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Revision 1.24 by dl, Fri Oct 10 23:51:28 2003 UTC vs.
Revision 1.162 by dl, Wed Jan 16 15:04:03 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. Use, modify, and
4	<	* redistribute this code in any way without acknowledgement.
3	>	* Expert Group and released to the public domain, as explained at
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>	import java.util.concurrent.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>) ordinarily
48	<	* overlap with update operations (including <tt>put</tt> and
49	<	* <tt>remove</tt>). Retrievals reflect the results of the most
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.  For aggregate operations such as <tt>putAll</tt> and
52	<	* <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 <tt>ConcurrentModificationException</tt>.
57	<	* However, Iterators are designed to be used by only one thread at a
58	<	* time.
59	<	*
60	<	* <p> The allowed concurrency among update operations is guided by
61	<	* the optional <tt>concurrencyLevel</tt> constructor argument
62	<	* (default 16), which is used as a hint for internal sizing.  The
63	<	* table is internally partitioned to try to permit the indicated
64	<	* number of concurrent updates without contention. Because placement
65	<	* in hash tables is essentially random, the actual concurrency will
66	<	* vary.  Ideally, you should choose a value to accommodate as many
67	<	* threads as will ever concurrently access the table. Using a
68	<	* significantly higher value than you need can waste space and time,
69	<	* and a significantly lower value can lead to thread contention. But
70	<	* overestimates and underestimates within an order of magnitude do
71	<	* not usually have much noticeable impact.
72	<	*
73	<	* <p>This class implements all of the <em>optional</em> methods
74	<	* of the {@link Map} and {@link Iterator} interfaces.
75	<	*
76	<	* <p> Like {@link java.util.Hashtable} but unlike {@link
77	<	* java.util.HashMap}, this class does NOT allow <tt>null</tt> to be
78	<	* used as a key or value.
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}. For example, to add a count to a {@code
99	>	* ConcurrentHashMap<String,LongAdder> freqs}, you can use {@code
100	>	* 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 {@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">
210	>	* Java Collections Framework</a>.
211		*
212		* @since 1.5
213		* @author Doug Lea
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>, Cloneable, 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 number of table slots for this table.
410	<	* Used when not otherwise specified in 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	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
416	>
417	>	/**
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	<	private static int DEFAULT_INITIAL_CAPACITY = 16;
421	>	private static final int DEFAULT_CAPACITY = 16;
422
423		/**
424	<	* The maximum capacity, used if a higher value is implicitly
425	<	* specified by either of the constructors with arguments.  MUST
83	<	* be a power of two <= 1<<30 to ensure that entries are indexible
84	<	* using ints.
424	>	* The largest possible (non-power of two) array size.
425	>	* Needed by toArray and related methods.
426		*/
427	<	static final int MAXIMUM_CAPACITY = 1 << 30;
427	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
428
429		/**
430	<	* The default load factor for this table.  Used when not
431	<	* otherwise specified in constructor.
430	>	* The default concurrency level for this table. Unused but
431	>	* defined for compatibility with previous versions of this class.
432		*/
433	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
433	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
434
435		/**
436	<	* The default number of concurrency control segments.
437	<	**/
438	<	private static final int DEFAULT_SEGMENTS = 16;
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	>	private static final float LOAD_FACTOR = 0.75f;
443
444		/**
445	<	* The maximum number of segments to allow; used to bound ctor arguments.
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	>	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	<	private static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
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.
487	<	**/
488	<	private final int segmentMask;
485	>	* The array of bins. Lazily initialized upon first insertion.
486	>	* Size is always a power of two. Accessed directly by iterators.
487	>	*/
488	>	transient volatile Node<V>[] table;
489
490		/**
491	<	* Shift value for indexing within segments.
492	<	**/
493	<	private final int segmentShift;
491	>	* The next table to use; non-null only while resizing.
492	>	*/
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	<	private final Segment[] segments;
500	>	private transient volatile long baseCount;
501
502	<	private transient Set<K> keySet;
503	<	private transient Set<Map.Entry<K,V>> entrySet;
504	<	private 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	<	* Return a hash code for non-null Object x.
130	<	* Uses the same hash code spreader as most other j.u hash tables.
131	<	* @param x the object serving as a key
132	<	* @return the hash code
518	>	* The least available table index to split while resizing.
519		*/
520	<	private static int hash(Object x) {
521	<	int h = x.hashCode();
522	<	h += ~(h << 9);
523	<	h ^=  (h >>> 14);
524	<	h +=  (h << 4);
525	<	h ^=  (h >>> 10);
526	<	return h;
520	>	private transient volatile int transferOrigin;
521	>
522	>	/**
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	>
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	>	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	<	* Return the segment that should be used for key with given hash
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	<	private Segment<K,V> segmentFor(int hash) {
582	<	return (Segment<K,V>) segments[(hash >>> segmentShift) & segmentMask];
581	>	static class Node<V> {
582	>	final int hash;
583	>	final Object key;
584	>	volatile V val;
585	>	volatile Node<V> next;
586	>
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;
592	>	}
593		}
594
595	<	/* ---------------- Inner Classes -------------- */
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	<	private 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
167	<	* is less than two for the default load factor threshold.)
168	<	*
169	<	* Read operations can thus proceed without locking, but rely
170	<	* on a memory barrier to ensure that completed write
171	<	* operations performed by other threads are
172	<	* noticed. Conveniently, the "count" field, tracking the
173	<	* number of elements, can also serve as the volatile variable
174	<	* providing proper read/write barriers. This is convenient
175	<	* because this field needs to be read in many read operations
176	<	* anyway.
177	<	*
178	<	* Implementors note. The basic rules for all this are:
179	<	*
180	<	*   - All unsynchronized read operations must first read the
181	<	*     "count" field, and should not look at table entries if
182	<	*     it is 0.
183	<	*
184	<	*   - All synchronized write operations should write to
185	<	*     the "count" field after updating. The operations must not
186	<	*     take any action that could even momentarily cause
187	<	*     a concurrent read operation to see inconsistent
188	<	*     data. This is made easier by the nature of the read
189	<	*     operations in Map. For example, no operation
190	<	*     can reveal that the table has grown but the threshold
191	<	*     has not yet been updated, so there are no atomicity
192	<	*     requirements for this with respect to reads.
193	<	*
194	<	* As a guide, all critical volatile reads and writes are marked
195	<	* in code comments.
196	<	*/
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; used for checking lack of modifications
708	<	* in bulk-read methods.
709	<	*/
710	<	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 (int)(capacity *
214	<	* loadFactor).)
724	>	* Returns the TreeNode (or null if not found) for the given key
725	>	* starting at given root.
726		*/
727	<	private 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 HashEntry[] 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
226	<	* links to outer object.
227	<	* @serial
786	>	* Finds or adds a node.
787	>	* @return null if added
788		*/
789	<	private final float loadFactor;
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	<	Segment(int initialCapacity, float lf) {
824	<	loadFactor = lf;
825	<	setTable(new HashEntry[initialCapacity]);
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	<	* Set table to new HashEntry array.
893	<	* Call only while holding lock or in constructor.
894	<	**/
895	<	private void setTable(HashEntry[] newTable) {
896	<	table = newTable;
897	<	threshold = (int)(newTable.length * loadFactor);
898	<	count = count; // write-volatile
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	>	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	<	/* Specialized implementations of map methods */
1064	>	/* ---------------- Collision reduction methods -------------- */
1065
1066	<	V get(K key, int hash) {
1067	<	if (count != 0) { // read-volatile
1068	<	HashEntry[] tab = table;
1069	<	int index = hash & (tab.length - 1);
1070	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1071	<	while (e != null) {
1072	<	if (e.hash == hash && key.equals(e.key))
1073	<	return e.value;
1074	<	e = e.next;
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	>	/* ---------------- 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	<	return null;
1117	>	break;
1118		}
1119	+	return null;
1120	+	}
1121
1122	<	boolean containsKey(Object key, int hash) {
1123	<	if (count != 0) { // read-volatile
1124	<	HashEntry[] tab = table;
1125	<	int index = hash & (tab.length - 1);
1126	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1127	<	while (e != null) {
1128	<	if (e.hash == hash && key.equals(e.key))
1129	<	return true;
1130	<	e = e.next;
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	>	}
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		}
273	–	return false;
1207		}
1208	+	return oldVal;
1209	+	}
1210	+
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	<	boolean containsValue(Object value) {
1230	<	if (count != 0) { // read-volatile
1231	<	HashEntry[] tab = table;
1232	<	int len = tab.length;
1233	<	for (int i = 0 ; i < len; i++)
1234	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
1235	<	if (value.equals(e.value))
1236	<	return true;
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		}
285	–	return false;
1304		}
1305	+	addCount(1L, len);
1306	+	return null;
1307	+	}
1308
1309	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1310	<	lock();
1311	<	try {
1312	<	int c = count;
1313	<	HashEntry[] tab = table;
1314	<	int index = hash & (tab.length - 1);
1315	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1316	<
1317	<	for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
1318	<	if (e.hash == hash && key.equals(e.key)) {
1319	<	V oldValue = e.value;
1320	<	if (!onlyIfAbsent)
1321	<	e.value = value;
1322	<	++modCount;
1323	<	count = c; // write-volatile
1324	<	return oldValue;
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	+	}
1405	+	}
1406	+	if (val != null)
1407	+	addCount(1L, len);
1408	+	return val;
1409	+	}
1410
1411	<	tab[index] = new HashEntry<K,V>(hash, key, value, first);
1412	<	++modCount;
1413	<	++c;
1414	<	count = c; // write-volatile
1415	<	if (c > threshold)
1416	<	setTable(rehash(tab));
1417	<	return null;
1418	<	} finally {
1419	<	unlock();
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	<	private HashEntry[] rehash(HashEntry[] oldTable) {
1526	<	int oldCapacity = oldTable.length;
1527	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1528	<	return oldTable;
1529	<
1530	<	/*
1531	<	* Reclassify nodes in each list to new Map.  Because we are
1532	<	* using power-of-two expansion, the elements from each bin
1533	<	* must either stay at same index, or move with a power of two
1534	<	* offset. We eliminate unnecessary node creation by catching
1535	<	* cases where old nodes can be reused because their next
1536	<	* fields won't change. Statistically, at the default
1537	<	* threshhold, only about one-sixth of them need cloning when
1538	<	* a table doubles. The nodes they replace will be garbage
1539	<	* collectable as soon as they are no longer referenced by any
1540	<	* reader thread that may be in the midst of traversing table
1541	<	* right now.
1542	<	*/
1543	<
1544	<	HashEntry[] newTable = new HashEntry[oldCapacity << 1];
1545	<	int sizeMask = newTable.length - 1;
1546	<	for (int i = 0; i < oldCapacity ; i++) {
1547	<	// We need to guarantee that any existing reads of old Map can
1548	<	//  proceed. So we cannot yet null out each bin.
1549	<	HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
1550	<
1551	<	if (e != null) {
1552	<	HashEntry<K,V> next = e.next;
1553	<	int idx = e.hash & sizeMask;
1554	<
1555	<	//  Single node on list
1556	<	if (next == null)
1557	<	newTable[idx] = e;
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	>	}
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	+	/** 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	<	// Reuse trailing consecutive sequence at same slot
1672	<	HashEntry<K,V> lastRun = e;
1673	<	int lastIdx = idx;
1674	<	for (HashEntry<K,V> last = next;
1675	<	last != null;
1676	<	last = last.next) {
1677	<	int k = last.hash & sizeMask;
1678	<	if (k != lastIdx) {
1679	<	lastIdx = k;
1680	<	lastRun = last;
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	<	newTable[lastIdx] = lastRun;
1694	>	if (len != 0) {
1695	>	if (len > 1)
1696	>	addCount(delta, len);
1697	>	break;
1698	>	}
1699	>	}
1700	>	}
1701	>	}
1702	>	} finally {
1703	>	if (delta != 0L)
1704	>	addCount(delta, 2);
1705	>	}
1706	>	if (npe)
1707	>	throw new NullPointerException();
1708	>	}
1709
1710	<	// Clone all remaining nodes
1711	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1712	<	int k = p.hash & sizeMask;
1713	<	newTable[k] = new HashEntry<K,V>(p.hash,
1714	<	p.key,
1715	<	p.value,
1716	<	(HashEntry<K,V>) newTable[k]);
1710	>	/**
1711	>	* Implementation for clear. Steps through each bin, removing all
1712	>	* nodes.
1713	>	*/
1714	>	@SuppressWarnings("unchecked") private final void internalClear() {
1715	>	long delta = 0L; // negative number of deletions
1716	>	int i = 0;
1717	>	Node<V>[] tab = table;
1718	>	while (tab != null && i < tab.length) {
1719	>	Node<V> f = tabAt(tab, i);
1720	>	if (f == null)
1721	>	++i;
1722	>	else if (f.hash < 0) {
1723	>	Object fk;
1724	>	if ((fk = f.key) instanceof TreeBin) {
1725	>	TreeBin<V> t = (TreeBin<V>)fk;
1726	>	t.acquire(0);
1727	>	try {
1728	>	if (tabAt(tab, i) == f) {
1729	>	for (Node<V> p = t.first; p != null; p = p.next) {
1730	>	if (p.val != null) { // (currently always true)
1731	>	p.val = null;
1732	>	--delta;
1733	>	}
1734	>	}
1735	>	t.first = null;
1736	>	t.root = null;
1737	>	++i;
1738	>	}
1739	>	} finally {
1740	>	t.release(0);
1741	>	}
1742	>	}
1743	>	else
1744	>	tab = (Node<V>[])fk;
1745	>	}
1746	>	else {
1747	>	synchronized (f) {
1748	>	if (tabAt(tab, i) == f) {
1749	>	for (Node<V> e = f; e != null; e = e.next) {
1750	>	if (e.val != null) {  // (currently always true)
1751	>	e.val = null;
1752	>	--delta;
1753	>	}
1754		}
1755	+	setTabAt(tab, i, null);
1756	+	++i;
1757		}
1758		}
1759		}
379	–	return newTable;
1760		}
1761	+	if (delta != 0L)
1762	+	addCount(delta, -1);
1763	+	}
1764
1765	<	/**
383	<	* Remove; match on key only if value null, else match both.
384	<	*/
385	<	V remove(Object key, int hash, Object value) {
386	<	lock();
387	<	try {
388	<	int c = count;
389	<	HashEntry[] tab = table;
390	<	int index = hash & (tab.length - 1);
391	<	HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
1765	>	/* ---------------- Table Initialization and Resizing -------------- */
1766
1767	<	HashEntry<K,V> e = first;
1768	<	for (;;) {
1769	<	if (e == null)
1770	<	return null;
1771	<	if (e.hash == hash && key.equals(e.key))
1767	>	/**
1768	>	* Returns a power of two table size for the given desired capacity.
1769	>	* See Hackers Delight, sec 3.2
1770	>	*/
1771	>	private static final int tableSizeFor(int c) {
1772	>	int n = c - 1;
1773	>	n |= n >>> 1;
1774	>	n |= n >>> 2;
1775	>	n |= n >>> 4;
1776	>	n |= n >>> 8;
1777	>	n |= n >>> 16;
1778	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1779	>	}
1780	>
1781	>	/**
1782	>	* Initializes table, using the size recorded in sizeCtl.
1783	>	*/
1784	>	@SuppressWarnings("unchecked") private final Node<V>[] initTable() {
1785	>	Node<V>[] tab; int sc;
1786	>	while ((tab = table) == null) {
1787	>	if ((sc = sizeCtl) < 0)
1788	>	Thread.yield(); // lost initialization race; just spin
1789	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1790	>	try {
1791	>	if ((tab = table) == null) {
1792	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1793	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1794	>	table = tab = (Node<V>[])tb;
1795	>	sc = n - (n >>> 2);
1796	>	}
1797	>	} finally {
1798	>	sizeCtl = sc;
1799	>	}
1800	>	break;
1801	>	}
1802	>	}
1803	>	return tab;
1804	>	}
1805	>
1806	>	/**
1807	>	* Adds to count, and if table is too small and not already
1808	>	* resizing, initiates transfer. If already resizing, helps
1809	>	* perform transfer if work is available.  Rechecks occupancy
1810	>	* after a transfer to see if another resize is already needed
1811	>	* because resizings are lagging additions.
1812	>	*
1813	>	* @param x the count to add
1814	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
1815	>	*/
1816	>	private final void addCount(long x, int check) {
1817	>	Cell[] as; long b, s;
1818	>	if ((as = counterCells) != null ||
1819	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1820	>	Cell a; long v; int m;
1821	>	boolean uncontended = true;
1822	>	if (as == null || (m = as.length - 1) < 0 ||
1823	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
1824	>	!(uncontended =
1825	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1826	>	fullAddCount(x, uncontended);
1827	>	return;
1828	>	}
1829	>	if (check <= 1)
1830	>	return;
1831	>	s = sumCount();
1832	>	}
1833	>	if (check >= 0) {
1834	>	Node<V>[] tab, nt; int sc;
1835	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1836	>	tab.length < MAXIMUM_CAPACITY) {
1837	>	if (sc < 0) {
1838	>	if (sc == -1 || transferIndex <= transferOrigin ||
1839	>	(nt = nextTable) == null)
1840		break;
1841	<	e = e.next;
1841	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1842	>	transfer(tab, nt);
1843		}
1844	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1845	+	transfer(tab, null);
1846	+	s = sumCount();
1847	+	}
1848	+	}
1849	+	}
1850
1851	<	V oldValue = e.value;
1852	<	if (value != null && !value.equals(oldValue))
1853	<	return null;
1854	<
1855	<	// All entries following removed node can stay in list, but
1856	<	// all preceeding ones need to be cloned.
1857	<	HashEntry<K,V> newFirst = e.next;
1858	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
1859	<	newFirst = new HashEntry<K,V>(p.hash, p.key,
1860	<	p.value, newFirst);
1861	<	tab[index] = newFirst;
1862	<	++modCount;
1863	<	count = c-1; // write-volatile
1864	<	return oldValue;
1865	<	} finally {
1866	<	unlock();
1851	>	/**
1852	>	* Tries to presize table to accommodate the given number of elements.
1853	>	*
1854	>	* @param size number of elements (doesn't need to be perfectly accurate)
1855	>	*/
1856	>	@SuppressWarnings("unchecked") private final void tryPresize(int size) {
1857	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1858	>	tableSizeFor(size + (size >>> 1) + 1);
1859	>	int sc;
1860	>	while ((sc = sizeCtl) >= 0) {
1861	>	Node<V>[] tab = table; int n;
1862	>	if (tab == null || (n = tab.length) == 0) {
1863	>	n = (sc > c) ? sc : c;
1864	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1865	>	try {
1866	>	if (table == tab) {
1867	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1868	>	table = (Node<V>[])tb;
1869	>	sc = n - (n >>> 2);
1870	>	}
1871	>	} finally {
1872	>	sizeCtl = sc;
1873	>	}
1874	>	}
1875		}
1876	+	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1877	+	break;
1878	+	else if (tab == table &&
1879	+	U.compareAndSwapInt(this, SIZECTL, sc, -2))
1880	+	transfer(tab, null);
1881		}
1882	+	}
1883
1884	<	void clear() {
1885	<	lock();
1884	>	/*
1885	>	* Moves and/or copies the nodes in each bin to new table. See
1886	>	* above for explanation.
1887	>	*/
1888	>	@SuppressWarnings("unchecked") private final void transfer
1889	>	(Node<V>[] tab, Node<V>[] nextTab) {
1890	>	int n = tab.length, stride;
1891	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1892	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
1893	>	if (nextTab == null) {            // initiating
1894		try {
1895	<	HashEntry[] tab = table;
1896	<	for (int i = 0; i < tab.length ; i++)
1897	<	tab[i] = null;
1898	<	++modCount;
1899	<	count = 0; // write-volatile
1900	<	} finally {
1901	<	unlock();
1895	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1];
1896	>	nextTab = (Node<V>[])tb;
1897	>	} catch (Throwable ex) {      // try to cope with OOME
1898	>	sizeCtl = Integer.MAX_VALUE;
1899	>	return;
1900	>	}
1901	>	nextTable = nextTab;
1902	>	transferOrigin = n;
1903	>	transferIndex = n;
1904	>	Node<V> rev = new Node<V>(MOVED, tab, null, null);
1905	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
1906	>	int nextk = (k > stride) ? k - stride : 0;
1907	>	for (int m = nextk; m < k; ++m)
1908	>	nextTab[m] = rev;
1909	>	for (int m = n + nextk; m < n + k; ++m)
1910	>	nextTab[m] = rev;
1911	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
1912	>	}
1913	>	}
1914	>	int nextn = nextTab.length;
1915	>	Node<V> fwd = new Node<V>(MOVED, nextTab, null, null);
1916	>	boolean advance = true;
1917	>	for (int i = 0, bound = 0;;) {
1918	>	int nextIndex, nextBound; Node<V> f; Object fk;
1919	>	while (advance) {
1920	>	if (--i >= bound)
1921	>	advance = false;
1922	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
1923	>	i = -1;
1924	>	advance = false;
1925	>	}
1926	>	else if (U.compareAndSwapInt
1927	>	(this, TRANSFERINDEX, nextIndex,
1928	>	nextBound = (nextIndex > stride ?
1929	>	nextIndex - stride : 0))) {
1930	>	bound = nextBound;
1931	>	i = nextIndex - 1;
1932	>	advance = false;
1933	>	}
1934	>	}
1935	>	if (i < 0 || i >= n || i + n >= nextn) {
1936	>	for (int sc;;) {
1937	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
1938	>	if (sc == -1) {
1939	>	nextTable = null;
1940	>	table = nextTab;
1941	>	sizeCtl = (n << 1) - (n >>> 1);
1942	>	}
1943	>	return;
1944	>	}
1945	>	}
1946	>	}
1947	>	else if ((f = tabAt(tab, i)) == null) {
1948	>	if (casTabAt(tab, i, null, fwd)) {
1949	>	setTabAt(nextTab, i, null);
1950	>	setTabAt(nextTab, i + n, null);
1951	>	advance = true;
1952	>	}
1953	>	}
1954	>	else if (f.hash >= 0) {
1955	>	synchronized (f) {
1956	>	if (tabAt(tab, i) == f) {
1957	>	int runBit = f.hash & n;
1958	>	Node<V> lastRun = f, lo = null, hi = null;
1959	>	for (Node<V> p = f.next; p != null; p = p.next) {
1960	>	int b = p.hash & n;
1961	>	if (b != runBit) {
1962	>	runBit = b;
1963	>	lastRun = p;
1964	>	}
1965	>	}
1966	>	if (runBit == 0)
1967	>	lo = lastRun;
1968	>	else
1969	>	hi = lastRun;
1970	>	for (Node<V> p = f; p != lastRun; p = p.next) {
1971	>	int ph = p.hash;
1972	>	Object pk = p.key; V pv = p.val;
1973	>	if ((ph & n) == 0)
1974	>	lo = new Node<V>(ph, pk, pv, lo);
1975	>	else
1976	>	hi = new Node<V>(ph, pk, pv, hi);
1977	>	}
1978	>	setTabAt(nextTab, i, lo);
1979	>	setTabAt(nextTab, i + n, hi);
1980	>	setTabAt(tab, i, fwd);
1981	>	advance = true;
1982	>	}
1983	>	}
1984	>	}
1985	>	else if ((fk = f.key) instanceof TreeBin) {
1986	>	TreeBin<V> t = (TreeBin<V>)fk;
1987	>	t.acquire(0);
1988	>	try {
1989	>	if (tabAt(tab, i) == f) {
1990	>	TreeBin<V> lt = new TreeBin<V>();
1991	>	TreeBin<V> ht = new TreeBin<V>();
1992	>	int lc = 0, hc = 0;
1993	>	for (Node<V> e = t.first; e != null; e = e.next) {
1994	>	int h = e.hash;
1995	>	Object k = e.key; V v = e.val;
1996	>	if ((h & n) == 0) {
1997	>	++lc;
1998	>	lt.putTreeNode(h, k, v);
1999	>	}
2000	>	else {
2001	>	++hc;
2002	>	ht.putTreeNode(h, k, v);
2003	>	}
2004	>	}
2005	>	Node<V> ln, hn; // throw away trees if too small
2006	>	if (lc < TREE_THRESHOLD) {
2007	>	ln = null;
2008	>	for (Node<V> p = lt.first; p != null; p = p.next)
2009	>	ln = new Node<V>(p.hash, p.key, p.val, ln);
2010	>	}
2011	>	else
2012	>	ln = new Node<V>(MOVED, lt, null, null);
2013	>	setTabAt(nextTab, i, ln);
2014	>	if (hc < TREE_THRESHOLD) {
2015	>	hn = null;
2016	>	for (Node<V> p = ht.first; p != null; p = p.next)
2017	>	hn = new Node<V>(p.hash, p.key, p.val, hn);
2018	>	}
2019	>	else
2020	>	hn = new Node<V>(MOVED, ht, null, null);
2021	>	setTabAt(nextTab, i + n, hn);
2022	>	setTabAt(tab, i, fwd);
2023	>	advance = true;
2024	>	}
2025	>	} finally {
2026	>	t.release(0);
2027	>	}
2028	>	}
2029	>	else
2030	>	advance = true; // already processed
2031	>	}
2032	>	}
2033	>
2034	>	/* ---------------- Counter support -------------- */
2035	>
2036	>	final long sumCount() {
2037	>	Cell[] as = counterCells; Cell a;
2038	>	long sum = baseCount;
2039	>	if (as != null) {
2040	>	for (int i = 0; i < as.length; ++i) {
2041	>	if ((a = as[i]) != null)
2042	>	sum += a.value;
2043	>	}
2044	>	}
2045	>	return sum;
2046	>	}
2047	>
2048	>	// See LongAdder version for explanation
2049	>	private final void fullAddCount(long x, boolean wasUncontended) {
2050	>	int h;
2051	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2052	>	ThreadLocalRandom.localInit();      // force initialization
2053	>	h = ThreadLocalRandom.getProbe();
2054	>	wasUncontended = true;
2055	>	}
2056	>	boolean collide = false;                // True if last slot nonempty
2057	>	for (;;) {
2058	>	Cell[] as; Cell a; int n; long v;
2059	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2060	>	if ((a = as[(n - 1) & h]) == null) {
2061	>	if (cellsBusy == 0) {            // Try to attach new Cell
2062	>	Cell r = new Cell(x); // Optimistic create
2063	>	if (cellsBusy == 0 &&
2064	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2065	>	boolean created = false;
2066	>	try {               // Recheck under lock
2067	>	Cell[] rs; int m, j;
2068	>	if ((rs = counterCells) != null &&
2069	>	(m = rs.length) > 0 &&
2070	>	rs[j = (m - 1) & h] == null) {
2071	>	rs[j] = r;
2072	>	created = true;
2073	>	}
2074	>	} finally {
2075	>	cellsBusy = 0;
2076	>	}
2077	>	if (created)
2078	>	break;
2079	>	continue;           // Slot is now non-empty
2080	>	}
2081	>	}
2082	>	collide = false;
2083	>	}
2084	>	else if (!wasUncontended)       // CAS already known to fail
2085	>	wasUncontended = true;      // Continue after rehash
2086	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2087	>	break;
2088	>	else if (counterCells != as || n >= NCPU)
2089	>	collide = false;            // At max size or stale
2090	>	else if (!collide)
2091	>	collide = true;
2092	>	else if (cellsBusy == 0 &&
2093	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2094	>	try {
2095	>	if (counterCells == as) {// Expand table unless stale
2096	>	Cell[] rs = new Cell[n << 1];
2097	>	for (int i = 0; i < n; ++i)
2098	>	rs[i] = as[i];
2099	>	counterCells = rs;
2100	>	}
2101	>	} finally {
2102	>	cellsBusy = 0;
2103	>	}
2104	>	collide = false;
2105	>	continue;                   // Retry with expanded table
2106	>	}
2107	>	h = ThreadLocalRandom.advanceProbe(h);
2108	>	}
2109	>	else if (cellsBusy == 0 && counterCells == as &&
2110	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2111	>	boolean init = false;
2112	>	try {                           // Initialize table
2113	>	if (counterCells == as) {
2114	>	Cell[] rs = new Cell[2];
2115	>	rs[h & 1] = new Cell(x);
2116	>	counterCells = rs;
2117	>	init = true;
2118	>	}
2119	>	} finally {
2120	>	cellsBusy = 0;
2121	>	}
2122	>	if (init)
2123	>	break;
2124		}
2125	+	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2126	+	break;                          // Fall back on using base
2127		}
2128		}
2129
2130	+	/* ----------------Table Traversal -------------- */
2131	+
2132		/**
2133	<	* ConcurrentHashMap list entry.
