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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.24 by dl, Fri Oct 10 23:51:28 2003 UTC vs.
Revision 1.147 by jsr166, Sat Nov 24 03:46:28 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. Use, modify, and
4	<	* redistribute this code in any way without acknowledgement.
3	>	* Expert Group and released to the public domain, as explained at
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.CountedCompleter;
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>) ordinarily
47	<	* overlap with update operations (including <tt>put</tt> and
48	<	* <tt>remove</tt>). Retrievals reflect the results of the most
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.  For aggregate operations such as <tt>putAll</tt> and
51	<	* <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 <tt>ConcurrentModificationException</tt>.
56	<	* However, Iterators are designed to be used by only one thread at a
57	<	* time.
58	<	*
59	<	* <p> The allowed concurrency among update operations is guided by
60	<	* the optional <tt>concurrencyLevel</tt> constructor argument
61	<	* (default 16), which is used as a hint for internal sizing.  The
62	<	* table is internally partitioned to try to permit the indicated
63	<	* number of concurrent updates without contention. Because placement
64	<	* in hash tables is essentially random, the actual concurrency will
65	<	* vary.  Ideally, you should choose a value to accommodate as many
66	<	* threads as will ever concurrently access the table. Using a
67	<	* significantly higher value than you need can waste space and time,
68	<	* and a significantly lower value can lead to thread contention. But
69	<	* overestimates and underestimates within an order of magnitude do
70	<	* not usually have much noticeable impact.
71	<	*
72	<	* <p>This class implements all of the <em>optional</em> methods
73	<	* of the {@link Map} and {@link Iterator} interfaces.
74	<	*
75	<	* <p> Like {@link java.util.Hashtable} but unlike {@link
76	<	* java.util.HashMap}, this class does NOT allow <tt>null</tt> to be
77	<	* used as a key or value.
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 {@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}/../technotes/guides/collections/index.html">
213	>	* Java Collections Framework</a>.
214		*
215		* @since 1.5
216		* @author Doug Lea
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>, Cloneable, 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 number of table slots for this table.
496	<	* Used when not otherwise specified in 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 int DEFAULT_INITIAL_CAPACITY = 16;
501	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
502
503		/**
504	<	* The maximum capacity, used if a higher value is implicitly
505	<	* specified by either of the constructors with arguments.  MUST
83	<	* be a power of two <= 1<<30 to ensure that entries are indexible
84	<	* using ints.
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 MAXIMUM_CAPACITY = 1 << 30;
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 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 number of concurrency control segments.
517	<	**/
518	<	private static final int DEFAULT_SEGMENTS = 16;
516	>	* The default concurrency level for this table. Unused but
517	>	* defined for compatibility with previous versions of this class.
518	>	*/
519	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
520	>
521	>	/**
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	>	private static final float LOAD_FACTOR = 0.75f;
529
530		/**
531	<	* The maximum number of segments to allow; used to bound ctor 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	<	private static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
535	>	private static final int TRANSFER_BUFFER_SIZE = 32;
536	>
537	>	/**
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 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.
558	<	**/
559	<	private final int segmentMask;
556	>	* The array of bins. Lazily initialized upon first insertion.
557	>	* Size is always a power of two. Accessed directly by iterators.
558	>	*/
559	>	transient volatile Node[] table;
560
561		/**
562	<	* Shift value for indexing within segments.
563	<	**/
564	<	private final int segmentShift;
562	>	* The counter maintaining number of elements.
563	>	*/
564	>	private transient final LongAdder counter;
565
566		/**
567	<	* The segments, each of which is a specialized hash table
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 final Segment[] segments;
573	>	private transient volatile int sizeCtl;
574
575	<	private transient Set<K> keySet;
576	<	private transient Set<Map.Entry<K,V>> entrySet;
577	<	private transient Collection<V> values;
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	<	/* ---------------- Small Utilities -------------- */
580	>	/** For serialization compatibility. Null unless serialized; see below */
581	>	private Segment<K,V>[] segments;
582
583	<	/**
584	<	* Return a hash code for non-null Object x.
585	<	* Uses the same hash code spreader as most other j.u hash tables.
586	<	* @param x the object serving as a key
587	<	* @return the hash code
583	>	/* ---------------- Table element access -------------- */
584	>
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	<	private static int hash(Object x) {
597	<	int h = x.hashCode();
598	<	h += ~(h << 9);
137	<	h ^=  (h >>> 14);
138	<	h +=  (h << 4);
139	<	h ^=  (h >>> 10);
140	<	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	<	* Return the segment that should be used for key with given hash
603	<	*/
604	<	private Segment<K,V> segmentFor(int hash) {
605	<	return (Segment<K,V>) 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	<	* Segments are specialized versions of hash tables.  This
613	<	* subclasses from ReentrantLock opportunistically, just to
614	<	* simplify some locking and avoid separate construction.
615	<	**/
616	<	private static final class Segment<K,V> extends ReentrantLock implements Serializable {
617	<	/*
618	<	* Segments maintain a table of entry lists that are ALWAYS
619	<	* kept in a consistent state, so can be read without locking.
620	<	* Next fields of nodes are immutable (final).  All list
621	<	* additions are performed at the front of each bin. This
622	<	* makes it easy to check changes, and also fast to traverse.
623	<	* When nodes would otherwise be changed, new nodes are
624	<	* created to replace them. This works well for hash tables
625	<	* since the bin lists tend to be short. (The average length
626	<	* is less than two for the default load factor threshold.)
627	<	*
628	<	* Read operations can thus proceed without locking, but rely
629	<	* on a memory barrier to ensure that completed write
630	<	* operations performed by other threads are
631	<	* noticed. Conveniently, the "count" field, tracking the
632	<	* number of elements, can also serve as the volatile variable
633	<	* providing proper read/write barriers. This is convenient
634	<	* because this field needs to be read in many read operations
635	<	* anyway.
636	<	*
637	<	* Implementors note. The basic rules for all this are:
638	<	*
639	<	*   - All unsynchronized read operations must first read the
640	<	*     "count" field, and should not look at table entries if
641	<	*     it is 0.
642	<	*
643	<	*   - All synchronized write operations should write to
644	<	*     the "count" field after updating. The operations must not
645	<	*     take any action that could even momentarily cause
646	<	*     a concurrent read operation to see inconsistent
647	<	*     data. This is made easier by the nature of the read
648	<	*     operations in Map. For example, no operation
190	<	*     can reveal that the table has grown but the threshold
191	<	*     has not yet been updated, so there are no atomicity
192	<	*     requirements for this with respect to reads.
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	>	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;
632	>	}
633	>
634	>	/** CompareAndSet the hash field */
635	>	final boolean casHash(int cmp, int val) {
636	>	return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val);
637	>	}
638	>
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	>	* 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	<	* As a guide, all critical volatile reads and writes are marked
651	<	* in code comments.
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	+	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	+	// Unsafe mechanics for casHash
693	+	private static final sun.misc.Unsafe UNSAFE;
694	+	private static final long hashOffset;
695	+
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	+	/* ---------------- TreeBins -------------- */
709
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	+	/**
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	<	/**
775	<	* The number of elements in this segment's region.
776	<	**/
777	<	transient volatile int count;
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	<	/**
820	<	* Number of updates; used for checking lack of modifications
821	<	* in bulk-read methods.
822	<	*/
823	<	transient int modCount;
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	<	* The table is rehashed when its size exceeds this threshold.
838	<	* (The value of this field is always (int)(capacity *
214	<	* loadFactor).)
837	>	* Returns the TreeNode (or null if not found) for the given key
838	>	* starting at given root.
839		*/
840	<	private transient int threshold;
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	<	* The per-segment table
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	<	transient HashEntry[] table;
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	<	* The load factor for the hash table.  Even though this value
899	<	* is same for all segments, it is replicated to avoid needing
226	<	* links to outer object.
227	<	* @serial
898	>	* Finds or adds a node.
899	>	* @return null if added
900		*/
901	<	private final float loadFactor;
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	>	}
931
932	<	Segment(int initialCapacity, float lf) {
933	<	loadFactor = lf;
934	<	setTable(new HashEntry[initialCapacity]);
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	>	}
992	>	}
993	>	TreeNode r = root;
994	>	if (r != null && r.red)
995	>	r.red = false;
996	>	}
997	>	return null;
998		}
999
1000		/**
1001	<	* Set table to new HashEntry array.
1002	<	* Call only while holding lock or in constructor.
1003	<	**/
1004	<	private void setTable(HashEntry[] newTable) {
1005	<	table = newTable;
1006	<	threshold = (int)(newTable.length * loadFactor);
1007	<	count = count; // write-volatile
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	>	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	<	/* Specialized implementations of map methods */
1171	>	/* ---------------- Collision reduction methods -------------- */
1172
1173	<	V get(K key, int hash) {
1174	<	if (count != 0) { // read-volatile
1175	<	HashEntry[] tab = table;
1176	<	int index = hash & (tab.length - 1);
1177	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1178	<	while (e != null) {
1179	<	if (e.hash == hash && key.equals(e.key))
1180	<	return e.value;
1181	<	e = e.next;
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	>	/* ---------------- 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 null;
1226	>	break;
1227		}
1228	+	return null;
1229	+	}
1230
1231	<	boolean containsKey(Object key, int hash) {
1232	<	if (count != 0) { // read-volatile
1233	<	HashEntry[] tab = table;
1234	<	int index = hash & (tab.length - 1);
1235	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1236	<	while (e != null) {
1237	<	if (e.hash == hash && key.equals(e.key))
1238	<	return true;
1239	<	e = e.next;
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		}
1323		}
273	–	return false;
1324		}
1325	+	return oldVal;
1326	+	}
1327
1328	<	boolean containsValue(Object value) {
1329	<	if (count != 0) { // read-volatile
1330	<	HashEntry[] tab = table;
1331	<	int len = tab.length;
1332	<	for (int i = 0 ; i < len; i++)
1333	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
1334	<	if (value.equals(e.value))
1335	<	return true;
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	>	/** 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	>	}
1434		}
285	–	return false;
1435		}
1436	+	counter.add(1L);
1437	+	if (count > 1)
1438	+	checkForResize();
1439	+	return null;
1440	+	}
1441
1442	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1443	<	lock();
1444	<	try {
1445	<	int c = count;
1446	<	HashEntry[] tab = table;
1447	<	int index = hash & (tab.length - 1);
1448	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1449	<
1450	<	for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
1451	<	if (e.hash == hash && key.equals(e.key)) {
1452	<	V oldValue = e.value;
1453	<	if (!onlyIfAbsent)
1454	<	e.value = value;
1455	<	++modCount;
1456	<	count = c; // write-volatile
1457	<	return oldValue;
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	<	tab[index] = new HashEntry<K,V>(hash, key, value, first);
1544	<	++modCount;
1545	<	++c;
1546	<	count = c; // write-volatile
1547	<	if (c > threshold)
1548	<	setTable(rehash(tab));
1549	<	return null;
1550	<	} finally {
1551	<	unlock();
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	>	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	+	}
1661	+	}
1662	+	}
1663	+	if (val != null) {
1664	+	counter.add(1L);
1665	+	if (count > 1)
1666	+	checkForResize();
1667		}
1668	+	return val;
1669	+	}
1670
1671	<	private HashEntry[] rehash(HashEntry[] oldTable) {
1672	<	int oldCapacity = oldTable.length;
1673	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1674	<	return oldTable;
1675	<
1676	<	/*
1677	<	* Reclassify nodes in each list to new Map.  Because we are
1678	<	* using power-of-two expansion, the elements from each bin
1679	<	* must either stay at same index, or move with a power of two
1680	<	* offset. We eliminate unnecessary node creation by catching
1681	<	* cases where old nodes can be reused because their next
1682	<	* fields won't change. Statistically, at the default
1683	<	* threshhold, only about one-sixth of them need cloning when
1684	<	* a table doubles. The nodes they replace will be garbage
1685	<	* collectable as soon as they are no longer referenced by any
1686	<	* reader thread that may be in the midst of traversing table
1687	<	* right now.
1688	<	*/
1689	<
1690	<	HashEntry[] newTable = new HashEntry[oldCapacity << 1];
1691	<	int sizeMask = newTable.length - 1;
1692	<	for (int i = 0; i < oldCapacity ; i++) {
1693	<	// We need to guarantee that any existing reads of old Map can
1694	<	//  proceed. So we cannot yet null out each bin.
1695	<	HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
1696	<
1697	<	if (e != null) {
1698	<	HashEntry<K,V> next = e.next;
1699	<	int idx = e.hash & sizeMask;
1700	<
1701	<	//  Single node on list
1702	<	if (next == null)
1703	<	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	<	newTable[lastIdx] = lastRun;
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	>	}
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	<	newTable[k] = new HashEntry<K,V>(p.hash,
1908	<	p.key,
1909	<	p.value,
1910	<	(HashEntry<K,V>) newTable[k]);
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	<	return newTable;
1999	>	} finally {
2000	>	if (delta != 0)
2001	>	counter.add(delta);
2002		}
2003	+	if (npe)
2004	+	throw new NullPointerException();
2005	+	}
2006
2007	<	/**
383	<	* Remove; match on key only if value null, else match both.
384	<	*/
385	<	V remove(Object key, int hash, Object value) {
386	<	lock();
387	<	try {
388	<	int c = count;
389	<	HashEntry[] tab = table;
390	<	int index = hash & (tab.length - 1);
391	<	HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
2007	>	/* ---------------- Table Initialization and Resizing -------------- */
2008
2009	<	HashEntry<K,V> e = first;
2010	<	for (;;) {
2011	<	if (e == null)
2012	<	return null;
2013	<	if (e.hash == hash && key.equals(e.key))
2014	<	break;
2015	<	e = e.next;
2016	<	}
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	<	V oldValue = e.value;
2024	<	if (value != null && !value.equals(oldValue))
2025	<	return null;
2026	<
2027	<	// All entries following removed node can stay in list, but
2028	<	// all preceeding ones need to be cloned.
2029	<	HashEntry<K,V> newFirst = e.next;
2030	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
2031	<	newFirst = new HashEntry<K,V>(p.hash, p.key,
2032	<	p.value, newFirst);
2033	<	tab[index] = newFirst;
2034	<	++modCount;
2035	<	count = c-1; // write-volatile
2036	<	return oldValue;
2037	<	} finally {
2038	<	unlock();
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	<	void clear() {
2048	<	lock();
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	<	HashEntry[] tab = table;
2061	<	for (int i = 0; i < tab.length ; i++)
2062	<	tab[i] = null;
2063	<	++modCount;
428	<	count = 0; // write-volatile
2060	>	if (tab == table) {
2061	>	table = rebuild(tab);
2062	>	sc = (n << 1) - (n >>> 1);
2063	>	}
2064		} finally {
2065	<	unlock();
2065	>	sizeCtl = sc;
2066		}
2067		}
2068		}
2069
2070		/**
2071	<	* ConcurrentHashMap list entry.
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 static class HashEntry<K,V> implements Entry<K,V> {
2076	<	private final K key;
2077	<	private V value;
2078	<	private final int hash;
2079	<	private final HashEntry<K,V> next;
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	>	if (table == tab) {
2099	>	table = rebuild(tab);
2100	>	sc = (n << 1) - (n >>> 1);
2101	>	}
2102	>	} finally {
2103	>	sizeCtl = sc;
2104	>	}
2105	>	}
2106	>	}
2107	>	}
2108
2109	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
2110	<	this.value = value;
2111	<	this.hash = hash;
2112	<	this.key = key;
2113	<	this.next = next;
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	<	public K getKey() {
2215	<	return key;
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	<	public V getValue() {
2246	<	return value;
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 V setValue(V newValue) {
2285	<	// We aren't required to, and don't provide any
2286	<	// visibility barriers for setting value.
2287	<	if (newValue == null)
2288	<	throw new NullPointerException();
2289	<	V oldValue = this.value;
2290	<	this.value = newValue;
2291	<	return oldValue;
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	<	public boolean equals(Object o) {
2350	<	if (!(o instanceof Entry))
2351	<	return false;
2352	<	Entry<K,V> e = (Entry<K,V>)o;
2353	<	return (key.equals(e.getKey()) && value.equals(e.getValue()));
2349	>	/* ----------------Table Traversal -------------- */
2350	>
2351	>	/**
2352	>	* Encapsulates traversal for methods such as containsValue; also
2353	>	* serves as a base class for other iterators and bulk tasks.
2354	>	*
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 CountedCompleter to streamline parallel
2390	>	* iteration in bulk operations. This adds only a few fields of
2391	>	* space overhead, which is small enough in cases where it is not
2392	>	* needed to not worry about it.  Because CountedCompleter is
2393	>	* Serializable, but iterators need not be, we need to add warning
2394	>	* suppressions.
2395	>	*/
2396	>	@SuppressWarnings("serial") static class Traverser<K,V,R> extends CountedCompleter<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	>	int batch;           // split control
2407	>
2408	>	/** Creates iterator for all entries in the table. */
2409	>	Traverser(ConcurrentHashMap<K, V> map) {
2410	>	this.map = map;
2411	>	}
2412	>
2413	>	/** Creates iterator for split() methods and task constructors */
2414	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it, int batch) {
2415	>	super(it);
2416	>	this.batch = batch;
2417	>	if ((this.map = map) != null && it != null) { // split parent
2418	>	Node[] t;
2419	>	if ((t = it.tab) == null &&
2420	>	(t = it.tab = map.table) != null)
2421	>	it.baseLimit = it.baseSize = t.length;
2422	>	this.tab = t;
2423	>	this.baseSize = it.baseSize;
2424	>	int hi = this.baseLimit = it.baseLimit;
2425	>	it.baseLimit = this.index = this.baseIndex =
2426	>	(hi + it.baseIndex + 1) >>> 1;
2427	>	}
2428	>	}
2429	>
2430	>	/**
2431	>	* Advances next; returns nextVal or null if terminated.
2432	>	* See above for explanation.
2433	>	*/
2434	>	final Object advance() {
2435	>	Node e = next;
2436	>	Object ev = null;
2437	>	outer: do {
2438	>	if (e != null)                  // advance past used/skipped node
2439	>	e = e.next;
2440	>	while (e == null) {             // get to next non-null bin
2441	>	ConcurrentHashMap<K, V> m;
2442	>	Node[] t; int b, i, n; Object ek; // checks must use locals
2443	>	if ((t = tab) != null)
2444	>	n = t.length;
2445	>	else if ((m = map) != null && (t = tab = m.table) != null)
2446	>	n = baseLimit = baseSize = t.length;
2447	>	else
2448	>	break outer;
2449	>	if ((b = baseIndex) >= baseLimit ||
2450	>	(i = index) < 0 || i >= n)
2451	>	break outer;
2452	>	if ((e = tabAt(t, i)) != null && e.hash == MOVED) {
2453	>	if ((ek = e.key) instanceof TreeBin)
2454	>	e = ((TreeBin)ek).first;
2455	>	else {
2456	>	tab = (Node[])ek;
2457	>	continue;           // restarts due to null val
2458	>	}
2459	>	}                           // visit upper slots if present
2460	>	index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2461	>	}
2462	>	nextKey = e.key;
2463	>	} while ((ev = e.val) == null);    // skip deleted or special nodes
2464	>	next = e;
2465	>	return nextVal = ev;
2466		}
2467
2468	<	public int hashCode() {
2469	<	return  key.hashCode() ^ value.hashCode();
2468	>	public final void remove() {
2469	>	Object k = nextKey;
2470	>	if (k == null && (advance() == null || (k = nextKey) == null))
2471	>	throw new IllegalStateException();
2472	>	map.internalReplace(k, null, null);
2473		}
2474
2475	<	public String toString() {
2476	<	return key + "=" + value;
2475	>	public final boolean hasNext() {
2476	>	return nextVal != null || advance() != null;
2477	>	}
2478	>
2479	>	public final boolean hasMoreElements() { return hasNext(); }
2480	>
2481	>	public void compute() { } // default no-op CountedCompleter body
2482	>
2483	>	/**
2484	>	* Returns a batch value > 0 if this task should (and must) be
2485	>	* split, if so, adding to pending count, and in any case
2486	>	* updating batch value. The initial batch value is approx
2487	>	* exp2 of the number of times (minus one) to split task by
2488	>	* two before executing leaf action. This value is faster to
2489	>	* compute and more convenient to use as a guide to splitting
2490	>	* than is the depth, since it is used while dividing by two
2491	>	* anyway.
2492	>	*/
2493	>	final int preSplit() {
2494	>	ConcurrentHashMap<K, V> m; int b; Node[] t;  ForkJoinPool pool;
2495	>	if ((b = batch) < 0 && (m = map) != null) { // force initialization
2496	>	if ((t = tab) == null && (t = tab = m.table) != null)
2497	>	baseLimit = baseSize = t.length;
2498	>	if (t != null) {
2499	>	long n = m.counter.sum();
2500	>	int par = ((pool = getPool()) == null) ?
2501	>	ForkJoinPool.getCommonPoolParallelism() :
2502	>	pool.getParallelism();
2503	>	int sp = par << 3; // slack of 8
2504	>	b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2505	>	}
2506	>	}
2507	>	b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1);
2508	>	if ((batch = b) > 0)
2509	>	addToPendingCount(1);
2510	>	return b;
2511		}
483	–	}
2512
2513	+	}
2514
2515		/* ---------------- Public operations -------------- */
2516
2517		/**
2518	<	* Constructs a new, empty map with the specified initial
2519	<	* capacity and the specified load factor.
2518	>	* Creates a new, empty map with the default initial table size (16).
2519	>	*/
2520	>	public ConcurrentHashMap() {
2521	>	this.counter = new LongAdder();
2522	>	}
2523	>
2524	>	/**
2525	>	* Creates a new, empty map with an initial table size
2526	>	* accommodating the specified number of elements without the need
2527	>	* to dynamically resize.
2528	>	*
2529	>	* @param initialCapacity The implementation performs internal
2530	>	* sizing to accommodate this many elements.
2531	>	* @throws IllegalArgumentException if the initial capacity of
2532	>	* elements is negative
2533	>	*/
2534	>	public ConcurrentHashMap(int initialCapacity) {
2535	>	if (initialCapacity < 0)
2536	>	throw new IllegalArgumentException();
2537	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2538	>	MAXIMUM_CAPACITY :
2539	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2540	>	this.counter = new LongAdder();
2541	>	this.sizeCtl = cap;
2542	>	}
2543	>
2544	>	/**
2545	>	* Creates a new map with the same mappings as the given map.
2546	>	*
2547	>	* @param m the map
2548	>	*/
2549	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2550	>	this.counter = new LongAdder();
2551	>	this.sizeCtl = DEFAULT_CAPACITY;
2552	>	internalPutAll(m);
2553	>	}
2554	>
2555	>	/**
2556	>	* Creates a new, empty map with an initial table size based on
2557	>	* the given number of elements ({@code initialCapacity}) and
2558	>	* initial table density ({@code loadFactor}).
2559	>	*
2560	>	* @param initialCapacity the initial capacity. The implementation
2561	>	* performs internal sizing to accommodate this many elements,
2562	>	* given the specified load factor.
2563	>	* @param loadFactor the load factor (table density) for
2564	>	* establishing the initial table size
2565	>	* @throws IllegalArgumentException if the initial capacity of
2566	>	* elements is negative or the load factor is nonpositive
2567	>	*
2568	>	* @since 1.6
2569	>	*/
2570	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2571	>	this(initialCapacity, loadFactor, 1);
2572	>	}
2573	>
2574	>	/**
2575	>	* Creates a new, empty map with an initial table size based on
2576	>	* the given number of elements ({@code initialCapacity}), table
2577	>	* density ({@code loadFactor}), and number of concurrently
2578	>	* updating threads ({@code concurrencyLevel}).
2579		*
2580		* @param initialCapacity the initial capacity. The implementation
2581	<	* performs internal sizing to accommodate this many elements.
2582	<	* @param loadFactor  the load factor threshold, used to control resizing.
2581	>	* performs internal sizing to accommodate this many elements,
2582	>	* given the specified load factor.
2583	>	* @param loadFactor the load factor (table density) for
2584	>	* establishing the initial table size
2585		* @param concurrencyLevel the estimated number of concurrently
2586	<	* updating threads. The implementation performs internal sizing
2587	<	* to try to accommodate this many threads.
2586	>	* updating threads. The implementation may use this value as
2587	>	* a sizing hint.
2588		* @throws IllegalArgumentException if the initial capacity is
2589		* negative or the load factor or concurrencyLevel are
2590	<	* nonpositive.
