--- jsr166/src/jsr166e/ConcurrentHashMapV8.java 2012/08/13 18:13:30 1.53 +++ jsr166/src/jsr166e/ConcurrentHashMapV8.java 2013/06/19 17:08:59 1.105 @@ -5,31 +5,29 @@ */ package jsr166e; -import jsr166e.LongAdder; + import jsr166e.ForkJoinPool; -import jsr166e.ForkJoinTask; -import java.util.Comparator; +import java.io.ObjectStreamField; +import java.io.Serializable; +import java.lang.reflect.ParameterizedType; +import java.lang.reflect.Type; 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.Comparator; +import java.util.ConcurrentModificationException; +import java.util.Enumeration; import java.util.HashMap; +import java.util.Hashtable; import java.util.Iterator; -import java.util.Enumeration; -import java.util.ConcurrentModificationException; +import java.util.Map; import java.util.NoSuchElementException; +import java.util.Set; import java.util.concurrent.ConcurrentMap; -import java.util.concurrent.ThreadLocalRandom; -import java.util.concurrent.locks.LockSupport; -import java.util.concurrent.locks.AbstractQueuedSynchronizer; import java.util.concurrent.atomic.AtomicReference; - -import java.io.Serializable; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.locks.LockSupport; +import java.util.concurrent.locks.ReentrantLock; /** * A hash table supporting full concurrency of retrievals and @@ -43,25 +41,28 @@ import java.io.Serializable; * 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 + *

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. 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. + * 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 + *

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 @@ -80,102 +81,200 @@ import java.io.Serializable; * 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. + * hash table. To ameliorate impact, when keys are {@link Comparable}, + * this class may use comparison order among keys to help break ties. + * + *

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. * *

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 + *

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

ConcurrentHashMapV8s support a set of sequential and parallel bulk + * operations that 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. Bulk operations on {@link java.util.Map.Entry} + * objects do not support method {@code setValue}. + * + *

+ * + *

These bulk operations accept a {@code parallelismThreshold} + * argument. Methods proceed sequentially if the current map size is + * estimated to be less than the given threshold. Using a value of + * {@code Long.MAX_VALUE} suppresses all parallelism. Using a value + * of {@code 1} results in maximal parallelism by partitioning into + * enough subtasks to fully utilize the {@link + * ForkJoinPool#commonPool()} that is used for all parallel + * computations. Normally, you would initially choose one of these + * extreme values, and then measure performance of using in-between + * values that trade off overhead versus throughput. + * + *

