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Revision 1.33 by dl, Sat Dec 6 00:16:20 2003 UTC vs.
Revision 1.221 by jsr166, Wed Jun 5 16:00:55 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.io.Serializable;
9	<	import java.io.IOException;
10	<	import java.io.ObjectInputStream;
11	<	import java.io.ObjectOutputStream;
9	>	import java.io.ObjectStreamField;
10	>	import java.lang.reflect.ParameterizedType;
11	>	import java.lang.reflect.Type;
12	>	import java.util.Arrays;
13	>	import java.util.Collection;
14	>	import java.util.Comparator;
15	>	import java.util.ConcurrentModificationException;
16	>	import java.util.Enumeration;
17	>	import java.util.HashMap;
18	>	import java.util.Hashtable;
19	>	import java.util.Iterator;
20	>	import java.util.Map;
21	>	import java.util.NoSuchElementException;
22	>	import java.util.Set;
23	>	import java.util.Spliterator;
24	>	import java.util.concurrent.ConcurrentMap;
25	>	import java.util.concurrent.ForkJoinPool;
26	>	import java.util.concurrent.atomic.AtomicReference;
27	>	import java.util.concurrent.locks.ReentrantLock;
28	>	import java.util.concurrent.locks.StampedLock;
29	>	import java.util.function.BiConsumer;
30	>	import java.util.function.BiFunction;
31	>	import java.util.function.BinaryOperator;
32	>	import java.util.function.Consumer;
33	>	import java.util.function.DoubleBinaryOperator;
34	>	import java.util.function.Function;
35	>	import java.util.function.IntBinaryOperator;
36	>	import java.util.function.LongBinaryOperator;
37	>	import java.util.function.ToDoubleBiFunction;
38	>	import java.util.function.ToDoubleFunction;
39	>	import java.util.function.ToIntBiFunction;
40	>	import java.util.function.ToIntFunction;
41	>	import java.util.function.ToLongBiFunction;
42	>	import java.util.function.ToLongFunction;
43	>	import java.util.stream.Stream;
44
45		/**
46		* A hash table supporting full concurrency of retrievals and
47	<	* adjustable expected concurrency for updates. This class obeys the
47	>	* high expected concurrency for updates. This class obeys the
48		* same functional specification as {@link java.util.Hashtable}, and
49		* includes versions of methods corresponding to each method of
50	<	* <tt>Hashtable</tt>. However, even though all operations are
50	>	* {@code Hashtable}. However, even though all operations are
51		* thread-safe, retrieval operations do <em>not</em> entail locking,
52		* and there is <em>not</em> any support for locking the entire table
53		* in a way that prevents all access.  This class is fully
54	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
54	>	* interoperable with {@code Hashtable} in programs that rely on its
55		* thread safety but not on its synchronization details.
56		*
57	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
58	<	* block, so may overlap with update operations (including
59	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
60	<	* of the most recently <em>completed</em> update operations holding
61	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
62	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
63	<	* removal of only some entries.  Similarly, Iterators and
64	<	* Enumerations return elements reflecting the state of the hash table
65	<	* at some point at or since the creation of the iterator/enumeration.
66	<	* They do <em>not</em> throw
67	<	* {@link ConcurrentModificationException}.  However, iterators are
68	<	* designed to be used by only one thread at a time.
69	<	*
70	<	* <p> The allowed concurrency among update operations is guided by
71	<	* the optional <tt>concurrencyLevel</tt> constructor argument
72	<	* (default 16), which is used as a hint for internal sizing.  The
73	<	* table is internally partitioned to try to permit the indicated
74	<	* number of concurrent updates without contention. Because placement
75	<	* in hash tables is essentially random, the actual concurrency will
76	<	* vary.  Ideally, you should choose a value to accommodate as many
77	<	* threads as will ever concurrently modify the table. Using a
78	<	* significantly higher value than you need can waste space and time,
79	<	* and a significantly lower value can lead to thread contention. But
80	<	* overestimates and underestimates within an order of magnitude do
81	<	* not usually have much noticeable impact. A value of one is
82	<	* appropriate when it is known that only one thread will modify
83	<	* and all others will only read.
84	<	*
85	<	* <p>This class implements all of the <em>optional</em> methods
86	<	* of the {@link Map} and {@link Iterator} interfaces.
87	<	*
88	<	* <p> Like {@link java.util.Hashtable} but unlike {@link
89	<	* java.util.HashMap}, this class does NOT allow <tt>null</tt> to be
90	<	* used as a key or value.
57	>	* <p>Retrieval operations (including {@code get}) generally do not
58	>	* block, so may overlap with update operations (including {@code put}
59	>	* and {@code remove}). Retrievals reflect the results of the most
60	>	* recently <em>completed</em> update operations holding upon their
61	>	* onset. (More formally, an update operation for a given key bears a
62	>	* <em>happens-before</em> relation with any (non-null) retrieval for
63	>	* that key reporting the updated value.)  For aggregate operations
64	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
65	>	* reflect insertion or removal of only some entries.  Similarly,
66	>	* Iterators and Enumerations return elements reflecting the state of
67	>	* the hash table at some point at or since the creation of the
68	>	* iterator/enumeration.  They do <em>not</em> throw {@link
69	>	* ConcurrentModificationException}.  However, iterators are designed
70	>	* to be used by only one thread at a time.  Bear in mind that the
71	>	* results of aggregate status methods including {@code size}, {@code
72	>	* isEmpty}, and {@code containsValue} are typically useful only when
73	>	* a map is not undergoing concurrent updates in other threads.
74	>	* Otherwise the results of these methods reflect transient states
75	>	* that may be adequate for monitoring or estimation purposes, but not
76	>	* for program control.
77	>	*
78	>	* <p>The table is dynamically expanded when there are too many
79	>	* collisions (i.e., keys that have distinct hash codes but fall into
80	>	* the same slot modulo the table size), with the expected average
81	>	* effect of maintaining roughly two bins per mapping (corresponding
82	>	* to a 0.75 load factor threshold for resizing). There may be much
83	>	* variance around this average as mappings are added and removed, but
84	>	* overall, this maintains a commonly accepted time/space tradeoff for
85	>	* hash tables.  However, resizing this or any other kind of hash
86	>	* table may be a relatively slow operation. When possible, it is a
87	>	* good idea to provide a size estimate as an optional {@code
88	>	* initialCapacity} constructor argument. An additional optional
89	>	* {@code loadFactor} constructor argument provides a further means of
90	>	* customizing initial table capacity by specifying the table density
91	>	* to be used in calculating the amount of space to allocate for the
92	>	* given number of elements.  Also, for compatibility with previous
93	>	* versions of this class, constructors may optionally specify an
94	>	* expected {@code concurrencyLevel} as an additional hint for
95	>	* internal sizing.  Note that using many keys with exactly the same
96	>	* {@code hashCode()} is a sure way to slow down performance of any
97	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
98	>	* this class may use comparison order among keys to help break ties.
99	>	*
100	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
101	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
102	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
103	>	* mapped values are (perhaps transiently) not used or all take the
104	>	* same mapping value.
105	>	*
106	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
107	>	* form of histogram or multiset) by using {@link
108	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
109	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
110	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
111	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
112	>	*
113	>	* <p>This class and its views and iterators implement all of the
114	>	* <em>optional</em> methods of the {@link Map} and {@link Iterator}
115	>	* interfaces.
116	>	*
117	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
118	>	* does <em>not</em> allow {@code null} to be used as a key or value.
119	>	*
120	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
121	>	* operations that, unlike most {@link Stream} methods, are designed
122	>	* to be safely, and often sensibly, applied even with maps that are
123	>	* being concurrently updated by other threads; for example, when
124	>	* computing a snapshot summary of the values in a shared registry.
125	>	* There are three kinds of operation, each with four forms, accepting
126	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
127	>	* and/or return values. Because the elements of a ConcurrentHashMap
128	>	* are not ordered in any particular way, and may be processed in
129	>	* different orders in different parallel executions, the correctness
130	>	* of supplied functions should not depend on any ordering, or on any
131	>	* other objects or values that may transiently change while
132	>	* computation is in progress; and except for forEach actions, should
133	>	* ideally be side-effect-free. Bulk operations on {@link Map.Entry}
134	>	* objects do not support method {@code setValue}.
135	>	*
136	>	* <ul>
137	>	* <li> forEach: Perform a given action on each element.
138	>	* A variant form applies a given transformation on each element
139	>	* before performing the action.</li>
140	>	*
141	>	* <li> search: Return the first available non-null result of
142	>	* applying a given function on each element; skipping further
143	>	* search when a result is found.</li>
144	>	*
145	>	* <li> reduce: Accumulate each element.  The supplied reduction
146	>	* function cannot rely on ordering (more formally, it should be
147	>	* both associative and commutative).  There are five variants:
148	>	*
149	>	* <ul>
150	>	*
151	>	* <li> Plain reductions. (There is not a form of this method for
152	>	* (key, value) function arguments since there is no corresponding
153	>	* return type.)</li>
154	>	*
155	>	* <li> Mapped reductions that accumulate the results of a given
156	>	* function applied to each element.</li>
157	>	*
158	>	* <li> Reductions to scalar doubles, longs, and ints, using a
159	>	* given basis value.</li>
160	>	*
161	>	* </ul>
162	>	* </li>
163	>	* </ul>
164	>	*
165	>	* <p>These bulk operations accept a {@code parallelismThreshold}
166	>	* argument. Methods proceed sequentially if the current map size is
167	>	* estimated to be less than the given threshold. Using a value of
168	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
169	>	* of {@code 1} results in maximal parallelism by partitioning into
170	>	* enough subtasks to fully utilize the {@link
171	>	* ForkJoinPool#commonPool()} that is used for all parallel
172	>	* computations. Normally, you would initially choose one of these
173	>	* extreme values, and then measure performance of using in-between
174	>	* values that trade off overhead versus throughput.
175	>	*
176	>	* <p>The concurrency properties of bulk operations follow
177	>	* from those of ConcurrentHashMap: Any non-null result returned
178	>	* from {@code get(key)} and related access methods bears a
179	>	* happens-before relation with the associated insertion or
180	>	* update.  The result of any bulk operation reflects the
181	>	* composition of these per-element relations (but is not
182	>	* necessarily atomic with respect to the map as a whole unless it
183	>	* is somehow known to be quiescent).  Conversely, because keys
184	>	* and values in the map are never null, null serves as a reliable
185	>	* atomic indicator of the current lack of any result.  To
186	>	* maintain this property, null serves as an implicit basis for
187	>	* all non-scalar reduction operations. For the double, long, and
188	>	* int versions, the basis should be one that, when combined with
189	>	* any other value, returns that other value (more formally, it
190	>	* should be the identity element for the reduction). Most common
191	>	* reductions have these properties; for example, computing a sum
192	>	* with basis 0 or a minimum with basis MAX_VALUE.
193	>	*
194	>	* <p>Search and transformation functions provided as arguments
195	>	* should similarly return null to indicate the lack of any result
196	>	* (in which case it is not used). In the case of mapped
197	>	* reductions, this also enables transformations to serve as
198	>	* filters, returning null (or, in the case of primitive
199	>	* specializations, the identity basis) if the element should not
200	>	* be combined. You can create compound transformations and
201	>	* filterings by composing them yourself under this "null means
202	>	* there is nothing there now" rule before using them in search or
203	>	* reduce operations.
204	>	*
205	>	* <p>Methods accepting and/or returning Entry arguments maintain
206	>	* key-value associations. They may be useful for example when
207	>	* finding the key for the greatest value. Note that "plain" Entry
208	>	* arguments can be supplied using {@code new
209	>	* AbstractMap.SimpleEntry(k,v)}.
210	>	*
211	>	* <p>Bulk operations may complete abruptly, throwing an
212	>	* exception encountered in the application of a supplied
213	>	* function. Bear in mind when handling such exceptions that other
214	>	* concurrently executing functions could also have thrown
215	>	* exceptions, or would have done so if the first exception had
216	>	* not occurred.
217	>	*
218	>	* <p>Speedups for parallel compared to sequential forms are common
219	>	* but not guaranteed.  Parallel operations involving brief functions
220	>	* on small maps may execute more slowly than sequential forms if the
221	>	* underlying work to parallelize the computation is more expensive
222	>	* than the computation itself.  Similarly, parallelization may not
223	>	* lead to much actual parallelism if all processors are busy
224	>	* performing unrelated tasks.
225	>	*
226	>	* <p>All arguments to all task methods must be non-null.
227	>	*
228	>	* <p>This class is a member of the
229	>	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
230	>	* Java Collections Framework</a>.
231		*
232		* @since 1.5
233		* @author Doug Lea
234		* @param <K> the type of keys maintained by this map
235	<	* @param <V> the type of mapped values
235	>	* @param <V> the type of mapped values
236		*/
237	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
238	<	implements ConcurrentMap<K, V>, Cloneable, Serializable {
237	>	@SuppressWarnings({"unchecked", "rawtypes", "serial"})
238	>	public class ConcurrentHashMap<K,V> implements ConcurrentMap<K,V>, Serializable {
239		private static final long serialVersionUID = 7249069246763182397L;
240
241		/*
242	<	* The basic strategy is to subdivide the table among Segments,
243	<	* each of which itself is a concurrently readable hash table.
242	>	* Overview:
243	>	*
244	>	* The primary design goal of this hash table is to maintain
245	>	* concurrent readability (typically method get(), but also
246	>	* iterators and related methods) while minimizing update
247	>	* contention. Secondary goals are to keep space consumption about
248	>	* the same or better than java.util.HashMap, and to support high
249	>	* initial insertion rates on an empty table by many threads.
250	>	*
251	>	* Each key-value mapping is held in a Node.  Because Node key
252	>	* fields can contain special values, they are defined using plain
253	>	* Object types (not type "K"). This leads to a lot of explicit
254	>	* casting (and the use of class-wide warning suppressions).  It
255	>	* also allows some of the public methods to be factored into a
256	>	* smaller number of internal methods (although sadly not so for
257	>	* the five variants of put-related operations). The
258	>	* validation-based approach explained below leads to a lot of
259	>	* code sprawl because retry-control precludes factoring into
260	>	* smaller methods.
261	>	*
262	>	* The table is lazily initialized to a power-of-two size upon the
263	>	* first insertion.  Each bin in the table normally contains a
264	>	* list of Nodes (most often, the list has only zero or one Node).
265	>	* Table accesses require volatile/atomic reads, writes, and
266	>	* CASes.  Because there is no other way to arrange this without
267	>	* adding further indirections, we use intrinsics
268	>	* (sun.misc.Unsafe) operations.
269	>	*
270	>	* We use the top (sign) bit of Node hash fields for control
271	>	* purposes -- it is available anyway because of addressing
272	>	* constraints.  Nodes with negative hash fields are forwarding
273	>	* nodes to either TreeBins or resized tables.  The lower 31 bits
274	>	* of each normal Node's hash field contain a transformation of
275	>	* the key's hash code.
276	>	*
277	>	* Insertion (via put or its variants) of the first node in an
278	>	* empty bin is performed by just CASing it to the bin.  This is
279	>	* by far the most common case for put operations under most
280	>	* key/hash distributions.  Other update operations (insert,
281	>	* delete, and replace) require locks.  We do not want to waste
282	>	* the space required to associate a distinct lock object with
283	>	* each bin, so instead use the first node of a bin list itself as
284	>	* a lock. Locking support for these locks relies on builtin
285	>	* "synchronized" monitors.
286	>	*
287	>	* Using the first node of a list as a lock does not by itself
288	>	* suffice though: When a node is locked, any update must first
289	>	* validate that it is still the first node after locking it, and
290	>	* retry if not. Because new nodes are always appended to lists,
291	>	* once a node is first in a bin, it remains first until deleted
292	>	* or the bin becomes invalidated (upon resizing).
293	>	*
294	>	* The main disadvantage of per-bin locks is that other update
295	>	* operations on other nodes in a bin list protected by the same
296	>	* lock can stall, for example when user equals() or mapping
297	>	* functions take a long time.  However, statistically, under
298	>	* random hash codes, this is not a common problem.  Ideally, the
299	>	* frequency of nodes in bins follows a Poisson distribution
300	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
301	>	* parameter of about 0.5 on average, given the resizing threshold
302	>	* of 0.75, although with a large variance because of resizing
303	>	* granularity. Ignoring variance, the expected occurrences of
304	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
305	>	* first values are:
306	>	*
307	>	* 0:    0.60653066
308	>	* 1:    0.30326533
309	>	* 2:    0.07581633
310	>	* 3:    0.01263606
311	>	* 4:    0.00157952
312	>	* 5:    0.00015795
313	>	* 6:    0.00001316
314	>	* 7:    0.00000094
315	>	* 8:    0.00000006
316	>	* more: less than 1 in ten million
317	>	*
318	>	* Lock contention probability for two threads accessing distinct
319	>	* elements is roughly 1 / (8 * #elements) under random hashes.
320	>	*
321	>	* Actual hash code distributions encountered in practice
322	>	* sometimes deviate significantly from uniform randomness.  This
323	>	* includes the case when N > (1<<30), so some keys MUST collide.
324	>	* Similarly for dumb or hostile usages in which multiple keys are
325	>	* designed to have identical hash codes. Also, although we guard
326	>	* against the worst effects of this (see method spread), sets of
327	>	* hashes may differ only in bits that do not impact their bin
328	>	* index for a given power-of-two mask.  So we use a secondary
329	>	* strategy that applies when the number of nodes in a bin exceeds
330	>	* a threshold, and at least one of the keys implements
331	>	* Comparable.  These TreeBins use a balanced tree to hold nodes
332	>	* (a specialized form of red-black trees), bounding search time
333	>	* to O(log N).  Each search step in a TreeBin is at least twice as
334	>	* slow as in a regular list, but given that N cannot exceed
335	>	* (1<<64) (before running out of addresses) this bounds search
336	>	* steps, lock hold times, etc, to reasonable constants (roughly
337	>	* 100 nodes inspected per operation worst case) so long as keys
338	>	* are Comparable (which is very common -- String, Long, etc).
339	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
340	>	* traversal pointers as regular nodes, so can be traversed in
341	>	* iterators in the same way.
342	>	*
343	>	* The table is resized when occupancy exceeds a percentage
344	>	* threshold (nominally, 0.75, but see below).  Any thread
345	>	* noticing an overfull bin may assist in resizing after the
346	>	* initiating thread allocates and sets up the replacement
347	>	* array. However, rather than stalling, these other threads may
348	>	* proceed with insertions etc.  The use of TreeBins shields us
349	>	* from the worst case effects of overfilling while resizes are in
350	>	* progress.  Resizing proceeds by transferring bins, one by one,
351	>	* from the table to the next table. To enable concurrency, the
352	>	* next table must be (incrementally) prefilled with place-holders
353	>	* serving as reverse forwarders to the old table.  Because we are
354	>	* using power-of-two expansion, the elements from each bin must
355	>	* either stay at same index, or move with a power of two
356	>	* offset. We eliminate unnecessary node creation by catching
357	>	* cases where old nodes can be reused because their next fields
358	>	* won't change.  On average, only about one-sixth of them need
359	>	* cloning when a table doubles. The nodes they replace will be
360	>	* garbage collectable as soon as they are no longer referenced by
361	>	* any reader thread that may be in the midst of concurrently
362	>	* traversing table.  Upon transfer, the old table bin contains
363	>	* only a special forwarding node (with hash field "MOVED") that
364	>	* contains the next table as its key. On encountering a
365	>	* forwarding node, access and update operations restart, using
366	>	* the new table.
367	>	*
368	>	* Each bin transfer requires its bin lock, which can stall
369	>	* waiting for locks while resizing. However, because other
370	>	* threads can join in and help resize rather than contend for
371	>	* locks, average aggregate waits become shorter as resizing
372	>	* progresses.  The transfer operation must also ensure that all
373	>	* accessible bins in both the old and new table are usable by any
374	>	* traversal.  This is arranged by proceeding from the last bin
375	>	* (table.length - 1) up towards the first.  Upon seeing a
376	>	* forwarding node, traversals (see class Traverser) arrange to
377	>	* move to the new table without revisiting nodes.  However, to
378	>	* ensure that no intervening nodes are skipped, bin splitting can
379	>	* only begin after the associated reverse-forwarders are in
380	>	* place.
381	>	*
382	>	* The traversal scheme also applies to partial traversals of
383	>	* ranges of bins (via an alternate Traverser constructor)
384	>	* to support partitioned aggregate operations.  Also, read-only
385	>	* operations give up if ever forwarded to a null table, which
386	>	* provides support for shutdown-style clearing, which is also not
387	>	* currently implemented.
388	>	*
389	>	* Lazy table initialization minimizes footprint until first use,
390	>	* and also avoids resizings when the first operation is from a
391	>	* putAll, constructor with map argument, or deserialization.
392	>	* These cases attempt to override the initial capacity settings,
393	>	* but harmlessly fail to take effect in cases of races.
394	>	*
395	>	* The element count is maintained using a specialization of
396	>	* LongAdder. We need to incorporate a specialization rather than
397	>	* just use a LongAdder in order to access implicit
398	>	* contention-sensing that leads to creation of multiple
399	>	* Cells.  The counter mechanics avoid contention on
400	>	* updates but can encounter cache thrashing if read too
401	>	* frequently during concurrent access. To avoid reading so often,
402	>	* resizing under contention is attempted only upon adding to a
403	>	* bin already holding two or more nodes. Under uniform hash
404	>	* distributions, the probability of this occurring at threshold
405	>	* is around 13%, meaning that only about 1 in 8 puts check
406	>	* threshold (and after resizing, many fewer do so). The bulk
407	>	* putAll operation further reduces contention by only committing
408	>	* count updates upon these size checks.
409	>	*
410	>	* Maintaining API and serialization compatibility with previous
411	>	* versions of this class introduces several oddities. Mainly: We
412	>	* leave untouched but unused constructor arguments refering to
413	>	* concurrencyLevel. We accept a loadFactor constructor argument,
414	>	* but apply it only to initial table capacity (which is the only
415	>	* time that we can guarantee to honor it.) We also declare an
416	>	* unused "Segment" class that is instantiated in minimal form
417	>	* only when serializing.
418		*/
419
420		/* ---------------- Constants -------------- */
421
422		/**
423	<	* The default initial number of table slots for this table.
424	<	* Used when not otherwise specified in constructor.
423	>	* The largest possible table capacity.  This value must be
424	>	* exactly 1<<30 to stay within Java array allocation and indexing
425	>	* bounds for power of two table sizes, and is further required
426	>	* because the top two bits of 32bit hash fields are used for
427	>	* control purposes.
428		*/
429	<	private static int DEFAULT_INITIAL_CAPACITY = 16;
429	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
430
431		/**
432	<	* The maximum capacity, used if a higher value is implicitly
433	<	* specified by either of the constructors with arguments.  MUST
87	<	* be a power of two <= 1<<30 to ensure that entries are indexible
88	<	* using ints.
432	>	* The default initial table capacity.  Must be a power of 2
433	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
434		*/
435	<	static final int MAXIMUM_CAPACITY = 1 << 30;
435	>	private static final int DEFAULT_CAPACITY = 16;
436
437		/**
438	<	* The default load factor for this table.  Used when not
439	<	* otherwise specified in constructor.
438	>	* The largest possible (non-power of two) array size.
439	>	* Needed by toArray and related methods.
440		*/
441	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
441	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
442
443		/**
444	<	* The default number of concurrency control segments.
445	<	**/
446	<	private static final int DEFAULT_SEGMENTS = 16;
444	>	* The default concurrency level for this table. Unused but
445	>	* defined for compatibility with previous versions of this class.
446	>	*/
447	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
448
449		/**
450	<	* The maximum number of segments to allow; used to bound ctor arguments.
450	>	* The load factor for this table. Overrides of this value in
451	>	* constructors affect only the initial table capacity.  The
452	>	* actual floating point value isn't normally used -- it is
453	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
454	>	* the associated resizing threshold.
455		*/
456	<	private static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
456	>	private static final float LOAD_FACTOR = 0.75f;
457	>
458	>	/**
459	>	* The bin count threshold for using a tree rather than list for a
460	>	* bin.  The value reflects the approximate break-even point for
461	>	* using tree-based operations.
462	>	*/
463	>	private static final int TREE_THRESHOLD = 8;
464	>
465	>	/**
466	>	* Minimum number of rebinnings per transfer step. Ranges are
467	>	* subdivided to allow multiple resizer threads.  This value
468	>	* serves as a lower bound to avoid resizers encountering
469	>	* excessive memory contention.  The value should be at least
470	>	* DEFAULT_CAPACITY.
471	>	*/
472	>	private static final int MIN_TRANSFER_STRIDE = 16;
473	>
474	>	/*
475	>	* Encodings for Node hash fields. See above for explanation.
476	>	*/
477	>	static final int MOVED     = 0x80000000; // hash field for forwarding nodes
478	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
479	>
480	>	/** Number of CPUS, to place bounds on some sizings */
481	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
482	>
483	>	/** For serialization compatibility. */
484	>	private static final ObjectStreamField[] serialPersistentFields = {
485	>	new ObjectStreamField("segments", Segment[].class),
486	>	new ObjectStreamField("segmentMask", Integer.TYPE),
487	>	new ObjectStreamField("segmentShift", Integer.TYPE)
488	>	};
489	>
490	>	/**
491	>	* A padded cell for distributing counts.  Adapted from LongAdder
492	>	* and Striped64.  See their internal docs for explanation.
493	>	*/
494	>	@sun.misc.Contended static final class Cell {
495	>	volatile long value;
496	>	Cell(long x) { value = x; }
497	>	}
498
499		/* ---------------- Fields -------------- */
500
501		/**
502	<	* Mask value for indexing into segments. The upper bits of a
503	<	* key's hash code are used to choose the segment.
504	<	**/
505	<	private final int segmentMask;
502	>	* The array of bins. Lazily initialized upon first insertion.
503	>	* Size is always a power of two. Accessed directly by iterators.
504	>	*/
505	>	transient volatile Node<K,V>[] table;
506	>
507	>	/**
508	>	* The next table to use; non-null only while resizing.
509	>	*/
510	>	private transient volatile Node<K,V>[] nextTable;
511
512		/**
513	<	* Shift value for indexing within segments.
514	<	**/
515	<	private final int segmentShift;
513	>	* Base counter value, used mainly when there is no contention,
514	>	* but also as a fallback during table initialization
515	>	* races. Updated via CAS.
516	>	*/
517	>	private transient volatile long baseCount;
518
519		/**
520	<	* The segments, each of which is a specialized hash table
520	>	* Table initialization and resizing control.  When negative, the
521	>	* table is being initialized or resized: -1 for initialization,
522	>	* else -(1 + the number of active resizing threads).  Otherwise,
523	>	* when table is null, holds the initial table size to use upon
524	>	* creation, or 0 for default. After initialization, holds the
525	>	* next element count value upon which to resize the table.
526		*/
527	<	private final Segment[] segments;
527	>	private transient volatile int sizeCtl;
528
529	<	private transient Set<K> keySet;
530	<	private transient Set<Map.Entry<K,V>> entrySet;
531	<	private transient Collection<V> values;
529	>	/**
530	>	* The next table index (plus one) to split while resizing.
531	>	*/
532	>	private transient volatile int transferIndex;
533
534	<	/* ---------------- Small Utilities -------------- */
534	>	/**
535	>	* The least available table index to split while resizing.
536	>	*/
537	>	private transient volatile int transferOrigin;
538
539		/**
540	<	* Return a hash code for non-null Object x.
134	<	* Uses the same hash code spreader as most other j.u hash tables.
135	<	* @param x the object serving as a key
136	<	* @return the hash code
540	>	* Spinlock (locked via CAS) used when resizing and/or creating Cells.
541		*/
542	<	private static int hash(Object x) {
139	<	int h = x.hashCode();
140	<	h += ~(h << 9);
141	<	h ^=  (h >>> 14);
142	<	h +=  (h << 4);
143	<	h ^=  (h >>> 10);
144	<	return h;
145	<	}
542	>	private transient volatile int cellsBusy;
543
544		/**
545	<	* Return the segment that should be used for key with given hash
545	>	* Table of counter cells. When non-null, size is a power of 2.
546		*/
547	<	private Segment<K,V> segmentFor(int hash) {
548	<	return (Segment<K,V>) segments[(hash >>> segmentShift) & segmentMask];
547	>	private transient volatile Cell[] counterCells;
548	>
549	>	// views
550	>	private transient KeySetView<K,V> keySet;
551	>	private transient ValuesView<K,V> values;
552	>	private transient EntrySetView<K,V> entrySet;
553	>
554	>	/* ---------------- Table element access -------------- */
555	>
556	>	/*
557	>	* Volatile access methods are used for table elements as well as
558	>	* elements of in-progress next table while resizing.  Uses are
559	>	* null checked by callers, and implicitly bounds-checked, relying
560	>	* on the invariants that tab arrays have non-zero size, and all
561	>	* indices are masked with (tab.length - 1) which is never
562	>	* negative and always less than length. Note that, to be correct
563	>	* wrt arbitrary concurrency errors by users, bounds checks must
564	>	* operate on local variables, which accounts for some odd-looking
565	>	* inline assignments below.
566	>	*/
567	>
568	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
569	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
570		}
571
572	<	/* ---------------- Inner Classes -------------- */
572	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
573	>	Node<K,V> c, Node<K,V> v) {
574	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
575	>	}
576	>
577	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
578	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
579	>	}
580	>
581	>	/* ---------------- Nodes -------------- */
582
583		/**
584	<	* Segments are specialized versions of hash tables.  This
585	<	* subclasses from ReentrantLock opportunistically, just to
586	<	* simplify some locking and avoid separate construction.
587	<	**/
588	<	private static final class Segment<K,V> extends ReentrantLock implements Serializable {
589	<	/*
590	<	* Segments maintain a table of entry lists that are ALWAYS
591	<	* kept in a consistent state, so can be read without locking.
592	<	* Next fields of nodes are immutable (final).  All list
593	<	* additions are performed at the front of each bin. This
594	<	* makes it easy to check changes, and also fast to traverse.
595	<	* When nodes would otherwise be changed, new nodes are
596	<	* created to replace them. This works well for hash tables
597	<	* since the bin lists tend to be short. (The average length
598	<	* is less than two for the default load factor threshold.)
599	<	*
600	<	* Read operations can thus proceed without locking, but rely
601	<	* on a memory barrier to ensure that completed write
602	<	* operations performed by other threads are
603	<	* noticed. Conveniently, the "count" field, tracking the
604	<	* number of elements, can also serve as the volatile variable
605	<	* providing proper read/write barriers. This is convenient
606	<	* because this field needs to be read in many read operations
607	<	* anyway.
608	<	*
609	<	* Implementors note. The basic rules for all this are:
610	<	*
611	<	*   - All unsynchronized read operations must first read the
612	<	*     "count" field, and should not look at table entries if
613	<	*     it is 0.
614	<	*
615	<	*   - All synchronized write operations should write to
616	<	*     the "count" field after updating. The operations must not
617	<	*     take any action that could even momentarily cause
618	<	*     a concurrent read operation to see inconsistent
619	<	*     data. This is made easier by the nature of the read
620	<	*     operations in Map. For example, no operation
621	<	*     can reveal that the table has grown but the threshold
622	<	*     has not yet been updated, so there are no atomicity
623	<	*     requirements for this with respect to reads.
624	<	*
625	<	* As a guide, all critical volatile reads and writes are marked
626	<	* in code comments.
584	>	* Key-value entry.  This class is never exported out as a
585	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
586	>	* MapEntry below), but can be used for read-only traversals used
587	>	* in bulk tasks.  Nodes with a hash field of MOVED are special,
588	>	* and do not contain user keys or values (and are never
589	>	* exported).  Otherwise, keys and vals are never null.
