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/*
 * 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 jsr166e;

import java.util.Comparator;
import java.util.Arrays;
import java.util.Map;
import java.util.Set;
import java.util.Collection;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.AbstractCollection;
import java.util.Hashtable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.ConcurrentModificationException;
import java.util.NoSuchElementException;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import java.io.Serializable;

/**
 * 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 not entail locking,
 * and there is not 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.
 *
 * 

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 completed update operations holding upon their * onset. (More formally, an update operation for a given key bears a * happens-before relation with any (non-null) retrieval for * that key reporting the updated value.) For aggregate operations * such as {@code putAll} and {@code clear}, concurrent retrievals may * reflect insertion or removal of only some entries. Similarly, * Iterators and Enumerations return elements reflecting the state of * the hash table at some point at or since the creation of the * iterator/enumeration. They do not throw {@link * ConcurrentModificationException}. However, iterators are designed * to be used by only one thread at a time. Bear in mind that the * results of aggregate status methods including {@code size}, {@code * isEmpty}, and {@code containsValue} are typically useful only when * a map is not undergoing concurrent updates in other threads. * Otherwise the results of these methods reflect transient states * that may be adequate for monitoring or estimation purposes, but not * for program control. * *

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. * *

A {@link Set} projection of a ConcurrentHashMapV8 may be created * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed * (using {@link #keySet(Object)} when only keys are of interest, and the * mapped values are (perhaps transiently) not used or all take the * same mapping value. * *

A ConcurrentHashMapV8 can be used as scalable frequency map (a * form of histogram or multiset) by using {@link LongAdder} values * and initializing via {@link #computeIfAbsent}. For example, to add * a count to a {@code ConcurrentHashMapV8 freqs}, you * can use {@code freqs.computeIfAbsent(k -> new * LongAdder()).increment();} * *

This class and its views and iterators implement all of the * optional methods of the {@link Map} and {@link Iterator} * interfaces. * *

Like {@link Hashtable} but unlike {@link HashMap}, this class * does not allow {@code null} to be used as a key or value. * *

ConcurrentHashMapV8s support sequential and parallel operations * bulk operations. (Parallel forms use the {@link * ForkJoinPool#commonPool()}). Tasks that may be used in other * contexts are available in class {@link ForkJoinTasks}. These * operations are designed to be safely, and often sensibly, applied * even with maps that are being concurrently updated by other * threads; for example, when computing a snapshot summary of the * values in a shared registry. There are three kinds of operation, * each with four forms, accepting functions with Keys, Values, * Entries, and (Key, Value) arguments and/or return values. Because * the elements of a ConcurrentHashMapV8 are not ordered in any * particular way, and may be processed in different orders in * different parallel executions, the correctness of supplied * functions should not depend on any ordering, or on any other * objects or values that may transiently change while computation is * in progress; and except for forEach actions, should ideally be * side-effect-free. * *

    *
  • forEach: Perform a given action on each element. * A variant form applies a given transformation on each element * before performing the action.
  • * *
  • search: Return the first available non-null result of * applying a given function on each element; skipping further * search when a result is found.
  • * *
  • reduce: Accumulate each element. The supplied reduction * function cannot rely on ordering (more formally, it should be * both associative and commutative). There are five variants: * *
      * *
    • Plain reductions. (There is not a form of this method for * (key, value) function arguments since there is no corresponding * return type.)
    • * *
    • Mapped reductions that accumulate the results of a given * function applied to each element.
    • * *
    • Reductions to scalar doubles, longs, and ints, using a * given basis value.
    • * * *
    *
* *

The concurrency properties of bulk operations follow * from those of ConcurrentHashMapV8: Any non-null result returned * from {@code get(key)} and related access methods bears a * happens-before relation with the associated insertion or * update. The result of any bulk operation reflects the * composition of these per-element relations (but is not * necessarily atomic with respect to the map as a whole unless it * is somehow known to be quiescent). Conversely, because keys * and values in the map are never null, null serves as a reliable * atomic indicator of the current lack of any result. To * maintain this property, null serves as an implicit basis for * all non-scalar reduction operations. For the double, long, and * int versions, the basis should be one that, when combined with * any other value, returns that other value (more formally, it * should be the identity element for the reduction). Most common * reductions have these properties; for example, computing a sum * with basis 0 or a minimum with basis MAX_VALUE. * *

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. * *

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)}. * *

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. * *

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. * *

All arguments to all task methods must be non-null. * *

jsr166e note: During transition, this class * uses nested functional interfaces with different names but the * same forms as those expected for JDK8. * *

This class is a member of the * * Java Collections Framework. * * @since 1.5 * @author Doug Lea * @param the type of keys maintained by this map * @param the type of mapped values */ public class ConcurrentHashMapV8 implements ConcurrentMap, Serializable { private static final long serialVersionUID = 7249069246763182397L; /** * A partitionable iterator. A Spliterator can be traversed * directly, but can also be partitioned (before traversal) by * creating another Spliterator that covers a non-overlapping * portion of the elements, and so may be amenable to parallel * execution. * *

This interface exports a subset of expected JDK8 * functionality. * *

Sample usage: Here is one (of the several) ways to compute * the sum of the values held in a map using the ForkJoin * framework. As illustrated here, Spliterators are well suited to * designs in which a task repeatedly splits off half its work * into forked subtasks until small enough to process directly, * and then joins these subtasks. Variants of this style can also * be used in completion-based designs. * *

