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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.83 by jsr166, Mon Aug 22 03:42:10 2005 UTC vs.
Revision 1.142 by dl, Wed Oct 31 12:49:18 2012 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>	import java.util.concurrent.atomic.LongAdder;
9	>	import java.util.concurrent.ForkJoinPool;
10	>	import java.util.concurrent.ForkJoinTask;
11	>
12	>	import java.util.Comparator;
13	>	import java.util.Arrays;
14	>	import java.util.Map;
15	>	import java.util.Set;
16	>	import java.util.Collection;
17	>	import java.util.AbstractMap;
18	>	import java.util.AbstractSet;
19	>	import java.util.AbstractCollection;
20	>	import java.util.Hashtable;
21	>	import java.util.HashMap;
22	>	import java.util.Iterator;
23	>	import java.util.Enumeration;
24	>	import java.util.ConcurrentModificationException;
25	>	import java.util.NoSuchElementException;
26	>	import java.util.concurrent.ConcurrentMap;
27	>	import java.util.concurrent.ThreadLocalRandom;
28	>	import java.util.concurrent.locks.LockSupport;
29	>	import java.util.concurrent.locks.AbstractQueuedSynchronizer;
30	>	import java.util.concurrent.atomic.AtomicReference;
31	>
32		import java.io.Serializable;
11	–	import java.io.IOException;
12	–	import java.io.ObjectInputStream;
13	–	import java.io.ObjectOutputStream;
33
34		/**
35		* A hash table supporting full concurrency of retrievals and
36	<	* adjustable expected concurrency for updates. This class obeys the
36	>	* high expected concurrency for updates. This class obeys the
37		* same functional specification as {@link java.util.Hashtable}, and
38		* includes versions of methods corresponding to each method of
39	<	* <tt>Hashtable</tt>. However, even though all operations are
39	>	* {@code Hashtable}. However, even though all operations are
40		* thread-safe, retrieval operations do <em>not</em> entail locking,
41		* and there is <em>not</em> any support for locking the entire table
42		* in a way that prevents all access.  This class is fully
43	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
43	>	* interoperable with {@code Hashtable} in programs that rely on its
44		* thread safety but not on its synchronization details.
45		*
46	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
47	<	* block, so may overlap with update operations (including
48	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
49	<	* of the most recently <em>completed</em> update operations holding
50	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
51	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
52	<	* removal of only some entries.  Similarly, Iterators and
53	<	* Enumerations return elements reflecting the state of the hash table
54	<	* at some point at or since the creation of the iterator/enumeration.
55	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
56	<	* However, iterators are designed to be used by only one thread at a time.
57	<	*
58	<	* <p> The allowed concurrency among update operations is guided by
59	<	* the optional <tt>concurrencyLevel</tt> constructor argument
60	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
61	<	* table is internally partitioned to try to permit the indicated
62	<	* number of concurrent updates without contention. Because placement
63	<	* in hash tables is essentially random, the actual concurrency will
64	<	* vary.  Ideally, you should choose a value to accommodate as many
65	<	* threads as will ever concurrently modify the table. Using a
66	<	* significantly higher value than you need can waste space and time,
67	<	* and a significantly lower value can lead to thread contention. But
68	<	* overestimates and underestimates within an order of magnitude do
69	<	* not usually have much noticeable impact. A value of one is
70	<	* appropriate when it is known that only one thread will modify and
71	<	* all others will only read. Also, resizing this or any other kind of
72	<	* hash table is a relatively slow operation, so, when possible, it is
73	<	* a good idea to provide estimates of expected table sizes in
74	<	* constructors.
46	>	* <p> Retrieval operations (including {@code get}) generally do not
47	>	* block, so may overlap with update operations (including {@code put}
48	>	* and {@code remove}). Retrievals reflect the results of the most
49	>	* recently <em>completed</em> update operations holding upon their
50	>	* onset. (More formally, an update operation for a given key bears a
51	>	* <em>happens-before</em> relation with any (non-null) retrieval for
52	>	* that key reporting the updated value.)  For aggregate operations
53	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
54	>	* reflect insertion or removal of only some entries.  Similarly,
55	>	* Iterators and Enumerations return elements reflecting the state of
56	>	* the hash table at some point at or since the creation of the
57	>	* iterator/enumeration.  They do <em>not</em> throw {@link
58	>	* ConcurrentModificationException}.  However, iterators are designed
59	>	* to be used by only one thread at a time.  Bear in mind that the
60	>	* results of aggregate status methods including {@code size}, {@code
61	>	* isEmpty}, and {@code containsValue} are typically useful only when
62	>	* a map is not undergoing concurrent updates in other threads.
63	>	* Otherwise the results of these methods reflect transient states
64	>	* that may be adequate for monitoring or estimation purposes, but not
65	>	* for program control.
66	>	*
67	>	* <p> The table is dynamically expanded when there are too many
68	>	* collisions (i.e., keys that have distinct hash codes but fall into
69	>	* the same slot modulo the table size), with the expected average
70	>	* effect of maintaining roughly two bins per mapping (corresponding
71	>	* to a 0.75 load factor threshold for resizing). There may be much
72	>	* variance around this average as mappings are added and removed, but
73	>	* overall, this maintains a commonly accepted time/space tradeoff for
74	>	* hash tables.  However, resizing this or any other kind of hash
75	>	* table may be a relatively slow operation. When possible, it is a
76	>	* good idea to provide a size estimate as an optional {@code
77	>	* initialCapacity} constructor argument. An additional optional
78	>	* {@code loadFactor} constructor argument provides a further means of
79	>	* customizing initial table capacity by specifying the table density
80	>	* to be used in calculating the amount of space to allocate for the
81	>	* given number of elements.  Also, for compatibility with previous
82	>	* versions of this class, constructors may optionally specify an
83	>	* expected {@code concurrencyLevel} as an additional hint for
84	>	* internal sizing.  Note that using many keys with exactly the same
85	>	* {@code hashCode()} is a sure way to slow down performance of any
86	>	* hash table.
87	>	*
88	>	* <p> A {@link Set} projection of a ConcurrentHashMap may be created
89	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
90	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
91	>	* mapped values are (perhaps transiently) not used or all take the
92	>	* same mapping value.
93	>	*
94	>	* <p> A ConcurrentHashMap can be used as scalable frequency map (a
95	>	* form of histogram or multiset) by using {@link LongAdder} values
96	>	* and initializing via {@link #computeIfAbsent}. For example, to add
97	>	* a count to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you
98	>	* can use {@code freqs.computeIfAbsent(k -> new
99	>	* LongAdder()).increment();}
100		*
101		* <p>This class and its views and iterators implement all of the
102		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
103		* interfaces.
104		*
105		* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
106	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
106	>	* does <em>not</em> allow {@code null} to be used as a key or value.
107	>	*
108	>	* <p>ConcurrentHashMaps support parallel operations using the {@link
109	>	* ForkJoinPool#commonPool}. (Tasks that may be used in other contexts
110	>	* are available in class {@link ForkJoinTasks}). These operations are
111	>	* designed to be safely, and often sensibly, applied even with maps
112	>	* that are being concurrently updated by other threads; for example,
113	>	* when computing a snapshot summary of the values in a shared
114	>	* registry.  There are three kinds of operation, each with four
115	>	* forms, accepting functions with Keys, Values, Entries, and (Key,
116	>	* Value) arguments and/or return values. (The first three forms are
117	>	* also available via the {@link #keySet()}, {@link #values()} and
118	>	* {@link #entrySet()} views). Because the elements of a
119	>	* ConcurrentHashMap are not ordered in any particular way, and may be
120	>	* processed in different orders in different parallel executions, the
121	>	* correctness of supplied functions should not depend on any
122	>	* ordering, or on any other objects or values that may transiently
123	>	* change while computation is in progress; and except for forEach
124	>	* actions, should ideally be side-effect-free.
125	>	*
126	>	* <ul>
127	>	* <li> forEach: Perform a given action on each element.
128	>	* A variant form applies a given transformation on each element
129	>	* before performing the action.</li>
130	>	*
131	>	* <li> search: Return the first available non-null result of
132	>	* applying a given function on each element; skipping further
133	>	* search when a result is found.</li>
134	>	*
135	>	* <li> reduce: Accumulate each element.  The supplied reduction
136	>	* function cannot rely on ordering (more formally, it should be
137	>	* both associative and commutative).  There are five variants:
138	>	*
139	>	* <ul>
140	>	*
141	>	* <li> Plain reductions. (There is not a form of this method for
142	>	* (key, value) function arguments since there is no corresponding
143	>	* return type.)</li>
144	>	*
145	>	* <li> Mapped reductions that accumulate the results of a given
146	>	* function applied to each element.</li>
147	>	*
148	>	* <li> Reductions to scalar doubles, longs, and ints, using a
149	>	* given basis value.</li>
150	>	*
151	>	* </li>
152	>	* </ul>
153	>	* </ul>
154	>	*
155	>	* <p>The concurrency properties of bulk operations follow
156	>	* from those of ConcurrentHashMap: Any non-null result returned
157	>	* from {@code get(key)} and related access methods bears a
158	>	* happens-before relation with the associated insertion or
159	>	* update.  The result of any bulk operation reflects the
160	>	* composition of these per-element relations (but is not
161	>	* necessarily atomic with respect to the map as a whole unless it
162	>	* is somehow known to be quiescent).  Conversely, because keys
163	>	* and values in the map are never null, null serves as a reliable
164	>	* atomic indicator of the current lack of any result.  To
165	>	* maintain this property, null serves as an implicit basis for
166	>	* all non-scalar reduction operations. For the double, long, and
167	>	* int versions, the basis should be one that, when combined with
168	>	* any other value, returns that other value (more formally, it
169	>	* should be the identity element for the reduction). Most common
170	>	* reductions have these properties; for example, computing a sum
171	>	* with basis 0 or a minimum with basis MAX_VALUE.
172	>	*
173	>	* <p>Search and transformation functions provided as arguments
174	>	* should similarly return null to indicate the lack of any result
175	>	* (in which case it is not used). In the case of mapped
176	>	* reductions, this also enables transformations to serve as
177	>	* filters, returning null (or, in the case of primitive
178	>	* specializations, the identity basis) if the element should not
179	>	* be combined. You can create compound transformations and
180	>	* filterings by composing them yourself under this "null means
181	>	* there is nothing there now" rule before using them in search or
182	>	* reduce operations.
183	>	*
184	>	* <p>Methods accepting and/or returning Entry arguments maintain
185	>	* key-value associations. They may be useful for example when
186	>	* finding the key for the greatest value. Note that "plain" Entry
187	>	* arguments can be supplied using {@code new
188	>	* AbstractMap.SimpleEntry(k,v)}.
189	>	*
190	>	* <p> Bulk operations may complete abruptly, throwing an
191	>	* exception encountered in the application of a supplied
192	>	* function. Bear in mind when handling such exceptions that other
193	>	* concurrently executing functions could also have thrown
194	>	* exceptions, or would have done so if the first exception had
195	>	* not occurred.
196	>	*
197	>	* <p>Parallel speedups for bulk operations compared to sequential
198	>	* processing are common but not guaranteed.  Operations involving
199	>	* brief functions on small maps may execute more slowly than
200	>	* sequential loops if the underlying work to parallelize the
201	>	* computation is more expensive than the computation itself.
202	>	* Similarly, parallelization may not lead to much actual parallelism
203	>	* if all processors are busy performing unrelated tasks.
204	>	*
205	>	* <p> All arguments to all task methods must be non-null.
206	>	*
207	>	* <p><em>jsr166e note: During transition, this class
208	>	* uses nested functional interfaces with different names but the
209	>	* same forms as those expected for JDK8.<em>
210		*
211		* <p>This class is a member of the
212	<	* <a href="{@docRoot}/../guide/collections/index.html">
212	>	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
213		* Java Collections Framework</a>.
214		*
215		* @since 1.5
#	Line 70 | Line 217 | import java.io.ObjectOutputStream;
217		* @param <K> the type of keys maintained by this map
218		* @param <V> the type of mapped values
219		*/
220	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
221	<	implements ConcurrentMap<K, V>, Serializable {
220	>	public class ConcurrentHashMap<K, V>
221	>	implements ConcurrentMap<K, V>, Serializable {
222		private static final long serialVersionUID = 7249069246763182397L;
223
224	+	/**
225	+	* A partitionable iterator. A Spliterator can be traversed
226	+	* directly, but can also be partitioned (before traversal) by
227	+	* creating another Spliterator that covers a non-overlapping
228	+	* portion of the elements, and so may be amenable to parallel
229	+	* execution.
230	+	*
231	+	* <p> This interface exports a subset of expected JDK8
232	+	* functionality.
233	+	*
234	+	* <p>Sample usage: Here is one (of the several) ways to compute
235	+	* the sum of the values held in a map using the ForkJoin
236	+	* framework. As illustrated here, Spliterators are well suited to
237	+	* designs in which a task repeatedly splits off half its work
238	+	* into forked subtasks until small enough to process directly,
239	+	* and then joins these subtasks. Variants of this style can also
240	+	* be used in completion-based designs.
241	+	*
242	+	* <pre>
243	+	* {@code ConcurrentHashMap<String, Long> m = ...
244	+	* // split as if have 8 * parallelism, for load balance
245	+	* int n = m.size();
246	+	* int p = aForkJoinPool.getParallelism() * 8;
247	+	* int split = (n < p)? n : p;
248	+	* long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
249	+	* // ...
250	+	* static class SumValues extends RecursiveTask<Long> {
251	+	*   final Spliterator<Long> s;
252	+	*   final int split;             // split while > 1
253	+	*   final SumValues nextJoin;    // records forked subtasks to join
254	+	*   SumValues(Spliterator<Long> s, int depth, SumValues nextJoin) {
255	+	*     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
256	+	*   }
257	+	*   public Long compute() {
258	+	*     long sum = 0;
259	+	*     SumValues subtasks = null; // fork subtasks
260	+	*     for (int s = split >>> 1; s > 0; s >>>= 1)
261	+	*       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
262	+	*     while (s.hasNext())        // directly process remaining elements
263	+	*       sum += s.next();
264	+	*     for (SumValues t = subtasks; t != null; t = t.nextJoin)
265	+	*       sum += t.join();         // collect subtask results
266	+	*     return sum;
267	+	*   }
268	+	* }
269	+	* }</pre>
270	+	*/
271	+	public static interface Spliterator<T> extends Iterator<T> {
272	+	/**
273	+	* Returns a Spliterator covering approximately half of the
274	+	* elements, guaranteed not to overlap with those subsequently
275	+	* returned by this Spliterator.  After invoking this method,
276	+	* the current Spliterator will <em>not</em> produce any of
277	+	* the elements of the returned Spliterator, but the two
278	+	* Spliterators together will produce all of the elements that
279	+	* would have been produced by this Spliterator had this
280	+	* method not been called. The exact number of elements
281	+	* produced by the returned Spliterator is not guaranteed, and
282	+	* may be zero (i.e., with {@code hasNext()} reporting {@code
283	+	* false}) if this Spliterator cannot be further split.
284	+	*
285	+	* @return a Spliterator covering approximately half of the
286	+	* elements
287	+	* @throws IllegalStateException if this Spliterator has
288	+	* already commenced traversing elements
289	+	*/
290	+	Spliterator<T> split();
291	+	}
292	+
293	+
294		/*
295	<	* The basic strategy is to subdivide the table among Segments,
296	<	* each of which itself is a concurrently readable hash table.
295	>	* Overview:
296	>	*
297	>	* The primary design goal of this hash table is to maintain
298	>	* concurrent readability (typically method get(), but also
299	>	* iterators and related methods) while minimizing update
300	>	* contention. Secondary goals are to keep space consumption about
301	>	* the same or better than java.util.HashMap, and to support high
302	>	* initial insertion rates on an empty table by many threads.
303	>	*
304	>	* Each key-value mapping is held in a Node.  Because Node fields
305	>	* can contain special values, they are defined using plain Object
306	>	* types. Similarly in turn, all internal methods that use them
307	>	* work off Object types. And similarly, so do the internal
308	>	* methods of auxiliary iterator and view classes.  All public
309	>	* generic typed methods relay in/out of these internal methods,
310	>	* supplying null-checks and casts as needed. This also allows
311	>	* many of the public methods to be factored into a smaller number
312	>	* of internal methods (although sadly not so for the five
313	>	* variants of put-related operations). The validation-based
314	>	* approach explained below leads to a lot of code sprawl because
315	>	* retry-control precludes factoring into smaller methods.
316	>	*
317	>	* The table is lazily initialized to a power-of-two size upon the
318	>	* first insertion.  Each bin in the table normally contains a
319	>	* list of Nodes (most often, the list has only zero or one Node).
320	>	* Table accesses require volatile/atomic reads, writes, and
321	>	* CASes.  Because there is no other way to arrange this without
322	>	* adding further indirections, we use intrinsics
323	>	* (sun.misc.Unsafe) operations.  The lists of nodes within bins
324	>	* are always accurately traversable under volatile reads, so long
325	>	* as lookups check hash code and non-nullness of value before
326	>	* checking key equality.
327	>	*
328	>	* We use the top two bits of Node hash fields for control
329	>	* purposes -- they are available anyway because of addressing
330	>	* constraints.  As explained further below, these top bits are
331	>	* used as follows:
332	>	*  00 - Normal
333	>	*  01 - Locked
334	>	*  11 - Locked and may have a thread waiting for lock
335	>	*  10 - Node is a forwarding node
336	>	*
337	>	* The lower 30 bits of each Node's hash field contain a
338	>	* transformation of the key's hash code, except for forwarding
339	>	* nodes, for which the lower bits are zero (and so always have
340	>	* hash field == MOVED).
341	>	*
342	>	* Insertion (via put or its variants) of the first node in an
343	>	* empty bin is performed by just CASing it to the bin.  This is
344	>	* by far the most common case for put operations under most
345	>	* key/hash distributions.  Other update operations (insert,
346	>	* delete, and replace) require locks.  We do not want to waste
347	>	* the space required to associate a distinct lock object with
348	>	* each bin, so instead use the first node of a bin list itself as
349	>	* a lock. Blocking support for these locks relies on the builtin
350	>	* "synchronized" monitors.  However, we also need a tryLock
351	>	* construction, so we overlay these by using bits of the Node
352	>	* hash field for lock control (see above), and so normally use
353	>	* builtin monitors only for blocking and signalling using
354	>	* wait/notifyAll constructions. See Node.tryAwaitLock.
355	>	*
356	>	* Using the first node of a list as a lock does not by itself
357	>	* suffice though: When a node is locked, any update must first
358	>	* validate that it is still the first node after locking it, and
359	>	* retry if not. Because new nodes are always appended to lists,
360	>	* once a node is first in a bin, it remains first until deleted
361	>	* or the bin becomes invalidated (upon resizing).  However,
362	>	* operations that only conditionally update may inspect nodes
363	>	* until the point of update. This is a converse of sorts to the
364	>	* lazy locking technique described by Herlihy & Shavit.
365	>	*
366	>	* The main disadvantage of per-bin locks is that other update
367	>	* operations on other nodes in a bin list protected by the same
368	>	* lock can stall, for example when user equals() or mapping
369	>	* functions take a long time.  However, statistically, under
370	>	* random hash codes, this is not a common problem.  Ideally, the
371	>	* frequency of nodes in bins follows a Poisson distribution
372	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
373	>	* parameter of about 0.5 on average, given the resizing threshold
374	>	* of 0.75, although with a large variance because of resizing
375	>	* granularity. Ignoring variance, the expected occurrences of
376	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
377	>	* first values are:
378	>	*
379	>	* 0:    0.60653066
380	>	* 1:    0.30326533
381	>	* 2:    0.07581633
382	>	* 3:    0.01263606
383	>	* 4:    0.00157952
384	>	* 5:    0.00015795
385	>	* 6:    0.00001316
386	>	* 7:    0.00000094
387	>	* 8:    0.00000006
388	>	* more: less than 1 in ten million
389	>	*
390	>	* Lock contention probability for two threads accessing distinct
391	>	* elements is roughly 1 / (8 * #elements) under random hashes.
392	>	*
393	>	* Actual hash code distributions encountered in practice
394	>	* sometimes deviate significantly from uniform randomness.  This
395	>	* includes the case when N > (1<<30), so some keys MUST collide.
396	>	* Similarly for dumb or hostile usages in which multiple keys are
397	>	* designed to have identical hash codes. Also, although we guard
398	>	* against the worst effects of this (see method spread), sets of
399	>	* hashes may differ only in bits that do not impact their bin
400	>	* index for a given power-of-two mask.  So we use a secondary
401	>	* strategy that applies when the number of nodes in a bin exceeds
402	>	* a threshold, and at least one of the keys implements
403	>	* Comparable.  These TreeBins use a balanced tree to hold nodes
404	>	* (a specialized form of red-black trees), bounding search time
405	>	* to O(log N).  Each search step in a TreeBin is around twice as
406	>	* slow as in a regular list, but given that N cannot exceed
407	>	* (1<<64) (before running out of addresses) this bounds search
408	>	* steps, lock hold times, etc, to reasonable constants (roughly
409	>	* 100 nodes inspected per operation worst case) so long as keys
410	>	* are Comparable (which is very common -- String, Long, etc).
411	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
412	>	* traversal pointers as regular nodes, so can be traversed in
413	>	* iterators in the same way.
414	>	*
415	>	* The table is resized when occupancy exceeds a percentage
416	>	* threshold (nominally, 0.75, but see below).  Only a single
417	>	* thread performs the resize (using field "sizeCtl", to arrange
418	>	* exclusion), but the table otherwise remains usable for reads
419	>	* and updates. Resizing proceeds by transferring bins, one by
420	>	* one, from the table to the next table.  Because we are using
421	>	* power-of-two expansion, the elements from each bin must either
422	>	* stay at same index, or move with a power of two offset. We
423	>	* eliminate unnecessary node creation by catching cases where old
424	>	* nodes can be reused because their next fields won't change.  On
425	>	* average, only about one-sixth of them need cloning when a table
426	>	* doubles. The nodes they replace will be garbage collectable as
427	>	* soon as they are no longer referenced by any reader thread that
428	>	* may be in the midst of concurrently traversing table.  Upon
429	>	* transfer, the old table bin contains only a special forwarding
430	>	* node (with hash field "MOVED") that contains the next table as
431	>	* its key. On encountering a forwarding node, access and update
432	>	* operations restart, using the new table.
433	>	*
434	>	* Each bin transfer requires its bin lock. However, unlike other
435	>	* cases, a transfer can skip a bin if it fails to acquire its
436	>	* lock, and revisit it later (unless it is a TreeBin). Method
437	>	* rebuild maintains a buffer of TRANSFER_BUFFER_SIZE bins that
438	>	* have been skipped because of failure to acquire a lock, and
439	>	* blocks only if none are available (i.e., only very rarely).
440	>	* The transfer operation must also ensure that all accessible
441	>	* bins in both the old and new table are usable by any traversal.
442	>	* When there are no lock acquisition failures, this is arranged
443	>	* simply by proceeding from the last bin (table.length - 1) up
444	>	* towards the first.  Upon seeing a forwarding node, traversals
445	>	* (see class Iter) arrange to move to the new table
446	>	* without revisiting nodes.  However, when any node is skipped
447	>	* during a transfer, all earlier table bins may have become
448	>	* visible, so are initialized with a reverse-forwarding node back
449	>	* to the old table until the new ones are established. (This
450	>	* sometimes requires transiently locking a forwarding node, which
451	>	* is possible under the above encoding.) These more expensive
452	>	* mechanics trigger only when necessary.
453	>	*
454	>	* The traversal scheme also applies to partial traversals of
455	>	* ranges of bins (via an alternate Traverser constructor)
456	>	* to support partitioned aggregate operations.  Also, read-only
457	>	* operations give up if ever forwarded to a null table, which
458	>	* provides support for shutdown-style clearing, which is also not
459	>	* currently implemented.
460	>	*
461	>	* Lazy table initialization minimizes footprint until first use,
462	>	* and also avoids resizings when the first operation is from a
463	>	* putAll, constructor with map argument, or deserialization.
464	>	* These cases attempt to override the initial capacity settings,
465	>	* but harmlessly fail to take effect in cases of races.
466	>	*
467	>	* The element count is maintained using a LongAdder, which avoids
468	>	* contention on updates but can encounter cache thrashing if read
469	>	* too frequently during concurrent access. To avoid reading so
470	>	* often, resizing is attempted either when a bin lock is
471	>	* contended, or upon adding to a bin already holding two or more
472	>	* nodes (checked before adding in the xIfAbsent methods, after
473	>	* adding in others). Under uniform hash distributions, the
474	>	* probability of this occurring at threshold is around 13%,
475	>	* meaning that only about 1 in 8 puts check threshold (and after
476	>	* resizing, many fewer do so). But this approximation has high
477	>	* variance for small table sizes, so we check on any collision
478	>	* for sizes <= 64. The bulk putAll operation further reduces
479	>	* contention by only committing count updates upon these size
480	>	* checks.
481	>	*
482	>	* Maintaining API and serialization compatibility with previous
483	>	* versions of this class introduces several oddities. Mainly: We
484	>	* leave untouched but unused constructor arguments refering to
485	>	* concurrencyLevel. We accept a loadFactor constructor argument,
486	>	* but apply it only to initial table capacity (which is the only
487	>	* time that we can guarantee to honor it.) We also declare an
488	>	* unused "Segment" class that is instantiated in minimal form
489	>	* only when serializing.
490		*/
491
492		/* ---------------- Constants -------------- */
493
494		/**
495	<	* The default initial capacity for this table,
496	<	* used when not otherwise specified in a constructor.
495	>	* The largest possible table capacity.  This value must be
496	>	* exactly 1<<30 to stay within Java array allocation and indexing
497	>	* bounds for power of two table sizes, and is further required
498	>	* because the top two bits of 32bit hash fields are used for
499	>	* control purposes.
500	>	*/
501	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
502	>
503	>	/**
504	>	* The default initial table capacity.  Must be a power of 2
505	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
506		*/
507	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
507	>	private static final int DEFAULT_CAPACITY = 16;
508
509		/**
510	<	* The default load factor for this table, used when not
511	<	* otherwise specified in a constructor.
510	>	* The largest possible (non-power of two) array size.
511	>	* Needed by toArray and related methods.
512		*/
513	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
513	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
514
515		/**
516	<	* The default concurrency level for this table, used when not
517	<	* otherwise specified in a constructor.
516	>	* The default concurrency level for this table. Unused but
517	>	* defined for compatibility with previous versions of this class.
518		*/
519	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
519	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
520
521		/**
522	<	* The maximum capacity, used if a higher value is implicitly
523	<	* specified by either of the constructors with arguments.  MUST
524	<	* be a power of two <= 1<<30 to ensure that entries are indexable
525	<	* using ints.
522	>	* The load factor for this table. Overrides of this value in
523	>	* constructors affect only the initial table capacity.  The
524	>	* actual floating point value isn't normally used -- it is
525	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
526	>	* the associated resizing threshold.
527		*/
528	<	static final int MAXIMUM_CAPACITY = 1 << 30;
528	>	private static final float LOAD_FACTOR = 0.75f;
529
530		/**
531	<	* The maximum number of segments to allow; used to bound
532	<	* constructor arguments.
531	>	* The buffer size for skipped bins during transfers. The
532	>	* value is arbitrary but should be large enough to avoid
533	>	* most locking stalls during resizes.
534		*/
535	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
535	>	private static final int TRANSFER_BUFFER_SIZE = 32;
536
537		/**
538	<	* Number of unsynchronized retries in size and containsValue
539	<	* methods before resorting to locking. This is used to avoid
540	<	* unbounded retries if tables undergo continuous modification
541	<	* which would make it impossible to obtain an accurate result.
538	>	* The bin count threshold for using a tree rather than list for a
539	>	* bin.  The value reflects the approximate break-even point for
540	>	* using tree-based operations.
541	>	*/
542	>	private static final int TREE_THRESHOLD = 8;
543	>
544	>	/*
545	>	* Encodings for special uses of Node hash fields. See above for
546	>	* explanation.
547		*/
548	<	static final int RETRIES_BEFORE_LOCK = 2;
548	>	static final int MOVED     = 0x80000000; // hash field for forwarding nodes
549	>	static final int LOCKED    = 0x40000000; // set/tested only as a bit
550	>	static final int WAITING   = 0xc0000000; // both bits set/tested together
551	>	static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash
552
553		/* ---------------- Fields -------------- */
554
555		/**
556	<	* Mask value for indexing into segments. The upper bits of a
557	<	* key's hash code are used to choose the segment.
556	>	* The array of bins. Lazily initialized upon first insertion.
557	>	* Size is always a power of two. Accessed directly by iterators.
558		*/
559	<	final int segmentMask;
559	>	transient volatile Node[] table;
560
561		/**
562	<	* Shift value for indexing within segments.
562	>	* The counter maintaining number of elements.
563		*/
564	<	final int segmentShift;
564	>	private transient final LongAdder counter;
565
566		/**
567	<	* The segments, each of which is a specialized hash table
568	<	*/
569	<	final Segment<K,V>[] segments;
567	>	* Table initialization and resizing control.  When negative, the
568	>	* table is being initialized or resized. Otherwise, when table is
569	>	* null, holds the initial table size to use upon creation, or 0
570	>	* for default. After initialization, holds the next element count
571	>	* value upon which to resize the table.
572	>	*/
573	>	private transient volatile int sizeCtl;
574	>
575	>	// views
576	>	private transient KeySetView<K,V> keySet;
577	>	private transient ValuesView<K,V> values;
578	>	private transient EntrySetView<K,V> entrySet;
579
580	<	transient Set<K> keySet;
581	<	transient Set<Map.Entry<K,V>> entrySet;
144	<	transient Collection<V> values;
580	>	/** For serialization compatibility. Null unless serialized; see below */
581	>	private Segment<K,V>[] segments;
582
583	<	/* ---------------- Small Utilities -------------- */
583	>	/* ---------------- Table element access -------------- */
584
585	<	/**
586	<	* Returns a hash code for non-null Object x.
587	<	* Uses the same hash code spreader as most other java.util hash tables.
588	<	* @param x the object serving as a key
589	<	* @return the hash code
585	>	/*
586	>	* Volatile access methods are used for table elements as well as
587	>	* elements of in-progress next table while resizing.  Uses are
588	>	* null checked by callers, and implicitly bounds-checked, relying
589	>	* on the invariants that tab arrays have non-zero size, and all
590	>	* indices are masked with (tab.length - 1) which is never
591	>	* negative and always less than length. Note that, to be correct
592	>	* wrt arbitrary concurrency errors by users, bounds checks must
593	>	* operate on local variables, which accounts for some odd-looking
594	>	* inline assignments below.
595		*/
596	<	static int hash(Object x) {
597	<	int h = x.hashCode();
598	<	h += ~(h << 9);
157	<	h ^=  (h >>> 14);
158	<	h +=  (h << 4);
159	<	h ^=  (h >>> 10);
160	<	return h;
596	>
597	>	static final Node tabAt(Node[] tab, int i) { // used by Iter
598	>	return (Node)UNSAFE.getObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE);
599		}
600
601	<	/**
602	<	* Returns the segment that should be used for key with given hash
603	<	* @param hash the hash code for the key
604	<	* @return the segment
605	<	*/
606	<	final Segment<K,V> segmentFor(int hash) {
169	<	return segments[(hash >>> segmentShift) & segmentMask];
601	>	private static final boolean casTabAt(Node[] tab, int i, Node c, Node v) {
602	>	return UNSAFE.compareAndSwapObject(tab, ((long)i<<ASHIFT)+ABASE, c, v);
603	>	}
604	>
605	>	private static final void setTabAt(Node[] tab, int i, Node v) {
606	>	UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v);
607		}
608
609	<	/* ---------------- Inner Classes -------------- */
609	>	/* ---------------- Nodes -------------- */
610
611		/**
612	<	* ConcurrentHashMap list entry. Note that this is never exported
613	<	* out as a user-visible Map.Entry.
614	<	*
615	<	* Because the value field is volatile, not final, it is legal wrt
616	<	* the Java Memory Model for an unsynchronized reader to see null
617	<	* instead of initial value when read via a data race.  Although a
618	<	* reordering leading to this is not likely to ever actually
619	<	* occur, the Segment.readValueUnderLock method is used as a
620	<	* backup in case a null (pre-initialized) value is ever seen in
621	<	* an unsynchronized access method.
622	<	*/
623	<	static final class HashEntry<K,V> {
624	<	final K key;
625	<	final int hash;
189	<	volatile V value;
190	<	final HashEntry<K,V> next;
612	>	* Key-value entry. Note that this is never exported out as a
613	>	* user-visible Map.Entry (see MapEntry below). Nodes with a hash
614	>	* field of MOVED are special, and do not contain user keys or
615	>	* values.  Otherwise, keys are never null, and null val fields
616	>	* indicate that a node is in the process of being deleted or
617	>	* created. For purposes of read-only access, a key may be read
618	>	* before a val, but can only be used after checking val to be
619	>	* non-null.
620	>	*/
621	>	static class Node {
622	>	volatile int hash;
623	>	final Object key;
624	>	volatile Object val;
625	>	volatile Node next;
626
627	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
193	<	this.key = key;
627	>	Node(int hash, Object key, Object val, Node next) {
628		this.hash = hash;
629	+	this.key = key;
630	+	this.val = val;
631		this.next = next;
196	–	this.value = value;
632		}
633
634	<	@SuppressWarnings("unchecked")
635	<	static final <K,V> HashEntry<K,V>[] newArray(int i) {
636	<	return new HashEntry[i];
637	<	}
203	<	}
204	<
205	<	/**
206	<	* Segments are specialized versions of hash tables.  This
207	<	* subclasses from ReentrantLock opportunistically, just to
208	<	* simplify some locking and avoid separate construction.
209	<	*/
210	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
211	<	/*
212	<	* Segments maintain a table of entry lists that are ALWAYS
213	<	* kept in a consistent state, so can be read without locking.
214	<	* Next fields of nodes are immutable (final).  All list
215	<	* additions are performed at the front of each bin. This
216	<	* makes it easy to check changes, and also fast to traverse.
217	<	* When nodes would otherwise be changed, new nodes are
218	<	* created to replace them. This works well for hash tables
219	<	* since the bin lists tend to be short. (The average length
220	<	* is less than two for the default load factor threshold.)
221	<	*
222	<	* Read operations can thus proceed without locking, but rely
223	<	* on selected uses of volatiles to ensure that completed
224	<	* write operations performed by other threads are
225	<	* noticed. For most purposes, the "count" field, tracking the
226	<	* number of elements, serves as that volatile variable
227	<	* ensuring visibility.  This is convenient because this field
228	<	* needs to be read in many read operations anyway:
229	<	*
230	<	*   - All (unsynchronized) read operations must first read the
231	<	*     "count" field, and should not look at table entries if
232	<	*     it is 0.
233	<	*
234	<	*   - All (synchronized) write operations should write to
235	<	*     the "count" field after structurally changing any bin.
236	<	*     The operations must not take any action that could even
237	<	*     momentarily cause a concurrent read operation to see
238	<	*     inconsistent data. This is made easier by the nature of
239	<	*     the read operations in Map. For example, no operation
240	<	*     can reveal that the table has grown but the threshold
241	<	*     has not yet been updated, so there are no atomicity
242	<	*     requirements for this with respect to reads.
243	<	*
244	<	* As a guide, all critical volatile reads and writes to the
245	<	* count field are marked in code comments.
246	<	*/
634	>	/** CompareAndSet the hash field */
635	>	final boolean casHash(int cmp, int val) {
636	>	return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val);
637	>	}
638
639	<	private static final long serialVersionUID = 2249069246763182397L;
639	>	/** The number of spins before blocking for a lock */
640	>	static final int MAX_SPINS =
641	>	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
642
643		/**
644	<	* The number of elements in this segment's region.
644	>	* Spins a while if LOCKED bit set and this node is the first
645	>	* of its bin, and then sets WAITING bits on hash field and
646	>	* blocks (once) if they are still set.  It is OK for this
647	>	* method to return even if lock is not available upon exit,
648	>	* which enables these simple single-wait mechanics.
649	>	*
650	>	* The corresponding signalling operation is performed within
651	>	* callers: Upon detecting that WAITING has been set when
652	>	* unlocking lock (via a failed CAS from non-waiting LOCKED
653	>	* state), unlockers acquire the sync lock and perform a
654	>	* notifyAll.
655	>	*
656	>	* The initial sanity check on tab and bounds is not currently
657	>	* necessary in the only usages of this method, but enables
658	>	* use in other future contexts.
659		*/
660	<	transient volatile int count;
660	>	final void tryAwaitLock(Node[] tab, int i) {
661	>	if (tab != null && i >= 0 && i < tab.length) { // sanity check
662	>	int r = ThreadLocalRandom.current().nextInt(); // randomize spins
663	>	int spins = MAX_SPINS, h;
664	>	while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) {
665	>	if (spins >= 0) {
666	>	r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
667	>	if (r >= 0 && --spins == 0)
668	>	Thread.yield();  // yield before block
669	>	}
670	>	else if (casHash(h, h | WAITING)) {
671	>	synchronized (this) {
672	>	if (tabAt(tab, i) == this &&
673	>	(hash & WAITING) == WAITING) {
674	>	try {
675	>	wait();
676	>	} catch (InterruptedException ie) {
677	>	try {
678	>	Thread.currentThread().interrupt();
679	>	} catch (SecurityException ignore) {
680	>	}
681	>	}
682	>	}
683	>	else
684	>	notifyAll(); // possibly won race vs signaller
685	>	}
686	>	break;
687	>	}
688	>	}
689	>	}
690	>	}
691
692	<	/**
693	<	* Number of updates that alter the size of the table. This is
694	<	* used during bulk-read methods to make sure they see a
258	<	* consistent snapshot: If modCounts change during a traversal
259	<	* of segments computing size or checking containsValue, then
260	<	* we might have an inconsistent view of state so (usually)
261	<	* must retry.
262	<	*/
263	<	transient int modCount;
692	>	// Unsafe mechanics for casHash
693	>	private static final sun.misc.Unsafe UNSAFE;
694	>	private static final long hashOffset;
695
696	<	/**
697	<	* The table is rehashed when its size exceeds this threshold.
698	<	* (The value of this field is always <tt>(int)(capacity *
699	<	* loadFactor)</tt>.)
700	<	*/
701	<	transient int threshold;
696	>	static {
697	>	try {
698	>	UNSAFE = sun.misc.Unsafe.getUnsafe();
699	>	Class<?> k = Node.class;
700	>	hashOffset = UNSAFE.objectFieldOffset
701	>	(k.getDeclaredField("hash"));
702	>	} catch (Exception e) {
703	>	throw new Error(e);
704	>	}
705	>	}
706	>	}
707
708	<	/**
273	<	* The per-segment table.
274	<	*/
275	<	transient volatile HashEntry<K,V>[] table;
708	>	/* ---------------- TreeBins -------------- */
709
710	<	/**
711	<	* The load factor for the hash table.  Even though this value
712	<	* is same for all segments, it is replicated to avoid needing
713	<	* links to outer object.
714	<	* @serial
715	<	*/
716	<	final float loadFactor;
710	>	/**
711	>	* Nodes for use in TreeBins
712	>	*/
713	>	static final class TreeNode extends Node {
714	>	TreeNode parent;  // red-black tree links
715	>	TreeNode left;
716	>	TreeNode right;
717	>	TreeNode prev;    // needed to unlink next upon deletion
718	>	boolean red;
719	>
720	>	TreeNode(int hash, Object key, Object val, Node next, TreeNode parent) {
721	>	super(hash, key, val, next);
722	>	this.parent = parent;
723	>	}
724	>	}
725
726	<	Segment(int initialCapacity, float lf) {
727	<	loadFactor = lf;
728	<	setTable(HashEntry.<K,V>newArray(initialCapacity));
726	>	/**
727	>	* A specialized form of red-black tree for use in bins
728	>	* whose size exceeds a threshold.