2590	>	* nonpositive
2591		*/
2592		public ConcurrentHashMap(int initialCapacity,
2593	<	float loadFactor, int concurrencyLevel) {
2594	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2593	>	float loadFactor, int concurrencyLevel) {
2594	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2595		throw new IllegalArgumentException();
2596	+	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2597	+	initialCapacity = concurrencyLevel;   // as estimated threads
2598	+	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2599	+	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2600	+	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2601	+	this.counter = new LongAdder();
2602	+	this.sizeCtl = cap;
2603	+	}
2604
2605	<	if (concurrencyLevel > MAX_SEGMENTS)
2606	<	concurrencyLevel = MAX_SEGMENTS;
2607	<
2608	<	// Find power-of-two sizes best matching arguments
2609	<	int sshift = 0;
2610	<	int ssize = 1;
2611	<	while (ssize < concurrencyLevel) {
2612	<	++sshift;
2613	<	ssize <<= 1;
516	<	}
517	<	segmentShift = 32 - sshift;
518	<	segmentMask = ssize - 1;
519	<	this.segments = new Segment[ssize];
520	<
521	<	if (initialCapacity > MAXIMUM_CAPACITY)
522	<	initialCapacity = MAXIMUM_CAPACITY;
523	<	int c = initialCapacity / ssize;
524	<	if (c * ssize < initialCapacity)
525	<	++c;
526	<	int cap = 1;
527	<	while (cap < c)
528	<	cap <<= 1;
529	<
530	<	for (int i = 0; i < this.segments.length; ++i)
531	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2605	>	/**
2606	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2607	>	* from the given type to {@code Boolean.TRUE}.
2608	>	*
2609	>	* @return the new set
2610	>	*/
2611	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2612	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(),
2613	>	Boolean.TRUE);
2614		}
2615
2616		/**
2617	<	* Constructs a new, empty map with the specified initial
2618	<	* capacity,  and with default load factor and concurrencyLevel.
2617	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2618	>	* from the given type to {@code Boolean.TRUE}.
2619		*
2620		* @param initialCapacity The implementation performs internal
2621		* sizing to accommodate this many elements.
2622		* @throws IllegalArgumentException if the initial capacity of
2623	<	* elements is negative.
2623	>	* elements is negative
2624	>	* @return the new set
2625		*/
2626	<	public ConcurrentHashMap(int initialCapacity) {
2627	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2626	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2627	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(initialCapacity),
2628	>	Boolean.TRUE);
2629		}
2630
2631		/**
2632	<	* Constructs a new, empty map with a default initial capacity,
549	<	* load factor, and concurrencyLevel.
2632	>	* {@inheritDoc}
2633		*/
2634	<	public ConcurrentHashMap() {
2635	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2634	>	public boolean isEmpty() {
2635	>	return counter.sum() <= 0L; // ignore transient negative values
2636		}
2637
2638		/**
2639	<	* Constructs a new map with the same mappings as the given map.  The
557	<	* map is created with a capacity of twice the number of mappings in
558	<	* the given map or 11 (whichever is greater), and a default load factor.
2639	>	* {@inheritDoc}
2640		*/
2641	<	public <A extends K, B extends V> ConcurrentHashMap(Map<A,B> t) {
2642	<	this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
2643	<	11),
2644	<	DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2645	<	putAll(t);
2641	>	public int size() {
2642	>	long n = counter.sum();
2643	>	return ((n < 0L) ? 0 :
2644	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2645	>	(int)n);
2646		}
2647
2648	<	// inherit Map javadoc
2649	<	public boolean isEmpty() {
2650	<	/*
2651	<	* We need to keep track of per-segment modCounts to avoid ABA
2652	<	* problems in which an element in one segment was added and
2653	<	* in another removed during traversal, in which case the
2654	<	* table was never actually empty at any point. Note the
2655	<	* similar use of modCounts in the size() and containsValue()
2656	<	* methods, which are the only other methods also susceptible
2657	<	* to ABA problems.
2658	<	*/
2659	<	int[] mc = new int[segments.length];
579	<	int mcsum = 0;
580	<	for (int i = 0; i < segments.length; ++i) {
581	<	if (segments[i].count != 0)
582	<	return false;
583	<	else
584	<	mcsum += mc[i] = segments[i].modCount;
585	<	}
586	<	// If mcsum happens to be zero, then we know we got a snapshot
587	<	// before any modifications at all were made.  This is
588	<	// probably common enough to bother tracking.
589	<	if (mcsum != 0) {
590	<	for (int i = 0; i < segments.length; ++i) {
591	<	if (segments[i].count != 0 ||
592	<	mc[i] != segments[i].modCount)
593	<	return false;
594	<	}
595	<	}
596	<	return true;
2648	>	/**
2649	>	* Returns the number of mappings. This method should be used
2650	>	* instead of {@link #size} because a ConcurrentHashMap may
2651	>	* contain more mappings than can be represented as an int. The
2652	>	* value returned is an estimate; the actual count may differ if
2653	>	* there are concurrent insertions or removals.
2654	>	*
2655	>	* @return the number of mappings
2656	>	*/
2657	>	public long mappingCount() {
2658	>	long n = counter.sum();
2659	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2660		}
2661
2662	<	// inherit Map javadoc
2663	<	public int size() {
2664	<	int[] mc = new int[segments.length];
2665	<	for (;;) {
2666	<	long sum = 0;
2667	<	int mcsum = 0;
2668	<	for (int i = 0; i < segments.length; ++i) {
2669	<	sum += segments[i].count;
2670	<	mcsum += mc[i] = segments[i].modCount;
2671	<	}
2672	<	int check = 0;
2673	<	if (mcsum != 0) {
2674	<	for (int i = 0; i < segments.length; ++i) {
2675	<	check += segments[i].count;
2676	<	if (mc[i] != segments[i].modCount) {
614	<	check = -1; // force retry
615	<	break;
616	<	}
617	<	}
618	<	}
619	<	if (check == sum) {
620	<	if (sum > Integer.MAX_VALUE)
621	<	return Integer.MAX_VALUE;
622	<	else
623	<	return (int)sum;
624	<	}
625	<	}
2662	>	/**
2663	>	* Returns the value to which the specified key is mapped,
2664	>	* or {@code null} if this map contains no mapping for the key.
2665	>	*
2666	>	* <p>More formally, if this map contains a mapping from a key
2667	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
2668	>	* then this method returns {@code v}; otherwise it returns
2669	>	* {@code null}.  (There can be at most one such mapping.)
2670	>	*
2671	>	* @throws NullPointerException if the specified key is null
2672	>	*/
2673	>	@SuppressWarnings("unchecked") public V get(Object key) {
2674	>	if (key == null)
2675	>	throw new NullPointerException();
2676	>	return (V)internalGet(key);
2677		}
2678
628	–
2679		/**
2680	<	* Returns the value to which the specified key is mapped in this table.
2680	>	* Returns the value to which the specified key is mapped,
2681	>	* or the given defaultValue if this map contains no mapping for the key.
2682		*
2683	<	* @param   key   a key in the table.
2684	<	* @return  the value to which the key is mapped in this table;
2685	<	*          <tt>null</tt> if the key is not mapped to any value in
2686	<	*          this table.
2687	<	* @throws  NullPointerException  if the key is
637	<	*               <tt>null</tt>.
2683	>	* @param key the key
2684	>	* @param defaultValue the value to return if this map contains
2685	>	* no mapping for the given key
2686	>	* @return the mapping for the key, if present; else the defaultValue
2687	>	* @throws NullPointerException if the specified key is null
2688		*/
2689	<	public V get(Object key) {
2690	<	int hash = hash(key); // throws NullPointerException if key null
2691	<	return segmentFor(hash).get((K) key, hash);
2689	>	@SuppressWarnings("unchecked") public V getValueOrDefault(Object key, V defaultValue) {
2690	>	if (key == null)
2691	>	throw new NullPointerException();
2692	>	V v = (V) internalGet(key);
2693	>	return v == null ? defaultValue : v;
2694		}
2695
2696		/**
2697		* Tests if the specified object is a key in this table.
2698		*
2699	<	* @param   key   possible key.
2700	<	* @return  <tt>true</tt> if and only if the specified object
2701	<	*          is a key in this table, as determined by the
2702	<	*          <tt>equals</tt> method; <tt>false</tt> otherwise.
2703	<	* @throws  NullPointerException  if the key is
652	<	*               <tt>null</tt>.
2699	>	* @param  key   possible key
2700	>	* @return {@code true} if and only if the specified object
2701	>	*         is a key in this table, as determined by the
2702	>	*         {@code equals} method; {@code false} otherwise
2703	>	* @throws NullPointerException if the specified key is null
2704		*/
2705		public boolean containsKey(Object key) {
2706	<	int hash = hash(key); // throws NullPointerException if key null
2707	<	return segmentFor(hash).containsKey(key, hash);
2706	>	if (key == null)
2707	>	throw new NullPointerException();
2708	>	return internalGet(key) != null;
2709		}
2710
2711		/**
2712	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2713	<	* specified value. Note: This method requires a full internal
2714	<	* traversal of the hash table, and so is much slower than
663	<	* method <tt>containsKey</tt>.
2712	>	* Returns {@code true} if this map maps one or more keys to the
2713	>	* specified value. Note: This method may require a full traversal
2714	>	* of the map, and is much slower than method {@code containsKey}.
2715		*
2716	<	* @param value value whose presence in this map is to be tested.
2717	<	* @return <tt>true</tt> if this map maps one or more keys to the
2718	<	* specified value.
2719	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2716	>	* @param value value whose presence in this map is to be tested
2717	>	* @return {@code true} if this map maps one or more keys to the
2718	>	*         specified value
2719	>	* @throws NullPointerException if the specified value is null
2720		*/
2721		public boolean containsValue(Object value) {
2722		if (value == null)
2723		throw new NullPointerException();
2724	<
2725	<	int[] mc = new int[segments.length];
2726	<	for (;;) {
2727	<	int sum = 0;
2728	<	int mcsum = 0;
678	<	for (int i = 0; i < segments.length; ++i) {
679	<	int c = segments[i].count;
680	<	mcsum += mc[i] = segments[i].modCount;
681	<	if (segments[i].containsValue(value))
682	<	return true;
683	<	}
684	<	boolean cleanSweep = true;
685	<	if (mcsum != 0) {
686	<	for (int i = 0; i < segments.length; ++i) {
687	<	int c = segments[i].count;
688	<	if (mc[i] != segments[i].modCount) {
689	<	cleanSweep = false;
690	<	break;
691	<	}
692	<	}
693	<	}
694	<	if (cleanSweep)
695	<	return false;
2724	>	Object v;
2725	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2726	>	while ((v = it.advance()) != null) {
2727	>	if (v == value || value.equals(v))
2728	>	return true;
2729		}
2730	+	return false;
2731		}
2732
2733		/**
2734		* Legacy method testing if some key maps into the specified value
2735		* in this table.  This method is identical in functionality to
2736	<	* {@link #containsValue}, and  exists solely to ensure
2736	>	* {@link #containsValue}, and exists solely to ensure
2737		* full compatibility with class {@link java.util.Hashtable},
2738		* which supported this method prior to introduction of the
2739		* Java Collections framework.
2740	<
2741	<	* @param      value   a value to search for.
2742	<	* @return     <tt>true</tt> if and only if some key maps to the
2743	<	*             <tt>value</tt> argument in this table as
2744	<	*             determined by the <tt>equals</tt> method;
2745	<	*             <tt>false</tt> otherwise.
2746	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2740	>	*
2741	>	* @param  value a value to search for
2742	>	* @return {@code true} if and only if some key maps to the
2743	>	*         {@code value} argument in this table as
2744	>	*         determined by the {@code equals} method;
2745	>	*         {@code false} otherwise
2746	>	* @throws NullPointerException if the specified value is null
2747		*/
2748		public boolean contains(Object value) {
2749		return containsValue(value);
2750		}
2751
2752		/**
2753	<	* Maps the specified <tt>key</tt> to the specified
2754	<	* <tt>value</tt> in this table. Neither the key nor the
721	<	* value can be <tt>null</tt>. <p>
2753	>	* Maps the specified key to the specified value in this table.
2754	>	* Neither the key nor the value can be null.
2755		*
2756	<	* The value can be retrieved by calling the <tt>get</tt> method
2756	>	* <p>The value can be retrieved by calling the {@code get} method
2757		* with a key that is equal to the original key.
2758		*
2759	<	* @param      key     the table key.
2760	<	* @param      value   the value.
2761	<	* @return     the previous value of the specified key in this table,
2762	<	*             or <tt>null</tt> if it did not have one.
2763	<	* @throws  NullPointerException  if the key or value is
731	<	*               <tt>null</tt>.
2759	>	* @param key key with which the specified value is to be associated
2760	>	* @param value value to be associated with the specified key
2761	>	* @return the previous value associated with {@code key}, or
2762	>	*         {@code null} if there was no mapping for {@code key}
2763	>	* @throws NullPointerException if the specified key or value is null
2764		*/
2765	<	public V put(K key, V value) {
2766	<	if (value == null)
2765	>	@SuppressWarnings("unchecked") public V put(K key, V value) {
2766	>	if (key == null || value == null)
2767		throw new NullPointerException();
2768	<	int hash = hash(key);
737	<	return segmentFor(hash).put(key, hash, value, false);
2768	>	return (V)internalPut(key, value);
2769		}
2770
2771		/**
2772	<	* If the specified key is not already associated
742	<	* with a value, associate it with the given value.
743	<	* This is equivalent to
744	<	* <pre>
745	<	*   if (!map.containsKey(key))
746	<	*      return map.put(key, value);
747	<	*   else
748	<	*      return map.get(key);
749	<	* </pre>
750	<	* Except that the action is performed atomically.
751	<	* @param key key with which the specified value is to be associated.
752	<	* @param value value to be associated with the specified key.
753	<	* @return previous value associated with specified key, or <tt>null</tt>
754	<	*         if there was no mapping for key.  A <tt>null</tt> return can
755	<	*         also indicate that the map previously associated <tt>null</tt>
756	<	*         with the specified key, if the implementation supports
757	<	*         <tt>null</tt> values.
758	<	*
759	<	* @throws UnsupportedOperationException if the <tt>put</tt> operation is
760	<	*            not supported by this map.
761	<	* @throws ClassCastException if the class of the specified key or value
762	<	*            prevents it from being stored in this map.
763	<	* @throws NullPointerException if the specified key or value is
764	<	*            <tt>null</tt>.
2772	>	* {@inheritDoc}
2773		*
2774	<	**/
2775	<	public V putIfAbsent(K key, V value) {
2776	<	if (value == null)
2774	>	* @return the previous value associated with the specified key,
2775	>	*         or {@code null} if there was no mapping for the key
2776	>	* @throws NullPointerException if the specified key or value is null
2777	>	*/
2778	>	@SuppressWarnings("unchecked") public V putIfAbsent(K key, V value) {
2779	>	if (key == null || value == null)
2780		throw new NullPointerException();
2781	<	int hash = hash(key);
771	<	return segmentFor(hash).put(key, hash, value, true);
2781	>	return (V)internalPutIfAbsent(key, value);
2782		}
2783
774	–
2784		/**
2785		* Copies all of the mappings from the specified map to this one.
777	–	*
2786		* These mappings replace any mappings that this map had for any of the
2787	<	* keys currently in the specified Map.
2787	>	* keys currently in the specified map.
2788		*
2789	<	* @param t Mappings to be stored in this map.
2789	>	* @param m mappings to be stored in this map
2790		*/
2791	<	public void putAll(Map<? extends K, ? extends V> t) {
2792	<	for (Iterator<Map.Entry<? extends K, ? extends V>> it = (Iterator<Map.Entry<? extends K, ? extends V>>) t.entrySet().iterator(); it.hasNext(); ) {
2793	<	Entry<? extends K, ? extends V> e = it.next();
2794	<	put(e.getKey(), e.getValue());
2795	<	}
2791	>	public void putAll(Map<? extends K, ? extends V> m) {
2792	>	internalPutAll(m);
2793	>	}
2794	>
2795	>	/**
2796	>	* If the specified key is not already associated with a value,
2797	>	* computes its value using the given mappingFunction and enters
2798	>	* it into the map unless null.  This is equivalent to
2799	>	* <pre> {@code
2800	>	* if (map.containsKey(key))
2801	>	*   return map.get(key);
2802	>	* value = mappingFunction.apply(key);
2803	>	* if (value != null)
2804	>	*   map.put(key, value);
2805	>	* return value;}</pre>
2806	>	*
2807	>	* except that the action is performed atomically.  If the
2808	>	* function returns {@code null} no mapping is recorded. If the
2809	>	* function itself throws an (unchecked) exception, the exception
2810	>	* is rethrown to its caller, and no mapping is recorded.  Some
2811	>	* attempted update operations on this map by other threads may be
2812	>	* blocked while computation is in progress, so the computation
2813	>	* should be short and simple, and must not attempt to update any
2814	>	* other mappings of this Map. The most appropriate usage is to
2815	>	* construct a new object serving as an initial mapped value, or
2816	>	* memoized result, as in:
2817	>	*
2818	>	*  <pre> {@code
2819	>	* map.computeIfAbsent(key, new Fun<K, V>() {
2820	>	*   public V map(K k) { return new Value(f(k)); }});}</pre>
2821	>	*
2822	>	* @param key key with which the specified value is to be associated
2823	>	* @param mappingFunction the function to compute a value
2824	>	* @return the current (existing or computed) value associated with
2825	>	*         the specified key, or null if the computed value is null
2826	>	* @throws NullPointerException if the specified key or mappingFunction
2827	>	*         is null
2828	>	* @throws IllegalStateException if the computation detectably
2829	>	*         attempts a recursive update to this map that would
2830	>	*         otherwise never complete
2831	>	* @throws RuntimeException or Error if the mappingFunction does so,
2832	>	*         in which case the mapping is left unestablished
2833	>	*/
2834	>	@SuppressWarnings("unchecked") public V computeIfAbsent
2835	>	(K key, Fun<? super K, ? extends V> mappingFunction) {
2836	>	if (key == null || mappingFunction == null)
2837	>	throw new NullPointerException();
2838	>	return (V)internalComputeIfAbsent(key, mappingFunction);
2839		}
2840
2841		/**
2842	<	* Removes the key (and its corresponding value) from this
2843	<	* table. This method does nothing if the key is not in the table.
2842	>	* If the given key is present, computes a new mapping value given a key and
2843	>	* its current mapped value. This is equivalent to
2844	>	*  <pre> {@code
2845	>	*   if (map.containsKey(key)) {
2846	>	*     value = remappingFunction.apply(key, map.get(key));
2847	>	*     if (value != null)
2848	>	*       map.put(key, value);
2849	>	*     else
2850	>	*       map.remove(key);
2851	>	*   }
2852	>	* }</pre>
2853		*
2854	<	* @param   key   the key that needs to be removed.
2855	<	* @return  the value to which the key had been mapped in this table,
2856	<	*          or <tt>null</tt> if the key did not have a mapping.
2857	<	* @throws  NullPointerException  if the key is
2858	<	*               <tt>null</tt>.
2854	>	* except that the action is performed atomically.  If the
2855	>	* function returns {@code null}, the mapping is removed.  If the
2856	>	* function itself throws an (unchecked) exception, the exception
2857	>	* is rethrown to its caller, and the current mapping is left
2858	>	* unchanged.  Some attempted update operations on this map by
2859	>	* other threads may be blocked while computation is in progress,
2860	>	* so the computation should be short and simple, and must not
2861	>	* attempt to update any other mappings of this Map. For example,
2862	>	* to either create or append new messages to a value mapping:
2863	>	*
2864	>	* @param key key with which the specified value is to be associated
2865	>	* @param remappingFunction the function to compute a value
2866	>	* @return the new value associated with the specified key, or null if none
2867	>	* @throws NullPointerException if the specified key or remappingFunction
2868	>	*         is null
2869	>	* @throws IllegalStateException if the computation detectably
2870	>	*         attempts a recursive update to this map that would
2871	>	*         otherwise never complete
2872	>	* @throws RuntimeException or Error if the remappingFunction does so,
2873	>	*         in which case the mapping is unchanged
2874		*/
2875	<	public V remove(Object key) {
2876	<	int hash = hash(key);
2877	<	return segmentFor(hash).remove(key, hash, null);
2875	>	@SuppressWarnings("unchecked") public V computeIfPresent
2876	>	(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2877	>	if (key == null || remappingFunction == null)
2878	>	throw new NullPointerException();
2879	>	return (V)internalCompute(key, true, remappingFunction);
2880		}
2881
2882		/**
2883	<	* Remove entry for key only if currently mapped to given value.
2884	<	* Acts as
2885	<	* <pre>
2886	<	*  if (map.get(key).equals(value)) {
2883	>	* Computes a new mapping value given a key and
2884	>	* its current mapped value (or {@code null} if there is no current
2885	>	* mapping). This is equivalent to
2886	>	*  <pre> {@code
2887	>	*   value = remappingFunction.apply(key, map.get(key));
2888	>	*   if (value != null)
2889	>	*     map.put(key, value);
2890	>	*   else
2891		*     map.remove(key);
2892	<	*     return true;
2893	<	* } else return false;
2894	<	* </pre>
2895	<	* except that the action is performed atomically.
2896	<	* @param key key with which the specified value is associated.
2897	<	* @param value value associated with the specified key.
2898	<	* @return true if the value was removed
2899	<	* @throws NullPointerException if the specified key is
2900	<	*            <tt>null</tt>.
2892	>	* }</pre>
2893	>	*
2894	>	* except that the action is performed atomically.  If the
2895	>	* function returns {@code null}, the mapping is removed.  If the
2896	>	* function itself throws an (unchecked) exception, the exception
2897	>	* is rethrown to its caller, and the current mapping is left
2898	>	* unchanged.  Some attempted update operations on this map by
2899	>	* other threads may be blocked while computation is in progress,
2900	>	* so the computation should be short and simple, and must not
2901	>	* attempt to update any other mappings of this Map. For example,
2902	>	* to either create or append new messages to a value mapping:
2903	>	*
2904	>	* <pre> {@code
2905	>	* Map<Key, String> map = ...;
2906	>	* final String msg = ...;
2907	>	* map.compute(key, new BiFun<Key, String, String>() {
2908	>	*   public String apply(Key k, String v) {
2909	>	*    return (v == null) ? msg : v + msg;});}}</pre>
2910	>	*
2911	>	* @param key key with which the specified value is to be associated
2912	>	* @param remappingFunction the function to compute a value
2913	>	* @return the new value associated with the specified key, or null if none
2914	>	* @throws NullPointerException if the specified key or remappingFunction
2915	>	*         is null
2916	>	* @throws IllegalStateException if the computation detectably
2917	>	*         attempts a recursive update to this map that would
2918	>	*         otherwise never complete
2919	>	* @throws RuntimeException or Error if the remappingFunction does so,
2920	>	*         in which case the mapping is unchanged
2921		*/
2922	<	public boolean remove(Object key, Object value) {
2923	<	int hash = hash(key);
2924	<	return segmentFor(hash).remove(key, hash, value) != null;
2922	>	@SuppressWarnings("unchecked") public V compute
2923	>	(K key, BiFun<? super K, ? super V, ? extends V> remappingFunction) {
2924	>	if (key == null || remappingFunction == null)
2925	>	throw new NullPointerException();
2926	>	return (V)internalCompute(key, false, remappingFunction);
2927		}
2928
2929		/**
2930	<	* Removes all mappings from this map.
2930	>	* If the specified key is not already associated
2931	>	* with a value, associate it with the given value.
2932	>	* Otherwise, replace the value with the results of
2933	>	* the given remapping function. This is equivalent to:
2934	>	*  <pre> {@code
2935	>	*   if (!map.containsKey(key))
2936	>	*     map.put(value);
2937	>	*   else {
2938	>	*     newValue = remappingFunction.apply(map.get(key), value);
2939	>	*     if (value != null)
2940	>	*       map.put(key, value);
2941	>	*     else
2942	>	*       map.remove(key);
2943	>	*   }
2944	>	* }</pre>
2945	>	* except that the action is performed atomically.  If the
2946	>	* function returns {@code null}, the mapping is removed.  If the
2947	>	* function itself throws an (unchecked) exception, the exception
2948	>	* is rethrown to its caller, and the current mapping is left
2949	>	* unchanged.  Some attempted update operations on this map by
2950	>	* other threads may be blocked while computation is in progress,
2951	>	* so the computation should be short and simple, and must not
2952	>	* attempt to update any other mappings of this Map.
2953		*/
2954	<	public void clear() {
2955	<	for (int i = 0; i < segments.length; ++i)
2956	<	segments[i].clear();
2954	>	@SuppressWarnings("unchecked") public V merge
2955	>	(K key, V value, BiFun<? super V, ? super V, ? extends V> remappingFunction) {
2956	>	if (key == null || value == null || remappingFunction == null)
2957	>	throw new NullPointerException();
2958	>	return (V)internalMerge(key, value, remappingFunction);
2959		}
2960
2961	+	/**
2962	+	* Removes the key (and its corresponding value) from this map.
2963	+	* This method does nothing if the key is not in the map.
2964	+	*
2965	+	* @param  key the key that needs to be removed
2966	+	* @return the previous value associated with {@code key}, or
2967	+	*         {@code null} if there was no mapping for {@code key}
2968	+	* @throws NullPointerException if the specified key is null
2969	+	*/
2970	+	@SuppressWarnings("unchecked") public V remove(Object key) {
2971	+	if (key == null)
2972	+	throw new NullPointerException();
2973	+	return (V)internalReplace(key, null, null);
2974	+	}
2975
2976		/**
2977	<	* Returns a shallow copy of this
837	<	* <tt>ConcurrentHashMap</tt> instance: the keys and
838	<	* values themselves are not cloned.
2977	>	* {@inheritDoc}
2978		*
2979	<	* @return a shallow copy of this map.
2979	>	* @throws NullPointerException if the specified key is null
2980		*/
2981	<	public Object clone() {
2982	<	// We cannot call super.clone, since it would share final
2983	<	// segments array, and there's no way to reassign finals.