     * {@code ConcurrentHashMapV8 m = ...
     * // split as if have 8 * parallelism, for load balance
     * int n = m.size();
     * int p = aForkJoinPool.getParallelism() * 8;
     * int split = (n < p)? n : p;
     * long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
     * // ...
     * static class SumValues extends RecursiveTask {
     *   final Spliterator s;
     *   final int split;             // split while > 1
     *   final SumValues nextJoin;    // records forked subtasks to join
     *   SumValues(Spliterator s, int depth, SumValues nextJoin) {
     *     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
     *   }
     *   public Long compute() {
     *     long sum = 0;
     *     SumValues subtasks = null; // fork subtasks
     *     for (int s = split >>> 1; s > 0; s >>>= 1)
     *       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
     *     while (s.hasNext())        // directly process remaining elements
     *       sum += s.next();
     *     for (SumValues t = subtasks; t != null; t = t.nextJoin)
     *       sum += t.join();         // collect subtask results
     *     return sum;
     *   }
     * }
     * }
*/ public static interface Spliterator extends Iterator { /** * Returns a Spliterator covering approximately half of the * elements, guaranteed not to overlap with those subsequently * returned by this Spliterator. After invoking this method, * the current Spliterator will not produce any of * the elements of the returned Spliterator, but the two * Spliterators together will produce all of the elements that * would have been produced by this Spliterator had this * method not been called. The exact number of elements * produced by the returned Spliterator is not guaranteed, and * may be zero (i.e., with {@code hasNext()} reporting {@code * false}) if this Spliterator cannot be further split. * * @return a Spliterator covering approximately half of the * elements * @throws IllegalStateException if this Spliterator has * already commenced traversing elements */ Spliterator split(); } /* * 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. * * Each key-value mapping is held in a Node. Because Node key * fields can contain special values, they are defined using plain * Object types (not type "K"). This leads to a lot of explicit * casting (and many explicit warning suppressions to tell * compilers not to complain about it). It also allows some of the * public methods to be factored into a smaller number of internal * methods (although sadly not so for the five variants of * put-related operations). The validation-based approach * explained below leads to a lot of code sprawl because * retry-control precludes factoring into smaller methods. * * The table is lazily initialized to a power-of-two size upon the * first insertion. Each bin in the table normally contains a * list of Nodes (most often, the list has only zero or one Node). * Table accesses require volatile/atomic reads, writes, and * CASes. Because there is no other way to arrange this without * adding further indirections, we use intrinsics * (sun.misc.Unsafe) operations. The lists of nodes within bins * are always accurately traversable under volatile reads, so long * as lookups check hash code and non-nullness of value before * checking key equality. * * We use the top (sign) bit of Node hash fields for control * purposes -- it is available anyway because of addressing * constraints. Nodes with negative hash fields are forwarding * nodes to either TreeBins or resized tables. The lower 31 bits * of each normal Node's hash field contain a transformation of * the key's hash code. * * 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). However, * operations that only conditionally update may inspect nodes * until the point of update. This is a converse of sorts to the * lazy locking technique described by Herlihy & Shavit. * * 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. Also, although we guard * against the worst effects of this (see method spread), sets of * hashes may differ only in bits that do not impact their bin * index for a given power-of-two mask. So we use a secondary * strategy that applies when the number of nodes in a bin exceeds * a threshold, and at least one of the keys implements * Comparable. These TreeBins use a balanced tree to hold nodes * (a specialized form of red-black trees), bounding search time * to O(log N). Each search step in a TreeBin is around twice as * slow as in a regular list, but given that N cannot exceed * (1<<64) (before running out of addresses) this bounds search * steps, lock hold times, etc, to reasonable constants (roughly * 100 nodes inspected per operation worst case) so long as keys * are Comparable (which is very common -- String, Long, etc). * TreeBin nodes (TreeNodes) also maintain the same "next" * traversal pointers as regular nodes, so can be traversed in * iterators in the same way. * * The table is resized when occupancy exceeds 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. To enable concurrency, the * next table must be (incrementally) prefilled with place-holders * serving as reverse forwarders to the old table. 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 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. However, to * ensure that no intervening nodes are skipped, bin splitting can * only begin after the associated reverse-forwarders are in * place. * * 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). The bulk * putAll operation further reduces contention by only committing * count updates upon these size checks. * * Maintaining API and serialization compatibility with previous * versions of this class introduces several oddities. Mainly: We * leave untouched but unused constructor arguments refering 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. */ /* ---------------- 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. The value reflects the approximate break-even point for * using tree-based operations. */ private static final int TREE_THRESHOLD = 8; /** * 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; /* * Encodings for Node hash fields. See above for explanation. */ static final int MOVED = 0x80000000; // hash field for forwarding nodes 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(); /* ---------------- Counters -------------- */ // Adapted from LongAdder and Striped64. // See their internal docs for explanation. // A padded cell for distributing counts static final class CounterCell { volatile long p0, p1, p2, p3, p4, p5, p6; volatile long value; volatile long q0, q1, q2, q3, q4, q5, q6; CounterCell(long x) { value = x; } } /** * Holder for the thread-local hash code determining which * CounterCell to use. The code is initialized via the * counterHashCodeGenerator, but may be moved upon collisions. */ static final class CounterHashCode { int code; } /** * Generates initial value for per-thread CounterHashCodes */ static final AtomicInteger counterHashCodeGenerator = new AtomicInteger(); /** * Increment for counterHashCodeGenerator. See class ThreadLocal * for explanation. */ static final int SEED_INCREMENT = 0x61c88647; /** * Per-thread counter hash codes. Shared across all instances. */ static final ThreadLocal threadCounterHashCode = new ThreadLocal(); /* ---------------- Fields -------------- */ /** * The array of bins. Lazily initialized upon first insertion. * Size is always a power of two. Accessed directly by iterators. */ transient volatile Node[] table; /** * The next table to use; non-null only while resizing. */ private transient volatile Node[] 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; /** * The least available table index to split while resizing. */ private transient volatile int transferOrigin; /** * Spinlock (locked via CAS) used when resizing and/or creating Cells. */ private transient volatile int counterBusy; /** * Table of counter cells. When non-null, size is a power of 2. */ private transient volatile CounterCell[] counterCells; // views private transient KeySetView keySet; private transient ValuesView values; private transient EntrySetView entrySet; /** For serialization compatibility. Null unless serialized; see below */ private Segment[] segments; /* ---------------- Table element access -------------- */ /* * Volatile access methods are used for table elements as well as * elements of in-progress next table while resizing. Uses are * null checked by callers, and implicitly bounds-checked, relying * on the invariants that tab arrays have non-zero size, and all * indices are masked with (tab.length - 1) which is never * negative and always less than length. Note that, to be correct * wrt arbitrary concurrency errors by users, bounds checks must * operate on local variables, which accounts for some odd-looking * inline assignments below. */ @SuppressWarnings("unchecked") static final Node tabAt (Node[] tab, int i) { // used by Traverser return (Node)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE); } private static final boolean casTabAt (Node[] tab, int i, Node c, Node v) { return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v); } private static final void setTabAt (Node[] tab, int i, Node v) { U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v); } /* ---------------- Nodes -------------- */ /** * Key-value entry. Note that this is never exported out as a * user-visible Map.Entry (see MapEntry below). Nodes with a hash * field of MOVED are special, and do not contain user keys or * values. Otherwise, keys are never null, and null val fields * indicate that a node is in the process of being deleted or * created. For purposes of read-only access, a key may be read * before a val, but can only be used after checking val to be * non-null. */ static class Node { final int hash; final Object key; volatile V val; volatile Node next; Node(int hash, Object key, V val, Node next) { this.hash = hash; this.key = key; this.val = val; this.next = next; } } /* ---------------- TreeBins -------------- */ /** * Nodes for use in TreeBins */ static final class TreeNode extends Node { TreeNode parent; // red-black tree links TreeNode left; TreeNode right; TreeNode prev; // needed to unlink next upon deletion boolean red; TreeNode(int hash, Object key, V val, Node next, TreeNode parent) { super(hash, key, val, next); this.parent = parent; } } /** * A specialized form of red-black tree for use in bins * whose size exceeds a threshold. * * TreeBins use a special form of comparison for search and * related operations (which is the main reason we cannot use * existing collections such as TreeMaps). TreeBins contain * Comparable elements, but may contain others, as well as * elements that are Comparable but not necessarily Comparable * for the same T, so we cannot invoke compareTo among them. To * handle this, the tree is ordered primarily by hash value, then * by getClass().getName() order, and then by Comparator order * among elements of the same class. On lookup at a node, if * elements are not comparable or compare as 0, both left and * right children may need to be searched in the case of tied hash * values. (This corresponds to the full list search that would be * necessary if all elements were non-Comparable and had tied * hashes.) The red-black balancing code is updated from * pre-jdk-collections * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) * based in turn on Cormen, Leiserson, and Rivest "Introduction to * Algorithms" (CLR). * * TreeBins also maintain a separate locking discipline than * regular bins. Because they are forwarded via special MOVED * nodes at bin heads (which can never change once established), * we cannot use those nodes as locks. Instead, TreeBin * extends AbstractQueuedSynchronizer to support a simple form of * read-write lock. For update operations and table validation, * the exclusive form of lock behaves in the same way as bin-head * locks. However, lookups use shared read-lock mechanics to allow * multiple readers in the absence of writers. Additionally, * these lookups do not ever block: While the lock is not * available, they proceed along the slow traversal path (via * next-pointers) until the lock becomes available or the list is * exhausted, whichever comes first. (These cases are not fast, * but maximize aggregate expected throughput.) The AQS mechanics * for doing this are straightforward. The lock state is held as * AQS getState(). Read counts are negative; the write count (1) * is positive. There are no signalling preferences among readers * and writers. Since we don't need to export full Lock API, we * just override the minimal AQS methods and use them directly. */ static final class TreeBin extends AbstractQueuedSynchronizer { private static final long serialVersionUID = 2249069246763182397L; transient TreeNode root; // root of tree transient TreeNode first; // head of next-pointer list /* AQS overrides */ public final boolean isHeldExclusively() { return getState() > 0; } public final boolean tryAcquire(int ignore) { if (compareAndSetState(0, 1)) { setExclusiveOwnerThread(Thread.currentThread()); return true; } return false; } public final boolean tryRelease(int ignore) { setExclusiveOwnerThread(null); setState(0); return true; } public final int tryAcquireShared(int ignore) { for (int c;;) { if ((c = getState()) > 0) return -1; if (compareAndSetState(c, c -1)) return 1; } } public final boolean tryReleaseShared(int ignore) { int c; do {} while (!compareAndSetState(c = getState(), c + 1)); return c == -1; } /** From CLR */ private void rotateLeft(TreeNode p) { if (p != null) { TreeNode r = p.right, pp, rl; if ((rl = p.right = r.left) != null) rl.parent = p; if ((pp = r.parent = p.parent) == null) root = r; else if (pp.left == p) pp.left = r; else pp.right = r; r.left = p; p.parent = r; } } /** From CLR */ private void rotateRight(TreeNode p) { if (p != null) { TreeNode l = p.left, pp, lr; if ((lr = p.left = l.right) != null) lr.parent = p; if ((pp = l.parent = p.parent) == null) root = l; else if (pp.right == p) pp.right = l; else pp.left = l; l.right = p; p.parent = l; } } /** * Returns the TreeNode (or null if not found) for the given key * starting at given root. */ @SuppressWarnings("unchecked") final TreeNode getTreeNode (int h, Object k, TreeNode p) { Class c = k.getClass(); while (p != null) { int dir, ph; Object pk; Class pc; if ((ph = p.hash) == h) { if ((pk = p.key) == k || k.equals(pk)) return p; if (c != (pc = pk.getClass()) || !(k instanceof Comparable) || (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) { if ((dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName())) == 0) { TreeNode r = null, pl, pr; // check both sides if ((pr = p.right) != null && h >= pr.hash && (r = getTreeNode(h, k, pr)) != null) return r; else if ((pl = p.left) != null && h <= pl.hash) dir = -1; else // nothing there return null; } } } else dir = (h < ph) ? -1 : 1; p = (dir > 0) ? p.right : p.left; } return null; } /** * Wrapper for getTreeNode used by CHM.get. Tries to obtain * read-lock to call getTreeNode, but during failure to get * lock, searches along next links. */ final V getValue(int h, Object k) { Node r = null; int c = getState(); // Must read lock state first for (Node e = first; e != null; e = e.next) { if (c <= 0 && compareAndSetState(c, c - 1)) { try { r = getTreeNode(h, k, root); } finally { releaseShared(0); } break; } else if (e.hash == h && k.equals(e.key)) { r = e; break; } else c = getState(); } return r == null ? null : r.val; } /** * Finds or adds a node. * @return null if added */ @SuppressWarnings("unchecked") final TreeNode putTreeNode (int h, Object k, V v) { Class c = k.getClass(); TreeNode pp = root, p = null; int dir = 0; while (pp != null) { // find existing node or leaf to insert at int ph; Object pk; Class pc; p = pp; if ((ph = p.hash) == h) { if ((pk = p.key) == k || k.equals(pk)) return p; if (c != (pc = pk.getClass()) || !