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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.92 by dl, Sat Dec 2 20:55:01 2006 UTC vs.
Revision 1.175 by jsr166, Mon Feb 11 08:37:44 2013 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>	import java.util.concurrent.ForkJoinPool;
9	>	import java.util.concurrent.CountedCompleter;
10	>	import java.util.function.*;
11	>	import java.util.Spliterator;
12	>	import java.util.stream.Stream;
13	>	import java.util.stream.Streams;
14	>
15	>	import java.util.Comparator;
16	>	import java.util.Arrays;
17	>	import java.util.Map;
18	>	import java.util.Set;
19	>	import java.util.Collection;
20	>	import java.util.AbstractMap;
21	>	import java.util.AbstractSet;
22	>	import java.util.AbstractCollection;
23	>	import java.util.Hashtable;
24	>	import java.util.HashMap;
25	>	import java.util.Iterator;
26	>	import java.util.Enumeration;
27	>	import java.util.ConcurrentModificationException;
28	>	import java.util.NoSuchElementException;
29	>	import java.util.concurrent.ConcurrentMap;
30	>	import java.util.concurrent.locks.AbstractQueuedSynchronizer;
31	>	import java.util.concurrent.atomic.AtomicInteger;
32	>	import java.util.concurrent.atomic.AtomicReference;
33		import java.io.Serializable;
11	–	import java.io.IOException;
12	–	import java.io.ObjectInputStream;
13	–	import java.io.ObjectOutputStream;
34
35		/**
36		* A hash table supporting full concurrency of retrievals and
37	<	* adjustable expected concurrency for updates. This class obeys the
37	>	* high expected concurrency for updates. This class obeys the
38		* same functional specification as {@link java.util.Hashtable}, and
39		* includes versions of methods corresponding to each method of
40	<	* <tt>Hashtable</tt>. However, even though all operations are
40	>	* {@code Hashtable}. However, even though all operations are
41		* thread-safe, retrieval operations do <em>not</em> entail locking,
42		* and there is <em>not</em> any support for locking the entire table
43		* in a way that prevents all access.  This class is fully
44	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
44	>	* interoperable with {@code Hashtable} in programs that rely on its
45		* thread safety but not on its synchronization details.
46		*
47	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
48	<	* block, so may overlap with update operations (including
49	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
50	<	* of the most recently <em>completed</em> update operations holding
51	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
52	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
53	<	* removal of only some entries.  Similarly, Iterators and
54	<	* Enumerations return elements reflecting the state of the hash table
55	<	* at some point at or since the creation of the iterator/enumeration.
56	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
57	<	* However, iterators are designed to be used by only one thread at a time.
58	<	*
59	<	* <p> The allowed concurrency among update operations is guided by
60	<	* the optional <tt>concurrencyLevel</tt> constructor argument
61	<	* (default <tt>16</tt>), 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 modify 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. A value of one is
71	<	* appropriate when it is known that only one thread will modify and
72	<	* all others will only read. Also, resizing this or any other kind of
73	<	* hash table is a relatively slow operation, so, when possible, it is
74	<	* a good idea to provide estimates of expected table sizes in
75	<	* constructors.
47	>	* <p>Retrieval operations (including {@code get}) generally do not
48	>	* block, so may overlap with update operations (including {@code put}
49	>	* and {@code remove}). Retrievals reflect the results of the most
50	>	* recently <em>completed</em> update operations holding upon their
51	>	* onset. (More formally, an update operation for a given key bears a
52	>	* <em>happens-before</em> relation with any (non-null) retrieval for
53	>	* that key reporting the updated value.)  For aggregate operations
54	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
55	>	* reflect insertion or removal of only some entries.  Similarly,
56	>	* Iterators and Enumerations return elements reflecting the state of
57	>	* the hash table at some point at or since the creation of the
58	>	* iterator/enumeration.  They do <em>not</em> throw {@link
59	>	* ConcurrentModificationException}.  However, iterators are designed
60	>	* to be used by only one thread at a time.  Bear in mind that the
61	>	* results of aggregate status methods including {@code size}, {@code
62	>	* isEmpty}, and {@code containsValue} are typically useful only when
63	>	* a map is not undergoing concurrent updates in other threads.
64	>	* Otherwise the results of these methods reflect transient states
65	>	* that may be adequate for monitoring or estimation purposes, but not
66	>	* for program control.
67	>	*
68	>	* <p>The table is dynamically expanded when there are too many
69	>	* collisions (i.e., keys that have distinct hash codes but fall into
70	>	* the same slot modulo the table size), with the expected average
71	>	* effect of maintaining roughly two bins per mapping (corresponding
72	>	* to a 0.75 load factor threshold for resizing). There may be much
73	>	* variance around this average as mappings are added and removed, but
74	>	* overall, this maintains a commonly accepted time/space tradeoff for
75	>	* hash tables.  However, resizing this or any other kind of hash
76	>	* table may be a relatively slow operation. When possible, it is a
77	>	* good idea to provide a size estimate as an optional {@code
78	>	* initialCapacity} constructor argument. An additional optional
79	>	* {@code loadFactor} constructor argument provides a further means of
80	>	* customizing initial table capacity by specifying the table density
81	>	* to be used in calculating the amount of space to allocate for the
82	>	* given number of elements.  Also, for compatibility with previous
83	>	* versions of this class, constructors may optionally specify an
84	>	* expected {@code concurrencyLevel} as an additional hint for
85	>	* internal sizing.  Note that using many keys with exactly the same
86	>	* {@code hashCode()} is a sure way to slow down performance of any
87	>	* hash table.
88	>	*
89	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
90	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
91	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
92	>	* mapped values are (perhaps transiently) not used or all take the
93	>	* same mapping value.
94	>	*
95	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
96	>	* form of histogram or multiset) by using {@link
97	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
98	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
99	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
100	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
101		*
102		* <p>This class and its views and iterators implement all of the
103		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
104		* interfaces.
105		*
106	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
107	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
106	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
107	>	* does <em>not</em> allow {@code null} to be used as a key or value.
108	>	*
109	>	* <p>ConcurrentHashMaps support sequential and parallel operations
110	>	* bulk operations. (Parallel forms use the {@link
111	>	* ForkJoinPool#commonPool()}). Tasks that may be used in other
112	>	* contexts are available in class {@link ForkJoinTasks}. These
113	>	* operations are designed to be safely, and often sensibly, applied
114	>	* even with maps that are being concurrently updated by other
115	>	* threads; for example, when computing a snapshot summary of the
116	>	* values in a shared registry.  There are three kinds of operation,
117	>	* each with four forms, accepting functions with Keys, Values,
118	>	* Entries, and (Key, Value) arguments and/or return values. Because
119	>	* the elements of a ConcurrentHashMap are not ordered in any
120	>	* particular way, and may be processed in different orders in
121	>	* different parallel executions, the correctness of supplied
122	>	* functions should not depend on any ordering, or on any other
123	>	* objects or values that may transiently change while computation is
124	>	* in progress; and except for forEach actions, should ideally be
125	>	* side-effect-free.
126	>	*
127	>	* <ul>
128	>	* <li> forEach: Perform a given action on each element.
129	>	* A variant form applies a given transformation on each element
130	>	* before performing the action.</li>
131	>	*
132	>	* <li> search: Return the first available non-null result of
133	>	* applying a given function on each element; skipping further
134	>	* search when a result is found.</li>
135	>	*
136	>	* <li> reduce: Accumulate each element.  The supplied reduction
137	>	* function cannot rely on ordering (more formally, it should be
138	>	* both associative and commutative).  There are five variants:
139	>	*
140	>	* <ul>
141	>	*
142	>	* <li> Plain reductions. (There is not a form of this method for
143	>	* (key, value) function arguments since there is no corresponding
144	>	* return type.)</li>
145	>	*
146	>	* <li> Mapped reductions that accumulate the results of a given
147	>	* function applied to each element.</li>
148	>	*
149	>	* <li> Reductions to scalar doubles, longs, and ints, using a
150	>	* given basis value.</li>
151	>	*
152	>	* </li>
153	>	* </ul>
154	>	* </ul>
155	>	*
156	>	* <p>The concurrency properties of bulk operations follow
157	>	* from those of ConcurrentHashMap: Any non-null result returned
158	>	* from {@code get(key)} and related access methods bears a
159	>	* happens-before relation with the associated insertion or
160	>	* update.  The result of any bulk operation reflects the
161	>	* composition of these per-element relations (but is not
162	>	* necessarily atomic with respect to the map as a whole unless it
163	>	* is somehow known to be quiescent).  Conversely, because keys
164	>	* and values in the map are never null, null serves as a reliable
165	>	* atomic indicator of the current lack of any result.  To
166	>	* maintain this property, null serves as an implicit basis for
167	>	* all non-scalar reduction operations. For the double, long, and
168	>	* int versions, the basis should be one that, when combined with
169	>	* any other value, returns that other value (more formally, it
170	>	* should be the identity element for the reduction). Most common
171	>	* reductions have these properties; for example, computing a sum
172	>	* with basis 0 or a minimum with basis MAX_VALUE.
173	>	*
174	>	* <p>Search and transformation functions provided as arguments
175	>	* should similarly return null to indicate the lack of any result
176	>	* (in which case it is not used). In the case of mapped
177	>	* reductions, this also enables transformations to serve as
178	>	* filters, returning null (or, in the case of primitive
179	>	* specializations, the identity basis) if the element should not
180	>	* be combined. You can create compound transformations and
181	>	* filterings by composing them yourself under this "null means
182	>	* there is nothing there now" rule before using them in search or
183	>	* reduce operations.
184	>	*
185	>	* <p>Methods accepting and/or returning Entry arguments maintain
186	>	* key-value associations. They may be useful for example when
187	>	* finding the key for the greatest value. Note that "plain" Entry
188	>	* arguments can be supplied using {@code new
189	>	* AbstractMap.SimpleEntry(k,v)}.
190	>	*
191	>	* <p>Bulk operations may complete abruptly, throwing an
192	>	* exception encountered in the application of a supplied
193	>	* function. Bear in mind when handling such exceptions that other
194	>	* concurrently executing functions could also have thrown
195	>	* exceptions, or would have done so if the first exception had
196	>	* not occurred.
197	>	*
198	>	* <p>Speedups for parallel compared to sequential forms are common
199	>	* but not guaranteed.  Parallel operations involving brief functions
200	>	* on small maps may execute more slowly than sequential forms if the
201	>	* underlying work to parallelize the computation is more expensive
202	>	* than the computation itself.  Similarly, parallelization may not
203	>	* lead to much actual parallelism if all processors are busy
204	>	* performing unrelated tasks.
205	>	*
206	>	* <p>All arguments to all task methods must be non-null.
207		*
208		* <p>This class is a member of the
209		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 214 | import java.io.ObjectOutputStream;
214		* @param <K> the type of keys maintained by this map
215		* @param <V> the type of mapped values
216		*/
217	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
218	<	implements ConcurrentMap<K, V>, Serializable {
217	>	public class ConcurrentHashMap<K, V>
218	>	implements ConcurrentMap<K, V>, Serializable {
219		private static final long serialVersionUID = 7249069246763182397L;
220
221		/*
222	<	* The basic strategy is to subdivide the table among Segments,
223	<	* each of which itself is a concurrently readable hash table.
222	>	* Overview:
223	>	*
224	>	* The primary design goal of this hash table is to maintain
225	>	* concurrent readability (typically method get(), but also
226	>	* iterators and related methods) while minimizing update
227	>	* contention. Secondary goals are to keep space consumption about
228	>	* the same or better than java.util.HashMap, and to support high
229	>	* initial insertion rates on an empty table by many threads.
230	>	*
231	>	* Each key-value mapping is held in a Node.  Because Node key
232	>	* fields can contain special values, they are defined using plain
233	>	* Object types (not type "K"). This leads to a lot of explicit
234	>	* casting (and many explicit warning suppressions to tell
235	>	* compilers not to complain about it). It also allows some of the
236	>	* public methods to be factored into a smaller number of internal
237	>	* methods (although sadly not so for the five variants of
238	>	* put-related operations). The validation-based approach
239	>	* explained below leads to a lot of code sprawl because
240	>	* retry-control precludes factoring into smaller methods.
241	>	*
242	>	* The table is lazily initialized to a power-of-two size upon the
243	>	* first insertion.  Each bin in the table normally contains a
244	>	* list of Nodes (most often, the list has only zero or one Node).
245	>	* Table accesses require volatile/atomic reads, writes, and
246	>	* CASes.  Because there is no other way to arrange this without
247	>	* adding further indirections, we use intrinsics
248	>	* (sun.misc.Unsafe) operations.  The lists of nodes within bins
249	>	* are always accurately traversable under volatile reads, so long
250	>	* as lookups check hash code and non-nullness of value before
251	>	* checking key equality.
252	>	*
253	>	* We use the top (sign) bit of Node hash fields for control
254	>	* purposes -- it is available anyway because of addressing
255	>	* constraints.  Nodes with negative hash fields are forwarding
256	>	* nodes to either TreeBins or resized tables.  The lower 31 bits
257	>	* of each normal Node's hash field contain a transformation of
258	>	* the key's hash code.
259	>	*
260	>	* Insertion (via put or its variants) of the first node in an
261	>	* empty bin is performed by just CASing it to the bin.  This is
262	>	* by far the most common case for put operations under most
263	>	* key/hash distributions.  Other update operations (insert,
264	>	* delete, and replace) require locks.  We do not want to waste
265	>	* the space required to associate a distinct lock object with
266	>	* each bin, so instead use the first node of a bin list itself as
267	>	* a lock. Locking support for these locks relies on builtin
268	>	* "synchronized" monitors.
269	>	*
270	>	* Using the first node of a list as a lock does not by itself
271	>	* suffice though: When a node is locked, any update must first
272	>	* validate that it is still the first node after locking it, and
273	>	* retry if not. Because new nodes are always appended to lists,
274	>	* once a node is first in a bin, it remains first until deleted
275	>	* or the bin becomes invalidated (upon resizing).  However,
276	>	* operations that only conditionally update may inspect nodes
277	>	* until the point of update. This is a converse of sorts to the
278	>	* lazy locking technique described by Herlihy & Shavit.
279	>	*
280	>	* The main disadvantage of per-bin locks is that other update
281	>	* operations on other nodes in a bin list protected by the same
282	>	* lock can stall, for example when user equals() or mapping
283	>	* functions take a long time.  However, statistically, under
284	>	* random hash codes, this is not a common problem.  Ideally, the
285	>	* frequency of nodes in bins follows a Poisson distribution
286	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
287	>	* parameter of about 0.5 on average, given the resizing threshold
288	>	* of 0.75, although with a large variance because of resizing
289	>	* granularity. Ignoring variance, the expected occurrences of
290	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
291	>	* first values are:
292	>	*
293	>	* 0:    0.60653066
294	>	* 1:    0.30326533
295	>	* 2:    0.07581633
296	>	* 3:    0.01263606
297	>	* 4:    0.00157952
298	>	* 5:    0.00015795
299	>	* 6:    0.00001316
300	>	* 7:    0.00000094
301	>	* 8:    0.00000006
302	>	* more: less than 1 in ten million
303	>	*
304	>	* Lock contention probability for two threads accessing distinct
305	>	* elements is roughly 1 / (8 * #elements) under random hashes.
306	>	*
307	>	* Actual hash code distributions encountered in practice
308	>	* sometimes deviate significantly from uniform randomness.  This
309	>	* includes the case when N > (1<<30), so some keys MUST collide.
310	>	* Similarly for dumb or hostile usages in which multiple keys are
311	>	* designed to have identical hash codes. Also, although we guard
312	>	* against the worst effects of this (see method spread), sets of
313	>	* hashes may differ only in bits that do not impact their bin
314	>	* index for a given power-of-two mask.  So we use a secondary
315	>	* strategy that applies when the number of nodes in a bin exceeds
316	>	* a threshold, and at least one of the keys implements
317	>	* Comparable.  These TreeBins use a balanced tree to hold nodes
318	>	* (a specialized form of red-black trees), bounding search time
319	>	* to O(log N).  Each search step in a TreeBin is around twice as
320	>	* slow as in a regular list, but given that N cannot exceed
321	>	* (1<<64) (before running out of addresses) this bounds search
322	>	* steps, lock hold times, etc, to reasonable constants (roughly
323	>	* 100 nodes inspected per operation worst case) so long as keys
324	>	* are Comparable (which is very common -- String, Long, etc).
325	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
326	>	* traversal pointers as regular nodes, so can be traversed in
327	>	* iterators in the same way.
328	>	*
329	>	* The table is resized when occupancy exceeds a percentage
330	>	* threshold (nominally, 0.75, but see below).  Any thread
331	>	* noticing an overfull bin may assist in resizing after the
332	>	* initiating thread allocates and sets up the replacement
333	>	* array. However, rather than stalling, these other threads may
334	>	* proceed with insertions etc.  The use of TreeBins shields us
335	>	* from the worst case effects of overfilling while resizes are in
336	>	* progress.  Resizing proceeds by transferring bins, one by one,
337	>	* from the table to the next table. To enable concurrency, the
338	>	* next table must be (incrementally) prefilled with place-holders
339	>	* serving as reverse forwarders to the old table.  Because we are
340	>	* using power-of-two expansion, the elements from each bin must
341	>	* either stay at same index, or move with a power of two
342	>	* offset. We eliminate unnecessary node creation by catching
343	>	* cases where old nodes can be reused because their next fields
344	>	* won't change.  On average, only about one-sixth of them need
345	>	* cloning when a table doubles. The nodes they replace will be
346	>	* garbage collectable as soon as they are no longer referenced by
347	>	* any reader thread that may be in the midst of concurrently
348	>	* traversing table.  Upon transfer, the old table bin contains
349	>	* only a special forwarding node (with hash field "MOVED") that
350	>	* contains the next table as its key. On encountering a
351	>	* forwarding node, access and update operations restart, using
352	>	* the new table.
353	>	*
354	>	* Each bin transfer requires its bin lock, which can stall
355	>	* waiting for locks while resizing. However, because other
356	>	* threads can join in and help resize rather than contend for
357	>	* locks, average aggregate waits become shorter as resizing
358	>	* progresses.  The transfer operation must also ensure that all
359	>	* accessible bins in both the old and new table are usable by any
360	>	* traversal.  This is arranged by proceeding from the last bin
361	>	* (table.length - 1) up towards the first.  Upon seeing a
362	>	* forwarding node, traversals (see class Traverser) arrange to
363	>	* move to the new table without revisiting nodes.  However, to
364	>	* ensure that no intervening nodes are skipped, bin splitting can
365	>	* only begin after the associated reverse-forwarders are in
366	>	* place.
367	>	*
368	>	* The traversal scheme also applies to partial traversals of
369	>	* ranges of bins (via an alternate Traverser constructor)
370	>	* to support partitioned aggregate operations.  Also, read-only
371	>	* operations give up if ever forwarded to a null table, which
372	>	* provides support for shutdown-style clearing, which is also not
373	>	* currently implemented.
374	>	*
375	>	* Lazy table initialization minimizes footprint until first use,
376	>	* and also avoids resizings when the first operation is from a
377	>	* putAll, constructor with map argument, or deserialization.
378	>	* These cases attempt to override the initial capacity settings,
379	>	* but harmlessly fail to take effect in cases of races.
380	>	*
381	>	* The element count is maintained using a specialization of
382	>	* LongAdder. We need to incorporate a specialization rather than
383	>	* just use a LongAdder in order to access implicit
384	>	* contention-sensing that leads to creation of multiple
385	>	* Cells.  The counter mechanics avoid contention on
386	>	* updates but can encounter cache thrashing if read too
387	>	* frequently during concurrent access. To avoid reading so often,
388	>	* resizing under contention is attempted only upon adding to a
389	>	* bin already holding two or more nodes. Under uniform hash
390	>	* distributions, the probability of this occurring at threshold
391	>	* is around 13%, meaning that only about 1 in 8 puts check
392	>	* threshold (and after resizing, many fewer do so). The bulk
393	>	* putAll operation further reduces contention by only committing
394	>	* count updates upon these size checks.
395	>	*
396	>	* Maintaining API and serialization compatibility with previous
397	>	* versions of this class introduces several oddities. Mainly: We
398	>	* leave untouched but unused constructor arguments refering to
399	>	* concurrencyLevel. We accept a loadFactor constructor argument,
400	>	* but apply it only to initial table capacity (which is the only
401	>	* time that we can guarantee to honor it.) We also declare an
402	>	* unused "Segment" class that is instantiated in minimal form
403	>	* only when serializing.
404		*/
405
406		/* ---------------- Constants -------------- */
407
408		/**
409	<	* The default initial capacity for this table,
410	<	* used when not otherwise specified in a constructor.
409	>	* The largest possible table capacity.  This value must be
410	>	* exactly 1<<30 to stay within Java array allocation and indexing
411	>	* bounds for power of two table sizes, and is further required
412	>	* because the top two bits of 32bit hash fields are used for
413	>	* control purposes.
414		*/
415	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
415	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
416
417		/**
418	<	* The default load factor for this table, used when not
419	<	* otherwise specified in a constructor.
418	>	* The default initial table capacity.  Must be a power of 2
419	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
420		*/
421	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
421	>	private static final int DEFAULT_CAPACITY = 16;
422
423		/**
424	<	* The default concurrency level for this table, used when not
425	<	* otherwise specified in a constructor.
424	>	* The largest possible (non-power of two) array size.
425	>	* Needed by toArray and related methods.
426		*/
427	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
427	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
428
429		/**
430	<	* The maximum capacity, used if a higher value is implicitly
431	<	* specified by either of the constructors with arguments.  MUST
105	<	* be a power of two <= 1<<30 to ensure that entries are indexable
106	<	* using ints.
430	>	* The default concurrency level for this table. Unused but
431	>	* defined for compatibility with previous versions of this class.
432		*/
433	<	static final int MAXIMUM_CAPACITY = 1 << 30;
433	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
434
435		/**
436	<	* The maximum number of segments to allow; used to bound
437	<	* constructor arguments.
436	>	* The load factor for this table. Overrides of this value in
437	>	* constructors affect only the initial table capacity.  The
438	>	* actual floating point value isn't normally used -- it is
439	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
440	>	* the associated resizing threshold.
441		*/
442	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
442	>	private static final float LOAD_FACTOR = 0.75f;
443
444		/**
445	<	* Number of unsynchronized retries in size and containsValue
446	<	* methods before resorting to locking. This is used to avoid
447	<	* unbounded retries if tables undergo continuous modification
120	<	* which would make it impossible to obtain an accurate result.
445	>	* The bin count threshold for using a tree rather than list for a
446	>	* bin.  The value reflects the approximate break-even point for
447	>	* using tree-based operations.
448		*/
449	<	static final int RETRIES_BEFORE_LOCK = 2;
449	>	private static final int TREE_THRESHOLD = 8;
450	>
451	>	/**
452	>	* Minimum number of rebinnings per transfer step. Ranges are
453	>	* subdivided to allow multiple resizer threads.  This value
454	>	* serves as a lower bound to avoid resizers encountering
455	>	* excessive memory contention.  The value should be at least
456	>	* DEFAULT_CAPACITY.
457	>	*/
458	>	private static final int MIN_TRANSFER_STRIDE = 16;
459	>
460	>	/*
461	>	* Encodings for Node hash fields. See above for explanation.
462	>	*/
463	>	static final int MOVED     = 0x80000000; // hash field for forwarding nodes
464	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
465	>
466	>	/** Number of CPUS, to place bounds on some sizings */
467	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
468	>
469	>	/* ---------------- Counters -------------- */
470	>
471	>	// Adapted from LongAdder and Striped64.
472	>	// See their internal docs for explanation.
473	>
474	>	// A padded cell for distributing counts
475	>	static final class Cell {
476	>	volatile long p0, p1, p2, p3, p4, p5, p6;
477	>	volatile long value;
478	>	volatile long q0, q1, q2, q3, q4, q5, q6;
479	>	Cell(long x) { value = x; }
480	>	}
481
482		/* ---------------- Fields -------------- */
483
484		/**
485	<	* Mask value for indexing into segments. The upper bits of a
486	<	* key's hash code are used to choose the segment.
485	>	* The array of bins. Lazily initialized upon first insertion.
486	>	* Size is always a power of two. Accessed directly by iterators.
487		*/
488	<	final int segmentMask;
488	>	transient volatile Node<V>[] table;
489
490		/**
491	<	* Shift value for indexing within segments.
491	>	* The next table to use; non-null only while resizing.
492		*/
493	<	final int segmentShift;
493	>	private transient volatile Node<V>[] nextTable;
494
495		/**
496	<	* The segments, each of which is a specialized hash table
496	>	* Base counter value, used mainly when there is no contention,
497	>	* but also as a fallback during table initialization
498	>	* races. Updated via CAS.
499		*/
500	<	final Segment<K,V>[] segments;
500	>	private transient volatile long baseCount;
501
502	<	transient Set<K> keySet;
503	<	transient Set<Map.Entry<K,V>> entrySet;
504	<	transient Collection<V> values;
502	>	/**
503	>	* Table initialization and resizing control.  When negative, the
504	>	* table is being initialized or resized: -1 for initialization,
505	>	* else -(1 + the number of active resizing threads).  Otherwise,
506	>	* when table is null, holds the initial table size to use upon
507	>	* creation, or 0 for default. After initialization, holds the
508	>	* next element count value upon which to resize the table.
509	>	*/
510	>	private transient volatile int sizeCtl;
511
512	<	/* ---------------- Small Utilities -------------- */
512	>	/**
513	>	* The next table index (plus one) to split while resizing.
514	>	*/
515	>	private transient volatile int transferIndex;
516
517		/**
518	<	* Applies a supplemental hash function to a given hashCode, which
150	<	* defends against poor quality hash functions.  This is critical
151	<	* because ConcurrentHashMap uses power-of-two length hash tables,
152	<	* that otherwise encounter collisions for hashCodes that do not
153	<	* differ in lower bits.
518	>	* The least available table index to split while resizing.
519		*/
520	<	private static int hash(int h) {
156	<	// Spread bits to regularize both segment and index locations,
157	<	// using variant of Jenkins's shift-based hash.
158	<	h += ~(h << 13);
159	<	h ^= h >>> 7;
160	<	h += h << 3;
161	<	h ^= h >>> 17;
162	<	h += h << 5;
163	<	return h;
164	<	}
520	>	private transient volatile int transferOrigin;
521
522		/**
523	<	* Returns the segment that should be used for key with given hash
524	<	* @param hash the hash code for the key
525	<	* @return the segment
523	>	* Spinlock (locked via CAS) used when resizing and/or creating Cells.
524	>	*/
525	>	private transient volatile int cellsBusy;
526	>
527	>	/**
528	>	* Table of counter cells. When non-null, size is a power of 2.
529	>	*/
530	>	private transient volatile Cell[] counterCells;
531	>
532	>	// views
533	>	private transient KeySetView<K,V> keySet;
534	>	private transient ValuesView<K,V> values;
535	>	private transient EntrySetView<K,V> entrySet;
536	>
537	>	/** For serialization compatibility. Null unless serialized; see below */
538	>	private Segment<K,V>[] segments;
539	>
540	>	/* ---------------- Table element access -------------- */
541	>
542	>	/*
543	>	* Volatile access methods are used for table elements as well as
544	>	* elements of in-progress next table while resizing.  Uses are
545	>	* null checked by callers, and implicitly bounds-checked, relying
546	>	* on the invariants that tab arrays have non-zero size, and all
547	>	* indices are masked with (tab.length - 1) which is never
548	>	* negative and always less than length. Note that, to be correct
549	>	* wrt arbitrary concurrency errors by users, bounds checks must
550	>	* operate on local variables, which accounts for some odd-looking
551	>	* inline assignments below.
552		*/
553	<	final Segment<K,V> segmentFor(int hash) {
554	<	return segments[(hash >>> segmentShift) & segmentMask];
553	>
554	>	@SuppressWarnings("unchecked") static final <V> Node<V> tabAt
555	>	(Node<V>[] tab, int i) { // used by Traverser
556	>	return (Node<V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
557		}
558
559	<	/* ---------------- Inner Classes -------------- */
559	>	private static final <V> boolean casTabAt
560	>	(Node<V>[] tab, int i, Node<V> c, Node<V> v) {
561	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
562	>	}
563	>
564	>	private static final <V> void setTabAt
565	>	(Node<V>[] tab, int i, Node<V> v) {
566	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
567	>	}
568	>
569	>	/* ---------------- Nodes -------------- */
570
571		/**
572	<	* ConcurrentHashMap list entry. Note that this is never exported
573	<	* out as a user-visible Map.Entry.
574	<	*
575	<	* Because the value field is volatile, not final, it is legal wrt
576	<	* the Java Memory Model for an unsynchronized reader to see null
577	<	* instead of initial value when read via a data race.  Although a
578	<	* reordering leading to this is not likely to ever actually
579	<	* occur, the Segment.readValueUnderLock method is used as a
186	<	* backup in case a null (pre-initialized) value is ever seen in
187	<	* an unsynchronized access method.
572	>	* Key-value entry. Note that this is never exported out as a
573	>	* user-visible Map.Entry (see MapEntry below). Nodes with a hash
574	>	* field of MOVED are special, and do not contain user keys or
575	>	* values.  Otherwise, keys are never null, and null val fields
576	>	* indicate that a node is in the process of being deleted or
577	>	* created. For purposes of read-only access, a key may be read
578	>	* before a val, but can only be used after checking val to be
579	>	* non-null.
580		*/
581	<	static final class HashEntry<K,V> {
190	<	final K key;
581	>	static class Node<V> {
582		final int hash;
583	<	volatile V value;
584	<	final HashEntry<K,V> next;
583	>	final Object key;
584	>	volatile V val;
585	>	volatile Node<V> next;
586
587	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
196	<	this.key = key;
587	>	Node(int hash, Object key, V val, Node<V> next) {
588		this.hash = hash;
589	+	this.key = key;
590	+	this.val = val;
591		this.next = next;
199	–	this.value = value;
592		}
201	–
202	–	@SuppressWarnings("unchecked")
203	–	static final <K,V> HashEntry<K,V>[] newArray(int i) {
204	–	return new HashEntry[i];
205	–	}
593		}
594
595	+	/* ---------------- TreeBins -------------- */
596	+
597		/**
598	<	* Segments are specialized versions of hash tables.  This
599	<	* subclasses from ReentrantLock opportunistically, just to
600	<	* simplify some locking and avoid separate construction.
601	<	*/
602	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
603	<	/*
604	<	* Segments maintain a table of entry lists that are ALWAYS
605	<	* kept in a consistent state, so can be read without locking.
606	<	* Next fields of nodes are immutable (final).  All list
607	<	* additions are performed at the front of each bin. This
608	<	* makes it easy to check changes, and also fast to traverse.
609	<	* When nodes would otherwise be changed, new nodes are
610	<	* created to replace them. This works well for hash tables
611	<	* since the bin lists tend to be short. (The average length
223	<	* is less than two for the default load factor threshold.)
224	<	*
225	<	* Read operations can thus proceed without locking, but rely
226	<	* on selected uses of volatiles to ensure that completed
227	<	* write operations performed by other threads are
228	<	* noticed. For most purposes, the "count" field, tracking the
229	<	* number of elements, serves as that volatile variable
230	<	* ensuring visibility.  This is convenient because this field
231	<	* needs to be read in many read operations anyway:
232	<	*
233	<	*   - All (unsynchronized) read operations must first read the
234	<	*     "count" field, and should not look at table entries if
235	<	*     it is 0.
236	<	*
237	<	*   - All (synchronized) write operations should write to
238	<	*     the "count" field after structurally changing any bin.
239	<	*     The operations must not take any action that could even
240	<	*     momentarily cause a concurrent read operation to see
241	<	*     inconsistent data. This is made easier by the nature of
242	<	*     the read operations in Map. For example, no operation
243	<	*     can reveal that the table has grown but the threshold
244	<	*     has not yet been updated, so there are no atomicity
245	<	*     requirements for this with respect to reads.
246	<	*
247	<	* As a guide, all critical volatile reads and writes to the
248	<	* count field are marked in code comments.
249	<	*/
598	>	* Nodes for use in TreeBins
599	>	*/
600	>	static final class TreeNode<V> extends Node<V> {
601	>	TreeNode<V> parent;  // red-black tree links
602	>	TreeNode<V> left;
603	>	TreeNode<V> right;
604	>	TreeNode<V> prev;    // needed to unlink next upon deletion
605	>	boolean red;
606	>
607	>	TreeNode(int hash, Object key, V val, Node<V> next, TreeNode<V> parent) {
608	>	super(hash, key, val, next);
609	>	this.parent = parent;
610	>	}
611	>	}
612
613	+	/**
614	+	* A specialized form of red-black tree for use in bins
615	+	* whose size exceeds a threshold.
616	+	*
617	+	* TreeBins use a special form of comparison for search and
618	+	* related operations (which is the main reason we cannot use
619	+	* existing collections such as TreeMaps). TreeBins contain
620	+	* Comparable elements, but may contain others, as well as
621	+	* elements that are Comparable but not necessarily Comparable<T>
622	+	* for the same T, so we cannot invoke compareTo among them. To
623	+	* handle this, the tree is ordered primarily by hash value, then
624	+	* by getClass().getName() order, and then by Comparator order
625	+	* among elements of the same class.  On lookup at a node, if
626	+	* elements are not comparable or compare as 0, both left and
627	+	* right children may need to be searched in the case of tied hash
628	+	* values. (This corresponds to the full list search that would be
629	+	* necessary if all elements were non-Comparable and had tied
630	+	* hashes.)  The red-black balancing code is updated from
631	+	* pre-jdk-collections
632	+	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
633	+	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
634	+	* Algorithms" (CLR).
635	+	*
636	+	* TreeBins also maintain a separate locking discipline than
637	+	* regular bins. Because they are forwarded via special MOVED
638	+	* nodes at bin heads (which can never change once established),
639	+	* we cannot use those nodes as locks. Instead, TreeBin
640	+	* extends AbstractQueuedSynchronizer to support a simple form of
641	+	* read-write lock. For update operations and table validation,
642	+	* the exclusive form of lock behaves in the same way as bin-head
643	+	* locks. However, lookups use shared read-lock mechanics to allow
644	+	* multiple readers in the absence of writers.  Additionally,
645	+	* these lookups do not ever block: While the lock is not
646	+	* available, they proceed along the slow traversal path (via
647	+	* next-pointers) until the lock becomes available or the list is
648	+	* exhausted, whichever comes first. (These cases are not fast,
649	+	* but maximize aggregate expected throughput.)  The AQS mechanics
650	+	* for doing this are straightforward.  The lock state is held as
651	+	* AQS getState().  Read counts are negative; the write count (1)
652	+	* is positive.  There are no signalling preferences among readers
653	+	* and writers. Since we don't need to export full Lock API, we
654	+	* just override the minimal AQS methods and use them directly.
655	+	*/
656	+	static final class TreeBin<V> extends AbstractQueuedSynchronizer {
657		private static final long serialVersionUID = 2249069246763182397L;
658	+	transient TreeNode<V> root;  // root of tree
659	+	transient TreeNode<V> first; // head of next-pointer list
660
661	<	/**
662	<	* The number of elements in this segment's region.