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. * - *

jsr166e note: This class is a candidate replacement for - * java.util.concurrent.ConcurrentHashMap. During transition, this - * class declares and uses nested functional interfaces with different - * names but the same forms as those expected for JDK8. - * * @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 { +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;
-     *   }
-     * }
-     * }
+ * An object for traversing and partitioning elements of a source. + * This interface provides a subset of the functionality of JDK8 + * java.util.Spliterator. */ - public static interface Spliterator extends Iterator { + public static interface ConcurrentHashMapSpliterator { /** - * 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 + * If possible, returns a new spliterator covering + * approximately one half of the elements, which will not be + * covered by this spliterator. Returns null if cannot be + * split. + */ + ConcurrentHashMapSpliterator trySplit(); + /** + * Returns an estimate of the number of elements covered by + * this Spliterator. */ - Spliterator split(); + long estimateSize(); + + /** Applies the action to each untraversed element */ + void forEachRemaining(Action action); + /** If an element remains, applies the action and returns true. */ + boolean tryAdvance(Action action); } + // 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 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 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); } + /* * Overview: * @@ -186,18 +285,21 @@ public class ConcurrentHashMapV8 * 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 fields - * can contain special values, they are defined using plain Object - * types. Similarly in turn, all internal methods that use them - * work off Object types. And similarly, so do the internal - * methods of auxiliary iterator and view classes. All public - * generic typed methods relay in/out of these internal methods, - * supplying null-checks and casts as needed. This also allows - * many of the public methods to be factored into a smaller number - * of internal methods (although sadly not so for the five - * 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. + * This map usually acts as a binned (bucketed) hash table. Each + * key-value mapping is held in a Node. Most nodes are instances + * of the basic Node class with hash, key, value, and next + * fields. However, various subclasses exist: TreeNodes are + * arranged in balanced trees, not lists. TreeBins hold the roots + * of sets of TreeNodes. ForwardingNodes are placed at the heads + * of bins during resizing. ReservationNodes are used as + * placeholders while establishing values in computeIfAbsent and + * related methods. The types TreeBin, ForwardingNode, and + * ReservationNode do not hold normal user keys, values, or + * hashes, and are readily distinguishable during search etc + * because they have negative hash fields and null key and value + * fields. (These special nodes are either uncommon or transient, + * so the impact of carrying around some unused fields is + * insignficant.) * * The table is lazily initialized to a power-of-two size upon the * first insertion. Each bin in the table normally contains a @@ -205,24 +307,12 @@ public class ConcurrentHashMapV8 * Table accesses require volatile/atomic reads, writes, and * CASes. Because there is no other way to arrange this without * adding further indirections, we use intrinsics - * (sun.misc.Unsafe) operations. The lists of nodes within bins - * are always accurately traversable under volatile reads, so long - * as lookups check hash code and non-nullness of value before - * checking key equality. - * - * We use the top two bits of Node hash fields for control - * purposes -- they are available anyway because of addressing - * constraints. As explained further below, these top bits are - * used as follows: - * 00 - Normal - * 01 - Locked - * 11 - Locked and may have a thread waiting for lock - * 10 - Node is a forwarding node - * - * The lower 30 bits of each Node's hash field contain a - * transformation of the key's hash code, except for forwarding - * nodes, for which the lower bits are zero (and so always have - * hash field == MOVED). + * (sun.misc.Unsafe) operations. + * + * We use the top (sign) bit of Node hash fields for control + * purposes -- it is available anyway because of addressing + * constraints. Nodes with negative hash fields are specially + * handled or ignored in map methods. * * Insertion (via put or its variants) of the first node in an * empty bin is performed by just CASing it to the bin. This is @@ -231,22 +321,15 @@ public class ConcurrentHashMapV8 * delete, and replace) require locks. We do not want to waste * the space required to associate a distinct lock object with * each bin, so instead use the first node of a bin list itself as - * a lock. Blocking support for these locks relies on the builtin - * "synchronized" monitors. However, we also need a tryLock - * construction, so we overlay these by using bits of the Node - * hash field for lock control (see above), and so normally use - * builtin monitors only for blocking and signalling using - * wait/notifyAll constructions. See Node.tryAwaitLock. + * 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. + * or the bin becomes invalidated (upon resizing). * * The main disadvantage of per-bin locks is that other update * operations on other nodes in a bin list protected by the same @@ -279,15 +362,12 @@ public class ConcurrentHashMapV8 * 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 + * designed to have identical hash codes or ones that differs only + * in masked-out high bits. So we use a secondary strategy that + * applies when the number of nodes in a bin exceeds a + * threshold. These TreeBins use a balanced tree to hold nodes (a + * specialized form of red-black trees), bounding search time to + * O(log N). Each search step in a TreeBin is at least twice as * slow as in a regular list, but given that N cannot exceed * (1<<64) (before running out of addresses) this bounds search * steps, lock hold times, etc, to reasonable constants (roughly @@ -298,43 +378,43 @@ public class ConcurrentHashMapV8 * iterators in the same way. * * The table is resized when occupancy exceeds a percentage - * threshold (nominally, 0.75, but see below). Only a single - * thread performs the resize (using field "sizeCtl", to arrange - * exclusion), but the table otherwise remains usable for reads - * and updates. Resizing proceeds by transferring bins, one by - * one, from the table to the next 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. However, unlike other - * cases, a transfer can skip a bin if it fails to acquire its - * lock, and revisit it later (unless it is a TreeBin). Method - * rebuild maintains a buffer of TRANSFER_BUFFER_SIZE bins that - * have been skipped because of failure to acquire a lock, and - * blocks only if none are available (i.e., only very rarely). - * The transfer operation must also ensure that all accessible - * bins in both the old and new table are usable by any traversal. - * When there are no lock acquisition failures, this is arranged - * simply by proceeding from the last bin (table.length - 1) up - * towards the first. Upon seeing a forwarding node, traversals - * (see class Iter) arrange to move to the new table - * without revisiting nodes. However, when any node is skipped - * during a transfer, all earlier table bins may have become - * visible, so are initialized with a reverse-forwarding node back - * to the old table until the new ones are established. (This - * sometimes requires transiently locking a forwarding node, which - * is possible under the above encoding.) These more expensive - * mechanics trigger only when necessary. + * 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) @@ -349,20 +429,52 @@ public class ConcurrentHashMapV8 * 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 LongAdder, which avoids - * contention on updates but can encounter cache thrashing if read - * too frequently during concurrent access. To avoid reading so - * often, resizing is attempted either when a bin lock is - * contended, or upon adding to a bin already holding two or more - * nodes (checked before adding in the xIfAbsent methods, after - * adding in others). 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). But this approximation has high - * variance for small table sizes, so we check on any collision - * for sizes <= 64. The bulk putAll operation further reduces - * contention by only committing count updates upon these size - * checks. + * The element count is maintained using a specialization of + * LongAdder. We need to incorporate a specialization rather than + * just use a LongAdder in order to access implicit + * contention-sensing that leads to creation of multiple + * CounterCells. The counter mechanics avoid contention on + * updates but can encounter cache thrashing if read too + * frequently during concurrent access. To avoid reading so often, + * resizing under contention is attempted only upon adding to a + * bin already holding two or more nodes. Under uniform hash + * distributions, the probability of this occurring at threshold + * is around 13%, meaning that only about 1 in 8 puts check + * threshold (and after resizing, many fewer do so). + * + * TreeBins use a special form of comparison for search and + * related operations (which is the main reason we cannot use + * existing collections such as TreeMaps). TreeBins contain + * Comparable elements, but may contain others, as well as + * elements that are Comparable but not necessarily Comparable + * for the same T, so we cannot invoke compareTo among them. To + * handle this, the tree is ordered primarily by hash value, then + * by Comparable.compareTo order if applicable. On lookup at a + * node, if elements are not comparable or compare as 0 then both + * left and right children may need to be searched in the case of + * tied hash values. (This corresponds to the full list search + * that would be necessary if all elements were non-Comparable and + * had tied hashes.) The red-black balancing code is updated from + * pre-jdk-collections + * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) + * based in turn on Cormen, Leiserson, and Rivest "Introduction to + * Algorithms" (CLR). + * + * TreeBins also require an additional locking mechanism. While + * list traversal is always possible by readers even during + * updates, tree traversal is not, mainly beause of tree-rotations + * that may change the root node and/or its linkages. TreeBins + * include a simple read-write lock mechanism parasitic on the + * main bin-synchronization strategy: Structural adjustments + * associated with an insertion or removal are already bin-locked + * (and so cannot conflict with other writers) but must wait for + * ongoing readers to finish. Since there can be only one such + * waiter, we use a simple scheme using a single "waiter" field to + * block writers. However, readers need never block. If the root + * lock is held, they proceed along the slow traversal path (via + * next-pointers) until the lock becomes available or the list is + * exhausted, whichever comes first. These cases are not fast, but + * maximize aggregate expected throughput. * * Maintaining API and serialization compatibility with previous * versions of this class introduces several oddities. Mainly: We @@ -372,6 +484,13 @@ public class ConcurrentHashMapV8 * time that we can guarantee to honor it.) We also declare an * unused "Segment" class that is instantiated in minimal form * only when serializing. + * + * This file is organized to make things a little easier to follow + * while reading than they might otherwise: First the main static + * declarations and utilities, then fields, then main public + * methods (with a few factorings of multiple public methods into + * internal ones), then sizing methods, trees, traversers, and + * bulk operations. */ /* ---------------- Constants -------------- */ @@ -413,1938 +532,269 @@ public class ConcurrentHashMapV8 private static final float LOAD_FACTOR = 0.75f; /** - * The buffer size for skipped bins during transfers. The - * value is arbitrary but should be large enough to avoid - * most locking stalls during resizes. - */ - private static final int TRANSFER_BUFFER_SIZE = 32; - - /** * The bin count threshold for using a tree rather than list for a - * bin. The value reflects the approximate break-even point for - * using tree-based operations. + * bin. Bins are converted to trees when adding an element to a + * bin with at least this many nodes. The value must be greater + * than 2, and should be at least 8 to mesh with assumptions in + * tree removal about conversion back to plain bins upon + * shrinkage. */ - private static final int TREE_THRESHOLD = 8; - - /* - * Encodings for special uses of Node hash fields. See above for - * explanation. - */ - static final int MOVED = 0x80000000; // hash field for forwarding nodes - static final int LOCKED = 0x40000000; // set/tested only as a bit - static final int WAITING = 0xc0000000; // both bits set/tested together - static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash - - /* ---------------- Fields -------------- */ + static final int TREEIFY_THRESHOLD = 8; /** - * The array of bins. Lazily initialized upon first insertion. - * Size is always a power of two. Accessed directly by iterators. + * The bin count threshold for untreeifying a (split) bin during a + * resize operation. Should be less than TREEIFY_THRESHOLD, and at + * most 6 to mesh with shrinkage detection under removal. */ - transient volatile Node[] table; + static final int UNTREEIFY_THRESHOLD = 6; /** - * The counter maintaining number of elements. + * The smallest table capacity for which bins may be treeified. + * (Otherwise the table is resized if too many nodes in a bin.) + * The value should be at least 4 * TREEIFY_THRESHOLD to avoid + * conflicts between resizing and treeification thresholds. */ - private transient final LongAdder counter; + static final int MIN_TREEIFY_CAPACITY = 64; /** - * Table initialization and resizing control. When negative, the - * table is being initialized or resized. 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. + * 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 transient volatile int sizeCtl; - - // views - private transient KeySet keySet; - private transient Values values; - private transient EntrySet entrySet; - - /** For serialization compatibility. Null unless serialized; see below */ - private Segment[] segments; - - /* ---------------- Table element access -------------- */ + private static final int MIN_TRANSFER_STRIDE = 16; /* - * 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. + * Encodings for Node hash fields. See above for explanation. */ - - static final Node tabAt(Node[] tab, int i) { // used by Iter - return (Node)UNSAFE.getObjectVolatile(tab, ((long)i< implements Map.Entry { + final int hash; + final K key; + volatile V val; + Node next; - Node(int hash, Object key, Object val, Node next) { + Node(int hash, K key, V val, Node next) { this.hash = hash; this.key = key; this.val = val; this.next = next; } - /** CompareAndSet the hash field */ - final boolean casHash(int cmp, int val) { - return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val); - } - - /** The number of spins before blocking for a lock */ - static final int MAX_SPINS = - Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1; - - /** - * Spins a while if LOCKED bit set and this node is the first - * of its bin, and then sets WAITING bits on hash field and - * blocks (once) if they are still set. It is OK for this - * method to return even if lock is not available upon exit, - * which enables these simple single-wait mechanics. - * - * The corresponding signalling operation is performed within - * callers: Upon detecting that WAITING has been set when - * unlocking lock (via a failed CAS from non-waiting LOCKED - * state), unlockers acquire the sync lock and perform a - * notifyAll. - */ - final void tryAwaitLock(Node[] tab, int i) { - if (tab != null && i >= 0 && i < tab.length) { // bounds check - int r = ThreadLocalRandom.current().nextInt(); // randomize spins - int spins = MAX_SPINS, h; - while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) { - if (spins >= 0) { - r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift - if (r >= 0 && --spins == 0) - Thread.yield(); // yield before block - } - else if (casHash(h, h | WAITING)) { - synchronized (this) { - if (tabAt(tab, i) == this && - (hash & WAITING) == WAITING) { - try { - wait(); - } catch (InterruptedException ie) { - Thread.currentThread().interrupt(); - } - } - else - notifyAll(); // possibly won race vs signaller - } - break; - } - } - } - } - - // Unsafe mechanics for casHash - private static final sun.misc.Unsafe UNSAFE; - private static final long hashOffset; - - static { - try { - UNSAFE = getUnsafe(); - Class k = Node.class; - hashOffset = UNSAFE.objectFieldOffset - (k.getDeclaredField("hash")); - } catch (Exception e) { - throw new Error(e); - } - } - } - - /* ---------------- 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, Object 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; - } - } - - /** - * Return the TreeNode (or null if not found) for the given key - * starting at given root. - */ - @SuppressWarnings("unchecked") // suppress Comparable cast warning - 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) { - dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName()); - TreeNode r = null, s = null, pl, pr; - if (dir >= 0) { - if ((pl = p.left) != null && h <= pl.hash) - s = pl; - } - 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; - p = (dir > 0) ? p.right : p.left; - } - return null; + 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 V setValue(V value) { + throw new UnsupportedOperationException(); } - /** - * Wrapper for getTreeNode used by CHM.get. Tries to obtain - * read-lock to call getTreeNode, but during failure to get - * lock, searches along next links. - */ - final Object getValue(int h, Object k) { - Node r = null; - int c = getState(); // Must read lock state first - for (Node e = first; e != null; e = e.next) { - if (c <= 0 && compareAndSetState(c, c - 1)) { - try { - r = getTreeNode(h, k, root); - } finally { - releaseShared(0); - } - break; - } - else if ((e.hash & HASH_BITS) == h && k.equals(e.key)) { - r = e; - break; - } - else - c = getState(); - } - return r == null ? null : r.val; + public final boolean equals(Object o) { + Object k, v, u; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == key || k.equals(key)) && + (v == (u = val) || v.equals(u))); } /** - * Finds or adds a node. - * @return null if added + * Virtualized support for map.get(); overridden in subclasses. */ - @SuppressWarnings("unchecked") // suppress Comparable cast warning - final TreeNode putTreeNode(int h, Object k, Object v) { - Class c = k.getClass(); - TreeNode pp = root, p = null; - int dir = 0; - while (pp != null) { // find existing node or leaf to insert at - int ph; Object pk; Class pc; - p = pp; - if ((ph = p.hash) == h) { - if ((pk = p.key) == k || k.equals(pk)) - return p; - if (c != (pc = pk.getClass()) || - !(k instanceof Comparable) || - (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) { - dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName()); - TreeNode r = null, s = null, pl, pr; - if (dir >= 0) { - if ((pl = p.left) != null && h <= pl.hash) - s = pl; - } - 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; + Node find(int h, Object k) { + Node e = this; + if (k != null) { + do { + K ek; + if (e.hash == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + } while ((e = e.next) != null); } return null; } - - /** - * 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 -------------- */ + /* ---------------- Static utilities -------------- */ /** - * Spreads higher bits to lower, and also forces top 2 bits to 0. - * Because the table uses power-of-two masking, sets of hashes - * that vary only in bits above the current mask will always - * collide. (Among known examples are sets of Float keys holding - * consecutive whole numbers in small tables.) To counter this, - * we apply a transform that spreads the impact of higher bits + * Spreads (XORs) higher bits of hash to lower and also forces top + * bit to 0. Because the table uses power-of-two masking, sets of + * hashes that vary only in bits above the current mask will + * always collide. (Among known examples are sets of Float keys + * holding consecutive whole numbers in small tables.) So we + * apply a transform that spreads the impact of higher bits * downward. There is a tradeoff between speed, utility, and * quality of bit-spreading. Because many common sets of hashes - * are already reasonably distributed 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. + * are already reasonably distributed (so don't benefit from + * spreading), and because we use trees to handle large sets of + * collisions in bins, we just XOR some shifted bits in the + * cheapest possible way to reduce systematic lossage, as well as + * to incorporate impact of the highest bits that would otherwise + * never be used in index calculations because of table bounds. */ - private static final int spread(int h) { - h ^= (h >>> 18) ^ (h >>> 12); - return (h ^ (h >>> 10)) & HASH_BITS; + static final int spread(int h) { + return (h ^ (h >>> 16)) & HASH_BITS; } /** - * Replaces a list bin with a tree bin. Call only when locked. - * Fails to replace if the given key is non-comparable or table - * is, or needs, resizing. + * Returns a power of two table size for the given desired capacity. + * See Hackers Delight, sec 3.2 */ - private final void replaceWithTreeBin(Node[] tab, int index, Object key) { - if ((key instanceof Comparable) && - (tab.length >= MAXIMUM_CAPACITY || counter.sum() < (long)sizeCtl)) { - TreeBin t = new TreeBin(); - for (Node e = tabAt(tab, index); e != null; e = e.next) - t.putTreeNode(e.hash & HASH_BITS, e.key, e.val); - setTabAt(tab, index, new Node(MOVED, t, null, null)); - } + 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; } - /* ---------------- Internal access and update methods -------------- */ - - /** Implementation for get and containsKey */ - private final Object internalGet(Object k) { - int h = spread(k.hashCode()); - retry: for (Node[] tab = table; tab != null;) { - Node e, p; Object ek, ev; int eh; // locals to read fields once - for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) { - if ((eh = e.hash) == MOVED) { - if ((ek = e.key) instanceof TreeBin) // search TreeBin - return ((TreeBin)ek).getValue(h, k); - else { // restart with new table - tab = (Node[])ek; - continue retry; - } + /** + * Returns x's Class if it is of the form "class C implements + * Comparable", else null. + */ + static Class comparableClassFor(Object x) { + if (x instanceof Comparable) { + Class c; Type[] ts, as; Type t; ParameterizedType p; + if ((c = x.getClass()) == String.class) // bypass checks + return c; + if ((ts = c.getGenericInterfaces()) != null) { + for (int i = 0; i < ts.length; ++i) { + if (((t = ts[i]) instanceof ParameterizedType) && + ((p = (ParameterizedType)t).getRawType() == + Comparable.class) && + (as = p.getActualTypeArguments()) != null && + as.length == 1 && as[0] == c) // type arg is c + return c; } - else if ((eh & HASH_BITS) == 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. + * Returns k.compareTo(x) if x matches kc (k's screened comparable + * class), else 0. */ - private final Object internalReplace(Object k, Object v, Object cv) { - int h = spread(k.hashCode()); - Object 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) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean validated = false; - boolean deleted = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - validated = true; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) { - Object pv = p.val; - if (cv == null || cv == pv || cv.equals(pv)) { - oldVal = pv; - if ((p.val = v) == null) { - deleted = true; - t.deleteTreeNode(p); - } - } - } - } - } finally { - t.release(0); - } - if (validated) { - if (deleted) - counter.add(-1L); - break; - } - } - else - tab = (Node[])fk; - } - else if ((fh & HASH_BITS) != h && f.next == null) // precheck - break; // rules out possible existence - else if ((fh & LOCKED) != 0) { - checkForResize(); // try resizing if can't get lock - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - boolean validated = false; - boolean deleted = false; - try { - if (tabAt(tab, i) == f) { - validated = true; - for (Node e = f, pred = null;;) { - Object ek, ev; - if ((e.hash & HASH_BITS) == 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; - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (validated) { - if (deleted) - counter.add(-1L); - break; - } - } - } - return oldVal; + @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable + static int compareComparables(Class kc, Object k, Object x) { + return (x == null || x.getClass() != kc ? 