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+++ b/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,6398 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent;
+
+import java.io.ObjectStreamField;
+import java.io.Serializable;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.AbstractMap;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Hashtable;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.Spliterator;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.LockSupport;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.DoubleBinaryOperator;
+import java.util.function.Function;
+import java.util.function.IntBinaryOperator;
+import java.util.function.LongBinaryOperator;
+import java.util.function.Predicate;
+import java.util.function.ToDoubleBiFunction;
+import java.util.function.ToDoubleFunction;
+import java.util.function.ToIntBiFunction;
+import java.util.function.ToIntFunction;
+import java.util.function.ToLongBiFunction;
+import java.util.function.ToLongFunction;
+import java.util.stream.Stream;
+import jdk.internal.misc.Unsafe;
+
+/**
+ * A hash table supporting full concurrency of retrievals and
+ * high expected concurrency for updates. This class obeys the
+ * same functional specification as {@link java.util.Hashtable}, and
+ * includes versions of methods corresponding to each method of
+ * {@code Hashtable}. However, even though all operations are
+ * thread-safe, retrieval operations do <em>not</em> entail locking,
+ * and there is <em>not</em> any support for locking the entire table
+ * in a way that prevents all access. This class is fully
+ * 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
+ * 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. (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, Spliterators 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
+ * java.util.ConcurrentModificationException 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
+ * 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
+ * to a 0.75 load factor threshold for resizing). There may be much
+ * variance around this average as mappings are added and removed, but
+ * overall, this maintains a commonly accepted time/space tradeoff for
+ * hash tables. However, resizing this or any other kind of hash
+ * table may be a relatively slow operation. When possible, it is a
+ * good idea to provide a size estimate as an optional {@code
+ * initialCapacity} constructor argument. An additional optional
+ * {@code loadFactor} constructor argument provides a further means of
+ * customizing initial table capacity by specifying the table density
+ * to be used in calculating the amount of space to allocate for the
+ * given number of elements. Also, for compatibility with previous
+ * versions of this class, constructors may optionally specify an
+ * expected {@code concurrencyLevel} as an additional hint for
+ * internal sizing. Note that using many keys with exactly the same
+ * {@code hashCode()} is a sure way to slow down performance of any
+ * hash table. To ameliorate impact, when keys are {@link Comparable},
+ * this class may use comparison order among keys to help break ties.
+ *
+ * <p>A {@link Set} projection of a ConcurrentHashMap 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 ConcurrentHashMap can be used as a scalable frequency map (a
+ * form of histogram or multiset) by using {@link
+ * java.util.concurrent.atomic.LongAdder} values and initializing via
+ * {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
+ * to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
+ * {@code freqs.computeIfAbsent(key, 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
+ * does <em>not</em> allow {@code null} to be used as a key or value.
+ *
+ * <p>ConcurrentHashMaps support a set of sequential and parallel bulk
+ * operations that, unlike most {@link Stream} methods, 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) pairs as
+ * arguments and/or return values. Because the elements of a
+ * ConcurrentHashMap 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. Bulk operations on
+ * {@link Map.Entry} objects do not support method {@code setValue}.
+ *
+ * <ul>
+ * <li>forEach: Performs a given action on each element.
+ * A variant form applies a given transformation on each element
+ * before performing the action.
+ *
+ * <li>search: Returns the first available non-null result of
+ * applying a given function on each element; skipping further
+ * search when a result is found.
+ *
+ * <li>reduce: Accumulates 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>Mapped reductions that accumulate the results of a given
+ * function applied to each element.
+ *
+ * <li>Reductions to scalar doubles, longs, and ints, using a
+ * given basis value.
+ *
+ * </ul>
+ * </ul>
+ *
+ * <p>These bulk operations accept a {@code parallelismThreshold}
+ * argument. Methods proceed sequentially if the current map size is
+ * estimated to be less than the given threshold. Using a value of
+ * {@code Long.MAX_VALUE} suppresses all parallelism. Using a value
+ * of {@code 1} results in maximal parallelism by partitioning into
+ * enough subtasks to fully utilize the {@link
+ * ForkJoinPool#commonPool()} that is used for all parallel
+ * computations. Normally, you would initially choose one of these
+ * extreme values, and then measure performance of using in-between
+ * values that trade off overhead versus throughput.
+ *
+ * <p>The concurrency properties of bulk operations follow
+ * from those of ConcurrentHashMap: 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>Speedups for parallel compared to sequential forms are common
+ * but not guaranteed. Parallel operations involving brief functions
+ * on small maps may execute more slowly than sequential forms 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>This class is a member of the
+ * <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
+ * Java Collections Framework</a>.
+ *
+ * @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 ConcurrentHashMap<K,V> extends AbstractMap<K,V>
+ implements ConcurrentMap<K,V>, Serializable {
+ private static final long serialVersionUID = 7249069246763182397L;
+
+ /*
+ * Overview:
+ *
+ * The primary design goal of this hash table is to maintain
+ * concurrent readability (typically method get(), but also
+ * iterators and related methods) while minimizing update
+ * contention. Secondary goals are to keep space consumption about
+ * the same or better than java.util.HashMap, and to support high
+ * initial insertion rates on an empty table by many threads.
+ *
+ * This map usually acts as a binned (bucketed) hash table. Each
+ * key-value mapping is held in a Node. Most nodes are instances
+ * of the basic Node class with hash, key, value, and next
+ * fields. However, various subclasses exist: TreeNodes are
+ * arranged in balanced trees, not lists. TreeBins hold the roots
+ * of sets of TreeNodes. ForwardingNodes are placed at the heads
+ * of bins during resizing. ReservationNodes are used as
+ * placeholders while establishing values in computeIfAbsent and
+ * related methods. The types TreeBin, ForwardingNode, and
+ * ReservationNode do not hold normal user keys, values, or
+ * hashes, and are readily distinguishable during search etc
+ * because they have negative hash fields and null key and value
+ * fields. (These special nodes are either uncommon or transient,
+ * so the impact of carrying around some unused fields is
+ * insignificant.)
+ *
+ * The table is lazily initialized to a power-of-two size upon the
+ * 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
+ * (jdk.internal.misc.Unsafe) operations.
+ *
+ * We use the top (sign) bit of Node hash fields for control
+ * purposes -- it is available anyway because of addressing
+ * constraints. Nodes with negative hash fields are specially
+ * handled or ignored in map methods.
+ *
+ * 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 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. Locking support for these locks relies on builtin
+ * "synchronized" monitors.
+ *
+ * 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
+ * validate that it is still the first node after locking it, and
+ * retry if not. Because new nodes are always appended to lists,
+ * once a node is first in a bin, it remains first until deleted
+ * or the bin becomes invalidated (upon resizing).
+ *
+ * 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, 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 values are:
+ *
+ * 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) 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 or ones that differs only
+ * in masked-out high bits. So we use a secondary strategy that
+ * applies when the number of nodes in a bin exceeds a
+ * threshold. 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 at least 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 a percentage
+ * threshold (nominally, 0.75, but see below). Any thread
+ * noticing an overfull bin may assist in resizing after the
+ * initiating thread allocates and sets up the replacement array.
+ * However, rather than stalling, these other threads may proceed
+ * with insertions etc. The use of TreeBins shields us from the
+ * worst case effects of overfilling while resizes are in
+ * progress. Resizing proceeds by transferring bins, one by one,
+ * from the table to the next table. However, threads claim small
+ * blocks of indices to transfer (via field transferIndex) before
+ * doing so, reducing contention. A generation stamp in field
+ * sizeCtl ensures that resizings do not overlap. Because we are
+ * using power-of-two expansion, the elements from each bin must
+ * either stay at same index, or move with a power of two
+ * offset. We eliminate unnecessary node creation by catching
+ * cases where old nodes can be reused because their next fields
+ * won't change. On average, only about one-sixth of them need
+ * cloning when a table doubles. The nodes they replace will be
+ * garbage collectable as soon as they are no longer referenced by
+ * any reader thread that may be in the midst of concurrently
+ * traversing table. Upon transfer, the old table bin contains
+ * only a special forwarding node (with hash field "MOVED") that
+ * contains the next table as its key. On encountering a
+ * forwarding node, access and update operations restart, using
+ * the new table.
+ *
+ * Each bin transfer requires its bin lock, which can stall
+ * waiting for locks while resizing. However, because other
+ * threads can join in and help resize rather than contend for
+ * locks, average aggregate waits become shorter as resizing
+ * progresses. The transfer operation must also ensure that all
+ * accessible bins in both the old and new table are usable by any
+ * traversal. This is arranged in part by proceeding from the
+ * last bin (table.length - 1) up towards the first. Upon seeing
+ * a forwarding node, traversals (see class Traverser) arrange to
+ * move to the new table without revisiting nodes. To ensure that
+ * no intervening nodes are skipped even when moved out of order,
+ * a stack (see class TableStack) is created on first encounter of
+ * a forwarding node during a traversal, to maintain its place if
+ * later processing the current table. The need for these
+ * save/restore mechanics is relatively rare, but when one
+ * forwarding node is encountered, typically many more will be.
+ * So Traversers use a simple caching scheme to avoid creating so
+ * many new TableStack nodes. (Thanks to Peter Levart for
+ * suggesting use of a stack here.)
+ *
+ * The traversal scheme also applies to partial traversals of
+ * 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
+ * putAll, constructor with map argument, or deserialization.
+ * These cases attempt to override the initial capacity settings,
+ * but harmlessly fail to take effect in cases of races.
+ *
+ * The element count is maintained using a specialization of
+ * LongAdder. We need to incorporate a specialization rather than
+ * just use a LongAdder in order to access implicit
+ * contention-sensing that leads to creation of multiple
+ * CounterCells. The counter mechanics avoid contention on
+ * updates but can encounter cache thrashing if read too
+ * frequently during concurrent access. To avoid reading so often,
+ * resizing under contention is attempted only upon adding to a
+ * bin already holding two or more nodes. Under uniform hash
+ * distributions, the probability of this occurring at threshold
+ * is around 13%, meaning that only about 1 in 8 puts check
+ * threshold (and after resizing, many fewer do so).
+ *
+ * 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 for
+ * the same T, so we cannot invoke compareTo among them. To handle
+ * this, the tree is ordered primarily by hash value, then by
+ * Comparable.compareTo order if applicable. On lookup at a node,
+ * if elements are not comparable or compare as 0 then 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.) On insertion, to keep a total ordering (or as
+ * close as is required here) across rebalancings, we compare
+ * classes and identityHashCodes as tie-breakers. 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 require an additional locking mechanism. While
+ * list traversal is always possible by readers even during
+ * updates, tree traversal is not, mainly because of tree-rotations
+ * that may change the root node and/or its linkages. TreeBins
+ * include a simple read-write lock mechanism parasitic on the
+ * main bin-synchronization strategy: Structural adjustments
+ * associated with an insertion or removal are already bin-locked
+ * (and so cannot conflict with other writers) but must wait for
+ * ongoing readers to finish. Since there can be only one such
+ * waiter, we use a simple scheme using a single "waiter" field to
+ * block writers. However, readers need never block. If the root
+ * lock is held, 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.
+ *
+ * Maintaining API and serialization compatibility with previous
+ * versions of this class introduces several oddities. Mainly: We
+ * leave untouched but unused constructor arguments referring to
+ * concurrencyLevel. We accept a loadFactor constructor argument,
+ * but apply it only to initial table capacity (which is the only
+ * time that we can guarantee to honor it.) We also declare an
+ * unused "Segment" class that is instantiated in minimal form
+ * only when serializing.
+ *
+ * Also, solely for compatibility with previous versions of this
+ * class, it extends AbstractMap, even though all of its methods
+ * are overridden, so it is just useless baggage.
+ *
+ * This file is organized to make things a little easier to follow
+ * while reading than they might otherwise: First the main static
+ * declarations and utilities, then fields, then main public
+ * methods (with a few factorings of multiple public methods into
+ * internal ones), then sizing methods, trees, traversers, and
+ * bulk operations.
+ */
+
+ /* ---------------- Constants -------------- */
+
+ /**
+ * The largest possible table capacity. This value must be
+ * exactly 1<<30 to stay within Java array allocation and indexing
+ * bounds for power of two table sizes, and is further required
+ * because the top two bits of 32bit hash fields are used for
+ * control purposes.
+ */
+ private static final int MAXIMUM_CAPACITY = 1 << 30;
+
+ /**
+ * The default initial table capacity. Must be a power of 2
+ * (i.e., at least 1) and at most MAXIMUM_CAPACITY.
+ */
+ private static final int DEFAULT_CAPACITY = 16;
+
+ /**
+ * The largest possible (non-power of two) array size.
+ * Needed by toArray and related methods.
+ */
+ static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
+
+ /**
+ * The default concurrency level for this table. Unused but
+ * defined for compatibility with previous versions of this class.
+ */
+ private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
+
+ /**
+ * The load factor for this table. Overrides of this value in
+ * constructors affect only the initial table capacity. The
+ * actual floating point value isn't normally used -- it is
+ * simpler to use expressions such as {@code n - (n >>> 2)} for
+ * the associated resizing threshold.
+ */
+ private static final float LOAD_FACTOR = 0.75f;
+
+ /**
+ * The bin count threshold for using a tree rather than list for a
+ * bin. Bins are converted to trees when adding an element to a
+ * bin with at least this many nodes. The value must be greater
+ * than 2, and should be at least 8 to mesh with assumptions in
+ * tree removal about conversion back to plain bins upon
+ * shrinkage.
+ */
+ static final int TREEIFY_THRESHOLD = 8;
+
+ /**
+ * The bin count threshold for untreeifying a (split) bin during a
+ * resize operation. Should be less than TREEIFY_THRESHOLD, and at
+ * most 6 to mesh with shrinkage detection under removal.
+ */
+ static final int UNTREEIFY_THRESHOLD = 6;
+
+ /**
+ * The smallest table capacity for which bins may be treeified.
+ * (Otherwise the table is resized if too many nodes in a bin.)
+ * The value should be at least 4 * TREEIFY_THRESHOLD to avoid
+ * conflicts between resizing and treeification thresholds.
+ */
+ static final int MIN_TREEIFY_CAPACITY = 64;
+
+ /**
+ * Minimum number of rebinnings per transfer step. Ranges are
+ * subdivided to allow multiple resizer threads. This value
+ * serves as a lower bound to avoid resizers encountering
+ * excessive memory contention. The value should be at least
+ * DEFAULT_CAPACITY.
+ */
+ private static final int MIN_TRANSFER_STRIDE = 16;
+
+ /**
+ * The number of bits used for generation stamp in sizeCtl.
+ * Must be at least 6 for 32bit arrays.
+ */
+ private static final int RESIZE_STAMP_BITS = 16;
+
+ /**
+ * The maximum number of threads that can help resize.
+ * Must fit in 32 - RESIZE_STAMP_BITS bits.
+ */
+ private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
+
+ /**
+ * The bit shift for recording size stamp in sizeCtl.
+ */
+ private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
+
+ /*
+ * Encodings for Node hash fields. See above for explanation.
+ */
+ static final int MOVED = -1; // hash for forwarding nodes
+ static final int TREEBIN = -2; // hash for roots of trees
+ static final int RESERVED = -3; // hash for transient reservations
+ static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
+
+ /** Number of CPUS, to place bounds on some sizings */
+ static final int NCPU = Runtime.getRuntime().availableProcessors();
+
+ /**
+ * Serialized pseudo-fields, provided only for jdk7 compatibility.
+ * @serialField segments Segment[]
+ * The segments, each of which is a specialized hash table.
+ * @serialField segmentMask int
+ * Mask value for indexing into segments. The upper bits of a
+ * key's hash code are used to choose the segment.
+ * @serialField segmentShift int
+ * Shift value for indexing within segments.
+ */
+ private static final ObjectStreamField[] serialPersistentFields = {
+ new ObjectStreamField("segments", Segment[].class),
+ new ObjectStreamField("segmentMask", Integer.TYPE),
+ new ObjectStreamField("segmentShift", Integer.TYPE),
+ };
+
+ /* ---------------- Nodes -------------- */
+
+ /**
+ * Key-value entry. This class is never exported out as a
+ * user-mutable Map.Entry (i.e., one supporting setValue; see
+ * MapEntry below), but can be used for read-only traversals used
+ * in bulk tasks. Subclasses of Node with a negative hash field
+ * are special, and contain null keys and values (but are never
+ * exported). Otherwise, keys and vals are never null.
+ */
+ static class Node<K,V> implements Map.Entry<K,V> {
+ final int hash;
+ final K key;
+ volatile V val;
+ volatile Node<K,V> next;
+
+ Node(int hash, K key, V val) {
+ this.hash = hash;
+ this.key = key;
+ this.val = val;
+ }
+
+ Node(int hash, K key, V val, Node<K,V> next) {
+ this(hash, key, val);
+ this.next = next;
+ }
+
+ public final K getKey() { return key; }
+ public final V getValue() { return val; }
+ public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
+ public final String toString() {
+ return Helpers.mapEntryToString(key, val);
+ }
+ public final V setValue(V value) {
+ throw new UnsupportedOperationException();
+ }
+
+ public final boolean equals(Object o) {
+ Object k, v, u; Map.Entry<?,?> e;
+ return ((o instanceof Map.Entry) &&
+ (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
+ (v = e.getValue()) != null &&
+ (k == key || k.equals(key)) &&
+ (v == (u = val) || v.equals(u)));
+ }
+
+ /**
+ * Virtualized support for map.get(); overridden in subclasses.
+ */
+ Node<K,V> find(int h, Object k) {
+ Node<K,V> e = this;
+ if (k != null) {
+ do {
+ K ek;
+ if (e.hash == h &&
+ ((ek = e.key) == k || (ek != null && k.equals(ek))))
+ return e;
+ } while ((e = e.next) != null);
+ }
+ return null;
+ }
+ }
+
+ /* ---------------- Static utilities -------------- */
+
+ /**
+ * Spreads (XORs) higher bits of hash to lower and also forces top
+ * bit 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.) So 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 (so don't benefit from
+ * spreading), and because we use trees to handle large sets of
+ * collisions in bins, we just XOR some shifted bits in the
+ * cheapest possible way to reduce systematic lossage, as well as
+ * to incorporate impact of the highest bits that would otherwise
+ * never be used in index calculations because of table bounds.
