ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/jsr166/jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java

Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.15 by tim, Wed Aug 6 18:22:09 2003 UTC vs.
Revision 1.290 by jsr166, Tue Mar 8 00:27:35 2016 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	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
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.atomic.AtomicReference;
25	>	import java.util.concurrent.locks.LockSupport;
26	>	import java.util.concurrent.locks.ReentrantLock;
27	>	import java.util.function.BiConsumer;
28	>	import java.util.function.BiFunction;
29	>	import java.util.function.Consumer;
30	>	import java.util.function.DoubleBinaryOperator;
31	>	import java.util.function.Function;
32	>	import java.util.function.IntBinaryOperator;
33	>	import java.util.function.LongBinaryOperator;
34	>	import java.util.function.Predicate;
35	>	import java.util.function.ToDoubleBiFunction;
36	>	import java.util.function.ToDoubleFunction;
37	>	import java.util.function.ToIntBiFunction;
38	>	import java.util.function.ToIntFunction;
39	>	import java.util.function.ToLongBiFunction;
40	>	import java.util.function.ToLongFunction;
41	>	import java.util.stream.Stream;
42
43		/**
44		* A hash table supporting full concurrency of retrievals and
45	<	* adjustable expected concurrency for updates. This class obeys the
46	<	* same functional specification as
47	<	* <tt>java.util.Hashtable</tt>. However, even though all operations
48	<	* are thread-safe, retrieval operations do <em>not</em> entail
49	<	* locking, and there is <em>not</em> any support for locking the
50	<	* entire table in a way that prevents all access.  This class is
51	<	* fully interoperable with Hashtable in programs that rely on its
45	>	* high expected concurrency for updates. This class obeys the
46	>	* same functional specification as {@link java.util.Hashtable}, and
47	>	* includes versions of methods corresponding to each method of
48	>	* {@code Hashtable}. However, even though all operations are
49	>	* thread-safe, retrieval operations do <em>not</em> entail locking,
50	>	* and there is <em>not</em> any support for locking the entire table
51	>	* in a way that prevents all access.  This class is fully
52	>	* interoperable with {@code Hashtable} in programs that rely on its
53		* thread safety but not on its synchronization details.
54		*
55	<	* <p> Retrieval operations (including <tt>get</tt>) ordinarily
56	<	* overlap with update operations (including <tt>put</tt> and
57	<	* <tt>remove</tt>). Retrievals reflect the results of the most
55	>	* <p>Retrieval operations (including {@code get}) generally do not
56	>	* block, so may overlap with update operations (including {@code put}
57	>	* and {@code remove}). Retrievals reflect the results of the most
58		* recently <em>completed</em> update operations holding upon their
59	<	* onset.  For aggregate operations such as <tt>putAll</tt> and
60	<	* <tt>clear</tt>, concurrent retrievals may reflect insertion or
61	<	* removal of only some entries.  Similarly, Iterators and
62	<	* Enumerations return elements reflecting the state of the hash table
63	<	* at some point at or since the creation of the iterator/enumeration.
64	<	* They do <em>not</em> throw ConcurrentModificationException.
65	<	* However, Iterators are designed to be used by only one thread at a
66	<	* time.
67	<	*
68	<	* <p> The allowed concurrency among update operations is controlled
69	<	* by the optional <tt>segments</tt> constructor argument (default
70	<	* 16). The table is divided into this many independent parts, each of
71	<	* which can be updated concurrently. Because placement in hash tables
72	<	* is essentially random, the actual concurrency will vary. As a rough
73	<	* rule of thumb, you should choose at least as many segments as you
74	<	* expect concurrent threads. However, using more segments than you
75	<	* need can waste space and time. Using a value of 1 for
76	<	* <tt>segments</tt> results in a table that is concurrently readable
77	<	* but can only be updated by one thread at a time.
59	>	* onset. (More formally, an update operation for a given key bears a
60	>	* <em>happens-before</em> relation with any (non-null) retrieval for
61	>	* that key reporting the updated value.)  For aggregate operations
62	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
63	>	* reflect insertion or removal of only some entries.  Similarly,
64	>	* Iterators, Spliterators and Enumerations return elements reflecting the
65	>	* state of the hash table at some point at or since the creation of the
66	>	* iterator/enumeration.  They do <em>not</em> throw {@link
67	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
68	>	* However, iterators are designed to be used by only one thread at a time.
69	>	* Bear in mind that the results of aggregate status methods including
70	>	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
71	>	* useful only when a map is not undergoing concurrent updates in other threads.
72	>	* Otherwise the results of these methods reflect transient states
73	>	* that may be adequate for monitoring or estimation purposes, but not
74	>	* for program control.
75	>	*
76	>	* <p>The table is dynamically expanded when there are too many
77	>	* collisions (i.e., keys that have distinct hash codes but fall into
78	>	* the same slot modulo the table size), with the expected average
79	>	* effect of maintaining roughly two bins per mapping (corresponding
80	>	* to a 0.75 load factor threshold for resizing). There may be much
81	>	* variance around this average as mappings are added and removed, but
82	>	* overall, this maintains a commonly accepted time/space tradeoff for
83	>	* hash tables.  However, resizing this or any other kind of hash
84	>	* table may be a relatively slow operation. When possible, it is a
85	>	* good idea to provide a size estimate as an optional {@code
86	>	* initialCapacity} constructor argument. An additional optional
87	>	* {@code loadFactor} constructor argument provides a further means of
88	>	* customizing initial table capacity by specifying the table density
89	>	* to be used in calculating the amount of space to allocate for the
90	>	* given number of elements.  Also, for compatibility with previous
91	>	* versions of this class, constructors may optionally specify an
92	>	* expected {@code concurrencyLevel} as an additional hint for
93	>	* internal sizing.  Note that using many keys with exactly the same
94	>	* {@code hashCode()} is a sure way to slow down performance of any
95	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
96	>	* this class may use comparison order among keys to help break ties.
97	>	*
98	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
99	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
100	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
101	>	* mapped values are (perhaps transiently) not used or all take the
102	>	* same mapping value.
103	>	*
104	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
105	>	* form of histogram or multiset) by using {@link
106	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
107	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
108	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
109	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
110	>	*
111	>	* <p>This class and its views and iterators implement all of the
112	>	* <em>optional</em> methods of the {@link Map} and {@link Iterator}
113	>	* interfaces.
114	>	*
115	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
116	>	* does <em>not</em> allow {@code null} to be used as a key or value.
117	>	*
118	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
119	>	* operations that, unlike most {@link Stream} methods, are designed
120	>	* to be safely, and often sensibly, applied even with maps that are
121	>	* being concurrently updated by other threads; for example, when
122	>	* computing a snapshot summary of the values in a shared registry.
123	>	* There are three kinds of operation, each with four forms, accepting
124	>	* functions with keys, values, entries, and (key, value) pairs as
125	>	* arguments and/or return values. Because the elements of a
126	>	* ConcurrentHashMap are not ordered in any particular way, and may be
127	>	* processed in different orders in different parallel executions, the
128	>	* correctness of supplied functions should not depend on any
129	>	* ordering, or on any other objects or values that may transiently
130	>	* change while computation is in progress; and except for forEach
131	>	* actions, should ideally be side-effect-free. Bulk operations on
132	>	* {@link java.util.Map.Entry} objects do not support method {@code
133	>	* setValue}.
134	>	*
135	>	* <ul>
136	>	* <li>forEach: Performs a given action on each element.
137	>	* A variant form applies a given transformation on each element
138	>	* before performing the action.
139	>	*
140	>	* <li>search: Returns the first available non-null result of
141	>	* applying a given function on each element; skipping further
142	>	* search when a result is found.
143	>	*
144	>	* <li>reduce: Accumulates each element.  The supplied reduction
145	>	* function cannot rely on ordering (more formally, it should be
146	>	* both associative and commutative).  There are five variants:
147	>	*
148	>	* <ul>
149	>	*
150	>	* <li>Plain reductions. (There is not a form of this method for
151	>	* (key, value) function arguments since there is no corresponding
152	>	* return type.)
153	>	*
154	>	* <li>Mapped reductions that accumulate the results of a given
155	>	* function applied to each element.
156	>	*
157	>	* <li>Reductions to scalar doubles, longs, and ints, using a
158	>	* given basis value.
159	>	*
160	>	* </ul>
161	>	* </ul>
162	>	*
163	>	* <p>These bulk operations accept a {@code parallelismThreshold}
164	>	* argument. Methods proceed sequentially if the current map size is
165	>	* estimated to be less than the given threshold. Using a value of
166	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
167	>	* of {@code 1} results in maximal parallelism by partitioning into
168	>	* enough subtasks to fully utilize the {@link
169	>	* ForkJoinPool#commonPool()} that is used for all parallel
170	>	* computations. Normally, you would initially choose one of these
171	>	* extreme values, and then measure performance of using in-between
172	>	* values that trade off overhead versus throughput.
173	>	*
174	>	* <p>The concurrency properties of bulk operations follow
175	>	* from those of ConcurrentHashMap: Any non-null result returned
176	>	* from {@code get(key)} and related access methods bears a
177	>	* happens-before relation with the associated insertion or
178	>	* update.  The result of any bulk operation reflects the
179	>	* composition of these per-element relations (but is not
180	>	* necessarily atomic with respect to the map as a whole unless it
181	>	* is somehow known to be quiescent).  Conversely, because keys
182	>	* and values in the map are never null, null serves as a reliable
183	>	* atomic indicator of the current lack of any result.  To
184	>	* maintain this property, null serves as an implicit basis for
185	>	* all non-scalar reduction operations. For the double, long, and
186	>	* int versions, the basis should be one that, when combined with
187	>	* any other value, returns that other value (more formally, it
188	>	* should be the identity element for the reduction). Most common
189	>	* reductions have these properties; for example, computing a sum
190	>	* with basis 0 or a minimum with basis MAX_VALUE.
191	>	*
192	>	* <p>Search and transformation functions provided as arguments
193	>	* should similarly return null to indicate the lack of any result
194	>	* (in which case it is not used). In the case of mapped
195	>	* reductions, this also enables transformations to serve as
196	>	* filters, returning null (or, in the case of primitive
197	>	* specializations, the identity basis) if the element should not
198	>	* be combined. You can create compound transformations and
199	>	* filterings by composing them yourself under this "null means
200	>	* there is nothing there now" rule before using them in search or
201	>	* reduce operations.
202	>	*
203	>	* <p>Methods accepting and/or returning Entry arguments maintain
204	>	* key-value associations. They may be useful for example when
205	>	* finding the key for the greatest value. Note that "plain" Entry
206	>	* arguments can be supplied using {@code new
207	>	* AbstractMap.SimpleEntry(k,v)}.
208	>	*
209	>	* <p>Bulk operations may complete abruptly, throwing an
210	>	* exception encountered in the application of a supplied
211	>	* function. Bear in mind when handling such exceptions that other
212	>	* concurrently executing functions could also have thrown
213	>	* exceptions, or would have done so if the first exception had
214	>	* not occurred.
215	>	*
216	>	* <p>Speedups for parallel compared to sequential forms are common
217	>	* but not guaranteed.  Parallel operations involving brief functions
218	>	* on small maps may execute more slowly than sequential forms if the
219	>	* underlying work to parallelize the computation is more expensive
220	>	* than the computation itself.  Similarly, parallelization may not
221	>	* lead to much actual parallelism if all processors are busy
222	>	* performing unrelated tasks.
223	>	*
224	>	* <p>All arguments to all task methods must be non-null.
225		*
226	<	* <p> Like Hashtable but unlike java.util.HashMap, this class does
227	<	* NOT allow <tt>null</tt> to be used as a key or value.
226	>	* <p>This class is a member of the
227	>	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
228	>	* Java Collections Framework</a>.
229		*
230		* @since 1.5
231		* @author Doug Lea
232	+	* @param <K> the type of keys maintained by this map
233	+	* @param <V> the type of mapped values
234		*/
235	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
236	<	implements ConcurrentMap<K, V>, Cloneable, Serializable {
235	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
236	>	implements ConcurrentMap<K,V>, Serializable {
237	>	private static final long serialVersionUID = 7249069246763182397L;
238
239		/*
240	<	* The basic strategy is to subdivide the table among Segments,
241	<	* each of which itself is a concurrently readable hash table.
240	>	* Overview:
241	>	*
242	>	* The primary design goal of this hash table is to maintain
243	>	* concurrent readability (typically method get(), but also
244	>	* iterators and related methods) while minimizing update
245	>	* contention. Secondary goals are to keep space consumption about
246	>	* the same or better than java.util.HashMap, and to support high
247	>	* initial insertion rates on an empty table by many threads.
248	>	*
249	>	* This map usually acts as a binned (bucketed) hash table.  Each
250	>	* key-value mapping is held in a Node.  Most nodes are instances
251	>	* of the basic Node class with hash, key, value, and next
252	>	* fields. However, various subclasses exist: TreeNodes are
253	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
254	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
255	>	* of bins during resizing. ReservationNodes are used as
256	>	* placeholders while establishing values in computeIfAbsent and
257	>	* related methods.  The types TreeBin, ForwardingNode, and
258	>	* ReservationNode do not hold normal user keys, values, or
259	>	* hashes, and are readily distinguishable during search etc
260	>	* because they have negative hash fields and null key and value
261	>	* fields. (These special nodes are either uncommon or transient,
262	>	* so the impact of carrying around some unused fields is
263	>	* insignificant.)
264	>	*
265	>	* The table is lazily initialized to a power-of-two size upon the
266	>	* first insertion.  Each bin in the table normally contains a
267	>	* list of Nodes (most often, the list has only zero or one Node).
268	>	* Table accesses require volatile/atomic reads, writes, and
269	>	* CASes.  Because there is no other way to arrange this without
270	>	* adding further indirections, we use intrinsics
271	>	* (sun.misc.Unsafe) operations.
272	>	*
273	>	* We use the top (sign) bit of Node hash fields for control
274	>	* purposes -- it is available anyway because of addressing
275	>	* constraints.  Nodes with negative hash fields are specially
276	>	* handled or ignored in map methods.
277	>	*
278	>	* Insertion (via put or its variants) of the first node in an
279	>	* empty bin is performed by just CASing it to the bin.  This is
280	>	* by far the most common case for put operations under most
281	>	* key/hash distributions.  Other update operations (insert,
282	>	* delete, and replace) require locks.  We do not want to waste
283	>	* the space required to associate a distinct lock object with
284	>	* each bin, so instead use the first node of a bin list itself as
285	>	* a lock. Locking support for these locks relies on builtin
286	>	* "synchronized" monitors.
287	>	*
288	>	* Using the first node of a list as a lock does not by itself
289	>	* suffice though: When a node is locked, any update must first
290	>	* validate that it is still the first node after locking it, and
291	>	* retry if not. Because new nodes are always appended to lists,
292	>	* once a node is first in a bin, it remains first until deleted
293	>	* or the bin becomes invalidated (upon resizing).
294	>	*
295	>	* The main disadvantage of per-bin locks is that other update
296	>	* operations on other nodes in a bin list protected by the same
297	>	* lock can stall, for example when user equals() or mapping
298	>	* functions take a long time.  However, statistically, under
299	>	* random hash codes, this is not a common problem.  Ideally, the
300	>	* frequency of nodes in bins follows a Poisson distribution
301	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
302	>	* parameter of about 0.5 on average, given the resizing threshold
303	>	* of 0.75, although with a large variance because of resizing
304	>	* granularity. Ignoring variance, the expected occurrences of
305	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
306	>	* first values are:
307	>	*
308	>	* 0:    0.60653066
309	>	* 1:    0.30326533
310	>	* 2:    0.07581633
311	>	* 3:    0.01263606
312	>	* 4:    0.00157952
313	>	* 5:    0.00015795
314	>	* 6:    0.00001316
315	>	* 7:    0.00000094
316	>	* 8:    0.00000006
317	>	* more: less than 1 in ten million
318	>	*
319	>	* Lock contention probability for two threads accessing distinct
320	>	* elements is roughly 1 / (8 * #elements) under random hashes.
321	>	*
322	>	* Actual hash code distributions encountered in practice
323	>	* sometimes deviate significantly from uniform randomness.  This
324	>	* includes the case when N > (1<<30), so some keys MUST collide.
325	>	* Similarly for dumb or hostile usages in which multiple keys are
326	>	* designed to have identical hash codes or ones that differs only
327	>	* in masked-out high bits. So we use a secondary strategy that
328	>	* applies when the number of nodes in a bin exceeds a
329	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
330	>	* specialized form of red-black trees), bounding search time to
331	>	* O(log N).  Each search step in a TreeBin is at least twice as
332	>	* slow as in a regular list, but given that N cannot exceed
333	>	* (1<<64) (before running out of addresses) this bounds search
334	>	* steps, lock hold times, etc, to reasonable constants (roughly
335	>	* 100 nodes inspected per operation worst case) so long as keys
336	>	* are Comparable (which is very common -- String, Long, etc).
337	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
338	>	* traversal pointers as regular nodes, so can be traversed in
339	>	* iterators in the same way.
340	>	*
341	>	* The table is resized when occupancy exceeds a percentage
342	>	* threshold (nominally, 0.75, but see below).  Any thread
343	>	* noticing an overfull bin may assist in resizing after the
344	>	* initiating thread allocates and sets up the replacement array.
345	>	* However, rather than stalling, these other threads may proceed
346	>	* with insertions etc.  The use of TreeBins shields us from the
347	>	* worst case effects of overfilling while resizes are in
348	>	* progress.  Resizing proceeds by transferring bins, one by one,
349	>	* from the table to the next table. However, threads claim small
350	>	* blocks of indices to transfer (via field transferIndex) before
351	>	* doing so, reducing contention.  A generation stamp in field
352	>	* sizeCtl ensures that resizings do not overlap. Because we are
353	>	* using power-of-two expansion, the elements from each bin must
354	>	* either stay at same index, or move with a power of two
355	>	* offset. We eliminate unnecessary node creation by catching
356	>	* cases where old nodes can be reused because their next fields
357	>	* won't change.  On average, only about one-sixth of them need
358	>	* cloning when a table doubles. The nodes they replace will be
359	>	* garbage collectable as soon as they are no longer referenced by
360	>	* any reader thread that may be in the midst of concurrently
361	>	* traversing table.  Upon transfer, the old table bin contains
362	>	* only a special forwarding node (with hash field "MOVED") that
363	>	* contains the next table as its key. On encountering a
364	>	* forwarding node, access and update operations restart, using
365	>	* the new table.
366	>	*
367	>	* Each bin transfer requires its bin lock, which can stall
368	>	* waiting for locks while resizing. However, because other
369	>	* threads can join in and help resize rather than contend for
370	>	* locks, average aggregate waits become shorter as resizing
371	>	* progresses.  The transfer operation must also ensure that all
372	>	* accessible bins in both the old and new table are usable by any
373	>	* traversal.  This is arranged in part by proceeding from the
374	>	* last bin (table.length - 1) up towards the first.  Upon seeing
375	>	* a forwarding node, traversals (see class Traverser) arrange to
376	>	* move to the new table without revisiting nodes.  To ensure that
377	>	* no intervening nodes are skipped even when moved out of order,
378	>	* a stack (see class TableStack) is created on first encounter of
379	>	* a forwarding node during a traversal, to maintain its place if
380	>	* later processing the current table. The need for these
381	>	* save/restore mechanics is relatively rare, but when one
382	>	* forwarding node is encountered, typically many more will be.
383	>	* So Traversers use a simple caching scheme to avoid creating so
384	>	* many new TableStack nodes. (Thanks to Peter Levart for
385	>	* suggesting use of a stack here.)
386	>	*
387	>	* The traversal scheme also applies to partial traversals of
388	>	* ranges of bins (via an alternate Traverser constructor)
389	>	* to support partitioned aggregate operations.  Also, read-only
390	>	* operations give up if ever forwarded to a null table, which
391	>	* provides support for shutdown-style clearing, which is also not
392	>	* currently implemented.
393	>	*
394	>	* Lazy table initialization minimizes footprint until first use,
395	>	* and also avoids resizings when the first operation is from a
396	>	* putAll, constructor with map argument, or deserialization.
397	>	* These cases attempt to override the initial capacity settings,
398	>	* but harmlessly fail to take effect in cases of races.
399	>	*
400	>	* The element count is maintained using a specialization of
401	>	* LongAdder. We need to incorporate a specialization rather than
402	>	* just use a LongAdder in order to access implicit
403	>	* contention-sensing that leads to creation of multiple
404	>	* CounterCells.  The counter mechanics avoid contention on
405	>	* updates but can encounter cache thrashing if read too
406	>	* frequently during concurrent access. To avoid reading so often,
407	>	* resizing under contention is attempted only upon adding to a
408	>	* bin already holding two or more nodes. Under uniform hash
409	>	* distributions, the probability of this occurring at threshold
410	>	* is around 13%, meaning that only about 1 in 8 puts check
411	>	* threshold (and after resizing, many fewer do so).
412	>	*
413	>	* TreeBins use a special form of comparison for search and
414	>	* related operations (which is the main reason we cannot use
415	>	* existing collections such as TreeMaps). TreeBins contain
416	>	* Comparable elements, but may contain others, as well as
417	>	* elements that are Comparable but not necessarily Comparable for
418	>	* the same T, so we cannot invoke compareTo among them. To handle
419	>	* this, the tree is ordered primarily by hash value, then by
420	>	* Comparable.compareTo order if applicable.  On lookup at a node,
421	>	* if elements are not comparable or compare as 0 then both left
422	>	* and right children may need to be searched in the case of tied
423	>	* hash values. (This corresponds to the full list search that
424	>	* would be necessary if all elements were non-Comparable and had
425	>	* tied hashes.) On insertion, to keep a total ordering (or as
426	>	* close as is required here) across rebalancings, we compare
427	>	* classes and identityHashCodes as tie-breakers. The red-black
428	>	* balancing code is updated from pre-jdk-collections
429	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
430	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
431	>	* Algorithms" (CLR).
432	>	*
433	>	* TreeBins also require an additional locking mechanism.  While
434	>	* list traversal is always possible by readers even during
435	>	* updates, tree traversal is not, mainly because of tree-rotations
436	>	* that may change the root node and/or its linkages.  TreeBins
437	>	* include a simple read-write lock mechanism parasitic on the
438	>	* main bin-synchronization strategy: Structural adjustments
439	>	* associated with an insertion or removal are already bin-locked
440	>	* (and so cannot conflict with other writers) but must wait for
441	>	* ongoing readers to finish. Since there can be only one such
442	>	* waiter, we use a simple scheme using a single "waiter" field to
443	>	* block writers.  However, readers need never block.  If the root
444	>	* lock is held, they proceed along the slow traversal path (via
445	>	* next-pointers) until the lock becomes available or the list is
446	>	* exhausted, whichever comes first. These cases are not fast, but
447	>	* maximize aggregate expected throughput.
448	>	*
449	>	* Maintaining API and serialization compatibility with previous
450	>	* versions of this class introduces several oddities. Mainly: We
451	>	* leave untouched but unused constructor arguments referring to
452	>	* concurrencyLevel. We accept a loadFactor constructor argument,
453	>	* but apply it only to initial table capacity (which is the only
454	>	* time that we can guarantee to honor it.) We also declare an
455	>	* unused "Segment" class that is instantiated in minimal form
456	>	* only when serializing.
457	>	*
458	>	* Also, solely for compatibility with previous versions of this
459	>	* class, it extends AbstractMap, even though all of its methods
460	>	* are overridden, so it is just useless baggage.
461	>	*
462	>	* This file is organized to make things a little easier to follow
463	>	* while reading than they might otherwise: First the main static
464	>	* declarations and utilities, then fields, then main public
465	>	* methods (with a few factorings of multiple public methods into
466	>	* internal ones), then sizing methods, trees, traversers, and
467	>	* bulk operations.
468		*/
469
470		/* ---------------- Constants -------------- */
471
472		/**
473	<	* The default initial number of table slots for this table (32).
474	<	* Used when not otherwise specified in constructor.
473	>	* The largest possible table capacity.  This value must be
474	>	* exactly 1<<30 to stay within Java array allocation and indexing
475	>	* bounds for power of two table sizes, and is further required
476	>	* because the top two bits of 32bit hash fields are used for
477	>	* control purposes.
478	>	*/
479	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
480	>
481	>	/**
482	>	* The default initial table capacity.  Must be a power of 2
483	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
484	>	*/
485	>	private static final int DEFAULT_CAPACITY = 16;
486	>
487	>	/**
488	>	* The largest possible (non-power of two) array size.
489	>	* Needed by toArray and related methods.
490	>	*/
491	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
492	>
493	>	/**
494	>	* The default concurrency level for this table. Unused but
495	>	* defined for compatibility with previous versions of this class.
496	>	*/
497	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
498	>
499	>	/**
500	>	* The load factor for this table. Overrides of this value in
501	>	* constructors affect only the initial table capacity.  The
502	>	* actual floating point value isn't normally used -- it is
503	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
504	>	* the associated resizing threshold.
505	>	*/
506	>	private static final float LOAD_FACTOR = 0.75f;
507	>
508	>	/**
509	>	* The bin count threshold for using a tree rather than list for a
510	>	* bin.  Bins are converted to trees when adding an element to a
511	>	* bin with at least this many nodes. The value must be greater
512	>	* than 2, and should be at least 8 to mesh with assumptions in
513	>	* tree removal about conversion back to plain bins upon
514	>	* shrinkage.
515	>	*/
516	>	static final int TREEIFY_THRESHOLD = 8;
517	>
518	>	/**
519	>	* The bin count threshold for untreeifying a (split) bin during a
520	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
521	>	* most 6 to mesh with shrinkage detection under removal.
522	>	*/
523	>	static final int UNTREEIFY_THRESHOLD = 6;
524	>
525	>	/**
526	>	* The smallest table capacity for which bins may be treeified.
527	>	* (Otherwise the table is resized if too many nodes in a bin.)
528	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
529	>	* conflicts between resizing and treeification thresholds.
530	>	*/
531	>	static final int MIN_TREEIFY_CAPACITY = 64;
532	>
533	>	/**
534	>	* Minimum number of rebinnings per transfer step. Ranges are
535	>	* subdivided to allow multiple resizer threads.  This value
536	>	* serves as a lower bound to avoid resizers encountering
537	>	* excessive memory contention.  The value should be at least
538	>	* DEFAULT_CAPACITY.
539	>	*/
540	>	private static final int MIN_TRANSFER_STRIDE = 16;
541	>
542	>	/**
543	>	* The number of bits used for generation stamp in sizeCtl.
544	>	* Must be at least 6 for 32bit arrays.
545	>	*/
546	>	private static final int RESIZE_STAMP_BITS = 16;
547	>
548	>	/**
549	>	* The maximum number of threads that can help resize.
550	>	* Must fit in 32 - RESIZE_STAMP_BITS bits.
551	>	*/
552	>	private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
553	>
554	>	/**
555	>	* The bit shift for recording size stamp in sizeCtl.
556	>	*/
557	>	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
558	>
559	>	/*
560	>	* Encodings for Node hash fields. See above for explanation.
561	>	*/
562	>	static final int MOVED     = -1; // hash for forwarding nodes
563	>	static final int TREEBIN   = -2; // hash for roots of trees
564	>	static final int RESERVED  = -3; // hash for transient reservations
565	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
566	>
567	>	/** Number of CPUS, to place bounds on some sizings */
568	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
569	>
570	>	/**
571	>	* Serialized pseudo-fields, provided only for jdk7 compatibility.
572	>	* @serialField segments Segment[]
573	>	*   The segments, each of which is a specialized hash table.
574	>	* @serialField segmentMask int
575	>	*   Mask value for indexing into segments. The upper bits of a
576	>	*   key's hash code are used to choose the segment.
577	>	* @serialField segmentShift int
578	>	*   Shift value for indexing within segments.
579	>	*/
580	>	private static final ObjectStreamField[] serialPersistentFields = {
581	>	new ObjectStreamField("segments", Segment[].class),
582	>	new ObjectStreamField("segmentMask", Integer.TYPE),
583	>	new ObjectStreamField("segmentShift", Integer.TYPE),
584	>	};
585	>
586	>	/* ---------------- Nodes -------------- */
587	>
588	>	/**
589	>	* Key-value entry.  This class is never exported out as a
590	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
591	>	* MapEntry below), but can be used for read-only traversals used
592	>	* in bulk tasks.  Subclasses of Node with a negative hash field
593	>	* are special, and contain null keys and values (but are never
594	>	* exported).  Otherwise, keys and vals are never null.
595	>	*/
596	>	static class Node<K,V> implements Map.Entry<K,V> {
597	>	final int hash;
598	>	final K key;
599	>	volatile V val;
600	>	volatile Node<K,V> next;
601	>
602	>	Node(int hash, K key, V val) {
603	>	this.hash = hash;
604	>	this.key = key;
605	>	this.val = val;
606	>	}
607	>
608	>	Node(int hash, K key, V val, Node<K,V> next) {
609	>	this(hash, key, val);
610	>	this.next = next;
611	>	}
612	>
613	>	public final K getKey()     { return key; }
614	>	public final V getValue()   { return val; }
615	>	public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
616	>	public final String toString() {
617	>	return Helpers.mapEntryToString(key, val);
618	>	}
619	>	public final V setValue(V value) {
620	>	throw new UnsupportedOperationException();
621	>	}
622	>
623	>	public final boolean equals(Object o) {
624	>	Object k, v, u; Map.Entry<?,?> e;
625	>	return ((o instanceof Map.Entry) &&
626	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
627	>	(v = e.getValue()) != null &&
628	>	(k == key || k.equals(key)) &&
629	>	(v == (u = val) || v.equals(u)));
630	>	}
631	>
632	>	/**
633	>	* Virtualized support for map.get(); overridden in subclasses.
634	>	*/
635	>	Node<K,V> find(int h, Object k) {
636	>	Node<K,V> e = this;
637	>	if (k != null) {
638	>	do {
639	>	K ek;
640	>	if (e.hash == h &&
641	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
642	>	return e;
643	>	} while ((e = e.next) != null);
644	>	}
645	>	return null;
646	>	}
647	>	}
648	>
649	>	/* ---------------- Static utilities -------------- */
650	>
651	>	/**
652	>	* Spreads (XORs) higher bits of hash to lower and also forces top
653	>	* bit to 0. Because the table uses power-of-two masking, sets of
654	>	* hashes that vary only in bits above the current mask will
655	>	* always collide. (Among known examples are sets of Float keys
656	>	* holding consecutive whole numbers in small tables.)  So we
657	>	* apply a transform that spreads the impact of higher bits
658	>	* downward. There is a tradeoff between speed, utility, and
659	>	* quality of bit-spreading. Because many common sets of hashes
660	>	* are already reasonably distributed (so don't benefit from
661	>	* spreading), and because we use trees to handle large sets of
662	>	* collisions in bins, we just XOR some shifted bits in the
663	>	* cheapest possible way to reduce systematic lossage, as well as
664	>	* to incorporate impact of the highest bits that would otherwise
665	>	* never be used in index calculations because of table bounds.
666		*/
667	<	private static int DEFAULT_INITIAL_CAPACITY = 16;
667	>	static final int spread(int h) {
668	>	return (h ^ (h >>> 16)) & HASH_BITS;
669	>	}
670
671		/**
672	<	* The maximum capacity, used if a higher value is implicitly
673	<	* specified by either of the constructors with arguments.  MUST
75	<	* be a power of two <= 1<<30.
672	>	* Returns a power of two table size for the given desired capacity.
673	>	* See Hackers Delight, sec 3.2
674		*/
675	<	static final int MAXIMUM_CAPACITY = 1 << 30;
675	>	private static final int tableSizeFor(int c) {
676	>	int n = c - 1;
677	>	n |= n >>> 1;
678	>	n |= n >>> 2;
679	>	n |= n >>> 4;
680	>	n |= n >>> 8;
681	>	n |= n >>> 16;
682	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
683	>	}
684
685		/**
686	<	* The default load factor for this table.  Used when not
687	<	* otherwise specified in constructor.
686	>	* Returns x's Class if it is of the form "class C implements
687	>	* Comparable<C>", else null.
688		*/
689	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
689	>	static Class<?> comparableClassFor(Object x) {
690	>	if (x instanceof Comparable) {
691	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
692	>	if ((c = x.getClass()) == String.class) // bypass checks
693	>	return c;
694	>	if ((ts = c.getGenericInterfaces()) != null) {
695	>	for (int i = 0; i < ts.length; ++i) {
696	>	if (((t = ts[i]) instanceof ParameterizedType) &&
697	>	((p = (ParameterizedType)t).getRawType() ==
698	>	Comparable.class) &&
699	>	(as = p.getActualTypeArguments()) != null &&
700	>	as.length == 1 && as[0] == c) // type arg is c
701	>	return c;
702	>	}
703	>	}
704	>	}
705	>	return null;
706	>	}
707
708		/**
709	<	* The default number of concurrency control segments.