590	>	*/
591	>	static class Node<K,V> implements Map.Entry<K,V> {
592	>	final int hash;
593	>	final Object key;
594	>	volatile V val;
595	>	Node<K,V> next;
596	>
597	>	Node(int hash, Object key, V val, Node<K,V> next) {
598	>	this.hash = hash;
599	>	this.key = key;
600	>	this.val = val;
601	>	this.next = next;
602	>	}
603	>
604	>	public final K getKey()       { return (K)key; }
605	>	public final V getValue()     { return val; }
606	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
607	>	public final String toString(){ return key + "=" + val; }
608	>	public final V setValue(V value) {
609	>	throw new UnsupportedOperationException();
610	>	}
611	>
612	>	public final boolean equals(Object o) {
613	>	Object k, v, u; Map.Entry<?,?> e;
614	>	return ((o instanceof Map.Entry) &&
615	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
616	>	(v = e.getValue()) != null &&
617	>	(k == key || k.equals(key)) &&
618	>	(v == (u = val) || v.equals(u)));
619	>	}
620	>	}
621	>
622	>	/**
623	>	* Exported Entry for EntryIterator
624	>	*/
625	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
626	>	final K key; // non-null
627	>	V val;       // non-null
628	>	final ConcurrentHashMap<K,V> map;
629	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
630	>	this.key = key;
631	>	this.val = val;
632	>	this.map = map;
633	>	}
634	>	public K getKey()        { return key; }
635	>	public V getValue()      { return val; }
636	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
637	>	public String toString() { return key + "=" + val; }
638	>
639	>	public boolean equals(Object o) {
640	>	Object k, v; Map.Entry<?,?> e;
641	>	return ((o instanceof Map.Entry) &&
642	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
643	>	(v = e.getValue()) != null &&
644	>	(k == key || k.equals(key)) &&
645	>	(v == val || v.equals(val)));
646	>	}
647	>
648	>	/**
649	>	* Sets our entry's value and writes through to the map. The
650	>	* value to return is somewhat arbitrary here. Since we do not
651	>	* necessarily track asynchronous changes, the most recent
652	>	* "previous" value could be different from what we return (or
653	>	* could even have been removed, in which case the put will
654	>	* re-establish). We do not and cannot guarantee more.
655		*/
656	+	public V setValue(V value) {
657	+	if (value == null) throw new NullPointerException();
658	+	V v = val;
659	+	val = value;
660	+	map.put(key, value);
661	+	return v;
662	+	}
663	+	}
664	+
665	+
666	+	/* ---------------- TreeBins -------------- */
667	+
668	+	/**
669	+	* Nodes for use in TreeBins
670	+	*/
671	+	static final class TreeNode<K,V> extends Node<K,V> {
672	+	TreeNode<K,V> parent;  // red-black tree links
673	+	TreeNode<K,V> left;
674	+	TreeNode<K,V> right;
675	+	TreeNode<K,V> prev;    // needed to unlink next upon deletion
676	+	boolean red;
677	+
678	+	TreeNode(int hash, Object key, V val, Node<K,V> next,
679	+	TreeNode<K,V> parent) {
680	+	super(hash, key, val, next);
681	+	this.parent = parent;
682	+	}
683	+	}
684	+
685	+	/**
686	+	* Returns a Class for the given type of the form "class C
687	+	* implements Comparable<C>", if one exists, else null.  See below
688	+	* for explanation.
689	+	*/
690	+	static Class<?> comparableClassFor(Class<?> c) {
691	+	Class<?> s, cmpc; Type[] ts, as; Type t; ParameterizedType p;
692	+	if (c == String.class) // bypass checks
693	+	return c;
694	+	if (c != null && (cmpc = Comparable.class).isAssignableFrom(c)) {
695	+	while (cmpc.isAssignableFrom(s = c.getSuperclass()))
696	+	c = s; // find topmost comparable class
697	+	if ((ts = c.getGenericInterfaces()) != null) {
698	+	for (int i = 0; i < ts.length; ++i) {
699	+	if (((t = ts[i]) instanceof ParameterizedType) &&
700	+	((p = (ParameterizedType)t).getRawType() == cmpc) &&
701	+	(as = p.getActualTypeArguments()) != null &&
702	+	as.length == 1 && as[0] == c) // type arg is c
703	+	return c;
704	+	}
705	+	}
706	+	}
707	+	return null;
708	+	}
709
710	+	/**
711	+	* A specialized form of red-black tree for use in bins
712	+	* whose size exceeds a threshold.
713	+	*
714	+	* TreeBins use a special form of comparison for search and
715	+	* related operations (which is the main reason we cannot use
716	+	* existing collections such as TreeMaps). TreeBins contain
717	+	* Comparable elements, but may contain others, as well as
718	+	* elements that are Comparable but not necessarily Comparable
719	+	* for the same T, so we cannot invoke compareTo among them. To
720	+	* handle this, the tree is ordered primarily by hash value, then
721	+	* by Comparable.compareTo order if applicable.  On lookup at a
722	+	* node, if elements are not comparable or compare as 0 then both
723	+	* left and right children may need to be searched in the case of
724	+	* tied hash values. (This corresponds to the full list search
725	+	* that would be necessary if all elements were non-Comparable and
726	+	* had tied hashes.)  The red-black balancing code is updated from
727	+	* pre-jdk-collections
728	+	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
729	+	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
730	+	* Algorithms" (CLR).
731	+	*
732	+	* TreeBins also maintain a separate locking discipline than
733	+	* regular bins. Because they are forwarded via special MOVED
734	+	* nodes at bin heads (which can never change once established),
735	+	* we cannot use those nodes as locks. Instead, TreeBin extends
736	+	* StampedLock to support a form of read-write lock. For update
737	+	* operations and table validation, the exclusive form of lock
738	+	* behaves in the same way as bin-head locks. However, lookups use
739	+	* shared read-lock mechanics to allow multiple readers in the
740	+	* absence of writers.  Additionally, these lookups do not ever
741	+	* block: While the lock is not available, they proceed along the
742	+	* slow traversal path (via next-pointers) until the lock becomes
743	+	* available or the list is exhausted, whichever comes
744	+	* first. These cases are not fast, but maximize aggregate
745	+	* expected throughput.
746	+	*/
747	+	static final class TreeBin<K,V> extends StampedLock {
748		private static final long serialVersionUID = 2249069246763182397L;
749	+	transient TreeNode<K,V> root;  // root of tree
750	+	transient TreeNode<K,V> first; // head of next-pointer list
751
752	<	/**
753	<	* The number of elements in this segment's region.
754	<	**/
755	<	transient volatile int count;
752	>	/** From CLR */
753	>	private void rotateLeft(TreeNode<K,V> p) {
754	>	if (p != null) {
755	>	TreeNode<K,V> r = p.right, pp, rl;
756	>	if ((rl = p.right = r.left) != null)
757	>	rl.parent = p;
758	>	if ((pp = r.parent = p.parent) == null)
759	>	root = r;
760	>	else if (pp.left == p)
761	>	pp.left = r;
762	>	else
763	>	pp.right = r;
764	>	r.left = p;
765	>	p.parent = r;
766	>	}
767	>	}
768	>
769	>	/** From CLR */
770	>	private void rotateRight(TreeNode<K,V> p) {
771	>	if (p != null) {
772	>	TreeNode<K,V> l = p.left, pp, lr;
773	>	if ((lr = p.left = l.right) != null)
774	>	lr.parent = p;
775	>	if ((pp = l.parent = p.parent) == null)
776	>	root = l;
777	>	else if (pp.right == p)
778	>	pp.right = l;
779	>	else
780	>	pp.left = l;
781	>	l.right = p;
782	>	p.parent = l;
783	>	}
784	>	}
785
786		/**
787	<	* Number of updates; used for checking lack of modifications
788	<	* in bulk-read methods.
787	>	* Returns the TreeNode (or null if not found) for the given key
788	>	* starting at given root.
789		*/
790	<	transient int modCount;
790	>	final TreeNode<K,V> getTreeNode(int h, Object k, TreeNode<K,V> p,
791	>	Class<?> cc) {
792	>	while (p != null) {
793	>	int dir, ph; Object pk; Class<?> pc;
794	>	if ((ph = p.hash) != h)
795	>	dir = (h < ph) ? -1 : 1;
796	>	else if ((pk = p.key) == k || k.equals(pk))
797	>	return p;
798	>	else if (cc == null || pk == null ||
799	>	((pc = pk.getClass()) != cc &&
800	>	comparableClassFor(pc) != cc) ||
801	>	(dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
802	>	TreeNode<K,V> r, pr; // check both sides
803	>	if ((pr = p.right) != null &&
804	>	(r = getTreeNode(h, k, pr, cc)) != null)
805	>	return r;
806	>	else // continue left
807	>	dir = -1;
808	>	}
809	>	p = (dir > 0) ? p.right : p.left;
810	>	}
811	>	return null;
812	>	}
813
814		/**
815	<	* The table is rehashed when its size exceeds this threshold.
816	<	* (The value of this field is always (int)(capacity *
817	<	* loadFactor).)
815	>	* Wrapper for getTreeNode used by CHM.get. Tries to obtain
816	>	* read-lock to call getTreeNode, but during failure to get
817	>	* lock, searches along next links.
818		*/
819	<	private transient int threshold;
819	>	final V getValue(int h, Object k) {
820	>	Class<?> cc = comparableClassFor(k.getClass());
821	>	Node<K,V> r = null;
822	>	for (Node<K,V> e = first; e != null; e = e.next) {
823	>	long s;
824	>	if ((s = tryReadLock()) != 0L) {
825	>	try {
826	>	r = getTreeNode(h, k, root, cc);
827	>	} finally {
828	>	unlockRead(s);
829	>	}
830	>	break;
831	>	}
832	>	else if (e.hash == h && k.equals(e.key)) {
833	>	r = e;
834	>	break;
835	>	}
836	>	}
837	>	return r == null ? null : r.val;
838	>	}
839
840		/**
841	<	* The per-segment table
841	>	* Finds or adds a node.
842	>	* @return null if added
843		*/
844	<	transient HashEntry[] table;
844	>	final TreeNode<K,V> putTreeNode(int h, Object k, V v) {
845	>	Class<?> cc = comparableClassFor(k.getClass());
846	>	TreeNode<K,V> pp = root, p = null;
847	>	int dir = 0;
848	>	while (pp != null) { // find existing node or leaf to insert at
849	>	int ph; Object pk; Class<?> pc;
850	>	p = pp;
851	>	if ((ph = p.hash) != h)
852	>	dir = (h < ph) ? -1 : 1;
853	>	else if ((pk = p.key) == k || k.equals(pk))
854	>	return p;
855	>	else if (cc == null || pk == null ||
856	>	((pc = pk.getClass()) != cc &&
857	>	comparableClassFor(pc) != cc) ||
858	>	(dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
859	>	TreeNode<K,V> r, pr;
860	>	if ((pr = p.right) != null &&
861	>	(r = getTreeNode(h, k, pr, cc)) != null)
862	>	return r;
863	>	else // continue left
864	>	dir = -1;
865	>	}
866	>	pp = (dir > 0) ? p.right : p.left;
867	>	}
868	>
869	>	TreeNode<K,V> f = first;
870	>	TreeNode<K,V> x = first = new TreeNode<K,V>(h, k, v, f, p);
871	>	if (p == null)
872	>	root = x;
873	>	else { // attach and rebalance; adapted from CLR
874	>	if (f != null)
875	>	f.prev = x;
876	>	if (dir <= 0)
877	>	p.left = x;
878	>	else
879	>	p.right = x;
880	>	x.red = true;
881	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
882	>	if ((xp = x.parent) == null) {
883	>	(root = x).red = false;
884	>	break;
885	>	}
886	>	else if (!xp.red || (xpp = xp.parent) == null) {
887	>	TreeNode<K,V> r = root;
888	>	if (r != null && r.red)
889	>	r.red = false;
890	>	break;
891	>	}
892	>	else if ((xppl = xpp.left) == xp) {
893	>	if ((xppr = xpp.right) != null && xppr.red) {
894	>	xppr.red = false;
895	>	xp.red = false;
896	>	xpp.red = true;
897	>	x = xpp;
898	>	}
899	>	else {
900	>	if (x == xp.right) {
901	>	rotateLeft(x = xp);
902	>	xpp = (xp = x.parent) == null ? null : xp.parent;
903	>	}
904	>	if (xp != null) {
905	>	xp.red = false;
906	>	if (xpp != null) {
907	>	xpp.red = true;
908	>	rotateRight(xpp);
909	>	}
910	>	}
911	>	}
912	>	}
913	>	else {
914	>	if (xppl != null && xppl.red) {
915	>	xppl.red = false;
916	>	xp.red = false;
917	>	xpp.red = true;
918	>	x = xpp;
919	>	}
920	>	else {
921	>	if (x == xp.left) {
922	>	rotateRight(x = xp);
923	>	xpp = (xp = x.parent) == null ? null : xp.parent;
924	>	}
925	>	if (xp != null) {
926	>	xp.red = false;
927	>	if (xpp != null) {
928	>	xpp.red = true;
929	>	rotateLeft(xpp);
930	>	}
931	>	}
932	>	}
933	>	}
934	>	}
935	>	}
936	>	assert checkInvariants();
937	>	return null;
938	>	}
939
940		/**
941	<	* The load factor for the hash table.  Even though this value
942	<	* is same for all segments, it is replicated to avoid needing
943	<	* links to outer object.
944	<	* @serial
941	>	* Removes the given node, that must be present before this
942	>	* call.  This is messier than typical red-black deletion code
943	>	* because we cannot swap the contents of an interior node
944	>	* with a leaf successor that is pinned by "next" pointers
945	>	* that are accessible independently of lock. So instead we
946	>	* swap the tree linkages.
947		*/
948	<	private final float loadFactor;
948	>	final void deleteTreeNode(TreeNode<K,V> p) {
949	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
950	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
951	>	if (pred == null)
952	>	first = next;
953	>	else
954	>	pred.next = next;
955	>	if (next != null)
956	>	next.prev = pred;
957	>	else if (pred == null) {
958	>	root = null;
959	>	return;
960	>	}
961	>	TreeNode<K,V> replacement;
962	>	TreeNode<K,V> pl = p.left;
963	>	TreeNode<K,V> pr = p.right;
964	>	if (pl != null && pr != null) {
965	>	TreeNode<K,V> s = pr, sl;
966	>	while ((sl = s.left) != null) // find successor
967	>	s = sl;
968	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
969	>	TreeNode<K,V> sr = s.right;
970	>	TreeNode<K,V> pp = p.parent;
971	>	if (s == pr) { // p was s's direct parent
972	>	p.parent = s;
973	>	s.right = p;
974	>	}
975	>	else {
976	>	TreeNode<K,V> sp = s.parent;
977	>	if ((p.parent = sp) != null) {
978	>	if (s == sp.left)
979	>	sp.left = p;
980	>	else
981	>	sp.right = p;
982	>	}
983	>	if ((s.right = pr) != null)
984	>	pr.parent = s;
985	>	}
986	>	p.left = null;
987	>	if ((p.right = sr) != null)
988	>	sr.parent = p;
989	>	if ((s.left = pl) != null)
990	>	pl.parent = s;
991	>	if ((s.parent = pp) == null)
992	>	root = s;
993	>	else if (p == pp.left)
994	>	pp.left = s;
995	>	else
996	>	pp.right = s;
997	>	if (sr != null)
998	>	replacement = sr;
999	>	else
1000	>	replacement = p;
1001	>	}
1002	>	else if (pl != null)
1003	>	replacement = pl;
1004	>	else if (pr != null)
1005	>	replacement = pr;
1006	>	else
1007	>	replacement = p;
1008	>	if (replacement != p) {
1009	>	TreeNode<K,V> pp = replacement.parent = p.parent;
1010	>	if (pp == null)
1011	>	root = replacement;
1012	>	else if (p == pp.left)
1013	>	pp.left = replacement;
1014	>	else
1015	>	pp.right = replacement;
1016	>	p.left = p.right = p.parent = null;
1017	>	}
1018	>	if (!p.red) { // rebalance, from CLR
1019	>	for (TreeNode<K,V> x = replacement; x != null; ) {
1020	>	TreeNode<K,V> xp, xpl, xpr;
1021	>	if (x.red || (xp = x.parent) == null) {
1022	>	x.red = false;
1023	>	break;
1024	>	}
1025	>	else if ((xpl = xp.left) == x) {
1026	>	if ((xpr = xp.right) != null && xpr.red) {
1027	>	xpr.red = false;
1028	>	xp.red = true;
1029	>	rotateLeft(xp);
1030	>	xpr = (xp = x.parent) == null ? null : xp.right;
1031	>	}
1032	>	if (xpr == null)
1033	>	x = xp;
1034	>	else {
1035	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
1036	>	if ((sr == null || !sr.red) &&
1037	>	(sl == null || !sl.red)) {
1038	>	xpr.red = true;
1039	>	x = xp;
1040	>	}
1041	>	else {
1042	>	if (sr == null || !sr.red) {
1043	>	if (sl != null)
1044	>	sl.red = false;
1045	>	xpr.red = true;
1046	>	rotateRight(xpr);
1047	>	xpr = (xp = x.parent) == null ?
1048	>	null : xp.right;
1049	>	}
1050	>	if (xpr != null) {
1051	>	xpr.red = (xp == null) ? false : xp.red;
1052	>	if ((sr = xpr.right) != null)
1053	>	sr.red = false;
1054	>	}
1055	>	if (xp != null) {
1056	>	xp.red = false;
1057	>	rotateLeft(xp);
1058	>	}
1059	>	x = root;
1060	>	}
1061	>	}
1062	>	}
1063	>	else { // symmetric
1064	>	if (xpl != null && xpl.red) {
1065	>	xpl.red = false;
1066	>	xp.red = true;
1067	>	rotateRight(xp);
1068	>	xpl = (xp = x.parent) == null ? null : xp.left;
1069	>	}
1070	>	if (xpl == null)
1071	>	x = xp;
1072	>	else {
1073	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
1074	>	if ((sl == null || !sl.red) &&
1075	>	(sr == null || !sr.red)) {
1076	>	xpl.red = true;
1077	>	x = xp;
1078	>	}
1079	>	else {
1080	>	if (sl == null || !sl.red) {
1081	>	if (sr != null)
1082	>	sr.red = false;
1083	>	xpl.red = true;
1084	>	rotateLeft(xpl);
1085	>	xpl = (xp = x.parent) == null ?
1086	>	null : xp.left;
1087	>	}
1088	>	if (xpl != null) {
1089	>	xpl.red = (xp == null) ? false : xp.red;
1090	>	if ((sl = xpl.left) != null)
1091	>	sl.red = false;
1092	>	}
1093	>	if (xp != null) {
1094	>	xp.red = false;
1095	>	rotateRight(xp);
1096	>	}
1097	>	x = root;
1098	>	}
1099	>	}
1100	>	}
1101	>	}
1102	>	}
1103	>	if (p == replacement) {  // detach pointers
1104	>	TreeNode<K,V> pp;
1105	>	if ((pp = p.parent) != null) {
1106	>	if (p == pp.left)
1107	>	pp.left = null;
1108	>	else if (p == pp.right)
1109	>	pp.right = null;
1110	>	p.parent = null;
1111	>	}
1112	>	}
1113	>	assert checkInvariants();
1114	>	}
1115
1116	<	Segment(int initialCapacity, float lf) {
1117	<	loadFactor = lf;
1118	<	setTable(new HashEntry[initialCapacity]);
1116	>	/**
1117	>	* Checks linkage and balance invariants at root
1118	>	*/
1119	>	final boolean checkInvariants() {
1120	>	TreeNode<K,V> r = root;
1121	>	if (r == null)
1122	>	return (first == null);
1123	>	else
1124	>	return (first != null) && checkTreeNode(r);
1125		}
1126
1127		/**
1128	<	* Set table to new HashEntry array.
1129	<	* Call only while holding lock or in constructor.
1130	<	**/
1131	<	private void setTable(HashEntry[] newTable) {
1132	<	table = newTable;
1133	<	threshold = (int)(newTable.length * loadFactor);
1134	<	count = count; // write-volatile
1135	<	}
1136	<
1137	<	/* Specialized implementations of map methods */
1138	<
1139	<	V get(Object key, int hash) {
1140	<	if (count != 0) { // read-volatile
1141	<	HashEntry[] tab = table;
1142	<	int index = hash & (tab.length - 1);
1143	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1144	<	while (e != null) {
1145	<	if (e.hash == hash && key.equals(e.key))
1146	<	return e.value;
1147	<	e = e.next;
1128	>	* Recursive invariant check
1129	>	*/
1130	>	final boolean checkTreeNode(TreeNode<K,V> t) {
1131	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
1132	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
1133	>	if (tb != null && tb.next != t)
1134	>	return false;
1135	>	if (tn != null && tn.prev != t)
1136	>	return false;
1137	>	if (tp != null && t != tp.left && t != tp.right)
1138	>	return false;
1139	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
1140	>	return false;
1141	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
1142	>	return false;
1143	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
1144	>	return false;
1145	>	if (tl != null && !checkTreeNode(tl))
1146	>	return false;
1147	>	if (tr != null && !checkTreeNode(tr))
1148	>	return false;
1149	>	return true;
1150	>	}
1151	>	}
1152	>
1153	>	/* ---------------- Collision reduction methods -------------- */
1154	>
1155	>	/**
1156	>	* Spreads higher bits to lower, and also forces top bit to 0.
1157	>	* Because the table uses power-of-two masking, sets of hashes
1158	>	* that vary only in bits above the current mask will always
1159	>	* collide. (Among known examples are sets of Float keys holding
1160	>	* consecutive whole numbers in small tables.)  To counter this,
1161	>	* we apply a transform that spreads the impact of higher bits
1162	>	* downward. There is a tradeoff between speed, utility, and
1163	>	* quality of bit-spreading. Because many common sets of hashes
1164	>	* are already reasonably distributed across bits (so don't benefit
1165	>	* from spreading), and because we use trees to handle large sets
1166	>	* of collisions in bins, we don't need excessively high quality.
1167	>	*/
1168	>	private static final int spread(int h) {
1169	>	h ^= (h >>> 18) ^ (h >>> 12);
1170	>	return (h ^ (h >>> 10)) & HASH_BITS;
1171	>	}
1172	>
1173	>	/**
1174	>	* Replaces a list bin with a tree bin if key is comparable.  Call
1175	>	* only when locked.
1176	>	*/
1177	>	private final void replaceWithTreeBin(Node<K,V>[] tab, int index, Object key) {
1178	>	if (tab != null && comparableClassFor(key.getClass()) != null) {
1179	>	TreeBin<K,V> t = new TreeBin<K,V>();
1180	>	for (Node<K,V> e = tabAt(tab, index); e != null; e = e.next)
1181	>	t.putTreeNode(e.hash, e.key, e.val);
1182	>	setTabAt(tab, index, new Node<K,V>(MOVED, t, null, null));
1183	>	}
1184	>	}
1185	>
1186	>	/* ---------------- Internal access and update methods -------------- */
1187	>
1188	>	/** Implementation for get and containsKey */
1189	>	private final V internalGet(Object k) {
1190	>	int h = spread(k.hashCode());
1191	>	V v = null;
1192	>	Node<K,V>[] tab; Node<K,V> e;
1193	>	if ((tab = table) != null &&
1194	>	(e = tabAt(tab, (tab.length - 1) & h)) != null) {
1195	>	for (;;) {
1196	>	int eh; Object ek;
1197	>	if ((eh = e.hash) < 0) {
1198	>	if ((ek = e.key) instanceof TreeBin) { // search TreeBin
1199	>	v = ((TreeBin<K,V>)ek).getValue(h, k);
1200	>	break;
1201	>	}
1202	>	else if (!(ek instanceof Node[]) ||    // try new table
1203	>	(e = tabAt(tab = (Node<K,V>[])ek,
1204	>	(tab.length - 1) & h)) == null)
1205	>	break;
1206	>	}
1207	>	else if (eh == h && ((ek = e.key) == k || k.equals(ek))) {
1208	>	v = e.val;
1209	>	break;
1210		}
1211	+	else if ((e = e.next) == null)
1212	+	break;
1213		}
263	–	return null;
1214		}
1215	+	return v;
1216	+	}
1217
1218	<	boolean containsKey(Object key, int hash) {
1219	<	if (count != 0) { // read-volatile
1220	<	HashEntry[] tab = table;
1221	<	int index = hash & (tab.length - 1);
1222	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1223	<	while (e != null) {
1224	<	if (e.hash == hash && key.equals(e.key))
1225	<	return true;
1226	<	e = e.next;
1218	>	/**
1219	>	* Implementation for the four public remove/replace methods:
1220	>	* Replaces node value with v, conditional upon match of cv if
1221	>	* non-null.  If resulting value is null, delete.
1222	>	*/
1223	>	private final V internalReplace(Object k, V v, Object cv) {
1224	>	int h = spread(k.hashCode());
1225	>	V oldVal = null;
1226	>	for (Node<K,V>[] tab = table;;) {
1227	>	Node<K,V> f; int i, fh; Object fk;
1228	>	if (tab == null ||
1229	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1230	>	break;
1231	>	else if ((fh = f.hash) < 0) {
1232	>	if ((fk = f.key) instanceof TreeBin) {
1233	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1234	>	long stamp = t.writeLock();
1235	>	boolean validated = false;
1236	>	boolean deleted = false;
1237	>	try {
1238	>	if (tabAt(tab, i) == f) {
1239	>	validated = true;
1240	>	Class<?> cc = comparableClassFor(k.getClass());
1241	>	TreeNode<K,V> p = t.getTreeNode(h, k, t.root, cc);
1242	>	if (p != null) {
1243	>	V pv = p.val;
1244	>	if (cv == null || cv == pv || cv.equals(pv)) {
1245	>	oldVal = pv;
1246	>	if (v != null)
1247	>	p.val = v;
1248	>	else {
1249	>	deleted = true;
1250	>	t.deleteTreeNode(p);
1251	>	}
1252	>	}
1253	>	}
1254	>	}
1255	>	} finally {
1256	>	t.unlockWrite(stamp);
1257	>	}
1258	>	if (validated) {
1259	>	if (deleted)
1260	>	addCount(-1L, -1);
1261	>	break;
1262	>	}
1263	>	}
1264	>	else
1265	>	tab = (Node<K,V>[])fk;
1266	>	}
1267	>	else {
1268	>	boolean validated = false;
1269	>	boolean deleted = false;
1270	>	synchronized (f) {
1271	>	if (tabAt(tab, i) == f) {
1272	>	validated = true;
1273	>	for (Node<K,V> e = f, pred = null;;) {
1274	>	Object ek;
1275	>	if (e.hash == h &&
1276	>	((ek = e.key) == k || k.equals(ek))) {
1277	>	V ev = e.val;
1278	>	if (cv == null || cv == ev || cv.equals(ev)) {
1279	>	oldVal = ev;
1280	>	if (v != null)
1281	>	e.val = v;
1282	>	else {
1283	>	deleted = true;
1284	>	Node<K,V> en = e.next;
1285	>	if (pred != null)
1286	>	pred.next = en;
1287	>	else
1288	>	setTabAt(tab, i, en);
1289	>	}
1290	>	}
1291	>	break;
1292	>	}
1293	>	pred = e;
1294	>	if ((e = e.next) == null)
1295	>	break;
1296	>	}
1297	>	}
1298	>	}
1299	>	if (validated) {
1300	>	if (deleted)
1301	>	addCount(-1L, -1);
1302	>	break;
1303		}
1304		}
277	–	return false;
1305		}
1306	+	return oldVal;
1307	+	}
1308
1309	<	boolean containsValue(Object value) {
1310	<	if (count != 0) { // read-volatile
1311	<	HashEntry[] tab = table;
1312	<	int len = tab.length;
1313	<	for (int i = 0 ; i < len; i++)
1314	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
1315	<	if (value.equals(e.value))
1316	<	return true;
1309	>	/*
1310	>	* Internal versions of insertion methods
1311	>	* All have the same basic structure as the first (internalPut):
1312	>	*  1. If table uninitialized, create
1313	>	*  2. If bin empty, try to CAS new node
1314	>	*  3. If bin stale, use new table
1315	>	*  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1316	>	*  5. Lock and validate; if valid, scan and add or update
1317	>	*
1318	>	* The putAll method differs mainly in attempting to pre-allocate
1319	>	* enough table space, and also more lazily performs count updates
1320	>	* and checks.
1321	>	*
1322	>	* Most of the function-accepting methods can't be factored nicely
1323	>	* because they require different functional forms, so instead
1324	>	* sprawl out similar mechanics.