+ */
+ static final int spread(int h) {
+ return (h ^ (h >>> 16)) & HASH_BITS;
+ }
+
+ /**
+ * Returns a power of two table size for the given desired capacity.
+ * See Hackers Delight, sec 3.2
+ */
+ private static final int tableSizeFor(int c) {
+ int n = c - 1;
+ n |= n >>> 1;
+ n |= n >>> 2;
+ n |= n >>> 4;
+ n |= n >>> 8;
+ n |= n >>> 16;
+ return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
+ }
+
+ /**
+ * Returns x's Class if it is of the form "class C implements
+ * Comparable<C>", else null.
+ */
+ static Class<?> comparableClassFor(Object x) {
+ if (x instanceof Comparable) {
+ Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
+ if ((c = x.getClass()) == String.class) // bypass checks
+ return c;
+ if ((ts = c.getGenericInterfaces()) != null) {
+ for (int i = 0; i < ts.length; ++i) {
+ if (((t = ts[i]) instanceof ParameterizedType) &&
+ ((p = (ParameterizedType)t).getRawType() ==
+ Comparable.class) &&
+ (as = p.getActualTypeArguments()) != null &&
+ as.length == 1 && as[0] == c) // type arg is c
+ return c;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns k.compareTo(x) if x matches kc (k's screened comparable
+ * class), else 0.
+ */
+ @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
+ static int compareComparables(Class<?> kc, Object k, Object x) {
+ return (x == null || x.getClass() != kc ? 0 :
+ ((Comparable)k).compareTo(x));
+ }
+
+ /* ---------------- Table element access -------------- */
+
+ /*
+ * Atomic access methods are used for table elements as well as
+ * elements of in-progress next table while resizing. All uses of
+ * the tab arguments must be null checked by callers. All callers
+ * also paranoically precheck that tab's length is not zero (or an
+ * equivalent check), thus ensuring that any index argument taking
+ * the form of a hash value anded with (length - 1) is a valid
+ * index. Note that, to be correct wrt arbitrary concurrency
+ * errors by users, these checks must operate on local variables,
+ * which accounts for some odd-looking inline assignments below.
+ * Note that calls to setTabAt always occur within locked regions,
+ * and so require only release ordering.
+ */
+
+ @SuppressWarnings("unchecked")
+ static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
+ return (Node<K,V>)U.getObjectAcquire(tab, ((long)i << ASHIFT) + ABASE);
+ }
+
+ static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
+ Node<K,V> c, Node<K,V> v) {
+ return U.compareAndSetObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
+ }
+
+ static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
+ U.putObjectRelease(tab, ((long)i << ASHIFT) + ABASE, v);
+ }
+
+ /* ---------------- Fields -------------- */
+
+ /**
+ * The array of bins. Lazily initialized upon first insertion.
+ * Size is always a power of two. Accessed directly by iterators.
+ */
+ transient volatile Node<K,V>[] table;
+
+ /**
+ * The next table to use; non-null only while resizing.
+ */
+ private transient volatile Node<K,V>[] nextTable;
+
+ /**
+ * Base counter value, used mainly when there is no contention,
+ * but also as a fallback during table initialization
+ * races. Updated via CAS.
+ */
+ private transient volatile long baseCount;
+
+ /**
+ * Table initialization and resizing control. When negative, the
+ * table is being initialized or resized: -1 for initialization,
+ * else -(1 + the number of active resizing threads). Otherwise,
+ * when table is null, holds the initial table size to use upon
+ * creation, or 0 for default. After initialization, holds the
+ * next element count value upon which to resize the table.
+ */
+ private transient volatile int sizeCtl;
+
+ /**
+ * The next table index (plus one) to split while resizing.
+ */
+ private transient volatile int transferIndex;
+
+ /**
+ * Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
+ */
+ private transient volatile int cellsBusy;
+
+ /**
+ * Table of counter cells. When non-null, size is a power of 2.
+ */
+ private transient volatile CounterCell[] counterCells;
+
+ // views
+ private transient KeySetView<K,V> keySet;
+ private transient ValuesView<K,V> values;
+ private transient EntrySetView<K,V> entrySet;
+
+
+ /* ---------------- Public operations -------------- */
+
+ /**
+ * Creates a new, empty map with the default initial table size (16).
+ */
+ public ConcurrentHashMap() {
+ }
+
+ /**
+ * Creates a new, empty map with an initial table size
+ * accommodating the specified number of elements without the need
+ * to dynamically resize.
+ *
+ * @param initialCapacity The implementation performs internal
+ * sizing to accommodate this many elements.
+ * @throws IllegalArgumentException if the initial capacity of
+ * elements is negative
+ */
+ public ConcurrentHashMap(int initialCapacity) {
+ if (initialCapacity < 0)
+ throw new IllegalArgumentException();
+ int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
+ MAXIMUM_CAPACITY :
+ tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
+ this.sizeCtl = cap;
+ }
+
+ /**
+ * Creates a new map with the same mappings as the given map.
+ *
+ * @param m the map
+ */
+ public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
+ this.sizeCtl = DEFAULT_CAPACITY;
+ putAll(m);
+ }
+
+ /**
+ * Creates a new, empty map with an initial table size based on
+ * the given number of elements ({@code initialCapacity}) and
+ * initial table density ({@code loadFactor}).
+ *
+ * @param initialCapacity the initial capacity. The implementation
+ * performs internal sizing to accommodate this many elements,
+ * given the specified load factor.
+ * @param loadFactor the load factor (table density) for
+ * establishing the initial table size
+ * @throws IllegalArgumentException if the initial capacity of
+ * elements is negative or the load factor is nonpositive
+ *
+ * @since 1.6
+ */
+ public ConcurrentHashMap(int initialCapacity, float loadFactor) {
+ this(initialCapacity, loadFactor, 1);
+ }
+
+ /**
+ * Creates a new, empty map with an initial table size based on
+ * the given number of elements ({@code initialCapacity}), table
+ * density ({@code loadFactor}), and number of concurrently
+ * updating threads ({@code concurrencyLevel}).
+ *
+ * @param initialCapacity the initial capacity. The implementation
+ * performs internal sizing to accommodate this many elements,
+ * given the specified load factor.
+ * @param loadFactor the load factor (table density) for
+ * establishing the initial table size
+ * @param concurrencyLevel the estimated number of concurrently
+ * updating threads. The implementation may use this value as
+ * a sizing hint.
+ * @throws IllegalArgumentException if the initial capacity is
+ * negative or the load factor or concurrencyLevel are
+ * nonpositive
+ */
+ public ConcurrentHashMap(int initialCapacity,
+ float loadFactor, int concurrencyLevel) {
+ if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
+ throw new IllegalArgumentException();
+ 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);
+ this.sizeCtl = cap;
+ }
+
+ // Original (since JDK1.2) Map methods
+
+ /**
+ * {@inheritDoc}
+ */
+ public int size() {
+ long n = sumCount();
+ return ((n < 0L) ? 0 :
+ (n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
+ (int)n);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public boolean isEmpty() {
+ return sumCount() <= 0L; // ignore transient negative values
+ }
+
+ /**
+ * Returns the value to which the specified key is mapped,
+ * or {@code null} if this map contains no mapping for the key.
+ *
+ * <p>More formally, if this map contains a mapping from a key
+ * {@code k} to a value {@code v} such that {@code key.equals(k)},
+ * then this method returns {@code v}; otherwise it returns
+ * {@code null}. (There can be at most one such mapping.)
+ *
+ * @throws NullPointerException if the specified key is null
+ */
+ public V get(Object key) {
+ Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
+ int h = spread(key.hashCode());
+ if ((tab = table) != null && (n = tab.length) > 0 &&
+ (e = tabAt(tab, (n - 1) & h)) != null) {
+ if ((eh = e.hash) == h) {
+ if ((ek = e.key) == key || (ek != null && key.equals(ek)))
+ return e.val;
+ }
+ else if (eh < 0)
+ return (p = e.find(h, key)) != null ? p.val : null;
+ while ((e = e.next) != null) {
+ if (e.hash == h &&
+ ((ek = e.key) == key || (ek != null && key.equals(ek))))
+ return e.val;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Tests if the specified object is a key in this table.
+ *
+ * @param key possible key
+ * @return {@code true} if and only if the specified object
+ * is a key in this table, as determined by the
+ * {@code equals} method; {@code false} otherwise
+ * @throws NullPointerException if the specified key is null
+ */
+ public boolean containsKey(Object key) {
+ return get(key) != null;
+ }
+
+ /**
+ * Returns {@code true} if this map maps one or more keys to the
+ * specified value. Note: This method may require a full traversal
+ * of the map, and is much slower than method {@code containsKey}.
+ *
+ * @param value value whose presence in this map is to be tested
+ * @return {@code true} if this map maps one or more keys to the
+ * specified value
+ * @throws NullPointerException if the specified value is null
+ */
+ public boolean containsValue(Object value) {
+ if (value == null)
+ throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ V v;
+ if ((v = p.val) == value || (v != null && value.equals(v)))
+ return true;
+ }
+ }
+ 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
+ * with a key that is equal to the original key.
+ *
+ * @param key key with which the specified value is to be associated
+ * @param value value to be associated with the specified key
+ * @return the previous value associated with {@code key}, or
+ * {@code null} if there was no mapping for {@code key}
+ * @throws NullPointerException if the specified key or value is null
+ */
+ public V put(K key, V value) {
+ return putVal(key, value, false);
+ }
+
+ /** Implementation for put and putIfAbsent */
+ final V putVal(K key, V value, boolean onlyIfAbsent) {
+ if (key == null || value == null) throw new NullPointerException();
+ int hash = spread(key.hashCode());
+ int binCount = 0;
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh; K fk; V fv;
+ if (tab == null || (n = tab.length) == 0)
+ tab = initTable();
+ else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
+ if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
+ break; // no lock when adding to empty bin
+ }
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else if (onlyIfAbsent // check first node without acquiring lock
+ && fh == hash
+ && ((fk = f.key) == key || (fk != null && key.equals(fk)))
+ && (fv = f.val) != null)
+ return fv;
+ else {
+ V oldVal = null;
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ binCount = 1;
+ for (Node<K,V> e = f;; ++binCount) {
+ K ek;
+ if (e.hash == hash &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ oldVal = e.val;
+ if (!onlyIfAbsent)
+ e.val = value;
+ break;
+ }
+ Node<K,V> pred = e;
+ if ((e = e.next) == null) {
+ pred.next = new Node<K,V>(hash, key, value);
+ break;
+ }
+ }
+ }
+ else if (f instanceof TreeBin) {
+ Node<K,V> p;
+ binCount = 2;
+ if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
+ value)) != null) {
+ oldVal = p.val;
+ if (!onlyIfAbsent)
+ p.val = value;
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (binCount != 0) {
+ if (binCount >= TREEIFY_THRESHOLD)
+ treeifyBin(tab, i);
+ if (oldVal != null)
+ return oldVal;
+ break;
+ }
+ }
+ }
+ addCount(1L, binCount);
+ return null;
+ }
+
+ /**
+ * Copies all of the mappings from the specified map to this one.
+ * These mappings replace any mappings that this map had for any of the
+ * keys currently in the specified map.
+ *
+ * @param m mappings to be stored in this map
+ */
+ public void putAll(Map<? extends K, ? extends V> m) {
+ tryPresize(m.size());
+ for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
+ putVal(e.getKey(), e.getValue(), false);
+ }
+
+ /**
+ * Removes the key (and its corresponding value) from this map.
+ * This method does nothing if the key is not in the map.
+ *
+ * @param key the key that needs to be removed
+ * @return the previous value associated with {@code key}, or
+ * {@code null} if there was no mapping for {@code key}
+ * @throws NullPointerException if the specified key is null
+ */
+ public V remove(Object key) {
+ return replaceNode(key, null, null);
+ }
+
+ /**
+ * Implementation for the four public remove/replace methods:
+ * Replaces node value with v, conditional upon match of cv if
+ * non-null. If resulting value is null, delete.
+ */
+ final V replaceNode(Object key, V value, Object cv) {
+ int hash = spread(key.hashCode());
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh;
+ if (tab == null || (n = tab.length) == 0 ||
+ (f = tabAt(tab, i = (n - 1) & hash)) == null)
+ break;
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else {
+ V oldVal = null;
+ boolean validated = false;
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ validated = true;
+ for (Node<K,V> e = f, pred = null;;) {
+ K ek;
+ if (e.hash == hash &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ V ev = e.val;
+ if (cv == null || cv == ev ||
+ (ev != null && cv.equals(ev))) {
+ oldVal = ev;
+ if (value != null)
+ e.val = value;
+ else if (pred != null)
+ pred.next = e.next;
+ else
+ setTabAt(tab, i, e.next);
+ }
+ break;
+ }
+ pred = e;
+ if ((e = e.next) == null)
+ break;
+ }
+ }
+ else if (f instanceof TreeBin) {
+ validated = true;
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> r, p;
+ if ((r = t.root) != null &&
+ (p = r.findTreeNode(hash, key, null)) != null) {
+ V pv = p.val;
+ if (cv == null || cv == pv ||
+ (pv != null && cv.equals(pv))) {
+ oldVal = pv;
+ if (value != null)
+ p.val = value;
+ else if (t.removeTreeNode(p))
+ setTabAt(tab, i, untreeify(t.first));
+ }
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (validated) {
+ if (oldVal != null) {
+ if (value == null)
+ addCount(-1L, -1);
+ return oldVal;
+ }
+ break;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Removes all of the mappings from this map.
+ */
+ public void clear() {
+ long delta = 0L; // negative number of deletions
+ int i = 0;
+ Node<K,V>[] tab = table;
+ while (tab != null && i < tab.length) {
+ int fh;
+ Node<K,V> f = tabAt(tab, i);
+ if (f == null)
+ ++i;
+ else if ((fh = f.hash) == MOVED) {
+ tab = helpTransfer(tab, f);
+ i = 0; // restart
+ }
+ else {
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ Node<K,V> p = (fh >= 0 ? f :
+ (f instanceof TreeBin) ?
+ ((TreeBin<K,V>)f).first : null);
+ while (p != null) {
+ --delta;
+ p = p.next;
+ }
+ setTabAt(tab, i++, null);
+ }
+ }
+ }
+ }
+ if (delta != 0L)
+ addCount(delta, -1);
+ }
+
+ /**
+ * 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.
+ *
+ * <p>The view's iterators and spliterators are
+ * <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
+ *
+ * <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
+ * {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
+ *
+ * @return the set view
+ */
+ public KeySetView<K,V> keySet() {
+ KeySetView<K,V> ks;
+ if ((ks = keySet) != null) return ks;
+ return keySet = new KeySetView<K,V>(this, null);
+ }
+
+ /**
+ * 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 iterators and spliterators are
+ * <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
+ *
+ * <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
+ * and {@link Spliterator#NONNULL}.
+ *
+ * @return the collection view
+ */
+ public Collection<V> values() {
+ ValuesView<K,V> vs;
+ if ((vs = values) != null) return vs;
+ return values = new ValuesView<K,V>(this);
+ }
+
+ /**
+ * Returns a {@link Set} view of the mappings 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 the map,
+ * via the {@code Iterator.remove}, {@code Set.remove},
+ * {@code removeAll}, {@code retainAll}, and {@code clear}
+ * operations.
+ *
+ * <p>The view's iterators and spliterators are
+ * <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
+ *
+ * <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
+ * {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
+ *
+ * @return the set view
+ */
+ public Set<Map.Entry<K,V>> entrySet() {
+ EntrySetView<K,V> es;
+ if ((es = entrySet) != null) return es;
+ return entrySet = new EntrySetView<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()}.
+ *
+ * @return the hash code value for this map
+ */
+ public int hashCode() {
+ int h = 0;
+ Node<K,V>[] t;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; )
+ h += p.key.hashCode() ^ p.val.hashCode();
+ }
+ return h;
+ }
+
+ /**
+ * Returns a string representation of this map. The string
+ * representation consists of a list of key-value mappings (in no
+ * particular order) enclosed in braces ("{@code {}}"). Adjacent
+ * mappings are separated by the characters {@code ", "} (comma
+ * and space). Each key-value mapping is rendered as the key
+ * followed by an equals sign ("{@code =}") followed by the
+ * associated value.
+ *
+ * @return a string representation of this map
+ */
+ public String toString() {
+ Node<K,V>[] t;
+ int f = (t = table) == null ? 0 : t.length;
+ Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
+ StringBuilder sb = new StringBuilder();
+ sb.append('{');
+ Node<K,V> p;
+ if ((p = it.advance()) != null) {
+ for (;;) {
+ K k = p.key;
+ V v = p.val;
+ sb.append(k == this ? "(this Map)" : k);
+ sb.append('=');
+ sb.append(v == this ? "(this Map)" : v);
+ if ((p = it.advance()) == null)
+ break;
+ sb.append(',').append(' ');
+ }
+ }
+ return sb.append('}').toString();
+ }
+
+ /**
+ * Compares the specified object with this map for equality.
+ * Returns {@code true} if the given object is a map with the same
+ * mappings as this map. This operation may return misleading
+ * results if either map is concurrently modified during execution
+ * of this method.
+ *
+ * @param o object to be compared for equality with this map
+ * @return {@code true} if the specified object is equal to this map
+ */
+ public boolean equals(Object o) {
+ if (o != this) {
+ if (!(o instanceof Map))
+ return false;
+ Map<?,?> m = (Map<?,?>) o;
+ Node<K,V>[] t;
+ int f = (t = table) == null ? 0 : t.length;
+ Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ V val = p.val;
+ Object v = m.get(p.key);
+ if (v == null || (v != val && !v.equals(val)))
+ return false;
+ }
+ for (Map.Entry<?,?> e : m.entrySet()) {
+ Object mk, mv, v;
+ if ((mk = e.getKey()) == null ||
+ (mv = e.getValue()) == null ||
+ (v = get(mk)) == null ||
+ (mv != v && !mv.equals(v)))
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Stripped-down version of helper class used in previous version,
+ * declared for the sake of serialization compatibility.
+ */
+ static class Segment<K,V> extends ReentrantLock implements Serializable {
+ private static final long serialVersionUID = 2249069246763182397L;
+ final float loadFactor;
+ Segment(float lf) { this.loadFactor = lf; }
+ }
+
+ /**
+ * Saves the state of the {@code ConcurrentHashMap} instance to a
+ * stream (i.e., serializes it).
