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Revision 1.92 by dl, Sat Dec 2 20:55:01 2006 UTC vs.
Revision 1.226 by jsr166, Tue Jun 18 17:57:21 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.Arrays;
14	>	import java.util.Collection;
15	>	import java.util.Comparator;
16	>	import java.util.ConcurrentModificationException;
17	>	import java.util.Enumeration;
18	>	import java.util.HashMap;
19	>	import java.util.Hashtable;
20	>	import java.util.Iterator;
21	>	import java.util.Map;
22	>	import java.util.NoSuchElementException;
23	>	import java.util.Set;
24	>	import java.util.Spliterator;
25	>	import java.util.concurrent.ConcurrentMap;
26	>	import java.util.concurrent.ForkJoinPool;
27	>	import java.util.concurrent.atomic.AtomicReference;
28	>	import java.util.concurrent.locks.LockSupport;
29	>	import java.util.concurrent.locks.ReentrantLock;
30	>	import java.util.function.BiConsumer;
31	>	import java.util.function.BiFunction;
32	>	import java.util.function.BinaryOperator;
33	>	import java.util.function.Consumer;
34	>	import java.util.function.DoubleBinaryOperator;
35	>	import java.util.function.Function;
36	>	import java.util.function.IntBinaryOperator;
37	>	import java.util.function.LongBinaryOperator;
38	>	import java.util.function.ToDoubleBiFunction;
39	>	import java.util.function.ToDoubleFunction;
40	>	import java.util.function.ToIntBiFunction;
41	>	import java.util.function.ToIntFunction;
42	>	import java.util.function.ToLongBiFunction;
43	>	import java.util.function.ToLongFunction;
44	>	import java.util.stream.Stream;
45
46		/**
47		* A hash table supporting full concurrency of retrievals and
48	<	* adjustable expected concurrency for updates. This class obeys the
48	>	* high expected concurrency for updates. This class obeys the
49		* same functional specification as {@link java.util.Hashtable}, and
50		* includes versions of methods corresponding to each method of
51	<	* <tt>Hashtable</tt>. However, even though all operations are
51	>	* {@code Hashtable}. However, even though all operations are
52		* thread-safe, retrieval operations do <em>not</em> entail locking,
53		* and there is <em>not</em> any support for locking the entire table
54		* in a way that prevents all access.  This class is fully
55	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
55	>	* interoperable with {@code Hashtable} in programs that rely on its
56		* thread safety but not on its synchronization details.
57		*
58	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
59	<	* block, so may overlap with update operations (including
60	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
61	<	* of the most recently <em>completed</em> update operations holding
62	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
63	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
64	<	* removal of only some entries.  Similarly, Iterators and
65	<	* Enumerations return elements reflecting the state of the hash table
66	<	* at some point at or since the creation of the iterator/enumeration.
67	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
68	<	* However, iterators are designed to be used by only one thread at a time.
69	<	*
70	<	* <p> The allowed concurrency among update operations is guided by
71	<	* the optional <tt>concurrencyLevel</tt> constructor argument
72	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
73	<	* table is internally partitioned to try to permit the indicated
74	<	* number of concurrent updates without contention. Because placement
75	<	* in hash tables is essentially random, the actual concurrency will
76	<	* vary.  Ideally, you should choose a value to accommodate as many
77	<	* threads as will ever concurrently modify the table. Using a
78	<	* significantly higher value than you need can waste space and time,
79	<	* and a significantly lower value can lead to thread contention. But
80	<	* overestimates and underestimates within an order of magnitude do
81	<	* not usually have much noticeable impact. A value of one is
82	<	* appropriate when it is known that only one thread will modify and
83	<	* all others will only read. Also, resizing this or any other kind of
84	<	* hash table is a relatively slow operation, so, when possible, it is
85	<	* a good idea to provide estimates of expected table sizes in
86	<	* constructors.
58	>	* <p>Retrieval operations (including {@code get}) generally do not
59	>	* block, so may overlap with update operations (including {@code put}
60	>	* and {@code remove}). Retrievals reflect the results of the most
61	>	* recently <em>completed</em> update operations holding upon their
62	>	* onset. (More formally, an update operation for a given key bears a
63	>	* <em>happens-before</em> relation with any (non-null) retrieval for
64	>	* that key reporting the updated value.)  For aggregate operations
65	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
66	>	* reflect insertion or removal of only some entries.  Similarly,
67	>	* Iterators and Enumerations return elements reflecting the state of
68	>	* the hash table at some point at or since the creation of the
69	>	* iterator/enumeration.  They do <em>not</em> throw {@link
70	>	* ConcurrentModificationException}.  However, iterators are designed
71	>	* to be used by only one thread at a time.  Bear in mind that the
72	>	* results of aggregate status methods including {@code size}, {@code
73	>	* isEmpty}, and {@code containsValue} are typically useful only when
74	>	* a map is not undergoing concurrent updates in other threads.
75	>	* Otherwise the results of these methods reflect transient states
76	>	* that may be adequate for monitoring or estimation purposes, but not
77	>	* for program control.
78	>	*
79	>	* <p>The table is dynamically expanded when there are too many
80	>	* collisions (i.e., keys that have distinct hash codes but fall into
81	>	* the same slot modulo the table size), with the expected average
82	>	* effect of maintaining roughly two bins per mapping (corresponding
83	>	* to a 0.75 load factor threshold for resizing). There may be much
84	>	* variance around this average as mappings are added and removed, but
85	>	* overall, this maintains a commonly accepted time/space tradeoff for
86	>	* hash tables.  However, resizing this or any other kind of hash
87	>	* table may be a relatively slow operation. When possible, it is a
88	>	* good idea to provide a size estimate as an optional {@code
89	>	* initialCapacity} constructor argument. An additional optional
90	>	* {@code loadFactor} constructor argument provides a further means of
91	>	* customizing initial table capacity by specifying the table density
92	>	* to be used in calculating the amount of space to allocate for the
93	>	* given number of elements.  Also, for compatibility with previous
94	>	* versions of this class, constructors may optionally specify an
95	>	* expected {@code concurrencyLevel} as an additional hint for
96	>	* internal sizing.  Note that using many keys with exactly the same
97	>	* {@code hashCode()} is a sure way to slow down performance of any
98	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
99	>	* this class may use comparison order among keys to help break ties.
100	>	*
101	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
102	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
103	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
104	>	* mapped values are (perhaps transiently) not used or all take the
105	>	* same mapping value.
106	>	*
107	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
108	>	* form of histogram or multiset) by using {@link
109	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
110	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
111	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
112	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
113		*
114		* <p>This class and its views and iterators implement all of the
115		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
116		* interfaces.
117		*
118	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
119	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
118	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
119	>	* does <em>not</em> allow {@code null} to be used as a key or value.
120	>	*
121	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
122	>	* operations that, unlike most {@link Stream} methods, are designed
123	>	* to be safely, and often sensibly, applied even with maps that are
124	>	* being concurrently updated by other threads; for example, when
125	>	* computing a snapshot summary of the values in a shared registry.
126	>	* There are three kinds of operation, each with four forms, accepting
127	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
128	>	* and/or return values. Because the elements of a ConcurrentHashMap
129	>	* are not ordered in any particular way, and may be processed in
130	>	* different orders in different parallel executions, the correctness
131	>	* of supplied functions should not depend on any ordering, or on any
132	>	* other objects or values that may transiently change while
133	>	* computation is in progress; and except for forEach actions, should
134	>	* ideally be side-effect-free. Bulk operations on {@link Map.Entry}
135	>	* objects do not support method {@code setValue}.
136	>	*
137	>	* <ul>
138	>	* <li> forEach: Perform a given action on each element.
139	>	* A variant form applies a given transformation on each element
140	>	* before performing the action.</li>
141	>	*
142	>	* <li> search: Return the first available non-null result of
143	>	* applying a given function on each element; skipping further
144	>	* search when a result is found.</li>
145	>	*
146	>	* <li> reduce: Accumulate each element.  The supplied reduction
147	>	* function cannot rely on ordering (more formally, it should be
148	>	* both associative and commutative).  There are five variants:
149	>	*
150	>	* <ul>
151	>	*
152	>	* <li> Plain reductions. (There is not a form of this method for
153	>	* (key, value) function arguments since there is no corresponding
154	>	* return type.)</li>
155	>	*
156	>	* <li> Mapped reductions that accumulate the results of a given
157	>	* function applied to each element.</li>
158	>	*
159	>	* <li> Reductions to scalar doubles, longs, and ints, using a
160	>	* given basis value.</li>
161	>	*
162	>	* </ul>
163	>	* </li>
164	>	* </ul>
165	>	*
166	>	* <p>These bulk operations accept a {@code parallelismThreshold}
167	>	* argument. Methods proceed sequentially if the current map size is
168	>	* estimated to be less than the given threshold. Using a value of
169	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
170	>	* of {@code 1} results in maximal parallelism by partitioning into
171	>	* enough subtasks to fully utilize the {@link
172	>	* ForkJoinPool#commonPool()} that is used for all parallel
173	>	* computations. Normally, you would initially choose one of these
174	>	* extreme values, and then measure performance of using in-between
175	>	* values that trade off overhead versus throughput.
176	>	*
177	>	* <p>The concurrency properties of bulk operations follow
178	>	* from those of ConcurrentHashMap: Any non-null result returned
179	>	* from {@code get(key)} and related access methods bears a
180	>	* happens-before relation with the associated insertion or
181	>	* update.  The result of any bulk operation reflects the
182	>	* composition of these per-element relations (but is not
183	>	* necessarily atomic with respect to the map as a whole unless it
184	>	* is somehow known to be quiescent).  Conversely, because keys
185	>	* and values in the map are never null, null serves as a reliable
186	>	* atomic indicator of the current lack of any result.  To
187	>	* maintain this property, null serves as an implicit basis for
188	>	* all non-scalar reduction operations. For the double, long, and
189	>	* int versions, the basis should be one that, when combined with
190	>	* any other value, returns that other value (more formally, it
191	>	* should be the identity element for the reduction). Most common
192	>	* reductions have these properties; for example, computing a sum
193	>	* with basis 0 or a minimum with basis MAX_VALUE.
194	>	*
195	>	* <p>Search and transformation functions provided as arguments
196	>	* should similarly return null to indicate the lack of any result
197	>	* (in which case it is not used). In the case of mapped
198	>	* reductions, this also enables transformations to serve as
199	>	* filters, returning null (or, in the case of primitive
200	>	* specializations, the identity basis) if the element should not
201	>	* be combined. You can create compound transformations and
202	>	* filterings by composing them yourself under this "null means
203	>	* there is nothing there now" rule before using them in search or
204	>	* reduce operations.
205	>	*
206	>	* <p>Methods accepting and/or returning Entry arguments maintain
207	>	* key-value associations. They may be useful for example when
208	>	* finding the key for the greatest value. Note that "plain" Entry
209	>	* arguments can be supplied using {@code new
210	>	* AbstractMap.SimpleEntry(k,v)}.
211	>	*
212	>	* <p>Bulk operations may complete abruptly, throwing an
213	>	* exception encountered in the application of a supplied
214	>	* function. Bear in mind when handling such exceptions that other
215	>	* concurrently executing functions could also have thrown
216	>	* exceptions, or would have done so if the first exception had
217	>	* not occurred.
218	>	*
219	>	* <p>Speedups for parallel compared to sequential forms are common
220	>	* but not guaranteed.  Parallel operations involving brief functions
221	>	* on small maps may execute more slowly than sequential forms if the
222	>	* underlying work to parallelize the computation is more expensive
223	>	* than the computation itself.  Similarly, parallelization may not
224	>	* lead to much actual parallelism if all processors are busy
225	>	* performing unrelated tasks.
226	>	*
227	>	* <p>All arguments to all task methods must be non-null.
228		*
229		* <p>This class is a member of the
230		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 235 | import java.io.ObjectOutputStream;
235		* @param <K> the type of keys maintained by this map
236		* @param <V> the type of mapped values
237		*/
238	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
74	<	implements ConcurrentMap<K, V>, Serializable {
238	>	public class ConcurrentHashMap<K,V> implements ConcurrentMap<K,V>, Serializable {
239		private static final long serialVersionUID = 7249069246763182397L;
240
241		/*
242	<	* The basic strategy is to subdivide the table among Segments,
243	<	* each of which itself is a concurrently readable hash table.
242	>	* Overview:
243	>	*
244	>	* The primary design goal of this hash table is to maintain
245	>	* concurrent readability (typically method get(), but also
246	>	* iterators and related methods) while minimizing update
247	>	* contention. Secondary goals are to keep space consumption about
248	>	* the same or better than java.util.HashMap, and to support high
249	>	* initial insertion rates on an empty table by many threads.
250	>	*
251	>	* This map usually acts as a binned (bucketed) hash table.  Each
252	>	* key-value mapping is held in a Node.  Most nodes are instances
253	>	* of the basic Node class with hash, key, value, and next
254	>	* fields. However, various subclasses exist: TreeNodes are
255	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
256	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
257	>	* of bins during resizing. ReservationNodes are used as
258	>	* placeholders while establishing values in computeIfAbsent and
259	>	* related methods.  The types TreeBin, ForwardingNode, and
260	>	* ReservationNode do not hold normal user keys, values, or
261	>	* hashes, and are readily distinguishable during search etc
262	>	* because they have negative hash fields and null key and value
263	>	* fields. (These special nodes are either uncommon or transient,
264	>	* so the impact of carrying around some unused fields is
265	>	* insignficant.)
266	>	*
267	>	* The table is lazily initialized to a power-of-two size upon the
268	>	* first insertion.  Each bin in the table normally contains a
269	>	* list of Nodes (most often, the list has only zero or one Node).
270	>	* Table accesses require volatile/atomic reads, writes, and
271	>	* CASes.  Because there is no other way to arrange this without
272	>	* adding further indirections, we use intrinsics
273	>	* (sun.misc.Unsafe) operations.
274	>	*
275	>	* We use the top (sign) bit of Node hash fields for control
276	>	* purposes -- it is available anyway because of addressing
277	>	* constraints.  Nodes with negative hash fields are specially
278	>	* handled or ignored in map methods.
279	>	*
280	>	* Insertion (via put or its variants) of the first node in an
281	>	* empty bin is performed by just CASing it to the bin.  This is
282	>	* by far the most common case for put operations under most
283	>	* key/hash distributions.  Other update operations (insert,
284	>	* delete, and replace) require locks.  We do not want to waste
285	>	* the space required to associate a distinct lock object with
286	>	* each bin, so instead use the first node of a bin list itself as
287	>	* a lock. Locking support for these locks relies on builtin
288	>	* "synchronized" monitors.
289	>	*
290	>	* Using the first node of a list as a lock does not by itself
291	>	* suffice though: When a node is locked, any update must first
292	>	* validate that it is still the first node after locking it, and
293	>	* retry if not. Because new nodes are always appended to lists,
294	>	* once a node is first in a bin, it remains first until deleted
295	>	* or the bin becomes invalidated (upon resizing).
296	>	*
297	>	* The main disadvantage of per-bin locks is that other update
298	>	* operations on other nodes in a bin list protected by the same
299	>	* lock can stall, for example when user equals() or mapping
300	>	* functions take a long time.  However, statistically, under
301	>	* random hash codes, this is not a common problem.  Ideally, the
302	>	* frequency of nodes in bins follows a Poisson distribution
303	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
304	>	* parameter of about 0.5 on average, given the resizing threshold
305	>	* of 0.75, although with a large variance because of resizing
306	>	* granularity. Ignoring variance, the expected occurrences of
307	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
308	>	* first values are:
309	>	*
310	>	* 0:    0.60653066
311	>	* 1:    0.30326533
312	>	* 2:    0.07581633
313	>	* 3:    0.01263606
314	>	* 4:    0.00157952
315	>	* 5:    0.00015795
316	>	* 6:    0.00001316
317	>	* 7:    0.00000094
318	>	* 8:    0.00000006
319	>	* more: less than 1 in ten million
320	>	*
321	>	* Lock contention probability for two threads accessing distinct
322	>	* elements is roughly 1 / (8 * #elements) under random hashes.
323	>	*
324	>	* Actual hash code distributions encountered in practice
325	>	* sometimes deviate significantly from uniform randomness.  This
326	>	* includes the case when N > (1<<30), so some keys MUST collide.
327	>	* Similarly for dumb or hostile usages in which multiple keys are
328	>	* designed to have identical hash codes or ones that differs only
329	>	* in masked-out high bits. So we use a secondary strategy that
330	>	* applies when the number of nodes in a bin exceeds a
331	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
332	>	* specialized form of red-black trees), bounding search time to
333	>	* O(log N).  Each search step in a TreeBin is at least twice as
334	>	* slow as in a regular list, but given that N cannot exceed
335	>	* (1<<64) (before running out of addresses) this bounds search
336	>	* steps, lock hold times, etc, to reasonable constants (roughly
337	>	* 100 nodes inspected per operation worst case) so long as keys
338	>	* are Comparable (which is very common -- String, Long, etc).
339	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
340	>	* traversal pointers as regular nodes, so can be traversed in
341	>	* iterators in the same way.
342	>	*
343	>	* The table is resized when occupancy exceeds a percentage
344	>	* threshold (nominally, 0.75, but see below).  Any thread
345	>	* noticing an overfull bin may assist in resizing after the
346	>	* initiating thread allocates and sets up the replacement
347	>	* array. However, rather than stalling, these other threads may
348	>	* proceed with insertions etc.  The use of TreeBins shields us
349	>	* from the worst case effects of overfilling while resizes are in
350	>	* progress.  Resizing proceeds by transferring bins, one by one,
351	>	* from the table to the next table. To enable concurrency, the
352	>	* next table must be (incrementally) prefilled with place-holders
353	>	* serving as reverse forwarders to the old table.  Because we are
354	>	* using power-of-two expansion, the elements from each bin must
355	>	* either stay at same index, or move with a power of two
356	>	* offset. We eliminate unnecessary node creation by catching
357	>	* cases where old nodes can be reused because their next fields
358	>	* won't change.  On average, only about one-sixth of them need
359	>	* cloning when a table doubles. The nodes they replace will be
360	>	* garbage collectable as soon as they are no longer referenced by
361	>	* any reader thread that may be in the midst of concurrently
362	>	* traversing table.  Upon transfer, the old table bin contains
363	>	* only a special forwarding node (with hash field "MOVED") that
364	>	* contains the next table as its key. On encountering a
365	>	* forwarding node, access and update operations restart, using
366	>	* the new table.
367	>	*
368	>	* Each bin transfer requires its bin lock, which can stall
369	>	* waiting for locks while resizing. However, because other
370	>	* threads can join in and help resize rather than contend for
371	>	* locks, average aggregate waits become shorter as resizing
372	>	* progresses.  The transfer operation must also ensure that all
373	>	* accessible bins in both the old and new table are usable by any
374	>	* traversal.  This is arranged by proceeding from the last bin
375	>	* (table.length - 1) up towards the first.  Upon seeing a
376	>	* forwarding node, traversals (see class Traverser) arrange to
377	>	* move to the new table without revisiting nodes.  However, to
378	>	* ensure that no intervening nodes are skipped, bin splitting can
379	>	* only begin after the associated reverse-forwarders are in
380	>	* place.
381	>	*
382	>	* The traversal scheme also applies to partial traversals of
383	>	* ranges of bins (via an alternate Traverser constructor)
384	>	* to support partitioned aggregate operations.  Also, read-only
385	>	* operations give up if ever forwarded to a null table, which
386	>	* provides support for shutdown-style clearing, which is also not
387	>	* currently implemented.
388	>	*
389	>	* Lazy table initialization minimizes footprint until first use,
390	>	* and also avoids resizings when the first operation is from a
391	>	* putAll, constructor with map argument, or deserialization.
392	>	* These cases attempt to override the initial capacity settings,
393	>	* but harmlessly fail to take effect in cases of races.
394	>	*
395	>	* The element count is maintained using a specialization of
396	>	* LongAdder. We need to incorporate a specialization rather than
397	>	* just use a LongAdder in order to access implicit
398	>	* contention-sensing that leads to creation of multiple
399	>	* CounterCells.  The counter mechanics avoid contention on
400	>	* updates but can encounter cache thrashing if read too
401	>	* frequently during concurrent access. To avoid reading so often,
402	>	* resizing under contention is attempted only upon adding to a
403	>	* bin already holding two or more nodes. Under uniform hash
404	>	* distributions, the probability of this occurring at threshold
405	>	* is around 13%, meaning that only about 1 in 8 puts check
406	>	* threshold (and after resizing, many fewer do so).
407	>	*
408	>	* TreeBins use a special form of comparison for search and
409	>	* related operations (which is the main reason we cannot use
410	>	* existing collections such as TreeMaps). TreeBins contain
411	>	* Comparable elements, but may contain others, as well as
412	>	* elements that are Comparable but not necessarily Comparable
413	>	* for the same T, so we cannot invoke compareTo among them. To
414	>	* handle this, the tree is ordered primarily by hash value, then
415	>	* by Comparable.compareTo order if applicable.  On lookup at a
416	>	* node, if elements are not comparable or compare as 0 then both
417	>	* left and right children may need to be searched in the case of
418	>	* tied hash values. (This corresponds to the full list search
419	>	* that would be necessary if all elements were non-Comparable and
420	>	* had tied hashes.)  The red-black balancing code is updated from
421	>	* pre-jdk-collections
422	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
423	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
424	>	* Algorithms" (CLR).
425	>	*
426	>	* TreeBins also require an additional locking mechanism.  While
427	>	* list traversal is always possible by readers even during
428	>	* updates, tree traversal is not, mainly beause of tree-rotations
429	>	* that may change the root node and/or its linkages.  TreeBins
430	>	* include a simple read-write lock mechanism parasitic on the
431	>	* main bin-synchronization strategy: Structural adjustments
432	>	* associated with an insertion or removal are already bin-locked
433	>	* (and so cannot conflict with other writers) but must wait for
434	>	* ongoing readers to finish. Since there can be only one such
435	>	* waiter, we use a simple scheme using a single "waiter" field to
436	>	* block writers.  However, readers need never block.  If the root
437	>	* lock is held, they proceed along the slow traversal path (via
438	>	* next-pointers) until the lock becomes available or the list is
439	>	* exhausted, whichever comes first. These cases are not fast, but
440	>	* maximize aggregate expected throughput.
441	>	*
442	>	* Maintaining API and serialization compatibility with previous
443	>	* versions of this class introduces several oddities. Mainly: We
444	>	* leave untouched but unused constructor arguments refering to
445	>	* concurrencyLevel. We accept a loadFactor constructor argument,
446	>	* but apply it only to initial table capacity (which is the only
447	>	* time that we can guarantee to honor it.) We also declare an
448	>	* unused "Segment" class that is instantiated in minimal form
449	>	* only when serializing.
450	>	*
451	>	* This file is organized to make things a little easier to follow
452	>	* while reading than they might otherwise: First the main static
453	>	* declarations and utilities, then fields, then main public
454	>	* methods (with a few factorings of multiple public methods into
455	>	* internal ones), then sizing methods, trees, traversers, and
456	>	* bulk operations.
457		*/
458
459		/* ---------------- Constants -------------- */
460
461		/**
462	<	* The default initial capacity for this table,
463	<	* used when not otherwise specified in a constructor.
462	>	* The largest possible table capacity.  This value must be
463	>	* exactly 1<<30 to stay within Java array allocation and indexing
464	>	* bounds for power of two table sizes, and is further required
465	>	* because the top two bits of 32bit hash fields are used for
466	>	* control purposes.
467		*/
468	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
468	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
469
470		/**
471	<	* The default load factor for this table, used when not
472	<	* otherwise specified in a constructor.
471	>	* The default initial table capacity.  Must be a power of 2
472	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
473		*/
474	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
474	>	private static final int DEFAULT_CAPACITY = 16;
475
476		/**
477	<	* The default concurrency level for this table, used when not
478	<	* otherwise specified in a constructor.
477	>	* The largest possible (non-power of two) array size.
478	>	* Needed by toArray and related methods.
479		*/
480	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
480	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
481
482		/**
483	<	* The maximum capacity, used if a higher value is implicitly
484	<	* 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.
483	>	* The default concurrency level for this table. Unused but
484	>	* defined for compatibility with previous versions of this class.
485		*/
486	<	static final int MAXIMUM_CAPACITY = 1 << 30;
486	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
487
488		/**
489	<	* The maximum number of segments to allow; used to bound
490	<	* constructor arguments.
489	>	* The load factor for this table. Overrides of this value in
490	>	* constructors affect only the initial table capacity.  The
491	>	* actual floating point value isn't normally used -- it is
492	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
493	>	* the associated resizing threshold.
494		*/
495	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
495	>	private static final float LOAD_FACTOR = 0.75f;
496
497		/**
498	<	* Number of unsynchronized retries in size and containsValue
499	<	* methods before resorting to locking. This is used to avoid
500	<	* unbounded retries if tables undergo continuous modification
501	<	* which would make it impossible to obtain an accurate result.
498	>	* The bin count threshold for using a tree rather than list for a
499	>	* bin.  Bins are converted to trees when adding an element to a
500	>	* bin with at least this many nodes. The value must be greater
501	>	* than 2, and should be at least 8 to mesh with assumptions in
502	>	* tree removal about conversion back to plain bins upon
503	>	* shrinkage.
504		*/
505	<	static final int RETRIES_BEFORE_LOCK = 2;
123	<
124	<	/* ---------------- Fields -------------- */
505	>	static final int TREEIFY_THRESHOLD = 8;
506
507		/**
508	<	* Mask value for indexing into segments. The upper bits of a
509	<	* key's hash code are used to choose the segment.
508	>	* The bin count threshold for untreeifying a (split) bin during a
509	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
510	>	* most 6 to mesh with shrinkage detection under removal.
511		*/
512	<	final int segmentMask;
512	>	static final int UNTREEIFY_THRESHOLD = 6;
513
514		/**
515	<	* Shift value for indexing within segments.
515	>	* The smallest table capacity for which bins may be treeified.
516	>	* (Otherwise the table is resized if too many nodes in a bin.)
517	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
518	>	* conflicts between resizing and treeification thresholds.
519		*/
520	<	final int segmentShift;
520	>	static final int MIN_TREEIFY_CAPACITY = 64;
521
522		/**
523	<	* The segments, each of which is a specialized hash table
523	>	* Minimum number of rebinnings per transfer step. Ranges are
524	>	* subdivided to allow multiple resizer threads.  This value
525	>	* serves as a lower bound to avoid resizers encountering
526	>	* excessive memory contention.  The value should be at least
527	>	* DEFAULT_CAPACITY.
528		*/
529	<	final Segment<K,V>[] segments;
529	>	private static final int MIN_TRANSFER_STRIDE = 16;
530
531	<	transient Set<K> keySet;
532	<	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
531	>	/*
532	>	* Encodings for Node hash fields. See above for explanation.
533		*/
534	<	final Segment<K,V> segmentFor(int hash) {
535	<	return segments[(hash >>> segmentShift) & segmentMask];
536	<	}
534	>	static final int MOVED     = 0x8fffffff; // (-1) hash for forwarding nodes
535	>	static final int TREEBIN   = 0x80000000; // hash for heads of treea
536	>	static final int RESERVED  = 0x80000001; // hash for transient reservations
537	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
538	>
539	>	/** Number of CPUS, to place bounds on some sizings */
540	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
541	>
542	>	/** For serialization compatibility. */
543	>	private static final ObjectStreamField[] serialPersistentFields = {
544	>	new ObjectStreamField("segments", Segment[].class),
545	>	new ObjectStreamField("segmentMask", Integer.TYPE),
546	>	new ObjectStreamField("segmentShift", Integer.TYPE)
547	>	};
548
549	<	/* ---------------- Inner Classes -------------- */
549	>	/* ---------------- Nodes -------------- */
550
551		/**
552	<	* ConcurrentHashMap list entry. Note that this is never exported
553	<	* out as a user-visible Map.Entry.
554	<	*
555	<	* Because the value field is volatile, not final, it is legal wrt
556	<	* the Java Memory Model for an unsynchronized reader to see null
557	<	* 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.
552	>	* Key-value entry.  This class is never exported out as a
553	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
554	>	* MapEntry below), but can be used for read-only traversals used
555	>	* in bulk tasks.  Subclasses of Node with a negativehash field
556	>	* are special, and contain null keys and values (but are never
557	>	* exported).  Otherwise, keys and vals are never null.
558		*/
559	<	static final class HashEntry<K,V> {
190	<	final K key;
559	>	static class Node<K,V> implements Map.Entry<K,V> {
560		final int hash;
561	<	volatile V value;
562	<	final HashEntry<K,V> next;
561	>	final K key;
562	>	volatile V val;
563	>	Node<K,V> next;
564
565	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
196	<	this.key = key;
565	>	Node(int hash, K key, V val, Node<K,V> next) {
566		this.hash = hash;
567	+	this.key = key;
568	+	this.val = val;
569		this.next = next;
199	–	this.value = value;
570		}
571
572	<	@SuppressWarnings("unchecked")
573	<	static final <K,V> HashEntry<K,V>[] newArray(int i) {
574	<	return new HashEntry[i];
575	<	}
576	<	}
577	<
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));
572	>	public final K getKey()       { return key; }
573	>	public final V getValue()     { return val; }
574	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
575	>	public final String toString(){ return key + "=" + val; }
576	>	public final V setValue(V value) {
577	>	throw new UnsupportedOperationException();
578		}
579
580	<	@SuppressWarnings("unchecked")
581	<	static final <K,V> Segment<K,V>[] newArray(int i) {
582	<	return new Segment[i];
580	>	public final boolean equals(Object o) {
581	>	Object k, v, u; Map.Entry<?,?> e;
582	>	return ((o instanceof Map.Entry) &&
583	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
584	>	(v = e.getValue()) != null &&
585	>	(k == key || k.equals(key)) &&
586	>	(v == (u = val) || v.equals(u)));
587		}
588
589		/**
590	<	* Sets table to new HashEntry array.