663	<	*/
664	<	transient volatile int count;
661	>	/* AQS overrides */
662	>	public final boolean isHeldExclusively() { return getState() > 0; }
663	>	public final boolean tryAcquire(int ignore) {
664	>	if (compareAndSetState(0, 1)) {
665	>	setExclusiveOwnerThread(Thread.currentThread());
666	>	return true;
667	>	}
668	>	return false;
669	>	}
670	>	public final boolean tryRelease(int ignore) {
671	>	setExclusiveOwnerThread(null);
672	>	setState(0);
673	>	return true;
674	>	}
675	>	public final int tryAcquireShared(int ignore) {
676	>	for (int c;;) {
677	>	if ((c = getState()) > 0)
678	>	return -1;
679	>	if (compareAndSetState(c, c -1))
680	>	return 1;
681	>	}
682	>	}
683	>	public final boolean tryReleaseShared(int ignore) {
684	>	int c;
685	>	do {} while (!compareAndSetState(c = getState(), c + 1));
686	>	return c == -1;
687	>	}
688	>
689	>	/** From CLR */
690	>	private void rotateLeft(TreeNode<V> p) {
691	>	if (p != null) {
692	>	TreeNode<V> r = p.right, pp, rl;
693	>	if ((rl = p.right = r.left) != null)
694	>	rl.parent = p;
695	>	if ((pp = r.parent = p.parent) == null)
696	>	root = r;
697	>	else if (pp.left == p)
698	>	pp.left = r;
699	>	else
700	>	pp.right = r;
701	>	r.left = p;
702	>	p.parent = r;
703	>	}
704	>	}
705
706	<	/**
707	<	* Number of updates that alter the size of the table. This is
708	<	* used during bulk-read methods to make sure they see a
709	<	* consistent snapshot: If modCounts change during a traversal
710	<	* of segments computing size or checking containsValue, then
711	<	* we might have an inconsistent view of state so (usually)
712	<	* must retry.
713	<	*/
714	<	transient int modCount;
706	>	/** From CLR */
707	>	private void rotateRight(TreeNode<V> p) {
708	>	if (p != null) {
709	>	TreeNode<V> l = p.left, pp, lr;
710	>	if ((lr = p.left = l.right) != null)
711	>	lr.parent = p;
712	>	if ((pp = l.parent = p.parent) == null)
713	>	root = l;
714	>	else if (pp.right == p)
715	>	pp.right = l;
716	>	else
717	>	pp.left = l;
718	>	l.right = p;
719	>	p.parent = l;
720	>	}
721	>	}
722
723		/**
724	<	* The table is rehashed when its size exceeds this threshold.
725	<	* (The value of this field is always <tt>(int)(capacity *
271	<	* loadFactor)</tt>.)
724	>	* Returns the TreeNode (or null if not found) for the given key
725	>	* starting at given root.
726		*/
727	<	transient int threshold;
727	>	@SuppressWarnings("unchecked") final TreeNode<V> getTreeNode
728	>	(int h, Object k, TreeNode<V> p) {
729	>	Class<?> c = k.getClass();
730	>	while (p != null) {
731	>	int dir, ph;  Object pk; Class<?> pc;
732	>	if ((ph = p.hash) == h) {
733	>	if ((pk = p.key) == k || k.equals(pk))
734	>	return p;
735	>	if (c != (pc = pk.getClass()) ||
736	>	!(k instanceof Comparable) ||
737	>	(dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
738	>	if ((dir = (c == pc) ? 0 :
739	>	c.getName().compareTo(pc.getName())) == 0) {
740	>	TreeNode<V> r = null, pl, pr; // check both sides
741	>	if ((pr = p.right) != null && h >= pr.hash &&
742	>	(r = getTreeNode(h, k, pr)) != null)
743	>	return r;
744	>	else if ((pl = p.left) != null && h <= pl.hash)
745	>	dir = -1;
746	>	else // nothing there
747	>	return null;
748	>	}
749	>	}
750	>	}
751	>	else
752	>	dir = (h < ph) ? -1 : 1;
753	>	p = (dir > 0) ? p.right : p.left;
754	>	}
755	>	return null;
756	>	}
757
758		/**
759	<	* The per-segment table.
759	>	* Wrapper for getTreeNode used by CHM.get. Tries to obtain
760	>	* read-lock to call getTreeNode, but during failure to get
761	>	* lock, searches along next links.
762		*/
763	<	transient volatile HashEntry<K,V>[] table;
763	>	final V getValue(int h, Object k) {
764	>	Node<V> r = null;
765	>	int c = getState(); // Must read lock state first
766	>	for (Node<V> e = first; e != null; e = e.next) {
767	>	if (c <= 0 && compareAndSetState(c, c - 1)) {
768	>	try {
769	>	r = getTreeNode(h, k, root);
770	>	} finally {
771	>	releaseShared(0);
772	>	}
773	>	break;
774	>	}
775	>	else if (e.hash == h && k.equals(e.key)) {
776	>	r = e;
777	>	break;
778	>	}
779	>	else
780	>	c = getState();
781	>	}
782	>	return r == null ? null : r.val;
783	>	}
784
785		/**
786	<	* The load factor for the hash table.  Even though this value
787	<	* is same for all segments, it is replicated to avoid needing
283	<	* links to outer object.
284	<	* @serial
786	>	* Finds or adds a node.
787	>	* @return null if added
788		*/
789	<	final float loadFactor;
790	<
791	<	Segment(int initialCapacity, float lf) {
792	<	loadFactor = lf;
793	<	setTable(HashEntry.<K,V>newArray(initialCapacity));
794	<	}
789	>	@SuppressWarnings("unchecked") final TreeNode<V> putTreeNode
790	>	(int h, Object k, V v) {
791	>	Class<?> c = k.getClass();
792	>	TreeNode<V> pp = root, p = null;
793	>	int dir = 0;
794	>	while (pp != null) { // find existing node or leaf to insert at
795	>	int ph;  Object pk; Class<?> pc;
796	>	p = pp;
797	>	if ((ph = p.hash) == h) {
798	>	if ((pk = p.key) == k || k.equals(pk))
799	>	return p;
800	>	if (c != (pc = pk.getClass()) ||
801	>	!(k instanceof Comparable) ||
802	>	(dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) {
803	>	TreeNode<V> s = null, r = null, pr;
804	>	if ((dir = (c == pc) ? 0 :
805	>	c.getName().compareTo(pc.getName())) == 0) {
806	>	if ((pr = p.right) != null && h >= pr.hash &&
807	>	(r = getTreeNode(h, k, pr)) != null)
808	>	return r;
809	>	else // continue left
810	>	dir = -1;
811	>	}
812	>	else if ((pr = p.right) != null && h >= pr.hash)
813	>	s = pr;
814	>	if (s != null && (r = getTreeNode(h, k, s)) != null)
815	>	return r;
816	>	}
817	>	}
818	>	else
819	>	dir = (h < ph) ? -1 : 1;
820	>	pp = (dir > 0) ? p.right : p.left;
821	>	}
822
823	<	@SuppressWarnings("unchecked")
824	<	static final <K,V> Segment<K,V>[] newArray(int i) {
825	<	return new Segment[i];
823	>	TreeNode<V> f = first;
824	>	TreeNode<V> x = first = new TreeNode<V>(h, k, v, f, p);
825	>	if (p == null)
826	>	root = x;
827	>	else { // attach and rebalance; adapted from CLR
828	>	TreeNode<V> xp, xpp;
829	>	if (f != null)
830	>	f.prev = x;
831	>	if (dir <= 0)
832	>	p.left = x;
833	>	else
834	>	p.right = x;
835	>	x.red = true;
836	>	while (x != null && (xp = x.parent) != null && xp.red &&
837	>	(xpp = xp.parent) != null) {
838	>	TreeNode<V> xppl = xpp.left;
839	>	if (xp == xppl) {
840	>	TreeNode<V> y = xpp.right;
841	>	if (y != null && y.red) {
842	>	y.red = false;
843	>	xp.red = false;
844	>	xpp.red = true;
845	>	x = xpp;
846	>	}
847	>	else {
848	>	if (x == xp.right) {
849	>	rotateLeft(x = xp);
850	>	xpp = (xp = x.parent) == null ? null : xp.parent;
851	>	}
852	>	if (xp != null) {
853	>	xp.red = false;
854	>	if (xpp != null) {
855	>	xpp.red = true;
856	>	rotateRight(xpp);
857	>	}
858	>	}
859	>	}
860	>	}
861	>	else {
862	>	TreeNode<V> y = xppl;
863	>	if (y != null && y.red) {
864	>	y.red = false;
865	>	xp.red = false;
866	>	xpp.red = true;
867	>	x = xpp;
868	>	}
869	>	else {
870	>	if (x == xp.left) {
871	>	rotateRight(x = xp);
872	>	xpp = (xp = x.parent) == null ? null : xp.parent;
873	>	}
874	>	if (xp != null) {
875	>	xp.red = false;
876	>	if (xpp != null) {
877	>	xpp.red = true;
878	>	rotateLeft(xpp);
879	>	}
880	>	}
881	>	}
882	>	}
883	>	}
884	>	TreeNode<V> r = root;
885	>	if (r != null && r.red)
886	>	r.red = false;
887	>	}
888	>	return null;
889		}
890
891		/**
892	<	* Sets table to new HashEntry array.
893	<	* Call only while holding lock or in constructor.
892	>	* Removes the given node, that must be present before this
893	>	* call.  This is messier than typical red-black deletion code
894	>	* because we cannot swap the contents of an interior node
895	>	* with a leaf successor that is pinned by "next" pointers
896	>	* that are accessible independently of lock. So instead we
897	>	* swap the tree linkages.
898		*/
899	<	void setTable(HashEntry<K,V>[] newTable) {
900	<	threshold = (int)(newTable.length * loadFactor);
901	<	table = newTable;
899	>	final void deleteTreeNode(TreeNode<V> p) {
900	>	TreeNode<V> next = (TreeNode<V>)p.next; // unlink traversal pointers
901	>	TreeNode<V> pred = p.prev;
902	>	if (pred == null)
903	>	first = next;
904	>	else
905	>	pred.next = next;
906	>	if (next != null)
907	>	next.prev = pred;
908	>	TreeNode<V> replacement;
909	>	TreeNode<V> pl = p.left;
910	>	TreeNode<V> pr = p.right;
911	>	if (pl != null && pr != null) {
912	>	TreeNode<V> s = pr, sl;
913	>	while ((sl = s.left) != null) // find successor
914	>	s = sl;
915	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
916	>	TreeNode<V> sr = s.right;
917	>	TreeNode<V> pp = p.parent;
918	>	if (s == pr) { // p was s's direct parent
919	>	p.parent = s;
920	>	s.right = p;
921	>	}
922	>	else {
923	>	TreeNode<V> sp = s.parent;
924	>	if ((p.parent = sp) != null) {
925	>	if (s == sp.left)
926	>	sp.left = p;
927	>	else
928	>	sp.right = p;
929	>	}
930	>	if ((s.right = pr) != null)
931	>	pr.parent = s;
932	>	}
933	>	p.left = null;
934	>	if ((p.right = sr) != null)
935	>	sr.parent = p;
936	>	if ((s.left = pl) != null)
937	>	pl.parent = s;
938	>	if ((s.parent = pp) == null)
939	>	root = s;
940	>	else if (p == pp.left)
941	>	pp.left = s;
942	>	else
943	>	pp.right = s;
944	>	replacement = sr;
945	>	}
946	>	else
947	>	replacement = (pl != null) ? pl : pr;
948	>	TreeNode<V> pp = p.parent;
949	>	if (replacement == null) {
950	>	if (pp == null) {
951	>	root = null;
952	>	return;
953	>	}
954	>	replacement = p;
955	>	}
956	>	else {
957	>	replacement.parent = pp;
958	>	if (pp == null)
959	>	root = replacement;
960	>	else if (p == pp.left)
961	>	pp.left = replacement;
962	>	else
963	>	pp.right = replacement;
964	>	p.left = p.right = p.parent = null;
965	>	}
966	>	if (!p.red) { // rebalance, from CLR
967	>	TreeNode<V> x = replacement;
968	>	while (x != null) {
969	>	TreeNode<V> xp, xpl;
970	>	if (x.red || (xp = x.parent) == null) {
971	>	x.red = false;
972	>	break;
973	>	}
974	>	if (x == (xpl = xp.left)) {
975	>	TreeNode<V> sib = xp.right;
976	>	if (sib != null && sib.red) {
977	>	sib.red = false;
978	>	xp.red = true;
979	>	rotateLeft(xp);
980	>	sib = (xp = x.parent) == null ? null : xp.right;
981	>	}
982	>	if (sib == null)
983	>	x = xp;
984	>	else {
985	>	TreeNode<V> sl = sib.left, sr = sib.right;
986	>	if ((sr == null || !sr.red) &&
987	>	(sl == null || !sl.red)) {
988	>	sib.red = true;
989	>	x = xp;
990	>	}
991	>	else {
992	>	if (sr == null || !sr.red) {
993	>	if (sl != null)
994	>	sl.red = false;
995	>	sib.red = true;
996	>	rotateRight(sib);
997	>	sib = (xp = x.parent) == null ?
998	>	null : xp.right;
999	>	}
1000	>	if (sib != null) {
1001	>	sib.red = (xp == null) ? false : xp.red;
1002	>	if ((sr = sib.right) != null)
1003	>	sr.red = false;
1004	>	}
1005	>	if (xp != null) {
1006	>	xp.red = false;
1007	>	rotateLeft(xp);
1008	>	}
1009	>	x = root;
1010	>	}
1011	>	}
1012	>	}
1013	>	else { // symmetric
1014	>	TreeNode<V> sib = xpl;
1015	>	if (sib != null && sib.red) {
1016	>	sib.red = false;
1017	>	xp.red = true;
1018	>	rotateRight(xp);
1019	>	sib = (xp = x.parent) == null ? null : xp.left;
1020	>	}
1021	>	if (sib == null)
1022	>	x = xp;
1023	>	else {
1024	>	TreeNode<V> sl = sib.left, sr = sib.right;
1025	>	if ((sl == null || !sl.red) &&
1026	>	(sr == null || !sr.red)) {
1027	>	sib.red = true;
1028	>	x = xp;
1029	>	}
1030	>	else {
1031	>	if (sl == null || !sl.red) {
1032	>	if (sr != null)
1033	>	sr.red = false;
1034	>	sib.red = true;
1035	>	rotateLeft(sib);
1036	>	sib = (xp = x.parent) == null ?
1037	>	null : xp.left;
1038	>	}
1039	>	if (sib != null) {
1040	>	sib.red = (xp == null) ? false : xp.red;
1041	>	if ((sl = sib.left) != null)
1042	>	sl.red = false;
1043	>	}
1044	>	if (xp != null) {
1045	>	xp.red = false;
1046	>	rotateRight(xp);
1047	>	}
1048	>	x = root;
1049	>	}
1050	>	}
1051	>	}
1052	>	}
1053	>	}
1054	>	if (p == replacement && (pp = p.parent) != null) {
1055	>	if (p == pp.left) // detach pointers
1056	>	pp.left = null;
1057	>	else if (p == pp.right)
1058	>	pp.right = null;
1059	>	p.parent = null;
1060	>	}
1061		}
1062	+	}
1063
1064	<	/**
1065	<	* Returns properly casted first entry of bin for given hash.
1066	<	*/
1067	<	HashEntry<K,V> getFirst(int hash) {
1068	<	HashEntry<K,V>[] tab = table;
1069	<	return tab[hash & (tab.length - 1)];
1064	>	/* ---------------- Collision reduction methods -------------- */
1065	>
1066	>	/**
1067	>	* Spreads higher bits to lower, and also forces top bit to 0.
1068	>	* Because the table uses power-of-two masking, sets of hashes
1069	>	* that vary only in bits above the current mask will always
1070	>	* collide. (Among known examples are sets of Float keys holding
1071	>	* consecutive whole numbers in small tables.)  To counter this,
1072	>	* we apply a transform that spreads the impact of higher bits
1073	>	* downward. There is a tradeoff between speed, utility, and
1074	>	* quality of bit-spreading. Because many common sets of hashes
1075	>	* are already reasonably distributed across bits (so don't benefit
1076	>	* from spreading), and because we use trees to handle large sets
1077	>	* of collisions in bins, we don't need excessively high quality.
1078	>	*/
1079	>	private static final int spread(int h) {
1080	>	h ^= (h >>> 18) ^ (h >>> 12);
1081	>	return (h ^ (h >>> 10)) & HASH_BITS;
1082	>	}
1083	>
1084	>	/**
1085	>	* Replaces a list bin with a tree bin if key is comparable.  Call
1086	>	* only when locked.
1087	>	*/
1088	>	private final void replaceWithTreeBin(Node<V>[] tab, int index, Object key) {
1089	>	if (key instanceof Comparable) {
1090	>	TreeBin<V> t = new TreeBin<V>();
1091	>	for (Node<V> e = tabAt(tab, index); e != null; e = e.next)
1092	>	t.putTreeNode(e.hash, e.key, e.val);
1093	>	setTabAt(tab, index, new Node<V>(MOVED, t, null, null));
1094		}
1095	+	}
1096
1097	<	/**
1098	<	* Reads value field of an entry under lock. Called if value
1099	<	* field ever appears to be null. This is possible only if a
1100	<	* compiler happens to reorder a HashEntry initialization with
1101	<	* its table assignment, which is legal under memory model
1102	<	* but is not known to ever occur.
1103	<	*/
1104	<	V readValueUnderLock(HashEntry<K,V> e) {
1105	<	lock();
1106	<	try {
1107	<	return e.value;
1108	<	} finally {
1109	<	unlock();
1097	>	/* ---------------- Internal access and update methods -------------- */
1098	>
1099	>	/** Implementation for get and containsKey */
1100	>	@SuppressWarnings("unchecked") private final V internalGet(Object k) {
1101	>	int h = spread(k.hashCode());
1102	>	retry: for (Node<V>[] tab = table; tab != null;) {
1103	>	Node<V> e; Object ek; V ev; int eh; // locals to read fields once
1104	>	for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
1105	>	if ((eh = e.hash) < 0) {
1106	>	if ((ek = e.key) instanceof TreeBin)  // search TreeBin
1107	>	return ((TreeBin<V>)ek).getValue(h, k);
1108	>	else {                      // restart with new table
1109	>	tab = (Node<V>[])ek;
1110	>	continue retry;
1111	>	}
1112	>	}
1113	>	else if (eh == h && (ev = e.val) != null &&
1114	>	((ek = e.key) == k || k.equals(ek)))
1115	>	return ev;
1116		}
1117	+	break;
1118		}
1119	+	return null;
1120	+	}
1121
1122	<	/* Specialized implementations of map methods */
1123	<
1124	<	V get(Object key, int hash) {
1125	<	if (count != 0) { // read-volatile
1126	<	HashEntry<K,V> e = getFirst(hash);
1127	<	while (e != null) {
1128	<	if (e.hash == hash && key.equals(e.key)) {
1129	<	V v = e.value;
1130	<	if (v != null)
1131	<	return v;
1132	<	return readValueUnderLock(e); // recheck
1122	>	/**
1123	>	* Implementation for the four public remove/replace methods:
1124	>	* Replaces node value with v, conditional upon match of cv if
1125	>	* non-null.  If resulting value is null, delete.
1126	>	*/
1127	>	@SuppressWarnings("unchecked") private final V internalReplace
1128	>	(Object k, V v, Object cv) {
1129	>	int h = spread(k.hashCode());
1130	>	V oldVal = null;
1131	>	for (Node<V>[] tab = table;;) {
1132	>	Node<V> f; int i, fh; Object fk;
1133	>	if (tab == null ||
1134	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1135	>	break;
1136	>	else if ((fh = f.hash) < 0) {
1137	>	if ((fk = f.key) instanceof TreeBin) {
1138	>	TreeBin<V> t = (TreeBin<V>)fk;
1139	>	boolean validated = false;
1140	>	boolean deleted = false;
1141	>	t.acquire(0);
1142	>	try {
1143	>	if (tabAt(tab, i) == f) {
1144	>	validated = true;
1145	>	TreeNode<V> p = t.getTreeNode(h, k, t.root);
1146	>	if (p != null) {
1147	>	V pv = p.val;
1148	>	if (cv == null || cv == pv || cv.equals(pv)) {
1149	>	oldVal = pv;
1150	>	if ((p.val = v) == null) {
1151	>	deleted = true;
1152	>	t.deleteTreeNode(p);
1153	>	}
1154	>	}
1155	>	}
1156	>	}
1157	>	} finally {
1158	>	t.release(0);
1159	>	}
1160	>	if (validated) {
1161	>	if (deleted)
1162	>	addCount(-1L, -1);
1163	>	break;
1164		}
1165	<	e = e.next;
1165	>	}
1166	>	else
1167	>	tab = (Node<V>[])fk;
1168	>	}
1169	>	else if (fh != h && f.next == null) // precheck
1170	>	break;                          // rules out possible existence
1171	>	else {
1172	>	boolean validated = false;
1173	>	boolean deleted = false;
1174	>	synchronized (f) {
1175	>	if (tabAt(tab, i) == f) {
1176	>	validated = true;
1177	>	for (Node<V> e = f, pred = null;;) {
1178	>	Object ek; V ev;
1179	>	if (e.hash == h &&
1180	>	((ev = e.val) != null) &&
1181	>	((ek = e.key) == k || k.equals(ek))) {
1182	>	if (cv == null || cv == ev || cv.equals(ev)) {
1183	>	oldVal = ev;
1184	>	if ((e.val = v) == null) {
1185	>	deleted = true;
1186	>	Node<V> en = e.next;
1187	>	if (pred != null)
1188	>	pred.next = en;
1189	>	else
1190	>	setTabAt(tab, i, en);
1191	>	}
1192	>	}
1193	>	break;
1194	>	}
1195	>	pred = e;
1196	>	if ((e = e.next) == null)
1197	>	break;
1198	>	}
1199	>	}
1200	>	}
1201	>	if (validated) {
1202	>	if (deleted)
1203	>	addCount(-1L, -1);
1204	>	break;
1205		}
1206		}
346	–	return null;
1207		}
1208	+	return oldVal;
1209	+	}
1210
1211	<	boolean containsKey(Object key, int hash) {
1212	<	if (count != 0) { // read-volatile
1213	<	HashEntry<K,V> e = getFirst(hash);
1214	<	while (e != null) {
1215	<	if (e.hash == hash && key.equals(e.key))
1216	<	return true;
1217	<	e = e.next;
1211	>	/*
1212	>	* Internal versions of insertion methods
1213	>	* All have the same basic structure as the first (internalPut):
1214	>	*  1. If table uninitialized, create
1215	>	*  2. If bin empty, try to CAS new node
1216	>	*  3. If bin stale, use new table
1217	>	*  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1218	>	*  5. Lock and validate; if valid, scan and add or update
1219	>	*
1220	>	* The putAll method differs mainly in attempting to pre-allocate
1221	>	* enough table space, and also more lazily performs count updates
1222	>	* and checks.
1223	>	*
1224	>	* Most of the function-accepting methods can't be factored nicely
1225	>	* because they require different functional forms, so instead
1226	>	* sprawl out similar mechanics.
1227	>	*/
1228	>
1229	>	/** Implementation for put and putIfAbsent */
1230	>	@SuppressWarnings("unchecked") private final V internalPut
1231	>	(K k, V v, boolean onlyIfAbsent) {
1232	>	if (k == null || v == null) throw new NullPointerException();
1233	>	int h = spread(k.hashCode());
1234	>	int len = 0;
1235	>	for (Node<V>[] tab = table;;) {
1236	>	int i, fh; Node<V> f; Object fk; V fv;
1237	>	if (tab == null)
1238	>	tab = initTable();
1239	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1240	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null)))
1241	>	break;                   // no lock when adding to empty bin
1242	>	}
1243	>	else if ((fh = f.hash) < 0) {
1244	>	if ((fk = f.key) instanceof TreeBin) {
1245	>	TreeBin<V> t = (TreeBin<V>)fk;
1246	>	V oldVal = null;
1247	>	t.acquire(0);
1248	>	try {
1249	>	if (tabAt(tab, i) == f) {
1250	>	len = 2;
1251	>	TreeNode<V> p = t.putTreeNode(h, k, v);
1252	>	if (p != null) {
1253	>	oldVal = p.val;
1254	>	if (!onlyIfAbsent)
1255	>	p.val = v;
1256	>	}
1257	>	}
1258	>	} finally {
1259	>	t.release(0);
1260	>	}
1261	>	if (len != 0) {
1262	>	if (oldVal != null)
1263	>	return oldVal;
1264	>	break;
1265	>	}
1266	>	}
1267	>	else
1268	>	tab = (Node<V>[])fk;
1269	>	}
1270	>	else if (onlyIfAbsent && fh == h && (fv = f.val) != null &&
1271	>	((fk = f.key) == k || k.equals(fk))) // peek while nearby
1272	>	return fv;
1273	>	else {
1274	>	V oldVal = null;
1275	>	synchronized (f) {
1276	>	if (tabAt(tab, i) == f) {
1277	>	len = 1;
1278	>	for (Node<V> e = f;; ++len) {
1279	>	Object ek; V ev;
1280	>	if (e.hash == h &&
1281	>	(ev = e.val) != null &&
1282	>	((ek = e.key) == k || k.equals(ek))) {
1283	>	oldVal = ev;
1284	>	if (!onlyIfAbsent)
1285	>	e.val = v;
1286	>	break;
1287	>	}
1288	>	Node<V> last = e;
1289	>	if ((e = e.next) == null) {
1290	>	last.next = new Node<V>(h, k, v, null);
1291	>	if (len >= TREE_THRESHOLD)
1292	>	replaceWithTreeBin(tab, i, k);
1293	>	break;
1294	>	}
1295	>	}
1296	>	}
1297	>	}
1298	>	if (len != 0) {
1299	>	if (oldVal != null)
1300	>	return oldVal;
1301	>	break;
1302		}
1303		}
358	–	return false;
1304		}
1305	+	addCount(1L, len);
1306	+	return null;
1307	+	}
1308
1309	<	boolean containsValue(Object value) {
1310	<	if (count != 0) { // read-volatile
1311	<	HashEntry<K,V>[] tab = table;
1312	<	int len = tab.length;
1313	<	for (int i = 0 ; i < len; i++) {
1314	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
1315	<	V v = e.value;
1316	<	if (v == null) // recheck
1317	<	v = readValueUnderLock(e);
1318	<	if (value.equals(v))
1319	<	return true;
1309	>	/** Implementation for computeIfAbsent */
1310	>	@SuppressWarnings("unchecked") private final V internalComputeIfAbsent
1311	>	(K k, Function<? super K, ? extends V> mf) {
1312	>	if (k == null || mf == null)
1313	>	throw new NullPointerException();
1314	>	int h = spread(k.hashCode());
1315	>	V val = null;
1316	>	int len = 0;
1317	>	for (Node<V>[] tab = table;;) {
1318	>	Node<V> f; int i; Object fk;
1319	>	if (tab == null)
1320	>	tab = initTable();
1321	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1322	>	Node<V> node = new Node<V>(h, k, null, null);
1323	>	synchronized (node) {
1324	>	if (casTabAt(tab, i, null, node)) {
1325	>	len = 1;
1326	>	try {
1327	>	if ((val = mf.apply(k)) != null)
1328	>	node.val = val;
1329	>	} finally {
1330	>	if (val == null)
1331	>	setTabAt(tab, i, null);
1332	>	}
1333		}
1334		}
1335	+	if (len != 0)
1336	+	break;
1337	+	}
1338	+	else if (f.hash < 0) {
1339	+	if ((fk = f.key) instanceof TreeBin) {
1340	+	TreeBin<V> t = (TreeBin<V>)fk;
1341	+	boolean added = false;
1342	+	t.acquire(0);
1343	+	try {
1344	+	if (tabAt(tab, i) == f) {
1345	+	len = 1;
1346	+	TreeNode<V> p = t.getTreeNode(h, k, t.root);
1347	+	if (p != null)
1348	+	val = p.val;
1349	+	else if ((val = mf.apply(k)) != null) {
1350	+	added = true;
1351	+	len = 2;
1352	+	t.putTreeNode(h, k, val);
1353	+	}
1354	+	}
1355	+	} finally {
1356	+	t.release(0);
1357	+	}
1358	+	if (len != 0) {
1359	+	if (!added)
1360	+	return val;
1361	+	break;
1362	+	}
1363	+	}
1364	+	else
1365	+	tab = (Node<V>[])fk;
1366	+	}
1367	+	else {
1368	+	for (Node<V> e = f; e != null; e = e.next) { // prescan
1369	+	Object ek; V ev;
1370	+	if (e.hash == h && (ev = e.val) != null &&
1371	+	((ek = e.key) == k || k.equals(ek)))
1372	+	return ev;
1373	+	}
1374	+	boolean added = false;
1375	+	synchronized (f) {
1376	+	if (tabAt(tab, i) == f) {
1377	+	len = 1;
1378	+	for (Node<V> e = f;; ++len) {
1379	+	Object ek; V ev;
1380	+	if (e.hash == h &&
1381	+	(ev = e.val) != null &&
1382	+	((ek = e.key) == k || k.equals(ek))) {
1383	+	val = ev;
1384	+	break;
1385	+	}
1386	+	Node<V> last = e;
1387	+	if ((e = e.next) == null) {
1388	+	if ((val = mf.apply(k)) != null) {
1389	+	added = true;
1390	+	last.next = new Node<V>(h, k, val, null);
1391	+	if (len >= TREE_THRESHOLD)
1392	+	replaceWithTreeBin(tab, i, k);
1393	+	}
1394	+	break;
1395	+	}
1396	+	}
1397	+	}
1398	+	}
1399	+	if (len != 0) {
1400	+	if (!added)
1401	+	return val;
1402	+	break;
1403	+	}
1404		}
375	–	return false;
1405		}
1406	+	if (val != null)
1407	+	addCount(1L, len);
1408	+	return val;
1409	+	}
1410
1411	<	boolean replace(K key, int hash, V oldValue, V newValue) {
1412	<	lock();
1413	<	try {
1414	<	HashEntry<K,V> e = getFirst(hash);
1415	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1416	<	e = e.next;
1411	>	/** Implementation for compute */
1412	>	@SuppressWarnings("unchecked") private final V internalCompute
1413	>	(K k, boolean onlyIfPresent,
1414	>	BiFunction<? super K, ? super V, ? extends V> mf) {
1415	>	if (k == null || mf == null)
1416	>	throw new NullPointerException();
1417	>	int h = spread(k.hashCode());
1418	>	V val = null;
1419	>	int delta = 0;
1420	>	int len = 0;
1421	>	for (Node<V>[] tab = table;;) {
1422	>	Node<V> f; int i, fh; Object fk;
1423	>	if (tab == null)
1424	>	tab = initTable();
1425	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1426	>	if (onlyIfPresent)
1427	>	break;
1428	>	Node<V> node = new Node<V>(h, k, null, null);
1429	>	synchronized (node) {
1430	>	if (casTabAt(tab, i, null, node)) {
1431	>	try {
1432	>	len = 1;
1433	>	if ((val = mf.apply(k, null)) != null) {
1434	>	node.val = val;
1435	>	delta = 1;
1436	>	}
1437	>	} finally {
1438	>	if (delta == 0)
1439	>	setTabAt(tab, i, null);
1440	>	}
1441	>	}
1442	>	}
1443	>	if (len != 0)
1444	>	break;
1445	>	}
1446	>	else if ((fh = f.hash) < 0) {
1447	>	if ((fk = f.key) instanceof TreeBin) {
1448	>	TreeBin<V> t = (TreeBin<V>)fk;
1449	>	t.acquire(0);
1450	>	try {
1451	>	if (tabAt(tab, i) == f) {
1452	>	len = 1;
1453	>	TreeNode<V> p = t.getTreeNode(h, k, t.root);
1454	>	if (p == null && onlyIfPresent)
1455	>	break;
1456	>	V pv = (p == null) ? null : p.val;
1457	>	if ((val = mf.apply(k, pv)) != null) {
1458	>	if (p != null)
1459	>	p.val = val;
1460	>	else {
1461	>	len = 2;
1462	>	delta = 1;
1463	>	t.putTreeNode(h, k, val);
1464	>	}
1465	>	}
1466	>	else if (p != null) {
1467	>	delta = -1;
1468	>	t.deleteTreeNode(p);
1469	>	}
1470	>	}
1471	>	} finally {
1472	>	t.release(0);
1473	>	}
1474	>	if (len != 0)
1475	>	break;
1476	>	}
1477	>	else
1478	>	tab = (Node<V>[])fk;
1479	>	}
1480	>	else {
1481	>	synchronized (f) {
1482	>	if (tabAt(tab, i) == f) {
1483	>	len = 1;
1484	>	for (Node<V> e = f, pred = null;; ++len) {
1485	>	Object ek; V ev;
1486	>	if (e.hash == h &&
1487	>	(ev = e.val) != null &&
1488	>	((ek = e.key) == k || k.equals(ek))) {
1489	>	val = mf.apply(k, ev);
1490	>	if (val != null)
1491	>	e.val = val;
1492	>	else {
1493	>	delta = -1;
1494	>	Node<V> en = e.next;
1495	>	if (pred != null)
1496	>	pred.next = en;
1497	>	else
1498	>	setTabAt(tab, i, en);
1499	>	}
1500	>	break;
1501	>	}
1502	>	pred = e;
1503	>	if ((e = e.next) == null) {
1504	>	if (!onlyIfPresent &&
1505	>	(val = mf.apply(k, null)) != null) {
1506	>	pred.next = new Node<V>(h, k, val, null);
1507	>	delta = 1;
1508	>	if (len >= TREE_THRESHOLD)
1509	>	replaceWithTreeBin(tab, i, k);
1510	>	}
1511	>	break;
1512	>	}
1513	>	}
1514	>	}
1515	>	}
1516	>	if (len != 0)
1517	>	break;
1518	>	}
1519	>	}
1520	>	if (delta != 0)
1521	>	addCount((long)delta, len);
1522	>	return val;
1523	>	}
1524
1525	<	boolean replaced = false;
1526	<	if (e != null && oldValue.equals(e.value)) {
1527	<	replaced = true;
1528	<	e.value = newValue;
1525	>	/** Implementation for merge */
1526	>	@SuppressWarnings("unchecked") private final V internalMerge
1527	>	(K k, V v, BiFunction<? super V, ? super V, ? extends V> mf) {
1528	>	if (k == null || v == null || mf == null)
1529	>	throw new NullPointerException();
1530	>	int h = spread(k.hashCode());
1531	>	V val = null;
1532	>	int delta = 0;
1533	>	int len = 0;
1534	>	for (Node<V>[] tab = table;;) {
1535	>	int i; Node<V> f; Object fk; V fv;
1536	>	if (tab == null)
1537	>	tab = initTable();
1538	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1539	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1540	>	delta = 1;
1541	>	val = v;
1542	>	break;
1543		}
1544	<	return replaced;
1545	<	} finally {
1546	<	unlock();
1544	>	}
1545	>	else if (f.hash < 0) {
1546	>	if ((fk = f.key) instanceof TreeBin) {
1547	>	TreeBin<V> t = (TreeBin<V>)fk;
1548	>	t.acquire(0);
1549	>	try {
1550	>	if (tabAt(tab, i) == f) {
1551	>	len = 1;
1552	>	TreeNode<V> p = t.getTreeNode(h, k, t.root);
1553	>	val = (p == null) ? v : mf.apply(p.val, v);
1554	>	if (val != null) {
1555	>	if (p != null)
1556	>	p.val = val;
1557	>	else {
1558	>	len = 2;
1559	>	delta = 1;
1560	>	t.putTreeNode(h, k, val);
1561	>	}
1562	>	}
1563	>	else if (p != null) {
1564	>	delta = -1;
1565	>	t.deleteTreeNode(p);
1566	>	}
1567	>	}
1568	>	} finally {
1569	>	t.release(0);
1570	>	}
1571	>	if (len != 0)
1572	>	break;
1573	>	}
1574	>	else
1575	>	tab = (Node<V>[])fk;
1576	>	}
1577	>	else {
1578	>	synchronized (f) {
1579	>	if (tabAt(tab, i) == f) {
1580	>	len = 1;
1581	>	for (Node<V> e = f, pred = null;; ++len) {
1582	>	Object ek; V ev;
1583	>	if (e.hash == h &&
1584	>	(ev = e.val) != null &&
1585	>	((ek = e.key) == k || k.equals(ek))) {
1586	>	val = mf.apply(ev, v);
1587	>	if (val != null)
1588	>	e.val = val;
1589	>	else {
1590	>	delta = -1;
1591	>	Node<V> en = e.next;
1592	>	if (pred != null)
1593	>	pred.next = en;
1594	>	else
1595	>	setTabAt(tab, i, en);
1596	>	}
1597	>	break;
1598	>	}
1599	>	pred = e;
1600	>	if ((e = e.next) == null) {
1601	>	val = v;
1602	>	pred.next = new Node<V>(h, k, val, null);
1603	>	delta = 1;
1604	>	if (len >= TREE_THRESHOLD)
1605	>	replaceWithTreeBin(tab, i, k);
1606	>	break;
1607	>	}
1608	>	}
1609	>	}
1610	>	}
1611	>	if (len != 0)
1612	>	break;
1613		}
1614		}
1615	+	if (delta != 0)
1616	+	addCount((long)delta, len);
1617	+	return val;
1618	+	}
1619
1620	<	V replace(K key, int hash, V newValue) {
1621	<	lock();
1622	<	try {
1623	<	HashEntry<K,V> e = getFirst(hash);
1624	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1625	<	e = e.next;
1620	>	/** Implementation for putAll */
1621	>	@SuppressWarnings("unchecked") private final void internalPutAll
1622	>	(Map<? extends K, ? extends V> m) {
1623	>	tryPresize(m.size());
1624	>	long delta = 0L;     // number of uncommitted additions
1625	>	boolean npe = false; // to throw exception on exit for nulls
1626	>	try {                // to clean up counts on other exceptions
1627	>	for (Map.Entry<?, ? extends V> entry : m.entrySet()) {
1628	>	Object k; V v;
1629	>	if (entry == null || (k = entry.getKey()) == null ||
1630	>	(v = entry.getValue()) == null) {
1631	>	npe = true;
1632	>	break;
1633	>	}
1634	>	int h = spread(k.hashCode());
1635	>	for (Node<V>[] tab = table;;) {
1636	>	int i; Node<V> f; int fh; Object fk;
1637	>	if (tab == null)
1638	>	tab = initTable();
1639	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1640	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1641	>	++delta;
1642	>	break;
1643	>	}
1644	>	}
1645	>	else if ((fh = f.hash) < 0) {
1646	>	if ((fk = f.key) instanceof TreeBin) {
1647	>	TreeBin<V> t = (TreeBin<V>)fk;
1648	>	boolean validated = false;
1649	>	t.acquire(0);
1650	>	try {
1651	>	if (tabAt(tab, i) == f) {
1652	>	validated = true;
1653	>	TreeNode<V> p = t.getTreeNode(h, k, t.root);
1654	>	if (p != null)
1655	>	p.val = v;
1656	>	else {
1657	>	t.putTreeNode(h, k, v);
1658	>	++delta;
1659	>	}
1660	>	}
1661	>	} finally {
1662	>	t.release(0);
1663	>	}
1664	>	if (validated)
1665	>	break;
1666	>	}
1667	>	else
1668	>	tab = (Node<V>[])fk;
1669	>	}
1670	>	else {
1671	>	int len = 0;
1672	>	synchronized (f) {
1673	>	if (tabAt(tab, i) == f) {
1674	>	len = 1;
1675	>	for (Node<V> e = f;; ++len) {
1676	>	Object ek; V ev;
1677	>	if (e.hash == h &&
1678	>	(ev = e.val) != null &&
1679	>	((ek = e.key) == k || k.equals(ek))) {
1680	>	e.val = v;
1681	>	break;
1682	>	}
1683	>	Node<V> last = e;
1684	>	if ((e = e.next) == null) {
1685	>	++delta;
1686	>	last.next = new Node<V>(h, k, v, null);
1687	>	if (len >= TREE_THRESHOLD)
1688	>	replaceWithTreeBin(tab, i, k);
1689	>	break;
1690	>	}
1691	>	}
1692	>	}
1693	>	}
1694	>	if (len != 0) {
1695	>	if (len > 1) {
1696	>	addCount(delta, len);
1697	>	delta = 0L;
1698	>	}
1699	>	break;
1700	>	}
1701	>	}
1702	>	}
1703	>	}
1704	>	} finally {
1705	>	if (delta != 0L)
1706	>	addCount(delta, 2);
1707	>	}
1708	>	if (npe)
1709	>	throw new NullPointerException();
1710	>	}
1711
1712	<	V oldValue = null;
1713	<	if (e != null) {
1714	<	oldValue = e.value;
1715	<	e.value = newValue;
1712	>	/**
1713	>	* Implementation for clear. Steps through each bin, removing all
1714	>	* nodes.