+ * @param s the stream
+ * @throws java.io.IOException if an I/O error occurs
+ * @serialData
+ * the serialized fields, followed by 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.
+ */
+ private void writeObject(java.io.ObjectOutputStream s)
+ throws java.io.IOException {
+ // For serialization compatibility
+ // Emulate segment calculation from previous version of this class
+ int sshift = 0;
+ int ssize = 1;
+ while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
+ ++sshift;
+ ssize <<= 1;
+ }
+ int segmentShift = 32 - sshift;
+ int segmentMask = ssize - 1;
+ @SuppressWarnings("unchecked")
+ Segment<K,V>[] 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);
+ java.io.ObjectOutputStream.PutField streamFields = s.putFields();
+ streamFields.put("segments", segments);
+ streamFields.put("segmentShift", segmentShift);
+ streamFields.put("segmentMask", segmentMask);
+ s.writeFields();
+
+ Node<K,V>[] t;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ s.writeObject(p.key);
+ s.writeObject(p.val);
+ }
+ }
+ s.writeObject(null);
+ s.writeObject(null);
+ }
+
+ /**
+ * Reconstitutes the instance from a stream (that is, deserializes it).
+ * @param s the stream
+ * @throws ClassNotFoundException if the class of a serialized object
+ * could not be found
+ * @throws java.io.IOException if an I/O error occurs
+ */
+ private void readObject(java.io.ObjectInputStream s)
+ throws java.io.IOException, ClassNotFoundException {
+ /*
+ * To improve performance in typical cases, we create nodes
+ * while reading, then place in table once size is known.
+ * However, we must also validate uniqueness and deal with
+ * overpopulated bins while doing so, which requires
+ * specialized versions of putVal mechanics.
+ */
+ sizeCtl = -1; // force exclusion for table construction
+ s.defaultReadObject();
+ long size = 0L;
+ Node<K,V> p = null;
+ for (;;) {
+ @SuppressWarnings("unchecked")
+ K k = (K) s.readObject();
+ @SuppressWarnings("unchecked")
+ V v = (V) s.readObject();
+ if (k != null && v != null) {
+ p = new Node<K,V>(spread(k.hashCode()), k, v, p);
+ ++size;
+ }
+ else
+ break;
+ }
+ if (size == 0L)
+ sizeCtl = 0;
+ else {
+ int n;
+ if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
+ n = MAXIMUM_CAPACITY;
+ else {
+ int sz = (int)size;
+ n = tableSizeFor(sz + (sz >>> 1) + 1);
+ }
+ @SuppressWarnings("unchecked")
+ Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
+ int mask = n - 1;
+ long added = 0L;
+ while (p != null) {
+ boolean insertAtFront;
+ Node<K,V> next = p.next, first;
+ int h = p.hash, j = h & mask;
+ if ((first = tabAt(tab, j)) == null)
+ insertAtFront = true;
+ else {
+ K k = p.key;
+ if (first.hash < 0) {
+ TreeBin<K,V> t = (TreeBin<K,V>)first;
+ if (t.putTreeVal(h, k, p.val) == null)
+ ++added;
+ insertAtFront = false;
+ }
+ else {
+ int binCount = 0;
+ insertAtFront = true;
+ Node<K,V> q; K qk;
+ for (q = first; q != null; q = q.next) {
+ if (q.hash == h &&
+ ((qk = q.key) == k ||
+ (qk != null && k.equals(qk)))) {
+ insertAtFront = false;
+ break;
+ }
+ ++binCount;
+ }
+ if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
+ insertAtFront = false;
+ ++added;
+ p.next = first;
+ TreeNode<K,V> hd = null, tl = null;
+ for (q = p; q != null; q = q.next) {
+ TreeNode<K,V> t = new TreeNode<K,V>
+ (q.hash, q.key, q.val, null, null);
+ if ((t.prev = tl) == null)
+ hd = t;
+ else
+ tl.next = t;
+ tl = t;
+ }
+ setTabAt(tab, j, new TreeBin<K,V>(hd));
+ }
+ }
+ }
+ if (insertAtFront) {
+ ++added;
+ p.next = first;
+ setTabAt(tab, j, p);
+ }
+ p = next;
+ }
+ table = tab;
+ sizeCtl = n - (n >>> 2);
+ baseCount = added;
+ }
+ }
+
+ // ConcurrentMap methods
+
+ /**
+ * {@inheritDoc}
+ *
+ * @return the previous value associated with the specified key,
+ * or {@code null} if there was no mapping for the key
+ * @throws NullPointerException if the specified key or value is null
+ */
+ public V putIfAbsent(K key, V value) {
+ return putVal(key, value, true);
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @throws NullPointerException if the specified key is null
+ */
+ public boolean remove(Object key, Object value) {
+ if (key == null)
+ throw new NullPointerException();
+ return value != null && replaceNode(key, null, value) != null;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @throws NullPointerException if any of the arguments are null
+ */
+ public boolean replace(K key, V oldValue, V newValue) {
+ if (key == null || oldValue == null || newValue == null)
+ throw new NullPointerException();
+ return replaceNode(key, newValue, oldValue) != null;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @return the previous value associated with the specified key,
+ * or {@code null} if there was no mapping for the key
+ * @throws NullPointerException if the specified key or value is null
+ */
+ public V replace(K key, V value) {
+ if (key == null || value == null)
+ throw new NullPointerException();
+ return replaceNode(key, value, null);
+ }
+
+ // Overrides of JDK8+ Map extension method defaults
+
+ /**
+ * Returns the value to which the specified key is mapped, or the
+ * given default value if this map contains no mapping for the
+ * key.
+ *
+ * @param key the key whose associated value is to be returned
+ * @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 default value
+ * @throws NullPointerException if the specified key is null
+ */
+ public V getOrDefault(Object key, V defaultValue) {
+ V v;
+ return (v = get(key)) == null ? defaultValue : v;
+ }
+
+ public void forEach(BiConsumer<? super K, ? super V> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ action.accept(p.key, p.val);
+ }
+ }
+ }
+
+ public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
+ if (function == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ V oldValue = p.val;
+ for (K key = p.key;;) {
+ V newValue = function.apply(key, oldValue);
+ if (newValue == null)
+ throw new NullPointerException();
+ if (replaceNode(key, newValue, oldValue) != null ||
+ (oldValue = get(key)) == null)
+ break;
+ }
+ }
+ }
+ }
+
+ /**
+ * Helper method for EntrySetView.removeIf.
+ */
+ boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
+ if (function == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ boolean removed = false;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ K k = p.key;
+ V v = p.val;
+ Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
+ if (function.test(e) && replaceNode(k, null, v) != null)
+ removed = true;
+ }
+ }
+ return removed;
+ }
+
+ /**
+ * Helper method for ValuesView.removeIf.
+ */
+ boolean removeValueIf(Predicate<? super V> function) {
+ if (function == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ boolean removed = false;
+ if ((t = table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ K k = p.key;
+ V v = p.val;
+ if (function.test(v) && replaceNode(k, null, v) != null)
+ removed = true;
+ }
+ }
+ return removed;
+ }
+
+ /**
+ * If the specified key is not already associated with a value,
+ * attempts to compute its value using the given mapping function
+ * and enters it into this map unless {@code null}. The entire
+ * method invocation is performed atomically, so the function is
+ * applied at most once per key. 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.
+ *
+ * @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, 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
+ */
+ public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
+ if (key == null || mappingFunction == null)
+ throw new NullPointerException();
+ int h = spread(key.hashCode());
+ V val = null;
+ int binCount = 0;
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh; K fk; V fv;
+ if (tab == null || (n = tab.length) == 0)
+ tab = initTable();
+ else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
+ Node<K,V> r = new ReservationNode<K,V>();
+ synchronized (r) {
+ if (casTabAt(tab, i, null, r)) {
+ binCount = 1;
+ Node<K,V> node = null;
+ try {
+ if ((val = mappingFunction.apply(key)) != null)
+ node = new Node<K,V>(h, key, val);
+ } finally {
+ setTabAt(tab, i, node);
+ }
+ }
+ }
+ if (binCount != 0)
+ break;
+ }
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else if (fh == h // check first node without acquiring lock
+ && ((fk = f.key) == key || (fk != null && key.equals(fk)))
+ && (fv = f.val) != null)
+ return fv;
+ else {
+ boolean added = false;
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ binCount = 1;
+ for (Node<K,V> e = f;; ++binCount) {
+ K ek;
+ if (e.hash == h &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ val = e.val;
+ break;
+ }
+ Node<K,V> pred = e;
+ if ((e = e.next) == null) {
+ if ((val = mappingFunction.apply(key)) != null) {
+ if (pred.next != null)
+ throw new IllegalStateException("Recursive update");
+ added = true;
+ pred.next = new Node<K,V>(h, key, val);
+ }
+ break;
+ }
+ }
+ }
+ else if (f instanceof TreeBin) {
+ binCount = 2;
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> r, p;
+ if ((r = t.root) != null &&
+ (p = r.findTreeNode(h, key, null)) != null)
+ val = p.val;
+ else if ((val = mappingFunction.apply(key)) != null) {
+ added = true;
+ t.putTreeVal(h, key, val);
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (binCount != 0) {
+ if (binCount >= TREEIFY_THRESHOLD)
+ treeifyBin(tab, i);
+ if (!added)
+ return val;
+ break;
+ }
+ }
+ }
+ if (val != null)
+ addCount(1L, binCount);
+ return val;
+ }
+
+ /**
+ * If the value for the specified key is present, attempts to
+ * compute a new mapping given the key and its current mapped
+ * value. The entire method invocation is performed atomically.
+ * 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.
+ *
+ * @param key key with which a value may 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
+ */
+ public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+ if (key == null || remappingFunction == null)
+ throw new NullPointerException();
+ int h = spread(key.hashCode());
+ V val = null;
+ int delta = 0;
+ int binCount = 0;
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh;
+ if (tab == null || (n = tab.length) == 0)
+ tab = initTable();
+ else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
+ break;
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else {
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ binCount = 1;
+ for (Node<K,V> e = f, pred = null;; ++binCount) {
+ K ek;
+ if (e.hash == h &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ val = remappingFunction.apply(key, e.val);
+ if (val != null)
+ e.val = val;
+ else {
+ delta = -1;
+ Node<K,V> en = e.next;
+ if (pred != null)
+ pred.next = en;
+ else
+ setTabAt(tab, i, en);
+ }
+ break;
+ }
+ pred = e;
+ if ((e = e.next) == null)
+ break;
+ }
+ }
+ else if (f instanceof TreeBin) {
+ binCount = 2;
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> r, p;
+ if ((r = t.root) != null &&
+ (p = r.findTreeNode(h, key, null)) != null) {
+ val = remappingFunction.apply(key, p.val);
+ if (val != null)
+ p.val = val;
+ else {
+ delta = -1;
+ if (t.removeTreeNode(p))
+ setTabAt(tab, i, untreeify(t.first));
+ }
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (binCount != 0)
+ break;
+ }
+ }
+ if (delta != 0)
+ addCount((long)delta, binCount);
+ return val;
+ }
+
+ /**
+ * Attempts to compute a mapping for the specified key and its
+ * current mapped value (or {@code null} if there is no current
+ * mapping). The entire method invocation is performed atomically.
+ * 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.
+ *
+ * @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
+ */
+ public V compute(K key,
+ BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+ if (key == null || remappingFunction == null)
+ throw new NullPointerException();
+ int h = spread(key.hashCode());
+ V val = null;
+ int delta = 0;
+ int binCount = 0;
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh;
+ if (tab == null || (n = tab.length) == 0)
+ tab = initTable();
+ else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
+ Node<K,V> r = new ReservationNode<K,V>();
+ synchronized (r) {
+ if (casTabAt(tab, i, null, r)) {
+ binCount = 1;
+ Node<K,V> node = null;
+ try {
+ if ((val = remappingFunction.apply(key, null)) != null) {
+ delta = 1;
+ node = new Node<K,V>(h, key, val);
+ }
+ } finally {
+ setTabAt(tab, i, node);
+ }
+ }
+ }
+ if (binCount != 0)
+ break;
+ }
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else {
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ binCount = 1;
+ for (Node<K,V> e = f, pred = null;; ++binCount) {
+ K ek;
+ if (e.hash == h &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ val = remappingFunction.apply(key, e.val);
+ if (val != null)
+ e.val = val;
+ else {
+ delta = -1;
+ Node<K,V> en = e.next;
+ if (pred != null)
+ pred.next = en;
+ else
+ setTabAt(tab, i, en);
+ }
+ break;
+ }
+ pred = e;
+ if ((e = e.next) == null) {
+ val = remappingFunction.apply(key, null);
+ if (val != null) {
+ if (pred.next != null)
+ throw new IllegalStateException("Recursive update");
+ delta = 1;
+ pred.next = new Node<K,V>(h, key, val);
+ }
+ break;
+ }
+ }
+ }
+ else if (f instanceof TreeBin) {
+ binCount = 1;
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> r, p;
+ if ((r = t.root) != null)
+ p = r.findTreeNode(h, key, null);
+ else
+ p = null;
+ V pv = (p == null) ? null : p.val;
+ val = remappingFunction.apply(key, pv);
+ if (val != null) {
+ if (p != null)
+ p.val = val;
+ else {
+ delta = 1;
+ t.putTreeVal(h, key, val);
+ }
+ }
+ else if (p != null) {
+ delta = -1;
+ if (t.removeTreeNode(p))
+ setTabAt(tab, i, untreeify(t.first));
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (binCount != 0) {
+ if (binCount >= TREEIFY_THRESHOLD)
+ treeifyBin(tab, i);
+ break;
+ }
+ }
+ }
+ if (delta != 0)
+ addCount((long)delta, binCount);
+ return val;
+ }
+
+ /**
+ * If the specified key is not already associated with a
+ * (non-null) value, associates it with the given value.
+ * Otherwise, replaces the value with the results of the given
+ * remapping function, or removes if {@code null}. The entire
+ * method invocation is performed atomically. 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.
+ *
+ * @param key key with which the specified value is to be associated
+ * @param value the value to use if absent
+ * @param remappingFunction the function to recompute a value if present
+ * @return the new value associated with the specified key, or null if none
+ * @throws NullPointerException if the specified key or the
+ * remappingFunction is null
+ * @throws RuntimeException or Error if the remappingFunction does so,
+ * in which case the mapping is unchanged
+ */
+ public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
+ if (key == null || value == null || remappingFunction == null)
+ throw new NullPointerException();
+ int h = spread(key.hashCode());
+ V val = null;
+ int delta = 0;
+ int binCount = 0;
+ for (Node<K,V>[] tab = table;;) {
+ Node<K,V> f; int n, i, fh;
+ if (tab == null || (n = tab.length) == 0)
+ tab = initTable();
+ else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
+ if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
+ delta = 1;
+ val = value;
+ break;
+ }
+ }
+ else if ((fh = f.hash) == MOVED)
+ tab = helpTransfer(tab, f);
+ else {
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ if (fh >= 0) {
+ binCount = 1;
+ for (Node<K,V> e = f, pred = null;; ++binCount) {
+ K ek;
+ if (e.hash == h &&
+ ((ek = e.key) == key ||
+ (ek != null && key.equals(ek)))) {
+ val = remappingFunction.apply(e.val, value);
+ if (val != null)
+ e.val = val;
+ else {
+ delta = -1;
+ Node<K,V> en = e.next;
+ if (pred != null)
+ pred.next = en;
+ else
+ setTabAt(tab, i, en);
+ }
+ break;
+ }
+ pred = e;
+ if ((e = e.next) == null) {
+ delta = 1;
+ val = value;
+ pred.next = new Node<K,V>(h, key, val);
+ break;
+ }
+ }
+ }
+ else if (f instanceof TreeBin) {
+ binCount = 2;
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> r = t.root;
+ TreeNode<K,V> p = (r == null) ? null :
+ r.findTreeNode(h, key, null);
+ val = (p == null) ? value :
+ remappingFunction.apply(p.val, value);
+ if (val != null) {
+ if (p != null)
+ p.val = val;
+ else {
+ delta = 1;
+ t.putTreeVal(h, key, val);
+ }
+ }
+ else if (p != null) {
+ delta = -1;
+ if (t.removeTreeNode(p))
+ setTabAt(tab, i, untreeify(t.first));
+ }
+ }
+ else if (f instanceof ReservationNode)
+ throw new IllegalStateException("Recursive update");
+ }
+ }
+ if (binCount != 0) {
+ if (binCount >= TREEIFY_THRESHOLD)
+ treeifyBin(tab, i);
+ break;
+ }
+ }
+ }
+ if (delta != 0)
+ addCount((long)delta, binCount);
+ return val;
+ }
+
+ // Hashtable legacy methods
+
+ /**
+ * Tests if some key maps into the specified value in this table.
+ *
+ * <p>Note that this method is identical in functionality to
+ * {@link #containsValue(Object)}, and exists solely to ensure
+ * full compatibility with class {@link java.util.Hashtable},
+ * which supported this method prior to introduction of the
+ * Java Collections Framework.
+ *
+ * @param value a value to search for
+ * @return {@code true} if and only if some key maps to the
+ * {@code value} argument in this table as
+ * determined by the {@code equals} method;
+ * {@code false} otherwise
+ * @throws NullPointerException if the specified value is null
+ */
+ public boolean contains(Object value) {
+ return containsValue(value);
+ }
+
+ /**
+ * Returns an enumeration of the keys in this table.
+ *
+ * @return an enumeration of the keys in this table
+ * @see #keySet()
+ */
+ public Enumeration<K> keys() {
+ Node<K,V>[] t;
+ int f = (t = table) == null ? 0 : t.length;
+ return new KeyIterator<K,V>(t, f, 0, f, this);
+ }
+
+ /**
+ * Returns an enumeration of the values in this table.