300	<	* Call only while holding lock or in constructor.
590	>	* Virtualized support for map.get(); overridden in subclasses.
591		*/
592	<	void setTable(HashEntry<K,V>[] newTable) {
593	<	threshold = (int)(newTable.length * loadFactor);
594	<	table = newTable;
595	<	}
596	<
597	<	/**
598	<	* Returns properly casted first entry of bin for given hash.
599	<	*/
600	<	HashEntry<K,V> getFirst(int hash) {
311	<	HashEntry<K,V>[] tab = table;
312	<	return tab[hash & (tab.length - 1)];
313	<	}
314	<
315	<	/**
316	<	* 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.
321	<	*/
322	<	V readValueUnderLock(HashEntry<K,V> e) {
323	<	lock();
324	<	try {
325	<	return e.value;
326	<	} finally {
327	<	unlock();
592	>	Node<K,V> find(int h, Object k) {
593	>	Node<K,V> e = this;
594	>	if (k != null) {
595	>	do {
596	>	K ek;
597	>	if (e.hash == h &&
598	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
599	>	return e;
600	>	} while ((e = e.next) != null);
601		}
602	+	return null;
603		}
604	+	}
605
606	<	/* Specialized implementations of map methods */
606	>	/* ---------------- Static utilities -------------- */
607
608	<	V get(Object key, int hash) {
609	<	if (count != 0) { // read-volatile
610	<	HashEntry<K,V> e = getFirst(hash);
611	<	while (e != null) {
612	<	if (e.hash == hash && key.equals(e.key)) {
613	<	V v = e.value;
614	<	if (v != null)
615	<	return v;
616	<	return readValueUnderLock(e); // recheck
617	<	}
618	<	e = e.next;
619	<	}
620	<	}
621	<	return null;
622	<	}
608	>	/**
609	>	* Spreads (XORs) higher bits of hash to lower and also forces top
610	>	* bit to 0. Because the table uses power-of-two masking, sets of
611	>	* hashes that vary only in bits above the current mask will
612	>	* always collide. (Among known examples are sets of Float keys
613	>	* holding consecutive whole numbers in small tables.)  So we
614	>	* apply a transform that spreads the impact of higher bits
615	>	* downward. There is a tradeoff between speed, utility, and
616	>	* quality of bit-spreading. Because many common sets of hashes
617	>	* are already reasonably distributed (so don't benefit from
618	>	* spreading), and because we use trees to handle large sets of
619	>	* collisions in bins, we just XOR some shifted bits in the
620	>	* cheapest possible way to reduce systematic lossage, as well as
621	>	* to incorporate impact of the highest bits that would otherwise
622	>	* never be used in index calculations because of table bounds.
623	>	*/
624	>	static final int spread(int h) {
625	>	return (h ^ (h >>> 16)) & HASH_BITS;
626	>	}
627
628	<	boolean containsKey(Object key, int hash) {
629	<	if (count != 0) { // read-volatile
630	<	HashEntry<K,V> e = getFirst(hash);
631	<	while (e != null) {
632	<	if (e.hash == hash && key.equals(e.key))
633	<	return true;
634	<	e = e.next;
635	<	}
636	<	}
637	<	return false;
638	<	}
628	>	/**
629	>	* Returns a power of two table size for the given desired capacity.
630	>	* See Hackers Delight, sec 3.2
631	>	*/
632	>	private static final int tableSizeFor(int c) {
633	>	int n = c - 1;
634	>	n |= n >>> 1;
635	>	n |= n >>> 2;
636	>	n |= n >>> 4;
637	>	n |= n >>> 8;
638	>	n |= n >>> 16;
639	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
640	>	}
641
642	<	boolean containsValue(Object value) {
643	<	if (count != 0) { // read-volatile
644	<	HashEntry<K,V>[] tab = table;
645	<	int len = tab.length;
646	<	for (int i = 0 ; i < len; i++) {
647	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
648	<	V v = e.value;
649	<	if (v == null) // recheck
650	<	v = readValueUnderLock(e);
651	<	if (value.equals(v))
652	<	return true;
653	<	}
642	>	/**
643	>	* Returns x's Class if it is of the form "class C implements
644	>	* Comparable<C>", else null.
645	>	*/
646	>	static Class<?> comparableClassFor(Object x) {
647	>	if (x instanceof Comparable) {
648	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
649	>	if ((c = x.getClass()) == String.class) // bypass checks
650	>	return c;
651	>	if ((ts = c.getGenericInterfaces()) != null) {
652	>	for (int i = 0; i < ts.length; ++i) {
653	>	if (((t = ts[i]) instanceof ParameterizedType) &&
654	>	((p = (ParameterizedType)t).getRawType() ==
655	>	Comparable.class) &&
656	>	(as = p.getActualTypeArguments()) != null &&
657	>	as.length == 1 && as[0] == c) // type arg is c
658	>	return c;
659		}
660		}
375	–	return false;
661		}
662	+	return null;
663	+	}
664
665	<	boolean replace(K key, int hash, V oldValue, V newValue) {
666	<	lock();
667	<	try {
668	<	HashEntry<K,V> e = getFirst(hash);
669	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
670	<	e = e.next;
671	<
672	<	boolean replaced = false;
673	<	if (e != null && oldValue.equals(e.value)) {
387	<	replaced = true;
388	<	e.value = newValue;
389	<	}
390	<	return replaced;
391	<	} finally {
392	<	unlock();
393	<	}
394	<	}
665	>	/**
666	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
667	>	* class), else 0.
668	>	*/
669	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
670	>	static int compareComparables(Class<?> kc, Object k, Object x) {
671	>	return (x == null || x.getClass() != kc ? 0 :
672	>	((Comparable)k).compareTo(x));
673	>	}
674
675	<	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	<	}
675	>	/* ---------------- Table element access -------------- */
676
677	+	/*
678	+	* Volatile access methods are used for table elements as well as
679	+	* elements of in-progress next table while resizing.  All uses of
680	+	* the tab arguments must be null checked by callers.  All callers
681	+	* also paranoically precheck that tab's length is not zero (or an
682	+	* equivalent check), thus ensuring that any index argument taking
683	+	* the form of a hash value anded with (length - 1) is a valid
684	+	* index.  Note that, to be correct wrt arbitrary concurrency
685	+	* errors by users, these checks must operate on local variables,
686	+	* which accounts for some odd-looking inline assignments below.
687	+	* Note that calls to setTabAt always occur within locked regions,
688	+	* and so do not need full volatile semantics, but still require
689	+	* ordering to maintain concurrent readability.
690	+	*/
691	+
692	+	@SuppressWarnings("unchecked")
693	+	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
694	+	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
695	+	}
696
697	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
698	<	lock();
699	<	try {
700	<	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	<	}
697	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
698	>	Node<K,V> c, Node<K,V> v) {
699	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
700	>	}
701
702	<	void rehash() {
703	<	HashEntry<K,V>[] oldTable = table;
704	<	int oldCapacity = oldTable.length;
449	<	if (oldCapacity >= MAXIMUM_CAPACITY)
450	<	return;
702	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
703	>	U.putOrderedObject(tab, ((long)i << ASHIFT) + ABASE, v);
704	>	}
705
706	<	/*
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;
706	>	/* ---------------- Fields -------------- */
707
708	<	else {
709	<	// Reuse trailing consecutive sequence at same slot
710	<	HashEntry<K,V> lastRun = e;
711	<	int lastIdx = idx;
712	<	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;
708	>	/**
709	>	* The array of bins. Lazily initialized upon first insertion.
710	>	* Size is always a power of two. Accessed directly by iterators.
711	>	*/
712	>	transient volatile Node<K,V>[] table;
713
714	<	// Clone all remaining nodes
715	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
716	<	int k = p.hash & sizeMask;
717	<	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	<	}
714	>	/**
715	>	* The next table to use; non-null only while resizing.
716	>	*/
717	>	private transient volatile Node<K,V>[] nextTable;
718
719	<	/**
720	<	* Remove; match on key only if value null, else match both.
721	<	*/
722	<	V remove(Object key, int hash, Object value) {
723	<	lock();
724	<	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	<	}
719	>	/**
720	>	* Base counter value, used mainly when there is no contention,
721	>	* but also as a fallback during table initialization
722	>	* races. Updated via CAS.
723	>	*/
724	>	private transient volatile long baseCount;
725
726	<	void clear() {
727	<	if (count != 0) {
728	<	lock();
729	<	try {
730	<	HashEntry<K,V>[] tab = table;
731	<	for (int i = 0; i < tab.length ; i++)
732	<	tab[i] = null;
733	<	++modCount;
734	<	count = 0; // write-volatile
556	<	} finally {
557	<	unlock();
558	<	}
559	<	}
560	<	}
561	<	}
726	>	/**
727	>	* Table initialization and resizing control.  When negative, the
728	>	* table is being initialized or resized: -1 for initialization,
729	>	* else -(1 + the number of active resizing threads).  Otherwise,
730	>	* when table is null, holds the initial table size to use upon
731	>	* creation, or 0 for default. After initialization, holds the
732	>	* next element count value upon which to resize the table.
733	>	*/
734	>	private transient volatile int sizeCtl;
735
736	+	/**
737	+	* The next table index (plus one) to split while resizing.
738	+	*/
739	+	private transient volatile int transferIndex;
740
741	+	/**
742	+	* The least available table index to split while resizing.
743	+	*/
744	+	private transient volatile int transferOrigin;
745
746	<	/* ---------------- Public operations -------------- */
746	>	/**
747	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
748	>	*/
749	>	private transient volatile int cellsBusy;
750
751		/**
752	<	* 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.
752	>	* Table of counter cells. When non-null, size is a power of 2.
753		*/
754	<	public ConcurrentHashMap(int initialCapacity,
584	<	float loadFactor, int concurrencyLevel) {
585	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
586	<	throw new IllegalArgumentException();
754	>	private transient volatile CounterCell[] counterCells;
755
756	<	if (concurrencyLevel > MAX_SEGMENTS)
757	<	concurrencyLevel = MAX_SEGMENTS;
756	>	// views
757	>	private transient KeySetView<K,V> keySet;
758	>	private transient ValuesView<K,V> values;
759	>	private transient EntrySetView<K,V> entrySet;
760
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;
761
762	<	for (int i = 0; i < this.segments.length; ++i)
612	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
613	<	}
762	>	/* ---------------- Public operations -------------- */
763
764		/**
765	<	* 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
765	>	* Creates a new, empty map with the default initial table size (16).
766		*/
767	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
630	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
767	>	public ConcurrentHashMap() {
768		}
769
770		/**
771	<	* Creates a new, empty map with the specified initial capacity,
772	<	* and with default load factor (0.75) and concurrencyLevel (16).
771	>	* Creates a new, empty map with an initial table size
772	>	* accommodating the specified number of elements without the need
773	>	* to dynamically resize.
774		*
775	<	* @param initialCapacity the initial capacity. The implementation
776	<	* performs internal sizing to accommodate this many elements.
775	>	* @param initialCapacity The implementation performs internal
776	>	* sizing to accommodate this many elements.
777		* @throws IllegalArgumentException if the initial capacity of
778	<	* elements is negative.
778	>	* elements is negative
779		*/
780		public ConcurrentHashMap(int initialCapacity) {
781	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
782	<	}
783	<
784	<	/**
785	<	* Creates a new, empty map with a default initial capacity (16),
786	<	* load factor (0.75) and concurrencyLevel (16).
649	<	*/
650	<	public ConcurrentHashMap() {
651	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
781	>	if (initialCapacity < 0)
782	>	throw new IllegalArgumentException();
783	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
784	>	MAXIMUM_CAPACITY :
785	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
786	>	this.sizeCtl = cap;
787		}
788
789		/**
790		* 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).
791		*
792		* @param m the map
793		*/
794		public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
795	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
664	<	DEFAULT_INITIAL_CAPACITY),
665	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
795	>	this.sizeCtl = DEFAULT_CAPACITY;
796		putAll(m);
797		}
798
799		/**
800	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
800	>	* Creates a new, empty map with an initial table size based on
801	>	* the given number of elements ({@code initialCapacity}) and
802	>	* initial table density ({@code loadFactor}).
803		*
804	<	* @return <tt>true</tt> if this map contains no key-value mappings
804	>	* @param initialCapacity the initial capacity. The implementation
805	>	* performs internal sizing to accommodate this many elements,
806	>	* given the specified load factor.
807	>	* @param loadFactor the load factor (table density) for
808	>	* establishing the initial table size
809	>	* @throws IllegalArgumentException if the initial capacity of
810	>	* elements is negative or the load factor is nonpositive
811	>	*
812	>	* @since 1.6
813		*/
814	<	public boolean isEmpty() {
815	<	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;
814	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
815	>	this(initialCapacity, loadFactor, 1);
816		}
817
818		/**
819	<	* Returns the number of key-value mappings in this map.  If the
820	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
821	<	* <tt>Integer.MAX_VALUE</tt>.
819	>	* Creates a new, empty map with an initial table size based on
820	>	* the given number of elements ({@code initialCapacity}), table
821	>	* density ({@code loadFactor}), and number of concurrently
822	>	* updating threads ({@code concurrencyLevel}).
823		*
824	<	* @return the number of key-value mappings in this map
824	>	* @param initialCapacity the initial capacity. The implementation
825	>	* performs internal sizing to accommodate this many elements,
826	>	* given the specified load factor.
827	>	* @param loadFactor the load factor (table density) for
828	>	* establishing the initial table size
829	>	* @param concurrencyLevel the estimated number of concurrently
830	>	* updating threads. The implementation may use this value as
831	>	* a sizing hint.
832	>	* @throws IllegalArgumentException if the initial capacity is
833	>	* negative or the load factor or concurrencyLevel are
834	>	* nonpositive
835	>	*/
836	>	public ConcurrentHashMap(int initialCapacity,
837	>	float loadFactor, int concurrencyLevel) {
838	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
839	>	throw new IllegalArgumentException();
840	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
841	>	initialCapacity = concurrencyLevel;   // as estimated threads
842	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
843	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
844	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
845	>	this.sizeCtl = cap;
846	>	}
847	>
848	>	// Original (since JDK1.2) Map methods
849	>
850	>	/**
851	>	* {@inheritDoc}
852		*/
853		public int size() {
854	<	final Segment<K,V>[] segments = this.segments;
855	<	long sum = 0;
856	<	long check = 0;
857	<	int[] mc = new int[segments.length];
858	<	// Try a few times to get accurate count. On failure due to
859	<	// continuous async changes in table, resort to locking.
860	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
861	<	check = 0;
862	<	sum = 0;
863	<	int mcsum = 0;
864	<	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;
854	>	long n = sumCount();
855	>	return ((n < 0L) ? 0 :
856	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
857	>	(int)n);
858	>	}
859	>
860	>	/**
861	>	* {@inheritDoc}
862	>	*/
863	>	public boolean isEmpty() {
864	>	return sumCount() <= 0L; // ignore transient negative values
865		}
866
867		/**
#	Line 764 | Line 876 | public class ConcurrentHashMap<K, V> ext
876		* @throws NullPointerException if the specified key is null
877		*/
878		public V get(Object key) {
879	<	int hash = hash(key.hashCode());
880	<	return segmentFor(hash).get(key, hash);
879	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
880	>	int h = spread(key.hashCode());
881	>	if ((tab = table) != null && (n = tab.length) > 0 &&
882	>	(e = tabAt(tab, (n - 1) & h)) != null) {
883	>	if ((eh = e.hash) == h) {
884	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
885	>	return e.val;
886	>	}
887	>	else if (eh < 0)
888	>	return (p = e.find(h, key)) != null ? p.val : null;
889	>	while ((e = e.next) != null) {
890	>	if (e.hash == h &&
891	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
892	>	return e.val;
893	>	}
894	>	}
895	>	return null;
896		}
897
898		/**
899		* Tests if the specified object is a key in this table.
900		*
901	<	* @param  key   possible key
902	<	* @return <tt>true</tt> if and only if the specified object
901	>	* @param  key possible key
902	>	* @return {@code true} if and only if the specified object
903		*         is a key in this table, as determined by the
904	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
904	>	*         {@code equals} method; {@code false} otherwise
905		* @throws NullPointerException if the specified key is null
906		*/
907		public boolean containsKey(Object key) {
908	<	int hash = hash(key.hashCode());
782	<	return segmentFor(hash).containsKey(key, hash);
908	>	return get(key) != null;
909		}
910
911		/**
912	<	* Returns <tt>true</tt> if this map maps one or more keys to the
913	<	* specified value. Note: This method requires a full internal
914	<	* traversal of the hash table, and so is much slower than
789	<	* method <tt>containsKey</tt>.
912	>	* Returns {@code true} if this map maps one or more keys to the
913	>	* specified value. Note: This method may require a full traversal
914	>	* of the map, and is much slower than method {@code containsKey}.
915		*
916		* @param value value whose presence in this map is to be tested
917	<	* @return <tt>true</tt> if this map maps one or more keys to the
917	>	* @return {@code true} if this map maps one or more keys to the
918		*         specified value
919		* @throws NullPointerException if the specified value is null
920		*/
921		public boolean containsValue(Object value) {
922		if (value == null)
923		throw new NullPointerException();
924	<
925	<	// See explanation of modCount use above
926	<
927	<	final Segment<K,V>[] segments = this.segments;
928	<	int[] mc = new int[segments.length];
929	<
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))
924	>	Node<K,V>[] t;
925	>	if ((t = table) != null) {
926	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
927	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
928	>	V v;
929	>	if ((v = p.val) == value || (v != null && value.equals(v)))
930		return true;
931		}
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;
827	–	}
828	–	// 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();
932		}
933	<	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);
933	>	return false;
934		}
935
936		/**
937		* Maps the specified key to the specified value in this table.
938		* Neither the key nor the value can be null.
939		*
940	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
940	>	* <p>The value can be retrieved by calling the {@code get} method
941		* with a key that is equal to the original key.
942		*
943		* @param key key with which the specified value is to be associated
944		* @param value value to be associated with the specified key
945	<	* @return the previous value associated with <tt>key</tt>, or
946	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
945	>	* @return the previous value associated with {@code key}, or
946	>	*         {@code null} if there was no mapping for {@code key}
947		* @throws NullPointerException if the specified key or value is null
948		*/
949		public V put(K key, V value) {
950	<	if (value == null)
880	<	throw new NullPointerException();
881	<	int hash = hash(key.hashCode());
882	<	return segmentFor(hash).put(key, hash, value, false);
950	>	return putVal(key, value, false);
951		}
952
953	<	/**
954	<	* {@inheritDoc}
955	<	*
956	<	* @return the previous value associated with the specified key,
957	<	*         or <tt>null</tt> if there was no mapping for the key
958	<	* @throws NullPointerException if the specified key or value is null
959	<	*/
960	<	public V putIfAbsent(K key, V value) {
961	<	if (value == null)
962	<	throw new NullPointerException();
963	<	int hash = hash(key.hashCode());
964	<	return segmentFor(hash).put(key, hash, value, true);
953	>	/** Implementation for put and putIfAbsent */
954	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
955	>	if (key == null || value == null) throw new NullPointerException();
956	>	int hash = spread(key.hashCode());
957	>	int binCount = 0;
958	>	for (Node<K,V>[] tab = table;;) {
959	>	Node<K,V> f; int n, i, fh;
960	>	if (tab == null || (n = tab.length) == 0)
961	>	tab = initTable();
962	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
963	>	if (casTabAt(tab, i, null,
964	>	new Node<K,V>(hash, key, value, null)))
965	>	break;                   // no lock when adding to empty bin
966	>	}
967	>	else if ((fh = f.hash) == MOVED)
968	>	tab = helpTransfer(tab, f);
969	>	else {
970	>	V oldVal = null;
971	>	synchronized (f) {
972	>	if (tabAt(tab, i) == f) {
973	>	if (fh >= 0) {
974	>	binCount = 1;
975	>	for (Node<K,V> e = f;; ++binCount) {
976	>	K ek;
977	>	if (e.hash == hash &&
978	>	((ek = e.key) == key ||
979	>	(ek != null && key.equals(ek)))) {
980	>	oldVal = e.val;
981	>	if (!onlyIfAbsent)
982	>	e.val = value;
983	>	break;
984	>	}
985	>	Node<K,V> pred = e;
986	>	if ((e = e.next) == null) {
987	>	pred.next = new Node<K,V>(hash, key,
988	>	value, null);
989	>	break;
990	>	}
991	>	}
992	>	}
993	>	else if (f instanceof TreeBin) {
994	>	Node<K,V> p;
995	>	binCount = 2;
996	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
997	>	value)) != null) {
998	>	oldVal = p.val;
999	>	if (!onlyIfAbsent)
1000	>	p.val = value;
1001	>	}
1002	>	}
1003	>	}
1004	>	}
1005	>	if (binCount != 0) {
1006	>	if (binCount >= TREEIFY_THRESHOLD)
1007	>	treeifyBin(tab, i);
1008	>	if (oldVal != null)
1009	>	return oldVal;
1010	>	break;
1011	>	}
1012	>	}
1013	>	}
1014	>	addCount(1L, binCount);
1015	>	return null;
1016		}
1017
1018		/**
#	Line 904 | Line 1023 | public class ConcurrentHashMap<K, V> ext
1023		* @param m mappings to be stored in this map
1024		*/
1025		public void putAll(Map<? extends K, ? extends V> m) {
1026	+	tryPresize(m.size());
1027		for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1028	<	put(e.getKey(), e.getValue());
1028	>	putVal(e.getKey(), e.getValue(), false);
1029		}
1030
1031		/**
#	Line 913 | Line 1033 | public class ConcurrentHashMap<K, V> ext
1033		* This method does nothing if the key is not in the map.
1034		*
1035		* @param  key the key that needs to be removed
1036	<	* @return the previous value associated with <tt>key</tt>, or
1037	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1036	>	* @return the previous value associated with {@code key}, or
1037	>	*         {@code null} if there was no mapping for {@code key}
1038		* @throws NullPointerException if the specified key is null
1039		*/
1040		public V remove(Object key) {
1041	<	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);
1041	>	return replaceNode(key, null, null);
1042		}
1043
1044		/**
1045	<	* {@inheritDoc}
1046	<	*
1047	<	* @return the previous value associated with the specified key,
1048	<	*         or <tt>null</tt> if there was no mapping for the key
1049	<	* @throws NullPointerException if the specified key or value is null
1050	<	*/
1051	<	public V replace(K key, V value) {
1052	<	if (value == null)
1053	<	throw new NullPointerException();
1054	<	int hash = hash(key.hashCode());
1055	<	return segmentFor(hash).replace(key, hash, value);
1045	>	* Implementation for the four public remove/replace methods:
1046	>	* Replaces node value with v, conditional upon match of cv if
1047	>	* non-null.  If resulting value is null, delete.
1048	>	*/
1049	>	final V replaceNode(Object key, V value, Object cv) {
1050	>	int hash = spread(key.hashCode());
1051	>	for (Node<K,V>[] tab = table;;) {
1052	>	Node<K,V> f; int n, i, fh;
1053	>	if (tab == null || (n = tab.length) == 0 ||
1054	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1055	>	break;
1056	>	else if ((fh = f.hash) == MOVED)
1057	>	tab = helpTransfer(tab, f);
1058	>	else {
1059	>	V oldVal = null;
1060	>	boolean validated = false;
1061	>	synchronized (f) {
1062	>	if (tabAt(tab, i) == f) {
1063	>	if (fh >= 0) {
1064	>	validated = true;
1065	>	for (Node<K,V> e = f, pred = null;;) {
1066	>	K ek;
1067	>	if (e.hash == hash &&
1068	>	((ek = e.key) == key ||
1069	>	(ek != null && key.equals(ek)))) {
1070	>	V ev = e.val;
1071	>	if (cv == null || cv == ev ||
1072	>	(ev != null && cv.equals(ev))) {
1073	>	oldVal = ev;
1074	>	if (value != null)
1075	>	e.val = value;
1076	>	else if (pred != null)
1077	>	pred.next = e.next;
1078	>	else
1079	>	setTabAt(tab, i, e.next);
1080	>	}
1081	>	break;
1082	>	}
1083	>	pred = e;
1084	>	if ((e = e.next) == null)
1085	>	break;
1086	>	}
1087	>	}
1088	>	else if (f instanceof TreeBin) {
1089	>	validated = true;
1090	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1091	>	TreeNode<K,V> r, p;
1092	>	if ((r = t.root) != null &&
1093	>	(p = r.findTreeNode(hash, key, null)) != null) {
1094	>	V pv = p.val;
1095	>	if (cv == null || cv == pv ||
1096	>	(pv != null && cv.equals(pv))) {
1097	>	oldVal = pv;
1098	>	if (value != null)
1099	>	p.val = value;
1100	>	else if (t.removeTreeNode(p))
1101	>	setTabAt(tab, i, untreeify(t.first));
1102	>	}
1103	>	}
1104	>	}
1105	>	}
1106	>	}
1107	>	if (validated) {
1108	>	if (oldVal != null) {
1109	>	if (value == null)
1110	>	addCount(-1L, -1);
1111	>	return oldVal;
1112	>	}
1113	>	break;
1114	>	}
1115	>	}
1116	>	}
1117	>	return null;
1118		}
1119
1120		/**
1121		* Removes all of the mappings from this map.
1122		*/
1123		public void clear() {
1124	<	for (int i = 0; i < segments.length; ++i)
1125	<	segments[i].clear();
1124	>	long delta = 0L; // negative number of deletions
1125	>	int i = 0;
1126	>	Node<K,V>[] tab = table;
1127	>	while (tab != null && i < tab.length) {
1128	>	int fh;
1129	>	Node<K,V> f = tabAt(tab, i);
1130	>	if (f == null)
1131	>	++i;
1132	>	else if ((fh = f.hash) == MOVED) {
1133	>	tab = helpTransfer(tab, f);
1134	>	i = 0; // restart
1135	>	}
1136	>	else {
1137	>	synchronized (f) {
1138	>	if (tabAt(tab, i) == f) {
1139	>	Node<K,V> p = (fh >= 0 ? f :
1140	>	(f instanceof TreeBin) ?
1141	>	((TreeBin<K,V>)f).first : null);
1142	>	while (p != null) {
1143	>	--delta;
1144	>	p = p.next;
1145	>	}
1146	>	setTabAt(tab, i++, null);
1147	>	}
1148	>	}
1149	>	}
1150	>	}
1151	>	if (delta != 0L)
1152	>	addCount(delta, -1);
1153		}
1154
1155		/**
1156		* Returns a {@link Set} view of the keys contained in this map.
1157		* The set is backed by the map, so changes to the map are
1158	<	* reflected in the set, and vice-versa.  The set supports element
1158	>	* reflected in the set, and vice-versa. The set supports element
1159		* removal, which removes the corresponding mapping from this map,
1160	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1161	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1162	<	* operations.  It does not support the <tt>add</tt> or
1163	<	* <tt>addAll</tt> operations.
1160	>	* via the {@code Iterator.remove}, {@code Set.remove},
1161	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1162	>	* operations.  It does not support the {@code add} or
1163	>	* {@code addAll} operations.
1164		*
1165	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1165	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1166		* that will never throw {@link ConcurrentModificationException},
1167		* and guarantees to traverse elements as they existed upon
1168		* construction of the iterator, and may (but is not guaranteed to)
1169		* reflect any modifications subsequent to construction.
1170	+	*
1171	+	* @return the set view
1172		*/
1173	<	public Set<K> keySet() {
1174	<	Set<K> ks = keySet;
1175	<	return (ks != null) ? ks : (keySet = new KeySet());
1173	>	public KeySetView<K,V> keySet() {
1174	>	KeySetView<K,V> ks;
1175	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1176		}
1177
1178		/**
#	Line 994 | Line 1180 | public class ConcurrentHashMap<K, V> ext
1180		* The collection is backed by the map, so changes to the map are
1181		* reflected in the collection, and vice-versa.  The collection
1182		* supports element removal, which removes the corresponding
1183	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1184	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1185	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1186	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1183	>	* mapping from this map, via the {@code Iterator.remove},
1184	>	* {@code Collection.remove}, {@code removeAll},
1185	>	* {@code retainAll}, and {@code clear} operations.  It does not
1186	>	* support the {@code add} or {@code addAll} operations.
1187		*
1188	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1188	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1189		* that will never throw {@link ConcurrentModificationException},
1190		* and guarantees to traverse elements as they existed upon
1191		* construction of the iterator, and may (but is not guaranteed to)
1192		* reflect any modifications subsequent to construction.
1193	+	*
1194	+	* @return the collection view
1195		*/
1196		public Collection<V> values() {
1197	<	Collection<V> vs = values;
1198	<	return (vs != null) ? vs : (values = new Values());
1197	>	ValuesView<K,V> vs;
1198	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1199		}
1200
1201		/**
#	Line 1015 | Line 1203 | public class ConcurrentHashMap<K, V> ext
1203		* The set is backed by the map, so changes to the map are
1204		* reflected in the set, and vice-versa.  The set supports element
1205		* removal, which removes the corresponding mapping from the map,
1206	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1207	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1208	<	* operations.  It does not support the <tt>add</tt> or
1021	<	* <tt>addAll</tt> operations.
1206	>	* via the {@code Iterator.remove}, {@code Set.remove},
1207	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1208	>	* operations.
1209		*
1210	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1210	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1211		* that will never throw {@link ConcurrentModificationException},
1212		* and guarantees to traverse elements as they existed upon
1213		* construction of the iterator, and may (but is not guaranteed to)
1214		* reflect any modifications subsequent to construction.