2981	>	public boolean remove(Object key, Object value) {
2982	>	if (key == null)
2983	>	throw new NullPointerException();
2984	>	if (value == null)
2985	>	return false;
2986	>	return internalReplace(key, null, value) != null;
2987	>	}
2988
2989	<	float lf = segments[0].loadFactor;
2990	<	int segs = segments.length;
2991	<	int cap = (int)(size() / lf);
2992	<	if (cap < segs) cap = segs;
2993	<	ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
2994	<	t.putAll(this);
2995	<	return t;
2989	>	/**
2990	>	* {@inheritDoc}
2991	>	*
2992	>	* @throws NullPointerException if any of the arguments are null
2993	>	*/
2994	>	public boolean replace(K key, V oldValue, V newValue) {
2995	>	if (key == null || oldValue == null || newValue == null)
2996	>	throw new NullPointerException();
2997	>	return internalReplace(key, newValue, oldValue) != null;
2998		}
2999
3000		/**
3001	<	* Returns a set view of the keys contained in this map.  The set is
857	<	* backed by the map, so changes to the map are reflected in the set, and
858	<	* vice-versa.  The set supports element removal, which removes the
859	<	* corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
860	<	* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
861	<	* <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
862	<	* <tt>addAll</tt> operations.
863	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
864	<	* will never throw {@link java.util.ConcurrentModificationException},
865	<	* and guarantees to traverse elements as they existed upon
866	<	* construction of the iterator, and may (but is not guaranteed to)
867	<	* reflect any modifications subsequent to construction.
3001	>	* {@inheritDoc}
3002		*
3003	<	* @return a set view of the keys contained in this map.
3003	>	* @return the previous value associated with the specified key,
3004	>	*         or {@code null} if there was no mapping for the key
3005	>	* @throws NullPointerException if the specified key or value is null
3006		*/
3007	<	public Set<K> keySet() {
3008	<	Set<K> ks = keySet;
3009	<	return (ks != null) ? ks : (keySet = new KeySet());
3007	>	@SuppressWarnings("unchecked") public V replace(K key, V value) {
3008	>	if (key == null || value == null)
3009	>	throw new NullPointerException();
3010	>	return (V)internalReplace(key, value, null);
3011		}
3012
3013	+	/**
3014	+	* Removes all of the mappings from this map.
3015	+	*/
3016	+	public void clear() {
3017	+	internalClear();
3018	+	}
3019
3020		/**
3021	<	* Returns a collection view of the values contained in this map.  The
3022	<	* collection is backed by the map, so changes to the map are reflected in
3023	<	* the collection, and vice-versa.  The collection supports element
881	<	* removal, which removes the corresponding mapping from this map, via the
882	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
883	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
884	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
885	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
886	<	* will never throw {@link java.util.ConcurrentModificationException},
887	<	* and guarantees to traverse elements as they existed upon
888	<	* construction of the iterator, and may (but is not guaranteed to)
889	<	* reflect any modifications subsequent to construction.
3021	>	* Returns a {@link Set} view of the keys contained in this map.
3022	>	* The set is backed by the map, so changes to the map are
3023	>	* reflected in the set, and vice-versa.
3024		*
3025	<	* @return a collection view of the values contained in this map.
3025	>	* @return the set view
3026		*/
3027	<	public Collection<V> values() {
3028	<	Collection<V> vs = values;
3029	<	return (vs != null) ? vs : (values = new Values());
3027	>	public KeySetView<K,V> keySet() {
3028	>	KeySetView<K,V> ks = keySet;
3029	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
3030		}
3031
3032	+	/**
3033	+	* Returns a {@link Set} view of the keys in this map, using the
3034	+	* given common mapped value for any additions (i.e., {@link
3035	+	* Collection#add} and {@link Collection#addAll}). This is of
3036	+	* course only appropriate if it is acceptable to use the same
3037	+	* value for all additions from this view.
3038	+	*
3039	+	* @param mappedValue the mapped value to use for any
3040	+	* additions.
3041	+	* @return the set view
3042	+	* @throws NullPointerException if the mappedValue is null
3043	+	*/
3044	+	public KeySetView<K,V> keySet(V mappedValue) {
3045	+	if (mappedValue == null)
3046	+	throw new NullPointerException();
3047	+	return new KeySetView<K,V>(this, mappedValue);
3048	+	}
3049	+
3050	+	/**
3051	+	* Returns a {@link Collection} view of the values contained in this map.
3052	+	* The collection is backed by the map, so changes to the map are
3053	+	* reflected in the collection, and vice-versa.
3054	+	*/
3055	+	public ValuesView<K,V> values() {
3056	+	ValuesView<K,V> vs = values;
3057	+	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
3058	+	}
3059
3060		/**
3061	<	* Returns a collection view of the mappings contained in this map.  Each
3062	<	* element in the returned collection is a <tt>Map.Entry</tt>.  The
3063	<	* collection is backed by the map, so changes to the map are reflected in
3064	<	* the collection, and vice-versa.  The collection supports element
3065	<	* removal, which removes the corresponding mapping from the map, via the
3066	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
3067	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
3068	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
3069	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
3070	<	* will never throw {@link java.util.ConcurrentModificationException},
3061	>	* Returns a {@link Set} view of the mappings contained in this map.
3062	>	* The set is backed by the map, so changes to the map are
3063	>	* reflected in the set, and vice-versa.  The set supports element
3064	>	* removal, which removes the corresponding mapping from the map,
3065	>	* via the {@code Iterator.remove}, {@code Set.remove},
3066	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
3067	>	* operations.  It does not support the {@code add} or
3068	>	* {@code addAll} operations.
3069	>	*
3070	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
3071	>	* that will never throw {@link ConcurrentModificationException},
3072		* and guarantees to traverse elements as they existed upon
3073		* construction of the iterator, and may (but is not guaranteed to)
3074		* reflect any modifications subsequent to construction.
913	–	*
914	–	* @return a collection view of the mappings contained in this map.
3075		*/
3076		public Set<Map.Entry<K,V>> entrySet() {
3077	<	Set<Map.Entry<K,V>> es = entrySet;
3078	<	return (es != null) ? es : (entrySet = (Set<Map.Entry<K,V>>) (Set) new EntrySet());
3077	>	EntrySetView<K,V> es = entrySet;
3078	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
3079		}
3080
921	–
3081		/**
3082		* Returns an enumeration of the keys in this table.
3083		*
3084	<	* @return  an enumeration of the keys in this table.
3085	<	* @see     #keySet
3084	>	* @return an enumeration of the keys in this table
3085	>	* @see #keySet()
3086		*/
3087		public Enumeration<K> keys() {
3088	<	return new KeyIterator();
3088	>	return new KeyIterator<K,V>(this);
3089		}
3090
3091		/**
3092		* Returns an enumeration of the values in this table.
934	–	* Use the Enumeration methods on the returned object to fetch the elements
935	–	* sequentially.
3093		*
3094	<	* @return  an enumeration of the values in this table.
3095	<	* @see     #values
3094	>	* @return an enumeration of the values in this table
3095	>	* @see #values()
3096		*/
3097		public Enumeration<V> elements() {
3098	<	return new ValueIterator();
3098	>	return new ValueIterator<K,V>(this);
3099		}
3100
3101	<	/* ---------------- Iterator Support -------------- */
3102	<
3103	<	private abstract class HashIterator {
3104	<	private int nextSegmentIndex;
3105	<	private int nextTableIndex;
3106	<	private HashEntry[] currentTable;
3107	<	private HashEntry<K, V> nextEntry;
3108	<	private HashEntry<K, V> lastReturned;
3101	>	/**
3102	>	* Returns a partitionable iterator of the keys in this map.
3103	>	*
3104	>	* @return a partitionable iterator of the keys in this map
3105	>	*/
3106	>	public Spliterator<K> keySpliterator() {
3107	>	return new KeyIterator<K,V>(this);
3108	>	}
3109
3110	<	private HashIterator() {
3111	<	nextSegmentIndex = segments.length - 1;
3112	<	nextTableIndex = -1;
3113	<	advance();
3114	<	}
3110	>	/**
3111	>	* Returns a partitionable iterator of the values in this map.
3112	>	*
3113	>	* @return a partitionable iterator of the values in this map
3114	>	*/
3115	>	public Spliterator<V> valueSpliterator() {
3116	>	return new ValueIterator<K,V>(this);
3117	>	}
3118
3119	<	public boolean hasMoreElements() { return hasNext(); }
3119	>	/**
3120	>	* Returns a partitionable iterator of the entries in this map.
3121	>	*
3122	>	* @return a partitionable iterator of the entries in this map
3123	>	*/
3124	>	public Spliterator<Map.Entry<K,V>> entrySpliterator() {
3125	>	return new EntryIterator<K,V>(this);
3126	>	}
3127
3128	<	private void advance() {
3129	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
3130	<	return;
3128	>	/**
3129	>	* Returns the hash code value for this {@link Map}, i.e.,
3130	>	* the sum of, for each key-value pair in the map,
3131	>	* {@code key.hashCode() ^ value.hashCode()}.
3132	>	*
3133	>	* @return the hash code value for this map
3134	>	*/
3135	>	public int hashCode() {
3136	>	int h = 0;
3137	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3138	>	Object v;
3139	>	while ((v = it.advance()) != null) {
3140	>	h += it.nextKey.hashCode() ^ v.hashCode();
3141	>	}
3142	>	return h;
3143	>	}
3144
3145	<	while (nextTableIndex >= 0) {
3146	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
3147	<	return;
3145	>	/**
3146	>	* Returns a string representation of this map.  The string
3147	>	* representation consists of a list of key-value mappings (in no
3148	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
3149	>	* mappings are separated by the characters {@code ", "} (comma
3150	>	* and space).  Each key-value mapping is rendered as the key
3151	>	* followed by an equals sign ("{@code =}") followed by the
3152	>	* associated value.
3153	>	*
3154	>	* @return a string representation of this map
3155	>	*/
3156	>	public String toString() {
3157	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3158	>	StringBuilder sb = new StringBuilder();
3159	>	sb.append('{');
3160	>	Object v;
3161	>	if ((v = it.advance()) != null) {
3162	>	for (;;) {
3163	>	Object k = it.nextKey;
3164	>	sb.append(k == this ? "(this Map)" : k);
3165	>	sb.append('=');
3166	>	sb.append(v == this ? "(this Map)" : v);
3167	>	if ((v = it.advance()) == null)
3168	>	break;
3169	>	sb.append(',').append(' ');
3170		}
3171	+	}
3172	+	return sb.append('}').toString();
3173	+	}
3174
3175	<	while (nextSegmentIndex >= 0) {
3176	<	Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
3177	<	if (seg.count != 0) {
3178	<	currentTable = seg.table;
3179	<	for (int j = currentTable.length - 1; j >= 0; --j) {
3180	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
3181	<	nextTableIndex = j - 1;
3182	<	return;
3183	<	}
3184	<	}
3185	<	}
3175	>	/**
3176	>	* Compares the specified object with this map for equality.
3177	>	* Returns {@code true} if the given object is a map with the same
3178	>	* mappings as this map.  This operation may return misleading
3179	>	* results if either map is concurrently modified during execution
3180	>	* of this method.
3181	>	*
3182	>	* @param o object to be compared for equality with this map
3183	>	* @return {@code true} if the specified object is equal to this map
3184	>	*/
3185	>	public boolean equals(Object o) {
3186	>	if (o != this) {
3187	>	if (!(o instanceof Map))
3188	>	return false;
3189	>	Map<?,?> m = (Map<?,?>) o;
3190	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3191	>	Object val;
3192	>	while ((val = it.advance()) != null) {
3193	>	Object v = m.get(it.nextKey);
3194	>	if (v == null || (v != val && !v.equals(val)))
3195	>	return false;
3196	>	}
3197	>	for (Map.Entry<?,?> e : m.entrySet()) {
3198	>	Object mk, mv, v;
3199	>	if ((mk = e.getKey()) == null ||
3200	>	(mv = e.getValue()) == null ||
3201	>	(v = internalGet(mk)) == null ||
3202	>	(mv != v && !mv.equals(v)))
3203	>	return false;
3204		}
3205		}
3206	+	return true;
3207	+	}
3208
3209	<	public boolean hasNext() { return nextEntry != null; }
3209	>	/* ----------------Iterators -------------- */
3210
3211	<	HashEntry<K,V> nextEntry() {
3212	<	if (nextEntry == null)
3211	>	@SuppressWarnings("serial") static final class KeyIterator<K,V> extends Traverser<K,V,Object>
3212	>	implements Spliterator<K>, Enumeration<K> {
3213	>	KeyIterator(ConcurrentHashMap<K, V> map) { super(map); }
3214	>	KeyIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
3215	>	super(map, it, -1);
3216	>	}
3217	>	public KeyIterator<K,V> split() {
3218	>	if (nextKey != null)
3219	>	throw new IllegalStateException();
3220	>	return new KeyIterator<K,V>(map, this);
3221	>	}
3222	>	@SuppressWarnings("unchecked") public final K next() {
3223	>	if (nextVal == null && advance() == null)
3224		throw new NoSuchElementException();
3225	<	lastReturned = nextEntry;
3226	<	advance();
3227	<	return lastReturned;
3225	>	Object k = nextKey;
3226	>	nextVal = null;
3227	>	return (K) k;
3228		}
3229
3230	<	public void remove() {
3231	<	if (lastReturned == null)
3230	>	public final K nextElement() { return next(); }
3231	>	}
3232	>
3233	>	@SuppressWarnings("serial") static final class ValueIterator<K,V> extends Traverser<K,V,Object>
3234	>	implements Spliterator<V>, Enumeration<V> {
3235	>	ValueIterator(ConcurrentHashMap<K, V> map) { super(map); }
3236	>	ValueIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
3237	>	super(map, it, -1);
3238	>	}
3239	>	public ValueIterator<K,V> split() {
3240	>	if (nextKey != null)
3241		throw new IllegalStateException();
3242	<	ConcurrentHashMap.this.remove(lastReturned.key);
3243	<	lastReturned = null;
3242	>	return new ValueIterator<K,V>(map, this);
3243	>	}
3244	>
3245	>	@SuppressWarnings("unchecked") public final V next() {
3246	>	Object v;
3247	>	if ((v = nextVal) == null && (v = advance()) == null)
3248	>	throw new NoSuchElementException();
3249	>	nextVal = null;
3250	>	return (V) v;
3251		}
3252	+
3253	+	public final V nextElement() { return next(); }
3254		}
3255
3256	<	private class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
3257	<	public K next() { return super.nextEntry().key; }
3258	<	public K nextElement() { return super.nextEntry().key; }
3256	>	@SuppressWarnings("serial") static final class EntryIterator<K,V> extends Traverser<K,V,Object>
3257	>	implements Spliterator<Map.Entry<K,V>> {
3258	>	EntryIterator(ConcurrentHashMap<K, V> map) { super(map); }
3259	>	EntryIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
3260	>	super(map, it, -1);
3261	>	}
3262	>	public EntryIterator<K,V> split() {
3263	>	if (nextKey != null)
3264	>	throw new IllegalStateException();
3265	>	return new EntryIterator<K,V>(map, this);
3266	>	}
3267	>
3268	>	@SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
3269	>	Object v;
3270	>	if ((v = nextVal) == null && (v = advance()) == null)
3271	>	throw new NoSuchElementException();
3272	>	Object k = nextKey;
3273	>	nextVal = null;
3274	>	return new MapEntry<K,V>((K)k, (V)v, map);
3275	>	}
3276	>	}
3277	>
3278	>	/**
3279	>	* Exported Entry for iterators
3280	>	*/
3281	>	static final class MapEntry<K,V> implements Map.Entry<K, V> {
3282	>	final K key; // non-null
3283	>	V val;       // non-null
3284	>	final ConcurrentHashMap<K, V> map;
3285	>	MapEntry(K key, V val, ConcurrentHashMap<K, V> map) {
3286	>	this.key = key;
3287	>	this.val = val;
3288	>	this.map = map;
3289	>	}
3290	>	public final K getKey()       { return key; }
3291	>	public final V getValue()     { return val; }
3292	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3293	>	public final String toString(){ return key + "=" + val; }
3294	>
3295	>	public final boolean equals(Object o) {
3296	>	Object k, v; Map.Entry<?,?> e;
3297	>	return ((o instanceof Map.Entry) &&
3298	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3299	>	(v = e.getValue()) != null &&
3300	>	(k == key || k.equals(key)) &&
3301	>	(v == val || v.equals(val)));
3302	>	}
3303	>
3304	>	/**
3305	>	* Sets our entry's value and writes through to the map. The
3306	>	* value to return is somewhat arbitrary here. Since we do not
3307	>	* necessarily track asynchronous changes, the most recent
3308	>	* "previous" value could be different from what we return (or
3309	>	* could even have been removed in which case the put will
3310	>	* re-establish). We do not and cannot guarantee more.
3311	>	*/
3312	>	public final V setValue(V value) {
3313	>	if (value == null) throw new NullPointerException();
3314	>	V v = val;
3315	>	val = value;
3316	>	map.put(key, value);
3317	>	return v;
3318	>	}
3319		}
3320
3321	<	private class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
3322	<	public V next() { return super.nextEntry().value; }
3323	<	public V nextElement() { return super.nextEntry().value; }
3321	>	/**
3322	>	* Returns exportable snapshot entry for the given key and value
3323	>	* when write-through can't or shouldn't be used.
3324	>	*/
3325	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3326	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
3327		}
3328
3329	<	private class EntryIterator extends HashIterator implements Iterator<Entry<K,V>> {
3330	<	public Map.Entry<K,V> next() { return super.nextEntry(); }
3329	>	/* ---------------- Serialization Support -------------- */
3330	>
3331	>	/**
3332	>	* Stripped-down version of helper class used in previous version,
3333	>	* declared for the sake of serialization compatibility
3334	>	*/
3335	>	static class Segment<K,V> implements Serializable {
3336	>	private static final long serialVersionUID = 2249069246763182397L;
3337	>	final float loadFactor;
3338	>	Segment(float lf) { this.loadFactor = lf; }
3339		}
3340
3341	<	private class KeySet extends AbstractSet<K> {
3342	<	public Iterator<K> iterator() {
3343	<	return new KeyIterator();
3344	<	}
3345	<	public int size() {
3346	<	return ConcurrentHashMap.this.size();
3341	>	/**
3342	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3343	>	* stream (i.e., serializes it).
3344	>	* @param s the stream
3345	>	* @serialData
3346	>	* the key (Object) and value (Object)
3347	>	* for each key-value mapping, followed by a null pair.
3348	>	* The key-value mappings are emitted in no particular order.
3349	>	*/
3350	>	@SuppressWarnings("unchecked") private void writeObject(java.io.ObjectOutputStream s)
3351	>	throws java.io.IOException {
3352	>	if (segments == null) { // for serialization compatibility
3353	>	segments = (Segment<K,V>[])
3354	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3355	>	for (int i = 0; i < segments.length; ++i)
3356	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3357		}
3358	<	public boolean contains(Object o) {
3359	<	return ConcurrentHashMap.this.containsKey(o);
3358	>	s.defaultWriteObject();
3359	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3360	>	Object v;
3361	>	while ((v = it.advance()) != null) {
3362	>	s.writeObject(it.nextKey);
3363	>	s.writeObject(v);
3364		}
3365	<	public boolean remove(Object o) {
3366	<	return ConcurrentHashMap.this.remove(o) != null;
3365	>	s.writeObject(null);
3366	>	s.writeObject(null);
3367	>	segments = null; // throw away
3368	>	}
3369	>
3370	>	/**
3371	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3372	>	* @param s the stream
3373	>	*/
3374	>	@SuppressWarnings("unchecked") private void readObject(java.io.ObjectInputStream s)
3375	>	throws java.io.IOException, ClassNotFoundException {
3376	>	s.defaultReadObject();
3377	>	this.segments = null; // unneeded
3378	>	// initialize transient final field
3379	>	UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
3380	>
3381	>	// Create all nodes, then place in table once size is known
3382	>	long size = 0L;
3383	>	Node p = null;
3384	>	for (;;) {
3385	>	K k = (K) s.readObject();
3386	>	V v = (V) s.readObject();
3387	>	if (k != null && v != null) {
3388	>	int h = spread(k.hashCode());
3389	>	p = new Node(h, k, v, p);
3390	>	++size;
3391	>	}
3392	>	else
3393	>	break;
3394		}
3395	<	public void clear() {
3396	<	ConcurrentHashMap.this.clear();
3395	>	if (p != null) {
3396	>	boolean init = false;
3397	>	int n;
3398	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3399	>	n = MAXIMUM_CAPACITY;
3400	>	else {
3401	>	int sz = (int)size;
3402	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3403	>	}
3404	>	int sc = sizeCtl;
3405	>	boolean collide = false;
3406	>	if (n > sc &&
3407	>	UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
3408	>	try {
3409	>	if (table == null) {
3410	>	init = true;
3411	>	Node[] tab = new Node[n];
3412	>	int mask = n - 1;
3413	>	while (p != null) {
3414	>	int j = p.hash & mask;
3415	>	Node next = p.next;
3416	>	Node q = p.next = tabAt(tab, j);
3417	>	setTabAt(tab, j, p);
3418	>	if (!collide && q != null && q.hash == p.hash)
3419	>	collide = true;
3420	>	p = next;
3421	>	}
3422	>	table = tab;
3423	>	counter.add(size);
3424	>	sc = n - (n >>> 2);
3425	>	}
3426	>	} finally {
3427	>	sizeCtl = sc;
3428	>	}
3429	>	if (collide) { // rescan and convert to TreeBins
3430	>	Node[] tab = table;
3431	>	for (int i = 0; i < tab.length; ++i) {
3432	>	int c = 0;
3433	>	for (Node e = tabAt(tab, i); e != null; e = e.next) {
3434	>	if (++c > TREE_THRESHOLD &&
3435	>	(e.key instanceof Comparable)) {
3436	>	replaceWithTreeBin(tab, i, e.key);
3437	>	break;
3438	>	}
3439	>	}
3440	>	}
3441	>	}
3442	>	}
3443	>	if (!init) { // Can only happen if unsafely published.
3444	>	while (p != null) {
3445	>	internalPut(p.key, p.val);
3446	>	p = p.next;
3447	>	}
3448	>	}
3449		}
3450		}
3451
3452	<	private class Values extends AbstractCollection<V> {
3453	<	public Iterator<V> iterator() {
3454	<	return new ValueIterator();
3452	>
3453	>	// -------------------------------------------------------
3454	>
3455	>	// Sams
3456	>	/** Interface describing a void action of one argument */
3457	>	public interface Action<A> { void apply(A a); }
3458	>	/** Interface describing a void action of two arguments */
3459	>	public interface BiAction<A,B> { void apply(A a, B b); }
3460	>	/** Interface describing a function of one argument */
3461	>	public interface Fun<A,T> { T apply(A a); }
3462	>	/** Interface describing a function of two arguments */
3463	>	public interface BiFun<A,B,T> { T apply(A a, B b); }
3464	>	/** Interface describing a function of no arguments */
3465	>	public interface Generator<T> { T apply(); }
3466	>	/** Interface describing a function mapping its argument to a double */
3467	>	public interface ObjectToDouble<A> { double apply(A a); }
3468	>	/** Interface describing a function mapping its argument to a long */
3469	>	public interface ObjectToLong<A> { long apply(A a); }
3470	>	/** Interface describing a function mapping its argument to an int */
3471	>	public interface ObjectToInt<A> {int apply(A a); }
3472	>	/** Interface describing a function mapping two arguments to a double */
3473	>	public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
3474	>	/** Interface describing a function mapping two arguments to a long */
3475	>	public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
3476	>	/** Interface describing a function mapping two arguments to an int */
3477	>	public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
3478	>	/** Interface describing a function mapping a double to a double */
3479	>	public interface DoubleToDouble { double apply(double a); }
3480	>	/** Interface describing a function mapping a long to a long */
3481	>	public interface LongToLong { long apply(long a); }
3482	>	/** Interface describing a function mapping an int to an int */
3483	>	public interface IntToInt { int apply(int a); }
3484	>	/** Interface describing a function mapping two doubles to a double */
3485	>	public interface DoubleByDoubleToDouble { double apply(double a, double b); }
3486	>	/** Interface describing a function mapping two longs to a long */
3487	>	public interface LongByLongToLong { long apply(long a, long b); }
3488	>	/** Interface describing a function mapping two ints to an int */
3489	>	public interface IntByIntToInt { int apply(int a, int b); }
3490	>
3491	>
3492	>	// -------------------------------------------------------
3493	>
3494	>	/**
3495	>	* Performs the given action for each (key, value).
3496	>	*
3497	>	* @param action the action
3498	>	*/
3499	>	public void forEach(BiAction<K,V> action) {
3500	>	ForkJoinTasks.forEach
3501	>	(this, action).invoke();
3502	>	}
3503	>
3504	>	/**
3505	>	* Performs the given action for each non-null transformation
3506	>	* of each (key, value).
3507	>	*
3508	>	* @param transformer a function returning the transformation
3509	>	* for an element, or null of there is no transformation (in
3510	>	* which case the action is not applied).