0 : + ((Comparable)k).compareTo(x)); } - /* - * Internal versions of the five insertion methods, each a - * little more complicated than the last. All have - * the same basic structure as the first (internalPut): - * 1. If table uninitialized, create - * 2. If bin empty, try to CAS new node - * 3. If bin stale, use new table - * 4. if bin converted to TreeBin, validate and relay to TreeBin methods - * 5. Lock and validate; if valid, scan and add or update - * - * The others interweave other checks and/or alternative actions: - * * Plain put checks for and performs resize after insertion. - * * putIfAbsent prescans for mapping without lock (and fails to add - * if present), which also makes pre-emptive resize checks worthwhile. - * * computeIfAbsent extends form used in putIfAbsent with additional - * mechanics to deal with, calls, potential exceptions and null - * returns from function call. - * * compute uses the same function-call mechanics, but without - * the prescans - * * putAll attempts to pre-allocate enough table space - * and more lazily performs count updates and checks. - * - * Someday when details settle down a bit more, it might be worth - * some factoring to reduce sprawl. - */ - - /** Implementation for put */ - private final Object internalPut(Object k, Object v) { - int h = spread(k.hashCode()); - int count = 0; - 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))) - break; // no lock when adding to empty bin - } - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - Object oldVal = null; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - count = 2; - TreeNode p = t.putTreeNode(h, k, v); - if (p != null) { - oldVal = p.val; - p.val = v; - } - } - } finally { - t.release(0); - } - if (count != 0) { - if (oldVal != null) - return oldVal; - break; - } - } - else - tab = (Node[])fk; - } - else if ((fh & LOCKED) != 0) { - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - Object oldVal = null; - try { // needed in case equals() throws - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - oldVal = ev; - e.val = v; - break; - } - Node last = e; - if ((e = e.next) == null) { - last.next = new Node(h, k, v, null); - if (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } finally { // unlock and signal if needed - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (oldVal != null) - return oldVal; - if (tab.length <= 64) - count = 2; - break; - } - } - } - counter.add(1L); - if (count > 1) - checkForResize(); - return null; - } - - /** Implementation for putIfAbsent */ - private final Object internalPutIfAbsent(Object k, Object v) { - int h = spread(k.hashCode()); - int count = 0; - for (Node[] tab = table;;) { - int i; Node f; int fh; Object fk, fv; - if (tab == null) - 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; - } - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - Object oldVal = null; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - count = 2; - TreeNode p = t.putTreeNode(h, k, v); - if (p != null) - oldVal = p.val; - } - } finally { - t.release(0); - } - if (count != 0) { - if (oldVal != null) - return oldVal; - break; - } - } - else - tab = (Node[])fk; - } - else if ((fh & HASH_BITS) == h && (fv = f.val) != null && - ((fk = f.key) == k || k.equals(fk))) - return fv; - else { - Node g = f.next; - if (g != null) { // at least 2 nodes -- search and maybe resize - for (Node e = g;;) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) - return ev; - if ((e = e.next) == null) { - checkForResize(); - break; - } - } - } - if (((fh = f.hash) & LOCKED) != 0) { - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) { - Object oldVal = null; - try { - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - oldVal = ev; - break; - } - Node last = e; - if ((e = e.next) == null) { - last.next = new Node(h, k, v, null); - if (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (oldVal != null) - return oldVal; - if (tab.length <= 64) - count = 2; - break; - } - } - } - } - counter.add(1L); - if (count > 1) - checkForResize(); - return null; - } + /* ---------------- Table element access -------------- */ - /** Implementation for computeIfAbsent */ - private final Object internalComputeIfAbsent(K k, - Fun mf) { - int h = spread(k.hashCode()); - Object val = null; - int count = 0; - for (Node[] tab = table;;) { - Node f; int i, fh; Object fk, fv; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - Node node = new Node(fh = h | LOCKED, k, null, null); - if (casTabAt(tab, i, null, node)) { - count = 1; - try { - if ((val = mf.apply(k)) != null) - node.val = val; - } finally { - if (val == null) - setTabAt(tab, i, null); - if (!node.casHash(fh, h)) { - node.hash = h; - synchronized (node) { node.notifyAll(); }; - } - } - } - if (count != 0) - break; - } - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean added = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - count = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) - val = p.val; - else if ((val = mf.apply(k)) != null) { - added = true; - count = 2; - t.putTreeNode(h, k, val); - } - } - } finally { - t.release(0); - } - if (count != 0) { - if (!added) - return val; - break; - } - } - else - tab = (Node[])fk; - } - else if ((fh & HASH_BITS) == h && (fv = f.val) != null && - ((fk = f.key) == k || k.equals(fk))) - return fv; - else { - Node g = f.next; - if (g != null) { - for (Node e = g;;) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) - return ev; - if ((e = e.next) == null) { - checkForResize(); - break; - } - } - } - if (((fh = f.hash) & LOCKED) != 0) { - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) { - boolean added = false; - try { - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == 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 (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - } - break; - } - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (!added) - return val; - if (tab.length <= 64) - count = 2; - break; - } - } - } - } - if (val != null) { - counter.add(1L); - if (count > 1) - checkForResize(); - } - return val; - } + /* + * Volatile access methods are used for table elements as well as + * elements of in-progress next table while resizing. All uses of + * the tab arguments must be null checked by callers. All callers + * also paranoically precheck that tab's length is not zero (or an + * equivalent check), thus ensuring that any index argument taking + * the form of a hash value anded with (length - 1) is a valid + * index. Note that, to be correct wrt arbitrary concurrency + * errors by users, these checks must operate on local variables, + * which accounts for some odd-looking inline assignments below. + * Note that calls to setTabAt always occur within locked regions, + * and so do not need full volatile semantics, but still require + * ordering to maintain concurrent readability. + */ - /** Implementation for compute */ @SuppressWarnings("unchecked") - private final Object internalCompute(K k, boolean onlyIfPresent, - BiFun mf) { - int h = spread(k.hashCode()); - Object val = null; - int delta = 0; - int count = 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(fh = h | LOCKED, k, null, null); - if (casTabAt(tab, i, null, node)) { - try { - count = 1; - if ((val = mf.apply(k, null)) != null) { - node.val = val; - delta = 1; - } - } finally { - if (delta == 0) - setTabAt(tab, i, null); - if (!node.casHash(fh, h)) { - node.hash = h; - synchronized (node) { node.notifyAll(); }; - } - } - } - if (count != 0) - break; - } - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - count = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - Object pv = (p == null) ? null : p.val; - if ((val = mf.apply(k, (V)pv)) != null) { - if (p != null) - p.val = val; - else { - count = 2; - delta = 1; - t.putTreeNode(h, k, val); - } - } - else if (p != null) { - delta = -1; - t.deleteTreeNode(p); - } - } - } finally { - t.release(0); - } - if (count != 0) - break; - } - else - tab = (Node[])fk; - } - else if ((fh & LOCKED) != 0) { - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - try { - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f, pred = null;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - val = mf.apply(k, (V)ev); - if (val != null) - e.val = val; - else { - delta = -1; - Node en = e.next; - if (pred != null) - pred.next = en; - else - setTabAt(tab, i, en); - } - break; - } - 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 (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - } - break; - } - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (tab.length <= 64) - count = 2; - break; - } - } - } - if (delta != 0) { - counter.add((long)delta); - if (count > 1) - checkForResize(); - } - return val; + static final Node tabAt(Node[] tab, int i) { + return (Node)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE); } - private final Object internalMerge(K k, V v, - BiFun mf) { - int h = spread(k.hashCode()); - Object val = null; - int delta = 0; - int count = 0; - for (Node[] tab = table;;) { - int i; Node f; int fh; Object fk, fv; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - if (casTabAt(tab, i, null, new Node(h, k, v, null))) { - delta = 1; - val = v; - break; - } - } - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - count = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - val = (p == null) ? v : mf.apply((V)p.val, v); - if (val != null) { - if (p != null) - p.val = val; - else { - count = 2; - delta = 1; - t.putTreeNode(h, k, val); - } - } - else if (p != null) { - delta = -1; - t.deleteTreeNode(p); - } - } - } finally { - t.release(0); - } - if (count != 0) - break; - } - else - tab = (Node[])fk; - } - else if ((fh & LOCKED) != 0) { - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - try { - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f, pred = null;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - val = mf.apply(v, (V)ev); - if (val != null) - e.val = val; - else { - delta = -1; - Node en = e.next; - if (pred != null) - pred.next = en; - else - setTabAt(tab, i, en); - } - break; - } - pred = e; - if ((e = e.next) == null) { - val = v; - pred.next = new Node(h, k, val, null); - delta = 1; - if (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (tab.length <= 64) - count = 2; - break; - } - } - } - if (delta != 0) { - counter.add((long)delta); - if (count > 1) - checkForResize(); - } - return val; + static final boolean casTabAt(Node[] tab, int i, + Node c, Node v) { + return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v); } - /** Implementation for putAll */ - 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; - 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) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean validated = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - validated = true; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) - p.val = v; - else { - t.putTreeNode(h, k, v); - ++delta; - } - } - } finally { - t.release(0); - } - if (validated) - break; - } - else - tab = (Node[])fk; - } - else if ((fh & LOCKED) != 0) { - counter.add(delta); - delta = 0L; - checkForResize(); - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - int count = 0; - try { - if (tabAt(tab, i) == f) { - count = 1; - for (Node e = f;; ++count) { - Object ek, ev; - if ((e.hash & HASH_BITS) == 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 (count >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (count != 0) { - if (count > 1) { - counter.add(delta); - delta = 0L; - checkForResize(); - } - break; - } - } - } - } - } finally { - if (delta != 0) - counter.add(delta); - } - if (npe) - throw new NullPointerException(); + static final void setTabAt(Node[] tab, int i, Node v) { + U.putOrderedObject(tab, ((long)i << ASHIFT) + ABASE, v); } - /* ---------------- Table Initialization and Resizing -------------- */ + /* ---------------- Fields -------------- */ /** - * Returns a power of two table size for the given desired capacity. - * See Hackers Delight, sec 3.2 + * The array of bins. Lazily initialized upon first insertion. + * Size is always a power of two. Accessed directly by iterators. */ - 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; - } + transient volatile Node[] table; /** - * Initializes table, using the size recorded in sizeCtl. + * The next table to use; non-null only while resizing. */ - 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 (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { - try { - if ((tab = table) == null) { - int n = (sc > 0) ? sc : DEFAULT_CAPACITY; - tab = table = new Node[n]; - sc = n - (n >>> 2); - } - } finally { - sizeCtl = sc; - } - break; - } - } - return tab; - } - - /** - * If table is too small and not already resizing, creates next - * table and transfers bins. Rechecks occupancy after a transfer - * to see if another resize is already needed because resizings - * are lagging additions. - */ - private final void checkForResize() { - Node[] tab; int n, sc; - while ((tab = table) != null && - (n = tab.length) < MAXIMUM_CAPACITY && - (sc = sizeCtl) >= 0 && counter.sum() >= (long)sc && - UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { - try { - if (tab == table) { - table = rebuild(tab); - sc = (n << 1) - (n >>> 1); - } - } finally { - sizeCtl = sc; - } - } - } + private transient volatile Node[] nextTable; /** - * Tries to presize table to accommodate the given number of elements. - * - * @param size number of elements (doesn't need to be perfectly accurate) + * Base counter value, used mainly when there is no contention, + * but also as a fallback during table initialization + * races. Updated via CAS. */ - 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 (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { - try { - if (table == tab) { - table = new Node[n]; - sc = n - (n >>> 2); - } - } finally { - sizeCtl = sc; - } - } - } - else if (c <= sc || n >= MAXIMUM_CAPACITY) - break; - else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { - try { - if (table == tab) { - table = rebuild(tab); - sc = (n << 1) - (n >>> 1); - } - } finally { - sizeCtl = sc; - } - } - } - } + private transient volatile long baseCount; - /* - * Moves and/or copies the nodes in each bin to new table. See - * above for explanation. - * - * @return the new table + /** + * 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 static final Node[] rebuild(Node[] tab) { - int n = tab.length; - Node[] nextTab = new Node[n << 1]; - Node fwd = new Node(MOVED, nextTab, null, null); - int[] buffer = null; // holds bins to revisit; null until needed - Node rev = null; // reverse forwarder; null until needed - int nbuffered = 0; // the number of bins in buffer list - int bufferIndex = 0; // buffer index of current buffered bin - int bin = n - 1; // current non-buffered bin or -1 if none - - for (int i = bin;;) { // start upwards sweep - int fh; Node f; - if ((f = tabAt(tab, i)) == null) { - if (bin >= 0) { // no lock needed (or available) - if (!casTabAt(tab, i, f, fwd)) - continue; - } - else { // transiently use a locked forwarding node - Node g = new Node(MOVED|LOCKED, nextTab, null, null); - if (!casTabAt(tab, i, f, g)) - continue; - setTabAt(nextTab, i, null); - setTabAt(nextTab, i + n, null); - setTabAt(tab, i, fwd); - if (!g.casHash(MOVED|LOCKED, MOVED)) { - g.hash = MOVED; - synchronized (g) { g.notifyAll(); } - } - } - } - else if ((fh = f.hash) == MOVED) { - Object fk = f.key; - if (fk instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean validated = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - validated = true; - splitTreeBin(nextTab, i, t); - setTabAt(tab, i, fwd); - } - } finally { - t.release(0); - } - if (!validated) - continue; - } - } - else if ((fh & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) { - boolean validated = false; - try { // split to lo and hi lists; copying as needed - if (tabAt(tab, i) == f) { - validated = true; - splitBin(nextTab, i, f); - setTabAt(tab, i, fwd); - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - if (!validated) - continue; - } - else { - if (buffer == null) // initialize buffer for revisits - buffer = new int[TRANSFER_BUFFER_SIZE]; - if (bin < 0 && bufferIndex > 0) { - int j = buffer[--bufferIndex]; - buffer[bufferIndex] = i; - i = j; // swap with another bin - continue; - } - if (bin < 0 || nbuffered >= TRANSFER_BUFFER_SIZE) { - f.tryAwaitLock(tab, i); - continue; // no other options -- block - } - if (rev == null) // initialize reverse-forwarder - rev = new Node(MOVED, tab, null, null); - if (tabAt(tab, i) != f || (f.hash & LOCKED) == 0) - continue; // recheck before adding to list - buffer[nbuffered++] = i; - setTabAt(nextTab, i, rev); // install place-holders - setTabAt(nextTab, i + n, rev); - } - - if (bin > 0) - i = --bin; - else if (buffer != null && nbuffered > 0) { - bin = -1; - i = buffer[bufferIndex = --nbuffered]; - } - else - return nextTab; - } - } + private transient volatile int sizeCtl; /** - * Splits a normal bin with list headed by e into lo and hi parts; - * installs in given table. + * The next table index (plus one) to split while resizing. */ - private static void splitBin(Node[] nextTab, int i, Node e) { - int bit = nextTab.length >>> 1; // bit to split on - int runBit = e.hash & bit; - Node lastRun = e, lo = null, hi = null; - for (Node p = e.next; p != null; p = p.next) { - int b = p.hash & bit; - if (b != runBit) { - runBit = b; - lastRun = p; - } - } - if (runBit == 0) - lo = lastRun; - else - hi = lastRun; - for (Node p = e; p != lastRun; p = p.next) { - int ph = p.hash & HASH_BITS; - Object pk = p.key, pv = p.val; - if ((ph & bit) == 0) - lo = new Node(ph, pk, pv, lo); - else - hi = new Node(ph, pk, pv, hi); - } - setTabAt(nextTab, i, lo); - setTabAt(nextTab, i + bit, hi); - } + private transient volatile int transferIndex; /** - * Splits a tree bin into lo and hi parts; installs in given table. + * The least available table index to split while resizing. */ - private static void splitTreeBin(Node[] nextTab, int i, TreeBin t) { - int bit = nextTab.length >>> 1; - TreeBin lt = new TreeBin(); - TreeBin ht = new TreeBin(); - int lc = 0, hc = 0; - for (Node e = t.first; e != null; e = e.next) { - int h = e.hash & HASH_BITS; - Object k = e.key, v = e.val; - if ((h & bit) == 0) { - ++lc; - lt.putTreeNode(h, k, v); - } - else { - ++hc; - ht.putTreeNode(h, k, v); - } - } - Node ln, hn; // throw away trees if too small - if (lc <= (TREE_THRESHOLD >>> 1)) { - ln = null; - for (Node p = lt.first; p != null; p = p.next) - ln = new Node(p.hash, p.key, p.val, ln); - } - else - ln = new Node(MOVED, lt, null, null); - setTabAt(nextTab, i, ln); - if (hc <= (TREE_THRESHOLD >>> 1)) { - hn = null; - for (Node p = ht.first; p != null; p = p.next) - hn = new Node(p.hash, p.key, p.val, hn); - } - else - hn = new Node(MOVED, ht, null, null); - setTabAt(nextTab, i + bit, hn); - } + private transient volatile int transferOrigin; /** - * Implementation for clear. Steps through each bin, removing all - * nodes. + * Spinlock (locked via CAS) used when resizing and/or creating CounterCells. */ - private final void internalClear() { - long delta = 0L; // negative number of deletions - int i = 0; - Node[] tab = table; - while (tab != null && i < tab.length) { - int fh; Object fk; - Node f = tabAt(tab, i); - if (f == null) - ++i; - else if ((fh = f.hash) == MOVED) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - for (Node p = t.first; p != null; p = p.next) { - p.val = null; - --delta; - } - t.first = null; - t.root = null; - ++i; - } - } finally { - t.release(0); - } - } - else - tab = (Node[])fk; - } - else if ((fh & LOCKED) != 0) { - counter.add(delta); // opportunistically update count - delta = 0L; - f.tryAwaitLock(tab, i); - } - else if (f.casHash(fh, fh | LOCKED)) { - try { - if (tabAt(tab, i) == f) { - for (Node e = f; e != null; e = e.next) { - e.val = null; - --delta; - } - setTabAt(tab, i, null); - ++i; - } - } finally { - if (!f.casHash(fh | LOCKED, fh)) { - f.hash = fh; - synchronized (f) { f.notifyAll(); }; - } - } - } - } - if (delta != 0) - counter.add(delta); - } - - /* ----------------Table Traversal -------------- */ + private transient volatile int cellsBusy; /** - * Encapsulates traversal for methods such as containsValue; also - * serves as a base class for other iterators. - * - * 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. - * - * 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 ForkJoinTask to streamline parallel - * iteration in bulk operations (see BulkTask). This adds only an - * int of space overhead, which is close enough to negligible in - * cases where it is not needed to not worry about it. - */ - static class Traverser extends ForkJoinTask { - final ConcurrentHashMapV8 map; - Node next; // the next entry to use - Node last; // the last entry used - Object nextKey; // cached key field of next - Object nextVal; // cached val field of next - Node[] tab; // current table; updated if resized - int index; // index of bin to use next - int baseIndex; // current index of initial table - int baseLimit; // index bound for initial table - final int baseSize; // initial table size - - /** Creates iterator for all entries in the table. */ - Traverser(ConcurrentHashMapV8 map) { - this.tab = (this.map = map).table; - baseLimit = baseSize = (tab == null) ? 0 : tab.length; - } - - /** Creates iterator for split() methods */ - Traverser(Traverser it, boolean split) { - this.map = it.map; - this.tab = it.tab; - this.baseSize = it.baseSize; - int lo = it.baseIndex; - int hi = this.baseLimit = it.baseLimit; - int i; - if (split) // adjust parent - i = it.baseLimit = (lo + hi + 1) >>> 1; - else // clone parent - i = lo; - this.index = this.baseIndex = i; - } - - /** - * Advances next; returns nextVal or null if terminated. - * See above for explanation. - */ - final Object advance() { - Node e = last = next; - Object ev = null; - outer: do { - if (e != null) // advance past used/skipped node - e = e.next; - while (e == null) { // get to next non-null bin - Node[] t; int b, i, n; Object ek; // checks must use locals - if ((b = baseIndex) >= baseLimit || (i = index) < 0 || - (t = tab) == null || i >= (n = t.length)) - break outer; - else if ((e = tabAt(t, i)) != null && e.hash == MOVED) { - if ((ek = e.key) instanceof TreeBin) - e = ((TreeBin)ek).first; - else { - tab = (Node[])ek; - continue; // restarts due to null val - } - } // visit upper slots if present - index = (i += baseSize) < n ? i : (baseIndex = b + 1); - } - nextKey = e.key; - } while ((ev = e.val) == null); // skip deleted or special nodes - next = e; - return nextVal = ev; - } - - public final void remove() { - if (nextVal == null) - advance(); - Node e = last; - if (e == null) - throw new IllegalStateException(); - last = null; - map.remove(e.key); - } + * Table of counter cells. When non-null, size is a power of 2. + */ + private transient volatile CounterCell[] counterCells; - public final boolean hasNext() { - return nextVal != null || advance() != null; - } + // views + private transient KeySetView keySet; + private transient ValuesView values; + private transient EntrySetView entrySet; - public final boolean hasMoreElements() { return hasNext(); } - public final void setRawResult(Object x) { } - public R getRawResult() { return null; } - public boolean exec() { return true; } - } /* ---------------- Public operations -------------- */ @@ -2352,7 +802,6 @@ public class ConcurrentHashMapV8 * Creates a new, empty map with the default initial table size (16). */ public ConcurrentHashMapV8() { - this.counter = new LongAdder(); } /** @@ -2371,7 +820,6 @@ public class ConcurrentHashMapV8 int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1)); - this.counter = new LongAdder(); this.sizeCtl = cap; } @@ -2381,9 +829,8 @@ public class ConcurrentHashMapV8 * @param m the map */ public ConcurrentHashMapV8(Map m) { - this.counter = new LongAdder(); this.sizeCtl = DEFAULT_CAPACITY; - internalPutAll(m); + putAll(m); } /** @@ -2424,7 +871,7 @@ public class ConcurrentHashMapV8 * nonpositive */ public ConcurrentHashMapV8(int initialCapacity, - float loadFactor, int concurrencyLevel) { + float loadFactor, int concurrencyLevel) { if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0) throw new IllegalArgumentException(); if (initialCapacity < concurrencyLevel) // Use at least as many bins @@ -2432,39 +879,26 @@ public class ConcurrentHashMapV8 long size = (long)(1.0 + (long)initialCapacity / loadFactor); int cap = (size >= (long)MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : tableSizeFor((int)size); - this.counter = new LongAdder(); this.sizeCtl = cap; } - /** - * {@inheritDoc} - */ - public boolean isEmpty() { - return counter.sum() <= 0L; // ignore transient negative values - } + // Original (since JDK1.2) Map methods /** * {@inheritDoc} */ public int size() { - long n = counter.sum(); + 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 ConcurrentHashMap may - * contain more mappings than can be represented as an int. The - * value returned is a snapshot; the actual count may differ if - * there are ongoing concurrent insertions of removals. - * - * @return the number of mappings + * {@inheritDoc} */ - public long mappingCount() { - long n = counter.sum(); - return (n < 0L) ? 0L : n; + public boolean isEmpty() { + return sumCount() <= 0L; // ignore transient negative values } /** @@ -2478,26 +912,37 @@ public class ConcurrentHashMapV8 * * @throws NullPointerException if the specified key is null */ - @SuppressWarnings("unchecked") - public V get(Object key) { - if (key == null) - throw new NullPointerException(); - return (V)internalGet(key); + public V get(Object key) { + Node[] tab; Node e, p; int n, eh; K ek; + int h = spread(key.hashCode()); + if ((tab = table) != null && (n = tab.length) > 0 && + (e = tabAt(tab, (n - 1) & h)) != null) { + if ((eh = e.hash) == h) { + if ((ek = e.key) == key || (ek != null && key.equals(ek))) + return e.val; + } + else if (eh < 0) + return (p = e.find(h, key)) != null ? p.val : null; + while ((e = e.next) != null) { + if (e.hash == h && + ((ek = e.key) == key || (ek != null && key.equals(ek)))) + return e.val; + } + } + return null; } /** * Tests if the specified object is a key in this table. * - * @param key possible key + * @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) { - if (key == null) - throw new NullPointerException(); - return internalGet(key) != null; + return get(key) != null; } /** @@ -2513,39 +958,23 @@ public class ConcurrentHashMapV8 public boolean containsValue(Object value) { if (value == null) throw new NullPointerException(); - Object v; - Traverser it = new Traverser(this); - while ((v = it.advance()) != null) { - if (v == value || value.equals(v)) - return true; + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V v; + if ((v = p.val) == value || (v != null && 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 - */ - 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 + *