1215	+	*
1216	+	* @return the set view
1217		*/
1218		public Set<Map.Entry<K,V>> entrySet() {
1219	<	Set<Map.Entry<K,V>> es = entrySet;
1220	<	return (es != null) ? es : (entrySet = new EntrySet());
1219	>	EntrySetView<K,V> es;
1220	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1221	>	}
1222	>
1223	>	/**
1224	>	* Returns the hash code value for this {@link Map}, i.e.,
1225	>	* the sum of, for each key-value pair in the map,
1226	>	* {@code key.hashCode() ^ value.hashCode()}.
1227	>	*
1228	>	* @return the hash code value for this map
1229	>	*/
1230	>	public int hashCode() {
1231	>	int h = 0;
1232	>	Node<K,V>[] t;
1233	>	if ((t = table) != null) {
1234	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1235	>	for (Node<K,V> p; (p = it.advance()) != null; )
1236	>	h += p.key.hashCode() ^ p.val.hashCode();
1237	>	}
1238	>	return h;
1239	>	}
1240	>
1241	>	/**
1242	>	* Returns a string representation of this map.  The string
1243	>	* representation consists of a list of key-value mappings (in no
1244	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1245	>	* mappings are separated by the characters {@code ", "} (comma
1246	>	* and space).  Each key-value mapping is rendered as the key
1247	>	* followed by an equals sign ("{@code =}") followed by the
1248	>	* associated value.
1249	>	*
1250	>	* @return a string representation of this map
1251	>	*/
1252	>	public String toString() {
1253	>	Node<K,V>[] t;
1254	>	int f = (t = table) == null ? 0 : t.length;
1255	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1256	>	StringBuilder sb = new StringBuilder();
1257	>	sb.append('{');
1258	>	Node<K,V> p;
1259	>	if ((p = it.advance()) != null) {
1260	>	for (;;) {
1261	>	K k = p.key;
1262	>	V v = p.val;
1263	>	sb.append(k == this ? "(this Map)" : k);
1264	>	sb.append('=');
1265	>	sb.append(v == this ? "(this Map)" : v);
1266	>	if ((p = it.advance()) == null)
1267	>	break;
1268	>	sb.append(',').append(' ');
1269	>	}
1270	>	}
1271	>	return sb.append('}').toString();
1272	>	}
1273	>
1274	>	/**
1275	>	* Compares the specified object with this map for equality.
1276	>	* Returns {@code true} if the given object is a map with the same
1277	>	* mappings as this map.  This operation may return misleading
1278	>	* results if either map is concurrently modified during execution
1279	>	* of this method.
1280	>	*
1281	>	* @param o object to be compared for equality with this map
1282	>	* @return {@code true} if the specified object is equal to this map
1283	>	*/
1284	>	public boolean equals(Object o) {
1285	>	if (o != this) {
1286	>	if (!(o instanceof Map))
1287	>	return false;
1288	>	Map<?,?> m = (Map<?,?>) o;
1289	>	Node<K,V>[] t;
1290	>	int f = (t = table) == null ? 0 : t.length;
1291	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1292	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1293	>	V val = p.val;
1294	>	Object v = m.get(p.key);
1295	>	if (v == null || (v != val && !v.equals(val)))
1296	>	return false;
1297	>	}
1298	>	for (Map.Entry<?,?> e : m.entrySet()) {
1299	>	Object mk, mv, v;
1300	>	if ((mk = e.getKey()) == null ||
1301	>	(mv = e.getValue()) == null ||
1302	>	(v = get(mk)) == null ||
1303	>	(mv != v && !mv.equals(v)))
1304	>	return false;
1305	>	}
1306	>	}
1307	>	return true;
1308	>	}
1309	>
1310	>	/**
1311	>	* Stripped-down version of helper class used in previous version,
1312	>	* declared for the sake of serialization compatibility
1313	>	*/
1314	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1315	>	private static final long serialVersionUID = 2249069246763182397L;
1316	>	final float loadFactor;
1317	>	Segment(float lf) { this.loadFactor = lf; }
1318	>	}
1319	>
1320	>	/**
1321	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1322	>	* stream (i.e., serializes it).
1323	>	* @param s the stream
1324	>	* @serialData
1325	>	* the key (Object) and value (Object)
1326	>	* for each key-value mapping, followed by a null pair.
1327	>	* The key-value mappings are emitted in no particular order.
1328	>	*/
1329	>	private void writeObject(java.io.ObjectOutputStream s)
1330	>	throws java.io.IOException {
1331	>	// For serialization compatibility
1332	>	// Emulate segment calculation from previous version of this class
1333	>	int sshift = 0;
1334	>	int ssize = 1;
1335	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1336	>	++sshift;
1337	>	ssize <<= 1;
1338	>	}
1339	>	int segmentShift = 32 - sshift;
1340	>	int segmentMask = ssize - 1;
1341	>	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1342	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1343	>	for (int i = 0; i < segments.length; ++i)
1344	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1345	>	s.putFields().put("segments", segments);
1346	>	s.putFields().put("segmentShift", segmentShift);
1347	>	s.putFields().put("segmentMask", segmentMask);
1348	>	s.writeFields();
1349	>
1350	>	Node<K,V>[] t;
1351	>	if ((t = table) != null) {
1352	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1353	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1354	>	s.writeObject(p.key);
1355	>	s.writeObject(p.val);
1356	>	}
1357	>	}
1358	>	s.writeObject(null);
1359	>	s.writeObject(null);
1360	>	segments = null; // throw away
1361	>	}
1362	>
1363	>	/**
1364	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1365	>	* @param s the stream
1366	>	*/
1367	>	private void readObject(java.io.ObjectInputStream s)
1368	>	throws java.io.IOException, ClassNotFoundException {
1369	>	/*
1370	>	* To improve performance in typical cases, we create nodes
1371	>	* while reading, then place in table once size is known.
1372	>	* However, we must also validate uniqueness and deal with
1373	>	* overpopulated bins while doing so, which requires
1374	>	* specialized versions of putVal mechanics.
1375	>	*/
1376	>	sizeCtl = -1; // force exclusion for table construction
1377	>	s.defaultReadObject();
1378	>	long size = 0L;
1379	>	Node<K,V> p = null;
1380	>	for (;;) {
1381	>	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1382	>	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1383	>	if (k != null && v != null) {
1384	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1385	>	++size;
1386	>	}
1387	>	else
1388	>	break;
1389	>	}
1390	>	if (size == 0L)
1391	>	sizeCtl = 0;
1392	>	else {
1393	>	int n;
1394	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1395	>	n = MAXIMUM_CAPACITY;
1396	>	else {
1397	>	int sz = (int)size;
1398	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1399	>	}
1400	>	@SuppressWarnings({"rawtypes","unchecked"})
1401	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1402	>	int mask = n - 1;
1403	>	long added = 0L;
1404	>	while (p != null) {
1405	>	boolean insertAtFront;
1406	>	Node<K,V> next = p.next, first;
1407	>	int h = p.hash, j = h & mask;
1408	>	if ((first = tabAt(tab, j)) == null)
1409	>	insertAtFront = true;
1410	>	else {
1411	>	K k = p.key;
1412	>	if (first.hash < 0) {
1413	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1414	>	if (t.putTreeVal(h, k, p.val) == null)
1415	>	++added;
1416	>	insertAtFront = false;
1417	>	}
1418	>	else {
1419	>	int binCount = 0;
1420	>	insertAtFront = true;
1421	>	Node<K,V> q; K qk;
1422	>	for (q = first; q != null; q = q.next) {
1423	>	if (q.hash == h &&
1424	>	((qk = q.key) == k ||
1425	>	(qk != null && k.equals(qk)))) {
1426	>	insertAtFront = false;
1427	>	break;
1428	>	}
1429	>	++binCount;
1430	>	}
1431	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1432	>	insertAtFront = false;
1433	>	++added;
1434	>	p.next = first;
1435	>	TreeNode<K,V> hd = null, tl = null;
1436	>	for (q = p; q != null; q = q.next) {
1437	>	TreeNode<K,V> t = new TreeNode<K,V>
1438	>	(q.hash, q.key, q.val, null, null);
1439	>	if ((t.prev = tl) == null)
1440	>	hd = t;
1441	>	else
1442	>	tl.next = t;
1443	>	tl = t;
1444	>	}
1445	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1446	>	}
1447	>	}
1448	>	}
1449	>	if (insertAtFront) {
1450	>	++added;
1451	>	p.next = first;
1452	>	setTabAt(tab, j, p);
1453	>	}
1454	>	p = next;
1455	>	}
1456	>	table = tab;
1457	>	sizeCtl = n - (n >>> 2);
1458	>	baseCount = added;
1459	>	}
1460	>	}
1461	>
1462	>	// ConcurrentMap methods
1463	>
1464	>	/**
1465	>	* {@inheritDoc}
1466	>	*
1467	>	* @return the previous value associated with the specified key,
1468	>	*         or {@code null} if there was no mapping for the key
1469	>	* @throws NullPointerException if the specified key or value is null
1470	>	*/
1471	>	public V putIfAbsent(K key, V value) {
1472	>	return putVal(key, value, true);
1473	>	}
1474	>
1475	>	/**
1476	>	* {@inheritDoc}
1477	>	*
1478	>	* @throws NullPointerException if the specified key is null
1479	>	*/
1480	>	public boolean remove(Object key, Object value) {
1481	>	if (key == null)
1482	>	throw new NullPointerException();
1483	>	return value != null && replaceNode(key, null, value) != null;
1484	>	}
1485	>
1486	>	/**
1487	>	* {@inheritDoc}
1488	>	*
1489	>	* @throws NullPointerException if any of the arguments are null
1490	>	*/
1491	>	public boolean replace(K key, V oldValue, V newValue) {
1492	>	if (key == null || oldValue == null || newValue == null)
1493	>	throw new NullPointerException();
1494	>	return replaceNode(key, newValue, oldValue) != null;
1495	>	}
1496	>
1497	>	/**
1498	>	* {@inheritDoc}
1499	>	*
1500	>	* @return the previous value associated with the specified key,
1501	>	*         or {@code null} if there was no mapping for the key
1502	>	* @throws NullPointerException if the specified key or value is null
1503	>	*/
1504	>	public V replace(K key, V value) {
1505	>	if (key == null || value == null)
1506	>	throw new NullPointerException();
1507	>	return replaceNode(key, value, null);
1508	>	}
1509	>
1510	>	// Overrides of JDK8+ Map extension method defaults
1511	>
1512	>	/**
1513	>	* Returns the value to which the specified key is mapped, or the
1514	>	* given default value if this map contains no mapping for the
1515	>	* key.
1516	>	*
1517	>	* @param key the key whose associated value is to be returned
1518	>	* @param defaultValue the value to return if this map contains
1519	>	* no mapping for the given key
1520	>	* @return the mapping for the key, if present; else the default value
1521	>	* @throws NullPointerException if the specified key is null
1522	>	*/
1523	>	public V getOrDefault(Object key, V defaultValue) {
1524	>	V v;
1525	>	return (v = get(key)) == null ? defaultValue : v;
1526	>	}
1527	>
1528	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1529	>	if (action == null) throw new NullPointerException();
1530	>	Node<K,V>[] t;
1531	>	if ((t = table) != null) {
1532	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1533	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1534	>	action.accept(p.key, p.val);
1535	>	}
1536	>	}
1537	>	}
1538	>
1539	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1540	>	if (function == null) throw new NullPointerException();
1541	>	Node<K,V>[] t;
1542	>	if ((t = table) != null) {
1543	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1544	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1545	>	V oldValue = p.val;
1546	>	for (K key = p.key;;) {
1547	>	V newValue = function.apply(key, oldValue);
1548	>	if (newValue == null)
1549	>	throw new NullPointerException();
1550	>	if (replaceNode(key, newValue, oldValue) != null ||
1551	>	(oldValue = get(key)) == null)
1552	>	break;
1553	>	}
1554	>	}
1555	>	}
1556	>	}
1557	>
1558	>	/**
1559	>	* If the specified key is not already associated with a value,
1560	>	* attempts to compute its value using the given mapping function
1561	>	* and enters it into this map unless {@code null}.  The entire
1562	>	* method invocation is performed atomically, so the function is
1563	>	* applied at most once per key.  Some attempted update operations
1564	>	* on this map by other threads may be blocked while computation
1565	>	* is in progress, so the computation should be short and simple,
1566	>	* and must not attempt to update any other mappings of this map.
1567	>	*
1568	>	* @param key key with which the specified value is to be associated
1569	>	* @param mappingFunction the function to compute a value
1570	>	* @return the current (existing or computed) value associated with
1571	>	*         the specified key, or null if the computed value is null
1572	>	* @throws NullPointerException if the specified key or mappingFunction
1573	>	*         is null
1574	>	* @throws IllegalStateException if the computation detectably
1575	>	*         attempts a recursive update to this map that would
1576	>	*         otherwise never complete
1577	>	* @throws RuntimeException or Error if the mappingFunction does so,
1578	>	*         in which case the mapping is left unestablished
1579	>	*/
1580	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1581	>	if (key == null || mappingFunction == null)
1582	>	throw new NullPointerException();
1583	>	int h = spread(key.hashCode());
1584	>	V val = null;
1585	>	int binCount = 0;
1586	>	for (Node<K,V>[] tab = table;;) {
1587	>	Node<K,V> f; int n, i, fh;
1588	>	if (tab == null || (n = tab.length) == 0)
1589	>	tab = initTable();
1590	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1591	>	Node<K,V> r = new ReservationNode<K,V>();
1592	>	synchronized (r) {
1593	>	if (casTabAt(tab, i, null, r)) {
1594	>	binCount = 1;
1595	>	Node<K,V> node = null;
1596	>	try {
1597	>	if ((val = mappingFunction.apply(key)) != null)
1598	>	node = new Node<K,V>(h, key, val, null);
1599	>	} finally {
1600	>	setTabAt(tab, i, node);
1601	>	}
1602	>	}
1603	>	}
1604	>	if (binCount != 0)
1605	>	break;
1606	>	}
1607	>	else if ((fh = f.hash) == MOVED)
1608	>	tab = helpTransfer(tab, f);
1609	>	else {
1610	>	boolean added = false;
1611	>	synchronized (f) {
1612	>	if (tabAt(tab, i) == f) {
1613	>	if (fh >= 0) {
1614	>	binCount = 1;
1615	>	for (Node<K,V> e = f;; ++binCount) {
1616	>	K ek; V ev;
1617	>	if (e.hash == h &&
1618	>	((ek = e.key) == key ||
1619	>	(ek != null && key.equals(ek)))) {
1620	>	val = e.val;
1621	>	break;
1622	>	}
1623	>	Node<K,V> pred = e;
1624	>	if ((e = e.next) == null) {
1625	>	if ((val = mappingFunction.apply(key)) != null) {
1626	>	added = true;
1627	>	pred.next = new Node<K,V>(h, key, val, null);
1628	>	}
1629	>	break;
1630	>	}
1631	>	}
1632	>	}
1633	>	else if (f instanceof TreeBin) {
1634	>	binCount = 2;
1635	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1636	>	TreeNode<K,V> r, p;
1637	>	if ((r = t.root) != null &&
1638	>	(p = r.findTreeNode(h, key, null)) != null)
1639	>	val = p.val;
1640	>	else if ((val = mappingFunction.apply(key)) != null) {
1641	>	added = true;
1642	>	t.putTreeVal(h, key, val);
1643	>	}
1644	>	}
1645	>	}
1646	>	}
1647	>	if (binCount != 0) {
1648	>	if (binCount >= TREEIFY_THRESHOLD)
1649	>	treeifyBin(tab, i);
1650	>	if (!added)
1651	>	return val;
1652	>	break;
1653	>	}
1654	>	}
1655	>	}
1656	>	if (val != null)
1657	>	addCount(1L, binCount);
1658	>	return val;
1659	>	}
1660	>
1661	>	/**
1662	>	* If the value for the specified key is present, attempts to
1663	>	* compute a new mapping given the key and its current mapped
1664	>	* value.  The entire method invocation is performed atomically.
1665	>	* Some attempted update operations on this map by other threads
1666	>	* may be blocked while computation is in progress, so the
1667	>	* computation should be short and simple, and must not attempt to
1668	>	* update any other mappings of this map.
1669	>	*
1670	>	* @param key key with which a value may be associated
1671	>	* @param remappingFunction the function to compute a value
1672	>	* @return the new value associated with the specified key, or null if none
1673	>	* @throws NullPointerException if the specified key or remappingFunction
1674	>	*         is null
1675	>	* @throws IllegalStateException if the computation detectably
1676	>	*         attempts a recursive update to this map that would
1677	>	*         otherwise never complete
1678	>	* @throws RuntimeException or Error if the remappingFunction does so,
1679	>	*         in which case the mapping is unchanged
1680	>	*/
1681	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1682	>	if (key == null || remappingFunction == null)
1683	>	throw new NullPointerException();
1684	>	int h = spread(key.hashCode());
1685	>	V val = null;
1686	>	int delta = 0;
1687	>	int binCount = 0;
1688	>	for (Node<K,V>[] tab = table;;) {
1689	>	Node<K,V> f; int n, i, fh;
1690	>	if (tab == null || (n = tab.length) == 0)
1691	>	tab = initTable();
1692	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1693	>	break;
1694	>	else if ((fh = f.hash) == MOVED)
1695	>	tab = helpTransfer(tab, f);
1696	>	else {
1697	>	synchronized (f) {
1698	>	if (tabAt(tab, i) == f) {
1699	>	if (fh >= 0) {
1700	>	binCount = 1;
1701	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1702	>	K ek;
1703	>	if (e.hash == h &&
1704	>	((ek = e.key) == key ||
1705	>	(ek != null && key.equals(ek)))) {
1706	>	val = remappingFunction.apply(key, e.val);
1707	>	if (val != null)
1708	>	e.val = val;
1709	>	else {
1710	>	delta = -1;
1711	>	Node<K,V> en = e.next;
1712	>	if (pred != null)
1713	>	pred.next = en;
1714	>	else
1715	>	setTabAt(tab, i, en);
1716	>	}
1717	>	break;
1718	>	}
1719	>	pred = e;
1720	>	if ((e = e.next) == null)
1721	>	break;
1722	>	}
1723	>	}
1724	>	else if (f instanceof TreeBin) {
1725	>	binCount = 2;
1726	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1727	>	TreeNode<K,V> r, p;
1728	>	if ((r = t.root) != null &&
1729	>	(p = r.findTreeNode(h, key, null)) != null) {
1730	>	val = remappingFunction.apply(key, p.val);
1731	>	if (val != null)
1732	>	p.val = val;
1733	>	else {
1734	>	delta = -1;
1735	>	if (t.removeTreeNode(p))
1736	>	setTabAt(tab, i, untreeify(t.first));
1737	>	}
1738	>	}
1739	>	}
1740	>	}
1741	>	}
1742	>	if (binCount != 0)
1743	>	break;
1744	>	}
1745	>	}
1746	>	if (delta != 0)
1747	>	addCount((long)delta, binCount);
1748	>	return val;
1749	>	}
1750	>
1751	>	/**
1752	>	* Attempts to compute a mapping for the specified key and its
1753	>	* current mapped value (or {@code null} if there is no current
1754	>	* mapping). The entire method invocation is performed atomically.
1755	>	* Some attempted update operations on this map by other threads
1756	>	* may be blocked while computation is in progress, so the
1757	>	* computation should be short and simple, and must not attempt to
1758	>	* update any other mappings of this Map.
1759	>	*
1760	>	* @param key key with which the specified value is to be associated
1761	>	* @param remappingFunction the function to compute a value
1762	>	* @return the new value associated with the specified key, or null if none
1763	>	* @throws NullPointerException if the specified key or remappingFunction
1764	>	*         is null
1765	>	* @throws IllegalStateException if the computation detectably
1766	>	*         attempts a recursive update to this map that would
1767	>	*         otherwise never complete
1768	>	* @throws RuntimeException or Error if the remappingFunction does so,
1769	>	*         in which case the mapping is unchanged
1770	>	*/
1771	>	public V compute(K key,
1772	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1773	>	if (key == null || remappingFunction == null)
1774	>	throw new NullPointerException();
1775	>	int h = spread(key.hashCode());
1776	>	V val = null;
1777	>	int delta = 0;
1778	>	int binCount = 0;
1779	>	for (Node<K,V>[] tab = table;;) {
1780	>	Node<K,V> f; int n, i, fh;
1781	>	if (tab == null || (n = tab.length) == 0)
1782	>	tab = initTable();
1783	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1784	>	Node<K,V> r = new ReservationNode<K,V>();
1785	>	synchronized (r) {
1786	>	if (casTabAt(tab, i, null, r)) {
1787	>	binCount = 1;
1788	>	Node<K,V> node = null;
1789	>	try {
1790	>	if ((val = remappingFunction.apply(key, null)) != null) {
1791	>	delta = 1;
1792	>	node = new Node<K,V>(h, key, val, null);
1793	>	}
1794	>	} finally {
1795	>	setTabAt(tab, i, node);
1796	>	}
1797	>	}
1798	>	}
1799	>	if (binCount != 0)
1800	>	break;
1801	>	}
1802	>	else if ((fh = f.hash) == MOVED)
1803	>	tab = helpTransfer(tab, f);
1804	>	else {
1805	>	synchronized (f) {
1806	>	if (tabAt(tab, i) == f) {
1807	>	if (fh >= 0) {
1808	>	binCount = 1;
1809	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1810	>	K ek;
1811	>	if (e.hash == h &&
1812	>	((ek = e.key) == key ||
1813	>	(ek != null && key.equals(ek)))) {
1814	>	val = remappingFunction.apply(key, e.val);
1815	>	if (val != null)
1816	>	e.val = val;
1817	>	else {
1818	>	delta = -1;
1819	>	Node<K,V> en = e.next;
1820	>	if (pred != null)
1821	>	pred.next = en;
1822	>	else
1823	>	setTabAt(tab, i, en);
1824	>	}
1825	>	break;
1826	>	}
1827	>	pred = e;
1828	>	if ((e = e.next) == null) {
1829	>	val = remappingFunction.apply(key, null);
1830	>	if (val != null) {
1831	>	delta = 1;
1832	>	pred.next =
1833	>	new Node<K,V>(h, key, val, null);
1834	>	}
1835	>	break;
1836	>	}
1837	>	}
1838	>	}
1839	>	else if (f instanceof TreeBin) {
1840	>	binCount = 1;
1841	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1842	>	TreeNode<K,V> r, p;
1843	>	if ((r = t.root) != null)
1844	>	p = r.findTreeNode(h, key, null);
1845	>	else
1846	>	p = null;
1847	>	V pv = (p == null) ? null : p.val;
1848	>	val = remappingFunction.apply(key, pv);
1849	>	if (val != null) {
1850	>	if (p != null)
1851	>	p.val = val;
1852	>	else {
1853	>	delta = 1;
1854	>	t.putTreeVal(h, key, val);
1855	>	}
1856	>	}
1857	>	else if (p != null) {
1858	>	delta = -1;
1859	>	if (t.removeTreeNode(p))
1860	>	setTabAt(tab, i, untreeify(t.first));
1861	>	}
1862	>	}
1863	>	}
1864	>	}
1865	>	if (binCount != 0) {
1866	>	if (binCount >= TREEIFY_THRESHOLD)
1867	>	treeifyBin(tab, i);
1868	>	break;
1869	>	}
1870	>	}
1871	>	}
1872	>	if (delta != 0)
1873	>	addCount((long)delta, binCount);
1874	>	return val;
1875	>	}
1876	>
1877	>	/**
1878	>	* If the specified key is not already associated with a
1879	>	* (non-null) value, associates it with the given value.
1880	>	* Otherwise, replaces the value with the results of the given
1881	>	* remapping function, or removes if {@code null}. The entire
1882	>	* method invocation is performed atomically.  Some attempted
1883	>	* update operations on this map by other threads may be blocked
1884	>	* while computation is in progress, so the computation should be
1885	>	* short and simple, and must not attempt to update any other
1886	>	* mappings of this Map.
1887	>	*
1888	>	* @param key key with which the specified value is to be associated
1889	>	* @param value the value to use if absent
1890	>	* @param remappingFunction the function to recompute a value if present
1891	>	* @return the new value associated with the specified key, or null if none
1892	>	* @throws NullPointerException if the specified key or the
1893	>	*         remappingFunction is null
1894	>	* @throws RuntimeException or Error if the remappingFunction does so,
1895	>	*         in which case the mapping is unchanged
1896	>	*/
1897	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1898	>	if (key == null || value == null || remappingFunction == null)
1899	>	throw new NullPointerException();
1900	>	int h = spread(key.hashCode());
1901	>	V val = null;
1902	>	int delta = 0;
1903	>	int binCount = 0;
1904	>	for (Node<K,V>[] tab = table;;) {
1905	>	Node<K,V> f; int n, i, fh;
1906	>	if (tab == null || (n = tab.length) == 0)
1907	>	tab = initTable();
1908	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1909	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1910	>	delta = 1;
1911	>	val = value;
1912	>	break;
1913	>	}
1914	>	}
1915	>	else if ((fh = f.hash) == MOVED)
1916	>	tab = helpTransfer(tab, f);
1917	>	else {
1918	>	synchronized (f) {
1919	>	if (tabAt(tab, i) == f) {
1920	>	if (fh >= 0) {
1921	>	binCount = 1;
1922	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1923	>	K ek;
1924	>	if (e.hash == h &&
1925	>	((ek = e.key) == key ||
1926	>	(ek != null && key.equals(ek)))) {
1927	>	val = remappingFunction.apply(e.val, value);
1928	>	if (val != null)
1929	>	e.val = val;
1930	>	else {
1931	>	delta = -1;
1932	>	Node<K,V> en = e.next;
1933	>	if (pred != null)
1934	>	pred.next = en;
1935	>	else
1936	>	setTabAt(tab, i, en);
1937	>	}
1938	>	break;
1939	>	}
1940	>	pred = e;
1941	>	if ((e = e.next) == null) {
1942	>	delta = 1;
1943	>	val = value;
1944	>	pred.next =
1945	>	new Node<K,V>(h, key, val, null);
1946	>	break;
1947	>	}
1948	>	}
1949	>	}
1950	>	else if (f instanceof TreeBin) {
1951	>	binCount = 2;
1952	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1953	>	TreeNode<K,V> r = t.root;
1954	>	TreeNode<K,V> p = (r == null) ? null :
1955	>	r.findTreeNode(h, key, null);
1956	>	val = (p == null) ? value :
1957	>	remappingFunction.apply(p.val, value);
1958	>	if (val != null) {
1959	>	if (p != null)
1960	>	p.val = val;
1961	>	else {
1962	>	delta = 1;
1963	>	t.putTreeVal(h, key, val);
1964	>	}
1965	>	}
1966	>	else if (p != null) {
1967	>	delta = -1;
1968	>	if (t.removeTreeNode(p))
1969	>	setTabAt(tab, i, untreeify(t.first));
1970	>	}
1971	>	}
1972	>	}
1973	>	}
1974	>	if (binCount != 0) {
1975	>	if (binCount >= TREEIFY_THRESHOLD)
1976	>	treeifyBin(tab, i);
1977	>	break;
1978	>	}
1979	>	}
1980	>	}
1981	>	if (delta != 0)
1982	>	addCount((long)delta, binCount);
1983	>	return val;
1984	>	}
1985	>
1986	>	// Hashtable legacy methods
1987	>
1988	>	/**
1989	>	* Legacy method testing if some key maps into the specified value
1990	>	* in this table.  This method is identical in functionality to
1991	>	* {@link #containsValue(Object)}, and exists solely to ensure
1992	>	* full compatibility with class {@link java.util.Hashtable},
1993	>	* which supported this method prior to introduction of the
1994	>	* Java Collections framework.
1995	>	*
1996	>	* @param  value a value to search for
1997	>	* @return {@code true} if and only if some key maps to the
1998	>	*         {@code value} argument in this table as
1999	>	*         determined by the {@code equals} method;
2000	>	*         {@code false} otherwise
2001	>	* @throws NullPointerException if the specified value is null
2002	>	*/
2003	>	@Deprecated public boolean contains(Object value) {
2004	>	return containsValue(value);
2005		}
2006
2007		/**
2008		* Returns an enumeration of the keys in this table.
2009		*
2010		* @return an enumeration of the keys in this table
2011	<	* @see #keySet
2011	>	* @see #keySet()
2012		*/
2013		public Enumeration<K> keys() {
2014	<	return new KeyIterator();
2014	>	Node<K,V>[] t;
2015	>	int f = (t = table) == null ? 0 : t.length;
2016	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2017		}
2018
2019		/**
2020		* Returns an enumeration of the values in this table.
2021		*
2022		* @return an enumeration of the values in this table
2023	<	* @see #values
2023	>	* @see #values()
2024		*/
2025		public Enumeration<V> elements() {
2026	<	return new ValueIterator();
2026	>	Node<K,V>[] t;
2027	>	int f = (t = table) == null ? 0 : t.length;
2028	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2029		}
2030
2031	<	/* ---------------- Iterator Support -------------- */
2031	>	// ConcurrentHashMap-only methods
2032
2033	<	abstract class HashIterator {
2034	<	int nextSegmentIndex;
2035	<	int nextTableIndex;
2036	<	HashEntry<K,V>[] currentTable;
2037	<	HashEntry<K, V> nextEntry;
2038	<	HashEntry<K, V> lastReturned;
2033	>	/**
2034	>	* Returns the number of mappings. This method should be used
2035	>	* instead of {@link #size} because a ConcurrentHashMap may
2036	>	* contain more mappings than can be represented as an int. The
2037	>	* value returned is an estimate; the actual count may differ if
2038	>	* there are concurrent insertions or removals.