+ *
+ * @return an enumeration of the values in this table
+ * @see #values()
+ */
+ public Enumeration<V> elements() {
+ Node<K,V>[] t;
+ int f = (t = table) == null ? 0 : t.length;
+ return new ValueIterator<K,V>(t, f, 0, f, this);
+ }
+
+ // ConcurrentHashMap-only methods
+
+ /**
+ * Returns the number of mappings. This method should be used
+ * instead of {@link #size} because a ConcurrentHashMap 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
+ * @since 1.8
+ */
+ public long mappingCount() {
+ long n = sumCount();
+ return (n < 0L) ? 0L : n; // ignore transient negative values
+ }
+
+ /**
+ * Creates a new {@link Set} backed by a ConcurrentHashMap
+ * from the given type to {@code Boolean.TRUE}.
+ *
+ * @param <K> the element type of the returned set
+ * @return the new set
+ * @since 1.8
+ */
+ public static <K> KeySetView<K,Boolean> newKeySet() {
+ return new KeySetView<K,Boolean>
+ (new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
+ }
+
+ /**
+ * Creates a new {@link Set} backed by a ConcurrentHashMap
+ * from the given type to {@code Boolean.TRUE}.
+ *
+ * @param initialCapacity The implementation performs internal
+ * sizing to accommodate this many elements.
+ * @param <K> the element type of the returned set
+ * @return the new set
+ * @throws IllegalArgumentException if the initial capacity of
+ * elements is negative
+ * @since 1.8
+ */
+ public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
+ return new KeySetView<K,Boolean>
+ (new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
+ }
+
+ /**
+ * 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(Collection)}).
+ * 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);
+ }
+
+ /* ---------------- Special Nodes -------------- */
+
+ /**
+ * A node inserted at head of bins during transfer operations.
+ */
+ static final class ForwardingNode<K,V> extends Node<K,V> {
+ final Node<K,V>[] nextTable;
+ ForwardingNode(Node<K,V>[] tab) {
+ super(MOVED, null, null);
+ this.nextTable = tab;
+ }
+
+ Node<K,V> find(int h, Object k) {
+ // loop to avoid arbitrarily deep recursion on forwarding nodes
+ outer: for (Node<K,V>[] tab = nextTable;;) {
+ Node<K,V> e; int n;
+ if (k == null || tab == null || (n = tab.length) == 0 ||
+ (e = tabAt(tab, (n - 1) & h)) == null)
+ return null;
+ for (;;) {
+ int eh; K ek;
+ if ((eh = e.hash) == h &&
+ ((ek = e.key) == k || (ek != null && k.equals(ek))))
+ return e;
+ if (eh < 0) {
+ if (e instanceof ForwardingNode) {
+ tab = ((ForwardingNode<K,V>)e).nextTable;
+ continue outer;
+ }
+ else
+ return e.find(h, k);
+ }
+ if ((e = e.next) == null)
+ return null;
+ }
+ }
+ }
+ }
+
+ /**
+ * A place-holder node used in computeIfAbsent and compute.
+ */
+ static final class ReservationNode<K,V> extends Node<K,V> {
+ ReservationNode() {
+ super(RESERVED, null, null);
+ }
+
+ Node<K,V> find(int h, Object k) {
+ return null;
+ }
+ }
+
+ /* ---------------- Table Initialization and Resizing -------------- */
+
+ /**
+ * Returns the stamp bits for resizing a table of size n.
+ * Must be negative when shifted left by RESIZE_STAMP_SHIFT.
+ */
+ static final int resizeStamp(int n) {
+ return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
+ }
+
+ /**
+ * Initializes table, using the size recorded in sizeCtl.
+ */
+ private final Node<K,V>[] initTable() {
+ Node<K,V>[] tab; int sc;
+ while ((tab = table) == null || tab.length == 0) {
+ if ((sc = sizeCtl) < 0)
+ Thread.yield(); // lost initialization race; just spin
+ else if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
+ try {
+ if ((tab = table) == null || tab.length == 0) {
+ int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
+ @SuppressWarnings("unchecked")
+ Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
+ table = tab = nt;
+ sc = n - (n >>> 2);
+ }
+ } finally {
+ sizeCtl = sc;
+ }
+ break;
+ }
+ }
+ return tab;
+ }
+
+ /**
+ * Adds to count, and if table is too small and not already
+ * resizing, initiates transfer. If already resizing, helps
+ * perform transfer if work is available. Rechecks occupancy
+ * after a transfer to see if another resize is already needed
+ * because resizings are lagging additions.
+ *
+ * @param x the count to add
+ * @param check if <0, don't check resize, if <= 1 only check if uncontended
+ */
+ private final void addCount(long x, int check) {
+ CounterCell[] as; long b, s;
+ if ((as = counterCells) != null ||
+ !U.compareAndSetLong(this, BASECOUNT, b = baseCount, s = b + x)) {
+ CounterCell a; long v; int m;
+ boolean uncontended = true;
+ if (as == null || (m = as.length - 1) < 0 ||
+ (a = as[ThreadLocalRandom.getProbe() & m]) == null ||
+ !(uncontended =
+ U.compareAndSetLong(a, CELLVALUE, v = a.value, v + x))) {
+ fullAddCount(x, uncontended);
+ return;
+ }
+ if (check <= 1)
+ return;
+ s = sumCount();
+ }
+ if (check >= 0) {
+ Node<K,V>[] tab, nt; int n, sc;
+ while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
+ (n = tab.length) < MAXIMUM_CAPACITY) {
+ int rs = resizeStamp(n);
+ if (sc < 0) {
+ if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
+ sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
+ transferIndex <= 0)
+ break;
+ if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
+ transfer(tab, nt);
+ }
+ else if (U.compareAndSetInt(this, SIZECTL, sc,
+ (rs << RESIZE_STAMP_SHIFT) + 2))
+ transfer(tab, null);
+ s = sumCount();
+ }
+ }
+ }
+
+ /**
+ * Helps transfer if a resize is in progress.
+ */
+ final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
+ Node<K,V>[] nextTab; int sc;
+ if (tab != null && (f instanceof ForwardingNode) &&
+ (nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
+ int rs = resizeStamp(tab.length);
+ while (nextTab == nextTable && table == tab &&
+ (sc = sizeCtl) < 0) {
+ if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
+ sc == rs + MAX_RESIZERS || transferIndex <= 0)
+ break;
+ if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
+ transfer(tab, nextTab);
+ break;
+ }
+ }
+ return nextTab;
+ }
+ return table;
+ }
+
+ /**
+ * Tries to presize table to accommodate the given number of elements.
+ *
+ * @param size number of elements (doesn't need to be perfectly accurate)
+ */
+ private final void tryPresize(int size) {
+ int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
+ tableSizeFor(size + (size >>> 1) + 1);
+ int sc;
+ while ((sc = sizeCtl) >= 0) {
+ Node<K,V>[] tab = table; int n;
+ if (tab == null || (n = tab.length) == 0) {
+ n = (sc > c) ? sc : c;
+ if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
+ try {
+ if (table == tab) {
+ @SuppressWarnings("unchecked")
+ Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
+ table = nt;
+ sc = n - (n >>> 2);
+ }
+ } finally {
+ sizeCtl = sc;
+ }
+ }
+ }
+ else if (c <= sc || n >= MAXIMUM_CAPACITY)
+ break;
+ else if (tab == table) {
+ int rs = resizeStamp(n);
+ if (U.compareAndSetInt(this, SIZECTL, sc,
+ (rs << RESIZE_STAMP_SHIFT) + 2))
+ transfer(tab, null);
+ }
+ }
+ }
+
+ /**
+ * Moves and/or copies the nodes in each bin to new table. See
+ * above for explanation.
+ */
+ private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
+ int n = tab.length, stride;
+ if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
+ stride = MIN_TRANSFER_STRIDE; // subdivide range
+ if (nextTab == null) { // initiating
+ try {
+ @SuppressWarnings("unchecked")
+ Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
+ nextTab = nt;
+ } catch (Throwable ex) { // try to cope with OOME
+ sizeCtl = Integer.MAX_VALUE;
+ return;
+ }
+ nextTable = nextTab;
+ transferIndex = n;
+ }
+ int nextn = nextTab.length;
+ ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
+ boolean advance = true;
+ boolean finishing = false; // to ensure sweep before committing nextTab
+ for (int i = 0, bound = 0;;) {
+ Node<K,V> f; int fh;
+ while (advance) {
+ int nextIndex, nextBound;
+ if (--i >= bound || finishing)
+ advance = false;
+ else if ((nextIndex = transferIndex) <= 0) {
+ i = -1;
+ advance = false;
+ }
+ else if (U.compareAndSetInt
+ (this, TRANSFERINDEX, nextIndex,
+ nextBound = (nextIndex > stride ?
+ nextIndex - stride : 0))) {
+ bound = nextBound;
+ i = nextIndex - 1;
+ advance = false;
+ }
+ }
+ if (i < 0 || i >= n || i + n >= nextn) {
+ int sc;
+ if (finishing) {
+ nextTable = null;
+ table = nextTab;
+ sizeCtl = (n << 1) - (n >>> 1);
+ return;
+ }
+ if (U.compareAndSetInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
+ if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
+ return;
+ finishing = advance = true;
+ i = n; // recheck before commit
+ }
+ }
+ else if ((f = tabAt(tab, i)) == null)
+ advance = casTabAt(tab, i, null, fwd);
+ else if ((fh = f.hash) == MOVED)
+ advance = true; // already processed
+ else {
+ synchronized (f) {
+ if (tabAt(tab, i) == f) {
+ Node<K,V> ln, hn;
+ if (fh >= 0) {
+ int runBit = fh & n;
+ Node<K,V> lastRun = f;
+ for (Node<K,V> p = f.next; p != null; p = p.next) {
+ int b = p.hash & n;
+ if (b != runBit) {
+ runBit = b;
+ lastRun = p;
+ }
+ }
+ if (runBit == 0) {
+ ln = lastRun;
+ hn = null;
+ }
+ else {
+ hn = lastRun;
+ ln = null;
+ }
+ for (Node<K,V> p = f; p != lastRun; p = p.next) {
+ int ph = p.hash; K pk = p.key; V pv = p.val;
+ if ((ph & n) == 0)
+ ln = new Node<K,V>(ph, pk, pv, ln);
+ else
+ hn = new Node<K,V>(ph, pk, pv, hn);
+ }
+ setTabAt(nextTab, i, ln);
+ setTabAt(nextTab, i + n, hn);
+ setTabAt(tab, i, fwd);
+ advance = true;
+ }
+ else if (f instanceof TreeBin) {
+ TreeBin<K,V> t = (TreeBin<K,V>)f;
+ TreeNode<K,V> lo = null, loTail = null;
+ TreeNode<K,V> hi = null, hiTail = null;
+ int lc = 0, hc = 0;
+ for (Node<K,V> e = t.first; e != null; e = e.next) {
+ int h = e.hash;
+ TreeNode<K,V> p = new TreeNode<K,V>
+ (h, e.key, e.val, null, null);
+ if ((h & n) == 0) {
+ if ((p.prev = loTail) == null)
+ lo = p;
+ else
+ loTail.next = p;
+ loTail = p;
+ ++lc;
+ }
+ else {
+ if ((p.prev = hiTail) == null)
+ hi = p;
+ else
+ hiTail.next = p;
+ hiTail = p;
+ ++hc;
+ }
+ }
+ ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
+ (hc != 0) ? new TreeBin<K,V>(lo) : t;
+ hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
+ (lc != 0) ? new TreeBin<K,V>(hi) : t;
+ setTabAt(nextTab, i, ln);
+ setTabAt(nextTab, i + n, hn);
+ setTabAt(tab, i, fwd);
+ advance = true;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /* ---------------- Counter support -------------- */
+
+ /**
+ * A padded cell for distributing counts. Adapted from LongAdder
+ * and Striped64. See their internal docs for explanation.
+ */
+ @jdk.internal.vm.annotation.Contended static final class CounterCell {
+ volatile long value;
+ CounterCell(long x) { value = x; }
+ }
+
+ final long sumCount() {
+ CounterCell[] as = counterCells; CounterCell a;
+ long sum = baseCount;
+ if (as != null) {
+ for (int i = 0; i < as.length; ++i) {
+ if ((a = as[i]) != null)
+ sum += a.value;
+ }
+ }
+ return sum;
+ }
+
+ // See LongAdder version for explanation
+ private final void fullAddCount(long x, boolean wasUncontended) {
+ int h;
+ if ((h = ThreadLocalRandom.getProbe()) == 0) {
+ ThreadLocalRandom.localInit(); // force initialization
+ h = ThreadLocalRandom.getProbe();
+ wasUncontended = true;
+ }
+ boolean collide = false; // True if last slot nonempty
+ for (;;) {
+ CounterCell[] as; CounterCell a; int n; long v;
+ if ((as = counterCells) != null && (n = as.length) > 0) {
+ if ((a = as[(n - 1) & h]) == null) {
+ if (cellsBusy == 0) { // Try to attach new Cell
+ CounterCell r = new CounterCell(x); // Optimistic create
+ if (cellsBusy == 0 &&
+ U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
+ boolean created = false;
+ try { // Recheck under lock
+ CounterCell[] rs; int m, j;
+ if ((rs = counterCells) != null &&
+ (m = rs.length) > 0 &&
+ rs[j = (m - 1) & h] == null) {
+ rs[j] = r;
+ created = true;
+ }
+ } finally {
+ cellsBusy = 0;
+ }
+ if (created)
+ break;
+ continue; // Slot is now non-empty
+ }
+ }
+ collide = false;
+ }
+ else if (!wasUncontended) // CAS already known to fail
+ wasUncontended = true; // Continue after rehash
+ else if (U.compareAndSetLong(a, CELLVALUE, v = a.value, v + x))
+ break;
+ else if (counterCells != as || n >= NCPU)
+ collide = false; // At max size or stale
+ else if (!collide)
+ collide = true;
+ else if (cellsBusy == 0 &&
+ U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
+ try {
+ if (counterCells == as) {// Expand table unless stale
+ CounterCell[] rs = new CounterCell[n << 1];
+ for (int i = 0; i < n; ++i)
+ rs[i] = as[i];
+ counterCells = rs;
+ }
+ } finally {
+ cellsBusy = 0;
+ }
+ collide = false;
+ continue; // Retry with expanded table
+ }
+ h = ThreadLocalRandom.advanceProbe(h);
+ }
+ else if (cellsBusy == 0 && counterCells == as &&
+ U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
+ boolean init = false;
+ try { // Initialize table
+ if (counterCells == as) {
+ CounterCell[] rs = new CounterCell[2];
+ rs[h & 1] = new CounterCell(x);
+ counterCells = rs;
+ init = true;
+ }
+ } finally {
+ cellsBusy = 0;
+ }
+ if (init)
+ break;
+ }
+ else if (U.compareAndSetLong(this, BASECOUNT, v = baseCount, v + x))
+ break; // Fall back on using base
+ }
+ }
+
+ /* ---------------- Conversion from/to TreeBins -------------- */
+
+ /**
+ * Replaces all linked nodes in bin at given index unless table is
+ * too small, in which case resizes instead.
+ */
+ private final void treeifyBin(Node<K,V>[] tab, int index) {
+ Node<K,V> b; int n;
+ if (tab != null) {
+ if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
+ tryPresize(n << 1);
+ else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
+ synchronized (b) {
+ if (tabAt(tab, index) == b) {
+ TreeNode<K,V> hd = null, tl = null;
+ for (Node<K,V> e = b; e != null; e = e.next) {
+ TreeNode<K,V> p =
+ new TreeNode<K,V>(e.hash, e.key, e.val,
+ null, null);
+ if ((p.prev = tl) == null)
+ hd = p;
+ else
+ tl.next = p;
+ tl = p;
+ }
+ setTabAt(tab, index, new TreeBin<K,V>(hd));
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Returns a list of non-TreeNodes replacing those in given list.
+ */
+ static <K,V> Node<K,V> untreeify(Node<K,V> b) {
+ Node<K,V> hd = null, tl = null;
+ for (Node<K,V> q = b; q != null; q = q.next) {
+ Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
+ if (tl == null)
+ hd = p;
+ else
+ tl.next = p;
+ tl = p;
+ }
+ return hd;
+ }
+
+ /* ---------------- TreeNodes -------------- */
+
+ /**
+ * Nodes for use in TreeBins.
+ */
+ static final class TreeNode<K,V> extends Node<K,V> {
+ TreeNode<K,V> parent; // red-black tree links
+ TreeNode<K,V> left;
+ TreeNode<K,V> right;
+ TreeNode<K,V> prev; // needed to unlink next upon deletion
+ boolean red;
+
+ TreeNode(int hash, K key, V val, Node<K,V> next,
+ TreeNode<K,V> parent) {
+ super(hash, key, val, next);
+ this.parent = parent;
+ }
+
+ Node<K,V> find(int h, Object k) {
+ return findTreeNode(h, k, null);
+ }
+
+ /**
+ * Returns the TreeNode (or null if not found) for the given key
+ * starting at given root.
+ */
+ final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
+ if (k != null) {
+ TreeNode<K,V> p = this;
+ do {
+ int ph, dir; K pk; TreeNode<K,V> q;
+ TreeNode<K,V> pl = p.left, pr = p.right;
+ if ((ph = p.hash) > h)
+ p = pl;
+ else if (ph < h)
+ p = pr;
+ else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
+ return p;
+ else if (pl == null)
+ p = pr;
+ else if (pr == null)
+ p = pl;
+ else if ((kc != null ||
+ (kc = comparableClassFor(k)) != null) &&
+ (dir = compareComparables(kc, k, pk)) != 0)
+ p = (dir < 0) ? pl : pr;
+ else if ((q = pr.findTreeNode(h, k, kc)) != null)
+ return q;
+ else
+ p = pl;
+ } while (p != null);
+ }
+ return null;
+ }
+ }
+
+ /* ---------------- TreeBins -------------- */
+
+ /**
+ * TreeNodes used at the heads of bins. TreeBins do not hold user
+ * keys or values, but instead point to list of TreeNodes and
+ * their root. They also maintain a parasitic read-write lock
+ * forcing writers (who hold bin lock) to wait for readers (who do
+ * not) to complete before tree restructuring operations.
