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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.92 by dl, Sat Dec 2 20:55:01 2006 UTC vs.
Revision 1.236 by dl, Thu Jul 11 10:38:10 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, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
16	>	import java.util.Comparator;
17	>	import java.util.ConcurrentModificationException;
18	>	import java.util.Enumeration;
19	>	import java.util.HashMap;
20	>	import java.util.Hashtable;
21	>	import java.util.Iterator;
22	>	import java.util.Map;
23	>	import java.util.NoSuchElementException;
24	>	import java.util.Set;
25	>	import java.util.Spliterator;
26	>	import java.util.concurrent.ConcurrentMap;
27	>	import java.util.concurrent.ForkJoinPool;
28	>	import java.util.concurrent.atomic.AtomicReference;
29	>	import java.util.concurrent.locks.LockSupport;
30	>	import java.util.concurrent.locks.ReentrantLock;
31	>	import java.util.function.BiConsumer;
32	>	import java.util.function.BiFunction;
33	>	import java.util.function.BinaryOperator;
34	>	import java.util.function.Consumer;
35	>	import java.util.function.DoubleBinaryOperator;
36	>	import java.util.function.Function;
37	>	import java.util.function.IntBinaryOperator;
38	>	import java.util.function.LongBinaryOperator;
39	>	import java.util.function.ToDoubleBiFunction;
40	>	import java.util.function.ToDoubleFunction;
41	>	import java.util.function.ToIntBiFunction;
42	>	import java.util.function.ToIntFunction;
43	>	import java.util.function.ToLongBiFunction;
44	>	import java.util.function.ToLongFunction;
45	>	import java.util.stream.Stream;
46
47		/**
48		* A hash table supporting full concurrency of retrievals and
49	<	* adjustable expected concurrency for updates. This class obeys the
49	>	* high expected concurrency for updates. This class obeys the
50		* same functional specification as {@link java.util.Hashtable}, and
51		* includes versions of methods corresponding to each method of
52	<	* <tt>Hashtable</tt>. However, even though all operations are
52	>	* {@code Hashtable}. However, even though all operations are
53		* thread-safe, retrieval operations do <em>not</em> entail locking,
54		* and there is <em>not</em> any support for locking the entire table
55		* in a way that prevents all access.  This class is fully
56	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
56	>	* interoperable with {@code Hashtable} in programs that rely on its
57		* thread safety but not on its synchronization details.
58		*
59	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
60	<	* block, so may overlap with update operations (including
61	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
62	<	* of the most recently <em>completed</em> update operations holding
63	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
64	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
65	<	* removal of only some entries.  Similarly, Iterators and
66	<	* Enumerations return elements reflecting the state of the hash table
67	<	* at some point at or since the creation of the iterator/enumeration.
68	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
69	<	* However, iterators are 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 <tt>16</tt>), 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 and
84	<	* all others will only read. Also, resizing this or any other kind of
85	<	* hash table is a relatively slow operation, so, when possible, it is
86	<	* a good idea to provide estimates of expected table sizes in
87	<	* constructors.
59	>	* <p>Retrieval operations (including {@code get}) generally do not
60	>	* block, so may overlap with update operations (including {@code put}
61	>	* and {@code remove}). Retrievals reflect the results of the most
62	>	* recently <em>completed</em> update operations holding upon their
63	>	* onset. (More formally, an update operation for a given key bears a
64	>	* <em>happens-before</em> relation with any (non-null) retrieval for
65	>	* that key reporting the updated value.)  For aggregate operations
66	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
67	>	* reflect insertion or removal of only some entries.  Similarly,
68	>	* Iterators and Enumerations return elements reflecting the state of
69	>	* the hash table at some point at or since the creation of the
70	>	* iterator/enumeration.  They do <em>not</em> throw {@link
71	>	* ConcurrentModificationException}.  However, iterators are designed
72	>	* to be used by only one thread at a time.  Bear in mind that the
73	>	* results of aggregate status methods including {@code size}, {@code
74	>	* isEmpty}, and {@code containsValue} are typically useful only when
75	>	* a map is not undergoing concurrent updates in other threads.
76	>	* Otherwise the results of these methods reflect transient states
77	>	* that may be adequate for monitoring or estimation purposes, but not
78	>	* for program control.
79	>	*
80	>	* <p>The table is dynamically expanded when there are too many
81	>	* collisions (i.e., keys that have distinct hash codes but fall into
82	>	* the same slot modulo the table size), with the expected average
83	>	* effect of maintaining roughly two bins per mapping (corresponding
84	>	* to a 0.75 load factor threshold for resizing). There may be much
85	>	* variance around this average as mappings are added and removed, but
86	>	* overall, this maintains a commonly accepted time/space tradeoff for
87	>	* hash tables.  However, resizing this or any other kind of hash
88	>	* table may be a relatively slow operation. When possible, it is a
89	>	* good idea to provide a size estimate as an optional {@code
90	>	* initialCapacity} constructor argument. An additional optional
91	>	* {@code loadFactor} constructor argument provides a further means of
92	>	* customizing initial table capacity by specifying the table density
93	>	* to be used in calculating the amount of space to allocate for the
94	>	* given number of elements.  Also, for compatibility with previous
95	>	* versions of this class, constructors may optionally specify an
96	>	* expected {@code concurrencyLevel} as an additional hint for
97	>	* internal sizing.  Note that using many keys with exactly the same
98	>	* {@code hashCode()} is a sure way to slow down performance of any
99	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
100	>	* this class may use comparison order among keys to help break ties.
101	>	*
102	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
103	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
104	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
105	>	* mapped values are (perhaps transiently) not used or all take the
106	>	* same mapping value.
107	>	*
108	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
109	>	* form of histogram or multiset) by using {@link
110	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
111	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
112	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
113	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
114		*
115		* <p>This class and its views and iterators implement all of the
116		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
117		* interfaces.
118		*
119	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
120	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
119	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
120	>	* does <em>not</em> allow {@code null} to be used as a key or value.
121	>	*
122	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
123	>	* operations that, unlike most {@link Stream} methods, are designed
124	>	* to be safely, and often sensibly, applied even with maps that are
125	>	* being concurrently updated by other threads; for example, when
126	>	* computing a snapshot summary of the values in a shared registry.
127	>	* There are three kinds of operation, each with four forms, accepting
128	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
129	>	* and/or return values. Because the elements of a ConcurrentHashMap
130	>	* are not ordered in any particular way, and may be processed in
131	>	* different orders in different parallel executions, the correctness
132	>	* of supplied functions should not depend on any ordering, or on any
133	>	* other objects or values that may transiently change while
134	>	* computation is in progress; and except for forEach actions, should
135	>	* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
136	>	* objects do not support method {@code setValue}.
137	>	*
138	>	* <ul>
139	>	* <li> forEach: Perform a given action on each element.
140	>	* A variant form applies a given transformation on each element
141	>	* before performing the action.</li>
142	>	*
143	>	* <li> search: Return the first available non-null result of
144	>	* applying a given function on each element; skipping further
145	>	* search when a result is found.</li>
146	>	*
147	>	* <li> reduce: Accumulate each element.  The supplied reduction
148	>	* function cannot rely on ordering (more formally, it should be
149	>	* both associative and commutative).  There are five variants:
150	>	*
151	>	* <ul>
152	>	*
153	>	* <li> Plain reductions. (There is not a form of this method for
154	>	* (key, value) function arguments since there is no corresponding
155	>	* return type.)</li>
156	>	*
157	>	* <li> Mapped reductions that accumulate the results of a given
158	>	* function applied to each element.</li>
159	>	*
160	>	* <li> Reductions to scalar doubles, longs, and ints, using a
161	>	* given basis value.</li>
162	>	*
163	>	* </ul>
164	>	* </li>
165	>	* </ul>
166	>	*
167	>	* <p>These bulk operations accept a {@code parallelismThreshold}
168	>	* argument. Methods proceed sequentially if the current map size is
169	>	* estimated to be less than the given threshold. Using a value of
170	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
171	>	* of {@code 1} results in maximal parallelism by partitioning into
172	>	* enough subtasks to fully utilize the {@link
173	>	* ForkJoinPool#commonPool()} that is used for all parallel
174	>	* computations. Normally, you would initially choose one of these
175	>	* extreme values, and then measure performance of using in-between
176	>	* values that trade off overhead versus throughput.
177	>	*
178	>	* <p>The concurrency properties of bulk operations follow
179	>	* from those of ConcurrentHashMap: Any non-null result returned
180	>	* from {@code get(key)} and related access methods bears a
181	>	* happens-before relation with the associated insertion or
182	>	* update.  The result of any bulk operation reflects the
183	>	* composition of these per-element relations (but is not
184	>	* necessarily atomic with respect to the map as a whole unless it
185	>	* is somehow known to be quiescent).  Conversely, because keys
186	>	* and values in the map are never null, null serves as a reliable
187	>	* atomic indicator of the current lack of any result.  To
188	>	* maintain this property, null serves as an implicit basis for
189	>	* all non-scalar reduction operations. For the double, long, and
190	>	* int versions, the basis should be one that, when combined with
191	>	* any other value, returns that other value (more formally, it
192	>	* should be the identity element for the reduction). Most common
193	>	* reductions have these properties; for example, computing a sum
194	>	* with basis 0 or a minimum with basis MAX_VALUE.
195	>	*
196	>	* <p>Search and transformation functions provided as arguments
197	>	* should similarly return null to indicate the lack of any result
198	>	* (in which case it is not used). In the case of mapped
199	>	* reductions, this also enables transformations to serve as
200	>	* filters, returning null (or, in the case of primitive
201	>	* specializations, the identity basis) if the element should not
202	>	* be combined. You can create compound transformations and
203	>	* filterings by composing them yourself under this "null means
204	>	* there is nothing there now" rule before using them in search or
205	>	* reduce operations.
206	>	*
207	>	* <p>Methods accepting and/or returning Entry arguments maintain
208	>	* key-value associations. They may be useful for example when
209	>	* finding the key for the greatest value. Note that "plain" Entry
210	>	* arguments can be supplied using {@code new
211	>	* AbstractMap.SimpleEntry(k,v)}.
212	>	*
213	>	* <p>Bulk operations may complete abruptly, throwing an
214	>	* exception encountered in the application of a supplied
215	>	* function. Bear in mind when handling such exceptions that other
216	>	* concurrently executing functions could also have thrown
217	>	* exceptions, or would have done so if the first exception had
218	>	* not occurred.
219	>	*
220	>	* <p>Speedups for parallel compared to sequential forms are common
221	>	* but not guaranteed.  Parallel operations involving brief functions
222	>	* on small maps may execute more slowly than sequential forms if the
223	>	* underlying work to parallelize the computation is more expensive
224	>	* than the computation itself.  Similarly, parallelization may not
225	>	* lead to much actual parallelism if all processors are busy
226	>	* performing unrelated tasks.
227	>	*
228	>	* <p>All arguments to all task methods must be non-null.
229		*
230		* <p>This class is a member of the
231		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 236 | import java.io.ObjectOutputStream;
236		* @param <K> the type of keys maintained by this map
237		* @param <V> the type of mapped values
238		*/
239	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
74	<	implements ConcurrentMap<K, V>, Serializable {
239	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V> implements ConcurrentMap<K,V>, Serializable {
240		private static final long serialVersionUID = 7249069246763182397L;
241
242		/*
243	<	* The basic strategy is to subdivide the table among Segments,
244	<	* each of which itself is a concurrently readable hash table.
243	>	* Overview:
244	>	*
245	>	* The primary design goal of this hash table is to maintain
246	>	* concurrent readability (typically method get(), but also
247	>	* iterators and related methods) while minimizing update
248	>	* contention. Secondary goals are to keep space consumption about
249	>	* the same or better than java.util.HashMap, and to support high
250	>	* initial insertion rates on an empty table by many threads.
251	>	*
252	>	* This map usually acts as a binned (bucketed) hash table.  Each
253	>	* key-value mapping is held in a Node.  Most nodes are instances
254	>	* of the basic Node class with hash, key, value, and next
255	>	* fields. However, various subclasses exist: TreeNodes are
256	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
257	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
258	>	* of bins during resizing. ReservationNodes are used as
259	>	* placeholders while establishing values in computeIfAbsent and
260	>	* related methods.  The types TreeBin, ForwardingNode, and
261	>	* ReservationNode do not hold normal user keys, values, or
262	>	* hashes, and are readily distinguishable during search etc
263	>	* because they have negative hash fields and null key and value
264	>	* fields. (These special nodes are either uncommon or transient,
265	>	* so the impact of carrying around some unused fields is
266	>	* insignificant.)
267	>	*
268	>	* The table is lazily initialized to a power-of-two size upon the
269	>	* first insertion.  Each bin in the table normally contains a
270	>	* list of Nodes (most often, the list has only zero or one Node).
271	>	* Table accesses require volatile/atomic reads, writes, and
272	>	* CASes.  Because there is no other way to arrange this without
273	>	* adding further indirections, we use intrinsics
274	>	* (sun.misc.Unsafe) operations.
275	>	*
276	>	* We use the top (sign) bit of Node hash fields for control
277	>	* purposes -- it is available anyway because of addressing
278	>	* constraints.  Nodes with negative hash fields are specially
279	>	* handled or ignored in map methods.
280	>	*
281	>	* Insertion (via put or its variants) of the first node in an
282	>	* empty bin is performed by just CASing it to the bin.  This is
283	>	* by far the most common case for put operations under most
284	>	* key/hash distributions.  Other update operations (insert,
285	>	* delete, and replace) require locks.  We do not want to waste
286	>	* the space required to associate a distinct lock object with
287	>	* each bin, so instead use the first node of a bin list itself as
288	>	* a lock. Locking support for these locks relies on builtin
289	>	* "synchronized" monitors.
290	>	*
291	>	* Using the first node of a list as a lock does not by itself
292	>	* suffice though: When a node is locked, any update must first
293	>	* validate that it is still the first node after locking it, and
294	>	* retry if not. Because new nodes are always appended to lists,
295	>	* once a node is first in a bin, it remains first until deleted
296	>	* or the bin becomes invalidated (upon resizing).
297	>	*
298	>	* The main disadvantage of per-bin locks is that other update
299	>	* operations on other nodes in a bin list protected by the same
300	>	* lock can stall, for example when user equals() or mapping
301	>	* functions take a long time.  However, statistically, under
302	>	* random hash codes, this is not a common problem.  Ideally, the
303	>	* frequency of nodes in bins follows a Poisson distribution
304	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
305	>	* parameter of about 0.5 on average, given the resizing threshold
306	>	* of 0.75, although with a large variance because of resizing
307	>	* granularity. Ignoring variance, the expected occurrences of
308	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
309	>	* first values are:
310	>	*
311	>	* 0:    0.60653066
312	>	* 1:    0.30326533
313	>	* 2:    0.07581633
314	>	* 3:    0.01263606
315	>	* 4:    0.00157952
316	>	* 5:    0.00015795
317	>	* 6:    0.00001316
318	>	* 7:    0.00000094
319	>	* 8:    0.00000006
320	>	* more: less than 1 in ten million
321	>	*
322	>	* Lock contention probability for two threads accessing distinct
323	>	* elements is roughly 1 / (8 * #elements) under random hashes.
324	>	*
325	>	* Actual hash code distributions encountered in practice
326	>	* sometimes deviate significantly from uniform randomness.  This
327	>	* includes the case when N > (1<<30), so some keys MUST collide.
328	>	* Similarly for dumb or hostile usages in which multiple keys are
329	>	* designed to have identical hash codes or ones that differs only
330	>	* in masked-out high bits. So we use a secondary strategy that
331	>	* applies when the number of nodes in a bin exceeds a
332	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
333	>	* specialized form of red-black trees), bounding search time to
334	>	* O(log N).  Each search step in a TreeBin is at least twice as
335	>	* slow as in a regular list, but given that N cannot exceed
336	>	* (1<<64) (before running out of addresses) this bounds search
337	>	* steps, lock hold times, etc, to reasonable constants (roughly
338	>	* 100 nodes inspected per operation worst case) so long as keys
339	>	* are Comparable (which is very common -- String, Long, etc).
340	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
341	>	* traversal pointers as regular nodes, so can be traversed in
342	>	* iterators in the same way.
343	>	*
344	>	* The table is resized when occupancy exceeds a percentage
345	>	* threshold (nominally, 0.75, but see below).  Any thread
346	>	* noticing an overfull bin may assist in resizing after the
347	>	* initiating thread allocates and sets up the replacement
348	>	* array. However, rather than stalling, these other threads may
349	>	* proceed with insertions etc.  The use of TreeBins shields us
350	>	* from the worst case effects of overfilling while resizes are in
351	>	* progress.  Resizing proceeds by transferring bins, one by one,
352	>	* from the table to the next table. To enable concurrency, the
353	>	* next table must be (incrementally) prefilled with place-holders
354	>	* serving as reverse forwarders to the old table.  Because we are
355	>	* using power-of-two expansion, the elements from each bin must
356	>	* either stay at same index, or move with a power of two
357	>	* offset. We eliminate unnecessary node creation by catching
358	>	* cases where old nodes can be reused because their next fields
359	>	* won't change.  On average, only about one-sixth of them need
360	>	* cloning when a table doubles. The nodes they replace will be
361	>	* garbage collectable as soon as they are no longer referenced by
362	>	* any reader thread that may be in the midst of concurrently
363	>	* traversing table.  Upon transfer, the old table bin contains
364	>	* only a special forwarding node (with hash field "MOVED") that
365	>	* contains the next table as its key. On encountering a
366	>	* forwarding node, access and update operations restart, using
367	>	* the new table.
368	>	*
369	>	* Each bin transfer requires its bin lock, which can stall
370	>	* waiting for locks while resizing. However, because other
371	>	* threads can join in and help resize rather than contend for
372	>	* locks, average aggregate waits become shorter as resizing
373	>	* progresses.  The transfer operation must also ensure that all
374	>	* accessible bins in both the old and new table are usable by any
375	>	* traversal.  This is arranged by proceeding from the last bin
376	>	* (table.length - 1) up towards the first.  Upon seeing a
377	>	* forwarding node, traversals (see class Traverser) arrange to
378	>	* move to the new table without revisiting nodes.  However, to
379	>	* ensure that no intervening nodes are skipped, bin splitting can
380	>	* only begin after the associated reverse-forwarders are in
381	>	* place.
382	>	*
383	>	* The traversal scheme also applies to partial traversals of
384	>	* ranges of bins (via an alternate Traverser constructor)
385	>	* to support partitioned aggregate operations.  Also, read-only
386	>	* operations give up if ever forwarded to a null table, which
387	>	* provides support for shutdown-style clearing, which is also not
388	>	* currently implemented.
389	>	*
390	>	* Lazy table initialization minimizes footprint until first use,
391	>	* and also avoids resizings when the first operation is from a
392	>	* putAll, constructor with map argument, or deserialization.
393	>	* These cases attempt to override the initial capacity settings,
394	>	* but harmlessly fail to take effect in cases of races.
395	>	*
396	>	* The element count is maintained using a specialization of
397	>	* LongAdder. We need to incorporate a specialization rather than
398	>	* just use a LongAdder in order to access implicit
399	>	* contention-sensing that leads to creation of multiple
400	>	* CounterCells.  The counter mechanics avoid contention on
401	>	* updates but can encounter cache thrashing if read too
402	>	* frequently during concurrent access. To avoid reading so often,
403	>	* resizing under contention is attempted only upon adding to a
404	>	* bin already holding two or more nodes. Under uniform hash
405	>	* distributions, the probability of this occurring at threshold
406	>	* is around 13%, meaning that only about 1 in 8 puts check
407	>	* threshold (and after resizing, many fewer do so).
408	>	*
409	>	* TreeBins use a special form of comparison for search and
410	>	* related operations (which is the main reason we cannot use
411	>	* existing collections such as TreeMaps). TreeBins contain
412	>	* Comparable elements, but may contain others, as well as
413	>	* elements that are Comparable but not necessarily Comparable
414	>	* for the same T, so we cannot invoke compareTo among them. To
415	>	* handle this, the tree is ordered primarily by hash value, then
416	>	* by Comparable.compareTo order if applicable.  On lookup at a
417	>	* node, if elements are not comparable or compare as 0 then both
418	>	* left and right children may need to be searched in the case of
419	>	* tied hash values. (This corresponds to the full list search
420	>	* that would be necessary if all elements were non-Comparable and
421	>	* had tied hashes.)  The red-black balancing code is updated from
422	>	* pre-jdk-collections
423	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
424	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
425	>	* Algorithms" (CLR).
426	>	*
427	>	* TreeBins also require an additional locking mechanism.  While
428	>	* list traversal is always possible by readers even during
429	>	* updates, tree traversal is not, mainly because of tree-rotations
430	>	* that may change the root node and/or its linkages.  TreeBins
431	>	* include a simple read-write lock mechanism parasitic on the
432	>	* main bin-synchronization strategy: Structural adjustments
433	>	* associated with an insertion or removal are already bin-locked
434	>	* (and so cannot conflict with other writers) but must wait for
435	>	* ongoing readers to finish. Since there can be only one such
436	>	* waiter, we use a simple scheme using a single "waiter" field to
437	>	* block writers.  However, readers need never block.  If the root
438	>	* lock is held, they proceed along the slow traversal path (via
439	>	* next-pointers) until the lock becomes available or the list is
440	>	* exhausted, whichever comes first. These cases are not fast, but
441	>	* maximize aggregate expected throughput.
442	>	*
443	>	* Maintaining API and serialization compatibility with previous
444	>	* versions of this class introduces several oddities. Mainly: We
445	>	* leave untouched but unused constructor arguments refering to
446	>	* concurrencyLevel. We accept a loadFactor constructor argument,
447	>	* but apply it only to initial table capacity (which is the only
448	>	* time that we can guarantee to honor it.) We also declare an
449	>	* unused "Segment" class that is instantiated in minimal form
450	>	* only when serializing.
451	>	*
452	>	* This file is organized to make things a little easier to follow
453	>	* while reading than they might otherwise: First the main static
454	>	* declarations and utilities, then fields, then main public
455	>	* methods (with a few factorings of multiple public methods into
456	>	* internal ones), then sizing methods, trees, traversers, and
457	>	* bulk operations.
458		*/
459
460		/* ---------------- Constants -------------- */
461
462		/**
463	<	* The default initial capacity for this table,
464	<	* used when not otherwise specified in a constructor.
463	>	* The largest possible table capacity.  This value must be
464	>	* exactly 1<<30 to stay within Java array allocation and indexing
465	>	* bounds for power of two table sizes, and is further required
466	>	* because the top two bits of 32bit hash fields are used for
467	>	* control purposes.
468		*/
469	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
469	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
470
471		/**
472	<	* The default load factor for this table, used when not
473	<	* otherwise specified in a constructor.
472	>	* The default initial table capacity.  Must be a power of 2
473	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
474		*/
475	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
475	>	private static final int DEFAULT_CAPACITY = 16;
476
477		/**
478	<	* The default concurrency level for this table, used when not
479	<	* otherwise specified in a constructor.
478	>	* The largest possible (non-power of two) array size.
479	>	* Needed by toArray and related methods.
480		*/
481	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
481	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
482
483		/**
484	<	* The maximum capacity, used if a higher value is implicitly
485	<	* specified by either of the constructors with arguments.  MUST
105	<	* be a power of two <= 1<<30 to ensure that entries are indexable
106	<	* using ints.
484	>	* The default concurrency level for this table. Unused but
485	>	* defined for compatibility with previous versions of this class.
486		*/
487	<	static final int MAXIMUM_CAPACITY = 1 << 30;
487	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
488
489		/**
490	<	* The maximum number of segments to allow; used to bound
491	<	* constructor arguments.
490	>	* The load factor for this table. Overrides of this value in
491	>	* constructors affect only the initial table capacity.  The
492	>	* actual floating point value isn't normally used -- it is
493	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
494	>	* the associated resizing threshold.
495		*/
496	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
496	>	private static final float LOAD_FACTOR = 0.75f;
497
498		/**
499	<	* Number of unsynchronized retries in size and containsValue
500	<	* methods before resorting to locking. This is used to avoid
501	<	* unbounded retries if tables undergo continuous modification
502	<	* which would make it impossible to obtain an accurate result.
499	>	* The bin count threshold for using a tree rather than list for a
500	>	* bin.  Bins are converted to trees when adding an element to a
501	>	* bin with at least this many nodes. The value must be greater
502	>	* than 2, and should be at least 8 to mesh with assumptions in
503	>	* tree removal about conversion back to plain bins upon
504	>	* shrinkage.
505		*/
506	<	static final int RETRIES_BEFORE_LOCK = 2;
123	<
124	<	/* ---------------- Fields -------------- */
506	>	static final int TREEIFY_THRESHOLD = 8;
507
508		/**
509	<	* Mask value for indexing into segments. The upper bits of a
510	<	* key's hash code are used to choose the segment.
509	>	* The bin count threshold for untreeifying a (split) bin during a
510	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
511	>	* most 6 to mesh with shrinkage detection under removal.
512		*/
513	<	final int segmentMask;
513	>	static final int UNTREEIFY_THRESHOLD = 6;
514
515		/**
516	<	* Shift value for indexing within segments.
516	>	* The smallest table capacity for which bins may be treeified.
517	>	* (Otherwise the table is resized if too many nodes in a bin.)
518	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
519	>	* conflicts between resizing and treeification thresholds.
520		*/
521	<	final int segmentShift;
521	>	static final int MIN_TREEIFY_CAPACITY = 64;
522
523		/**
524	<	* The segments, each of which is a specialized hash table
524	>	* Minimum number of rebinnings per transfer step. Ranges are
525	>	* subdivided to allow multiple resizer threads.  This value
526	>	* serves as a lower bound to avoid resizers encountering
527	>	* excessive memory contention.  The value should be at least
528	>	* DEFAULT_CAPACITY.
529		*/
530	<	final Segment<K,V>[] segments;
530	>	private static final int MIN_TRANSFER_STRIDE = 16;
531
532	<	transient Set<K> keySet;
533	<	transient Set<Map.Entry<K,V>> entrySet;
144	<	transient Collection<V> values;
145	<
146	<	/* ---------------- Small Utilities -------------- */
147	<
148	<	/**
149	<	* Applies a supplemental hash function to a given hashCode, which
150	<	* defends against poor quality hash functions.  This is critical
151	<	* because ConcurrentHashMap uses power-of-two length hash tables,
152	<	* that otherwise encounter collisions for hashCodes that do not
153	<	* differ in lower bits.
154	<	*/
155	<	private static int hash(int h) {
156	<	// Spread bits to regularize both segment and index locations,
157	<	// using variant of Jenkins's shift-based hash.
158	<	h += ~(h << 13);
159	<	h ^= h >>> 7;
160	<	h += h << 3;
161	<	h ^= h >>> 17;
162	<	h += h << 5;
163	<	return h;
164	<	}
165	<
166	<	/**
167	<	* Returns the segment that should be used for key with given hash
168	<	* @param hash the hash code for the key
169	<	* @return the segment
532	>	/*
533	>	* Encodings for Node hash fields. See above for explanation.
534		*/
535	<	final Segment<K,V> segmentFor(int hash) {
536	<	return segments[(hash >>> segmentShift) & segmentMask];
537	<	}
535	>	static final int MOVED     = -1; // hash for forwarding nodes
536	>	static final int TREEBIN   = -2; // hash for roots of trees
537	>	static final int RESERVED  = -3; // hash for transient reservations
538	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
539	>
540	>	/** Number of CPUS, to place bounds on some sizings */
541	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
542	>
543	>	/** For serialization compatibility. */
544	>	private static final ObjectStreamField[] serialPersistentFields = {
545	>	new ObjectStreamField("segments", Segment[].class),
546	>	new ObjectStreamField("segmentMask", Integer.TYPE),
547	>	new ObjectStreamField("segmentShift", Integer.TYPE)
548	>	};
549
550	<	/* ---------------- Inner Classes -------------- */
550	>	/* ---------------- Nodes -------------- */
551
552		/**
553	<	* ConcurrentHashMap list entry. Note that this is never exported
554	<	* out as a user-visible Map.Entry.
555	<	*
556	<	* Because the value field is volatile, not final, it is legal wrt
557	<	* the Java Memory Model for an unsynchronized reader to see null
558	<	* instead of initial value when read via a data race.  Although a
184	<	* reordering leading to this is not likely to ever actually
185	<	* occur, the Segment.readValueUnderLock method is used as a
186	<	* backup in case a null (pre-initialized) value is ever seen in
187	<	* an unsynchronized access method.
553	>	* Key-value entry.  This class is never exported out as a
554	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
555	>	* MapEntry below), but can be used for read-only traversals used
556	>	* in bulk tasks.  Subclasses of Node with a negative hash field
557	>	* are special, and contain null keys and values (but are never
558	>	* exported).  Otherwise, keys and vals are never null.
559		*/
560	<	static final class HashEntry<K,V> {
190	<	final K key;
560	>	static class Node<K,V> implements Map.Entry<K,V> {
561		final int hash;
562	<	volatile V value;
563	<	final HashEntry<K,V> next;
562	>	final K key;
563	>	volatile V val;
564	>	volatile Node<K,V> next;
565
566	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
196	<	this.key = key;
566	>	Node(int hash, K key, V val, Node<K,V> next) {
567		this.hash = hash;
568	+	this.key = key;
569	+	this.val = val;
570		this.next = next;
199	–	this.value = value;
571		}
572
573	<	@SuppressWarnings("unchecked")
574	<	static final <K,V> HashEntry<K,V>[] newArray(int i) {
575	<	return new HashEntry[i];
576	<	}
577	<	}
578	<
208	<	/**
209	<	* Segments are specialized versions of hash tables.  This
210	<	* subclasses from ReentrantLock opportunistically, just to
211	<	* simplify some locking and avoid separate construction.
212	<	*/
213	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
214	<	/*
215	<	* Segments maintain a table of entry lists that are ALWAYS
216	<	* kept in a consistent state, so can be read without locking.
217	<	* Next fields of nodes are immutable (final).  All list
218	<	* additions are performed at the front of each bin. This
219	<	* makes it easy to check changes, and also fast to traverse.
220	<	* When nodes would otherwise be changed, new nodes are
221	<	* created to replace them. This works well for hash tables
222	<	* since the bin lists tend to be short. (The average length
223	<	* is less than two for the default load factor threshold.)
224	<	*
225	<	* Read operations can thus proceed without locking, but rely
226	<	* on selected uses of volatiles to ensure that completed
227	<	* write operations performed by other threads are
228	<	* noticed. For most purposes, the "count" field, tracking the
229	<	* number of elements, serves as that volatile variable
230	<	* ensuring visibility.  This is convenient because this field
231	<	* needs to be read in many read operations anyway:
232	<	*
233	<	*   - All (unsynchronized) read operations must first read the
234	<	*     "count" field, and should not look at table entries if
235	<	*     it is 0.
236	<	*
237	<	*   - All (synchronized) write operations should write to
238	<	*     the "count" field after structurally changing any bin.
239	<	*     The operations must not take any action that could even
240	<	*     momentarily cause a concurrent read operation to see
241	<	*     inconsistent data. This is made easier by the nature of
242	<	*     the read operations in Map. For example, no operation
243	<	*     can reveal that the table has grown but the threshold
244	<	*     has not yet been updated, so there are no atomicity
245	<	*     requirements for this with respect to reads.
246	<	*
247	<	* As a guide, all critical volatile reads and writes to the
248	<	* count field are marked in code comments.