2039	>	*
2040	>	* @return the number of mappings
2041	>	* @since 1.8
2042	>	*/
2043	>	public long mappingCount() {
2044	>	long n = sumCount();
2045	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2046	>	}
2047
2048	<	HashIterator() {
2049	<	nextSegmentIndex = segments.length - 1;
2050	<	nextTableIndex = -1;
2051	<	advance();
2048	>	/**
2049	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2050	>	* from the given type to {@code Boolean.TRUE}.
2051	>	*
2052	>	* @return the new set
2053	>	* @since 1.8
2054	>	*/
2055	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2056	>	return new KeySetView<K,Boolean>
2057	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2058	>	}
2059	>
2060	>	/**
2061	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2062	>	* from the given type to {@code Boolean.TRUE}.
2063	>	*
2064	>	* @param initialCapacity The implementation performs internal
2065	>	* sizing to accommodate this many elements.
2066	>	* @throws IllegalArgumentException if the initial capacity of
2067	>	* elements is negative
2068	>	* @return the new set
2069	>	* @since 1.8
2070	>	*/
2071	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2072	>	return new KeySetView<K,Boolean>
2073	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2074	>	}
2075	>
2076	>	/**
2077	>	* Returns a {@link Set} view of the keys in this map, using the
2078	>	* given common mapped value for any additions (i.e., {@link
2079	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2080	>	* This is of course only appropriate if it is acceptable to use
2081	>	* the same value for all additions from this view.
2082	>	*
2083	>	* @param mappedValue the mapped value to use for any additions
2084	>	* @return the set view
2085	>	* @throws NullPointerException if the mappedValue is null
2086	>	*/
2087	>	public KeySetView<K,V> keySet(V mappedValue) {
2088	>	if (mappedValue == null)
2089	>	throw new NullPointerException();
2090	>	return new KeySetView<K,V>(this, mappedValue);
2091	>	}
2092	>
2093	>	/* ---------------- Special Nodes -------------- */
2094	>
2095	>	/**
2096	>	* A node inserted at head of bins during transfer operations.
2097	>	*/
2098	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2099	>	final Node<K,V>[] nextTable;
2100	>	ForwardingNode(Node<K,V>[] tab) {
2101	>	super(MOVED, null, null, null);
2102	>	this.nextTable = tab;
2103	>	}
2104	>
2105	>	Node<K,V> find(int h, Object k) {
2106	>	Node<K,V> e; int n;
2107	>	Node<K,V>[] tab = nextTable;
2108	>	if (k != null && tab != null && (n = tab.length) > 0 &&
2109	>	(e = tabAt(tab, (n - 1) & h)) != null) {
2110	>	do {
2111	>	int eh; K ek;
2112	>	if ((eh = e.hash) == h &&
2113	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2114	>	return e;
2115	>	if (eh < 0)
2116	>	return e.find(h, k);
2117	>	} while ((e = e.next) != null);
2118	>	}
2119	>	return null;
2120	>	}
2121	>	}
2122	>
2123	>	/**
2124	>	* A place-holder node used in computeIfAbsent and compute
2125	>	*/
2126	>	static final class ReservationNode<K,V> extends Node<K,V> {
2127	>	ReservationNode() {
2128	>	super(RESERVED, null, null, null);
2129	>	}
2130	>
2131	>	Node<K,V> find(int h, Object k) {
2132	>	return null;
2133	>	}
2134	>	}
2135	>
2136	>	/* ---------------- Table Initialization and Resizing -------------- */
2137	>
2138	>	/**
2139	>	* Initializes table, using the size recorded in sizeCtl.
2140	>	*/
2141	>	private final Node<K,V>[] initTable() {
2142	>	Node<K,V>[] tab; int sc;
2143	>	while ((tab = table) == null || tab.length == 0) {
2144	>	if ((sc = sizeCtl) < 0)
2145	>	Thread.yield(); // lost initialization race; just spin
2146	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2147	>	try {
2148	>	if ((tab = table) == null || tab.length == 0) {
2149	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2150	>	@SuppressWarnings({"rawtypes","unchecked"})
2151	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2152	>	table = tab = nt;
2153	>	sc = n - (n >>> 2);
2154	>	}
2155	>	} finally {
2156	>	sizeCtl = sc;
2157	>	}
2158	>	break;
2159	>	}
2160		}
2161	+	return tab;
2162	+	}
2163
2164	<	public boolean hasMoreElements() { return hasNext(); }
2164	>	/**
2165	>	* Adds to count, and if table is too small and not already
2166	>	* resizing, initiates transfer. If already resizing, helps
2167	>	* perform transfer if work is available.  Rechecks occupancy
2168	>	* after a transfer to see if another resize is already needed
2169	>	* because resizings are lagging additions.
2170	>	*
2171	>	* @param x the count to add
2172	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2173	>	*/
2174	>	private final void addCount(long x, int check) {
2175	>	CounterCell[] as; long b, s;
2176	>	if ((as = counterCells) != null ||
2177	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2178	>	CounterCell a; long v; int m;
2179	>	boolean uncontended = true;
2180	>	if (as == null || (m = as.length - 1) < 0 ||
2181	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2182	>	!(uncontended =
2183	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2184	>	fullAddCount(x, uncontended);
2185	>	return;
2186	>	}
2187	>	if (check <= 1)
2188	>	return;
2189	>	s = sumCount();
2190	>	}
2191	>	if (check >= 0) {
2192	>	Node<K,V>[] tab, nt; int sc;
2193	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2194	>	tab.length < MAXIMUM_CAPACITY) {
2195	>	if (sc < 0) {
2196	>	if (sc == -1 || transferIndex <= transferOrigin ||
2197	>	(nt = nextTable) == null)
2198	>	break;
2199	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2200	>	transfer(tab, nt);
2201	>	}
2202	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2203	>	transfer(tab, null);
2204	>	s = sumCount();
2205	>	}
2206	>	}
2207	>	}
2208
2209	<	final void advance() {
2210	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
2209	>	/**
2210	>	* Helps transfer if a resize is in progress.
2211	>	*/
2212	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2213	>	Node<K,V>[] nextTab; int sc;
2214	>	if ((f instanceof ForwardingNode) &&
2215	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2216	>	if (nextTab == nextTable && tab == table &&
2217	>	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2218	>	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2219	>	transfer(tab, nextTab);
2220	>	return nextTab;
2221	>	}
2222	>	return table;
2223	>	}
2224	>
2225	>	/**
2226	>	* Tries to presize table to accommodate the given number of elements.
2227	>	*
2228	>	* @param size number of elements (doesn't need to be perfectly accurate)
2229	>	*/
2230	>	private final void tryPresize(int size) {
2231	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2232	>	tableSizeFor(size + (size >>> 1) + 1);
2233	>	int sc;
2234	>	while ((sc = sizeCtl) >= 0) {
2235	>	Node<K,V>[] tab = table; int n;
2236	>	if (tab == null || (n = tab.length) == 0) {
2237	>	n = (sc > c) ? sc : c;
2238	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2239	>	try {
2240	>	if (table == tab) {
2241	>	@SuppressWarnings({"rawtypes","unchecked"})
2242	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2243	>	table = nt;
2244	>	sc = n - (n >>> 2);
2245	>	}
2246	>	} finally {
2247	>	sizeCtl = sc;
2248	>	}
2249	>	}
2250	>	}
2251	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2252	>	break;
2253	>	else if (tab == table &&
2254	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2255	>	transfer(tab, null);
2256	>	}
2257	>	}
2258	>
2259	>	/**
2260	>	* Moves and/or copies the nodes in each bin to new table. See
2261	>	* above for explanation.
2262	>	*/
2263	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2264	>	int n = tab.length, stride;
2265	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2266	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2267	>	if (nextTab == null) {            // initiating
2268	>	try {
2269	>	@SuppressWarnings({"rawtypes","unchecked"})
2270	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2271	>	nextTab = nt;
2272	>	} catch (Throwable ex) {      // try to cope with OOME
2273	>	sizeCtl = Integer.MAX_VALUE;
2274		return;
2275	+	}
2276	+	nextTable = nextTab;
2277	+	transferOrigin = n;
2278	+	transferIndex = n;
2279	+	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2280	+	for (int k = n; k > 0;) {    // progressively reveal ready slots
2281	+	int nextk = (k > stride) ? k - stride : 0;
2282	+	for (int m = nextk; m < k; ++m)
2283	+	nextTab[m] = rev;
2284	+	for (int m = n + nextk; m < n + k; ++m)
2285	+	nextTab[m] = rev;
2286	+	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2287	+	}
2288	+	}
2289	+	int nextn = nextTab.length;
2290	+	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2291	+	boolean advance = true;
2292	+	for (int i = 0, bound = 0;;) {
2293	+	int nextIndex, nextBound, fh; Node<K,V> f;
2294	+	while (advance) {
2295	+	if (--i >= bound)
2296	+	advance = false;
2297	+	else if ((nextIndex = transferIndex) <= transferOrigin) {
2298	+	i = -1;
2299	+	advance = false;
2300	+	}
2301	+	else if (U.compareAndSwapInt
2302	+	(this, TRANSFERINDEX, nextIndex,
2303	+	nextBound = (nextIndex > stride ?
2304	+	nextIndex - stride : 0))) {
2305	+	bound = nextBound;
2306	+	i = nextIndex - 1;
2307	+	advance = false;
2308	+	}
2309	+	}
2310	+	if (i < 0 || i >= n || i + n >= nextn) {
2311	+	for (int sc;;) {
2312	+	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2313	+	if (sc == -1) {
2314	+	nextTable = null;
2315	+	table = nextTab;
2316	+	sizeCtl = (n << 1) - (n >>> 1);
2317	+	}
2318	+	return;
2319	+	}
2320	+	}
2321	+	}
2322	+	else if ((f = tabAt(tab, i)) == null) {
2323	+	if (casTabAt(tab, i, null, fwd)) {
2324	+	setTabAt(nextTab, i, null);
2325	+	setTabAt(nextTab, i + n, null);
2326	+	advance = true;
2327	+	}
2328	+	}
2329	+	else if ((fh = f.hash) == MOVED)
2330	+	advance = true; // already processed
2331	+	else {
2332	+	synchronized (f) {
2333	+	if (tabAt(tab, i) == f) {
2334	+	Node<K,V> ln, hn;
2335	+	if (fh >= 0) {
2336	+	int runBit = fh & n;
2337	+	Node<K,V> lastRun = f;
2338	+	for (Node<K,V> p = f.next; p != null; p = p.next) {
2339	+	int b = p.hash & n;
2340	+	if (b != runBit) {
2341	+	runBit = b;
2342	+	lastRun = p;
2343	+	}
2344	+	}
2345	+	if (runBit == 0) {
2346	+	ln = lastRun;
2347	+	hn = null;
2348	+	}
2349	+	else {
2350	+	hn = lastRun;
2351	+	ln = null;
2352	+	}
2353	+	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2354	+	int ph = p.hash; K pk = p.key; V pv = p.val;
2355	+	if ((ph & n) == 0)
2356	+	ln = new Node<K,V>(ph, pk, pv, ln);
2357	+	else
2358	+	hn = new Node<K,V>(ph, pk, pv, hn);
2359	+	}
2360	+	}
2361	+	else if (f instanceof TreeBin) {
2362	+	TreeBin<K,V> t = (TreeBin<K,V>)f;
2363	+	TreeNode<K,V> lo = null, loTail = null;
2364	+	TreeNode<K,V> hi = null, hiTail = null;
2365	+	int lc = 0, hc = 0;
2366	+	for (Node<K,V> e = t.first; e != null; e = e.next) {
2367	+	int h = e.hash;
2368	+	TreeNode<K,V> p = new TreeNode<K,V>
2369	+	(h, e.key, e.val, null, null);
2370	+	if ((h & n) == 0) {
2371	+	if ((p.prev = loTail) == null)
2372	+	lo = p;
2373	+	else
2374	+	loTail.next = p;
2375	+	loTail = p;
2376	+	++lc;
2377	+	}
2378	+	else {
2379	+	if ((p.prev = hiTail) == null)
2380	+	hi = p;
2381	+	else
2382	+	hiTail.next = p;
2383	+	hiTail = p;
2384	+	++hc;
2385	+	}
2386	+	}
2387	+	ln = (lc <= UNTREEIFY_THRESHOLD ?  untreeify(lo) :
2388	+	(hc != 0) ? new TreeBin<K,V>(lo) : t);
2389	+	hn = (hc <= UNTREEIFY_THRESHOLD ? untreeify(hi) :
2390	+	(lc != 0) ? new TreeBin<K,V>(hi) : t);
2391	+	}
2392	+	else
2393	+	ln = hn = null;
2394	+	setTabAt(nextTab, i, ln);
2395	+	setTabAt(nextTab, i + n, hn);
2396	+	setTabAt(tab, i, fwd);
2397	+	advance = true;
2398	+	}
2399	+	}
2400	+	}
2401	+	}
2402	+	}
2403	+
2404	+	/* ---------------- Counter support -------------- */
2405
2406	<	while (nextTableIndex >= 0) {
2407	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
2408	<	return;
2406	>	/**
2407	>	* A padded cell for distributing counts.  Adapted from LongAdder
2408	>	* and Striped64.  See their internal docs for explanation.
2409	>	*/
2410	>	@sun.misc.Contended static final class CounterCell {
2411	>	volatile long value;
2412	>	CounterCell(long x) { value = x; }
2413	>	}
2414	>
2415	>	final long sumCount() {
2416	>	CounterCell[] as = counterCells; CounterCell a;
2417	>	long sum = baseCount;
2418	>	if (as != null) {
2419	>	for (int i = 0; i < as.length; ++i) {
2420	>	if ((a = as[i]) != null)
2421	>	sum += a.value;
2422		}
2423	+	}
2424	+	return sum;
2425	+	}
2426
2427	<	while (nextSegmentIndex >= 0) {
2428	<	Segment<K,V> seg = segments[nextSegmentIndex--];
2429	<	if (seg.count != 0) {
2430	<	currentTable = seg.table;
2431	<	for (int j = currentTable.length - 1; j >= 0; --j) {
2432	<	if ( (nextEntry = currentTable[j]) != null) {
2433	<	nextTableIndex = j - 1;
2434	<	return;
2427	>	// See LongAdder version for explanation
2428	>	private final void fullAddCount(long x, boolean wasUncontended) {
2429	>	int h;
2430	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2431	>	ThreadLocalRandom.localInit();      // force initialization
2432	>	h = ThreadLocalRandom.getProbe();
2433	>	wasUncontended = true;
2434	>	}
2435	>	boolean collide = false;                // True if last slot nonempty
2436	>	for (;;) {
2437	>	CounterCell[] as; CounterCell a; int n; long v;
2438	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2439	>	if ((a = as[(n - 1) & h]) == null) {
2440	>	if (cellsBusy == 0) {            // Try to attach new Cell
2441	>	CounterCell r = new CounterCell(x); // Optimistic create
2442	>	if (cellsBusy == 0 &&
2443	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2444	>	boolean created = false;
2445	>	try {               // Recheck under lock
2446	>	CounterCell[] rs; int m, j;
2447	>	if ((rs = counterCells) != null &&
2448	>	(m = rs.length) > 0 &&
2449	>	rs[j = (m - 1) & h] == null) {
2450	>	rs[j] = r;
2451	>	created = true;
2452	>	}
2453	>	} finally {
2454	>	cellsBusy = 0;
2455	>	}
2456	>	if (created)
2457	>	break;
2458	>	continue;           // Slot is now non-empty
2459	>	}
2460	>	}
2461	>	collide = false;
2462	>	}
2463	>	else if (!wasUncontended)       // CAS already known to fail
2464	>	wasUncontended = true;      // Continue after rehash
2465	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2466	>	break;
2467	>	else if (counterCells != as || n >= NCPU)
2468	>	collide = false;            // At max size or stale
2469	>	else if (!collide)
2470	>	collide = true;
2471	>	else if (cellsBusy == 0 &&
2472	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2473	>	try {
2474	>	if (counterCells == as) {// Expand table unless stale
2475	>	CounterCell[] rs = new CounterCell[n << 1];
2476	>	for (int i = 0; i < n; ++i)
2477	>	rs[i] = as[i];
2478	>	counterCells = rs;
2479		}
2480	+	} finally {
2481	+	cellsBusy = 0;
2482		}
2483	+	collide = false;
2484	+	continue;                   // Retry with expanded table
2485		}
2486	+	h = ThreadLocalRandom.advanceProbe(h);
2487		}
2488	+	else if (cellsBusy == 0 && counterCells == as &&
2489	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2490	+	boolean init = false;
2491	+	try {                           // Initialize table
2492	+	if (counterCells == as) {
2493	+	CounterCell[] rs = new CounterCell[2];
2494	+	rs[h & 1] = new CounterCell(x);
2495	+	counterCells = rs;
2496	+	init = true;
2497	+	}
2498	+	} finally {
2499	+	cellsBusy = 0;
2500	+	}
2501	+	if (init)
2502	+	break;
2503	+	}
2504	+	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2505	+	break;                          // Fall back on using base
2506		}
2507	+	}
2508
2509	<	public boolean hasNext() { return nextEntry != null; }
2509	>	/* ---------------- Conversion from/to TreeBins -------------- */
2510
2511	<	HashEntry<K,V> nextEntry() {
2512	<	if (nextEntry == null)
2513	<	throw new NoSuchElementException();
2514	<	lastReturned = nextEntry;
2511	>	/**
2512	>	* Replaces all linked nodes in bin at given index unless table is
2513	>	* too small, in which case resizes instead.
2514	>	*/
2515	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2516	>	Node<K,V> b; int n, sc;
2517	>	if (tab != null) {
2518	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY) {
2519	>	if (tab == table && (sc = sizeCtl) >= 0 &&
2520	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2521	>	transfer(tab, null);
2522	>	}
2523	>	else if ((b = tabAt(tab, index)) != null) {
2524	>	synchronized (b) {
2525	>	if (tabAt(tab, index) == b) {
2526	>	TreeNode<K,V> hd = null, tl = null;
2527	>	for (Node<K,V> e = b; e != null; e = e.next) {
2528	>	TreeNode<K,V> p =
2529	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2530	>	null, null);
2531	>	if ((p.prev = tl) == null)
2532	>	hd = p;
2533	>	else
2534	>	tl.next = p;
2535	>	tl = p;
2536	>	}
2537	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2538	>	}
2539	>	}
2540	>	}
2541	>	}
2542	>	}
2543	>
2544	>	/**
2545	>	* Returns a list on non-TreeNodes replacing those in given list
2546	>	*/
2547	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2548	>	Node<K,V> hd = null, tl = null;
2549	>	for (Node<K,V> q = b; q != null; q = q.next) {
2550	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2551	>	if (tl == null)
2552	>	hd = p;
2553	>	else
2554	>	tl.next = p;
2555	>	tl = p;
2556	>	}
2557	>	return hd;
2558	>	}
2559	>
2560	>	/* ---------------- TreeNodes -------------- */
2561	>
2562	>	/**
2563	>	* Nodes for use in TreeBins
2564	>	*/
2565	>	static final class TreeNode<K,V> extends Node<K,V> {
2566	>	TreeNode<K,V> parent;  // red-black tree links
2567	>	TreeNode<K,V> left;
2568	>	TreeNode<K,V> right;
2569	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2570	>	boolean red;
2571	>
2572	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2573	>	TreeNode<K,V> parent) {
2574	>	super(hash, key, val, next);
2575	>	this.parent = parent;
2576	>	}
2577	>
2578	>	Node<K,V> find(int h, Object k) {
2579	>	return findTreeNode(h, k, null);
2580	>	}
2581	>
2582	>	/**
2583	>	* Returns the TreeNode (or null if not found) for the given key
2584	>	* starting at given root.
2585	>	*/
2586	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2587	>	if (k != null) {
2588	>	TreeNode<K,V> p = this;
2589	>	do  {
2590	>	int ph, dir; K pk; TreeNode<K,V> q;
2591	>	TreeNode<K,V> pl = p.left, pr = p.right;
2592	>	if ((ph = p.hash) > h)
2593	>	p = pl;
2594	>	else if (ph < h)
2595	>	p = pr;
2596	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2597	>	return p;
2598	>	else if (pl == null && pr == null)
2599	>	break;
2600	>	else if ((kc != null ||
2601	>	(kc = comparableClassFor(k)) != null) &&
2602	>	(dir = compareComparables(kc, k, pk)) != 0)
2603	>	p = (dir < 0) ? pl : pr;
2604	>	else if (pl == null)
2605	>	p = pr;
2606	>	else if (pr == null ||
2607	>	(q = pr.findTreeNode(h, k, kc)) == null)
2608	>	p = pl;
2609	>	else
2610	>	return q;
2611	>	} while (p != null);
2612	>	}
2613	>	return null;
2614	>	}
2615	>	}
2616	>
2617	>	/* ---------------- TreeBins -------------- */
2618	>
2619	>	/**
2620	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2621	>	* keys or values, but instead point to list of TreeNodes and
2622	>	* their root. They also maintain a parasitic read-write lock
2623	>	* forcing writers (who hold bin lock) to wait for readers (who do
2624	>	* not) to complete before tree restructuring operations.
2625	>	*/
2626	>	static final class TreeBin<K,V> extends Node<K,V> {
2627	>	TreeNode<K,V> root;
2628	>	volatile TreeNode<K,V> first;
2629	>	volatile Thread waiter;
2630	>	volatile int lockState;
2631	>	// values for lockState
2632	>	static final int WRITER = 1; // set while holding write lock
2633	>	static final int WAITER = 2; // set when waiting for write lock
2634	>	static final int READER = 4; // increment value for setting read lock
2635	>
2636	>	/**
2637	>	* Creates bin with initial set of nodes headed by b.
2638	>	*/
2639	>	TreeBin(TreeNode<K,V> b) {
2640	>	super(TREEBIN, null, null, null);
2641	>	this.first = b;
2642	>	TreeNode<K,V> r = null;
2643	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2644	>	next = (TreeNode<K,V>)x.next;
2645	>	x.left = x.right = null;
2646	>	if (r == null) {
2647	>	x.parent = null;
2648	>	x.red = false;
2649	>	r = x;
2650	>	}
2651	>	else {
2652	>	Object key = x.key;
2653	>	int hash = x.hash;
2654	>	Class<?> kc = null;
2655	>	for (TreeNode<K,V> p = r;;) {
2656	>	int dir, ph;
2657	>	if ((ph = p.hash) > hash)
2658	>	dir = -1;
2659	>	else if (ph < hash)
2660	>	dir = 1;
2661	>	else if ((kc != null ||
2662	>	(kc = comparableClassFor(key)) != null))
2663	>	dir = compareComparables(kc, key, p.key);
2664	>	else
2665	>	dir = 0;
2666	>	TreeNode<K,V> xp = p;
2667	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2668	>	x.parent = xp;
2669	>	if (dir <= 0)
2670	>	xp.left = x;
2671	>	else
2672	>	xp.right = x;
2673	>	r = balanceInsertion(r, x);
2674	>	break;
2675	>	}
2676	>	}
2677	>	}
2678	>	}
2679	>	this.root = r;
2680	>	}
2681	>
2682	>	/**
2683	>	* Acquires write lock for tree restructuring
2684	>	*/
2685	>	private final void lockRoot() {
2686	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2687	>	contendedLock(); // offload to separate method
2688	>	}
2689	>
2690	>	/**
2691	>	* Releases write lock for tree restructuring
2692	>	*/
2693	>	private final void unlockRoot() {
2694	>	lockState = 0;
2695	>	}
2696	>
2697	>	/**
2698	>	* Possibly blocks awaiting root lock
2699	>	*/
2700	>	private final void contendedLock() {
2701	>	boolean waiting = false;
2702	>	for (int s;;) {
2703	>	if (((s = lockState) & WRITER) == 0) {
2704	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2705	>	if (waiting)
2706	>	waiter = null;
2707	>	return;
2708	>	}
2709	>	}
2710	>	else if ((s | WAITER) == 0) {
2711	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2712	>	waiting = true;
2713	>	waiter = Thread.currentThread();
2714	>	}
2715	>	}
2716	>	else if (waiting)
2717	>	LockSupport.park(this);
2718	>	}
2719	>	}
2720	>
2721	>	/**
2722	>	* Returns matching node or null if none. Tries to search
2723	>	* using tree compareisons from root, but continues linear
2724	>	* search when lock not available.
2725	>	*/
2726	>	final Node<K,V> find(int h, Object k) {
2727	>	if (k != null) {
2728	>	for (Node<K,V> e = first; e != null; e = e.next) {
2729	>	int s; K ek;
2730	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2731	>	if (e.hash == h &&
2732	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2733	>	return e;
2734	>	}
2735	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2736	>	s + READER)) {
2737	>	TreeNode<K,V> r, p;
2738	>	try {
2739	>	p = ((r = root) == null ? null :
2740	>	r.findTreeNode(h, k, null));
2741	>	} finally {
2742	>	Thread w;
2743	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2744	>	(READER|WAITER) && (w = waiter) != null)
2745	>	LockSupport.unpark(w);
2746	>	}
2747	>	return p;
2748	>	}
2749	>	}
2750	>	}
2751	>	return null;
2752	>	}
2753	>
2754	>	/**
2755	>	* Finds or adds a node.
2756	>	* @return null if added
2757	>	*/
2758	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2759	>	Class<?> kc = null;
2760	>	for (TreeNode<K,V> p = root;;) {
2761	>	int dir, ph; K pk; TreeNode<K,V> q, pr;
2762	>	if (p == null) {
2763	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2764	>	break;
2765	>	}
2766	>	else if ((ph = p.hash) > h)
2767	>	dir = -1;
2768	>	else if (ph < h)
2769	>	dir = 1;
2770	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2771	>	return p;
2772	>	else if ((kc == null &&
2773	>	(kc = comparableClassFor(k)) == null) ||
2774	>	(dir = compareComparables(kc, k, pk)) == 0) {
2775	>	if (p.left == null)
2776	>	dir = 1;
2777	>	else if ((pr = p.right) == null ||
2778	>	(q = pr.findTreeNode(h, k, kc)) == null)
2779	>	dir = -1;
2780	>	else
2781	>	return q;
2782	>	}
2783	>	TreeNode<K,V> xp = p;
2784	>	if ((p = (dir < 0) ? p.left : p.right) == null) {
2785	>	TreeNode<K,V> x, f = first;
2786	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2787	>	if (f != null)
2788	>	f.prev = x;
2789	>	if (dir < 0)
2790	>	xp.left = x;
2791	>	else
2792	>	xp.right = x;
2793	>	if (!xp.red)
2794	>	x.red = true;
2795	>	else {
2796	>	lockRoot();
2797	>	try {
2798	>	root = balanceInsertion(root, x);
2799	>	} finally {
2800	>	unlockRoot();
2801	>	}
2802	>	}
2803	>	break;
2804	>	}
2805	>	}
2806	>	assert checkInvariants(root);
2807	>	return null;
2808	>	}
2809	>
2810	>	/**
2811	>	* Removes the given node, that must be present before this
2812	>	* call.  This is messier than typical red-black deletion code
2813	>	* because we cannot swap the contents of an interior node
2814	>	* with a leaf successor that is pinned by "next" pointers
2815	>	* that are accessible independently of lock. So instead we
2816	>	* swap the tree linkages.
2817	>	*
2818	>	* @return true if now too small so should be untreeified.
