? super V, ? super V, ? extends V> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.reducer = reducer;
->
+        }
->
+        public final V getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<? super V, ? super V, ? extends V> reducer =
->
+                this.reducer;
->
+            if (reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new ReduceValuesTask<K,V>
->
+                 (map, this, b, rights, reducer)).fork();
->
+            V r = null;
->
+            Object v;
->
+            while ((v = advance()) != null) {
->
+                V u = (V)v;
->
+                r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                ReduceValuesTask<K,V>
->
+                    t = (ReduceValuesTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    V tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
-<
+            if (!init) { // Can only happen if unsafely published.
-<
+                while (p != null) {
-<
+                    internalPut(p.key, p.val);
-<
+                    p = p.next;
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
->
+        extends Traverser<K,V,Map.Entry<K,V>> {
->
+        final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
->
+        Map.Entry<K,V> result;
->
+        ReduceEntriesTask<K,V> rights, nextRight;
->
+        ReduceEntriesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             ReduceEntriesTask<K,V> nextRight,
->
+             BiFun<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.reducer = reducer;
->
+        }
->
+        public final Map.Entry<K,V> getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer =
->
+                this.reducer;
->
+            if (reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new ReduceEntriesTask<K,V>
->
+                 (map, this, b, rights, reducer)).fork();
->
+            Map.Entry<K,V> r = null;
->
+            Object v;
->
+            while ((v = advance()) != null) {
->
+                Map.Entry<K,V> u = entryFor((K)nextKey, (V)v);
->
+                r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                ReduceEntriesTask<K,V>
->
+                    t = (ReduceEntriesTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    Map.Entry<K,V> tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<? super K, ? extends U> transformer;
->
+        final BiFun<? super U, ? super U, ? extends U> reducer;
->
+        U result;
->
+        MapReduceKeysTask<K,V,U> rights, nextRight;
->
+        MapReduceKeysTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceKeysTask<K,V,U> nextRight,
->
+             Fun<? super K, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.reducer = reducer;
->
+        }
->
+        public final U getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super K, ? extends U> transformer =
->
+                this.transformer;
->
+            final BiFun<? super U, ? super U, ? extends U> reducer =
->
+                this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceKeysTask<K,V,U>
->
+                 (map, this, b, rights, transformer, reducer)).fork();
->
+            U r = null, u;
->
+            while (advance() != null) {
->
+                if ((u = transformer.apply((K)nextKey)) != null)
->
+                    r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceKeysTask<K,V,U>
->
+                    t = (MapReduceKeysTask<K,V,U>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    U tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<? super V, ? extends U> transformer;
->
+        final BiFun<? super U, ? super U, ? extends U> reducer;
->
+        U result;
->
+        MapReduceValuesTask<K,V,U> rights, nextRight;
->
+        MapReduceValuesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceValuesTask<K,V,U> nextRight,
->
+             Fun<? super V, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.reducer = reducer;
->
+        }
->
+        public final U getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<? super V, ? extends U> transformer =
->
+                this.transformer;
->
+            final BiFun<? super U, ? super U, ? extends U> reducer =
->
+                this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceValuesTask<K,V,U>
->
+                 (map, this, b, rights, transformer, reducer)).fork();
->
+            U r = null, u;
->
+            Object v;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply((V)v)) != null)
->
+                    r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceValuesTask<K,V,U>
->
+                    t = (MapReduceValuesTask<K,V,U>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    U tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final Fun<Map.Entry<K,V>, ? extends U> transformer;
->
+        final BiFun<? super U, ? super U, ? extends U> reducer;
->
+        U result;
->
+        MapReduceEntriesTask<K,V,U> rights, nextRight;
->
+        MapReduceEntriesTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceEntriesTask<K,V,U> nextRight,
->
+             Fun<Map.Entry<K,V>, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.reducer = reducer;
->
+        }
->
+        public final U getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final Fun<Map.Entry<K,V>, ? extends U> transformer =
->
+                this.transformer;
->