1325	>	*/
1326	>
1327	>	/** Implementation for put and putIfAbsent */
1328	>	private final V internalPut(K k, V v, boolean onlyIfAbsent) {
1329	>	if (k == null || v == null) throw new NullPointerException();
1330	>	int h = spread(k.hashCode());
1331	>	int len = 0;
1332	>	for (Node<K,V>[] tab = table;;) {
1333	>	int i, fh; Node<K,V> f; Object fk;
1334	>	if (tab == null)
1335	>	tab = initTable();
1336	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1337	>	if (casTabAt(tab, i, null, new Node<K,V>(h, k, v, null)))
1338	>	break;                   // no lock when adding to empty bin
1339	>	}
1340	>	else if ((fh = f.hash) < 0) {
1341	>	if ((fk = f.key) instanceof TreeBin) {
1342	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1343	>	long stamp = t.writeLock();
1344	>	V oldVal = null;
1345	>	try {
1346	>	if (tabAt(tab, i) == f) {
1347	>	len = 2;
1348	>	TreeNode<K,V> p = t.putTreeNode(h, k, v);
1349	>	if (p != null) {
1350	>	oldVal = p.val;
1351	>	if (!onlyIfAbsent)
1352	>	p.val = v;
1353	>	}
1354	>	}
1355	>	} finally {
1356	>	t.unlockWrite(stamp);
1357	>	}
1358	>	if (len != 0) {
1359	>	if (oldVal != null)
1360	>	return oldVal;
1361	>	break;
1362	>	}
1363	>	}
1364	>	else
1365	>	tab = (Node<K,V>[])fk;
1366	>	}
1367	>	else {
1368	>	V oldVal = null;
1369	>	synchronized (f) {
1370	>	if (tabAt(tab, i) == f) {
1371	>	len = 1;
1372	>	for (Node<K,V> e = f;; ++len) {
1373	>	Object ek;
1374	>	if (e.hash == h &&
1375	>	((ek = e.key) == k || k.equals(ek))) {
1376	>	oldVal = e.val;
1377	>	if (!onlyIfAbsent)
1378	>	e.val = v;
1379	>	break;
1380	>	}
1381	>	Node<K,V> last = e;
1382	>	if ((e = e.next) == null) {
1383	>	last.next = new Node<K,V>(h, k, v, null);
1384	>	if (len > TREE_THRESHOLD)
1385	>	replaceWithTreeBin(tab, i, k);
1386	>	break;
1387	>	}
1388	>	}
1389	>	}
1390	>	}
1391	>	if (len != 0) {
1392	>	if (oldVal != null)
1393	>	return oldVal;
1394	>	break;
1395	>	}
1396		}
289	–	return false;
1397		}
1398	+	addCount(1L, len);
1399	+	return null;
1400	+	}
1401
1402	<	boolean replace(K key, int hash, V oldValue, V newValue) {
1403	<	lock();
1404	<	try {
1405	<	int c = count;
1406	<	HashEntry[] tab = table;
1407	<	int index = hash & (tab.length - 1);
1408	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1409	<	HashEntry<K,V> e = first;
1410	<	for (;;) {
1411	<	if (e == null)
1412	<	return false;
1413	<	if (e.hash == hash && key.equals(e.key))
1402	>	/** Implementation for computeIfAbsent */
1403	>	private final V internalComputeIfAbsent(K k, Function<? super K, ? extends V> mf) {
1404	>	if (k == null || mf == null)
1405	>	throw new NullPointerException();
1406	>	int h = spread(k.hashCode());
1407	>	V val = null;
1408	>	int len = 0;
1409	>	for (Node<K,V>[] tab = table;;) {
1410	>	Node<K,V> f; int i; Object fk;
1411	>	if (tab == null)
1412	>	tab = initTable();
1413	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1414	>	Node<K,V> node = new Node<K,V>(h, k, null, null);
1415	>	synchronized (node) {
1416	>	if (casTabAt(tab, i, null, node)) {
1417	>	len = 1;
1418	>	try {
1419	>	if ((val = mf.apply(k)) != null)
1420	>	node.val = val;
1421	>	} finally {
1422	>	if (val == null)
1423	>	setTabAt(tab, i, null);
1424	>	}
1425	>	}
1426	>	}
1427	>	if (len != 0)
1428	>	break;
1429	>	}
1430	>	else if (f.hash < 0) {
1431	>	if ((fk = f.key) instanceof TreeBin) {
1432	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1433	>	long stamp = t.writeLock();
1434	>	boolean added = false;
1435	>	try {
1436	>	if (tabAt(tab, i) == f) {
1437	>	len = 2;
1438	>	Class<?> cc = comparableClassFor(k.getClass());
1439	>	TreeNode<K,V> p = t.getTreeNode(h, k, t.root, cc);
1440	>	if (p != null)
1441	>	val = p.val;
1442	>	else if ((val = mf.apply(k)) != null) {
1443	>	added = true;
1444	>	t.putTreeNode(h, k, val);
1445	>	}
1446	>	}
1447	>	} finally {
1448	>	t.unlockWrite(stamp);
1449	>	}
1450	>	if (len != 0) {
1451	>	if (!added)
1452	>	return val;
1453		break;
1454	<	e = e.next;
1454	>	}
1455	>	}
1456	>	else
1457	>	tab = (Node<K,V>[])fk;
1458	>	}
1459	>	else {
1460	>	boolean added = false;
1461	>	synchronized (f) {
1462	>	if (tabAt(tab, i) == f) {
1463	>	len = 1;
1464	>	for (Node<K,V> e = f;; ++len) {
1465	>	Object ek; V ev;
1466	>	if (e.hash == h &&
1467	>	((ek = e.key) == k || k.equals(ek))) {
1468	>	val = e.val;
1469	>	break;
1470	>	}
1471	>	Node<K,V> last = e;
1472	>	if ((e = e.next) == null) {
1473	>	if ((val = mf.apply(k)) != null) {
1474	>	added = true;
1475	>	last.next = new Node<K,V>(h, k, val, null);
1476	>	if (len > TREE_THRESHOLD)
1477	>	replaceWithTreeBin(tab, i, k);
1478	>	}
1479	>	break;
1480	>	}
1481	>	}
1482	>	}
1483	>	}
1484	>	if (len != 0) {
1485	>	if (!added)
1486	>	return val;
1487	>	break;
1488		}
307	–
308	–	V v = e.value;
309	–	if (v == null || !oldValue.equals(v))
310	–	return false;
311	–
312	–	e.value = newValue;
313	–	count = c; // write-volatile
314	–	return true;
315	–
316	–	} finally {
317	–	unlock();
1489		}
1490		}
1491	+	if (val != null)
1492	+	addCount(1L, len);
1493	+	return val;
1494	+	}
1495
1496	<	V replace(K key, int hash, V newValue) {
1497	<	lock();
1498	<	try {
1499	<	int c = count;
1500	<	HashEntry[] tab = table;
1501	<	int index = hash & (tab.length - 1);
1502	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1503	<	HashEntry<K,V> e = first;
1504	<	for (;;) {
1505	<	if (e == null)
1506	<	return null;
1507	<	if (e.hash == hash && key.equals(e.key))
1496	>	/** Implementation for compute */
1497	>	private final V internalCompute(K k, boolean onlyIfPresent,
1498	>	BiFunction<? super K, ? super V, ? extends V> mf) {
1499	>	if (k == null || mf == null)
1500	>	throw new NullPointerException();
1501	>	int h = spread(k.hashCode());
1502	>	V val = null;
1503	>	int delta = 0;
1504	>	int len = 0;
1505	>	for (Node<K,V>[] tab = table;;) {
1506	>	Node<K,V> f; int i, fh; Object fk;
1507	>	if (tab == null)
1508	>	tab = initTable();
1509	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1510	>	if (onlyIfPresent)
1511	>	break;
1512	>	Node<K,V> node = new Node<K,V>(h, k, null, null);
1513	>	synchronized (node) {
1514	>	if (casTabAt(tab, i, null, node)) {
1515	>	try {
1516	>	len = 1;
1517	>	if ((val = mf.apply(k, null)) != null) {
1518	>	node.val = val;
1519	>	delta = 1;
1520	>	}
1521	>	} finally {
1522	>	if (delta == 0)
1523	>	setTabAt(tab, i, null);
1524	>	}
1525	>	}
1526	>	}
1527	>	if (len != 0)
1528	>	break;
1529	>	}
1530	>	else if ((fh = f.hash) < 0) {
1531	>	if ((fk = f.key) instanceof TreeBin) {
1532	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1533	>	long stamp = t.writeLock();
1534	>	try {
1535	>	if (tabAt(tab, i) == f) {
1536	>	len = 2;
1537	>	Class<?> cc = comparableClassFor(k.getClass());
1538	>	TreeNode<K,V> p = t.getTreeNode(h, k, t.root, cc);
1539	>	if (p != null || !onlyIfPresent) {
1540	>	V pv = (p == null) ? null : p.val;
1541	>	if ((val = mf.apply(k, pv)) != null) {
1542	>	if (p != null)
1543	>	p.val = val;
1544	>	else {
1545	>	delta = 1;
1546	>	t.putTreeNode(h, k, val);
1547	>	}
1548	>	}
1549	>	else if (p != null) {
1550	>	delta = -1;
1551	>	t.deleteTreeNode(p);
1552	>	}
1553	>	}
1554	>	}
1555	>	} finally {
1556	>	t.unlockWrite(stamp);
1557	>	}
1558	>	if (len != 0)
1559		break;
334	–	e = e.next;
1560		}
1561	<
1562	<	V v = e.value;
1563	<	e.value = newValue;
1564	<	count = c; // write-volatile
1565	<	return v;
1566	<
1567	<	} finally {
1568	<	unlock();
1561	>	else
1562	>	tab = (Node<K,V>[])fk;
1563	>	}
1564	>	else {
1565	>	synchronized (f) {
1566	>	if (tabAt(tab, i) == f) {
1567	>	len = 1;
1568	>	for (Node<K,V> e = f, pred = null;; ++len) {
1569	>	Object ek;
1570	>	if (e.hash == h &&
1571	>	((ek = e.key) == k || k.equals(ek))) {
1572	>	val = mf.apply(k, e.val);
1573	>	if (val != null)
1574	>	e.val = val;
1575	>	else {
1576	>	delta = -1;
1577	>	Node<K,V> en = e.next;
1578	>	if (pred != null)
1579	>	pred.next = en;
1580	>	else
1581	>	setTabAt(tab, i, en);
1582	>	}
1583	>	break;
1584	>	}
1585	>	pred = e;
1586	>	if ((e = e.next) == null) {
1587	>	if (!onlyIfPresent &&
1588	>	(val = mf.apply(k, null)) != null) {
1589	>	pred.next = new Node<K,V>(h, k, val, null);
1590	>	delta = 1;
1591	>	if (len > TREE_THRESHOLD)
1592	>	replaceWithTreeBin(tab, i, k);
1593	>	}
1594	>	break;
1595	>	}
1596	>	}
1597	>	}
1598	>	}
1599	>	if (len != 0)
1600	>	break;
1601		}
1602		}
1603	+	if (delta != 0)
1604	+	addCount((long)delta, len);
1605	+	return val;
1606	+	}
1607
1608	<
1609	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1610	<	lock();
1611	<	try {
1612	<	int c = count;
1613	<	HashEntry[] tab = table;
1614	<	int index = hash & (tab.length - 1);
1615	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1616	<
1617	<	for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
1618	<	if (e.hash == hash && key.equals(e.key)) {
1619	<	V oldValue = e.value;
1620	<	if (!onlyIfAbsent)
1621	<	e.value = value;
1622	<	++modCount;
1623	<	count = c; // write-volatile
1624	<	return oldValue;
1608	>	/** Implementation for merge */
1609	>	private final V internalMerge(K k, V v,
1610	>	BiFunction<? super V, ? super V, ? extends V> mf) {
1611	>	if (k == null || v == null || mf == null)
1612	>	throw new NullPointerException();
1613	>	int h = spread(k.hashCode());
1614	>	V val = null;
1615	>	int delta = 0;
1616	>	int len = 0;
1617	>	for (Node<K,V>[] tab = table;;) {
1618	>	int i; Node<K,V> f; Object fk;
1619	>	if (tab == null)
1620	>	tab = initTable();
1621	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1622	>	if (casTabAt(tab, i, null, new Node<K,V>(h, k, v, null))) {
1623	>	delta = 1;
1624	>	val = v;
1625	>	break;
1626	>	}
1627	>	}
1628	>	else if (f.hash < 0) {
1629	>	if ((fk = f.key) instanceof TreeBin) {
1630	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1631	>	long stamp = t.writeLock();
1632	>	try {
1633	>	if (tabAt(tab, i) == f) {
1634	>	len = 2;
1635	>	Class<?> cc = comparableClassFor(k.getClass());
1636	>	TreeNode<K,V> p = t.getTreeNode(h, k, t.root, cc);
1637	>	val = (p == null) ? v : mf.apply(p.val, v);
1638	>	if (val != null) {
1639	>	if (p != null)
1640	>	p.val = val;
1641	>	else {
1642	>	delta = 1;
1643	>	t.putTreeNode(h, k, val);
1644	>	}
1645	>	}
1646	>	else if (p != null) {
1647	>	delta = -1;
1648	>	t.deleteTreeNode(p);
1649	>	}
1650	>	}
1651	>	} finally {
1652	>	t.unlockWrite(stamp);
1653		}
1654	+	if (len != 0)
1655	+	break;
1656		}
1657	<
1658	<	tab[index] = new HashEntry<K,V>(hash, key, value, first);
1659	<	++modCount;
1660	<	++c;
1661	<	count = c; // write-volatile
1662	<	if (c > threshold)
1663	<	setTable(rehash(tab));
1664	<	return null;
1665	<	} finally {
1666	<	unlock();
1657	>	else
1658	>	tab = (Node<K,V>[])fk;
1659	>	}
1660	>	else {
1661	>	synchronized (f) {
1662	>	if (tabAt(tab, i) == f) {
1663	>	len = 1;
1664	>	for (Node<K,V> e = f, pred = null;; ++len) {
1665	>	Object ek;
1666	>	if (e.hash == h &&
1667	>	((ek = e.key) == k || k.equals(ek))) {
1668	>	val = mf.apply(e.val, v);
1669	>	if (val != null)
1670	>	e.val = val;
1671	>	else {
1672	>	delta = -1;
1673	>	Node<K,V> en = e.next;
1674	>	if (pred != null)
1675	>	pred.next = en;
1676	>	else
1677	>	setTabAt(tab, i, en);
1678	>	}
1679	>	break;
1680	>	}
1681	>	pred = e;
1682	>	if ((e = e.next) == null) {
1683	>	delta = 1;
1684	>	val = v;
1685	>	pred.next = new Node<K,V>(h, k, val, null);
1686	>	if (len > TREE_THRESHOLD)
1687	>	replaceWithTreeBin(tab, i, k);
1688	>	break;
1689	>	}
1690	>	}
1691	>	}
1692	>	}
1693	>	if (len != 0)
1694	>	break;
1695		}
1696		}
1697	+	if (delta != 0)
1698	+	addCount((long)delta, len);
1699	+	return val;
1700	+	}
1701
1702	<	private HashEntry[] rehash(HashEntry[] oldTable) {
1703	<	int oldCapacity = oldTable.length;
1704	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1705	<	return oldTable;
1706	<
1707	<	/*
1708	<	* Reclassify nodes in each list to new Map.  Because we are
1709	<	* using power-of-two expansion, the elements from each bin
1710	<	* must either stay at same index, or move with a power of two
1711	<	* offset. We eliminate unnecessary node creation by catching
1712	<	* cases where old nodes can be reused because their next
1713	<	* fields won't change. Statistically, at the default
1714	<	* threshold, only about one-sixth of them need cloning when
1715	<	* a table doubles. The nodes they replace will be garbage
1716	<	* collectable as soon as they are no longer referenced by any
1717	<	* reader thread that may be in the midst of traversing table
1718	<	* right now.
1719	<	*/
1720	<
1721	<	HashEntry[] newTable = new HashEntry[oldCapacity << 1];
1722	<	int sizeMask = newTable.length - 1;
1723	<	for (int i = 0; i < oldCapacity ; i++) {
1724	<	// We need to guarantee that any existing reads of old Map can
1725	<	//  proceed. So we cannot yet null out each bin.
1726	<	HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
1727	<
1728	<	if (e != null) {
1729	<	HashEntry<K,V> next = e.next;
1730	<	int idx = e.hash & sizeMask;
1731	<
1732	<	//  Single node on list
1733	<	if (next == null)
1734	<	newTable[idx] = e;
1735	<
1702	>	/** Implementation for putAll */
1703	>	private final void internalPutAll(Map<? extends K, ? extends V> m) {
1704	>	tryPresize(m.size());
1705	>	long delta = 0L;     // number of uncommitted additions
1706	>	boolean npe = false; // to throw exception on exit for nulls
1707	>	try {                // to clean up counts on other exceptions
1708	>	for (Map.Entry<?, ? extends V> entry : m.entrySet()) {
1709	>	Object k; V v;
1710	>	if (entry == null || (k = entry.getKey()) == null ||
1711	>	(v = entry.getValue()) == null) {
1712	>	npe = true;
1713	>	break;
1714	>	}
1715	>	int h = spread(k.hashCode());
1716	>	for (Node<K,V>[] tab = table;;) {
1717	>	int i; Node<K,V> f; int fh; Object fk;
1718	>	if (tab == null)
1719	>	tab = initTable();
1720	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1721	>	if (casTabAt(tab, i, null, new Node<K,V>(h, k, v, null))) {
1722	>	++delta;
1723	>	break;
1724	>	}
1725	>	}
1726	>	else if ((fh = f.hash) < 0) {
1727	>	if ((fk = f.key) instanceof TreeBin) {
1728	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1729	>	long stamp = t.writeLock();
1730	>	boolean validated = false;
1731	>	try {
1732	>	if (tabAt(tab, i) == f) {
1733	>	validated = true;
1734	>	Class<?> cc = comparableClassFor(k.getClass());
1735	>	TreeNode<K,V> p = t.getTreeNode(h, k,
1736	>	t.root, cc);
1737	>	if (p != null)
1738	>	p.val = v;
1739	>	else {
1740	>	++delta;
1741	>	t.putTreeNode(h, k, v);
1742	>	}
1743	>	}
1744	>	} finally {
1745	>	t.unlockWrite(stamp);
1746	>	}
1747	>	if (validated)
1748	>	break;
1749	>	}
1750	>	else
1751	>	tab = (Node<K,V>[])fk;
1752	>	}
1753		else {
1754	<	// Reuse trailing consecutive sequence at same slot
1755	<	HashEntry<K,V> lastRun = e;
1756	<	int lastIdx = idx;
1757	<	for (HashEntry<K,V> last = next;
1758	<	last != null;
1759	<	last = last.next) {
1760	<	int k = last.hash & sizeMask;
1761	<	if (k != lastIdx) {
1762	<	lastIdx = k;
1763	<	lastRun = last;
1754	>	int len = 0;
1755	>	synchronized (f) {
1756	>	if (tabAt(tab, i) == f) {
1757	>	len = 1;
1758	>	for (Node<K,V> e = f;; ++len) {
1759	>	Object ek;
1760	>	if (e.hash == h &&
1761	>	((ek = e.key) == k || k.equals(ek))) {
1762	>	e.val = v;
1763	>	break;
1764	>	}
1765	>	Node<K,V> last = e;
1766	>	if ((e = e.next) == null) {
1767	>	++delta;
1768	>	last.next = new Node<K,V>(h, k, v, null);
1769	>	if (len > TREE_THRESHOLD)
1770	>	replaceWithTreeBin(tab, i, k);
1771	>	break;
1772	>	}
1773	>	}
1774	>	}
1775	>	}
1776	>	if (len != 0) {
1777	>	if (len > 1) {
1778	>	addCount(delta, len);
1779	>	delta = 0L;
1780		}
1781	+	break;
1782		}
1783	<	newTable[lastIdx] = lastRun;
1783	>	}
1784	>	}
1785	>	}
1786	>	} finally {
1787	>	if (delta != 0L)
1788	>	addCount(delta, 2);
1789	>	}
1790	>	if (npe)
1791	>	throw new NullPointerException();
1792	>	}
1793
1794	<	// Clone all remaining nodes
1795	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1796	<	int k = p.hash & sizeMask;
1797	<	newTable[k] = new HashEntry<K,V>(p.hash,
1798	<	p.key,
1799	<	p.value,
1800	<	(HashEntry<K,V>) newTable[k]);
1794	>	/**
1795	>	* Implementation for clear. Steps through each bin, removing all
1796	>	* nodes.
1797	>	*/
1798	>	private final void internalClear() {
1799	>	long delta = 0L; // negative number of deletions
1800	>	int i = 0;
1801	>	Node<K,V>[] tab = table;
1802	>	while (tab != null && i < tab.length) {
1803	>	Node<K,V> f = tabAt(tab, i);
1804	>	if (f == null)
1805	>	++i;
1806	>	else if (f.hash < 0) {
1807	>	Object fk;
1808	>	if ((fk = f.key) instanceof TreeBin) {
1809	>	TreeBin<K,V> t = (TreeBin<K,V>)fk;
1810	>	long stamp = t.writeLock();
1811	>	try {
1812	>	if (tabAt(tab, i) == f) {
1813	>	for (Node<K,V> p = t.first; p != null; p = p.next)
1814	>	--delta;
1815	>	t.first = null;
1816	>	t.root = null;
1817	>	++i;
1818		}
1819	+	} finally {
1820	+	t.unlockWrite(stamp);
1821	+	}
1822	+	}
1823	+	else
1824	+	tab = (Node<K,V>[])fk;
1825	+	}
1826	+	else {
1827	+	synchronized (f) {
1828	+	if (tabAt(tab, i) == f) {
1829	+	for (Node<K,V> e = f; e != null; e = e.next)
1830	+	--delta;
1831	+	setTabAt(tab, i, null);
1832	+	++i;
1833		}
1834		}
1835		}
439	–	return newTable;
1836		}
1837	+	if (delta != 0L)
1838	+	addCount(delta, -1);
1839	+	}
1840
1841	<	/**
443	<	* Remove; match on key only if value null, else match both.
444	<	*/
445	<	V remove(Object key, int hash, Object value) {
446	<	lock();
447	<	try {
448	<	int c = count;
449	<	HashEntry[] tab = table;
450	<	int index = hash & (tab.length - 1);
451	<	HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
1841	>	/* ---------------- Table Initialization and Resizing -------------- */
1842
1843	<	HashEntry<K,V> e = first;
1844	<	for (;;) {
1845	<	if (e == null)
1846	<	return null;
1847	<	if (e.hash == hash && key.equals(e.key))
1843	>	/**
1844	>	* Returns a power of two table size for the given desired capacity.
1845	>	* See Hackers Delight, sec 3.2
1846	>	*/
1847	>	private static final int tableSizeFor(int c) {
1848	>	int n = c - 1;
1849	>	n |= n >>> 1;
1850	>	n |= n >>> 2;
1851	>	n |= n >>> 4;
1852	>	n |= n >>> 8;
1853	>	n |= n >>> 16;
1854	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1855	>	}
1856	>
1857	>	/**
1858	>	* Initializes table, using the size recorded in sizeCtl.
1859	>	*/
1860	>	private final Node<K,V>[] initTable() {
1861	>	Node<K,V>[] tab; int sc;
1862	>	while ((tab = table) == null) {
1863	>	if ((sc = sizeCtl) < 0)
1864	>	Thread.yield(); // lost initialization race; just spin
1865	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1866	>	try {
1867	>	if ((tab = table) == null) {
1868	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1869	>	table = tab = (Node<K,V>[])new Node[n];
1870	>	sc = n - (n >>> 2);
1871	>	}
1872	>	} finally {
1873	>	sizeCtl = sc;
1874	>	}
1875	>	break;
1876	>	}
1877	>	}
1878	>	return tab;
1879	>	}
1880	>
1881	>	/**
1882	>	* Adds to count, and if table is too small and not already
1883	>	* resizing, initiates transfer. If already resizing, helps
1884	>	* perform transfer if work is available.  Rechecks occupancy
1885	>	* after a transfer to see if another resize is already needed
1886	>	* because resizings are lagging additions.
1887	>	*
1888	>	* @param x the count to add
1889	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
1890	>	*/
1891	>	private final void addCount(long x, int check) {
1892	>	Cell[] as; long b, s;
1893	>	if ((as = counterCells) != null ||
1894	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1895	>	Cell a; long v; int m;
1896	>	boolean uncontended = true;
1897	>	if (as == null || (m = as.length - 1) < 0 ||
1898	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
1899	>	!(uncontended =
1900	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1901	>	fullAddCount(x, uncontended);
1902	>	return;
1903	>	}
1904	>	if (check <= 1)
1905	>	return;
1906	>	s = sumCount();
1907	>	}
1908	>	if (check >= 0) {
1909	>	Node<K,V>[] tab, nt; int sc;
1910	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1911	>	tab.length < MAXIMUM_CAPACITY) {
1912	>	if (sc < 0) {
1913	>	if (sc == -1 || transferIndex <= transferOrigin ||
1914	>	(nt = nextTable) == null)
1915		break;
1916	<	e = e.next;
1916	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1917	>	transfer(tab, nt);
1918		}
1919	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1920	+	transfer(tab, null);
1921	+	s = sumCount();
1922	+	}
1923	+	}
1924	+	}
1925
1926	<	V oldValue = e.value;
1927	<	if (value != null && !value.equals(oldValue))
1928	<	return null;
1929	<
1930	<	// All entries following removed node can stay in list, but
1931	<	// all preceding ones need to be cloned.
1932	<	HashEntry<K,V> newFirst = e.next;
1933	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
1934	<	newFirst = new HashEntry<K,V>(p.hash, p.key,
1935	<	p.value, newFirst);
1936	<	tab[index] = newFirst;
1937	<	++modCount;
1938	<	count = c-1; // write-volatile
1939	<	return oldValue;
1940	<	} finally {
1941	<	unlock();
1926	>	/**
1927	>	* Tries to presize table to accommodate the given number of elements.
1928	>	*
1929	>	* @param size number of elements (doesn't need to be perfectly accurate)
1930	>	*/
1931	>	private final void tryPresize(int size) {
1932	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1933	>	tableSizeFor(size + (size >>> 1) + 1);
1934	>	int sc;
1935	>	while ((sc = sizeCtl) >= 0) {
1936	>	Node<K,V>[] tab = table; int n;
1937	>	if (tab == null || (n = tab.length) == 0) {
1938	>	n = (sc > c) ? sc : c;
1939	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1940	>	try {
1941	>	if (table == tab) {
1942	>	table = (Node<K,V>[])new Node[n];
1943	>	sc = n - (n >>> 2);
1944	>	}
1945	>	} finally {
1946	>	sizeCtl = sc;
1947	>	}
1948	>	}
1949		}
1950	+	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1951	+	break;
1952	+	else if (tab == table &&
1953	+	U.compareAndSwapInt(this, SIZECTL, sc, -2))
1954	+	transfer(tab, null);
1955		}
1956	+	}
1957
1958	<	void clear() {
1959	<	lock();
1958	>	/**
1959	>	* Moves and/or copies the nodes in each bin to new table. See
1960	>	* above for explanation.
1961	>	*/
1962	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
1963	>	int n = tab.length, stride;
1964	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1965	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
1966	>	if (nextTab == null) {            // initiating
1967		try {
1968	<	HashEntry[] tab = table;
1969	<	for (int i = 0; i < tab.length ; i++)
1970	<	tab[i] = null;
1971	<	++modCount;
488	<	count = 0; // write-volatile
489	<	} finally {
490	<	unlock();
1968	>	nextTab = (Node<K,V>[])new Node[n << 1];
1969	>	} catch (Throwable ex) {      // try to cope with OOME
1970	>	sizeCtl = Integer.MAX_VALUE;
1971	>	return;
1972		}
1973	+	nextTable = nextTab;
1974	+	transferOrigin = n;
1975	+	transferIndex = n;
1976	+	Node<K,V> rev = new Node<K,V>(MOVED, tab, null, null);
1977	+	for (int k = n; k > 0;) {    // progressively reveal ready slots
1978	+	int nextk = (k > stride) ? k - stride : 0;
1979	+	for (int m = nextk; m < k; ++m)
1980	+	nextTab[m] = rev;
1981	+	for (int m = n + nextk; m < n + k; ++m)
1982	+	nextTab[m] = rev;
1983	+	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
1984	+	}
1985	+	}
1986	+	int nextn = nextTab.length;
1987	+	Node<K,V> fwd = new Node<K,V>(MOVED, nextTab, null, null);
1988	+	boolean advance = true;
1989	+	for (int i = 0, bound = 0;;) {
1990	+	int nextIndex, nextBound; Node<K,V> f; Object fk;
1991	+	while (advance) {
1992	+	if (--i >= bound)
1993	+	advance = false;
1994	+	else if ((nextIndex = transferIndex) <= transferOrigin) {
1995	+	i = -1;
1996	+	advance = false;
1997	+	}
1998	+	else if (U.compareAndSwapInt
1999	+	(this, TRANSFERINDEX, nextIndex,
2000	+	nextBound = (nextIndex > stride ?
2001	+	nextIndex - stride : 0))) {
2002	+	bound = nextBound;
2003	+	i = nextIndex - 1;
2004	+	advance = false;
2005	+	}
2006	+	}
2007	+	if (i < 0 || i >= n || i + n >= nextn) {
2008	+	for (int sc;;) {
2009	+	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2010	+	if (sc == -1) {
2011	+	nextTable = null;
2012	+	table = nextTab;
2013	+	sizeCtl = (n << 1) - (n >>> 1);
2014	+	}
2015	+	return;
2016	+	}
2017	+	}
2018	+	}
2019	+	else if ((f = tabAt(tab, i)) == null) {
2020	+	if (casTabAt(tab, i, null, fwd)) {
2021	+	setTabAt(nextTab, i, null);
2022	+	setTabAt(nextTab, i + n, null);
2023	+	advance = true;
2024	+	}
2025	+	}
2026	+	else if (f.hash >= 0) {
2027	+	synchronized (f) {
2028	+	if (tabAt(tab, i) == f) {
2029	+	int runBit = f.hash & n;
2030	+	Node<K,V> lastRun = f, lo = null, hi = null;
2031	+	for (Node<K,V> p = f.next; p != null; p = p.next) {
2032	+	int b = p.hash & n;
2033	+	if (b != runBit) {
2034	+	runBit = b;
2035	+	lastRun = p;
2036	+	}
2037	+	}
2038	+	if (runBit == 0)
2039	+	lo = lastRun;
2040	+	else
2041	+	hi = lastRun;
2042	+	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2043	+	int ph = p.hash; Object pk = p.key; V pv = p.val;
2044	+	if ((ph & n) == 0)
2045	+	lo = new Node<K,V>(ph, pk, pv, lo);
2046	+	else
2047	+	hi = new Node<K,V>(ph, pk, pv, hi);
2048	+	}
2049	+	setTabAt(nextTab, i, lo);
2050	+	setTabAt(nextTab, i + n, hi);
2051	+	setTabAt(tab, i, fwd);
2052	+	advance = true;
2053	+	}
2054	+	}
2055	+	}
2056	+	else if ((fk = f.key) instanceof TreeBin) {
2057	+	TreeBin<K,V> t = (TreeBin<K,V>)fk;
2058	+	long stamp = t.writeLock();
2059	+	try {
2060	+	if (tabAt(tab, i) == f) {
2061	+	TreeNode<K,V> root;
2062	+	Node<K,V> ln = null, hn = null;
2063	+	if ((root = t.root) != null) {
2064	+	Node<K,V> e, p; TreeNode<K,V> lr, rr; int lh;
2065	+	TreeBin<K,V> lt = null, ht = null;
2066	+	for (lr = root; lr.left != null; lr = lr.left);
2067	+	for (rr = root; rr.right != null; rr = rr.right);
2068	+	if ((lh = lr.hash) == rr.hash) { // move entire tree
2069	+	if ((lh & n) == 0)
2070	+	lt = t;
2071	+	else
2072	+	ht = t;
2073	+	}
2074	+	else {
2075	+	lt = new TreeBin<K,V>();
2076	+	ht = new TreeBin<K,V>();
2077	+	int lc = 0, hc = 0;
2078	+	for (e = t.first; e != null; e = e.next) {
2079	+	int h = e.hash;
2080	+	Object k = e.key; V v = e.val;
2081	+	if ((h & n) == 0) {
2082	+	++lc;
2083	+	lt.putTreeNode(h, k, v);
2084	+	}
2085	+	else {
2086	+	++hc;
2087	+	ht.putTreeNode(h, k, v);
2088	+	}
2089	+	}
2090	+	if (lc < TREE_THRESHOLD) { // throw away
2091	+	for (p = lt.first; p != null; p = p.next)
2092	+	ln = new Node<K,V>(p.hash, p.key,
2093	+	p.val, ln);
2094	+	lt = null;
2095	+	}
2096	+	if (hc < TREE_THRESHOLD) {
2097	+	for (p = ht.first; p != null; p = p.next)
2098	+	hn = new Node<K,V>(p.hash, p.key,
2099	+	p.val, hn);
2100	+	ht = null;
2101	+	}
2102	+	}
2103	+	if (ln == null && lt != null)
2104	+	ln = new Node<K,V>(MOVED, lt, null, null);
2105	+	if (hn == null && ht != null)
2106	+	hn = new Node<K,V>(MOVED, ht, null, null);
2107	+	}
2108	+	setTabAt(nextTab, i, ln);
2109	+	setTabAt(nextTab, i + n, hn);
2110	+	setTabAt(tab, i, fwd);
2111	+	advance = true;
2112	+	}
2113	+	} finally {
2114	+	t.unlockWrite(stamp);
2115	+	}
2116	+	}
2117	+	else
2118	+	advance = true; // already processed
2119	+	}
2120	+	}
2121	+
2122	+	/* ---------------- Counter support -------------- */
2123	+
2124	+	final long sumCount() {
2125	+	Cell[] as = counterCells; Cell a;
2126	+	long sum = baseCount;
2127	+	if (as != null) {
2128	+	for (int i = 0; i < as.length; ++i) {
2129	+	if ((a = as[i]) != null)
2130	+	sum += a.value;
2131	+	}
2132	+	}
2133	+	return sum;
2134	+	}
2135	+
2136	+	// See LongAdder version for explanation
2137	+	private final void fullAddCount(long x, boolean wasUncontended) {
2138	+	int h;
2139	+	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2140	+	ThreadLocalRandom.localInit();      // force initialization
2141	+	h = ThreadLocalRandom.getProbe();
2142	+	wasUncontended = true;
2143	+	}
2144	+	boolean collide = false;                // True if last slot nonempty
2145	+	for (;;) {
2146	+	Cell[] as; Cell a; int n; long v;
2147	+	if ((as = counterCells) != null && (n = as.length) > 0) {
2148	+	if ((a = as[(n - 1) & h]) == null) {
2149	+	if (cellsBusy == 0) {            // Try to attach new Cell
2150	+	Cell r = new Cell(x); // Optimistic create
2151	+	if (cellsBusy == 0 &&
2152	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2153	+	boolean created = false;
2154	+	try {               // Recheck under lock
2155	+	Cell[] rs; int m, j;
2156	+	if ((rs = counterCells) != null &&
2157	+	(m = rs.length) > 0 &&
2158	+	rs[j = (m - 1) & h] == null) {
2159	+	rs[j] = r;
2160	+	created = true;
2161	+	}
2162	+	} finally {
2163	+	cellsBusy = 0;
2164	+	}
2165	+	if (created)
2166	+	break;
2167	+	continue;           // Slot is now non-empty
2168	+	}
2169	+	}
2170	+	collide = false;
2171	+	}
2172	+	else if (!wasUncontended)       // CAS already known to fail
2173	+	wasUncontended = true;      // Continue after rehash
2174	+	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2175	+	break;
2176	+	else if (counterCells != as || n >= NCPU)
2177	+	collide = false;            // At max size or stale
2178	+	else if (!collide)
2179	+	collide = true;
2180	+	else if (cellsBusy == 0 &&
2181	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2182	+	try {
2183	+	if (counterCells == as) {// Expand table unless stale
2184	+	Cell[] rs = new Cell[n << 1];
2185	+	for (int i = 0; i < n; ++i)
2186	+	rs[i] = as[i];
2187	+	counterCells = rs;
2188	+	}
2189	+	} finally {
2190	+	cellsBusy = 0;
2191	+	}
2192	+	collide = false;
2193	+	continue;                   // Retry with expanded table
2194	+	}
2195	+	h = ThreadLocalRandom.advanceProbe(h);
2196	+	}
2197	+	else if (cellsBusy == 0 && counterCells == as &&
2198	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2199	+	boolean init = false;
2200	+	try {                           // Initialize table
2201	+	if (counterCells == as) {
2202	+	Cell[] rs = new Cell[2];
2203	+	rs[h & 1] = new Cell(x);
2204	+	counterCells = rs;
2205	+	init = true;
2206	+	}
2207	+	} finally {
2208	+	cellsBusy = 0;
2209	+	}
2210	+	if (init)
2211	+	break;
2212	+	}
2213	+	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2214	+	break;                          // Fall back on using base
2215		}
2216		}
2217
2218	+	/* ----------------Table Traversal -------------- */
2219	+
2220		/**
2221	<	* ConcurrentHashMap list entry. Note that this is never exported
2222	<	* out as a user-visible Map.Entry
2221	>	* Encapsulates traversal for methods such as containsValue; also
2222	>	* serves as a base class for other iterators and spliterators.