2819	>	*/
2820	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2821	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2822	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2823	>	TreeNode<K,V> r, rl;
2824	>	if (pred == null)
2825	>	first = next;
2826	>	else
2827	>	pred.next = next;
2828	>	if (next != null)
2829	>	next.prev = pred;
2830	>	if (first == null) {
2831	>	root = null;
2832	>	return true;
2833	>	}
2834	>	if ((r = root) == null || r.right == null || // too small
2835	>	(rl = r.left) == null || rl.left == null)
2836	>	return true;
2837	>	lockRoot();
2838	>	try {
2839	>	TreeNode<K,V> replacement;
2840	>	TreeNode<K,V> pl = p.left;
2841	>	TreeNode<K,V> pr = p.right;
2842	>	if (pl != null && pr != null) {
2843	>	TreeNode<K,V> s = pr, sl;
2844	>	while ((sl = s.left) != null) // find successor
2845	>	s = sl;
2846	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2847	>	TreeNode<K,V> sr = s.right;
2848	>	TreeNode<K,V> pp = p.parent;
2849	>	if (s == pr) { // p was s's direct parent
2850	>	p.parent = s;
2851	>	s.right = p;
2852	>	}
2853	>	else {
2854	>	TreeNode<K,V> sp = s.parent;
2855	>	if ((p.parent = sp) != null) {
2856	>	if (s == sp.left)
2857	>	sp.left = p;
2858	>	else
2859	>	sp.right = p;
2860	>	}
2861	>	if ((s.right = pr) != null)
2862	>	pr.parent = s;
2863	>	}
2864	>	p.left = null;
2865	>	if ((p.right = sr) != null)
2866	>	sr.parent = p;
2867	>	if ((s.left = pl) != null)
2868	>	pl.parent = s;
2869	>	if ((s.parent = pp) == null)
2870	>	r = s;
2871	>	else if (p == pp.left)
2872	>	pp.left = s;
2873	>	else
2874	>	pp.right = s;
2875	>	if (sr != null)
2876	>	replacement = sr;
2877	>	else
2878	>	replacement = p;
2879	>	}
2880	>	else if (pl != null)
2881	>	replacement = pl;
2882	>	else if (pr != null)
2883	>	replacement = pr;
2884	>	else
2885	>	replacement = p;
2886	>	if (replacement != p) {
2887	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2888	>	if (pp == null)
2889	>	r = replacement;
2890	>	else if (p == pp.left)
2891	>	pp.left = replacement;
2892	>	else
2893	>	pp.right = replacement;
2894	>	p.left = p.right = p.parent = null;
2895	>	}
2896	>
2897	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2898	>
2899	>	if (p == replacement) {  // detach pointers
2900	>	TreeNode<K,V> pp;
2901	>	if ((pp = p.parent) != null) {
2902	>	if (p == pp.left)
2903	>	pp.left = null;
2904	>	else if (p == pp.right)
2905	>	pp.right = null;
2906	>	p.parent = null;
2907	>	}
2908	>	}
2909	>	} finally {
2910	>	unlockRoot();
2911	>	}
2912	>	assert checkInvariants(root);
2913	>	return false;
2914	>	}
2915	>
2916	>	/* ------------------------------------------------------------ */
2917	>	// Red-black tree methods, all adapted from CLR
2918	>
2919	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2920	>	TreeNode<K,V> p) {
2921	>	TreeNode<K,V> r, pp, rl;
2922	>	if (p != null && (r = p.right) != null) {
2923	>	if ((rl = p.right = r.left) != null)
2924	>	rl.parent = p;
2925	>	if ((pp = r.parent = p.parent) == null)
2926	>	(root = r).red = false;
2927	>	else if (pp.left == p)
2928	>	pp.left = r;
2929	>	else
2930	>	pp.right = r;
2931	>	r.left = p;
2932	>	p.parent = r;
2933	>	}
2934	>	return root;
2935	>	}
2936	>
2937	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2938	>	TreeNode<K,V> p) {
2939	>	TreeNode<K,V> l, pp, lr;
2940	>	if (p != null && (l = p.left) != null) {
2941	>	if ((lr = p.left = l.right) != null)
2942	>	lr.parent = p;
2943	>	if ((pp = l.parent = p.parent) == null)
2944	>	(root = l).red = false;
2945	>	else if (pp.right == p)
2946	>	pp.right = l;
2947	>	else
2948	>	pp.left = l;
2949	>	l.right = p;
2950	>	p.parent = l;
2951	>	}
2952	>	return root;
2953	>	}
2954	>
2955	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2956	>	TreeNode<K,V> x) {
2957	>	x.red = true;
2958	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2959	>	if ((xp = x.parent) == null) {
2960	>	x.red = false;
2961	>	return x;
2962	>	}
2963	>	else if (!xp.red || (xpp = xp.parent) == null)
2964	>	return root;
2965	>	if (xp == (xppl = xpp.left)) {
2966	>	if ((xppr = xpp.right) != null && xppr.red) {
2967	>	xppr.red = false;
2968	>	xp.red = false;
2969	>	xpp.red = true;
2970	>	x = xpp;
2971	>	}
2972	>	else {
2973	>	if (x == xp.right) {
2974	>	root = rotateLeft(root, x = xp);
2975	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2976	>	}
2977	>	if (xp != null) {
2978	>	xp.red = false;
2979	>	if (xpp != null) {
2980	>	xpp.red = true;
2981	>	root = rotateRight(root, xpp);
2982	>	}
2983	>	}
2984	>	}
2985	>	}
2986	>	else {
2987	>	if (xppl != null && xppl.red) {
2988	>	xppl.red = false;
2989	>	xp.red = false;
2990	>	xpp.red = true;
2991	>	x = xpp;
2992	>	}
2993	>	else {
2994	>	if (x == xp.left) {
2995	>	root = rotateRight(root, x = xp);
2996	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2997	>	}
2998	>	if (xp != null) {
2999	>	xp.red = false;
3000	>	if (xpp != null) {
3001	>	xpp.red = true;
3002	>	root = rotateLeft(root, xpp);
3003	>	}
3004	>	}
3005	>	}
3006	>	}
3007	>	}
3008	>	}
3009	>
3010	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3011	>	TreeNode<K,V> x) {
3012	>	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3013	>	if (x == null || x == root)
3014	>	return root;
3015	>	else if ((xp = x.parent) == null) {
3016	>	x.red = false;
3017	>	return x;
3018	>	}
3019	>	else if (x.red) {
3020	>	x.red = false;
3021	>	return root;
3022	>	}
3023	>	else if ((xpl = xp.left) == x) {
3024	>	if ((xpr = xp.right) != null && xpr.red) {
3025	>	xpr.red = false;
3026	>	xp.red = true;
3027	>	root = rotateLeft(root, xp);
3028	>	xpr = (xp = x.parent) == null ? null : xp.right;
3029	>	}
3030	>	if (xpr == null)
3031	>	x = xp;
3032	>	else {
3033	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3034	>	if ((sr == null || !sr.red) &&
3035	>	(sl == null || !sl.red)) {
3036	>	xpr.red = true;
3037	>	x = xp;
3038	>	}
3039	>	else {
3040	>	if (sr == null || !sr.red) {
3041	>	if (sl != null)
3042	>	sl.red = false;
3043	>	xpr.red = true;
3044	>	root = rotateRight(root, xpr);
3045	>	xpr = (xp = x.parent) == null ?
3046	>	null : xp.right;
3047	>	}
3048	>	if (xpr != null) {
3049	>	xpr.red = (xp == null) ? false : xp.red;
3050	>	if ((sr = xpr.right) != null)
3051	>	sr.red = false;
3052	>	}
3053	>	if (xp != null) {
3054	>	xp.red = false;
3055	>	root = rotateLeft(root, xp);
3056	>	}
3057	>	x = root;
3058	>	}
3059	>	}
3060	>	}
3061	>	else { // symmetric
3062	>	if (xpl != null && xpl.red) {
3063	>	xpl.red = false;
3064	>	xp.red = true;
3065	>	root = rotateRight(root, xp);
3066	>	xpl = (xp = x.parent) == null ? null : xp.left;
3067	>	}
3068	>	if (xpl == null)
3069	>	x = xp;
3070	>	else {
3071	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3072	>	if ((sl == null || !sl.red) &&
3073	>	(sr == null || !sr.red)) {
3074	>	xpl.red = true;
3075	>	x = xp;
3076	>	}
3077	>	else {
3078	>	if (sl == null || !sl.red) {
3079	>	if (sr != null)
3080	>	sr.red = false;
3081	>	xpl.red = true;
3082	>	root = rotateLeft(root, xpl);
3083	>	xpl = (xp = x.parent) == null ?
3084	>	null : xp.left;
3085	>	}
3086	>	if (xpl != null) {
3087	>	xpl.red = (xp == null) ? false : xp.red;
3088	>	if ((sl = xpl.left) != null)
3089	>	sl.red = false;
3090	>	}
3091	>	if (xp != null) {
3092	>	xp.red = false;
3093	>	root = rotateRight(root, xp);
3094	>	}
3095	>	x = root;
3096	>	}
3097	>	}
3098	>	}
3099	>	}
3100	>	}
3101	>
3102	>	/**
3103	>	* Recursive invariant check
3104	>	*/
3105	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3106	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3107	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3108	>	if (tb != null && tb.next != t)
3109	>	return false;
3110	>	if (tn != null && tn.prev != t)
3111	>	return false;
3112	>	if (tp != null && t != tp.left && t != tp.right)
3113	>	return false;
3114	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3115	>	return false;
3116	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3117	>	return false;
3118	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3119	>	return false;
3120	>	if (tl != null && !checkInvariants(tl))
3121	>	return false;
3122	>	if (tr != null && !checkInvariants(tr))
3123	>	return false;
3124	>	return true;
3125	>	}
3126	>
3127	>	private static final sun.misc.Unsafe U;
3128	>	private static final long LOCKSTATE;
3129	>	static {
3130	>	try {
3131	>	U = sun.misc.Unsafe.getUnsafe();
3132	>	Class<?> k = TreeBin.class;
3133	>	LOCKSTATE = U.objectFieldOffset
3134	>	(k.getDeclaredField("lockState"));
3135	>	} catch (Exception e) {
3136	>	throw new Error(e);
3137	>	}
3138	>	}
3139	>	}
3140	>
3141	>	/* ----------------Table Traversal -------------- */
3142	>
3143	>	/**
3144	>	* Encapsulates traversal for methods such as containsValue; also
3145	>	* serves as a base class for other iterators and spliterators.
3146	>	*
3147	>	* Method advance visits once each still-valid node that was
3148	>	* reachable upon iterator construction. It might miss some that
3149	>	* were added to a bin after the bin was visited, which is OK wrt
3150	>	* consistency guarantees. Maintaining this property in the face
3151	>	* of possible ongoing resizes requires a fair amount of
3152	>	* bookkeeping state that is difficult to optimize away amidst
3153	>	* volatile accesses.  Even so, traversal maintains reasonable
3154	>	* throughput.
3155	>	*
3156	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3157	>	* However, if the table has been resized, then all future steps
3158	>	* must traverse both the bin at the current index as well as at
3159	>	* (index + baseSize); and so on for further resizings. To
3160	>	* paranoically cope with potential sharing by users of iterators
3161	>	* across threads, iteration terminates if a bounds checks fails
3162	>	* for a table read.
3163	>	*/
3164	>	static class Traverser<K,V> {
3165	>	Node<K,V>[] tab;        // current table; updated if resized
3166	>	Node<K,V> next;         // the next entry to use
3167	>	int index;              // index of bin to use next
3168	>	int baseIndex;          // current index of initial table
3169	>	int baseLimit;          // index bound for initial table
3170	>	final int baseSize;     // initial table size
3171	>
3172	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3173	>	this.tab = tab;
3174	>	this.baseSize = size;
3175	>	this.baseIndex = this.index = index;
3176	>	this.baseLimit = limit;
3177	>	this.next = null;
3178	>	}
3179	>
3180	>	/**
3181	>	* Advances if possible, returning next valid node, or null if none.
3182	>	*/
3183	>	final Node<K,V> advance() {
3184	>	Node<K,V> e;
3185	>	if ((e = next) != null)
3186	>	e = e.next;
3187	>	for (;;) {
3188	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3189	>	if (e != null)
3190	>	return next = e;
3191	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3192	>	(n = t.length) <= (i = index) || i < 0)
3193	>	return next = null;
3194	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
3195	>	if (e instanceof ForwardingNode) {
3196	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3197	>	e = null;
3198	>	continue;
3199	>	}
3200	>	else if (e instanceof TreeBin)
3201	>	e = ((TreeBin<K,V>)e).first;
3202	>	else
3203	>	e = null;
3204	>	}
3205	>	if ((index += baseSize) >= n)
3206	>	index = ++baseIndex;    // visit upper slots if present
3207	>	}
3208	>	}
3209	>	}
3210	>
3211	>	/**
3212	>	* Base of key, value, and entry Iterators. Adds fields to
3213	>	* Traverser to support iterator.remove
3214	>	*/
3215	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3216	>	final ConcurrentHashMap<K,V> map;
3217	>	Node<K,V> lastReturned;
3218	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3219	>	ConcurrentHashMap<K,V> map) {
3220	>	super(tab, size, index, limit);
3221	>	this.map = map;
3222		advance();
1101	–	return lastReturned;
3223		}
3224
3225	<	public void remove() {
3226	<	if (lastReturned == null)
3225	>	public final boolean hasNext() { return next != null; }
3226	>	public final boolean hasMoreElements() { return next != null; }
3227	>
3228	>	public final void remove() {
3229	>	Node<K,V> p;
3230	>	if ((p = lastReturned) == null)
3231		throw new IllegalStateException();
1107	–	ConcurrentHashMap.this.remove(lastReturned.key);
3232		lastReturned = null;
3233	+	map.replaceNode(p.key, null, null);
3234		}
3235		}
3236
3237	<	final class KeyIterator
3238	<	extends HashIterator
3239	<	implements Iterator<K>, Enumeration<K>
3240	<	{
3241	<	public K next()        { return super.nextEntry().key; }
3242	<	public K nextElement() { return super.nextEntry().key; }
3237	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3238	>	implements Iterator<K>, Enumeration<K> {
3239	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3240	>	ConcurrentHashMap<K,V> map) {
3241	>	super(tab, index, size, limit, map);
3242	>	}
3243	>
3244	>	public final K next() {
3245	>	Node<K,V> p;
3246	>	if ((p = next) == null)
3247	>	throw new NoSuchElementException();
3248	>	K k = p.key;
3249	>	lastReturned = p;
3250	>	advance();
3251	>	return k;
3252	>	}
3253	>
3254	>	public final K nextElement() { return next(); }
3255		}
3256
3257	<	final class ValueIterator
3258	<	extends HashIterator
3259	<	implements Iterator<V>, Enumeration<V>
3260	<	{
3261	<	public V next()        { return super.nextEntry().value; }
3262	<	public V nextElement() { return super.nextEntry().value; }
3257	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3258	>	implements Iterator<V>, Enumeration<V> {
3259	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3260	>	ConcurrentHashMap<K,V> map) {
3261	>	super(tab, index, size, limit, map);
3262	>	}
3263	>
3264	>	public final V next() {
3265	>	Node<K,V> p;
3266	>	if ((p = next) == null)
3267	>	throw new NoSuchElementException();
3268	>	V v = p.val;
3269	>	lastReturned = p;
3270	>	advance();
3271	>	return v;
3272	>	}
3273	>
3274	>	public final V nextElement() { return next(); }
3275	>	}
3276	>
3277	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3278	>	implements Iterator<Map.Entry<K,V>> {
3279	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3280	>	ConcurrentHashMap<K,V> map) {
3281	>	super(tab, index, size, limit, map);
3282	>	}
3283	>
3284	>	public final Map.Entry<K,V> next() {
3285	>	Node<K,V> p;
3286	>	if ((p = next) == null)
3287	>	throw new NoSuchElementException();
3288	>	K k = p.key;
3289	>	V v = p.val;
3290	>	lastReturned = p;
3291	>	advance();
3292	>	return new MapEntry<K,V>(k, v, map);
3293	>	}
3294		}
3295
3296		/**
3297	<	* Custom Entry class used by EntryIterator.next(), that relays
1130	<	* setValue changes to the underlying map.
3297	>	* Exported Entry for EntryIterator
3298		*/
3299	<	final class WriteThroughEntry
3300	<	extends AbstractMap.SimpleEntry<K,V>
3301	<	{
3302	<	WriteThroughEntry(K k, V v) {
3303	<	super(k,v);
3299	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3300	>	final K key; // non-null
3301	>	V val;       // non-null
3302	>	final ConcurrentHashMap<K,V> map;
3303	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3304	>	this.key = key;
3305	>	this.val = val;
3306	>	this.map = map;
3307	>	}
3308	>	public K getKey()        { return key; }
3309	>	public V getValue()      { return val; }
3310	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3311	>	public String toString() { return key + "=" + val; }
3312	>
3313	>	public boolean equals(Object o) {
3314	>	Object k, v; Map.Entry<?,?> e;
3315	>	return ((o instanceof Map.Entry) &&
3316	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3317	>	(v = e.getValue()) != null &&
3318	>	(k == key || k.equals(key)) &&
3319	>	(v == val || v.equals(val)));
3320		}
3321
3322		/**
3323	<	* Set our entry's value and write through to the map. The
3324	<	* value to return is somewhat arbitrary here. Since a
3325	<	* WriteThroughEntry does not necessarily track asynchronous
3326	<	* changes, the most recent "previous" value could be
3327	<	* different from what we return (or could even have been
3328	<	* removed in which case the put will re-establish). We do not
1146	<	* and cannot guarantee more.
3323	>	* Sets our entry's value and writes through to the map. The
3324	>	* value to return is somewhat arbitrary here. Since we do not
3325	>	* necessarily track asynchronous changes, the most recent
3326	>	* "previous" value could be different from what we return (or
3327	>	* could even have been removed, in which case the put will
3328	>	* re-establish). We do not and cannot guarantee more.
3329		*/
3330	<	public V setValue(V value) {
3330	>	public V setValue(V value) {
3331		if (value == null) throw new NullPointerException();
3332	<	V v = super.setValue(value);
3333	<	ConcurrentHashMap.this.put(getKey(), value);
3332	>	V v = val;
3333	>	val = value;
3334	>	map.put(key, value);
3335		return v;
3336		}
3337		}
3338
3339	<	final class EntryIterator
3340	<	extends HashIterator
3341	<	implements Iterator<Entry<K,V>>
3342	<	{
3343	<	public Map.Entry<K,V> next() {
3344	<	HashEntry<K,V> e = super.nextEntry();
3345	<	return new WriteThroughEntry(e.key, e.value);
3339	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3340	>	implements Spliterator<K> {
3341	>	long est;               // size estimate
3342	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3343	>	long est) {
3344	>	super(tab, size, index, limit);
3345	>	this.est = est;
3346	>	}
3347	>
3348	>	public Spliterator<K> trySplit() {
3349	>	int i, f, h;
3350	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3351	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3352	>	f, est >>>= 1);
3353	>	}
3354	>
3355	>	public void forEachRemaining(Consumer<? super K> action) {
3356	>	if (action == null) throw new NullPointerException();
3357	>	for (Node<K,V> p; (p = advance()) != null;)
3358	>	action.accept(p.key);
3359	>	}
3360	>
3361	>	public boolean tryAdvance(Consumer<? super K> action) {
3362	>	if (action == null) throw new NullPointerException();
3363	>	Node<K,V> p;
3364	>	if ((p = advance()) == null)
3365	>	return false;
3366	>	action.accept(p.key);
3367	>	return true;
3368	>	}
3369	>
3370	>	public long estimateSize() { return est; }
3371	>
3372	>	public int characteristics() {
3373	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3374	>	Spliterator.NONNULL;
3375		}
3376		}
3377
3378	<	final class KeySet extends AbstractSet<K> {
3379	<	public Iterator<K> iterator() {
3380	<	return new KeyIterator();
3378	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3379	>	implements Spliterator<V> {
3380	>	long est;               // size estimate
3381	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3382	>	long est) {
3383	>	super(tab, size, index, limit);
3384	>	this.est = est;
3385	>	}
3386	>
3387	>	public Spliterator<V> trySplit() {
3388	>	int i, f, h;
3389	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3390	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3391	>	f, est >>>= 1);
3392	>	}
3393	>
3394	>	public void forEachRemaining(Consumer<? super V> action) {
3395	>	if (action == null) throw new NullPointerException();
3396	>	for (Node<K,V> p; (p = advance()) != null;)
3397	>	action.accept(p.val);
3398	>	}
3399	>
3400	>	public boolean tryAdvance(Consumer<? super V> action) {
3401	>	if (action == null) throw new NullPointerException();
3402	>	Node<K,V> p;
3403	>	if ((p = advance()) == null)
3404	>	return false;
3405	>	action.accept(p.val);
3406	>	return true;
3407		}
3408	<	public int size() {
3409	<	return ConcurrentHashMap.this.size();
3408	>
3409	>	public long estimateSize() { return est; }
3410	>
3411	>	public int characteristics() {
3412	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3413		}
3414	<	public boolean contains(Object o) {
3415	<	return ConcurrentHashMap.this.containsKey(o);
3414	>	}
3415	>
3416	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3417	>	implements Spliterator<Map.Entry<K,V>> {
3418	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3419	>	long est;               // size estimate
3420	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3421	>	long est, ConcurrentHashMap<K,V> map) {
3422	>	super(tab, size, index, limit);
3423	>	this.map = map;
3424	>	this.est = est;
3425	>	}
3426	>
3427	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3428	>	int i, f, h;
3429	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3430	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3431	>	f, est >>>= 1, map);
3432	>	}
3433	>
3434	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3435	>	if (action == null) throw new NullPointerException();
3436	>	for (Node<K,V> p; (p = advance()) != null; )
3437	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3438	>	}
3439	>
3440	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3441	>	if (action == null) throw new NullPointerException();
3442	>	Node<K,V> p;
3443	>	if ((p = advance()) == null)
3444	>	return false;
3445	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3446	>	return true;
3447		}
3448	<	public boolean remove(Object o) {
3449	<	return ConcurrentHashMap.this.remove(o) != null;
3448	>
3449	>	public long estimateSize() { return est; }
3450	>
3451	>	public int characteristics() {
3452	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3453	>	Spliterator.NONNULL;
3454	>	}
3455	>	}
3456	>
3457	>	// Parallel bulk operations
3458	>
3459	>	/**
3460	>	* Computes initial batch value for bulk tasks. The returned value
3461	>	* is approximately exp2 of the number of times (minus one) to
3462	>	* split task by two before executing leaf action. This value is
3463	>	* faster to compute and more convenient to use as a guide to
3464	>	* splitting than is the depth, since it is used while dividing by
3465	>	* two anyway.
3466	>	*/
3467	>	final int batchFor(long b) {
3468	>	long n;
3469	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3470	>	return 0;
3471	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3472	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3473	>	}
3474	>
3475	>	/**
3476	>	* Performs the given action for each (key, value).
3477	>	*
3478	>	* @param parallelismThreshold the (estimated) number of elements
3479	>	* needed for this operation to be executed in parallel
3480	>	* @param action the action
3481	>	* @since 1.8
3482	>	*/
3483	>	public void forEach(long parallelismThreshold,
3484	>	BiConsumer<? super K,? super V> action) {
3485	>	if (action == null) throw new NullPointerException();
3486	>	new ForEachMappingTask<K,V>
3487	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3488	>	action).invoke();
3489	>	}
3490	>
3491	>	/**
3492	>	* Performs the given action for each non-null transformation
3493	>	* of each (key, value).
3494	>	*
3495	>	* @param parallelismThreshold the (estimated) number of elements
3496	>	* needed for this operation to be executed in parallel
3497	>	* @param transformer a function returning the transformation
3498	>	* for an element, or null if there is no transformation (in
3499	>	* which case the action is not applied)
3500	>	* @param action the action
3501	>	* @since 1.8
3502	>	*/
3503	>	public <U> void forEach(long parallelismThreshold,
3504	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3505	>	Consumer<? super U> action) {
3506	>	if (transformer == null || action == null)
3507	>	throw new NullPointerException();
3508	>	new ForEachTransformedMappingTask<K,V,U>
3509	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3510	>	transformer, action).invoke();
3511	>	}
3512	>
3513	>	/**
3514	>	* Returns a non-null result from applying the given search
3515	>	* function on each (key, value), or null if none.  Upon
3516	>	* success, further element processing is suppressed and the
3517	>	* results of any other parallel invocations of the search
3518	>	* function are ignored.
3519	>	*
3520	>	* @param parallelismThreshold the (estimated) number of elements
3521	>	* needed for this operation to be executed in parallel
3522	>	* @param searchFunction a function returning a non-null
3523	>	* result on success, else null
3524	>	* @return a non-null result from applying the given search
3525	>	* function on each (key, value), or null if none
3526	>	* @since 1.8
3527	>	*/
3528	>	public <U> U search(long parallelismThreshold,
3529	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3530	>	if (searchFunction == null) throw new NullPointerException();
3531	>	return new SearchMappingsTask<K,V,U>
3532	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3533	>	searchFunction, new AtomicReference<U>()).invoke();
3534	>	}
3535	>
3536	>	/**
3537	>	* Returns the result of accumulating the given transformation
3538	>	* of all (key, value) pairs using the given reducer to
3539	>	* combine values, or null if none.
3540	>	*
3541	>	* @param parallelismThreshold the (estimated) number of elements
3542	>	* needed for this operation to be executed in parallel
3543	>	* @param transformer a function returning the transformation
3544	>	* for an element, or null if there is no transformation (in
3545	>	* which case it is not combined)
3546	>	* @param reducer a commutative associative combining function
3547	>	* @return the result of accumulating the given transformation
3548	>	* of all (key, value) pairs
3549	>	* @since 1.8
3550	>	*/
3551	>	public <U> U reduce(long parallelismThreshold,
3552	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3553	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3554	>	if (transformer == null || reducer == null)
3555	>	throw new NullPointerException();
3556	>	return new MapReduceMappingsTask<K,V,U>
3557	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3558	>	null, transformer, reducer).invoke();
3559	>	}
3560	>
3561	>	/**
3562	>	* Returns the result of accumulating the given transformation
3563	>	* of all (key, value) pairs using the given reducer to
3564	>	* combine values, and the given basis as an identity value.
3565	>	*
3566	>	* @param parallelismThreshold the (estimated) number of elements
3567	>	* needed for this operation to be executed in parallel
3568	>	* @param transformer a function returning the transformation
3569	>	* for an element
3570	>	* @param basis the identity (initial default value) for the reduction
3571	>	* @param reducer a commutative associative combining function
3572	>	* @return the result of accumulating the given transformation
3573	>	* of all (key, value) pairs
3574	>	* @since 1.8
3575	>	*/
3576	>	public double reduceToDoubleIn(long parallelismThreshold,
3577	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3578	>	double basis,
3579	>	DoubleBinaryOperator reducer) {
3580	>	if (transformer == null || reducer == null)
3581	>	throw new NullPointerException();
3582	>	return new MapReduceMappingsToDoubleTask<K,V>
3583	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3584	>	null, transformer, basis, reducer).invoke();
3585	>	}
3586	>
3587	>	/**
3588	>	* Returns the result of accumulating the given transformation
3589	>	* of all (key, value) pairs using the given reducer to
3590	>	* combine values, and the given basis as an identity value.
3591	>	*
3592	>	* @param parallelismThreshold the (estimated) number of elements
3593	>	* needed for this operation to be executed in parallel
3594	>	* @param transformer a function returning the transformation
3595	>	* for an element
3596	>	* @param basis the identity (initial default value) for the reduction
3597	>	* @param reducer a commutative associative combining function
3598	>	* @return the result of accumulating the given transformation
3599	>	* of all (key, value) pairs
3600	>	* @since 1.8
3601	>	*/
3602	>	public long reduceToLong(long parallelismThreshold,
3603	>	ToLongBiFunction<? super K, ? super V> transformer,
3604	>	long basis,
3605	>	LongBinaryOperator reducer) {
3606	>	if (transformer == null || reducer == null)
3607	>	throw new NullPointerException();
3608	>	return new MapReduceMappingsToLongTask<K,V>
3609	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3610	>	null, transformer, basis, reducer).invoke();
3611	>	}
3612	>
3613	>	/**
3614	>	* Returns the result of accumulating the given transformation
3615	>	* of all (key, value) pairs using the given reducer to
3616	>	* combine values, and the given basis as an identity value.
3617	>	*
3618	>	* @param parallelismThreshold the (estimated) number of elements
3619	>	* needed for this operation to be executed in parallel
3620	>	* @param transformer a function returning the transformation
3621	>	* for an element
3622	>	* @param basis the identity (initial default value) for the reduction
3623	>	* @param reducer a commutative associative combining function
3624	>	* @return the result of accumulating the given transformation
3625	>	* of all (key, value) pairs
3626	>	* @since 1.8
3627	>	*/
3628	>	public int reduceToInt(long parallelismThreshold,
3629	>	ToIntBiFunction<? super K, ? super V> transformer,
3630	>	int basis,
3631	>	IntBinaryOperator reducer) {
3632	>	if (transformer == null || reducer == null)
3633	>	throw new NullPointerException();
3634	>	return new MapReduceMappingsToIntTask<K,V>
3635	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3636	>	null, transformer, basis, reducer).invoke();
3637	>	}
3638	>
3639	>	/**
3640	>	* Performs the given action for each key.
3641	>	*
3642	>	* @param parallelismThreshold the (estimated) number of elements
3643	>	* needed for this operation to be executed in parallel
3644	>	* @param action the action
3645	>	* @since 1.8
3646	>	*/
3647	>	public void forEachKey(long parallelismThreshold,
3648	>	Consumer<? super K> action) {
3649	>	if (action == null) throw new NullPointerException();
3650	>	new ForEachKeyTask<K,V>
3651	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3652	>	action).invoke();
3653	>	}
3654	>
3655	>	/**
3656	>	* Performs the given action for each non-null transformation
3657	>	* of each key.
3658	>	*
3659	>	* @param parallelismThreshold the (estimated) number of elements
3660	>	* needed for this operation to be executed in parallel
3661	>	* @param transformer a function returning the transformation
3662	>	* for an element, or null if there is no transformation (in
3663	>	* which case the action is not applied)
3664	>	* @param action the action
3665	>	* @since 1.8
3666	>	*/
3667	>	public <U> void forEachKey(long parallelismThreshold,
3668	>	Function<? super K, ? extends U> transformer,
3669	>	Consumer<? super U> action) {
3670	>	if (transformer == null || action == null)
3671	>	throw new NullPointerException();
3672	>	new ForEachTransformedKeyTask<K,V,U>
3673	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3674	>	transformer, action).invoke();
3675	>	}
3676	>
3677	>	/**
3678	>	* Returns a non-null result from applying the given search
3679	>	* function on each key, or null if none. Upon success,
3680	>	* further element processing is suppressed and the results of
3681	>	* any other parallel invocations of the search function are
3682	>	* ignored.
3683	>	*
3684	>	* @param parallelismThreshold the (estimated) number of elements
3685	>	* needed for this operation to be executed in parallel
3686	>	* @param searchFunction a function returning a non-null
3687	>	* result on success, else null
3688	>	* @return a non-null result from applying the given search
3689	>	* function on each key, or null if none
3690	>	* @since 1.8
3691	>	*/
3692	>	public <U> U searchKeys(long parallelismThreshold,
3693	>	Function<? super K, ? extends U> searchFunction) {
3694	>	if (searchFunction == null) throw new NullPointerException();
3695	>	return new SearchKeysTask<K,V,U>
3696	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3697	>	searchFunction, new AtomicReference<U>()).invoke();
3698	>	}
3699	>
3700	>	/**
3701	>	* Returns the result of accumulating all keys using the given
3702	>	* reducer to combine values, or null if none.