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 @@ -2554,25 +983,73 @@ public class ConcurrentHashMapV8 * {@code null} if there was no mapping for {@code key} * @throws NullPointerException if the specified key or value is null */ - @SuppressWarnings("unchecked") - public V put(K key, V value) { - if (key == null || value == null) - throw new NullPointerException(); - return (V)internalPut(key, value); + public V put(K key, V value) { + return putVal(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 - */ - @SuppressWarnings("unchecked") - public V putIfAbsent(K key, V value) { - if (key == null || value == null) - throw new NullPointerException(); - return (V)internalPutIfAbsent(key, value); + /** Implementation for put and putIfAbsent */ + final V putVal(K key, V value, boolean onlyIfAbsent) { + if (key == null || value == null) throw new NullPointerException(); + int hash = spread(key.hashCode()); + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) { + if (casTabAt(tab, i, null, + new Node(hash, key, value, null))) + break; // no lock when adding to empty bin + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + V oldVal = null; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + oldVal = e.val; + if (!onlyIfAbsent) + e.val = value; + break; + } + Node pred = e; + if ((e = e.next) == null) { + pred.next = new Node(hash, key, + value, null); + break; + } + } + } + else if (f instanceof TreeBin) { + Node p; + binCount = 2; + if ((p = ((TreeBin)f).putTreeVal(hash, key, + value)) != null) { + oldVal = p.val; + if (!onlyIfAbsent) + p.val = value; + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + if (oldVal != null) + return oldVal; + break; + } + } + } + addCount(1L, binCount); + return null; } /** @@ -2583,174 +1060,9 @@ public class ConcurrentHashMapV8 * @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 - */ - @SuppressWarnings("unchecked") - public V computeIfAbsent(K key, Fun mappingFunction) { - if (key == null || mappingFunction == null) - throw new NullPointerException(); - return (V)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) { - if (key == null || remappingFunction == null) - throw new NullPointerException(); - return (V)internalCompute(key, true, remappingFunction); - } - - /** - * Computes a new mapping value given a key and - * its current mapped value (or {@code null} if there is no current - * mapping). This is equivalent to - * 
 {@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 - */ - // @SuppressWarnings("unchecked") - public V compute(K key, BiFun remappingFunction) { - if (key == null || remappingFunction == null) - throw new NullPointerException(); - return (V)internalCompute(key, false, remappingFunction); - } - - /** - * If the specified key is not already associated - * with a value, associate it with the given value. - * Otherwise, replace the value with the results of - * the given remapping function. This is equivalent to: - * 
 {@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. - */ - // @SuppressWarnings("unchecked") - public V merge(K key, V value, BiFun remappingFunction) { - if (key == null || value == null || remappingFunction == null) - throw new NullPointerException(); - return (V)internalMerge(key, value, remappingFunction); + tryPresize(m.size()); + for (Map.Entry e : m.entrySet()) + putVal(e.getKey(), e.getValue(), false); } /** @@ -2762,62 +1074,125 @@ public class ConcurrentHashMapV8 * {@code null} if there was no mapping for {@code key} * @throws NullPointerException if the specified key is null */ - @SuppressWarnings("unchecked") - public V remove(Object key) { - if (key == null) - throw new NullPointerException(); - return (V)internalReplace(key, null, null); + public V remove(Object key) { + return replaceNode(key, null, null); } /** - * {@inheritDoc} - * - * @throws NullPointerException if the specified key is null - */ - public boolean remove(Object key, Object value) { - if (key == null) - throw new NullPointerException(); - if (value == null) - return false; - return 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 + * 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") - public V replace(K key, V value) { - if (key == null || value == null) - throw new NullPointerException(); - return (V)internalReplace(key, value, null); + final V replaceNode(Object key, V value, Object cv) { + int hash = spread(key.hashCode()); + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0 || + (f = tabAt(tab, i = (n - 1) & hash)) == null) + break; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + V oldVal = null; + boolean validated = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + validated = true; + for (Node e = f, pred = null;;) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + V ev = e.val; + if (cv == null || cv == ev || + (ev != null && cv.equals(ev))) { + oldVal = ev; + if (value != null) + e.val = value; + else if (pred != null) + pred.next = e.next; + else + setTabAt(tab, i, e.next); + } + break; + } + pred = e; + if ((e = e.next) == null) + break; + } + } + else if (f instanceof TreeBin) { + validated = true; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(hash, key, null)) != null) { + V pv = p.val; + if (cv == null || cv == pv || + (pv != null && cv.equals(pv))) { + oldVal = pv; + if (value != null) + p.val = value; + else if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + if (validated) { + if (oldVal != null) { + if (value == null) + addCount(-1L, -1); + return oldVal; + } + break; + } + } + } + return null; } /** * Removes all of the mappings from this map. */ public void clear() { - internalClear(); + long delta = 0L; // negative number of deletions + int i = 0; + Node[] tab = table; + while (tab != null && i < tab.length) { + int fh; + Node f = tabAt(tab, i); + if (f == null) + ++i; + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + i = 0; // restart + } + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node p = (fh >= 0 ? f : + (f instanceof TreeBin) ? + ((TreeBin)f).first : null); + while (p != null) { + --delta; + p = p.next; + } + setTabAt(tab, i++, null); + } + } + } + } + if (delta != 0L) + addCount(delta, -1); } /** * Returns a {@link Set} view of the keys contained in this map. * The set is backed by the map, so changes to the map are - * reflected in the set, and vice-versa. The set supports element + * reflected in the set, and vice-versa. The set supports element * removal, which removes the corresponding mapping from this map, * via the {@code Iterator.remove}, {@code Set.remove}, * {@code removeAll}, {@code retainAll}, and {@code clear} @@ -2829,10 +1204,12 @@ public class ConcurrentHashMapV8 * and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) * reflect any modifications subsequent to construction. + * + * @return the set view */ - public Set keySet() { - KeySet ks = keySet; - return (ks != null) ? ks : (keySet = new KeySet(this)); + public KeySetView keySet() { + KeySetView ks; + return (ks = keySet) != null ? ks : (keySet = new KeySetView(this, null)); } /** @@ -2850,10 +1227,12 @@ public class ConcurrentHashMapV8 * and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) * reflect any modifications subsequent to construction. + * + * @return the collection view */ public Collection values() { - Values vs = values; - return (vs != null) ? vs : (values = new Values(this)); + ValuesView vs; + return (vs = values) != null ? vs : (values = new ValuesView(this)); } /** @@ -2863,65 +1242,19 @@ public class ConcurrentHashMapV8 * 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. + * 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() { - EntrySet es = entrySet; - return (es != null) ? es : (entrySet = new EntrySet(this)); - } - - /** - * Returns an enumeration of the keys in this table. * - * @return an enumeration of the keys in this table - * @see #keySet() + * @return the set view */ - 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 partionable iterator of the keys in this map. - * - * @return a partionable iterator of the keys in this map - */ - public Spliterator keySpliterator() { - return new KeyIterator(this); - } - - /** - * Returns a partionable iterator of the values in this map. - * - * @return a partionable iterator of the values in this map - */ - public Spliterator valueSpliterator() { - return new ValueIterator(this); - } - - /** - * Returns a partionable iterator of the entries in this map. - * - * @return a partionable iterator of the entries in this map - */ - public Spliterator> entrySpliterator() { - return new EntryIterator(this); + public Set> entrySet() { + EntrySetView es; + return (es = entrySet) != null ? es : (entrySet = new EntrySetView(this)); } /** @@ -2933,10 +1266,11 @@ public class ConcurrentHashMapV8 */ public int hashCode() { int h = 0; - Traverser it = new Traverser(this); - Object v; - while ((v = it.advance()) != null) { - h += it.nextKey.hashCode() ^ v.hashCode(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + h += p.key.hashCode() ^ p.val.hashCode(); } return h; } @@ -2953,17 +1287,20 @@ public class ConcurrentHashMapV8 * @return a string representation of this map */ public String toString() { - Traverser it = new Traverser(this); + Node[] t; + int f = (t = table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); StringBuilder sb = new StringBuilder(); sb.append('{'); - Object v; - if ((v = it.advance()) != null) { + Node p; + if ((p = it.advance()) != null) { for (;;) { - Object k = it.nextKey; + K k = p.key; + V v = p.val; sb.append(k == this ? "(this Map)" : k); sb.append('='); sb.append(v == this ? "(this Map)" : v); - if ((v = it.advance()) == null) + if ((p = it.advance()) == null) break; sb.append(',').append(' '); } @@ -2986,10 +1323,12 @@ public class ConcurrentHashMapV8 if (!(o instanceof Map)) return false; Map m = (Map) o; - Traverser it = new Traverser(this); - Object val; - while ((val = it.advance()) != null) { - Object v = m.get(it.nextKey); + Node[] t; + int f = (t = table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); + for (Node p; (p = it.advance()) != null; ) { + V val = p.val; + Object v = m.get(p.key); if (v == null || (v != val && !v.equals(val))) return false; } @@ -2997,7 +1336,7 @@ public class ConcurrentHashMapV8 Object mk, mv, v; if ((mk = e.getKey()) == null || (mv = e.getValue()) == null || - (v = internalGet(mk)) == null || + (v = get(mk)) == null || (mv != v && !mv.equals(v))) return false; } @@ -3005,1933 +1344,3258 @@ public class ConcurrentHashMapV8 return true; } - /* ----------------Iterators -------------- */ + /** + * Stripped-down version of helper class used in previous version, + * declared for the sake of serialization compatibility + */ + static class Segment extends ReentrantLock implements Serializable { + private static final long serialVersionUID = 2249069246763182397L; + final float loadFactor; + Segment(float lf) { this.loadFactor = lf; } + } - static final class KeyIterator extends Traverser - implements Spliterator, Enumeration { - KeyIterator(ConcurrentHashMapV8 map) { super(map); } - KeyIterator(Traverser it, boolean split) { - super(it, split); - } - public KeyIterator split() { - if (last != null || (next != null && nextVal == null)) - throw new IllegalStateException(); - return new KeyIterator(this, true); - } - @SuppressWarnings("unchecked") - public final K next() { - if (nextVal == null && advance() == null) - throw new NoSuchElementException(); - Object k = nextKey; - nextVal = null; - return (K) k; + /** + * 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. + */ + private void writeObject(java.io.ObjectOutputStream s) + throws java.io.IOException { + // For serialization compatibility + // Emulate segment calculation from previous version of this class + int sshift = 0; + int ssize = 1; + while (ssize < DEFAULT_CONCURRENCY_LEVEL) { + ++sshift; + ssize <<= 1; + } + int segmentShift = 32 - sshift; + int segmentMask = ssize - 1; + @SuppressWarnings("unchecked") Segment[] segments = (Segment[]) + new Segment[DEFAULT_CONCURRENCY_LEVEL]; + for (int i = 0; i < segments.length; ++i) + segments[i] = new Segment(LOAD_FACTOR); + s.putFields().put("segments", segments); + s.putFields().put("segmentShift", segmentShift); + s.putFields().put("segmentMask", segmentMask); + s.writeFields(); + + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + s.writeObject(p.key); + s.writeObject(p.val); + } } - - public final K nextElement() { return next(); } + s.writeObject(null); + s.writeObject(null); + segments = null; // throw away } - static final class ValueIterator extends Traverser - implements Spliterator, Enumeration { - ValueIterator(ConcurrentHashMapV8 map) { super(map); } - ValueIterator(Traverser it, boolean split) { - super(it, split); - } - public ValueIterator split() { - if (last != null || (next != null && nextVal == null)) - throw new IllegalStateException(); - return new ValueIterator(this, true); + /** + * Reconstitutes the instance from a stream (that is, deserializes it). + * @param s the stream + */ + private void readObject(java.io.ObjectInputStream s) + throws java.io.IOException, ClassNotFoundException { + /* + * To improve performance in typical cases, we create nodes + * while reading, then place in table once size is known. + * However, we must also validate uniqueness and deal with + * overpopulated bins while doing so, which requires + * specialized versions of putVal mechanics. + */ + sizeCtl = -1; // force exclusion for table construction + s.defaultReadObject(); + long size = 0L; + Node p = null; + for (;;) { + @SuppressWarnings("unchecked") K k = (K) s.readObject(); + @SuppressWarnings("unchecked") V v = (V) s.readObject(); + if (k != null && v != null) { + p = new Node(spread(k.hashCode()), k, v, p); + ++size; + } + else + break; } - - @SuppressWarnings("unchecked") - public final V next() { - Object v; - if ((v = nextVal) == null && (v = advance()) == null) - throw new NoSuchElementException(); - nextVal = null; - return (V) v; + if (size == 0L) + sizeCtl = 0; + else { + int n; + if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) + n = MAXIMUM_CAPACITY; + else { + int sz = (int)size; + n = tableSizeFor(sz + (sz >>> 1) + 1); + } + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] tab = (Node[])new Node[n]; + int mask = n - 1; + long added = 0L; + while (p != null) { + boolean insertAtFront; + Node next = p.next, first; + int h = p.hash, j = h & mask; + if ((first = tabAt(tab, j)) == null) + insertAtFront = true; + else { + K k = p.key; + if (first.hash < 0) { + TreeBin t = (TreeBin)first; + if (t.putTreeVal(h, k, p.val) == null) + ++added; + insertAtFront = false; + } + else { + int binCount = 0; + insertAtFront = true; + Node q; K qk; + for (q = first; q != null; q = q.next) { + if (q.hash == h && + ((qk = q.key) == k || + (qk != null && k.equals(qk)))) { + insertAtFront = false; + break; + } + ++binCount; + } + if (insertAtFront && binCount >= TREEIFY_THRESHOLD) { + insertAtFront = false; + ++added; + p.next = first; + TreeNode hd = null, tl = null; + for (q = p; q != null; q = q.next) { + TreeNode t = new TreeNode + (q.hash, q.key, q.val, null, null); + if ((t.prev = tl) == null) + hd = t; + else + tl.next = t; + tl = t; + } + setTabAt(tab, j, new TreeBin(hd)); + } + } + } + if (insertAtFront) { + ++added; + p.next = first; + setTabAt(tab, j, p); + } + p = next; + } + table = tab; + sizeCtl = n - (n >>> 2); + baseCount = added; } - - public final V nextElement() { return next(); } } - static final class EntryIterator extends Traverser - implements Spliterator> { - EntryIterator(ConcurrentHashMapV8 map) { super(map); } - EntryIterator(Traverser it, boolean split) { - super(it, split); - } - public EntryIterator split() { - if (last != null || (next != null && nextVal == null)) - throw new IllegalStateException(); - return new EntryIterator(this, true); - } + // ConcurrentMap methods - @SuppressWarnings("unchecked") - public final Map.Entry next() { - Object v; - if ((v = nextVal) == null && (v = advance()) == null) - throw new NoSuchElementException(); - Object k = nextKey; - nextVal = null; - return new MapEntry((K)k, (V)v, map); - } + /** + * {@inheritDoc} + * + * @return the previous value associated with the specified key, + * or {@code null} if there was no mapping for the key + * @throws NullPointerException if the specified key or value is null + */ + public V putIfAbsent(K key, V value) { + return putVal(key, value, true); } /** - * Exported Entry for iterators + * {@inheritDoc} + * + * @throws NullPointerException if the specified key is null */ - 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; - } + public boolean remove(Object key, Object value) { + if (key == null) + throw new NullPointerException(); + return value != null && replaceNode(key, null, value) != null; } - /* ----------------Views -------------- */ + /** + * {@inheritDoc} + * + * @throws NullPointerException if any of the arguments are null + */ + public boolean replace(K key, V oldValue, V newValue) { + if (key == null || oldValue == null || newValue == null) + throw new NullPointerException(); + return replaceNode(key, newValue, oldValue) != null; + } /** - * Base class for views. + * {@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 */ - static abstract class CHMView { - final ConcurrentHashMapV8 map; - CHMView(ConcurrentHashMapV8 map) { this.map = map; } - public final int size() { return map.size(); } - public final boolean isEmpty() { return map.isEmpty(); } - public final void clear() { map.clear(); } + public V replace(K key, V value) { + if (key == null || value == null) + throw new NullPointerException(); + return replaceNode(key, value, null); + } - // implementations below rely on concrete classes supplying these - abstract public Iterator iterator(); - abstract public boolean contains(Object o); - abstract public boolean remove(Object o); + // Overrides of JDK8+ Map extension method defaults - private static final String oomeMsg = "Required array size too large"; + /** + * Returns the value to which the specified key is mapped, or the + * given default value if this map contains no mapping for the + * key. + * + * @param key the key whose associated value is to be returned + * @param defaultValue the value to return if this map contains + * no mapping for the given key + * @return the mapping for the key, if present; else the default value + * @throws NullPointerException if the specified key is null + */ + public V getOrDefault(Object key, V defaultValue) { + V v; + return (v = get(key)) == null ? defaultValue : v; + } + + public void forEach(BiAction action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(p.key, p.val); + } + } + } - 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); + public void replaceAll(BiFun function) { + if (function == null) throw new NullPointerException(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V oldValue = p.val; + for (K key = p.key;;) { + V newValue = function.apply(key, oldValue); + if (newValue == null) + throw new NullPointerException(); + if (replaceNode(key, newValue, oldValue) != null || + (oldValue = get(key)) == null) + break; } - 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); + /** + * If the specified key is not already associated with a value, + * attempts to compute its value using the given mapping function + * and enters it into this map unless {@code null}. The entire + * method invocation is performed atomically, so the function is + * applied at most once per key. Some attempted update operations + * on this map by other threads may be blocked while computation + * is in progress, so the computation should be short and simple, + * and must not attempt to update any other mappings of this map. + * + * @param key key with which the specified value is to be associated + * @param mappingFunction the function to compute a value + * @return the current (existing or computed) value associated with + * the specified key, or null if the computed value is null + * @throws NullPointerException if the specified key or mappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the mappingFunction does so, + * in which case the mapping is left unestablished + */ + public V computeIfAbsent(K key, Fun mappingFunction) { + if (key == null || mappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = mappingFunction.apply(key)) != null) + node = new Node(h, key, val, null); + } finally { + setTabAt(tab, i, node); + } + } } - r[i++] = (T)it.next(); + if (binCount != 0) + break; } - if (a == r && i < n) { - r[i] = null; // null-terminate - return r; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + boolean added = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; V ev; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = e.val; + break; + } + Node pred = e; + if ((e = e.next) == null) { + if ((val = mappingFunction.apply(key)) != null) { + added = true; + pred.next = new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) + val = p.val; + else if ((val = mappingFunction.apply(key)) != null) { + added = true; + t.putTreeVal(h, key, val); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + if (!added) + return val; + break; + } } - 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; } + if (val != null) + addCount(1L, binCount); + return val; + } - 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(' '); + /** + * If the value for the specified key is present, attempts to + * compute a new mapping given the key and its current mapped + * value. The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this map. + * + * @param key key with which a value may be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V computeIfPresent(K key, BiFun remappingFunction) { + if (key == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) + break; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(key, e.val); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) + break; + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) { + val = remappingFunction.apply(key, p.val); + if (val != null) + p.val = val; + else { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } } + if (binCount != 0) + break; } - return sb.append(']').toString(); } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } - 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; + /** + * Attempts to compute a mapping for the specified key and its + * current mapped value (or {@code null} if there is no current + * mapping). The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V compute(K key, + BiFun remappingFunction) { + if (key == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = remappingFunction.apply(key, null)) != null) { + delta = 1; + node = new Node(h, key, val, null); + } + } finally { + setTabAt(tab, i, node); + } + } } + if (binCount != 0) + break; } - 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; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(key, e.val); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) { + val = remappingFunction.apply(key, null); + if (val != null) { + delta = 1; + pred.next = + new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 1; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null) + p = r.findTreeNode(h, key, null); + else + p = null; + V pv = (p == null) ? null : p.val; + val = remappingFunction.apply(key, pv); + if (val != null) { + if (p != null) + p.val = val; + else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + break; } } - return modified; } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } - public final boolean retainAll(Collection c) { - boolean modified = false; - for (Iterator it = iterator(); it.hasNext();) { - if (!c.contains(it.next())) { - it.remove(); - modified = true; + /** + * If the specified key is not already associated with a + * (non-null) value, associates it with the given value. + * Otherwise, replaces the value with the results of the given + * remapping function, or removes if {@code null}. The entire + * method invocation is performed atomically. Some attempted + * update operations on this map by other threads may be blocked + * while computation is in progress, so the computation should be + * short and simple, and must not attempt to update any other + * mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param value the value to use if absent + * @param remappingFunction the function to recompute a value if present + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or the + * remappingFunction is null + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V merge(K key, V value, BiFun remappingFunction) { + if (key == null || value == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + if (casTabAt(tab, i, null, new Node(h, key, value, null))) { + delta = 1; + val = value; + break; + } + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(e.val, value); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) { + delta = 1; + val = value; + pred.next = + new Node(h, key, val, null); + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r = t.root; + TreeNode p = (r == null) ? null : + r.findTreeNode(h, key, null); + val = (p == null) ? value : + remappingFunction.apply(p.val, value); + if (val != null) { + if (p != null) + p.val = val; + else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + break; } } - return modified; } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } + + // Hashtable legacy methods + + /** + * Legacy method testing if some key maps into the specified value + * in this table. This method is identical in functionality to + * {@link #containsValue(Object)}, and exists solely to ensure + * full compatibility with class {@link java.util.Hashtable}, + * which supported this method prior to introduction of the + * Java Collections framework. + * + * @param value a value to search for + * @return {@code true} if and only if some key maps to the + * {@code value} argument in this table as + * determined by the {@code equals} method; + * {@code false} otherwise + * @throws NullPointerException if the specified value is null + */ + @Deprecated public boolean contains(Object value) { + return containsValue(value); + } + /** + * Returns an enumeration of the keys in this table. + * + * @return an enumeration of the keys in this table + * @see #keySet() + */ + public Enumeration keys() { + Node[] t; + int f = (t = table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, this); } - static final class KeySet extends CHMView implements Set { - KeySet(ConcurrentHashMapV8 map) { - super(map); - } - public final boolean contains(Object o) { return map.containsKey(o); } - public final boolean remove(Object o) { return map.remove(o) != null; } - public final Iterator iterator() { - return new KeyIterator(map); - } - public final boolean add(K e) { - throw new UnsupportedOperationException(); - } - public final boolean addAll(Collection c) { - throw new UnsupportedOperationException(); - } - public boolean equals(Object o) { - Set c; - return ((o instanceof Set) && - ((c = (Set)o) == this || - (containsAll(c) && c.containsAll(this)))); - } + /** + * Returns an enumeration of the values in this table. + * + * @return an enumeration of the values in this table + * @see #values() + */ + public Enumeration elements() { + Node[] t; + int f = (t = table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, this); } + // ConcurrentHashMapV8-only methods - static final class Values extends CHMView - implements Collection { - Values(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; - } - 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(); - } + /** + * 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 + * @since 1.8 + */ + public long mappingCount() { + long n = sumCount(); + return (n < 0L) ? 0L : n; // ignore transient negative values + } + /** + * Creates a new {@link Set} backed by a ConcurrentHashMapV8 + * from the given type to {@code Boolean.TRUE}. + * + * @return the new set + * @since 1.8 + */ + public static KeySetView newKeySet() { + return new KeySetView + (new ConcurrentHashMapV8(), Boolean.TRUE); } - static final class EntrySet extends CHMView - implements Set> { - EntrySet(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)); - } - public final Iterator> iterator() { - return new EntryIterator(map); - } - public final boolean add(Entry e) { - throw new UnsupportedOperationException(); + /** + * 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 + * @since 1.8 + */ + public static KeySetView newKeySet(int initialCapacity) { + return new KeySetView + (new ConcurrentHashMapV8(initialCapacity), Boolean.TRUE); + } + + /** + * Returns a {@link Set} view of the keys in this map, using the + * given common mapped value for any additions (i.e., {@link + * Collection#add} and {@link Collection#addAll(Collection)}). + * This is of course only appropriate if it is acceptable to use + * the same value for all additions from this view. + * + * @param mappedValue the mapped value to use for any additions + * @return the set view + * @throws NullPointerException if the mappedValue is null + */ + public KeySetView keySet(V mappedValue) { + if (mappedValue == null) + throw new NullPointerException(); + return new KeySetView(this, mappedValue); + } + + /* ---------------- Special Nodes -------------- */ + + /** + * A node inserted at head of bins during transfer operations. + */ + static final class ForwardingNode extends Node { + final Node[] nextTable; + ForwardingNode(Node[] tab) { + super(MOVED, null, null, null); + this.nextTable = tab; + } + + Node find(int h, Object k) { + Node e; int n; + Node[] tab = nextTable; + if (k != null && tab != null && (n = tab.length) > 0 && + (e = tabAt(tab, (n - 1) & h)) != null) { + do { + int eh; K ek; + if ((eh = e.hash) == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + if (eh < 0) + return e.find(h, k); + } while ((e = e.next) != null); + } + return null; } - public final boolean addAll(Collection> c) { - throw new UnsupportedOperationException(); + } + + /** + * A place-holder node used in computeIfAbsent and compute + */ + static final class ReservationNode extends Node { + ReservationNode() { + super(RESERVED, null, null, null); } - public boolean equals(Object o) { - Set c; - return ((o instanceof Set) && - ((c = (Set)o) == this || - (containsAll(c) && c.containsAll(this)))); + + Node find(int h, Object k) { + return null; } } - /* ---------------- Serialization Support -------------- */ + /* ---------------- Table Initialization and Resizing -------------- */ /** - * Stripped-down version of helper class used in previous version, - * declared for the sake of serialization compatibility + * Initializes table, using the size recorded in sizeCtl. */ - static class Segment implements Serializable { - private static final long serialVersionUID = 2249069246763182397L; - final float loadFactor; - Segment(float lf) { this.loadFactor = lf; } + private final Node[] initTable() { + Node[] tab; int sc; + while ((tab = table) == null || tab.length == 0) { + if ((sc = sizeCtl) < 0) + Thread.yield(); // lost initialization race; just spin + else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { + try { + if ((tab = table) == null || tab.length == 0) { + int n = (sc > 0) ? sc : DEFAULT_CAPACITY; + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = (Node[])new Node[n]; + table = tab = nt; + sc = n - (n >>> 2); + } + } finally { + sizeCtl = sc; + } + break; + } + } + return tab; } /** - * 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); - Object v; - while ((v = it.advance()) != null) { - s.writeObject(it.nextKey); - s.writeObject(v); + * 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(); + } } - s.writeObject(null); - s.writeObject(null); - segments = null; // throw away } /** - * Reconstitutes the instance from a stream (that is, deserializes it). - * @param s the stream + * Helps transfer if a resize is in progress. */ - @SuppressWarnings("unchecked") - private void readObject(java.io.ObjectInputStream s) - throws java.io.IOException, ClassNotFoundException { - s.defaultReadObject(); - this.segments = null; // unneeded - // initialize transient final field - UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder()); + final Node[] helpTransfer(Node[] tab, Node f) { + Node[] nextTab; int sc; + if ((f instanceof ForwardingNode) && + (nextTab = ((ForwardingNode)f).nextTable) != null) { + if (nextTab == nextTable && tab == table && + transferIndex > transferOrigin && (sc = sizeCtl) < -1 && + U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) + transfer(tab, nextTab); + return nextTab; + } + return table; + } - // 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; + /** + * Tries to presize table to accommodate the given number of elements. + * + * @param size number of elements (doesn't need to be perfectly accurate) + */ + private final void tryPresize(int size) { + int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : + tableSizeFor(size + (size >>> 1) + 1); + int sc; + while ((sc = sizeCtl) >= 0) { + Node[] 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","unchecked"}) + Node[] nt = (Node[])new Node[n]; + table = nt; + sc = n - (n >>> 2); + } + } finally { + sizeCtl = sc; + } + } } - else + else if (c <= sc || n >= MAXIMUM_CAPACITY) break; + else if (tab == table && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) + transfer(tab, null); } - if (p != null) { - boolean init = false; - int n; - if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) - n = MAXIMUM_CAPACITY; - else { - int sz = (int)size; - n = tableSizeFor(sz + (sz >>> 1) + 1); - } - int sc = sizeCtl; - boolean collide = false; - if (n > sc && - UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) { - try { - if (table == null) { - init = true; - Node[] tab = new Node[n]; - int mask = n - 1; - while (p != null) { - int j = p.hash & mask; - Node next = p.next; - Node q = p.next = tabAt(tab, j); - setTabAt(tab, j, p); - if (!collide && q != null && q.hash == p.hash) - collide = true; - p = next; + } + + /** + * Moves and/or copies the nodes in each bin to new table. See + * above for explanation. + */ + 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","unchecked"}) + Node[] nt = (Node[])new Node[n << 1]; + nextTab = nt; + } catch (Throwable ex) { // try to cope with OOME + sizeCtl = Integer.MAX_VALUE; + return; + } + nextTable = nextTab; + transferOrigin = n; + transferIndex = n; + ForwardingNode rev = new ForwardingNode(tab); + 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; + ForwardingNode fwd = new ForwardingNode(nextTab); + boolean advance = true; + for (int i = 0, bound = 0;;) { + int nextIndex, nextBound, fh; Node f; + 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); } - table = tab; - counter.add(size); - sc = n - (n >>> 2); + return; } - } 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; + } + 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 ((fh = f.hash) == MOVED) + advance = true; // already processed + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node ln, hn; + if (fh >= 0) { + int runBit = fh & n; + Node lastRun = f; + 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) { + ln = lastRun; + hn = null; + } + else { + hn = lastRun; + ln = null; + } + for (Node p = f; p != lastRun; p = p.next) { + int ph = p.hash; K pk = p.key; V pv = p.val; + if ((ph & n) == 0) + ln = new Node(ph, pk, pv, ln); + else + hn = new Node(ph, pk, pv, hn); } } + else if (f instanceof TreeBin) { + TreeBin t = (TreeBin)f; + TreeNode lo = null, loTail = null; + TreeNode hi = null, hiTail = null; + int lc = 0, hc = 0; + for (Node e = t.first; e != null; e = e.next) { + int h = e.hash; + TreeNode p = new TreeNode + (h, e.key, e.val, null, null); + if ((h & n) == 0) { + if ((p.prev = loTail) == null) + lo = p; + else + loTail.next = p; + loTail = p; + ++lc; + } + else { + if ((p.prev = hiTail) == null) + hi = p; + else + hiTail.next = p; + hiTail = p; + ++hc; + } + } + ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) : + (hc != 0) ? new TreeBin(lo) : t; + hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) : + (lc != 0) ? new TreeBin(hi) : t; + } + else + ln = hn = null; + setTabAt(nextTab, i, ln); + setTabAt(nextTab, i + n, hn); + setTabAt(tab, i, fwd); + advance = true; } } } - if (!init) { // Can only happen if unsafely published. - while (p != null) { - internalPut(p.key, p.val); - p = p.next; - } - } } } + /* ---------------- Conversion from/to TreeBins -------------- */ - // ------------------------------------------------------- - - // 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); } - - - // ------------------------------------------------------- + /** + * Replaces all linked nodes in bin at given index unless table is + * too small, in which case resizes instead. + */ + private final void treeifyBin(Node[] tab, int index) { + Node b; int n, sc; + if (tab != null) { + if ((n = tab.length) < MIN_TREEIFY_CAPACITY) { + if (tab == table && (sc = sizeCtl) >= 0 && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) + transfer(tab, null); + } + else if ((b = tabAt(tab, index)) != null) { + synchronized (b) { + if (tabAt(tab, index) == b) { + TreeNode hd = null, tl = null; + for (Node e = b; e != null; e = e.next) { + TreeNode p = + new TreeNode(e.hash, e.key, e.val, + null, null); + if ((p.prev = tl) == null) + hd = p; + else + tl.next = p; + tl = p; + } + setTabAt(tab, index, new TreeBin(hd)); + } + } + } + } + } /** - * Returns an extended {@link Parallel} view of this map using the - * given executor for bulk parallel operations. - * - * @param executor the executor - * @return a parallel view + * Returns a list on non-TreeNodes replacing those in given list. */ - public Parallel parallel(ForkJoinPool executor) { - return new Parallel(executor); + static Node untreeify(Node b) { + Node hd = null, tl = null; + for (Node q = b; q != null; q = q.next) { + Node p = new Node(q.hash, q.key, q.val, null); + if (tl == null) + hd = p; + else + tl.next = p; + tl = p; + } + return hd; } + /* ---------------- TreeNodes -------------- */ + /** - * An extended view of a ConcurrentHashMap supporting bulk - * parallel operations. These operations are designed to be 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 ConcurrentHashMap are not ordered in any - * particular way, and may be processed in different orders in - * different parallel executions, the correctness of supplied - * functions should not depend on any ordering, or on any other - * objects or values that may transiently change while computation - * is in progress; and except for forEach actions, should ideally - * be side-effect-free. - * - *