710	<	**/
711	<	private static final int DEFAULT_SEGMENTS = 16;
709	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
710	>	* class), else 0.
711	>	*/
712	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
713	>	static int compareComparables(Class<?> kc, Object k, Object x) {
714	>	return (x == null || x.getClass() != kc ? 0 :
715	>	((Comparable)k).compareTo(x));
716	>	}
717	>
718	>	/* ---------------- Table element access -------------- */
719	>
720	>	/*
721	>	* Volatile access methods are used for table elements as well as
722	>	* elements of in-progress next table while resizing.  All uses of
723	>	* the tab arguments must be null checked by callers.  All callers
724	>	* also paranoically precheck that tab's length is not zero (or an
725	>	* equivalent check), thus ensuring that any index argument taking
726	>	* the form of a hash value anded with (length - 1) is a valid
727	>	* index.  Note that, to be correct wrt arbitrary concurrency
728	>	* errors by users, these checks must operate on local variables,
729	>	* which accounts for some odd-looking inline assignments below.
730	>	* Note that calls to setTabAt always occur within locked regions,
731	>	* and so in principle require only release ordering, not
732	>	* full volatile semantics, but are currently coded as volatile
733	>	* writes to be conservative.
734	>	*/
735	>
736	>	@SuppressWarnings("unchecked")
737	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
738	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
739	>	}
740	>
741	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
742	>	Node<K,V> c, Node<K,V> v) {
743	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
744	>	}
745	>
746	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
747	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
748	>	}
749
750		/* ---------------- Fields -------------- */
751
752		/**
753	<	* Mask value for indexing into segments. The upper bits of a
754	<	* key's hash code are used to choose the segment.
755	<	**/
756	<	private final int segmentMask;
753	>	* The array of bins. Lazily initialized upon first insertion.
754	>	* Size is always a power of two. Accessed directly by iterators.
755	>	*/
756	>	transient volatile Node<K,V>[] table;
757	>
758	>	/**
759	>	* The next table to use; non-null only while resizing.
760	>	*/
761	>	private transient volatile Node<K,V>[] nextTable;
762	>
763	>	/**
764	>	* Base counter value, used mainly when there is no contention,
765	>	* but also as a fallback during table initialization
766	>	* races. Updated via CAS.
767	>	*/
768	>	private transient volatile long baseCount;
769	>
770	>	/**
771	>	* Table initialization and resizing control.  When negative, the
772	>	* table is being initialized or resized: -1 for initialization,
773	>	* else -(1 + the number of active resizing threads).  Otherwise,
774	>	* when table is null, holds the initial table size to use upon
775	>	* creation, or 0 for default. After initialization, holds the
776	>	* next element count value upon which to resize the table.
777	>	*/
778	>	private transient volatile int sizeCtl;
779	>
780	>	/**
781	>	* The next table index (plus one) to split while resizing.
782	>	*/
783	>	private transient volatile int transferIndex;
784	>
785	>	/**
786	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
787	>	*/
788	>	private transient volatile int cellsBusy;
789	>
790	>	/**
791	>	* Table of counter cells. When non-null, size is a power of 2.
792	>	*/
793	>	private transient volatile CounterCell[] counterCells;
794	>
795	>	// views
796	>	private transient KeySetView<K,V> keySet;
797	>	private transient ValuesView<K,V> values;
798	>	private transient EntrySetView<K,V> entrySet;
799	>
800	>
801	>	/* ---------------- Public operations -------------- */
802
803		/**
804	<	* Shift value for indexing within segments.
805	<	**/
806	<	private final int segmentShift;
804	>	* Creates a new, empty map with the default initial table size (16).
805	>	*/
806	>	public ConcurrentHashMap() {
807	>	}
808
809		/**
810	<	* The segments, each of which is a specialized hash table
810	>	* Creates a new, empty map with an initial table size
811	>	* accommodating the specified number of elements without the need
812	>	* to dynamically resize.
813	>	*
814	>	* @param initialCapacity The implementation performs internal
815	>	* sizing to accommodate this many elements.
816	>	* @throws IllegalArgumentException if the initial capacity of
817	>	* elements is negative
818		*/
819	<	private final Segment[] segments;
819	>	public ConcurrentHashMap(int initialCapacity) {
820	>	if (initialCapacity < 0)
821	>	throw new IllegalArgumentException();
822	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
823	>	MAXIMUM_CAPACITY :
824	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
825	>	this.sizeCtl = cap;
826	>	}
827
828	<	private transient Set<K> keySet;
829	<	private transient Set<Map.Entry<K,V>> entrySet;
830	<	private transient Collection<V> values;
828	>	/**
829	>	* Creates a new map with the same mappings as the given map.
830	>	*
831	>	* @param m the map
832	>	*/
833	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
834	>	this.sizeCtl = DEFAULT_CAPACITY;
835	>	putAll(m);
836	>	}
837
838	<	/* ---------------- Small Utilities -------------- */
838	>	/**
839	>	* Creates a new, empty map with an initial table size based on
840	>	* the given number of elements ({@code initialCapacity}) and
841	>	* initial table density ({@code loadFactor}).
842	>	*
843	>	* @param initialCapacity the initial capacity. The implementation
844	>	* performs internal sizing to accommodate this many elements,
845	>	* given the specified load factor.
846	>	* @param loadFactor the load factor (table density) for
847	>	* establishing the initial table size
848	>	* @throws IllegalArgumentException if the initial capacity of
849	>	* elements is negative or the load factor is nonpositive
850	>	*
851	>	* @since 1.6
852	>	*/
853	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
854	>	this(initialCapacity, loadFactor, 1);
855	>	}
856
857		/**
858	<	* Return a hash code for non-null Object x.
859	<	* Uses the same hash code spreader as most other j.u hash tables.
860	<	* @param x the object serving as a key
861	<	* @return the hash code
858	>	* Creates a new, empty map with an initial table size based on
859	>	* the given number of elements ({@code initialCapacity}), table
860	>	* density ({@code loadFactor}), and number of concurrently
861	>	* updating threads ({@code concurrencyLevel}).
862	>	*
863	>	* @param initialCapacity the initial capacity. The implementation
864	>	* performs internal sizing to accommodate this many elements,
865	>	* given the specified load factor.
866	>	* @param loadFactor the load factor (table density) for
867	>	* establishing the initial table size
868	>	* @param concurrencyLevel the estimated number of concurrently
869	>	* updating threads. The implementation may use this value as
870	>	* a sizing hint.
871	>	* @throws IllegalArgumentException if the initial capacity is
872	>	* negative or the load factor or concurrencyLevel are
873	>	* nonpositive
874		*/
875	<	private static int hash(Object x) {
876	<	int h = x.hashCode();
877	<	h += ~(h << 9);
878	<	h ^=  (h >>> 14);
879	<	h +=  (h << 4);
880	<	h ^=  (h >>> 10);
875	>	public ConcurrentHashMap(int initialCapacity,
876	>	float loadFactor, int concurrencyLevel) {
877	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
878	>	throw new IllegalArgumentException();
879	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
880	>	initialCapacity = concurrencyLevel;   // as estimated threads
881	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
882	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
883	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
884	>	this.sizeCtl = cap;
885	>	}
886	>
887	>	// Original (since JDK1.2) Map methods
888	>
889	>	/**
890	>	* {@inheritDoc}
891	>	*/
892	>	public int size() {
893	>	long n = sumCount();
894	>	return ((n < 0L) ? 0 :
895	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
896	>	(int)n);
897	>	}
898	>
899	>	/**
900	>	* {@inheritDoc}
901	>	*/
902	>	public boolean isEmpty() {
903	>	return sumCount() <= 0L; // ignore transient negative values
904	>	}
905	>
906	>	/**
907	>	* Returns the value to which the specified key is mapped,
908	>	* or {@code null} if this map contains no mapping for the key.
909	>	*
910	>	* <p>More formally, if this map contains a mapping from a key
911	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
912	>	* then this method returns {@code v}; otherwise it returns
913	>	* {@code null}.  (There can be at most one such mapping.)
914	>	*
915	>	* @throws NullPointerException if the specified key is null
916	>	*/
917	>	public V get(Object key) {
918	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
919	>	int h = spread(key.hashCode());
920	>	if ((tab = table) != null && (n = tab.length) > 0 &&
921	>	(e = tabAt(tab, (n - 1) & h)) != null) {
922	>	if ((eh = e.hash) == h) {
923	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
924	>	return e.val;
925	>	}
926	>	else if (eh < 0)
927	>	return (p = e.find(h, key)) != null ? p.val : null;
928	>	while ((e = e.next) != null) {
929	>	if (e.hash == h &&
930	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
931	>	return e.val;
932	>	}
933	>	}
934	>	return null;
935	>	}
936	>
937	>	/**
938	>	* Tests if the specified object is a key in this table.
939	>	*
940	>	* @param  key possible key
941	>	* @return {@code true} if and only if the specified object
942	>	*         is a key in this table, as determined by the
943	>	*         {@code equals} method; {@code false} otherwise
944	>	* @throws NullPointerException if the specified key is null
945	>	*/
946	>	public boolean containsKey(Object key) {
947	>	return get(key) != null;
948	>	}
949	>
950	>	/**
951	>	* Returns {@code true} if this map maps one or more keys to the
952	>	* specified value. Note: This method may require a full traversal
953	>	* of the map, and is much slower than method {@code containsKey}.
954	>	*
955	>	* @param value value whose presence in this map is to be tested
956	>	* @return {@code true} if this map maps one or more keys to the
957	>	*         specified value
958	>	* @throws NullPointerException if the specified value is null
959	>	*/
960	>	public boolean containsValue(Object value) {
961	>	if (value == null)
962	>	throw new NullPointerException();
963	>	Node<K,V>[] t;
964	>	if ((t = table) != null) {
965	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
966	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
967	>	V v;
968	>	if ((v = p.val) == value || (v != null && value.equals(v)))
969	>	return true;
970	>	}
971	>	}
972	>	return false;
973	>	}
974	>
975	>	/**
976	>	* Maps the specified key to the specified value in this table.
977	>	* Neither the key nor the value can be null.
978	>	*
979	>	* <p>The value can be retrieved by calling the {@code get} method
980	>	* with a key that is equal to the original key.
981	>	*
982	>	* @param key key with which the specified value is to be associated
983	>	* @param value value to be associated with the specified key
984	>	* @return the previous value associated with {@code key}, or
985	>	*         {@code null} if there was no mapping for {@code key}
986	>	* @throws NullPointerException if the specified key or value is null
987	>	*/
988	>	public V put(K key, V value) {
989	>	return putVal(key, value, false);
990	>	}
991	>
992	>	/** Implementation for put and putIfAbsent */
993	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
994	>	if (key == null || value == null) throw new NullPointerException();
995	>	int hash = spread(key.hashCode());
996	>	int binCount = 0;
997	>	for (Node<K,V>[] tab = table;;) {
998	>	Node<K,V> f; int n, i, fh;
999	>	if (tab == null || (n = tab.length) == 0)
1000	>	tab = initTable();
1001	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1002	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
1003	>	break;                   // no lock when adding to empty bin
1004	>	}
1005	>	else if ((fh = f.hash) == MOVED)
1006	>	tab = helpTransfer(tab, f);
1007	>	else {
1008	>	V oldVal = null;
1009	>	synchronized (f) {
1010	>	if (tabAt(tab, i) == f) {
1011	>	if (fh >= 0) {
1012	>	binCount = 1;
1013	>	for (Node<K,V> e = f;; ++binCount) {
1014	>	K ek;
1015	>	if (e.hash == hash &&
1016	>	((ek = e.key) == key ||
1017	>	(ek != null && key.equals(ek)))) {
1018	>	oldVal = e.val;
1019	>	if (!onlyIfAbsent)
1020	>	e.val = value;
1021	>	break;
1022	>	}
1023	>	Node<K,V> pred = e;
1024	>	if ((e = e.next) == null) {
1025	>	pred.next = new Node<K,V>(hash, key, value);
1026	>	break;
1027	>	}
1028	>	}
1029	>	}
1030	>	else if (f instanceof TreeBin) {
1031	>	Node<K,V> p;
1032	>	binCount = 2;
1033	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1034	>	value)) != null) {
1035	>	oldVal = p.val;
1036	>	if (!onlyIfAbsent)
1037	>	p.val = value;
1038	>	}
1039	>	}
1040	>	else if (f instanceof ReservationNode)
1041	>	throw new IllegalStateException("Recursive update");
1042	>	}
1043	>	}
1044	>	if (binCount != 0) {
1045	>	if (binCount >= TREEIFY_THRESHOLD)
1046	>	treeifyBin(tab, i);
1047	>	if (oldVal != null)
1048	>	return oldVal;
1049	>	break;
1050	>	}
1051	>	}
1052	>	}
1053	>	addCount(1L, binCount);
1054	>	return null;
1055	>	}
1056	>
1057	>	/**
1058	>	* Copies all of the mappings from the specified map to this one.
1059	>	* These mappings replace any mappings that this map had for any of the
1060	>	* keys currently in the specified map.
1061	>	*
1062	>	* @param m mappings to be stored in this map
1063	>	*/
1064	>	public void putAll(Map<? extends K, ? extends V> m) {
1065	>	tryPresize(m.size());
1066	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1067	>	putVal(e.getKey(), e.getValue(), false);
1068	>	}
1069	>
1070	>	/**
1071	>	* Removes the key (and its corresponding value) from this map.
1072	>	* This method does nothing if the key is not in the map.
1073	>	*
1074	>	* @param  key the key that needs to be removed
1075	>	* @return the previous value associated with {@code key}, or
1076	>	*         {@code null} if there was no mapping for {@code key}
1077	>	* @throws NullPointerException if the specified key is null
1078	>	*/
1079	>	public V remove(Object key) {
1080	>	return replaceNode(key, null, null);
1081	>	}
1082	>
1083	>	/**
1084	>	* Implementation for the four public remove/replace methods:
1085	>	* Replaces node value with v, conditional upon match of cv if
1086	>	* non-null.  If resulting value is null, delete.
1087	>	*/
1088	>	final V replaceNode(Object key, V value, Object cv) {
1089	>	int hash = spread(key.hashCode());
1090	>	for (Node<K,V>[] tab = table;;) {
1091	>	Node<K,V> f; int n, i, fh;
1092	>	if (tab == null || (n = tab.length) == 0 ||
1093	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1094	>	break;
1095	>	else if ((fh = f.hash) == MOVED)
1096	>	tab = helpTransfer(tab, f);
1097	>	else {
1098	>	V oldVal = null;
1099	>	boolean validated = false;
1100	>	synchronized (f) {
1101	>	if (tabAt(tab, i) == f) {
1102	>	if (fh >= 0) {
1103	>	validated = true;
1104	>	for (Node<K,V> e = f, pred = null;;) {
1105	>	K ek;
1106	>	if (e.hash == hash &&
1107	>	((ek = e.key) == key ||
1108	>	(ek != null && key.equals(ek)))) {
1109	>	V ev = e.val;
1110	>	if (cv == null || cv == ev ||
1111	>	(ev != null && cv.equals(ev))) {
1112	>	oldVal = ev;
1113	>	if (value != null)
1114	>	e.val = value;
1115	>	else if (pred != null)
1116	>	pred.next = e.next;
1117	>	else
1118	>	setTabAt(tab, i, e.next);
1119	>	}
1120	>	break;
1121	>	}
1122	>	pred = e;
1123	>	if ((e = e.next) == null)
1124	>	break;
1125	>	}
1126	>	}
1127	>	else if (f instanceof TreeBin) {
1128	>	validated = true;
1129	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1130	>	TreeNode<K,V> r, p;
1131	>	if ((r = t.root) != null &&
1132	>	(p = r.findTreeNode(hash, key, null)) != null) {
1133	>	V pv = p.val;
1134	>	if (cv == null || cv == pv ||
1135	>	(pv != null && cv.equals(pv))) {
1136	>	oldVal = pv;
1137	>	if (value != null)
1138	>	p.val = value;
1139	>	else if (t.removeTreeNode(p))
1140	>	setTabAt(tab, i, untreeify(t.first));
1141	>	}
1142	>	}
1143	>	}
1144	>	else if (f instanceof ReservationNode)
1145	>	throw new IllegalStateException("Recursive update");
1146	>	}
1147	>	}
1148	>	if (validated) {
1149	>	if (oldVal != null) {
1150	>	if (value == null)
1151	>	addCount(-1L, -1);
1152	>	return oldVal;
1153	>	}
1154	>	break;
1155	>	}
1156	>	}
1157	>	}
1158	>	return null;
1159	>	}
1160	>
1161	>	/**
1162	>	* Removes all of the mappings from this map.
1163	>	*/
1164	>	public void clear() {
1165	>	long delta = 0L; // negative number of deletions
1166	>	int i = 0;
1167	>	Node<K,V>[] tab = table;
1168	>	while (tab != null && i < tab.length) {
1169	>	int fh;
1170	>	Node<K,V> f = tabAt(tab, i);
1171	>	if (f == null)
1172	>	++i;
1173	>	else if ((fh = f.hash) == MOVED) {
1174	>	tab = helpTransfer(tab, f);
1175	>	i = 0; // restart
1176	>	}
1177	>	else {
1178	>	synchronized (f) {
1179	>	if (tabAt(tab, i) == f) {
1180	>	Node<K,V> p = (fh >= 0 ? f :
1181	>	(f instanceof TreeBin) ?
1182	>	((TreeBin<K,V>)f).first : null);
1183	>	while (p != null) {
1184	>	--delta;
1185	>	p = p.next;
1186	>	}
1187	>	setTabAt(tab, i++, null);
1188	>	}
1189	>	}
1190	>	}
1191	>	}
1192	>	if (delta != 0L)
1193	>	addCount(delta, -1);
1194	>	}
1195	>
1196	>	/**
1197	>	* Returns a {@link Set} view of the keys contained in this map.
1198	>	* The set is backed by the map, so changes to the map are
1199	>	* reflected in the set, and vice-versa. The set supports element
1200	>	* removal, which removes the corresponding mapping from this map,
1201	>	* via the {@code Iterator.remove}, {@code Set.remove},
1202	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1203	>	* operations.  It does not support the {@code add} or
1204	>	* {@code addAll} operations.
1205	>	*
1206	>	* <p>The view's iterators and spliterators are
1207	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1208	>	*
1209	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1210	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1211	>	*
1212	>	* @return the set view
1213	>	*/
1214	>	public KeySetView<K,V> keySet() {
1215	>	KeySetView<K,V> ks;
1216	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1217	>	}
1218	>
1219	>	/**
1220	>	* Returns a {@link Collection} view of the values contained in this map.
1221	>	* The collection is backed by the map, so changes to the map are
1222	>	* reflected in the collection, and vice-versa.  The collection
1223	>	* supports element removal, which removes the corresponding
1224	>	* mapping from this map, via the {@code Iterator.remove},
1225	>	* {@code Collection.remove}, {@code removeAll},
1226	>	* {@code retainAll}, and {@code clear} operations.  It does not
1227	>	* support the {@code add} or {@code addAll} operations.
1228	>	*
1229	>	* <p>The view's iterators and spliterators are
1230	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1231	>	*
1232	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1233	>	* and {@link Spliterator#NONNULL}.
1234	>	*
1235	>	* @return the collection view
1236	>	*/
1237	>	public Collection<V> values() {
1238	>	ValuesView<K,V> vs;
1239	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1240	>	}
1241	>
1242	>	/**
1243	>	* Returns a {@link Set} view of the mappings contained in this map.
1244	>	* The set is backed by the map, so changes to the map are
1245	>	* reflected in the set, and vice-versa.  The set supports element
1246	>	* removal, which removes the corresponding mapping from the map,
1247	>	* via the {@code Iterator.remove}, {@code Set.remove},
1248	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1249	>	* operations.
1250	>	*
1251	>	* <p>The view's iterators and spliterators are
1252	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1253	>	*
1254	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1255	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1256	>	*
1257	>	* @return the set view
1258	>	*/
1259	>	public Set<Map.Entry<K,V>> entrySet() {
1260	>	EntrySetView<K,V> es;
1261	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1262	>	}
1263	>
1264	>	/**
1265	>	* Returns the hash code value for this {@link Map}, i.e.,
1266	>	* the sum of, for each key-value pair in the map,
1267	>	* {@code key.hashCode() ^ value.hashCode()}.
1268	>	*
1269	>	* @return the hash code value for this map
1270	>	*/
1271	>	public int hashCode() {
1272	>	int h = 0;
1273	>	Node<K,V>[] t;
1274	>	if ((t = table) != null) {
1275	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1276	>	for (Node<K,V> p; (p = it.advance()) != null; )
1277	>	h += p.key.hashCode() ^ p.val.hashCode();
1278	>	}
1279		return h;
1280		}
1281
1282		/**
1283	<	* Return the segment that should be used for key with given hash
1283	>	* Returns a string representation of this map.  The string
1284	>	* representation consists of a list of key-value mappings (in no
1285	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1286	>	* mappings are separated by the characters {@code ", "} (comma
1287	>	* and space).  Each key-value mapping is rendered as the key
1288	>	* followed by an equals sign ("{@code =}") followed by the
1289	>	* associated value.
1290	>	*
1291	>	* @return a string representation of this map
1292		*/
1293	<	private Segment<K,V> segmentFor(int hash) {
1294	<	return (Segment<K,V>) segments[(hash >>> segmentShift) & segmentMask];
1293	>	public String toString() {
1294	>	Node<K,V>[] t;
1295	>	int f = (t = table) == null ? 0 : t.length;
1296	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1297	>	StringBuilder sb = new StringBuilder();
1298	>	sb.append('{');
1299	>	Node<K,V> p;
1300	>	if ((p = it.advance()) != null) {
1301	>	for (;;) {
1302	>	K k = p.key;
1303	>	V v = p.val;
1304	>	sb.append(k == this ? "(this Map)" : k);
1305	>	sb.append('=');
1306	>	sb.append(v == this ? "(this Map)" : v);
1307	>	if ((p = it.advance()) == null)
1308	>	break;
1309	>	sb.append(',').append(' ');
1310	>	}
1311	>	}
1312	>	return sb.append('}').toString();
1313		}
1314
1315	<	/* ---------------- Inner Classes -------------- */
1315	>	/**
1316	>	* Compares the specified object with this map for equality.
1317	>	* Returns {@code true} if the given object is a map with the same
1318	>	* mappings as this map.  This operation may return misleading
1319	>	* results if either map is concurrently modified during execution
1320	>	* of this method.
1321	>	*
1322	>	* @param o object to be compared for equality with this map
1323	>	* @return {@code true} if the specified object is equal to this map
1324	>	*/
1325	>	public boolean equals(Object o) {
1326	>	if (o != this) {
1327	>	if (!(o instanceof Map))
1328	>	return false;
1329	>	Map<?,?> m = (Map<?,?>) o;
1330	>	Node<K,V>[] t;
1331	>	int f = (t = table) == null ? 0 : t.length;
1332	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1333	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1334	>	V val = p.val;
1335	>	Object v = m.get(p.key);
1336	>	if (v == null || (v != val && !v.equals(val)))
1337	>	return false;
1338	>	}
1339	>	for (Map.Entry<?,?> e : m.entrySet()) {
1340	>	Object mk, mv, v;
1341	>	if ((mk = e.getKey()) == null ||
1342	>	(mv = e.getValue()) == null ||
1343	>	(v = get(mk)) == null ||
1344	>	(mv != v && !mv.equals(v)))
1345	>	return false;
1346	>	}
1347	>	}
1348	>	return true;
1349	>	}
1350
1351		/**
1352	<	* Segments are specialized versions of hash tables.  This
1353	<	* subclasses from ReentrantLock opportunistically, just to
1354	<	* simplify some locking and avoid separate construction.
1355	<	**/
1356	<	private static final class Segment<K,V> extends ReentrantLock implements Serializable {
1352	>	* Stripped-down version of helper class used in previous version,
1353	>	* declared for the sake of serialization compatibility.
1354	>	*/
1355	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1356	>	private static final long serialVersionUID = 2249069246763182397L;
1357	>	final float loadFactor;
1358	>	Segment(float lf) { this.loadFactor = lf; }
1359	>	}
1360	>
1361	>	/**
1362	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1363	>	* stream (i.e., serializes it).
1364	>	* @param s the stream
1365	>	* @throws java.io.IOException if an I/O error occurs
1366	>	* @serialData
1367	>	* the serialized fields, followed by the key (Object) and value
1368	>	* (Object) for each key-value mapping, followed by a null pair.
1369	>	* The key-value mappings are emitted in no particular order.
1370	>	*/
1371	>	private void writeObject(java.io.ObjectOutputStream s)
1372	>	throws java.io.IOException {
1373	>	// For serialization compatibility
1374	>	// Emulate segment calculation from previous version of this class
1375	>	int sshift = 0;
1376	>	int ssize = 1;
1377	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1378	>	++sshift;
1379	>	ssize <<= 1;
1380	>	}
1381	>	int segmentShift = 32 - sshift;
1382	>	int segmentMask = ssize - 1;
1383	>	@SuppressWarnings("unchecked")
1384	>	Segment<K,V>[] segments = (Segment<K,V>[])
1385	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1386	>	for (int i = 0; i < segments.length; ++i)
1387	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1388	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1389	>	streamFields.put("segments", segments);
1390	>	streamFields.put("segmentShift", segmentShift);
1391	>	streamFields.put("segmentMask", segmentMask);
1392	>	s.writeFields();
1393	>
1394	>	Node<K,V>[] t;
1395	>	if ((t = table) != null) {
1396	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1397	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1398	>	s.writeObject(p.key);
1399	>	s.writeObject(p.val);
1400	>	}
1401	>	}
1402	>	s.writeObject(null);
1403	>	s.writeObject(null);
1404	>	}
1405	>
1406	>	/**
1407	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1408	>	* @param s the stream
1409	>	* @throws ClassNotFoundException if the class of a serialized object
1410	>	*         could not be found
1411	>	* @throws java.io.IOException if an I/O error occurs
1412	>	*/
1413	>	private void readObject(java.io.ObjectInputStream s)
1414	>	throws java.io.IOException, ClassNotFoundException {
1415		/*
1416	<	* Segments maintain a table of entry lists that are ALWAYS
1417	<	* kept in a consistent state, so can be read without locking.
1418	<	* Next fields of nodes are immutable (final).  All list
1419	<	* additions are performed at the front of each bin. This
1420	<	* makes it easy to check changes, and also fast to traverse.
150	<	* When nodes would otherwise be changed, new nodes are
151	<	* created to replace them. This works well for hash tables
152	<	* since the bin lists tend to be short. (The average length
153	<	* is less than two for the default load factor threshold.)
154	<	*
155	<	* Read operations can thus proceed without locking, but rely
156	<	* on a memory barrier to ensure that completed write
157	<	* operations performed by other threads are
158	<	* noticed. Conveniently, the "count" field, tracking the
159	<	* number of elements, can also serve as the volatile variable
160	<	* providing proper read/write barriers. This is convenient
161	<	* because this field needs to be read in many read operations
162	<	* anyway. The use of volatiles for this purpose is only
163	<	* guaranteed to work in accord with reuirements in
164	<	* multithreaded environments when run on JVMs conforming to
165	<	* the clarified JSR133 memory model specification.  This true
166	<	* for hotspot as of release 1.4.
167	<	*
168	<	* Implementors note. The basic rules for all this are:
169	<	*
170	<	*   - All unsynchronized read operations must first read the
171	<	*     "count" field, and should not look at table entries if
172	<	*     it is 0.
173	<	*
174	<	*   - All synchronized write operations should write to
175	<	*     the "count" field after updating. The operations must not
176	<	*     take any action that could even momentarily cause
177	<	*     a concurrent read operation to see inconsistent
178	<	*     data. This is made easier by the nature of the read
179	<	*     operations in Map. For example, no operation
180	<	*     can reveal that the table has grown but the threshold
181	<	*     has not yet been updated, so there are no atomicity
182	<	*     requirements for this with respect to reads.
183	<	*
184	<	* As a guide, all critical volatile reads and writes are marked
185	<	* in code comments.
1416	>	* To improve performance in typical cases, we create nodes
1417	>	* while reading, then place in table once size is known.
1418	>	* However, we must also validate uniqueness and deal with
1419	>	* overpopulated bins while doing so, which requires
1420	>	* specialized versions of putVal mechanics.
1421		*/
1422	+	sizeCtl = -1; // force exclusion for table construction
1423	+	s.defaultReadObject();
1424	+	long size = 0L;
1425	+	Node<K,V> p = null;
1426	+	for (;;) {
1427	+	@SuppressWarnings("unchecked")
1428	+	K k = (K) s.readObject();
1429	+	@SuppressWarnings("unchecked")
1430	+	V v = (V) s.readObject();
1431	+	if (k != null && v != null) {
1432	+	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1433	+	++size;
1434	+	}
1435	+	else
1436	+	break;
1437	+	}
1438	+	if (size == 0L)
1439	+	sizeCtl = 0;
1440	+	else {
1441	+	int n;
1442	+	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1443	+	n = MAXIMUM_CAPACITY;
1444	+	else {
1445	+	int sz = (int)size;
1446	+	n = tableSizeFor(sz + (sz >>> 1) + 1);
1447	+	}
1448	+	@SuppressWarnings("unchecked")
1449	+	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1450	+	int mask = n - 1;
1451	+	long added = 0L;
1452	+	while (p != null) {
1453	+	boolean insertAtFront;
1454	+	Node<K,V> next = p.next, first;
1455	+	int h = p.hash, j = h & mask;
1456	+	if ((first = tabAt(tab, j)) == null)
1457	+	insertAtFront = true;
1458	+	else {
1459	+	K k = p.key;
1460	+	if (first.hash < 0) {
1461	+	TreeBin<K,V> t = (TreeBin<K,V>)first;
1462	+	if (t.putTreeVal(h, k, p.val) == null)
1463	+	++added;
1464	+	insertAtFront = false;
1465	+	}
1466	+	else {
1467	+	int binCount = 0;
1468	+	insertAtFront = true;
1469	+	Node<K,V> q; K qk;
1470	+	for (q = first; q != null; q = q.next) {
1471	+	if (q.hash == h &&
1472	+	((qk = q.key) == k ||
1473	+	(qk != null && k.equals(qk)))) {
1474	+	insertAtFront = false;
1475	+	break;
1476	+	}
1477	+	++binCount;
1478	+	}
1479	+	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1480	+	insertAtFront = false;
1481	+	++added;
1482	+	p.next = first;
1483	+	TreeNode<K,V> hd = null, tl = null;
1484	+	for (q = p; q != null; q = q.next) {
1485	+	TreeNode<K,V> t = new TreeNode<K,V>
1486	+	(q.hash, q.key, q.val, null, null);
1487	+	if ((t.prev = tl) == null)
1488	+	hd = t;
1489	+	else
1490	+	tl.next = t;
1491	+	tl = t;
1492	+	}
1493	+	setTabAt(tab, j, new TreeBin<K,V>(hd));
1494	+	}
1495	+	}
1496	+	}
1497	+	if (insertAtFront) {
1498	+	++added;
1499	+	p.next = first;
1500	+	setTabAt(tab, j, p);
1501	+	}
1502	+	p = next;
1503	+	}
1504	+	table = tab;
1505	+	sizeCtl = n - (n >>> 2);
1506	+	baseCount = added;
1507	+	}
1508	+	}
1509
1510	<	/**
1511	<	* The number of elements in this segment's region.