2223	>	*
2224	>	* Method advance visits once each still-valid node that was
2225	>	* reachable upon iterator construction. It might miss some that
2226	>	* were added to a bin after the bin was visited, which is OK wrt
2227	>	* consistency guarantees. Maintaining this property in the face
2228	>	* of possible ongoing resizes requires a fair amount of
2229	>	* bookkeeping state that is difficult to optimize away amidst
2230	>	* volatile accesses.  Even so, traversal maintains reasonable
2231	>	* throughput.
2232	>	*
2233	>	* Normally, iteration proceeds bin-by-bin traversing lists.
2234	>	* However, if the table has been resized, then all future steps
2235	>	* must traverse both the bin at the current index as well as at
2236	>	* (index + baseSize); and so on for further resizings. To
2237	>	* paranoically cope with potential sharing by users of iterators
2238	>	* across threads, iteration terminates if a bounds checks fails
2239	>	* for a table read.
2240		*/
2241	<	private static class HashEntry<K,V> {
2242	<	private final K key;
2243	<	private V value;
2244	<	private final int hash;
2245	<	private final HashEntry<K,V> next;
2241	>	static class Traverser<K,V> {
2242	>	Node<K,V>[] tab;        // current table; updated if resized
2243	>	Node<K,V> next;         // the next entry to use
2244	>	int index;              // index of bin to use next
2245	>	int baseIndex;          // current index of initial table
2246	>	int baseLimit;          // index bound for initial table
2247	>	final int baseSize;     // initial table size
2248	>
2249	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
2250	>	this.tab = tab;
2251	>	this.baseSize = size;
2252	>	this.baseIndex = this.index = index;
2253	>	this.baseLimit = limit;
2254	>	this.next = null;
2255	>	}
2256
2257	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
2258	<	this.value = value;
2259	<	this.hash = hash;
2260	<	this.key = key;
2261	<	this.next = next;
2257	>	/**
2258	>	* Advances if possible, returning next valid node, or null if none.
2259	>	*/
2260	>	final Node<K,V> advance() {
2261	>	Node<K,V> e;
2262	>	if ((e = next) != null)
2263	>	e = e.next;
2264	>	for (;;) {
2265	>	Node<K,V>[] t; int i, n; Object ek;  // must use locals in checks
2266	>	if (e != null)
2267	>	return next = e;
2268	>	if (baseIndex >= baseLimit || (t = tab) == null ||
2269	>	(n = t.length) <= (i = index) || i < 0)
2270	>	return next = null;
2271	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
2272	>	if ((ek = e.key) instanceof TreeBin)
2273	>	e = ((TreeBin<K,V>)ek).first;
2274	>	else {
2275	>	tab = (Node<K,V>[])ek;
2276	>	e = null;
2277	>	continue;
2278	>	}
2279	>	}
2280	>	if ((index += baseSize) >= n)
2281	>	index = ++baseIndex;    // visit upper slots if present
2282	>	}
2283	>	}
2284	>	}
2285	>
2286	>	/**
2287	>	* Base of key, value, and entry Iterators. Adds fields to
2288	>	* Traverser to support iterator.remove
2289	>	*/
2290	>	static class BaseIterator<K,V> extends Traverser<K,V> {
2291	>	final ConcurrentHashMap<K,V> map;
2292	>	Node<K,V> lastReturned;
2293	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
2294	>	ConcurrentHashMap<K,V> map) {
2295	>	super(tab, size, index, limit);
2296	>	this.map = map;
2297	>	advance();
2298	>	}
2299	>
2300	>	public final boolean hasNext() { return next != null; }
2301	>	public final boolean hasMoreElements() { return next != null; }
2302	>
2303	>	public final void remove() {
2304	>	Node<K,V> p;
2305	>	if ((p = lastReturned) == null)
2306	>	throw new IllegalStateException();
2307	>	lastReturned = null;
2308	>	map.internalReplace((K)p.key, null, null);
2309	>	}
2310	>	}
2311	>
2312	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
2313	>	implements Iterator<K>, Enumeration<K> {
2314	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
2315	>	ConcurrentHashMap<K,V> map) {
2316	>	super(tab, index, size, limit, map);
2317	>	}
2318	>
2319	>	public final K next() {
2320	>	Node<K,V> p;
2321	>	if ((p = next) == null)
2322	>	throw new NoSuchElementException();
2323	>	K k = (K)p.key;
2324	>	lastReturned = p;
2325	>	advance();
2326	>	return k;
2327	>	}
2328	>
2329	>	public final K nextElement() { return next(); }
2330	>	}
2331	>
2332	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
2333	>	implements Iterator<V>, Enumeration<V> {
2334	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
2335	>	ConcurrentHashMap<K,V> map) {
2336	>	super(tab, index, size, limit, map);
2337	>	}
2338	>
2339	>	public final V next() {
2340	>	Node<K,V> p;
2341	>	if ((p = next) == null)
2342	>	throw new NoSuchElementException();
2343	>	V v = p.val;
2344	>	lastReturned = p;
2345	>	advance();
2346	>	return v;
2347	>	}
2348	>
2349	>	public final V nextElement() { return next(); }
2350	>	}
2351	>
2352	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
2353	>	implements Iterator<Map.Entry<K,V>> {
2354	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
2355	>	ConcurrentHashMap<K,V> map) {
2356	>	super(tab, index, size, limit, map);
2357	>	}
2358	>
2359	>	public final Map.Entry<K,V> next() {
2360	>	Node<K,V> p;
2361	>	if ((p = next) == null)
2362	>	throw new NoSuchElementException();
2363	>	K k = (K)p.key;
2364	>	V v = p.val;
2365	>	lastReturned = p;
2366	>	advance();
2367	>	return new MapEntry<K,V>(k, v, map);
2368	>	}
2369	>	}
2370	>
2371	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
2372	>	implements Spliterator<K> {
2373	>	long est;               // size estimate
2374	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
2375	>	long est) {
2376	>	super(tab, size, index, limit);
2377	>	this.est = est;
2378	>	}
2379	>
2380	>	public Spliterator<K> trySplit() {
2381	>	int i, f, h;
2382	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
2383	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
2384	>	f, est >>>= 1);
2385	>	}
2386	>
2387	>	public void forEachRemaining(Consumer<? super K> action) {
2388	>	if (action == null) throw new NullPointerException();
2389	>	for (Node<K,V> p; (p = advance()) != null;)
2390	>	action.accept((K)p.key);
2391	>	}
2392	>
2393	>	public boolean tryAdvance(Consumer<? super K> action) {
2394	>	if (action == null) throw new NullPointerException();
2395	>	Node<K,V> p;
2396	>	if ((p = advance()) == null)
2397	>	return false;
2398	>	action.accept((K)p.key);
2399	>	return true;
2400	>	}
2401	>
2402	>	public long estimateSize() { return est; }
2403	>
2404	>	public int characteristics() {
2405	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
2406	>	Spliterator.NONNULL;
2407	>	}
2408	>	}
2409	>
2410	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
2411	>	implements Spliterator<V> {
2412	>	long est;               // size estimate
2413	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
2414	>	long est) {
2415	>	super(tab, size, index, limit);
2416	>	this.est = est;
2417	>	}
2418	>
2419	>	public Spliterator<V> trySplit() {
2420	>	int i, f, h;
2421	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
2422	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
2423	>	f, est >>>= 1);
2424	>	}
2425	>
2426	>	public void forEachRemaining(Consumer<? super V> action) {
2427	>	if (action == null) throw new NullPointerException();
2428	>	for (Node<K,V> p; (p = advance()) != null;)
2429	>	action.accept(p.val);
2430	>	}
2431	>
2432	>	public boolean tryAdvance(Consumer<? super V> action) {
2433	>	if (action == null) throw new NullPointerException();
2434	>	Node<K,V> p;
2435	>	if ((p = advance()) == null)
2436	>	return false;
2437	>	action.accept(p.val);
2438	>	return true;
2439	>	}
2440	>
2441	>	public long estimateSize() { return est; }
2442	>
2443	>	public int characteristics() {
2444	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
2445	>	}
2446	>	}
2447	>
2448	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
2449	>	implements Spliterator<Map.Entry<K,V>> {
2450	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
2451	>	long est;               // size estimate
2452	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
2453	>	long est, ConcurrentHashMap<K,V> map) {
2454	>	super(tab, size, index, limit);
2455	>	this.map = map;
2456	>	this.est = est;
2457	>	}
2458	>
2459	>	public Spliterator<Map.Entry<K,V>> trySplit() {
2460	>	int i, f, h;
2461	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
2462	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
2463	>	f, est >>>= 1, map);
2464	>	}
2465	>
2466	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
2467	>	if (action == null) throw new NullPointerException();
2468	>	for (Node<K,V> p; (p = advance()) != null; )
2469	>	action.accept(new MapEntry<K,V>((K)p.key, p.val, map));
2470	>	}
2471	>
2472	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
2473	>	if (action == null) throw new NullPointerException();
2474	>	Node<K,V> p;
2475	>	if ((p = advance()) == null)
2476	>	return false;
2477	>	action.accept(new MapEntry<K,V>((K)p.key, p.val, map));
2478	>	return true;
2479	>	}
2480	>
2481	>	public long estimateSize() { return est; }
2482	>
2483	>	public int characteristics() {
2484	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
2485	>	Spliterator.NONNULL;
2486		}
2487		}
2488
#	Line 514 | Line 2490 | public class ConcurrentHashMap<K, V> ext
2490		/* ---------------- Public operations -------------- */
2491
2492		/**
2493	<	* Constructs a new, empty map with the specified initial
2494	<	* capacity and the specified load factor.
2493	>	* Creates a new, empty map with the default initial table size (16).
2494	>	*/
2495	>	public ConcurrentHashMap() {
2496	>	}
2497	>
2498	>	/**
2499	>	* Creates a new, empty map with an initial table size
2500	>	* accommodating the specified number of elements without the need
2501	>	* to dynamically resize.
2502	>	*
2503	>	* @param initialCapacity The implementation performs internal
2504	>	* sizing to accommodate this many elements.
2505	>	* @throws IllegalArgumentException if the initial capacity of
2506	>	* elements is negative
2507	>	*/
2508	>	public ConcurrentHashMap(int initialCapacity) {
2509	>	if (initialCapacity < 0)
2510	>	throw new IllegalArgumentException();
2511	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2512	>	MAXIMUM_CAPACITY :
2513	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2514	>	this.sizeCtl = cap;
2515	>	}
2516	>
2517	>	/**
2518	>	* Creates a new map with the same mappings as the given map.
2519	>	*
2520	>	* @param m the map
2521	>	*/
2522	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2523	>	this.sizeCtl = DEFAULT_CAPACITY;
2524	>	internalPutAll(m);
2525	>	}
2526	>
2527	>	/**
2528	>	* Creates a new, empty map with an initial table size based on
2529	>	* the given number of elements ({@code initialCapacity}) and
2530	>	* initial table density ({@code loadFactor}).
2531		*
2532		* @param initialCapacity the initial capacity. The implementation
2533	<	* performs internal sizing to accommodate this many elements.
2534	<	* @param loadFactor  the load factor threshold, used to control resizing.
2533	>	* performs internal sizing to accommodate this many elements,
2534	>	* given the specified load factor.
2535	>	* @param loadFactor the load factor (table density) for
2536	>	* establishing the initial table size
2537	>	* @throws IllegalArgumentException if the initial capacity of
2538	>	* elements is negative or the load factor is nonpositive
2539	>	*
2540	>	* @since 1.6
2541	>	*/
2542	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2543	>	this(initialCapacity, loadFactor, 1);
2544	>	}
2545	>
2546	>	/**
2547	>	* Creates a new, empty map with an initial table size based on
2548	>	* the given number of elements ({@code initialCapacity}), table
2549	>	* density ({@code loadFactor}), and number of concurrently
2550	>	* updating threads ({@code concurrencyLevel}).
2551	>	*
2552	>	* @param initialCapacity the initial capacity. The implementation
2553	>	* performs internal sizing to accommodate this many elements,
2554	>	* given the specified load factor.
2555	>	* @param loadFactor the load factor (table density) for
2556	>	* establishing the initial table size
2557		* @param concurrencyLevel the estimated number of concurrently
2558	<	* updating threads. The implementation performs internal sizing
2559	<	* to try to accommodate this many threads.
2558	>	* updating threads. The implementation may use this value as
2559	>	* a sizing hint.
2560		* @throws IllegalArgumentException if the initial capacity is
2561		* negative or the load factor or concurrencyLevel are
2562	<	* nonpositive.
2562	>	* nonpositive
2563		*/
2564		public ConcurrentHashMap(int initialCapacity,
2565		float loadFactor, int concurrencyLevel) {
2566	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2566	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2567		throw new IllegalArgumentException();
2568	+	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2569	+	initialCapacity = concurrencyLevel;   // as estimated threads
2570	+	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2571	+	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2572	+	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2573	+	this.sizeCtl = cap;
2574	+	}
2575
2576	<	if (concurrencyLevel > MAX_SEGMENTS)
2577	<	concurrencyLevel = MAX_SEGMENTS;
2578	<
2579	<	// Find power-of-two sizes best matching arguments
2580	<	int sshift = 0;
2581	<	int ssize = 1;
2582	<	while (ssize < concurrencyLevel) {
2583	<	++sshift;
2584	<	ssize <<= 1;
2585	<	}
545	<	segmentShift = 32 - sshift;
546	<	segmentMask = ssize - 1;
547	<	this.segments = new Segment[ssize];
548	<
549	<	if (initialCapacity > MAXIMUM_CAPACITY)
550	<	initialCapacity = MAXIMUM_CAPACITY;
551	<	int c = initialCapacity / ssize;
552	<	if (c * ssize < initialCapacity)
553	<	++c;
554	<	int cap = 1;
555	<	while (cap < c)
556	<	cap <<= 1;
557	<
558	<	for (int i = 0; i < this.segments.length; ++i)
559	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2576	>	/**
2577	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2578	>	* from the given type to {@code Boolean.TRUE}.
2579	>	*
2580	>	* @return the new set
2581	>	* @since 1.8
2582	>	*/
2583	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2584	>	return new KeySetView<K,Boolean>
2585	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2586		}
2587
2588		/**
2589	<	* Constructs a new, empty map with the specified initial
2590	<	* capacity,  and with default load factor and concurrencyLevel.
2589	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2590	>	* from the given type to {@code Boolean.TRUE}.
2591		*
2592		* @param initialCapacity The implementation performs internal
2593		* sizing to accommodate this many elements.
2594		* @throws IllegalArgumentException if the initial capacity of
2595	<	* elements is negative.
2595	>	* elements is negative
2596	>	* @return the new set
2597	>	* @since 1.8
2598		*/
2599	<	public ConcurrentHashMap(int initialCapacity) {
2600	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2599	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2600	>	return new KeySetView<K,Boolean>
2601	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2602		}
2603
2604		/**
2605	<	* Constructs a new, empty map with a default initial capacity,
577	<	* load factor, and concurrencyLevel.
2605	>	* {@inheritDoc}
2606		*/
2607	<	public ConcurrentHashMap() {
2608	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2607	>	public boolean isEmpty() {
2608	>	return sumCount() <= 0L; // ignore transient negative values
2609		}
2610
2611		/**
2612	<	* Constructs a new map with the same mappings as the given map.  The
585	<	* map is created with a capacity of twice the number of mappings in
586	<	* the given map or 11 (whichever is greater), and a default load factor.
2612	>	* {@inheritDoc}
2613		*/
2614	<	public <A extends K, B extends V> ConcurrentHashMap(Map<A,B> t) {
2615	<	this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
2616	<	11),
2617	<	DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2618	<	putAll(t);
2614	>	public int size() {
2615	>	long n = sumCount();
2616	>	return ((n < 0L) ? 0 :
2617	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2618	>	(int)n);
2619		}
2620
2621	<	// inherit Map javadoc
2622	<	public boolean isEmpty() {
2623	<	/*
2624	<	* We need to keep track of per-segment modCounts to avoid ABA
2625	<	* problems in which an element in one segment was added and
2626	<	* in another removed during traversal, in which case the
2627	<	* table was never actually empty at any point. Note the
2628	<	* similar use of modCounts in the size() and containsValue()
2629	<	* methods, which are the only other methods also susceptible
2630	<	* to ABA problems.
2631	<	*/
2632	<	int[] mc = new int[segments.length];
2633	<	int mcsum = 0;
608	<	for (int i = 0; i < segments.length; ++i) {
609	<	if (segments[i].count != 0)
610	<	return false;
611	<	else
612	<	mcsum += mc[i] = segments[i].modCount;
613	<	}
614	<	// If mcsum happens to be zero, then we know we got a snapshot
615	<	// before any modifications at all were made.  This is
616	<	// probably common enough to bother tracking.
617	<	if (mcsum != 0) {
618	<	for (int i = 0; i < segments.length; ++i) {
619	<	if (segments[i].count != 0 ||
620	<	mc[i] != segments[i].modCount)
621	<	return false;
622	<	}
623	<	}
624	<	return true;
2621	>	/**
2622	>	* Returns the number of mappings. This method should be used
2623	>	* instead of {@link #size} because a ConcurrentHashMap may
2624	>	* contain more mappings than can be represented as an int. The
2625	>	* value returned is an estimate; the actual count may differ if
2626	>	* there are concurrent insertions or removals.
2627	>	*
2628	>	* @return the number of mappings
2629	>	* @since 1.8
2630	>	*/
2631	>	public long mappingCount() {
2632	>	long n = sumCount();
2633	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2634		}
2635
2636	<	// inherit Map javadoc
2637	<	public int size() {
2638	<	int[] mc = new int[segments.length];
2639	<	for (;;) {
2640	<	long sum = 0;
2641	<	int mcsum = 0;
2642	<	for (int i = 0; i < segments.length; ++i) {
2643	<	sum += segments[i].count;
2644	<	mcsum += mc[i] = segments[i].modCount;
2645	<	}
2646	<	int check = 0;
2647	<	if (mcsum != 0) {
2648	<	for (int i = 0; i < segments.length; ++i) {
640	<	check += segments[i].count;
641	<	if (mc[i] != segments[i].modCount) {
642	<	check = -1; // force retry
643	<	break;
644	<	}
645	<	}
646	<	}
647	<	if (check == sum) {
648	<	if (sum > Integer.MAX_VALUE)
649	<	return Integer.MAX_VALUE;
650	<	else
651	<	return (int)sum;
652	<	}
653	<	}
2636	>	/**
2637	>	* Returns the value to which the specified key is mapped,
2638	>	* or {@code null} if this map contains no mapping for the key.
2639	>	*
2640	>	* <p>More formally, if this map contains a mapping from a key
2641	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
2642	>	* then this method returns {@code v}; otherwise it returns
2643	>	* {@code null}.  (There can be at most one such mapping.)
2644	>	*
2645	>	* @throws NullPointerException if the specified key is null
2646	>	*/
2647	>	public V get(Object key) {
2648	>	return internalGet(key);
2649		}
2650
656	–
2651		/**
2652	<	* Returns the value to which the specified key is mapped in this table.
2652	>	* Returns the value to which the specified key is mapped, or the
2653	>	* given default value if this map contains no mapping for the
2654	>	* key.
2655		*
2656	<	* @param   key   a key in the table.
2657	<	* @return  the value to which the key is mapped in this table;
2658	<	*          <tt>null</tt> if the key is not mapped to any value in
2659	<	*          this table.
2660	<	* @throws  NullPointerException  if the key is
665	<	*               <tt>null</tt>.
2656	>	* @param key the key whose associated value is to be returned
2657	>	* @param defaultValue the value to return if this map contains
2658	>	* no mapping for the given key
2659	>	* @return the mapping for the key, if present; else the default value
2660	>	* @throws NullPointerException if the specified key is null
2661		*/
2662	<	public V get(Object key) {
2663	<	int hash = hash(key); // throws NullPointerException if key null
2664	<	return segmentFor(hash).get(key, hash);
2662	>	public V getOrDefault(Object key, V defaultValue) {
2663	>	V v;
2664	>	return (v = internalGet(key)) == null ? defaultValue : v;
2665		}
2666
2667		/**
2668		* Tests if the specified object is a key in this table.
2669		*
2670	<	* @param   key   possible key.
2671	<	* @return  <tt>true</tt> if and only if the specified object
2672	<	*          is a key in this table, as determined by the
2673	<	*          <tt>equals</tt> method; <tt>false</tt> otherwise.
2674	<	* @throws  NullPointerException  if the key is
680	<	*               <tt>null</tt>.
2670	>	* @param  key possible key
2671	>	* @return {@code true} if and only if the specified object
2672	>	*         is a key in this table, as determined by the
2673	>	*         {@code equals} method; {@code false} otherwise
2674	>	* @throws NullPointerException if the specified key is null
2675		*/
2676		public boolean containsKey(Object key) {
2677	<	int hash = hash(key); // throws NullPointerException if key null
684	<	return segmentFor(hash).containsKey(key, hash);
2677	>	return internalGet(key) != null;
2678		}
2679
2680		/**
2681	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2682	<	* specified value. Note: This method requires a full internal
2683	<	* traversal of the hash table, and so is much slower than
691	<	* method <tt>containsKey</tt>.
2681	>	* Returns {@code true} if this map maps one or more keys to the
2682	>	* specified value. Note: This method may require a full traversal
2683	>	* of the map, and is much slower than method {@code containsKey}.
2684		*
2685	<	* @param value value whose presence in this map is to be tested.
2686	<	* @return <tt>true</tt> if this map maps one or more keys to the
2687	<	* specified value.
2688	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2685	>	* @param value value whose presence in this map is to be tested
2686	>	* @return {@code true} if this map maps one or more keys to the
2687	>	*         specified value
2688	>	* @throws NullPointerException if the specified value is null
2689		*/
2690		public boolean containsValue(Object value) {
2691		if (value == null)
2692		throw new NullPointerException();
2693	<
2694	<	int[] mc = new int[segments.length];
2695	<	for (;;) {
2696	<	int sum = 0;
2697	<	int mcsum = 0;
2698	<	for (int i = 0; i < segments.length; ++i) {
707	<	int c = segments[i].count;
708	<	mcsum += mc[i] = segments[i].modCount;
709	<	if (segments[i].containsValue(value))
2693	>	Node<K,V>[] t;
2694	>	if ((t = table) != null) {
2695	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
2696	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
2697	>	V v;
2698	>	if ((v = p.val) == value || value.equals(v))
2699		return true;
2700		}
712	–	boolean cleanSweep = true;
713	–	if (mcsum != 0) {
714	–	for (int i = 0; i < segments.length; ++i) {
715	–	int c = segments[i].count;
716	–	if (mc[i] != segments[i].modCount) {
717	–	cleanSweep = false;
718	–	break;
719	–	}
720	–	}
721	–	}
722	–	if (cleanSweep)
723	–	return false;
2701		}
2702	+	return false;
2703		}
2704
2705		/**
2706		* Legacy method testing if some key maps into the specified value
2707		* in this table.  This method is identical in functionality to
2708	<	* {@link #containsValue}, and  exists solely to ensure
2708	>	* {@link #containsValue(Object)}, and exists solely to ensure
2709		* full compatibility with class {@link java.util.Hashtable},
2710		* which supported this method prior to introduction of the
2711		* Java Collections framework.
2712	<
2713	<	* @param      value   a value to search for.
2714	<	* @return     <tt>true</tt> if and only if some key maps to the
2715	<	*             <tt>value</tt> argument in this table as
2716	<	*             determined by the <tt>equals</tt> method;
2717	<	*             <tt>false</tt> otherwise.
2718	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2712	>	*
2713	>	* @param  value a value to search for
2714	>	* @return {@code true} if and only if some key maps to the
2715	>	*         {@code value} argument in this table as
2716	>	*         determined by the {@code equals} method;
2717	>	*         {@code false} otherwise
2718	>	* @throws NullPointerException if the specified value is null
2719		*/
2720	<	public boolean contains(Object value) {
2720	>	@Deprecated public boolean contains(Object value) {
2721		return containsValue(value);
2722		}
2723
2724		/**
2725	<	* Maps the specified <tt>key</tt> to the specified
2726	<	* <tt>value</tt> in this table. Neither the key nor the
749	<	* value can be <tt>null</tt>. <p>
2725	>	* Maps the specified key to the specified value in this table.
2726	>	* Neither the key nor the value can be null.
2727		*
2728	<	* The value can be retrieved by calling the <tt>get</tt> method
2728	>	* <p>The value can be retrieved by calling the {@code get} method
2729		* with a key that is equal to the original key.
2730		*
2731	<	* @param      key     the table key.
2732	<	* @param      value   the value.
2733	<	* @return     the previous value of the specified key in this table,
2734	<	*             or <tt>null</tt> if it did not have one.
2735	<	* @throws  NullPointerException  if the key or value is
759	<	*               <tt>null</tt>.
2731	>	* @param key key with which the specified value is to be associated
2732	>	* @param value value to be associated with the specified key
2733	>	* @return the previous value associated with {@code key}, or
2734	>	*         {@code null} if there was no mapping for {@code key}
2735	>	* @throws NullPointerException if the specified key or value is null
2736		*/
2737		public V put(K key, V value) {
2738	<	if (value == null)
763	<	throw new NullPointerException();
764	<	int hash = hash(key);
765	<	return segmentFor(hash).put(key, hash, value, false);
2738	>	return internalPut(key, value, false);
2739		}
2740
2741		/**
2742	<	* If the specified key is not already associated
770	<	* with a value, associate it with the given value.
771	<	* This is equivalent to
772	<	* <pre>
773	<	*   if (!map.containsKey(key))
774	<	*      return map.put(key, value);
775	<	*   else
776	<	*      return map.get(key);
777	<	* </pre>
778	<	* Except that the action is performed atomically.
779	<	* @param key key with which the specified value is to be associated.
780	<	* @param value value to be associated with the specified key.
781	<	* @return previous value associated with specified key, or <tt>null</tt>
782	<	*         if there was no mapping for key.  A <tt>null</tt> return can
783	<	*         also indicate that the map previously associated <tt>null</tt>
784	<	*         with the specified key, if the implementation supports
785	<	*         <tt>null</tt> values.
786	<	*
787	<	* @throws UnsupportedOperationException if the <tt>put</tt> operation is
788	<	*            not supported by this map.
789	<	* @throws ClassCastException if the class of the specified key or value
790	<	*            prevents it from being stored in this map.
791	<	* @throws NullPointerException if the specified key or value is
792	<	*            <tt>null</tt>.
2742	>	* {@inheritDoc}
2743		*
2744	<	**/
2744	>	* @return the previous value associated with the specified key,
2745	>	*         or {@code null} if there was no mapping for the key
2746	>	* @throws NullPointerException if the specified key or value is null
2747	>	*/
2748		public V putIfAbsent(K key, V value) {
2749	<	if (value == null)
797	<	throw new NullPointerException();
798	<	int hash = hash(key);
799	<	return segmentFor(hash).put(key, hash, value, true);
2749	>	return internalPut(key, value, true);
2750		}
2751
802	–
2752		/**
2753		* Copies all of the mappings from the specified map to this one.
805	–	*
2754		* These mappings replace any mappings that this map had for any of the
2755	<	* keys currently in the specified Map.
2755	>	* keys currently in the specified map.
2756		*
2757	<	* @param t Mappings to be stored in this map.
2757	>	* @param m mappings to be stored in this map
2758		*/
2759	<	public void putAll(Map<? extends K, ? extends V> t) {
2760	<	for (Iterator<Map.Entry<? extends K, ? extends V>> it = (Iterator<Map.Entry<? extends K, ? extends V>>) t.entrySet().iterator(); it.hasNext(); ) {
813	<	Entry<? extends K, ? extends V> e = it.next();
814	<	put(e.getKey(), e.getValue());
815	<	}
2759	>	public void putAll(Map<? extends K, ? extends V> m) {
2760	>	internalPutAll(m);
2761		}
2762
2763		/**
2764	<	* Removes the key (and its corresponding value) from this
2765	<	* table. This method does nothing if the key is not in the table.
2764	>	* If the specified key is not already associated with a value,
2765	>	* attempts to compute its value using the given mapping function
2766	>	* and enters it into this map unless {@code null}.  The entire
2767	>	* method invocation is performed atomically, so the function is
2768	>	* applied at most once per key.  Some attempted update operations
2769	>	* on this map by other threads may be blocked while computation
2770	>	* is in progress, so the computation should be short and simple,
2771	>	* and must not attempt to update any other mappings of this map.
2772		*
2773	<	* @param   key   the key that needs to be removed.
2774	<	* @return  the value to which the key had been mapped in this table,
2775	<	*          or <tt>null</tt> if the key did not have a mapping.
2776	<	* @throws  NullPointerException  if the key is
2777	<	*               <tt>null</tt>.
2773	>	* @param key key with which the specified value is to be associated
2774	>	* @param mappingFunction the function to compute a value
2775	>	* @return the current (existing or computed) value associated with
2776	>	*         the specified key, or null if the computed value is null
2777	>	* @throws NullPointerException if the specified key or mappingFunction
2778	>	*         is null
2779	>	* @throws IllegalStateException if the computation detectably
2780	>	*         attempts a recursive update to this map that would
2781	>	*         otherwise never complete
2782	>	* @throws RuntimeException or Error if the mappingFunction does so,
2783	>	*         in which case the mapping is left unestablished
2784		*/
2785	<	public V remove(Object key) {
2786	<	int hash = hash(key);
830	<	return segmentFor(hash).remove(key, hash, null);
2785	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
2786	>	return internalComputeIfAbsent(key, mappingFunction);
2787		}
2788
2789		/**
2790	<	* Remove entry for key only if currently mapped to given value.
2791	<	* Acts as
2792	<	* <pre>
2793	<	*  if (map.get(key).equals(value)) {
2794	<	*     map.remove(key);
2795	<	*     return true;
2796	<	* } else return false;
2797	<	* </pre>
2798	<	* except that the action is performed atomically.
2799	<	* @param key key with which the specified value is associated.
2800	<	* @param value value associated with the specified key.
2801	<	* @return true if the value was removed
2802	<	* @throws NullPointerException if the specified key is
2803	<	*            <tt>null</tt>.
2790	>	* If the value for the specified key is present, attempts to
2791	>	* compute a new mapping given the key and its current mapped
2792	>	* value.  The entire method invocation is performed atomically.