+            final BiFun<? super U, ? super U, ? extends U> reducer =
->
+                this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceEntriesTask<K,V,U>
->
+                 (map, this, b, rights, transformer, reducer)).fork();
->
+            U r = null, u;
->
+            Object v;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
->
+                    r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceEntriesTask<K,V,U>
->
+                    t = (MapReduceEntriesTask<K,V,U>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    U tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
->
+        extends Traverser<K,V,U> {
->
+        final BiFun<? super K, ? super V, ? extends U> transformer;
->
+        final BiFun<? super U, ? super U, ? extends U> reducer;
->
+        U result;
->
+        MapReduceMappingsTask<K,V,U> rights, nextRight;
->
+        MapReduceMappingsTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceMappingsTask<K,V,U> nextRight,
->
+             BiFun<? super K, ? super V, ? extends U> transformer,
->
+             BiFun<? super U, ? super U, ? extends U> reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.reducer = reducer;
->
+        }
->
+        public final U getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final BiFun<? super K, ? super V, ? extends U> transformer =
->
+                this.transformer;
->
+            final BiFun<? super U, ? super U, ? extends U> reducer =
->
+                this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceMappingsTask<K,V,U>
->
+                 (map, this, b, rights, transformer, reducer)).fork();
->
+            U r = null, u;
->
+            Object v;
->
+            while ((v = advance()) != null) {
->
+                if ((u = transformer.apply((K)nextKey, (V)v)) != null)
->
+                    r = (r == null) ? u : reducer.apply(r, u);
->
+            }
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceMappingsTask<K,V,U>
->
+                    t = (MapReduceMappingsTask<K,V,U>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    U tr, sr;
->
+                    if ((sr = s.result) != null)
->
+                        t.result = (((tr = t.result) == null) ? sr :
->
+                                    reducer.apply(tr, sr));
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
->
+        extends Traverser<K,V,Double> {
->
+        final ObjectToDouble<? super K> transformer;
->
+        final DoubleByDoubleToDouble reducer;
->
+        final double basis;
->
+        double result;
->
+        MapReduceKeysToDoubleTask<K,V> rights, nextRight;
->
+        MapReduceKeysToDoubleTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceKeysToDoubleTask<K,V> nextRight,
->
+             ObjectToDouble<? super K> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Double getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToDouble<? super K> transformer =
->
+                this.transformer;
->
+            final DoubleByDoubleToDouble reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            double r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceKeysToDoubleTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            while (advance() != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceKeysToDoubleTask<K,V>
->
+                    t = (MapReduceKeysToDoubleTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
->
+        extends Traverser<K,V,Double> {
->
+        final ObjectToDouble<? super V> transformer;
->
+        final DoubleByDoubleToDouble reducer;
->
+        final double basis;
->
+        double result;
->
+        MapReduceValuesToDoubleTask<K,V> rights, nextRight;
->
+        MapReduceValuesToDoubleTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceValuesToDoubleTask<K,V> nextRight,
->
+             ObjectToDouble<? super V> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Double getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToDouble<? super V> transformer =
->
+                this.transformer;
->
+            final DoubleByDoubleToDouble reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            double r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceValuesToDoubleTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceValuesToDoubleTask<K,V>
->
+                    t = (MapReduceValuesToDoubleTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
->
+        extends Traverser<K,V,Double> {
->
+        final ObjectToDouble<Map.Entry<K,V>> transformer;
->
+        final DoubleByDoubleToDouble reducer;
->
+        final double basis;
->
+        double result;
->
+        MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
->
+        MapReduceEntriesToDoubleTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceEntriesToDoubleTask<K,V> nextRight,
->
+             ObjectToDouble<Map.Entry<K,V>> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Double getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToDouble<Map.Entry<K,V>> transformer =
->
+                this.transformer;
->
+            final DoubleByDoubleToDouble reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            double r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceEntriesToDoubleTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceEntriesToDoubleTask<K,V>
->
+                    t = (MapReduceEntriesToDoubleTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