2133	>	* Encapsulates traversal for methods such as containsValue; also
2134	>	* serves as a base class for other iterators and bulk tasks.
2135	>	*
2136	>	* At each step, the iterator snapshots the key ("nextKey") and
2137	>	* value ("nextVal") of a valid node (i.e., one that, at point of
2138	>	* snapshot, has a non-null user value). Because val fields can
2139	>	* change (including to null, indicating deletion), field nextVal
2140	>	* might not be accurate at point of use, but still maintains the
2141	>	* weak consistency property of holding a value that was once
2142	>	* valid. To support iterator.remove, the nextKey field is not
2143	>	* updated (nulled out) when the iterator cannot advance.
2144	>	*
2145	>	* Internal traversals directly access these fields, as in:
2146	>	* {@code while (it.advance() != null) { process(it.nextKey); }}
2147	>	*
2148	>	* Exported iterators must track whether the iterator has advanced
2149	>	* (in hasNext vs next) (by setting/checking/nulling field
2150	>	* nextVal), and then extract key, value, or key-value pairs as
2151	>	* return values of next().
2152	>	*
2153	>	* The iterator visits once each still-valid node that was
2154	>	* reachable upon iterator construction. It might miss some that
2155	>	* were added to a bin after the bin was visited, which is OK wrt
2156	>	* consistency guarantees. Maintaining this property in the face
2157	>	* of possible ongoing resizes requires a fair amount of
2158	>	* bookkeeping state that is difficult to optimize away amidst
2159	>	* volatile accesses.  Even so, traversal maintains reasonable
2160	>	* throughput.
2161	>	*
2162	>	* Normally, iteration proceeds bin-by-bin traversing lists.
2163	>	* However, if the table has been resized, then all future steps
2164	>	* must traverse both the bin at the current index as well as at
2165	>	* (index + baseSize); and so on for further resizings. To
2166	>	* paranoically cope with potential sharing by users of iterators
2167	>	* across threads, iteration terminates if a bounds checks fails
2168	>	* for a table read.
2169	>	*
2170	>	* This class supports both Spliterator-based traversal and
2171	>	* CountedCompleter-based bulk tasks. The same "batch" field is
2172	>	* used, but in slightly different ways, in the two cases.  For
2173	>	* Spliterators, it is a saturating (at Integer.MAX_VALUE)
2174	>	* estimate of element coverage. For CHM tasks, it is a pre-scaled
2175	>	* size that halves down to zero for leaf tasks, that is only
2176	>	* computed upon execution of the task. (Tasks can be submitted to
2177	>	* any pool, of any size, so we don't know scale factors until
2178	>	* running.)
2179	>	*
2180	>	* This class extends CountedCompleter to streamline parallel
2181	>	* iteration in bulk operations. This adds only a few fields of
2182	>	* space overhead, which is small enough in cases where it is not
2183	>	* needed to not worry about it.  Because CountedCompleter is
2184	>	* Serializable, but iterators need not be, we need to add warning
2185	>	* suppressions.
2186		*/
2187	<	private static class HashEntry<K,V> implements Entry<K,V> {
2188	<	private final K key;
2189	<	private V value;
2190	<	private final int hash;
2191	<	private final HashEntry<K,V> next;
2187	>	@SuppressWarnings("serial") static class Traverser<K,V,R>
2188	>	extends CountedCompleter<R> {
2189	>	final ConcurrentHashMap<K, V> map;
2190	>	Node<V> next;        // the next entry to use
2191	>	Object nextKey;      // cached key field of next
2192	>	V nextVal;           // cached val field of next
2193	>	Node<V>[] tab;       // current table; updated if resized
2194	>	int index;           // index of bin to use next
2195	>	int baseIndex;       // current index of initial table
2196	>	int baseLimit;       // index bound for initial table
2197	>	int baseSize;        // initial table size
2198	>	int batch;           // split control
2199	>	/** Creates iterator for all entries in the table. */
2200	>	Traverser(ConcurrentHashMap<K, V> map) {
2201	>	this.map = map;
2202	>	Node<V>[] t;
2203	>	if ((t = tab = map.table) != null)
2204	>	baseLimit = baseSize = t.length;
2205	>	}
2206	>
2207	>	/** Task constructor */
2208	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it, int batch) {
2209	>	super(it);
2210	>	this.map = map;
2211	>	this.batch = batch; // -1 if unknown
2212	>	if (it == null) {
2213	>	Node<V>[] t;
2214	>	if ((t = tab = map.table) != null)
2215	>	baseLimit = baseSize = t.length;
2216	>	}
2217	>	else { // split parent
2218	>	this.tab = it.tab;
2219	>	this.baseSize = it.baseSize;
2220	>	int hi = this.baseLimit = it.baseLimit;
2221	>	it.baseLimit = this.index = this.baseIndex =
2222	>	(hi + it.baseIndex + 1) >>> 1;
2223	>	}
2224	>	}
2225
2226	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
2227	<	this.value = value;
2228	<	this.hash = hash;
2229	<	this.key = key;
2230	<	this.next = next;
2226	>	/** Spliterator constructor */
2227	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it) {
2228	>	super(it);
2229	>	this.map = map;
2230	>	if (it == null) {
2231	>	Node<V>[] t;
2232	>	if ((t = tab = map.table) != null)
2233	>	baseLimit = baseSize = t.length;
2234	>	long n = map.sumCount();
2235	>	batch = ((n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2236	>	(int)n);
2237	>	}
2238	>	else {
2239	>	this.tab = it.tab;
2240	>	this.baseSize = it.baseSize;
2241	>	int hi = this.baseLimit = it.baseLimit;
2242	>	it.baseLimit = this.index = this.baseIndex =
2243	>	(hi + it.baseIndex + 1) >>> 1;
2244	>	this.batch = it.batch >>>= 1;
2245	>	}
2246		}
2247
2248	<	public K getKey() {
2249	<	return key;
2248	>	/**
2249	>	* Advances next; returns nextVal or null if terminated.
2250	>	* See above for explanation.
2251	>	*/
2252	>	@SuppressWarnings("unchecked") final V advance() {
2253	>	Node<V> e = next;
2254	>	V ev = null;
2255	>	outer: do {
2256	>	if (e != null)                  // advance past used/skipped node
2257	>	e = e.next;
2258	>	while (e == null) {             // get to next non-null bin
2259	>	ConcurrentHashMap<K, V> m;
2260	>	Node<V>[] t; int b, i, n; Object ek; //  must use locals
2261	>	if ((t = tab) != null)
2262	>	n = t.length;
2263	>	else if ((m = map) != null && (t = tab = m.table) != null)
2264	>	n = baseLimit = baseSize = t.length;
2265	>	else
2266	>	break outer;
2267	>	if ((b = baseIndex) >= baseLimit ||
2268	>	(i = index) < 0 || i >= n)
2269	>	break outer;
2270	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2271	>	if ((ek = e.key) instanceof TreeBin)
2272	>	e = ((TreeBin<V>)ek).first;
2273	>	else {
2274	>	tab = (Node<V>[])ek;
2275	>	continue;           // restarts due to null val
2276	>	}
2277	>	}                           // visit upper slots if present
2278	>	index = (i += baseSize) < n ? i : (baseIndex = b + 1);
2279	>	}
2280	>	nextKey = e.key;
2281	>	} while ((ev = e.val) == null);    // skip deleted or special nodes
2282	>	next = e;
2283	>	return nextVal = ev;
2284		}
2285
2286	<	public V getValue() {
2287	<	return value;
2286	>	public final void remove() {
2287	>	Object k = nextKey;
2288	>	if (k == null && (advance() == null || (k = nextKey) == null))
2289	>	throw new IllegalStateException();
2290	>	map.internalReplace(k, null, null);
2291		}
2292
2293	<	public V setValue(V newValue) {
2294	<	// We aren't required to, and don't provide any
461	<	// visibility barriers for setting value.
462	<	if (newValue == null)
463	<	throw new NullPointerException();
464	<	V oldValue = this.value;
465	<	this.value = newValue;
466	<	return oldValue;
2293	>	public final boolean hasNext() {
2294	>	return nextVal != null || advance() != null;
2295		}
2296
2297	<	public boolean equals(Object o) {
2298	<	if (!(o instanceof Entry))
2299	<	return false;
2300	<	Entry<K,V> e = (Entry<K,V>)o;
2301	<	return (key.equals(e.getKey()) && value.equals(e.getValue()));
2297	>	public final boolean hasMoreElements() { return hasNext(); }
2298	>
2299	>	public void compute() { } // default no-op CountedCompleter body
2300	>
2301	>	/**
2302	>	* Returns a batch value > 0 if this task should (and must) be
2303	>	* split, if so, adding to pending count, and in any case
2304	>	* updating batch value. The initial batch value is approx
2305	>	* exp2 of the number of times (minus one) to split task by
2306	>	* two before executing leaf action. This value is faster to
2307	>	* compute and more convenient to use as a guide to splitting
2308	>	* than is the depth, since it is used while dividing by two
2309	>	* anyway.
2310	>	*/
2311	>	final int preSplit() {
2312	>	int b;  ForkJoinPool pool;
2313	>	if ((b = batch) < 0) { // force initialization
2314	>	int sp = (((pool = getPool()) == null) ?
2315	>	ForkJoinPool.getCommonPoolParallelism() :
2316	>	pool.getParallelism()) << 3; // slack of 8
2317	>	long n = map.sumCount();
2318	>	b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2319	>	}
2320	>	b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1);
2321	>	if ((batch = b) > 0)
2322	>	addToPendingCount(1);
2323	>	return b;
2324		}
2325
2326	<	public int hashCode() {
2327	<	return  key.hashCode() ^ value.hashCode();
2326	>	// spliterator support
2327	>
2328	>	public boolean hasExactSize() {
2329	>	return false;
2330		}
2331
2332	<	public String toString() {
2333	<	return key + "=" + value;
2332	>	public boolean hasExactSplits() {
2333	>	return false;
2334		}
483	–	}
2335
2336	+	public long estimateSize() {
2337	+	return batch;
2338	+	}
2339	+	}
2340
2341		/* ---------------- Public operations -------------- */
2342
2343		/**
2344	<	* Constructs a new, empty map with the specified initial
2345	<	* capacity and the specified load factor.
2344	>	* Creates a new, empty map with the default initial table size (16).
2345	>	*/
2346	>	public ConcurrentHashMap() {
2347	>	}
2348	>
2349	>	/**
2350	>	* Creates a new, empty map with an initial table size
2351	>	* accommodating the specified number of elements without the need
2352	>	* to dynamically resize.
2353	>	*
2354	>	* @param initialCapacity The implementation performs internal
2355	>	* sizing to accommodate this many elements.
2356	>	* @throws IllegalArgumentException if the initial capacity of
2357	>	* elements is negative
2358	>	*/
2359	>	public ConcurrentHashMap(int initialCapacity) {
2360	>	if (initialCapacity < 0)
2361	>	throw new IllegalArgumentException();
2362	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2363	>	MAXIMUM_CAPACITY :
2364	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2365	>	this.sizeCtl = cap;
2366	>	}
2367	>
2368	>	/**
2369	>	* Creates a new map with the same mappings as the given map.
2370	>	*
2371	>	* @param m the map
2372	>	*/
2373	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2374	>	this.sizeCtl = DEFAULT_CAPACITY;
2375	>	internalPutAll(m);
2376	>	}
2377	>
2378	>	/**
2379	>	* Creates a new, empty map with an initial table size based on
2380	>	* the given number of elements ({@code initialCapacity}) and
2381	>	* initial table density ({@code loadFactor}).
2382	>	*
2383	>	* @param initialCapacity the initial capacity. The implementation
2384	>	* performs internal sizing to accommodate this many elements,
2385	>	* given the specified load factor.
2386	>	* @param loadFactor the load factor (table density) for
2387	>	* establishing the initial table size
2388	>	* @throws IllegalArgumentException if the initial capacity of
2389	>	* elements is negative or the load factor is nonpositive
2390	>	*
2391	>	* @since 1.6
2392	>	*/
2393	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2394	>	this(initialCapacity, loadFactor, 1);
2395	>	}
2396	>
2397	>	/**
2398	>	* Creates a new, empty map with an initial table size based on
2399	>	* the given number of elements ({@code initialCapacity}), table
2400	>	* density ({@code loadFactor}), and number of concurrently
2401	>	* updating threads ({@code concurrencyLevel}).
2402		*
2403		* @param initialCapacity the initial capacity. The implementation
2404	<	* performs internal sizing to accommodate this many elements.
2405	<	* @param loadFactor  the load factor threshold, used to control resizing.
2404	>	* performs internal sizing to accommodate this many elements,
2405	>	* given the specified load factor.
2406	>	* @param loadFactor the load factor (table density) for
2407	>	* establishing the initial table size
2408		* @param concurrencyLevel the estimated number of concurrently
2409	<	* updating threads. The implementation performs internal sizing
2410	<	* to try to accommodate this many threads.
2409	>	* updating threads. The implementation may use this value as
2410	>	* a sizing hint.
2411		* @throws IllegalArgumentException if the initial capacity is
2412		* negative or the load factor or concurrencyLevel are
2413	<	* nonpositive.
2413	>	* nonpositive
2414		*/
2415		public ConcurrentHashMap(int initialCapacity,
2416	<	float loadFactor, int concurrencyLevel) {
2417	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2416	>	float loadFactor, int concurrencyLevel) {
2417	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2418		throw new IllegalArgumentException();
2419	+	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2420	+	initialCapacity = concurrencyLevel;   // as estimated threads
2421	+	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2422	+	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2423	+	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2424	+	this.sizeCtl = cap;
2425	+	}
2426
2427	<	if (concurrencyLevel > MAX_SEGMENTS)
2428	<	concurrencyLevel = MAX_SEGMENTS;
2429	<
2430	<	// Find power-of-two sizes best matching arguments
2431	<	int sshift = 0;
2432	<	int ssize = 1;
2433	<	while (ssize < concurrencyLevel) {
2434	<	++sshift;
2435	<	ssize <<= 1;
516	<	}
517	<	segmentShift = 32 - sshift;
518	<	segmentMask = ssize - 1;
519	<	this.segments = new Segment[ssize];
520	<
521	<	if (initialCapacity > MAXIMUM_CAPACITY)
522	<	initialCapacity = MAXIMUM_CAPACITY;
523	<	int c = initialCapacity / ssize;
524	<	if (c * ssize < initialCapacity)
525	<	++c;
526	<	int cap = 1;
527	<	while (cap < c)
528	<	cap <<= 1;
529	<
530	<	for (int i = 0; i < this.segments.length; ++i)
531	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2427	>	/**
2428	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2429	>	* from the given type to {@code Boolean.TRUE}.
2430	>	*
2431	>	* @return the new set
2432	>	*/
2433	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2434	>	return new KeySetView<K,Boolean>(new ConcurrentHashMap<K,Boolean>(),
2435	>	Boolean.TRUE);
2436		}
2437
2438		/**
2439	<	* Constructs a new, empty map with the specified initial
2440	<	* capacity,  and with default load factor and concurrencyLevel.
2439	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2440	>	* from the given type to {@code Boolean.TRUE}.
2441		*
2442		* @param initialCapacity The implementation performs internal
2443		* sizing to accommodate this many elements.
2444		* @throws IllegalArgumentException if the initial capacity of
2445	<	* elements is negative.
2445	>	* elements is negative
2446	>	* @return the new set
2447		*/
2448	<	public ConcurrentHashMap(int initialCapacity) {
2449	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2448	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2449	>	return new KeySetView<K,Boolean>
2450	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2451		}
2452
2453		/**
2454	<	* Constructs a new, empty map with a default initial capacity,
549	<	* load factor, and concurrencyLevel.
2454	>	* {@inheritDoc}
2455		*/
2456	<	public ConcurrentHashMap() {
2457	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2456	>	public boolean isEmpty() {
2457	>	return sumCount() <= 0L; // ignore transient negative values
2458		}
2459
2460		/**
2461	<	* Constructs a new map with the same mappings as the given map.  The
557	<	* map is created with a capacity of twice the number of mappings in
558	<	* the given map or 11 (whichever is greater), and a default load factor.
2461	>	* {@inheritDoc}
2462		*/
2463	<	public <A extends K, B extends V> ConcurrentHashMap(Map<A,B> t) {
2464	<	this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
2465	<	11),
2466	<	DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2467	<	putAll(t);
2463	>	public int size() {
2464	>	long n = sumCount();
2465	>	return ((n < 0L) ? 0 :
2466	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2467	>	(int)n);
2468		}
2469
2470	<	// inherit Map javadoc
2471	<	public boolean isEmpty() {
2472	<	/*
2473	<	* We need to keep track of per-segment modCounts to avoid ABA
2474	<	* problems in which an element in one segment was added and
2475	<	* in another removed during traversal, in which case the
2476	<	* table was never actually empty at any point. Note the
2477	<	* similar use of modCounts in the size() and containsValue()
2478	<	* methods, which are the only other methods also susceptible
2479	<	* to ABA problems.
2480	<	*/
2481	<	int[] mc = new int[segments.length];
579	<	int mcsum = 0;
580	<	for (int i = 0; i < segments.length; ++i) {
581	<	if (segments[i].count != 0)
582	<	return false;
583	<	else
584	<	mcsum += mc[i] = segments[i].modCount;
585	<	}
586	<	// If mcsum happens to be zero, then we know we got a snapshot
587	<	// before any modifications at all were made.  This is
588	<	// probably common enough to bother tracking.
589	<	if (mcsum != 0) {
590	<	for (int i = 0; i < segments.length; ++i) {
591	<	if (segments[i].count != 0 ||
592	<	mc[i] != segments[i].modCount)
593	<	return false;
594	<	}
595	<	}
596	<	return true;
2470	>	/**
2471	>	* Returns the number of mappings. This method should be used
2472	>	* instead of {@link #size} because a ConcurrentHashMap may
2473	>	* contain more mappings than can be represented as an int. The
2474	>	* value returned is an estimate; the actual count may differ if
2475	>	* there are concurrent insertions or removals.
2476	>	*
2477	>	* @return the number of mappings
2478	>	*/
2479	>	public long mappingCount() {
2480	>	long n = sumCount();
2481	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2482		}
2483
2484	<	// inherit Map javadoc
2485	<	public int size() {
2486	<	int[] mc = new int[segments.length];
2487	<	for (;;) {
2488	<	long sum = 0;
2489	<	int mcsum = 0;
2490	<	for (int i = 0; i < segments.length; ++i) {
2491	<	sum += segments[i].count;
2492	<	mcsum += mc[i] = segments[i].modCount;
2493	<	}
2494	<	int check = 0;
2495	<	if (mcsum != 0) {
2496	<	for (int i = 0; i < segments.length; ++i) {
612	<	check += segments[i].count;
613	<	if (mc[i] != segments[i].modCount) {
614	<	check = -1; // force retry
615	<	break;
616	<	}
617	<	}
618	<	}
619	<	if (check == sum) {
620	<	if (sum > Integer.MAX_VALUE)
621	<	return Integer.MAX_VALUE;
622	<	else
623	<	return (int)sum;
624	<	}
625	<	}
2484	>	/**
2485	>	* Returns the value to which the specified key is mapped,
2486	>	* or {@code null} if this map contains no mapping for the key.
2487	>	*
2488	>	* <p>More formally, if this map contains a mapping from a key
2489	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
2490	>	* then this method returns {@code v}; otherwise it returns
2491	>	* {@code null}.  (There can be at most one such mapping.)
2492	>	*
2493	>	* @throws NullPointerException if the specified key is null
2494	>	*/
2495	>	public V get(Object key) {
2496	>	return internalGet(key);
2497		}
2498
628	–
2499		/**
2500	<	* Returns the value to which the specified key is mapped in this table.
2500	>	* Returns the value to which the specified key is mapped,
2501	>	* or the given defaultValue if this map contains no mapping for the key.
2502		*
2503	<	* @param   key   a key in the table.
2504	<	* @return  the value to which the key is mapped in this table;
2505	<	*          <tt>null</tt> if the key is not mapped to any value in
2506	<	*          this table.
2507	<	* @throws  NullPointerException  if the key is
637	<	*               <tt>null</tt>.
2503	>	* @param key the key
2504	>	* @param defaultValue the value to return if this map contains
2505	>	* no mapping for the given key
2506	>	* @return the mapping for the key, if present; else the defaultValue
2507	>	* @throws NullPointerException if the specified key is null
2508		*/
2509	<	public V get(Object key) {
2510	<	int hash = hash(key); // throws NullPointerException if key null
2511	<	return segmentFor(hash).get((K) key, hash);
2509	>	public V getValueOrDefault(Object key, V defaultValue) {
2510	>	V v;
2511	>	return (v = internalGet(key)) == null ? defaultValue : v;
2512		}
2513
2514		/**
2515		* Tests if the specified object is a key in this table.
2516		*
2517	<	* @param   key   possible key.
2518	<	* @return  <tt>true</tt> if and only if the specified object
2519	<	*          is a key in this table, as determined by the
2520	<	*          <tt>equals</tt> method; <tt>false</tt> otherwise.
2521	<	* @throws  NullPointerException  if the key is
652	<	*               <tt>null</tt>.
2517	>	* @param  key   possible key
2518	>	* @return {@code true} if and only if the specified object
2519	>	*         is a key in this table, as determined by the
2520	>	*         {@code equals} method; {@code false} otherwise
2521	>	* @throws NullPointerException if the specified key is null
2522		*/
2523		public boolean containsKey(Object key) {
2524	<	int hash = hash(key); // throws NullPointerException if key null
656	<	return segmentFor(hash).containsKey(key, hash);
2524	>	return internalGet(key) != null;
2525		}
2526
2527		/**
2528	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2529	<	* specified value. Note: This method requires a full internal
2530	<	* traversal of the hash table, and so is much slower than
663	<	* method <tt>containsKey</tt>.
2528	>	* Returns {@code true} if this map maps one or more keys to the
2529	>	* specified value. Note: This method may require a full traversal
2530	>	* of the map, and is much slower than method {@code containsKey}.
2531		*
2532	<	* @param value value whose presence in this map is to be tested.
2533	<	* @return <tt>true</tt> if this map maps one or more keys to the
2534	<	* specified value.
2535	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2532	>	* @param value value whose presence in this map is to be tested
2533	>	* @return {@code true} if this map maps one or more keys to the
2534	>	*         specified value
2535	>	* @throws NullPointerException if the specified value is null
2536		*/
2537		public boolean containsValue(Object value) {
2538		if (value == null)
2539		throw new NullPointerException();
2540	<
2541	<	int[] mc = new int[segments.length];
2542	<	for (;;) {
2543	<	int sum = 0;
2544	<	int mcsum = 0;
678	<	for (int i = 0; i < segments.length; ++i) {
679	<	int c = segments[i].count;
680	<	mcsum += mc[i] = segments[i].modCount;
681	<	if (segments[i].containsValue(value))
682	<	return true;
683	<	}
684	<	boolean cleanSweep = true;
685	<	if (mcsum != 0) {
686	<	for (int i = 0; i < segments.length; ++i) {
687	<	int c = segments[i].count;
688	<	if (mc[i] != segments[i].modCount) {
689	<	cleanSweep = false;
690	<	break;
691	<	}
692	<	}
693	<	}
694	<	if (cleanSweep)
695	<	return false;
2540	>	V v;
2541	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2542	>	while ((v = it.advance()) != null) {
2543	>	if (v == value || value.equals(v))
2544	>	return true;
2545		}
2546	+	return false;
2547		}
2548
2549		/**
2550		* Legacy method testing if some key maps into the specified value
2551		* in this table.  This method is identical in functionality to
2552	<	* {@link #containsValue}, and  exists solely to ensure
2552	>	* {@link #containsValue}, and exists solely to ensure
2553		* full compatibility with class {@link java.util.Hashtable},
2554		* which supported this method prior to introduction of the
2555		* Java Collections framework.
2556	<
2557	<	* @param      value   a value to search for.
2558	<	* @return     <tt>true</tt> if and only if some key maps to the
2559	<	*             <tt>value</tt> argument in this table as
2560	<	*             determined by the <tt>equals</tt> method;
2561	<	*             <tt>false</tt> otherwise.
2562	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2556	>	*
2557	>	* @param  value a value to search for
2558	>	* @return {@code true} if and only if some key maps to the
2559	>	*         {@code value} argument in this table as
2560	>	*         determined by the {@code equals} method;
2561	>	*         {@code false} otherwise
2562	>	* @throws NullPointerException if the specified value is null
2563		*/
2564	<	public boolean contains(Object value) {
2564	>	@Deprecated public boolean contains(Object value) {
2565		return containsValue(value);
2566		}
2567
2568		/**
2569	<	* Maps the specified <tt>key</tt> to the specified
2570	<	* <tt>value</tt> in this table. Neither the key nor the
721	<	* value can be <tt>null</tt>. <p>
2569	>	* Maps the specified key to the specified value in this table.
2570	>	* Neither the key nor the value can be null.
2571		*
2572	<	* The value can be retrieved by calling the <tt>get</tt> method
2572	>	* <p>The value can be retrieved by calling the {@code get} method
2573		* with a key that is equal to the original key.
2574		*
2575	<	* @param      key     the table key.
2576	<	* @param      value   the value.
2577	<	* @return     the previous value of the specified key in this table,
2578	<	*             or <tt>null</tt> if it did not have one.
2579	<	* @throws  NullPointerException  if the key or value is
731	<	*               <tt>null</tt>.
2575	>	* @param key key with which the specified value is to be associated
2576	>	* @param value value to be associated with the specified key
2577	>	* @return the previous value associated with {@code key}, or
2578	>	*         {@code null} if there was no mapping for {@code key}
2579	>	* @throws NullPointerException if the specified key or value is null
2580		*/
2581		public V put(K key, V value) {
2582	<	if (value == null)
735	<	throw new NullPointerException();
736	<	int hash = hash(key);
737	<	return segmentFor(hash).put(key, hash, value, false);
2582	>	return internalPut(key, value, false);
2583		}
2584
2585		/**
2586	<	* If the specified key is not already associated
742	<	* with a value, associate it with the given value.
743	<	* This is equivalent to
744	<	* <pre>
745	<	*   if (!map.containsKey(key))
746	<	*      return map.put(key, value);
747	<	*   else
748	<	*      return map.get(key);
749	<	* </pre>
750	<	* Except that the action is performed atomically.
751	<	* @param key key with which the specified value is to be associated.
752	<	* @param value value to be associated with the specified key.
753	<	* @return previous value associated with specified key, or <tt>null</tt>
754	<	*         if there was no mapping for key.  A <tt>null</tt> return can
755	<	*         also indicate that the map previously associated <tt>null</tt>
756	<	*         with the specified key, if the implementation supports
757	<	*         <tt>null</tt> values.
758	<	*
759	<	* @throws UnsupportedOperationException if the <tt>put</tt> operation is
760	<	*            not supported by this map.
761	<	* @throws ClassCastException if the class of the specified key or value
762	<	*            prevents it from being stored in this map.
763	<	* @throws NullPointerException if the specified key or value is
764	<	*            <tt>null</tt>.
2586	>	* {@inheritDoc}
2587		*
2588	<	**/
2588	>	* @return the previous value associated with the specified key,
2589	>	*         or {@code null} if there was no mapping for the key
2590	>	* @throws NullPointerException if the specified key or value is null
2591	>	*/
2592		public V putIfAbsent(K key, V value) {
2593	<	if (value == null)
769	<	throw new NullPointerException();
770	<	int hash = hash(key);
771	<	return segmentFor(hash).put(key, hash, value, true);
2593	>	return internalPut(key, value, true);
2594		}
2595
774	–
2596		/**
2597		* Copies all of the mappings from the specified map to this one.
777	–	*
2598		* These mappings replace any mappings that this map had for any of the
2599	<	* keys currently in the specified Map.