1512	<	**/
1513	<	transient volatile int count;
1510	>	// ConcurrentMap methods
1511	>
1512	>	/**
1513	>	* {@inheritDoc}
1514	>	*
1515	>	* @return the previous value associated with the specified key,
1516	>	*         or {@code null} if there was no mapping for the key
1517	>	* @throws NullPointerException if the specified key or value is null
1518	>	*/
1519	>	public V putIfAbsent(K key, V value) {
1520	>	return putVal(key, value, true);
1521	>	}
1522	>
1523	>	/**
1524	>	* {@inheritDoc}
1525	>	*
1526	>	* @throws NullPointerException if the specified key is null
1527	>	*/
1528	>	public boolean remove(Object key, Object value) {
1529	>	if (key == null)
1530	>	throw new NullPointerException();
1531	>	return value != null && replaceNode(key, null, value) != null;
1532	>	}
1533	>
1534	>	/**
1535	>	* {@inheritDoc}
1536	>	*
1537	>	* @throws NullPointerException if any of the arguments are null
1538	>	*/
1539	>	public boolean replace(K key, V oldValue, V newValue) {
1540	>	if (key == null || oldValue == null || newValue == null)
1541	>	throw new NullPointerException();
1542	>	return replaceNode(key, newValue, oldValue) != null;
1543	>	}
1544	>
1545	>	/**
1546	>	* {@inheritDoc}
1547	>	*
1548	>	* @return the previous value associated with the specified key,
1549	>	*         or {@code null} if there was no mapping for the key
1550	>	* @throws NullPointerException if the specified key or value is null
1551	>	*/
1552	>	public V replace(K key, V value) {
1553	>	if (key == null || value == null)
1554	>	throw new NullPointerException();
1555	>	return replaceNode(key, value, null);
1556	>	}
1557	>
1558	>	// Overrides of JDK8+ Map extension method defaults
1559	>
1560	>	/**
1561	>	* Returns the value to which the specified key is mapped, or the
1562	>	* given default value if this map contains no mapping for the
1563	>	* key.
1564	>	*
1565	>	* @param key the key whose associated value is to be returned
1566	>	* @param defaultValue the value to return if this map contains
1567	>	* no mapping for the given key
1568	>	* @return the mapping for the key, if present; else the default value
1569	>	* @throws NullPointerException if the specified key is null
1570	>	*/
1571	>	public V getOrDefault(Object key, V defaultValue) {
1572	>	V v;
1573	>	return (v = get(key)) == null ? defaultValue : v;
1574	>	}
1575	>
1576	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1577	>	if (action == null) throw new NullPointerException();
1578	>	Node<K,V>[] t;
1579	>	if ((t = table) != null) {
1580	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1581	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1582	>	action.accept(p.key, p.val);
1583	>	}
1584	>	}
1585	>	}
1586	>
1587	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1588	>	if (function == null) throw new NullPointerException();
1589	>	Node<K,V>[] t;
1590	>	if ((t = table) != null) {
1591	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1592	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1593	>	V oldValue = p.val;
1594	>	for (K key = p.key;;) {
1595	>	V newValue = function.apply(key, oldValue);
1596	>	if (newValue == null)
1597	>	throw new NullPointerException();
1598	>	if (replaceNode(key, newValue, oldValue) != null ||
1599	>	(oldValue = get(key)) == null)
1600	>	break;
1601	>	}
1602	>	}
1603	>	}
1604	>	}
1605	>
1606	>	/**
1607	>	* Helper method for EntrySetView.removeIf.
1608	>	*/
1609	>	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1610	>	if (function == null) throw new NullPointerException();
1611	>	Node<K,V>[] t;
1612	>	boolean removed = false;
1613	>	if ((t = table) != null) {
1614	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1615	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1616	>	K k = p.key;
1617	>	V v = p.val;
1618	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1619	>	if (function.test(e) && replaceNode(k, null, v) != null)
1620	>	removed = true;
1621	>	}
1622	>	}
1623	>	return removed;
1624	>	}
1625	>
1626	>	/**
1627	>	* Helper method for ValuesView.removeIf.
1628	>	*/
1629	>	boolean removeValueIf(Predicate<? super V> function) {
1630	>	if (function == null) throw new NullPointerException();
1631	>	Node<K,V>[] t;
1632	>	boolean removed = false;
1633	>	if ((t = table) != null) {
1634	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1635	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1636	>	K k = p.key;
1637	>	V v = p.val;
1638	>	if (function.test(v) && replaceNode(k, null, v) != null)
1639	>	removed = true;
1640	>	}
1641	>	}
1642	>	return removed;
1643	>	}
1644	>
1645	>	/**
1646	>	* If the specified key is not already associated with a value,
1647	>	* attempts to compute its value using the given mapping function
1648	>	* and enters it into this map unless {@code null}.  The entire
1649	>	* method invocation is performed atomically, so the function is
1650	>	* applied at most once per key.  Some attempted update operations
1651	>	* on this map by other threads may be blocked while computation
1652	>	* is in progress, so the computation should be short and simple,
1653	>	* and must not attempt to update any other mappings of this map.
1654	>	*
1655	>	* @param key key with which the specified value is to be associated
1656	>	* @param mappingFunction the function to compute a value
1657	>	* @return the current (existing or computed) value associated with
1658	>	*         the specified key, or null if the computed value is null
1659	>	* @throws NullPointerException if the specified key or mappingFunction
1660	>	*         is null
1661	>	* @throws IllegalStateException if the computation detectably
1662	>	*         attempts a recursive update to this map that would
1663	>	*         otherwise never complete
1664	>	* @throws RuntimeException or Error if the mappingFunction does so,
1665	>	*         in which case the mapping is left unestablished
1666	>	*/
1667	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1668	>	if (key == null || mappingFunction == null)
1669	>	throw new NullPointerException();
1670	>	int h = spread(key.hashCode());
1671	>	V val = null;
1672	>	int binCount = 0;
1673	>	for (Node<K,V>[] tab = table;;) {
1674	>	Node<K,V> f; int n, i, fh;
1675	>	if (tab == null || (n = tab.length) == 0)
1676	>	tab = initTable();
1677	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1678	>	Node<K,V> r = new ReservationNode<K,V>();
1679	>	synchronized (r) {
1680	>	if (casTabAt(tab, i, null, r)) {
1681	>	binCount = 1;
1682	>	Node<K,V> node = null;
1683	>	try {
1684	>	if ((val = mappingFunction.apply(key)) != null)
1685	>	node = new Node<K,V>(h, key, val);
1686	>	} finally {
1687	>	setTabAt(tab, i, node);
1688	>	}
1689	>	}
1690	>	}
1691	>	if (binCount != 0)
1692	>	break;
1693	>	}
1694	>	else if ((fh = f.hash) == MOVED)
1695	>	tab = helpTransfer(tab, f);
1696	>	else {
1697	>	boolean added = false;
1698	>	synchronized (f) {
1699	>	if (tabAt(tab, i) == f) {
1700	>	if (fh >= 0) {
1701	>	binCount = 1;
1702	>	for (Node<K,V> e = f;; ++binCount) {
1703	>	K ek;
1704	>	if (e.hash == h &&
1705	>	((ek = e.key) == key ||
1706	>	(ek != null && key.equals(ek)))) {
1707	>	val = e.val;
1708	>	break;
1709	>	}
1710	>	Node<K,V> pred = e;
1711	>	if ((e = e.next) == null) {
1712	>	if ((val = mappingFunction.apply(key)) != null) {
1713	>	if (pred.next != null)
1714	>	throw new IllegalStateException("Recursive update");
1715	>	added = true;
1716	>	pred.next = new Node<K,V>(h, key, val);
1717	>	}
1718	>	break;
1719	>	}
1720	>	}
1721	>	}
1722	>	else if (f instanceof TreeBin) {
1723	>	binCount = 2;
1724	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1725	>	TreeNode<K,V> r, p;
1726	>	if ((r = t.root) != null &&
1727	>	(p = r.findTreeNode(h, key, null)) != null)
1728	>	val = p.val;
1729	>	else if ((val = mappingFunction.apply(key)) != null) {
1730	>	added = true;
1731	>	t.putTreeVal(h, key, val);
1732	>	}
1733	>	}
1734	>	else if (f instanceof ReservationNode)
1735	>	throw new IllegalStateException("Recursive update");
1736	>	}
1737	>	}
1738	>	if (binCount != 0) {
1739	>	if (binCount >= TREEIFY_THRESHOLD)
1740	>	treeifyBin(tab, i);
1741	>	if (!added)
1742	>	return val;
1743	>	break;
1744	>	}
1745	>	}
1746	>	}
1747	>	if (val != null)
1748	>	addCount(1L, binCount);
1749	>	return val;
1750	>	}
1751	>
1752	>	/**
1753	>	* If the value for the specified key is present, attempts to
1754	>	* compute a new mapping given the key and its current mapped
1755	>	* value.  The entire method invocation is performed atomically.
1756	>	* Some attempted update operations on this map by other threads
1757	>	* may be blocked while computation is in progress, so the
1758	>	* computation should be short and simple, and must not attempt to
1759	>	* update any other mappings of this map.
1760	>	*
1761	>	* @param key key with which a value may be associated
1762	>	* @param remappingFunction the function to compute a value
1763	>	* @return the new value associated with the specified key, or null if none
1764	>	* @throws NullPointerException if the specified key or remappingFunction
1765	>	*         is null
1766	>	* @throws IllegalStateException if the computation detectably
1767	>	*         attempts a recursive update to this map that would
1768	>	*         otherwise never complete
1769	>	* @throws RuntimeException or Error if the remappingFunction does so,
1770	>	*         in which case the mapping is unchanged
1771	>	*/
1772	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1773	>	if (key == null || remappingFunction == null)
1774	>	throw new NullPointerException();
1775	>	int h = spread(key.hashCode());
1776	>	V val = null;
1777	>	int delta = 0;
1778	>	int binCount = 0;
1779	>	for (Node<K,V>[] tab = table;;) {
1780	>	Node<K,V> f; int n, i, fh;
1781	>	if (tab == null || (n = tab.length) == 0)
1782	>	tab = initTable();
1783	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1784	>	break;
1785	>	else if ((fh = f.hash) == MOVED)
1786	>	tab = helpTransfer(tab, f);
1787	>	else {
1788	>	synchronized (f) {
1789	>	if (tabAt(tab, i) == f) {
1790	>	if (fh >= 0) {
1791	>	binCount = 1;
1792	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1793	>	K ek;
1794	>	if (e.hash == h &&
1795	>	((ek = e.key) == key ||
1796	>	(ek != null && key.equals(ek)))) {
1797	>	val = remappingFunction.apply(key, e.val);
1798	>	if (val != null)
1799	>	e.val = val;
1800	>	else {
1801	>	delta = -1;
1802	>	Node<K,V> en = e.next;
1803	>	if (pred != null)
1804	>	pred.next = en;
1805	>	else
1806	>	setTabAt(tab, i, en);
1807	>	}
1808	>	break;
1809	>	}
1810	>	pred = e;
1811	>	if ((e = e.next) == null)
1812	>	break;
1813	>	}
1814	>	}
1815	>	else if (f instanceof TreeBin) {
1816	>	binCount = 2;
1817	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1818	>	TreeNode<K,V> r, p;
1819	>	if ((r = t.root) != null &&
1820	>	(p = r.findTreeNode(h, key, null)) != null) {
1821	>	val = remappingFunction.apply(key, p.val);
1822	>	if (val != null)
1823	>	p.val = val;
1824	>	else {
1825	>	delta = -1;
1826	>	if (t.removeTreeNode(p))
1827	>	setTabAt(tab, i, untreeify(t.first));
1828	>	}
1829	>	}
1830	>	}
1831	>	else if (f instanceof ReservationNode)
1832	>	throw new IllegalStateException("Recursive update");
1833	>	}
1834	>	}
1835	>	if (binCount != 0)
1836	>	break;
1837	>	}
1838	>	}
1839	>	if (delta != 0)
1840	>	addCount((long)delta, binCount);
1841	>	return val;
1842	>	}
1843	>
1844	>	/**
1845	>	* Attempts to compute a mapping for the specified key and its
1846	>	* current mapped value (or {@code null} if there is no current
1847	>	* mapping). The entire method invocation is performed atomically.
1848	>	* Some attempted update operations on this map by other threads
1849	>	* may be blocked while computation is in progress, so the
1850	>	* computation should be short and simple, and must not attempt to
1851	>	* update any other mappings of this Map.
1852	>	*
1853	>	* @param key key with which the specified value is to be associated
1854	>	* @param remappingFunction the function to compute a value
1855	>	* @return the new value associated with the specified key, or null if none
1856	>	* @throws NullPointerException if the specified key or remappingFunction
1857	>	*         is null
1858	>	* @throws IllegalStateException if the computation detectably
1859	>	*         attempts a recursive update to this map that would
1860	>	*         otherwise never complete
1861	>	* @throws RuntimeException or Error if the remappingFunction does so,
1862	>	*         in which case the mapping is unchanged
1863	>	*/
1864	>	public V compute(K key,
1865	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1866	>	if (key == null || remappingFunction == null)
1867	>	throw new NullPointerException();
1868	>	int h = spread(key.hashCode());
1869	>	V val = null;
1870	>	int delta = 0;
1871	>	int binCount = 0;
1872	>	for (Node<K,V>[] tab = table;;) {
1873	>	Node<K,V> f; int n, i, fh;
1874	>	if (tab == null || (n = tab.length) == 0)
1875	>	tab = initTable();
1876	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1877	>	Node<K,V> r = new ReservationNode<K,V>();
1878	>	synchronized (r) {
1879	>	if (casTabAt(tab, i, null, r)) {
1880	>	binCount = 1;
1881	>	Node<K,V> node = null;
1882	>	try {
1883	>	if ((val = remappingFunction.apply(key, null)) != null) {
1884	>	delta = 1;
1885	>	node = new Node<K,V>(h, key, val);
1886	>	}
1887	>	} finally {
1888	>	setTabAt(tab, i, node);
1889	>	}
1890	>	}
1891	>	}
1892	>	if (binCount != 0)
1893	>	break;
1894	>	}
1895	>	else if ((fh = f.hash) == MOVED)
1896	>	tab = helpTransfer(tab, f);
1897	>	else {
1898	>	synchronized (f) {
1899	>	if (tabAt(tab, i) == f) {
1900	>	if (fh >= 0) {
1901	>	binCount = 1;
1902	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1903	>	K ek;
1904	>	if (e.hash == h &&
1905	>	((ek = e.key) == key ||
1906	>	(ek != null && key.equals(ek)))) {
1907	>	val = remappingFunction.apply(key, e.val);
1908	>	if (val != null)
1909	>	e.val = val;
1910	>	else {
1911	>	delta = -1;
1912	>	Node<K,V> en = e.next;
1913	>	if (pred != null)
1914	>	pred.next = en;
1915	>	else
1916	>	setTabAt(tab, i, en);
1917	>	}
1918	>	break;
1919	>	}
1920	>	pred = e;
1921	>	if ((e = e.next) == null) {
1922	>	val = remappingFunction.apply(key, null);
1923	>	if (val != null) {
1924	>	if (pred.next != null)
1925	>	throw new IllegalStateException("Recursive update");
1926	>	delta = 1;
1927	>	pred.next = new Node<K,V>(h, key, val);
1928	>	}
1929	>	break;
1930	>	}
1931	>	}
1932	>	}
1933	>	else if (f instanceof TreeBin) {
1934	>	binCount = 1;
1935	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1936	>	TreeNode<K,V> r, p;
1937	>	if ((r = t.root) != null)
1938	>	p = r.findTreeNode(h, key, null);
1939	>	else
1940	>	p = null;
1941	>	V pv = (p == null) ? null : p.val;
1942	>	val = remappingFunction.apply(key, pv);
1943	>	if (val != null) {
1944	>	if (p != null)
1945	>	p.val = val;
1946	>	else {
1947	>	delta = 1;
1948	>	t.putTreeVal(h, key, val);
1949	>	}
1950	>	}
1951	>	else if (p != null) {
1952	>	delta = -1;
1953	>	if (t.removeTreeNode(p))
1954	>	setTabAt(tab, i, untreeify(t.first));
1955	>	}
1956	>	}
1957	>	else if (f instanceof ReservationNode)
1958	>	throw new IllegalStateException("Recursive update");
1959	>	}
1960	>	}
1961	>	if (binCount != 0) {
1962	>	if (binCount >= TREEIFY_THRESHOLD)
1963	>	treeifyBin(tab, i);
1964	>	break;
1965	>	}
1966	>	}
1967	>	}
1968	>	if (delta != 0)
1969	>	addCount((long)delta, binCount);
1970	>	return val;
1971	>	}
1972	>
1973	>	/**
1974	>	* If the specified key is not already associated with a
1975	>	* (non-null) value, associates it with the given value.
1976	>	* Otherwise, replaces the value with the results of the given
1977	>	* remapping function, or removes if {@code null}. The entire
1978	>	* method invocation is performed atomically.  Some attempted
1979	>	* update operations on this map by other threads may be blocked
1980	>	* while computation is in progress, so the computation should be
1981	>	* short and simple, and must not attempt to update any other
1982	>	* mappings of this Map.
1983	>	*
1984	>	* @param key key with which the specified value is to be associated
1985	>	* @param value the value to use if absent
1986	>	* @param remappingFunction the function to recompute a value if present
1987	>	* @return the new value associated with the specified key, or null if none
1988	>	* @throws NullPointerException if the specified key or the
1989	>	*         remappingFunction is null
1990	>	* @throws RuntimeException or Error if the remappingFunction does so,
1991	>	*         in which case the mapping is unchanged
1992	>	*/
1993	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1994	>	if (key == null || value == null || remappingFunction == null)
1995	>	throw new NullPointerException();
1996	>	int h = spread(key.hashCode());
1997	>	V val = null;
1998	>	int delta = 0;
1999	>	int binCount = 0;
2000	>	for (Node<K,V>[] tab = table;;) {
2001	>	Node<K,V> f; int n, i, fh;
2002	>	if (tab == null || (n = tab.length) == 0)
2003	>	tab = initTable();
2004	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2005	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2006	>	delta = 1;
2007	>	val = value;
2008	>	break;
2009	>	}
2010	>	}
2011	>	else if ((fh = f.hash) == MOVED)
2012	>	tab = helpTransfer(tab, f);
2013	>	else {
2014	>	synchronized (f) {
2015	>	if (tabAt(tab, i) == f) {
2016	>	if (fh >= 0) {
2017	>	binCount = 1;
2018	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
2019	>	K ek;
2020	>	if (e.hash == h &&
2021	>	((ek = e.key) == key ||
2022	>	(ek != null && key.equals(ek)))) {
2023	>	val = remappingFunction.apply(e.val, value);
2024	>	if (val != null)
2025	>	e.val = val;
2026	>	else {
2027	>	delta = -1;
2028	>	Node<K,V> en = e.next;
2029	>	if (pred != null)
2030	>	pred.next = en;
2031	>	else
2032	>	setTabAt(tab, i, en);
2033	>	}
2034	>	break;
2035	>	}
2036	>	pred = e;
2037	>	if ((e = e.next) == null) {
2038	>	delta = 1;
2039	>	val = value;
2040	>	pred.next = new Node<K,V>(h, key, val);
2041	>	break;
2042	>	}
2043	>	}
2044	>	}
2045	>	else if (f instanceof TreeBin) {
2046	>	binCount = 2;
2047	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2048	>	TreeNode<K,V> r = t.root;
2049	>	TreeNode<K,V> p = (r == null) ? null :
2050	>	r.findTreeNode(h, key, null);
2051	>	val = (p == null) ? value :
2052	>	remappingFunction.apply(p.val, value);
2053	>	if (val != null) {
2054	>	if (p != null)
2055	>	p.val = val;
2056	>	else {
2057	>	delta = 1;
2058	>	t.putTreeVal(h, key, val);
2059	>	}
2060	>	}
2061	>	else if (p != null) {
2062	>	delta = -1;
2063	>	if (t.removeTreeNode(p))
2064	>	setTabAt(tab, i, untreeify(t.first));
2065	>	}
2066	>	}
2067	>	else if (f instanceof ReservationNode)
2068	>	throw new IllegalStateException("Recursive update");
2069	>	}
2070	>	}
2071	>	if (binCount != 0) {
2072	>	if (binCount >= TREEIFY_THRESHOLD)
2073	>	treeifyBin(tab, i);
2074	>	break;
2075	>	}
2076	>	}
2077	>	}
2078	>	if (delta != 0)
2079	>	addCount((long)delta, binCount);
2080	>	return val;
2081	>	}
2082	>
2083	>	// Hashtable legacy methods
2084	>
2085	>	/**
2086	>	* Tests if some key maps into the specified value in this table.
2087	>	*
2088	>	* <p>Note that this method is identical in functionality to
2089	>	* {@link #containsValue(Object)}, and exists solely to ensure
2090	>	* full compatibility with class {@link java.util.Hashtable},
2091	>	* which supported this method prior to introduction of the
2092	>	* Java Collections Framework.
2093	>	*
2094	>	* @param  value a value to search for
2095	>	* @return {@code true} if and only if some key maps to the
2096	>	*         {@code value} argument in this table as
2097	>	*         determined by the {@code equals} method;
2098	>	*         {@code false} otherwise
2099	>	* @throws NullPointerException if the specified value is null
2100	>	*/
2101	>	public boolean contains(Object value) {
2102	>	return containsValue(value);
2103	>	}
2104	>
2105	>	/**
2106	>	* Returns an enumeration of the keys in this table.
2107	>	*
2108	>	* @return an enumeration of the keys in this table
2109	>	* @see #keySet()
2110	>	*/
2111	>	public Enumeration<K> keys() {
2112	>	Node<K,V>[] t;
2113	>	int f = (t = table) == null ? 0 : t.length;
2114	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2115	>	}
2116	>
2117	>	/**
2118	>	* Returns an enumeration of the values in this table.
2119	>	*
2120	>	* @return an enumeration of the values in this table
2121	>	* @see #values()
2122	>	*/
2123	>	public Enumeration<V> elements() {
2124	>	Node<K,V>[] t;
2125	>	int f = (t = table) == null ? 0 : t.length;
2126	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2127	>	}
2128	>
2129	>	// ConcurrentHashMap-only methods
2130	>
2131	>	/**
2132	>	* Returns the number of mappings. This method should be used
2133	>	* instead of {@link #size} because a ConcurrentHashMap may
2134	>	* contain more mappings than can be represented as an int. The
2135	>	* value returned is an estimate; the actual count may differ if
2136	>	* there are concurrent insertions or removals.
2137	>	*
2138	>	* @return the number of mappings
2139	>	* @since 1.8
2140	>	*/
2141	>	public long mappingCount() {
2142	>	long n = sumCount();
2143	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2144	>	}
2145	>
2146	>	/**
2147	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2148	>	* from the given type to {@code Boolean.TRUE}.
2149	>	*
2150	>	* @param <K> the element type of the returned set
2151	>	* @return the new set
2152	>	* @since 1.8
2153	>	*/
2154	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2155	>	return new KeySetView<K,Boolean>
2156	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2157	>	}
2158	>
2159	>	/**
2160	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2161	>	* from the given type to {@code Boolean.TRUE}.
2162	>	*
2163	>	* @param initialCapacity The implementation performs internal
2164	>	* sizing to accommodate this many elements.
2165	>	* @param <K> the element type of the returned set
2166	>	* @return the new set
2167	>	* @throws IllegalArgumentException if the initial capacity of
2168	>	* elements is negative
2169	>	* @since 1.8
2170	>	*/
2171	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2172	>	return new KeySetView<K,Boolean>
2173	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2174	>	}
2175	>
2176	>	/**
2177	>	* Returns a {@link Set} view of the keys in this map, using the
2178	>	* given common mapped value for any additions (i.e., {@link
2179	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2180	>	* This is of course only appropriate if it is acceptable to use
2181	>	* the same value for all additions from this view.
2182	>	*
2183	>	* @param mappedValue the mapped value to use for any additions
2184	>	* @return the set view
2185	>	* @throws NullPointerException if the mappedValue is null
2186	>	*/
2187	>	public KeySetView<K,V> keySet(V mappedValue) {
2188	>	if (mappedValue == null)
2189	>	throw new NullPointerException();
2190	>	return new KeySetView<K,V>(this, mappedValue);
2191	>	}
2192	>
2193	>	/* ---------------- Special Nodes -------------- */
2194	>
2195	>	/**
2196	>	* A node inserted at head of bins during transfer operations.
2197	>	*/
2198	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2199	>	final Node<K,V>[] nextTable;
2200	>	ForwardingNode(Node<K,V>[] tab) {
2201	>	super(MOVED, null, null);
2202	>	this.nextTable = tab;
2203	>	}
2204	>
2205	>	Node<K,V> find(int h, Object k) {
2206	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2207	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2208	>	Node<K,V> e; int n;
2209	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2210	>	(e = tabAt(tab, (n - 1) & h)) == null)
2211	>	return null;
2212	>	for (;;) {
2213	>	int eh; K ek;
2214	>	if ((eh = e.hash) == h &&
2215	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2216	>	return e;
2217	>	if (eh < 0) {
2218	>	if (e instanceof ForwardingNode) {
2219	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2220	>	continue outer;
2221	>	}
2222	>	else
2223	>	return e.find(h, k);
2224	>	}
2225	>	if ((e = e.next) == null)
2226	>	return null;
2227	>	}
2228	>	}
2229	>	}
2230	>	}
2231	>
2232	>	/**
2233	>	* A place-holder node used in computeIfAbsent and compute.
2234	>	*/
2235	>	static final class ReservationNode<K,V> extends Node<K,V> {
2236	>	ReservationNode() {
2237	>	super(RESERVED, null, null);
2238	>	}
2239	>
2240	>	Node<K,V> find(int h, Object k) {
2241	>	return null;
2242	>	}
2243	>	}
2244	>
2245	>	/* ---------------- Table Initialization and Resizing -------------- */
2246	>
2247	>	/**
2248	>	* Returns the stamp bits for resizing a table of size n.
2249	>	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2250	>	*/
2251	>	static final int resizeStamp(int n) {
2252	>	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2253	>	}
2254	>
2255	>	/**
2256	>	* Initializes table, using the size recorded in sizeCtl.
2257	>	*/
2258	>	private final Node<K,V>[] initTable() {
2259	>	Node<K,V>[] tab; int sc;
2260	>	while ((tab = table) == null || tab.length == 0) {
2261	>	if ((sc = sizeCtl) < 0)
2262	>	Thread.yield(); // lost initialization race; just spin
2263	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2264	>	try {
2265	>	if ((tab = table) == null || tab.length == 0) {
2266	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2267	>	@SuppressWarnings("unchecked")
2268	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2269	>	table = tab = nt;
2270	>	sc = n - (n >>> 2);
2271	>	}
2272	>	} finally {
2273	>	sizeCtl = sc;
2274	>	}
2275	>	break;
2276	>	}
2277	>	}
2278	>	return tab;
2279	>	}
2280	>
2281	>	/**
2282	>	* Adds to count, and if table is too small and not already
2283	>	* resizing, initiates transfer. If already resizing, helps
2284	>	* perform transfer if work is available.  Rechecks occupancy
2285	>	* after a transfer to see if another resize is already needed
2286	>	* because resizings are lagging additions.
2287	>	*
2288	>	* @param x the count to add
2289	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2290	>	*/
2291	>	private final void addCount(long x, int check) {
2292	>	CounterCell[] as; long b, s;
2293	>	if ((as = counterCells) != null ||
2294	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2295	>	CounterCell a; long v; int m;
2296	>	boolean uncontended = true;
2297	>	if (as == null || (m = as.length - 1) < 0 ||
2298	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2299	>	!(uncontended =
2300	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2301	>	fullAddCount(x, uncontended);
2302	>	return;
2303	>	}
2304	>	if (check <= 1)
2305	>	return;
2306	>	s = sumCount();
2307	>	}
2308	>	if (check >= 0) {
2309	>	Node<K,V>[] tab, nt; int n, sc;
2310	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2311	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2312	>	int rs = resizeStamp(n);
2313	>	if (sc < 0) {
2314	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2315	>	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2316	>	transferIndex <= 0)
2317	>	break;
2318	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2319	>	transfer(tab, nt);
2320	>	}
2321	>	else if (U.compareAndSwapInt(this, SIZECTL, sc,
2322	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2323	>	transfer(tab, null);
2324	>	s = sumCount();
2325	>	}
2326	>	}
2327	>	}
2328	>
2329	>	/**
2330	>	* Helps transfer if a resize is in progress.
2331	>	*/
2332	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2333	>	Node<K,V>[] nextTab; int sc;
2334	>	if (tab != null && (f instanceof ForwardingNode) &&
2335	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2336	>	int rs = resizeStamp(tab.length);
2337	>	while (nextTab == nextTable && table == tab &&
2338	>	(sc = sizeCtl) < 0) {
2339	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2340	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2341	>	break;
2342	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2343	>	transfer(tab, nextTab);
2344	>	break;
2345	>	}
2346	>	}
2347	>	return nextTab;
2348	>	}
2349	>	return table;
2350	>	}
2351	>
2352	>	/**
2353	>	* Tries to presize table to accommodate the given number of elements.
2354	>	*
2355	>	* @param size number of elements (doesn't need to be perfectly accurate)
2356	>	*/
2357	>	private final void tryPresize(int size) {
2358	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2359	>	tableSizeFor(size + (size >>> 1) + 1);
2360	>	int sc;
2361	>	while ((sc = sizeCtl) >= 0) {
2362	>	Node<K,V>[] tab = table; int n;
2363	>	if (tab == null || (n = tab.length) == 0) {
2364	>	n = (sc > c) ? sc : c;
2365	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2366	>	try {
2367	>	if (table == tab) {
2368	>	@SuppressWarnings("unchecked")
2369	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2370	>	table = nt;
2371	>	sc = n - (n >>> 2);
2372	>	}
2373	>	} finally {
2374	>	sizeCtl = sc;
2375	>	}
2376	>	}
2377	>	}
2378	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2379	>	break;
2380	>	else if (tab == table) {
2381	>	int rs = resizeStamp(n);
2382	>	if (U.compareAndSwapInt(this, SIZECTL, sc,
2383	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2384	>	transfer(tab, null);
2385	>	}
2386	>	}
2387	>	}
2388	>
2389	>	/**
2390	>	* Moves and/or copies the nodes in each bin to new table. See
2391	>	* above for explanation.
2392	>	*/
2393	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2394	>	int n = tab.length, stride;
2395	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2396	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2397	>	if (nextTab == null) {            // initiating
2398	>	try {
2399	>	@SuppressWarnings("unchecked")
2400	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2401	>	nextTab = nt;
2402	>	} catch (Throwable ex) {      // try to cope with OOME
2403	>	sizeCtl = Integer.MAX_VALUE;
2404	>	return;
2405	>	}
2406	>	nextTable = nextTab;
2407	>	transferIndex = n;
2408	>	}
2409	>	int nextn = nextTab.length;
2410	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2411	>	boolean advance = true;
2412	>	boolean finishing = false; // to ensure sweep before committing nextTab
2413	>	for (int i = 0, bound = 0;;) {
2414	>	Node<K,V> f; int fh;
2415	>	while (advance) {
2416	>	int nextIndex, nextBound;
2417	>	if (--i >= bound || finishing)
2418	>	advance = false;
2419	>	else if ((nextIndex = transferIndex) <= 0) {
2420	>	i = -1;
2421	>	advance = false;
2422	>	}
2423	>	else if (U.compareAndSwapInt
2424	>	(this, TRANSFERINDEX, nextIndex,
2425	>	nextBound = (nextIndex > stride ?
2426	>	nextIndex - stride : 0))) {
2427	>	bound = nextBound;
2428	>	i = nextIndex - 1;
2429	>	advance = false;
2430	>	}
2431	>	}
2432	>	if (i < 0 || i >= n || i + n >= nextn) {
2433	>	int sc;
2434	>	if (finishing) {
2435	>	nextTable = null;
2436	>	table = nextTab;
2437	>	sizeCtl = (n << 1) - (n >>> 1);
2438	>	return;
2439	>	}
2440	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2441	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2442	>	return;
2443	>	finishing = advance = true;
2444	>	i = n; // recheck before commit
2445	>	}
2446	>	}
2447	>	else if ((f = tabAt(tab, i)) == null)
2448	>	advance = casTabAt(tab, i, null, fwd);
2449	>	else if ((fh = f.hash) == MOVED)
2450	>	advance = true; // already processed
2451	>	else {
2452	>	synchronized (f) {
2453	>	if (tabAt(tab, i) == f) {
2454	>	Node<K,V> ln, hn;
2455	>	if (fh >= 0) {
2456	>	int runBit = fh & n;
2457	>	Node<K,V> lastRun = f;
2458	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2459	>	int b = p.hash & n;
2460	>	if (b != runBit) {
2461	>	runBit = b;
2462	>	lastRun = p;
2463	>	}
2464	>	}
2465	>	if (runBit == 0) {
2466	>	ln = lastRun;
2467	>	hn = null;
2468	>	}
2469	>	else {
2470	>	hn = lastRun;
2471	>	ln = null;
2472	>	}
2473	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2474	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2475	>	if ((ph & n) == 0)
2476	>	ln = new Node<K,V>(ph, pk, pv, ln);
2477	>	else
2478	>	hn = new Node<K,V>(ph, pk, pv, hn);
2479	>	}
2480	>	setTabAt(nextTab, i, ln);
2481	>	setTabAt(nextTab, i + n, hn);
2482	>	setTabAt(tab, i, fwd);
2483	>	advance = true;
2484	>	}
2485	>	else if (f instanceof TreeBin) {
2486	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2487	>	TreeNode<K,V> lo = null, loTail = null;
2488	>	TreeNode<K,V> hi = null, hiTail = null;
2489	>	int lc = 0, hc = 0;
2490	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2491	>	int h = e.hash;
2492	>	TreeNode<K,V> p = new TreeNode<K,V>
2493	>	(h, e.key, e.val, null, null);
2494	>	if ((h & n) == 0) {
2495	>	if ((p.prev = loTail) == null)
2496	>	lo = p;
2497	>	else
2498	>	loTail.next = p;
2499	>	loTail = p;
2500	>	++lc;
2501	>	}
2502	>	else {
2503	>	if ((p.prev = hiTail) == null)
2504	>	hi = p;
2505	>	else
2506	>	hiTail.next = p;
2507	>	hiTail = p;
2508	>	++hc;
2509	>	}
2510	>	}
2511	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2512	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2513	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2514	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2515	>	setTabAt(nextTab, i, ln);
2516	>	setTabAt(nextTab, i + n, hn);
2517	>	setTabAt(tab, i, fwd);
2518	>	advance = true;
2519	>	}
2520	>	}
2521	>	}
2522	>	}
2523	>	}
2524	>	}
2525	>
2526	>	/* ---------------- Counter support -------------- */
2527	>
2528	>	/**
2529	>	* A padded cell for distributing counts.  Adapted from LongAdder
2530	>	* and Striped64.  See their internal docs for explanation.