3703	>	*
3704	>	* @param parallelismThreshold the (estimated) number of elements
3705	>	* needed for this operation to be executed in parallel
3706	>	* @param reducer a commutative associative combining function
3707	>	* @return the result of accumulating all keys using the given
3708	>	* reducer to combine values, or null if none
3709	>	* @since 1.8
3710	>	*/
3711	>	public K reduceKeys(long parallelismThreshold,
3712	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3713	>	if (reducer == null) throw new NullPointerException();
3714	>	return new ReduceKeysTask<K,V>
3715	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3716	>	null, reducer).invoke();
3717	>	}
3718	>
3719	>	/**
3720	>	* Returns the result of accumulating the given transformation
3721	>	* of all keys using the given reducer to combine values, or
3722	>	* null if none.
3723	>	*
3724	>	* @param parallelismThreshold the (estimated) number of elements
3725	>	* needed for this operation to be executed in parallel
3726	>	* @param transformer a function returning the transformation
3727	>	* for an element, or null if there is no transformation (in
3728	>	* which case it is not combined)
3729	>	* @param reducer a commutative associative combining function
3730	>	* @return the result of accumulating the given transformation
3731	>	* of all keys
3732	>	* @since 1.8
3733	>	*/
3734	>	public <U> U reduceKeys(long parallelismThreshold,
3735	>	Function<? super K, ? extends U> transformer,
3736	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3737	>	if (transformer == null || reducer == null)
3738	>	throw new NullPointerException();
3739	>	return new MapReduceKeysTask<K,V,U>
3740	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3741	>	null, transformer, reducer).invoke();
3742	>	}
3743	>
3744	>	/**
3745	>	* Returns the result of accumulating the given transformation
3746	>	* of all keys using the given reducer to combine values, and
3747	>	* the given basis as an identity value.
3748	>	*
3749	>	* @param parallelismThreshold the (estimated) number of elements
3750	>	* needed for this operation to be executed in parallel
3751	>	* @param transformer a function returning the transformation
3752	>	* for an element
3753	>	* @param basis the identity (initial default value) for the reduction
3754	>	* @param reducer a commutative associative combining function
3755	>	* @return the result of accumulating the given transformation
3756	>	* of all keys
3757	>	* @since 1.8
3758	>	*/
3759	>	public double reduceKeysToDouble(long parallelismThreshold,
3760	>	ToDoubleFunction<? super K> transformer,
3761	>	double basis,
3762	>	DoubleBinaryOperator reducer) {
3763	>	if (transformer == null || reducer == null)
3764	>	throw new NullPointerException();
3765	>	return new MapReduceKeysToDoubleTask<K,V>
3766	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3767	>	null, transformer, basis, reducer).invoke();
3768	>	}
3769	>
3770	>	/**
3771	>	* Returns the result of accumulating the given transformation
3772	>	* of all keys using the given reducer to combine values, and
3773	>	* the given basis as an identity value.
3774	>	*
3775	>	* @param parallelismThreshold the (estimated) number of elements
3776	>	* needed for this operation to be executed in parallel
3777	>	* @param transformer a function returning the transformation
3778	>	* for an element
3779	>	* @param basis the identity (initial default value) for the reduction
3780	>	* @param reducer a commutative associative combining function
3781	>	* @return the result of accumulating the given transformation
3782	>	* of all keys
3783	>	* @since 1.8
3784	>	*/
3785	>	public long reduceKeysToLong(long parallelismThreshold,
3786	>	ToLongFunction<? super K> transformer,
3787	>	long basis,
3788	>	LongBinaryOperator reducer) {
3789	>	if (transformer == null || reducer == null)
3790	>	throw new NullPointerException();
3791	>	return new MapReduceKeysToLongTask<K,V>
3792	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3793	>	null, transformer, basis, reducer).invoke();
3794	>	}
3795	>
3796	>	/**
3797	>	* Returns the result of accumulating the given transformation
3798	>	* of all keys using the given reducer to combine values, and
3799	>	* the given basis as an identity value.
3800	>	*
3801	>	* @param parallelismThreshold the (estimated) number of elements
3802	>	* needed for this operation to be executed in parallel
3803	>	* @param transformer a function returning the transformation
3804	>	* for an element
3805	>	* @param basis the identity (initial default value) for the reduction
3806	>	* @param reducer a commutative associative combining function
3807	>	* @return the result of accumulating the given transformation
3808	>	* of all keys
3809	>	* @since 1.8
3810	>	*/
3811	>	public int reduceKeysToInt(long parallelismThreshold,
3812	>	ToIntFunction<? super K> transformer,
3813	>	int basis,
3814	>	IntBinaryOperator reducer) {
3815	>	if (transformer == null || reducer == null)
3816	>	throw new NullPointerException();
3817	>	return new MapReduceKeysToIntTask<K,V>
3818	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3819	>	null, transformer, basis, reducer).invoke();
3820	>	}
3821	>
3822	>	/**
3823	>	* Performs the given action for each value.
3824	>	*
3825	>	* @param parallelismThreshold the (estimated) number of elements
3826	>	* needed for this operation to be executed in parallel
3827	>	* @param action the action
3828	>	* @since 1.8
3829	>	*/
3830	>	public void forEachValue(long parallelismThreshold,
3831	>	Consumer<? super V> action) {
3832	>	if (action == null)
3833	>	throw new NullPointerException();
3834	>	new ForEachValueTask<K,V>
3835	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3836	>	action).invoke();
3837	>	}
3838	>
3839	>	/**
3840	>	* Performs the given action for each non-null transformation
3841	>	* of each value.
3842	>	*
3843	>	* @param parallelismThreshold the (estimated) number of elements
3844	>	* needed for this operation to be executed in parallel
3845	>	* @param transformer a function returning the transformation
3846	>	* for an element, or null if there is no transformation (in
3847	>	* which case the action is not applied)
3848	>	* @param action the action
3849	>	* @since 1.8
3850	>	*/
3851	>	public <U> void forEachValue(long parallelismThreshold,
3852	>	Function<? super V, ? extends U> transformer,
3853	>	Consumer<? super U> action) {
3854	>	if (transformer == null || action == null)
3855	>	throw new NullPointerException();
3856	>	new ForEachTransformedValueTask<K,V,U>
3857	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3858	>	transformer, action).invoke();
3859	>	}
3860	>
3861	>	/**
3862	>	* Returns a non-null result from applying the given search
3863	>	* function on each value, or null if none.  Upon success,
3864	>	* further element processing is suppressed and the results of
3865	>	* any other parallel invocations of the search function are
3866	>	* ignored.
3867	>	*
3868	>	* @param parallelismThreshold the (estimated) number of elements
3869	>	* needed for this operation to be executed in parallel
3870	>	* @param searchFunction a function returning a non-null
3871	>	* result on success, else null
3872	>	* @return a non-null result from applying the given search
3873	>	* function on each value, or null if none
3874	>	* @since 1.8
3875	>	*/
3876	>	public <U> U searchValues(long parallelismThreshold,
3877	>	Function<? super V, ? extends U> searchFunction) {
3878	>	if (searchFunction == null) throw new NullPointerException();
3879	>	return new SearchValuesTask<K,V,U>
3880	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3881	>	searchFunction, new AtomicReference<U>()).invoke();
3882	>	}
3883	>
3884	>	/**
3885	>	* Returns the result of accumulating all values using the
3886	>	* given reducer to combine values, or null if none.
3887	>	*
3888	>	* @param parallelismThreshold the (estimated) number of elements
3889	>	* needed for this operation to be executed in parallel
3890	>	* @param reducer a commutative associative combining function
3891	>	* @return the result of accumulating all values
3892	>	* @since 1.8
3893	>	*/
3894	>	public V reduceValues(long parallelismThreshold,
3895	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
3896	>	if (reducer == null) throw new NullPointerException();
3897	>	return new ReduceValuesTask<K,V>
3898	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3899	>	null, reducer).invoke();
3900	>	}
3901	>
3902	>	/**
3903	>	* Returns the result of accumulating the given transformation
3904	>	* of all values using the given reducer to combine values, or
3905	>	* null if none.
3906	>	*
3907	>	* @param parallelismThreshold the (estimated) number of elements
3908	>	* needed for this operation to be executed in parallel
3909	>	* @param transformer a function returning the transformation
3910	>	* for an element, or null if there is no transformation (in
3911	>	* which case it is not combined)
3912	>	* @param reducer a commutative associative combining function
3913	>	* @return the result of accumulating the given transformation
3914	>	* of all values
3915	>	* @since 1.8
3916	>	*/
3917	>	public <U> U reduceValues(long parallelismThreshold,
3918	>	Function<? super V, ? extends U> transformer,
3919	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3920	>	if (transformer == null || reducer == null)
3921	>	throw new NullPointerException();
3922	>	return new MapReduceValuesTask<K,V,U>
3923	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3924	>	null, transformer, reducer).invoke();
3925	>	}
3926	>
3927	>	/**
3928	>	* Returns the result of accumulating the given transformation
3929	>	* of all values using the given reducer to combine values,
3930	>	* and the given basis as an identity value.
3931	>	*
3932	>	* @param parallelismThreshold the (estimated) number of elements
3933	>	* needed for this operation to be executed in parallel
3934	>	* @param transformer a function returning the transformation
3935	>	* for an element
3936	>	* @param basis the identity (initial default value) for the reduction
3937	>	* @param reducer a commutative associative combining function
3938	>	* @return the result of accumulating the given transformation
3939	>	* of all values
3940	>	* @since 1.8
3941	>	*/
3942	>	public double reduceValuesToDouble(long parallelismThreshold,
3943	>	ToDoubleFunction<? super V> transformer,
3944	>	double basis,
3945	>	DoubleBinaryOperator reducer) {
3946	>	if (transformer == null || reducer == null)
3947	>	throw new NullPointerException();
3948	>	return new MapReduceValuesToDoubleTask<K,V>
3949	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3950	>	null, transformer, basis, reducer).invoke();
3951	>	}
3952	>
3953	>	/**
3954	>	* Returns the result of accumulating the given transformation
3955	>	* of all values using the given reducer to combine values,
3956	>	* and the given basis as an identity value.
3957	>	*
3958	>	* @param parallelismThreshold the (estimated) number of elements
3959	>	* needed for this operation to be executed in parallel
3960	>	* @param transformer a function returning the transformation
3961	>	* for an element
3962	>	* @param basis the identity (initial default value) for the reduction
3963	>	* @param reducer a commutative associative combining function
3964	>	* @return the result of accumulating the given transformation
3965	>	* of all values
3966	>	* @since 1.8
3967	>	*/
3968	>	public long reduceValuesToLong(long parallelismThreshold,
3969	>	ToLongFunction<? super V> transformer,
3970	>	long basis,
3971	>	LongBinaryOperator reducer) {
3972	>	if (transformer == null || reducer == null)
3973	>	throw new NullPointerException();
3974	>	return new MapReduceValuesToLongTask<K,V>
3975	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3976	>	null, transformer, basis, reducer).invoke();
3977	>	}
3978	>
3979	>	/**
3980	>	* Returns the result of accumulating the given transformation
3981	>	* of all values using the given reducer to combine values,
3982	>	* and the given basis as an identity value.
3983	>	*
3984	>	* @param parallelismThreshold the (estimated) number of elements
3985	>	* needed for this operation to be executed in parallel
3986	>	* @param transformer a function returning the transformation
3987	>	* for an element
3988	>	* @param basis the identity (initial default value) for the reduction
3989	>	* @param reducer a commutative associative combining function
3990	>	* @return the result of accumulating the given transformation
3991	>	* of all values
3992	>	* @since 1.8
3993	>	*/
3994	>	public int reduceValuesToInt(long parallelismThreshold,
3995	>	ToIntFunction<? super V> transformer,
3996	>	int basis,
3997	>	IntBinaryOperator reducer) {
3998	>	if (transformer == null || reducer == null)
3999	>	throw new NullPointerException();
4000	>	return new MapReduceValuesToIntTask<K,V>
4001	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4002	>	null, transformer, basis, reducer).invoke();
4003	>	}
4004	>
4005	>	/**
4006	>	* Performs the given action for each entry.
4007	>	*
4008	>	* @param parallelismThreshold the (estimated) number of elements
4009	>	* needed for this operation to be executed in parallel
4010	>	* @param action the action
4011	>	* @since 1.8
4012	>	*/
4013	>	public void forEachEntry(long parallelismThreshold,
4014	>	Consumer<? super Map.Entry<K,V>> action) {
4015	>	if (action == null) throw new NullPointerException();
4016	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4017	>	action).invoke();
4018	>	}
4019	>
4020	>	/**
4021	>	* Performs the given action for each non-null transformation
4022	>	* of each entry.
4023	>	*
4024	>	* @param parallelismThreshold the (estimated) number of elements
4025	>	* needed for this operation to be executed in parallel
4026	>	* @param transformer a function returning the transformation
4027	>	* for an element, or null if there is no transformation (in
4028	>	* which case the action is not applied)
4029	>	* @param action the action
4030	>	* @since 1.8
4031	>	*/
4032	>	public <U> void forEachEntry(long parallelismThreshold,
4033	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4034	>	Consumer<? super U> action) {
4035	>	if (transformer == null || action == null)
4036	>	throw new NullPointerException();
4037	>	new ForEachTransformedEntryTask<K,V,U>
4038	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4039	>	transformer, action).invoke();
4040	>	}
4041	>
4042	>	/**
4043	>	* Returns a non-null result from applying the given search
4044	>	* function on each entry, or null if none.  Upon success,
4045	>	* further element processing is suppressed and the results of
4046	>	* any other parallel invocations of the search function are
4047	>	* ignored.
4048	>	*
4049	>	* @param parallelismThreshold the (estimated) number of elements
4050	>	* needed for this operation to be executed in parallel
4051	>	* @param searchFunction a function returning a non-null
4052	>	* result on success, else null
4053	>	* @return a non-null result from applying the given search
4054	>	* function on each entry, or null if none
4055	>	* @since 1.8
4056	>	*/
4057	>	public <U> U searchEntries(long parallelismThreshold,
4058	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4059	>	if (searchFunction == null) throw new NullPointerException();
4060	>	return new SearchEntriesTask<K,V,U>
4061	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4062	>	searchFunction, new AtomicReference<U>()).invoke();
4063	>	}
4064	>
4065	>	/**
4066	>	* Returns the result of accumulating all entries using the
4067	>	* given reducer to combine values, or null if none.
4068	>	*
4069	>	* @param parallelismThreshold the (estimated) number of elements
4070	>	* needed for this operation to be executed in parallel
4071	>	* @param reducer a commutative associative combining function
4072	>	* @return the result of accumulating all entries
4073	>	* @since 1.8
4074	>	*/
4075	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4076	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4077	>	if (reducer == null) throw new NullPointerException();
4078	>	return new ReduceEntriesTask<K,V>
4079	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4080	>	null, reducer).invoke();
4081	>	}
4082	>
4083	>	/**
4084	>	* Returns the result of accumulating the given transformation
4085	>	* of all entries using the given reducer to combine values,
4086	>	* 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 transformer a function returning the transformation
4091	>	* for an element, or null if there is no transformation (in
4092	>	* which case it is not combined)
4093	>	* @param reducer a commutative associative combining function
4094	>	* @return the result of accumulating the given transformation
4095	>	* of all entries
4096	>	* @since 1.8
4097	>	*/
4098	>	public <U> U reduceEntries(long parallelismThreshold,
4099	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4100	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4101	>	if (transformer == null || reducer == null)
4102	>	throw new NullPointerException();
4103	>	return new MapReduceEntriesTask<K,V,U>
4104	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4105	>	null, transformer, reducer).invoke();
4106	>	}
4107	>
4108	>	/**
4109	>	* Returns the result of accumulating the given transformation
4110	>	* of all entries using the given reducer to combine values,
4111	>	* and the given basis as an identity value.
4112	>	*
4113	>	* @param parallelismThreshold the (estimated) number of elements
4114	>	* needed for this operation to be executed in parallel
4115	>	* @param transformer a function returning the transformation
4116	>	* for an element
4117	>	* @param basis the identity (initial default value) for the reduction
4118	>	* @param reducer a commutative associative combining function
4119	>	* @return the result of accumulating the given transformation
4120	>	* of all entries
4121	>	* @since 1.8
4122	>	*/
4123	>	public double reduceEntriesToDouble(long parallelismThreshold,
4124	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4125	>	double basis,
4126	>	DoubleBinaryOperator reducer) {
4127	>	if (transformer == null || reducer == null)
4128	>	throw new NullPointerException();
4129	>	return new MapReduceEntriesToDoubleTask<K,V>
4130	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4131	>	null, transformer, basis, reducer).invoke();
4132	>	}
4133	>
4134	>	/**
4135	>	* Returns the result of accumulating the given transformation
4136	>	* of all entries using the given reducer to combine values,
4137	>	* and the given basis as an identity value.
4138	>	*
4139	>	* @param parallelismThreshold the (estimated) number of elements
4140	>	* needed for this operation to be executed in parallel
4141	>	* @param transformer a function returning the transformation
4142	>	* for an element
4143	>	* @param basis the identity (initial default value) for the reduction
4144	>	* @param reducer a commutative associative combining function
4145	>	* @return the result of accumulating the given transformation
4146	>	* of all entries
4147	>	* @since 1.8
4148	>	*/
4149	>	public long reduceEntriesToLong(long parallelismThreshold,
4150	>	ToLongFunction<Map.Entry<K,V>> transformer,
4151	>	long basis,
4152	>	LongBinaryOperator reducer) {
4153	>	if (transformer == null || reducer == null)
4154	>	throw new NullPointerException();
4155	>	return new MapReduceEntriesToLongTask<K,V>
4156	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4157	>	null, transformer, basis, reducer).invoke();
4158	>	}
4159	>
4160	>	/**
4161	>	* Returns the result of accumulating the given transformation
4162	>	* of all entries using the given reducer to combine values,
4163	>	* and the given basis as an identity value.
4164	>	*
4165	>	* @param parallelismThreshold the (estimated) number of elements
4166	>	* needed for this operation to be executed in parallel
4167	>	* @param transformer a function returning the transformation
4168	>	* for an element
4169	>	* @param basis the identity (initial default value) for the reduction
4170	>	* @param reducer a commutative associative combining function
4171	>	* @return the result of accumulating the given transformation
4172	>	* of all entries
4173	>	* @since 1.8
4174	>	*/
4175	>	public int reduceEntriesToInt(long parallelismThreshold,
4176	>	ToIntFunction<Map.Entry<K,V>> transformer,
4177	>	int basis,
4178	>	IntBinaryOperator reducer) {
4179	>	if (transformer == null || reducer == null)
4180	>	throw new NullPointerException();
4181	>	return new MapReduceEntriesToIntTask<K,V>
4182	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4183	>	null, transformer, basis, reducer).invoke();
4184	>	}
4185	>
4186	>
4187	>	/* ----------------Views -------------- */
4188	>
4189	>	/**
4190	>	* Base class for views.
4191	>	*/
4192	>	abstract static class CollectionView<K,V,E>
4193	>	implements Collection<E>, java.io.Serializable {
4194	>	private static final long serialVersionUID = 7249069246763182397L;
4195	>	final ConcurrentHashMap<K,V> map;
4196	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4197	>
4198	>	/**
4199	>	* Returns the map backing this view.
4200	>	*
4201	>	* @return the map backing this view
4202	>	*/
4203	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4204	>
4205	>	/**
4206	>	* Removes all of the elements from this view, by removing all
4207	>	* the mappings from the map backing this view.
4208	>	*/
4209	>	public final void clear()      { map.clear(); }
4210	>	public final int size()        { return map.size(); }
4211	>	public final boolean isEmpty() { return map.isEmpty(); }
4212	>
4213	>	// implementations below rely on concrete classes supplying these
4214	>	// abstract methods
4215	>	/**
4216	>	* Returns a "weakly consistent" iterator that will never
4217	>	* throw {@link ConcurrentModificationException}, and
4218	>	* guarantees to traverse elements as they existed upon
4219	>	* construction of the iterator, and may (but is not
4220	>	* guaranteed to) reflect any modifications subsequent to
4221	>	* construction.
4222	>	*/
4223	>	public abstract Iterator<E> iterator();
4224	>	public abstract boolean contains(Object o);
4225	>	public abstract boolean remove(Object o);
4226	>
4227	>	private static final String oomeMsg = "Required array size too large";
4228	>
4229	>	public final Object[] toArray() {
4230	>	long sz = map.mappingCount();
4231	>	if (sz > MAX_ARRAY_SIZE)
4232	>	throw new OutOfMemoryError(oomeMsg);
4233	>	int n = (int)sz;
4234	>	Object[] r = new Object[n];
4235	>	int i = 0;
4236	>	for (E e : this) {
4237	>	if (i == n) {
4238	>	if (n >= MAX_ARRAY_SIZE)
4239	>	throw new OutOfMemoryError(oomeMsg);
4240	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4241	>	n = MAX_ARRAY_SIZE;
4242	>	else
4243	>	n += (n >>> 1) + 1;
4244	>	r = Arrays.copyOf(r, n);
4245	>	}
4246	>	r[i++] = e;
4247	>	}
4248	>	return (i == n) ? r : Arrays.copyOf(r, i);
4249		}
4250	<	public void clear() {
4251	<	ConcurrentHashMap.this.clear();
4250	>
4251	>	@SuppressWarnings("unchecked")
4252	>	public final <T> T[] toArray(T[] a) {
4253	>	long sz = map.mappingCount();
4254	>	if (sz > MAX_ARRAY_SIZE)
4255	>	throw new OutOfMemoryError(oomeMsg);
4256	>	int m = (int)sz;
4257	>	T[] r = (a.length >= m) ? a :
4258	>	(T[])java.lang.reflect.Array
4259	>	.newInstance(a.getClass().getComponentType(), m);
4260	>	int n = r.length;
4261	>	int i = 0;
4262	>	for (E e : this) {
4263	>	if (i == n) {
4264	>	if (n >= MAX_ARRAY_SIZE)
4265	>	throw new OutOfMemoryError(oomeMsg);
4266	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4267	>	n = MAX_ARRAY_SIZE;
4268	>	else
4269	>	n += (n >>> 1) + 1;
4270	>	r = Arrays.copyOf(r, n);
4271	>	}
4272	>	r[i++] = (T)e;
4273	>	}
4274	>	if (a == r && i < n) {
4275	>	r[i] = null; // null-terminate
4276	>	return r;
4277	>	}
4278	>	return (i == n) ? r : Arrays.copyOf(r, i);
4279	>	}
4280	>
4281	>	/**
4282	>	* Returns a string representation of this collection.
4283	>	* The string representation consists of the string representations
4284	>	* of the collection's elements in the order they are returned by
4285	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4286	>	* Adjacent elements are separated by the characters {@code ", "}
4287	>	* (comma and space).  Elements are converted to strings as by
4288	>	* {@link String#valueOf(Object)}.
4289	>	*
4290	>	* @return a string representation of this collection
4291	>	*/
4292	>	public final String toString() {
4293	>	StringBuilder sb = new StringBuilder();
4294	>	sb.append('[');
4295	>	Iterator<E> it = iterator();
4296	>	if (it.hasNext()) {
4297	>	for (;;) {
4298	>	Object e = it.next();
4299	>	sb.append(e == this ? "(this Collection)" : e);
4300	>	if (!it.hasNext())
4301	>	break;
4302	>	sb.append(',').append(' ');
4303	>	}
4304	>	}
4305	>	return sb.append(']').toString();
4306		}
4307	+
4308	+	public final boolean containsAll(Collection<?> c) {
4309	+	if (c != this) {
4310	+	for (Object e : c) {
4311	+	if (e == null || !contains(e))
4312	+	return false;
4313	+	}
4314	+	}
4315	+	return true;
4316	+	}
4317	+
4318	+	public final boolean removeAll(Collection<?> c) {
4319	+	boolean modified = false;
4320	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4321	+	if (c.contains(it.next())) {
4322	+	it.remove();
4323	+	modified = true;
4324	+	}
4325	+	}
4326	+	return modified;
4327	+	}
4328	+
4329	+	public final boolean retainAll(Collection<?> c) {
4330	+	boolean modified = false;
4331	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4332	+	if (!c.contains(it.next())) {
4333	+	it.remove();
4334	+	modified = true;
4335	+	}
4336	+	}
4337	+	return modified;
4338	+	}
4339	+
4340		}
4341
4342	<	final class Values extends AbstractCollection<V> {
4343	<	public Iterator<V> iterator() {
4344	<	return new ValueIterator();
4342	>	/**
4343	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4344	>	* which additions may optionally be enabled by mapping to a
4345	>	* common value.  This class cannot be directly instantiated.
4346	>	* See {@link #keySet() keySet()},
4347	>	* {@link #keySet(Object) keySet(V)},
4348	>	* {@link #newKeySet() newKeySet()},
4349	>	* {@link #newKeySet(int) newKeySet(int)}.
4350	>	*
4351	>	* @since 1.8
4352	>	*/
4353	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4354	>	implements Set<K>, java.io.Serializable {
4355	>	private static final long serialVersionUID = 7249069246763182397L;
4356	>	private final V value;
4357	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4358	>	super(map);
4359	>	this.value = value;
4360		}
4361	<	public int size() {
4362	<	return ConcurrentHashMap.this.size();
4361	>
4362	>	/**
4363	>	* Returns the default mapped value for additions,
4364	>	* or {@code null} if additions are not supported.
4365	>	*
4366	>	* @return the default mapped value for additions, or {@code null}
4367	>	* if not supported
4368	>	*/
4369	>	public V getMappedValue() { return value; }
4370	>
4371	>	/**
4372	>	* {@inheritDoc}
4373	>	* @throws NullPointerException if the specified key is null
4374	>	*/
4375	>	public boolean contains(Object o) { return map.containsKey(o); }
4376	>
4377	>	/**
4378	>	* Removes the key from this map view, by removing the key (and its
4379	>	* corresponding value) from the backing map.  This method does
4380	>	* nothing if the key is not in the map.
4381	>	*
4382	>	* @param  o the key to be removed from the backing map
4383	>	* @return {@code true} if the backing map contained the specified key
4384	>	* @throws NullPointerException if the specified key is null
4385	>	*/
4386	>	public boolean remove(Object o) { return map.remove(o) != null; }
4387	>
4388	>	/**
4389	>	* @return an iterator over the keys of the backing map
4390	>	*/
4391	>	public Iterator<K> iterator() {
4392	>	Node<K,V>[] t;
4393	>	ConcurrentHashMap<K,V> m = map;
4394	>	int f = (t = m.table) == null ? 0 : t.length;
4395	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4396		}
4397	<	public boolean contains(Object o) {
4398	<	return ConcurrentHashMap.this.containsValue(o);
4397	>
4398	>	/**
4399	>	* Adds the specified key to this set view by mapping the key to
4400	>	* the default mapped value in the backing map, if defined.
4401	>	*
4402	>	* @param e key to be added
4403	>	* @return {@code true} if this set changed as a result of the call
4404	>	* @throws NullPointerException if the specified key is null
4405	>	* @throws UnsupportedOperationException if no default mapped value
4406	>	* for additions was provided
4407	>	*/
4408	>	public boolean add(K e) {
4409	>	V v;
4410	>	if ((v = value) == null)
4411	>	throw new UnsupportedOperationException();
4412	>	return map.putVal(e, v, true) == null;
4413		}
4414	<	public void clear() {
4415	<	ConcurrentHashMap.this.clear();
4414	>
4415	>	/**
4416	>	* Adds all of the elements in the specified collection to this set,
4417	>	* as if by calling {@link #add} on each one.
4418	>	*
4419	>	* @param c the elements to be inserted into this set
4420	>	* @return {@code true} if this set changed as a result of the call
4421	>	* @throws NullPointerException if the collection or any of its
4422	>	* elements are {@code null}
4423	>	* @throws UnsupportedOperationException if no default mapped value
4424	>	* for additions was provided
4425	>	*/
4426	>	public boolean addAll(Collection<? extends K> c) {
4427	>	boolean added = false;
4428	>	V v;
4429	>	if ((v = value) == null)
4430	>	throw new UnsupportedOperationException();
4431	>	for (K e : c) {
4432	>	if (map.putVal(e, v, true) == null)
4433	>	added = true;
4434	>	}
4435	>	return added;
4436	>	}
4437	>
4438	>	public int hashCode() {
4439	>	int h = 0;
4440	>	for (K e : this)
4441	>	h += e.hashCode();
4442	>	return h;
4443	>	}
4444	>
4445	>	public boolean equals(Object o) {
4446	>	Set<?> c;
4447	>	return ((o instanceof Set) &&
4448	>	((c = (Set<?>)o) == this ||
4449	>	(containsAll(c) && c.containsAll(this))));
4450	>	}
4451	>
4452	>	public Spliterator<K> spliterator() {
4453	>	Node<K,V>[] t;
4454	>	ConcurrentHashMap<K,V> m = map;
4455	>	long n = m.sumCount();
4456	>	int f = (t = m.table) == null ? 0 : t.length;
4457	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4458	>	}
4459	>
4460	>	public void forEach(Consumer<? super K> action) {
4461	>	if (action == null) throw new NullPointerException();
4462	>	Node<K,V>[] t;
4463	>	if ((t = map.table) != null) {
4464	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4465	>	for (Node<K,V> p; (p = it.advance()) != null; )
4466	>	action.accept(p.key);
4467	>	}
4468		}
4469		}
4470
4471	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4472	<	public Iterator<Map.Entry<K,V>> iterator() {
4473	<	return new EntryIterator();
4471	>	/**
4472	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4473	>	* values, in which additions are disabled. This class cannot be
4474	>	* directly instantiated. See {@link #values()}.