->
+        extends Traverser<K,V,Double> {
->
+        final ObjectByObjectToDouble<? super K, ? super V> transformer;
->
+        final DoubleByDoubleToDouble reducer;
->
+        final double basis;
->
+        double result;
->
+        MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
->
+        MapReduceMappingsToDoubleTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceMappingsToDoubleTask<K,V> nextRight,
->
+             ObjectByObjectToDouble<? super K, ? super V> transformer,
->
+             double basis,
->
+             DoubleByDoubleToDouble reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Double getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectByObjectToDouble<? super K, ? super V> transformer =
->
+                this.transformer;
->
+            final DoubleByDoubleToDouble reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            double r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceMappingsToDoubleTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceMappingsToDoubleTask<K,V>
->
+                    t = (MapReduceMappingsToDoubleTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
->
+        extends Traverser<K,V,Long> {
->
+        final ObjectToLong<? super K> transformer;
->
+        final LongByLongToLong reducer;
->
+        final long basis;
->
+        long result;
->
+        MapReduceKeysToLongTask<K,V> rights, nextRight;
->
+        MapReduceKeysToLongTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceKeysToLongTask<K,V> nextRight,
->
+             ObjectToLong<? super K> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Long getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToLong<? super K> transformer =
->
+                this.transformer;
->
+            final LongByLongToLong reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            long r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceKeysToLongTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            while (advance() != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceKeysToLongTask<K,V>
->
+                    t = (MapReduceKeysToLongTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
->
+        extends Traverser<K,V,Long> {
->
+        final ObjectToLong<? super V> transformer;
->
+        final LongByLongToLong reducer;
->
+        final long basis;
->
+        long result;
->
+        MapReduceValuesToLongTask<K,V> rights, nextRight;
->
+        MapReduceValuesToLongTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceValuesToLongTask<K,V> nextRight,
->
+             ObjectToLong<? super V> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Long getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToLong<? super V> transformer =
->
+                this.transformer;
->
+            final LongByLongToLong reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            long r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceValuesToLongTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceValuesToLongTask<K,V>
->
+                    t = (MapReduceValuesToLongTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
->
+        extends Traverser<K,V,Long> {
->
+        final ObjectToLong<Map.Entry<K,V>> transformer;
->
+        final LongByLongToLong reducer;
->
+        final long basis;
->
+        long result;
->
+        MapReduceEntriesToLongTask<K,V> rights, nextRight;
->
+        MapReduceEntriesToLongTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceEntriesToLongTask<K,V> nextRight,
->
+             ObjectToLong<Map.Entry<K,V>> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Long getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToLong<Map.Entry<K,V>> transformer =
->
+                this.transformer;
->
+            final LongByLongToLong reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            long r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceEntriesToLongTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceEntriesToLongTask<K,V>
->
+                    t = (MapReduceEntriesToLongTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
->
+        extends Traverser<K,V,Long> {
->
+        final ObjectByObjectToLong<? super K, ? super V> transformer;
->
+        final LongByLongToLong reducer;
->
+        final long basis;
->
+        long result;
->
+        MapReduceMappingsToLongTask<K,V> rights, nextRight;
->
+        MapReduceMappingsToLongTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceMappingsToLongTask<K,V> nextRight,
->
+             ObjectByObjectToLong<? super K, ? super V> transformer,
->
+             long basis,
->
+             LongByLongToLong reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Long getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectByObjectToLong<? super K, ? super V> transformer =
->
+                this.transformer;
->
+            final LongByLongToLong reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            long r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceMappingsToLongTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceMappingsToLongTask<K,V>
->
+                    t = (MapReduceMappingsToLongTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
->
+        extends Traverser<K,V,Integer> {
->
+        final ObjectToInt<? super K> transformer;