(k instanceof Comparable) || (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) { TreeNode s = null, r = null, pr; if ((dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName())) == 0) { if ((pr = p.right) != null && h >= pr.hash && (r = getTreeNode(h, k, pr)) != null) return r; else // continue left dir = -1; } else if ((pr = p.right) != null && h >= pr.hash) s = pr; if (s != null && (r = getTreeNode(h, k, s)) != null) return r; } } else dir = (h < ph) ? -1 : 1; pp = (dir > 0) ? p.right : p.left; } TreeNode f = first; TreeNode x = first = new TreeNode(h, k, v, f, p); if (p == null) root = x; else { // attach and rebalance; adapted from CLR TreeNode xp, xpp; if (f != null) f.prev = x; if (dir <= 0) p.left = x; else p.right = x; x.red = true; while (x != null && (xp = x.parent) != null && xp.red && (xpp = xp.parent) != null) { TreeNode xppl = xpp.left; if (xp == xppl) { TreeNode y = xpp.right; if (y != null && y.red) { y.red = false; xp.red = false; xpp.red = true; x = xpp; } else { if (x == xp.right) { rotateLeft(x = xp); xpp = (xp = x.parent) == null ? null : xp.parent; } if (xp != null) { xp.red = false; if (xpp != null) { xpp.red = true; rotateRight(xpp); } } } } else { TreeNode y = xppl; if (y != null && y.red) { y.red = false; xp.red = false; xpp.red = true; x = xpp; } else { if (x == xp.left) { rotateRight(x = xp); xpp = (xp = x.parent) == null ? null : xp.parent; } if (xp != null) { xp.red = false; if (xpp != null) { xpp.red = true; rotateLeft(xpp); } } } } } TreeNode r = root; if (r != null && r.red) r.red = false; } return null; } /** * Removes the given node, that must be present before this * call. This is messier than typical red-black deletion code * because we cannot swap the contents of an interior node * with a leaf successor that is pinned by "next" pointers * that are accessible independently of lock. So instead we * swap the tree linkages. */ final void deleteTreeNode(TreeNode p) { TreeNode next = (TreeNode)p.next; // unlink traversal pointers TreeNode pred = p.prev; if (pred == null) first = next; else pred.next = next; if (next != null) next.prev = pred; TreeNode replacement; TreeNode pl = p.left; TreeNode pr = p.right; if (pl != null && pr != null) { TreeNode s = pr, sl; while ((sl = s.left) != null) // find successor s = sl; boolean c = s.red; s.red = p.red; p.red = c; // swap colors TreeNode sr = s.right; TreeNode pp = p.parent; if (s == pr) { // p was s's direct parent p.parent = s; s.right = p; } else { TreeNode sp = s.parent; if ((p.parent = sp) != null) { if (s == sp.left) sp.left = p; else sp.right = p; } if ((s.right = pr) != null) pr.parent = s; } p.left = null; if ((p.right = sr) != null) sr.parent = p; if ((s.left = pl) != null) pl.parent = s; if ((s.parent = pp) == null) root = s; else if (p == pp.left) pp.left = s; else pp.right = s; replacement = sr; } else replacement = (pl != null) ? pl : pr; TreeNode pp = p.parent; if (replacement == null) { if (pp == null) { root = null; return; } replacement = p; } else { replacement.parent = pp; if (pp == null) root = replacement; else if (p == pp.left) pp.left = replacement; else pp.right = replacement; p.left = p.right = p.parent = null; } if (!p.red) { // rebalance, from CLR TreeNode x = replacement; while (x != null) { TreeNode xp, xpl; if (x.red || (xp = x.parent) == null) { x.red = false; break; } if (x == (xpl = xp.left)) { TreeNode sib = xp.right; if (sib != null && sib.red) { sib.red = false; xp.red = true; rotateLeft(xp); sib = (xp = x.parent) == null ? null : xp.right; } if (sib == null) x = xp; else { TreeNode sl = sib.left, sr = sib.right; if ((sr == null || !sr.red) && (sl == null || !sl.red)) { sib.red = true; x = xp; } else { if (sr == null || !sr.red) { if (sl != null) sl.red = false; sib.red = true; rotateRight(sib); sib = (xp = x.parent) == null ? null : xp.right; } if (sib != null) { sib.red = (xp == null) ? false : xp.red; if ((sr = sib.right) != null) sr.red = false; } if (xp != null) { xp.red = false; rotateLeft(xp); } x = root; } } } else { // symmetric TreeNode sib = xpl; if (sib != null && sib.red) { sib.red = false; xp.red = true; rotateRight(xp); sib = (xp = x.parent) == null ? null : xp.left; } if (sib == null) x = xp; else { TreeNode sl = sib.left, sr = sib.right; if ((sl == null || !sl.red) && (sr == null || !sr.red)) { sib.red = true; x = xp; } else { if (sl == null || !sl.red) { if (sr != null) sr.red = false; sib.red = true; rotateLeft(sib); sib = (xp = x.parent) == null ? null : xp.left; } if (sib != null) { sib.red = (xp == null) ? false : xp.red; if ((sl = sib.left) != null) sl.red = false; } if (xp != null) { xp.red = false; rotateRight(xp); } x = root; } } } } } if (p == replacement && (pp = p.parent) != null) { if (p == pp.left) // detach pointers pp.left = null; else if (p == pp.right) pp.right = null; p.parent = null; } } } /* ---------------- Collision reduction methods -------------- */ /** * Spreads higher bits to lower, and also forces top 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.) To counter this, * we apply a transform that spreads the impact of higher bits * downward. There is a tradeoff between speed, utility, and * quality of bit-spreading. Because many common sets of hashes * are already reasonably distributed across bits (so don't benefit * from spreading), and because we use trees to handle large sets * of collisions in bins, we don't need excessively high quality. */ private static final int spread(int h) { h ^= (h >>> 18) ^ (h >>> 12); return (h ^ (h >>> 10)) & HASH_BITS; } /** * Replaces a list bin with a tree bin if key is comparable. Call * only when locked. */ private final void replaceWithTreeBin(Node[] tab, int index, Object key) { if (key instanceof Comparable) { TreeBin t = new TreeBin(); for (Node e = tabAt(tab, index); e != null; e = e.next) t.putTreeNode(e.hash, e.key, e.val); setTabAt(tab, index, new Node(MOVED, t, null, null)); } } /* ---------------- Internal access and update methods -------------- */ /** Implementation for get and containsKey */ @SuppressWarnings("unchecked") private final V internalGet(Object k) { int h = spread(k.hashCode()); retry: for (Node[] tab = table; tab != null;) { Node e; Object ek; V ev; int eh; // locals to read fields once for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) { if ((eh = e.hash) < 0) { if ((ek = e.key) instanceof TreeBin) // search TreeBin return ((TreeBin)ek).getValue(h, k); else { // restart with new table tab = (Node[])ek; continue retry; } } else if (eh == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) return ev; } break; } return 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. */ @SuppressWarnings("unchecked") private final V internalReplace (Object k, V v, Object cv) { int h = spread(k.hashCode()); V oldVal = null; for (Node[] tab = table;;) { Node f; int i, fh; Object fk; if (tab == null || (f = tabAt(tab, i = (tab.length - 1) & h)) == null) break; else if ((fh = f.hash) < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; boolean validated = false; boolean deleted = false; t.acquire(0); try { if (tabAt(tab, i) == f) { validated = true; TreeNode p = t.getTreeNode(h, k, t.root); if (p != null) { V pv = p.val; if (cv == null || cv == pv || cv.equals(pv)) { oldVal = pv; if ((p.val = v) == null) { deleted = true; t.deleteTreeNode(p); } } } } } finally { t.release(0); } if (validated) { if (deleted) addCount(-1L, -1); break; } } else tab = (Node[])fk; } else if (fh != h && f.next == null) // precheck break; // rules out possible existence else { boolean validated = false; boolean deleted = false; synchronized (f) { if (tabAt(tab, i) == f) { validated = true; for (Node e = f, pred = null;;) { Object ek; V ev; if (e.hash == h && ((ev = e.val) != null) && ((ek = e.key) == k || k.equals(ek))) { if (cv == null || cv == ev || cv.equals(ev)) { oldVal = ev; if ((e.val = v) == null) { deleted = true; Node en = e.next; if (pred != null) pred.next = en; else setTabAt(tab, i, en); } } break; } pred = e; if ((e = e.next) == null) break; } } } if (validated) { if (deleted) addCount(-1L, -1); break; } } } return oldVal; } /* * Internal versions of insertion methods * All have the same basic structure as the first (internalPut): * 1. If table uninitialized, create * 2. If bin empty, try to CAS new node * 3. If bin stale, use new table * 4. if bin converted to TreeBin, validate and relay to TreeBin methods * 5. Lock and validate; if valid, scan and add or update * * The putAll method differs mainly in attempting to pre-allocate * enough table space, and also more lazily performs count updates * and checks. * * Most of the function-accepting methods can't be factored nicely * because they require different functional forms, so instead * sprawl out similar mechanics. */ /** Implementation for put and putIfAbsent */ @SuppressWarnings("unchecked") private final V internalPut (K k, V v, boolean onlyIfAbsent) { if (k == null || v == null) throw new NullPointerException(); int h = spread(k.hashCode()); int len = 0; for (Node[] tab = table;;) { int i, fh; Node f; Object fk; V fv; if (tab == null) tab = initTable(); else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { if (casTabAt(tab, i, null, new Node(h, k, v, null))) break; // no lock when adding to empty bin } else if ((fh = f.hash) < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; V oldVal = null; t.acquire(0); try { if (tabAt(tab, i) == f) { len = 2; TreeNode p = t.putTreeNode(h, k, v); if (p != null) { oldVal = p.val; if (!onlyIfAbsent) p.val = v; } } } finally { t.release(0); } if (len != 0) { if (oldVal != null) return oldVal; break; } } else tab = (Node[])fk; } else if (onlyIfAbsent && fh == h && (fv = f.val) != null && ((fk = f.key) == k || k.equals(fk))) // peek while nearby return fv; else { V oldVal = null; synchronized (f) { if (tabAt(tab, i) == f) { len = 1; for (Node e = f;; ++len) { Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) { oldVal = ev; if (!onlyIfAbsent) e.val = v; break; } Node last = e; if ((e = e.next) == null) { last.next = new Node(h, k, v, null); if (len >= TREE_THRESHOLD) replaceWithTreeBin(tab, i, k); break; } } } } if (len != 0) { if (oldVal != null) return oldVal; break; } } } addCount(1L, len); return null; } /** Implementation for computeIfAbsent */ @SuppressWarnings("unchecked") private final V internalComputeIfAbsent (K k, Fun mf) { if (k == null || mf == null) throw new NullPointerException(); int h = spread(k.hashCode()); V val = null; int len = 0; for (Node[] tab = table;;) { Node f; int i; Object fk; if (tab == null) tab = initTable(); else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { Node node = new Node(h, k, null, null); synchronized (node) { if (casTabAt(tab, i, null, node)) { len = 1; try { if ((val = mf.apply(k)) != null) node.val = val; } finally { if (val == null) setTabAt(tab, i, null); } } } if (len != 0) break; } else if (f.hash < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; boolean added = false; t.acquire(0); try { if (tabAt(tab, i) == f) { len = 1; TreeNode p = t.getTreeNode(h, k, t.root); if (p != null) val = p.val; else if ((val = mf.apply(k)) != null) { added = true; len = 2; t.putTreeNode(h, k, val); } } } finally { t.release(0); } if (len != 0) { if (!added) return val; break; } } else tab = (Node[])fk; } else { for (Node e = f; e != null; e = e.next) { // prescan Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) return ev; } boolean added = false; synchronized (f) { if (tabAt(tab, i) == f) { len = 1; for (Node e = f;; ++len) { Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) { val = ev; break; } Node last = e; if ((e = e.next) == null) { if ((val = mf.apply(k)) != null) { added = true; last.next = new Node(h, k, val, null); if (len >= TREE_THRESHOLD) replaceWithTreeBin(tab, i, k); } break; } } } } if (len != 0) { if (!added) return val; break; } } } if (val != null) addCount(1L, len); return val; } /** Implementation for compute */ @SuppressWarnings("unchecked") private final V internalCompute (K k, boolean onlyIfPresent, BiFun mf) { if (k == null || mf == null) throw new NullPointerException(); int h = spread(k.hashCode()); V val = null; int delta = 0; int len = 0; for (Node[] tab = table;;) { Node f; int i, fh; Object fk; if (tab == null) tab = initTable(); else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { if (onlyIfPresent) break; Node node = new Node(h, k, null, null); synchronized (node) { if (casTabAt(tab, i, null, node)) { try { len = 1; if ((val = mf.apply(k, null)) != null) { node.val = val; delta = 1; } } finally { if (delta == 0) setTabAt(tab, i, null); } } } if (len != 0) break; } else if ((fh = f.hash) < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; t.acquire(0); try { if (tabAt(tab, i) == f) { len = 1; TreeNode p = t.getTreeNode(h, k, t.root); if (p == null && onlyIfPresent) break; V pv = (p == null) ? null : p.val; if ((val = mf.apply(k, pv)) != null) { if (p != null) p.val = val; else { len = 2; delta = 1; t.putTreeNode(h, k, val); } } else if (p != null) { delta = -1; t.deleteTreeNode(p); } } } finally { t.release(0); } if (len != 0) break; } else tab = (Node[])fk; } else { synchronized (f) { if (tabAt(tab, i) == f) { len = 1; for (Node e = f, pred = null;; ++len) { Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) { val = mf.apply(k, ev); if (val != null) e.val = val; else { delta = -1; Node en = e.next; if (pred != null) pred.next = en; else setTabAt(tab, i, en); } break; } pred = e; if ((e = e.next) == null) { if (!onlyIfPresent && (val = mf.apply(k, null)) != null) { pred.next = new Node(h, k, val, null); delta = 1; if (len >= TREE_THRESHOLD) replaceWithTreeBin(tab, i, k); } break; } } } } if (len != 0) break; } } if (delta != 0) addCount((long)delta, len); return val; } /** Implementation for merge */ @SuppressWarnings("unchecked") private final V internalMerge (K k, V v, BiFun mf) { if (k == null || v == null || mf == null) throw new NullPointerException(); int h = spread(k.hashCode()); V val = null; int delta = 0; int len = 0; for (Node[] tab = table;;) { int i; Node f; Object fk; V fv; if (tab == null) tab = initTable(); else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { if (casTabAt(tab, i, null, new Node(h, k, v, null))) { delta = 1; val = v; break; } } else if (f.hash < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; t.acquire(0); try { if (tabAt(tab, i) == f) { len = 1; TreeNode p = t.getTreeNode(h, k, t.root); val = (p == null) ? v : mf.apply(p.val, v); if (val != null) { if (p != null) p.val = val; else { len = 2; delta = 1; t.putTreeNode(h, k, val); } } else if (p != null) { delta = -1; t.deleteTreeNode(p); } } } finally { t.release(0); } if (len != 0) break; } else tab = (Node[])fk; } else { synchronized (f) { if (tabAt(tab, i) == f) { len = 1; for (Node e = f, pred = null;; ++len) { Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) { val = mf.apply(ev, v); if (val != null) e.val = val; else { delta = -1; Node en = e.next; if (pred != null) pred.next = en; else setTabAt(tab, i, en); } break; } pred = e; if ((e = e.next) == null) { val = v; pred.next = new Node(h, k, val, null); delta = 1; if (len >= TREE_THRESHOLD) replaceWithTreeBin(tab, i, k); break; } } } } if (len != 0) break; } } if (delta != 0) addCount((long)delta, len); return val; } /** Implementation for putAll */ @SuppressWarnings("unchecked") private final void internalPutAll (Map m) { tryPresize(m.size()); long delta = 0L; // number of uncommitted additions boolean npe = false; // to throw exception on exit for nulls try { // to clean up counts on other exceptions for (Map.Entry entry : m.entrySet()) { Object k; V v; if (entry == null || (k = entry.getKey()) == null || (v = entry.getValue()) == null) { npe = true; break; } int h = spread(k.hashCode()); for (Node[] tab = table;;) { int i; Node f; int fh; Object fk; if (tab == null) tab = initTable(); else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){ if (casTabAt(tab, i, null, new Node(h, k, v, null))) { ++delta; break; } } else if ((fh = f.hash) < 0) { if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; boolean validated = false; t.acquire(0); try { if (tabAt(tab, i) == f) { validated = true; TreeNode p = t.getTreeNode(h, k, t.root); if (p != null) p.val = v; else { t.putTreeNode(h, k, v); ++delta; } } } finally { t.release(0); } if (validated) break; } else tab = (Node[])fk; } else { int len = 0; synchronized (f) { if (tabAt(tab, i) == f) { len = 1; for (Node e = f;; ++len) { Object ek; V ev; if (e.hash == h && (ev = e.val) != null && ((ek = e.key) == k || k.equals(ek))) { e.val = v; break; } Node last = e; if ((e = e.next) == null) { ++delta; last.next = new Node(h, k, v, null); if (len >= TREE_THRESHOLD) replaceWithTreeBin(tab, i, k); break; } } } } if (len != 0) { if (len > 1) { addCount(delta, len); delta = 0L; } break; } } } } } finally { if (delta != 0L) addCount(delta, 2); } if (npe) throw new NullPointerException(); } /** * Implementation for clear. Steps through each bin, removing all * nodes. */ @SuppressWarnings("unchecked") private final void internalClear() { long delta = 0L; // negative number of deletions int i = 0; Node[] tab = table; while (tab != null && i < tab.length) { Node f = tabAt(tab, i); if (f == null) ++i; else if (f.hash < 0) { Object fk; if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; t.acquire(0); try { if (tabAt(tab, i) == f) { for (Node p = t.first; p != null; p = p.next) { if (p.val != null) { // (currently always true) p.val = null; --delta; } } t.first = null; t.root = null; ++i; } } finally { t.release(0); } } else tab = (Node[])fk; } else { synchronized (f) { if (tabAt(tab, i) == f) { for (Node e = f; e != null; e = e.next) { if (e.val != null) { // (currently always true) e.val = null; --delta; } } setTabAt(tab, i, null); ++i; } } } } if (delta != 0L) addCount(delta, -1); } /* ---------------- Table Initialization and Resizing -------------- */ /** * 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; } /** * Initializes table, using the size recorded in sizeCtl. */ @SuppressWarnings("unchecked") private final Node[] initTable() { Node[] tab; int sc; while ((tab = table) == null) { if ((sc = sizeCtl) < 0) Thread.yield(); // lost initialization race; just spin else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { try { if ((tab = table) == null) { int n = (sc > 0) ? sc : DEFAULT_CAPACITY; @SuppressWarnings("rawtypes") Node[] tb = new Node[n]; table = tab = (Node[])tb; 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.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) { CounterHashCode hc; CounterCell a; long v; int m; boolean uncontended = true; if ((hc = threadCounterHashCode.get()) == null || as == null || (m = as.length - 1) < 0 || (a = as[m & hc.code]) == null || !(uncontended = U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) { fullAddCount(x, hc, uncontended); return; } if (check <= 1) return; s = sumCount(); } if (check >= 0) { Node[] tab, nt; int sc; while (s >= (long)(sc = sizeCtl) && (tab = table) != null && tab.length < MAXIMUM_CAPACITY) { if (sc < 0) { if (sc == -1 || transferIndex <= transferOrigin || (nt = nextTable) == null) break; if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) transfer(tab, nt); } else if (U.compareAndSwapInt(this, SIZECTL, sc, -2)) transfer(tab, null); s = sumCount(); } } } /** * Tries to presize table to accommodate the given number of elements. * * @param size number of elements (doesn't need to be perfectly accurate) */ @SuppressWarnings("unchecked") 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[] tab = table; int n; if (tab == null || (n = tab.length) == 0) { n = (sc > c) ? sc : c; if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { try { if (table == tab) { @SuppressWarnings("rawtypes") Node[] tb = new Node[n]; table = (Node[])tb; sc = n - (n >>> 2); } } finally { sizeCtl = sc; } } } else if (c <= sc || n >= MAXIMUM_CAPACITY) break; else if (tab == table && U.compareAndSwapInt(this, SIZECTL, sc, -2)) transfer(tab, null); } } /** * Moves and/or copies the nodes in each bin to new table. See * above for explanation. */ @SuppressWarnings("unchecked") private final void transfer (Node[] tab, Node[] 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("rawtypes") Node[] tb = new Node[n << 1]; nextTab = (Node[])tb; } catch (Throwable ex) { // try to cope with OOME sizeCtl = Integer.MAX_VALUE; return; } nextTable = nextTab; transferOrigin = n; transferIndex = n; Node rev = new Node(MOVED, tab, null, null); for (int k = n; k > 0;) { // progressively reveal ready slots int nextk = (k > stride) ? k - stride : 0; for (int m = nextk; m < k; ++m) nextTab[m] = rev; for (int m = n + nextk; m < n + k; ++m) nextTab[m] = rev; U.putOrderedInt(this, TRANSFERORIGIN, k = nextk); } } int nextn = nextTab.length; Node fwd = new Node(MOVED, nextTab, null, null); boolean advance = true; for (int i = 0, bound = 0;;) { int nextIndex, nextBound; Node f; Object fk; while (advance) { if (--i >= bound) advance = false; else if ((nextIndex = transferIndex) <= transferOrigin) { i = -1; advance = false; } else if (U.compareAndSwapInt (this, TRANSFERINDEX, nextIndex, nextBound = (nextIndex > stride ? nextIndex - stride : 0))) { bound = nextBound; i = nextIndex - 1; advance = false; } } if (i < 0 || i >= n || i + n >= nextn) { for (int sc;;) { if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) { if (sc == -1) { nextTable = null; table = nextTab; sizeCtl = (n << 1) - (n >>> 1); } return; } } } else if ((f = tabAt(tab, i)) == null) { if (casTabAt(tab, i, null, fwd)) { setTabAt(nextTab, i, null); setTabAt(nextTab, i + n, null); advance = true; } } else if (f.hash >= 0) { synchronized (f) { if (tabAt(tab, i) == f) { int runBit = f.hash & n; Node lastRun = f, lo = null, hi = null; for (Node p = f.next; p != null; p = p.next) { int b = p.hash & n; if (b != runBit) { runBit = b; lastRun = p; } } if (runBit == 0) lo = lastRun; else hi = lastRun; for (Node p = f; p != lastRun; p = p.next) { int ph = p.hash; Object pk = p.key; V pv = p.val; if ((ph & n) == 0) lo = new Node(ph, pk, pv, lo); else hi = new Node(ph, pk, pv, hi); } setTabAt(nextTab, i, lo); setTabAt(nextTab, i + n, hi); setTabAt(tab, i, fwd); advance = true; } } } else if ((fk = f.key) instanceof TreeBin) { TreeBin t = (TreeBin)fk; t.acquire(0); try { if (tabAt(tab, i) == f) { TreeBin lt = new TreeBin(); TreeBin ht = new TreeBin(); int lc = 0, hc = 0; for (Node e = t.first; e != null; e = e.next) { int h = e.hash; Object k = e.key; V v = e.val; if ((h & n) == 0) { ++lc; lt.putTreeNode(h, k, v); } else { ++hc; ht.putTreeNode(h, k, v); } } Node ln, hn; // throw away trees if too small if (lc < TREE_THRESHOLD) { ln = null; for (Node p = lt.first; p != null; p = p.next) ln = new Node(p.hash, p.key, p.val, ln); } else ln = new Node(MOVED, lt, null, null); setTabAt(nextTab, i, ln); if (hc < TREE_THRESHOLD) { hn = null; for (Node p = ht.first; p != null; p = p.next) hn = new Node(p.hash, p.key, p.val, hn); } else hn = new Node(MOVED, ht, null, null); setTabAt(nextTab, i + n, hn); setTabAt(tab, i, fwd); advance = true; } } finally { t.release(0); } } else advance = true; // already processed } } /* ---------------- Counter support -------------- */ 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, CounterHashCode hc, boolean wasUncontended) { int h; if (hc == null) { hc = new CounterHashCode(); int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT); h = hc.code = (s == 0) ? 1 : s; // Avoid zero threadCounterHashCode.set(hc); } else h = hc.code; 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 (counterBusy == 0) { // Try to attach new Cell CounterCell r = new CounterCell(x); // Optimistic create if (counterBusy == 0 && U.compareAndSwapInt(this, COUNTERBUSY, 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 { counterBusy = 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.compareAndSwapLong(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 (counterBusy == 0 && U.compareAndSwapInt(this, COUNTERBUSY, 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 { counterBusy = 0; } collide = false; continue; // Retry with expanded table } h ^= h << 13; // Rehash h ^= h >>> 17; h ^= h << 5; } else if (counterBusy == 0 && counterCells == as && U.compareAndSwapInt(this, COUNTERBUSY, 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 { counterBusy = 0; } if (init) break; } else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x)) break; // Fall back on using base } hc.code = h; // Record index for next time } /* ----------------Table Traversal -------------- */ /** * Encapsulates traversal for methods such as containsValue; also * serves as a base class for other iterators and bulk tasks. * * At each step, the iterator snapshots the key ("nextKey") and * value ("nextVal") of a valid node (i.e., one that, at point of * snapshot, has a non-null user value). Because val fields can * change (including to null, indicating deletion), field nextVal * might not be accurate at point of use, but still maintains the * weak consistency property of holding a value that was once * valid. To support iterator.remove, the nextKey field is not * updated (nulled out) when the iterator cannot advance. * * Internal traversals directly access these fields, as in: * {@code while (it.advance() != null) { process(it.nextKey); }} * * Exported iterators must track whether the iterator has advanced * (in hasNext vs next) (by setting/checking/nulling field * nextVal), and then extract key, value, or key-value pairs as * return values of next(). * * The iterator visits once each still-valid node that was * reachable upon iterator construction. It might miss some that * 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. * * This class extends CountedCompleter to streamline parallel * iteration in bulk operations. This adds only a few fields of * space overhead, which is small enough in cases where it is not * needed to not worry about it. Because CountedCompleter is * Serializable, but iterators need not be, we need to add warning * suppressions. */ @SuppressWarnings("serial") static class Traverser extends CountedCompleter { final ConcurrentHashMapV8 map; Node next; // the next entry to use Object nextKey; // cached key field of next V nextVal; // cached val field of next Node[] tab; // current table; updated if resized int index; // index of bin to use next int baseIndex; // current index of initial table int baseLimit; // index bound for initial table int baseSize; // initial table size int batch; // split control /** Creates iterator for all entries in the table. */ Traverser(ConcurrentHashMapV8 map) { this.map = map; } /** Creates iterator for split() methods and task constructors */ Traverser(ConcurrentHashMapV8 map, Traverser it, int batch) { super(it); this.batch = batch; if ((this.map = map) != null && it != null) { // split parent Node[] t; if ((t = it.tab) == null && (t = it.tab = map.table) != null) it.baseLimit = it.baseSize = t.length; this.tab = t; this.baseSize = it.baseSize; int hi = this.baseLimit = it.baseLimit; it.baseLimit = this.index = this.baseIndex = (hi + it.baseIndex + 1) >>> 1; } } /** * Advances next; returns nextVal or null if terminated. * See above for explanation. */ @SuppressWarnings("unchecked") final V advance() { Node e = next; V ev = null; outer: do { if (e != null) // advance past used/skipped node e = e.next; while (e == null) { // get to next non-null bin ConcurrentHashMapV8 m; Node[] t; int b, i, n; Object ek; // must use locals if ((t = tab) != null) n = t.length; else if ((m = map) != null && (t = tab = m.table) != null) n = baseLimit = baseSize = t.length; else break outer; if ((b = baseIndex) >= baseLimit || (i = index) < 0 || i >= n) break outer; if ((e = tabAt(t, i)) != null && e.hash < 0) { if ((ek = e.key) instanceof TreeBin) e = ((TreeBin)ek).first; else { tab = (Node[])ek; continue; // restarts due to null val } } // visit upper slots if present index = (i += baseSize) < n ? i : (baseIndex = b + 1); } nextKey = e.key; } while ((ev = e.val) == null); // skip deleted or special nodes next = e; return nextVal = ev; } public final void remove() { Object k = nextKey; if (k == null && (advance() == null || (k = nextKey) == null)) throw new IllegalStateException(); map.internalReplace(k, null, null); } public final boolean hasNext() { return nextVal != null || advance() != null; } public final boolean hasMoreElements() { return hasNext(); } public void compute() { } // default no-op CountedCompleter body /** * Returns a batch value > 0 if this task should (and must) be * split, if so, adding to pending count, and in any case * updating batch value. The initial batch value is approx * exp2 of the number of times (minus one) to split task by * two before executing leaf action. This value is faster to * compute and more convenient to use as a guide to splitting * than is the depth, since it is used while dividing by two * anyway. */ final int preSplit() { ConcurrentHashMapV8 m; int b; Node[] t; ForkJoinPool pool; if ((b = batch) < 0 && (m = map) != null) { // force initialization if ((t = tab) == null && (t = tab = m.table) != null) baseLimit = baseSize = t.length; if (t != null) { long n = m.sumCount(); int par = ((pool = getPool()) == null) ? ForkJoinPool.getCommonPoolParallelism() : pool.getParallelism(); int sp = par << 3; // slack of 8 b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp; } } b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1); if ((batch = b) > 0) addToPendingCount(1); return b; } } /* ---------------- Public operations -------------- */ /** * Creates a new, empty map with the default initial table size (16). */ public ConcurrentHashMapV8() { } /** * 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 ConcurrentHashMapV8(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 ConcurrentHashMapV8(Map m) { this.sizeCtl = DEFAULT_CAPACITY; internalPutAll(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 ConcurrentHashMapV8(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 ConcurrentHashMapV8(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; } /** * Creates a new {@link Set} backed by a ConcurrentHashMapV8 * from the given type to {@code Boolean.TRUE}. * * @return the new set */ public static KeySetView newKeySet() { return new KeySetView(new ConcurrentHashMapV8(), Boolean.TRUE); } /** * Creates a new {@link Set} backed by a ConcurrentHashMapV8 * from the given type to {@code Boolean.TRUE}. * * @param initialCapacity The implementation performs internal * sizing to accommodate this many elements. * @throws IllegalArgumentException if the initial capacity of * elements is negative * @return the new set */ public static KeySetView newKeySet(int initialCapacity) { return new KeySetView (new ConcurrentHashMapV8(initialCapacity), Boolean.TRUE); } /** * {@inheritDoc} */ public boolean isEmpty() { return sumCount() <= 0L; // ignore transient negative values } /** * {@inheritDoc} */ public int size() { long n = sumCount(); return ((n < 0L) ? 0 : (n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE : (int)n); } /** * Returns the number of mappings. This method should be used * instead of {@link #size} because a ConcurrentHashMapV8 may * contain more mappings than can be represented as an int. The * value returned is an estimate; the actual count may differ if * there are concurrent insertions or removals. * * @return the number of mappings */ public long mappingCount() { long n = sumCount(); return (n < 0L) ? 0L : n; // 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. * *