3511	>	* @param action the action
3512	>	*/
3513	>	public <U> void forEach(BiFun<? super K, ? super V, ? extends U> transformer,
3514	>	Action<U> action) {
3515	>	ForkJoinTasks.forEach
3516	>	(this, transformer, action).invoke();
3517	>	}
3518	>
3519	>	/**
3520	>	* Returns a non-null result from applying the given search
3521	>	* function on each (key, value), or null if none.  Upon
3522	>	* success, further element processing is suppressed and the
3523	>	* results of any other parallel invocations of the search
3524	>	* function are ignored.
3525	>	*
3526	>	* @param searchFunction a function returning a non-null
3527	>	* result on success, else null
3528	>	* @return a non-null result from applying the given search
3529	>	* function on each (key, value), or null if none
3530	>	*/
3531	>	public <U> U search(BiFun<? super K, ? super V, ? extends U> searchFunction) {
3532	>	return ForkJoinTasks.search
3533	>	(this, searchFunction).invoke();
3534	>	}
3535	>
3536	>	/**
3537	>	* Returns the result of accumulating the given transformation
3538	>	* of all (key, value) pairs using the given reducer to
3539	>	* combine values, or null if none.
3540	>	*
3541	>	* @param transformer a function returning the transformation
3542	>	* for an element, or null of there is no transformation (in
3543	>	* which case it is not combined).
3544	>	* @param reducer a commutative associative combining function
3545	>	* @return the result of accumulating the given transformation
3546	>	* of all (key, value) pairs
3547	>	*/
3548	>	public <U> U reduce(BiFun<? super K, ? super V, ? extends U> transformer,
3549	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3550	>	return ForkJoinTasks.reduce
3551	>	(this, transformer, reducer).invoke();
3552	>	}
3553	>
3554	>	/**
3555	>	* Returns the result of accumulating the given transformation
3556	>	* of all (key, value) pairs using the given reducer to
3557	>	* combine values, and the given basis as an identity value.
3558	>	*
3559	>	* @param transformer a function returning the transformation
3560	>	* for an element
3561	>	* @param basis the identity (initial default value) for the reduction
3562	>	* @param reducer a commutative associative combining function
3563	>	* @return the result of accumulating the given transformation
3564	>	* of all (key, value) pairs
3565	>	*/
3566	>	public double reduceToDouble(ObjectByObjectToDouble<? super K, ? super V> transformer,
3567	>	double basis,
3568	>	DoubleByDoubleToDouble reducer) {
3569	>	return ForkJoinTasks.reduceToDouble
3570	>	(this, transformer, basis, reducer).invoke();
3571	>	}
3572	>
3573	>	/**
3574	>	* Returns the result of accumulating the given transformation
3575	>	* of all (key, value) pairs using the given reducer to
3576	>	* combine values, and the given basis as an identity value.
3577	>	*
3578	>	* @param transformer a function returning the transformation
3579	>	* for an element
3580	>	* @param basis the identity (initial default value) for the reduction
3581	>	* @param reducer a commutative associative combining function
3582	>	* @return the result of accumulating the given transformation
3583	>	* of all (key, value) pairs
3584	>	*/
3585	>	public long reduceToLong(ObjectByObjectToLong<? super K, ? super V> transformer,
3586	>	long basis,
3587	>	LongByLongToLong reducer) {
3588	>	return ForkJoinTasks.reduceToLong
3589	>	(this, transformer, basis, reducer).invoke();
3590	>	}
3591	>
3592	>	/**
3593	>	* Returns the result of accumulating the given transformation
3594	>	* of all (key, value) pairs using the given reducer to
3595	>	* combine values, and the given basis as an identity value.
3596	>	*
3597	>	* @param transformer a function returning the transformation
3598	>	* for an element
3599	>	* @param basis the identity (initial default value) for the reduction
3600	>	* @param reducer a commutative associative combining function
3601	>	* @return the result of accumulating the given transformation
3602	>	* of all (key, value) pairs
3603	>	*/
3604	>	public int reduceToInt(ObjectByObjectToInt<? super K, ? super V> transformer,
3605	>	int basis,
3606	>	IntByIntToInt reducer) {
3607	>	return ForkJoinTasks.reduceToInt
3608	>	(this, transformer, basis, reducer).invoke();
3609	>	}
3610	>
3611	>	/**
3612	>	* Performs the given action for each key.
3613	>	*
3614	>	* @param action the action
3615	>	*/
3616	>	public void forEachKey(Action<K> action) {
3617	>	ForkJoinTasks.forEachKey
3618	>	(this, action).invoke();
3619	>	}
3620	>
3621	>	/**
3622	>	* Performs the given action for each non-null transformation
3623	>	* of each key.
3624	>	*
3625	>	* @param transformer a function returning the transformation
3626	>	* for an element, or null of there is no transformation (in
3627	>	* which case the action is not applied).
3628	>	* @param action the action
3629	>	*/
3630	>	public <U> void forEachKey(Fun<? super K, ? extends U> transformer,
3631	>	Action<U> action) {
3632	>	ForkJoinTasks.forEachKey
3633	>	(this, transformer, action).invoke();
3634	>	}
3635	>
3636	>	/**
3637	>	* Returns a non-null result from applying the given search
3638	>	* function on each key, or null if none. Upon success,
3639	>	* further element processing is suppressed and the results of
3640	>	* any other parallel invocations of the search function are
3641	>	* ignored.
3642	>	*
3643	>	* @param searchFunction a function returning a non-null
3644	>	* result on success, else null
3645	>	* @return a non-null result from applying the given search
3646	>	* function on each key, or null if none
3647	>	*/
3648	>	public <U> U searchKeys(Fun<? super K, ? extends U> searchFunction) {
3649	>	return ForkJoinTasks.searchKeys
3650	>	(this, searchFunction).invoke();
3651	>	}
3652	>
3653	>	/**
3654	>	* Returns the result of accumulating all keys using the given
3655	>	* reducer to combine values, or null if none.
3656	>	*
3657	>	* @param reducer a commutative associative combining function
3658	>	* @return the result of accumulating all keys using the given
3659	>	* reducer to combine values, or null if none
3660	>	*/
3661	>	public K reduceKeys(BiFun<? super K, ? super K, ? extends K> reducer) {
3662	>	return ForkJoinTasks.reduceKeys
3663	>	(this, reducer).invoke();
3664	>	}
3665	>
3666	>	/**
3667	>	* Returns the result of accumulating the given transformation
3668	>	* of all keys using the given reducer to combine values, or
3669	>	* null if none.
3670	>	*
3671	>	* @param transformer a function returning the transformation
3672	>	* for an element, or null of there is no transformation (in
3673	>	* which case it is not combined).
3674	>	* @param reducer a commutative associative combining function
3675	>	* @return the result of accumulating the given transformation
3676	>	* of all keys
3677	>	*/
3678	>	public <U> U reduceKeys(Fun<? super K, ? extends U> transformer,
3679	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3680	>	return ForkJoinTasks.reduceKeys
3681	>	(this, transformer, reducer).invoke();
3682	>	}
3683	>
3684	>	/**
3685	>	* Returns the result of accumulating the given transformation
3686	>	* of all keys using the given reducer to combine values, and
3687	>	* the given basis as an identity value.
3688	>	*
3689	>	* @param transformer a function returning the transformation
3690	>	* for an element
3691	>	* @param basis the identity (initial default value) for the reduction
3692	>	* @param reducer a commutative associative combining function
3693	>	* @return  the result of accumulating the given transformation
3694	>	* of all keys
3695	>	*/
3696	>	public double reduceKeysToDouble(ObjectToDouble<? super K> transformer,
3697	>	double basis,
3698	>	DoubleByDoubleToDouble reducer) {
3699	>	return ForkJoinTasks.reduceKeysToDouble
3700	>	(this, transformer, basis, reducer).invoke();
3701	>	}
3702	>
3703	>	/**
3704	>	* Returns the result of accumulating the given transformation
3705	>	* of all keys using the given reducer to combine values, and
3706	>	* the given basis as an identity value.
3707	>	*
3708	>	* @param transformer a function returning the transformation
3709	>	* for an element
3710	>	* @param basis the identity (initial default value) for the reduction
3711	>	* @param reducer a commutative associative combining function
3712	>	* @return the result of accumulating the given transformation
3713	>	* of all keys
3714	>	*/
3715	>	public long reduceKeysToLong(ObjectToLong<? super K> transformer,
3716	>	long basis,
3717	>	LongByLongToLong reducer) {
3718	>	return ForkJoinTasks.reduceKeysToLong
3719	>	(this, transformer, basis, reducer).invoke();
3720	>	}
3721	>
3722	>	/**
3723	>	* Returns the result of accumulating the given transformation
3724	>	* of all keys using the given reducer to combine values, and
3725	>	* the given basis as an identity value.
3726	>	*
3727	>	* @param transformer a function returning the transformation
3728	>	* for an element
3729	>	* @param basis the identity (initial default value) for the reduction
3730	>	* @param reducer a commutative associative combining function
3731	>	* @return the result of accumulating the given transformation
3732	>	* of all keys
3733	>	*/
3734	>	public int reduceKeysToInt(ObjectToInt<? super K> transformer,
3735	>	int basis,
3736	>	IntByIntToInt reducer) {
3737	>	return ForkJoinTasks.reduceKeysToInt
3738	>	(this, transformer, basis, reducer).invoke();
3739	>	}
3740	>
3741	>	/**
3742	>	* Performs the given action for each value.
3743	>	*
3744	>	* @param action the action
3745	>	*/
3746	>	public void forEachValue(Action<V> action) {
3747	>	ForkJoinTasks.forEachValue
3748	>	(this, action).invoke();
3749	>	}
3750	>
3751	>	/**
3752	>	* Performs the given action for each non-null transformation
3753	>	* of each value.
3754	>	*
3755	>	* @param transformer a function returning the transformation
3756	>	* for an element, or null of there is no transformation (in
3757	>	* which case the action is not applied).
3758	>	*/
3759	>	public <U> void forEachValue(Fun<? super V, ? extends U> transformer,
3760	>	Action<U> action) {
3761	>	ForkJoinTasks.forEachValue
3762	>	(this, transformer, action).invoke();
3763	>	}
3764	>
3765	>	/**
3766	>	* Returns a non-null result from applying the given search
3767	>	* function on each value, or null if none.  Upon success,
3768	>	* further element processing is suppressed and the results of
3769	>	* any other parallel invocations of the search function are
3770	>	* ignored.
3771	>	*
3772	>	* @param searchFunction a function returning a non-null
3773	>	* result on success, else null
3774	>	* @return a non-null result from applying the given search
3775	>	* function on each value, or null if none
3776	>	*
3777	>	*/
3778	>	public <U> U searchValues(Fun<? super V, ? extends U> searchFunction) {
3779	>	return ForkJoinTasks.searchValues
3780	>	(this, searchFunction).invoke();
3781	>	}
3782	>
3783	>	/**
3784	>	* Returns the result of accumulating all values using the
3785	>	* given reducer to combine values, or null if none.
3786	>	*
3787	>	* @param reducer a commutative associative combining function
3788	>	* @return  the result of accumulating all values
3789	>	*/
3790	>	public V reduceValues(BiFun<? super V, ? super V, ? extends V> reducer) {
3791	>	return ForkJoinTasks.reduceValues
3792	>	(this, reducer).invoke();
3793	>	}
3794	>
3795	>	/**
3796	>	* Returns the result of accumulating the given transformation
3797	>	* of all values using the given reducer to combine values, or
3798	>	* null if none.
3799	>	*
3800	>	* @param transformer a function returning the transformation
3801	>	* for an element, or null of there is no transformation (in
3802	>	* which case it is not combined).
3803	>	* @param reducer a commutative associative combining function
3804	>	* @return the result of accumulating the given transformation
3805	>	* of all values
3806	>	*/
3807	>	public <U> U reduceValues(Fun<? super V, ? extends U> transformer,
3808	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3809	>	return ForkJoinTasks.reduceValues
3810	>	(this, transformer, reducer).invoke();
3811	>	}
3812	>
3813	>	/**
3814	>	* Returns the result of accumulating the given transformation
3815	>	* of all values using the given reducer to combine values,
3816	>	* and the given basis as an identity value.
3817	>	*
3818	>	* @param transformer a function returning the transformation
3819	>	* for an element
3820	>	* @param basis the identity (initial default value) for the reduction
3821	>	* @param reducer a commutative associative combining function
3822	>	* @return the result of accumulating the given transformation
3823	>	* of all values
3824	>	*/
3825	>	public double reduceValuesToDouble(ObjectToDouble<? super V> transformer,
3826	>	double basis,
3827	>	DoubleByDoubleToDouble reducer) {
3828	>	return ForkJoinTasks.reduceValuesToDouble
3829	>	(this, transformer, basis, reducer).invoke();
3830	>	}
3831	>
3832	>	/**
3833	>	* Returns the result of accumulating the given transformation
3834	>	* of all values using the given reducer to combine values,
3835	>	* and the given basis as an identity value.
3836	>	*
3837	>	* @param transformer a function returning the transformation
3838	>	* for an element
3839	>	* @param basis the identity (initial default value) for the reduction
3840	>	* @param reducer a commutative associative combining function
3841	>	* @return the result of accumulating the given transformation
3842	>	* of all values
3843	>	*/
3844	>	public long reduceValuesToLong(ObjectToLong<? super V> transformer,
3845	>	long basis,
3846	>	LongByLongToLong reducer) {
3847	>	return ForkJoinTasks.reduceValuesToLong
3848	>	(this, transformer, basis, reducer).invoke();
3849	>	}
3850	>
3851	>	/**
3852	>	* Returns the result of accumulating the given transformation
3853	>	* of all values using the given reducer to combine values,
3854	>	* and the given basis as an identity value.
3855	>	*
3856	>	* @param transformer a function returning the transformation
3857	>	* for an element
3858	>	* @param basis the identity (initial default value) for the reduction
3859	>	* @param reducer a commutative associative combining function
3860	>	* @return the result of accumulating the given transformation
3861	>	* of all values
3862	>	*/
3863	>	public int reduceValuesToInt(ObjectToInt<? super V> transformer,
3864	>	int basis,
3865	>	IntByIntToInt reducer) {
3866	>	return ForkJoinTasks.reduceValuesToInt
3867	>	(this, transformer, basis, reducer).invoke();
3868	>	}
3869	>
3870	>	/**
3871	>	* Performs the given action for each entry.
3872	>	*
3873	>	* @param action the action
3874	>	*/
3875	>	public void forEachEntry(Action<Map.Entry<K,V>> action) {
3876	>	ForkJoinTasks.forEachEntry
3877	>	(this, action).invoke();
3878	>	}
3879	>
3880	>	/**
3881	>	* Performs the given action for each non-null transformation
3882	>	* of each entry.
3883	>	*
3884	>	* @param transformer a function returning the transformation
3885	>	* for an element, or null of there is no transformation (in
3886	>	* which case the action is not applied).
3887	>	* @param action the action
3888	>	*/
3889	>	public <U> void forEachEntry(Fun<Map.Entry<K,V>, ? extends U> transformer,
3890	>	Action<U> action) {
3891	>	ForkJoinTasks.forEachEntry
3892	>	(this, transformer, action).invoke();
3893	>	}
3894	>
3895	>	/**
3896	>	* Returns a non-null result from applying the given search
3897	>	* function on each entry, or null if none.  Upon success,
3898	>	* further element processing is suppressed and the results of
3899	>	* any other parallel invocations of the search function are
3900	>	* ignored.
3901	>	*
3902	>	* @param searchFunction a function returning a non-null
3903	>	* result on success, else null
3904	>	* @return a non-null result from applying the given search
3905	>	* function on each entry, or null if none
3906	>	*/
3907	>	public <U> U searchEntries(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
3908	>	return ForkJoinTasks.searchEntries
3909	>	(this, searchFunction).invoke();
3910	>	}
3911	>
3912	>	/**
3913	>	* Returns the result of accumulating all entries using the
3914	>	* given reducer to combine values, or null if none.
3915	>	*
3916	>	* @param reducer a commutative associative combining function
3917	>	* @return the result of accumulating all entries
3918	>	*/
3919	>	public Map.Entry<K,V> reduceEntries(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3920	>	return ForkJoinTasks.reduceEntries
3921	>	(this, reducer).invoke();
3922	>	}
3923	>
3924	>	/**
3925	>	* Returns the result of accumulating the given transformation
3926	>	* of all entries using the given reducer to combine values,
3927	>	* or null if none.
3928	>	*
3929	>	* @param transformer a function returning the transformation
3930	>	* for an element, or null of there is no transformation (in
3931	>	* which case it is not combined).
3932	>	* @param reducer a commutative associative combining function
3933	>	* @return the result of accumulating the given transformation
3934	>	* of all entries
3935	>	*/
3936	>	public <U> U reduceEntries(Fun<Map.Entry<K,V>, ? extends U> transformer,
3937	>	BiFun<? super U, ? super U, ? extends U> reducer) {
3938	>	return ForkJoinTasks.reduceEntries
3939	>	(this, transformer, reducer).invoke();
3940	>	}
3941	>
3942	>	/**
3943	>	* Returns the result of accumulating the given transformation
3944	>	* of all entries using the given reducer to combine values,
3945	>	* and the given basis as an identity value.
3946	>	*
3947	>	* @param transformer a function returning the transformation
3948	>	* for an element
3949	>	* @param basis the identity (initial default value) for the reduction
3950	>	* @param reducer a commutative associative combining function
3951	>	* @return the result of accumulating the given transformation
3952	>	* of all entries
3953	>	*/
3954	>	public double reduceEntriesToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
3955	>	double basis,
3956	>	DoubleByDoubleToDouble reducer) {
3957	>	return ForkJoinTasks.reduceEntriesToDouble
3958	>	(this, transformer, basis, reducer).invoke();
3959	>	}
3960	>
3961	>	/**
3962	>	* Returns the result of accumulating the given transformation
3963	>	* of all entries using the given reducer to combine values,
3964	>	* and the given basis as an identity value.
3965	>	*
3966	>	* @param transformer a function returning the transformation
3967	>	* for an element
3968	>	* @param basis the identity (initial default value) for the reduction
3969	>	* @param reducer a commutative associative combining function
3970	>	* @return  the result of accumulating the given transformation
3971	>	* of all entries
3972	>	*/
3973	>	public long reduceEntriesToLong(ObjectToLong<Map.Entry<K,V>> transformer,
3974	>	long basis,
3975	>	LongByLongToLong reducer) {
3976	>	return ForkJoinTasks.reduceEntriesToLong
3977	>	(this, transformer, basis, reducer).invoke();
3978	>	}
3979	>
3980	>	/**
3981	>	* Returns the result of accumulating the given transformation
3982	>	* of all entries using the given reducer to combine values,
3983	>	* and the given basis as an identity value.
3984	>	*
3985	>	* @param transformer a function returning the transformation
3986	>	* for an element
3987	>	* @param basis the identity (initial default value) for the reduction
3988	>	* @param reducer a commutative associative combining function
3989	>	* @return the result of accumulating the given transformation
3990	>	* of all entries
3991	>	*/
3992	>	public int reduceEntriesToInt(ObjectToInt<Map.Entry<K,V>> transformer,
3993	>	int basis,
3994	>	IntByIntToInt reducer) {
3995	>	return ForkJoinTasks.reduceEntriesToInt
3996	>	(this, transformer, basis, reducer).invoke();
3997	>	}
3998	>
3999	>	/* ----------------Views -------------- */
4000	>
4001	>	/**
4002	>	* Base class for views.
4003	>	*/
4004	>	static abstract class CHMView<K, V> {
4005	>	final ConcurrentHashMap<K, V> map;
4006	>	CHMView(ConcurrentHashMap<K, V> map)  { this.map = map; }
4007	>
4008	>	/**
4009	>	* Returns the map backing this view.
4010	>	*
4011	>	* @return the map backing this view
4012	>	*/
4013	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4014	>
4015	>	public final int size()                 { return map.size(); }
4016	>	public final boolean isEmpty()          { return map.isEmpty(); }
4017	>	public final void clear()               { map.clear(); }
4018	>
4019	>	// implementations below rely on concrete classes supplying these
4020	>	abstract public Iterator<?> iterator();
4021	>	abstract public boolean contains(Object o);
4022	>	abstract public boolean remove(Object o);
4023	>
4024	>	private static final String oomeMsg = "Required array size too large";
4025	>
4026	>	public final Object[] toArray() {
4027	>	long sz = map.mappingCount();
4028	>	if (sz > (long)(MAX_ARRAY_SIZE))
4029	>	throw new OutOfMemoryError(oomeMsg);
4030	>	int n = (int)sz;
4031	>	Object[] r = new Object[n];
4032	>	int i = 0;
4033	>	Iterator<?> it = iterator();
4034	>	while (it.hasNext()) {
4035	>	if (i == n) {
4036	>	if (n >= MAX_ARRAY_SIZE)
4037	>	throw new OutOfMemoryError(oomeMsg);
4038	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4039	>	n = MAX_ARRAY_SIZE;
4040	>	else
4041	>	n += (n >>> 1) + 1;
4042	>	r = Arrays.copyOf(r, n);
4043	>	}
4044	>	r[i++] = it.next();
4045	>	}
4046	>	return (i == n) ? r : Arrays.copyOf(r, i);
4047		}
4048	<	public int size() {
4049	<	return ConcurrentHashMap.this.size();
4048	>
4049	>	@SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4050	>	long sz = map.mappingCount();
4051	>	if (sz > (long)(MAX_ARRAY_SIZE))
4052	>	throw new OutOfMemoryError(oomeMsg);
4053	>	int m = (int)sz;
4054	>	T[] r = (a.length >= m) ? a :
4055	>	(T[])java.lang.reflect.Array
4056	>	.newInstance(a.getClass().getComponentType(), m);
4057	>	int n = r.length;
4058	>	int i = 0;
4059	>	Iterator<?> it = iterator();
4060	>	while (it.hasNext()) {
4061	>	if (i == n) {
4062	>	if (n >= MAX_ARRAY_SIZE)
4063	>	throw new OutOfMemoryError(oomeMsg);
4064	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4065	>	n = MAX_ARRAY_SIZE;
4066	>	else
4067	>	n += (n >>> 1) + 1;
4068	>	r = Arrays.copyOf(r, n);
4069	>	}
4070	>	r[i++] = (T)it.next();
4071	>	}
4072	>	if (a == r && i < n) {
4073	>	r[i] = null; // null-terminate
4074	>	return r;
4075	>	}
4076	>	return (i == n) ? r : Arrays.copyOf(r, i);
4077		}
4078	<	public boolean contains(Object o) {
4079	<	return ConcurrentHashMap.this.containsValue(o);
4078	>
4079	>	public final int hashCode() {
4080	>	int h = 0;
4081	>	for (Iterator<?> it = iterator(); it.hasNext();)
4082	>	h += it.next().hashCode();
4083	>	return h;
4084		}
4085	<	public void clear() {
4086	<	ConcurrentHashMap.this.clear();
4085	>
4086	>	public final String toString() {
4087	>	StringBuilder sb = new StringBuilder();
4088	>	sb.append('[');
4089	>	Iterator<?> it = iterator();
4090	>	if (it.hasNext()) {
4091	>	for (;;) {
4092	>	Object e = it.next();
4093	>	sb.append(e == this ? "(this Collection)" : e);
4094	>	if (!it.hasNext())
4095	>	break;
4096	>	sb.append(',').append(' ');
4097	>	}
4098	>	}
4099	>	return sb.append(']').toString();
4100		}
4101	+
4102	+	public final boolean containsAll(Collection<?> c) {
4103	+	if (c != this) {
4104	+	for (Iterator<?> it = c.iterator(); it.hasNext();) {
4105	+	Object e = it.next();
4106	+	if (e == null || !contains(e))
4107	+	return false;
4108	+	}
4109	+	}
4110	+	return true;
4111	+	}
4112	+
4113	+	public final boolean removeAll(Collection<?> c) {
4114	+	boolean modified = false;
4115	+	for (Iterator<?> it = iterator(); it.hasNext();) {
4116	+	if (c.contains(it.next())) {
4117	+	it.remove();
4118	+	modified = true;
4119	+	}
4120	+	}
4121	+	return modified;
4122	+	}
4123	+
4124	+	public final boolean retainAll(Collection<?> c) {
4125	+	boolean modified = false;
4126	+	for (Iterator<?> it = iterator(); it.hasNext();) {
4127	+	if (!c.contains(it.next())) {
4128	+	it.remove();
4129	+	modified = true;
4130	+	}
4131	+	}
4132	+	return modified;
4133	+	}
4134	+
4135		}
4136
4137	<	private class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4138	<	public Iterator<Map.Entry<K,V>> iterator() {
4139	<	return new EntryIterator();
4137	>	/**
4138	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4139	>	* which additions may optionally be enabled by mapping to a
4140	>	* common value.  This class cannot be directly instantiated. See
4141	>	* {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4142	>	* {@link #newKeySet(int)}.