2793	>	* Some attempted update operations on this map by other threads
2794	>	* may be blocked while computation is in progress, so the
2795	>	* computation should be short and simple, and must not attempt to
2796	>	* update any other mappings of this map.
2797	>	*
2798	>	* @param key key with which a value may be associated
2799	>	* @param remappingFunction the function to compute a value
2800	>	* @return the new value associated with the specified key, or null if none
2801	>	* @throws NullPointerException if the specified key or remappingFunction
2802	>	*         is null
2803	>	* @throws IllegalStateException if the computation detectably
2804	>	*         attempts a recursive update to this map that would
2805	>	*         otherwise never complete
2806	>	* @throws RuntimeException or Error if the remappingFunction does so,
2807	>	*         in which case the mapping is unchanged
2808		*/
2809	<	public boolean remove(Object key, Object value) {
2810	<	int hash = hash(key);
851	<	return segmentFor(hash).remove(key, hash, value) != null;
2809	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2810	>	return internalCompute(key, true, remappingFunction);
2811		}
2812
854	–
2813		/**
2814	<	* Replace entry for key only if currently mapped to given value.
2815	<	* Acts as
2816	<	* <pre>
2817	<	*  if (map.get(key).equals(oldValue)) {
2818	<	*     map.put(key, newValue);
2819	<	*     return true;
2820	<	* } else return false;
2821	<	* </pre>
2822	<	* except that the action is performed atomically.
2823	<	* @param key key with which the specified value is associated.
2824	<	* @param oldValue value expected to be associated with the specified key.
2825	<	* @param newValue value to be associated with the specified key.
2826	<	* @return true if the value was replaced
2827	<	* @throws NullPointerException if the specified key or values are
2828	<	* <tt>null</tt>.
2814	>	* Attempts to compute a mapping for the specified key and its
2815	>	* current mapped value (or {@code null} if there is no current
2816	>	* mapping). The entire method invocation is performed atomically.
2817	>	* Some attempted update operations on this map by other threads
2818	>	* may be blocked while computation is in progress, so the
2819	>	* computation should be short and simple, and must not attempt to
2820	>	* update any other mappings of this Map.
2821	>	*
2822	>	* @param key key with which the specified value is to be associated
2823	>	* @param remappingFunction the function to compute a value
2824	>	* @return the new value associated with the specified key, or null if none
2825	>	* @throws NullPointerException if the specified key or remappingFunction
2826	>	*         is null
2827	>	* @throws IllegalStateException if the computation detectably
2828	>	*         attempts a recursive update to this map that would
2829	>	*         otherwise never complete
2830	>	* @throws RuntimeException or Error if the remappingFunction does so,
2831	>	*         in which case the mapping is unchanged
2832		*/
2833	<	public boolean replace(K key, V oldValue, V newValue) {
2834	<	if (oldValue == null || newValue == null)
874	<	throw new NullPointerException();
875	<	int hash = hash(key);
876	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
2833	>	public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2834	>	return internalCompute(key, false, remappingFunction);
2835		}
2836
2837		/**
2838	<	* Replace entry for key only if currently mapped to some value.
2839	<	* Acts as
2840	<	* <pre>
2841	<	*  if ((map.containsKey(key)) {
2842	<	*     return map.put(key, value);
2843	<	* } else return null;
2844	<	* </pre>
2845	<	* except that the action is performed atomically.
2846	<	* @param key key with which the specified value is associated.
2847	<	* @param value value to be associated with the specified key.
2848	<	* @return previous value associated with specified key, or <tt>null</tt>
2849	<	*         if there was no mapping for key.
2850	<	* @throws NullPointerException if the specified key or value is
2851	<	*            <tt>null</tt>.
2838	>	* If the specified key is not already associated with a
2839	>	* (non-null) value, associates it with the given value.
2840	>	* Otherwise, replaces the value with the results of the given
2841	>	* remapping function, or removes if {@code null}. The entire
2842	>	* method invocation is performed atomically.  Some attempted
2843	>	* update operations on this map by other threads may be blocked
2844	>	* while computation is in progress, so the computation should be
2845	>	* short and simple, and must not attempt to update any other
2846	>	* mappings of this Map.
2847	>	*
2848	>	* @param key key with which the specified value is to be associated
2849	>	* @param value the value to use if absent
2850	>	* @param remappingFunction the function to recompute a value if present
2851	>	* @return the new value associated with the specified key, or null if none
2852	>	* @throws NullPointerException if the specified key or the
2853	>	*         remappingFunction is null
2854	>	* @throws RuntimeException or Error if the remappingFunction does so,
2855	>	*         in which case the mapping is unchanged
2856		*/
2857	<	public V replace(K key, V value) {
2858	<	if (value == null)
897	<	throw new NullPointerException();
898	<	int hash = hash(key);
899	<	return segmentFor(hash).replace(key, hash, value);
2857	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2858	>	return internalMerge(key, value, remappingFunction);
2859		}
2860
2861	+	/**
2862	+	* Removes the key (and its corresponding value) from this map.
2863	+	* This method does nothing if the key is not in the map.
2864	+	*
2865	+	* @param  key the key that needs to be removed
2866	+	* @return the previous value associated with {@code key}, or
2867	+	*         {@code null} if there was no mapping for {@code key}
2868	+	* @throws NullPointerException if the specified key is null
2869	+	*/
2870	+	public V remove(Object key) {
2871	+	return internalReplace(key, null, null);
2872	+	}
2873
2874		/**
2875	<	* Removes all mappings from this map.
2875	>	* {@inheritDoc}
2876	>	*
2877	>	* @throws NullPointerException if the specified key is null
2878		*/
2879	<	public void clear() {
2880	<	for (int i = 0; i < segments.length; ++i)
2881	<	segments[i].clear();
2879	>	public boolean remove(Object key, Object value) {
2880	>	if (key == null)
2881	>	throw new NullPointerException();
2882	>	return value != null && internalReplace(key, null, value) != null;
2883		}
2884
2885	+	/**
2886	+	* {@inheritDoc}
2887	+	*
2888	+	* @throws NullPointerException if any of the arguments are null
2889	+	*/
2890	+	public boolean replace(K key, V oldValue, V newValue) {
2891	+	if (key == null || oldValue == null || newValue == null)
2892	+	throw new NullPointerException();
2893	+	return internalReplace(key, newValue, oldValue) != null;
2894	+	}
2895
2896		/**
2897	<	* Returns a shallow copy of this
914	<	* <tt>ConcurrentHashMap</tt> instance: the keys and
915	<	* values themselves are not cloned.
2897	>	* {@inheritDoc}
2898		*
2899	<	* @return a shallow copy of this map.
2899	>	* @return the previous value associated with the specified key,
2900	>	*         or {@code null} if there was no mapping for the key
2901	>	* @throws NullPointerException if the specified key or value is null
2902		*/
2903	<	public Object clone() {
2904	<	// We cannot call super.clone, since it would share final
2905	<	// segments array, and there's no way to reassign finals.
2903	>	public V replace(K key, V value) {
2904	>	if (key == null || value == null)
2905	>	throw new NullPointerException();
2906	>	return internalReplace(key, value, null);
2907	>	}
2908
2909	<	float lf = segments[0].loadFactor;
2910	<	int segs = segments.length;
2911	<	int cap = (int)(size() / lf);
2912	<	if (cap < segs) cap = segs;
2913	<	ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
928	<	t.putAll(this);
929	<	return t;
2909	>	/**
2910	>	* Removes all of the mappings from this map.
2911	>	*/
2912	>	public void clear() {
2913	>	internalClear();
2914		}
2915
2916		/**
2917	<	* Returns a set view of the keys contained in this map.  The set is
2918	<	* backed by the map, so changes to the map are reflected in the set, and
2919	<	* vice-versa.  The set supports element removal, which removes the
2920	<	* corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
2921	<	* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
2922	<	* <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
2923	<	* <tt>addAll</tt> operations.
2924	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
2925	<	* will never throw {@link java.util.ConcurrentModificationException},
2917	>	* Returns a {@link Set} view of the keys contained in this map.
2918	>	* The set is backed by the map, so changes to the map are
2919	>	* reflected in the set, and vice-versa. The set supports element
2920	>	* removal, which removes the corresponding mapping from this map,
2921	>	* via the {@code Iterator.remove}, {@code Set.remove},
2922	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2923	>	* operations.  It does not support the {@code add} or
2924	>	* {@code addAll} operations.
2925	>	*
2926	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2927	>	* that will never throw {@link ConcurrentModificationException},
2928		* and guarantees to traverse elements as they existed upon
2929		* construction of the iterator, and may (but is not guaranteed to)
2930		* reflect any modifications subsequent to construction.
2931		*
2932	<	* @return a set view of the keys contained in this map.
2932	>	* @return the set view
2933		*/
2934	<	public Set<K> keySet() {
2935	<	Set<K> ks = keySet;
2936	<	return (ks != null) ? ks : (keySet = new KeySet());
2934	>	public KeySetView<K,V> keySet() {
2935	>	KeySetView<K,V> ks = keySet;
2936	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2937		}
2938
2939	+	/**
2940	+	* Returns a {@link Set} view of the keys in this map, using the
2941	+	* given common mapped value for any additions (i.e., {@link
2942	+	* Collection#add} and {@link Collection#addAll(Collection)}).
2943	+	* This is of course only appropriate if it is acceptable to use
2944	+	* the same value for all additions from this view.
2945	+	*
2946	+	* @param mappedValue the mapped value to use for any additions
2947	+	* @return the set view
2948	+	* @throws NullPointerException if the mappedValue is null
2949	+	*/
2950	+	public KeySetView<K,V> keySet(V mappedValue) {
2951	+	if (mappedValue == null)
2952	+	throw new NullPointerException();
2953	+	return new KeySetView<K,V>(this, mappedValue);
2954	+	}
2955
2956		/**
2957	<	* Returns a collection view of the values contained in this map.  The
2958	<	* collection is backed by the map, so changes to the map are reflected in
2959	<	* the collection, and vice-versa.  The collection supports element
2960	<	* removal, which removes the corresponding mapping from this map, via the
2961	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
2962	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
2963	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
2964	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
2965	<	* will never throw {@link java.util.ConcurrentModificationException},
2957	>	* Returns a {@link Collection} view of the values contained in this map.
2958	>	* The collection is backed by the map, so changes to the map are
2959	>	* reflected in the collection, and vice-versa.  The collection
2960	>	* supports element removal, which removes the corresponding
2961	>	* mapping from this map, via the {@code Iterator.remove},
2962	>	* {@code Collection.remove}, {@code removeAll},
2963	>	* {@code retainAll}, and {@code clear} operations.  It does not
2964	>	* support the {@code add} or {@code addAll} operations.
2965	>	*
2966	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2967	>	* that will never throw {@link ConcurrentModificationException},
2968		* and guarantees to traverse elements as they existed upon
2969		* construction of the iterator, and may (but is not guaranteed to)
2970		* reflect any modifications subsequent to construction.
2971		*
2972	<	* @return a collection view of the values contained in this map.
2972	>	* @return the collection view
2973		*/
2974		public Collection<V> values() {
2975	<	Collection<V> vs = values;
2976	<	return (vs != null) ? vs : (values = new Values());
2975	>	ValuesView<K,V> vs = values;
2976	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2977		}
2978
975	–
2979		/**
2980	<	* Returns a collection view of the mappings contained in this map.  Each
2981	<	* element in the returned collection is a <tt>Map.Entry</tt>.  The
2982	<	* collection is backed by the map, so changes to the map are reflected in
2983	<	* the collection, and vice-versa.  The collection supports element
2984	<	* removal, which removes the corresponding mapping from the map, via the
2985	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
2986	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
2987	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
2988	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
2989	<	* will never throw {@link java.util.ConcurrentModificationException},
2980	>	* Returns a {@link Set} view of the mappings contained in this map.
2981	>	* The set is backed by the map, so changes to the map are
2982	>	* reflected in the set, and vice-versa.  The set supports element
2983	>	* removal, which removes the corresponding mapping from the map,
2984	>	* via the {@code Iterator.remove}, {@code Set.remove},
2985	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2986	>	* operations.
2987	>	*
2988	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2989	>	* that will never throw {@link ConcurrentModificationException},
2990		* and guarantees to traverse elements as they existed upon
2991		* construction of the iterator, and may (but is not guaranteed to)
2992		* reflect any modifications subsequent to construction.
2993		*
2994	<	* @return a collection view of the mappings contained in this map.
2994	>	* @return the set view
2995		*/
2996		public Set<Map.Entry<K,V>> entrySet() {
2997	<	Set<Map.Entry<K,V>> es = entrySet;
2998	<	return (es != null) ? es : (entrySet = (Set<Map.Entry<K,V>>) (Set) new EntrySet());
2997	>	EntrySetView<K,V> es = entrySet;
2998	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2999		}
3000
998	–
3001		/**
3002		* Returns an enumeration of the keys in this table.
3003		*
3004	<	* @return  an enumeration of the keys in this table.
3005	<	* @see     #keySet
3004	>	* @return an enumeration of the keys in this table
3005	>	* @see #keySet()
3006		*/
3007		public Enumeration<K> keys() {
3008	<	return new KeyIterator();
3008	>	Node<K,V>[] t;
3009	>	int f = (t = table) == null ? 0 : t.length;
3010	>	return new KeyIterator<K,V>(t, f, 0, f, this);
3011		}
3012
3013		/**
3014		* Returns an enumeration of the values in this table.
1011	–	* Use the Enumeration methods on the returned object to fetch the elements
1012	–	* sequentially.
3015		*
3016	<	* @return  an enumeration of the values in this table.
3017	<	* @see     #values
3016	>	* @return an enumeration of the values in this table
3017	>	* @see #values()
3018		*/
3019		public Enumeration<V> elements() {
3020	<	return new ValueIterator();
3020	>	Node<K,V>[] t;
3021	>	int f = (t = table) == null ? 0 : t.length;
3022	>	return new ValueIterator<K,V>(t, f, 0, f, this);
3023		}
3024
3025	<	/* ---------------- Iterator Support -------------- */
3025	>	/**
3026	>	* Returns the hash code value for this {@link Map}, i.e.,
3027	>	* the sum of, for each key-value pair in the map,
3028	>	* {@code key.hashCode() ^ value.hashCode()}.
3029	>	*
3030	>	* @return the hash code value for this map
3031	>	*/
3032	>	public int hashCode() {
3033	>	int h = 0;
3034	>	Node<K,V>[] t;
3035	>	if ((t = table) != null) {
3036	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
3037	>	for (Node<K,V> p; (p = it.advance()) != null; )
3038	>	h += p.key.hashCode() ^ p.val.hashCode();
3039	>	}
3040	>	return h;
3041	>	}
3042
3043	<	private abstract class HashIterator {
3044	<	private int nextSegmentIndex;
3045	<	private int nextTableIndex;
3046	<	private HashEntry[] currentTable;
3047	<	private HashEntry<K, V> nextEntry;
3048	<	HashEntry<K, V> lastReturned;
3043	>	/**
3044	>	* Returns a string representation of this map.  The string
3045	>	* representation consists of a list of key-value mappings (in no
3046	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
3047	>	* mappings are separated by the characters {@code ", "} (comma
3048	>	* and space).  Each key-value mapping is rendered as the key
3049	>	* followed by an equals sign ("{@code =}") followed by the
3050	>	* associated value.
3051	>	*
3052	>	* @return a string representation of this map
3053	>	*/
3054	>	public String toString() {
3055	>	Node<K,V>[] t;
3056	>	int f = (t = table) == null ? 0 : t.length;
3057	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
3058	>	StringBuilder sb = new StringBuilder();
3059	>	sb.append('{');
3060	>	Node<K,V> p;
3061	>	if ((p = it.advance()) != null) {
3062	>	for (;;) {
3063	>	K k = (K)p.key;
3064	>	V v = p.val;
3065	>	sb.append(k == this ? "(this Map)" : k);
3066	>	sb.append('=');
3067	>	sb.append(v == this ? "(this Map)" : v);
3068	>	if ((p = it.advance()) == null)
3069	>	break;
3070	>	sb.append(',').append(' ');
3071	>	}
3072	>	}
3073	>	return sb.append('}').toString();
3074	>	}
3075
3076	<	private HashIterator() {
3077	<	nextSegmentIndex = segments.length - 1;
3078	<	nextTableIndex = -1;
3079	<	advance();
3076	>	/**
3077	>	* Compares the specified object with this map for equality.
3078	>	* Returns {@code true} if the given object is a map with the same
3079	>	* mappings as this map.  This operation may return misleading
3080	>	* results if either map is concurrently modified during execution
3081	>	* of this method.
3082	>	*
3083	>	* @param o object to be compared for equality with this map
3084	>	* @return {@code true} if the specified object is equal to this map
3085	>	*/
3086	>	public boolean equals(Object o) {
3087	>	if (o != this) {
3088	>	if (!(o instanceof Map))
3089	>	return false;
3090	>	Map<?,?> m = (Map<?,?>) o;
3091	>	Node<K,V>[] t;
3092	>	int f = (t = table) == null ? 0 : t.length;
3093	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
3094	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
3095	>	V val = p.val;
3096	>	Object v = m.get(p.key);
3097	>	if (v == null || (v != val && !v.equals(val)))
3098	>	return false;
3099	>	}
3100	>	for (Map.Entry<?,?> e : m.entrySet()) {
3101	>	Object mk, mv, v;
3102	>	if ((mk = e.getKey()) == null ||
3103	>	(mv = e.getValue()) == null ||
3104	>	(v = internalGet(mk)) == null ||
3105	>	(mv != v && !mv.equals(v)))
3106	>	return false;
3107	>	}
3108		}
3109	+	return true;
3110	+	}
3111
3112	<	public boolean hasMoreElements() { return hasNext(); }
3112	>	/* ---------------- Serialization Support -------------- */
3113
3114	<	private void advance() {
3115	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
3116	<	return;
3114	>	/**
3115	>	* Stripped-down version of helper class used in previous version,
3116	>	* declared for the sake of serialization compatibility
3117	>	*/
3118	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
3119	>	private static final long serialVersionUID = 2249069246763182397L;
3120	>	final float loadFactor;
3121	>	Segment(float lf) { this.loadFactor = lf; }
3122	>	}
3123
3124	<	while (nextTableIndex >= 0) {
3125	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
3126	<	return;
3124	>	/**
3125	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3126	>	* stream (i.e., serializes it).
3127	>	* @param s the stream
3128	>	* @serialData
3129	>	* the key (Object) and value (Object)
3130	>	* for each key-value mapping, followed by a null pair.
3131	>	* The key-value mappings are emitted in no particular order.
3132	>	*/
3133	>	private void writeObject(java.io.ObjectOutputStream s)
3134	>	throws java.io.IOException {
3135	>	// For serialization compatibility
3136	>	// Emulate segment calculation from previous version of this class
3137	>	int sshift = 0;
3138	>	int ssize = 1;
3139	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
3140	>	++sshift;
3141	>	ssize <<= 1;
3142	>	}
3143	>	int segmentShift = 32 - sshift;
3144	>	int segmentMask = ssize - 1;
3145	>	Segment<K,V>[] segments = (Segment<K,V>[])
3146	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3147	>	for (int i = 0; i < segments.length; ++i)
3148	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3149	>	s.putFields().put("segments", segments);
3150	>	s.putFields().put("segmentShift", segmentShift);
3151	>	s.putFields().put("segmentMask", segmentMask);
3152	>	s.writeFields();
3153	>
3154	>	Node<K,V>[] t;
3155	>	if ((t = table) != null) {
3156	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
3157	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
3158	>	s.writeObject(p.key);
3159	>	s.writeObject(p.val);
3160		}
3161	+	}
3162	+	s.writeObject(null);
3163	+	s.writeObject(null);
3164	+	segments = null; // throw away
3165	+	}
3166	+
3167	+	/**
3168	+	* Reconstitutes the instance from a stream (that is, deserializes it).
3169	+	* @param s the stream
3170	+	*/
3171	+	private void readObject(java.io.ObjectInputStream s)
3172	+	throws java.io.IOException, ClassNotFoundException {
3173	+	s.defaultReadObject();
3174
3175	<	while (nextSegmentIndex >= 0) {
3176	<	Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
3177	<	if (seg.count != 0) {
3178	<	currentTable = seg.table;
3179	<	for (int j = currentTable.length - 1; j >= 0; --j) {
3180	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
3181	<	nextTableIndex = j - 1;
3182	<	return;
3175	>	// Create all nodes, then place in table once size is known
3176	>	long size = 0L;
3177	>	Node<K,V> p = null;
3178	>	for (;;) {
3179	>	K k = (K) s.readObject();
3180	>	V v = (V) s.readObject();
3181	>	if (k != null && v != null) {
3182	>	int h = spread(k.hashCode());
3183	>	p = new Node<K,V>(h, k, v, p);
3184	>	++size;
3185	>	}
3186	>	else
3187	>	break;
3188	>	}
3189	>	if (p != null) {
3190	>	boolean init = false;
3191	>	int n;
3192	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3193	>	n = MAXIMUM_CAPACITY;
3194	>	else {
3195	>	int sz = (int)size;
3196	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3197	>	}
3198	>	int sc = sizeCtl;
3199	>	boolean collide = false;
3200	>	if (n > sc &&
3201	>	U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
3202	>	try {
3203	>	if (table == null) {
3204	>	init = true;
3205	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
3206	>	int mask = n - 1;
3207	>	while (p != null) {
3208	>	int j = p.hash & mask;
3209	>	Node<K,V> next = p.next;
3210	>	Node<K,V> q = p.next = tabAt(tab, j);
3211	>	setTabAt(tab, j, p);
3212	>	if (!collide && q != null && q.hash == p.hash)
3213	>	collide = true;
3214	>	p = next;
3215	>	}
3216	>	table = tab;
3217	>	addCount(size, -1);
3218	>	sc = n - (n >>> 2);
3219	>	}
3220	>	} finally {
3221	>	sizeCtl = sc;
3222	>	}
3223	>	if (collide) { // rescan and convert to TreeBins
3224	>	Node<K,V>[] tab = table;
3225	>	for (int i = 0; i < tab.length; ++i) {
3226	>	int c = 0;
3227	>	for (Node<K,V> e = tabAt(tab, i); e != null; e = e.next) {
3228	>	if (++c > TREE_THRESHOLD &&
3229	>	(e.key instanceof Comparable)) {
3230	>	replaceWithTreeBin(tab, i, e.key);
3231	>	break;
3232	>	}
3233		}
3234		}
3235		}
3236		}
3237	+	if (!init) { // Can only happen if unsafely published.
3238	+	while (p != null) {
3239	+	internalPut((K)p.key, p.val, false);
3240	+	p = p.next;
3241	+	}
3242	+	}
3243		}
3244	+	}
3245
3246	<	public boolean hasNext() { return nextEntry != null; }
3246	>	// -------------------------------------------------------
3247
3248	<	HashEntry<K,V> nextEntry() {
3249	<	if (nextEntry == null)
3250	<	throw new NoSuchElementException();
3251	<	lastReturned = nextEntry;
3252	<	advance();
3253	<	return lastReturned;
3248	>	// Overrides of other default Map methods
3249	>
3250	>	public void forEach(BiConsumer<? super K, ? super V> action) {
3251	>	if (action == null) throw new NullPointerException();
3252	>	Node<K,V>[] t;
3253	>	if ((t = table) != null) {
3254	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
3255	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
3256	>	action.accept((K)p.key, p.val);
3257	>	}
3258		}
3259	+	}
3260
3261	<	public void remove() {
3262	<	if (lastReturned == null)
3263	<	throw new IllegalStateException();
3264	<	ConcurrentHashMap.this.remove(lastReturned.key);
3265	<	lastReturned = null;
3261	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
3262	>	if (function == null) throw new NullPointerException();
3263	>	Node<K,V>[] t;
3264	>	if ((t = table) != null) {
3265	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
3266	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
3267	>	K k = (K)p.key;
3268	>	internalPut(k, function.apply(k, p.val), false);
3269	>	}
3270		}
3271		}
3272
3273	<	private class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
3274	<	public K next() { return super.nextEntry().key; }
3275	<	public K nextElement() { return super.nextEntry().key; }
3273	>	// -------------------------------------------------------
3274	>
3275	>	// Parallel bulk operations
3276	>
3277	>	/**
3278	>	* Computes initial batch value for bulk tasks. The returned value
3279	>	* is approximately exp2 of the number of times (minus one) to
3280	>	* split task by two before executing leaf action. This value is
3281	>	* faster to compute and more convenient to use as a guide to
3282	>	* splitting than is the depth, since it is used while dividing by
3283	>	* two anyway.
3284	>	*/
3285	>	final int batchFor(long b) {
3286	>	long n;
3287	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3288	>	return 0;
3289	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3290	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3291	>	}
3292	>
3293	>	/**
3294	>	* Performs the given action for each (key, value).
3295	>	*
3296	>	* @param parallelismThreshold the (estimated) number of elements
3297	>	* needed for this operation to be executed in parallel
3298	>	* @param action the action
3299	>	* @since 1.8
3300	>	*/
3301	>	public void forEach(long parallelismThreshold,
3302	>	BiConsumer<? super K,? super V> action) {
3303	>	if (action == null) throw new NullPointerException();
3304	>	new ForEachMappingTask<K,V>
3305	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3306	>	action).invoke();
3307	>	}
3308	>
3309	>	/**
3310	>	* Performs the given action for each non-null transformation
3311	>	* of each (key, value).
3312	>	*
3313	>	* @param parallelismThreshold the (estimated) number of elements
3314	>	* needed for this operation to be executed in parallel
3315	>	* @param transformer a function returning the transformation
3316	>	* for an element, or null if there is no transformation (in
3317	>	* which case the action is not applied)
3318	>	* @param action the action
3319	>	* @since 1.8
3320	>	*/
3321	>	public <U> void forEach(long parallelismThreshold,
3322	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3323	>	Consumer<? super U> action) {
3324	>	if (transformer == null || action == null)
3325	>	throw new NullPointerException();
3326	>	new ForEachTransformedMappingTask<K,V,U>
3327	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3328	>	transformer, action).invoke();
3329	>	}
3330	>
3331	>	/**
3332	>	* Returns a non-null result from applying the given search
3333	>	* function on each (key, value), or null if none.  Upon
3334	>	* success, further element processing is suppressed and the
3335	>	* results of any other parallel invocations of the search
3336	>	* function are ignored.
3337	>	*
3338	>	* @param parallelismThreshold the (estimated) number of elements
3339	>	* needed for this operation to be executed in parallel
3340	>	* @param searchFunction a function returning a non-null
3341	>	* result on success, else null
3342	>	* @return a non-null result from applying the given search
3343	>	* function on each (key, value), or null if none
3344	>	* @since 1.8
3345	>	*/
3346	>	public <U> U search(long parallelismThreshold,
3347	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3348	>	if (searchFunction == null) throw new NullPointerException();
3349	>	return new SearchMappingsTask<K,V,U>
3350	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3351	>	searchFunction, new AtomicReference<U>()).invoke();
3352	>	}
3353	>
3354	>	/**
3355	>	* Returns the result of accumulating the given transformation
3356	>	* of all (key, value) pairs using the given reducer to
3357	>	* combine values, or null if none.
3358	>	*
3359	>	* @param parallelismThreshold the (estimated) number of elements
3360	>	* needed for this operation to be executed in parallel
3361	>	* @param transformer a function returning the transformation
3362	>	* for an element, or null if there is no transformation (in
3363	>	* which case it is not combined)
3364	>	* @param reducer a commutative associative combining function
3365	>	* @return the result of accumulating the given transformation
3366	>	* of all (key, value) pairs
3367	>	* @since 1.8
3368	>	*/
3369	>	public <U> U reduce(long parallelismThreshold,
3370	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3371	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3372	>	if (transformer == null || reducer == null)
3373	>	throw new NullPointerException();
3374	>	return new MapReduceMappingsTask<K,V,U>
3375	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3376	>	null, transformer, reducer).invoke();
3377	>	}
3378	>
3379	>	/**
3380	>	* Returns the result of accumulating the given transformation
3381	>	* of all (key, value) pairs using the given reducer to
3382	>	* combine values, and the given basis as an identity value.
3383	>	*
3384	>	* @param parallelismThreshold the (estimated) number of elements
3385	>	* needed for this operation to be executed in parallel
3386	>	* @param transformer a function returning the transformation
3387	>	* for an element
3388	>	* @param basis the identity (initial default value) for the reduction
3389	>	* @param reducer a commutative associative combining function
3390	>	* @return the result of accumulating the given transformation
3391	>	* of all (key, value) pairs
3392	>	* @since 1.8
3393	>	*/
3394	>	public double reduceToDoubleIn(long parallelismThreshold,
3395	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3396	>	double basis,
3397	>	DoubleBinaryOperator reducer) {
3398	>	if (transformer == null || reducer == null)
3399	>	throw new NullPointerException();
3400	>	return new MapReduceMappingsToDoubleTask<K,V>
3401	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3402	>	null, transformer, basis, reducer).invoke();
3403	>	}
3404	>
3405	>	/**
3406	>	* Returns the result of accumulating the given transformation
3407	>	* of all (key, value) pairs using the given reducer to
3408	>	* combine values, and the given basis as an identity value.
3409	>	*
3410	>	* @param parallelismThreshold the (estimated) number of elements
3411	>	* needed for this operation to be executed in parallel
3412	>	* @param transformer a function returning the transformation
3413	>	* for an element
3414	>	* @param basis the identity (initial default value) for the reduction
3415	>	* @param reducer a commutative associative combining function
3416	>	* @return the result of accumulating the given transformation
3417	>	* of all (key, value) pairs
3418	>	* @since 1.8
3419	>	*/
3420	>	public long reduceToLong(long parallelismThreshold,
3421	>	ToLongBiFunction<? super K, ? super V> transformer,
3422	>	long basis,
3423	>	LongBinaryOperator reducer) {
3424	>	if (transformer == null || reducer == null)
3425	>	throw new NullPointerException();
3426	>	return new MapReduceMappingsToLongTask<K,V>
3427	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3428	>	null, transformer, basis, reducer).invoke();
3429	>	}
3430	>
3431	>	/**
3432	>	* Returns the result of accumulating the given transformation
3433	>	* of all (key, value) pairs using the given reducer to
3434	>	* combine values, and the given basis as an identity value.
3435	>	*
3436	>	* @param parallelismThreshold the (estimated) number of elements
3437	>	* needed for this operation to be executed in parallel
3438	>	* @param transformer a function returning the transformation
3439	>	* for an element
3440	>	* @param basis the identity (initial default value) for the reduction
3441	>	* @param reducer a commutative associative combining function
3442	>	* @return the result of accumulating the given transformation
3443	>	* of all (key, value) pairs
3444	>	* @since 1.8
3445	>	*/
3446	>	public int reduceToInt(long parallelismThreshold,
3447	>	ToIntBiFunction<? super K, ? super V> transformer,
3448	>	int basis,
3449	>	IntBinaryOperator reducer) {
3450	>	if (transformer == null || reducer == null)
3451	>	throw new NullPointerException();
3452	>	return new MapReduceMappingsToIntTask<K,V>
3453	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3454	>	null, transformer, basis, reducer).invoke();
3455	>	}
3456	>
3457	>	/**
3458	>	* Performs the given action for each key.
3459	>	*
3460	>	* @param parallelismThreshold the (estimated) number of elements
3461	>	* needed for this operation to be executed in parallel
3462	>	* @param action the action
3463	>	* @since 1.8
3464	>	*/
3465	>	public void forEachKey(long parallelismThreshold,
3466	>	Consumer<? super K> action) {
3467	>	if (action == null) throw new NullPointerException();
3468	>	new ForEachKeyTask<K,V>
3469	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3470	>	action).invoke();
3471		}
3472
3473	<	private class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
3474	<	public V next() { return super.nextEntry().value; }
3475	<	public V nextElement() { return super.nextEntry().value; }
3473	>	/**
3474	>	* Performs the given action for each non-null transformation
3475	>	* of each key.