2531	>	*/
2532	>	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2533	>	volatile long value;
2534	>	CounterCell(long x) { value = x; }
2535	>	}
2536	>
2537	>	final long sumCount() {
2538	>	CounterCell[] as = counterCells; CounterCell a;
2539	>	long sum = baseCount;
2540	>	if (as != null) {
2541	>	for (int i = 0; i < as.length; ++i) {
2542	>	if ((a = as[i]) != null)
2543	>	sum += a.value;
2544	>	}
2545	>	}
2546	>	return sum;
2547	>	}
2548	>
2549	>	// See LongAdder version for explanation
2550	>	private final void fullAddCount(long x, boolean wasUncontended) {
2551	>	int h;
2552	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2553	>	ThreadLocalRandom.localInit();      // force initialization
2554	>	h = ThreadLocalRandom.getProbe();
2555	>	wasUncontended = true;
2556	>	}
2557	>	boolean collide = false;                // True if last slot nonempty
2558	>	for (;;) {
2559	>	CounterCell[] as; CounterCell a; int n; long v;
2560	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2561	>	if ((a = as[(n - 1) & h]) == null) {
2562	>	if (cellsBusy == 0) {            // Try to attach new Cell
2563	>	CounterCell r = new CounterCell(x); // Optimistic create
2564	>	if (cellsBusy == 0 &&
2565	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2566	>	boolean created = false;
2567	>	try {               // Recheck under lock
2568	>	CounterCell[] rs; int m, j;
2569	>	if ((rs = counterCells) != null &&
2570	>	(m = rs.length) > 0 &&
2571	>	rs[j = (m - 1) & h] == null) {
2572	>	rs[j] = r;
2573	>	created = true;
2574	>	}
2575	>	} finally {
2576	>	cellsBusy = 0;
2577	>	}
2578	>	if (created)
2579	>	break;
2580	>	continue;           // Slot is now non-empty
2581	>	}
2582	>	}
2583	>	collide = false;
2584	>	}
2585	>	else if (!wasUncontended)       // CAS already known to fail
2586	>	wasUncontended = true;      // Continue after rehash
2587	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2588	>	break;
2589	>	else if (counterCells != as || n >= NCPU)
2590	>	collide = false;            // At max size or stale
2591	>	else if (!collide)
2592	>	collide = true;
2593	>	else if (cellsBusy == 0 &&
2594	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2595	>	try {
2596	>	if (counterCells == as) {// Expand table unless stale
2597	>	CounterCell[] rs = new CounterCell[n << 1];
2598	>	for (int i = 0; i < n; ++i)
2599	>	rs[i] = as[i];
2600	>	counterCells = rs;
2601	>	}
2602	>	} finally {
2603	>	cellsBusy = 0;
2604	>	}
2605	>	collide = false;
2606	>	continue;                   // Retry with expanded table
2607	>	}
2608	>	h = ThreadLocalRandom.advanceProbe(h);
2609	>	}
2610	>	else if (cellsBusy == 0 && counterCells == as &&
2611	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2612	>	boolean init = false;
2613	>	try {                           // Initialize table
2614	>	if (counterCells == as) {
2615	>	CounterCell[] rs = new CounterCell[2];
2616	>	rs[h & 1] = new CounterCell(x);
2617	>	counterCells = rs;
2618	>	init = true;
2619	>	}
2620	>	} finally {
2621	>	cellsBusy = 0;
2622	>	}
2623	>	if (init)
2624	>	break;
2625	>	}
2626	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2627	>	break;                          // Fall back on using base
2628	>	}
2629	>	}
2630	>
2631	>	/* ---------------- Conversion from/to TreeBins -------------- */
2632	>
2633	>	/**
2634	>	* Replaces all linked nodes in bin at given index unless table is
2635	>	* too small, in which case resizes instead.
2636	>	*/
2637	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2638	>	Node<K,V> b; int n;
2639	>	if (tab != null) {
2640	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2641	>	tryPresize(n << 1);
2642	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2643	>	synchronized (b) {
2644	>	if (tabAt(tab, index) == b) {
2645	>	TreeNode<K,V> hd = null, tl = null;
2646	>	for (Node<K,V> e = b; e != null; e = e.next) {
2647	>	TreeNode<K,V> p =
2648	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2649	>	null, null);
2650	>	if ((p.prev = tl) == null)
2651	>	hd = p;
2652	>	else
2653	>	tl.next = p;
2654	>	tl = p;
2655	>	}
2656	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2657	>	}
2658	>	}
2659	>	}
2660	>	}
2661	>	}
2662	>
2663	>	/**
2664	>	* Returns a list of non-TreeNodes replacing those in given list.
2665	>	*/
2666	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2667	>	Node<K,V> hd = null, tl = null;
2668	>	for (Node<K,V> q = b; q != null; q = q.next) {
2669	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2670	>	if (tl == null)
2671	>	hd = p;
2672	>	else
2673	>	tl.next = p;
2674	>	tl = p;
2675	>	}
2676	>	return hd;
2677	>	}
2678	>
2679	>	/* ---------------- TreeNodes -------------- */
2680	>
2681	>	/**
2682	>	* Nodes for use in TreeBins.
2683	>	*/
2684	>	static final class TreeNode<K,V> extends Node<K,V> {
2685	>	TreeNode<K,V> parent;  // red-black tree links
2686	>	TreeNode<K,V> left;
2687	>	TreeNode<K,V> right;
2688	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2689	>	boolean red;
2690	>
2691	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2692	>	TreeNode<K,V> parent) {
2693	>	super(hash, key, val, next);
2694	>	this.parent = parent;
2695	>	}
2696	>
2697	>	Node<K,V> find(int h, Object k) {
2698	>	return findTreeNode(h, k, null);
2699	>	}
2700
2701		/**
2702	<	* The table is rehashed when its size exceeds this threshold.
2703	<	* (The value of this field is always (int)(capacity *
196	<	* loadFactor).)
2702	>	* Returns the TreeNode (or null if not found) for the given key
2703	>	* starting at given root.
2704		*/
2705	<	private transient int threshold;
2705	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2706	>	if (k != null) {
2707	>	TreeNode<K,V> p = this;
2708	>	do {
2709	>	int ph, dir; K pk; TreeNode<K,V> q;
2710	>	TreeNode<K,V> pl = p.left, pr = p.right;
2711	>	if ((ph = p.hash) > h)
2712	>	p = pl;
2713	>	else if (ph < h)
2714	>	p = pr;
2715	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2716	>	return p;
2717	>	else if (pl == null)
2718	>	p = pr;
2719	>	else if (pr == null)
2720	>	p = pl;
2721	>	else if ((kc != null ||
2722	>	(kc = comparableClassFor(k)) != null) &&
2723	>	(dir = compareComparables(kc, k, pk)) != 0)
2724	>	p = (dir < 0) ? pl : pr;
2725	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2726	>	return q;
2727	>	else
2728	>	p = pl;
2729	>	} while (p != null);
2730	>	}
2731	>	return null;
2732	>	}
2733	>	}
2734	>
2735	>	/* ---------------- TreeBins -------------- */
2736	>
2737	>	/**
2738	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2739	>	* keys or values, but instead point to list of TreeNodes and
2740	>	* their root. They also maintain a parasitic read-write lock
2741	>	* forcing writers (who hold bin lock) to wait for readers (who do
2742	>	* not) to complete before tree restructuring operations.
2743	>	*/
2744	>	static final class TreeBin<K,V> extends Node<K,V> {
2745	>	TreeNode<K,V> root;
2746	>	volatile TreeNode<K,V> first;
2747	>	volatile Thread waiter;
2748	>	volatile int lockState;
2749	>	// values for lockState
2750	>	static final int WRITER = 1; // set while holding write lock
2751	>	static final int WAITER = 2; // set when waiting for write lock
2752	>	static final int READER = 4; // increment value for setting read lock
2753
2754		/**
2755	<	* The per-segment table
2755	>	* Tie-breaking utility for ordering insertions when equal
2756	>	* hashCodes and non-comparable. We don't require a total
2757	>	* order, just a consistent insertion rule to maintain
2758	>	* equivalence across rebalancings. Tie-breaking further than
2759	>	* necessary simplifies testing a bit.
2760		*/
2761	<	transient HashEntry[] table;
2761	>	static int tieBreakOrder(Object a, Object b) {
2762	>	int d;
2763	>	if (a == null || b == null ||
2764	>	(d = a.getClass().getName().
2765	>	compareTo(b.getClass().getName())) == 0)
2766	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2767	>	-1 : 1);
2768	>	return d;
2769	>	}
2770
2771		/**
2772	<	* The load factor for the hash table.  Even though this value
207	<	* is same for all segments, it is replicated to avoid needing
208	<	* links to outer object.
209	<	* @serial
2772	>	* Creates bin with initial set of nodes headed by b.
2773		*/
2774	<	private final float loadFactor;
2775	<
2776	<	Segment(int initialCapacity, float lf) {
2777	<	loadFactor = lf;
2778	<	setTable(new HashEntry[initialCapacity]);
2774	>	TreeBin(TreeNode<K,V> b) {
2775	>	super(TREEBIN, null, null);
2776	>	this.first = b;
2777	>	TreeNode<K,V> r = null;
2778	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2779	>	next = (TreeNode<K,V>)x.next;
2780	>	x.left = x.right = null;
2781	>	if (r == null) {
2782	>	x.parent = null;
2783	>	x.red = false;
2784	>	r = x;
2785	>	}
2786	>	else {
2787	>	K k = x.key;
2788	>	int h = x.hash;
2789	>	Class<?> kc = null;
2790	>	for (TreeNode<K,V> p = r;;) {
2791	>	int dir, ph;
2792	>	K pk = p.key;
2793	>	if ((ph = p.hash) > h)
2794	>	dir = -1;
2795	>	else if (ph < h)
2796	>	dir = 1;
2797	>	else if ((kc == null &&
2798	>	(kc = comparableClassFor(k)) == null) ||
2799	>	(dir = compareComparables(kc, k, pk)) == 0)
2800	>	dir = tieBreakOrder(k, pk);
2801	>	TreeNode<K,V> xp = p;
2802	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2803	>	x.parent = xp;
2804	>	if (dir <= 0)
2805	>	xp.left = x;
2806	>	else
2807	>	xp.right = x;
2808	>	r = balanceInsertion(r, x);
2809	>	break;
2810	>	}
2811	>	}
2812	>	}
2813	>	}
2814	>	this.root = r;
2815	>	assert checkInvariants(root);
2816		}
2817
2818		/**
2819	<	* Set table to new HashEntry array.
2820	<	* Call only while holding lock or in constructor.
2821	<	**/
2822	<	private void setTable(HashEntry[] newTable) {
2823	<	table = newTable;
224	<	threshold = (int)(newTable.length * loadFactor);
225	<	count = count; // write-volatile
2819	>	* Acquires write lock for tree restructuring.
2820	>	*/
2821	>	private final void lockRoot() {
2822	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2823	>	contendedLock(); // offload to separate method
2824		}
2825
2826	<	/* Specialized implementations of map methods */
2826	>	/**
2827	>	* Releases write lock for tree restructuring.
2828	>	*/
2829	>	private final void unlockRoot() {
2830	>	lockState = 0;
2831	>	}
2832
2833	<	V get(K key, int hash) {
2834	<	if (count != 0) { // read-volatile
2835	<	HashEntry[] tab = table;
2836	<	int index = hash & (tab.length - 1);
2837	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
2838	<	while (e != null) {
2839	<	if (e.hash == hash && key.equals(e.key))
2840	<	return e.value;
2841	<	e = e.next;
2833	>	/**
2834	>	* Possibly blocks awaiting root lock.
2835	>	*/
2836	>	private final void contendedLock() {
2837	>	boolean waiting = false;
2838	>	for (int s;;) {
2839	>	if (((s = lockState) & ~WAITER) == 0) {
2840	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2841	>	if (waiting)
2842	>	waiter = null;
2843	>	return;
2844	>	}
2845	>	}
2846	>	else if ((s & WAITER) == 0) {
2847	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2848	>	waiting = true;
2849	>	waiter = Thread.currentThread();
2850	>	}
2851		}
2852	+	else if (waiting)
2853	+	LockSupport.park(this);
2854		}
241	–	return null;
2855		}
2856
2857	<	boolean containsKey(Object key, int hash) {
2858	<	if (count != 0) { // read-volatile
2859	<	HashEntry[] tab = table;
2860	<	int index = hash & (tab.length - 1);
2861	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
2862	<	while (e != null) {
2863	<	if (e.hash == hash && key.equals(e.key))
2864	<	return true;
2865	<	e = e.next;
2857	>	/**
2858	>	* Returns matching node or null if none. Tries to search
2859	>	* using tree comparisons from root, but continues linear
2860	>	* search when lock not available.
2861	>	*/
2862	>	final Node<K,V> find(int h, Object k) {
2863	>	if (k != null) {
2864	>	for (Node<K,V> e = first; e != null; ) {
2865	>	int s; K ek;
2866	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2867	>	if (e.hash == h &&
2868	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2869	>	return e;
2870	>	e = e.next;
2871	>	}
2872	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2873	>	s + READER)) {
2874	>	TreeNode<K,V> r, p;
2875	>	try {
2876	>	p = ((r = root) == null ? null :
2877	>	r.findTreeNode(h, k, null));
2878	>	} finally {
2879	>	Thread w;
2880	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2881	>	(READER|WAITER) && (w = waiter) != null)
2882	>	LockSupport.unpark(w);
2883	>	}
2884	>	return p;
2885	>	}
2886		}
2887		}
2888	<	return false;
2888	>	return null;
2889		}
2890
2891	<	boolean containsValue(Object value) {
2892	<	if (count != 0) { // read-volatile
2893	<	HashEntry[] tab = table;
2894	<	int len = tab.length;
2895	<	for (int i = 0 ; i < len; i++)
2896	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
2897	<	if (value.equals(e.value))
2898	<	return true;
2891	>	/**
2892	>	* Finds or adds a node.
2893	>	* @return null if added
2894	>	*/
2895	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2896	>	Class<?> kc = null;
2897	>	boolean searched = false;
2898	>	for (TreeNode<K,V> p = root;;) {
2899	>	int dir, ph; K pk;
2900	>	if (p == null) {
2901	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2902	>	break;
2903	>	}
2904	>	else if ((ph = p.hash) > h)
2905	>	dir = -1;
2906	>	else if (ph < h)
2907	>	dir = 1;
2908	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2909	>	return p;
2910	>	else if ((kc == null &&
2911	>	(kc = comparableClassFor(k)) == null) ||
2912	>	(dir = compareComparables(kc, k, pk)) == 0) {
2913	>	if (!searched) {
2914	>	TreeNode<K,V> q, ch;
2915	>	searched = true;
2916	>	if (((ch = p.left) != null &&
2917	>	(q = ch.findTreeNode(h, k, kc)) != null) ||
2918	>	((ch = p.right) != null &&
2919	>	(q = ch.findTreeNode(h, k, kc)) != null))
2920	>	return q;
2921	>	}
2922	>	dir = tieBreakOrder(k, pk);
2923	>	}
2924	>
2925	>	TreeNode<K,V> xp = p;
2926	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2927	>	TreeNode<K,V> x, f = first;
2928	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2929	>	if (f != null)
2930	>	f.prev = x;
2931	>	if (dir <= 0)
2932	>	xp.left = x;
2933	>	else
2934	>	xp.right = x;
2935	>	if (!xp.red)
2936	>	x.red = true;
2937	>	else {
2938	>	lockRoot();
2939	>	try {
2940	>	root = balanceInsertion(root, x);
2941	>	} finally {
2942	>	unlockRoot();
2943	>	}
2944	>	}
2945	>	break;
2946	>	}
2947		}
2948	<	return false;
2948	>	assert checkInvariants(root);
2949	>	return null;
2950		}
2951
2952	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
2953	<	lock();
2952	>	/**
2953	>	* Removes the given node, that must be present before this
2954	>	* call.  This is messier than typical red-black deletion code
2955	>	* because we cannot swap the contents of an interior node
2956	>	* with a leaf successor that is pinned by "next" pointers
2957	>	* that are accessible independently of lock. So instead we
2958	>	* swap the tree linkages.
2959	>	*
2960	>	* @return true if now too small, so should be untreeified
2961	>	*/
2962	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2963	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2964	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2965	>	TreeNode<K,V> r, rl;
2966	>	if (pred == null)
2967	>	first = next;
2968	>	else
2969	>	pred.next = next;
2970	>	if (next != null)
2971	>	next.prev = pred;
2972	>	if (first == null) {
2973	>	root = null;
2974	>	return true;
2975	>	}
2976	>	if ((r = root) == null || r.right == null || // too small
2977	>	(rl = r.left) == null || rl.left == null)
2978	>	return true;
2979	>	lockRoot();
2980		try {
2981	<	int c = count;
2982	<	HashEntry[] tab = table;
2983	<	int index = hash & (tab.length - 1);
2984	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
2985	<
2986	<	for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
2987	<	if (e.hash == hash && key.equals(e.key)) {
2988	<	V oldValue = e.value;
2989	<	if (!onlyIfAbsent)
2990	<	e.value = value;
2991	<	count = c; // write-volatile
2992	<	return oldValue;
2981	>	TreeNode<K,V> replacement;
2982	>	TreeNode<K,V> pl = p.left;
2983	>	TreeNode<K,V> pr = p.right;
2984	>	if (pl != null && pr != null) {
2985	>	TreeNode<K,V> s = pr, sl;
2986	>	while ((sl = s.left) != null) // find successor
2987	>	s = sl;
2988	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2989	>	TreeNode<K,V> sr = s.right;
2990	>	TreeNode<K,V> pp = p.parent;
2991	>	if (s == pr) { // p was s's direct parent
2992	>	p.parent = s;
2993	>	s.right = p;
2994	>	}
2995	>	else {
2996	>	TreeNode<K,V> sp = s.parent;
2997	>	if ((p.parent = sp) != null) {
2998	>	if (s == sp.left)
2999	>	sp.left = p;
3000	>	else
3001	>	sp.right = p;
3002	>	}
3003	>	if ((s.right = pr) != null)
3004	>	pr.parent = s;
3005		}
3006	+	p.left = null;
3007	+	if ((p.right = sr) != null)
3008	+	sr.parent = p;
3009	+	if ((s.left = pl) != null)
3010	+	pl.parent = s;
3011	+	if ((s.parent = pp) == null)
3012	+	r = s;
3013	+	else if (p == pp.left)
3014	+	pp.left = s;
3015	+	else
3016	+	pp.right = s;
3017	+	if (sr != null)
3018	+	replacement = sr;
3019	+	else
3020	+	replacement = p;
3021	+	}
3022	+	else if (pl != null)
3023	+	replacement = pl;
3024	+	else if (pr != null)
3025	+	replacement = pr;
3026	+	else
3027	+	replacement = p;
3028	+	if (replacement != p) {
3029	+	TreeNode<K,V> pp = replacement.parent = p.parent;
3030	+	if (pp == null)
3031	+	r = replacement;
3032	+	else if (p == pp.left)
3033	+	pp.left = replacement;
3034	+	else
3035	+	pp.right = replacement;
3036	+	p.left = p.right = p.parent = null;
3037		}
3038
3039	<	tab[index] = new HashEntry<K,V>(hash, key, value, first);
3040	<	++c;
3041	<	count = c; // write-volatile
3042	<	if (c > threshold)
3043	<	setTable(rehash(tab));
3044	<	return null;
3045	<	}
3046	<	finally {
3047	<	unlock();
3039	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3040	>
3041	>	if (p == replacement) {  // detach pointers
3042	>	TreeNode<K,V> pp;
3043	>	if ((pp = p.parent) != null) {
3044	>	if (p == pp.left)
3045	>	pp.left = null;
3046	>	else if (p == pp.right)
3047	>	pp.right = null;
3048	>	p.parent = null;
3049	>	}
3050	>	}
3051	>	} finally {
3052	>	unlockRoot();
3053	>	}
3054	>	assert checkInvariants(root);
3055	>	return false;
3056	>	}
3057	>
3058	>	/* ------------------------------------------------------------ */
3059	>	// Red-black tree methods, all adapted from CLR
3060	>
3061	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3062	>	TreeNode<K,V> p) {
3063	>	TreeNode<K,V> r, pp, rl;
3064	>	if (p != null && (r = p.right) != null) {
3065	>	if ((rl = p.right = r.left) != null)
3066	>	rl.parent = p;
3067	>	if ((pp = r.parent = p.parent) == null)
3068	>	(root = r).red = false;
3069	>	else if (pp.left == p)
3070	>	pp.left = r;
3071	>	else
3072	>	pp.right = r;
3073	>	r.left = p;
3074	>	p.parent = r;
3075		}
3076	+	return root;
3077		}
3078
3079	<	private HashEntry[] rehash(HashEntry[] oldTable) {
3080	<	int oldCapacity = oldTable.length;
3081	<	if (oldCapacity >= MAXIMUM_CAPACITY)
3082	<	return oldTable;
3083	<
3084	<	/*
3085	<	* Reclassify nodes in each list to new Map.  Because we are
3086	<	* using power-of-two expansion, the elements from each bin
3087	<	* must either stay at same index, or move with a power of two
3088	<	* offset. We eliminate unnecessary node creation by catching
3089	<	* cases where old nodes can be reused because their next
3090	<	* fields won't change. Statistically, at the default
3091	<	* threshhold, only about one-sixth of them need cloning when
3092	<	* a table doubles. The nodes they replace will be garbage
3093	<	* collectable as soon as they are no longer referenced by any
3094	<	* reader thread that may be in the midst of traversing table
3095	<	* right now.
317	<	*/
318	<
319	<	HashEntry[] newTable = new HashEntry[oldCapacity << 1];
320	<	int sizeMask = newTable.length - 1;
321	<	for (int i = 0; i < oldCapacity ; i++) {
322	<	// We need to guarantee that any existing reads of old Map can
323	<	//  proceed. So we cannot yet null out each bin.
324	<	HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
325	<
326	<	if (e != null) {
327	<	HashEntry<K,V> next = e.next;
328	<	int idx = e.hash & sizeMask;
329	<
330	<	//  Single node on list
331	<	if (next == null)
332	<	newTable[idx] = e;
3079	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3080	>	TreeNode<K,V> p) {
3081	>	TreeNode<K,V> l, pp, lr;
3082	>	if (p != null && (l = p.left) != null) {
3083	>	if ((lr = p.left = l.right) != null)
3084	>	lr.parent = p;
3085	>	if ((pp = l.parent = p.parent) == null)
3086	>	(root = l).red = false;
3087	>	else if (pp.right == p)
3088	>	pp.right = l;
3089	>	else
3090	>	pp.left = l;
3091	>	l.right = p;
3092	>	p.parent = l;
3093	>	}
3094	>	return root;
3095	>	}
3096
3097	+	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3098	+	TreeNode<K,V> x) {
3099	+	x.red = true;
3100	+	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3101	+	if ((xp = x.parent) == null) {
3102	+	x.red = false;
3103	+	return x;
3104	+	}
3105	+	else if (!xp.red || (xpp = xp.parent) == null)
3106	+	return root;
3107	+	if (xp == (xppl = xpp.left)) {
3108	+	if ((xppr = xpp.right) != null && xppr.red) {
3109	+	xppr.red = false;
3110	+	xp.red = false;
3111	+	xpp.red = true;
3112	+	x = xpp;
3113	+	}
3114	+	else {
3115	+	if (x == xp.right) {
3116	+	root = rotateLeft(root, x = xp);
3117	+	xpp = (xp = x.parent) == null ? null : xp.parent;
3118	+	}
3119	+	if (xp != null) {
3120	+	xp.red = false;
3121	+	if (xpp != null) {
3122	+	xpp.red = true;
3123	+	root = rotateRight(root, xpp);
3124	+	}
3125	+	}
3126	+	}
3127	+	}
3128	+	else {
3129	+	if (xppl != null && xppl.red) {
3130	+	xppl.red = false;
3131	+	xp.red = false;
3132	+	xpp.red = true;
3133	+	x = xpp;
3134	+	}
3135		else {
3136	<	// Reuse trailing consecutive sequence at same slot
3137	<	HashEntry<K,V> lastRun = e;
3138	<	int lastIdx = idx;
3139	<	for (HashEntry<K,V> last = next;
3140	<	last != null;
3141	<	last = last.next) {
3142	<	int k = last.hash & sizeMask;
3143	<	if (k != lastIdx) {
3144	<	lastIdx = k;
344	<	lastRun = last;
3136	>	if (x == xp.left) {
3137	>	root = rotateRight(root, x = xp);
3138	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3139	>	}
3140	>	if (xp != null) {
3141	>	xp.red = false;
3142	>	if (xpp != null) {
3143	>	xpp.red = true;
3144	>	root = rotateLeft(root, xpp);
3145		}
3146		}
3147	<	newTable[lastIdx] = lastRun;
3147	>	}
3148	>	}
3149	>	}
3150	>	}
3151
3152	<	// Clone all remaining nodes
3153	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
3154	<	int k = p.hash & sizeMask;
3155	<	newTable[k] = new HashEntry<K,V>(p.hash,
3156	<	p.key,
3157	<	p.value,
3158	<	(HashEntry<K,V>) newTable[k]);
3152	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3153	>	TreeNode<K,V> x) {
3154	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3155	>	if (x == null || x == root)
3156	>	return root;
3157	>	else if ((xp = x.parent) == null) {
3158	>	x.red = false;
3159	>	return x;
3160	>	}
3161	>	else if (x.red) {
3162	>	x.red = false;
3163	>	return root;
3164	>	}
3165	>	else if ((xpl = xp.left) == x) {
3166	>	if ((xpr = xp.right) != null && xpr.red) {
3167	>	xpr.red = false;
3168	>	xp.red = true;
3169	>	root = rotateLeft(root, xp);
3170	>	xpr = (xp = x.parent) == null ? null : xp.right;
3171	>	}
3172	>	if (xpr == null)
3173	>	x = xp;
3174	>	else {
3175	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3176	>	if ((sr == null || !sr.red) &&
3177	>	(sl == null || !sl.red)) {
3178	>	xpr.red = true;
3179	>	x = xp;
3180	>	}
3181	>	else {
3182	>	if (sr == null || !sr.red) {
3183	>	if (sl != null)
3184	>	sl.red = false;
3185	>	xpr.red = true;
3186	>	root = rotateRight(root, xpr);
3187	>	xpr = (xp = x.parent) == null ?
3188	>	null : xp.right;
3189	>	}
3190	>	if (xpr != null) {
3191	>	xpr.red = (xp == null) ? false : xp.red;
3192	>	if ((sr = xpr.right) != null)
3193	>	sr.red = false;
3194	>	}
3195	>	if (xp != null) {
3196	>	xp.red = false;
3197	>	root = rotateLeft(root, xp);
3198	>	}
3199	>	x = root;
3200	>	}
3201	>	}
3202	>	}
3203	>	else { // symmetric
3204	>	if (xpl != null && xpl.red) {
3205	>	xpl.red = false;
3206	>	xp.red = true;
3207	>	root = rotateRight(root, xp);
3208	>	xpl = (xp = x.parent) == null ? null : xp.left;
3209	>	}
3210	>	if (xpl == null)
3211	>	x = xp;
3212	>	else {
3213	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3214	>	if ((sl == null || !sl.red) &&
3215	>	(sr == null || !sr.red)) {
3216	>	xpl.red = true;
3217	>	x = xp;
3218	>	}
3219	>	else {
3220	>	if (sl == null || !sl.red) {
3221	>	if (sr != null)
3222	>	sr.red = false;
3223	>	xpl.red = true;
3224	>	root = rotateLeft(root, xpl);
3225	>	xpl = (xp = x.parent) == null ?
3226	>	null : xp.left;
3227	>	}
3228	>	if (xpl != null) {
3229	>	xpl.red = (xp == null) ? false : xp.red;
3230	>	if ((sl = xpl.left) != null)
3231	>	sl.red = false;
3232	>	}
3233	>	if (xp != null) {
3234	>	xp.red = false;
3235	>	root = rotateRight(root, xp);
3236	>	}
3237	>	x = root;
3238		}
3239		}
3240		}
3241		}
360	–	return newTable;
3242		}
3243
3244		/**
3245	<	* Remove; match on key only if value null, else match both.
3245	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3246		*/
3247	<	V remove(Object key, int hash, Object value) {
3248	<	lock();
3247	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3248	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3249	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3250	>	if (tb != null && tb.next != t)
3251	>	return false;
3252	>	if (tn != null && tn.prev != t)
3253	>	return false;
3254	>	if (tp != null && t != tp.left && t != tp.right)
3255	>	return false;
3256	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3257	>	return false;
3258	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3259	>	return false;
3260	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3261	>	return false;
3262	>	if (tl != null && !checkInvariants(tl))
3263	>	return false;
3264	>	if (tr != null && !checkInvariants(tr))
3265	>	return false;
3266	>	return true;
3267	>	}
3268	>
3269	>	private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
3270	>	private static final long LOCKSTATE;
3271	>	static {
3272		try {
3273	<	int c = count;
3274	<	HashEntry[] tab = table;
3275	<	int index = hash & (tab.length - 1);
3276	<	HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
3273	>	LOCKSTATE = U.objectFieldOffset
3274	>	(TreeBin.class.getDeclaredField("lockState"));
3275	>	} catch (ReflectiveOperationException e) {
3276	>	throw new Error(e);
3277	>	}
3278	>	}
3279	>	}
3280
3281	<	HashEntry<K,V> e = first;
375	<	for (;;) {
376	<	if (e == null)
377	<	return null;
378	<	if (e.hash == hash && key.equals(e.key))
379	<	break;
380	<	e = e.next;
381	<	}
3281	>	/* ----------------Table Traversal -------------- */
3282
3283	<	V oldValue = e.value;
3284	<	if (value != null && !value.equals(oldValue))
3285	<	return null;
3283	>	/**
3284	>	* Records the table, its length, and current traversal index for a
3285	>	* traverser that must process a region of a forwarded table before
3286	>	* proceeding with current table.
3287	>	*/
3288	>	static final class TableStack<K,V> {
3289	>	int length;
3290	>	int index;
3291	>	Node<K,V>[] tab;
3292	>	TableStack<K,V> next;
3293	>	}
3294
3295	<	// All entries following removed node can stay in list, but
3296	<	// all preceeding ones need to be cloned.
3297	<	HashEntry<K,V> newFirst = e.next;
3298	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
3299	<	newFirst = new HashEntry<K,V>(p.hash, p.key,
3300	<	p.value, newFirst);
3301	<	tab[index] = newFirst;
3302	<	count = c-1; // write-volatile
3303	<	return oldValue;
3304	<	}
3305	<	finally {
3306	<	unlock();
3307	<	}
3295	>	/**
3296	>	* Encapsulates traversal for methods such as containsValue; also
3297	>	* serves as a base class for other iterators and spliterators.