4143	>	*/
4144	>	public static class KeySetView<K,V> extends CHMView<K,V> implements Set<K>, java.io.Serializable {
4145	>	private static final long serialVersionUID = 7249069246763182397L;
4146	>	private final V value;
4147	>	KeySetView(ConcurrentHashMap<K, V> map, V value) {  // non-public
4148	>	super(map);
4149	>	this.value = value;
4150		}
4151	<	public boolean contains(Object o) {
4152	<	if (!(o instanceof Map.Entry))
4153	<	return false;
4154	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4155	<	V v = ConcurrentHashMap.this.get(e.getKey());
4156	<	return v != null && v.equals(e.getValue());
4151	>
4152	>	/**
4153	>	* Returns the default mapped value for additions,
4154	>	* or {@code null} if additions are not supported.
4155	>	*
4156	>	* @return the default mapped value for additions, or {@code null}
4157	>	* if not supported.
4158	>	*/
4159	>	public V getMappedValue() { return value; }
4160	>
4161	>	// implement Set API
4162	>
4163	>	public boolean contains(Object o) { return map.containsKey(o); }
4164	>	public boolean remove(Object o)   { return map.remove(o) != null; }
4165	>
4166	>	/**
4167	>	* Returns a "weakly consistent" iterator that will never
4168	>	* throw {@link ConcurrentModificationException}, and
4169	>	* guarantees to traverse elements as they existed upon
4170	>	* construction of the iterator, and may (but is not
4171	>	* guaranteed to) reflect any modifications subsequent to
4172	>	* construction.
4173	>	*
4174	>	* @return an iterator over the keys of this map
4175	>	*/
4176	>	public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4177	>	public boolean add(K e) {
4178	>	V v;
4179	>	if ((v = value) == null)
4180	>	throw new UnsupportedOperationException();
4181	>	if (e == null)
4182	>	throw new NullPointerException();
4183	>	return map.internalPutIfAbsent(e, v) == null;
4184		}
4185	<	public boolean remove(Object o) {
4186	<	if (!(o instanceof Map.Entry))
4187	<	return false;
4188	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4189	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4185	>	public boolean addAll(Collection<? extends K> c) {
4186	>	boolean added = false;
4187	>	V v;
4188	>	if ((v = value) == null)
4189	>	throw new UnsupportedOperationException();
4190	>	for (K e : c) {
4191	>	if (e == null)
4192	>	throw new NullPointerException();
4193	>	if (map.internalPutIfAbsent(e, v) == null)
4194	>	added = true;
4195	>	}
4196	>	return added;
4197		}
4198	<	public int size() {
4199	<	return ConcurrentHashMap.this.size();
4198	>	public boolean equals(Object o) {
4199	>	Set<?> c;
4200	>	return ((o instanceof Set) &&
4201	>	((c = (Set<?>)o) == this ||
4202	>	(containsAll(c) && c.containsAll(this))));
4203		}
4204	<	public void clear() {
4205	<	ConcurrentHashMap.this.clear();
4204	>
4205	>	/**
4206	>	* Performs the given action for each key.
4207	>	*
4208	>	* @param action the action
4209	>	*/
4210	>	public void forEach(Action<K> action) {
4211	>	ForkJoinTasks.forEachKey
4212	>	(map, action).invoke();
4213	>	}
4214	>
4215	>	/**
4216	>	* Performs the given action for each non-null transformation
4217	>	* of each key.
4218	>	*
4219	>	* @param transformer a function returning the transformation
4220	>	* for an element, or null of there is no transformation (in
4221	>	* which case the action is not applied).
4222	>	* @param action the action
4223	>	*/
4224	>	public <U> void forEach(Fun<? super K, ? extends U> transformer,
4225	>	Action<U> action) {
4226	>	ForkJoinTasks.forEachKey
4227	>	(map, transformer, action).invoke();
4228	>	}
4229	>
4230	>	/**
4231	>	* Returns a non-null result from applying the given search
4232	>	* function on each key, or null if none. Upon success,
4233	>	* further element processing is suppressed and the results of
4234	>	* any other parallel invocations of the search function are
4235	>	* ignored.
4236	>	*
4237	>	* @param searchFunction a function returning a non-null
4238	>	* result on success, else null
4239	>	* @return a non-null result from applying the given search
4240	>	* function on each key, or null if none
4241	>	*/
4242	>	public <U> U search(Fun<? super K, ? extends U> searchFunction) {
4243	>	return ForkJoinTasks.searchKeys
4244	>	(map, searchFunction).invoke();
4245	>	}
4246	>
4247	>	/**
4248	>	* Returns the result of accumulating all keys using the given
4249	>	* reducer to combine values, or null if none.
4250	>	*
4251	>	* @param reducer a commutative associative combining function
4252	>	* @return the result of accumulating all keys using the given
4253	>	* reducer to combine values, or null if none
4254	>	*/
4255	>	public K reduce(BiFun<? super K, ? super K, ? extends K> reducer) {
4256	>	return ForkJoinTasks.reduceKeys
4257	>	(map, reducer).invoke();
4258	>	}
4259	>
4260	>	/**
4261	>	* Returns the result of accumulating the given transformation
4262	>	* of all keys using the given reducer to combine values, and
4263	>	* the given basis as an identity value.
4264	>	*
4265	>	* @param transformer a function returning the transformation
4266	>	* for an element
4267	>	* @param basis the identity (initial default value) for the reduction
4268	>	* @param reducer a commutative associative combining function
4269	>	* @return  the result of accumulating the given transformation
4270	>	* of all keys
4271	>	*/
4272	>	public double reduceToDouble(ObjectToDouble<? super K> transformer,
4273	>	double basis,
4274	>	DoubleByDoubleToDouble reducer) {
4275	>	return ForkJoinTasks.reduceKeysToDouble
4276	>	(map, transformer, basis, reducer).invoke();
4277		}
1072	–	}
4278
4279	<	/* ---------------- Serialization Support -------------- */
4279	>
4280	>	/**
4281	>	* Returns the result of accumulating the given transformation
4282	>	* of all keys using the given reducer to combine values, and
4283	>	* the given basis as an identity value.
4284	>	*
4285	>	* @param transformer a function returning the transformation
4286	>	* for an element
4287	>	* @param basis the identity (initial default value) for the reduction
4288	>	* @param reducer a commutative associative combining function
4289	>	* @return the result of accumulating the given transformation
4290	>	* of all keys
4291	>	*/
4292	>	public long reduceToLong(ObjectToLong<? super K> transformer,
4293	>	long basis,
4294	>	LongByLongToLong reducer) {
4295	>	return ForkJoinTasks.reduceKeysToLong
4296	>	(map, transformer, basis, reducer).invoke();
4297	>	}
4298	>
4299	>	/**
4300	>	* Returns the result of accumulating the given transformation
4301	>	* of all keys using the given reducer to combine values, and
4302	>	* the given basis as an identity value.
4303	>	*
4304	>	* @param transformer a function returning the transformation
4305	>	* for an element
4306	>	* @param basis the identity (initial default value) for the reduction
4307	>	* @param reducer a commutative associative combining function
4308	>	* @return the result of accumulating the given transformation
4309	>	* of all keys
4310	>	*/
4311	>	public int reduceToInt(ObjectToInt<? super K> transformer,
4312	>	int basis,
4313	>	IntByIntToInt reducer) {
4314	>	return ForkJoinTasks.reduceKeysToInt
4315	>	(map, transformer, basis, reducer).invoke();
4316	>	}
4317	>
4318	>	}
4319
4320		/**
4321	<	* Save the state of the <tt>ConcurrentHashMap</tt>
4322	<	* instance to a stream (i.e.,
4323	<	* serialize it).
4324	<	* @param s the stream
4325	<	* @serialData
4326	<	* the key (Object) and value (Object)
4327	<	* for each key-value mapping, followed by a null pair.
4328	<	* The key-value mappings are emitted in no particular order.
4321	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4322	>	* values, in which additions are disabled. This class cannot be
4323	>	* directly instantiated. See {@link #values},
4324	>	*
4325	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4326	>	* that will never throw {@link ConcurrentModificationException},
4327	>	* and guarantees to traverse elements as they existed upon
4328	>	* construction of the iterator, and may (but is not guaranteed to)
4329	>	* reflect any modifications subsequent to construction.
4330		*/
4331	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4332	<	s.defaultWriteObject();
4333	<
4334	<	for (int k = 0; k < segments.length; ++k) {
4335	<	Segment<K,V> seg = (Segment<K,V>)segments[k];
4336	<	seg.lock();
4337	<	try {
4338	<	HashEntry[] tab = seg.table;
4339	<	for (int i = 0; i < tab.length; ++i) {
4340	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
4341	<	s.writeObject(e.key);
1097	<	s.writeObject(e.value);
4331	>	public static final class ValuesView<K,V> extends CHMView<K,V>
4332	>	implements Collection<V> {
4333	>	ValuesView(ConcurrentHashMap<K, V> map)   { super(map); }
4334	>	public final boolean contains(Object o) { return map.containsValue(o); }
4335	>	public final boolean remove(Object o) {
4336	>	if (o != null) {
4337	>	Iterator<V> it = new ValueIterator<K,V>(map);
4338	>	while (it.hasNext()) {
4339	>	if (o.equals(it.next())) {
4340	>	it.remove();
4341	>	return true;
4342		}
4343		}
1100	–	} finally {
1101	–	seg.unlock();
4344		}
4345	+	return false;
4346		}
4347	<	s.writeObject(null);
4348	<	s.writeObject(null);
4347	>
4348	>	/**
4349	>	* Returns a "weakly consistent" iterator that will never
4350	>	* throw {@link ConcurrentModificationException}, and
4351	>	* guarantees to traverse elements as they existed upon
4352	>	* construction of the iterator, and may (but is not
4353	>	* guaranteed to) reflect any modifications subsequent to
4354	>	* construction.
4355	>	*
4356	>	* @return an iterator over the values of this map
4357	>	*/
4358	>	public final Iterator<V> iterator() {
4359	>	return new ValueIterator<K,V>(map);
4360	>	}
4361	>	public final boolean add(V e) {
4362	>	throw new UnsupportedOperationException();
4363	>	}
4364	>	public final boolean addAll(Collection<? extends V> c) {
4365	>	throw new UnsupportedOperationException();
4366	>	}
4367	>
4368	>	/**
4369	>	* Performs the given action for each value.
4370	>	*
4371	>	* @param action the action
4372	>	*/
4373	>	public void forEach(Action<V> action) {
4374	>	ForkJoinTasks.forEachValue
4375	>	(map, action).invoke();
4376	>	}
4377	>
4378	>	/**
4379	>	* Performs the given action for each non-null transformation
4380	>	* of each value.
4381	>	*
4382	>	* @param transformer a function returning the transformation
4383	>	* for an element, or null of there is no transformation (in
4384	>	* which case the action is not applied).
4385	>	*/
4386	>	public <U> void forEach(Fun<? super V, ? extends U> transformer,
4387	>	Action<U> action) {
4388	>	ForkJoinTasks.forEachValue
4389	>	(map, transformer, action).invoke();
4390	>	}
4391	>
4392	>	/**
4393	>	* Returns a non-null result from applying the given search
4394	>	* function on each value, or null if none.  Upon success,
4395	>	* further element processing is suppressed and the results of
4396	>	* any other parallel invocations of the search function are
4397	>	* ignored.
4398	>	*
4399	>	* @param searchFunction a function returning a non-null
4400	>	* result on success, else null
4401	>	* @return a non-null result from applying the given search
4402	>	* function on each value, or null if none
4403	>	*
4404	>	*/
4405	>	public <U> U search(Fun<? super V, ? extends U> searchFunction) {
4406	>	return ForkJoinTasks.searchValues
4407	>	(map, searchFunction).invoke();
4408	>	}
4409	>
4410	>	/**
4411	>	* Returns the result of accumulating all values using the
4412	>	* given reducer to combine values, or null if none.
4413	>	*
4414	>	* @param reducer a commutative associative combining function
4415	>	* @return  the result of accumulating all values
4416	>	*/
4417	>	public V reduce(BiFun<? super V, ? super V, ? extends V> reducer) {
4418	>	return ForkJoinTasks.reduceValues
4419	>	(map, reducer).invoke();
4420	>	}
4421	>
4422	>	/**
4423	>	* Returns the result of accumulating the given transformation
4424	>	* of all values using the given reducer to combine values, or
4425	>	* null if none.
4426	>	*
4427	>	* @param transformer a function returning the transformation
4428	>	* for an element, or null of there is no transformation (in
4429	>	* which case it is not combined).
4430	>	* @param reducer a commutative associative combining function
4431	>	* @return the result of accumulating the given transformation
4432	>	* of all values
4433	>	*/
4434	>	public <U> U reduce(Fun<? super V, ? extends U> transformer,
4435	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4436	>	return ForkJoinTasks.reduceValues
4437	>	(map, transformer, reducer).invoke();
4438	>	}
4439	>
4440	>	/**
4441	>	* Returns the result of accumulating the given transformation
4442	>	* of all values using the given reducer to combine values,
4443	>	* and the given basis as an identity value.
4444	>	*
4445	>	* @param transformer a function returning the transformation
4446	>	* for an element
4447	>	* @param basis the identity (initial default value) for the reduction
4448	>	* @param reducer a commutative associative combining function
4449	>	* @return the result of accumulating the given transformation
4450	>	* of all values
4451	>	*/
4452	>	public double reduceToDouble(ObjectToDouble<? super V> transformer,
4453	>	double basis,
4454	>	DoubleByDoubleToDouble reducer) {
4455	>	return ForkJoinTasks.reduceValuesToDouble
4456	>	(map, transformer, basis, reducer).invoke();
4457	>	}
4458	>
4459	>	/**
4460	>	* Returns the result of accumulating the given transformation
4461	>	* of all values using the given reducer to combine values,
4462	>	* and the given basis as an identity value.
4463	>	*
4464	>	* @param transformer a function returning the transformation
4465	>	* for an element
4466	>	* @param basis the identity (initial default value) for the reduction
4467	>	* @param reducer a commutative associative combining function
4468	>	* @return the result of accumulating the given transformation
4469	>	* of all values
4470	>	*/
4471	>	public long reduceToLong(ObjectToLong<? super V> transformer,
4472	>	long basis,
4473	>	LongByLongToLong reducer) {
4474	>	return ForkJoinTasks.reduceValuesToLong
4475	>	(map, transformer, basis, reducer).invoke();
4476	>	}
4477	>
4478	>	/**
4479	>	* Returns the result of accumulating the given transformation
4480	>	* of all values using the given reducer to combine values,
4481	>	* and the given basis as an identity value.
4482	>	*
4483	>	* @param transformer a function returning the transformation
4484	>	* for an element
4485	>	* @param basis the identity (initial default value) for the reduction
4486	>	* @param reducer a commutative associative combining function
4487	>	* @return the result of accumulating the given transformation
4488	>	* of all values
4489	>	*/
4490	>	public int reduceToInt(ObjectToInt<? super V> transformer,
4491	>	int basis,
4492	>	IntByIntToInt reducer) {
4493	>	return ForkJoinTasks.reduceValuesToInt
4494	>	(map, transformer, basis, reducer).invoke();
4495	>	}
4496	>
4497		}
4498
4499		/**
4500	<	* Reconstitute the <tt>ConcurrentHashMap</tt>
4501	<	* instance from a stream (i.e.,
4502	<	* deserialize it).
1112	<	* @param s the stream
4500	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4501	>	* entries.  This class cannot be directly instantiated. See
4502	>	* {@link #entrySet}.
4503		*/
4504	<	private void readObject(java.io.ObjectInputStream s)
4505	<	throws IOException, ClassNotFoundException  {
4506	<	s.defaultReadObject();
4504	>	public static final class EntrySetView<K,V> extends CHMView<K,V>
4505	>	implements Set<Map.Entry<K,V>> {
4506	>	EntrySetView(ConcurrentHashMap<K, V> map) { super(map); }
4507	>	public final boolean contains(Object o) {
4508	>	Object k, v, r; Map.Entry<?,?> e;
4509	>	return ((o instanceof Map.Entry) &&
4510	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4511	>	(r = map.get(k)) != null &&
4512	>	(v = e.getValue()) != null &&
4513	>	(v == r || v.equals(r)));
4514	>	}
4515	>	public final boolean remove(Object o) {
4516	>	Object k, v; Map.Entry<?,?> e;
4517	>	return ((o instanceof Map.Entry) &&
4518	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4519	>	(v = e.getValue()) != null &&
4520	>	map.remove(k, v));
4521	>	}
4522	>
4523	>	/**
4524	>	* Returns a "weakly consistent" iterator that will never
4525	>	* throw {@link ConcurrentModificationException}, and
4526	>	* guarantees to traverse elements as they existed upon
4527	>	* construction of the iterator, and may (but is not
4528	>	* guaranteed to) reflect any modifications subsequent to
4529	>	* construction.
4530	>	*
4531	>	* @return an iterator over the entries of this map
4532	>	*/
4533	>	public final Iterator<Map.Entry<K,V>> iterator() {
4534	>	return new EntryIterator<K,V>(map);
4535	>	}
4536
4537	<	// Initialize each segment to be minimally sized, and let grow.
4538	<	for (int i = 0; i < segments.length; ++i) {
4539	<	segments[i].setTable(new HashEntry[1]);
4537	>	public final boolean add(Entry<K,V> e) {
4538	>	K key = e.getKey();
4539	>	V value = e.getValue();
4540	>	if (key == null || value == null)
4541	>	throw new NullPointerException();
4542	>	return map.internalPut(key, value) == null;
4543	>	}
4544	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4545	>	boolean added = false;
4546	>	for (Entry<K,V> e : c) {
4547	>	if (add(e))
4548	>	added = true;
4549	>	}
4550	>	return added;
4551	>	}
4552	>	public boolean equals(Object o) {
4553	>	Set<?> c;
4554	>	return ((o instanceof Set) &&
4555	>	((c = (Set<?>)o) == this ||
4556	>	(containsAll(c) && c.containsAll(this))));
4557		}
4558
4559	<	// Read the keys and values, and put the mappings in the table
4560	<	for (;;) {
4561	<	K key = (K) s.readObject();
4562	<	V value = (V) s.readObject();
4563	<	if (key == null)
4564	<	break;
4565	<	put(key, value);
4559	>	/**
4560	>	* Performs the given action for each entry.
4561	>	*
4562	>	* @param action the action
4563	>	*/
4564	>	public void forEach(Action<Map.Entry<K,V>> action) {
4565	>	ForkJoinTasks.forEachEntry
4566	>	(map, action).invoke();
4567	>	}
4568	>
4569	>	/**
4570	>	* Performs the given action for each non-null transformation
4571	>	* of each entry.
4572	>	*
4573	>	* @param transformer a function returning the transformation
4574	>	* for an element, or null of there is no transformation (in
4575	>	* which case the action is not applied).
4576	>	* @param action the action
4577	>	*/
4578	>	public <U> void forEach(Fun<Map.Entry<K,V>, ? extends U> transformer,
4579	>	Action<U> action) {
4580	>	ForkJoinTasks.forEachEntry
4581	>	(map, transformer, action).invoke();
4582	>	}
4583	>
4584	>	/**
4585	>	* Returns a non-null result from applying the given search
4586	>	* function on each entry, or null if none.  Upon success,
4587	>	* further element processing is suppressed and the results of
4588	>	* any other parallel invocations of the search function are
4589	>	* ignored.
4590	>	*
4591	>	* @param searchFunction a function returning a non-null
4592	>	* result on success, else null
4593	>	* @return a non-null result from applying the given search
4594	>	* function on each entry, or null if none
4595	>	*/
4596	>	public <U> U search(Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
4597	>	return ForkJoinTasks.searchEntries
4598	>	(map, searchFunction).invoke();
4599	>	}
4600	>
4601	>	/**
4602	>	* Returns the result of accumulating all entries using the
4603	>	* given reducer to combine values, or null if none.
4604	>	*
4605	>	* @param reducer a commutative associative combining function
4606	>	* @return the result of accumulating all entries
4607	>	*/
4608	>	public Map.Entry<K,V> reduce(BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4609	>	return ForkJoinTasks.reduceEntries
4610	>	(map, reducer).invoke();
4611	>	}
4612	>
4613	>	/**
4614	>	* Returns the result of accumulating the given transformation
4615	>	* of all entries using the given reducer to combine values,
4616	>	* or null if none.
4617	>	*
4618	>	* @param transformer a function returning the transformation
4619	>	* for an element, or null of there is no transformation (in
4620	>	* which case it is not combined).
4621	>	* @param reducer a commutative associative combining function
4622	>	* @return the result of accumulating the given transformation
4623	>	* of all entries
4624	>	*/
4625	>	public <U> U reduce(Fun<Map.Entry<K,V>, ? extends U> transformer,
4626	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4627	>	return ForkJoinTasks.reduceEntries
4628	>	(map, transformer, reducer).invoke();
4629	>	}
4630	>
4631	>	/**
4632	>	* Returns the result of accumulating the given transformation
4633	>	* of all entries using the given reducer to combine values,
4634	>	* and the given basis as an identity value.
4635	>	*
4636	>	* @param transformer a function returning the transformation
4637	>	* for an element
4638	>	* @param basis the identity (initial default value) for the reduction
4639	>	* @param reducer a commutative associative combining function
4640	>	* @return the result of accumulating the given transformation
4641	>	* of all entries
4642	>	*/
4643	>	public double reduceToDouble(ObjectToDouble<Map.Entry<K,V>> transformer,
4644	>	double basis,
4645	>	DoubleByDoubleToDouble reducer) {
4646	>	return ForkJoinTasks.reduceEntriesToDouble
4647	>	(map, transformer, basis, reducer).invoke();
4648	>	}
4649	>
4650	>	/**
4651	>	* Returns the result of accumulating the given transformation
4652	>	* of all entries using the given reducer to combine values,
4653	>	* and the given basis as an identity value.
4654	>	*
4655	>	* @param transformer a function returning the transformation
4656	>	* for an element
4657	>	* @param basis the identity (initial default value) for the reduction
4658	>	* @param reducer a commutative associative combining function
4659	>	* @return  the result of accumulating the given transformation
4660	>	* of all entries
4661	>	*/
4662	>	public long reduceToLong(ObjectToLong<Map.Entry<K,V>> transformer,
4663	>	long basis,
4664	>	LongByLongToLong reducer) {
4665	>	return ForkJoinTasks.reduceEntriesToLong
4666	>	(map, transformer, basis, reducer).invoke();
4667	>	}
4668	>
4669	>	/**
4670	>	* Returns the result of accumulating the given transformation
4671	>	* of all entries using the given reducer to combine values,
4672	>	* and the given basis as an identity value.
4673	>	*
4674	>	* @param transformer a function returning the transformation
4675	>	* for an element
4676	>	* @param basis the identity (initial default value) for the reduction
4677	>	* @param reducer a commutative associative combining function
4678	>	* @return the result of accumulating the given transformation
4679	>	* of all entries
4680	>	*/
4681	>	public int reduceToInt(ObjectToInt<Map.Entry<K,V>> transformer,
4682	>	int basis,
4683	>	IntByIntToInt reducer) {
4684	>	return ForkJoinTasks.reduceEntriesToInt
4685	>	(map, transformer, basis, reducer).invoke();
4686	>	}
4687	>
4688	>	}
4689	>
4690	>	// ---------------------------------------------------------------------
4691	>
4692	>	/**
4693	>	* Predefined tasks for performing bulk parallel operations on
4694	>	* ConcurrentHashMaps. These tasks follow the forms and rules used
4695	>	* for bulk operations. Each method has the same name, but returns
4696	>	* a task rather than invoking it. These methods may be useful in
4697	>	* custom applications such as submitting a task without waiting
4698	>	* for completion, using a custom pool, or combining with other
4699	>	* tasks.
4700	>	*/
4701	>	public static class ForkJoinTasks {
4702	>	private ForkJoinTasks() {}
4703	>
4704	>	/**
4705	>	* Returns a task that when invoked, performs the given
4706	>	* action for each (key, value)
4707	>	*
4708	>	* @param map the map
4709	>	* @param action the action
4710	>	* @return the task
4711	>	*/
4712	>	public static <K,V> ForkJoinTask<Void> forEach
4713	>	(ConcurrentHashMap<K,V> map,
4714	>	BiAction<K,V> action) {
4715	>	if (action == null) throw new NullPointerException();
4716	>	return new ForEachMappingTask<K,V>(map, null, -1, action);
4717	>	}
4718	>
4719	>	/**
4720	>	* Returns a task that when invoked, performs the given
4721	>	* action for each non-null transformation of each (key, value)
4722	>	*
4723	>	* @param map the map
4724	>	* @param transformer a function returning the transformation
4725	>	* for an element, or null if there is no transformation (in
4726	>	* which case the action is not applied)
4727	>	* @param action the action
4728	>	* @return the task
4729	>	*/
4730	>	public static <K,V,U> ForkJoinTask<Void> forEach
4731	>	(ConcurrentHashMap<K,V> map,
4732	>	BiFun<? super K, ? super V, ? extends U> transformer,
4733	>	Action<U> action) {
4734	>	if (transformer == null || action == null)
4735	>	throw new NullPointerException();
4736	>	return new ForEachTransformedMappingTask<K,V,U>
4737	>	(map, null, -1, transformer, action);
4738	>	}
4739	>
4740	>	/**
4741	>	* Returns a task that when invoked, returns a non-null result
4742	>	* from applying the given search function on each (key,
4743	>	* value), or null if none. Upon success, further element
4744	>	* processing is suppressed and the results of any other
4745	>	* parallel invocations of the search function are ignored.
