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

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