1715	>	*/
1716	>	@SuppressWarnings("unchecked") private final void internalClear() {
1717	>	long delta = 0L; // negative number of deletions
1718	>	int i = 0;
1719	>	Node<V>[] tab = table;
1720	>	while (tab != null && i < tab.length) {
1721	>	Node<V> f = tabAt(tab, i);
1722	>	if (f == null)
1723	>	++i;
1724	>	else if (f.hash < 0) {
1725	>	Object fk;
1726	>	if ((fk = f.key) instanceof TreeBin) {
1727	>	TreeBin<V> t = (TreeBin<V>)fk;
1728	>	t.acquire(0);
1729	>	try {
1730	>	if (tabAt(tab, i) == f) {
1731	>	for (Node<V> p = t.first; p != null; p = p.next) {
1732	>	if (p.val != null) { // (currently always true)
1733	>	p.val = null;
1734	>	--delta;
1735	>	}
1736	>	}
1737	>	t.first = null;
1738	>	t.root = null;
1739	>	++i;
1740	>	}
1741	>	} finally {
1742	>	t.release(0);
1743	>	}
1744	>	}
1745	>	else
1746	>	tab = (Node<V>[])fk;
1747	>	}
1748	>	else {
1749	>	synchronized (f) {
1750	>	if (tabAt(tab, i) == f) {
1751	>	for (Node<V> e = f; e != null; e = e.next) {
1752	>	if (e.val != null) {  // (currently always true)
1753	>	e.val = null;
1754	>	--delta;
1755	>	}
1756	>	}
1757	>	setTabAt(tab, i, null);
1758	>	++i;
1759	>	}
1760		}
408	–	return oldValue;
409	–	} finally {
410	–	unlock();
1761		}
1762		}
1763	+	if (delta != 0L)
1764	+	addCount(delta, -1);
1765	+	}
1766
1767	+	/* ---------------- Table Initialization and Resizing -------------- */
1768
1769	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1770	<	lock();
1771	<	try {
1772	<	int c = count;
1773	<	if (c++ > threshold) // ensure capacity
1774	<	rehash();
1775	<	HashEntry<K,V>[] tab = table;
1776	<	int index = hash & (tab.length - 1);
1777	<	HashEntry<K,V> first = tab[index];
1778	<	HashEntry<K,V> e = first;
1779	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
1780	<	e = e.next;
1769	>	/**
1770	>	* Returns a power of two table size for the given desired capacity.
1771	>	* See Hackers Delight, sec 3.2
1772	>	*/
1773	>	private static final int tableSizeFor(int c) {
1774	>	int n = c - 1;
1775	>	n |= n >>> 1;
1776	>	n |= n >>> 2;
1777	>	n |= n >>> 4;
1778	>	n |= n >>> 8;
1779	>	n |= n >>> 16;
1780	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1781	>	}
1782
1783	<	V oldValue;
1784	<	if (e != null) {
1785	<	oldValue = e.value;
1786	<	if (!onlyIfAbsent)
1787	<	e.value = value;
1788	<	}
1789	<	else {
1790	<	oldValue = null;
1791	<	++modCount;
1792	<	tab[index] = new HashEntry<K,V>(key, hash, first, value);
1793	<	count = c; // write-volatile
1783	>	/**
1784	>	* Initializes table, using the size recorded in sizeCtl.
1785	>	*/
1786	>	@SuppressWarnings("unchecked") private final Node<V>[] initTable() {
1787	>	Node<V>[] tab; int sc;
1788	>	while ((tab = table) == null) {
1789	>	if ((sc = sizeCtl) < 0)
1790	>	Thread.yield(); // lost initialization race; just spin
1791	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1792	>	try {
1793	>	if ((tab = table) == null) {
1794	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1795	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1796	>	table = tab = (Node<V>[])tb;
1797	>	sc = n - (n >>> 2);
1798	>	}
1799	>	} finally {
1800	>	sizeCtl = sc;
1801		}
1802	<	return oldValue;
441	<	} finally {
442	<	unlock();
1802	>	break;
1803		}
1804		}
1805	+	return tab;
1806	+	}
1807
1808	<	void rehash() {
1809	<	HashEntry<K,V>[] oldTable = table;
1810	<	int oldCapacity = oldTable.length;
1811	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1808	>	/**
1809	>	* Adds to count, and if table is too small and not already
1810	>	* resizing, initiates transfer. If already resizing, helps
1811	>	* perform transfer if work is available.  Rechecks occupancy
1812	>	* after a transfer to see if another resize is already needed
1813	>	* because resizings are lagging additions.
1814	>	*
1815	>	* @param x the count to add
1816	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
1817	>	*/
1818	>	private final void addCount(long x, int check) {
1819	>	Cell[] as; long b, s;
1820	>	if ((as = counterCells) != null ||
1821	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1822	>	Cell a; long v; int m;
1823	>	boolean uncontended = true;
1824	>	if (as == null || (m = as.length - 1) < 0 ||
1825	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
1826	>	!(uncontended =
1827	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1828	>	fullAddCount(x, uncontended);
1829	>	return;
1830	>	}
1831	>	if (check <= 1)
1832		return;
1833	+	s = sumCount();
1834	+	}
1835	+	if (check >= 0) {
1836	+	Node<V>[] tab, nt; int sc;
1837	+	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1838	+	tab.length < MAXIMUM_CAPACITY) {
1839	+	if (sc < 0) {
1840	+	if (sc == -1 || transferIndex <= transferOrigin ||
1841	+	(nt = nextTable) == null)
1842	+	break;
1843	+	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1844	+	transfer(tab, nt);
1845	+	}
1846	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1847	+	transfer(tab, null);
1848	+	s = sumCount();
1849	+	}
1850	+	}
1851	+	}
1852
1853	<	/*
1854	<	* Reclassify nodes in each list to new Map.  Because we are
1855	<	* using power-of-two expansion, the elements from each bin
1856	<	* must either stay at same index, or move with a power of two
1857	<	* offset. We eliminate unnecessary node creation by catching
1858	<	* cases where old nodes can be reused because their next
1859	<	* fields won't change. Statistically, at the default
1860	<	* threshold, only about one-sixth of them need cloning when
1861	<	* a table doubles. The nodes they replace will be garbage
1862	<	* collectable as soon as they are no longer referenced by any
1863	<	* reader thread that may be in the midst of traversing table
1864	<	* right now.
1865	<	*/
1866	<
1867	<	HashEntry<K,V>[] newTable = HashEntry.newArray(oldCapacity<<1);
1868	<	threshold = (int)(newTable.length * loadFactor);
1869	<	int sizeMask = newTable.length - 1;
1870	<	for (int i = 0; i < oldCapacity ; i++) {
1871	<	// We need to guarantee that any existing reads of old Map can
1872	<	//  proceed. So we cannot yet null out each bin.
1873	<	HashEntry<K,V> e = oldTable[i];
1874	<
1875	<	if (e != null) {
1876	<	HashEntry<K,V> next = e.next;
1877	<	int idx = e.hash & sizeMask;
1878	<
1879	<	//  Single node on list
1880	<	if (next == null)
1881	<	newTable[idx] = e;
1853	>	/**
1854	>	* Tries to presize table to accommodate the given number of elements.
1855	>	*
1856	>	* @param size number of elements (doesn't need to be perfectly accurate)
1857	>	*/
1858	>	@SuppressWarnings("unchecked") private final void tryPresize(int size) {
1859	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1860	>	tableSizeFor(size + (size >>> 1) + 1);
1861	>	int sc;
1862	>	while ((sc = sizeCtl) >= 0) {
1863	>	Node<V>[] tab = table; int n;
1864	>	if (tab == null || (n = tab.length) == 0) {
1865	>	n = (sc > c) ? sc : c;
1866	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1867	>	try {
1868	>	if (table == tab) {
1869	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1870	>	table = (Node<V>[])tb;
1871	>	sc = n - (n >>> 2);
1872	>	}
1873	>	} finally {
1874	>	sizeCtl = sc;
1875	>	}
1876	>	}
1877	>	}
1878	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1879	>	break;
1880	>	else if (tab == table &&
1881	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
1882	>	transfer(tab, null);
1883	>	}
1884	>	}
1885
1886	<	else {
1887	<	// Reuse trailing consecutive sequence at same slot
1888	<	HashEntry<K,V> lastRun = e;
1889	<	int lastIdx = idx;
1890	<	for (HashEntry<K,V> last = next;
1891	<	last != null;
1892	<	last = last.next) {
1893	<	int k = last.hash & sizeMask;
1894	<	if (k != lastIdx) {
1895	<	lastIdx = k;
1896	<	lastRun = last;
1886	>	/**
1887	>	* Moves and/or copies the nodes in each bin to new table. See
1888	>	* above for explanation.
1889	>	*/
1890	>	@SuppressWarnings("unchecked") private final void transfer
1891	>	(Node<V>[] tab, Node<V>[] nextTab) {
1892	>	int n = tab.length, stride;
1893	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1894	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
1895	>	if (nextTab == null) {            // initiating
1896	>	try {
1897	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1];
1898	>	nextTab = (Node<V>[])tb;
1899	>	} catch (Throwable ex) {      // try to cope with OOME
1900	>	sizeCtl = Integer.MAX_VALUE;
1901	>	return;
1902	>	}
1903	>	nextTable = nextTab;
1904	>	transferOrigin = n;
1905	>	transferIndex = n;
1906	>	Node<V> rev = new Node<V>(MOVED, tab, null, null);
1907	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
1908	>	int nextk = (k > stride) ? k - stride : 0;
1909	>	for (int m = nextk; m < k; ++m)
1910	>	nextTab[m] = rev;
1911	>	for (int m = n + nextk; m < n + k; ++m)
1912	>	nextTab[m] = rev;
1913	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
1914	>	}
1915	>	}
1916	>	int nextn = nextTab.length;
1917	>	Node<V> fwd = new Node<V>(MOVED, nextTab, null, null);
1918	>	boolean advance = true;
1919	>	for (int i = 0, bound = 0;;) {
1920	>	int nextIndex, nextBound; Node<V> f; Object fk;
1921	>	while (advance) {
1922	>	if (--i >= bound)
1923	>	advance = false;
1924	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
1925	>	i = -1;
1926	>	advance = false;
1927	>	}
1928	>	else if (U.compareAndSwapInt
1929	>	(this, TRANSFERINDEX, nextIndex,
1930	>	nextBound = (nextIndex > stride ?
1931	>	nextIndex - stride : 0))) {
1932	>	bound = nextBound;
1933	>	i = nextIndex - 1;
1934	>	advance = false;
1935	>	}
1936	>	}
1937	>	if (i < 0 || i >= n || i + n >= nextn) {
1938	>	for (int sc;;) {
1939	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
1940	>	if (sc == -1) {
1941	>	nextTable = null;
1942	>	table = nextTab;
1943	>	sizeCtl = (n << 1) - (n >>> 1);
1944	>	}
1945	>	return;
1946	>	}
1947	>	}
1948	>	}
1949	>	else if ((f = tabAt(tab, i)) == null) {
1950	>	if (casTabAt(tab, i, null, fwd)) {
1951	>	setTabAt(nextTab, i, null);
1952	>	setTabAt(nextTab, i + n, null);
1953	>	advance = true;
1954	>	}
1955	>	}
1956	>	else if (f.hash >= 0) {
1957	>	synchronized (f) {
1958	>	if (tabAt(tab, i) == f) {
1959	>	int runBit = f.hash & n;
1960	>	Node<V> lastRun = f, lo = null, hi = null;
1961	>	for (Node<V> p = f.next; p != null; p = p.next) {
1962	>	int b = p.hash & n;
1963	>	if (b != runBit) {
1964	>	runBit = b;
1965	>	lastRun = p;
1966		}
1967		}
1968	<	newTable[lastIdx] = lastRun;
1969	<
1970	<	// Clone all remaining nodes
1971	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1972	<	int k = p.hash & sizeMask;
1973	<	HashEntry<K,V> n = newTable[k];
1974	<	newTable[k] = new HashEntry<K,V>(p.key, p.hash,
1975	<	n, p.value);
1968	>	if (runBit == 0)
1969	>	lo = lastRun;
1970	>	else
1971	>	hi = lastRun;
1972	>	for (Node<V> p = f; p != lastRun; p = p.next) {
1973	>	int ph = p.hash;
1974	>	Object pk = p.key; V pv = p.val;
1975	>	if ((ph & n) == 0)
1976	>	lo = new Node<V>(ph, pk, pv, lo);
1977	>	else
1978	>	hi = new Node<V>(ph, pk, pv, hi);
1979	>	}
1980	>	setTabAt(nextTab, i, lo);
1981	>	setTabAt(nextTab, i + n, hi);
1982	>	setTabAt(tab, i, fwd);
1983	>	advance = true;
1984	>	}
1985	>	}
1986	>	}
1987	>	else if ((fk = f.key) instanceof TreeBin) {
1988	>	TreeBin<V> t = (TreeBin<V>)fk;
1989	>	t.acquire(0);
1990	>	try {
1991	>	if (tabAt(tab, i) == f) {
1992	>	TreeBin<V> lt = new TreeBin<V>();
1993	>	TreeBin<V> ht = new TreeBin<V>();
1994	>	int lc = 0, hc = 0;
1995	>	for (Node<V> e = t.first; e != null; e = e.next) {
1996	>	int h = e.hash;
1997	>	Object k = e.key; V v = e.val;
1998	>	if ((h & n) == 0) {
1999	>	++lc;
2000	>	lt.putTreeNode(h, k, v);
2001	>	}
2002	>	else {
2003	>	++hc;
2004	>	ht.putTreeNode(h, k, v);
2005	>	}
2006	>	}
2007	>	Node<V> ln, hn; // throw away trees if too small
2008	>	if (lc < TREE_THRESHOLD) {
2009	>	ln = null;
2010	>	for (Node<V> p = lt.first; p != null; p = p.next)
2011	>	ln = new Node<V>(p.hash, p.key, p.val, ln);
2012		}
2013	+	else
2014	+	ln = new Node<V>(MOVED, lt, null, null);
2015	+	setTabAt(nextTab, i, ln);
2016	+	if (hc < TREE_THRESHOLD) {
2017	+	hn = null;
2018	+	for (Node<V> p = ht.first; p != null; p = p.next)
2019	+	hn = new Node<V>(p.hash, p.key, p.val, hn);
2020	+	}
2021	+	else
2022	+	hn = new Node<V>(MOVED, ht, null, null);
2023	+	setTabAt(nextTab, i + n, hn);
2024	+	setTabAt(tab, i, fwd);
2025	+	advance = true;
2026		}
2027	+	} finally {
2028	+	t.release(0);
2029		}
2030		}
2031	<	table = newTable;
2031	>	else
2032	>	advance = true; // already processed
2033		}
2034	+	}
2035
2036	<	/**
511	<	* Remove; match on key only if value null, else match both.
512	<	*/
513	<	V remove(Object key, int hash, Object value) {
514	<	lock();
515	<	try {
516	<	int c = count - 1;
517	<	HashEntry<K,V>[] tab = table;
518	<	int index = hash & (tab.length - 1);
519	<	HashEntry<K,V> first = tab[index];
520	<	HashEntry<K,V> e = first;
521	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
522	<	e = e.next;
2036	>	/* ---------------- Counter support -------------- */
2037
2038	<	V oldValue = null;
2039	<	if (e != null) {
2040	<	V v = e.value;
2041	<	if (value == null || value.equals(v)) {
2042	<	oldValue = v;
2043	<	// All entries following removed node can stay
2044	<	// in list, but all preceding ones need to be
531	<	// cloned.
532	<	++modCount;
533	<	HashEntry<K,V> newFirst = e.next;
534	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
535	<	newFirst = new HashEntry<K,V>(p.key, p.hash,
536	<	newFirst, p.value);
537	<	tab[index] = newFirst;
538	<	count = c; // write-volatile
539	<	}
540	<	}
541	<	return oldValue;
542	<	} finally {
543	<	unlock();
2038	>	final long sumCount() {
2039	>	Cell[] as = counterCells; Cell a;
2040	>	long sum = baseCount;
2041	>	if (as != null) {
2042	>	for (int i = 0; i < as.length; ++i) {
2043	>	if ((a = as[i]) != null)
2044	>	sum += a.value;
2045		}
2046		}
2047	+	return sum;
2048	+	}
2049
2050	<	void clear() {
2051	<	if (count != 0) {
2052	<	lock();
2053	<	try {
2054	<	HashEntry<K,V>[] tab = table;
2055	<	for (int i = 0; i < tab.length ; i++)
2056	<	tab[i] = null;
2057	<	++modCount;
2058	<	count = 0; // write-volatile
2050	>	// See LongAdder version for explanation
2051	>	private final void fullAddCount(long x, boolean wasUncontended) {
2052	>	int h;
2053	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2054	>	ThreadLocalRandom.localInit();      // force initialization
2055	>	h = ThreadLocalRandom.getProbe();
2056	>	wasUncontended = true;
2057	>	}
2058	>	boolean collide = false;                // True if last slot nonempty
2059	>	for (;;) {
2060	>	Cell[] as; Cell a; int n; long v;
2061	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2062	>	if ((a = as[(n - 1) & h]) == null) {
2063	>	if (cellsBusy == 0) {            // Try to attach new Cell
2064	>	Cell r = new Cell(x); // Optimistic create
2065	>	if (cellsBusy == 0 &&
2066	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2067	>	boolean created = false;
2068	>	try {               // Recheck under lock
2069	>	Cell[] rs; int m, j;
2070	>	if ((rs = counterCells) != null &&
2071	>	(m = rs.length) > 0 &&
2072	>	rs[j = (m - 1) & h] == null) {
2073	>	rs[j] = r;
2074	>	created = true;
2075	>	}
2076	>	} finally {
2077	>	cellsBusy = 0;
2078	>	}
2079	>	if (created)
2080	>	break;
2081	>	continue;           // Slot is now non-empty
2082	>	}
2083	>	}
2084	>	collide = false;
2085	>	}
2086	>	else if (!wasUncontended)       // CAS already known to fail
2087	>	wasUncontended = true;      // Continue after rehash
2088	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2089	>	break;
2090	>	else if (counterCells != as || n >= NCPU)
2091	>	collide = false;            // At max size or stale
2092	>	else if (!collide)
2093	>	collide = true;
2094	>	else if (cellsBusy == 0 &&
2095	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2096	>	try {
2097	>	if (counterCells == as) {// Expand table unless stale
2098	>	Cell[] rs = new Cell[n << 1];
2099	>	for (int i = 0; i < n; ++i)
2100	>	rs[i] = as[i];
2101	>	counterCells = rs;
2102	>	}
2103	>	} finally {
2104	>	cellsBusy = 0;
2105	>	}
2106	>	collide = false;
2107	>	continue;                   // Retry with expanded table
2108	>	}
2109	>	h = ThreadLocalRandom.advanceProbe(h);
2110	>	}
2111	>	else if (cellsBusy == 0 && counterCells == as &&
2112	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2113	>	boolean init = false;
2114	>	try {                           // Initialize table
2115	>	if (counterCells == as) {
2116	>	Cell[] rs = new Cell[2];
2117	>	rs[h & 1] = new Cell(x);
2118	>	counterCells = rs;
2119	>	init = true;
2120	>	}
2121		} finally {
2122	<	unlock();
2122	>	cellsBusy = 0;
2123		}
2124	+	if (init)
2125	+	break;
2126		}
2127	+	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2128	+	break;                          // Fall back on using base
2129		}
2130		}
2131
2132	+	/* ----------------Table Traversal -------------- */
2133
2134	+	/**
2135	+	* Encapsulates traversal for methods such as containsValue; also
2136	+	* serves as a base class for other iterators and bulk tasks.
2137	+	*
2138	+	* At each step, the iterator snapshots the key ("nextKey") and
2139	+	* value ("nextVal") of a valid node (i.e., one that, at point of
2140	+	* snapshot, has a non-null user value). Because val fields can
2141	+	* change (including to null, indicating deletion), field nextVal
2142	+	* might not be accurate at point of use, but still maintains the
2143	+	* weak consistency property of holding a value that was once
2144	+	* valid. To support iterator.remove, the nextKey field is not
2145	+	* updated (nulled out) when the iterator cannot advance.
2146	+	*
2147	+	* Internal traversals directly access these fields, as in:
2148	+	* {@code while (it.advance() != null) { process(it.nextKey); }}
2149	+	*
2150	+	* Exported iterators must track whether the iterator has advanced
2151	+	* (in hasNext vs next) (by setting/checking/nulling field
2152	+	* nextVal), and then extract key, value, or key-value pairs as
2153	+	* return values of next().
2154	+	*
2155	+	* The iterator visits once each still-valid node that was
2156	+	* reachable upon iterator construction. It might miss some that
2157	+	* were added to a bin after the bin was visited, which is OK wrt
2158	+	* consistency guarantees. Maintaining this property in the face
2159	+	* of possible ongoing resizes requires a fair amount of
2160	+	* bookkeeping state that is difficult to optimize away amidst
2161	+	* volatile accesses.  Even so, traversal maintains reasonable
2162	+	* throughput.
2163	+	*
2164	+	* Normally, iteration proceeds bin-by-bin traversing lists.
2165	+	* However, if the table has been resized, then all future steps
2166	+	* must traverse both the bin at the current index as well as at
2167	+	* (index + baseSize); and so on for further resizings. To
2168	+	* paranoically cope with potential sharing by users of iterators
2169	+	* across threads, iteration terminates if a bounds checks fails
2170	+	* for a table read.
2171	+	*
2172	+	* This class supports both Spliterator-based traversal and
2173	+	* CountedCompleter-based bulk tasks. The same "batch" field is
2174	+	* used, but in slightly different ways, in the two cases.  For
2175	+	* Spliterators, it is a saturating (at Integer.MAX_VALUE)
2176	+	* estimate of element coverage. For CHM tasks, it is a pre-scaled
2177	+	* size that halves down to zero for leaf tasks, that is only
2178	+	* computed upon execution of the task. (Tasks can be submitted to
2179	+	* any pool, of any size, so we don't know scale factors until
2180	+	* running.)
2181	+	*
2182	+	* This class extends CountedCompleter to streamline parallel
2183	+	* iteration in bulk operations. This adds only a few fields of
2184	+	* space overhead, which is small enough in cases where it is not
2185	+	* needed to not worry about it.  Because CountedCompleter is
2186	+	* Serializable, but iterators need not be, we need to add warning
2187	+	* suppressions.
2188	+	*/
2189	+	@SuppressWarnings("serial") static class Traverser<K,V,R>
2190	+	extends CountedCompleter<R> {
2191	+	final ConcurrentHashMap<K, V> map;
2192	+	Node<V> next;        // the next entry to use
2193	+	K nextKey;           // cached key field of next
2194	+	V nextVal;           // cached val field of next
2195	+	Node<V>[] tab;       // current table; updated if resized
2196	+	int index;           // index of bin to use next
2197	+	int baseIndex;       // current index of initial table
2198	+	int baseLimit;       // index bound for initial table
2199	+	int baseSize;        // initial table size
2200	+	int batch;           // split control
2201	+	/** Creates iterator for all entries in the table. */
2202	+	Traverser(ConcurrentHashMap<K, V> map) {
2203	+	this.map = map;
2204	+	Node<V>[] t;
2205	+	if ((t = tab = map.table) != null)
2206	+	baseLimit = baseSize = t.length;
2207	+	}
2208	+
2209	+	/** Task constructor */
2210	+	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it, int batch) {
2211	+	super(it);
2212	+	this.map = map;
2213	+	this.batch = batch; // -1 if unknown
2214	+	if (it == null) {
2215	+	Node<V>[] t;
2216	+	if ((t = tab = map.table) != null)
2217	+	baseLimit = baseSize = t.length;
2218	+	}
2219	+	else { // split parent
2220	+	this.tab = it.tab;
2221	+	this.baseSize = it.baseSize;
2222	+	int hi = this.baseLimit = it.baseLimit;
2223	+	it.baseLimit = this.index = this.baseIndex =
2224	+	(hi + it.baseIndex + 1) >>> 1;
2225	+	}
2226	+	}
2227	+
2228	+	/** Spliterator constructor */
2229	+	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it) {
2230	+	super(it);
2231	+	this.map = map;
2232	+	if (it == null) {
2233	+	Node<V>[] t;
2234	+	if ((t = tab = map.table) != null)
2235	+	baseLimit = baseSize = t.length;
2236	+	long n = map.sumCount();
2237	+	batch = ((n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2238	+	(int)n);
2239	+	}
2240	+	else {
2241	+	this.tab = it.tab;
2242	+	this.baseSize = it.baseSize;
2243	+	int hi = this.baseLimit = it.baseLimit;
2244	+	it.baseLimit = this.index = this.baseIndex =
2245	+	(hi + it.baseIndex + 1) >>> 1;
2246	+	this.batch = it.batch >>>= 1;
2247	+	}
2248	+	}
2249	+
2250	+	/**
2251	+	* Advances next; returns nextVal or null if terminated.
2252	+	* See above for explanation.
2253	+	*/
2254	+	@SuppressWarnings("unchecked") final V advance() {
2255	+	Node<V> e = next;
2256	+	V ev = null;
2257	+	outer: do {
2258	+	if (e != null)                  // advance past used/skipped node
2259	+	e = e.next;
2260	+	while (e == null) {             // get to next non-null bin
2261	+	ConcurrentHashMap<K, V> m;
2262	+	Node<V>[] t; int b, i, n; Object ek; //  must use locals
2263	+	if ((t = tab) != null)
2264	+	n = t.length;
2265	+	else if ((m = map) != null && (t = tab = m.table) != null)
2266	+	n = baseLimit = baseSize = t.length;
2267	+	else
2268	+	break outer;
2269	+	if ((b = baseIndex) >= baseLimit ||
2270	+	(i = index) < 0 || i >= n)
2271	+	break outer;
2272	+	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2273	+	if ((ek = e.key) instanceof TreeBin)
2274	+	e = ((TreeBin<V>)ek).first;
2275	+	else {
2276	+	tab = (Node<V>[])ek;
2277	+	continue;           // restarts due to null val
2278	+	}
2279	+	}                           // visit upper slots if present
2280	+	index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2281	+	}
2282	+	nextKey = (K)e.key;
2283	+	} while ((ev = e.val) == null);    // skip deleted or special nodes
2284	+	next = e;
2285	+	return nextVal = ev;
2286	+	}
2287	+
2288	+	public final void remove() {
2289	+	K k = nextKey;
2290	+	if (k == null && (advance() == null || (k = nextKey) == null))
2291	+	throw new IllegalStateException();
2292	+	map.internalReplace(k, null, null);
2293	+	}
2294	+
2295	+	public final boolean hasNext() {
2296	+	return nextVal != null || advance() != null;
2297	+	}
2298	+
2299	+	public final boolean hasMoreElements() { return hasNext(); }
2300	+
2301	+	public void compute() { } // default no-op CountedCompleter body
2302	+
2303	+	/**
2304	+	* Returns a batch value > 0 if this task should (and must) be
2305	+	* split, if so, adding to pending count, and in any case
2306	+	* updating batch value. The initial batch value is approx
2307	+	* exp2 of the number of times (minus one) to split task by
2308	+	* two before executing leaf action. This value is faster to
2309	+	* compute and more convenient to use as a guide to splitting
2310	+	* than is the depth, since it is used while dividing by two
2311	+	* anyway.
2312	+	*/
2313	+	final int preSplit() {
2314	+	int b;  ForkJoinPool pool;
2315	+	if ((b = batch) < 0) { // force initialization
2316	+	int sp = (((pool = getPool()) == null) ?
2317	+	ForkJoinPool.getCommonPoolParallelism() :
2318	+	pool.getParallelism()) << 3; // slack of 8
2319	+	long n = map.sumCount();
2320	+	b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2321	+	}
2322	+	b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1);
2323	+	if ((batch = b) > 0)
2324	+	addToPendingCount(1);
2325	+	return b;
2326	+	}
2327	+
2328	+	// spliterator support
2329	+
2330	+	public boolean hasExactSize() {
2331	+	return false;
2332	+	}
2333	+
2334	+	public boolean hasExactSplits() {
2335	+	return false;
2336	+	}
2337	+
2338	+	public long estimateSize() {
2339	+	return batch;
2340	+	}
2341	+	}
2342
2343		/* ---------------- Public operations -------------- */
2344
2345		/**
2346	<	* Creates a new, empty map with the specified initial
2347	<	* capacity, load factor and concurrency level.
2346	>	* Creates a new, empty map with the default initial table size (16).
2347	>	*/
2348	>	public ConcurrentHashMap() {
2349	>	}
2350	>
2351	>	/**
2352	>	* Creates a new, empty map with an initial table size
2353	>	* accommodating the specified number of elements without the need
2354	>	* to dynamically resize.
2355		*
2356	<	* @param initialCapacity the initial capacity. The implementation
2357	<	* performs internal sizing to accommodate this many elements.
2358	<	* @param loadFactor  the load factor threshold, used to control resizing.
2359	<	* Resizing may be performed when the average number of elements per
575	<	* bin exceeds this threshold.
576	<	* @param concurrencyLevel the estimated number of concurrently
577	<	* updating threads. The implementation performs internal sizing
578	<	* to try to accommodate this many threads.
579	<	* @throws IllegalArgumentException if the initial capacity is
580	<	* negative or the load factor or concurrencyLevel are
581	<	* nonpositive.
2356	>	* @param initialCapacity The implementation performs internal
2357	>	* sizing to accommodate this many elements.
2358	>	* @throws IllegalArgumentException if the initial capacity of
2359	>	* elements is negative
2360		*/
2361	<	public ConcurrentHashMap(int initialCapacity,
2362	<	float loadFactor, int concurrencyLevel) {
585	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2361	>	public ConcurrentHashMap(int initialCapacity) {
2362	>	if (initialCapacity < 0)
2363		throw new IllegalArgumentException();
2364	+	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2365	+	MAXIMUM_CAPACITY :
2366	+	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2367	+	this.sizeCtl = cap;
2368	+	}
2369
2370	<	if (concurrencyLevel > MAX_SEGMENTS)
2371	<	concurrencyLevel = MAX_SEGMENTS;
2372	<
2373	<	// Find power-of-two sizes best matching arguments
2374	<	int sshift = 0;
2375	<	int ssize = 1;
2376	<	while (ssize < concurrencyLevel) {
2377	<	++sshift;
596	<	ssize <<= 1;
597	<	}
598	<	segmentShift = 32 - sshift;
599	<	segmentMask = ssize - 1;
600	<	this.segments = Segment.newArray(ssize);
601	<
602	<	if (initialCapacity > MAXIMUM_CAPACITY)
603	<	initialCapacity = MAXIMUM_CAPACITY;
604	<	int c = initialCapacity / ssize;
605	<	if (c * ssize < initialCapacity)
606	<	++c;
607	<	int cap = 1;
608	<	while (cap < c)
609	<	cap <<= 1;
610	<
611	<	for (int i = 0; i < this.segments.length; ++i)
612	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2370	>	/**
2371	>	* Creates a new map with the same mappings as the given map.
2372	>	*
2373	>	* @param m the map
2374	>	*/
2375	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2376	>	this.sizeCtl = DEFAULT_CAPACITY;
2377	>	internalPutAll(m);
2378		}
2379
2380		/**
2381	<	* Creates a new, empty map with the specified initial capacity
2382	<	* and load factor and with the default concurrencyLevel (16).