4746	>	*
4747	>	* @param map the map
4748	>	* @param searchFunction a function returning a non-null
4749	>	* result on success, else null
4750	>	* @return the task
4751	>	*/
4752	>	public static <K,V,U> ForkJoinTask<U> search
4753	>	(ConcurrentHashMap<K,V> map,
4754	>	BiFun<? super K, ? super V, ? extends U> searchFunction) {
4755	>	if (searchFunction == null) throw new NullPointerException();
4756	>	return new SearchMappingsTask<K,V,U>
4757	>	(map, null, -1, searchFunction,
4758	>	new AtomicReference<U>());
4759	>	}
4760	>
4761	>	/**
4762	>	* Returns a task that when invoked, returns the result of
4763	>	* accumulating the given transformation of all (key, value) pairs
4764	>	* using the given reducer to combine values, or null if none.
4765	>	*
4766	>	* @param map the map
4767	>	* @param transformer a function returning the transformation
4768	>	* for an element, or null if there is no transformation (in
4769	>	* which case it is not combined).
4770	>	* @param reducer a commutative associative combining function
4771	>	* @return the task
4772	>	*/
4773	>	public static <K,V,U> ForkJoinTask<U> reduce
4774	>	(ConcurrentHashMap<K,V> map,
4775	>	BiFun<? super K, ? super V, ? extends U> transformer,
4776	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4777	>	if (transformer == null || reducer == null)
4778	>	throw new NullPointerException();
4779	>	return new MapReduceMappingsTask<K,V,U>
4780	>	(map, null, -1, null, transformer, reducer);
4781	>	}
4782	>
4783	>	/**
4784	>	* Returns a task that when invoked, returns the result of
4785	>	* accumulating the given transformation of all (key, value) pairs
4786	>	* using the given reducer to combine values, and the given
4787	>	* basis as an identity value.
4788	>	*
4789	>	* @param map the map
4790	>	* @param transformer a function returning the transformation
4791	>	* for an element
4792	>	* @param basis the identity (initial default value) for the reduction
4793	>	* @param reducer a commutative associative combining function
4794	>	* @return the task
4795	>	*/
4796	>	public static <K,V> ForkJoinTask<Double> reduceToDouble
4797	>	(ConcurrentHashMap<K,V> map,
4798	>	ObjectByObjectToDouble<? super K, ? super V> transformer,
4799	>	double basis,
4800	>	DoubleByDoubleToDouble reducer) {
4801	>	if (transformer == null || reducer == null)
4802	>	throw new NullPointerException();
4803	>	return new MapReduceMappingsToDoubleTask<K,V>
4804	>	(map, null, -1, null, transformer, basis, reducer);
4805	>	}
4806	>
4807	>	/**
4808	>	* Returns a task that when invoked, returns the result of
4809	>	* accumulating the given transformation of all (key, value) pairs
4810	>	* using the given reducer to combine values, and the given
4811	>	* basis as an identity value.
4812	>	*
4813	>	* @param map the map
4814	>	* @param transformer a function returning the transformation
4815	>	* for an element
4816	>	* @param basis the identity (initial default value) for the reduction
4817	>	* @param reducer a commutative associative combining function
4818	>	* @return the task
4819	>	*/
4820	>	public static <K,V> ForkJoinTask<Long> reduceToLong
4821	>	(ConcurrentHashMap<K,V> map,
4822	>	ObjectByObjectToLong<? super K, ? super V> transformer,
4823	>	long basis,
4824	>	LongByLongToLong reducer) {
4825	>	if (transformer == null || reducer == null)
4826	>	throw new NullPointerException();
4827	>	return new MapReduceMappingsToLongTask<K,V>
4828	>	(map, null, -1, null, transformer, basis, reducer);
4829	>	}
4830	>
4831	>	/**
4832	>	* Returns a task that when invoked, returns the result of
4833	>	* accumulating the given transformation of all (key, value) pairs
4834	>	* using the given reducer to combine values, and the given
4835	>	* basis as an identity value.
4836	>	*
4837	>	* @param transformer a function returning the transformation
4838	>	* for an element
4839	>	* @param basis the identity (initial default value) for the reduction
4840	>	* @param reducer a commutative associative combining function
4841	>	* @return the task
4842	>	*/
4843	>	public static <K,V> ForkJoinTask<Integer> reduceToInt
4844	>	(ConcurrentHashMap<K,V> map,
4845	>	ObjectByObjectToInt<? super K, ? super V> transformer,
4846	>	int basis,
4847	>	IntByIntToInt reducer) {
4848	>	if (transformer == null || reducer == null)
4849	>	throw new NullPointerException();
4850	>	return new MapReduceMappingsToIntTask<K,V>
4851	>	(map, null, -1, null, transformer, basis, reducer);
4852	>	}
4853	>
4854	>	/**
4855	>	* Returns a task that when invoked, performs the given action
4856	>	* for each key.
4857	>	*
4858	>	* @param map the map
4859	>	* @param action the action
4860	>	* @return the task
4861	>	*/
4862	>	public static <K,V> ForkJoinTask<Void> forEachKey
4863	>	(ConcurrentHashMap<K,V> map,
4864	>	Action<K> action) {
4865	>	if (action == null) throw new NullPointerException();
4866	>	return new ForEachKeyTask<K,V>(map, null, -1, action);
4867	>	}
4868	>
4869	>	/**
4870	>	* Returns a task that when invoked, performs the given action
4871	>	* for each non-null transformation of each key.
4872	>	*
4873	>	* @param map the map
4874	>	* @param transformer a function returning the transformation
4875	>	* for an element, or null if there is no transformation (in
4876	>	* which case the action is not applied)
4877	>	* @param action the action
4878	>	* @return the task
4879	>	*/
4880	>	public static <K,V,U> ForkJoinTask<Void> forEachKey
4881	>	(ConcurrentHashMap<K,V> map,
4882	>	Fun<? super K, ? extends U> transformer,
4883	>	Action<U> action) {
4884	>	if (transformer == null || action == null)
4885	>	throw new NullPointerException();
4886	>	return new ForEachTransformedKeyTask<K,V,U>
4887	>	(map, null, -1, transformer, action);
4888	>	}
4889	>
4890	>	/**
4891	>	* Returns a task that when invoked, returns a non-null result
4892	>	* from applying the given search function on each key, or
4893	>	* null if none.  Upon success, further element processing is
4894	>	* suppressed and the results of any other parallel
4895	>	* invocations of the search function are ignored.
4896	>	*
4897	>	* @param map the map
4898	>	* @param searchFunction a function returning a non-null
4899	>	* result on success, else null
4900	>	* @return the task
4901	>	*/
4902	>	public static <K,V,U> ForkJoinTask<U> searchKeys
4903	>	(ConcurrentHashMap<K,V> map,
4904	>	Fun<? super K, ? extends U> searchFunction) {
4905	>	if (searchFunction == null) throw new NullPointerException();
4906	>	return new SearchKeysTask<K,V,U>
4907	>	(map, null, -1, searchFunction,
4908	>	new AtomicReference<U>());
4909	>	}
4910	>
4911	>	/**
4912	>	* Returns a task that when invoked, returns the result of
4913	>	* accumulating all keys using the given reducer to combine
4914	>	* values, or null if none.
4915	>	*
4916	>	* @param map the map
4917	>	* @param reducer a commutative associative combining function
4918	>	* @return the task
4919	>	*/
4920	>	public static <K,V> ForkJoinTask<K> reduceKeys
4921	>	(ConcurrentHashMap<K,V> map,
4922	>	BiFun<? super K, ? super K, ? extends K> reducer) {
4923	>	if (reducer == null) throw new NullPointerException();
4924	>	return new ReduceKeysTask<K,V>
4925	>	(map, null, -1, null, reducer);
4926	>	}
4927	>
4928	>	/**
4929	>	* Returns a task that when invoked, returns the result of
4930	>	* accumulating the given transformation of all keys using the given
4931	>	* reducer to combine values, or null if none.
4932	>	*
4933	>	* @param map the map
4934	>	* @param transformer a function returning the transformation
4935	>	* for an element, or null if there is no transformation (in
4936	>	* which case it is not combined).
4937	>	* @param reducer a commutative associative combining function
4938	>	* @return the task
4939	>	*/
4940	>	public static <K,V,U> ForkJoinTask<U> reduceKeys
4941	>	(ConcurrentHashMap<K,V> map,
4942	>	Fun<? super K, ? extends U> transformer,
4943	>	BiFun<? super U, ? super U, ? extends U> reducer) {
4944	>	if (transformer == null || reducer == null)
4945	>	throw new NullPointerException();
4946	>	return new MapReduceKeysTask<K,V,U>
4947	>	(map, null, -1, null, transformer, reducer);
4948	>	}
4949	>
4950	>	/**
4951	>	* Returns a task that when invoked, returns the result of
4952	>	* accumulating the given transformation of all keys using the given
4953	>	* reducer to combine values, and the given basis as an
4954	>	* identity value.
4955	>	*
4956	>	* @param map the map
4957	>	* @param transformer a function returning the transformation
4958	>	* for an element
4959	>	* @param basis the identity (initial default value) for the reduction
4960	>	* @param reducer a commutative associative combining function
4961	>	* @return the task
4962	>	*/
4963	>	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
4964	>	(ConcurrentHashMap<K,V> map,
4965	>	ObjectToDouble<? super K> transformer,
4966	>	double basis,
4967	>	DoubleByDoubleToDouble reducer) {
4968	>	if (transformer == null || reducer == null)
4969	>	throw new NullPointerException();
4970	>	return new MapReduceKeysToDoubleTask<K,V>
4971	>	(map, null, -1, null, transformer, basis, reducer);
4972	>	}
4973	>
4974	>	/**
4975	>	* Returns a task that when invoked, returns the result of
4976	>	* accumulating the given transformation of all keys using the given
4977	>	* reducer to combine values, and the given basis as an
4978	>	* identity value.
4979	>	*
4980	>	* @param map the map
4981	>	* @param transformer a function returning the transformation
4982	>	* for an element
4983	>	* @param basis the identity (initial default value) for the reduction
4984	>	* @param reducer a commutative associative combining function
4985	>	* @return the task
4986	>	*/
4987	>	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
4988	>	(ConcurrentHashMap<K,V> map,
4989	>	ObjectToLong<? super K> transformer,
4990	>	long basis,
4991	>	LongByLongToLong reducer) {
4992	>	if (transformer == null || reducer == null)
4993	>	throw new NullPointerException();
4994	>	return new MapReduceKeysToLongTask<K,V>
4995	>	(map, null, -1, null, transformer, basis, reducer);
4996	>	}
4997	>
4998	>	/**
4999	>	* Returns a task that when invoked, returns the result of
5000	>	* accumulating the given transformation of all keys using the given
5001	>	* reducer to combine values, and the given basis as an
5002	>	* identity value.
5003	>	*
5004	>	* @param map the map
5005	>	* @param transformer a function returning the transformation
5006	>	* for an element
5007	>	* @param basis the identity (initial default value) for the reduction
5008	>	* @param reducer a commutative associative combining function
5009	>	* @return the task
5010	>	*/
5011	>	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5012	>	(ConcurrentHashMap<K,V> map,
5013	>	ObjectToInt<? super K> transformer,
5014	>	int basis,
5015	>	IntByIntToInt reducer) {
5016	>	if (transformer == null || reducer == null)
5017	>	throw new NullPointerException();
5018	>	return new MapReduceKeysToIntTask<K,V>
5019	>	(map, null, -1, null, transformer, basis, reducer);
5020	>	}
5021	>
5022	>	/**
5023	>	* Returns a task that when invoked, performs the given action
5024	>	* for each value.
5025	>	*
5026	>	* @param map the map
5027	>	* @param action the action
5028	>	*/
5029	>	public static <K,V> ForkJoinTask<Void> forEachValue
5030	>	(ConcurrentHashMap<K,V> map,
5031	>	Action<V> action) {
5032	>	if (action == null) throw new NullPointerException();
5033	>	return new ForEachValueTask<K,V>(map, null, -1, action);
5034	>	}
5035	>
5036	>	/**
5037	>	* Returns a task that when invoked, performs the given action
5038	>	* for each non-null transformation of each value.
5039	>	*
5040	>	* @param map the map
5041	>	* @param transformer a function returning the transformation
5042	>	* for an element, or null if there is no transformation (in
5043	>	* which case the action is not applied)
5044	>	* @param action the action
5045	>	*/
5046	>	public static <K,V,U> ForkJoinTask<Void> forEachValue
5047	>	(ConcurrentHashMap<K,V> map,
5048	>	Fun<? super V, ? extends U> transformer,
5049	>	Action<U> action) {
5050	>	if (transformer == null || action == null)
5051	>	throw new NullPointerException();
5052	>	return new ForEachTransformedValueTask<K,V,U>
5053	>	(map, null, -1, transformer, action);
5054	>	}
5055	>
5056	>	/**
5057	>	* Returns a task that when invoked, returns a non-null result
5058	>	* from applying the given search function on each value, or
5059	>	* null if none.  Upon success, further element processing is
5060	>	* suppressed and the results of any other parallel
5061	>	* invocations of the search function are ignored.
5062	>	*
5063	>	* @param map the map
5064	>	* @param searchFunction a function returning a non-null
5065	>	* result on success, else null
5066	>	* @return the task
5067	>	*/
5068	>	public static <K,V,U> ForkJoinTask<U> searchValues
5069	>	(ConcurrentHashMap<K,V> map,
5070	>	Fun<? super V, ? extends U> searchFunction) {
5071	>	if (searchFunction == null) throw new NullPointerException();
5072	>	return new SearchValuesTask<K,V,U>
5073	>	(map, null, -1, searchFunction,
5074	>	new AtomicReference<U>());
5075	>	}
5076	>
5077	>	/**
5078	>	* Returns a task that when invoked, returns the result of
5079	>	* accumulating all values using the given reducer to combine
5080	>	* values, or null if none.
5081	>	*
5082	>	* @param map the map
5083	>	* @param reducer a commutative associative combining function
5084	>	* @return the task
5085	>	*/
5086	>	public static <K,V> ForkJoinTask<V> reduceValues
5087	>	(ConcurrentHashMap<K,V> map,
5088	>	BiFun<? super V, ? super V, ? extends V> reducer) {
5089	>	if (reducer == null) throw new NullPointerException();
5090	>	return new ReduceValuesTask<K,V>
5091	>	(map, null, -1, null, reducer);
5092	>	}
5093	>
5094	>	/**
5095	>	* Returns a task that when invoked, returns the result of
5096	>	* accumulating the given transformation of all values using the
5097	>	* given reducer to combine values, or null if none.
5098	>	*
5099	>	* @param map the map
5100	>	* @param transformer a function returning the transformation
5101	>	* for an element, or null if there is no transformation (in
5102	>	* which case it is not combined).
5103	>	* @param reducer a commutative associative combining function
5104	>	* @return the task
5105	>	*/
5106	>	public static <K,V,U> ForkJoinTask<U> reduceValues
5107	>	(ConcurrentHashMap<K,V> map,
5108	>	Fun<? super V, ? extends U> transformer,
5109	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5110	>	if (transformer == null || reducer == null)
5111	>	throw new NullPointerException();
5112	>	return new MapReduceValuesTask<K,V,U>
5113	>	(map, null, -1, null, transformer, reducer);
5114	>	}
5115	>
5116	>	/**
5117	>	* Returns a task that when invoked, returns the result of
5118	>	* accumulating the given transformation of all values using the
5119	>	* given reducer to combine values, and the given basis as an
5120	>	* identity value.
5121	>	*
5122	>	* @param map the map
5123	>	* @param transformer a function returning the transformation
5124	>	* for an element
5125	>	* @param basis the identity (initial default value) for the reduction
5126	>	* @param reducer a commutative associative combining function
5127	>	* @return the task
5128	>	*/
5129	>	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5130	>	(ConcurrentHashMap<K,V> map,
5131	>	ObjectToDouble<? super V> transformer,
5132	>	double basis,
5133	>	DoubleByDoubleToDouble reducer) {
5134	>	if (transformer == null || reducer == null)
5135	>	throw new NullPointerException();
5136	>	return new MapReduceValuesToDoubleTask<K,V>
5137	>	(map, null, -1, null, transformer, basis, reducer);
5138	>	}
5139	>
5140	>	/**
5141	>	* Returns a task that when invoked, returns the result of
5142	>	* accumulating the given transformation of all values using the
5143	>	* given reducer to combine values, and the given basis as an
5144	>	* identity value.
5145	>	*
5146	>	* @param map the map
5147	>	* @param transformer a function returning the transformation
5148	>	* for an element
5149	>	* @param basis the identity (initial default value) for the reduction
5150	>	* @param reducer a commutative associative combining function
5151	>	* @return the task
5152	>	*/
5153	>	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5154	>	(ConcurrentHashMap<K,V> map,
5155	>	ObjectToLong<? super V> transformer,
5156	>	long basis,
5157	>	LongByLongToLong reducer) {
5158	>	if (transformer == null || reducer == null)
5159	>	throw new NullPointerException();
5160	>	return new MapReduceValuesToLongTask<K,V>
5161	>	(map, null, -1, null, transformer, basis, reducer);
5162	>	}
5163	>
5164	>	/**
5165	>	* Returns a task that when invoked, returns the result of
5166	>	* accumulating the given transformation of all values using the
5167	>	* given reducer to combine values, and the given basis as an
5168	>	* identity value.
5169	>	*
5170	>	* @param map the map
5171	>	* @param transformer a function returning the transformation
5172	>	* for an element
5173	>	* @param basis the identity (initial default value) for the reduction
5174	>	* @param reducer a commutative associative combining function
5175	>	* @return the task
5176	>	*/
5177	>	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5178	>	(ConcurrentHashMap<K,V> map,
5179	>	ObjectToInt<? super V> transformer,
5180	>	int basis,
5181	>	IntByIntToInt reducer) {
5182	>	if (transformer == null || reducer == null)
5183	>	throw new NullPointerException();
5184	>	return new MapReduceValuesToIntTask<K,V>
5185	>	(map, null, -1, null, transformer, basis, reducer);
5186	>	}
5187	>
5188	>	/**
5189	>	* Returns a task that when invoked, perform the given action
5190	>	* for each entry.
5191	>	*
5192	>	* @param map the map
5193	>	* @param action the action
5194	>	*/
5195	>	public static <K,V> ForkJoinTask<Void> forEachEntry
5196	>	(ConcurrentHashMap<K,V> map,
5197	>	Action<Map.Entry<K,V>> action) {
5198	>	if (action == null) throw new NullPointerException();
5199	>	return new ForEachEntryTask<K,V>(map, null, -1, action);
5200	>	}
5201	>
5202	>	/**
5203	>	* Returns a task that when invoked, perform the given action
5204	>	* for each non-null transformation of each entry.
5205	>	*
5206	>	* @param map the map
5207	>	* @param transformer a function returning the transformation
5208	>	* for an element, or null if there is no transformation (in
5209	>	* which case the action is not applied)
5210	>	* @param action the action
5211	>	*/
5212	>	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5213	>	(ConcurrentHashMap<K,V> map,
5214	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5215	>	Action<U> action) {
5216	>	if (transformer == null || action == null)
5217	>	throw new NullPointerException();
5218	>	return new ForEachTransformedEntryTask<K,V,U>
5219	>	(map, null, -1, transformer, action);
5220	>	}
5221	>
5222	>	/**
5223	>	* Returns a task that when invoked, returns a non-null result
5224	>	* from applying the given search function on each entry, or
5225	>	* null if none.  Upon success, further element processing is
5226	>	* suppressed and the results of any other parallel
5227	>	* invocations of the search function are ignored.
5228	>	*
5229	>	* @param map the map
5230	>	* @param searchFunction a function returning a non-null
5231	>	* result on success, else null
5232	>	* @return the task
5233	>	*/
5234	>	public static <K,V,U> ForkJoinTask<U> searchEntries
5235	>	(ConcurrentHashMap<K,V> map,
5236	>	Fun<Map.Entry<K,V>, ? extends U> searchFunction) {
5237	>	if (searchFunction == null) throw new NullPointerException();
5238	>	return new SearchEntriesTask<K,V,U>
5239	>	(map, null, -1, searchFunction,
5240	>	new AtomicReference<U>());
5241	>	}
5242	>
5243	>	/**
5244	>	* Returns a task that when invoked, returns the result of
5245	>	* accumulating all entries using the given reducer to combine
5246	>	* values, or null if none.
5247	>	*
5248	>	* @param map the map
5249	>	* @param reducer a commutative associative combining function
5250	>	* @return the task
5251	>	*/
5252	>	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5253	>	(ConcurrentHashMap<K,V> map,
5254	>	BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5255	>	if (reducer == null) throw new NullPointerException();
5256	>	return new ReduceEntriesTask<K,V>
5257	>	(map, null, -1, null, reducer);
5258	>	}
5259	>
5260	>	/**
5261	>	* Returns a task that when invoked, returns the result of
5262	>	* accumulating the given transformation of all entries using the
5263	>	* given reducer to combine values, or null if none.
5264	>	*
5265	>	* @param map the map
5266	>	* @param transformer a function returning the transformation
5267	>	* for an element, or null if there is no transformation (in
5268	>	* which case it is not combined).
5269	>	* @param reducer a commutative associative combining function
5270	>	* @return the task
5271	>	*/
5272	>	public static <K,V,U> ForkJoinTask<U> reduceEntries
5273	>	(ConcurrentHashMap<K,V> map,
5274	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5275	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5276	>	if (transformer == null || reducer == null)
5277	>	throw new NullPointerException();
5278	>	return new MapReduceEntriesTask<K,V,U>
5279	>	(map, null, -1, null, transformer, reducer);
5280	>	}
5281	>
5282	>	/**
5283	>	* Returns a task that when invoked, returns the result of
5284	>	* accumulating the given transformation of all entries using the
5285	>	* given reducer to combine values, and the given basis as an
5286	>	* identity value.
5287	>	*
5288	>	* @param map the map
5289	>	* @param transformer a function returning the transformation
5290	>	* for an element
5291	>	* @param basis the identity (initial default value) for the reduction
5292	>	* @param reducer a commutative associative combining function
5293	>	* @return the task
5294	>	*/
5295	>	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5296	>	(ConcurrentHashMap<K,V> map,
5297	>	ObjectToDouble<Map.Entry<K,V>> transformer,
5298	>	double basis,
5299	>	DoubleByDoubleToDouble reducer) {
5300	>	if (transformer == null || reducer == null)
5301	>	throw new NullPointerException();
5302	>	return new MapReduceEntriesToDoubleTask<K,V>
5303	>	(map, null, -1, null, transformer, basis, reducer);
5304	>	}
5305	>
5306	>	/**
5307	>	* Returns a task that when invoked, returns the result of
5308	>	* accumulating the given transformation of all entries using the
5309	>	* given reducer to combine values, and the given basis as an
5310	>	* identity value.
5311	>	*
5312	>	* @param map the map
5313	>	* @param transformer a function returning the transformation
5314	>	* for an element
5315	>	* @param basis the identity (initial default value) for the reduction
5316	>	* @param reducer a commutative associative combining function
5317	>	* @return the task
5318	>	*/
5319	>	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5320	>	(ConcurrentHashMap<K,V> map,
5321	>	ObjectToLong<Map.Entry<K,V>> transformer,
5322	>	long basis,
5323	>	LongByLongToLong reducer) {
5324	>	if (transformer == null || reducer == null)
5325	>	throw new NullPointerException();
5326	>	return new MapReduceEntriesToLongTask<K,V>
5327	>	(map, null, -1, null, transformer, basis, reducer);
5328	>	}
5329	>
5330	>	/**
5331	>	* Returns a task that when invoked, returns the result of
5332	>	* accumulating the given transformation of all entries using the
5333	>	* given reducer to combine values, and the given basis as an
5334	>	* identity value.
5335	>	*
5336	>	* @param map the map
5337	>	* @param transformer a function returning the transformation
5338	>	* for an element
5339	>	* @param basis the identity (initial default value) for the reduction
5340	>	* @param reducer a commutative associative combining function
5341	>	* @return the task
5342	>	*/
5343	>	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5344	>	(ConcurrentHashMap<K,V> map,
5345	>	ObjectToInt<Map.Entry<K,V>> transformer,
5346	>	int basis,
5347	>	IntByIntToInt reducer) {
5348	>	if (transformer == null || reducer == null)
5349	>	throw new NullPointerException();
5350	>	return new MapReduceEntriesToIntTask<K,V>
5351	>	(map, null, -1, null, transformer, basis, reducer);
5352	>	}
5353	>	}
5354	>
5355	>	// -------------------------------------------------------
5356	>
5357	>	/*
5358	>	* Task classes. Coded in a regular but ugly format/style to
5359	>	* simplify checks that each variant differs in the right way from
5360	>	* others.