+ */
+ static final class TreeBin<K,V> extends Node<K,V> {
+ TreeNode<K,V> root;
+ volatile TreeNode<K,V> first;
+ volatile Thread waiter;
+ volatile int lockState;
+ // values for lockState
+ static final int WRITER = 1; // set while holding write lock
+ static final int WAITER = 2; // set when waiting for write lock
+ static final int READER = 4; // increment value for setting read lock
+
+ /**
+ * Tie-breaking utility for ordering insertions when equal
+ * hashCodes and non-comparable. We don't require a total
+ * order, just a consistent insertion rule to maintain
+ * equivalence across rebalancings. Tie-breaking further than
+ * necessary simplifies testing a bit.
+ */
+ static int tieBreakOrder(Object a, Object b) {
+ int d;
+ if (a == null || b == null ||
+ (d = a.getClass().getName().
+ compareTo(b.getClass().getName())) == 0)
+ d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
+ -1 : 1);
+ return d;
+ }
+
+ /**
+ * Creates bin with initial set of nodes headed by b.
+ */
+ TreeBin(TreeNode<K,V> b) {
+ super(TREEBIN, null, null);
+ this.first = b;
+ TreeNode<K,V> r = null;
+ for (TreeNode<K,V> x = b, next; x != null; x = next) {
+ next = (TreeNode<K,V>)x.next;
+ x.left = x.right = null;
+ if (r == null) {
+ x.parent = null;
+ x.red = false;
+ r = x;
+ }
+ else {
+ K k = x.key;
+ int h = x.hash;
+ Class<?> kc = null;
+ for (TreeNode<K,V> p = r;;) {
+ int dir, ph;
+ K pk = p.key;
+ if ((ph = p.hash) > h)
+ dir = -1;
+ else if (ph < h)
+ dir = 1;
+ else if ((kc == null &&
+ (kc = comparableClassFor(k)) == null) ||
+ (dir = compareComparables(kc, k, pk)) == 0)
+ dir = tieBreakOrder(k, pk);
+ TreeNode<K,V> xp = p;
+ if ((p = (dir <= 0) ? p.left : p.right) == null) {
+ x.parent = xp;
+ if (dir <= 0)
+ xp.left = x;
+ else
+ xp.right = x;
+ r = balanceInsertion(r, x);
+ break;
+ }
+ }
+ }
+ }
+ this.root = r;
+ assert checkInvariants(root);
+ }
+
+ /**
+ * Acquires write lock for tree restructuring.
+ */
+ private final void lockRoot() {
+ if (!U.compareAndSetInt(this, LOCKSTATE, 0, WRITER))
+ contendedLock(); // offload to separate method
+ }
+
+ /**
+ * Releases write lock for tree restructuring.
+ */
+ private final void unlockRoot() {
+ lockState = 0;
+ }
+
+ /**
+ * Possibly blocks awaiting root lock.
+ */
+ private final void contendedLock() {
+ boolean waiting = false;
+ for (int s;;) {
+ if (((s = lockState) & ~WAITER) == 0) {
+ if (U.compareAndSetInt(this, LOCKSTATE, s, WRITER)) {
+ if (waiting)
+ waiter = null;
+ return;
+ }
+ }
+ else if ((s & WAITER) == 0) {
+ if (U.compareAndSetInt(this, LOCKSTATE, s, s | WAITER)) {
+ waiting = true;
+ waiter = Thread.currentThread();
+ }
+ }
+ else if (waiting)
+ LockSupport.park(this);
+ }
+ }
+
+ /**
+ * Returns matching node or null if none. Tries to search
+ * using tree comparisons from root, but continues linear
+ * search when lock not available.
+ */
+ final Node<K,V> find(int h, Object k) {
+ if (k != null) {
+ for (Node<K,V> e = first; e != null; ) {
+ int s; K ek;
+ if (((s = lockState) & (WAITER|WRITER)) != 0) {
+ if (e.hash == h &&
+ ((ek = e.key) == k || (ek != null && k.equals(ek))))
+ return e;
+ e = e.next;
+ }
+ else if (U.compareAndSetInt(this, LOCKSTATE, s,
+ s + READER)) {
+ TreeNode<K,V> r, p;
+ try {
+ p = ((r = root) == null ? null :
+ r.findTreeNode(h, k, null));
+ } finally {
+ Thread w;
+ if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
+ (READER|WAITER) && (w = waiter) != null)
+ LockSupport.unpark(w);
+ }
+ return p;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Finds or adds a node.
+ * @return null if added
+ */
+ final TreeNode<K,V> putTreeVal(int h, K k, V v) {
+ Class<?> kc = null;
+ boolean searched = false;
+ for (TreeNode<K,V> p = root;;) {
+ int dir, ph; K pk;
+ if (p == null) {
+ first = root = new TreeNode<K,V>(h, k, v, null, null);
+ break;
+ }
+ else if ((ph = p.hash) > h)
+ dir = -1;
+ else if (ph < h)
+ dir = 1;
+ else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
+ return p;
+ else if ((kc == null &&
+ (kc = comparableClassFor(k)) == null) ||
+ (dir = compareComparables(kc, k, pk)) == 0) {
+ if (!searched) {
+ TreeNode<K,V> q, ch;
+ searched = true;
+ if (((ch = p.left) != null &&
+ (q = ch.findTreeNode(h, k, kc)) != null) ||
+ ((ch = p.right) != null &&
+ (q = ch.findTreeNode(h, k, kc)) != null))
+ return q;
+ }
+ dir = tieBreakOrder(k, pk);
+ }
+
+ TreeNode<K,V> xp = p;
+ if ((p = (dir <= 0) ? p.left : p.right) == null) {
+ TreeNode<K,V> x, f = first;
+ first = x = new TreeNode<K,V>(h, k, v, f, xp);
+ if (f != null)
+ f.prev = x;
+ if (dir <= 0)
+ xp.left = x;
+ else
+ xp.right = x;
+ if (!xp.red)
+ x.red = true;
+ else {
+ lockRoot();
+ try {
+ root = balanceInsertion(root, x);
+ } finally {
+ unlockRoot();
+ }
+ }
+ break;
+ }
+ }
+ assert checkInvariants(root);
+ 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.
+ *
+ * @return true if now too small, so should be untreeified
+ */
+ final boolean removeTreeNode(TreeNode<K,V> p) {
+ TreeNode<K,V> next = (TreeNode<K,V>)p.next;
+ TreeNode<K,V> pred = p.prev; // unlink traversal pointers
+ TreeNode<K,V> r, rl;
+ if (pred == null)
+ first = next;
+ else
+ pred.next = next;
+ if (next != null)
+ next.prev = pred;
+ if (first == null) {
+ root = null;
+ return true;
+ }
+ if ((r = root) == null || r.right == null || // too small
+ (rl = r.left) == null || rl.left == null)
+ return true;
+ lockRoot();
+ try {
+ TreeNode<K,V> replacement;
+ TreeNode<K,V> pl = p.left;
+ TreeNode<K,V> pr = p.right;
+ if (pl != null && pr != null) {
+ TreeNode<K,V> 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<K,V> sr = s.right;
+ TreeNode<K,V> pp = p.parent;
+ if (s == pr) { // p was s's direct parent
+ p.parent = s;
+ s.right = p;
+ }
+ else {
+ TreeNode<K,V> 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)
+ r = s;
+ else if (p == pp.left)
+ pp.left = s;
+ else
+ pp.right = s;
+ if (sr != null)
+ replacement = sr;
+ else
+ replacement = p;
+ }
+ else if (pl != null)
+ replacement = pl;
+ else if (pr != null)
+ replacement = pr;
+ else
+ replacement = p;
+ if (replacement != p) {
+ TreeNode<K,V> pp = replacement.parent = p.parent;
+ if (pp == null)
+ r = replacement;
+ else if (p == pp.left)
+ pp.left = replacement;
+ else
+ pp.right = replacement;
+ p.left = p.right = p.parent = null;
+ }
+
+ root = (p.red) ? r : balanceDeletion(r, replacement);
+
+ if (p == replacement) { // detach pointers
+ TreeNode<K,V> pp;
+ if ((pp = p.parent) != null) {
+ if (p == pp.left)
+ pp.left = null;
+ else if (p == pp.right)
+ pp.right = null;
+ p.parent = null;
+ }
+ }
+ } finally {
+ unlockRoot();
+ }
+ assert checkInvariants(root);
+ return false;
+ }
+
+ /* ------------------------------------------------------------ */
+ // Red-black tree methods, all adapted from CLR
+
+ static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
+ TreeNode<K,V> p) {
+ TreeNode<K,V> r, pp, rl;
+ if (p != null && (r = p.right) != null) {
+ if ((rl = p.right = r.left) != null)
+ rl.parent = p;
+ if ((pp = r.parent = p.parent) == null)
+ (root = r).red = false;
+ else if (pp.left == p)
+ pp.left = r;
+ else
+ pp.right = r;
+ r.left = p;
+ p.parent = r;
+ }
+ return root;
+ }
+
+ static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
+ TreeNode<K,V> p) {
+ TreeNode<K,V> l, pp, lr;
+ if (p != null && (l = p.left) != null) {
+ if ((lr = p.left = l.right) != null)
+ lr.parent = p;
+ if ((pp = l.parent = p.parent) == null)
+ (root = l).red = false;
+ else if (pp.right == p)
+ pp.right = l;
+ else
+ pp.left = l;
+ l.right = p;
+ p.parent = l;
+ }
+ return root;
+ }
+
+ static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
+ TreeNode<K,V> x) {
+ x.red = true;
+ for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
+ if ((xp = x.parent) == null) {
+ x.red = false;
+ return x;
+ }
+ else if (!xp.red || (xpp = xp.parent) == null)
+ return root;
+ if (xp == (xppl = xpp.left)) {
+ if ((xppr = xpp.right) != null && xppr.red) {
+ xppr.red = false;
+ xp.red = false;
+ xpp.red = true;
+ x = xpp;
+ }
+ else {
+ if (x == xp.right) {
+ root = rotateLeft(root, x = xp);
+ xpp = (xp = x.parent) == null ? null : xp.parent;
+ }
+ if (xp != null) {
+ xp.red = false;
+ if (xpp != null) {
+ xpp.red = true;
+ root = rotateRight(root, xpp);
+ }
+ }
+ }
+ }
+ else {
+ if (xppl != null && xppl.red) {
+ xppl.red = false;
+ xp.red = false;
+ xpp.red = true;
+ x = xpp;
+ }
+ else {
+ if (x == xp.left) {
+ root = rotateRight(root, x = xp);
+ xpp = (xp = x.parent) == null ? null : xp.parent;
+ }
+ if (xp != null) {
+ xp.red = false;
+ if (xpp != null) {
+ xpp.red = true;
+ root = rotateLeft(root, xpp);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
+ TreeNode<K,V> x) {
+ for (TreeNode<K,V> xp, xpl, xpr;;) {
+ if (x == null || x == root)
+ return root;
+ else if ((xp = x.parent) == null) {
+ x.red = false;
+ return x;
+ }
+ else if (x.red) {
+ x.red = false;
+ return root;
+ }
+ else if ((xpl = xp.left) == x) {
+ if ((xpr = xp.right) != null && xpr.red) {
+ xpr.red = false;
+ xp.red = true;
+ root = rotateLeft(root, xp);
+ xpr = (xp = x.parent) == null ? null : xp.right;
+ }
+ if (xpr == null)
+ x = xp;
+ else {
+ TreeNode<K,V> sl = xpr.left, sr = xpr.right;
+ if ((sr == null || !sr.red) &&
+ (sl == null || !sl.red)) {
+ xpr.red = true;
+ x = xp;
+ }
+ else {
+ if (sr == null || !sr.red) {
+ if (sl != null)
+ sl.red = false;
+ xpr.red = true;
+ root = rotateRight(root, xpr);
+ xpr = (xp = x.parent) == null ?
+ null : xp.right;
+ }
+ if (xpr != null) {
+ xpr.red = (xp == null) ? false : xp.red;
+ if ((sr = xpr.right) != null)
+ sr.red = false;
+ }
+ if (xp != null) {
+ xp.red = false;
+ root = rotateLeft(root, xp);
+ }
+ x = root;
+ }
+ }
+ }
+ else { // symmetric
+ if (xpl != null && xpl.red) {
+ xpl.red = false;
+ xp.red = true;
+ root = rotateRight(root, xp);
+ xpl = (xp = x.parent) == null ? null : xp.left;
+ }
+ if (xpl == null)
+ x = xp;
+ else {
+ TreeNode<K,V> sl = xpl.left, sr = xpl.right;
+ if ((sl == null || !sl.red) &&
+ (sr == null || !sr.red)) {
+ xpl.red = true;
+ x = xp;
+ }
+ else {
+ if (sl == null || !sl.red) {
+ if (sr != null)
+ sr.red = false;
+ xpl.red = true;
+ root = rotateLeft(root, xpl);
+ xpl = (xp = x.parent) == null ?
+ null : xp.left;
+ }
+ if (xpl != null) {
+ xpl.red = (xp == null) ? false : xp.red;
+ if ((sl = xpl.left) != null)
+ sl.red = false;
+ }
+ if (xp != null) {
+ xp.red = false;
+ root = rotateRight(root, xp);
+ }
+ x = root;
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Checks invariants recursively for the tree of Nodes rooted at t.
+ */
+ static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
+ TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
+ tb = t.prev, tn = (TreeNode<K,V>)t.next;
+ if (tb != null && tb.next != t)
+ return false;
+ if (tn != null && tn.prev != t)
+ return false;
+ if (tp != null && t != tp.left && t != tp.right)
+ return false;
+ if (tl != null && (tl.parent != t || tl.hash > t.hash))
+ return false;
+ if (tr != null && (tr.parent != t || tr.hash < t.hash))
+ return false;
+ if (t.red && tl != null && tl.red && tr != null && tr.red)
+ return false;
+ if (tl != null && !checkInvariants(tl))
+ return false;
+ if (tr != null && !checkInvariants(tr))
+ return false;
+ return true;
+ }
+
+ private static final Unsafe U = Unsafe.getUnsafe();
+ private static final long LOCKSTATE
+ = U.objectFieldOffset(TreeBin.class, "lockState");
+ }
+
+ /* ----------------Table Traversal -------------- */
+
+ /**
+ * Records the table, its length, and current traversal index for a
+ * traverser that must process a region of a forwarded table before
+ * proceeding with current table.
+ */
+ static final class TableStack<K,V> {
+ int length;
+ int index;
+ Node<K,V>[] tab;
+ TableStack<K,V> next;
+ }
+
+ /**
+ * Encapsulates traversal for methods such as containsValue; also
+ * serves as a base class for other iterators and spliterators.
+ *
+ * Method advance visits once each still-valid node that was
+ * reachable upon iterator construction. It might miss some that
+ * were added to a bin after the bin was visited, which is OK wrt
+ * consistency guarantees. Maintaining this property in the face
+ * of possible ongoing resizes requires a fair amount of
+ * bookkeeping state that is difficult to optimize away amidst
+ * volatile accesses. Even so, traversal maintains reasonable
+ * throughput.
+ *
+ * Normally, iteration proceeds bin-by-bin traversing lists.
+ * However, if the table has been resized, then all future steps
+ * must traverse both the bin at the current index as well as at
+ * (index + baseSize); and so on for further resizings. To
+ * paranoically cope with potential sharing by users of iterators
+ * across threads, iteration terminates if a bounds checks fails
+ * for a table read.
+ */
+ static class Traverser<K,V> {
+ Node<K,V>[] tab; // current table; updated if resized
+ Node<K,V> next; // the next entry to use
+ TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
+ int index; // index of bin to use next
+ int baseIndex; // current index of initial table
+ int baseLimit; // index bound for initial table
+ final int baseSize; // initial table size
+
+ Traverser(Node<K,V>[] tab, int size, int index, int limit) {
+ this.tab = tab;
+ this.baseSize = size;
+ this.baseIndex = this.index = index;
+ this.baseLimit = limit;
+ this.next = null;
+ }
+
+ /**
+ * Advances if possible, returning next valid node, or null if none.
+ */
+ final Node<K,V> advance() {
+ Node<K,V> e;
+ if ((e = next) != null)
+ e = e.next;
+ for (;;) {
+ Node<K,V>[] t; int i, n; // must use locals in checks
+ if (e != null)
+ return next = e;
+ if (baseIndex >= baseLimit || (t = tab) == null ||
+ (n = t.length) <= (i = index) || i < 0)
+ return next = null;
+ if ((e = tabAt(t, i)) != null && e.hash < 0) {
+ if (e instanceof ForwardingNode) {
+ tab = ((ForwardingNode<K,V>)e).nextTable;
+ e = null;
+ pushState(t, i, n);
+ continue;
+ }
+ else if (e instanceof TreeBin)
+ e = ((TreeBin<K,V>)e).first;
+ else
+ e = null;
+ }
+ if (stack != null)
+ recoverState(n);
+ else if ((index = i + baseSize) >= n)
+ index = ++baseIndex; // visit upper slots if present
+ }
+ }
+
+ /**
+ * Saves traversal state upon encountering a forwarding node.
+ */
+ private void pushState(Node<K,V>[] t, int i, int n) {
+ TableStack<K,V> s = spare; // reuse if possible
+ if (s != null)
+ spare = s.next;
+ else
+ s = new TableStack<K,V>();
+ s.tab = t;
+ s.length = n;
+ s.index = i;
+ s.next = stack;
+ stack = s;
+ }
+
+ /**
+ * Possibly pops traversal state.
+ *
+ * @param n length of current table
+ */
+ private void recoverState(int n) {
+ TableStack<K,V> s; int len;
+ while ((s = stack) != null && (index += (len = s.length)) >= n) {
+ n = len;
+ index = s.index;
+ tab = s.tab;
+ s.tab = null;
+ TableStack<K,V> next = s.next;
+ s.next = spare; // save for reuse
+ stack = next;
+ spare = s;
+ }
+ if (s == null && (index += baseSize) >= n)
+ index = ++baseIndex;
+ }
+ }
+
+ /**
+ * Base of key, value, and entry Iterators. Adds fields to
+ * Traverser to support iterator.remove.