249	<	*/
250	<
251	<	private static final long serialVersionUID = 2249069246763182397L;
252	<
253	<	/**
254	<	* The number of elements in this segment's region.
255	<	*/
256	<	transient volatile int count;
257	<
258	<	/**
259	<	* Number of updates that alter the size of the table. This is
260	<	* used during bulk-read methods to make sure they see a
261	<	* consistent snapshot: If modCounts change during a traversal
262	<	* of segments computing size or checking containsValue, then
263	<	* we might have an inconsistent view of state so (usually)
264	<	* must retry.
265	<	*/
266	<	transient int modCount;
267	<
268	<	/**
269	<	* The table is rehashed when its size exceeds this threshold.
270	<	* (The value of this field is always <tt>(int)(capacity *
271	<	* loadFactor)</tt>.)
272	<	*/
273	<	transient int threshold;
274	<
275	<	/**
276	<	* The per-segment table.
277	<	*/
278	<	transient volatile HashEntry<K,V>[] table;
279	<
280	<	/**
281	<	* The load factor for the hash table.  Even though this value
282	<	* is same for all segments, it is replicated to avoid needing
283	<	* links to outer object.
284	<	* @serial
285	<	*/
286	<	final float loadFactor;
287	<
288	<	Segment(int initialCapacity, float lf) {
289	<	loadFactor = lf;
290	<	setTable(HashEntry.<K,V>newArray(initialCapacity));
291	<	}
292	<
293	<	@SuppressWarnings("unchecked")
294	<	static final <K,V> Segment<K,V>[] newArray(int i) {
295	<	return new Segment[i];
296	<	}
297	<
298	<	/**
299	<	* Sets table to new HashEntry array.
300	<	* Call only while holding lock or in constructor.
301	<	*/
302	<	void setTable(HashEntry<K,V>[] newTable) {
303	<	threshold = (int)(newTable.length * loadFactor);
304	<	table = newTable;
573	>	public final K getKey()       { return key; }
574	>	public final V getValue()     { return val; }
575	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
576	>	public final String toString(){ return key + "=" + val; }
577	>	public final V setValue(V value) {
578	>	throw new UnsupportedOperationException();
579		}
580
581	<	/**
582	<	* Returns properly casted first entry of bin for given hash.
583	<	*/
584	<	HashEntry<K,V> getFirst(int hash) {
585	<	HashEntry<K,V>[] tab = table;
586	<	return tab[hash & (tab.length - 1)];
581	>	public final boolean equals(Object o) {
582	>	Object k, v, u; Map.Entry<?,?> e;
583	>	return ((o instanceof Map.Entry) &&
584	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
585	>	(v = e.getValue()) != null &&
586	>	(k == key || k.equals(key)) &&
587	>	(v == (u = val) || v.equals(u)));
588		}
589
590		/**
591	<	* Reads value field of an entry under lock. Called if value
317	<	* field ever appears to be null. This is possible only if a
318	<	* compiler happens to reorder a HashEntry initialization with
319	<	* its table assignment, which is legal under memory model
320	<	* but is not known to ever occur.
591	>	* Virtualized support for map.get(); overridden in subclasses.
592		*/
593	<	V readValueUnderLock(HashEntry<K,V> e) {
594	<	lock();
595	<	try {
596	<	return e.value;
597	<	} finally {
598	<	unlock();
593	>	Node<K,V> find(int h, Object k) {
594	>	Node<K,V> e = this;
595	>	if (k != null) {
596	>	do {
597	>	K ek;
598	>	if (e.hash == h &&
599	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
600	>	return e;
601	>	} while ((e = e.next) != null);
602		}
603	+	return null;
604		}
605	+	}
606
607	<	/* Specialized implementations of map methods */
607	>	/* ---------------- Static utilities -------------- */
608
609	<	V get(Object key, int hash) {
610	<	if (count != 0) { // read-volatile
611	<	HashEntry<K,V> e = getFirst(hash);
612	<	while (e != null) {
613	<	if (e.hash == hash && key.equals(e.key)) {
614	<	V v = e.value;
615	<	if (v != null)
616	<	return v;
617	<	return readValueUnderLock(e); // recheck
618	<	}
619	<	e = e.next;
620	<	}
621	<	}
622	<	return null;
623	<	}
609	>	/**
610	>	* Spreads (XORs) higher bits of hash to lower and also forces top
611	>	* bit to 0. Because the table uses power-of-two masking, sets of
612	>	* hashes that vary only in bits above the current mask will
613	>	* always collide. (Among known examples are sets of Float keys
614	>	* holding consecutive whole numbers in small tables.)  So we
615	>	* apply a transform that spreads the impact of higher bits
616	>	* downward. There is a tradeoff between speed, utility, and
617	>	* quality of bit-spreading. Because many common sets of hashes
618	>	* are already reasonably distributed (so don't benefit from
619	>	* spreading), and because we use trees to handle large sets of
620	>	* collisions in bins, we just XOR some shifted bits in the
621	>	* cheapest possible way to reduce systematic lossage, as well as
622	>	* to incorporate impact of the highest bits that would otherwise
623	>	* never be used in index calculations because of table bounds.
624	>	*/
625	>	static final int spread(int h) {
626	>	return (h ^ (h >>> 16)) & HASH_BITS;
627	>	}
628
629	<	boolean containsKey(Object key, int hash) {
630	<	if (count != 0) { // read-volatile
631	<	HashEntry<K,V> e = getFirst(hash);
632	<	while (e != null) {
633	<	if (e.hash == hash && key.equals(e.key))
634	<	return true;
635	<	e = e.next;
636	<	}
637	<	}
638	<	return false;
639	<	}
629	>	/**
630	>	* Returns a power of two table size for the given desired capacity.
631	>	* See Hackers Delight, sec 3.2
632	>	*/
633	>	private static final int tableSizeFor(int c) {
634	>	int n = c - 1;
635	>	n |= n >>> 1;
636	>	n |= n >>> 2;
637	>	n |= n >>> 4;
638	>	n |= n >>> 8;
639	>	n |= n >>> 16;
640	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
641	>	}
642
643	<	boolean containsValue(Object value) {
644	<	if (count != 0) { // read-volatile
645	<	HashEntry<K,V>[] tab = table;
646	<	int len = tab.length;
647	<	for (int i = 0 ; i < len; i++) {
648	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
649	<	V v = e.value;
650	<	if (v == null) // recheck
651	<	v = readValueUnderLock(e);
652	<	if (value.equals(v))
653	<	return true;
654	<	}
643	>	/**
644	>	* Returns x's Class if it is of the form "class C implements
645	>	* Comparable<C>", else null.
646	>	*/
647	>	static Class<?> comparableClassFor(Object x) {
648	>	if (x instanceof Comparable) {
649	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
650	>	if ((c = x.getClass()) == String.class) // bypass checks
651	>	return c;
652	>	if ((ts = c.getGenericInterfaces()) != null) {
653	>	for (int i = 0; i < ts.length; ++i) {
654	>	if (((t = ts[i]) instanceof ParameterizedType) &&
655	>	((p = (ParameterizedType)t).getRawType() ==
656	>	Comparable.class) &&
657	>	(as = p.getActualTypeArguments()) != null &&
658	>	as.length == 1 && as[0] == c) // type arg is c
659	>	return c;
660		}
661		}
375	–	return false;
662		}
663	+	return null;
664	+	}
665
666	<	boolean replace(K key, int hash, V oldValue, V newValue) {
667	<	lock();
668	<	try {
669	<	HashEntry<K,V> e = getFirst(hash);
670	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
671	<	e = e.next;
672	<
673	<	boolean replaced = false;
674	<	if (e != null && oldValue.equals(e.value)) {
387	<	replaced = true;
388	<	e.value = newValue;
389	<	}
390	<	return replaced;
391	<	} finally {
392	<	unlock();
393	<	}
394	<	}
666	>	/**
667	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
668	>	* class), else 0.
669	>	*/
670	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
671	>	static int compareComparables(Class<?> kc, Object k, Object x) {
672	>	return (x == null || x.getClass() != kc ? 0 :
673	>	((Comparable)k).compareTo(x));
674	>	}
675
676	<	V replace(K key, int hash, V newValue) {
397	<	lock();
398	<	try {
399	<	HashEntry<K,V> e = getFirst(hash);
400	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
401	<	e = e.next;
402	<
403	<	V oldValue = null;
404	<	if (e != null) {
405	<	oldValue = e.value;
406	<	e.value = newValue;
407	<	}
408	<	return oldValue;
409	<	} finally {
410	<	unlock();
411	<	}
412	<	}
676	>	/* ---------------- Table element access -------------- */
677
678	+	/*
679	+	* Volatile access methods are used for table elements as well as
680	+	* elements of in-progress next table while resizing.  All uses of
681	+	* the tab arguments must be null checked by callers.  All callers
682	+	* also paranoically precheck that tab's length is not zero (or an
683	+	* equivalent check), thus ensuring that any index argument taking
684	+	* the form of a hash value anded with (length - 1) is a valid
685	+	* index.  Note that, to be correct wrt arbitrary concurrency
686	+	* errors by users, these checks must operate on local variables,
687	+	* which accounts for some odd-looking inline assignments below.
688	+	* Note that calls to setTabAt always occur within locked regions,
689	+	* and so in principle require only release ordering, not need
690	+	* full volatile semantics, but are currently coded as volatile
691	+	* writes to be conservative.
692	+	*/
693	+
694	+	@SuppressWarnings("unchecked")
695	+	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
696	+	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
697	+	}
698
699	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
700	<	lock();
701	<	try {
702	<	int c = count;
419	<	if (c++ > threshold) // ensure capacity
420	<	rehash();
421	<	HashEntry<K,V>[] tab = table;
422	<	int index = hash & (tab.length - 1);
423	<	HashEntry<K,V> first = tab[index];
424	<	HashEntry<K,V> e = first;
425	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
426	<	e = e.next;
427	<
428	<	V oldValue;
429	<	if (e != null) {
430	<	oldValue = e.value;
431	<	if (!onlyIfAbsent)
432	<	e.value = value;
433	<	}
434	<	else {
435	<	oldValue = null;
436	<	++modCount;
437	<	tab[index] = new HashEntry<K,V>(key, hash, first, value);
438	<	count = c; // write-volatile
439	<	}
440	<	return oldValue;
441	<	} finally {
442	<	unlock();
443	<	}
444	<	}
699	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
700	>	Node<K,V> c, Node<K,V> v) {
701	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
702	>	}
703
704	<	void rehash() {
705	<	HashEntry<K,V>[] oldTable = table;
706	<	int oldCapacity = oldTable.length;
449	<	if (oldCapacity >= MAXIMUM_CAPACITY)
450	<	return;
704	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
705	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
706	>	}
707
708	<	/*
453	<	* Reclassify nodes in each list to new Map.  Because we are
454	<	* using power-of-two expansion, the elements from each bin
455	<	* must either stay at same index, or move with a power of two
456	<	* offset. We eliminate unnecessary node creation by catching
457	<	* cases where old nodes can be reused because their next
458	<	* fields won't change. Statistically, at the default
459	<	* threshold, only about one-sixth of them need cloning when
460	<	* a table doubles. The nodes they replace will be garbage
461	<	* collectable as soon as they are no longer referenced by any
462	<	* reader thread that may be in the midst of traversing table
463	<	* right now.
464	<	*/
465	<
466	<	HashEntry<K,V>[] newTable = HashEntry.newArray(oldCapacity<<1);
467	<	threshold = (int)(newTable.length * loadFactor);
468	<	int sizeMask = newTable.length - 1;
469	<	for (int i = 0; i < oldCapacity ; i++) {
470	<	// We need to guarantee that any existing reads of old Map can
471	<	//  proceed. So we cannot yet null out each bin.
472	<	HashEntry<K,V> e = oldTable[i];
473	<
474	<	if (e != null) {
475	<	HashEntry<K,V> next = e.next;
476	<	int idx = e.hash & sizeMask;
477	<
478	<	//  Single node on list
479	<	if (next == null)
480	<	newTable[idx] = e;
708	>	/* ---------------- Fields -------------- */
709
710	<	else {
711	<	// Reuse trailing consecutive sequence at same slot
712	<	HashEntry<K,V> lastRun = e;
713	<	int lastIdx = idx;
714	<	for (HashEntry<K,V> last = next;
487	<	last != null;
488	<	last = last.next) {
489	<	int k = last.hash & sizeMask;
490	<	if (k != lastIdx) {
491	<	lastIdx = k;
492	<	lastRun = last;
493	<	}
494	<	}
495	<	newTable[lastIdx] = lastRun;
710	>	/**
711	>	* The array of bins. Lazily initialized upon first insertion.
712	>	* Size is always a power of two. Accessed directly by iterators.
713	>	*/
714	>	transient volatile Node<K,V>[] table;
715
716	<	// Clone all remaining nodes
717	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
718	<	int k = p.hash & sizeMask;
719	<	HashEntry<K,V> n = newTable[k];
501	<	newTable[k] = new HashEntry<K,V>(p.key, p.hash,
502	<	n, p.value);
503	<	}
504	<	}
505	<	}
506	<	}
507	<	table = newTable;
508	<	}
716	>	/**
717	>	* The next table to use; non-null only while resizing.
718	>	*/
719	>	private transient volatile Node<K,V>[] nextTable;
720
721	<	/**
722	<	* Remove; match on key only if value null, else match both.
723	<	*/
724	<	V remove(Object key, int hash, Object value) {
725	<	lock();
726	<	try {
516	<	int c = count - 1;
517	<	HashEntry<K,V>[] tab = table;
518	<	int index = hash & (tab.length - 1);
519	<	HashEntry<K,V> first = tab[index];
520	<	HashEntry<K,V> e = first;
521	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
522	<	e = e.next;
523	<
524	<	V oldValue = null;
525	<	if (e != null) {
526	<	V v = e.value;
527	<	if (value == null || value.equals(v)) {
528	<	oldValue = v;
529	<	// All entries following removed node can stay
530	<	// in list, but all preceding ones need to be
531	<	// cloned.
532	<	++modCount;
533	<	HashEntry<K,V> newFirst = e.next;
534	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
535	<	newFirst = new HashEntry<K,V>(p.key, p.hash,
536	<	newFirst, p.value);
537	<	tab[index] = newFirst;
538	<	count = c; // write-volatile
539	<	}
540	<	}
541	<	return oldValue;
542	<	} finally {
543	<	unlock();
544	<	}
545	<	}
721	>	/**
722	>	* Base counter value, used mainly when there is no contention,
723	>	* but also as a fallback during table initialization
724	>	* races. Updated via CAS.
725	>	*/
726	>	private transient volatile long baseCount;
727
728	<	void clear() {
729	<	if (count != 0) {
730	<	lock();
731	<	try {
732	<	HashEntry<K,V>[] tab = table;
733	<	for (int i = 0; i < tab.length ; i++)
734	<	tab[i] = null;
735	<	++modCount;
736	<	count = 0; // write-volatile
556	<	} finally {
557	<	unlock();
558	<	}
559	<	}
560	<	}
561	<	}
728	>	/**
729	>	* Table initialization and resizing control.  When negative, the
730	>	* table is being initialized or resized: -1 for initialization,
731	>	* else -(1 + the number of active resizing threads).  Otherwise,
732	>	* when table is null, holds the initial table size to use upon
733	>	* creation, or 0 for default. After initialization, holds the
734	>	* next element count value upon which to resize the table.
735	>	*/
736	>	private transient volatile int sizeCtl;
737
738	+	/**
739	+	* The next table index (plus one) to split while resizing.
740	+	*/
741	+	private transient volatile int transferIndex;
742
743	+	/**
744	+	* The least available table index to split while resizing.
745	+	*/
746	+	private transient volatile int transferOrigin;
747
748	<	/* ---------------- Public operations -------------- */
748	>	/**
749	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
750	>	*/
751	>	private transient volatile int cellsBusy;
752
753		/**
754	<	* Creates a new, empty map with the specified initial
569	<	* capacity, load factor and concurrency level.
570	<	*
571	<	* @param initialCapacity the initial capacity. The implementation
572	<	* performs internal sizing to accommodate this many elements.
573	<	* @param loadFactor  the load factor threshold, used to control resizing.
574	<	* Resizing may be performed when the average number of elements per
575	<	* bin exceeds this threshold.
576	<	* @param concurrencyLevel the estimated number of concurrently
577	<	* updating threads. The implementation performs internal sizing
578	<	* to try to accommodate this many threads.
579	<	* @throws IllegalArgumentException if the initial capacity is
580	<	* negative or the load factor or concurrencyLevel are
581	<	* nonpositive.
754	>	* Table of counter cells. When non-null, size is a power of 2.
755		*/
756	<	public ConcurrentHashMap(int initialCapacity,
584	<	float loadFactor, int concurrencyLevel) {
585	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
586	<	throw new IllegalArgumentException();
756	>	private transient volatile CounterCell[] counterCells;
757
758	<	if (concurrencyLevel > MAX_SEGMENTS)
759	<	concurrencyLevel = MAX_SEGMENTS;
758	>	// views
759	>	private transient KeySetView<K,V> keySet;
760	>	private transient ValuesView<K,V> values;
761	>	private transient EntrySetView<K,V> entrySet;
762
591	–	// Find power-of-two sizes best matching arguments
592	–	int sshift = 0;
593	–	int ssize = 1;
594	–	while (ssize < concurrencyLevel) {
595	–	++sshift;
596	–	ssize <<= 1;
597	–	}
598	–	segmentShift = 32 - sshift;
599	–	segmentMask = ssize - 1;
600	–	this.segments = Segment.newArray(ssize);
601	–
602	–	if (initialCapacity > MAXIMUM_CAPACITY)
603	–	initialCapacity = MAXIMUM_CAPACITY;
604	–	int c = initialCapacity / ssize;
605	–	if (c * ssize < initialCapacity)
606	–	++c;
607	–	int cap = 1;
608	–	while (cap < c)
609	–	cap <<= 1;
763
764	<	for (int i = 0; i < this.segments.length; ++i)
612	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
613	<	}
764	>	/* ---------------- Public operations -------------- */
765
766		/**
767	<	* Creates a new, empty map with the specified initial capacity
617	<	* and load factor and with the default concurrencyLevel (16).
618	<	*
619	<	* @param initialCapacity The implementation performs internal
620	<	* sizing to accommodate this many elements.
621	<	* @param loadFactor  the load factor threshold, used to control resizing.
622	<	* Resizing may be performed when the average number of elements per
623	<	* bin exceeds this threshold.
624	<	* @throws IllegalArgumentException if the initial capacity of
625	<	* elements is negative or the load factor is nonpositive
626	<	*
627	<	* @since 1.6
767	>	* Creates a new, empty map with the default initial table size (16).
768		*/
769	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
630	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
769	>	public ConcurrentHashMap() {
770		}
771
772		/**
773	<	* Creates a new, empty map with the specified initial capacity,
774	<	* and with default load factor (0.75) and concurrencyLevel (16).
773	>	* Creates a new, empty map with an initial table size
774	>	* accommodating the specified number of elements without the need
775	>	* to dynamically resize.
776		*
777	<	* @param initialCapacity the initial capacity. The implementation
778	<	* performs internal sizing to accommodate this many elements.
777	>	* @param initialCapacity The implementation performs internal
778	>	* sizing to accommodate this many elements.
779		* @throws IllegalArgumentException if the initial capacity of
780	<	* elements is negative.
780	>	* elements is negative
781		*/
782		public ConcurrentHashMap(int initialCapacity) {
783	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
784	<	}
785	<
786	<	/**
787	<	* Creates a new, empty map with a default initial capacity (16),
788	<	* load factor (0.75) and concurrencyLevel (16).
649	<	*/
650	<	public ConcurrentHashMap() {
651	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
783	>	if (initialCapacity < 0)
784	>	throw new IllegalArgumentException();
785	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
786	>	MAXIMUM_CAPACITY :
787	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
788	>	this.sizeCtl = cap;
789		}
790
791		/**
792		* Creates a new map with the same mappings as the given map.
656	–	* The map is created with a capacity of 1.5 times the number
657	–	* of mappings in the given map or 16 (whichever is greater),
658	–	* and a default load factor (0.75) and concurrencyLevel (16).
793		*
794		* @param m the map
795		*/
796		public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
797	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
664	<	DEFAULT_INITIAL_CAPACITY),
665	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
797	>	this.sizeCtl = DEFAULT_CAPACITY;
798		putAll(m);
799		}
800
801		/**
802	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
802	>	* Creates a new, empty map with an initial table size based on
803	>	* the given number of elements ({@code initialCapacity}) and
804	>	* initial table density ({@code loadFactor}).
805		*
806	<	* @return <tt>true</tt> if this map contains no key-value mappings
806	>	* @param initialCapacity the initial capacity. The implementation
807	>	* performs internal sizing to accommodate this many elements,
808	>	* given the specified load factor.
809	>	* @param loadFactor the load factor (table density) for
810	>	* establishing the initial table size
811	>	* @throws IllegalArgumentException if the initial capacity of
812	>	* elements is negative or the load factor is nonpositive
813	>	*
814	>	* @since 1.6
815		*/
816	<	public boolean isEmpty() {
817	<	final Segment<K,V>[] segments = this.segments;
676	<	/*
677	<	* We keep track of per-segment modCounts to avoid ABA
678	<	* problems in which an element in one segment was added and
679	<	* in another removed during traversal, in which case the
680	<	* table was never actually empty at any point. Note the
681	<	* similar use of modCounts in the size() and containsValue()
682	<	* methods, which are the only other methods also susceptible
683	<	* to ABA problems.
684	<	*/
685	<	int[] mc = new int[segments.length];
686	<	int mcsum = 0;
687	<	for (int i = 0; i < segments.length; ++i) {
688	<	if (segments[i].count != 0)
689	<	return false;
690	<	else
691	<	mcsum += mc[i] = segments[i].modCount;
692	<	}
693	<	// If mcsum happens to be zero, then we know we got a snapshot
694	<	// before any modifications at all were made.  This is
695	<	// probably common enough to bother tracking.
696	<	if (mcsum != 0) {
697	<	for (int i = 0; i < segments.length; ++i) {
698	<	if (segments[i].count != 0 ||
699	<	mc[i] != segments[i].modCount)
700	<	return false;
701	<	}
702	<	}
703	<	return true;
816	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
817	>	this(initialCapacity, loadFactor, 1);
818		}
819
820		/**
821	<	* Returns the number of key-value mappings in this map.  If the
822	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
823	<	* <tt>Integer.MAX_VALUE</tt>.
821	>	* Creates a new, empty map with an initial table size based on
822	>	* the given number of elements ({@code initialCapacity}), table
823	>	* density ({@code loadFactor}), and number of concurrently
824	>	* updating threads ({@code concurrencyLevel}).
825		*
826	<	* @return the number of key-value mappings in this map
826	>	* @param initialCapacity the initial capacity. The implementation
827	>	* performs internal sizing to accommodate this many elements,
828	>	* given the specified load factor.
829	>	* @param loadFactor the load factor (table density) for
830	>	* establishing the initial table size
831	>	* @param concurrencyLevel the estimated number of concurrently
832	>	* updating threads. The implementation may use this value as
833	>	* a sizing hint.
834	>	* @throws IllegalArgumentException if the initial capacity is
835	>	* negative or the load factor or concurrencyLevel are
836	>	* nonpositive
837	>	*/
838	>	public ConcurrentHashMap(int initialCapacity,
839	>	float loadFactor, int concurrencyLevel) {
840	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
841	>	throw new IllegalArgumentException();
842	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
843	>	initialCapacity = concurrencyLevel;   // as estimated threads
844	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
845	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
846	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
847	>	this.sizeCtl = cap;
848	>	}
849	>
850	>	// Original (since JDK1.2) Map methods
851	>
852	>	/**
853	>	* {@inheritDoc}
854		*/
855		public int size() {
856	<	final Segment<K,V>[] segments = this.segments;
857	<	long sum = 0;
858	<	long check = 0;
859	<	int[] mc = new int[segments.length];
860	<	// Try a few times to get accurate count. On failure due to
861	<	// continuous async changes in table, resort to locking.
862	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
863	<	check = 0;
864	<	sum = 0;
865	<	int mcsum = 0;
866	<	for (int i = 0; i < segments.length; ++i) {
725	<	sum += segments[i].count;
726	<	mcsum += mc[i] = segments[i].modCount;
727	<	}
728	<	if (mcsum != 0) {
729	<	for (int i = 0; i < segments.length; ++i) {
730	<	check += segments[i].count;
731	<	if (mc[i] != segments[i].modCount) {
732	<	check = -1; // force retry
733	<	break;
734	<	}
735	<	}
736	<	}
737	<	if (check == sum)
738	<	break;
739	<	}
740	<	if (check != sum) { // Resort to locking all segments
741	<	sum = 0;
742	<	for (int i = 0; i < segments.length; ++i)
743	<	segments[i].lock();
744	<	for (int i = 0; i < segments.length; ++i)
745	<	sum += segments[i].count;
746	<	for (int i = 0; i < segments.length; ++i)
747	<	segments[i].unlock();
748	<	}
749	<	if (sum > Integer.MAX_VALUE)
750	<	return Integer.MAX_VALUE;
751	<	else
752	<	return (int)sum;
856	>	long n = sumCount();
857	>	return ((n < 0L) ? 0 :
858	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
859	>	(int)n);
860	>	}
861	>
862	>	/**
863	>	* {@inheritDoc}
864	>	*/
865	>	public boolean isEmpty() {
866	>	return sumCount() <= 0L; // ignore transient negative values
867		}
868
869		/**
#	Line 764 | Line 878 | public class ConcurrentHashMap<K, V> ext
878		* @throws NullPointerException if the specified key is null
879		*/
880		public V get(Object key) {
881	<	int hash = hash(key.hashCode());
882	<	return segmentFor(hash).get(key, hash);
881	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
882	>	int h = spread(key.hashCode());
883	>	if ((tab = table) != null && (n = tab.length) > 0 &&
884	>	(e = tabAt(tab, (n - 1) & h)) != null) {
885	>	if ((eh = e.hash) == h) {
886	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
887	>	return e.val;
888	>	}
889	>	else if (eh < 0)
890	>	return (p = e.find(h, key)) != null ? p.val : null;
891	>	while ((e = e.next) != null) {
892	>	if (e.hash == h &&
893	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
894	>	return e.val;
895	>	}
896	>	}
897	>	return null;
898		}
899
900		/**
901		* Tests if the specified object is a key in this table.
902		*
903	<	* @param  key   possible key
904	<	* @return <tt>true</tt> if and only if the specified object
903	>	* @param  key possible key
904	>	* @return {@code true} if and only if the specified object
905		*         is a key in this table, as determined by the
906	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
906	>	*         {@code equals} method; {@code false} otherwise
907		* @throws NullPointerException if the specified key is null
908		*/
909		public boolean containsKey(Object key) {
910	<	int hash = hash(key.hashCode());
782	<	return segmentFor(hash).containsKey(key, hash);
910	>	return get(key) != null;
911		}
912
913		/**
914	<	* Returns <tt>true</tt> if this map maps one or more keys to the
915	<	* specified value. Note: This method requires a full internal
916	<	* traversal of the hash table, and so is much slower than
789	<	* method <tt>containsKey</tt>.
914	>	* Returns {@code true} if this map maps one or more keys to the
915	>	* specified value. Note: This method may require a full traversal
916	>	* of the map, and is much slower than method {@code containsKey}.
917		*
918		* @param value value whose presence in this map is to be tested
919	<	* @return <tt>true</tt> if this map maps one or more keys to the
919	>	* @return {@code true} if this map maps one or more keys to the
920		*         specified value
921		* @throws NullPointerException if the specified value is null
922		*/
923		public boolean containsValue(Object value) {
924		if (value == null)
925		throw new NullPointerException();
926	<
927	<	// See explanation of modCount use above
928	<
929	<	final Segment<K,V>[] segments = this.segments;
930	<	int[] mc = new int[segments.length];
931	<
805	<	// Try a few times without locking
806	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
807	<	int sum = 0;
808	<	int mcsum = 0;
809	<	for (int i = 0; i < segments.length; ++i) {
810	<	int c = segments[i].count;
811	<	mcsum += mc[i] = segments[i].modCount;
812	<	if (segments[i].containsValue(value))
926	>	Node<K,V>[] t;
927	>	if ((t = table) != null) {
928	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
929	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
930	>	V v;
931	>	if ((v = p.val) == value || (v != null && value.equals(v)))
932		return true;
933		}
815	–	boolean cleanSweep = true;
816	–	if (mcsum != 0) {
817	–	for (int i = 0; i < segments.length; ++i) {
818	–	int c = segments[i].count;
819	–	if (mc[i] != segments[i].modCount) {
820	–	cleanSweep = false;
821	–	break;
822	–	}
823	–	}
824	–	}
825	–	if (cleanSweep)
826	–	return false;
934		}
935	<	// Resort to locking all segments
829	<	for (int i = 0; i < segments.length; ++i)
830	<	segments[i].lock();
831	<	boolean found = false;
832	<	try {
833	<	for (int i = 0; i < segments.length; ++i) {
834	<	if (segments[i].containsValue(value)) {
835	<	found = true;
836	<	break;
837	<	}
838	<	}
839	<	} finally {
840	<	for (int i = 0; i < segments.length; ++i)
841	<	segments[i].unlock();
842	<	}
843	<	return found;
844	<	}
845	<
846	<	/**
847	<	* Legacy method testing if some key maps into the specified value
848	<	* in this table.  This method is identical in functionality to
849	<	* {@link #containsValue}, and exists solely to ensure
850	<	* full compatibility with class {@link java.util.Hashtable},
851	<	* which supported this method prior to introduction of the
852	<	* Java Collections framework.
853	<
854	<	* @param  value a value to search for
855	<	* @return <tt>true</tt> if and only if some key maps to the
856	<	*         <tt>value</tt> argument in this table as
857	<	*         determined by the <tt>equals</tt> method;
858	<	*         <tt>false</tt> otherwise
859	<	* @throws NullPointerException if the specified value is null
860	<	*/
861	<	public boolean contains(Object value) {
862	<	return containsValue(value);
935	>	return false;
936		}
937
938		/**
939		* Maps the specified key to the specified value in this table.
940		* Neither the key nor the value can be null.
941		*
942	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
942	>	* <p>The value can be retrieved by calling the {@code get} method
943		* with a key that is equal to the original key.
944		*
945		* @param key key with which the specified value is to be associated
946		* @param value value to be associated with the specified key
947	<	* @return the previous value associated with <tt>key</tt>, or
948	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
947	>	* @return the previous value associated with {@code key}, or
948	>	*         {@code null} if there was no mapping for {@code key}
949		* @throws NullPointerException if the specified key or value is null
950		*/
951		public V put(K key, V value) {
952	<	if (value == null)
880	<	throw new NullPointerException();
881	<	int hash = hash(key.hashCode());
882	<	return segmentFor(hash).put(key, hash, value, false);
952	>	return putVal(key, value, false);
953		}
954
955	<	/**
956	<	* {@inheritDoc}
957	<	*
958	<	* @return the previous value associated with the specified key,
959	<	*         or <tt>null</tt> if there was no mapping for the key
960	<	* @throws NullPointerException if the specified key or value is null
961	<	*/
962	<	public V putIfAbsent(K key, V value) {
963	<	if (value == null)
964	<	throw new NullPointerException();
965	<	int hash = hash(key.hashCode());
966	<	return segmentFor(hash).put(key, hash, value, true);
955	>	/** Implementation for put and putIfAbsent */
956	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
957	>	if (key == null || value == null) throw new NullPointerException();
958	>	int hash = spread(key.hashCode());
959	>	int binCount = 0;
960	>	for (Node<K,V>[] tab = table;;) {
961	>	Node<K,V> f; int n, i, fh;
962	>	if (tab == null || (n = tab.length) == 0)
963	>	tab = initTable();
964	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
965	>	if (casTabAt(tab, i, null,
966	>	new Node<K,V>(hash, key, value, null)))
967	>	break;                   // no lock when adding to empty bin
968	>	}
969	>	else if ((fh = f.hash) == MOVED)
970	>	tab = helpTransfer(tab, f);
971	>	else {
972	>	V oldVal = null;
973	>	synchronized (f) {
974	>	if (tabAt(tab, i) == f) {
975	>	if (fh >= 0) {
976	>	binCount = 1;
977	>	for (Node<K,V> e = f;; ++binCount) {
978	>	K ek;
979	>	if (e.hash == hash &&
980	>	((ek = e.key) == key ||
981	>	(ek != null && key.equals(ek)))) {
982	>	oldVal = e.val;
983	>	if (!onlyIfAbsent)
984	>	e.val = value;
985	>	break;
986	>	}
987	>	Node<K,V> pred = e;
988	>	if ((e = e.next) == null) {
989	>	pred.next = new Node<K,V>(hash, key,
990	>	value, null);
991	>	break;
992	>	}
993	>	}
994	>	}
995	>	else if (f instanceof TreeBin) {
996	>	Node<K,V> p;
997	>	binCount = 2;
998	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
999	>	value)) != null) {
1000	>	oldVal = p.val;
1001	>	if (!onlyIfAbsent)
1002	>	p.val = value;
1003	>	}
1004	>	}
1005	>	}
1006	>	}
1007	>	if (binCount != 0) {
1008	>	if (binCount >= TREEIFY_THRESHOLD)
1009	>	treeifyBin(tab, i);
1010	>	if (oldVal != null)
1011	>	return oldVal;
1012	>	break;
1013	>	}
1014	>	}
1015	>	}
1016	>	addCount(1L, binCount);
1017	>	return null;
1018		}
1019
1020		/**
#	Line 904 | Line 1025 | public class ConcurrentHashMap<K, V> ext
1025		* @param m mappings to be stored in this map
1026		*/
1027		public void putAll(Map<? extends K, ? extends V> m) {
1028	+	tryPresize(m.size());
1029		for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1030	<	put(e.getKey(), e.getValue());
1030	>	putVal(e.getKey(), e.getValue(), false);
1031		}
1032
1033		/**
#	Line 913 | Line 1035 | public class ConcurrentHashMap<K, V> ext
1035		* This method does nothing if the key is not in the map.
1036		*
1037		* @param  key the key that needs to be removed
1038	<	* @return the previous value associated with <tt>key</tt>, or
1039	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1038	>	* @return the previous value associated with {@code key}, or
1039	>	*         {@code null} if there was no mapping for {@code key}
1040		* @throws NullPointerException if the specified key is null
1041		*/
1042		public V remove(Object key) {
1043	<	int hash = hash(key.hashCode());
922	<	return segmentFor(hash).remove(key, hash, null);
923	<	}
924	<
925	<	/**
926	<	* {@inheritDoc}
927	<	*
928	<	* @throws NullPointerException if the specified key is null
929	<	*/
930	<	public boolean remove(Object key, Object value) {
931	<	int hash = hash(key.hashCode());
932	<	if (value == null)
933	<	return false;
934	<	return segmentFor(hash).remove(key, hash, value) != null;
935	<	}
936	<
937	<	/**
938	<	* {@inheritDoc}
939	<	*
940	<	* @throws NullPointerException if any of the arguments are null
941	<	*/
942	<	public boolean replace(K key, V oldValue, V newValue) {
943	<	if (oldValue == null || newValue == null)
944	<	throw new NullPointerException();
945	<	int hash = hash(key.hashCode());
946	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
1043	>	return replaceNode(key, null, null);
1044		}
1045
1046		/**
1047	<	* {@inheritDoc}
1048	<	*
1049	<	* @return the previous value associated with the specified key,
1050	<	*         or <tt>null</tt> if there was no mapping for the key
1051	<	* @throws NullPointerException if the specified key or value is null
1052	<	*/
1053	<	public V replace(K key, V value) {
1054	<	if (value == null)
1055	<	throw new NullPointerException();
1056	<	int hash = hash(key.hashCode());
1057	<	return segmentFor(hash).replace(key, hash, value);
1047	>	* Implementation for the four public remove/replace methods:
1048	>	* Replaces node value with v, conditional upon match of cv if
1049	>	* non-null.  If resulting value is null, delete.
1050	>	*/
1051	>	final V replaceNode(Object key, V value, Object cv) {
1052	>	int hash = spread(key.hashCode());
1053	>	for (Node<K,V>[] tab = table;;) {
1054	>	Node<K,V> f; int n, i, fh;
1055	>	if (tab == null || (n = tab.length) == 0 ||
1056	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1057	>	break;
1058	>	else if ((fh = f.hash) == MOVED)
1059	>	tab = helpTransfer(tab, f);
1060	>	else {
1061	>	V oldVal = null;
1062	>	boolean validated = false;
1063	>	synchronized (f) {
1064	>	if (tabAt(tab, i) == f) {
1065	>	if (fh >= 0) {
1066	>	validated = true;
1067	>	for (Node<K,V> e = f, pred = null;;) {
1068	>	K ek;
1069	>	if (e.hash == hash &&
1070	>	((ek = e.key) == key ||
1071	>	(ek != null && key.equals(ek)))) {
1072	>	V ev = e.val;
1073	>	if (cv == null || cv == ev ||
1074	>	(ev != null && cv.equals(ev))) {
1075	>	oldVal = ev;
1076	>	if (value != null)
1077	>	e.val = value;
1078	>	else if (pred != null)
1079	>	pred.next = e.next;
1080	>	else
1081	>	setTabAt(tab, i, e.next);
1082	>	}
1083	>	break;
1084	>	}
1085	>	pred = e;
1086	>	if ((e = e.next) == null)
1087	>	break;
1088	>	}
1089	>	}
1090	>	else if (f instanceof TreeBin) {
1091	>	validated = true;
1092	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1093	>	TreeNode<K,V> r, p;
1094	>	if ((r = t.root) != null &&
1095	>	(p = r.findTreeNode(hash, key, null)) != null) {
1096	>	V pv = p.val;
1097	>	if (cv == null || cv == pv ||
1098	>	(pv != null && cv.equals(pv))) {
1099	>	oldVal = pv;
1100	>	if (value != null)
1101	>	p.val = value;
1102	>	else if (t.removeTreeNode(p))
1103	>	setTabAt(tab, i, untreeify(t.first));
1104	>	}
1105	>	}
1106	>	}
1107	>	}
1108	>	}
1109	>	if (validated) {
1110	>	if (oldVal != null) {
1111	>	if (value == null)
1112	>	addCount(-1L, -1);
1113	>	return oldVal;
1114	>	}
1115	>	break;
1116	>	}
1117	>	}
1118	>	}
1119	>	return null;
1120		}
1121
1122		/**
1123		* Removes all of the mappings from this map.
1124		*/
1125		public void clear() {
1126	<	for (int i = 0; i < segments.length; ++i)
1127	<	segments[i].clear();
1126	>	long delta = 0L; // negative number of deletions
1127	>	int i = 0;
1128	>	Node<K,V>[] tab = table;
1129	>	while (tab != null && i < tab.length) {
1130	>	int fh;
1131	>	Node<K,V> f = tabAt(tab, i);
1132	>	if (f == null)
1133	>	++i;
1134	>	else if ((fh = f.hash) == MOVED) {
1135	>	tab = helpTransfer(tab, f);
1136	>	i = 0; // restart
1137	>	}
1138	>	else {
1139	>	synchronized (f) {
1140	>	if (tabAt(tab, i) == f) {
1141	>	Node<K,V> p = (fh >= 0 ? f :
1142	>	(f instanceof TreeBin) ?
1143	>	((TreeBin<K,V>)f).first : null);
1144	>	while (p != null) {
1145	>	--delta;
1146	>	p = p.next;
1147	>	}
1148	>	setTabAt(tab, i++, null);
1149	>	}
1150	>	}
1151	>	}
1152	>	}
1153	>	if (delta != 0L)
1154	>	addCount(delta, -1);
1155		}
1156
1157		/**
1158		* Returns a {@link Set} view of the keys contained in this map.
1159		* The set is backed by the map, so changes to the map are
1160	<	* reflected in the set, and vice-versa.  The set supports element
1160	>	* reflected in the set, and vice-versa. The set supports element
1161		* removal, which removes the corresponding mapping from this map,
1162	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1163	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1164	<	* operations.  It does not support the <tt>add</tt> or
1165	<	* <tt>addAll</tt> operations.
1162	>	* via the {@code Iterator.remove}, {@code Set.remove},
1163	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1164	>	* operations.  It does not support the {@code add} or
1165	>	* {@code addAll} operations.
1166		*
1167	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1167	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1168		* that will never throw {@link ConcurrentModificationException},
1169		* and guarantees to traverse elements as they existed upon
1170		* construction of the iterator, and may (but is not guaranteed to)
1171		* reflect any modifications subsequent to construction.
1172	+	*
1173	+	* @return the set view
1174		*/
1175	<	public Set<K> keySet() {
1176	<	Set<K> ks = keySet;
1177	<	return (ks != null) ? ks : (keySet = new KeySet());
1175	>	public KeySetView<K,V> keySet() {
1176	>	KeySetView<K,V> ks;
1177	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1178		}
1179
1180		/**
#	Line 994 | Line 1182 | public class ConcurrentHashMap<K, V> ext
1182		* The collection is backed by the map, so changes to the map are
1183		* reflected in the collection, and vice-versa.  The collection
1184		* supports element removal, which removes the corresponding
1185	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1186	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1187	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1188	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1185	>	* mapping from this map, via the {@code Iterator.remove},
1186	>	* {@code Collection.remove}, {@code removeAll},
1187	>	* {@code retainAll}, and {@code clear} operations.  It does not
1188	>	* support the {@code add} or {@code addAll} operations.
1189		*
1190	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1190	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1191		* that will never throw {@link ConcurrentModificationException},
1192		* and guarantees to traverse elements as they existed upon
1193		* construction of the iterator, and may (but is not guaranteed to)
1194		* reflect any modifications subsequent to construction.
1195	+	*
1196	+	* @return the collection view
1197		*/
1198		public Collection<V> values() {
1199	<	Collection<V> vs = values;
1200	<	return (vs != null) ? vs : (values = new Values());
1199	>	ValuesView<K,V> vs;
1200	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1201		}
1202
1203		/**
#	Line 1015 | Line 1205 | public class ConcurrentHashMap<K, V> ext
1205		* The set is backed by the map, so changes to the map are
1206		* reflected in the set, and vice-versa.  The set supports element
1207		* removal, which removes the corresponding mapping from the map,
1208	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1209	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1210	<	* operations.  It does not support the <tt>add</tt> or
1021	<	* <tt>addAll</tt> operations.
1208	>	* via the {@code Iterator.remove}, {@code Set.remove},
1209	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1210	>	* operations.
1211		*
1212	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1212	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1213		* that will never throw {@link ConcurrentModificationException},
1214		* and guarantees to traverse elements as they existed upon
1215		* construction of the iterator, and may (but is not guaranteed to)
1216		* reflect any modifications subsequent to construction.
1217	+	*
1218	+	* @return the set view
1219		*/
1220		public Set<Map.Entry<K,V>> entrySet() {
1221	<	Set<Map.Entry<K,V>> es = entrySet;
1222	<	return (es != null) ? es : (entrySet = new EntrySet());
1221	>	EntrySetView<K,V> es;
1222	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1223	>	}
1224	>
1225	>	/**
1226	>	* Returns the hash code value for this {@link Map}, i.e.,
1227	>	* the sum of, for each key-value pair in the map,
1228	>	* {@code key.hashCode() ^ value.hashCode()}.
1229	>	*
1230	>	* @return the hash code value for this map
1231	>	*/
1232	>	public int hashCode() {
1233	>	int h = 0;
1234	>	Node<K,V>[] t;
1235	>	if ((t = table) != null) {
1236	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1237	>	for (Node<K,V> p; (p = it.advance()) != null; )
1238	>	h += p.key.hashCode() ^ p.val.hashCode();
1239	>	}
1240	>	return h;
1241	>	}
1242	>
1243	>	/**
1244	>	* Returns a string representation of this map.  The string
1245	>	* representation consists of a list of key-value mappings (in no
1246	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1247	>	* mappings are separated by the characters {@code ", "} (comma
1248	>	* and space).  Each key-value mapping is rendered as the key
1249	>	* followed by an equals sign ("{@code =}") followed by the
1250	>	* associated value.
1251	>	*
1252	>	* @return a string representation of this map
1253	>	*/
1254	>	public String toString() {
1255	>	Node<K,V>[] t;
1256	>	int f = (t = table) == null ? 0 : t.length;
1257	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1258	>	StringBuilder sb = new StringBuilder();
1259	>	sb.append('{');
1260	>	Node<K,V> p;
1261	>	if ((p = it.advance()) != null) {
1262	>	for (;;) {
1263	>	K k = p.key;
1264	>	V v = p.val;
1265	>	sb.append(k == this ? "(this Map)" : k);
1266	>	sb.append('=');
1267	>	sb.append(v == this ? "(this Map)" : v);
1268	>	if ((p = it.advance()) == null)
1269	>	break;
1270	>	sb.append(',').append(' ');
1271	>	}
1272	>	}
1273	>	return sb.append('}').toString();
1274	>	}
1275	>
1276	>	/**
1277	>	* Compares the specified object with this map for equality.
1278	>	* Returns {@code true} if the given object is a map with the same
1279	>	* mappings as this map.  This operation may return misleading
1280	>	* results if either map is concurrently modified during execution
1281	>	* of this method.
1282	>	*
1283	>	* @param o object to be compared for equality with this map
1284	>	* @return {@code true} if the specified object is equal to this map
1285	>	*/
1286	>	public boolean equals(Object o) {
1287	>	if (o != this) {
1288	>	if (!(o instanceof Map))
1289	>	return false;
1290	>	Map<?,?> m = (Map<?,?>) o;
1291	>	Node<K,V>[] t;
1292	>	int f = (t = table) == null ? 0 : t.length;
1293	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1294	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1295	>	V val = p.val;
1296	>	Object v = m.get(p.key);
1297	>	if (v == null || (v != val && !v.equals(val)))
1298	>	return false;
1299	>	}
1300	>	for (Map.Entry<?,?> e : m.entrySet()) {
1301	>	Object mk, mv, v;
1302	>	if ((mk = e.getKey()) == null ||
1303	>	(mv = e.getValue()) == null ||
1304	>	(v = get(mk)) == null ||
1305	>	(mv != v && !mv.equals(v)))
1306	>	return false;
1307	>	}
1308	>	}
1309	>	return true;
1310	>	}
1311	>
1312	>	/**
1313	>	* Stripped-down version of helper class used in previous version,
1314	>	* declared for the sake of serialization compatibility
1315	>	*/
1316	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1317	>	private static final long serialVersionUID = 2249069246763182397L;
1318	>	final float loadFactor;
1319	>	Segment(float lf) { this.loadFactor = lf; }
1320	>	}
1321	>
1322	>	/**
1323	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1324	>	* stream (i.e., serializes it).
1325	>	* @param s the stream
1326	>	* @serialData
1327	>	* the key (Object) and value (Object)
1328	>	* for each key-value mapping, followed by a null pair.
1329	>	* The key-value mappings are emitted in no particular order.
1330	>	*/
1331	>	private void writeObject(java.io.ObjectOutputStream s)
1332	>	throws java.io.IOException {
1333	>	// For serialization compatibility
1334	>	// Emulate segment calculation from previous version of this class
1335	>	int sshift = 0;
1336	>	int ssize = 1;
1337	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1338	>	++sshift;
1339	>	ssize <<= 1;
1340	>	}
1341	>	int segmentShift = 32 - sshift;
1342	>	int segmentMask = ssize - 1;
1343	>	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1344	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1345	>	for (int i = 0; i < segments.length; ++i)
1346	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1347	>	s.putFields().put("segments", segments);
1348	>	s.putFields().put("segmentShift", segmentShift);
1349	>	s.putFields().put("segmentMask", segmentMask);
1350	>	s.writeFields();
1351	>
1352	>	Node<K,V>[] t;
1353	>	if ((t = table) != null) {
1354	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1355	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1356	>	s.writeObject(p.key);
1357	>	s.writeObject(p.val);
1358	>	}
1359	>	}
1360	>	s.writeObject(null);
1361	>	s.writeObject(null);
1362	>	segments = null; // throw away
1363	>	}
1364	>
1365	>	/**
1366	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1367	>	* @param s the stream
1368	>	*/
1369	>	private void readObject(java.io.ObjectInputStream s)
1370	>	throws java.io.IOException, ClassNotFoundException {
1371	>	/*
1372	>	* To improve performance in typical cases, we create nodes
1373	>	* while reading, then place in table once size is known.
1374	>	* However, we must also validate uniqueness and deal with
1375	>	* overpopulated bins while doing so, which requires
1376	>	* specialized versions of putVal mechanics.
1377	>	*/
1378	>	sizeCtl = -1; // force exclusion for table construction
1379	>	s.defaultReadObject();
1380	>	long size = 0L;
1381	>	Node<K,V> p = null;
1382	>	for (;;) {
1383	>	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1384	>	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1385	>	if (k != null && v != null) {
1386	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1387	>	++size;
1388	>	}
1389	>	else
1390	>	break;
1391	>	}
1392	>	if (size == 0L)
1393	>	sizeCtl = 0;
1394	>	else {
1395	>	int n;
1396	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1397	>	n = MAXIMUM_CAPACITY;
1398	>	else {
1399	>	int sz = (int)size;
1400	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1401	>	}
1402	>	@SuppressWarnings({"rawtypes","unchecked"})
1403	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1404	>	int mask = n - 1;
1405	>	long added = 0L;
1406	>	while (p != null) {
1407	>	boolean insertAtFront;
1408	>	Node<K,V> next = p.next, first;
1409	>	int h = p.hash, j = h & mask;
1410	>	if ((first = tabAt(tab, j)) == null)
1411	>	insertAtFront = true;
1412	>	else {
1413	>	K k = p.key;
1414	>	if (first.hash < 0) {
1415	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1416	>	if (t.putTreeVal(h, k, p.val) == null)
1417	>	++added;
1418	>	insertAtFront = false;
1419	>	}
1420	>	else {
1421	>	int binCount = 0;
1422	>	insertAtFront = true;
1423	>	Node<K,V> q; K qk;
1424	>	for (q = first; q != null; q = q.next) {
1425	>	if (q.hash == h &&
1426	>	((qk = q.key) == k ||
1427	>	(qk != null && k.equals(qk)))) {
1428	>	insertAtFront = false;
1429	>	break;
1430	>	}
1431	>	++binCount;
1432	>	}
1433	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1434	>	insertAtFront = false;
1435	>	++added;
1436	>	p.next = first;
1437	>	TreeNode<K,V> hd = null, tl = null;
1438	>	for (q = p; q != null; q = q.next) {
1439	>	TreeNode<K,V> t = new TreeNode<K,V>
1440	>	(q.hash, q.key, q.val, null, null);
1441	>	if ((t.prev = tl) == null)
1442	>	hd = t;
1443	>	else
1444	>	tl.next = t;
1445	>	tl = t;
1446	>	}
1447	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1448	>	}
1449	>	}
1450	>	}
1451	>	if (insertAtFront) {
1452	>	++added;
1453	>	p.next = first;
1454	>	setTabAt(tab, j, p);
1455	>	}
1456	>	p = next;
1457	>	}
1458	>	table = tab;
1459	>	sizeCtl = n - (n >>> 2);
1460	>	baseCount = added;
1461	>	}
1462	>	}
1463	>
1464	>	// ConcurrentMap methods
1465	>
1466	>	/**
1467	>	* {@inheritDoc}
1468	>	*
1469	>	* @return the previous value associated with the specified key,
1470	>	*         or {@code null} if there was no mapping for the key
1471	>	* @throws NullPointerException if the specified key or value is null
1472	>	*/
1473	>	public V putIfAbsent(K key, V value) {
1474	>	return putVal(key, value, true);
1475	>	}
1476	>
1477	>	/**
1478	>	* {@inheritDoc}
1479	>	*
1480	>	* @throws NullPointerException if the specified key is null
1481	>	*/
1482	>	public boolean remove(Object key, Object value) {
1483	>	if (key == null)
1484	>	throw new NullPointerException();
1485	>	return value != null && replaceNode(key, null, value) != null;
1486	>	}
1487	>
1488	>	/**
1489	>	* {@inheritDoc}
1490	>	*
1491	>	* @throws NullPointerException if any of the arguments are null
1492	>	*/
1493	>	public boolean replace(K key, V oldValue, V newValue) {
1494	>	if (key == null || oldValue == null || newValue == null)
1495	>	throw new NullPointerException();
1496	>	return replaceNode(key, newValue, oldValue) != null;
1497	>	}
1498	>
1499	>	/**
1500	>	* {@inheritDoc}
1501	>	*
1502	>	* @return the previous value associated with the specified key,
1503	>	*         or {@code null} if there was no mapping for the key
1504	>	* @throws NullPointerException if the specified key or value is null
1505	>	*/
1506	>	public V replace(K key, V value) {
1507	>	if (key == null || value == null)
1508	>	throw new NullPointerException();
1509	>	return replaceNode(key, value, null);
1510	>	}
1511	>
1512	>	// Overrides of JDK8+ Map extension method defaults
1513	>
1514	>	/**
1515	>	* Returns the value to which the specified key is mapped, or the
1516	>	* given default value if this map contains no mapping for the
1517	>	* key.
1518	>	*
1519	>	* @param key the key whose associated value is to be returned
1520	>	* @param defaultValue the value to return if this map contains
1521	>	* no mapping for the given key
1522	>	* @return the mapping for the key, if present; else the default value
1523	>	* @throws NullPointerException if the specified key is null
1524	>	*/
1525	>	public V getOrDefault(Object key, V defaultValue) {
1526	>	V v;
1527	>	return (v = get(key)) == null ? defaultValue : v;
1528	>	}
1529	>
1530	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1531	>	if (action == null) throw new NullPointerException();
1532	>	Node<K,V>[] t;
1533	>	if ((t = table) != null) {
1534	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1535	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1536	>	action.accept(p.key, p.val);
1537	>	}
1538	>	}
1539	>	}
1540	>
1541	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1542	>	if (function == null) throw new NullPointerException();
1543	>	Node<K,V>[] t;
1544	>	if ((t = table) != null) {
1545	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1546	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1547	>	V oldValue = p.val;
1548	>	for (K key = p.key;;) {
1549	>	V newValue = function.apply(key, oldValue);
1550	>	if (newValue == null)
1551	>	throw new NullPointerException();
1552	>	if (replaceNode(key, newValue, oldValue) != null ||
1553	>	(oldValue = get(key)) == null)
1554	>	break;
1555	>	}
1556	>	}
1557	>	}
1558	>	}
1559	>
1560	>	/**
1561	>	* If the specified key is not already associated with a value,
1562	>	* attempts to compute its value using the given mapping function
1563	>	* and enters it into this map unless {@code null}.  The entire
1564	>	* method invocation is performed atomically, so the function is
1565	>	* applied at most once per key.  Some attempted update operations
1566	>	* on this map by other threads may be blocked while computation
1567	>	* is in progress, so the computation should be short and simple,
1568	>	* and must not attempt to update any other mappings of this map.
1569	>	*
1570	>	* @param key key with which the specified value is to be associated
1571	>	* @param mappingFunction the function to compute a value
1572	>	* @return the current (existing or computed) value associated with
1573	>	*         the specified key, or null if the computed value is null
1574	>	* @throws NullPointerException if the specified key or mappingFunction
1575	>	*         is null
1576	>	* @throws IllegalStateException if the computation detectably
1577	>	*         attempts a recursive update to this map that would
1578	>	*         otherwise never complete
1579	>	* @throws RuntimeException or Error if the mappingFunction does so,
1580	>	*         in which case the mapping is left unestablished
1581	>	*/
1582	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1583	>	if (key == null || mappingFunction == null)
1584	>	throw new NullPointerException();
1585	>	int h = spread(key.hashCode());
1586	>	V val = null;
1587	>	int binCount = 0;
1588	>	for (Node<K,V>[] tab = table;;) {
1589	>	Node<K,V> f; int n, i, fh;
1590	>	if (tab == null || (n = tab.length) == 0)
1591	>	tab = initTable();
1592	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1593	>	Node<K,V> r = new ReservationNode<K,V>();
1594	>	synchronized (r) {
1595	>	if (casTabAt(tab, i, null, r)) {
1596	>	binCount = 1;
1597	>	Node<K,V> node = null;
1598	>	try {
1599	>	if ((val = mappingFunction.apply(key)) != null)
1600	>	node = new Node<K,V>(h, key, val, null);
1601	>	} finally {
1602	>	setTabAt(tab, i, node);
1603	>	}
1604	>	}
1605	>	}
1606	>	if (binCount != 0)
1607	>	break;
1608	>	}
1609	>	else if ((fh = f.hash) == MOVED)
1610	>	tab = helpTransfer(tab, f);
1611	>	else {
1612	>	boolean added = false;
1613	>	synchronized (f) {
1614	>	if (tabAt(tab, i) == f) {
1615	>	if (fh >= 0) {
1616	>	binCount = 1;
1617	>	for (Node<K,V> e = f;; ++binCount) {
1618	>	K ek; V ev;
1619	>	if (e.hash == h &&
1620	>	((ek = e.key) == key ||
1621	>	(ek != null && key.equals(ek)))) {
1622	>	val = e.val;
1623	>	break;
1624	>	}
1625	>	Node<K,V> pred = e;
1626	>	if ((e = e.next) == null) {
1627	>	if ((val = mappingFunction.apply(key)) != null) {
1628	>	added = true;
1629	>	pred.next = new Node<K,V>(h, key, val, null);
1630	>	}
1631	>	break;
1632	>	}
1633	>	}
1634	>	}
1635	>	else if (f instanceof TreeBin) {
1636	>	binCount = 2;
1637	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1638	>	TreeNode<K,V> r, p;
1639	>	if ((r = t.root) != null &&
1640	>	(p = r.findTreeNode(h, key, null)) != null)
1641	>	val = p.val;
1642	>	else if ((val = mappingFunction.apply(key)) != null) {
1643	>	added = true;
1644	>	t.putTreeVal(h, key, val);
1645	>	}
1646	>	}
1647	>	}
1648	>	}
1649	>	if (binCount != 0) {
1650	>	if (binCount >= TREEIFY_THRESHOLD)
1651	>	treeifyBin(tab, i);
1652	>	if (!added)
1653	>	return val;
1654	>	break;
1655	>	}
1656	>	}
1657	>	}
1658	>	if (val != null)
1659	>	addCount(1L, binCount);
1660	>	return val;
1661	>	}
1662	>
1663	>	/**
1664	>	* If the value for the specified key is present, attempts to
1665	>	* compute a new mapping given the key and its current mapped
1666	>	* value.  The entire method invocation is performed atomically.
1667	>	* Some attempted update operations on this map by other threads
1668	>	* may be blocked while computation is in progress, so the
1669	>	* computation should be short and simple, and must not attempt to
1670	>	* update any other mappings of this map.
1671	>	*
1672	>	* @param key key with which a value may be associated
1673	>	* @param remappingFunction the function to compute a value
1674	>	* @return the new value associated with the specified key, or null if none
1675	>	* @throws NullPointerException if the specified key or remappingFunction
1676	>	*         is null
1677	>	* @throws IllegalStateException if the computation detectably
1678	>	*         attempts a recursive update to this map that would
1679	>	*         otherwise never complete
1680	>	* @throws RuntimeException or Error if the remappingFunction does so,
1681	>	*         in which case the mapping is unchanged
1682	>	*/
1683	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1684	>	if (key == null || remappingFunction == null)
1685	>	throw new NullPointerException();
1686	>	int h = spread(key.hashCode());
1687	>	V val = null;
1688	>	int delta = 0;
1689	>	int binCount = 0;
1690	>	for (Node<K,V>[] tab = table;;) {
1691	>	Node<K,V> f; int n, i, fh;
1692	>	if (tab == null || (n = tab.length) == 0)
1693	>	tab = initTable();
1694	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1695	>	break;
1696	>	else if ((fh = f.hash) == MOVED)
1697	>	tab = helpTransfer(tab, f);
1698	>	else {
1699	>	synchronized (f) {
1700	>	if (tabAt(tab, i) == f) {
1701	>	if (fh >= 0) {
1702	>	binCount = 1;
1703	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1704	>	K ek;
1705	>	if (e.hash == h &&
1706	>	((ek = e.key) == key ||
1707	>	(ek != null && key.equals(ek)))) {
1708	>	val = remappingFunction.apply(key, e.val);
1709	>	if (val != null)
1710	>	e.val = val;
1711	>	else {
1712	>	delta = -1;
1713	>	Node<K,V> en = e.next;
1714	>	if (pred != null)
1715	>	pred.next = en;
1716	>	else
1717	>	setTabAt(tab, i, en);
1718	>	}
1719	>	break;
1720	>	}
1721	>	pred = e;
1722	>	if ((e = e.next) == null)
1723	>	break;
1724	>	}
1725	>	}
1726	>	else if (f instanceof TreeBin) {
1727	>	binCount = 2;
1728	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1729	>	TreeNode<K,V> r, p;
1730	>	if ((r = t.root) != null &&
1731	>	(p = r.findTreeNode(h, key, null)) != null) {
1732	>	val = remappingFunction.apply(key, p.val);
1733	>	if (val != null)
1734	>	p.val = val;
1735	>	else {
1736	>	delta = -1;
1737	>	if (t.removeTreeNode(p))
1738	>	setTabAt(tab, i, untreeify(t.first));
1739	>	}
1740	>	}
1741	>	}
1742	>	}
1743	>	}
1744	>	if (binCount != 0)
1745	>	break;
1746	>	}
1747	>	}
1748	>	if (delta != 0)
1749	>	addCount((long)delta, binCount);
1750	>	return val;
1751	>	}
1752	>
1753	>	/**
1754	>	* Attempts to compute a mapping for the specified key and its
1755	>	* current mapped value (or {@code null} if there is no current
1756	>	* mapping). The entire method invocation is performed atomically.
1757	>	* Some attempted update operations on this map by other threads
1758	>	* may be blocked while computation is in progress, so the
1759	>	* computation should be short and simple, and must not attempt to
1760	>	* update any other mappings of this Map.
1761	>	*
1762	>	* @param key key with which the specified value is to be associated
1763	>	* @param remappingFunction the function to compute a value
1764	>	* @return the new value associated with the specified key, or null if none
1765	>	* @throws NullPointerException if the specified key or remappingFunction
1766	>	*         is null
1767	>	* @throws IllegalStateException if the computation detectably
1768	>	*         attempts a recursive update to this map that would
1769	>	*         otherwise never complete
1770	>	* @throws RuntimeException or Error if the remappingFunction does so,
1771	>	*         in which case the mapping is unchanged
1772	>	*/
1773	>	public V compute(K key,
1774	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1775	>	if (key == null || remappingFunction == null)
1776	>	throw new NullPointerException();
1777	>	int h = spread(key.hashCode());
1778	>	V val = null;
1779	>	int delta = 0;
1780	>	int binCount = 0;
1781	>	for (Node<K,V>[] tab = table;;) {
1782	>	Node<K,V> f; int n, i, fh;
1783	>	if (tab == null || (n = tab.length) == 0)
1784	>	tab = initTable();
1785	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1786	>	Node<K,V> r = new ReservationNode<K,V>();
1787	>	synchronized (r) {
1788	>	if (casTabAt(tab, i, null, r)) {
1789	>	binCount = 1;
1790	>	Node<K,V> node = null;
1791	>	try {
1792	>	if ((val = remappingFunction.apply(key, null)) != null) {
1793	>	delta = 1;
1794	>	node = new Node<K,V>(h, key, val, null);
1795	>	}
1796	>	} finally {
1797	>	setTabAt(tab, i, node);
1798	>	}
1799	>	}
1800	>	}
1801	>	if (binCount != 0)
1802	>	break;
1803	>	}
1804	>	else if ((fh = f.hash) == MOVED)
1805	>	tab = helpTransfer(tab, f);
1806	>	else {
1807	>	synchronized (f) {
1808	>	if (tabAt(tab, i) == f) {
1809	>	if (fh >= 0) {
1810	>	binCount = 1;
1811	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1812	>	K ek;
1813	>	if (e.hash == h &&
1814	>	((ek = e.key) == key ||
1815	>	(ek != null && key.equals(ek)))) {
1816	>	val = remappingFunction.apply(key, e.val);
1817	>	if (val != null)
1818	>	e.val = val;
1819	>	else {
1820	>	delta = -1;
1821	>	Node<K,V> en = e.next;
1822	>	if (pred != null)
1823	>	pred.next = en;
1824	>	else
1825	>	setTabAt(tab, i, en);
1826	>	}
1827	>	break;
1828	>	}
1829	>	pred = e;
1830	>	if ((e = e.next) == null) {
1831	>	val = remappingFunction.apply(key, null);
1832	>	if (val != null) {
1833	>	delta = 1;
1834	>	pred.next =
1835	>	new Node<K,V>(h, key, val, null);
1836	>	}
1837	>	break;
1838	>	}
1839	>	}
1840	>	}
1841	>	else if (f instanceof TreeBin) {
1842	>	binCount = 1;
1843	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1844	>	TreeNode<K,V> r, p;
1845	>	if ((r = t.root) != null)
1846	>	p = r.findTreeNode(h, key, null);
1847	>	else
1848	>	p = null;
1849	>	V pv = (p == null) ? null : p.val;
1850	>	val = remappingFunction.apply(key, pv);
1851	>	if (val != null) {
1852	>	if (p != null)
1853	>	p.val = val;
1854	>	else {
1855	>	delta = 1;
1856	>	t.putTreeVal(h, key, val);
1857	>	}
1858	>	}
1859	>	else if (p != null) {
1860	>	delta = -1;
1861	>	if (t.removeTreeNode(p))
1862	>	setTabAt(tab, i, untreeify(t.first));
1863	>	}
1864	>	}
1865	>	}
1866	>	}
1867	>	if (binCount != 0) {
1868	>	if (binCount >= TREEIFY_THRESHOLD)
1869	>	treeifyBin(tab, i);
1870	>	break;
1871	>	}
1872	>	}
1873	>	}
1874	>	if (delta != 0)
1875	>	addCount((long)delta, binCount);
1876	>	return val;
1877	>	}
1878	>
1879	>	/**
1880	>	* If the specified key is not already associated with a
1881	>	* (non-null) value, associates it with the given value.
1882	>	* Otherwise, replaces the value with the results of the given
1883	>	* remapping function, or removes if {@code null}. The entire
1884	>	* method invocation is performed atomically.  Some attempted
1885	>	* update operations on this map by other threads may be blocked
1886	>	* while computation is in progress, so the computation should be
1887	>	* short and simple, and must not attempt to update any other
1888	>	* mappings of this Map.
1889	>	*
1890	>	* @param key key with which the specified value is to be associated
1891	>	* @param value the value to use if absent
1892	>	* @param remappingFunction the function to recompute a value if present
1893	>	* @return the new value associated with the specified key, or null if none
1894	>	* @throws NullPointerException if the specified key or the
1895	>	*         remappingFunction is null
1896	>	* @throws RuntimeException or Error if the remappingFunction does so,
1897	>	*         in which case the mapping is unchanged
1898	>	*/
1899	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1900	>	if (key == null || value == null || remappingFunction == null)
1901	>	throw new NullPointerException();
1902	>	int h = spread(key.hashCode());
1903	>	V val = null;
1904	>	int delta = 0;
1905	>	int binCount = 0;
1906	>	for (Node<K,V>[] tab = table;;) {
1907	>	Node<K,V> f; int n, i, fh;
1908	>	if (tab == null || (n = tab.length) == 0)
1909	>	tab = initTable();
1910	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1911	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1912	>	delta = 1;
1913	>	val = value;
1914	>	break;
1915	>	}
1916	>	}
1917	>	else if ((fh = f.hash) == MOVED)
1918	>	tab = helpTransfer(tab, f);
1919	>	else {
1920	>	synchronized (f) {
1921	>	if (tabAt(tab, i) == f) {
1922	>	if (fh >= 0) {
1923	>	binCount = 1;
1924	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1925	>	K ek;
1926	>	if (e.hash == h &&
1927	>	((ek = e.key) == key ||
1928	>	(ek != null && key.equals(ek)))) {
1929	>	val = remappingFunction.apply(e.val, value);
1930	>	if (val != null)
1931	>	e.val = val;
1932	>	else {
1933	>	delta = -1;
1934	>	Node<K,V> en = e.next;
1935	>	if (pred != null)
1936	>	pred.next = en;
1937	>	else
1938	>	setTabAt(tab, i, en);
1939	>	}
1940	>	break;
1941	>	}
1942	>	pred = e;
1943	>	if ((e = e.next) == null) {
1944	>	delta = 1;
1945	>	val = value;
1946	>	pred.next =
1947	>	new Node<K,V>(h, key, val, null);
1948	>	break;
1949	>	}
1950	>	}
1951	>	}
1952	>	else if (f instanceof TreeBin) {
1953	>	binCount = 2;
1954	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1955	>	TreeNode<K,V> r = t.root;
1956	>	TreeNode<K,V> p = (r == null) ? null :
1957	>	r.findTreeNode(h, key, null);
1958	>	val = (p == null) ? value :
1959	>	remappingFunction.apply(p.val, value);
1960	>	if (val != null) {
1961	>	if (p != null)
1962	>	p.val = val;
1963	>	else {
1964	>	delta = 1;
1965	>	t.putTreeVal(h, key, val);
1966	>	}
1967	>	}
1968	>	else if (p != null) {
1969	>	delta = -1;
1970	>	if (t.removeTreeNode(p))
1971	>	setTabAt(tab, i, untreeify(t.first));
1972	>	}
1973	>	}
1974	>	}
1975	>	}
1976	>	if (binCount != 0) {
1977	>	if (binCount >= TREEIFY_THRESHOLD)
1978	>	treeifyBin(tab, i);
1979	>	break;
1980	>	}
1981	>	}
1982	>	}
1983	>	if (delta != 0)
1984	>	addCount((long)delta, binCount);
1985	>	return val;
1986	>	}
1987	>
1988	>	// Hashtable legacy methods
1989	>
1990	>	/**
1991	>	* Legacy method testing if some key maps into the specified value
1992	>	* in this table.  This method is identical in functionality to
1993	>	* {@link #containsValue(Object)}, and exists solely to ensure
1994	>	* full compatibility with class {@link java.util.Hashtable},
1995	>	* which supported this method prior to introduction of the
1996	>	* Java Collections framework.
1997	>	*
1998	>	* @param  value a value to search for
1999	>	* @return {@code true} if and only if some key maps to the
2000	>	*         {@code value} argument in this table as
2001	>	*         determined by the {@code equals} method;
2002	>	*         {@code false} otherwise
2003	>	* @throws NullPointerException if the specified value is null
2004	>	*/
2005	>	@Deprecated public boolean contains(Object value) {
2006	>	return containsValue(value);
2007		}
2008
2009		/**
2010		* Returns an enumeration of the keys in this table.
2011		*
2012		* @return an enumeration of the keys in this table
2013	<	* @see #keySet
2013	>	* @see #keySet()
2014		*/
2015		public Enumeration<K> keys() {
2016	<	return new KeyIterator();
2016	>	Node<K,V>[] t;
2017	>	int f = (t = table) == null ? 0 : t.length;
2018	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2019		}
2020
2021		/**
2022		* Returns an enumeration of the values in this table.
2023		*
2024		* @return an enumeration of the values in this table
2025	<	* @see #values
2025	>	* @see #values()
2026		*/
2027		public Enumeration<V> elements() {
2028	<	return new ValueIterator();
2028	>	Node<K,V>[] t;
2029	>	int f = (t = table) == null ? 0 : t.length;
2030	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2031		}
2032
2033	<	/* ---------------- Iterator Support -------------- */
2033	>	// ConcurrentHashMap-only methods
2034
2035	<	abstract class HashIterator {
2036	<	int nextSegmentIndex;
2037	<	int nextTableIndex;
2038	<	HashEntry<K,V>[] currentTable;
2039	<	HashEntry<K, V> nextEntry;
2040	<	HashEntry<K, V> lastReturned;
2035	>	/**
2036	>	* Returns the number of mappings. This method should be used
2037	>	* instead of {@link #size} because a ConcurrentHashMap may
2038	>	* contain more mappings than can be represented as an int. The
2039	>	* value returned is an estimate; the actual count may differ if
2040	>	* there are concurrent insertions or removals.
2041	>	*
2042	>	* @return the number of mappings
2043	>	* @since 1.8
2044	>	*/
2045	>	public long mappingCount() {
2046	>	long n = sumCount();
2047	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2048	>	}
2049
2050	<	HashIterator() {
2051	<	nextSegmentIndex = segments.length - 1;
2052	<	nextTableIndex = -1;
2053	<	advance();
2050	>	/**
2051	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2052	>	* from the given type to {@code Boolean.TRUE}.
2053	>	*
2054	>	* @return the new set
2055	>	* @since 1.8
2056	>	*/
2057	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2058	>	return new KeySetView<K,Boolean>
2059	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2060	>	}
2061	>
2062	>	/**
2063	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2064	>	* from the given type to {@code Boolean.TRUE}.
2065	>	*
2066	>	* @param initialCapacity The implementation performs internal
2067	>	* sizing to accommodate this many elements.
2068	>	* @throws IllegalArgumentException if the initial capacity of
2069	>	* elements is negative
2070	>	* @return the new set
2071	>	* @since 1.8
2072	>	*/
2073	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2074	>	return new KeySetView<K,Boolean>
2075	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2076	>	}
2077	>
2078	>	/**
2079	>	* Returns a {@link Set} view of the keys in this map, using the
2080	>	* given common mapped value for any additions (i.e., {@link
2081	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2082	>	* This is of course only appropriate if it is acceptable to use
2083	>	* the same value for all additions from this view.
2084	>	*
2085	>	* @param mappedValue the mapped value to use for any additions
2086	>	* @return the set view
2087	>	* @throws NullPointerException if the mappedValue is null
2088	>	*/
2089	>	public KeySetView<K,V> keySet(V mappedValue) {
2090	>	if (mappedValue == null)
2091	>	throw new NullPointerException();
2092	>	return new KeySetView<K,V>(this, mappedValue);
2093	>	}
2094	>
2095	>	/* ---------------- Special Nodes -------------- */
2096	>
2097	>	/**
2098	>	* A node inserted at head of bins during transfer operations.
2099	>	*/
2100	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2101	>	final Node<K,V>[] nextTable;
2102	>	ForwardingNode(Node<K,V>[] tab) {
2103	>	super(MOVED, null, null, null);
2104	>	this.nextTable = tab;
2105	>	}
2106	>
2107	>	Node<K,V> find(int h, Object k) {
2108	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2109	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2110	>	Node<K,V> e; int n;
2111	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2112	>	(e = tabAt(tab, (n - 1) & h)) == null)
2113	>	return null;
2114	>	for (;;) {
2115	>	int eh; K ek;
2116	>	if ((eh = e.hash) == h &&
2117	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2118	>	return e;
2119	>	if (eh < 0) {
2120	>	if (e instanceof ForwardingNode) {
2121	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2122	>	continue outer;
2123	>	}
2124	>	else
2125	>	return e.find(h, k);
2126	>	}
2127	>	if ((e = e.next) == null)
2128	>	return null;
2129	>	}
2130	>	}
2131	>	}
2132	>	}
2133	>
2134	>	/**
2135	>	* A place-holder node used in computeIfAbsent and compute
2136	>	*/
2137	>	static final class ReservationNode<K,V> extends Node<K,V> {
2138	>	ReservationNode() {
2139	>	super(RESERVED, null, null, null);
2140	>	}
2141	>
2142	>	Node<K,V> find(int h, Object k) {
2143	>	return null;
2144		}
2145	+	}
2146
2147	<	public boolean hasMoreElements() { return hasNext(); }
2147	>	/* ---------------- Table Initialization and Resizing -------------- */
2148
2149	<	final void advance() {
2150	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
2149	>	/**
2150	>	* Initializes table, using the size recorded in sizeCtl.
2151	>	*/
2152	>	private final Node<K,V>[] initTable() {
2153	>	Node<K,V>[] tab; int sc;
2154	>	while ((tab = table) == null || tab.length == 0) {
2155	>	if ((sc = sizeCtl) < 0)
2156	>	Thread.yield(); // lost initialization race; just spin
2157	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2158	>	try {
2159	>	if ((tab = table) == null || tab.length == 0) {
2160	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2161	>	@SuppressWarnings({"rawtypes","unchecked"})
2162	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2163	>	table = tab = nt;
2164	>	sc = n - (n >>> 2);
2165	>	}
2166	>	} finally {
2167	>	sizeCtl = sc;
2168	>	}
2169	>	break;
2170	>	}
2171	>	}
2172	>	return tab;
2173	>	}
2174	>
2175	>	/**
2176	>	* Adds to count, and if table is too small and not already
2177	>	* resizing, initiates transfer. If already resizing, helps
2178	>	* perform transfer if work is available.  Rechecks occupancy
2179	>	* after a transfer to see if another resize is already needed
2180	>	* because resizings are lagging additions.
2181	>	*
2182	>	* @param x the count to add
2183	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2184	>	*/
2185	>	private final void addCount(long x, int check) {
2186	>	CounterCell[] as; long b, s;
2187	>	if ((as = counterCells) != null ||
2188	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2189	>	CounterCell a; long v; int m;
2190	>	boolean uncontended = true;
2191	>	if (as == null || (m = as.length - 1) < 0 ||
2192	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2193	>	!(uncontended =
2194	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2195	>	fullAddCount(x, uncontended);
2196	>	return;
2197	>	}
2198	>	if (check <= 1)
2199		return;
2200	+	s = sumCount();
2201	+	}
2202	+	if (check >= 0) {
2203	+	Node<K,V>[] tab, nt; int sc;
2204	+	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2205	+	tab.length < MAXIMUM_CAPACITY) {
2206	+	if (sc < 0) {
2207	+	if (sc == -1 || transferIndex <= transferOrigin ||
2208	+	(nt = nextTable) == null)
2209	+	break;
2210	+	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2211	+	transfer(tab, nt);
2212	+	}
2213	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2214	+	transfer(tab, null);
2215	+	s = sumCount();
2216	+	}
2217	+	}
2218	+	}
2219
2220	<	while (nextTableIndex >= 0) {
2221	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
2222	<	return;
2220	>	/**
2221	>	* Helps transfer if a resize is in progress.
2222	>	*/
2223	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2224	>	Node<K,V>[] nextTab; int sc;
2225	>	if ((f instanceof ForwardingNode) &&
2226	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2227	>	if (nextTab == nextTable && tab == table &&
2228	>	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2229	>	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2230	>	transfer(tab, nextTab);
2231	>	return nextTab;
2232	>	}
2233	>	return table;
2234	>	}
2235	>
2236	>	/**
2237	>	* Tries to presize table to accommodate the given number of elements.
2238	>	*
2239	>	* @param size number of elements (doesn't need to be perfectly accurate)
2240	>	*/
2241	>	private final void tryPresize(int size) {
2242	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2243	>	tableSizeFor(size + (size >>> 1) + 1);
2244	>	int sc;
2245	>	while ((sc = sizeCtl) >= 0) {
2246	>	Node<K,V>[] tab = table; int n;
2247	>	if (tab == null || (n = tab.length) == 0) {
2248	>	n = (sc > c) ? sc : c;
2249	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2250	>	try {
2251	>	if (table == tab) {
2252	>	@SuppressWarnings({"rawtypes","unchecked"})
2253	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2254	>	table = nt;
2255	>	sc = n - (n >>> 2);
2256	>	}
2257	>	} finally {
2258	>	sizeCtl = sc;
2259	>	}
2260	>	}
2261		}
2262	+	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2263	+	break;
2264	+	else if (tab == table &&
2265	+	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2266	+	transfer(tab, null);
2267	+	}
2268	+	}
2269
2270	<	while (nextSegmentIndex >= 0) {
2271	<	Segment<K,V> seg = segments[nextSegmentIndex--];
2272	<	if (seg.count != 0) {
2273	<	currentTable = seg.table;
2274	<	for (int j = currentTable.length - 1; j >= 0; --j) {
2275	<	if ( (nextEntry = currentTable[j]) != null) {
2276	<	nextTableIndex = j - 1;
2270	>	/**
2271	>	* Moves and/or copies the nodes in each bin to new table. See
2272	>	* above for explanation.
2273	>	*/
2274	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2275	>	int n = tab.length, stride;
2276	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2277	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2278	>	if (nextTab == null) {            // initiating
2279	>	try {
2280	>	@SuppressWarnings({"rawtypes","unchecked"})
2281	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2282	>	nextTab = nt;
2283	>	} catch (Throwable ex) {      // try to cope with OOME
2284	>	sizeCtl = Integer.MAX_VALUE;
2285	>	return;
2286	>	}
2287	>	nextTable = nextTab;
2288	>	transferOrigin = n;
2289	>	transferIndex = n;
2290	>	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2291	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
2292	>	int nextk = (k > stride) ? k - stride : 0;
2293	>	for (int m = nextk; m < k; ++m)
2294	>	nextTab[m] = rev;
2295	>	for (int m = n + nextk; m < n + k; ++m)
2296	>	nextTab[m] = rev;
2297	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2298	>	}
2299	>	}
2300	>	int nextn = nextTab.length;
2301	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2302	>	boolean advance = true;
2303	>	boolean finishing = false; // to ensure sweep before committing nextTab
2304	>	for (int i = 0, bound = 0;;) {
2305	>	int nextIndex, nextBound, fh; Node<K,V> f;
2306	>	while (advance) {
2307	>	if (--i >= bound || finishing)
2308	>	advance = false;
2309	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
2310	>	i = -1;
2311	>	advance = false;
2312	>	}
2313	>	else if (U.compareAndSwapInt
2314	>	(this, TRANSFERINDEX, nextIndex,
2315	>	nextBound = (nextIndex > stride ?
2316	>	nextIndex - stride : 0))) {
2317	>	bound = nextBound;
2318	>	i = nextIndex - 1;
2319	>	advance = false;
2320	>	}
2321	>	}
2322	>	if (i < 0 || i >= n || i + n >= nextn) {
2323	>	if (finishing) {
2324	>	nextTable = null;
2325	>	table = nextTab;
2326	>	sizeCtl = (n << 1) - (n >>> 1);
2327	>	return;
2328	>	}
2329	>	for (int sc;;) {
2330	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2331	>	if (sc != -1)
2332		return;
2333	+	finishing = advance = true;
2334	+	i = n; // recheck before commit
2335	+	break;
2336	+	}
2337	+	}
2338	+	}
2339	+	else if ((f = tabAt(tab, i)) == null) {
2340	+	if (casTabAt(tab, i, null, fwd)) {
2341	+	setTabAt(nextTab, i, null);
2342	+	setTabAt(nextTab, i + n, null);
2343	+	advance = true;
2344	+	}
2345	+	}
2346	+	else if ((fh = f.hash) == MOVED)
2347	+	advance = true; // already processed
2348	+	else {
2349	+	synchronized (f) {
2350	+	if (tabAt(tab, i) == f) {
2351	+	Node<K,V> ln, hn;
2352	+	if (fh >= 0) {
2353	+	int runBit = fh & n;
2354	+	Node<K,V> lastRun = f;
2355	+	for (Node<K,V> p = f.next; p != null; p = p.next) {
2356	+	int b = p.hash & n;
2357	+	if (b != runBit) {
2358	+	runBit = b;
2359	+	lastRun = p;
2360	+	}
2361	+	}
2362	+	if (runBit == 0) {
2363	+	ln = lastRun;
2364	+	hn = null;
2365	+	}
2366	+	else {
2367	+	hn = lastRun;
2368	+	ln = null;
2369	+	}
2370	+	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2371	+	int ph = p.hash; K pk = p.key; V pv = p.val;
2372	+	if ((ph & n) == 0)
2373	+	ln = new Node<K,V>(ph, pk, pv, ln);
2374	+	else
2375	+	hn = new Node<K,V>(ph, pk, pv, hn);
2376	+	}
2377	+	setTabAt(nextTab, i, ln);
2378	+	setTabAt(nextTab, i + n, hn);
2379	+	setTabAt(tab, i, fwd);
2380	+	advance = true;
2381	+	}
2382	+	else if (f instanceof TreeBin) {
2383	+	TreeBin<K,V> t = (TreeBin<K,V>)f;
2384	+	TreeNode<K,V> lo = null, loTail = null;
2385	+	TreeNode<K,V> hi = null, hiTail = null;
2386	+	int lc = 0, hc = 0;
2387	+	for (Node<K,V> e = t.first; e != null; e = e.next) {
2388	+	int h = e.hash;
2389	+	TreeNode<K,V> p = new TreeNode<K,V>
2390	+	(h, e.key, e.val, null, null);
2391	+	if ((h & n) == 0) {
2392	+	if ((p.prev = loTail) == null)
2393	+	lo = p;
2394	+	else
2395	+	loTail.next = p;
2396	+	loTail = p;
2397	+	++lc;
2398	+	}
2399	+	else {
2400	+	if ((p.prev = hiTail) == null)
2401	+	hi = p;
2402	+	else
2403	+	hiTail.next = p;
2404	+	hiTail = p;
2405	+	++hc;
2406	+	}
2407	+	}
2408	+	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2409	+	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2410	+	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2411	+	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2412	+	setTabAt(nextTab, i, ln);
2413	+	setTabAt(nextTab, i + n, hn);
2414	+	setTabAt(tab, i, fwd);
2415	+	advance = true;
2416		}
2417		}
2418		}
2419		}
2420		}
2421	+	}
2422
2423	<	public boolean hasNext() { return nextEntry != null; }
2423	>	/* ---------------- Counter support -------------- */
2424
2425	<	HashEntry<K,V> nextEntry() {
2426	<	if (nextEntry == null)
2427	<	throw new NoSuchElementException();
2428	<	lastReturned = nextEntry;
2425	>	/**
2426	>	* A padded cell for distributing counts.  Adapted from LongAdder
2427	>	* and Striped64.  See their internal docs for explanation.
2428	>	*/
2429	>	@sun.misc.Contended static final class CounterCell {
2430	>	volatile long value;
2431	>	CounterCell(long x) { value = x; }
2432	>	}
2433	>
2434	>	final long sumCount() {
2435	>	CounterCell[] as = counterCells; CounterCell a;
2436	>	long sum = baseCount;
2437	>	if (as != null) {
2438	>	for (int i = 0; i < as.length; ++i) {
2439	>	if ((a = as[i]) != null)
2440	>	sum += a.value;
2441	>	}
2442	>	}
2443	>	return sum;
2444	>	}
2445	>
2446	>	// See LongAdder version for explanation
2447	>	private final void fullAddCount(long x, boolean wasUncontended) {
2448	>	int h;
2449	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2450	>	ThreadLocalRandom.localInit();      // force initialization
2451	>	h = ThreadLocalRandom.getProbe();
2452	>	wasUncontended = true;
2453	>	}
2454	>	boolean collide = false;                // True if last slot nonempty
2455	>	for (;;) {
2456	>	CounterCell[] as; CounterCell a; int n; long v;
2457	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2458	>	if ((a = as[(n - 1) & h]) == null) {
2459	>	if (cellsBusy == 0) {            // Try to attach new Cell
2460	>	CounterCell r = new CounterCell(x); // Optimistic create
2461	>	if (cellsBusy == 0 &&
2462	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2463	>	boolean created = false;
2464	>	try {               // Recheck under lock
2465	>	CounterCell[] rs; int m, j;
2466	>	if ((rs = counterCells) != null &&
2467	>	(m = rs.length) > 0 &&
2468	>	rs[j = (m - 1) & h] == null) {
2469	>	rs[j] = r;
2470	>	created = true;
2471	>	}
2472	>	} finally {
2473	>	cellsBusy = 0;
2474	>	}
2475	>	if (created)
2476	>	break;
2477	>	continue;           // Slot is now non-empty
2478	>	}
2479	>	}
2480	>	collide = false;
2481	>	}
2482	>	else if (!wasUncontended)       // CAS already known to fail
2483	>	wasUncontended = true;      // Continue after rehash
2484	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2485	>	break;
2486	>	else if (counterCells != as || n >= NCPU)
2487	>	collide = false;            // At max size or stale
2488	>	else if (!collide)
2489	>	collide = true;
2490	>	else if (cellsBusy == 0 &&
2491	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2492	>	try {
2493	>	if (counterCells == as) {// Expand table unless stale
2494	>	CounterCell[] rs = new CounterCell[n << 1];
2495	>	for (int i = 0; i < n; ++i)
2496	>	rs[i] = as[i];
2497	>	counterCells = rs;
2498	>	}
2499	>	} finally {
2500	>	cellsBusy = 0;
2501	>	}
2502	>	collide = false;
2503	>	continue;                   // Retry with expanded table
2504	>	}
2505	>	h = ThreadLocalRandom.advanceProbe(h);
2506	>	}
2507	>	else if (cellsBusy == 0 && counterCells == as &&
2508	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2509	>	boolean init = false;
2510	>	try {                           // Initialize table
2511	>	if (counterCells == as) {
2512	>	CounterCell[] rs = new CounterCell[2];
2513	>	rs[h & 1] = new CounterCell(x);
2514	>	counterCells = rs;
2515	>	init = true;
2516	>	}
2517	>	} finally {
2518	>	cellsBusy = 0;
2519	>	}
2520	>	if (init)
2521	>	break;
2522	>	}
2523	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2524	>	break;                          // Fall back on using base
2525	>	}
2526	>	}
2527	>
2528	>	/* ---------------- Conversion from/to TreeBins -------------- */
2529	>
2530	>	/**
2531	>	* Replaces all linked nodes in bin at given index unless table is
2532	>	* too small, in which case resizes instead.
2533	>	*/
2534	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2535	>	Node<K,V> b; int n, sc;
2536	>	if (tab != null) {
2537	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY) {
2538	>	if (tab == table && (sc = sizeCtl) >= 0 &&
2539	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2540	>	transfer(tab, null);
2541	>	}
2542	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2543	>	synchronized (b) {
2544	>	if (tabAt(tab, index) == b) {
2545	>	TreeNode<K,V> hd = null, tl = null;
2546	>	for (Node<K,V> e = b; e != null; e = e.next) {
2547	>	TreeNode<K,V> p =
2548	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2549	>	null, null);
2550	>	if ((p.prev = tl) == null)
2551	>	hd = p;
2552	>	else
2553	>	tl.next = p;
2554	>	tl = p;
2555	>	}
2556	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2557	>	}
2558	>	}
2559	>	}
2560	>	}
2561	>	}
2562	>
2563	>	/**
2564	>	* Returns a list on non-TreeNodes replacing those in given list.
2565	>	*/
2566	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2567	>	Node<K,V> hd = null, tl = null;
2568	>	for (Node<K,V> q = b; q != null; q = q.next) {
2569	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2570	>	if (tl == null)
2571	>	hd = p;
2572	>	else
2573	>	tl.next = p;
2574	>	tl = p;
2575	>	}
2576	>	return hd;
2577	>	}
2578	>
2579	>	/* ---------------- TreeNodes -------------- */
2580	>
2581	>	/**
2582	>	* Nodes for use in TreeBins
2583	>	*/
2584	>	static final class TreeNode<K,V> extends Node<K,V> {
2585	>	TreeNode<K,V> parent;  // red-black tree links
2586	>	TreeNode<K,V> left;
2587	>	TreeNode<K,V> right;
2588	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2589	>	boolean red;
2590	>
2591	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2592	>	TreeNode<K,V> parent) {
2593	>	super(hash, key, val, next);
2594	>	this.parent = parent;
2595	>	}
2596	>
2597	>	Node<K,V> find(int h, Object k) {
2598	>	return findTreeNode(h, k, null);
2599	>	}
2600	>
2601	>	/**
2602	>	* Returns the TreeNode (or null if not found) for the given key
2603	>	* starting at given root.
2604	>	*/
2605	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2606	>	if (k != null) {
2607	>	TreeNode<K,V> p = this;
2608	>	do  {
2609	>	int ph, dir; K pk; TreeNode<K,V> q;
2610	>	TreeNode<K,V> pl = p.left, pr = p.right;
2611	>	if ((ph = p.hash) > h)
2612	>	p = pl;
2613	>	else if (ph < h)
2614	>	p = pr;
2615	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2616	>	return p;
2617	>	else if (pl == null && pr == null)
2618	>	break;
2619	>	else if ((kc != null ||
2620	>	(kc = comparableClassFor(k)) != null) &&
2621	>	(dir = compareComparables(kc, k, pk)) != 0)
2622	>	p = (dir < 0) ? pl : pr;
2623	>	else if (pl == null)
2624	>	p = pr;
2625	>	else if (pr == null ||
2626	>	(q = pr.findTreeNode(h, k, kc)) == null)
2627	>	p = pl;
2628	>	else
2629	>	return q;
2630	>	} while (p != null);
2631	>	}
2632	>	return null;
2633	>	}
2634	>	}
2635	>
2636	>	/* ---------------- TreeBins -------------- */
2637	>
2638	>	/**
2639	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2640	>	* keys or values, but instead point to list of TreeNodes and
2641	>	* their root. They also maintain a parasitic read-write lock
2642	>	* forcing writers (who hold bin lock) to wait for readers (who do
2643	>	* not) to complete before tree restructuring operations.
2644	>	*/
2645	>	static final class TreeBin<K,V> extends Node<K,V> {
2646	>	TreeNode<K,V> root;
2647	>	volatile TreeNode<K,V> first;
2648	>	volatile Thread waiter;
2649	>	volatile int lockState;
2650	>	// values for lockState
2651	>	static final int WRITER = 1; // set while holding write lock
2652	>	static final int WAITER = 2; // set when waiting for write lock
2653	>	static final int READER = 4; // increment value for setting read lock
2654	>
2655	>	/**
2656	>	* Creates bin with initial set of nodes headed by b.
2657	>	*/
2658	>	TreeBin(TreeNode<K,V> b) {
2659	>	super(TREEBIN, null, null, null);
2660	>	this.first = b;
2661	>	TreeNode<K,V> r = null;
2662	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2663	>	next = (TreeNode<K,V>)x.next;
2664	>	x.left = x.right = null;
2665	>	if (r == null) {
2666	>	x.parent = null;
2667	>	x.red = false;
2668	>	r = x;
2669	>	}
2670	>	else {
2671	>	Object key = x.key;
2672	>	int hash = x.hash;
2673	>	Class<?> kc = null;
2674	>	for (TreeNode<K,V> p = r;;) {
2675	>	int dir, ph;
2676	>	if ((ph = p.hash) > hash)
2677	>	dir = -1;
2678	>	else if (ph < hash)
2679	>	dir = 1;
2680	>	else if ((kc != null ||
2681	>	(kc = comparableClassFor(key)) != null))
2682	>	dir = compareComparables(kc, key, p.key);
2683	>	else
2684	>	dir = 0;
2685	>	TreeNode<K,V> xp = p;
2686	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2687	>	x.parent = xp;
2688	>	if (dir <= 0)
2689	>	xp.left = x;
2690	>	else
2691	>	xp.right = x;
2692	>	r = balanceInsertion(r, x);
2693	>	break;
2694	>	}
2695	>	}
2696	>	}
2697	>	}
2698	>	this.root = r;
2699	>	}
2700	>
2701	>	/**
2702	>	* Acquires write lock for tree restructuring.
2703	>	*/
2704	>	private final void lockRoot() {
2705	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2706	>	contendedLock(); // offload to separate method
2707	>	}
2708	>
2709	>	/**
2710	>	* Releases write lock for tree restructuring.
2711	>	*/
2712	>	private final void unlockRoot() {
2713	>	lockState = 0;
2714	>	}
2715	>
2716	>	/**
2717	>	* Possibly blocks awaiting root lock.
2718	>	*/
2719	>	private final void contendedLock() {
2720	>	boolean waiting = false;
2721	>	for (int s;;) {
2722	>	if (((s = lockState) & WRITER) == 0) {
2723	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2724	>	if (waiting)
2725	>	waiter = null;
2726	>	return;
2727	>	}
2728	>	}
2729	>	else if ((s | WAITER) == 0) {
2730	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2731	>	waiting = true;
2732	>	waiter = Thread.currentThread();
2733	>	}
2734	>	}
2735	>	else if (waiting)
2736	>	LockSupport.park(this);
2737	>	}
2738	>	}
2739	>
2740	>	/**
2741	>	* Returns matching node or null if none. Tries to search
2742	>	* using tree comparisons from root, but continues linear
2743	>	* search when lock not available.
2744	>	*/
2745	>	final Node<K,V> find(int h, Object k) {
2746	>	if (k != null) {
2747	>	for (Node<K,V> e = first; e != null; e = e.next) {
2748	>	int s; K ek;
2749	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2750	>	if (e.hash == h &&
2751	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2752	>	return e;
2753	>	}
2754	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2755	>	s + READER)) {
2756	>	TreeNode<K,V> r, p;
2757	>	try {
2758	>	p = ((r = root) == null ? null :
2759	>	r.findTreeNode(h, k, null));
2760	>	} finally {
2761	>	Thread w;
2762	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2763	>	(READER|WAITER) && (w = waiter) != null)
2764	>	LockSupport.unpark(w);
2765	>	}
2766	>	return p;
2767	>	}
2768	>	}
2769	>	}
2770	>	return null;
2771	>	}
2772	>
2773	>	/**
2774	>	* Finds or adds a node.
2775	>	* @return null if added
2776	>	*/
2777	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2778	>	Class<?> kc = null;
2779	>	for (TreeNode<K,V> p = root;;) {
2780	>	int dir, ph; K pk; TreeNode<K,V> q, pr;
2781	>	if (p == null) {
2782	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2783	>	break;
2784	>	}
2785	>	else if ((ph = p.hash) > h)
2786	>	dir = -1;
2787	>	else if (ph < h)
2788	>	dir = 1;
2789	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2790	>	return p;
2791	>	else if ((kc == null &&
2792	>	(kc = comparableClassFor(k)) == null) ||
2793	>	(dir = compareComparables(kc, k, pk)) == 0) {
2794	>	if (p.left == null)
2795	>	dir = 1;
2796	>	else if ((pr = p.right) == null ||
2797	>	(q = pr.findTreeNode(h, k, kc)) == null)
2798	>	dir = -1;
2799	>	else
2800	>	return q;
2801	>	}
2802	>	TreeNode<K,V> xp = p;
2803	>	if ((p = (dir < 0) ? p.left : p.right) == null) {
2804	>	TreeNode<K,V> x, f = first;
2805	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2806	>	if (f != null)
2807	>	f.prev = x;
2808	>	if (dir < 0)
2809	>	xp.left = x;
2810	>	else
2811	>	xp.right = x;
2812	>	if (!xp.red)
2813	>	x.red = true;
2814	>	else {
2815	>	lockRoot();
2816	>	try {
2817	>	root = balanceInsertion(root, x);
2818	>	} finally {
2819	>	unlockRoot();
2820	>	}
2821	>	}
2822	>	break;
2823	>	}
2824	>	}
2825	>	assert checkInvariants(root);
2826	>	return null;
2827	>	}
2828	>
2829	>	/**
2830	>	* Removes the given node, that must be present before this
2831	>	* call.  This is messier than typical red-black deletion code
2832	>	* because we cannot swap the contents of an interior node
2833	>	* with a leaf successor that is pinned by "next" pointers
2834	>	* that are accessible independently of lock. So instead we
2835	>	* swap the tree linkages.
2836	>	*
2837	>	* @return true if now too small, so should be untreeified
2838	>	*/
2839	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2840	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2841	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2842	>	TreeNode<K,V> r, rl;
2843	>	if (pred == null)
2844	>	first = next;
2845	>	else
2846	>	pred.next = next;
2847	>	if (next != null)
2848	>	next.prev = pred;
2849	>	if (first == null) {
2850	>	root = null;
2851	>	return true;
2852	>	}
2853	>	if ((r = root) == null || r.right == null || // too small
2854	>	(rl = r.left) == null || rl.left == null)
2855	>	return true;
2856	>	lockRoot();
2857	>	try {
2858	>	TreeNode<K,V> replacement;
2859	>	TreeNode<K,V> pl = p.left;
2860	>	TreeNode<K,V> pr = p.right;
2861	>	if (pl != null && pr != null) {
2862	>	TreeNode<K,V> s = pr, sl;
2863	>	while ((sl = s.left) != null) // find successor
2864	>	s = sl;
2865	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2866	>	TreeNode<K,V> sr = s.right;
2867	>	TreeNode<K,V> pp = p.parent;
2868	>	if (s == pr) { // p was s's direct parent
2869	>	p.parent = s;
2870	>	s.right = p;
2871	>	}
2872	>	else {
2873	>	TreeNode<K,V> sp = s.parent;
2874	>	if ((p.parent = sp) != null) {
2875	>	if (s == sp.left)
2876	>	sp.left = p;
2877	>	else
2878	>	sp.right = p;
2879	>	}
2880	>	if ((s.right = pr) != null)
2881	>	pr.parent = s;
2882	>	}
2883	>	p.left = null;
2884	>	if ((p.right = sr) != null)
2885	>	sr.parent = p;
2886	>	if ((s.left = pl) != null)
2887	>	pl.parent = s;
2888	>	if ((s.parent = pp) == null)
2889	>	r = s;
2890	>	else if (p == pp.left)
2891	>	pp.left = s;
2892	>	else
2893	>	pp.right = s;
2894	>	if (sr != null)
2895	>	replacement = sr;
2896	>	else
2897	>	replacement = p;
2898	>	}
2899	>	else if (pl != null)
2900	>	replacement = pl;
2901	>	else if (pr != null)
2902	>	replacement = pr;
2903	>	else
2904	>	replacement = p;
2905	>	if (replacement != p) {
2906	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2907	>	if (pp == null)
2908	>	r = replacement;
2909	>	else if (p == pp.left)
2910	>	pp.left = replacement;
2911	>	else
2912	>	pp.right = replacement;
2913	>	p.left = p.right = p.parent = null;
2914	>	}
2915	>
2916	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2917	>
2918	>	if (p == replacement) {  // detach pointers
2919	>	TreeNode<K,V> pp;
2920	>	if ((pp = p.parent) != null) {
2921	>	if (p == pp.left)
2922	>	pp.left = null;
2923	>	else if (p == pp.right)
2924	>	pp.right = null;
2925	>	p.parent = null;
2926	>	}
2927	>	}
2928	>	} finally {
2929	>	unlockRoot();
2930	>	}
2931	>	assert checkInvariants(root);
2932	>	return false;
2933	>	}
2934	>
2935	>	/* ------------------------------------------------------------ */
2936	>	// Red-black tree methods, all adapted from CLR
2937	>
2938	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2939	>	TreeNode<K,V> p) {
2940	>	TreeNode<K,V> r, pp, rl;
2941	>	if (p != null && (r = p.right) != null) {
2942	>	if ((rl = p.right = r.left) != null)
2943	>	rl.parent = p;
2944	>	if ((pp = r.parent = p.parent) == null)
2945	>	(root = r).red = false;
2946	>	else if (pp.left == p)
2947	>	pp.left = r;
2948	>	else
2949	>	pp.right = r;
2950	>	r.left = p;
2951	>	p.parent = r;
2952	>	}
2953	>	return root;
2954	>	}
2955	>
2956	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2957	>	TreeNode<K,V> p) {
2958	>	TreeNode<K,V> l, pp, lr;
2959	>	if (p != null && (l = p.left) != null) {
2960	>	if ((lr = p.left = l.right) != null)
2961	>	lr.parent = p;
2962	>	if ((pp = l.parent = p.parent) == null)
2963	>	(root = l).red = false;
2964	>	else if (pp.right == p)
2965	>	pp.right = l;
2966	>	else
2967	>	pp.left = l;
2968	>	l.right = p;
2969	>	p.parent = l;
2970	>	}
2971	>	return root;
2972	>	}
2973	>
2974	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2975	>	TreeNode<K,V> x) {
2976	>	x.red = true;
2977	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2978	>	if ((xp = x.parent) == null) {
2979	>	x.red = false;
2980	>	return x;
2981	>	}
2982	>	else if (!xp.red || (xpp = xp.parent) == null)
2983	>	return root;
2984	>	if (xp == (xppl = xpp.left)) {
2985	>	if ((xppr = xpp.right) != null && xppr.red) {
2986	>	xppr.red = false;
2987	>	xp.red = false;
2988	>	xpp.red = true;
2989	>	x = xpp;
2990	>	}
2991	>	else {
2992	>	if (x == xp.right) {
2993	>	root = rotateLeft(root, x = xp);
2994	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2995	>	}
2996	>	if (xp != null) {
2997	>	xp.red = false;
2998	>	if (xpp != null) {
2999	>	xpp.red = true;
3000	>	root = rotateRight(root, xpp);
3001	>	}
3002	>	}
3003	>	}
3004	>	}
3005	>	else {
3006	>	if (xppl != null && xppl.red) {
3007	>	xppl.red = false;
3008	>	xp.red = false;
3009	>	xpp.red = true;
3010	>	x = xpp;
3011	>	}
3012	>	else {
3013	>	if (x == xp.left) {
3014	>	root = rotateRight(root, x = xp);
3015	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3016	>	}
3017	>	if (xp != null) {
3018	>	xp.red = false;
3019	>	if (xpp != null) {
3020	>	xpp.red = true;
3021	>	root = rotateLeft(root, xpp);
3022	>	}
3023	>	}
3024	>	}
3025	>	}
3026	>	}
3027	>	}
3028	>
3029	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3030	>	TreeNode<K,V> x) {
3031	>	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3032	>	if (x == null || x == root)
3033	>	return root;
3034	>	else if ((xp = x.parent) == null) {
3035	>	x.red = false;
3036	>	return x;
3037	>	}
3038	>	else if (x.red) {
3039	>	x.red = false;
3040	>	return root;
3041	>	}
3042	>	else if ((xpl = xp.left) == x) {
3043	>	if ((xpr = xp.right) != null && xpr.red) {
3044	>	xpr.red = false;
3045	>	xp.red = true;
3046	>	root = rotateLeft(root, xp);
3047	>	xpr = (xp = x.parent) == null ? null : xp.right;
3048	>	}
3049	>	if (xpr == null)
3050	>	x = xp;
3051	>	else {
3052	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3053	>	if ((sr == null || !sr.red) &&
3054	>	(sl == null || !sl.red)) {
3055	>	xpr.red = true;
3056	>	x = xp;
3057	>	}
3058	>	else {
3059	>	if (sr == null || !sr.red) {
3060	>	if (sl != null)
3061	>	sl.red = false;
3062	>	xpr.red = true;
3063	>	root = rotateRight(root, xpr);
3064	>	xpr = (xp = x.parent) == null ?
3065	>	null : xp.right;
3066	>	}
3067	>	if (xpr != null) {
3068	>	xpr.red = (xp == null) ? false : xp.red;
3069	>	if ((sr = xpr.right) != null)
3070	>	sr.red = false;
3071	>	}
3072	>	if (xp != null) {
3073	>	xp.red = false;
3074	>	root = rotateLeft(root, xp);
3075	>	}
3076	>	x = root;
3077	>	}
3078	>	}
3079	>	}
3080	>	else { // symmetric
3081	>	if (xpl != null && xpl.red) {
3082	>	xpl.red = false;
3083	>	xp.red = true;
3084	>	root = rotateRight(root, xp);
3085	>	xpl = (xp = x.parent) == null ? null : xp.left;
3086	>	}
3087	>	if (xpl == null)
3088	>	x = xp;
3089	>	else {
3090	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3091	>	if ((sl == null || !sl.red) &&
3092	>	(sr == null || !sr.red)) {
3093	>	xpl.red = true;
3094	>	x = xp;
3095	>	}
3096	>	else {
3097	>	if (sl == null || !sl.red) {
3098	>	if (sr != null)
3099	>	sr.red = false;
3100	>	xpl.red = true;
3101	>	root = rotateLeft(root, xpl);
3102	>	xpl = (xp = x.parent) == null ?
3103	>	null : xp.left;
3104	>	}
3105	>	if (xpl != null) {
3106	>	xpl.red = (xp == null) ? false : xp.red;
3107	>	if ((sl = xpl.left) != null)
3108	>	sl.red = false;
3109	>	}
3110	>	if (xp != null) {
3111	>	xp.red = false;
3112	>	root = rotateRight(root, xp);
3113	>	}
3114	>	x = root;
3115	>	}
3116	>	}
3117	>	}
3118	>	}
3119	>	}
3120	>
3121	>	/**
3122	>	* Recursive invariant check
3123	>	*/
3124	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3125	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3126	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3127	>	if (tb != null && tb.next != t)
3128	>	return false;
3129	>	if (tn != null && tn.prev != t)
3130	>	return false;
3131	>	if (tp != null && t != tp.left && t != tp.right)
3132	>	return false;
3133	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3134	>	return false;
3135	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3136	>	return false;
3137	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3138	>	return false;
3139	>	if (tl != null && !checkInvariants(tl))
3140	>	return false;
3141	>	if (tr != null && !checkInvariants(tr))
3142	>	return false;
3143	>	return true;
3144	>	}
3145	>
3146	>	private static final sun.misc.Unsafe U;
3147	>	private static final long LOCKSTATE;
3148	>	static {
3149	>	try {
3150	>	U = sun.misc.Unsafe.getUnsafe();
3151	>	Class<?> k = TreeBin.class;
3152	>	LOCKSTATE = U.objectFieldOffset
3153	>	(k.getDeclaredField("lockState"));
3154	>	} catch (Exception e) {
3155	>	throw new Error(e);
3156	>	}
3157	>	}
3158	>	}
3159	>
3160	>	/* ----------------Table Traversal -------------- */
3161	>
3162	>	/**
3163	>	* Encapsulates traversal for methods such as containsValue; also
3164	>	* serves as a base class for other iterators and spliterators.
3165	>	*
3166	>	* Method advance visits once each still-valid node that was
3167	>	* reachable upon iterator construction. It might miss some that
3168	>	* were added to a bin after the bin was visited, which is OK wrt
3169	>	* consistency guarantees. Maintaining this property in the face
3170	>	* of possible ongoing resizes requires a fair amount of
3171	>	* bookkeeping state that is difficult to optimize away amidst
3172	>	* volatile accesses.  Even so, traversal maintains reasonable
3173	>	* throughput.
3174	>	*
3175	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3176	>	* However, if the table has been resized, then all future steps
3177	>	* must traverse both the bin at the current index as well as at
3178	>	* (index + baseSize); and so on for further resizings. To
3179	>	* paranoically cope with potential sharing by users of iterators
3180	>	* across threads, iteration terminates if a bounds checks fails
3181	>	* for a table read.
3182	>	*/
3183	>	static class Traverser<K,V> {
3184	>	Node<K,V>[] tab;        // current table; updated if resized
3185	>	Node<K,V> next;         // the next entry to use
3186	>	int index;              // index of bin to use next
3187	>	int baseIndex;          // current index of initial table
3188	>	int baseLimit;          // index bound for initial table
3189	>	final int baseSize;     // initial table size
3190	>
3191	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3192	>	this.tab = tab;
3193	>	this.baseSize = size;
3194	>	this.baseIndex = this.index = index;
3195	>	this.baseLimit = limit;
3196	>	this.next = null;
3197	>	}
3198	>
3199	>	/**
3200	>	* Advances if possible, returning next valid node, or null if none.
3201	>	*/
3202	>	final Node<K,V> advance() {
3203	>	Node<K,V> e;
3204	>	if ((e = next) != null)
3205	>	e = e.next;
3206	>	for (;;) {
3207	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3208	>	if (e != null)
3209	>	return next = e;
3210	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3211	>	(n = t.length) <= (i = index) || i < 0)
3212	>	return next = null;
3213	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
3214	>	if (e instanceof ForwardingNode) {
3215	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3216	>	e = null;
3217	>	continue;
3218	>	}
3219	>	else if (e instanceof TreeBin)
3220	>	e = ((TreeBin<K,V>)e).first;
3221	>	else
3222	>	e = null;
3223	>	}
3224	>	if ((index += baseSize) >= n)
3225	>	index = ++baseIndex;    // visit upper slots if present
3226	>	}
3227	>	}
3228	>	}
3229	>
3230	>	/**
3231	>	* Base of key, value, and entry Iterators. Adds fields to
3232	>	* Traverser to support iterator.remove.
3233	>	*/
3234	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3235	>	final ConcurrentHashMap<K,V> map;
3236	>	Node<K,V> lastReturned;
3237	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3238	>	ConcurrentHashMap<K,V> map) {
3239	>	super(tab, size, index, limit);
3240	>	this.map = map;
3241		advance();
1101	–	return lastReturned;
3242		}
3243
3244	<	public void remove() {
3245	<	if (lastReturned == null)
3244	>	public final boolean hasNext() { return next != null; }
3245	>	public final boolean hasMoreElements() { return next != null; }
3246	>
3247	>	public final void remove() {
3248	>	Node<K,V> p;
3249	>	if ((p = lastReturned) == null)
3250		throw new IllegalStateException();
1107	–	ConcurrentHashMap.this.remove(lastReturned.key);
3251		lastReturned = null;
3252	+	map.replaceNode(p.key, null, null);
3253		}
3254		}
3255
3256	<	final class KeyIterator
3257	<	extends HashIterator
3258	<	implements Iterator<K>, Enumeration<K>
3259	<	{
3260	<	public K next()        { return super.nextEntry().key; }
3261	<	public K nextElement() { return super.nextEntry().key; }
3256	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3257	>	implements Iterator<K>, Enumeration<K> {
3258	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3259	>	ConcurrentHashMap<K,V> map) {
3260	>	super(tab, index, size, limit, map);
3261	>	}
3262	>
3263	>	public final K next() {
3264	>	Node<K,V> p;
3265	>	if ((p = next) == null)
3266	>	throw new NoSuchElementException();
3267	>	K k = p.key;
3268	>	lastReturned = p;
3269	>	advance();
3270	>	return k;
3271	>	}
3272	>
3273	>	public final K nextElement() { return next(); }
3274		}
3275
3276	<	final class ValueIterator
3277	<	extends HashIterator
3278	<	implements Iterator<V>, Enumeration<V>
3279	<	{
3280	<	public V next()        { return super.nextEntry().value; }
3281	<	public V nextElement() { return super.nextEntry().value; }
3276	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3277	>	implements Iterator<V>, Enumeration<V> {
3278	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3279	>	ConcurrentHashMap<K,V> map) {
3280	>	super(tab, index, size, limit, map);
3281	>	}
3282	>
3283	>	public final V next() {
3284	>	Node<K,V> p;
3285	>	if ((p = next) == null)
3286	>	throw new NoSuchElementException();
3287	>	V v = p.val;
3288	>	lastReturned = p;
3289	>	advance();
3290	>	return v;
3291	>	}
3292	>
3293	>	public final V nextElement() { return next(); }
3294	>	}
3295	>
3296	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3297	>	implements Iterator<Map.Entry<K,V>> {
3298	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3299	>	ConcurrentHashMap<K,V> map) {
3300	>	super(tab, index, size, limit, map);
3301	>	}
3302	>
3303	>	public final Map.Entry<K,V> next() {
3304	>	Node<K,V> p;
3305	>	if ((p = next) == null)
3306	>	throw new NoSuchElementException();
3307	>	K k = p.key;
3308	>	V v = p.val;
3309	>	lastReturned = p;
3310	>	advance();
3311	>	return new MapEntry<K,V>(k, v, map);
3312	>	}
3313		}
3314
3315		/**
3316	<	* Custom Entry class used by EntryIterator.next(), that relays
1130	<	* setValue changes to the underlying map.
3316	>	* Exported Entry for EntryIterator
3317		*/
3318	<	final class WriteThroughEntry
3319	<	extends AbstractMap.SimpleEntry<K,V>
3320	<	{
3321	<	WriteThroughEntry(K k, V v) {
3322	<	super(k,v);
3318	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3319	>	final K key; // non-null
3320	>	V val;       // non-null
3321	>	final ConcurrentHashMap<K,V> map;
3322	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3323	>	this.key = key;
3324	>	this.val = val;
3325	>	this.map = map;
3326	>	}
3327	>	public K getKey()        { return key; }
3328	>	public V getValue()      { return val; }
3329	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3330	>	public String toString() { return key + "=" + val; }
3331	>
3332	>	public boolean equals(Object o) {
3333	>	Object k, v; Map.Entry<?,?> e;
3334	>	return ((o instanceof Map.Entry) &&
3335	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3336	>	(v = e.getValue()) != null &&
3337	>	(k == key || k.equals(key)) &&
3338	>	(v == val || v.equals(val)));
3339		}
3340
3341		/**
3342	<	* Set our entry's value and write through to the map. The
3343	<	* value to return is somewhat arbitrary here. Since a
3344	<	* WriteThroughEntry does not necessarily track asynchronous
3345	<	* changes, the most recent "previous" value could be
3346	<	* different from what we return (or could even have been
3347	<	* removed in which case the put will re-establish). We do not
1146	<	* and cannot guarantee more.
3342	>	* Sets our entry's value and writes through to the map. The
3343	>	* value to return is somewhat arbitrary here. Since we do not
3344	>	* necessarily track asynchronous changes, the most recent
3345	>	* "previous" value could be different from what we return (or
3346	>	* could even have been removed, in which case the put will
3347	>	* re-establish). We do not and cannot guarantee more.
3348		*/
3349	<	public V setValue(V value) {
3349	>	public V setValue(V value) {
3350		if (value == null) throw new NullPointerException();
3351	<	V v = super.setValue(value);
3352	<	ConcurrentHashMap.this.put(getKey(), value);
3351	>	V v = val;
3352	>	val = value;
3353	>	map.put(key, value);
3354		return v;
3355		}
3356		}
3357
3358	<	final class EntryIterator
3359	<	extends HashIterator
3360	<	implements Iterator<Entry<K,V>>
3361	<	{
3362	<	public Map.Entry<K,V> next() {
3363	<	HashEntry<K,V> e = super.nextEntry();
3364	<	return new WriteThroughEntry(e.key, e.value);
3358	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3359	>	implements Spliterator<K> {
3360	>	long est;               // size estimate
3361	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3362	>	long est) {
3363	>	super(tab, size, index, limit);
3364	>	this.est = est;
3365	>	}
3366	>
3367	>	public Spliterator<K> trySplit() {
3368	>	int i, f, h;
3369	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3370	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3371	>	f, est >>>= 1);
3372	>	}
3373	>
3374	>	public void forEachRemaining(Consumer<? super K> action) {
3375	>	if (action == null) throw new NullPointerException();
3376	>	for (Node<K,V> p; (p = advance()) != null;)
3377	>	action.accept(p.key);
3378	>	}
3379	>
3380	>	public boolean tryAdvance(Consumer<? super K> action) {
3381	>	if (action == null) throw new NullPointerException();
3382	>	Node<K,V> p;
3383	>	if ((p = advance()) == null)
3384	>	return false;
3385	>	action.accept(p.key);
3386	>	return true;
3387	>	}
3388	>
3389	>	public long estimateSize() { return est; }
3390	>
3391	>	public int characteristics() {
3392	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3393	>	Spliterator.NONNULL;
3394		}
3395		}
3396
3397	<	final class KeySet extends AbstractSet<K> {
3398	<	public Iterator<K> iterator() {
3399	<	return new KeyIterator();
3397	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3398	>	implements Spliterator<V> {
3399	>	long est;               // size estimate
3400	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3401	>	long est) {
3402	>	super(tab, size, index, limit);
3403	>	this.est = est;
3404	>	}
3405	>
3406	>	public Spliterator<V> trySplit() {
3407	>	int i, f, h;
3408	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3409	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3410	>	f, est >>>= 1);
3411	>	}
3412	>
3413	>	public void forEachRemaining(Consumer<? super V> action) {
3414	>	if (action == null) throw new NullPointerException();
3415	>	for (Node<K,V> p; (p = advance()) != null;)
3416	>	action.accept(p.val);
3417	>	}
3418	>
3419	>	public boolean tryAdvance(Consumer<? super V> action) {
3420	>	if (action == null) throw new NullPointerException();
3421	>	Node<K,V> p;
3422	>	if ((p = advance()) == null)
3423	>	return false;
3424	>	action.accept(p.val);
3425	>	return true;
3426		}
3427	<	public int size() {
3428	<	return ConcurrentHashMap.this.size();
3427	>
3428	>	public long estimateSize() { return est; }
3429	>
3430	>	public int characteristics() {
3431	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3432		}
3433	<	public boolean contains(Object o) {
3434	<	return ConcurrentHashMap.this.containsKey(o);
3433	>	}
3434	>
3435	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3436	>	implements Spliterator<Map.Entry<K,V>> {
3437	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3438	>	long est;               // size estimate
3439	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3440	>	long est, ConcurrentHashMap<K,V> map) {
3441	>	super(tab, size, index, limit);
3442	>	this.map = map;
3443	>	this.est = est;
3444	>	}
3445	>
3446	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3447	>	int i, f, h;
3448	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3449	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3450	>	f, est >>>= 1, map);
3451	>	}
3452	>
3453	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3454	>	if (action == null) throw new NullPointerException();
3455	>	for (Node<K,V> p; (p = advance()) != null; )
3456	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3457	>	}
3458	>
3459	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3460	>	if (action == null) throw new NullPointerException();
3461	>	Node<K,V> p;
3462	>	if ((p = advance()) == null)
3463	>	return false;
3464	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3465	>	return true;
3466		}
3467	<	public boolean remove(Object o) {
3468	<	return ConcurrentHashMap.this.remove(o) != null;
3467	>
3468	>	public long estimateSize() { return est; }
3469	>
3470	>	public int characteristics() {
3471	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3472	>	Spliterator.NONNULL;
3473	>	}
3474	>	}
3475	>
3476	>	// Parallel bulk operations
3477	>
3478	>	/**
3479	>	* Computes initial batch value for bulk tasks. The returned value
3480	>	* is approximately exp2 of the number of times (minus one) to
3481	>	* split task by two before executing leaf action. This value is
3482	>	* faster to compute and more convenient to use as a guide to
3483	>	* splitting than is the depth, since it is used while dividing by
3484	>	* two anyway.
3485	>	*/
3486	>	final int batchFor(long b) {
3487	>	long n;
3488	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3489	>	return 0;
3490	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3491	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3492	>	}
3493	>
3494	>	/**
3495	>	* Performs the given action for each (key, value).
3496	>	*
3497	>	* @param parallelismThreshold the (estimated) number of elements
3498	>	* needed for this operation to be executed in parallel
3499	>	* @param action the action
3500	>	* @since 1.8
3501	>	*/
3502	>	public void forEach(long parallelismThreshold,
3503	>	BiConsumer<? super K,? super V> action) {
3504	>	if (action == null) throw new NullPointerException();
3505	>	new ForEachMappingTask<K,V>
3506	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3507	>	action).invoke();
3508	>	}
3509	>
3510	>	/**
3511	>	* Performs the given action for each non-null transformation
3512	>	* of each (key, value).
3513	>	*
3514	>	* @param parallelismThreshold the (estimated) number of elements
3515	>	* needed for this operation to be executed in parallel
3516	>	* @param transformer a function returning the transformation
3517	>	* for an element, or null if there is no transformation (in
3518	>	* which case the action is not applied)
3519	>	* @param action the action
3520	>	* @since 1.8
3521	>	*/
3522	>	public <U> void forEach(long parallelismThreshold,
3523	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3524	>	Consumer<? super U> action) {
3525	>	if (transformer == null || action == null)
3526	>	throw new NullPointerException();
3527	>	new ForEachTransformedMappingTask<K,V,U>
3528	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3529	>	transformer, action).invoke();
3530	>	}
3531	>
3532	>	/**
3533	>	* Returns a non-null result from applying the given search
3534	>	* function on each (key, value), or null if none.  Upon
3535	>	* success, further element processing is suppressed and the
3536	>	* results of any other parallel invocations of the search
3537	>	* function are ignored.
3538	>	*
3539	>	* @param parallelismThreshold the (estimated) number of elements
3540	>	* needed for this operation to be executed in parallel
3541	>	* @param searchFunction a function returning a non-null
3542	>	* result on success, else null
3543	>	* @return a non-null result from applying the given search
3544	>	* function on each (key, value), or null if none
3545	>	* @since 1.8
3546	>	*/
3547	>	public <U> U search(long parallelismThreshold,
3548	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3549	>	if (searchFunction == null) throw new NullPointerException();
3550	>	return new SearchMappingsTask<K,V,U>
3551	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3552	>	searchFunction, new AtomicReference<U>()).invoke();
3553	>	}
3554	>
3555	>	/**
3556	>	* Returns the result of accumulating the given transformation
3557	>	* of all (key, value) pairs using the given reducer to
3558	>	* combine values, or null if none.
3559	>	*
3560	>	* @param parallelismThreshold the (estimated) number of elements
3561	>	* needed for this operation to be executed in parallel
3562	>	* @param transformer a function returning the transformation
3563	>	* for an element, or null if there is no transformation (in
3564	>	* which case it is not combined)
3565	>	* @param reducer a commutative associative combining function
3566	>	* @return the result of accumulating the given transformation
3567	>	* of all (key, value) pairs
3568	>	* @since 1.8
3569	>	*/
3570	>	public <U> U reduce(long parallelismThreshold,
3571	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3572	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3573	>	if (transformer == null || reducer == null)
3574	>	throw new NullPointerException();
3575	>	return new MapReduceMappingsTask<K,V,U>
3576	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3577	>	null, transformer, reducer).invoke();
3578	>	}
3579	>
3580	>	/**
3581	>	* Returns the result of accumulating the given transformation
3582	>	* of all (key, value) pairs using the given reducer to
3583	>	* combine values, and the given basis as an identity value.
3584	>	*
3585	>	* @param parallelismThreshold the (estimated) number of elements
3586	>	* needed for this operation to be executed in parallel
3587	>	* @param transformer a function returning the transformation
3588	>	* for an element
3589	>	* @param basis the identity (initial default value) for the reduction
3590	>	* @param reducer a commutative associative combining function
3591	>	* @return the result of accumulating the given transformation
3592	>	* of all (key, value) pairs
3593	>	* @since 1.8
3594	>	*/
3595	>	public double reduceToDouble(long parallelismThreshold,
3596	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3597	>	double basis,
3598	>	DoubleBinaryOperator reducer) {
3599	>	if (transformer == null || reducer == null)
3600	>	throw new NullPointerException();
3601	>	return new MapReduceMappingsToDoubleTask<K,V>
3602	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3603	>	null, transformer, basis, reducer).invoke();
3604	>	}
3605	>
3606	>	/**
3607	>	* Returns the result of accumulating the given transformation
3608	>	* of all (key, value) pairs using the given reducer to
3609	>	* combine values, and the given basis as an identity value.
3610	>	*
3611	>	* @param parallelismThreshold the (estimated) number of elements
3612	>	* needed for this operation to be executed in parallel
3613	>	* @param transformer a function returning the transformation
3614	>	* for an element
3615	>	* @param basis the identity (initial default value) for the reduction
3616	>	* @param reducer a commutative associative combining function
3617	>	* @return the result of accumulating the given transformation
3618	>	* of all (key, value) pairs
3619	>	* @since 1.8
3620	>	*/
3621	>	public long reduceToLong(long parallelismThreshold,
3622	>	ToLongBiFunction<? super K, ? super V> transformer,
3623	>	long basis,
3624	>	LongBinaryOperator reducer) {
3625	>	if (transformer == null || reducer == null)
3626	>	throw new NullPointerException();
3627	>	return new MapReduceMappingsToLongTask<K,V>
3628	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3629	>	null, transformer, basis, reducer).invoke();
3630	>	}
3631	>
3632	>	/**
3633	>	* Returns the result of accumulating the given transformation
3634	>	* of all (key, value) pairs using the given reducer to
3635	>	* combine values, and the given basis as an identity value.
3636	>	*
3637	>	* @param parallelismThreshold the (estimated) number of elements
3638	>	* needed for this operation to be executed in parallel
3639	>	* @param transformer a function returning the transformation
3640	>	* for an element
3641	>	* @param basis the identity (initial default value) for the reduction
3642	>	* @param reducer a commutative associative combining function
3643	>	* @return the result of accumulating the given transformation
3644	>	* of all (key, value) pairs
3645	>	* @since 1.8
3646	>	*/
3647	>	public int reduceToInt(long parallelismThreshold,
3648	>	ToIntBiFunction<? super K, ? super V> transformer,
3649	>	int basis,
3650	>	IntBinaryOperator reducer) {
3651	>	if (transformer == null || reducer == null)
3652	>	throw new NullPointerException();
3653	>	return new MapReduceMappingsToIntTask<K,V>
3654	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3655	>	null, transformer, basis, reducer).invoke();
3656	>	}
3657	>
3658	>	/**
3659	>	* Performs the given action for each key.
3660	>	*
3661	>	* @param parallelismThreshold the (estimated) number of elements
3662	>	* needed for this operation to be executed in parallel
3663	>	* @param action the action
3664	>	* @since 1.8
3665	>	*/
3666	>	public void forEachKey(long parallelismThreshold,
3667	>	Consumer<? super K> action) {
3668	>	if (action == null) throw new NullPointerException();
3669	>	new ForEachKeyTask<K,V>
3670	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3671	>	action).invoke();
3672	>	}
3673	>
3674	>	/**
3675	>	* Performs the given action for each non-null transformation
3676	>	* of each key.
3677	>	*
3678	>	* @param parallelismThreshold the (estimated) number of elements
3679	>	* needed for this operation to be executed in parallel
3680	>	* @param transformer a function returning the transformation
3681	>	* for an element, or null if there is no transformation (in
3682	>	* which case the action is not applied)
3683	>	* @param action the action
3684	>	* @since 1.8
3685	>	*/
3686	>	public <U> void forEachKey(long parallelismThreshold,
3687	>	Function<? super K, ? extends U> transformer,
3688	>	Consumer<? super U> action) {
3689	>	if (transformer == null || action == null)
3690	>	throw new NullPointerException();
3691	>	new ForEachTransformedKeyTask<K,V,U>
3692	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3693	>	transformer, action).invoke();
3694	>	}
3695	>
3696	>	/**
3697	>	* Returns a non-null result from applying the given search
3698	>	* function on each key, or null if none. Upon success,
3699	>	* further element processing is suppressed and the results of
3700	>	* any other parallel invocations of the search function are
3701	>	* ignored.
3702	>	*
3703	>	* @param parallelismThreshold the (estimated) number of elements
3704	>	* needed for this operation to be executed in parallel
3705	>	* @param searchFunction a function returning a non-null
3706	>	* result on success, else null
3707	>	* @return a non-null result from applying the given search
3708	>	* function on each key, or null if none
3709	>	* @since 1.8
3710	>	*/
3711	>	public <U> U searchKeys(long parallelismThreshold,
3712	>	Function<? super K, ? extends U> searchFunction) {
3713	>	if (searchFunction == null) throw new NullPointerException();
3714	>	return new SearchKeysTask<K,V,U>
3715	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3716	>	searchFunction, new AtomicReference<U>()).invoke();
3717	>	}
3718	>
3719	>	/**
3720	>	* Returns the result of accumulating all keys using the given
3721	>	* reducer to combine values, or null if none.
3722	>	*
3723	>	* @param parallelismThreshold the (estimated) number of elements
3724	>	* needed for this operation to be executed in parallel
3725	>	* @param reducer a commutative associative combining function
3726	>	* @return the result of accumulating all keys using the given
3727	>	* reducer to combine values, or null if none
3728	>	* @since 1.8
3729	>	*/
3730	>	public K reduceKeys(long parallelismThreshold,
3731	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3732	>	if (reducer == null) throw new NullPointerException();
3733	>	return new ReduceKeysTask<K,V>
3734	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3735	>	null, reducer).invoke();
3736	>	}
3737	>
3738	>	/**
3739	>	* Returns the result of accumulating the given transformation
3740	>	* of all keys using the given reducer to combine values, or
3741	>	* null if none.
3742	>	*
3743	>	* @param parallelismThreshold the (estimated) number of elements
3744	>	* needed for this operation to be executed in parallel
3745	>	* @param transformer a function returning the transformation
3746	>	* for an element, or null if there is no transformation (in
3747	>	* which case it is not combined)
3748	>	* @param reducer a commutative associative combining function
3749	>	* @return the result of accumulating the given transformation
3750	>	* of all keys
3751	>	* @since 1.8
3752	>	*/
3753	>	public <U> U reduceKeys(long parallelismThreshold,
3754	>	Function<? super K, ? extends U> transformer,
3755	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3756	>	if (transformer == null || reducer == null)
3757	>	throw new NullPointerException();
3758	>	return new MapReduceKeysTask<K,V,U>
3759	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3760	>	null, transformer, reducer).invoke();
3761	>	}
3762	>
3763	>	/**
3764	>	* Returns the result of accumulating the given transformation
3765	>	* of all keys using the given reducer to combine values, and
3766	>	* the given basis as an identity value.
3767	>	*
3768	>	* @param parallelismThreshold the (estimated) number of elements
3769	>	* needed for this operation to be executed in parallel
3770	>	* @param transformer a function returning the transformation
3771	>	* for an element
3772	>	* @param basis the identity (initial default value) for the reduction
3773	>	* @param reducer a commutative associative combining function
3774	>	* @return the result of accumulating the given transformation
3775	>	* of all keys
3776	>	* @since 1.8
3777	>	*/
3778	>	public double reduceKeysToDouble(long parallelismThreshold,
3779	>	ToDoubleFunction<? super K> transformer,
3780	>	double basis,
3781	>	DoubleBinaryOperator reducer) {
3782	>	if (transformer == null || reducer == null)
3783	>	throw new NullPointerException();
3784	>	return new MapReduceKeysToDoubleTask<K,V>
3785	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3786	>	null, transformer, basis, reducer).invoke();
3787	>	}
3788	>
3789	>	/**
3790	>	* Returns the result of accumulating the given transformation
3791	>	* of all keys using the given reducer to combine values, and
3792	>	* the given basis as an identity value.
3793	>	*
3794	>	* @param parallelismThreshold the (estimated) number of elements
3795	>	* needed for this operation to be executed in parallel
3796	>	* @param transformer a function returning the transformation
3797	>	* for an element
3798	>	* @param basis the identity (initial default value) for the reduction
3799	>	* @param reducer a commutative associative combining function
3800	>	* @return the result of accumulating the given transformation
3801	>	* of all keys
3802	>	* @since 1.8
3803	>	*/
3804	>	public long reduceKeysToLong(long parallelismThreshold,
3805	>	ToLongFunction<? super K> transformer,
3806	>	long basis,
3807	>	LongBinaryOperator reducer) {
3808	>	if (transformer == null || reducer == null)
3809	>	throw new NullPointerException();
3810	>	return new MapReduceKeysToLongTask<K,V>
3811	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3812	>	null, transformer, basis, reducer).invoke();
3813	>	}
3814	>
3815	>	/**
3816	>	* Returns the result of accumulating the given transformation
3817	>	* of all keys using the given reducer to combine values, and
3818	>	* the given basis as an identity value.
3819	>	*
3820	>	* @param parallelismThreshold the (estimated) number of elements
3821	>	* needed for this operation to be executed in parallel
3822	>	* @param transformer a function returning the transformation
3823	>	* for an element
3824	>	* @param basis the identity (initial default value) for the reduction
3825	>	* @param reducer a commutative associative combining function
3826	>	* @return the result of accumulating the given transformation
3827	>	* of all keys
3828	>	* @since 1.8
3829	>	*/
3830	>	public int reduceKeysToInt(long parallelismThreshold,
3831	>	ToIntFunction<? super K> transformer,
3832	>	int basis,
3833	>	IntBinaryOperator reducer) {
3834	>	if (transformer == null || reducer == null)
3835	>	throw new NullPointerException();
3836	>	return new MapReduceKeysToIntTask<K,V>
3837	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3838	>	null, transformer, basis, reducer).invoke();
3839	>	}
3840	>
3841	>	/**
3842	>	* Performs the given action for each value.
3843	>	*
3844	>	* @param parallelismThreshold the (estimated) number of elements
3845	>	* needed for this operation to be executed in parallel
3846	>	* @param action the action
3847	>	* @since 1.8
3848	>	*/
3849	>	public void forEachValue(long parallelismThreshold,
3850	>	Consumer<? super V> action) {
3851	>	if (action == null)
3852	>	throw new NullPointerException();
3853	>	new ForEachValueTask<K,V>
3854	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3855	>	action).invoke();
3856	>	}
3857	>
3858	>	/**
3859	>	* Performs the given action for each non-null transformation
3860	>	* of each value.
3861	>	*
3862	>	* @param parallelismThreshold the (estimated) number of elements
3863	>	* needed for this operation to be executed in parallel
3864	>	* @param transformer a function returning the transformation
3865	>	* for an element, or null if there is no transformation (in
3866	>	* which case the action is not applied)
3867	>	* @param action the action
3868	>	* @since 1.8
3869	>	*/
3870	>	public <U> void forEachValue(long parallelismThreshold,
3871	>	Function<? super V, ? extends U> transformer,
3872	>	Consumer<? super U> action) {
3873	>	if (transformer == null || action == null)
3874	>	throw new NullPointerException();
3875	>	new ForEachTransformedValueTask<K,V,U>
3876	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3877	>	transformer, action).invoke();
3878	>	}
3879	>
3880	>	/**
3881	>	* Returns a non-null result from applying the given search
3882	>	* function on each value, or null if none.  Upon success,
3883	>	* further element processing is suppressed and the results of
3884	>	* any other parallel invocations of the search function are
3885	>	* ignored.
3886	>	*
3887	>	* @param parallelismThreshold the (estimated) number of elements
3888	>	* needed for this operation to be executed in parallel
3889	>	* @param searchFunction a function returning a non-null
3890	>	* result on success, else null
3891	>	* @return a non-null result from applying the given search
3892	>	* function on each value, or null if none
3893	>	* @since 1.8
3894	>	*/
3895	>	public <U> U searchValues(long parallelismThreshold,
3896	>	Function<? super V, ? extends U> searchFunction) {
3897	>	if (searchFunction == null) throw new NullPointerException();
3898	>	return new SearchValuesTask<K,V,U>
3899	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3900	>	searchFunction, new AtomicReference<U>()).invoke();
3901	>	}
3902	>
3903	>	/**
3904	>	* Returns the result of accumulating all values using the
3905	>	* given reducer to combine values, or null if none.
3906	>	*
3907	>	* @param parallelismThreshold the (estimated) number of elements
3908	>	* needed for this operation to be executed in parallel
3909	>	* @param reducer a commutative associative combining function
3910	>	* @return the result of accumulating all values
3911	>	* @since 1.8
3912	>	*/
3913	>	public V reduceValues(long parallelismThreshold,
3914	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
3915	>	if (reducer == null) throw new NullPointerException();
3916	>	return new ReduceValuesTask<K,V>
3917	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3918	>	null, reducer).invoke();
3919	>	}
3920	>
3921	>	/**
3922	>	* Returns the result of accumulating the given transformation
3923	>	* of all values using the given reducer to combine values, or
3924	>	* null if none.
3925	>	*
3926	>	* @param parallelismThreshold the (estimated) number of elements
3927	>	* needed for this operation to be executed in parallel
3928	>	* @param transformer a function returning the transformation
3929	>	* for an element, or null if there is no transformation (in
3930	>	* which case it is not combined)
3931	>	* @param reducer a commutative associative combining function
3932	>	* @return the result of accumulating the given transformation
3933	>	* of all values
3934	>	* @since 1.8
3935	>	*/
3936	>	public <U> U reduceValues(long parallelismThreshold,
3937	>	Function<? super V, ? extends U> transformer,
3938	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3939	>	if (transformer == null || reducer == null)
3940	>	throw new NullPointerException();
3941	>	return new MapReduceValuesTask<K,V,U>
3942	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3943	>	null, transformer, reducer).invoke();
3944	>	}
3945	>
3946	>	/**
3947	>	* Returns the result of accumulating the given transformation
3948	>	* of all values using the given reducer to combine values,
3949	>	* and the given basis as an identity value.
3950	>	*
3951	>	* @param parallelismThreshold the (estimated) number of elements
3952	>	* needed for this operation to be executed in parallel
3953	>	* @param transformer a function returning the transformation
3954	>	* for an element
3955	>	* @param basis the identity (initial default value) for the reduction
3956	>	* @param reducer a commutative associative combining function
3957	>	* @return the result of accumulating the given transformation
3958	>	* of all values
3959	>	* @since 1.8
3960	>	*/
3961	>	public double reduceValuesToDouble(long parallelismThreshold,
3962	>	ToDoubleFunction<? super V> transformer,
3963	>	double basis,
3964	>	DoubleBinaryOperator reducer) {
3965	>	if (transformer == null || reducer == null)
3966	>	throw new NullPointerException();
3967	>	return new MapReduceValuesToDoubleTask<K,V>
3968	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3969	>	null, transformer, basis, reducer).invoke();
3970	>	}
3971	>
3972	>	/**
3973	>	* Returns the result of accumulating the given transformation
3974	>	* of all values using the given reducer to combine values,
3975	>	* and the given basis as an identity value.
3976	>	*
3977	>	* @param parallelismThreshold the (estimated) number of elements
3978	>	* needed for this operation to be executed in parallel
3979	>	* @param transformer a function returning the transformation
3980	>	* for an element
3981	>	* @param basis the identity (initial default value) for the reduction
3982	>	* @param reducer a commutative associative combining function
3983	>	* @return the result of accumulating the given transformation
3984	>	* of all values
3985	>	* @since 1.8
3986	>	*/
3987	>	public long reduceValuesToLong(long parallelismThreshold,
3988	>	ToLongFunction<? super V> transformer,
3989	>	long basis,
3990	>	LongBinaryOperator reducer) {
3991	>	if (transformer == null || reducer == null)
3992	>	throw new NullPointerException();
3993	>	return new MapReduceValuesToLongTask<K,V>
3994	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3995	>	null, transformer, basis, reducer).invoke();
3996	>	}
3997	>
3998	>	/**
3999	>	* Returns the result of accumulating the given transformation
4000	>	* of all values using the given reducer to combine values,
4001	>	* and the given basis as an identity value.
4002	>	*
4003	>	* @param parallelismThreshold the (estimated) number of elements
4004	>	* needed for this operation to be executed in parallel
4005	>	* @param transformer a function returning the transformation
4006	>	* for an element
4007	>	* @param basis the identity (initial default value) for the reduction
4008	>	* @param reducer a commutative associative combining function
4009	>	* @return the result of accumulating the given transformation
4010	>	* of all values
4011	>	* @since 1.8
4012	>	*/
4013	>	public int reduceValuesToInt(long parallelismThreshold,
4014	>	ToIntFunction<? super V> transformer,
4015	>	int basis,
4016	>	IntBinaryOperator reducer) {
4017	>	if (transformer == null || reducer == null)
4018	>	throw new NullPointerException();
4019	>	return new MapReduceValuesToIntTask<K,V>
4020	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4021	>	null, transformer, basis, reducer).invoke();
4022	>	}
4023	>
4024	>	/**
4025	>	* Performs the given action for each entry.
4026	>	*
4027	>	* @param parallelismThreshold the (estimated) number of elements
4028	>	* needed for this operation to be executed in parallel
4029	>	* @param action the action
4030	>	* @since 1.8
4031	>	*/
4032	>	public void forEachEntry(long parallelismThreshold,
4033	>	Consumer<? super Map.Entry<K,V>> action) {
4034	>	if (action == null) throw new NullPointerException();
4035	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4036	>	action).invoke();
4037	>	}
4038	>
4039	>	/**
4040	>	* Performs the given action for each non-null transformation
4041	>	* of each entry.
4042	>	*
4043	>	* @param parallelismThreshold the (estimated) number of elements
4044	>	* needed for this operation to be executed in parallel
4045	>	* @param transformer a function returning the transformation
4046	>	* for an element, or null if there is no transformation (in
4047	>	* which case the action is not applied)
4048	>	* @param action the action
4049	>	* @since 1.8
4050	>	*/
4051	>	public <U> void forEachEntry(long parallelismThreshold,
4052	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4053	>	Consumer<? super U> action) {
4054	>	if (transformer == null || action == null)
4055	>	throw new NullPointerException();
4056	>	new ForEachTransformedEntryTask<K,V,U>
4057	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4058	>	transformer, action).invoke();
4059	>	}
4060	>
4061	>	/**
4062	>	* Returns a non-null result from applying the given search
4063	>	* function on each entry, or null if none.  Upon success,
4064	>	* further element processing is suppressed and the results of
4065	>	* any other parallel invocations of the search function are
4066	>	* ignored.
4067	>	*
4068	>	* @param parallelismThreshold the (estimated) number of elements
4069	>	* needed for this operation to be executed in parallel
4070	>	* @param searchFunction a function returning a non-null
4071	>	* result on success, else null
4072	>	* @return a non-null result from applying the given search
4073	>	* function on each entry, or null if none
4074	>	* @since 1.8
4075	>	*/
4076	>	public <U> U searchEntries(long parallelismThreshold,
4077	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4078	>	if (searchFunction == null) throw new NullPointerException();
4079	>	return new SearchEntriesTask<K,V,U>
4080	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4081	>	searchFunction, new AtomicReference<U>()).invoke();
4082	>	}
4083	>
4084	>	/**
4085	>	* Returns the result of accumulating all entries using the
4086	>	* given reducer to combine values, or null if none.
4087	>	*
4088	>	* @param parallelismThreshold the (estimated) number of elements
4089	>	* needed for this operation to be executed in parallel
4090	>	* @param reducer a commutative associative combining function
4091	>	* @return the result of accumulating all entries
4092	>	* @since 1.8
4093	>	*/
4094	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4095	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4096	>	if (reducer == null) throw new NullPointerException();
4097	>	return new ReduceEntriesTask<K,V>
4098	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4099	>	null, reducer).invoke();
4100	>	}
4101	>
4102	>	/**
4103	>	* Returns the result of accumulating the given transformation
4104	>	* of all entries using the given reducer to combine values,
4105	>	* or null if none.
4106	>	*
4107	>	* @param parallelismThreshold the (estimated) number of elements
4108	>	* needed for this operation to be executed in parallel
4109	>	* @param transformer a function returning the transformation
4110	>	* for an element, or null if there is no transformation (in
4111	>	* which case it is not combined)
4112	>	* @param reducer a commutative associative combining function
4113	>	* @return the result of accumulating the given transformation
4114	>	* of all entries
4115	>	* @since 1.8
4116	>	*/
4117	>	public <U> U reduceEntries(long parallelismThreshold,
4118	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4119	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4120	>	if (transformer == null || reducer == null)
4121	>	throw new NullPointerException();
4122	>	return new MapReduceEntriesTask<K,V,U>
4123	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4124	>	null, transformer, reducer).invoke();
4125	>	}
4126	>
4127	>	/**
4128	>	* Returns the result of accumulating the given transformation
4129	>	* of all entries using the given reducer to combine values,
4130	>	* and the given basis as an identity value.
4131	>	*
4132	>	* @param parallelismThreshold the (estimated) number of elements
4133	>	* needed for this operation to be executed in parallel
4134	>	* @param transformer a function returning the transformation
4135	>	* for an element
4136	>	* @param basis the identity (initial default value) for the reduction
4137	>	* @param reducer a commutative associative combining function
4138	>	* @return the result of accumulating the given transformation
4139	>	* of all entries
4140	>	* @since 1.8
4141	>	*/
4142	>	public double reduceEntriesToDouble(long parallelismThreshold,
4143	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4144	>	double basis,
4145	>	DoubleBinaryOperator reducer) {
4146	>	if (transformer == null || reducer == null)
4147	>	throw new NullPointerException();
4148	>	return new MapReduceEntriesToDoubleTask<K,V>
4149	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4150	>	null, transformer, basis, reducer).invoke();
4151	>	}
4152	>
4153	>	/**
4154	>	* Returns the result of accumulating the given transformation
4155	>	* of all entries using the given reducer to combine values,
4156	>	* and the given basis as an identity value.
4157	>	*
4158	>	* @param parallelismThreshold the (estimated) number of elements
4159	>	* needed for this operation to be executed in parallel
4160	>	* @param transformer a function returning the transformation
4161	>	* for an element
4162	>	* @param basis the identity (initial default value) for the reduction
4163	>	* @param reducer a commutative associative combining function
4164	>	* @return the result of accumulating the given transformation
4165	>	* of all entries
4166	>	* @since 1.8
4167	>	*/
4168	>	public long reduceEntriesToLong(long parallelismThreshold,
4169	>	ToLongFunction<Map.Entry<K,V>> transformer,
4170	>	long basis,
4171	>	LongBinaryOperator reducer) {
4172	>	if (transformer == null || reducer == null)
4173	>	throw new NullPointerException();
4174	>	return new MapReduceEntriesToLongTask<K,V>
4175	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4176	>	null, transformer, basis, reducer).invoke();
4177	>	}
4178	>
4179	>	/**
4180	>	* Returns the result of accumulating the given transformation
4181	>	* of all entries using the given reducer to combine values,
4182	>	* and the given basis as an identity value.
4183	>	*
4184	>	* @param parallelismThreshold the (estimated) number of elements
4185	>	* needed for this operation to be executed in parallel
4186	>	* @param transformer a function returning the transformation
4187	>	* for an element
4188	>	* @param basis the identity (initial default value) for the reduction
4189	>	* @param reducer a commutative associative combining function
4190	>	* @return the result of accumulating the given transformation
4191	>	* of all entries
4192	>	* @since 1.8
4193	>	*/
4194	>	public int reduceEntriesToInt(long parallelismThreshold,
4195	>	ToIntFunction<Map.Entry<K,V>> transformer,
4196	>	int basis,
4197	>	IntBinaryOperator reducer) {
4198	>	if (transformer == null || reducer == null)
4199	>	throw new NullPointerException();
4200	>	return new MapReduceEntriesToIntTask<K,V>
4201	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4202	>	null, transformer, basis, reducer).invoke();
4203	>	}
4204	>
4205	>
4206	>	/* ----------------Views -------------- */
4207	>
4208	>	/**
4209	>	* Base class for views.
4210	>	*/
4211	>	abstract static class CollectionView<K,V,E>
4212	>	implements Collection<E>, java.io.Serializable {
4213	>	private static final long serialVersionUID = 7249069246763182397L;
4214	>	final ConcurrentHashMap<K,V> map;
4215	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4216	>
4217	>	/**
4218	>	* Returns the map backing this view.
4219	>	*
4220	>	* @return the map backing this view
4221	>	*/
4222	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4223	>
4224	>	/**
4225	>	* Removes all of the elements from this view, by removing all
4226	>	* the mappings from the map backing this view.
4227	>	*/
4228	>	public final void clear()      { map.clear(); }
4229	>	public final int size()        { return map.size(); }
4230	>	public final boolean isEmpty() { return map.isEmpty(); }
4231	>
4232	>	// implementations below rely on concrete classes supplying these
4233	>	// abstract methods
4234	>	/**
4235	>	* Returns a "weakly consistent" iterator that will never
4236	>	* throw {@link ConcurrentModificationException}, and
4237	>	* guarantees to traverse elements as they existed upon
4238	>	* construction of the iterator, and may (but is not
4239	>	* guaranteed to) reflect any modifications subsequent to
4240	>	* construction.
4241	>	*/
4242	>	public abstract Iterator<E> iterator();
4243	>	public abstract boolean contains(Object o);
4244	>	public abstract boolean remove(Object o);
4245	>
4246	>	private static final String oomeMsg = "Required array size too large";
4247	>
4248	>	public final Object[] toArray() {
4249	>	long sz = map.mappingCount();
4250	>	if (sz > MAX_ARRAY_SIZE)
4251	>	throw new OutOfMemoryError(oomeMsg);
4252	>	int n = (int)sz;
4253	>	Object[] r = new Object[n];
4254	>	int i = 0;
4255	>	for (E e : this) {
4256	>	if (i == n) {
4257	>	if (n >= MAX_ARRAY_SIZE)
4258	>	throw new OutOfMemoryError(oomeMsg);
4259	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4260	>	n = MAX_ARRAY_SIZE;
4261	>	else
4262	>	n += (n >>> 1) + 1;
4263	>	r = Arrays.copyOf(r, n);
4264	>	}
4265	>	r[i++] = e;
4266	>	}
4267	>	return (i == n) ? r : Arrays.copyOf(r, i);
4268		}
4269	<	public void clear() {
4270	<	ConcurrentHashMap.this.clear();
4269	>
4270	>	@SuppressWarnings("unchecked")
4271	>	public final <T> T[] toArray(T[] a) {
4272	>	long sz = map.mappingCount();
4273	>	if (sz > MAX_ARRAY_SIZE)
4274	>	throw new OutOfMemoryError(oomeMsg);
4275	>	int m = (int)sz;
4276	>	T[] r = (a.length >= m) ? a :
4277	>	(T[])java.lang.reflect.Array
4278	>	.newInstance(a.getClass().getComponentType(), m);
4279	>	int n = r.length;
4280	>	int i = 0;
4281	>	for (E e : this) {
4282	>	if (i == n) {
4283	>	if (n >= MAX_ARRAY_SIZE)
4284	>	throw new OutOfMemoryError(oomeMsg);
4285	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4286	>	n = MAX_ARRAY_SIZE;
4287	>	else
4288	>	n += (n >>> 1) + 1;
4289	>	r = Arrays.copyOf(r, n);
4290	>	}
4291	>	r[i++] = (T)e;
4292	>	}
4293	>	if (a == r && i < n) {
4294	>	r[i] = null; // null-terminate
4295	>	return r;
4296	>	}
4297	>	return (i == n) ? r : Arrays.copyOf(r, i);
4298		}
4299	+
4300	+	/**
4301	+	* Returns a string representation of this collection.
4302	+	* The string representation consists of the string representations
4303	+	* of the collection's elements in the order they are returned by
4304	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4305	+	* Adjacent elements are separated by the characters {@code ", "}
4306	+	* (comma and space).  Elements are converted to strings as by
4307	+	* {@link String#valueOf(Object)}.
4308	+	*
4309	+	* @return a string representation of this collection
4310	+	*/
4311	+	public final String toString() {
4312	+	StringBuilder sb = new StringBuilder();
4313	+	sb.append('[');
4314	+	Iterator<E> it = iterator();
4315	+	if (it.hasNext()) {
4316	+	for (;;) {
4317	+	Object e = it.next();
4318	+	sb.append(e == this ? "(this Collection)" : e);
4319	+	if (!it.hasNext())
4320	+	break;
4321	+	sb.append(',').append(' ');
4322	+	}
4323	+	}
4324	+	return sb.append(']').toString();
4325	+	}
4326	+
4327	+	public final boolean containsAll(Collection<?> c) {
4328	+	if (c != this) {
4329	+	for (Object e : c) {
4330	+	if (e == null || !contains(e))
4331	+	return false;
4332	+	}
4333	+	}
4334	+	return true;
4335	+	}
4336	+
4337	+	public final boolean removeAll(Collection<?> c) {
4338	+	boolean modified = false;
4339	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4340	+	if (c.contains(it.next())) {
4341	+	it.remove();
4342	+	modified = true;
4343	+	}
4344	+	}
4345	+	return modified;
4346	+	}
4347	+
4348	+	public final boolean retainAll(Collection<?> c) {
4349	+	boolean modified = false;
4350	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4351	+	if (!c.contains(it.next())) {
4352	+	it.remove();
4353	+	modified = true;
4354	+	}
4355	+	}
4356	+	return modified;
4357	+	}
4358	+
4359		}
4360
4361	<	final class Values extends AbstractCollection<V> {
4362	<	public Iterator<V> iterator() {
4363	<	return new ValueIterator();
4361	>	/**
4362	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4363	>	* which additions may optionally be enabled by mapping to a
4364	>	* common value.  This class cannot be directly instantiated.
4365	>	* See {@link #keySet() keySet()},
4366	>	* {@link #keySet(Object) keySet(V)},
4367	>	* {@link #newKeySet() newKeySet()},
4368	>	* {@link #newKeySet(int) newKeySet(int)}.
4369	>	*
4370	>	* @since 1.8
4371	>	*/
4372	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4373	>	implements Set<K>, java.io.Serializable {
4374	>	private static final long serialVersionUID = 7249069246763182397L;
4375	>	private final V value;
4376	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4377	>	super(map);
4378	>	this.value = value;
4379		}
4380	<	public int size() {
4381	<	return ConcurrentHashMap.this.size();
4380	>
4381	>	/**
4382	>	* Returns the default mapped value for additions,
4383	>	* or {@code null} if additions are not supported.