2381	>	* Creates a new, empty map with an initial table size based on
2382	>	* the given number of elements ({@code initialCapacity}) and
2383	>	* initial table density ({@code loadFactor}).
2384		*
2385	<	* @param initialCapacity The implementation performs internal
2386	<	* sizing to accommodate this many elements.
2387	<	* @param loadFactor  the load factor threshold, used to control resizing.
2388	<	* Resizing may be performed when the average number of elements per
2389	<	* bin exceeds this threshold.
2385	>	* @param initialCapacity the initial capacity. The implementation
2386	>	* performs internal sizing to accommodate this many elements,
2387	>	* given the specified load factor.
2388	>	* @param loadFactor the load factor (table density) for
2389	>	* establishing the initial table size
2390		* @throws IllegalArgumentException if the initial capacity of
2391		* elements is negative or the load factor is nonpositive
2392		*
2393		* @since 1.6
2394		*/
2395		public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2396	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
2396	>	this(initialCapacity, loadFactor, 1);
2397		}
2398
2399		/**
2400	<	* Creates a new, empty map with the specified initial capacity,
2401	<	* and with default load factor (0.75) and concurrencyLevel (16).
2400	>	* Creates a new, empty map with an initial table size based on
2401	>	* the given number of elements ({@code initialCapacity}), table
2402	>	* density ({@code loadFactor}), and number of concurrently
2403	>	* updating threads ({@code concurrencyLevel}).
2404		*
2405		* @param initialCapacity the initial capacity. The implementation
2406	<	* performs internal sizing to accommodate this many elements.
2407	<	* @throws IllegalArgumentException if the initial capacity of
2408	<	* elements is negative.
2406	>	* performs internal sizing to accommodate this many elements,
2407	>	* given the specified load factor.
2408	>	* @param loadFactor the load factor (table density) for
2409	>	* establishing the initial table size
2410	>	* @param concurrencyLevel the estimated number of concurrently
2411	>	* updating threads. The implementation may use this value as
2412	>	* a sizing hint.
2413	>	* @throws IllegalArgumentException if the initial capacity is
2414	>	* negative or the load factor or concurrencyLevel are
2415	>	* nonpositive
2416		*/
2417	<	public ConcurrentHashMap(int initialCapacity) {
2418	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2417	>	public ConcurrentHashMap(int initialCapacity,
2418	>	float loadFactor, int concurrencyLevel) {
2419	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2420	>	throw new IllegalArgumentException();
2421	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2422	>	initialCapacity = concurrencyLevel;   // as estimated threads
2423	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2424	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2425	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2426	>	this.sizeCtl = cap;
2427		}
2428
2429		/**
2430	<	* Creates a new, empty map with a default initial capacity (16),
2431	<	* load factor (0.75) and concurrencyLevel (16).
2430	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2431	>	* from the given type to {@code Boolean.TRUE}.
2432	>	*
2433	>	* @return the new set
2434		*/
2435	<	public ConcurrentHashMap() {
2436	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2435	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2436	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(),
2437	>	Boolean.TRUE);
2438		}
2439
2440		/**
2441	<	* Creates a new map with the same mappings as the given map.
2442	<	* The map is created with a capacity of 1.5 times the number
657	<	* of mappings in the given map or 16 (whichever is greater),
658	<	* and a default load factor (0.75) and concurrencyLevel (16).
2441	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2442	>	* from the given type to {@code Boolean.TRUE}.
2443		*
2444	<	* @param m the map
2444	>	* @param initialCapacity The implementation performs internal
2445	>	* sizing to accommodate this many elements.
2446	>	* @throws IllegalArgumentException if the initial capacity of
2447	>	* elements is negative
2448	>	* @return the new set
2449		*/
2450	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2451	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
2452	<	DEFAULT_INITIAL_CAPACITY),
665	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
666	<	putAll(m);
2450	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2451	>	return new KeySetView<K,Boolean>
2452	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2453		}
2454
2455		/**
2456	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
671	<	*
672	<	* @return <tt>true</tt> if this map contains no key-value mappings
2456	>	* {@inheritDoc}
2457		*/
2458		public boolean isEmpty() {
2459	<	final Segment<K,V>[] segments = this.segments;
676	<	/*
677	<	* We keep track of per-segment modCounts to avoid ABA
678	<	* problems in which an element in one segment was added and
679	<	* in another removed during traversal, in which case the
680	<	* table was never actually empty at any point. Note the
681	<	* similar use of modCounts in the size() and containsValue()
682	<	* methods, which are the only other methods also susceptible
683	<	* to ABA problems.
684	<	*/
685	<	int[] mc = new int[segments.length];
686	<	int mcsum = 0;
687	<	for (int i = 0; i < segments.length; ++i) {
688	<	if (segments[i].count != 0)
689	<	return false;
690	<	else
691	<	mcsum += mc[i] = segments[i].modCount;
692	<	}
693	<	// If mcsum happens to be zero, then we know we got a snapshot
694	<	// before any modifications at all were made.  This is
695	<	// probably common enough to bother tracking.
696	<	if (mcsum != 0) {
697	<	for (int i = 0; i < segments.length; ++i) {
698	<	if (segments[i].count != 0 ||
699	<	mc[i] != segments[i].modCount)
700	<	return false;
701	<	}
702	<	}
703	<	return true;
2459	>	return sumCount() <= 0L; // ignore transient negative values
2460		}
2461
2462		/**
2463	<	* Returns the number of key-value mappings in this map.  If the
708	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
709	<	* <tt>Integer.MAX_VALUE</tt>.
710	<	*
711	<	* @return the number of key-value mappings in this map
2463	>	* {@inheritDoc}
2464		*/
2465		public int size() {
2466	<	final Segment<K,V>[] segments = this.segments;
2467	<	long sum = 0;
2468	<	long check = 0;
2469	<	int[] mc = new int[segments.length];
2470	<	// Try a few times to get accurate count. On failure due to
2471	<	// continuous async changes in table, resort to locking.
2472	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
2473	<	check = 0;
2474	<	sum = 0;
2475	<	int mcsum = 0;
2476	<	for (int i = 0; i < segments.length; ++i) {
2477	<	sum += segments[i].count;
2478	<	mcsum += mc[i] = segments[i].modCount;
2479	<	}
2480	<	if (mcsum != 0) {
2481	<	for (int i = 0; i < segments.length; ++i) {
2482	<	check += segments[i].count;
2483	<	if (mc[i] != segments[i].modCount) {
732	<	check = -1; // force retry
733	<	break;
734	<	}
735	<	}
736	<	}
737	<	if (check == sum)
738	<	break;
739	<	}
740	<	if (check != sum) { // Resort to locking all segments
741	<	sum = 0;
742	<	for (int i = 0; i < segments.length; ++i)
743	<	segments[i].lock();
744	<	for (int i = 0; i < segments.length; ++i)
745	<	sum += segments[i].count;
746	<	for (int i = 0; i < segments.length; ++i)
747	<	segments[i].unlock();
748	<	}
749	<	if (sum > Integer.MAX_VALUE)
750	<	return Integer.MAX_VALUE;
751	<	else
752	<	return (int)sum;
2466	>	long n = sumCount();
2467	>	return ((n < 0L) ? 0 :
2468	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2469	>	(int)n);
2470	>	}
2471	>
2472	>	/**
2473	>	* Returns the number of mappings. This method should be used
2474	>	* instead of {@link #size} because a ConcurrentHashMap may
2475	>	* contain more mappings than can be represented as an int. The
2476	>	* value returned is an estimate; the actual count may differ if
2477	>	* there are concurrent insertions or removals.
2478	>	*
2479	>	* @return the number of mappings
2480	>	*/
2481	>	public long mappingCount() {
2482	>	long n = sumCount();
2483	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2484		}
2485
2486		/**
#	Line 764 | Line 2495 | public class ConcurrentHashMap<K, V> ext
2495		* @throws NullPointerException if the specified key is null
2496		*/
2497		public V get(Object key) {
2498	<	int hash = hash(key.hashCode());
2499	<	return segmentFor(hash).get(key, hash);
2498	>	return internalGet(key);
2499	>	}
2500	>
2501	>	/**
2502	>	* Returns the value to which the specified key is mapped,
2503	>	* or the given defaultValue if this map contains no mapping for the key.
2504	>	*
2505	>	* @param key the key
2506	>	* @param defaultValue the value to return if this map contains
2507	>	* no mapping for the given key
2508	>	* @return the mapping for the key, if present; else the defaultValue
2509	>	* @throws NullPointerException if the specified key is null
2510	>	*/
2511	>	public V getValueOrDefault(Object key, V defaultValue) {
2512	>	V v;
2513	>	return (v = internalGet(key)) == null ? defaultValue : v;
2514		}
2515
2516		/**
2517		* Tests if the specified object is a key in this table.
2518		*
2519		* @param  key   possible key
2520	<	* @return <tt>true</tt> if and only if the specified object
2520	>	* @return {@code true} if and only if the specified object
2521		*         is a key in this table, as determined by the
2522	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
2522	>	*         {@code equals} method; {@code false} otherwise
2523		* @throws NullPointerException if the specified key is null
2524		*/
2525		public boolean containsKey(Object key) {
2526	<	int hash = hash(key.hashCode());
782	<	return segmentFor(hash).containsKey(key, hash);
2526	>	return internalGet(key) != null;
2527		}
2528
2529		/**
2530	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2531	<	* specified value. Note: This method requires a full internal
2532	<	* traversal of the hash table, and so is much slower than
789	<	* method <tt>containsKey</tt>.
2530	>	* Returns {@code true} if this map maps one or more keys to the
2531	>	* specified value. Note: This method may require a full traversal
2532	>	* of the map, and is much slower than method {@code containsKey}.
2533		*
2534		* @param value value whose presence in this map is to be tested
2535	<	* @return <tt>true</tt> if this map maps one or more keys to the
2535	>	* @return {@code true} if this map maps one or more keys to the
2536		*         specified value
2537		* @throws NullPointerException if the specified value is null
2538		*/
2539		public boolean containsValue(Object value) {
2540		if (value == null)
2541		throw new NullPointerException();
2542	<
2543	<	// See explanation of modCount use above
2544	<
2545	<	final Segment<K,V>[] segments = this.segments;
2546	<	int[] mc = new int[segments.length];
804	<
805	<	// Try a few times without locking
806	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
807	<	int sum = 0;
808	<	int mcsum = 0;
809	<	for (int i = 0; i < segments.length; ++i) {
810	<	int c = segments[i].count;
811	<	mcsum += mc[i] = segments[i].modCount;
812	<	if (segments[i].containsValue(value))
813	<	return true;
814	<	}
815	<	boolean cleanSweep = true;
816	<	if (mcsum != 0) {
817	<	for (int i = 0; i < segments.length; ++i) {
818	<	int c = segments[i].count;
819	<	if (mc[i] != segments[i].modCount) {
820	<	cleanSweep = false;
821	<	break;
822	<	}
823	<	}
824	<	}
825	<	if (cleanSweep)
826	<	return false;
2542	>	V v;
2543	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2544	>	while ((v = it.advance()) != null) {
2545	>	if (v == value || value.equals(v))
2546	>	return true;
2547		}
2548	<	// Resort to locking all segments
829	<	for (int i = 0; i < segments.length; ++i)
830	<	segments[i].lock();
831	<	boolean found = false;
832	<	try {
833	<	for (int i = 0; i < segments.length; ++i) {
834	<	if (segments[i].containsValue(value)) {
835	<	found = true;
836	<	break;
837	<	}
838	<	}
839	<	} finally {
840	<	for (int i = 0; i < segments.length; ++i)
841	<	segments[i].unlock();
842	<	}
843	<	return found;
2548	>	return false;
2549		}
2550
2551		/**
#	Line 850 | Line 2555 | public class ConcurrentHashMap<K, V> ext
2555		* full compatibility with class {@link java.util.Hashtable},
2556		* which supported this method prior to introduction of the
2557		* Java Collections framework.
2558	<
2558	>	*
2559		* @param  value a value to search for
2560	<	* @return <tt>true</tt> if and only if some key maps to the
2561	<	*         <tt>value</tt> argument in this table as
2562	<	*         determined by the <tt>equals</tt> method;
2563	<	*         <tt>false</tt> otherwise
2560	>	* @return {@code true} if and only if some key maps to the
2561	>	*         {@code value} argument in this table as
2562	>	*         determined by the {@code equals} method;
2563	>	*         {@code false} otherwise
2564		* @throws NullPointerException if the specified value is null
2565		*/
2566	<	public boolean contains(Object value) {
2566	>	@Deprecated public boolean contains(Object value) {
2567		return containsValue(value);
2568		}
2569
#	Line 866 | Line 2571 | public class ConcurrentHashMap<K, V> ext
2571		* Maps the specified key to the specified value in this table.
2572		* Neither the key nor the value can be null.
2573		*
2574	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
2574	>	* <p>The value can be retrieved by calling the {@code get} method
2575		* with a key that is equal to the original key.
2576		*
2577		* @param key key with which the specified value is to be associated
2578		* @param value value to be associated with the specified key
2579	<	* @return the previous value associated with <tt>key</tt>, or
2580	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2579	>	* @return the previous value associated with {@code key}, or
2580	>	*         {@code null} if there was no mapping for {@code key}
2581		* @throws NullPointerException if the specified key or value is null
2582		*/
2583		public V put(K key, V value) {
2584	<	if (value == null)
880	<	throw new NullPointerException();
881	<	int hash = hash(key.hashCode());
882	<	return segmentFor(hash).put(key, hash, value, false);
2584	>	return internalPut(key, value, false);
2585		}
2586
2587		/**
2588		* {@inheritDoc}
2589		*
2590		* @return the previous value associated with the specified key,
2591	<	*         or <tt>null</tt> if there was no mapping for the key
2591	>	*         or {@code null} if there was no mapping for the key
2592		* @throws NullPointerException if the specified key or value is null
2593		*/
2594		public V putIfAbsent(K key, V value) {
2595	<	if (value == null)
894	<	throw new NullPointerException();
895	<	int hash = hash(key.hashCode());
896	<	return segmentFor(hash).put(key, hash, value, true);
2595	>	return internalPut(key, value, true);
2596		}
2597
2598		/**
#	Line 904 | Line 2603 | public class ConcurrentHashMap<K, V> ext
2603		* @param m mappings to be stored in this map
2604		*/
2605		public void putAll(Map<? extends K, ? extends V> m) {
2606	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2607	<	put(e.getKey(), e.getValue());
2606	>	internalPutAll(m);
2607	>	}
2608	>
2609	>	/**
2610	>	* If the specified key is not already associated with a value (or
2611	>	* is mapped to {@code null}), attempts to compute its value using
2612	>	* the given mapping function and enters it into this map unless
2613	>	* {@code null}. The entire method invocation is performed
2614	>	* atomically, so the function is applied at most once per key.
2615	>	* Some attempted update operations on this map by other threads
2616	>	* may be blocked while computation is in progress, so the
2617	>	* computation should be short and simple, and must not attempt to
2618	>	* update any other mappings of this Map.
2619	>	*
2620	>	* @param key key with which the specified value is to be associated
2621	>	* @param mappingFunction the function to compute a value
2622	>	* @return the current (existing or computed) value associated with
2623	>	*         the specified key, or null if the computed value is null
2624	>	* @throws NullPointerException if the specified key or mappingFunction
2625	>	*         is null
2626	>	* @throws IllegalStateException if the computation detectably
2627	>	*         attempts a recursive update to this map that would
2628	>	*         otherwise never complete
2629	>	* @throws RuntimeException or Error if the mappingFunction does so,
2630	>	*         in which case the mapping is left unestablished
2631	>	*/
2632	>	public V computeIfAbsent
2633	>	(K key, Function<? super K, ? extends V> mappingFunction) {
2634	>	return internalComputeIfAbsent(key, mappingFunction);
2635	>	}
2636	>
2637	>	/**
2638	>	* If the value for the specified key is present and non-null,
2639	>	* attempts to compute a new mapping given the key and its current
2640	>	* mapped value.  The entire method invocation is performed
2641	>	* atomically.  Some attempted update operations on this map by
2642	>	* other threads may be blocked while computation is in progress,
2643	>	* so the computation should be short and simple, and must not
2644	>	* attempt to update any other mappings of this Map.
2645	>	*
2646	>	* @param key key with which the specified value is to be associated
2647	>	* @param remappingFunction the function to compute a value
2648	>	* @return the new value associated with the specified key, or null if none
2649	>	* @throws NullPointerException if the specified key or remappingFunction
2650	>	*         is null
2651	>	* @throws IllegalStateException if the computation detectably
2652	>	*         attempts a recursive update to this map that would
2653	>	*         otherwise never complete
2654	>	* @throws RuntimeException or Error if the remappingFunction does so,
2655	>	*         in which case the mapping is unchanged
2656	>	*/
2657	>	public V computeIfPresent
2658	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2659	>	return internalCompute(key, true, remappingFunction);
2660	>	}
2661	>
2662	>	/**
2663	>	* Attempts to compute a mapping for the specified key and its
2664	>	* current mapped value (or {@code null} if there is no current
2665	>	* mapping). The entire method invocation is performed atomically.
2666	>	* Some attempted update operations on this map by other threads
2667	>	* may be blocked while computation is in progress, so the
2668	>	* computation should be short and simple, and must not attempt to
2669	>	* update any other mappings of this Map.
2670	>	*
2671	>	* @param key key with which the specified value is to be associated
2672	>	* @param remappingFunction the function to compute a value
2673	>	* @return the new value associated with the specified key, or null if none
2674	>	* @throws NullPointerException if the specified key or remappingFunction
2675	>	*         is null
2676	>	* @throws IllegalStateException if the computation detectably
2677	>	*         attempts a recursive update to this map that would
2678	>	*         otherwise never complete
2679	>	* @throws RuntimeException or Error if the remappingFunction does so,
2680	>	*         in which case the mapping is unchanged
2681	>	*/
2682	>	public V compute
2683	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2684	>	return internalCompute(key, false, remappingFunction);
2685	>	}
2686	>
2687	>	/**
2688	>	* If the specified key is not already associated with a
2689	>	* (non-null) value, associates it with the given value.
2690	>	* Otherwise, replaces the value with the results of the given
2691	>	* remapping function, or removes if {@code null}. The entire
2692	>	* method invocation is performed atomically.  Some attempted
2693	>	* update operations on this map by other threads may be blocked
2694	>	* while computation is in progress, so the computation should be
2695	>	* short and simple, and must not attempt to update any other
2696	>	* mappings of this Map.
2697	>	*
2698	>	* @param key key with which the specified value is to be associated
2699	>	* @param value the value to use if absent
2700	>	* @param remappingFunction the function to recompute a value if present
2701	>	* @return the new value associated with the specified key, or null if none
2702	>	* @throws NullPointerException if the specified key or the
2703	>	*         remappingFunction is null
2704	>	* @throws RuntimeException or Error if the remappingFunction does so,
2705	>	*         in which case the mapping is unchanged
2706	>	*/
2707	>	public V merge
2708	>	(K key, V value,
2709	>	BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2710	>	return internalMerge(key, value, remappingFunction);
2711		}
2712
2713		/**
#	Line 913 | Line 2715 | public class ConcurrentHashMap<K, V> ext
2715		* This method does nothing if the key is not in the map.
2716		*
2717		* @param  key the key that needs to be removed
2718	<	* @return the previous value associated with <tt>key</tt>, or
2719	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2718	>	* @return the previous value associated with {@code key}, or
2719	>	*         {@code null} if there was no mapping for {@code key}
2720		* @throws NullPointerException if the specified key is null
2721		*/
2722		public V remove(Object key) {
2723	<	int hash = hash(key.hashCode());
922	<	return segmentFor(hash).remove(key, hash, null);
2723	>	return internalReplace(key, null, null);
2724		}
2725
2726		/**
#	Line 928 | Line 2729 | public class ConcurrentHashMap<K, V> ext
2729		* @throws NullPointerException if the specified key is null
2730		*/
2731		public boolean remove(Object key, Object value) {
2732	<	int hash = hash(key.hashCode());
2733	<	if (value == null)
2734	<	return false;
934	<	return segmentFor(hash).remove(key, hash, value) != null;
2732	>	if (key == null)
2733	>	throw new NullPointerException();
2734	>	return value != null && internalReplace(key, null, value) != null;
2735		}
2736
2737		/**
#	Line 940 | Line 2740 | public class ConcurrentHashMap<K, V> ext
2740		* @throws NullPointerException if any of the arguments are null
2741		*/
2742		public boolean replace(K key, V oldValue, V newValue) {
2743	<	if (oldValue == null || newValue == null)
2743	>	if (key == null || oldValue == null || newValue == null)
2744		throw new NullPointerException();
2745	<	int hash = hash(key.hashCode());
946	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
2745	>	return internalReplace(key, newValue, oldValue) != null;
2746		}
2747
2748		/**
2749		* {@inheritDoc}
2750		*
2751		* @return the previous value associated with the specified key,
2752	<	*         or <tt>null</tt> if there was no mapping for the key
2752	>	*         or {@code null} if there was no mapping for the key
2753		* @throws NullPointerException if the specified key or value is null
2754		*/
2755		public V replace(K key, V value) {
2756	<	if (value == null)
2756	>	if (key == null || value == null)
2757		throw new NullPointerException();
2758	<	int hash = hash(key.hashCode());
960	<	return segmentFor(hash).replace(key, hash, value);
2758	>	return internalReplace(key, value, null);
2759		}
2760
2761		/**
2762		* Removes all of the mappings from this map.
2763		*/
2764		public void clear() {
2765	<	for (int i = 0; i < segments.length; ++i)
968	<	segments[i].clear();
2765	>	internalClear();
2766		}
2767
2768		/**
2769		* Returns a {@link Set} view of the keys contained in this map.
2770		* The set is backed by the map, so changes to the map are
2771	<	* reflected in the set, and vice-versa.  The set supports element
975	<	* removal, which removes the corresponding mapping from this map,
976	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
977	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
978	<	* operations.  It does not support the <tt>add</tt> or
979	<	* <tt>addAll</tt> operations.
2771	>	* reflected in the set, and vice-versa.
2772		*
2773	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
982	<	* that will never throw {@link ConcurrentModificationException},
983	<	* and guarantees to traverse elements as they existed upon
984	<	* construction of the iterator, and may (but is not guaranteed to)
985	<	* reflect any modifications subsequent to construction.
2773	>	* @return the set view
2774		*/
2775	<	public Set<K> keySet() {
2776	<	Set<K> ks = keySet;
2777	<	return (ks != null) ? ks : (keySet = new KeySet());
2775	>	public KeySetView<K,V> keySet() {
2776	>	KeySetView<K,V> ks = keySet;
2777	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2778	>	}
2779	>
2780	>	/**
2781	>	* Returns a {@link Set} view of the keys in this map, using the
2782	>	* given common mapped value for any additions (i.e., {@link
2783	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2784	>	* This is of course only appropriate if it is acceptable to use
2785	>	* the same value for all additions from this view.
2786	>	*
2787	>	* @param mappedValue the mapped value to use for any additions
2788	>	* @return the set view
2789	>	* @throws NullPointerException if the mappedValue is null
2790	>	*/
2791	>	public KeySetView<K,V> keySet(V mappedValue) {
2792	>	if (mappedValue == null)
2793	>	throw new NullPointerException();
2794	>	return new KeySetView<K,V>(this, mappedValue);
2795		}
2796
2797		/**
2798		* Returns a {@link Collection} view of the values contained in this map.
2799		* The collection is backed by the map, so changes to the map are
2800	<	* reflected in the collection, and vice-versa.  The collection
996	<	* supports element removal, which removes the corresponding
997	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
998	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
999	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1000	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1001	<	*
1002	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1003	<	* that will never throw {@link ConcurrentModificationException},
1004	<	* and guarantees to traverse elements as they existed upon
1005	<	* construction of the iterator, and may (but is not guaranteed to)
1006	<	* reflect any modifications subsequent to construction.
2800	>	* reflected in the collection, and vice-versa.
2801		*/
2802	<	public Collection<V> values() {
2803	<	Collection<V> vs = values;
2804	<	return (vs != null) ? vs : (values = new Values());
2802	>	public ValuesView<K,V> values() {
2803	>	ValuesView<K,V> vs = values;
2804	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2805		}
2806
2807		/**
#	Line 1015 | Line 2809 | public class ConcurrentHashMap<K, V> ext
2809		* The set is backed by the map, so changes to the map are
2810		* reflected in the set, and vice-versa.  The set supports element
2811		* removal, which removes the corresponding mapping from the map,
2812	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2813	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2814	<	* operations.  It does not support the <tt>add</tt> or
2815	<	* <tt>addAll</tt> operations.
2812	>	* via the {@code Iterator.remove}, {@code Set.remove},
2813	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2814	>	* operations.  It does not support the {@code add} or
2815	>	* {@code addAll} operations.
2816		*
2817	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2817	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2818		* that will never throw {@link ConcurrentModificationException},
2819		* and guarantees to traverse elements as they existed upon
2820		* construction of the iterator, and may (but is not guaranteed to)
2821		* reflect any modifications subsequent to construction.
2822		*/
2823		public Set<Map.Entry<K,V>> entrySet() {
2824	<	Set<Map.Entry<K,V>> es = entrySet;
2825	<	return (es != null) ? es : (entrySet = new EntrySet());
2824	>	EntrySetView<K,V> es = entrySet;
2825	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2826		}
2827
2828		/**
2829		* Returns an enumeration of the keys in this table.
2830		*
2831		* @return an enumeration of the keys in this table
2832	<	* @see #keySet
2832	>	* @see #keySet()
2833		*/
2834		public Enumeration<K> keys() {
2835	<	return new KeyIterator();
2835	>	return new KeyIterator<K,V>(this);
2836		}
2837
2838		/**
2839		* Returns an enumeration of the values in this table.
2840		*
2841		* @return an enumeration of the values in this table
2842	<	* @see #values
2842	>	* @see #values()
2843		*/
2844		public Enumeration<V> elements() {
2845	<	return new ValueIterator();
2845	>	return new ValueIterator<K,V>(this);
2846		}
2847
2848	<	/* ---------------- Iterator Support -------------- */
2848	>	/**
2849	>	* Returns the hash code value for this {@link Map}, i.e.,
2850	>	* the sum of, for each key-value pair in the map,
2851	>	* {@code key.hashCode() ^ value.hashCode()}.
2852	>	*
2853	>	* @return the hash code value for this map
2854	>	*/
2855	>	public int hashCode() {
2856	>	int h = 0;
2857	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2858	>	V v;
2859	>	while ((v = it.advance()) != null) {
2860	>	h += it.nextKey.hashCode() ^ v.hashCode();
2861	>	}
2862	>	return h;
2863	>	}
2864
2865	<	abstract class HashIterator {
2866	<	int nextSegmentIndex;
2867	<	int nextTableIndex;
2868	<	HashEntry<K,V>[] currentTable;
2869	<	HashEntry<K, V> nextEntry;
2870	<	HashEntry<K, V> lastReturned;
2865	>	/**
2866	>	* Returns a string representation of this map.  The string
2867	>	* representation consists of a list of key-value mappings (in no
2868	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
2869	>	* mappings are separated by the characters {@code ", "} (comma
2870	>	* and space).  Each key-value mapping is rendered as the key
2871	>	* followed by an equals sign ("{@code =}") followed by the
2872	>	* associated value.
2873	>	*
2874	>	* @return a string representation of this map
2875	>	*/
2876	>	public String toString() {
2877	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2878	>	StringBuilder sb = new StringBuilder();
2879	>	sb.append('{');
2880	>	V v;
2881	>	if ((v = it.advance()) != null) {
2882	>	for (;;) {
2883	>	K k = it.nextKey;
2884	>	sb.append(k == this ? "(this Map)" : k);
2885	>	sb.append('=');
2886	>	sb.append(v == this ? "(this Map)" : v);
2887	>	if ((v = it.advance()) == null)
2888	>	break;
2889	>	sb.append(',').append(' ');
2890	>	}
2891	>	}
2892	>	return sb.append('}').toString();
2893	>	}
2894
2895	<	HashIterator() {
2896	<	nextSegmentIndex = segments.length - 1;
2897	<	nextTableIndex = -1;
2898	<	advance();
2895	>	/**
2896	>	* Compares the specified object with this map for equality.
2897	>	* Returns {@code true} if the given object is a map with the same
2898	>	* mappings as this map.  This operation may return misleading
2899	>	* results if either map is concurrently modified during execution
2900	>	* of this method.
2901	>	*
2902	>	* @param o object to be compared for equality with this map
2903	>	* @return {@code true} if the specified object is equal to this map
2904	>	*/
2905	>	public boolean equals(Object o) {
2906	>	if (o != this) {
2907	>	if (!(o instanceof Map))
2908	>	return false;
2909	>	Map<?,?> m = (Map<?,?>) o;
2910	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2911	>	V val;
2912	>	while ((val = it.advance()) != null) {
2913	>	Object v = m.get(it.nextKey);
2914	>	if (v == null || (v != val && !v.equals(val)))
2915	>	return false;
2916	>	}
2917	>	for (Map.Entry<?,?> e : m.entrySet()) {
2918	>	Object mk, mv, v;
2919	>	if ((mk = e.getKey()) == null ||
2920	>	(mv = e.getValue()) == null ||
2921	>	(v = internalGet(mk)) == null ||
2922	>	(mv != v && !mv.equals(v)))
2923	>	return false;
2924	>	}
2925		}
2926	+	return true;
2927	+	}
2928
2929	<	public boolean hasMoreElements() { return hasNext(); }
2929	>	/* ----------------Iterators -------------- */
2930
2931	<	final void advance() {
2932	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
2933	<	return;
2931	>	@SuppressWarnings("serial") static final class KeyIterator<K,V>
2932	>	extends Traverser<K,V,Object>
2933	>	implements Spliterator<K>, Iterator<K>, Enumeration<K> {
2934	>	KeyIterator(ConcurrentHashMap<K, V> map) { super(map); }
2935	>	KeyIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
2936	>	super(map, it);
2937	>	}
2938	>	public KeyIterator<K,V> trySplit() {
2939	>	if (tab != null && baseIndex == baseLimit)
2940	>	return null;
2941	>	return new KeyIterator<K,V>(map, this);
2942	>	}
2943	>	public final K next() {
2944	>	if (nextVal == null && advance() == null)
2945	>	throw new NoSuchElementException();
2946	>	K k = nextKey;
2947	>	nextVal = null;
2948	>	return k;
2949	>	}
2950
2951	<	while (nextTableIndex >= 0) {
1076	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
1077	<	return;
1078	<	}
2951	>	public final K nextElement() { return next(); }
2952
2953	<	while (nextSegmentIndex >= 0) {
2954	<	Segment<K,V> seg = segments[nextSegmentIndex--];
2955	<	if (seg.count != 0) {
2956	<	currentTable = seg.table;
2957	<	for (int j = currentTable.length - 1; j >= 0; --j) {
2958	<	if ( (nextEntry = currentTable[j]) != null) {
1086	<	nextTableIndex = j - 1;
1087	<	return;
1088	<	}
1089	<	}
1090	<	}
1091	<	}
2953	>	public Iterator<K> iterator() { return this; }
2954	>
2955	>	public void forEach(Consumer<? super K> action) {
2956	>	if (action == null) throw new NullPointerException();
2957	>	while (advance() != null)
2958	>	action.accept(nextKey);
2959		}
2960
2961	<	public boolean hasNext() { return nextEntry != null; }
2961	>	public boolean tryAdvance(Consumer<? super K> block) {
2962	>	if (block == null) throw new NullPointerException();
2963	>	if (advance() == null)
2964	>	return false;
2965	>	block.accept(nextKey);
2966	>	return true;
2967	>	}
2968	>	}
2969
2970	<	HashEntry<K,V> nextEntry() {
2971	<	if (nextEntry == null)
2970	>	@SuppressWarnings("serial") static final class ValueIterator<K,V>
2971	>	extends Traverser<K,V,Object>
2972	>	implements Spliterator<V>, Iterator<V>, Enumeration<V> {
2973	>	ValueIterator(ConcurrentHashMap<K, V> map) { super(map); }
2974	>	ValueIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
2975	>	super(map, it);
2976	>	}
2977	>	public ValueIterator<K,V> trySplit() {
2978	>	if (tab != null && baseIndex == baseLimit)
2979	>	return null;
2980	>	return new ValueIterator<K,V>(map, this);
2981	>	}
2982	>
2983	>	public final V next() {
2984	>	V v;
2985	>	if ((v = nextVal) == null && (v = advance()) == null)
2986		throw new NoSuchElementException();
2987	<	lastReturned = nextEntry;
2988	<	advance();
1101	<	return lastReturned;
2987	>	nextVal = null;
2988	>	return v;
2989		}
2990
2991	<	public void remove() {
2992	<	if (lastReturned == null)
2993	<	throw new IllegalStateException();
2994	<	ConcurrentHashMap.this.remove(lastReturned.key);
2995	<	lastReturned = null;
2991	>	public final V nextElement() { return next(); }
2992	>
2993	>	public Iterator<V> iterator() { return this; }
2994	>
2995	>	public void forEach(Consumer<? super V> action) {
2996	>	if (action == null) throw new NullPointerException();
2997	>	V v;
2998	>	while ((v = advance()) != null)
2999	>	action.accept(v);
3000	>	}
3001	>
3002	>	public boolean tryAdvance(Consumer<? super V> block) {
3003	>	V v;
3004	>	if (block == null) throw new NullPointerException();
3005	>	if ((v = advance()) == null)
3006	>	return false;
3007	>	block.accept(v);
3008	>	return true;
3009		}
1110	–	}
3010
1112	–	final class KeyIterator
1113	–	extends HashIterator
1114	–	implements Iterator<K>, Enumeration<K>
1115	–	{
1116	–	public K next()        { return super.nextEntry().key; }
1117	–	public K nextElement() { return super.nextEntry().key; }
3011		}
3012
3013	<	final class ValueIterator
3014	<	extends HashIterator
3015	<	implements Iterator<V>, Enumeration<V>
3016	<	{
3017	<	public V next()        { return super.nextEntry().value; }
3018	<	public V nextElement() { return super.nextEntry().value; }
3013	>	@SuppressWarnings("serial") static final class EntryIterator<K,V>
3014	>	extends Traverser<K,V,Object>
3015	>	implements Spliterator<Map.Entry<K,V>>, Iterator<Map.Entry<K,V>> {
3016	>	EntryIterator(ConcurrentHashMap<K, V> map) { super(map); }
3017	>	EntryIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
3018	>	super(map, it);
3019	>	}
3020	>	public EntryIterator<K,V> trySplit() {
3021	>	if (tab != null && baseIndex == baseLimit)
3022	>	return null;
3023	>	return new EntryIterator<K,V>(map, this);
3024	>	}
3025	>
3026	>	public final Map.Entry<K,V> next() {
3027	>	V v;
3028	>	if ((v = nextVal) == null && (v = advance()) == null)
3029	>	throw new NoSuchElementException();
3030	>	K k = nextKey;
3031	>	nextVal = null;
3032	>	return new MapEntry<K,V>(k, v, map);
3033	>	}
3034	>
3035	>	public Iterator<Map.Entry<K,V>> iterator() { return this; }
3036	>
3037	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
3038	>	if (action == null) throw new NullPointerException();
3039	>	V v;
3040	>	while ((v = advance()) != null)
3041	>	action.accept(entryFor(nextKey, v));
3042	>	}
3043	>
3044	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> block) {
3045	>	V v;
3046	>	if (block == null) throw new NullPointerException();
3047	>	if ((v = advance()) == null)
3048	>	return false;
3049	>	block.accept(entryFor(nextKey, v));
3050	>	return true;
3051	>	}
3052	>
3053		}
3054
3055		/**
3056	<	* Custom Entry class used by EntryIterator.next(), that relays
1130	<	* setValue changes to the underlying map.
