ViewVC Help

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

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

Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.33 by dl, Sat Dec 6 00:16:20 2003 UTC vs.
Revision 1.222 by dl, Mon Jun 17 18:53:58 2013 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3	<	* Expert Group and released to the public domain. Use, modify, and
4	<	* redistribute this code in any way without acknowledgement.
3	>	* Expert Group and released to the public domain, as explained at
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
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.Arrays;
14	>	import java.util.Collection;
15	>	import java.util.Comparator;
16	>	import java.util.ConcurrentModificationException;
17	>	import java.util.Enumeration;
18	>	import java.util.HashMap;
19	>	import java.util.Hashtable;
20	>	import java.util.Iterator;
21	>	import java.util.Map;
22	>	import java.util.NoSuchElementException;
23	>	import java.util.Set;
24	>	import java.util.Spliterator;
25	>	import java.util.concurrent.ConcurrentMap;
26	>	import java.util.concurrent.ForkJoinPool;
27	>	import java.util.concurrent.atomic.AtomicReference;
28	>	import java.util.concurrent.locks.LockSupport;
29	>	import java.util.concurrent.locks.ReentrantLock;
30	>	import java.util.function.BiConsumer;
31	>	import java.util.function.BiFunction;
32	>	import java.util.function.BinaryOperator;
33	>	import java.util.function.Consumer;
34	>	import java.util.function.DoubleBinaryOperator;
35	>	import java.util.function.Function;
36	>	import java.util.function.IntBinaryOperator;
37	>	import java.util.function.LongBinaryOperator;
38	>	import java.util.function.ToDoubleBiFunction;
39	>	import java.util.function.ToDoubleFunction;
40	>	import java.util.function.ToIntBiFunction;
41	>	import java.util.function.ToIntFunction;
42	>	import java.util.function.ToLongBiFunction;
43	>	import java.util.function.ToLongFunction;
44	>	import java.util.stream.Stream;
45
46		/**
47		* A hash table supporting full concurrency of retrievals and
48	<	* adjustable expected concurrency for updates. This class obeys the
48	>	* high expected concurrency for updates. This class obeys the
49		* same functional specification as {@link java.util.Hashtable}, and
50		* includes versions of methods corresponding to each method of
51	<	* <tt>Hashtable</tt>. However, even though all operations are
51	>	* {@code Hashtable}. However, even though all operations are
52		* thread-safe, retrieval operations do <em>not</em> entail locking,
53		* and there is <em>not</em> any support for locking the entire table
54		* in a way that prevents all access.  This class is fully
55	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
55	>	* interoperable with {@code Hashtable} in programs that rely on its
56		* thread safety but not on its synchronization details.
57		*
58	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
59	<	* block, so may overlap with update operations (including
60	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
61	<	* of the most recently <em>completed</em> update operations holding
62	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
63	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
64	<	* removal of only some entries.  Similarly, Iterators and
65	<	* Enumerations return elements reflecting the state of the hash table
66	<	* at some point at or since the creation of the iterator/enumeration.
67	<	* They do <em>not</em> throw
68	<	* {@link ConcurrentModificationException}.  However, iterators are
69	<	* designed to be used by only one thread at a time.
70	<	*
71	<	* <p> The allowed concurrency among update operations is guided by
72	<	* the optional <tt>concurrencyLevel</tt> constructor argument
73	<	* (default 16), which is used as a hint for internal sizing.  The
74	<	* table is internally partitioned to try to permit the indicated
75	<	* number of concurrent updates without contention. Because placement
76	<	* in hash tables is essentially random, the actual concurrency will
77	<	* vary.  Ideally, you should choose a value to accommodate as many
78	<	* threads as will ever concurrently modify the table. Using a
79	<	* significantly higher value than you need can waste space and time,
80	<	* and a significantly lower value can lead to thread contention. But
81	<	* overestimates and underestimates within an order of magnitude do
82	<	* not usually have much noticeable impact. A value of one is
83	<	* appropriate when it is known that only one thread will modify
84	<	* and all others will only read.
85	<	*
86	<	* <p>This class implements all of the <em>optional</em> methods
87	<	* of the {@link Map} and {@link Iterator} interfaces.
88	<	*
89	<	* <p> Like {@link java.util.Hashtable} but unlike {@link
90	<	* java.util.HashMap}, this class does NOT allow <tt>null</tt> to be
91	<	* used as a key or value.
58	>	* <p>Retrieval operations (including {@code get}) generally do not
59	>	* block, so may overlap with update operations (including {@code put}
60	>	* and {@code remove}). Retrievals reflect the results of the most
61	>	* recently <em>completed</em> update operations holding upon their
62	>	* onset. (More formally, an update operation for a given key bears a
63	>	* <em>happens-before</em> relation with any (non-null) retrieval for
64	>	* that key reporting the updated value.)  For aggregate operations
65	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
66	>	* reflect insertion or removal of only some entries.  Similarly,
67	>	* Iterators and Enumerations return elements reflecting the state of
68	>	* the hash table at some point at or since the creation of the
69	>	* iterator/enumeration.  They do <em>not</em> throw {@link
70	>	* ConcurrentModificationException}.  However, iterators are designed
71	>	* to be used by only one thread at a time.  Bear in mind that the
72	>	* results of aggregate status methods including {@code size}, {@code
73	>	* isEmpty}, and {@code containsValue} are typically useful only when
74	>	* a map is not undergoing concurrent updates in other threads.
75	>	* Otherwise the results of these methods reflect transient states
76	>	* that may be adequate for monitoring or estimation purposes, but not
77	>	* for program control.
78	>	*
79	>	* <p>The table is dynamically expanded when there are too many
80	>	* collisions (i.e., keys that have distinct hash codes but fall into
81	>	* the same slot modulo the table size), with the expected average
82	>	* effect of maintaining roughly two bins per mapping (corresponding
83	>	* to a 0.75 load factor threshold for resizing). There may be much
84	>	* variance around this average as mappings are added and removed, but
85	>	* overall, this maintains a commonly accepted time/space tradeoff for
86	>	* hash tables.  However, resizing this or any other kind of hash
87	>	* table may be a relatively slow operation. When possible, it is a
88	>	* good idea to provide a size estimate as an optional {@code
89	>	* initialCapacity} constructor argument. An additional optional
90	>	* {@code loadFactor} constructor argument provides a further means of
91	>	* customizing initial table capacity by specifying the table density
92	>	* to be used in calculating the amount of space to allocate for the
93	>	* given number of elements.  Also, for compatibility with previous
94	>	* versions of this class, constructors may optionally specify an
95	>	* expected {@code concurrencyLevel} as an additional hint for
96	>	* internal sizing.  Note that using many keys with exactly the same
97	>	* {@code hashCode()} is a sure way to slow down performance of any
98	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
99	>	* this class may use comparison order among keys to help break ties.
100	>	*
101	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
102	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
103	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
104	>	* mapped values are (perhaps transiently) not used or all take the
105	>	* same mapping value.
106	>	*
107	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
108	>	* form of histogram or multiset) by using {@link
109	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
110	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
111	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
112	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
113	>	*
114	>	* <p>This class and its views and iterators implement all of the
115	>	* <em>optional</em> methods of the {@link Map} and {@link Iterator}
116	>	* interfaces.
117	>	*
118	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
119	>	* does <em>not</em> allow {@code null} to be used as a key or value.
120	>	*
121	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
122	>	* operations that, unlike most {@link Stream} methods, are designed
123	>	* to be safely, and often sensibly, applied even with maps that are
124	>	* being concurrently updated by other threads; for example, when
125	>	* computing a snapshot summary of the values in a shared registry.
126	>	* There are three kinds of operation, each with four forms, accepting
127	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
128	>	* and/or return values. Because the elements of a ConcurrentHashMap
129	>	* are not ordered in any particular way, and may be processed in
130	>	* different orders in different parallel executions, the correctness
131	>	* of supplied functions should not depend on any ordering, or on any
132	>	* other objects or values that may transiently change while
133	>	* computation is in progress; and except for forEach actions, should
134	>	* ideally be side-effect-free. Bulk operations on {@link Map.Entry}
135	>	* objects do not support method {@code setValue}.
136	>	*
137	>	* <ul>
138	>	* <li> forEach: Perform a given action on each element.
139	>	* A variant form applies a given transformation on each element
140	>	* before performing the action.</li>
141	>	*
142	>	* <li> search: Return the first available non-null result of
143	>	* applying a given function on each element; skipping further
144	>	* search when a result is found.</li>
145	>	*
146	>	* <li> reduce: Accumulate each element.  The supplied reduction
147	>	* function cannot rely on ordering (more formally, it should be
148	>	* both associative and commutative).  There are five variants:
149	>	*
150	>	* <ul>
151	>	*
152	>	* <li> Plain reductions. (There is not a form of this method for
153	>	* (key, value) function arguments since there is no corresponding
154	>	* return type.)</li>
155	>	*
156	>	* <li> Mapped reductions that accumulate the results of a given
157	>	* function applied to each element.</li>
158	>	*
159	>	* <li> Reductions to scalar doubles, longs, and ints, using a
160	>	* given basis value.</li>
161	>	*
162	>	* </ul>
163	>	* </li>
164	>	* </ul>
165	>	*
166	>	* <p>These bulk operations accept a {@code parallelismThreshold}
167	>	* argument. Methods proceed sequentially if the current map size is
168	>	* estimated to be less than the given threshold. Using a value of
169	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
170	>	* of {@code 1} results in maximal parallelism by partitioning into
171	>	* enough subtasks to fully utilize the {@link
172	>	* ForkJoinPool#commonPool()} that is used for all parallel
173	>	* computations. Normally, you would initially choose one of these
174	>	* extreme values, and then measure performance of using in-between
175	>	* values that trade off overhead versus throughput.
176	>	*
177	>	* <p>The concurrency properties of bulk operations follow
178	>	* from those of ConcurrentHashMap: Any non-null result returned
179	>	* from {@code get(key)} and related access methods bears a
180	>	* happens-before relation with the associated insertion or
181	>	* update.  The result of any bulk operation reflects the
182	>	* composition of these per-element relations (but is not
183	>	* necessarily atomic with respect to the map as a whole unless it
184	>	* is somehow known to be quiescent).  Conversely, because keys
185	>	* and values in the map are never null, null serves as a reliable
186	>	* atomic indicator of the current lack of any result.  To
187	>	* maintain this property, null serves as an implicit basis for
188	>	* all non-scalar reduction operations. For the double, long, and
189	>	* int versions, the basis should be one that, when combined with
190	>	* any other value, returns that other value (more formally, it
191	>	* should be the identity element for the reduction). Most common
192	>	* reductions have these properties; for example, computing a sum
193	>	* with basis 0 or a minimum with basis MAX_VALUE.
194	>	*
195	>	* <p>Search and transformation functions provided as arguments
196	>	* should similarly return null to indicate the lack of any result
197	>	* (in which case it is not used). In the case of mapped
198	>	* reductions, this also enables transformations to serve as
199	>	* filters, returning null (or, in the case of primitive
200	>	* specializations, the identity basis) if the element should not
201	>	* be combined. You can create compound transformations and
202	>	* filterings by composing them yourself under this "null means
203	>	* there is nothing there now" rule before using them in search or
204	>	* reduce operations.
205	>	*
206	>	* <p>Methods accepting and/or returning Entry arguments maintain
207	>	* key-value associations. They may be useful for example when
208	>	* finding the key for the greatest value. Note that "plain" Entry
209	>	* arguments can be supplied using {@code new
210	>	* AbstractMap.SimpleEntry(k,v)}.
211	>	*
212	>	* <p>Bulk operations may complete abruptly, throwing an
213	>	* exception encountered in the application of a supplied
214	>	* function. Bear in mind when handling such exceptions that other
215	>	* concurrently executing functions could also have thrown
216	>	* exceptions, or would have done so if the first exception had
217	>	* not occurred.
218	>	*
219	>	* <p>Speedups for parallel compared to sequential forms are common
220	>	* but not guaranteed.  Parallel operations involving brief functions
221	>	* on small maps may execute more slowly than sequential forms if the
222	>	* underlying work to parallelize the computation is more expensive
223	>	* than the computation itself.  Similarly, parallelization may not
224	>	* lead to much actual parallelism if all processors are busy
225	>	* performing unrelated tasks.
226	>	*
227	>	* <p>All arguments to all task methods must be non-null.
228	>	*
229	>	* <p>This class is a member of the
230	>	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
231	>	* Java Collections Framework</a>.
232		*
233		* @since 1.5
234		* @author Doug Lea
235		* @param <K> the type of keys maintained by this map
236	<	* @param <V> the type of mapped values
236	>	* @param <V> the type of mapped values
237		*/
238	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
68	<	implements ConcurrentMap<K, V>, Cloneable, Serializable {
238	>	public class ConcurrentHashMap<K,V> implements ConcurrentMap<K,V>, Serializable {
239		private static final long serialVersionUID = 7249069246763182397L;
240
241		/*
242	<	* The basic strategy is to subdivide the table among Segments,
243	<	* each of which itself is a concurrently readable hash table.
242	>	* Overview:
243	>	*
244	>	* The primary design goal of this hash table is to maintain
245	>	* concurrent readability (typically method get(), but also
246	>	* iterators and related methods) while minimizing update
247	>	* contention. Secondary goals are to keep space consumption about
248	>	* the same or better than java.util.HashMap, and to support high
249	>	* initial insertion rates on an empty table by many threads.
250	>	*
251	>	* This map usually acts as a binned (bucketed) hash table.
252	>	* Each key-value mapping is held in a Node.  Most nodes are
253	>	* instances of the basic Node class with hash, key, value, and
254	>	* next fields. However, various subclasses exist: TreeNodes are
255	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
256	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
257	>	* of bins during resizing. ReservationNodes are used as
258	>	* placeholders while establishing values in computeIfAbsent and
259	>	* related methods.  The three type TreeBin, ForwardingNode, and
260	>	* ReservationNode do not hold normal user keys, values, or
261	>	* hashes, and are readily distinguishable during search etc
262	>	* because they have negative hash fields and null key and value
263	>	* fields. (These special nodes are either uncommon or transient,
264	>	* so the impact of carrying around some unused fields is
265	>	* insignficant.)
266	>	*
267	>	* The table is lazily initialized to a power-of-two size upon the
268	>	* first insertion.  Each bin in the table normally contains a
269	>	* list of Nodes (most often, the list has only zero or one Node).
270	>	* Table accesses require volatile/atomic reads, writes, and
271	>	* CASes.  Because there is no other way to arrange this without
272	>	* adding further indirections, we use intrinsics
273	>	* (sun.misc.Unsafe) operations.
274	>	*
275	>	* We use the top (sign) bit of Node hash fields for control
276	>	* purposes -- it is available anyway because of addressing
277	>	* constraints.  Nodes with negative hash fields are specially
278	>	* handled or ignored in map methods.
279	>	*
280	>	* Insertion (via put or its variants) of the first node in an
281	>	* empty bin is performed by just CASing it to the bin.  This is
282	>	* by far the most common case for put operations under most
283	>	* key/hash distributions.  Other update operations (insert,
284	>	* delete, and replace) require locks.  We do not want to waste
285	>	* the space required to associate a distinct lock object with
286	>	* each bin, so instead use the first node of a bin list itself as
287	>	* a lock. Locking support for these locks relies on builtin
288	>	* "synchronized" monitors.
289	>	*
290	>	* Using the first node of a list as a lock does not by itself
291	>	* suffice though: When a node is locked, any update must first
292	>	* validate that it is still the first node after locking it, and
293	>	* retry if not. Because new nodes are always appended to lists,
294	>	* once a node is first in a bin, it remains first until deleted
295	>	* or the bin becomes invalidated (upon resizing).
296	>	*
297	>	* The main disadvantage of per-bin locks is that other update
298	>	* operations on other nodes in a bin list protected by the same
299	>	* lock can stall, for example when user equals() or mapping
300	>	* functions take a long time.  However, statistically, under
301	>	* random hash codes, this is not a common problem.  Ideally, the
302	>	* frequency of nodes in bins follows a Poisson distribution
303	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
304	>	* parameter of about 0.5 on average, given the resizing threshold
305	>	* of 0.75, although with a large variance because of resizing
306	>	* granularity. Ignoring variance, the expected occurrences of
307	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
308	>	* first values are:
309	>	*
310	>	* 0:    0.60653066
311	>	* 1:    0.30326533
312	>	* 2:    0.07581633
313	>	* 3:    0.01263606
314	>	* 4:    0.00157952
315	>	* 5:    0.00015795
316	>	* 6:    0.00001316
317	>	* 7:    0.00000094
318	>	* 8:    0.00000006
319	>	* more: less than 1 in ten million
320	>	*
321	>	* Lock contention probability for two threads accessing distinct
322	>	* elements is roughly 1 / (8 * #elements) under random hashes.
323	>	*
324	>	* Actual hash code distributions encountered in practice
325	>	* sometimes deviate significantly from uniform randomness.  This
326	>	* includes the case when N > (1<<30), so some keys MUST collide.
327	>	* Similarly for dumb or hostile usages in which multiple keys are
328	>	* designed to have identical hash codes or ones that differs only
329	>	* in high bits. So we use a secondary strategy that applies when
330	>	* the number of nodes in a bin exceeds a threshold. These
331	>	* TreeBins use a balanced tree to hold nodes (a specialized form
332	>	* of red-black trees), bounding search time to O(log N).  Each
333	>	* search step in a TreeBin is at least twice as slow as in a
334	>	* regular list, but given that N cannot exceed (1<<64) (before
335	>	* running out of addresses) this bounds search steps, lock hold
336	>	* times, etc, to reasonable constants (roughly 100 nodes
337	>	* inspected per operation worst case) so long as keys are
338	>	* Comparable (which is very common -- String, Long, etc).
339	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
340	>	* traversal pointers as regular nodes, so can be traversed in
341	>	* iterators in the same way.
342	>	*
343	>	* The table is resized when occupancy exceeds a percentage
344	>	* threshold (nominally, 0.75, but see below).  Any thread
345	>	* noticing an overfull bin may assist in resizing after the
346	>	* initiating thread allocates and sets up the replacement
347	>	* array. However, rather than stalling, these other threads may
348	>	* proceed with insertions etc.  The use of TreeBins shields us
349	>	* from the worst case effects of overfilling while resizes are in
350	>	* progress.  Resizing proceeds by transferring bins, one by one,
351	>	* from the table to the next table. To enable concurrency, the
352	>	* next table must be (incrementally) prefilled with place-holders
353	>	* serving as reverse forwarders to the old table.  Because we are
354	>	* using power-of-two expansion, the elements from each bin must
355	>	* either stay at same index, or move with a power of two
356	>	* offset. We eliminate unnecessary node creation by catching
357	>	* cases where old nodes can be reused because their next fields
358	>	* won't change.  On average, only about one-sixth of them need
359	>	* cloning when a table doubles. The nodes they replace will be
360	>	* garbage collectable as soon as they are no longer referenced by
361	>	* any reader thread that may be in the midst of concurrently
362	>	* traversing table.  Upon transfer, the old table bin contains
363	>	* only a special forwarding node (with hash field "MOVED") that
364	>	* contains the next table as its key. On encountering a
365	>	* forwarding node, access and update operations restart, using
366	>	* the new table.
367	>	*
368	>	* Each bin transfer requires its bin lock, which can stall
369	>	* waiting for locks while resizing. However, because other
370	>	* threads can join in and help resize rather than contend for
371	>	* locks, average aggregate waits become shorter as resizing
372	>	* progresses.  The transfer operation must also ensure that all
373	>	* accessible bins in both the old and new table are usable by any
374	>	* traversal.  This is arranged by proceeding from the last bin
375	>	* (table.length - 1) up towards the first.  Upon seeing a
376	>	* forwarding node, traversals (see class Traverser) arrange to
377	>	* move to the new table without revisiting nodes.  However, to
378	>	* ensure that no intervening nodes are skipped, bin splitting can
379	>	* only begin after the associated reverse-forwarders are in
380	>	* place.
381	>	*
382	>	* The traversal scheme also applies to partial traversals of
383	>	* ranges of bins (via an alternate Traverser constructor)
384	>	* to support partitioned aggregate operations.  Also, read-only
385	>	* operations give up if ever forwarded to a null table, which
386	>	* provides support for shutdown-style clearing, which is also not
387	>	* currently implemented.
388	>	*
389	>	* Lazy table initialization minimizes footprint until first use,
390	>	* and also avoids resizings when the first operation is from a
391	>	* putAll, constructor with map argument, or deserialization.
392	>	* These cases attempt to override the initial capacity settings,
393	>	* but harmlessly fail to take effect in cases of races.
394	>	*
395	>	* The element count is maintained using a specialization of
396	>	* LongAdder. We need to incorporate a specialization rather than
397	>	* just use a LongAdder in order to access implicit
398	>	* contention-sensing that leads to creation of multiple
399	>	* CounterCells.  The counter mechanics avoid contention on
400	>	* updates but can encounter cache thrashing if read too
401	>	* frequently during concurrent access. To avoid reading so often,
402	>	* resizing under contention is attempted only upon adding to a
403	>	* bin already holding two or more nodes. Under uniform hash
404	>	* distributions, the probability of this occurring at threshold
405	>	* is around 13%, meaning that only about 1 in 8 puts check
406	>	* threshold (and after resizing, many fewer do so).
407	>	*
408	>	* TreeBins use a special form of comparison for search and
409	>	* related operations (which is the main reason we cannot use
410	>	* existing collections such as TreeMaps). TreeBins contain
411	>	* Comparable elements, but may contain others, as well as
412	>	* elements that are Comparable but not necessarily Comparable
413	>	* for the same T, so we cannot invoke compareTo among them. To
414	>	* handle this, the tree is ordered primarily by hash value, then
415	>	* by Comparable.compareTo order if applicable.  On lookup at a
416	>	* node, if elements are not comparable or compare as 0 then both
417	>	* left and right children may need to be searched in the case of
418	>	* tied hash values. (This corresponds to the full list search
419	>	* that would be necessary if all elements were non-Comparable and
420	>	* had tied hashes.)  The red-black balancing code is updated from
421	>	* pre-jdk-collections
422	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
423	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
424	>	* Algorithms" (CLR).
425	>	*
426	>	* TreeBins also require an additional locking mechanism.  While
427	>	* list traversal is always possible by readers evern during
428	>	* updates, tree traversal is not, mainly beause of tree-rotations
429	>	* that may change the root node and/or its linkages.  TreeBins
430	>	* include a simple read-write lock mechanism parasitic on the
431	>	* main bin-synchronization strategy: Structural adjustments
432	>	* associated with an insertion or removal are already bin-locked
433	>	* (and so cannot conflict with other writers) but must wait for
434	>	* ongoing readers to finish. Since there can be only one such
435	>	* waiter, we use a simple scheme using a single "waiter" field to
436	>	* block writers.  However, readers need never block.  If the root
437	>	* lock is held, they proceed along the slow traversal path (via
438	>	* next-pointers) until the lock becomes available or the list is
439	>	* exhausted, whichever comes first. These cases are not fast, but
440	>	* maximize aggregate expected throughput.
441	>	*
442	>	* Maintaining API and serialization compatibility with previous
443	>	* versions of this class introduces several oddities. Mainly: We
444	>	* leave untouched but unused constructor arguments refering to
445	>	* concurrencyLevel. We accept a loadFactor constructor argument,
446	>	* but apply it only to initial table capacity (which is the only
447	>	* time that we can guarantee to honor it.) We also declare an
448	>	* unused "Segment" class that is instantiated in minimal form
449	>	* only when serializing.
450	>	*
451	>	* This file is organized to make things a little easier to follow
452	>	* while reading than they might otherwise:. First the main static
453	>	* declarations and utilities, then fields, then main public
454	>	* methods (with a few factorings of multiple public methods into
455	>	* internal ones), then sizing methods, trees, traversers, and
456	>	* bulk operations.
457		*/
458
459		/* ---------------- Constants -------------- */
460
461		/**
462	<	* The default initial number of table slots for this table.
463	<	* Used when not otherwise specified in constructor.
462	>	* The largest possible table capacity.  This value must be
463	>	* exactly 1<<30 to stay within Java array allocation and indexing
464	>	* bounds for power of two table sizes, and is further required
465	>	* because the top two bits of 32bit hash fields are used for
466	>	* control purposes.
467		*/
468	<	private static int DEFAULT_INITIAL_CAPACITY = 16;
468	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
469
470		/**
471	<	* The maximum capacity, used if a higher value is implicitly
472	<	* specified by either of the constructors with arguments.  MUST
87	<	* be a power of two <= 1<<30 to ensure that entries are indexible
88	<	* using ints.
471	>	* The default initial table capacity.  Must be a power of 2
472	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
473		*/
474	<	static final int MAXIMUM_CAPACITY = 1 << 30;
474	>	private static final int DEFAULT_CAPACITY = 16;
475
476		/**
477	<	* The default load factor for this table.  Used when not
478	<	* otherwise specified in constructor.
477	>	* The largest possible (non-power of two) array size.
478	>	* Needed by toArray and related methods.
479		*/
480	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
480	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
481
482		/**
483	<	* The default number of concurrency control segments.
484	<	**/
485	<	private static final int DEFAULT_SEGMENTS = 16;
483	>	* The default concurrency level for this table. Unused but
484	>	* defined for compatibility with previous versions of this class.
485	>	*/
486	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
487
488		/**
489	<	* The maximum number of segments to allow; used to bound ctor arguments.
489	>	* The load factor for this table. Overrides of this value in
490	>	* constructors affect only the initial table capacity.  The
491	>	* actual floating point value isn't normally used -- it is
492	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
493	>	* the associated resizing threshold.
494		*/
495	<	private static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
495	>	private static final float LOAD_FACTOR = 0.75f;
496
497	<	/* ---------------- Fields -------------- */
497	>	/**
498	>	* The bin count threshold for using a tree rather than list for a
499	>	* bin.  Bins are converted to trees when adding an element to a
500	>	* bin with at least this many nodes. The value should be at least
501	>	* 8 to mesh with assumptions in tree removal about conversion
502	>	* back to plain bins upon shrinkage.
503	>	*/
504	>	static final int TREEIFY_THRESHOLD = 8;
505
506		/**
507	<	* Mask value for indexing into segments. The upper bits of a
508	<	* key's hash code are used to choose the segment.
509	<	**/
510	<	private final int segmentMask;
507	>	* The bin count threshold for untreeifying a (split) bin during a
508	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
509	>	* most 6 to mesh with shrinkage detection under removal.
510	>	*/
511	>	static final int UNTREEIFY_THRESHOLD = 6;
512
513		/**
514	<	* Shift value for indexing within segments.
515	<	**/
516	<	private final int segmentShift;
514	>	* The smallest table capacity for which bins may be treeified.
515	>	* (Otherwise the table is resized if too many nodes in a bin.)
516	>	* Should be at least 4 * TREEIFY_THRESHOLD to avoid conflicts
517	>	* between resizing and treeification thresholds.
518	>	*/
519	>	static final int MIN_TREEIFY_CAPACITY = 64;
520
521		/**
522	<	* The segments, each of which is a specialized hash table
522	>	* Minimum number of rebinnings per transfer step. Ranges are
523	>	* subdivided to allow multiple resizer threads.  This value
524	>	* serves as a lower bound to avoid resizers encountering
525	>	* excessive memory contention.  The value should be at least
526	>	* DEFAULT_CAPACITY.
527		*/
528	<	private final Segment[] segments;
528	>	private static final int MIN_TRANSFER_STRIDE = 16;
529
530	<	private transient Set<K> keySet;
531	<	private transient Set<Map.Entry<K,V>> entrySet;
532	<	private transient Collection<V> values;
530	>	/*
531	>	* Encodings for Node hash fields. See above for explanation.
532	>	*/
533	>	static final int MOVED     = 0x8fffffff; // (-1) hash for forwarding nodes
534	>	static final int TREEBIN   = 0x80000000; // hash for heads of treea
535	>	static final int RESERVED  = 0x80000001; // hash for transient reservations
536	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
537	>
538	>	/** Number of CPUS, to place bounds on some sizings */
539	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
540	>
541	>	/** For serialization compatibility. */
542	>	private static final ObjectStreamField[] serialPersistentFields = {
543	>	new ObjectStreamField("segments", Segment[].class),
544	>	new ObjectStreamField("segmentMask", Integer.TYPE),
545	>	new ObjectStreamField("segmentShift", Integer.TYPE)
546	>	};
547
548	<	/* ---------------- Small Utilities -------------- */
548	>	/* ---------------- Nodes -------------- */
549
550		/**
551	<	* Return a hash code for non-null Object x.
552	<	* Uses the same hash code spreader as most other j.u hash tables.
553	<	* @param x the object serving as a key
554	<	* @return the hash code
551	>	* Key-value entry.  This class is never exported out as a
552	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
553	>	* MapEntry below), but can be used for read-only traversals used
554	>	* in bulk tasks.  Subclasses of Node with a hash field of MOVED are special,
555	>	* and contain null keys and values (but are never exported).
556	>	* Otherwise, keys and vals are never null.
557		*/
558	<	private static int hash(Object x) {
559	<	int h = x.hashCode();
560	<	h += ~(h << 9);
561	<	h ^=  (h >>> 14);
562	<	h +=  (h << 4);
563	<	h ^=  (h >>> 10);
564	<	return h;
558	>	static class Node<K,V> implements Map.Entry<K,V> {
559	>	final int hash;
560	>	final K key;
561	>	volatile V val;
562	>	Node<K,V> next;
563	>
564	>	Node(int hash, K key, V val, Node<K,V> next) {
565	>	this.hash = hash;
566	>	this.key = key;
567	>	this.val = val;
568	>	this.next = next;
569	>	}
570	>
571	>	public final K getKey()       { return key; }
572	>	public final V getValue()     { return val; }
573	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
574	>	public final String toString(){ return key + "=" + val; }
575	>	public final V setValue(V value) {
576	>	throw new UnsupportedOperationException();
577	>	}
578	>
579	>	public final boolean equals(Object o) {
580	>	Object k, v, u; Map.Entry<?,?> e;
581	>	return ((o instanceof Map.Entry) &&
582	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
583	>	(v = e.getValue()) != null &&
584	>	(k == key || k.equals(key)) &&
585	>	(v == (u = val) || v.equals(u)));
586	>	}
587	>
588	>	Node<K,V> find(int h, Object k) {
589	>	Node<K,V> e = this;
590	>	if (k != null) {
591	>	do {
592	>	K ek;
593	>	if (e.hash == h &&
594	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
595	>	return e;
596	>	} while ((e = e.next) != null);
597	>	}
598	>	return null;
599	>	}
600		}
601
602	+	/* ---------------- Static utilities -------------- */
603	+
604		/**
605	<	* Return the segment that should be used for key with given hash
605	>	* Spreads (XORs) higher bits of hash to lower and also forces top
606	>	* bit to 0. Because the table uses power-of-two masking, sets of
607	>	* hashes that vary only in bits above the current mask will
608	>	* always collide. (Among known examples are sets of Float keys
609	>	* holding consecutive whole numbers in small tables.)  So we
610	>	* apply a transform that spreads the impact of higher bits
611	>	* downward. There is a tradeoff between speed, utility, and
612	>	* quality of bit-spreading. Because many common sets of hashes
613	>	* are already reasonably distributed (so don't benefit from
614	>	* spreading), and because we use trees to handle large sets of
615	>	* collisions in bins, we just XOR some shifted bits in the
616	>	* cheapest possible way to reduce systematic lossage, as well as
617	>	* to incorporate impact of the highest bits that would otherwise
618	>	* never be used in index calculations because of table bounds.
619		*/
620	<	private Segment<K,V> segmentFor(int hash) {
621	<	return (Segment<K,V>) segments[(hash >>> segmentShift) & segmentMask];
620	>	static final int spread(int h) {
621	>	return (h ^ (h >>> 16)) & HASH_BITS;
622		}
623
624	<	/* ---------------- Inner Classes -------------- */
624	>	/**
625	>	* Returns a power of two table size for the given desired capacity.
626	>	* See Hackers Delight, sec 3.2
627	>	*/
628	>	private static final int tableSizeFor(int c) {
629	>	int n = c - 1;
630	>	n |= n >>> 1;
631	>	n |= n >>> 2;
632	>	n |= n >>> 4;
633	>	n |= n >>> 8;
634	>	n |= n >>> 16;
635	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
636	>	}
637
638		/**
639	<	* Segments are specialized versions of hash tables.  This
640	<	* subclasses from ReentrantLock opportunistically, just to
641	<	* simplify some locking and avoid separate construction.
642	<	**/
643	<	private static final class Segment<K,V> extends ReentrantLock implements Serializable {
644	<	/*
645	<	* Segments maintain a table of entry lists that are ALWAYS
646	<	* kept in a consistent state, so can be read without locking.
647	<	* Next fields of nodes are immutable (final).  All list
648	<	* additions are performed at the front of each bin. This
649	<	* makes it easy to check changes, and also fast to traverse.
650	<	* When nodes would otherwise be changed, new nodes are
651	<	* created to replace them. This works well for hash tables
652	<	* since the bin lists tend to be short. (The average length
653	<	* is less than two for the default load factor threshold.)
654	<	*
655	<	* Read operations can thus proceed without locking, but rely
656	<	* on a memory barrier to ensure that completed write
657	<	* operations performed by other threads are
658	<	* noticed. Conveniently, the "count" field, tracking the
659	<	* number of elements, can also serve as the volatile variable
178	<	* providing proper read/write barriers. This is convenient
179	<	* because this field needs to be read in many read operations
180	<	* anyway.
181	<	*
182	<	* Implementors note. The basic rules for all this are:
183	<	*
184	<	*   - All unsynchronized read operations must first read the
185	<	*     "count" field, and should not look at table entries if
186	<	*     it is 0.
187	<	*
188	<	*   - All synchronized write operations should write to
189	<	*     the "count" field after updating. The operations must not
190	<	*     take any action that could even momentarily cause
191	<	*     a concurrent read operation to see inconsistent
192	<	*     data. This is made easier by the nature of the read
193	<	*     operations in Map. For example, no operation
194	<	*     can reveal that the table has grown but the threshold
195	<	*     has not yet been updated, so there are no atomicity
196	<	*     requirements for this with respect to reads.
197	<	*
198	<	* As a guide, all critical volatile reads and writes are marked
199	<	* in code comments.
200	<	*/
639	>	* Returns x's Class if it is of the form "class C implements
640	>	* Comparable<C>", else null.
641	>	*/
642	>	static Class<?> comparableClassFor(Object x) {
643	>	if (x instanceof Comparable) {
644	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
645	>	if ((c = x.getClass()) == String.class) // bypass checks
646	>	return c;
647	>	if ((ts = c.getGenericInterfaces()) != null) {
648	>	for (int i = 0; i < ts.length; ++i) {
649	>	if (((t = ts[i]) instanceof ParameterizedType) &&
650	>	((p = (ParameterizedType)t).getRawType() ==
651	>	Comparable.class) &&
652	>	(as = p.getActualTypeArguments()) != null &&
653	>	as.length == 1 && as[0] == c) // type arg is c
654	>	return c;
655	>	}
656	>	}
657	>	}
658	>	return null;
659	>	}
660
661	<	private static final long serialVersionUID = 2249069246763182397L;
661	>	/**
662	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
663	>	* class), else 0.
664	>	*/
665	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
666	>	static int compareComparables(Class<?> kc, Object k, Object x) {
667	>	return (x == null || x.getClass() != kc ? 0 :
668	>	((Comparable)k).compareTo(x));
669	>	}
670
671	<	/**
205	<	* The number of elements in this segment's region.
206	<	**/
207	<	transient volatile int count;
671	>	/* ---------------- Table element access -------------- */
672
673	<	/**
674	<	* Number of updates; used for checking lack of modifications
675	<	* in bulk-read methods.
676	<	*/
677	<	transient int modCount;
673	>	/*
674	>	* Volatile access methods are used for table elements as well as
675	>	* elements of in-progress next table while resizing.  All uses of
676	>	* the tab arguments must be null checked by callers.  All callers
677	>	* also paranoically precheck that tab's length is not zero (or an
678	>	* equivalent check), thus ensuring that any index argument taking
679	>	* the form of a hash value anded with (length - 1) is a valid
680	>	* index.  Note that, to be correct wrt arbitrary concurrency
681	>	* errors by users, these checks must operate on local variables,
682	>	* which accounts for some odd-looking inline assignments below.
683	>	* Note that calls to setTabAt always occur within locked regions,
684	>	* and so do not need full volatile semantics, but still require
685	>	* ordering to maintain concurrent readability.
686	>	*/
687
688	<	/**
689	<	* The table is rehashed when its size exceeds this threshold.
690	<	* (The value of this field is always (int)(capacity *
691	<	* loadFactor).)
219	<	*/
220	<	private transient int threshold;
688	>	@SuppressWarnings("unchecked")
689	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
690	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
691	>	}
692
693	<	/**
694	<	* The per-segment table
695	<	*/
696	<	transient HashEntry[] table;
693	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
694	>	Node<K,V> c, Node<K,V> v) {
695	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
696	>	}
697
698	<	/**
699	<	* The load factor for the hash table.  Even though this value
700	<	* is same for all segments, it is replicated to avoid needing
701	<	* links to outer object.
702	<	* @serial
703	<	*/
704	<	private final float loadFactor;
698	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
699	>	U.putOrderedObject(tab, ((long)i << ASHIFT) + ABASE, v);
700	>	}
701	>
702	>	/* ---------------- Fields -------------- */
703	>
704	>	/**
705	>	* The array of bins. Lazily initialized upon first insertion.
706	>	* Size is always a power of two. Accessed directly by iterators.
707	>	*/
708	>	transient volatile Node<K,V>[] table;
709	>
710	>	/**
711	>	* The next table to use; non-null only while resizing.
712	>	*/
713	>	private transient volatile Node<K,V>[] nextTable;
714	>
715	>	/**
716	>	* Base counter value, used mainly when there is no contention,
717	>	* but also as a fallback during table initialization
718	>	* races. Updated via CAS.
719	>	*/
720	>	private transient volatile long baseCount;
721	>
722	>	/**
723	>	* Table initialization and resizing control.  When negative, the
724	>	* table is being initialized or resized: -1 for initialization,
725	>	* else -(1 + the number of active resizing threads).  Otherwise,
726	>	* when table is null, holds the initial table size to use upon
727	>	* creation, or 0 for default. After initialization, holds the
728	>	* next element count value upon which to resize the table.
729	>	*/
730	>	private transient volatile int sizeCtl;
731	>
732	>	/**
733	>	* The next table index (plus one) to split while resizing.
734	>	*/
735	>	private transient volatile int transferIndex;
736	>
737	>	/**
738	>	* The least available table index to split while resizing.
739	>	*/
740	>	private transient volatile int transferOrigin;
741	>
742	>	/**
743	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
744	>	*/
745	>	private transient volatile int cellsBusy;
746	>
747	>	/**
748	>	* Table of counter cells. When non-null, size is a power of 2.
749	>	*/
750	>	private transient volatile CounterCell[] counterCells;
751	>
752	>	// views
753	>	private transient KeySetView<K,V> keySet;
754	>	private transient ValuesView<K,V> values;
755	>	private transient EntrySetView<K,V> entrySet;
756	>
757	>
758	>	/* ---------------- Public operations -------------- */
759	>
760	>	/**
761	>	* Creates a new, empty map with the default initial table size (16).
762	>	*/
763	>	public ConcurrentHashMap() {
764	>	}
765	>
766	>	/**
767	>	* Creates a new, empty map with an initial table size
768	>	* accommodating the specified number of elements without the need
769	>	* to dynamically resize.
770	>	*
771	>	* @param initialCapacity The implementation performs internal
772	>	* sizing to accommodate this many elements.
773	>	* @throws IllegalArgumentException if the initial capacity of
774	>	* elements is negative
775	>	*/
776	>	public ConcurrentHashMap(int initialCapacity) {
777	>	if (initialCapacity < 0)
778	>	throw new IllegalArgumentException();
779	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
780	>	MAXIMUM_CAPACITY :
781	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
782	>	this.sizeCtl = cap;
783	>	}
784	>
785	>	/**
786	>	* Creates a new map with the same mappings as the given map.
787	>	*
788	>	* @param m the map
789	>	*/
790	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
791	>	this.sizeCtl = DEFAULT_CAPACITY;
792	>	putAll(m);
793	>	}
794	>
795	>	/**
796	>	* Creates a new, empty map with an initial table size based on
797	>	* the given number of elements ({@code initialCapacity}) and
798	>	* initial table density ({@code loadFactor}).
799	>	*
800	>	* @param initialCapacity the initial capacity. The implementation
801	>	* performs internal sizing to accommodate this many elements,
802	>	* given the specified load factor.
803	>	* @param loadFactor the load factor (table density) for
804	>	* establishing the initial table size
805	>	* @throws IllegalArgumentException if the initial capacity of
806	>	* elements is negative or the load factor is nonpositive
807	>	*
808	>	* @since 1.6
809	>	*/
810	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
811	>	this(initialCapacity, loadFactor, 1);
812	>	}
813	>
814	>	/**
815	>	* Creates a new, empty map with an initial table size based on
816	>	* the given number of elements ({@code initialCapacity}), table
817	>	* density ({@code loadFactor}), and number of concurrently
818	>	* updating threads ({@code concurrencyLevel}).
819	>	*
820	>	* @param initialCapacity the initial capacity. The implementation
821	>	* performs internal sizing to accommodate this many elements,
822	>	* given the specified load factor.
823	>	* @param loadFactor the load factor (table density) for
824	>	* establishing the initial table size
825	>	* @param concurrencyLevel the estimated number of concurrently
826	>	* updating threads. The implementation may use this value as
827	>	* a sizing hint.
828	>	* @throws IllegalArgumentException if the initial capacity is
829	>	* negative or the load factor or concurrencyLevel are
830	>	* nonpositive
831	>	*/
832	>	public ConcurrentHashMap(int initialCapacity,
833	>	float loadFactor, int concurrencyLevel) {
834	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
835	>	throw new IllegalArgumentException();
836	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
837	>	initialCapacity = concurrencyLevel;   // as estimated threads
838	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
839	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
840	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
841	>	this.sizeCtl = cap;
842	>	}
843	>
844	>	// Original (since JDK1.2) Map methods
845	>
846	>	/**
847	>	* {@inheritDoc}
848	>	*/
849	>	public int size() {
850	>	long n = sumCount();
851	>	return ((n < 0L) ? 0 :
852	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
853	>	(int)n);
854	>	}
855
856	<	Segment(int initialCapacity, float lf) {
857	<	loadFactor = lf;
858	<	setTable(new HashEntry[initialCapacity]);
856	>	/**
857	>	* {@inheritDoc}
858	>	*/
859	>	public boolean isEmpty() {
860	>	return sumCount() <= 0L; // ignore transient negative values
861	>	}
862	>
863	>	/**
864	>	* Returns the value to which the specified key is mapped,
865	>	* or {@code null} if this map contains no mapping for the key.
866	>	*
867	>	* <p>More formally, if this map contains a mapping from a key
868	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
869	>	* then this method returns {@code v}; otherwise it returns
870	>	* {@code null}.  (There can be at most one such mapping.)
871	>	*
872	>	* @throws NullPointerException if the specified key is null
873	>	*/
874	>	public V get(Object key) {
875	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
876	>	int h = spread(key.hashCode());
877	>	if ((tab = table) != null && (n = tab.length) > 0 &&
878	>	(e = tabAt(tab, (n - 1) & h)) != null) {
879	>	if ((eh = e.hash) == h) {
880	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
881	>	return e.val;
882	>	}
883	>	else if (eh < 0)
884	>	return (p = e.find(h, key)) != null ? p.val : null;
885	>	while ((e = e.next) != null) {
886	>	if (e.hash == h &&
887	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
888	>	return e.val;
889	>	}
890		}
891	+	return null;
892	+	}
893
894	<	/**
895	<	* Set table to new HashEntry array.
896	<	* Call only while holding lock or in constructor.
897	<	**/
898	<	private void setTable(HashEntry[] newTable) {
899	<	table = newTable;
900	<	threshold = (int)(newTable.length * loadFactor);
901	<	count = count; // write-volatile
894	>	/**
895	>	* Tests if the specified object is a key in this table.
896	>	*
897	>	* @param  key possible key
898	>	* @return {@code true} if and only if the specified object
899	>	*         is a key in this table, as determined by the
900	>	*         {@code equals} method; {@code false} otherwise
901	>	* @throws NullPointerException if the specified key is null
902	>	*/
903	>	public boolean containsKey(Object key) {
904	>	return get(key) != null;
905	>	}
906	>
907	>	/**
908	>	* Returns {@code true} if this map maps one or more keys to the
909	>	* specified value. Note: This method may require a full traversal
910	>	* of the map, and is much slower than method {@code containsKey}.
911	>	*
912	>	* @param value value whose presence in this map is to be tested
913	>	* @return {@code true} if this map maps one or more keys to the
914	>	*         specified value
915	>	* @throws NullPointerException if the specified value is null
916	>	*/
917	>	public boolean containsValue(Object value) {
918	>	if (value == null)
919	>	throw new NullPointerException();
920	>	Node<K,V>[] t;
921	>	if ((t = table) != null) {
922	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
923	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
924	>	V v;
925	>	if ((v = p.val) == value || (v != null && value.equals(v)))
926	>	return true;
927	>	}
928		}
929	+	return false;
930	+	}
931
932	<	/* Specialized implementations of map methods */
932	>	/**
933	>	* Maps the specified key to the specified value in this table.
934	>	* Neither the key nor the value can be null.
935	>	*
936	>	* <p>The value can be retrieved by calling the {@code get} method
937	>	* with a key that is equal to the original key.
938	>	*
939	>	* @param key key with which the specified value is to be associated
940	>	* @param value value to be associated with the specified key
941	>	* @return the previous value associated with {@code key}, or
942	>	*         {@code null} if there was no mapping for {@code key}
943	>	* @throws NullPointerException if the specified key or value is null
944	>	*/
945	>	public V put(K key, V value) {
946	>	return putVal(key, value, false);
947	>	}
948
949	<	V get(Object key, int hash) {
950	<	if (count != 0) { // read-volatile
951	<	HashEntry[] tab = table;
952	<	int index = hash & (tab.length - 1);
953	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
954	<	while (e != null) {
955	<	if (e.hash == hash && key.equals(e.key))
956	<	return e.value;
957	<	e = e.next;
949	>	/** Implementation for put and putIfAbsent */
950	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
951	>	if (key == null || value == null) throw new NullPointerException();
952	>	int hash = spread(key.hashCode());
953	>	int binCount = 0;
954	>	for (Node<K,V>[] tab = table;;) {
955	>	Node<K,V> f; int n, i, fh;
956	>	if (tab == null || (n = tab.length) == 0)
957	>	tab = initTable();
958	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
959	>	if (casTabAt(tab, i, null,
960	>	new Node<K,V>(hash, key, value, null)))
961	>	break;                   // no lock when adding to empty bin
962	>	}
963	>	else if ((fh = f.hash) == MOVED)
964	>	tab = helpTransfer(tab, f);
965	>	else {
966	>	V oldVal = null;
967	>	synchronized (f) {
968	>	if (tabAt(tab, i) == f) {
969	>	if (fh >= 0) {
970	>	binCount = 1;
971	>	for (Node<K,V> e = f;; ++binCount) {
972	>	K ek;
973	>	if (e.hash == hash &&
974	>	((ek = e.key) == key ||
975	>	(ek != null && key.equals(ek)))) {
976	>	oldVal = e.val;
977	>	if (!onlyIfAbsent)
978	>	e.val = value;
979	>	break;
980	>	}
981	>	Node<K,V> pred = e;
982	>	if ((e = e.next) == null) {
983	>	pred.next = new Node<K,V>(hash, key,
984	>	value, null);
985	>	break;
986	>	}
987	>	}
988	>	}
989	>	else if (f instanceof TreeBin) {
990	>	Node<K,V> p;
991	>	binCount = 2;
992	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
993	>	value)) != null) {
994	>	oldVal = p.val;
995	>	if (!onlyIfAbsent)
996	>	p.val = value;
997	>	}
998	>	}
999	>	}
1000	>	}
1001	>	if (binCount != 0) {
1002	>	if (binCount >= TREEIFY_THRESHOLD)
1003	>	treeifyBin(tab, i);
1004	>	if (oldVal != null)
1005	>	return oldVal;
1006	>	break;
1007		}
1008		}
263	–	return null;
1009		}
1010	+	addCount(1L, binCount);
1011	+	return null;
1012	+	}
1013
1014	<	boolean containsKey(Object key, int hash) {
1015	<	if (count != 0) { // read-volatile
1016	<	HashEntry[] tab = table;
1017	<	int index = hash & (tab.length - 1);
1018	<	HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
1019	<	while (e != null) {
1020	<	if (e.hash == hash && key.equals(e.key))
1021	<	return true;
1022	<	e = e.next;
1014	>	/**
1015	>	* Copies all of the mappings from the specified map to this one.
1016	>	* These mappings replace any mappings that this map had for any of the
1017	>	* keys currently in the specified map.
1018	>	*
1019	>	* @param m mappings to be stored in this map
1020	>	*/
1021	>	public void putAll(Map<? extends K, ? extends V> m) {
1022	>	tryPresize(m.size());
1023	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1024	>	putVal(e.getKey(), e.getValue(), false);
1025	>	}
1026	>
1027	>	/**
1028	>	* Removes the key (and its corresponding value) from this map.
1029	>	* This method does nothing if the key is not in the map.
1030	>	*
1031	>	* @param  key the key that needs to be removed
1032	>	* @return the previous value associated with {@code key}, or
1033	>	*         {@code null} if there was no mapping for {@code key}
1034	>	* @throws NullPointerException if the specified key is null
1035	>	*/
1036	>	public V remove(Object key) {
1037	>	return replaceNode(key, null, null);
1038	>	}
1039	>
1040	>	/**
1041	>	* Implementation for the four public remove/replace methods:
1042	>	* Replaces node value with v, conditional upon match of cv if
1043	>	* non-null.  If resulting value is null, delete.
1044	>	*/
1045	>	final V replaceNode(Object key, V value, Object cv) {
1046	>	int hash = spread(key.hashCode());
1047	>	for (Node<K,V>[] tab = table;;) {
1048	>	Node<K,V> f; int n, i, fh;
1049	>	if (tab == null || (n = tab.length) == 0 ||
1050	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1051	>	break;
1052	>	else if ((fh = f.hash) == MOVED)
1053	>	tab = helpTransfer(tab, f);
1054	>	else {
1055	>	V oldVal = null;
1056	>	boolean validated = false;
1057	>	synchronized (f) {
1058	>	if (tabAt(tab, i) == f) {
1059	>	if (fh >= 0) {
1060	>	validated = true;
1061	>	for (Node<K,V> e = f, pred = null;;) {
1062	>	K ek;
1063	>	if (e.hash == hash &&
1064	>	((ek = e.key) == key ||
1065	>	(ek != null && key.equals(ek)))) {
1066	>	V ev = e.val;
1067	>	if (cv == null || cv == ev ||
1068	>	(ev != null && cv.equals(ev))) {
1069	>	oldVal = ev;
1070	>	if (value != null)
1071	>	e.val = value;
1072	>	else if (pred != null)
1073	>	pred.next = e.next;
1074	>	else
1075	>	setTabAt(tab, i, e.next);
1076	>	}
1077	>	break;
1078	>	}
1079	>	pred = e;
1080	>	if ((e = e.next) == null)
1081	>	break;
1082	>	}
1083	>	}
1084	>	else if (f instanceof TreeBin) {
1085	>	validated = true;
1086	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1087	>	TreeNode<K,V> r, p;
1088	>	if ((r = t.root) != null &&
1089	>	(p = r.findTreeNode(hash, key, null)) != null) {
1090	>	V pv = p.val;
1091	>	if (cv == null || cv == pv ||
1092	>	(pv != null && cv.equals(pv))) {
1093	>	oldVal = pv;
1094	>	if (value != null)
1095	>	p.val = value;
1096	>	else if (t.removeTreeNode(p))
1097	>	setTabAt(tab, i, untreeify(t.first));
1098	>	}
1099	>	}
1100	>	}
1101	>	}
1102	>	}
1103	>	if (validated) {
1104	>	if (oldVal != null) {
1105	>	if (value == null)
1106	>	addCount(-1L, -1);
1107	>	return oldVal;
1108	>	}
1109	>	break;
1110		}
1111		}
277	–	return false;
1112		}
1113	+	return null;
1114	+	}
1115
1116	<	boolean containsValue(Object value) {
1117	<	if (count != 0) { // read-volatile
1118	<	HashEntry[] tab = table;
1119	<	int len = tab.length;
1120	<	for (int i = 0 ; i < len; i++)
1121	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
1122	<	if (value.equals(e.value))
1123	<	return true;
1116	>	/**
1117	>	* Removes all of the mappings from this map.
1118	>	*/
1119	>	public void clear() {
1120	>	long delta = 0L; // negative number of deletions
1121	>	int i = 0;
1122	>	Node<K,V>[] tab = table;
1123	>	while (tab != null && i < tab.length) {
1124	>	int fh;
1125	>	Node<K,V> f = tabAt(tab, i);
1126	>	if (f == null)
1127	>	++i;
1128	>	else if ((fh = f.hash) == MOVED) {
1129	>	tab = helpTransfer(tab, f);
1130	>	i = 0; // restart
1131	>	}
1132	>	else {
1133	>	synchronized (f) {
1134	>	if (tabAt(tab, i) == f) {
1135	>	Node<K,V> p = (fh >= 0 ? f :
1136	>	(f instanceof TreeBin) ?
1137	>	((TreeBin<K,V>)f).first : null);
1138	>	while (p != null) {
1139	>	--delta;
1140	>	p = p.next;
1141	>	}
1142	>	setTabAt(tab, i++, null);
1143	>	}
1144	>	}
1145		}
289	–	return false;
1146		}
1147	+	if (delta != 0L)
1148	+	addCount(delta, -1);
1149	+	}
1150
1151	<	boolean replace(K key, int hash, V oldValue, V newValue) {
1152	<	lock();
1153	<	try {
1154	<	int c = count;
1155	<	HashEntry[] tab = table;
1156	<	int index = hash & (tab.length - 1);
1157	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1158	<	HashEntry<K,V> e = first;
1159	<	for (;;) {
1160	<	if (e == null)
1161	<	return false;
1162	<	if (e.hash == hash && key.equals(e.key))
1163	<	break;
1164	<	e = e.next;
1165	<	}
1151	>	/**
1152	>	* Returns a {@link Set} view of the keys contained in this map.
1153	>	* The set is backed by the map, so changes to the map are
1154	>	* reflected in the set, and vice-versa. The set supports element
1155	>	* removal, which removes the corresponding mapping from this map,
1156	>	* via the {@code Iterator.remove}, {@code Set.remove},
1157	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1158	>	* operations.  It does not support the {@code add} or
1159	>	* {@code addAll} operations.
1160	>	*
1161	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1162	>	* that will never throw {@link ConcurrentModificationException},
1163	>	* and guarantees to traverse elements as they existed upon
1164	>	* construction of the iterator, and may (but is not guaranteed to)
1165	>	* reflect any modifications subsequent to construction.
1166	>	*
1167	>	* @return the set view
1168	>	*/
1169	>	public KeySetView<K,V> keySet() {
1170	>	KeySetView<K,V> ks;
1171	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1172	>	}
1173
1174	<	V v = e.value;
1175	<	if (v == null || !oldValue.equals(v))
1176	<	return false;
1174	>	/**
1175	>	* Returns a {@link Collection} view of the values contained in this map.
1176	>	* The collection is backed by the map, so changes to the map are
1177	>	* reflected in the collection, and vice-versa.  The collection
1178	>	* supports element removal, which removes the corresponding
1179	>	* mapping from this map, via the {@code Iterator.remove},
1180	>	* {@code Collection.remove}, {@code removeAll},
1181	>	* {@code retainAll}, and {@code clear} operations.  It does not
1182	>	* support the {@code add} or {@code addAll} operations.
1183	>	*
1184	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1185	>	* that will never throw {@link ConcurrentModificationException},
1186	>	* and guarantees to traverse elements as they existed upon
1187	>	* construction of the iterator, and may (but is not guaranteed to)
1188	>	* reflect any modifications subsequent to construction.
1189	>	*
1190	>	* @return the collection view
1191	>	*/
1192	>	public Collection<V> values() {
1193	>	ValuesView<K,V> vs;
1194	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1195	>	}
1196
1197	<	e.value = newValue;
1198	<	count = c; // write-volatile
1199	<	return true;
1200	<
1201	<	} finally {
1202	<	unlock();
1203	<	}
1204	<	}
1197	>	/**
1198	>	* Returns a {@link Set} view of the mappings contained in this map.
1199	>	* The set is backed by the map, so changes to the map are
1200	>	* reflected in the set, and vice-versa.  The set supports element
1201	>	* removal, which removes the corresponding mapping from the map,
1202	>	* via the {@code Iterator.remove}, {@code Set.remove},
1203	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1204	>	* operations.
1205	>	*
1206	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1207	>	* that will never throw {@link ConcurrentModificationException},
1208	>	* and guarantees to traverse elements as they existed upon
1209	>	* construction of the iterator, and may (but is not guaranteed to)
1210	>	* reflect any modifications subsequent to construction.
1211	>	*
1212	>	* @return the set view
1213	>	*/
1214	>	public Set<Map.Entry<K,V>> entrySet() {
1215	>	EntrySetView<K,V> es;
1216	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1217	>	}
1218
1219	<	V replace(K key, int hash, V newValue) {
1220	<	lock();
1221	<	try {
1222	<	int c = count;
1223	<	HashEntry[] tab = table;
1224	<	int index = hash & (tab.length - 1);
1225	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1226	<	HashEntry<K,V> e = first;
1227	<	for (;;) {
1228	<	if (e == null)
1229	<	return null;
1230	<	if (e.hash == hash && key.equals(e.key))
1231	<	break;
1232	<	e = e.next;
1233	<	}
1219	>	/**
1220	>	* Returns the hash code value for this {@link Map}, i.e.,
1221	>	* the sum of, for each key-value pair in the map,
1222	>	* {@code key.hashCode() ^ value.hashCode()}.
1223	>	*
1224	>	* @return the hash code value for this map
1225	>	*/
1226	>	public int hashCode() {
1227	>	int h = 0;
1228	>	Node<K,V>[] t;
1229	>	if ((t = table) != null) {
1230	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1231	>	for (Node<K,V> p; (p = it.advance()) != null; )
1232	>	h += p.key.hashCode() ^ p.val.hashCode();
1233	>	}
1234	>	return h;
1235	>	}
1236
1237	<	V v = e.value;
1238	<	e.value = newValue;
1239	<	count = c; // write-volatile
1240	<	return v;
1241	<
1242	<	} finally {
1243	<	unlock();
1237	>	/**
1238	>	* Returns a string representation of this map.  The string
1239	>	* representation consists of a list of key-value mappings (in no
1240	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1241	>	* mappings are separated by the characters {@code ", "} (comma
1242	>	* and space).  Each key-value mapping is rendered as the key
1243	>	* followed by an equals sign ("{@code =}") followed by the
1244	>	* associated value.
1245	>	*
1246	>	* @return a string representation of this map
1247	>	*/
1248	>	public String toString() {
1249	>	Node<K,V>[] t;
1250	>	int f = (t = table) == null ? 0 : t.length;
1251	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1252	>	StringBuilder sb = new StringBuilder();
1253	>	sb.append('{');
1254	>	Node<K,V> p;
1255	>	if ((p = it.advance()) != null) {
1256	>	for (;;) {
1257	>	K k = p.key;
1258	>	V v = p.val;
1259	>	sb.append(k == this ? "(this Map)" : k);
1260	>	sb.append('=');
1261	>	sb.append(v == this ? "(this Map)" : v);
1262	>	if ((p = it.advance()) == null)
1263	>	break;
1264	>	sb.append(',').append(' ');
1265		}
1266		}
1267	+	return sb.append('}').toString();
1268	+	}
1269
1270	+	/**
1271	+	* Compares the specified object with this map for equality.
1272	+	* Returns {@code true} if the given object is a map with the same
1273	+	* mappings as this map.  This operation may return misleading
1274	+	* results if either map is concurrently modified during execution
1275	+	* of this method.
1276	+	*
1277	+	* @param o object to be compared for equality with this map
1278	+	* @return {@code true} if the specified object is equal to this map
1279	+	*/
1280	+	public boolean equals(Object o) {
1281	+	if (o != this) {
1282	+	if (!(o instanceof Map))
1283	+	return false;
1284	+	Map<?,?> m = (Map<?,?>) o;
1285	+	Node<K,V>[] t;
1286	+	int f = (t = table) == null ? 0 : t.length;
1287	+	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1288	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
1289	+	V val = p.val;
1290	+	Object v = m.get(p.key);
1291	+	if (v == null || (v != val && !v.equals(val)))
1292	+	return false;
1293	+	}
1294	+	for (Map.Entry<?,?> e : m.entrySet()) {
1295	+	Object mk, mv, v;
1296	+	if ((mk = e.getKey()) == null ||
1297	+	(mv = e.getValue()) == null ||
1298	+	(v = get(mk)) == null ||
1299	+	(mv != v && !mv.equals(v)))
1300	+	return false;
1301	+	}
1302	+	}
1303	+	return true;
1304	+	}
1305
1306	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
1307	<	lock();
1308	<	try {
1309	<	int c = count;
1310	<	HashEntry[] tab = table;
1311	<	int index = hash & (tab.length - 1);
1312	<	HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
1313	<
1314	<	for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
357	<	if (e.hash == hash && key.equals(e.key)) {
358	<	V oldValue = e.value;
359	<	if (!onlyIfAbsent)
360	<	e.value = value;
361	<	++modCount;
362	<	count = c; // write-volatile
363	<	return oldValue;
364	<	}
365	<	}
1306	>	/**
1307	>	* Stripped-down version of helper class used in previous version,
1308	>	* declared for the sake of serialization compatibility
1309	>	*/
1310	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1311	>	private static final long serialVersionUID = 2249069246763182397L;
1312	>	final float loadFactor;
1313	>	Segment(float lf) { this.loadFactor = lf; }
1314	>	}
1315
1316	<	tab[index] = new HashEntry<K,V>(hash, key, value, first);
1317	<	++modCount;
1318	<	++c;
1319	<	count = c; // write-volatile
1320	<	if (c > threshold)
1321	<	setTable(rehash(tab));
1322	<	return null;
1323	<	} finally {
1324	<	unlock();
1316	>	/**
1317	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1318	>	* stream (i.e., serializes it).
1319	>	* @param s the stream
1320	>	* @serialData
1321	>	* the key (Object) and value (Object)
1322	>	* for each key-value mapping, followed by a null pair.
1323	>	* The key-value mappings are emitted in no particular order.
1324	>	*/
1325	>	private void writeObject(java.io.ObjectOutputStream s)
1326	>	throws java.io.IOException {
1327	>	// For serialization compatibility
1328	>	// Emulate segment calculation from previous version of this class
1329	>	int sshift = 0;
1330	>	int ssize = 1;
1331	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1332	>	++sshift;
1333	>	ssize <<= 1;
1334	>	}
1335	>	int segmentShift = 32 - sshift;
1336	>	int segmentMask = ssize - 1;
1337	>	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1338	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1339	>	for (int i = 0; i < segments.length; ++i)
1340	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1341	>	s.putFields().put("segments", segments);
1342	>	s.putFields().put("segmentShift", segmentShift);
1343	>	s.putFields().put("segmentMask", segmentMask);
1344	>	s.writeFields();
1345	>
1346	>	Node<K,V>[] t;
1347	>	if ((t = table) != null) {
1348	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1349	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1350	>	s.writeObject(p.key);
1351	>	s.writeObject(p.val);
1352		}
1353		}
1354	+	s.writeObject(null);
1355	+	s.writeObject(null);
1356	+	segments = null; // throw away
1357	+	}
1358
1359	<	private HashEntry[] rehash(HashEntry[] oldTable) {
1360	<	int oldCapacity = oldTable.length;
1361	<	if (oldCapacity >= MAXIMUM_CAPACITY)
1362	<	return oldTable;
1363	<
1364	<	/*
1365	<	* Reclassify nodes in each list to new Map.  Because we are
1366	<	* using power-of-two expansion, the elements from each bin
1367	<	* must either stay at same index, or move with a power of two
1368	<	* offset. We eliminate unnecessary node creation by catching
1369	<	* cases where old nodes can be reused because their next
1370	<	* fields won't change. Statistically, at the default
1371	<	* threshold, only about one-sixth of them need cloning when
1372	<	* a table doubles. The nodes they replace will be garbage
1373	<	* collectable as soon as they are no longer referenced by any
1374	<	* reader thread that may be in the midst of traversing table
1375	<	* right now.
1376	<	*/
1377	<
1378	<	HashEntry[] newTable = new HashEntry[oldCapacity << 1];
1379	<	int sizeMask = newTable.length - 1;
1380	<	for (int i = 0; i < oldCapacity ; i++) {
1381	<	// We need to guarantee that any existing reads of old Map can
1382	<	//  proceed. So we cannot yet null out each bin.
1383	<	HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
1384	<
1385	<	if (e != null) {
1386	<	HashEntry<K,V> next = e.next;
1387	<	int idx = e.hash & sizeMask;
1388	<
1389	<	//  Single node on list
1390	<	if (next == null)
1391	<	newTable[idx] = e;
1392	<
1359	>	/**
1360	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1361	>	* @param s the stream
1362	>	*/
1363	>	private void readObject(java.io.ObjectInputStream s)
1364	>	throws java.io.IOException, ClassNotFoundException {
1365	>	/*
1366	>	* To improve performance in typical cases, we create nodes
1367	>	* while reading, then place in table once size is known.
1368	>	* However, we must also validate uniqueness and deal with
1369	>	* overpopulated bins while doing so, which requires
1370	>	* specialized versions of putVal mechanics.
1371	>	*/
1372	>	sizeCtl = -1; // force exclusion for table construction
1373	>	s.defaultReadObject();
1374	>	long size = 0L;
1375	>	Node<K,V> p = null;
1376	>	for (;;) {
1377	>	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1378	>	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1379	>	if (k != null && v != null) {
1380	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1381	>	++size;
1382	>	}
1383	>	else
1384	>	break;
1385	>	}
1386	>	if (size == 0L)
1387	>	sizeCtl = 0;
1388	>	else {
1389	>	int n;
1390	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1391	>	n = MAXIMUM_CAPACITY;
1392	>	else {
1393	>	int sz = (int)size;
1394	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1395	>	}
1396	>	@SuppressWarnings({"rawtypes","unchecked"})
1397	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1398	>	int mask = n - 1;
1399	>	long added = 0L;
1400	>	while (p != null) {
1401	>	boolean insertAtFront;
1402	>	Node<K,V> next = p.next, first;
1403	>	int h = p.hash, j = h & mask;
1404	>	if ((first = tabAt(tab, j)) == null)
1405	>	insertAtFront = true;
1406	>	else {
1407	>	K k = p.key;
1408	>	if (first.hash < 0) {
1409	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1410	>	if (t.putTreeVal(h, k, p.val) == null)
1411	>	++added;
1412	>	insertAtFront = false;
1413	>	}
1414		else {
1415	<	// Reuse trailing consecutive sequence at same slot
1416	<	HashEntry<K,V> lastRun = e;
1417	<	int lastIdx = idx;
1418	<	for (HashEntry<K,V> last = next;
1419	<	last != null;
1420	<	last = last.next) {
1421	<	int k = last.hash & sizeMask;
1422	<	if (k != lastIdx) {
1423	<	lastIdx = k;
423	<	lastRun = last;
1415	>	int binCount = 0;
1416	>	insertAtFront = true;
1417	>	Node<K,V> q; K qk;
1418	>	for (q = first; q != null; q = q.next) {
1419	>	if (q.hash == h &&
1420	>	((qk = q.key) == k ||
1421	>	(qk != null && k.equals(qk)))) {
1422	>	insertAtFront = false;
1423	>	break;
1424		}
1425	+	++binCount;
1426		}
1427	<	newTable[lastIdx] = lastRun;
1428	<
1429	<	// Clone all remaining nodes
1430	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1431	<	int k = p.hash & sizeMask;
1432	<	newTable[k] = new HashEntry<K,V>(p.hash,
1433	<	p.key,
1434	<	p.value,
1435	<	(HashEntry<K,V>) newTable[k]);
1427	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1428	>	insertAtFront = false;
1429	>	++added;
1430	>	p.next = first;
1431	>	TreeNode<K,V> hd = null, tl = null;
1432	>	for (q = p; q != null; q = q.next) {
1433	>	TreeNode<K,V> t = new TreeNode<K,V>
1434	>	(q.hash, q.key, q.val, null, null);
1435	>	if ((t.prev = tl) == null)
1436	>	hd = t;
1437	>	else
1438	>	tl.next = t;
1439	>	tl = t;
1440	>	}
1441	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1442		}
1443		}
1444		}
1445	+	if (insertAtFront) {
1446	+	++added;
1447	+	p.next = first;
1448	+	setTabAt(tab, j, p);
1449	+	}
1450	+	p = next;
1451		}
1452	<	return newTable;
1452	>	table = tab;
1453	>	sizeCtl = n - (n >>> 2);
1454	>	baseCount = added;
1455		}
1456	+	}
1457
1458	<	/**
443	<	* Remove; match on key only if value null, else match both.
444	<	*/
445	<	V remove(Object key, int hash, Object value) {
446	<	lock();
447	<	try {
448	<	int c = count;
449	<	HashEntry[] tab = table;
450	<	int index = hash & (tab.length - 1);
451	<	HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
1458	>	// ConcurrentMap methods
1459
1460	<	HashEntry<K,V> e = first;
1461	<	for (;;) {
1462	<	if (e == null)
1463	<	return null;
1464	<	if (e.hash == hash && key.equals(e.key))
1460	>	/**
1461	>	* {@inheritDoc}
1462	>	*
1463	>	* @return the previous value associated with the specified key,
1464	>	*         or {@code null} if there was no mapping for the key
1465	>	* @throws NullPointerException if the specified key or value is null
1466	>	*/
1467	>	public V putIfAbsent(K key, V value) {
1468	>	return putVal(key, value, true);
1469	>	}
1470	>
1471	>	/**
1472	>	* {@inheritDoc}
1473	>	*
1474	>	* @throws NullPointerException if the specified key is null
1475	>	*/
1476	>	public boolean remove(Object key, Object value) {
1477	>	if (key == null)
1478	>	throw new NullPointerException();
1479	>	return value != null && replaceNode(key, null, value) != null;
1480	>	}
1481	>
1482	>	/**
1483	>	* {@inheritDoc}
1484	>	*
1485	>	* @throws NullPointerException if any of the arguments are null
1486	>	*/
1487	>	public boolean replace(K key, V oldValue, V newValue) {
1488	>	if (key == null || oldValue == null || newValue == null)
1489	>	throw new NullPointerException();
1490	>	return replaceNode(key, newValue, oldValue) != null;
1491	>	}
1492	>
1493	>	/**
1494	>	* {@inheritDoc}
1495	>	*
1496	>	* @return the previous value associated with the specified key,
1497	>	*         or {@code null} if there was no mapping for the key
1498	>	* @throws NullPointerException if the specified key or value is null
1499	>	*/
1500	>	public V replace(K key, V value) {
1501	>	if (key == null || value == null)
1502	>	throw new NullPointerException();
1503	>	return replaceNode(key, value, null);
1504	>	}
1505	>
1506	>	// Overrides of JDK8+ Map extension method defaults
1507	>
1508	>	/**
1509	>	* Returns the value to which the specified key is mapped, or the
1510	>	* given default value if this map contains no mapping for the
1511	>	* key.
1512	>	*
1513	>	* @param key the key whose associated value is to be returned
1514	>	* @param defaultValue the value to return if this map contains
1515	>	* no mapping for the given key
1516	>	* @return the mapping for the key, if present; else the default value
1517	>	* @throws NullPointerException if the specified key is null
1518	>	*/
1519	>	public V getOrDefault(Object key, V defaultValue) {
1520	>	V v;
1521	>	return (v = get(key)) == null ? defaultValue : v;
1522	>	}
1523	>
1524	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1525	>	if (action == null) throw new NullPointerException();
1526	>	Node<K,V>[] t;
1527	>	if ((t = table) != null) {
1528	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1529	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1530	>	action.accept(p.key, p.val);
1531	>	}
1532	>	}
1533	>	}
1534	>
1535	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1536	>	if (function == null) throw new NullPointerException();
1537	>	Node<K,V>[] t;
1538	>	if ((t = table) != null) {
1539	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1540	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1541	>	V oldValue = p.val;
1542	>	for (K key = p.key;;) {
1543	>	V newValue = function.apply(key, oldValue);
1544	>	if (newValue == null)
1545	>	throw new NullPointerException();
1546	>	if (replaceNode(key, newValue, oldValue) != null ||
1547	>	(oldValue = get(key)) == null)
1548		break;
459	–	e = e.next;
1549		}
1550	+	}
1551	+	}
1552	+	}
1553
1554	<	V oldValue = e.value;
1555	<	if (value != null && !value.equals(oldValue))
1556	<	return null;
1557	<
1558	<	// All entries following removed node can stay in list, but
1559	<	// all preceding ones need to be cloned.
1560	<	HashEntry<K,V> newFirst = e.next;
1561	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
1562	<	newFirst = new HashEntry<K,V>(p.hash, p.key,
1563	<	p.value, newFirst);
1564	<	tab[index] = newFirst;
1565	<	++modCount;
1566	<	count = c-1; // write-volatile
1567	<	return oldValue;
1568	<	} finally {
1569	<	unlock();
1554	>	/**
1555	>	* If the specified key is not already associated with a value,
1556	>	* attempts to compute its value using the given mapping function
1557	>	* and enters it into this map unless {@code null}.  The entire
1558	>	* method invocation is performed atomically, so the function is
1559	>	* applied at most once per key.  Some attempted update operations
1560	>	* on this map by other threads may be blocked while computation
1561	>	* is in progress, so the computation should be short and simple,
1562	>	* and must not attempt to update any other mappings of this map.
1563	>	*
1564	>	* @param key key with which the specified value is to be associated
1565	>	* @param mappingFunction the function to compute a value
1566	>	* @return the current (existing or computed) value associated with
1567	>	*         the specified key, or null if the computed value is null
1568	>	* @throws NullPointerException if the specified key or mappingFunction
1569	>	*         is null
1570	>	* @throws IllegalStateException if the computation detectably
1571	>	*         attempts a recursive update to this map that would
1572	>	*         otherwise never complete
1573	>	* @throws RuntimeException or Error if the mappingFunction does so,
1574	>	*         in which case the mapping is left unestablished
1575	>	*/
1576	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1577	>	if (key == null || mappingFunction == null)
1578	>	throw new NullPointerException();
1579	>	int h = spread(key.hashCode());
1580	>	V val = null;
1581	>	int binCount = 0;
1582	>	for (Node<K,V>[] tab = table;;) {
1583	>	Node<K,V> f; int n, i, fh;
1584	>	if (tab == null || (n = tab.length) == 0)
1585	>	tab = initTable();
1586	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1587	>	Node<K,V> r = new ReservationNode<K,V>();
1588	>	synchronized (r) {
1589	>	if (casTabAt(tab, i, null, r)) {
1590	>	binCount = 1;
1591	>	Node<K,V> node = null;
1592	>	try {
1593	>	if ((val = mappingFunction.apply(key)) != null)
1594	>	node = new Node<K,V>(h, key, val, null);
1595	>	} finally {
1596	>	setTabAt(tab, i, node);
1597	>	}
1598	>	}
1599	>	}
1600	>	if (binCount != 0)
1601	>	break;
1602	>	}
1603	>	else if ((fh = f.hash) == MOVED)
1604	>	tab = helpTransfer(tab, f);
1605	>	else {
1606	>	boolean added = false;
1607	>	synchronized (f) {
1608	>	if (tabAt(tab, i) == f) {
1609	>	if (fh >= 0) {
1610	>	binCount = 1;
1611	>	for (Node<K,V> e = f;; ++binCount) {
1612	>	K ek; V ev;
1613	>	if (e.hash == h &&
1614	>	((ek = e.key) == key ||
1615	>	(ek != null && key.equals(ek)))) {
1616	>	val = e.val;
1617	>	break;
1618	>	}
1619	>	Node<K,V> pred = e;
1620	>	if ((e = e.next) == null) {
1621	>	if ((val = mappingFunction.apply(key)) != null) {
1622	>	added = true;
1623	>	pred.next = new Node<K,V>(h, key, val, null);
1624	>	}
1625	>	break;
1626	>	}
1627	>	}
1628	>	}
1629	>	else if (f instanceof TreeBin) {
1630	>	binCount = 2;
1631	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1632	>	TreeNode<K,V> r, p;
1633	>	if ((r = t.root) != null &&
1634	>	(p = r.findTreeNode(h, key, null)) != null)
1635	>	val = p.val;
1636	>	else if ((val = mappingFunction.apply(key)) != null) {
1637	>	added = true;
1638	>	t.putTreeVal(h, key, val);
1639	>	}
1640	>	}
1641	>	}
1642	>	}
1643	>	if (binCount != 0) {
1644	>	if (binCount >= TREEIFY_THRESHOLD)
1645	>	treeifyBin(tab, i);
1646	>	if (!added)
1647	>	return val;
1648	>	break;
1649	>	}
1650		}
1651		}
1652	+	if (val != null)
1653	+	addCount(1L, binCount);
1654	+	return val;
1655	+	}
1656
1657	<	void clear() {
1658	<	lock();
1659	<	try {
1660	<	HashEntry[] tab = table;
1661	<	for (int i = 0; i < tab.length ; i++)
1662	<	tab[i] = null;
1663	<	++modCount;
1664	<	count = 0; // write-volatile
1665	<	} finally {
1666	<	unlock();
1657	>	/**
1658	>	* If the value for the specified key is present, attempts to
1659	>	* compute a new mapping given the key and its current mapped
1660	>	* value.  The entire method invocation is performed atomically.
1661	>	* Some attempted update operations on this map by other threads
1662	>	* may be blocked while computation is in progress, so the
1663	>	* computation should be short and simple, and must not attempt to
1664	>	* update any other mappings of this map.
1665	>	*
1666	>	* @param key key with which a value may be associated
1667	>	* @param remappingFunction the function to compute a value
1668	>	* @return the new value associated with the specified key, or null if none
1669	>	* @throws NullPointerException if the specified key or remappingFunction
1670	>	*         is null
1671	>	* @throws IllegalStateException if the computation detectably
1672	>	*         attempts a recursive update to this map that would
1673	>	*         otherwise never complete
1674	>	* @throws RuntimeException or Error if the remappingFunction does so,
1675	>	*         in which case the mapping is unchanged
1676	>	*/
1677	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1678	>	if (key == null || remappingFunction == null)
1679	>	throw new NullPointerException();
1680	>	int h = spread(key.hashCode());
1681	>	V val = null;
1682	>	int delta = 0;
1683	>	int binCount = 0;
1684	>	for (Node<K,V>[] tab = table;;) {
1685	>	Node<K,V> f; int n, i, fh;
1686	>	if (tab == null || (n = tab.length) == 0)
1687	>	tab = initTable();
1688	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1689	>	break;
1690	>	else if ((fh = f.hash) == MOVED)
1691	>	tab = helpTransfer(tab, f);
1692	>	else {
1693	>	synchronized (f) {
1694	>	if (tabAt(tab, i) == f) {
1695	>	if (fh >= 0) {
1696	>	binCount = 1;
1697	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1698	>	K ek;
1699	>	if (e.hash == h &&
1700	>	((ek = e.key) == key ||
1701	>	(ek != null && key.equals(ek)))) {
1702	>	val = remappingFunction.apply(key, e.val);
1703	>	if (val != null)
1704	>	e.val = val;
1705	>	else {
1706	>	delta = -1;
1707	>	Node<K,V> en = e.next;
1708	>	if (pred != null)
1709	>	pred.next = en;
1710	>	else
1711	>	setTabAt(tab, i, en);
1712	>	}
1713	>	break;
1714	>	}
1715	>	pred = e;
1716	>	if ((e = e.next) == null)
1717	>	break;
1718	>	}
1719	>	}
1720	>	else if (f instanceof TreeBin) {
1721	>	binCount = 2;
1722	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1723	>	TreeNode<K,V> r, p;
1724	>	if ((r = t.root) != null &&
1725	>	(p = r.findTreeNode(h, key, null)) != null) {
1726	>	val = remappingFunction.apply(key, p.val);
1727	>	if (val != null)
1728	>	p.val = val;
1729	>	else {
1730	>	delta = -1;
1731	>	if (t.removeTreeNode(p))
1732	>	setTabAt(tab, i, untreeify(t.first));
1733	>	}
1734	>	}
1735	>	}
1736	>	}
1737	>	}
1738	>	if (binCount != 0)
1739	>	break;
1740		}
1741		}
1742	+	if (delta != 0)
1743	+	addCount((long)delta, binCount);
1744	+	return val;
1745		}
1746
1747		/**
1748	<	* ConcurrentHashMap list entry. Note that this is never exported
1749	<	* out as a user-visible Map.Entry
1748	>	* Attempts to compute a mapping for the specified key and its
1749	>	* current mapped value (or {@code null} if there is no current
1750	>	* mapping). The entire method invocation is performed atomically.
1751	>	* Some attempted update operations on this map by other threads
1752	>	* may be blocked while computation is in progress, so the
1753	>	* computation should be short and simple, and must not attempt to
1754	>	* update any other mappings of this Map.
1755	>	*
1756	>	* @param key key with which the specified value is to be associated
1757	>	* @param remappingFunction the function to compute a value
1758	>	* @return the new value associated with the specified key, or null if none
1759	>	* @throws NullPointerException if the specified key or remappingFunction
1760	>	*         is null
1761	>	* @throws IllegalStateException if the computation detectably
1762	>	*         attempts a recursive update to this map that would
1763	>	*         otherwise never complete
1764	>	* @throws RuntimeException or Error if the remappingFunction does so,
1765	>	*         in which case the mapping is unchanged
1766		*/
1767	<	private static class HashEntry<K,V> {
1768	<	private final K key;
1769	<	private V value;
1770	<	private final int hash;
1771	<	private final HashEntry<K,V> next;
1767	>	public V compute(K key,
1768	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1769	>	if (key == null || remappingFunction == null)
1770	>	throw new NullPointerException();
1771	>	int h = spread(key.hashCode());
1772	>	V val = null;
1773	>	int delta = 0;
1774	>	int binCount = 0;
1775	>	for (Node<K,V>[] tab = table;;) {
1776	>	Node<K,V> f; int n, i, fh;
1777	>	if (tab == null || (n = tab.length) == 0)
1778	>	tab = initTable();
1779	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1780	>	Node<K,V> r = new ReservationNode<K,V>();
1781	>	synchronized (r) {
1782	>	if (casTabAt(tab, i, null, r)) {
1783	>	binCount = 1;
1784	>	Node<K,V> node = null;
1785	>	try {
1786	>	if ((val = remappingFunction.apply(key, null)) != null) {
1787	>	delta = 1;
1788	>	node = new Node<K,V>(h, key, val, null);
1789	>	}
1790	>	} finally {
1791	>	setTabAt(tab, i, node);
1792	>	}
1793	>	}
1794	>	}
1795	>	if (binCount != 0)
1796	>	break;
1797	>	}
1798	>	else if ((fh = f.hash) == MOVED)
1799	>	tab = helpTransfer(tab, f);
1800	>	else {
1801	>	synchronized (f) {
1802	>	if (tabAt(tab, i) == f) {
1803	>	if (fh >= 0) {
1804	>	binCount = 1;
1805	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1806	>	K ek;
1807	>	if (e.hash == h &&
1808	>	((ek = e.key) == key ||
1809	>	(ek != null && key.equals(ek)))) {
1810	>	val = remappingFunction.apply(key, e.val);
1811	>	if (val != null)
1812	>	e.val = val;
1813	>	else {
1814	>	delta = -1;
1815	>	Node<K,V> en = e.next;
1816	>	if (pred != null)
1817	>	pred.next = en;
1818	>	else
1819	>	setTabAt(tab, i, en);
1820	>	}
1821	>	break;
1822	>	}
1823	>	pred = e;
1824	>	if ((e = e.next) == null) {
1825	>	val = remappingFunction.apply(key, null);
1826	>	if (val != null) {
1827	>	delta = 1;
1828	>	pred.next =
1829	>	new Node<K,V>(h, key, val, null);
1830	>	}
1831	>	break;
1832	>	}
1833	>	}
1834	>	}
1835	>	else if (f instanceof TreeBin) {
1836	>	binCount = 1;
1837	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1838	>	TreeNode<K,V> r, p;
1839	>	if ((r = t.root) != null)
1840	>	p = r.findTreeNode(h, key, null);
1841	>	else
1842	>	p = null;
1843	>	V pv = (p == null) ? null : p.val;
1844	>	val = remappingFunction.apply(key, pv);
1845	>	if (val != null) {
1846	>	if (p != null)
1847	>	p.val = val;
1848	>	else {
1849	>	delta = 1;
1850	>	t.putTreeVal(h, key, val);
1851	>	}
1852	>	}
1853	>	else if (p != null) {
1854	>	delta = -1;
1855	>	if (t.removeTreeNode(p))
1856	>	setTabAt(tab, i, untreeify(t.first));
1857	>	}
1858	>	}
1859	>	}
1860	>	}
1861	>	if (binCount != 0) {
1862	>	if (binCount >= TREEIFY_THRESHOLD)
1863	>	treeifyBin(tab, i);
1864	>	break;
1865	>	}
1866	>	}
1867	>	}
1868	>	if (delta != 0)
1869	>	addCount((long)delta, binCount);
1870	>	return val;
1871	>	}
1872
1873	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
1874	<	this.value = value;
1875	<	this.hash = hash;
1876	<	this.key = key;
1877	<	this.next = next;
1873	>	/**
1874	>	* If the specified key is not already associated with a
1875	>	* (non-null) value, associates it with the given value.
1876	>	* Otherwise, replaces the value with the results of the given
1877	>	* remapping function, or removes if {@code null}. The entire
1878	>	* method invocation is performed atomically.  Some attempted
1879	>	* update operations on this map by other threads may be blocked
1880	>	* while computation is in progress, so the computation should be
1881	>	* short and simple, and must not attempt to update any other
1882	>	* mappings of this Map.
1883	>	*
1884	>	* @param key key with which the specified value is to be associated
1885	>	* @param value the value to use if absent
1886	>	* @param remappingFunction the function to recompute a value if present
1887	>	* @return the new value associated with the specified key, or null if none
1888	>	* @throws NullPointerException if the specified key or the
1889	>	*         remappingFunction is null
1890	>	* @throws RuntimeException or Error if the remappingFunction does so,
1891	>	*         in which case the mapping is unchanged
1892	>	*/
1893	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1894	>	if (key == null || value == null || remappingFunction == null)
1895	>	throw new NullPointerException();
1896	>	int h = spread(key.hashCode());
1897	>	V val = null;
1898	>	int delta = 0;
1899	>	int binCount = 0;
1900	>	for (Node<K,V>[] tab = table;;) {
1901	>	Node<K,V> f; int n, i, fh;
1902	>	if (tab == null || (n = tab.length) == 0)
1903	>	tab = initTable();
1904	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1905	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1906	>	delta = 1;
1907	>	val = value;
1908	>	break;
1909	>	}
1910	>	}
1911	>	else if ((fh = f.hash) == MOVED)
1912	>	tab = helpTransfer(tab, f);
1913	>	else {
1914	>	synchronized (f) {
1915	>	if (tabAt(tab, i) == f) {
1916	>	if (fh >= 0) {
1917	>	binCount = 1;
1918	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1919	>	K ek;
1920	>	if (e.hash == h &&
1921	>	((ek = e.key) == key ||
1922	>	(ek != null && key.equals(ek)))) {
1923	>	val = remappingFunction.apply(e.val, value);
1924	>	if (val != null)
1925	>	e.val = val;
1926	>	else {
1927	>	delta = -1;
1928	>	Node<K,V> en = e.next;
1929	>	if (pred != null)
1930	>	pred.next = en;
1931	>	else
1932	>	setTabAt(tab, i, en);
1933	>	}
1934	>	break;
1935	>	}
1936	>	pred = e;
1937	>	if ((e = e.next) == null) {
1938	>	delta = 1;
1939	>	val = value;
1940	>	pred.next =
1941	>	new Node<K,V>(h, key, val, null);
1942	>	break;
1943	>	}
1944	>	}
1945	>	}
1946	>	else if (f instanceof TreeBin) {
1947	>	binCount = 2;
1948	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1949	>	TreeNode<K,V> r = t.root;
1950	>	TreeNode<K,V> p = (r == null) ? null :
1951	>	r.findTreeNode(h, key, null);
1952	>	val = (p == null) ? value :
1953	>	remappingFunction.apply(p.val, value);
1954	>	if (val != null) {
1955	>	if (p != null)
1956	>	p.val = val;
1957	>	else {
1958	>	delta = 1;
1959	>	t.putTreeVal(h, key, val);
1960	>	}
1961	>	}
1962	>	else if (p != null) {
1963	>	delta = -1;
1964	>	if (t.removeTreeNode(p))
1965	>	setTabAt(tab, i, untreeify(t.first));
1966	>	}
1967	>	}
1968	>	}
1969	>	}
1970	>	if (binCount != 0) {
1971	>	if (binCount >= TREEIFY_THRESHOLD)
1972	>	treeifyBin(tab, i);
1973	>	break;
1974	>	}
1975	>	}
1976		}
1977	+	if (delta != 0)
1978	+	addCount((long)delta, binCount);
1979	+	return val;
1980		}
1981
1982	+	// Hashtable legacy methods
1983
1984	<	/* ---------------- Public operations -------------- */
1984	>	/**
1985	>	* Legacy method testing if some key maps into the specified value
1986	>	* in this table.  This method is identical in functionality to
1987	>	* {@link #containsValue(Object)}, and exists solely to ensure
1988	>	* full compatibility with class {@link java.util.Hashtable},
1989	>	* which supported this method prior to introduction of the
1990	>	* Java Collections framework.
1991	>	*
1992	>	* @param  value a value to search for
1993	>	* @return {@code true} if and only if some key maps to the
1994	>	*         {@code value} argument in this table as
1995	>	*         determined by the {@code equals} method;
1996	>	*         {@code false} otherwise
1997	>	* @throws NullPointerException if the specified value is null
1998	>	*/
1999	>	@Deprecated public boolean contains(Object value) {
2000	>	return containsValue(value);
2001	>	}
2002
2003		/**
2004	<	* Constructs a new, empty map with the specified initial
518	<	* capacity and the specified load factor.
2004	>	* Returns an enumeration of the keys in this table.
2005		*
2006	<	* @param initialCapacity the initial capacity. The implementation
2007	<	* performs internal sizing to accommodate this many elements.
522	<	* @param loadFactor  the load factor threshold, used to control resizing.
523	<	* @param concurrencyLevel the estimated number of concurrently
524	<	* updating threads. The implementation performs internal sizing
525	<	* to try to accommodate this many threads.
526	<	* @throws IllegalArgumentException if the initial capacity is
527	<	* negative or the load factor or concurrencyLevel are
528	<	* nonpositive.
2006	>	* @return an enumeration of the keys in this table
2007	>	* @see #keySet()
2008		*/
2009	<	public ConcurrentHashMap(int initialCapacity,
2010	<	float loadFactor, int concurrencyLevel) {
2011	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
2012	<	throw new IllegalArgumentException();
2009	>	public Enumeration<K> keys() {
2010	>	Node<K,V>[] t;
2011	>	int f = (t = table) == null ? 0 : t.length;
2012	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2013	>	}
2014
2015	<	if (concurrencyLevel > MAX_SEGMENTS)
2016	<	concurrencyLevel = MAX_SEGMENTS;
2015	>	/**
2016	>	* Returns an enumeration of the values in this table.
2017	>	*
2018	>	* @return an enumeration of the values in this table
2019	>	* @see #values()
2020	>	*/
2021	>	public Enumeration<V> elements() {
2022	>	Node<K,V>[] t;
2023	>	int f = (t = table) == null ? 0 : t.length;
2024	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2025	>	}
2026
2027	<	// Find power-of-two sizes best matching arguments
539	<	int sshift = 0;
540	<	int ssize = 1;
541	<	while (ssize < concurrencyLevel) {
542	<	++sshift;
543	<	ssize <<= 1;
544	<	}
545	<	segmentShift = 32 - sshift;
546	<	segmentMask = ssize - 1;
547	<	this.segments = new Segment[ssize];
548	<
549	<	if (initialCapacity > MAXIMUM_CAPACITY)
550	<	initialCapacity = MAXIMUM_CAPACITY;
551	<	int c = initialCapacity / ssize;
552	<	if (c * ssize < initialCapacity)
553	<	++c;
554	<	int cap = 1;
555	<	while (cap < c)
556	<	cap <<= 1;
2027	>	// ConcurrentHashMap-only methods
2028
2029	<	for (int i = 0; i < this.segments.length; ++i)
2030	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
2029	>	/**
2030	>	* Returns the number of mappings. This method should be used
2031	>	* instead of {@link #size} because a ConcurrentHashMap may
2032	>	* contain more mappings than can be represented as an int. The
2033	>	* value returned is an estimate; the actual count may differ if
2034	>	* there are concurrent insertions or removals.
2035	>	*
2036	>	* @return the number of mappings
2037	>	* @since 1.8
2038	>	*/
2039	>	public long mappingCount() {
2040	>	long n = sumCount();
2041	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2042	>	}
2043	>
2044	>	/**
2045	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2046	>	* from the given type to {@code Boolean.TRUE}.
2047	>	*
2048	>	* @return the new set
2049	>	* @since 1.8
2050	>	*/
2051	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2052	>	return new KeySetView<K,Boolean>
2053	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2054		}
2055
2056		/**
2057	<	* Constructs a new, empty map with the specified initial
2058	<	* capacity,  and with default load factor and concurrencyLevel.
2057	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2058	>	* from the given type to {@code Boolean.TRUE}.
2059		*
2060		* @param initialCapacity The implementation performs internal
2061		* sizing to accommodate this many elements.
2062		* @throws IllegalArgumentException if the initial capacity of
2063	<	* elements is negative.
2063	>	* elements is negative
2064	>	* @return the new set
2065	>	* @since 1.8
2066		*/
2067	<	public ConcurrentHashMap(int initialCapacity) {
2068	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2067	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2068	>	return new KeySetView<K,Boolean>
2069	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2070		}
2071
2072		/**
2073	<	* Constructs a new, empty map with a default initial capacity,
2074	<	* load factor, and concurrencyLevel.
2073	>	* Returns a {@link Set} view of the keys in this map, using the
2074	>	* given common mapped value for any additions (i.e., {@link
2075	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2076	>	* This is of course only appropriate if it is acceptable to use
2077	>	* the same value for all additions from this view.
2078	>	*
2079	>	* @param mappedValue the mapped value to use for any additions
2080	>	* @return the set view
2081	>	* @throws NullPointerException if the mappedValue is null
2082		*/
2083	<	public ConcurrentHashMap() {
2084	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2083	>	public KeySetView<K,V> keySet(V mappedValue) {
2084	>	if (mappedValue == null)
2085	>	throw new NullPointerException();
2086	>	return new KeySetView<K,V>(this, mappedValue);
2087		}
2088
2089	+	/* ---------------- Special Nodes -------------- */
2090	+
2091		/**
2092	<	* Constructs a new map with the same mappings as the given map.  The
585	<	* map is created with a capacity of twice the number of mappings in
586	<	* the given map or 11 (whichever is greater), and a default load factor.
2092	>	* A node inserted at head of bins during transfer operations.
2093		*/
2094	<	public <A extends K, B extends V> ConcurrentHashMap(Map<A,B> t) {
2095	<	this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
2096	<	11),
2097	<	DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
2098	<	putAll(t);
2094	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2095	>	final Node<K,V>[] nextTable;
2096	>	ForwardingNode(Node<K,V>[] tab) {
2097	>	super(MOVED, null, null, null);
2098	>	this.nextTable = tab;
2099	>	}
2100	>
2101	>	Node<K,V> find(int h, Object k) {
2102	>	Node<K,V> e; int n;
2103	>	Node<K,V>[] tab = nextTable;
2104	>	if (k != null && tab != null && (n = tab.length) > 0 &&
2105	>	(e = tabAt(tab, (n - 1) & h)) != null) {
2106	>	do {
2107	>	int eh; K ek;
2108	>	if ((eh = e.hash) == h &&
2109	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2110	>	return e;
2111	>	if (eh < 0)
2112	>	return e.find(h, k);
2113	>	} while ((e = e.next) != null);
2114	>	}
2115	>	return null;
2116	>	}
2117		}
2118
2119	<	// inherit Map javadoc
2120	<	public boolean isEmpty() {
2121	<	/*
2122	<	* We need to keep track of per-segment modCounts to avoid ABA
2123	<	* problems in which an element in one segment was added and
2124	<	* in another removed during traversal, in which case the
601	<	* table was never actually empty at any point. Note the
602	<	* similar use of modCounts in the size() and containsValue()
603	<	* methods, which are the only other methods also susceptible
604	<	* to ABA problems.
605	<	*/
606	<	int[] mc = new int[segments.length];
607	<	int mcsum = 0;
608	<	for (int i = 0; i < segments.length; ++i) {
609	<	if (segments[i].count != 0)
610	<	return false;
611	<	else
612	<	mcsum += mc[i] = segments[i].modCount;
2119	>	/**
2120	>	* A place-holder node used in computeIfAbsent and compute
2121	>	*/
2122	>	static final class ReservationNode<K,V> extends Node<K,V> {
2123	>	ReservationNode() {
2124	>	super(RESERVED, null, null, null);
2125		}
2126	<	// If mcsum happens to be zero, then we know we got a snapshot
2127	<	// before any modifications at all were made.  This is
2128	<	// probably common enough to bother tracking.
617	<	if (mcsum != 0) {
618	<	for (int i = 0; i < segments.length; ++i) {
619	<	if (segments[i].count != 0 ||
620	<	mc[i] != segments[i].modCount)
621	<	return false;
622	<	}
2126	>
2127	>	Node<K,V> find(int h, Object k) {
2128	>	return null;
2129		}
624	–	return true;
2130		}
2131
2132	<	// inherit Map javadoc
2133	<	public int size() {
2134	<	int[] mc = new int[segments.length];
2135	<	for (;;) {
2136	<	long sum = 0;
2137	<	int mcsum = 0;
2138	<	for (int i = 0; i < segments.length; ++i) {
2139	<	sum += segments[i].count;
2140	<	mcsum += mc[i] = segments[i].modCount;
2141	<	}
2142	<	int check = 0;
2143	<	if (mcsum != 0) {
2144	<	for (int i = 0; i < segments.length; ++i) {
2145	<	check += segments[i].count;
2146	<	if (mc[i] != segments[i].modCount) {
2147	<	check = -1; // force retry
2148	<	break;
2132	>	/* ---------------- Table Initialization and Resizing -------------- */
2133	>
2134	>	/**
2135	>	* Initializes table, using the size recorded in sizeCtl.
2136	>	*/
2137	>	private final Node<K,V>[] initTable() {
2138	>	Node<K,V>[] tab; int sc;
2139	>	while ((tab = table) == null || tab.length == 0) {
2140	>	if ((sc = sizeCtl) < 0)
2141	>	Thread.yield(); // lost initialization race; just spin
2142	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2143	>	try {
2144	>	if ((tab = table) == null || tab.length == 0) {
2145	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2146	>	@SuppressWarnings({"rawtypes","unchecked"})
2147	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2148	>	table = tab = nt;
2149	>	sc = n - (n >>> 2);
2150		}
2151	+	} finally {
2152	+	sizeCtl = sc;
2153		}
2154	+	break;
2155		}
2156	<	if (check == sum) {
2157	<	if (sum > Integer.MAX_VALUE)
2158	<	return Integer.MAX_VALUE;
2159	<	else
2160	<	return (int)sum;
2156	>	}
2157	>	return tab;
2158	>	}
2159	>
2160	>	/**
2161	>	* Adds to count, and if table is too small and not already
2162	>	* resizing, initiates transfer. If already resizing, helps
2163	>	* perform transfer if work is available.  Rechecks occupancy
2164	>	* after a transfer to see if another resize is already needed
2165	>	* because resizings are lagging additions.
2166	>	*
2167	>	* @param x the count to add
2168	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2169	>	*/
2170	>	private final void addCount(long x, int check) {
2171	>	CounterCell[] as; long b, s;
2172	>	if ((as = counterCells) != null ||
2173	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2174	>	CounterCell a; long v; int m;
2175	>	boolean uncontended = true;
2176	>	if (as == null || (m = as.length - 1) < 0 ||
2177	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2178	>	!(uncontended =
2179	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2180	>	fullAddCount(x, uncontended);
2181	>	return;
2182	>	}
2183	>	if (check <= 1)
2184	>	return;
2185	>	s = sumCount();
2186	>	}
2187	>	if (check >= 0) {
2188	>	Node<K,V>[] tab, nt; int sc;
2189	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2190	>	tab.length < MAXIMUM_CAPACITY) {
2191	>	if (sc < 0) {
2192	>	if (sc == -1 || transferIndex <= transferOrigin ||
2193	>	(nt = nextTable) == null)
2194	>	break;
2195	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2196	>	transfer(tab, nt);
2197	>	}
2198	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2199	>	transfer(tab, null);
2200	>	s = sumCount();
2201		}
2202		}
2203		}
2204
2205	+	/**
2206	+	* Helps transfer if a resize is in progress.
2207	+	*/
2208	+	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2209	+	Node<K,V>[] nextTab; int sc;
2210	+	if ((f instanceof ForwardingNode) &&
2211	+	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2212	+	if (nextTab == nextTable && tab == table &&
2213	+	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2214	+	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2215	+	transfer(tab, nextTab);
2216	+	return nextTab;
2217	+	}
2218	+	return table;
2219	+	}
2220
2221		/**
2222	<	* Returns the value to which the specified key is mapped in this table.
2222	>	* Tries to presize table to accommodate the given number of elements.
2223		*
2224	<	* @param   key   a key in the table.
661	<	* @return  the value to which the key is mapped in this table;
662	<	*          <tt>null</tt> if the key is not mapped to any value in
663	<	*          this table.
664	<	* @throws  NullPointerException  if the key is
665	<	*               <tt>null</tt>.
2224	>	* @param size number of elements (doesn't need to be perfectly accurate)
2225		*/
2226	<	public V get(Object key) {
2227	<	int hash = hash(key); // throws NullPointerException if key null
2228	<	return segmentFor(hash).get(key, hash);
2226	>	private final void tryPresize(int size) {
2227	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2228	>	tableSizeFor(size + (size >>> 1) + 1);
2229	>	int sc;
2230	>	while ((sc = sizeCtl) >= 0) {
2231	>	Node<K,V>[] tab = table; int n;
2232	>	if (tab == null || (n = tab.length) == 0) {
2233	>	n = (sc > c) ? sc : c;
2234	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2235	>	try {
2236	>	if (table == tab) {
2237	>	@SuppressWarnings({"rawtypes","unchecked"})
2238	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2239	>	table = nt;
2240	>	sc = n - (n >>> 2);
2241	>	}
2242	>	} finally {
2243	>	sizeCtl = sc;
2244	>	}
2245	>	}
2246	>	}
2247	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2248	>	break;
2249	>	else if (tab == table &&
2250	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2251	>	transfer(tab, null);
2252	>	}
2253		}
2254
2255		/**
2256	<	* Tests if the specified object is a key in this table.
2257	<	*
675	<	* @param   key   possible key.
676	<	* @return  <tt>true</tt> if and only if the specified object
677	<	*          is a key in this table, as determined by the
678	<	*          <tt>equals</tt> method; <tt>false</tt> otherwise.
679	<	* @throws  NullPointerException  if the key is
680	<	*               <tt>null</tt>.
2256	>	* Moves and/or copies the nodes in each bin to new table. See
2257	>	* above for explanation.
2258		*/
2259	<	public boolean containsKey(Object key) {
2260	<	int hash = hash(key); // throws NullPointerException if key null
2261	<	return segmentFor(hash).containsKey(key, hash);
2259	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2260	>	int n = tab.length, stride;
2261	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2262	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2263	>	if (nextTab == null) {            // initiating
2264	>	try {
2265	>	@SuppressWarnings({"rawtypes","unchecked"})
2266	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2267	>	nextTab = nt;
2268	>	} catch (Throwable ex) {      // try to cope with OOME
2269	>	sizeCtl = Integer.MAX_VALUE;
2270	>	return;
2271	>	}
2272	>	nextTable = nextTab;
2273	>	transferOrigin = n;
2274	>	transferIndex = n;
2275	>	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2276	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
2277	>	int nextk = (k > stride) ? k - stride : 0;
2278	>	for (int m = nextk; m < k; ++m)
2279	>	nextTab[m] = rev;
2280	>	for (int m = n + nextk; m < n + k; ++m)
2281	>	nextTab[m] = rev;
2282	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2283	>	}
2284	>	}
2285	>	int nextn = nextTab.length;
2286	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2287	>	boolean advance = true;
2288	>	for (int i = 0, bound = 0;;) {
2289	>	int nextIndex, nextBound, fh; Node<K,V> f;
2290	>	while (advance) {
2291	>	if (--i >= bound)
2292	>	advance = false;
2293	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
2294	>	i = -1;
2295	>	advance = false;
2296	>	}
2297	>	else if (U.compareAndSwapInt
2298	>	(this, TRANSFERINDEX, nextIndex,
2299	>	nextBound = (nextIndex > stride ?
2300	>	nextIndex - stride : 0))) {
2301	>	bound = nextBound;
2302	>	i = nextIndex - 1;
2303	>	advance = false;
2304	>	}
2305	>	}
2306	>	if (i < 0 || i >= n || i + n >= nextn) {
2307	>	for (int sc;;) {
2308	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2309	>	if (sc == -1) {
2310	>	nextTable = null;
2311	>	table = nextTab;
2312	>	sizeCtl = (n << 1) - (n >>> 1);
2313	>	}
2314	>	return;
2315	>	}
2316	>	}
2317	>	}
2318	>	else if ((f = tabAt(tab, i)) == null) {
2319	>	if (casTabAt(tab, i, null, fwd)) {
2320	>	setTabAt(nextTab, i, null);
2321	>	setTabAt(nextTab, i + n, null);
2322	>	advance = true;
2323	>	}
2324	>	}
2325	>	else if ((fh = f.hash) == MOVED)
2326	>	advance = true; // already processed
2327	>	else {
2328	>	synchronized (f) {
2329	>	if (tabAt(tab, i) == f) {
2330	>	Node<K,V> ln, hn;
2331	>	if (fh >= 0) {
2332	>	int runBit = fh & n;
2333	>	Node<K,V> lastRun = f;
2334	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2335	>	int b = p.hash & n;
2336	>	if (b != runBit) {
2337	>	runBit = b;
2338	>	lastRun = p;
2339	>	}
2340	>	}
2341	>	if (runBit == 0) {
2342	>	ln = lastRun;
2343	>	hn = null;
2344	>	}
2345	>	else {
2346	>	hn = lastRun;
2347	>	ln = null;
2348	>	}
2349	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2350	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2351	>	if ((ph & n) == 0)
2352	>	ln = new Node<K,V>(ph, pk, pv, ln);
2353	>	else
2354	>	hn = new Node<K,V>(ph, pk, pv, hn);
2355	>	}
2356	>	}
2357	>	else if (f instanceof TreeBin) {
2358	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2359	>	TreeNode<K,V> lo = null, loTail = null;
2360	>	TreeNode<K,V> hi = null, hiTail = null;
2361	>	int lc = 0, hc = 0;
2362	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2363	>	int h = e.hash;
2364	>	TreeNode<K,V> p = new TreeNode<K,V>
2365	>	(h, e.key, e.val, null, null);
2366	>	if ((h & n) == 0) {
2367	>	if ((p.prev = loTail) == null)
2368	>	lo = p;
2369	>	else
2370	>	loTail.next = p;
2371	>	loTail = p;
2372	>	++lc;
2373	>	}
2374	>	else {
2375	>	if ((p.prev = hiTail) == null)
2376	>	hi = p;
2377	>	else
2378	>	hiTail.next = p;
2379	>	hiTail = p;
2380	>	++hc;
2381	>	}
2382	>	}
2383	>	ln = (lc <= UNTREEIFY_THRESHOLD ?  untreeify(lo) :
2384	>	(hc != 0) ? new TreeBin<K,V>(lo) : t);
2385	>	hn = (hc <= UNTREEIFY_THRESHOLD ? untreeify(hi) :
2386	>	(lc != 0) ? new TreeBin<K,V>(hi) : t);
2387	>	}
2388	>	else
2389	>	ln = hn = null;
2390	>	setTabAt(nextTab, i, ln);
2391	>	setTabAt(nextTab, i + n, hn);
2392	>	setTabAt(tab, i, fwd);
2393	>	advance = true;
2394	>	}
2395	>	}
2396	>	}
2397	>	}
2398		}
2399
2400	+	/* ---------------- Counter support -------------- */
2401	+
2402		/**
2403	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2404	<	* specified value. Note: This method requires a full internal
690	<	* traversal of the hash table, and so is much slower than
691	<	* method <tt>containsKey</tt>.
692	<	*
693	<	* @param value value whose presence in this map is to be tested.
694	<	* @return <tt>true</tt> if this map maps one or more keys to the
695	<	* specified value.
696	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
2403	>	* A padded cell for distributing counts.  Adapted from LongAdder
2404	>	* and Striped64.  See their internal docs for explanation.
2405		*/
2406	<	public boolean containsValue(Object value) {
2407	<	if (value == null)
2408	<	throw new NullPointerException();
2406	>	@sun.misc.Contended static final class CounterCell {
2407	>	volatile long value;
2408	>	CounterCell(long x) { value = x; }
2409	>	}
2410
2411	<	int[] mc = new int[segments.length];
2411	>	final long sumCount() {
2412	>	CounterCell[] as = counterCells; CounterCell a;
2413	>	long sum = baseCount;
2414	>	if (as != null) {
2415	>	for (int i = 0; i < as.length; ++i) {
2416	>	if ((a = as[i]) != null)
2417	>	sum += a.value;
2418	>	}
2419	>	}
2420	>	return sum;
2421	>	}
2422	>
2423	>	// See LongAdder version for explanation
2424	>	private final void fullAddCount(long x, boolean wasUncontended) {
2425	>	int h;
2426	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2427	>	ThreadLocalRandom.localInit();      // force initialization
2428	>	h = ThreadLocalRandom.getProbe();
2429	>	wasUncontended = true;
2430	>	}
2431	>	boolean collide = false;                // True if last slot nonempty
2432		for (;;) {
2433	<	int sum = 0;
2434	<	int mcsum = 0;
2435	<	for (int i = 0; i < segments.length; ++i) {
2436	<	int c = segments[i].count;
2437	<	mcsum += mc[i] = segments[i].modCount;
2438	<	if (segments[i].containsValue(value))
2439	<	return true;
2433	>	CounterCell[] as; CounterCell a; int n; long v;
2434	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2435	>	if ((a = as[(n - 1) & h]) == null) {
2436	>	if (cellsBusy == 0) {            // Try to attach new Cell
2437	>	CounterCell r = new CounterCell(x); // Optimistic create
2438	>	if (cellsBusy == 0 &&
2439	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2440	>	boolean created = false;
2441	>	try {               // Recheck under lock
2442	>	CounterCell[] rs; int m, j;
2443	>	if ((rs = counterCells) != null &&
2444	>	(m = rs.length) > 0 &&
2445	>	rs[j = (m - 1) & h] == null) {
2446	>	rs[j] = r;
2447	>	created = true;
2448	>	}
2449	>	} finally {
2450	>	cellsBusy = 0;
2451	>	}
2452	>	if (created)
2453	>	break;
2454	>	continue;           // Slot is now non-empty
2455	>	}
2456	>	}
2457	>	collide = false;
2458	>	}
2459	>	else if (!wasUncontended)       // CAS already known to fail
2460	>	wasUncontended = true;      // Continue after rehash
2461	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2462	>	break;
2463	>	else if (counterCells != as || n >= NCPU)
2464	>	collide = false;            // At max size or stale
2465	>	else if (!collide)
2466	>	collide = true;
2467	>	else if (cellsBusy == 0 &&
2468	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2469	>	try {
2470	>	if (counterCells == as) {// Expand table unless stale
2471	>	CounterCell[] rs = new CounterCell[n << 1];
2472	>	for (int i = 0; i < n; ++i)
2473	>	rs[i] = as[i];
2474	>	counterCells = rs;
2475	>	}
2476	>	} finally {
2477	>	cellsBusy = 0;
2478	>	}
2479	>	collide = false;
2480	>	continue;                   // Retry with expanded table
2481	>	}
2482	>	h = ThreadLocalRandom.advanceProbe(h);
2483		}
2484	<	boolean cleanSweep = true;
2485	<	if (mcsum != 0) {
2486	<	for (int i = 0; i < segments.length; ++i) {
2487	<	int c = segments[i].count;
2488	<	if (mc[i] != segments[i].modCount) {
2489	<	cleanSweep = false;
2490	<	break;
2484	>	else if (cellsBusy == 0 && counterCells == as &&
2485	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2486	>	boolean init = false;
2487	>	try {                           // Initialize table
2488	>	if (counterCells == as) {
2489	>	CounterCell[] rs = new CounterCell[2];
2490	>	rs[h & 1] = new CounterCell(x);
2491	>	counterCells = rs;
2492	>	init = true;
2493		}
2494	+	} finally {
2495	+	cellsBusy = 0;
2496		}
2497	+	if (init)
2498	+	break;
2499		}
2500	<	if (cleanSweep)
2500	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2501	>	break;                          // Fall back on using base
2502	>	}
2503	>	}
2504	>
2505	>	/* ---------------- Conversion from/to TreeBins -------------- */
2506	>
2507	>	/**
2508	>	* Replaces all linked nodes in bin at given index unless table is
2509	>	* too small, in which case resizes instead.
2510	>	*/
2511	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2512	>	Node<K,V> b; int n, sc;
2513	>	if (tab != null) {
2514	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY &&
2515	>	tab == table && (sc = sizeCtl) >= 0 &&
2516	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2517	>	transfer(tab, null);
2518	>	else if ((b = tabAt(tab, index)) != null) {
2519	>	synchronized(b) {
2520	>	if (tabAt(tab, index) == b) {
2521	>	TreeNode<K,V> hd = null, tl = null;
2522	>	for (Node<K,V> e = b; e != null; e = e.next) {
2523	>	TreeNode<K,V> p =
2524	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2525	>	null, null);
2526	>	if ((p.prev = tl) == null)
2527	>	hd = p;
2528	>	else
2529	>	tl.next = p;
2530	>	tl = p;
2531	>	}
2532	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2533	>	}
2534	>	}
2535	>	}
2536	>	}
2537	>	}
2538	>
2539	>	/**
2540	>	* Returns a list on non-TreeNodes replacing those in given list
2541	>	*/
2542	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2543	>	Node<K,V> hd = null, tl = null;
2544	>	for (Node<K,V> q = b; q != null; q = q.next) {
2545	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2546	>	if (tl == null)
2547	>	hd = p;
2548	>	else
2549	>	tl.next = p;
2550	>	tl = p;
2551	>	}
2552	>	return hd;
2553	>	}
2554	>
2555	>	/* ---------------- TreeNodes -------------- */
2556	>
2557	>	/**
2558	>	* Nodes for use in TreeBins
2559	>	*/
2560	>	static final class TreeNode<K,V> extends Node<K,V> {
2561	>	TreeNode<K,V> parent;  // red-black tree links
2562	>	TreeNode<K,V> left;
2563	>	TreeNode<K,V> right;
2564	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2565	>	boolean red;
2566	>
2567	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2568	>	TreeNode<K,V> parent) {
2569	>	super(hash, key, val, next);
2570	>	this.parent = parent;
2571	>	}
2572	>
2573	>	Node<K,V> find(int h, Object k) {
2574	>	return findTreeNode(h, k, null);
2575	>	}
2576	>
2577	>	/**
2578	>	* Returns the TreeNode (or null if not found) for the given key
2579	>	* starting at given root.
2580	>	*/
2581	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2582	>	if (k == null)
2583	>	return null;
2584	>	TreeNode<K,V> p = this;
2585	>	do  {
2586	>	int ph, dir; K pk; TreeNode<K,V> q;
2587	>	TreeNode<K,V> pl = p.left, pr = p.right;
2588	>	if ((ph = p.hash) > h)
2589	>	p = pl;
2590	>	else if (ph < h)
2591	>	p = pr;
2592	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2593	>	return p;
2594	>	else if (pl == null && pr == null)
2595	>	break;
2596	>	else if ((kc != null || (kc = comparableClassFor(k)) != null) &&
2597	>	(dir = compareComparables(kc, k, pk)) != 0)
2598	>	p = (dir < 0) ? pl : pr;
2599	>	else if (pl == null)
2600	>	p = pr;
2601	>	else if (pr == null || (q = pr.findTreeNode(h, k, kc)) == null)
2602	>	p = pl;
2603	>	else
2604	>	return q;
2605	>	} while (p != null);
2606	>	return null;
2607	>	}
2608	>	}
2609	>
2610	>	/* ---------------- TreeBins -------------- */
2611	>
2612	>	/**
2613	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2614	>	* keys or values, but instead point to list of TreeNodes and
2615	>	* their root. They also maintain a parasitic read-write lock
2616	>	* forcing writers (who hold bin lock) to wait for readers (who do
2617	>	* not) to complete before tree restructuring operations.
2618	>	*/
2619	>	static final class TreeBin<K,V> extends Node<K,V> {
2620	>	TreeNode<K,V> root;
2621	>	volatile TreeNode<K,V> first;
2622	>	volatile Thread waiter;
2623	>	static final int WRITER = 1; // values for lockState
2624	>	static final int WAITER = 2;
2625	>	static final int READER = 4;
2626	>	volatile int lockState;
2627	>
2628	>	/**
2629	>	* Creates bin with initial set of nodes headed by b.
2630	>	*/
2631	>	TreeBin(TreeNode<K,V> b) {
2632	>	super(TREEBIN, null, null, null);
2633	>	first = b;
2634	>	TreeNode<K,V> r = null;
2635	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2636	>	next = (TreeNode<K,V>)x.next;
2637	>	x.left = x.right = null;
2638	>	if (r == null) {
2639	>	x.parent = null;
2640	>	x.red = false;
2641	>	r = x;
2642	>	}
2643	>	else {
2644	>	Object key = x.key;
2645	>	int hash = x.hash;
2646	>	Class<?> kc = null;
2647	>	for (TreeNode<K,V> p = r;;) {
2648	>	int dir, ph;
2649	>	if ((ph = p.hash) > hash)
2650	>	dir = -1;
2651	>	else if (ph < hash)
2652	>	dir = 1;
2653	>	else if ((kc != null ||
2654	>	(kc = comparableClassFor(key)) != null))
2655	>	dir = compareComparables(kc, key, p.key);
2656	>	else
2657	>	dir = 0;
2658	>	TreeNode<K,V> xp = p;
2659	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2660	>	x.parent = xp;
2661	>	if (dir <= 0)
2662	>	xp.left = x;
2663	>	else
2664	>	xp.right = x;
2665	>	r = balanceInsertion(r, x);
2666	>	break;
2667	>	}
2668	>	}
2669	>	}
2670	>	}
2671	>	root = r;
2672	>	}
2673	>
2674	>	/**
2675	>	* Acquires write lock for tree restructuring
2676	>	*/
2677	>	private final void lockRoot() {
2678	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2679	>	contendedLock(); // offload to separate method
2680	>	}
2681	>
2682	>	/**
2683	>	* Releases write lock for tree restructuring
2684	>	*/
2685	>	private final void unlockRoot() {
2686	>	lockState = 0;
2687	>	}
2688	>
2689	>	/**
2690	>	* Possibly blocks awaiting root lock
2691	>	*/
2692	>	private final void contendedLock() {
2693	>	boolean waiting = false;
2694	>	for (int s;;) {
2695	>	if (((s = lockState) & WRITER) == 0) {
2696	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2697	>	if (waiting)
2698	>	waiter = null;
2699	>	return;
2700	>	}
2701	>	}
2702	>	else if ((s | WAITER) == 0) {
2703	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2704	>	waiting = true;
2705	>	waiter = Thread.currentThread();
2706	>	}
2707	>	}
2708	>	else if (waiting)
2709	>	LockSupport.park(this);
2710	>	}
2711	>	}
2712	>
2713	>	/**
2714	>	* Returns matching node or null if none. Tries to search
2715	>	* using tree compareisons from root, but continues linear
2716	>	* search when lock not available.
2717	>	*/
2718	>	final Node<K,V> find(int h, Object k) {
2719	>	if (k != null) {
2720	>	for (Node<K,V> e = first; e != null; e = e.next) {
2721	>	int s; K ek;
2722	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2723	>	if (e.hash == h &&
2724	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2725	>	return e;
2726	>	}
2727	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2728	>	s + READER)) {
2729	>	TreeNode<K,V> r, p;
2730	>	try {
2731	>	p = ((r = root) == null ? null :
2732	>	r.findTreeNode(h, k, null));
2733	>	} finally {
2734	>	Thread w;
2735	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2736	>	(READER|WAITER) && (w = waiter) != null)
2737	>	LockSupport.unpark(w);
2738	>	}
2739	>	return p;
2740	>	}
2741	>	}
2742	>	}
2743	>	return null;
2744	>	}
2745	>
2746	>	/**
2747	>	* Finds or adds a node.
2748	>	* @return null if added
2749	>	*/
2750	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2751	>	TreeNode<K,V> p;
2752	>	if ((p = root) == null) {
2753	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2754	>	return null;
2755	>	}
2756	>	Class<?> kc = null;
2757	>	for (;;) {
2758	>	int dir, ph; K pk; TreeNode<K,V> q, pr;
2759	>	if ((ph = p.hash) > h)
2760	>	dir = -1;
2761	>	else if (ph < h)
2762	>	dir = 1;
2763	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2764	>	return p;
2765	>	else if ((kc == null &&
2766	>	(kc = comparableClassFor(k)) == null) ||
2767	>	(dir = compareComparables(kc, k, pk)) == 0) {
2768	>	if (p.left == null)
2769	>	dir = 1;
2770	>	else if ((pr = p.right) == null ||
2771	>	(q = pr.findTreeNode(h, k, kc)) == null)
2772	>	dir = -1;
2773	>	else
2774	>	return q;
2775	>	}
2776	>	TreeNode<K,V> xp = p;
2777	>	if ((p = (dir < 0) ? p.left : p.right) == null) {
2778	>	TreeNode<K,V> x, f = first;
2779	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2780	>	if (f != null)
2781	>	f.prev = x;
2782	>	if (dir < 0)
2783	>	xp.left = x;
2784	>	else
2785	>	xp.right = x;
2786	>	if (!xp.red)
2787	>	x.red = true;
2788	>	else {
2789	>	lockRoot();
2790	>	try {
2791	>	root = balanceInsertion(root, x);
2792	>	} finally {
2793	>	unlockRoot();
2794	>	}
2795	>	}
2796	>	//                    assert checkInvariants(root);
2797	>	return null;
2798	>	}
2799	>	}
2800	>	}
2801	>
2802	>	/**
2803	>	* Removes the given node, that must be present before this
2804	>	* call.  This is messier than typical red-black deletion code
2805	>	* because we cannot swap the contents of an interior node
2806	>	* with a leaf successor that is pinned by "next" pointers
2807	>	* that are accessible independently of lock. So instead we
2808	>	* swap the tree linkages.
2809	>	*
2810	>	* @return true if now too small so should be untreeified.
2811	>	*/
2812	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2813	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2814	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2815	>	TreeNode<K,V> r, rl;
2816	>	if (pred == null)
2817	>	first = next;
2818	>	else
2819	>	pred.next = next;
2820	>	if (next != null)
2821	>	next.prev = pred;
2822	>	if (first == null) {
2823	>	root = null;
2824	>	return true;
2825	>	}
2826	>	if ((r = root) == null || r.right == null ||
2827	>	(rl = r.left) == null || rl.left == null)
2828	>	return true;
2829	>	lockRoot();
2830	>	try {
2831	>	TreeNode<K,V> replacement;
2832	>	TreeNode<K,V> pl = p.left;
2833	>	TreeNode<K,V> pr = p.right;
2834	>	if (pl != null && pr != null) {
2835	>	TreeNode<K,V> s = pr, sl;
2836	>	while ((sl = s.left) != null) // find successor
2837	>	s = sl;
2838	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2839	>	TreeNode<K,V> sr = s.right;
2840	>	TreeNode<K,V> pp = p.parent;
2841	>	if (s == pr) { // p was s's direct parent
2842	>	p.parent = s;
2843	>	s.right = p;
2844	>	}
2845	>	else {
2846	>	TreeNode<K,V> sp = s.parent;
2847	>	if ((p.parent = sp) != null) {
2848	>	if (s == sp.left)
2849	>	sp.left = p;
2850	>	else
2851	>	sp.right = p;
2852	>	}
2853	>	if ((s.right = pr) != null)
2854	>	pr.parent = s;
2855	>	}
2856	>	p.left = null;
2857	>	if ((p.right = sr) != null)
2858	>	sr.parent = p;
2859	>	if ((s.left = pl) != null)
2860	>	pl.parent = s;
2861	>	if ((s.parent = pp) == null)
2862	>	r = s;
2863	>	else if (p == pp.left)
2864	>	pp.left = s;
2865	>	else
2866	>	pp.right = s;
2867	>	if (sr != null)
2868	>	replacement = sr;
2869	>	else
2870	>	replacement = p;
2871	>	}
2872	>	else if (pl != null)
2873	>	replacement = pl;
2874	>	else if (pr != null)
2875	>	replacement = pr;
2876	>	else
2877	>	replacement = p;
2878	>	if (replacement != p) {
2879	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2880	>	if (pp == null)
2881	>	r = replacement;
2882	>	else if (p == pp.left)
2883	>	pp.left = replacement;
2884	>	else
2885	>	pp.right = replacement;
2886	>	p.left = p.right = p.parent = null;
2887	>	}
2888	>
2889	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2890	>
2891	>	if (p == replacement) {  // detach pointers
2892	>	TreeNode<K,V> pp;
2893	>	if ((pp = p.parent) != null) {
2894	>	if (p == pp.left)
2895	>	pp.left = null;
2896	>	else if (p == pp.right)
2897	>	pp.right = null;
2898	>	p.parent = null;
2899	>	}
2900	>	}
2901	>	} finally {
2902	>	unlockRoot();
2903	>	}
2904	>	//            assert checkInvariants(root);
2905	>	return false;
2906	>	}
2907	>
2908	>	/* ------------------------------------------------------------ */
2909	>	// Red-black tree methods, all adapted from CLR
2910	>
2911	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2912	>	TreeNode<K,V> p) {
2913	>	if (p != null) {
2914	>	TreeNode<K,V> r = p.right, pp, rl;
2915	>	if ((rl = p.right = r.left) != null)
2916	>	rl.parent = p;
2917	>	if ((pp = r.parent = p.parent) == null)
2918	>	(root = r).red = false;
2919	>	else if (pp.left == p)
2920	>	pp.left = r;
2921	>	else
2922	>	pp.right = r;
2923	>	r.left = p;
2924	>	p.parent = r;
2925	>	}
2926	>	return root;
2927	>	}
2928	>
2929	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2930	>	TreeNode<K,V> p) {
2931	>	if (p != null) {
2932	>	TreeNode<K,V> l = p.left, pp, lr;
2933	>	if ((lr = p.left = l.right) != null)
2934	>	lr.parent = p;
2935	>	if ((pp = l.parent = p.parent) == null)
2936	>	(root = l).red = false;
2937	>	else if (pp.right == p)
2938	>	pp.right = l;
2939	>	else
2940	>	pp.left = l;
2941	>	l.right = p;
2942	>	p.parent = l;
2943	>	}
2944	>	return root;
2945	>	}
2946	>
2947	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2948	>	TreeNode<K,V> x) {
2949	>	x.red = true;
2950	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2951	>	if ((xp = x.parent) == null) {
2952	>	x.red = false;
2953	>	return x;
2954	>	}
2955	>	else if (!xp.red || (xpp = xp.parent) == null)
2956	>	return root;
2957	>	if (xp == (xppl = xpp.left)) {
2958	>	if ((xppr = xpp.right) != null && xppr.red) {
2959	>	xppr.red = false;
2960	>	xp.red = false;
2961	>	xpp.red = true;
2962	>	x = xpp;
2963	>	}
2964	>	else {
2965	>	if (x == xp.right) {
2966	>	root = rotateLeft(root, x = xp);
2967	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2968	>	}
2969	>	if (xp != null) {
2970	>	xp.red = false;
2971	>	if (xpp != null) {
2972	>	xpp.red = true;
2973	>	root = rotateRight(root, xpp);
2974	>	}
2975	>	}
2976	>	}
2977	>	}
2978	>	else {
2979	>	if (xppl != null && xppl.red) {
2980	>	xppl.red = false;
2981	>	xp.red = false;
2982	>	xpp.red = true;
2983	>	x = xpp;
2984	>	}
2985	>	else {
2986	>	if (x == xp.left) {
2987	>	root = rotateRight(root, x = xp);
2988	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2989	>	}
2990	>	if (xp != null) {
2991	>	xp.red = false;
2992	>	if (xpp != null) {
2993	>	xpp.red = true;
2994	>	root = rotateLeft(root, xpp);
2995	>	}
2996	>	}
2997	>	}
2998	>	}
2999	>	}
3000	>	}
3001	>
3002	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3003	>	TreeNode<K,V> x) {
3004	>	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3005	>	if (x == null || x == root)
3006	>	return root;
3007	>	else if ((xp = x.parent) == null) {
3008	>	x.red = false;
3009	>	return x;
3010	>	}
3011	>	else if (x.red) {
3012	>	x.red = false;
3013	>	return root;
3014	>	}
3015	>	else if ((xpl = xp.left) == x) {
3016	>	if ((xpr = xp.right) != null && xpr.red) {
3017	>	xpr.red = false;
3018	>	xp.red = true;
3019	>	root = rotateLeft(root, xp);
3020	>	xpr = (xp = x.parent) == null ? null : xp.right;
3021	>	}
3022	>	if (xpr == null)
3023	>	x = xp;
3024	>	else {
3025	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3026	>	if ((sr == null || !sr.red) &&
3027	>	(sl == null || !sl.red)) {
3028	>	xpr.red = true;
3029	>	x = xp;
3030	>	}
3031	>	else {
3032	>	if (sr == null || !sr.red) {
3033	>	if (sl != null)
3034	>	sl.red = false;
3035	>	xpr.red = true;
3036	>	root = rotateRight(root, xpr);
3037	>	xpr = (xp = x.parent) == null ?
3038	>	null : xp.right;
3039	>	}
3040	>	if (xpr != null) {
3041	>	xpr.red = (xp == null) ? false : xp.red;
3042	>	if ((sr = xpr.right) != null)
3043	>	sr.red = false;
3044	>	}
3045	>	if (xp != null) {
3046	>	xp.red = false;
3047	>	root = rotateLeft(root, xp);
3048	>	}
3049	>	x = root;
3050	>	}
3051	>	}
3052	>	}
3053	>	else { // symmetric
3054	>	if (xpl != null && xpl.red) {
3055	>	xpl.red = false;
3056	>	xp.red = true;
3057	>	root = rotateRight(root, xp);
3058	>	xpl = (xp = x.parent) == null ? null : xp.left;
3059	>	}
3060	>	if (xpl == null)
3061	>	x = xp;
3062	>	else {
3063	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3064	>	if ((sl == null || !sl.red) &&
3065	>	(sr == null || !sr.red)) {
3066	>	xpl.red = true;
3067	>	x = xp;
3068	>	}
3069	>	else {
3070	>	if (sl == null || !sl.red) {
3071	>	if (sr != null)
3072	>	sr.red = false;
3073	>	xpl.red = true;
3074	>	root = rotateLeft(root, xpl);
3075	>	xpl = (xp = x.parent) == null ?
3076	>	null : xp.left;
3077	>	}
3078	>	if (xpl != null) {
3079	>	xpl.red = (xp == null) ? false : xp.red;
3080	>	if ((sl = xpl.left) != null)
3081	>	sl.red = false;
3082	>	}
3083	>	if (xp != null) {
3084	>	xp.red = false;
3085	>	root = rotateRight(root, xp);
3086	>	}
3087	>	x = root;
3088	>	}
3089	>	}
3090	>	}
3091	>	}
3092	>	}
3093	>
3094	>	/**
3095	>	* Recursive invariant check
3096	>	*/
3097	>	static <K,V> boolean checkTreeNode(TreeNode<K,V> t) {
3098	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3099	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3100	>	if (tb != null && tb.next != t)
3101	>	return false;
3102	>	if (tn != null && tn.prev != t)
3103		return false;
3104	+	if (tp != null && t != tp.left && t != tp.right)
3105	+	return false;
3106	+	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3107	+	return false;
3108	+	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3109	+	return false;
3110	+	if (t.red && tl != null && tl.red && tr != null && tr.red)
3111	+	return false;
3112	+	if (tl != null && !checkTreeNode(tl))
3113	+	return false;
3114	+	if (tr != null && !checkTreeNode(tr))
3115	+	return false;
3116	+	return true;
3117	+	}
3118	+
3119	+	private static final sun.misc.Unsafe U;
3120	+	private static final long LOCKSTATE;
3121	+	static {
3122	+	try {
3123	+	U = sun.misc.Unsafe.getUnsafe();
3124	+	Class<?> k = TreeBin.class;
3125	+	LOCKSTATE = U.objectFieldOffset
3126	+	(k.getDeclaredField("lockState"));
3127	+	} catch (Exception e) {
3128	+	throw new Error(e);
3129	+	}
3130		}
3131		}
3132
3133	+	/* ----------------Table Traversal -------------- */
3134	+
3135		/**
3136	<	* Legacy method testing if some key maps into the specified value
3137	<	* in this table.  This method is identical in functionality to
3138	<	* {@link #containsValue}, and  exists solely to ensure
3139	<	* full compatibility with class {@link java.util.Hashtable},
3140	<	* which supported this method prior to introduction of the
3141	<	* Java Collections framework.
3136	>	* Encapsulates traversal for methods such as containsValue; also
3137	>	* serves as a base class for other iterators and spliterators.
3138	>	*
3139	>	* Method advance visits once each still-valid node that was
3140	>	* reachable upon iterator construction. It might miss some that
3141	>	* were added to a bin after the bin was visited, which is OK wrt
3142	>	* consistency guarantees. Maintaining this property in the face
3143	>	* of possible ongoing resizes requires a fair amount of
3144	>	* bookkeeping state that is difficult to optimize away amidst
3145	>	* volatile accesses.  Even so, traversal maintains reasonable
3146	>	* throughput.
3147	>	*
3148	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3149	>	* However, if the table has been resized, then all future steps
3150	>	* must traverse both the bin at the current index as well as at
3151	>	* (index + baseSize); and so on for further resizings. To
3152	>	* paranoically cope with potential sharing by users of iterators
3153	>	* across threads, iteration terminates if a bounds checks fails
3154	>	* for a table read.
3155	>	*/
3156	>	static class Traverser<K,V> {
3157	>	Node<K,V>[] tab;        // current table; updated if resized
3158	>	Node<K,V> next;         // the next entry to use
3159	>	int index;              // index of bin to use next
3160	>	int baseIndex;          // current index of initial table
3161	>	int baseLimit;          // index bound for initial table
3162	>	final int baseSize;     // initial table size
3163	>
3164	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3165	>	this.tab = tab;
3166	>	this.baseSize = size;
3167	>	this.baseIndex = this.index = index;
3168	>	this.baseLimit = limit;
3169	>	this.next = null;
3170	>	}
3171
3172	<	* @param      value   a value to search for.
3173	<	* @return     <tt>true</tt> if and only if some key maps to the
3174	<	*             <tt>value</tt> argument in this table as
3175	<	*             determined by the <tt>equals</tt> method;
3176	<	*             <tt>false</tt> otherwise.
3177	<	* @throws  NullPointerException  if the value is <tt>null</tt>.
3172	>	/**
3173	>	* Advances if possible, returning next valid node, or null if none.
3174	>	*/
3175	>	final Node<K,V> advance() {
3176	>	Node<K,V> e;
3177	>	if ((e = next) != null)
3178	>	e = e.next;
3179	>	for (;;) {
3180	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3181	>	if (e != null)
3182	>	return next = e;
3183	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3184	>	(n = t.length) <= (i = index) || i < 0)
3185	>	return next = null;
3186	>	if ((e = tabAt(t, index)) != null && e.key == null) {
3187	>	if (e instanceof ForwardingNode) {
3188	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3189	>	e = null;
3190	>	continue;
3191	>	}
3192	>	else if (e instanceof TreeBin)
3193	>	e = ((TreeBin<K,V>)e).first;
3194	>	else
3195	>	e = null;
3196	>	}
3197	>	if ((index += baseSize) >= n)
3198	>	index = ++baseIndex;    // visit upper slots if present
3199	>	}
3200	>	}
3201	>	}
3202	>
3203	>	/**
3204	>	* Base of key, value, and entry Iterators. Adds fields to
3205	>	* Traverser to support iterator.remove
3206		*/
3207	<	public boolean contains(Object value) {
3208	<	return containsValue(value);
3207	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3208	>	final ConcurrentHashMap<K,V> map;
3209	>	Node<K,V> lastReturned;
3210	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3211	>	ConcurrentHashMap<K,V> map) {
3212	>	super(tab, size, index, limit);
3213	>	this.map = map;
3214	>	advance();
3215	>	}
3216	>
3217	>	public final boolean hasNext() { return next != null; }
3218	>	public final boolean hasMoreElements() { return next != null; }
3219	>
3220	>	public final void remove() {
3221	>	Node<K,V> p;
3222	>	if ((p = lastReturned) == null)
3223	>	throw new IllegalStateException();
3224	>	lastReturned = null;
3225	>	map.replaceNode(p.key, null, null);
3226	>	}
3227	>	}
3228	>
3229	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3230	>	implements Iterator<K>, Enumeration<K> {
3231	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3232	>	ConcurrentHashMap<K,V> map) {
3233	>	super(tab, index, size, limit, map);
3234	>	}
3235	>
3236	>	public final K next() {
3237	>	Node<K,V> p;
3238	>	if ((p = next) == null)
3239	>	throw new NoSuchElementException();
3240	>	K k = p.key;
3241	>	lastReturned = p;
3242	>	advance();
3243	>	return k;
3244	>	}
3245	>
3246	>	public final K nextElement() { return next(); }
3247	>	}
3248	>
3249	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3250	>	implements Iterator<V>, Enumeration<V> {
3251	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3252	>	ConcurrentHashMap<K,V> map) {
3253	>	super(tab, index, size, limit, map);
3254	>	}
3255	>
3256	>	public final V next() {
3257	>	Node<K,V> p;
3258	>	if ((p = next) == null)
3259	>	throw new NoSuchElementException();
3260	>	V v = p.val;
3261	>	lastReturned = p;
3262	>	advance();
3263	>	return v;
3264	>	}
3265	>
3266	>	public final V nextElement() { return next(); }
3267	>	}
3268	>
3269	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3270	>	implements Iterator<Map.Entry<K,V>> {
3271	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3272	>	ConcurrentHashMap<K,V> map) {
3273	>	super(tab, index, size, limit, map);
3274	>	}
3275	>
3276	>	public final Map.Entry<K,V> next() {
3277	>	Node<K,V> p;
3278	>	if ((p = next) == null)
3279	>	throw new NoSuchElementException();
3280	>	K k = p.key;
3281	>	V v = p.val;
3282	>	lastReturned = p;
3283	>	advance();
3284	>	return new MapEntry<K,V>(k, v, map);
3285	>	}
3286	>	}
3287	>
3288	>	/**
3289	>	* Exported Entry for EntryIterator
3290	>	*/
3291	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3292	>	final K key; // non-null
3293	>	V val;       // non-null
3294	>	final ConcurrentHashMap<K,V> map;
3295	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3296	>	this.key = key;
3297	>	this.val = val;
3298	>	this.map = map;
3299	>	}
3300	>	public K getKey()        { return key; }
3301	>	public V getValue()      { return val; }
3302	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3303	>	public String toString() { return key + "=" + val; }
3304	>
3305	>	public boolean equals(Object o) {
3306	>	Object k, v; Map.Entry<?,?> e;
3307	>	return ((o instanceof Map.Entry) &&
3308	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3309	>	(v = e.getValue()) != null &&
3310	>	(k == key || k.equals(key)) &&
3311	>	(v == val || v.equals(val)));
3312	>	}
3313	>
3314	>	/**
3315	>	* Sets our entry's value and writes through to the map. The
3316	>	* value to return is somewhat arbitrary here. Since we do not
3317	>	* necessarily track asynchronous changes, the most recent
3318	>	* "previous" value could be different from what we return (or
3319	>	* could even have been removed, in which case the put will
3320	>	* re-establish). We do not and cannot guarantee more.
3321	>	*/
3322	>	public V setValue(V value) {
3323	>	if (value == null) throw new NullPointerException();
3324	>	V v = val;
3325	>	val = value;
3326	>	map.put(key, value);
3327	>	return v;
3328	>	}
3329	>	}
3330	>
3331	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3332	>	implements Spliterator<K> {
3333	>	long est;               // size estimate
3334	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3335	>	long est) {
3336	>	super(tab, size, index, limit);
3337	>	this.est = est;
3338	>	}
3339	>
3340	>	public Spliterator<K> trySplit() {
3341	>	int i, f, h;
3342	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3343	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3344	>	f, est >>>= 1);
3345	>	}
3346	>
3347	>	public void forEachRemaining(Consumer<? super K> action) {
3348	>	if (action == null) throw new NullPointerException();
3349	>	for (Node<K,V> p; (p = advance()) != null;)
3350	>	action.accept(p.key);
3351	>	}
3352	>
3353	>	public boolean tryAdvance(Consumer<? super K> action) {
3354	>	if (action == null) throw new NullPointerException();
3355	>	Node<K,V> p;
3356	>	if ((p = advance()) == null)
3357	>	return false;
3358	>	action.accept(p.key);
3359	>	return true;
3360	>	}
3361	>
3362	>	public long estimateSize() { return est; }
3363	>
3364	>	public int characteristics() {
3365	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3366	>	Spliterator.NONNULL;
3367	>	}
3368	>	}
3369	>
3370	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3371	>	implements Spliterator<V> {
3372	>	long est;               // size estimate
3373	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3374	>	long est) {
3375	>	super(tab, size, index, limit);
3376	>	this.est = est;
3377	>	}
3378	>
3379	>	public Spliterator<V> trySplit() {
3380	>	int i, f, h;
3381	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3382	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3383	>	f, est >>>= 1);
3384	>	}
3385	>
3386	>	public void forEachRemaining(Consumer<? super V> action) {
3387	>	if (action == null) throw new NullPointerException();
3388	>	for (Node<K,V> p; (p = advance()) != null;)
3389	>	action.accept(p.val);
3390	>	}
3391	>
3392	>	public boolean tryAdvance(Consumer<? super V> action) {
3393	>	if (action == null) throw new NullPointerException();
3394	>	Node<K,V> p;
3395	>	if ((p = advance()) == null)
3396	>	return false;
3397	>	action.accept(p.val);
3398	>	return true;
3399	>	}
3400	>
3401	>	public long estimateSize() { return est; }
3402	>
3403	>	public int characteristics() {
3404	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3405	>	}
3406	>	}
3407	>
3408	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3409	>	implements Spliterator<Map.Entry<K,V>> {
3410	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3411	>	long est;               // size estimate
3412	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3413	>	long est, ConcurrentHashMap<K,V> map) {
3414	>	super(tab, size, index, limit);
3415	>	this.map = map;
3416	>	this.est = est;
3417	>	}
3418	>
3419	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3420	>	int i, f, h;
3421	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3422	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3423	>	f, est >>>= 1, map);
3424	>	}
3425	>
3426	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3427	>	if (action == null) throw new NullPointerException();
3428	>	for (Node<K,V> p; (p = advance()) != null; )
3429	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3430	>	}
3431	>
3432	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3433	>	if (action == null) throw new NullPointerException();
3434	>	Node<K,V> p;
3435	>	if ((p = advance()) == null)
3436	>	return false;
3437	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3438	>	return true;
3439	>	}
3440	>
3441	>	public long estimateSize() { return est; }
3442	>
3443	>	public int characteristics() {
3444	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3445	>	Spliterator.NONNULL;
3446	>	}
3447	>	}
3448	>
3449	>	// Parallel bulk operations
3450	>
3451	>	/**
3452	>	* Computes initial batch value for bulk tasks. The returned value
3453	>	* is approximately exp2 of the number of times (minus one) to
3454	>	* split task by two before executing leaf action. This value is
3455	>	* faster to compute and more convenient to use as a guide to
3456	>	* splitting than is the depth, since it is used while dividing by
3457	>	* two anyway.
3458	>	*/
3459	>	final int batchFor(long b) {
3460	>	long n;
3461	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3462	>	return 0;
3463	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3464	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3465		}
3466
3467		/**
3468	<	* Maps the specified <tt>key</tt> to the specified
748	<	* <tt>value</tt> in this table. Neither the key nor the
749	<	* value can be <tt>null</tt>. <p>
3468	>	* Performs the given action for each (key, value).
3469		*
3470	<	* The value can be retrieved by calling the <tt>get</tt> method
3471	<	* with a key that is equal to the original key.
3470	>	* @param parallelismThreshold the (estimated) number of elements
3471	>	* needed for this operation to be executed in parallel
3472	>	* @param action the action
3473	>	* @since 1.8
3474	>	*/
3475	>	public void forEach(long parallelismThreshold,
3476	>	BiConsumer<? super K,? super V> action) {
3477	>	if (action == null) throw new NullPointerException();
3478	>	new ForEachMappingTask<K,V>
3479	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3480	>	action).invoke();
3481	>	}
3482	>
3483	>	/**
3484	>	* Performs the given action for each non-null transformation
3485	>	* of each (key, value).
3486		*
3487	<	* @param      key     the table key.
3488	<	* @param      value   the value.
3489	<	* @return     the previous value of the specified key in this table,
3490	<	*             or <tt>null</tt> if it did not have one.
3491	<	* @throws  NullPointerException  if the key or value is
3492	<	*               <tt>null</tt>.
3487	>	* @param parallelismThreshold the (estimated) number of elements
3488	>	* needed for this operation to be executed in parallel
3489	>	* @param transformer a function returning the transformation
3490	>	* for an element, or null if there is no transformation (in
3491	>	* which case the action is not applied)
3492	>	* @param action the action
3493	>	* @since 1.8
3494		*/
3495	<	public V put(K key, V value) {
3496	<	if (value == null)
3495	>	public <U> void forEach(long parallelismThreshold,
3496	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3497	>	Consumer<? super U> action) {
3498	>	if (transformer == null || action == null)
3499		throw new NullPointerException();
3500	<	int hash = hash(key);
3501	<	return segmentFor(hash).put(key, hash, value, false);
3500	>	new ForEachTransformedMappingTask<K,V,U>
3501	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3502	>	transformer, action).invoke();
3503		}
3504
3505		/**
3506	<	* If the specified key is not already associated
3507	<	* with a value, associate it with the given value.
3508	<	* This is equivalent to
3509	<	* <pre>
3510	<	*   if (!map.containsKey(key))
774	<	*      return map.put(key, value);
775	<	*   else
776	<	*      return map.get(key);
777	<	* </pre>
778	<	* Except that the action is performed atomically.
779	<	* @param key key with which the specified value is to be associated.
780	<	* @param value value to be associated with the specified key.
781	<	* @return previous value associated with specified key, or <tt>null</tt>
782	<	*         if there was no mapping for key.  A <tt>null</tt> return can
783	<	*         also indicate that the map previously associated <tt>null</tt>
784	<	*         with the specified key, if the implementation supports
785	<	*         <tt>null</tt> values.
786	<	*
787	<	* @throws UnsupportedOperationException if the <tt>put</tt> operation is
788	<	*            not supported by this map.
789	<	* @throws ClassCastException if the class of the specified key or value
790	<	*            prevents it from being stored in this map.
791	<	* @throws NullPointerException if the specified key or value is
792	<	*            <tt>null</tt>.
3506	>	* Returns a non-null result from applying the given search
3507	>	* function on each (key, value), or null if none.  Upon
3508	>	* success, further element processing is suppressed and the
3509	>	* results of any other parallel invocations of the search
3510	>	* function are ignored.
3511		*
3512	<	**/
3513	<	public V putIfAbsent(K key, V value) {
3514	<	if (value == null)
3512	>	* @param parallelismThreshold the (estimated) number of elements
3513	>	* needed for this operation to be executed in parallel
3514	>	* @param searchFunction a function returning a non-null
3515	>	* result on success, else null
3516	>	* @return a non-null result from applying the given search
3517	>	* function on each (key, value), or null if none
3518	>	* @since 1.8
3519	>	*/
3520	>	public <U> U search(long parallelismThreshold,
3521	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3522	>	if (searchFunction == null) throw new NullPointerException();
3523	>	return new SearchMappingsTask<K,V,U>
3524	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3525	>	searchFunction, new AtomicReference<U>()).invoke();
3526	>	}
3527	>
3528	>	/**
3529	>	* Returns the result of accumulating the given transformation
3530	>	* of all (key, value) pairs using the given reducer to
3531	>	* combine values, or null if none.
3532	>	*
3533	>	* @param parallelismThreshold the (estimated) number of elements
3534	>	* needed for this operation to be executed in parallel
3535	>	* @param transformer a function returning the transformation
3536	>	* for an element, or null if there is no transformation (in
3537	>	* which case it is not combined)
3538	>	* @param reducer a commutative associative combining function
3539	>	* @return the result of accumulating the given transformation
3540	>	* of all (key, value) pairs
3541	>	* @since 1.8
3542	>	*/
3543	>	public <U> U reduce(long parallelismThreshold,
3544	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3545	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3546	>	if (transformer == null || reducer == null)
3547		throw new NullPointerException();
3548	<	int hash = hash(key);
3549	<	return segmentFor(hash).put(key, hash, value, true);
3548	>	return new MapReduceMappingsTask<K,V,U>
3549	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3550	>	null, transformer, reducer).invoke();
3551		}
3552
3553	+	/**
3554	+	* Returns the result of accumulating the given transformation
3555	+	* of all (key, value) pairs using the given reducer to
3556	+	* combine values, and the given basis as an identity value.
3557	+	*
3558	+	* @param parallelismThreshold the (estimated) number of elements
3559	+	* needed for this operation to be executed in parallel
3560	+	* @param transformer a function returning the transformation
3561	+	* for an element
3562	+	* @param basis the identity (initial default value) for the reduction
3563	+	* @param reducer a commutative associative combining function
3564	+	* @return the result of accumulating the given transformation
3565	+	* of all (key, value) pairs
3566	+	* @since 1.8
3567	+	*/
3568	+	public double reduceToDoubleIn(long parallelismThreshold,
3569	+	ToDoubleBiFunction<? super K, ? super V> transformer,
3570	+	double basis,
3571	+	DoubleBinaryOperator reducer) {
3572	+	if (transformer == null || reducer == null)
3573	+	throw new NullPointerException();
3574	+	return new MapReduceMappingsToDoubleTask<K,V>
3575	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3576	+	null, transformer, basis, reducer).invoke();
3577	+	}
3578
3579		/**
3580	<	* Copies all of the mappings from the specified map to this one.
3580	>	* Returns the result of accumulating the given transformation
3581	>	* of all (key, value) pairs using the given reducer to
3582	>	* combine values, and the given basis as an identity value.
3583		*
3584	<	* These mappings replace any mappings that this map had for any of the
3585	<	* keys currently in the specified Map.
3584	>	* @param parallelismThreshold the (estimated) number of elements
3585	>	* needed for this operation to be executed in parallel
3586	>	* @param transformer a function returning the transformation
3587	>	* for an element
3588	>	* @param basis the identity (initial default value) for the reduction
3589	>	* @param reducer a commutative associative combining function
3590	>	* @return the result of accumulating the given transformation
3591	>	* of all (key, value) pairs
3592	>	* @since 1.8
3593	>	*/
3594	>	public long reduceToLong(long parallelismThreshold,
3595	>	ToLongBiFunction<? super K, ? super V> transformer,
3596	>	long basis,
3597	>	LongBinaryOperator reducer) {
3598	>	if (transformer == null || reducer == null)
3599	>	throw new NullPointerException();
3600	>	return new MapReduceMappingsToLongTask<K,V>
3601	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3602	>	null, transformer, basis, reducer).invoke();
3603	>	}
3604	>
3605	>	/**
3606	>	* Returns the result of accumulating the given transformation
3607	>	* of all (key, value) pairs using the given reducer to
3608	>	* combine values, and the given basis as an identity value.
3609		*
3610	<	* @param t Mappings to be stored in this map.
3610	>	* @param parallelismThreshold the (estimated) number of elements
3611	>	* needed for this operation to be executed in parallel
3612	>	* @param transformer a function returning the transformation
3613	>	* for an element
3614	>	* @param basis the identity (initial default value) for the reduction
3615	>	* @param reducer a commutative associative combining function
3616	>	* @return the result of accumulating the given transformation
3617	>	* of all (key, value) pairs
3618	>	* @since 1.8
3619		*/
3620	<	public void putAll(Map<? extends K, ? extends V> t) {
3621	<	for (Iterator<Map.Entry<? extends K, ? extends V>> it = (Iterator<Map.Entry<? extends K, ? extends V>>) t.entrySet().iterator(); it.hasNext(); ) {
3622	<	Entry<? extends K, ? extends V> e = it.next();
3623	<	put(e.getKey(), e.getValue());
3624	<	}
3620	>	public int reduceToInt(long parallelismThreshold,
3621	>	ToIntBiFunction<? super K, ? super V> transformer,
3622	>	int basis,
3623	>	IntBinaryOperator reducer) {
3624	>	if (transformer == null || reducer == null)
3625	>	throw new NullPointerException();
3626	>	return new MapReduceMappingsToIntTask<K,V>
3627	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3628	>	null, transformer, basis, reducer).invoke();
3629		}
3630
3631		/**
3632	<	* Removes the key (and its corresponding value) from this
820	<	* table. This method does nothing if the key is not in the table.
3632	>	* Performs the given action for each key.
3633		*
3634	<	* @param   key   the key that needs to be removed.
3635	<	* @return  the value to which the key had been mapped in this table,
3636	<	*          or <tt>null</tt> if the key did not have a mapping.
3637	<	* @throws  NullPointerException  if the key is
826	<	*               <tt>null</tt>.
3634	>	* @param parallelismThreshold the (estimated) number of elements
3635	>	* needed for this operation to be executed in parallel
3636	>	* @param action the action
3637	>	* @since 1.8
3638		*/
3639	<	public V remove(Object key) {
3640	<	int hash = hash(key);
3641	<	return segmentFor(hash).remove(key, hash, null);
3639	>	public void forEachKey(long parallelismThreshold,
3640	>	Consumer<? super K> action) {
3641	>	if (action == null) throw new NullPointerException();
3642	>	new ForEachKeyTask<K,V>
3643	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3644	>	action).invoke();
3645		}
3646
3647		/**
3648	<	* Remove entry for key only if currently mapped to given value.
3649	<	* Acts as
3650	<	* <pre>
3651	<	*  if (map.get(key).equals(value)) {
3652	<	*     map.remove(key);
3653	<	*     return true;
3654	<	* } else return false;
3655	<	* </pre>
3656	<	* except that the action is performed atomically.
3657	<	* @param key key with which the specified value is associated.
844	<	* @param value value associated with the specified key.
845	<	* @return true if the value was removed
846	<	* @throws NullPointerException if the specified key is
847	<	*            <tt>null</tt>.
3648	>	* Performs the given action for each non-null transformation
3649	>	* of each key.
3650	>	*
3651	>	* @param parallelismThreshold the (estimated) number of elements
3652	>	* needed for this operation to be executed in parallel
3653	>	* @param transformer a function returning the transformation
3654	>	* for an element, or null if there is no transformation (in
3655	>	* which case the action is not applied)
3656	>	* @param action the action
3657	>	* @since 1.8
3658		*/
3659	<	public boolean remove(Object key, Object value) {
3660	<	int hash = hash(key);
3661	<	return segmentFor(hash).remove(key, hash, value) != null;
3659	>	public <U> void forEachKey(long parallelismThreshold,
3660	>	Function<? super K, ? extends U> transformer,
3661	>	Consumer<? super U> action) {
3662	>	if (transformer == null || action == null)
3663	>	throw new NullPointerException();
3664	>	new ForEachTransformedKeyTask<K,V,U>
3665	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3666	>	transformer, action).invoke();
3667	>	}
3668	>
3669	>	/**
3670	>	* Returns a non-null result from applying the given search
3671	>	* function on each key, or null if none. Upon success,
3672	>	* further element processing is suppressed and the results of
3673	>	* any other parallel invocations of the search function are
3674	>	* ignored.
3675	>	*
3676	>	* @param parallelismThreshold the (estimated) number of elements
3677	>	* needed for this operation to be executed in parallel
3678	>	* @param searchFunction a function returning a non-null
3679	>	* result on success, else null
3680	>	* @return a non-null result from applying the given search
3681	>	* function on each key, or null if none
3682	>	* @since 1.8
3683	>	*/
3684	>	public <U> U searchKeys(long parallelismThreshold,
3685	>	Function<? super K, ? extends U> searchFunction) {
3686	>	if (searchFunction == null) throw new NullPointerException();
3687	>	return new SearchKeysTask<K,V,U>
3688	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3689	>	searchFunction, new AtomicReference<U>()).invoke();
3690		}
3691
3692	+	/**
3693	+	* Returns the result of accumulating all keys using the given
3694	+	* reducer to combine values, or null if none.
3695	+	*
3696	+	* @param parallelismThreshold the (estimated) number of elements
3697	+	* needed for this operation to be executed in parallel
3698	+	* @param reducer a commutative associative combining function
3699	+	* @return the result of accumulating all keys using the given
3700	+	* reducer to combine values, or null if none
3701	+	* @since 1.8
3702	+	*/
3703	+	public K reduceKeys(long parallelismThreshold,
3704	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
3705	+	if (reducer == null) throw new NullPointerException();
3706	+	return new ReduceKeysTask<K,V>
3707	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3708	+	null, reducer).invoke();
3709	+	}
3710
3711		/**
3712	<	* Replace entry for key only if currently mapped to given value.
3713	<	* Acts as
3714	<	* <pre>
3715	<	*  if (map.get(key).equals(oldValue)) {
3716	<	*     map.put(key, newValue);
3717	<	*     return true;
3718	<	* } else return false;
3719	<	* </pre>
3720	<	* except that the action is performed atomically.
3721	<	* @param key key with which the specified value is associated.
3722	<	* @param oldValue value expected to be associated with the specified key.
3723	<	* @param newValue value to be associated with the specified key.
3724	<	* @return true if the value was replaced
869	<	* @throws NullPointerException if the specified key or values are
870	<	* <tt>null</tt>.
3712	>	* Returns the result of accumulating the given transformation
3713	>	* of all keys using the given reducer to combine values, or
3714	>	* null if none.
3715	>	*
3716	>	* @param parallelismThreshold the (estimated) number of elements
3717	>	* needed for this operation to be executed in parallel
3718	>	* @param transformer a function returning the transformation
3719	>	* for an element, or null if there is no transformation (in
3720	>	* which case it is not combined)
3721	>	* @param reducer a commutative associative combining function
3722	>	* @return the result of accumulating the given transformation
3723	>	* of all keys
3724	>	* @since 1.8
3725		*/
3726	<	public boolean replace(K key, V oldValue, V newValue) {
3727	<	if (oldValue == null || newValue == null)
3726	>	public <U> U reduceKeys(long parallelismThreshold,
3727	>	Function<? super K, ? extends U> transformer,
3728	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3729	>	if (transformer == null || reducer == null)
3730	>	throw new NullPointerException();
3731	>	return new MapReduceKeysTask<K,V,U>
3732	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3733	>	null, transformer, reducer).invoke();
3734	>	}
3735	>
3736	>	/**
3737	>	* Returns the result of accumulating the given transformation
3738	>	* of all keys using the given reducer to combine values, and
3739	>	* the given basis as an identity value.
3740	>	*
3741	>	* @param parallelismThreshold the (estimated) number of elements
3742	>	* needed for this operation to be executed in parallel
3743	>	* @param transformer a function returning the transformation
3744	>	* for an element
3745	>	* @param basis the identity (initial default value) for the reduction
3746	>	* @param reducer a commutative associative combining function
3747	>	* @return the result of accumulating the given transformation
3748	>	* of all keys
3749	>	* @since 1.8
3750	>	*/
3751	>	public double reduceKeysToDouble(long parallelismThreshold,
3752	>	ToDoubleFunction<? super K> transformer,
3753	>	double basis,
3754	>	DoubleBinaryOperator reducer) {
3755	>	if (transformer == null || reducer == null)
3756		throw new NullPointerException();
3757	<	int hash = hash(key);
3758	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
3757	>	return new MapReduceKeysToDoubleTask<K,V>
3758	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3759	>	null, transformer, basis, reducer).invoke();
3760		}
3761
3762		/**
3763	<	* Replace entry for key only if currently mapped to some value.
3764	<	* Acts as
3765	<	* <pre>
3766	<	*  if ((map.containsKey(key)) {
3767	<	*     return map.put(key, value);
3768	<	* } else return null;
3769	<	* </pre>
3770	<	* except that the action is performed atomically.
3771	<	* @param key key with which the specified value is associated.
3772	<	* @param value value to be associated with the specified key.
3773	<	* @return previous value associated with specified key, or <tt>null</tt>
3774	<	*         if there was no mapping for key.
3775	<	* @throws NullPointerException if the specified key or value is
893	<	*            <tt>null</tt>.
3763	>	* Returns the result of accumulating the given transformation
3764	>	* of all keys using the given reducer to combine values, and
3765	>	* the given basis as an identity value.
3766	>	*
3767	>	* @param parallelismThreshold the (estimated) number of elements
3768	>	* needed for this operation to be executed in parallel
3769	>	* @param transformer a function returning the transformation
3770	>	* for an element
3771	>	* @param basis the identity (initial default value) for the reduction
3772	>	* @param reducer a commutative associative combining function
3773	>	* @return the result of accumulating the given transformation
3774	>	* of all keys
3775	>	* @since 1.8
3776		*/
3777	<	public V replace(K key, V value) {
3778	<	if (value == null)
3777	>	public long reduceKeysToLong(long parallelismThreshold,
3778	>	ToLongFunction<? super K> transformer,
3779	>	long basis,
3780	>	LongBinaryOperator reducer) {
3781	>	if (transformer == null || reducer == null)
3782		throw new NullPointerException();
3783	<	int hash = hash(key);
3784	<	return segmentFor(hash).replace(key, hash, value);
3783	>	return new MapReduceKeysToLongTask<K,V>
3784	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3785	>	null, transformer, basis, reducer).invoke();
3786		}
3787
3788	+	/**
3789	+	* Returns the result of accumulating the given transformation
3790	+	* of all keys using the given reducer to combine values, and
3791	+	* the given basis as an identity value.
3792	+	*
3793	+	* @param parallelismThreshold the (estimated) number of elements
3794	+	* needed for this operation to be executed in parallel
3795	+	* @param transformer a function returning the transformation
3796	+	* for an element
3797	+	* @param basis the identity (initial default value) for the reduction
3798	+	* @param reducer a commutative associative combining function
3799	+	* @return the result of accumulating the given transformation
3800	+	* of all keys
3801	+	* @since 1.8
3802	+	*/
3803	+	public int reduceKeysToInt(long parallelismThreshold,
3804	+	ToIntFunction<? super K> transformer,
3805	+	int basis,
3806	+	IntBinaryOperator reducer) {
3807	+	if (transformer == null || reducer == null)
3808	+	throw new NullPointerException();
3809	+	return new MapReduceKeysToIntTask<K,V>
3810	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3811	+	null, transformer, basis, reducer).invoke();
3812	+	}
3813
3814		/**
3815	<	* Removes all mappings from this map.
3815	>	* Performs the given action for each value.
3816	>	*
3817	>	* @param parallelismThreshold the (estimated) number of elements
3818	>	* needed for this operation to be executed in parallel
3819	>	* @param action the action
3820	>	* @since 1.8
3821		*/
3822	<	public void clear() {
3823	<	for (int i = 0; i < segments.length; ++i)
3824	<	segments[i].clear();
3822	>	public void forEachValue(long parallelismThreshold,
3823	>	Consumer<? super V> action) {
3824	>	if (action == null)
3825	>	throw new NullPointerException();
3826	>	new ForEachValueTask<K,V>
3827	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3828	>	action).invoke();
3829		}
3830
3831	+	/**
3832	+	* Performs the given action for each non-null transformation
3833	+	* of each value.
3834	+	*
3835	+	* @param parallelismThreshold the (estimated) number of elements
3836	+	* needed for this operation to be executed in parallel
3837	+	* @param transformer a function returning the transformation
3838	+	* for an element, or null if there is no transformation (in
3839	+	* which case the action is not applied)
3840	+	* @param action the action
3841	+	* @since 1.8
3842	+	*/
3843	+	public <U> void forEachValue(long parallelismThreshold,
3844	+	Function<? super V, ? extends U> transformer,
3845	+	Consumer<? super U> action) {
3846	+	if (transformer == null || action == null)
3847	+	throw new NullPointerException();
3848	+	new ForEachTransformedValueTask<K,V,U>
3849	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3850	+	transformer, action).invoke();
3851	+	}
3852
3853		/**
3854	<	* Returns a shallow copy of this
3855	<	* <tt>ConcurrentHashMap</tt> instance: the keys and
3856	<	* values themselves are not cloned.
3854	>	* Returns a non-null result from applying the given search
3855	>	* function on each value, or null if none.  Upon success,
3856	>	* further element processing is suppressed and the results of
3857	>	* any other parallel invocations of the search function are
3858	>	* ignored.
3859		*
3860	<	* @return a shallow copy of this map.
3860	>	* @param parallelismThreshold the (estimated) number of elements
3861	>	* needed for this operation to be executed in parallel
3862	>	* @param searchFunction a function returning a non-null
3863	>	* result on success, else null
3864	>	* @return a non-null result from applying the given search
3865	>	* function on each value, or null if none
3866	>	* @since 1.8
3867		*/
3868	<	public Object clone() {
3869	<	// We cannot call super.clone, since it would share final
3870	<	// segments array, and there's no way to reassign finals.
3868	>	public <U> U searchValues(long parallelismThreshold,
3869	>	Function<? super V, ? extends U> searchFunction) {
3870	>	if (searchFunction == null) throw new NullPointerException();
3871	>	return new SearchValuesTask<K,V,U>
3872	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3873	>	searchFunction, new AtomicReference<U>()).invoke();
3874	>	}
3875
3876	<	float lf = segments[0].loadFactor;
3877	<	int segs = segments.length;
3878	<	int cap = (int)(size() / lf);
3879	<	if (cap < segs) cap = segs;
3880	<	ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
3881	<	t.putAll(this);
3882	<	return t;
3876	>	/**
3877	>	* Returns the result of accumulating all values using the
3878	>	* given reducer to combine values, or null if none.
3879	>	*
3880	>	* @param parallelismThreshold the (estimated) number of elements
3881	>	* needed for this operation to be executed in parallel
3882	>	* @param reducer a commutative associative combining function
3883	>	* @return the result of accumulating all values
3884	>	* @since 1.8
3885	>	*/
3886	>	public V reduceValues(long parallelismThreshold,
3887	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
3888	>	if (reducer == null) throw new NullPointerException();
3889	>	return new ReduceValuesTask<K,V>
3890	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3891	>	null, reducer).invoke();
3892		}
3893
3894		/**
3895	<	* Returns a set view of the keys contained in this map.  The set is
3896	<	* backed by the map, so changes to the map are reflected in the set, and
3897	<	* vice-versa.  The set supports element removal, which removes the
936	<	* corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
937	<	* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
938	<	* <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
939	<	* <tt>addAll</tt> operations.
940	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
941	<	* will never throw {@link java.util.ConcurrentModificationException},
942	<	* and guarantees to traverse elements as they existed upon
943	<	* construction of the iterator, and may (but is not guaranteed to)
944	<	* reflect any modifications subsequent to construction.
3895	>	* Returns the result of accumulating the given transformation
3896	>	* of all values using the given reducer to combine values, or
3897	>	* null if none.
3898		*
3899	<	* @return a set view of the keys contained in this map.
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, or null if there is no transformation (in
3903	>	* which case it is not combined)
3904	>	* @param reducer a commutative associative combining function
3905	>	* @return the result of accumulating the given transformation
3906	>	* of all values
3907	>	* @since 1.8
3908		*/
3909	<	public Set<K> keySet() {
3910	<	Set<K> ks = keySet;
3911	<	return (ks != null) ? ks : (keySet = new KeySet());
3909	>	public <U> U reduceValues(long parallelismThreshold,
3910	>	Function<? super V, ? extends U> transformer,
3911	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3912	>	if (transformer == null || reducer == null)
3913	>	throw new NullPointerException();
3914	>	return new MapReduceValuesTask<K,V,U>
3915	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3916	>	null, transformer, reducer).invoke();
3917		}
3918
3919	+	/**
3920	+	* Returns the result of accumulating the given transformation
3921	+	* of all values using the given reducer to combine values,
3922	+	* and the given basis as an identity value.
3923	+	*
3924	+	* @param parallelismThreshold the (estimated) number of elements
3925	+	* needed for this operation to be executed in parallel
3926	+	* @param transformer a function returning the transformation
3927	+	* for an element
3928	+	* @param basis the identity (initial default value) for the reduction
3929	+	* @param reducer a commutative associative combining function
3930	+	* @return the result of accumulating the given transformation
3931	+	* of all values
3932	+	* @since 1.8
3933	+	*/
3934	+	public double reduceValuesToDouble(long parallelismThreshold,
3935	+	ToDoubleFunction<? super V> transformer,
3936	+	double basis,
3937	+	DoubleBinaryOperator reducer) {
3938	+	if (transformer == null || reducer == null)
3939	+	throw new NullPointerException();
3940	+	return new MapReduceValuesToDoubleTask<K,V>
3941	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3942	+	null, transformer, basis, reducer).invoke();
3943	+	}
3944
3945		/**
3946	<	* Returns a collection view of the values contained in this map.  The
3947	<	* collection is backed by the map, so changes to the map are reflected in
3948	<	* the collection, and vice-versa.  The collection supports element
958	<	* removal, which removes the corresponding mapping from this map, via the
959	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
960	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
961	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
962	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
963	<	* will never throw {@link java.util.ConcurrentModificationException},
964	<	* and guarantees to traverse elements as they existed upon
965	<	* construction of the iterator, and may (but is not guaranteed to)
966	<	* reflect any modifications subsequent to construction.
3946	>	* Returns the result of accumulating the given transformation
3947	>	* of all values using the given reducer to combine values,
3948	>	* and the given basis as an identity value.
3949		*
3950	<	* @return a collection view of the values contained in this map.
3950	>	* @param parallelismThreshold the (estimated) number of elements
3951	>	* needed for this operation to be executed in parallel
3952	>	* @param transformer a function returning the transformation
3953	>	* for an element
3954	>	* @param basis the identity (initial default value) for the reduction
3955	>	* @param reducer a commutative associative combining function
3956	>	* @return the result of accumulating the given transformation
3957	>	* of all values
3958	>	* @since 1.8
3959		*/
3960	<	public Collection<V> values() {
3961	<	Collection<V> vs = values;
3962	<	return (vs != null) ? vs : (values = new Values());
3960	>	public long reduceValuesToLong(long parallelismThreshold,
3961	>	ToLongFunction<? super V> transformer,
3962	>	long basis,
3963	>	LongBinaryOperator reducer) {
3964	>	if (transformer == null || reducer == null)
3965	>	throw new NullPointerException();
3966	>	return new MapReduceValuesToLongTask<K,V>
3967	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3968	>	null, transformer, basis, reducer).invoke();
3969		}
3970
3971	+	/**
3972	+	* Returns the result of accumulating the given transformation
3973	+	* of all values using the given reducer to combine values,
3974	+	* and the given basis as an identity value.
3975	+	*
3976	+	* @param parallelismThreshold the (estimated) number of elements
3977	+	* needed for this operation to be executed in parallel
3978	+	* @param transformer a function returning the transformation
3979	+	* for an element
3980	+	* @param basis the identity (initial default value) for the reduction
3981	+	* @param reducer a commutative associative combining function
3982	+	* @return the result of accumulating the given transformation
3983	+	* of all values
3984	+	* @since 1.8
3985	+	*/
3986	+	public int reduceValuesToInt(long parallelismThreshold,
3987	+	ToIntFunction<? super V> transformer,
3988	+	int basis,
3989	+	IntBinaryOperator reducer) {
3990	+	if (transformer == null || reducer == null)
3991	+	throw new NullPointerException();
3992	+	return new MapReduceValuesToIntTask<K,V>
3993	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3994	+	null, transformer, basis, reducer).invoke();
3995	+	}
3996
3997		/**
3998	<	* Returns a collection view of the mappings contained in this map.  Each
978	<	* element in the returned collection is a <tt>Map.Entry</tt>.  The
979	<	* collection is backed by the map, so changes to the map are reflected in
980	<	* the collection, and vice-versa.  The collection supports element
981	<	* removal, which removes the corresponding mapping from the map, via the
982	<	* <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
983	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
984	<	* It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
985	<	* The returned <tt>iterator</tt> is a "weakly consistent" iterator that
986	<	* will never throw {@link java.util.ConcurrentModificationException},
987	<	* and guarantees to traverse elements as they existed upon
988	<	* construction of the iterator, and may (but is not guaranteed to)
989	<	* reflect any modifications subsequent to construction.
3998	>	* Performs the given action for each entry.
3999		*
4000	<	* @return a collection view of the mappings contained in this map.
4000	>	* @param parallelismThreshold the (estimated) number of elements
4001	>	* needed for this operation to be executed in parallel
4002	>	* @param action the action
4003	>	* @since 1.8
4004		*/
4005	<	public Set<Map.Entry<K,V>> entrySet() {
4006	<	Set<Map.Entry<K,V>> es = entrySet;
4007	<	return (es != null) ? es : (entrySet = (Set<Map.Entry<K,V>>) (Set) new EntrySet());
4005	>	public void forEachEntry(long parallelismThreshold,
4006	>	Consumer<? super Map.Entry<K,V>> action) {
4007	>	if (action == null) throw new NullPointerException();
4008	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4009	>	action).invoke();
4010		}
4011
4012	+	/**
4013	+	* Performs the given action for each non-null transformation
4014	+	* of each entry.
4015	+	*
4016	+	* @param parallelismThreshold the (estimated) number of elements
4017	+	* needed for this operation to be executed in parallel
4018	+	* @param transformer a function returning the transformation
4019	+	* for an element, or null if there is no transformation (in
4020	+	* which case the action is not applied)
4021	+	* @param action the action
4022	+	* @since 1.8
4023	+	*/
4024	+	public <U> void forEachEntry(long parallelismThreshold,
4025	+	Function<Map.Entry<K,V>, ? extends U> transformer,
4026	+	Consumer<? super U> action) {
4027	+	if (transformer == null || action == null)
4028	+	throw new NullPointerException();
4029	+	new ForEachTransformedEntryTask<K,V,U>
4030	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4031	+	transformer, action).invoke();
4032	+	}
4033
4034		/**
4035	<	* Returns an enumeration of the keys in this table.
4035	>	* Returns a non-null result from applying the given search
4036	>	* function on each entry, or null if none.  Upon success,
4037	>	* further element processing is suppressed and the results of
4038	>	* any other parallel invocations of the search function are
4039	>	* ignored.
4040		*
4041	<	* @return  an enumeration of the keys in this table.
4042	<	* @see     #keySet
4041	>	* @param parallelismThreshold the (estimated) number of elements
4042	>	* needed for this operation to be executed in parallel
4043	>	* @param searchFunction a function returning a non-null
4044	>	* result on success, else null
4045	>	* @return a non-null result from applying the given search
4046	>	* function on each entry, or null if none
4047	>	* @since 1.8
4048		*/
4049	<	public Enumeration<K> keys() {
4050	<	return new KeyIterator();
4049	>	public <U> U searchEntries(long parallelismThreshold,
4050	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4051	>	if (searchFunction == null) throw new NullPointerException();
4052	>	return new SearchEntriesTask<K,V,U>
4053	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4054	>	searchFunction, new AtomicReference<U>()).invoke();
4055		}
4056
4057		/**
4058	<	* Returns an enumeration of the values in this table.
4059	<	* Use the Enumeration methods on the returned object to fetch the elements
1012	<	* sequentially.
4058	>	* Returns the result of accumulating all entries using the
4059	>	* given reducer to combine values, or null if none.
4060		*
4061	<	* @return  an enumeration of the values in this table.
4062	<	* @see     #values
4061	>	* @param parallelismThreshold the (estimated) number of elements
4062	>	* needed for this operation to be executed in parallel
4063	>	* @param reducer a commutative associative combining function
4064	>	* @return the result of accumulating all entries
4065	>	* @since 1.8
4066		*/
4067	<	public Enumeration<V> elements() {
4068	<	return new ValueIterator();
4067	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4068	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4069	>	if (reducer == null) throw new NullPointerException();
4070	>	return new ReduceEntriesTask<K,V>
4071	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4072	>	null, reducer).invoke();
4073		}
4074
4075	<	/* ---------------- Iterator Support -------------- */
4075	>	/**
4076	>	* Returns the result of accumulating the given transformation
4077	>	* of all entries using the given reducer to combine values,
4078	>	* or null if none.
4079	>	*
4080	>	* @param parallelismThreshold the (estimated) number of elements
4081	>	* needed for this operation to be executed in parallel
4082	>	* @param transformer a function returning the transformation
4083	>	* for an element, or null if there is no transformation (in
4084	>	* which case it is not combined)
4085	>	* @param reducer a commutative associative combining function
4086	>	* @return the result of accumulating the given transformation
4087	>	* of all entries
4088	>	* @since 1.8
4089	>	*/
4090	>	public <U> U reduceEntries(long parallelismThreshold,
4091	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4092	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4093	>	if (transformer == null || reducer == null)
4094	>	throw new NullPointerException();
4095	>	return new MapReduceEntriesTask<K,V,U>
4096	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4097	>	null, transformer, reducer).invoke();
4098	>	}
4099
4100	<	private abstract class HashIterator {
4101	<	private int nextSegmentIndex;
4102	<	private int nextTableIndex;
4103	<	private HashEntry[] currentTable;
4104	<	private HashEntry<K, V> nextEntry;
4105	<	HashEntry<K, V> lastReturned;
4100	>	/**
4101	>	* Returns the result of accumulating the given transformation
4102	>	* of all entries using the given reducer to combine values,
4103	>	* and the given basis as an identity value.
4104	>	*
4105	>	* @param parallelismThreshold the (estimated) number of elements
4106	>	* needed for this operation to be executed in parallel
4107	>	* @param transformer a function returning the transformation
4108	>	* for an element
4109	>	* @param basis the identity (initial default value) for the reduction
4110	>	* @param reducer a commutative associative combining function
4111	>	* @return the result of accumulating the given transformation
4112	>	* of all entries
4113	>	* @since 1.8
4114	>	*/
4115	>	public double reduceEntriesToDouble(long parallelismThreshold,
4116	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4117	>	double basis,
4118	>	DoubleBinaryOperator reducer) {
4119	>	if (transformer == null || reducer == null)
4120	>	throw new NullPointerException();
4121	>	return new MapReduceEntriesToDoubleTask<K,V>
4122	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4123	>	null, transformer, basis, reducer).invoke();
4124	>	}
4125
4126	<	private HashIterator() {
4127	<	nextSegmentIndex = segments.length - 1;
4128	<	nextTableIndex = -1;
4129	<	advance();
4130	<	}
4126	>	/**
4127	>	* Returns the result of accumulating the given transformation
4128	>	* of all entries using the given reducer to combine values,
4129	>	* and the given basis as an identity value.
4130	>	*
4131	>	* @param parallelismThreshold the (estimated) number of elements
4132	>	* needed for this operation to be executed in parallel
4133	>	* @param transformer a function returning the transformation
4134	>	* for an element
4135	>	* @param basis the identity (initial default value) for the reduction
4136	>	* @param reducer a commutative associative combining function
4137	>	* @return the result of accumulating the given transformation
4138	>	* of all entries
4139	>	* @since 1.8
4140	>	*/
4141	>	public long reduceEntriesToLong(long parallelismThreshold,
4142	>	ToLongFunction<Map.Entry<K,V>> transformer,
4143	>	long basis,
4144	>	LongBinaryOperator reducer) {
4145	>	if (transformer == null || reducer == null)
4146	>	throw new NullPointerException();
4147	>	return new MapReduceEntriesToLongTask<K,V>
4148	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4149	>	null, transformer, basis, reducer).invoke();
4150	>	}
4151	>
4152	>	/**
4153	>	* Returns the result of accumulating the given transformation
4154	>	* of all entries using the given reducer to combine values,
4155	>	* and the given basis as an identity value.
4156	>	*
4157	>	* @param parallelismThreshold the (estimated) number of elements
4158	>	* needed for this operation to be executed in parallel
4159	>	* @param transformer a function returning the transformation
4160	>	* for an element
4161	>	* @param basis the identity (initial default value) for the reduction
4162	>	* @param reducer a commutative associative combining function
4163	>	* @return the result of accumulating the given transformation
4164	>	* of all entries
4165	>	* @since 1.8
4166	>	*/
4167	>	public int reduceEntriesToInt(long parallelismThreshold,
4168	>	ToIntFunction<Map.Entry<K,V>> transformer,
4169	>	int basis,
4170	>	IntBinaryOperator reducer) {
4171	>	if (transformer == null || reducer == null)
4172	>	throw new NullPointerException();
4173	>	return new MapReduceEntriesToIntTask<K,V>
4174	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4175	>	null, transformer, basis, reducer).invoke();
4176	>	}
4177
1036	–	public boolean hasMoreElements() { return hasNext(); }
4178
4179	<	private void advance() {
1039	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
1040	<	return;
4179	>	/* ----------------Views -------------- */
4180
4181	<	while (nextTableIndex >= 0) {
4182	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
4183	<	return;
4181	>	/**
4182	>	* Base class for views.
4183	>	*/
4184	>	abstract static class CollectionView<K,V,E>
4185	>	implements Collection<E>, java.io.Serializable {
4186	>	private static final long serialVersionUID = 7249069246763182397L;
4187	>	final ConcurrentHashMap<K,V> map;
4188	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4189	>
4190	>	/**
4191	>	* Returns the map backing this view.
4192	>	*
4193	>	* @return the map backing this view
4194	>	*/
4195	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4196	>
4197	>	/**
4198	>	* Removes all of the elements from this view, by removing all
4199	>	* the mappings from the map backing this view.
4200	>	*/
4201	>	public final void clear()      { map.clear(); }
4202	>	public final int size()        { return map.size(); }
4203	>	public final boolean isEmpty() { return map.isEmpty(); }
4204	>
4205	>	// implementations below rely on concrete classes supplying these
4206	>	// abstract methods
4207	>	/**
4208	>	* Returns a "weakly consistent" iterator that will never
4209	>	* throw {@link ConcurrentModificationException}, and
4210	>	* guarantees to traverse elements as they existed upon
4211	>	* construction of the iterator, and may (but is not
4212	>	* guaranteed to) reflect any modifications subsequent to
4213	>	* construction.
4214	>	*/
4215	>	public abstract Iterator<E> iterator();
4216	>	public abstract boolean contains(Object o);
4217	>	public abstract boolean remove(Object o);
4218	>
4219	>	private static final String oomeMsg = "Required array size too large";
4220	>
4221	>	public final Object[] toArray() {
4222	>	long sz = map.mappingCount();
4223	>	if (sz > MAX_ARRAY_SIZE)
4224	>	throw new OutOfMemoryError(oomeMsg);
4225	>	int n = (int)sz;
4226	>	Object[] r = new Object[n];
4227	>	int i = 0;
4228	>	for (E e : this) {
4229	>	if (i == n) {
4230	>	if (n >= MAX_ARRAY_SIZE)
4231	>	throw new OutOfMemoryError(oomeMsg);
4232	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4233	>	n = MAX_ARRAY_SIZE;
4234	>	else
4235	>	n += (n >>> 1) + 1;
4236	>	r = Arrays.copyOf(r, n);
4237	>	}
4238	>	r[i++] = e;
4239		}
4240	+	return (i == n) ? r : Arrays.copyOf(r, i);
4241	+	}
4242
4243	<	while (nextSegmentIndex >= 0) {
4244	<	Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
4245	<	if (seg.count != 0) {
4246	<	currentTable = seg.table;
4247	<	for (int j = currentTable.length - 1; j >= 0; --j) {
4248	<	if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
4249	<	nextTableIndex = j - 1;
4250	<	return;
4251	<	}
4252	<	}
4243	>	@SuppressWarnings("unchecked")
4244	>	public final <T> T[] toArray(T[] a) {
4245	>	long sz = map.mappingCount();
4246	>	if (sz > MAX_ARRAY_SIZE)
4247	>	throw new OutOfMemoryError(oomeMsg);
4248	>	int m = (int)sz;
4249	>	T[] r = (a.length >= m) ? a :
4250	>	(T[])java.lang.reflect.Array
4251	>	.newInstance(a.getClass().getComponentType(), m);
4252	>	int n = r.length;
4253	>	int i = 0;
4254	>	for (E e : this) {
4255	>	if (i == n) {
4256	>	if (n >= MAX_ARRAY_SIZE)
4257	>	throw new OutOfMemoryError(oomeMsg);
4258	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4259	>	n = MAX_ARRAY_SIZE;
4260	>	else
4261	>	n += (n >>> 1) + 1;
4262	>	r = Arrays.copyOf(r, n);
4263		}
4264	+	r[i++] = (T)e;
4265	+	}
4266	+	if (a == r && i < n) {
4267	+	r[i] = null; // null-terminate
4268	+	return r;
4269		}
4270	+	return (i == n) ? r : Arrays.copyOf(r, i);
4271		}
4272
4273	<	public boolean hasNext() { return nextEntry != null; }
4273	>	/**
4274	>	* Returns a string representation of this collection.
4275	>	* The string representation consists of the string representations
4276	>	* of the collection's elements in the order they are returned by
4277	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4278	>	* Adjacent elements are separated by the characters {@code ", "}
4279	>	* (comma and space).  Elements are converted to strings as by
4280	>	* {@link String#valueOf(Object)}.
4281	>	*
4282	>	* @return a string representation of this collection
4283	>	*/
4284	>	public final String toString() {
4285	>	StringBuilder sb = new StringBuilder();
4286	>	sb.append('[');
4287	>	Iterator<E> it = iterator();
4288	>	if (it.hasNext()) {
4289	>	for (;;) {
4290	>	Object e = it.next();
4291	>	sb.append(e == this ? "(this Collection)" : e);
4292	>	if (!it.hasNext())
4293	>	break;
4294	>	sb.append(',').append(' ');
4295	>	}
4296	>	}
4297	>	return sb.append(']').toString();
4298	>	}
4299
4300	<	HashEntry<K,V> nextEntry() {
4301	<	if (nextEntry == null)
4302	<	throw new NoSuchElementException();
4303	<	lastReturned = nextEntry;
4304	<	advance();
4305	<	return lastReturned;
4300	>	public final boolean containsAll(Collection<?> c) {
4301	>	if (c != this) {
4302	>	for (Object e : c) {
4303	>	if (e == null || !contains(e))
4304	>	return false;
4305	>	}
4306	>	}
4307	>	return true;
4308		}
4309
4310	<	public void remove() {
4311	<	if (lastReturned == null)
4312	<	throw new IllegalStateException();
4313	<	ConcurrentHashMap.this.remove(lastReturned.key);
4314	<	lastReturned = null;
4310	>	public final boolean removeAll(Collection<?> c) {
4311	>	boolean modified = false;
4312	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4313	>	if (c.contains(it.next())) {
4314	>	it.remove();
4315	>	modified = true;
4316	>	}
4317	>	}
4318	>	return modified;
4319		}
1077	–	}
4320
4321	<	private class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
4322	<	public K next() { return super.nextEntry().key; }
4323	<	public K nextElement() { return super.nextEntry().key; }
4324	<	}
4321	>	public final boolean retainAll(Collection<?> c) {
4322	>	boolean modified = false;
4323	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4324	>	if (!c.contains(it.next())) {
4325	>	it.remove();
4326	>	modified = true;
4327	>	}
4328	>	}
4329	>	return modified;
4330	>	}
4331
1084	–	private class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
1085	–	public V next() { return super.nextEntry().value; }
1086	–	public V nextElement() { return super.nextEntry().value; }
4332		}
4333
1089	–
1090	–
4334		/**
4335	<	* Exported Entry objects must write-through changes in setValue,
4336	<	* even if the nodes have been cloned. So we cannot return
4337	<	* internal HashEntry objects. Instead, the iterator itself acts
4338	<	* as a forwarding pseudo-entry.
4335	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4336	>	* which additions may optionally be enabled by mapping to a
4337	>	* common value.  This class cannot be directly instantiated.
4338	>	* See {@link #keySet() keySet()},
4339	>	* {@link #keySet(Object) keySet(V)},
4340	>	* {@link #newKeySet() newKeySet()},
4341	>	* {@link #newKeySet(int) newKeySet(int)}.
4342	>	*
4343	>	* @since 1.8
4344		*/
4345	<	private class EntryIterator extends HashIterator implements Map.Entry<K,V>, Iterator<Entry<K,V>> {
4346	<	public Map.Entry<K,V> next() {
4347	<	nextEntry();
4348	<	return this;
4345	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4346	>	implements Set<K>, java.io.Serializable {
4347	>	private static final long serialVersionUID = 7249069246763182397L;
4348	>	private final V value;
4349	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4350	>	super(map);
4351	>	this.value = value;
4352		}
4353
4354	<	public K getKey() {
4355	<	if (lastReturned == null)
4356	<	throw new IllegalStateException("Entry was removed");
4357	<	return lastReturned.key;
4354	>	/**
4355	>	* Returns the default mapped value for additions,
4356	>	* or {@code null} if additions are not supported.
4357	>	*
4358	>	* @return the default mapped value for additions, or {@code null}
4359	>	* if not supported
4360	>	*/
4361	>	public V getMappedValue() { return value; }
4362	>
4363	>	/**
4364	>	* {@inheritDoc}
4365	>	* @throws NullPointerException if the specified key is null
4366	>	*/
4367	>	public boolean contains(Object o) { return map.containsKey(o); }
4368	>
4369	>	/**
4370	>	* Removes the key from this map view, by removing the key (and its
4371	>	* corresponding value) from the backing map.  This method does
4372	>	* nothing if the key is not in the map.
4373	>	*
4374	>	* @param  o the key to be removed from the backing map
4375	>	* @return {@code true} if the backing map contained the specified key
4376	>	* @throws NullPointerException if the specified key is null
4377	>	*/
4378	>	public boolean remove(Object o) { return map.remove(o) != null; }
4379	>
4380	>	/**
4381	>	* @return an iterator over the keys of the backing map
4382	>	*/
4383	>	public Iterator<K> iterator() {
4384	>	Node<K,V>[] t;
4385	>	ConcurrentHashMap<K,V> m = map;
4386	>	int f = (t = m.table) == null ? 0 : t.length;
4387	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4388		}
4389
4390	<	public V getValue() {
4391	<	if (lastReturned == null)
4392	<	throw new IllegalStateException("Entry was removed");
4393	<	return ConcurrentHashMap.this.get(lastReturned.key);
4390	>	/**
4391	>	* Adds the specified key to this set view by mapping the key to
4392	>	* the default mapped value in the backing map, if defined.
4393	>	*
4394	>	* @param e key to be added
4395	>	* @return {@code true} if this set changed as a result of the call
4396	>	* @throws NullPointerException if the specified key is null
4397	>	* @throws UnsupportedOperationException if no default mapped value
4398	>	* for additions was provided
4399	>	*/
4400	>	public boolean add(K e) {
4401	>	V v;
4402	>	if ((v = value) == null)
4403	>	throw new UnsupportedOperationException();
4404	>	return map.putVal(e, v, true) == null;
4405		}
4406
4407	<	public V setValue(V value) {
4408	<	if (lastReturned == null)
4409	<	throw new IllegalStateException("Entry was removed");
4410	<	return ConcurrentHashMap.this.put(lastReturned.key, value);
4407	>	/**
4408	>	* Adds all of the elements in the specified collection to this set,
4409	>	* as if by calling {@link #add} on each one.
4410	>	*
4411	>	* @param c the elements to be inserted into this set
4412	>	* @return {@code true} if this set changed as a result of the call
4413	>	* @throws NullPointerException if the collection or any of its
4414	>	* elements are {@code null}
4415	>	* @throws UnsupportedOperationException if no default mapped value
4416	>	* for additions was provided
4417	>	*/
4418	>	public boolean addAll(Collection<? extends K> c) {
4419	>	boolean added = false;
4420	>	V v;
4421	>	if ((v = value) == null)
4422	>	throw new UnsupportedOperationException();
4423	>	for (K e : c) {
4424	>	if (map.putVal(e, v, true) == null)
4425	>	added = true;
4426	>	}
4427	>	return added;
4428	>	}
4429	>
4430	>	public int hashCode() {
4431	>	int h = 0;
4432	>	for (K e : this)
4433	>	h += e.hashCode();
4434	>	return h;
4435		}
4436
4437		public boolean equals(Object o) {
4438	<	if (!(o instanceof Map.Entry))
4439	<	return false;
4440	<	Map.Entry e = (Map.Entry)o;
4441	<	return eq(getKey(), e.getKey()) && eq(getValue(), e.getValue());
4442	<	}
4438	>	Set<?> c;
4439	>	return ((o instanceof Set) &&
4440	>	((c = (Set<?>)o) == this ||
4441	>	(containsAll(c) && c.containsAll(this))));
4442	>	}
4443	>
4444	>	public Spliterator<K> spliterator() {
4445	>	Node<K,V>[] t;
4446	>	ConcurrentHashMap<K,V> m = map;
4447	>	long n = m.sumCount();
4448	>	int f = (t = m.table) == null ? 0 : t.length;
4449	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4450	>	}
4451	>
4452	>	public void forEach(Consumer<? super K> action) {
4453	>	if (action == null) throw new NullPointerException();
4454	>	Node<K,V>[] t;
4455	>	if ((t = map.table) != null) {
4456	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4457	>	for (Node<K,V> p; (p = it.advance()) != null; )
4458	>	action.accept(p.key);
4459	>	}
4460	>	}
4461	>	}
4462
4463	<	public int hashCode() {
4464	<	Object k = getKey();
4465	<	Object v = getValue();
4466	<	return ((k == null) ? 0 : k.hashCode()) ^
4467	<	((v == null) ? 0 : v.hashCode());
4463	>	/**
4464	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4465	>	* values, in which additions are disabled. This class cannot be
4466	>	* directly instantiated. See {@link #values()}.
4467	>	*/
4468	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4469	>	implements Collection<V>, java.io.Serializable {
4470	>	private static final long serialVersionUID = 2249069246763182397L;
4471	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4472	>	public final boolean contains(Object o) {
4473	>	return map.containsValue(o);
4474	>	}
4475	>
4476	>	public final boolean remove(Object o) {
4477	>	if (o != null) {
4478	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4479	>	if (o.equals(it.next())) {
4480	>	it.remove();
4481	>	return true;
4482	>	}
4483	>	}
4484	>	}
4485	>	return false;
4486	>	}
4487	>
4488	>	public final Iterator<V> iterator() {
4489	>	ConcurrentHashMap<K,V> m = map;
4490	>	Node<K,V>[] t;
4491	>	int f = (t = m.table) == null ? 0 : t.length;
4492	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4493	>	}
4494	>
4495	>	public final boolean add(V e) {
4496	>	throw new UnsupportedOperationException();
4497	>	}
4498	>	public final boolean addAll(Collection<? extends V> c) {
4499	>	throw new UnsupportedOperationException();
4500	>	}
4501	>
4502	>	public Spliterator<V> spliterator() {
4503	>	Node<K,V>[] t;
4504	>	ConcurrentHashMap<K,V> m = map;
4505	>	long n = m.sumCount();
4506	>	int f = (t = m.table) == null ? 0 : t.length;
4507	>	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4508	>	}
4509	>
4510	>	public void forEach(Consumer<? super V> action) {
4511	>	if (action == null) throw new NullPointerException();
4512	>	Node<K,V>[] t;
4513	>	if ((t = map.table) != null) {
4514	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4515	>	for (Node<K,V> p; (p = it.advance()) != null; )
4516	>	action.accept(p.val);
4517	>	}
4518	>	}
4519	>	}
4520	>
4521	>	/**
4522	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4523	>	* entries.  This class cannot be directly instantiated. See
4524	>	* {@link #entrySet()}.
4525	>	*/
4526	>	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4527	>	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4528	>	private static final long serialVersionUID = 2249069246763182397L;
4529	>	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4530	>
4531	>	public boolean contains(Object o) {
4532	>	Object k, v, r; Map.Entry<?,?> e;
4533	>	return ((o instanceof Map.Entry) &&
4534	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4535	>	(r = map.get(k)) != null &&
4536	>	(v = e.getValue()) != null &&
4537	>	(v == r || v.equals(r)));
4538	>	}
4539	>
4540	>	public boolean remove(Object o) {
4541	>	Object k, v; Map.Entry<?,?> e;
4542	>	return ((o instanceof Map.Entry) &&
4543	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4544	>	(v = e.getValue()) != null &&
4545	>	map.remove(k, v));
4546	>	}
4547	>
4548	>	/**
4549	>	* @return an iterator over the entries of the backing map
4550	>	*/
4551	>	public Iterator<Map.Entry<K,V>> iterator() {
4552	>	ConcurrentHashMap<K,V> m = map;
4553	>	Node<K,V>[] t;
4554	>	int f = (t = m.table) == null ? 0 : t.length;
4555	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4556	>	}
4557	>
4558	>	public boolean add(Entry<K,V> e) {
4559	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4560	>	}
4561	>
4562	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4563	>	boolean added = false;
4564	>	for (Entry<K,V> e : c) {
4565	>	if (add(e))
4566	>	added = true;
4567	>	}
4568	>	return added;
4569		}
4570
4571	<	public String toString() {
4572	<	return getKey() + "=" + getValue();
4571	>	public final int hashCode() {
4572	>	int h = 0;
4573	>	Node<K,V>[] t;
4574	>	if ((t = map.table) != null) {
4575	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4576	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4577	>	h += p.hashCode();
4578	>	}
4579	>	}
4580	>	return h;
4581		}
4582
4583	<	private boolean eq(Object o1, Object o2) {
4584	<	return (o1 == null ? o2 == null : o1.equals(o2));
4583	>	public final boolean equals(Object o) {
4584	>	Set<?> c;
4585	>	return ((o instanceof Set) &&
4586	>	((c = (Set<?>)o) == this ||
4587	>	(containsAll(c) && c.containsAll(this))));
4588	>	}
4589	>
4590	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4591	>	Node<K,V>[] t;
4592	>	ConcurrentHashMap<K,V> m = map;
4593	>	long n = m.sumCount();
4594	>	int f = (t = m.table) == null ? 0 : t.length;
4595	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4596	>	}
4597	>
4598	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4599	>	if (action == null) throw new NullPointerException();
4600	>	Node<K,V>[] t;
4601	>	if ((t = map.table) != null) {
4602	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4603	>	for (Node<K,V> p; (p = it.advance()) != null; )
4604	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4605	>	}
4606		}
4607
4608		}
4609
4610	<	private class KeySet extends AbstractSet<K> {
4611	<	public Iterator<K> iterator() {
4612	<	return new KeyIterator();
4610	>	// -------------------------------------------------------
4611	>
4612	>	/**
4613	>	* Base class for bulk tasks. Repeats some fields and code from
4614	>	* class Traverser, because we need to subclass CountedCompleter.
4615	>	*/
4616	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4617	>	Node<K,V>[] tab;        // same as Traverser
4618	>	Node<K,V> next;
4619	>	int index;
4620	>	int baseIndex;
4621	>	int baseLimit;
4622	>	final int baseSize;
4623	>	int batch;              // split control
4624	>
4625	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4626	>	super(par);
4627	>	this.batch = b;
4628	>	this.index = this.baseIndex = i;
4629	>	if ((this.tab = t) == null)
4630	>	this.baseSize = this.baseLimit = 0;
4631	>	else if (par == null)
4632	>	this.baseSize = this.baseLimit = t.length;
4633	>	else {
4634	>	this.baseLimit = f;
4635	>	this.baseSize = par.baseSize;
4636	>	}
4637		}
4638	<	public int size() {
4639	<	return ConcurrentHashMap.this.size();
4638	>
4639	>	/**
4640	>	* Same as Traverser version
4641	>	*/
4642	>	final Node<K,V> advance() {
4643	>	Node<K,V> e;
4644	>	if ((e = next) != null)
4645	>	e = e.next;
4646	>	for (;;) {
4647	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4648	>	if (e != null)
4649	>	return next = e;
4650	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4651	>	(n = t.length) <= (i = index) || i < 0)
4652	>	return next = null;
4653	>	if ((e = tabAt(t, index)) != null && e.key == null) {
4654	>	if (e instanceof ForwardingNode) {
4655	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4656	>	e = null;
4657	>	continue;
4658	>	}
4659	>	else if (e instanceof TreeBin)
4660	>	e = ((TreeBin<K,V>)e).first;
4661	>	else
4662	>	e = null;
4663	>	}
4664	>	if ((index += baseSize) >= n)
4665	>	index = ++baseIndex;    // visit upper slots if present
4666	>	}
4667		}
4668	<	public boolean contains(Object o) {
4669	<	return ConcurrentHashMap.this.containsKey(o);
4668	>	}
4669	>
4670	>	/*
4671	>	* Task classes. Coded in a regular but ugly format/style to
4672	>	* simplify checks that each variant differs in the right way from
4673	>	* others. The null screenings exist because compilers cannot tell
4674	>	* that we've already null-checked task arguments, so we force
4675	>	* simplest hoisted bypass to help avoid convoluted traps.
4676	>	*/
4677	>	@SuppressWarnings("serial")
4678	>	static final class ForEachKeyTask<K,V>
4679	>	extends BulkTask<K,V,Void> {
4680	>	final Consumer<? super K> action;
4681	>	ForEachKeyTask
4682	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4683	>	Consumer<? super K> action) {
4684	>	super(p, b, i, f, t);
4685	>	this.action = action;
4686	>	}
4687	>	public final void compute() {
4688	>	final Consumer<? super K> action;
4689	>	if ((action = this.action) != null) {
4690	>	for (int i = baseIndex, f, h; batch > 0 &&
4691	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4692	>	addToPendingCount(1);
4693	>	new ForEachKeyTask<K,V>
4694	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4695	>	action).fork();
4696	>	}
4697	>	for (Node<K,V> p; (p = advance()) != null;)
4698	>	action.accept(p.key);
4699	>	propagateCompletion();
4700	>	}
4701		}
4702	<	public boolean remove(Object o) {
4703	<	return ConcurrentHashMap.this.remove(o) != null;
4702	>	}
4703	>
4704	>	@SuppressWarnings("serial")
4705	>	static final class ForEachValueTask<K,V>
4706	>	extends BulkTask<K,V,Void> {
4707	>	final Consumer<? super V> action;
4708	>	ForEachValueTask
4709	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4710	>	Consumer<? super V> action) {
4711	>	super(p, b, i, f, t);
4712	>	this.action = action;
4713	>	}
4714	>	public final void compute() {
4715	>	final Consumer<? super V> action;
4716	>	if ((action = this.action) != null) {
4717	>	for (int i = baseIndex, f, h; batch > 0 &&
4718	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4719	>	addToPendingCount(1);
4720	>	new ForEachValueTask<K,V>
4721	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4722	>	action).fork();
4723	>	}
4724	>	for (Node<K,V> p; (p = advance()) != null;)
4725	>	action.accept(p.val);
4726	>	propagateCompletion();
4727	>	}
4728		}
4729	<	public void clear() {
4730	<	ConcurrentHashMap.this.clear();
4729	>	}
4730	>
4731	>	@SuppressWarnings("serial")
4732	>	static final class ForEachEntryTask<K,V>
4733	>	extends BulkTask<K,V,Void> {
4734	>	final Consumer<? super Entry<K,V>> action;
4735	>	ForEachEntryTask
4736	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4737	>	Consumer<? super Entry<K,V>> action) {
4738	>	super(p, b, i, f, t);
4739	>	this.action = action;
4740	>	}
4741	>	public final void compute() {
4742	>	final Consumer<? super Entry<K,V>> action;
4743	>	if ((action = this.action) != null) {
4744	>	for (int i = baseIndex, f, h; batch > 0 &&
4745	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4746	>	addToPendingCount(1);
4747	>	new ForEachEntryTask<K,V>
4748	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4749	>	action).fork();
4750	>	}
4751	>	for (Node<K,V> p; (p = advance()) != null; )
4752	>	action.accept(p);
4753	>	propagateCompletion();
4754	>	}
4755		}
4756		}
4757
4758	<	private class Values extends AbstractCollection<V> {
4759	<	public Iterator<V> iterator() {
4760	<	return new ValueIterator();
4758	>	@SuppressWarnings("serial")
4759	>	static final class ForEachMappingTask<K,V>
4760	>	extends BulkTask<K,V,Void> {
4761	>	final BiConsumer<? super K, ? super V> action;
4762	>	ForEachMappingTask
4763	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4764	>	BiConsumer<? super K,? super V> action) {
4765	>	super(p, b, i, f, t);
4766	>	this.action = action;
4767	>	}
4768	>	public final void compute() {
4769	>	final BiConsumer<? super K, ? super V> action;
4770	>	if ((action = this.action) != null) {
4771	>	for (int i = baseIndex, f, h; batch > 0 &&
4772	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4773	>	addToPendingCount(1);
4774	>	new ForEachMappingTask<K,V>
4775	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4776	>	action).fork();
4777	>	}
4778	>	for (Node<K,V> p; (p = advance()) != null; )
4779	>	action.accept(p.key, p.val);
4780	>	propagateCompletion();
4781	>	}
4782		}
4783	<	public int size() {
4784	<	return ConcurrentHashMap.this.size();
4783	>	}
4784	>
4785	>	@SuppressWarnings("serial")
4786	>	static final class ForEachTransformedKeyTask<K,V,U>
4787	>	extends BulkTask<K,V,Void> {
4788	>	final Function<? super K, ? extends U> transformer;
4789	>	final Consumer<? super U> action;
4790	>	ForEachTransformedKeyTask
4791	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4792	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4793	>	super(p, b, i, f, t);
4794	>	this.transformer = transformer; this.action = action;
4795	>	}
4796	>	public final void compute() {
4797	>	final Function<? super K, ? extends U> transformer;
4798	>	final Consumer<? super U> action;
4799	>	if ((transformer = this.transformer) != null &&
4800	>	(action = this.action) != null) {
4801	>	for (int i = baseIndex, f, h; batch > 0 &&
4802	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4803	>	addToPendingCount(1);
4804	>	new ForEachTransformedKeyTask<K,V,U>
4805	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4806	>	transformer, action).fork();
4807	>	}
4808	>	for (Node<K,V> p; (p = advance()) != null; ) {
4809	>	U u;
4810	>	if ((u = transformer.apply(p.key)) != null)
4811	>	action.accept(u);
4812	>	}
4813	>	propagateCompletion();
4814	>	}
4815		}
4816	<	public boolean contains(Object o) {
4817	<	return ConcurrentHashMap.this.containsValue(o);
4816	>	}
4817	>
4818	>	@SuppressWarnings("serial")
4819	>	static final class ForEachTransformedValueTask<K,V,U>
4820	>	extends BulkTask<K,V,Void> {
4821	>	final Function<? super V, ? extends U> transformer;
4822	>	final Consumer<? super U> action;
4823	>	ForEachTransformedValueTask
4824	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4825	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4826	>	super(p, b, i, f, t);
4827	>	this.transformer = transformer; this.action = action;
4828	>	}
4829	>	public final void compute() {
4830	>	final Function<? super V, ? extends U> transformer;
4831	>	final Consumer<? super U> action;
4832	>	if ((transformer = this.transformer) != null &&
4833	>	(action = this.action) != null) {
4834	>	for (int i = baseIndex, f, h; batch > 0 &&
4835	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4836	>	addToPendingCount(1);
4837	>	new ForEachTransformedValueTask<K,V,U>
4838	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4839	>	transformer, action).fork();
4840	>	}
4841	>	for (Node<K,V> p; (p = advance()) != null; ) {
4842	>	U u;
4843	>	if ((u = transformer.apply(p.val)) != null)
4844	>	action.accept(u);
4845	>	}
4846	>	propagateCompletion();
4847	>	}
4848		}
4849	<	public void clear() {
4850	<	ConcurrentHashMap.this.clear();
4849	>	}
4850	>
4851	>	@SuppressWarnings("serial")
4852	>	static final class ForEachTransformedEntryTask<K,V,U>
4853	>	extends BulkTask<K,V,Void> {
4854	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4855	>	final Consumer<? super U> action;
4856	>	ForEachTransformedEntryTask
4857	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4858	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4859	>	super(p, b, i, f, t);
4860	>	this.transformer = transformer; this.action = action;
4861	>	}
4862	>	public final void compute() {
4863	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4864	>	final Consumer<? super U> action;
4865	>	if ((transformer = this.transformer) != null &&
4866	>	(action = this.action) != null) {
4867	>	for (int i = baseIndex, f, h; batch > 0 &&
4868	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4869	>	addToPendingCount(1);
4870	>	new ForEachTransformedEntryTask<K,V,U>
4871	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4872	>	transformer, action).fork();
4873	>	}
4874	>	for (Node<K,V> p; (p = advance()) != null; ) {
4875	>	U u;
4876	>	if ((u = transformer.apply(p)) != null)
4877	>	action.accept(u);
4878	>	}
4879	>	propagateCompletion();
4880	>	}
4881		}
4882		}
4883
4884	<	private class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4885	<	public Iterator<Map.Entry<K,V>> iterator() {
4886	<	return new EntryIterator();
4884	>	@SuppressWarnings("serial")
4885	>	static final class ForEachTransformedMappingTask<K,V,U>
4886	>	extends BulkTask<K,V,Void> {
4887	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4888	>	final Consumer<? super U> action;
4889	>	ForEachTransformedMappingTask
4890	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4891	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4892	>	Consumer<? super U> action) {
4893	>	super(p, b, i, f, t);
4894	>	this.transformer = transformer; this.action = action;
4895	>	}
4896	>	public final void compute() {
4897	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4898	>	final Consumer<? super U> action;
4899	>	if ((transformer = this.transformer) != null &&
4900	>	(action = this.action) != null) {
4901	>	for (int i = baseIndex, f, h; batch > 0 &&
4902	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4903	>	addToPendingCount(1);
4904	>	new ForEachTransformedMappingTask<K,V,U>
4905	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4906	>	transformer, action).fork();
4907	>	}
4908	>	for (Node<K,V> p; (p = advance()) != null; ) {
4909	>	U u;
4910	>	if ((u = transformer.apply(p.key, p.val)) != null)
4911	>	action.accept(u);
4912	>	}
4913	>	propagateCompletion();
4914	>	}
4915		}
4916	<	public boolean contains(Object o) {
4917	<	if (!(o instanceof Map.Entry))
4918	<	return false;
4919	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4920	<	V v = ConcurrentHashMap.this.get(e.getKey());
4921	<	return v != null && v.equals(e.getValue());
4916	>	}
4917	>
4918	>	@SuppressWarnings("serial")
4919	>	static final class SearchKeysTask<K,V,U>
4920	>	extends BulkTask<K,V,U> {
4921	>	final Function<? super K, ? extends U> searchFunction;
4922	>	final AtomicReference<U> result;
4923	>	SearchKeysTask
4924	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4925	>	Function<? super K, ? extends U> searchFunction,
4926	>	AtomicReference<U> result) {
4927	>	super(p, b, i, f, t);
4928	>	this.searchFunction = searchFunction; this.result = result;
4929	>	}
4930	>	public final U getRawResult() { return result.get(); }
4931	>	public final void compute() {
4932	>	final Function<? super K, ? extends U> searchFunction;
4933	>	final AtomicReference<U> result;
4934	>	if ((searchFunction = this.searchFunction) != null &&
4935	>	(result = this.result) != null) {
4936	>	for (int i = baseIndex, f, h; batch > 0 &&
4937	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4938	>	if (result.get() != null)
4939	>	return;
4940	>	addToPendingCount(1);
4941	>	new SearchKeysTask<K,V,U>
4942	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4943	>	searchFunction, result).fork();
4944	>	}
4945	>	while (result.get() == null) {
4946	>	U u;
4947	>	Node<K,V> p;
4948	>	if ((p = advance()) == null) {
4949	>	propagateCompletion();
4950	>	break;
4951	>	}
4952	>	if ((u = searchFunction.apply(p.key)) != null) {
4953	>	if (result.compareAndSet(null, u))
4954	>	quietlyCompleteRoot();
4955	>	break;
4956	>	}
4957	>	}
4958	>	}
4959		}
4960	<	public boolean remove(Object o) {
4961	<	if (!(o instanceof Map.Entry))
4962	<	return false;
4963	<	Map.Entry<K,V> e = (Map.Entry<K,V>)o;
4964	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4960	>	}
4961	>
4962	>	@SuppressWarnings("serial")
4963	>	static final class SearchValuesTask<K,V,U>
4964	>	extends BulkTask<K,V,U> {
4965	>	final Function<? super V, ? extends U> searchFunction;
4966	>	final AtomicReference<U> result;
4967	>	SearchValuesTask
4968	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4969	>	Function<? super V, ? extends U> searchFunction,
4970	>	AtomicReference<U> result) {
4971	>	super(p, b, i, f, t);
4972	>	this.searchFunction = searchFunction; this.result = result;
4973	>	}
4974	>	public final U getRawResult() { return result.get(); }
4975	>	public final void compute() {
4976	>	final Function<? super V, ? extends U> searchFunction;
4977	>	final AtomicReference<U> result;
4978	>	if ((searchFunction = this.searchFunction) != null &&
4979	>	(result = this.result) != null) {
4980	>	for (int i = baseIndex, f, h; batch > 0 &&
4981	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4982	>	if (result.get() != null)
4983	>	return;
4984	>	addToPendingCount(1);
4985	>	new SearchValuesTask<K,V,U>
4986	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4987	>	searchFunction, result).fork();
4988	>	}
4989	>	while (result.get() == null) {
4990	>	U u;
4991	>	Node<K,V> p;
4992	>	if ((p = advance()) == null) {
4993	>	propagateCompletion();
4994	>	break;
4995	>	}
4996	>	if ((u = searchFunction.apply(p.val)) != null) {
4997	>	if (result.compareAndSet(null, u))
4998	>	quietlyCompleteRoot();
4999	>	break;
5000	>	}
5001	>	}
5002	>	}
5003		}
5004	<	public int size() {
5005	<	return ConcurrentHashMap.this.size();
5004	>	}
5005	>
5006	>	@SuppressWarnings("serial")
5007	>	static final class SearchEntriesTask<K,V,U>
5008	>	extends BulkTask<K,V,U> {
5009	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5010	>	final AtomicReference<U> result;
5011	>	SearchEntriesTask
5012	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5013	>	Function<Entry<K,V>, ? extends U> searchFunction,
5014	>	AtomicReference<U> result) {
5015	>	super(p, b, i, f, t);
5016	>	this.searchFunction = searchFunction; this.result = result;
5017	>	}
5018	>	public final U getRawResult() { return result.get(); }
5019	>	public final void compute() {
5020	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5021	>	final AtomicReference<U> result;
5022	>	if ((searchFunction = this.searchFunction) != null &&
5023	>	(result = this.result) != null) {
5024	>	for (int i = baseIndex, f, h; batch > 0 &&
5025	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5026	>	if (result.get() != null)
5027	>	return;
5028	>	addToPendingCount(1);
5029	>	new SearchEntriesTask<K,V,U>
5030	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5031	>	searchFunction, result).fork();
5032	>	}
5033	>	while (result.get() == null) {
5034	>	U u;
5035	>	Node<K,V> p;
5036	>	if ((p = advance()) == null) {
5037	>	propagateCompletion();
5038	>	break;
5039	>	}
5040	>	if ((u = searchFunction.apply(p)) != null) {
5041	>	if (result.compareAndSet(null, u))
5042	>	quietlyCompleteRoot();
5043	>	return;
5044	>	}
5045	>	}
5046	>	}
5047		}
5048	<	public void clear() {
5049	<	ConcurrentHashMap.this.clear();
5048	>	}
5049	>
5050	>	@SuppressWarnings("serial")
5051	>	static final class SearchMappingsTask<K,V,U>
5052	>	extends BulkTask<K,V,U> {
5053	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5054	>	final AtomicReference<U> result;
5055	>	SearchMappingsTask
5056	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5057	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5058	>	AtomicReference<U> result) {
5059	>	super(p, b, i, f, t);
5060	>	this.searchFunction = searchFunction; this.result = result;
5061	>	}
5062	>	public final U getRawResult() { return result.get(); }
5063	>	public final void compute() {
5064	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5065	>	final AtomicReference<U> result;
5066	>	if ((searchFunction = this.searchFunction) != null &&
5067	>	(result = this.result) != null) {
5068	>	for (int i = baseIndex, f, h; batch > 0 &&
5069	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5070	>	if (result.get() != null)
5071	>	return;
5072	>	addToPendingCount(1);
5073	>	new SearchMappingsTask<K,V,U>
5074	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5075	>	searchFunction, result).fork();
5076	>	}
5077	>	while (result.get() == null) {
5078	>	U u;
5079	>	Node<K,V> p;
5080	>	if ((p = advance()) == null) {
5081	>	propagateCompletion();
5082	>	break;
5083	>	}
5084	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5085	>	if (result.compareAndSet(null, u))
5086	>	quietlyCompleteRoot();
5087	>	break;
5088	>	}
5089	>	}
5090	>	}
5091		}
5092	<	public Object[] toArray() {
5093	<	// Since we don't ordinarily have distinct Entry objects, we
5094	<	// must pack elements using exportable SimpleEntry
5095	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
5096	<	for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
5097	<	c.add(new SimpleEntry<K,V>(i.next()));
5098	<	return c.toArray();
5092	>	}
5093	>
5094	>	@SuppressWarnings("serial")
5095	>	static final class ReduceKeysTask<K,V>
5096	>	extends BulkTask<K,V,K> {
5097	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5098	>	K result;
5099	>	ReduceKeysTask<K,V> rights, nextRight;
5100	>	ReduceKeysTask
5101	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5102	>	ReduceKeysTask<K,V> nextRight,
5103	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5104	>	super(p, b, i, f, t); this.nextRight = nextRight;
5105	>	this.reducer = reducer;
5106	>	}
5107	>	public final K getRawResult() { return result; }
5108	>	public final void compute() {
5109	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5110	>	if ((reducer = this.reducer) != null) {
5111	>	for (int i = baseIndex, f, h; batch > 0 &&
5112	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5113	>	addToPendingCount(1);
5114	>	(rights = new ReduceKeysTask<K,V>
5115	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5116	>	rights, reducer)).fork();
5117	>	}
5118	>	K r = null;
5119	>	for (Node<K,V> p; (p = advance()) != null; ) {
5120	>	K u = p.key;
5121	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5122	>	}
5123	>	result = r;
5124	>	CountedCompleter<?> c;
5125	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5126	>	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5127	>	t = (ReduceKeysTask<K,V>)c,
5128	>	s = t.rights;
5129	>	while (s != null) {
5130	>	K tr, sr;
5131	>	if ((sr = s.result) != null)
5132	>	t.result = (((tr = t.result) == null) ? sr :
5133	>	reducer.apply(tr, sr));
5134	>	s = t.rights = s.nextRight;
5135	>	}
5136	>	}
5137	>	}
5138		}
5139	<	public <T> T[] toArray(T[] a) {
5140	<	Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
5141	<	for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
5142	<	c.add(new SimpleEntry<K,V>(i.next()));
5143	<	return c.toArray(a);
5139	>	}
5140	>
5141	>	@SuppressWarnings("serial")
5142	>	static final class ReduceValuesTask<K,V>
5143	>	extends BulkTask<K,V,V> {
5144	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5145	>	V result;
5146	>	ReduceValuesTask<K,V> rights, nextRight;
5147	>	ReduceValuesTask
5148	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5149	>	ReduceValuesTask<K,V> nextRight,
5150	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5151	>	super(p, b, i, f, t); this.nextRight = nextRight;
5152	>	this.reducer = reducer;
5153	>	}
5154	>	public final V getRawResult() { return result; }
5155	>	public final void compute() {
5156	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5157	>	if ((reducer = this.reducer) != null) {
5158	>	for (int i = baseIndex, f, h; batch > 0 &&
5159	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5160	>	addToPendingCount(1);
5161	>	(rights = new ReduceValuesTask<K,V>
5162	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5163	>	rights, reducer)).fork();
5164	>	}
5165	>	V r = null;
5166	>	for (Node<K,V> p; (p = advance()) != null; ) {
5167	>	V v = p.val;
5168	>	r = (r == null) ? v : reducer.apply(r, v);
5169	>	}
5170	>	result = r;
5171	>	CountedCompleter<?> c;
5172	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5173	>	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5174	>	t = (ReduceValuesTask<K,V>)c,
5175	>	s = t.rights;
5176	>	while (s != null) {
5177	>	V tr, sr;
5178	>	if ((sr = s.result) != null)
5179	>	t.result = (((tr = t.result) == null) ? sr :
5180	>	reducer.apply(tr, sr));
5181	>	s = t.rights = s.nextRight;
5182	>	}
5183	>	}
5184	>	}
5185		}
5186	+	}
5187
5188	+	@SuppressWarnings("serial")
5189	+	static final class ReduceEntriesTask<K,V>
5190	+	extends BulkTask<K,V,Map.Entry<K,V>> {
5191	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5192	+	Map.Entry<K,V> result;
5193	+	ReduceEntriesTask<K,V> rights, nextRight;
5194	+	ReduceEntriesTask
5195	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5196	+	ReduceEntriesTask<K,V> nextRight,
5197	+	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5198	+	super(p, b, i, f, t); this.nextRight = nextRight;
5199	+	this.reducer = reducer;
5200	+	}
5201	+	public final Map.Entry<K,V> getRawResult() { return result; }
5202	+	public final void compute() {
5203	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5204	+	if ((reducer = this.reducer) != null) {
5205	+	for (int i = baseIndex, f, h; batch > 0 &&
5206	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5207	+	addToPendingCount(1);
5208	+	(rights = new ReduceEntriesTask<K,V>
5209	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5210	+	rights, reducer)).fork();
5211	+	}
5212	+	Map.Entry<K,V> r = null;
5213	+	for (Node<K,V> p; (p = advance()) != null; )
5214	+	r = (r == null) ? p : reducer.apply(r, p);
5215	+	result = r;
5216	+	CountedCompleter<?> c;
5217	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5218	+	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5219	+	t = (ReduceEntriesTask<K,V>)c,
5220	+	s = t.rights;
5221	+	while (s != null) {
5222	+	Map.Entry<K,V> tr, sr;
5223	+	if ((sr = s.result) != null)
5224	+	t.result = (((tr = t.result) == null) ? sr :
5225	+	reducer.apply(tr, sr));
5226	+	s = t.rights = s.nextRight;
5227	+	}
5228	+	}
5229	+	}
5230	+	}
5231		}
5232
5233	<	/**
5234	<	* This duplicates java.util.AbstractMap.SimpleEntry until this class
5235	<	* is made accessible.
5236	<	*/
5237	<	static class SimpleEntry<K,V> implements Entry<K,V> {
5238	<	K key;
5239	<	V value;
5233	>	@SuppressWarnings("serial")
5234	>	static final class MapReduceKeysTask<K,V,U>
5235	>	extends BulkTask<K,V,U> {
5236	>	final Function<? super K, ? extends U> transformer;
5237	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5238	>	U result;
5239	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5240	>	MapReduceKeysTask
5241	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5242	>	MapReduceKeysTask<K,V,U> nextRight,
5243	>	Function<? super K, ? extends U> transformer,
5244	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5245	>	super(p, b, i, f, t); this.nextRight = nextRight;
5246	>	this.transformer = transformer;
5247	>	this.reducer = reducer;
5248	>	}
5249	>	public final U getRawResult() { return result; }
5250	>	public final void compute() {
5251	>	final Function<? super K, ? extends U> transformer;
5252	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5253	>	if ((transformer = this.transformer) != null &&
5254	>	(reducer = this.reducer) != null) {
5255	>	for (int i = baseIndex, f, h; batch > 0 &&
5256	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5257	>	addToPendingCount(1);
5258	>	(rights = new MapReduceKeysTask<K,V,U>
5259	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5260	>	rights, transformer, reducer)).fork();
5261	>	}
5262	>	U r = null;
5263	>	for (Node<K,V> p; (p = advance()) != null; ) {
5264	>	U u;
5265	>	if ((u = transformer.apply(p.key)) != null)
5266	>	r = (r == null) ? u : reducer.apply(r, u);
5267	>	}
5268	>	result = r;
5269	>	CountedCompleter<?> c;
5270	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5271	>	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5272	>	t = (MapReduceKeysTask<K,V,U>)c,
5273	>	s = t.rights;
5274	>	while (s != null) {
5275	>	U tr, sr;
5276	>	if ((sr = s.result) != null)
5277	>	t.result = (((tr = t.result) == null) ? sr :
5278	>	reducer.apply(tr, sr));
5279	>	s = t.rights = s.nextRight;
5280	>	}
5281	>	}
5282	>	}
5283	>	}
5284	>	}
5285
5286	<	public SimpleEntry(K key, V value) {
5287	<	this.key   = key;
5288	<	this.value = value;
5289	<	}
5286	>	@SuppressWarnings("serial")
5287	>	static final class MapReduceValuesTask<K,V,U>
5288	>	extends BulkTask<K,V,U> {
5289	>	final Function<? super V, ? extends U> transformer;
5290	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5291	>	U result;
5292	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5293	>	MapReduceValuesTask
5294	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5295	>	MapReduceValuesTask<K,V,U> nextRight,
5296	>	Function<? super V, ? extends U> transformer,
5297	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5298	>	super(p, b, i, f, t); this.nextRight = nextRight;
5299	>	this.transformer = transformer;
5300	>	this.reducer = reducer;
5301	>	}
5302	>	public final U getRawResult() { return result; }
5303	>	public final void compute() {
5304	>	final Function<? super V, ? extends U> transformer;
5305	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5306	>	if ((transformer = this.transformer) != null &&
5307	>	(reducer = this.reducer) != null) {
5308	>	for (int i = baseIndex, f, h; batch > 0 &&
5309	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5310	>	addToPendingCount(1);
5311	>	(rights = new MapReduceValuesTask<K,V,U>
5312	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5313	>	rights, transformer, reducer)).fork();
5314	>	}
5315	>	U r = null;
5316	>	for (Node<K,V> p; (p = advance()) != null; ) {
5317	>	U u;
5318	>	if ((u = transformer.apply(p.val)) != null)
5319	>	r = (r == null) ? u : reducer.apply(r, u);
5320	>	}
5321	>	result = r;
5322	>	CountedCompleter<?> c;
5323	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5324	>	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5325	>	t = (MapReduceValuesTask<K,V,U>)c,
5326	>	s = t.rights;
5327	>	while (s != null) {
5328	>	U tr, sr;
5329	>	if ((sr = s.result) != null)
5330	>	t.result = (((tr = t.result) == null) ? sr :
5331	>	reducer.apply(tr, sr));
5332	>	s = t.rights = s.nextRight;
5333	>	}
5334	>	}
5335	>	}
5336	>	}
5337	>	}
5338
5339	<	public SimpleEntry(Entry<K,V> e) {
5340	<	this.key   = e.getKey();
5341	<	this.value = e.getValue();
5342	<	}
5339	>	@SuppressWarnings("serial")
5340	>	static final class MapReduceEntriesTask<K,V,U>
5341	>	extends BulkTask<K,V,U> {
5342	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5343	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5344	>	U result;
5345	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5346	>	MapReduceEntriesTask
5347	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5348	>	MapReduceEntriesTask<K,V,U> nextRight,
5349	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5350	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5351	>	super(p, b, i, f, t); this.nextRight = nextRight;
5352	>	this.transformer = transformer;
5353	>	this.reducer = reducer;
5354	>	}
5355	>	public final U getRawResult() { return result; }
5356	>	public final void compute() {
5357	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5358	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5359	>	if ((transformer = this.transformer) != null &&
5360	>	(reducer = this.reducer) != null) {
5361	>	for (int i = baseIndex, f, h; batch > 0 &&
5362	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5363	>	addToPendingCount(1);
5364	>	(rights = new MapReduceEntriesTask<K,V,U>
5365	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5366	>	rights, transformer, reducer)).fork();
5367	>	}
5368	>	U r = null;
5369	>	for (Node<K,V> p; (p = advance()) != null; ) {
5370	>	U u;
5371	>	if ((u = transformer.apply(p)) != null)
5372	>	r = (r == null) ? u : reducer.apply(r, u);
5373	>	}
5374	>	result = r;
5375	>	CountedCompleter<?> c;
5376	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5377	>	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5378	>	t = (MapReduceEntriesTask<K,V,U>)c,
5379	>	s = t.rights;
5380	>	while (s != null) {
5381	>	U tr, sr;
5382	>	if ((sr = s.result) != null)
5383	>	t.result = (((tr = t.result) == null) ? sr :
5384	>	reducer.apply(tr, sr));
5385	>	s = t.rights = s.nextRight;
5386	>	}
5387	>	}
5388	>	}
5389	>	}
5390	>	}
5391
5392	<	public K getKey() {
5393	<	return key;
5394	<	}
5392	>	@SuppressWarnings("serial")
5393	>	static final class MapReduceMappingsTask<K,V,U>
5394	>	extends BulkTask<K,V,U> {
5395	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5396	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5397	>	U result;
5398	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5399	>	MapReduceMappingsTask
5400	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5401	>	MapReduceMappingsTask<K,V,U> nextRight,
5402	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5403	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5404	>	super(p, b, i, f, t); this.nextRight = nextRight;
5405	>	this.transformer = transformer;
5406	>	this.reducer = reducer;
5407	>	}
5408	>	public final U getRawResult() { return result; }
5409	>	public final void compute() {
5410	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5411	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5412	>	if ((transformer = this.transformer) != null &&
5413	>	(reducer = this.reducer) != null) {
5414	>	for (int i = baseIndex, f, h; batch > 0 &&
5415	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5416	>	addToPendingCount(1);
5417	>	(rights = new MapReduceMappingsTask<K,V,U>
5418	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5419	>	rights, transformer, reducer)).fork();
5420	>	}
5421	>	U r = null;
5422	>	for (Node<K,V> p; (p = advance()) != null; ) {
5423	>	U u;
5424	>	if ((u = transformer.apply(p.key, p.val)) != null)
5425	>	r = (r == null) ? u : reducer.apply(r, u);
5426	>	}
5427	>	result = r;
5428	>	CountedCompleter<?> c;
5429	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5430	>	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5431	>	t = (MapReduceMappingsTask<K,V,U>)c,
5432	>	s = t.rights;
5433	>	while (s != null) {
5434	>	U tr, sr;
5435	>	if ((sr = s.result) != null)
5436	>	t.result = (((tr = t.result) == null) ? sr :
5437	>	reducer.apply(tr, sr));
5438	>	s = t.rights = s.nextRight;
5439	>	}
5440	>	}
5441	>	}
5442	>	}
5443	>	}
5444
5445	<	public V getValue() {
5446	<	return value;
5447	<	}
5445	>	@SuppressWarnings("serial")
5446	>	static final class MapReduceKeysToDoubleTask<K,V>
5447	>	extends BulkTask<K,V,Double> {
5448	>	final ToDoubleFunction<? super K> transformer;
5449	>	final DoubleBinaryOperator reducer;
5450	>	final double basis;
5451	>	double result;
5452	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5453	>	MapReduceKeysToDoubleTask
5454	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5455	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5456	>	ToDoubleFunction<? super K> transformer,
5457	>	double basis,
5458	>	DoubleBinaryOperator reducer) {
5459	>	super(p, b, i, f, t); this.nextRight = nextRight;
5460	>	this.transformer = transformer;
5461	>	this.basis = basis; this.reducer = reducer;
5462	>	}
5463	>	public final Double getRawResult() { return result; }
5464	>	public final void compute() {
5465	>	final ToDoubleFunction<? super K> transformer;
5466	>	final DoubleBinaryOperator reducer;
5467	>	if ((transformer = this.transformer) != null &&
5468	>	(reducer = this.reducer) != null) {
5469	>	double r = this.basis;
5470	>	for (int i = baseIndex, f, h; batch > 0 &&
5471	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5472	>	addToPendingCount(1);
5473	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5474	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5475	>	rights, transformer, r, reducer)).fork();
5476	>	}
5477	>	for (Node<K,V> p; (p = advance()) != null; )
5478	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5479	>	result = r;
5480	>	CountedCompleter<?> c;
5481	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5482	>	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5483	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5484	>	s = t.rights;
5485	>	while (s != null) {
5486	>	t.result = reducer.applyAsDouble(t.result, s.result);
5487	>	s = t.rights = s.nextRight;
5488	>	}
5489	>	}
5490	>	}
5491	>	}
5492	>	}
5493
5494	<	public V setValue(V value) {
5495	<	V oldValue = this.value;
5496	<	this.value = value;
5497	<	return oldValue;
5498	<	}
5494	>	@SuppressWarnings("serial")
5495	>	static final class MapReduceValuesToDoubleTask<K,V>
5496	>	extends BulkTask<K,V,Double> {
5497	>	final ToDoubleFunction<? super V> transformer;
5498	>	final DoubleBinaryOperator reducer;
5499	>	final double basis;
5500	>	double result;
5501	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5502	>	MapReduceValuesToDoubleTask
5503	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5504	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5505	>	ToDoubleFunction<? super V> transformer,
5506	>	double basis,
5507	>	DoubleBinaryOperator reducer) {
5508	>	super(p, b, i, f, t); this.nextRight = nextRight;
5509	>	this.transformer = transformer;
5510	>	this.basis = basis; this.reducer = reducer;
5511	>	}
5512	>	public final Double getRawResult() { return result; }
5513	>	public final void compute() {
5514	>	final ToDoubleFunction<? super V> transformer;
5515	>	final DoubleBinaryOperator reducer;
5516	>	if ((transformer = this.transformer) != null &&
5517	>	(reducer = this.reducer) != null) {
5518	>	double r = this.basis;
5519	>	for (int i = baseIndex, f, h; batch > 0 &&
5520	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5521	>	addToPendingCount(1);
5522	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5523	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5524	>	rights, transformer, r, reducer)).fork();
5525	>	}
5526	>	for (Node<K,V> p; (p = advance()) != null; )
5527	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5528	>	result = r;
5529	>	CountedCompleter<?> c;
5530	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5531	>	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5532	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5533	>	s = t.rights;
5534	>	while (s != null) {
5535	>	t.result = reducer.applyAsDouble(t.result, s.result);
5536	>	s = t.rights = s.nextRight;
5537	>	}
5538	>	}
5539	>	}
5540	>	}
5541	>	}
5542
5543	<	public boolean equals(Object o) {
5544	<	if (!(o instanceof Map.Entry))
5545	<	return false;
5546	<	Map.Entry e = (Map.Entry)o;
5547	<	return eq(key, e.getKey()) && eq(value, e.getValue());
5548	<	}
5543	>	@SuppressWarnings("serial")
5544	>	static final class MapReduceEntriesToDoubleTask<K,V>
5545	>	extends BulkTask<K,V,Double> {
5546	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5547	>	final DoubleBinaryOperator reducer;
5548	>	final double basis;
5549	>	double result;
5550	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5551	>	MapReduceEntriesToDoubleTask
5552	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5553	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5554	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5555	>	double basis,
5556	>	DoubleBinaryOperator reducer) {
5557	>	super(p, b, i, f, t); this.nextRight = nextRight;
5558	>	this.transformer = transformer;
5559	>	this.basis = basis; this.reducer = reducer;
5560	>	}
5561	>	public final Double getRawResult() { return result; }
5562	>	public final void compute() {
5563	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5564	>	final DoubleBinaryOperator reducer;
5565	>	if ((transformer = this.transformer) != null &&
5566	>	(reducer = this.reducer) != null) {
5567	>	double r = this.basis;
5568	>	for (int i = baseIndex, f, h; batch > 0 &&
5569	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5570	>	addToPendingCount(1);
5571	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5572	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5573	>	rights, transformer, r, reducer)).fork();
5574	>	}
5575	>	for (Node<K,V> p; (p = advance()) != null; )
5576	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5577	>	result = r;
5578	>	CountedCompleter<?> c;
5579	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5580	>	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5581	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5582	>	s = t.rights;
5583	>	while (s != null) {
5584	>	t.result = reducer.applyAsDouble(t.result, s.result);
5585	>	s = t.rights = s.nextRight;
5586	>	}
5587	>	}
5588	>	}
5589	>	}
5590	>	}
5591
5592	<	public int hashCode() {
5593	<	return ((key   == null)   ? 0 :   key.hashCode()) ^
5594	<	((value == null)   ? 0 : value.hashCode());
5595	<	}
5592	>	@SuppressWarnings("serial")
5593	>	static final class MapReduceMappingsToDoubleTask<K,V>
5594	>	extends BulkTask<K,V,Double> {
5595	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5596	>	final DoubleBinaryOperator reducer;
5597	>	final double basis;
5598	>	double result;
5599	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5600	>	MapReduceMappingsToDoubleTask
5601	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5602	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5603	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5604	>	double basis,
5605	>	DoubleBinaryOperator reducer) {
5606	>	super(p, b, i, f, t); this.nextRight = nextRight;
5607	>	this.transformer = transformer;
5608	>	this.basis = basis; this.reducer = reducer;
5609	>	}
5610	>	public final Double getRawResult() { return result; }
5611	>	public final void compute() {
5612	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5613	>	final DoubleBinaryOperator reducer;
5614	>	if ((transformer = this.transformer) != null &&
5615	>	(reducer = this.reducer) != null) {
5616	>	double r = this.basis;
5617	>	for (int i = baseIndex, f, h; batch > 0 &&
5618	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5619	>	addToPendingCount(1);
5620	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5621	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5622	>	rights, transformer, r, reducer)).fork();
5623	>	}
5624	>	for (Node<K,V> p; (p = advance()) != null; )
5625	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5626	>	result = r;
5627	>	CountedCompleter<?> c;
5628	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5629	>	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5630	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5631	>	s = t.rights;
5632	>	while (s != null) {
5633	>	t.result = reducer.applyAsDouble(t.result, s.result);
5634	>	s = t.rights = s.nextRight;
5635	>	}
5636	>	}
5637	>	}
5638	>	}
5639	>	}
5640
5641	<	public String toString() {
5642	<	return key + "=" + value;
5643	<	}
5641	>	@SuppressWarnings("serial")
5642	>	static final class MapReduceKeysToLongTask<K,V>
5643	>	extends BulkTask<K,V,Long> {
5644	>	final ToLongFunction<? super K> transformer;
5645	>	final LongBinaryOperator reducer;
5646	>	final long basis;
5647	>	long result;
5648	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5649	>	MapReduceKeysToLongTask
5650	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5651	>	MapReduceKeysToLongTask<K,V> nextRight,
5652	>	ToLongFunction<? super K> transformer,
5653	>	long basis,
5654	>	LongBinaryOperator reducer) {
5655	>	super(p, b, i, f, t); this.nextRight = nextRight;
5656	>	this.transformer = transformer;
5657	>	this.basis = basis; this.reducer = reducer;
5658	>	}
5659	>	public final Long getRawResult() { return result; }
5660	>	public final void compute() {
5661	>	final ToLongFunction<? super K> transformer;
5662	>	final LongBinaryOperator reducer;
5663	>	if ((transformer = this.transformer) != null &&
5664	>	(reducer = this.reducer) != null) {
5665	>	long r = this.basis;
5666	>	for (int i = baseIndex, f, h; batch > 0 &&
5667	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5668	>	addToPendingCount(1);
5669	>	(rights = new MapReduceKeysToLongTask<K,V>
5670	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5671	>	rights, transformer, r, reducer)).fork();
5672	>	}
5673	>	for (Node<K,V> p; (p = advance()) != null; )
5674	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5675	>	result = r;
5676	>	CountedCompleter<?> c;
5677	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5678	>	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5679	>	t = (MapReduceKeysToLongTask<K,V>)c,
5680	>	s = t.rights;
5681	>	while (s != null) {
5682	>	t.result = reducer.applyAsLong(t.result, s.result);
5683	>	s = t.rights = s.nextRight;
5684	>	}
5685	>	}
5686	>	}
5687	>	}
5688	>	}
5689
5690	<	private static boolean eq(Object o1, Object o2) {
5691	<	return (o1 == null ? o2 == null : o1.equals(o2));
5690	>	@SuppressWarnings("serial")
5691	>	static final class MapReduceValuesToLongTask<K,V>
5692	>	extends BulkTask<K,V,Long> {
5693	>	final ToLongFunction<? super V> transformer;
5694	>	final LongBinaryOperator reducer;
5695	>	final long basis;
5696	>	long result;
5697	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5698	>	MapReduceValuesToLongTask
5699	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5700	>	MapReduceValuesToLongTask<K,V> nextRight,
5701	>	ToLongFunction<? super V> transformer,
5702	>	long basis,
5703	>	LongBinaryOperator reducer) {
5704	>	super(p, b, i, f, t); this.nextRight = nextRight;
5705	>	this.transformer = transformer;
5706	>	this.basis = basis; this.reducer = reducer;
5707	>	}
5708	>	public final Long getRawResult() { return result; }
5709	>	public final void compute() {
5710	>	final ToLongFunction<? super V> transformer;
5711	>	final LongBinaryOperator reducer;
5712	>	if ((transformer = this.transformer) != null &&
5713	>	(reducer = this.reducer) != null) {
5714	>	long r = this.basis;
5715	>	for (int i = baseIndex, f, h; batch > 0 &&
5716	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5717	>	addToPendingCount(1);
5718	>	(rights = new MapReduceValuesToLongTask<K,V>
5719	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5720	>	rights, transformer, r, reducer)).fork();
5721	>	}
5722	>	for (Node<K,V> p; (p = advance()) != null; )
5723	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5724	>	result = r;
5725	>	CountedCompleter<?> c;
5726	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5727	>	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5728	>	t = (MapReduceValuesToLongTask<K,V>)c,
5729	>	s = t.rights;
5730	>	while (s != null) {
5731	>	t.result = reducer.applyAsLong(t.result, s.result);
5732	>	s = t.rights = s.nextRight;
5733	>	}
5734	>	}
5735	>	}
5736		}
5737		}
5738
5739	<	/* ---------------- Serialization Support -------------- */
5739	>	@SuppressWarnings("serial")
5740	>	static final class MapReduceEntriesToLongTask<K,V>
5741	>	extends BulkTask<K,V,Long> {
5742	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5743	>	final LongBinaryOperator reducer;
5744	>	final long basis;
5745	>	long result;
5746	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5747	>	MapReduceEntriesToLongTask
5748	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5749	>	MapReduceEntriesToLongTask<K,V> nextRight,
5750	>	ToLongFunction<Map.Entry<K,V>> transformer,
5751	>	long basis,
5752	>	LongBinaryOperator reducer) {
5753	>	super(p, b, i, f, t); this.nextRight = nextRight;
5754	>	this.transformer = transformer;
5755	>	this.basis = basis; this.reducer = reducer;
5756	>	}
5757	>	public final Long getRawResult() { return result; }
5758	>	public final void compute() {
5759	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5760	>	final LongBinaryOperator reducer;
5761	>	if ((transformer = this.transformer) != null &&
5762	>	(reducer = this.reducer) != null) {
5763	>	long r = this.basis;
5764	>	for (int i = baseIndex, f, h; batch > 0 &&
5765	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5766	>	addToPendingCount(1);
5767	>	(rights = new MapReduceEntriesToLongTask<K,V>
5768	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5769	>	rights, transformer, r, reducer)).fork();
5770	>	}
5771	>	for (Node<K,V> p; (p = advance()) != null; )
5772	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5773	>	result = r;
5774	>	CountedCompleter<?> c;
5775	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5776	>	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5777	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5778	>	s = t.rights;
5779	>	while (s != null) {
5780	>	t.result = reducer.applyAsLong(t.result, s.result);
5781	>	s = t.rights = s.nextRight;
5782	>	}
5783	>	}
5784	>	}
5785	>	}
5786	>	}
5787
5788	<	/**
5789	<	* Save the state of the <tt>ConcurrentHashMap</tt>
5790	<	* instance to a stream (i.e.,
5791	<	* serialize it).
5792	<	* @param s the stream
5793	<	* @serialData
5794	<	* the key (Object) and value (Object)
5795	<	* for each key-value mapping, followed by a null pair.
5796	<	* The key-value mappings are emitted in no particular order.
5797	<	*/
5798	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
5799	<	s.defaultWriteObject();
5788	>	@SuppressWarnings("serial")
5789	>	static final class MapReduceMappingsToLongTask<K,V>
5790	>	extends BulkTask<K,V,Long> {
5791	>	final ToLongBiFunction<? super K, ? super V> transformer;
5792	>	final LongBinaryOperator reducer;
5793	>	final long basis;
5794	>	long result;
5795	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5796	>	MapReduceMappingsToLongTask
5797	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5798	>	MapReduceMappingsToLongTask<K,V> nextRight,
5799	>	ToLongBiFunction<? super K, ? super V> transformer,
5800	>	long basis,
5801	>	LongBinaryOperator reducer) {
5802	>	super(p, b, i, f, t); this.nextRight = nextRight;
5803	>	this.transformer = transformer;
5804	>	this.basis = basis; this.reducer = reducer;
5805	>	}
5806	>	public final Long getRawResult() { return result; }
5807	>	public final void compute() {
5808	>	final ToLongBiFunction<? super K, ? super V> transformer;
5809	>	final LongBinaryOperator reducer;
5810	>	if ((transformer = this.transformer) != null &&
5811	>	(reducer = this.reducer) != null) {
5812	>	long r = this.basis;
5813	>	for (int i = baseIndex, f, h; batch > 0 &&
5814	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5815	>	addToPendingCount(1);
5816	>	(rights = new MapReduceMappingsToLongTask<K,V>
5817	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5818	>	rights, transformer, r, reducer)).fork();
5819	>	}
5820	>	for (Node<K,V> p; (p = advance()) != null; )
5821	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
5822	>	result = r;
5823	>	CountedCompleter<?> c;
5824	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5825	>	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5826	>	t = (MapReduceMappingsToLongTask<K,V>)c,
5827	>	s = t.rights;
5828	>	while (s != null) {
5829	>	t.result = reducer.applyAsLong(t.result, s.result);
5830	>	s = t.rights = s.nextRight;
5831	>	}
5832	>	}
5833	>	}
5834	>	}
5835	>	}
5836
5837	<	for (int k = 0; k < segments.length; ++k) {
5838	<	Segment<K,V> seg = (Segment<K,V>)segments[k];
5839	<	seg.lock();
5840	<	try {
5841	<	HashEntry[] tab = seg.table;
5842	<	for (int i = 0; i < tab.length; ++i) {
5843	<	for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
5844	<	s.writeObject(e.key);
5845	<	s.writeObject(e.value);
5837	>	@SuppressWarnings("serial")
5838	>	static final class MapReduceKeysToIntTask<K,V>
5839	>	extends BulkTask<K,V,Integer> {
5840	>	final ToIntFunction<? super K> transformer;
5841	>	final IntBinaryOperator reducer;
5842	>	final int basis;
5843	>	int result;
5844	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
5845	>	MapReduceKeysToIntTask
5846	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5847	>	MapReduceKeysToIntTask<K,V> nextRight,
5848	>	ToIntFunction<? super K> transformer,
5849	>	int basis,
5850	>	IntBinaryOperator reducer) {
5851	>	super(p, b, i, f, t); this.nextRight = nextRight;
5852	>	this.transformer = transformer;
5853	>	this.basis = basis; this.reducer = reducer;
5854	>	}
5855	>	public final Integer getRawResult() { return result; }
5856	>	public final void compute() {
5857	>	final ToIntFunction<? super K> transformer;
5858	>	final IntBinaryOperator reducer;
5859	>	if ((transformer = this.transformer) != null &&
5860	>	(reducer = this.reducer) != null) {
5861	>	int r = this.basis;
5862	>	for (int i = baseIndex, f, h; batch > 0 &&
5863	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5864	>	addToPendingCount(1);
5865	>	(rights = new MapReduceKeysToIntTask<K,V>
5866	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5867	>	rights, transformer, r, reducer)).fork();
5868	>	}
5869	>	for (Node<K,V> p; (p = advance()) != null; )
5870	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
5871	>	result = r;
5872	>	CountedCompleter<?> c;
5873	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5874	>	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5875	>	t = (MapReduceKeysToIntTask<K,V>)c,
5876	>	s = t.rights;
5877	>	while (s != null) {
5878	>	t.result = reducer.applyAsInt(t.result, s.result);
5879	>	s = t.rights = s.nextRight;
5880		}
5881		}
1297	–	} finally {
1298	–	seg.unlock();
5882		}
5883		}
1301	–	s.writeObject(null);
1302	–	s.writeObject(null);
5884		}
5885
5886	<	/**
5887	<	* Reconstitute the <tt>ConcurrentHashMap</tt>
5888	<	* instance from a stream (i.e.,
5889	<	* deserialize it).
5890	<	* @param s the stream
5891	<	*/
5892	<	private void readObject(java.io.ObjectInputStream s)
5893	<	throws IOException, ClassNotFoundException  {
5894	<	s.defaultReadObject();
5886	>	@SuppressWarnings("serial")
5887	>	static final class MapReduceValuesToIntTask<K,V>
5888	>	extends BulkTask<K,V,Integer> {
5889	>	final ToIntFunction<? super V> transformer;
5890	>	final IntBinaryOperator reducer;
5891	>	final int basis;
5892	>	int result;
5893	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
5894	>	MapReduceValuesToIntTask
5895	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5896	>	MapReduceValuesToIntTask<K,V> nextRight,
5897	>	ToIntFunction<? super V> transformer,
5898	>	int basis,
5899	>	IntBinaryOperator reducer) {
5900	>	super(p, b, i, f, t); this.nextRight = nextRight;
5901	>	this.transformer = transformer;
5902	>	this.basis = basis; this.reducer = reducer;
5903	>	}
5904	>	public final Integer getRawResult() { return result; }
5905	>	public final void compute() {
5906	>	final ToIntFunction<? super V> transformer;
5907	>	final IntBinaryOperator reducer;
5908	>	if ((transformer = this.transformer) != null &&
5909	>	(reducer = this.reducer) != null) {
5910	>	int r = this.basis;
5911	>	for (int i = baseIndex, f, h; batch > 0 &&
5912	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5913	>	addToPendingCount(1);
5914	>	(rights = new MapReduceValuesToIntTask<K,V>
5915	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5916	>	rights, transformer, r, reducer)).fork();
5917	>	}
5918	>	for (Node<K,V> p; (p = advance()) != null; )
5919	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5920	>	result = r;
5921	>	CountedCompleter<?> c;
5922	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5923	>	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5924	>	t = (MapReduceValuesToIntTask<K,V>)c,
5925	>	s = t.rights;
5926	>	while (s != null) {
5927	>	t.result = reducer.applyAsInt(t.result, s.result);
5928	>	s = t.rights = s.nextRight;
5929	>	}
5930	>	}
5931	>	}
5932	>	}
5933	>	}
5934	>
5935	>	@SuppressWarnings("serial")
5936	>	static final class MapReduceEntriesToIntTask<K,V>
5937	>	extends BulkTask<K,V,Integer> {
5938	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5939	>	final IntBinaryOperator reducer;
5940	>	final int basis;
5941	>	int result;
5942	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5943	>	MapReduceEntriesToIntTask
5944	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5945	>	MapReduceEntriesToIntTask<K,V> nextRight,
5946	>	ToIntFunction<Map.Entry<K,V>> transformer,
5947	>	int basis,
5948	>	IntBinaryOperator reducer) {
5949	>	super(p, b, i, f, t); this.nextRight = nextRight;
5950	>	this.transformer = transformer;
5951	>	this.basis = basis; this.reducer = reducer;
5952	>	}
5953	>	public final Integer getRawResult() { return result; }
5954	>	public final void compute() {
5955	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5956	>	final IntBinaryOperator reducer;
5957	>	if ((transformer = this.transformer) != null &&
5958	>	(reducer = this.reducer) != null) {
5959	>	int r = this.basis;
5960	>	for (int i = baseIndex, f, h; batch > 0 &&
5961	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5962	>	addToPendingCount(1);
5963	>	(rights = new MapReduceEntriesToIntTask<K,V>
5964	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5965	>	rights, transformer, r, reducer)).fork();
5966	>	}
5967	>	for (Node<K,V> p; (p = advance()) != null; )
5968	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
5969	>	result = r;
5970	>	CountedCompleter<?> c;
5971	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5972	>	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
5973	>	t = (MapReduceEntriesToIntTask<K,V>)c,
5974	>	s = t.rights;
5975	>	while (s != null) {
5976	>	t.result = reducer.applyAsInt(t.result, s.result);
5977	>	s = t.rights = s.nextRight;
5978	>	}
5979	>	}
5980	>	}
5981	>	}
5982	>	}
5983
5984	<	// Initialize each segment to be minimally sized, and let grow.
5985	<	for (int i = 0; i < segments.length; ++i) {
5986	<	segments[i].setTable(new HashEntry[1]);
5984	>	@SuppressWarnings("serial")
5985	>	static final class MapReduceMappingsToIntTask<K,V>
5986	>	extends BulkTask<K,V,Integer> {
5987	>	final ToIntBiFunction<? super K, ? super V> transformer;
5988	>	final IntBinaryOperator reducer;
5989	>	final int basis;
5990	>	int result;
5991	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
5992	>	MapReduceMappingsToIntTask
5993	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5994	>	MapReduceMappingsToIntTask<K,V> nextRight,
5995	>	ToIntBiFunction<? super K, ? super V> transformer,
5996	>	int basis,
5997	>	IntBinaryOperator reducer) {
5998	>	super(p, b, i, f, t); this.nextRight = nextRight;
5999	>	this.transformer = transformer;
6000	>	this.basis = basis; this.reducer = reducer;
6001	>	}
6002	>	public final Integer getRawResult() { return result; }
6003	>	public final void compute() {
6004	>	final ToIntBiFunction<? super K, ? super V> transformer;
6005	>	final IntBinaryOperator reducer;
6006	>	if ((transformer = this.transformer) != null &&
6007	>	(reducer = this.reducer) != null) {
6008	>	int r = this.basis;
6009	>	for (int i = baseIndex, f, h; batch > 0 &&
6010	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6011	>	addToPendingCount(1);
6012	>	(rights = new MapReduceMappingsToIntTask<K,V>
6013	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6014	>	rights, transformer, r, reducer)).fork();
6015	>	}
6016	>	for (Node<K,V> p; (p = advance()) != null; )
6017	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6018	>	result = r;
6019	>	CountedCompleter<?> c;
6020	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6021	>	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6022	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6023	>	s = t.rights;
6024	>	while (s != null) {
6025	>	t.result = reducer.applyAsInt(t.result, s.result);
6026	>	s = t.rights = s.nextRight;
6027	>	}
6028	>	}
6029	>	}
6030		}
6031	+	}
6032
6033	<	// Read the keys and values, and put the mappings in the table
6034	<	for (;;) {
6035	<	K key = (K) s.readObject();
6036	<	V value = (V) s.readObject();
6037	<	if (key == null)
6038	<	break;
6039	<	put(key, value);
6033	>	// Unsafe mechanics
6034	>	private static final sun.misc.Unsafe U;
6035	>	private static final long SIZECTL;
6036	>	private static final long TRANSFERINDEX;
6037	>	private static final long TRANSFERORIGIN;
6038	>	private static final long BASECOUNT;
6039	>	private static final long CELLSBUSY;
6040	>	private static final long CELLVALUE;
6041	>	private static final long ABASE;
6042	>	private static final int ASHIFT;
6043	>
6044	>	static {
6045	>	try {
6046	>	U = sun.misc.Unsafe.getUnsafe();
6047	>	Class<?> k = ConcurrentHashMap.class;
6048	>	SIZECTL = U.objectFieldOffset
6049	>	(k.getDeclaredField("sizeCtl"));
6050	>	TRANSFERINDEX = U.objectFieldOffset
6051	>	(k.getDeclaredField("transferIndex"));
6052	>	TRANSFERORIGIN = U.objectFieldOffset
6053	>	(k.getDeclaredField("transferOrigin"));
6054	>	BASECOUNT = U.objectFieldOffset
6055	>	(k.getDeclaredField("baseCount"));
6056	>	CELLSBUSY = U.objectFieldOffset
6057	>	(k.getDeclaredField("cellsBusy"));
6058	>	Class<?> ck = CounterCell.class;
6059	>	CELLVALUE = U.objectFieldOffset
6060	>	(ck.getDeclaredField("value"));
6061	>	Class<?> sc = Node[].class;
6062	>	ABASE = U.arrayBaseOffset(sc);
6063	>	int scale = U.arrayIndexScale(sc);
6064	>	if ((scale & (scale - 1)) != 0)
6065	>	throw new Error("data type scale not a power of two");
6066	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6067	>	} catch (Exception e) {
6068	>	throw new Error(e);
6069		}
6070		}
6071		}
1330	–

Diff Legend

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