3476	>	*
3477	>	* @param parallelismThreshold the (estimated) number of elements
3478	>	* needed for this operation to be executed in parallel
3479	>	* @param transformer a function returning the transformation
3480	>	* for an element, or null if there is no transformation (in
3481	>	* which case the action is not applied)
3482	>	* @param action the action
3483	>	* @since 1.8
3484	>	*/
3485	>	public <U> void forEachKey(long parallelismThreshold,
3486	>	Function<? super K, ? extends U> transformer,
3487	>	Consumer<? super U> action) {
3488	>	if (transformer == null || action == null)
3489	>	throw new NullPointerException();
3490	>	new ForEachTransformedKeyTask<K,V,U>
3491	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3492	>	transformer, action).invoke();
3493		}
3494
3495	<
3495	>	/**
3496	>	* Returns a non-null result from applying the given search
3497	>	* function on each key, or null if none. Upon success,
3498	>	* further element processing is suppressed and the results of
3499	>	* any other parallel invocations of the search function are
3500	>	* ignored.
3501	>	*
3502	>	* @param parallelismThreshold the (estimated) number of elements
3503	>	* needed for this operation to be executed in parallel
3504	>	* @param searchFunction a function returning a non-null
3505	>	* result on success, else null
3506	>	* @return a non-null result from applying the given search
3507	>	* function on each key, or null if none
3508	>	* @since 1.8
3509	>	*/
3510	>	public <U> U searchKeys(long parallelismThreshold,
3511	>	Function<? super K, ? extends U> searchFunction) {
3512	>	if (searchFunction == null) throw new NullPointerException();
3513	>	return new SearchKeysTask<K,V,U>
3514	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3515	>	searchFunction, new AtomicReference<U>()).invoke();
3516	>	}
3517
3518		/**
3519	<	* Exported Entry objects must write-through changes in setValue,
3520	<	* even if the nodes have been cloned. So we cannot return
3521	<	* internal HashEntry objects. Instead, the iterator itself acts
3522	<	* as a forwarding pseudo-entry.
3519	>	* Returns the result of accumulating all keys using the given
3520	>	* reducer to combine values, or null if none.
3521	>	*
3522	>	* @param parallelismThreshold the (estimated) number of elements
3523	>	* needed for this operation to be executed in parallel
3524	>	* @param reducer a commutative associative combining function
3525	>	* @return the result of accumulating all keys using the given
3526	>	* reducer to combine values, or null if none
3527	>	* @since 1.8
3528		*/
3529	<	private class EntryIterator extends HashIterator implements Map.Entry<K,V>, Iterator<Entry<K,V>> {
3530	<	public Map.Entry<K,V> next() {
3531	<	nextEntry();
3532	<	return this;
3529	>	public K reduceKeys(long parallelismThreshold,
3530	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3531	>	if (reducer == null) throw new NullPointerException();
3532	>	return new ReduceKeysTask<K,V>
3533	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3534	>	null, reducer).invoke();
3535	>	}
3536	>
3537	>	/**
3538	>	* Returns the result of accumulating the given transformation
3539	>	* of all keys using the given reducer to combine values, or
3540	>	* null if none.
3541	>	*
3542	>	* @param parallelismThreshold the (estimated) number of elements
3543	>	* needed for this operation to be executed in parallel
3544	>	* @param transformer a function returning the transformation
3545	>	* for an element, or null if there is no transformation (in
3546	>	* which case it is not combined)
3547	>	* @param reducer a commutative associative combining function
3548	>	* @return the result of accumulating the given transformation
3549	>	* of all keys
3550	>	* @since 1.8
3551	>	*/
3552	>	public <U> U reduceKeys(long parallelismThreshold,
3553	>	Function<? super K, ? extends U> transformer,
3554	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3555	>	if (transformer == null || reducer == null)
3556	>	throw new NullPointerException();
3557	>	return new MapReduceKeysTask<K,V,U>
3558	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3559	>	null, transformer, reducer).invoke();
3560	>	}
3561	>
3562	>	/**
3563	>	* Returns the result of accumulating the given transformation
3564	>	* of all keys using the given reducer to combine values, and
3565	>	* the given basis as an identity value.
3566	>	*
3567	>	* @param parallelismThreshold the (estimated) number of elements
3568	>	* needed for this operation to be executed in parallel
3569	>	* @param transformer a function returning the transformation
3570	>	* for an element
3571	>	* @param basis the identity (initial default value) for the reduction
3572	>	* @param reducer a commutative associative combining function
3573	>	* @return the result of accumulating the given transformation
3574	>	* of all keys
3575	>	* @since 1.8
3576	>	*/
3577	>	public double reduceKeysToDouble(long parallelismThreshold,
3578	>	ToDoubleFunction<? super K> transformer,
3579	>	double basis,
3580	>	DoubleBinaryOperator reducer) {
3581	>	if (transformer == null || reducer == null)
3582	>	throw new NullPointerException();
3583	>	return new MapReduceKeysToDoubleTask<K,V>
3584	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3585	>	null, transformer, basis, reducer).invoke();
3586	>	}
3587	>
3588	>	/**
3589	>	* Returns the result of accumulating the given transformation
3590	>	* of all keys using the given reducer to combine values, and
3591	>	* the given basis as an identity value.
3592	>	*
3593	>	* @param parallelismThreshold the (estimated) number of elements
3594	>	* needed for this operation to be executed in parallel
3595	>	* @param transformer a function returning the transformation
3596	>	* for an element
3597	>	* @param basis the identity (initial default value) for the reduction
3598	>	* @param reducer a commutative associative combining function
3599	>	* @return the result of accumulating the given transformation
3600	>	* of all keys
3601	>	* @since 1.8
3602	>	*/
3603	>	public long reduceKeysToLong(long parallelismThreshold,
3604	>	ToLongFunction<? super K> transformer,
3605	>	long basis,
3606	>	LongBinaryOperator reducer) {
3607	>	if (transformer == null || reducer == null)
3608	>	throw new NullPointerException();
3609	>	return new MapReduceKeysToLongTask<K,V>
3610	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3611	>	null, transformer, basis, reducer).invoke();
3612	>	}
3613	>
3614	>	/**
3615	>	* Returns the result of accumulating the given transformation
3616	>	* of all keys using the given reducer to combine values, and
3617	>	* the given basis as an identity value.
3618	>	*
3619	>	* @param parallelismThreshold the (estimated) number of elements
3620	>	* needed for this operation to be executed in parallel
3621	>	* @param transformer a function returning the transformation
3622	>	* for an element
3623	>	* @param basis the identity (initial default value) for the reduction
3624	>	* @param reducer a commutative associative combining function
3625	>	* @return the result of accumulating the given transformation
3626	>	* of all keys
3627	>	* @since 1.8
3628	>	*/
3629	>	public int reduceKeysToInt(long parallelismThreshold,
3630	>	ToIntFunction<? super K> transformer,
3631	>	int basis,
3632	>	IntBinaryOperator reducer) {
3633	>	if (transformer == null || reducer == null)
3634	>	throw new NullPointerException();
3635	>	return new MapReduceKeysToIntTask<K,V>
3636	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3637	>	null, transformer, basis, reducer).invoke();
3638	>	}
3639	>
3640	>	/**
3641	>	* Performs the given action for each value.
3642	>	*
3643	>	* @param parallelismThreshold the (estimated) number of elements
3644	>	* needed for this operation to be executed in parallel
3645	>	* @param action the action
3646	>	* @since 1.8
3647	>	*/
3648	>	public void forEachValue(long parallelismThreshold,
3649	>	Consumer<? super V> action) {
3650	>	if (action == null)
3651	>	throw new NullPointerException();
3652	>	new ForEachValueTask<K,V>
3653	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3654	>	action).invoke();
3655	>	}
3656	>
3657	>	/**
3658	>	* Performs the given action for each non-null transformation
3659	>	* of each value.
3660	>	*
3661	>	* @param parallelismThreshold the (estimated) number of elements
3662	>	* needed for this operation to be executed in parallel
3663	>	* @param transformer a function returning the transformation
3664	>	* for an element, or null if there is no transformation (in
3665	>	* which case the action is not applied)
3666	>	* @param action the action
3667	>	* @since 1.8
3668	>	*/
3669	>	public <U> void forEachValue(long parallelismThreshold,
3670	>	Function<? super V, ? extends U> transformer,
3671	>	Consumer<? super U> action) {
3672	>	if (transformer == null || action == null)
3673	>	throw new NullPointerException();
3674	>	new ForEachTransformedValueTask<K,V,U>
3675	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3676	>	transformer, action).invoke();
3677	>	}
3678	>
3679	>	/**
3680	>	* Returns a non-null result from applying the given search
3681	>	* function on each value, or null if none.  Upon success,
3682	>	* further element processing is suppressed and the results of
3683	>	* any other parallel invocations of the search function are
3684	>	* ignored.
3685	>	*
3686	>	* @param parallelismThreshold the (estimated) number of elements
3687	>	* needed for this operation to be executed in parallel
3688	>	* @param searchFunction a function returning a non-null
3689	>	* result on success, else null
3690	>	* @return a non-null result from applying the given search
3691	>	* function on each value, or null if none
3692	>	* @since 1.8
3693	>	*/
3694	>	public <U> U searchValues(long parallelismThreshold,
3695	>	Function<? super V, ? extends U> searchFunction) {
3696	>	if (searchFunction == null) throw new NullPointerException();
3697	>	return new SearchValuesTask<K,V,U>
3698	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3699	>	searchFunction, new AtomicReference<U>()).invoke();
3700	>	}
3701	>
3702	>	/**
3703	>	* Returns the result of accumulating all values using the
3704	>	* given reducer to combine values, or null if none.
3705	>	*
3706	>	* @param parallelismThreshold the (estimated) number of elements
3707	>	* needed for this operation to be executed in parallel
3708	>	* @param reducer a commutative associative combining function
3709	>	* @return the result of accumulating all values
3710	>	* @since 1.8
3711	>	*/
3712	>	public V reduceValues(long parallelismThreshold,
3713	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
3714	>	if (reducer == null) throw new NullPointerException();
3715	>	return new ReduceValuesTask<K,V>
3716	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3717	>	null, reducer).invoke();
3718	>	}
3719	>
3720	>	/**
3721	>	* Returns the result of accumulating the given transformation
3722	>	* of all values using the given reducer to combine values, or
3723	>	* null if none.
3724	>	*
3725	>	* @param parallelismThreshold the (estimated) number of elements
3726	>	* needed for this operation to be executed in parallel
3727	>	* @param transformer a function returning the transformation
3728	>	* for an element, or null if there is no transformation (in
3729	>	* which case it is not combined)
3730	>	* @param reducer a commutative associative combining function
3731	>	* @return the result of accumulating the given transformation
3732	>	* of all values
3733	>	* @since 1.8
3734	>	*/
3735	>	public <U> U reduceValues(long parallelismThreshold,
3736	>	Function<? super V, ? extends U> transformer,
3737	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3738	>	if (transformer == null || reducer == null)
3739	>	throw new NullPointerException();
3740	>	return new MapReduceValuesTask<K,V,U>
3741	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3742	>	null, transformer, reducer).invoke();
3743	>	}
3744	>
3745	>	/**
3746	>	* Returns the result of accumulating the given transformation
3747	>	* of all values using the given reducer to combine values,
3748	>	* and the given basis as an identity value.
3749	>	*
3750	>	* @param parallelismThreshold the (estimated) number of elements
3751	>	* needed for this operation to be executed in parallel
3752	>	* @param transformer a function returning the transformation
3753	>	* for an element
3754	>	* @param basis the identity (initial default value) for the reduction
3755	>	* @param reducer a commutative associative combining function
3756	>	* @return the result of accumulating the given transformation
3757	>	* of all values
3758	>	* @since 1.8
3759	>	*/
3760	>	public double reduceValuesToDouble(long parallelismThreshold,
3761	>	ToDoubleFunction<? super V> transformer,
3762	>	double basis,
3763	>	DoubleBinaryOperator reducer) {
3764	>	if (transformer == null || reducer == null)
3765	>	throw new NullPointerException();
3766	>	return new MapReduceValuesToDoubleTask<K,V>
3767	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3768	>	null, transformer, basis, reducer).invoke();
3769	>	}
3770	>
3771	>	/**
3772	>	* Returns the result of accumulating the given transformation
3773	>	* of all values using the given reducer to combine values,
3774	>	* and the given basis as an identity value.
3775	>	*
3776	>	* @param parallelismThreshold the (estimated) number of elements
3777	>	* needed for this operation to be executed in parallel
3778	>	* @param transformer a function returning the transformation
3779	>	* for an element
3780	>	* @param basis the identity (initial default value) for the reduction
3781	>	* @param reducer a commutative associative combining function
3782	>	* @return the result of accumulating the given transformation
3783	>	* of all values
3784	>	* @since 1.8
3785	>	*/
3786	>	public long reduceValuesToLong(long parallelismThreshold,
3787	>	ToLongFunction<? super V> transformer,
3788	>	long basis,
3789	>	LongBinaryOperator reducer) {
3790	>	if (transformer == null || reducer == null)
3791	>	throw new NullPointerException();
3792	>	return new MapReduceValuesToLongTask<K,V>
3793	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3794	>	null, transformer, basis, reducer).invoke();
3795	>	}
3796	>
3797	>	/**
3798	>	* Returns the result of accumulating the given transformation
3799	>	* of all values using the given reducer to combine values,
3800	>	* and the given basis as an identity value.
3801	>	*
3802	>	* @param parallelismThreshold the (estimated) number of elements
3803	>	* needed for this operation to be executed in parallel
3804	>	* @param transformer a function returning the transformation
3805	>	* for an element
3806	>	* @param basis the identity (initial default value) for the reduction
3807	>	* @param reducer a commutative associative combining function
3808	>	* @return the result of accumulating the given transformation
3809	>	* of all values
3810	>	* @since 1.8
3811	>	*/
3812	>	public int reduceValuesToInt(long parallelismThreshold,
3813	>	ToIntFunction<? super V> transformer,
3814	>	int basis,
3815	>	IntBinaryOperator reducer) {
3816	>	if (transformer == null || reducer == null)
3817	>	throw new NullPointerException();
3818	>	return new MapReduceValuesToIntTask<K,V>
3819	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3820	>	null, transformer, basis, reducer).invoke();
3821	>	}
3822	>
3823	>	/**
3824	>	* Performs the given action for each entry.
3825	>	*
3826	>	* @param parallelismThreshold the (estimated) number of elements
3827	>	* needed for this operation to be executed in parallel
3828	>	* @param action the action
3829	>	* @since 1.8
3830	>	*/
3831	>	public void forEachEntry(long parallelismThreshold,
3832	>	Consumer<? super Map.Entry<K,V>> action) {
3833	>	if (action == null) throw new NullPointerException();
3834	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
3835	>	action).invoke();
3836	>	}
3837	>
3838	>	/**
3839	>	* Performs the given action for each non-null transformation
3840	>	* of each entry.
3841	>	*
3842	>	* @param parallelismThreshold the (estimated) number of elements
3843	>	* needed for this operation to be executed in parallel
3844	>	* @param transformer a function returning the transformation
3845	>	* for an element, or null if there is no transformation (in
3846	>	* which case the action is not applied)
3847	>	* @param action the action
3848	>	* @since 1.8
3849	>	*/
3850	>	public <U> void forEachEntry(long parallelismThreshold,
3851	>	Function<Map.Entry<K,V>, ? extends U> transformer,
3852	>	Consumer<? super U> action) {
3853	>	if (transformer == null || action == null)
3854	>	throw new NullPointerException();
3855	>	new ForEachTransformedEntryTask<K,V,U>
3856	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3857	>	transformer, action).invoke();
3858	>	}
3859	>
3860	>	/**
3861	>	* Returns a non-null result from applying the given search
3862	>	* function on each entry, or null if none.  Upon success,
3863	>	* further element processing is suppressed and the results of
3864	>	* any other parallel invocations of the search function are
3865	>	* ignored.
3866	>	*
3867	>	* @param parallelismThreshold the (estimated) number of elements
3868	>	* needed for this operation to be executed in parallel
3869	>	* @param searchFunction a function returning a non-null
3870	>	* result on success, else null
3871	>	* @return a non-null result from applying the given search
3872	>	* function on each entry, or null if none
3873	>	* @since 1.8
3874	>	*/
3875	>	public <U> U searchEntries(long parallelismThreshold,
3876	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
3877	>	if (searchFunction == null) throw new NullPointerException();
3878	>	return new SearchEntriesTask<K,V,U>
3879	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3880	>	searchFunction, new AtomicReference<U>()).invoke();
3881	>	}
3882	>
3883	>	/**
3884	>	* Returns the result of accumulating all entries using the
3885	>	* given reducer to combine values, or null if none.
3886	>	*
3887	>	* @param parallelismThreshold the (estimated) number of elements
3888	>	* needed for this operation to be executed in parallel
3889	>	* @param reducer a commutative associative combining function
3890	>	* @return the result of accumulating all entries
3891	>	* @since 1.8
3892	>	*/
3893	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
3894	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3895	>	if (reducer == null) throw new NullPointerException();
3896	>	return new ReduceEntriesTask<K,V>
3897	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3898	>	null, reducer).invoke();
3899	>	}
3900	>
3901	>	/**
3902	>	* Returns the result of accumulating the given transformation
3903	>	* of all entries using the given reducer to combine values,
3904	>	* or null if none.
3905	>	*
3906	>	* @param parallelismThreshold the (estimated) number of elements
3907	>	* needed for this operation to be executed in parallel
3908	>	* @param transformer a function returning the transformation
3909	>	* for an element, or null if there is no transformation (in
3910	>	* which case it is not combined)
3911	>	* @param reducer a commutative associative combining function
3912	>	* @return the result of accumulating the given transformation
3913	>	* of all entries
3914	>	* @since 1.8
3915	>	*/
3916	>	public <U> U reduceEntries(long parallelismThreshold,
3917	>	Function<Map.Entry<K,V>, ? extends U> transformer,
3918	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3919	>	if (transformer == null || reducer == null)
3920	>	throw new NullPointerException();
3921	>	return new MapReduceEntriesTask<K,V,U>
3922	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3923	>	null, transformer, reducer).invoke();
3924	>	}
3925	>
3926	>	/**
3927	>	* Returns the result of accumulating the given transformation
3928	>	* of all entries using the given reducer to combine values,
3929	>	* and the given basis as an identity value.
3930	>	*
3931	>	* @param parallelismThreshold the (estimated) number of elements
3932	>	* needed for this operation to be executed in parallel
3933	>	* @param transformer a function returning the transformation
3934	>	* for an element
3935	>	* @param basis the identity (initial default value) for the reduction
3936	>	* @param reducer a commutative associative combining function
3937	>	* @return the result of accumulating the given transformation
3938	>	* of all entries
3939	>	* @since 1.8
3940	>	*/
3941	>	public double reduceEntriesToDouble(long parallelismThreshold,
3942	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
3943	>	double basis,
3944	>	DoubleBinaryOperator reducer) {
3945	>	if (transformer == null || reducer == null)
3946	>	throw new NullPointerException();
3947	>	return new MapReduceEntriesToDoubleTask<K,V>
3948	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3949	>	null, transformer, basis, reducer).invoke();
3950	>	}
3951	>
3952	>	/**
3953	>	* Returns the result of accumulating the given transformation
3954	>	* of all entries using the given reducer to combine values,
3955	>	* and the given basis as an identity value.
3956	>	*
3957	>	* @param parallelismThreshold the (estimated) number of elements
3958	>	* needed for this operation to be executed in parallel
3959	>	* @param transformer a function returning the transformation
3960	>	* for an element
3961	>	* @param basis the identity (initial default value) for the reduction
3962	>	* @param reducer a commutative associative combining function
3963	>	* @return the result of accumulating the given transformation
3964	>	* of all entries
3965	>	* @since 1.8
3966	>	*/
3967	>	public long reduceEntriesToLong(long parallelismThreshold,
3968	>	ToLongFunction<Map.Entry<K,V>> transformer,
3969	>	long basis,
3970	>	LongBinaryOperator reducer) {
3971	>	if (transformer == null || reducer == null)
3972	>	throw new NullPointerException();
3973	>	return new MapReduceEntriesToLongTask<K,V>
3974	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3975	>	null, transformer, basis, reducer).invoke();
3976	>	}
3977	>
3978	>	/**
3979	>	* Returns the result of accumulating the given transformation
3980	>	* of all entries using the given reducer to combine values,
3981	>	* and the given basis as an identity value.
3982	>	*
3983	>	* @param parallelismThreshold the (estimated) number of elements
3984	>	* needed for this operation to be executed in parallel
3985	>	* @param transformer a function returning the transformation
3986	>	* for an element
3987	>	* @param basis the identity (initial default value) for the reduction
3988	>	* @param reducer a commutative associative combining function
3989	>	* @return the result of accumulating the given transformation
3990	>	* of all entries
3991	>	* @since 1.8
3992	>	*/
3993	>	public int reduceEntriesToInt(long parallelismThreshold,
3994	>	ToIntFunction<Map.Entry<K,V>> transformer,
3995	>	int basis,
3996	>	IntBinaryOperator reducer) {
3997	>	if (transformer == null || reducer == null)
3998	>	throw new NullPointerException();
3999	>	return new MapReduceEntriesToIntTask<K,V>
4000	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4001	>	null, transformer, basis, reducer).invoke();
4002	>	}
4003	>
4004	>
4005	>	/* ----------------Views -------------- */
4006	>
4007	>	/**
4008	>	* Base class for views.
4009	>	*/
4010	>	abstract static class CollectionView<K,V,E>
4011	>	implements Collection<E>, java.io.Serializable {
4012	>	private static final long serialVersionUID = 7249069246763182397L;
4013	>	final ConcurrentHashMap<K,V> map;
4014	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4015	>
4016	>	/**
4017	>	* Returns the map backing this view.
4018	>	*
4019	>	* @return the map backing this view
4020	>	*/
4021	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4022	>
4023	>	/**
4024	>	* Removes all of the elements from this view, by removing all
4025	>	* the mappings from the map backing this view.
4026	>	*/
4027	>	public final void clear()      { map.clear(); }
4028	>	public final int size()        { return map.size(); }
4029	>	public final boolean isEmpty() { return map.isEmpty(); }
4030	>
4031	>	// implementations below rely on concrete classes supplying these
4032	>	// abstract methods
4033	>	/**
4034	>	* Returns a "weakly consistent" iterator that will never
4035	>	* throw {@link ConcurrentModificationException}, and
4036	>	* guarantees to traverse elements as they existed upon
4037	>	* construction of the iterator, and may (but is not
4038	>	* guaranteed to) reflect any modifications subsequent to
4039	>	* construction.
4040	>	*/
4041	>	public abstract Iterator<E> iterator();
4042	>	public abstract boolean contains(Object o);
4043	>	public abstract boolean remove(Object o);
4044	>
4045	>	private static final String oomeMsg = "Required array size too large";
4046	>
4047	>	public final Object[] toArray() {
4048	>	long sz = map.mappingCount();
4049	>	if (sz > MAX_ARRAY_SIZE)
4050	>	throw new OutOfMemoryError(oomeMsg);
4051	>	int n = (int)sz;
4052	>	Object[] r = new Object[n];
4053	>	int i = 0;
4054	>	for (E e : this) {
4055	>	if (i == n) {
4056	>	if (n >= MAX_ARRAY_SIZE)
4057	>	throw new OutOfMemoryError(oomeMsg);
4058	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4059	>	n = MAX_ARRAY_SIZE;
4060	>	else
4061	>	n += (n >>> 1) + 1;
4062	>	r = Arrays.copyOf(r, n);
4063	>	}
4064	>	r[i++] = e;
4065	>	}
4066	>	return (i == n) ? r : Arrays.copyOf(r, i);
4067		}
4068
4069	<	public K getKey() {
4070	<	if (lastReturned == null)
4071	<	throw new IllegalStateException("Entry was removed");
4072	<	return lastReturned.key;
4069	>	public final <T> T[] toArray(T[] a) {
4070	>	long sz = map.mappingCount();
4071	>	if (sz > MAX_ARRAY_SIZE)
4072	>	throw new OutOfMemoryError(oomeMsg);
4073	>	int m = (int)sz;
4074	>	T[] r = (a.length >= m) ? a :
4075	>	(T[])java.lang.reflect.Array
4076	>	.newInstance(a.getClass().getComponentType(), m);
4077	>	int n = r.length;
4078	>	int i = 0;
4079	>	for (E e : this) {
4080	>	if (i == n) {
4081	>	if (n >= MAX_ARRAY_SIZE)
4082	>	throw new OutOfMemoryError(oomeMsg);
4083	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4084	>	n = MAX_ARRAY_SIZE;
4085	>	else
4086	>	n += (n >>> 1) + 1;
4087	>	r = Arrays.copyOf(r, n);
4088	>	}
4089	>	r[i++] = (T)e;
4090	>	}
4091	>	if (a == r && i < n) {
4092	>	r[i] = null; // null-terminate
4093	>	return r;
4094	>	}
4095	>	return (i == n) ? r : Arrays.copyOf(r, i);
4096		}
4097
4098	<	public V getValue() {
4099	<	if (lastReturned == null)
4100	<	throw new IllegalStateException("Entry was removed");
4101	<	return ConcurrentHashMap.this.get(lastReturned.key);
4098	>	/**
4099	>	* Returns a string representation of this collection.
4100	>	* The string representation consists of the string representations
4101	>	* of the collection's elements in the order they are returned by
4102	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4103	>	* Adjacent elements are separated by the characters {@code ", "}
4104	>	* (comma and space).  Elements are converted to strings as by
4105	>	* {@link String#valueOf(Object)}.
4106	>	*
4107	>	* @return a string representation of this collection
4108	>	*/
4109	>	public final String toString() {
4110	>	StringBuilder sb = new StringBuilder();
4111	>	sb.append('[');
4112	>	Iterator<E> it = iterator();
4113	>	if (it.hasNext()) {
4114	>	for (;;) {
4115	>	Object e = it.next();
4116	>	sb.append(e == this ? "(this Collection)" : e);
4117	>	if (!it.hasNext())
4118	>	break;
4119	>	sb.append(',').append(' ');
4120	>	}
4121	>	}
4122	>	return sb.append(']').toString();
4123		}
4124
4125	<	public V setValue(V value) {
4126	<	if (lastReturned == null)
4127	<	throw new IllegalStateException("Entry was removed");
4128	<	return ConcurrentHashMap.this.put(lastReturned.key, value);
4125	>	public final boolean containsAll(Collection<?> c) {
4126	>	if (c != this) {
4127	>	for (Object e : c) {
4128	>	if (e == null || !contains(e))
4129	>	return false;
4130	>	}
4131	>	}
4132	>	return true;
4133		}
4134
4135	<	public boolean equals(Object o) {
4136	<	if (!(o instanceof Map.Entry))
4137	<	return false;
4138	<	Map.Entry e = (Map.Entry)o;
4139	<	return eq(getKey(), e.getKey()) && eq(getValue(), e.getValue());
4140	<	}
4135	>	public final boolean removeAll(Collection<?> c) {
4136	>	boolean modified = false;
4137	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4138	>	if (c.contains(it.next())) {
4139	>	it.remove();
4140	>	modified = true;
4141	>	}
4142	>	}
4143	>	return modified;
4144	>	}
4145
4146	<	public int hashCode() {
4147	<	Object k = getKey();
4148	<	Object v = getValue();
4149	<	return ((k == null) ? 0 : k.hashCode()) ^
4150	<	((v == null) ? 0 : v.hashCode());
4146	>	public final boolean retainAll(Collection<?> c) {
4147	>	boolean modified = false;
4148	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4149	>	if (!c.contains(it.next())) {
4150	>	it.remove();
4151	>	modified = true;
4152	>	}
4153	>	}
4154	>	return modified;
4155		}
4156
4157	<	public String toString() {
4158	<	return getKey() + "=" + getValue();
4157	>	}
4158	>
4159	>	/**
4160	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4161	>	* which additions may optionally be enabled by mapping to a
4162	>	* common value.  This class cannot be directly instantiated.
4163	>	* See {@link #keySet() keySet()},
4164	>	* {@link #keySet(Object) keySet(V)},
4165	>	* {@link #newKeySet() newKeySet()},
4166	>	* {@link #newKeySet(int) newKeySet(int)}.
4167	>	*
4168	>	* @since 1.8
4169	>	*/
4170	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4171	>	implements Set<K>, java.io.Serializable {
4172	>	private static final long serialVersionUID = 7249069246763182397L;
4173	>	private final V value;
4174	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4175	>	super(map);
4176	>	this.value = value;
4177	>	}
4178	>
4179	>	/**
4180	>	* Returns the default mapped value for additions,
4181	>	* or {@code null} if additions are not supported.
4182	>	*
4183	>	* @return the default mapped value for additions, or {@code null}
4184	>	* if not supported
4185	>	*/
4186	>	public V getMappedValue() { return value; }
4187	>
4188	>	/**
4189	>	* {@inheritDoc}
4190	>	* @throws NullPointerException if the specified key is null
4191	>	*/
4192	>	public boolean contains(Object o) { return map.containsKey(o); }
4193	>
4194	>	/**
4195	>	* Removes the key from this map view, by removing the key (and its
4196	>	* corresponding value) from the backing map.  This method does
4197	>	* nothing if the key is not in the map.
4198	>	*
4199	>	* @param  o the key to be removed from the backing map
4200	>	* @return {@code true} if the backing map contained the specified key
4201	>	* @throws NullPointerException if the specified key is null
4202	>	*/
4203	>	public boolean remove(Object o) { return map.remove(o) != null; }
4204	>
4205	>	/**
4206	>	* @return an iterator over the keys of the backing map
4207	>	*/
4208	>	public Iterator<K> iterator() {
4209	>	Node<K,V>[] t;
4210	>	ConcurrentHashMap<K,V> m = map;
4211	>	int f = (t = m.table) == null ? 0 : t.length;
4212	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4213	>	}
4214	>
4215	>	/**
4216	>	* Adds the specified key to this set view by mapping the key to
4217	>	* the default mapped value in the backing map, if defined.
4218	>	*
4219	>	* @param e key to be added
4220	>	* @return {@code true} if this set changed as a result of the call
4221	>	* @throws NullPointerException if the specified key is null
4222	>	* @throws UnsupportedOperationException if no default mapped value
4223	>	* for additions was provided
4224	>	*/
4225	>	public boolean add(K e) {
4226	>	V v;
4227	>	if ((v = value) == null)
4228	>	throw new UnsupportedOperationException();
4229	>	return map.internalPut(e, v, true) == null;
4230	>	}
4231	>
4232	>	/**
4233	>	* Adds all of the elements in the specified collection to this set,
4234	>	* as if by calling {@link #add} on each one.
4235	>	*
4236	>	* @param c the elements to be inserted into this set
4237	>	* @return {@code true} if this set changed as a result of the call
4238	>	* @throws NullPointerException if the collection or any of its
4239	>	* elements are {@code null}
4240	>	* @throws UnsupportedOperationException if no default mapped value
4241	>	* for additions was provided
4242	>	*/
4243	>	public boolean addAll(Collection<? extends K> c) {
4244	>	boolean added = false;
4245	>	V v;
4246	>	if ((v = value) == null)
4247	>	throw new UnsupportedOperationException();
4248	>	for (K e : c) {
4249	>	if (map.internalPut(e, v, true) == null)
4250	>	added = true;
4251	>	}
4252	>	return added;
4253		}
4254
4255	<	private boolean eq(Object o1, Object o2) {
4256	<	return (o1 == null ? o2 == null : o1.equals(o2));
4255	>	public int hashCode() {
4256	>	int h = 0;
4257	>	for (K e : this)
4258	>	h += e.hashCode();
4259	>	return h;
4260		}
4261
4262	+	public boolean equals(Object o) {
4263	+	Set<?> c;
4264	+	return ((o instanceof Set) &&
4265	+	((c = (Set<?>)o) == this ||
4266	+	(containsAll(c) && c.containsAll(this))));
4267	+	}
4268	+
4269	+	public Spliterator<K> spliterator() {
4270	+	Node<K,V>[] t;
4271	+	ConcurrentHashMap<K,V> m = map;
4272	+	long n = m.sumCount();
4273	+	int f = (t = m.table) == null ? 0 : t.length;
4274	+	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4275	+	}
4276	+
4277	+	public void forEach(Consumer<? super K> action) {
4278	+	if (action == null) throw new NullPointerException();
4279	+	Node<K,V>[] t;
4280	+	if ((t = map.table) != null) {
4281	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4282	+	for (Node<K,V> p; (p = it.advance()) != null; )
4283	+	action.accept((K)p.key);
4284	+	}
4285	+	}
4286		}
4287
4288	<	private class KeySet extends AbstractSet<K> {
4289	<	public Iterator<K> iterator() {
4290	<	return new KeyIterator();
4288	>	/**
4289	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4290	>	* values, in which additions are disabled. This class cannot be
4291	>	* directly instantiated. See {@link #values()}.