3056	>	* Exported Entry for iterators
3057		*/
3058	<	final class WriteThroughEntry
3059	<	extends AbstractMap.SimpleEntry<K,V>
3060	<	{
3061	<	WriteThroughEntry(K k, V v) {
3062	<	super(k,v);
3058	>	static final class MapEntry<K,V> implements Map.Entry<K, V> {
3059	>	final K key; // non-null
3060	>	V val;       // non-null
3061	>	final ConcurrentHashMap<K, V> map;
3062	>	MapEntry(K key, V val, ConcurrentHashMap<K, V> map) {
3063	>	this.key = key;
3064	>	this.val = val;
3065	>	this.map = map;
3066	>	}
3067	>	public final K getKey()       { return key; }
3068	>	public final V getValue()     { return val; }
3069	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3070	>	public final String toString(){ return key + "=" + val; }
3071	>
3072	>	public final boolean equals(Object o) {
3073	>	Object k, v; Map.Entry<?,?> e;
3074	>	return ((o instanceof Map.Entry) &&
3075	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3076	>	(v = e.getValue()) != null &&
3077	>	(k == key || k.equals(key)) &&
3078	>	(v == val || v.equals(val)));
3079		}
3080
3081		/**
3082	<	* Set our entry's value and write through to the map. The
3083	<	* value to return is somewhat arbitrary here. Since a
3084	<	* WriteThroughEntry does not necessarily track asynchronous
3085	<	* changes, the most recent "previous" value could be
3086	<	* different from what we return (or could even have been
3087	<	* removed in which case the put will re-establish). We do not
1146	<	* and cannot guarantee more.
3082	>	* Sets our entry's value and writes through to the map. The
3083	>	* value to return is somewhat arbitrary here. Since we do not
3084	>	* necessarily track asynchronous changes, the most recent
3085	>	* "previous" value could be different from what we return (or
3086	>	* could even have been removed in which case the put will
3087	>	* re-establish). We do not and cannot guarantee more.
3088		*/
3089	<	public V setValue(V value) {
3089	>	public final V setValue(V value) {
3090		if (value == null) throw new NullPointerException();
3091	<	V v = super.setValue(value);
3092	<	ConcurrentHashMap.this.put(getKey(), value);
3091	>	V v = val;
3092	>	val = value;
3093	>	map.put(key, value);
3094		return v;
3095		}
3096		}
3097
3098	<	final class EntryIterator
3099	<	extends HashIterator
3100	<	implements Iterator<Entry<K,V>>
3101	<	{
3102	<	public Map.Entry<K,V> next() {
3103	<	HashEntry<K,V> e = super.nextEntry();
3104	<	return new WriteThroughEntry(e.key, e.value);
3098	>	/**
3099	>	* Returns exportable snapshot entry for the given key and value
3100	>	* when write-through can't or shouldn't be used.
3101	>	*/
3102	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3103	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
3104	>	}
3105	>
3106	>	/* ---------------- Serialization Support -------------- */
3107	>
3108	>	/**
3109	>	* Stripped-down version of helper class used in previous version,
3110	>	* declared for the sake of serialization compatibility
3111	>	*/
3112	>	static class Segment<K,V> implements Serializable {
3113	>	private static final long serialVersionUID = 2249069246763182397L;
3114	>	final float loadFactor;
3115	>	Segment(float lf) { this.loadFactor = lf; }
3116	>	}
3117	>
3118	>	/**
3119	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3120	>	* stream (i.e., serializes it).
3121	>	* @param s the stream
3122	>	* @serialData
3123	>	* the key (Object) and value (Object)
3124	>	* for each key-value mapping, followed by a null pair.
3125	>	* The key-value mappings are emitted in no particular order.
3126	>	*/
3127	>	@SuppressWarnings("unchecked") private void writeObject
3128	>	(java.io.ObjectOutputStream s)
3129	>	throws java.io.IOException {
3130	>	if (segments == null) { // for serialization compatibility
3131	>	segments = (Segment<K,V>[])
3132	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3133	>	for (int i = 0; i < segments.length; ++i)
3134	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3135	>	}
3136	>	s.defaultWriteObject();
3137	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3138	>	V v;
3139	>	while ((v = it.advance()) != null) {
3140	>	s.writeObject(it.nextKey);
3141	>	s.writeObject(v);
3142		}
3143	+	s.writeObject(null);
3144	+	s.writeObject(null);
3145	+	segments = null; // throw away
3146		}
3147
3148	<	final class KeySet extends AbstractSet<K> {
3149	<	public Iterator<K> iterator() {
3150	<	return new KeyIterator();
3148	>	/**
3149	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3150	>	* @param s the stream
3151	>	*/
3152	>	@SuppressWarnings("unchecked") private void readObject
3153	>	(java.io.ObjectInputStream s)
3154	>	throws java.io.IOException, ClassNotFoundException {
3155	>	s.defaultReadObject();
3156	>	this.segments = null; // unneeded
3157	>
3158	>	// Create all nodes, then place in table once size is known
3159	>	long size = 0L;
3160	>	Node<V> p = null;
3161	>	for (;;) {
3162	>	K k = (K) s.readObject();
3163	>	V v = (V) s.readObject();
3164	>	if (k != null && v != null) {
3165	>	int h = spread(k.hashCode());
3166	>	p = new Node<V>(h, k, v, p);
3167	>	++size;
3168	>	}
3169	>	else
3170	>	break;
3171		}
3172	<	public int size() {
3173	<	return ConcurrentHashMap.this.size();
3172	>	if (p != null) {
3173	>	boolean init = false;
3174	>	int n;
3175	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3176	>	n = MAXIMUM_CAPACITY;
3177	>	else {
3178	>	int sz = (int)size;
3179	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3180	>	}
3181	>	int sc = sizeCtl;
3182	>	boolean collide = false;
3183	>	if (n > sc &&
3184	>	U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
3185	>	try {
3186	>	if (table == null) {
3187	>	init = true;
3188	>	@SuppressWarnings("rawtypes") Node[] rt = new Node[n];
3189	>	Node<V>[] tab = (Node<V>[])rt;
3190	>	int mask = n - 1;
3191	>	while (p != null) {
3192	>	int j = p.hash & mask;
3193	>	Node<V> next = p.next;
3194	>	Node<V> q = p.next = tabAt(tab, j);
3195	>	setTabAt(tab, j, p);
3196	>	if (!collide && q != null && q.hash == p.hash)
3197	>	collide = true;
3198	>	p = next;
3199	>	}
3200	>	table = tab;
3201	>	addCount(size, -1);
3202	>	sc = n - (n >>> 2);
3203	>	}
3204	>	} finally {
3205	>	sizeCtl = sc;
3206	>	}
3207	>	if (collide) { // rescan and convert to TreeBins
3208	>	Node<V>[] tab = table;
3209	>	for (int i = 0; i < tab.length; ++i) {
3210	>	int c = 0;
3211	>	for (Node<V> e = tabAt(tab, i); e != null; e = e.next) {
3212	>	if (++c > TREE_THRESHOLD &&
3213	>	(e.key instanceof Comparable)) {
3214	>	replaceWithTreeBin(tab, i, e.key);
3215	>	break;
3216	>	}
3217	>	}
3218	>	}
3219	>	}
3220	>	}
3221	>	if (!init) { // Can only happen if unsafely published.
3222	>	while (p != null) {
3223	>	internalPut((K)p.key, p.val, false);
3224	>	p = p.next;
3225	>	}
3226	>	}
3227		}
3228	<	public boolean contains(Object o) {
3229	<	return ConcurrentHashMap.this.containsKey(o);
3228	>	}
3229	>
3230	>	// -------------------------------------------------------
3231	>
3232	>	// Sequential bulk operations
3233	>
3234	>	/**
3235	>	* Performs the given action for each (key, value).
3236	>	*
3237	>	* @param action the action
3238	>	*/
3239	>	public void forEachSequentially
3240	>	(BiConsumer<? super K, ? super V> action) {
3241	>	if (action == null) throw new NullPointerException();
3242	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3243	>	V v;
3244	>	while ((v = it.advance()) != null)
3245	>	action.accept(it.nextKey, v);
3246	>	}
3247	>
3248	>	/**
3249	>	* Performs the given action for each non-null transformation
3250	>	* of each (key, value).
3251	>	*
3252	>	* @param transformer a function returning the transformation
3253	>	* for an element, or null if there is no transformation (in
3254	>	* which case the action is not applied)
3255	>	* @param action the action
3256	>	*/
3257	>	public <U> void forEachSequentially
3258	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3259	>	Consumer<? super U> action) {
3260	>	if (transformer == null || action == null)
3261	>	throw new NullPointerException();
3262	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3263	>	V v; U u;
3264	>	while ((v = it.advance()) != null) {
3265	>	if ((u = transformer.apply(it.nextKey, v)) != null)
3266	>	action.accept(u);
3267		}
3268	<	public boolean remove(Object o) {
3269	<	return ConcurrentHashMap.this.remove(o) != null;
3268	>	}
3269	>
3270	>	/**
3271	>	* Returns a non-null result from applying the given search
3272	>	* function on each (key, value), or null if none.
3273	>	*
3274	>	* @param searchFunction a function returning a non-null
3275	>	* result on success, else null
3276	>	* @return a non-null result from applying the given search
3277	>	* function on each (key, value), or null if none
3278	>	*/
3279	>	public <U> U searchSequentially
3280	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3281	>	if (searchFunction == null) throw new NullPointerException();
3282	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3283	>	V v; U u;
3284	>	while ((v = it.advance()) != null) {
3285	>	if ((u = searchFunction.apply(it.nextKey, v)) != null)
3286	>	return u;
3287		}
3288	<	public void clear() {
3289	<	ConcurrentHashMap.this.clear();
3288	>	return null;
3289	>	}
3290	>
3291	>	/**
3292	>	* Returns the result of accumulating the given transformation
3293	>	* of all (key, value) pairs using the given reducer to
3294	>	* combine values, or null if none.
3295	>	*
3296	>	* @param transformer a function returning the transformation
3297	>	* for an element, or null if there is no transformation (in
3298	>	* which case it is not combined)
3299	>	* @param reducer a commutative associative combining function
3300	>	* @return the result of accumulating the given transformation
3301	>	* of all (key, value) pairs
3302	>	*/
3303	>	public <U> U reduceSequentially
3304	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3305	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3306	>	if (transformer == null || reducer == null)
3307	>	throw new NullPointerException();
3308	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3309	>	U r = null, u; V v;
3310	>	while ((v = it.advance()) != null) {
3311	>	if ((u = transformer.apply(it.nextKey, v)) != null)
3312	>	r = (r == null) ? u : reducer.apply(r, u);
3313		}
3314	+	return r;
3315	+	}
3316	+
3317	+	/**
3318	+	* Returns the result of accumulating the given transformation
3319	+	* of all (key, value) pairs using the given reducer to
3320	+	* combine values, and the given basis as an identity value.
3321	+	*
3322	+	* @param transformer a function returning the transformation
3323	+	* for an element
3324	+	* @param basis the identity (initial default value) for the reduction
3325	+	* @param reducer a commutative associative combining function
3326	+	* @return the result of accumulating the given transformation
3327	+	* of all (key, value) pairs
3328	+	*/
3329	+	public double reduceToDoubleSequentially
3330	+	(ToDoubleBiFunction<? super K, ? super V> transformer,
3331	+	double basis,
3332	+	DoubleBinaryOperator reducer) {
3333	+	if (transformer == null || reducer == null)
3334	+	throw new NullPointerException();
3335	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3336	+	double r = basis; V v;
3337	+	while ((v = it.advance()) != null)
3338	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(it.nextKey, v));
3339	+	return r;
3340	+	}
3341	+
3342	+	/**
3343	+	* Returns the result of accumulating the given transformation
3344	+	* of all (key, value) pairs using the given reducer to
3345	+	* combine values, and the given basis as an identity value.
3346	+	*
3347	+	* @param transformer a function returning the transformation
3348	+	* for an element
3349	+	* @param basis the identity (initial default value) for the reduction
3350	+	* @param reducer a commutative associative combining function
3351	+	* @return the result of accumulating the given transformation
3352	+	* of all (key, value) pairs
3353	+	*/
3354	+	public long reduceToLongSequentially
3355	+	(ToLongBiFunction<? super K, ? super V> transformer,
3356	+	long basis,
3357	+	LongBinaryOperator reducer) {
3358	+	if (transformer == null || reducer == null)
3359	+	throw new NullPointerException();
3360	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3361	+	long r = basis; V v;
3362	+	while ((v = it.advance()) != null)
3363	+	r = reducer.applyAsLong(r, transformer.applyAsLong(it.nextKey, v));
3364	+	return r;
3365		}
3366
3367	<	final class Values extends AbstractCollection<V> {
3368	<	public Iterator<V> iterator() {
3369	<	return new ValueIterator();
3367	>	/**
3368	>	* Returns the result of accumulating the given transformation
3369	>	* of all (key, value) pairs using the given reducer to
3370	>	* combine values, and the given basis as an identity value.
3371	>	*
3372	>	* @param transformer a function returning the transformation
3373	>	* for an element
3374	>	* @param basis the identity (initial default value) for the reduction
3375	>	* @param reducer a commutative associative combining function
3376	>	* @return the result of accumulating the given transformation
3377	>	* of all (key, value) pairs
3378	>	*/
3379	>	public int reduceToIntSequentially
3380	>	(ToIntBiFunction<? super K, ? super V> transformer,
3381	>	int basis,
3382	>	IntBinaryOperator reducer) {
3383	>	if (transformer == null || reducer == null)
3384	>	throw new NullPointerException();
3385	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3386	>	int r = basis; V v;
3387	>	while ((v = it.advance()) != null)
3388	>	r = reducer.applyAsInt(r, transformer.applyAsInt(it.nextKey, v));
3389	>	return r;
3390	>	}
3391	>
3392	>	/**
3393	>	* Performs the given action for each key.
3394	>	*
3395	>	* @param action the action
3396	>	*/
3397	>	public void forEachKeySequentially
3398	>	(Consumer<? super K> action) {
3399	>	if (action == null) throw new NullPointerException();
3400	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3401	>	while (it.advance() != null)
3402	>	action.accept(it.nextKey);
3403	>	}
3404	>
3405	>	/**
3406	>	* Performs the given action for each non-null transformation
3407	>	* of each key.
3408	>	*
3409	>	* @param transformer a function returning the transformation
3410	>	* for an element, or null if there is no transformation (in
3411	>	* which case the action is not applied)
3412	>	* @param action the action
3413	>	*/
3414	>	public <U> void forEachKeySequentially
3415	>	(Function<? super K, ? extends U> transformer,
3416	>	Consumer<? super U> action) {
3417	>	if (transformer == null || action == null)
3418	>	throw new NullPointerException();
3419	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3420	>	U u;
3421	>	while (it.advance() != null) {
3422	>	if ((u = transformer.apply(it.nextKey)) != null)
3423	>	action.accept(u);
3424		}
3425	<	public int size() {
3426	<	return ConcurrentHashMap.this.size();
3425	>	ForkJoinTasks.forEachKey
3426	>	(this, transformer, action).invoke();
3427	>	}
3428	>
3429	>	/**
3430	>	* Returns a non-null result from applying the given search
3431	>	* function on each key, or null if none.
3432	>	*
3433	>	* @param searchFunction a function returning a non-null
3434	>	* result on success, else null
3435	>	* @return a non-null result from applying the given search
3436	>	* function on each key, or null if none
3437	>	*/
3438	>	public <U> U searchKeysSequentially
3439	>	(Function<? super K, ? extends U> searchFunction) {
3440	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3441	>	U u;
3442	>	while (it.advance() != null) {
3443	>	if ((u = searchFunction.apply(it.nextKey)) != null)
3444	>	return u;
3445		}
3446	<	public boolean contains(Object o) {
3447	<	return ConcurrentHashMap.this.containsValue(o);
3446	>	return null;
3447	>	}
3448	>
3449	>	/**
3450	>	* Returns the result of accumulating all keys using the given
3451	>	* reducer to combine values, or null if none.
3452	>	*
3453	>	* @param reducer a commutative associative combining function
3454	>	* @return the result of accumulating all keys using the given
3455	>	* reducer to combine values, or null if none
3456	>	*/
3457	>	public K reduceKeysSequentially
3458	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
3459	>	if (reducer == null) throw new NullPointerException();
3460	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3461	>	K r = null;
3462	>	while (it.advance() != null) {
3463	>	K u = it.nextKey;
3464	>	r = (r == null) ? u : reducer.apply(r, u);
3465		}
3466	<	public void clear() {
3467	<	ConcurrentHashMap.this.clear();
3466	>	return r;
3467	>	}
3468	>
3469	>	/**
3470	>	* Returns the result of accumulating the given transformation
3471	>	* of all keys using the given reducer to combine values, or
3472	>	* null if none.
3473	>	*
3474	>	* @param transformer a function returning the transformation
3475	>	* for an element, or null if there is no transformation (in
3476	>	* which case it is not combined)
3477	>	* @param reducer a commutative associative combining function
3478	>	* @return the result of accumulating the given transformation
3479	>	* of all keys
3480	>	*/
3481	>	public <U> U reduceKeysSequentially
3482	>	(Function<? super K, ? extends U> transformer,
3483	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3484	>	if (transformer == null || reducer == null)
3485	>	throw new NullPointerException();
3486	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3487	>	U r = null, u;
3488	>	while (it.advance() != null) {
3489	>	if ((u = transformer.apply(it.nextKey)) != null)
3490	>	r = (r == null) ? u : reducer.apply(r, u);
3491		}
3492	+	return r;
3493		}
3494
3495	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
3496	<	public Iterator<Map.Entry<K,V>> iterator() {
3497	<	return new EntryIterator();
3495	>	/**
3496	>	* Returns the result of accumulating the given transformation
3497	>	* of all keys using the given reducer to combine values, and
3498	>	* the given basis as an identity value.
3499	>	*
3500	>	* @param transformer a function returning the transformation
3501	>	* for an element
3502	>	* @param basis the identity (initial default value) for the reduction
3503	>	* @param reducer a commutative associative combining function
3504	>	* @return the result of accumulating the given transformation
3505	>	* of all keys
3506	>	*/
3507	>	public double reduceKeysToDoubleSequentially
3508	>	(ToDoubleFunction<? super K> transformer,
3509	>	double basis,
3510	>	DoubleBinaryOperator reducer) {
3511	>	if (transformer == null || reducer == null)
3512	>	throw new NullPointerException();
3513	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3514	>	double r = basis;
3515	>	while (it.advance() != null)
3516	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(it.nextKey));
3517	>	return r;
3518	>	}
3519	>
3520	>	/**
3521	>	* Returns the result of accumulating the given transformation
3522	>	* of all keys using the given reducer to combine values, and
3523	>	* the given basis as an identity value.
3524	>	*
3525	>	* @param transformer a function returning the transformation
3526	>	* for an element
3527	>	* @param basis the identity (initial default value) for the reduction
3528	>	* @param reducer a commutative associative combining function
3529	>	* @return the result of accumulating the given transformation
3530	>	* of all keys
3531	>	*/
3532	>	public long reduceKeysToLongSequentially
3533	>	(ToLongFunction<? super K> transformer,
3534	>	long basis,
3535	>	LongBinaryOperator reducer) {
3536	>	if (transformer == null || reducer == null)
3537	>	throw new NullPointerException();
3538	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3539	>	long r = basis;
3540	>	while (it.advance() != null)
3541	>	r = reducer.applyAsLong(r, transformer.applyAsLong(it.nextKey));
3542	>	return r;
3543	>	}
3544	>
3545	>	/**
3546	>	* Returns the result of accumulating the given transformation
3547	>	* of all keys using the given reducer to combine values, and
3548	>	* the given basis as an identity value.
3549	>	*
3550	>	* @param transformer a function returning the transformation
3551	>	* for an element
3552	>	* @param basis the identity (initial default value) for the reduction
3553	>	* @param reducer a commutative associative combining function
3554	>	* @return the result of accumulating the given transformation
3555	>	* of all keys
3556	>	*/
3557	>	public int reduceKeysToIntSequentially
3558	>	(ToIntFunction<? super K> transformer,
3559	>	int basis,
3560	>	IntBinaryOperator reducer) {
3561	>	if (transformer == null || reducer == null)
3562	>	throw new NullPointerException();
3563	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3564	>	int r = basis;
3565	>	while (it.advance() != null)
3566	>	r = reducer.applyAsInt(r, transformer.applyAsInt(it.nextKey));
3567	>	return r;
3568	>	}
3569	>
3570	>	/**
3571	>	* Performs the given action for each value.
3572	>	*
3573	>	* @param action the action
3574	>	*/
3575	>	public void forEachValueSequentially(Consumer<? super V> action) {
3576	>	if (action == null) throw new NullPointerException();
3577	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3578	>	V v;
3579	>	while ((v = it.advance()) != null)
3580	>	action.accept(v);
3581	>	}
3582	>
3583	>	/**
3584	>	* Performs the given action for each non-null transformation
3585	>	* of each value.
3586	>	*
3587	>	* @param transformer a function returning the transformation
3588	>	* for an element, or null if there is no transformation (in
3589	>	* which case the action is not applied)
3590	>	*/
3591	>	public <U> void forEachValueSequentially
3592	>	(Function<? super V, ? extends U> transformer,
3593	>	Consumer<? super U> action) {
3594	>	if (transformer == null || action == null)
3595	>	throw new NullPointerException();
3596	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3597	>	V v; U u;
3598	>	while ((v = it.advance()) != null) {
3599	>	if ((u = transformer.apply(v)) != null)
3600	>	action.accept(u);
3601		}
3602	<	public boolean contains(Object o) {
3603	<	if (!(o instanceof Map.Entry))
3604	<	return false;
3605	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3606	<	V v = ConcurrentHashMap.this.get(e.getKey());
3607	<	return v != null && v.equals(e.getValue());
3602	>	}
3603	>
3604	>	/**
3605	>	* Returns a non-null result from applying the given search
3606	>	* function on each value, or null if none.
3607	>	*
3608	>	* @param searchFunction a function returning a non-null
3609	>	* result on success, else null
3610	>	* @return a non-null result from applying the given search
3611	>	* function on each value, or null if none
3612	>	*/
3613	>	public <U> U searchValuesSequentially
3614	>	(Function<? super V, ? extends U> searchFunction) {
3615	>	if (searchFunction == null) throw new NullPointerException();
3616	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3617	>	V v; U u;
3618	>	while ((v = it.advance()) != null) {
3619	>	if ((u = searchFunction.apply(v)) != null)
3620	>	return u;
3621		}
3622	<	public boolean remove(Object o) {
3623	<	if (!(o instanceof Map.Entry))
3624	<	return false;
3625	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3626	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
3622	>	return null;
3623	>	}
3624	>
3625	>	/**
3626	>	* Returns the result of accumulating all values using the
3627	>	* given reducer to combine values, or null if none.
3628	>	*
3629	>	* @param reducer a commutative associative combining function
3630	>	* @return the result of accumulating all values
3631	>	*/
3632	>	public V reduceValuesSequentially
3633	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
3634	>	if (reducer == null) throw new NullPointerException();
3635	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3636	>	V r = null; V v;
3637	>	while ((v = it.advance()) != null)
3638	>	r = (r == null) ? v : reducer.apply(r, v);
3639	>	return r;
3640	>	}
3641	>
3642	>	/**
3643	>	* Returns the result of accumulating the given transformation
3644	>	* of all values using the given reducer to combine values, or
3645	>	* null if none.
3646	>	*
3647	>	* @param transformer a function returning the transformation
3648	>	* for an element, or null if there is no transformation (in
3649	>	* which case it is not combined)
3650	>	* @param reducer a commutative associative combining function
3651	>	* @return the result of accumulating the given transformation
3652	>	* of all values
3653	>	*/
3654	>	public <U> U reduceValuesSequentially
3655	>	(Function<? super V, ? extends U> transformer,
3656	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3657	>	if (transformer == null || reducer == null)
3658	>	throw new NullPointerException();
3659	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3660	>	U r = null, u; V v;
3661	>	while ((v = it.advance()) != null) {
3662	>	if ((u = transformer.apply(v)) != null)
3663	>	r = (r == null) ? u : reducer.apply(r, u);
3664		}
3665	<	public int size() {
3666	<	return ConcurrentHashMap.this.size();
3665	>	return r;
3666	>	}
3667	>
3668	>	/**
3669	>	* Returns the result of accumulating the given transformation
3670	>	* of all values using the given reducer to combine values,
3671	>	* and the given basis as an identity value.
3672	>	*
3673	>	* @param transformer a function returning the transformation
3674	>	* for an element
3675	>	* @param basis the identity (initial default value) for the reduction
3676	>	* @param reducer a commutative associative combining function
3677	>	* @return the result of accumulating the given transformation
3678	>	* of all values
3679	>	*/
3680	>	public double reduceValuesToDoubleSequentially
3681	>	(ToDoubleFunction<? super V> transformer,
3682	>	double basis,
3683	>	DoubleBinaryOperator reducer) {
3684	>	if (transformer == null || reducer == null)
3685	>	throw new NullPointerException();
3686	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3687	>	double r = basis; V v;
3688	>	while ((v = it.advance()) != null)
3689	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
3690	>	return r;
3691	>	}
3692	>
3693	>	/**
3694	>	* Returns the result of accumulating the given transformation
3695	>	* of all values using the given reducer to combine values,
3696	>	* and the given basis as an identity value.
3697	>	*
3698	>	* @param transformer a function returning the transformation
3699	>	* for an element
3700	>	* @param basis the identity (initial default value) for the reduction
3701	>	* @param reducer a commutative associative combining function
3702	>	* @return the result of accumulating the given transformation
3703	>	* of all values
3704	>	*/
3705	>	public long reduceValuesToLongSequentially
3706	>	(ToLongFunction<? super V> transformer,
3707	>	long basis,
3708	>	LongBinaryOperator reducer) {
3709	>	if (transformer == null || reducer == null)
3710	>	throw new NullPointerException();
3711	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3712	>	long r = basis; V v;
3713	>	while ((v = it.advance()) != null)
3714	>	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
3715	>	return r;
3716	>	}
3717	>
3718	>	/**
3719	>	* Returns the result of accumulating the given transformation
3720	>	* of all values using the given reducer to combine values,
3721	>	* and the given basis as an identity value.
3722	>	*
3723	>	* @param transformer a function returning the transformation
3724	>	* for an element
3725	>	* @param basis the identity (initial default value) for the reduction
3726	>	* @param reducer a commutative associative combining function
3727	>	* @return the result of accumulating the given transformation
3728	>	* of all values
3729	>	*/
3730	>	public int reduceValuesToIntSequentially
3731	>	(ToIntFunction<? super V> transformer,
3732	>	int basis,
3733	>	IntBinaryOperator reducer) {
3734	>	if (transformer == null || reducer == null)
3735	>	throw new NullPointerException();
3736	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3737	>	int r = basis; V v;
3738	>	while ((v = it.advance()) != null)
3739	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
3740	>	return r;
3741	>	}
3742	>
3743	>	/**
3744	>	* Performs the given action for each entry.
3745	>	*
3746	>	* @param action the action
3747	>	*/
3748	>	public void forEachEntrySequentially
3749	>	(Consumer<? super Map.Entry<K,V>> action) {
3750	>	if (action == null) throw new NullPointerException();
3751	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3752	>	V v;
3753	>	while ((v = it.advance()) != null)
3754	>	action.accept(entryFor(it.nextKey, v));
3755	>	}
3756	>
3757	>	/**
3758	>	* Performs the given action for each non-null transformation
3759	>	* of each entry.
3760	>	*
3761	>	* @param transformer a function returning the transformation
3762	>	* for an element, or null if there is no transformation (in
3763	>	* which case the action is not applied)
3764	>	* @param action the action
3765	>	*/
3766	>	public <U> void forEachEntrySequentially
3767	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3768	>	Consumer<? super U> action) {
3769	>	if (transformer == null || action == null)
3770	>	throw new NullPointerException();
3771	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3772	>	V v; U u;
3773	>	while ((v = it.advance()) != null) {
3774	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
3775	>	action.accept(u);
3776		}
3777	<	public void clear() {
3778	<	ConcurrentHashMap.this.clear();
3777	>	}
3778	>
3779	>	/**
3780	>	* Returns a non-null result from applying the given search
3781	>	* function on each entry, or null if none.
3782	>	*
3783	>	* @param searchFunction a function returning a non-null
3784	>	* result on success, else null
3785	>	* @return a non-null result from applying the given search
3786	>	* function on each entry, or null if none
3787	>	*/
3788	>	public <U> U searchEntriesSequentially
3789	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
3790	>	if (searchFunction == null) throw new NullPointerException();
3791	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3792	>	V v; U u;
3793	>	while ((v = it.advance()) != null) {
3794	>	if ((u = searchFunction.apply(entryFor(it.nextKey, v))) != null)
3795	>	return u;
3796		}
3797	+	return null;
3798		}
3799
3800	<	/* ---------------- Serialization Support -------------- */
3800	>	/**
3801	>	* Returns the result of accumulating all entries using the
3802	>	* given reducer to combine values, or null if none.
3803	>	*
3804	>	* @param reducer a commutative associative combining function
3805	>	* @return the result of accumulating all entries
3806	>	*/
3807	>	public Map.Entry<K,V> reduceEntriesSequentially
3808	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3809	>	if (reducer == null) throw new NullPointerException();
3810	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3811	>	Map.Entry<K,V> r = null; V v;
3812	>	while ((v = it.advance()) != null) {
3813	>	Map.Entry<K,V> u = entryFor(it.nextKey, v);
3814	>	r = (r == null) ? u : reducer.apply(r, u);
3815	>	}
3816	>	return r;
3817	>	}
3818
3819		/**
3820	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
3821	<	* stream (i.e., serialize it).
3822	<	* @param s the stream
3823	<	* @serialData
3824	<	* the key (Object) and value (Object)
3825	<	* for each key-value mapping, followed by a null pair.
3826	<	* The key-value mappings are emitted in no particular order.
3820	>	* Returns the result of accumulating the given transformation
3821	>	* of all entries using the given reducer to combine values,
3822	>	* or null if none.
3823	>	*
3824	>	* @param transformer a function returning the transformation
3825	>	* for an element, or null if there is no transformation (in
3826	>	* which case it is not combined)
3827	>	* @param reducer a commutative associative combining function
3828	>	* @return the result of accumulating the given transformation
3829	>	* of all entries
3830	>	*/
3831	>	public <U> U reduceEntriesSequentially
3832	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3833	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3834	>	if (transformer == null || reducer == null)
3835	>	throw new NullPointerException();
3836	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3837	>	U r = null, u; V v;
3838	>	while ((v = it.advance()) != null) {
3839	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
3840	>	r = (r == null) ? u : reducer.apply(r, u);
3841	>	}
3842	>	return r;
3843	>	}
3844	>
3845	>	/**
3846	>	* Returns the result of accumulating the given transformation
3847	>	* of all entries using the given reducer to combine values,
3848	>	* and the given basis as an identity value.
3849	>	*
3850	>	* @param transformer a function returning the transformation
3851	>	* for an element
3852	>	* @param basis the identity (initial default value) for the reduction
3853	>	* @param reducer a commutative associative combining function
3854	>	* @return the result of accumulating the given transformation
3855	>	* of all entries
3856	>	*/
3857	>	public double reduceEntriesToDoubleSequentially
3858	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
3859	>	double basis,
3860	>	DoubleBinaryOperator reducer) {
3861	>	if (transformer == null || reducer == null)
3862	>	throw new NullPointerException();
3863	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3864	>	double r = basis; V v;
3865	>	while ((v = it.advance()) != null)
3866	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(it.nextKey, v)));
3867	>	return r;
3868	>	}
3869	>
3870	>	/**
3871	>	* Returns the result of accumulating the given transformation
3872	>	* of all entries using the given reducer to combine values,
3873	>	* and the given basis as an identity value.
3874	>	*
3875	>	* @param transformer a function returning the transformation
3876	>	* for an element
3877	>	* @param basis the identity (initial default value) for the reduction
3878	>	* @param reducer a commutative associative combining function
3879	>	* @return the result of accumulating the given transformation
3880	>	* of all entries
3881	>	*/
3882	>	public long reduceEntriesToLongSequentially
3883	>	(ToLongFunction<Map.Entry<K,V>> transformer,
3884	>	long basis,
3885	>	LongBinaryOperator reducer) {
3886	>	if (transformer == null || reducer == null)
3887	>	throw new NullPointerException();
3888	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3889	>	long r = basis; V v;
3890	>	while ((v = it.advance()) != null)
3891	>	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(it.nextKey, v)));
3892	>	return r;
3893	>	}
3894	>
3895	>	/**
3896	>	* Returns the result of accumulating the given transformation
3897	>	* of all entries using the given reducer to combine values,
3898	>	* and the given basis as an identity value.
3899	>	*
3900	>	* @param transformer a function returning the transformation
3901	>	* for an element
3902	>	* @param basis the identity (initial default value) for the reduction
3903	>	* @param reducer a commutative associative combining function
3904	>	* @return the result of accumulating the given transformation
3905	>	* of all entries
3906	>	*/
3907	>	public int reduceEntriesToIntSequentially
3908	>	(ToIntFunction<Map.Entry<K,V>> transformer,
3909	>	int basis,
3910	>	IntBinaryOperator reducer) {
3911	>	if (transformer == null || reducer == null)
3912	>	throw new NullPointerException();
3913	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3914	>	int r = basis; V v;
3915	>	while ((v = it.advance()) != null)
3916	>	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(it.nextKey, v)));
3917	>	return r;
3918	>	}
3919	>
3920	>	// Parallel bulk operations
3921	>
3922	>	/**
3923	>	* Performs the given action for each (key, value).
3924	>	*
3925	>	* @param action the action
3926		*/
3927	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
3928	<	s.defaultWriteObject();
3927	>	public void forEachInParallel(BiConsumer<? super K,? super V> action) {
3928	>	ForkJoinTasks.forEach
3929	>	(this, action).invoke();
3930	>	}
3931
3932	<	for (int k = 0; k < segments.length; ++k) {
3933	<	Segment<K,V> seg = segments[k];
3934	<	seg.lock();
3935	<	try {
3936	<	HashEntry<K,V>[] tab = seg.table;
3937	<	for (int i = 0; i < tab.length; ++i) {
3938	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
3939	<	s.writeObject(e.key);
3940	<	s.writeObject(e.value);
3932	>	/**
3933	>	* Performs the given action for each non-null transformation
3934	>	* of each (key, value).
3935	>	*
3936	>	* @param transformer a function returning the transformation
3937	>	* for an element, or null if there is no transformation (in
3938	>	* which case the action is not applied)
3939	>	* @param action the action
3940	>	*/
3941	>	public <U> void forEachInParallel
3942	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3943	>	Consumer<? super U> action) {
3944	>	ForkJoinTasks.forEach
3945	>	(this, transformer, action).invoke();
3946	>	}
3947	>
3948	>	/**
3949	>	* Returns a non-null result from applying the given search
3950	>	* function on each (key, value), or null if none.  Upon
3951	>	* success, further element processing is suppressed and the
3952	>	* results of any other parallel invocations of the search
3953	>	* function are ignored.
3954	>	*
3955	>	* @param searchFunction a function returning a non-null
3956	>	* result on success, else null
3957	>	* @return a non-null result from applying the given search
3958	>	* function on each (key, value), or null if none
3959	>	*/
3960	>	public <U> U searchInParallel
3961	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3962	>	return ForkJoinTasks.search
3963	>	(this, searchFunction).invoke();
3964	>	}
3965	>
3966	>	/**
3967	>	* Returns the result of accumulating the given transformation
3968	>	* of all (key, value) pairs using the given reducer to
3969	>	* combine values, or null if none.