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) { return internalGet(key); } /** * Returns the value to which the specified key is mapped, * or the given defaultValue if this map contains no mapping for the key. * * @param key the key * @param defaultValue the value to return if this map contains * no mapping for the given key * @return the mapping for the key, if present; else the defaultValue * @throws NullPointerException if the specified key is null */ public V getValueOrDefault(Object key, V defaultValue) { V v; return (v = internalGet(key)) == null ? defaultValue : v; } /** * 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 internalGet(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(); V v; Traverser it = new Traverser(this); while ((v = it.advance()) != null) { if (v == value || value.equals(v)) return true; } return false; } /** * Legacy method testing if some key maps into the specified value * in this table. This method is identical in functionality to * {@link #containsValue}, 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 */ @Deprecated public boolean contains(Object value) { return containsValue(value); } /** * Maps the specified key to the specified value in this table. * Neither the key nor the value can be null. * *

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 internalPut(key, value, false); } /** * {@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 internalPut(key, value, true); } /** * 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 m) { internalPutAll(m); } /** * If the specified key is not already associated with a value, * computes its value using the given mappingFunction and enters * it into the map unless null. This is equivalent to *

 {@code
     * if (map.containsKey(key))
     *   return map.get(key);
     * value = mappingFunction.apply(key);
     * if (value != null)
     *   map.put(key, value);
     * return value;}
* * except that the action is performed atomically. If the * function returns {@code null} no mapping is recorded. If the * function itself throws an (unchecked) exception, the exception * is rethrown to its caller, and no mapping is recorded. Some * attempted update operations on this map by other threads may be * blocked while computation is in progress, so the computation * should be short and simple, and must not attempt to update any * other mappings of this Map. The most appropriate usage is to * construct a new object serving as an initial mapped value, or * memoized result, as in: * *
 {@code
     * map.computeIfAbsent(key, new Fun() {
     *   public V map(K k) { return new Value(f(k)); }});}
* * @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, Fun mappingFunction) { return internalComputeIfAbsent(key, mappingFunction); } /** * If the given key is present, computes a new mapping value given a key and * its current mapped value. This is equivalent to *
 {@code
     *   if (map.containsKey(key)) {
     *     value = remappingFunction.apply(key, map.get(key));
     *     if (value != null)
     *       map.put(key, value);
     *     else
     *       map.remove(key);
     *   }
     * }
* * except that the action is performed atomically. If the * function returns {@code null}, the mapping is removed. If the * function itself throws an (unchecked) exception, the exception * is rethrown to its caller, and the current mapping is left * unchanged. Some attempted update operations on this map by * other threads may be blocked while computation is in progress, * so the computation should be short and simple, and must not * attempt to update any other mappings of this Map. For example, * to either create or append new messages to a value mapping: * * @param key key with which the specified value is to be associated * @param remappingFunction the function to compute a value * @return the new value associated with the specified key, or null if none * @throws NullPointerException if the specified key or remappingFunction * is null * @throws IllegalStateException if the computation detectably * attempts a recursive update to this map that would * otherwise never complete * @throws RuntimeException or Error if the remappingFunction does so, * in which case the mapping is unchanged */ public V computeIfPresent (K key, BiFun remappingFunction) { return internalCompute(key, true, remappingFunction); } /** * Computes a new mapping value given a key and * its current mapped value (or {@code null} if there is no current * mapping). This is equivalent to *
 {@code
     *   value = remappingFunction.apply(key, map.get(key));
     *   if (value != null)
     *     map.put(key, value);
     *   else
     *     map.remove(key);
     * }
* * except that the action is performed atomically. If the * function returns {@code null}, the mapping is removed. If the * function itself throws an (unchecked) exception, the exception * is rethrown to its caller, and the current mapping is left * unchanged. Some attempted update operations on this map by * other threads may be blocked while computation is in progress, * so the computation should be short and simple, and must not * attempt to update any other mappings of this Map. For example, * to either create or append new messages to a value mapping: * *
 {@code
     * Map map = ...;
     * final String msg = ...;
     * map.compute(key, new BiFun() {
     *   public String apply(Key k, String v) {
     *    return (v == null) ? msg : v + msg;});}}
* * @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, BiFun remappingFunction) { return internalCompute(key, false, remappingFunction); } /** * If the specified key is not already associated * with a value, associate it with the given value. * Otherwise, replace the value with the results of * the given remapping function. This is equivalent to: *
 {@code
     *   if (!map.containsKey(key))
     *     map.put(value);
     *   else {
     *     newValue = remappingFunction.apply(map.get(key), value);
     *     if (value != null)
     *       map.put(key, value);
     *     else
     *       map.remove(key);
     *   }
     * }
* except that the action is performed atomically. If the * function returns {@code null}, the mapping is removed. If the * function itself throws an (unchecked) exception, the exception * is rethrown to its caller, and the current mapping is left * unchanged. Some attempted update operations on this map by * other threads may be blocked while computation is in progress, * so the computation should be short and simple, and must not * attempt to update any other mappings of this Map. */ public V merge (K key, V value, BiFun remappingFunction) { return internalMerge(key, value, remappingFunction); } /** * 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 internalReplace(key, null, null); } /** * {@inheritDoc} * * @throws NullPointerException if the specified key is null */ public boolean remove(Object key, Object value) { return value != null && internalReplace(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 internalReplace(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 internalReplace(key, value, null); } /** * Removes all of the mappings from this map. */ public void clear() { internalClear(); } /** * 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. * * @return the set view */ public KeySetView keySet() { KeySetView ks = keySet; return (ks != null) ? ks : (keySet = new KeySetView(this, null)); } /** * Returns a {@link Set} view of the keys in this map, using the * given common mapped value for any additions (i.e., {@link * Collection#add} and {@link Collection#addAll}). This is of * course only appropriate if it is acceptable to use the same * value for all additions from this view. * * @param mappedValue the mapped value to use for any additions * @return the set view * @throws NullPointerException if the mappedValue is null */ public KeySetView keySet(V mappedValue) { if (mappedValue == null) throw new NullPointerException(); return new KeySetView(this, mappedValue); } /** * Returns a {@link Collection} view of the values contained in this map. * The collection is backed by the map, so changes to the map are * reflected in the collection, and vice-versa. */ public ValuesView values() { ValuesView vs = values; return (vs != null) ? vs : (values = new ValuesView(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. It does not support the {@code add} or * {@code addAll} operations. * *