- * - *

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

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. - * - *

Parallel speedups compared to sequential processing are - * common but not guaranteed. Operations involving brief - * functions on small maps may execute more slowly than sequential - * loops if the underlying work to parallelize the computation is - * more expensive than the computation itself. Similarly, - * parallelization may not lead to much actual parallelism if all - * processors are busy performing unrelated tasks. - * - *

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. + * Nodes for use in TreeBins */ - public class Parallel { - final ForkJoinPool fjp; + 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; - /** - * Returns an extended view of this map using the given - * executor for bulk parallel operations. - * - * @param executor the executor - */ - public Parallel(ForkJoinPool executor) { - this.fjp = executor; + TreeNode(int hash, K key, V val, Node next, + TreeNode parent) { + super(hash, key, val, next); + this.parent = parent; } - /** - * Performs the given action for each (key, value). - * - * @param action the action - */ - public void forEach(BiAction action) { - fjp.invoke(ForkJoinTasks.forEach - (ConcurrentHashMapV8.this, action)); + Node find(int h, Object k) { + return findTreeNode(h, k, null); } /** - * Performs the given action for each non-null transformation - * of each (key, value). - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case the action is not applied). - * @param action the action + * Returns the TreeNode (or null if not found) for the given key + * starting at given root. */ - public void forEach(BiFun transformer, - Action action) { - fjp.invoke(ForkJoinTasks.forEach - (ConcurrentHashMapV8.this, transformer, action)); + final TreeNode findTreeNode(int h, Object k, Class kc) { + if (k != null) { + TreeNode p = this; + do { + int ph, dir; K pk; TreeNode q; + TreeNode pl = p.left, pr = p.right; + if ((ph = p.hash) > h) + p = pl; + else if (ph < h) + p = pr; + else if ((pk = p.key) == k || (pk != null && k.equals(pk))) + return p; + else if (pl == null && pr == null) + break; + else if ((kc != null || + (kc = comparableClassFor(k)) != null) && + (dir = compareComparables(kc, k, pk)) != 0) + p = (dir < 0) ? pl : pr; + else if (pl == null) + p = pr; + else if (pr == null || + (q = pr.findTreeNode(h, k, kc)) == null) + p = pl; + else + return q; + } while (p != null); + } + return null; } + } - /** - * Returns a non-null result from applying the given search - * function on each (key, value), or null if none. Further - * element processing is suppressed upon success. However, - * this method does not return until other in-progress - * parallel invocations of the search function also complete. - * - * @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 search(BiFun searchFunction) { - return fjp.invoke(ForkJoinTasks.search - (ConcurrentHashMapV8.this, searchFunction)); + /* ---------------- TreeBins -------------- */ + + /** + * TreeNodes used at the heads of bins. TreeBins do not hold user + * keys or values, but instead point to list of TreeNodes and + * their root. They also maintain a parasitic read-write lock + * forcing writers (who hold bin lock) to wait for readers (who do + * not) to complete before tree restructuring operations. + */ + static final class TreeBin extends Node { + TreeNode root; + volatile TreeNode first; + volatile Thread waiter; + volatile int lockState; + // values for lockState + static final int WRITER = 1; // set while holding write lock + static final int WAITER = 2; // set when waiting for write lock + static final int READER = 4; // increment value for setting read lock + + /** + * Creates bin with initial set of nodes headed by b. + */ + TreeBin(TreeNode b) { + super(TREEBIN, null, null, null); + this.first = b; + TreeNode r = null; + for (TreeNode x = b, next; x != null; x = next) { + next = (TreeNode)x.next; + x.left = x.right = null; + if (r == null) { + x.parent = null; + x.red = false; + r = x; + } + else { + Object key = x.key; + int hash = x.hash; + Class kc = null; + for (TreeNode p = r;;) { + int dir, ph; + if ((ph = p.hash) > hash) + dir = -1; + else if (ph < hash) + dir = 1; + else if ((kc != null || + (kc = comparableClassFor(key)) != null)) + dir = compareComparables(kc, key, p.key); + else + dir = 0; + TreeNode xp = p; + if ((p = (dir <= 0) ? p.left : p.right) == null) { + x.parent = xp; + if (dir <= 0) + xp.left = x; + else + xp.right = x; + r = balanceInsertion(r, x); + break; + } + } + } + } + this.root = r; } /** - * Returns the result of accumulating the given transformation - * of all (key, value) pairs using the given reducer to - * combine values, or null if none. - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case it is not combined). - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all (key, value) pairs + * Acquires write lock for tree restructuring. */ - public U reduce(BiFun transformer, - BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduce - (ConcurrentHashMapV8.this, transformer, reducer)); + private final void lockRoot() { + if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER)) + contendedLock(); // offload to separate method } /** - * 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 + * Releases write lock for tree restructuring. */ - public double reduceToDouble(ObjectByObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return fjp.invoke(ForkJoinTasks.reduceToDouble - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + private final void unlockRoot() { + lockState = 0; } /** - * 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 using the given reducer to - * combine values, and the given basis as an identity value. + * Possibly blocks awaiting root lock. */ - public long reduceToLong(ObjectByObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return fjp.invoke(ForkJoinTasks.reduceToLong - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + private final void contendedLock() { + boolean waiting = false; + for (int s;;) { + if (((s = lockState) & WRITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) { + if (waiting) + waiter = null; + return; + } + } + else if ((s | WAITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) { + waiting = true; + waiter = Thread.currentThread(); + } + } + else if (waiting) + LockSupport.park(this); + } } /** - * 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 + * Returns matching node or null if none. Tries to search + * using tree compareisons from root, but continues linear + * search when lock not available. */ - public int reduceToInt(ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return fjp.invoke(ForkJoinTasks.reduceToInt - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + final Node find(int h, Object k) { + if (k != null) { + for (Node e = first; e != null; e = e.next) { + int s; K ek; + if (((s = lockState) & (WAITER|WRITER)) != 0) { + if (e.hash == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + } + else if (U.compareAndSwapInt(this, LOCKSTATE, s, + s + READER)) { + TreeNode r, p; + try { + p = ((r = root) == null ? null : + r.findTreeNode(h, k, null)); + } finally { + Thread w; + int ls; + do {} while (!U.compareAndSwapInt + (this, LOCKSTATE, + ls = lockState, ls - READER)); + if (ls == (READER|WAITER) && (w = waiter) != null) + LockSupport.unpark(w); + } + return p; + } + } + } + return null; } /** - * Performs the given action for each key - * - * @param action the action + * Finds or adds a node. + * @return null if added */ - public void forEachKey(Action action) { - fjp.invoke(ForkJoinTasks.forEachKey - (ConcurrentHashMapV8.this, action)); + final TreeNode putTreeVal(int h, K k, V v) { + Class kc = null; + for (TreeNode p = root;;) { + int dir, ph; K pk; TreeNode q, pr; + if (p == null) { + first = root = new TreeNode(h, k, v, null, null); + break; + } + else if ((ph = p.hash) > h) + dir = -1; + else if (ph < h) + dir = 1; + else if ((pk = p.key) == k || (pk != null && k.equals(pk))) + return p; + else if ((kc == null && + (kc = comparableClassFor(k)) == null) || + (dir = compareComparables(kc, k, pk)) == 0) { + if (p.left == null) + dir = 1; + else if ((pr = p.right) == null || + (q = pr.findTreeNode(h, k, kc)) == null) + dir = -1; + else + return q; + } + TreeNode xp = p; + if ((p = (dir < 0) ? p.left : p.right) == null) { + TreeNode x, f = first; + first = x = new TreeNode(h, k, v, f, xp); + if (f != null) + f.prev = x; + if (dir < 0) + xp.left = x; + else + xp.right = x; + if (!xp.red) + x.red = true; + else { + lockRoot(); + try { + root = balanceInsertion(root, x); + } finally { + unlockRoot(); + } + } + break; + } + } + assert checkInvariants(root); + return null; } /** - * Performs the given action for each non-null transformation - * of each key + * 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. * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case the action is not applied). - * @param action the action + * @return true if now too small so should be untreeified. */ - public void forEachKey(Fun transformer, - Action action) { - fjp.invoke(ForkJoinTasks.forEachKey - (ConcurrentHashMapV8.this, transformer, action)); + final boolean removeTreeNode(TreeNode p) { + TreeNode next = (TreeNode)p.next; + TreeNode pred = p.prev; // unlink traversal pointers + TreeNode r, rl; + if (pred == null) + first = next; + else + pred.next = next; + if (next != null) + next.prev = pred; + if (first == null) { + root = null; + return true; + } + if ((r = root) == null || r.right == null || // too small + (rl = r.left) == null || rl.left == null) + return true; + lockRoot(); + try { + TreeNode 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) + r = s; + else if (p == pp.left) + pp.left = s; + else + pp.right = s; + if (sr != null) + replacement = sr; + else + replacement = p; + } + else if (pl != null) + replacement = pl; + else if (pr != null) + replacement = pr; + else + replacement = p; + if (replacement != p) { + TreeNode pp = replacement.parent = p.parent; + if (pp == null) + r = replacement; + else if (p == pp.left) + pp.left = replacement; + else + pp.right = replacement; + p.left = p.right = p.parent = null; + } + + root = (p.red) ? r : balanceDeletion(r, replacement); + + if (p == replacement) { // detach pointers + TreeNode pp; + if ((pp = p.parent) != null) { + if (p == pp.left) + pp.left = null; + else if (p == pp.right) + pp.right = null; + p.parent = null; + } + } + } finally { + unlockRoot(); + } + assert checkInvariants(root); + return false; } - /** - * Returns a non-null result from applying the given search - * function on each key, or null if none. Further element - * processing is suppressed upon success. However, this method - * does not return until other in-progress parallel - * invocations of the search function also complete. - * - * @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 searchKeys(Fun searchFunction) { - return fjp.invoke(ForkJoinTasks.searchKeys - (ConcurrentHashMapV8.this, searchFunction)); + /* ------------------------------------------------------------ */ + // Red-black tree methods, all adapted from CLR + + static TreeNode rotateLeft(TreeNode root, + TreeNode p) { + TreeNode r, pp, rl; + if (p != null && (r = p.right) != null) { + if ((rl = p.right = r.left) != null) + rl.parent = p; + if ((pp = r.parent = p.parent) == null) + (root = r).red = false; + else if (pp.left == p) + pp.left = r; + else + pp.right = r; + r.left = p; + p.parent = r; + } + return root; } - /** - * Returns the result of accumulating all keys using the given - * reducer to combine values, or null if none. - * - * @param reducer a commutative associative combining function - * @return the result of accumulating all keys using the given - * reducer to combine values, or null if none - */ - public K reduceKeys(BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduceKeys - (ConcurrentHashMapV8.this, reducer)); + static TreeNode rotateRight(TreeNode root, + TreeNode p) { + TreeNode l, pp, lr; + if (p != null && (l = p.left) != null) { + if ((lr = p.left = l.right) != null) + lr.parent = p; + if ((pp = l.parent = p.parent) == null) + (root = l).red = false; + else if (pp.right == p) + pp.right = l; + else + pp.left = l; + l.right = p; + p.parent = l; + } + return root; } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, or - * null if none. - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case it is not combined). - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - public U reduceKeys(Fun transformer, - BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduceKeys - (ConcurrentHashMapV8.this, transformer, reducer)); + static TreeNode balanceInsertion(TreeNode root, + TreeNode x) { + x.red = true; + for (TreeNode xp, xpp, xppl, xppr;;) { + if ((xp = x.parent) == null) { + x.red = false; + return x; + } + else if (!xp.red || (xpp = xp.parent) == null) + return root; + if (xp == (xppl = xpp.left)) { + if ((xppr = xpp.right) != null && xppr.red) { + xppr.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.right) { + root = rotateLeft(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateRight(root, xpp); + } + } + } + } + else { + if (xppl != null && xppl.red) { + xppl.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.left) { + root = rotateRight(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateLeft(root, xpp); + } + } + } + } + } } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - public double reduceKeysToDouble(ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return fjp.invoke(ForkJoinTasks.reduceKeysToDouble - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + static TreeNode balanceDeletion(TreeNode root, + TreeNode x) { + for (TreeNode xp, xpl, xpr;;) { + if (x == null || x == root) + return root; + else if ((xp = x.parent) == null) { + x.red = false; + return x; + } + else if (x.red) { + x.red = false; + return root; + } + else if ((xpl = xp.left) == x) { + if ((xpr = xp.right) != null && xpr.red) { + xpr.red = false; + xp.red = true; + root = rotateLeft(root, xp); + xpr = (xp = x.parent) == null ? null : xp.right; + } + if (xpr == null) + x = xp; + else { + TreeNode sl = xpr.left, sr = xpr.right; + if ((sr == null || !sr.red) && + (sl == null || !sl.red)) { + xpr.red = true; + x = xp; + } + else { + if (sr == null || !sr.red) { + if (sl != null) + sl.red = false; + xpr.red = true; + root = rotateRight(root, xpr); + xpr = (xp = x.parent) == null ? + null : xp.right; + } + if (xpr != null) { + xpr.red = (xp == null) ? false : xp.red; + if ((sr = xpr.right) != null) + sr.red = false; + } + if (xp != null) { + xp.red = false; + root = rotateLeft(root, xp); + } + x = root; + } + } + } + else { // symmetric + if (xpl != null && xpl.red) { + xpl.red = false; + xp.red = true; + root = rotateRight(root, xp); + xpl = (xp = x.parent) == null ? null : xp.left; + } + if (xpl == null) + x = xp; + else { + TreeNode sl = xpl.left, sr = xpl.right; + if ((sl == null || !sl.red) && + (sr == null || !sr.red)) { + xpl.red = true; + x = xp; + } + else { + if (sl == null || !sl.red) { + if (sr != null) + sr.red = false; + xpl.red = true; + root = rotateLeft(root, xpl); + xpl = (xp = x.parent) == null ? + null : xp.left; + } + if (xpl != null) { + xpl.red = (xp == null) ? false : xp.red; + if ((sl = xpl.left) != null) + sl.red = false; + } + if (xp != null) { + xp.red = false; + root = rotateRight(root, xp); + } + x = root; + } + } + } + } } /** - * 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 + * Recursive invariant check */ - public long reduceKeysToLong(ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return fjp.invoke(ForkJoinTasks.reduceKeysToLong - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + static boolean checkInvariants(TreeNode t) { + TreeNode tp = t.parent, tl = t.left, tr = t.right, + tb = t.prev, tn = (TreeNode)t.next; + if (tb != null && tb.next != t) + return false; + if (tn != null && tn.prev != t) + return false; + if (tp != null && t != tp.left && t != tp.right) + return false; + if (tl != null && (tl.parent != t || tl.hash > t.hash)) + return false; + if (tr != null && (tr.parent != t || tr.hash < t.hash)) + return false; + if (t.red && tl != null && tl.red && tr != null && tr.red) + return false; + if (tl != null && !checkInvariants(tl)) + return false; + if (tr != null && !checkInvariants(tr)) + return false; + return true; } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - public int reduceKeysToInt(ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return fjp.invoke(ForkJoinTasks.reduceKeysToInt - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + private static final sun.misc.Unsafe U; + private static final long LOCKSTATE; + static { + try { + U = getUnsafe(); + Class k = TreeBin.class; + LOCKSTATE = U.objectFieldOffset + (k.getDeclaredField("lockState")); + } catch (Exception e) { + throw new Error(e); + } } + } - /** - * Performs the given action for each value - * - * @param action the action - */ - public void forEachValue(Action action) { - fjp.invoke(ForkJoinTasks.forEachValue - (ConcurrentHashMapV8.this, action)); + /* ----------------Table Traversal -------------- */ + + /** + * Encapsulates traversal for methods such as containsValue; also + * serves as a base class for other iterators and spliterators. + * + * Method advance visits once each still-valid node that was + * reachable upon iterator construction. It might miss some that + * were added to a bin after the bin was visited, which is OK wrt + * consistency guarantees. Maintaining this property in the face + * of possible ongoing resizes requires a fair amount of + * bookkeeping state that is difficult to optimize away amidst + * volatile accesses. Even so, traversal maintains reasonable + * throughput. + * + * Normally, iteration proceeds bin-by-bin traversing lists. + * However, if the table has been resized, then all future steps + * must traverse both the bin at the current index as well as at + * (index + baseSize); and so on for further resizings. To + * paranoically cope with potential sharing by users of iterators + * across threads, iteration terminates if a bounds checks fails + * for a table read. + */ + static class Traverser { + Node[] tab; // current table; updated if resized + Node next; // the next entry to use + int index; // index of bin to use next + int baseIndex; // current index of initial table + int baseLimit; // index bound for initial table + final int baseSize; // initial table size + + Traverser(Node[] tab, int size, int index, int limit) { + this.tab = tab; + this.baseSize = size; + this.baseIndex = this.index = index; + this.baseLimit = limit; + this.next = null; } /** - * Performs the given action for each non-null transformation - * of each value - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case the action is not applied). - */ - public void forEachValue(Fun transformer, - Action action) { - fjp.invoke(ForkJoinTasks.forEachValue - (ConcurrentHashMapV8.this, transformer, action)); + * Advances if possible, returning next valid node, or null if none. + */ + final Node advance() { + Node e; + if ((e = next) != null) + e = e.next; + for (;;) { + Node[] t; int i, n; K ek; // must use locals in checks + if (e != null) + return next = e; + if (baseIndex >= baseLimit || (t = tab) == null || + (n = t.length) <= (i = index) || i < 0) + return next = null; + if ((e = tabAt(t, index)) != null && e.hash < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + e = null; + continue; + } + else if (e instanceof TreeBin) + e = ((TreeBin)e).first; + else + e = null; + } + if ((index += baseSize) >= n) + index = ++baseIndex; // visit upper slots if present + } } + } - /** - * Returns a non-null result from applying the given search - * function on each value, or null if none. Further element - * processing is suppressed upon success. However, this method - * does not return until other in-progress parallel - * invocations of the search function also complete. - * - * @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 searchValues(Fun searchFunction) { - return fjp.invoke(ForkJoinTasks.searchValues - (ConcurrentHashMapV8.this, searchFunction)); + /** + * Base of key, value, and entry Iterators. Adds fields to + * Traverser to support iterator.remove. + */ + static class BaseIterator extends Traverser { + final ConcurrentHashMapV8 map; + Node lastReturned; + BaseIterator(Node[] tab, int size, int index, int limit, + ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + advance(); } - /** - * Returns the result of accumulating all values using the - * given reducer to combine values, or null if none. - * - * @param reducer a commutative associative combining function - * @return the result of accumulating all values - */ - public V reduceValues(BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduceValues - (ConcurrentHashMapV8.this, reducer)); + public final boolean hasNext() { return next != null; } + public final boolean hasMoreElements() { return next != null; } + + public final void remove() { + Node p; + if ((p = lastReturned) == null) + throw new IllegalStateException(); + lastReturned = null; + map.replaceNode(p.key, null, null); } + } - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, or - * null if none. - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case it is not combined). - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public U reduceValues(Fun transformer, - BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduceValues - (ConcurrentHashMapV8.this, transformer, reducer)); + static final class KeyIterator extends BaseIterator + implements Iterator, Enumeration { + KeyIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); } - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public double reduceValuesToDouble(ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return fjp.invoke(ForkJoinTasks.reduceValuesToDouble - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + public final K next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + K k = p.key; + lastReturned = p; + advance(); + return k; } - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public long reduceValuesToLong(ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return fjp.invoke(ForkJoinTasks.reduceValuesToLong - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + public final K nextElement() { return next(); } + } + + static final class ValueIterator extends BaseIterator + implements Iterator, Enumeration { + ValueIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); } - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public int reduceValuesToInt(ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return fjp.invoke(ForkJoinTasks.reduceValuesToInt - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + public final V next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + V v = p.val; + lastReturned = p; + advance(); + return v; } - /** - * Perform the given action for each entry - * - * @param action the action - */ - public void forEachEntry(Action> action) { - fjp.invoke(ForkJoinTasks.forEachEntry - (ConcurrentHashMapV8.this, action)); + public final V nextElement() { return next(); } + } + + static final class EntryIterator extends BaseIterator + implements Iterator> { + EntryIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); } - /** - * Perform the given action for each non-null transformation - * of each entry - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case the action is not applied). - * @param action the action - */ - public void forEachEntry(Fun, ? extends U> transformer, - Action action) { - fjp.invoke(ForkJoinTasks.forEachEntry - (ConcurrentHashMapV8.this, transformer, action)); + public final Map.Entry next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + K k = p.key; + V v = p.val; + lastReturned = p; + advance(); + return new MapEntry(k, v, map); } + } - /** - * Returns a non-null result from applying the given search - * function on each entry, or null if none. Further element - * processing is suppressed upon success. However, this method - * does not return until other in-progress parallel - * invocations of the search function also complete. - * - * @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 searchEntries(Fun, ? extends U> searchFunction) { - return fjp.invoke(ForkJoinTasks.searchEntries - (ConcurrentHashMapV8.this, searchFunction)); + /** + * Exported Entry for EntryIterator + */ + 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 K getKey() { return key; } + public V getValue() { return val; } + public int hashCode() { return key.hashCode() ^ val.hashCode(); } + public String toString() { return key + "=" + val; } - /** - * 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 reduceEntries(BiFun, Map.Entry, ? extends Map.Entry> reducer) { - return fjp.invoke(ForkJoinTasks.reduceEntries - (ConcurrentHashMapV8.this, reducer)); + public boolean equals(Object o) { + Object k, v; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == key || k.equals(key)) && + (v == val || v.equals(val))); } /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * or null if none. - * - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case it is not combined). - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries + * 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 U reduceEntries(Fun, ? extends U> transformer, - BiFun reducer) { - return fjp.invoke(ForkJoinTasks.reduceEntries - (ConcurrentHashMapV8.this, transformer, reducer)); + public V setValue(V value) { + if (value == null) throw new NullPointerException(); + V v = val; + val = value; + map.put(key, value); + return v; } + } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - public double reduceEntriesToDouble(ObjectToDouble> transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return fjp.invoke(ForkJoinTasks.reduceEntriesToDouble - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + static final class KeySpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + KeySpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; + } + + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new KeySpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1); } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - public long reduceEntriesToLong(ObjectToLong> transformer, - long basis, - LongByLongToLong reducer) { - return fjp.invoke(ForkJoinTasks.reduceEntriesToLong - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + public void forEachRemaining(Action action) { + if (action == null) throw new NullPointerException(); + for (Node p; (p = advance()) != null;) + action.apply(p.key); } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - public int reduceEntriesToInt(ObjectToInt> transformer, - int basis, - IntByIntToInt reducer) { - return fjp.invoke(ForkJoinTasks.reduceEntriesToInt - (ConcurrentHashMapV8.this, transformer, basis, reducer)); + public boolean tryAdvance(Action action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(p.key); + return true; } + + public long estimateSize() { return est; } + } - // --------------------------------------------------------------------- + static final class ValueSpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + ValueSpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; + } - /** - * Predefined tasks for performing bulk parallel operations on - * ConcurrentHashMaps. These tasks follow the forms and rules used - * in class {@link Parallel}. 