4292	>	*/
4293	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4294	>	implements Collection<V>, java.io.Serializable {
4295	>	private static final long serialVersionUID = 2249069246763182397L;
4296	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4297	>	public final boolean contains(Object o) {
4298	>	return map.containsValue(o);
4299	>	}
4300	>
4301	>	public final boolean remove(Object o) {
4302	>	if (o != null) {
4303	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4304	>	if (o.equals(it.next())) {
4305	>	it.remove();
4306	>	return true;
4307	>	}
4308	>	}
4309	>	}
4310	>	return false;
4311		}
4312	<	public int size() {
4313	<	return ConcurrentHashMap.this.size();
4312	>
4313	>	public final Iterator<V> iterator() {
4314	>	ConcurrentHashMap<K,V> m = map;
4315	>	Node<K,V>[] t;
4316	>	int f = (t = m.table) == null ? 0 : t.length;
4317	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4318	>	}
4319	>
4320	>	public final boolean add(V e) {
4321	>	throw new UnsupportedOperationException();
4322	>	}
4323	>	public final boolean addAll(Collection<? extends V> c) {
4324	>	throw new UnsupportedOperationException();
4325	>	}
4326	>
4327	>	public Spliterator<V> spliterator() {
4328	>	Node<K,V>[] t;
4329	>	ConcurrentHashMap<K,V> m = map;
4330	>	long n = m.sumCount();
4331	>	int f = (t = m.table) == null ? 0 : t.length;
4332	>	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4333	>	}
4334	>
4335	>	public void forEach(Consumer<? super V> action) {
4336	>	if (action == null) throw new NullPointerException();
4337	>	Node<K,V>[] t;
4338	>	if ((t = map.table) != null) {
4339	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4340	>	for (Node<K,V> p; (p = it.advance()) != null; )
4341	>	action.accept(p.val);
4342	>	}
4343		}
4344	+	}
4345	+
4346	+	/**
4347	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4348	+	* entries.  This class cannot be directly instantiated. See
4349	+	* {@link #entrySet()}.
4350	+	*/
4351	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4352	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4353	+	private static final long serialVersionUID = 2249069246763182397L;
4354	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4355	+
4356		public boolean contains(Object o) {
4357	<	return ConcurrentHashMap.this.containsKey(o);
4357	>	Object k, v, r; Map.Entry<?,?> e;
4358	>	return ((o instanceof Map.Entry) &&
4359	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4360	>	(r = map.get(k)) != null &&
4361	>	(v = e.getValue()) != null &&
4362	>	(v == r || v.equals(r)));
4363		}
4364	+
4365		public boolean remove(Object o) {
4366	<	return ConcurrentHashMap.this.remove(o) != null;
4366	>	Object k, v; Map.Entry<?,?> e;
4367	>	return ((o instanceof Map.Entry) &&
4368	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4369	>	(v = e.getValue()) != null &&
4370	>	map.remove(k, v));
4371	>	}
4372	>
4373	>	/**
4374	>	* @return an iterator over the entries of the backing map
4375	>	*/
4376	>	public Iterator<Map.Entry<K,V>> iterator() {
4377	>	ConcurrentHashMap<K,V> m = map;
4378	>	Node<K,V>[] t;
4379	>	int f = (t = m.table) == null ? 0 : t.length;
4380	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4381		}
4382	<	public void clear() {
4383	<	ConcurrentHashMap.this.clear();
4382	>
4383	>	public boolean add(Entry<K,V> e) {
4384	>	return map.internalPut(e.getKey(), e.getValue(), false) == null;
4385	>	}
4386	>
4387	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4388	>	boolean added = false;
4389	>	for (Entry<K,V> e : c) {
4390	>	if (add(e))
4391	>	added = true;
4392	>	}
4393	>	return added;
4394	>	}
4395	>
4396	>	public final int hashCode() {
4397	>	int h = 0;
4398	>	Node<K,V>[] t;
4399	>	if ((t = map.table) != null) {
4400	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4401	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4402	>	h += p.hashCode();
4403	>	}
4404	>	}
4405	>	return h;
4406		}
4407	+
4408	+	public final boolean equals(Object o) {
4409	+	Set<?> c;
4410	+	return ((o instanceof Set) &&
4411	+	((c = (Set<?>)o) == this ||
4412	+	(containsAll(c) && c.containsAll(this))));
4413	+	}
4414	+
4415	+	public Spliterator<Map.Entry<K,V>> spliterator() {
4416	+	Node<K,V>[] t;
4417	+	ConcurrentHashMap<K,V> m = map;
4418	+	long n = m.sumCount();
4419	+	int f = (t = m.table) == null ? 0 : t.length;
4420	+	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4421	+	}
4422	+
4423	+	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4424	+	if (action == null) throw new NullPointerException();
4425	+	Node<K,V>[] t;
4426	+	if ((t = map.table) != null) {
4427	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4428	+	for (Node<K,V> p; (p = it.advance()) != null; )
4429	+	action.accept(new MapEntry<K,V>((K)p.key, p.val, map));
4430	+	}
4431	+	}
4432	+
4433		}
4434
4435	<	private class Values extends AbstractCollection<V> {
4436	<	public Iterator<V> iterator() {
4437	<	return new ValueIterator();
4435	>	// -------------------------------------------------------
4436	>
4437	>	/**
4438	>	* Base class for bulk tasks. Repeats some fields and code from
4439	>	* class Traverser, because we need to subclass CountedCompleter.
4440	>	*/
4441	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4442	>	Node<K,V>[] tab;        // same as Traverser
4443	>	Node<K,V> next;
4444	>	int index;
4445	>	int baseIndex;
4446	>	int baseLimit;
4447	>	final int baseSize;
4448	>	int batch;              // split control
4449	>
4450	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4451	>	super(par);
4452	>	this.batch = b;
4453	>	this.index = this.baseIndex = i;
4454	>	if ((this.tab = t) == null)
4455	>	this.baseSize = this.baseLimit = 0;
4456	>	else if (par == null)
4457	>	this.baseSize = this.baseLimit = t.length;
4458	>	else {
4459	>	this.baseLimit = f;
4460	>	this.baseSize = par.baseSize;
4461	>	}
4462		}
4463	<	public int size() {
4464	<	return ConcurrentHashMap.this.size();
4463	>
4464	>	/**
4465	>	* Same as Traverser version
4466	>	*/
4467	>	final Node<K,V> advance() {
4468	>	Node<K,V> e;
4469	>	if ((e = next) != null)
4470	>	e = e.next;
4471	>	for (;;) {
4472	>	Node<K,V>[] t; int i, n; Object ek;
4473	>	if (e != null)
4474	>	return next = e;
4475	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4476	>	(n = t.length) <= (i = index) || i < 0)
4477	>	return next = null;
4478	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4479	>	if ((ek = e.key) instanceof TreeBin)
4480	>	e = ((TreeBin<K,V>)ek).first;
4481	>	else {
4482	>	tab = (Node<K,V>[])ek;
4483	>	e = null;
4484	>	continue;
4485	>	}
4486	>	}
4487	>	if ((index += baseSize) >= n)
4488	>	index = ++baseIndex;
4489	>	}
4490		}
4491	<	public boolean contains(Object o) {
4492	<	return ConcurrentHashMap.this.containsValue(o);
4491	>	}
4492	>
4493	>	/*
4494	>	* Task classes. Coded in a regular but ugly format/style to
4495	>	* simplify checks that each variant differs in the right way from
4496	>	* others. The null screenings exist because compilers cannot tell
4497	>	* that we've already null-checked task arguments, so we force
4498	>	* simplest hoisted bypass to help avoid convoluted traps.
4499	>	*/
4500	>
4501	>	static final class ForEachKeyTask<K,V>
4502	>	extends BulkTask<K,V,Void> {
4503	>	final Consumer<? super K> action;
4504	>	ForEachKeyTask
4505	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4506	>	Consumer<? super K> action) {
4507	>	super(p, b, i, f, t);
4508	>	this.action = action;
4509	>	}
4510	>	public final void compute() {
4511	>	final Consumer<? super K> action;
4512	>	if ((action = this.action) != null) {
4513	>	for (int i = baseIndex, f, h; batch > 0 &&
4514	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4515	>	addToPendingCount(1);
4516	>	new ForEachKeyTask<K,V>
4517	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4518	>	action).fork();
4519	>	}
4520	>	for (Node<K,V> p; (p = advance()) != null;)
4521	>	action.accept((K)p.key);
4522	>	propagateCompletion();
4523	>	}
4524		}
4525	<	public void clear() {
4526	<	ConcurrentHashMap.this.clear();
4525	>	}
4526	>
4527	>	static final class ForEachValueTask<K,V>
4528	>	extends BulkTask<K,V,Void> {
4529	>	final Consumer<? super V> action;
4530	>	ForEachValueTask
4531	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4532	>	Consumer<? super V> action) {
4533	>	super(p, b, i, f, t);
4534	>	this.action = action;
4535	>	}
4536	>	public final void compute() {
4537	>	final Consumer<? super V> action;
4538	>	if ((action = this.action) != null) {
4539	>	for (int i = baseIndex, f, h; batch > 0 &&
4540	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4541	>	addToPendingCount(1);
4542	>	new ForEachValueTask<K,V>
4543	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4544	>	action).fork();
4545	>	}
4546	>	for (Node<K,V> p; (p = advance()) != null;)
4547	>	action.accept(p.val);
4548	>	propagateCompletion();
4549	>	}
4550		}
4551		}
4552
4553	<	private class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4554	<	public Iterator<Map.Entry<K,V>> iterator() {
4555	<	return new EntryIterator();
4553	>	static final class ForEachEntryTask<K,V>
4554	>	extends BulkTask<K,V,Void> {
4555	>	final Consumer<? super Entry<K,V>> action;
4556	>	ForEachEntryTask
4557	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4558	>	Consumer<? super Entry<K,V>> action) {
4559	>	super(p, b, i, f, t);
4560	>	this.action = action;
4561	>	}
4562	>	public final void compute() {
4563	>	final Consumer<? super Entry<K,V>> action;
4564	>	if ((action = this.action) != null) {
4565	>	for (int i = baseIndex, f, h; batch > 0 &&
4566	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4567	>	addToPendingCount(1);
4568	>	new ForEachEntryTask<K,V>
4569	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4570	>	action).fork();
4571	>	}
4572	>	for (Node<K,V> p; (p = advance()) != null; )
4573	>	action.accept(p);
4574	>	propagateCompletion();
4575	>	}
4576		}
4577	<	public boolean contains(Object o) {
4578	<	if (!(o instanceof Map.Entry))
4579	<	return false;
4580	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4581	<	V v = ConcurrentHashMap.this.get(e.getKey());
4582	<	return v != null && v.equals(e.getValue());
4577	>	}
4578	>
4579	>	static final class ForEachMappingTask<K,V>
4580	>	extends BulkTask<K,V,Void> {
4581	>	final BiConsumer<? super K, ? super V> action;
4582	>	ForEachMappingTask
4583	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4584	>	BiConsumer<? super K,? super V> action) {
4585	>	super(p, b, i, f, t);
4586	>	this.action = action;
4587	>	}
4588	>	public final void compute() {
4589	>	final BiConsumer<? super K, ? super V> action;
4590	>	if ((action = this.action) != null) {
4591	>	for (int i = baseIndex, f, h; batch > 0 &&
4592	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4593	>	addToPendingCount(1);
4594	>	new ForEachMappingTask<K,V>
4595	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4596	>	action).fork();
4597	>	}
4598	>	for (Node<K,V> p; (p = advance()) != null; )
4599	>	action.accept((K)p.key, p.val);
4600	>	propagateCompletion();
4601	>	}
4602		}
4603	<	public boolean remove(Object o) {
4604	<	if (!(o instanceof Map.Entry))
4605	<	return false;
4606	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4607	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4603	>	}
4604	>
4605	>	static final class ForEachTransformedKeyTask<K,V,U>
4606	>	extends BulkTask<K,V,Void> {
4607	>	final Function<? super K, ? extends U> transformer;
4608	>	final Consumer<? super U> action;
4609	>	ForEachTransformedKeyTask
4610	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4611	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4612	>	super(p, b, i, f, t);
4613	>	this.transformer = transformer; this.action = action;
4614	>	}
4615	>	public final void compute() {
4616	>	final Function<? super K, ? extends U> transformer;
4617	>	final Consumer<? super U> action;
4618	>	if ((transformer = this.transformer) != null &&
4619	>	(action = this.action) != null) {
4620	>	for (int i = baseIndex, f, h; batch > 0 &&
4621	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4622	>	addToPendingCount(1);
4623	>	new ForEachTransformedKeyTask<K,V,U>
4624	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4625	>	transformer, action).fork();
4626	>	}
4627	>	for (Node<K,V> p; (p = advance()) != null; ) {
4628	>	U u;
4629	>	if ((u = transformer.apply((K)p.key)) != null)
4630	>	action.accept(u);
4631	>	}
4632	>	propagateCompletion();
4633	>	}
4634		}
4635	<	public int size() {
4636	<	return ConcurrentHashMap.this.size();
4635	>	}
4636	>
4637	>	static final class ForEachTransformedValueTask<K,V,U>
4638	>	extends BulkTask<K,V,Void> {
4639	>	final Function<? super V, ? extends U> transformer;
4640	>	final Consumer<? super U> action;
4641	>	ForEachTransformedValueTask
4642	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4643	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4644	>	super(p, b, i, f, t);
4645	>	this.transformer = transformer; this.action = action;
4646	>	}
4647	>	public final void compute() {
4648	>	final Function<? super V, ? extends U> transformer;
4649	>	final Consumer<? super U> action;
4650	>	if ((transformer = this.transformer) != null &&
4651	>	(action = this.action) != null) {
4652	>	for (int i = baseIndex, f, h; batch > 0 &&
4653	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4654	>	addToPendingCount(1);
4655	>	new ForEachTransformedValueTask<K,V,U>
4656	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4657	>	transformer, action).fork();
4658	>	}
4659	>	for (Node<K,V> p; (p = advance()) != null; ) {
4660	>	U u;
4661	>	if ((u = transformer.apply(p.val)) != null)
4662	>	action.accept(u);
4663	>	}
4664	>	propagateCompletion();
4665	>	}
4666		}
4667	<	public void clear() {
4668	<	ConcurrentHashMap.this.clear();
4667	>	}
4668	>
4669	>	static final class ForEachTransformedEntryTask<K,V,U>
4670	>	extends BulkTask<K,V,Void> {
4671	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4672	>	final Consumer<? super U> action;
4673	>	ForEachTransformedEntryTask
4674	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4675	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4676	>	super(p, b, i, f, t);
4677	>	this.transformer = transformer; this.action = action;
4678	>	}
4679	>	public final void compute() {
4680	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4681	>	final Consumer<? super U> action;
4682	>	if ((transformer = this.transformer) != null &&
4683	>	(action = this.action) != null) {
4684	>	for (int i = baseIndex, f, h; batch > 0 &&
4685	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4686	>	addToPendingCount(1);
4687	>	new ForEachTransformedEntryTask<K,V,U>
4688	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4689	>	transformer, action).fork();
4690	>	}
4691	>	for (Node<K,V> p; (p = advance()) != null; ) {
4692	>	U u;
4693	>	if ((u = transformer.apply(p)) != null)
4694	>	action.accept(u);
4695	>	}
4696	>	propagateCompletion();
4697	>	}
4698		}
4699	<	public Object[] toArray() {
4700	<	// Since we don't ordinarily have distinct Entry objects, we
4701	<	// must pack elements using exportable SimpleEntry
4702	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
4703	<	for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
4704	<	c.add(new SimpleEntry<K,V>(i.next()));
4705	<	return c.toArray();
4699	>	}
4700	>
4701	>	static final class ForEachTransformedMappingTask<K,V,U>
4702	>	extends BulkTask<K,V,Void> {
4703	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4704	>	final Consumer<? super U> action;
4705	>	ForEachTransformedMappingTask
4706	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4707	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4708	>	Consumer<? super U> action) {
4709	>	super(p, b, i, f, t);
4710	>	this.transformer = transformer; this.action = action;
4711	>	}
4712	>	public final void compute() {
4713	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4714	>	final Consumer<? super U> action;
4715	>	if ((transformer = this.transformer) != null &&
4716	>	(action = this.action) != null) {
4717	>	for (int i = baseIndex, f, h; batch > 0 &&
4718	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4719	>	addToPendingCount(1);
4720	>	new ForEachTransformedMappingTask<K,V,U>
4721	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4722	>	transformer, action).fork();
4723	>	}
4724	>	for (Node<K,V> p; (p = advance()) != null; ) {
4725	>	U u;
4726	>	if ((u = transformer.apply((K)p.key, p.val)) != null)
4727	>	action.accept(u);
4728	>	}
4729	>	propagateCompletion();
4730	>	}
4731		}
4732	<	public <T> T[] toArray(T[] a) {
4733	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
4734	<	for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
4735	<	c.add(new SimpleEntry<K,V>(i.next()));
4736	<	return c.toArray(a);
4732	>	}
4733	>
4734	>	static final class SearchKeysTask<K,V,U>
4735	>	extends BulkTask<K,V,U> {
4736	>	final Function<? super K, ? extends U> searchFunction;
4737	>	final AtomicReference<U> result;
4738	>	SearchKeysTask
4739	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4740	>	Function<? super K, ? extends U> searchFunction,
4741	>	AtomicReference<U> result) {
4742	>	super(p, b, i, f, t);
4743	>	this.searchFunction = searchFunction; this.result = result;
4744	>	}
4745	>	public final U getRawResult() { return result.get(); }
4746	>	public final void compute() {
4747	>	final Function<? super K, ? extends U> searchFunction;
4748	>	final AtomicReference<U> result;
4749	>	if ((searchFunction = this.searchFunction) != null &&
4750	>	(result = this.result) != null) {
4751	>	for (int i = baseIndex, f, h; batch > 0 &&
4752	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4753	>	if (result.get() != null)
4754	>	return;
4755	>	addToPendingCount(1);
4756	>	new SearchKeysTask<K,V,U>
4757	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4758	>	searchFunction, result).fork();
4759	>	}
4760	>	while (result.get() == null) {
4761	>	U u;
4762	>	Node<K,V> p;
4763	>	if ((p = advance()) == null) {
4764	>	propagateCompletion();
4765	>	break;
4766	>	}
4767	>	if ((u = searchFunction.apply((K)p.key)) != null) {
4768	>	if (result.compareAndSet(null, u))
4769	>	quietlyCompleteRoot();
4770	>	break;
4771	>	}
4772	>	}
4773	>	}
4774		}
4775	+	}
4776
4777	+	static final class SearchValuesTask<K,V,U>
4778	+	extends BulkTask<K,V,U> {
4779	+	final Function<? super V, ? extends U> searchFunction;
4780	+	final AtomicReference<U> result;
4781	+	SearchValuesTask
4782	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4783	+	Function<? super V, ? extends U> searchFunction,
4784	+	AtomicReference<U> result) {
4785	+	super(p, b, i, f, t);
4786	+	this.searchFunction = searchFunction; this.result = result;
4787	+	}
4788	+	public final U getRawResult() { return result.get(); }
4789	+	public final void compute() {
4790	+	final Function<? super V, ? extends U> searchFunction;
4791	+	final AtomicReference<U> result;
4792	+	if ((searchFunction = this.searchFunction) != null &&
4793	+	(result = this.result) != null) {
4794	+	for (int i = baseIndex, f, h; batch > 0 &&
4795	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4796	+	if (result.get() != null)
4797	+	return;
4798	+	addToPendingCount(1);
4799	+	new SearchValuesTask<K,V,U>
4800	+	(this, batch >>>= 1, baseLimit = h, f, tab,
4801	+	searchFunction, result).fork();
4802	+	}
4803	+	while (result.get() == null) {
4804	+	U u;
4805	+	Node<K,V> p;
4806	+	if ((p = advance()) == null) {
4807	+	propagateCompletion();
4808	+	break;
4809	+	}
4810	+	if ((u = searchFunction.apply(p.val)) != null) {
4811	+	if (result.compareAndSet(null, u))
4812	+	quietlyCompleteRoot();
4813	+	break;
4814	+	}
4815	+	}
4816	+	}
4817	+	}
4818		}
4819
4820	<	/**
4821	<	* This duplicates java.util.AbstractMap.SimpleEntry until this class
4822	<	* is made accessible.
4823	<	*/
4824	<	static class SimpleEntry<K,V> implements Entry<K,V> {
4825	<	K key;
4826	<	V value;
4820	>	static final class SearchEntriesTask<K,V,U>
4821	>	extends BulkTask<K,V,U> {
4822	>	final Function<Entry<K,V>, ? extends U> searchFunction;
4823	>	final AtomicReference<U> result;
4824	>	SearchEntriesTask
4825	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4826	>	Function<Entry<K,V>, ? extends U> searchFunction,
4827	>	AtomicReference<U> result) {
4828	>	super(p, b, i, f, t);
4829	>	this.searchFunction = searchFunction; this.result = result;
4830	>	}
4831	>	public final U getRawResult() { return result.get(); }
4832	>	public final void compute() {
4833	>	final Function<Entry<K,V>, ? extends U> searchFunction;
4834	>	final AtomicReference<U> result;
4835	>	if ((searchFunction = this.searchFunction) != null &&
4836	>	(result = this.result) != null) {
4837	>	for (int i = baseIndex, f, h; batch > 0 &&
4838	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4839	>	if (result.get() != null)
4840	>	return;
4841	>	addToPendingCount(1);
4842	>	new SearchEntriesTask<K,V,U>
4843	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4844	>	searchFunction, result).fork();
4845	>	}
4846	>	while (result.get() == null) {
4847	>	U u;
4848	>	Node<K,V> p;
4849	>	if ((p = advance()) == null) {
4850	>	propagateCompletion();
4851	>	break;
4852	>	}
4853	>	if ((u = searchFunction.apply(p)) != null) {
4854	>	if (result.compareAndSet(null, u))
4855	>	quietlyCompleteRoot();
4856	>	return;
4857	>	}
4858	>	}
4859	>	}
4860	>	}
4861	>	}
4862
4863	<	public SimpleEntry(K key, V value) {
4864	<	this.key   = key;
4865	<	this.value = value;
4866	<	}
4863	>	static final class SearchMappingsTask<K,V,U>
4864	>	extends BulkTask<K,V,U> {
4865	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
4866	>	final AtomicReference<U> result;
4867	>	SearchMappingsTask
4868	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4869	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
4870	>	AtomicReference<U> result) {
4871	>	super(p, b, i, f, t);
4872	>	this.searchFunction = searchFunction; this.result = result;
4873	>	}
4874	>	public final U getRawResult() { return result.get(); }
4875	>	public final void compute() {
4876	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
4877	>	final AtomicReference<U> result;
4878	>	if ((searchFunction = this.searchFunction) != null &&
4879	>	(result = this.result) != null) {
4880	>	for (int i = baseIndex, f, h; batch > 0 &&
4881	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4882	>	if (result.get() != null)
4883	>	return;
4884	>	addToPendingCount(1);
4885	>	new SearchMappingsTask<K,V,U>
4886	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4887	>	searchFunction, result).fork();
4888	>	}
4889	>	while (result.get() == null) {
4890	>	U u;
4891	>	Node<K,V> p;
4892	>	if ((p = advance()) == null) {
4893	>	propagateCompletion();
4894	>	break;
4895	>	}
4896	>	if ((u = searchFunction.apply((K)p.key, p.val)) != null) {
4897	>	if (result.compareAndSet(null, u))
4898	>	quietlyCompleteRoot();
4899	>	break;
4900	>	}
4901	>	}
4902	>	}
4903	>	}
4904	>	}
4905
4906	<	public SimpleEntry(Entry<K,V> e) {
4907	<	this.key   = e.getKey();
4908	<	this.value = e.getValue();
4909	<	}
4910	<
4911	<	public K getKey() {
4912	<	return key;
4913	<	}
4914	<
4915	<	public V getValue() {
4916	<	return value;
4917	<	}
4918	<
4919	<	public V setValue(V value) {
4920	<	V oldValue = this.value;
4921	<	this.value = value;
4922	<	return oldValue;
4923	<	}
4924	<
4925	<	public boolean equals(Object o) {
4926	<	if (!(o instanceof Map.Entry))
4927	<	return false;
4928	<	Map.Entry e = (Map.Entry)o;
4929	<	return eq(key, e.getKey()) && eq(value, e.getValue());
4930	<	}
4931	<
4932	<	public int hashCode() {
4933	<	return ((key   == null)   ? 0 :   key.hashCode()) ^
4934	<	((value == null)   ? 0 : value.hashCode());
4935	<	}
4936	<
4937	<	public String toString() {
4938	<	return key + "=" + value;
4939	<	}
4906	>	static final class ReduceKeysTask<K,V>
4907	>	extends BulkTask<K,V,K> {
4908	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
4909	>	K result;
4910	>	ReduceKeysTask<K,V> rights, nextRight;
4911	>	ReduceKeysTask
4912	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4913	>	ReduceKeysTask<K,V> nextRight,
4914	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
4915	>	super(p, b, i, f, t); this.nextRight = nextRight;
4916	>	this.reducer = reducer;
4917	>	}
4918	>	public final K getRawResult() { return result; }
4919	>	public final void compute() {
4920	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
4921	>	if ((reducer = this.reducer) != null) {
4922	>	for (int i = baseIndex, f, h; batch > 0 &&
4923	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4924	>	addToPendingCount(1);
4925	>	(rights = new ReduceKeysTask<K,V>
4926	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4927	>	rights, reducer)).fork();
4928	>	}
4929	>	K r = null;
4930	>	for (Node<K,V> p; (p = advance()) != null; ) {
4931	>	K u = (K)p.key;
4932	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
4933	>	}
4934	>	result = r;
4935	>	CountedCompleter<?> c;
4936	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
4937	>	ReduceKeysTask<K,V>
4938	>	t = (ReduceKeysTask<K,V>)c,
4939	>	s = t.rights;
4940	>	while (s != null) {
4941	>	K tr, sr;
4942	>	if ((sr = s.result) != null)
4943	>	t.result = (((tr = t.result) == null) ? sr :
4944	>	reducer.apply(tr, sr));
4945	>	s = t.rights = s.nextRight;
4946	>	}
4947	>	}
4948	>	}
4949	>	}
4950	>	}
4951
4952	<	private static boolean eq(Object o1, Object o2) {
4953	<	return (o1 == null ? o2 == null : o1.equals(o2));
4952	>	static final class ReduceValuesTask<K,V>
4953	>	extends BulkTask<K,V,V> {
4954	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
4955	>	V result;
4956	>	ReduceValuesTask<K,V> rights, nextRight;
4957	>	ReduceValuesTask
4958	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4959	>	ReduceValuesTask<K,V> nextRight,
4960	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4961	>	super(p, b, i, f, t); this.nextRight = nextRight;
4962	>	this.reducer = reducer;
4963	>	}
4964	>	public final V getRawResult() { return result; }
4965	>	public final void compute() {
4966	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
4967	>	if ((reducer = this.reducer) != null) {
4968	>	for (int i = baseIndex, f, h; batch > 0 &&
4969	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4970	>	addToPendingCount(1);
4971	>	(rights = new ReduceValuesTask<K,V>
4972	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4973	>	rights, reducer)).fork();
4974	>	}
4975	>	V r = null;
4976	>	for (Node<K,V> p; (p = advance()) != null; ) {
4977	>	V v = p.val;
4978	>	r = (r == null) ? v : reducer.apply(r, v);
4979	>	}
4980	>	result = r;
4981	>	CountedCompleter<?> c;
4982	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
4983	>	ReduceValuesTask<K,V>
4984	>	t = (ReduceValuesTask<K,V>)c,
4985	>	s = t.rights;
4986	>	while (s != null) {
4987	>	V tr, sr;
4988	>	if ((sr = s.result) != null)
4989	>	t.result = (((tr = t.result) == null) ? sr :
4990	>	reducer.apply(tr, sr));
4991	>	s = t.rights = s.nextRight;
4992	>	}
4993	>	}
4994	>	}
4995		}
4996		}
4997
4998	<	/* ---------------- Serialization Support -------------- */
4998	>	static final class ReduceEntriesTask<K,V>
4999	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5000	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5001	>	Map.Entry<K,V> result;
5002	>	ReduceEntriesTask<K,V> rights, nextRight;
5003	>	ReduceEntriesTask
5004	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5005	>	ReduceEntriesTask<K,V> nextRight,
5006	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5007	>	super(p, b, i, f, t); this.nextRight = nextRight;
5008	>	this.reducer = reducer;
5009	>	}
5010	>	public final Map.Entry<K,V> getRawResult() { return result; }
5011	>	public final void compute() {
5012	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5013	>	if ((reducer = this.reducer) != null) {
5014	>	for (int i = baseIndex, f, h; batch > 0 &&
5015	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5016	>	addToPendingCount(1);
5017	>	(rights = new ReduceEntriesTask<K,V>
5018	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5019	>	rights, reducer)).fork();
5020	>	}
5021	>	Map.Entry<K,V> r = null;
5022	>	for (Node<K,V> p; (p = advance()) != null; )
5023	>	r = (r == null) ? p : reducer.apply(r, p);
5024	>	result = r;
5025	>	CountedCompleter<?> c;
5026	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5027	>	ReduceEntriesTask<K,V>
5028	>	t = (ReduceEntriesTask<K,V>)c,
5029	>	s = t.rights;
5030	>	while (s != null) {
5031	>	Map.Entry<K,V> tr, sr;
5032	>	if ((sr = s.result) != null)
5033	>	t.result = (((tr = t.result) == null) ? sr :
5034	>	reducer.apply(tr, sr));
5035	>	s = t.rights = s.nextRight;
5036	>	}
5037	>	}
5038	>	}
5039	>	}
5040	>	}
5041
5042	<	/**
5043	<	* Save the state of the <tt>ConcurrentHashMap</tt>
5044	<	* instance to a stream (i.e.,
5045	<	* serialize it).
5046	<	* @param s the stream
5047	<	* @serialData
5048	<	* the key (Object) and value (Object)
5049	<	* for each key-value mapping, followed by a null pair.
5050	<	* The key-value mappings are emitted in no particular order.