5361	>	*/
5362	>
5363	>	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5364	>	extends Traverser<K,V,Void> {
5365	>	final Action<K> action;
5366	>	ForEachKeyTask
5367	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5368	>	Action<K> action) {
5369	>	super(m, p, b);
5370	>	this.action = action;
5371	>	}
5372	>	@SuppressWarnings("unchecked") public final void compute() {
5373	>	final Action<K> action;
5374	>	if ((action = this.action) == null)
5375	>	throw new NullPointerException();
5376	>	for (int b; (b = preSplit()) > 0;)
5377	>	new ForEachKeyTask<K,V>(map, this, b, action).fork();
5378	>	while (advance() != null)
5379	>	action.apply((K)nextKey);
5380	>	propagateCompletion();
5381	>	}
5382	>	}
5383	>
5384	>	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5385	>	extends Traverser<K,V,Void> {
5386	>	final Action<V> action;
5387	>	ForEachValueTask
5388	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5389	>	Action<V> action) {
5390	>	super(m, p, b);
5391	>	this.action = action;
5392	>	}
5393	>	@SuppressWarnings("unchecked") public final void compute() {
5394	>	final Action<V> action;
5395	>	if ((action = this.action) == null)
5396	>	throw new NullPointerException();
5397	>	for (int b; (b = preSplit()) > 0;)
5398	>	new ForEachValueTask<K,V>(map, this, b, action).fork();
5399	>	Object v;
5400	>	while ((v = advance()) != null)
5401	>	action.apply((V)v);
5402	>	propagateCompletion();
5403	>	}
5404	>	}
5405	>
5406	>	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5407	>	extends Traverser<K,V,Void> {
5408	>	final Action<Entry<K,V>> action;
5409	>	ForEachEntryTask
5410	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5411	>	Action<Entry<K,V>> action) {
5412	>	super(m, p, b);
5413	>	this.action = action;
5414	>	}
5415	>	@SuppressWarnings("unchecked") public final void compute() {
5416	>	final Action<Entry<K,V>> action;
5417	>	if ((action = this.action) == null)
5418	>	throw new NullPointerException();
5419	>	for (int b; (b = preSplit()) > 0;)
5420	>	new ForEachEntryTask<K,V>(map, this, b, action).fork();
5421	>	Object v;
5422	>	while ((v = advance()) != null)
5423	>	action.apply(entryFor((K)nextKey, (V)v));
5424	>	propagateCompletion();
5425	>	}
5426	>	}
5427	>
5428	>	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5429	>	extends Traverser<K,V,Void> {
5430	>	final BiAction<K,V> action;
5431	>	ForEachMappingTask
5432	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5433	>	BiAction<K,V> action) {
5434	>	super(m, p, b);
5435	>	this.action = action;
5436	>	}
5437	>	@SuppressWarnings("unchecked") public final void compute() {
5438	>	final BiAction<K,V> action;
5439	>	if ((action = this.action) == null)
5440	>	throw new NullPointerException();
5441	>	for (int b; (b = preSplit()) > 0;)
5442	>	new ForEachMappingTask<K,V>(map, this, b, action).fork();
5443	>	Object v;
5444	>	while ((v = advance()) != null)
5445	>	action.apply((K)nextKey, (V)v);
5446	>	propagateCompletion();
5447	>	}
5448	>	}
5449	>
5450	>	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5451	>	extends Traverser<K,V,Void> {
5452	>	final Fun<? super K, ? extends U> transformer;
5453	>	final Action<U> action;
5454	>	ForEachTransformedKeyTask
5455	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5456	>	Fun<? super K, ? extends U> transformer, Action<U> action) {
5457	>	super(m, p, b);
5458	>	this.transformer = transformer; this.action = action;
5459	>	}
5460	>	@SuppressWarnings("unchecked") public final void compute() {
5461	>	final Fun<? super K, ? extends U> transformer;
5462	>	final Action<U> action;
5463	>	if ((transformer = this.transformer) == null ||
5464	>	(action = this.action) == null)
5465	>	throw new NullPointerException();
5466	>	for (int b; (b = preSplit()) > 0;)
5467	>	new ForEachTransformedKeyTask<K,V,U>
5468	>	(map, this, b, transformer, action).fork();
5469	>	U u;
5470	>	while (advance() != null) {
5471	>	if ((u = transformer.apply((K)nextKey)) != null)
5472	>	action.apply(u);
5473	>	}
5474	>	propagateCompletion();
5475	>	}
5476	>	}
5477	>
5478	>	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5479	>	extends Traverser<K,V,Void> {
5480	>	final Fun<? super V, ? extends U> transformer;
5481	>	final Action<U> action;
5482	>	ForEachTransformedValueTask
5483	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5484	>	Fun<? super V, ? extends U> transformer, Action<U> action) {
5485	>	super(m, p, b);
5486	>	this.transformer = transformer; this.action = action;
5487	>	}
5488	>	@SuppressWarnings("unchecked") public final void compute() {
5489	>	final Fun<? super V, ? extends U> transformer;
5490	>	final Action<U> action;
5491	>	if ((transformer = this.transformer) == null ||
5492	>	(action = this.action) == null)
5493	>	throw new NullPointerException();
5494	>	for (int b; (b = preSplit()) > 0;)
5495	>	new ForEachTransformedValueTask<K,V,U>
5496	>	(map, this, b, transformer, action).fork();
5497	>	Object v; U u;
5498	>	while ((v = advance()) != null) {
5499	>	if ((u = transformer.apply((V)v)) != null)
5500	>	action.apply(u);
5501	>	}
5502	>	propagateCompletion();
5503	>	}
5504	>	}
5505	>
5506	>	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5507	>	extends Traverser<K,V,Void> {
5508	>	final Fun<Map.Entry<K,V>, ? extends U> transformer;
5509	>	final Action<U> action;
5510	>	ForEachTransformedEntryTask
5511	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5512	>	Fun<Map.Entry<K,V>, ? extends U> transformer, Action<U> action) {
5513	>	super(m, p, b);
5514	>	this.transformer = transformer; this.action = action;
5515	>	}
5516	>	@SuppressWarnings("unchecked") public final void compute() {
5517	>	final Fun<Map.Entry<K,V>, ? extends U> transformer;
5518	>	final Action<U> action;
5519	>	if ((transformer = this.transformer) == null ||
5520	>	(action = this.action) == null)
5521	>	throw new NullPointerException();
5522	>	for (int b; (b = preSplit()) > 0;)
5523	>	new ForEachTransformedEntryTask<K,V,U>
5524	>	(map, this, b, transformer, action).fork();
5525	>	Object v; U u;
5526	>	while ((v = advance()) != null) {
5527	>	if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
5528	>	action.apply(u);
5529	>	}
5530	>	propagateCompletion();
5531	>	}
5532	>	}
5533	>
5534	>	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5535	>	extends Traverser<K,V,Void> {
5536	>	final BiFun<? super K, ? super V, ? extends U> transformer;
5537	>	final Action<U> action;
5538	>	ForEachTransformedMappingTask
5539	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5540	>	BiFun<? super K, ? super V, ? extends U> transformer,
5541	>	Action<U> action) {
5542	>	super(m, p, b);
5543	>	this.transformer = transformer; this.action = action;
5544	>	}
5545	>	@SuppressWarnings("unchecked") public final void compute() {
5546	>	final BiFun<? super K, ? super V, ? extends U> transformer;
5547	>	final Action<U> action;
5548	>	if ((transformer = this.transformer) == null ||
5549	>	(action = this.action) == null)
5550	>	throw new NullPointerException();
5551	>	for (int b; (b = preSplit()) > 0;)
5552	>	new ForEachTransformedMappingTask<K,V,U>
5553	>	(map, this, b, transformer, action).fork();
5554	>	Object v; U u;
5555	>	while ((v = advance()) != null) {
5556	>	if ((u = transformer.apply((K)nextKey, (V)v)) != null)
5557	>	action.apply(u);
5558	>	}
5559	>	propagateCompletion();
5560	>	}
5561	>	}
5562	>
5563	>	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5564	>	extends Traverser<K,V,U> {
5565	>	final Fun<? super K, ? extends U> searchFunction;
5566	>	final AtomicReference<U> result;
5567	>	SearchKeysTask
5568	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5569	>	Fun<? super K, ? extends U> searchFunction,
5570	>	AtomicReference<U> result) {
5571	>	super(m, p, b);
5572	>	this.searchFunction = searchFunction; this.result = result;
5573	>	}
5574	>	public final U getRawResult() { return result.get(); }
5575	>	@SuppressWarnings("unchecked") public final void compute() {
5576	>	final Fun<? super K, ? extends U> searchFunction;
5577	>	final AtomicReference<U> result;
5578	>	if ((searchFunction = this.searchFunction) == null ||
5579	>	(result = this.result) == null)
5580	>	throw new NullPointerException();
5581	>	for (int b;;) {
5582	>	if (result.get() != null)
5583	>	return;
5584	>	if ((b = preSplit()) <= 0)
5585	>	break;
5586	>	new SearchKeysTask<K,V,U>
5587	>	(map, this, b, searchFunction, result).fork();
5588	>	}
5589	>	while (result.get() == null) {
5590	>	U u;
5591	>	if (advance() == null) {
5592	>	propagateCompletion();
5593	>	break;
5594	>	}
5595	>	if ((u = searchFunction.apply((K)nextKey)) != null) {
5596	>	if (result.compareAndSet(null, u))
5597	>	quietlyCompleteRoot();
5598	>	break;
5599	>	}
5600	>	}
5601	>	}
5602	>	}
5603	>
5604	>	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5605	>	extends Traverser<K,V,U> {
5606	>	final Fun<? super V, ? extends U> searchFunction;
5607	>	final AtomicReference<U> result;
5608	>	SearchValuesTask
5609	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5610	>	Fun<? super V, ? extends U> searchFunction,
5611	>	AtomicReference<U> result) {
5612	>	super(m, p, b);
5613	>	this.searchFunction = searchFunction; this.result = result;
5614	>	}
5615	>	public final U getRawResult() { return result.get(); }
5616	>	@SuppressWarnings("unchecked") public final void compute() {
5617	>	final Fun<? super V, ? extends U> searchFunction;
5618	>	final AtomicReference<U> result;
5619	>	if ((searchFunction = this.searchFunction) == null ||
5620	>	(result = this.result) == null)
5621	>	throw new NullPointerException();
5622	>	for (int b;;) {
5623	>	if (result.get() != null)
5624	>	return;
5625	>	if ((b = preSplit()) <= 0)
5626	>	break;
5627	>	new SearchValuesTask<K,V,U>
5628	>	(map, this, b, searchFunction, result).fork();
5629	>	}
5630	>	while (result.get() == null) {
5631	>	Object v; U u;
5632	>	if ((v = advance()) == null) {
5633	>	propagateCompletion();
5634	>	break;
5635	>	}
5636	>	if ((u = searchFunction.apply((V)v)) != null) {
5637	>	if (result.compareAndSet(null, u))
5638	>	quietlyCompleteRoot();
5639	>	break;
5640	>	}
5641	>	}
5642	>	}
5643	>	}
5644	>
5645	>	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5646	>	extends Traverser<K,V,U> {
5647	>	final Fun<Entry<K,V>, ? extends U> searchFunction;
5648	>	final AtomicReference<U> result;
5649	>	SearchEntriesTask
5650	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5651	>	Fun<Entry<K,V>, ? extends U> searchFunction,
5652	>	AtomicReference<U> result) {
5653	>	super(m, p, b);
5654	>	this.searchFunction = searchFunction; this.result = result;
5655	>	}
5656	>	public final U getRawResult() { return result.get(); }
5657	>	@SuppressWarnings("unchecked") public final void compute() {
5658	>	final Fun<Entry<K,V>, ? extends U> searchFunction;
5659	>	final AtomicReference<U> result;
5660	>	if ((searchFunction = this.searchFunction) == null ||
5661	>	(result = this.result) == null)
5662	>	throw new NullPointerException();
5663	>	for (int b;;) {
5664	>	if (result.get() != null)
5665	>	return;
5666	>	if ((b = preSplit()) <= 0)
5667	>	break;
5668	>	new SearchEntriesTask<K,V,U>
5669	>	(map, this, b, searchFunction, result).fork();
5670	>	}
5671	>	while (result.get() == null) {
5672	>	Object v; U u;
5673	>	if ((v = advance()) == null) {
5674	>	propagateCompletion();
5675	>	break;
5676	>	}
5677	>	if ((u = searchFunction.apply(entryFor((K)nextKey, (V)v))) != null) {
5678	>	if (result.compareAndSet(null, u))
5679	>	quietlyCompleteRoot();
5680	>	return;
5681	>	}
5682	>	}
5683	>	}
5684	>	}
5685	>
5686	>	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5687	>	extends Traverser<K,V,U> {
5688	>	final BiFun<? super K, ? super V, ? extends U> searchFunction;
5689	>	final AtomicReference<U> result;
5690	>	SearchMappingsTask
5691	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5692	>	BiFun<? super K, ? super V, ? extends U> searchFunction,
5693	>	AtomicReference<U> result) {
5694	>	super(m, p, b);
5695	>	this.searchFunction = searchFunction; this.result = result;
5696	>	}
5697	>	public final U getRawResult() { return result.get(); }
5698	>	@SuppressWarnings("unchecked") public final void compute() {
5699	>	final BiFun<? super K, ? super V, ? extends U> searchFunction;
5700	>	final AtomicReference<U> result;
5701	>	if ((searchFunction = this.searchFunction) == null ||
5702	>	(result = this.result) == null)
5703	>	throw new NullPointerException();
5704	>	for (int b;;) {
5705	>	if (result.get() != null)
5706	>	return;
5707	>	if ((b = preSplit()) <= 0)
5708	>	break;
5709	>	new SearchMappingsTask<K,V,U>
5710	>	(map, this, b, searchFunction, result).fork();
5711	>	}
5712	>	while (result.get() == null) {
5713	>	Object v; U u;
5714	>	if ((v = advance()) == null) {
5715	>	propagateCompletion();
5716	>	break;
5717	>	}
5718	>	if ((u = searchFunction.apply((K)nextKey, (V)v)) != null) {
5719	>	if (result.compareAndSet(null, u))
5720	>	quietlyCompleteRoot();
5721	>	break;
5722	>	}
5723	>	}
5724	>	}
5725	>	}
5726	>
5727	>	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5728	>	extends Traverser<K,V,K> {
5729	>	final BiFun<? super K, ? super K, ? extends K> reducer;
5730	>	K result;
5731	>	ReduceKeysTask<K,V> rights, nextRight;
5732	>	ReduceKeysTask
5733	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5734	>	ReduceKeysTask<K,V> nextRight,
5735	>	BiFun<? super K, ? super K, ? extends K> reducer) {
5736	>	super(m, p, b); this.nextRight = nextRight;
5737	>	this.reducer = reducer;
5738	>	}
5739	>	public final K getRawResult() { return result; }
5740	>	@SuppressWarnings("unchecked") public final void compute() {
5741	>	final BiFun<? super K, ? super K, ? extends K> reducer =
5742	>	this.reducer;
5743	>	if (reducer == null)
5744	>	throw new NullPointerException();
5745	>	for (int b; (b = preSplit()) > 0;)
5746	>	(rights = new ReduceKeysTask<K,V>
5747	>	(map, this, b, rights, reducer)).fork();
5748	>	K r = null;
5749	>	while (advance() != null) {
5750	>	K u = (K)nextKey;
5751	>	r = (r == null) ? u : reducer.apply(r, u);
5752	>	}
5753	>	result = r;
5754	>	CountedCompleter<?> c;
5755	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5756	>	ReduceKeysTask<K,V>
5757	>	t = (ReduceKeysTask<K,V>)c,
5758	>	s = t.rights;
5759	>	while (s != null) {
5760	>	K tr, sr;
5761	>	if ((sr = s.result) != null)
5762	>	t.result = (((tr = t.result) == null) ? sr :
5763	>	reducer.apply(tr, sr));
5764	>	s = t.rights = s.nextRight;
5765	>	}
5766	>	}
5767	>	}
5768	>	}
5769	>
5770	>	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
5771	>	extends Traverser<K,V,V> {
5772	>	final BiFun<? super V, ? super V, ? extends V> reducer;
5773	>	V result;
5774	>	ReduceValuesTask<K,V> rights, nextRight;
5775	>	ReduceValuesTask
5776	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5777	>	ReduceValuesTask<K,V> nextRight,
5778	>	BiFun<? super V, ? super V, ? extends V> reducer) {
5779	>	super(m, p, b); this.nextRight = nextRight;
5780	>	this.reducer = reducer;
5781	>	}
5782	>	public final V getRawResult() { return result; }
5783	>	@SuppressWarnings("unchecked") public final void compute() {
5784	>	final BiFun<? super V, ? super V, ? extends V> reducer =
5785	>	this.reducer;
5786	>	if (reducer == null)
5787	>	throw new NullPointerException();
5788	>	for (int b; (b = preSplit()) > 0;)
5789	>	(rights = new ReduceValuesTask<K,V>
5790	>	(map, this, b, rights, reducer)).fork();
5791	>	V r = null;
5792	>	Object v;
5793	>	while ((v = advance()) != null) {
5794	>	V u = (V)v;
5795	>	r = (r == null) ? u : reducer.apply(r, u);
5796	>	}
5797	>	result = r;
5798	>	CountedCompleter<?> c;
5799	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5800	>	ReduceValuesTask<K,V>
5801	>	t = (ReduceValuesTask<K,V>)c,
5802	>	s = t.rights;
5803	>	while (s != null) {
5804	>	V tr, sr;
5805	>	if ((sr = s.result) != null)
5806	>	t.result = (((tr = t.result) == null) ? sr :
5807	>	reducer.apply(tr, sr));
5808	>	s = t.rights = s.nextRight;
5809	>	}
5810	>	}
5811	>	}
5812	>	}
5813	>
5814	>	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
5815	>	extends Traverser<K,V,Map.Entry<K,V>> {
5816	>	final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5817	>	Map.Entry<K,V> result;
5818	>	ReduceEntriesTask<K,V> rights, nextRight;
5819	>	ReduceEntriesTask
5820	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5821	>	ReduceEntriesTask<K,V> nextRight,
5822	>	BiFun<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5823	>	super(m, p, b); this.nextRight = nextRight;
5824	>	this.reducer = reducer;
5825	>	}
5826	>	public final Map.Entry<K,V> getRawResult() { return result; }
5827	>	@SuppressWarnings("unchecked") public final void compute() {
5828	>	final BiFun<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer =
5829	>	this.reducer;
5830	>	if (reducer == null)
5831	>	throw new NullPointerException();
5832	>	for (int b; (b = preSplit()) > 0;)
5833	>	(rights = new ReduceEntriesTask<K,V>
5834	>	(map, this, b, rights, reducer)).fork();
5835	>	Map.Entry<K,V> r = null;
5836	>	Object v;
5837	>	while ((v = advance()) != null) {
5838	>	Map.Entry<K,V> u = entryFor((K)nextKey, (V)v);
5839	>	r = (r == null) ? u : reducer.apply(r, u);
5840	>	}
5841	>	result = r;
5842	>	CountedCompleter<?> c;
5843	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5844	>	ReduceEntriesTask<K,V>
5845	>	t = (ReduceEntriesTask<K,V>)c,
5846	>	s = t.rights;
5847	>	while (s != null) {
5848	>	Map.Entry<K,V> tr, sr;
5849	>	if ((sr = s.result) != null)
5850	>	t.result = (((tr = t.result) == null) ? sr :
5851	>	reducer.apply(tr, sr));
5852	>	s = t.rights = s.nextRight;
5853	>	}
5854	>	}
5855	>	}
5856	>	}
5857	>
5858	>	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
5859	>	extends Traverser<K,V,U> {
5860	>	final Fun<? super K, ? extends U> transformer;
5861	>	final BiFun<? super U, ? super U, ? extends U> reducer;
5862	>	U result;
5863	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5864	>	MapReduceKeysTask
5865	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5866	>	MapReduceKeysTask<K,V,U> nextRight,
5867	>	Fun<? super K, ? extends U> transformer,
5868	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5869	>	super(m, p, b); this.nextRight = nextRight;
5870	>	this.transformer = transformer;
5871	>	this.reducer = reducer;
5872	>	}
5873	>	public final U getRawResult() { return result; }
5874	>	@SuppressWarnings("unchecked") public final void compute() {
5875	>	final Fun<? super K, ? extends U> transformer =
5876	>	this.transformer;
5877	>	final BiFun<? super U, ? super U, ? extends U> reducer =
5878	>	this.reducer;
5879	>	if (transformer == null || reducer == null)
5880	>	throw new NullPointerException();
5881	>	for (int b; (b = preSplit()) > 0;)
5882	>	(rights = new MapReduceKeysTask<K,V,U>
5883	>	(map, this, b, rights, transformer, reducer)).fork();
5884	>	U r = null, u;
5885	>	while (advance() != null) {
5886	>	if ((u = transformer.apply((K)nextKey)) != null)
5887	>	r = (r == null) ? u : reducer.apply(r, u);
5888	>	}
5889	>	result = r;
5890	>	CountedCompleter<?> c;
5891	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5892	>	MapReduceKeysTask<K,V,U>
5893	>	t = (MapReduceKeysTask<K,V,U>)c,
5894	>	s = t.rights;
5895	>	while (s != null) {
5896	>	U tr, sr;
5897	>	if ((sr = s.result) != null)
5898	>	t.result = (((tr = t.result) == null) ? sr :
5899	>	reducer.apply(tr, sr));
5900	>	s = t.rights = s.nextRight;
5901	>	}
5902	>	}
5903	>	}
5904	>	}
5905	>
5906	>	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
5907	>	extends Traverser<K,V,U> {
5908	>	final Fun<? super V, ? extends U> transformer;
5909	>	final BiFun<? super U, ? super U, ? extends U> reducer;
5910	>	U result;
5911	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5912	>	MapReduceValuesTask
5913	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5914	>	MapReduceValuesTask<K,V,U> nextRight,
5915	>	Fun<? super V, ? extends U> transformer,
5916	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5917	>	super(m, p, b); this.nextRight = nextRight;
5918	>	this.transformer = transformer;
5919	>	this.reducer = reducer;
5920	>	}
5921	>	public final U getRawResult() { return result; }
5922	>	@SuppressWarnings("unchecked") public final void compute() {
5923	>	final Fun<? super V, ? extends U> transformer =
5924	>	this.transformer;
5925	>	final BiFun<? super U, ? super U, ? extends U> reducer =
5926	>	this.reducer;
5927	>	if (transformer == null || reducer == null)
5928	>	throw new NullPointerException();
5929	>	for (int b; (b = preSplit()) > 0;)
5930	>	(rights = new MapReduceValuesTask<K,V,U>
5931	>	(map, this, b, rights, transformer, reducer)).fork();
5932	>	U r = null, u;
5933	>	Object v;
5934	>	while ((v = advance()) != null) {
5935	>	if ((u = transformer.apply((V)v)) != null)
5936	>	r = (r == null) ? u : reducer.apply(r, u);
5937	>	}
5938	>	result = r;
5939	>	CountedCompleter<?> c;
5940	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5941	>	MapReduceValuesTask<K,V,U>
5942	>	t = (MapReduceValuesTask<K,V,U>)c,
5943	>	s = t.rights;
5944	>	while (s != null) {
5945	>	U tr, sr;
5946	>	if ((sr = s.result) != null)
5947	>	t.result = (((tr = t.result) == null) ? sr :
5948	>	reducer.apply(tr, sr));
5949	>	s = t.rights = s.nextRight;
5950	>	}
5951	>	}
5952	>	}
5953	>	}
5954	>
5955	>	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
5956	>	extends Traverser<K,V,U> {
5957	>	final Fun<Map.Entry<K,V>, ? extends U> transformer;
5958	>	final BiFun<? super U, ? super U, ? extends U> reducer;
5959	>	U result;
5960	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5961	>	MapReduceEntriesTask
5962	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5963	>	MapReduceEntriesTask<K,V,U> nextRight,
5964	>	Fun<Map.Entry<K,V>, ? extends U> transformer,
5965	>	BiFun<? super U, ? super U, ? extends U> reducer) {
5966	>	super(m, p, b); this.nextRight = nextRight;
5967	>	this.transformer = transformer;
5968	>	this.reducer = reducer;
5969	>	}
5970	>	public final U getRawResult() { return result; }
5971	>	@SuppressWarnings("unchecked") public final void compute() {
5972	>	final Fun<Map.Entry<K,V>, ? extends U> transformer =
5973	>	this.transformer;
5974	>	final BiFun<? super U, ? super U, ? extends U> reducer =
5975	>	this.reducer;
5976	>	if (transformer == null || reducer == null)
5977	>	throw new NullPointerException();
5978	>	for (int b; (b = preSplit()) > 0;)
5979	>	(rights = new MapReduceEntriesTask<K,V,U>
5980	>	(map, this, b, rights, transformer, reducer)).fork();
5981	>	U r = null, u;
5982	>	Object v;
5983	>	while ((v = advance()) != null) {
5984	>	if ((u = transformer.apply(entryFor((K)nextKey, (V)v))) != null)
5985	>	r = (r == null) ? u : reducer.apply(r, u);
5986	>	}
5987	>	result = r;
5988	>	CountedCompleter<?> c;
5989	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5990	>	MapReduceEntriesTask<K,V,U>
5991	>	t = (MapReduceEntriesTask<K,V,U>)c,
5992	>	s = t.rights;
5993	>	while (s != null) {
5994	>	U tr, sr;
5995	>	if ((sr = s.result) != null)
5996	>	t.result = (((tr = t.result) == null) ? sr :
5997	>	reducer.apply(tr, sr));
5998	>	s = t.rights = s.nextRight;
5999	>	}
6000	>	}
6001	>	}
6002	>	}
6003	>
6004	>	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6005	>	extends Traverser<K,V,U> {
6006	>	final BiFun<? super K, ? super V, ? extends U> transformer;
6007	>	final BiFun<? super U, ? super U, ? extends U> reducer;
6008	>	U result;
6009	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
6010	>	MapReduceMappingsTask