->
+        final IntByIntToInt reducer;
->
+        final int basis;
->
+        int result;
->
+        MapReduceKeysToIntTask<K,V> rights, nextRight;
->
+        MapReduceKeysToIntTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceKeysToIntTask<K,V> nextRight,
->
+             ObjectToInt<? super K> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Integer getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToInt<? super K> transformer =
->
+                this.transformer;
->
+            final IntByIntToInt reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            int r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceKeysToIntTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            while (advance() != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceKeysToIntTask<K,V>
->
+                    t = (MapReduceKeysToIntTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
->
+        extends Traverser<K,V,Integer> {
->
+        final ObjectToInt<? super V> transformer;
->
+        final IntByIntToInt reducer;
->
+        final int basis;
->
+        int result;
->
+        MapReduceValuesToIntTask<K,V> rights, nextRight;
->
+        MapReduceValuesToIntTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceValuesToIntTask<K,V> nextRight,
->
+             ObjectToInt<? super V> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Integer getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToInt<? super V> transformer =
->
+                this.transformer;
->
+            final IntByIntToInt reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            int r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceValuesToIntTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceValuesToIntTask<K,V>
->
+                    t = (MapReduceValuesToIntTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
->
+        extends Traverser<K,V,Integer> {
->
+        final ObjectToInt<Map.Entry<K,V>> transformer;
->
+        final IntByIntToInt reducer;
->
+        final int basis;
->
+        int result;
->
+        MapReduceEntriesToIntTask<K,V> rights, nextRight;
->
+        MapReduceEntriesToIntTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceEntriesToIntTask<K,V> nextRight,
->
+             ObjectToInt<Map.Entry<K,V>> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Integer getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectToInt<Map.Entry<K,V>> transformer =
->
+                this.transformer;
->
+            final IntByIntToInt reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            int r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceEntriesToIntTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceEntriesToIntTask<K,V>
->
+                    t = (MapReduceEntriesToIntTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
->
+                }
->
+            }
->
+        }
->
+    }
->
->
+    @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
->
+        extends Traverser<K,V,Integer> {
->
+        final ObjectByObjectToInt<? super K, ? super V> transformer;
->
+        final IntByIntToInt reducer;
->
+        final int basis;
->
+        int result;
->
+        MapReduceMappingsToIntTask<K,V> rights, nextRight;
->
+        MapReduceMappingsToIntTask
->
+            (ConcurrentHashMapV8<K,V> m, Traverser<K,V,?> p, int b,
->
+             MapReduceMappingsToIntTask<K,V> nextRight,
->
+             ObjectByObjectToInt<? super K, ? super V> transformer,
->
+             int basis,
->
+             IntByIntToInt reducer) {
->
+            super(m, p, b); this.nextRight = nextRight;
->
+            this.transformer = transformer;
->
+            this.basis = basis; this.reducer = reducer;
->
+        }
->
+        public final Integer getRawResult() { return result; }
->
+        @SuppressWarnings("unchecked") public final void compute() {
->
+            final ObjectByObjectToInt<? super K, ? super V> transformer =
->
+                this.transformer;
->
+            final IntByIntToInt reducer = this.reducer;
->
+            if (transformer == null || reducer == null)
->
+                throw new NullPointerException();
->
+            int r = this.basis;
->
+            for (int b; (b = preSplit()) > 0;)
->
+                (rights = new MapReduceMappingsToIntTask<K,V>
->
+                 (map, this, b, rights, transformer, r, reducer)).fork();
->
+            Object v;
->
+            while ((v = advance()) != null)
->
+                r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
->
+            result = r;
->
+            CountedCompleter<?> c;
->
+            for (c = firstComplete(); c != null; c = c.nextComplete()) {
->
+                MapReduceMappingsToIntTask<K,V>
->
+                    t = (MapReduceMappingsToIntTask<K,V>)c,
->
+                    s = t.rights;
->
+                while (s != null) {
->
+                    t.result = reducer.apply(t.result, s.result);
->
+                    s = t.rights = s.nextRight;
-–

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents): Revision 1.31 by jsr166, Tue Oct 25 20:26:37 2011 UTC vs. Revision 1.81 by dl, Sat Dec 8 14:10:38 2012 UTC

Diff Legend

Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents):
Revision 1.31 by jsr166, Tue Oct 25 20:26:37 2011 UTC vs.
Revision 1.81 by dl, Sat Dec 8 14:10:38 2012 UTC