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, or combining with other tasks. - */ - public static class ForkJoinTasks { - private ForkJoinTasks() {} + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new ValueSpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1); + } - /** - * 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) { + public void forEachRemaining(Action action) { if (action == null) throw new NullPointerException(); - return new ForEachMappingTask(map, action); + for (Node p; (p = advance()) != null;) + action.apply(p.val); } - /** - * 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 of 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, transformer, action); + public boolean tryAdvance(Action action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(p.val); + return true; } - /** - * 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. Further element processing - * is suppressed upon success. However, this method does not - * return until other in-progress parallel invocations of the - * search function also complete. - * - * @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, searchFunction, - new AtomicReference()); + public long estimateSize() { return est; } + + } + + static final class EntrySpliterator extends Traverser + implements ConcurrentHashMapSpliterator> { + final ConcurrentHashMapV8 map; // To export MapEntry + long est; // size estimate + EntrySpliterator(Node[] tab, int size, int index, int limit, + long est, ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + this.est = est; } - /** - * 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 of 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, transformer, reducer); + public ConcurrentHashMapSpliterator> trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new EntrySpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1, map); } - /** - * 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, transformer, basis, reducer); + public void forEachRemaining(Action> action) { + if (action == null) throw new NullPointerException(); + for (Node p; (p = advance()) != null; ) + action.apply(new MapEntry(p.key, p.val, map)); } - /** - * 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, transformer, basis, reducer); + public boolean tryAdvance(Action> action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(new MapEntry(p.key, p.val, map)); + return true; } + public long estimateSize() { return est; } + + } + + // Parallel bulk operations + + /** + * Computes initial batch value for bulk tasks. The returned value + * is approximately exp2 of the number of times (minus one) to + * split task by two before executing leaf action. This value is + * faster to compute and more convenient to use as a guide to + * splitting than is the depth, since it is used while dividing by + * two anyway. + */ + final int batchFor(long b) { + long n; + if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b) + return 0; + int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4 + return (b <= 0L || (n /= b) >= sp) ? sp : (int)n; + } + + /** + * Performs the given action for each (key, value). + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param action the action + * @since 1.8 + */ + public void forEach(long parallelismThreshold, + BiAction action) { + if (action == null) throw new NullPointerException(); + new ForEachMappingTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); + } + + /** + * Performs the given action for each non-null transformation + * of each (key, value). + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case the action is not applied) + * @param action the action + * @since 1.8 + */ + public void forEach(long parallelismThreshold, + BiFun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedMappingTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); + } + + /** + * Returns a non-null result from applying the given search + * function on each (key, value), or null if none. Upon + * success, further element processing is suppressed and the + * results of any other parallel invocations of the search + * function are ignored. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param searchFunction a function returning a non-null + * result on success, else null + * @return a non-null result from applying the given search + * function on each (key, value), or null if none + * @since 1.8 + */ + public U search(long parallelismThreshold, + BiFun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchMappingsTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all (key, value) pairs using the given reducer to + * combine values, or null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case it is not combined) + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all (key, value) pairs + * @since 1.8 + */ + public U reduce(long parallelismThreshold, + BiFun transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all (key, value) pairs using the given reducer to + * combine values, and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all (key, value) pairs + * @since 1.8 + */ + public double reduceToDoubleIn(long parallelismThreshold, + ObjectByObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all (key, value) pairs using the given reducer to + * combine values, and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all (key, value) pairs + * @since 1.8 + */ + public long reduceToLong(long parallelismThreshold, + ObjectByObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all (key, value) pairs using the given reducer to + * combine values, and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all (key, value) pairs + * @since 1.8 + */ + public int reduceToInt(long parallelismThreshold, + ObjectByObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Performs the given action for each key. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param action the action + * @since 1.8 + */ + public void forEachKey(long parallelismThreshold, + Action action) { + if (action == null) throw new NullPointerException(); + new ForEachKeyTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); + } + + /** + * Performs the given action for each non-null transformation + * of each key. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case the action is not applied) + * @param action the action + * @since 1.8 + */ + public void forEachKey(long parallelismThreshold, + Fun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedKeyTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); + } + + /** + * Returns a non-null result from applying the given search + * function on each key, or null if none. Upon success, + * further element processing is suppressed and the results of + * any other parallel invocations of the search function are + * ignored. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param searchFunction a function returning a non-null + * result on success, else null + * @return a non-null result from applying the given search + * function on each key, or null if none + * @since 1.8 + */ + public U searchKeys(long parallelismThreshold, + Fun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); + } + + /** + * Returns the result of accumulating all keys using the given + * reducer to combine values, or null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param reducer a commutative associative combining function + * @return the result of accumulating all keys using the given + * reducer to combine values, or null if none + * @since 1.8 + */ + public K reduceKeys(long parallelismThreshold, + BiFun reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all keys using the given reducer to combine values, or + * null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case it is not combined) + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all keys + * @since 1.8 + */ + public U reduceKeys(long parallelismThreshold, + Fun transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all keys using the given reducer to combine values, and + * the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all keys + * @since 1.8 + */ + public double reduceKeysToDouble(long parallelismThreshold, + ObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all keys using the given reducer to combine values, and + * the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all keys + * @since 1.8 + */ + public long reduceKeysToLong(long parallelismThreshold, + ObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all keys using the given reducer to combine values, and + * the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all keys + * @since 1.8 + */ + public int reduceKeysToInt(long parallelismThreshold, + ObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Performs the given action for each value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param action the action + * @since 1.8 + */ + public void forEachValue(long parallelismThreshold, + Action action) { + if (action == null) + throw new NullPointerException(); + new ForEachValueTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); + } + + /** + * Performs the given action for each non-null transformation + * of each value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case the action is not applied) + * @param action the action + * @since 1.8 + */ + public void forEachValue(long parallelismThreshold, + Fun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedValueTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); + } + + /** + * Returns a non-null result from applying the given search + * function on each value, or null if none. Upon success, + * further element processing is suppressed and the results of + * any other parallel invocations of the search function are + * ignored. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param searchFunction a function returning a non-null + * result on success, else null + * @return a non-null result from applying the given search + * function on each value, or null if none + * @since 1.8 + */ + public U searchValues(long parallelismThreshold, + Fun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); + } + + /** + * Returns the result of accumulating all values using the + * given reducer to combine values, or null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param reducer a commutative associative combining function + * @return the result of accumulating all values + * @since 1.8 + */ + public V reduceValues(long parallelismThreshold, + BiFun reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all values using the given reducer to combine values, or + * null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case it is not combined) + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all values + * @since 1.8 + */ + public U reduceValues(long parallelismThreshold, + Fun transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all values using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all values + * @since 1.8 + */ + public double reduceValuesToDouble(long parallelismThreshold, + ObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all values using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all values + * @since 1.8 + */ + public long reduceValuesToLong(long parallelismThreshold, + ObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all values using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all values + * @since 1.8 + */ + public int reduceValuesToInt(long parallelismThreshold, + ObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Performs the given action for each entry. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param action the action + * @since 1.8 + */ + public void forEachEntry(long parallelismThreshold, + Action> action) { + if (action == null) throw new NullPointerException(); + new ForEachEntryTask(null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); + } + + /** + * Performs the given action for each non-null transformation + * of each entry. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case the action is not applied) + * @param action the action + * @since 1.8 + */ + public void forEachEntry(long parallelismThreshold, + Fun, ? extends U> transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedEntryTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); + } + + /** + * Returns a non-null result from applying the given search + * function on each entry, or null if none. Upon success, + * further element processing is suppressed and the results of + * any other parallel invocations of the search function are + * ignored. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param searchFunction a function returning a non-null + * result on success, else null + * @return a non-null result from applying the given search + * function on each entry, or null if none + * @since 1.8 + */ + public U searchEntries(long parallelismThreshold, + Fun, ? extends U> searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); + } + + /** + * Returns the result of accumulating all entries using the + * given reducer to combine values, or null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param reducer a commutative associative combining function + * @return the result of accumulating all entries + * @since 1.8 + */ + public Map.Entry reduceEntries(long parallelismThreshold, + BiFun, Map.Entry, ? extends Map.Entry> reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all entries using the given reducer to combine values, + * or null if none. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element, or null if there is no transformation (in + * which case it is not combined) + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all entries + * @since 1.8 + */ + public U reduceEntries(long parallelismThreshold, + Fun, ? extends U> transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all entries using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all entries + * @since 1.8 + */ + public double reduceEntriesToDouble(long parallelismThreshold, + ObjectToDouble> transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all entries using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all entries + * @since 1.8 + */ + public long reduceEntriesToLong(long parallelismThreshold, + ObjectToLong> transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all entries using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all entries + * @since 1.8 + */ + public int reduceEntriesToInt(long parallelismThreshold, + ObjectToInt> transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + + /* ----------------Views -------------- */ + + /** + * Base class for views. + */ + abstract static class CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 7249069246763182397L; + final ConcurrentHashMapV8 map; + CollectionView(ConcurrentHashMapV8 map) { this.map = map; } + /** - * 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. + * Returns the map backing this view. * - * @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 + * @return the map backing this view */ - public static ForkJoinTask reduceToInt - (ConcurrentHashMapV8 map, - ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceMappingsToIntTask - (map, transformer, basis, reducer); - } + public ConcurrentHashMapV8 getMap() { return map; } /** - * Returns a task that when invoked, performs the given action - * for each key - * - * @param map the map - * @param action the action - * @return the task + * Removes all of the elements from this view, by removing all + * the mappings from the map backing this view. */ - public static ForkJoinTask forEachKey - (ConcurrentHashMapV8 map, - Action action) { - if (action == null) throw new NullPointerException(); - return new ForEachKeyTask(map, action); - } + public final void clear() { map.clear(); } + public final int size() { return map.size(); } + public final boolean isEmpty() { return map.isEmpty(); } + // implementations below rely on concrete classes supplying these + // abstract methods /** - * Returns 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 of 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, transformer, action); + * 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. + */ + 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 > MAX_ARRAY_SIZE) + throw new OutOfMemoryError(oomeMsg); + int n = (int)sz; + Object[] r = new Object[n]; + int i = 0; + for (E e : this) { + if (i == n) { + if (n >= MAX_ARRAY_SIZE) + throw new OutOfMemoryError(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++] = e; + } + return (i == n) ? r : Arrays.copyOf(r, i); } - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each key, or - * null if none. Further element processing is suppressed - * upon success. However, this method does not return until - * other in-progress parallel invocations of the search - * function also complete. - * - * @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, searchFunction, - new AtomicReference()); + @SuppressWarnings("unchecked") + public final T[] toArray(T[] a) { + long sz = map.mappingCount(); + if (sz > 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; + for (E e : this) { + 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)e; + } + if (a == r && i < n) { + r[i] = null; // null-terminate + return r; + } + return (i == n) ? r : Arrays.copyOf(r, i); } /** - * Returns a task that when invoked, returns the result of - * accumulating all keys using the given reducer to combine - * values, or null if none. + * Returns a string representation of this collection. + * The string representation consists of the string representations + * of the collection's elements in the order they are returned by + * its iterator, enclosed in square brackets ({@code "[]"}). + * Adjacent elements are separated by the characters {@code ", "} + * (comma and space). Elements are converted to strings as by + * {@link String#valueOf(Object)}. * - * @param map the map - * @param reducer a commutative associative combining function - * @return the task + * @return a string representation of this collection */ - public static ForkJoinTask reduceKeys - (ConcurrentHashMapV8 map, - BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - return new ReduceKeysTask - (map, reducer); + 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(); } - /** - * 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 of 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, transformer, reducer); + + public final boolean containsAll(Collection c) { + if (c != this) { + for (Object e : c) { + if (e == null || !contains(e)) + return false; + } + } + return true; } - /** - * 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, transformer, basis, reducer); + 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; } - /** - * 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, transformer, basis, reducer); + 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; } - /** - * 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, transformer, basis, reducer); + } + + /** + * 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() keySet()}, + * {@link #keySet(Object) keySet(V)}, + * {@link #newKeySet() newKeySet()}, + * {@link #newKeySet(int) newKeySet(int)}. + * + * @since 1.8 + */ + public static class KeySetView extends CollectionView + 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 a task that when invoked, performs the given action - * for each value + * Returns the default mapped value for additions, + * or {@code null} if additions are not supported. * - * @param map the map - * @param action the action + * @return the default mapped value for additions, or {@code null} + * if not supported */ - public static ForkJoinTask forEachValue - (ConcurrentHashMapV8 map, - Action action) { - if (action == null) throw new NullPointerException(); - return new ForEachValueTask(map, action); - } + public V getMappedValue() { return value; } /** - * 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 of there is no transformation (in - * which case the action is not applied). - * @param action the action + * {@inheritDoc} + * @throws NullPointerException if the specified key is null */ - public static ForkJoinTask forEachValue - (ConcurrentHashMapV8 map, - Fun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - return new ForEachTransformedValueTask - (map, transformer, action); - } + public boolean contains(Object o) { return map.containsKey(o); } /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each value, or - * null if none. Further element processing is suppressed - * upon success. However, this method does not return until - * other in-progress parallel invocations of the search - * function also complete. - * - * @param map the map - * @param searchFunction a function returning a non-null - * result on success, else null - * @return the task + * Removes the key from this map view, by removing the key (and its + * corresponding value) from the backing map. This method does + * nothing if the key is not in the map. * + * @param o the key to be removed from the backing map + * @return {@code true} if the backing map contained the specified key + * @throws NullPointerException if the specified key is null */ - public static ForkJoinTask searchValues - (ConcurrentHashMapV8 map, - Fun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - return new SearchValuesTask - (map, searchFunction, - new AtomicReference()); - } + public boolean remove(Object o) { return map.remove(o) != null; } /** - * 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 + * @return an iterator over the keys of the backing map */ - public static ForkJoinTask reduceValues - (ConcurrentHashMapV8 map, - BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - return new ReduceValuesTask - (map, reducer); + public Iterator iterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + int f = (t = m.table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, m); } /** - * 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. + * Adds the specified key to this set view by mapping the key to + * the default mapped value in the backing map, if defined. * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null of there is no transformation (in - * which case it is not combined). - * @param reducer a commutative associative combining function - * @return the task + * @param e key to be added + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the specified key is null + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided */ - public static ForkJoinTask reduceValues - (ConcurrentHashMapV8 map, - Fun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesTask - (map, transformer, reducer); + public boolean add(K e) { + V v; + if ((v = value) == null) + throw new UnsupportedOperationException(); + return map.putVal(e, v, true) == null; } /** - * 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. + * Adds all of the elements in the specified collection to this set, + * as if by calling {@link #add} on each one. * - * @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 + * @param c the elements to be inserted into this set + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the collection or any of its + * elements are {@code null} + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided */ - public static ForkJoinTask reduceValuesToDouble - (ConcurrentHashMapV8 map, - ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesToDoubleTask - (map, transformer, basis, reducer); + public boolean addAll(Collection c) { + boolean added = false; + V v; + if ((v = value) == null) + throw new UnsupportedOperationException(); + for (K e : c) { + if (map.putVal(e, v, true) == null) + added = true; + } + return added; } - /** - * 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, transformer, basis, reducer); + public int hashCode() { + int h = 0; + for (K e : this) + h += e.hashCode(); + return h; } - /** - * 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, transformer, basis, reducer); + public boolean equals(Object o) { + Set c; + return ((o instanceof Set) && + ((c = (Set)o) == this || + (containsAll(c) && c.containsAll(this)))); } - /** - * 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, action); + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new KeySpliterator(t, f, 0, f, n < 0L ? 0L : n); } - /** - * 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 of 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, transformer, action); + public void forEach(Action action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(p.key); + } } + } - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each entry, or - * null if none. Further element processing is suppressed - * upon success. However, this method does not return until - * other in-progress parallel invocations of the search - * function also complete. - * - * @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, searchFunction, - new AtomicReference()); + /** + * 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()}. + */ + static final class ValuesView extends CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; + ValuesView(ConcurrentHashMapV8 map) { super(map); } + public final boolean contains(Object o) { + return map.containsValue(o); } - /** - * 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, reducer); + public final boolean remove(Object o) { + if (o != null) { + for (Iterator it = iterator(); it.hasNext();) { + if (o.equals(it.next())) { + it.remove(); + return true; + } + } + } + return false; } - /** - * 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 of 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, transformer, reducer); + public final Iterator iterator() { + ConcurrentHashMapV8 m = map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, m); } - /** - * 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, transformer, basis, reducer); + public final boolean add(V e) { + throw new UnsupportedOperationException(); + } + public final boolean addAll(Collection c) { + throw new UnsupportedOperationException(); } - /** - * 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, transformer, basis, reducer); + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new ValueSpliterator(t, f, 0, f, n < 0L ? 0L : n); } - /** - * 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, transformer, basis, reducer); + public void forEach(Action action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(p.val); + } } } - // ------------------------------------------------------- - /** - * Base for FJ tasks for bulk operations. This adds a variant of - * CountedCompleters and some split and merge bookeeping to - * iterator functionality. The forEach and reduce methods are - * similar to those illustrated in CountedCompleter documentation, - * except that bottom-up reduction completions perform them within - * their compute methods. The search methods are like forEach - * except they continually poll for success and exit early. Also, - * exceptions are handled in a simpler manner, by just trying to - * complete root task exceptionally. - */ - static abstract class BulkTask extends Traverser { - final BulkTask parent; // completion target - int batch; // split control - int pending; // completion control + * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value) + * entries. This class cannot be directly instantiated. See + * {@link #entrySet()}. + */ + static final class EntrySetView extends CollectionView> + implements Set>, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; + EntrySetView(ConcurrentHashMapV8 map) { super(map); } - /** Constructor for root tasks */ - BulkTask(ConcurrentHashMapV8 map) { - super(map); - this.parent = null; - this.batch = -1; // force call to batch() on execution + public boolean contains(Object o) { + Object k, v, r; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (r = map.get(k)) != null && + (v = e.getValue()) != null && + (v == r || v.equals(r))); } - /** Constructor for subtasks */ - BulkTask(BulkTask parent, int batch, boolean split) { - super(parent, split); - this.parent = parent; - this.batch = batch; + public boolean remove(Object o) { + Object k, v; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + map.remove(k, v)); } - // FJ methods - /** - * Propagate completion. Note that all reduce actions - * bypass this method to combine while completing. + * @return an iterator over the entries of the backing map */ - final void tryComplete() { - BulkTask a = this, s = a; - for (int c;;) { - if ((c = a.pending) == 0) { - if ((a = (s = a).parent) == null) { - s.quietlyComplete(); - break; - } - } - else if (U.compareAndSwapInt(a, PENDING, c, c - 1)) - break; - } + public Iterator> iterator() { + ConcurrentHashMapV8 m = map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new EntryIterator(t, f, 0, f, m); } - /** - * Force root task to throw exception unless already complete. - */ - final void tryAbortComputation(Throwable ex) { - for (BulkTask a = this;;) { - BulkTask p = a.parent; - if (p == null) { - a.completeExceptionally(ex); - break; - } - a = p; - } + public boolean add(Entry e) { + return map.putVal(e.getKey(), e.getValue(), false) == null; } - public final boolean exec() { - try { - compute(); - } - catch (Throwable ex) { - tryAbortComputation(ex); + public boolean addAll(Collection> c) { + boolean added = false; + for (Entry e : c) { + if (add(e)) + added = true; } - return false; + return added; } - public abstract void compute(); + public final int hashCode() { + int h = 0; + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + h += p.hashCode(); + } + } + return h; + } - // utilities + public final boolean equals(Object o) { + Set c; + return ((o instanceof Set) && + ((c = (Set)o) == this || + (containsAll(c) && c.containsAll(this)))); + } - /** CompareAndSet pending count */ - final boolean casPending(int cmp, int val) { - return U.compareAndSwapInt(this, PENDING, cmp, val); + public ConcurrentHashMapSpliterator> spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new EntrySpliterator(t, f, 0, f, n < 0L ? 0L : n, m); } - /** - * Return 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 batch() { - int b = batch; - if (b < 0) { - long n = map.counter.sum(); - int sp = getPool().getParallelism() << 3; // slack of 8 - b = batch = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp; + public void forEach(Action> action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(new MapEntry(p.key, p.val, map)); } - return b; } - /** - * Error message for hoisted null checks of functions - */ - static final String NullFunctionMessage = - "Unexpected null function"; + } - /** - * Return exportable snapshot entry - */ - static AbstractMap.SimpleEntry entryFor(K k, V v) { - return new AbstractMap.SimpleEntry(k, v); + // ------------------------------------------------------- + + /** + * Base class for bulk tasks. Repeats some fields and code from + * class Traverser, because we need to subclass CountedCompleter. + */ + abstract static class BulkTask extends CountedCompleter { + Node[] tab; // same as Traverser + Node next; + int index; + int baseIndex; + int baseLimit; + final int baseSize; + int batch; // split control + + BulkTask(BulkTask par, int b, int i, int f, Node[] t) { + super(par); + this.batch = b; + this.index = this.baseIndex = i; + if ((this.tab = t) == null) + this.baseSize = this.baseLimit = 0; + else if (par == null) + this.baseSize = this.baseLimit = t.length; + else { + this.baseLimit = f; + this.baseSize = par.baseSize; + } } - // Unsafe mechanics - private static final sun.misc.Unsafe U; - private static final long PENDING; - static { - try { - U = sun.misc.Unsafe.getUnsafe(); - PENDING = U.objectFieldOffset - (BulkTask.class.getDeclaredField("pending")); - } catch (Exception e) { - throw new Error(e); + /** + * Same as Traverser version + */ + final Node advance() { + Node e; + if ((e = next) != null) + e = e.next; + for (;;) { + Node[] t; int i, n; K ek; // must use locals in checks + if (e != null) + return next = e; + if (baseIndex >= baseLimit || (t = tab) == null || + (n = t.length) <= (i = index) || i < 0) + return next = null; + if ((e = tabAt(t, index)) != null && e.hash < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + e = null; + continue; + } + else if (e instanceof TreeBin) + e = ((TreeBin)e).first; + else + e = null; + } + if ((index += baseSize) >= n) + index = ++baseIndex; // visit upper slots if present } } } @@ -4939,1796 +4603,1544 @@ public class ConcurrentHashMapV8 /* * Task classes. Coded in a regular but ugly format/style to * simplify checks that each variant differs in the right way from - * others. + * 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 BulkTask { - final Action action; - ForEachKeyTask - (ConcurrentHashMapV8 m, - Action action) { - super(m); - this.action = action; - } + final Action action; ForEachKeyTask - (BulkTask p, int b, boolean split, - Action action) { - super(p, b, split); + (BulkTask p, int b, int i, int f, Node[] t, + Action action) { + super(p, b, i, f, t); this.action = action; } public final void compute() { - final Action action = this.action; - if (action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachKeyTask(this, b >>>= 1, true, action).fork(); - } - while (advance() != null) - action.apply((K)nextKey); - tryComplete(); + final Action action; + if ((action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachKeyTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null;) + action.apply(p.key); + propagateCompletion(); + } } } + @SuppressWarnings("serial") static final class ForEachValueTask extends BulkTask { - final Action action; - ForEachValueTask - (ConcurrentHashMapV8 m, - Action action) { - super(m); - this.action = action; - } + final Action action; ForEachValueTask - (BulkTask p, int b, boolean split, - Action action) { - super(p, b, split); + (BulkTask p, int b, int i, int f, Node[] t, + Action action) { + super(p, b, i, f, t); this.action = action; } public final void compute() { - final Action action = this.action; - if (action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachValueTask(this, b >>>= 1, true, action).fork(); - } - Object v; - while ((v = advance()) != null) - action.apply((V)v); - tryComplete(); + final Action action; + if ((action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachValueTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null;) + action.apply(p.val); + propagateCompletion(); + } } } + @SuppressWarnings("serial") static final class ForEachEntryTask extends BulkTask { - final Action> action; - ForEachEntryTask - (ConcurrentHashMapV8 m, - Action> action) { - super(m); - this.action = action; - } + final Action> action; ForEachEntryTask - (BulkTask p, int b, boolean split, - Action> action) { - super(p, b, split); + (BulkTask p, int b, int i, int f, Node[] t, + Action> action) { + super(p, b, i, f, t); this.action = action; } public final void compute() { - final Action> action = this.action; - if (action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachEntryTask(this, b >>>= 1, true, action).fork(); - } - Object v; - while ((v = advance()) != null) - action.apply(entryFor((K)nextKey, (V)v)); - tryComplete(); + final Action> action; + if ((action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachEntryTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null; ) + action.apply(p); + propagateCompletion(); + } } } + @SuppressWarnings("serial") static final class ForEachMappingTask extends BulkTask { - final BiAction action; - ForEachMappingTask - (ConcurrentHashMapV8 m, - BiAction action) { - super(m); - this.action = action; - } + final BiAction action; ForEachMappingTask - (BulkTask p, int b, boolean split, - BiAction action) { - super(p, b, split); + (BulkTask p, int b, int i, int f, Node[] t, + BiAction action) { + super(p, b, i, f, t); this.action = action; } - public final void compute() { - final BiAction action = this.action; - if (action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachMappingTask(this, b >>>= 1, true, - action).fork(); - } - Object v; - while ((v = advance()) != null) - action.apply((K)nextKey, (V)v); - tryComplete(); + final BiAction action; + if ((action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachMappingTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null; ) + action.apply(p.key, p.val); + propagateCompletion(); + } } } + @SuppressWarnings("serial") static final class ForEachTransformedKeyTask extends BulkTask { final Fun transformer; - final Action action; + final Action action; ForEachTransformedKeyTask - (ConcurrentHashMapV8 m, - Fun transformer, - Action action) { - super(m); - this.transformer = transformer; - this.action = action; - - } - ForEachTransformedKeyTask - (BulkTask p, int b, boolean split, - Fun transformer, - Action action) { - super(p, b, split); - this.transformer = transformer; - this.action = action; + (BulkTask p, int b, int i, int f, Node[] t, + Fun transformer, Action action) { + super(p, b, i, f, t); + this.transformer = transformer; this.action = action; } public final void compute() { - final Fun transformer = - this.transformer; - final Action action = this.action; - if (transformer == null || action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachTransformedKeyTask - (this, b >>>= 1, true, transformer, action).fork(); - } - U u; - while (advance() != null) { - if ((u = transformer.apply((K)nextKey)) != null) - action.apply(u); + final Fun transformer; + final Action action; + if ((transformer = this.transformer) != null && + (action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachTransformedKeyTask + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key)) != null) + action.apply(u); + } + propagateCompletion(); } - tryComplete(); } } + @SuppressWarnings("serial") static final class ForEachTransformedValueTask extends BulkTask { final Fun transformer; - final Action action; - ForEachTransformedValueTask - (ConcurrentHashMapV8 m, - Fun transformer, - Action action) { - super(m); - this.transformer = transformer; - this.action = action; - - } + final Action action; ForEachTransformedValueTask - (BulkTask p, int b, boolean split, - Fun transformer, - Action action) { - super(p, b, split); - this.transformer = transformer; - this.action = action; + (BulkTask p, int b, int i, int f, Node[] t, + Fun transformer, Action action) { + super(p, b, i, f, t); + this.transformer = transformer; this.action = action; } public final void compute() { - final Fun transformer = - this.transformer; - final Action action = this.action; - if (transformer == null || action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachTransformedValueTask - (this, b >>>= 1, true, transformer, action).fork(); - } - Object v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply((V)v)) != null) - action.apply(u); + final Fun transformer; + final Action action; + if ((transformer = this.transformer) != null && + (action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachTransformedValueTask + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.val)) != null) + action.apply(u); + } + propagateCompletion(); } - tryComplete(); } } + @SuppressWarnings("serial") static final class ForEachTransformedEntryTask extends BulkTask { final Fun, ? extends U> transformer; - final Action action; + final Action action; ForEachTransformedEntryTask - (ConcurrentHashMapV8 m, - Fun, ? extends U> transformer, - Action action) { - super(m); - this.transformer = transformer; - this.action = action; - - } - ForEachTransformedEntryTask - (BulkTask p, int b, boolean split, - Fun, ? extends U> transformer, - Action action) { - super(p, b, split); - this.transformer = transformer; - this.action = action; + (BulkTask p, int b, int i, int f, Node[] t, + Fun, ? extends U> transformer, Action action) { + super(p, b, i, f, t); + this.transformer = transformer; this.action = action; } public final void compute() { - final Fun, ? extends U> transformer = - this.transformer; - final Action action = this.action; - if (transformer == null || action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachTransformedEntryTask - (this, b >>>= 1, true, transformer, action).fork(); - } - Object v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null) - action.apply(u); + final Fun, ? extends U> transformer; + final Action action; + if ((transformer = this.transformer) != null && + (action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachTransformedEntryTask + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p)) != null) + action.apply(u); + } + propagateCompletion(); } - tryComplete(); } } + @SuppressWarnings("serial") static final class ForEachTransformedMappingTask extends BulkTask { final BiFun transformer; - final Action action; + final Action action; ForEachTransformedMappingTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, BiFun transformer, - Action action) { - super(m); - this.transformer = transformer; - this.action = action; - - } - ForEachTransformedMappingTask - (BulkTask p, int b, boolean split, - BiFun transformer, - Action action) { - super(p, b, split); - this.transformer = transformer; - this.action = action; + Action action) { + super(p, b, i, f, t); + this.transformer = transformer; this.action = action; } public final void compute() { - final BiFun transformer = - this.transformer; - final Action action = this.action; - if (transformer == null || action == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit) { - do {} while (!casPending(c = pending, c+1)); - new ForEachTransformedMappingTask - (this, b >>>= 1, true, transformer, action).fork(); - } - Object v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply((K)nextKey, (V)v)) != null) - action.apply(u); + final BiFun transformer; + final Action action; + if ((transformer = this.transformer) != null && + (action = this.action) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachTransformedMappingTask + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key, p.val)) != null) + action.apply(u); + } + propagateCompletion(); } - tryComplete(); } } + @SuppressWarnings("serial") static final class SearchKeysTask extends BulkTask { final Fun searchFunction; final AtomicReference result; SearchKeysTask - (ConcurrentHashMapV8 m, - Fun searchFunction, - AtomicReference result) { - super(m); - this.searchFunction = searchFunction; this.result = result; - } - SearchKeysTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, Fun searchFunction, AtomicReference result) { - super(p, b, split); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } + public final U getRawResult() { return result.get(); } public final void compute() { - AtomicReference result = this.result; - final Fun searchFunction = - this.searchFunction; - if (searchFunction == null || result == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit && result.get() == null) { - do {} while (!casPending(c = pending, c+1)); - new SearchKeysTask(this, b >>>= 1, true, - searchFunction, result).fork(); - } - U u; - while (result.get() == null && advance() != null) { - if ((u = searchFunction.apply((K)nextKey)) != null) { - result.compareAndSet(null, u); - break; + final Fun searchFunction; + final AtomicReference result; + if ((searchFunction = this.searchFunction) != null && + (result = this.result) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + if (result.get() != null) + return; + addToPendingCount(1); + new SearchKeysTask + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); + } + while (result.get() == null) { + U u; + Node p; + if ((p = advance()) == null) { + propagateCompletion(); + break; + } + if ((u = searchFunction.apply(p.key)) != null) { + if (result.compareAndSet(null, u)) + quietlyCompleteRoot(); + break; + } } } - tryComplete(); } - public final U getRawResult() { return result.get(); } } + @SuppressWarnings("serial") static final class SearchValuesTask extends BulkTask { final Fun searchFunction; final AtomicReference result; SearchValuesTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, Fun searchFunction, AtomicReference result) { - super(m); - this.searchFunction = searchFunction; this.result = result; - } - SearchValuesTask - (BulkTask p, int b, boolean split, - Fun searchFunction, - AtomicReference result) { - super(p, b, split); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } + public final U getRawResult() { return result.get(); } public final void compute() { - AtomicReference result = this.result; - final Fun searchFunction = - this.searchFunction; - if (searchFunction == null || result == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit && result.get() == null) { - do {} while (!casPending(c = pending, c+1)); - new SearchValuesTask(this, b >>>= 1, true, - searchFunction, result).fork(); - } - Object v; U u; - while (result.get() == null && (v = advance()) != null) { - if ((u = searchFunction.apply((V)v)) != null) { - result.compareAndSet(null, u); - break; + final Fun searchFunction; + final AtomicReference result; + if ((searchFunction = this.searchFunction) != null && + (result = this.result) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + if (result.get() != null) + return; + addToPendingCount(1); + new SearchValuesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); + } + while (result.get() == null) { + U u; + Node p; + if ((p = advance()) == null) { + propagateCompletion(); + break; + } + if ((u = searchFunction.apply(p.val)) != null) { + if (result.compareAndSet(null, u)) + quietlyCompleteRoot(); + break; + } } } - tryComplete(); } - public final U getRawResult() { return result.get(); } } + @SuppressWarnings("serial") static final class SearchEntriesTask extends BulkTask { final Fun, ? extends U> searchFunction; final AtomicReference result; SearchEntriesTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, Fun, ? extends U> searchFunction, AtomicReference result) { - super(m); - this.searchFunction = searchFunction; this.result = result; - } - SearchEntriesTask - (BulkTask p, int b, boolean split, - Fun, ? extends U> searchFunction, - AtomicReference result) { - super(p, b, split); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } + public final U getRawResult() { return result.get(); } public final void compute() { - AtomicReference result = this.result; - final Fun, ? extends U> searchFunction = - this.searchFunction; - if (searchFunction == null || result == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit && result.get() == null) { - do {} while (!casPending(c = pending, c+1)); - new SearchEntriesTask(this, b >>>= 1, true, - searchFunction, result).fork(); - } - Object v; U u; - while (result.get() == null && (v = advance()) != null) { - if ((u = searchFunction.apply(entryFor((K)nextKey, (V)v))) != null) { - result.compareAndSet(null, u); - break; + final Fun, ? extends U> searchFunction; + final AtomicReference result; + if ((searchFunction = this.searchFunction) != null && + (result = this.result) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + if (result.get() != null) + return; + addToPendingCount(1); + new SearchEntriesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); + } + while (result.get() == null) { + U u; + Node p; + if ((p = advance()) == null) { + propagateCompletion(); + break; + } + if ((u = searchFunction.apply(p)) != null) { + if (result.compareAndSet(null, u)) + quietlyCompleteRoot(); + return; + } } } - tryComplete(); } - public final U getRawResult() { return result.get(); } } + @SuppressWarnings("serial") static final class SearchMappingsTask extends BulkTask { final BiFun searchFunction; final AtomicReference result; SearchMappingsTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, BiFun searchFunction, AtomicReference result) { - super(m); - this.searchFunction = searchFunction; this.result = result; - } - SearchMappingsTask - (BulkTask p, int b, boolean split, - BiFun searchFunction, - AtomicReference result) { - super(p, b, split); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } + public final U getRawResult() { return result.get(); } public final void compute() { - AtomicReference result = this.result; - final BiFun searchFunction = - this.searchFunction; - if (searchFunction == null || result == null) - throw new Error(NullFunctionMessage); - int b = batch(), c; - while (b > 1 && baseIndex != baseLimit && result.get() == null) { - do {} while (!casPending(c = pending, c+1)); - new SearchMappingsTask(this, b >>>= 1, true, - searchFunction, result).fork(); - } - Object v; U u; - while (result.get() == null && (v = advance()) != null) { - if ((u = searchFunction.apply((K)nextKey, (V)v)) != null) { - result.compareAndSet(null, u); - break; + final BiFun searchFunction; + final AtomicReference result; + if ((searchFunction = this.searchFunction) != null && + (result = this.result) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + if (result.get() != null) + return; + addToPendingCount(1); + new SearchMappingsTask + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); + } + while (result.get() == null) { + U u; + Node p; + if ((p = advance()) == null) { + propagateCompletion(); + break; + } + if ((u = searchFunction.apply(p.key, p.val)) != null) { + if (result.compareAndSet(null, u)) + quietlyCompleteRoot(); + break; + } } } - tryComplete(); } - public final U getRawResult() { return result.get(); } } + @SuppressWarnings("serial") static final class ReduceKeysTask extends BulkTask { final BiFun reducer; K result; - ReduceKeysTask sibling; + ReduceKeysTask rights, nextRight; ReduceKeysTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + ReduceKeysTask nextRight, BiFun reducer) { - super(m); + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } - ReduceKeysTask - (BulkTask p, int b, boolean split, - BiFun reducer) { - super(p, b, split); - this.reducer = reducer; - } - + public final K getRawResult() { return result; } public final void compute() { - ReduceKeysTask t = this; - final BiFun reducer = - this.reducer; - if (reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - ReduceKeysTask rt = - new ReduceKeysTask - (t, b, true, reducer); - t = new ReduceKeysTask - (t, b, false, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - K r = null; - while (t.advance() != null) { - K u = (K)t.nextKey; - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; ReduceKeysTask s, p; K u; - if ((par = t.parent) == null || - !(par instanceof ReduceKeysTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (ReduceKeysTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) - r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; + final BiFun reducer; + if ((reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new ReduceKeysTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); + } + K r = null; + for (Node p; (p = advance()) != null; ) { + K u = p.key; + r = (r == null) ? u : u == null ? r : reducer.apply(r, u); + } + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") ReduceKeysTask + 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; + } } - else if (p.casPending(c, 0)) - break; } } - public final K getRawResult() { return result; } } + @SuppressWarnings("serial") static final class ReduceValuesTask extends BulkTask { final BiFun reducer; V result; - ReduceValuesTask sibling; - ReduceValuesTask - (ConcurrentHashMapV8 m, - BiFun reducer) { - super(m); - this.reducer = reducer; - } + ReduceValuesTask rights, nextRight; ReduceValuesTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + ReduceValuesTask nextRight, BiFun reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } - + public final V getRawResult() { return result; } public final void compute() { - ReduceValuesTask t = this; - final BiFun reducer = - this.reducer; - if (reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - ReduceValuesTask rt = - new ReduceValuesTask - (t, b, true, reducer); - t = new ReduceValuesTask - (t, b, false, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - V r = null; - Object v; - while ((v = t.advance()) != null) { - V u = (V)v; - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; ReduceValuesTask s, p; V u; - if ((par = t.parent) == null || - !(par instanceof ReduceValuesTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (ReduceValuesTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) - r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; + final BiFun reducer; + if ((reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new ReduceValuesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); + } + V r = null; + for (Node p; (p = advance()) != null; ) { + V v = p.val; + r = (r == null) ? v : reducer.apply(r, v); + } + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") ReduceValuesTask + 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; + } } - else if (p.casPending(c, 0)) - break; } } - public final V getRawResult() { return result; } } + @SuppressWarnings("serial") static final class ReduceEntriesTask extends BulkTask> { final BiFun, Map.Entry, ? extends Map.Entry> reducer; Map.Entry result; - ReduceEntriesTask sibling; + ReduceEntriesTask rights, nextRight; ReduceEntriesTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + ReduceEntriesTask nextRight, BiFun, Map.Entry, ? extends Map.Entry> reducer) { - super(m); - this.reducer = reducer; - } - ReduceEntriesTask - (BulkTask p, int b, boolean split, - BiFun, Map.Entry, ? extends Map.Entry> reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } - + public final Map.Entry getRawResult() { return result; } public final void compute() { - ReduceEntriesTask t = this; - final BiFun, Map.Entry, ? extends Map.Entry> reducer = - this.reducer; - if (reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - ReduceEntriesTask rt = - new ReduceEntriesTask - (t, b, true, reducer); - t = new ReduceEntriesTask - (t, b, false, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - Map.Entry r = null; - Object v; - while ((v = t.advance()) != null) { - Map.Entry u = entryFor((K)t.nextKey, (V)v); - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; ReduceEntriesTask s, p; - Map.Entry u; - if ((par = t.parent) == null || - !(par instanceof ReduceEntriesTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (ReduceEntriesTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) - r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; + final BiFun, Map.Entry, ? extends Map.Entry> reducer; + if ((reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new ReduceEntriesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); + } + Map.Entry r = null; + for (Node p; (p = advance()) != null; ) + r = (r == null) ? p : reducer.apply(r, p); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") ReduceEntriesTask + 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; + } } - else if (p.casPending(c, 0)) - break; } } - public final Map.Entry getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceKeysTask extends BulkTask { final Fun transformer; final BiFun reducer; U result; - MapReduceKeysTask sibling; - MapReduceKeysTask - (ConcurrentHashMapV8 m, - Fun transformer, - BiFun reducer) { - super(m); - this.transformer = transformer; - this.reducer = reducer; - } + MapReduceKeysTask rights, nextRight; MapReduceKeysTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceKeysTask nextRight, Fun transformer, BiFun reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } + public final U getRawResult() { return result; } public final void compute() { - MapReduceKeysTask t = this; - final Fun transformer = - this.transformer; - final BiFun reducer = - this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceKeysTask rt = - new MapReduceKeysTask - (t, b, true, transformer, reducer); - t = new MapReduceKeysTask - (t, b, false, transformer, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - U r = null, u; - while (t.advance() != null) { - if ((u = transformer.apply((K)t.nextKey)) != null) - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceKeysTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceKeysTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceKeysTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) + final Fun transformer; + final BiFun reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceKeysTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key)) != null) r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; } - else if (p.casPending(c, 0)) - break; + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") 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; + } + } } } - public final U getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceValuesTask extends BulkTask { final Fun transformer; final BiFun reducer; U result; - MapReduceValuesTask sibling; + MapReduceValuesTask rights, nextRight; MapReduceValuesTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceValuesTask nextRight, Fun transformer, BiFun reducer) { - super(m); - this.transformer = transformer; - this.reducer = reducer; - } - MapReduceValuesTask - (BulkTask p, int b, boolean split, - Fun transformer, - BiFun reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } + public final U getRawResult() { return result; } public final void compute() { - MapReduceValuesTask t = this; - final Fun transformer = - this.transformer; - final BiFun reducer = - this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceValuesTask rt = - new MapReduceValuesTask - (t, b, true, transformer, reducer); - t = new MapReduceValuesTask - (t, b, false, transformer, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - U r = null, u; - Object v; - while ((v = t.advance()) != null) { - if ((u = transformer.apply((V)v)) != null) - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceValuesTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceValuesTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceValuesTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) + final Fun transformer; + final BiFun reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceValuesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.val)) != null) r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; } - else if (p.casPending(c, 0)) - break; + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") 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; + } + } } } - public final U getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceEntriesTask extends BulkTask { final Fun, ? extends U> transformer; final BiFun reducer; U result; - MapReduceEntriesTask sibling; + MapReduceEntriesTask rights, nextRight; MapReduceEntriesTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceEntriesTask nextRight, Fun, ? extends U> transformer, BiFun reducer) { - super(m); - this.transformer = transformer; - this.reducer = reducer; - } - MapReduceEntriesTask - (BulkTask p, int b, boolean split, - Fun, ? extends U> transformer, - BiFun reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } + public final U getRawResult() { return result; } public final void compute() { - MapReduceEntriesTask t = this; - final Fun, ? extends U> transformer = - this.transformer; - final BiFun reducer = - this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceEntriesTask rt = - new MapReduceEntriesTask - (t, b, true, transformer, reducer); - t = new MapReduceEntriesTask - (t, b, false, transformer, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - U r = null, u; - Object v; - while ((v = t.advance()) != null) { - if ((u = transformer.apply(entryFor((K)t.nextKey, (V)v))) != null) - r = (r == null) ? u : reducer.apply(r, u); - } - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceEntriesTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceEntriesTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceEntriesTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) + final Fun, ? extends U> transformer; + final BiFun reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceEntriesTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p)) != null) r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; } - else if (p.casPending(c, 0)) - break; + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") 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; + } + } } } - public final U getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceMappingsTask extends BulkTask { final BiFun transformer; final BiFun reducer; U result; - MapReduceMappingsTask sibling; - MapReduceMappingsTask - (ConcurrentHashMapV8 m, - BiFun transformer, - BiFun reducer) { - super(m); - this.transformer = transformer; - this.reducer = reducer; - } + MapReduceMappingsTask rights, nextRight; MapReduceMappingsTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceMappingsTask nextRight, BiFun transformer, BiFun reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } + public final U getRawResult() { return result; } public final void compute() { - MapReduceMappingsTask t = this; - final BiFun transformer = - this.transformer; - final BiFun reducer = - this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceMappingsTask rt = - new MapReduceMappingsTask - (t, b, true, transformer, reducer); - t = new MapReduceMappingsTask - (t, b, false, transformer, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - U r = null, u; - Object v; - while ((v = t.advance()) != null) { - if ((u = transformer.apply((K)t.nextKey, (V)v)) != null) - r = (r == null) ? u : reducer.apply(r, u); - } - for (;;) { - int c; BulkTask par; MapReduceMappingsTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceMappingsTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceMappingsTask)par).pending) == 0) { - if ((s = t.sibling) != null && (u = s.result) != null) + final BiFun transformer; + final BiFun reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceMappingsTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key, p.val)) != null) r = (r == null) ? u : reducer.apply(r, u); - (t = p).result = r; } - else if (p.casPending(c, 0)) - break; + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") 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; + } + } } } - public final U getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask extends BulkTask { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; - MapReduceKeysToDoubleTask sibling; - MapReduceKeysToDoubleTask - (ConcurrentHashMapV8 m, - ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } + MapReduceKeysToDoubleTask rights, nextRight; MapReduceKeysToDoubleTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceKeysToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Double getRawResult() { return result; } public final void compute() { - MapReduceKeysToDoubleTask t = this; - final ObjectToDouble transformer = - this.transformer; - final DoubleByDoubleToDouble reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final double id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceKeysToDoubleTask rt = - new MapReduceKeysToDoubleTask - (t, b, true, transformer, id, reducer); - t = new MapReduceKeysToDoubleTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - double r = id; - while (t.advance() != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceKeysToDoubleTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceKeysToDoubleTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceKeysToDoubleTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToDouble transformer; + final DoubleByDoubleToDouble reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + double r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceKeysToDoubleTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceKeysToDoubleTask + t = (MapReduceKeysToDoubleTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Double getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask extends BulkTask { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; - MapReduceValuesToDoubleTask sibling; + MapReduceValuesToDoubleTask rights, nextRight; MapReduceValuesToDoubleTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceValuesToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceValuesToDoubleTask - (BulkTask p, int b, boolean split, - ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Double getRawResult() { return result; } public final void compute() { - MapReduceValuesToDoubleTask t = this; - final ObjectToDouble transformer = - this.transformer; - final DoubleByDoubleToDouble reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final double id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceValuesToDoubleTask rt = - new MapReduceValuesToDoubleTask - (t, b, true, transformer, id, reducer); - t = new MapReduceValuesToDoubleTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - double r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceValuesToDoubleTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceValuesToDoubleTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceValuesToDoubleTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToDouble transformer; + final DoubleByDoubleToDouble reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + double r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceValuesToDoubleTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceValuesToDoubleTask + t = (MapReduceValuesToDoubleTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Double getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask extends BulkTask { final ObjectToDouble> transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; - MapReduceEntriesToDoubleTask sibling; + MapReduceEntriesToDoubleTask rights, nextRight; MapReduceEntriesToDoubleTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceEntriesToDoubleTask nextRight, ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceEntriesToDoubleTask - (BulkTask p, int b, boolean split, - ObjectToDouble> transformer, - double basis, - DoubleByDoubleToDouble reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Double getRawResult() { return result; } public final void compute() { - MapReduceEntriesToDoubleTask t = this; - final ObjectToDouble> transformer = - this.transformer; - final DoubleByDoubleToDouble reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final double id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceEntriesToDoubleTask rt = - new MapReduceEntriesToDoubleTask - (t, b, true, transformer, id, reducer); - t = new MapReduceEntriesToDoubleTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - double r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)t.nextKey, (V)v))); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceEntriesToDoubleTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceEntriesToDoubleTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceEntriesToDoubleTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToDouble> transformer; + final DoubleByDoubleToDouble reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + double r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceEntriesToDoubleTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask + t = (MapReduceEntriesToDoubleTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Double getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask extends BulkTask { final ObjectByObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; - MapReduceMappingsToDoubleTask sibling; - MapReduceMappingsToDoubleTask - (ConcurrentHashMapV8 m, - ObjectByObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } + MapReduceMappingsToDoubleTask rights, nextRight; MapReduceMappingsToDoubleTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceMappingsToDoubleTask nextRight, ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Double getRawResult() { return result; } public final void compute() { - MapReduceMappingsToDoubleTask t = this; - final ObjectByObjectToDouble transformer = - this.transformer; - final DoubleByDoubleToDouble reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final double id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceMappingsToDoubleTask rt = - new MapReduceMappingsToDoubleTask - (t, b, true, transformer, id, reducer); - t = new MapReduceMappingsToDoubleTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - double r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey, (V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceMappingsToDoubleTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceMappingsToDoubleTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceMappingsToDoubleTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectByObjectToDouble transformer; + final DoubleByDoubleToDouble reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + double r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceMappingsToDoubleTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask + t = (MapReduceMappingsToDoubleTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Double getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceKeysToLongTask extends BulkTask { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; - MapReduceKeysToLongTask sibling; - MapReduceKeysToLongTask - (ConcurrentHashMapV8 m, - ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } + MapReduceKeysToLongTask rights, nextRight; MapReduceKeysToLongTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceKeysToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Long getRawResult() { return result; } public final void compute() { - MapReduceKeysToLongTask t = this; - final ObjectToLong transformer = - this.transformer; - final LongByLongToLong reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final long id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceKeysToLongTask rt = - new MapReduceKeysToLongTask - (t, b, true, transformer, id, reducer); - t = new MapReduceKeysToLongTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - long r = id; - while (t.advance() != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceKeysToLongTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceKeysToLongTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceKeysToLongTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToLong transformer; + final LongByLongToLong reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + long r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceKeysToLongTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceKeysToLongTask + t = (MapReduceKeysToLongTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Long getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceValuesToLongTask extends BulkTask { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; - MapReduceValuesToLongTask sibling; + MapReduceValuesToLongTask rights, nextRight; MapReduceValuesToLongTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceValuesToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceValuesToLongTask - (BulkTask p, int b, boolean split, - ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Long getRawResult() { return result; } public final void compute() { - MapReduceValuesToLongTask t = this; - final ObjectToLong transformer = - this.transformer; - final LongByLongToLong reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final long id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceValuesToLongTask rt = - new MapReduceValuesToLongTask - (t, b, true, transformer, id, reducer); - t = new MapReduceValuesToLongTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - long r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceValuesToLongTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceValuesToLongTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceValuesToLongTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToLong transformer; + final LongByLongToLong reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + long r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceValuesToLongTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceValuesToLongTask + t = (MapReduceValuesToLongTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Long getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask extends BulkTask { final ObjectToLong> transformer; final LongByLongToLong reducer; final long basis; long result; - MapReduceEntriesToLongTask sibling; + MapReduceEntriesToLongTask rights, nextRight; MapReduceEntriesToLongTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceEntriesToLongTask nextRight, ObjectToLong> transformer, long basis, LongByLongToLong reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceEntriesToLongTask - (BulkTask p, int b, boolean split, - ObjectToLong> transformer, - long basis, - LongByLongToLong reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Long getRawResult() { return result; } public final void compute() { - MapReduceEntriesToLongTask t = this; - final ObjectToLong> transformer = - this.transformer; - final LongByLongToLong reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final long id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceEntriesToLongTask rt = - new MapReduceEntriesToLongTask - (t, b, true, transformer, id, reducer); - t = new MapReduceEntriesToLongTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - long r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)t.nextKey, (V)v))); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceEntriesToLongTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceEntriesToLongTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceEntriesToLongTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToLong> transformer; + final LongByLongToLong reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + long r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceEntriesToLongTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceEntriesToLongTask + t = (MapReduceEntriesToLongTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Long getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask extends BulkTask { final ObjectByObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; - MapReduceMappingsToLongTask sibling; + MapReduceMappingsToLongTask rights, nextRight; MapReduceMappingsToLongTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceMappingsToLongTask nextRight, ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceMappingsToLongTask - (BulkTask p, int b, boolean split, - ObjectByObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Long getRawResult() { return result; } public final void compute() { - MapReduceMappingsToLongTask t = this; - final ObjectByObjectToLong transformer = - this.transformer; - final LongByLongToLong reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final long id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceMappingsToLongTask rt = - new MapReduceMappingsToLongTask - (t, b, true, transformer, id, reducer); - t = new MapReduceMappingsToLongTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - long r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey, (V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceMappingsToLongTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceMappingsToLongTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceMappingsToLongTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectByObjectToLong transformer; + final LongByLongToLong reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + long r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceMappingsToLongTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceMappingsToLongTask + t = (MapReduceMappingsToLongTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Long getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceKeysToIntTask extends BulkTask { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; - MapReduceKeysToIntTask sibling; + MapReduceKeysToIntTask rights, nextRight; MapReduceKeysToIntTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceKeysToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceKeysToIntTask - (BulkTask p, int b, boolean split, - ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Integer getRawResult() { return result; } public final void compute() { - MapReduceKeysToIntTask t = this; - final ObjectToInt transformer = - this.transformer; - final IntByIntToInt reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final int id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceKeysToIntTask rt = - new MapReduceKeysToIntTask - (t, b, true, transformer, id, reducer); - t = new MapReduceKeysToIntTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - int r = id; - while (t.advance() != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceKeysToIntTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceKeysToIntTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceKeysToIntTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToInt transformer; + final IntByIntToInt reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + int r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceKeysToIntTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceKeysToIntTask + t = (MapReduceKeysToIntTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Integer getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceValuesToIntTask extends BulkTask { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; - MapReduceValuesToIntTask sibling; - MapReduceValuesToIntTask - (ConcurrentHashMapV8 m, - ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } + MapReduceValuesToIntTask rights, nextRight; MapReduceValuesToIntTask - (BulkTask p, int b, boolean split, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceValuesToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Integer getRawResult() { return result; } public final void compute() { - MapReduceValuesToIntTask t = this; - final ObjectToInt transformer = - this.transformer; - final IntByIntToInt reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final int id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceValuesToIntTask rt = - new MapReduceValuesToIntTask - (t, b, true, transformer, id, reducer); - t = new MapReduceValuesToIntTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - int r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceValuesToIntTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceValuesToIntTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceValuesToIntTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToInt transformer; + final IntByIntToInt reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + int r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceValuesToIntTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceValuesToIntTask + t = (MapReduceValuesToIntTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Integer getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask extends BulkTask { final ObjectToInt> transformer; final IntByIntToInt reducer; final int basis; int result; - MapReduceEntriesToIntTask sibling; + MapReduceEntriesToIntTask rights, nextRight; MapReduceEntriesToIntTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceEntriesToIntTask nextRight, ObjectToInt> transformer, int basis, IntByIntToInt reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceEntriesToIntTask - (BulkTask p, int b, boolean split, - ObjectToInt> transformer, - int basis, - IntByIntToInt reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Integer getRawResult() { return result; } public final void compute() { - MapReduceEntriesToIntTask t = this; - final ObjectToInt> transformer = - this.transformer; - final IntByIntToInt reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final int id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceEntriesToIntTask rt = - new MapReduceEntriesToIntTask - (t, b, true, transformer, id, reducer); - t = new MapReduceEntriesToIntTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - int r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)t.nextKey, (V)v))); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceEntriesToIntTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceEntriesToIntTask)) { - t.quietlyComplete(); - break; - } - else if ((c = (p = (MapReduceEntriesToIntTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + final ObjectToInt> transformer; + final IntByIntToInt reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + int r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceEntriesToIntTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceEntriesToIntTask + t = (MapReduceEntriesToIntTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } } - else if (p.casPending(c, 0)) - break; } } - public final Integer getRawResult() { return result; } } + @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask extends BulkTask { final ObjectByObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; - MapReduceMappingsToIntTask sibling; + MapReduceMappingsToIntTask rights, nextRight; MapReduceMappingsToIntTask - (ConcurrentHashMapV8 m, + (BulkTask p, int b, int i, int f, Node[] t, + MapReduceMappingsToIntTask nextRight, ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(m); - this.transformer = transformer; - this.basis = basis; this.reducer = reducer; - } - MapReduceMappingsToIntTask - (BulkTask p, int b, boolean split, - ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - super(p, b, split); + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } + public final Integer getRawResult() { return result; } public final void compute() { - MapReduceMappingsToIntTask t = this; - final ObjectByObjectToInt transformer = - this.transformer; - final IntByIntToInt reducer = this.reducer; - if (transformer == null || reducer == null) - throw new Error(NullFunctionMessage); - final int id = this.basis; - int b = batch(); - while (b > 1 && t.baseIndex != t.baseLimit) { - b >>>= 1; - t.pending = 1; - MapReduceMappingsToIntTask rt = - new MapReduceMappingsToIntTask - (t, b, true, transformer, id, reducer); - t = new MapReduceMappingsToIntTask - (t, b, false, transformer, id, reducer); - t.sibling = rt; - rt.sibling = t; - rt.fork(); - } - int r = id; - Object v; - while ((v = t.advance()) != null) - r = reducer.apply(r, transformer.apply((K)t.nextKey, (V)v)); - t.result = r; - for (;;) { - int c; BulkTask par; MapReduceMappingsToIntTask s, p; - if ((par = t.parent) == null || - !(par instanceof MapReduceMappingsToIntTask)) { - t.quietlyComplete(); + final ObjectByObjectToInt transformer; + final IntByIntToInt reducer; + if ((transformer = this.transformer) != null && + (reducer = this.reducer) != null) { + int r = this.basis; + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + (rights = new MapReduceMappingsToIntTask + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); + result = r; + CountedCompleter c; + for (c = firstComplete(); c != null; c = c.nextComplete()) { + @SuppressWarnings("unchecked") MapReduceMappingsToIntTask + t = (MapReduceMappingsToIntTask)c, + s = t.rights; + while (s != null) { + t.result = reducer.apply(t.result, s.result); + s = t.rights = s.nextRight; + } + } + } + } + } + + /* ---------------- 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(); + + + 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 (cellsBusy == 0) { // Try to attach new Cell + CounterCell r = new CounterCell(x); // Optimistic create + if (cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean created = false; + try { // Recheck under lock + CounterCell[] rs; int m, j; + if ((rs = counterCells) != null && + (m = rs.length) > 0 && + rs[j = (m - 1) & h] == null) { + rs[j] = r; + created = true; + } + } finally { + cellsBusy = 0; + } + if (created) + break; + continue; // Slot is now non-empty + } + } + collide = false; + } + else if (!wasUncontended) // CAS already known to fail + wasUncontended = true; // Continue after rehash + else if (U.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 (cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + try { + if (counterCells == as) {// Expand table unless stale + CounterCell[] rs = new CounterCell[n << 1]; + for (int i = 0; i < n; ++i) + rs[i] = as[i]; + counterCells = rs; + } + } finally { + cellsBusy = 0; + } + collide = false; + continue; // Retry with expanded table } - else if ((c = (p = (MapReduceMappingsToIntTask)par).pending) == 0) { - if ((s = t.sibling) != null) - r = reducer.apply(r, s.result); - (t = p).result = r; + h ^= h << 13; // Rehash + h ^= h >>> 17; + h ^= h << 5; + } + else if (cellsBusy == 0 && counterCells == as && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean init = false; + try { // Initialize table + if (counterCells == as) { + CounterCell[] rs = new CounterCell[2]; + rs[h & 1] = new CounterCell(x); + counterCells = rs; + init = true; + } + } finally { + cellsBusy = 0; } - else if (p.casPending(c, 0)) + if (init) break; } + else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x)) + break; // Fall back on using base } - public final Integer getRawResult() { return result; } + hc.code = h; // Record index for next time } - // Unsafe mechanics - private static final sun.misc.Unsafe UNSAFE; - private static final long counterOffset; - private static final long sizeCtlOffset; + 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 CELLSBUSY; + private static final long CELLVALUE; private static final long ABASE; private static final int ASHIFT; static { - int ss; try { - UNSAFE = getUnsafe(); + U = getUnsafe(); Class k = ConcurrentHashMapV8.class; - counterOffset = UNSAFE.objectFieldOffset - (k.getDeclaredField("counter")); - sizeCtlOffset = UNSAFE.objectFieldOffset + SIZECTL = U.objectFieldOffset (k.getDeclaredField("sizeCtl")); - Class sc = Node[].class; - ABASE = UNSAFE.arrayBaseOffset(sc); - ss = UNSAFE.arrayIndexScale(sc); + TRANSFERINDEX = U.objectFieldOffset + (k.getDeclaredField("transferIndex")); + TRANSFERORIGIN = U.objectFieldOffset + (k.getDeclaredField("transferOrigin")); + BASECOUNT = U.objectFieldOffset + (k.getDeclaredField("baseCount")); + CELLSBUSY = U.objectFieldOffset + (k.getDeclaredField("cellsBusy")); + Class ck = CounterCell.class; + CELLVALUE = U.objectFieldOffset + (ck.getDeclaredField("value")); + Class ak = Node[].class; + ABASE = U.arrayBaseOffset(ak); + int scale = U.arrayIndexScale(ak); + 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); } - if ((ss & (ss-1)) != 0) - throw new Error("data type scale not a power of two"); - ASHIFT = 31 - Integer.numberOfLeadingZeros(ss); } /** @@ -6741,21 +6153,23 @@ public class ConcurrentHashMapV8 private static sun.misc.Unsafe getUnsafe() { try { return sun.misc.Unsafe.getUnsafe(); - } catch (SecurityException se) { - try { - return java.security.AccessController.doPrivileged - (new java.security - .PrivilegedExceptionAction() { - public sun.misc.Unsafe run() throws Exception { - java.lang.reflect.Field f = sun.misc - .Unsafe.class.getDeclaredField("theUnsafe"); - f.setAccessible(true); - return (sun.misc.Unsafe) f.get(null); - }}); - } catch (java.security.PrivilegedActionException e) { - throw new RuntimeException("Could not initialize intrinsics", - e.getCause()); - } + } 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()); } } }