4475	>	*/
4476	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4477	>	implements Collection<V>, java.io.Serializable {
4478	>	private static final long serialVersionUID = 2249069246763182397L;
4479	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4480	>	public final boolean contains(Object o) {
4481	>	return map.containsValue(o);
4482	>	}
4483	>
4484	>	public final boolean remove(Object o) {
4485	>	if (o != null) {
4486	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4487	>	if (o.equals(it.next())) {
4488	>	it.remove();
4489	>	return true;
4490	>	}
4491	>	}
4492	>	}
4493	>	return false;
4494		}
4495	+
4496	+	public final Iterator<V> iterator() {
4497	+	ConcurrentHashMap<K,V> m = map;
4498	+	Node<K,V>[] t;
4499	+	int f = (t = m.table) == null ? 0 : t.length;
4500	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4501	+	}
4502	+
4503	+	public final boolean add(V e) {
4504	+	throw new UnsupportedOperationException();
4505	+	}
4506	+	public final boolean addAll(Collection<? extends V> c) {
4507	+	throw new UnsupportedOperationException();
4508	+	}
4509	+
4510	+	public Spliterator<V> spliterator() {
4511	+	Node<K,V>[] t;
4512	+	ConcurrentHashMap<K,V> m = map;
4513	+	long n = m.sumCount();
4514	+	int f = (t = m.table) == null ? 0 : t.length;
4515	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4516	+	}
4517	+
4518	+	public void forEach(Consumer<? super V> action) {
4519	+	if (action == null) throw new NullPointerException();
4520	+	Node<K,V>[] t;
4521	+	if ((t = map.table) != null) {
4522	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4523	+	for (Node<K,V> p; (p = it.advance()) != null; )
4524	+	action.accept(p.val);
4525	+	}
4526	+	}
4527	+	}
4528	+
4529	+	/**
4530	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4531	+	* entries.  This class cannot be directly instantiated. See
4532	+	* {@link #entrySet()}.
4533	+	*/
4534	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4535	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4536	+	private static final long serialVersionUID = 2249069246763182397L;
4537	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4538	+
4539		public boolean contains(Object o) {
4540	<	if (!(o instanceof Map.Entry))
4541	<	return false;
4542	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4543	<	V v = ConcurrentHashMap.this.get(e.getKey());
4544	<	return v != null && v.equals(e.getValue());
4540	>	Object k, v, r; Map.Entry<?,?> e;
4541	>	return ((o instanceof Map.Entry) &&
4542	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4543	>	(r = map.get(k)) != null &&
4544	>	(v = e.getValue()) != null &&
4545	>	(v == r || v.equals(r)));
4546		}
4547	+
4548		public boolean remove(Object o) {
4549	<	if (!(o instanceof Map.Entry))
4550	<	return false;
4551	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4552	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4549	>	Object k, v; Map.Entry<?,?> e;
4550	>	return ((o instanceof Map.Entry) &&
4551	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4552	>	(v = e.getValue()) != null &&
4553	>	map.remove(k, v));
4554		}
4555	<	public int size() {
4556	<	return ConcurrentHashMap.this.size();
4555	>
4556	>	/**
4557	>	* @return an iterator over the entries of the backing map
4558	>	*/
4559	>	public Iterator<Map.Entry<K,V>> iterator() {
4560	>	ConcurrentHashMap<K,V> m = map;
4561	>	Node<K,V>[] t;
4562	>	int f = (t = m.table) == null ? 0 : t.length;
4563	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4564		}
4565	<	public void clear() {
4566	<	ConcurrentHashMap.this.clear();
4565	>
4566	>	public boolean add(Entry<K,V> e) {
4567	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4568		}
4569	+
4570	+	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4571	+	boolean added = false;
4572	+	for (Entry<K,V> e : c) {
4573	+	if (add(e))
4574	+	added = true;
4575	+	}
4576	+	return added;
4577	+	}
4578	+
4579	+	public final int hashCode() {
4580	+	int h = 0;
4581	+	Node<K,V>[] t;
4582	+	if ((t = map.table) != null) {
4583	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4584	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
4585	+	h += p.hashCode();
4586	+	}
4587	+	}
4588	+	return h;
4589	+	}
4590	+
4591	+	public final boolean equals(Object o) {
4592	+	Set<?> c;
4593	+	return ((o instanceof Set) &&
4594	+	((c = (Set<?>)o) == this ||
4595	+	(containsAll(c) && c.containsAll(this))));
4596	+	}
4597	+
4598	+	public Spliterator<Map.Entry<K,V>> spliterator() {
4599	+	Node<K,V>[] t;
4600	+	ConcurrentHashMap<K,V> m = map;
4601	+	long n = m.sumCount();
4602	+	int f = (t = m.table) == null ? 0 : t.length;
4603	+	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4604	+	}
4605	+
4606	+	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4607	+	if (action == null) throw new NullPointerException();
4608	+	Node<K,V>[] t;
4609	+	if ((t = map.table) != null) {
4610	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4611	+	for (Node<K,V> p; (p = it.advance()) != null; )
4612	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4613	+	}
4614	+	}
4615	+
4616		}
4617
4618	<	/* ---------------- Serialization Support -------------- */
4618	>	// -------------------------------------------------------
4619
4620		/**
4621	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
4622	<	* 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.
4621	>	* Base class for bulk tasks. Repeats some fields and code from
4622	>	* class Traverser, because we need to subclass CountedCompleter.
4623		*/
4624	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4625	<	s.defaultWriteObject();
4624	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4625	>	Node<K,V>[] tab;        // same as Traverser
4626	>	Node<K,V> next;
4627	>	int index;
4628	>	int baseIndex;
4629	>	int baseLimit;
4630	>	final int baseSize;
4631	>	int batch;              // split control
4632	>
4633	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4634	>	super(par);
4635	>	this.batch = b;
4636	>	this.index = this.baseIndex = i;
4637	>	if ((this.tab = t) == null)
4638	>	this.baseSize = this.baseLimit = 0;
4639	>	else if (par == null)
4640	>	this.baseSize = this.baseLimit = t.length;
4641	>	else {
4642	>	this.baseLimit = f;
4643	>	this.baseSize = par.baseSize;
4644	>	}
4645	>	}
4646
4647	<	for (int k = 0; k < segments.length; ++k) {
4648	<	Segment<K,V> seg = segments[k];
4649	<	seg.lock();
4650	<	try {
4651	<	HashEntry<K,V>[] tab = seg.table;
4652	<	for (int i = 0; i < tab.length; ++i) {
4653	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
4654	<	s.writeObject(e.key);
4655	<	s.writeObject(e.value);
4647	>	/**
4648	>	* Same as Traverser version
4649	>	*/
4650	>	final Node<K,V> advance() {
4651	>	Node<K,V> e;
4652	>	if ((e = next) != null)
4653	>	e = e.next;
4654	>	for (;;) {
4655	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4656	>	if (e != null)
4657	>	return next = e;
4658	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4659	>	(n = t.length) <= (i = index) || i < 0)
4660	>	return next = null;
4661	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4662	>	if (e instanceof ForwardingNode) {
4663	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4664	>	e = null;
4665	>	continue;
4666		}
4667	+	else if (e instanceof TreeBin)
4668	+	e = ((TreeBin<K,V>)e).first;
4669	+	else
4670	+	e = null;
4671		}
4672	<	} finally {
4673	<	seg.unlock();
4672	>	if ((index += baseSize) >= n)
4673	>	index = ++baseIndex;    // visit upper slots if present
4674		}
4675		}
1253	–	s.writeObject(null);
1254	–	s.writeObject(null);
4676		}
4677
4678	<	/**
4679	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
4680	<	* stream (i.e., deserialize it).
4681	<	* @param s the stream
4682	<	*/
4683	<	private void readObject(java.io.ObjectInputStream s)
4684	<	throws IOException, ClassNotFoundException  {
4685	<	s.defaultReadObject();
4678	>	/*
4679	>	* Task classes. Coded in a regular but ugly format/style to
4680	>	* simplify checks that each variant differs in the right way from
4681	>	* others. The null screenings exist because compilers cannot tell
4682	>	* that we've already null-checked task arguments, so we force
4683	>	* simplest hoisted bypass to help avoid convoluted traps.
4684	>	*/
4685	>	@SuppressWarnings("serial")
4686	>	static final class ForEachKeyTask<K,V>
4687	>	extends BulkTask<K,V,Void> {
4688	>	final Consumer<? super K> action;
4689	>	ForEachKeyTask
4690	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4691	>	Consumer<? super K> action) {
4692	>	super(p, b, i, f, t);
4693	>	this.action = action;
4694	>	}
4695	>	public final void compute() {
4696	>	final Consumer<? super K> action;
4697	>	if ((action = this.action) != null) {
4698	>	for (int i = baseIndex, f, h; batch > 0 &&
4699	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4700	>	addToPendingCount(1);
4701	>	new ForEachKeyTask<K,V>
4702	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4703	>	action).fork();
4704	>	}
4705	>	for (Node<K,V> p; (p = advance()) != null;)
4706	>	action.accept(p.key);
4707	>	propagateCompletion();
4708	>	}
4709	>	}
4710	>	}
4711
4712	<	// Initialize each segment to be minimally sized, and let grow.
4713	<	for (int i = 0; i < segments.length; ++i) {
4714	<	segments[i].setTable(new HashEntry[1]);
4712	>	@SuppressWarnings("serial")
4713	>	static final class ForEachValueTask<K,V>
4714	>	extends BulkTask<K,V,Void> {
4715	>	final Consumer<? super V> action;
4716	>	ForEachValueTask
4717	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4718	>	Consumer<? super V> action) {
4719	>	super(p, b, i, f, t);
4720	>	this.action = action;
4721	>	}
4722	>	public final void compute() {
4723	>	final Consumer<? super V> action;
4724	>	if ((action = this.action) != null) {
4725	>	for (int i = baseIndex, f, h; batch > 0 &&
4726	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4727	>	addToPendingCount(1);
4728	>	new ForEachValueTask<K,V>
4729	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4730	>	action).fork();
4731	>	}
4732	>	for (Node<K,V> p; (p = advance()) != null;)
4733	>	action.accept(p.val);
4734	>	propagateCompletion();
4735	>	}
4736		}
4737	+	}
4738
4739	<	// Read the keys and values, and put the mappings in the table
4740	<	for (;;) {
4741	<	K key = (K) s.readObject();
4742	<	V value = (V) s.readObject();
4743	<	if (key == null)
4744	<	break;
4745	<	put(key, value);
4739	>	@SuppressWarnings("serial")
4740	>	static final class ForEachEntryTask<K,V>
4741	>	extends BulkTask<K,V,Void> {
4742	>	final Consumer<? super Entry<K,V>> action;
4743	>	ForEachEntryTask
4744	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4745	>	Consumer<? super Entry<K,V>> action) {
4746	>	super(p, b, i, f, t);
4747	>	this.action = action;
4748	>	}
4749	>	public final void compute() {
4750	>	final Consumer<? super Entry<K,V>> action;
4751	>	if ((action = this.action) != null) {
4752	>	for (int i = baseIndex, f, h; batch > 0 &&
4753	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4754	>	addToPendingCount(1);
4755	>	new ForEachEntryTask<K,V>
4756	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4757	>	action).fork();
4758	>	}
4759	>	for (Node<K,V> p; (p = advance()) != null; )
4760	>	action.accept(p);
4761	>	propagateCompletion();
4762	>	}
4763	>	}
4764	>	}
4765	>
4766	>	@SuppressWarnings("serial")
4767	>	static final class ForEachMappingTask<K,V>
4768	>	extends BulkTask<K,V,Void> {
4769	>	final BiConsumer<? super K, ? super V> action;
4770	>	ForEachMappingTask
4771	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4772	>	BiConsumer<? super K,? super V> action) {
4773	>	super(p, b, i, f, t);
4774	>	this.action = action;
4775	>	}
4776	>	public final void compute() {
4777	>	final BiConsumer<? super K, ? super V> action;
4778	>	if ((action = this.action) != null) {
4779	>	for (int i = baseIndex, f, h; batch > 0 &&
4780	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4781	>	addToPendingCount(1);
4782	>	new ForEachMappingTask<K,V>
4783	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4784	>	action).fork();
4785	>	}
4786	>	for (Node<K,V> p; (p = advance()) != null; )
4787	>	action.accept(p.key, p.val);
4788	>	propagateCompletion();
4789	>	}
4790	>	}
4791	>	}
4792	>
4793	>	@SuppressWarnings("serial")
4794	>	static final class ForEachTransformedKeyTask<K,V,U>
4795	>	extends BulkTask<K,V,Void> {
4796	>	final Function<? super K, ? extends U> transformer;
4797	>	final Consumer<? super U> action;
4798	>	ForEachTransformedKeyTask
4799	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4800	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4801	>	super(p, b, i, f, t);
4802	>	this.transformer = transformer; this.action = action;
4803	>	}
4804	>	public final void compute() {
4805	>	final Function<? super K, ? extends U> transformer;
4806	>	final Consumer<? super U> action;
4807	>	if ((transformer = this.transformer) != null &&
4808	>	(action = this.action) != null) {
4809	>	for (int i = baseIndex, f, h; batch > 0 &&
4810	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4811	>	addToPendingCount(1);
4812	>	new ForEachTransformedKeyTask<K,V,U>
4813	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4814	>	transformer, action).fork();
4815	>	}
4816	>	for (Node<K,V> p; (p = advance()) != null; ) {
4817	>	U u;
4818	>	if ((u = transformer.apply(p.key)) != null)
4819	>	action.accept(u);
4820	>	}
4821	>	propagateCompletion();
4822	>	}
4823	>	}
4824	>	}
4825	>
4826	>	@SuppressWarnings("serial")
4827	>	static final class ForEachTransformedValueTask<K,V,U>
4828	>	extends BulkTask<K,V,Void> {
4829	>	final Function<? super V, ? extends U> transformer;
4830	>	final Consumer<? super U> action;
4831	>	ForEachTransformedValueTask
4832	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4833	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4834	>	super(p, b, i, f, t);
4835	>	this.transformer = transformer; this.action = action;
4836	>	}
4837	>	public final void compute() {
4838	>	final Function<? super V, ? extends U> transformer;
4839	>	final Consumer<? super U> action;
4840	>	if ((transformer = this.transformer) != null &&
4841	>	(action = this.action) != null) {
4842	>	for (int i = baseIndex, f, h; batch > 0 &&
4843	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4844	>	addToPendingCount(1);
4845	>	new ForEachTransformedValueTask<K,V,U>
4846	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4847	>	transformer, action).fork();
4848	>	}
4849	>	for (Node<K,V> p; (p = advance()) != null; ) {
4850	>	U u;
4851	>	if ((u = transformer.apply(p.val)) != null)
4852	>	action.accept(u);
4853	>	}
4854	>	propagateCompletion();
4855	>	}
4856	>	}
4857	>	}
4858	>
4859	>	@SuppressWarnings("serial")
4860	>	static final class ForEachTransformedEntryTask<K,V,U>
4861	>	extends BulkTask<K,V,Void> {
4862	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4863	>	final Consumer<? super U> action;
4864	>	ForEachTransformedEntryTask
4865	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4866	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4867	>	super(p, b, i, f, t);
4868	>	this.transformer = transformer; this.action = action;
4869	>	}
4870	>	public final void compute() {
4871	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4872	>	final Consumer<? super U> action;
4873	>	if ((transformer = this.transformer) != null &&
4874	>	(action = this.action) != null) {
4875	>	for (int i = baseIndex, f, h; batch > 0 &&
4876	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4877	>	addToPendingCount(1);
4878	>	new ForEachTransformedEntryTask<K,V,U>
4879	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4880	>	transformer, action).fork();
4881	>	}
4882	>	for (Node<K,V> p; (p = advance()) != null; ) {
4883	>	U u;
4884	>	if ((u = transformer.apply(p)) != null)
4885	>	action.accept(u);
4886	>	}
4887	>	propagateCompletion();
4888	>	}
4889	>	}
4890	>	}
4891	>
4892	>	@SuppressWarnings("serial")
4893	>	static final class ForEachTransformedMappingTask<K,V,U>
4894	>	extends BulkTask<K,V,Void> {
4895	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4896	>	final Consumer<? super U> action;
4897	>	ForEachTransformedMappingTask
4898	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4899	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4900	>	Consumer<? super U> action) {
4901	>	super(p, b, i, f, t);
4902	>	this.transformer = transformer; this.action = action;
4903	>	}
4904	>	public final void compute() {
4905	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4906	>	final Consumer<? super U> action;
4907	>	if ((transformer = this.transformer) != null &&
4908	>	(action = this.action) != null) {
4909	>	for (int i = baseIndex, f, h; batch > 0 &&
4910	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4911	>	addToPendingCount(1);
4912	>	new ForEachTransformedMappingTask<K,V,U>
4913	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4914	>	transformer, action).fork();
4915	>	}
4916	>	for (Node<K,V> p; (p = advance()) != null; ) {
4917	>	U u;
4918	>	if ((u = transformer.apply(p.key, p.val)) != null)
4919	>	action.accept(u);
4920	>	}
4921	>	propagateCompletion();
4922	>	}
4923	>	}
4924	>	}
4925	>
4926	>	@SuppressWarnings("serial")
4927	>	static final class SearchKeysTask<K,V,U>
4928	>	extends BulkTask<K,V,U> {
4929	>	final Function<? super K, ? extends U> searchFunction;
4930	>	final AtomicReference<U> result;
4931	>	SearchKeysTask
4932	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4933	>	Function<? super K, ? extends U> searchFunction,
4934	>	AtomicReference<U> result) {
4935	>	super(p, b, i, f, t);
4936	>	this.searchFunction = searchFunction; this.result = result;
4937	>	}
4938	>	public final U getRawResult() { return result.get(); }
4939	>	public final void compute() {
4940	>	final Function<? super K, ? extends U> searchFunction;
4941	>	final AtomicReference<U> result;
4942	>	if ((searchFunction = this.searchFunction) != null &&
4943	>	(result = this.result) != null) {
4944	>	for (int i = baseIndex, f, h; batch > 0 &&
4945	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4946	>	if (result.get() != null)
4947	>	return;
4948	>	addToPendingCount(1);
4949	>	new SearchKeysTask<K,V,U>
4950	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4951	>	searchFunction, result).fork();
4952	>	}
4953	>	while (result.get() == null) {
4954	>	U u;
4955	>	Node<K,V> p;
4956	>	if ((p = advance()) == null) {
4957	>	propagateCompletion();
4958	>	break;
4959	>	}
4960	>	if ((u = searchFunction.apply(p.key)) != null) {
4961	>	if (result.compareAndSet(null, u))
4962	>	quietlyCompleteRoot();
4963	>	break;
4964	>	}
4965	>	}
4966	>	}
4967	>	}
4968	>	}
4969	>
4970	>	@SuppressWarnings("serial")
4971	>	static final class SearchValuesTask<K,V,U>
4972	>	extends BulkTask<K,V,U> {
4973	>	final Function<? super V, ? extends U> searchFunction;
4974	>	final AtomicReference<U> result;
4975	>	SearchValuesTask
4976	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4977	>	Function<? super V, ? extends U> searchFunction,
4978	>	AtomicReference<U> result) {
4979	>	super(p, b, i, f, t);
4980	>	this.searchFunction = searchFunction; this.result = result;
4981	>	}
4982	>	public final U getRawResult() { return result.get(); }
4983	>	public final void compute() {
4984	>	final Function<? super V, ? extends U> searchFunction;
4985	>	final AtomicReference<U> result;
4986	>	if ((searchFunction = this.searchFunction) != null &&
4987	>	(result = this.result) != null) {
4988	>	for (int i = baseIndex, f, h; batch > 0 &&
4989	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4990	>	if (result.get() != null)
4991	>	return;
4992	>	addToPendingCount(1);
4993	>	new SearchValuesTask<K,V,U>
4994	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4995	>	searchFunction, result).fork();
4996	>	}
4997	>	while (result.get() == null) {
4998	>	U u;
4999	>	Node<K,V> p;
5000	>	if ((p = advance()) == null) {
5001	>	propagateCompletion();
5002	>	break;
5003	>	}
5004	>	if ((u = searchFunction.apply(p.val)) != null) {
5005	>	if (result.compareAndSet(null, u))
5006	>	quietlyCompleteRoot();
5007	>	break;
5008	>	}
5009	>	}
5010	>	}
5011	>	}
5012	>	}
5013	>
5014	>	@SuppressWarnings("serial")
5015	>	static final class SearchEntriesTask<K,V,U>
5016	>	extends BulkTask<K,V,U> {
5017	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5018	>	final AtomicReference<U> result;
5019	>	SearchEntriesTask
5020	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5021	>	Function<Entry<K,V>, ? extends U> searchFunction,
5022	>	AtomicReference<U> result) {
5023	>	super(p, b, i, f, t);
5024	>	this.searchFunction = searchFunction; this.result = result;
5025	>	}
5026	>	public final U getRawResult() { return result.get(); }
5027	>	public final void compute() {
5028	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5029	>	final AtomicReference<U> result;
5030	>	if ((searchFunction = this.searchFunction) != null &&
5031	>	(result = this.result) != null) {
5032	>	for (int i = baseIndex, f, h; batch > 0 &&
5033	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5034	>	if (result.get() != null)
5035	>	return;
5036	>	addToPendingCount(1);
5037	>	new SearchEntriesTask<K,V,U>
5038	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5039	>	searchFunction, result).fork();
5040	>	}
5041	>	while (result.get() == null) {
5042	>	U u;
5043	>	Node<K,V> p;
5044	>	if ((p = advance()) == null) {
5045	>	propagateCompletion();
5046	>	break;
5047	>	}
5048	>	if ((u = searchFunction.apply(p)) != null) {
5049	>	if (result.compareAndSet(null, u))
5050	>	quietlyCompleteRoot();
5051	>	return;
5052	>	}
5053	>	}
5054	>	}
5055	>	}
5056	>	}
5057	>
5058	>	@SuppressWarnings("serial")
5059	>	static final class SearchMappingsTask<K,V,U>
5060	>	extends BulkTask<K,V,U> {
5061	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5062	>	final AtomicReference<U> result;
5063	>	SearchMappingsTask
5064	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5065	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5066	>	AtomicReference<U> result) {
5067	>	super(p, b, i, f, t);
5068	>	this.searchFunction = searchFunction; this.result = result;
5069	>	}
5070	>	public final U getRawResult() { return result.get(); }
5071	>	public final void compute() {
5072	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5073	>	final AtomicReference<U> result;
5074	>	if ((searchFunction = this.searchFunction) != null &&
5075	>	(result = this.result) != null) {
5076	>	for (int i = baseIndex, f, h; batch > 0 &&
5077	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5078	>	if (result.get() != null)
5079	>	return;
5080	>	addToPendingCount(1);
5081	>	new SearchMappingsTask<K,V,U>
5082	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5083	>	searchFunction, result).fork();
5084	>	}
5085	>	while (result.get() == null) {
5086	>	U u;
5087	>	Node<K,V> p;
5088	>	if ((p = advance()) == null) {
5089	>	propagateCompletion();
5090	>	break;
5091	>	}
5092	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5093	>	if (result.compareAndSet(null, u))
5094	>	quietlyCompleteRoot();
5095	>	break;
5096	>	}
5097	>	}
5098	>	}
5099	>	}
5100	>	}
5101	>
5102	>	@SuppressWarnings("serial")
5103	>	static final class ReduceKeysTask<K,V>
5104	>	extends BulkTask<K,V,K> {
5105	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5106	>	K result;
5107	>	ReduceKeysTask<K,V> rights, nextRight;
5108	>	ReduceKeysTask
5109	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5110	>	ReduceKeysTask<K,V> nextRight,
5111	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5112	>	super(p, b, i, f, t); this.nextRight = nextRight;
5113	>	this.reducer = reducer;
5114	>	}
5115	>	public final K getRawResult() { return result; }
5116	>	public final void compute() {
5117	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5118	>	if ((reducer = this.reducer) != null) {
5119	>	for (int i = baseIndex, f, h; batch > 0 &&
5120	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5121	>	addToPendingCount(1);
5122	>	(rights = new ReduceKeysTask<K,V>
5123	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5124	>	rights, reducer)).fork();
5125	>	}
5126	>	K r = null;
5127	>	for (Node<K,V> p; (p = advance()) != null; ) {
5128	>	K u = p.key;
5129	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5130	>	}
5131	>	result = r;
5132	>	CountedCompleter<?> c;
5133	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5134	>	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5135	>	t = (ReduceKeysTask<K,V>)c,
5136	>	s = t.rights;
5137	>	while (s != null) {
5138	>	K tr, sr;
5139	>	if ((sr = s.result) != null)
5140	>	t.result = (((tr = t.result) == null) ? sr :
5141	>	reducer.apply(tr, sr));
5142	>	s = t.rights = s.nextRight;
5143	>	}
5144	>	}
5145	>	}
5146	>	}
5147	>	}
5148	>
5149	>	@SuppressWarnings("serial")
5150	>	static final class ReduceValuesTask<K,V>
5151	>	extends BulkTask<K,V,V> {
5152	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5153	>	V result;
5154	>	ReduceValuesTask<K,V> rights, nextRight;
5155	>	ReduceValuesTask
5156	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5157	>	ReduceValuesTask<K,V> nextRight,
5158	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5159	>	super(p, b, i, f, t); this.nextRight = nextRight;
5160	>	this.reducer = reducer;
5161	>	}
5162	>	public final V getRawResult() { return result; }
5163	>	public final void compute() {
5164	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5165	>	if ((reducer = this.reducer) != null) {
5166	>	for (int i = baseIndex, f, h; batch > 0 &&
5167	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5168	>	addToPendingCount(1);
5169	>	(rights = new ReduceValuesTask<K,V>
5170	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5171	>	rights, reducer)).fork();
5172	>	}
5173	>	V r = null;
5174	>	for (Node<K,V> p; (p = advance()) != null; ) {
5175	>	V v = p.val;
5176	>	r = (r == null) ? v : reducer.apply(r, v);
5177	>	}
5178	>	result = r;
5179	>	CountedCompleter<?> c;
5180	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5181	>	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5182	>	t = (ReduceValuesTask<K,V>)c,
5183	>	s = t.rights;
5184	>	while (s != null) {
5185	>	V tr, sr;
5186	>	if ((sr = s.result) != null)
5187	>	t.result = (((tr = t.result) == null) ? sr :
5188	>	reducer.apply(tr, sr));
5189	>	s = t.rights = s.nextRight;
5190	>	}
5191	>	}
5192	>	}
5193	>	}
5194	>	}
5195	>
5196	>	@SuppressWarnings("serial")
5197	>	static final class ReduceEntriesTask<K,V>
5198	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5199	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5200	>	Map.Entry<K,V> result;
5201	>	ReduceEntriesTask<K,V> rights, nextRight;
5202	>	ReduceEntriesTask
5203	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5204	>	ReduceEntriesTask<K,V> nextRight,
5205	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5206	>	super(p, b, i, f, t); this.nextRight = nextRight;
5207	>	this.reducer = reducer;
5208	>	}
5209	>	public final Map.Entry<K,V> getRawResult() { return result; }
5210	>	public final void compute() {
5211	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5212	>	if ((reducer = this.reducer) != null) {
5213	>	for (int i = baseIndex, f, h; batch > 0 &&
5214	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5215	>	addToPendingCount(1);
5216	>	(rights = new ReduceEntriesTask<K,V>
5217	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5218	>	rights, reducer)).fork();
5219	>	}
5220	>	Map.Entry<K,V> r = null;
5221	>	for (Node<K,V> p; (p = advance()) != null; )
5222	>	r = (r == null) ? p : reducer.apply(r, p);
5223	>	result = r;
5224	>	CountedCompleter<?> c;
5225	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5226	>	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5227	>	t = (ReduceEntriesTask<K,V>)c,
5228	>	s = t.rights;
5229	>	while (s != null) {
5230	>	Map.Entry<K,V> tr, sr;
5231	>	if ((sr = s.result) != null)
5232	>	t.result = (((tr = t.result) == null) ? sr :
5233	>	reducer.apply(tr, sr));
5234	>	s = t.rights = s.nextRight;
5235	>	}
5236	>	}
5237	>	}
5238	>	}
5239	>	}
5240	>
5241	>	@SuppressWarnings("serial")
5242	>	static final class MapReduceKeysTask<K,V,U>
5243	>	extends BulkTask<K,V,U> {
5244	>	final Function<? super K, ? extends U> transformer;
5245	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5246	>	U result;
5247	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5248	>	MapReduceKeysTask
5249	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5250	>	MapReduceKeysTask<K,V,U> nextRight,
5251	>	Function<? super K, ? extends U> transformer,
5252	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5253	>	super(p, b, i, f, t); this.nextRight = nextRight;
5254	>	this.transformer = transformer;
5255	>	this.reducer = reducer;
5256	>	}
5257	>	public final U getRawResult() { return result; }
5258	>	public final void compute() {
5259	>	final Function<? super K, ? extends U> transformer;
5260	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5261	>	if ((transformer = this.transformer) != null &&
5262	>	(reducer = this.reducer) != null) {
5263	>	for (int i = baseIndex, f, h; batch > 0 &&
5264	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5265	>	addToPendingCount(1);
5266	>	(rights = new MapReduceKeysTask<K,V,U>
5267	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5268	>	rights, transformer, reducer)).fork();
5269	>	}
5270	>	U r = null;
5271	>	for (Node<K,V> p; (p = advance()) != null; ) {
5272	>	U u;
5273	>	if ((u = transformer.apply(p.key)) != null)
5274	>	r = (r == null) ? u : reducer.apply(r, u);
5275	>	}
5276	>	result = r;
5277	>	CountedCompleter<?> c;
5278	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5279	>	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5280	>	t = (MapReduceKeysTask<K,V,U>)c,
5281	>	s = t.rights;
5282	>	while (s != null) {
5283	>	U tr, sr;
5284	>	if ((sr = s.result) != null)
5285	>	t.result = (((tr = t.result) == null) ? sr :
5286	>	reducer.apply(tr, sr));
5287	>	s = t.rights = s.nextRight;
5288	>	}
5289	>	}
5290	>	}
5291	>	}
5292	>	}
5293	>
5294	>	@SuppressWarnings("serial")
5295	>	static final class MapReduceValuesTask<K,V,U>
5296	>	extends BulkTask<K,V,U> {