+ */
+ static class BaseIterator<K,V> extends Traverser<K,V> {
+ final ConcurrentHashMap<K,V> map;
+ Node<K,V> lastReturned;
+ BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
+ ConcurrentHashMap<K,V> map) {
+ super(tab, size, index, limit);
+ this.map = map;
+ advance();
+ }
+
+ public final boolean hasNext() { return next != null; }
+ public final boolean hasMoreElements() { return next != null; }
+
+ public final void remove() {
+ Node<K,V> p;
+ if ((p = lastReturned) == null)
+ throw new IllegalStateException();
+ lastReturned = null;
+ map.replaceNode(p.key, null, null);
+ }
+ }
+
+ static final class KeyIterator<K,V> extends BaseIterator<K,V>
+ implements Iterator<K>, Enumeration<K> {
+ KeyIterator(Node<K,V>[] tab, int size, int index, int limit,
+ ConcurrentHashMap<K,V> map) {
+ super(tab, size, index, limit, map);
+ }
+
+ public final K next() {
+ Node<K,V> p;
+ if ((p = next) == null)
+ throw new NoSuchElementException();
+ K k = p.key;
+ lastReturned = p;
+ advance();
+ return k;
+ }
+
+ public final K nextElement() { return next(); }
+ }
+
+ static final class ValueIterator<K,V> extends BaseIterator<K,V>
+ implements Iterator<V>, Enumeration<V> {
+ ValueIterator(Node<K,V>[] tab, int size, int index, int limit,
+ ConcurrentHashMap<K,V> map) {
+ super(tab, size, index, limit, map);
+ }
+
+ public final V next() {
+ Node<K,V> p;
+ if ((p = next) == null)
+ throw new NoSuchElementException();
+ V v = p.val;
+ lastReturned = p;
+ advance();
+ return v;
+ }
+
+ public final V nextElement() { return next(); }
+ }
+
+ static final class EntryIterator<K,V> extends BaseIterator<K,V>
+ implements Iterator<Map.Entry<K,V>> {
+ EntryIterator(Node<K,V>[] tab, int size, int index, int limit,
+ ConcurrentHashMap<K,V> map) {
+ super(tab, size, index, limit, map);
+ }
+
+ public final Map.Entry<K,V> next() {
+ Node<K,V> p;
+ if ((p = next) == null)
+ throw new NoSuchElementException();
+ K k = p.key;
+ V v = p.val;
+ lastReturned = p;
+ advance();
+ return new MapEntry<K,V>(k, v, map);
+ }
+ }
+
+ /**
+ * Exported Entry for EntryIterator.
+ */
+ static final class MapEntry<K,V> implements Map.Entry<K,V> {
+ final K key; // non-null
+ V val; // non-null
+ final ConcurrentHashMap<K,V> map;
+ MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
+ this.key = key;
+ this.val = val;
+ this.map = map;
+ }
+ public K getKey() { return key; }
+ public V getValue() { return val; }
+ public int hashCode() { return key.hashCode() ^ val.hashCode(); }
+ public String toString() {
+ return Helpers.mapEntryToString(key, val);
+ }
+
+ public boolean equals(Object o) {
+ Object k, v; Map.Entry<?,?> e;
+ return ((o instanceof Map.Entry) &&
+ (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
+ (v = e.getValue()) != null &&
+ (k == key || k.equals(key)) &&
+ (v == val || v.equals(val)));
+ }
+
+ /**
+ * Sets our entry's value and writes through to the map. The
+ * 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 V setValue(V value) {
+ if (value == null) throw new NullPointerException();
+ V v = val;
+ val = value;
+ map.put(key, value);
+ return v;
+ }
+ }
+
+ static final class KeySpliterator<K,V> extends Traverser<K,V>
+ implements Spliterator<K> {
+ long est; // size estimate
+ KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
+ long est) {
+ super(tab, size, index, limit);
+ this.est = est;
+ }
+
+ public KeySpliterator<K,V> trySplit() {
+ int i, f, h;
+ return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
+ new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
+ f, est >>>= 1);
+ }
+
+ public void forEachRemaining(Consumer<? super K> action) {
+ if (action == null) throw new NullPointerException();
+ for (Node<K,V> p; (p = advance()) != null;)
+ action.accept(p.key);
+ }
+
+ public boolean tryAdvance(Consumer<? super K> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V> p;
+ if ((p = advance()) == null)
+ return false;
+ action.accept(p.key);
+ return true;
+ }
+
+ public long estimateSize() { return est; }
+
+ public int characteristics() {
+ return Spliterator.DISTINCT | Spliterator.CONCURRENT |
+ Spliterator.NONNULL;
+ }
+ }
+
+ static final class ValueSpliterator<K,V> extends Traverser<K,V>
+ implements Spliterator<V> {
+ long est; // size estimate
+ ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
+ long est) {
+ super(tab, size, index, limit);
+ this.est = est;
+ }
+
+ public ValueSpliterator<K,V> trySplit() {
+ int i, f, h;
+ return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
+ new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
+ f, est >>>= 1);
+ }
+
+ public void forEachRemaining(Consumer<? super V> action) {
+ if (action == null) throw new NullPointerException();
+ for (Node<K,V> p; (p = advance()) != null;)
+ action.accept(p.val);
+ }
+
+ public boolean tryAdvance(Consumer<? super V> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V> p;
+ if ((p = advance()) == null)
+ return false;
+ action.accept(p.val);
+ return true;
+ }
+
+ public long estimateSize() { return est; }
+
+ public int characteristics() {
+ return Spliterator.CONCURRENT | Spliterator.NONNULL;
+ }
+ }
+
+ static final class EntrySpliterator<K,V> extends Traverser<K,V>
+ implements Spliterator<Map.Entry<K,V>> {
+ final ConcurrentHashMap<K,V> map; // To export MapEntry
+ long est; // size estimate
+ EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
+ long est, ConcurrentHashMap<K,V> map) {
+ super(tab, size, index, limit);
+ this.map = map;
+ this.est = est;
+ }
+
+ public EntrySpliterator<K,V> trySplit() {
+ int i, f, h;
+ return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
+ new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
+ f, est >>>= 1, map);
+ }
+
+ public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
+ if (action == null) throw new NullPointerException();
+ for (Node<K,V> p; (p = advance()) != null; )
+ action.accept(new MapEntry<K,V>(p.key, p.val, map));
+ }
+
+ public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V> p;
+ if ((p = advance()) == null)
+ return false;
+ action.accept(new MapEntry<K,V>(p.key, p.val, map));
+ return true;
+ }
+
+ public long estimateSize() { return est; }
+
+ public int characteristics() {
+ return Spliterator.DISTINCT | Spliterator.CONCURRENT |
+ Spliterator.NONNULL;
+ }
+ }
+
+ // Parallel bulk operations
+
+ /**
+ * Computes initial batch value for bulk tasks. The returned value
+ * is approximately 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 batchFor(long b) {
+ long n;
+ if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
+ return 0;
+ int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
+ return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
+ }
+
+ /**
+ * Performs the given action for each (key, value).
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param action the action
+ * @since 1.8
+ */
+ public void forEach(long parallelismThreshold,
+ BiConsumer<? super K,? super V> action) {
+ if (action == null) throw new NullPointerException();
+ new ForEachMappingTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ action).invoke();
+ }
+
+ /**
+ * Performs the given action for each non-null transformation
+ * of each (key, value).
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @since 1.8
+ */
+ public <U> void forEach(long parallelismThreshold,
+ BiFunction<? super K, ? super V, ? extends U> transformer,
+ Consumer<? super U> action) {
+ if (transformer == null || action == null)
+ throw new NullPointerException();
+ new ForEachTransformedMappingTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param searchFunction a function returning a non-null
+ * result on success, else null
+ * @param <U> the return type of the search function
+ * @return a non-null result from applying the given search
+ * function on each (key, value), or null if none
+ * @since 1.8
+ */
+ public <U> U search(long parallelismThreshold,
+ BiFunction<? super K, ? super V, ? extends U> searchFunction) {
+ if (searchFunction == null) throw new NullPointerException();
+ return new SearchMappingsTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ searchFunction, new AtomicReference<U>()).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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @return the result of accumulating the given transformation
+ * of all (key, value) pairs
+ * @since 1.8
+ */
+ public <U> U reduce(long parallelismThreshold,
+ BiFunction<? super K, ? super V, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceMappingsTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public double reduceToDouble(long parallelismThreshold,
+ ToDoubleBiFunction<? super K, ? super V> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceMappingsToDoubleTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public long reduceToLong(long parallelismThreshold,
+ ToLongBiFunction<? super K, ? super V> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceMappingsToLongTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public int reduceToInt(long parallelismThreshold,
+ ToIntBiFunction<? super K, ? super V> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceMappingsToIntTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, transformer, basis, reducer).invoke();
+ }
+
+ /**
+ * Performs the given action for each key.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param action the action
+ * @since 1.8
+ */
+ public void forEachKey(long parallelismThreshold,
+ Consumer<? super K> action) {
+ if (action == null) throw new NullPointerException();
+ new ForEachKeyTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ action).invoke();
+ }
+
+ /**
+ * Performs the given action for each non-null transformation
+ * of each key.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @since 1.8
+ */
+ public <U> void forEachKey(long parallelismThreshold,
+ Function<? super K, ? extends U> transformer,
+ Consumer<? super U> action) {
+ if (transformer == null || action == null)
+ throw new NullPointerException();
+ new ForEachTransformedKeyTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param searchFunction a function returning a non-null
+ * result on success, else null
+ * @param <U> the return type of the search function
+ * @return a non-null result from applying the given search
+ * function on each key, or null if none
+ * @since 1.8
+ */
+ public <U> U searchKeys(long parallelismThreshold,
+ Function<? super K, ? extends U> searchFunction) {
+ if (searchFunction == null) throw new NullPointerException();
+ return new SearchKeysTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ searchFunction, new AtomicReference<U>()).invoke();
+ }
+
+ /**
+ * Returns the result of accumulating all keys using the given
+ * reducer to combine values, or null if none.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public K reduceKeys(long parallelismThreshold,
+ BiFunction<? super K, ? super K, ? extends K> reducer) {
+ if (reducer == null) throw new NullPointerException();
+ return new ReduceKeysTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @return the result of accumulating the given transformation
+ * of all keys
+ * @since 1.8
+ */
+ public <U> U reduceKeys(long parallelismThreshold,
+ Function<? super K, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceKeysTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public double reduceKeysToDouble(long parallelismThreshold,
+ ToDoubleFunction<? super K> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceKeysToDoubleTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public long reduceKeysToLong(long parallelismThreshold,
+ ToLongFunction<? super K> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceKeysToLongTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public int reduceKeysToInt(long parallelismThreshold,
+ ToIntFunction<? super K> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceKeysToIntTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, transformer, basis, reducer).invoke();
+ }
+
+ /**
+ * Performs the given action for each value.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param action the action
+ * @since 1.8
+ */
+ public void forEachValue(long parallelismThreshold,
+ Consumer<? super V> action) {
+ if (action == null)
+ throw new NullPointerException();
+ new ForEachValueTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ action).invoke();
+ }
+
+ /**
+ * Performs the given action for each non-null transformation
+ * of each value.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @since 1.8
+ */
+ public <U> void forEachValue(long parallelismThreshold,
+ Function<? super V, ? extends U> transformer,
+ Consumer<? super U> action) {
+ if (transformer == null || action == null)
+ throw new NullPointerException();
+ new ForEachTransformedValueTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param searchFunction a function returning a non-null
+ * result on success, else null
+ * @param <U> the return type of the search function
+ * @return a non-null result from applying the given search
+ * function on each value, or null if none
+ * @since 1.8
+ */
+ public <U> U searchValues(long parallelismThreshold,
+ Function<? super V, ? extends U> searchFunction) {
+ if (searchFunction == null) throw new NullPointerException();
+ return new SearchValuesTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ searchFunction, new AtomicReference<U>()).invoke();
+ }
+
+ /**
+ * Returns the result of accumulating all values using the
+ * given reducer to combine values, or null if none.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param reducer a commutative associative combining function
+ * @return the result of accumulating all values
+ * @since 1.8
+ */
+ public V reduceValues(long parallelismThreshold,
+ BiFunction<? super V, ? super V, ? extends V> reducer) {
+ if (reducer == null) throw new NullPointerException();
+ return new ReduceValuesTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @return the result of accumulating the given transformation
+ * of all values
+ * @since 1.8
+ */
+ public <U> U reduceValues(long parallelismThreshold,
+ Function<? super V, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceValuesTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public double reduceValuesToDouble(long parallelismThreshold,
+ ToDoubleFunction<? super V> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceValuesToDoubleTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public long reduceValuesToLong(long parallelismThreshold,
+ ToLongFunction<? super V> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceValuesToLongTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public int reduceValuesToInt(long parallelismThreshold,
+ ToIntFunction<? super V> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceValuesToIntTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, transformer, basis, reducer).invoke();
+ }
+
+ /**
+ * Performs the given action for each entry.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param action the action
+ * @since 1.8
+ */
+ public void forEachEntry(long parallelismThreshold,
+ Consumer<? super Map.Entry<K,V>> action) {
+ if (action == null) throw new NullPointerException();
+ new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
+ action).invoke();
+ }
+
+ /**
+ * Performs the given action for each non-null transformation
+ * of each entry.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @since 1.8
+ */
+ public <U> void forEachEntry(long parallelismThreshold,
+ Function<Map.Entry<K,V>, ? extends U> transformer,
+ Consumer<? super U> action) {
+ if (transformer == null || action == null)
+ throw new NullPointerException();
+ new ForEachTransformedEntryTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param searchFunction a function returning a non-null
+ * result on success, else null
+ * @param <U> the return type of the search function
+ * @return a non-null result from applying the given search
+ * function on each entry, or null if none
+ * @since 1.8
+ */
+ public <U> U searchEntries(long parallelismThreshold,
+ Function<Map.Entry<K,V>, ? extends U> searchFunction) {
+ if (searchFunction == null) throw new NullPointerException();
+ return new SearchEntriesTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ searchFunction, new AtomicReference<U>()).invoke();
+ }
+
+ /**
+ * Returns the result of accumulating all entries using the
+ * given reducer to combine values, or null if none.
+ *
+ * @param parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @param reducer a commutative associative combining function
+ * @return the result of accumulating all entries
+ * @since 1.8
+ */
+ public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
+ BiFunction<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>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @param <U> the return type of the transformer
+ * @return the result of accumulating the given transformation
+ * of all entries
+ * @since 1.8
+ */
+ public <U> U reduceEntries(long parallelismThreshold,
+ Function<Map.Entry<K,V>, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceEntriesTask<K,V,U>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public double reduceEntriesToDouble(long parallelismThreshold,
+ ToDoubleFunction<Map.Entry<K,V>> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceEntriesToDoubleTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public long reduceEntriesToLong(long parallelismThreshold,
+ ToLongFunction<Map.Entry<K,V>> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceEntriesToLongTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, 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 parallelismThreshold the (estimated) number of elements
+ * needed for this operation to be executed in parallel
+ * @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
+ * @since 1.8
+ */
+ public int reduceEntriesToInt(long parallelismThreshold,
+ ToIntFunction<Map.Entry<K,V>> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ if (transformer == null || reducer == null)
+ throw new NullPointerException();
+ return new MapReduceEntriesToIntTask<K,V>
+ (null, batchFor(parallelismThreshold), 0, 0, table,
+ null, transformer, basis, reducer).invoke();
+ }
+
+
+ /* ----------------Views -------------- */
+
+ /**
+ * Base class for views.
+ */
+ abstract static class CollectionView<K,V,E>
+ implements Collection<E>, java.io.Serializable {
+ private static final long serialVersionUID = 7249069246763182397L;
+ final ConcurrentHashMap<K,V> map;
+ CollectionView(ConcurrentHashMap<K,V> map) { this.map = map; }
+
+ /**
+ * Returns the map backing this view.
+ *
+ * @return the map backing this view
+ */
+ public ConcurrentHashMap<K,V> getMap() { return map; }
+
+ /**
+ * Removes all of the elements from this view, by removing all
+ * the mappings from the map backing this view.
+ */
+ public final void clear() { map.clear(); }
+ public final int size() { return map.size(); }
+ public final boolean isEmpty() { return map.isEmpty(); }
+
+ // implementations below rely on concrete classes supplying these
+ // abstract methods
+ /**
+ * Returns an iterator over the elements in this collection.
+ *
+ * <p>The returned iterator is
+ * <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
+ *
+ * @return an iterator over the elements in this collection
+ */
+ public abstract Iterator<E> iterator();
+ public abstract boolean contains(Object o);
+ public abstract boolean remove(Object o);
+
+ private static final String OOME_MSG = "Required array size too large";
+
+ public final Object[] toArray() {
+ long sz = map.mappingCount();
+ if (sz > MAX_ARRAY_SIZE)
+ throw new OutOfMemoryError(OOME_MSG);
+ int n = (int)sz;
+ Object[] r = new Object[n];
+ int i = 0;
+ for (E e : this) {
+ if (i == n) {
+ if (n >= MAX_ARRAY_SIZE)
+ throw new OutOfMemoryError(OOME_MSG);
+ if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
+ n = MAX_ARRAY_SIZE;
+ else
+ n += (n >>> 1) + 1;
+ r = Arrays.copyOf(r, n);
+ }
+ r[i++] = e;
+ }
+ return (i == n) ? r : Arrays.copyOf(r, i);
+ }
+
+ @SuppressWarnings("unchecked")
+ public final <T> T[] toArray(T[] a) {
+ long sz = map.mappingCount();
+ if (sz > MAX_ARRAY_SIZE)
+ throw new OutOfMemoryError(OOME_MSG);
+ int m = (int)sz;
+ T[] r = (a.length >= m) ? a :
+ (T[])java.lang.reflect.Array
+ .newInstance(a.getClass().getComponentType(), m);
+ int n = r.length;
+ int i = 0;
+ for (E e : this) {
+ if (i == n) {
+ if (n >= MAX_ARRAY_SIZE)
+ throw new OutOfMemoryError(OOME_MSG);
+ if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
+ n = MAX_ARRAY_SIZE;
+ else
+ n += (n >>> 1) + 1;
+ r = Arrays.copyOf(r, n);
+ }
+ r[i++] = (T)e;
+ }
+ if (a == r && i < n) {
+ r[i] = null; // null-terminate
+ return r;
+ }
+ return (i == n) ? r : Arrays.copyOf(r, i);
+ }
+
+ /**
+ * Returns a string representation of this collection.
+ * The string representation consists of the string representations
+ * of the collection's elements in the order they are returned by
+ * its iterator, enclosed in square brackets ({@code "[]"}).