3970	>	*
3971	>	* @param transformer a function returning the transformation
3972	>	* for an element, or null if there is no transformation (in
3973	>	* which case it is not combined)
3974	>	* @param reducer a commutative associative combining function
3975	>	* @return the result of accumulating the given transformation
3976	>	* of all (key, value) pairs
3977	>	*/
3978	>	public <U> U reduceInParallel
3979	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3980	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3981	>	return ForkJoinTasks.reduce
3982	>	(this, transformer, reducer).invoke();
3983	>	}
3984	>
3985	>	/**
3986	>	* Returns the result of accumulating the given transformation
3987	>	* of all (key, value) pairs using the given reducer to
3988	>	* combine values, and the given basis as an identity value.
3989	>	*
3990	>	* @param transformer a function returning the transformation
3991	>	* for an element
3992	>	* @param basis the identity (initial default value) for the reduction
3993	>	* @param reducer a commutative associative combining function
3994	>	* @return the result of accumulating the given transformation
3995	>	* of all (key, value) pairs
3996	>	*/
3997	>	public double reduceToDoubleInParallel
3998	>	(ToDoubleBiFunction<? super K, ? super V> transformer,
3999	>	double basis,
4000	>	DoubleBinaryOperator reducer) {
4001	>	return ForkJoinTasks.reduceToDouble
4002	>	(this, transformer, basis, reducer).invoke();
4003	>	}
4004	>
4005	>	/**
4006	>	* Returns the result of accumulating the given transformation
4007	>	* of all (key, value) pairs using the given reducer to
4008	>	* combine values, and the given basis as an identity value.
4009	>	*
4010	>	* @param transformer a function returning the transformation
4011	>	* for an element
4012	>	* @param basis the identity (initial default value) for the reduction
4013	>	* @param reducer a commutative associative combining function
4014	>	* @return the result of accumulating the given transformation
4015	>	* of all (key, value) pairs
4016	>	*/
4017	>	public long reduceToLongInParallel
4018	>	(ToLongBiFunction<? super K, ? super V> transformer,
4019	>	long basis,
4020	>	LongBinaryOperator reducer) {
4021	>	return ForkJoinTasks.reduceToLong
4022	>	(this, transformer, basis, reducer).invoke();
4023	>	}
4024	>
4025	>	/**
4026	>	* Returns the result of accumulating the given transformation
4027	>	* of all (key, value) pairs using the given reducer to
4028	>	* combine values, and the given basis as an identity value.
4029	>	*
4030	>	* @param transformer a function returning the transformation
4031	>	* for an element
4032	>	* @param basis the identity (initial default value) for the reduction
4033	>	* @param reducer a commutative associative combining function
4034	>	* @return the result of accumulating the given transformation
4035	>	* of all (key, value) pairs
4036	>	*/
4037	>	public int reduceToIntInParallel
4038	>	(ToIntBiFunction<? super K, ? super V> transformer,
4039	>	int basis,
4040	>	IntBinaryOperator reducer) {
4041	>	return ForkJoinTasks.reduceToInt
4042	>	(this, transformer, basis, reducer).invoke();
4043	>	}
4044	>
4045	>	/**
4046	>	* Performs the given action for each key.
4047	>	*
4048	>	* @param action the action
4049	>	*/
4050	>	public void forEachKeyInParallel(Consumer<? super K> action) {
4051	>	ForkJoinTasks.forEachKey
4052	>	(this, action).invoke();
4053	>	}
4054	>
4055	>	/**
4056	>	* Performs the given action for each non-null transformation
4057	>	* of each key.
4058	>	*
4059	>	* @param transformer a function returning the transformation
4060	>	* for an element, or null if there is no transformation (in
4061	>	* which case the action is not applied)
4062	>	* @param action the action
4063	>	*/
4064	>	public <U> void forEachKeyInParallel
4065	>	(Function<? super K, ? extends U> transformer,
4066	>	Consumer<? super U> action) {
4067	>	ForkJoinTasks.forEachKey
4068	>	(this, transformer, action).invoke();
4069	>	}
4070	>
4071	>	/**
4072	>	* Returns a non-null result from applying the given search
4073	>	* function on each key, or null if none. Upon success,
4074	>	* further element processing is suppressed and the results of
4075	>	* any other parallel invocations of the search function are
4076	>	* ignored.
4077	>	*
4078	>	* @param searchFunction a function returning a non-null
4079	>	* result on success, else null
4080	>	* @return a non-null result from applying the given search
4081	>	* function on each key, or null if none
4082	>	*/
4083	>	public <U> U searchKeysInParallel
4084	>	(Function<? super K, ? extends U> searchFunction) {
4085	>	return ForkJoinTasks.searchKeys
4086	>	(this, searchFunction).invoke();
4087	>	}
4088	>
4089	>	/**
4090	>	* Returns the result of accumulating all keys using the given
4091	>	* reducer to combine values, or null if none.
4092	>	*
4093	>	* @param reducer a commutative associative combining function
4094	>	* @return the result of accumulating all keys using the given
4095	>	* reducer to combine values, or null if none
4096	>	*/
4097	>	public K reduceKeysInParallel
4098	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
4099	>	return ForkJoinTasks.reduceKeys
4100	>	(this, reducer).invoke();
4101	>	}
4102	>
4103	>	/**
4104	>	* Returns the result of accumulating the given transformation
4105	>	* of all keys using the given reducer to combine values, or
4106	>	* null if none.
4107	>	*
4108	>	* @param transformer a function returning the transformation
4109	>	* for an element, or null if there is no transformation (in
4110	>	* which case it is not combined)
4111	>	* @param reducer a commutative associative combining function
4112	>	* @return the result of accumulating the given transformation
4113	>	* of all keys
4114	>	*/
4115	>	public <U> U reduceKeysInParallel
4116	>	(Function<? super K, ? extends U> transformer,
4117	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4118	>	return ForkJoinTasks.reduceKeys
4119	>	(this, transformer, reducer).invoke();
4120	>	}
4121	>
4122	>	/**
4123	>	* Returns the result of accumulating the given transformation
4124	>	* of all keys using the given reducer to combine values, and
4125	>	* the given basis as an identity value.
4126	>	*
4127	>	* @param transformer a function returning the transformation
4128	>	* for an element
4129	>	* @param basis the identity (initial default value) for the reduction
4130	>	* @param reducer a commutative associative combining function
4131	>	* @return the result of accumulating the given transformation
4132	>	* of all keys
4133	>	*/
4134	>	public double reduceKeysToDoubleInParallel
4135	>	(ToDoubleFunction<? super K> transformer,
4136	>	double basis,
4137	>	DoubleBinaryOperator reducer) {
4138	>	return ForkJoinTasks.reduceKeysToDouble
4139	>	(this, transformer, basis, reducer).invoke();
4140	>	}
4141	>
4142	>	/**
4143	>	* Returns the result of accumulating the given transformation
4144	>	* of all keys using the given reducer to combine values, and
4145	>	* the given basis as an identity value.
4146	>	*
4147	>	* @param transformer a function returning the transformation
4148	>	* for an element
4149	>	* @param basis the identity (initial default value) for the reduction
4150	>	* @param reducer a commutative associative combining function
4151	>	* @return the result of accumulating the given transformation
4152	>	* of all keys
4153	>	*/
4154	>	public long reduceKeysToLongInParallel
4155	>	(ToLongFunction<? super K> transformer,
4156	>	long basis,
4157	>	LongBinaryOperator reducer) {
4158	>	return ForkJoinTasks.reduceKeysToLong
4159	>	(this, transformer, basis, reducer).invoke();
4160	>	}
4161	>
4162	>	/**
4163	>	* Returns the result of accumulating the given transformation
4164	>	* of all keys using the given reducer to combine values, and
4165	>	* the given basis as an identity value.
4166	>	*
4167	>	* @param transformer a function returning the transformation
4168	>	* for an element
4169	>	* @param basis the identity (initial default value) for the reduction
4170	>	* @param reducer a commutative associative combining function
4171	>	* @return the result of accumulating the given transformation
4172	>	* of all keys
4173	>	*/
4174	>	public int reduceKeysToIntInParallel
4175	>	(ToIntFunction<? super K> transformer,
4176	>	int basis,
4177	>	IntBinaryOperator reducer) {
4178	>	return ForkJoinTasks.reduceKeysToInt
4179	>	(this, transformer, basis, reducer).invoke();
4180	>	}
4181	>
4182	>	/**
4183	>	* Performs the given action for each value.
4184	>	*
4185	>	* @param action the action
4186	>	*/
4187	>	public void forEachValueInParallel(Consumer<? super V> action) {
4188	>	ForkJoinTasks.forEachValue
4189	>	(this, action).invoke();
4190	>	}
4191	>
4192	>	/**
4193	>	* Performs the given action for each non-null transformation
4194	>	* of each value.
4195	>	*
4196	>	* @param transformer a function returning the transformation
4197	>	* for an element, or null if there is no transformation (in
4198	>	* which case the action is not applied)
4199	>	*/
4200	>	public <U> void forEachValueInParallel
4201	>	(Function<? super V, ? extends U> transformer,
4202	>	Consumer<? super U> action) {
4203	>	ForkJoinTasks.forEachValue
4204	>	(this, transformer, action).invoke();
4205	>	}
4206	>
4207	>	/**
4208	>	* Returns a non-null result from applying the given search
4209	>	* function on each value, or null if none.  Upon success,
4210	>	* further element processing is suppressed and the results of
4211	>	* any other parallel invocations of the search function are
4212	>	* ignored.
4213	>	*
4214	>	* @param searchFunction a function returning a non-null
4215	>	* result on success, else null
4216	>	* @return a non-null result from applying the given search
4217	>	* function on each value, or null if none
4218	>	*/
4219	>	public <U> U searchValuesInParallel
4220	>	(Function<? super V, ? extends U> searchFunction) {
4221	>	return ForkJoinTasks.searchValues
4222	>	(this, searchFunction).invoke();
4223	>	}
4224	>
4225	>	/**
4226	>	* Returns the result of accumulating all values using the
4227	>	* given reducer to combine values, or null if none.
4228	>	*
4229	>	* @param reducer a commutative associative combining function
4230	>	* @return the result of accumulating all values
4231	>	*/
4232	>	public V reduceValuesInParallel
4233	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
4234	>	return ForkJoinTasks.reduceValues
4235	>	(this, reducer).invoke();
4236	>	}
4237	>
4238	>	/**
4239	>	* Returns the result of accumulating the given transformation
4240	>	* of all values using the given reducer to combine values, or
4241	>	* null if none.
4242	>	*
4243	>	* @param transformer a function returning the transformation
4244	>	* for an element, or null if there is no transformation (in
4245	>	* which case it is not combined)
4246	>	* @param reducer a commutative associative combining function
4247	>	* @return the result of accumulating the given transformation
4248	>	* of all values
4249	>	*/
4250	>	public <U> U reduceValuesInParallel
4251	>	(Function<? super V, ? extends U> transformer,
4252	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4253	>	return ForkJoinTasks.reduceValues
4254	>	(this, transformer, reducer).invoke();
4255	>	}
4256	>
4257	>	/**
4258	>	* Returns the result of accumulating the given transformation
4259	>	* of all values using the given reducer to combine values,
4260	>	* and the given basis as an identity value.
4261	>	*
4262	>	* @param transformer a function returning the transformation
4263	>	* for an element
4264	>	* @param basis the identity (initial default value) for the reduction
4265	>	* @param reducer a commutative associative combining function
4266	>	* @return the result of accumulating the given transformation
4267	>	* of all values
4268	>	*/
4269	>	public double reduceValuesToDoubleInParallel
4270	>	(ToDoubleFunction<? super V> transformer,
4271	>	double basis,
4272	>	DoubleBinaryOperator reducer) {
4273	>	return ForkJoinTasks.reduceValuesToDouble
4274	>	(this, transformer, basis, reducer).invoke();
4275	>	}
4276	>
4277	>	/**
4278	>	* Returns the result of accumulating the given transformation
4279	>	* of all values using the given reducer to combine values,
4280	>	* and the given basis as an identity value.
4281	>	*
4282	>	* @param transformer a function returning the transformation
4283	>	* for an element
4284	>	* @param basis the identity (initial default value) for the reduction
4285	>	* @param reducer a commutative associative combining function
4286	>	* @return the result of accumulating the given transformation
4287	>	* of all values
4288	>	*/
4289	>	public long reduceValuesToLongInParallel
4290	>	(ToLongFunction<? super V> transformer,
4291	>	long basis,
4292	>	LongBinaryOperator reducer) {
4293	>	return ForkJoinTasks.reduceValuesToLong
4294	>	(this, transformer, basis, reducer).invoke();
4295	>	}
4296	>
4297	>	/**
4298	>	* Returns the result of accumulating the given transformation
4299	>	* of all values using the given reducer to combine values,
4300	>	* and the given basis as an identity value.
4301	>	*
4302	>	* @param transformer a function returning the transformation
4303	>	* for an element
4304	>	* @param basis the identity (initial default value) for the reduction
4305	>	* @param reducer a commutative associative combining function
4306	>	* @return the result of accumulating the given transformation
4307	>	* of all values
4308	>	*/
4309	>	public int reduceValuesToIntInParallel
4310	>	(ToIntFunction<? super V> transformer,
4311	>	int basis,
4312	>	IntBinaryOperator reducer) {
4313	>	return ForkJoinTasks.reduceValuesToInt
4314	>	(this, transformer, basis, reducer).invoke();
4315	>	}
4316	>
4317	>	/**
4318	>	* Performs the given action for each entry.
4319	>	*
4320	>	* @param action the action
4321	>	*/
4322	>	public void forEachEntryInParallel(Consumer<? super Map.Entry<K,V>> action) {
4323	>	ForkJoinTasks.forEachEntry
4324	>	(this, action).invoke();
4325	>	}
4326	>
4327	>	/**
4328	>	* Performs the given action for each non-null transformation
4329	>	* of each entry.
4330	>	*
4331	>	* @param transformer a function returning the transformation
4332	>	* for an element, or null if there is no transformation (in
4333	>	* which case the action is not applied)
4334	>	* @param action the action
4335	>	*/
4336	>	public <U> void forEachEntryInParallel
4337	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4338	>	Consumer<? super U> action) {
4339	>	ForkJoinTasks.forEachEntry
4340	>	(this, transformer, action).invoke();
4341	>	}
4342	>
4343	>	/**
4344	>	* Returns a non-null result from applying the given search
4345	>	* function on each entry, or null if none.  Upon success,
4346	>	* further element processing is suppressed and the results of
4347	>	* any other parallel invocations of the search function are
4348	>	* ignored.
4349	>	*
4350	>	* @param searchFunction a function returning a non-null
4351	>	* result on success, else null
4352	>	* @return a non-null result from applying the given search
4353	>	* function on each entry, or null if none
4354	>	*/
4355	>	public <U> U searchEntriesInParallel
4356	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4357	>	return ForkJoinTasks.searchEntries
4358	>	(this, searchFunction).invoke();
4359	>	}
4360	>
4361	>	/**
4362	>	* Returns the result of accumulating all entries using the
4363	>	* given reducer to combine values, or null if none.
4364	>	*
4365	>	* @param reducer a commutative associative combining function
4366	>	* @return the result of accumulating all entries
4367	>	*/
4368	>	public Map.Entry<K,V> reduceEntriesInParallel
4369	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4370	>	return ForkJoinTasks.reduceEntries
4371	>	(this, reducer).invoke();
4372	>	}
4373	>
4374	>	/**
4375	>	* Returns the result of accumulating the given transformation
4376	>	* of all entries using the given reducer to combine values,
4377	>	* or null if none.
4378	>	*
4379	>	* @param transformer a function returning the transformation
4380	>	* for an element, or null if there is no transformation (in
4381	>	* which case it is not combined)
4382	>	* @param reducer a commutative associative combining function
4383	>	* @return the result of accumulating the given transformation
4384	>	* of all entries
4385	>	*/
4386	>	public <U> U reduceEntriesInParallel
4387	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4388	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4389	>	return ForkJoinTasks.reduceEntries
4390	>	(this, transformer, reducer).invoke();
4391	>	}
4392	>
4393	>	/**
4394	>	* Returns the result of accumulating the given transformation
4395	>	* of all entries using the given reducer to combine values,
4396	>	* and the given basis as an identity value.
4397	>	*
4398	>	* @param transformer a function returning the transformation
4399	>	* for an element
4400	>	* @param basis the identity (initial default value) for the reduction
4401	>	* @param reducer a commutative associative combining function
4402	>	* @return the result of accumulating the given transformation
4403	>	* of all entries
4404	>	*/
4405	>	public double reduceEntriesToDoubleInParallel
4406	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
4407	>	double basis,
4408	>	DoubleBinaryOperator reducer) {
4409	>	return ForkJoinTasks.reduceEntriesToDouble
4410	>	(this, transformer, basis, reducer).invoke();
4411	>	}
4412	>
4413	>	/**
4414	>	* Returns the result of accumulating the given transformation
4415	>	* of all entries using the given reducer to combine values,
4416	>	* and the given basis as an identity value.
4417	>	*
4418	>	* @param transformer a function returning the transformation
4419	>	* for an element
4420	>	* @param basis the identity (initial default value) for the reduction
4421	>	* @param reducer a commutative associative combining function
4422	>	* @return the result of accumulating the given transformation
4423	>	* of all entries
4424	>	*/
4425	>	public long reduceEntriesToLongInParallel
4426	>	(ToLongFunction<Map.Entry<K,V>> transformer,
4427	>	long basis,
4428	>	LongBinaryOperator reducer) {
4429	>	return ForkJoinTasks.reduceEntriesToLong
4430	>	(this, transformer, basis, reducer).invoke();
4431	>	}
4432	>
4433	>	/**
4434	>	* Returns the result of accumulating the given transformation
4435	>	* of all entries using the given reducer to combine values,
4436	>	* and the given basis as an identity value.
4437	>	*
4438	>	* @param transformer a function returning the transformation
4439	>	* for an element
4440	>	* @param basis the identity (initial default value) for the reduction
4441	>	* @param reducer a commutative associative combining function
4442	>	* @return the result of accumulating the given transformation
4443	>	* of all entries
4444	>	*/
4445	>	public int reduceEntriesToIntInParallel
4446	>	(ToIntFunction<Map.Entry<K,V>> transformer,
4447	>	int basis,
4448	>	IntBinaryOperator reducer) {
4449	>	return ForkJoinTasks.reduceEntriesToInt
4450	>	(this, transformer, basis, reducer).invoke();
4451	>	}
4452	>
4453	>
4454	>	/* ----------------Views -------------- */
4455	>
4456	>	/**
4457	>	* Base class for views.
4458	>	*/
4459	>	abstract static class CHMView<K, V> implements java.io.Serializable {
4460	>	private static final long serialVersionUID = 7249069246763182397L;
4461	>	final ConcurrentHashMap<K, V> map;
4462	>	CHMView(ConcurrentHashMap<K, V> map)  { this.map = map; }
4463	>
4464	>	/**
4465	>	* Returns the map backing this view.
4466	>	*
4467	>	* @return the map backing this view
4468	>	*/
4469	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4470	>
4471	>	public final int size()                 { return map.size(); }
4472	>	public final boolean isEmpty()          { return map.isEmpty(); }
4473	>	public final void clear()               { map.clear(); }
4474	>
4475	>	// implementations below rely on concrete classes supplying these
4476	>	public abstract Iterator<?> iterator();
4477	>	public abstract boolean contains(Object o);
4478	>	public abstract boolean remove(Object o);
4479	>
4480	>	private static final String oomeMsg = "Required array size too large";
4481	>
4482	>	public final Object[] toArray() {
4483	>	long sz = map.mappingCount();
4484	>	if (sz > (long)(MAX_ARRAY_SIZE))
4485	>	throw new OutOfMemoryError(oomeMsg);
4486	>	int n = (int)sz;
4487	>	Object[] r = new Object[n];
4488	>	int i = 0;
4489	>	Iterator<?> it = iterator();
4490	>	while (it.hasNext()) {
4491	>	if (i == n) {
4492	>	if (n >= MAX_ARRAY_SIZE)
4493	>	throw new OutOfMemoryError(oomeMsg);
4494	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4495	>	n = MAX_ARRAY_SIZE;
4496	>	else
4497	>	n += (n >>> 1) + 1;
4498	>	r = Arrays.copyOf(r, n);
4499	>	}
4500	>	r[i++] = it.next();
4501	>	}
4502	>	return (i == n) ? r : Arrays.copyOf(r, i);
4503	>	}
4504	>
4505	>	@SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4506	>	long sz = map.mappingCount();
4507	>	if (sz > (long)(MAX_ARRAY_SIZE))
4508	>	throw new OutOfMemoryError(oomeMsg);
4509	>	int m = (int)sz;
4510	>	T[] r = (a.length >= m) ? a :
4511	>	(T[])java.lang.reflect.Array
4512	>	.newInstance(a.getClass().getComponentType(), m);
4513	>	int n = r.length;
4514	>	int i = 0;
4515	>	Iterator<?> it = iterator();
4516	>	while (it.hasNext()) {
4517	>	if (i == n) {
4518	>	if (n >= MAX_ARRAY_SIZE)
4519	>	throw new OutOfMemoryError(oomeMsg);
4520	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4521	>	n = MAX_ARRAY_SIZE;
4522	>	else
4523	>	n += (n >>> 1) + 1;
4524	>	r = Arrays.copyOf(r, n);
4525	>	}
4526	>	r[i++] = (T)it.next();
4527	>	}
4528	>	if (a == r && i < n) {
4529	>	r[i] = null; // null-terminate
4530	>	return r;
4531	>	}
4532	>	return (i == n) ? r : Arrays.copyOf(r, i);
4533	>	}
4534	>
4535	>	public final int hashCode() {
4536	>	int h = 0;
4537	>	for (Iterator<?> it = iterator(); it.hasNext();)
4538	>	h += it.next().hashCode();
4539	>	return h;
4540	>	}
4541	>
4542	>	public final String toString() {
4543	>	StringBuilder sb = new StringBuilder();
4544	>	sb.append('[');
4545	>	Iterator<?> it = iterator();
4546	>	if (it.hasNext()) {
4547	>	for (;;) {
4548	>	Object e = it.next();
4549	>	sb.append(e == this ? "(this Collection)" : e);
4550	>	if (!it.hasNext())
4551	>	break;
4552	>	sb.append(',').append(' ');
4553	>	}
4554	>	}
4555	>	return sb.append(']').toString();
4556	>	}
4557	>
4558	>	public final boolean containsAll(Collection<?> c) {
4559	>	if (c != this) {
4560	>	for (Iterator<?> it = c.iterator(); it.hasNext();) {
4561	>	Object e = it.next();
4562	>	if (e == null || !contains(e))
4563	>	return false;
4564	>	}
4565	>	}
4566	>	return true;
4567	>	}
4568	>
4569	>	public final boolean removeAll(Collection<?> c) {
4570	>	boolean modified = false;
4571	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4572	>	if (c.contains(it.next())) {
4573	>	it.remove();
4574	>	modified = true;
4575	>	}
4576	>	}
4577	>	return modified;
4578	>	}
4579	>
4580	>	public final boolean retainAll(Collection<?> c) {
4581	>	boolean modified = false;
4582	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4583	>	if (!c.contains(it.next())) {
4584	>	it.remove();
4585	>	modified = true;
4586	>	}
4587	>	}
4588	>	return modified;
4589	>	}
4590	>
4591	>	}
4592	>
4593	>	/**
4594	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4595	>	* which additions may optionally be enabled by mapping to a
4596	>	* common value.  This class cannot be directly instantiated. See
4597	>	* {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4598	>	* {@link #newKeySet(int)}.
4599	>	*/
4600	>	public static class KeySetView<K,V> extends CHMView<K,V>
4601	>	implements Set<K>, java.io.Serializable {
4602	>	private static final long serialVersionUID = 7249069246763182397L;
4603	>	private final V value;
4604	>	KeySetView(ConcurrentHashMap<K, V> map, V value) {  // non-public
4605	>	super(map);
4606	>	this.value = value;
4607	>	}
4608	>
4609	>	/**
4610	>	* Returns the default mapped value for additions,
4611	>	* or {@code null} if additions are not supported.
4612	>	*
4613	>	* @return the default mapped value for additions, or {@code null}
4614	>	* if not supported
4615	>	*/
4616	>	public V getMappedValue() { return value; }
4617	>
4618	>	// implement Set API
4619	>
4620	>	public boolean contains(Object o) { return map.containsKey(o); }
4621	>	public boolean remove(Object o)   { return map.remove(o) != null; }
4622	>
4623	>	/**
4624	>	* Returns a "weakly consistent" iterator that will never
4625	>	* throw {@link ConcurrentModificationException}, and
4626	>	* guarantees to traverse elements as they existed upon
4627	>	* construction of the iterator, and may (but is not
4628	>	* guaranteed to) reflect any modifications subsequent to
4629	>	* construction.
4630	>	*
4631	>	* @return an iterator over the keys of this map
4632	>	*/
4633	>	public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4634	>	public boolean add(K e) {
4635	>	V v;
4636	>	if ((v = value) == null)
4637	>	throw new UnsupportedOperationException();
4638	>	if (e == null)
4639	>	throw new NullPointerException();
4640	>	return map.internalPut(e, v, true) == null;
4641	>	}
4642	>	public boolean addAll(Collection<? extends K> c) {
4643	>	boolean added = false;
4644	>	V v;
4645	>	if ((v = value) == null)
4646	>	throw new UnsupportedOperationException();
4647	>	for (K e : c) {
4648	>	if (e == null)
4649	>	throw new NullPointerException();
4650	>	if (map.internalPut(e, v, true) == null)
4651	>	added = true;
4652	>	}
4653	>	return added;
4654	>	}
4655	>	public boolean equals(Object o) {
4656	>	Set<?> c;
4657	>	return ((o instanceof Set) &&
4658	>	((c = (Set<?>)o) == this ||
4659	>	(containsAll(c) && c.containsAll(this))));
4660	>	}
4661	>
4662	>	public Stream<K> stream() {
4663	>	return Streams.stream(() -> new KeyIterator<K,V>(map), 0);
4664	>	}
4665	>	public Stream<K> parallelStream() {
4666	>	return Streams.parallelStream(() -> new KeyIterator<K,V>(map, null),
4667	>	0);
4668	>	}
4669	>	}
4670	>
4671	>	/**
4672	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4673	>	* values, in which additions are disabled. This class cannot be
4674	>	* directly instantiated. See {@link #values},
4675	>	*
4676	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4677	>	* that will never throw {@link ConcurrentModificationException},
4678	>	* and guarantees to traverse elements as they existed upon
4679	>	* construction of the iterator, and may (but is not guaranteed to)
4680	>	* reflect any modifications subsequent to construction.
4681	>	*/
4682	>	public static final class ValuesView<K,V> extends CHMView<K,V>
4683	>	implements Collection<V> {
4684	>	private static final long serialVersionUID = 2249069246763182397L;
4685	>	ValuesView(ConcurrentHashMap<K, V> map)   { super(map); }
4686	>	public final boolean contains(Object o) { return map.containsValue(o); }
4687	>	public final boolean remove(Object o) {
4688	>	if (o != null) {
4689	>	Iterator<V> it = new ValueIterator<K,V>(map);
4690	>	while (it.hasNext()) {
4691	>	if (o.equals(it.next())) {
4692	>	it.remove();
4693	>	return true;
4694		}
4695		}
1249	–	} finally {
1250	–	seg.unlock();
4696		}
4697	+	return false;
4698		}
4699	<	s.writeObject(null);
4700	<	s.writeObject(null);
4699	>
4700	>	/**
4701	>	* Returns a "weakly consistent" iterator that will never
4702	>	* throw {@link ConcurrentModificationException}, and
4703	>	* guarantees to traverse elements as they existed upon
4704	>	* construction of the iterator, and may (but is not
4705	>	* guaranteed to) reflect any modifications subsequent to
4706	>	* construction.
4707	>	*
4708	>	* @return an iterator over the values of this map
4709	>	*/
4710	>	public final Iterator<V> iterator() {
4711	>	return new ValueIterator<K,V>(map);
4712	>	}
4713	>	public final boolean add(V e) {
4714	>	throw new UnsupportedOperationException();
4715	>	}
4716	>	public final boolean addAll(Collection<? extends V> c) {
4717	>	throw new UnsupportedOperationException();
4718	>	}
4719	>
4720	>	public Stream<V> stream() {
4721	>	return Streams.stream(() -> new ValueIterator<K,V>(map), 0);
4722	>	}
4723	>
4724	>	public Stream<V> parallelStream() {
4725	>	return Streams.parallelStream(() -> new ValueIterator<K,V>(map, null),
4726	>	0);
4727	>	}
4728	>
4729		}
4730
4731		/**
4732	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
4733	<	* stream (i.e., deserialize it).
4734	<	* @param s the stream
4732	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4733	>	* entries.  This class cannot be directly instantiated. See
4734	>	* {@link #entrySet}.
4735		*/
4736	<	private void readObject(java.io.ObjectInputStream s)
4737	<	throws IOException, ClassNotFoundException  {
4738	<	s.defaultReadObject();
4736	>	public static final class EntrySetView<K,V> extends CHMView<K,V>
4737	>	implements Set<Map.Entry<K,V>> {
4738	>	private static final long serialVersionUID = 2249069246763182397L;
4739	>	EntrySetView(ConcurrentHashMap<K, V> map) { super(map); }
4740	>	public final boolean contains(Object o) {
4741	>	Object k, v, r; Map.Entry<?,?> e;
4742	>	return ((o instanceof Map.Entry) &&
4743	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4744	>	(r = map.get(k)) != null &&
4745	>	(v = e.getValue()) != null &&
4746	>	(v == r || v.equals(r)));
4747	>	}
4748	>	public final boolean remove(Object o) {
4749	>	Object k, v; Map.Entry<?,?> e;
4750	>	return ((o instanceof Map.Entry) &&
4751	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4752	>	(v = e.getValue()) != null &&
4753	>	map.remove(k, v));
4754	>	}
4755	>
4756	>	/**
4757	>	* Returns a "weakly consistent" iterator that will never
4758	>	* throw {@link ConcurrentModificationException}, and
4759	>	* guarantees to traverse elements as they existed upon
4760	>	* construction of the iterator, and may (but is not
4761	>	* guaranteed to) reflect any modifications subsequent to
4762	>	* construction.
4763	>	*
4764	>	* @return an iterator over the entries of this map
4765	>	*/
4766	>	public final Iterator<Map.Entry<K,V>> iterator() {
4767	>	return new EntryIterator<K,V>(map);
4768	>	}
4769
4770	<	// Initialize each segment to be minimally sized, and let grow.
4771	<	for (int i = 0; i < segments.length; ++i) {
4772	<	segments[i].setTable(new HashEntry[1]);
4770	>	public final boolean add(Entry<K,V> e) {
4771	>	K key = e.getKey();
4772	>	V value = e.getValue();
4773	>	if (key == null || value == null)
4774	>	throw new NullPointerException();
4775	>	return map.internalPut(key, value, false) == null;
4776	>	}
4777	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4778	>	boolean added = false;
4779	>	for (Entry<K,V> e : c) {
4780	>	if (add(e))
4781	>	added = true;
4782	>	}
4783	>	return added;
4784	>	}
4785	>	public boolean equals(Object o) {
4786	>	Set<?> c;
4787	>	return ((o instanceof Set) &&
4788	>	((c = (Set<?>)o) == this ||
4789	>	(containsAll(c) && c.containsAll(this))));
4790		}
4791
4792	<	// Read the keys and values, and put the mappings in the table
4793	<	for (;;) {
4794	<	K key = (K) s.readObject();
4795	<	V value = (V) s.readObject();
4796	<	if (key == null)
4797	<	break;
4798	<	put(key, value);
4792	>	public Stream<Map.Entry<K,V>> stream() {
4793	>	return Streams.stream(() -> new EntryIterator<K,V>(map), 0);
4794	>	}
4795	>
4796	>	public Stream<Map.Entry<K,V>> parallelStream() {
4797	>	return Streams.parallelStream(() -> new EntryIterator<K,V>(map, null),
4798	>	0);
4799		}
4800		}
4801	+
4802	+	// ---------------------------------------------------------------------
4803	+
4804	+	/**
4805	+	* Predefined tasks for performing bulk parallel operations on
4806	+	* ConcurrentHashMaps. These tasks follow the forms and rules used
4807	+	* for bulk operations. Each method has the same name, but returns
4808	+	* a task rather than invoking it. These methods may be useful in
4809	+	* custom applications such as submitting a task without waiting
4810	+	* for completion, using a custom pool, or combining with other
4811	+	* tasks.
4812	+	*/
4813	+	public static class ForkJoinTasks {
4814	+	private ForkJoinTasks() {}
4815	+
4816	+	/**
4817	+	* Returns a task that when invoked, performs the given
4818	+	* action for each (key, value)
4819	+	*
4820	+	* @param map the map
4821	+	* @param action the action
4822	+	* @return the task
4823	+	*/
4824	+	public static <K,V> ForkJoinTask<Void> forEach
4825	+	(ConcurrentHashMap<K,V> map,
4826	+	BiConsumer<? super K, ? super V> action) {
4827	+	if (action == null) throw new NullPointerException();
4828	+	return new ForEachMappingTask<K,V>(map, null, -1, action);
4829	+	}
4830	+
4831	+	/**
4832	+	* Returns a task that when invoked, performs the given
4833	+	* action for each non-null transformation of each (key, value)
4834	+	*
4835	+	* @param map the map
4836	+	* @param transformer a function returning the transformation
4837	+	* for an element, or null if there is no transformation (in
4838	+	* which case the action is not applied)
4839	+	* @param action the action
4840	+	* @return the task
4841	+	*/
4842	+	public static <K,V,U> ForkJoinTask<Void> forEach
4843	+	(ConcurrentHashMap<K,V> map,
4844	+	BiFunction<? super K, ? super V, ? extends U> transformer,
4845	+	Consumer<? super U> action) {
4846	+	if (transformer == null || action == null)
4847	+	throw new NullPointerException();
4848	+	return new ForEachTransformedMappingTask<K,V,U>
4849	+	(map, null, -1, transformer, action);
4850	+	}
4851	+
4852	+	/**
4853	+	* Returns a task that when invoked, returns a non-null result
4854	+	* from applying the given search function on each (key,
4855	+	* value), or null if none. Upon success, further element
4856	+	* processing is suppressed and the results of any other
4857	+	* parallel invocations of the search function are ignored.
4858	+	*
4859	+	* @param map the map
4860	+	* @param searchFunction a function returning a non-null
4861	+	* result on success, else null
4862	+	* @return the task
4863	+	*/
4864	+	public static <K,V,U> ForkJoinTask<U> search
4865	+	(ConcurrentHashMap<K,V> map,
4866	+	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
4867	+	if (searchFunction == null) throw new NullPointerException();
4868	+	return new SearchMappingsTask<K,V,U>
4869	+	(map, null, -1, searchFunction,
4870	+	new AtomicReference<U>());
4871	+	}
4872	+
4873	+	/**
4874	+	* Returns a task that when invoked, returns the result of
4875	+	* accumulating the given transformation of all (key, value) pairs
4876	+	* using the given reducer to combine values, or null if none.
4877	+	*
4878	+	* @param map the map
4879	+	* @param transformer a function returning the transformation
4880	+	* for an element, or null if there is no transformation (in
4881	+	* which case it is not combined)
4882	+	* @param reducer a commutative associative combining function
4883	+	* @return the task
4884	+	*/
4885	+	public static <K,V,U> ForkJoinTask<U> reduce
4886	+	(ConcurrentHashMap<K,V> map,
4887	+	BiFunction<? super K, ? super V, ? extends U> transformer,
4888	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4889	+	if (transformer == null || reducer == null)
4890	+	throw new NullPointerException();
4891	+	return new MapReduceMappingsTask<K,V,U>
4892	+	(map, null, -1, null, transformer, reducer);
4893	+	}
4894	+
4895	+	/**
4896	+	* Returns a task that when invoked, returns the result of
4897	+	* accumulating the given transformation of all (key, value) pairs
4898	+	* using the given reducer to combine values, and the given
4899	+	* basis as an identity value.