2599	>	* keys currently in the specified map.
2600		*
2601	<	* @param t Mappings to be stored in this map.
2601	>	* @param m mappings to be stored in this map
2602		*/
2603	<	public void putAll(Map<? extends K, ? extends V> t) {
2604	<	for (Iterator<Map.Entry<? extends K, ? extends V>> it = (Iterator<Map.Entry<? extends K, ? extends V>>) t.entrySet().iterator(); it.hasNext(); ) {
785	<	Entry<? extends K, ? extends V> e = it.next();
786	<	put(e.getKey(), e.getValue());
787	<	}
2603	>	public void putAll(Map<? extends K, ? extends V> m) {
2604	>	internalPutAll(m);
2605		}
2606
2607		/**
2608	<	* Removes the key (and its corresponding value) from this
2609	<	* table. This method does nothing if the key is not in the table.
2608	>	* If the specified key is not already associated with a value (or
2609	>	* is mapped to {@code null}), attempts to compute its value using
2610	>	* the given mapping function and enters it into this map unless
2611	>	* {@code null}. The entire method invocation is performed
2612	>	* atomically, so the function is applied at most once per key.
2613	>	* Some attempted update operations on this map by other threads
2614	>	* may be blocked while computation is in progress, so the
2615	>	* computation should be short and simple, and must not attempt to
2616	>	* update any other mappings of this Map.
2617		*
2618	<	* @param   key   the key that needs to be removed.
2619	<	* @return  the value to which the key had been mapped in this table,
2620	<	*          or <tt>null</tt> if the key did not have a mapping.
2621	<	* @throws  NullPointerException  if the key is
2622	<	*               <tt>null</tt>.
2618	>	* @param key key with which the specified value is to be associated
2619	>	* @param mappingFunction the function to compute a value
2620	>	* @return the current (existing or computed) value associated with
2621	>	*         the specified key, or null if the computed value is null
2622	>	* @throws NullPointerException if the specified key or mappingFunction
2623	>	*         is null
2624	>	* @throws IllegalStateException if the computation detectably
2625	>	*         attempts a recursive update to this map that would
2626	>	*         otherwise never complete
2627	>	* @throws RuntimeException or Error if the mappingFunction does so,
2628	>	*         in which case the mapping is left unestablished
2629		*/
2630	<	public V remove(Object key) {
2631	<	int hash = hash(key);
2632	<	return segmentFor(hash).remove(key, hash, null);
2630	>	public V computeIfAbsent
2631	>	(K key, Function<? super K, ? extends V> mappingFunction) {
2632	>	return internalComputeIfAbsent(key, mappingFunction);
2633		}
2634
2635		/**
2636	<	* Remove entry for key only if currently mapped to given value.
2637	<	* Acts as
2638	<	* <pre>
2639	<	*  if (map.get(key).equals(value)) {
2640	<	*     map.remove(key);
2641	<	*     return true;
2642	<	* } else return false;
2643	<	* </pre>
2644	<	* except that the action is performed atomically.
2645	<	* @param key key with which the specified value is associated.
2646	<	* @param value value associated with the specified key.
2647	<	* @return true if the value was removed
2648	<	* @throws NullPointerException if the specified key is
2649	<	*            <tt>null</tt>.
2636	>	* If the value for the specified key is present and non-null,
2637	>	* attempts to compute a new mapping given the key and its current
2638	>	* mapped value.  The entire method invocation is performed
2639	>	* atomically.  Some attempted update operations on this map by
2640	>	* other threads may be blocked while computation is in progress,
2641	>	* so the computation should be short and simple, and must not
2642	>	* attempt to update any other mappings of this Map.
2643	>	*
2644	>	* @param key key with which the specified value is to be associated
2645	>	* @param remappingFunction the function to compute a value
2646	>	* @return the new value associated with the specified key, or null if none
2647	>	* @throws NullPointerException if the specified key or remappingFunction
2648	>	*         is null
2649	>	* @throws IllegalStateException if the computation detectably
2650	>	*         attempts a recursive update to this map that would
2651	>	*         otherwise never complete
2652	>	* @throws RuntimeException or Error if the remappingFunction does so,
2653	>	*         in which case the mapping is unchanged
2654		*/
2655	<	public boolean remove(Object key, Object value) {
2656	<	int hash = hash(key);
2657	<	return segmentFor(hash).remove(key, hash, value) != null;
2655	>	public V computeIfPresent
2656	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2657	>	return internalCompute(key, true, remappingFunction);
2658		}
2659
2660		/**
2661	<	* Removes all mappings from this map.
2661	>	* Attempts to compute a mapping for the specified key and its
2662	>	* current mapped value (or {@code null} if there is no current
2663	>	* mapping). The entire method invocation is performed atomically.
2664	>	* Some attempted update operations on this map by other threads
2665	>	* may be blocked while computation is in progress, so the
2666	>	* computation should be short and simple, and must not attempt to
2667	>	* update any other mappings of this Map.
2668	>	*
2669	>	* @param key key with which the specified value is to be associated
2670	>	* @param remappingFunction the function to compute a value
2671	>	* @return the new value associated with the specified key, or null if none
2672	>	* @throws NullPointerException if the specified key or remappingFunction
2673	>	*         is null
2674	>	* @throws IllegalStateException if the computation detectably
2675	>	*         attempts a recursive update to this map that would
2676	>	*         otherwise never complete
2677	>	* @throws RuntimeException or Error if the remappingFunction does so,
2678	>	*         in which case the mapping is unchanged
2679		*/
2680	<	public void clear() {
2681	<	for (int i = 0; i < segments.length; ++i)
2682	<	segments[i].clear();
2680	>	public V compute
2681	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2682	>	return internalCompute(key, false, remappingFunction);
2683		}
2684
2685	+	/**
2686	+	* If the specified key is not already associated with a
2687	+	* (non-null) value, associates it with the given value.
2688	+	* Otherwise, replaces the value with the results of the given
2689	+	* remapping function, or removes if {@code null}. The entire
2690	+	* method invocation is performed atomically.  Some attempted
2691	+	* update operations on this map by other threads may be blocked
2692	+	* while computation is in progress, so the computation should be
2693	+	* short and simple, and must not attempt to update any other
2694	+	* mappings of this Map.
2695	+	*
2696	+	* @param key key with which the specified value is to be associated
2697	+	* @param value the value to use if absent
2698	+	* @param remappingFunction the function to recompute a value if present
2699	+	* @return the new value associated with the specified key, or null if none
2700	+	* @throws NullPointerException if the specified key or the
2701	+	*         remappingFunction is null
2702	+	* @throws RuntimeException or Error if the remappingFunction does so,
2703	+	*         in which case the mapping is unchanged
2704	+	*/
2705	+	public V merge
2706	+	(K key, V value,
2707	+	BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2708	+	return internalMerge(key, value, remappingFunction);
2709	+	}
2710
2711		/**
2712	<	* Returns a shallow copy of this
2713	<	* <tt>ConcurrentHashMap</tt> instance: the keys and
838	<	* values themselves are not cloned.
2712	>	* Removes the key (and its corresponding value) from this map.
2713	>	* This method does nothing if the key is not in the map.
2714		*
2715	<	* @return a shallow copy of this map.
2715	>	* @param  key the key that needs to be removed
2716	>	* @return the previous value associated with {@code key}, or
2717	>	*         {@code null} if there was no mapping for {@code key}
2718	>	* @throws NullPointerException if the specified key is null
2719		*/
2720	<	public Object clone() {
2721	<	// We cannot call super.clone, since it would share final
2722	<	// segments array, and there's no way to reassign finals.
2720	>	public V remove(Object key) {
2721	>	return internalReplace(key, null, null);
2722	>	}
2723
2724	<	float lf = segments[0].loadFactor;
2725	<	int segs = segments.length;
2726	<	int cap = (int)(size() / lf);
2727	<	if (cap < segs) cap = segs;
2728	<	ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
2729	<	t.putAll(this);
2730	<	return t;
2724	>	/**
2725	>	* {@inheritDoc}
2726	>	*
2727	>	* @throws NullPointerException if the specified key is null
2728	>	*/
2729	>	public boolean remove(Object key, Object value) {
2730	>	return value != null && internalReplace(key, null, value) != null;
2731		}
2732
2733		/**
2734	<	* Returns a set view of the keys contained in this map.  The set is
857	<	* backed by the map, so changes to the map are reflected in the set, and
858	<	* vice-versa.  The set supports element removal, which removes the
859	<	* corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
860	<	* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
861	<	* <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
862	<	* <tt>addAll</tt> operations.
863	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
864	<	* will never throw {@link java.util.ConcurrentModificationException},
865	<	* and guarantees to traverse elements as they existed upon
866	<	* construction of the iterator, and may (but is not guaranteed to)
867	<	* reflect any modifications subsequent to construction.
2734	>	* {@inheritDoc}
2735		*
2736	<	* @return a set view of the keys contained in this map.
2736	>	* @throws NullPointerException if any of the arguments are null
2737		*/
2738	<	public Set<K> keySet() {
2739	<	Set<K> ks = keySet;
2740	<	return (ks != null) ? ks : (keySet = new KeySet());
2738	>	public boolean replace(K key, V oldValue, V newValue) {
2739	>	if (key == null || oldValue == null || newValue == null)
2740	>	throw new NullPointerException();
2741	>	return internalReplace(key, newValue, oldValue) != null;
2742		}
2743
2744	+	/**
2745	+	* {@inheritDoc}
2746	+	*
2747	+	* @return the previous value associated with the specified key,
2748	+	*         or {@code null} if there was no mapping for the key
2749	+	* @throws NullPointerException if the specified key or value is null
2750	+	*/
2751	+	public V replace(K key, V value) {
2752	+	if (key == null || value == null)
2753	+	throw new NullPointerException();
2754	+	return internalReplace(key, value, null);
2755	+	}
2756
2757		/**
2758	<	* Returns a collection view of the values contained in this map.  The
2759	<	* collection is backed by the map, so changes to the map are reflected in
2760	<	* the collection, and vice-versa.  The collection supports element
2761	<	* removal, which removes the corresponding mapping from this map, via the
2762	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
2763	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
2764	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
2765	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
2766	<	* will never throw {@link java.util.ConcurrentModificationException},
2767	<	* and guarantees to traverse elements as they existed upon
888	<	* construction of the iterator, and may (but is not guaranteed to)
889	<	* reflect any modifications subsequent to construction.
2758	>	* Removes all of the mappings from this map.
2759	>	*/
2760	>	public void clear() {
2761	>	internalClear();
2762	>	}
2763	>
2764	>	/**
2765	>	* Returns a {@link Set} view of the keys contained in this map.
2766	>	* The set is backed by the map, so changes to the map are
2767	>	* reflected in the set, and vice-versa.
2768		*
2769	<	* @return a collection view of the values contained in this map.
2769	>	* @return the set view
2770		*/
2771	<	public Collection<V> values() {
2772	<	Collection<V> vs = values;
2773	<	return (vs != null) ? vs : (values = new Values());
2771	>	public KeySetView<K,V> keySet() {
2772	>	KeySetView<K,V> ks = keySet;
2773	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2774		}
2775
2776	+	/**
2777	+	* Returns a {@link Set} view of the keys in this map, using the
2778	+	* given common mapped value for any additions (i.e., {@link
2779	+	* Collection#add} and {@link Collection#addAll}). This is of
2780	+	* course only appropriate if it is acceptable to use the same
2781	+	* value for all additions from this view.
2782	+	*
2783	+	* @param mappedValue the mapped value to use for any
2784	+	* additions.
2785	+	* @return the set view
2786	+	* @throws NullPointerException if the mappedValue is null
2787	+	*/
2788	+	public KeySetView<K,V> keySet(V mappedValue) {
2789	+	if (mappedValue == null)
2790	+	throw new NullPointerException();
2791	+	return new KeySetView<K,V>(this, mappedValue);
2792	+	}
2793
2794		/**
2795	<	* Returns a collection view of the mappings contained in this map.  Each
2796	<	* element in the returned collection is a <tt>Map.Entry</tt>.  The
2797	<	* collection is backed by the map, so changes to the map are reflected in
2798	<	* the collection, and vice-versa.  The collection supports element
2799	<	* removal, which removes the corresponding mapping from the map, via the
2800	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
2801	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
2802	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
2803	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
2804	<	* will never throw {@link java.util.ConcurrentModificationException},
2795	>	* Returns a {@link Collection} view of the values contained in this map.
2796	>	* The collection is backed by the map, so changes to the map are
2797	>	* reflected in the collection, and vice-versa.
2798	>	*/
2799	>	public ValuesView<K,V> values() {
2800	>	ValuesView<K,V> vs = values;
2801	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2802	>	}
2803	>
2804	>	/**
2805	>	* Returns a {@link Set} view of the mappings contained in this map.
2806	>	* The set is backed by the map, so changes to the map are
2807	>	* reflected in the set, and vice-versa.  The set supports element
2808	>	* removal, which removes the corresponding mapping from the map,
2809	>	* via the {@code Iterator.remove}, {@code Set.remove},
2810	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2811	>	* operations.  It does not support the {@code add} or
2812	>	* {@code addAll} operations.
2813	>	*
2814	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2815	>	* that will never throw {@link ConcurrentModificationException},
2816		* and guarantees to traverse elements as they existed upon
2817		* construction of the iterator, and may (but is not guaranteed to)
2818		* reflect any modifications subsequent to construction.
913	–	*
914	–	* @return a collection view of the mappings contained in this map.
2819		*/
2820		public Set<Map.Entry<K,V>> entrySet() {
2821	<	Set<Map.Entry<K,V>> es = entrySet;
2822	<	return (es != null) ? es : (entrySet = (Set<Map.Entry<K,V>>) (Set) new EntrySet());
2821	>	EntrySetView<K,V> es = entrySet;
2822	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2823		}
2824
921	–
2825		/**
2826		* Returns an enumeration of the keys in this table.
2827		*
2828	<	* @return  an enumeration of the keys in this table.
2829	<	* @see     #keySet
2828	>	* @return an enumeration of the keys in this table
2829	>	* @see #keySet()
2830		*/
2831		public Enumeration<K> keys() {
2832	<	return new KeyIterator();
2832	>	return new KeyIterator<K,V>(this);
2833		}
2834
2835		/**
2836		* Returns an enumeration of the values in this table.
934	–	* Use the Enumeration methods on the returned object to fetch the elements
935	–	* sequentially.
2837		*
2838	<	* @return  an enumeration of the values in this table.
2839	<	* @see     #values
2838	>	* @return an enumeration of the values in this table
2839	>	* @see #values()
2840		*/
2841		public Enumeration<V> elements() {
2842	<	return new ValueIterator();
2842	>	return new ValueIterator<K,V>(this);
2843	>	}
2844	>
2845	>	/**
2846	>	* Returns the hash code value for this {@link Map}, i.e.,
2847	>	* the sum of, for each key-value pair in the map,
2848	>	* {@code key.hashCode() ^ value.hashCode()}.
2849	>	*
2850	>	* @return the hash code value for this map
2851	>	*/
2852	>	public int hashCode() {
2853	>	int h = 0;
2854	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2855	>	V v;
2856	>	while ((v = it.advance()) != null) {
2857	>	h += it.nextKey.hashCode() ^ v.hashCode();
2858	>	}
2859	>	return h;
2860		}
2861
2862	<	/* ---------------- Iterator Support -------------- */
2862	>	/**
2863	>	* Returns a string representation of this map.  The string
2864	>	* representation consists of a list of key-value mappings (in no
2865	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
2866	>	* mappings are separated by the characters {@code ", "} (comma
2867	>	* and space).  Each key-value mapping is rendered as the key
2868	>	* followed by an equals sign ("{@code =}") followed by the
2869	>	* associated value.
2870	>	*
2871	>	* @return a string representation of this map
2872	>	*/
2873	>	public String toString() {
2874	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2875	>	StringBuilder sb = new StringBuilder();
2876	>	sb.append('{');
2877	>	V v;
2878	>	if ((v = it.advance()) != null) {
2879	>	for (;;) {
2880	>	Object k = it.nextKey;
2881	>	sb.append(k == this ? "(this Map)" : k);
2882	>	sb.append('=');
2883	>	sb.append(v == this ? "(this Map)" : v);
2884	>	if ((v = it.advance()) == null)
2885	>	break;
2886	>	sb.append(',').append(' ');
2887	>	}
2888	>	}
2889	>	return sb.append('}').toString();
2890	>	}
2891	>
2892	>	/**
2893	>	* Compares the specified object with this map for equality.
2894	>	* Returns {@code true} if the given object is a map with the same
2895	>	* mappings as this map.  This operation may return misleading
2896	>	* results if either map is concurrently modified during execution
2897	>	* of this method.
2898	>	*
2899	>	* @param o object to be compared for equality with this map
2900	>	* @return {@code true} if the specified object is equal to this map
2901	>	*/
2902	>	public boolean equals(Object o) {
2903	>	if (o != this) {
2904	>	if (!(o instanceof Map))
2905	>	return false;
2906	>	Map<?,?> m = (Map<?,?>) o;
2907	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2908	>	V val;
2909	>	while ((val = it.advance()) != null) {
2910	>	Object v = m.get(it.nextKey);
2911	>	if (v == null || (v != val && !v.equals(val)))
2912	>	return false;
2913	>	}
2914	>	for (Map.Entry<?,?> e : m.entrySet()) {
2915	>	Object mk, mv, v;
2916	>	if ((mk = e.getKey()) == null ||
2917	>	(mv = e.getValue()) == null ||
2918	>	(v = internalGet(mk)) == null ||
2919	>	(mv != v && !mv.equals(v)))
2920	>	return false;
2921	>	}
2922	>	}
2923	>	return true;
2924	>	}
2925
2926	<	private abstract class HashIterator {
947	<	private int nextSegmentIndex;
948	<	private int nextTableIndex;
949	<	private HashEntry[] currentTable;
950	<	private HashEntry<K, V> nextEntry;
951	<	private HashEntry<K, V> lastReturned;
2926	>	/* ----------------Iterators -------------- */
2927
2928	<	private HashIterator() {
2929	<	nextSegmentIndex = segments.length - 1;
2930	<	nextTableIndex = -1;
2931	<	advance();
2928	>	@SuppressWarnings("serial") static final class KeyIterator<K,V>
2929	>	extends Traverser<K,V,Object>
2930	>	implements Spliterator<K>, Iterator<K>, Enumeration<K> {
2931	>	KeyIterator(ConcurrentHashMap<K, V> map) { super(map); }
2932	>	KeyIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
2933	>	super(map, it);
2934	>	}
2935	>	public KeyIterator<K,V> trySplit() {
2936	>	if (tab != null && baseIndex == baseLimit)
2937	>	return null;
2938	>	return new KeyIterator<K,V>(map, this);
2939	>	}
2940	>	@SuppressWarnings("unchecked") public final K next() {
2941	>	if (nextVal == null && advance() == null)
2942	>	throw new NoSuchElementException();
2943	>	Object k = nextKey;
2944	>	nextVal = null;
2945	>	return (K) k;
2946		}
2947
2948	<	public boolean hasMoreElements() { return hasNext(); }
2948	>	public final K nextElement() { return next(); }
2949
2950	<	private void advance() {
962	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
963	<	return;
2950	>	public Iterator<K> iterator() { return this; }
2951
2952	<	while (nextTableIndex >= 0) {
2953	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
2954	<	return;
2955	<	}
2952	>	public void forEach(Block<? super K> action) {
2953	>	if (action == null) throw new NullPointerException();
2954	>	while (advance() != null)
2955	>	action.accept((K)nextKey);
2956	>	}
2957	>
2958	>	public boolean tryAdvance(Block<? super K> block) {
2959	>	if (block == null) throw new NullPointerException();
2960	>	if (advance() == null)
2961	>	return false;
2962	>	block.accept((K)nextKey);
2963	>	return true;
2964	>	}
2965	>	}
2966	>
2967	>	@SuppressWarnings("serial") static final class ValueIterator<K,V>
2968	>	extends Traverser<K,V,Object>
2969	>	implements Spliterator<V>, Iterator<V>, Enumeration<V> {
2970	>	ValueIterator(ConcurrentHashMap<K, V> map) { super(map); }
2971	>	ValueIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
2972	>	super(map, it);
2973	>	}
2974	>	public ValueIterator<K,V> trySplit() {
2975	>	if (tab != null && baseIndex == baseLimit)
2976	>	return null;
2977	>	return new ValueIterator<K,V>(map, this);
2978	>	}
2979	>
2980	>	public final V next() {
2981	>	V v;
2982	>	if ((v = nextVal) == null && (v = advance()) == null)
2983	>	throw new NoSuchElementException();
2984	>	nextVal = null;
2985	>	return v;
2986	>	}
2987	>
2988	>	public final V nextElement() { return next(); }
2989	>
2990	>	public Iterator<V> iterator() { return this; }
2991	>
2992	>	public void forEach(Block<? super V> action) {
2993	>	if (action == null) throw new NullPointerException();
2994	>	V v;
2995	>	while ((v = advance()) != null)
2996	>	action.accept(v);
2997	>	}
2998	>
2999	>	public boolean tryAdvance(Block<? super V> block) {
3000	>	V v;
3001	>	if (block == null) throw new NullPointerException();
3002	>	if ((v = advance()) == null)
3003	>	return false;
3004	>	block.accept(v);
3005	>	return true;
3006	>	}
3007	>
3008	>	}
3009	>
3010	>	@SuppressWarnings("serial") static final class EntryIterator<K,V>
3011	>	extends Traverser<K,V,Object>
3012	>	implements Spliterator<Map.Entry<K,V>>, Iterator<Map.Entry<K,V>> {
3013	>	EntryIterator(ConcurrentHashMap<K, V> map) { super(map); }
3014	>	EntryIterator(ConcurrentHashMap<K, V> map, Traverser<K,V,Object> it) {
3015	>	super(map, it);
3016	>	}
3017	>	public EntryIterator<K,V> trySplit() {
3018	>	if (tab != null && baseIndex == baseLimit)
3019	>	return null;
3020	>	return new EntryIterator<K,V>(map, this);
3021	>	}
3022	>
3023	>	@SuppressWarnings("unchecked") public final Map.Entry<K,V> next() {
3024	>	V v;
3025	>	if ((v = nextVal) == null && (v = advance()) == null)
3026	>	throw new NoSuchElementException();
3027	>	Object k = nextKey;
3028	>	nextVal = null;
3029	>	return new MapEntry<K,V>((K)k, v, map);
3030	>	}
3031	>
3032	>	public Iterator<Map.Entry<K,V>> iterator() { return this; }
3033	>
3034	>	public void forEach(Block<? super Map.Entry<K,V>> action) {
3035	>	if (action == null) throw new NullPointerException();
3036	>	V v;
3037	>	while ((v = advance()) != null)
3038	>	action.accept(entryFor((K)nextKey, v));
3039	>	}
3040	>
3041	>	public boolean tryAdvance(Block<? super Map.Entry<K,V>> block) {
3042	>	V v;
3043	>	if (block == null) throw new NullPointerException();
3044	>	if ((v = advance()) == null)
3045	>	return false;
3046	>	block.accept(entryFor((K)nextKey, v));
3047	>	return true;
3048	>	}
3049	>
3050	>	}
3051	>
3052	>	/**
3053	>	* Exported Entry for iterators
3054	>	*/
3055	>	static final class MapEntry<K,V> implements Map.Entry<K, V> {
3056	>	final K key; // non-null
3057	>	V val;       // non-null
3058	>	final ConcurrentHashMap<K, V> map;
3059	>	MapEntry(K key, V val, ConcurrentHashMap<K, V> map) {
3060	>	this.key = key;
3061	>	this.val = val;
3062	>	this.map = map;
3063	>	}
3064	>	public final K getKey()       { return key; }
3065	>	public final V getValue()     { return val; }
3066	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3067	>	public final String toString(){ return key + "=" + val; }
3068	>
3069	>	public final boolean equals(Object o) {
3070	>	Object k, v; Map.Entry<?,?> e;
3071	>	return ((o instanceof Map.Entry) &&
3072	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3073	>	(v = e.getValue()) != null &&
3074	>	(k == key || k.equals(key)) &&
3075	>	(v == val || v.equals(val)));
3076	>	}
3077	>
3078	>	/**
3079	>	* Sets our entry's value and writes through to the map. The
3080	>	* value to return is somewhat arbitrary here. Since we do not
3081	>	* necessarily track asynchronous changes, the most recent
3082	>	* "previous" value could be different from what we return (or
3083	>	* could even have been removed in which case the put will
3084	>	* re-establish). We do not and cannot guarantee more.
3085	>	*/
3086	>	public final V setValue(V value) {
3087	>	if (value == null) throw new NullPointerException();
3088	>	V v = val;
3089	>	val = value;
3090	>	map.put(key, value);
3091	>	return v;
3092	>	}
3093	>	}
3094	>
3095	>	/**
3096	>	* Returns exportable snapshot entry for the given key and value
3097	>	* when write-through can't or shouldn't be used.
3098	>	*/
3099	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3100	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
3101	>	}
3102	>
3103	>	/* ---------------- Serialization Support -------------- */
3104	>
3105	>	/**
3106	>	* Stripped-down version of helper class used in previous version,
3107	>	* declared for the sake of serialization compatibility
3108	>	*/
3109	>	static class Segment<K,V> implements Serializable {
3110	>	private static final long serialVersionUID = 2249069246763182397L;
3111	>	final float loadFactor;
3112	>	Segment(float lf) { this.loadFactor = lf; }
3113	>	}
3114	>
3115	>	/**
3116	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3117	>	* stream (i.e., serializes it).
3118	>	* @param s the stream
3119	>	* @serialData
3120	>	* the key (Object) and value (Object)
3121	>	* for each key-value mapping, followed by a null pair.
3122	>	* The key-value mappings are emitted in no particular order.
3123	>	*/
3124	>	@SuppressWarnings("unchecked") private void writeObject
3125	>	(java.io.ObjectOutputStream s)
3126	>	throws java.io.IOException {
3127	>	if (segments == null) { // for serialization compatibility
3128	>	segments = (Segment<K,V>[])
3129	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3130	>	for (int i = 0; i < segments.length; ++i)
3131	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3132	>	}
3133	>	s.defaultWriteObject();
3134	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3135	>	V v;
3136	>	while ((v = it.advance()) != null) {
3137	>	s.writeObject(it.nextKey);
3138	>	s.writeObject(v);
3139	>	}
3140	>	s.writeObject(null);
3141	>	s.writeObject(null);
3142	>	segments = null; // throw away
3143	>	}
3144	>
3145	>	/**
3146	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3147	>	* @param s the stream
3148	>	*/
3149	>	@SuppressWarnings("unchecked") private void readObject
3150	>	(java.io.ObjectInputStream s)
3151	>	throws java.io.IOException, ClassNotFoundException {
3152	>	s.defaultReadObject();
3153	>	this.segments = null; // unneeded
3154
3155	<	while (nextSegmentIndex >= 0) {
3156	<	Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
3157	<	if (seg.count != 0) {
3158	<	currentTable = seg.table;
3159	<	for (int j = currentTable.length - 1; j >= 0; --j) {
3160	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
3161	<	nextTableIndex = j - 1;
3162	<	return;
3155	>	// Create all nodes, then place in table once size is known
3156	>	long size = 0L;
3157	>	Node<V> p = null;
3158	>	for (;;) {
3159	>	K k = (K) s.readObject();
3160	>	V v = (V) s.readObject();
3161	>	if (k != null && v != null) {
3162	>	int h = spread(k.hashCode());
3163	>	p = new Node<V>(h, k, v, p);
3164	>	++size;
3165	>	}
3166	>	else
3167	>	break;
3168	>	}
3169	>	if (p != null) {
3170	>	boolean init = false;
3171	>	int n;
3172	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3173	>	n = MAXIMUM_CAPACITY;
3174	>	else {
3175	>	int sz = (int)size;
3176	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3177	>	}
3178	>	int sc = sizeCtl;
3179	>	boolean collide = false;
3180	>	if (n > sc &&
3181	>	U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
3182	>	try {
3183	>	if (table == null) {
3184	>	init = true;
3185	>	@SuppressWarnings("rawtypes") Node[] rt = new Node[n];
3186	>	Node<V>[] tab = (Node<V>[])rt;
3187	>	int mask = n - 1;
3188	>	while (p != null) {
3189	>	int j = p.hash & mask;
3190	>	Node<V> next = p.next;
3191	>	Node<V> q = p.next = tabAt(tab, j);
3192	>	setTabAt(tab, j, p);
3193	>	if (!collide && q != null && q.hash == p.hash)
3194	>	collide = true;
3195	>	p = next;
3196	>	}
3197	>	table = tab;
3198	>	addCount(size, -1);
3199	>	sc = n - (n >>> 2);
3200	>	}
3201	>	} finally {
3202	>	sizeCtl = sc;
3203	>	}
3204	>	if (collide) { // rescan and convert to TreeBins
3205	>	Node<V>[] tab = table;
3206	>	for (int i = 0; i < tab.length; ++i) {
3207	>	int c = 0;
3208	>	for (Node<V> e = tabAt(tab, i); e != null; e = e.next) {
3209	>	if (++c > TREE_THRESHOLD &&
3210	>	(e.key instanceof Comparable)) {
3211	>	replaceWithTreeBin(tab, i, e.key);
3212	>	break;
3213	>	}
3214		}
3215		}
3216		}
3217		}
3218	+	if (!init) { // Can only happen if unsafely published.
3219	+	while (p != null) {
3220	+	internalPut((K)p.key, p.val, false);
3221	+	p = p.next;
3222	+	}
3223	+	}
3224		}
3225	+	}
3226
3227	<	public boolean hasNext() { return nextEntry != null; }
3227	>	// -------------------------------------------------------
3228
3229	<	HashEntry<K,V> nextEntry() {
3230	<	if (nextEntry == null)
3231	<	throw new NoSuchElementException();
3232	<	lastReturned = nextEntry;
3233	<	advance();
3234	<	return lastReturned;
3229	>	// Sequential bulk operations
3230	>
3231	>	/**
3232	>	* Performs the given action for each (key, value).
3233	>	*
3234	>	* @param action the action
3235	>	*/
3236	>	@SuppressWarnings("unchecked") public void forEachSequentially
3237	>	(BiBlock<? super K, ? super V> action) {
3238	>	if (action == null) throw new NullPointerException();
3239	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3240	>	V v;
3241	>	while ((v = it.advance()) != null)
3242	>	action.accept((K)it.nextKey, v);
3243	>	}
3244	>
3245	>	/**
3246	>	* Performs the given action for each non-null transformation
3247	>	* of each (key, value).
3248	>	*
3249	>	* @param transformer a function returning the transformation
3250	>	* for an element, or null of there is no transformation (in
3251	>	* which case the action is not applied).
3252	>	* @param action the action
3253	>	*/
3254	>	@SuppressWarnings("unchecked") public <U> void forEachSequentially
3255	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3256	>	Block<? super U> action) {
3257	>	if (transformer == null || action == null)
3258	>	throw new NullPointerException();
3259	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3260	>	V v; U u;
3261	>	while ((v = it.advance()) != null) {
3262	>	if ((u = transformer.apply((K)it.nextKey, v)) != null)
3263	>	action.accept(u);
3264		}
3265	+	}
3266
3267	<	public void remove() {
3268	<	if (lastReturned == null)
3269	<	throw new IllegalStateException();
3270	<	ConcurrentHashMap.this.remove(lastReturned.key);
3271	<	lastReturned = null;
3267	>	/**
3268	>	* Returns a non-null result from applying the given search
3269	>	* function on each (key, value), or null if none.
3270	>	*
3271	>	* @param searchFunction a function returning a non-null
3272	>	* result on success, else null
3273	>	* @return a non-null result from applying the given search
3274	>	* function on each (key, value), or null if none
3275	>	*/
3276	>	@SuppressWarnings("unchecked") public <U> U searchSequentially
3277	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3278	>	if (searchFunction == null) throw new NullPointerException();
3279	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3280	>	V v; U u;
3281	>	while ((v = it.advance()) != null) {
3282	>	if ((u = searchFunction.apply((K)it.nextKey, v)) != null)
3283	>	return u;
3284		}
3285	+	return null;
3286		}
3287
3288	<	private class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
3289	<	public K next() { return super.nextEntry().key; }
3290	<	public K nextElement() { return super.nextEntry().key; }
3288	>	/**
3289	>	* Returns the result of accumulating the given transformation
3290	>	* of all (key, value) pairs using the given reducer to
3291	>	* combine values, or null if none.
3292	>	*
3293	>	* @param transformer a function returning the transformation
3294	>	* for an element, or null of there is no transformation (in
3295	>	* which case it is not combined).
3296	>	* @param reducer a commutative associative combining function
3297	>	* @return the result of accumulating the given transformation
3298	>	* of all (key, value) pairs
3299	>	*/
3300	>	@SuppressWarnings("unchecked") public <U> U reduceSequentially
3301	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3302	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3303	>	if (transformer == null || reducer == null)
3304	>	throw new NullPointerException();
3305	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3306	>	U r = null, u; V v;
3307	>	while ((v = it.advance()) != null) {
3308	>	if ((u = transformer.apply((K)it.nextKey, v)) != null)
3309	>	r = (r == null) ? u : reducer.apply(r, u);
3310	>	}
3311	>	return r;
3312		}
3313
3314	<	private class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
3315	<	public V next() { return super.nextEntry().value; }
3316	<	public V nextElement() { return super.nextEntry().value; }
3314	>	/**
3315	>	* Returns the result of accumulating the given transformation
3316	>	* of all (key, value) pairs using the given reducer to
3317	>	* combine values, and the given basis as an identity value.
3318	>	*
3319	>	* @param transformer a function returning the transformation
3320	>	* for an element
3321	>	* @param basis the identity (initial default value) for the reduction
3322	>	* @param reducer a commutative associative combining function
3323	>	* @return the result of accumulating the given transformation
3324	>	* of all (key, value) pairs
3325	>	*/
3326	>	@SuppressWarnings("unchecked") public double reduceToDoubleSequentially
3327	>	(DoubleBiFunction<? super K, ? super V> transformer,
3328	>	double basis,
3329	>	DoubleBinaryOperator reducer) {
3330	>	if (transformer == null || reducer == null)
3331	>	throw new NullPointerException();
3332	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3333	>	double r = basis; V v;
3334	>	while ((v = it.advance()) != null)
3335	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)it.nextKey, v));
3336	>	return r;
3337		}
3338
3339	<	private class EntryIterator extends HashIterator implements Iterator<Entry<K,V>> {
3340	<	public Map.Entry<K,V> next() { return super.nextEntry(); }
3339	>	/**
3340	>	* Returns the result of accumulating the given transformation
3341	>	* of all (key, value) pairs using the given reducer to
3342	>	* combine values, and the given basis as an identity value.
3343	>	*
3344	>	* @param transformer a function returning the transformation
3345	>	* for an element
3346	>	* @param basis the identity (initial default value) for the reduction
3347	>	* @param reducer a commutative associative combining function
3348	>	* @return the result of accumulating the given transformation
3349	>	* of all (key, value) pairs
3350	>	*/
3351	>	@SuppressWarnings("unchecked") public long reduceToLongSequentially
3352	>	(LongBiFunction<? super K, ? super V> transformer,
3353	>	long basis,
3354	>	LongBinaryOperator reducer) {
3355	>	if (transformer == null || reducer == null)
3356	>	throw new NullPointerException();
3357	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3358	>	long r = basis; V v;
3359	>	while ((v = it.advance()) != null)
3360	>	r = reducer.applyAsLong(r, transformer.applyAsLong((K)it.nextKey, v));
3361	>	return r;
3362	>	}
3363	>
3364	>	/**
3365	>	* Returns the result of accumulating the given transformation
3366	>	* of all (key, value) pairs using the given reducer to
3367	>	* combine values, and the given basis as an identity value.
3368	>	*
3369	>	* @param transformer a function returning the transformation
3370	>	* for an element
3371	>	* @param basis the identity (initial default value) for the reduction
3372	>	* @param reducer a commutative associative combining function
3373	>	* @return the result of accumulating the given transformation
3374	>	* of all (key, value) pairs
3375	>	*/
3376	>	@SuppressWarnings("unchecked") public int reduceToIntSequentially
3377	>	(IntBiFunction<? super K, ? super V> transformer,
3378	>	int basis,
3379	>	IntBinaryOperator reducer) {
3380	>	if (transformer == null || reducer == null)
3381	>	throw new NullPointerException();
3382	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3383	>	int r = basis; V v;
3384	>	while ((v = it.advance()) != null)
3385	>	r = reducer.applyAsInt(r, transformer.applyAsInt((K)it.nextKey, v));
3386	>	return r;
3387	>	}
3388	>
3389	>	/**
3390	>	* Performs the given action for each key.
3391	>	*
3392	>	* @param action the action
3393	>	*/
3394	>	@SuppressWarnings("unchecked") public void forEachKeySequentially
3395	>	(Block<? super K> action) {
3396	>	if (action == null) throw new NullPointerException();
3397	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3398	>	while (it.advance() != null)
3399	>	action.accept((K)it.nextKey);
3400	>	}
3401	>
3402	>	/**
3403	>	* Performs the given action for each non-null transformation
3404	>	* of each key.
3405	>	*
3406	>	* @param transformer a function returning the transformation
3407	>	* for an element, or null of there is no transformation (in
3408	>	* which case the action is not applied).
3409	>	* @param action the action
3410	>	*/
3411	>	@SuppressWarnings("unchecked") public <U> void forEachKeySequentially
3412	>	(Function<? super K, ? extends U> transformer,
3413	>	Block<? super U> action) {
3414	>	if (transformer == null || action == null)
3415	>	throw new NullPointerException();
3416	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3417	>	U u;
3418	>	while (it.advance() != null) {
3419	>	if ((u = transformer.apply((K)it.nextKey)) != null)
3420	>	action.accept(u);
3421	>	}
3422	>	ForkJoinTasks.forEachKey
3423	>	(this, transformer, action).invoke();
3424	>	}
3425	>
3426	>	/**
3427	>	* Returns a non-null result from applying the given search
3428	>	* function on each key, or null if none.
3429	>	*
3430	>	* @param searchFunction a function returning a non-null
3431	>	* result on success, else null
3432	>	* @return a non-null result from applying the given search
3433	>	* function on each key, or null if none
3434	>	*/
3435	>	@SuppressWarnings("unchecked") public <U> U searchKeysSequentially
3436	>	(Function<? super K, ? extends U> searchFunction) {
3437	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3438	>	U u;
3439	>	while (it.advance() != null) {
3440	>	if ((u = searchFunction.apply((K)it.nextKey)) != null)
3441	>	return u;
3442	>	}
3443	>	return null;
3444		}
3445
3446	<	private class KeySet extends AbstractSet<K> {
3447	<	public Iterator<K> iterator() {
3448	<	return new KeyIterator();
3446	>	/**
3447	>	* Returns the result of accumulating all keys using the given
3448	>	* reducer to combine values, or null if none.
3449	>	*
3450	>	* @param reducer a commutative associative combining function
3451	>	* @return the result of accumulating all keys using the given
3452	>	* reducer to combine values, or null if none
3453	>	*/
3454	>	@SuppressWarnings("unchecked") public K reduceKeysSequentially
3455	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
3456	>	if (reducer == null) throw new NullPointerException();
3457	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3458	>	K r = null;
3459	>	while (it.advance() != null) {
3460	>	K u = (K)it.nextKey;
3461	>	r = (r == null) ? u : reducer.apply(r, u);
3462		}
3463	<	public int size() {
3464	<	return ConcurrentHashMap.this.size();
3463	>	return r;
3464	>	}
3465	>
3466	>	/**
3467	>	* Returns the result of accumulating the given transformation
3468	>	* of all keys using the given reducer to combine values, or
3469	>	* null if none.
3470	>	*
3471	>	* @param transformer a function returning the transformation
3472	>	* for an element, or null of there is no transformation (in
3473	>	* which case it is not combined).
3474	>	* @param reducer a commutative associative combining function
3475	>	* @return the result of accumulating the given transformation
3476	>	* of all keys
3477	>	*/
3478	>	@SuppressWarnings("unchecked") public <U> U reduceKeysSequentially
3479	>	(Function<? super K, ? extends U> transformer,
3480	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3481	>	if (transformer == null || reducer == null)
3482	>	throw new NullPointerException();
3483	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3484	>	U r = null, u;
3485	>	while (it.advance() != null) {
3486	>	if ((u = transformer.apply((K)it.nextKey)) != null)
3487	>	r = (r == null) ? u : reducer.apply(r, u);
3488		}
3489	<	public boolean contains(Object o) {
3490	<	return ConcurrentHashMap.this.containsKey(o);
3489	>	return r;
3490	>	}
3491	>
3492	>	/**
3493	>	* Returns the result of accumulating the given transformation
3494	>	* of all keys using the given reducer to combine values, and
3495	>	* the given basis as an identity value.
3496	>	*
3497	>	* @param transformer a function returning the transformation
3498	>	* for an element
3499	>	* @param basis the identity (initial default value) for the reduction
3500	>	* @param reducer a commutative associative combining function
3501	>	* @return the result of accumulating the given transformation
3502	>	* of all keys
3503	>	*/
3504	>	@SuppressWarnings("unchecked") public double reduceKeysToDoubleSequentially
3505	>	(DoubleFunction<? super K> transformer,
3506	>	double basis,
3507	>	DoubleBinaryOperator reducer) {
3508	>	if (transformer == null || reducer == null)
3509	>	throw new NullPointerException();
3510	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3511	>	double r = basis;
3512	>	while (it.advance() != null)
3513	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)it.nextKey));
3514	>	return r;
3515	>	}
3516	>
3517	>	/**
3518	>	* Returns the result of accumulating the given transformation
3519	>	* of all keys using the given reducer to combine values, and
3520	>	* the given basis as an identity value.
3521	>	*
3522	>	* @param transformer a function returning the transformation
3523	>	* for an element
3524	>	* @param basis the identity (initial default value) for the reduction
3525	>	* @param reducer a commutative associative combining function
3526	>	* @return the result of accumulating the given transformation
3527	>	* of all keys
3528	>	*/
3529	>	@SuppressWarnings("unchecked") public long reduceKeysToLongSequentially
3530	>	(LongFunction<? super K> transformer,
3531	>	long basis,
3532	>	LongBinaryOperator reducer) {
3533	>	if (transformer == null || reducer == null)
3534	>	throw new NullPointerException();
3535	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3536	>	long r = basis;
3537	>	while (it.advance() != null)
3538	>	r = reducer.applyAsLong(r, transformer.applyAsLong((K)it.nextKey));
3539	>	return r;
3540	>	}
3541	>
3542	>	/**
3543	>	* Returns the result of accumulating the given transformation
3544	>	* of all keys using the given reducer to combine values, and
3545	>	* the given basis as an identity value.
3546	>	*
3547	>	* @param transformer a function returning the transformation
3548	>	* for an element
3549	>	* @param basis the identity (initial default value) for the reduction
3550	>	* @param reducer a commutative associative combining function
3551	>	* @return the result of accumulating the given transformation
3552	>	* of all keys
3553	>	*/
3554	>	@SuppressWarnings("unchecked") public int reduceKeysToIntSequentially
3555	>	(IntFunction<? super K> transformer,
3556	>	int basis,
3557	>	IntBinaryOperator reducer) {
3558	>	if (transformer == null || reducer == null)
3559	>	throw new NullPointerException();
3560	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3561	>	int r = basis;
3562	>	while (it.advance() != null)
3563	>	r = reducer.applyAsInt(r, transformer.applyAsInt((K)it.nextKey));
3564	>	return r;
3565	>	}
3566	>
3567	>	/**
3568	>	* Performs the given action for each value.
3569	>	*
3570	>	* @param action the action
3571	>	*/
3572	>	public void forEachValueSequentially(Block<? super V> action) {
3573	>	if (action == null) throw new NullPointerException();
3574	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3575	>	V v;
3576	>	while ((v = it.advance()) != null)
3577	>	action.accept(v);
3578	>	}
3579	>
3580	>	/**
3581	>	* Performs the given action for each non-null transformation
3582	>	* of each value.
3583	>	*
3584	>	* @param transformer a function returning the transformation
3585	>	* for an element, or null of there is no transformation (in
3586	>	* which case the action is not applied).
3587	>	*/
3588	>	public <U> void forEachValueSequentially
3589	>	(Function<? super V, ? extends U> transformer,
3590	>	Block<? super U> action) {
3591	>	if (transformer == null || action == null)
3592	>	throw new NullPointerException();
3593	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3594	>	V v; U u;
3595	>	while ((v = it.advance()) != null) {
3596	>	if ((u = transformer.apply(v)) != null)
3597	>	action.accept(u);
3598		}
3599	<	public boolean remove(Object o) {
3600	<	return ConcurrentHashMap.this.remove(o) != null;
3599	>	}
3600	>
3601	>	/**
3602	>	* Returns a non-null result from applying the given search
3603	>	* function on each value, or null if none.
3604	>	*
3605	>	* @param searchFunction a function returning a non-null
3606	>	* result on success, else null
3607	>	* @return a non-null result from applying the given search
3608	>	* function on each value, or null if none
3609	>	*/
3610	>	public <U> U searchValuesSequentially
3611	>	(Function<? super V, ? extends U> searchFunction) {
3612	>	if (searchFunction == null) throw new NullPointerException();
3613	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3614	>	V v; U u;
3615	>	while ((v = it.advance()) != null) {
3616	>	if ((u = searchFunction.apply(v)) != null)
3617	>	return u;
3618		}
3619	<	public void clear() {
3620	<	ConcurrentHashMap.this.clear();
3619	>	return null;
3620	>	}
3621	>
3622	>	/**
3623	>	* Returns the result of accumulating all values using the
3624	>	* given reducer to combine values, or null if none.
3625	>	*
3626	>	* @param reducer a commutative associative combining function
3627	>	* @return the result of accumulating all values
3628	>	*/
3629	>	public V reduceValuesSequentially
3630	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
3631	>	if (reducer == null) throw new NullPointerException();
3632	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3633	>	V r = null; V v;
3634	>	while ((v = it.advance()) != null)
3635	>	r = (r == null) ? v : reducer.apply(r, v);
3636	>	return r;
3637	>	}
3638	>
3639	>	/**
3640	>	* Returns the result of accumulating the given transformation
3641	>	* of all values using the given reducer to combine values, or
3642	>	* null if none.
3643	>	*
3644	>	* @param transformer a function returning the transformation
3645	>	* for an element, or null of there is no transformation (in
3646	>	* which case it is not combined).
3647	>	* @param reducer a commutative associative combining function
3648	>	* @return the result of accumulating the given transformation
3649	>	* of all values
3650	>	*/
3651	>	public <U> U reduceValuesSequentially
3652	>	(Function<? super V, ? extends U> transformer,
3653	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3654	>	if (transformer == null || reducer == null)
3655	>	throw new NullPointerException();
3656	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3657	>	U r = null, u; V v;
3658	>	while ((v = it.advance()) != null) {
3659	>	if ((u = transformer.apply(v)) != null)
3660	>	r = (r == null) ? u : reducer.apply(r, u);
3661		}
3662	+	return r;
3663	+	}
3664	+
3665	+	/**
3666	+	* Returns the result of accumulating the given transformation
3667	+	* of all values using the given reducer to combine values,
3668	+	* and the given basis as an identity value.
3669	+	*
3670	+	* @param transformer a function returning the transformation
3671	+	* for an element
3672	+	* @param basis the identity (initial default value) for the reduction
3673	+	* @param reducer a commutative associative combining function
3674	+	* @return the result of accumulating the given transformation
3675	+	* of all values
3676	+	*/
3677	+	public double reduceValuesToDoubleSequentially
3678	+	(DoubleFunction<? super V> transformer,
3679	+	double basis,
3680	+	DoubleBinaryOperator reducer) {
3681	+	if (transformer == null || reducer == null)
3682	+	throw new NullPointerException();
3683	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3684	+	double r = basis; V v;
3685	+	while ((v = it.advance()) != null)
3686	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
3687	+	return r;
3688	+	}
3689	+
3690	+	/**
3691	+	* Returns the result of accumulating the given transformation
3692	+	* of all values using the given reducer to combine values,
3693	+	* and the given basis as an identity value.
3694	+	*
3695	+	* @param transformer a function returning the transformation
3696	+	* for an element
3697	+	* @param basis the identity (initial default value) for the reduction
3698	+	* @param reducer a commutative associative combining function
3699	+	* @return the result of accumulating the given transformation
3700	+	* of all values
3701	+	*/
3702	+	public long reduceValuesToLongSequentially
3703	+	(LongFunction<? super V> transformer,
3704	+	long basis,
3705	+	LongBinaryOperator reducer) {
3706	+	if (transformer == null || reducer == null)
3707	+	throw new NullPointerException();
3708	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3709	+	long r = basis; V v;
3710	+	while ((v = it.advance()) != null)
3711	+	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
3712	+	return r;
3713		}
3714
3715	<	private class Values extends AbstractCollection<V> {
3716	<	public Iterator<V> iterator() {
3717	<	return new ValueIterator();
3715	>	/**
3716	>	* Returns the result of accumulating the given transformation
3717	>	* of all values using the given reducer to combine values,
3718	>	* and the given basis as an identity value.
3719	>	*
3720	>	* @param transformer a function returning the transformation
3721	>	* for an element
3722	>	* @param basis the identity (initial default value) for the reduction
3723	>	* @param reducer a commutative associative combining function
3724	>	* @return the result of accumulating the given transformation
3725	>	* of all values
3726	>	*/
3727	>	public int reduceValuesToIntSequentially
3728	>	(IntFunction<? super V> transformer,
3729	>	int basis,
3730	>	IntBinaryOperator reducer) {
3731	>	if (transformer == null || reducer == null)
3732	>	throw new NullPointerException();
3733	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3734	>	int r = basis; V v;
3735	>	while ((v = it.advance()) != null)
3736	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
3737	>	return r;
3738	>	}
3739	>
3740	>	/**
3741	>	* Performs the given action for each entry.
3742	>	*
3743	>	* @param action the action
3744	>	*/
3745	>	@SuppressWarnings("unchecked") public void forEachEntrySequentially
3746	>	(Block<? super Map.Entry<K,V>> action) {
3747	>	if (action == null) throw new NullPointerException();
3748	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3749	>	V v;
3750	>	while ((v = it.advance()) != null)
3751	>	action.accept(entryFor((K)it.nextKey, v));
3752	>	}
3753	>
3754	>	/**
3755	>	* Performs the given action for each non-null transformation
3756	>	* of each entry.
3757	>	*
3758	>	* @param transformer a function returning the transformation
3759	>	* for an element, or null of there is no transformation (in
3760	>	* which case the action is not applied).
3761	>	* @param action the action
3762	>	*/
3763	>	@SuppressWarnings("unchecked") public <U> void forEachEntrySequentially
3764	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3765	>	Block<? super U> action) {
3766	>	if (transformer == null || action == null)
3767	>	throw new NullPointerException();
3768	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3769	>	V v; U u;
3770	>	while ((v = it.advance()) != null) {
3771	>	if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null)
3772	>	action.accept(u);
3773		}
3774	<	public int size() {
3775	<	return ConcurrentHashMap.this.size();
3774	>	}
3775	>
3776	>	/**
3777	>	* Returns a non-null result from applying the given search
3778	>	* function on each entry, or null if none.
3779	>	*
3780	>	* @param searchFunction a function returning a non-null
3781	>	* result on success, else null
3782	>	* @return a non-null result from applying the given search
3783	>	* function on each entry, or null if none
3784	>	*/
3785	>	@SuppressWarnings("unchecked") public <U> U searchEntriesSequentially
3786	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
3787	>	if (searchFunction == null) throw new NullPointerException();
3788	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3789	>	V v; U u;
3790	>	while ((v = it.advance()) != null) {
3791	>	if ((u = searchFunction.apply(entryFor((K)it.nextKey, v))) != null)
3792	>	return u;
3793		}
3794	<	public boolean contains(Object o) {
3795	<	return ConcurrentHashMap.this.containsValue(o);
3794	>	return null;
3795	>	}
3796	>
3797	>	/**
3798	>	* Returns the result of accumulating all entries using the
3799	>	* given reducer to combine values, or null if none.
3800	>	*
3801	>	* @param reducer a commutative associative combining function
3802	>	* @return the result of accumulating all entries
3803	>	*/
3804	>	@SuppressWarnings("unchecked") public Map.Entry<K,V> reduceEntriesSequentially
3805	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3806	>	if (reducer == null) throw new NullPointerException();
3807	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3808	>	Map.Entry<K,V> r = null; V v;
3809	>	while ((v = it.advance()) != null) {
3810	>	Map.Entry<K,V> u = entryFor((K)it.nextKey, v);
3811	>	r = (r == null) ? u : reducer.apply(r, u);
3812		}
3813	<	public void clear() {
3814	<	ConcurrentHashMap.this.clear();
3813	>	return r;
3814	>	}
3815	>
3816	>	/**
3817	>	* Returns the result of accumulating the given transformation
3818	>	* of all entries using the given reducer to combine values,
3819	>	* or null if none.
3820	>	*
3821	>	* @param transformer a function returning the transformation
3822	>	* for an element, or null of there is no transformation (in
3823	>	* which case it is not combined).
3824	>	* @param reducer a commutative associative combining function
3825	>	* @return the result of accumulating the given transformation
3826	>	* of all entries
3827	>	*/
3828	>	@SuppressWarnings("unchecked") public <U> U reduceEntriesSequentially
3829	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3830	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3831	>	if (transformer == null || reducer == null)
3832	>	throw new NullPointerException();
3833	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3834	>	U r = null, u; V v;
3835	>	while ((v = it.advance()) != null) {
3836	>	if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null)
3837	>	r = (r == null) ? u : reducer.apply(r, u);
3838		}
3839	+	return r;
3840	+	}
3841	+
3842	+	/**
3843	+	* Returns the result of accumulating the given transformation
3844	+	* of all entries using the given reducer to combine values,
3845	+	* and the given basis as an identity value.
3846	+	*
3847	+	* @param transformer a function returning the transformation
3848	+	* for an element
3849	+	* @param basis the identity (initial default value) for the reduction
3850	+	* @param reducer a commutative associative combining function
3851	+	* @return the result of accumulating the given transformation
3852	+	* of all entries
3853	+	*/
3854	+	@SuppressWarnings("unchecked") public double reduceEntriesToDoubleSequentially
3855	+	(DoubleFunction<Map.Entry<K,V>> transformer,
3856	+	double basis,
3857	+	DoubleBinaryOperator reducer) {
3858	+	if (transformer == null || reducer == null)
3859	+	throw new NullPointerException();
3860	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3861	+	double r = basis; V v;
3862	+	while ((v = it.advance()) != null)
3863	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor((K)it.nextKey, v)));
3864	+	return r;
3865	+	}
3866	+
3867	+	/**
3868	+	* Returns the result of accumulating the given transformation
3869	+	* of all entries using the given reducer to combine values,
3870	+	* and the given basis as an identity value.
3871	+	*
3872	+	* @param transformer a function returning the transformation
3873	+	* for an element
3874	+	* @param basis the identity (initial default value) for the reduction
3875	+	* @param reducer a commutative associative combining function
3876	+	* @return the result of accumulating the given transformation
3877	+	* of all entries
3878	+	*/
3879	+	@SuppressWarnings("unchecked") public long reduceEntriesToLongSequentially
3880	+	(LongFunction<Map.Entry<K,V>> transformer,
3881	+	long basis,
3882	+	LongBinaryOperator reducer) {
3883	+	if (transformer == null || reducer == null)
3884	+	throw new NullPointerException();
3885	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3886	+	long r = basis; V v;
3887	+	while ((v = it.advance()) != null)
3888	+	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor((K)it.nextKey, v)));
3889	+	return r;
3890	+	}
3891	+
3892	+	/**
3893	+	* Returns the result of accumulating the given transformation
3894	+	* of all entries using the given reducer to combine values,
3895	+	* and the given basis as an identity value.
3896	+	*
3897	+	* @param transformer a function returning the transformation
3898	+	* for an element
3899	+	* @param basis the identity (initial default value) for the reduction
3900	+	* @param reducer a commutative associative combining function
3901	+	* @return the result of accumulating the given transformation
3902	+	* of all entries
3903	+	*/
3904	+	@SuppressWarnings("unchecked") public int reduceEntriesToIntSequentially
3905	+	(IntFunction<Map.Entry<K,V>> transformer,
3906	+	int basis,
3907	+	IntBinaryOperator reducer) {
3908	+	if (transformer == null || reducer == null)
3909	+	throw new NullPointerException();
3910	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3911	+	int r = basis; V v;
3912	+	while ((v = it.advance()) != null)
3913	+	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor((K)it.nextKey, v)));
3914	+	return r;
3915	+	}
3916	+
3917	+	// Parallel bulk operations
3918	+
3919	+	/**
3920	+	* Performs the given action for each (key, value).
3921	+	*
3922	+	* @param action the action
3923	+	*/
3924	+	public void forEachInParallel(BiBlock<? super K,? super V> action) {
3925	+	ForkJoinTasks.forEach
3926	+	(this, action).invoke();
3927	+	}
3928	+
3929	+	/**
3930	+	* Performs the given action for each non-null transformation
3931	+	* of each (key, value).
3932	+	*
3933	+	* @param transformer a function returning the transformation
3934	+	* for an element, or null of there is no transformation (in
3935	+	* which case the action is not applied).
3936	+	* @param action the action
3937	+	*/
3938	+	public <U> void forEachInParallel
3939	+	(BiFunction<? super K, ? super V, ? extends U> transformer,
3940	+	Block<? super U> action) {
3941	+	ForkJoinTasks.forEach
3942	+	(this, transformer, action).invoke();
3943	+	}
3944	+
3945	+	/**
3946	+	* Returns a non-null result from applying the given search
3947	+	* function on each (key, value), or null if none.  Upon
3948	+	* success, further element processing is suppressed and the
3949	+	* results of any other parallel invocations of the search
3950	+	* function are ignored.
3951	+	*
3952	+	* @param searchFunction a function returning a non-null
3953	+	* result on success, else null
3954	+	* @return a non-null result from applying the given search
3955	+	* function on each (key, value), or null if none
3956	+	*/
3957	+	public <U> U searchInParallel
3958	+	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3959	+	return ForkJoinTasks.search
3960	+	(this, searchFunction).invoke();
3961	+	}
3962	+
3963	+	/**
3964	+	* Returns the result of accumulating the given transformation
3965	+	* of all (key, value) pairs using the given reducer to
3966	+	* combine values, or null if none.
3967	+	*
3968	+	* @param transformer a function returning the transformation
3969	+	* for an element, or null of there is no transformation (in
3970	+	* which case it is not combined).
3971	+	* @param reducer a commutative associative combining function
3972	+	* @return the result of accumulating the given transformation
3973	+	* of all (key, value) pairs
3974	+	*/
3975	+	public <U> U reduceInParallel
3976	+	(BiFunction<? super K, ? super V, ? extends U> transformer,
3977	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3978	+	return ForkJoinTasks.reduce
3979	+	(this, transformer, reducer).invoke();
3980	+	}
3981	+
3982	+	/**
3983	+	* Returns the result of accumulating the given transformation
3984	+	* of all (key, value) pairs using the given reducer to
3985	+	* combine values, and the given basis as an identity value.
3986	+	*
3987	+	* @param transformer a function returning the transformation
3988	+	* for an element
3989	+	* @param basis the identity (initial default value) for the reduction
3990	+	* @param reducer a commutative associative combining function
3991	+	* @return the result of accumulating the given transformation
3992	+	* of all (key, value) pairs
3993	+	*/
3994	+	public double reduceToDoubleInParallel
3995	+	(DoubleBiFunction<? super K, ? super V> transformer,
3996	+	double basis,
3997	+	DoubleBinaryOperator reducer) {
3998	+	return ForkJoinTasks.reduceToDouble
3999	+	(this, transformer, basis, reducer).invoke();
4000	+	}
4001	+
4002	+	/**
4003	+	* Returns the result of accumulating the given transformation
4004	+	* of all (key, value) pairs using the given reducer to
4005	+	* combine values, and the given basis as an identity value.
4006	+	*
4007	+	* @param transformer a function returning the transformation
4008	+	* for an element
4009	+	* @param basis the identity (initial default value) for the reduction
4010	+	* @param reducer a commutative associative combining function
4011	+	* @return the result of accumulating the given transformation
4012	+	* of all (key, value) pairs
4013	+	*/
4014	+	public long reduceToLongInParallel
4015	+	(LongBiFunction<? super K, ? super V> transformer,
4016	+	long basis,
4017	+	LongBinaryOperator reducer) {
4018	+	return ForkJoinTasks.reduceToLong
4019	+	(this, transformer, basis, reducer).invoke();
4020	+	}
4021	+
4022	+	/**
4023	+	* Returns the result of accumulating the given transformation
4024	+	* of all (key, value) pairs using the given reducer to
4025	+	* combine values, and the given basis as an identity value.
4026	+	*
4027	+	* @param transformer a function returning the transformation
4028	+	* for an element
4029	+	* @param basis the identity (initial default value) for the reduction
4030	+	* @param reducer a commutative associative combining function
4031	+	* @return the result of accumulating the given transformation
4032	+	* of all (key, value) pairs
4033	+	*/
4034	+	public int reduceToIntInParallel
4035	+	(IntBiFunction<? super K, ? super V> transformer,
4036	+	int basis,
4037	+	IntBinaryOperator reducer) {
4038	+	return ForkJoinTasks.reduceToInt
4039	+	(this, transformer, basis, reducer).invoke();
4040	+	}
4041	+
4042	+	/**
4043	+	* Performs the given action for each key.
4044	+	*
4045	+	* @param action the action
4046	+	*/
4047	+	public void forEachKeyInParallel(Block<? super K> action) {
4048	+	ForkJoinTasks.forEachKey
4049	+	(this, action).invoke();
4050	+	}
4051	+
4052	+	/**
4053	+	* Performs the given action for each non-null transformation
4054	+	* of each key.
4055	+	*
4056	+	* @param transformer a function returning the transformation
4057	+	* for an element, or null of there is no transformation (in
4058	+	* which case the action is not applied).
4059	+	* @param action the action
4060	+	*/
4061	+	public <U> void forEachKeyInParallel
4062	+	(Function<? super K, ? extends U> transformer,
4063	+	Block<? super U> action) {
4064	+	ForkJoinTasks.forEachKey
4065	+	(this, transformer, action).invoke();
4066	+	}
4067	+
4068	+	/**
4069	+	* Returns a non-null result from applying the given search
4070	+	* function on each key, or null if none. Upon success,
4071	+	* further element processing is suppressed and the results of
4072	+	* any other parallel invocations of the search function are
4073	+	* ignored.
4074	+	*
4075	+	* @param searchFunction a function returning a non-null
4076	+	* result on success, else null
4077	+	* @return a non-null result from applying the given search
4078	+	* function on each key, or null if none
4079	+	*/
4080	+	public <U> U searchKeysInParallel
4081	+	(Function<? super K, ? extends U> searchFunction) {
4082	+	return ForkJoinTasks.searchKeys
4083	+	(this, searchFunction).invoke();
4084	+	}
4085	+
4086	+	/**
4087	+	* Returns the result of accumulating all keys using the given
4088	+	* reducer to combine values, or null if none.
4089	+	*
4090	+	* @param reducer a commutative associative combining function
4091	+	* @return the result of accumulating all keys using the given
4092	+	* reducer to combine values, or null if none
4093	+	*/
4094	+	public K reduceKeysInParallel
4095	+	(BiFunction<? super K, ? super K, ? extends K> reducer) {
4096	+	return ForkJoinTasks.reduceKeys
4097	+	(this, reducer).invoke();
4098	+	}
4099	+
4100	+	/**
4101	+	* Returns the result of accumulating the given transformation
4102	+	* of all keys using the given reducer to combine values, or
4103	+	* null if none.
4104	+	*
4105	+	* @param transformer a function returning the transformation
4106	+	* for an element, or null of there is no transformation (in
4107	+	* which case it is not combined).
4108	+	* @param reducer a commutative associative combining function
4109	+	* @return the result of accumulating the given transformation
4110	+	* of all keys
4111	+	*/
4112	+	public <U> U reduceKeysInParallel
4113	+	(Function<? super K, ? extends U> transformer,
4114	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4115	+	return ForkJoinTasks.reduceKeys
4116	+	(this, transformer, reducer).invoke();
4117	+	}
4118	+
4119	+	/**
4120	+	* Returns the result of accumulating the given transformation
4121	+	* of all keys using the given reducer to combine values, and
4122	+	* the given basis as an identity value.
4123	+	*
4124	+	* @param transformer a function returning the transformation
4125	+	* for an element
4126	+	* @param basis the identity (initial default value) for the reduction
4127	+	* @param reducer a commutative associative combining function
4128	+	* @return the result of accumulating the given transformation
4129	+	* of all keys
4130	+	*/
4131	+	public double reduceKeysToDoubleInParallel
4132	+	(DoubleFunction<? super K> transformer,
4133	+	double basis,
4134	+	DoubleBinaryOperator reducer) {
4135	+	return ForkJoinTasks.reduceKeysToDouble
4136	+	(this, transformer, basis, reducer).invoke();
4137	+	}
4138	+
4139	+	/**
4140	+	* Returns the result of accumulating the given transformation
4141	+	* of all keys using the given reducer to combine values, and
4142	+	* the given basis as an identity value.
4143	+	*
4144	+	* @param transformer a function returning the transformation
4145	+	* for an element
4146	+	* @param basis the identity (initial default value) for the reduction
4147	+	* @param reducer a commutative associative combining function
4148	+	* @return the result of accumulating the given transformation
4149	+	* of all keys
4150	+	*/
4151	+	public long reduceKeysToLongInParallel
4152	+	(LongFunction<? super K> transformer,
4153	+	long basis,
4154	+	LongBinaryOperator reducer) {
4155	+	return ForkJoinTasks.reduceKeysToLong
4156	+	(this, transformer, basis, reducer).invoke();
4157	+	}
4158	+
4159	+	/**
4160	+	* Returns the result of accumulating the given transformation
4161	+	* of all keys using the given reducer to combine values, and
4162	+	* the given basis as an identity value.
4163	+	*
4164	+	* @param transformer a function returning the transformation
4165	+	* for an element
4166	+	* @param basis the identity (initial default value) for the reduction
4167	+	* @param reducer a commutative associative combining function
4168	+	* @return the result of accumulating the given transformation
4169	+	* of all keys
4170	+	*/
4171	+	public int reduceKeysToIntInParallel
4172	+	(IntFunction<? super K> transformer,
4173	+	int basis,
4174	+	IntBinaryOperator reducer) {
4175	+	return ForkJoinTasks.reduceKeysToInt
4176	+	(this, transformer, basis, reducer).invoke();
4177	+	}
4178	+
4179	+	/**
4180	+	* Performs the given action for each value.
4181	+	*
4182	+	* @param action the action
4183	+	*/
4184	+	public void forEachValueInParallel(Block<? super V> action) {
4185	+	ForkJoinTasks.forEachValue
4186	+	(this, action).invoke();
4187	+	}
4188	+
4189	+	/**
4190	+	* Performs the given action for each non-null transformation
4191	+	* of each value.
4192	+	*
4193	+	* @param transformer a function returning the transformation
4194	+	* for an element, or null of there is no transformation (in
4195	+	* which case the action is not applied).
4196	+	*/
4197	+	public <U> void forEachValueInParallel
4198	+	(Function<? super V, ? extends U> transformer,
4199	+	Block<? super U> action) {
4200	+	ForkJoinTasks.forEachValue
4201	+	(this, transformer, action).invoke();
4202	+	}
4203	+
4204	+	/**
4205	+	* Returns a non-null result from applying the given search
4206	+	* function on each value, or null if none.  Upon success,
4207	+	* further element processing is suppressed and the results of
4208	+	* any other parallel invocations of the search function are
4209	+	* ignored.
4210	+	*
4211	+	* @param searchFunction a function returning a non-null
4212	+	* result on success, else null
4213	+	* @return a non-null result from applying the given search
4214	+	* function on each value, or null if none
4215	+	*/
4216	+	public <U> U searchValuesInParallel
4217	+	(Function<? super V, ? extends U> searchFunction) {
4218	+	return ForkJoinTasks.searchValues
4219	+	(this, searchFunction).invoke();
4220	+	}
4221	+
4222	+	/**
4223	+	* Returns the result of accumulating all values using the
4224	+	* given reducer to combine values, or null if none.
4225	+	*
4226	+	* @param reducer a commutative associative combining function
4227	+	* @return the result of accumulating all values
4228	+	*/
4229	+	public V reduceValuesInParallel
4230	+	(BiFunction<? super V, ? super V, ? extends V> reducer) {
4231	+	return ForkJoinTasks.reduceValues
4232	+	(this, reducer).invoke();
4233	+	}
4234	+
4235	+	/**
4236	+	* Returns the result of accumulating the given transformation
4237	+	* of all values using the given reducer to combine values, or
4238	+	* null if none.
4239	+	*
4240	+	* @param transformer a function returning the transformation
4241	+	* for an element, or null of there is no transformation (in
4242	+	* which case it is not combined).
4243	+	* @param reducer a commutative associative combining function
4244	+	* @return the result of accumulating the given transformation
4245	+	* of all values
4246	+	*/
4247	+	public <U> U reduceValuesInParallel
4248	+	(Function<? super V, ? extends U> transformer,
4249	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4250	+	return ForkJoinTasks.reduceValues
4251	+	(this, transformer, reducer).invoke();
4252	+	}
4253	+
4254	+	/**
4255	+	* Returns the result of accumulating the given transformation
4256	+	* of all values using the given reducer to combine values,
4257	+	* and the given basis as an identity value.
4258	+	*
4259	+	* @param transformer a function returning the transformation
4260	+	* for an element
4261	+	* @param basis the identity (initial default value) for the reduction
4262	+	* @param reducer a commutative associative combining function
4263	+	* @return the result of accumulating the given transformation
4264	+	* of all values
4265	+	*/
4266	+	public double reduceValuesToDoubleInParallel
4267	+	(DoubleFunction<? super V> transformer,
4268	+	double basis,
4269	+	DoubleBinaryOperator reducer) {
4270	+	return ForkJoinTasks.reduceValuesToDouble
4271	+	(this, transformer, basis, reducer).invoke();
4272	+	}
4273	+
4274	+	/**
4275	+	* Returns the result of accumulating the given transformation
4276	+	* of all values using the given reducer to combine values,
4277	+	* and the given basis as an identity value.
4278	+	*
4279	+	* @param transformer a function returning the transformation
4280	+	* for an element
4281	+	* @param basis the identity (initial default value) for the reduction
4282	+	* @param reducer a commutative associative combining function
4283	+	* @return the result of accumulating the given transformation
4284	+	* of all values
4285	+	*/
4286	+	public long reduceValuesToLongInParallel
4287	+	(LongFunction<? super V> transformer,
4288	+	long basis,
4289	+	LongBinaryOperator reducer) {
4290	+	return ForkJoinTasks.reduceValuesToLong
4291	+	(this, transformer, basis, reducer).invoke();
4292		}
4293
4294	<	private class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4295	<	public Iterator<Map.Entry<K,V>> iterator() {
4296	<	return new EntryIterator();
4294	>	/**
4295	>	* Returns the result of accumulating the given transformation
4296	>	* of all values using the given reducer to combine values,
4297	>	* and the given basis as an identity value.
4298	>	*
4299	>	* @param transformer a function returning the transformation
4300	>	* for an element
4301	>	* @param basis the identity (initial default value) for the reduction
4302	>	* @param reducer a commutative associative combining function
4303	>	* @return the result of accumulating the given transformation
4304	>	* of all values
4305	>	*/
4306	>	public int reduceValuesToIntInParallel
4307	>	(IntFunction<? super V> transformer,
4308	>	int basis,
4309	>	IntBinaryOperator reducer) {
4310	>	return ForkJoinTasks.reduceValuesToInt
4311	>	(this, transformer, basis, reducer).invoke();
4312	>	}
4313	>
4314	>	/**
4315	>	* Performs the given action for each entry.
4316	>	*
4317	>	* @param action the action
4318	>	*/
4319	>	public void forEachEntryInParallel(Block<? super Map.Entry<K,V>> action) {
4320	>	ForkJoinTasks.forEachEntry
4321	>	(this, action).invoke();
4322	>	}
4323	>
4324	>	/**
4325	>	* Performs the given action for each non-null transformation
4326	>	* of each entry.
4327	>	*
4328	>	* @param transformer a function returning the transformation
4329	>	* for an element, or null of there is no transformation (in
4330	>	* which case the action is not applied).
4331	>	* @param action the action
4332	>	*/
4333	>	public <U> void forEachEntryInParallel
4334	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4335	>	Block<? super U> action) {
4336	>	ForkJoinTasks.forEachEntry
4337	>	(this, transformer, action).invoke();
4338	>	}
4339	>
4340	>	/**
4341	>	* Returns a non-null result from applying the given search
4342	>	* function on each entry, or null if none.  Upon success,
4343	>	* further element processing is suppressed and the results of
4344	>	* any other parallel invocations of the search function are
4345	>	* ignored.
4346	>	*
4347	>	* @param searchFunction a function returning a non-null
4348	>	* result on success, else null
4349	>	* @return a non-null result from applying the given search
4350	>	* function on each entry, or null if none
4351	>	*/
4352	>	public <U> U searchEntriesInParallel
4353	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4354	>	return ForkJoinTasks.searchEntries
4355	>	(this, searchFunction).invoke();
4356	>	}
4357	>
4358	>	/**
4359	>	* Returns the result of accumulating all entries using the
4360	>	* given reducer to combine values, or null if none.
4361	>	*
4362	>	* @param reducer a commutative associative combining function
4363	>	* @return the result of accumulating all entries
4364	>	*/
4365	>	public Map.Entry<K,V> reduceEntriesInParallel
4366	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4367	>	return ForkJoinTasks.reduceEntries
4368	>	(this, reducer).invoke();
4369	>	}
4370	>
4371	>	/**
4372	>	* Returns the result of accumulating the given transformation
4373	>	* of all entries using the given reducer to combine values,
4374	>	* or null if none.
4375	>	*
4376	>	* @param transformer a function returning the transformation
4377	>	* for an element, or null of there is no transformation (in
4378	>	* which case it is not combined).
4379	>	* @param reducer a commutative associative combining function
4380	>	* @return the result of accumulating the given transformation
4381	>	* of all entries
4382	>	*/
4383	>	public <U> U reduceEntriesInParallel
4384	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4385	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4386	>	return ForkJoinTasks.reduceEntries
4387	>	(this, transformer, reducer).invoke();
4388	>	}
4389	>
4390	>	/**
4391	>	* Returns the result of accumulating the given transformation
4392	>	* of all entries using the given reducer to combine values,
4393	>	* and the given basis as an identity value.
4394	>	*
4395	>	* @param transformer a function returning the transformation
4396	>	* for an element
4397	>	* @param basis the identity (initial default value) for the reduction
4398	>	* @param reducer a commutative associative combining function
4399	>	* @return the result of accumulating the given transformation
4400	>	* of all entries
4401	>	*/
4402	>	public double reduceEntriesToDoubleInParallel
4403	>	(DoubleFunction<Map.Entry<K,V>> transformer,
4404	>	double basis,
4405	>	DoubleBinaryOperator reducer) {
4406	>	return ForkJoinTasks.reduceEntriesToDouble
4407	>	(this, transformer, basis, reducer).invoke();
4408	>	}
4409	>
4410	>	/**
4411	>	* Returns the result of accumulating the given transformation
4412	>	* of all entries using the given reducer to combine values,
4413	>	* and the given basis as an identity value.
4414	>	*
4415	>	* @param transformer a function returning the transformation
4416	>	* for an element
4417	>	* @param basis the identity (initial default value) for the reduction
4418	>	* @param reducer a commutative associative combining function
4419	>	* @return the result of accumulating the given transformation
4420	>	* of all entries
4421	>	*/
4422	>	public long reduceEntriesToLongInParallel
4423	>	(LongFunction<Map.Entry<K,V>> transformer,
4424	>	long basis,
4425	>	LongBinaryOperator reducer) {
4426	>	return ForkJoinTasks.reduceEntriesToLong
4427	>	(this, transformer, basis, reducer).invoke();
4428	>	}
4429	>
4430	>	/**
4431	>	* Returns the result of accumulating the given transformation
4432	>	* of all entries using the given reducer to combine values,
4433	>	* and the given basis as an identity value.
4434	>	*
4435	>	* @param transformer a function returning the transformation
4436	>	* for an element
4437	>	* @param basis the identity (initial default value) for the reduction
4438	>	* @param reducer a commutative associative combining function
4439	>	* @return the result of accumulating the given transformation
4440	>	* of all entries
4441	>	*/
4442	>	public int reduceEntriesToIntInParallel
4443	>	(IntFunction<Map.Entry<K,V>> transformer,
4444	>	int basis,
4445	>	IntBinaryOperator reducer) {
4446	>	return ForkJoinTasks.reduceEntriesToInt
4447	>	(this, transformer, basis, reducer).invoke();
4448	>	}
4449	>
4450	>
4451	>	/* ----------------Views -------------- */
4452	>
4453	>	/**
4454	>	* Base class for views.
4455	>	*/
4456	>	static abstract class CHMView<K, V> {
4457	>	final ConcurrentHashMap<K, V> map;
4458	>	CHMView(ConcurrentHashMap<K, V> map)  { this.map = map; }
4459	>
4460	>	/**
4461	>	* Returns the map backing this view.
4462	>	*
4463	>	* @return the map backing this view
4464	>	*/
4465	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4466	>
4467	>	public final int size()                 { return map.size(); }
4468	>	public final boolean isEmpty()          { return map.isEmpty(); }
4469	>	public final void clear()               { map.clear(); }
4470	>
4471	>	// implementations below rely on concrete classes supplying these
4472	>	abstract public Iterator<?> iterator();
4473	>	abstract public boolean contains(Object o);
4474	>	abstract public boolean remove(Object o);
4475	>
4476	>	private static final String oomeMsg = "Required array size too large";
4477	>
4478	>	public final Object[] toArray() {
4479	>	long sz = map.mappingCount();
4480	>	if (sz > (long)(MAX_ARRAY_SIZE))
4481	>	throw new OutOfMemoryError(oomeMsg);
4482	>	int n = (int)sz;
4483	>	Object[] r = new Object[n];
4484	>	int i = 0;
4485	>	Iterator<?> it = iterator();
4486	>	while (it.hasNext()) {
4487	>	if (i == n) {
4488	>	if (n >= MAX_ARRAY_SIZE)
4489	>	throw new OutOfMemoryError(oomeMsg);
4490	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4491	>	n = MAX_ARRAY_SIZE;
4492	>	else
4493	>	n += (n >>> 1) + 1;
4494	>	r = Arrays.copyOf(r, n);
4495	>	}
4496	>	r[i++] = it.next();
4497	>	}
4498	>	return (i == n) ? r : Arrays.copyOf(r, i);
4499		}
4500	<	public boolean contains(Object o) {
4501	<	if (!(o instanceof Map.Entry))
4502	<	return false;
4503	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4504	<	V v = ConcurrentHashMap.this.get(e.getKey());
4505	<	return v != null && v.equals(e.getValue());
4500	>
4501	>	@SuppressWarnings("unchecked") public final <T> T[] toArray(T[] a) {
4502	>	long sz = map.mappingCount();
4503	>	if (sz > (long)(MAX_ARRAY_SIZE))
4504	>	throw new OutOfMemoryError(oomeMsg);
4505	>	int m = (int)sz;
4506	>	T[] r = (a.length >= m) ? a :
4507	>	(T[])java.lang.reflect.Array
4508	>	.newInstance(a.getClass().getComponentType(), m);
4509	>	int n = r.length;
4510	>	int i = 0;
4511	>	Iterator<?> it = iterator();
4512	>	while (it.hasNext()) {
4513	>	if (i == n) {
4514	>	if (n >= MAX_ARRAY_SIZE)
4515	>	throw new OutOfMemoryError(oomeMsg);
4516	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4517	>	n = MAX_ARRAY_SIZE;
4518	>	else
4519	>	n += (n >>> 1) + 1;
4520	>	r = Arrays.copyOf(r, n);
4521	>	}
4522	>	r[i++] = (T)it.next();
4523	>	}
4524	>	if (a == r && i < n) {
4525	>	r[i] = null; // null-terminate
4526	>	return r;
4527	>	}
4528	>	return (i == n) ? r : Arrays.copyOf(r, i);
4529		}
4530	<	public boolean remove(Object o) {
4531	<	if (!(o instanceof Map.Entry))
4532	<	return false;
4533	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4534	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4530	>
4531	>	public final int hashCode() {
4532	>	int h = 0;
4533	>	for (Iterator<?> it = iterator(); it.hasNext();)
4534	>	h += it.next().hashCode();
4535	>	return h;
4536		}
4537	<	public int size() {
4538	<	return ConcurrentHashMap.this.size();
4537	>
4538	>	public final String toString() {
4539	>	StringBuilder sb = new StringBuilder();
4540	>	sb.append('[');
4541	>	Iterator<?> it = iterator();
4542	>	if (it.hasNext()) {
4543	>	for (;;) {
4544	>	Object e = it.next();
4545	>	sb.append(e == this ? "(this Collection)" : e);
4546	>	if (!it.hasNext())
4547	>	break;
4548	>	sb.append(',').append(' ');
4549	>	}
4550	>	}
4551	>	return sb.append(']').toString();
4552		}
4553	<	public void clear() {
4554	<	ConcurrentHashMap.this.clear();
4553	>
4554	>	public final boolean containsAll(Collection<?> c) {
4555	>	if (c != this) {
4556	>	for (Iterator<?> it = c.iterator(); it.hasNext();) {
4557	>	Object e = it.next();
4558	>	if (e == null || !contains(e))
4559	>	return false;
4560	>	}
4561	>	}
4562	>	return true;
4563		}
1072	–	}
4564
4565	<	/* ---------------- Serialization Support -------------- */
4565	>	public final boolean removeAll(Collection<?> c) {
4566	>	boolean modified = false;
4567	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4568	>	if (c.contains(it.next())) {
4569	>	it.remove();
4570	>	modified = true;
4571	>	}
4572	>	}
4573	>	return modified;
4574	>	}
4575	>
4576	>	public final boolean retainAll(Collection<?> c) {
4577	>	boolean modified = false;
4578	>	for (Iterator<?> it = iterator(); it.hasNext();) {
4579	>	if (!c.contains(it.next())) {
4580	>	it.remove();
4581	>	modified = true;
4582	>	}
4583	>	}
4584	>	return modified;
4585	>	}
4586	>
4587	>	}
4588
4589		/**
4590	<	* Save the state of the <tt>ConcurrentHashMap</tt>
4591	<	* instance to a stream (i.e.,
4592	<	* serialize it).
4593	<	* @param s the stream
4594	<	* @serialData
1082	<	* the key (Object) and value (Object)
1083	<	* for each key-value mapping, followed by a null pair.
1084	<	* The key-value mappings are emitted in no particular order.
4590	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4591	>	* which additions may optionally be enabled by mapping to a
4592	>	* common value.  This class cannot be directly instantiated. See
4593	>	* {@link #keySet}, {@link #keySet(Object)}, {@link #newKeySet()},
4594	>	* {@link #newKeySet(int)}.
4595		*/
4596	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4597	<	s.defaultWriteObject();
4596	>	public static class KeySetView<K,V> extends CHMView<K,V>
4597	>	implements Set<K>, java.io.Serializable {
4598	>	private static final long serialVersionUID = 7249069246763182397L;
4599	>	private final V value;
4600	>	KeySetView(ConcurrentHashMap<K, V> map, V value) {  // non-public
4601	>	super(map);
4602	>	this.value = value;
4603	>	}
4604
4605	<	for (int k = 0; k < segments.length; ++k) {
4606	<	Segment<K,V> seg = (Segment<K,V>)segments[k];
4607	<	seg.lock();
4608	<	try {
4609	<	HashEntry[] tab = seg.table;
4610	<	for (int i = 0; i < tab.length; ++i) {
4611	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
4612	<	s.writeObject(e.key);
4613	<	s.writeObject(e.value);
4605	>	/**
4606	>	* Returns the default mapped value for additions,
4607	>	* or {@code null} if additions are not supported.
4608	>	*
4609	>	* @return the default mapped value for additions, or {@code null}
4610	>	* if not supported.
4611	>	*/
4612	>	public V getMappedValue() { return value; }
4613	>
4614	>	// implement Set API
4615	>
4616	>	public boolean contains(Object o) { return map.containsKey(o); }
4617	>	public boolean remove(Object o)   { return map.remove(o) != null; }
4618	>
4619	>	/**
4620	>	* Returns a "weakly consistent" iterator that will never
4621	>	* throw {@link ConcurrentModificationException}, and
4622	>	* guarantees to traverse elements as they existed upon
4623	>	* construction of the iterator, and may (but is not
4624	>	* guaranteed to) reflect any modifications subsequent to
4625	>	* construction.
4626	>	*
4627	>	* @return an iterator over the keys of this map
4628	>	*/
4629	>	public Iterator<K> iterator()     { return new KeyIterator<K,V>(map); }
4630	>	public boolean add(K e) {
4631	>	V v;
4632	>	if ((v = value) == null)
4633	>	throw new UnsupportedOperationException();
4634	>	if (e == null)
4635	>	throw new NullPointerException();
4636	>	return map.internalPut(e, v, true) == null;
4637	>	}
4638	>	public boolean addAll(Collection<? extends K> c) {
4639	>	boolean added = false;
4640	>	V v;
4641	>	if ((v = value) == null)
4642	>	throw new UnsupportedOperationException();
4643	>	for (K e : c) {
4644	>	if (e == null)
4645	>	throw new NullPointerException();
4646	>	if (map.internalPut(e, v, true) == null)
4647	>	added = true;
4648	>	}
4649	>	return added;
4650	>	}
4651	>	public boolean equals(Object o) {
4652	>	Set<?> c;
4653	>	return ((o instanceof Set) &&
4654	>	((c = (Set<?>)o) == this ||
4655	>	(containsAll(c) && c.containsAll(this))));
4656	>	}
4657	>
4658	>	public Stream<K> stream() {
4659	>	return Streams.stream(() -> new KeyIterator<K,V>(map), 0);
4660	>	}
4661	>	public Stream<K> parallelStream() {
4662	>	return Streams.parallelStream(() -> new KeyIterator<K,V>(map, null),
4663	>	0);
4664	>	}
4665	>	}
4666	>
4667	>	/**
4668	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4669	>	* values, in which additions are disabled. This class cannot be
4670	>	* directly instantiated. See {@link #values},
4671	>	*
4672	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4673	>	* that will never throw {@link ConcurrentModificationException},
4674	>	* and guarantees to traverse elements as they existed upon
4675	>	* construction of the iterator, and may (but is not guaranteed to)
4676	>	* reflect any modifications subsequent to construction.
4677	>	*/
4678	>	public static final class ValuesView<K,V> extends CHMView<K,V>
4679	>	implements Collection<V> {
4680	>	ValuesView(ConcurrentHashMap<K, V> map)   { super(map); }
4681	>	public final boolean contains(Object o) { return map.containsValue(o); }
4682	>	public final boolean remove(Object o) {
4683	>	if (o != null) {
4684	>	Iterator<V> it = new ValueIterator<K,V>(map);
4685	>	while (it.hasNext()) {
4686	>	if (o.equals(it.next())) {
4687	>	it.remove();
4688	>	return true;
4689		}
4690		}
1100	–	} finally {
1101	–	seg.unlock();
4691		}
4692	+	return false;
4693		}
4694	<	s.writeObject(null);
4695	<	s.writeObject(null);
4694	>
4695	>	/**
4696	>	* Returns a "weakly consistent" iterator that will never
4697	>	* throw {@link ConcurrentModificationException}, and
4698	>	* guarantees to traverse elements as they existed upon
4699	>	* construction of the iterator, and may (but is not
4700	>	* guaranteed to) reflect any modifications subsequent to
4701	>	* construction.
4702	>	*
4703	>	* @return an iterator over the values of this map
4704	>	*/
4705	>	public final Iterator<V> iterator() {
4706	>	return new ValueIterator<K,V>(map);
4707	>	}
4708	>	public final boolean add(V e) {
4709	>	throw new UnsupportedOperationException();
4710	>	}
4711	>	public final boolean addAll(Collection<? extends V> c) {
4712	>	throw new UnsupportedOperationException();
4713	>	}
4714	>
4715	>	public Stream<V> stream() {
4716	>	return Streams.stream(() -> new ValueIterator<K,V>(map), 0);
4717	>	}
4718	>
4719	>	public Stream<V> parallelStream() {
4720	>	return Streams.parallelStream(() -> new ValueIterator<K,V>(map, null),
4721	>	0);
4722	>	}
4723	>
4724		}
4725
4726		/**
4727	<	* Reconstitute the <tt>ConcurrentHashMap</tt>
4728	<	* instance from a stream (i.e.,
4729	<	* deserialize it).
1112	<	* @param s the stream
4727	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4728	>	* entries.  This class cannot be directly instantiated. See
4729	>	* {@link #entrySet}.
4730		*/
4731	<	private void readObject(java.io.ObjectInputStream s)
4732	<	throws IOException, ClassNotFoundException  {
4733	<	s.defaultReadObject();
4731	>	public static final class EntrySetView<K,V> extends CHMView<K,V>
4732	>	implements Set<Map.Entry<K,V>> {
4733	>	EntrySetView(ConcurrentHashMap<K, V> map) { super(map); }
4734	>	public final boolean contains(Object o) {
4735	>	Object k, v, r; Map.Entry<?,?> e;
4736	>	return ((o instanceof Map.Entry) &&
4737	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4738	>	(r = map.get(k)) != null &&
4739	>	(v = e.getValue()) != null &&
4740	>	(v == r || v.equals(r)));
4741	>	}
4742	>	public final boolean remove(Object o) {
4743	>	Object k, v; Map.Entry<?,?> e;
4744	>	return ((o instanceof Map.Entry) &&
4745	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4746	>	(v = e.getValue()) != null &&
4747	>	map.remove(k, v));
4748	>	}
4749
4750	<	// Initialize each segment to be minimally sized, and let grow.
4751	<	for (int i = 0; i < segments.length; ++i) {
4752	<	segments[i].setTable(new HashEntry[1]);
4750	>	/**
4751	>	* Returns a "weakly consistent" iterator that will never
4752	>	* throw {@link ConcurrentModificationException}, and
4753	>	* guarantees to traverse elements as they existed upon
4754	>	* construction of the iterator, and may (but is not
4755	>	* guaranteed to) reflect any modifications subsequent to
4756	>	* construction.
4757	>	*
4758	>	* @return an iterator over the entries of this map
4759	>	*/
4760	>	public final Iterator<Map.Entry<K,V>> iterator() {
4761	>	return new EntryIterator<K,V>(map);
4762		}
4763
4764	<	// Read the keys and values, and put the mappings in the table
4765	<	for (;;) {
4766	<	K key = (K) s.readObject();
4767	<	V value = (V) s.readObject();
4768	<	if (key == null)
4769	<	break;
4770	<	put(key, value);
4764	>	public final boolean add(Entry<K,V> e) {
4765	>	K key = e.getKey();
4766	>	V value = e.getValue();
4767	>	if (key == null || value == null)
4768	>	throw new NullPointerException();
4769	>	return map.internalPut(key, value, false) == null;
4770	>	}
4771	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
4772	>	boolean added = false;
4773	>	for (Entry<K,V> e : c) {
4774	>	if (add(e))
4775	>	added = true;
4776	>	}
4777	>	return added;
4778	>	}
4779	>	public boolean equals(Object o) {
4780	>	Set<?> c;
4781	>	return ((o instanceof Set) &&
4782	>	((c = (Set<?>)o) == this ||
4783	>	(containsAll(c) && c.containsAll(this))));
4784	>	}
4785	>
4786	>	public Stream<Map.Entry<K,V>> stream() {
4787	>	return Streams.stream(() -> new EntryIterator<K,V>(map), 0);
4788	>	}
4789	>
4790	>	public Stream<Map.Entry<K,V>> parallelStream() {
4791	>	return Streams.parallelStream(() -> new EntryIterator<K,V>(map, null),
4792	>	0);
4793		}
4794		}
1132	–	}
4795
4796	+	// ---------------------------------------------------------------------
4797	+
4798	+	/**
4799	+	* Predefined tasks for performing bulk parallel operations on
4800	+	* ConcurrentHashMaps. These tasks follow the forms and rules used
4801	+	* for bulk operations. Each method has the same name, but returns
4802	+	* a task rather than invoking it. These methods may be useful in
4803	+	* custom applications such as submitting a task without waiting
4804	+	* for completion, using a custom pool, or combining with other
4805	+	* tasks.
4806	+	*/
4807	+	public static class ForkJoinTasks {
4808	+	private ForkJoinTasks() {}
4809	+
4810	+	/**
4811	+	* Returns a task that when invoked, performs the given
4812	+	* action for each (key, value)
4813	+	*
4814	+	* @param map the map
4815	+	* @param action the action
4816	+	* @return the task
4817	+	*/
4818	+	public static <K,V> ForkJoinTask<Void> forEach
4819	+	(ConcurrentHashMap<K,V> map,
4820	+	BiBlock<? super K, ? super V> action) {
4821	+	if (action == null) throw new NullPointerException();
4822	+	return new ForEachMappingTask<K,V>(map, null, -1, action);
4823	+	}
4824	+
4825	+	/**
4826	+	* Returns a task that when invoked, performs the given
4827	+	* action for each non-null transformation of each (key, value)
4828	+	*
4829	+	* @param map the map
4830	+	* @param transformer a function returning the transformation
4831	+	* for an element, or null if there is no transformation (in
4832	+	* which case the action is not applied)
4833	+	* @param action the action
4834	+	* @return the task
4835	+	*/
4836	+	public static <K,V,U> ForkJoinTask<Void> forEach
4837	+	(ConcurrentHashMap<K,V> map,
4838	+	BiFunction<? super K, ? super V, ? extends U> transformer,
4839	+	Block<? super U> action) {
4840	+	if (transformer == null || action == null)
4841	+	throw new NullPointerException();
4842	+	return new ForEachTransformedMappingTask<K,V,U>
4843	+	(map, null, -1, transformer, action);
4844	+	}
4845	+
4846	+	/**
4847	+	* Returns a task that when invoked, returns a non-null result
4848	+	* from applying the given search function on each (key,
4849	+	* value), or null if none. Upon success, further element
4850	+	* processing is suppressed and the results of any other
4851	+	* parallel invocations of the search function are ignored.
4852	+	*
4853	+	* @param map the map
4854	+	* @param searchFunction a function returning a non-null
4855	+	* result on success, else null
4856	+	* @return the task
4857	+	*/
4858	+	public static <K,V,U> ForkJoinTask<U> search
4859	+	(ConcurrentHashMap<K,V> map,
4860	+	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
4861	+	if (searchFunction == null) throw new NullPointerException();
4862	+	return new SearchMappingsTask<K,V,U>
4863	+	(map, null, -1, searchFunction,
4864	+	new AtomicReference<U>());
4865	+	}
4866	+
4867	+	/**
4868	+	* Returns a task that when invoked, returns the result of
4869	+	* accumulating the given transformation of all (key, value) pairs
4870	+	* using the given reducer to combine values, or null if none.
4871	+	*
4872	+	* @param map the map
4873	+	* @param transformer a function returning the transformation
4874	+	* for an element, or null if there is no transformation (in
4875	+	* which case it is not combined).
4876	+	* @param reducer a commutative associative combining function
4877	+	* @return the task
4878	+	*/
4879	+	public static <K,V,U> ForkJoinTask<U> reduce
4880	+	(ConcurrentHashMap<K,V> map,
4881	+	BiFunction<? super K, ? super V, ? extends U> transformer,
4882	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4883	+	if (transformer == null || reducer == null)
4884	+	throw new NullPointerException();
4885	+	return new MapReduceMappingsTask<K,V,U>
4886	+	(map, null, -1, null, transformer, reducer);
4887	+	}
4888	+
4889	+	/**
4890	+	* Returns a task that when invoked, returns the result of
4891	+	* accumulating the given transformation of all (key, value) pairs
4892	+	* using the given reducer to combine values, and the given
4893	+	* basis as an identity value.
4894	+	*
4895	+	* @param map the map
4896	+	* @param transformer a function returning the transformation
4897	+	* for an element
4898	+	* @param basis the identity (initial default value) for the reduction
4899	+	* @param reducer a commutative associative combining function
4900	+	* @return the task
4901	+	*/
4902	+	public static <K,V> ForkJoinTask<Double> reduceToDouble
4903	+	(ConcurrentHashMap<K,V> map,
4904	+	DoubleBiFunction<? super K, ? super V> transformer,
4905	+	double basis,
4906	+	DoubleBinaryOperator reducer) {
4907	+	if (transformer == null || reducer == null)
4908	+	throw new NullPointerException();
4909	+	return new MapReduceMappingsToDoubleTask<K,V>
4910	+	(map, null, -1, null, transformer, basis, reducer);
4911	+	}
4912	+
4913	+	/**
4914	+	* Returns a task that when invoked, returns the result of
4915	+	* accumulating the given transformation of all (key, value) pairs
4916	+	* using the given reducer to combine values, and the given
4917	+	* basis as an identity value.
4918	+	*
4919	+	* @param map the map
4920	+	* @param transformer a function returning the transformation
4921	+	* for an element
4922	+	* @param basis the identity (initial default value) for the reduction
4923	+	* @param reducer a commutative associative combining function
4924	+	* @return the task
4925	+	*/
4926	+	public static <K,V> ForkJoinTask<Long> reduceToLong
4927	+	(ConcurrentHashMap<K,V> map,
4928	+	LongBiFunction<? super K, ? super V> transformer,
4929	+	long basis,
4930	+	LongBinaryOperator reducer) {
4931	+	if (transformer == null || reducer == null)
4932	+	throw new NullPointerException();
4933	+	return new MapReduceMappingsToLongTask<K,V>
4934	+	(map, null, -1, null, transformer, basis, reducer);
4935	+	}
4936	+
4937	+	/**
4938	+	* Returns a task that when invoked, returns the result of
4939	+	* accumulating the given transformation of all (key, value) pairs
4940	+	* using the given reducer to combine values, and the given
4941	+	* basis as an identity value.
4942	+	*
4943	+	* @param transformer a function returning the transformation
4944	+	* for an element
4945	+	* @param basis the identity (initial default value) for the reduction
4946	+	* @param reducer a commutative associative combining function
4947	+	* @return the task
4948	+	*/
4949	+	public static <K,V> ForkJoinTask<Integer> reduceToInt
4950	+	(ConcurrentHashMap<K,V> map,
4951	+	IntBiFunction<? super K, ? super V> transformer,
4952	+	int basis,
4953	+	IntBinaryOperator reducer) {
4954	+	if (transformer == null || reducer == null)
4955	+	throw new NullPointerException();
4956	+	return new MapReduceMappingsToIntTask<K,V>
4957	+	(map, null, -1, null, transformer, basis, reducer);
4958	+	}
4959	+
4960	+	/**
4961	+	* Returns a task that when invoked, performs the given action
4962	+	* for each key.
4963	+	*
4964	+	* @param map the map
4965	+	* @param action the action
4966	+	* @return the task
4967	+	*/
4968	+	public static <K,V> ForkJoinTask<Void> forEachKey
4969	+	(ConcurrentHashMap<K,V> map,
4970	+	Block<? super K> action) {
4971	+	if (action == null) throw new NullPointerException();
4972	+	return new ForEachKeyTask<K,V>(map, null, -1, action);
4973	+	}
4974	+
4975	+	/**
4976	+	* Returns a task that when invoked, performs the given action
4977	+	* for each non-null transformation of each key.
4978	+	*
4979	+	* @param map the map
4980	+	* @param transformer a function returning the transformation
4981	+	* for an element, or null if there is no transformation (in
4982	+	* which case the action is not applied)
4983	+	* @param action the action
4984	+	* @return the task
4985	+	*/
4986	+	public static <K,V,U> ForkJoinTask<Void> forEachKey
4987	+	(ConcurrentHashMap<K,V> map,
4988	+	Function<? super K, ? extends U> transformer,
4989	+	Block<? super U> action) {
4990	+	if (transformer == null || action == null)
4991	+	throw new NullPointerException();
4992	+	return new ForEachTransformedKeyTask<K,V,U>
4993	+	(map, null, -1, transformer, action);
4994	+	}
4995	+
4996	+	/**
4997	+	* Returns a task that when invoked, returns a non-null result
4998	+	* from applying the given search function on each key, or
4999	+	* null if none.  Upon success, further element processing is
5000	+	* suppressed and the results of any other parallel
5001	+	* invocations of the search function are ignored.
5002	+	*
5003	+	* @param map the map
5004	+	* @param searchFunction a function returning a non-null
5005	+	* result on success, else null
5006	+	* @return the task
5007	+	*/
5008	+	public static <K,V,U> ForkJoinTask<U> searchKeys
5009	+	(ConcurrentHashMap<K,V> map,
5010	+	Function<? super K, ? extends U> searchFunction) {
5011	+	if (searchFunction == null) throw new NullPointerException();
5012	+	return new SearchKeysTask<K,V,U>
5013	+	(map, null, -1, searchFunction,
5014	+	new AtomicReference<U>());
5015	+	}
5016	+
5017	+	/**
5018	+	* Returns a task that when invoked, returns the result of
5019	+	* accumulating all keys using the given reducer to combine
5020	+	* values, or null if none.
5021	+	*
5022	+	* @param map the map
5023	+	* @param reducer a commutative associative combining function
5024	+	* @return the task
5025	+	*/
5026	+	public static <K,V> ForkJoinTask<K> reduceKeys
5027	+	(ConcurrentHashMap<K,V> map,
5028	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5029	+	if (reducer == null) throw new NullPointerException();
5030	+	return new ReduceKeysTask<K,V>
5031	+	(map, null, -1, null, reducer);
5032	+	}
5033	+
5034	+	/**
5035	+	* Returns a task that when invoked, returns the result of
5036	+	* accumulating the given transformation of all keys using the given
5037	+	* reducer to combine values, or null if none.
5038	+	*
5039	+	* @param map the map
5040	+	* @param transformer a function returning the transformation
5041	+	* for an element, or null if there is no transformation (in
5042	+	* which case it is not combined).
5043	+	* @param reducer a commutative associative combining function
5044	+	* @return the task
5045	+	*/
5046	+	public static <K,V,U> ForkJoinTask<U> reduceKeys
5047	+	(ConcurrentHashMap<K,V> map,
5048	+	Function<? super K, ? extends U> transformer,
5049	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5050	+	if (transformer == null || reducer == null)
5051	+	throw new NullPointerException();
5052	+	return new MapReduceKeysTask<K,V,U>
5053	+	(map, null, -1, null, transformer, reducer);
5054	+	}
5055	+
5056	+	/**
5057	+	* Returns a task that when invoked, returns the result of
5058	+	* accumulating the given transformation of all keys using the given
5059	+	* reducer to combine values, and the given basis as an
5060	+	* identity value.
5061	+	*
5062	+	* @param map the map
5063	+	* @param transformer a function returning the transformation
5064	+	* for an element
5065	+	* @param basis the identity (initial default value) for the reduction
5066	+	* @param reducer a commutative associative combining function
5067	+	* @return the task
5068	+	*/
5069	+	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
5070	+	(ConcurrentHashMap<K,V> map,
5071	+	DoubleFunction<? super K> transformer,
5072	+	double basis,
5073	+	DoubleBinaryOperator reducer) {
5074	+	if (transformer == null || reducer == null)
5075	+	throw new NullPointerException();
5076	+	return new MapReduceKeysToDoubleTask<K,V>
5077	+	(map, null, -1, null, transformer, basis, reducer);
5078	+	}
5079	+
5080	+	/**
5081	+	* Returns a task that when invoked, returns the result of
5082	+	* accumulating the given transformation of all keys using the given
5083	+	* reducer to combine values, and the given basis as an
5084	+	* identity value.
5085	+	*
5086	+	* @param map the map
5087	+	* @param transformer a function returning the transformation
5088	+	* for an element
5089	+	* @param basis the identity (initial default value) for the reduction
5090	+	* @param reducer a commutative associative combining function
5091	+	* @return the task
5092	+	*/
5093	+	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
5094	+	(ConcurrentHashMap<K,V> map,
5095	+	LongFunction<? super K> transformer,
5096	+	long basis,
5097	+	LongBinaryOperator reducer) {
5098	+	if (transformer == null || reducer == null)
5099	+	throw new NullPointerException();
5100	+	return new MapReduceKeysToLongTask<K,V>
5101	+	(map, null, -1, null, transformer, basis, reducer);
5102	+	}
5103	+
5104	+	/**
5105	+	* Returns a task that when invoked, returns the result of
5106	+	* accumulating the given transformation of all keys using the given
5107	+	* reducer to combine values, and the given basis as an
5108	+	* identity value.
5109	+	*
5110	+	* @param map the map
5111	+	* @param transformer a function returning the transformation
5112	+	* for an element
5113	+	* @param basis the identity (initial default value) for the reduction
5114	+	* @param reducer a commutative associative combining function
5115	+	* @return the task
5116	+	*/
5117	+	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5118	+	(ConcurrentHashMap<K,V> map,
5119	+	IntFunction<? super K> transformer,
5120	+	int basis,
5121	+	IntBinaryOperator reducer) {
5122	+	if (transformer == null || reducer == null)
5123	+	throw new NullPointerException();
5124	+	return new MapReduceKeysToIntTask<K,V>
5125	+	(map, null, -1, null, transformer, basis, reducer);
5126	+	}
5127	+
5128	+	/**
5129	+	* Returns a task that when invoked, performs the given action
5130	+	* for each value.
5131	+	*
5132	+	* @param map the map
5133	+	* @param action the action
5134	+	*/
5135	+	public static <K,V> ForkJoinTask<Void> forEachValue
5136	+	(ConcurrentHashMap<K,V> map,
5137	+	Block<? super V> action) {
5138	+	if (action == null) throw new NullPointerException();
5139	+	return new ForEachValueTask<K,V>(map, null, -1, action);
5140	+	}
5141	+
5142	+	/**
5143	+	* Returns a task that when invoked, performs the given action
5144	+	* for each non-null transformation of each value.
5145	+	*
5146	+	* @param map the map
5147	+	* @param transformer a function returning the transformation
5148	+	* for an element, or null if there is no transformation (in
5149	+	* which case the action is not applied)
5150	+	* @param action the action
5151	+	*/
5152	+	public static <K,V,U> ForkJoinTask<Void> forEachValue
5153	+	(ConcurrentHashMap<K,V> map,
5154	+	Function<? super V, ? extends U> transformer,
5155	+	Block<? super U> action) {
5156	+	if (transformer == null || action == null)
5157	+	throw new NullPointerException();
5158	+	return new ForEachTransformedValueTask<K,V,U>
5159	+	(map, null, -1, transformer, action);
5160	+	}
5161	+
5162	+	/**
5163	+	* Returns a task that when invoked, returns a non-null result
5164	+	* from applying the given search function on each value, or
5165	+	* null if none.  Upon success, further element processing is
5166	+	* suppressed and the results of any other parallel
5167	+	* invocations of the search function are ignored.
5168	+	*
5169	+	* @param map the map
5170	+	* @param searchFunction a function returning a non-null
5171	+	* result on success, else null
5172	+	* @return the task
5173	+	*/
5174	+	public static <K,V,U> ForkJoinTask<U> searchValues
5175	+	(ConcurrentHashMap<K,V> map,
5176	+	Function<? super V, ? extends U> searchFunction) {
5177	+	if (searchFunction == null) throw new NullPointerException();
5178	+	return new SearchValuesTask<K,V,U>
5179	+	(map, null, -1, searchFunction,
5180	+	new AtomicReference<U>());
5181	+	}
5182	+
5183	+	/**
5184	+	* Returns a task that when invoked, returns the result of
5185	+	* accumulating all values using the given reducer to combine
5186	+	* values, or null if none.
5187	+	*
5188	+	* @param map the map
5189	+	* @param reducer a commutative associative combining function
5190	+	* @return the task
5191	+	*/
5192	+	public static <K,V> ForkJoinTask<V> reduceValues
5193	+	(ConcurrentHashMap<K,V> map,
5194	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5195	+	if (reducer == null) throw new NullPointerException();
5196	+	return new ReduceValuesTask<K,V>
5197	+	(map, null, -1, null, reducer);
5198	+	}
5199	+
5200	+	/**
5201	+	* Returns a task that when invoked, returns the result of
5202	+	* accumulating the given transformation of all values using the
5203	+	* given reducer to combine values, or null if none.
5204	+	*
5205	+	* @param map the map
5206	+	* @param transformer a function returning the transformation
5207	+	* for an element, or null if there is no transformation (in
5208	+	* which case it is not combined).
5209	+	* @param reducer a commutative associative combining function
5210	+	* @return the task
5211	+	*/
5212	+	public static <K,V,U> ForkJoinTask<U> reduceValues
5213	+	(ConcurrentHashMap<K,V> map,
5214	+	Function<? super V, ? extends U> transformer,
5215	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5216	+	if (transformer == null || reducer == null)
5217	+	throw new NullPointerException();
5218	+	return new MapReduceValuesTask<K,V,U>
5219	+	(map, null, -1, null, transformer, reducer);
5220	+	}
5221	+
5222	+	/**
5223	+	* Returns a task that when invoked, returns the result of
5224	+	* accumulating the given transformation of all values using the
5225	+	* given reducer to combine values, and the given basis as an
5226	+	* identity value.
5227	+	*
5228	+	* @param map the map
5229	+	* @param transformer a function returning the transformation
5230	+	* for an element
5231	+	* @param basis the identity (initial default value) for the reduction
5232	+	* @param reducer a commutative associative combining function
5233	+	* @return the task
5234	+	*/
5235	+	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5236	+	(ConcurrentHashMap<K,V> map,
5237	+	DoubleFunction<? super V> transformer,
5238	+	double basis,
5239	+	DoubleBinaryOperator reducer) {
5240	+	if (transformer == null || reducer == null)
5241	+	throw new NullPointerException();
5242	+	return new MapReduceValuesToDoubleTask<K,V>
5243	+	(map, null, -1, null, transformer, basis, reducer);
5244	+	}
5245	+
5246	+	/**
5247	+	* Returns a task that when invoked, returns the result of
5248	+	* accumulating the given transformation of all values using the
5249	+	* given reducer to combine values, and the given basis as an
5250	+	* identity value.
5251	+	*
5252	+	* @param map the map
5253	+	* @param transformer a function returning the transformation
5254	+	* for an element
5255	+	* @param basis the identity (initial default value) for the reduction
5256	+	* @param reducer a commutative associative combining function
5257	+	* @return the task
5258	+	*/
5259	+	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5260	+	(ConcurrentHashMap<K,V> map,
5261	+	LongFunction<? super V> transformer,
5262	+	long basis,
5263	+	LongBinaryOperator reducer) {
5264	+	if (transformer == null || reducer == null)
5265	+	throw new NullPointerException();
5266	+	return new MapReduceValuesToLongTask<K,V>
5267	+	(map, null, -1, null, transformer, basis, reducer);
5268	+	}
5269	+
5270	+	/**
5271	+	* Returns a task that when invoked, returns the result of
5272	+	* accumulating the given transformation of all values using the
5273	+	* given reducer to combine values, and the given basis as an
5274	+	* identity value.
5275	+	*
5276	+	* @param map the map
5277	+	* @param transformer a function returning the transformation
5278	+	* for an element
5279	+	* @param basis the identity (initial default value) for the reduction
5280	+	* @param reducer a commutative associative combining function
5281	+	* @return the task
5282	+	*/
5283	+	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5284	+	(ConcurrentHashMap<K,V> map,
5285	+	IntFunction<? super V> transformer,
5286	+	int basis,
5287	+	IntBinaryOperator reducer) {
5288	+	if (transformer == null || reducer == null)
5289	+	throw new NullPointerException();
5290	+	return new MapReduceValuesToIntTask<K,V>
5291	+	(map, null, -1, null, transformer, basis, reducer);
5292	+	}
5293	+
5294	+	/**
5295	+	* Returns a task that when invoked, perform the given action
5296	+	* for each entry.
5297	+	*
5298	+	* @param map the map
5299	+	* @param action the action
5300	+	*/
5301	+	public static <K,V> ForkJoinTask<Void> forEachEntry
5302	+	(ConcurrentHashMap<K,V> map,
5303	+	Block<? super Map.Entry<K,V>> action) {
5304	+	if (action == null) throw new NullPointerException();
5305	+	return new ForEachEntryTask<K,V>(map, null, -1, action);
5306	+	}
5307	+
5308	+	/**
5309	+	* Returns a task that when invoked, perform the given action
5310	+	* for each non-null transformation of each entry.
5311	+	*
5312	+	* @param map the map
5313	+	* @param transformer a function returning the transformation
5314	+	* for an element, or null if there is no transformation (in
5315	+	* which case the action is not applied)
5316	+	* @param action the action
5317	+	*/
5318	+	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5319	+	(ConcurrentHashMap<K,V> map,
5320	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5321	+	Block<? super U> action) {
5322	+	if (transformer == null || action == null)
5323	+	throw new NullPointerException();
5324	+	return new ForEachTransformedEntryTask<K,V,U>
5325	+	(map, null, -1, transformer, action);
5326	+	}
5327	+
5328	+	/**
5329	+	* Returns a task that when invoked, returns a non-null result
5330	+	* from applying the given search function on each entry, or
5331	+	* null if none.  Upon success, further element processing is
5332	+	* suppressed and the results of any other parallel
5333	+	* invocations of the search function are ignored.
5334	+	*
5335	+	* @param map the map
5336	+	* @param searchFunction a function returning a non-null
5337	+	* result on success, else null
5338	+	* @return the task
5339	+	*/
5340	+	public static <K,V,U> ForkJoinTask<U> searchEntries
5341	+	(ConcurrentHashMap<K,V> map,
5342	+	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
5343	+	if (searchFunction == null) throw new NullPointerException();
5344	+	return new SearchEntriesTask<K,V,U>
5345	+	(map, null, -1, searchFunction,
5346	+	new AtomicReference<U>());
5347	+	}
5348	+
5349	+	/**
5350	+	* Returns a task that when invoked, returns the result of
5351	+	* accumulating all entries using the given reducer to combine
5352	+	* values, or null if none.
5353	+	*
5354	+	* @param map the map
5355	+	* @param reducer a commutative associative combining function
5356	+	* @return the task
5357	+	*/
5358	+	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5359	+	(ConcurrentHashMap<K,V> map,
5360	+	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5361	+	if (reducer == null) throw new NullPointerException();
5362	+	return new ReduceEntriesTask<K,V>
5363	+	(map, null, -1, null, reducer);
5364	+	}
5365	+
5366	+	/**
5367	+	* Returns a task that when invoked, returns the result of
5368	+	* accumulating the given transformation of all entries using the
5369	+	* given reducer to combine values, or null if none.
5370	+	*
5371	+	* @param map the map
5372	+	* @param transformer a function returning the transformation
5373	+	* for an element, or null if there is no transformation (in
5374	+	* which case it is not combined).
5375	+	* @param reducer a commutative associative combining function
5376	+	* @return the task
5377	+	*/
5378	+	public static <K,V,U> ForkJoinTask<U> reduceEntries
5379	+	(ConcurrentHashMap<K,V> map,
5380	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5381	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5382	+	if (transformer == null || reducer == null)
5383	+	throw new NullPointerException();
5384	+	return new MapReduceEntriesTask<K,V,U>
5385	+	(map, null, -1, null, transformer, reducer);
5386	+	}
5387	+
5388	+	/**
5389	+	* Returns a task that when invoked, returns the result of
5390	+	* accumulating the given transformation of all entries using the
5391	+	* given reducer to combine values, and the given basis as an
5392	+	* identity value.
5393	+	*
5394	+	* @param map the map
5395	+	* @param transformer a function returning the transformation
5396	+	* for an element
5397	+	* @param basis the identity (initial default value) for the reduction
5398	+	* @param reducer a commutative associative combining function
5399	+	* @return the task
5400	+	*/
5401	+	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5402	+	(ConcurrentHashMap<K,V> map,
5403	+	DoubleFunction<Map.Entry<K,V>> transformer,
5404	+	double basis,
5405	+	DoubleBinaryOperator reducer) {
5406	+	if (transformer == null || reducer == null)
5407	+	throw new NullPointerException();
5408	+	return new MapReduceEntriesToDoubleTask<K,V>
5409	+	(map, null, -1, null, transformer, basis, reducer);
5410	+	}
5411	+
5412	+	/**
5413	+	* Returns a task that when invoked, returns the result of
5414	+	* accumulating the given transformation of all entries using the
5415	+	* given reducer to combine values, and the given basis as an
5416	+	* identity value.
5417	+	*
5418	+	* @param map the map
5419	+	* @param transformer a function returning the transformation
5420	+	* for an element
5421	+	* @param basis the identity (initial default value) for the reduction
5422	+	* @param reducer a commutative associative combining function
5423	+	* @return the task
5424	+	*/
5425	+	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5426	+	(ConcurrentHashMap<K,V> map,
5427	+	LongFunction<Map.Entry<K,V>> transformer,
5428	+	long basis,
5429	+	LongBinaryOperator reducer) {
5430	+	if (transformer == null || reducer == null)
5431	+	throw new NullPointerException();
5432	+	return new MapReduceEntriesToLongTask<K,V>
5433	+	(map, null, -1, null, transformer, basis, reducer);
5434	+	}
5435	+
5436	+	/**
5437	+	* Returns a task that when invoked, returns the result of
5438	+	* accumulating the given transformation of all entries using the
5439	+	* given reducer to combine values, and the given basis as an
5440	+	* identity value.
5441	+	*
5442	+	* @param map the map
5443	+	* @param transformer a function returning the transformation
5444	+	* for an element
5445	+	* @param basis the identity (initial default value) for the reduction
5446	+	* @param reducer a commutative associative combining function
5447	+	* @return the task
5448	+	*/
5449	+	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5450	+	(ConcurrentHashMap<K,V> map,
5451	+	IntFunction<Map.Entry<K,V>> transformer,
5452	+	int basis,
5453	+	IntBinaryOperator reducer) {
5454	+	if (transformer == null || reducer == null)
5455	+	throw new NullPointerException();
5456	+	return new MapReduceEntriesToIntTask<K,V>
5457	+	(map, null, -1, null, transformer, basis, reducer);
5458	+	}
5459	+	}
5460	+
5461	+	// -------------------------------------------------------
5462	+
5463	+	/*
5464	+	* Task classes. Coded in a regular but ugly format/style to
5465	+	* simplify checks that each variant differs in the right way from
5466	+	* others. The null screenings exist because compilers cannot tell
5467	+	* that we've already null-checked task arguments, so we force
5468	+	* simplest hoisted bypass to help avoid convoluted traps.
5469	+	*/
5470	+
5471	+	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5472	+	extends Traverser<K,V,Void> {
5473	+	final Block<? super K> action;
5474	+	ForEachKeyTask
5475	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5476	+	Block<? super K> action) {
5477	+	super(m, p, b);
5478	+	this.action = action;
5479	+	}
5480	+	@SuppressWarnings("unchecked") public final void compute() {
5481	+	final Block<? super K> action;
5482	+	if ((action = this.action) != null) {
5483	+	for (int b; (b = preSplit()) > 0;)
5484	+	new ForEachKeyTask<K,V>(map, this, b, action).fork();
5485	+	while (advance() != null)
5486	+	action.accept((K)nextKey);
5487	+	propagateCompletion();
5488	+	}
5489	+	}
5490	+	}
5491	+
5492	+	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5493	+	extends Traverser<K,V,Void> {
5494	+	final Block<? super V> action;
5495	+	ForEachValueTask
5496	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5497	+	Block<? super V> action) {
5498	+	super(m, p, b);
5499	+	this.action = action;
5500	+	}
5501	+	@SuppressWarnings("unchecked") public final void compute() {
5502	+	final Block<? super V> action;
5503	+	if ((action = this.action) != null) {
5504	+	for (int b; (b = preSplit()) > 0;)
5505	+	new ForEachValueTask<K,V>(map, this, b, action).fork();
5506	+	V v;
5507	+	while ((v = advance()) != null)
5508	+	action.accept(v);
5509	+	propagateCompletion();
5510	+	}
5511	+	}
5512	+	}
5513	+
5514	+	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5515	+	extends Traverser<K,V,Void> {
5516	+	final Block<? super Entry<K,V>> action;
5517	+	ForEachEntryTask
5518	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5519	+	Block<? super Entry<K,V>> action) {
5520	+	super(m, p, b);
5521	+	this.action = action;
5522	+	}
5523	+	@SuppressWarnings("unchecked") public final void compute() {
5524	+	final Block<? super Entry<K,V>> action;
5525	+	if ((action = this.action) != null) {
5526	+	for (int b; (b = preSplit()) > 0;)
5527	+	new ForEachEntryTask<K,V>(map, this, b, action).fork();
5528	+	V v;
5529	+	while ((v = advance()) != null)
5530	+	action.accept(entryFor((K)nextKey, v));
5531	+	propagateCompletion();
5532	+	}
5533	+	}
5534	+	}
5535	+
5536	+	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5537	+	extends Traverser<K,V,Void> {
5538	+	final BiBlock<? super K, ? super V> action;
5539	+	ForEachMappingTask
5540	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5541	+	BiBlock<? super K,? super V> action) {
5542	+	super(m, p, b);
5543	+	this.action = action;
5544	+	}
5545	+	@SuppressWarnings("unchecked") public final void compute() {
5546	+	final BiBlock<? super K, ? super V> action;
5547	+	if ((action = this.action) != null) {
5548	+	for (int b; (b = preSplit()) > 0;)
5549	+	new ForEachMappingTask<K,V>(map, this, b, action).fork();
5550	+	V v;
5551	+	while ((v = advance()) != null)
5552	+	action.accept((K)nextKey, v);
5553	+	propagateCompletion();
5554	+	}
5555	+	}
5556	+	}
5557	+
5558	+	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5559	+	extends Traverser<K,V,Void> {
5560	+	final Function<? super K, ? extends U> transformer;
5561	+	final Block<? super U> action;
5562	+	ForEachTransformedKeyTask
5563	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5564	+	Function<? super K, ? extends U> transformer, Block<? super U> action) {
5565	+	super(m, p, b);
5566	+	this.transformer = transformer; this.action = action;
5567	+	}
5568	+	@SuppressWarnings("unchecked") public final void compute() {
5569	+	final Function<? super K, ? extends U> transformer;
5570	+	final Block<? super U> action;
5571	+	if ((transformer = this.transformer) != null &&
5572	+	(action = this.action) != null) {
5573	+	for (int b; (b = preSplit()) > 0;)
5574	+	new ForEachTransformedKeyTask<K,V,U>
5575	+	(map, this, b, transformer, action).fork();
5576	+	U u;
5577	+	while (advance() != null) {
5578	+	if ((u = transformer.apply((K)nextKey)) != null)
5579	+	action.accept(u);
5580	+	}
5581	+	propagateCompletion();
5582	+	}
5583	+	}
5584	+	}
5585	+
5586	+	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5587	+	extends Traverser<K,V,Void> {
5588	+	final Function<? super V, ? extends U> transformer;
5589	+	final Block<? super U> action;
5590	+	ForEachTransformedValueTask
5591	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5592	+	Function<? super V, ? extends U> transformer, Block<? super U> action) {
5593	+	super(m, p, b);
5594	+	this.transformer = transformer; this.action = action;
5595	+	}
5596	+	@SuppressWarnings("unchecked") public final void compute() {
5597	+	final Function<? super V, ? extends U> transformer;
5598	+	final Block<? super U> action;
5599	+	if ((transformer = this.transformer) != null &&
5600	+	(action = this.action) != null) {
5601	+	for (int b; (b = preSplit()) > 0;)
5602	+	new ForEachTransformedValueTask<K,V,U>
5603	+	(map, this, b, transformer, action).fork();
5604	+	V v; U u;
5605	+	while ((v = advance()) != null) {
5606	+	if ((u = transformer.apply(v)) != null)
5607	+	action.accept(u);
5608	+	}
5609	+	propagateCompletion();
5610	+	}
5611	+	}
5612	+	}
5613	+
5614	+	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5615	+	extends Traverser<K,V,Void> {
5616	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5617	+	final Block<? super U> action;
5618	+	ForEachTransformedEntryTask
5619	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5620	+	Function<Map.Entry<K,V>, ? extends U> transformer, Block<? super U> action) {
5621	+	super(m, p, b);
5622	+	this.transformer = transformer; this.action = action;
5623	+	}
5624	+	@SuppressWarnings("unchecked") public final void compute() {
5625	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5626	+	final Block<? super U> action;
5627	+	if ((transformer = this.transformer) != null &&
5628	+	(action = this.action) != null) {
5629	+	for (int b; (b = preSplit()) > 0;)
5630	+	new ForEachTransformedEntryTask<K,V,U>
5631	+	(map, this, b, transformer, action).fork();
5632	+	V v; U u;
5633	+	while ((v = advance()) != null) {
5634	+	if ((u = transformer.apply(entryFor((K)nextKey,
5635	+	v))) != null)
5636	+	action.accept(u);
5637	+	}
5638	+	propagateCompletion();
5639	+	}
5640	+	}
5641	+	}
5642	+
5643	+	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5644	+	extends Traverser<K,V,Void> {
5645	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5646	+	final Block<? super U> action;
5647	+	ForEachTransformedMappingTask
5648	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5649	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5650	+	Block<? super U> action) {
5651	+	super(m, p, b);
5652	+	this.transformer = transformer; this.action = action;
5653	+	}
5654	+	@SuppressWarnings("unchecked") public final void compute() {
5655	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5656	+	final Block<? super U> action;
5657	+	if ((transformer = this.transformer) != null &&
5658	+	(action = this.action) != null) {
5659	+	for (int b; (b = preSplit()) > 0;)
5660	+	new ForEachTransformedMappingTask<K,V,U>
5661	+	(map, this, b, transformer, action).fork();
5662	+	V v; U u;
5663	+	while ((v = advance()) != null) {
5664	+	if ((u = transformer.apply((K)nextKey, v)) != null)
5665	+	action.accept(u);
5666	+	}
5667	+	propagateCompletion();
5668	+	}
5669	+	}
5670	+	}
5671	+
5672	+	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5673	+	extends Traverser<K,V,U> {
5674	+	final Function<? super K, ? extends U> searchFunction;
5675	+	final AtomicReference<U> result;
5676	+	SearchKeysTask
5677	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5678	+	Function<? super K, ? extends U> searchFunction,
5679	+	AtomicReference<U> result) {
5680	+	super(m, p, b);
5681	+	this.searchFunction = searchFunction; this.result = result;
5682	+	}
5683	+	public final U getRawResult() { return result.get(); }
5684	+	@SuppressWarnings("unchecked") public final void compute() {
5685	+	final Function<? super K, ? extends U> searchFunction;
5686	+	final AtomicReference<U> result;
5687	+	if ((searchFunction = this.searchFunction) != null &&
5688	+	(result = this.result) != null) {
5689	+	for (int b;;) {
5690	+	if (result.get() != null)
5691	+	return;
5692	+	if ((b = preSplit()) <= 0)
5693	+	break;
5694	+	new SearchKeysTask<K,V,U>
5695	+	(map, this, b, searchFunction, result).fork();
5696	+	}
5697	+	while (result.get() == null) {
5698	+	U u;
5699	+	if (advance() == null) {
5700	+	propagateCompletion();
5701	+	break;
5702	+	}
5703	+	if ((u = searchFunction.apply((K)nextKey)) != null) {
5704	+	if (result.compareAndSet(null, u))
5705	+	quietlyCompleteRoot();
5706	+	break;
5707	+	}
5708	+	}
5709	+	}
5710	+	}
5711	+	}
5712	+
5713	+	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5714	+	extends Traverser<K,V,U> {
5715	+	final Function<? super V, ? extends U> searchFunction;
5716	+	final AtomicReference<U> result;
5717	+	SearchValuesTask
5718	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5719	+	Function<? super V, ? extends U> searchFunction,
5720	+	AtomicReference<U> result) {
5721	+	super(m, p, b);
5722	+	this.searchFunction = searchFunction; this.result = result;
5723	+	}
5724	+	public final U getRawResult() { return result.get(); }
5725	+	@SuppressWarnings("unchecked") public final void compute() {
5726	+	final Function<? super V, ? extends U> searchFunction;
5727	+	final AtomicReference<U> result;
5728	+	if ((searchFunction = this.searchFunction) != null &&
5729	+	(result = this.result) != null) {
5730	+	for (int b;;) {
5731	+	if (result.get() != null)
5732	+	return;
5733	+	if ((b = preSplit()) <= 0)
5734	+	break;
5735	+	new SearchValuesTask<K,V,U>
5736	+	(map, this, b, searchFunction, result).fork();
5737	+	}
5738	+	while (result.get() == null) {
5739	+	V v; U u;
5740	+	if ((v = advance()) == null) {
5741	+	propagateCompletion();
5742	+	break;
5743	+	}
5744	+	if ((u = searchFunction.apply(v)) != null) {
5745	+	if (result.compareAndSet(null, u))
5746	+	quietlyCompleteRoot();
5747	+	break;
5748	+	}
5749	+	}
5750	+	}
5751	+	}
5752	+	}
5753	+
5754	+	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5755	+	extends Traverser<K,V,U> {
5756	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5757	+	final AtomicReference<U> result;
5758	+	SearchEntriesTask
5759	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5760	+	Function<Entry<K,V>, ? extends U> searchFunction,
5761	+	AtomicReference<U> result) {
5762	+	super(m, p, b);
5763	+	this.searchFunction = searchFunction; this.result = result;
5764	+	}
5765	+	public final U getRawResult() { return result.get(); }
5766	+	@SuppressWarnings("unchecked") public final void compute() {
5767	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5768	+	final AtomicReference<U> result;
5769	+	if ((searchFunction = this.searchFunction) != null &&
5770	+	(result = this.result) != null) {
5771	+	for (int b;;) {
5772	+	if (result.get() != null)
5773	+	return;
5774	+	if ((b = preSplit()) <= 0)
5775	+	break;
5776	+	new SearchEntriesTask<K,V,U>
5777	+	(map, this, b, searchFunction, result).fork();
5778	+	}
5779	+	while (result.get() == null) {
5780	+	V v; U u;
5781	+	if ((v = advance()) == null) {
5782	+	propagateCompletion();
5783	+	break;
5784	+	}
5785	+	if ((u = searchFunction.apply(entryFor((K)nextKey,
5786	+	v))) != null) {
5787	+	if (result.compareAndSet(null, u))
5788	+	quietlyCompleteRoot();
5789	+	return;
5790	+	}
5791	+	}
5792	+	}
5793	+	}
5794	+	}
5795	+
5796	+	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
5797	+	extends Traverser<K,V,U> {
5798	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5799	+	final AtomicReference<U> result;
5800	+	SearchMappingsTask
5801	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5802	+	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5803	+	AtomicReference<U> result) {
5804	+	super(m, p, b);
5805	+	this.searchFunction = searchFunction; this.result = result;
5806	+	}
5807	+	public final U getRawResult() { return result.get(); }
5808	+	@SuppressWarnings("unchecked") public final void compute() {
5809	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5810	+	final AtomicReference<U> result;
5811	+	if ((searchFunction = this.searchFunction) != null &&
5812	+	(result = this.result) != null) {
5813	+	for (int b;;) {
5814	+	if (result.get() != null)
5815	+	return;
5816	+	if ((b = preSplit()) <= 0)
5817	+	break;
5818	+	new SearchMappingsTask<K,V,U>
5819	+	(map, this, b, searchFunction, result).fork();
5820	+	}
5821	+	while (result.get() == null) {
5822	+	V v; U u;
5823	+	if ((v = advance()) == null) {
5824	+	propagateCompletion();
5825	+	break;
5826	+	}
5827	+	if ((u = searchFunction.apply((K)nextKey, v)) != null) {
5828	+	if (result.compareAndSet(null, u))
5829	+	quietlyCompleteRoot();
5830	+	break;
5831	+	}
5832	+	}
5833	+	}
5834	+	}
5835	+	}
5836	+
5837	+	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
5838	+	extends Traverser<K,V,K> {
5839	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5840	+	K result;
5841	+	ReduceKeysTask<K,V> rights, nextRight;
5842	+	ReduceKeysTask
5843	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5844	+	ReduceKeysTask<K,V> nextRight,
5845	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5846	+	super(m, p, b); this.nextRight = nextRight;
5847	+	this.reducer = reducer;
5848	+	}
5849	+	public final K getRawResult() { return result; }
5850	+	@SuppressWarnings("unchecked") public final void compute() {
5851	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5852	+	if ((reducer = this.reducer) != null) {
5853	+	for (int b; (b = preSplit()) > 0;)
5854	+	(rights = new ReduceKeysTask<K,V>
5855	+	(map, this, b, rights, reducer)).fork();
5856	+	K r = null;
5857	+	while (advance() != null) {
5858	+	K u = (K)nextKey;
5859	+	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5860	+	}
5861	+	result = r;
5862	+	CountedCompleter<?> c;
5863	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5864	+	ReduceKeysTask<K,V>
5865	+	t = (ReduceKeysTask<K,V>)c,
5866	+	s = t.rights;
5867	+	while (s != null) {
5868	+	K tr, sr;
5869	+	if ((sr = s.result) != null)
5870	+	t.result = (((tr = t.result) == null) ? sr :
5871	+	reducer.apply(tr, sr));
5872	+	s = t.rights = s.nextRight;
5873	+	}
5874	+	}
5875	+	}
5876	+	}
5877	+	}
5878	+
5879	+	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
5880	+	extends Traverser<K,V,V> {
5881	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5882	+	V result;
5883	+	ReduceValuesTask<K,V> rights, nextRight;
5884	+	ReduceValuesTask
5885	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5886	+	ReduceValuesTask<K,V> nextRight,
5887	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5888	+	super(m, p, b); this.nextRight = nextRight;
5889	+	this.reducer = reducer;
5890	+	}
5891	+	public final V getRawResult() { return result; }
5892	+	@SuppressWarnings("unchecked") public final void compute() {
5893	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5894	+	if ((reducer = this.reducer) != null) {
5895	+	for (int b; (b = preSplit()) > 0;)
5896	+	(rights = new ReduceValuesTask<K,V>
5897	+	(map, this, b, rights, reducer)).fork();
5898	+	V r = null, v;
5899	+	while ((v = advance()) != null)
5900	+	r = (r == null) ? v : reducer.apply(r, v);
5901	+	result = r;
5902	+	CountedCompleter<?> c;
5903	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5904	+	ReduceValuesTask<K,V>
5905	+	t = (ReduceValuesTask<K,V>)c,
5906	+	s = t.rights;
5907	+	while (s != null) {
5908	+	V tr, sr;
5909	+	if ((sr = s.result) != null)
5910	+	t.result = (((tr = t.result) == null) ? sr :
5911	+	reducer.apply(tr, sr));
5912	+	s = t.rights = s.nextRight;
5913	+	}
5914	+	}
5915	+	}
5916	+	}
5917	+	}
5918	+
5919	+	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
5920	+	extends Traverser<K,V,Map.Entry<K,V>> {
5921	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5922	+	Map.Entry<K,V> result;
5923	+	ReduceEntriesTask<K,V> rights, nextRight;
5924	+	ReduceEntriesTask
5925	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5926	+	ReduceEntriesTask<K,V> nextRight,
5927	+	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5928	+	super(m, p, b); this.nextRight = nextRight;
5929	+	this.reducer = reducer;
5930	+	}
5931	+	public final Map.Entry<K,V> getRawResult() { return result; }
5932	+	@SuppressWarnings("unchecked") public final void compute() {
5933	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5934	+	if ((reducer = this.reducer) != null) {
5935	+	for (int b; (b = preSplit()) > 0;)
5936	+	(rights = new ReduceEntriesTask<K,V>
5937	+	(map, this, b, rights, reducer)).fork();
5938	+	Map.Entry<K,V> r = null;
5939	+	V v;
5940	+	while ((v = advance()) != null) {
5941	+	Map.Entry<K,V> u = entryFor((K)nextKey, v);
5942	+	r = (r == null) ? u : reducer.apply(r, u);
5943	+	}
5944	+	result = r;
5945	+	CountedCompleter<?> c;
5946	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5947	+	ReduceEntriesTask<K,V>
5948	+	t = (ReduceEntriesTask<K,V>)c,
5949	+	s = t.rights;
5950	+	while (s != null) {
5951	+	Map.Entry<K,V> tr, sr;
5952	+	if ((sr = s.result) != null)
5953	+	t.result = (((tr = t.result) == null) ? sr :
5954	+	reducer.apply(tr, sr));
5955	+	s = t.rights = s.nextRight;
5956	+	}
5957	+	}
5958	+	}
5959	+	}
5960	+	}
5961	+
5962	+	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
5963	+	extends Traverser<K,V,U> {
5964	+	final Function<? super K, ? extends U> transformer;
5965	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5966	+	U result;
5967	+	MapReduceKeysTask<K,V,U> rights, nextRight;
5968	+	MapReduceKeysTask
5969	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5970	+	MapReduceKeysTask<K,V,U> nextRight,
5971	+	Function<? super K, ? extends U> transformer,
5972	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5973	+	super(m, p, b); this.nextRight = nextRight;
5974	+	this.transformer = transformer;
5975	+	this.reducer = reducer;
5976	+	}
5977	+	public final U getRawResult() { return result; }
5978	+	@SuppressWarnings("unchecked") public final void compute() {
5979	+	final Function<? super K, ? extends U> transformer;
5980	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5981	+	if ((transformer = this.transformer) != null &&
5982	+	(reducer = this.reducer) != null) {
5983	+	for (int b; (b = preSplit()) > 0;)
5984	+	(rights = new MapReduceKeysTask<K,V,U>
5985	+	(map, this, b, rights, transformer, reducer)).fork();
5986	+	U r = null, u;
5987	+	while (advance() != null) {
5988	+	if ((u = transformer.apply((K)nextKey)) != null)
5989	+	r = (r == null) ? u : reducer.apply(r, u);
5990	+	}
5991	+	result = r;
5992	+	CountedCompleter<?> c;
5993	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5994	+	MapReduceKeysTask<K,V,U>
5995	+	t = (MapReduceKeysTask<K,V,U>)c,
5996	+	s = t.rights;
5997	+	while (s != null) {
5998	+	U tr, sr;
5999	+	if ((sr = s.result) != null)
6000	+	t.result = (((tr = t.result) == null) ? sr :
6001	+	reducer.apply(tr, sr));
6002	+	s = t.rights = s.nextRight;
6003	+	}
6004	+	}
6005	+	}
6006	+	}
6007	+	}
6008	+
6009	+	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
6010	+	extends Traverser<K,V,U> {
6011	+	final Function<? super V, ? extends U> transformer;
6012	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6013	+	U result;
6014	+	MapReduceValuesTask<K,V,U> rights, nextRight;
6015	+	MapReduceValuesTask
6016	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6017	+	MapReduceValuesTask<K,V,U> nextRight,
6018	+	Function<? super V, ? extends U> transformer,
6019	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6020	+	super(m, p, b); this.nextRight = nextRight;
6021	+	this.transformer = transformer;
6022	+	this.reducer = reducer;
6023	+	}
6024	+	public final U getRawResult() { return result; }
6025	+	@SuppressWarnings("unchecked") public final void compute() {
6026	+	final Function<? super V, ? extends U> transformer;