4384	>	*
4385	>	* @return the default mapped value for additions, or {@code null}
4386	>	* if not supported
4387	>	*/
4388	>	public V getMappedValue() { return value; }
4389	>
4390	>	/**
4391	>	* {@inheritDoc}
4392	>	* @throws NullPointerException if the specified key is null
4393	>	*/
4394	>	public boolean contains(Object o) { return map.containsKey(o); }
4395	>
4396	>	/**
4397	>	* Removes the key from this map view, by removing the key (and its
4398	>	* corresponding value) from the backing map.  This method does
4399	>	* nothing if the key is not in the map.
4400	>	*
4401	>	* @param  o the key to be removed from the backing map
4402	>	* @return {@code true} if the backing map contained the specified key
4403	>	* @throws NullPointerException if the specified key is null
4404	>	*/
4405	>	public boolean remove(Object o) { return map.remove(o) != null; }
4406	>
4407	>	/**
4408	>	* @return an iterator over the keys of the backing map
4409	>	*/
4410	>	public Iterator<K> iterator() {
4411	>	Node<K,V>[] t;
4412	>	ConcurrentHashMap<K,V> m = map;
4413	>	int f = (t = m.table) == null ? 0 : t.length;
4414	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4415		}
4416	<	public boolean contains(Object o) {
4417	<	return ConcurrentHashMap.this.containsValue(o);
4416	>
4417	>	/**
4418	>	* Adds the specified key to this set view by mapping the key to
4419	>	* the default mapped value in the backing map, if defined.
4420	>	*
4421	>	* @param e key to be added
4422	>	* @return {@code true} if this set changed as a result of the call
4423	>	* @throws NullPointerException if the specified key is null
4424	>	* @throws UnsupportedOperationException if no default mapped value
4425	>	* for additions was provided
4426	>	*/
4427	>	public boolean add(K e) {
4428	>	V v;
4429	>	if ((v = value) == null)
4430	>	throw new UnsupportedOperationException();
4431	>	return map.putVal(e, v, true) == null;
4432		}
4433	<	public void clear() {
4434	<	ConcurrentHashMap.this.clear();
4433	>
4434	>	/**
4435	>	* Adds all of the elements in the specified collection to this set,
4436	>	* as if by calling {@link #add} on each one.
4437	>	*
4438	>	* @param c the elements to be inserted into this set
4439	>	* @return {@code true} if this set changed as a result of the call
4440	>	* @throws NullPointerException if the collection or any of its
4441	>	* elements are {@code null}
4442	>	* @throws UnsupportedOperationException if no default mapped value
4443	>	* for additions was provided
4444	>	*/
4445	>	public boolean addAll(Collection<? extends K> c) {
4446	>	boolean added = false;
4447	>	V v;
4448	>	if ((v = value) == null)
4449	>	throw new UnsupportedOperationException();
4450	>	for (K e : c) {
4451	>	if (map.putVal(e, v, true) == null)
4452	>	added = true;
4453	>	}
4454	>	return added;
4455	>	}
4456	>
4457	>	public int hashCode() {
4458	>	int h = 0;
4459	>	for (K e : this)
4460	>	h += e.hashCode();
4461	>	return h;
4462	>	}
4463	>
4464	>	public boolean equals(Object o) {
4465	>	Set<?> c;
4466	>	return ((o instanceof Set) &&
4467	>	((c = (Set<?>)o) == this ||
4468	>	(containsAll(c) && c.containsAll(this))));
4469	>	}
4470	>
4471	>	public Spliterator<K> spliterator() {
4472	>	Node<K,V>[] t;
4473	>	ConcurrentHashMap<K,V> m = map;
4474	>	long n = m.sumCount();
4475	>	int f = (t = m.table) == null ? 0 : t.length;
4476	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4477	>	}
4478	>
4479	>	public void forEach(Consumer<? super K> action) {
4480	>	if (action == null) throw new NullPointerException();
4481	>	Node<K,V>[] t;
4482	>	if ((t = map.table) != null) {
4483	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4484	>	for (Node<K,V> p; (p = it.advance()) != null; )
4485	>	action.accept(p.key);
4486	>	}
4487		}
4488		}
4489
4490	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4491	<	public Iterator<Map.Entry<K,V>> iterator() {
4492	<	return new EntryIterator();
4490	>	/**
4491	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4492	>	* values, in which additions are disabled. This class cannot be
4493	>	* directly instantiated. See {@link #values()}.
4494	>	*/
4495	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4496	>	implements Collection<V>, java.io.Serializable {
4497	>	private static final long serialVersionUID = 2249069246763182397L;
4498	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4499	>	public final boolean contains(Object o) {
4500	>	return map.containsValue(o);
4501		}
4502	+
4503	+	public final boolean remove(Object o) {
4504	+	if (o != null) {
4505	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4506	+	if (o.equals(it.next())) {
4507	+	it.remove();
4508	+	return true;
4509	+	}
4510	+	}
4511	+	}
4512	+	return false;
4513	+	}
4514	+
4515	+	public final Iterator<V> iterator() {
4516	+	ConcurrentHashMap<K,V> m = map;
4517	+	Node<K,V>[] t;
4518	+	int f = (t = m.table) == null ? 0 : t.length;
4519	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4520	+	}
4521	+
4522	+	public final boolean add(V e) {
4523	+	throw new UnsupportedOperationException();
4524	+	}
4525	+	public final boolean addAll(Collection<? extends V> c) {
4526	+	throw new UnsupportedOperationException();
4527	+	}
4528	+
4529	+	public Spliterator<V> spliterator() {
4530	+	Node<K,V>[] t;
4531	+	ConcurrentHashMap<K,V> m = map;
4532	+	long n = m.sumCount();
4533	+	int f = (t = m.table) == null ? 0 : t.length;
4534	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4535	+	}
4536	+
4537	+	public void forEach(Consumer<? super V> action) {
4538	+	if (action == null) throw new NullPointerException();
4539	+	Node<K,V>[] t;
4540	+	if ((t = map.table) != null) {
4541	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4542	+	for (Node<K,V> p; (p = it.advance()) != null; )
4543	+	action.accept(p.val);
4544	+	}
4545	+	}
4546	+	}
4547	+
4548	+	/**
4549	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4550	+	* entries.  This class cannot be directly instantiated. See
4551	+	* {@link #entrySet()}.
4552	+	*/
4553	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4554	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4555	+	private static final long serialVersionUID = 2249069246763182397L;
4556	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4557	+
4558		public boolean contains(Object o) {
4559	<	if (!(o instanceof Map.Entry))
4560	<	return false;
4561	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4562	<	V v = ConcurrentHashMap.this.get(e.getKey());
4563	<	return v != null && v.equals(e.getValue());
4559	>	Object k, v, r; Map.Entry<?,?> e;
4560	>	return ((o instanceof Map.Entry) &&
4561	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4562	>	(r = map.get(k)) != null &&
4563	>	(v = e.getValue()) != null &&
4564	>	(v == r || v.equals(r)));
4565		}
4566	+
4567		public boolean remove(Object o) {
4568	<	if (!(o instanceof Map.Entry))
4569	<	return false;
4570	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4571	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4568	>	Object k, v; Map.Entry<?,?> e;
4569	>	return ((o instanceof Map.Entry) &&
4570	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4571	>	(v = e.getValue()) != null &&
4572	>	map.remove(k, v));
4573		}
4574	<	public int size() {
4575	<	return ConcurrentHashMap.this.size();
4574	>
4575	>	/**
4576	>	* @return an iterator over the entries of the backing map
4577	>	*/
4578	>	public Iterator<Map.Entry<K,V>> iterator() {
4579	>	ConcurrentHashMap<K,V> m = map;
4580	>	Node<K,V>[] t;
4581	>	int f = (t = m.table) == null ? 0 : t.length;
4582	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4583		}
4584	<	public void clear() {
4585	<	ConcurrentHashMap.this.clear();
4584	>
4585	>	public boolean add(Entry<K,V> e) {
4586	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4587		}
4588	+
4589	+	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4590	+	boolean added = false;
4591	+	for (Entry<K,V> e : c) {
4592	+	if (add(e))
4593	+	added = true;
4594	+	}
4595	+	return added;
4596	+	}
4597	+
4598	+	public final int hashCode() {
4599	+	int h = 0;
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	+	h += p.hashCode();
4605	+	}
4606	+	}
4607	+	return h;
4608	+	}
4609	+
4610	+	public final boolean equals(Object o) {
4611	+	Set<?> c;
4612	+	return ((o instanceof Set) &&
4613	+	((c = (Set<?>)o) == this ||
4614	+	(containsAll(c) && c.containsAll(this))));
4615	+	}
4616	+
4617	+	public Spliterator<Map.Entry<K,V>> spliterator() {
4618	+	Node<K,V>[] t;
4619	+	ConcurrentHashMap<K,V> m = map;
4620	+	long n = m.sumCount();
4621	+	int f = (t = m.table) == null ? 0 : t.length;
4622	+	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4623	+	}
4624	+
4625	+	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4626	+	if (action == null) throw new NullPointerException();
4627	+	Node<K,V>[] t;
4628	+	if ((t = map.table) != null) {
4629	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4630	+	for (Node<K,V> p; (p = it.advance()) != null; )
4631	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4632	+	}
4633	+	}
4634	+
4635		}
4636
4637	<	/* ---------------- Serialization Support -------------- */
4637	>	// -------------------------------------------------------
4638
4639		/**
4640	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
4641	<	* stream (i.e., serialize it).
1229	<	* @param s the stream
1230	<	* @serialData
1231	<	* the key (Object) and value (Object)
1232	<	* for each key-value mapping, followed by a null pair.
1233	<	* The key-value mappings are emitted in no particular order.
4640	>	* Base class for bulk tasks. Repeats some fields and code from
4641	>	* class Traverser, because we need to subclass CountedCompleter.
4642		*/
4643	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4644	<	s.defaultWriteObject();
4643	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4644	>	Node<K,V>[] tab;        // same as Traverser
4645	>	Node<K,V> next;
4646	>	int index;
4647	>	int baseIndex;
4648	>	int baseLimit;
4649	>	final int baseSize;
4650	>	int batch;              // split control
4651	>
4652	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4653	>	super(par);
4654	>	this.batch = b;
4655	>	this.index = this.baseIndex = i;
4656	>	if ((this.tab = t) == null)
4657	>	this.baseSize = this.baseLimit = 0;
4658	>	else if (par == null)
4659	>	this.baseSize = this.baseLimit = t.length;
4660	>	else {
4661	>	this.baseLimit = f;
4662	>	this.baseSize = par.baseSize;
4663	>	}
4664	>	}
4665
4666	<	for (int k = 0; k < segments.length; ++k) {
4667	<	Segment<K,V> seg = segments[k];
4668	<	seg.lock();
4669	<	try {
4670	<	HashEntry<K,V>[] tab = seg.table;
4671	<	for (int i = 0; i < tab.length; ++i) {
4672	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
4673	<	s.writeObject(e.key);
4674	<	s.writeObject(e.value);
4666	>	/**
4667	>	* Same as Traverser version
4668	>	*/
4669	>	final Node<K,V> advance() {
4670	>	Node<K,V> e;
4671	>	if ((e = next) != null)
4672	>	e = e.next;
4673	>	for (;;) {
4674	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4675	>	if (e != null)
4676	>	return next = e;
4677	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4678	>	(n = t.length) <= (i = index) || i < 0)
4679	>	return next = null;
4680	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4681	>	if (e instanceof ForwardingNode) {
4682	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4683	>	e = null;
4684	>	continue;
4685		}
4686	+	else if (e instanceof TreeBin)
4687	+	e = ((TreeBin<K,V>)e).first;
4688	+	else
4689	+	e = null;
4690		}
4691	<	} finally {
4692	<	seg.unlock();
4691	>	if ((index += baseSize) >= n)
4692	>	index = ++baseIndex;    // visit upper slots if present
4693		}
4694		}
1253	–	s.writeObject(null);
1254	–	s.writeObject(null);
4695		}
4696
4697	<	/**
4698	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
4699	<	* stream (i.e., deserialize it).
4700	<	* @param s the stream
4701	<	*/
4702	<	private void readObject(java.io.ObjectInputStream s)
4703	<	throws IOException, ClassNotFoundException  {
4704	<	s.defaultReadObject();
4697	>	/*
4698	>	* Task classes. Coded in a regular but ugly format/style to
4699	>	* simplify checks that each variant differs in the right way from
4700	>	* others. The null screenings exist because compilers cannot tell
4701	>	* that we've already null-checked task arguments, so we force
4702	>	* simplest hoisted bypass to help avoid convoluted traps.
4703	>	*/
4704	>	@SuppressWarnings("serial")
4705	>	static final class ForEachKeyTask<K,V>
4706	>	extends BulkTask<K,V,Void> {
4707	>	final Consumer<? super K> action;
4708	>	ForEachKeyTask
4709	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4710	>	Consumer<? super K> action) {
4711	>	super(p, b, i, f, t);
4712	>	this.action = action;
4713	>	}
4714	>	public final void compute() {
4715	>	final Consumer<? super K> 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 ForEachKeyTask<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.key);
4726	>	propagateCompletion();
4727	>	}
4728	>	}
4729	>	}
4730
4731	<	// Initialize each segment to be minimally sized, and let grow.
4732	<	for (int i = 0; i < segments.length; ++i) {
4733	<	segments[i].setTable(new HashEntry[1]);
4731	>	@SuppressWarnings("serial")
4732	>	static final class ForEachValueTask<K,V>
4733	>	extends BulkTask<K,V,Void> {
4734	>	final Consumer<? super V> action;
4735	>	ForEachValueTask
4736	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4737	>	Consumer<? super V> action) {
4738	>	super(p, b, i, f, t);
4739	>	this.action = action;
4740	>	}
4741	>	public final void compute() {
4742	>	final Consumer<? super 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 ForEachValueTask<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.val);
4753	>	propagateCompletion();
4754	>	}
4755		}
4756	+	}
4757
4758	<	// Read the keys and values, and put the mappings in the table
4759	<	for (;;) {
4760	<	K key = (K) s.readObject();
4761	<	V value = (V) s.readObject();
4762	<	if (key == null)
4763	<	break;
4764	<	put(key, value);
4758	>	@SuppressWarnings("serial")
4759	>	static final class ForEachEntryTask<K,V>
4760	>	extends BulkTask<K,V,Void> {
4761	>	final Consumer<? super Entry<K,V>> action;
4762	>	ForEachEntryTask
4763	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4764	>	Consumer<? super Entry<K,V>> action) {
4765	>	super(p, b, i, f, t);
4766	>	this.action = action;
4767	>	}
4768	>	public final void compute() {
4769	>	final Consumer<? super Entry<K,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 ForEachEntryTask<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);
4780	>	propagateCompletion();
4781	>	}
4782	>	}
4783	>	}
4784	>
4785	>	@SuppressWarnings("serial")
4786	>	static final class ForEachMappingTask<K,V>
4787	>	extends BulkTask<K,V,Void> {
4788	>	final BiConsumer<? super K, ? super V> action;
4789	>	ForEachMappingTask
4790	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4791	>	BiConsumer<? super K,? super V> action) {
4792	>	super(p, b, i, f, t);
4793	>	this.action = action;
4794	>	}
4795	>	public final void compute() {
4796	>	final BiConsumer<? super K, ? super V> action;
4797	>	if ((action = this.action) != null) {
4798	>	for (int i = baseIndex, f, h; batch > 0 &&
4799	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4800	>	addToPendingCount(1);
4801	>	new ForEachMappingTask<K,V>
4802	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4803	>	action).fork();
4804	>	}
4805	>	for (Node<K,V> p; (p = advance()) != null; )
4806	>	action.accept(p.key, p.val);
4807	>	propagateCompletion();
4808	>	}
4809	>	}
4810	>	}
4811	>
4812	>	@SuppressWarnings("serial")
4813	>	static final class ForEachTransformedKeyTask<K,V,U>
4814	>	extends BulkTask<K,V,Void> {
4815	>	final Function<? super K, ? extends U> transformer;
4816	>	final Consumer<? super U> action;
4817	>	ForEachTransformedKeyTask
4818	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4819	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4820	>	super(p, b, i, f, t);
4821	>	this.transformer = transformer; this.action = action;
4822	>	}
4823	>	public final void compute() {
4824	>	final Function<? super K, ? extends U> transformer;
4825	>	final Consumer<? super U> action;
4826	>	if ((transformer = this.transformer) != null &&
4827	>	(action = this.action) != null) {
4828	>	for (int i = baseIndex, f, h; batch > 0 &&
4829	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4830	>	addToPendingCount(1);
4831	>	new ForEachTransformedKeyTask<K,V,U>
4832	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4833	>	transformer, action).fork();
4834	>	}
4835	>	for (Node<K,V> p; (p = advance()) != null; ) {
4836	>	U u;
4837	>	if ((u = transformer.apply(p.key)) != null)
4838	>	action.accept(u);
4839	>	}
4840	>	propagateCompletion();
4841	>	}
4842	>	}
4843	>	}
4844	>
4845	>	@SuppressWarnings("serial")
4846	>	static final class ForEachTransformedValueTask<K,V,U>
4847	>	extends BulkTask<K,V,Void> {
4848	>	final Function<? super V, ? extends U> transformer;
4849	>	final Consumer<? super U> action;
4850	>	ForEachTransformedValueTask
4851	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4852	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4853	>	super(p, b, i, f, t);
4854	>	this.transformer = transformer; this.action = action;
4855	>	}
4856	>	public final void compute() {
4857	>	final Function<? super V, ? extends U> transformer;
4858	>	final Consumer<? super U> action;
4859	>	if ((transformer = this.transformer) != null &&
4860	>	(action = this.action) != null) {
4861	>	for (int i = baseIndex, f, h; batch > 0 &&
4862	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4863	>	addToPendingCount(1);
4864	>	new ForEachTransformedValueTask<K,V,U>
4865	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4866	>	transformer, action).fork();
4867	>	}
4868	>	for (Node<K,V> p; (p = advance()) != null; ) {
4869	>	U u;
4870	>	if ((u = transformer.apply(p.val)) != null)
4871	>	action.accept(u);
4872	>	}
4873	>	propagateCompletion();
4874	>	}
4875	>	}
4876	>	}
4877	>
4878	>	@SuppressWarnings("serial")
4879	>	static final class ForEachTransformedEntryTask<K,V,U>
4880	>	extends BulkTask<K,V,Void> {
4881	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4882	>	final Consumer<? super U> action;
4883	>	ForEachTransformedEntryTask
4884	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4885	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4886	>	super(p, b, i, f, t);
4887	>	this.transformer = transformer; this.action = action;
4888	>	}
4889	>	public final void compute() {
4890	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4891	>	final Consumer<? super U> action;
4892	>	if ((transformer = this.transformer) != null &&
4893	>	(action = this.action) != null) {
4894	>	for (int i = baseIndex, f, h; batch > 0 &&
4895	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4896	>	addToPendingCount(1);
4897	>	new ForEachTransformedEntryTask<K,V,U>
4898	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4899	>	transformer, action).fork();
4900	>	}
4901	>	for (Node<K,V> p; (p = advance()) != null; ) {
4902	>	U u;
4903	>	if ((u = transformer.apply(p)) != null)
4904	>	action.accept(u);
4905	>	}
4906	>	propagateCompletion();
4907	>	}
4908	>	}
4909	>	}
4910	>
4911	>	@SuppressWarnings("serial")
4912	>	static final class ForEachTransformedMappingTask<K,V,U>
4913	>	extends BulkTask<K,V,Void> {
4914	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4915	>	final Consumer<? super U> action;
4916	>	ForEachTransformedMappingTask
4917	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4918	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4919	>	Consumer<? super U> action) {
4920	>	super(p, b, i, f, t);
4921	>	this.transformer = transformer; this.action = action;
4922	>	}
4923	>	public final void compute() {
4924	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4925	>	final Consumer<? super U> action;
4926	>	if ((transformer = this.transformer) != null &&
4927	>	(action = this.action) != null) {
4928	>	for (int i = baseIndex, f, h; batch > 0 &&
4929	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4930	>	addToPendingCount(1);
4931	>	new ForEachTransformedMappingTask<K,V,U>
4932	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4933	>	transformer, action).fork();
4934	>	}
4935	>	for (Node<K,V> p; (p = advance()) != null; ) {
4936	>	U u;
4937	>	if ((u = transformer.apply(p.key, p.val)) != null)
4938	>	action.accept(u);
4939	>	}
4940	>	propagateCompletion();
4941	>	}
4942	>	}
4943	>	}
4944	>
4945	>	@SuppressWarnings("serial")
4946	>	static final class SearchKeysTask<K,V,U>
4947	>	extends BulkTask<K,V,U> {
4948	>	final Function<? super K, ? extends U> searchFunction;
4949	>	final AtomicReference<U> result;
4950	>	SearchKeysTask
4951	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4952	>	Function<? super K, ? extends U> searchFunction,
4953	>	AtomicReference<U> result) {
4954	>	super(p, b, i, f, t);
4955	>	this.searchFunction = searchFunction; this.result = result;
4956	>	}
4957	>	public final U getRawResult() { return result.get(); }
4958	>	public final void compute() {
4959	>	final Function<? super K, ? extends U> searchFunction;
4960	>	final AtomicReference<U> result;
4961	>	if ((searchFunction = this.searchFunction) != null &&
4962	>	(result = this.result) != null) {
4963	>	for (int i = baseIndex, f, h; batch > 0 &&
4964	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4965	>	if (result.get() != null)
4966	>	return;
4967	>	addToPendingCount(1);
4968	>	new SearchKeysTask<K,V,U>
4969	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4970	>	searchFunction, result).fork();
4971	>	}
4972	>	while (result.get() == null) {
4973	>	U u;
4974	>	Node<K,V> p;
4975	>	if ((p = advance()) == null) {
4976	>	propagateCompletion();
4977	>	break;
4978	>	}
4979	>	if ((u = searchFunction.apply(p.key)) != null) {
4980	>	if (result.compareAndSet(null, u))
4981	>	quietlyCompleteRoot();
4982	>	break;
4983	>	}
4984	>	}
4985	>	}
4986	>	}
4987	>	}
4988	>
4989	>	@SuppressWarnings("serial")
4990	>	static final class SearchValuesTask<K,V,U>
4991	>	extends BulkTask<K,V,U> {
4992	>	final Function<? super V, ? extends U> searchFunction;
4993	>	final AtomicReference<U> result;
4994	>	SearchValuesTask
4995	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4996	>	Function<? super V, ? extends U> searchFunction,
4997	>	AtomicReference<U> result) {
4998	>	super(p, b, i, f, t);
4999	>	this.searchFunction = searchFunction; this.result = result;
5000	>	}
5001	>	public final U getRawResult() { return result.get(); }
5002	>	public final void compute() {
5003	>	final Function<? super V, ? extends U> searchFunction;
5004	>	final AtomicReference<U> result;
5005	>	if ((searchFunction = this.searchFunction) != null &&
5006	>	(result = this.result) != null) {
5007	>	for (int i = baseIndex, f, h; batch > 0 &&
5008	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5009	>	if (result.get() != null)
5010	>	return;
5011	>	addToPendingCount(1);
5012	>	new SearchValuesTask<K,V,U>
5013	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5014	>	searchFunction, result).fork();
5015	>	}
5016	>	while (result.get() == null) {
5017	>	U u;
5018	>	Node<K,V> p;
5019	>	if ((p = advance()) == null) {
5020	>	propagateCompletion();
5021	>	break;
5022	>	}
5023	>	if ((u = searchFunction.apply(p.val)) != null) {
5024	>	if (result.compareAndSet(null, u))
5025	>	quietlyCompleteRoot();
5026	>	break;
5027	>	}
5028	>	}
5029	>	}
5030	>	}
5031	>	}
5032	>
5033	>	@SuppressWarnings("serial")
5034	>	static final class SearchEntriesTask<K,V,U>
5035	>	extends BulkTask<K,V,U> {
5036	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5037	>	final AtomicReference<U> result;
5038	>	SearchEntriesTask
5039	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5040	>	Function<Entry<K,V>, ? extends U> searchFunction,
5041	>	AtomicReference<U> result) {
5042	>	super(p, b, i, f, t);
5043	>	this.searchFunction = searchFunction; this.result = result;
5044	>	}
5045	>	public final U getRawResult() { return result.get(); }
5046	>	public final void compute() {
5047	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5048	>	final AtomicReference<U> result;
5049	>	if ((searchFunction = this.searchFunction) != null &&
5050	>	(result = this.result) != null) {
5051	>	for (int i = baseIndex, f, h; batch > 0 &&
5052	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5053	>	if (result.get() != null)
5054	>	return;
5055	>	addToPendingCount(1);
5056	>	new SearchEntriesTask<K,V,U>
5057	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5058	>	searchFunction, result).fork();
5059	>	}
5060	>	while (result.get() == null) {
5061	>	U u;
5062	>	Node<K,V> p;
5063	>	if ((p = advance()) == null) {
5064	>	propagateCompletion();
5065	>	break;
5066	>	}
5067	>	if ((u = searchFunction.apply(p)) != null) {
5068	>	if (result.compareAndSet(null, u))
5069	>	quietlyCompleteRoot();
5070	>	return;
5071	>	}
5072	>	}
5073	>	}
5074	>	}
5075	>	}
5076	>
5077	>	@SuppressWarnings("serial")
5078	>	static final class SearchMappingsTask<K,V,U>
5079	>	extends BulkTask<K,V,U> {
5080	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5081	>	final AtomicReference<U> result;
5082	>	SearchMappingsTask
5083	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5084	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5085	>	AtomicReference<U> result) {
5086	>	super(p, b, i, f, t);
5087	>	this.searchFunction = searchFunction; this.result = result;
5088	>	}
5089	>	public final U getRawResult() { return result.get(); }
5090	>	public final void compute() {
5091	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5092	>	final AtomicReference<U> result;
5093	>	if ((searchFunction = this.searchFunction) != null &&
5094	>	(result = this.result) != null) {
5095	>	for (int i = baseIndex, f, h; batch > 0 &&
5096	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5097	>	if (result.get() != null)
5098	>	return;
5099	>	addToPendingCount(1);
5100	>	new SearchMappingsTask<K,V,U>
5101	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5102	>	searchFunction, result).fork();
5103	>	}
5104	>	while (result.get() == null) {
5105	>	U u;
5106	>	Node<K,V> p;
5107	>	if ((p = advance()) == null) {
5108	>	propagateCompletion();
5109	>	break;
5110	>	}
5111	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5112	>	if (result.compareAndSet(null, u))
5113	>	quietlyCompleteRoot();
5114	>	break;
5115	>	}
5116	>	}
5117	>	}
5118	>	}
5119	>	}
5120	>
5121	>	@SuppressWarnings("serial")
5122	>	static final class ReduceKeysTask<K,V>
5123	>	extends BulkTask<K,V,K> {
5124	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5125	>	K result;
5126	>	ReduceKeysTask<K,V> rights, nextRight;
5127	>	ReduceKeysTask
5128	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5129	>	ReduceKeysTask<K,V> nextRight,
5130	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5131	>	super(p, b, i, f, t); this.nextRight = nextRight;
5132	>	this.reducer = reducer;
5133	>	}
5134	>	public final K getRawResult() { return result; }
5135	>	public final void compute() {
5136	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5137	>	if ((reducer = this.reducer) != null) {
5138	>	for (int i = baseIndex, f, h; batch > 0 &&
5139	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5140	>	addToPendingCount(1);
5141	>	(rights = new ReduceKeysTask<K,V>
5142	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5143	>	rights, reducer)).fork();
5144	>	}
5145	>	K r = null;
5146	>	for (Node<K,V> p; (p = advance()) != null; ) {
5147	>	K u = p.key;
5148	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5149	>	}
5150	>	result = r;
5151	>	CountedCompleter<?> c;
5152	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5153	>	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5154	>	t = (ReduceKeysTask<K,V>)c,
5155	>	s = t.rights;
5156	>	while (s != null) {
5157	>	K tr, sr;
5158	>	if ((sr = s.result) != null)
5159	>	t.result = (((tr = t.result) == null) ? sr :
5160	>	reducer.apply(tr, sr));
5161	>	s = t.rights = s.nextRight;
5162	>	}
5163	>	}
5164	>	}
5165	>	}
5166	>	}
5167	>
5168	>	@SuppressWarnings("serial")
5169	>	static final class ReduceValuesTask<K,V>
5170	>	extends BulkTask<K,V,V> {
5171	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5172	>	V result;
5173	>	ReduceValuesTask<K,V> rights, nextRight;
5174	>	ReduceValuesTask
5175	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5176	>	ReduceValuesTask<K,V> nextRight,
5177	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5178	>	super(p, b, i, f, t); this.nextRight = nextRight;
5179	>	this.reducer = reducer;
5180	>	}
5181	>	public final V getRawResult() { return result; }
5182	>	public final void compute() {
5183	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5184	>	if ((reducer = this.reducer) != null) {
5185	>	for (int i = baseIndex, f, h; batch > 0 &&
5186	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5187	>	addToPendingCount(1);
5188	>	(rights = new ReduceValuesTask<K,V>
5189	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5190	>	rights, reducer)).fork();
5191	>	}
5192	>	V r = null;
5193	>	for (Node<K,V> p; (p = advance()) != null; ) {
5194	>	V v = p.val;
5195	>	r = (r == null) ? v : reducer.apply(r, v);
5196	>	}
5197	>	result = r;
5198	>	CountedCompleter<?> c;
5199	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5200	>	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5201	>	t = (ReduceValuesTask<K,V>)c,
5202	>	s = t.rights;
5203	>	while (s != null) {
5204	>	V tr, sr;
5205	>	if ((sr = s.result) != null)
5206	>	t.result = (((tr = t.result) == null) ? sr :
5207	>	reducer.apply(tr, sr));
5208	>	s = t.rights = s.nextRight;
5209	>	}
5210	>	}
5211	>	}
5212	>	}
5213	>	}
5214	>
5215	>	@SuppressWarnings("serial")
5216	>	static final class ReduceEntriesTask<K,V>
5217	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5218	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5219	>	Map.Entry<K,V> result;
5220	>	ReduceEntriesTask<K,V> rights, nextRight;
5221	>	ReduceEntriesTask
5222	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5223	>	ReduceEntriesTask<K,V> nextRight,
5224	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5225	>	super(p, b, i, f, t); this.nextRight = nextRight;
5226	>	this.reducer = reducer;
5227	>	}
5228	>	public final Map.Entry<K,V> getRawResult() { return result; }
5229	>	public final void compute() {
5230	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5231	>	if ((reducer = this.reducer) != null) {
5232	>	for (int i = baseIndex, f, h; batch > 0 &&
5233	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5234	>	addToPendingCount(1);
5235	>	(rights = new ReduceEntriesTask<K,V>
5236	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5237	>	rights, reducer)).fork();
5238	>	}
5239	>	Map.Entry<K,V> r = null;
5240	>	for (Node<K,V> p; (p = advance()) != null; )
5241	>	r = (r == null) ? p : reducer.apply(r, p);
5242	>	result = r;
5243	>	CountedCompleter<?> c;
5244	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5245	>	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5246	>	t = (ReduceEntriesTask<K,V>)c,
5247	>	s = t.rights;
5248	>	while (s != null) {
5249	>	Map.Entry<K,V> tr, sr;
5250	>	if ((sr = s.result) != null)
5251	>	t.result = (((tr = t.result) == null) ? sr :
5252	>	reducer.apply(tr, sr));
5253	>	s = t.rights = s.nextRight;
5254	>	}
5255	>	}
5256	>	}
5257	>	}
5258	>	}
5259	>
5260	>	@SuppressWarnings("serial")
5261	>	static final class MapReduceKeysTask<K,V,U>
5262	>	extends BulkTask<K,V,U> {
5263	>	final Function<? super K, ? extends U> transformer;
5264	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5265	>	U result;
5266	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5267	>	MapReduceKeysTask
5268	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5269	>	MapReduceKeysTask<K,V,U> nextRight,
5270	>	Function<? super K, ? extends U> transformer,
5271	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5272	>	super(p, b, i, f, t); this.nextRight = nextRight;
5273	>	this.transformer = transformer;
5274	>	this.reducer = reducer;
5275	>	}
5276	>	public final U getRawResult() { return result; }
5277	>	public final void compute() {
5278	>	final Function<? super K, ? extends U> transformer;
5279	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5280	>	if ((transformer = this.transformer) != null &&
5281	>	(reducer = this.reducer) != null) {
5282	>	for (int i = baseIndex, f, h; batch > 0 &&
5283	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5284	>	addToPendingCount(1);
5285	>	(rights = new MapReduceKeysTask<K,V,U>
5286	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5287	>	rights, transformer, reducer)).fork();
5288	>	}
5289	>	U r = null;
5290	>	for (Node<K,V> p; (p = advance()) != null; ) {
5291	>	U u;
5292	>	if ((u = transformer.apply(p.key)) != null)
5293	>	r = (r == null) ? u : reducer.apply(r, u);
5294	>	}
5295	>	result = r;
5296	>	CountedCompleter<?> c;
5297	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5298	>	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5299	>	t = (MapReduceKeysTask<K,V,U>)c,
5300	>	s = t.rights;
5301	>	while (s != null) {
5302	>	U tr, sr;
5303	>	if ((sr = s.result) != null)
5304	>	t.result = (((tr = t.result) == null) ? sr :
5305	>	reducer.apply(tr, sr));
5306	>	s = t.rights = s.nextRight;
5307	>	}
5308	>	}
5309	>	}
5310	>	}
5311	>	}
5312	>
5313	>	@SuppressWarnings("serial")
5314	>	static final class MapReduceValuesTask<K,V,U>
5315	>	extends BulkTask<K,V,U> {
5316	>	final Function<? super V, ? extends U> transformer;
5317	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5318	>	U result;
5319	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5320	>	MapReduceValuesTask
5321	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5322	>	MapReduceValuesTask<K,V,U> nextRight,
5323	>	Function<? super V, ? extends U> transformer,
5324	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5325	>	super(p, b, i, f, t); this.nextRight = nextRight;
5326	>	this.transformer = transformer;
5327	>	this.reducer = reducer;
5328	>	}
5329	>	public final U getRawResult() { return result; }
5330	>	public final void compute() {
5331	>	final Function<? super V, ? extends U> transformer;
5332	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5333	>	if ((transformer = this.transformer) != null &&
5334	>	(reducer = this.reducer) != null) {
5335	>	for (int i = baseIndex, f, h; batch > 0 &&
5336	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5337	>	addToPendingCount(1);
5338	>	(rights = new MapReduceValuesTask<K,V,U>
5339	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5340	>	rights, transformer, reducer)).fork();
5341	>	}
5342	>	U r = null;
5343	>	for (Node<K,V> p; (p = advance()) != null; ) {
5344	>	U u;
5345	>	if ((u = transformer.apply(p.val)) != null)
5346	>	r = (r == null) ? u : reducer.apply(r, u);
5347	>	}
5348	>	result = r;
5349	>	CountedCompleter<?> c;
5350	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5351	>	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5352	>	t = (MapReduceValuesTask<K,V,U>)c,
5353	>	s = t.rights;
5354	>	while (s != null) {
5355	>	U tr, sr;
5356	>	if ((sr = s.result) != null)
5357	>	t.result = (((tr = t.result) == null) ? sr :
5358	>	reducer.apply(tr, sr));
5359	>	s = t.rights = s.nextRight;
5360	>	}
5361	>	}
5362	>	}
5363	>	}
5364	>	}
5365	>
5366	>	@SuppressWarnings("serial")
5367	>	static final class MapReduceEntriesTask<K,V,U>
5368	>	extends BulkTask<K,V,U> {
5369	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5370	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5371	>	U result;
5372	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5373	>	MapReduceEntriesTask
5374	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5375	>	MapReduceEntriesTask<K,V,U> nextRight,
5376	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5377	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5378	>	super(p, b, i, f, t); this.nextRight = nextRight;
5379	>	this.transformer = transformer;
5380	>	this.reducer = reducer;
5381	>	}
5382	>	public final U getRawResult() { return result; }
5383	>	public final void compute() {
5384	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5385	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5386	>	if ((transformer = this.transformer) != null &&
5387	>	(reducer = this.reducer) != null) {
5388	>	for (int i = baseIndex, f, h; batch > 0 &&
5389	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5390	>	addToPendingCount(1);
5391	>	(rights = new MapReduceEntriesTask<K,V,U>
5392	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5393	>	rights, transformer, reducer)).fork();
5394	>	}
5395	>	U r = null;
5396	>	for (Node<K,V> p; (p = advance()) != null; ) {
5397	>	U u;
5398	>	if ((u = transformer.apply(p)) != null)
5399	>	r = (r == null) ? u : reducer.apply(r, u);
5400	>	}
5401	>	result = r;
5402	>	CountedCompleter<?> c;
5403	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5404	>	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5405	>	t = (MapReduceEntriesTask<K,V,U>)c,
5406	>	s = t.rights;
5407	>	while (s != null) {
5408	>	U tr, sr;
5409	>	if ((sr = s.result) != null)
5410	>	t.result = (((tr = t.result) == null) ? sr :
5411	>	reducer.apply(tr, sr));
5412	>	s = t.rights = s.nextRight;
5413	>	}
5414	>	}
5415	>	}
5416	>	}
5417	>	}
5418	>
5419	>	@SuppressWarnings("serial")
5420	>	static final class MapReduceMappingsTask<K,V,U>
5421	>	extends BulkTask<K,V,U> {
5422	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5423	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5424	>	U result;
5425	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5426	>	MapReduceMappingsTask
5427	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5428	>	MapReduceMappingsTask<K,V,U> nextRight,
5429	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5430	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5431	>	super(p, b, i, f, t); this.nextRight = nextRight;
5432	>	this.transformer = transformer;
5433	>	this.reducer = reducer;
5434	>	}
5435	>	public final U getRawResult() { return result; }
5436	>	public final void compute() {
5437	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5438	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5439	>	if ((transformer = this.transformer) != null &&
5440	>	(reducer = this.reducer) != null) {
5441	>	for (int i = baseIndex, f, h; batch > 0 &&
5442	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5443	>	addToPendingCount(1);
5444	>	(rights = new MapReduceMappingsTask<K,V,U>
5445	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5446	>	rights, transformer, reducer)).fork();
5447	>	}
5448	>	U r = null;
5449	>	for (Node<K,V> p; (p = advance()) != null; ) {
5450	>	U u;
5451	>	if ((u = transformer.apply(p.key, p.val)) != null)
5452	>	r = (r == null) ? u : reducer.apply(r, u);
5453	>	}
5454	>	result = r;
5455	>	CountedCompleter<?> c;
5456	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5457	>	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5458	>	t = (MapReduceMappingsTask<K,V,U>)c,
5459	>	s = t.rights;
5460	>	while (s != null) {
5461	>	U tr, sr;
5462	>	if ((sr = s.result) != null)
5463	>	t.result = (((tr = t.result) == null) ? sr :
5464	>	reducer.apply(tr, sr));
5465	>	s = t.rights = s.nextRight;
5466	>	}
5467	>	}
5468	>	}
5469	>	}
5470	>	}
5471	>
5472	>	@SuppressWarnings("serial")
5473	>	static final class MapReduceKeysToDoubleTask<K,V>
5474	>	extends BulkTask<K,V,Double> {
5475	>	final ToDoubleFunction<? super K> transformer;
5476	>	final DoubleBinaryOperator reducer;
5477	>	final double basis;
5478	>	double result;
5479	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5480	>	MapReduceKeysToDoubleTask
5481	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5482	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5483	>	ToDoubleFunction<? super K> transformer,
5484	>	double basis,
5485	>	DoubleBinaryOperator reducer) {
5486	>	super(p, b, i, f, t); this.nextRight = nextRight;
5487	>	this.transformer = transformer;
5488	>	this.basis = basis; this.reducer = reducer;
5489	>	}
5490	>	public final Double getRawResult() { return result; }
5491	>	public final void compute() {
5492	>	final ToDoubleFunction<? super K> transformer;
5493	>	final DoubleBinaryOperator reducer;
5494	>	if ((transformer = this.transformer) != null &&
5495	>	(reducer = this.reducer) != null) {
5496	>	double r = this.basis;
5497	>	for (int i = baseIndex, f, h; batch > 0 &&
5498	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5499	>	addToPendingCount(1);
5500	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5501	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5502	>	rights, transformer, r, reducer)).fork();
5503	>	}
5504	>	for (Node<K,V> p; (p = advance()) != null; )
5505	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5506	>	result = r;
5507	>	CountedCompleter<?> c;
5508	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5509	>	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5510	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5511	>	s = t.rights;
5512	>	while (s != null) {
5513	>	t.result = reducer.applyAsDouble(t.result, s.result);
5514	>	s = t.rights = s.nextRight;
5515	>	}
5516	>	}
5517	>	}
5518	>	}
5519	>	}
5520	>
5521	>	@SuppressWarnings("serial")
5522	>	static final class MapReduceValuesToDoubleTask<K,V>
5523	>	extends BulkTask<K,V,Double> {
5524	>	final ToDoubleFunction<? super V> transformer;
5525	>	final DoubleBinaryOperator reducer;
5526	>	final double basis;
5527	>	double result;
5528	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5529	>	MapReduceValuesToDoubleTask
5530	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5531	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5532	>	ToDoubleFunction<? super V> transformer,
5533	>	double basis,
5534	>	DoubleBinaryOperator reducer) {
5535	>	super(p, b, i, f, t); this.nextRight = nextRight;
5536	>	this.transformer = transformer;
5537	>	this.basis = basis; this.reducer = reducer;
5538	>	}
5539	>	public final Double getRawResult() { return result; }
5540	>	public final void compute() {
5541	>	final ToDoubleFunction<? super V> transformer;
5542	>	final DoubleBinaryOperator reducer;
5543	>	if ((transformer = this.transformer) != null &&
5544	>	(reducer = this.reducer) != null) {
5545	>	double r = this.basis;
5546	>	for (int i = baseIndex, f, h; batch > 0 &&
5547	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5548	>	addToPendingCount(1);
5549	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5550	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5551	>	rights, transformer, r, reducer)).fork();
5552	>	}
5553	>	for (Node<K,V> p; (p = advance()) != null; )
5554	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5555	>	result = r;
5556	>	CountedCompleter<?> c;
5557	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5558	>	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5559	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5560	>	s = t.rights;
5561	>	while (s != null) {
5562	>	t.result = reducer.applyAsDouble(t.result, s.result);
5563	>	s = t.rights = s.nextRight;
5564	>	}
5565	>	}
5566	>	}
5567	>	}
5568	>	}
5569	>
5570	>	@SuppressWarnings("serial")
5571	>	static final class MapReduceEntriesToDoubleTask<K,V>
5572	>	extends BulkTask<K,V,Double> {
5573	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5574	>	final DoubleBinaryOperator reducer;
5575	>	final double basis;
5576	>	double result;
5577	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5578	>	MapReduceEntriesToDoubleTask
5579	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5580	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5581	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5582	>	double basis,
5583	>	DoubleBinaryOperator reducer) {
5584	>	super(p, b, i, f, t); this.nextRight = nextRight;
5585	>	this.transformer = transformer;
5586	>	this.basis = basis; this.reducer = reducer;
5587	>	}
5588	>	public final Double getRawResult() { return result; }
5589	>	public final void compute() {
5590	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5591	>	final DoubleBinaryOperator reducer;
5592	>	if ((transformer = this.transformer) != null &&
5593	>	(reducer = this.reducer) != null) {
5594	>	double r = this.basis;
5595	>	for (int i = baseIndex, f, h; batch > 0 &&
5596	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5597	>	addToPendingCount(1);
5598	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5599	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5600	>	rights, transformer, r, reducer)).fork();
5601	>	}
5602	>	for (Node<K,V> p; (p = advance()) != null; )
5603	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5604	>	result = r;
5605	>	CountedCompleter<?> c;
5606	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5607	>	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5608	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5609	>	s = t.rights;
5610	>	while (s != null) {
5611	>	t.result = reducer.applyAsDouble(t.result, s.result);
5612	>	s = t.rights = s.nextRight;
5613	>	}
5614	>	}
5615	>	}
5616	>	}
5617	>	}
5618	>
5619	>	@SuppressWarnings("serial")
5620	>	static final class MapReduceMappingsToDoubleTask<K,V>
5621	>	extends BulkTask<K,V,Double> {
5622	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5623	>	final DoubleBinaryOperator reducer;
5624	>	final double basis;
5625	>	double result;
5626	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5627	>	MapReduceMappingsToDoubleTask
5628	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5629	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5630	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5631	>	double basis,
5632	>	DoubleBinaryOperator reducer) {
5633	>	super(p, b, i, f, t); this.nextRight = nextRight;
5634	>	this.transformer = transformer;
5635	>	this.basis = basis; this.reducer = reducer;
5636	>	}
5637	>	public final Double getRawResult() { return result; }
5638	>	public final void compute() {
5639	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5640	>	final DoubleBinaryOperator reducer;
5641	>	if ((transformer = this.transformer) != null &&
5642	>	(reducer = this.reducer) != null) {
5643	>	double r = this.basis;
5644	>	for (int i = baseIndex, f, h; batch > 0 &&
5645	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5646	>	addToPendingCount(1);
5647	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5648	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5649	>	rights, transformer, r, reducer)).fork();
5650	>	}
5651	>	for (Node<K,V> p; (p = advance()) != null; )
5652	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5653	>	result = r;
5654	>	CountedCompleter<?> c;
5655	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5656	>	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5657	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5658	>	s = t.rights;
5659	>	while (s != null) {
5660	>	t.result = reducer.applyAsDouble(t.result, s.result);
5661	>	s = t.rights = s.nextRight;
5662	>	}
5663	>	}
5664	>	}
5665	>	}
5666	>	}
5667	>
5668	>	@SuppressWarnings("serial")
5669	>	static final class MapReduceKeysToLongTask<K,V>
5670	>	extends BulkTask<K,V,Long> {
5671	>	final ToLongFunction<? super K> transformer;
5672	>	final LongBinaryOperator reducer;
5673	>	final long basis;
5674	>	long result;
5675	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5676	>	MapReduceKeysToLongTask
5677	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5678	>	MapReduceKeysToLongTask<K,V> nextRight,
5679	>	ToLongFunction<? super K> transformer,
5680	>	long basis,
5681	>	LongBinaryOperator reducer) {
5682	>	super(p, b, i, f, t); this.nextRight = nextRight;
5683	>	this.transformer = transformer;
5684	>	this.basis = basis; this.reducer = reducer;
5685	>	}
5686	>	public final Long getRawResult() { return result; }
5687	>	public final void compute() {
5688	>	final ToLongFunction<? super K> transformer;
5689	>	final LongBinaryOperator reducer;
5690	>	if ((transformer = this.transformer) != null &&
5691	>	(reducer = this.reducer) != null) {
5692	>	long r = this.basis;
5693	>	for (int i = baseIndex, f, h; batch > 0 &&
5694	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5695	>	addToPendingCount(1);
5696	>	(rights = new MapReduceKeysToLongTask<K,V>
5697	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5698	>	rights, transformer, r, reducer)).fork();
5699	>	}
5700	>	for (Node<K,V> p; (p = advance()) != null; )
5701	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5702	>	result = r;
5703	>	CountedCompleter<?> c;
5704	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5705	>	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5706	>	t = (MapReduceKeysToLongTask<K,V>)c,
5707	>	s = t.rights;
5708	>	while (s != null) {
5709	>	t.result = reducer.applyAsLong(t.result, s.result);
5710	>	s = t.rights = s.nextRight;
5711	>	}
5712	>	}
5713	>	}
5714	>	}
5715	>	}
5716	>
5717	>	@SuppressWarnings("serial")
5718	>	static final class MapReduceValuesToLongTask<K,V>
5719	>	extends BulkTask<K,V,Long> {
5720	>	final ToLongFunction<? super V> transformer;
5721	>	final LongBinaryOperator reducer;
5722	>	final long basis;
5723	>	long result;
5724	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5725	>	MapReduceValuesToLongTask
5726	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5727	>	MapReduceValuesToLongTask<K,V> nextRight,
5728	>	ToLongFunction<? super V> transformer,
5729	>	long basis,
5730	>	LongBinaryOperator reducer) {
5731	>	super(p, b, i, f, t); this.nextRight = nextRight;
5732	>	this.transformer = transformer;
5733	>	this.basis = basis; this.reducer = reducer;
5734	>	}
5735	>	public final Long getRawResult() { return result; }
5736	>	public final void compute() {
5737	>	final ToLongFunction<? super V> transformer;
5738	>	final LongBinaryOperator reducer;
5739	>	if ((transformer = this.transformer) != null &&
5740	>	(reducer = this.reducer) != null) {
5741	>	long r = this.basis;
5742	>	for (int i = baseIndex, f, h; batch > 0 &&
5743	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5744	>	addToPendingCount(1);
5745	>	(rights = new MapReduceValuesToLongTask<K,V>
5746	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5747	>	rights, transformer, r, reducer)).fork();
5748	>	}
5749	>	for (Node<K,V> p; (p = advance()) != null; )
5750	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5751	>	result = r;
5752	>	CountedCompleter<?> c;
5753	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5754	>	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5755	>	t = (MapReduceValuesToLongTask<K,V>)c,
5756	>	s = t.rights;
5757	>	while (s != null) {
5758	>	t.result = reducer.applyAsLong(t.result, s.result);
5759	>	s = t.rights = s.nextRight;
5760	>	}
5761	>	}
5762	>	}
5763	>	}
5764	>	}
5765	>
5766	>	@SuppressWarnings("serial")
5767	>	static final class MapReduceEntriesToLongTask<K,V>
5768	>	extends BulkTask<K,V,Long> {
5769	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5770	>	final LongBinaryOperator reducer;
5771	>	final long basis;
5772	>	long result;
5773	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5774	>	MapReduceEntriesToLongTask
5775	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5776	>	MapReduceEntriesToLongTask<K,V> nextRight,
5777	>	ToLongFunction<Map.Entry<K,V>> transformer,
5778	>	long basis,
5779	>	LongBinaryOperator reducer) {
5780	>	super(p, b, i, f, t); this.nextRight = nextRight;
5781	>	this.transformer = transformer;
5782	>	this.basis = basis; this.reducer = reducer;
5783	>	}
5784	>	public final Long getRawResult() { return result; }
5785	>	public final void compute() {
5786	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5787	>	final LongBinaryOperator reducer;
5788	>	if ((transformer = this.transformer) != null &&
5789	>	(reducer = this.reducer) != null) {
5790	>	long r = this.basis;
5791	>	for (int i = baseIndex, f, h; batch > 0 &&
5792	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5793	>	addToPendingCount(1);
5794	>	(rights = new MapReduceEntriesToLongTask<K,V>
5795	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5796	>	rights, transformer, r, reducer)).fork();
5797	>	}
5798	>	for (Node<K,V> p; (p = advance()) != null; )
5799	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5800	>	result = r;
5801	>	CountedCompleter<?> c;
5802	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5803	>	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5804	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5805	>	s = t.rights;
5806	>	while (s != null) {
5807	>	t.result = reducer.applyAsLong(t.result, s.result);
5808	>	s = t.rights = s.nextRight;
5809	>	}
5810	>	}
5811	>	}
5812	>	}
5813	>	}
5814	>
5815	>	@SuppressWarnings("serial")
5816	>	static final class MapReduceMappingsToLongTask<K,V>
5817	>	extends BulkTask<K,V,Long> {
5818	>	final ToLongBiFunction<? super K, ? super V> transformer;
5819	>	final LongBinaryOperator reducer;
5820	>	final long basis;
5821	>	long result;
5822	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5823	>	MapReduceMappingsToLongTask
5824	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5825	>	MapReduceMappingsToLongTask<K,V> nextRight,
5826	>	ToLongBiFunction<? super K, ? super V> transformer,
5827	>	long basis,
5828	>	LongBinaryOperator reducer) {
5829	>	super(p, b, i, f, t); this.nextRight = nextRight;
5830	>	this.transformer = transformer;
5831	>	this.basis = basis; this.reducer = reducer;
5832	>	}
5833	>	public final Long getRawResult() { return result; }
5834	>	public final void compute() {
5835	>	final ToLongBiFunction<? super K, ? super V> transformer;
5836	>	final LongBinaryOperator reducer;
5837	>	if ((transformer = this.transformer) != null &&
5838	>	(reducer = this.reducer) != null) {
5839	>	long r = this.basis;
5840	>	for (int i = baseIndex, f, h; batch > 0 &&
5841	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5842	>	addToPendingCount(1);
5843	>	(rights = new MapReduceMappingsToLongTask<K,V>
5844	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5845	>	rights, transformer, r, reducer)).fork();
5846	>	}
5847	>	for (Node<K,V> p; (p = advance()) != null; )
5848	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
5849	>	result = r;
5850	>	CountedCompleter<?> c;
5851	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5852	>	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5853	>	t = (MapReduceMappingsToLongTask<K,V>)c,
5854	>	s = t.rights;
5855	>	while (s != null) {
5856	>	t.result = reducer.applyAsLong(t.result, s.result);
5857	>	s = t.rights = s.nextRight;
5858	>	}
5859	>	}
5860	>	}
5861	>	}
5862	>	}
5863	>
5864	>	@SuppressWarnings("serial")
5865	>	static final class MapReduceKeysToIntTask<K,V>
5866	>	extends BulkTask<K,V,Integer> {
5867	>	final ToIntFunction<? super K> transformer;
5868	>	final IntBinaryOperator reducer;
5869	>	final int basis;
5870	>	int result;
5871	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
5872	>	MapReduceKeysToIntTask
5873	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5874	>	MapReduceKeysToIntTask<K,V> nextRight,
5875	>	ToIntFunction<? super K> transformer,
5876	>	int basis,
5877	>	IntBinaryOperator reducer) {
5878	>	super(p, b, i, f, t); this.nextRight = nextRight;
5879	>	this.transformer = transformer;
5880	>	this.basis = basis; this.reducer = reducer;
5881	>	}
5882	>	public final Integer getRawResult() { return result; }
5883	>	public final void compute() {
5884	>	final ToIntFunction<? super K> transformer;
5885	>	final IntBinaryOperator reducer;
5886	>	if ((transformer = this.transformer) != null &&
5887	>	(reducer = this.reducer) != null) {
5888	>	int r = this.basis;
5889	>	for (int i = baseIndex, f, h; batch > 0 &&
5890	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5891	>	addToPendingCount(1);
5892	>	(rights = new MapReduceKeysToIntTask<K,V>
5893	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5894	>	rights, transformer, r, reducer)).fork();
5895	>	}
5896	>	for (Node<K,V> p; (p = advance()) != null; )
5897	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
5898	>	result = r;
5899	>	CountedCompleter<?> c;
5900	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5901	>	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5902	>	t = (MapReduceKeysToIntTask<K,V>)c,
5903	>	s = t.rights;
5904	>	while (s != null) {
5905	>	t.result = reducer.applyAsInt(t.result, s.result);
5906	>	s = t.rights = s.nextRight;
5907	>	}
5908	>	}
5909	>	}
5910	>	}
5911	>	}
5912	>
5913	>	@SuppressWarnings("serial")
5914	>	static final class MapReduceValuesToIntTask<K,V>
5915	>	extends BulkTask<K,V,Integer> {
5916	>	final ToIntFunction<? super V> transformer;
5917	>	final IntBinaryOperator reducer;
5918	>	final int basis;
5919	>	int result;
5920	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
5921	>	MapReduceValuesToIntTask
5922	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5923	>	MapReduceValuesToIntTask<K,V> nextRight,
5924	>	ToIntFunction<? super V> transformer,
5925	>	int basis,
5926	>	IntBinaryOperator reducer) {
5927	>	super(p, b, i, f, t); this.nextRight = nextRight;
5928	>	this.transformer = transformer;
5929	>	this.basis = basis; this.reducer = reducer;
5930	>	}
5931	>	public final Integer getRawResult() { return result; }
5932	>	public final void compute() {
5933	>	final ToIntFunction<? super V> transformer;
5934	>	final IntBinaryOperator reducer;
5935	>	if ((transformer = this.transformer) != null &&
5936	>	(reducer = this.reducer) != null) {
5937	>	int r = this.basis;
5938	>	for (int i = baseIndex, f, h; batch > 0 &&
5939	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5940	>	addToPendingCount(1);
5941	>	(rights = new MapReduceValuesToIntTask<K,V>
5942	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5943	>	rights, transformer, r, reducer)).fork();
5944	>	}
5945	>	for (Node<K,V> p; (p = advance()) != null; )
5946	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5947	>	result = r;
5948	>	CountedCompleter<?> c;
5949	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5950	>	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5951	>	t = (MapReduceValuesToIntTask<K,V>)c,
5952	>	s = t.rights;
5953	>	while (s != null) {
5954	>	t.result = reducer.applyAsInt(t.result, s.result);
5955	>	s = t.rights = s.nextRight;
5956	>	}
5957	>	}
5958	>	}
5959	>	}
5960	>	}
5961	>
5962	>	@SuppressWarnings("serial")
5963	>	static final class MapReduceEntriesToIntTask<K,V>
5964	>	extends BulkTask<K,V,Integer> {
5965	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5966	>	final IntBinaryOperator reducer;
5967	>	final int basis;
5968	>	int result;
5969	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5970	>	MapReduceEntriesToIntTask
5971	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5972	>	MapReduceEntriesToIntTask<K,V> nextRight,
5973	>	ToIntFunction<Map.Entry<K,V>> transformer,
5974	>	int basis,
5975	>	IntBinaryOperator reducer) {
5976	>	super(p, b, i, f, t); this.nextRight = nextRight;
5977	>	this.transformer = transformer;
5978	>	this.basis = basis; this.reducer = reducer;
5979	>	}
5980	>	public final Integer getRawResult() { return result; }
5981	>	public final void compute() {
5982	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5983	>	final IntBinaryOperator reducer;
5984	>	if ((transformer = this.transformer) != null &&
5985	>	(reducer = this.reducer) != null) {
5986	>	int r = this.basis;
5987	>	for (int i = baseIndex, f, h; batch > 0 &&
5988	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5989	>	addToPendingCount(1);
5990	>	(rights = new MapReduceEntriesToIntTask<K,V>
5991	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5992	>	rights, transformer, r, reducer)).fork();
5993	>	}
5994	>	for (Node<K,V> p; (p = advance()) != null; )
5995	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
5996	>	result = r;
5997	>	CountedCompleter<?> c;
5998	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5999	>	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
6000	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6001	>	s = t.rights;
6002	>	while (s != null) {
6003	>	t.result = reducer.applyAsInt(t.result, s.result);
6004	>	s = t.rights = s.nextRight;
6005	>	}
6006	>	}
6007	>	}
6008	>	}
6009	>	}
6010	>
6011	>	@SuppressWarnings("serial")
6012	>	static final class MapReduceMappingsToIntTask<K,V>
6013	>	extends BulkTask<K,V,Integer> {
6014	>	final ToIntBiFunction<? super K, ? super V> transformer;
6015	>	final IntBinaryOperator reducer;
6016	>	final int basis;
6017	>	int result;
6018	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6019	>	MapReduceMappingsToIntTask
6020	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6021	>	MapReduceMappingsToIntTask<K,V> nextRight,
6022	>	ToIntBiFunction<? super K, ? super V> transformer,
6023	>	int basis,
6024	>	IntBinaryOperator reducer) {
6025	>	super(p, b, i, f, t); this.nextRight = nextRight;
6026	>	this.transformer = transformer;
6027	>	this.basis = basis; this.reducer = reducer;
6028	>	}
6029	>	public final Integer getRawResult() { return result; }
6030	>	public final void compute() {
6031	>	final ToIntBiFunction<? super K, ? super V> transformer;
6032	>	final IntBinaryOperator reducer;
6033	>	if ((transformer = this.transformer) != null &&
6034	>	(reducer = this.reducer) != null) {
6035	>	int r = this.basis;
6036	>	for (int i = baseIndex, f, h; batch > 0 &&
6037	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6038	>	addToPendingCount(1);
6039	>	(rights = new MapReduceMappingsToIntTask<K,V>
6040	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6041	>	rights, transformer, r, reducer)).fork();
6042	>	}
6043	>	for (Node<K,V> p; (p = advance()) != null; )
6044	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6045	>	result = r;
6046	>	CountedCompleter<?> c;
6047	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6048	>	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6049	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6050	>	s = t.rights;
6051	>	while (s != null) {
6052	>	t.result = reducer.applyAsInt(t.result, s.result);
6053	>	s = t.rights = s.nextRight;
6054	>	}
6055	>	}
6056	>	}
6057	>	}
6058	>	}
6059	>
6060	>	// Unsafe mechanics
6061	>	private static final sun.misc.Unsafe U;
6062	>	private static final long SIZECTL;
6063	>	private static final long TRANSFERINDEX;
6064	>	private static final long TRANSFERORIGIN;
6065	>	private static final long BASECOUNT;
6066	>	private static final long CELLSBUSY;
6067	>	private static final long CELLVALUE;
6068	>	private static final long ABASE;
6069	>	private static final int ASHIFT;
6070	>
6071	>	static {
6072	>	try {
6073	>	U = sun.misc.Unsafe.getUnsafe();
6074	>	Class<?> k = ConcurrentHashMap.class;
6075	>	SIZECTL = U.objectFieldOffset
6076	>	(k.getDeclaredField("sizeCtl"));
6077	>	TRANSFERINDEX = U.objectFieldOffset
6078	>	(k.getDeclaredField("transferIndex"));
6079	>	TRANSFERORIGIN = U.objectFieldOffset
6080	>	(k.getDeclaredField("transferOrigin"));
6081	>	BASECOUNT = U.objectFieldOffset
6082	>	(k.getDeclaredField("baseCount"));
6083	>	CELLSBUSY = U.objectFieldOffset
6084	>	(k.getDeclaredField("cellsBusy"));
6085	>	Class<?> ck = CounterCell.class;
6086	>	CELLVALUE = U.objectFieldOffset
6087	>	(ck.getDeclaredField("value"));
6088	>	Class<?> ak = Node[].class;
6089	>	ABASE = U.arrayBaseOffset(ak);
6090	>	int scale = U.arrayIndexScale(ak);
6091	>	if ((scale & (scale - 1)) != 0)
6092	>	throw new Error("data type scale not a power of two");
6093	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6094	>	} catch (Exception e) {
6095	>	throw new Error(e);
6096		}
6097		}
6098		}

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