4900	+	*
4901	+	* @param map the map
4902	+	* @param transformer a function returning the transformation
4903	+	* for an element
4904	+	* @param basis the identity (initial default value) for the reduction
4905	+	* @param reducer a commutative associative combining function
4906	+	* @return the task
4907	+	*/
4908	+	public static <K,V> ForkJoinTask<Double> reduceToDouble
4909	+	(ConcurrentHashMap<K,V> map,
4910	+	ToDoubleBiFunction<? super K, ? super V> transformer,
4911	+	double basis,
4912	+	DoubleBinaryOperator reducer) {
4913	+	if (transformer == null || reducer == null)
4914	+	throw new NullPointerException();
4915	+	return new MapReduceMappingsToDoubleTask<K,V>
4916	+	(map, null, -1, null, transformer, basis, reducer);
4917	+	}
4918	+
4919	+	/**
4920	+	* Returns a task that when invoked, returns the result of
4921	+	* accumulating the given transformation of all (key, value) pairs
4922	+	* using the given reducer to combine values, and the given
4923	+	* basis as an identity value.
4924	+	*
4925	+	* @param map the map
4926	+	* @param transformer a function returning the transformation
4927	+	* for an element
4928	+	* @param basis the identity (initial default value) for the reduction
4929	+	* @param reducer a commutative associative combining function
4930	+	* @return the task
4931	+	*/
4932	+	public static <K,V> ForkJoinTask<Long> reduceToLong
4933	+	(ConcurrentHashMap<K,V> map,
4934	+	ToLongBiFunction<? super K, ? super V> transformer,
4935	+	long basis,
4936	+	LongBinaryOperator reducer) {
4937	+	if (transformer == null || reducer == null)
4938	+	throw new NullPointerException();
4939	+	return new MapReduceMappingsToLongTask<K,V>
4940	+	(map, null, -1, null, transformer, basis, reducer);
4941	+	}
4942	+
4943	+	/**
4944	+	* Returns a task that when invoked, returns the result of
4945	+	* accumulating the given transformation of all (key, value) pairs
4946	+	* using the given reducer to combine values, and the given
4947	+	* basis as an identity value.
4948	+	*
4949	+	* @param transformer a function returning the transformation
4950	+	* for an element
4951	+	* @param basis the identity (initial default value) for the reduction
4952	+	* @param reducer a commutative associative combining function
4953	+	* @return the task
4954	+	*/
4955	+	public static <K,V> ForkJoinTask<Integer> reduceToInt
4956	+	(ConcurrentHashMap<K,V> map,
4957	+	ToIntBiFunction<? super K, ? super V> transformer,
4958	+	int basis,
4959	+	IntBinaryOperator reducer) {
4960	+	if (transformer == null || reducer == null)
4961	+	throw new NullPointerException();
4962	+	return new MapReduceMappingsToIntTask<K,V>
4963	+	(map, null, -1, null, transformer, basis, reducer);
4964	+	}
4965	+
4966	+	/**
4967	+	* Returns a task that when invoked, performs the given action
4968	+	* for each key.
4969	+	*
4970	+	* @param map the map
4971	+	* @param action the action
4972	+	* @return the task
4973	+	*/
4974	+	public static <K,V> ForkJoinTask<Void> forEachKey
4975	+	(ConcurrentHashMap<K,V> map,
4976	+	Consumer<? super K> action) {
4977	+	if (action == null) throw new NullPointerException();
4978	+	return new ForEachKeyTask<K,V>(map, null, -1, action);
4979	+	}
4980	+
4981	+	/**
4982	+	* Returns a task that when invoked, performs the given action
4983	+	* for each non-null transformation of each key.
4984	+	*
4985	+	* @param map the map
4986	+	* @param transformer a function returning the transformation
4987	+	* for an element, or null if there is no transformation (in
4988	+	* which case the action is not applied)
4989	+	* @param action the action
4990	+	* @return the task
4991	+	*/
4992	+	public static <K,V,U> ForkJoinTask<Void> forEachKey
4993	+	(ConcurrentHashMap<K,V> map,
4994	+	Function<? super K, ? extends U> transformer,
4995	+	Consumer<? super U> action) {
4996	+	if (transformer == null || action == null)
4997	+	throw new NullPointerException();
4998	+	return new ForEachTransformedKeyTask<K,V,U>
4999	+	(map, null, -1, transformer, action);
5000	+	}
5001	+
5002	+	/**
5003	+	* Returns a task that when invoked, returns a non-null result
5004	+	* from applying the given search function on each key, or
5005	+	* null if none.  Upon success, further element processing is
5006	+	* suppressed and the results of any other parallel
5007	+	* invocations of the search function are ignored.
5008	+	*
5009	+	* @param map the map
5010	+	* @param searchFunction a function returning a non-null
5011	+	* result on success, else null
5012	+	* @return the task
5013	+	*/
5014	+	public static <K,V,U> ForkJoinTask<U> searchKeys
5015	+	(ConcurrentHashMap<K,V> map,
5016	+	Function<? super K, ? extends U> searchFunction) {
5017	+	if (searchFunction == null) throw new NullPointerException();
5018	+	return new SearchKeysTask<K,V,U>
5019	+	(map, null, -1, searchFunction,
5020	+	new AtomicReference<U>());
5021	+	}
5022	+
5023	+	/**
5024	+	* Returns a task that when invoked, returns the result of
5025	+	* accumulating all keys using the given reducer to combine
5026	+	* values, or null if none.
5027	+	*
5028	+	* @param map the map
5029	+	* @param reducer a commutative associative combining function
5030	+	* @return the task
5031	+	*/
5032	+	public static <K,V> ForkJoinTask<K> reduceKeys
5033	+	(ConcurrentHashMap<K,V> map,
5034	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5035	+	if (reducer == null) throw new NullPointerException();
5036	+	return new ReduceKeysTask<K,V>
5037	+	(map, null, -1, null, reducer);
5038	+	}
5039	+
5040	+	/**
5041	+	* Returns a task that when invoked, returns the result of
5042	+	* accumulating the given transformation of all keys using the given
5043	+	* reducer to combine values, or null if none.
5044	+	*
5045	+	* @param map the map
5046	+	* @param transformer a function returning the transformation
5047	+	* for an element, or null if there is no transformation (in
5048	+	* which case it is not combined)
5049	+	* @param reducer a commutative associative combining function
5050	+	* @return the task
5051	+	*/
5052	+	public static <K,V,U> ForkJoinTask<U> reduceKeys
5053	+	(ConcurrentHashMap<K,V> map,
5054	+	Function<? super K, ? extends U> transformer,
5055	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5056	+	if (transformer == null || reducer == null)
5057	+	throw new NullPointerException();
5058	+	return new MapReduceKeysTask<K,V,U>
5059	+	(map, null, -1, null, transformer, reducer);
5060	+	}
5061	+
5062	+	/**
5063	+	* Returns a task that when invoked, returns the result of
5064	+	* accumulating the given transformation of all keys using the given
5065	+	* reducer to combine values, and the given basis as an
5066	+	* identity value.
5067	+	*
5068	+	* @param map the map
5069	+	* @param transformer a function returning the transformation
5070	+	* for an element
5071	+	* @param basis the identity (initial default value) for the reduction
5072	+	* @param reducer a commutative associative combining function
5073	+	* @return the task
5074	+	*/
5075	+	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
5076	+	(ConcurrentHashMap<K,V> map,
5077	+	ToDoubleFunction<? super K> transformer,
5078	+	double basis,
5079	+	DoubleBinaryOperator reducer) {
5080	+	if (transformer == null || reducer == null)
5081	+	throw new NullPointerException();
5082	+	return new MapReduceKeysToDoubleTask<K,V>
5083	+	(map, null, -1, null, transformer, basis, reducer);
5084	+	}
5085	+
5086	+	/**
5087	+	* Returns a task that when invoked, returns the result of
5088	+	* accumulating the given transformation of all keys using the given
5089	+	* reducer to combine values, and the given basis as an
5090	+	* identity value.
5091	+	*
5092	+	* @param map the map
5093	+	* @param transformer a function returning the transformation
5094	+	* for an element
5095	+	* @param basis the identity (initial default value) for the reduction
5096	+	* @param reducer a commutative associative combining function
5097	+	* @return the task
5098	+	*/
5099	+	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
5100	+	(ConcurrentHashMap<K,V> map,
5101	+	ToLongFunction<? super K> transformer,
5102	+	long basis,
5103	+	LongBinaryOperator reducer) {
5104	+	if (transformer == null || reducer == null)
5105	+	throw new NullPointerException();
5106	+	return new MapReduceKeysToLongTask<K,V>
5107	+	(map, null, -1, null, transformer, basis, reducer);
5108	+	}
5109	+
5110	+	/**
5111	+	* Returns a task that when invoked, returns the result of
5112	+	* accumulating the given transformation of all keys using the given
5113	+	* reducer to combine values, and the given basis as an
5114	+	* identity value.
5115	+	*
5116	+	* @param map the map
5117	+	* @param transformer a function returning the transformation
5118	+	* for an element
5119	+	* @param basis the identity (initial default value) for the reduction
5120	+	* @param reducer a commutative associative combining function
5121	+	* @return the task
5122	+	*/
5123	+	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5124	+	(ConcurrentHashMap<K,V> map,
5125	+	ToIntFunction<? super K> transformer,
5126	+	int basis,
5127	+	IntBinaryOperator reducer) {
5128	+	if (transformer == null || reducer == null)
5129	+	throw new NullPointerException();
5130	+	return new MapReduceKeysToIntTask<K,V>
5131	+	(map, null, -1, null, transformer, basis, reducer);
5132	+	}
5133	+
5134	+	/**
5135	+	* Returns a task that when invoked, performs the given action
5136	+	* for each value.
5137	+	*
5138	+	* @param map the map
5139	+	* @param action the action
5140	+	* @return the task
5141	+	*/
5142	+	public static <K,V> ForkJoinTask<Void> forEachValue
5143	+	(ConcurrentHashMap<K,V> map,
5144	+	Consumer<? super V> action) {
5145	+	if (action == null) throw new NullPointerException();
5146	+	return new ForEachValueTask<K,V>(map, null, -1, action);
5147	+	}
5148	+
5149	+	/**
5150	+	* Returns a task that when invoked, performs the given action
5151	+	* for each non-null transformation of each value.
5152	+	*
5153	+	* @param map the map
5154	+	* @param transformer a function returning the transformation
5155	+	* for an element, or null if there is no transformation (in
5156	+	* which case the action is not applied)
5157	+	* @param action the action
5158	+	* @return the task
5159	+	*/
5160	+	public static <K,V,U> ForkJoinTask<Void> forEachValue
5161	+	(ConcurrentHashMap<K,V> map,
5162	+	Function<? super V, ? extends U> transformer,
5163	+	Consumer<? super U> action) {
5164	+	if (transformer == null || action == null)
5165	+	throw new NullPointerException();
5166	+	return new ForEachTransformedValueTask<K,V,U>
5167	+	(map, null, -1, transformer, action);
5168	+	}
5169	+
5170	+	/**
5171	+	* Returns a task that when invoked, returns a non-null result
5172	+	* from applying the given search function on each value, or
5173	+	* null if none.  Upon success, further element processing is
5174	+	* suppressed and the results of any other parallel
5175	+	* invocations of the search function are ignored.
5176	+	*
5177	+	* @param map the map
5178	+	* @param searchFunction a function returning a non-null
5179	+	* result on success, else null
5180	+	* @return the task
5181	+	*/
5182	+	public static <K,V,U> ForkJoinTask<U> searchValues
5183	+	(ConcurrentHashMap<K,V> map,
5184	+	Function<? super V, ? extends U> searchFunction) {
5185	+	if (searchFunction == null) throw new NullPointerException();
5186	+	return new SearchValuesTask<K,V,U>
5187	+	(map, null, -1, searchFunction,
5188	+	new AtomicReference<U>());
5189	+	}
5190	+
5191	+	/**
5192	+	* Returns a task that when invoked, returns the result of
5193	+	* accumulating all values using the given reducer to combine
5194	+	* values, or null if none.
5195	+	*
5196	+	* @param map the map
5197	+	* @param reducer a commutative associative combining function
5198	+	* @return the task
5199	+	*/
5200	+	public static <K,V> ForkJoinTask<V> reduceValues
5201	+	(ConcurrentHashMap<K,V> map,
5202	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5203	+	if (reducer == null) throw new NullPointerException();
5204	+	return new ReduceValuesTask<K,V>
5205	+	(map, null, -1, null, reducer);
5206	+	}
5207	+
5208	+	/**
5209	+	* Returns a task that when invoked, returns the result of
5210	+	* accumulating the given transformation of all values using the
5211	+	* given reducer to combine values, or null if none.
5212	+	*
5213	+	* @param map the map
5214	+	* @param transformer a function returning the transformation
5215	+	* for an element, or null if there is no transformation (in
5216	+	* which case it is not combined)
5217	+	* @param reducer a commutative associative combining function
5218	+	* @return the task
5219	+	*/
5220	+	public static <K,V,U> ForkJoinTask<U> reduceValues
5221	+	(ConcurrentHashMap<K,V> map,
5222	+	Function<? super V, ? extends U> transformer,
5223	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5224	+	if (transformer == null || reducer == null)
5225	+	throw new NullPointerException();
5226	+	return new MapReduceValuesTask<K,V,U>
5227	+	(map, null, -1, null, transformer, reducer);
5228	+	}
5229	+
5230	+	/**
5231	+	* Returns a task that when invoked, returns the result of
5232	+	* accumulating the given transformation of all values using the
5233	+	* given reducer to combine values, and the given basis as an
5234	+	* identity value.
5235	+	*
5236	+	* @param map the map
5237	+	* @param transformer a function returning the transformation
5238	+	* for an element
5239	+	* @param basis the identity (initial default value) for the reduction
5240	+	* @param reducer a commutative associative combining function
5241	+	* @return the task
5242	+	*/
5243	+	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5244	+	(ConcurrentHashMap<K,V> map,
5245	+	ToDoubleFunction<? super V> transformer,
5246	+	double basis,
5247	+	DoubleBinaryOperator reducer) {
5248	+	if (transformer == null || reducer == null)
5249	+	throw new NullPointerException();
5250	+	return new MapReduceValuesToDoubleTask<K,V>
5251	+	(map, null, -1, null, transformer, basis, reducer);
5252	+	}
5253	+
5254	+	/**
5255	+	* Returns a task that when invoked, returns the result of
5256	+	* accumulating the given transformation of all values using the
5257	+	* given reducer to combine values, and the given basis as an
5258	+	* identity value.
5259	+	*
5260	+	* @param map the map
5261	+	* @param transformer a function returning the transformation
5262	+	* for an element
5263	+	* @param basis the identity (initial default value) for the reduction
5264	+	* @param reducer a commutative associative combining function
5265	+	* @return the task
5266	+	*/
5267	+	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5268	+	(ConcurrentHashMap<K,V> map,
5269	+	ToLongFunction<? super V> transformer,
5270	+	long basis,
5271	+	LongBinaryOperator reducer) {
5272	+	if (transformer == null || reducer == null)
5273	+	throw new NullPointerException();
5274	+	return new MapReduceValuesToLongTask<K,V>
5275	+	(map, null, -1, null, transformer, basis, reducer);
5276	+	}
5277	+
5278	+	/**
5279	+	* Returns a task that when invoked, returns the result of
5280	+	* accumulating the given transformation of all values using the
5281	+	* given reducer to combine values, and the given basis as an
5282	+	* identity value.
5283	+	*
5284	+	* @param map the map
5285	+	* @param transformer a function returning the transformation
5286	+	* for an element
5287	+	* @param basis the identity (initial default value) for the reduction
5288	+	* @param reducer a commutative associative combining function
5289	+	* @return the task
5290	+	*/
5291	+	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5292	+	(ConcurrentHashMap<K,V> map,
5293	+	ToIntFunction<? super V> transformer,
5294	+	int basis,
5295	+	IntBinaryOperator reducer) {
5296	+	if (transformer == null || reducer == null)
5297	+	throw new NullPointerException();
5298	+	return new MapReduceValuesToIntTask<K,V>
5299	+	(map, null, -1, null, transformer, basis, reducer);
5300	+	}
5301	+
5302	+	/**
5303	+	* Returns a task that when invoked, perform the given action
5304	+	* for each entry.
5305	+	*
5306	+	* @param map the map
5307	+	* @param action the action
5308	+	* @return the task
5309	+	*/
5310	+	public static <K,V> ForkJoinTask<Void> forEachEntry
5311	+	(ConcurrentHashMap<K,V> map,
5312	+	Consumer<? super Map.Entry<K,V>> action) {
5313	+	if (action == null) throw new NullPointerException();
5314	+	return new ForEachEntryTask<K,V>(map, null, -1, action);
5315	+	}
5316	+
5317	+	/**
5318	+	* Returns a task that when invoked, perform the given action
5319	+	* for each non-null transformation of each entry.
5320	+	*
5321	+	* @param map the map
5322	+	* @param transformer a function returning the transformation
5323	+	* for an element, or null if there is no transformation (in
5324	+	* which case the action is not applied)
5325	+	* @param action the action
5326	+	* @return the task
5327	+	*/
5328	+	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5329	+	(ConcurrentHashMap<K,V> map,
5330	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5331	+	Consumer<? super U> action) {
5332	+	if (transformer == null || action == null)
5333	+	throw new NullPointerException();
5334	+	return new ForEachTransformedEntryTask<K,V,U>
5335	+	(map, null, -1, transformer, action);
5336	+	}
5337	+
5338	+	/**
5339	+	* Returns a task that when invoked, returns a non-null result
5340	+	* from applying the given search function on each entry, or
5341	+	* null if none.  Upon success, further element processing is
5342	+	* suppressed and the results of any other parallel
5343	+	* invocations of the search function are ignored.
5344	+	*
5345	+	* @param map the map
5346	+	* @param searchFunction a function returning a non-null
5347	+	* result on success, else null
5348	+	* @return the task
5349	+	*/
5350	+	public static <K,V,U> ForkJoinTask<U> searchEntries
5351	+	(ConcurrentHashMap<K,V> map,
5352	+	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
5353	+	if (searchFunction == null) throw new NullPointerException();
5354	+	return new SearchEntriesTask<K,V,U>
5355	+	(map, null, -1, searchFunction,
5356	+	new AtomicReference<U>());
5357	+	}
5358	+
5359	+	/**
5360	+	* Returns a task that when invoked, returns the result of
5361	+	* accumulating all entries using the given reducer to combine
5362	+	* values, or null if none.
5363	+	*
5364	+	* @param map the map
5365	+	* @param reducer a commutative associative combining function
5366	+	* @return the task
5367	+	*/
5368	+	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5369	+	(ConcurrentHashMap<K,V> map,
5370	+	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5371	+	if (reducer == null) throw new NullPointerException();
5372	+	return new ReduceEntriesTask<K,V>
5373	+	(map, null, -1, null, reducer);
5374	+	}
5375	+
5376	+	/**
5377	+	* Returns a task that when invoked, returns the result of
5378	+	* accumulating the given transformation of all entries using the
5379	+	* given reducer to combine values, or null if none.
5380	+	*
5381	+	* @param map the map
5382	+	* @param transformer a function returning the transformation
5383	+	* for an element, or null if there is no transformation (in
5384	+	* which case it is not combined)
5385	+	* @param reducer a commutative associative combining function
5386	+	* @return the task
5387	+	*/
5388	+	public static <K,V,U> ForkJoinTask<U> reduceEntries
5389	+	(ConcurrentHashMap<K,V> map,
5390	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5391	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5392	+	if (transformer == null || reducer == null)
5393	+	throw new NullPointerException();
5394	+	return new MapReduceEntriesTask<K,V,U>
5395	+	(map, null, -1, null, transformer, reducer);
5396	+	}
5397	+
5398	+	/**
5399	+	* Returns a task that when invoked, returns the result of
5400	+	* accumulating the given transformation of all entries using the
5401	+	* given reducer to combine values, and the given basis as an
5402	+	* identity value.
5403	+	*
5404	+	* @param map the map
5405	+	* @param transformer a function returning the transformation
5406	+	* for an element
5407	+	* @param basis the identity (initial default value) for the reduction
5408	+	* @param reducer a commutative associative combining function
5409	+	* @return the task
5410	+	*/
5411	+	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5412	+	(ConcurrentHashMap<K,V> map,
5413	+	ToDoubleFunction<Map.Entry<K,V>> transformer,
5414	+	double basis,
5415	+	DoubleBinaryOperator reducer) {
5416	+	if (transformer == null || reducer == null)
5417	+	throw new NullPointerException();
5418	+	return new MapReduceEntriesToDoubleTask<K,V>
5419	+	(map, null, -1, null, transformer, basis, reducer);
5420	+	}
5421	+
5422	+	/**
5423	+	* Returns a task that when invoked, returns the result of
5424	+	* accumulating the given transformation of all entries using the
5425	+	* given reducer to combine values, and the given basis as an
5426	+	* identity value.
5427	+	*
5428	+	* @param map the map
5429	+	* @param transformer a function returning the transformation
5430	+	* for an element
5431	+	* @param basis the identity (initial default value) for the reduction
5432	+	* @param reducer a commutative associative combining function
5433	+	* @return the task
5434	+	*/
5435	+	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5436	+	(ConcurrentHashMap<K,V> map,
5437	+	ToLongFunction<Map.Entry<K,V>> transformer,
5438	+	long basis,
5439	+	LongBinaryOperator reducer) {
5440	+	if (transformer == null || reducer == null)
5441	+	throw new NullPointerException();
5442	+	return new MapReduceEntriesToLongTask<K,V>
5443	+	(map, null, -1, null, transformer, basis, reducer);
5444	+	}
5445	+
5446	+	/**
5447	+	* Returns a task that when invoked, returns the result of
5448	+	* accumulating the given transformation of all entries using the
5449	+	* given reducer to combine values, and the given basis as an
5450	+	* identity value.
5451	+	*
5452	+	* @param map the map
5453	+	* @param transformer a function returning the transformation
5454	+	* for an element
5455	+	* @param basis the identity (initial default value) for the reduction
5456	+	* @param reducer a commutative associative combining function
5457	+	* @return the task
5458	+	*/
5459	+	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5460	+	(ConcurrentHashMap<K,V> map,
5461	+	ToIntFunction<Map.Entry<K,V>> transformer,
5462	+	int basis,
5463	+	IntBinaryOperator reducer) {
5464	+	if (transformer == null || reducer == null)
5465	+	throw new NullPointerException();
5466	+	return new MapReduceEntriesToIntTask<K,V>
5467	+	(map, null, -1, null, transformer, basis, reducer);
5468	+	}
5469	+	}
5470	+
5471	+	// -------------------------------------------------------
5472	+
5473	+	/*
5474	+	* Task classes. Coded in a regular but ugly format/style to
5475	+	* simplify checks that each variant differs in the right way from
5476	+	* others. The null screenings exist because compilers cannot tell
5477	+	* that we've already null-checked task arguments, so we force
5478	+	* simplest hoisted bypass to help avoid convoluted traps.
5479	+	*/
5480	+
5481	+	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5482	+	extends Traverser<K,V,Void> {
5483	+	final Consumer<? super K> action;
5484	+	ForEachKeyTask
5485	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5486	+	Consumer<? super K> action) {
5487	+	super(m, p, b);
5488	+	this.action = action;
5489	+	}
5490	+	public final void compute() {
5491	+	final Consumer<? super K> action;
5492	+	if ((action = this.action) != null) {
5493	+	for (int b; (b = preSplit()) > 0;)
5494	+	new ForEachKeyTask<K,V>(map, this, b, action).fork();
5495	+	while (advance() != null)
5496	+	action.accept(nextKey);
5497	+	propagateCompletion();
5498	+	}
5499	+	}
5500	+	}
5501	+
5502	+	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5503	+	extends Traverser<K,V,Void> {
5504	+	final Consumer<? super V> action;
5505	+	ForEachValueTask
5506	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5507	+	Consumer<? super V> action) {
5508	+	super(m, p, b);
5509	+	this.action = action;
5510	+	}
5511	+	public final void compute() {
5512	+	final Consumer<? super V> action;
5513	+	if ((action = this.action) != null) {
5514	+	for (int b; (b = preSplit()) > 0;)
5515	+	new ForEachValueTask<K,V>(map, this, b, action).fork();
5516	+	V v;
5517	+	while ((v = advance()) != null)
5518	+	action.accept(v);
5519	+	propagateCompletion();
5520	+	}
5521	+	}
5522	+	}
5523	+
5524	+	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5525	+	extends Traverser<K,V,Void> {
5526	+	final Consumer<? super Entry<K,V>> action;
5527	+	ForEachEntryTask
5528	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5529	+	Consumer<? super Entry<K,V>> action) {
5530	+	super(m, p, b);
5531	+	this.action = action;
5532	+	}
5533	+	public final void compute() {
5534	+	final Consumer<? super Entry<K,V>> action;
5535	+	if ((action = this.action) != null) {
5536	+	for (int b; (b = preSplit()) > 0;)
5537	+	new ForEachEntryTask<K,V>(map, this, b, action).fork();
5538	+	V v;
5539	+	while ((v = advance()) != null)
5540	+	action.accept(entryFor(nextKey, v));
5541	+	propagateCompletion();
5542	+	}
5543	+	}
5544	+	}
5545	+
5546	+	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5547	+	extends Traverser<K,V,Void> {
5548	+	final BiConsumer<? super K, ? super V> action;
5549	+	ForEachMappingTask
5550	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5551	+	BiConsumer<? super K,? super V> action) {
5552	+	super(m, p, b);
5553	+	this.action = action;
5554	+	}
5555	+	public final void compute() {
5556	+	final BiConsumer<? super K, ? super V> action;
5557	+	if ((action = this.action) != null) {
5558	+	for (int b; (b = preSplit()) > 0;)
5559	+	new ForEachMappingTask<K,V>(map, this, b, action).fork();
5560	+	V v;
5561	+	while ((v = advance()) != null)
5562	+	action.accept(nextKey, v);
5563	+	propagateCompletion();
5564	+	}
5565	+	}
5566	+	}
5567	+
5568	+	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5569	+	extends Traverser<K,V,Void> {
5570	+	final Function<? super K, ? extends U> transformer;
5571	+	final Consumer<? super U> action;
5572	+	ForEachTransformedKeyTask
5573	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5574	+	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5575	+	super(m, p, b);
5576	+	this.transformer = transformer; this.action = action;
5577	+	}
5578	+	public final void compute() {
5579	+	final Function<? super K, ? extends U> transformer;
5580	+	final Consumer<? super U> action;
5581	+	if ((transformer = this.transformer) != null &&
5582	+	(action = this.action) != null) {
5583	+	for (int b; (b = preSplit()) > 0;)
5584	+	new ForEachTransformedKeyTask<K,V,U>
5585	+	(map, this, b, transformer, action).fork();
5586	+	U u;
5587	+	while (advance() != null) {
5588	+	if ((u = transformer.apply(nextKey)) != null)
5589	+	action.accept(u);
5590	+	}
5591	+	propagateCompletion();
5592	+	}
5593	+	}
5594	+	}
5595	+
5596	+	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5597	+	extends Traverser<K,V,Void> {
5598	+	final Function<? super V, ? extends U> transformer;
5599	+	final Consumer<? super U> action;
5600	+	ForEachTransformedValueTask
5601	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5602	+	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5603	+	super(m, p, b);
5604	+	this.transformer = transformer; this.action = action;
5605	+	}
5606	+	public final void compute() {
5607	+	final Function<? super V, ? extends U> transformer;
5608	+	final Consumer<? super U> action;
5609	+	if ((transformer = this.transformer) != null &&
5610	+	(action = this.action) != null) {
5611	+	for (int b; (b = preSplit()) > 0;)
5612	+	new ForEachTransformedValueTask<K,V,U>
5613	+	(map, this, b, transformer, action).fork();
5614	+	V v; U u;
5615	+	while ((v = advance()) != null) {
5616	+	if ((u = transformer.apply(v)) != null)
5617	+	action.accept(u);
5618	+	}
5619	+	propagateCompletion();
5620	+	}
5621	+	}
5622	+	}
5623	+
5624	+	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5625	+	extends Traverser<K,V,Void> {
5626	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5627	+	final Consumer<? super U> action;
5628	+	ForEachTransformedEntryTask
5629	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5630	+	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5631	+	super(m, p, b);
5632	+	this.transformer = transformer; this.action = action;
5633	+	}
5634	+	public final void compute() {
5635	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5636	+	final Consumer<? super U> action;
5637	+	if ((transformer = this.transformer) != null &&
5638	+	(action = this.action) != null) {
5639	+	for (int b; (b = preSplit()) > 0;)
5640	+	new ForEachTransformedEntryTask<K,V,U>
5641	+	(map, this, b, transformer, action).fork();
5642	+	V v; U u;
5643	+	while ((v = advance()) != null) {
5644	+	if ((u = transformer.apply(entryFor(nextKey,
5645	+	v))) != null)
5646	+	action.accept(u);
5647	+	}
5648	+	propagateCompletion();
5649	+	}
5650	+	}
5651	+	}
5652	+
5653	+	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5654	+	extends Traverser<K,V,Void> {
5655	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5656	+	final Consumer<? super U> action;
5657	+	ForEachTransformedMappingTask
5658	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5659	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5660	+	Consumer<? super U> action) {
5661	+	super(m, p, b);
5662	+	this.transformer = transformer; this.action = action;
5663	+	}
5664	+	public final void compute() {
5665	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5666	+	final Consumer<? super U> action;
5667	+	if ((transformer = this.transformer) != null &&
5668	+	(action = this.action) != null) {
5669	+	for (int b; (b = preSplit()) > 0;)
5670	+	new ForEachTransformedMappingTask<K,V,U>
5671	+	(map, this, b, transformer, action).fork();
5672	+	V v; U u;
5673	+	while ((v = advance()) != null) {
5674	+	if ((u = transformer.apply(nextKey, v)) != null)
5675	+	action.accept(u);
5676	+	}
5677	+	propagateCompletion();
5678	+	}
5679	+	}
5680	+	}
5681	+
5682	+	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5683	+	extends Traverser<K,V,U> {
5684	+	final Function<? super K, ? extends U> searchFunction;
5685	+	final AtomicReference<U> result;
5686	+	SearchKeysTask
5687	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5688	+	Function<? super K, ? extends U> searchFunction,
5689	+	AtomicReference<U> result) {
5690	+	super(m, p, b);
5691	+	this.searchFunction = searchFunction; this.result = result;
5692	+	}
5693	+	public final U getRawResult() { return result.get(); }
5694	+	public final void compute() {
5695	+	final Function<? super K, ? extends U> searchFunction;
5696	+	final AtomicReference<U> result;
5697	+	if ((searchFunction = this.searchFunction) != null &&
5698	+	(result = this.result) != null) {
5699	+	for (int b;;) {
5700	+	if (result.get() != null)
5701	+	return;
5702	+	if ((b = preSplit()) <= 0)
5703	+	break;
5704	+	new SearchKeysTask<K,V,U>
5705	+	(map, this, b, searchFunction, result).fork();
5706	+	}
5707	+	while (result.get() == null) {
5708	+	U u;
5709	+	if (advance() == null) {
5710	+	propagateCompletion();
5711	+	break;
5712	+	}
5713	+	if ((u = searchFunction.apply(nextKey)) != null) {
5714	+	if (result.compareAndSet(null, u))
5715	+	quietlyCompleteRoot();
5716	+	break;
5717	+	}
5718	+	}
5719	+	}
5720	+	}
5721	+	}
5722	+
5723	+	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5724	+	extends Traverser<K,V,U> {
5725	+	final Function<? super V, ? extends U> searchFunction;
5726	+	final AtomicReference<U> result;
5727	+	SearchValuesTask
5728	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5729	+	Function<? super V, ? extends U> searchFunction,
5730	+	AtomicReference<U> result) {
5731	+	super(m, p, b);
5732	+	this.searchFunction = searchFunction; this.result = result;
5733	+	}
5734	+	public final U getRawResult() { return result.get(); }
5735	+	public final void compute() {
5736	+	final Function<? super V, ? extends U> searchFunction;
5737	+	final AtomicReference<U> result;
5738	+	if ((searchFunction = this.searchFunction) != null &&
5739	+	(result = this.result) != null) {
5740	+	for (int b;;) {
5741	+	if (result.get() != null)
5742	+	return;
5743	+	if ((b = preSplit()) <= 0)
5744	+	break;
5745	+	new SearchValuesTask<K,V,U>
5746	+	(map, this, b, searchFunction, result).fork();
5747	+	}
5748	+	while (result.get() == null) {
5749	+	V v; U u;
5750	+	if ((v = advance()) == null) {
5751	+	propagateCompletion();
5752	+	break;
5753	+	}
5754	+	if ((u = searchFunction.apply(v)) != null) {
5755	+	if (result.compareAndSet(null, u))
5756	+	quietlyCompleteRoot();
5757	+	break;
5758	+	}
5759	+	}
5760	+	}
5761	+	}
5762	+	}
5763	+
5764	+	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5765	+	extends Traverser<K,V,U> {
5766	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5767	+	final AtomicReference<U> result;
5768	+	SearchEntriesTask
5769	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5770	+	Function<Entry<K,V>, ? extends U> searchFunction,
5771	+	AtomicReference<U> result) {
5772	+	super(m, p, b);
5773	+	this.searchFunction = searchFunction; this.result = result;
5774	+	}
5775	+	public final U getRawResult() { return result.get(); }
5776	+	public final void compute() {
5777	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5778	+	final AtomicReference<U> result;
5779	+	if ((searchFunction = this.searchFunction) != null &&
5780	+	(result = this.result) != null) {
5781	+	for (int b;;) {
5782	+	if (result.get() != null)
5783	+	return;
5784	+	if ((b = preSplit()) <= 0)
5785	+	break;
5786	+	new SearchEntriesTask<K,V,U>
5787	+	(map, this, b, searchFunction, result).fork();
5788	+	}
5789	+	while (result.get() == null) {
5790	+	V v; U u;
5791	+	if ((v = advance()) == null) {
5792	+	propagateCompletion();
5793	+	break;
5794	+	}
5795	+	if ((u = searchFunction.apply(entryFor(nextKey,
5796	+	v))) != null) {
5797	+	if (result.compareAndSet(null, u))
5798	+	quietlyCompleteRoot();
5799	+	return;
5800	+	}
5801	+	}
5802	+	}
5803	+	}
5804	+	}
5805	+
5806	+	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5807	+	extends Traverser<K,V,U> {
5808	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5809	+	final AtomicReference<U> result;
5810	+	SearchMappingsTask
5811	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5812	+	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5813	+	AtomicReference<U> result) {
5814	+	super(m, p, b);
5815	+	this.searchFunction = searchFunction; this.result = result;
5816	+	}
5817	+	public final U getRawResult() { return result.get(); }