729	>	*
730	>	* TreeBins use a special form of comparison for search and
731	>	* related operations (which is the main reason we cannot use
732	>	* existing collections such as TreeMaps). TreeBins contain
733	>	* Comparable elements, but may contain others, as well as
734	>	* elements that are Comparable but not necessarily Comparable<T>
735	>	* for the same T, so we cannot invoke compareTo among them. To
736	>	* handle this, the tree is ordered primarily by hash value, then
737	>	* by getClass().getName() order, and then by Comparator order
738	>	* among elements of the same class.  On lookup at a node, if
739	>	* elements are not comparable or compare as 0, both left and
740	>	* right children may need to be searched in the case of tied hash
741	>	* values. (This corresponds to the full list search that would be
742	>	* necessary if all elements were non-Comparable and had tied
743	>	* hashes.)  The red-black balancing code is updated from
744	>	* pre-jdk-collections
745	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
746	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
747	>	* Algorithms" (CLR).
748	>	*
749	>	* TreeBins also maintain a separate locking discipline than
750	>	* regular bins. Because they are forwarded via special MOVED
751	>	* nodes at bin heads (which can never change once established),
752	>	* we cannot use those nodes as locks. Instead, TreeBin
753	>	* extends AbstractQueuedSynchronizer to support a simple form of
754	>	* read-write lock. For update operations and table validation,
755	>	* the exclusive form of lock behaves in the same way as bin-head
756	>	* locks. However, lookups use shared read-lock mechanics to allow
757	>	* multiple readers in the absence of writers.  Additionally,
758	>	* these lookups do not ever block: While the lock is not
759	>	* available, they proceed along the slow traversal path (via
760	>	* next-pointers) until the lock becomes available or the list is
761	>	* exhausted, whichever comes first. (These cases are not fast,
762	>	* but maximize aggregate expected throughput.)  The AQS mechanics
763	>	* for doing this are straightforward.  The lock state is held as
764	>	* AQS getState().  Read counts are negative; the write count (1)
765	>	* is positive.  There are no signalling preferences among readers
766	>	* and writers. Since we don't need to export full Lock API, we
767	>	* just override the minimal AQS methods and use them directly.
768	>	*/
769	>	static final class TreeBin extends AbstractQueuedSynchronizer {
770	>	private static final long serialVersionUID = 2249069246763182397L;
771	>	transient TreeNode root;  // root of tree
772	>	transient TreeNode first; // head of next-pointer list
773	>
774	>	/* AQS overrides */
775	>	public final boolean isHeldExclusively() { return getState() > 0; }
776	>	public final boolean tryAcquire(int ignore) {
777	>	if (compareAndSetState(0, 1)) {
778	>	setExclusiveOwnerThread(Thread.currentThread());
779	>	return true;
780	>	}
781	>	return false;
782	>	}
783	>	public final boolean tryRelease(int ignore) {
784	>	setExclusiveOwnerThread(null);
785	>	setState(0);
786	>	return true;
787	>	}
788	>	public final int tryAcquireShared(int ignore) {
789	>	for (int c;;) {
790	>	if ((c = getState()) > 0)
791	>	return -1;
792	>	if (compareAndSetState(c, c -1))
793	>	return 1;
794	>	}
795	>	}
796	>	public final boolean tryReleaseShared(int ignore) {
797	>	int c;
798	>	do {} while (!compareAndSetState(c = getState(), c + 1));
799	>	return c == -1;
800	>	}
801	>
802	>	/** From CLR */
803	>	private void rotateLeft(TreeNode p) {
804	>	if (p != null) {
805	>	TreeNode r = p.right, pp, rl;
806	>	if ((rl = p.right = r.left) != null)
807	>	rl.parent = p;
808	>	if ((pp = r.parent = p.parent) == null)
809	>	root = r;
810	>	else if (pp.left == p)
811	>	pp.left = r;
812	>	else
813	>	pp.right = r;
814	>	r.left = p;
815	>	p.parent = r;
816	>	}
817		}
818
819	<	@SuppressWarnings("unchecked")
820	<	static final <K,V> Segment<K,V>[] newArray(int i) {
821	<	return new Segment[i];
819	>	/** From CLR */
820	>	private void rotateRight(TreeNode p) {
821	>	if (p != null) {
822	>	TreeNode l = p.left, pp, lr;
823	>	if ((lr = p.left = l.right) != null)
824	>	lr.parent = p;
825	>	if ((pp = l.parent = p.parent) == null)
826	>	root = l;
827	>	else if (pp.right == p)
828	>	pp.right = l;
829	>	else
830	>	pp.left = l;
831	>	l.right = p;
832	>	p.parent = l;
833	>	}
834		}
835
836		/**
837	<	* Sets table to new HashEntry array.
838	<	* Call only while holding lock or in constructor.
837	>	* Returns the TreeNode (or null if not found) for the given key
838	>	* starting at given root.
839		*/
840	<	void setTable(HashEntry<K,V>[] newTable) {
841	<	threshold = (int)(newTable.length * loadFactor);
842	<	table = newTable;
840	>	@SuppressWarnings("unchecked") final TreeNode getTreeNode
841	>	(int h, Object k, TreeNode p) {
842	>	Class<?> c = k.getClass();
843	>	while (p != null) {
844	>	int dir, ph;  Object pk; Class<?> pc;
845	>	if ((ph = p.hash) == h) {
846	>	if ((pk = p.key) == k || k.equals(pk))
847	>	return p;
848	>	if (c != (pc = pk.getClass()) ||
849	>	!(k instanceof Comparable) ||
850	>	(dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
851	>	dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName());
852	>	TreeNode r = null, s = null, pl, pr;
853	>	if (dir >= 0) {
854	>	if ((pl = p.left) != null && h <= pl.hash)
855	>	s = pl;
856	>	}
857	>	else if ((pr = p.right) != null && h >= pr.hash)
858	>	s = pr;
859	>	if (s != null && (r = getTreeNode(h, k, s)) != null)
860	>	return r;
861	>	}
862	>	}
863	>	else
864	>	dir = (h < ph) ? -1 : 1;
865	>	p = (dir > 0) ? p.right : p.left;
866	>	}
867	>	return null;
868		}
869
870		/**
871	<	* Returns properly casted first entry of bin for given hash.
871	>	* Wrapper for getTreeNode used by CHM.get. Tries to obtain
872	>	* read-lock to call getTreeNode, but during failure to get
873	>	* lock, searches along next links.
874		*/
875	<	HashEntry<K,V> getFirst(int hash) {
876	<	HashEntry<K,V>[] tab = table;
877	<	return tab[hash & (tab.length - 1)];
875	>	final Object getValue(int h, Object k) {
876	>	Node r = null;
877	>	int c = getState(); // Must read lock state first
878	>	for (Node e = first; e != null; e = e.next) {
879	>	if (c <= 0 && compareAndSetState(c, c - 1)) {
880	>	try {
881	>	r = getTreeNode(h, k, root);
882	>	} finally {
883	>	releaseShared(0);
884	>	}
885	>	break;
886	>	}
887	>	else if ((e.hash & HASH_BITS) == h && k.equals(e.key)) {
888	>	r = e;
889	>	break;
890	>	}
891	>	else
892	>	c = getState();
893	>	}
894	>	return r == null ? null : r.val;
895		}
896
897		/**
898	<	* Reads value field of an entry under lock. Called if value
899	<	* field ever appears to be null. This is possible only if a
315	<	* compiler happens to reorder a HashEntry initialization with
316	<	* its table assignment, which is legal under memory model
317	<	* but is not known to ever occur.
898	>	* Finds or adds a node.
899	>	* @return null if added
900		*/
901	<	V readValueUnderLock(HashEntry<K,V> e) {
902	<	lock();
903	<	try {
904	<	return e.value;
905	<	} finally {
906	<	unlock();
901	>	@SuppressWarnings("unchecked") final TreeNode putTreeNode
902	>	(int h, Object k, Object v) {
903	>	Class<?> c = k.getClass();
904	>	TreeNode pp = root, p = null;
905	>	int dir = 0;
906	>	while (pp != null) { // find existing node or leaf to insert at
907	>	int ph;  Object pk; Class<?> pc;
908	>	p = pp;
909	>	if ((ph = p.hash) == h) {
910	>	if ((pk = p.key) == k || k.equals(pk))
911	>	return p;
912	>	if (c != (pc = pk.getClass()) ||
913	>	!(k instanceof Comparable) ||
914	>	(dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
915	>	dir = (c == pc) ? 0 : c.getName().compareTo(pc.getName());
916	>	TreeNode r = null, s = null, pl, pr;
917	>	if (dir >= 0) {
918	>	if ((pl = p.left) != null && h <= pl.hash)
919	>	s = pl;
920	>	}
921	>	else if ((pr = p.right) != null && h >= pr.hash)
922	>	s = pr;
923	>	if (s != null && (r = getTreeNode(h, k, s)) != null)
924	>	return r;
925	>	}
926	>	}
927	>	else
928	>	dir = (h < ph) ? -1 : 1;
929	>	pp = (dir > 0) ? p.right : p.left;
930		}
326	–	}
931
932	<	/* Specialized implementations of map methods */
933	<
934	<	V get(Object key, int hash) {
935	<	if (count != 0) { // read-volatile
936	<	HashEntry<K,V> e = getFirst(hash);
937	<	while (e != null) {
938	<	if (e.hash == hash && key.equals(e.key)) {
939	<	V v = e.value;
940	<	if (v != null)
941	<	return v;
942	<	return readValueUnderLock(e); // recheck
932	>	TreeNode f = first;
933	>	TreeNode x = first = new TreeNode(h, k, v, f, p);
934	>	if (p == null)
935	>	root = x;
936	>	else { // attach and rebalance; adapted from CLR
937	>	TreeNode xp, xpp;
938	>	if (f != null)
939	>	f.prev = x;
940	>	if (dir <= 0)
941	>	p.left = x;
942	>	else
943	>	p.right = x;
944	>	x.red = true;
945	>	while (x != null && (xp = x.parent) != null && xp.red &&
946	>	(xpp = xp.parent) != null) {
947	>	TreeNode xppl = xpp.left;
948	>	if (xp == xppl) {
949	>	TreeNode y = xpp.right;
950	>	if (y != null && y.red) {
951	>	y.red = false;
952	>	xp.red = false;
953	>	xpp.red = true;
954	>	x = xpp;
955	>	}
956	>	else {
957	>	if (x == xp.right) {
958	>	rotateLeft(x = xp);
959	>	xpp = (xp = x.parent) == null ? null : xp.parent;
960	>	}
961	>	if (xp != null) {
962	>	xp.red = false;
963	>	if (xpp != null) {
964	>	xpp.red = true;
965	>	rotateRight(xpp);
966	>	}
967	>	}
968	>	}
969	>	}
970	>	else {
971	>	TreeNode y = xppl;
972	>	if (y != null && y.red) {
973	>	y.red = false;
974	>	xp.red = false;
975	>	xpp.red = true;
976	>	x = xpp;
977	>	}
978	>	else {
979	>	if (x == xp.left) {
980	>	rotateRight(x = xp);
981	>	xpp = (xp = x.parent) == null ? null : xp.parent;
982	>	}
983	>	if (xp != null) {
984	>	xp.red = false;
985	>	if (xpp != null) {
986	>	xpp.red = true;
987	>	rotateLeft(xpp);
988	>	}
989	>	}
990	>	}
991		}
340	–	e = e.next;
992		}
993	+	TreeNode r = root;
994	+	if (r != null && r.red)
995	+	r.red = false;
996		}
997		return null;
998		}
999
1000	<	boolean containsKey(Object key, int hash) {
1001	<	if (count != 0) { // read-volatile
1002	<	HashEntry<K,V> e = getFirst(hash);
1003	<	while (e != null) {
1004	<	if (e.hash == hash && key.equals(e.key))
1005	<	return true;
1006	<	e = e.next;
1000	>	/**
1001	>	* Removes the given node, that must be present before this
1002	>	* call.  This is messier than typical red-black deletion code
1003	>	* because we cannot swap the contents of an interior node
1004	>	* with a leaf successor that is pinned by "next" pointers
1005	>	* that are accessible independently of lock. So instead we
1006	>	* swap the tree linkages.
1007	>	*/
1008	>	final void deleteTreeNode(TreeNode p) {
1009	>	TreeNode next = (TreeNode)p.next; // unlink traversal pointers
1010	>	TreeNode pred = p.prev;
1011	>	if (pred == null)
1012	>	first = next;
1013	>	else
1014	>	pred.next = next;
1015	>	if (next != null)
1016	>	next.prev = pred;
1017	>	TreeNode replacement;
1018	>	TreeNode pl = p.left;
1019	>	TreeNode pr = p.right;
1020	>	if (pl != null && pr != null) {
1021	>	TreeNode s = pr, sl;
1022	>	while ((sl = s.left) != null) // find successor
1023	>	s = sl;
1024	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
1025	>	TreeNode sr = s.right;
1026	>	TreeNode pp = p.parent;
1027	>	if (s == pr) { // p was s's direct parent
1028	>	p.parent = s;
1029	>	s.right = p;
1030	>	}
1031	>	else {
1032	>	TreeNode sp = s.parent;
1033	>	if ((p.parent = sp) != null) {
1034	>	if (s == sp.left)
1035	>	sp.left = p;
1036	>	else
1037	>	sp.right = p;
1038	>	}
1039	>	if ((s.right = pr) != null)
1040	>	pr.parent = s;
1041		}
1042	+	p.left = null;
1043	+	if ((p.right = sr) != null)
1044	+	sr.parent = p;
1045	+	if ((s.left = pl) != null)
1046	+	pl.parent = s;
1047	+	if ((s.parent = pp) == null)
1048	+	root = s;
1049	+	else if (p == pp.left)
1050	+	pp.left = s;
1051	+	else
1052	+	pp.right = s;
1053	+	replacement = sr;
1054		}
1055	<	return false;
1055	>	else
1056	>	replacement = (pl != null) ? pl : pr;
1057	>	TreeNode pp = p.parent;
1058	>	if (replacement == null) {
1059	>	if (pp == null) {
1060	>	root = null;
1061	>	return;
1062	>	}
1063	>	replacement = p;
1064	>	}
1065	>	else {
1066	>	replacement.parent = pp;
1067	>	if (pp == null)
1068	>	root = replacement;
1069	>	else if (p == pp.left)
1070	>	pp.left = replacement;
1071	>	else
1072	>	pp.right = replacement;
1073	>	p.left = p.right = p.parent = null;
1074	>	}
1075	>	if (!p.red) { // rebalance, from CLR
1076	>	TreeNode x = replacement;
1077	>	while (x != null) {
1078	>	TreeNode xp, xpl;
1079	>	if (x.red || (xp = x.parent) == null) {
1080	>	x.red = false;
1081	>	break;
1082	>	}
1083	>	if (x == (xpl = xp.left)) {
1084	>	TreeNode sib = xp.right;
1085	>	if (sib != null && sib.red) {
1086	>	sib.red = false;
1087	>	xp.red = true;
1088	>	rotateLeft(xp);
1089	>	sib = (xp = x.parent) == null ? null : xp.right;
1090	>	}
1091	>	if (sib == null)
1092	>	x = xp;
1093	>	else {
1094	>	TreeNode sl = sib.left, sr = sib.right;
1095	>	if ((sr == null || !sr.red) &&
1096	>	(sl == null || !sl.red)) {
1097	>	sib.red = true;
1098	>	x = xp;
1099	>	}
1100	>	else {
1101	>	if (sr == null || !sr.red) {
1102	>	if (sl != null)
1103	>	sl.red = false;
1104	>	sib.red = true;
1105	>	rotateRight(sib);
1106	>	sib = (xp = x.parent) == null ? null : xp.right;
1107	>	}
1108	>	if (sib != null) {
1109	>	sib.red = (xp == null) ? false : xp.red;
1110	>	if ((sr = sib.right) != null)
1111	>	sr.red = false;
1112	>	}
1113	>	if (xp != null) {
1114	>	xp.red = false;
1115	>	rotateLeft(xp);
1116	>	}
1117	>	x = root;
1118	>	}
1119	>	}
1120	>	}
1121	>	else { // symmetric
1122	>	TreeNode sib = xpl;
1123	>	if (sib != null && sib.red) {
1124	>	sib.red = false;
1125	>	xp.red = true;
1126	>	rotateRight(xp);
1127	>	sib = (xp = x.parent) == null ? null : xp.left;
1128	>	}
1129	>	if (sib == null)
1130	>	x = xp;
1131	>	else {
1132	>	TreeNode sl = sib.left, sr = sib.right;
1133	>	if ((sl == null || !sl.red) &&
1134	>	(sr == null || !sr.red)) {
1135	>	sib.red = true;
1136	>	x = xp;
1137	>	}
1138	>	else {
1139	>	if (sl == null || !sl.red) {
1140	>	if (sr != null)
1141	>	sr.red = false;
1142	>	sib.red = true;
1143	>	rotateLeft(sib);
1144	>	sib = (xp = x.parent) == null ? null : xp.left;
1145	>	}
1146	>	if (sib != null) {
1147	>	sib.red = (xp == null) ? false : xp.red;
1148	>	if ((sl = sib.left) != null)
1149	>	sl.red = false;
1150	>	}
1151	>	if (xp != null) {
1152	>	xp.red = false;
1153	>	rotateRight(xp);
1154	>	}
1155	>	x = root;
1156	>	}
1157	>	}
1158	>	}
1159	>	}
1160	>	}
1161	>	if (p == replacement && (pp = p.parent) != null) {
1162	>	if (p == pp.left) // detach pointers
1163	>	pp.left = null;
1164	>	else if (p == pp.right)
1165	>	pp.right = null;
1166	>	p.parent = null;
1167	>	}
1168	>	}
1169	>	}
1170	>
1171	>	/* ---------------- Collision reduction methods -------------- */
1172	>
1173	>	/**
1174	>	* Spreads higher bits to lower, and also forces top 2 bits to 0.
1175	>	* Because the table uses power-of-two masking, sets of hashes
1176	>	* that vary only in bits above the current mask will always
1177	>	* collide. (Among known examples are sets of Float keys holding
1178	>	* consecutive whole numbers in small tables.)  To counter this,
1179	>	* we apply a transform that spreads the impact of higher bits
1180	>	* downward. There is a tradeoff between speed, utility, and
1181	>	* quality of bit-spreading. Because many common sets of hashes
1182	>	* are already reasonably distributed across bits (so don't benefit
1183	>	* from spreading), and because we use trees to handle large sets
1184	>	* of collisions in bins, we don't need excessively high quality.
1185	>	*/
1186	>	private static final int spread(int h) {
1187	>	h ^= (h >>> 18) ^ (h >>> 12);
1188	>	return (h ^ (h >>> 10)) & HASH_BITS;
1189	>	}
1190	>
1191	>	/**
1192	>	* Replaces a list bin with a tree bin. Call only when locked.
1193	>	* Fails to replace if the given key is non-comparable or table
1194	>	* is, or needs, resizing.
1195	>	*/
1196	>	private final void replaceWithTreeBin(Node[] tab, int index, Object key) {
1197	>	if ((key instanceof Comparable) &&
1198	>	(tab.length >= MAXIMUM_CAPACITY || counter.sum() < (long)sizeCtl)) {
1199	>	TreeBin t = new TreeBin();
1200	>	for (Node e = tabAt(tab, index); e != null; e = e.next)
1201	>	t.putTreeNode(e.hash & HASH_BITS, e.key, e.val);
1202	>	setTabAt(tab, index, new Node(MOVED, t, null, null));
1203		}
1204	+	}
1205
1206	<	boolean containsValue(Object value) {
1207	<	if (count != 0) { // read-volatile
1208	<	HashEntry<K,V>[] tab = table;
1209	<	int len = tab.length;
1210	<	for (int i = 0 ; i < len; i++) {
1211	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
1212	<	V v = e.value;
1213	<	if (v == null) // recheck
1214	<	v = readValueUnderLock(e);
1215	<	if (value.equals(v))
1216	<	return true;
1206	>	/* ---------------- Internal access and update methods -------------- */
1207	>
1208	>	/** Implementation for get and containsKey */
1209	>	private final Object internalGet(Object k) {
1210	>	int h = spread(k.hashCode());
1211	>	retry: for (Node[] tab = table; tab != null;) {
1212	>	Node e, p; Object ek, ev; int eh;      // locals to read fields once
1213	>	for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
1214	>	if ((eh = e.hash) == MOVED) {
1215	>	if ((ek = e.key) instanceof TreeBin)  // search TreeBin
1216	>	return ((TreeBin)ek).getValue(h, k);
1217	>	else {                        // restart with new table
1218	>	tab = (Node[])ek;
1219	>	continue retry;
1220		}
1221		}
1222	+	else if ((eh & HASH_BITS) == h && (ev = e.val) != null &&
1223	+	((ek = e.key) == k || k.equals(ek)))
1224	+	return ev;
1225		}
1226	<	return false;
1226	>	break;
1227		}
1228	+	return null;
1229	+	}
1230
1231	<	boolean replace(K key, int hash, V oldValue, V newValue) {
1232	<	lock();
1233	<	try {
1234	<	HashEntry<K,V> e = getFirst(hash);
1235	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1236	<	e = e.next;
1237	<
1238	<	boolean replaced = false;
1239	<	if (e != null && oldValue.equals(e.value)) {
1240	<	replaced = true;
1241	<	e.value = newValue;
1231	>	/**
1232	>	* Implementation for the four public remove/replace methods:
1233	>	* Replaces node value with v, conditional upon match of cv if
1234	>	* non-null.  If resulting value is null, delete.
1235	>	*/
1236	>	private final Object internalReplace(Object k, Object v, Object cv) {
1237	>	int h = spread(k.hashCode());
1238	>	Object oldVal = null;
1239	>	for (Node[] tab = table;;) {
1240	>	Node f; int i, fh; Object fk;
1241	>	if (tab == null ||
1242	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1243	>	break;
1244	>	else if ((fh = f.hash) == MOVED) {
1245	>	if ((fk = f.key) instanceof TreeBin) {
1246	>	TreeBin t = (TreeBin)fk;
1247	>	boolean validated = false;
1248	>	boolean deleted = false;
1249	>	t.acquire(0);
1250	>	try {
1251	>	if (tabAt(tab, i) == f) {
1252	>	validated = true;
1253	>	TreeNode p = t.getTreeNode(h, k, t.root);
1254	>	if (p != null) {
1255	>	Object pv = p.val;
1256	>	if (cv == null || cv == pv || cv.equals(pv)) {
1257	>	oldVal = pv;
1258	>	if ((p.val = v) == null) {
1259	>	deleted = true;
1260	>	t.deleteTreeNode(p);
1261	>	}
1262	>	}
1263	>	}
1264	>	}
1265	>	} finally {
1266	>	t.release(0);
1267	>	}
1268	>	if (validated) {
1269	>	if (deleted)
1270	>	counter.add(-1L);
1271	>	break;
1272	>	}
1273	>	}
1274	>	else
1275	>	tab = (Node[])fk;
1276	>	}
1277	>	else if ((fh & HASH_BITS) != h && f.next == null) // precheck
1278	>	break;                          // rules out possible existence
1279	>	else if ((fh & LOCKED) != 0) {
1280	>	checkForResize();               // try resizing if can't get lock
1281	>	f.tryAwaitLock(tab, i);
1282	>	}
1283	>	else if (f.casHash(fh, fh | LOCKED)) {
1284	>	boolean validated = false;
1285	>	boolean deleted = false;
1286	>	try {
1287	>	if (tabAt(tab, i) == f) {
1288	>	validated = true;
1289	>	for (Node e = f, pred = null;;) {
1290	>	Object ek, ev;
1291	>	if ((e.hash & HASH_BITS) == h &&
1292	>	((ev = e.val) != null) &&
1293	>	((ek = e.key) == k || k.equals(ek))) {
1294	>	if (cv == null || cv == ev || cv.equals(ev)) {
1295	>	oldVal = ev;
1296	>	if ((e.val = v) == null) {
1297	>	deleted = true;
1298	>	Node en = e.next;
1299	>	if (pred != null)
1300	>	pred.next = en;
1301	>	else
1302	>	setTabAt(tab, i, en);
1303	>	}
1304	>	}
1305	>	break;
1306	>	}
1307	>	pred = e;
1308	>	if ((e = e.next) == null)
1309	>	break;
1310	>	}
1311	>	}
1312	>	} finally {
1313	>	if (!f.casHash(fh | LOCKED, fh)) {
1314	>	f.hash = fh;
1315	>	synchronized (f) { f.notifyAll(); };
1316	>	}
1317	>	}
1318	>	if (validated) {
1319	>	if (deleted)
1320	>	counter.add(-1L);
1321	>	break;
1322		}
387	–	return replaced;
388	–	} finally {
389	–	unlock();
1323		}
1324		}
1325	+	return oldVal;
1326	+	}
1327
1328	<	V replace(K key, int hash, V newValue) {
1329	<	lock();
1330	<	try {
1331	<	HashEntry<K,V> e = getFirst(hash);
1332	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1333	<	e = e.next;
1328	>	/*
1329	>	* Internal versions of the six insertion methods, each a
1330	>	* little more complicated than the last. All have
1331	>	* the same basic structure as the first (internalPut):
1332	>	*  1. If table uninitialized, create
1333	>	*  2. If bin empty, try to CAS new node
1334	>	*  3. If bin stale, use new table
1335	>	*  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1336	>	*  5. Lock and validate; if valid, scan and add or update
1337	>	*
1338	>	* The others interweave other checks and/or alternative actions:
1339	>	*  * Plain put checks for and performs resize after insertion.
1340	>	*  * putIfAbsent prescans for mapping without lock (and fails to add
1341	>	*    if present), which also makes pre-emptive resize checks worthwhile.
1342	>	*  * computeIfAbsent extends form used in putIfAbsent with additional
1343	>	*    mechanics to deal with, calls, potential exceptions and null
1344	>	*    returns from function call.
1345	>	*  * compute uses the same function-call mechanics, but without
1346	>	*    the prescans
1347	>	*  * merge acts as putIfAbsent in the absent case, but invokes the
1348	>	*    update function if present
1349	>	*  * putAll attempts to pre-allocate enough table space
1350	>	*    and more lazily performs count updates and checks.
1351	>	*
1352	>	* Someday when details settle down a bit more, it might be worth
1353	>	* some factoring to reduce sprawl.
1354	>	*/
1355
1356	<	V oldValue = null;
1357	<	if (e != null) {
1358	<	oldValue = e.value;
1359	<	e.value = newValue;
1356	>	/** Implementation for put */
1357	>	private final Object internalPut(Object k, Object v) {
1358	>	int h = spread(k.hashCode());
1359	>	int count = 0;
1360	>	for (Node[] tab = table;;) {
1361	>	int i; Node f; int fh; Object fk;
1362	>	if (tab == null)
1363	>	tab = initTable();
1364	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1365	>	if (casTabAt(tab, i, null, new Node(h, k, v, null)))
1366	>	break;                   // no lock when adding to empty bin
1367	>	}
1368	>	else if ((fh = f.hash) == MOVED) {
1369	>	if ((fk = f.key) instanceof TreeBin) {
1370	>	TreeBin t = (TreeBin)fk;
1371	>	Object oldVal = null;
1372	>	t.acquire(0);
1373	>	try {
1374	>	if (tabAt(tab, i) == f) {
1375	>	count = 2;
1376	>	TreeNode p = t.putTreeNode(h, k, v);
1377	>	if (p != null) {
1378	>	oldVal = p.val;
1379	>	p.val = v;
1380	>	}
1381	>	}
1382	>	} finally {
1383	>	t.release(0);
1384	>	}
1385	>	if (count != 0) {
1386	>	if (oldVal != null)
1387	>	return oldVal;
1388	>	break;
1389	>	}
1390	>	}
1391	>	else
1392	>	tab = (Node[])fk;
1393	>	}
1394	>	else if ((fh & LOCKED) != 0) {
1395	>	checkForResize();
1396	>	f.tryAwaitLock(tab, i);
1397	>	}
1398	>	else if (f.casHash(fh, fh | LOCKED)) {
1399	>	Object oldVal = null;
1400	>	try {                        // needed in case equals() throws
1401	>	if (tabAt(tab, i) == f) {
1402	>	count = 1;
1403	>	for (Node e = f;; ++count) {
1404	>	Object ek, ev;
1405	>	if ((e.hash & HASH_BITS) == h &&
1406	>	(ev = e.val) != null &&
1407	>	((ek = e.key) == k || k.equals(ek))) {
1408	>	oldVal = ev;
1409	>	e.val = v;
1410	>	break;
1411	>	}
1412	>	Node last = e;
1413	>	if ((e = e.next) == null) {
1414	>	last.next = new Node(h, k, v, null);
1415	>	if (count >= TREE_THRESHOLD)
1416	>	replaceWithTreeBin(tab, i, k);
1417	>	break;
1418	>	}
1419	>	}
1420	>	}
1421	>	} finally {                  // unlock and signal if needed
1422	>	if (!f.casHash(fh | LOCKED, fh)) {
1423	>	f.hash = fh;
1424	>	synchronized (f) { f.notifyAll(); };
1425	>	}
1426	>	}
1427	>	if (count != 0) {
1428	>	if (oldVal != null)
1429	>	return oldVal;
1430	>	if (tab.length <= 64)
1431	>	count = 2;
1432	>	break;
1433		}
405	–	return oldValue;
406	–	} finally {
407	–	unlock();
1434		}
1435		}
1436	+	counter.add(1L);
1437	+	if (count > 1)
1438	+	checkForResize();
1439	+	return null;
1440	+	}
1441
1442	+	/** Implementation for putIfAbsent */
1443	+	private final Object internalPutIfAbsent(Object k, Object v) {
1444	+	int h = spread(k.hashCode());
1445	+	int count = 0;
1446	+	for (Node[] tab = table;;) {
1447	+	int i; Node f; int fh; Object fk, fv;
1448	+	if (tab == null)
1449	+	tab = initTable();
1450	+	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1451	+	if (casTabAt(tab, i, null, new Node(h, k, v, null)))
1452	+	break;
1453	+	}
1454	+	else if ((fh = f.hash) == MOVED) {
1455	+	if ((fk = f.key) instanceof TreeBin) {
1456	+	TreeBin t = (TreeBin)fk;
1457	+	Object oldVal = null;
1458	+	t.acquire(0);
1459	+	try {
1460	+	if (tabAt(tab, i) == f) {
1461	+	count = 2;
1462	+	TreeNode p = t.putTreeNode(h, k, v);
1463	+	if (p != null)
1464	+	oldVal = p.val;
1465	+	}
1466	+	} finally {
1467	+	t.release(0);
1468	+	}
1469	+	if (count != 0) {
1470	+	if (oldVal != null)
1471	+	return oldVal;
1472	+	break;
1473	+	}
1474	+	}
1475	+	else
1476	+	tab = (Node[])fk;
1477	+	}
1478	+	else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
1479	+	((fk = f.key) == k || k.equals(fk)))
1480	+	return fv;
1481	+	else {
1482	+	Node g = f.next;
1483	+	if (g != null) { // at least 2 nodes -- search and maybe resize
1484	+	for (Node e = g;;) {
1485	+	Object ek, ev;
1486	+	if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
1487	+	((ek = e.key) == k || k.equals(ek)))
1488	+	return ev;
1489	+	if ((e = e.next) == null) {
1490	+	checkForResize();
1491	+	break;
1492	+	}
1493	+	}
1494	+	}
1495	+	if (((fh = f.hash) & LOCKED) != 0) {
1496	+	checkForResize();
1497	+	f.tryAwaitLock(tab, i);
1498	+	}
1499	+	else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
1500	+	Object oldVal = null;
1501	+	try {
1502	+	if (tabAt(tab, i) == f) {
1503	+	count = 1;
1504	+	for (Node e = f;; ++count) {
1505	+	Object ek, ev;
1506	+	if ((e.hash & HASH_BITS) == h &&
1507	+	(ev = e.val) != null &&
1508	+	((ek = e.key) == k || k.equals(ek))) {
1509	+	oldVal = ev;
1510	+	break;
1511	+	}
1512	+	Node last = e;
1513	+	if ((e = e.next) == null) {
1514	+	last.next = new Node(h, k, v, null);
1515	+	if (count >= TREE_THRESHOLD)
1516	+	replaceWithTreeBin(tab, i, k);
1517	+	break;
1518	+	}
1519	+	}
1520	+	}
1521	+	} finally {
1522	+	if (!f.casHash(fh | LOCKED, fh)) {
1523	+	f.hash = fh;
1524	+	synchronized (f) { f.notifyAll(); };
1525	+	}
1526	+	}
1527	+	if (count != 0) {
1528	+	if (oldVal != null)
1529	+	return oldVal;
1530	+	if (tab.length <= 64)
1531	+	count = 2;
1532	+	break;
1533	+	}
1534	+	}
1535	+	}
1536	+	}
1537	+	counter.add(1L);
1538	+	if (count > 1)
1539	+	checkForResize();
1540	+	return null;
1541	+	}
1542
1543	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1544	<	lock();
1545	<	try {
1546	<	int c = count;
1547	<	if (c++ > threshold) // ensure capacity
1548	<	rehash();
1549	<	HashEntry<K,V>[] tab = table;
1550	<	int index = hash & (tab.length - 1);
1551	<	HashEntry<K,V> first = tab[index];
1552	<	HashEntry<K,V> e = first;
1553	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1554	<	e = e.next;
1555	<
1556	<	V oldValue;
1557	<	if (e != null) {
1558	<	oldValue = e.value;
1559	<	if (!onlyIfAbsent)
1560	<	e.value = value;
1543	>	/** Implementation for computeIfAbsent */
1544	>	private final Object internalComputeIfAbsent(K k,
1545	>	Fun<? super K, ?> mf) {
1546	>	int h = spread(k.hashCode());
1547	>	Object val = null;
1548	>	int count = 0;
1549	>	for (Node[] tab = table;;) {
1550	>	Node f; int i, fh; Object fk, fv;
1551	>	if (tab == null)
1552	>	tab = initTable();
1553	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1554	>	Node node = new Node(fh = h | LOCKED, k, null, null);
1555	>	if (casTabAt(tab, i, null, node)) {
1556	>	count = 1;
1557	>	try {
1558	>	if ((val = mf.apply(k)) != null)
1559	>	node.val = val;
1560	>	} finally {
1561	>	if (val == null)
1562	>	setTabAt(tab, i, null);
1563	>	if (!node.casHash(fh, h)) {
1564	>	node.hash = h;
1565	>	synchronized (node) { node.notifyAll(); };
1566	>	}
1567	>	}
1568		}
1569	<	else {
1570	<	oldValue = null;
1571	<	++modCount;
1572	<	tab[index] = new HashEntry<K,V>(key, hash, first, value);
1573	<	count = c; // write-volatile
1569	>	if (count != 0)
1570	>	break;
1571	>	}
1572	>	else if ((fh = f.hash) == MOVED) {
1573	>	if ((fk = f.key) instanceof TreeBin) {
1574	>	TreeBin t = (TreeBin)fk;
1575	>	boolean added = false;
1576	>	t.acquire(0);
1577	>	try {
1578	>	if (tabAt(tab, i) == f) {
1579	>	count = 1;
1580	>	TreeNode p = t.getTreeNode(h, k, t.root);
1581	>	if (p != null)
1582	>	val = p.val;
1583	>	else if ((val = mf.apply(k)) != null) {
1584	>	added = true;
1585	>	count = 2;
1586	>	t.putTreeNode(h, k, val);
1587	>	}
1588	>	}
1589	>	} finally {
1590	>	t.release(0);
1591	>	}
1592	>	if (count != 0) {
1593	>	if (!added)
1594	>	return val;
1595	>	break;
1596	>	}
1597	>	}
1598	>	else
1599	>	tab = (Node[])fk;
1600	>	}
1601	>	else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
1602	>	((fk = f.key) == k || k.equals(fk)))
1603	>	return fv;
1604	>	else {
1605	>	Node g = f.next;
1606	>	if (g != null) {
1607	>	for (Node e = g;;) {
1608	>	Object ek, ev;
1609	>	if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
1610	>	((ek = e.key) == k || k.equals(ek)))
1611	>	return ev;
1612	>	if ((e = e.next) == null) {
1613	>	checkForResize();
1614	>	break;
1615	>	}
1616	>	}
1617	>	}
1618	>	if (((fh = f.hash) & LOCKED) != 0) {
1619	>	checkForResize();
1620	>	f.tryAwaitLock(tab, i);
1621	>	}
1622	>	else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
1623	>	boolean added = false;
1624	>	try {
1625	>	if (tabAt(tab, i) == f) {
1626	>	count = 1;
1627	>	for (Node e = f;; ++count) {
1628	>	Object ek, ev;
1629	>	if ((e.hash & HASH_BITS) == h &&
1630	>	(ev = e.val) != null &&
1631	>	((ek = e.key) == k || k.equals(ek))) {
1632	>	val = ev;
1633	>	break;
1634	>	}
1635	>	Node last = e;
1636	>	if ((e = e.next) == null) {
1637	>	if ((val = mf.apply(k)) != null) {
1638	>	added = true;
1639	>	last.next = new Node(h, k, val, null);
1640	>	if (count >= TREE_THRESHOLD)
1641	>	replaceWithTreeBin(tab, i, k);
1642	>	}
1643	>	break;
1644	>	}
1645	>	}
1646	>	}
1647	>	} finally {
1648	>	if (!f.casHash(fh | LOCKED, fh)) {
1649	>	f.hash = fh;
1650	>	synchronized (f) { f.notifyAll(); };
1651	>	}
1652	>	}
1653	>	if (count != 0) {
1654	>	if (!added)
1655	>	return val;
1656	>	if (tab.length <= 64)
1657	>	count = 2;
1658	>	break;
1659	>	}
1660		}
437	–	return oldValue;
438	–	} finally {
439	–	unlock();
1661		}
1662		}
1663	+	if (val != null) {
1664	+	counter.add(1L);
1665	+	if (count > 1)
1666	+	checkForResize();
1667	+	}
1668	+	return val;
1669	+	}
1670
1671	<	void rehash() {
1672	<	HashEntry<K,V>[] oldTable = table;
1673	<	int oldCapacity = oldTable.length;
1674	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1675	<	return;
1676	<
1677	<	/*
1678	<	* Reclassify nodes in each list to new Map.  Because we are
1679	<	* using power-of-two expansion, the elements from each bin
1680	<	* must either stay at same index, or move with a power of two
1681	<	* offset. We eliminate unnecessary node creation by catching
1682	<	* cases where old nodes can be reused because their next
1683	<	* fields won't change. Statistically, at the default
1684	<	* threshold, only about one-sixth of them need cloning when
1685	<	* a table doubles. The nodes they replace will be garbage
1686	<	* collectable as soon as they are no longer referenced by any
1687	<	* reader thread that may be in the midst of traversing table
1688	<	* right now.
1689	<	*/
1690	<
1691	<	HashEntry<K,V>[] newTable = HashEntry.newArray(oldCapacity<<1);
1692	<	threshold = (int)(newTable.length * loadFactor);
1693	<	int sizeMask = newTable.length - 1;
1694	<	for (int i = 0; i < oldCapacity ; i++) {
1695	<	// We need to guarantee that any existing reads of old Map can
1696	<	//  proceed. So we cannot yet null out each bin.