3298	>	*
3299	>	* Method advance visits once each still-valid node that was
3300	>	* reachable upon iterator construction. It might miss some that
3301	>	* were added to a bin after the bin was visited, which is OK wrt
3302	>	* consistency guarantees. Maintaining this property in the face
3303	>	* of possible ongoing resizes requires a fair amount of
3304	>	* bookkeeping state that is difficult to optimize away amidst
3305	>	* volatile accesses.  Even so, traversal maintains reasonable
3306	>	* throughput.
3307	>	*
3308	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3309	>	* However, if the table has been resized, then all future steps
3310	>	* must traverse both the bin at the current index as well as at
3311	>	* (index + baseSize); and so on for further resizings. To
3312	>	* paranoically cope with potential sharing by users of iterators
3313	>	* across threads, iteration terminates if a bounds checks fails
3314	>	* for a table read.
3315	>	*/
3316	>	static class Traverser<K,V> {
3317	>	Node<K,V>[] tab;        // current table; updated if resized
3318	>	Node<K,V> next;         // the next entry to use
3319	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3320	>	int index;              // index of bin to use next
3321	>	int baseIndex;          // current index of initial table
3322	>	int baseLimit;          // index bound for initial table
3323	>	final int baseSize;     // initial table size
3324	>
3325	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3326	>	this.tab = tab;
3327	>	this.baseSize = size;
3328	>	this.baseIndex = this.index = index;
3329	>	this.baseLimit = limit;
3330	>	this.next = null;
3331		}
3332
3333	<	void clear() {
3334	<	lock();
3335	<	try {
3336	<	HashEntry[] tab = table;
3337	<	for (int i = 0; i < tab.length ; i++)
3338	<	tab[i] = null;
3339	<	count = 0; // write-volatile
3333	>	/**
3334	>	* Advances if possible, returning next valid node, or null if none.
3335	>	*/
3336	>	final Node<K,V> advance() {
3337	>	Node<K,V> e;
3338	>	if ((e = next) != null)
3339	>	e = e.next;
3340	>	for (;;) {
3341	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3342	>	if (e != null)
3343	>	return next = e;
3344	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3345	>	(n = t.length) <= (i = index) || i < 0)
3346	>	return next = null;
3347	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3348	>	if (e instanceof ForwardingNode) {
3349	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3350	>	e = null;
3351	>	pushState(t, i, n);
3352	>	continue;
3353	>	}
3354	>	else if (e instanceof TreeBin)
3355	>	e = ((TreeBin<K,V>)e).first;
3356	>	else
3357	>	e = null;
3358	>	}
3359	>	if (stack != null)
3360	>	recoverState(n);
3361	>	else if ((index = i + baseSize) >= n)
3362	>	index = ++baseIndex; // visit upper slots if present
3363		}
3364	<	finally {
3365	<	unlock();
3364	>	}
3365	>
3366	>	/**
3367	>	* Saves traversal state upon encountering a forwarding node.
3368	>	*/
3369	>	private void pushState(Node<K,V>[] t, int i, int n) {
3370	>	TableStack<K,V> s = spare;  // reuse if possible
3371	>	if (s != null)
3372	>	spare = s.next;
3373	>	else
3374	>	s = new TableStack<K,V>();
3375	>	s.tab = t;
3376	>	s.length = n;
3377	>	s.index = i;
3378	>	s.next = stack;
3379	>	stack = s;
3380	>	}
3381	>
3382	>	/**
3383	>	* Possibly pops traversal state.
3384	>	*
3385	>	* @param n length of current table
3386	>	*/
3387	>	private void recoverState(int n) {
3388	>	TableStack<K,V> s; int len;
3389	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3390	>	n = len;
3391	>	index = s.index;
3392	>	tab = s.tab;
3393	>	s.tab = null;
3394	>	TableStack<K,V> next = s.next;
3395	>	s.next = spare; // save for reuse
3396	>	stack = next;
3397	>	spare = s;
3398		}
3399	+	if (s == null && (index += baseSize) >= n)
3400	+	index = ++baseIndex;
3401		}
3402		}
3403
3404		/**
3405	<	* ConcurrentReaderHashMap list entry.
3405	>	* Base of key, value, and entry Iterators. Adds fields to
3406	>	* Traverser to support iterator.remove.
3407		*/
3408	<	private static class HashEntry<K,V> implements Entry<K,V> {
3409	<	private final K key;
3410	<	private V value;
3411	<	private final int hash;
3412	<	private final HashEntry<K,V> next;
3408	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3409	>	final ConcurrentHashMap<K,V> map;
3410	>	Node<K,V> lastReturned;
3411	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3412	>	ConcurrentHashMap<K,V> map) {
3413	>	super(tab, size, index, limit);
3414	>	this.map = map;
3415	>	advance();
3416	>	}
3417
3418	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
3419	<	this.value = value;
3420	<	this.hash = hash;
3421	<	this.key = key;
3422	<	this.next = next;
3418	>	public final boolean hasNext() { return next != null; }
3419	>	public final boolean hasMoreElements() { return next != null; }
3420	>
3421	>	public final void remove() {
3422	>	Node<K,V> p;
3423	>	if ((p = lastReturned) == null)
3424	>	throw new IllegalStateException();
3425	>	lastReturned = null;
3426	>	map.replaceNode(p.key, null, null);
3427	>	}
3428	>	}
3429	>
3430	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3431	>	implements Iterator<K>, Enumeration<K> {
3432	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3433	>	ConcurrentHashMap<K,V> map) {
3434	>	super(tab, index, size, limit, map);
3435	>	}
3436	>
3437	>	public final K next() {
3438	>	Node<K,V> p;
3439	>	if ((p = next) == null)
3440	>	throw new NoSuchElementException();
3441	>	K k = p.key;
3442	>	lastReturned = p;
3443	>	advance();
3444	>	return k;
3445	>	}
3446	>
3447	>	public final K nextElement() { return next(); }
3448	>	}
3449	>
3450	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3451	>	implements Iterator<V>, Enumeration<V> {
3452	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3453	>	ConcurrentHashMap<K,V> map) {
3454	>	super(tab, index, size, limit, map);
3455	>	}
3456	>
3457	>	public final V next() {
3458	>	Node<K,V> p;
3459	>	if ((p = next) == null)
3460	>	throw new NoSuchElementException();
3461	>	V v = p.val;
3462	>	lastReturned = p;
3463	>	advance();
3464	>	return v;
3465		}
3466
3467	<	public K getKey() {
3468	<	return key;
3467	>	public final V nextElement() { return next(); }
3468	>	}
3469	>
3470	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3471	>	implements Iterator<Map.Entry<K,V>> {
3472	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3473	>	ConcurrentHashMap<K,V> map) {
3474	>	super(tab, index, size, limit, map);
3475		}
3476
3477	<	public V getValue() {
3478	<	return value;
3477	>	public final Map.Entry<K,V> next() {
3478	>	Node<K,V> p;
3479	>	if ((p = next) == null)
3480	>	throw new NoSuchElementException();
3481	>	K k = p.key;
3482	>	V v = p.val;
3483	>	lastReturned = p;
3484	>	advance();
3485	>	return new MapEntry<K,V>(k, v, map);
3486		}
3487	+	}
3488
3489	<	public V setValue(V newValue) {
3490	<	// We aren't required to, and don't provide any
3491	<	// visibility barriers for setting value.
3492	<	if (newValue == null)
3493	<	throw new NullPointerException();
3494	<	V oldValue = this.value;
3495	<	this.value = newValue;
3496	<	return oldValue;
3489	>	/**
3490	>	* Exported Entry for EntryIterator.
3491	>	*/
3492	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3493	>	final K key; // non-null
3494	>	V val;       // non-null
3495	>	final ConcurrentHashMap<K,V> map;
3496	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3497	>	this.key = key;
3498	>	this.val = val;
3499	>	this.map = map;
3500	>	}
3501	>	public K getKey()        { return key; }
3502	>	public V getValue()      { return val; }
3503	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3504	>	public String toString() {
3505	>	return Helpers.mapEntryToString(key, val);
3506		}
3507
3508		public boolean equals(Object o) {
3509	<	if (!(o instanceof Entry))
3509	>	Object k, v; Map.Entry<?,?> e;
3510	>	return ((o instanceof Map.Entry) &&
3511	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3512	>	(v = e.getValue()) != null &&
3513	>	(k == key || k.equals(key)) &&
3514	>	(v == val || v.equals(val)));
3515	>	}
3516	>
3517	>	/**
3518	>	* Sets our entry's value and writes through to the map. The
3519	>	* value to return is somewhat arbitrary here. Since we do not
3520	>	* necessarily track asynchronous changes, the most recent
3521	>	* "previous" value could be different from what we return (or
3522	>	* could even have been removed, in which case the put will
3523	>	* re-establish). We do not and cannot guarantee more.
3524	>	*/
3525	>	public V setValue(V value) {
3526	>	if (value == null) throw new NullPointerException();
3527	>	V v = val;
3528	>	val = value;
3529	>	map.put(key, value);
3530	>	return v;
3531	>	}
3532	>	}
3533	>
3534	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3535	>	implements Spliterator<K> {
3536	>	long est;               // size estimate
3537	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3538	>	long est) {
3539	>	super(tab, size, index, limit);
3540	>	this.est = est;
3541	>	}
3542	>
3543	>	public KeySpliterator<K,V> trySplit() {
3544	>	int i, f, h;
3545	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3546	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3547	>	f, est >>>= 1);
3548	>	}
3549	>
3550	>	public void forEachRemaining(Consumer<? super K> action) {
3551	>	if (action == null) throw new NullPointerException();
3552	>	for (Node<K,V> p; (p = advance()) != null;)
3553	>	action.accept(p.key);
3554	>	}
3555	>
3556	>	public boolean tryAdvance(Consumer<? super K> action) {
3557	>	if (action == null) throw new NullPointerException();
3558	>	Node<K,V> p;
3559	>	if ((p = advance()) == null)
3560		return false;
3561	<	Entry<K,V> e = (Entry<K,V>)o;
3562	<	return (key.equals(e.getKey()) && value.equals(e.getValue()));
3561	>	action.accept(p.key);
3562	>	return true;
3563		}
3564
3565	<	public int hashCode() {
3566	<	return  key.hashCode() ^ value.hashCode();
3565	>	public long estimateSize() { return est; }
3566	>
3567	>	public int characteristics() {
3568	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3569	>	Spliterator.NONNULL;
3570		}
3571	+	}
3572
3573	<	public String toString() {
3574	<	return key + "=" + value;
3573	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3574	>	implements Spliterator<V> {
3575	>	long est;               // size estimate
3576	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3577	>	long est) {
3578	>	super(tab, size, index, limit);
3579	>	this.est = est;
3580	>	}
3581	>
3582	>	public ValueSpliterator<K,V> trySplit() {
3583	>	int i, f, h;
3584	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3585	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3586	>	f, est >>>= 1);
3587	>	}
3588	>
3589	>	public void forEachRemaining(Consumer<? super V> action) {
3590	>	if (action == null) throw new NullPointerException();
3591	>	for (Node<K,V> p; (p = advance()) != null;)
3592	>	action.accept(p.val);
3593	>	}
3594	>
3595	>	public boolean tryAdvance(Consumer<? super V> action) {
3596	>	if (action == null) throw new NullPointerException();
3597	>	Node<K,V> p;
3598	>	if ((p = advance()) == null)
3599	>	return false;
3600	>	action.accept(p.val);
3601	>	return true;
3602	>	}
3603	>
3604	>	public long estimateSize() { return est; }
3605	>
3606	>	public int characteristics() {
3607	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3608		}
3609		}
3610
3611	+	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3612	+	implements Spliterator<Map.Entry<K,V>> {
3613	+	final ConcurrentHashMap<K,V> map; // To export MapEntry
3614	+	long est;               // size estimate
3615	+	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3616	+	long est, ConcurrentHashMap<K,V> map) {
3617	+	super(tab, size, index, limit);
3618	+	this.map = map;
3619	+	this.est = est;
3620	+	}
3621
3622	<	/* ---------------- Public operations -------------- */
3622	>	public EntrySpliterator<K,V> trySplit() {
3623	>	int i, f, h;
3624	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3625	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3626	>	f, est >>>= 1, map);
3627	>	}
3628
3629	<	/**
3630	<	* Constructs a new, empty map with the specified initial
3631	<	* capacity and the specified load factor.
3632	<	*
3633	<	* @param initialCapacity the initial capacity.  The actual
474	<	* initial capacity is rounded up to the nearest power of two.
475	<	* @param loadFactor  the load factor threshold, used to control resizing.
476	<	* @param segments the number of concurrently accessible segments. the
477	<	* actual number of segments is rounded to the next power of two.
478	<	* @throws IllegalArgumentException if the initial capacity is
479	<	* negative or the load factor or number of segments are
480	<	* nonpositive.
481	<	*/
482	<	public ConcurrentHashMap(int initialCapacity,
483	<	float loadFactor, int segments) {
484	<	if (!(loadFactor > 0) || initialCapacity < 0 || segments <= 0)
485	<	throw new IllegalArgumentException();
3629	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3630	>	if (action == null) throw new NullPointerException();
3631	>	for (Node<K,V> p; (p = advance()) != null; )
3632	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3633	>	}
3634
3635	<	// Find power-of-two sizes best matching arguments
3636	<	int sshift = 0;
3637	<	int ssize = 1;
3638	<	while (ssize < segments) {
3639	<	++sshift;
3640	<	ssize <<= 1;
3635	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3636	>	if (action == null) throw new NullPointerException();
3637	>	Node<K,V> p;
3638	>	if ((p = advance()) == null)
3639	>	return false;
3640	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3641	>	return true;
3642	>	}
3643	>
3644	>	public long estimateSize() { return est; }
3645	>
3646	>	public int characteristics() {
3647	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3648	>	Spliterator.NONNULL;
3649		}
3650	<	segmentShift = 32 - sshift;
495	<	segmentMask = ssize - 1;
496	<	this.segments = new Segment[ssize];
3650	>	}
3651
3652	<	if (initialCapacity > MAXIMUM_CAPACITY)
499	<	initialCapacity = MAXIMUM_CAPACITY;
500	<	int c = initialCapacity / ssize;
501	<	if (c * ssize < initialCapacity)
502	<	++c;
503	<	int cap = 1;
504	<	while (cap < c)
505	<	cap <<= 1;
3652	>	// Parallel bulk operations
3653
3654	<	for (int i = 0; i < this.segments.length; ++i)
3655	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
3654	>	/**
3655	>	* Computes initial batch value for bulk tasks. The returned value
3656	>	* is approximately exp2 of the number of times (minus one) to
3657	>	* split task by two before executing leaf action. This value is
3658	>	* faster to compute and more convenient to use as a guide to
3659	>	* splitting than is the depth, since it is used while dividing by
3660	>	* two anyway.
3661	>	*/
3662	>	final int batchFor(long b) {
3663	>	long n;
3664	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3665	>	return 0;
3666	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3667	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3668		}
3669
3670		/**
3671	<	* Constructs a new, empty map with the specified initial
513	<	* capacity,  and with default load factor and segments.
3671	>	* Performs the given action for each (key, value).
3672		*
3673	<	* @param initialCapacity the initial capacity of the
3674	<	* ConcurrentHashMap.
3675	<	* @throws IllegalArgumentException if the initial capacity of
3676	<	* elements is negative.
3673	>	* @param parallelismThreshold the (estimated) number of elements
3674	>	* needed for this operation to be executed in parallel
3675	>	* @param action the action
3676	>	* @since 1.8
3677		*/
3678	<	public ConcurrentHashMap(int initialCapacity) {
3679	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
3678	>	public void forEach(long parallelismThreshold,
3679	>	BiConsumer<? super K,? super V> action) {
3680	>	if (action == null) throw new NullPointerException();
3681	>	new ForEachMappingTask<K,V>
3682	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3683	>	action).invoke();
3684		}
3685
3686		/**
3687	<	* Constructs a new, empty map with a default initial capacity,
3688	<	* load factor, and number of segments.
3687	>	* Performs the given action for each non-null transformation
3688	>	* of each (key, value).
3689	>	*
3690	>	* @param parallelismThreshold the (estimated) number of elements
3691	>	* needed for this operation to be executed in parallel
3692	>	* @param transformer a function returning the transformation
3693	>	* for an element, or null if there is no transformation (in
3694	>	* which case the action is not applied)
3695	>	* @param action the action
3696	>	* @param <U> the return type of the transformer
3697	>	* @since 1.8
3698		*/
3699	<	public ConcurrentHashMap() {
3700	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
3699	>	public <U> void forEach(long parallelismThreshold,
3700	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3701	>	Consumer<? super U> action) {
3702	>	if (transformer == null || action == null)
3703	>	throw new NullPointerException();
3704	>	new ForEachTransformedMappingTask<K,V,U>
3705	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3706	>	transformer, action).invoke();
3707		}
3708
3709		/**
3710	<	* Constructs a new map with the same mappings as the given map.  The
3711	<	* map is created with a capacity of twice the number of mappings in
3712	<	* the given map or 11 (whichever is greater), and a default load factor.
3710	>	* Returns a non-null result from applying the given search
3711	>	* function on each (key, value), or null if none.  Upon
3712	>	* success, further element processing is suppressed and the
3713	>	* results of any other parallel invocations of the search
3714	>	* function are ignored.
3715	>	*
3716	>	* @param parallelismThreshold the (estimated) number of elements
3717	>	* needed for this operation to be executed in parallel
3718	>	* @param searchFunction a function returning a non-null
3719	>	* result on success, else null
3720	>	* @param <U> the return type of the search function
3721	>	* @return a non-null result from applying the given search
3722	>	* function on each (key, value), or null if none
3723	>	* @since 1.8
3724		*/
3725	<	public <A extends K, B extends V> ConcurrentHashMap(Map<A,B> t) {
3726	<	this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
3727	<	11),
3728	<	DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
3729	<	putAll(t);
3725	>	public <U> U search(long parallelismThreshold,
3726	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3727	>	if (searchFunction == null) throw new NullPointerException();
3728	>	return new SearchMappingsTask<K,V,U>
3729	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3730	>	searchFunction, new AtomicReference<U>()).invoke();
3731		}
3732
3733	<	// inherit Map javadoc
3734	<	public int size() {
3735	<	int c = 0;
3736	<	for (int i = 0; i < segments.length; ++i)
3737	<	c += segments[i].count;
3738	<	return c;
3733	>	/**
3734	>	* Returns the result of accumulating the given transformation
3735	>	* of all (key, value) pairs using the given reducer to
3736	>	* combine values, or null if none.
3737	>	*
3738	>	* @param parallelismThreshold the (estimated) number of elements
3739	>	* needed for this operation to be executed in parallel
3740	>	* @param transformer a function returning the transformation
3741	>	* for an element, or null if there is no transformation (in
3742	>	* which case it is not combined)
3743	>	* @param reducer a commutative associative combining function
3744	>	* @param <U> the return type of the transformer
3745	>	* @return the result of accumulating the given transformation
3746	>	* of all (key, value) pairs
3747	>	* @since 1.8
3748	>	*/
3749	>	public <U> U reduce(long parallelismThreshold,
3750	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3751	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3752	>	if (transformer == null || reducer == null)
3753	>	throw new NullPointerException();
3754	>	return new MapReduceMappingsTask<K,V,U>
3755	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3756	>	null, transformer, reducer).invoke();
3757		}
3758
3759	<	// inherit Map javadoc
3760	<	public boolean isEmpty() {
3761	<	for (int i = 0; i < segments.length; ++i)
3762	<	if (segments[i].count != 0)
3763	<	return false;
3764	<	return true;
3759	>	/**
3760	>	* Returns the result of accumulating the given transformation
3761	>	* of all (key, value) pairs using the given reducer to
3762	>	* combine values, and the given basis as an identity value.
3763	>	*
3764	>	* @param parallelismThreshold the (estimated) number of elements
3765	>	* needed for this operation to be executed in parallel
3766	>	* @param transformer a function returning the transformation
3767	>	* for an element
3768	>	* @param basis the identity (initial default value) for the reduction
3769	>	* @param reducer a commutative associative combining function
3770	>	* @return the result of accumulating the given transformation
3771	>	* of all (key, value) pairs
3772	>	* @since 1.8
3773	>	*/
3774	>	public double reduceToDouble(long parallelismThreshold,
3775	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3776	>	double basis,
3777	>	DoubleBinaryOperator reducer) {
3778	>	if (transformer == null || reducer == null)
3779	>	throw new NullPointerException();
3780	>	return new MapReduceMappingsToDoubleTask<K,V>
3781	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3782	>	null, transformer, basis, reducer).invoke();
3783		}
3784
3785		/**
3786	<	* Returns the value to which the specified key is mapped in this table.
3786	>	* Returns the result of accumulating the given transformation
3787	>	* of all (key, value) pairs using the given reducer to
3788	>	* combine values, and the given basis as an identity value.
3789		*
3790	<	* @param   key   a key in the table.
3791	<	* @return  the value to which the key is mapped in this table;
3792	<	*          <code>null</code> if the key is not mapped to any value in
3793	<	*          this table.
3794	<	* @throws  NullPointerException  if the key is
3795	<	*               <code>null</code>.
3796	<	* @see     #put(Object, Object)
3790	>	* @param parallelismThreshold the (estimated) number of elements
3791	>	* needed for this operation to be executed in parallel
3792	>	* @param transformer a function returning the transformation
3793	>	* for an element
3794	>	* @param basis the identity (initial default value) for the reduction
3795	>	* @param reducer a commutative associative combining function
3796	>	* @return the result of accumulating the given transformation
3797	>	* of all (key, value) pairs
3798	>	* @since 1.8
3799		*/
3800	<	public V get(Object key) {
3801	<	int hash = hash(key); // throws NullPointerException if key null
3802	<	return segmentFor(hash).get((K) key, hash);
3800	>	public long reduceToLong(long parallelismThreshold,
3801	>	ToLongBiFunction<? super K, ? super V> transformer,
3802	>	long basis,
3803	>	LongBinaryOperator reducer) {
3804	>	if (transformer == null || reducer == null)
3805	>	throw new NullPointerException();
3806	>	return new MapReduceMappingsToLongTask<K,V>
3807	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3808	>	null, transformer, basis, reducer).invoke();
3809		}
3810
3811		/**
3812	<	* Tests if the specified object is a key in this table.
3812	>	* Returns the result of accumulating the given transformation
3813	>	* of all (key, value) pairs using the given reducer to
3814	>	* combine values, and the given basis as an identity value.
3815		*
3816	<	* @param   key   possible key.
3817	<	* @return  <code>true</code> if and only if the specified object
3818	<	*          is a key in this table, as determined by the
3819	<	*          <tt>equals</tt> method; <code>false</code> otherwise.
3820	<	* @throws  NullPointerException  if the key is
3821	<	*               <code>null</code>.
3822	<	* @see     #contains(Object)
3816	>	* @param parallelismThreshold the (estimated) number of elements
3817	>	* needed for this operation to be executed in parallel
3818	>	* @param transformer a function returning the transformation
3819	>	* for an element
3820	>	* @param basis the identity (initial default value) for the reduction
3821	>	* @param reducer a commutative associative combining function
3822	>	* @return the result of accumulating the given transformation
3823	>	* of all (key, value) pairs
3824	>	* @since 1.8
3825		*/
3826	<	public boolean containsKey(Object key) {
3827	<	int hash = hash(key); // throws NullPointerException if key null
3828	<	return segmentFor(hash).containsKey(key, hash);
3826	>	public int reduceToInt(long parallelismThreshold,
3827	>	ToIntBiFunction<? super K, ? super V> transformer,
3828	>	int basis,
3829	>	IntBinaryOperator reducer) {
3830	>	if (transformer == null || reducer == null)
3831	>	throw new NullPointerException();
3832	>	return new MapReduceMappingsToIntTask<K,V>
3833	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3834	>	null, transformer, basis, reducer).invoke();
3835		}
3836
3837		/**
3838	<	* Returns <tt>true</tt> if this map maps one or more keys to the
594	<	* specified value. Note: This method requires a full internal
595	<	* traversal of the hash table, and so is much slower than
596	<	* method <tt>containsKey</tt>.
3838	>	* Performs the given action for each key.
3839		*
3840	<	* @param value value whose presence in this map is to be tested.
3841	<	* @return <tt>true</tt> if this map maps one or more keys to the
3842	<	* specified value.
3843	<	* @throws  NullPointerException  if the value is <code>null</code>.
3840	>	* @param parallelismThreshold the (estimated) number of elements
3841	>	* needed for this operation to be executed in parallel
3842	>	* @param action the action
3843	>	* @since 1.8
3844		*/
3845	<	public boolean containsValue(Object value) {
3846	<	if (value == null)
3845	>	public void forEachKey(long parallelismThreshold,
3846	>	Consumer<? super K> action) {
3847	>	if (action == null) throw new NullPointerException();
3848	>	new ForEachKeyTask<K,V>
3849	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3850	>	action).invoke();
3851	>	}
3852	>
3853	>	/**
3854	>	* Performs the given action for each non-null transformation
3855	>	* of each key.
3856	>	*
3857	>	* @param parallelismThreshold the (estimated) number of elements
3858	>	* needed for this operation to be executed in parallel
3859	>	* @param transformer a function returning the transformation
3860	>	* for an element, or null if there is no transformation (in
3861	>	* which case the action is not applied)
3862	>	* @param action the action
3863	>	* @param <U> the return type of the transformer
3864	>	* @since 1.8
3865	>	*/
3866	>	public <U> void forEachKey(long parallelismThreshold,
3867	>	Function<? super K, ? extends U> transformer,
3868	>	Consumer<? super U> action) {
3869	>	if (transformer == null || action == null)
3870		throw new NullPointerException();
3871	+	new ForEachTransformedKeyTask<K,V,U>
3872	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3873	+	transformer, action).invoke();
3874	+	}
3875
3876	<	for (int i = 0; i < segments.length; ++i) {
3877	<	if (segments[i].containsValue(value))
3878	<	return true;
3879	<	}
3880	<	return false;
3876	>	/**
3877	>	* Returns a non-null result from applying the given search
3878	>	* function on each key, or null if none. Upon success,
3879	>	* further element processing is suppressed and the results of
3880	>	* any other parallel invocations of the search function are
3881	>	* ignored.
3882	>	*
3883	>	* @param parallelismThreshold the (estimated) number of elements
3884	>	* needed for this operation to be executed in parallel
3885	>	* @param searchFunction a function returning a non-null
3886	>	* result on success, else null
3887	>	* @param <U> the return type of the search function
3888	>	* @return a non-null result from applying the given search
3889	>	* function on each key, or null if none
3890	>	* @since 1.8
3891	>	*/
3892	>	public <U> U searchKeys(long parallelismThreshold,
3893	>	Function<? super K, ? extends U> searchFunction) {
3894	>	if (searchFunction == null) throw new NullPointerException();
3895	>	return new SearchKeysTask<K,V,U>
3896	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3897	>	searchFunction, new AtomicReference<U>()).invoke();
3898		}
3899	+
3900		/**
3901	<	* Tests if some key maps into the specified value in this table.
3902	<	* This operation is more expensive than the <code>containsKey</code>
616	<	* method.<p>
3901	>	* Returns the result of accumulating all keys using the given
3902	>	* reducer to combine values, or null if none.
3903		*
3904	<	* Note that this method is identical in functionality to containsValue,
3905	<	* (which is part of the Map interface in the collections framework).
3904	>	* @param parallelismThreshold the (estimated) number of elements
3905	>	* needed for this operation to be executed in parallel
3906	>	* @param reducer a commutative associative combining function
3907	>	* @return the result of accumulating all keys using the given
3908	>	* reducer to combine values, or null if none
3909	>	* @since 1.8
3910	>	*/
3911	>	public K reduceKeys(long parallelismThreshold,
3912	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3913	>	if (reducer == null) throw new NullPointerException();
3914	>	return new ReduceKeysTask<K,V>
3915	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3916	>	null, reducer).invoke();
3917	>	}
3918	>
3919	>	/**
3920	>	* Returns the result of accumulating the given transformation
3921	>	* of all keys using the given reducer to combine values, or
3922	>	* null if none.
3923		*
3924	<	* @param      value   a value to search for.
3925	<	* @return     <code>true</code> if and only if some key maps to the
3926	<	*             <code>value</code> argument in this table as
3927	<	*             determined by the <tt>equals</tt> method;
3928	<	*             <code>false</code> otherwise.
3929	<	* @throws  NullPointerException  if the value is <code>null</code>.
3930	<	* @see        #containsKey(Object)
3931	<	* @see        #containsValue(Object)
3932	<	* @see   Map
3924	>	* @param parallelismThreshold the (estimated) number of elements
3925	>	* needed for this operation to be executed in parallel
3926	>	* @param transformer a function returning the transformation
3927	>	* for an element, or null if there is no transformation (in
3928	>	* which case it is not combined)
3929	>	* @param reducer a commutative associative combining function
3930	>	* @param <U> the return type of the transformer
3931	>	* @return the result of accumulating the given transformation
3932	>	* of all keys
3933	>	* @since 1.8
3934		*/
3935	<	public boolean contains(Object value) {
3936	<	return containsValue(value);
3935	>	public <U> U reduceKeys(long parallelismThreshold,
3936	>	Function<? super K, ? extends U> transformer,
3937	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3938	>	if (transformer == null || reducer == null)
3939	>	throw new NullPointerException();
3940	>	return new MapReduceKeysTask<K,V,U>
3941	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3942	>	null, transformer, reducer).invoke();
3943		}
3944
3945		/**
3946	<	* Maps the specified <code>key</code> to the specified
3947	<	* <code>value</code> in this table. Neither the key nor the
3948	<	* value can be <code>null</code>. <p>
3946	>	* Returns the result of accumulating the given transformation
3947	>	* of all keys using the given reducer to combine values, and
3948	>	* the given basis as an identity value.
3949		*
3950	<	* The value can be retrieved by calling the <code>get</code> method
3951	<	* with a key that is equal to the original key.
3950	>	* @param parallelismThreshold the (estimated) number of elements
3951	>	* needed for this operation to be executed in parallel
3952	>	* @param transformer a function returning the transformation
3953	>	* for an element
3954	>	* @param basis the identity (initial default value) for the reduction
3955	>	* @param reducer a commutative associative combining function
3956	>	* @return the result of accumulating the given transformation
3957	>	* of all keys
3958	>	* @since 1.8
3959	>	*/
3960	>	public double reduceKeysToDouble(long parallelismThreshold,
3961	>	ToDoubleFunction<? super K> transformer,
3962	>	double basis,
3963	>	DoubleBinaryOperator reducer) {
3964	>	if (transformer == null || reducer == null)
3965	>	throw new NullPointerException();
3966	>	return new MapReduceKeysToDoubleTask<K,V>
3967	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3968	>	null, transformer, basis, reducer).invoke();
3969	>	}
3970	>
3971	>	/**
3972	>	* Returns the result of accumulating the given transformation
3973	>	* of all keys using the given reducer to combine values, and
3974	>	* the given basis as an identity value.
3975		*
3976	<	* @param      key     the table key.
3977	<	* @param      value   the value.
3978	<	* @return     the previous value of the specified key in this table,
3979	<	*             or <code>null</code> if it did not have one.
3980	<	* @throws  NullPointerException  if the key or value is
3981	<	*               <code>null</code>.
3982	<	* @see     Object#equals(Object)
3983	<	* @see     #get(Object)
3976	>	* @param parallelismThreshold the (estimated) number of elements
3977	>	* needed for this operation to be executed in parallel
3978	>	* @param transformer a function returning the transformation
3979	>	* for an element
3980	>	* @param basis the identity (initial default value) for the reduction
3981	>	* @param reducer a commutative associative combining function
3982	>	* @return the result of accumulating the given transformation
3983	>	* of all keys
3984	>	* @since 1.8
3985		*/
3986	<	public V put(K key, V value) {
3987	<	if (value == null)
3986	>	public long reduceKeysToLong(long parallelismThreshold,
3987	>	ToLongFunction<? super K> transformer,
3988	>	long basis,
3989	>	LongBinaryOperator reducer) {
3990	>	if (transformer == null || reducer == null)
3991		throw new NullPointerException();
3992	<	int hash = hash(key);
3993	<	return segmentFor(hash).put(key, hash, value, false);
3992	>	return new MapReduceKeysToLongTask<K,V>
3993	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3994	>	null, transformer, basis, reducer).invoke();
3995		}
3996
3997		/**
3998	<	* If the specified key is not already associated
3999	<	* with a value, associate it with the given value.
4000	<	* This is equivalent to
663	<	* <pre>
664	<	*   if (!map.containsKey(key)) map.put(key, value);
665	<	*   return get(key);
666	<	* </pre>
667	<	* Except that the action is performed atomically.
668	<	* @param key key with which the specified value is to be associated.