5818	+	public final void compute() {
5819	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5820	+	final AtomicReference<U> result;
5821	+	if ((searchFunction = this.searchFunction) != null &&
5822	+	(result = this.result) != null) {
5823	+	for (int b;;) {
5824	+	if (result.get() != null)
5825	+	return;
5826	+	if ((b = preSplit()) <= 0)
5827	+	break;
5828	+	new SearchMappingsTask<K,V,U>
5829	+	(map, this, b, searchFunction, result).fork();
5830	+	}
5831	+	while (result.get() == null) {
5832	+	V v; U u;
5833	+	if ((v = advance()) == null) {
5834	+	propagateCompletion();
5835	+	break;
5836	+	}
5837	+	if ((u = searchFunction.apply(nextKey, v)) != null) {
5838	+	if (result.compareAndSet(null, u))
5839	+	quietlyCompleteRoot();
5840	+	break;
5841	+	}
5842	+	}
5843	+	}
5844	+	}
5845	+	}
5846	+
5847	+	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5848	+	extends Traverser<K,V,K> {
5849	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5850	+	K result;
5851	+	ReduceKeysTask<K,V> rights, nextRight;
5852	+	ReduceKeysTask
5853	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5854	+	ReduceKeysTask<K,V> nextRight,
5855	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5856	+	super(m, p, b); this.nextRight = nextRight;
5857	+	this.reducer = reducer;
5858	+	}
5859	+	public final K getRawResult() { return result; }
5860	+	@SuppressWarnings("unchecked") public final void compute() {
5861	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5862	+	if ((reducer = this.reducer) != null) {
5863	+	for (int b; (b = preSplit()) > 0;)
5864	+	(rights = new ReduceKeysTask<K,V>
5865	+	(map, this, b, rights, reducer)).fork();
5866	+	K r = null;
5867	+	while (advance() != null) {
5868	+	K u = nextKey;
5869	+	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5870	+	}
5871	+	result = r;
5872	+	CountedCompleter<?> c;
5873	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5874	+	ReduceKeysTask<K,V>
5875	+	t = (ReduceKeysTask<K,V>)c,
5876	+	s = t.rights;
5877	+	while (s != null) {
5878	+	K tr, sr;
5879	+	if ((sr = s.result) != null)
5880	+	t.result = (((tr = t.result) == null) ? sr :
5881	+	reducer.apply(tr, sr));
5882	+	s = t.rights = s.nextRight;
5883	+	}
5884	+	}
5885	+	}
5886	+	}
5887	+	}
5888	+
5889	+	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
5890	+	extends Traverser<K,V,V> {
5891	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5892	+	V result;
5893	+	ReduceValuesTask<K,V> rights, nextRight;
5894	+	ReduceValuesTask
5895	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5896	+	ReduceValuesTask<K,V> nextRight,
5897	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5898	+	super(m, p, b); this.nextRight = nextRight;
5899	+	this.reducer = reducer;
5900	+	}
5901	+	public final V getRawResult() { return result; }
5902	+	@SuppressWarnings("unchecked") public final void compute() {
5903	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5904	+	if ((reducer = this.reducer) != null) {
5905	+	for (int b; (b = preSplit()) > 0;)
5906	+	(rights = new ReduceValuesTask<K,V>
5907	+	(map, this, b, rights, reducer)).fork();
5908	+	V r = null, v;
5909	+	while ((v = advance()) != null)
5910	+	r = (r == null) ? v : reducer.apply(r, v);
5911	+	result = r;
5912	+	CountedCompleter<?> c;
5913	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5914	+	ReduceValuesTask<K,V>
5915	+	t = (ReduceValuesTask<K,V>)c,
5916	+	s = t.rights;
5917	+	while (s != null) {
5918	+	V tr, sr;
5919	+	if ((sr = s.result) != null)
5920	+	t.result = (((tr = t.result) == null) ? sr :
5921	+	reducer.apply(tr, sr));
5922	+	s = t.rights = s.nextRight;
5923	+	}
5924	+	}
5925	+	}
5926	+	}
5927	+	}
5928	+
5929	+	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
5930	+	extends Traverser<K,V,Map.Entry<K,V>> {
5931	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5932	+	Map.Entry<K,V> result;
5933	+	ReduceEntriesTask<K,V> rights, nextRight;
5934	+	ReduceEntriesTask
5935	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5936	+	ReduceEntriesTask<K,V> nextRight,
5937	+	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5938	+	super(m, p, b); this.nextRight = nextRight;
5939	+	this.reducer = reducer;
5940	+	}
5941	+	public final Map.Entry<K,V> getRawResult() { return result; }
5942	+	@SuppressWarnings("unchecked") public final void compute() {
5943	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5944	+	if ((reducer = this.reducer) != null) {
5945	+	for (int b; (b = preSplit()) > 0;)
5946	+	(rights = new ReduceEntriesTask<K,V>
5947	+	(map, this, b, rights, reducer)).fork();
5948	+	Map.Entry<K,V> r = null;
5949	+	V v;
5950	+	while ((v = advance()) != null) {
5951	+	Map.Entry<K,V> u = entryFor(nextKey, v);
5952	+	r = (r == null) ? u : reducer.apply(r, u);
5953	+	}
5954	+	result = r;
5955	+	CountedCompleter<?> c;
5956	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5957	+	ReduceEntriesTask<K,V>
5958	+	t = (ReduceEntriesTask<K,V>)c,
5959	+	s = t.rights;
5960	+	while (s != null) {
5961	+	Map.Entry<K,V> tr, sr;
5962	+	if ((sr = s.result) != null)
5963	+	t.result = (((tr = t.result) == null) ? sr :
5964	+	reducer.apply(tr, sr));
5965	+	s = t.rights = s.nextRight;
5966	+	}
5967	+	}
5968	+	}
5969	+	}
5970	+	}
5971	+
5972	+	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
5973	+	extends Traverser<K,V,U> {
5974	+	final Function<? super K, ? extends U> transformer;
5975	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5976	+	U result;
5977	+	MapReduceKeysTask<K,V,U> rights, nextRight;
5978	+	MapReduceKeysTask
5979	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5980	+	MapReduceKeysTask<K,V,U> nextRight,
5981	+	Function<? super K, ? extends U> transformer,
5982	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5983	+	super(m, p, b); this.nextRight = nextRight;
5984	+	this.transformer = transformer;
5985	+	this.reducer = reducer;
5986	+	}
5987	+	public final U getRawResult() { return result; }
5988	+	@SuppressWarnings("unchecked") public final void compute() {
5989	+	final Function<? super K, ? extends U> transformer;
5990	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5991	+	if ((transformer = this.transformer) != null &&
5992	+	(reducer = this.reducer) != null) {
5993	+	for (int b; (b = preSplit()) > 0;)
5994	+	(rights = new MapReduceKeysTask<K,V,U>
5995	+	(map, this, b, rights, transformer, reducer)).fork();
5996	+	U r = null, u;
5997	+	while (advance() != null) {
5998	+	if ((u = transformer.apply(nextKey)) != null)
5999	+	r = (r == null) ? u : reducer.apply(r, u);
6000	+	}
6001	+	result = r;
6002	+	CountedCompleter<?> c;
6003	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6004	+	MapReduceKeysTask<K,V,U>
6005	+	t = (MapReduceKeysTask<K,V,U>)c,
6006	+	s = t.rights;
6007	+	while (s != null) {
6008	+	U tr, sr;
6009	+	if ((sr = s.result) != null)
6010	+	t.result = (((tr = t.result) == null) ? sr :
6011	+	reducer.apply(tr, sr));
6012	+	s = t.rights = s.nextRight;
6013	+	}
6014	+	}
6015	+	}
6016	+	}
6017	+	}
6018	+
6019	+	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
6020	+	extends Traverser<K,V,U> {
6021	+	final Function<? super V, ? extends U> transformer;
6022	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6023	+	U result;
6024	+	MapReduceValuesTask<K,V,U> rights, nextRight;
6025	+	MapReduceValuesTask
6026	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6027	+	MapReduceValuesTask<K,V,U> nextRight,
6028	+	Function<? super V, ? extends U> transformer,
6029	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6030	+	super(m, p, b); this.nextRight = nextRight;
6031	+	this.transformer = transformer;
6032	+	this.reducer = reducer;
6033	+	}
6034	+	public final U getRawResult() { return result; }
6035	+	@SuppressWarnings("unchecked") public final void compute() {
6036	+	final Function<? super V, ? extends U> transformer;
6037	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6038	+	if ((transformer = this.transformer) != null &&
6039	+	(reducer = this.reducer) != null) {
6040	+	for (int b; (b = preSplit()) > 0;)
6041	+	(rights = new MapReduceValuesTask<K,V,U>
6042	+	(map, this, b, rights, transformer, reducer)).fork();
6043	+	U r = null, u;
6044	+	V v;
6045	+	while ((v = advance()) != null) {
6046	+	if ((u = transformer.apply(v)) != null)
6047	+	r = (r == null) ? u : reducer.apply(r, u);
6048	+	}
6049	+	result = r;
6050	+	CountedCompleter<?> c;
6051	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6052	+	MapReduceValuesTask<K,V,U>
6053	+	t = (MapReduceValuesTask<K,V,U>)c,
6054	+	s = t.rights;
6055	+	while (s != null) {
6056	+	U tr, sr;
6057	+	if ((sr = s.result) != null)
6058	+	t.result = (((tr = t.result) == null) ? sr :
6059	+	reducer.apply(tr, sr));
6060	+	s = t.rights = s.nextRight;
6061	+	}
6062	+	}
6063	+	}
6064	+	}
6065	+	}
6066	+
6067	+	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
6068	+	extends Traverser<K,V,U> {
6069	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
6070	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6071	+	U result;
6072	+	MapReduceEntriesTask<K,V,U> rights, nextRight;
6073	+	MapReduceEntriesTask
6074	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6075	+	MapReduceEntriesTask<K,V,U> nextRight,
6076	+	Function<Map.Entry<K,V>, ? extends U> transformer,
6077	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6078	+	super(m, p, b); this.nextRight = nextRight;
6079	+	this.transformer = transformer;
6080	+	this.reducer = reducer;
6081	+	}
6082	+	public final U getRawResult() { return result; }
6083	+	@SuppressWarnings("unchecked") public final void compute() {
6084	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
6085	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6086	+	if ((transformer = this.transformer) != null &&
6087	+	(reducer = this.reducer) != null) {
6088	+	for (int b; (b = preSplit()) > 0;)
6089	+	(rights = new MapReduceEntriesTask<K,V,U>
6090	+	(map, this, b, rights, transformer, reducer)).fork();
6091	+	U r = null, u;
6092	+	V v;
6093	+	while ((v = advance()) != null) {
6094	+	if ((u = transformer.apply(entryFor(nextKey,
6095	+	v))) != null)
6096	+	r = (r == null) ? u : reducer.apply(r, u);
6097	+	}
6098	+	result = r;
6099	+	CountedCompleter<?> c;
6100	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6101	+	MapReduceEntriesTask<K,V,U>
6102	+	t = (MapReduceEntriesTask<K,V,U>)c,
6103	+	s = t.rights;
6104	+	while (s != null) {
6105	+	U tr, sr;
6106	+	if ((sr = s.result) != null)
6107	+	t.result = (((tr = t.result) == null) ? sr :
6108	+	reducer.apply(tr, sr));
6109	+	s = t.rights = s.nextRight;
6110	+	}
6111	+	}
6112	+	}
6113	+	}
6114	+	}
6115	+
6116	+	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6117	+	extends Traverser<K,V,U> {
6118	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
6119	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6120	+	U result;
6121	+	MapReduceMappingsTask<K,V,U> rights, nextRight;
6122	+	MapReduceMappingsTask
6123	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6124	+	MapReduceMappingsTask<K,V,U> nextRight,
6125	+	BiFunction<? super K, ? super V, ? extends U> transformer,
6126	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6127	+	super(m, p, b); this.nextRight = nextRight;
6128	+	this.transformer = transformer;
6129	+	this.reducer = reducer;
6130	+	}
6131	+	public final U getRawResult() { return result; }
6132	+	@SuppressWarnings("unchecked") public final void compute() {
6133	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
6134	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6135	+	if ((transformer = this.transformer) != null &&
6136	+	(reducer = this.reducer) != null) {
6137	+	for (int b; (b = preSplit()) > 0;)
6138	+	(rights = new MapReduceMappingsTask<K,V,U>
6139	+	(map, this, b, rights, transformer, reducer)).fork();
6140	+	U r = null, u;
6141	+	V v;
6142	+	while ((v = advance()) != null) {
6143	+	if ((u = transformer.apply(nextKey, v)) != null)
6144	+	r = (r == null) ? u : reducer.apply(r, u);
6145	+	}
6146	+	result = r;
6147	+	CountedCompleter<?> c;
6148	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6149	+	MapReduceMappingsTask<K,V,U>
6150	+	t = (MapReduceMappingsTask<K,V,U>)c,
6151	+	s = t.rights;
6152	+	while (s != null) {
6153	+	U tr, sr;
6154	+	if ((sr = s.result) != null)
6155	+	t.result = (((tr = t.result) == null) ? sr :
6156	+	reducer.apply(tr, sr));
6157	+	s = t.rights = s.nextRight;
6158	+	}
6159	+	}
6160	+	}
6161	+	}
6162	+	}
6163	+
6164	+	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6165	+	extends Traverser<K,V,Double> {
6166	+	final ToDoubleFunction<? super K> transformer;
6167	+	final DoubleBinaryOperator reducer;
6168	+	final double basis;
6169	+	double result;
6170	+	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6171	+	MapReduceKeysToDoubleTask
6172	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6173	+	MapReduceKeysToDoubleTask<K,V> nextRight,
6174	+	ToDoubleFunction<? super K> transformer,
6175	+	double basis,
6176	+	DoubleBinaryOperator reducer) {
6177	+	super(m, p, b); this.nextRight = nextRight;
6178	+	this.transformer = transformer;
6179	+	this.basis = basis; this.reducer = reducer;
6180	+	}
6181	+	public final Double getRawResult() { return result; }
6182	+	@SuppressWarnings("unchecked") public final void compute() {
6183	+	final ToDoubleFunction<? super K> transformer;
6184	+	final DoubleBinaryOperator reducer;
6185	+	if ((transformer = this.transformer) != null &&
6186	+	(reducer = this.reducer) != null) {
6187	+	double r = this.basis;
6188	+	for (int b; (b = preSplit()) > 0;)
6189	+	(rights = new MapReduceKeysToDoubleTask<K,V>
6190	+	(map, this, b, rights, transformer, r, reducer)).fork();
6191	+	while (advance() != null)
6192	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(nextKey));
6193	+	result = r;
6194	+	CountedCompleter<?> c;
6195	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6196	+	MapReduceKeysToDoubleTask<K,V>
6197	+	t = (MapReduceKeysToDoubleTask<K,V>)c,
6198	+	s = t.rights;
6199	+	while (s != null) {
6200	+	t.result = reducer.applyAsDouble(t.result, s.result);
6201	+	s = t.rights = s.nextRight;
6202	+	}
6203	+	}
6204	+	}
6205	+	}
6206	+	}
6207	+
6208	+	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6209	+	extends Traverser<K,V,Double> {
6210	+	final ToDoubleFunction<? super V> transformer;
6211	+	final DoubleBinaryOperator reducer;
6212	+	final double basis;
6213	+	double result;
6214	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6215	+	MapReduceValuesToDoubleTask
6216	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6217	+	MapReduceValuesToDoubleTask<K,V> nextRight,
6218	+	ToDoubleFunction<? super V> transformer,
6219	+	double basis,
6220	+	DoubleBinaryOperator reducer) {
6221	+	super(m, p, b); this.nextRight = nextRight;
6222	+	this.transformer = transformer;
6223	+	this.basis = basis; this.reducer = reducer;
6224	+	}
6225	+	public final Double getRawResult() { return result; }
6226	+	@SuppressWarnings("unchecked") public final void compute() {
6227	+	final ToDoubleFunction<? super V> transformer;
6228	+	final DoubleBinaryOperator reducer;
6229	+	if ((transformer = this.transformer) != null &&
6230	+	(reducer = this.reducer) != null) {
6231	+	double r = this.basis;
6232	+	for (int b; (b = preSplit()) > 0;)
6233	+	(rights = new MapReduceValuesToDoubleTask<K,V>
6234	+	(map, this, b, rights, transformer, r, reducer)).fork();
6235	+	V v;
6236	+	while ((v = advance()) != null)
6237	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
6238	+	result = r;
6239	+	CountedCompleter<?> c;
6240	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6241	+	MapReduceValuesToDoubleTask<K,V>
6242	+	t = (MapReduceValuesToDoubleTask<K,V>)c,
6243	+	s = t.rights;
6244	+	while (s != null) {
6245	+	t.result = reducer.applyAsDouble(t.result, s.result);
6246	+	s = t.rights = s.nextRight;
6247	+	}
6248	+	}
6249	+	}
6250	+	}
6251	+	}
6252	+
6253	+	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6254	+	extends Traverser<K,V,Double> {
6255	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6256	+	final DoubleBinaryOperator reducer;
6257	+	final double basis;
6258	+	double result;
6259	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6260	+	MapReduceEntriesToDoubleTask
6261	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6262	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
6263	+	ToDoubleFunction<Map.Entry<K,V>> transformer,
6264	+	double basis,
6265	+	DoubleBinaryOperator reducer) {
6266	+	super(m, p, b); this.nextRight = nextRight;
6267	+	this.transformer = transformer;
6268	+	this.basis = basis; this.reducer = reducer;
6269	+	}
6270	+	public final Double getRawResult() { return result; }
6271	+	@SuppressWarnings("unchecked") public final void compute() {
6272	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6273	+	final DoubleBinaryOperator reducer;
6274	+	if ((transformer = this.transformer) != null &&
6275	+	(reducer = this.reducer) != null) {
6276	+	double r = this.basis;
6277	+	for (int b; (b = preSplit()) > 0;)
6278	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
6279	+	(map, this, b, rights, transformer, r, reducer)).fork();
6280	+	V v;
6281	+	while ((v = advance()) != null)
6282	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(nextKey,
6283	+	v)));
6284	+	result = r;
6285	+	CountedCompleter<?> c;
6286	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6287	+	MapReduceEntriesToDoubleTask<K,V>
6288	+	t = (MapReduceEntriesToDoubleTask<K,V>)c,
6289	+	s = t.rights;
6290	+	while (s != null) {
6291	+	t.result = reducer.applyAsDouble(t.result, s.result);
6292	+	s = t.rights = s.nextRight;
6293	+	}
6294	+	}
6295	+	}
6296	+	}
6297	+	}
6298	+
6299	+	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6300	+	extends Traverser<K,V,Double> {
6301	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
6302	+	final DoubleBinaryOperator reducer;
6303	+	final double basis;
6304	+	double result;
6305	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6306	+	MapReduceMappingsToDoubleTask
6307	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6308	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
6309	+	ToDoubleBiFunction<? super K, ? super V> transformer,
6310	+	double basis,
6311	+	DoubleBinaryOperator reducer) {
6312	+	super(m, p, b); this.nextRight = nextRight;
6313	+	this.transformer = transformer;
6314	+	this.basis = basis; this.reducer = reducer;
6315	+	}
6316	+	public final Double getRawResult() { return result; }
6317	+	@SuppressWarnings("unchecked") public final void compute() {
6318	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
6319	+	final DoubleBinaryOperator reducer;
6320	+	if ((transformer = this.transformer) != null &&
6321	+	(reducer = this.reducer) != null) {
6322	+	double r = this.basis;
6323	+	for (int b; (b = preSplit()) > 0;)
6324	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
6325	+	(map, this, b, rights, transformer, r, reducer)).fork();
6326	+	V v;
6327	+	while ((v = advance()) != null)
6328	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(nextKey, v));
6329	+	result = r;
6330	+	CountedCompleter<?> c;
6331	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6332	+	MapReduceMappingsToDoubleTask<K,V>
6333	+	t = (MapReduceMappingsToDoubleTask<K,V>)c,
6334	+	s = t.rights;
6335	+	while (s != null) {
6336	+	t.result = reducer.applyAsDouble(t.result, s.result);
6337	+	s = t.rights = s.nextRight;
6338	+	}
6339	+	}
6340	+	}
6341	+	}
6342	+	}
6343	+
6344	+	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6345	+	extends Traverser<K,V,Long> {
6346	+	final ToLongFunction<? super K> transformer;
6347	+	final LongBinaryOperator reducer;
6348	+	final long basis;
6349	+	long result;
6350	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
6351	+	MapReduceKeysToLongTask
6352	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6353	+	MapReduceKeysToLongTask<K,V> nextRight,
6354	+	ToLongFunction<? super K> transformer,
6355	+	long basis,
6356	+	LongBinaryOperator reducer) {
6357	+	super(m, p, b); this.nextRight = nextRight;
6358	+	this.transformer = transformer;
6359	+	this.basis = basis; this.reducer = reducer;
6360	+	}
6361	+	public final Long getRawResult() { return result; }
6362	+	@SuppressWarnings("unchecked") public final void compute() {
6363	+	final ToLongFunction<? super K> transformer;
6364	+	final LongBinaryOperator reducer;
6365	+	if ((transformer = this.transformer) != null &&
6366	+	(reducer = this.reducer) != null) {
6367	+	long r = this.basis;
6368	+	for (int b; (b = preSplit()) > 0;)
6369	+	(rights = new MapReduceKeysToLongTask<K,V>
6370	+	(map, this, b, rights, transformer, r, reducer)).fork();
6371	+	while (advance() != null)
6372	+	r = reducer.applyAsLong(r, transformer.applyAsLong(nextKey));
6373	+	result = r;
6374	+	CountedCompleter<?> c;
6375	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6376	+	MapReduceKeysToLongTask<K,V>
6377	+	t = (MapReduceKeysToLongTask<K,V>)c,
6378	+	s = t.rights;
6379	+	while (s != null) {
6380	+	t.result = reducer.applyAsLong(t.result, s.result);
6381	+	s = t.rights = s.nextRight;
6382	+	}
6383	+	}
6384	+	}
6385	+	}
6386	+	}
6387	+
6388	+	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6389	+	extends Traverser<K,V,Long> {
6390	+	final ToLongFunction<? super V> transformer;
6391	+	final LongBinaryOperator reducer;
6392	+	final long basis;
6393	+	long result;
6394	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
6395	+	MapReduceValuesToLongTask
6396	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6397	+	MapReduceValuesToLongTask<K,V> nextRight,
6398	+	ToLongFunction<? super V> transformer,
6399	+	long basis,
6400	+	LongBinaryOperator reducer) {
6401	+	super(m, p, b); this.nextRight = nextRight;
6402	+	this.transformer = transformer;
6403	+	this.basis = basis; this.reducer = reducer;
6404	+	}
6405	+	public final Long getRawResult() { return result; }
6406	+	@SuppressWarnings("unchecked") public final void compute() {
6407	+	final ToLongFunction<? super V> transformer;
6408	+	final LongBinaryOperator reducer;
6409	+	if ((transformer = this.transformer) != null &&
6410	+	(reducer = this.reducer) != null) {
6411	+	long r = this.basis;
6412	+	for (int b; (b = preSplit()) > 0;)
6413	+	(rights = new MapReduceValuesToLongTask<K,V>
6414	+	(map, this, b, rights, transformer, r, reducer)).fork();
6415	+	V v;
6416	+	while ((v = advance()) != null)
6417	+	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
6418	+	result = r;
6419	+	CountedCompleter<?> c;
6420	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6421	+	MapReduceValuesToLongTask<K,V>
6422	+	t = (MapReduceValuesToLongTask<K,V>)c,
6423	+	s = t.rights;
6424	+	while (s != null) {
6425	+	t.result = reducer.applyAsLong(t.result, s.result);
6426	+	s = t.rights = s.nextRight;
6427	+	}
6428	+	}
6429	+	}
6430	+	}
6431	+	}
6432	+
6433	+	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6434	+	extends Traverser<K,V,Long> {
6435	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6436	+	final LongBinaryOperator reducer;
6437	+	final long basis;
6438	+	long result;
6439	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6440	+	MapReduceEntriesToLongTask
6441	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6442	+	MapReduceEntriesToLongTask<K,V> nextRight,
6443	+	ToLongFunction<Map.Entry<K,V>> transformer,
6444	+	long basis,
6445	+	LongBinaryOperator reducer) {
6446	+	super(m, p, b); this.nextRight = nextRight;
6447	+	this.transformer = transformer;
6448	+	this.basis = basis; this.reducer = reducer;
6449	+	}
6450	+	public final Long getRawResult() { return result; }
6451	+	@SuppressWarnings("unchecked") public final void compute() {
6452	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6453	+	final LongBinaryOperator reducer;
6454	+	if ((transformer = this.transformer) != null &&
6455	+	(reducer = this.reducer) != null) {
6456	+	long r = this.basis;
6457	+	for (int b; (b = preSplit()) > 0;)
6458	+	(rights = new MapReduceEntriesToLongTask<K,V>
6459	+	(map, this, b, rights, transformer, r, reducer)).fork();
6460	+	V v;
6461	+	while ((v = advance()) != null)
6462	+	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(nextKey, v)));
6463	+	result = r;
6464	+	CountedCompleter<?> c;
6465	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6466	+	MapReduceEntriesToLongTask<K,V>
6467	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6468	+	s = t.rights;
6469	+	while (s != null) {
6470	+	t.result = reducer.applyAsLong(t.result, s.result);
6471	+	s = t.rights = s.nextRight;
6472	+	}
6473	+	}
6474	+	}
6475	+	}
6476	+	}
6477	+
6478	+	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6479	+	extends Traverser<K,V,Long> {
6480	+	final ToLongBiFunction<? super K, ? super V> transformer;
6481	+	final LongBinaryOperator reducer;
6482	+	final long basis;
6483	+	long result;
6484	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6485	+	MapReduceMappingsToLongTask
6486	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6487	+	MapReduceMappingsToLongTask<K,V> nextRight,
6488	+	ToLongBiFunction<? super K, ? super V> transformer,
6489	+	long basis,
6490	+	LongBinaryOperator reducer) {
6491	+	super(m, p, b); this.nextRight = nextRight;
6492	+	this.transformer = transformer;
6493	+	this.basis = basis; this.reducer = reducer;
6494	+	}
6495	+	public final Long getRawResult() { return result; }
6496	+	@SuppressWarnings("unchecked") public final void compute() {
6497	+	final ToLongBiFunction<? super K, ? super V> transformer;
6498	+	final LongBinaryOperator reducer;
6499	+	if ((transformer = this.transformer) != null &&
6500	+	(reducer = this.reducer) != null) {
6501	+	long r = this.basis;
6502	+	for (int b; (b = preSplit()) > 0;)
6503	+	(rights = new MapReduceMappingsToLongTask<K,V>
6504	+	(map, this, b, rights, transformer, r, reducer)).fork();
6505	+	V v;
6506	+	while ((v = advance()) != null)
6507	+	r = reducer.applyAsLong(r, transformer.applyAsLong(nextKey, v));
6508	+	result = r;
6509	+	CountedCompleter<?> c;
6510	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6511	+	MapReduceMappingsToLongTask<K,V>
6512	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6513	+	s = t.rights;
6514	+	while (s != null) {
6515	+	t.result = reducer.applyAsLong(t.result, s.result);
6516	+	s = t.rights = s.nextRight;
6517	+	}
6518	+	}
6519	+	}
6520	+	}
6521	+	}
6522	+
6523	+	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6524	+	extends Traverser<K,V,Integer> {
6525	+	final ToIntFunction<? super K> transformer;
6526	+	final IntBinaryOperator reducer;
6527	+	final int basis;
6528	+	int result;
6529	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6530	+	MapReduceKeysToIntTask
6531	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6532	+	MapReduceKeysToIntTask<K,V> nextRight,
6533	+	ToIntFunction<? super K> transformer,
6534	+	int basis,
6535	+	IntBinaryOperator reducer) {
6536	+	super(m, p, b); this.nextRight = nextRight;
6537	+	this.transformer = transformer;
6538	+	this.basis = basis; this.reducer = reducer;
6539	+	}
6540	+	public final Integer getRawResult() { return result; }
6541	+	@SuppressWarnings("unchecked") public final void compute() {
6542	+	final ToIntFunction<? super K> transformer;
6543	+	final IntBinaryOperator reducer;
6544	+	if ((transformer = this.transformer) != null &&
6545	+	(reducer = this.reducer) != null) {
6546	+	int r = this.basis;
6547	+	for (int b; (b = preSplit()) > 0;)
6548	+	(rights = new MapReduceKeysToIntTask<K,V>
6549	+	(map, this, b, rights, transformer, r, reducer)).fork();
6550	+	while (advance() != null)
6551	+	r = reducer.applyAsInt(r, transformer.applyAsInt(nextKey));
6552	+	result = r;
6553	+	CountedCompleter<?> c;
6554	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6555	+	MapReduceKeysToIntTask<K,V>
6556	+	t = (MapReduceKeysToIntTask<K,V>)c,
6557	+	s = t.rights;
6558	+	while (s != null) {
6559	+	t.result = reducer.applyAsInt(t.result, s.result);
6560	+	s = t.rights = s.nextRight;
6561	+	}
6562	+	}
6563	+	}
6564	+	}
6565	+	}
6566	+
6567	+	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6568	+	extends Traverser<K,V,Integer> {
6569	+	final ToIntFunction<? super V> transformer;
6570	+	final IntBinaryOperator reducer;
6571	+	final int basis;
6572	+	int result;
6573	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6574	+	MapReduceValuesToIntTask
6575	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6576	+	MapReduceValuesToIntTask<K,V> nextRight,
6577	+	ToIntFunction<? super V> transformer,
6578	+	int basis,
6579	+	IntBinaryOperator reducer) {
6580	+	super(m, p, b); this.nextRight = nextRight;
6581	+	this.transformer = transformer;
6582	+	this.basis = basis; this.reducer = reducer;
6583	+	}
6584	+	public final Integer getRawResult() { return result; }
6585	+	@SuppressWarnings("unchecked") public final void compute() {
6586	+	final ToIntFunction<? super V> transformer;
6587	+	final IntBinaryOperator reducer;
6588	+	if ((transformer = this.transformer) != null &&
6589	+	(reducer = this.reducer) != null) {
6590	+	int r = this.basis;
6591	+	for (int b; (b = preSplit()) > 0;)
6592	+	(rights = new MapReduceValuesToIntTask<K,V>
6593	+	(map, this, b, rights, transformer, r, reducer)).fork();
6594	+	V v;
6595	+	while ((v = advance()) != null)
6596	+	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
6597	+	result = r;
6598	+	CountedCompleter<?> c;
6599	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6600	+	MapReduceValuesToIntTask<K,V>
6601	+	t = (MapReduceValuesToIntTask<K,V>)c,
6602	+	s = t.rights;
6603	+	while (s != null) {
6604	+	t.result = reducer.applyAsInt(t.result, s.result);
6605	+	s = t.rights = s.nextRight;
6606	+	}
6607	+	}
6608	+	}
6609	+	}
6610	+	}
6611	+
6612	+	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6613	+	extends Traverser<K,V,Integer> {
6614	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6615	+	final IntBinaryOperator reducer;
6616	+	final int basis;
6617	+	int result;
6618	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6619	+	MapReduceEntriesToIntTask
6620	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6621	+	MapReduceEntriesToIntTask<K,V> nextRight,
6622	+	ToIntFunction<Map.Entry<K,V>> transformer,
6623	+	int basis,
6624	+	IntBinaryOperator reducer) {
6625	+	super(m, p, b); this.nextRight = nextRight;
6626	+	this.transformer = transformer;
6627	+	this.basis = basis; this.reducer = reducer;
6628	+	}
6629	+	public final Integer getRawResult() { return result; }
6630	+	@SuppressWarnings("unchecked") public final void compute() {
6631	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6632	+	final IntBinaryOperator reducer;
6633	+	if ((transformer = this.transformer) != null &&
6634	+	(reducer = this.reducer) != null) {
6635	+	int r = this.basis;
6636	+	for (int b; (b = preSplit()) > 0;)
6637	+	(rights = new MapReduceEntriesToIntTask<K,V>
6638	+	(map, this, b, rights, transformer, r, reducer)).fork();
6639	+	V v;
6640	+	while ((v = advance()) != null)
6641	+	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(nextKey,
6642	+	v)));
6643	+	result = r;
6644	+	CountedCompleter<?> c;
6645	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6646	+	MapReduceEntriesToIntTask<K,V>
6647	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6648	+	s = t.rights;
6649	+	while (s != null) {
6650	+	t.result = reducer.applyAsInt(t.result, s.result);
6651	+	s = t.rights = s.nextRight;
6652	+	}
6653	+	}
6654	+	}
6655	+	}
6656	+	}
6657	+
6658	+	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6659	+	extends Traverser<K,V,Integer> {
6660	+	final ToIntBiFunction<? super K, ? super V> transformer;
6661	+	final IntBinaryOperator reducer;
6662	+	final int basis;
6663	+	int result;
6664	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6665	+	MapReduceMappingsToIntTask
6666	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6667	+	MapReduceMappingsToIntTask<K,V> nextRight,
6668	+	ToIntBiFunction<? super K, ? super V> transformer,
6669	+	int basis,
6670	+	IntBinaryOperator reducer) {
6671	+	super(m, p, b); this.nextRight = nextRight;
6672	+	this.transformer = transformer;
6673	+	this.basis = basis; this.reducer = reducer;
6674	+	}
6675	+	public final Integer getRawResult() { return result; }
6676	+	@SuppressWarnings("unchecked") public final void compute() {
6677	+	final ToIntBiFunction<? super K, ? super V> transformer;
6678	+	final IntBinaryOperator reducer;
6679	+	if ((transformer = this.transformer) != null &&
6680	+	(reducer = this.reducer) != null) {
6681	+	int r = this.basis;
6682	+	for (int b; (b = preSplit()) > 0;)
6683	+	(rights = new MapReduceMappingsToIntTask<K,V>
6684	+	(map, this, b, rights, transformer, r, reducer)).fork();
6685	+	V v;
6686	+	while ((v = advance()) != null)
6687	+	r = reducer.applyAsInt(r, transformer.applyAsInt(nextKey, v));
6688	+	result = r;
6689	+	CountedCompleter<?> c;
6690	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6691	+	MapReduceMappingsToIntTask<K,V>
6692	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6693	+	s = t.rights;
6694	+	while (s != null) {
6695	+	t.result = reducer.applyAsInt(t.result, s.result);
6696	+	s = t.rights = s.nextRight;
6697	+	}
6698	+	}
6699	+	}
6700	+	}
6701	+	}
6702	+
6703	+	// Unsafe mechanics
6704	+	private static final sun.misc.Unsafe U;
6705	+	private static final long SIZECTL;
6706	+	private static final long TRANSFERINDEX;
6707	+	private static final long TRANSFERORIGIN;
6708	+	private static final long BASECOUNT;
6709	+	private static final long CELLSBUSY;
6710	+	private static final long CELLVALUE;
6711	+	private static final long ABASE;
6712	+	private static final int ASHIFT;
6713	+
6714	+	static {
6715	+	try {
6716	+	U = sun.misc.Unsafe.getUnsafe();
6717	+	Class<?> k = ConcurrentHashMap.class;
6718	+	SIZECTL = U.objectFieldOffset
6719	+	(k.getDeclaredField("sizeCtl"));
6720	+	TRANSFERINDEX = U.objectFieldOffset
6721	+	(k.getDeclaredField("transferIndex"));
6722	+	TRANSFERORIGIN = U.objectFieldOffset
6723	+	(k.getDeclaredField("transferOrigin"));
6724	+	BASECOUNT = U.objectFieldOffset
6725	+	(k.getDeclaredField("baseCount"));
6726	+	CELLSBUSY = U.objectFieldOffset
6727	+	(k.getDeclaredField("cellsBusy"));
6728	+	Class<?> ck = Cell.class;
6729	+	CELLVALUE = U.objectFieldOffset
6730	+	(ck.getDeclaredField("value"));
6731	+	Class<?> sc = Node[].class;
6732	+	ABASE = U.arrayBaseOffset(sc);
6733	+	int scale = U.arrayIndexScale(sc);
6734	+	if ((scale & (scale - 1)) != 0)
6735	+	throw new Error("data type scale not a power of two");
6736	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6737	+	} catch (Exception e) {
6738	+	throw new Error(e);
6739	+	}
6740	+	}
6741	+
6742		}

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