1697	<	HashEntry<K,V> e = oldTable[i];
1698	<
1699	<	if (e != null) {
1700	<	HashEntry<K,V> next = e.next;
1701	<	int idx = e.hash & sizeMask;
1702	<
1703	<	//  Single node on list
1704	<	if (next == null)
1705	<	newTable[idx] = e;
1671	>	/** Implementation for compute */
1672	>	@SuppressWarnings("unchecked") private final Object internalCompute
1673	>	(K k, boolean onlyIfPresent, BiFun<? super K, ? super V, ? extends V> mf) {
1674	>	int h = spread(k.hashCode());
1675	>	Object val = null;
1676	>	int delta = 0;
1677	>	int count = 0;
1678	>	for (Node[] tab = table;;) {
1679	>	Node f; int i, fh; Object fk;
1680	>	if (tab == null)
1681	>	tab = initTable();
1682	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1683	>	if (onlyIfPresent)
1684	>	break;
1685	>	Node node = new Node(fh = h | LOCKED, k, null, null);
1686	>	if (casTabAt(tab, i, null, node)) {
1687	>	try {
1688	>	count = 1;
1689	>	if ((val = mf.apply(k, null)) != null) {
1690	>	node.val = val;
1691	>	delta = 1;
1692	>	}
1693	>	} finally {
1694	>	if (delta == 0)
1695	>	setTabAt(tab, i, null);
1696	>	if (!node.casHash(fh, h)) {
1697	>	node.hash = h;
1698	>	synchronized (node) { node.notifyAll(); };
1699	>	}
1700	>	}
1701	>	}
1702	>	if (count != 0)
1703	>	break;
1704	>	}
1705	>	else if ((fh = f.hash) == MOVED) {
1706	>	if ((fk = f.key) instanceof TreeBin) {
1707	>	TreeBin t = (TreeBin)fk;
1708	>	t.acquire(0);
1709	>	try {
1710	>	if (tabAt(tab, i) == f) {
1711	>	count = 1;
1712	>	TreeNode p = t.getTreeNode(h, k, t.root);
1713	>	Object pv = (p == null) ? null : p.val;
1714	>	if ((val = mf.apply(k, (V)pv)) != null) {
1715	>	if (p != null)
1716	>	p.val = val;
1717	>	else {
1718	>	count = 2;
1719	>	delta = 1;
1720	>	t.putTreeNode(h, k, val);
1721	>	}
1722	>	}
1723	>	else if (p != null) {
1724	>	delta = -1;
1725	>	t.deleteTreeNode(p);
1726	>	}
1727	>	}
1728	>	} finally {
1729	>	t.release(0);
1730	>	}
1731	>	if (count != 0)
1732	>	break;
1733	>	}
1734	>	else
1735	>	tab = (Node[])fk;
1736	>	}
1737	>	else if ((fh & LOCKED) != 0) {
1738	>	checkForResize();
1739	>	f.tryAwaitLock(tab, i);
1740	>	}
1741	>	else if (f.casHash(fh, fh | LOCKED)) {
1742	>	try {
1743	>	if (tabAt(tab, i) == f) {
1744	>	count = 1;
1745	>	for (Node e = f, pred = null;; ++count) {
1746	>	Object ek, ev;
1747	>	if ((e.hash & HASH_BITS) == h &&
1748	>	(ev = e.val) != null &&
1749	>	((ek = e.key) == k || k.equals(ek))) {
1750	>	val = mf.apply(k, (V)ev);
1751	>	if (val != null)
1752	>	e.val = val;
1753	>	else {
1754	>	delta = -1;
1755	>	Node en = e.next;
1756	>	if (pred != null)
1757	>	pred.next = en;
1758	>	else
1759	>	setTabAt(tab, i, en);
1760	>	}
1761	>	break;
1762	>	}
1763	>	pred = e;
1764	>	if ((e = e.next) == null) {
1765	>	if (!onlyIfPresent && (val = mf.apply(k, null)) != null) {
1766	>	pred.next = new Node(h, k, val, null);
1767	>	delta = 1;
1768	>	if (count >= TREE_THRESHOLD)
1769	>	replaceWithTreeBin(tab, i, k);
1770	>	}
1771	>	break;
1772	>	}
1773	>	}
1774	>	}
1775	>	} finally {
1776	>	if (!f.casHash(fh | LOCKED, fh)) {
1777	>	f.hash = fh;
1778	>	synchronized (f) { f.notifyAll(); };
1779	>	}
1780	>	}
1781	>	if (count != 0) {
1782	>	if (tab.length <= 64)
1783	>	count = 2;
1784	>	break;
1785	>	}
1786	>	}
1787	>	}
1788	>	if (delta != 0) {
1789	>	counter.add((long)delta);
1790	>	if (count > 1)
1791	>	checkForResize();
1792	>	}
1793	>	return val;
1794	>	}
1795
1796	<	else {
1797	<	// Reuse trailing consecutive sequence at same slot
1798	<	HashEntry<K,V> lastRun = e;
1799	<	int lastIdx = idx;
1800	<	for (HashEntry<K,V> last = next;
1801	<	last != null;
1802	<	last = last.next) {
1803	<	int k = last.hash & sizeMask;
1804	<	if (k != lastIdx) {
1805	<	lastIdx = k;
1806	<	lastRun = last;
1796	>	/** Implementation for merge */
1797	>	@SuppressWarnings("unchecked") private final Object internalMerge
1798	>	(K k, V v, BiFun<? super V, ? super V, ? extends V> mf) {
1799	>	int h = spread(k.hashCode());
1800	>	Object val = null;
1801	>	int delta = 0;
1802	>	int count = 0;
1803	>	for (Node[] tab = table;;) {
1804	>	int i; Node f; int fh; Object fk, fv;
1805	>	if (tab == null)
1806	>	tab = initTable();
1807	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1808	>	if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
1809	>	delta = 1;
1810	>	val = v;
1811	>	break;
1812	>	}
1813	>	}
1814	>	else if ((fh = f.hash) == MOVED) {
1815	>	if ((fk = f.key) instanceof TreeBin) {
1816	>	TreeBin t = (TreeBin)fk;
1817	>	t.acquire(0);
1818	>	try {
1819	>	if (tabAt(tab, i) == f) {
1820	>	count = 1;
1821	>	TreeNode p = t.getTreeNode(h, k, t.root);
1822	>	val = (p == null) ? v : mf.apply((V)p.val, v);
1823	>	if (val != null) {
1824	>	if (p != null)
1825	>	p.val = val;
1826	>	else {
1827	>	count = 2;
1828	>	delta = 1;
1829	>	t.putTreeNode(h, k, val);
1830	>	}
1831	>	}
1832	>	else if (p != null) {
1833	>	delta = -1;
1834	>	t.deleteTreeNode(p);
1835	>	}
1836	>	}
1837	>	} finally {
1838	>	t.release(0);
1839	>	}
1840	>	if (count != 0)
1841	>	break;
1842	>	}
1843	>	else
1844	>	tab = (Node[])fk;
1845	>	}
1846	>	else if ((fh & LOCKED) != 0) {
1847	>	checkForResize();
1848	>	f.tryAwaitLock(tab, i);
1849	>	}
1850	>	else if (f.casHash(fh, fh | LOCKED)) {
1851	>	try {
1852	>	if (tabAt(tab, i) == f) {
1853	>	count = 1;
1854	>	for (Node e = f, pred = null;; ++count) {
1855	>	Object ek, ev;
1856	>	if ((e.hash & HASH_BITS) == h &&
1857	>	(ev = e.val) != null &&
1858	>	((ek = e.key) == k || k.equals(ek))) {
1859	>	val = mf.apply(v, (V)ev);
1860	>	if (val != null)
1861	>	e.val = val;
1862	>	else {
1863	>	delta = -1;
1864	>	Node en = e.next;
1865	>	if (pred != null)
1866	>	pred.next = en;
1867	>	else
1868	>	setTabAt(tab, i, en);
1869	>	}
1870	>	break;
1871	>	}
1872	>	pred = e;
1873	>	if ((e = e.next) == null) {
1874	>	val = v;
1875	>	pred.next = new Node(h, k, val, null);
1876	>	delta = 1;
1877	>	if (count >= TREE_THRESHOLD)
1878	>	replaceWithTreeBin(tab, i, k);
1879	>	break;
1880		}
1881		}
1882	<	newTable[lastIdx] = lastRun;
1882	>	}
1883	>	} finally {
1884	>	if (!f.casHash(fh | LOCKED, fh)) {
1885	>	f.hash = fh;
1886	>	synchronized (f) { f.notifyAll(); };
1887	>	}
1888	>	}
1889	>	if (count != 0) {
1890	>	if (tab.length <= 64)
1891	>	count = 2;
1892	>	break;
1893	>	}
1894	>	}
1895	>	}
1896	>	if (delta != 0) {
1897	>	counter.add((long)delta);
1898	>	if (count > 1)
1899	>	checkForResize();
1900	>	}
1901	>	return val;
1902	>	}
1903
1904	<	// Clone all remaining nodes
1905	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1906	<	int k = p.hash & sizeMask;
1907	<	HashEntry<K,V> n = newTable[k];
1908	<	newTable[k] = new HashEntry<K,V>(p.key, p.hash,
1909	<	n, p.value);
1904	>	/** Implementation for putAll */
1905	>	private final void internalPutAll(Map<?, ?> m) {
1906	>	tryPresize(m.size());
1907	>	long delta = 0L;     // number of uncommitted additions
1908	>	boolean npe = false; // to throw exception on exit for nulls
1909	>	try {                // to clean up counts on other exceptions
1910	>	for (Map.Entry<?, ?> entry : m.entrySet()) {
1911	>	Object k, v;
1912	>	if (entry == null || (k = entry.getKey()) == null ||
1913	>	(v = entry.getValue()) == null) {
1914	>	npe = true;
1915	>	break;
1916	>	}
1917	>	int h = spread(k.hashCode());
1918	>	for (Node[] tab = table;;) {
1919	>	int i; Node f; int fh; Object fk;
1920	>	if (tab == null)
1921	>	tab = initTable();
1922	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1923	>	if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
1924	>	++delta;
1925	>	break;
1926	>	}
1927	>	}
1928	>	else if ((fh = f.hash) == MOVED) {
1929	>	if ((fk = f.key) instanceof TreeBin) {
1930	>	TreeBin t = (TreeBin)fk;
1931	>	boolean validated = false;
1932	>	t.acquire(0);
1933	>	try {
1934	>	if (tabAt(tab, i) == f) {
1935	>	validated = true;
1936	>	TreeNode p = t.getTreeNode(h, k, t.root);
1937	>	if (p != null)
1938	>	p.val = v;
1939	>	else {
1940	>	t.putTreeNode(h, k, v);
1941	>	++delta;
1942	>	}
1943	>	}
1944	>	} finally {
1945	>	t.release(0);
1946	>	}
1947	>	if (validated)
1948	>	break;
1949	>	}
1950	>	else
1951	>	tab = (Node[])fk;
1952	>	}
1953	>	else if ((fh & LOCKED) != 0) {
1954	>	counter.add(delta);
1955	>	delta = 0L;
1956	>	checkForResize();
1957	>	f.tryAwaitLock(tab, i);
1958	>	}
1959	>	else if (f.casHash(fh, fh | LOCKED)) {
1960	>	int count = 0;
1961	>	try {
1962	>	if (tabAt(tab, i) == f) {
1963	>	count = 1;
1964	>	for (Node e = f;; ++count) {
1965	>	Object ek, ev;
1966	>	if ((e.hash & HASH_BITS) == h &&
1967	>	(ev = e.val) != null &&
1968	>	((ek = e.key) == k || k.equals(ek))) {
1969	>	e.val = v;
1970	>	break;
1971	>	}
1972	>	Node last = e;
1973	>	if ((e = e.next) == null) {
1974	>	++delta;
1975	>	last.next = new Node(h, k, v, null);
1976	>	if (count >= TREE_THRESHOLD)
1977	>	replaceWithTreeBin(tab, i, k);
1978	>	break;
1979	>	}
1980	>	}
1981	>	}
1982	>	} finally {
1983	>	if (!f.casHash(fh | LOCKED, fh)) {
1984	>	f.hash = fh;
1985	>	synchronized (f) { f.notifyAll(); };
1986	>	}
1987	>	}
1988	>	if (count != 0) {
1989	>	if (count > 1) {
1990	>	counter.add(delta);
1991	>	delta = 0L;
1992	>	checkForResize();
1993	>	}
1994	>	break;
1995		}
1996		}
1997		}
1998		}
1999	<	table = newTable;
1999	>	} finally {
2000	>	if (delta != 0)
2001	>	counter.add(delta);
2002		}
2003	+	if (npe)
2004	+	throw new NullPointerException();
2005	+	}
2006
2007	<	/**
508	<	* Remove; match on key only if value null, else match both.
509	<	*/
510	<	V remove(Object key, int hash, Object value) {
511	<	lock();
512	<	try {
513	<	int c = count - 1;
514	<	HashEntry<K,V>[] tab = table;
515	<	int index = hash & (tab.length - 1);
516	<	HashEntry<K,V> first = tab[index];
517	<	HashEntry<K,V> e = first;
518	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
519	<	e = e.next;
2007	>	/* ---------------- Table Initialization and Resizing -------------- */
2008
2009	<	V oldValue = null;
2010	<	if (e != null) {
2011	<	V v = e.value;
2012	<	if (value == null || value.equals(v)) {
2013	<	oldValue = v;
2014	<	// All entries following removed node can stay
2015	<	// in list, but all preceding ones need to be
2016	<	// cloned.
2017	<	++modCount;
2018	<	HashEntry<K,V> newFirst = e.next;
2019	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
2020	<	newFirst = new HashEntry<K,V>(p.key, p.hash,
2021	<	newFirst, p.value);
2022	<	tab[index] = newFirst;
2023	<	count = c; // write-volatile
2009	>	/**
2010	>	* Returns a power of two table size for the given desired capacity.
2011	>	* See Hackers Delight, sec 3.2
2012	>	*/
2013	>	private static final int tableSizeFor(int c) {
2014	>	int n = c - 1;
2015	>	n |= n >>> 1;
2016	>	n |= n >>> 2;
2017	>	n |= n >>> 4;
2018	>	n |= n >>> 8;
2019	>	n |= n >>> 16;
2020	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
2021	>	}
2022	>
2023	>	/**
2024	>	* Initializes table, using the size recorded in sizeCtl.
2025	>	*/
2026	>	private final Node[] initTable() {
2027	>	Node[] tab; int sc;
2028	>	while ((tab = table) == null) {
2029	>	if ((sc = sizeCtl) < 0)
2030	>	Thread.yield(); // lost initialization race; just spin
2031	>	else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2032	>	try {
2033	>	if ((tab = table) == null) {
2034	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2035	>	tab = table = new Node[n];
2036	>	sc = n - (n >>> 2);
2037		}
2038	+	} finally {
2039	+	sizeCtl = sc;
2040	+	}
2041	+	break;
2042	+	}
2043	+	}
2044	+	return tab;
2045	+	}
2046	+
2047	+	/**
2048	+	* If table is too small and not already resizing, creates next
2049	+	* table and transfers bins.  Rechecks occupancy after a transfer
2050	+	* to see if another resize is already needed because resizings
2051	+	* are lagging additions.
2052	+	*/
2053	+	private final void checkForResize() {
2054	+	Node[] tab; int n, sc;
2055	+	while ((tab = table) != null &&
2056	+	(n = tab.length) < MAXIMUM_CAPACITY &&
2057	+	(sc = sizeCtl) >= 0 && counter.sum() >= (long)sc &&
2058	+	UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2059	+	try {
2060	+	if (tab == table) {
2061	+	table = rebuild(tab);
2062	+	sc = (n << 1) - (n >>> 1);
2063		}
538	–	return oldValue;
2064		} finally {
2065	<	unlock();
2065	>	sizeCtl = sc;
2066		}
2067		}
2068	+	}
2069
2070	<	void clear() {
2071	<	if (count != 0) {
2072	<	lock();
2070	>	/**
2071	>	* Tries to presize table to accommodate the given number of elements.
2072	>	*
2073	>	* @param size number of elements (doesn't need to be perfectly accurate)
2074	>	*/
2075	>	private final void tryPresize(int size) {
2076	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2077	>	tableSizeFor(size + (size >>> 1) + 1);
2078	>	int sc;
2079	>	while ((sc = sizeCtl) >= 0) {
2080	>	Node[] tab = table; int n;
2081	>	if (tab == null || (n = tab.length) == 0) {
2082	>	n = (sc > c) ? sc : c;
2083	>	if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2084	>	try {
2085	>	if (table == tab) {
2086	>	table = new Node[n];
2087	>	sc = n - (n >>> 2);
2088	>	}
2089	>	} finally {
2090	>	sizeCtl = sc;
2091	>	}
2092	>	}
2093	>	}
2094	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2095	>	break;
2096	>	else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2097		try {
2098	<	HashEntry<K,V>[] tab = table;
2099	<	for (int i = 0; i < tab.length ; i++)
2100	<	tab[i] = null;
2101	<	++modCount;
552	<	count = 0; // write-volatile
2098	>	if (table == tab) {
2099	>	table = rebuild(tab);
2100	>	sc = (n << 1) - (n >>> 1);
2101	>	}
2102		} finally {
2103	<	unlock();
2103	>	sizeCtl = sc;
2104	>	}
2105	>	}
2106	>	}
2107	>	}
2108	>
2109	>	/*
2110	>	* Moves and/or copies the nodes in each bin to new table. See
2111	>	* above for explanation.
2112	>	*
2113	>	* @return the new table
2114	>	*/
2115	>	private static final Node[] rebuild(Node[] tab) {
2116	>	int n = tab.length;
2117	>	Node[] nextTab = new Node[n << 1];
2118	>	Node fwd = new Node(MOVED, nextTab, null, null);
2119	>	int[] buffer = null;       // holds bins to revisit; null until needed
2120	>	Node rev = null;           // reverse forwarder; null until needed
2121	>	int nbuffered = 0;         // the number of bins in buffer list
2122	>	int bufferIndex = 0;       // buffer index of current buffered bin
2123	>	int bin = n - 1;           // current non-buffered bin or -1 if none
2124	>
2125	>	for (int i = bin;;) {      // start upwards sweep
2126	>	int fh; Node f;
2127	>	if ((f = tabAt(tab, i)) == null) {
2128	>	if (bin >= 0) {    // Unbuffered; no lock needed (or available)
2129	>	if (!casTabAt(tab, i, f, fwd))
2130	>	continue;
2131	>	}
2132	>	else {             // transiently use a locked forwarding node
2133	>	Node g = new Node(MOVED|LOCKED, nextTab, null, null);
2134	>	if (!casTabAt(tab, i, f, g))
2135	>	continue;
2136	>	setTabAt(nextTab, i, null);
2137	>	setTabAt(nextTab, i + n, null);
2138	>	setTabAt(tab, i, fwd);
2139	>	if (!g.casHash(MOVED|LOCKED, MOVED)) {
2140	>	g.hash = MOVED;
2141	>	synchronized (g) { g.notifyAll(); }
2142	>	}
2143	>	}
2144	>	}
2145	>	else if ((fh = f.hash) == MOVED) {
2146	>	Object fk = f.key;
2147	>	if (fk instanceof TreeBin) {
2148	>	TreeBin t = (TreeBin)fk;
2149	>	boolean validated = false;
2150	>	t.acquire(0);
2151	>	try {
2152	>	if (tabAt(tab, i) == f) {
2153	>	validated = true;
2154	>	splitTreeBin(nextTab, i, t);
2155	>	setTabAt(tab, i, fwd);
2156	>	}
2157	>	} finally {
2158	>	t.release(0);
2159	>	}
2160	>	if (!validated)
2161	>	continue;
2162	>	}
2163	>	}
2164	>	else if ((fh & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) {
2165	>	boolean validated = false;
2166	>	try {              // split to lo and hi lists; copying as needed
2167	>	if (tabAt(tab, i) == f) {
2168	>	validated = true;
2169	>	splitBin(nextTab, i, f);
2170	>	setTabAt(tab, i, fwd);
2171	>	}
2172	>	} finally {
2173	>	if (!f.casHash(fh | LOCKED, fh)) {
2174	>	f.hash = fh;
2175	>	synchronized (f) { f.notifyAll(); };
2176	>	}
2177	>	}
2178	>	if (!validated)
2179	>	continue;
2180	>	}
2181	>	else {
2182	>	if (buffer == null) // initialize buffer for revisits
2183	>	buffer = new int[TRANSFER_BUFFER_SIZE];
2184	>	if (bin < 0 && bufferIndex > 0) {
2185	>	int j = buffer[--bufferIndex];
2186	>	buffer[bufferIndex] = i;
2187	>	i = j;         // swap with another bin
2188	>	continue;
2189	>	}
2190	>	if (bin < 0 || nbuffered >= TRANSFER_BUFFER_SIZE) {
2191	>	f.tryAwaitLock(tab, i);
2192	>	continue;      // no other options -- block
2193		}
2194	+	if (rev == null)   // initialize reverse-forwarder
2195	+	rev = new Node(MOVED, tab, null, null);
2196	+	if (tabAt(tab, i) != f || (f.hash & LOCKED) == 0)
2197	+	continue;      // recheck before adding to list
2198	+	buffer[nbuffered++] = i;
2199	+	setTabAt(nextTab, i, rev);     // install place-holders
2200	+	setTabAt(nextTab, i + n, rev);
2201	+	}
2202	+
2203	+	if (bin > 0)
2204	+	i = --bin;
2205	+	else if (buffer != null && nbuffered > 0) {
2206	+	bin = -1;
2207	+	i = buffer[bufferIndex = --nbuffered];
2208		}
2209	+	else
2210	+	return nextTab;
2211		}
2212		}
2213
2214	+	/**
2215	+	* Splits a normal bin with list headed by e into lo and hi parts;
2216	+	* installs in given table.
2217	+	*/
2218	+	private static void splitBin(Node[] nextTab, int i, Node e) {
2219	+	int bit = nextTab.length >>> 1; // bit to split on
2220	+	int runBit = e.hash & bit;
2221	+	Node lastRun = e, lo = null, hi = null;
2222	+	for (Node p = e.next; p != null; p = p.next) {
2223	+	int b = p.hash & bit;
2224	+	if (b != runBit) {
2225	+	runBit = b;
2226	+	lastRun = p;
2227	+	}
2228	+	}
2229	+	if (runBit == 0)
2230	+	lo = lastRun;
2231	+	else
2232	+	hi = lastRun;
2233	+	for (Node p = e; p != lastRun; p = p.next) {
2234	+	int ph = p.hash & HASH_BITS;
2235	+	Object pk = p.key, pv = p.val;
2236	+	if ((ph & bit) == 0)
2237	+	lo = new Node(ph, pk, pv, lo);
2238	+	else
2239	+	hi = new Node(ph, pk, pv, hi);
2240	+	}
2241	+	setTabAt(nextTab, i, lo);
2242	+	setTabAt(nextTab, i + bit, hi);
2243	+	}
2244
2245	+	/**
2246	+	* Splits a tree bin into lo and hi parts; installs in given table.
2247	+	*/
2248	+	private static void splitTreeBin(Node[] nextTab, int i, TreeBin t) {
2249	+	int bit = nextTab.length >>> 1;
2250	+	TreeBin lt = new TreeBin();
2251	+	TreeBin ht = new TreeBin();
2252	+	int lc = 0, hc = 0;
2253	+	for (Node e = t.first; e != null; e = e.next) {
2254	+	int h = e.hash & HASH_BITS;
2255	+	Object k = e.key, v = e.val;
2256	+	if ((h & bit) == 0) {
2257	+	++lc;
2258	+	lt.putTreeNode(h, k, v);
2259	+	}
2260	+	else {
2261	+	++hc;
2262	+	ht.putTreeNode(h, k, v);
2263	+	}
2264	+	}
2265	+	Node ln, hn; // throw away trees if too small
2266	+	if (lc <= (TREE_THRESHOLD >>> 1)) {
2267	+	ln = null;
2268	+	for (Node p = lt.first; p != null; p = p.next)
2269	+	ln = new Node(p.hash, p.key, p.val, ln);
2270	+	}
2271	+	else
2272	+	ln = new Node(MOVED, lt, null, null);
2273	+	setTabAt(nextTab, i, ln);
2274	+	if (hc <= (TREE_THRESHOLD >>> 1)) {
2275	+	hn = null;
2276	+	for (Node p = ht.first; p != null; p = p.next)
2277	+	hn = new Node(p.hash, p.key, p.val, hn);
2278	+	}
2279	+	else
2280	+	hn = new Node(MOVED, ht, null, null);
2281	+	setTabAt(nextTab, i + bit, hn);
2282	+	}
2283
2284	<	/* ---------------- Public operations -------------- */
2284	>	/**
2285	>	* Implementation for clear. Steps through each bin, removing all
2286	>	* nodes.
2287	>	*/
2288	>	private final void internalClear() {
2289	>	long delta = 0L; // negative number of deletions
2290	>	int i = 0;
2291	>	Node[] tab = table;
2292	>	while (tab != null && i < tab.length) {
2293	>	int fh; Object fk;
2294	>	Node f = tabAt(tab, i);
2295	>	if (f == null)
2296	>	++i;
2297	>	else if ((fh = f.hash) == MOVED) {
2298	>	if ((fk = f.key) instanceof TreeBin) {
2299	>	TreeBin t = (TreeBin)fk;
2300	>	t.acquire(0);
2301	>	try {
2302	>	if (tabAt(tab, i) == f) {
2303	>	for (Node p = t.first; p != null; p = p.next) {
2304	>	if (p.val != null) { // (currently always true)
2305	>	p.val = null;
2306	>	--delta;
2307	>	}
2308	>	}
2309	>	t.first = null;
2310	>	t.root = null;
2311	>	++i;
2312	>	}
2313	>	} finally {
2314	>	t.release(0);
2315	>	}
2316	>	}
2317	>	else
2318	>	tab = (Node[])fk;
2319	>	}
2320	>	else if ((fh & LOCKED) != 0) {
2321	>	counter.add(delta); // opportunistically update count
2322	>	delta = 0L;
2323	>	f.tryAwaitLock(tab, i);
2324	>	}
2325	>	else if (f.casHash(fh, fh | LOCKED)) {
2326	>	try {
2327	>	if (tabAt(tab, i) == f) {
2328	>	for (Node e = f; e != null; e = e.next) {
2329	>	if (e.val != null) {  // (currently always true)
2330	>	e.val = null;
2331	>	--delta;
2332	>	}
2333	>	}
2334	>	setTabAt(tab, i, null);
2335	>	++i;
2336	>	}
2337	>	} finally {
2338	>	if (!f.casHash(fh | LOCKED, fh)) {
2339	>	f.hash = fh;
2340	>	synchronized (f) { f.notifyAll(); };
2341	>	}
2342	>	}
2343	>	}
2344	>	}
2345	>	if (delta != 0)
2346	>	counter.add(delta);
2347	>	}
2348	>
2349	>	/* ----------------Table Traversal -------------- */
2350
2351		/**
2352	<	* Creates a new, empty map with the specified initial
2353	<	* capacity, load factor and concurrency level.
2352	>	* Encapsulates traversal for methods such as containsValue; also
2353	>	* serves as a base class for other iterators and bulk tasks.
2354		*
2355	<	* @param initialCapacity the initial capacity. The implementation
2356	<	* performs internal sizing to accommodate this many elements.
2357	<	* @param loadFactor  the load factor threshold, used to control resizing.
2358	<	* Resizing may be performed when the average number of elements per
2359	<	* bin exceeds this threshold.
2360	<	* @param concurrencyLevel the estimated number of concurrently
2361	<	* updating threads. The implementation performs internal sizing
2362	<	* to try to accommodate this many threads.
2363	<	* @throws IllegalArgumentException if the initial capacity is
2364	<	* negative or the load factor or concurrencyLevel are
2365	<	* nonpositive.
2366	<	*/
2367	<	public ConcurrentHashMap(int initialCapacity,
2368	<	float loadFactor, int concurrencyLevel) {
2369	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2370	<	throw new IllegalArgumentException();
2355	>	* At each step, the iterator snapshots the key ("nextKey") and
2356	>	* value ("nextVal") of a valid node (i.e., one that, at point of
2357	>	* snapshot, has a non-null user value). Because val fields can
2358	>	* change (including to null, indicating deletion), field nextVal
2359	>	* might not be accurate at point of use, but still maintains the
2360	>	* weak consistency property of holding a value that was once
2361	>	* valid. To support iterator.remove, the nextKey field is not
2362	>	* updated (nulled out) when the iterator cannot advance.
2363	>	*
2364	>	* Internal traversals directly access these fields, as in:
2365	>	* {@code while (it.advance() != null) { process(it.nextKey); }}
2366	>	*
2367	>	* Exported iterators must track whether the iterator has advanced
2368	>	* (in hasNext vs next) (by setting/checking/nulling field
2369	>	* nextVal), and then extract key, value, or key-value pairs as
2370	>	* return values of next().
2371	>	*
2372	>	* The iterator visits once each still-valid node that was
2373	>	* reachable upon iterator construction. It might miss some that
2374	>	* were added to a bin after the bin was visited, which is OK wrt
2375	>	* consistency guarantees. Maintaining this property in the face
2376	>	* of possible ongoing resizes requires a fair amount of
2377	>	* bookkeeping state that is difficult to optimize away amidst
2378	>	* volatile accesses.  Even so, traversal maintains reasonable
2379	>	* throughput.
2380	>	*
2381	>	* Normally, iteration proceeds bin-by-bin traversing lists.
2382	>	* However, if the table has been resized, then all future steps
2383	>	* must traverse both the bin at the current index as well as at
2384	>	* (index + baseSize); and so on for further resizings. To
2385	>	* paranoically cope with potential sharing by users of iterators
2386	>	* across threads, iteration terminates if a bounds checks fails
2387	>	* for a table read.
2388	>	*
2389	>	* This class extends ForkJoinTask to streamline parallel
2390	>	* iteration in bulk operations (see BulkTask). This adds only an
2391	>	* int of space overhead, which is close enough to negligible in
2392	>	* cases where it is not needed to not worry about it.  Because
2393	>	* ForkJoinTask is Serializable, but iterators need not be, we
2394	>	* need to add warning suppressions.
2395	>	*/
2396	>	@SuppressWarnings("serial") static class Traverser<K,V,R> extends ForkJoinTask<R> {
2397	>	final ConcurrentHashMap<K, V> map;
2398	>	Node next;           // the next entry to use
2399	>	Object nextKey;      // cached key field of next
2400	>	Object nextVal;      // cached val field of next
2401	>	Node[] tab;          // current table; updated if resized
2402	>	int index;           // index of bin to use next
2403	>	int baseIndex;       // current index of initial table
2404	>	int baseLimit;       // index bound for initial table
2405	>	int baseSize;        // initial table size
2406	>
2407	>	/** Creates iterator for all entries in the table. */
2408	>	Traverser(ConcurrentHashMap<K, V> map) {
2409	>	this.map = map;
2410	>	}
2411	>
2412	>	/** Creates iterator for split() methods */
2413	>	Traverser(Traverser<K,V,?> it) {
2414	>	ConcurrentHashMap<K, V> m; Node[] t;
2415	>	if ((m = this.map = it.map) == null)
2416	>	t = null;
2417	>	else if ((t = it.tab) == null && // force parent tab initialization
2418	>	(t = it.tab = m.table) != null)
2419	>	it.baseLimit = it.baseSize = t.length;
2420	>	this.tab = t;
2421	>	this.baseSize = it.baseSize;
2422	>	it.baseLimit = this.index = this.baseIndex =
2423	>	((this.baseLimit = it.baseLimit) + it.baseIndex + 1) >>> 1;
2424	>	}
2425
2426	<	if (concurrencyLevel > MAX_SEGMENTS)
2427	<	concurrencyLevel = MAX_SEGMENTS;
2426	>	/**
2427	>	* Advances next; returns nextVal or null if terminated.
2428	>	* See above for explanation.
2429	>	*/
2430	>	final Object advance() {
2431	>	Node e = next;
2432	>	Object ev = null;
2433	>	outer: do {
2434	>	if (e != null)                  // advance past used/skipped node
2435	>	e = e.next;
2436	>	while (e == null) {             // get to next non-null bin
2437	>	ConcurrentHashMap<K, V> m;
2438	>	Node[] t; int b, i, n; Object ek; // checks must use locals
2439	>	if ((t = tab) != null)
2440	>	n = t.length;
2441	>	else if ((m = map) != null && (t = tab = m.table) != null)
2442	>	n = baseLimit = baseSize = t.length;
2443	>	else
2444	>	break outer;
2445	>	if ((b = baseIndex) >= baseLimit ||
2446	>	(i = index) < 0 || i >= n)
2447	>	break outer;
2448	>	if ((e = tabAt(t, i)) != null && e.hash == MOVED) {
2449	>	if ((ek = e.key) instanceof TreeBin)
2450	>	e = ((TreeBin)ek).first;
2451	>	else {
2452	>	tab = (Node[])ek;
2453	>	continue;           // restarts due to null val
2454	>	}
2455	>	}                           // visit upper slots if present
2456	>	index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2457	>	}
2458	>	nextKey = e.key;
2459	>	} while ((ev = e.val) == null);    // skip deleted or special nodes
2460	>	next = e;
2461	>	return nextVal = ev;
2462	>	}
2463
2464	<	// Find power-of-two sizes best matching arguments
2465	<	int sshift = 0;
2466	<	int ssize = 1;
2467	<	while (ssize < concurrencyLevel) {
2468	<	++sshift;
2469	<	ssize <<= 1;
2470	<	}
2471	<	segmentShift = 32 - sshift;
2472	<	segmentMask = ssize - 1;
2473	<	this.segments = Segment.newArray(ssize);
2474	<
2475	<	if (initialCapacity > MAXIMUM_CAPACITY)
2476	<	initialCapacity = MAXIMUM_CAPACITY;
2477	<	int c = initialCapacity / ssize;
2478	<	if (c * ssize < initialCapacity)
2479	<	++c;
2480	<	int cap = 1;
2481	<	while (cap < c)
606	<	cap <<= 1;
2464	>	public final void remove() {
2465	>	Object k = nextKey;
2466	>	if (k == null && (advance() == null || (k = nextKey) == null))
2467	>	throw new IllegalStateException();
2468	>	map.internalReplace(k, null, null);
2469	>	}
2470	>
2471	>	public final boolean hasNext() {
2472	>	return nextVal != null || advance() != null;
2473	>	}
2474	>
2475	>	public final boolean hasMoreElements() { return hasNext(); }
2476	>	public final void setRawResult(Object x) { }
2477	>	public R getRawResult() { return null; }
2478	>	public boolean exec() { return true; }
2479	>	}
2480	>
2481	>	/* ---------------- Public operations -------------- */
2482
2483	<	for (int i = 0; i < this.segments.length; ++i)
2484	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2483	>	/**
2484	>	* Creates a new, empty map with the default initial table size (16).
2485	>	*/
2486	>	public ConcurrentHashMap() {
2487	>	this.counter = new LongAdder();
2488		}
2489
2490		/**
2491	<	* Creates a new, empty map with the specified initial capacity
2492	<	* and load factor and with the default concurrencyLevel (16).
2491	>	* Creates a new, empty map with an initial table size
2492	>	* accommodating the specified number of elements without the need
2493	>	* to dynamically resize.
2494		*
2495		* @param initialCapacity The implementation performs internal
2496		* sizing to accommodate this many elements.
2497	<	* @param loadFactor  the load factor threshold, used to control resizing.
2498	<	* Resizing may be performed when the average number of elements per
2499	<	* bin exceeds this threshold.
2497	>	* @throws IllegalArgumentException if the initial capacity of
2498	>	* elements is negative
2499	>	*/
2500	>	public ConcurrentHashMap(int initialCapacity) {
2501	>	if (initialCapacity < 0)
2502	>	throw new IllegalArgumentException();
2503	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2504	>	MAXIMUM_CAPACITY :
2505	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2506	>	this.counter = new LongAdder();
2507	>	this.sizeCtl = cap;
2508	>	}
2509	>
2510	>	/**
2511	>	* Creates a new map with the same mappings as the given map.
2512	>	*
2513	>	* @param m the map
2514	>	*/
2515	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2516	>	this.counter = new LongAdder();
2517	>	this.sizeCtl = DEFAULT_CAPACITY;
2518	>	internalPutAll(m);
2519	>	}
2520	>
2521	>	/**
2522	>	* Creates a new, empty map with an initial table size based on
2523	>	* the given number of elements ({@code initialCapacity}) and
2524	>	* initial table density ({@code loadFactor}).
2525	>	*
2526	>	* @param initialCapacity the initial capacity. The implementation
2527	>	* performs internal sizing to accommodate this many elements,
2528	>	* given the specified load factor.
2529	>	* @param loadFactor the load factor (table density) for
2530	>	* establishing the initial table size
2531		* @throws IllegalArgumentException if the initial capacity of
2532		* elements is negative or the load factor is nonpositive
2533		*
2534		* @since 1.6
2535		*/
2536		public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2537	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
2537	>	this(initialCapacity, loadFactor, 1);
2538		}
2539
2540		/**
2541	<	* Creates a new, empty map with the specified initial capacity,
2542	<	* and with default load factor (0.75) and concurrencyLevel (16).
2541	>	* Creates a new, empty map with an initial table size based on
2542	>	* the given number of elements ({@code initialCapacity}), table
2543	>	* density ({@code loadFactor}), and number of concurrently
2544	>	* updating threads ({@code concurrencyLevel}).
2545		*
2546		* @param initialCapacity the initial capacity. The implementation
2547	<	* performs internal sizing to accommodate this many elements.
2548	<	* @throws IllegalArgumentException if the initial capacity of
2549	<	* elements is negative.
2547	>	* performs internal sizing to accommodate this many elements,
2548	>	* given the specified load factor.
2549	>	* @param loadFactor the load factor (table density) for
2550	>	* establishing the initial table size
2551	>	* @param concurrencyLevel the estimated number of concurrently
2552	>	* updating threads. The implementation may use this value as
2553	>	* a sizing hint.
2554	>	* @throws IllegalArgumentException if the initial capacity is
2555	>	* negative or the load factor or concurrencyLevel are
2556	>	* nonpositive
2557		*/
2558	<	public ConcurrentHashMap(int initialCapacity) {
2559	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2558	>	public ConcurrentHashMap(int initialCapacity,
2559	>	float loadFactor, int concurrencyLevel) {
2560	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2561	>	throw new IllegalArgumentException();
2562	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2563	>	initialCapacity = concurrencyLevel;   // as estimated threads
2564	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2565	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2566	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2567	>	this.counter = new LongAdder();
2568	>	this.sizeCtl = cap;
2569		}
2570
2571		/**
2572	<	* Creates a new, empty map with a default initial capacity (16),
2573	<	* load factor (0.75) and concurrencyLevel (16).
2572	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2573	>	* from the given type to {@code Boolean.TRUE}.
2574	>	*
2575	>	* @return the new set
2576		*/
2577	<	public ConcurrentHashMap() {
2578	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2577	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2578	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(),
2579	>	Boolean.TRUE);
2580		}
2581
2582		/**
2583	<	* Creates a new map with the same mappings as the given map.
2584	<	* The map is created with a capacity of 1.5 times the number
654	<	* of mappings in the given map or 16 (whichever is greater),
655	<	* and a default load factor (0.75) and concurrencyLevel (16).
2583	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2584	>	* from the given type to {@code Boolean.TRUE}.