6027	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6028	+	if ((transformer = this.transformer) != null &&
6029	+	(reducer = this.reducer) != null) {
6030	+	for (int b; (b = preSplit()) > 0;)
6031	+	(rights = new MapReduceValuesTask<K,V,U>
6032	+	(map, this, b, rights, transformer, reducer)).fork();
6033	+	U r = null, u;
6034	+	V v;
6035	+	while ((v = advance()) != null) {
6036	+	if ((u = transformer.apply(v)) != null)
6037	+	r = (r == null) ? u : reducer.apply(r, u);
6038	+	}
6039	+	result = r;
6040	+	CountedCompleter<?> c;
6041	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6042	+	MapReduceValuesTask<K,V,U>
6043	+	t = (MapReduceValuesTask<K,V,U>)c,
6044	+	s = t.rights;
6045	+	while (s != null) {
6046	+	U tr, sr;
6047	+	if ((sr = s.result) != null)
6048	+	t.result = (((tr = t.result) == null) ? sr :
6049	+	reducer.apply(tr, sr));
6050	+	s = t.rights = s.nextRight;
6051	+	}
6052	+	}
6053	+	}
6054	+	}
6055	+	}
6056	+
6057	+	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
6058	+	extends Traverser<K,V,U> {
6059	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
6060	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6061	+	U result;
6062	+	MapReduceEntriesTask<K,V,U> rights, nextRight;
6063	+	MapReduceEntriesTask
6064	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6065	+	MapReduceEntriesTask<K,V,U> nextRight,
6066	+	Function<Map.Entry<K,V>, ? extends U> transformer,
6067	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6068	+	super(m, p, b); this.nextRight = nextRight;
6069	+	this.transformer = transformer;
6070	+	this.reducer = reducer;
6071	+	}
6072	+	public final U getRawResult() { return result; }
6073	+	@SuppressWarnings("unchecked") public final void compute() {
6074	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
6075	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6076	+	if ((transformer = this.transformer) != null &&
6077	+	(reducer = this.reducer) != null) {
6078	+	for (int b; (b = preSplit()) > 0;)
6079	+	(rights = new MapReduceEntriesTask<K,V,U>
6080	+	(map, this, b, rights, transformer, reducer)).fork();
6081	+	U r = null, u;
6082	+	V v;
6083	+	while ((v = advance()) != null) {
6084	+	if ((u = transformer.apply(entryFor((K)nextKey,
6085	+	v))) != null)
6086	+	r = (r == null) ? u : reducer.apply(r, u);
6087	+	}
6088	+	result = r;
6089	+	CountedCompleter<?> c;
6090	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6091	+	MapReduceEntriesTask<K,V,U>
6092	+	t = (MapReduceEntriesTask<K,V,U>)c,
6093	+	s = t.rights;
6094	+	while (s != null) {
6095	+	U tr, sr;
6096	+	if ((sr = s.result) != null)
6097	+	t.result = (((tr = t.result) == null) ? sr :
6098	+	reducer.apply(tr, sr));
6099	+	s = t.rights = s.nextRight;
6100	+	}
6101	+	}
6102	+	}
6103	+	}
6104	+	}
6105	+
6106	+	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6107	+	extends Traverser<K,V,U> {
6108	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
6109	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6110	+	U result;
6111	+	MapReduceMappingsTask<K,V,U> rights, nextRight;
6112	+	MapReduceMappingsTask
6113	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6114	+	MapReduceMappingsTask<K,V,U> nextRight,
6115	+	BiFunction<? super K, ? super V, ? extends U> transformer,
6116	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
6117	+	super(m, p, b); this.nextRight = nextRight;
6118	+	this.transformer = transformer;
6119	+	this.reducer = reducer;
6120	+	}
6121	+	public final U getRawResult() { return result; }
6122	+	@SuppressWarnings("unchecked") public final void compute() {
6123	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
6124	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
6125	+	if ((transformer = this.transformer) != null &&
6126	+	(reducer = this.reducer) != null) {
6127	+	for (int b; (b = preSplit()) > 0;)
6128	+	(rights = new MapReduceMappingsTask<K,V,U>
6129	+	(map, this, b, rights, transformer, reducer)).fork();
6130	+	U r = null, u;
6131	+	V v;
6132	+	while ((v = advance()) != null) {
6133	+	if ((u = transformer.apply((K)nextKey, v)) != null)
6134	+	r = (r == null) ? u : reducer.apply(r, u);
6135	+	}
6136	+	result = r;
6137	+	CountedCompleter<?> c;
6138	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6139	+	MapReduceMappingsTask<K,V,U>
6140	+	t = (MapReduceMappingsTask<K,V,U>)c,
6141	+	s = t.rights;
6142	+	while (s != null) {
6143	+	U tr, sr;
6144	+	if ((sr = s.result) != null)
6145	+	t.result = (((tr = t.result) == null) ? sr :
6146	+	reducer.apply(tr, sr));
6147	+	s = t.rights = s.nextRight;
6148	+	}
6149	+	}
6150	+	}
6151	+	}
6152	+	}
6153	+
6154	+	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6155	+	extends Traverser<K,V,Double> {
6156	+	final DoubleFunction<? super K> transformer;
6157	+	final DoubleBinaryOperator reducer;
6158	+	final double basis;
6159	+	double result;
6160	+	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6161	+	MapReduceKeysToDoubleTask
6162	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6163	+	MapReduceKeysToDoubleTask<K,V> nextRight,
6164	+	DoubleFunction<? super K> transformer,
6165	+	double basis,
6166	+	DoubleBinaryOperator reducer) {
6167	+	super(m, p, b); this.nextRight = nextRight;
6168	+	this.transformer = transformer;
6169	+	this.basis = basis; this.reducer = reducer;
6170	+	}
6171	+	public final Double getRawResult() { return result; }
6172	+	@SuppressWarnings("unchecked") public final void compute() {
6173	+	final DoubleFunction<? super K> transformer;
6174	+	final DoubleBinaryOperator reducer;
6175	+	if ((transformer = this.transformer) != null &&
6176	+	(reducer = this.reducer) != null) {
6177	+	double r = this.basis;
6178	+	for (int b; (b = preSplit()) > 0;)
6179	+	(rights = new MapReduceKeysToDoubleTask<K,V>
6180	+	(map, this, b, rights, transformer, r, reducer)).fork();
6181	+	while (advance() != null)
6182	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)nextKey));
6183	+	result = r;
6184	+	CountedCompleter<?> c;
6185	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6186	+	MapReduceKeysToDoubleTask<K,V>
6187	+	t = (MapReduceKeysToDoubleTask<K,V>)c,
6188	+	s = t.rights;
6189	+	while (s != null) {
6190	+	t.result = reducer.applyAsDouble(t.result, s.result);
6191	+	s = t.rights = s.nextRight;
6192	+	}
6193	+	}
6194	+	}
6195	+	}
6196	+	}
6197	+
6198	+	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6199	+	extends Traverser<K,V,Double> {
6200	+	final DoubleFunction<? super V> transformer;
6201	+	final DoubleBinaryOperator reducer;
6202	+	final double basis;
6203	+	double result;
6204	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6205	+	MapReduceValuesToDoubleTask
6206	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6207	+	MapReduceValuesToDoubleTask<K,V> nextRight,
6208	+	DoubleFunction<? super V> transformer,
6209	+	double basis,
6210	+	DoubleBinaryOperator reducer) {
6211	+	super(m, p, b); this.nextRight = nextRight;
6212	+	this.transformer = transformer;
6213	+	this.basis = basis; this.reducer = reducer;
6214	+	}
6215	+	public final Double getRawResult() { return result; }
6216	+	@SuppressWarnings("unchecked") public final void compute() {
6217	+	final DoubleFunction<? super V> transformer;
6218	+	final DoubleBinaryOperator reducer;
6219	+	if ((transformer = this.transformer) != null &&
6220	+	(reducer = this.reducer) != null) {
6221	+	double r = this.basis;
6222	+	for (int b; (b = preSplit()) > 0;)
6223	+	(rights = new MapReduceValuesToDoubleTask<K,V>
6224	+	(map, this, b, rights, transformer, r, reducer)).fork();
6225	+	V v;
6226	+	while ((v = advance()) != null)
6227	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
6228	+	result = r;
6229	+	CountedCompleter<?> c;
6230	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6231	+	MapReduceValuesToDoubleTask<K,V>
6232	+	t = (MapReduceValuesToDoubleTask<K,V>)c,
6233	+	s = t.rights;
6234	+	while (s != null) {
6235	+	t.result = reducer.applyAsDouble(t.result, s.result);
6236	+	s = t.rights = s.nextRight;
6237	+	}
6238	+	}
6239	+	}
6240	+	}
6241	+	}
6242	+
6243	+	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6244	+	extends Traverser<K,V,Double> {
6245	+	final DoubleFunction<Map.Entry<K,V>> transformer;
6246	+	final DoubleBinaryOperator reducer;
6247	+	final double basis;
6248	+	double result;
6249	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6250	+	MapReduceEntriesToDoubleTask
6251	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6252	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
6253	+	DoubleFunction<Map.Entry<K,V>> transformer,
6254	+	double basis,
6255	+	DoubleBinaryOperator reducer) {
6256	+	super(m, p, b); this.nextRight = nextRight;
6257	+	this.transformer = transformer;
6258	+	this.basis = basis; this.reducer = reducer;
6259	+	}
6260	+	public final Double getRawResult() { return result; }
6261	+	@SuppressWarnings("unchecked") public final void compute() {
6262	+	final DoubleFunction<Map.Entry<K,V>> transformer;
6263	+	final DoubleBinaryOperator reducer;
6264	+	if ((transformer = this.transformer) != null &&
6265	+	(reducer = this.reducer) != null) {
6266	+	double r = this.basis;
6267	+	for (int b; (b = preSplit()) > 0;)
6268	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
6269	+	(map, this, b, rights, transformer, r, reducer)).fork();
6270	+	V v;
6271	+	while ((v = advance()) != null)
6272	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor((K)nextKey,
6273	+	v)));
6274	+	result = r;
6275	+	CountedCompleter<?> c;
6276	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6277	+	MapReduceEntriesToDoubleTask<K,V>
6278	+	t = (MapReduceEntriesToDoubleTask<K,V>)c,
6279	+	s = t.rights;
6280	+	while (s != null) {
6281	+	t.result = reducer.applyAsDouble(t.result, s.result);
6282	+	s = t.rights = s.nextRight;
6283	+	}
6284	+	}
6285	+	}
6286	+	}
6287	+	}
6288	+
6289	+	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6290	+	extends Traverser<K,V,Double> {
6291	+	final DoubleBiFunction<? super K, ? super V> transformer;
6292	+	final DoubleBinaryOperator reducer;
6293	+	final double basis;
6294	+	double result;
6295	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6296	+	MapReduceMappingsToDoubleTask
6297	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6298	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
6299	+	DoubleBiFunction<? super K, ? super V> transformer,
6300	+	double basis,
6301	+	DoubleBinaryOperator reducer) {
6302	+	super(m, p, b); this.nextRight = nextRight;
6303	+	this.transformer = transformer;
6304	+	this.basis = basis; this.reducer = reducer;
6305	+	}
6306	+	public final Double getRawResult() { return result; }
6307	+	@SuppressWarnings("unchecked") public final void compute() {
6308	+	final DoubleBiFunction<? super K, ? super V> transformer;
6309	+	final DoubleBinaryOperator reducer;
6310	+	if ((transformer = this.transformer) != null &&
6311	+	(reducer = this.reducer) != null) {
6312	+	double r = this.basis;
6313	+	for (int b; (b = preSplit()) > 0;)
6314	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
6315	+	(map, this, b, rights, transformer, r, reducer)).fork();
6316	+	V v;
6317	+	while ((v = advance()) != null)
6318	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)nextKey, v));
6319	+	result = r;
6320	+	CountedCompleter<?> c;
6321	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6322	+	MapReduceMappingsToDoubleTask<K,V>
6323	+	t = (MapReduceMappingsToDoubleTask<K,V>)c,
6324	+	s = t.rights;
6325	+	while (s != null) {
6326	+	t.result = reducer.applyAsDouble(t.result, s.result);
6327	+	s = t.rights = s.nextRight;
6328	+	}
6329	+	}
6330	+	}
6331	+	}
6332	+	}
6333	+
6334	+	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6335	+	extends Traverser<K,V,Long> {
6336	+	final LongFunction<? super K> transformer;
6337	+	final LongBinaryOperator reducer;
6338	+	final long basis;
6339	+	long result;
6340	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
6341	+	MapReduceKeysToLongTask
6342	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6343	+	MapReduceKeysToLongTask<K,V> nextRight,
6344	+	LongFunction<? super K> transformer,
6345	+	long basis,
6346	+	LongBinaryOperator reducer) {
6347	+	super(m, p, b); this.nextRight = nextRight;
6348	+	this.transformer = transformer;
6349	+	this.basis = basis; this.reducer = reducer;
6350	+	}
6351	+	public final Long getRawResult() { return result; }
6352	+	@SuppressWarnings("unchecked") public final void compute() {
6353	+	final LongFunction<? super K> transformer;
6354	+	final LongBinaryOperator reducer;
6355	+	if ((transformer = this.transformer) != null &&
6356	+	(reducer = this.reducer) != null) {
6357	+	long r = this.basis;
6358	+	for (int b; (b = preSplit()) > 0;)
6359	+	(rights = new MapReduceKeysToLongTask<K,V>
6360	+	(map, this, b, rights, transformer, r, reducer)).fork();
6361	+	while (advance() != null)
6362	+	r = reducer.applyAsLong(r, transformer.applyAsLong((K)nextKey));
6363	+	result = r;
6364	+	CountedCompleter<?> c;
6365	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6366	+	MapReduceKeysToLongTask<K,V>
6367	+	t = (MapReduceKeysToLongTask<K,V>)c,
6368	+	s = t.rights;
6369	+	while (s != null) {
6370	+	t.result = reducer.applyAsLong(t.result, s.result);
6371	+	s = t.rights = s.nextRight;
6372	+	}
6373	+	}
6374	+	}
6375	+	}
6376	+	}
6377	+
6378	+	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6379	+	extends Traverser<K,V,Long> {
6380	+	final LongFunction<? super V> transformer;
6381	+	final LongBinaryOperator reducer;
6382	+	final long basis;
6383	+	long result;
6384	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
6385	+	MapReduceValuesToLongTask
6386	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6387	+	MapReduceValuesToLongTask<K,V> nextRight,
6388	+	LongFunction<? super V> transformer,
6389	+	long basis,
6390	+	LongBinaryOperator reducer) {
6391	+	super(m, p, b); this.nextRight = nextRight;
6392	+	this.transformer = transformer;
6393	+	this.basis = basis; this.reducer = reducer;
6394	+	}
6395	+	public final Long getRawResult() { return result; }
6396	+	@SuppressWarnings("unchecked") public final void compute() {
6397	+	final LongFunction<? super V> transformer;
6398	+	final LongBinaryOperator reducer;
6399	+	if ((transformer = this.transformer) != null &&
6400	+	(reducer = this.reducer) != null) {
6401	+	long r = this.basis;
6402	+	for (int b; (b = preSplit()) > 0;)
6403	+	(rights = new MapReduceValuesToLongTask<K,V>
6404	+	(map, this, b, rights, transformer, r, reducer)).fork();
6405	+	V v;
6406	+	while ((v = advance()) != null)
6407	+	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
6408	+	result = r;
6409	+	CountedCompleter<?> c;
6410	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6411	+	MapReduceValuesToLongTask<K,V>
6412	+	t = (MapReduceValuesToLongTask<K,V>)c,
6413	+	s = t.rights;
6414	+	while (s != null) {
6415	+	t.result = reducer.applyAsLong(t.result, s.result);
6416	+	s = t.rights = s.nextRight;
6417	+	}
6418	+	}
6419	+	}
6420	+	}
6421	+	}
6422	+
6423	+	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6424	+	extends Traverser<K,V,Long> {
6425	+	final LongFunction<Map.Entry<K,V>> transformer;
6426	+	final LongBinaryOperator reducer;
6427	+	final long basis;
6428	+	long result;
6429	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6430	+	MapReduceEntriesToLongTask
6431	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6432	+	MapReduceEntriesToLongTask<K,V> nextRight,
6433	+	LongFunction<Map.Entry<K,V>> transformer,
6434	+	long basis,
6435	+	LongBinaryOperator reducer) {
6436	+	super(m, p, b); this.nextRight = nextRight;
6437	+	this.transformer = transformer;
6438	+	this.basis = basis; this.reducer = reducer;
6439	+	}
6440	+	public final Long getRawResult() { return result; }
6441	+	@SuppressWarnings("unchecked") public final void compute() {
6442	+	final LongFunction<Map.Entry<K,V>> transformer;
6443	+	final LongBinaryOperator reducer;
6444	+	if ((transformer = this.transformer) != null &&
6445	+	(reducer = this.reducer) != null) {
6446	+	long r = this.basis;
6447	+	for (int b; (b = preSplit()) > 0;)
6448	+	(rights = new MapReduceEntriesToLongTask<K,V>
6449	+	(map, this, b, rights, transformer, r, reducer)).fork();
6450	+	V v;
6451	+	while ((v = advance()) != null)
6452	+	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor((K)nextKey, v)));
6453	+	result = r;
6454	+	CountedCompleter<?> c;
6455	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6456	+	MapReduceEntriesToLongTask<K,V>
6457	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6458	+	s = t.rights;
6459	+	while (s != null) {
6460	+	t.result = reducer.applyAsLong(t.result, s.result);
6461	+	s = t.rights = s.nextRight;
6462	+	}
6463	+	}
6464	+	}
6465	+	}
6466	+	}
6467	+
6468	+	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6469	+	extends Traverser<K,V,Long> {
6470	+	final LongBiFunction<? super K, ? super V> transformer;
6471	+	final LongBinaryOperator reducer;
6472	+	final long basis;
6473	+	long result;
6474	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6475	+	MapReduceMappingsToLongTask
6476	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6477	+	MapReduceMappingsToLongTask<K,V> nextRight,
6478	+	LongBiFunction<? super K, ? super V> transformer,
6479	+	long basis,
6480	+	LongBinaryOperator reducer) {
6481	+	super(m, p, b); this.nextRight = nextRight;
6482	+	this.transformer = transformer;
6483	+	this.basis = basis; this.reducer = reducer;
6484	+	}
6485	+	public final Long getRawResult() { return result; }
6486	+	@SuppressWarnings("unchecked") public final void compute() {
6487	+	final LongBiFunction<? super K, ? super V> transformer;
6488	+	final LongBinaryOperator reducer;
6489	+	if ((transformer = this.transformer) != null &&
6490	+	(reducer = this.reducer) != null) {
6491	+	long r = this.basis;
6492	+	for (int b; (b = preSplit()) > 0;)
6493	+	(rights = new MapReduceMappingsToLongTask<K,V>
6494	+	(map, this, b, rights, transformer, r, reducer)).fork();
6495	+	V v;
6496	+	while ((v = advance()) != null)
6497	+	r = reducer.applyAsLong(r, transformer.applyAsLong((K)nextKey, v));
6498	+	result = r;
6499	+	CountedCompleter<?> c;
6500	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6501	+	MapReduceMappingsToLongTask<K,V>
6502	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6503	+	s = t.rights;
6504	+	while (s != null) {
6505	+	t.result = reducer.applyAsLong(t.result, s.result);
6506	+	s = t.rights = s.nextRight;
6507	+	}
6508	+	}
6509	+	}
6510	+	}
6511	+	}
6512	+
6513	+	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6514	+	extends Traverser<K,V,Integer> {
6515	+	final IntFunction<? super K> transformer;
6516	+	final IntBinaryOperator reducer;
6517	+	final int basis;
6518	+	int result;
6519	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6520	+	MapReduceKeysToIntTask
6521	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6522	+	MapReduceKeysToIntTask<K,V> nextRight,
6523	+	IntFunction<? super K> transformer,
6524	+	int basis,
6525	+	IntBinaryOperator reducer) {
6526	+	super(m, p, b); this.nextRight = nextRight;
6527	+	this.transformer = transformer;
6528	+	this.basis = basis; this.reducer = reducer;
6529	+	}
6530	+	public final Integer getRawResult() { return result; }
6531	+	@SuppressWarnings("unchecked") public final void compute() {
6532	+	final IntFunction<? super K> transformer;
6533	+	final IntBinaryOperator reducer;
6534	+	if ((transformer = this.transformer) != null &&
6535	+	(reducer = this.reducer) != null) {
6536	+	int r = this.basis;
6537	+	for (int b; (b = preSplit()) > 0;)
6538	+	(rights = new MapReduceKeysToIntTask<K,V>
6539	+	(map, this, b, rights, transformer, r, reducer)).fork();
6540	+	while (advance() != null)
6541	+	r = reducer.applyAsInt(r, transformer.applyAsInt((K)nextKey));
6542	+	result = r;
6543	+	CountedCompleter<?> c;
6544	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6545	+	MapReduceKeysToIntTask<K,V>
6546	+	t = (MapReduceKeysToIntTask<K,V>)c,
6547	+	s = t.rights;
6548	+	while (s != null) {
6549	+	t.result = reducer.applyAsInt(t.result, s.result);
6550	+	s = t.rights = s.nextRight;
6551	+	}
6552	+	}
6553	+	}
6554	+	}
6555	+	}
6556	+
6557	+	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6558	+	extends Traverser<K,V,Integer> {
6559	+	final IntFunction<? super V> transformer;
6560	+	final IntBinaryOperator reducer;
6561	+	final int basis;
6562	+	int result;
6563	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6564	+	MapReduceValuesToIntTask
6565	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6566	+	MapReduceValuesToIntTask<K,V> nextRight,
6567	+	IntFunction<? super V> transformer,
6568	+	int basis,
6569	+	IntBinaryOperator reducer) {
6570	+	super(m, p, b); this.nextRight = nextRight;
6571	+	this.transformer = transformer;
6572	+	this.basis = basis; this.reducer = reducer;
6573	+	}
6574	+	public final Integer getRawResult() { return result; }
6575	+	@SuppressWarnings("unchecked") public final void compute() {
6576	+	final IntFunction<? super V> transformer;
6577	+	final IntBinaryOperator reducer;
6578	+	if ((transformer = this.transformer) != null &&
6579	+	(reducer = this.reducer) != null) {
6580	+	int r = this.basis;
6581	+	for (int b; (b = preSplit()) > 0;)
6582	+	(rights = new MapReduceValuesToIntTask<K,V>
6583	+	(map, this, b, rights, transformer, r, reducer)).fork();
6584	+	V v;
6585	+	while ((v = advance()) != null)
6586	+	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
6587	+	result = r;
6588	+	CountedCompleter<?> c;
6589	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6590	+	MapReduceValuesToIntTask<K,V>
6591	+	t = (MapReduceValuesToIntTask<K,V>)c,
6592	+	s = t.rights;
6593	+	while (s != null) {
6594	+	t.result = reducer.applyAsInt(t.result, s.result);
6595	+	s = t.rights = s.nextRight;
6596	+	}
6597	+	}
6598	+	}
6599	+	}
6600	+	}
6601	+
6602	+	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6603	+	extends Traverser<K,V,Integer> {
6604	+	final IntFunction<Map.Entry<K,V>> transformer;
6605	+	final IntBinaryOperator reducer;
6606	+	final int basis;
6607	+	int result;
6608	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6609	+	MapReduceEntriesToIntTask
6610	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6611	+	MapReduceEntriesToIntTask<K,V> nextRight,
6612	+	IntFunction<Map.Entry<K,V>> transformer,
6613	+	int basis,
6614	+	IntBinaryOperator reducer) {
6615	+	super(m, p, b); this.nextRight = nextRight;
6616	+	this.transformer = transformer;
6617	+	this.basis = basis; this.reducer = reducer;
6618	+	}
6619	+	public final Integer getRawResult() { return result; }
6620	+	@SuppressWarnings("unchecked") public final void compute() {
6621	+	final IntFunction<Map.Entry<K,V>> transformer;
6622	+	final IntBinaryOperator reducer;
6623	+	if ((transformer = this.transformer) != null &&
6624	+	(reducer = this.reducer) != null) {
6625	+	int r = this.basis;
6626	+	for (int b; (b = preSplit()) > 0;)
6627	+	(rights = new MapReduceEntriesToIntTask<K,V>
6628	+	(map, this, b, rights, transformer, r, reducer)).fork();
6629	+	V v;
6630	+	while ((v = advance()) != null)
6631	+	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor((K)nextKey,
6632	+	v)));
6633	+	result = r;
6634	+	CountedCompleter<?> c;
6635	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6636	+	MapReduceEntriesToIntTask<K,V>
6637	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6638	+	s = t.rights;
6639	+	while (s != null) {
6640	+	t.result = reducer.applyAsInt(t.result, s.result);
6641	+	s = t.rights = s.nextRight;
6642	+	}
6643	+	}
6644	+	}
6645	+	}
6646	+	}
6647	+
6648	+	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6649	+	extends Traverser<K,V,Integer> {
6650	+	final IntBiFunction<? super K, ? super V> transformer;
6651	+	final IntBinaryOperator reducer;
6652	+	final int basis;
6653	+	int result;
6654	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6655	+	MapReduceMappingsToIntTask
6656	+	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6657	+	MapReduceMappingsToIntTask<K,V> nextRight,
6658	+	IntBiFunction<? super K, ? super V> transformer,
6659	+	int basis,
6660	+	IntBinaryOperator reducer) {
6661	+	super(m, p, b); this.nextRight = nextRight;
6662	+	this.transformer = transformer;
6663	+	this.basis = basis; this.reducer = reducer;
6664	+	}
6665	+	public final Integer getRawResult() { return result; }
6666	+	@SuppressWarnings("unchecked") public final void compute() {
6667	+	final IntBiFunction<? super K, ? super V> transformer;
6668	+	final IntBinaryOperator reducer;
6669	+	if ((transformer = this.transformer) != null &&
6670	+	(reducer = this.reducer) != null) {
6671	+	int r = this.basis;
6672	+	for (int b; (b = preSplit()) > 0;)
6673	+	(rights = new MapReduceMappingsToIntTask<K,V>
6674	+	(map, this, b, rights, transformer, r, reducer)).fork();
6675	+	V v;
6676	+	while ((v = advance()) != null)
6677	+	r = reducer.applyAsInt(r, transformer.applyAsInt((K)nextKey, v));
6678	+	result = r;
6679	+	CountedCompleter<?> c;
6680	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6681	+	MapReduceMappingsToIntTask<K,V>
6682	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6683	+	s = t.rights;
6684	+	while (s != null) {
6685	+	t.result = reducer.applyAsInt(t.result, s.result);
6686	+	s = t.rights = s.nextRight;
6687	+	}
6688	+	}
6689	+	}
6690	+	}
6691	+	}
6692	+
6693	+	// Unsafe mechanics
6694	+	private static final sun.misc.Unsafe U;
6695	+	private static final long SIZECTL;
6696	+	private static final long TRANSFERINDEX;
6697	+	private static final long TRANSFERORIGIN;
6698	+	private static final long BASECOUNT;
6699	+	private static final long CELLSBUSY;
6700	+	private static final long CELLVALUE;
6701	+	private static final long ABASE;
6702	+	private static final int ASHIFT;
6703	+
6704	+	static {
6705	+	int ss;
6706	+	try {
6707	+	U = sun.misc.Unsafe.getUnsafe();
6708	+	Class<?> k = ConcurrentHashMap.class;
6709	+	SIZECTL = U.objectFieldOffset
6710	+	(k.getDeclaredField("sizeCtl"));
6711	+	TRANSFERINDEX = U.objectFieldOffset
6712	+	(k.getDeclaredField("transferIndex"));
6713	+	TRANSFERORIGIN = U.objectFieldOffset
6714	+	(k.getDeclaredField("transferOrigin"));
6715	+	BASECOUNT = U.objectFieldOffset
6716	+	(k.getDeclaredField("baseCount"));
6717	+	CELLSBUSY = U.objectFieldOffset
6718	+	(k.getDeclaredField("cellsBusy"));
6719	+	Class<?> ck = Cell.class;
6720	+	CELLVALUE = U.objectFieldOffset
6721	+	(ck.getDeclaredField("value"));
6722	+	Class<?> sc = Node[].class;
6723	+	ABASE = U.arrayBaseOffset(sc);
6724	+	ss = U.arrayIndexScale(sc);
6725	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(ss);
6726	+	} catch (Exception e) {
6727	+	throw new Error(e);
6728	+	}
6729	+	if ((ss & (ss-1)) != 0)
6730	+	throw new Error("data type scale not a power of two");
6731	+	}
6732	+
6733	+	}

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