5051	<	*/
5052	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
5053	<	s.defaultWriteObject();
5042	>	static final class MapReduceKeysTask<K,V,U>
5043	>	extends BulkTask<K,V,U> {
5044	>	final Function<? super K, ? extends U> transformer;
5045	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5046	>	U result;
5047	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5048	>	MapReduceKeysTask
5049	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5050	>	MapReduceKeysTask<K,V,U> nextRight,
5051	>	Function<? super K, ? extends U> transformer,
5052	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5053	>	super(p, b, i, f, t); this.nextRight = nextRight;
5054	>	this.transformer = transformer;
5055	>	this.reducer = reducer;
5056	>	}
5057	>	public final U getRawResult() { return result; }
5058	>	public final void compute() {
5059	>	final Function<? super K, ? extends U> transformer;
5060	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5061	>	if ((transformer = this.transformer) != null &&
5062	>	(reducer = this.reducer) != null) {
5063	>	for (int i = baseIndex, f, h; batch > 0 &&
5064	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5065	>	addToPendingCount(1);
5066	>	(rights = new MapReduceKeysTask<K,V,U>
5067	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5068	>	rights, transformer, reducer)).fork();
5069	>	}
5070	>	U r = null;
5071	>	for (Node<K,V> p; (p = advance()) != null; ) {
5072	>	U u;
5073	>	if ((u = transformer.apply((K)p.key)) != null)
5074	>	r = (r == null) ? u : reducer.apply(r, u);
5075	>	}
5076	>	result = r;
5077	>	CountedCompleter<?> c;
5078	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5079	>	MapReduceKeysTask<K,V,U>
5080	>	t = (MapReduceKeysTask<K,V,U>)c,
5081	>	s = t.rights;
5082	>	while (s != null) {
5083	>	U tr, sr;
5084	>	if ((sr = s.result) != null)
5085	>	t.result = (((tr = t.result) == null) ? sr :
5086	>	reducer.apply(tr, sr));
5087	>	s = t.rights = s.nextRight;
5088	>	}
5089	>	}
5090	>	}
5091	>	}
5092	>	}
5093
5094	<	for (int k = 0; k < segments.length; ++k) {
5095	<	Segment<K,V> seg = (Segment<K,V>)segments[k];
5096	<	seg.lock();
5097	<	try {
5098	<	HashEntry[] tab = seg.table;
5099	<	for (int i = 0; i < tab.length; ++i) {
5100	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
5101	<	s.writeObject(e.key);
5102	<	s.writeObject(e.value);
5094	>	static final class MapReduceValuesTask<K,V,U>
5095	>	extends BulkTask<K,V,U> {
5096	>	final Function<? super V, ? extends U> transformer;
5097	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5098	>	U result;
5099	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5100	>	MapReduceValuesTask
5101	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5102	>	MapReduceValuesTask<K,V,U> nextRight,
5103	>	Function<? super V, ? extends U> transformer,
5104	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5105	>	super(p, b, i, f, t); this.nextRight = nextRight;
5106	>	this.transformer = transformer;
5107	>	this.reducer = reducer;
5108	>	}
5109	>	public final U getRawResult() { return result; }
5110	>	public final void compute() {
5111	>	final Function<? super V, ? extends U> transformer;
5112	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5113	>	if ((transformer = this.transformer) != null &&
5114	>	(reducer = this.reducer) != null) {
5115	>	for (int i = baseIndex, f, h; batch > 0 &&
5116	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5117	>	addToPendingCount(1);
5118	>	(rights = new MapReduceValuesTask<K,V,U>
5119	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5120	>	rights, transformer, reducer)).fork();
5121	>	}
5122	>	U r = null;
5123	>	for (Node<K,V> p; (p = advance()) != null; ) {
5124	>	U u;
5125	>	if ((u = transformer.apply(p.val)) != null)
5126	>	r = (r == null) ? u : reducer.apply(r, u);
5127	>	}
5128	>	result = r;
5129	>	CountedCompleter<?> c;
5130	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5131	>	MapReduceValuesTask<K,V,U>
5132	>	t = (MapReduceValuesTask<K,V,U>)c,
5133	>	s = t.rights;
5134	>	while (s != null) {
5135	>	U tr, sr;
5136	>	if ((sr = s.result) != null)
5137	>	t.result = (((tr = t.result) == null) ? sr :
5138	>	reducer.apply(tr, sr));
5139	>	s = t.rights = s.nextRight;
5140		}
5141		}
1297	–	} finally {
1298	–	seg.unlock();
5142		}
5143		}
1301	–	s.writeObject(null);
1302	–	s.writeObject(null);
5144		}
5145
5146	<	/**
5147	<	* Reconstitute the <tt>ConcurrentHashMap</tt>
5148	<	* instance from a stream (i.e.,
5149	<	* deserialize it).
5150	<	* @param s the stream
5151	<	*/
5152	<	private void readObject(java.io.ObjectInputStream s)
5153	<	throws IOException, ClassNotFoundException  {
5154	<	s.defaultReadObject();
5146	>	static final class MapReduceEntriesTask<K,V,U>
5147	>	extends BulkTask<K,V,U> {
5148	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5149	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5150	>	U result;
5151	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5152	>	MapReduceEntriesTask
5153	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5154	>	MapReduceEntriesTask<K,V,U> nextRight,
5155	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5156	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5157	>	super(p, b, i, f, t); this.nextRight = nextRight;
5158	>	this.transformer = transformer;
5159	>	this.reducer = reducer;
5160	>	}
5161	>	public final U getRawResult() { return result; }
5162	>	public final void compute() {
5163	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5164	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5165	>	if ((transformer = this.transformer) != null &&
5166	>	(reducer = this.reducer) != null) {
5167	>	for (int i = baseIndex, f, h; batch > 0 &&
5168	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5169	>	addToPendingCount(1);
5170	>	(rights = new MapReduceEntriesTask<K,V,U>
5171	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5172	>	rights, transformer, reducer)).fork();
5173	>	}
5174	>	U r = null;
5175	>	for (Node<K,V> p; (p = advance()) != null; ) {
5176	>	U u;
5177	>	if ((u = transformer.apply(p)) != null)
5178	>	r = (r == null) ? u : reducer.apply(r, u);
5179	>	}
5180	>	result = r;
5181	>	CountedCompleter<?> c;
5182	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5183	>	MapReduceEntriesTask<K,V,U>
5184	>	t = (MapReduceEntriesTask<K,V,U>)c,
5185	>	s = t.rights;
5186	>	while (s != null) {
5187	>	U tr, sr;
5188	>	if ((sr = s.result) != null)
5189	>	t.result = (((tr = t.result) == null) ? sr :
5190	>	reducer.apply(tr, sr));
5191	>	s = t.rights = s.nextRight;
5192	>	}
5193	>	}
5194	>	}
5195	>	}
5196	>	}
5197
5198	<	// Initialize each segment to be minimally sized, and let grow.
5199	<	for (int i = 0; i < segments.length; ++i) {
5200	<	segments[i].setTable(new HashEntry[1]);
5198	>	static final class MapReduceMappingsTask<K,V,U>
5199	>	extends BulkTask<K,V,U> {
5200	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5201	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5202	>	U result;
5203	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5204	>	MapReduceMappingsTask
5205	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5206	>	MapReduceMappingsTask<K,V,U> nextRight,
5207	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5208	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5209	>	super(p, b, i, f, t); this.nextRight = nextRight;
5210	>	this.transformer = transformer;
5211	>	this.reducer = reducer;
5212	>	}
5213	>	public final U getRawResult() { return result; }
5214	>	public final void compute() {
5215	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5216	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5217	>	if ((transformer = this.transformer) != null &&
5218	>	(reducer = this.reducer) != null) {
5219	>	for (int i = baseIndex, f, h; batch > 0 &&
5220	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5221	>	addToPendingCount(1);
5222	>	(rights = new MapReduceMappingsTask<K,V,U>
5223	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5224	>	rights, transformer, reducer)).fork();
5225	>	}
5226	>	U r = null;
5227	>	for (Node<K,V> p; (p = advance()) != null; ) {
5228	>	U u;
5229	>	if ((u = transformer.apply((K)p.key, p.val)) != null)
5230	>	r = (r == null) ? u : reducer.apply(r, u);
5231	>	}
5232	>	result = r;
5233	>	CountedCompleter<?> c;
5234	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5235	>	MapReduceMappingsTask<K,V,U>
5236	>	t = (MapReduceMappingsTask<K,V,U>)c,
5237	>	s = t.rights;
5238	>	while (s != null) {
5239	>	U tr, sr;
5240	>	if ((sr = s.result) != null)
5241	>	t.result = (((tr = t.result) == null) ? sr :
5242	>	reducer.apply(tr, sr));
5243	>	s = t.rights = s.nextRight;
5244	>	}
5245	>	}
5246	>	}
5247		}
5248	+	}
5249
5250	<	// Read the keys and values, and put the mappings in the table
5251	<	for (;;) {
5252	<	K key = (K) s.readObject();
5253	<	V value = (V) s.readObject();
5254	<	if (key == null)
5255	<	break;
5256	<	put(key, value);
5250	>	static final class MapReduceKeysToDoubleTask<K,V>
5251	>	extends BulkTask<K,V,Double> {
5252	>	final ToDoubleFunction<? super K> transformer;
5253	>	final DoubleBinaryOperator reducer;
5254	>	final double basis;
5255	>	double result;
5256	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5257	>	MapReduceKeysToDoubleTask
5258	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5259	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5260	>	ToDoubleFunction<? super K> transformer,
5261	>	double basis,
5262	>	DoubleBinaryOperator reducer) {
5263	>	super(p, b, i, f, t); this.nextRight = nextRight;
5264	>	this.transformer = transformer;
5265	>	this.basis = basis; this.reducer = reducer;
5266	>	}
5267	>	public final Double getRawResult() { return result; }
5268	>	public final void compute() {
5269	>	final ToDoubleFunction<? super K> transformer;
5270	>	final DoubleBinaryOperator reducer;
5271	>	if ((transformer = this.transformer) != null &&
5272	>	(reducer = this.reducer) != null) {
5273	>	double r = this.basis;
5274	>	for (int i = baseIndex, f, h; batch > 0 &&
5275	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5276	>	addToPendingCount(1);
5277	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5278	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5279	>	rights, transformer, r, reducer)).fork();
5280	>	}
5281	>	for (Node<K,V> p; (p = advance()) != null; )
5282	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)p.key));
5283	>	result = r;
5284	>	CountedCompleter<?> c;
5285	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5286	>	MapReduceKeysToDoubleTask<K,V>
5287	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5288	>	s = t.rights;
5289	>	while (s != null) {
5290	>	t.result = reducer.applyAsDouble(t.result, s.result);
5291	>	s = t.rights = s.nextRight;
5292	>	}
5293	>	}
5294	>	}
5295	>	}
5296	>	}
5297	>
5298	>	static final class MapReduceValuesToDoubleTask<K,V>
5299	>	extends BulkTask<K,V,Double> {
5300	>	final ToDoubleFunction<? super V> transformer;
5301	>	final DoubleBinaryOperator reducer;
5302	>	final double basis;
5303	>	double result;
5304	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5305	>	MapReduceValuesToDoubleTask
5306	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5307	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5308	>	ToDoubleFunction<? super V> transformer,
5309	>	double basis,
5310	>	DoubleBinaryOperator reducer) {
5311	>	super(p, b, i, f, t); this.nextRight = nextRight;
5312	>	this.transformer = transformer;
5313	>	this.basis = basis; this.reducer = reducer;
5314	>	}
5315	>	public final Double getRawResult() { return result; }
5316	>	public final void compute() {
5317	>	final ToDoubleFunction<? super V> transformer;
5318	>	final DoubleBinaryOperator reducer;
5319	>	if ((transformer = this.transformer) != null &&
5320	>	(reducer = this.reducer) != null) {
5321	>	double r = this.basis;
5322	>	for (int i = baseIndex, f, h; batch > 0 &&
5323	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5324	>	addToPendingCount(1);
5325	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5326	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5327	>	rights, transformer, r, reducer)).fork();
5328	>	}
5329	>	for (Node<K,V> p; (p = advance()) != null; )
5330	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5331	>	result = r;
5332	>	CountedCompleter<?> c;
5333	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5334	>	MapReduceValuesToDoubleTask<K,V>
5335	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5336	>	s = t.rights;
5337	>	while (s != null) {
5338	>	t.result = reducer.applyAsDouble(t.result, s.result);
5339	>	s = t.rights = s.nextRight;
5340	>	}
5341	>	}
5342	>	}
5343	>	}
5344	>	}
5345	>
5346	>	static final class MapReduceEntriesToDoubleTask<K,V>
5347	>	extends BulkTask<K,V,Double> {
5348	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5349	>	final DoubleBinaryOperator reducer;
5350	>	final double basis;
5351	>	double result;
5352	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5353	>	MapReduceEntriesToDoubleTask
5354	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5355	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5356	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5357	>	double basis,
5358	>	DoubleBinaryOperator reducer) {
5359	>	super(p, b, i, f, t); this.nextRight = nextRight;
5360	>	this.transformer = transformer;
5361	>	this.basis = basis; this.reducer = reducer;
5362	>	}
5363	>	public final Double getRawResult() { return result; }
5364	>	public final void compute() {
5365	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5366	>	final DoubleBinaryOperator reducer;
5367	>	if ((transformer = this.transformer) != null &&
5368	>	(reducer = this.reducer) != null) {
5369	>	double r = this.basis;
5370	>	for (int i = baseIndex, f, h; batch > 0 &&
5371	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5372	>	addToPendingCount(1);
5373	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5374	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5375	>	rights, transformer, r, reducer)).fork();
5376	>	}
5377	>	for (Node<K,V> p; (p = advance()) != null; )
5378	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5379	>	result = r;
5380	>	CountedCompleter<?> c;
5381	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5382	>	MapReduceEntriesToDoubleTask<K,V>
5383	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5384	>	s = t.rights;
5385	>	while (s != null) {
5386	>	t.result = reducer.applyAsDouble(t.result, s.result);
5387	>	s = t.rights = s.nextRight;
5388	>	}
5389	>	}
5390	>	}
5391	>	}
5392	>	}
5393	>
5394	>	static final class MapReduceMappingsToDoubleTask<K,V>
5395	>	extends BulkTask<K,V,Double> {
5396	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5397	>	final DoubleBinaryOperator reducer;
5398	>	final double basis;
5399	>	double result;
5400	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5401	>	MapReduceMappingsToDoubleTask
5402	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5403	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5404	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5405	>	double basis,
5406	>	DoubleBinaryOperator reducer) {
5407	>	super(p, b, i, f, t); this.nextRight = nextRight;
5408	>	this.transformer = transformer;
5409	>	this.basis = basis; this.reducer = reducer;
5410	>	}
5411	>	public final Double getRawResult() { return result; }
5412	>	public final void compute() {
5413	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5414	>	final DoubleBinaryOperator reducer;
5415	>	if ((transformer = this.transformer) != null &&
5416	>	(reducer = this.reducer) != null) {
5417	>	double r = this.basis;
5418	>	for (int i = baseIndex, f, h; batch > 0 &&
5419	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5420	>	addToPendingCount(1);
5421	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5422	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5423	>	rights, transformer, r, reducer)).fork();
5424	>	}
5425	>	for (Node<K,V> p; (p = advance()) != null; )
5426	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble((K)p.key, p.val));
5427	>	result = r;
5428	>	CountedCompleter<?> c;
5429	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5430	>	MapReduceMappingsToDoubleTask<K,V>
5431	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5432	>	s = t.rights;
5433	>	while (s != null) {
5434	>	t.result = reducer.applyAsDouble(t.result, s.result);
5435	>	s = t.rights = s.nextRight;
5436	>	}
5437	>	}
5438	>	}
5439	>	}
5440	>	}
5441	>
5442	>	static final class MapReduceKeysToLongTask<K,V>
5443	>	extends BulkTask<K,V,Long> {
5444	>	final ToLongFunction<? super K> transformer;
5445	>	final LongBinaryOperator reducer;
5446	>	final long basis;
5447	>	long result;
5448	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5449	>	MapReduceKeysToLongTask
5450	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5451	>	MapReduceKeysToLongTask<K,V> nextRight,
5452	>	ToLongFunction<? super K> transformer,
5453	>	long basis,
5454	>	LongBinaryOperator reducer) {
5455	>	super(p, b, i, f, t); this.nextRight = nextRight;
5456	>	this.transformer = transformer;
5457	>	this.basis = basis; this.reducer = reducer;
5458	>	}
5459	>	public final Long getRawResult() { return result; }
5460	>	public final void compute() {
5461	>	final ToLongFunction<? super K> transformer;
5462	>	final LongBinaryOperator reducer;
5463	>	if ((transformer = this.transformer) != null &&
5464	>	(reducer = this.reducer) != null) {
5465	>	long r = this.basis;
5466	>	for (int i = baseIndex, f, h; batch > 0 &&
5467	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5468	>	addToPendingCount(1);
5469	>	(rights = new MapReduceKeysToLongTask<K,V>
5470	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5471	>	rights, transformer, r, reducer)).fork();
5472	>	}
5473	>	for (Node<K,V> p; (p = advance()) != null; )
5474	>	r = reducer.applyAsLong(r, transformer.applyAsLong((K)p.key));
5475	>	result = r;
5476	>	CountedCompleter<?> c;
5477	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5478	>	MapReduceKeysToLongTask<K,V>
5479	>	t = (MapReduceKeysToLongTask<K,V>)c,
5480	>	s = t.rights;
5481	>	while (s != null) {
5482	>	t.result = reducer.applyAsLong(t.result, s.result);
5483	>	s = t.rights = s.nextRight;
5484	>	}
5485	>	}
5486	>	}
5487	>	}
5488	>	}
5489	>
5490	>	static final class MapReduceValuesToLongTask<K,V>
5491	>	extends BulkTask<K,V,Long> {
5492	>	final ToLongFunction<? super V> transformer;
5493	>	final LongBinaryOperator reducer;
5494	>	final long basis;
5495	>	long result;
5496	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5497	>	MapReduceValuesToLongTask
5498	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5499	>	MapReduceValuesToLongTask<K,V> nextRight,
5500	>	ToLongFunction<? super V> transformer,
5501	>	long basis,
5502	>	LongBinaryOperator reducer) {
5503	>	super(p, b, i, f, t); this.nextRight = nextRight;
5504	>	this.transformer = transformer;
5505	>	this.basis = basis; this.reducer = reducer;
5506	>	}
5507	>	public final Long getRawResult() { return result; }
5508	>	public final void compute() {
5509	>	final ToLongFunction<? super V> transformer;
5510	>	final LongBinaryOperator reducer;
5511	>	if ((transformer = this.transformer) != null &&
5512	>	(reducer = this.reducer) != null) {
5513	>	long r = this.basis;
5514	>	for (int i = baseIndex, f, h; batch > 0 &&
5515	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5516	>	addToPendingCount(1);
5517	>	(rights = new MapReduceValuesToLongTask<K,V>
5518	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5519	>	rights, transformer, r, reducer)).fork();
5520	>	}
5521	>	for (Node<K,V> p; (p = advance()) != null; )
5522	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5523	>	result = r;
5524	>	CountedCompleter<?> c;
5525	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5526	>	MapReduceValuesToLongTask<K,V>
5527	>	t = (MapReduceValuesToLongTask<K,V>)c,
5528	>	s = t.rights;
5529	>	while (s != null) {
5530	>	t.result = reducer.applyAsLong(t.result, s.result);
5531	>	s = t.rights = s.nextRight;
5532	>	}
5533	>	}
5534	>	}
5535	>	}
5536	>	}
5537	>
5538	>	static final class MapReduceEntriesToLongTask<K,V>
5539	>	extends BulkTask<K,V,Long> {
5540	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5541	>	final LongBinaryOperator reducer;
5542	>	final long basis;
5543	>	long result;
5544	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5545	>	MapReduceEntriesToLongTask
5546	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5547	>	MapReduceEntriesToLongTask<K,V> nextRight,
5548	>	ToLongFunction<Map.Entry<K,V>> transformer,
5549	>	long basis,
5550	>	LongBinaryOperator reducer) {
5551	>	super(p, b, i, f, t); this.nextRight = nextRight;
5552	>	this.transformer = transformer;
5553	>	this.basis = basis; this.reducer = reducer;
5554	>	}
5555	>	public final Long getRawResult() { return result; }
5556	>	public final void compute() {
5557	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5558	>	final LongBinaryOperator reducer;
5559	>	if ((transformer = this.transformer) != null &&
5560	>	(reducer = this.reducer) != null) {
5561	>	long r = this.basis;
5562	>	for (int i = baseIndex, f, h; batch > 0 &&
5563	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5564	>	addToPendingCount(1);
5565	>	(rights = new MapReduceEntriesToLongTask<K,V>
5566	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5567	>	rights, transformer, r, reducer)).fork();
5568	>	}
5569	>	for (Node<K,V> p; (p = advance()) != null; )
5570	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5571	>	result = r;
5572	>	CountedCompleter<?> c;
5573	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5574	>	MapReduceEntriesToLongTask<K,V>
5575	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5576	>	s = t.rights;
5577	>	while (s != null) {
5578	>	t.result = reducer.applyAsLong(t.result, s.result);
5579	>	s = t.rights = s.nextRight;
5580	>	}
5581	>	}
5582	>	}
5583		}
5584		}
1329	–	}
5585
5586	+	static final class MapReduceMappingsToLongTask<K,V>
5587	+	extends BulkTask<K,V,Long> {
5588	+	final ToLongBiFunction<? super K, ? super V> transformer;
5589	+	final LongBinaryOperator reducer;
5590	+	final long basis;
5591	+	long result;
5592	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5593	+	MapReduceMappingsToLongTask
5594	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5595	+	MapReduceMappingsToLongTask<K,V> nextRight,
5596	+	ToLongBiFunction<? super K, ? super V> transformer,
5597	+	long basis,
5598	+	LongBinaryOperator reducer) {
5599	+	super(p, b, i, f, t); this.nextRight = nextRight;
5600	+	this.transformer = transformer;
5601	+	this.basis = basis; this.reducer = reducer;
5602	+	}
5603	+	public final Long getRawResult() { return result; }
5604	+	public final void compute() {
5605	+	final ToLongBiFunction<? super K, ? super V> transformer;
5606	+	final LongBinaryOperator reducer;
5607	+	if ((transformer = this.transformer) != null &&
5608	+	(reducer = this.reducer) != null) {
5609	+	long r = this.basis;
5610	+	for (int i = baseIndex, f, h; batch > 0 &&
5611	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5612	+	addToPendingCount(1);
5613	+	(rights = new MapReduceMappingsToLongTask<K,V>
5614	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5615	+	rights, transformer, r, reducer)).fork();
5616	+	}
5617	+	for (Node<K,V> p; (p = advance()) != null; )
5618	+	r = reducer.applyAsLong(r, transformer.applyAsLong((K)p.key, p.val));
5619	+	result = r;
5620	+	CountedCompleter<?> c;
5621	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5622	+	MapReduceMappingsToLongTask<K,V>
5623	+	t = (MapReduceMappingsToLongTask<K,V>)c,
5624	+	s = t.rights;
5625	+	while (s != null) {
5626	+	t.result = reducer.applyAsLong(t.result, s.result);
5627	+	s = t.rights = s.nextRight;
5628	+	}
5629	+	}
5630	+	}
5631	+	}
5632	+	}
5633	+
5634	+	static final class MapReduceKeysToIntTask<K,V>
5635	+	extends BulkTask<K,V,Integer> {
5636	+	final ToIntFunction<? super K> transformer;
5637	+	final IntBinaryOperator reducer;
5638	+	final int basis;
5639	+	int result;
5640	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
5641	+	MapReduceKeysToIntTask
5642	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5643	+	MapReduceKeysToIntTask<K,V> nextRight,
5644	+	ToIntFunction<? super K> transformer,
5645	+	int basis,
5646	+	IntBinaryOperator reducer) {
5647	+	super(p, b, i, f, t); this.nextRight = nextRight;
5648	+	this.transformer = transformer;
5649	+	this.basis = basis; this.reducer = reducer;
5650	+	}
5651	+	public final Integer getRawResult() { return result; }
5652	+	public final void compute() {
5653	+	final ToIntFunction<? super K> transformer;
5654	+	final IntBinaryOperator reducer;
5655	+	if ((transformer = this.transformer) != null &&
5656	+	(reducer = this.reducer) != null) {
5657	+	int r = this.basis;
5658	+	for (int i = baseIndex, f, h; batch > 0 &&
5659	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5660	+	addToPendingCount(1);
5661	+	(rights = new MapReduceKeysToIntTask<K,V>
5662	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5663	+	rights, transformer, r, reducer)).fork();
5664	+	}
5665	+	for (Node<K,V> p; (p = advance()) != null; )
5666	+	r = reducer.applyAsInt(r, transformer.applyAsInt((K)p.key));
5667	+	result = r;
5668	+	CountedCompleter<?> c;
5669	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5670	+	MapReduceKeysToIntTask<K,V>
5671	+	t = (MapReduceKeysToIntTask<K,V>)c,
5672	+	s = t.rights;
5673	+	while (s != null) {
5674	+	t.result = reducer.applyAsInt(t.result, s.result);
5675	+	s = t.rights = s.nextRight;
5676	+	}
5677	+	}
5678	+	}
5679	+	}
5680	+	}
5681	+
5682	+	static final class MapReduceValuesToIntTask<K,V>
5683	+	extends BulkTask<K,V,Integer> {
5684	+	final ToIntFunction<? super V> transformer;
5685	+	final IntBinaryOperator reducer;
5686	+	final int basis;
5687	+	int result;
5688	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
5689	+	MapReduceValuesToIntTask
5690	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5691	+	MapReduceValuesToIntTask<K,V> nextRight,
5692	+	ToIntFunction<? super V> transformer,
5693	+	int basis,
5694	+	IntBinaryOperator reducer) {
5695	+	super(p, b, i, f, t); this.nextRight = nextRight;
5696	+	this.transformer = transformer;
5697	+	this.basis = basis; this.reducer = reducer;
5698	+	}
5699	+	public final Integer getRawResult() { return result; }
5700	+	public final void compute() {
5701	+	final ToIntFunction<? super V> transformer;
5702	+	final IntBinaryOperator reducer;
5703	+	if ((transformer = this.transformer) != null &&
5704	+	(reducer = this.reducer) != null) {
5705	+	int r = this.basis;
5706	+	for (int i = baseIndex, f, h; batch > 0 &&
5707	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5708	+	addToPendingCount(1);
5709	+	(rights = new MapReduceValuesToIntTask<K,V>
5710	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5711	+	rights, transformer, r, reducer)).fork();
5712	+	}
5713	+	for (Node<K,V> p; (p = advance()) != null; )
5714	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5715	+	result = r;
5716	+	CountedCompleter<?> c;
5717	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5718	+	MapReduceValuesToIntTask<K,V>
5719	+	t = (MapReduceValuesToIntTask<K,V>)c,
5720	+	s = t.rights;
5721	+	while (s != null) {
5722	+	t.result = reducer.applyAsInt(t.result, s.result);
5723	+	s = t.rights = s.nextRight;
5724	+	}
5725	+	}
5726	+	}
5727	+	}
5728	+	}
5729	+
5730	+	static final class MapReduceEntriesToIntTask<K,V>
5731	+	extends BulkTask<K,V,Integer> {
5732	+	final ToIntFunction<Map.Entry<K,V>> transformer;
5733	+	final IntBinaryOperator reducer;
5734	+	final int basis;
5735	+	int result;
5736	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5737	+	MapReduceEntriesToIntTask
5738	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5739	+	MapReduceEntriesToIntTask<K,V> nextRight,
5740	+	ToIntFunction<Map.Entry<K,V>> transformer,
5741	+	int basis,
5742	+	IntBinaryOperator reducer) {
5743	+	super(p, b, i, f, t); this.nextRight = nextRight;
5744	+	this.transformer = transformer;
5745	+	this.basis = basis; this.reducer = reducer;
5746	+	}
5747	+	public final Integer getRawResult() { return result; }
5748	+	public final void compute() {
5749	+	final ToIntFunction<Map.Entry<K,V>> transformer;
5750	+	final IntBinaryOperator reducer;
5751	+	if ((transformer = this.transformer) != null &&
5752	+	(reducer = this.reducer) != null) {
5753	+	int r = this.basis;
5754	+	for (int i = baseIndex, f, h; batch > 0 &&
5755	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5756	+	addToPendingCount(1);
5757	+	(rights = new MapReduceEntriesToIntTask<K,V>
5758	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5759	+	rights, transformer, r, reducer)).fork();
5760	+	}
5761	+	for (Node<K,V> p; (p = advance()) != null; )
5762	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
5763	+	result = r;
5764	+	CountedCompleter<?> c;
5765	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5766	+	MapReduceEntriesToIntTask<K,V>
5767	+	t = (MapReduceEntriesToIntTask<K,V>)c,
5768	+	s = t.rights;
5769	+	while (s != null) {
5770	+	t.result = reducer.applyAsInt(t.result, s.result);
5771	+	s = t.rights = s.nextRight;
5772	+	}
5773	+	}
5774	+	}
5775	+	}
5776	+	}
5777	+
5778	+	static final class MapReduceMappingsToIntTask<K,V>
5779	+	extends BulkTask<K,V,Integer> {
5780	+	final ToIntBiFunction<? super K, ? super V> transformer;
5781	+	final IntBinaryOperator reducer;
5782	+	final int basis;
5783	+	int result;
5784	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
5785	+	MapReduceMappingsToIntTask
5786	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5787	+	MapReduceMappingsToIntTask<K,V> nextRight,
5788	+	ToIntBiFunction<? super K, ? super V> transformer,
5789	+	int basis,
5790	+	IntBinaryOperator reducer) {
5791	+	super(p, b, i, f, t); this.nextRight = nextRight;
5792	+	this.transformer = transformer;
5793	+	this.basis = basis; this.reducer = reducer;
5794	+	}
5795	+	public final Integer getRawResult() { return result; }
5796	+	public final void compute() {
5797	+	final ToIntBiFunction<? super K, ? super V> transformer;
5798	+	final IntBinaryOperator reducer;
5799	+	if ((transformer = this.transformer) != null &&
5800	+	(reducer = this.reducer) != null) {
5801	+	int r = this.basis;
5802	+	for (int i = baseIndex, f, h; batch > 0 &&
5803	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5804	+	addToPendingCount(1);
5805	+	(rights = new MapReduceMappingsToIntTask<K,V>
5806	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5807	+	rights, transformer, r, reducer)).fork();
5808	+	}
5809	+	for (Node<K,V> p; (p = advance()) != null; )
5810	+	r = reducer.applyAsInt(r, transformer.applyAsInt((K)p.key, p.val));
5811	+	result = r;
5812	+	CountedCompleter<?> c;
5813	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5814	+	MapReduceMappingsToIntTask<K,V>
5815	+	t = (MapReduceMappingsToIntTask<K,V>)c,
5816	+	s = t.rights;
5817	+	while (s != null) {
5818	+	t.result = reducer.applyAsInt(t.result, s.result);
5819	+	s = t.rights = s.nextRight;
5820	+	}
5821	+	}
5822	+	}
5823	+	}
5824	+	}
5825	+
5826	+	// Unsafe mechanics
5827	+	private static final sun.misc.Unsafe U;
5828	+	private static final long SIZECTL;
5829	+	private static final long TRANSFERINDEX;
5830	+	private static final long TRANSFERORIGIN;
5831	+	private static final long BASECOUNT;
5832	+	private static final long CELLSBUSY;
5833	+	private static final long CELLVALUE;
5834	+	private static final long ABASE;
5835	+	private static final int ASHIFT;
5836	+
5837	+	static {
5838	+	try {
5839	+	U = sun.misc.Unsafe.getUnsafe();
5840	+	Class<?> k = ConcurrentHashMap.class;
5841	+	SIZECTL = U.objectFieldOffset
5842	+	(k.getDeclaredField("sizeCtl"));
5843	+	TRANSFERINDEX = U.objectFieldOffset
5844	+	(k.getDeclaredField("transferIndex"));
5845	+	TRANSFERORIGIN = U.objectFieldOffset
5846	+	(k.getDeclaredField("transferOrigin"));
5847	+	BASECOUNT = U.objectFieldOffset
5848	+	(k.getDeclaredField("baseCount"));
5849	+	CELLSBUSY = U.objectFieldOffset
5850	+	(k.getDeclaredField("cellsBusy"));
5851	+	Class<?> ck = Cell.class;
5852	+	CELLVALUE = U.objectFieldOffset
5853	+	(ck.getDeclaredField("value"));
5854	+	Class<?> sc = Node[].class;
5855	+	ABASE = U.arrayBaseOffset(sc);
5856	+	int scale = U.arrayIndexScale(sc);
5857	+	if ((scale & (scale - 1)) != 0)
5858	+	throw new Error("data type scale not a power of two");
5859	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
5860	+	} catch (Exception e) {
5861	+	throw new Error(e);
5862	+	}
5863	+	}
5864	+	}

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