5297	>	final Function<? super V, ? extends U> transformer;
5298	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5299	>	U result;
5300	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5301	>	MapReduceValuesTask
5302	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5303	>	MapReduceValuesTask<K,V,U> nextRight,
5304	>	Function<? super V, ? extends U> transformer,
5305	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5306	>	super(p, b, i, f, t); this.nextRight = nextRight;
5307	>	this.transformer = transformer;
5308	>	this.reducer = reducer;
5309	>	}
5310	>	public final U getRawResult() { return result; }
5311	>	public final void compute() {
5312	>	final Function<? super V, ? extends U> transformer;
5313	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5314	>	if ((transformer = this.transformer) != null &&
5315	>	(reducer = this.reducer) != null) {
5316	>	for (int i = baseIndex, f, h; batch > 0 &&
5317	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5318	>	addToPendingCount(1);
5319	>	(rights = new MapReduceValuesTask<K,V,U>
5320	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5321	>	rights, transformer, reducer)).fork();
5322	>	}
5323	>	U r = null;
5324	>	for (Node<K,V> p; (p = advance()) != null; ) {
5325	>	U u;
5326	>	if ((u = transformer.apply(p.val)) != null)
5327	>	r = (r == null) ? u : reducer.apply(r, u);
5328	>	}
5329	>	result = r;
5330	>	CountedCompleter<?> c;
5331	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5332	>	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5333	>	t = (MapReduceValuesTask<K,V,U>)c,
5334	>	s = t.rights;
5335	>	while (s != null) {
5336	>	U tr, sr;
5337	>	if ((sr = s.result) != null)
5338	>	t.result = (((tr = t.result) == null) ? sr :
5339	>	reducer.apply(tr, sr));
5340	>	s = t.rights = s.nextRight;
5341	>	}
5342	>	}
5343	>	}
5344	>	}
5345	>	}
5346	>
5347	>	@SuppressWarnings("serial")
5348	>	static final class MapReduceEntriesTask<K,V,U>
5349	>	extends BulkTask<K,V,U> {
5350	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5351	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5352	>	U result;
5353	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5354	>	MapReduceEntriesTask
5355	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5356	>	MapReduceEntriesTask<K,V,U> nextRight,
5357	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5358	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5359	>	super(p, b, i, f, t); this.nextRight = nextRight;
5360	>	this.transformer = transformer;
5361	>	this.reducer = reducer;
5362	>	}
5363	>	public final U getRawResult() { return result; }
5364	>	public final void compute() {
5365	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5366	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5367	>	if ((transformer = this.transformer) != null &&
5368	>	(reducer = this.reducer) != null) {
5369	>	for (int i = baseIndex, f, h; batch > 0 &&
5370	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5371	>	addToPendingCount(1);
5372	>	(rights = new MapReduceEntriesTask<K,V,U>
5373	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5374	>	rights, transformer, reducer)).fork();
5375	>	}
5376	>	U r = null;
5377	>	for (Node<K,V> p; (p = advance()) != null; ) {
5378	>	U u;
5379	>	if ((u = transformer.apply(p)) != null)
5380	>	r = (r == null) ? u : reducer.apply(r, u);
5381	>	}
5382	>	result = r;
5383	>	CountedCompleter<?> c;
5384	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5385	>	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5386	>	t = (MapReduceEntriesTask<K,V,U>)c,
5387	>	s = t.rights;
5388	>	while (s != null) {
5389	>	U tr, sr;
5390	>	if ((sr = s.result) != null)
5391	>	t.result = (((tr = t.result) == null) ? sr :
5392	>	reducer.apply(tr, sr));
5393	>	s = t.rights = s.nextRight;
5394	>	}
5395	>	}
5396	>	}
5397	>	}
5398	>	}
5399	>
5400	>	@SuppressWarnings("serial")
5401	>	static final class MapReduceMappingsTask<K,V,U>
5402	>	extends BulkTask<K,V,U> {
5403	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5404	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5405	>	U result;
5406	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5407	>	MapReduceMappingsTask
5408	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5409	>	MapReduceMappingsTask<K,V,U> nextRight,
5410	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5411	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5412	>	super(p, b, i, f, t); this.nextRight = nextRight;
5413	>	this.transformer = transformer;
5414	>	this.reducer = reducer;
5415	>	}
5416	>	public final U getRawResult() { return result; }
5417	>	public final void compute() {
5418	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5419	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5420	>	if ((transformer = this.transformer) != null &&
5421	>	(reducer = this.reducer) != null) {
5422	>	for (int i = baseIndex, f, h; batch > 0 &&
5423	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5424	>	addToPendingCount(1);
5425	>	(rights = new MapReduceMappingsTask<K,V,U>
5426	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5427	>	rights, transformer, reducer)).fork();
5428	>	}
5429	>	U r = null;
5430	>	for (Node<K,V> p; (p = advance()) != null; ) {
5431	>	U u;
5432	>	if ((u = transformer.apply(p.key, p.val)) != null)
5433	>	r = (r == null) ? u : reducer.apply(r, u);
5434	>	}
5435	>	result = r;
5436	>	CountedCompleter<?> c;
5437	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5438	>	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5439	>	t = (MapReduceMappingsTask<K,V,U>)c,
5440	>	s = t.rights;
5441	>	while (s != null) {
5442	>	U tr, sr;
5443	>	if ((sr = s.result) != null)
5444	>	t.result = (((tr = t.result) == null) ? sr :
5445	>	reducer.apply(tr, sr));
5446	>	s = t.rights = s.nextRight;
5447	>	}
5448	>	}
5449	>	}
5450	>	}
5451	>	}
5452	>
5453	>	@SuppressWarnings("serial")
5454	>	static final class MapReduceKeysToDoubleTask<K,V>
5455	>	extends BulkTask<K,V,Double> {
5456	>	final ToDoubleFunction<? super K> transformer;
5457	>	final DoubleBinaryOperator reducer;
5458	>	final double basis;
5459	>	double result;
5460	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5461	>	MapReduceKeysToDoubleTask
5462	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5463	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5464	>	ToDoubleFunction<? super K> transformer,
5465	>	double basis,
5466	>	DoubleBinaryOperator reducer) {
5467	>	super(p, b, i, f, t); this.nextRight = nextRight;
5468	>	this.transformer = transformer;
5469	>	this.basis = basis; this.reducer = reducer;
5470	>	}
5471	>	public final Double getRawResult() { return result; }
5472	>	public final void compute() {
5473	>	final ToDoubleFunction<? super K> transformer;
5474	>	final DoubleBinaryOperator reducer;
5475	>	if ((transformer = this.transformer) != null &&
5476	>	(reducer = this.reducer) != null) {
5477	>	double r = this.basis;
5478	>	for (int i = baseIndex, f, h; batch > 0 &&
5479	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5480	>	addToPendingCount(1);
5481	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5482	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5483	>	rights, transformer, r, reducer)).fork();
5484	>	}
5485	>	for (Node<K,V> p; (p = advance()) != null; )
5486	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5487	>	result = r;
5488	>	CountedCompleter<?> c;
5489	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5490	>	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5491	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5492	>	s = t.rights;
5493	>	while (s != null) {
5494	>	t.result = reducer.applyAsDouble(t.result, s.result);
5495	>	s = t.rights = s.nextRight;
5496	>	}
5497	>	}
5498	>	}
5499	>	}
5500	>	}
5501	>
5502	>	@SuppressWarnings("serial")
5503	>	static final class MapReduceValuesToDoubleTask<K,V>
5504	>	extends BulkTask<K,V,Double> {
5505	>	final ToDoubleFunction<? super V> transformer;
5506	>	final DoubleBinaryOperator reducer;
5507	>	final double basis;
5508	>	double result;
5509	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5510	>	MapReduceValuesToDoubleTask
5511	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5512	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5513	>	ToDoubleFunction<? super V> transformer,
5514	>	double basis,
5515	>	DoubleBinaryOperator reducer) {
5516	>	super(p, b, i, f, t); this.nextRight = nextRight;
5517	>	this.transformer = transformer;
5518	>	this.basis = basis; this.reducer = reducer;
5519	>	}
5520	>	public final Double getRawResult() { return result; }
5521	>	public final void compute() {
5522	>	final ToDoubleFunction<? super V> transformer;
5523	>	final DoubleBinaryOperator reducer;
5524	>	if ((transformer = this.transformer) != null &&
5525	>	(reducer = this.reducer) != null) {
5526	>	double r = this.basis;
5527	>	for (int i = baseIndex, f, h; batch > 0 &&
5528	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5529	>	addToPendingCount(1);
5530	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5531	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5532	>	rights, transformer, r, reducer)).fork();
5533	>	}
5534	>	for (Node<K,V> p; (p = advance()) != null; )
5535	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5536	>	result = r;
5537	>	CountedCompleter<?> c;
5538	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5539	>	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5540	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5541	>	s = t.rights;
5542	>	while (s != null) {
5543	>	t.result = reducer.applyAsDouble(t.result, s.result);
5544	>	s = t.rights = s.nextRight;
5545	>	}
5546	>	}
5547	>	}
5548	>	}
5549	>	}
5550	>
5551	>	@SuppressWarnings("serial")
5552	>	static final class MapReduceEntriesToDoubleTask<K,V>
5553	>	extends BulkTask<K,V,Double> {
5554	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5555	>	final DoubleBinaryOperator reducer;
5556	>	final double basis;
5557	>	double result;
5558	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5559	>	MapReduceEntriesToDoubleTask
5560	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5561	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5562	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5563	>	double basis,
5564	>	DoubleBinaryOperator reducer) {
5565	>	super(p, b, i, f, t); this.nextRight = nextRight;
5566	>	this.transformer = transformer;
5567	>	this.basis = basis; this.reducer = reducer;
5568	>	}
5569	>	public final Double getRawResult() { return result; }
5570	>	public final void compute() {
5571	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5572	>	final DoubleBinaryOperator reducer;
5573	>	if ((transformer = this.transformer) != null &&
5574	>	(reducer = this.reducer) != null) {
5575	>	double r = this.basis;
5576	>	for (int i = baseIndex, f, h; batch > 0 &&
5577	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5578	>	addToPendingCount(1);
5579	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5580	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5581	>	rights, transformer, r, reducer)).fork();
5582	>	}
5583	>	for (Node<K,V> p; (p = advance()) != null; )
5584	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5585	>	result = r;
5586	>	CountedCompleter<?> c;
5587	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5588	>	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5589	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5590	>	s = t.rights;
5591	>	while (s != null) {
5592	>	t.result = reducer.applyAsDouble(t.result, s.result);
5593	>	s = t.rights = s.nextRight;
5594	>	}
5595	>	}
5596	>	}
5597	>	}
5598	>	}
5599	>
5600	>	@SuppressWarnings("serial")
5601	>	static final class MapReduceMappingsToDoubleTask<K,V>
5602	>	extends BulkTask<K,V,Double> {
5603	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5604	>	final DoubleBinaryOperator reducer;
5605	>	final double basis;
5606	>	double result;
5607	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5608	>	MapReduceMappingsToDoubleTask
5609	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5610	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5611	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5612	>	double basis,
5613	>	DoubleBinaryOperator reducer) {
5614	>	super(p, b, i, f, t); this.nextRight = nextRight;
5615	>	this.transformer = transformer;
5616	>	this.basis = basis; this.reducer = reducer;
5617	>	}
5618	>	public final Double getRawResult() { return result; }
5619	>	public final void compute() {
5620	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5621	>	final DoubleBinaryOperator reducer;
5622	>	if ((transformer = this.transformer) != null &&
5623	>	(reducer = this.reducer) != null) {
5624	>	double r = this.basis;
5625	>	for (int i = baseIndex, f, h; batch > 0 &&
5626	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5627	>	addToPendingCount(1);
5628	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5629	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5630	>	rights, transformer, r, reducer)).fork();
5631	>	}
5632	>	for (Node<K,V> p; (p = advance()) != null; )
5633	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5634	>	result = r;
5635	>	CountedCompleter<?> c;
5636	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5637	>	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5638	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5639	>	s = t.rights;
5640	>	while (s != null) {
5641	>	t.result = reducer.applyAsDouble(t.result, s.result);
5642	>	s = t.rights = s.nextRight;
5643	>	}
5644	>	}
5645	>	}
5646	>	}
5647	>	}
5648	>
5649	>	@SuppressWarnings("serial")
5650	>	static final class MapReduceKeysToLongTask<K,V>
5651	>	extends BulkTask<K,V,Long> {
5652	>	final ToLongFunction<? super K> transformer;
5653	>	final LongBinaryOperator reducer;
5654	>	final long basis;
5655	>	long result;
5656	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5657	>	MapReduceKeysToLongTask
5658	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5659	>	MapReduceKeysToLongTask<K,V> nextRight,
5660	>	ToLongFunction<? super K> transformer,
5661	>	long basis,
5662	>	LongBinaryOperator reducer) {
5663	>	super(p, b, i, f, t); this.nextRight = nextRight;
5664	>	this.transformer = transformer;
5665	>	this.basis = basis; this.reducer = reducer;
5666	>	}
5667	>	public final Long getRawResult() { return result; }
5668	>	public final void compute() {
5669	>	final ToLongFunction<? super K> transformer;
5670	>	final LongBinaryOperator reducer;
5671	>	if ((transformer = this.transformer) != null &&
5672	>	(reducer = this.reducer) != null) {
5673	>	long r = this.basis;
5674	>	for (int i = baseIndex, f, h; batch > 0 &&
5675	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5676	>	addToPendingCount(1);
5677	>	(rights = new MapReduceKeysToLongTask<K,V>
5678	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5679	>	rights, transformer, r, reducer)).fork();
5680	>	}
5681	>	for (Node<K,V> p; (p = advance()) != null; )
5682	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5683	>	result = r;
5684	>	CountedCompleter<?> c;
5685	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5686	>	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5687	>	t = (MapReduceKeysToLongTask<K,V>)c,
5688	>	s = t.rights;
5689	>	while (s != null) {
5690	>	t.result = reducer.applyAsLong(t.result, s.result);
5691	>	s = t.rights = s.nextRight;
5692	>	}
5693	>	}
5694	>	}
5695	>	}
5696	>	}
5697	>
5698	>	@SuppressWarnings("serial")
5699	>	static final class MapReduceValuesToLongTask<K,V>
5700	>	extends BulkTask<K,V,Long> {
5701	>	final ToLongFunction<? super V> transformer;
5702	>	final LongBinaryOperator reducer;
5703	>	final long basis;
5704	>	long result;
5705	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5706	>	MapReduceValuesToLongTask
5707	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5708	>	MapReduceValuesToLongTask<K,V> nextRight,
5709	>	ToLongFunction<? super V> transformer,
5710	>	long basis,
5711	>	LongBinaryOperator reducer) {
5712	>	super(p, b, i, f, t); this.nextRight = nextRight;
5713	>	this.transformer = transformer;
5714	>	this.basis = basis; this.reducer = reducer;
5715	>	}
5716	>	public final Long getRawResult() { return result; }
5717	>	public final void compute() {
5718	>	final ToLongFunction<? super V> transformer;
5719	>	final LongBinaryOperator reducer;
5720	>	if ((transformer = this.transformer) != null &&
5721	>	(reducer = this.reducer) != null) {
5722	>	long r = this.basis;
5723	>	for (int i = baseIndex, f, h; batch > 0 &&
5724	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5725	>	addToPendingCount(1);
5726	>	(rights = new MapReduceValuesToLongTask<K,V>
5727	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5728	>	rights, transformer, r, reducer)).fork();
5729	>	}
5730	>	for (Node<K,V> p; (p = advance()) != null; )
5731	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5732	>	result = r;
5733	>	CountedCompleter<?> c;
5734	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5735	>	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5736	>	t = (MapReduceValuesToLongTask<K,V>)c,
5737	>	s = t.rights;
5738	>	while (s != null) {
5739	>	t.result = reducer.applyAsLong(t.result, s.result);
5740	>	s = t.rights = s.nextRight;
5741	>	}
5742	>	}
5743	>	}
5744	>	}
5745	>	}
5746	>
5747	>	@SuppressWarnings("serial")
5748	>	static final class MapReduceEntriesToLongTask<K,V>
5749	>	extends BulkTask<K,V,Long> {
5750	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5751	>	final LongBinaryOperator reducer;
5752	>	final long basis;
5753	>	long result;
5754	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5755	>	MapReduceEntriesToLongTask
5756	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5757	>	MapReduceEntriesToLongTask<K,V> nextRight,
5758	>	ToLongFunction<Map.Entry<K,V>> transformer,
5759	>	long basis,
5760	>	LongBinaryOperator reducer) {
5761	>	super(p, b, i, f, t); this.nextRight = nextRight;
5762	>	this.transformer = transformer;
5763	>	this.basis = basis; this.reducer = reducer;
5764	>	}
5765	>	public final Long getRawResult() { return result; }
5766	>	public final void compute() {
5767	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5768	>	final LongBinaryOperator reducer;
5769	>	if ((transformer = this.transformer) != null &&
5770	>	(reducer = this.reducer) != null) {
5771	>	long r = this.basis;
5772	>	for (int i = baseIndex, f, h; batch > 0 &&
5773	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5774	>	addToPendingCount(1);
5775	>	(rights = new MapReduceEntriesToLongTask<K,V>
5776	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5777	>	rights, transformer, r, reducer)).fork();
5778	>	}
5779	>	for (Node<K,V> p; (p = advance()) != null; )
5780	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5781	>	result = r;
5782	>	CountedCompleter<?> c;
5783	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5784	>	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5785	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5786	>	s = t.rights;
5787	>	while (s != null) {
5788	>	t.result = reducer.applyAsLong(t.result, s.result);
5789	>	s = t.rights = s.nextRight;
5790	>	}
5791	>	}
5792	>	}
5793	>	}
5794	>	}
5795	>
5796	>	@SuppressWarnings("serial")
5797	>	static final class MapReduceMappingsToLongTask<K,V>
5798	>	extends BulkTask<K,V,Long> {
5799	>	final ToLongBiFunction<? super K, ? super V> transformer;
5800	>	final LongBinaryOperator reducer;
5801	>	final long basis;
5802	>	long result;
5803	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5804	>	MapReduceMappingsToLongTask
5805	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5806	>	MapReduceMappingsToLongTask<K,V> nextRight,
5807	>	ToLongBiFunction<? super K, ? super V> transformer,
5808	>	long basis,
5809	>	LongBinaryOperator reducer) {
5810	>	super(p, b, i, f, t); this.nextRight = nextRight;
5811	>	this.transformer = transformer;
5812	>	this.basis = basis; this.reducer = reducer;
5813	>	}
5814	>	public final Long getRawResult() { return result; }
5815	>	public final void compute() {
5816	>	final ToLongBiFunction<? super K, ? super V> transformer;
5817	>	final LongBinaryOperator reducer;
5818	>	if ((transformer = this.transformer) != null &&
5819	>	(reducer = this.reducer) != null) {
5820	>	long r = this.basis;
5821	>	for (int i = baseIndex, f, h; batch > 0 &&
5822	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5823	>	addToPendingCount(1);
5824	>	(rights = new MapReduceMappingsToLongTask<K,V>
5825	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5826	>	rights, transformer, r, reducer)).fork();
5827	>	}
5828	>	for (Node<K,V> p; (p = advance()) != null; )
5829	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
5830	>	result = r;
5831	>	CountedCompleter<?> c;
5832	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5833	>	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5834	>	t = (MapReduceMappingsToLongTask<K,V>)c,
5835	>	s = t.rights;
5836	>	while (s != null) {
5837	>	t.result = reducer.applyAsLong(t.result, s.result);
5838	>	s = t.rights = s.nextRight;
5839	>	}
5840	>	}
5841	>	}
5842	>	}
5843	>	}
5844	>
5845	>	@SuppressWarnings("serial")
5846	>	static final class MapReduceKeysToIntTask<K,V>
5847	>	extends BulkTask<K,V,Integer> {
5848	>	final ToIntFunction<? super K> transformer;
5849	>	final IntBinaryOperator reducer;
5850	>	final int basis;
5851	>	int result;
5852	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
5853	>	MapReduceKeysToIntTask
5854	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5855	>	MapReduceKeysToIntTask<K,V> nextRight,
5856	>	ToIntFunction<? super K> transformer,
5857	>	int basis,
5858	>	IntBinaryOperator reducer) {
5859	>	super(p, b, i, f, t); this.nextRight = nextRight;
5860	>	this.transformer = transformer;
5861	>	this.basis = basis; this.reducer = reducer;
5862	>	}
5863	>	public final Integer getRawResult() { return result; }
5864	>	public final void compute() {
5865	>	final ToIntFunction<? super K> transformer;
5866	>	final IntBinaryOperator reducer;
5867	>	if ((transformer = this.transformer) != null &&
5868	>	(reducer = this.reducer) != null) {
5869	>	int r = this.basis;
5870	>	for (int i = baseIndex, f, h; batch > 0 &&
5871	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5872	>	addToPendingCount(1);
5873	>	(rights = new MapReduceKeysToIntTask<K,V>
5874	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5875	>	rights, transformer, r, reducer)).fork();
5876	>	}
5877	>	for (Node<K,V> p; (p = advance()) != null; )
5878	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
5879	>	result = r;
5880	>	CountedCompleter<?> c;
5881	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5882	>	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5883	>	t = (MapReduceKeysToIntTask<K,V>)c,
5884	>	s = t.rights;
5885	>	while (s != null) {
5886	>	t.result = reducer.applyAsInt(t.result, s.result);
5887	>	s = t.rights = s.nextRight;
5888	>	}
5889	>	}
5890	>	}
5891	>	}
5892	>	}
5893	>
5894	>	@SuppressWarnings("serial")
5895	>	static final class MapReduceValuesToIntTask<K,V>
5896	>	extends BulkTask<K,V,Integer> {
5897	>	final ToIntFunction<? super V> transformer;
5898	>	final IntBinaryOperator reducer;
5899	>	final int basis;
5900	>	int result;
5901	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
5902	>	MapReduceValuesToIntTask
5903	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5904	>	MapReduceValuesToIntTask<K,V> nextRight,
5905	>	ToIntFunction<? super V> transformer,
5906	>	int basis,
5907	>	IntBinaryOperator reducer) {
5908	>	super(p, b, i, f, t); this.nextRight = nextRight;
5909	>	this.transformer = transformer;
5910	>	this.basis = basis; this.reducer = reducer;
5911	>	}
5912	>	public final Integer getRawResult() { return result; }
5913	>	public final void compute() {
5914	>	final ToIntFunction<? super V> transformer;
5915	>	final IntBinaryOperator reducer;
5916	>	if ((transformer = this.transformer) != null &&
5917	>	(reducer = this.reducer) != null) {
5918	>	int r = this.basis;
5919	>	for (int i = baseIndex, f, h; batch > 0 &&
5920	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5921	>	addToPendingCount(1);
5922	>	(rights = new MapReduceValuesToIntTask<K,V>
5923	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5924	>	rights, transformer, r, reducer)).fork();
5925	>	}
5926	>	for (Node<K,V> p; (p = advance()) != null; )
5927	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5928	>	result = r;
5929	>	CountedCompleter<?> c;
5930	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5931	>	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5932	>	t = (MapReduceValuesToIntTask<K,V>)c,
5933	>	s = t.rights;
5934	>	while (s != null) {
5935	>	t.result = reducer.applyAsInt(t.result, s.result);
5936	>	s = t.rights = s.nextRight;
5937	>	}
5938	>	}
5939	>	}
5940	>	}
5941	>	}
5942	>
5943	>	@SuppressWarnings("serial")
5944	>	static final class MapReduceEntriesToIntTask<K,V>
5945	>	extends BulkTask<K,V,Integer> {
5946	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5947	>	final IntBinaryOperator reducer;
5948	>	final int basis;
5949	>	int result;
5950	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5951	>	MapReduceEntriesToIntTask
5952	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5953	>	MapReduceEntriesToIntTask<K,V> nextRight,
5954	>	ToIntFunction<Map.Entry<K,V>> transformer,
5955	>	int basis,
5956	>	IntBinaryOperator reducer) {
5957	>	super(p, b, i, f, t); this.nextRight = nextRight;
5958	>	this.transformer = transformer;
5959	>	this.basis = basis; this.reducer = reducer;
5960	>	}
5961	>	public final Integer getRawResult() { return result; }
5962	>	public final void compute() {
5963	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5964	>	final IntBinaryOperator reducer;
5965	>	if ((transformer = this.transformer) != null &&
5966	>	(reducer = this.reducer) != null) {
5967	>	int r = this.basis;
5968	>	for (int i = baseIndex, f, h; batch > 0 &&
5969	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5970	>	addToPendingCount(1);
5971	>	(rights = new MapReduceEntriesToIntTask<K,V>
5972	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5973	>	rights, transformer, r, reducer)).fork();
5974	>	}
5975	>	for (Node<K,V> p; (p = advance()) != null; )
5976	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
5977	>	result = r;
5978	>	CountedCompleter<?> c;
5979	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5980	>	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
5981	>	t = (MapReduceEntriesToIntTask<K,V>)c,
5982	>	s = t.rights;
5983	>	while (s != null) {
5984	>	t.result = reducer.applyAsInt(t.result, s.result);
5985	>	s = t.rights = s.nextRight;
5986	>	}
5987	>	}
5988	>	}
5989	>	}
5990	>	}
5991	>
5992	>	@SuppressWarnings("serial")
5993	>	static final class MapReduceMappingsToIntTask<K,V>
5994	>	extends BulkTask<K,V,Integer> {
5995	>	final ToIntBiFunction<? super K, ? super V> transformer;
5996	>	final IntBinaryOperator reducer;
5997	>	final int basis;
5998	>	int result;
5999	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6000	>	MapReduceMappingsToIntTask
6001	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6002	>	MapReduceMappingsToIntTask<K,V> nextRight,
6003	>	ToIntBiFunction<? super K, ? super V> transformer,
6004	>	int basis,
6005	>	IntBinaryOperator reducer) {
6006	>	super(p, b, i, f, t); this.nextRight = nextRight;
6007	>	this.transformer = transformer;
6008	>	this.basis = basis; this.reducer = reducer;
6009	>	}
6010	>	public final Integer getRawResult() { return result; }
6011	>	public final void compute() {
6012	>	final ToIntBiFunction<? super K, ? super V> transformer;
6013	>	final IntBinaryOperator reducer;
6014	>	if ((transformer = this.transformer) != null &&
6015	>	(reducer = this.reducer) != null) {
6016	>	int r = this.basis;
6017	>	for (int i = baseIndex, f, h; batch > 0 &&
6018	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6019	>	addToPendingCount(1);
6020	>	(rights = new MapReduceMappingsToIntTask<K,V>
6021	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6022	>	rights, transformer, r, reducer)).fork();
6023	>	}
6024	>	for (Node<K,V> p; (p = advance()) != null; )
6025	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6026	>	result = r;
6027	>	CountedCompleter<?> c;
6028	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6029	>	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6030	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6031	>	s = t.rights;
6032	>	while (s != null) {
6033	>	t.result = reducer.applyAsInt(t.result, s.result);
6034	>	s = t.rights = s.nextRight;
6035	>	}
6036	>	}
6037	>	}
6038	>	}
6039	>	}
6040	>
6041	>	// Unsafe mechanics
6042	>	private static final sun.misc.Unsafe U;
6043	>	private static final long SIZECTL;
6044	>	private static final long TRANSFERINDEX;
6045	>	private static final long TRANSFERORIGIN;
6046	>	private static final long BASECOUNT;
6047	>	private static final long CELLSBUSY;
6048	>	private static final long CELLVALUE;
6049	>	private static final long ABASE;
6050	>	private static final int ASHIFT;
6051	>
6052	>	static {
6053	>	try {
6054	>	U = sun.misc.Unsafe.getUnsafe();
6055	>	Class<?> k = ConcurrentHashMap.class;
6056	>	SIZECTL = U.objectFieldOffset
6057	>	(k.getDeclaredField("sizeCtl"));
6058	>	TRANSFERINDEX = U.objectFieldOffset
6059	>	(k.getDeclaredField("transferIndex"));
6060	>	TRANSFERORIGIN = U.objectFieldOffset
6061	>	(k.getDeclaredField("transferOrigin"));
6062	>	BASECOUNT = U.objectFieldOffset
6063	>	(k.getDeclaredField("baseCount"));
6064	>	CELLSBUSY = U.objectFieldOffset
6065	>	(k.getDeclaredField("cellsBusy"));
6066	>	Class<?> ck = CounterCell.class;
6067	>	CELLVALUE = U.objectFieldOffset
6068	>	(ck.getDeclaredField("value"));
6069	>	Class<?> ak = Node[].class;
6070	>	ABASE = U.arrayBaseOffset(ak);
6071	>	int scale = U.arrayIndexScale(ak);
6072	>	if ((scale & (scale - 1)) != 0)
6073	>	throw new Error("data type scale not a power of two");
6074	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6075	>	} catch (Exception e) {
6076	>	throw new Error(e);
6077		}
6078		}
6079		}

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