6011	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6012	>	MapReduceMappingsTask<K,V,U> nextRight,
6013	>	BiFun<? super K, ? super V, ? extends U> transformer,
6014	>	BiFun<? super U, ? super U, ? extends U> reducer) {
6015	>	super(m, p, b); this.nextRight = nextRight;
6016	>	this.transformer = transformer;
6017	>	this.reducer = reducer;
6018	>	}
6019	>	public final U getRawResult() { return result; }
6020	>	@SuppressWarnings("unchecked") public final void compute() {
6021	>	final BiFun<? super K, ? super V, ? extends U> transformer =
6022	>	this.transformer;
6023	>	final BiFun<? super U, ? super U, ? extends U> reducer =
6024	>	this.reducer;
6025	>	if (transformer == null || reducer == null)
6026	>	throw new NullPointerException();
6027	>	for (int b; (b = preSplit()) > 0;)
6028	>	(rights = new MapReduceMappingsTask<K,V,U>
6029	>	(map, this, b, rights, transformer, reducer)).fork();
6030	>	U r = null, u;
6031	>	Object v;
6032	>	while ((v = advance()) != null) {
6033	>	if ((u = transformer.apply((K)nextKey, (V)v)) != null)
6034	>	r = (r == null) ? u : reducer.apply(r, u);
6035	>	}
6036	>	result = r;
6037	>	CountedCompleter<?> c;
6038	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6039	>	MapReduceMappingsTask<K,V,U>
6040	>	t = (MapReduceMappingsTask<K,V,U>)c,
6041	>	s = t.rights;
6042	>	while (s != null) {
6043	>	U tr, sr;
6044	>	if ((sr = s.result) != null)
6045	>	t.result = (((tr = t.result) == null) ? sr :
6046	>	reducer.apply(tr, sr));
6047	>	s = t.rights = s.nextRight;
6048	>	}
6049	>	}
6050	>	}
6051	>	}
6052	>
6053	>	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6054	>	extends Traverser<K,V,Double> {
6055	>	final ObjectToDouble<? super K> transformer;
6056	>	final DoubleByDoubleToDouble reducer;
6057	>	final double basis;
6058	>	double result;
6059	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6060	>	MapReduceKeysToDoubleTask
6061	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6062	>	MapReduceKeysToDoubleTask<K,V> nextRight,
6063	>	ObjectToDouble<? super K> transformer,
6064	>	double basis,
6065	>	DoubleByDoubleToDouble reducer) {
6066	>	super(m, p, b); this.nextRight = nextRight;
6067	>	this.transformer = transformer;
6068	>	this.basis = basis; this.reducer = reducer;
6069	>	}
6070	>	public final Double getRawResult() { return result; }
6071	>	@SuppressWarnings("unchecked") public final void compute() {
6072	>	final ObjectToDouble<? super K> transformer =
6073	>	this.transformer;
6074	>	final DoubleByDoubleToDouble reducer = this.reducer;
6075	>	if (transformer == null || reducer == null)
6076	>	throw new NullPointerException();
6077	>	double r = this.basis;
6078	>	for (int b; (b = preSplit()) > 0;)
6079	>	(rights = new MapReduceKeysToDoubleTask<K,V>
6080	>	(map, this, b, rights, transformer, r, reducer)).fork();
6081	>	while (advance() != null)
6082	>	r = reducer.apply(r, transformer.apply((K)nextKey));
6083	>	result = r;
6084	>	CountedCompleter<?> c;
6085	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6086	>	MapReduceKeysToDoubleTask<K,V>
6087	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
6088	>	s = t.rights;
6089	>	while (s != null) {
6090	>	t.result = reducer.apply(t.result, s.result);
6091	>	s = t.rights = s.nextRight;
6092	>	}
6093	>	}
6094	>	}
6095	>	}
6096	>
6097	>	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6098	>	extends Traverser<K,V,Double> {
6099	>	final ObjectToDouble<? super V> transformer;
6100	>	final DoubleByDoubleToDouble reducer;
6101	>	final double basis;
6102	>	double result;
6103	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6104	>	MapReduceValuesToDoubleTask
6105	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6106	>	MapReduceValuesToDoubleTask<K,V> nextRight,
6107	>	ObjectToDouble<? super V> transformer,
6108	>	double basis,
6109	>	DoubleByDoubleToDouble reducer) {
6110	>	super(m, p, b); this.nextRight = nextRight;
6111	>	this.transformer = transformer;
6112	>	this.basis = basis; this.reducer = reducer;
6113	>	}
6114	>	public final Double getRawResult() { return result; }
6115	>	@SuppressWarnings("unchecked") public final void compute() {
6116	>	final ObjectToDouble<? super V> transformer =
6117	>	this.transformer;
6118	>	final DoubleByDoubleToDouble reducer = this.reducer;
6119	>	if (transformer == null || reducer == null)
6120	>	throw new NullPointerException();
6121	>	double r = this.basis;
6122	>	for (int b; (b = preSplit()) > 0;)
6123	>	(rights = new MapReduceValuesToDoubleTask<K,V>
6124	>	(map, this, b, rights, transformer, r, reducer)).fork();
6125	>	Object v;
6126	>	while ((v = advance()) != null)
6127	>	r = reducer.apply(r, transformer.apply((V)v));
6128	>	result = r;
6129	>	CountedCompleter<?> c;
6130	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6131	>	MapReduceValuesToDoubleTask<K,V>
6132	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
6133	>	s = t.rights;
6134	>	while (s != null) {
6135	>	t.result = reducer.apply(t.result, s.result);
6136	>	s = t.rights = s.nextRight;
6137	>	}
6138	>	}
6139	>	}
6140	>	}
6141	>
6142	>	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6143	>	extends Traverser<K,V,Double> {
6144	>	final ObjectToDouble<Map.Entry<K,V>> transformer;
6145	>	final DoubleByDoubleToDouble reducer;
6146	>	final double basis;
6147	>	double result;
6148	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6149	>	MapReduceEntriesToDoubleTask
6150	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6151	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
6152	>	ObjectToDouble<Map.Entry<K,V>> transformer,
6153	>	double basis,
6154	>	DoubleByDoubleToDouble reducer) {
6155	>	super(m, p, b); this.nextRight = nextRight;
6156	>	this.transformer = transformer;
6157	>	this.basis = basis; this.reducer = reducer;
6158	>	}
6159	>	public final Double getRawResult() { return result; }
6160	>	@SuppressWarnings("unchecked") public final void compute() {
6161	>	final ObjectToDouble<Map.Entry<K,V>> transformer =
6162	>	this.transformer;
6163	>	final DoubleByDoubleToDouble reducer = this.reducer;
6164	>	if (transformer == null || reducer == null)
6165	>	throw new NullPointerException();
6166	>	double r = this.basis;
6167	>	for (int b; (b = preSplit()) > 0;)
6168	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
6169	>	(map, this, b, rights, transformer, r, reducer)).fork();
6170	>	Object v;
6171	>	while ((v = advance()) != null)
6172	>	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6173	>	result = r;
6174	>	CountedCompleter<?> c;
6175	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6176	>	MapReduceEntriesToDoubleTask<K,V>
6177	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
6178	>	s = t.rights;
6179	>	while (s != null) {
6180	>	t.result = reducer.apply(t.result, s.result);
6181	>	s = t.rights = s.nextRight;
6182	>	}
6183	>	}
6184	>	}
6185	>	}
6186	>
6187	>	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6188	>	extends Traverser<K,V,Double> {
6189	>	final ObjectByObjectToDouble<? super K, ? super V> transformer;
6190	>	final DoubleByDoubleToDouble reducer;
6191	>	final double basis;
6192	>	double result;
6193	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6194	>	MapReduceMappingsToDoubleTask
6195	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6196	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
6197	>	ObjectByObjectToDouble<? super K, ? super V> transformer,
6198	>	double basis,
6199	>	DoubleByDoubleToDouble reducer) {
6200	>	super(m, p, b); this.nextRight = nextRight;
6201	>	this.transformer = transformer;
6202	>	this.basis = basis; this.reducer = reducer;
6203	>	}
6204	>	public final Double getRawResult() { return result; }
6205	>	@SuppressWarnings("unchecked") public final void compute() {
6206	>	final ObjectByObjectToDouble<? super K, ? super V> transformer =
6207	>	this.transformer;
6208	>	final DoubleByDoubleToDouble reducer = this.reducer;
6209	>	if (transformer == null || reducer == null)
6210	>	throw new NullPointerException();
6211	>	double r = this.basis;
6212	>	for (int b; (b = preSplit()) > 0;)
6213	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
6214	>	(map, this, b, rights, transformer, r, reducer)).fork();
6215	>	Object v;
6216	>	while ((v = advance()) != null)
6217	>	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6218	>	result = r;
6219	>	CountedCompleter<?> c;
6220	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6221	>	MapReduceMappingsToDoubleTask<K,V>
6222	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
6223	>	s = t.rights;
6224	>	while (s != null) {
6225	>	t.result = reducer.apply(t.result, s.result);
6226	>	s = t.rights = s.nextRight;
6227	>	}
6228	>	}
6229	>	}
6230	>	}
6231	>
6232	>	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6233	>	extends Traverser<K,V,Long> {
6234	>	final ObjectToLong<? super K> transformer;
6235	>	final LongByLongToLong reducer;
6236	>	final long basis;
6237	>	long result;
6238	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
6239	>	MapReduceKeysToLongTask
6240	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6241	>	MapReduceKeysToLongTask<K,V> nextRight,
6242	>	ObjectToLong<? super K> transformer,
6243	>	long basis,
6244	>	LongByLongToLong reducer) {
6245	>	super(m, p, b); this.nextRight = nextRight;
6246	>	this.transformer = transformer;
6247	>	this.basis = basis; this.reducer = reducer;
6248	>	}
6249	>	public final Long getRawResult() { return result; }
6250	>	@SuppressWarnings("unchecked") public final void compute() {
6251	>	final ObjectToLong<? super K> transformer =
6252	>	this.transformer;
6253	>	final LongByLongToLong reducer = this.reducer;
6254	>	if (transformer == null || reducer == null)
6255	>	throw new NullPointerException();
6256	>	long r = this.basis;
6257	>	for (int b; (b = preSplit()) > 0;)
6258	>	(rights = new MapReduceKeysToLongTask<K,V>
6259	>	(map, this, b, rights, transformer, r, reducer)).fork();
6260	>	while (advance() != null)
6261	>	r = reducer.apply(r, transformer.apply((K)nextKey));
6262	>	result = r;
6263	>	CountedCompleter<?> c;
6264	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6265	>	MapReduceKeysToLongTask<K,V>
6266	>	t = (MapReduceKeysToLongTask<K,V>)c,
6267	>	s = t.rights;
6268	>	while (s != null) {
6269	>	t.result = reducer.apply(t.result, s.result);
6270	>	s = t.rights = s.nextRight;
6271	>	}
6272	>	}
6273		}
6274		}
1132	–	}
6275
6276	+	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6277	+	extends Traverser<K,V,Long> {
6278	+	final ObjectToLong<? super V> transformer;
6279	+	final LongByLongToLong reducer;
6280	+	final long basis;
6281	+	long result;
6282	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
6283	+	MapReduceValuesToLongTask
6284	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6285	+	MapReduceValuesToLongTask<K,V> nextRight,
6286	+	ObjectToLong<? super V> transformer,
6287	+	long basis,
6288	+	LongByLongToLong reducer) {
6289	+	super(m, p, b); this.nextRight = nextRight;
6290	+	this.transformer = transformer;
6291	+	this.basis = basis; this.reducer = reducer;
6292	+	}
6293	+	public final Long getRawResult() { return result; }
6294	+	@SuppressWarnings("unchecked") public final void compute() {
6295	+	final ObjectToLong<? super V> transformer =
6296	+	this.transformer;
6297	+	final LongByLongToLong reducer = this.reducer;
6298	+	if (transformer == null || reducer == null)
6299	+	throw new NullPointerException();
6300	+	long r = this.basis;
6301	+	for (int b; (b = preSplit()) > 0;)
6302	+	(rights = new MapReduceValuesToLongTask<K,V>
6303	+	(map, this, b, rights, transformer, r, reducer)).fork();
6304	+	Object v;
6305	+	while ((v = advance()) != null)
6306	+	r = reducer.apply(r, transformer.apply((V)v));
6307	+	result = r;
6308	+	CountedCompleter<?> c;
6309	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6310	+	MapReduceValuesToLongTask<K,V>
6311	+	t = (MapReduceValuesToLongTask<K,V>)c,
6312	+	s = t.rights;
6313	+	while (s != null) {
6314	+	t.result = reducer.apply(t.result, s.result);
6315	+	s = t.rights = s.nextRight;
6316	+	}
6317	+	}
6318	+	}
6319	+	}
6320	+
6321	+	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6322	+	extends Traverser<K,V,Long> {
6323	+	final ObjectToLong<Map.Entry<K,V>> transformer;
6324	+	final LongByLongToLong reducer;
6325	+	final long basis;
6326	+	long result;
6327	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6328	+	MapReduceEntriesToLongTask
6329	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6330	+	MapReduceEntriesToLongTask<K,V> nextRight,
6331	+	ObjectToLong<Map.Entry<K,V>> transformer,
6332	+	long basis,
6333	+	LongByLongToLong reducer) {
6334	+	super(m, p, b); this.nextRight = nextRight;
6335	+	this.transformer = transformer;
6336	+	this.basis = basis; this.reducer = reducer;
6337	+	}
6338	+	public final Long getRawResult() { return result; }
6339	+	@SuppressWarnings("unchecked") public final void compute() {
6340	+	final ObjectToLong<Map.Entry<K,V>> transformer =
6341	+	this.transformer;
6342	+	final LongByLongToLong reducer = this.reducer;
6343	+	if (transformer == null || reducer == null)
6344	+	throw new NullPointerException();
6345	+	long r = this.basis;
6346	+	for (int b; (b = preSplit()) > 0;)
6347	+	(rights = new MapReduceEntriesToLongTask<K,V>
6348	+	(map, this, b, rights, transformer, r, reducer)).fork();
6349	+	Object v;
6350	+	while ((v = advance()) != null)
6351	+	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6352	+	result = r;
6353	+	CountedCompleter<?> c;
6354	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6355	+	MapReduceEntriesToLongTask<K,V>
6356	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6357	+	s = t.rights;
6358	+	while (s != null) {
6359	+	t.result = reducer.apply(t.result, s.result);
6360	+	s = t.rights = s.nextRight;
6361	+	}
6362	+	}
6363	+	}
6364	+	}
6365	+
6366	+	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6367	+	extends Traverser<K,V,Long> {
6368	+	final ObjectByObjectToLong<? super K, ? super V> transformer;
6369	+	final LongByLongToLong reducer;
6370	+	final long basis;
6371	+	long result;
6372	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6373	+	MapReduceMappingsToLongTask
6374	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6375	+	MapReduceMappingsToLongTask<K,V> nextRight,
6376	+	ObjectByObjectToLong<? super K, ? super V> transformer,
6377	+	long basis,
6378	+	LongByLongToLong reducer) {
6379	+	super(m, p, b); this.nextRight = nextRight;
6380	+	this.transformer = transformer;
6381	+	this.basis = basis; this.reducer = reducer;
6382	+	}
6383	+	public final Long getRawResult() { return result; }
6384	+	@SuppressWarnings("unchecked") public final void compute() {
6385	+	final ObjectByObjectToLong<? super K, ? super V> transformer =
6386	+	this.transformer;
6387	+	final LongByLongToLong reducer = this.reducer;
6388	+	if (transformer == null || reducer == null)
6389	+	throw new NullPointerException();
6390	+	long r = this.basis;
6391	+	for (int b; (b = preSplit()) > 0;)
6392	+	(rights = new MapReduceMappingsToLongTask<K,V>
6393	+	(map, this, b, rights, transformer, r, reducer)).fork();
6394	+	Object v;
6395	+	while ((v = advance()) != null)
6396	+	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6397	+	result = r;
6398	+	CountedCompleter<?> c;
6399	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6400	+	MapReduceMappingsToLongTask<K,V>
6401	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6402	+	s = t.rights;
6403	+	while (s != null) {
6404	+	t.result = reducer.apply(t.result, s.result);
6405	+	s = t.rights = s.nextRight;
6406	+	}
6407	+	}
6408	+	}
6409	+	}
6410	+
6411	+	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6412	+	extends Traverser<K,V,Integer> {
6413	+	final ObjectToInt<? super K> transformer;
6414	+	final IntByIntToInt reducer;
6415	+	final int basis;
6416	+	int result;
6417	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6418	+	MapReduceKeysToIntTask
6419	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6420	+	MapReduceKeysToIntTask<K,V> nextRight,
6421	+	ObjectToInt<? super K> transformer,
6422	+	int basis,
6423	+	IntByIntToInt reducer) {
6424	+	super(m, p, b); this.nextRight = nextRight;
6425	+	this.transformer = transformer;
6426	+	this.basis = basis; this.reducer = reducer;
6427	+	}
6428	+	public final Integer getRawResult() { return result; }
6429	+	@SuppressWarnings("unchecked") public final void compute() {
6430	+	final ObjectToInt<? super K> transformer =
6431	+	this.transformer;
6432	+	final IntByIntToInt reducer = this.reducer;
6433	+	if (transformer == null || reducer == null)
6434	+	throw new NullPointerException();
6435	+	int r = this.basis;
6436	+	for (int b; (b = preSplit()) > 0;)
6437	+	(rights = new MapReduceKeysToIntTask<K,V>
6438	+	(map, this, b, rights, transformer, r, reducer)).fork();
6439	+	while (advance() != null)
6440	+	r = reducer.apply(r, transformer.apply((K)nextKey));
6441	+	result = r;
6442	+	CountedCompleter<?> c;
6443	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6444	+	MapReduceKeysToIntTask<K,V>
6445	+	t = (MapReduceKeysToIntTask<K,V>)c,
6446	+	s = t.rights;
6447	+	while (s != null) {
6448	+	t.result = reducer.apply(t.result, s.result);
6449	+	s = t.rights = s.nextRight;
6450	+	}
6451	+	}
6452	+	}
6453	+	}
6454	+
6455	+	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6456	+	extends Traverser<K,V,Integer> {
6457	+	final ObjectToInt<? super V> transformer;
6458	+	final IntByIntToInt reducer;
6459	+	final int basis;
6460	+	int result;
6461	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6462	+	MapReduceValuesToIntTask
6463	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6464	+	MapReduceValuesToIntTask<K,V> nextRight,
6465	+	ObjectToInt<? super V> transformer,
6466	+	int basis,
6467	+	IntByIntToInt reducer) {
6468	+	super(m, p, b); this.nextRight = nextRight;
6469	+	this.transformer = transformer;
6470	+	this.basis = basis; this.reducer = reducer;
6471	+	}
6472	+	public final Integer getRawResult() { return result; }
6473	+	@SuppressWarnings("unchecked") public final void compute() {
6474	+	final ObjectToInt<? super V> transformer =
6475	+	this.transformer;
6476	+	final IntByIntToInt reducer = this.reducer;
6477	+	if (transformer == null || reducer == null)
6478	+	throw new NullPointerException();
6479	+	int r = this.basis;
6480	+	for (int b; (b = preSplit()) > 0;)
6481	+	(rights = new MapReduceValuesToIntTask<K,V>
6482	+	(map, this, b, rights, transformer, r, reducer)).fork();
6483	+	Object v;
6484	+	while ((v = advance()) != null)
6485	+	r = reducer.apply(r, transformer.apply((V)v));
6486	+	result = r;
6487	+	CountedCompleter<?> c;
6488	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6489	+	MapReduceValuesToIntTask<K,V>
6490	+	t = (MapReduceValuesToIntTask<K,V>)c,
6491	+	s = t.rights;
6492	+	while (s != null) {
6493	+	t.result = reducer.apply(t.result, s.result);
6494	+	s = t.rights = s.nextRight;
6495	+	}
6496	+	}
6497	+	}
6498	+	}
6499	+
6500	+	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6501	+	extends Traverser<K,V,Integer> {
6502	+	final ObjectToInt<Map.Entry<K,V>> transformer;
6503	+	final IntByIntToInt reducer;
6504	+	final int basis;
6505	+	int result;
6506	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6507	+	MapReduceEntriesToIntTask
6508	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6509	+	MapReduceEntriesToIntTask<K,V> nextRight,
6510	+	ObjectToInt<Map.Entry<K,V>> transformer,
6511	+	int basis,
6512	+	IntByIntToInt reducer) {
6513	+	super(m, p, b); this.nextRight = nextRight;
6514	+	this.transformer = transformer;
6515	+	this.basis = basis; this.reducer = reducer;
6516	+	}
6517	+	public final Integer getRawResult() { return result; }
6518	+	@SuppressWarnings("unchecked") public final void compute() {
6519	+	final ObjectToInt<Map.Entry<K,V>> transformer =
6520	+	this.transformer;
6521	+	final IntByIntToInt reducer = this.reducer;
6522	+	if (transformer == null || reducer == null)
6523	+	throw new NullPointerException();
6524	+	int r = this.basis;
6525	+	for (int b; (b = preSplit()) > 0;)
6526	+	(rights = new MapReduceEntriesToIntTask<K,V>
6527	+	(map, this, b, rights, transformer, r, reducer)).fork();
6528	+	Object v;
6529	+	while ((v = advance()) != null)
6530	+	r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, (V)v)));
6531	+	result = r;
6532	+	CountedCompleter<?> c;
6533	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6534	+	MapReduceEntriesToIntTask<K,V>
6535	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6536	+	s = t.rights;
6537	+	while (s != null) {
6538	+	t.result = reducer.apply(t.result, s.result);
6539	+	s = t.rights = s.nextRight;
6540	+	}
6541	+	}
6542	+	}
6543	+	}
6544	+
6545	+	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6546	+	extends Traverser<K,V,Integer> {
6547	+	final ObjectByObjectToInt<? super K, ? super V> transformer;
6548	+	final IntByIntToInt reducer;
6549	+	final int basis;
6550	+	int result;
6551	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6552	+	MapReduceMappingsToIntTask
6553	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6554	+	MapReduceMappingsToIntTask<K,V> nextRight,
6555	+	ObjectByObjectToInt<? super K, ? super V> transformer,
6556	+	int basis,
6557	+	IntByIntToInt reducer) {
6558	+	super(m, p, b); this.nextRight = nextRight;
6559	+	this.transformer = transformer;
6560	+	this.basis = basis; this.reducer = reducer;
6561	+	}
6562	+	public final Integer getRawResult() { return result; }
6563	+	@SuppressWarnings("unchecked") public final void compute() {
6564	+	final ObjectByObjectToInt<? super K, ? super V> transformer =
6565	+	this.transformer;
6566	+	final IntByIntToInt reducer = this.reducer;
6567	+	if (transformer == null || reducer == null)
6568	+	throw new NullPointerException();
6569	+	int r = this.basis;
6570	+	for (int b; (b = preSplit()) > 0;)
6571	+	(rights = new MapReduceMappingsToIntTask<K,V>
6572	+	(map, this, b, rights, transformer, r, reducer)).fork();
6573	+	Object v;
6574	+	while ((v = advance()) != null)
6575	+	r = reducer.apply(r, transformer.apply((K)nextKey, (V)v));
6576	+	result = r;
6577	+	CountedCompleter<?> c;
6578	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6579	+	MapReduceMappingsToIntTask<K,V>
6580	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6581	+	s = t.rights;
6582	+	while (s != null) {
6583	+	t.result = reducer.apply(t.result, s.result);
6584	+	s = t.rights = s.nextRight;
6585	+	}
6586	+	}
6587	+	}
6588	+	}
6589	+
6590	+
6591	+	// Unsafe mechanics
6592	+	private static final sun.misc.Unsafe UNSAFE;
6593	+	private static final long counterOffset;
6594	+	private static final long sizeCtlOffset;
6595	+	private static final long ABASE;
6596	+	private static final int ASHIFT;
6597	+
6598	+	static {
6599	+	int ss;
6600	+	try {
6601	+	UNSAFE = sun.misc.Unsafe.getUnsafe();
6602	+	Class<?> k = ConcurrentHashMap.class;
6603	+	counterOffset = UNSAFE.objectFieldOffset
6604	+	(k.getDeclaredField("counter"));
6605	+	sizeCtlOffset = UNSAFE.objectFieldOffset
6606	+	(k.getDeclaredField("sizeCtl"));
6607	+	Class<?> sc = Node[].class;
6608	+	ABASE = UNSAFE.arrayBaseOffset(sc);
6609	+	ss = UNSAFE.arrayIndexScale(sc);
6610	+	} catch (Exception e) {
6611	+	throw new Error(e);
6612	+	}
6613	+	if ((ss & (ss-1)) != 0)
6614	+	throw new Error("data type scale not a power of two");
6615	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(ss);
6616	+	}
6617	+	}

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