2585		*
2586	<	* @param m the map
2586	>	* @param initialCapacity The implementation performs internal
2587	>	* sizing to accommodate this many elements.
2588	>	* @throws IllegalArgumentException if the initial capacity of
2589	>	* elements is negative
2590	>	* @return the new set
2591		*/
2592	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2593	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
2594	<	DEFAULT_INITIAL_CAPACITY),
662	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
663	<	putAll(m);
2592	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2593	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(initialCapacity),
2594	>	Boolean.TRUE);
2595		}
2596
2597		/**
2598	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
668	<	*
669	<	* @return <tt>true</tt> if this map contains no key-value mappings
2598	>	* {@inheritDoc}
2599		*/
2600		public boolean isEmpty() {
2601	<	final Segment<K,V>[] segments = this.segments;
673	<	/*
674	<	* We keep track of per-segment modCounts to avoid ABA
675	<	* problems in which an element in one segment was added and
676	<	* in another removed during traversal, in which case the
677	<	* table was never actually empty at any point. Note the
678	<	* similar use of modCounts in the size() and containsValue()
679	<	* methods, which are the only other methods also susceptible
680	<	* to ABA problems.
681	<	*/
682	<	int[] mc = new int[segments.length];
683	<	int mcsum = 0;
684	<	for (int i = 0; i < segments.length; ++i) {
685	<	if (segments[i].count != 0)
686	<	return false;
687	<	else
688	<	mcsum += mc[i] = segments[i].modCount;
689	<	}
690	<	// If mcsum happens to be zero, then we know we got a snapshot
691	<	// before any modifications at all were made.  This is
692	<	// probably common enough to bother tracking.
693	<	if (mcsum != 0) {
694	<	for (int i = 0; i < segments.length; ++i) {
695	<	if (segments[i].count != 0 ||
696	<	mc[i] != segments[i].modCount)
697	<	return false;
698	<	}
699	<	}
700	<	return true;
2601	>	return counter.sum() <= 0L; // ignore transient negative values
2602		}
2603
2604		/**
2605	<	* Returns the number of key-value mappings in this map.  If the
705	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
706	<	* <tt>Integer.MAX_VALUE</tt>.
707	<	*
708	<	* @return the number of key-value mappings in this map
2605	>	* {@inheritDoc}
2606		*/
2607		public int size() {
2608	<	final Segment<K,V>[] segments = this.segments;
2609	<	long sum = 0;
2610	<	long check = 0;
2611	<	int[] mc = new int[segments.length];
2612	<	// Try a few times to get accurate count. On failure due to
2613	<	// continuous async changes in table, resort to locking.
2614	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
2615	<	check = 0;
2616	<	sum = 0;
2617	<	int mcsum = 0;
2618	<	for (int i = 0; i < segments.length; ++i) {
2619	<	sum += segments[i].count;
2620	<	mcsum += mc[i] = segments[i].modCount;
2621	<	}
2622	<	if (mcsum != 0) {
2623	<	for (int i = 0; i < segments.length; ++i) {
2624	<	check += segments[i].count;
2625	<	if (mc[i] != segments[i].modCount) {
729	<	check = -1; // force retry
730	<	break;
731	<	}
732	<	}
733	<	}
734	<	if (check == sum)
735	<	break;
736	<	}
737	<	if (check != sum) { // Resort to locking all segments
738	<	sum = 0;
739	<	for (int i = 0; i < segments.length; ++i)
740	<	segments[i].lock();
741	<	for (int i = 0; i < segments.length; ++i)
742	<	sum += segments[i].count;
743	<	for (int i = 0; i < segments.length; ++i)
744	<	segments[i].unlock();
745	<	}
746	<	if (sum > Integer.MAX_VALUE)
747	<	return Integer.MAX_VALUE;
748	<	else
749	<	return (int)sum;
2608	>	long n = counter.sum();
2609	>	return ((n < 0L) ? 0 :
2610	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2611	>	(int)n);
2612	>	}
2613	>
2614	>	/**
2615	>	* Returns the number of mappings. This method should be used
2616	>	* instead of {@link #size} because a ConcurrentHashMap may
2617	>	* contain more mappings than can be represented as an int. The
2618	>	* value returned is a snapshot; the actual count may differ if
2619	>	* there are ongoing concurrent insertions or removals.
2620	>	*
2621	>	* @return the number of mappings
2622	>	*/
2623	>	public long mappingCount() {
2624	>	long n = counter.sum();
2625	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2626		}
2627
2628		/**
2629	<	* Returns the value to which this map maps the specified key, or
2630	<	* <tt>null</tt> if the map contains no mapping for the key.
2629	>	* Returns the value to which the specified key is mapped,
2630	>	* or {@code null} if this map contains no mapping for the key.
2631	>	*
2632	>	* <p>More formally, if this map contains a mapping from a key
2633	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
2634	>	* then this method returns {@code v}; otherwise it returns
2635	>	* {@code null}.  (There can be at most one such mapping.)
2636		*
756	–	* @param key key whose associated value is to be returned
757	–	* @return the value to which this map maps the specified key, or
758	–	*         <tt>null</tt> if the map contains no mapping for the key
2637		* @throws NullPointerException if the specified key is null
2638		*/
2639	<	public V get(Object key) {
2640	<	int hash = hash(key); // throws NullPointerException if key null
2641	<	return segmentFor(hash).get(key, hash);
2639	>	@SuppressWarnings("unchecked") public V get(Object key) {
2640	>	if (key == null)
2641	>	throw new NullPointerException();
2642	>	return (V)internalGet(key);
2643	>	}
2644	>
2645	>	/**
2646	>	* Returns the value to which the specified key is mapped,
2647	>	* or the given defaultValue if this map contains no mapping for the key.
2648	>	*
2649	>	* @param key the key
2650	>	* @param defaultValue the value to return if this map contains
2651	>	* no mapping for the given key
2652	>	* @return the mapping for the key, if present; else the defaultValue
2653	>	* @throws NullPointerException if the specified key is null
2654	>	*/
2655	>	@SuppressWarnings("unchecked") public V getValueOrDefault(Object key, V defaultValue) {
2656	>	if (key == null)
2657	>	throw new NullPointerException();
2658	>	V v = (V) internalGet(key);
2659	>	return v == null ? defaultValue : v;
2660		}
2661
2662		/**
2663		* Tests if the specified object is a key in this table.
2664		*
2665		* @param  key   possible key
2666	<	* @return <tt>true</tt> if and only if the specified object
2666	>	* @return {@code true} if and only if the specified object
2667		*         is a key in this table, as determined by the
2668	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
2668	>	*         {@code equals} method; {@code false} otherwise
2669		* @throws NullPointerException if the specified key is null
2670		*/
2671		public boolean containsKey(Object key) {
2672	<	int hash = hash(key); // throws NullPointerException if key null
2673	<	return segmentFor(hash).containsKey(key, hash);
2672	>	if (key == null)
2673	>	throw new NullPointerException();
2674	>	return internalGet(key) != null;
2675		}
2676
2677		/**
2678	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2679	<	* specified value. Note: This method requires a full internal
2680	<	* traversal of the hash table, and so is much slower than
784	<	* method <tt>containsKey</tt>.
2678	>	* Returns {@code true} if this map maps one or more keys to the
2679	>	* specified value. Note: This method may require a full traversal
2680	>	* of the map, and is much slower than method {@code containsKey}.
2681		*
2682		* @param value value whose presence in this map is to be tested
2683	<	* @return <tt>true</tt> if this map maps one or more keys to the
2683	>	* @return {@code true} if this map maps one or more keys to the
2684		*         specified value
2685		* @throws NullPointerException if the specified value is null
2686		*/
2687		public boolean containsValue(Object value) {
2688		if (value == null)
2689		throw new NullPointerException();
2690	<
2691	<	// See explanation of modCount use above
2692	<
2693	<	final Segment<K,V>[] segments = this.segments;
2694	<	int[] mc = new int[segments.length];
799	<
800	<	// Try a few times without locking
801	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
802	<	int sum = 0;
803	<	int mcsum = 0;
804	<	for (int i = 0; i < segments.length; ++i) {
805	<	int c = segments[i].count;
806	<	mcsum += mc[i] = segments[i].modCount;
807	<	if (segments[i].containsValue(value))
808	<	return true;
809	<	}
810	<	boolean cleanSweep = true;
811	<	if (mcsum != 0) {
812	<	for (int i = 0; i < segments.length; ++i) {
813	<	int c = segments[i].count;
814	<	if (mc[i] != segments[i].modCount) {
815	<	cleanSweep = false;
816	<	break;
817	<	}
818	<	}
819	<	}
820	<	if (cleanSweep)
821	<	return false;
2690	>	Object v;
2691	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2692	>	while ((v = it.advance()) != null) {
2693	>	if (v == value || value.equals(v))
2694	>	return true;
2695		}
2696	<	// Resort to locking all segments
824	<	for (int i = 0; i < segments.length; ++i)
825	<	segments[i].lock();
826	<	boolean found = false;
827	<	try {
828	<	for (int i = 0; i < segments.length; ++i) {
829	<	if (segments[i].containsValue(value)) {
830	<	found = true;
831	<	break;
832	<	}
833	<	}
834	<	} finally {
835	<	for (int i = 0; i < segments.length; ++i)
836	<	segments[i].unlock();
837	<	}
838	<	return found;
2696	>	return false;
2697		}
2698
2699		/**
#	Line 845 | Line 2703 | public class ConcurrentHashMap<K, V> ext
2703		* full compatibility with class {@link java.util.Hashtable},
2704		* which supported this method prior to introduction of the
2705		* Java Collections framework.
2706	<
2706	>	*
2707		* @param  value a value to search for
2708	<	* @return <tt>true</tt> if and only if some key maps to the
2709	<	*         <tt>value</tt> argument in this table as
2710	<	*         determined by the <tt>equals</tt> method;
2711	<	*         <tt>false</tt> otherwise
2708	>	* @return {@code true} if and only if some key maps to the
2709	>	*         {@code value} argument in this table as
2710	>	*         determined by the {@code equals} method;
2711	>	*         {@code false} otherwise
2712		* @throws NullPointerException if the specified value is null
2713		*/
2714		public boolean contains(Object value) {
#	Line 861 | Line 2719 | public class ConcurrentHashMap<K, V> ext
2719		* Maps the specified key to the specified value in this table.
2720		* Neither the key nor the value can be null.
2721		*
2722	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
2722	>	* <p> The value can be retrieved by calling the {@code get} method
2723		* with a key that is equal to the original key.
2724		*
2725		* @param key key with which the specified value is to be associated
2726		* @param value value to be associated with the specified key
2727	<	* @return the previous value associated with <tt>key</tt>, or
2728	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2727	>	* @return the previous value associated with {@code key}, or
2728	>	*         {@code null} if there was no mapping for {@code key}
2729		* @throws NullPointerException if the specified key or value is null
2730		*/
2731	<	public V put(K key, V value) {
2732	<	if (value == null)
2731	>	@SuppressWarnings("unchecked") public V put(K key, V value) {
2732	>	if (key == null || value == null)
2733		throw new NullPointerException();
2734	<	int hash = hash(key);
877	<	return segmentFor(hash).put(key, hash, value, false);
2734	>	return (V)internalPut(key, value);
2735		}
2736
2737		/**
2738		* {@inheritDoc}
2739		*
2740		* @return the previous value associated with the specified key,
2741	<	*         or <tt>null</tt> if there was no mapping for the key
2741	>	*         or {@code null} if there was no mapping for the key
2742		* @throws NullPointerException if the specified key or value is null
2743		*/
2744	<	public V putIfAbsent(K key, V value) {
2745	<	if (value == null)
2744	>	@SuppressWarnings("unchecked") public V putIfAbsent(K key, V value) {
2745	>	if (key == null || value == null)
2746		throw new NullPointerException();
2747	<	int hash = hash(key);
891	<	return segmentFor(hash).put(key, hash, value, true);
2747	>	return (V)internalPutIfAbsent(key, value);
2748		}
2749
2750		/**
#	Line 899 | Line 2755 | public class ConcurrentHashMap<K, V> ext
2755		* @param m mappings to be stored in this map
2756		*/
2757		public void putAll(Map<? extends K, ? extends V> m) {
2758	<	for (Iterator<? extends Map.Entry<? extends K, ? extends V>> it = (Iterator<? extends Map.Entry<? extends K, ? extends V>>) m.entrySet().iterator(); it.hasNext(); ) {
2759	<	Entry<? extends K, ? extends V> e = it.next();
2760	<	put(e.getKey(), e.getValue());
2761	<	}
2758	>	internalPutAll(m);
2759	>	}
2760	>
2761	>	/**
2762	>	* If the specified key is not already associated with a value,
2763	>	* computes its value using the given mappingFunction and enters
2764	>	* it into the map unless null.  This is equivalent to
2765	>	* <pre> {@code
2766	>	* if (map.containsKey(key))
2767	>	*   return map.get(key);
2768	>	* value = mappingFunction.apply(key);
2769	>	* if (value != null)
2770	>	*   map.put(key, value);
2771	>	* return value;}</pre>
2772	>	*
2773	>	* except that the action is performed atomically.  If the
2774	>	* function returns {@code null} no mapping is recorded. If the
2775	>	* function itself throws an (unchecked) exception, the exception
2776	>	* is rethrown to its caller, and no mapping is recorded.  Some
2777	>	* attempted update operations on this map by other threads may be
2778	>	* blocked while computation is in progress, so the computation
2779	>	* should be short and simple, and must not attempt to update any
2780	>	* other mappings of this Map. The most appropriate usage is to
2781	>	* construct a new object serving as an initial mapped value, or
2782	>	* memoized result, as in:
2783	>	*
2784	>	*  <pre> {@code
2785	>	* map.computeIfAbsent(key, new Fun<K, V>() {
2786	>	*   public V map(K k) { return new Value(f(k)); }});}</pre>
2787	>	*
2788	>	* @param key key with which the specified value is to be associated
2789	>	* @param mappingFunction the function to compute a value
2790	>	* @return the current (existing or computed) value associated with
2791	>	*         the specified key, or null if the computed value is null
2792	>	* @throws NullPointerException if the specified key or mappingFunction
2793	>	*         is null
2794	>	* @throws IllegalStateException if the computation detectably
2795	>	*         attempts a recursive update to this map that would
2796	>	*         otherwise never complete
2797	>	* @throws RuntimeException or Error if the mappingFunction does so,
2798	>	*         in which case the mapping is left unestablished
2799	>	*/
2800	>	@SuppressWarnings("unchecked") public V computeIfAbsent
2801	>	(K key, Fun<? super K, ? extends V> mappingFunction) {
2802	>	if (key == null || mappingFunction == null)
2803	>	throw new NullPointerException();
2804	>	return (V)internalComputeIfAbsent(key, mappingFunction);
2805	>	}
2806	>
2807	>	/**
2808	>	* If the given key is present, computes a new mapping value given a key and
2809	>	* its current mapped value. This is equivalent to
2810	>	*  <pre> {@code
2811	>	*   if (map.containsKey(key)) {
2812	>	*     value = remappingFunction.apply(key, map.get(key));
2813	>	*     if (value != null)
2814	>	*       map.put(key, value);
2815	>	*     else
2816	>	*       map.remove(key);
2817	>	*   }
2818	>	* }</pre>
2819	>	*
2820	>	* except that the action is performed atomically.  If the
2821	>	* function returns {@code null}, the mapping is removed.  If the
2822	>	* function itself throws an (unchecked) exception, the exception
2823	>	* is rethrown to its caller, and the current mapping is left
2824	>	* unchanged.  Some attempted update operations on this map by
2825	>	* other threads may be blocked while computation is in progress,
2826	>	* so the computation should be short and simple, and must not
2827	>	* attempt to update any other mappings of this Map. For example,
2828	>	* to either create or append new messages to a value mapping:
2829	>	*
2830	>	* @param key key with which the specified value is to be associated
2831	>	* @param remappingFunction the function to compute a value
2832	>	* @return the new value associated with the specified key, or null if none
2833	>	* @throws NullPointerException if the specified key or remappingFunction
2834	>	*         is null
2835	>	* @throws IllegalStateException if the computation detectably
2836	>	*         attempts a recursive update to this map that would
2837	>	*         otherwise never complete
2838	>	* @throws RuntimeException or Error if the remappingFunction does so,
2839	>	*         in which case the mapping is unchanged
2840	>	*/
2841	>	@SuppressWarnings("unchecked") public V computeIfPresent
2842	>	(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2843	>	if (key == null || remappingFunction == null)
2844	>	throw new NullPointerException();
2845	>	return (V)internalCompute(key, true, remappingFunction);
2846	>	}
2847	>
2848	>	/**
2849	>	* Computes a new mapping value given a key and
2850	>	* its current mapped value (or {@code null} if there is no current
2851	>	* mapping). This is equivalent to
2852	>	*  <pre> {@code
2853	>	*   value = remappingFunction.apply(key, map.get(key));
2854	>	*   if (value != null)
2855	>	*     map.put(key, value);
2856	>	*   else
2857	>	*     map.remove(key);
2858	>	* }</pre>
2859	>	*
2860	>	* except that the action is performed atomically.  If the
2861	>	* function returns {@code null}, the mapping is removed.  If the
2862	>	* function itself throws an (unchecked) exception, the exception
2863	>	* is rethrown to its caller, and the current mapping is left
2864	>	* unchanged.  Some attempted update operations on this map by
2865	>	* other threads may be blocked while computation is in progress,
2866	>	* so the computation should be short and simple, and must not
2867	>	* attempt to update any other mappings of this Map. For example,
2868	>	* to either create or append new messages to a value mapping:
2869	>	*
2870	>	* <pre> {@code
2871	>	* Map<Key, String> map = ...;
2872	>	* final String msg = ...;
2873	>	* map.compute(key, new BiFun<Key, String, String>() {
2874	>	*   public String apply(Key k, String v) {
2875	>	*    return (v == null) ? msg : v + msg;});}}</pre>
2876	>	*
2877	>	* @param key key with which the specified value is to be associated
2878	>	* @param remappingFunction the function to compute a value
2879	>	* @return the new value associated with the specified key, or null if none
2880	>	* @throws NullPointerException if the specified key or remappingFunction
2881	>	*         is null
2882	>	* @throws IllegalStateException if the computation detectably
2883	>	*         attempts a recursive update to this map that would
2884	>	*         otherwise never complete
2885	>	* @throws RuntimeException or Error if the remappingFunction does so,
2886	>	*         in which case the mapping is unchanged
2887	>	*/
2888	>	@SuppressWarnings("unchecked") public V compute
2889	>	(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2890	>	if (key == null || remappingFunction == null)
2891	>	throw new NullPointerException();
2892	>	return (V)internalCompute(key, false, remappingFunction);
2893	>	}
2894	>
2895	>	/**
2896	>	* If the specified key is not already associated
2897	>	* with a value, associate it with the given value.
2898	>	* Otherwise, replace the value with the results of
2899	>	* the given remapping function. This is equivalent to:
2900	>	*  <pre> {@code
2901	>	*   if (!map.containsKey(key))
2902	>	*     map.put(value);
2903	>	*   else {
2904	>	*     newValue = remappingFunction.apply(map.get(key), value);
2905	>	*     if (value != null)
2906	>	*       map.put(key, value);
2907	>	*     else
2908	>	*       map.remove(key);
2909	>	*   }
2910	>	* }</pre>
2911	>	* except that the action is performed atomically.  If the
2912	>	* function returns {@code null}, the mapping is removed.  If the
2913	>	* function itself throws an (unchecked) exception, the exception
2914	>	* is rethrown to its caller, and the current mapping is left
2915	>	* unchanged.  Some attempted update operations on this map by
2916	>	* other threads may be blocked while computation is in progress,
2917	>	* so the computation should be short and simple, and must not
2918	>	* attempt to update any other mappings of this Map.
2919	>	*/
2920	>	@SuppressWarnings("unchecked") public V merge
2921	>	(K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
2922	>	if (key == null || value == null || remappingFunction == null)
2923	>	throw new NullPointerException();
2924	>	return (V)internalMerge(key, value, remappingFunction);
2925		}
2926
2927		/**
#	Line 910 | Line 2929 | public class ConcurrentHashMap<K, V> ext
2929		* This method does nothing if the key is not in the map.
2930		*
2931		* @param  key the key that needs to be removed
2932	<	* @return the previous value associated with <tt>key</tt>, or
2933	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>.
2932	>	* @return the previous value associated with {@code key}, or
2933	>	*         {@code null} if there was no mapping for {@code key}
2934		* @throws NullPointerException if the specified key is null
2935		*/
2936	<	public V remove(Object key) {
2937	<	int hash = hash(key);
2938	<	return segmentFor(hash).remove(key, hash, null);
2936	>	@SuppressWarnings("unchecked") public V remove(Object key) {
2937	>	if (key == null)
2938	>	throw new NullPointerException();
2939	>	return (V)internalReplace(key, null, null);
2940		}
2941
2942		/**
#	Line 925 | Line 2945 | public class ConcurrentHashMap<K, V> ext
2945		* @throws NullPointerException if the specified key is null
2946		*/
2947		public boolean remove(Object key, Object value) {
2948	+	if (key == null)
2949	+	throw new NullPointerException();
2950		if (value == null)
2951		return false;
2952	<	int hash = hash(key);
931	<	return segmentFor(hash).remove(key, hash, value) != null;
2952	>	return internalReplace(key, null, value) != null;
2953		}
2954
2955		/**
#	Line 937 | Line 2958 | public class ConcurrentHashMap<K, V> ext
2958		* @throws NullPointerException if any of the arguments are null
2959		*/
2960		public boolean replace(K key, V oldValue, V newValue) {
2961	<	if (oldValue == null || newValue == null)
2961	>	if (key == null || oldValue == null || newValue == null)
2962		throw new NullPointerException();
2963	<	int hash = hash(key);
943	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
2963	>	return internalReplace(key, newValue, oldValue) != null;
2964		}
2965
2966		/**
2967		* {@inheritDoc}
2968		*
2969		* @return the previous value associated with the specified key,
2970	<	*         or <tt>null</tt> if there was no mapping for the key
2970	>	*         or {@code null} if there was no mapping for the key
2971		* @throws NullPointerException if the specified key or value is null
2972		*/
2973	<	public V replace(K key, V value) {
2974	<	if (value == null)
2973	>	@SuppressWarnings("unchecked") public V replace(K key, V value) {
2974	>	if (key == null || value == null)
2975		throw new NullPointerException();
2976	<	int hash = hash(key);
957	<	return segmentFor(hash).replace(key, hash, value);
2976	>	return (V)internalReplace(key, value, null);
2977		}
2978
2979		/**
2980		* Removes all of the mappings from this map.
2981		*/
2982		public void clear() {
2983	<	for (int i = 0; i < segments.length; ++i)
965	<	segments[i].clear();
2983	>	internalClear();
2984		}
2985
2986		/**
2987		* Returns a {@link Set} view of the keys contained in this map.
2988		* The set is backed by the map, so changes to the map are
2989	<	* reflected in the set, and vice-versa.  The set supports element
972	<	* removal, which removes the corresponding mapping from this map,
973	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
974	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
975	<	* operations.  It does not support the <tt>add</tt> or
976	<	* <tt>addAll</tt> operations.
2989	>	* reflected in the set, and vice-versa.
2990		*
2991	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2992	<	* that will never throw {@link ConcurrentModificationException},
2993	<	* and guarantees to traverse elements as they existed upon
2994	<	* construction of the iterator, and may (but is not guaranteed to)
2995	<	* reflect any modifications subsequent to construction.
2991	>	* @return the set view
2992	>	*/
2993	>	public KeySetView<K,V> keySet() {
2994	>	KeySetView<K,V> ks = keySet;
2995	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2996	>	}
2997	>
2998	>	/**
2999	>	* Returns a {@link Set} view of the keys in this map, using the
3000	>	* given common mapped value for any additions (i.e., {@link
3001	>	* Collection#add} and {@link Collection#addAll}). This is of
3002	>	* course only appropriate if it is acceptable to use the same
3003	>	* value for all additions from this view.
3004	>	*
3005	>	* @param mappedValue the mapped value to use for any
3006	>	* additions.
3007	>	* @return the set view
3008	>	* @throws NullPointerException if the mappedValue is null
3009		*/
3010	<	public Set<K> keySet() {
3011	<	Set<K> ks = keySet;
3012	<	return (ks != null) ? ks : (keySet = new KeySet());
3010	>	public KeySetView<K,V> keySet(V mappedValue) {
3011	>	if (mappedValue == null)
3012	>	throw new NullPointerException();
3013	>	return new KeySetView<K,V>(this, mappedValue);
3014		}
3015
3016		/**
3017		* Returns a {@link Collection} view of the values contained in this map.
3018		* The collection is backed by the map, so changes to the map are
3019	<	* reflected in the collection, and vice-versa.  The collection
993	<	* supports element removal, which removes the corresponding
994	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
995	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
996	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
997	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
998	<	*
999	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1000	<	* that will never throw {@link ConcurrentModificationException},
1001	<	* and guarantees to traverse elements as they existed upon
1002	<	* construction of the iterator, and may (but is not guaranteed to)
1003	<	* reflect any modifications subsequent to construction.
3019	>	* reflected in the collection, and vice-versa.
3020		*/
3021	<	public Collection<V> values() {
3022	<	Collection<V> vs = values;
3023	<	return (vs != null) ? vs : (values = new Values());
3021	>	public ValuesView<K,V> values() {
3022	>	ValuesView<K,V> vs = values;
3023	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
3024		}
3025
3026		/**
#	Line 1012 | Line 3028 | public class ConcurrentHashMap<K, V> ext
3028		* The set is backed by the map, so changes to the map are
3029		* reflected in the set, and vice-versa.  The set supports element
3030		* removal, which removes the corresponding mapping from the map,
3031	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
3032	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
3033	<	* operations.  It does not support the <tt>add</tt> or
3034	<	* <tt>addAll</tt> operations.
3031	>	* via the {@code Iterator.remove}, {@code Set.remove},
3032	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
3033	>	* operations.  It does not support the {@code add} or
3034	>	* {@code addAll} operations.
3035		*
3036	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
3036	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
3037		* that will never throw {@link ConcurrentModificationException},
3038		* and guarantees to traverse elements as they existed upon
3039		* construction of the iterator, and may (but is not guaranteed to)
3040		* reflect any modifications subsequent to construction.
3041		*/
3042		public Set<Map.Entry<K,V>> entrySet() {
3043	<	Set<Map.Entry<K,V>> es = entrySet;
3044	<	return (es != null) ? es : (entrySet = new EntrySet());
3043	>	EntrySetView<K,V> es = entrySet;
3044	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
3045		}
3046
3047		/**
3048		* Returns an enumeration of the keys in this table.
3049		*
3050		* @return an enumeration of the keys in this table
3051	<	* @see #keySet
3051	>	* @see #keySet()
3052		*/
3053		public Enumeration<K> keys() {
3054	<	return new KeyIterator();
3054	>	return new KeyIterator<K,V>(this);
3055		}
3056
3057		/**
3058		* Returns an enumeration of the values in this table.
3059		*
3060		* @return an enumeration of the values in this table
3061	<	* @see #values
3061	>	* @see #values()
3062		*/
3063		public Enumeration<V> elements() {
3064	<	return new ValueIterator();
3064	>	return new ValueIterator<K,V>(this);
3065		}
3066
3067	<	/* ---------------- Iterator Support -------------- */
3068	<
3069	<	abstract class HashIterator {
3070	<	int nextSegmentIndex;
3071	<	int nextTableIndex;
3072	<	HashEntry<K,V>[] currentTable;
3073	<	HashEntry<K, V> nextEntry;
3074	<	HashEntry<K, V> lastReturned;
3067	>	/**
3068	>	* Returns a partitionable iterator of the keys in this map.
3069	>	*
3070	>	* @return a partitionable iterator of the keys in this map
3071	>	*/
3072	>	public Spliterator<K> keySpliterator() {
3073	>	return new KeyIterator<K,V>(this);
3074	>	}
3075
3076	<	HashIterator() {
3077	<	nextSegmentIndex = segments.length - 1;
3078	<	nextTableIndex = -1;
3079	<	advance();
3080	<	}
3076	>	/**
3077	>	* Returns a partitionable iterator of the values in this map.
3078	>	*
3079	>	* @return a partitionable iterator of the values in this map
3080	>	*/
3081	>	public Spliterator<V> valueSpliterator() {
3082	>	return new ValueIterator<K,V>(this);
3083	>	}
3084
3085	<	public boolean hasMoreElements() { return hasNext(); }
3085	>	/**
3086	>	* Returns a partitionable iterator of the entries in this map.
3087	>	*
3088	>	* @return a partitionable iterator of the entries in this map
3089	>	*/
3090	>	public Spliterator<Map.Entry<K,V>> entrySpliterator() {
3091	>	return new EntryIterator<K,V>(this);
3092	>	}
3093
3094	<	final void advance() {
3095	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
3096	<	return;
3094	>	/**
3095	>	* Returns the hash code value for this {@link Map}, i.e.,
3096	>	* the sum of, for each key-value pair in the map,
3097	>	* {@code key.hashCode() ^ value.hashCode()}.
3098	>	*
3099	>	* @return the hash code value for this map
3100	>	*/
3101	>	public int hashCode() {
3102	>	int h = 0;
3103	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3104	>	Object v;
3105	>	while ((v = it.advance()) != null) {
3106	>	h += it.nextKey.hashCode() ^ v.hashCode();
3107	>	}
3108	>	return h;
3109	>	}
3110
3111	<	while (nextTableIndex >= 0) {
3112	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
3113	<	return;
3111	>	/**
3112	>	* Returns a string representation of this map.  The string
3113	>	* representation consists of a list of key-value mappings (in no
3114	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
3115	>	* mappings are separated by the characters {@code ", "} (comma
3116	>	* and space).  Each key-value mapping is rendered as the key
3117	>	* followed by an equals sign ("{@code =}") followed by the
3118	>	* associated value.
3119	>	*
3120	>	* @return a string representation of this map
3121	>	*/
3122	>	public String toString() {
3123	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3124	>	StringBuilder sb = new StringBuilder();
3125	>	sb.append('{');
3126	>	Object v;
3127	>	if ((v = it.advance()) != null) {
3128	>	for (;;) {
3129	>	Object k = it.nextKey;
3130	>	sb.append(k == this ? "(this Map)" : k);
3131	>	sb.append('=');
3132	>	sb.append(v == this ? "(this Map)" : v);
3133	>	if ((v = it.advance()) == null)
3134	>	break;
3135	>	sb.append(',').append(' ');
3136		}
3137	+	}
3138	+	return sb.append('}').toString();
3139	+	}
3140
3141	<	while (nextSegmentIndex >= 0) {
3142	<	Segment<K,V> seg = segments[nextSegmentIndex--];
3143	<	if (seg.count != 0) {
3144	<	currentTable = seg.table;
3145	<	for (int j = currentTable.length - 1; j >= 0; --j) {
3146	<	if ( (nextEntry = currentTable[j]) != null) {
3147	<	nextTableIndex = j - 1;
3148	<	return;
3149	<	}
3150	<	}
3151	<	}
3141	>	/**
3142	>	* Compares the specified object with this map for equality.
3143	>	* Returns {@code true} if the given object is a map with the same
3144	>	* mappings as this map.  This operation may return misleading
3145	>	* results if either map is concurrently modified during execution
3146	>	* of this method.
3147	>	*
3148	>	* @param o object to be compared for equality with this map
3149	>	* @return {@code true} if the specified object is equal to this map
3150	>	*/
3151	>	public boolean equals(Object o) {
3152	>	if (o != this) {
3153	>	if (!(o instanceof Map))
3154	>	return false;
3155	>	Map<?,?> m = (Map<?,?>) o;
3156	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3157	>	Object val;
3158	>	while ((val = it.advance()) != null) {
3159	>	Object v = m.get(it.nextKey);
3160	>	if (v == null || (v != val && !v.equals(val)))
3161	>	return false;
3162	>	}
3163	>	for (Map.Entry<?,?> e : m.entrySet()) {
3164	>	Object mk, mv, v;
3165	>	if ((mk = e.getKey()) == null ||
3166	>	(mv = e.getValue()) == null ||
3167	>	(v = internalGet(mk)) == null ||
3168	>	(mv != v && !mv.equals(v)))
3169	>	return false;
3170		}
3171		}
3172	+	return true;
3173	+	}
3174
3175	<	public boolean hasNext() { return nextEntry != null; }
3175	>	/* ----------------Iterators -------------- */
3176
3177	<	HashEntry<K,V> nextEntry() {
3178	<	if (nextEntry == null)
3177	>	@SuppressWarnings("serial") static final class KeyIterator<K,V> extends Traverser<K,V,Object>
3178	>	implements Spliterator<K>, Enumeration<K> {
3179	>	KeyIterator(ConcurrentHashMap<K, V> map) { super(map); }
3180	>	KeyIterator(Traverser<K,V,Object> it) {
3181	>	super(it);
3182	>	}
3183	>	public KeyIterator<K,V> split() {
3184	>	if (nextKey != null)
3185	>	throw new IllegalStateException();
3186	>	return new KeyIterator<K,V>(this);
3187	>	}
3188	>	@SuppressWarnings("unchecked") public final K next() {
3189	>	if (nextVal == null && advance() == null)
3190		throw new NoSuchElementException();
3191	<	lastReturned = nextEntry;
3192	<	advance();
3193	<	return lastReturned;
3191	>	Object k = nextKey;
3192	>	nextVal = null;
3193	>	return (K) k;
3194		}
3195
3196	<	public void remove() {
3197	<	if (lastReturned == null)
3196	>	public final K nextElement() { return next(); }
3197	>	}
3198	>
3199	>	@SuppressWarnings("serial") static final class ValueIterator<K,V> extends Traverser<K,V,Object>
3200	>	implements Spliterator<V>, Enumeration<V> {
3201	>	ValueIterator(ConcurrentHashMap<K, V> map) { super(map); }
3202	>	ValueIterator(Traverser<K,V,Object> it) {
3203	>	super(it);
3204	>	}
3205	>	public ValueIterator<K,V> split() {
3206	>	if (nextKey != null)
3207		throw new IllegalStateException();
3208	<	ConcurrentHashMap.this.remove(lastReturned.key);
1105	<	lastReturned = null;
3208	>	return new ValueIterator<K,V>(this);
3209		}
1107	–	}
3210
3211	<	final class KeyIterator
3212	<	extends HashIterator
3213	<	implements Iterator<K>, Enumeration<K>
3214	<	{
3215	<	public K next()        { return super.nextEntry().key; }
3216	<	public K nextElement() { return super.nextEntry().key; }
3211	>	@SuppressWarnings("unchecked") public final V next() {
3212	>	Object v;
3213	>	if ((v = nextVal) == null && (v = advance()) == null)
3214	>	throw new NoSuchElementException();
3215	>	nextVal = null;
3216	>	return (V) v;
3217	>	}
3218	>
3219	>	public final V nextElement() { return next(); }
3220		}
3221
3222	<	final class ValueIterator
3223	<	extends HashIterator
3224	<	implements Iterator<V>, Enumeration<V>
3225	<	{
3226	<	public V next()        { return super.nextEntry().value; }
3227	<	public V nextElement() { return super.nextEntry().value; }
3222	>	@SuppressWarnings("serial") static final class EntryIterator<K,V> extends Traverser<K,V,Object>
3223	>	implements Spliterator<Map.Entry<K,V>> {
3224	>	EntryIterator(ConcurrentHashMap<K, V> map) { super(map); }
3225	>	EntryIterator(Traverser<K,V,Object> it) {
3226	>	super(it);
3227	>	}
3228	>	public EntryIterator<K,V> split() {
3229	>	if (nextKey != null)
3230	>	throw new IllegalStateException();
3231	>	return new EntryIterator<K,V>(this);
3232	>	}
3233	>
3234	>	@SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
3235	>	Object v;
3236	>	if ((v = nextVal) == null && (v = advance()) == null)
3237	>	throw new NoSuchElementException();
3238	>	Object k = nextKey;
3239	>	nextVal = null;
3240	>	return new MapEntry<K,V>((K)k, (V)v, map);
3241	>	}
3242		}
3243
3244		/**
3245	<	* Custom Entry class used by EntryIterator.next(), that relays
1127	<	* setValue changes to the underlying map.
3245	>	* Exported Entry for iterators
3246		*/
3247	<	final class WriteThroughEntry
3248	<	extends AbstractMap.SimpleEntry<K,V>
3249	<	{
3250	<	WriteThroughEntry(K k, V v) {
3251	<	super(k,v);
3247	>	static final class MapEntry<K,V> implements Map.Entry<K, V> {
3248	>	final K key; // non-null
3249	>	V val;       // non-null
3250	>	final ConcurrentHashMap<K, V> map;
3251	>	MapEntry(K key, V val, ConcurrentHashMap<K, V> map) {
3252	>	this.key = key;
3253	>	this.val = val;
3254	>	this.map = map;
3255	>	}
3256	>	public final K getKey()       { return key; }
3257	>	public final V getValue()     { return val; }
3258	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3259	>	public final String toString(){ return key + "=" + val; }
3260	>
3261	>	public final boolean equals(Object o) {
3262	>	Object k, v; Map.Entry<?,?> e;
3263	>	return ((o instanceof Map.Entry) &&
3264	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3265	>	(v = e.getValue()) != null &&
3266	>	(k == key || k.equals(key)) &&
3267	>	(v == val || v.equals(val)));
3268		}
3269
3270		/**
3271	<	* Set our entry's value and write through to the map. The
3272	<	* value to return is somewhat arbitrary here. Since a
3273	<	* WriteThroughEntry does not necessarily track asynchronous
3274	<	* changes, the most recent "previous" value could be
3275	<	* different from what we return (or could even have been
3276	<	* removed in which case the put will re-establish). We do not
1143	<	* and cannot guarantee more.
3271	>	* Sets our entry's value and writes through to the map. The
3272	>	* value to return is somewhat arbitrary here. Since we do not
3273	>	* necessarily track asynchronous changes, the most recent
3274	>	* "previous" value could be different from what we return (or
3275	>	* could even have been removed in which case the put will
3276	>	* re-establish). We do not and cannot guarantee more.
3277		*/
3278	<	public V setValue(V value) {
3278	>	public final V setValue(V value) {
3279		if (value == null) throw new NullPointerException();
3280	<	V v = super.setValue(value);
3281	<	ConcurrentHashMap.this.put(getKey(), value);
3280	>	V v = val;
3281	>	val = value;
3282	>	map.put(key, value);
3283		return v;
3284		}
3285		}
3286
3287	<	final class EntryIterator
3288	<	extends HashIterator
3289	<	implements Iterator<Entry<K,V>>
3290	<	{
3291	<	public Map.Entry<K,V> next() {
3292	<	HashEntry<K,V> e = super.nextEntry();
3293	<	return new WriteThroughEntry(e.key, e.value);
3287	>	/* ---------------- Serialization Support -------------- */
3288	>
3289	>	/**
3290	>	* Stripped-down version of helper class used in previous version,
3291	>	* declared for the sake of serialization compatibility
3292	>	*/
3293	>	static class Segment<K,V> implements Serializable {
3294	>	private static final long serialVersionUID = 2249069246763182397L;
3295	>	final float loadFactor;
3296	>	Segment(float lf) { this.loadFactor = lf; }
3297	>	}
3298	>
3299	>	/**
3300	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3301	>	* stream (i.e., serializes it).
3302	>	* @param s the stream
3303	>	* @serialData
3304	>	* the key (Object) and value (Object)
3305	>	* for each key-value mapping, followed by a null pair.