669	<	* @param value value to be associated with the specified key.
670	<	* @return previous value associated with specified key, or <tt>null</tt>
671	<	*         if there was no mapping for key.  A <tt>null</tt> return can
672	<	*         also indicate that the map previously associated <tt>null</tt>
673	<	*         with the specified key, if the implementation supports
674	<	*         <tt>null</tt> values.
675	<	*
676	<	* @throws NullPointerException this map does not permit <tt>null</tt>
677	<	*            keys or values, and the specified key or value is
678	<	*            <tt>null</tt>.
3998	>	* Returns the result of accumulating the given transformation
3999	>	* of all keys using the given reducer to combine values, and
4000	>	* the given basis as an identity value.
4001		*
4002	<	**/
4003	<	public V putIfAbsent(K key, V value) {
4004	<	if (value == null)
4002	>	* @param parallelismThreshold the (estimated) number of elements
4003	>	* needed for this operation to be executed in parallel
4004	>	* @param transformer a function returning the transformation
4005	>	* for an element
4006	>	* @param basis the identity (initial default value) for the reduction
4007	>	* @param reducer a commutative associative combining function
4008	>	* @return the result of accumulating the given transformation
4009	>	* of all keys
4010	>	* @since 1.8
4011	>	*/
4012	>	public int reduceKeysToInt(long parallelismThreshold,
4013	>	ToIntFunction<? super K> transformer,
4014	>	int basis,
4015	>	IntBinaryOperator reducer) {
4016	>	if (transformer == null || reducer == null)
4017		throw new NullPointerException();
4018	<	int hash = hash(key);
4019	<	return segmentFor(hash).put(key, hash, value, true);
4018	>	return new MapReduceKeysToIntTask<K,V>
4019	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4020	>	null, transformer, basis, reducer).invoke();
4021		}
4022
4023	+	/**
4024	+	* Performs the given action for each value.
4025	+	*
4026	+	* @param parallelismThreshold the (estimated) number of elements
4027	+	* needed for this operation to be executed in parallel
4028	+	* @param action the action
4029	+	* @since 1.8
4030	+	*/
4031	+	public void forEachValue(long parallelismThreshold,
4032	+	Consumer<? super V> action) {
4033	+	if (action == null)
4034	+	throw new NullPointerException();
4035	+	new ForEachValueTask<K,V>
4036	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4037	+	action).invoke();
4038	+	}
4039
4040		/**
4041	<	* Copies all of the mappings from the specified map to this one.
4041	>	* Performs the given action for each non-null transformation
4042	>	* of each value.
4043		*
4044	<	* These mappings replace any mappings that this map had for any of the
4045	<	* keys currently in the specified Map.
4044	>	* @param parallelismThreshold the (estimated) number of elements
4045	>	* needed for this operation to be executed in parallel
4046	>	* @param transformer a function returning the transformation
4047	>	* for an element, or null if there is no transformation (in
4048	>	* which case the action is not applied)
4049	>	* @param action the action
4050	>	* @param <U> the return type of the transformer
4051	>	* @since 1.8
4052	>	*/
4053	>	public <U> void forEachValue(long parallelismThreshold,
4054	>	Function<? super V, ? extends U> transformer,
4055	>	Consumer<? super U> action) {
4056	>	if (transformer == null || action == null)
4057	>	throw new NullPointerException();
4058	>	new ForEachTransformedValueTask<K,V,U>
4059	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4060	>	transformer, action).invoke();
4061	>	}
4062	>
4063	>	/**
4064	>	* Returns a non-null result from applying the given search
4065	>	* function on each value, or null if none.  Upon success,
4066	>	* further element processing is suppressed and the results of
4067	>	* any other parallel invocations of the search function are
4068	>	* ignored.
4069		*
4070	<	* @param t Mappings to be stored in this map.
4070	>	* @param parallelismThreshold the (estimated) number of elements
4071	>	* needed for this operation to be executed in parallel
4072	>	* @param searchFunction a function returning a non-null
4073	>	* result on success, else null
4074	>	* @param <U> the return type of the search function
4075	>	* @return a non-null result from applying the given search
4076	>	* function on each value, or null if none
4077	>	* @since 1.8
4078		*/
4079	<	public void putAll(Map<? extends K, ? extends V> t) {
4080	<	Iterator<Map.Entry<? extends K, ? extends V>> it = t.entrySet().iterator();
4081	<	while (it.hasNext()) {
4082	<	Entry<? extends K, ? extends V> e = it.next();
4083	<	put(e.getKey(), e.getValue());
4084	<	}
4079	>	public <U> U searchValues(long parallelismThreshold,
4080	>	Function<? super V, ? extends U> searchFunction) {
4081	>	if (searchFunction == null) throw new NullPointerException();
4082	>	return new SearchValuesTask<K,V,U>
4083	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4084	>	searchFunction, new AtomicReference<U>()).invoke();
4085		}
4086
4087		/**
4088	<	* Removes the key (and its corresponding value) from this
4089	<	* table. This method does nothing if the key is not in the table.
4088	>	* Returns the result of accumulating all values using the
4089	>	* given reducer to combine values, or null if none.
4090		*
4091	<	* @param   key   the key that needs to be removed.
4092	<	* @return  the value to which the key had been mapped in this table,
4093	<	*          or <code>null</code> if the key did not have a mapping.
4094	<	* @throws  NullPointerException  if the key is
4095	<	*               <code>null</code>.
4091	>	* @param parallelismThreshold the (estimated) number of elements
4092	>	* needed for this operation to be executed in parallel
4093	>	* @param reducer a commutative associative combining function
4094	>	* @return the result of accumulating all values
4095	>	* @since 1.8
4096		*/
4097	<	public V remove(Object key) {
4098	<	int hash = hash(key);
4099	<	return segmentFor(hash).remove(key, hash, null);
4097	>	public V reduceValues(long parallelismThreshold,
4098	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4099	>	if (reducer == null) throw new NullPointerException();
4100	>	return new ReduceValuesTask<K,V>
4101	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4102	>	null, reducer).invoke();
4103		}
4104
4105		/**
4106	<	* Removes the (key, value) pair from this
4107	<	* table. This method does nothing if the key is not in the table,
4108	<	* or if the key is associated with a different value.
4109	<	*
4110	<	* @param   key   the key that needs to be removed.
4111	<	* @param   value   the associated value. If the value is null,
4112	<	*                   it means "any value".
4113	<	* @return  the value to which the key had been mapped in this table,
4114	<	*          or <code>null</code> if the key did not have a mapping.
4115	<	* @throws  NullPointerException  if the key is
4116	<	*               <code>null</code>.
4106	>	* Returns the result of accumulating the given transformation
4107	>	* of all values using the given reducer to combine values, or
4108	>	* null if none.
4109	>	*
4110	>	* @param parallelismThreshold the (estimated) number of elements
4111	>	* needed for this operation to be executed in parallel
4112	>	* @param transformer a function returning the transformation
4113	>	* for an element, or null if there is no transformation (in
4114	>	* which case it is not combined)
4115	>	* @param reducer a commutative associative combining function
4116	>	* @param <U> the return type of the transformer
4117	>	* @return the result of accumulating the given transformation
4118	>	* of all values
4119	>	* @since 1.8
4120		*/
4121	<	public boolean remove(Object key, Object value) {
4122	<	int hash = hash(key);
4123	<	return segmentFor(hash).remove(key, hash, value) != null;
4121	>	public <U> U reduceValues(long parallelismThreshold,
4122	>	Function<? super V, ? extends U> transformer,
4123	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4124	>	if (transformer == null || reducer == null)
4125	>	throw new NullPointerException();
4126	>	return new MapReduceValuesTask<K,V,U>
4127	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4128	>	null, transformer, reducer).invoke();
4129		}
4130
4131		/**
4132	<	* Removes all mappings from this map.
4132	>	* Returns the result of accumulating the given transformation
4133	>	* of all values using the given reducer to combine values,
4134	>	* and the given basis as an identity value.
4135	>	*
4136	>	* @param parallelismThreshold the (estimated) number of elements
4137	>	* needed for this operation to be executed in parallel
4138	>	* @param transformer a function returning the transformation
4139	>	* for an element
4140	>	* @param basis the identity (initial default value) for the reduction
4141	>	* @param reducer a commutative associative combining function
4142	>	* @return the result of accumulating the given transformation
4143	>	* of all values
4144	>	* @since 1.8
4145		*/
4146	<	public void clear() {
4147	<	for (int i = 0; i < segments.length; ++i)
4148	<	segments[i].clear();
4146	>	public double reduceValuesToDouble(long parallelismThreshold,
4147	>	ToDoubleFunction<? super V> transformer,
4148	>	double basis,
4149	>	DoubleBinaryOperator reducer) {
4150	>	if (transformer == null || reducer == null)
4151	>	throw new NullPointerException();
4152	>	return new MapReduceValuesToDoubleTask<K,V>
4153	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4154	>	null, transformer, basis, reducer).invoke();
4155		}
4156
4157	+	/**
4158	+	* Returns the result of accumulating the given transformation
4159	+	* of all values using the given reducer to combine values,
4160	+	* and the given basis as an identity value.
4161	+	*
4162	+	* @param parallelismThreshold the (estimated) number of elements
4163	+	* needed for this operation to be executed in parallel
4164	+	* @param transformer a function returning the transformation
4165	+	* for an element
4166	+	* @param basis the identity (initial default value) for the reduction
4167	+	* @param reducer a commutative associative combining function
4168	+	* @return the result of accumulating the given transformation
4169	+	* of all values
4170	+	* @since 1.8
4171	+	*/
4172	+	public long reduceValuesToLong(long parallelismThreshold,
4173	+	ToLongFunction<? super V> transformer,
4174	+	long basis,
4175	+	LongBinaryOperator reducer) {
4176	+	if (transformer == null || reducer == null)
4177	+	throw new NullPointerException();
4178	+	return new MapReduceValuesToLongTask<K,V>
4179	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4180	+	null, transformer, basis, reducer).invoke();
4181	+	}
4182
4183		/**
4184	<	* Returns a shallow copy of this
4185	<	* <tt>ConcurrentHashMap</tt> instance: the keys and
4186	<	* values themselves are not cloned.
4184	>	* Returns the result of accumulating the given transformation
4185	>	* of all values using the given reducer to combine values,
4186	>	* and the given basis as an identity value.
4187		*
4188	<	* @return a shallow copy of this map.
4188	>	* @param parallelismThreshold the (estimated) number of elements
4189	>	* needed for this operation to be executed in parallel
4190	>	* @param transformer a function returning the transformation
4191	>	* for an element
4192	>	* @param basis the identity (initial default value) for the reduction
4193	>	* @param reducer a commutative associative combining function
4194	>	* @return the result of accumulating the given transformation
4195	>	* of all values
4196	>	* @since 1.8
4197		*/
4198	<	public Object clone() {
4199	<	// We cannot call super.clone, since it would share final
4200	<	// segments array, and there's no way to reassign finals.
4198	>	public int reduceValuesToInt(long parallelismThreshold,
4199	>	ToIntFunction<? super V> transformer,
4200	>	int basis,
4201	>	IntBinaryOperator reducer) {
4202	>	if (transformer == null || reducer == null)
4203	>	throw new NullPointerException();
4204	>	return new MapReduceValuesToIntTask<K,V>
4205	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4206	>	null, transformer, basis, reducer).invoke();
4207	>	}
4208
4209	<	float lf = segments[0].loadFactor;
4210	<	int segs = segments.length;
4211	<	int cap = (int)(size() / lf);
4212	<	if (cap < segs) cap = segs;
4213	<	ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
4214	<	t.putAll(this);
4215	<	return t;
4209	>	/**
4210	>	* Performs the given action for each entry.
4211	>	*
4212	>	* @param parallelismThreshold the (estimated) number of elements
4213	>	* needed for this operation to be executed in parallel
4214	>	* @param action the action
4215	>	* @since 1.8
4216	>	*/
4217	>	public void forEachEntry(long parallelismThreshold,
4218	>	Consumer<? super Map.Entry<K,V>> action) {
4219	>	if (action == null) throw new NullPointerException();
4220	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4221	>	action).invoke();
4222		}
4223
4224		/**
4225	<	* Returns a set view of the keys contained in this map.  The set is
4226	<	* backed by the map, so changes to the map are reflected in the set, and
770	<	* vice-versa.  The set supports element removal, which removes the
771	<	* corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
772	<	* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
773	<	* <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
774	<	* <tt>addAll</tt> operations.
775	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
776	<	* will never throw {@link java.util.ConcurrentModificationException},
777	<	* and guarantees to traverse elements as they existed upon
778	<	* construction of the iterator, and may (but is not guaranteed to)
779	<	* reflect any modifications subsequent to construction.
4225	>	* Performs the given action for each non-null transformation
4226	>	* of each entry.
4227		*
4228	<	* @return a set view of the keys contained in this map.
4228	>	* @param parallelismThreshold the (estimated) number of elements
4229	>	* needed for this operation to be executed in parallel
4230	>	* @param transformer a function returning the transformation
4231	>	* for an element, or null if there is no transformation (in
4232	>	* which case the action is not applied)
4233	>	* @param action the action
4234	>	* @param <U> the return type of the transformer
4235	>	* @since 1.8
4236		*/
4237	<	public Set<K> keySet() {
4238	<	Set<K> ks = keySet;
4239	<	return (ks != null) ? ks : (keySet = new KeySet());
4237	>	public <U> void forEachEntry(long parallelismThreshold,
4238	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4239	>	Consumer<? super U> action) {
4240	>	if (transformer == null || action == null)
4241	>	throw new NullPointerException();
4242	>	new ForEachTransformedEntryTask<K,V,U>
4243	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4244	>	transformer, action).invoke();
4245		}
4246
4247	+	/**
4248	+	* Returns a non-null result from applying the given search
4249	+	* function on each entry, or null if none.  Upon success,
4250	+	* further element processing is suppressed and the results of
4251	+	* any other parallel invocations of the search function are
4252	+	* ignored.
4253	+	*
4254	+	* @param parallelismThreshold the (estimated) number of elements
4255	+	* needed for this operation to be executed in parallel
4256	+	* @param searchFunction a function returning a non-null
4257	+	* result on success, else null
4258	+	* @param <U> the return type of the search function
4259	+	* @return a non-null result from applying the given search
4260	+	* function on each entry, or null if none
4261	+	* @since 1.8
4262	+	*/
4263	+	public <U> U searchEntries(long parallelismThreshold,
4264	+	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4265	+	if (searchFunction == null) throw new NullPointerException();
4266	+	return new SearchEntriesTask<K,V,U>
4267	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4268	+	searchFunction, new AtomicReference<U>()).invoke();
4269	+	}
4270
4271		/**
4272	<	* Returns a collection view of the values contained in this map.  The
4273	<	* collection is backed by the map, so changes to the map are reflected in
792	<	* the collection, and vice-versa.  The collection supports element
793	<	* removal, which removes the corresponding mapping from this map, via the
794	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
795	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
796	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
797	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
798	<	* will never throw {@link java.util.ConcurrentModificationException},
799	<	* and guarantees to traverse elements as they existed upon
800	<	* construction of the iterator, and may (but is not guaranteed to)
801	<	* reflect any modifications subsequent to construction.
4272	>	* Returns the result of accumulating all entries using the
4273	>	* given reducer to combine values, or null if none.
4274		*
4275	<	* @return a collection view of the values contained in this map.
4275	>	* @param parallelismThreshold the (estimated) number of elements
4276	>	* needed for this operation to be executed in parallel
4277	>	* @param reducer a commutative associative combining function
4278	>	* @return the result of accumulating all entries
4279	>	* @since 1.8
4280		*/
4281	<	public Collection<V> values() {
4282	<	Collection<V> vs = values;
4283	<	return (vs != null) ? vs : (values = new Values());
4281	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4282	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4283	>	if (reducer == null) throw new NullPointerException();
4284	>	return new ReduceEntriesTask<K,V>
4285	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4286	>	null, reducer).invoke();
4287		}
4288
4289	+	/**
4290	+	* Returns the result of accumulating the given transformation
4291	+	* of all entries using the given reducer to combine values,
4292	+	* or null if none.
4293	+	*
4294	+	* @param parallelismThreshold the (estimated) number of elements
4295	+	* needed for this operation to be executed in parallel
4296	+	* @param transformer a function returning the transformation
4297	+	* for an element, or null if there is no transformation (in
4298	+	* which case it is not combined)
4299	+	* @param reducer a commutative associative combining function
4300	+	* @param <U> the return type of the transformer
4301	+	* @return the result of accumulating the given transformation
4302	+	* of all entries
4303	+	* @since 1.8
4304	+	*/
4305	+	public <U> U reduceEntries(long parallelismThreshold,
4306	+	Function<Map.Entry<K,V>, ? extends U> transformer,
4307	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4308	+	if (transformer == null || reducer == null)
4309	+	throw new NullPointerException();
4310	+	return new MapReduceEntriesTask<K,V,U>
4311	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4312	+	null, transformer, reducer).invoke();
4313	+	}
4314
4315		/**
4316	<	* Returns a collection view of the mappings contained in this map.  Each
4317	<	* element in the returned collection is a <tt>Map.Entry</tt>.  The
4318	<	* collection is backed by the map, so changes to the map are reflected in
815	<	* the collection, and vice-versa.  The collection supports element
816	<	* removal, which removes the corresponding mapping from the map, via the
817	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
818	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
819	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
820	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
821	<	* will never throw {@link java.util.ConcurrentModificationException},
822	<	* and guarantees to traverse elements as they existed upon
823	<	* construction of the iterator, and may (but is not guaranteed to)
824	<	* reflect any modifications subsequent to construction.
4316	>	* Returns the result of accumulating the given transformation
4317	>	* of all entries using the given reducer to combine values,
4318	>	* and the given basis as an identity value.
4319		*
4320	<	* @return a collection view of the mappings contained in this map.
4320	>	* @param parallelismThreshold the (estimated) number of elements
4321	>	* needed for this operation to be executed in parallel
4322	>	* @param transformer a function returning the transformation
4323	>	* for an element
4324	>	* @param basis the identity (initial default value) for the reduction
4325	>	* @param reducer a commutative associative combining function
4326	>	* @return the result of accumulating the given transformation
4327	>	* of all entries
4328	>	* @since 1.8
4329		*/
4330	<	public Set<Map.Entry<K,V>> entrySet() {
4331	<	Set<Map.Entry<K,V>> es = entrySet;
4332	<	return (es != null) ? es : (entrySet = new EntrySet());
4330	>	public double reduceEntriesToDouble(long parallelismThreshold,
4331	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4332	>	double basis,
4333	>	DoubleBinaryOperator reducer) {
4334	>	if (transformer == null || reducer == null)
4335	>	throw new NullPointerException();
4336	>	return new MapReduceEntriesToDoubleTask<K,V>
4337	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4338	>	null, transformer, basis, reducer).invoke();
4339		}
4340
4341	+	/**
4342	+	* Returns the result of accumulating the given transformation
4343	+	* of all entries using the given reducer to combine values,
4344	+	* and the given basis as an identity value.
4345	+	*
4346	+	* @param parallelismThreshold the (estimated) number of elements
4347	+	* needed for this operation to be executed in parallel
4348	+	* @param transformer a function returning the transformation
4349	+	* for an element
4350	+	* @param basis the identity (initial default value) for the reduction
4351	+	* @param reducer a commutative associative combining function
4352	+	* @return the result of accumulating the given transformation
4353	+	* of all entries
4354	+	* @since 1.8
4355	+	*/
4356	+	public long reduceEntriesToLong(long parallelismThreshold,
4357	+	ToLongFunction<Map.Entry<K,V>> transformer,
4358	+	long basis,
4359	+	LongBinaryOperator reducer) {
4360	+	if (transformer == null || reducer == null)
4361	+	throw new NullPointerException();
4362	+	return new MapReduceEntriesToLongTask<K,V>
4363	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4364	+	null, transformer, basis, reducer).invoke();
4365	+	}
4366
4367		/**
4368	<	* Returns an enumeration of the keys in this table.
4368	>	* Returns the result of accumulating the given transformation
4369	>	* of all entries using the given reducer to combine values,
4370	>	* and the given basis as an identity value.
4371		*
4372	<	* @return  an enumeration of the keys in this table.
4373	<	* @see     Enumeration
4374	<	* @see     #elements()
4375	<	* @see     #keySet()
4376	<	* @see     Map
4372	>	* @param parallelismThreshold the (estimated) number of elements
4373	>	* needed for this operation to be executed in parallel
4374	>	* @param transformer a function returning the transformation
4375	>	* for an element
4376	>	* @param basis the identity (initial default value) for the reduction
4377	>	* @param reducer a commutative associative combining function
4378	>	* @return the result of accumulating the given transformation
4379	>	* of all entries
4380	>	* @since 1.8
4381		*/
4382	<	public Enumeration<K> keys() {
4383	<	return new KeyIterator();
4382	>	public int reduceEntriesToInt(long parallelismThreshold,
4383	>	ToIntFunction<Map.Entry<K,V>> transformer,
4384	>	int basis,
4385	>	IntBinaryOperator reducer) {
4386	>	if (transformer == null || reducer == null)
4387	>	throw new NullPointerException();
4388	>	return new MapReduceEntriesToIntTask<K,V>
4389	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4390	>	null, transformer, basis, reducer).invoke();
4391		}
4392
4393	+
4394	+	/* ----------------Views -------------- */
4395	+
4396		/**
4397	<	* Returns an enumeration of the values in this table.
4398	<	* Use the Enumeration methods on the returned object to fetch the elements
4399	<	* sequentially.
4397	>	* Base class for views.
4398	>	*/
4399	>	abstract static class CollectionView<K,V,E>
4400	>	implements Collection<E>, java.io.Serializable {
4401	>	private static final long serialVersionUID = 7249069246763182397L;
4402	>	final ConcurrentHashMap<K,V> map;
4403	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4404	>
4405	>	/**
4406	>	* Returns the map backing this view.
4407	>	*
4408	>	* @return the map backing this view
4409	>	*/
4410	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4411	>
4412	>	/**
4413	>	* Removes all of the elements from this view, by removing all
4414	>	* the mappings from the map backing this view.
4415	>	*/
4416	>	public final void clear()      { map.clear(); }
4417	>	public final int size()        { return map.size(); }
4418	>	public final boolean isEmpty() { return map.isEmpty(); }
4419	>
4420	>	// implementations below rely on concrete classes supplying these
4421	>	// abstract methods
4422	>	/**
4423	>	* Returns an iterator over the elements in this collection.
4424	>	*
4425	>	* <p>The returned iterator is
4426	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4427	>	*
4428	>	* @return an iterator over the elements in this collection
4429	>	*/
4430	>	public abstract Iterator<E> iterator();
4431	>	public abstract boolean contains(Object o);
4432	>	public abstract boolean remove(Object o);
4433	>
4434	>	private static final String OOME_MSG = "Required array size too large";
4435	>
4436	>	public final Object[] toArray() {
4437	>	long sz = map.mappingCount();
4438	>	if (sz > MAX_ARRAY_SIZE)
4439	>	throw new OutOfMemoryError(OOME_MSG);
4440	>	int n = (int)sz;
4441	>	Object[] r = new Object[n];
4442	>	int i = 0;
4443	>	for (E e : this) {
4444	>	if (i == n) {
4445	>	if (n >= MAX_ARRAY_SIZE)
4446	>	throw new OutOfMemoryError(OOME_MSG);
4447	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4448	>	n = MAX_ARRAY_SIZE;
4449	>	else
4450	>	n += (n >>> 1) + 1;
4451	>	r = Arrays.copyOf(r, n);
4452	>	}
4453	>	r[i++] = e;
4454	>	}
4455	>	return (i == n) ? r : Arrays.copyOf(r, i);
4456	>	}
4457	>
4458	>	@SuppressWarnings("unchecked")
4459	>	public final <T> T[] toArray(T[] a) {
4460	>	long sz = map.mappingCount();
4461	>	if (sz > MAX_ARRAY_SIZE)
4462	>	throw new OutOfMemoryError(OOME_MSG);
4463	>	int m = (int)sz;
4464	>	T[] r = (a.length >= m) ? a :
4465	>	(T[])java.lang.reflect.Array
4466	>	.newInstance(a.getClass().getComponentType(), m);
4467	>	int n = r.length;
4468	>	int i = 0;
4469	>	for (E e : this) {
4470	>	if (i == n) {
4471	>	if (n >= MAX_ARRAY_SIZE)
4472	>	throw new OutOfMemoryError(OOME_MSG);
4473	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4474	>	n = MAX_ARRAY_SIZE;
4475	>	else
4476	>	n += (n >>> 1) + 1;
4477	>	r = Arrays.copyOf(r, n);
4478	>	}
4479	>	r[i++] = (T)e;
4480	>	}
4481	>	if (a == r && i < n) {
4482	>	r[i] = null; // null-terminate
4483	>	return r;
4484	>	}
4485	>	return (i == n) ? r : Arrays.copyOf(r, i);
4486	>	}
4487	>
4488	>	/**
4489	>	* Returns a string representation of this collection.
4490	>	* The string representation consists of the string representations
4491	>	* of the collection's elements in the order they are returned by
4492	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4493	>	* Adjacent elements are separated by the characters {@code ", "}
4494	>	* (comma and space).  Elements are converted to strings as by
4495	>	* {@link String#valueOf(Object)}.
4496	>	*
4497	>	* @return a string representation of this collection
4498	>	*/
4499	>	public final String toString() {
4500	>	StringBuilder sb = new StringBuilder();
4501	>	sb.append('[');
4502	>	Iterator<E> it = iterator();
4503	>	if (it.hasNext()) {
4504	>	for (;;) {
4505	>	Object e = it.next();
4506	>	sb.append(e == this ? "(this Collection)" : e);
4507	>	if (!it.hasNext())
4508	>	break;
4509	>	sb.append(',').append(' ');
4510	>	}
4511	>	}
4512	>	return sb.append(']').toString();
4513	>	}
4514	>
4515	>	public final boolean containsAll(Collection<?> c) {
4516	>	if (c != this) {
4517	>	for (Object e : c) {
4518	>	if (e == null || !contains(e))
4519	>	return false;
4520	>	}
4521	>	}
4522	>	return true;
4523	>	}
4524	>
4525	>	public final boolean removeAll(Collection<?> c) {
4526	>	if (c == null) throw new NullPointerException();
4527	>	boolean modified = false;
4528	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4529	>	if (c.contains(it.next())) {
4530	>	it.remove();
4531	>	modified = true;
4532	>	}
4533	>	}
4534	>	return modified;
4535	>	}
4536	>
4537	>	public final boolean retainAll(Collection<?> c) {
4538	>	if (c == null) throw new NullPointerException();
4539	>	boolean modified = false;
4540	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4541	>	if (!c.contains(it.next())) {
4542	>	it.remove();
4543	>	modified = true;
4544	>	}
4545	>	}
4546	>	return modified;
4547	>	}
4548	>
4549	>	}
4550	>
4551	>	/**
4552	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4553	>	* which additions may optionally be enabled by mapping to a
4554	>	* common value.  This class cannot be directly instantiated.
4555	>	* See {@link #keySet() keySet()},
4556	>	* {@link #keySet(Object) keySet(V)},
4557	>	* {@link #newKeySet() newKeySet()},
4558	>	* {@link #newKeySet(int) newKeySet(int)}.
4559		*
4560	<	* @return  an enumeration of the values in this table.
853	<	* @see     java.util.Enumeration
854	<	* @see     #keys()
855	<	* @see     #values()
856	<	* @see     Map
4560	>	* @since 1.8
4561		*/
4562	<	public Enumeration<V> elements() {
4563	<	return new ValueIterator();
4562	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4563	>	implements Set<K>, java.io.Serializable {
4564	>	private static final long serialVersionUID = 7249069246763182397L;
4565	>	private final V value;
4566	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4567	>	super(map);
4568	>	this.value = value;
4569	>	}
4570	>
4571	>	/**
4572	>	* Returns the default mapped value for additions,
4573	>	* or {@code null} if additions are not supported.
4574	>	*
4575	>	* @return the default mapped value for additions, or {@code null}
4576	>	* if not supported
4577	>	*/
4578	>	public V getMappedValue() { return value; }
4579	>
4580	>	/**
4581	>	* {@inheritDoc}
4582	>	* @throws NullPointerException if the specified key is null
4583	>	*/
4584	>	public boolean contains(Object o) { return map.containsKey(o); }
4585	>
4586	>	/**
4587	>	* Removes the key from this map view, by removing the key (and its
4588	>	* corresponding value) from the backing map.  This method does
4589	>	* nothing if the key is not in the map.
4590	>	*
4591	>	* @param  o the key to be removed from the backing map
4592	>	* @return {@code true} if the backing map contained the specified key
4593	>	* @throws NullPointerException if the specified key is null
4594	>	*/
4595	>	public boolean remove(Object o) { return map.remove(o) != null; }
4596	>
4597	>	/**
4598	>	* @return an iterator over the keys of the backing map
4599	>	*/
4600	>	public Iterator<K> iterator() {
4601	>	Node<K,V>[] t;
4602	>	ConcurrentHashMap<K,V> m = map;
4603	>	int f = (t = m.table) == null ? 0 : t.length;
4604	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4605	>	}
4606	>
4607	>	/**
4608	>	* Adds the specified key to this set view by mapping the key to
4609	>	* the default mapped value in the backing map, if defined.
4610	>	*
4611	>	* @param e key to be added
4612	>	* @return {@code true} if this set changed as a result of the call
4613	>	* @throws NullPointerException if the specified key is null
4614	>	* @throws UnsupportedOperationException if no default mapped value
4615	>	* for additions was provided
4616	>	*/
4617	>	public boolean add(K e) {
4618	>	V v;
4619	>	if ((v = value) == null)
4620	>	throw new UnsupportedOperationException();
4621	>	return map.putVal(e, v, true) == null;
4622	>	}
4623	>
4624	>	/**
4625	>	* Adds all of the elements in the specified collection to this set,
4626	>	* as if by calling {@link #add} on each one.
4627	>	*
4628	>	* @param c the elements to be inserted into this set
4629	>	* @return {@code true} if this set changed as a result of the call
4630	>	* @throws NullPointerException if the collection or any of its
4631	>	* elements are {@code null}
4632	>	* @throws UnsupportedOperationException if no default mapped value
4633	>	* for additions was provided
4634	>	*/
4635	>	public boolean addAll(Collection<? extends K> c) {
4636	>	boolean added = false;
4637	>	V v;
4638	>	if ((v = value) == null)
4639	>	throw new UnsupportedOperationException();
4640	>	for (K e : c) {
4641	>	if (map.putVal(e, v, true) == null)
4642	>	added = true;
4643	>	}
4644	>	return added;
4645	>	}
4646	>
4647	>	public int hashCode() {
4648	>	int h = 0;
4649	>	for (K e : this)
4650	>	h += e.hashCode();
4651	>	return h;
4652	>	}
4653	>
4654	>	public boolean equals(Object o) {
4655	>	Set<?> c;
4656	>	return ((o instanceof Set) &&
4657	>	((c = (Set<?>)o) == this ||
4658	>	(containsAll(c) && c.containsAll(this))));
4659	>	}
4660	>
4661	>	public Spliterator<K> spliterator() {
4662	>	Node<K,V>[] t;
4663	>	ConcurrentHashMap<K,V> m = map;
4664	>	long n = m.sumCount();
4665	>	int f = (t = m.table) == null ? 0 : t.length;
4666	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4667	>	}
4668	>
4669	>	public void forEach(Consumer<? super K> action) {
4670	>	if (action == null) throw new NullPointerException();
4671	>	Node<K,V>[] t;
4672	>	if ((t = map.table) != null) {
4673	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4674	>	for (Node<K,V> p; (p = it.advance()) != null; )
4675	>	action.accept(p.key);
4676	>	}
4677	>	}
4678	>	}
4679	>
4680	>	/**
4681	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4682	>	* values, in which additions are disabled. This class cannot be
4683	>	* directly instantiated. See {@link #values()}.