The view's {@code iterator} is a "weakly consistent" iterator * that will never throw {@link ConcurrentModificationException}, * and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) * reflect any modifications subsequent to construction. */ public Set> entrySet() { EntrySetView es = entrySet; return (es != null) ? es : (entrySet = new EntrySetView(this)); } /** * Returns an enumeration of the keys in this table. * * @return an enumeration of the keys in this table * @see #keySet() */ public Enumeration keys() { return new KeyIterator(this); } /** * Returns an enumeration of the values in this table. * * @return an enumeration of the values in this table * @see #values() */ public Enumeration elements() { return new ValueIterator(this); } /** * Returns a partitionable iterator of the keys in this map. * * @return a partitionable iterator of the keys in this map */ public Spliterator keySpliterator() { return new KeyIterator(this); } /** * Returns a partitionable iterator of the values in this map. * * @return a partitionable iterator of the values in this map */ public Spliterator valueSpliterator() { return new ValueIterator(this); } /** * Returns a partitionable iterator of the entries in this map. * * @return a partitionable iterator of the entries in this map */ public Spliterator> entrySpliterator() { return new EntryIterator(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; Traverser it = new Traverser(this); V v; while ((v = it.advance()) != null) { h += it.nextKey.hashCode() ^ v.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() { Traverser it = new Traverser(this); StringBuilder sb = new StringBuilder(); sb.append('{'); V v; if ((v = it.advance()) != null) { for (;;) { Object k = it.nextKey; sb.append(k == this ? "(this Map)" : k); sb.append('='); sb.append(v == this ? "(this Map)" : v); if ((v = 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; Traverser it = new Traverser(this); V val; while ((val = it.advance()) != null) { Object v = m.get(it.nextKey); 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 = internalGet(mk)) == null || (mv != v && !mv.equals(v))) return false; } } return true; } /* ----------------Iterators -------------- */ @SuppressWarnings("serial") static final class KeyIterator extends Traverser implements Spliterator, Enumeration { KeyIterator(ConcurrentHashMapV8 map) { super(map); } KeyIterator(ConcurrentHashMapV8 map, Traverser it) { super(map, it, -1); } public KeyIterator split() { if (nextKey != null) throw new IllegalStateException(); return new KeyIterator(map, this); } @SuppressWarnings("unchecked") public final K next() { if (nextVal == null && advance() == null) throw new NoSuchElementException(); Object k = nextKey; nextVal = null; return (K) k; } public final K nextElement() { return next(); } } @SuppressWarnings("serial") static final class ValueIterator extends Traverser implements Spliterator, Enumeration { ValueIterator(ConcurrentHashMapV8 map) { super(map); } ValueIterator(ConcurrentHashMapV8 map, Traverser it) { super(map, it, -1); } public ValueIterator split() { if (nextKey != null) throw new IllegalStateException(); return new ValueIterator(map, this); } public final V next() { V v; if ((v = nextVal) == null && (v = advance()) == null) throw new NoSuchElementException(); nextVal = null; return v; } public final V nextElement() { return next(); } } @SuppressWarnings("serial") static final class EntryIterator extends Traverser implements Spliterator> { EntryIterator(ConcurrentHashMapV8 map) { super(map); } EntryIterator(ConcurrentHashMapV8 map, Traverser it) { super(map, it, -1); } public EntryIterator split() { if (nextKey != null) throw new IllegalStateException(); return new EntryIterator(map, this); } @SuppressWarnings("unchecked") public final Map.Entry next() { V v; if ((v = nextVal) == null && (v = advance()) == null) throw new NoSuchElementException(); Object k = nextKey; nextVal = null; return new MapEntry((K)k, v, map); } } /** * Exported Entry for iterators */ static final class MapEntry implements Map.Entry { final K key; // non-null V val; // non-null final ConcurrentHashMapV8 map; MapEntry(K key, V val, ConcurrentHashMapV8 map) { this.key = key; this.val = val; this.map = map; } public final K getKey() { return key; } public final V getValue() { return val; } public final int hashCode() { return key.hashCode() ^ val.hashCode(); } public final String toString(){ return key + "=" + val; } public final 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 final V setValue(V value) { if (value == null) throw new NullPointerException(); V v = val; val = value; map.put(key, value); return v; } } /** * Returns exportable snapshot entry for the given key and value * when write-through can't or shouldn't be used. */ static AbstractMap.SimpleEntry entryFor(K k, V v) { return new AbstractMap.SimpleEntry(k, v); } /* ---------------- Serialization Support -------------- */ /** * Stripped-down version of helper class used in previous version, * declared for the sake of serialization compatibility */ static class Segment implements Serializable { private static final long serialVersionUID = 2249069246763182397L; final float loadFactor; Segment(float lf) { this.loadFactor = lf; } } /** * Saves the state of the {@code ConcurrentHashMapV8} instance to a * stream (i.e., serializes it). * @param s the stream * @serialData * the key (Object) and value (Object) * for each key-value mapping, followed by a null pair. * The key-value mappings are emitted in no particular order. */ @SuppressWarnings("unchecked") private void writeObject (java.io.ObjectOutputStream s) throws java.io.IOException { if (segments == null) { // for serialization compatibility segments = (Segment[]) new Segment[DEFAULT_CONCURRENCY_LEVEL]; for (int i = 0; i < segments.length; ++i) segments[i] = new Segment(LOAD_FACTOR); } s.defaultWriteObject(); Traverser it = new Traverser(this); V v; while ((v = it.advance()) != null) { s.writeObject(it.nextKey); s.writeObject(v); } s.writeObject(null); s.writeObject(null); segments = null; // throw away } /** * Reconstitutes the instance from a stream (that is, deserializes it). * @param s the stream */ @SuppressWarnings("unchecked") private void readObject (java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { s.defaultReadObject(); this.segments = null; // unneeded // Create all nodes, then place in table once size is known long size = 0L; Node p = null; for (;;) { K k = (K) s.readObject(); V v = (V) s.readObject(); if (k != null && v != null) { int h = spread(k.hashCode()); p = new Node(h, k, v, p); ++size; } else break; } if (p != null) { boolean init = false; int n; if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) n = MAXIMUM_CAPACITY; else { int sz = (int)size; n = tableSizeFor(sz + (sz >>> 1) + 1); } int sc = sizeCtl; boolean collide = false; if (n > sc && U.compareAndSwapInt(this, SIZECTL, sc, -1)) { try { if (table == null) { init = true; @SuppressWarnings("rawtypes") Node[] rt = new Node[n]; Node[] tab = (Node[])rt; int mask = n - 1; while (p != null) { int j = p.hash & mask; Node next = p.next; Node q = p.next = tabAt(tab, j); setTabAt(tab, j, p); if (!collide && q != null && q.hash == p.hash) collide = true; p = next; } table = tab; addCount(size, -1); sc = n - (n >>> 2); } } finally { sizeCtl = sc; } if (collide) { // rescan and convert to TreeBins Node[] tab = table; for (int i = 0; i < tab.length; ++i) { int c = 0; for (Node e = tabAt(tab, i); e != null; e = e.next) { if (++c > TREE_THRESHOLD && (e.key instanceof Comparable)) { replaceWithTreeBin(tab, i, e.key); break; } } } } } if (!init) { // Can only happen if unsafely published. while (p != null) { internalPut((K)p.key, p.val, false); p = p.next; } } } } // ------------------------------------------------------- // Sams /** Interface describing a void action of one argument */ public interface Action { void apply(A a); } /** Interface describing a void action of two arguments */ public interface BiAction { void apply(A a, B b); } /** Interface describing a function of one argument */ public interface Fun { T apply(A a); } /** Interface describing a function of two arguments */ public interface BiFun { T apply(A a, B b); } /** Interface describing a function of no arguments */ public interface Generator { T apply(); } /** Interface describing a function mapping its argument to a double */ public interface ObjectToDouble { double apply(A a); } /** Interface describing a function mapping its argument to a long */ public interface ObjectToLong { long apply(A a); } /** Interface describing a function mapping its argument to an int */ public interface ObjectToInt {int apply(A a); } /** Interface describing a function mapping two arguments to a double */ public interface ObjectByObjectToDouble { double apply(A a, B b); } /** Interface describing a function mapping two arguments to a long */ public interface ObjectByObjectToLong { long apply(A a, B b); } /** Interface describing a function mapping two arguments to an int */ public interface ObjectByObjectToInt {int apply(A a, B b); } /** Interface describing a function mapping a double to a double */ public interface DoubleToDouble { double apply(double a); } /** Interface describing a function mapping a long to a long */ public interface LongToLong { long apply(long a); } /** Interface describing a function mapping an int to an int */ public interface IntToInt { int apply(int a); } /** Interface describing a function mapping two doubles to a double */ public interface DoubleByDoubleToDouble { double apply(double a, double b); } /** Interface describing a function mapping two longs to a long */ public interface LongByLongToLong { long apply(long a, long b); } /** Interface describing a function mapping two ints to an int */ public interface IntByIntToInt { int apply(int a, int b); } // ------------------------------------------------------- // Sequential bulk operations /** * Performs the given action for each (key, value). * * @param action the action */ @SuppressWarnings("unchecked") public void forEachSequentially (BiAction action) { if (action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; while ((v = it.advance()) != null) action.apply((K)it.nextKey, v); } /** * Performs the given action for each non-null transformation * of each (key, value). * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ @SuppressWarnings("unchecked") public void forEachSequentially (BiFun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = transformer.apply((K)it.nextKey, v)) != null) action.apply(u); } } /** * Returns a non-null result from applying the given search * function on each (key, value), or null if none. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each (key, value), or null if none */ @SuppressWarnings("unchecked") public U searchSequentially (BiFun searchFunction) { if (searchFunction == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = searchFunction.apply((K)it.nextKey, v)) != null) return u; } return null; } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, or null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ @SuppressWarnings("unchecked") public U reduceSequentially (BiFun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); U r = null, u; V v; while ((v = it.advance()) != null) { if ((u = transformer.apply((K)it.nextKey, v)) != null) r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ @SuppressWarnings("unchecked") public double reduceToDoubleSequentially (ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); double r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); return r; } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ @SuppressWarnings("unchecked") public long reduceToLongSequentially (ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); long r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); return r; } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ @SuppressWarnings("unchecked") public int reduceToIntSequentially (ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); int r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); return r; } /** * Performs the given action for each key. * * @param action the action */ @SuppressWarnings("unchecked") public void forEachKeySequentially (Action action) { if (action == null) throw new NullPointerException(); Traverser it = new Traverser(this); while (it.advance() != null) action.apply((K)it.nextKey); } /** * Performs the given action for each non-null transformation * of each key. * * @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 */ @SuppressWarnings("unchecked") public void forEachKeySequentially (Fun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); Traverser it = new Traverser(this); U u; while (it.advance() != null) { if ((u = transformer.apply((K)it.nextKey)) != null) action.apply(u); } ForkJoinTasks.forEachKey (this, transformer, action).invoke(); } /** * Returns a non-null result from applying the given search * function on each key, or null if none. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each key, or null if none */ @SuppressWarnings("unchecked") public U searchKeysSequentially (Fun searchFunction) { Traverser it = new Traverser(this); U u; while (it.advance() != null) { if ((u = searchFunction.apply((K)it.nextKey)) != null) return u; } return null; } /** * Returns the result of accumulating all keys using the given * reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all keys using the given * reducer to combine values, or null if none */ @SuppressWarnings("unchecked") public K reduceKeysSequentially (BiFun reducer) { if (reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); K r = null; while (it.advance() != null) { K u = (K)it.nextKey; r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, or * null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ @SuppressWarnings("unchecked") public U reduceKeysSequentially (Fun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); U r = null, u; while (it.advance() != null) { if ((u = transformer.apply((K)it.nextKey)) != null) r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ @SuppressWarnings("unchecked") public double reduceKeysToDoubleSequentially (ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); double r = basis; while (it.advance() != null) r = reducer.apply(r, transformer.apply((K)it.nextKey)); return r; } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ @SuppressWarnings("unchecked") public long reduceKeysToLongSequentially (ObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); long r = basis; while (it.advance() != null) r = reducer.apply(r, transformer.apply((K)it.nextKey)); return r; } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ @SuppressWarnings("unchecked") public int reduceKeysToIntSequentially (ObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); int r = basis; while (it.advance() != null) r = reducer.apply(r, transformer.apply((K)it.nextKey)); return r; } /** * Performs the given action for each value. * * @param action the action */ public void forEachValueSequentially(Action action) { if (action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; while ((v = it.advance()) != null) action.apply(v); } /** * Performs the given action for each non-null transformation * of each value. * * @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) */ public void forEachValueSequentially (Fun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = transformer.apply(v)) != null) action.apply(u); } } /** * Returns a non-null result from applying the given search * function on each value, or null if none. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each value, or null if none */ public U searchValuesSequentially (Fun searchFunction) { if (searchFunction == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = searchFunction.apply(v)) != null) return u; } return null; } /** * Returns the result of accumulating all values using the * given reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all values */ public V reduceValuesSequentially (BiFun reducer) { if (reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); V r = null; V v; while ((v = it.advance()) != null) r = (r == null) ? v : reducer.apply(r, v); return r; } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, or * null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public U reduceValuesSequentially (Fun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); U r = null, u; V v; while ((v = it.advance()) != null) { if ((u = transformer.apply(v)) != null) r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public double reduceValuesToDoubleSequentially (ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); double r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(v)); return r; } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public long reduceValuesToLongSequentially (ObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); long r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(v)); return r; } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public int reduceValuesToIntSequentially (ObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); int r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(v)); return r; } /** * Performs the given action for each entry. * * @param action the action */ @SuppressWarnings("unchecked") public void forEachEntrySequentially (Action> action) { if (action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; while ((v = it.advance()) != null) action.apply(entryFor((K)it.nextKey, v)); } /** * Performs the given action for each non-null transformation * of each entry. * * @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 */ @SuppressWarnings("unchecked") public void forEachEntrySequentially (Fun, ? extends U> transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null) action.apply(u); } } /** * Returns a non-null result from applying the given search * function on each entry, or null if none. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each entry, or null if none */ @SuppressWarnings("unchecked") public U searchEntriesSequentially (Fun, ? extends U> searchFunction) { if (searchFunction == null) throw new NullPointerException(); Traverser it = new Traverser(this); V v; U u; while ((v = it.advance()) != null) { if ((u = searchFunction.apply(entryFor((K)it.nextKey, v))) != null) return u; } return null; } /** * Returns the result of accumulating all entries using the * given reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all entries */ @SuppressWarnings("unchecked") public Map.Entry reduceEntriesSequentially (BiFun, Map.Entry, ? extends Map.Entry> reducer) { if (reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); Map.Entry r = null; V v; while ((v = it.advance()) != null) { Map.Entry u = entryFor((K)it.nextKey, v); r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * or null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ @SuppressWarnings("unchecked") public U reduceEntriesSequentially (Fun, ? extends U> transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); U r = null, u; V v; while ((v = it.advance()) != null) { if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null) r = (r == null) ? u : reducer.apply(r, u); } return r; } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ @SuppressWarnings("unchecked") public double reduceEntriesToDoubleSequentially (ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); double r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); return r; } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ @SuppressWarnings("unchecked") public long reduceEntriesToLongSequentially (ObjectToLong> transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); long r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); return r; } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ @SuppressWarnings("unchecked") public int reduceEntriesToIntSequentially (ObjectToInt> transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); Traverser it = new Traverser(this); int r = basis; V v; while ((v = it.advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); return r; } // Parallel bulk operations /** * Performs the given action for each (key, value). * * @param action the action */ public void forEachInParallel(BiAction action) { ForkJoinTasks.forEach (this, action).invoke(); } /** * Performs the given action for each non-null transformation * of each (key, value). * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ public void forEachInParallel (BiFun transformer, Action action) { ForkJoinTasks.forEach (this, transformer, action).invoke(); } /** * Returns a non-null result from applying the given search * function on each (key, value), or null if none. Upon * success, further element processing is suppressed and the * results of any other parallel invocations of the search * function are ignored. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each (key, value), or null if none */ public U searchInParallel (BiFun searchFunction) { return ForkJoinTasks.search (this, searchFunction).invoke(); } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, or null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ public U reduceInParallel (BiFun transformer, BiFun reducer) { return ForkJoinTasks.reduce (this, transformer, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ public double reduceToDoubleInParallel (ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { return ForkJoinTasks.reduceToDouble (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ public long reduceToLongInParallel (ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { return ForkJoinTasks.reduceToLong (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs */ public int reduceToIntInParallel (ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { return ForkJoinTasks.reduceToInt (this, transformer, basis, reducer).invoke(); } /** * Performs the given action for each key. * * @param action the action */ public void forEachKeyInParallel(Action action) { ForkJoinTasks.forEachKey (this, action).invoke(); } /** * Performs the given action for each non-null transformation * of each key. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ public void forEachKeyInParallel (Fun transformer, Action action) { ForkJoinTasks.forEachKey (this, transformer, action).invoke(); } /** * Returns a non-null result from applying the given search * function on each key, or null if none. Upon success, * further element processing is suppressed and the results of * any other parallel invocations of the search function are * ignored. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each key, or null if none */ public U searchKeysInParallel (Fun searchFunction) { return ForkJoinTasks.searchKeys (this, searchFunction).invoke(); } /** * Returns the result of accumulating all keys using the given * reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all keys using the given * reducer to combine values, or null if none */ public K reduceKeysInParallel (BiFun reducer) { return ForkJoinTasks.reduceKeys (this, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, or * null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ public U reduceKeysInParallel (Fun transformer, BiFun reducer) { return ForkJoinTasks.reduceKeys (this, transformer, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ public double reduceKeysToDoubleInParallel (ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { return ForkJoinTasks.reduceKeysToDouble (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ public long reduceKeysToLongInParallel (ObjectToLong transformer, long basis, LongByLongToLong reducer) { return ForkJoinTasks.reduceKeysToLong (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all keys using the given reducer to combine values, and * the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys */ public int reduceKeysToIntInParallel (ObjectToInt transformer, int basis, IntByIntToInt reducer) { return ForkJoinTasks.reduceKeysToInt (this, transformer, basis, reducer).invoke(); } /** * Performs the given action for each value. * * @param action the action */ public void forEachValueInParallel(Action action) { ForkJoinTasks.forEachValue (this, action).invoke(); } /** * Performs the given action for each non-null transformation * of each value. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) */ public void forEachValueInParallel (Fun transformer, Action action) { ForkJoinTasks.forEachValue (this, transformer, action).invoke(); } /** * Returns a non-null result from applying the given search * function on each value, or null if none. Upon success, * further element processing is suppressed and the results of * any other parallel invocations of the search function are * ignored. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each value, or null if none */ public U searchValuesInParallel (Fun searchFunction) { return ForkJoinTasks.searchValues (this, searchFunction).invoke(); } /** * Returns the result of accumulating all values using the * given reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all values */ public V reduceValuesInParallel (BiFun reducer) { return ForkJoinTasks.reduceValues (this, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, or * null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public U reduceValuesInParallel (Fun transformer, BiFun reducer) { return ForkJoinTasks.reduceValues (this, transformer, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public double reduceValuesToDoubleInParallel (ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { return ForkJoinTasks.reduceValuesToDouble (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public long reduceValuesToLongInParallel (ObjectToLong transformer, long basis, LongByLongToLong reducer) { return ForkJoinTasks.reduceValuesToLong (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all values using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values */ public int reduceValuesToIntInParallel (ObjectToInt transformer, int basis, IntByIntToInt reducer) { return ForkJoinTasks.reduceValuesToInt (this, transformer, basis, reducer).invoke(); } /** * Performs the given action for each entry. * * @param action the action */ public void forEachEntryInParallel(Action> action) { ForkJoinTasks.forEachEntry (this, action).invoke(); } /** * Performs the given action for each non-null transformation * of each entry. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ public void forEachEntryInParallel (Fun, ? extends U> transformer, Action action) { ForkJoinTasks.forEachEntry (this, transformer, action).invoke(); } /** * Returns a non-null result from applying the given search * function on each entry, or null if none. Upon success, * further element processing is suppressed and the results of * any other parallel invocations of the search function are * ignored. * * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each entry, or null if none */ public U searchEntriesInParallel (Fun, ? extends U> searchFunction) { return ForkJoinTasks.searchEntries (this, searchFunction).invoke(); } /** * Returns the result of accumulating all entries using the * given reducer to combine values, or null if none. * * @param reducer a commutative associative combining function * @return the result of accumulating all entries */ public Map.Entry reduceEntriesInParallel (BiFun, Map.Entry, ? extends Map.Entry> reducer) { return ForkJoinTasks.reduceEntries (this, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * or null if none. * * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ public U reduceEntriesInParallel (Fun, ? extends U> transformer, BiFun reducer) { return ForkJoinTasks.reduceEntries (this, transformer, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ public double reduceEntriesToDoubleInParallel (ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { return ForkJoinTasks.reduceEntriesToDouble (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ public long reduceEntriesToLongInParallel (ObjectToLong> transformer, long basis, LongByLongToLong reducer) { return ForkJoinTasks.reduceEntriesToLong (this, transformer, basis, reducer).invoke(); } /** * Returns the result of accumulating the given transformation * of all entries using the given reducer to combine values, * and the given basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries */ public int reduceEntriesToIntInParallel (ObjectToInt> transformer, int basis, IntByIntToInt reducer) { return ForkJoinTasks.reduceEntriesToInt (this, transformer, basis, reducer).invoke(); } /* ----------------Views -------------- */ /** * Base class for views. */ abstract static class CHMView { final ConcurrentHashMapV8 map; CHMView(ConcurrentHashMapV8 map) { this.map = map; } /** * Returns the map backing this view. * * @return the map backing this view */ public ConcurrentHashMapV8 getMap() { return map; } public final int size() { return map.size(); } public final boolean isEmpty() { return map.isEmpty(); } public final void clear() { map.clear(); } // implementations below rely on concrete classes supplying these public abstract Iterator iterator(); public abstract boolean contains(Object o); public abstract boolean remove(Object o); private static final String oomeMsg = "Required array size too large"; public final Object[] toArray() { long sz = map.mappingCount(); if (sz > (long)(MAX_ARRAY_SIZE)) throw new OutOfMemoryError(oomeMsg); int n = (int)sz; Object[] r = new Object[n]; int i = 0; Iterator it = iterator(); while (it.hasNext()) { if (i == n) { if (n >= MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); 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++] = it.next(); } return (i == n) ? r : Arrays.copyOf(r, i); } @SuppressWarnings("unchecked") public final T[] toArray(T[] a) { long sz = map.mappingCount(); if (sz > (long)(MAX_ARRAY_SIZE)) throw new OutOfMemoryError(oomeMsg); 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; Iterator it = iterator(); while (it.hasNext()) { if (i == n) { if (n >= MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); 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)it.next(); } if (a == r && i < n) { r[i] = null; // null-terminate return r; } return (i == n) ? r : Arrays.copyOf(r, i); } public final int hashCode() { int h = 0; for (Iterator it = iterator(); it.hasNext();) h += it.next().hashCode(); return h; } public final String toString() { StringBuilder sb = new StringBuilder(); sb.append('['); Iterator 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 (Iterator it = c.iterator(); it.hasNext();) { Object e = it.next(); if (e == null || !contains(e)) return false; } } return true; } public final boolean removeAll(Collection c) { boolean modified = false; for (Iterator it = iterator(); it.hasNext();) { if (c.contains(it.next())) { it.remove(); modified = true; } } return modified; } public final boolean retainAll(Collection c) { boolean modified = false; for (Iterator it = iterator(); it.hasNext();) { if (!c.contains(it.next())) { it.remove(); modified = true; } } return modified; } } /** * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in * which additions may optionally be enabled by mapping to a * common value. This class cannot be directly instantiated. See * {@link #keySet()}, {@link #keySet(Object)}, {@link #newKeySet()}, * {@link #newKeySet(int)}. */ public static class KeySetView extends CHMView implements Set, java.io.Serializable { private static final long serialVersionUID = 7249069246763182397L; private final V value; KeySetView(ConcurrentHashMapV8 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; } // implement Set API public boolean contains(Object o) { return map.containsKey(o); } public boolean remove(Object o) { return map.remove(o) != null; } /** * Returns a "weakly consistent" iterator that will never * throw {@link ConcurrentModificationException}, and * guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not * guaranteed to) reflect any modifications subsequent to * construction. * * @return an iterator over the keys of this map */ public Iterator iterator() { return new KeyIterator(map); } public boolean add(K e) { V v; if ((v = value) == null) throw new UnsupportedOperationException(); return map.internalPut(e, v, true) == null; } public boolean addAll(Collection c) { boolean added = false; V v; if ((v = value) == null) throw new UnsupportedOperationException(); for (K e : c) { if (map.internalPut(e, v, true) == null) added = true; } return added; } public boolean equals(Object o) { Set c; return ((o instanceof Set) && ((c = (Set)o) == this || (containsAll(c) && c.containsAll(this)))); } } /** * A view of a ConcurrentHashMapV8 as a {@link Collection} of * values, in which additions are disabled. This class cannot be * directly instantiated. See {@link #values()}. * *

The view's {@code iterator} is a "weakly consistent" iterator * that will never throw {@link ConcurrentModificationException}, * and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) * reflect any modifications subsequent to construction. */ public static final class ValuesView extends CHMView implements Collection { ValuesView(ConcurrentHashMapV8 map) { super(map); } public final boolean contains(Object o) { return map.containsValue(o); } public final boolean remove(Object o) { if (o != null) { Iterator it = new ValueIterator(map); while (it.hasNext()) { if (o.equals(it.next())) { it.remove(); return true; } } } return false; } /** * Returns a "weakly consistent" iterator that will never * throw {@link ConcurrentModificationException}, and * guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not * guaranteed to) reflect any modifications subsequent to * construction. * * @return an iterator over the values of this map */ public final Iterator iterator() { return new ValueIterator(map); } public final boolean add(V e) { throw new UnsupportedOperationException(); } public final boolean addAll(Collection c) { throw new UnsupportedOperationException(); } } /** * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value) * entries. This class cannot be directly instantiated. See * {@link #entrySet()}. */ public static final class EntrySetView extends CHMView implements Set> { EntrySetView(ConcurrentHashMapV8 map) { super(map); } public final 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 final 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)); } /** * Returns a "weakly consistent" iterator that will never * throw {@link ConcurrentModificationException}, and * guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not * guaranteed to) reflect any modifications subsequent to * construction. * * @return an iterator over the entries of this map */ public final Iterator> iterator() { return new EntryIterator(map); } public final boolean add(Entry e) { return map.internalPut(e.getKey(), e.getValue(), false) == null; } public final boolean addAll(Collection> c) { boolean added = false; for (Entry e : c) { if (add(e)) added = true; } return added; } public boolean equals(Object o) { Set c; return ((o instanceof Set) && ((c = (Set)o) == this || (containsAll(c) && c.containsAll(this)))); } } // --------------------------------------------------------------------- /** * Predefined tasks for performing bulk parallel operations on * ConcurrentHashMapV8s. These tasks follow the forms and rules used * for bulk operations. Each method has the same name, but returns * a task rather than invoking it. These methods may be useful in * custom applications such as submitting a task without waiting * for completion, using a custom pool, or combining with other * tasks. */ public static class ForkJoinTasks { private ForkJoinTasks() {} /** * Returns a task that when invoked, performs the given * action for each (key, value) * * @param map the map * @param action the action * @return the task */ public static ForkJoinTask forEach (ConcurrentHashMapV8 map, BiAction action) { if (action == null) throw new NullPointerException(); return new ForEachMappingTask(map, null, -1, action); } /** * Returns a task that when invoked, performs the given * action for each non-null transformation of each (key, value) * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action * @return the task */ public static ForkJoinTask forEach (ConcurrentHashMapV8 map, BiFun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); return new ForEachTransformedMappingTask (map, null, -1, transformer, action); } /** * Returns a task that when invoked, returns a non-null result * from applying the given search function on each (key, * value), or null if none. Upon success, further element * processing is suppressed and the results of any other * parallel invocations of the search function are ignored. * * @param map the map * @param searchFunction a function returning a non-null * result on success, else null * @return the task */ public static ForkJoinTask search (ConcurrentHashMapV8 map, BiFun searchFunction) { if (searchFunction == null) throw new NullPointerException(); return new SearchMappingsTask (map, null, -1, searchFunction, new AtomicReference()); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all (key, value) pairs * using the given reducer to combine values, or null if none. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduce (ConcurrentHashMapV8 map, BiFun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceMappingsTask (map, null, -1, null, transformer, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all (key, value) pairs * using the given reducer to combine values, and the given * basis as an identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceToDouble (ConcurrentHashMapV8 map, ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceMappingsToDoubleTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all (key, value) pairs * using the given reducer to combine values, and the given * basis as an identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceToLong (ConcurrentHashMapV8 map, ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceMappingsToLongTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all (key, value) pairs * using the given reducer to combine values, and the given * basis as an identity value. * * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceToInt (ConcurrentHashMapV8 map, ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceMappingsToIntTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, performs the given action * for each key. * * @param map the map * @param action the action * @return the task */ public static ForkJoinTask forEachKey (ConcurrentHashMapV8 map, Action action) { if (action == null) throw new NullPointerException(); return new ForEachKeyTask(map, null, -1, action); } /** * Returns a task that when invoked, performs the given action * for each non-null transformation of each key. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action * @return the task */ public static ForkJoinTask forEachKey (ConcurrentHashMapV8 map, Fun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); return new ForEachTransformedKeyTask (map, null, -1, transformer, action); } /** * Returns a task that when invoked, returns a non-null result * from applying the given search function on each key, or * null if none. Upon success, further element processing is * suppressed and the results of any other parallel * invocations of the search function are ignored. * * @param map the map * @param searchFunction a function returning a non-null * result on success, else null * @return the task */ public static ForkJoinTask searchKeys (ConcurrentHashMapV8 map, Fun searchFunction) { if (searchFunction == null) throw new NullPointerException(); return new SearchKeysTask (map, null, -1, searchFunction, new AtomicReference()); } /** * Returns a task that when invoked, returns the result of * accumulating all keys using the given reducer to combine * values, or null if none. * * @param map the map * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceKeys (ConcurrentHashMapV8 map, BiFun reducer) { if (reducer == null) throw new NullPointerException(); return new ReduceKeysTask (map, null, -1, null, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all keys using the given * reducer to combine values, or null if none. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceKeys (ConcurrentHashMapV8 map, Fun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceKeysTask (map, null, -1, null, transformer, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all keys using the given * reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceKeysToDouble (ConcurrentHashMapV8 map, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceKeysToDoubleTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all keys using the given * reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceKeysToLong (ConcurrentHashMapV8 map, ObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceKeysToLongTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all keys using the given * reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceKeysToInt (ConcurrentHashMapV8 map, ObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceKeysToIntTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, performs the given action * for each value. * * @param map the map * @param action the action */ public static ForkJoinTask forEachValue (ConcurrentHashMapV8 map, Action action) { if (action == null) throw new NullPointerException(); return new ForEachValueTask(map, null, -1, action); } /** * Returns a task that when invoked, performs the given action * for each non-null transformation of each value. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ public static ForkJoinTask forEachValue (ConcurrentHashMapV8 map, Fun transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); return new ForEachTransformedValueTask (map, null, -1, transformer, action); } /** * Returns a task that when invoked, returns a non-null result * from applying the given search function on each value, or * null if none. Upon success, further element processing is * suppressed and the results of any other parallel * invocations of the search function are ignored. * * @param map the map * @param searchFunction a function returning a non-null * result on success, else null * @return the task */ public static ForkJoinTask searchValues (ConcurrentHashMapV8 map, Fun searchFunction) { if (searchFunction == null) throw new NullPointerException(); return new SearchValuesTask (map, null, -1, searchFunction, new AtomicReference()); } /** * Returns a task that when invoked, returns the result of * accumulating all values using the given reducer to combine * values, or null if none. * * @param map the map * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceValues (ConcurrentHashMapV8 map, BiFun reducer) { if (reducer == null) throw new NullPointerException(); return new ReduceValuesTask (map, null, -1, null, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all values using the * given reducer to combine values, or null if none. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceValues (ConcurrentHashMapV8 map, Fun transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceValuesTask (map, null, -1, null, transformer, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all values using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceValuesToDouble (ConcurrentHashMapV8 map, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceValuesToDoubleTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all values using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceValuesToLong (ConcurrentHashMapV8 map, ObjectToLong transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceValuesToLongTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all values using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceValuesToInt (ConcurrentHashMapV8 map, ObjectToInt transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceValuesToIntTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, perform the given action * for each entry. * * @param map the map * @param action the action */ public static ForkJoinTask forEachEntry (ConcurrentHashMapV8 map, Action> action) { if (action == null) throw new NullPointerException(); return new ForEachEntryTask(map, null, -1, action); } /** * Returns a task that when invoked, perform the given action * for each non-null transformation of each entry. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action */ public static ForkJoinTask forEachEntry (ConcurrentHashMapV8 map, Fun, ? extends U> transformer, Action action) { if (transformer == null || action == null) throw new NullPointerException(); return new ForEachTransformedEntryTask (map, null, -1, transformer, action); } /** * Returns a task that when invoked, returns a non-null result * from applying the given search function on each entry, or * null if none. Upon success, further element processing is * suppressed and the results of any other parallel * invocations of the search function are ignored. * * @param map the map * @param searchFunction a function returning a non-null * result on success, else null * @return the task */ public static ForkJoinTask searchEntries (ConcurrentHashMapV8 map, Fun, ? extends U> searchFunction) { if (searchFunction == null) throw new NullPointerException(); return new SearchEntriesTask (map, null, -1, searchFunction, new AtomicReference()); } /** * Returns a task that when invoked, returns the result of * accumulating all entries using the given reducer to combine * values, or null if none. * * @param map the map * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask> reduceEntries (ConcurrentHashMapV8 map, BiFun, Map.Entry, ? extends Map.Entry> reducer) { if (reducer == null) throw new NullPointerException(); return new ReduceEntriesTask (map, null, -1, null, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all entries using the * given reducer to combine values, or null if none. * * @param map the map * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceEntries (ConcurrentHashMapV8 map, Fun, ? extends U> transformer, BiFun reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceEntriesTask (map, null, -1, null, transformer, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all entries using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceEntriesToDouble (ConcurrentHashMapV8 map, ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceEntriesToDoubleTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all entries using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceEntriesToLong (ConcurrentHashMapV8 map, ObjectToLong> transformer, long basis, LongByLongToLong reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceEntriesToLongTask (map, null, -1, null, transformer, basis, reducer); } /** * Returns a task that when invoked, returns the result of * accumulating the given transformation of all entries using the * given reducer to combine values, and the given basis as an * identity value. * * @param map the map * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the task */ public static ForkJoinTask reduceEntriesToInt (ConcurrentHashMapV8 map, ObjectToInt> transformer, int basis, IntByIntToInt reducer) { if (transformer == null || reducer == null) throw new NullPointerException(); return new MapReduceEntriesToIntTask (map, null, -1, null, transformer, basis, reducer); } } // ------------------------------------------------------- /* * 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 extends Traverser { final Action action; ForEachKeyTask (ConcurrentHashMapV8 m, Traverser p, int b, Action action) { super(m, p, b); this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Action action; if ((action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachKeyTask(map, this, b, action).fork(); while (advance() != null) action.apply((K)nextKey); propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachValueTask extends Traverser { final Action action; ForEachValueTask (ConcurrentHashMapV8 m, Traverser p, int b, Action action) { super(m, p, b); this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Action action; if ((action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachValueTask(map, this, b, action).fork(); V v; while ((v = advance()) != null) action.apply(v); propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachEntryTask extends Traverser { final Action> action; ForEachEntryTask (ConcurrentHashMapV8 m, Traverser p, int b, Action> action) { super(m, p, b); this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Action> action; if ((action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachEntryTask(map, this, b, action).fork(); V v; while ((v = advance()) != null) action.apply(entryFor((K)nextKey, v)); propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachMappingTask extends Traverser { final BiAction action; ForEachMappingTask (ConcurrentHashMapV8 m, Traverser p, int b, BiAction action) { super(m, p, b); this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final BiAction action; if ((action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachMappingTask(map, this, b, action).fork(); V v; while ((v = advance()) != null) action.apply((K)nextKey, v); propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachTransformedKeyTask extends Traverser { final Fun transformer; final Action action; ForEachTransformedKeyTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun transformer, Action action) { super(m, p, b); this.transformer = transformer; this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Fun transformer; final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachTransformedKeyTask (map, this, b, transformer, action).fork(); U u; while (advance() != null) { if ((u = transformer.apply((K)nextKey)) != null) action.apply(u); } propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachTransformedValueTask extends Traverser { final Fun transformer; final Action action; ForEachTransformedValueTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun transformer, Action action) { super(m, p, b); this.transformer = transformer; this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Fun transformer; final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachTransformedValueTask (map, this, b, transformer, action).fork(); V v; U u; while ((v = advance()) != null) { if ((u = transformer.apply(v)) != null) action.apply(u); } propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachTransformedEntryTask extends Traverser { final Fun, ? extends U> transformer; final Action action; ForEachTransformedEntryTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun, ? extends U> transformer, Action action) { super(m, p, b); this.transformer = transformer; this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final Fun, ? extends U> transformer; final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachTransformedEntryTask (map, this, b, transformer, action).fork(); V v; U u; while ((v = advance()) != null) { if ((u = transformer.apply(entryFor((K)nextKey, v))) != null) action.apply(u); } propagateCompletion(); } } } @SuppressWarnings("serial") static final class ForEachTransformedMappingTask extends Traverser { final BiFun transformer; final Action action; ForEachTransformedMappingTask (ConcurrentHashMapV8 m, Traverser p, int b, BiFun transformer, Action action) { super(m, p, b); this.transformer = transformer; this.action = action; } @SuppressWarnings("unchecked") public final void compute() { final BiFun transformer; final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { for (int b; (b = preSplit()) > 0;) new ForEachTransformedMappingTask (map, this, b, transformer, action).fork(); V v; U u; while ((v = advance()) != null) { if ((u = transformer.apply((K)nextKey, v)) != null) action.apply(u); } propagateCompletion(); } } } @SuppressWarnings("serial") static final class SearchKeysTask extends Traverser { final Fun searchFunction; final AtomicReference result; SearchKeysTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun searchFunction, AtomicReference result) { super(m, p, b); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } @SuppressWarnings("unchecked") public final void compute() { final Fun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { for (int b;;) { if (result.get() != null) return; if ((b = preSplit()) <= 0) break; new SearchKeysTask (map, this, b, searchFunction, result).fork(); } while (result.get() == null) { U u; if (advance() == null) { propagateCompletion(); break; } if ((u = searchFunction.apply((K)nextKey)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; } } } } } @SuppressWarnings("serial") static final class SearchValuesTask extends Traverser { final Fun searchFunction; final AtomicReference result; SearchValuesTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun searchFunction, AtomicReference result) { super(m, p, b); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } @SuppressWarnings("unchecked") public final void compute() { final Fun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { for (int b;;) { if (result.get() != null) return; if ((b = preSplit()) <= 0) break; new SearchValuesTask (map, this, b, searchFunction, result).fork(); } while (result.get() == null) { V v; U u; if ((v = advance()) == null) { propagateCompletion(); break; } if ((u = searchFunction.apply(v)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; } } } } } @SuppressWarnings("serial") static final class SearchEntriesTask extends Traverser { final Fun, ? extends U> searchFunction; final AtomicReference result; SearchEntriesTask (ConcurrentHashMapV8 m, Traverser p, int b, Fun, ? extends U> searchFunction, AtomicReference result) { super(m, p, b); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } @SuppressWarnings("unchecked") public final void compute() { final Fun, ? extends U> searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { for (int b;;) { if (result.get() != null) return; if ((b = preSplit()) <= 0) break; new SearchEntriesTask (map, this, b, searchFunction, result).fork(); } while (result.get() == null) { V v; U u; if ((v = advance()) == null) { propagateCompletion(); break; } if ((u = searchFunction.apply(entryFor((K)nextKey, v))) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); return; } } } } } @SuppressWarnings("serial") static final class SearchMappingsTask extends Traverser { final BiFun searchFunction; final AtomicReference result; SearchMappingsTask (ConcurrentHashMapV8 m, Traverser p, int b, BiFun searchFunction, AtomicReference result) { super(m, p, b); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } @SuppressWarnings("unchecked") public final void compute() { final BiFun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { for (int b;;) { if (result.get() != null) return; if ((b = preSplit()) <= 0) break; new SearchMappingsTask (map, this, b, searchFunction, result).fork(); } while (result.get() == null) { V v; U u; if ((v = advance()) == null) { propagateCompletion(); break; } if ((u = searchFunction.apply((K)nextKey, v)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; } } } } } @SuppressWarnings("serial") static final class ReduceKeysTask extends Traverser { final BiFun reducer; K result; ReduceKeysTask rights, nextRight; ReduceKeysTask (ConcurrentHashMapV8 m, Traverser p, int b, ReduceKeysTask nextRight, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.reducer = reducer; } public final K getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final BiFun reducer; if ((reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new ReduceKeysTask (map, this, b, rights, reducer)).fork(); K r = null; while (advance() != null) { K u = (K)nextKey; r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { ReduceKeysTask t = (ReduceKeysTask)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 extends Traverser { final BiFun reducer; V result; ReduceValuesTask rights, nextRight; ReduceValuesTask (ConcurrentHashMapV8 m, Traverser p, int b, ReduceValuesTask nextRight, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.reducer = reducer; } public final V getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final BiFun reducer; if ((reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new ReduceValuesTask (map, this, b, rights, reducer)).fork(); V r = null; V v; while ((v = advance()) != null) { V u = v; r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { ReduceValuesTask t = (ReduceValuesTask)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 extends Traverser> { final BiFun, Map.Entry, ? extends Map.Entry> reducer; Map.Entry result; ReduceEntriesTask rights, nextRight; ReduceEntriesTask (ConcurrentHashMapV8 m, Traverser p, int b, ReduceEntriesTask nextRight, BiFun, Map.Entry, ? extends Map.Entry> reducer) { super(m, p, b); this.nextRight = nextRight; this.reducer = reducer; } public final Map.Entry getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final BiFun, Map.Entry, ? extends Map.Entry> reducer; if ((reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new ReduceEntriesTask (map, this, b, rights, reducer)).fork(); Map.Entry r = null; V v; while ((v = advance()) != null) { Map.Entry u = entryFor((K)nextKey, v); r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { ReduceEntriesTask t = (ReduceEntriesTask)c, s = t.rights; while (s != null) { Map.Entry 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 extends Traverser { final Fun transformer; final BiFun reducer; U result; MapReduceKeysTask rights, nextRight; MapReduceKeysTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceKeysTask nextRight, Fun transformer, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final Fun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new MapReduceKeysTask (map, this, b, rights, transformer, reducer)).fork(); U r = null, u; while (advance() != null) { if ((u = transformer.apply((K)nextKey)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceKeysTask t = (MapReduceKeysTask)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 extends Traverser { final Fun transformer; final BiFun reducer; U result; MapReduceValuesTask rights, nextRight; MapReduceValuesTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceValuesTask nextRight, Fun transformer, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final Fun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new MapReduceValuesTask (map, this, b, rights, transformer, reducer)).fork(); U r = null, u; V v; while ((v = advance()) != null) { if ((u = transformer.apply(v)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceValuesTask t = (MapReduceValuesTask)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 extends Traverser { final Fun, ? extends U> transformer; final BiFun reducer; U result; MapReduceEntriesTask rights, nextRight; MapReduceEntriesTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceEntriesTask nextRight, Fun, ? extends U> transformer, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final Fun, ? extends U> transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new MapReduceEntriesTask (map, this, b, rights, transformer, reducer)).fork(); U r = null, u; V v; while ((v = advance()) != null) { if ((u = transformer.apply(entryFor((K)nextKey, v))) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceEntriesTask t = (MapReduceEntriesTask)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 extends Traverser { final BiFun transformer; final BiFun reducer; U result; MapReduceMappingsTask rights, nextRight; MapReduceMappingsTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceMappingsTask nextRight, BiFun transformer, BiFun reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final BiFun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { for (int b; (b = preSplit()) > 0;) (rights = new MapReduceMappingsTask (map, this, b, rights, transformer, reducer)).fork(); U r = null, u; V v; while ((v = advance()) != null) { if ((u = transformer.apply((K)nextKey, v)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceMappingsTask t = (MapReduceMappingsTask)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 extends Traverser { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceKeysToDoubleTask rights, nextRight; MapReduceKeysToDoubleTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceKeysToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceKeysToDoubleTask (map, this, b, rights, transformer, r, reducer)).fork(); while (advance() != null) r = reducer.apply(r, transformer.apply((K)nextKey)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceKeysToDoubleTask t = (MapReduceKeysToDoubleTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask extends Traverser { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceValuesToDoubleTask rights, nextRight; MapReduceValuesToDoubleTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceValuesToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceValuesToDoubleTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceValuesToDoubleTask t = (MapReduceValuesToDoubleTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask extends Traverser { final ObjectToDouble> transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceEntriesToDoubleTask rights, nextRight; MapReduceEntriesToDoubleTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceEntriesToDoubleTask nextRight, ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToDouble> transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceEntriesToDoubleTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, v))); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceEntriesToDoubleTask t = (MapReduceEntriesToDoubleTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask extends Traverser { final ObjectByObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceMappingsToDoubleTask rights, nextRight; MapReduceMappingsToDoubleTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceMappingsToDoubleTask nextRight, ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectByObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceMappingsToDoubleTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply((K)nextKey, v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceMappingsToDoubleTask t = (MapReduceMappingsToDoubleTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceKeysToLongTask extends Traverser { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceKeysToLongTask rights, nextRight; MapReduceKeysToLongTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceKeysToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceKeysToLongTask (map, this, b, rights, transformer, r, reducer)).fork(); while (advance() != null) r = reducer.apply(r, transformer.apply((K)nextKey)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceKeysToLongTask t = (MapReduceKeysToLongTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceValuesToLongTask extends Traverser { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceValuesToLongTask rights, nextRight; MapReduceValuesToLongTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceValuesToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceValuesToLongTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceValuesToLongTask t = (MapReduceValuesToLongTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask extends Traverser { final ObjectToLong> transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceEntriesToLongTask rights, nextRight; MapReduceEntriesToLongTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceEntriesToLongTask nextRight, ObjectToLong> transformer, long basis, LongByLongToLong reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToLong> transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceEntriesToLongTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, v))); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceEntriesToLongTask t = (MapReduceEntriesToLongTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask extends Traverser { final ObjectByObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceMappingsToLongTask rights, nextRight; MapReduceMappingsToLongTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceMappingsToLongTask nextRight, ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectByObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceMappingsToLongTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply((K)nextKey, v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceMappingsToLongTask t = (MapReduceMappingsToLongTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceKeysToIntTask extends Traverser { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceKeysToIntTask rights, nextRight; MapReduceKeysToIntTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceKeysToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceKeysToIntTask (map, this, b, rights, transformer, r, reducer)).fork(); while (advance() != null) r = reducer.apply(r, transformer.apply((K)nextKey)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceKeysToIntTask t = (MapReduceKeysToIntTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceValuesToIntTask extends Traverser { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceValuesToIntTask rights, nextRight; MapReduceValuesToIntTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceValuesToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceValuesToIntTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceValuesToIntTask t = (MapReduceValuesToIntTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask extends Traverser { final ObjectToInt> transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceEntriesToIntTask rights, nextRight; MapReduceEntriesToIntTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceEntriesToIntTask nextRight, ObjectToInt> transformer, int basis, IntByIntToInt reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectToInt> transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceEntriesToIntTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, v))); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceEntriesToIntTask t = (MapReduceEntriesToIntTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask extends Traverser { final ObjectByObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceMappingsToIntTask rights, nextRight; MapReduceMappingsToIntTask (ConcurrentHashMapV8 m, Traverser p, int b, MapReduceMappingsToIntTask nextRight, ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { super(m, p, b); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } @SuppressWarnings("unchecked") public final void compute() { final ObjectByObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; for (int b; (b = preSplit()) > 0;) (rights = new MapReduceMappingsToIntTask (map, this, b, rights, transformer, r, reducer)).fork(); V v; while ((v = advance()) != null) r = reducer.apply(r, transformer.apply((K)nextKey, v)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { MapReduceMappingsToIntTask t = (MapReduceMappingsToIntTask)c, s = t.rights; while (s != null) { t.result = reducer.apply(t.result, s.result); s = t.rights = s.nextRight; } } } } } // Unsafe mechanics private static final sun.misc.Unsafe U; private static final long SIZECTL; private static final long TRANSFERINDEX; private static final long TRANSFERORIGIN; private static final long BASECOUNT; private static final long COUNTERBUSY; private static final long CELLVALUE; private static final long ABASE; private static final int ASHIFT; static { try { U = getUnsafe(); Class k = ConcurrentHashMapV8.class; SIZECTL = U.objectFieldOffset (k.getDeclaredField("sizeCtl")); TRANSFERINDEX = U.objectFieldOffset (k.getDeclaredField("transferIndex")); TRANSFERORIGIN = U.objectFieldOffset (k.getDeclaredField("transferOrigin")); BASECOUNT = U.objectFieldOffset (k.getDeclaredField("baseCount")); COUNTERBUSY = U.objectFieldOffset (k.getDeclaredField("counterBusy")); Class ck = CounterCell.class; CELLVALUE = U.objectFieldOffset (ck.getDeclaredField("value")); Class sc = Node[].class; ABASE = U.arrayBaseOffset(sc); int scale = U.arrayIndexScale(sc); if ((scale & (scale - 1)) != 0) throw new Error("data type scale not a power of two"); ASHIFT = 31 - Integer.numberOfLeadingZeros(scale); } catch (Exception e) { throw new Error(e); } } /** * Returns a sun.misc.Unsafe. Suitable for use in a 3rd party package. * Replace with a simple call to Unsafe.getUnsafe when integrating * into a jdk. * * @return a sun.misc.Unsafe */ private static sun.misc.Unsafe getUnsafe() { try { return sun.misc.Unsafe.getUnsafe(); } catch (SecurityException tryReflectionInstead) {} try { return java.security.AccessController.doPrivileged (new java.security.PrivilegedExceptionAction() { public sun.misc.Unsafe run() throws Exception { Class k = sun.misc.Unsafe.class; for (java.lang.reflect.Field f : k.getDeclaredFields()) { f.setAccessible(true); Object x = f.get(null); if (k.isInstance(x)) return k.cast(x); } throw new NoSuchFieldError("the Unsafe"); }}); } catch (java.security.PrivilegedActionException e) { throw new RuntimeException("Could not initialize intrinsics", e.getCause()); } } }