+ * Adjacent elements are separated by the characters {@code ", "}
+ * (comma and space). Elements are converted to strings as by
+ * {@link String#valueOf(Object)}.
+ *
+ * @return a string representation of this collection
+ */
+ public final String toString() {
+ StringBuilder sb = new StringBuilder();
+ sb.append('[');
+ Iterator<E> it = iterator();
+ if (it.hasNext()) {
+ for (;;) {
+ Object e = it.next();
+ sb.append(e == this ? "(this Collection)" : e);
+ if (!it.hasNext())
+ break;
+ sb.append(',').append(' ');
+ }
+ }
+ return sb.append(']').toString();
+ }
+
+ public final boolean containsAll(Collection<?> c) {
+ if (c != this) {
+ for (Object e : c) {
+ if (e == null || !contains(e))
+ return false;
+ }
+ }
+ return true;
+ }
+
+ public boolean removeAll(Collection<?> c) {
+ if (c == null) throw new NullPointerException();
+ boolean modified = false;
+ // Use (c instanceof Set) as a hint that lookup in c is as
+ // efficient as this view
+ Node<K,V>[] t;
+ if ((t = map.table) == null) {
+ return false;
+ } else if (c instanceof Set<?> && c.size() > t.length) {
+ for (Iterator<?> it = iterator(); it.hasNext(); ) {
+ if (c.contains(it.next())) {
+ it.remove();
+ modified = true;
+ }
+ }
+ } else {
+ for (Object e : c)
+ modified |= remove(e);
+ }
+ return modified;
+ }
+
+ public final boolean retainAll(Collection<?> c) {
+ if (c == null) throw new NullPointerException();
+ boolean modified = false;
+ for (Iterator<E> it = iterator(); it.hasNext();) {
+ if (!c.contains(it.next())) {
+ it.remove();
+ modified = true;
+ }
+ }
+ return modified;
+ }
+
+ }
+
+ /**
+ * A view of a ConcurrentHashMap 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() keySet()},
+ * {@link #keySet(Object) keySet(V)},
+ * {@link #newKeySet() newKeySet()},
+ * {@link #newKeySet(int) newKeySet(int)}.
+ *
+ * @since 1.8
+ */
+ public static class KeySetView<K,V> extends CollectionView<K,V,K>
+ implements Set<K>, java.io.Serializable {
+ private static final long serialVersionUID = 7249069246763182397L;
+ private final V value;
+ KeySetView(ConcurrentHashMap<K,V> map, V value) { // non-public
+ super(map);
+ this.value = value;
+ }
+
+ /**
+ * 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; }
+
+ /**
+ * {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ */
+ public boolean contains(Object o) { return map.containsKey(o); }
+
+ /**
+ * Removes the key from this map view, by removing the key (and its
+ * corresponding value) from the backing map. This method does
+ * nothing if the key is not in the map.
+ *
+ * @param o the key to be removed from the backing map
+ * @return {@code true} if the backing map contained the specified key
+ * @throws NullPointerException if the specified key is null
+ */
+ public boolean remove(Object o) { return map.remove(o) != null; }
+
+ /**
+ * @return an iterator over the keys of the backing map
+ */
+ public Iterator<K> iterator() {
+ Node<K,V>[] t;
+ ConcurrentHashMap<K,V> m = map;
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new KeyIterator<K,V>(t, f, 0, f, m);
+ }
+
+ /**
+ * Adds the specified key to this set view by mapping the key to
+ * the default mapped value in the backing map, if defined.
+ *
+ * @param e key to be added
+ * @return {@code true} if this set changed as a result of the call
+ * @throws NullPointerException if the specified key is null
+ * @throws UnsupportedOperationException if no default mapped value
+ * for additions was provided
+ */
+ public boolean add(K e) {
+ V v;
+ if ((v = value) == null)
+ throw new UnsupportedOperationException();
+ return map.putVal(e, v, true) == null;
+ }
+
+ /**
+ * Adds all of the elements in the specified collection to this set,
+ * as if by calling {@link #add} on each one.
+ *
+ * @param c the elements to be inserted into this set
+ * @return {@code true} if this set changed as a result of the call
+ * @throws NullPointerException if the collection or any of its
+ * elements are {@code null}
+ * @throws UnsupportedOperationException if no default mapped value
+ * for additions was provided
+ */
+ public boolean addAll(Collection<? extends K> c) {
+ boolean added = false;
+ V v;
+ if ((v = value) == null)
+ throw new UnsupportedOperationException();
+ for (K e : c) {
+ if (map.putVal(e, v, true) == null)
+ added = true;
+ }
+ return added;
+ }
+
+ public int hashCode() {
+ int h = 0;
+ for (K e : this)
+ h += e.hashCode();
+ return h;
+ }
+
+ public boolean equals(Object o) {
+ Set<?> c;
+ return ((o instanceof Set) &&
+ ((c = (Set<?>)o) == this ||
+ (containsAll(c) && c.containsAll(this))));
+ }
+
+ public Spliterator<K> spliterator() {
+ Node<K,V>[] t;
+ ConcurrentHashMap<K,V> m = map;
+ long n = m.sumCount();
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
+ }
+
+ public void forEach(Consumer<? super K> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = map.table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; )
+ action.accept(p.key);
+ }
+ }
+ }
+
+ /**
+ * A view of a ConcurrentHashMap as a {@link Collection} of
+ * values, in which additions are disabled. This class cannot be
+ * directly instantiated. See {@link #values()}.
+ */
+ static final class ValuesView<K,V> extends CollectionView<K,V,V>
+ implements Collection<V>, java.io.Serializable {
+ private static final long serialVersionUID = 2249069246763182397L;
+ ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
+ public final boolean contains(Object o) {
+ return map.containsValue(o);
+ }
+
+ public final boolean remove(Object o) {
+ if (o != null) {
+ for (Iterator<V> it = iterator(); it.hasNext();) {
+ if (o.equals(it.next())) {
+ it.remove();
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+ public final Iterator<V> iterator() {
+ ConcurrentHashMap<K,V> m = map;
+ Node<K,V>[] t;
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new ValueIterator<K,V>(t, f, 0, f, m);
+ }
+
+ public final boolean add(V e) {
+ throw new UnsupportedOperationException();
+ }
+ public final boolean addAll(Collection<? extends V> c) {
+ throw new UnsupportedOperationException();
+ }
+
+ @Override public boolean removeAll(Collection<?> c) {
+ if (c == null) throw new NullPointerException();
+ boolean modified = false;
+ for (Iterator<V> it = iterator(); it.hasNext();) {
+ if (c.contains(it.next())) {
+ it.remove();
+ modified = true;
+ }
+ }
+ return modified;
+ }
+
+ public boolean removeIf(Predicate<? super V> filter) {
+ return map.removeValueIf(filter);
+ }
+
+ public Spliterator<V> spliterator() {
+ Node<K,V>[] t;
+ ConcurrentHashMap<K,V> m = map;
+ long n = m.sumCount();
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
+ }
+
+ public void forEach(Consumer<? super V> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = map.table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; )
+ action.accept(p.val);
+ }
+ }
+ }
+
+ /**
+ * A view of a ConcurrentHashMap as a {@link Set} of (key, value)
+ * entries. This class cannot be directly instantiated. See
+ * {@link #entrySet()}.
+ */
+ static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
+ implements Set<Map.Entry<K,V>>, java.io.Serializable {
+ private static final long serialVersionUID = 2249069246763182397L;
+ EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
+
+ public boolean contains(Object o) {
+ Object k, v, r; Map.Entry<?,?> e;
+ return ((o instanceof Map.Entry) &&
+ (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
+ (r = map.get(k)) != null &&
+ (v = e.getValue()) != null &&
+ (v == r || v.equals(r)));
+ }
+
+ public boolean remove(Object o) {
+ Object k, v; Map.Entry<?,?> e;
+ return ((o instanceof Map.Entry) &&
+ (k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
+ (v = e.getValue()) != null &&
+ map.remove(k, v));
+ }
+
+ /**
+ * @return an iterator over the entries of the backing map
+ */
+ public Iterator<Map.Entry<K,V>> iterator() {
+ ConcurrentHashMap<K,V> m = map;
+ Node<K,V>[] t;
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new EntryIterator<K,V>(t, f, 0, f, m);
+ }
+
+ public boolean add(Entry<K,V> e) {
+ return map.putVal(e.getKey(), e.getValue(), false) == null;
+ }
+
+ public boolean addAll(Collection<? extends Entry<K,V>> c) {
+ boolean added = false;
+ for (Entry<K,V> e : c) {
+ if (add(e))
+ added = true;
+ }
+ return added;
+ }
+
+ public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
+ return map.removeEntryIf(filter);
+ }
+
+ public final int hashCode() {
+ int h = 0;
+ Node<K,V>[] t;
+ if ((t = map.table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; ) {
+ h += p.hashCode();
+ }
+ }
+ return h;
+ }
+
+ public final boolean equals(Object o) {
+ Set<?> c;
+ return ((o instanceof Set) &&
+ ((c = (Set<?>)o) == this ||
+ (containsAll(c) && c.containsAll(this))));
+ }
+
+ public Spliterator<Map.Entry<K,V>> spliterator() {
+ Node<K,V>[] t;
+ ConcurrentHashMap<K,V> m = map;
+ long n = m.sumCount();
+ int f = (t = m.table) == null ? 0 : t.length;
+ return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
+ }
+
+ public void forEach(Consumer<? super Map.Entry<K,V>> action) {
+ if (action == null) throw new NullPointerException();
+ Node<K,V>[] t;
+ if ((t = map.table) != null) {
+ Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
+ for (Node<K,V> p; (p = it.advance()) != null; )
+ action.accept(new MapEntry<K,V>(p.key, p.val, map));
+ }
+ }
+
+ }
+
+ // -------------------------------------------------------
+
+ /**
+ * Base class for bulk tasks. Repeats some fields and code from
+ * class Traverser, because we need to subclass CountedCompleter.
+ */
+ @SuppressWarnings("serial")
+ abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
+ Node<K,V>[] tab; // same as Traverser
+ Node<K,V> next;
+ TableStack<K,V> stack, spare;
+ int index;
+ int baseIndex;
+ int baseLimit;
+ final int baseSize;
+ int batch; // split control
+
+ BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
+ super(par);
+ this.batch = b;
+ this.index = this.baseIndex = i;
+ if ((this.tab = t) == null)
+ this.baseSize = this.baseLimit = 0;
+ else if (par == null)
+ this.baseSize = this.baseLimit = t.length;
+ else {
+ this.baseLimit = f;
+ this.baseSize = par.baseSize;
+ }
+ }
+
+ /**
+ * Same as Traverser version.
+ */
+ final Node<K,V> advance() {
+ Node<K,V> e;
+ if ((e = next) != null)
+ e = e.next;
+ for (;;) {
+ Node<K,V>[] t; int i, n;
+ if (e != null)
+ return next = e;
+ if (baseIndex >= baseLimit || (t = tab) == null ||
+ (n = t.length) <= (i = index) || i < 0)
+ return next = null;
+ if ((e = tabAt(t, i)) != null && e.hash < 0) {
+ if (e instanceof ForwardingNode) {
+ tab = ((ForwardingNode<K,V>)e).nextTable;
+ e = null;
+ pushState(t, i, n);
+ continue;
+ }
+ else if (e instanceof TreeBin)
+ e = ((TreeBin<K,V>)e).first;
+ else
+ e = null;
+ }
+ if (stack != null)
+ recoverState(n);
+ else if ((index = i + baseSize) >= n)
+ index = ++baseIndex;
+ }
+ }
+
+ private void pushState(Node<K,V>[] t, int i, int n) {
+ TableStack<K,V> s = spare;
+ if (s != null)
+ spare = s.next;
+ else
+ s = new TableStack<K,V>();
+ s.tab = t;
+ s.length = n;
+ s.index = i;
+ s.next = stack;
+ stack = s;
+ }
+
+ private void recoverState(int n) {
+ TableStack<K,V> s; int len;
+ while ((s = stack) != null && (index += (len = s.length)) >= n) {
+ n = len;
+ index = s.index;
+ tab = s.tab;
+ s.tab = null;
+ TableStack<K,V> next = s.next;
+ s.next = spare; // save for reuse
+ stack = next;
+ spare = s;
+ }
+ if (s == null && (index += baseSize) >= n)
+ index = ++baseIndex;
+ }
+ }
+
+ /*
+ * Task classes. Coded in a regular but ugly format/style to
+ * simplify checks that each variant differs in the right way from
+ * others. The null screenings exist because compilers cannot tell
+ * that we've already null-checked task arguments, so we force
+ * simplest hoisted bypass to help avoid convoluted traps.
+ */
+ @SuppressWarnings("serial")
+ static final class ForEachKeyTask<K,V>
+ extends BulkTask<K,V,Void> {
+ final Consumer<? super K> action;
+ ForEachKeyTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Consumer<? super K> action) {
+ super(p, b, i, f, t);
+ this.action = action;
+ }
+ public final void compute() {
+ final Consumer<? super K> action;
+ if ((action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachKeyTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null;)
+ action.accept(p.key);
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachValueTask<K,V>
+ extends BulkTask<K,V,Void> {
+ final Consumer<? super V> action;
+ ForEachValueTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Consumer<? super V> action) {
+ super(p, b, i, f, t);
+ this.action = action;
+ }
+ public final void compute() {
+ final Consumer<? super V> action;
+ if ((action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachValueTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null;)
+ action.accept(p.val);
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachEntryTask<K,V>
+ extends BulkTask<K,V,Void> {
+ final Consumer<? super Entry<K,V>> action;
+ ForEachEntryTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Consumer<? super Entry<K,V>> action) {
+ super(p, b, i, f, t);
+ this.action = action;
+ }
+ public final void compute() {
+ final Consumer<? super Entry<K,V>> action;
+ if ((action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachEntryTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ action.accept(p);
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachMappingTask<K,V>
+ extends BulkTask<K,V,Void> {
+ final BiConsumer<? super K, ? super V> action;
+ ForEachMappingTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ BiConsumer<? super K,? super V> action) {
+ super(p, b, i, f, t);
+ this.action = action;
+ }
+ public final void compute() {
+ final BiConsumer<? super K, ? super V> action;
+ if ((action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachMappingTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ action.accept(p.key, p.val);
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachTransformedKeyTask<K,V,U>
+ extends BulkTask<K,V,Void> {
+ final Function<? super K, ? extends U> transformer;
+ final Consumer<? super U> action;
+ ForEachTransformedKeyTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
+ super(p, b, i, f, t);
+ this.transformer = transformer; this.action = action;
+ }
+ public final void compute() {
+ final Function<? super K, ? extends U> transformer;
+ final Consumer<? super U> action;
+ if ((transformer = this.transformer) != null &&
+ (action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachTransformedKeyTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ transformer, action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.key)) != null)
+ action.accept(u);
+ }
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachTransformedValueTask<K,V,U>
+ extends BulkTask<K,V,Void> {
+ final Function<? super V, ? extends U> transformer;
+ final Consumer<? super U> action;
+ ForEachTransformedValueTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
+ super(p, b, i, f, t);
+ this.transformer = transformer; this.action = action;
+ }
+ public final void compute() {
+ final Function<? super V, ? extends U> transformer;
+ final Consumer<? super U> action;
+ if ((transformer = this.transformer) != null &&
+ (action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachTransformedValueTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ transformer, action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.val)) != null)
+ action.accept(u);
+ }
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachTransformedEntryTask<K,V,U>
+ extends BulkTask<K,V,Void> {
+ final Function<Map.Entry<K,V>, ? extends U> transformer;
+ final Consumer<? super U> action;
+ ForEachTransformedEntryTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
+ super(p, b, i, f, t);
+ this.transformer = transformer; this.action = action;
+ }
+ public final void compute() {
+ final Function<Map.Entry<K,V>, ? extends U> transformer;
+ final Consumer<? super U> action;
+ if ((transformer = this.transformer) != null &&
+ (action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachTransformedEntryTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ transformer, action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p)) != null)
+ action.accept(u);
+ }
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ForEachTransformedMappingTask<K,V,U>
+ extends BulkTask<K,V,Void> {
+ final BiFunction<? super K, ? super V, ? extends U> transformer;
+ final Consumer<? super U> action;
+ ForEachTransformedMappingTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ BiFunction<? super K, ? super V, ? extends U> transformer,
+ Consumer<? super U> action) {
+ super(p, b, i, f, t);
+ this.transformer = transformer; this.action = action;
+ }
+ public final void compute() {
+ final BiFunction<? super K, ? super V, ? extends U> transformer;
+ final Consumer<? super U> action;
+ if ((transformer = this.transformer) != null &&
+ (action = this.action) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ new ForEachTransformedMappingTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ transformer, action).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.key, p.val)) != null)
+ action.accept(u);
+ }
+ propagateCompletion();
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class SearchKeysTask<K,V,U>
+ extends BulkTask<K,V,U> {
+ final Function<? super K, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ SearchKeysTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<? super K, ? extends U> searchFunction,
+ AtomicReference<U> result) {
+ super(p, b, i, f, t);
+ this.searchFunction = searchFunction; this.result = result;
+ }
+ public final U getRawResult() { return result.get(); }
+ public final void compute() {
+ final Function<? super K, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ if ((searchFunction = this.searchFunction) != null &&
+ (result = this.result) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ if (result.get() != null)
+ return;
+ addToPendingCount(1);
+ new SearchKeysTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ searchFunction, result).fork();
+ }
+ while (result.get() == null) {
+ U u;
+ Node<K,V> p;
+ if ((p = advance()) == null) {
+ propagateCompletion();
+ break;
+ }
+ if ((u = searchFunction.apply(p.key)) != null) {
+ if (result.compareAndSet(null, u))
+ quietlyCompleteRoot();
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class SearchValuesTask<K,V,U>
+ extends BulkTask<K,V,U> {
+ final Function<? super V, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ SearchValuesTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<? super V, ? extends U> searchFunction,
+ AtomicReference<U> result) {
+ super(p, b, i, f, t);
+ this.searchFunction = searchFunction; this.result = result;
+ }
+ public final U getRawResult() { return result.get(); }
+ public final void compute() {
+ final Function<? super V, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ if ((searchFunction = this.searchFunction) != null &&
+ (result = this.result) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ if (result.get() != null)
+ return;
+ addToPendingCount(1);
+ new SearchValuesTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ searchFunction, result).fork();
+ }
+ while (result.get() == null) {
+ U u;
+ Node<K,V> p;
+ if ((p = advance()) == null) {
+ propagateCompletion();
+ break;
+ }
+ if ((u = searchFunction.apply(p.val)) != null) {
+ if (result.compareAndSet(null, u))
+ quietlyCompleteRoot();
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class SearchEntriesTask<K,V,U>
+ extends BulkTask<K,V,U> {
+ final Function<Entry<K,V>, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ SearchEntriesTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ Function<Entry<K,V>, ? extends U> searchFunction,
+ AtomicReference<U> result) {
+ super(p, b, i, f, t);
+ this.searchFunction = searchFunction; this.result = result;
+ }
+ public final U getRawResult() { return result.get(); }
+ public final void compute() {
+ final Function<Entry<K,V>, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ if ((searchFunction = this.searchFunction) != null &&
+ (result = this.result) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ if (result.get() != null)
+ return;
+ addToPendingCount(1);
+ new SearchEntriesTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ searchFunction, result).fork();
+ }
+ while (result.get() == null) {
+ U u;
+ Node<K,V> p;
+ if ((p = advance()) == null) {
+ propagateCompletion();
+ break;
+ }
+ if ((u = searchFunction.apply(p)) != null) {