4684	>	*/
4685	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4686	>	implements Collection<V>, java.io.Serializable {
4687	>	private static final long serialVersionUID = 2249069246763182397L;
4688	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4689	>	public final boolean contains(Object o) {
4690	>	return map.containsValue(o);
4691	>	}
4692	>
4693	>	public final boolean remove(Object o) {
4694	>	if (o != null) {
4695	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4696	>	if (o.equals(it.next())) {
4697	>	it.remove();
4698	>	return true;
4699	>	}
4700	>	}
4701	>	}
4702	>	return false;
4703	>	}
4704	>
4705	>	public final Iterator<V> iterator() {
4706	>	ConcurrentHashMap<K,V> m = map;
4707	>	Node<K,V>[] t;
4708	>	int f = (t = m.table) == null ? 0 : t.length;
4709	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4710	>	}
4711	>
4712	>	public final boolean add(V e) {
4713	>	throw new UnsupportedOperationException();
4714	>	}
4715	>	public final boolean addAll(Collection<? extends V> c) {
4716	>	throw new UnsupportedOperationException();
4717	>	}
4718	>
4719	>	public boolean removeIf(Predicate<? super V> filter) {
4720	>	return map.removeValueIf(filter);
4721	>	}
4722	>
4723	>	public Spliterator<V> spliterator() {
4724	>	Node<K,V>[] t;
4725	>	ConcurrentHashMap<K,V> m = map;
4726	>	long n = m.sumCount();
4727	>	int f = (t = m.table) == null ? 0 : t.length;
4728	>	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4729	>	}
4730	>
4731	>	public void forEach(Consumer<? super V> action) {
4732	>	if (action == null) throw new NullPointerException();
4733	>	Node<K,V>[] t;
4734	>	if ((t = map.table) != null) {
4735	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4736	>	for (Node<K,V> p; (p = it.advance()) != null; )
4737	>	action.accept(p.val);
4738	>	}
4739	>	}
4740		}
4741
4742	<	/* ---------------- Iterator Support -------------- */
4742	>	/**
4743	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4744	>	* entries.  This class cannot be directly instantiated. See
4745	>	* {@link #entrySet()}.
4746	>	*/
4747	>	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4748	>	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4749	>	private static final long serialVersionUID = 2249069246763182397L;
4750	>	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4751	>
4752	>	public boolean contains(Object o) {
4753	>	Object k, v, r; Map.Entry<?,?> e;
4754	>	return ((o instanceof Map.Entry) &&
4755	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4756	>	(r = map.get(k)) != null &&
4757	>	(v = e.getValue()) != null &&
4758	>	(v == r || v.equals(r)));
4759	>	}
4760
4761	<	private abstract class HashIterator {
4762	<	private int nextSegmentIndex;
4763	<	private int nextTableIndex;
4764	<	private HashEntry[] currentTable;
4765	<	private HashEntry<K, V> nextEntry;
4766	<	private HashEntry<K, V> lastReturned;
4761	>	public boolean remove(Object o) {
4762	>	Object k, v; Map.Entry<?,?> e;
4763	>	return ((o instanceof Map.Entry) &&
4764	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4765	>	(v = e.getValue()) != null &&
4766	>	map.remove(k, v));
4767	>	}
4768
4769	<	private HashIterator() {
4770	<	nextSegmentIndex = segments.length - 1;
4771	<	nextTableIndex = -1;
4772	<	advance();
4769	>	/**
4770	>	* @return an iterator over the entries of the backing map
4771	>	*/
4772	>	public Iterator<Map.Entry<K,V>> iterator() {
4773	>	ConcurrentHashMap<K,V> m = map;
4774	>	Node<K,V>[] t;
4775	>	int f = (t = m.table) == null ? 0 : t.length;
4776	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4777	>	}
4778	>
4779	>	public boolean add(Entry<K,V> e) {
4780	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4781		}
4782
4783	<	public boolean hasMoreElements() { return hasNext(); }
4783	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4784	>	boolean added = false;
4785	>	for (Entry<K,V> e : c) {
4786	>	if (add(e))
4787	>	added = true;
4788	>	}
4789	>	return added;
4790	>	}
4791
4792	<	private void advance() {
4793	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
4794	<	return;
4792	>	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4793	>	return map.removeEntryIf(filter);
4794	>	}
4795
4796	<	while (nextTableIndex >= 0) {
4797	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
4798	<	return;
4796	>	public final int hashCode() {
4797	>	int h = 0;
4798	>	Node<K,V>[] t;
4799	>	if ((t = map.table) != null) {
4800	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4801	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4802	>	h += p.hashCode();
4803	>	}
4804		}
4805	+	return h;
4806	+	}
4807
4808	<	while (nextSegmentIndex >= 0) {
4809	<	Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
4810	<	if (seg.count != 0) {
4811	<	currentTable = seg.table;
4812	<	for (int j = currentTable.length - 1; j >= 0; --j) {
4813	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
4814	<	nextTableIndex = j - 1;
4815	<	return;
4816	<	}
4808	>	public final boolean equals(Object o) {
4809	>	Set<?> c;
4810	>	return ((o instanceof Set) &&
4811	>	((c = (Set<?>)o) == this ||
4812	>	(containsAll(c) && c.containsAll(this))));
4813	>	}
4814	>
4815	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4816	>	Node<K,V>[] t;
4817	>	ConcurrentHashMap<K,V> m = map;
4818	>	long n = m.sumCount();
4819	>	int f = (t = m.table) == null ? 0 : t.length;
4820	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4821	>	}
4822	>
4823	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4824	>	if (action == null) throw new NullPointerException();
4825	>	Node<K,V>[] t;
4826	>	if ((t = map.table) != null) {
4827	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4828	>	for (Node<K,V> p; (p = it.advance()) != null; )
4829	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4830	>	}
4831	>	}
4832	>
4833	>	}
4834	>
4835	>	// -------------------------------------------------------
4836	>
4837	>	/**
4838	>	* Base class for bulk tasks. Repeats some fields and code from
4839	>	* class Traverser, because we need to subclass CountedCompleter.
4840	>	*/
4841	>	@SuppressWarnings("serial")
4842	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4843	>	Node<K,V>[] tab;        // same as Traverser
4844	>	Node<K,V> next;
4845	>	TableStack<K,V> stack, spare;
4846	>	int index;
4847	>	int baseIndex;
4848	>	int baseLimit;
4849	>	final int baseSize;
4850	>	int batch;              // split control
4851	>
4852	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4853	>	super(par);
4854	>	this.batch = b;
4855	>	this.index = this.baseIndex = i;
4856	>	if ((this.tab = t) == null)
4857	>	this.baseSize = this.baseLimit = 0;
4858	>	else if (par == null)
4859	>	this.baseSize = this.baseLimit = t.length;
4860	>	else {
4861	>	this.baseLimit = f;
4862	>	this.baseSize = par.baseSize;
4863	>	}
4864	>	}
4865	>
4866	>	/**
4867	>	* Same as Traverser version.
4868	>	*/
4869	>	final Node<K,V> advance() {
4870	>	Node<K,V> e;
4871	>	if ((e = next) != null)
4872	>	e = e.next;
4873	>	for (;;) {
4874	>	Node<K,V>[] t; int i, n;
4875	>	if (e != null)
4876	>	return next = e;
4877	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4878	>	(n = t.length) <= (i = index) || i < 0)
4879	>	return next = null;
4880	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4881	>	if (e instanceof ForwardingNode) {
4882	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4883	>	e = null;
4884	>	pushState(t, i, n);
4885	>	continue;
4886		}
4887	+	else if (e instanceof TreeBin)
4888	+	e = ((TreeBin<K,V>)e).first;
4889	+	else
4890	+	e = null;
4891		}
4892	+	if (stack != null)
4893	+	recoverState(n);
4894	+	else if ((index = i + baseSize) >= n)
4895	+	index = ++baseIndex;
4896		}
4897		}
4898
4899	<	public boolean hasNext() { return nextEntry != null; }
4899	>	private void pushState(Node<K,V>[] t, int i, int n) {
4900	>	TableStack<K,V> s = spare;
4901	>	if (s != null)
4902	>	spare = s.next;
4903	>	else
4904	>	s = new TableStack<K,V>();
4905	>	s.tab = t;
4906	>	s.length = n;
4907	>	s.index = i;
4908	>	s.next = stack;
4909	>	stack = s;
4910	>	}
4911
4912	<	HashEntry<K,V> nextEntry() {
4913	<	if (nextEntry == null)
4914	<	throw new NoSuchElementException();
4915	<	lastReturned = nextEntry;
4916	<	advance();
4917	<	return lastReturned;
4912	>	private void recoverState(int n) {
4913	>	TableStack<K,V> s; int len;
4914	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4915	>	n = len;
4916	>	index = s.index;
4917	>	tab = s.tab;
4918	>	s.tab = null;
4919	>	TableStack<K,V> next = s.next;
4920	>	s.next = spare; // save for reuse
4921	>	stack = next;
4922	>	spare = s;
4923	>	}
4924	>	if (s == null && (index += baseSize) >= n)
4925	>	index = ++baseIndex;
4926		}
4927	+	}
4928
4929	<	public void remove() {
4930	<	if (lastReturned == null)
4931	<	throw new IllegalStateException();
4932	<	ConcurrentHashMap.this.remove(lastReturned.key);
4933	<	lastReturned = null;
4929	>	/*
4930	>	* Task classes. Coded in a regular but ugly format/style to
4931	>	* simplify checks that each variant differs in the right way from
4932	>	* others. The null screenings exist because compilers cannot tell
4933	>	* that we've already null-checked task arguments, so we force
4934	>	* simplest hoisted bypass to help avoid convoluted traps.
4935	>	*/
4936	>	@SuppressWarnings("serial")
4937	>	static final class ForEachKeyTask<K,V>
4938	>	extends BulkTask<K,V,Void> {
4939	>	final Consumer<? super K> action;
4940	>	ForEachKeyTask
4941	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4942	>	Consumer<? super K> action) {
4943	>	super(p, b, i, f, t);
4944	>	this.action = action;
4945	>	}
4946	>	public final void compute() {
4947	>	final Consumer<? super K> action;
4948	>	if ((action = this.action) != null) {
4949	>	for (int i = baseIndex, f, h; batch > 0 &&
4950	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4951	>	addToPendingCount(1);
4952	>	new ForEachKeyTask<K,V>
4953	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4954	>	action).fork();
4955	>	}
4956	>	for (Node<K,V> p; (p = advance()) != null;)
4957	>	action.accept(p.key);
4958	>	propagateCompletion();
4959	>	}
4960		}
4961		}
4962
4963	<	private class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
4964	<	public K next() { return super.nextEntry().key; }
4965	<	public K nextElement() { return super.nextEntry().key; }
4963	>	@SuppressWarnings("serial")
4964	>	static final class ForEachValueTask<K,V>
4965	>	extends BulkTask<K,V,Void> {
4966	>	final Consumer<? super V> action;
4967	>	ForEachValueTask
4968	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4969	>	Consumer<? super V> action) {
4970	>	super(p, b, i, f, t);
4971	>	this.action = action;
4972	>	}
4973	>	public final void compute() {
4974	>	final Consumer<? super V> action;
4975	>	if ((action = this.action) != null) {
4976	>	for (int i = baseIndex, f, h; batch > 0 &&
4977	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4978	>	addToPendingCount(1);
4979	>	new ForEachValueTask<K,V>
4980	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4981	>	action).fork();
4982	>	}
4983	>	for (Node<K,V> p; (p = advance()) != null;)
4984	>	action.accept(p.val);
4985	>	propagateCompletion();
4986	>	}
4987	>	}
4988		}
4989
4990	<	private class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
4991	<	public V next() { return super.nextEntry().value; }
4992	<	public V nextElement() { return super.nextEntry().value; }
4990	>	@SuppressWarnings("serial")
4991	>	static final class ForEachEntryTask<K,V>
4992	>	extends BulkTask<K,V,Void> {
4993	>	final Consumer<? super Entry<K,V>> action;
4994	>	ForEachEntryTask
4995	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4996	>	Consumer<? super Entry<K,V>> action) {
4997	>	super(p, b, i, f, t);
4998	>	this.action = action;
4999	>	}
5000	>	public final void compute() {
5001	>	final Consumer<? super Entry<K,V>> action;
5002	>	if ((action = this.action) != null) {
5003	>	for (int i = baseIndex, f, h; batch > 0 &&
5004	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5005	>	addToPendingCount(1);
5006	>	new ForEachEntryTask<K,V>
5007	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5008	>	action).fork();
5009	>	}
5010	>	for (Node<K,V> p; (p = advance()) != null; )
5011	>	action.accept(p);
5012	>	propagateCompletion();
5013	>	}
5014	>	}
5015		}
5016
5017	<	private class EntryIterator extends HashIterator implements Iterator<Entry<K,V>> {
5018	<	public Map.Entry<K,V> next() { return super.nextEntry(); }
5017	>	@SuppressWarnings("serial")
5018	>	static final class ForEachMappingTask<K,V>
5019	>	extends BulkTask<K,V,Void> {
5020	>	final BiConsumer<? super K, ? super V> action;
5021	>	ForEachMappingTask
5022	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5023	>	BiConsumer<? super K,? super V> action) {
5024	>	super(p, b, i, f, t);
5025	>	this.action = action;
5026	>	}
5027	>	public final void compute() {
5028	>	final BiConsumer<? super K, ? super V> action;
5029	>	if ((action = this.action) != null) {
5030	>	for (int i = baseIndex, f, h; batch > 0 &&
5031	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5032	>	addToPendingCount(1);
5033	>	new ForEachMappingTask<K,V>
5034	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5035	>	action).fork();
5036	>	}
5037	>	for (Node<K,V> p; (p = advance()) != null; )
5038	>	action.accept(p.key, p.val);
5039	>	propagateCompletion();
5040	>	}
5041	>	}
5042		}
5043
5044	<	private class KeySet extends AbstractSet<K> {
5045	<	public Iterator<K> iterator() {
5046	<	return new KeyIterator();
5044	>	@SuppressWarnings("serial")
5045	>	static final class ForEachTransformedKeyTask<K,V,U>
5046	>	extends BulkTask<K,V,Void> {
5047	>	final Function<? super K, ? extends U> transformer;
5048	>	final Consumer<? super U> action;
5049	>	ForEachTransformedKeyTask
5050	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5051	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5052	>	super(p, b, i, f, t);
5053	>	this.transformer = transformer; this.action = action;
5054		}
5055	<	public int size() {
5056	<	return ConcurrentHashMap.this.size();
5055	>	public final void compute() {
5056	>	final Function<? super K, ? extends U> transformer;
5057	>	final Consumer<? super U> action;
5058	>	if ((transformer = this.transformer) != null &&
5059	>	(action = this.action) != null) {
5060	>	for (int i = baseIndex, f, h; batch > 0 &&
5061	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5062	>	addToPendingCount(1);
5063	>	new ForEachTransformedKeyTask<K,V,U>
5064	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5065	>	transformer, action).fork();
5066	>	}
5067	>	for (Node<K,V> p; (p = advance()) != null; ) {
5068	>	U u;
5069	>	if ((u = transformer.apply(p.key)) != null)
5070	>	action.accept(u);
5071	>	}
5072	>	propagateCompletion();
5073	>	}
5074		}
5075	<	public boolean contains(Object o) {
5076	<	return ConcurrentHashMap.this.containsKey(o);
5075	>	}
5076	>
5077	>	@SuppressWarnings("serial")
5078	>	static final class ForEachTransformedValueTask<K,V,U>
5079	>	extends BulkTask<K,V,Void> {
5080	>	final Function<? super V, ? extends U> transformer;
5081	>	final Consumer<? super U> action;
5082	>	ForEachTransformedValueTask
5083	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5084	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5085	>	super(p, b, i, f, t);
5086	>	this.transformer = transformer; this.action = action;
5087		}
5088	<	public boolean remove(Object o) {
5089	<	return ConcurrentHashMap.this.remove(o) != null;
5088	>	public final void compute() {
5089	>	final Function<? super V, ? extends U> transformer;
5090	>	final Consumer<? super U> action;
5091	>	if ((transformer = this.transformer) != null &&
5092	>	(action = this.action) != null) {
5093	>	for (int i = baseIndex, f, h; batch > 0 &&
5094	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5095	>	addToPendingCount(1);
5096	>	new ForEachTransformedValueTask<K,V,U>
5097	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5098	>	transformer, action).fork();
5099	>	}
5100	>	for (Node<K,V> p; (p = advance()) != null; ) {
5101	>	U u;
5102	>	if ((u = transformer.apply(p.val)) != null)
5103	>	action.accept(u);
5104	>	}
5105	>	propagateCompletion();
5106	>	}
5107		}
5108	<	public void clear() {
5109	<	ConcurrentHashMap.this.clear();
5108	>	}
5109	>
5110	>	@SuppressWarnings("serial")
5111	>	static final class ForEachTransformedEntryTask<K,V,U>
5112	>	extends BulkTask<K,V,Void> {
5113	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5114	>	final Consumer<? super U> action;
5115	>	ForEachTransformedEntryTask
5116	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5117	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5118	>	super(p, b, i, f, t);
5119	>	this.transformer = transformer; this.action = action;
5120	>	}
5121	>	public final void compute() {
5122	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5123	>	final Consumer<? super U> action;
5124	>	if ((transformer = this.transformer) != null &&
5125	>	(action = this.action) != null) {
5126	>	for (int i = baseIndex, f, h; batch > 0 &&
5127	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5128	>	addToPendingCount(1);
5129	>	new ForEachTransformedEntryTask<K,V,U>
5130	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5131	>	transformer, action).fork();
5132	>	}
5133	>	for (Node<K,V> p; (p = advance()) != null; ) {
5134	>	U u;
5135	>	if ((u = transformer.apply(p)) != null)
5136	>	action.accept(u);
5137	>	}
5138	>	propagateCompletion();
5139	>	}
5140		}
5141		}
5142
5143	<	private class Values extends AbstractCollection<V> {
5144	<	public Iterator<V> iterator() {
5145	<	return new ValueIterator();
5143	>	@SuppressWarnings("serial")
5144	>	static final class ForEachTransformedMappingTask<K,V,U>
5145	>	extends BulkTask<K,V,Void> {
5146	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5147	>	final Consumer<? super U> action;
5148	>	ForEachTransformedMappingTask
5149	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5150	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5151	>	Consumer<? super U> action) {
5152	>	super(p, b, i, f, t);
5153	>	this.transformer = transformer; this.action = action;
5154		}
5155	<	public int size() {
5156	<	return ConcurrentHashMap.this.size();
5155	>	public final void compute() {
5156	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5157	>	final Consumer<? super U> action;
5158	>	if ((transformer = this.transformer) != null &&
5159	>	(action = this.action) != null) {
5160	>	for (int i = baseIndex, f, h; batch > 0 &&
5161	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5162	>	addToPendingCount(1);
5163	>	new ForEachTransformedMappingTask<K,V,U>
5164	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5165	>	transformer, action).fork();
5166	>	}
5167	>	for (Node<K,V> p; (p = advance()) != null; ) {
5168	>	U u;
5169	>	if ((u = transformer.apply(p.key, p.val)) != null)
5170	>	action.accept(u);
5171	>	}
5172	>	propagateCompletion();
5173	>	}
5174		}
5175	<	public boolean contains(Object o) {
5176	<	return ConcurrentHashMap.this.containsValue(o);
5175	>	}
5176	>
5177	>	@SuppressWarnings("serial")
5178	>	static final class SearchKeysTask<K,V,U>
5179	>	extends BulkTask<K,V,U> {
5180	>	final Function<? super K, ? extends U> searchFunction;
5181	>	final AtomicReference<U> result;
5182	>	SearchKeysTask
5183	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5184	>	Function<? super K, ? extends U> searchFunction,
5185	>	AtomicReference<U> result) {
5186	>	super(p, b, i, f, t);
5187	>	this.searchFunction = searchFunction; this.result = result;
5188		}
5189	<	public void clear() {
5190	<	ConcurrentHashMap.this.clear();
5189	>	public final U getRawResult() { return result.get(); }
5190	>	public final void compute() {
5191	>	final Function<? super K, ? extends U> searchFunction;
5192	>	final AtomicReference<U> result;
5193	>	if ((searchFunction = this.searchFunction) != null &&
5194	>	(result = this.result) != null) {
5195	>	for (int i = baseIndex, f, h; batch > 0 &&
5196	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5197	>	if (result.get() != null)
5198	>	return;
5199	>	addToPendingCount(1);
5200	>	new SearchKeysTask<K,V,U>
5201	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5202	>	searchFunction, result).fork();
5203	>	}
5204	>	while (result.get() == null) {
5205	>	U u;
5206	>	Node<K,V> p;
5207	>	if ((p = advance()) == null) {
5208	>	propagateCompletion();
5209	>	break;
5210	>	}
5211	>	if ((u = searchFunction.apply(p.key)) != null) {
5212	>	if (result.compareAndSet(null, u))
5213	>	quietlyCompleteRoot();
5214	>	break;
5215	>	}
5216	>	}
5217	>	}
5218		}
5219		}
5220
5221	<	private class EntrySet extends AbstractSet<Map.Entry<K,V>> {
5222	<	public Iterator<Map.Entry<K,V>> iterator() {
5223	<	return new EntryIterator();
5221	>	@SuppressWarnings("serial")
5222	>	static final class SearchValuesTask<K,V,U>
5223	>	extends BulkTask<K,V,U> {
5224	>	final Function<? super V, ? extends U> searchFunction;
5225	>	final AtomicReference<U> result;
5226	>	SearchValuesTask
5227	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5228	>	Function<? super V, ? extends U> searchFunction,
5229	>	AtomicReference<U> result) {
5230	>	super(p, b, i, f, t);
5231	>	this.searchFunction = searchFunction; this.result = result;
5232		}
5233	<	public boolean contains(Object o) {
5234	<	if (!(o instanceof Map.Entry))
5235	<	return false;
5236	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
5237	<	V v = ConcurrentHashMap.this.get(e.getKey());
5238	<	return v != null && v.equals(e.getValue());
5233	>	public final U getRawResult() { return result.get(); }
5234	>	public final void compute() {
5235	>	final Function<? super V, ? extends U> searchFunction;
5236	>	final AtomicReference<U> result;
5237	>	if ((searchFunction = this.searchFunction) != null &&
5238	>	(result = this.result) != null) {
5239	>	for (int i = baseIndex, f, h; batch > 0 &&
5240	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5241	>	if (result.get() != null)
5242	>	return;
5243	>	addToPendingCount(1);
5244	>	new SearchValuesTask<K,V,U>
5245	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5246	>	searchFunction, result).fork();
5247	>	}
5248	>	while (result.get() == null) {
5249	>	U u;
5250	>	Node<K,V> p;
5251	>	if ((p = advance()) == null) {
5252	>	propagateCompletion();
5253	>	break;
5254	>	}
5255	>	if ((u = searchFunction.apply(p.val)) != null) {
5256	>	if (result.compareAndSet(null, u))
5257	>	quietlyCompleteRoot();
5258	>	break;
5259	>	}
5260	>	}
5261	>	}
5262		}
5263	<	public boolean remove(Object o) {
5264	<	if (!(o instanceof Map.Entry))
5265	<	return false;
5266	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
5267	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
5263	>	}
5264	>
5265	>	@SuppressWarnings("serial")
5266	>	static final class SearchEntriesTask<K,V,U>
5267	>	extends BulkTask<K,V,U> {
5268	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5269	>	final AtomicReference<U> result;
5270	>	SearchEntriesTask
5271	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5272	>	Function<Entry<K,V>, ? extends U> searchFunction,
5273	>	AtomicReference<U> result) {
5274	>	super(p, b, i, f, t);
5275	>	this.searchFunction = searchFunction; this.result = result;
5276	>	}
5277	>	public final U getRawResult() { return result.get(); }
5278	>	public final void compute() {
5279	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5280	>	final AtomicReference<U> result;
5281	>	if ((searchFunction = this.searchFunction) != null &&
5282	>	(result = this.result) != null) {
5283	>	for (int i = baseIndex, f, h; batch > 0 &&
5284	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5285	>	if (result.get() != null)
5286	>	return;
5287	>	addToPendingCount(1);
5288	>	new SearchEntriesTask<K,V,U>
5289	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5290	>	searchFunction, result).fork();
5291	>	}
5292	>	while (result.get() == null) {
5293	>	U u;
5294	>	Node<K,V> p;
5295	>	if ((p = advance()) == null) {
5296	>	propagateCompletion();
5297	>	break;
5298	>	}
5299	>	if ((u = searchFunction.apply(p)) != null) {
5300	>	if (result.compareAndSet(null, u))
5301	>	quietlyCompleteRoot();
5302	>	return;
5303	>	}
5304	>	}
5305	>	}
5306		}
5307	<	public int size() {
5308	<	return ConcurrentHashMap.this.size();
5307	>	}
5308	>
5309	>	@SuppressWarnings("serial")
5310	>	static final class SearchMappingsTask<K,V,U>
5311	>	extends BulkTask<K,V,U> {
5312	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5313	>	final AtomicReference<U> result;
5314	>	SearchMappingsTask
5315	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5316	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5317	>	AtomicReference<U> result) {
5318	>	super(p, b, i, f, t);
5319	>	this.searchFunction = searchFunction; this.result = result;
5320		}
5321	<	public void clear() {
5322	<	ConcurrentHashMap.this.clear();
5321	>	public final U getRawResult() { return result.get(); }
5322	>	public final void compute() {
5323	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5324	>	final AtomicReference<U> result;
5325	>	if ((searchFunction = this.searchFunction) != null &&
5326	>	(result = this.result) != null) {
5327	>	for (int i = baseIndex, f, h; batch > 0 &&
5328	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5329	>	if (result.get() != null)
5330	>	return;
5331	>	addToPendingCount(1);
5332	>	new SearchMappingsTask<K,V,U>
5333	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5334	>	searchFunction, result).fork();
5335	>	}
5336	>	while (result.get() == null) {
5337	>	U u;
5338	>	Node<K,V> p;
5339	>	if ((p = advance()) == null) {
5340	>	propagateCompletion();
5341	>	break;
5342	>	}
5343	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5344	>	if (result.compareAndSet(null, u))
5345	>	quietlyCompleteRoot();
5346	>	break;
5347	>	}
5348	>	}
5349	>	}
5350		}
5351		}
5352
5353	<	/* ---------------- Serialization Support -------------- */
5353	>	@SuppressWarnings("serial")
5354	>	static final class ReduceKeysTask<K,V>
5355	>	extends BulkTask<K,V,K> {
5356	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5357	>	K result;
5358	>	ReduceKeysTask<K,V> rights, nextRight;
5359	>	ReduceKeysTask
5360	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5361	>	ReduceKeysTask<K,V> nextRight,
5362	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5363	>	super(p, b, i, f, t); this.nextRight = nextRight;
5364	>	this.reducer = reducer;
5365	>	}
5366	>	public final K getRawResult() { return result; }
5367	>	public final void compute() {
5368	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5369	>	if ((reducer = this.reducer) != null) {
5370	>	for (int i = baseIndex, f, h; batch > 0 &&
5371	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5372	>	addToPendingCount(1);
5373	>	(rights = new ReduceKeysTask<K,V>
5374	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5375	>	rights, reducer)).fork();
5376	>	}
5377	>	K r = null;
5378	>	for (Node<K,V> p; (p = advance()) != null; ) {
5379	>	K u = p.key;
5380	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5381	>	}
5382	>	result = r;
5383	>	CountedCompleter<?> c;
5384	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5385	>	@SuppressWarnings("unchecked")
5386	>	ReduceKeysTask<K,V>
5387	>	t = (ReduceKeysTask<K,V>)c,
5388	>	s = t.rights;
5389	>	while (s != null) {
5390	>	K tr, sr;
5391	>	if ((sr = s.result) != null)
5392	>	t.result = (((tr = t.result) == null) ? sr :
5393	>	reducer.apply(tr, sr));
5394	>	s = t.rights = s.nextRight;
5395	>	}
5396	>	}
5397	>	}
5398	>	}
5399	>	}
5400
5401	<	/**
5402	<	* Save the state of the <tt>ConcurrentHashMap</tt>
5403	<	* instance to a stream (i.e.,
5404	<	* serialize it).
5405	<	* @param s the stream
5406	<	* @serialData
5407	<	* the key (Object) and value (Object)
5408	<	* for each key-value mapping, followed by a null pair.
5409	<	* The key-value mappings are emitted in no particular order.
5410	<	*/
5411	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
5412	<	s.defaultWriteObject();
5401	>	@SuppressWarnings("serial")
5402	>	static final class ReduceValuesTask<K,V>
5403	>	extends BulkTask<K,V,V> {
5404	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5405	>	V result;
5406	>	ReduceValuesTask<K,V> rights, nextRight;
5407	>	ReduceValuesTask
5408	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5409	>	ReduceValuesTask<K,V> nextRight,
5410	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5411	>	super(p, b, i, f, t); this.nextRight = nextRight;
5412	>	this.reducer = reducer;
5413	>	}
5414	>	public final V getRawResult() { return result; }
5415	>	public final void compute() {
5416	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5417	>	if ((reducer = this.reducer) != null) {
5418	>	for (int i = baseIndex, f, h; batch > 0 &&
5419	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5420	>	addToPendingCount(1);
5421	>	(rights = new ReduceValuesTask<K,V>
5422	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5423	>	rights, reducer)).fork();
5424	>	}
5425	>	V r = null;
5426	>	for (Node<K,V> p; (p = advance()) != null; ) {
5427	>	V v = p.val;
5428	>	r = (r == null) ? v : reducer.apply(r, v);
5429	>	}
5430	>	result = r;
5431	>	CountedCompleter<?> c;
5432	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5433	>	@SuppressWarnings("unchecked")
5434	>	ReduceValuesTask<K,V>
5435	>	t = (ReduceValuesTask<K,V>)c,
5436	>	s = t.rights;
5437	>	while (s != null) {
5438	>	V tr, sr;
5439	>	if ((sr = s.result) != null)
5440	>	t.result = (((tr = t.result) == null) ? sr :
5441	>	reducer.apply(tr, sr));
5442	>	s = t.rights = s.nextRight;
5443	>	}
5444	>	}
5445	>	}
5446	>	}
5447	>	}
5448
5449	<	for (int k = 0; k < segments.length; ++k) {
5450	<	Segment<K,V> seg = (Segment<K,V>)segments[k];
5451	<	seg.lock();
5452	<	try {
5453	<	HashEntry[] tab = seg.table;
5454	<	for (int i = 0; i < tab.length; ++i) {
5455	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
5456	<	s.writeObject(e.key);
5457	<	s.writeObject(e.value);
5449	>	@SuppressWarnings("serial")
5450	>	static final class ReduceEntriesTask<K,V>
5451	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5452	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5453	>	Map.Entry<K,V> result;
5454	>	ReduceEntriesTask<K,V> rights, nextRight;
5455	>	ReduceEntriesTask
5456	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5457	>	ReduceEntriesTask<K,V> nextRight,
5458	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5459	>	super(p, b, i, f, t); this.nextRight = nextRight;
5460	>	this.reducer = reducer;
5461	>	}
5462	>	public final Map.Entry<K,V> getRawResult() { return result; }
5463	>	public final void compute() {
5464	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5465	>	if ((reducer = this.reducer) != null) {
5466	>	for (int i = baseIndex, f, h; batch > 0 &&
5467	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5468	>	addToPendingCount(1);
5469	>	(rights = new ReduceEntriesTask<K,V>
5470	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5471	>	rights, reducer)).fork();
5472	>	}
5473	>	Map.Entry<K,V> r = null;
5474	>	for (Node<K,V> p; (p = advance()) != null; )
5475	>	r = (r == null) ? p : reducer.apply(r, p);
5476	>	result = r;
5477	>	CountedCompleter<?> c;
5478	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5479	>	@SuppressWarnings("unchecked")
5480	>	ReduceEntriesTask<K,V>
5481	>	t = (ReduceEntriesTask<K,V>)c,
5482	>	s = t.rights;
5483	>	while (s != null) {
5484	>	Map.Entry<K,V> tr, sr;
5485	>	if ((sr = s.result) != null)
5486	>	t.result = (((tr = t.result) == null) ? sr :
5487	>	reducer.apply(tr, sr));
5488	>	s = t.rights = s.nextRight;
5489	>	}
5490	>	}
5491	>	}
5492	>	}
5493	>	}
5494	>
5495	>	@SuppressWarnings("serial")
5496	>	static final class MapReduceKeysTask<K,V,U>
5497	>	extends BulkTask<K,V,U> {
5498	>	final Function<? super K, ? extends U> transformer;
5499	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5500	>	U result;
5501	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5502	>	MapReduceKeysTask
5503	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5504	>	MapReduceKeysTask<K,V,U> nextRight,
5505	>	Function<? super K, ? extends U> transformer,
5506	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5507	>	super(p, b, i, f, t); this.nextRight = nextRight;
5508	>	this.transformer = transformer;
5509	>	this.reducer = reducer;
5510	>	}
5511	>	public final U getRawResult() { return result; }
5512	>	public final void compute() {
5513	>	final Function<? super K, ? extends U> transformer;
5514	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5515	>	if ((transformer = this.transformer) != null &&
5516	>	(reducer = this.reducer) != null) {
5517	>	for (int i = baseIndex, f, h; batch > 0 &&
5518	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5519	>	addToPendingCount(1);
5520	>	(rights = new MapReduceKeysTask<K,V,U>
5521	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5522	>	rights, transformer, reducer)).fork();
5523	>	}
5524	>	U r = null;
5525	>	for (Node<K,V> p; (p = advance()) != null; ) {
5526	>	U u;
5527	>	if ((u = transformer.apply(p.key)) != null)
5528	>	r = (r == null) ? u : reducer.apply(r, u);
5529	>	}
5530	>	result = r;
5531	>	CountedCompleter<?> c;
5532	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5533	>	@SuppressWarnings("unchecked")
5534	>	MapReduceKeysTask<K,V,U>
5535	>	t = (MapReduceKeysTask<K,V,U>)c,
5536	>	s = t.rights;
5537	>	while (s != null) {
5538	>	U tr, sr;
5539	>	if ((sr = s.result) != null)
5540	>	t.result = (((tr = t.result) == null) ? sr :
5541	>	reducer.apply(tr, sr));
5542	>	s = t.rights = s.nextRight;
5543		}
5544		}
5545		}
5546	<	finally {
5547	<	seg.unlock();
5546	>	}
5547	>	}
5548	>
5549	>	@SuppressWarnings("serial")
5550	>	static final class MapReduceValuesTask<K,V,U>
5551	>	extends BulkTask<K,V,U> {
5552	>	final Function<? super V, ? extends U> transformer;
5553	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5554	>	U result;
5555	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5556	>	MapReduceValuesTask
5557	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5558	>	MapReduceValuesTask<K,V,U> nextRight,
5559	>	Function<? super V, ? extends U> transformer,
5560	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5561	>	super(p, b, i, f, t); this.nextRight = nextRight;
5562	>	this.transformer = transformer;
5563	>	this.reducer = reducer;
5564	>	}
5565	>	public final U getRawResult() { return result; }
5566	>	public final void compute() {
5567	>	final Function<? super V, ? extends U> transformer;
5568	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5569	>	if ((transformer = this.transformer) != null &&
5570	>	(reducer = this.reducer) != null) {
5571	>	for (int i = baseIndex, f, h; batch > 0 &&
5572	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5573	>	addToPendingCount(1);
5574	>	(rights = new MapReduceValuesTask<K,V,U>
5575	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5576	>	rights, transformer, reducer)).fork();
5577	>	}
5578	>	U r = null;
5579	>	for (Node<K,V> p; (p = advance()) != null; ) {
5580	>	U u;
5581	>	if ((u = transformer.apply(p.val)) != null)
5582	>	r = (r == null) ? u : reducer.apply(r, u);
5583	>	}
5584	>	result = r;
5585	>	CountedCompleter<?> c;
5586	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5587	>	@SuppressWarnings("unchecked")
5588	>	MapReduceValuesTask<K,V,U>
5589	>	t = (MapReduceValuesTask<K,V,U>)c,
5590	>	s = t.rights;
5591	>	while (s != null) {
5592	>	U tr, sr;
5593	>	if ((sr = s.result) != null)
5594	>	t.result = (((tr = t.result) == null) ? sr :
5595	>	reducer.apply(tr, sr));
5596	>	s = t.rights = s.nextRight;
5597	>	}
5598	>	}
5599		}
5600		}
1023	–	s.writeObject(null);
1024	–	s.writeObject(null);
5601		}
5602
5603	<	/**
5604	<	* Reconstitute the <tt>ConcurrentHashMap</tt>
5605	<	* instance from a stream (i.e.,
5606	<	* deserialize it).