3306	>	* The key-value mappings are emitted in no particular order.
3307	>	*/
3308	>	@SuppressWarnings("unchecked") private void writeObject(java.io.ObjectOutputStream s)
3309	>	throws java.io.IOException {
3310	>	if (segments == null) { // for serialization compatibility
3311	>	segments = (Segment<K,V>[])
3312	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3313	>	for (int i = 0; i < segments.length; ++i)
3314	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3315		}
3316	+	s.defaultWriteObject();
3317	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3318	+	Object v;
3319	+	while ((v = it.advance()) != null) {
3320	+	s.writeObject(it.nextKey);
3321	+	s.writeObject(v);
3322	+	}
3323	+	s.writeObject(null);
3324	+	s.writeObject(null);
3325	+	segments = null; // throw away
3326		}
3327
3328	<	final class KeySet extends AbstractSet<K> {
3329	<	public Iterator<K> iterator() {
3330	<	return new KeyIterator();
3328	>	/**
3329	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3330	>	* @param s the stream
3331	>	*/
3332	>	@SuppressWarnings("unchecked") private void readObject(java.io.ObjectInputStream s)
3333	>	throws java.io.IOException, ClassNotFoundException {
3334	>	s.defaultReadObject();
3335	>	this.segments = null; // unneeded
3336	>	// initialize transient final field
3337	>	UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
3338	>
3339	>	// Create all nodes, then place in table once size is known
3340	>	long size = 0L;
3341	>	Node p = null;
3342	>	for (;;) {
3343	>	K k = (K) s.readObject();
3344	>	V v = (V) s.readObject();
3345	>	if (k != null && v != null) {
3346	>	int h = spread(k.hashCode());
3347	>	p = new Node(h, k, v, p);
3348	>	++size;
3349	>	}
3350	>	else
3351	>	break;
3352		}
3353	<	public int size() {
3354	<	return ConcurrentHashMap.this.size();
3353	>	if (p != null) {
3354	>	boolean init = false;
3355	>	int n;
3356	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3357	>	n = MAXIMUM_CAPACITY;
3358	>	else {
3359	>	int sz = (int)size;
3360	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3361	>	}
3362	>	int sc = sizeCtl;
3363	>	boolean collide = false;
3364	>	if (n > sc &&
3365	>	UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
3366	>	try {
3367	>	if (table == null) {
3368	>	init = true;
3369	>	Node[] tab = new Node[n];
3370	>	int mask = n - 1;
3371	>	while (p != null) {
3372	>	int j = p.hash & mask;
3373	>	Node next = p.next;
3374	>	Node q = p.next = tabAt(tab, j);
3375	>	setTabAt(tab, j, p);
3376	>	if (!collide && q != null && q.hash == p.hash)
3377	>	collide = true;
3378	>	p = next;
3379	>	}
3380	>	table = tab;
3381	>	counter.add(size);
3382	>	sc = n - (n >>> 2);
3383	>	}
3384	>	} finally {
3385	>	sizeCtl = sc;
3386	>	}
3387	>	if (collide) { // rescan and convert to TreeBins
3388	>	Node[] tab = table;
3389	>	for (int i = 0; i < tab.length; ++i) {
3390	>	int c = 0;
3391	>	for (Node e = tabAt(tab, i); e != null; e = e.next) {
3392	>	if (++c > TREE_THRESHOLD &&
3393	>	(e.key instanceof Comparable)) {
3394	>	replaceWithTreeBin(tab, i, e.key);
3395	>	break;
3396	>	}
3397	>	}
3398	>	}
3399	>	}
3400	>	}
3401	>	if (!init) { // Can only happen if unsafely published.
3402	>	while (p != null) {
3403	>	internalPut(p.key, p.val);
3404	>	p = p.next;
3405	>	}
3406	>	}
3407		}
3408	<	public boolean contains(Object o) {
3409	<	return ConcurrentHashMap.this.containsKey(o);
3408	>	}
3409	>
3410	>
3411	>	// -------------------------------------------------------
3412	>
3413	>	// Sams
3414	>	/** Interface describing a void action of one argument */
3415	>	public interface Action<A> { void apply(A a); }
3416	>	/** Interface describing a void action of two arguments */
3417	>	public interface BiAction<A,B> { void apply(A a, B b); }
3418	>	/** Interface describing a function of one argument */
3419	>	public interface Fun<A,T> { T apply(A a); }
3420	>	/** Interface describing a function of two arguments */
3421	>	public interface BiFun<A,B,T> { T apply(A a, B b); }
3422	>	/** Interface describing a function of no arguments */
3423	>	public interface Generator<T> { T apply(); }
3424	>	/** Interface describing a function mapping its argument to a double */
3425	>	public interface ObjectToDouble<A> { double apply(A a); }
3426	>	/** Interface describing a function mapping its argument to a long */
3427	>	public interface ObjectToLong<A> { long apply(A a); }
3428	>	/** Interface describing a function mapping its argument to an int */
3429	>	public interface ObjectToInt<A> {int apply(A a); }
3430	>	/** Interface describing a function mapping two arguments to a double */
3431	>	public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
3432	>	/** Interface describing a function mapping two arguments to a long */
3433	>	public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
3434	>	/** Interface describing a function mapping two arguments to an int */
3435	>	public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
3436	>	/** Interface describing a function mapping a double to a double */
3437	>	public interface DoubleToDouble { double apply(double a); }
3438	>	/** Interface describing a function mapping a long to a long */
3439	>	public interface LongToLong { long apply(long a); }
3440	>	/** Interface describing a function mapping an int to an int */
3441	>	public interface IntToInt { int apply(int a); }
3442	>	/** Interface describing a function mapping two doubles to a double */
3443	>	public interface DoubleByDoubleToDouble { double apply(double a, double b); }
3444	>	/** Interface describing a function mapping two longs to a long */
3445	>	public interface LongByLongToLong { long apply(long a, long b); }
3446	>	/** Interface describing a function mapping two ints to an int */
3447	>	public interface IntByIntToInt { int apply(int a, int b); }
3448	>
3449	>
3450	>	// -------------------------------------------------------
3451	>
3452	>	/**
3453	>	* Performs the given action for each (key, value).
3454	>	*
3455	>	* @param action the action
3456	>	*/
3457	>	public void forEach(BiAction<K,V> action) {
3458	>	ForkJoinTasks.forEach
3459	>	(this, action).invoke();
3460	>	}
3461	>
3462	>	/**
3463	>	* Performs the given action for each non-null transformation
3464	>	* of each (key, value).
3465	>	*
3466	>	* @param transformer a function returning the transformation
3467	>	* for an element, or null of there is no transformation (in
3468	>	* which case the action is not applied).
3469	>	* @param action the action
3470	>	*/
3471	>	public <U> void forEach(BiFun<? super K, ? super V, ? extends U> transformer,
3472	>	Action<U> action) {
3473	>	ForkJoinTasks.forEach
3474	>	(this, transformer, action).invoke();
3475	>	}
3476	>
3477	>	/**
3478	>	* Returns a non-null result from applying the given search
3479	>	* function on each (key, value), or null if none.  Upon
3480	>	* success, further element processing is suppressed and the
3481	>	* results of any other parallel invocations of the search
3482	>	* function are ignored.
3483	>	*
3484	>	* @param searchFunction a function returning a non-null
3485	>	* result on success, else null
3486	>	* @return a non-null result from applying the given search
3487	>	* function on each (key, value), or null if none
3488	>	*/
3489	>	public <U> U search(BiFun<? super K, ? super V, ? extends U> searchFunction) {
3490	>	return ForkJoinTasks.search
3491	>	(this, searchFunction).invoke();
3492	>	}
3493	>
3494	>	/**
3495	>	* Returns the result of accumulating the given transformation
3496	>	* of all (key, value) pairs using the given reducer to
3497	>	* combine values, or null if none.
3498	>	*
3499	>	* @param transformer a function returning the transformation
3500	>	* for an element, or null of there is no transformation (in
3501	>	* which case it is not combined).
3502	>	* @param reducer a commutative associative combining function
3503	>	* @return the result of accumulating the given transformation
3504	>	* of all (key, value) pairs
3505	>	*/
3506	>	public <U> U reduce(BiFun<? super K, ? super V, ? extends U> transformer,
3507	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3508	>	return ForkJoinTasks.reduce
3509	>	(this, transformer, reducer).invoke();
3510	>	}
3511	>
3512	>	/**
3513	>	* Returns the result of accumulating the given transformation
3514	>	* of all (key, value) pairs using the given reducer to
3515	>	* combine values, and the given basis as an identity value.
3516	>	*
3517	>	* @param transformer a function returning the transformation
3518	>	* for an element
3519	>	* @param basis the identity (initial default value) for the reduction
3520	>	* @param reducer a commutative associative combining function
3521	>	* @return the result of accumulating the given transformation
3522	>	* of all (key, value) pairs
3523	>	*/
3524	>	public double reduceToDouble(ObjectByObjectToDouble<? super K, ? super V> transformer,
3525	>	double basis,
3526	>	DoubleByDoubleToDouble reducer) {
3527	>	return ForkJoinTasks.reduceToDouble
3528	>	(this, transformer, basis, reducer).invoke();
3529	>	}
3530	>
3531	>	/**
3532	>	* Returns the result of accumulating the given transformation
3533	>	* of all (key, value) pairs using the given reducer to
3534	>	* combine values, and the given basis as an identity value.
3535	>	*
3536	>	* @param transformer a function returning the transformation
3537	>	* for an element
3538	>	* @param basis the identity (initial default value) for the reduction
3539	>	* @param reducer a commutative associative combining function
3540	>	* @return the result of accumulating the given transformation
3541	>	* of all (key, value) pairs
3542	>	*/
3543	>	public long reduceToLong(ObjectByObjectToLong<? super K, ? super V> transformer,
3544	>	long basis,
3545	>	LongByLongToLong reducer) {
3546	>	return ForkJoinTasks.reduceToLong
3547	>	(this, transformer, basis, reducer).invoke();
3548	>	}
3549	>
3550	>	/**
3551	>	* Returns the result of accumulating the given transformation
3552	>	* of all (key, value) pairs using the given reducer to
3553	>	* combine values, and the given basis as an identity value.
3554	>	*
3555	>	* @param transformer a function returning the transformation
3556	>	* for an element
3557	>	* @param basis the identity (initial default value) for the reduction
3558	>	* @param reducer a commutative associative combining function
3559	>	* @return the result of accumulating the given transformation
3560	>	* of all (key, value) pairs
3561	>	*/
3562	>	public int reduceToInt(ObjectByObjectToInt<? super K, ? super V> transformer,
3563	>	int basis,
3564	>	IntByIntToInt reducer) {
3565	>	return ForkJoinTasks.reduceToInt
3566	>	(this, transformer, basis, reducer).invoke();
3567	>	}
3568	>
3569	>	/**
3570	>	* Performs the given action for each key.
3571	>	*
3572	>	* @param action the action
3573	>	*/
3574	>	public void forEachKey(Action<K> action) {
3575	>	ForkJoinTasks.forEachKey
3576	>	(this, action).invoke();
3577	>	}
3578	>
3579	>	/**
3580	>	* Performs the given action for each non-null transformation
3581	>	* of each key.
3582	>	*
3583	>	* @param transformer a function returning the transformation
3584	>	* for an element, or null of there is no transformation (in
3585	>	* which case the action is not applied).
3586	>	* @param action the action
3587	>	*/
3588	>	public <U> void forEachKey(Fun<? super K, ? extends U> transformer,
3589	>	Action<U> action) {
3590	>	ForkJoinTasks.forEachKey
3591	>	(this, transformer, action).invoke();
3592	>	}
3593	>
3594	>	/**
3595	>	* Returns a non-null result from applying the given search
3596	>	* function on each key, or null if none. Upon success,
3597	>	* further element processing is suppressed and the results of
3598	>	* any other parallel invocations of the search function are
3599	>	* ignored.
3600	>	*
3601	>	* @param searchFunction a function returning a non-null
3602	>	* result on success, else null
3603	>	* @return a non-null result from applying the given search
3604	>	* function on each key, or null if none
3605	>	*/
3606	>	public <U> U searchKeys(Fun<? super K, ? extends U> searchFunction) {
3607	>	return ForkJoinTasks.searchKeys
3608	>	(this, searchFunction).invoke();
3609	>	}
3610	>
3611	>	/**
3612	>	* Returns the result of accumulating all keys using the given
3613	>	* reducer to combine values, or null if none.
3614	>	*
3615	>	* @param reducer a commutative associative combining function
3616	>	* @return the result of accumulating all keys using the given
3617	>	* reducer to combine values, or null if none
3618	>	*/
3619	>	public K reduceKeys(BiFun<? super K, ? super K, ? extends K> reducer) {
3620	>	return ForkJoinTasks.reduceKeys
3621	>	(this, reducer).invoke();
3622	>	}
3623	>
3624	>	/**
3625	>	* Returns the result of accumulating the given transformation
3626	>	* of all keys using the given reducer to combine values, or
3627	>	* null if none.
3628	>	*
3629	>	* @param transformer a function returning the transformation
3630	>	* for an element, or null of there is no transformation (in
3631	>	* which case it is not combined).
3632	>	* @param reducer a commutative associative combining function
3633	>	* @return the result of accumulating the given transformation
3634	>	* of all keys
3635	>	*/
3636	>	public <U> U reduceKeys(Fun<? super K, ? extends U> transformer,
3637	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3638	>	return ForkJoinTasks.reduceKeys
3639	>	(this, transformer, reducer).invoke();
3640	>	}
3641	>
3642	>	/**
3643	>	* Returns the result of accumulating the given transformation
3644	>	* of all keys using the given reducer to combine values, and
3645	>	* the given basis as an identity value.
3646	>	*
3647	>	* @param transformer a function returning the transformation
3648	>	* for an element
3649	>	* @param basis the identity (initial default value) for the reduction
3650	>	* @param reducer a commutative associative combining function
3651	>	* @return  the result of accumulating the given transformation
3652	>	* of all keys
3653	>	*/
3654	>	public double reduceKeysToDouble(ObjectToDouble<? super K> transformer,
3655	>	double basis,
3656	>	DoubleByDoubleToDouble reducer) {
3657	>	return ForkJoinTasks.reduceKeysToDouble
3658	>	(this, transformer, basis, reducer).invoke();
3659	>	}
3660	>
3661	>	/**
3662	>	* Returns the result of accumulating the given transformation
3663	>	* of all keys using the given reducer to combine values, and
3664	>	* the given basis as an identity value.
3665	>	*
3666	>	* @param transformer a function returning the transformation
3667	>	* for an element
3668	>	* @param basis the identity (initial default value) for the reduction
3669	>	* @param reducer a commutative associative combining function
3670	>	* @return the result of accumulating the given transformation
3671	>	* of all keys
3672	>	*/
3673	>	public long reduceKeysToLong(ObjectToLong<? super K> transformer,
3674	>	long basis,
3675	>	LongByLongToLong reducer) {
3676	>	return ForkJoinTasks.reduceKeysToLong
3677	>	(this, transformer, basis, reducer).invoke();
3678	>	}
3679	>
3680	>	/**
3681	>	* Returns the result of accumulating the given transformation
3682	>	* of all keys using the given reducer to combine values, and
3683	>	* the given basis as an identity value.
3684	>	*
3685	>	* @param transformer a function returning the transformation
3686	>	* for an element
3687	>	* @param basis the identity (initial default value) for the reduction
3688	>	* @param reducer a commutative associative combining function
3689	>	* @return the result of accumulating the given transformation
3690	>	* of all keys
3691	>	*/
3692	>	public int reduceKeysToInt(ObjectToInt<? super K> transformer,
3693	>	int basis,
3694	>	IntByIntToInt reducer) {
3695	>	return ForkJoinTasks.reduceKeysToInt
3696	>	(this, transformer, basis, reducer).invoke();
3697	>	}
3698	>
3699	>	/**
3700	>	* Performs the given action for each value.
3701	>	*
3702	>	* @param action the action
3703	>	*/
3704	>	public void forEachValue(Action<V> action) {
3705	>	ForkJoinTasks.forEachValue
3706	>	(this, action).invoke();
3707	>	}
3708	>
3709	>	/**
3710	>	* Performs the given action for each non-null transformation
3711	>	* of each value.
3712	>	*
3713	>	* @param transformer a function returning the transformation
3714	>	* for an element, or null of there is no transformation (in
3715	>	* which case the action is not applied).
3716	>	*/
3717	>	public <U> void forEachValue(Fun<? super V, ? extends U> transformer,
3718	>	Action<U> action) {
3719	>	ForkJoinTasks.forEachValue
3720	>	(this, transformer, action).invoke();
3721	>	}
3722	>
3723	>	/**
3724	>	* Returns a non-null result from applying the given search
3725	>	* function on each value, or null if none.  Upon success,
3726	>	* further element processing is suppressed and the results of
3727	>	* any other parallel invocations of the search function are
3728	>	* ignored.
3729	>	*
3730	>	* @param searchFunction a function returning a non-null
3731	>	* result on success, else null
3732	>	* @return a non-null result from applying the given search
3733	>	* function on each value, or null if none
3734	>	*
3735	>	*/
3736	>	public <U> U searchValues(Fun<? super V, ? extends U> searchFunction) {
3737	>	return ForkJoinTasks.searchValues
3738	>	(this, searchFunction).invoke();
3739	>	}
3740	>
3741	>	/**
3742	>	* Returns the result of accumulating all values using the
3743	>	* given reducer to combine values, or null if none.
3744	>	*
3745	>	* @param reducer a commutative associative combining function
3746	>	* @return  the result of accumulating all values
3747	>	*/
3748	>	public V reduceValues(BiFun<? super V, ? super V, ? extends V> reducer) {
3749	>	return ForkJoinTasks.reduceValues
3750	>	(this, reducer).invoke();
3751	>	}
3752	>
3753	>	/**
3754	>	* Returns the result of accumulating the given transformation
3755	>	* of all values using the given reducer to combine values, or
3756	>	* null if none.
3757	>	*
3758	>	* @param transformer a function returning the transformation
3759	>	* for an element, or null of there is no transformation (in
3760	>	* which case it is not combined).
3761	>	* @param reducer a commutative associative combining function
3762	>	* @return the result of accumulating the given transformation
3763	>	* of all values
3764	>	*/
3765	>	public <U> U reduceValues(Fun<? super V, ? extends U> transformer,
3766	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3767	>	return ForkJoinTasks.reduceValues
3768	>	(this, transformer, reducer).invoke();
3769	>	}
3770	>
3771	>	/**
3772	>	* Returns the result of accumulating the given transformation
3773	>	* of all values using the given reducer to combine values,
3774	>	* and the given basis as an identity value.
3775	>	*
3776	>	* @param transformer a function returning the transformation
3777	>	* for an element
3778	>	* @param basis the identity (initial default value) for the reduction
3779	>	* @param reducer a commutative associative combining function
3780	>	* @return the result of accumulating the given transformation
3781	>	* of all values
3782	>	*/
3783	>	public double reduceValuesToDouble(ObjectToDouble<? super V> transformer,
3784	>	double basis,
3785	>	DoubleByDoubleToDouble reducer) {
3786	>	return ForkJoinTasks.reduceValuesToDouble
3787	>	(this, transformer, basis, reducer).invoke();
3788	>	}
3789	>
3790	>	/**
3791	>	* Returns the result of accumulating the given transformation
3792	>	* of all values using the given reducer to combine values,
3793	>	* and the given basis as an identity value.
3794	>	*
3795	>	* @param transformer a function returning the transformation
3796	>	* for an element
3797	>	* @param basis the identity (initial default value) for the reduction
3798	>	* @param reducer a commutative associative combining function
3799	>	* @return the result of accumulating the given transformation
3800	>	* of all values
3801	>	*/
3802	>	public long reduceValuesToLong(ObjectToLong<? super V> transformer,
3803	>	long basis,
3804	>	LongByLongToLong reducer) {
3805	>	return ForkJoinTasks.reduceValuesToLong
3806	>	(this, transformer, basis, reducer).invoke();
3807	>	}
3808	>
3809	>	/**
3810	>	* Returns the result of accumulating the given transformation
3811	>	* of all values using the given reducer to combine values,
3812	>	* and the given basis as an identity value.
3813	>	*
3814	>	* @param transformer a function returning the transformation
3815	>	* for an element
3816	>	* @param basis the identity (initial default value) for the reduction
3817	>	* @param reducer a commutative associative combining function
3818	>	* @return the result of accumulating the given transformation
3819	>	* of all values
3820	>	*/
3821	>	public int reduceValuesToInt(ObjectToInt<? super V> transformer,
3822	>	int basis,
3823	>	IntByIntToInt reducer) {
3824	>	return ForkJoinTasks.reduceValuesToInt
3825	>	(this, transformer, basis, reducer).invoke();
3826	>	}
3827	>
3828	>	/**
3829	>	* Performs the given action for each entry.
3830	>	*
3831	>	* @param action the action
3832	>	*/
3833	>	public void forEachEntry(Action<Map.Entry<K,V>> action) {
3834	>	ForkJoinTasks.forEachEntry
3835	>	(this, action).invoke();
3836	>	}
3837	>
3838	>	/**
3839	>	* Performs the given action for each non-null transformation
3840	>	* of each entry.
3841	>	*
3842	>	* @param transformer a function returning the transformation
3843	>	* for an element, or null of there is no transformation (in
3844	>	* which case the action is not applied).
3845	>	* @param action the action
3846	>	*/
3847	>	public <U> void forEachEntry(Fun<Map.Entry<K,V>, ? extends U> transformer,
3848	>	Action<U> action) {
3849	>	ForkJoinTasks.forEachEntry
3850	>	(this, transformer, action).invoke();
3851	>	}
3852	>
3853	>	/**
3854	>	* Returns a non-null result from applying the given search
3855	>	* function on each entry, or null if none.  Upon success,
3856	>	* further element processing is suppressed and the results of
3857	>	* any other parallel invocations of the search function are
3858	>	* ignored.
3859	>	*
3860	>	* @param searchFunction a function returning a non-null
3861	>	* result on success, else null
3862	>	* @return a non-null result from applying the given search
3863	>	* function on each entry, or null if none
3864	>	*/
3865	>	public <U> U searchEntries(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
3866	>	return ForkJoinTasks.searchEntries
3867	>	(this, searchFunction).invoke();
3868	>	}
3869	>
3870	>	/**
3871	>	* Returns the result of accumulating all entries using the
3872	>	* given reducer to combine values, or null if none.
3873	>	*
3874	>	* @param reducer a commutative associative combining function
3875	>	* @return the result of accumulating all entries
3876	>	*/
3877	>	public Map.Entry<K,V> reduceEntries(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3878	>	return ForkJoinTasks.reduceEntries
3879	>	(this, reducer).invoke();
3880	>	}
3881	>
3882	>	/**
3883	>	* Returns the result of accumulating the given transformation
3884	>	* of all entries using the given reducer to combine values,
3885	>	* or null if none.
3886	>	*
3887	>	* @param transformer a function returning the transformation
3888	>	* for an element, or null of there is no transformation (in
3889	>	* which case it is not combined).
3890	>	* @param reducer a commutative associative combining function
3891	>	* @return the result of accumulating the given transformation
3892	>	* of all entries
3893	>	*/
3894	>	public <U> U reduceEntries(Fun<Map.Entry<K,V>, ? extends U> transformer,
3895	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3896	>	return ForkJoinTasks.reduceEntries
3897	>	(this, transformer, reducer).invoke();
3898	>	}
3899	>
3900	>	/**
3901	>	* Returns the result of accumulating the given transformation
3902	>	* of all entries using the given reducer to combine values,
3903	>	* and the given basis as an identity value.
3904	>	*
3905	>	* @param transformer a function returning the transformation
3906	>	* for an element
3907	>	* @param basis the identity (initial default value) for the reduction
3908	>	* @param reducer a commutative associative combining function
3909	>	* @return the result of accumulating the given transformation
3910	>	* of all entries
3911	>	*/
3912	>	public double reduceEntriesToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
3913	>	double basis,
3914	>	DoubleByDoubleToDouble reducer) {
3915	>	return ForkJoinTasks.reduceEntriesToDouble
3916	>	(this, transformer, basis, reducer).invoke();
3917	>	}
3918	>
3919	>	/**
3920	>	* Returns the result of accumulating the given transformation
3921	>	* of all entries using the given reducer to combine values,
3922	>	* and the given basis as an identity value.
3923	>	*
3924	>	* @param transformer a function returning the transformation
3925	>	* for an element
3926	>	* @param basis the identity (initial default value) for the reduction
3927	>	* @param reducer a commutative associative combining function
3928	>	* @return  the result of accumulating the given transformation
3929	>	* of all entries
3930	>	*/
3931	>	public long reduceEntriesToLong(ObjectToLong<Map.Entry<K,V>> transformer,
3932	>	long basis,
3933	>	LongByLongToLong reducer) {
3934	>	return ForkJoinTasks.reduceEntriesToLong
3935	>	(this, transformer, basis, reducer).invoke();
3936	>	}
3937	>
3938	>	/**
3939	>	* Returns the result of accumulating the given transformation
3940	>	* of all entries using the given reducer to combine values,
3941	>	* and the given basis as an identity value.
3942	>	*
3943	>	* @param transformer a function returning the transformation
3944	>	* for an element
3945	>	* @param basis the identity (initial default value) for the reduction
3946	>	* @param reducer a commutative associative combining function
3947	>	* @return the result of accumulating the given transformation
3948	>	* of all entries
3949	>	*/
3950	>	public int reduceEntriesToInt(ObjectToInt<Map.Entry<K,V>> transformer,
3951	>	int basis,
3952	>	IntByIntToInt reducer) {
3953	>	return ForkJoinTasks.reduceEntriesToInt
3954	>	(this, transformer, basis, reducer).invoke();
3955	>	}
3956	>
3957	>	/* ----------------Views -------------- */
3958	>
3959	>	/**
3960	>	* Base class for views.
3961	>	*/
3962	>	static abstract class CHMView<K, V> {
3963	>	final ConcurrentHashMap<K, V> map;
3964	>	CHMView(ConcurrentHashMap<K, V> map)  { this.map = map; }
3965	>
3966	>	/**
3967	>	* Returns the map backing this view.
3968	>	*
3969	>	* @return the map backing this view
3970	>	*/
3971	>	public ConcurrentHashMap<K,V> getMap() { return map; }
3972	>
3973	>	public final int size()                 { return map.size(); }
3974	>	public final boolean isEmpty()          { return map.isEmpty(); }
3975	>	public final void clear()               { map.clear(); }
3976	>
3977	>	// implementations below rely on concrete classes supplying these
3978	>	abstract public Iterator<?> iterator();
3979	>	abstract public boolean contains(Object o);
3980	>	abstract public boolean remove(Object o);
3981	>
3982	>	private static final String oomeMsg = "Required array size too large";
3983	>
3984	>	public final Object[] toArray() {
3985	>	long sz = map.mappingCount();
3986	>	if (sz > (long)(MAX_ARRAY_SIZE))
3987	>	throw new OutOfMemoryError(oomeMsg);
3988	>	int n = (int)sz;
3989	>	Object[] r = new Object[n];
3990	>	int i = 0;
3991	>	Iterator<?> it = iterator();
3992	>	while (it.hasNext()) {
3993	>	if (i == n) {
3994	>	if (n >= MAX_ARRAY_SIZE)
3995	>	throw new OutOfMemoryError(oomeMsg);
3996	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
3997	>	n = MAX_ARRAY_SIZE;
3998	>	else
3999	>	n += (n >>> 1) + 1;
4000	>	r = Arrays.copyOf(r, n);
4001	>	}
4002	>	r[i++] = it.next();
4003	>	}
4004	>	return (i == n) ? r : Arrays.copyOf(r, i);
4005		}
4006	<	public boolean remove(Object o) {
4007	<	return ConcurrentHashMap.this.remove(o) != null;
4006	>
4007	>	@SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4008	>	long sz = map.mappingCount();
4009	>	if (sz > (long)(MAX_ARRAY_SIZE))
4010	>	throw new OutOfMemoryError(oomeMsg);
4011	>	int m = (int)sz;
4012	>	T[] r = (a.length >= m) ? a :
4013	>	(T[])java.lang.reflect.Array
4014	>	.newInstance(a.getClass().getComponentType(), m);
4015	>	int n = r.length;
4016	>	int i = 0;
4017	>	Iterator<?> it = iterator();
4018	>	while (it.hasNext()) {
4019	>	if (i == n) {
4020	>	if (n >= MAX_ARRAY_SIZE)
4021	>	throw new OutOfMemoryError(oomeMsg);
4022	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4023	>	n = MAX_ARRAY_SIZE;
4024	>	else
4025	>	n += (n >>> 1) + 1;
4026	>	r = Arrays.copyOf(r, n);
4027	>	}
4028	>	r[i++] = (T)it.next();
4029	>	}
4030	>	if (a == r && i < n) {
4031	>	r[i] = null; // null-terminate
4032	>	return r;
4033	>	}
4034	>	return (i == n) ? r : Arrays.copyOf(r, i);
4035		}
4036	<	public void clear() {
4037	<	ConcurrentHashMap.this.clear();
4036	>
4037	>	public final int hashCode() {
4038	>	int h = 0;
4039	>	for (Iterator<?> it = iterator(); it.hasNext();)
4040	>	h += it.next().hashCode();
4041	>	return h;
4042	>	}
4043	>
4044	>	public final String toString() {
4045	>	StringBuilder sb = new StringBuilder();
4046	>	sb.append('[');
4047	>	Iterator<?> it = iterator();
4048	>	if (it.hasNext()) {
4049	>	for (;;) {
4050	>	Object e = it.next();
4051	>	sb.append(e == this ? "(this Collection)" : e);
4052	>	if (!it.hasNext())
4053	>	break;
4054	>	sb.append(',').append(' ');
4055	>	}
4056	>	}
4057	>	return sb.append(']').toString();
4058	>	}
4059	>
4060	>	public final boolean containsAll(Collection<?> c) {
4061	>	if (c != this) {
4062	>	for (Iterator<?> it = c.iterator(); it.hasNext();) {
4063	>	Object e = it.next();
4064	>	if (e == null || !contains(e))
4065	>	return false;
4066	>	}
4067	>	}
4068	>	return true;
4069		}
4070	<	public Object[] toArray() {
4071	<	Collection<K> c = new ArrayList<K>(size());
4072	<	for (K k : this)
4073	<	c.add(k);
4074	<	return c.toArray();
4070	>
4071	>	public final boolean removeAll(Collection<?> c) {
4072	>	boolean modified = false;
4073	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4074	>	if (c.contains(it.next())) {
4075	>	it.remove();
4076	>	modified = true;
4077	>	}
4078	>	}
4079	>	return modified;
4080		}
4081	<	public <T> T[] toArray(T[] a) {
4082	<	Collection<K> c = new ArrayList<K>();
4083	<	for (K k : this)
4084	<	c.add(k);
4085	<	return c.toArray(a);
4081	>
4082	>	public final boolean retainAll(Collection<?> c) {
4083	>	boolean modified = false;
4084	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4085	>	if (!c.contains(it.next())) {
4086	>	it.remove();
4087	>	modified = true;
4088	>	}
4089	>	}
4090	>	return modified;
4091		}
4092	+
4093		}
4094
4095	<	final class Values extends AbstractCollection<V> {
4096	<	public Iterator<V> iterator() {
4097	<	return new ValueIterator();
4095	>	/**
4096	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4097	>	* which additions may optionally be enabled by mapping to a
4098	>	* common value.  This class cannot be directly instantiated. See
4099	>	* {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4100	>	* {@link #newKeySet(int)}.
4101	>	*/
4102	>	public static class KeySetView<K,V> extends CHMView<K,V> implements Set<K>, java.io.Serializable {
4103	>	private static final long serialVersionUID = 7249069246763182397L;
4104	>	private final V value;
4105	>	KeySetView(ConcurrentHashMap<K, V> map, V value) {  // non-public
4106	>	super(map);
4107	>	this.value = value;
4108	>	}
4109	>
4110	>	/**
4111	>	* Returns the default mapped value for additions,
4112	>	* or {@code null} if additions are not supported.
4113	>	*
4114	>	* @return the default mapped value for additions, or {@code null}
4115	>	* if not supported.
4116	>	*/
4117	>	public V getMappedValue() { return value; }
4118	>
4119	>	// implement Set API
4120	>
4121	>	public boolean contains(Object o) { return map.containsKey(o); }
4122	>	public boolean remove(Object o)   { return map.remove(o) != null; }
4123	>
4124	>	/**
4125	>	* Returns a "weakly consistent" iterator that will never
4126	>	* throw {@link ConcurrentModificationException}, and
4127	>	* guarantees to traverse elements as they existed upon
4128	>	* construction of the iterator, and may (but is not
4129	>	* guaranteed to) reflect any modifications subsequent to
4130	>	* construction.
4131	>	*
4132	>	* @return an iterator over the keys of this map
4133	>	*/
4134	>	public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4135	>	public boolean add(K e) {
4136	>	V v;
4137	>	if ((v = value) == null)
4138	>	throw new UnsupportedOperationException();
4139	>	if (e == null)
4140	>	throw new NullPointerException();
4141	>	return map.internalPutIfAbsent(e, v) == null;
4142	>	}
4143	>	public boolean addAll(Collection<? extends K> c) {
4144	>	boolean added = false;
4145	>	V v;
4146	>	if ((v = value) == null)
4147	>	throw new UnsupportedOperationException();
4148	>	for (K e : c) {
4149	>	if (e == null)
4150	>	throw new NullPointerException();
4151	>	if (map.internalPutIfAbsent(e, v) == null)
4152	>	added = true;
4153	>	}
4154	>	return added;
4155	>	}
4156	>	public boolean equals(Object o) {
4157	>	Set<?> c;
4158	>	return ((o instanceof Set) &&
4159	>	((c = (Set<?>)o) == this ||
4160	>	(containsAll(c) && c.containsAll(this))));
4161	>	}
4162	>
4163	>	/**
4164	>	* Performs the given action for each key.
4165	>	*
4166	>	* @param action the action
4167	>	*/
4168	>	public void forEach(Action<K> action) {
4169	>	ForkJoinTasks.forEachKey
4170	>	(map, action).invoke();
4171	>	}
4172	>
4173	>	/**
4174	>	* Performs the given action for each non-null transformation
4175	>	* of each key.
4176	>	*
4177	>	* @param transformer a function returning the transformation
4178	>	* for an element, or null of there is no transformation (in
4179	>	* which case the action is not applied).
4180	>	* @param action the action
4181	>	*/
4182	>	public <U> void forEach(Fun<? super K, ? extends U> transformer,
4183	>	Action<U> action) {
4184	>	ForkJoinTasks.forEachKey
4185	>	(map, transformer, action).invoke();
4186		}
4187	<	public int size() {
4188	<	return ConcurrentHashMap.this.size();
4187	>
4188	>	/**
4189	>	* Returns a non-null result from applying the given search
4190	>	* function on each key, or null if none. Upon success,
4191	>	* further element processing is suppressed and the results of
4192	>	* any other parallel invocations of the search function are
4193	>	* ignored.
4194	>	*
4195	>	* @param searchFunction a function returning a non-null
4196	>	* result on success, else null
4197	>	* @return a non-null result from applying the given search
4198	>	* function on each key, or null if none
4199	>	*/
4200	>	public <U> U search(Fun<? super K, ? extends U> searchFunction) {
4201	>	return ForkJoinTasks.searchKeys
4202	>	(map, searchFunction).invoke();
4203		}
4204	<	public boolean contains(Object o) {
4205	<	return ConcurrentHashMap.this.containsValue(o);
4204	>
4205	>	/**
4206	>	* Returns the result of accumulating all keys using the given
4207	>	* reducer to combine values, or null if none.
4208	>	*
4209	>	* @param reducer a commutative associative combining function
4210	>	* @return the result of accumulating all keys using the given
4211	>	* reducer to combine values, or null if none
4212	>	*/
4213	>	public K reduce(BiFun<? super K, ? super K, ? extends K> reducer) {
4214	>	return ForkJoinTasks.reduceKeys
4215	>	(map, reducer).invoke();
4216		}
4217	<	public void clear() {
4218	<	ConcurrentHashMap.this.clear();
4217	>
4218	>	/**
4219	>	* Returns the result of accumulating the given transformation
4220	>	* of all keys using the given reducer to combine values, and
4221	>	* the given basis as an identity value.
4222	>	*
4223	>	* @param transformer a function returning the transformation
4224	>	* for an element
4225	>	* @param basis the identity (initial default value) for the reduction
4226	>	* @param reducer a commutative associative combining function
4227	>	* @return  the result of accumulating the given transformation
4228	>	* of all keys
4229	>	*/
4230	>	public double reduceToDouble(ObjectToDouble<? super K> transformer,
4231	>	double basis,
4232	>	DoubleByDoubleToDouble reducer) {
4233	>	return ForkJoinTasks.reduceKeysToDouble
4234	>	(map, transformer, basis, reducer).invoke();
4235		}
4236	<	public Object[] toArray() {
4237	<	Collection<V> c = new ArrayList<V>(size());
4238	<	for (V v : this)
4239	<	c.add(v);
4240	<	return c.toArray();
4236	>
4237	>
4238	>	/**
4239	>	* Returns the result of accumulating the given transformation
4240	>	* of all keys using the given reducer to combine values, and
4241	>	* the given basis as an identity value.
4242	>	*
4243	>	* @param transformer a function returning the transformation
4244	>	* for an element
4245	>	* @param basis the identity (initial default value) for the reduction
4246	>	* @param reducer a commutative associative combining function
4247	>	* @return the result of accumulating the given transformation
4248	>	* of all keys
4249	>	*/
4250	>	public long reduceToLong(ObjectToLong<? super K> transformer,
4251	>	long basis,
4252	>	LongByLongToLong reducer) {
4253	>	return ForkJoinTasks.reduceKeysToLong
4254	>	(map, transformer, basis, reducer).invoke();
4255		}
4256	<	public <T> T[] toArray(T[] a) {
4257	<	Collection<V> c = new ArrayList<V>(size());
4258	<	for (V v : this)
4259	<	c.add(v);
4260	<	return c.toArray(a);
4256	>
4257	>	/**
4258	>	* Returns the result of accumulating the given transformation
4259	>	* of all keys using the given reducer to combine values, and
4260	>	* the given basis as an identity value.
4261	>	*
4262	>	* @param transformer a function returning the transformation
4263	>	* for an element
4264	>	* @param basis the identity (initial default value) for the reduction
4265	>	* @param reducer a commutative associative combining function
4266	>	* @return the result of accumulating the given transformation
4267	>	* of all keys
4268	>	*/
4269	>	public int reduceToInt(ObjectToInt<? super K> transformer,
4270	>	int basis,
4271	>	IntByIntToInt reducer) {
4272	>	return ForkJoinTasks.reduceKeysToInt
4273	>	(map, transformer, basis, reducer).invoke();
4274		}
4275	+
4276		}
4277
4278	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4279	<	public Iterator<Map.Entry<K,V>> iterator() {
4280	<	return new EntryIterator();
4278	>	/**
4279	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4280	>	* values, in which additions are disabled. This class cannot be
4281	>	* directly instantiated. See {@link #values},
4282	>	*
4283	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4284	>	* that will never throw {@link ConcurrentModificationException},
4285	>	* and guarantees to traverse elements as they existed upon
4286	>	* construction of the iterator, and may (but is not guaranteed to)
4287	>	* reflect any modifications subsequent to construction.
4288	>	*/
4289	>	public static final class ValuesView<K,V> extends CHMView<K,V>
4290	>	implements Collection<V> {
4291	>	ValuesView(ConcurrentHashMap<K, V> map)   { super(map); }
4292	>	public final boolean contains(Object o) { return map.containsValue(o); }
4293	>	public final boolean remove(Object o) {
4294	>	if (o != null) {
4295	>	Iterator<V> it = new ValueIterator<K,V>(map);
4296	>	while (it.hasNext()) {
4297	>	if (o.equals(it.next())) {
4298	>	it.remove();
4299	>	return true;
4300	>	}
4301	>	}
4302	>	}
4303	>	return false;
4304	>	}
4305	>
4306	>	/**
4307	>	* Returns a "weakly consistent" iterator that will never
4308	>	* throw {@link ConcurrentModificationException}, and
4309	>	* guarantees to traverse elements as they existed upon
4310	>	* construction of the iterator, and may (but is not
4311	>	* guaranteed to) reflect any modifications subsequent to
4312	>	* construction.
4313	>	*
4314	>	* @return an iterator over the values of this map
4315	>	*/
4316	>	public final Iterator<V> iterator() {
4317	>	return new ValueIterator<K,V>(map);
4318		}
4319	<	public boolean contains(Object o) {
4320	<	if (!(o instanceof Map.Entry))
1226	<	return false;
1227	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
1228	<	V v = ConcurrentHashMap.this.get(e.getKey());
1229	<	return v != null && v.equals(e.getValue());
4319	>	public final boolean add(V e) {
4320	>	throw new UnsupportedOperationException();
4321		}
4322	<	public boolean remove(Object o) {
4323	<	if (!(o instanceof Map.Entry))
4324	<	return false;
4325	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4326	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4322	>	public final boolean addAll(Collection<? extends V> c) {
4323	>	throw new UnsupportedOperationException();
4324	>	}
4325	>
4326	>	/**
4327	>	* Performs the given action for each value.
4328	>	*
4329	>	* @param action the action
4330	>	*/
4331	>	public void forEach(Action<V> action) {
4332	>	ForkJoinTasks.forEachValue
4333	>	(map, action).invoke();
4334	>	}
4335	>
4336	>	/**
4337	>	* Performs the given action for each non-null transformation
4338	>	* of each value.
4339	>	*
4340	>	* @param transformer a function returning the transformation
4341	>	* for an element, or null of there is no transformation (in
4342	>	* which case the action is not applied).
4343	>	*/
4344	>	public <U> void forEach(Fun<? super V, ? extends U> transformer,
4345	>	Action<U> action) {
4346	>	ForkJoinTasks.forEachValue
4347	>	(map, transformer, action).invoke();
4348	>	}
4349	>
4350	>	/**
4351	>	* Returns a non-null result from applying the given search
4352	>	* function on each value, or null if none.  Upon success,
4353	>	* further element processing is suppressed and the results of
4354	>	* any other parallel invocations of the search function are
4355	>	* ignored.
4356	>	*
4357	>	* @param searchFunction a function returning a non-null
4358	>	* result on success, else null
4359	>	* @return a non-null result from applying the given search
4360	>	* function on each value, or null if none
4361	>	*
4362	>	*/
4363	>	public <U> U search(Fun<? super V, ? extends U> searchFunction) {
4364	>	return ForkJoinTasks.searchValues
4365	>	(map, searchFunction).invoke();
4366		}
4367	<	public int size() {
4368	<	return ConcurrentHashMap.this.size();
4367	>
4368	>	/**
4369	>	* Returns the result of accumulating all values using the
4370	>	* given reducer to combine values, or null if none.
4371	>	*
4372	>	* @param reducer a commutative associative combining function
4373	>	* @return  the result of accumulating all values
4374	>	*/
4375	>	public V reduce(BiFun<? super V, ? super V, ? extends V> reducer) {
4376	>	return ForkJoinTasks.reduceValues
4377	>	(map, reducer).invoke();
4378		}
4379	<	public void clear() {
4380	<	ConcurrentHashMap.this.clear();
4379	>
4380	>	/**
4381	>	* Returns the result of accumulating the given transformation
4382	>	* of all values using the given reducer to combine values, or
4383	>	* null if none.
4384	>	*
4385	>	* @param transformer a function returning the transformation
4386	>	* for an element, or null of there is no transformation (in
4387	>	* which case it is not combined).
4388	>	* @param reducer a commutative associative combining function
4389	>	* @return the result of accumulating the given transformation
4390	>	* of all values
4391	>	*/
4392	>	public <U> U reduce(Fun<? super V, ? extends U> transformer,
4393	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4394	>	return ForkJoinTasks.reduceValues
4395	>	(map, transformer, reducer).invoke();
4396		}
4397	<	public Object[] toArray() {
4398	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
4399	<	for (Map.Entry<K,V> e : this)
4400	<	c.add(e);
4401	<	return c.toArray();
4402	<	}
4403	<	public <T> T[] toArray(T[] a) {
4404	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
4405	<	for (Map.Entry<K,V> e : this)
4406	<	c.add(e);
4407	<	return c.toArray(a);
4397	>
4398	>	/**
4399	>	* Returns the result of accumulating the given transformation
4400	>	* of all values using the given reducer to combine values,
4401	>	* and the given basis as an identity value.
4402	>	*
4403	>	* @param transformer a function returning the transformation
4404	>	* for an element
4405	>	* @param basis the identity (initial default value) for the reduction
4406	>	* @param reducer a commutative associative combining function
4407	>	* @return the result of accumulating the given transformation
4408	>	* of all values
4409	>	*/
4410	>	public double reduceToDouble(ObjectToDouble<? super V> transformer,
4411	>	double basis,
4412	>	DoubleByDoubleToDouble reducer) {
4413	>	return ForkJoinTasks.reduceValuesToDouble
4414	>	(map, transformer, basis, reducer).invoke();
4415	>	}
4416	>
4417	>	/**
4418	>	* Returns the result of accumulating the given transformation
4419	>	* of all values using the given reducer to combine values,
4420	>	* and the given basis as an identity value.
4421	>	*
4422	>	* @param transformer a function returning the transformation
4423	>	* for an element
4424	>	* @param basis the identity (initial default value) for the reduction
4425	>	* @param reducer a commutative associative combining function
4426	>	* @return the result of accumulating the given transformation
4427	>	* of all values
4428	>	*/
4429	>	public long reduceToLong(ObjectToLong<? super V> transformer,
4430	>	long basis,
4431	>	LongByLongToLong reducer) {
4432	>	return ForkJoinTasks.reduceValuesToLong
4433	>	(map, transformer, basis, reducer).invoke();
4434	>	}
4435	>
4436	>	/**
4437	>	* Returns the result of accumulating the given transformation
4438	>	* of all values using the given reducer to combine values,
4439	>	* and the given basis as an identity value.
4440	>	*
4441	>	* @param transformer a function returning the transformation
4442	>	* for an element
4443	>	* @param basis the identity (initial default value) for the reduction
4444	>	* @param reducer a commutative associative combining function
4445	>	* @return the result of accumulating the given transformation
4446	>	* of all values
4447	>	*/
4448	>	public int reduceToInt(ObjectToInt<? super V> transformer,
4449	>	int basis,
4450	>	IntByIntToInt reducer) {
4451	>	return ForkJoinTasks.reduceValuesToInt
4452	>	(map, transformer, basis, reducer).invoke();
4453		}
4454
4455		}
4456
4457	<	/* ---------------- Serialization Support -------------- */
4457	>	/**
4458	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4459	>	* entries.  This class cannot be directly instantiated. See
4460	>	* {@link #entrySet}.
4461	>	*/
4462	>	public static final class EntrySetView<K,V> extends CHMView<K,V>
4463	>	implements Set<Map.Entry<K,V>> {
4464	>	EntrySetView(ConcurrentHashMap<K, V> map) { super(map); }
4465	>	public final boolean contains(Object o) {
4466	>	Object k, v, r; Map.Entry<?,?> e;
4467	>	return ((o instanceof Map.Entry) &&
4468	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4469	>	(r = map.get(k)) != null &&
4470	>	(v = e.getValue()) != null &&
4471	>	(v == r || v.equals(r)));
4472	>	}
4473	>	public final boolean remove(Object o) {
4474	>	Object k, v; Map.Entry<?,?> e;
4475	>	return ((o instanceof Map.Entry) &&
4476	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4477	>	(v = e.getValue()) != null &&
4478	>	map.remove(k, v));
4479	>	}
4480	>
4481	>	/**
4482	>	* Returns a "weakly consistent" iterator that will never
4483	>	* throw {@link ConcurrentModificationException}, and
4484	>	* guarantees to traverse elements as they existed upon
4485	>	* construction of the iterator, and may (but is not
4486	>	* guaranteed to) reflect any modifications subsequent to
4487	>	* construction.
4488	>	*
4489	>	* @return an iterator over the entries of this map
4490	>	*/
4491	>	public final Iterator<Map.Entry<K,V>> iterator() {
4492	>	return new EntryIterator<K,V>(map);
4493	>	}
4494	>
4495	>	public final boolean add(Entry<K,V> e) {
4496	>	K key = e.getKey();
4497	>	V value = e.getValue();
4498	>	if (key == null || value == null)
4499	>	throw new NullPointerException();
4500	>	return map.internalPut(key, value) == null;
4501	>	}
4502	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4503	>	boolean added = false;
4504	>	for (Entry<K,V> e : c) {
4505	>	if (add(e))
4506	>	added = true;
4507	>	}
4508	>	return added;
4509	>	}
4510	>	public boolean equals(Object o) {
4511	>	Set<?> c;
4512	>	return ((o instanceof Set) &&
4513	>	((c = (Set<?>)o) == this ||
4514	>	(containsAll(c) && c.containsAll(this))));
4515	>	}
4516	>
4517	>	/**
4518	>	* Performs the given action for each entry.
4519	>	*
4520	>	* @param action the action
4521	>	*/
4522	>	public void forEach(Action<Map.Entry<K,V>> action) {
4523	>	ForkJoinTasks.forEachEntry
4524	>	(map, action).invoke();
4525	>	}
4526	>
4527	>	/**
4528	>	* Performs the given action for each non-null transformation
4529	>	* of each entry.
4530	>	*
4531	>	* @param transformer a function returning the transformation
4532	>	* for an element, or null of there is no transformation (in
4533	>	* which case the action is not applied).
4534	>	* @param action the action
4535	>	*/
4536	>	public <U> void forEach(Fun<Map.Entry<K,V>, ? extends U> transformer,
4537	>	Action<U> action) {
4538	>	ForkJoinTasks.forEachEntry
4539	>	(map, transformer, action).invoke();
4540	>	}
4541	>
4542	>	/**
4543	>	* Returns a non-null result from applying the given search
4544	>	* function on each entry, or null if none.  Upon success,
4545	>	* further element processing is suppressed and the results of
4546	>	* any other parallel invocations of the search function are
4547	>	* ignored.
4548	>	*
4549	>	* @param searchFunction a function returning a non-null
4550	>	* result on success, else null
4551	>	* @return a non-null result from applying the given search
4552	>	* function on each entry, or null if none
4553	>	*/
4554	>	public <U> U search(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4555	>	return ForkJoinTasks.searchEntries
4556	>	(map, searchFunction).invoke();
4557	>	}
4558	>
4559	>	/**
4560	>	* Returns the result of accumulating all entries using the
4561	>	* given reducer to combine values, or null if none.
4562	>	*
4563	>	* @param reducer a commutative associative combining function
4564	>	* @return the result of accumulating all entries
4565	>	*/
4566	>	public Map.Entry<K,V> reduce(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4567	>	return ForkJoinTasks.reduceEntries
4568	>	(map, reducer).invoke();
4569	>	}
4570	>
4571	>	/**
4572	>	* Returns the result of accumulating the given transformation
4573	>	* of all entries using the given reducer to combine values,
4574	>	* or null if none.
4575	>	*
4576	>	* @param transformer a function returning the transformation
4577	>	* for an element, or null of there is no transformation (in
4578	>	* which case it is not combined).
4579	>	* @param reducer a commutative associative combining function
4580	>	* @return the result of accumulating the given transformation
4581	>	* of all entries
4582	>	*/
4583	>	public <U> U reduce(Fun<Map.Entry<K,V>, ? extends U> transformer,
4584	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4585	>	return ForkJoinTasks.reduceEntries
4586	>	(map, transformer, reducer).invoke();
4587	>	}
4588	>
4589	>	/**
4590	>	* Returns the result of accumulating the given transformation
4591	>	* of all entries using the given reducer to combine values,
4592	>	* and the given basis as an identity value.
4593	>	*
4594	>	* @param transformer a function returning the transformation
4595	>	* for an element
4596	>	* @param basis the identity (initial default value) for the reduction
4597	>	* @param reducer a commutative associative combining function
4598	>	* @return the result of accumulating the given transformation
4599	>	* of all entries
4600	>	*/
4601	>	public double reduceToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
4602	>	double basis,
4603	>	DoubleByDoubleToDouble reducer) {
4604	>	return ForkJoinTasks.reduceEntriesToDouble
4605	>	(map, transformer, basis, reducer).invoke();
4606	>	}
4607	>
4608	>	/**
4609	>	* Returns the result of accumulating the given transformation
4610	>	* of all entries using the given reducer to combine values,
4611	>	* and the given basis as an identity value.
4612	>	*
4613	>	* @param transformer a function returning the transformation
4614	>	* for an element
4615	>	* @param basis the identity (initial default value) for the reduction
4616	>	* @param reducer a commutative associative combining function
4617	>	* @return  the result of accumulating the given transformation
4618	>	* of all entries
4619	>	*/
4620	>	public long reduceToLong(ObjectToLong<Map.Entry<K,V>> transformer,
4621	>	long basis,
4622	>	LongByLongToLong reducer) {
4623	>	return ForkJoinTasks.reduceEntriesToLong
4624	>	(map, transformer, basis, reducer).invoke();
4625	>	}
4626	>
4627	>	/**
4628	>	* Returns the result of accumulating the given transformation
4629	>	* of all entries using the given reducer to combine values,
4630	>	* and the given basis as an identity value.
4631	>	*
4632	>	* @param transformer a function returning the transformation
4633	>	* for an element
4634	>	* @param basis the identity (initial default value) for the reduction
4635	>	* @param reducer a commutative associative combining function
4636	>	* @return the result of accumulating the given transformation
4637	>	* of all entries
4638	>	*/
4639	>	public int reduceToInt(ObjectToInt<Map.Entry<K,V>> transformer,
4640	>	int basis,
4641	>	IntByIntToInt reducer) {
4642	>	return ForkJoinTasks.reduceEntriesToInt
4643	>	(map, transformer, basis, reducer).invoke();
4644	>	}
4645	>
4646	>	}
4647	>
4648	>	// ---------------------------------------------------------------------
4649
4650		/**
4651	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
4652	<	* stream (i.e., serialize it).
4653	<	* @param s the stream
4654	<	* @serialData
4655	<	* the key (Object) and value (Object)
4656	<	* for each key-value mapping, followed by a null pair.
4657	<	* The key-value mappings are emitted in no particular order.
4651	>	* Predefined tasks for performing bulk parallel operations on
4652	>	* ConcurrentHashMaps. These tasks follow the forms and rules used
4653	>	* for bulk operations. Each method has the same name, but returns
4654	>	* a task rather than invoking it. These methods may be useful in
4655	>	* custom applications such as submitting a task without waiting
4656	>	* for completion, using a custom pool, or combining with other
4657	>	* tasks.
4658		*/
4659	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4660	<	s.defaultWriteObject();
4659	>	public static class ForkJoinTasks {
4660	>	private ForkJoinTasks() {}
4661
4662	<	for (int k = 0; k < segments.length; ++k) {
4663	<	Segment<K,V> seg = segments[k];
4664	<	seg.lock();
4665	<	try {
4666	<	HashEntry<K,V>[] tab = seg.table;
4667	<	for (int i = 0; i < tab.length; ++i) {
4668	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
4669	<	s.writeObject(e.key);
4670	<	s.writeObject(e.value);
4671	<	}
4662	>	/**
4663	>	* Returns a task that when invoked, performs the given
4664	>	* action for each (key, value)
4665	>	*
4666	>	* @param map the map
4667	>	* @param action the action
4668	>	* @return the task
4669	>	*/
4670	>	public static <K,V> ForkJoinTask<Void> forEach
4671	>	(ConcurrentHashMap<K,V> map,
4672	>	BiAction<K,V> action) {
4673	>	if (action == null) throw new NullPointerException();
4674	>	return new ForEachMappingTask<K,V>(map, null, -1, null, action);
4675	>	}
4676	>
4677	>	/**
4678	>	* Returns a task that when invoked, performs the given
4679	>	* action for each non-null transformation of each (key, value)
4680	>	*
4681	>	* @param map the map
4682	>	* @param transformer a function returning the transformation
4683	>	* for an element, or null if there is no transformation (in
4684	>	* which case the action is not applied)
4685	>	* @param action the action
4686	>	* @return the task
4687	>	*/
4688	>	public static <K,V,U> ForkJoinTask<Void> forEach
4689	>	(ConcurrentHashMap<K,V> map,
4690	>	BiFun<? super K, ? super V, ? extends U> transformer,
4691	>	Action<U> action) {
4692	>	if (transformer == null || action == null)
4693	>	throw new NullPointerException();
4694	>	return new ForEachTransformedMappingTask<K,V,U>
4695	>	(map, null, -1, null, transformer, action);
4696	>	}
4697	>
4698	>	/**
4699	>	* Returns a task that when invoked, returns a non-null result
4700	>	* from applying the given search function on each (key,
4701	>	* value), or null if none. Upon success, further element
4702	>	* processing is suppressed and the results of any other
4703	>	* parallel invocations of the search function are ignored.
4704	>	*
4705	>	* @param map the map
4706	>	* @param searchFunction a function returning a non-null
4707	>	* result on success, else null
4708	>	* @return the task
4709	>	*/
4710	>	public static <K,V,U> ForkJoinTask<U> search
4711	>	(ConcurrentHashMap<K,V> map,
4712	>	BiFun<? super K, ? super V, ? extends U> searchFunction) {
4713	>	if (searchFunction == null) throw new NullPointerException();
4714	>	return new SearchMappingsTask<K,V,U>
4715	>	(map, null, -1, null, searchFunction,
4716	>	new AtomicReference<U>());
4717	>	}
4718	>
4719	>	/**
4720	>	* Returns a task that when invoked, returns the result of
4721	>	* accumulating the given transformation of all (key, value) pairs
4722	>	* using the given reducer to combine values, or null if none.
4723	>	*
4724	>	* @param map the map
4725	>	* @param transformer a function returning the transformation
4726	>	* for an element, or null if there is no transformation (in
4727	>	* which case it is not combined).
4728	>	* @param reducer a commutative associative combining function
4729	>	* @return the task
4730	>	*/
4731	>	public static <K,V,U> ForkJoinTask<U> reduce
4732	>	(ConcurrentHashMap<K,V> map,
4733	>	BiFun<? super K, ? super V, ? extends U> transformer,
4734	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4735	>	if (transformer == null || reducer == null)
4736	>	throw new NullPointerException();
4737	>	return new MapReduceMappingsTask<K,V,U>
4738	>	(map, null, -1, null, transformer, reducer);
4739	>	}
4740	>
4741	>	/**
4742	>	* Returns a task that when invoked, returns the result of
4743	>	* accumulating the given transformation of all (key, value) pairs
4744	>	* using the given reducer to combine values, and the given
4745	>	* basis as an identity value.
4746	>	*
4747	>	* @param map the map
4748	>	* @param transformer a function returning the transformation
4749	>	* for an element
4750	>	* @param basis the identity (initial default value) for the reduction
4751	>	* @param reducer a commutative associative combining function
4752	>	* @return the task
4753	>	*/
4754	>	public static <K,V> ForkJoinTask<Double> reduceToDouble
4755	>	(ConcurrentHashMap<K,V> map,
4756	>	ObjectByObjectToDouble<? super K, ? super V> transformer,
4757	>	double basis,
4758	>	DoubleByDoubleToDouble reducer) {
4759	>	if (transformer == null || reducer == null)
4760	>	throw new NullPointerException();
4761	>	return new MapReduceMappingsToDoubleTask<K,V>
4762	>	(map, null, -1, null, transformer, basis, reducer);
4763	>	}
4764	>
4765	>	/**
4766	>	* Returns a task that when invoked, returns the result of
4767	>	* accumulating the given transformation of all (key, value) pairs
4768	>	* using the given reducer to combine values, and the given
4769	>	* basis as an identity value.
4770	>	*
4771	>	* @param map the map
4772	>	* @param transformer a function returning the transformation
4773	>	* for an element
4774	>	* @param basis the identity (initial default value) for the reduction
4775	>	* @param reducer a commutative associative combining function
4776	>	* @return the task
4777	>	*/
4778	>	public static <K,V> ForkJoinTask<Long> reduceToLong
4779	>	(ConcurrentHashMap<K,V> map,
4780	>	ObjectByObjectToLong<? super K, ? super V> transformer,
4781	>	long basis,
4782	>	LongByLongToLong reducer) {
4783	>	if (transformer == null || reducer == null)
4784	>	throw new NullPointerException();
4785	>	return new MapReduceMappingsToLongTask<K,V>
4786	>	(map, null, -1, null, transformer, basis, reducer);
4787	>	}
4788	>
4789	>	/**
4790	>	* Returns a task that when invoked, returns the result of
4791	>	* accumulating the given transformation of all (key, value) pairs
4792	>	* using the given reducer to combine values, and the given
4793	>	* basis as an identity value.
4794	>	*
4795	>	* @param transformer a function returning the transformation
4796	>	* for an element
4797	>	* @param basis the identity (initial default value) for the reduction
4798	>	* @param reducer a commutative associative combining function
4799	>	* @return the task
4800	>	*/
4801	>	public static <K,V> ForkJoinTask<Integer> reduceToInt
4802	>	(ConcurrentHashMap<K,V> map,
4803	>	ObjectByObjectToInt<? super K, ? super V> transformer,
4804	>	int basis,
4805	>	IntByIntToInt reducer) {
4806	>	if (transformer == null || reducer == null)
4807	>	throw new NullPointerException();
4808	>	return new MapReduceMappingsToIntTask<K,V>
4809	>	(map, null, -1, null, transformer, basis, reducer);
4810	>	}
4811	>
4812	>	/**
4813	>	* Returns a task that when invoked, performs the given action
4814	>	* for each key.
4815	>	*
4816	>	* @param map the map
4817	>	* @param action the action
4818	>	* @return the task
4819	>	*/
4820	>	public static <K,V> ForkJoinTask<Void> forEachKey
4821	>	(ConcurrentHashMap<K,V> map,
4822	>	Action<K> action) {
4823	>	if (action == null) throw new NullPointerException();
4824	>	return new ForEachKeyTask<K,V>(map, null, -1, null, action);
4825	>	}
4826	>
4827	>	/**
4828	>	* Returns a task that when invoked, performs the given action
4829	>	* for each non-null transformation of each key.
4830	>	*
4831	>	* @param map the map
4832	>	* @param transformer a function returning the transformation
4833	>	* for an element, or null if there is no transformation (in
4834	>	* which case the action is not applied)
4835	>	* @param action the action
4836	>	* @return the task
4837	>	*/
4838	>	public static <K,V,U> ForkJoinTask<Void> forEachKey
4839	>	(ConcurrentHashMap<K,V> map,
4840	>	Fun<? super K, ? extends U> transformer,
4841	>	Action<U> action) {
4842	>	if (transformer == null || action == null)
4843	>	throw new NullPointerException();
4844	>	return new ForEachTransformedKeyTask<K,V,U>
4845	>	(map, null, -1, null, transformer, action);
4846	>	}
4847	>
4848	>	/**
4849	>	* Returns a task that when invoked, returns a non-null result
4850	>	* from applying the given search function on each key, or
4851	>	* null if none.  Upon success, further element processing is
4852	>	* suppressed and the results of any other parallel
4853	>	* invocations of the search function are ignored.
4854	>	*
4855	>	* @param map the map
4856	>	* @param searchFunction a function returning a non-null
4857	>	* result on success, else null
4858	>	* @return the task
4859	>	*/
4860	>	public static <K,V,U> ForkJoinTask<U> searchKeys
4861	>	(ConcurrentHashMap<K,V> map,
4862	>	Fun<? super K, ? extends U> searchFunction) {
4863	>	if (searchFunction == null) throw new NullPointerException();
4864	>	return new SearchKeysTask<K,V,U>
4865	>	(map, null, -1, null, searchFunction,
4866	>	new AtomicReference<U>());
4867	>	}
4868	>
4869	>	/**
4870	>	* Returns a task that when invoked, returns the result of
4871	>	* accumulating all keys using the given reducer to combine
4872	>	* values, or null if none.
4873	>	*
4874	>	* @param map the map
4875	>	* @param reducer a commutative associative combining function
4876	>	* @return the task
4877	>	*/
4878	>	public static <K,V> ForkJoinTask<K> reduceKeys
4879	>	(ConcurrentHashMap<K,V> map,
4880	>	BiFun<? super K, ? super K, ? extends K> reducer) {
4881	>	if (reducer == null) throw new NullPointerException();
4882	>	return new ReduceKeysTask<K,V>
4883	>	(map, null, -1, null, reducer);
4884	>	}
4885	>
4886	>	/**
4887	>	* Returns a task that when invoked, returns the result of
4888	>	* accumulating the given transformation of all keys using the given
4889	>	* reducer to combine values, or null if none.
4890	>	*
4891	>	* @param map the map
4892	>	* @param transformer a function returning the transformation
4893	>	* for an element, or null if there is no transformation (in
4894	>	* which case it is not combined).
4895	>	* @param reducer a commutative associative combining function
4896	>	* @return the task
4897	>	*/
4898	>	public static <K,V,U> ForkJoinTask<U> reduceKeys
4899	>	(ConcurrentHashMap<K,V> map,
4900	>	Fun<? super K, ? extends U> transformer,
4901	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4902	>	if (transformer == null || reducer == null)
4903	>	throw new NullPointerException();
4904	>	return new MapReduceKeysTask<K,V,U>
4905	>	(map, null, -1, null, transformer, reducer);
4906	>	}
4907	>
4908	>	/**
4909	>	* Returns a task that when invoked, returns the result of
4910	>	* accumulating the given transformation of all keys using the given
4911	>	* reducer to combine values, and the given basis as an
4912	>	* identity value.
4913	>	*
4914	>	* @param map the map
4915	>	* @param transformer a function returning the transformation
4916	>	* for an element
4917	>	* @param basis the identity (initial default value) for the reduction
4918	>	* @param reducer a commutative associative combining function
4919	>	* @return the task
4920	>	*/
4921	>	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
4922	>	(ConcurrentHashMap<K,V> map,
4923	>	ObjectToDouble<? super K> transformer,
4924	>	double basis,
4925	>	DoubleByDoubleToDouble reducer) {
4926	>	if (transformer == null || reducer == null)
4927	>	throw new NullPointerException();
4928	>	return new MapReduceKeysToDoubleTask<K,V>
4929	>	(map, null, -1, null, transformer, basis, reducer);
4930	>	}
4931	>
4932	>	/**
4933	>	* Returns a task that when invoked, returns the result of
4934	>	* accumulating the given transformation of all keys using the given
4935	>	* reducer to combine values, and the given basis as an
4936	>	* identity value.
4937	>	*
4938	>	* @param map the map
4939	>	* @param transformer a function returning the transformation
4940	>	* for an element
4941	>	* @param basis the identity (initial default value) for the reduction
4942	>	* @param reducer a commutative associative combining function
4943	>	* @return the task
4944	>	*/
4945	>	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
4946	>	(ConcurrentHashMap<K,V> map,
4947	>	ObjectToLong<? super K> transformer,
4948	>	long basis,
4949	>	LongByLongToLong reducer) {
4950	>	if (transformer == null || reducer == null)
4951	>	throw new NullPointerException();
4952	>	return new MapReduceKeysToLongTask<K,V>
4953	>	(map, null, -1, null, transformer, basis, reducer);
4954	>	}
4955	>
4956	>	/**
4957	>	* Returns a task that when invoked, returns the result of
4958	>	* accumulating the given transformation of all keys using the given
4959	>	* reducer to combine values, and the given basis as an
4960	>	* identity value.
4961	>	*
4962	>	* @param map the map
4963	>	* @param transformer a function returning the transformation
4964	>	* for an element
4965	>	* @param basis the identity (initial default value) for the reduction
4966	>	* @param reducer a commutative associative combining function
4967	>	* @return the task
4968	>	*/
4969	>	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
4970	>	(ConcurrentHashMap<K,V> map,
4971	>	ObjectToInt<? super K> transformer,
4972	>	int basis,
4973	>	IntByIntToInt reducer) {
4974	>	if (transformer == null || reducer == null)
4975	>	throw new NullPointerException();
4976	>	return new MapReduceKeysToIntTask<K,V>
4977	>	(map, null, -1, null, transformer, basis, reducer);
4978	>	}
4979	>
4980	>	/**
4981	>	* Returns a task that when invoked, performs the given action
4982	>	* for each value.
4983	>	*
4984	>	* @param map the map
4985	>	* @param action the action
4986	>	*/
4987	>	public static <K,V> ForkJoinTask<Void> forEachValue
4988	>	(ConcurrentHashMap<K,V> map,
4989	>	Action<V> action) {
4990	>	if (action == null) throw new NullPointerException();
4991	>	return new ForEachValueTask<K,V>(map, null, -1, null, action);
4992	>	}
4993	>
4994	>	/**
4995	>	* Returns a task that when invoked, performs the given action
4996	>	* for each non-null transformation of each value.
4997	>	*
4998	>	* @param map the map
4999	>	* @param transformer a function returning the transformation
5000	>	* for an element, or null if there is no transformation (in
5001	>	* which case the action is not applied)
5002	>	* @param action the action
5003	>	*/
5004	>	public static <K,V,U> ForkJoinTask<Void> forEachValue
5005	>	(ConcurrentHashMap<K,V> map,
5006	>	Fun<? super V, ? extends U> transformer,
5007	>	Action<U> action) {
5008	>	if (transformer == null || action == null)
5009	>	throw new NullPointerException();
5010	>	return new ForEachTransformedValueTask<K,V,U>
5011	>	(map, null, -1, null, transformer, action);
5012	>	}
5013	>
5014	>	/**
5015	>	* Returns a task that when invoked, returns a non-null result
5016	>	* from applying the given search function on each value, or
5017	>	* null if none.  Upon success, further element processing is
5018	>	* suppressed and the results of any other parallel
5019	>	* invocations of the search function are ignored.
5020	>	*
5021	>	* @param map the map
5022	>	* @param searchFunction a function returning a non-null
5023	>	* result on success, else null
5024	>	* @return the task
5025	>	*/
5026	>	public static <K,V,U> ForkJoinTask<U> searchValues
5027	>	(ConcurrentHashMap<K,V> map,
5028	>	Fun<? super V, ? extends U> searchFunction) {
5029	>	if (searchFunction == null) throw new NullPointerException();
5030	>	return new SearchValuesTask<K,V,U>
5031	>	(map, null, -1, null, searchFunction,
5032	>	new AtomicReference<U>());
5033	>	}
5034	>
5035	>	/**
5036	>	* Returns a task that when invoked, returns the result of
5037	>	* accumulating all values using the given reducer to combine
5038	>	* values, or null if none.
5039	>	*
5040	>	* @param map the map
5041	>	* @param reducer a commutative associative combining function
5042	>	* @return the task
5043	>	*/
5044	>	public static <K,V> ForkJoinTask<V> reduceValues
5045	>	(ConcurrentHashMap<K,V> map,
5046	>	BiFun<? super V, ? super V, ? extends V> reducer) {
5047	>	if (reducer == null) throw new NullPointerException();
5048	>	return new ReduceValuesTask<K,V>
5049	>	(map, null, -1, null, reducer);
5050	>	}
5051	>
5052	>	/**
5053	>	* Returns a task that when invoked, returns the result of
5054	>	* accumulating the given transformation of all values using the
5055	>	* given reducer to combine values, or null if none.
5056	>	*
5057	>	* @param map the map
5058	>	* @param transformer a function returning the transformation
5059	>	* for an element, or null if there is no transformation (in
5060	>	* which case it is not combined).
5061	>	* @param reducer a commutative associative combining function
5062	>	* @return the task
5063	>	*/
5064	>	public static <K,V,U> ForkJoinTask<U> reduceValues
5065	>	(ConcurrentHashMap<K,V> map,
5066	>	Fun<? super V, ? extends U> transformer,
5067	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5068	>	if (transformer == null || reducer == null)
5069	>	throw new NullPointerException();
5070	>	return new MapReduceValuesTask<K,V,U>
5071	>	(map, null, -1, null, transformer, reducer);
5072	>	}
5073	>
5074	>	/**
5075	>	* Returns a task that when invoked, returns the result of
5076	>	* accumulating the given transformation of all values using the
5077	>	* given reducer to combine values, and the given basis as an
5078	>	* identity value.
5079	>	*
5080	>	* @param map the map
5081	>	* @param transformer a function returning the transformation
5082	>	* for an element
5083	>	* @param basis the identity (initial default value) for the reduction
5084	>	* @param reducer a commutative associative combining function
5085	>	* @return the task
5086	>	*/
5087	>	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5088	>	(ConcurrentHashMap<K,V> map,
5089	>	ObjectToDouble<? super V> transformer,
5090	>	double basis,
5091	>	DoubleByDoubleToDouble reducer) {
5092	>	if (transformer == null || reducer == null)
5093	>	throw new NullPointerException();
5094	>	return new MapReduceValuesToDoubleTask<K,V>
5095	>	(map, null, -1, null, transformer, basis, reducer);
5096	>	}
5097	>
5098	>	/**
5099	>	* Returns a task that when invoked, returns the result of
5100	>	* accumulating the given transformation of all values using the
5101	>	* given reducer to combine values, and the given basis as an
5102	>	* identity value.
5103	>	*
5104	>	* @param map the map
5105	>	* @param transformer a function returning the transformation
5106	>	* for an element
5107	>	* @param basis the identity (initial default value) for the reduction
5108	>	* @param reducer a commutative associative combining function
5109	>	* @return the task
5110	>	*/
5111	>	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5112	>	(ConcurrentHashMap<K,V> map,
5113	>	ObjectToLong<? super V> transformer,
5114	>	long basis,
5115	>	LongByLongToLong reducer) {
5116	>	if (transformer == null || reducer == null)
5117	>	throw new NullPointerException();
5118	>	return new MapReduceValuesToLongTask<K,V>
5119	>	(map, null, -1, null, transformer, basis, reducer);
5120	>	}
5121	>
5122	>	/**
5123	>	* Returns a task that when invoked, returns the result of
5124	>	* accumulating the given transformation of all values using the
5125	>	* given reducer to combine values, and the given basis as an
5126	>	* identity value.
5127	>	*
5128	>	* @param map the map
5129	>	* @param transformer a function returning the transformation
5130	>	* for an element
5131	>	* @param basis the identity (initial default value) for the reduction
5132	>	* @param reducer a commutative associative combining function
5133	>	* @return the task
5134	>	*/
5135	>	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5136	>	(ConcurrentHashMap<K,V> map,
5137	>	ObjectToInt<? super V> transformer,
5138	>	int basis,
5139	>	IntByIntToInt reducer) {
5140	>	if (transformer == null || reducer == null)
5141	>	throw new NullPointerException();
5142	>	return new MapReduceValuesToIntTask<K,V>
5143	>	(map, null, -1, null, transformer, basis, reducer);
5144	>	}
5145	>
5146	>	/**
5147	>	* Returns a task that when invoked, perform the given action
5148	>	* for each entry.
5149	>	*
5150	>	* @param map the map
5151	>	* @param action the action
5152	>	*/
5153	>	public static <K,V> ForkJoinTask<Void> forEachEntry
5154	>	(ConcurrentHashMap<K,V> map,
5155	>	Action<Map.Entry<K,V>> action) {
5156	>	if (action == null) throw new NullPointerException();
5157	>	return new ForEachEntryTask<K,V>(map, null, -1, null, action);
5158	>	}
5159	>
5160	>	/**
5161	>	* Returns a task that when invoked, perform the given action
5162	>	* for each non-null transformation of each entry.
5163	>	*
5164	>	* @param map the map
5165	>	* @param transformer a function returning the transformation
5166	>	* for an element, or null if there is no transformation (in
5167	>	* which case the action is not applied)
5168	>	* @param action the action
5169	>	*/
5170	>	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5171	>	(ConcurrentHashMap<K,V> map,
5172	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5173	>	Action<U> action) {
5174	>	if (transformer == null || action == null)
5175	>	throw new NullPointerException();
5176	>	return new ForEachTransformedEntryTask<K,V,U>
5177	>	(map, null, -1, null, transformer, action);
5178	>	}
5179	>
5180	>	/**
5181	>	* Returns a task that when invoked, returns a non-null result
5182	>	* from applying the given search function on each entry, or
5183	>	* null if none.  Upon success, further element processing is
5184	>	* suppressed and the results of any other parallel
5185	>	* invocations of the search function are ignored.
5186	>	*
5187	>	* @param map the map
5188	>	* @param searchFunction a function returning a non-null
5189	>	* result on success, else null
5190	>	* @return the task
5191	>	*/
5192	>	public static <K,V,U> ForkJoinTask<U> searchEntries
5193	>	(ConcurrentHashMap<K,V> map,
5194	>	Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
5195	>	if (searchFunction == null) throw new NullPointerException();
5196	>	return new SearchEntriesTask<K,V,U>
5197	>	(map, null, -1, null, searchFunction,
5198	>	new AtomicReference<U>());
5199	>	}
5200	>
5201	>	/**
5202	>	* Returns a task that when invoked, returns the result of
5203	>	* accumulating all entries using the given reducer to combine
5204	>	* values, or null if none.
5205	>	*
5206	>	* @param map the map
5207	>	* @param reducer a commutative associative combining function
5208	>	* @return the task
5209	>	*/
5210	>	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5211	>	(ConcurrentHashMap<K,V> map,
5212	>	BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5213	>	if (reducer == null) throw new NullPointerException();
5214	>	return new ReduceEntriesTask<K,V>
5215	>	(map, null, -1, null, reducer);
5216	>	}
5217	>
5218	>	/**
5219	>	* Returns a task that when invoked, returns the result of
5220	>	* accumulating the given transformation of all entries using the
5221	>	* given reducer to combine values, or null if none.
5222	>	*
5223	>	* @param map the map
5224	>	* @param transformer a function returning the transformation
5225	>	* for an element, or null if there is no transformation (in
5226	>	* which case it is not combined).
5227	>	* @param reducer a commutative associative combining function
5228	>	* @return the task
5229	>	*/
5230	>	public static <K,V,U> ForkJoinTask<U> reduceEntries
5231	>	(ConcurrentHashMap<K,V> map,
5232	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5233	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5234	>	if (transformer == null || reducer == null)
5235	>	throw new NullPointerException();
5236	>	return new MapReduceEntriesTask<K,V,U>
5237	>	(map, null, -1, null, transformer, reducer);
5238	>	}
5239	>
5240	>	/**
5241	>	* Returns a task that when invoked, returns the result of
5242	>	* accumulating the given transformation of all entries using the
5243	>	* given reducer to combine values, and the given basis as an
5244	>	* identity value.
5245	>	*
5246	>	* @param map the map
5247	>	* @param transformer a function returning the transformation
5248	>	* for an element
5249	>	* @param basis the identity (initial default value) for the reduction
5250	>	* @param reducer a commutative associative combining function
5251	>	* @return the task
5252	>	*/
5253	>	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5254	>	(ConcurrentHashMap<K,V> map,
5255	>	ObjectToDouble<Map.Entry<K,V>> transformer,
5256	>	double basis,
5257	>	DoubleByDoubleToDouble reducer) {
5258	>	if (transformer == null || reducer == null)
5259	>	throw new NullPointerException();
5260	>	return new MapReduceEntriesToDoubleTask<K,V>
5261	>	(map, null, -1, null, transformer, basis, reducer);
5262	>	}
5263	>
5264	>	/**
5265	>	* Returns a task that when invoked, returns the result of
5266	>	* accumulating the given transformation of all entries using the
5267	>	* given reducer to combine values, and the given basis as an
5268	>	* identity value.
5269	>	*
5270	>	* @param map the map
5271	>	* @param transformer a function returning the transformation
5272	>	* for an element
5273	>	* @param basis the identity (initial default value) for the reduction
5274	>	* @param reducer a commutative associative combining function
5275	>	* @return the task
5276	>	*/
5277	>	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5278	>	(ConcurrentHashMap<K,V> map,
5279	>	ObjectToLong<Map.Entry<K,V>> transformer,
5280	>	long basis,
5281	>	LongByLongToLong reducer) {
5282	>	if (transformer == null || reducer == null)
5283	>	throw new NullPointerException();
5284	>	return new MapReduceEntriesToLongTask<K,V>
5285	>	(map, null, -1, null, transformer, basis, reducer);
5286	>	}
5287	>
5288	>	/**
5289	>	* Returns a task that when invoked, returns the result of
5290	>	* accumulating the given transformation of all entries using the
5291	>	* given reducer to combine values, and the given basis as an
5292	>	* identity value.
5293	>	*
5294	>	* @param map the map
5295	>	* @param transformer a function returning the transformation
5296	>	* for an element
5297	>	* @param basis the identity (initial default value) for the reduction
5298	>	* @param reducer a commutative associative combining function
5299	>	* @return the task
5300	>	*/
5301	>	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5302	>	(ConcurrentHashMap<K,V> map,
5303	>	ObjectToInt<Map.Entry<K,V>> transformer,
5304	>	int basis,
5305	>	IntByIntToInt reducer) {
5306	>	if (transformer == null || reducer == null)
5307	>	throw new NullPointerException();
5308	>	return new MapReduceEntriesToIntTask<K,V>
5309	>	(map, null, -1, null, transformer, basis, reducer);
5310	>	}
5311	>	}
5312	>
5313	>	// -------------------------------------------------------
5314	>
5315	>	/**
5316	>	* Base for FJ tasks for bulk operations. This adds a variant of
5317	>	* CountedCompleters and some split and merge bookkeeping to
5318	>	* iterator functionality. The forEach and reduce methods are
5319	>	* similar to those illustrated in CountedCompleter documentation,
5320	>	* except that bottom-up reduction completions perform them within
5321	>	* their compute methods. The search methods are like forEach
5322	>	* except they continually poll for success and exit early.  Also,
5323	>	* exceptions are handled in a simpler manner, by just trying to
5324	>	* complete root task exceptionally.
5325	>	*/
5326	>	@SuppressWarnings("serial") static abstract class BulkTask<K,V,R> extends Traverser<K,V,R> {
5327	>	final BulkTask<K,V,?> parent;  // completion target
5328	>	int batch;                     // split control; -1 for unknown
5329	>	int pending;                   // completion control
5330	>
5331	>	BulkTask(ConcurrentHashMap<K,V> map, BulkTask<K,V,?> parent,
5332	>	int batch) {
5333	>	super(map);
5334	>	this.parent = parent;
5335	>	this.batch = batch;
5336	>	if (parent != null && map != null) { // split parent
5337	>	Node[] t;
5338	>	if ((t = parent.tab) == null &&
5339	>	(t = parent.tab = map.table) != null)
5340	>	parent.baseLimit = parent.baseSize = t.length;
5341	>	this.tab = t;
5342	>	this.baseSize = parent.baseSize;
5343	>	int hi = this.baseLimit = parent.baseLimit;
5344	>	parent.baseLimit = this.index = this.baseIndex =
5345	>	(hi + parent.baseIndex + 1) >>> 1;
5346	>	}
5347	>	}
5348	>
5349	>	/**
5350	>	* Forces root task to complete.
5351	>	* @param ex if null, complete normally, else exceptionally
5352	>	* @return false to simplify use
5353	>	*/
5354	>	final boolean tryCompleteComputation(Throwable ex) {
5355	>	for (BulkTask<K,V,?> a = this;;) {
5356	>	BulkTask<K,V,?> p = a.parent;
5357	>	if (p == null) {
5358	>	if (ex != null)
5359	>	a.completeExceptionally(ex);
5360	>	else
5361	>	a.quietlyComplete();
5362	>	return false;
5363		}
5364	<	} finally {
5365	<	seg.unlock();
5364	>	a = p;
5365	>	}
5366	>	}
5367	>
5368	>	/**
5369	>	* Version of tryCompleteComputation for function screening checks
5370	>	*/
5371	>	final boolean abortOnNullFunction() {
5372	>	return tryCompleteComputation(new Error("Unexpected null function"));
5373	>	}
5374	>
5375	>	// utilities
5376	>
5377	>	/** CompareAndSet pending count */
5378	>	final boolean casPending(int cmp, int val) {
5379	>	return U.compareAndSwapInt(this, PENDING, cmp, val);
5380	>	}
5381	>
5382	>	/**
5383	>	* Returns approx exp2 of the number of times (minus one) to
5384	>	* split task by two before executing leaf action. This value
5385	>	* is faster to compute and more convenient to use as a guide
5386	>	* to splitting than is the depth, since it is used while
5387	>	* dividing by two anyway.
5388	>	*/
5389	>	final int batch() {
5390	>	ConcurrentHashMap<K, V> m; int b; Node[] t;  ForkJoinPool pool;
5391	>	if ((b = batch) < 0 && (m = map) != null) { // force initialization
5392	>	if ((t = tab) == null && (t = tab = m.table) != null)
5393	>	baseLimit = baseSize = t.length;
5394	>	if (t != null) {
5395	>	long n = m.counter.sum();
5396	>	int par = ((pool = getPool()) == null) ?
5397	>	ForkJoinPool.getCommonPoolParallelism() :
5398	>	pool.getParallelism();
5399	>	int sp = par << 3; // slack of 8
5400	>	b = batch = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
5401	>	}
5402	>	}
5403	>	return b;
5404	>	}
5405	>
5406	>	/**
5407	>	* Returns exportable snapshot entry.
5408	>	*/
5409	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
5410	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
5411	>	}
5412	>
5413	>	// Unsafe mechanics
5414	>	private static final sun.misc.Unsafe U;
5415	>	private static final long PENDING;
5416	>	static {
5417	>	try {
5418	>	U = sun.misc.Unsafe.getUnsafe();
5419	>	PENDING = U.objectFieldOffset
5420	>	(BulkTask.class.getDeclaredField("pending"));
5421	>	} catch (Exception e) {
5422	>	throw new Error(e);
5423		}
5424		}
1287	–	s.writeObject(null);
1288	–	s.writeObject(null);
5425		}
5426
5427		/**
5428	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
1293	<	* stream (i.e., deserialize it).
1294	<	* @param s the stream
5428	>	* Base class for non-reductive actions
5429		*/
5430	<	private void readObject(java.io.ObjectInputStream s)
5431	<	throws IOException, ClassNotFoundException  {
5432	<	s.defaultReadObject();
5430	>	@SuppressWarnings("serial") static abstract class BulkAction<K,V,R> extends BulkTask<K,V,R> {
5431	>	BulkAction<K,V,?> nextTask;
5432	>	BulkAction(ConcurrentHashMap<K,V> map, BulkTask<K,V,?> parent,
5433	>	int batch, BulkAction<K,V,?> nextTask) {
5434	>	super(map, parent, batch);
5435	>	this.nextTask = nextTask;
5436	>	}
5437
5438	<	// Initialize each segment to be minimally sized, and let grow.
5439	<	for (int i = 0; i < segments.length; ++i) {
5440	<	segments[i].setTable(new HashEntry[1]);
5438	>	/**
5439	>	* Try to complete task and upward parents. Upon hitting
5440	>	* non-completed parent, if a non-FJ task, try to help out the
5441	>	* computation.
5442	>	*/
5443	>	final void tryComplete(BulkAction<K,V,?> subtasks) {
5444	>	BulkTask<K,V,?> a = this, s = a;
5445	>	for (int c;;) {
5446	>	if ((c = a.pending) == 0) {
5447	>	if ((a = (s = a).parent) == null) {
5448	>	s.quietlyComplete();
5449	>	break;
5450	>	}
5451	>	}
5452	>	else if (a.casPending(c, c - 1)) {
5453	>	if (subtasks != null && !inForkJoinPool()) {
5454	>	while ((s = a.parent) != null)
5455	>	a = s;
5456	>	while (!a.isDone()) {
5457	>	BulkAction<K,V,?> next = subtasks.nextTask;
5458	>	if (subtasks.tryUnfork())
5459	>	subtasks.exec();
5460	>	if ((subtasks = next) == null)
5461	>	break;
5462	>	}
5463	>	}
5464	>	break;
5465	>	}
5466	>	}
5467		}
5468
5469	<	// Read the keys and values, and put the mappings in the table
5470	<	for (;;) {
5471	<	K key = (K) s.readObject();
5472	<	V value = (V) s.readObject();
5473	<	if (key == null)
5474	<	break;
5475	<	put(key, value);
5469	>	}
5470	>
5471	>	/*
5472	>	* Task classes. Coded in a regular but ugly format/style to
5473	>	* simplify checks that each variant differs in the right way from
5474	>	* others.
5475	>	*/
5476	>
5477	>	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5478	>	extends BulkAction<K,V,Void> {
5479	>	final Action<K> action;
5480	>	ForEachKeyTask
5481	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5482	>	ForEachKeyTask<K,V> nextTask,
5483	>	Action<K> action) {
5484	>	super(m, p, b, nextTask);
5485	>	this.action = action;
5486	>	}
5487	>	@SuppressWarnings("unchecked") public final boolean exec() {
5488	>	final Action<K> action = this.action;
5489	>	if (action == null)
5490	>	return abortOnNullFunction();
5491	>	ForEachKeyTask<K,V> subtasks = null;
5492	>	try {
5493	>	int b = batch(), c;
5494	>	while (b > 1 && baseIndex != baseLimit) {
5495	>	do {} while (!casPending(c = pending, c+1));
5496	>	(subtasks = new ForEachKeyTask<K,V>
5497	>	(map, this, b >>>= 1, subtasks, action)).fork();
5498	>	}
5499	>	while (advance() != null)
5500	>	action.apply((K)nextKey);
5501	>	} catch (Throwable ex) {
5502	>	return tryCompleteComputation(ex);
5503	>	}
5504	>	tryComplete(subtasks);
5505	>	return false;
5506	>	}
5507	>	}
5508	>
5509	>	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5510	>	extends BulkAction<K,V,Void> {
5511	>	final Action<V> action;
5512	>	ForEachValueTask
5513	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5514	>	ForEachValueTask<K,V> nextTask,
5515	>	Action<V> action) {
5516	>	super(m, p, b, nextTask);
5517	>	this.action = action;
5518	>	}
5519	>	@SuppressWarnings("unchecked") public final boolean exec() {
5520	>	final Action<V> action = this.action;
5521	>	if (action == null)
5522	>	return abortOnNullFunction();
5523	>	ForEachValueTask<K,V> subtasks = null;
5524	>	try {
5525	>	int b = batch(), c;
5526	>	while (b > 1 && baseIndex != baseLimit) {
5527	>	do {} while (!casPending(c = pending, c+1));
5528	>	(subtasks = new ForEachValueTask<K,V>
5529	>	(map, this, b >>>= 1, subtasks, action)).fork();
5530	>	}
5531	>	Object v;
5532	>	while ((v = advance()) != null)
5533	>	action.apply((V)v);
5534	>	} catch (Throwable ex) {
5535	>	return tryCompleteComputation(ex);
5536	>	}
5537	>	tryComplete(subtasks);
5538	>	return false;
5539	>	}
5540	>	}
5541	>
5542	>	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5543	>	extends BulkAction<K,V,Void> {
5544	>	final Action<Entry<K,V>> action;
5545	>	ForEachEntryTask
5546	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5547	>	ForEachEntryTask<K,V> nextTask,
5548	>	Action<Entry<K,V>> action) {
5549	>	super(m, p, b, nextTask);
5550	>	this.action = action;
5551	>	}
5552	>	@SuppressWarnings("unchecked") public final boolean exec() {
5553	>	final Action<Entry<K,V>> action = this.action;
5554	>	if (action == null)
5555	>	return abortOnNullFunction();
5556	>	ForEachEntryTask<K,V> subtasks = null;
5557	>	try {
5558	>	int b = batch(), c;
5559	>	while (b > 1 && baseIndex != baseLimit) {
5560	>	do {} while (!casPending(c = pending, c+1));
5561	>	(subtasks = new ForEachEntryTask<K,V>
5562	>	(map, this, b >>>= 1, subtasks, action)).fork();
5563	>	}
5564	>	Object v;
5565	>	while ((v = advance()) != null)
5566	>	action.apply(entryFor((K)nextKey, (V)v));
5567	>	} catch (Throwable ex) {
5568	>	return tryCompleteComputation(ex);
5569	>	}
5570	>	tryComplete(subtasks);
5571	>	return false;
5572	>	}
5573	>	}
5574	>
5575	>	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5576	>	extends BulkAction<K,V,Void> {
5577	>	final BiAction<K,V> action;
5578	>	ForEachMappingTask
5579	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5580	>	ForEachMappingTask<K,V> nextTask,
5581	>	BiAction<K,V> action) {
5582	>	super(m, p, b, nextTask);
5583	>	this.action = action;
5584	>	}
5585	>	@SuppressWarnings("unchecked") public final boolean exec() {
5586	>	final BiAction<K,V> action = this.action;
5587	>	if (action == null)
5588	>	return abortOnNullFunction();
5589	>	ForEachMappingTask<K,V> subtasks = null;
5590	>	try {
5591	>	int b = batch(), c;
5592	>	while (b > 1 && baseIndex != baseLimit) {
5593	>	do {} while (!casPending(c = pending, c+1));
5594	>	(subtasks = new ForEachMappingTask<K,V>
5595	>	(map, this, b >>>= 1, subtasks, action)).fork();
5596	>	}
5597	>	Object v;
5598	>	while ((v = advance()) != null)
5599	>	action.apply((K)nextKey, (V)v);
5600	>	} catch (Throwable ex) {
5601	>	return tryCompleteComputation(ex);
5602	>	}
5603	>	tryComplete(subtasks);
5604	>	return false;
5605	>	}
5606	>	}
5607	>
5608	>	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5609	>	extends BulkAction<K,V,Void> {
5610	>	final Fun<? super K, ? extends U> transformer;
5611	>	final Action<U> action;
5612	>	ForEachTransformedKeyTask
5613	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5614	>	ForEachTransformedKeyTask<K,V,U> nextTask,
5615	>	Fun<? super K, ? extends U> transformer,
5616	>	Action<U> action) {
5617	>	super(m, p, b, nextTask);
5618	>	this.transformer = transformer;
5619	>	this.action = action;
5620	>
5621	>	}
5622	>	@SuppressWarnings("unchecked") public final boolean exec() {
5623	>	final Fun<? super K, ? extends U> transformer =
5624	>	this.transformer;
5625	>	final Action<U> action = this.action;
5626	>	if (transformer == null || action == null)
5627	>	return abortOnNullFunction();
5628	>	ForEachTransformedKeyTask<K,V,U> subtasks = null;
5629	>	try {
5630	>	int b = batch(), c;
5631	>	while (b > 1 && baseIndex != baseLimit) {
5632	>	do {} while (!casPending(c = pending, c+1));
5633	>	(subtasks = new ForEachTransformedKeyTask<K,V,U>
5634	>	(map, this, b >>>= 1, subtasks, transformer, action)).fork();
5635	>	}
5636	>	U u;
5637	>	while (advance() != null) {
5638	>	if ((u = transformer.apply((K)nextKey)) != null)
5639	>	action.apply(u);
5640	>	}
5641	>	} catch (Throwable ex) {
5642	>	return tryCompleteComputation(ex);
5643	>	}
5644	>	tryComplete(subtasks);
5645	>	return false;
5646	>	}
5647	>	}
5648	>
5649	>	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5650	>	extends BulkAction<K,V,Void> {
5651	>	final Fun<? super V, ? extends U> transformer;
5652	>	final Action<U> action;
5653	>	ForEachTransformedValueTask
5654	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5655	>	ForEachTransformedValueTask<K,V,U> nextTask,
5656	>	Fun<? super V, ? extends U> transformer,
5657	>	Action<U> action) {
5658	>	super(m, p, b, nextTask);
5659	>	this.transformer = transformer;
5660	>	this.action = action;
5661	>
5662	>	}
5663	>	@SuppressWarnings("unchecked") public final boolean exec() {
5664	>	final Fun<? super V, ? extends U> transformer =
5665	>	this.transformer;
5666	>	final Action<U> action = this.action;
5667	>	if (transformer == null || action == null)
5668	>	return abortOnNullFunction();
5669	>	ForEachTransformedValueTask<K,V,U> subtasks = null;
5670	>	try {
5671	>	int b = batch(), c;
5672	>	while (b > 1 && baseIndex != baseLimit) {
5673	>	do {} while (!casPending(c = pending, c+1));
5674	>	(subtasks = new ForEachTransformedValueTask<K,V,U>
5675	>	(map, this, b >>>= 1, subtasks, transformer, action)).fork();
5676	>	}
5677	>	Object v; U u;
5678	>	while ((v = advance()) != null) {
5679	>	if ((u = transformer.apply((V)v)) != null)
5680	>	action.apply(u);
5681	>	}
5682	>	} catch (Throwable ex) {
5683	>	return tryCompleteComputation(ex);
5684	>	}
5685	>	tryComplete(subtasks);
5686	>	return false;
5687	>	}
5688	>	}
5689	>
5690	>	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5691	>	extends BulkAction<K,V,Void> {
5692	>	final Fun<Map.Entry<K,V>, ? extends U> transformer;
5693	>	final Action<U> action;
5694	>	ForEachTransformedEntryTask
5695	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5696	>	ForEachTransformedEntryTask<K,V,U> nextTask,
5697	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5698	>	Action<U> action) {
5699	>	super(m, p, b, nextTask);
5700	>	this.transformer = transformer;
5701	>	this.action = action;
5702	>
5703	>	}
5704	>	@SuppressWarnings("unchecked") public final boolean exec() {
5705	>	final Fun<Map.Entry<K,V>, ? extends U> transformer =
5706	>	this.transformer;
5707	>	final Action<U> action = this.action;
5708	>	if (transformer == null || action == null)
5709	>	return abortOnNullFunction();
5710	>	ForEachTransformedEntryTask<K,V,U> subtasks = null;
5711	>	try {
5712	>	int b = batch(), c;
5713	>	while (b > 1 && baseIndex != baseLimit) {
5714	>	do {} while (!casPending(c = pending, c+1));
5715	>	(subtasks = new ForEachTransformedEntryTask<K,V,U>
5716	>	(map, this, b >>>= 1, subtasks, transformer, action)).fork();
5717	>	}
5718	>	Object v; U u;
5719	>	while ((v = advance()) != null) {
5720	>	if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
5721	>	action.apply(u);
5722	>	}
5723	>	} catch (Throwable ex) {
5724	>	return tryCompleteComputation(ex);
5725	>	}
5726	>	tryComplete(subtasks);
5727	>	return false;
5728	>	}
5729	>	}
5730	>
5731	>	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5732	>	extends BulkAction<K,V,Void> {
5733	>	final BiFun<? super K, ? super V, ? extends U> transformer;
5734	>	final Action<U> action;
5735	>	ForEachTransformedMappingTask
5736	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5737	>	ForEachTransformedMappingTask<K,V,U> nextTask,
5738	>	BiFun<? super K, ? super V, ? extends U> transformer,
5739	>	Action<U> action) {
5740	>	super(m, p, b, nextTask);
5741	>	this.transformer = transformer;
5742	>	this.action = action;
5743	>
5744	>	}
5745	>	@SuppressWarnings("unchecked") public final boolean exec() {
5746	>	final BiFun<? super K, ? super V, ? extends U> transformer =
5747	>	this.transformer;
5748	>	final Action<U> action = this.action;
5749	>	if (transformer == null || action == null)
5750	>	return abortOnNullFunction();
5751	>	ForEachTransformedMappingTask<K,V,U> subtasks = null;
5752	>	try {
5753	>	int b = batch(), c;
5754	>	while (b > 1 && baseIndex != baseLimit) {
5755	>	do {} while (!casPending(c = pending, c+1));
5756	>	(subtasks = new ForEachTransformedMappingTask<K,V,U>
5757	>	(map, this, b >>>= 1, subtasks, transformer, action)).fork();
5758	>	}
5759	>	Object v; U u;
5760	>	while ((v = advance()) != null) {
5761	>	if ((u = transformer.apply((K)nextKey, (V)v)) != null)
5762	>	action.apply(u);
5763	>	}
5764	>	} catch (Throwable ex) {
5765	>	return tryCompleteComputation(ex);
5766	>	}
5767	>	tryComplete(subtasks);
5768	>	return false;
5769	>	}
5770	>	}
5771	>
5772	>	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5773	>	extends BulkAction<K,V,U> {
5774	>	final Fun<? super K, ? extends U> searchFunction;
5775	>	final AtomicReference<U> result;
5776	>	SearchKeysTask
5777	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5778	>	SearchKeysTask<K,V,U> nextTask,
5779	>	Fun<? super K, ? extends U> searchFunction,
5780	>	AtomicReference<U> result) {
5781	>	super(m, p, b, nextTask);
5782	>	this.searchFunction = searchFunction; this.result = result;
5783	>	}
5784	>	@SuppressWarnings("unchecked") public final boolean exec() {
5785	>	AtomicReference<U> result = this.result;
5786	>	final Fun<? super K, ? extends U> searchFunction =
5787	>	this.searchFunction;
5788	>	if (searchFunction == null || result == null)
5789	>	return abortOnNullFunction();
5790	>	SearchKeysTask<K,V,U> subtasks = null;
5791	>	try {
5792	>	int b = batch(), c;
5793	>	while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5794	>	do {} while (!casPending(c = pending, c+1));
5795	>	(subtasks = new SearchKeysTask<K,V,U>
5796	>	(map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5797	>	}
5798	>	U u;
5799	>	while (result.get() == null && advance() != null) {
5800	>	if ((u = searchFunction.apply((K)nextKey)) != null) {
5801	>	if (result.compareAndSet(null, u))
5802	>	tryCompleteComputation(null);
5803	>	break;
5804	>	}
5805	>	}
5806	>	} catch (Throwable ex) {
5807	>	return tryCompleteComputation(ex);
5808	>	}
5809	>	tryComplete(subtasks);
5810	>	return false;
5811	>	}
5812	>	public final U getRawResult() { return result.get(); }
5813	>	}
5814	>
5815	>	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5816	>	extends BulkAction<K,V,U> {
5817	>	final Fun<? super V, ? extends U> searchFunction;
5818	>	final AtomicReference<U> result;
5819	>	SearchValuesTask
5820	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5821	>	SearchValuesTask<K,V,U> nextTask,
5822	>	Fun<? super V, ? extends U> searchFunction,
5823	>	AtomicReference<U> result) {
5824	>	super(m, p, b, nextTask);
5825	>	this.searchFunction = searchFunction; this.result = result;
5826	>	}
5827	>	@SuppressWarnings("unchecked") public final boolean exec() {
5828	>	AtomicReference<U> result = this.result;
5829	>	final Fun<? super V, ? extends U> searchFunction =
5830	>	this.searchFunction;
5831	>	if (searchFunction == null || result == null)
5832	>	return abortOnNullFunction();
5833	>	SearchValuesTask<K,V,U> subtasks = null;
5834	>	try {
5835	>	int b = batch(), c;
5836	>	while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5837	>	do {} while (!casPending(c = pending, c+1));
5838	>	(subtasks = new SearchValuesTask<K,V,U>
5839	>	(map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5840	>	}
5841	>	Object v; U u;
5842	>	while (result.get() == null && (v = advance()) != null) {
5843	>	if ((u = searchFunction.apply((V)v)) != null) {
5844	>	if (result.compareAndSet(null, u))
5845	>	tryCompleteComputation(null);
5846	>	break;
5847	>	}
5848	>	}
5849	>	} catch (Throwable ex) {
5850	>	return tryCompleteComputation(ex);
5851	>	}
5852	>	tryComplete(subtasks);
5853	>	return false;
5854	>	}
5855	>	public final U getRawResult() { return result.get(); }
5856	>	}
5857	>
5858	>	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5859	>	extends BulkAction<K,V,U> {
5860	>	final Fun<Entry<K,V>, ? extends U> searchFunction;
5861	>	final AtomicReference<U> result;
5862	>	SearchEntriesTask
5863	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5864	>	SearchEntriesTask<K,V,U> nextTask,
5865	>	Fun<Entry<K,V>, ? extends U> searchFunction,
5866	>	AtomicReference<U> result) {
5867	>	super(m, p, b, nextTask);
5868	>	this.searchFunction = searchFunction; this.result = result;
5869	>	}
5870	>	@SuppressWarnings("unchecked") public final boolean exec() {
5871	>	AtomicReference<U> result = this.result;
5872	>	final Fun<Entry<K,V>, ? extends U> searchFunction =
5873	>	this.searchFunction;
5874	>	if (searchFunction == null || result == null)
5875	>	return abortOnNullFunction();
5876	>	SearchEntriesTask<K,V,U> subtasks = null;
5877	>	try {
5878	>	int b = batch(), c;
5879	>	while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5880	>	do {} while (!casPending(c = pending, c+1));
5881	>	(subtasks = new SearchEntriesTask<K,V,U>
5882	>	(map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5883	>	}
5884	>	Object v; U u;
5885	>	while (result.get() == null && (v = advance()) != null) {
5886	>	if ((u = searchFunction.apply(entryFor((K)nextKey, (V)v))) != null) {
5887	>	if (result.compareAndSet(null, u))
5888	>	tryCompleteComputation(null);
5889	>	break;
5890	>	}
5891	>	}
5892	>	} catch (Throwable ex) {
5893	>	return tryCompleteComputation(ex);
5894	>	}
5895	>	tryComplete(subtasks);
5896	>	return false;
5897	>	}
5898	>	public final U getRawResult() { return result.get(); }
5899	>	}
5900	>
5901	>	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5902	>	extends BulkAction<K,V,U> {
5903	>	final BiFun<? super K, ? super V, ? extends U> searchFunction;
5904	>	final AtomicReference<U> result;
5905	>	SearchMappingsTask
5906	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5907	>	SearchMappingsTask<K,V,U> nextTask,
5908	>	BiFun<? super K, ? super V, ? extends U> searchFunction,
5909	>	AtomicReference<U> result) {
5910	>	super(m, p, b, nextTask);
5911	>	this.searchFunction = searchFunction; this.result = result;
5912	>	}
5913	>	@SuppressWarnings("unchecked") public final boolean exec() {
5914	>	AtomicReference<U> result = this.result;
5915	>	final BiFun<? super K, ? super V, ? extends U> searchFunction =
5916	>	this.searchFunction;
5917	>	if (searchFunction == null || result == null)
5918	>	return abortOnNullFunction();
5919	>	SearchMappingsTask<K,V,U> subtasks = null;
5920	>	try {
5921	>	int b = batch(), c;
5922	>	while (b > 1 && baseIndex != baseLimit && result.get() == null) {
5923	>	do {} while (!casPending(c = pending, c+1));
5924	>	(subtasks = new SearchMappingsTask<K,V,U>
5925	>	(map, this, b >>>= 1, subtasks, searchFunction, result)).fork();
5926	>	}
5927	>	Object v; U u;
5928	>	while (result.get() == null && (v = advance()) != null) {
5929	>	if ((u = searchFunction.apply((K)nextKey, (V)v)) != null) {
5930	>	if (result.compareAndSet(null, u))
5931	>	tryCompleteComputation(null);
5932	>	break;
5933	>	}
5934	>	}
5935	>	} catch (Throwable ex) {
5936	>	return tryCompleteComputation(ex);
5937	>	}
5938	>	tryComplete(subtasks);
5939	>	return false;
5940	>	}
5941	>	public final U getRawResult() { return result.get(); }
5942	>	}
5943	>
5944	>	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5945	>	extends BulkTask<K,V,K> {
5946	>	final BiFun<? super K, ? super K, ? extends K> reducer;
5947	>	K result;
5948	>	ReduceKeysTask<K,V> rights, nextRight;
5949	>	ReduceKeysTask
5950	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
5951	>	ReduceKeysTask<K,V> nextRight,
5952	>	BiFun<? super K, ? super K, ? extends K> reducer) {
5953	>	super(m, p, b); this.nextRight = nextRight;
5954	>	this.reducer = reducer;
5955	>	}
5956	>	@SuppressWarnings("unchecked") public final boolean exec() {
5957	>	final BiFun<? super K, ? super K, ? extends K> reducer =
5958	>	this.reducer;
5959	>	if (reducer == null)
5960	>	return abortOnNullFunction();
5961	>	try {
5962	>	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
5963	>	do {} while (!casPending(c = pending, c+1));
5964	>	(rights = new ReduceKeysTask<K,V>
5965	>	(map, this, b >>>= 1, rights, reducer)).fork();
5966	>	}
5967	>	K r = null;
5968	>	while (advance() != null) {
5969	>	K u = (K)nextKey;
5970	>	r = (r == null) ? u : reducer.apply(r, u);
5971	>	}
5972	>	result = r;
5973	>	for (ReduceKeysTask<K,V> t = this, s;;) {
5974	>	int c; BulkTask<K,V,?> par; K tr, sr;
5975	>	if ((c = t.pending) == 0) {
5976	>	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
5977	>	if ((sr = s.result) != null)
5978	>	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
5979	>	}
5980	>	if ((par = t.parent) == null ||
5981	>	!(par instanceof ReduceKeysTask)) {
5982	>	t.quietlyComplete();
5983	>	break;
5984	>	}
5985	>	t = (ReduceKeysTask<K,V>)par;
5986	>	}
5987	>	else if (t.casPending(c, c - 1))
5988	>	break;
5989	>	}
5990	>	} catch (Throwable ex) {
5991	>	return tryCompleteComputation(ex);
5992	>	}
5993	>	ReduceKeysTask<K,V> s = rights;
5994	>	if (s != null && !inForkJoinPool()) {
5995	>	do  {
5996	>	if (s.tryUnfork())
5997	>	s.exec();
5998	>	} while ((s = s.nextRight) != null);
5999	>	}
6000	>	return false;
6001	>	}
6002	>	public final K getRawResult() { return result; }
6003	>	}
6004	>
6005	>	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
6006	>	extends BulkTask<K,V,V> {
6007	>	final BiFun<? super V, ? super V, ? extends V> reducer;
6008	>	V result;
6009	>	ReduceValuesTask<K,V> rights, nextRight;
6010	>	ReduceValuesTask
6011	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6012	>	ReduceValuesTask<K,V> nextRight,
6013	>	BiFun<? super V, ? super V, ? extends V> reducer) {
6014	>	super(m, p, b); this.nextRight = nextRight;
6015	>	this.reducer = reducer;
6016	>	}
6017	>	@SuppressWarnings("unchecked") public final boolean exec() {
6018	>	final BiFun<? super V, ? super V, ? extends V> reducer =
6019	>	this.reducer;
6020	>	if (reducer == null)
6021	>	return abortOnNullFunction();
6022	>	try {
6023	>	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6024	>	do {} while (!casPending(c = pending, c+1));
6025	>	(rights = new ReduceValuesTask<K,V>
6026	>	(map, this, b >>>= 1, rights, reducer)).fork();
6027	>	}
6028	>	V r = null;
6029	>	Object v;
6030	>	while ((v = advance()) != null) {
6031	>	V u = (V)v;
6032	>	r = (r == null) ? u : reducer.apply(r, u);
6033	>	}
6034	>	result = r;
6035	>	for (ReduceValuesTask<K,V> t = this, s;;) {
6036	>	int c; BulkTask<K,V,?> par; V tr, sr;
6037	>	if ((c = t.pending) == 0) {
6038	>	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6039	>	if ((sr = s.result) != null)
6040	>	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6041	>	}
6042	>	if ((par = t.parent) == null ||
6043	>	!(par instanceof ReduceValuesTask)) {
6044	>	t.quietlyComplete();
6045	>	break;
6046	>	}
6047	>	t = (ReduceValuesTask<K,V>)par;
6048	>	}
6049	>	else if (t.casPending(c, c - 1))
6050	>	break;
6051	>	}
6052	>	} catch (Throwable ex) {
6053	>	return tryCompleteComputation(ex);
6054	>	}
6055	>	ReduceValuesTask<K,V> s = rights;
6056	>	if (s != null && !inForkJoinPool()) {
6057	>	do  {
6058	>	if (s.tryUnfork())
6059	>	s.exec();
6060	>	} while ((s = s.nextRight) != null);
6061	>	}
6062	>	return false;
6063	>	}
6064	>	public final V getRawResult() { return result; }
6065	>	}
6066	>
6067	>	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
6068	>	extends BulkTask<K,V,Map.Entry<K,V>> {
6069	>	final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
6070	>	Map.Entry<K,V> result;
6071	>	ReduceEntriesTask<K,V> rights, nextRight;
6072	>	ReduceEntriesTask
6073	>	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6074	>	ReduceEntriesTask<K,V> nextRight,
6075	>	BiFun<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
6076	>	super(m, p, b); this.nextRight = nextRight;
6077	>	this.reducer = reducer;
6078	>	}
6079	>	@SuppressWarnings("unchecked") public final boolean exec() {
6080	>	final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer =
6081	>	this.reducer;
6082	>	if (reducer == null)
6083	>	return abortOnNullFunction();
6084	>	try {
6085	>	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6086	>	do {} while (!casPending(c = pending, c+1));
6087	>	(rights = new ReduceEntriesTask<K,V>
6088	>	(map, this, b >>>= 1, rights, reducer)).fork();
6089	>	}
6090	>	Map.Entry<K,V> r = null;
6091	>	Object v;
6092	>	while ((v = advance()) != null) {
6093	>	Map.Entry<K,V> u = entryFor((K)nextKey, (V)v);
6094	>	r = (r == null) ? u : reducer.apply(r, u);
6095	>	}
6096	>	result = r;
6097	>	for (ReduceEntriesTask<K,V> t = this, s;;) {
6098	>	int c; BulkTask<K,V,?> par; Map.Entry<K,V> tr, sr;
6099	>	if ((c = t.pending) == 0) {
6100	>	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6101	>	if ((sr = s.result) != null)
6102	>	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6103	>	}
6104	>	if ((par = t.parent) == null ||
6105	>	!(par instanceof ReduceEntriesTask)) {
6106	>	t.quietlyComplete();
6107	>	break;
6108	>	}
6109	>	t = (ReduceEntriesTask<K,V>)par;
6110	>	}
6111	>	else if (t.casPending(c, c - 1))
6112	>	break;
6113	>	}
6114	>	} catch (Throwable ex) {
6115	>	return tryCompleteComputation(ex);
6116	>	}
6117	>	ReduceEntriesTask<K,V> s = rights;
6118	>	if (s != null && !inForkJoinPool()) {
6119	>	do  {
6120	>	if (s.tryUnfork())
6121	>	s.exec();
6122	>	} while ((s = s.nextRight) != null);
6123	>	}
6124	>	return false;
6125		}
6126	+	public final Map.Entry<K,V> getRawResult() { return result; }
6127	+	}
6128	+
6129	+	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
6130	+	extends BulkTask<K,V,U> {
6131	+	final Fun<? super K, ? extends U> transformer;
6132	+	final BiFun<? super U, ? super U, ? extends U> reducer;
6133	+	U result;
6134	+	MapReduceKeysTask<K,V,U> rights, nextRight;
6135	+	MapReduceKeysTask
6136	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6137	+	MapReduceKeysTask<K,V,U> nextRight,
6138	+	Fun<? super K, ? extends U> transformer,
6139	+	BiFun<? super U, ? super U, ? extends U> reducer) {
6140	+	super(m, p, b); this.nextRight = nextRight;
6141	+	this.transformer = transformer;
6142	+	this.reducer = reducer;
6143	+	}
6144	+	@SuppressWarnings("unchecked") public final boolean exec() {
6145	+	final Fun<? super K, ? extends U> transformer =
6146	+	this.transformer;
6147	+	final BiFun<? super U, ? super U, ? extends U> reducer =
6148	+	this.reducer;
6149	+	if (transformer == null || reducer == null)
6150	+	return abortOnNullFunction();
6151	+	try {
6152	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6153	+	do {} while (!casPending(c = pending, c+1));
6154	+	(rights = new MapReduceKeysTask<K,V,U>
6155	+	(map, this, b >>>= 1, rights, transformer, reducer)).fork();
6156	+	}
6157	+	U r = null, u;
6158	+	while (advance() != null) {
6159	+	if ((u = transformer.apply((K)nextKey)) != null)
6160	+	r = (r == null) ? u : reducer.apply(r, u);
6161	+	}
6162	+	result = r;
6163	+	for (MapReduceKeysTask<K,V,U> t = this, s;;) {
6164	+	int c; BulkTask<K,V,?> par; U tr, sr;
6165	+	if ((c = t.pending) == 0) {
6166	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6167	+	if ((sr = s.result) != null)
6168	+	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6169	+	}
6170	+	if ((par = t.parent) == null ||
6171	+	!(par instanceof MapReduceKeysTask)) {
6172	+	t.quietlyComplete();
6173	+	break;
6174	+	}
6175	+	t = (MapReduceKeysTask<K,V,U>)par;
6176	+	}
6177	+	else if (t.casPending(c, c - 1))
6178	+	break;
6179	+	}
6180	+	} catch (Throwable ex) {
6181	+	return tryCompleteComputation(ex);
6182	+	}
6183	+	MapReduceKeysTask<K,V,U> s = rights;
6184	+	if (s != null && !inForkJoinPool()) {
6185	+	do  {
6186	+	if (s.tryUnfork())
6187	+	s.exec();
6188	+	} while ((s = s.nextRight) != null);
6189	+	}
6190	+	return false;
6191	+	}
6192	+	public final U getRawResult() { return result; }
6193	+	}
6194	+
6195	+	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
6196	+	extends BulkTask<K,V,U> {
6197	+	final Fun<? super V, ? extends U> transformer;
6198	+	final BiFun<? super U, ? super U, ? extends U> reducer;
6199	+	U result;
6200	+	MapReduceValuesTask<K,V,U> rights, nextRight;
6201	+	MapReduceValuesTask
6202	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6203	+	MapReduceValuesTask<K,V,U> nextRight,
6204	+	Fun<? super V, ? extends U> transformer,
6205	+	BiFun<? super U, ? super U, ? extends U> reducer) {
6206	+	super(m, p, b); this.nextRight = nextRight;
6207	+	this.transformer = transformer;
6208	+	this.reducer = reducer;
6209	+	}
6210	+	@SuppressWarnings("unchecked") public final boolean exec() {
6211	+	final Fun<? super V, ? extends U> transformer =
6212	+	this.transformer;
6213	+	final BiFun<? super U, ? super U, ? extends U> reducer =
6214	+	this.reducer;
6215	+	if (transformer == null || reducer == null)
6216	+	return abortOnNullFunction();
6217	+	try {
6218	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6219	+	do {} while (!casPending(c = pending, c+1));
6220	+	(rights = new MapReduceValuesTask<K,V,U>
6221	+	(map, this, b >>>= 1, rights, transformer, reducer)).fork();
6222	+	}
6223	+	U r = null, u;
6224	+	Object v;
6225	+	while ((v = advance()) != null) {
6226	+	if ((u = transformer.apply((V)v)) != null)
6227	+	r = (r == null) ? u : reducer.apply(r, u);
6228	+	}
6229	+	result = r;
6230	+	for (MapReduceValuesTask<K,V,U> t = this, s;;) {
6231	+	int c; BulkTask<K,V,?> par; U tr, sr;
6232	+	if ((c = t.pending) == 0) {
6233	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6234	+	if ((sr = s.result) != null)
6235	+	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6236	+	}
6237	+	if ((par = t.parent) == null ||
6238	+	!(par instanceof MapReduceValuesTask)) {
6239	+	t.quietlyComplete();
6240	+	break;
6241	+	}
6242	+	t = (MapReduceValuesTask<K,V,U>)par;
6243	+	}
6244	+	else if (t.casPending(c, c - 1))
6245	+	break;
6246	+	}
6247	+	} catch (Throwable ex) {
6248	+	return tryCompleteComputation(ex);
6249	+	}
6250	+	MapReduceValuesTask<K,V,U> s = rights;
6251	+	if (s != null && !inForkJoinPool()) {
6252	+	do  {
6253	+	if (s.tryUnfork())
6254	+	s.exec();
6255	+	} while ((s = s.nextRight) != null);
6256	+	}
6257	+	return false;
6258	+	}
6259	+	public final U getRawResult() { return result; }
6260	+	}
6261	+
6262	+	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
6263	+	extends BulkTask<K,V,U> {
6264	+	final Fun<Map.Entry<K,V>, ? extends U> transformer;
6265	+	final BiFun<? super U, ? super U, ? extends U> reducer;
6266	+	U result;
6267	+	MapReduceEntriesTask<K,V,U> rights, nextRight;
6268	+	MapReduceEntriesTask
6269	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6270	+	MapReduceEntriesTask<K,V,U> nextRight,
6271	+	Fun<Map.Entry<K,V>, ? extends U> transformer,
6272	+	BiFun<? super U, ? super U, ? extends U> reducer) {
6273	+	super(m, p, b); this.nextRight = nextRight;
6274	+	this.transformer = transformer;
6275	+	this.reducer = reducer;
6276	+	}
6277	+	@SuppressWarnings("unchecked") public final boolean exec() {
6278	+	final Fun<Map.Entry<K,V>, ? extends U> transformer =
6279	+	this.transformer;
6280	+	final BiFun<? super U, ? super U, ? extends U> reducer =
6281	+	this.reducer;
6282	+	if (transformer == null || reducer == null)
6283	+	return abortOnNullFunction();
6284	+	try {
6285	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6286	+	do {} while (!casPending(c = pending, c+1));
6287	+	(rights = new MapReduceEntriesTask<K,V,U>
6288	+	(map, this, b >>>= 1, rights, transformer, reducer)).fork();
6289	+	}
6290	+	U r = null, u;
6291	+	Object v;
6292	+	while ((v = advance()) != null) {
6293	+	if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
6294	+	r = (r == null) ? u : reducer.apply(r, u);
6295	+	}
6296	+	result = r;
6297	+	for (MapReduceEntriesTask<K,V,U> t = this, s;;) {
6298	+	int c; BulkTask<K,V,?> par; U tr, sr;
6299	+	if ((c = t.pending) == 0) {
6300	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6301	+	if ((sr = s.result) != null)
6302	+	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6303	+	}
6304	+	if ((par = t.parent) == null ||
6305	+	!(par instanceof MapReduceEntriesTask)) {
6306	+	t.quietlyComplete();
6307	+	break;
6308	+	}
6309	+	t = (MapReduceEntriesTask<K,V,U>)par;
6310	+	}
6311	+	else if (t.casPending(c, c - 1))
6312	+	break;
6313	+	}
6314	+	} catch (Throwable ex) {
6315	+	return tryCompleteComputation(ex);
6316	+	}
6317	+	MapReduceEntriesTask<K,V,U> s = rights;
6318	+	if (s != null && !inForkJoinPool()) {
6319	+	do  {
6320	+	if (s.tryUnfork())
6321	+	s.exec();
6322	+	} while ((s = s.nextRight) != null);
6323	+	}
6324	+	return false;
6325	+	}
6326	+	public final U getRawResult() { return result; }
6327	+	}
6328	+
6329	+	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6330	+	extends BulkTask<K,V,U> {
6331	+	final BiFun<? super K, ? super V, ? extends U> transformer;
6332	+	final BiFun<? super U, ? super U, ? extends U> reducer;
6333	+	U result;
6334	+	MapReduceMappingsTask<K,V,U> rights, nextRight;
6335	+	MapReduceMappingsTask
6336	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6337	+	MapReduceMappingsTask<K,V,U> nextRight,
6338	+	BiFun<? super K, ? super V, ? extends U> transformer,
6339	+	BiFun<? super U, ? super U, ? extends U> reducer) {
6340	+	super(m, p, b); this.nextRight = nextRight;
6341	+	this.transformer = transformer;
6342	+	this.reducer = reducer;
6343	+	}
6344	+	@SuppressWarnings("unchecked") public final boolean exec() {
6345	+	final BiFun<? super K, ? super V, ? extends U> transformer =
6346	+	this.transformer;
6347	+	final BiFun<? super U, ? super U, ? extends U> reducer =
6348	+	this.reducer;
6349	+	if (transformer == null || reducer == null)
6350	+	return abortOnNullFunction();
6351	+	try {
6352	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6353	+	do {} while (!casPending(c = pending, c+1));
6354	+	(rights = new MapReduceMappingsTask<K,V,U>
6355	+	(map, this, b >>>= 1, rights, transformer, reducer)).fork();
6356	+	}
6357	+	U r = null, u;
6358	+	Object v;
6359	+	while ((v = advance()) != null) {
6360	+	if ((u = transformer.apply((K)nextKey, (V)v)) != null)
6361	+	r = (r == null) ? u : reducer.apply(r, u);
6362	+	}
6363	+	result = r;
6364	+	for (MapReduceMappingsTask<K,V,U> t = this, s;;) {
6365	+	int c; BulkTask<K,V,?> par; U tr, sr;
6366	+	if ((c = t.pending) == 0) {
6367	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6368	+	if ((sr = s.result) != null)
6369	+	t.result = ((tr = t.result) == null) ? sr : reducer.apply(tr, sr);
6370	+	}
6371	+	if ((par = t.parent) == null ||
6372	+	!(par instanceof MapReduceMappingsTask)) {
6373	+	t.quietlyComplete();
6374	+	break;
6375	+	}
6376	+	t = (MapReduceMappingsTask<K,V,U>)par;
6377	+	}
6378	+	else if (t.casPending(c, c - 1))
6379	+	break;
6380	+	}
6381	+	} catch (Throwable ex) {
6382	+	return tryCompleteComputation(ex);
6383	+	}
6384	+	MapReduceMappingsTask<K,V,U> s = rights;
6385	+	if (s != null && !inForkJoinPool()) {
6386	+	do  {
6387	+	if (s.tryUnfork())
6388	+	s.exec();
6389	+	} while ((s = s.nextRight) != null);
6390	+	}
6391	+	return false;
6392	+	}
6393	+	public final U getRawResult() { return result; }
6394	+	}
6395	+
6396	+	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6397	+	extends BulkTask<K,V,Double> {
6398	+	final ObjectToDouble<? super K> transformer;
6399	+	final DoubleByDoubleToDouble reducer;
6400	+	final double basis;
6401	+	double result;
6402	+	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6403	+	MapReduceKeysToDoubleTask
6404	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6405	+	MapReduceKeysToDoubleTask<K,V> nextRight,
6406	+	ObjectToDouble<? super K> transformer,
6407	+	double basis,
6408	+	DoubleByDoubleToDouble reducer) {
6409	+	super(m, p, b); this.nextRight = nextRight;
6410	+	this.transformer = transformer;
6411	+	this.basis = basis; this.reducer = reducer;
6412	+	}
6413	+	@SuppressWarnings("unchecked") public final boolean exec() {
6414	+	final ObjectToDouble<? super K> transformer =
6415	+	this.transformer;
6416	+	final DoubleByDoubleToDouble reducer = this.reducer;
6417	+	if (transformer == null || reducer == null)
6418	+	return abortOnNullFunction();
6419	+	try {
6420	+	final double id = this.basis;
6421	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6422	+	do {} while (!casPending(c = pending, c+1));
6423	+	(rights = new MapReduceKeysToDoubleTask<K,V>
6424	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6425	+	}
6426	+	double r = id;
6427	+	while (advance() != null)
6428	+	r = reducer.apply(r, transformer.apply((K)nextKey));
6429	+	result = r;
6430	+	for (MapReduceKeysToDoubleTask<K,V> t = this, s;;) {
6431	+	int c; BulkTask<K,V,?> par;
6432	+	if ((c = t.pending) == 0) {
6433	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6434	+	t.result = reducer.apply(t.result, s.result);
6435	+	}
6436	+	if ((par = t.parent) == null ||
6437	+	!(par instanceof MapReduceKeysToDoubleTask)) {
6438	+	t.quietlyComplete();
6439	+	break;
6440	+	}
6441	+	t = (MapReduceKeysToDoubleTask<K,V>)par;
6442	+	}
6443	+	else if (t.casPending(c, c - 1))
6444	+	break;
6445	+	}
6446	+	} catch (Throwable ex) {
6447	+	return tryCompleteComputation(ex);
6448	+	}
6449	+	MapReduceKeysToDoubleTask<K,V> s = rights;
6450	+	if (s != null && !inForkJoinPool()) {
6451	+	do  {
6452	+	if (s.tryUnfork())
6453	+	s.exec();
6454	+	} while ((s = s.nextRight) != null);
6455	+	}
6456	+	return false;
6457	+	}
6458	+	public final Double getRawResult() { return result; }
6459	+	}
6460	+
6461	+	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6462	+	extends BulkTask<K,V,Double> {
6463	+	final ObjectToDouble<? super V> transformer;
6464	+	final DoubleByDoubleToDouble reducer;
6465	+	final double basis;
6466	+	double result;
6467	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6468	+	MapReduceValuesToDoubleTask
6469	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6470	+	MapReduceValuesToDoubleTask<K,V> nextRight,
6471	+	ObjectToDouble<? super V> transformer,
6472	+	double basis,
6473	+	DoubleByDoubleToDouble reducer) {
6474	+	super(m, p, b); this.nextRight = nextRight;
6475	+	this.transformer = transformer;
6476	+	this.basis = basis; this.reducer = reducer;
6477	+	}
6478	+	@SuppressWarnings("unchecked") public final boolean exec() {
6479	+	final ObjectToDouble<? super V> transformer =
6480	+	this.transformer;
6481	+	final DoubleByDoubleToDouble reducer = this.reducer;
6482	+	if (transformer == null || reducer == null)
6483	+	return abortOnNullFunction();
6484	+	try {
6485	+	final double id = this.basis;
6486	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6487	+	do {} while (!casPending(c = pending, c+1));
6488	+	(rights = new MapReduceValuesToDoubleTask<K,V>
6489	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6490	+	}
6491	+	double r = id;
6492	+	Object v;
6493	+	while ((v = advance()) != null)
6494	+	r = reducer.apply(r, transformer.apply((V)v));
6495	+	result = r;
6496	+	for (MapReduceValuesToDoubleTask<K,V> t = this, s;;) {
6497	+	int c; BulkTask<K,V,?> par;
6498	+	if ((c = t.pending) == 0) {
6499	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6500	+	t.result = reducer.apply(t.result, s.result);
6501	+	}
6502	+	if ((par = t.parent) == null ||
6503	+	!(par instanceof MapReduceValuesToDoubleTask)) {
6504	+	t.quietlyComplete();
6505	+	break;
6506	+	}
6507	+	t = (MapReduceValuesToDoubleTask<K,V>)par;
6508	+	}
6509	+	else if (t.casPending(c, c - 1))
6510	+	break;
6511	+	}
6512	+	} catch (Throwable ex) {
6513	+	return tryCompleteComputation(ex);
6514	+	}
6515	+	MapReduceValuesToDoubleTask<K,V> s = rights;
6516	+	if (s != null && !inForkJoinPool()) {
6517	+	do  {
6518	+	if (s.tryUnfork())
6519	+	s.exec();
6520	+	} while ((s = s.nextRight) != null);
6521	+	}
6522	+	return false;
6523	+	}
6524	+	public final Double getRawResult() { return result; }
6525	+	}
6526	+
6527	+	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6528	+	extends BulkTask<K,V,Double> {
6529	+	final ObjectToDouble<Map.Entry<K,V>> transformer;
6530	+	final DoubleByDoubleToDouble reducer;
6531	+	final double basis;
6532	+	double result;
6533	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6534	+	MapReduceEntriesToDoubleTask
6535	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6536	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
6537	+	ObjectToDouble<Map.Entry<K,V>> transformer,
6538	+	double basis,
6539	+	DoubleByDoubleToDouble reducer) {
6540	+	super(m, p, b); this.nextRight = nextRight;
6541	+	this.transformer = transformer;
6542	+	this.basis = basis; this.reducer = reducer;
6543	+	}
6544	+	@SuppressWarnings("unchecked") public final boolean exec() {
6545	+	final ObjectToDouble<Map.Entry<K,V>> transformer =
6546	+	this.transformer;
6547	+	final DoubleByDoubleToDouble reducer = this.reducer;
6548	+	if (transformer == null || reducer == null)
6549	+	return abortOnNullFunction();
6550	+	try {
6551	+	final double id = this.basis;
6552	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6553	+	do {} while (!casPending(c = pending, c+1));
6554	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
6555	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6556	+	}
6557	+	double r = id;
6558	+	Object v;
6559	+	while ((v = advance()) != null)
6560	+	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6561	+	result = r;
6562	+	for (MapReduceEntriesToDoubleTask<K,V> t = this, s;;) {
6563	+	int c; BulkTask<K,V,?> par;
6564	+	if ((c = t.pending) == 0) {
6565	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6566	+	t.result = reducer.apply(t.result, s.result);
6567	+	}
6568	+	if ((par = t.parent) == null ||
6569	+	!(par instanceof MapReduceEntriesToDoubleTask)) {
6570	+	t.quietlyComplete();
6571	+	break;
6572	+	}
6573	+	t = (MapReduceEntriesToDoubleTask<K,V>)par;
6574	+	}
6575	+	else if (t.casPending(c, c - 1))
6576	+	break;
6577	+	}
6578	+	} catch (Throwable ex) {
6579	+	return tryCompleteComputation(ex);
6580	+	}
6581	+	MapReduceEntriesToDoubleTask<K,V> s = rights;
6582	+	if (s != null && !inForkJoinPool()) {
6583	+	do  {
6584	+	if (s.tryUnfork())
6585	+	s.exec();
6586	+	} while ((s = s.nextRight) != null);
6587	+	}
6588	+	return false;
6589	+	}
6590	+	public final Double getRawResult() { return result; }
6591	+	}
6592	+
6593	+	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6594	+	extends BulkTask<K,V,Double> {
6595	+	final ObjectByObjectToDouble<? super K, ? super V> transformer;
6596	+	final DoubleByDoubleToDouble reducer;
6597	+	final double basis;
6598	+	double result;
6599	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6600	+	MapReduceMappingsToDoubleTask
6601	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6602	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
6603	+	ObjectByObjectToDouble<? super K, ? super V> transformer,
6604	+	double basis,
6605	+	DoubleByDoubleToDouble reducer) {
6606	+	super(m, p, b); this.nextRight = nextRight;
6607	+	this.transformer = transformer;
6608	+	this.basis = basis; this.reducer = reducer;
6609	+	}
6610	+	@SuppressWarnings("unchecked") public final boolean exec() {
6611	+	final ObjectByObjectToDouble<? super K, ? super V> transformer =
6612	+	this.transformer;
6613	+	final DoubleByDoubleToDouble reducer = this.reducer;
6614	+	if (transformer == null || reducer == null)
6615	+	return abortOnNullFunction();
6616	+	try {
6617	+	final double id = this.basis;
6618	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6619	+	do {} while (!casPending(c = pending, c+1));
6620	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
6621	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6622	+	}
6623	+	double r = id;
6624	+	Object v;
6625	+	while ((v = advance()) != null)
6626	+	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6627	+	result = r;
6628	+	for (MapReduceMappingsToDoubleTask<K,V> t = this, s;;) {
6629	+	int c; BulkTask<K,V,?> par;
6630	+	if ((c = t.pending) == 0) {
6631	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6632	+	t.result = reducer.apply(t.result, s.result);
6633	+	}
6634	+	if ((par = t.parent) == null ||
6635	+	!(par instanceof MapReduceMappingsToDoubleTask)) {
6636	+	t.quietlyComplete();
6637	+	break;
6638	+	}
6639	+	t = (MapReduceMappingsToDoubleTask<K,V>)par;
6640	+	}
6641	+	else if (t.casPending(c, c - 1))
6642	+	break;
6643	+	}
6644	+	} catch (Throwable ex) {
6645	+	return tryCompleteComputation(ex);
6646	+	}
6647	+	MapReduceMappingsToDoubleTask<K,V> s = rights;
6648	+	if (s != null && !inForkJoinPool()) {
6649	+	do  {
6650	+	if (s.tryUnfork())
6651	+	s.exec();
6652	+	} while ((s = s.nextRight) != null);
6653	+	}
6654	+	return false;
6655	+	}
6656	+	public final Double getRawResult() { return result; }
6657	+	}
6658	+
6659	+	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6660	+	extends BulkTask<K,V,Long> {
6661	+	final ObjectToLong<? super K> transformer;
6662	+	final LongByLongToLong reducer;
6663	+	final long basis;
6664	+	long result;
6665	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
6666	+	MapReduceKeysToLongTask
6667	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6668	+	MapReduceKeysToLongTask<K,V> nextRight,
6669	+	ObjectToLong<? super K> transformer,
6670	+	long basis,
6671	+	LongByLongToLong reducer) {
6672	+	super(m, p, b); this.nextRight = nextRight;
6673	+	this.transformer = transformer;
6674	+	this.basis = basis; this.reducer = reducer;
6675	+	}
6676	+	@SuppressWarnings("unchecked") public final boolean exec() {
6677	+	final ObjectToLong<? super K> transformer =
6678	+	this.transformer;
6679	+	final LongByLongToLong reducer = this.reducer;
6680	+	if (transformer == null || reducer == null)
6681	+	return abortOnNullFunction();
6682	+	try {
6683	+	final long id = this.basis;
6684	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6685	+	do {} while (!casPending(c = pending, c+1));
6686	+	(rights = new MapReduceKeysToLongTask<K,V>
6687	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6688	+	}
6689	+	long r = id;
6690	+	while (advance() != null)
6691	+	r = reducer.apply(r, transformer.apply((K)nextKey));
6692	+	result = r;
6693	+	for (MapReduceKeysToLongTask<K,V> t = this, s;;) {
6694	+	int c; BulkTask<K,V,?> par;
6695	+	if ((c = t.pending) == 0) {
6696	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6697	+	t.result = reducer.apply(t.result, s.result);
6698	+	}
6699	+	if ((par = t.parent) == null ||
6700	+	!(par instanceof MapReduceKeysToLongTask)) {
6701	+	t.quietlyComplete();
6702	+	break;
6703	+	}
6704	+	t = (MapReduceKeysToLongTask<K,V>)par;
6705	+	}
6706	+	else if (t.casPending(c, c - 1))
6707	+	break;
6708	+	}
6709	+	} catch (Throwable ex) {
6710	+	return tryCompleteComputation(ex);
6711	+	}
6712	+	MapReduceKeysToLongTask<K,V> s = rights;
6713	+	if (s != null && !inForkJoinPool()) {
6714	+	do  {
6715	+	if (s.tryUnfork())
6716	+	s.exec();
6717	+	} while ((s = s.nextRight) != null);
6718	+	}
6719	+	return false;
6720	+	}
6721	+	public final Long getRawResult() { return result; }
6722	+	}
6723	+
6724	+	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6725	+	extends BulkTask<K,V,Long> {
6726	+	final ObjectToLong<? super V> transformer;
6727	+	final LongByLongToLong reducer;
6728	+	final long basis;
6729	+	long result;
6730	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
6731	+	MapReduceValuesToLongTask
6732	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6733	+	MapReduceValuesToLongTask<K,V> nextRight,
6734	+	ObjectToLong<? super V> transformer,
6735	+	long basis,
6736	+	LongByLongToLong reducer) {
6737	+	super(m, p, b); this.nextRight = nextRight;
6738	+	this.transformer = transformer;
6739	+	this.basis = basis; this.reducer = reducer;
6740	+	}
6741	+	@SuppressWarnings("unchecked") public final boolean exec() {
6742	+	final ObjectToLong<? super V> transformer =
6743	+	this.transformer;
6744	+	final LongByLongToLong reducer = this.reducer;
6745	+	if (transformer == null || reducer == null)
6746	+	return abortOnNullFunction();
6747	+	try {
6748	+	final long id = this.basis;
6749	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6750	+	do {} while (!casPending(c = pending, c+1));
6751	+	(rights = new MapReduceValuesToLongTask<K,V>
6752	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6753	+	}
6754	+	long r = id;
6755	+	Object v;
6756	+	while ((v = advance()) != null)
6757	+	r = reducer.apply(r, transformer.apply((V)v));
6758	+	result = r;
6759	+	for (MapReduceValuesToLongTask<K,V> t = this, s;;) {
6760	+	int c; BulkTask<K,V,?> par;
6761	+	if ((c = t.pending) == 0) {
6762	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6763	+	t.result = reducer.apply(t.result, s.result);
6764	+	}
6765	+	if ((par = t.parent) == null ||
6766	+	!(par instanceof MapReduceValuesToLongTask)) {
6767	+	t.quietlyComplete();
6768	+	break;
6769	+	}
6770	+	t = (MapReduceValuesToLongTask<K,V>)par;
6771	+	}
6772	+	else if (t.casPending(c, c - 1))
6773	+	break;
6774	+	}
6775	+	} catch (Throwable ex) {
6776	+	return tryCompleteComputation(ex);
6777	+	}
6778	+	MapReduceValuesToLongTask<K,V> s = rights;
6779	+	if (s != null && !inForkJoinPool()) {
6780	+	do  {
6781	+	if (s.tryUnfork())
6782	+	s.exec();
6783	+	} while ((s = s.nextRight) != null);
6784	+	}
6785	+	return false;
6786	+	}
6787	+	public final Long getRawResult() { return result; }
6788	+	}
6789	+
6790	+	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6791	+	extends BulkTask<K,V,Long> {
6792	+	final ObjectToLong<Map.Entry<K,V>> transformer;
6793	+	final LongByLongToLong reducer;
6794	+	final long basis;
6795	+	long result;
6796	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6797	+	MapReduceEntriesToLongTask
6798	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6799	+	MapReduceEntriesToLongTask<K,V> nextRight,
6800	+	ObjectToLong<Map.Entry<K,V>> transformer,
6801	+	long basis,
6802	+	LongByLongToLong reducer) {
6803	+	super(m, p, b); this.nextRight = nextRight;
6804	+	this.transformer = transformer;
6805	+	this.basis = basis; this.reducer = reducer;
6806	+	}
6807	+	@SuppressWarnings("unchecked") public final boolean exec() {
6808	+	final ObjectToLong<Map.Entry<K,V>> transformer =
6809	+	this.transformer;
6810	+	final LongByLongToLong reducer = this.reducer;
6811	+	if (transformer == null || reducer == null)
6812	+	return abortOnNullFunction();
6813	+	try {
6814	+	final long id = this.basis;
6815	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6816	+	do {} while (!casPending(c = pending, c+1));
6817	+	(rights = new MapReduceEntriesToLongTask<K,V>
6818	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6819	+	}
6820	+	long r = id;
6821	+	Object v;
6822	+	while ((v = advance()) != null)
6823	+	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6824	+	result = r;
6825	+	for (MapReduceEntriesToLongTask<K,V> t = this, s;;) {
6826	+	int c; BulkTask<K,V,?> par;
6827	+	if ((c = t.pending) == 0) {
6828	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6829	+	t.result = reducer.apply(t.result, s.result);
6830	+	}
6831	+	if ((par = t.parent) == null ||
6832	+	!(par instanceof MapReduceEntriesToLongTask)) {
6833	+	t.quietlyComplete();
6834	+	break;
6835	+	}
6836	+	t = (MapReduceEntriesToLongTask<K,V>)par;
6837	+	}
6838	+	else if (t.casPending(c, c - 1))
6839	+	break;
6840	+	}
6841	+	} catch (Throwable ex) {
6842	+	return tryCompleteComputation(ex);
6843	+	}
6844	+	MapReduceEntriesToLongTask<K,V> s = rights;
6845	+	if (s != null && !inForkJoinPool()) {
6846	+	do  {
6847	+	if (s.tryUnfork())
6848	+	s.exec();
6849	+	} while ((s = s.nextRight) != null);
6850	+	}
6851	+	return false;
6852	+	}
6853	+	public final Long getRawResult() { return result; }
6854	+	}
6855	+
6856	+	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6857	+	extends BulkTask<K,V,Long> {
6858	+	final ObjectByObjectToLong<? super K, ? super V> transformer;
6859	+	final LongByLongToLong reducer;
6860	+	final long basis;
6861	+	long result;
6862	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6863	+	MapReduceMappingsToLongTask
6864	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6865	+	MapReduceMappingsToLongTask<K,V> nextRight,
6866	+	ObjectByObjectToLong<? super K, ? super V> transformer,
6867	+	long basis,
6868	+	LongByLongToLong reducer) {
6869	+	super(m, p, b); this.nextRight = nextRight;
6870	+	this.transformer = transformer;
6871	+	this.basis = basis; this.reducer = reducer;
6872	+	}
6873	+	@SuppressWarnings("unchecked") public final boolean exec() {
6874	+	final ObjectByObjectToLong<? super K, ? super V> transformer =
6875	+	this.transformer;
6876	+	final LongByLongToLong reducer = this.reducer;
6877	+	if (transformer == null || reducer == null)
6878	+	return abortOnNullFunction();
6879	+	try {
6880	+	final long id = this.basis;
6881	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6882	+	do {} while (!casPending(c = pending, c+1));
6883	+	(rights = new MapReduceMappingsToLongTask<K,V>
6884	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6885	+	}
6886	+	long r = id;
6887	+	Object v;
6888	+	while ((v = advance()) != null)
6889	+	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6890	+	result = r;
6891	+	for (MapReduceMappingsToLongTask<K,V> t = this, s;;) {
6892	+	int c; BulkTask<K,V,?> par;
6893	+	if ((c = t.pending) == 0) {
6894	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6895	+	t.result = reducer.apply(t.result, s.result);
6896	+	}
6897	+	if ((par = t.parent) == null ||
6898	+	!(par instanceof MapReduceMappingsToLongTask)) {
6899	+	t.quietlyComplete();
6900	+	break;
6901	+	}
6902	+	t = (MapReduceMappingsToLongTask<K,V>)par;
6903	+	}
6904	+	else if (t.casPending(c, c - 1))
6905	+	break;
6906	+	}
6907	+	} catch (Throwable ex) {
6908	+	return tryCompleteComputation(ex);
6909	+	}
6910	+	MapReduceMappingsToLongTask<K,V> s = rights;
6911	+	if (s != null && !inForkJoinPool()) {
6912	+	do  {
6913	+	if (s.tryUnfork())
6914	+	s.exec();
6915	+	} while ((s = s.nextRight) != null);
6916	+	}
6917	+	return false;
6918	+	}
6919	+	public final Long getRawResult() { return result; }
6920	+	}
6921	+
6922	+	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6923	+	extends BulkTask<K,V,Integer> {
6924	+	final ObjectToInt<? super K> transformer;
6925	+	final IntByIntToInt reducer;
6926	+	final int basis;
6927	+	int result;
6928	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6929	+	MapReduceKeysToIntTask
6930	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6931	+	MapReduceKeysToIntTask<K,V> nextRight,
6932	+	ObjectToInt<? super K> transformer,
6933	+	int basis,
6934	+	IntByIntToInt reducer) {
6935	+	super(m, p, b); this.nextRight = nextRight;
6936	+	this.transformer = transformer;
6937	+	this.basis = basis; this.reducer = reducer;
6938	+	}
6939	+	@SuppressWarnings("unchecked") public final boolean exec() {
6940	+	final ObjectToInt<? super K> transformer =
6941	+	this.transformer;
6942	+	final IntByIntToInt reducer = this.reducer;
6943	+	if (transformer == null || reducer == null)
6944	+	return abortOnNullFunction();
6945	+	try {
6946	+	final int id = this.basis;
6947	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
6948	+	do {} while (!casPending(c = pending, c+1));
6949	+	(rights = new MapReduceKeysToIntTask<K,V>
6950	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
6951	+	}
6952	+	int r = id;
6953	+	while (advance() != null)
6954	+	r = reducer.apply(r, transformer.apply((K)nextKey));
6955	+	result = r;
6956	+	for (MapReduceKeysToIntTask<K,V> t = this, s;;) {
6957	+	int c; BulkTask<K,V,?> par;
6958	+	if ((c = t.pending) == 0) {
6959	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
6960	+	t.result = reducer.apply(t.result, s.result);
6961	+	}
6962	+	if ((par = t.parent) == null ||
6963	+	!(par instanceof MapReduceKeysToIntTask)) {
6964	+	t.quietlyComplete();
6965	+	break;
6966	+	}
6967	+	t = (MapReduceKeysToIntTask<K,V>)par;
6968	+	}
6969	+	else if (t.casPending(c, c - 1))
6970	+	break;
6971	+	}
6972	+	} catch (Throwable ex) {
6973	+	return tryCompleteComputation(ex);
6974	+	}
6975	+	MapReduceKeysToIntTask<K,V> s = rights;
6976	+	if (s != null && !inForkJoinPool()) {
6977	+	do  {
6978	+	if (s.tryUnfork())
6979	+	s.exec();
6980	+	} while ((s = s.nextRight) != null);
6981	+	}
6982	+	return false;
6983	+	}
6984	+	public final Integer getRawResult() { return result; }
6985	+	}
6986	+
6987	+	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6988	+	extends BulkTask<K,V,Integer> {
6989	+	final ObjectToInt<? super V> transformer;
6990	+	final IntByIntToInt reducer;
6991	+	final int basis;
6992	+	int result;
6993	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6994	+	MapReduceValuesToIntTask
6995	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
6996	+	MapReduceValuesToIntTask<K,V> nextRight,
6997	+	ObjectToInt<? super V> transformer,
6998	+	int basis,
6999	+	IntByIntToInt reducer) {
7000	+	super(m, p, b); this.nextRight = nextRight;
7001	+	this.transformer = transformer;
7002	+	this.basis = basis; this.reducer = reducer;
7003	+	}
7004	+	@SuppressWarnings("unchecked") public final boolean exec() {
7005	+	final ObjectToInt<? super V> transformer =
7006	+	this.transformer;
7007	+	final IntByIntToInt reducer = this.reducer;
7008	+	if (transformer == null || reducer == null)
7009	+	return abortOnNullFunction();
7010	+	try {
7011	+	final int id = this.basis;
7012	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
7013	+	do {} while (!casPending(c = pending, c+1));
7014	+	(rights = new MapReduceValuesToIntTask<K,V>
7015	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
7016	+	}
7017	+	int r = id;
7018	+	Object v;
7019	+	while ((v = advance()) != null)
7020	+	r = reducer.apply(r, transformer.apply((V)v));
7021	+	result = r;
7022	+	for (MapReduceValuesToIntTask<K,V> t = this, s;;) {
7023	+	int c; BulkTask<K,V,?> par;
7024	+	if ((c = t.pending) == 0) {
7025	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
7026	+	t.result = reducer.apply(t.result, s.result);
7027	+	}
7028	+	if ((par = t.parent) == null ||
7029	+	!(par instanceof MapReduceValuesToIntTask)) {
7030	+	t.quietlyComplete();
7031	+	break;
7032	+	}
7033	+	t = (MapReduceValuesToIntTask<K,V>)par;
7034	+	}
7035	+	else if (t.casPending(c, c - 1))
7036	+	break;
7037	+	}
7038	+	} catch (Throwable ex) {
7039	+	return tryCompleteComputation(ex);
7040	+	}
7041	+	MapReduceValuesToIntTask<K,V> s = rights;
7042	+	if (s != null && !inForkJoinPool()) {
7043	+	do  {
7044	+	if (s.tryUnfork())
7045	+	s.exec();
7046	+	} while ((s = s.nextRight) != null);
7047	+	}
7048	+	return false;
7049	+	}
7050	+	public final Integer getRawResult() { return result; }
7051	+	}
7052	+
7053	+	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
7054	+	extends BulkTask<K,V,Integer> {
7055	+	final ObjectToInt<Map.Entry<K,V>> transformer;
7056	+	final IntByIntToInt reducer;
7057	+	final int basis;
7058	+	int result;
7059	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
7060	+	MapReduceEntriesToIntTask
7061	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
7062	+	MapReduceEntriesToIntTask<K,V> nextRight,
7063	+	ObjectToInt<Map.Entry<K,V>> transformer,
7064	+	int basis,
7065	+	IntByIntToInt reducer) {
7066	+	super(m, p, b); this.nextRight = nextRight;
7067	+	this.transformer = transformer;
7068	+	this.basis = basis; this.reducer = reducer;
7069	+	}
7070	+	@SuppressWarnings("unchecked") public final boolean exec() {
7071	+	final ObjectToInt<Map.Entry<K,V>> transformer =
7072	+	this.transformer;
7073	+	final IntByIntToInt reducer = this.reducer;
7074	+	if (transformer == null || reducer == null)
7075	+	return abortOnNullFunction();
7076	+	try {
7077	+	final int id = this.basis;
7078	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
7079	+	do {} while (!casPending(c = pending, c+1));
7080	+	(rights = new MapReduceEntriesToIntTask<K,V>
7081	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
7082	+	}
7083	+	int r = id;
7084	+	Object v;
7085	+	while ((v = advance()) != null)
7086	+	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
7087	+	result = r;
7088	+	for (MapReduceEntriesToIntTask<K,V> t = this, s;;) {
7089	+	int c; BulkTask<K,V,?> par;
7090	+	if ((c = t.pending) == 0) {
7091	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
7092	+	t.result = reducer.apply(t.result, s.result);
7093	+	}
7094	+	if ((par = t.parent) == null ||
7095	+	!(par instanceof MapReduceEntriesToIntTask)) {
7096	+	t.quietlyComplete();
7097	+	break;
7098	+	}
7099	+	t = (MapReduceEntriesToIntTask<K,V>)par;
7100	+	}
7101	+	else if (t.casPending(c, c - 1))
7102	+	break;
7103	+	}
7104	+	} catch (Throwable ex) {
7105	+	return tryCompleteComputation(ex);
7106	+	}
7107	+	MapReduceEntriesToIntTask<K,V> s = rights;
7108	+	if (s != null && !inForkJoinPool()) {
7109	+	do  {
7110	+	if (s.tryUnfork())
7111	+	s.exec();
7112	+	} while ((s = s.nextRight) != null);
7113	+	}
7114	+	return false;
7115	+	}
7116	+	public final Integer getRawResult() { return result; }
7117	+	}
7118	+
7119	+	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
7120	+	extends BulkTask<K,V,Integer> {
7121	+	final ObjectByObjectToInt<? super K, ? super V> transformer;
7122	+	final IntByIntToInt reducer;
7123	+	final int basis;
7124	+	int result;
7125	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
7126	+	MapReduceMappingsToIntTask
7127	+	(ConcurrentHashMap<K,V> m, BulkTask<K,V,?> p, int b,
7128	+	MapReduceMappingsToIntTask<K,V> rights,
7129	+	ObjectByObjectToInt<? super K, ? super V> transformer,
7130	+	int basis,
7131	+	IntByIntToInt reducer) {
7132	+	super(m, p, b); this.nextRight = nextRight;
7133	+	this.transformer = transformer;
7134	+	this.basis = basis; this.reducer = reducer;
7135	+	}
7136	+	@SuppressWarnings("unchecked") public final boolean exec() {
7137	+	final ObjectByObjectToInt<? super K, ? super V> transformer =
7138	+	this.transformer;
7139	+	final IntByIntToInt reducer = this.reducer;
7140	+	if (transformer == null || reducer == null)
7141	+	return abortOnNullFunction();
7142	+	try {
7143	+	final int id = this.basis;
7144	+	for (int c, b = batch(); b > 1 && baseIndex != baseLimit;) {
7145	+	do {} while (!casPending(c = pending, c+1));
7146	+	(rights = new MapReduceMappingsToIntTask<K,V>
7147	+	(map, this, b >>>= 1, rights, transformer, id, reducer)).fork();
7148	+	}
7149	+	int r = id;
7150	+	Object v;
7151	+	while ((v = advance()) != null)
7152	+	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
7153	+	result = r;
7154	+	for (MapReduceMappingsToIntTask<K,V> t = this, s;;) {
7155	+	int c; BulkTask<K,V,?> par;
7156	+	if ((c = t.pending) == 0) {
7157	+	for (s = t.rights; s != null; s = t.rights = s.nextRight) {
7158	+	t.result = reducer.apply(t.result, s.result);
7159	+	}
7160	+	if ((par = t.parent) == null ||
7161	+	!(par instanceof MapReduceMappingsToIntTask)) {
7162	+	t.quietlyComplete();
7163	+	break;
7164	+	}
7165	+	t = (MapReduceMappingsToIntTask<K,V>)par;
7166	+	}
7167	+	else if (t.casPending(c, c - 1))
7168	+	break;
7169	+	}
7170	+	} catch (Throwable ex) {
7171	+	return tryCompleteComputation(ex);
7172	+	}
7173	+	MapReduceMappingsToIntTask<K,V> s = rights;
7174	+	if (s != null && !inForkJoinPool()) {
7175	+	do  {
7176	+	if (s.tryUnfork())
7177	+	s.exec();
7178	+	} while ((s = s.nextRight) != null);
7179	+	}
7180	+	return false;
7181	+	}
7182	+	public final Integer getRawResult() { return result; }
7183	+	}
7184	+
7185	+	// Unsafe mechanics
7186	+	private static final sun.misc.Unsafe UNSAFE;
7187	+	private static final long counterOffset;
7188	+	private static final long sizeCtlOffset;
7189	+	private static final long ABASE;
7190	+	private static final int ASHIFT;
7191	+
7192	+	static {
7193	+	int ss;
7194	+	try {
7195	+	UNSAFE = sun.misc.Unsafe.getUnsafe();
7196	+	Class<?> k = ConcurrentHashMap.class;
7197	+	counterOffset = UNSAFE.objectFieldOffset
7198	+	(k.getDeclaredField("counter"));
7199	+	sizeCtlOffset = UNSAFE.objectFieldOffset
7200	+	(k.getDeclaredField("sizeCtl"));
7201	+	Class<?> sc = Node[].class;
7202	+	ABASE = UNSAFE.arrayBaseOffset(sc);
7203	+	ss = UNSAFE.arrayIndexScale(sc);
7204	+	} catch (Exception e) {
7205	+	throw new Error(e);
7206	+	}
7207	+	if ((ss & (ss-1)) != 0)
7208	+	throw new Error("data type scale not a power of two");
7209	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(ss);
7210		}
7211		}

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