+ if (result.compareAndSet(null, u))
+ quietlyCompleteRoot();
+ return;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class SearchMappingsTask<K,V,U>
+ extends BulkTask<K,V,U> {
+ final BiFunction<? super K, ? super V, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ SearchMappingsTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ BiFunction<? super K, ? super V, ? extends U> searchFunction,
+ AtomicReference<U> result) {
+ super(p, b, i, f, t);
+ this.searchFunction = searchFunction; this.result = result;
+ }
+ public final U getRawResult() { return result.get(); }
+ public final void compute() {
+ final BiFunction<? super K, ? super V, ? extends U> searchFunction;
+ final AtomicReference<U> result;
+ if ((searchFunction = this.searchFunction) != null &&
+ (result = this.result) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ if (result.get() != null)
+ return;
+ addToPendingCount(1);
+ new SearchMappingsTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ searchFunction, result).fork();
+ }
+ while (result.get() == null) {
+ U u;
+ Node<K,V> p;
+ if ((p = advance()) == null) {
+ propagateCompletion();
+ break;
+ }
+ if ((u = searchFunction.apply(p.key, p.val)) != null) {
+ if (result.compareAndSet(null, u))
+ quietlyCompleteRoot();
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ReduceKeysTask<K,V>
+ extends BulkTask<K,V,K> {
+ final BiFunction<? super K, ? super K, ? extends K> reducer;
+ K result;
+ ReduceKeysTask<K,V> rights, nextRight;
+ ReduceKeysTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ ReduceKeysTask<K,V> nextRight,
+ BiFunction<? super K, ? super K, ? extends K> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.reducer = reducer;
+ }
+ public final K getRawResult() { return result; }
+ public final void compute() {
+ final BiFunction<? super K, ? super K, ? extends K> reducer;
+ if ((reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new ReduceKeysTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, reducer)).fork();
+ }
+ K r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ K u = p.key;
+ r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ReduceValuesTask<K,V>
+ extends BulkTask<K,V,V> {
+ final BiFunction<? super V, ? super V, ? extends V> reducer;
+ V result;
+ ReduceValuesTask<K,V> rights, nextRight;
+ ReduceValuesTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ ReduceValuesTask<K,V> nextRight,
+ BiFunction<? super V, ? super V, ? extends V> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.reducer = reducer;
+ }
+ public final V getRawResult() { return result; }
+ public final void compute() {
+ final BiFunction<? super V, ? super V, ? extends V> reducer;
+ if ((reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new ReduceValuesTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, reducer)).fork();
+ }
+ V r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ V v = p.val;
+ r = (r == null) ? v : reducer.apply(r, v);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class ReduceEntriesTask<K,V>
+ extends BulkTask<K,V,Map.Entry<K,V>> {
+ final BiFunction<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
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ ReduceEntriesTask<K,V> nextRight,
+ BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.reducer = reducer;
+ }
+ public final Map.Entry<K,V> getRawResult() { return result; }
+ public final void compute() {
+ final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
+ if ((reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new ReduceEntriesTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, reducer)).fork();
+ }
+ Map.Entry<K,V> r = null;
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = (r == null) ? p : reducer.apply(r, p);
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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 BulkTask<K,V,U> {
+ final Function<? super K, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ U result;
+ MapReduceKeysTask<K,V,U> rights, nextRight;
+ MapReduceKeysTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceKeysTask<K,V,U> nextRight,
+ Function<? super K, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.reducer = reducer;
+ }
+ public final U getRawResult() { return result; }
+ public final void compute() {
+ final Function<? super K, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceKeysTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, reducer)).fork();
+ }
+ U r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.key)) != null)
+ r = (r == null) ? u : reducer.apply(r, u);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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 BulkTask<K,V,U> {
+ final Function<? super V, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ U result;
+ MapReduceValuesTask<K,V,U> rights, nextRight;
+ MapReduceValuesTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceValuesTask<K,V,U> nextRight,
+ Function<? super V, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.reducer = reducer;
+ }
+ public final U getRawResult() { return result; }
+ public final void compute() {
+ final Function<? super V, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceValuesTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, reducer)).fork();
+ }
+ U r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.val)) != null)
+ r = (r == null) ? u : reducer.apply(r, u);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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 BulkTask<K,V,U> {
+ final Function<Map.Entry<K,V>, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ U result;
+ MapReduceEntriesTask<K,V,U> rights, nextRight;
+ MapReduceEntriesTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceEntriesTask<K,V,U> nextRight,
+ Function<Map.Entry<K,V>, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.reducer = reducer;
+ }
+ public final U getRawResult() { return result; }
+ public final void compute() {
+ final Function<Map.Entry<K,V>, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceEntriesTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, reducer)).fork();
+ }
+ U r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p)) != null)
+ r = (r == null) ? u : reducer.apply(r, u);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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 BulkTask<K,V,U> {
+ final BiFunction<? super K, ? super V, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ U result;
+ MapReduceMappingsTask<K,V,U> rights, nextRight;
+ MapReduceMappingsTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceMappingsTask<K,V,U> nextRight,
+ BiFunction<? super K, ? super V, ? extends U> transformer,
+ BiFunction<? super U, ? super U, ? extends U> reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.reducer = reducer;
+ }
+ public final U getRawResult() { return result; }
+ public final void compute() {
+ final BiFunction<? super K, ? super V, ? extends U> transformer;
+ final BiFunction<? super U, ? super U, ? extends U> reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceMappingsTask<K,V,U>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, reducer)).fork();
+ }
+ U r = null;
+ for (Node<K,V> p; (p = advance()) != null; ) {
+ U u;
+ if ((u = transformer.apply(p.key, p.val)) != null)
+ r = (r == null) ? u : reducer.apply(r, u);
+ }
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ 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 BulkTask<K,V,Double> {
+ final ToDoubleFunction<? super K> transformer;
+ final DoubleBinaryOperator reducer;
+ final double basis;
+ double result;
+ MapReduceKeysToDoubleTask<K,V> rights, nextRight;
+ MapReduceKeysToDoubleTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceKeysToDoubleTask<K,V> nextRight,
+ ToDoubleFunction<? super K> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Double getRawResult() { return result; }
+ public final void compute() {
+ final ToDoubleFunction<? super K> transformer;
+ final DoubleBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ double r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceKeysToDoubleTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceKeysToDoubleTask<K,V>
+ t = (MapReduceKeysToDoubleTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsDouble(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceValuesToDoubleTask<K,V>
+ extends BulkTask<K,V,Double> {
+ final ToDoubleFunction<? super V> transformer;
+ final DoubleBinaryOperator reducer;
+ final double basis;
+ double result;
+ MapReduceValuesToDoubleTask<K,V> rights, nextRight;
+ MapReduceValuesToDoubleTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceValuesToDoubleTask<K,V> nextRight,
+ ToDoubleFunction<? super V> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Double getRawResult() { return result; }
+ public final void compute() {
+ final ToDoubleFunction<? super V> transformer;
+ final DoubleBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ double r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceValuesToDoubleTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceValuesToDoubleTask<K,V>
+ t = (MapReduceValuesToDoubleTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsDouble(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceEntriesToDoubleTask<K,V>
+ extends BulkTask<K,V,Double> {
+ final ToDoubleFunction<Map.Entry<K,V>> transformer;
+ final DoubleBinaryOperator reducer;
+ final double basis;
+ double result;
+ MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
+ MapReduceEntriesToDoubleTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceEntriesToDoubleTask<K,V> nextRight,
+ ToDoubleFunction<Map.Entry<K,V>> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Double getRawResult() { return result; }
+ public final void compute() {
+ final ToDoubleFunction<Map.Entry<K,V>> transformer;
+ final DoubleBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ double r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceEntriesToDoubleTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceEntriesToDoubleTask<K,V>
+ t = (MapReduceEntriesToDoubleTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsDouble(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceMappingsToDoubleTask<K,V>
+ extends BulkTask<K,V,Double> {
+ final ToDoubleBiFunction<? super K, ? super V> transformer;
+ final DoubleBinaryOperator reducer;
+ final double basis;
+ double result;
+ MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
+ MapReduceMappingsToDoubleTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceMappingsToDoubleTask<K,V> nextRight,
+ ToDoubleBiFunction<? super K, ? super V> transformer,
+ double basis,
+ DoubleBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Double getRawResult() { return result; }
+ public final void compute() {
+ final ToDoubleBiFunction<? super K, ? super V> transformer;
+ final DoubleBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ double r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceMappingsToDoubleTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceMappingsToDoubleTask<K,V>
+ t = (MapReduceMappingsToDoubleTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsDouble(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceKeysToLongTask<K,V>
+ extends BulkTask<K,V,Long> {
+ final ToLongFunction<? super K> transformer;
+ final LongBinaryOperator reducer;
+ final long basis;
+ long result;
+ MapReduceKeysToLongTask<K,V> rights, nextRight;
+ MapReduceKeysToLongTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceKeysToLongTask<K,V> nextRight,
+ ToLongFunction<? super K> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Long getRawResult() { return result; }
+ public final void compute() {
+ final ToLongFunction<? super K> transformer;
+ final LongBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ long r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceKeysToLongTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceKeysToLongTask<K,V>
+ t = (MapReduceKeysToLongTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsLong(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceValuesToLongTask<K,V>
+ extends BulkTask<K,V,Long> {
+ final ToLongFunction<? super V> transformer;
+ final LongBinaryOperator reducer;
+ final long basis;
+ long result;
+ MapReduceValuesToLongTask<K,V> rights, nextRight;
+ MapReduceValuesToLongTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceValuesToLongTask<K,V> nextRight,
+ ToLongFunction<? super V> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Long getRawResult() { return result; }
+ public final void compute() {
+ final ToLongFunction<? super V> transformer;
+ final LongBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ long r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceValuesToLongTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceValuesToLongTask<K,V>
+ t = (MapReduceValuesToLongTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsLong(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceEntriesToLongTask<K,V>
+ extends BulkTask<K,V,Long> {
+ final ToLongFunction<Map.Entry<K,V>> transformer;
+ final LongBinaryOperator reducer;
+ final long basis;
+ long result;
+ MapReduceEntriesToLongTask<K,V> rights, nextRight;
+ MapReduceEntriesToLongTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceEntriesToLongTask<K,V> nextRight,
+ ToLongFunction<Map.Entry<K,V>> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Long getRawResult() { return result; }
+ public final void compute() {
+ final ToLongFunction<Map.Entry<K,V>> transformer;
+ final LongBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ long r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceEntriesToLongTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsLong(r, transformer.applyAsLong(p));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceEntriesToLongTask<K,V>
+ t = (MapReduceEntriesToLongTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsLong(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceMappingsToLongTask<K,V>
+ extends BulkTask<K,V,Long> {
+ final ToLongBiFunction<? super K, ? super V> transformer;
+ final LongBinaryOperator reducer;
+ final long basis;
+ long result;
+ MapReduceMappingsToLongTask<K,V> rights, nextRight;
+ MapReduceMappingsToLongTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceMappingsToLongTask<K,V> nextRight,
+ ToLongBiFunction<? super K, ? super V> transformer,
+ long basis,
+ LongBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Long getRawResult() { return result; }
+ public final void compute() {
+ final ToLongBiFunction<? super K, ? super V> transformer;
+ final LongBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ long r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceMappingsToLongTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceMappingsToLongTask<K,V>
+ t = (MapReduceMappingsToLongTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsLong(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceKeysToIntTask<K,V>
+ extends BulkTask<K,V,Integer> {
+ final ToIntFunction<? super K> transformer;
+ final IntBinaryOperator reducer;
+ final int basis;
+ int result;
+ MapReduceKeysToIntTask<K,V> rights, nextRight;
+ MapReduceKeysToIntTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceKeysToIntTask<K,V> nextRight,
+ ToIntFunction<? super K> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Integer getRawResult() { return result; }
+ public final void compute() {
+ final ToIntFunction<? super K> transformer;
+ final IntBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ int r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceKeysToIntTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceKeysToIntTask<K,V>
+ t = (MapReduceKeysToIntTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsInt(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceValuesToIntTask<K,V>
+ extends BulkTask<K,V,Integer> {
+ final ToIntFunction<? super V> transformer;
+ final IntBinaryOperator reducer;
+ final int basis;
+ int result;
+ MapReduceValuesToIntTask<K,V> rights, nextRight;
+ MapReduceValuesToIntTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceValuesToIntTask<K,V> nextRight,
+ ToIntFunction<? super V> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Integer getRawResult() { return result; }
+ public final void compute() {
+ final ToIntFunction<? super V> transformer;
+ final IntBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ int r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceValuesToIntTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceValuesToIntTask<K,V>
+ t = (MapReduceValuesToIntTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsInt(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceEntriesToIntTask<K,V>
+ extends BulkTask<K,V,Integer> {
+ final ToIntFunction<Map.Entry<K,V>> transformer;
+ final IntBinaryOperator reducer;
+ final int basis;
+ int result;
+ MapReduceEntriesToIntTask<K,V> rights, nextRight;
+ MapReduceEntriesToIntTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceEntriesToIntTask<K,V> nextRight,
+ ToIntFunction<Map.Entry<K,V>> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Integer getRawResult() { return result; }
+ public final void compute() {
+ final ToIntFunction<Map.Entry<K,V>> transformer;
+ final IntBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ int r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceEntriesToIntTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsInt(r, transformer.applyAsInt(p));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceEntriesToIntTask<K,V>
+ t = (MapReduceEntriesToIntTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsInt(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ @SuppressWarnings("serial")
+ static final class MapReduceMappingsToIntTask<K,V>
+ extends BulkTask<K,V,Integer> {
+ final ToIntBiFunction<? super K, ? super V> transformer;
+ final IntBinaryOperator reducer;
+ final int basis;
+ int result;
+ MapReduceMappingsToIntTask<K,V> rights, nextRight;
+ MapReduceMappingsToIntTask
+ (BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
+ MapReduceMappingsToIntTask<K,V> nextRight,
+ ToIntBiFunction<? super K, ? super V> transformer,
+ int basis,
+ IntBinaryOperator reducer) {
+ super(p, b, i, f, t); this.nextRight = nextRight;
+ this.transformer = transformer;
+ this.basis = basis; this.reducer = reducer;
+ }
+ public final Integer getRawResult() { return result; }
+ public final void compute() {
+ final ToIntBiFunction<? super K, ? super V> transformer;
+ final IntBinaryOperator reducer;
+ if ((transformer = this.transformer) != null &&
+ (reducer = this.reducer) != null) {
+ int r = this.basis;
+ for (int i = baseIndex, f, h; batch > 0 &&
+ (h = ((f = baseLimit) + i) >>> 1) > i;) {
+ addToPendingCount(1);
+ (rights = new MapReduceMappingsToIntTask<K,V>
+ (this, batch >>>= 1, baseLimit = h, f, tab,
+ rights, transformer, r, reducer)).fork();
+ }
+ for (Node<K,V> p; (p = advance()) != null; )
+ r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
+ result = r;
+ CountedCompleter<?> c;
+ for (c = firstComplete(); c != null; c = c.nextComplete()) {
+ @SuppressWarnings("unchecked")
+ MapReduceMappingsToIntTask<K,V>
+ t = (MapReduceMappingsToIntTask<K,V>)c,
+ s = t.rights;
+ while (s != null) {
+ t.result = reducer.applyAsInt(t.result, s.result);
+ s = t.rights = s.nextRight;
+ }
+ }
+ }
+ }
+ }
+
+ // Unsafe mechanics
+ private static final Unsafe U = Unsafe.getUnsafe();
+ private static final long SIZECTL;
+ private static final long TRANSFERINDEX;
+ private static final long BASECOUNT;
+ private static final long CELLSBUSY;
+ private static final long CELLVALUE;
+ private static final int ABASE;
+ private static final int ASHIFT;
+
+ static {
+ SIZECTL = U.objectFieldOffset
+ (ConcurrentHashMap.class, "sizeCtl");
+ TRANSFERINDEX = U.objectFieldOffset
+ (ConcurrentHashMap.class, "transferIndex");
+ BASECOUNT = U.objectFieldOffset
+ (ConcurrentHashMap.class, "baseCount");
+ CELLSBUSY = U.objectFieldOffset
+ (ConcurrentHashMap.class, "cellsBusy");
+
+ CELLVALUE = U.objectFieldOffset
+ (CounterCell.class, "value");
+
+ ABASE = U.arrayBaseOffset(Node[].class);
+ int scale = U.arrayIndexScale(Node[].class);
+ if ((scale & (scale - 1)) != 0)
+ throw new Error("array index scale not a power of two");
+ ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
+
+ // Reduce the risk of rare disastrous classloading in first call to
+ // LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
+ Class<?> ensureLoaded = LockSupport.class;
+ }
+}