5607	<	* @param s the stream
5608	<	*/
5609	<	private void readObject(java.io.ObjectInputStream s)
5610	<	throws IOException, ClassNotFoundException  {
5611	<	s.defaultReadObject();
5603	>	@SuppressWarnings("serial")
5604	>	static final class MapReduceEntriesTask<K,V,U>
5605	>	extends BulkTask<K,V,U> {
5606	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5607	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5608	>	U result;
5609	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5610	>	MapReduceEntriesTask
5611	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5612	>	MapReduceEntriesTask<K,V,U> nextRight,
5613	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5614	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5615	>	super(p, b, i, f, t); this.nextRight = nextRight;
5616	>	this.transformer = transformer;
5617	>	this.reducer = reducer;
5618	>	}
5619	>	public final U getRawResult() { return result; }
5620	>	public final void compute() {
5621	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5622	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5623	>	if ((transformer = this.transformer) != null &&
5624	>	(reducer = this.reducer) != null) {
5625	>	for (int i = baseIndex, f, h; batch > 0 &&
5626	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5627	>	addToPendingCount(1);
5628	>	(rights = new MapReduceEntriesTask<K,V,U>
5629	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5630	>	rights, transformer, reducer)).fork();
5631	>	}
5632	>	U r = null;
5633	>	for (Node<K,V> p; (p = advance()) != null; ) {
5634	>	U u;
5635	>	if ((u = transformer.apply(p)) != null)
5636	>	r = (r == null) ? u : reducer.apply(r, u);
5637	>	}
5638	>	result = r;
5639	>	CountedCompleter<?> c;
5640	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5641	>	@SuppressWarnings("unchecked")
5642	>	MapReduceEntriesTask<K,V,U>
5643	>	t = (MapReduceEntriesTask<K,V,U>)c,
5644	>	s = t.rights;
5645	>	while (s != null) {
5646	>	U tr, sr;
5647	>	if ((sr = s.result) != null)
5648	>	t.result = (((tr = t.result) == null) ? sr :
5649	>	reducer.apply(tr, sr));
5650	>	s = t.rights = s.nextRight;
5651	>	}
5652	>	}
5653	>	}
5654	>	}
5655	>	}
5656
5657	<	// Initialize each segment to be minimally sized, and let grow.
5658	<	for (int i = 0; i < segments.length; ++i) {
5659	<	segments[i].setTable(new HashEntry[1]);
5657	>	@SuppressWarnings("serial")
5658	>	static final class MapReduceMappingsTask<K,V,U>
5659	>	extends BulkTask<K,V,U> {
5660	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5661	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5662	>	U result;
5663	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5664	>	MapReduceMappingsTask
5665	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5666	>	MapReduceMappingsTask<K,V,U> nextRight,
5667	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5668	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5669	>	super(p, b, i, f, t); this.nextRight = nextRight;
5670	>	this.transformer = transformer;
5671	>	this.reducer = reducer;
5672		}
5673	+	public final U getRawResult() { return result; }
5674	+	public final void compute() {
5675	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5676	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5677	+	if ((transformer = this.transformer) != null &&
5678	+	(reducer = this.reducer) != null) {
5679	+	for (int i = baseIndex, f, h; batch > 0 &&
5680	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5681	+	addToPendingCount(1);
5682	+	(rights = new MapReduceMappingsTask<K,V,U>
5683	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5684	+	rights, transformer, reducer)).fork();
5685	+	}
5686	+	U r = null;
5687	+	for (Node<K,V> p; (p = advance()) != null; ) {
5688	+	U u;
5689	+	if ((u = transformer.apply(p.key, p.val)) != null)
5690	+	r = (r == null) ? u : reducer.apply(r, u);
5691	+	}
5692	+	result = r;
5693	+	CountedCompleter<?> c;
5694	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5695	+	@SuppressWarnings("unchecked")
5696	+	MapReduceMappingsTask<K,V,U>
5697	+	t = (MapReduceMappingsTask<K,V,U>)c,
5698	+	s = t.rights;
5699	+	while (s != null) {
5700	+	U tr, sr;
5701	+	if ((sr = s.result) != null)
5702	+	t.result = (((tr = t.result) == null) ? sr :
5703	+	reducer.apply(tr, sr));
5704	+	s = t.rights = s.nextRight;
5705	+	}
5706	+	}
5707	+	}
5708	+	}
5709	+	}
5710
5711	<	// Read the keys and values, and put the mappings in the table
5712	<	for (;;) {
5713	<	K key = (K) s.readObject();
5714	<	V value = (V) s.readObject();
5715	<	if (key == null)
5716	<	break;
5717	<	put(key, value);
5711	>	@SuppressWarnings("serial")
5712	>	static final class MapReduceKeysToDoubleTask<K,V>
5713	>	extends BulkTask<K,V,Double> {
5714	>	final ToDoubleFunction<? super K> transformer;
5715	>	final DoubleBinaryOperator reducer;
5716	>	final double basis;
5717	>	double result;
5718	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5719	>	MapReduceKeysToDoubleTask
5720	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5721	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5722	>	ToDoubleFunction<? super K> transformer,
5723	>	double basis,
5724	>	DoubleBinaryOperator reducer) {
5725	>	super(p, b, i, f, t); this.nextRight = nextRight;
5726	>	this.transformer = transformer;
5727	>	this.basis = basis; this.reducer = reducer;
5728	>	}
5729	>	public final Double getRawResult() { return result; }
5730	>	public final void compute() {
5731	>	final ToDoubleFunction<? super K> transformer;
5732	>	final DoubleBinaryOperator reducer;
5733	>	if ((transformer = this.transformer) != null &&
5734	>	(reducer = this.reducer) != null) {
5735	>	double r = this.basis;
5736	>	for (int i = baseIndex, f, h; batch > 0 &&
5737	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5738	>	addToPendingCount(1);
5739	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5740	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5741	>	rights, transformer, r, reducer)).fork();
5742	>	}
5743	>	for (Node<K,V> p; (p = advance()) != null; )
5744	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5745	>	result = r;
5746	>	CountedCompleter<?> c;
5747	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5748	>	@SuppressWarnings("unchecked")
5749	>	MapReduceKeysToDoubleTask<K,V>
5750	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5751	>	s = t.rights;
5752	>	while (s != null) {
5753	>	t.result = reducer.applyAsDouble(t.result, s.result);
5754	>	s = t.rights = s.nextRight;
5755	>	}
5756	>	}
5757	>	}
5758		}
5759		}
1051	–	}
5760
5761	+	@SuppressWarnings("serial")
5762	+	static final class MapReduceValuesToDoubleTask<K,V>
5763	+	extends BulkTask<K,V,Double> {
5764	+	final ToDoubleFunction<? super V> transformer;
5765	+	final DoubleBinaryOperator reducer;
5766	+	final double basis;
5767	+	double result;
5768	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5769	+	MapReduceValuesToDoubleTask
5770	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5771	+	MapReduceValuesToDoubleTask<K,V> nextRight,
5772	+	ToDoubleFunction<? super V> transformer,
5773	+	double basis,
5774	+	DoubleBinaryOperator reducer) {
5775	+	super(p, b, i, f, t); this.nextRight = nextRight;
5776	+	this.transformer = transformer;
5777	+	this.basis = basis; this.reducer = reducer;
5778	+	}
5779	+	public final Double getRawResult() { return result; }
5780	+	public final void compute() {
5781	+	final ToDoubleFunction<? super V> transformer;
5782	+	final DoubleBinaryOperator reducer;
5783	+	if ((transformer = this.transformer) != null &&
5784	+	(reducer = this.reducer) != null) {
5785	+	double r = this.basis;
5786	+	for (int i = baseIndex, f, h; batch > 0 &&
5787	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5788	+	addToPendingCount(1);
5789	+	(rights = new MapReduceValuesToDoubleTask<K,V>
5790	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5791	+	rights, transformer, r, reducer)).fork();
5792	+	}
5793	+	for (Node<K,V> p; (p = advance()) != null; )
5794	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5795	+	result = r;
5796	+	CountedCompleter<?> c;
5797	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5798	+	@SuppressWarnings("unchecked")
5799	+	MapReduceValuesToDoubleTask<K,V>
5800	+	t = (MapReduceValuesToDoubleTask<K,V>)c,
5801	+	s = t.rights;
5802	+	while (s != null) {
5803	+	t.result = reducer.applyAsDouble(t.result, s.result);
5804	+	s = t.rights = s.nextRight;
5805	+	}
5806	+	}
5807	+	}
5808	+	}
5809	+	}
5810	+
5811	+	@SuppressWarnings("serial")
5812	+	static final class MapReduceEntriesToDoubleTask<K,V>
5813	+	extends BulkTask<K,V,Double> {
5814	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5815	+	final DoubleBinaryOperator reducer;
5816	+	final double basis;
5817	+	double result;
5818	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5819	+	MapReduceEntriesToDoubleTask
5820	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5821	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
5822	+	ToDoubleFunction<Map.Entry<K,V>> transformer,
5823	+	double basis,
5824	+	DoubleBinaryOperator reducer) {
5825	+	super(p, b, i, f, t); this.nextRight = nextRight;
5826	+	this.transformer = transformer;
5827	+	this.basis = basis; this.reducer = reducer;
5828	+	}
5829	+	public final Double getRawResult() { return result; }
5830	+	public final void compute() {
5831	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5832	+	final DoubleBinaryOperator reducer;
5833	+	if ((transformer = this.transformer) != null &&
5834	+	(reducer = this.reducer) != null) {
5835	+	double r = this.basis;
5836	+	for (int i = baseIndex, f, h; batch > 0 &&
5837	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5838	+	addToPendingCount(1);
5839	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
5840	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5841	+	rights, transformer, r, reducer)).fork();
5842	+	}
5843	+	for (Node<K,V> p; (p = advance()) != null; )
5844	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5845	+	result = r;
5846	+	CountedCompleter<?> c;
5847	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5848	+	@SuppressWarnings("unchecked")
5849	+	MapReduceEntriesToDoubleTask<K,V>
5850	+	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5851	+	s = t.rights;
5852	+	while (s != null) {
5853	+	t.result = reducer.applyAsDouble(t.result, s.result);
5854	+	s = t.rights = s.nextRight;
5855	+	}
5856	+	}
5857	+	}
5858	+	}
5859	+	}
5860	+
5861	+	@SuppressWarnings("serial")
5862	+	static final class MapReduceMappingsToDoubleTask<K,V>
5863	+	extends BulkTask<K,V,Double> {
5864	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5865	+	final DoubleBinaryOperator reducer;
5866	+	final double basis;
5867	+	double result;
5868	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5869	+	MapReduceMappingsToDoubleTask
5870	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5871	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
5872	+	ToDoubleBiFunction<? super K, ? super V> transformer,
5873	+	double basis,
5874	+	DoubleBinaryOperator reducer) {
5875	+	super(p, b, i, f, t); this.nextRight = nextRight;
5876	+	this.transformer = transformer;
5877	+	this.basis = basis; this.reducer = reducer;
5878	+	}
5879	+	public final Double getRawResult() { return result; }
5880	+	public final void compute() {
5881	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5882	+	final DoubleBinaryOperator reducer;
5883	+	if ((transformer = this.transformer) != null &&
5884	+	(reducer = this.reducer) != null) {
5885	+	double r = this.basis;
5886	+	for (int i = baseIndex, f, h; batch > 0 &&
5887	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5888	+	addToPendingCount(1);
5889	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
5890	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5891	+	rights, transformer, r, reducer)).fork();
5892	+	}
5893	+	for (Node<K,V> p; (p = advance()) != null; )
5894	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5895	+	result = r;
5896	+	CountedCompleter<?> c;
5897	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5898	+	@SuppressWarnings("unchecked")
5899	+	MapReduceMappingsToDoubleTask<K,V>
5900	+	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5901	+	s = t.rights;
5902	+	while (s != null) {
5903	+	t.result = reducer.applyAsDouble(t.result, s.result);
5904	+	s = t.rights = s.nextRight;
5905	+	}
5906	+	}
5907	+	}
5908	+	}
5909	+	}
5910	+
5911	+	@SuppressWarnings("serial")
5912	+	static final class MapReduceKeysToLongTask<K,V>
5913	+	extends BulkTask<K,V,Long> {
5914	+	final ToLongFunction<? super K> transformer;
5915	+	final LongBinaryOperator reducer;
5916	+	final long basis;
5917	+	long result;
5918	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
5919	+	MapReduceKeysToLongTask
5920	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5921	+	MapReduceKeysToLongTask<K,V> nextRight,
5922	+	ToLongFunction<? super K> transformer,
5923	+	long basis,
5924	+	LongBinaryOperator reducer) {
5925	+	super(p, b, i, f, t); this.nextRight = nextRight;
5926	+	this.transformer = transformer;
5927	+	this.basis = basis; this.reducer = reducer;
5928	+	}
5929	+	public final Long getRawResult() { return result; }
5930	+	public final void compute() {
5931	+	final ToLongFunction<? super K> transformer;
5932	+	final LongBinaryOperator reducer;
5933	+	if ((transformer = this.transformer) != null &&
5934	+	(reducer = this.reducer) != null) {
5935	+	long r = this.basis;
5936	+	for (int i = baseIndex, f, h; batch > 0 &&
5937	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5938	+	addToPendingCount(1);
5939	+	(rights = new MapReduceKeysToLongTask<K,V>
5940	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5941	+	rights, transformer, r, reducer)).fork();
5942	+	}
5943	+	for (Node<K,V> p; (p = advance()) != null; )
5944	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5945	+	result = r;
5946	+	CountedCompleter<?> c;
5947	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5948	+	@SuppressWarnings("unchecked")
5949	+	MapReduceKeysToLongTask<K,V>
5950	+	t = (MapReduceKeysToLongTask<K,V>)c,
5951	+	s = t.rights;
5952	+	while (s != null) {
5953	+	t.result = reducer.applyAsLong(t.result, s.result);
5954	+	s = t.rights = s.nextRight;
5955	+	}
5956	+	}
5957	+	}
5958	+	}
5959	+	}
5960	+
5961	+	@SuppressWarnings("serial")
5962	+	static final class MapReduceValuesToLongTask<K,V>
5963	+	extends BulkTask<K,V,Long> {
5964	+	final ToLongFunction<? super V> transformer;
5965	+	final LongBinaryOperator reducer;
5966	+	final long basis;
5967	+	long result;
5968	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
5969	+	MapReduceValuesToLongTask
5970	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5971	+	MapReduceValuesToLongTask<K,V> nextRight,
5972	+	ToLongFunction<? super V> transformer,
5973	+	long basis,
5974	+	LongBinaryOperator reducer) {
5975	+	super(p, b, i, f, t); this.nextRight = nextRight;
5976	+	this.transformer = transformer;
5977	+	this.basis = basis; this.reducer = reducer;
5978	+	}
5979	+	public final Long getRawResult() { return result; }
5980	+	public final void compute() {
5981	+	final ToLongFunction<? super V> transformer;
5982	+	final LongBinaryOperator reducer;
5983	+	if ((transformer = this.transformer) != null &&
5984	+	(reducer = this.reducer) != null) {
5985	+	long r = this.basis;
5986	+	for (int i = baseIndex, f, h; batch > 0 &&
5987	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5988	+	addToPendingCount(1);
5989	+	(rights = new MapReduceValuesToLongTask<K,V>
5990	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5991	+	rights, transformer, r, reducer)).fork();
5992	+	}
5993	+	for (Node<K,V> p; (p = advance()) != null; )
5994	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5995	+	result = r;
5996	+	CountedCompleter<?> c;
5997	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5998	+	@SuppressWarnings("unchecked")
5999	+	MapReduceValuesToLongTask<K,V>
6000	+	t = (MapReduceValuesToLongTask<K,V>)c,
6001	+	s = t.rights;
6002	+	while (s != null) {
6003	+	t.result = reducer.applyAsLong(t.result, s.result);
6004	+	s = t.rights = s.nextRight;
6005	+	}
6006	+	}
6007	+	}
6008	+	}
6009	+	}
6010	+
6011	+	@SuppressWarnings("serial")
6012	+	static final class MapReduceEntriesToLongTask<K,V>
6013	+	extends BulkTask<K,V,Long> {
6014	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6015	+	final LongBinaryOperator reducer;
6016	+	final long basis;
6017	+	long result;
6018	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6019	+	MapReduceEntriesToLongTask
6020	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6021	+	MapReduceEntriesToLongTask<K,V> nextRight,
6022	+	ToLongFunction<Map.Entry<K,V>> transformer,
6023	+	long basis,
6024	+	LongBinaryOperator reducer) {
6025	+	super(p, b, i, f, t); this.nextRight = nextRight;
6026	+	this.transformer = transformer;
6027	+	this.basis = basis; this.reducer = reducer;
6028	+	}
6029	+	public final Long getRawResult() { return result; }
6030	+	public final void compute() {
6031	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6032	+	final LongBinaryOperator reducer;
6033	+	if ((transformer = this.transformer) != null &&
6034	+	(reducer = this.reducer) != null) {
6035	+	long r = this.basis;
6036	+	for (int i = baseIndex, f, h; batch > 0 &&
6037	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6038	+	addToPendingCount(1);
6039	+	(rights = new MapReduceEntriesToLongTask<K,V>
6040	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6041	+	rights, transformer, r, reducer)).fork();
6042	+	}
6043	+	for (Node<K,V> p; (p = advance()) != null; )
6044	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6045	+	result = r;
6046	+	CountedCompleter<?> c;
6047	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6048	+	@SuppressWarnings("unchecked")
6049	+	MapReduceEntriesToLongTask<K,V>
6050	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6051	+	s = t.rights;
6052	+	while (s != null) {
6053	+	t.result = reducer.applyAsLong(t.result, s.result);
6054	+	s = t.rights = s.nextRight;
6055	+	}
6056	+	}
6057	+	}
6058	+	}
6059	+	}
6060	+
6061	+	@SuppressWarnings("serial")
6062	+	static final class MapReduceMappingsToLongTask<K,V>
6063	+	extends BulkTask<K,V,Long> {
6064	+	final ToLongBiFunction<? super K, ? super V> transformer;
6065	+	final LongBinaryOperator reducer;
6066	+	final long basis;
6067	+	long result;
6068	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6069	+	MapReduceMappingsToLongTask
6070	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6071	+	MapReduceMappingsToLongTask<K,V> nextRight,
6072	+	ToLongBiFunction<? super K, ? super V> transformer,
6073	+	long basis,
6074	+	LongBinaryOperator reducer) {
6075	+	super(p, b, i, f, t); this.nextRight = nextRight;
6076	+	this.transformer = transformer;
6077	+	this.basis = basis; this.reducer = reducer;
6078	+	}
6079	+	public final Long getRawResult() { return result; }
6080	+	public final void compute() {
6081	+	final ToLongBiFunction<? super K, ? super V> transformer;
6082	+	final LongBinaryOperator reducer;
6083	+	if ((transformer = this.transformer) != null &&
6084	+	(reducer = this.reducer) != null) {
6085	+	long r = this.basis;
6086	+	for (int i = baseIndex, f, h; batch > 0 &&
6087	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6088	+	addToPendingCount(1);
6089	+	(rights = new MapReduceMappingsToLongTask<K,V>
6090	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6091	+	rights, transformer, r, reducer)).fork();
6092	+	}
6093	+	for (Node<K,V> p; (p = advance()) != null; )
6094	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6095	+	result = r;
6096	+	CountedCompleter<?> c;
6097	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6098	+	@SuppressWarnings("unchecked")
6099	+	MapReduceMappingsToLongTask<K,V>
6100	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6101	+	s = t.rights;
6102	+	while (s != null) {
6103	+	t.result = reducer.applyAsLong(t.result, s.result);
6104	+	s = t.rights = s.nextRight;
6105	+	}
6106	+	}
6107	+	}
6108	+	}
6109	+	}
6110	+
6111	+	@SuppressWarnings("serial")
6112	+	static final class MapReduceKeysToIntTask<K,V>
6113	+	extends BulkTask<K,V,Integer> {
6114	+	final ToIntFunction<? super K> transformer;
6115	+	final IntBinaryOperator reducer;
6116	+	final int basis;
6117	+	int result;
6118	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6119	+	MapReduceKeysToIntTask
6120	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6121	+	MapReduceKeysToIntTask<K,V> nextRight,
6122	+	ToIntFunction<? super K> transformer,
6123	+	int basis,
6124	+	IntBinaryOperator reducer) {
6125	+	super(p, b, i, f, t); this.nextRight = nextRight;
6126	+	this.transformer = transformer;
6127	+	this.basis = basis; this.reducer = reducer;
6128	+	}
6129	+	public final Integer getRawResult() { return result; }
6130	+	public final void compute() {
6131	+	final ToIntFunction<? super K> transformer;
6132	+	final IntBinaryOperator reducer;
6133	+	if ((transformer = this.transformer) != null &&
6134	+	(reducer = this.reducer) != null) {
6135	+	int r = this.basis;
6136	+	for (int i = baseIndex, f, h; batch > 0 &&
6137	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6138	+	addToPendingCount(1);
6139	+	(rights = new MapReduceKeysToIntTask<K,V>
6140	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6141	+	rights, transformer, r, reducer)).fork();
6142	+	}
6143	+	for (Node<K,V> p; (p = advance()) != null; )
6144	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6145	+	result = r;
6146	+	CountedCompleter<?> c;
6147	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6148	+	@SuppressWarnings("unchecked")
6149	+	MapReduceKeysToIntTask<K,V>
6150	+	t = (MapReduceKeysToIntTask<K,V>)c,
6151	+	s = t.rights;
6152	+	while (s != null) {
6153	+	t.result = reducer.applyAsInt(t.result, s.result);
6154	+	s = t.rights = s.nextRight;
6155	+	}
6156	+	}
6157	+	}
6158	+	}
6159	+	}
6160	+
6161	+	@SuppressWarnings("serial")
6162	+	static final class MapReduceValuesToIntTask<K,V>
6163	+	extends BulkTask<K,V,Integer> {
6164	+	final ToIntFunction<? super V> transformer;
6165	+	final IntBinaryOperator reducer;
6166	+	final int basis;
6167	+	int result;
6168	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6169	+	MapReduceValuesToIntTask
6170	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6171	+	MapReduceValuesToIntTask<K,V> nextRight,
6172	+	ToIntFunction<? super V> transformer,
6173	+	int basis,
6174	+	IntBinaryOperator reducer) {
6175	+	super(p, b, i, f, t); this.nextRight = nextRight;
6176	+	this.transformer = transformer;
6177	+	this.basis = basis; this.reducer = reducer;
6178	+	}
6179	+	public final Integer getRawResult() { return result; }
6180	+	public final void compute() {
6181	+	final ToIntFunction<? super V> transformer;
6182	+	final IntBinaryOperator reducer;
6183	+	if ((transformer = this.transformer) != null &&
6184	+	(reducer = this.reducer) != null) {
6185	+	int r = this.basis;
6186	+	for (int i = baseIndex, f, h; batch > 0 &&
6187	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6188	+	addToPendingCount(1);
6189	+	(rights = new MapReduceValuesToIntTask<K,V>
6190	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6191	+	rights, transformer, r, reducer)).fork();
6192	+	}
6193	+	for (Node<K,V> p; (p = advance()) != null; )
6194	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6195	+	result = r;
6196	+	CountedCompleter<?> c;
6197	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6198	+	@SuppressWarnings("unchecked")
6199	+	MapReduceValuesToIntTask<K,V>
6200	+	t = (MapReduceValuesToIntTask<K,V>)c,
6201	+	s = t.rights;
6202	+	while (s != null) {
6203	+	t.result = reducer.applyAsInt(t.result, s.result);
6204	+	s = t.rights = s.nextRight;
6205	+	}
6206	+	}
6207	+	}
6208	+	}
6209	+	}
6210	+
6211	+	@SuppressWarnings("serial")
6212	+	static final class MapReduceEntriesToIntTask<K,V>
6213	+	extends BulkTask<K,V,Integer> {
6214	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6215	+	final IntBinaryOperator reducer;
6216	+	final int basis;
6217	+	int result;
6218	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6219	+	MapReduceEntriesToIntTask
6220	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6221	+	MapReduceEntriesToIntTask<K,V> nextRight,
6222	+	ToIntFunction<Map.Entry<K,V>> transformer,
6223	+	int basis,
6224	+	IntBinaryOperator reducer) {
6225	+	super(p, b, i, f, t); this.nextRight = nextRight;
6226	+	this.transformer = transformer;
6227	+	this.basis = basis; this.reducer = reducer;
6228	+	}
6229	+	public final Integer getRawResult() { return result; }
6230	+	public final void compute() {
6231	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6232	+	final IntBinaryOperator reducer;
6233	+	if ((transformer = this.transformer) != null &&
6234	+	(reducer = this.reducer) != null) {
6235	+	int r = this.basis;
6236	+	for (int i = baseIndex, f, h; batch > 0 &&
6237	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6238	+	addToPendingCount(1);
6239	+	(rights = new MapReduceEntriesToIntTask<K,V>
6240	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6241	+	rights, transformer, r, reducer)).fork();
6242	+	}
6243	+	for (Node<K,V> p; (p = advance()) != null; )
6244	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6245	+	result = r;
6246	+	CountedCompleter<?> c;
6247	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6248	+	@SuppressWarnings("unchecked")
6249	+	MapReduceEntriesToIntTask<K,V>
6250	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6251	+	s = t.rights;
6252	+	while (s != null) {
6253	+	t.result = reducer.applyAsInt(t.result, s.result);
6254	+	s = t.rights = s.nextRight;
6255	+	}
6256	+	}
6257	+	}
6258	+	}
6259	+	}
6260	+
6261	+	@SuppressWarnings("serial")
6262	+	static final class MapReduceMappingsToIntTask<K,V>
6263	+	extends BulkTask<K,V,Integer> {
6264	+	final ToIntBiFunction<? super K, ? super V> transformer;
6265	+	final IntBinaryOperator reducer;
6266	+	final int basis;
6267	+	int result;
6268	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6269	+	MapReduceMappingsToIntTask
6270	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6271	+	MapReduceMappingsToIntTask<K,V> nextRight,
6272	+	ToIntBiFunction<? super K, ? super V> transformer,
6273	+	int basis,
6274	+	IntBinaryOperator reducer) {
6275	+	super(p, b, i, f, t); this.nextRight = nextRight;
6276	+	this.transformer = transformer;
6277	+	this.basis = basis; this.reducer = reducer;
6278	+	}
6279	+	public final Integer getRawResult() { return result; }
6280	+	public final void compute() {
6281	+	final ToIntBiFunction<? super K, ? super V> transformer;
6282	+	final IntBinaryOperator reducer;
6283	+	if ((transformer = this.transformer) != null &&
6284	+	(reducer = this.reducer) != null) {
6285	+	int r = this.basis;
6286	+	for (int i = baseIndex, f, h; batch > 0 &&
6287	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6288	+	addToPendingCount(1);
6289	+	(rights = new MapReduceMappingsToIntTask<K,V>
6290	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6291	+	rights, transformer, r, reducer)).fork();
6292	+	}
6293	+	for (Node<K,V> p; (p = advance()) != null; )
6294	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6295	+	result = r;
6296	+	CountedCompleter<?> c;
6297	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6298	+	@SuppressWarnings("unchecked")
6299	+	MapReduceMappingsToIntTask<K,V>
6300	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6301	+	s = t.rights;
6302	+	while (s != null) {
6303	+	t.result = reducer.applyAsInt(t.result, s.result);
6304	+	s = t.rights = s.nextRight;
6305	+	}
6306	+	}
6307	+	}
6308	+	}
6309	+	}
6310	+
6311	+	// Unsafe mechanics
6312	+	private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
6313	+	private static final long SIZECTL;
6314	+	private static final long TRANSFERINDEX;
6315	+	private static final long BASECOUNT;
6316	+	private static final long CELLSBUSY;
6317	+	private static final long CELLVALUE;
6318	+	private static final int ABASE;
6319	+	private static final int ASHIFT;
6320	+
6321	+	static {
6322	+	try {
6323	+	SIZECTL = U.objectFieldOffset
6324	+	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6325	+	TRANSFERINDEX = U.objectFieldOffset
6326	+	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6327	+	BASECOUNT = U.objectFieldOffset
6328	+	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6329	+	CELLSBUSY = U.objectFieldOffset
6330	+	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6331	+
6332	+	CELLVALUE = U.objectFieldOffset
6333	+	(CounterCell.class.getDeclaredField("value"));
6334	+
6335	+	ABASE = U.arrayBaseOffset(Node[].class);
6336	+	int scale = U.arrayIndexScale(Node[].class);
6337	+	if ((scale & (scale - 1)) != 0)
6338	+	throw new Error("array index scale not a power of two");
6339	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6340	+	} catch (ReflectiveOperationException e) {
6341	+	throw new Error(e);
6342	+	}
6343	+
6344	+	// Reduce the risk of rare disastrous classloading in first call to
6345	+	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6346	+	Class<?> ensureLoaded = LockSupport.class;
6347	+	}
6348	+	}

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines