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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.92 by dl, Sat Dec 2 20:55:01 2006 UTC vs.
Revision 1.292 by jsr166, Sat Apr 23 20:13:21 2016 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
16	>	import java.util.Enumeration;
17	>	import java.util.HashMap;
18	>	import java.util.Hashtable;
19	>	import java.util.Iterator;
20	>	import java.util.Map;
21	>	import java.util.NoSuchElementException;
22	>	import java.util.Set;
23	>	import java.util.Spliterator;
24	>	import java.util.concurrent.atomic.AtomicReference;
25	>	import java.util.concurrent.locks.LockSupport;
26	>	import java.util.concurrent.locks.ReentrantLock;
27	>	import java.util.function.BiConsumer;
28	>	import java.util.function.BiFunction;
29	>	import java.util.function.Consumer;
30	>	import java.util.function.DoubleBinaryOperator;
31	>	import java.util.function.Function;
32	>	import java.util.function.IntBinaryOperator;
33	>	import java.util.function.LongBinaryOperator;
34	>	import java.util.function.Predicate;
35	>	import java.util.function.ToDoubleBiFunction;
36	>	import java.util.function.ToDoubleFunction;
37	>	import java.util.function.ToIntBiFunction;
38	>	import java.util.function.ToIntFunction;
39	>	import java.util.function.ToLongBiFunction;
40	>	import java.util.function.ToLongFunction;
41	>	import java.util.stream.Stream;
42
43		/**
44		* A hash table supporting full concurrency of retrievals and
45	<	* adjustable expected concurrency for updates. This class obeys the
45	>	* high expected concurrency for updates. This class obeys the
46		* same functional specification as {@link java.util.Hashtable}, and
47		* includes versions of methods corresponding to each method of
48	<	* <tt>Hashtable</tt>. However, even though all operations are
48	>	* {@code Hashtable}. However, even though all operations are
49		* thread-safe, retrieval operations do <em>not</em> entail locking,
50		* and there is <em>not</em> any support for locking the entire table
51		* in a way that prevents all access.  This class is fully
52	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
52	>	* interoperable with {@code Hashtable} in programs that rely on its
53		* thread safety but not on its synchronization details.
54		*
55	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
56	<	* block, so may overlap with update operations (including
57	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
58	<	* of the most recently <em>completed</em> update operations holding
59	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
60	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
61	<	* removal of only some entries.  Similarly, Iterators and
62	<	* Enumerations return elements reflecting the state of the hash table
63	<	* at some point at or since the creation of the iterator/enumeration.
64	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
55	>	* <p>Retrieval operations (including {@code get}) generally do not
56	>	* block, so may overlap with update operations (including {@code put}
57	>	* and {@code remove}). Retrievals reflect the results of the most
58	>	* recently <em>completed</em> update operations holding upon their
59	>	* onset. (More formally, an update operation for a given key bears a
60	>	* <em>happens-before</em> relation with any (non-null) retrieval for
61	>	* that key reporting the updated value.)  For aggregate operations
62	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
63	>	* reflect insertion or removal of only some entries.  Similarly,
64	>	* Iterators, Spliterators and Enumerations return elements reflecting the
65	>	* state of the hash table at some point at or since the creation of the
66	>	* iterator/enumeration.  They do <em>not</em> throw {@link
67	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
68		* However, iterators are designed to be used by only one thread at a time.
69	+	* Bear in mind that the results of aggregate status methods including
70	+	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
71	+	* useful only when a map is not undergoing concurrent updates in other threads.
72	+	* Otherwise the results of these methods reflect transient states
73	+	* that may be adequate for monitoring or estimation purposes, but not
74	+	* for program control.
75	+	*
76	+	* <p>The table is dynamically expanded when there are too many
77	+	* collisions (i.e., keys that have distinct hash codes but fall into
78	+	* the same slot modulo the table size), with the expected average
79	+	* effect of maintaining roughly two bins per mapping (corresponding
80	+	* to a 0.75 load factor threshold for resizing). There may be much
81	+	* variance around this average as mappings are added and removed, but
82	+	* overall, this maintains a commonly accepted time/space tradeoff for
83	+	* hash tables.  However, resizing this or any other kind of hash
84	+	* table may be a relatively slow operation. When possible, it is a
85	+	* good idea to provide a size estimate as an optional {@code
86	+	* initialCapacity} constructor argument. An additional optional
87	+	* {@code loadFactor} constructor argument provides a further means of
88	+	* customizing initial table capacity by specifying the table density
89	+	* to be used in calculating the amount of space to allocate for the
90	+	* given number of elements.  Also, for compatibility with previous
91	+	* versions of this class, constructors may optionally specify an
92	+	* expected {@code concurrencyLevel} as an additional hint for
93	+	* internal sizing.  Note that using many keys with exactly the same
94	+	* {@code hashCode()} is a sure way to slow down performance of any
95	+	* hash table. To ameliorate impact, when keys are {@link Comparable},
96	+	* this class may use comparison order among keys to help break ties.
97	+	*
98	+	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
99	+	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
100	+	* (using {@link #keySet(Object)} when only keys are of interest, and the
101	+	* mapped values are (perhaps transiently) not used or all take the
102	+	* same mapping value.
103		*
104	<	* <p> The allowed concurrency among update operations is guided by
105	<	* the optional <tt>concurrencyLevel</tt> constructor argument
106	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
107	<	* table is internally partitioned to try to permit the indicated
108	<	* number of concurrent updates without contention. Because placement
109	<	* in hash tables is essentially random, the actual concurrency will
45	<	* vary.  Ideally, you should choose a value to accommodate as many
46	<	* threads as will ever concurrently modify the table. Using a
47	<	* significantly higher value than you need can waste space and time,
48	<	* and a significantly lower value can lead to thread contention. But
49	<	* overestimates and underestimates within an order of magnitude do
50	<	* not usually have much noticeable impact. A value of one is
51	<	* appropriate when it is known that only one thread will modify and
52	<	* all others will only read. Also, resizing this or any other kind of
53	<	* hash table is a relatively slow operation, so, when possible, it is
54	<	* a good idea to provide estimates of expected table sizes in
55	<	* constructors.
104	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
105	>	* form of histogram or multiset) by using {@link
106	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
107	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
108	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
109	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
110		*
111		* <p>This class and its views and iterators implement all of the
112		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
113		* interfaces.
114		*
115	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
116	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
115	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
116	>	* does <em>not</em> allow {@code null} to be used as a key or value.
117	>	*
118	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
119	>	* operations that, unlike most {@link Stream} methods, are designed
120	>	* to be safely, and often sensibly, applied even with maps that are
121	>	* being concurrently updated by other threads; for example, when
122	>	* computing a snapshot summary of the values in a shared registry.
123	>	* There are three kinds of operation, each with four forms, accepting
124	>	* functions with keys, values, entries, and (key, value) pairs as
125	>	* arguments and/or return values. Because the elements of a
126	>	* ConcurrentHashMap are not ordered in any particular way, and may be
127	>	* processed in different orders in different parallel executions, the
128	>	* correctness of supplied functions should not depend on any
129	>	* ordering, or on any other objects or values that may transiently
130	>	* change while computation is in progress; and except for forEach
131	>	* actions, should ideally be side-effect-free. Bulk operations on
132	>	* {@link java.util.Map.Entry} objects do not support method {@code
133	>	* setValue}.
134	>	*
135	>	* <ul>
136	>	* <li>forEach: Performs a given action on each element.
137	>	* A variant form applies a given transformation on each element
138	>	* before performing the action.
139	>	*
140	>	* <li>search: Returns the first available non-null result of
141	>	* applying a given function on each element; skipping further
142	>	* search when a result is found.
143	>	*
144	>	* <li>reduce: Accumulates each element.  The supplied reduction
145	>	* function cannot rely on ordering (more formally, it should be
146	>	* both associative and commutative).  There are five variants:
147	>	*
148	>	* <ul>
149	>	*
150	>	* <li>Plain reductions. (There is not a form of this method for
151	>	* (key, value) function arguments since there is no corresponding
152	>	* return type.)
153	>	*
154	>	* <li>Mapped reductions that accumulate the results of a given
155	>	* function applied to each element.
156	>	*
157	>	* <li>Reductions to scalar doubles, longs, and ints, using a
158	>	* given basis value.
159	>	*
160	>	* </ul>
161	>	* </ul>
162	>	*
163	>	* <p>These bulk operations accept a {@code parallelismThreshold}
164	>	* argument. Methods proceed sequentially if the current map size is
165	>	* estimated to be less than the given threshold. Using a value of
166	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
167	>	* of {@code 1} results in maximal parallelism by partitioning into
168	>	* enough subtasks to fully utilize the {@link
169	>	* ForkJoinPool#commonPool()} that is used for all parallel
170	>	* computations. Normally, you would initially choose one of these
171	>	* extreme values, and then measure performance of using in-between
172	>	* values that trade off overhead versus throughput.
173	>	*
174	>	* <p>The concurrency properties of bulk operations follow
175	>	* from those of ConcurrentHashMap: Any non-null result returned
176	>	* from {@code get(key)} and related access methods bears a
177	>	* happens-before relation with the associated insertion or
178	>	* update.  The result of any bulk operation reflects the
179	>	* composition of these per-element relations (but is not
180	>	* necessarily atomic with respect to the map as a whole unless it
181	>	* is somehow known to be quiescent).  Conversely, because keys
182	>	* and values in the map are never null, null serves as a reliable
183	>	* atomic indicator of the current lack of any result.  To
184	>	* maintain this property, null serves as an implicit basis for
185	>	* all non-scalar reduction operations. For the double, long, and
186	>	* int versions, the basis should be one that, when combined with
187	>	* any other value, returns that other value (more formally, it
188	>	* should be the identity element for the reduction). Most common
189	>	* reductions have these properties; for example, computing a sum
190	>	* with basis 0 or a minimum with basis MAX_VALUE.
191	>	*
192	>	* <p>Search and transformation functions provided as arguments
193	>	* should similarly return null to indicate the lack of any result
194	>	* (in which case it is not used). In the case of mapped
195	>	* reductions, this also enables transformations to serve as
196	>	* filters, returning null (or, in the case of primitive
197	>	* specializations, the identity basis) if the element should not
198	>	* be combined. You can create compound transformations and
199	>	* filterings by composing them yourself under this "null means
200	>	* there is nothing there now" rule before using them in search or
201	>	* reduce operations.
202	>	*
203	>	* <p>Methods accepting and/or returning Entry arguments maintain
204	>	* key-value associations. They may be useful for example when
205	>	* finding the key for the greatest value. Note that "plain" Entry
206	>	* arguments can be supplied using {@code new
207	>	* AbstractMap.SimpleEntry(k,v)}.
208	>	*
209	>	* <p>Bulk operations may complete abruptly, throwing an
210	>	* exception encountered in the application of a supplied
211	>	* function. Bear in mind when handling such exceptions that other
212	>	* concurrently executing functions could also have thrown
213	>	* exceptions, or would have done so if the first exception had
214	>	* not occurred.
215	>	*
216	>	* <p>Speedups for parallel compared to sequential forms are common
217	>	* but not guaranteed.  Parallel operations involving brief functions
218	>	* on small maps may execute more slowly than sequential forms if the
219	>	* underlying work to parallelize the computation is more expensive
220	>	* than the computation itself.  Similarly, parallelization may not
221	>	* lead to much actual parallelism if all processors are busy
222	>	* performing unrelated tasks.
223	>	*
224	>	* <p>All arguments to all task methods must be non-null.
225		*
226		* <p>This class is a member of the
227		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 232 | import java.io.ObjectOutputStream;
232		* @param <K> the type of keys maintained by this map
233		* @param <V> the type of mapped values
234		*/
235	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
236	<	implements ConcurrentMap<K, V>, Serializable {
235	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
236	>	implements ConcurrentMap<K,V>, Serializable {
237		private static final long serialVersionUID = 7249069246763182397L;
238
239		/*
240	<	* The basic strategy is to subdivide the table among Segments,
241	<	* each of which itself is a concurrently readable hash table.
240	>	* Overview:
241	>	*
242	>	* The primary design goal of this hash table is to maintain
243	>	* concurrent readability (typically method get(), but also
244	>	* iterators and related methods) while minimizing update
245	>	* contention. Secondary goals are to keep space consumption about
246	>	* the same or better than java.util.HashMap, and to support high
247	>	* initial insertion rates on an empty table by many threads.
248	>	*
249	>	* This map usually acts as a binned (bucketed) hash table.  Each
250	>	* key-value mapping is held in a Node.  Most nodes are instances
251	>	* of the basic Node class with hash, key, value, and next
252	>	* fields. However, various subclasses exist: TreeNodes are
253	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
254	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
255	>	* of bins during resizing. ReservationNodes are used as
256	>	* placeholders while establishing values in computeIfAbsent and
257	>	* related methods.  The types TreeBin, ForwardingNode, and
258	>	* ReservationNode do not hold normal user keys, values, or
259	>	* hashes, and are readily distinguishable during search etc
260	>	* because they have negative hash fields and null key and value
261	>	* fields. (These special nodes are either uncommon or transient,
262	>	* so the impact of carrying around some unused fields is
263	>	* insignificant.)
264	>	*
265	>	* The table is lazily initialized to a power-of-two size upon the
266	>	* first insertion.  Each bin in the table normally contains a
267	>	* list of Nodes (most often, the list has only zero or one Node).
268	>	* Table accesses require volatile/atomic reads, writes, and
269	>	* CASes.  Because there is no other way to arrange this without
270	>	* adding further indirections, we use intrinsics
271	>	* (jdk.internal.misc.Unsafe) operations.
272	>	*
273	>	* We use the top (sign) bit of Node hash fields for control
274	>	* purposes -- it is available anyway because of addressing
275	>	* constraints.  Nodes with negative hash fields are specially
276	>	* handled or ignored in map methods.
277	>	*
278	>	* Insertion (via put or its variants) of the first node in an
279	>	* empty bin is performed by just CASing it to the bin.  This is
280	>	* by far the most common case for put operations under most
281	>	* key/hash distributions.  Other update operations (insert,
282	>	* delete, and replace) require locks.  We do not want to waste
283	>	* the space required to associate a distinct lock object with
284	>	* each bin, so instead use the first node of a bin list itself as
285	>	* a lock. Locking support for these locks relies on builtin
286	>	* "synchronized" monitors.
287	>	*
288	>	* Using the first node of a list as a lock does not by itself
289	>	* suffice though: When a node is locked, any update must first
290	>	* validate that it is still the first node after locking it, and
291	>	* retry if not. Because new nodes are always appended to lists,
292	>	* once a node is first in a bin, it remains first until deleted
293	>	* or the bin becomes invalidated (upon resizing).
294	>	*
295	>	* The main disadvantage of per-bin locks is that other update
296	>	* operations on other nodes in a bin list protected by the same
297	>	* lock can stall, for example when user equals() or mapping
298	>	* functions take a long time.  However, statistically, under
299	>	* random hash codes, this is not a common problem.  Ideally, the
300	>	* frequency of nodes in bins follows a Poisson distribution
301	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
302	>	* parameter of about 0.5 on average, given the resizing threshold
303	>	* of 0.75, although with a large variance because of resizing
304	>	* granularity. Ignoring variance, the expected occurrences of
305	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
306	>	* first values are:
307	>	*
308	>	* 0:    0.60653066
309	>	* 1:    0.30326533
310	>	* 2:    0.07581633
311	>	* 3:    0.01263606
312	>	* 4:    0.00157952
313	>	* 5:    0.00015795
314	>	* 6:    0.00001316
315	>	* 7:    0.00000094
316	>	* 8:    0.00000006
317	>	* more: less than 1 in ten million
318	>	*
319	>	* Lock contention probability for two threads accessing distinct
320	>	* elements is roughly 1 / (8 * #elements) under random hashes.
321	>	*
322	>	* Actual hash code distributions encountered in practice
323	>	* sometimes deviate significantly from uniform randomness.  This
324	>	* includes the case when N > (1<<30), so some keys MUST collide.
325	>	* Similarly for dumb or hostile usages in which multiple keys are
326	>	* designed to have identical hash codes or ones that differs only
327	>	* in masked-out high bits. So we use a secondary strategy that
328	>	* applies when the number of nodes in a bin exceeds a
329	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
330	>	* specialized form of red-black trees), bounding search time to
331	>	* O(log N).  Each search step in a TreeBin is at least twice as
332	>	* slow as in a regular list, but given that N cannot exceed
333	>	* (1<<64) (before running out of addresses) this bounds search
334	>	* steps, lock hold times, etc, to reasonable constants (roughly
335	>	* 100 nodes inspected per operation worst case) so long as keys
336	>	* are Comparable (which is very common -- String, Long, etc).
337	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
338	>	* traversal pointers as regular nodes, so can be traversed in
339	>	* iterators in the same way.
340	>	*
341	>	* The table is resized when occupancy exceeds a percentage
342	>	* threshold (nominally, 0.75, but see below).  Any thread
343	>	* noticing an overfull bin may assist in resizing after the
344	>	* initiating thread allocates and sets up the replacement array.
345	>	* However, rather than stalling, these other threads may proceed
346	>	* with insertions etc.  The use of TreeBins shields us from the
347	>	* worst case effects of overfilling while resizes are in
348	>	* progress.  Resizing proceeds by transferring bins, one by one,
349	>	* from the table to the next table. However, threads claim small
350	>	* blocks of indices to transfer (via field transferIndex) before
351	>	* doing so, reducing contention.  A generation stamp in field
352	>	* sizeCtl ensures that resizings do not overlap. Because we are
353	>	* using power-of-two expansion, the elements from each bin must
354	>	* either stay at same index, or move with a power of two
355	>	* offset. We eliminate unnecessary node creation by catching
356	>	* cases where old nodes can be reused because their next fields
357	>	* won't change.  On average, only about one-sixth of them need
358	>	* cloning when a table doubles. The nodes they replace will be
359	>	* garbage collectable as soon as they are no longer referenced by
360	>	* any reader thread that may be in the midst of concurrently
361	>	* traversing table.  Upon transfer, the old table bin contains
362	>	* only a special forwarding node (with hash field "MOVED") that
363	>	* contains the next table as its key. On encountering a
364	>	* forwarding node, access and update operations restart, using
365	>	* the new table.
366	>	*
367	>	* Each bin transfer requires its bin lock, which can stall
368	>	* waiting for locks while resizing. However, because other
369	>	* threads can join in and help resize rather than contend for
370	>	* locks, average aggregate waits become shorter as resizing
371	>	* progresses.  The transfer operation must also ensure that all
372	>	* accessible bins in both the old and new table are usable by any
373	>	* traversal.  This is arranged in part by proceeding from the
374	>	* last bin (table.length - 1) up towards the first.  Upon seeing
375	>	* a forwarding node, traversals (see class Traverser) arrange to
376	>	* move to the new table without revisiting nodes.  To ensure that
377	>	* no intervening nodes are skipped even when moved out of order,
378	>	* a stack (see class TableStack) is created on first encounter of
379	>	* a forwarding node during a traversal, to maintain its place if
380	>	* later processing the current table. The need for these
381	>	* save/restore mechanics is relatively rare, but when one
382	>	* forwarding node is encountered, typically many more will be.
383	>	* So Traversers use a simple caching scheme to avoid creating so
384	>	* many new TableStack nodes. (Thanks to Peter Levart for
385	>	* suggesting use of a stack here.)
386	>	*
387	>	* The traversal scheme also applies to partial traversals of
388	>	* ranges of bins (via an alternate Traverser constructor)
389	>	* to support partitioned aggregate operations.  Also, read-only
390	>	* operations give up if ever forwarded to a null table, which
391	>	* provides support for shutdown-style clearing, which is also not
392	>	* currently implemented.
393	>	*
394	>	* Lazy table initialization minimizes footprint until first use,
395	>	* and also avoids resizings when the first operation is from a
396	>	* putAll, constructor with map argument, or deserialization.
397	>	* These cases attempt to override the initial capacity settings,
398	>	* but harmlessly fail to take effect in cases of races.
399	>	*
400	>	* The element count is maintained using a specialization of
401	>	* LongAdder. We need to incorporate a specialization rather than
402	>	* just use a LongAdder in order to access implicit
403	>	* contention-sensing that leads to creation of multiple
404	>	* CounterCells.  The counter mechanics avoid contention on
405	>	* updates but can encounter cache thrashing if read too
406	>	* frequently during concurrent access. To avoid reading so often,
407	>	* resizing under contention is attempted only upon adding to a
408	>	* bin already holding two or more nodes. Under uniform hash
409	>	* distributions, the probability of this occurring at threshold
410	>	* is around 13%, meaning that only about 1 in 8 puts check
411	>	* threshold (and after resizing, many fewer do so).
412	>	*
413	>	* TreeBins use a special form of comparison for search and
414	>	* related operations (which is the main reason we cannot use
415	>	* existing collections such as TreeMaps). TreeBins contain
416	>	* Comparable elements, but may contain others, as well as
417	>	* elements that are Comparable but not necessarily Comparable for
418	>	* the same T, so we cannot invoke compareTo among them. To handle
419	>	* this, the tree is ordered primarily by hash value, then by
420	>	* Comparable.compareTo order if applicable.  On lookup at a node,
421	>	* if elements are not comparable or compare as 0 then both left
422	>	* and right children may need to be searched in the case of tied
423	>	* hash values. (This corresponds to the full list search that
424	>	* would be necessary if all elements were non-Comparable and had
425	>	* tied hashes.) On insertion, to keep a total ordering (or as
426	>	* close as is required here) across rebalancings, we compare
427	>	* classes and identityHashCodes as tie-breakers. The red-black
428	>	* balancing code is updated from pre-jdk-collections
429	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
430	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
431	>	* Algorithms" (CLR).
432	>	*
433	>	* TreeBins also require an additional locking mechanism.  While
434	>	* list traversal is always possible by readers even during
435	>	* updates, tree traversal is not, mainly because of tree-rotations
436	>	* that may change the root node and/or its linkages.  TreeBins
437	>	* include a simple read-write lock mechanism parasitic on the
438	>	* main bin-synchronization strategy: Structural adjustments
439	>	* associated with an insertion or removal are already bin-locked
440	>	* (and so cannot conflict with other writers) but must wait for
441	>	* ongoing readers to finish. Since there can be only one such
442	>	* waiter, we use a simple scheme using a single "waiter" field to
443	>	* block writers.  However, readers need never block.  If the root
444	>	* lock is held, they proceed along the slow traversal path (via
445	>	* next-pointers) until the lock becomes available or the list is
446	>	* exhausted, whichever comes first. These cases are not fast, but
447	>	* maximize aggregate expected throughput.
448	>	*
449	>	* Maintaining API and serialization compatibility with previous
450	>	* versions of this class introduces several oddities. Mainly: We
451	>	* leave untouched but unused constructor arguments referring to
452	>	* concurrencyLevel. We accept a loadFactor constructor argument,
453	>	* but apply it only to initial table capacity (which is the only
454	>	* time that we can guarantee to honor it.) We also declare an
455	>	* unused "Segment" class that is instantiated in minimal form
456	>	* only when serializing.
457	>	*
458	>	* Also, solely for compatibility with previous versions of this
459	>	* class, it extends AbstractMap, even though all of its methods
460	>	* are overridden, so it is just useless baggage.
461	>	*
462	>	* This file is organized to make things a little easier to follow
463	>	* while reading than they might otherwise: First the main static
464	>	* declarations and utilities, then fields, then main public
465	>	* methods (with a few factorings of multiple public methods into
466	>	* internal ones), then sizing methods, trees, traversers, and
467	>	* bulk operations.
468		*/
469
470		/* ---------------- Constants -------------- */
471
472		/**
473	<	* The default initial capacity for this table,
474	<	* used when not otherwise specified in a constructor.
473	>	* The largest possible table capacity.  This value must be
474	>	* exactly 1<<30 to stay within Java array allocation and indexing
475	>	* bounds for power of two table sizes, and is further required
476	>	* because the top two bits of 32bit hash fields are used for
477	>	* control purposes.
478		*/
479	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
479	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
480
481		/**
482	<	* The default load factor for this table, used when not
483	<	* otherwise specified in a constructor.
482	>	* The default initial table capacity.  Must be a power of 2
483	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
484		*/
485	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
485	>	private static final int DEFAULT_CAPACITY = 16;
486
487		/**
488	<	* The default concurrency level for this table, used when not
489	<	* otherwise specified in a constructor.
488	>	* The largest possible (non-power of two) array size.
489	>	* Needed by toArray and related methods.
490		*/
491	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
491	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
492
493		/**
494	<	* The maximum capacity, used if a higher value is implicitly
495	<	* 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.
494	>	* The default concurrency level for this table. Unused but
495	>	* defined for compatibility with previous versions of this class.
496		*/
497	<	static final int MAXIMUM_CAPACITY = 1 << 30;
497	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
498
499		/**
500	<	* The maximum number of segments to allow; used to bound
501	<	* constructor arguments.
500	>	* The load factor for this table. Overrides of this value in
501	>	* constructors affect only the initial table capacity.  The
502	>	* actual floating point value isn't normally used -- it is
503	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
504	>	* the associated resizing threshold.
505		*/
506	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
506	>	private static final float LOAD_FACTOR = 0.75f;
507
508		/**
509	<	* Number of unsynchronized retries in size and containsValue
510	<	* methods before resorting to locking. This is used to avoid
511	<	* unbounded retries if tables undergo continuous modification
512	<	* which would make it impossible to obtain an accurate result.
509	>	* The bin count threshold for using a tree rather than list for a
510	>	* bin.  Bins are converted to trees when adding an element to a
511	>	* bin with at least this many nodes. The value must be greater
512	>	* than 2, and should be at least 8 to mesh with assumptions in
513	>	* tree removal about conversion back to plain bins upon
514	>	* shrinkage.
515		*/
516	<	static final int RETRIES_BEFORE_LOCK = 2;
123	<
124	<	/* ---------------- Fields -------------- */
516	>	static final int TREEIFY_THRESHOLD = 8;
517
518		/**
519	<	* Mask value for indexing into segments. The upper bits of a
520	<	* key's hash code are used to choose the segment.
519	>	* The bin count threshold for untreeifying a (split) bin during a
520	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
521	>	* most 6 to mesh with shrinkage detection under removal.
522		*/
523	<	final int segmentMask;
523	>	static final int UNTREEIFY_THRESHOLD = 6;
524
525		/**
526	<	* Shift value for indexing within segments.
526	>	* The smallest table capacity for which bins may be treeified.
527	>	* (Otherwise the table is resized if too many nodes in a bin.)
528	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
529	>	* conflicts between resizing and treeification thresholds.
530		*/
531	<	final int segmentShift;
531	>	static final int MIN_TREEIFY_CAPACITY = 64;
532
533		/**
534	<	* The segments, each of which is a specialized hash table
534	>	* Minimum number of rebinnings per transfer step. Ranges are
535	>	* subdivided to allow multiple resizer threads.  This value
536	>	* serves as a lower bound to avoid resizers encountering
537	>	* excessive memory contention.  The value should be at least
538	>	* DEFAULT_CAPACITY.
539		*/
540	<	final Segment<K,V>[] segments;
141	<
142	<	transient Set<K> keySet;
143	<	transient Set<Map.Entry<K,V>> entrySet;
144	<	transient Collection<V> values;
145	<
146	<	/* ---------------- Small Utilities -------------- */
540	>	private static final int MIN_TRANSFER_STRIDE = 16;
541
542		/**
543	<	* Applies a supplemental hash function to a given hashCode, which
544	<	* 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.
543	>	* The number of bits used for generation stamp in sizeCtl.
544	>	* Must be at least 6 for 32bit arrays.
545		*/
546	<	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	<	}
546	>	private static final int RESIZE_STAMP_BITS = 16;
547
548		/**
549	<	* Returns the segment that should be used for key with given hash
550	<	* @param hash the hash code for the key
169	<	* @return the segment
549	>	* The maximum number of threads that can help resize.
550	>	* Must fit in 32 - RESIZE_STAMP_BITS bits.
551		*/
552	<	final Segment<K,V> segmentFor(int hash) {
172	<	return segments[(hash >>> segmentShift) & segmentMask];
173	<	}
174	<
175	<	/* ---------------- Inner Classes -------------- */
552	>	private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
553
554		/**
555	<	* ConcurrentHashMap list entry. Note that this is never exported
179	<	* out as a user-visible Map.Entry.
180	<	*
181	<	* Because the value field is volatile, not final, it is legal wrt
182	<	* the Java Memory Model for an unsynchronized reader to see null
183	<	* 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.
555	>	* The bit shift for recording size stamp in sizeCtl.
556		*/
557	<	static final class HashEntry<K,V> {
190	<	final K key;
191	<	final int hash;
192	<	volatile V value;
193	<	final HashEntry<K,V> next;
194	<
195	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
196	<	this.key = key;
197	<	this.hash = hash;
198	<	this.next = next;
199	<	this.value = value;
200	<	}
557	>	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
558
559	<	@SuppressWarnings("unchecked")
560	<	static final <K,V> HashEntry<K,V>[] newArray(int i) {
204	<	return new HashEntry[i];
205	<	}
206	<	}
207	<
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.
559	>	/*
560	>	* Encodings for Node hash fields. See above for explanation.
561		*/
562	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
563	<	/*
564	<	* Segments maintain a table of entry lists that are ALWAYS
565	<	* 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;
562	>	static final int MOVED     = -1; // hash for forwarding nodes
563	>	static final int TREEBIN   = -2; // hash for roots of trees
564	>	static final int RESERVED  = -3; // hash for transient reservations
565	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
566
567	<	/**
568	<	* 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;
567	>	/** Number of CPUS, to place bounds on some sizings */
568	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
569
570	<	/**
571	<	* The table is rehashed when its size exceeds this threshold.
572	<	* (The value of this field is always <tt>(int)(capacity *
573	<	* loadFactor)</tt>.)
574	<	*/
575	<	transient int threshold;
570	>	/**
571	>	* Serialized pseudo-fields, provided only for jdk7 compatibility.
572	>	* @serialField segments Segment[]
573	>	*   The segments, each of which is a specialized hash table.
574	>	* @serialField segmentMask int
575	>	*   Mask value for indexing into segments. The upper bits of a
576	>	*   key's hash code are used to choose the segment.
577	>	* @serialField segmentShift int
578	>	*   Shift value for indexing within segments.
579	>	*/
580	>	private static final ObjectStreamField[] serialPersistentFields = {
581	>	new ObjectStreamField("segments", Segment[].class),
582	>	new ObjectStreamField("segmentMask", Integer.TYPE),
583	>	new ObjectStreamField("segmentShift", Integer.TYPE),
584	>	};
585
586	<	/**
276	<	* The per-segment table.
277	<	*/
278	<	transient volatile HashEntry<K,V>[] table;
586	>	/* ---------------- Nodes -------------- */
587
588	<	/**
589	<	* The load factor for the hash table.  Even though this value
590	<	* is same for all segments, it is replicated to avoid needing
591	<	* links to outer object.
592	<	* @serial
593	<	*/
594	<	final float loadFactor;
588	>	/**
589	>	* Key-value entry.  This class is never exported out as a
590	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
591	>	* MapEntry below), but can be used for read-only traversals used
592	>	* in bulk tasks.  Subclasses of Node with a negative hash field
593	>	* are special, and contain null keys and values (but are never
594	>	* exported).  Otherwise, keys and vals are never null.
595	>	*/
596	>	static class Node<K,V> implements Map.Entry<K,V> {
597	>	final int hash;
598	>	final K key;
599	>	volatile V val;
600	>	volatile Node<K,V> next;
601
602	<	Segment(int initialCapacity, float lf) {
603	<	loadFactor = lf;
604	<	setTable(HashEntry.<K,V>newArray(initialCapacity));
602	>	Node(int hash, K key, V val) {
603	>	this.hash = hash;
604	>	this.key = key;
605	>	this.val = val;
606		}
607
608	<	@SuppressWarnings("unchecked")
609	<	static final <K,V> Segment<K,V>[] newArray(int i) {
610	<	return new Segment[i];
608	>	Node(int hash, K key, V val, Node<K,V> next) {
609	>	this(hash, key, val);
610	>	this.next = next;
611		}
612
613	<	/**
614	<	* Sets table to new HashEntry array.
615	<	* Call only while holding lock or in constructor.
616	<	*/
617	<	void setTable(HashEntry<K,V>[] newTable) {
618	<	threshold = (int)(newTable.length * loadFactor);
619	<	table = newTable;
613	>	public final K getKey()     { return key; }
614	>	public final V getValue()   { return val; }
615	>	public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
616	>	public final String toString() {
617	>	return Helpers.mapEntryToString(key, val);
618	>	}
619	>	public final V setValue(V value) {
620	>	throw new UnsupportedOperationException();
621	>	}
622	>
623	>	public final boolean equals(Object o) {
624	>	Object k, v, u; Map.Entry<?,?> e;
625	>	return ((o instanceof Map.Entry) &&
626	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
627	>	(v = e.getValue()) != null &&
628	>	(k == key || k.equals(key)) &&
629	>	(v == (u = val) || v.equals(u)));
630		}
631
632		/**
633	<	* Returns properly casted first entry of bin for given hash.
633	>	* Virtualized support for map.get(); overridden in subclasses.
634		*/
635	<	HashEntry<K,V> getFirst(int hash) {
636	<	HashEntry<K,V>[] tab = table;
637	<	return tab[hash & (tab.length - 1)];
638	<	}
639	<
640	<	/**
641	<	* Reads value field of an entry under lock. Called if value
642	<	* field ever appears to be null. This is possible only if a
643	<	* 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();
328	<	}
329	<	}
330	<
331	<	/* Specialized implementations of map methods */
332	<
333	<	V get(Object key, int hash) {
334	<	if (count != 0) { // read-volatile
335	<	HashEntry<K,V> e = getFirst(hash);
336	<	while (e != null) {
337	<	if (e.hash == hash && key.equals(e.key)) {
338	<	V v = e.value;
339	<	if (v != null)
340	<	return v;
341	<	return readValueUnderLock(e); // recheck
342	<	}
343	<	e = e.next;
344	<	}
635	>	Node<K,V> find(int h, Object k) {
636	>	Node<K,V> e = this;
637	>	if (k != null) {
638	>	do {
639	>	K ek;
640	>	if (e.hash == h &&
641	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
642	>	return e;
643	>	} while ((e = e.next) != null);
644		}
645		return null;
646		}
647	+	}
648
649	<	boolean containsKey(Object key, int hash) {
350	<	if (count != 0) { // read-volatile
351	<	HashEntry<K,V> e = getFirst(hash);
352	<	while (e != null) {
353	<	if (e.hash == hash && key.equals(e.key))
354	<	return true;
355	<	e = e.next;
356	<	}
357	<	}
358	<	return false;
359	<	}
649	>	/* ---------------- Static utilities -------------- */
650
651	<	boolean containsValue(Object value) {
652	<	if (count != 0) { // read-volatile
653	<	HashEntry<K,V>[] tab = table;
654	<	int len = tab.length;
655	<	for (int i = 0 ; i < len; i++) {
656	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
657	<	V v = e.value;
658	<	if (v == null) // recheck
659	<	v = readValueUnderLock(e);
660	<	if (value.equals(v))
661	<	return true;
662	<	}
663	<	}
664	<	}
665	<	return false;
666	<	}
651	>	/**
652	>	* Spreads (XORs) higher bits of hash to lower and also forces top
653	>	* bit to 0. Because the table uses power-of-two masking, sets of
654	>	* hashes that vary only in bits above the current mask will
655	>	* always collide. (Among known examples are sets of Float keys
656	>	* holding consecutive whole numbers in small tables.)  So we
657	>	* apply a transform that spreads the impact of higher bits
658	>	* downward. There is a tradeoff between speed, utility, and
659	>	* quality of bit-spreading. Because many common sets of hashes
660	>	* are already reasonably distributed (so don't benefit from
661	>	* spreading), and because we use trees to handle large sets of
662	>	* collisions in bins, we just XOR some shifted bits in the
663	>	* cheapest possible way to reduce systematic lossage, as well as
664	>	* to incorporate impact of the highest bits that would otherwise
665	>	* never be used in index calculations because of table bounds.
666	>	*/
667	>	static final int spread(int h) {
668	>	return (h ^ (h >>> 16)) & HASH_BITS;
669	>	}
670
671	<	boolean replace(K key, int hash, V oldValue, V newValue) {
672	<	lock();
673	<	try {
674	<	HashEntry<K,V> e = getFirst(hash);
675	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
676	<	e = e.next;
677	<
678	<	boolean replaced = false;
679	<	if (e != null && oldValue.equals(e.value)) {
680	<	replaced = true;
681	<	e.value = newValue;
682	<	}
683	<	return replaced;
391	<	} finally {
392	<	unlock();
393	<	}
394	<	}
671	>	/**
672	>	* Returns a power of two table size for the given desired capacity.
673	>	* See Hackers Delight, sec 3.2
674	>	*/
675	>	private static final int tableSizeFor(int c) {
676	>	int n = c - 1;
677	>	n |= n >>> 1;
678	>	n |= n >>> 2;
679	>	n |= n >>> 4;
680	>	n |= n >>> 8;
681	>	n |= n >>> 16;
682	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
683	>	}
684
685	<	V replace(K key, int hash, V newValue) {
686	<	lock();
687	<	try {
688	<	HashEntry<K,V> e = getFirst(hash);
689	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
690	<	e = e.next;
691	<
692	<	V oldValue = null;
693	<	if (e != null) {
694	<	oldValue = e.value;
695	<	e.value = newValue;
685	>	/**
686	>	* Returns x's Class if it is of the form "class C implements
687	>	* Comparable<C>", else null.
688	>	*/
689	>	static Class<?> comparableClassFor(Object x) {
690	>	if (x instanceof Comparable) {
691	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
692	>	if ((c = x.getClass()) == String.class) // bypass checks
693	>	return c;
694	>	if ((ts = c.getGenericInterfaces()) != null) {
695	>	for (int i = 0; i < ts.length; ++i) {
696	>	if (((t = ts[i]) instanceof ParameterizedType) &&
697	>	((p = (ParameterizedType)t).getRawType() ==
698	>	Comparable.class) &&
699	>	(as = p.getActualTypeArguments()) != null &&
700	>	as.length == 1 && as[0] == c) // type arg is c
701	>	return c;
702		}
408	–	return oldValue;
409	–	} finally {
410	–	unlock();
703		}
704		}
705	+	return null;
706	+	}
707
708	+	/**
709	+	* Returns k.compareTo(x) if x matches kc (k's screened comparable
710	+	* class), else 0.
711	+	*/
712	+	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
713	+	static int compareComparables(Class<?> kc, Object k, Object x) {
714	+	return (x == null || x.getClass() != kc ? 0 :
715	+	((Comparable)k).compareTo(x));
716	+	}
717
718	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
416	<	lock();
417	<	try {
418	<	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	<	}
718	>	/* ---------------- Table element access -------------- */
719
720	<	void rehash() {
721	<	HashEntry<K,V>[] oldTable = table;
722	<	int oldCapacity = oldTable.length;
723	<	if (oldCapacity >= MAXIMUM_CAPACITY)
724	<	return;
720	>	/*
721	>	* Volatile access methods are used for table elements as well as
722	>	* elements of in-progress next table while resizing.  All uses of
723	>	* the tab arguments must be null checked by callers.  All callers
724	>	* also paranoically precheck that tab's length is not zero (or an
725	>	* equivalent check), thus ensuring that any index argument taking
726	>	* the form of a hash value anded with (length - 1) is a valid
727	>	* index.  Note that, to be correct wrt arbitrary concurrency
728	>	* errors by users, these checks must operate on local variables,
729	>	* which accounts for some odd-looking inline assignments below.
730	>	* Note that calls to setTabAt always occur within locked regions,
731	>	* and so in principle require only release ordering, not
732	>	* full volatile semantics, but are currently coded as volatile
733	>	* writes to be conservative.
734	>	*/
735	>
736	>	@SuppressWarnings("unchecked")
737	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
738	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
739	>	}
740
741	<	/*
742	<	* Reclassify nodes in each list to new Map.  Because we are
743	<	* using power-of-two expansion, the elements from each bin
744	<	* 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;
741	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
742	>	Node<K,V> c, Node<K,V> v) {
743	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
744	>	}
745
746	<	else {
747	<	// Reuse trailing consecutive sequence at same slot
748	<	HashEntry<K,V> lastRun = e;
485	<	int lastIdx = idx;
486	<	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;
746	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
747	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
748	>	}
749
750	<	// Clone all remaining nodes
498	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
499	<	int k = p.hash & sizeMask;
500	<	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	<	}
750	>	/* ---------------- Fields -------------- */
751
752	<	/**
753	<	* Remove; match on key only if value null, else match both.
754	<	*/
755	<	V remove(Object key, int hash, Object value) {
756	<	lock();
515	<	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	<	}
752	>	/**
753	>	* The array of bins. Lazily initialized upon first insertion.
754	>	* Size is always a power of two. Accessed directly by iterators.
755	>	*/
756	>	transient volatile Node<K,V>[] table;
757
758	<	void clear() {
759	<	if (count != 0) {
760	<	lock();
761	<	try {
551	<	HashEntry<K,V>[] tab = table;
552	<	for (int i = 0; i < tab.length ; i++)
553	<	tab[i] = null;
554	<	++modCount;
555	<	count = 0; // write-volatile
556	<	} finally {
557	<	unlock();
558	<	}
559	<	}
560	<	}
561	<	}
758	>	/**
759	>	* The next table to use; non-null only while resizing.
760	>	*/
761	>	private transient volatile Node<K,V>[] nextTable;
762
763	+	/**
764	+	* Base counter value, used mainly when there is no contention,
765	+	* but also as a fallback during table initialization
766	+	* races. Updated via CAS.
767	+	*/
768	+	private transient volatile long baseCount;
769
770	+	/**
771	+	* Table initialization and resizing control.  When negative, the
772	+	* table is being initialized or resized: -1 for initialization,
773	+	* else -(1 + the number of active resizing threads).  Otherwise,
774	+	* when table is null, holds the initial table size to use upon
775	+	* creation, or 0 for default. After initialization, holds the
776	+	* next element count value upon which to resize the table.
777	+	*/
778	+	private transient volatile int sizeCtl;
779
780	<	/* ---------------- Public operations -------------- */
780	>	/**
781	>	* The next table index (plus one) to split while resizing.
782	>	*/
783	>	private transient volatile int transferIndex;
784
785		/**
786	<	* 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.
786	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
787		*/
788	<	public ConcurrentHashMap(int initialCapacity,
584	<	float loadFactor, int concurrencyLevel) {
585	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
586	<	throw new IllegalArgumentException();
788	>	private transient volatile int cellsBusy;
789
790	<	if (concurrencyLevel > MAX_SEGMENTS)
791	<	concurrencyLevel = MAX_SEGMENTS;
790	>	/**
791	>	* Table of counter cells. When non-null, size is a power of 2.
792	>	*/
793	>	private transient volatile CounterCell[] counterCells;
794
795	<	// Find power-of-two sizes best matching arguments
796	<	int sshift = 0;
797	<	int ssize = 1;
798	<	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;
795	>	// views
796	>	private transient KeySetView<K,V> keySet;
797	>	private transient ValuesView<K,V> values;
798	>	private transient EntrySetView<K,V> entrySet;
799
800	<	for (int i = 0; i < this.segments.length; ++i)
801	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
613	<	}
800	>
801	>	/* ---------------- Public operations -------------- */
802
803		/**
804	<	* 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
804	>	* Creates a new, empty map with the default initial table size (16).
805		*/
806	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
630	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
806	>	public ConcurrentHashMap() {
807		}
808
809		/**
810	<	* Creates a new, empty map with the specified initial capacity,
811	<	* and with default load factor (0.75) and concurrencyLevel (16).
810	>	* Creates a new, empty map with an initial table size
811	>	* accommodating the specified number of elements without the need
812	>	* to dynamically resize.
813		*
814	<	* @param initialCapacity the initial capacity. The implementation
815	<	* performs internal sizing to accommodate this many elements.
814	>	* @param initialCapacity The implementation performs internal
815	>	* sizing to accommodate this many elements.
816		* @throws IllegalArgumentException if the initial capacity of
817	<	* elements is negative.
817	>	* elements is negative
818		*/
819		public ConcurrentHashMap(int initialCapacity) {
820	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
821	<	}
822	<
823	<	/**
824	<	* Creates a new, empty map with a default initial capacity (16),
825	<	* load factor (0.75) and concurrencyLevel (16).
649	<	*/
650	<	public ConcurrentHashMap() {
651	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
820	>	if (initialCapacity < 0)
821	>	throw new IllegalArgumentException();
822	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
823	>	MAXIMUM_CAPACITY :
824	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
825	>	this.sizeCtl = cap;
826		}
827
828		/**
829		* 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).
830		*
831		* @param m the map
832		*/
833		public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
834	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
664	<	DEFAULT_INITIAL_CAPACITY),
665	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
834	>	this.sizeCtl = DEFAULT_CAPACITY;
835		putAll(m);
836		}
837
838		/**
839	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
839	>	* Creates a new, empty map with an initial table size based on
840	>	* the given number of elements ({@code initialCapacity}) and
841	>	* initial table density ({@code loadFactor}).
842	>	*
843	>	* @param initialCapacity the initial capacity. The implementation
844	>	* performs internal sizing to accommodate this many elements,
845	>	* given the specified load factor.
846	>	* @param loadFactor the load factor (table density) for
847	>	* establishing the initial table size
848	>	* @throws IllegalArgumentException if the initial capacity of
849	>	* elements is negative or the load factor is nonpositive
850		*
851	<	* @return <tt>true</tt> if this map contains no key-value mappings
851	>	* @since 1.6
852		*/
853	<	public boolean isEmpty() {
854	<	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;
853	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
854	>	this(initialCapacity, loadFactor, 1);
855		}
856
857		/**
858	<	* Returns the number of key-value mappings in this map.  If the
859	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
860	<	* <tt>Integer.MAX_VALUE</tt>.
858	>	* Creates a new, empty map with an initial table size based on
859	>	* the given number of elements ({@code initialCapacity}), table
860	>	* density ({@code loadFactor}), and number of concurrently
861	>	* updating threads ({@code concurrencyLevel}).
862		*
863	<	* @return the number of key-value mappings in this map
863	>	* @param initialCapacity the initial capacity. The implementation
864	>	* performs internal sizing to accommodate this many elements,
865	>	* given the specified load factor.
866	>	* @param loadFactor the load factor (table density) for
867	>	* establishing the initial table size
868	>	* @param concurrencyLevel the estimated number of concurrently
869	>	* updating threads. The implementation may use this value as
870	>	* a sizing hint.
871	>	* @throws IllegalArgumentException if the initial capacity is
872	>	* negative or the load factor or concurrencyLevel are
873	>	* nonpositive
874	>	*/
875	>	public ConcurrentHashMap(int initialCapacity,
876	>	float loadFactor, int concurrencyLevel) {
877	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
878	>	throw new IllegalArgumentException();
879	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
880	>	initialCapacity = concurrencyLevel;   // as estimated threads
881	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
882	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
883	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
884	>	this.sizeCtl = cap;
885	>	}
886	>
887	>	// Original (since JDK1.2) Map methods
888	>
889	>	/**
890	>	* {@inheritDoc}
891		*/
892		public int size() {
893	<	final Segment<K,V>[] segments = this.segments;
894	<	long sum = 0;
895	<	long check = 0;
896	<	int[] mc = new int[segments.length];
897	<	// Try a few times to get accurate count. On failure due to
898	<	// continuous async changes in table, resort to locking.
899	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
900	<	check = 0;
901	<	sum = 0;
902	<	int mcsum = 0;
903	<	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;
893	>	long n = sumCount();
894	>	return ((n < 0L) ? 0 :
895	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
896	>	(int)n);
897	>	}
898	>
899	>	/**
900	>	* {@inheritDoc}
901	>	*/
902	>	public boolean isEmpty() {
903	>	return sumCount() <= 0L; // ignore transient negative values
904		}
905
906		/**
#	Line 764 | Line 915 | public class ConcurrentHashMap<K, V> ext
915		* @throws NullPointerException if the specified key is null
916		*/
917		public V get(Object key) {
918	<	int hash = hash(key.hashCode());
919	<	return segmentFor(hash).get(key, hash);
918	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
919	>	int h = spread(key.hashCode());
920	>	if ((tab = table) != null && (n = tab.length) > 0 &&
921	>	(e = tabAt(tab, (n - 1) & h)) != null) {
922	>	if ((eh = e.hash) == h) {
923	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
924	>	return e.val;
925	>	}
926	>	else if (eh < 0)
927	>	return (p = e.find(h, key)) != null ? p.val : null;
928	>	while ((e = e.next) != null) {
929	>	if (e.hash == h &&
930	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
931	>	return e.val;
932	>	}
933	>	}
934	>	return null;
935		}
936
937		/**
938		* Tests if the specified object is a key in this table.
939		*
940	<	* @param  key   possible key
941	<	* @return <tt>true</tt> if and only if the specified object
940	>	* @param  key possible key
941	>	* @return {@code true} if and only if the specified object
942		*         is a key in this table, as determined by the
943	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
943	>	*         {@code equals} method; {@code false} otherwise
944		* @throws NullPointerException if the specified key is null
945		*/
946		public boolean containsKey(Object key) {
947	<	int hash = hash(key.hashCode());
782	<	return segmentFor(hash).containsKey(key, hash);
947	>	return get(key) != null;
948		}
949
950		/**
951	<	* Returns <tt>true</tt> if this map maps one or more keys to the
952	<	* specified value. Note: This method requires a full internal
953	<	* traversal of the hash table, and so is much slower than
789	<	* method <tt>containsKey</tt>.
951	>	* Returns {@code true} if this map maps one or more keys to the
952	>	* specified value. Note: This method may require a full traversal
953	>	* of the map, and is much slower than method {@code containsKey}.
954		*
955		* @param value value whose presence in this map is to be tested
956	<	* @return <tt>true</tt> if this map maps one or more keys to the
956	>	* @return {@code true} if this map maps one or more keys to the
957		*         specified value
958		* @throws NullPointerException if the specified value is null
959		*/
960		public boolean containsValue(Object value) {
961		if (value == null)
962		throw new NullPointerException();
963	<
964	<	// See explanation of modCount use above
965	<
966	<	final Segment<K,V>[] segments = this.segments;
967	<	int[] mc = new int[segments.length];
968	<
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))
963	>	Node<K,V>[] t;
964	>	if ((t = table) != null) {
965	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
966	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
967	>	V v;
968	>	if ((v = p.val) == value || (v != null && value.equals(v)))
969		return true;
970		}
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;
971		}
972	<	// Resort to locking all segments
829	<	for (int i = 0; i < segments.length; ++i)
830	<	segments[i].lock();
831	<	boolean found = false;
832	<	try {
833	<	for (int i = 0; i < segments.length; ++i) {
834	<	if (segments[i].containsValue(value)) {
835	<	found = true;
836	<	break;
837	<	}
838	<	}
839	<	} finally {
840	<	for (int i = 0; i < segments.length; ++i)
841	<	segments[i].unlock();
842	<	}
843	<	return found;
844	<	}
845	<
846	<	/**
847	<	* Legacy method testing if some key maps into the specified value
848	<	* in this table.  This method is identical in functionality to
849	<	* {@link #containsValue}, and exists solely to ensure
850	<	* full compatibility with class {@link java.util.Hashtable},
851	<	* which supported this method prior to introduction of the
852	<	* Java Collections framework.
853	<
854	<	* @param  value a value to search for
855	<	* @return <tt>true</tt> if and only if some key maps to the
856	<	*         <tt>value</tt> argument in this table as
857	<	*         determined by the <tt>equals</tt> method;
858	<	*         <tt>false</tt> otherwise
859	<	* @throws NullPointerException if the specified value is null
860	<	*/
861	<	public boolean contains(Object value) {
862	<	return containsValue(value);
972	>	return false;
973		}
974
975		/**
976		* Maps the specified key to the specified value in this table.
977		* Neither the key nor the value can be null.
978		*
979	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
979	>	* <p>The value can be retrieved by calling the {@code get} method
980		* with a key that is equal to the original key.
981		*
982		* @param key key with which the specified value is to be associated
983		* @param value value to be associated with the specified key
984	<	* @return the previous value associated with <tt>key</tt>, or
985	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
984	>	* @return the previous value associated with {@code key}, or
985	>	*         {@code null} if there was no mapping for {@code key}
986		* @throws NullPointerException if the specified key or value is null
987		*/
988		public V put(K key, V value) {
989	<	if (value == null)
880	<	throw new NullPointerException();
881	<	int hash = hash(key.hashCode());
882	<	return segmentFor(hash).put(key, hash, value, false);
989	>	return putVal(key, value, false);
990		}
991
992	<	/**
993	<	* {@inheritDoc}
994	<	*
995	<	* @return the previous value associated with the specified key,
996	<	*         or <tt>null</tt> if there was no mapping for the key
997	<	* @throws NullPointerException if the specified key or value is null
998	<	*/
999	<	public V putIfAbsent(K key, V value) {
1000	<	if (value == null)
1001	<	throw new NullPointerException();
1002	<	int hash = hash(key.hashCode());
1003	<	return segmentFor(hash).put(key, hash, value, true);
992	>	/** Implementation for put and putIfAbsent */
993	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
994	>	if (key == null || value == null) throw new NullPointerException();
995	>	int hash = spread(key.hashCode());
996	>	int binCount = 0;
997	>	for (Node<K,V>[] tab = table;;) {
998	>	Node<K,V> f; int n, i, fh;
999	>	if (tab == null || (n = tab.length) == 0)
1000	>	tab = initTable();
1001	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1002	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
1003	>	break;                   // no lock when adding to empty bin
1004	>	}
1005	>	else if ((fh = f.hash) == MOVED)
1006	>	tab = helpTransfer(tab, f);
1007	>	else {
1008	>	V oldVal = null;
1009	>	synchronized (f) {
1010	>	if (tabAt(tab, i) == f) {
1011	>	if (fh >= 0) {
1012	>	binCount = 1;
1013	>	for (Node<K,V> e = f;; ++binCount) {
1014	>	K ek;
1015	>	if (e.hash == hash &&
1016	>	((ek = e.key) == key ||
1017	>	(ek != null && key.equals(ek)))) {
1018	>	oldVal = e.val;
1019	>	if (!onlyIfAbsent)
1020	>	e.val = value;
1021	>	break;
1022	>	}
1023	>	Node<K,V> pred = e;
1024	>	if ((e = e.next) == null) {
1025	>	pred.next = new Node<K,V>(hash, key, value);
1026	>	break;
1027	>	}
1028	>	}
1029	>	}
1030	>	else if (f instanceof TreeBin) {
1031	>	Node<K,V> p;
1032	>	binCount = 2;
1033	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1034	>	value)) != null) {
1035	>	oldVal = p.val;
1036	>	if (!onlyIfAbsent)
1037	>	p.val = value;
1038	>	}
1039	>	}
1040	>	else if (f instanceof ReservationNode)
1041	>	throw new IllegalStateException("Recursive update");
1042	>	}
1043	>	}
1044	>	if (binCount != 0) {
1045	>	if (binCount >= TREEIFY_THRESHOLD)
1046	>	treeifyBin(tab, i);
1047	>	if (oldVal != null)
1048	>	return oldVal;
1049	>	break;
1050	>	}
1051	>	}
1052	>	}
1053	>	addCount(1L, binCount);
1054	>	return null;
1055		}
1056
1057		/**
#	Line 904 | Line 1062 | public class ConcurrentHashMap<K, V> ext
1062		* @param m mappings to be stored in this map
1063		*/
1064		public void putAll(Map<? extends K, ? extends V> m) {
1065	+	tryPresize(m.size());
1066		for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1067	<	put(e.getKey(), e.getValue());
1067	>	putVal(e.getKey(), e.getValue(), false);
1068		}
1069
1070		/**
#	Line 913 | Line 1072 | public class ConcurrentHashMap<K, V> ext
1072		* This method does nothing if the key is not in the map.
1073		*
1074		* @param  key the key that needs to be removed
1075	<	* @return the previous value associated with <tt>key</tt>, or
1076	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1075	>	* @return the previous value associated with {@code key}, or
1076	>	*         {@code null} if there was no mapping for {@code key}
1077		* @throws NullPointerException if the specified key is null
1078		*/
1079		public V remove(Object key) {
1080	<	int hash = hash(key.hashCode());
1081	<	return segmentFor(hash).remove(key, hash, null);
1080	>	return replaceNode(key, null, null);
1081	>	}
1082	>
1083	>	/**
1084	>	* Implementation for the four public remove/replace methods:
1085	>	* Replaces node value with v, conditional upon match of cv if
1086	>	* non-null.  If resulting value is null, delete.
1087	>	*/
1088	>	final V replaceNode(Object key, V value, Object cv) {
1089	>	int hash = spread(key.hashCode());
1090	>	for (Node<K,V>[] tab = table;;) {
1091	>	Node<K,V> f; int n, i, fh;
1092	>	if (tab == null || (n = tab.length) == 0 ||
1093	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1094	>	break;
1095	>	else if ((fh = f.hash) == MOVED)
1096	>	tab = helpTransfer(tab, f);
1097	>	else {
1098	>	V oldVal = null;
1099	>	boolean validated = false;
1100	>	synchronized (f) {
1101	>	if (tabAt(tab, i) == f) {
1102	>	if (fh >= 0) {
1103	>	validated = true;
1104	>	for (Node<K,V> e = f, pred = null;;) {
1105	>	K ek;
1106	>	if (e.hash == hash &&
1107	>	((ek = e.key) == key ||
1108	>	(ek != null && key.equals(ek)))) {
1109	>	V ev = e.val;
1110	>	if (cv == null || cv == ev ||
1111	>	(ev != null && cv.equals(ev))) {
1112	>	oldVal = ev;
1113	>	if (value != null)
1114	>	e.val = value;
1115	>	else if (pred != null)
1116	>	pred.next = e.next;
1117	>	else
1118	>	setTabAt(tab, i, e.next);
1119	>	}
1120	>	break;
1121	>	}
1122	>	pred = e;
1123	>	if ((e = e.next) == null)
1124	>	break;
1125	>	}
1126	>	}
1127	>	else if (f instanceof TreeBin) {
1128	>	validated = true;
1129	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1130	>	TreeNode<K,V> r, p;
1131	>	if ((r = t.root) != null &&
1132	>	(p = r.findTreeNode(hash, key, null)) != null) {
1133	>	V pv = p.val;
1134	>	if (cv == null || cv == pv ||
1135	>	(pv != null && cv.equals(pv))) {
1136	>	oldVal = pv;
1137	>	if (value != null)
1138	>	p.val = value;
1139	>	else if (t.removeTreeNode(p))
1140	>	setTabAt(tab, i, untreeify(t.first));
1141	>	}
1142	>	}
1143	>	}
1144	>	else if (f instanceof ReservationNode)
1145	>	throw new IllegalStateException("Recursive update");
1146	>	}
1147	>	}
1148	>	if (validated) {
1149	>	if (oldVal != null) {
1150	>	if (value == null)
1151	>	addCount(-1L, -1);
1152	>	return oldVal;
1153	>	}
1154	>	break;
1155	>	}
1156	>	}
1157	>	}
1158	>	return null;
1159	>	}
1160	>
1161	>	/**
1162	>	* Removes all of the mappings from this map.
1163	>	*/
1164	>	public void clear() {
1165	>	long delta = 0L; // negative number of deletions
1166	>	int i = 0;
1167	>	Node<K,V>[] tab = table;
1168	>	while (tab != null && i < tab.length) {
1169	>	int fh;
1170	>	Node<K,V> f = tabAt(tab, i);
1171	>	if (f == null)
1172	>	++i;
1173	>	else if ((fh = f.hash) == MOVED) {
1174	>	tab = helpTransfer(tab, f);
1175	>	i = 0; // restart
1176	>	}
1177	>	else {
1178	>	synchronized (f) {
1179	>	if (tabAt(tab, i) == f) {
1180	>	Node<K,V> p = (fh >= 0 ? f :
1181	>	(f instanceof TreeBin) ?
1182	>	((TreeBin<K,V>)f).first : null);
1183	>	while (p != null) {
1184	>	--delta;
1185	>	p = p.next;
1186	>	}
1187	>	setTabAt(tab, i++, null);
1188	>	}
1189	>	}
1190	>	}
1191	>	}
1192	>	if (delta != 0L)
1193	>	addCount(delta, -1);
1194	>	}
1195	>
1196	>	/**
1197	>	* Returns a {@link Set} view of the keys contained in this map.
1198	>	* The set is backed by the map, so changes to the map are
1199	>	* reflected in the set, and vice-versa. The set supports element
1200	>	* removal, which removes the corresponding mapping from this map,
1201	>	* via the {@code Iterator.remove}, {@code Set.remove},
1202	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1203	>	* operations.  It does not support the {@code add} or
1204	>	* {@code addAll} operations.
1205	>	*
1206	>	* <p>The view's iterators and spliterators are
1207	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1208	>	*
1209	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1210	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1211	>	*
1212	>	* @return the set view
1213	>	*/
1214	>	public KeySetView<K,V> keySet() {
1215	>	KeySetView<K,V> ks;
1216	>	if ((ks = keySet) != null) return ks;
1217	>	return keySet = new KeySetView<K,V>(this, null);
1218	>	}
1219	>
1220	>	/**
1221	>	* Returns a {@link Collection} view of the values contained in this map.
1222	>	* The collection is backed by the map, so changes to the map are
1223	>	* reflected in the collection, and vice-versa.  The collection
1224	>	* supports element removal, which removes the corresponding
1225	>	* mapping from this map, via the {@code Iterator.remove},
1226	>	* {@code Collection.remove}, {@code removeAll},
1227	>	* {@code retainAll}, and {@code clear} operations.  It does not
1228	>	* support the {@code add} or {@code addAll} operations.
1229	>	*
1230	>	* <p>The view's iterators and spliterators are
1231	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1232	>	*
1233	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1234	>	* and {@link Spliterator#NONNULL}.
1235	>	*
1236	>	* @return the collection view
1237	>	*/
1238	>	public Collection<V> values() {
1239	>	ValuesView<K,V> vs;
1240	>	if ((vs = values) != null) return vs;
1241	>	return values = new ValuesView<K,V>(this);
1242	>	}
1243	>
1244	>	/**
1245	>	* Returns a {@link Set} view of the mappings contained in this map.
1246	>	* The set is backed by the map, so changes to the map are
1247	>	* reflected in the set, and vice-versa.  The set supports element
1248	>	* removal, which removes the corresponding mapping from the map,
1249	>	* via the {@code Iterator.remove}, {@code Set.remove},
1250	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1251	>	* operations.
1252	>	*
1253	>	* <p>The view's iterators and spliterators are
1254	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1255	>	*
1256	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1257	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1258	>	*
1259	>	* @return the set view
1260	>	*/
1261	>	public Set<Map.Entry<K,V>> entrySet() {
1262	>	EntrySetView<K,V> es;
1263	>	if ((es = entrySet) != null) return es;
1264	>	return entrySet = new EntrySetView<K,V>(this);
1265	>	}
1266	>
1267	>	/**
1268	>	* Returns the hash code value for this {@link Map}, i.e.,
1269	>	* the sum of, for each key-value pair in the map,
1270	>	* {@code key.hashCode() ^ value.hashCode()}.
1271	>	*
1272	>	* @return the hash code value for this map
1273	>	*/
1274	>	public int hashCode() {
1275	>	int h = 0;
1276	>	Node<K,V>[] t;
1277	>	if ((t = table) != null) {
1278	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1279	>	for (Node<K,V> p; (p = it.advance()) != null; )
1280	>	h += p.key.hashCode() ^ p.val.hashCode();
1281	>	}
1282	>	return h;
1283	>	}
1284	>
1285	>	/**
1286	>	* Returns a string representation of this map.  The string
1287	>	* representation consists of a list of key-value mappings (in no
1288	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1289	>	* mappings are separated by the characters {@code ", "} (comma
1290	>	* and space).  Each key-value mapping is rendered as the key
1291	>	* followed by an equals sign ("{@code =}") followed by the
1292	>	* associated value.
1293	>	*
1294	>	* @return a string representation of this map
1295	>	*/
1296	>	public String toString() {
1297	>	Node<K,V>[] t;
1298	>	int f = (t = table) == null ? 0 : t.length;
1299	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1300	>	StringBuilder sb = new StringBuilder();
1301	>	sb.append('{');
1302	>	Node<K,V> p;
1303	>	if ((p = it.advance()) != null) {
1304	>	for (;;) {
1305	>	K k = p.key;
1306	>	V v = p.val;
1307	>	sb.append(k == this ? "(this Map)" : k);
1308	>	sb.append('=');
1309	>	sb.append(v == this ? "(this Map)" : v);
1310	>	if ((p = it.advance()) == null)
1311	>	break;
1312	>	sb.append(',').append(' ');
1313	>	}
1314	>	}
1315	>	return sb.append('}').toString();
1316	>	}
1317	>
1318	>	/**
1319	>	* Compares the specified object with this map for equality.
1320	>	* Returns {@code true} if the given object is a map with the same
1321	>	* mappings as this map.  This operation may return misleading
1322	>	* results if either map is concurrently modified during execution
1323	>	* of this method.
1324	>	*
1325	>	* @param o object to be compared for equality with this map
1326	>	* @return {@code true} if the specified object is equal to this map
1327	>	*/
1328	>	public boolean equals(Object o) {
1329	>	if (o != this) {
1330	>	if (!(o instanceof Map))
1331	>	return false;
1332	>	Map<?,?> m = (Map<?,?>) o;
1333	>	Node<K,V>[] t;
1334	>	int f = (t = table) == null ? 0 : t.length;
1335	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1336	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1337	>	V val = p.val;
1338	>	Object v = m.get(p.key);
1339	>	if (v == null || (v != val && !v.equals(val)))
1340	>	return false;
1341	>	}
1342	>	for (Map.Entry<?,?> e : m.entrySet()) {
1343	>	Object mk, mv, v;
1344	>	if ((mk = e.getKey()) == null ||
1345	>	(mv = e.getValue()) == null ||
1346	>	(v = get(mk)) == null ||
1347	>	(mv != v && !mv.equals(v)))
1348	>	return false;
1349	>	}
1350	>	}
1351	>	return true;
1352	>	}
1353	>
1354	>	/**
1355	>	* Stripped-down version of helper class used in previous version,
1356	>	* declared for the sake of serialization compatibility.
1357	>	*/
1358	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1359	>	private static final long serialVersionUID = 2249069246763182397L;
1360	>	final float loadFactor;
1361	>	Segment(float lf) { this.loadFactor = lf; }
1362	>	}
1363	>
1364	>	/**
1365	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1366	>	* stream (i.e., serializes it).
1367	>	* @param s the stream
1368	>	* @throws java.io.IOException if an I/O error occurs
1369	>	* @serialData
1370	>	* the serialized fields, followed by the key (Object) and value
1371	>	* (Object) for each key-value mapping, followed by a null pair.
1372	>	* The key-value mappings are emitted in no particular order.
1373	>	*/
1374	>	private void writeObject(java.io.ObjectOutputStream s)
1375	>	throws java.io.IOException {
1376	>	// For serialization compatibility
1377	>	// Emulate segment calculation from previous version of this class
1378	>	int sshift = 0;
1379	>	int ssize = 1;
1380	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1381	>	++sshift;
1382	>	ssize <<= 1;
1383	>	}
1384	>	int segmentShift = 32 - sshift;
1385	>	int segmentMask = ssize - 1;
1386	>	@SuppressWarnings("unchecked")
1387	>	Segment<K,V>[] segments = (Segment<K,V>[])
1388	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1389	>	for (int i = 0; i < segments.length; ++i)
1390	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1391	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1392	>	streamFields.put("segments", segments);
1393	>	streamFields.put("segmentShift", segmentShift);
1394	>	streamFields.put("segmentMask", segmentMask);
1395	>	s.writeFields();
1396	>
1397	>	Node<K,V>[] t;
1398	>	if ((t = table) != null) {
1399	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1400	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1401	>	s.writeObject(p.key);
1402	>	s.writeObject(p.val);
1403	>	}
1404	>	}
1405	>	s.writeObject(null);
1406	>	s.writeObject(null);
1407	>	}
1408	>
1409	>	/**
1410	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1411	>	* @param s the stream
1412	>	* @throws ClassNotFoundException if the class of a serialized object
1413	>	*         could not be found
1414	>	* @throws java.io.IOException if an I/O error occurs
1415	>	*/
1416	>	private void readObject(java.io.ObjectInputStream s)
1417	>	throws java.io.IOException, ClassNotFoundException {
1418	>	/*
1419	>	* To improve performance in typical cases, we create nodes
1420	>	* while reading, then place in table once size is known.
1421	>	* However, we must also validate uniqueness and deal with
1422	>	* overpopulated bins while doing so, which requires
1423	>	* specialized versions of putVal mechanics.
1424	>	*/
1425	>	sizeCtl = -1; // force exclusion for table construction
1426	>	s.defaultReadObject();
1427	>	long size = 0L;
1428	>	Node<K,V> p = null;
1429	>	for (;;) {
1430	>	@SuppressWarnings("unchecked")
1431	>	K k = (K) s.readObject();
1432	>	@SuppressWarnings("unchecked")
1433	>	V v = (V) s.readObject();
1434	>	if (k != null && v != null) {
1435	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1436	>	++size;
1437	>	}
1438	>	else
1439	>	break;
1440	>	}
1441	>	if (size == 0L)
1442	>	sizeCtl = 0;
1443	>	else {
1444	>	int n;
1445	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1446	>	n = MAXIMUM_CAPACITY;
1447	>	else {
1448	>	int sz = (int)size;
1449	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1450	>	}
1451	>	@SuppressWarnings("unchecked")
1452	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1453	>	int mask = n - 1;
1454	>	long added = 0L;
1455	>	while (p != null) {
1456	>	boolean insertAtFront;
1457	>	Node<K,V> next = p.next, first;
1458	>	int h = p.hash, j = h & mask;
1459	>	if ((first = tabAt(tab, j)) == null)
1460	>	insertAtFront = true;
1461	>	else {
1462	>	K k = p.key;
1463	>	if (first.hash < 0) {
1464	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1465	>	if (t.putTreeVal(h, k, p.val) == null)
1466	>	++added;
1467	>	insertAtFront = false;
1468	>	}
1469	>	else {
1470	>	int binCount = 0;
1471	>	insertAtFront = true;
1472	>	Node<K,V> q; K qk;
1473	>	for (q = first; q != null; q = q.next) {
1474	>	if (q.hash == h &&
1475	>	((qk = q.key) == k ||
1476	>	(qk != null && k.equals(qk)))) {
1477	>	insertAtFront = false;
1478	>	break;
1479	>	}
1480	>	++binCount;
1481	>	}
1482	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1483	>	insertAtFront = false;
1484	>	++added;
1485	>	p.next = first;
1486	>	TreeNode<K,V> hd = null, tl = null;
1487	>	for (q = p; q != null; q = q.next) {
1488	>	TreeNode<K,V> t = new TreeNode<K,V>
1489	>	(q.hash, q.key, q.val, null, null);
1490	>	if ((t.prev = tl) == null)
1491	>	hd = t;
1492	>	else
1493	>	tl.next = t;
1494	>	tl = t;
1495	>	}
1496	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1497	>	}
1498	>	}
1499	>	}
1500	>	if (insertAtFront) {
1501	>	++added;
1502	>	p.next = first;
1503	>	setTabAt(tab, j, p);
1504	>	}
1505	>	p = next;
1506	>	}
1507	>	table = tab;
1508	>	sizeCtl = n - (n >>> 2);
1509	>	baseCount = added;
1510	>	}
1511	>	}
1512	>
1513	>	// ConcurrentMap methods
1514	>
1515	>	/**
1516	>	* {@inheritDoc}
1517	>	*
1518	>	* @return the previous value associated with the specified key,
1519	>	*         or {@code null} if there was no mapping for the key
1520	>	* @throws NullPointerException if the specified key or value is null
1521	>	*/
1522	>	public V putIfAbsent(K key, V value) {
1523	>	return putVal(key, value, true);
1524		}
1525
1526		/**
#	Line 928 | Line 1529 | public class ConcurrentHashMap<K, V> ext
1529		* @throws NullPointerException if the specified key is null
1530		*/
1531		public boolean remove(Object key, Object value) {
1532	<	int hash = hash(key.hashCode());
1533	<	if (value == null)
1534	<	return false;
934	<	return segmentFor(hash).remove(key, hash, value) != null;
1532	>	if (key == null)
1533	>	throw new NullPointerException();
1534	>	return value != null && replaceNode(key, null, value) != null;
1535		}
1536
1537		/**
#	Line 940 | Line 1540 | public class ConcurrentHashMap<K, V> ext
1540		* @throws NullPointerException if any of the arguments are null
1541		*/
1542		public boolean replace(K key, V oldValue, V newValue) {
1543	<	if (oldValue == null || newValue == null)
1543	>	if (key == null || oldValue == null || newValue == null)
1544		throw new NullPointerException();
1545	<	int hash = hash(key.hashCode());
946	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
1545	>	return replaceNode(key, newValue, oldValue) != null;
1546		}
1547
1548		/**
1549		* {@inheritDoc}
1550		*
1551		* @return the previous value associated with the specified key,
1552	<	*         or <tt>null</tt> if there was no mapping for the key
1552	>	*         or {@code null} if there was no mapping for the key
1553		* @throws NullPointerException if the specified key or value is null
1554		*/
1555		public V replace(K key, V value) {
1556	<	if (value == null)
1556	>	if (key == null || value == null)
1557		throw new NullPointerException();
1558	<	int hash = hash(key.hashCode());
960	<	return segmentFor(hash).replace(key, hash, value);
1558	>	return replaceNode(key, value, null);
1559		}
1560
1561	+	// Overrides of JDK8+ Map extension method defaults
1562	+
1563		/**
1564	<	* Removes all of the mappings from this map.
1564	>	* Returns the value to which the specified key is mapped, or the
1565	>	* given default value if this map contains no mapping for the
1566	>	* key.
1567	>	*
1568	>	* @param key the key whose associated value is to be returned
1569	>	* @param defaultValue the value to return if this map contains
1570	>	* no mapping for the given key
1571	>	* @return the mapping for the key, if present; else the default value
1572	>	* @throws NullPointerException if the specified key is null
1573		*/
1574	<	public void clear() {
1575	<	for (int i = 0; i < segments.length; ++i)
1576	<	segments[i].clear();
1574	>	public V getOrDefault(Object key, V defaultValue) {
1575	>	V v;
1576	>	return (v = get(key)) == null ? defaultValue : v;
1577	>	}
1578	>
1579	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1580	>	if (action == null) throw new NullPointerException();
1581	>	Node<K,V>[] t;
1582	>	if ((t = table) != null) {
1583	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1584	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1585	>	action.accept(p.key, p.val);
1586	>	}
1587	>	}
1588	>	}
1589	>
1590	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1591	>	if (function == null) throw new NullPointerException();
1592	>	Node<K,V>[] t;
1593	>	if ((t = table) != null) {
1594	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1595	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1596	>	V oldValue = p.val;
1597	>	for (K key = p.key;;) {
1598	>	V newValue = function.apply(key, oldValue);
1599	>	if (newValue == null)
1600	>	throw new NullPointerException();
1601	>	if (replaceNode(key, newValue, oldValue) != null ||
1602	>	(oldValue = get(key)) == null)
1603	>	break;
1604	>	}
1605	>	}
1606	>	}
1607		}
1608
1609		/**
1610	<	* Returns a {@link Set} view of the keys contained in this map.
1611	<	* The set is backed by the map, so changes to the map are
1612	<	* reflected in the set, and vice-versa.  The set supports element
1613	<	* removal, which removes the corresponding mapping from this map,
1614	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1615	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1616	<	* operations.  It does not support the <tt>add</tt> or
1617	<	* <tt>addAll</tt> operations.
1618	<	*
1619	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1620	<	* that will never throw {@link ConcurrentModificationException},
1621	<	* and guarantees to traverse elements as they existed upon
1622	<	* construction of the iterator, and may (but is not guaranteed to)
1623	<	* reflect any modifications subsequent to construction.
1624	<	*/
1625	<	public Set<K> keySet() {
1626	<	Set<K> ks = keySet;
989	<	return (ks != null) ? ks : (keySet = new KeySet());
1610	>	* Helper method for EntrySetView.removeIf.
1611	>	*/
1612	>	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1613	>	if (function == null) throw new NullPointerException();
1614	>	Node<K,V>[] t;
1615	>	boolean removed = false;
1616	>	if ((t = table) != null) {
1617	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1618	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1619	>	K k = p.key;
1620	>	V v = p.val;
1621	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1622	>	if (function.test(e) && replaceNode(k, null, v) != null)
1623	>	removed = true;
1624	>	}
1625	>	}
1626	>	return removed;
1627		}
1628
1629		/**
1630	<	* Returns a {@link Collection} view of the values contained in this map.
994	<	* The collection is backed by the map, so changes to the map are
995	<	* reflected in the collection, and vice-versa.  The collection
996	<	* supports element removal, which removes the corresponding
997	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
998	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
999	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1000	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1001	<	*
1002	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1003	<	* that will never throw {@link ConcurrentModificationException},
1004	<	* and guarantees to traverse elements as they existed upon
1005	<	* construction of the iterator, and may (but is not guaranteed to)
1006	<	* reflect any modifications subsequent to construction.
1630	>	* Helper method for ValuesView.removeIf.
1631		*/
1632	<	public Collection<V> values() {
1633	<	Collection<V> vs = values;
1634	<	return (vs != null) ? vs : (values = new Values());
1632	>	boolean removeValueIf(Predicate<? super V> function) {
1633	>	if (function == null) throw new NullPointerException();
1634	>	Node<K,V>[] t;
1635	>	boolean removed = false;
1636	>	if ((t = table) != null) {
1637	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1638	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1639	>	K k = p.key;
1640	>	V v = p.val;
1641	>	if (function.test(v) && replaceNode(k, null, v) != null)
1642	>	removed = true;
1643	>	}
1644	>	}
1645	>	return removed;
1646		}
1647
1648		/**
1649	<	* Returns a {@link Set} view of the mappings contained in this map.
1650	<	* The set is backed by the map, so changes to the map are
1651	<	* reflected in the set, and vice-versa.  The set supports element
1652	<	* removal, which removes the corresponding mapping from the map,
1653	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1654	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1655	<	* operations.  It does not support the <tt>add</tt> or
1656	<	* <tt>addAll</tt> operations.
1657	<	*
1658	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1659	<	* that will never throw {@link ConcurrentModificationException},
1660	<	* and guarantees to traverse elements as they existed upon
1661	<	* construction of the iterator, and may (but is not guaranteed to)
1662	<	* reflect any modifications subsequent to construction.
1649	>	* If the specified key is not already associated with a value,
1650	>	* attempts to compute its value using the given mapping function
1651	>	* and enters it into this map unless {@code null}.  The entire
1652	>	* method invocation is performed atomically, so the function is
1653	>	* applied at most once per key.  Some attempted update operations
1654	>	* on this map by other threads may be blocked while computation
1655	>	* is in progress, so the computation should be short and simple,
1656	>	* and must not attempt to update any other mappings of this map.
1657	>	*
1658	>	* @param key key with which the specified value is to be associated
1659	>	* @param mappingFunction the function to compute a value
1660	>	* @return the current (existing or computed) value associated with
1661	>	*         the specified key, or null if the computed value is null
1662	>	* @throws NullPointerException if the specified key or mappingFunction
1663	>	*         is null
1664	>	* @throws IllegalStateException if the computation detectably
1665	>	*         attempts a recursive update to this map that would
1666	>	*         otherwise never complete
1667	>	* @throws RuntimeException or Error if the mappingFunction does so,
1668	>	*         in which case the mapping is left unestablished
1669		*/
1670	<	public Set<Map.Entry<K,V>> entrySet() {
1671	<	Set<Map.Entry<K,V>> es = entrySet;
1672	<	return (es != null) ? es : (entrySet = new EntrySet());
1670	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1671	>	if (key == null || mappingFunction == null)
1672	>	throw new NullPointerException();
1673	>	int h = spread(key.hashCode());
1674	>	V val = null;
1675	>	int binCount = 0;
1676	>	for (Node<K,V>[] tab = table;;) {
1677	>	Node<K,V> f; int n, i, fh;
1678	>	if (tab == null || (n = tab.length) == 0)
1679	>	tab = initTable();
1680	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1681	>	Node<K,V> r = new ReservationNode<K,V>();
1682	>	synchronized (r) {
1683	>	if (casTabAt(tab, i, null, r)) {
1684	>	binCount = 1;
1685	>	Node<K,V> node = null;
1686	>	try {
1687	>	if ((val = mappingFunction.apply(key)) != null)
1688	>	node = new Node<K,V>(h, key, val);
1689	>	} finally {
1690	>	setTabAt(tab, i, node);
1691	>	}
1692	>	}
1693	>	}
1694	>	if (binCount != 0)
1695	>	break;
1696	>	}
1697	>	else if ((fh = f.hash) == MOVED)
1698	>	tab = helpTransfer(tab, f);
1699	>	else {
1700	>	boolean added = false;
1701	>	synchronized (f) {
1702	>	if (tabAt(tab, i) == f) {
1703	>	if (fh >= 0) {
1704	>	binCount = 1;
1705	>	for (Node<K,V> e = f;; ++binCount) {
1706	>	K ek;
1707	>	if (e.hash == h &&
1708	>	((ek = e.key) == key ||
1709	>	(ek != null && key.equals(ek)))) {
1710	>	val = e.val;
1711	>	break;
1712	>	}
1713	>	Node<K,V> pred = e;
1714	>	if ((e = e.next) == null) {
1715	>	if ((val = mappingFunction.apply(key)) != null) {
1716	>	if (pred.next != null)
1717	>	throw new IllegalStateException("Recursive update");
1718	>	added = true;
1719	>	pred.next = new Node<K,V>(h, key, val);
1720	>	}
1721	>	break;
1722	>	}
1723	>	}
1724	>	}
1725	>	else if (f instanceof TreeBin) {
1726	>	binCount = 2;
1727	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1728	>	TreeNode<K,V> r, p;
1729	>	if ((r = t.root) != null &&
1730	>	(p = r.findTreeNode(h, key, null)) != null)
1731	>	val = p.val;
1732	>	else if ((val = mappingFunction.apply(key)) != null) {
1733	>	added = true;
1734	>	t.putTreeVal(h, key, val);
1735	>	}
1736	>	}
1737	>	else if (f instanceof ReservationNode)
1738	>	throw new IllegalStateException("Recursive update");
1739	>	}
1740	>	}
1741	>	if (binCount != 0) {
1742	>	if (binCount >= TREEIFY_THRESHOLD)
1743	>	treeifyBin(tab, i);
1744	>	if (!added)
1745	>	return val;
1746	>	break;
1747	>	}
1748	>	}
1749	>	}
1750	>	if (val != null)
1751	>	addCount(1L, binCount);
1752	>	return val;
1753	>	}
1754	>
1755	>	/**
1756	>	* If the value for the specified key is present, attempts to
1757	>	* compute a new mapping given the key and its current mapped
1758	>	* value.  The entire method invocation is performed atomically.
1759	>	* Some attempted update operations on this map by other threads
1760	>	* may be blocked while computation is in progress, so the
1761	>	* computation should be short and simple, and must not attempt to
1762	>	* update any other mappings of this map.
1763	>	*
1764	>	* @param key key with which a value may be associated
1765	>	* @param remappingFunction the function to compute a value
1766	>	* @return the new value associated with the specified key, or null if none
1767	>	* @throws NullPointerException if the specified key or remappingFunction
1768	>	*         is null
1769	>	* @throws IllegalStateException if the computation detectably
1770	>	*         attempts a recursive update to this map that would
1771	>	*         otherwise never complete
1772	>	* @throws RuntimeException or Error if the remappingFunction does so,
1773	>	*         in which case the mapping is unchanged
1774	>	*/
1775	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1776	>	if (key == null || remappingFunction == null)
1777	>	throw new NullPointerException();
1778	>	int h = spread(key.hashCode());
1779	>	V val = null;
1780	>	int delta = 0;
1781	>	int binCount = 0;
1782	>	for (Node<K,V>[] tab = table;;) {
1783	>	Node<K,V> f; int n, i, fh;
1784	>	if (tab == null || (n = tab.length) == 0)
1785	>	tab = initTable();
1786	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1787	>	break;
1788	>	else if ((fh = f.hash) == MOVED)
1789	>	tab = helpTransfer(tab, f);
1790	>	else {
1791	>	synchronized (f) {
1792	>	if (tabAt(tab, i) == f) {
1793	>	if (fh >= 0) {
1794	>	binCount = 1;
1795	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1796	>	K ek;
1797	>	if (e.hash == h &&
1798	>	((ek = e.key) == key ||
1799	>	(ek != null && key.equals(ek)))) {
1800	>	val = remappingFunction.apply(key, e.val);
1801	>	if (val != null)
1802	>	e.val = val;
1803	>	else {
1804	>	delta = -1;
1805	>	Node<K,V> en = e.next;
1806	>	if (pred != null)
1807	>	pred.next = en;
1808	>	else
1809	>	setTabAt(tab, i, en);
1810	>	}
1811	>	break;
1812	>	}
1813	>	pred = e;
1814	>	if ((e = e.next) == null)
1815	>	break;
1816	>	}
1817	>	}
1818	>	else if (f instanceof TreeBin) {
1819	>	binCount = 2;
1820	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1821	>	TreeNode<K,V> r, p;
1822	>	if ((r = t.root) != null &&
1823	>	(p = r.findTreeNode(h, key, null)) != null) {
1824	>	val = remappingFunction.apply(key, p.val);
1825	>	if (val != null)
1826	>	p.val = val;
1827	>	else {
1828	>	delta = -1;
1829	>	if (t.removeTreeNode(p))
1830	>	setTabAt(tab, i, untreeify(t.first));
1831	>	}
1832	>	}
1833	>	}
1834	>	else if (f instanceof ReservationNode)
1835	>	throw new IllegalStateException("Recursive update");
1836	>	}
1837	>	}
1838	>	if (binCount != 0)
1839	>	break;
1840	>	}
1841	>	}
1842	>	if (delta != 0)
1843	>	addCount((long)delta, binCount);
1844	>	return val;
1845	>	}
1846	>
1847	>	/**
1848	>	* Attempts to compute a mapping for the specified key and its
1849	>	* current mapped value (or {@code null} if there is no current
1850	>	* mapping). The entire method invocation is performed atomically.
1851	>	* Some attempted update operations on this map by other threads
1852	>	* may be blocked while computation is in progress, so the
1853	>	* computation should be short and simple, and must not attempt to
1854	>	* update any other mappings of this Map.
1855	>	*
1856	>	* @param key key with which the specified value is to be associated
1857	>	* @param remappingFunction the function to compute a value
1858	>	* @return the new value associated with the specified key, or null if none
1859	>	* @throws NullPointerException if the specified key or remappingFunction
1860	>	*         is null
1861	>	* @throws IllegalStateException if the computation detectably
1862	>	*         attempts a recursive update to this map that would
1863	>	*         otherwise never complete
1864	>	* @throws RuntimeException or Error if the remappingFunction does so,
1865	>	*         in which case the mapping is unchanged
1866	>	*/
1867	>	public V compute(K key,
1868	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1869	>	if (key == null || remappingFunction == null)
1870	>	throw new NullPointerException();
1871	>	int h = spread(key.hashCode());
1872	>	V val = null;
1873	>	int delta = 0;
1874	>	int binCount = 0;
1875	>	for (Node<K,V>[] tab = table;;) {
1876	>	Node<K,V> f; int n, i, fh;
1877	>	if (tab == null || (n = tab.length) == 0)
1878	>	tab = initTable();
1879	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1880	>	Node<K,V> r = new ReservationNode<K,V>();
1881	>	synchronized (r) {
1882	>	if (casTabAt(tab, i, null, r)) {
1883	>	binCount = 1;
1884	>	Node<K,V> node = null;
1885	>	try {
1886	>	if ((val = remappingFunction.apply(key, null)) != null) {
1887	>	delta = 1;
1888	>	node = new Node<K,V>(h, key, val);
1889	>	}
1890	>	} finally {
1891	>	setTabAt(tab, i, node);
1892	>	}
1893	>	}
1894	>	}
1895	>	if (binCount != 0)
1896	>	break;
1897	>	}
1898	>	else if ((fh = f.hash) == MOVED)
1899	>	tab = helpTransfer(tab, f);
1900	>	else {
1901	>	synchronized (f) {
1902	>	if (tabAt(tab, i) == f) {
1903	>	if (fh >= 0) {
1904	>	binCount = 1;
1905	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1906	>	K ek;
1907	>	if (e.hash == h &&
1908	>	((ek = e.key) == key ||
1909	>	(ek != null && key.equals(ek)))) {
1910	>	val = remappingFunction.apply(key, e.val);
1911	>	if (val != null)
1912	>	e.val = val;
1913	>	else {
1914	>	delta = -1;
1915	>	Node<K,V> en = e.next;
1916	>	if (pred != null)
1917	>	pred.next = en;
1918	>	else
1919	>	setTabAt(tab, i, en);
1920	>	}
1921	>	break;
1922	>	}
1923	>	pred = e;
1924	>	if ((e = e.next) == null) {
1925	>	val = remappingFunction.apply(key, null);
1926	>	if (val != null) {
1927	>	if (pred.next != null)
1928	>	throw new IllegalStateException("Recursive update");
1929	>	delta = 1;
1930	>	pred.next = new Node<K,V>(h, key, val);
1931	>	}
1932	>	break;
1933	>	}
1934	>	}
1935	>	}
1936	>	else if (f instanceof TreeBin) {
1937	>	binCount = 1;
1938	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1939	>	TreeNode<K,V> r, p;
1940	>	if ((r = t.root) != null)
1941	>	p = r.findTreeNode(h, key, null);
1942	>	else
1943	>	p = null;
1944	>	V pv = (p == null) ? null : p.val;
1945	>	val = remappingFunction.apply(key, pv);
1946	>	if (val != null) {
1947	>	if (p != null)
1948	>	p.val = val;
1949	>	else {
1950	>	delta = 1;
1951	>	t.putTreeVal(h, key, val);
1952	>	}
1953	>	}
1954	>	else if (p != null) {
1955	>	delta = -1;
1956	>	if (t.removeTreeNode(p))
1957	>	setTabAt(tab, i, untreeify(t.first));
1958	>	}
1959	>	}
1960	>	else if (f instanceof ReservationNode)
1961	>	throw new IllegalStateException("Recursive update");
1962	>	}
1963	>	}
1964	>	if (binCount != 0) {
1965	>	if (binCount >= TREEIFY_THRESHOLD)
1966	>	treeifyBin(tab, i);
1967	>	break;
1968	>	}
1969	>	}
1970	>	}
1971	>	if (delta != 0)
1972	>	addCount((long)delta, binCount);
1973	>	return val;
1974	>	}
1975	>
1976	>	/**
1977	>	* If the specified key is not already associated with a
1978	>	* (non-null) value, associates it with the given value.
1979	>	* Otherwise, replaces the value with the results of the given
1980	>	* remapping function, or removes if {@code null}. The entire
1981	>	* method invocation is performed atomically.  Some attempted
1982	>	* update operations on this map by other threads may be blocked
1983	>	* while computation is in progress, so the computation should be
1984	>	* short and simple, and must not attempt to update any other
1985	>	* mappings of this Map.
1986	>	*
1987	>	* @param key key with which the specified value is to be associated
1988	>	* @param value the value to use if absent
1989	>	* @param remappingFunction the function to recompute a value if present
1990	>	* @return the new value associated with the specified key, or null if none
1991	>	* @throws NullPointerException if the specified key or the
1992	>	*         remappingFunction is null
1993	>	* @throws RuntimeException or Error if the remappingFunction does so,
1994	>	*         in which case the mapping is unchanged
1995	>	*/
1996	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1997	>	if (key == null || value == null || remappingFunction == null)
1998	>	throw new NullPointerException();
1999	>	int h = spread(key.hashCode());
2000	>	V val = null;
2001	>	int delta = 0;
2002	>	int binCount = 0;
2003	>	for (Node<K,V>[] tab = table;;) {
2004	>	Node<K,V> f; int n, i, fh;
2005	>	if (tab == null || (n = tab.length) == 0)
2006	>	tab = initTable();
2007	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2008	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2009	>	delta = 1;
2010	>	val = value;
2011	>	break;
2012	>	}
2013	>	}
2014	>	else if ((fh = f.hash) == MOVED)
2015	>	tab = helpTransfer(tab, f);
2016	>	else {
2017	>	synchronized (f) {
2018	>	if (tabAt(tab, i) == f) {
2019	>	if (fh >= 0) {
2020	>	binCount = 1;
2021	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
2022	>	K ek;
2023	>	if (e.hash == h &&
2024	>	((ek = e.key) == key ||
2025	>	(ek != null && key.equals(ek)))) {
2026	>	val = remappingFunction.apply(e.val, value);
2027	>	if (val != null)
2028	>	e.val = val;
2029	>	else {
2030	>	delta = -1;
2031	>	Node<K,V> en = e.next;
2032	>	if (pred != null)
2033	>	pred.next = en;
2034	>	else
2035	>	setTabAt(tab, i, en);
2036	>	}
2037	>	break;
2038	>	}
2039	>	pred = e;
2040	>	if ((e = e.next) == null) {
2041	>	delta = 1;
2042	>	val = value;
2043	>	pred.next = new Node<K,V>(h, key, val);
2044	>	break;
2045	>	}
2046	>	}
2047	>	}
2048	>	else if (f instanceof TreeBin) {
2049	>	binCount = 2;
2050	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2051	>	TreeNode<K,V> r = t.root;
2052	>	TreeNode<K,V> p = (r == null) ? null :
2053	>	r.findTreeNode(h, key, null);
2054	>	val = (p == null) ? value :
2055	>	remappingFunction.apply(p.val, value);
2056	>	if (val != null) {
2057	>	if (p != null)
2058	>	p.val = val;
2059	>	else {
2060	>	delta = 1;
2061	>	t.putTreeVal(h, key, val);
2062	>	}
2063	>	}
2064	>	else if (p != null) {
2065	>	delta = -1;
2066	>	if (t.removeTreeNode(p))
2067	>	setTabAt(tab, i, untreeify(t.first));
2068	>	}
2069	>	}
2070	>	else if (f instanceof ReservationNode)
2071	>	throw new IllegalStateException("Recursive update");
2072	>	}
2073	>	}
2074	>	if (binCount != 0) {
2075	>	if (binCount >= TREEIFY_THRESHOLD)
2076	>	treeifyBin(tab, i);
2077	>	break;
2078	>	}
2079	>	}
2080	>	}
2081	>	if (delta != 0)
2082	>	addCount((long)delta, binCount);
2083	>	return val;
2084	>	}
2085	>
2086	>	// Hashtable legacy methods
2087	>
2088	>	/**
2089	>	* Tests if some key maps into the specified value in this table.
2090	>	*
2091	>	* <p>Note that this method is identical in functionality to
2092	>	* {@link #containsValue(Object)}, and exists solely to ensure
2093	>	* full compatibility with class {@link java.util.Hashtable},
2094	>	* which supported this method prior to introduction of the
2095	>	* Java Collections Framework.
2096	>	*
2097	>	* @param  value a value to search for
2098	>	* @return {@code true} if and only if some key maps to the
2099	>	*         {@code value} argument in this table as
2100	>	*         determined by the {@code equals} method;
2101	>	*         {@code false} otherwise
2102	>	* @throws NullPointerException if the specified value is null
2103	>	*/
2104	>	public boolean contains(Object value) {
2105	>	return containsValue(value);
2106		}
2107
2108		/**
2109		* Returns an enumeration of the keys in this table.
2110		*
2111		* @return an enumeration of the keys in this table
2112	<	* @see #keySet
2112	>	* @see #keySet()
2113		*/
2114		public Enumeration<K> keys() {
2115	<	return new KeyIterator();
2115	>	Node<K,V>[] t;
2116	>	int f = (t = table) == null ? 0 : t.length;
2117	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2118		}
2119
2120		/**
2121		* Returns an enumeration of the values in this table.
2122		*
2123		* @return an enumeration of the values in this table
2124	<	* @see #values
2124	>	* @see #values()
2125		*/
2126		public Enumeration<V> elements() {
2127	<	return new ValueIterator();
2127	>	Node<K,V>[] t;
2128	>	int f = (t = table) == null ? 0 : t.length;
2129	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2130		}
2131
2132	<	/* ---------------- Iterator Support -------------- */
2132	>	// ConcurrentHashMap-only methods
2133
2134	<	abstract class HashIterator {
2135	<	int nextSegmentIndex;
2136	<	int nextTableIndex;
2137	<	HashEntry<K,V>[] currentTable;
2138	<	HashEntry<K, V> nextEntry;
2139	<	HashEntry<K, V> lastReturned;
2134	>	/**
2135	>	* Returns the number of mappings. This method should be used
2136	>	* instead of {@link #size} because a ConcurrentHashMap may
2137	>	* contain more mappings than can be represented as an int. The
2138	>	* value returned is an estimate; the actual count may differ if
2139	>	* there are concurrent insertions or removals.
2140	>	*
2141	>	* @return the number of mappings
2142	>	* @since 1.8
2143	>	*/
2144	>	public long mappingCount() {
2145	>	long n = sumCount();
2146	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2147	>	}
2148
2149	<	HashIterator() {
2150	<	nextSegmentIndex = segments.length - 1;
2151	<	nextTableIndex = -1;
2152	<	advance();
2149	>	/**
2150	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2151	>	* from the given type to {@code Boolean.TRUE}.
2152	>	*
2153	>	* @param <K> the element type of the returned set
2154	>	* @return the new set
2155	>	* @since 1.8
2156	>	*/
2157	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2158	>	return new KeySetView<K,Boolean>
2159	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2160	>	}
2161	>
2162	>	/**
2163	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2164	>	* from the given type to {@code Boolean.TRUE}.
2165	>	*
2166	>	* @param initialCapacity The implementation performs internal
2167	>	* sizing to accommodate this many elements.
2168	>	* @param <K> the element type of the returned set
2169	>	* @return the new set
2170	>	* @throws IllegalArgumentException if the initial capacity of
2171	>	* elements is negative
2172	>	* @since 1.8
2173	>	*/
2174	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2175	>	return new KeySetView<K,Boolean>
2176	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2177	>	}
2178	>
2179	>	/**
2180	>	* Returns a {@link Set} view of the keys in this map, using the
2181	>	* given common mapped value for any additions (i.e., {@link
2182	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2183	>	* This is of course only appropriate if it is acceptable to use
2184	>	* the same value for all additions from this view.
2185	>	*
2186	>	* @param mappedValue the mapped value to use for any additions
2187	>	* @return the set view
2188	>	* @throws NullPointerException if the mappedValue is null
2189	>	*/
2190	>	public KeySetView<K,V> keySet(V mappedValue) {
2191	>	if (mappedValue == null)
2192	>	throw new NullPointerException();
2193	>	return new KeySetView<K,V>(this, mappedValue);
2194	>	}
2195	>
2196	>	/* ---------------- Special Nodes -------------- */
2197	>
2198	>	/**
2199	>	* A node inserted at head of bins during transfer operations.
2200	>	*/
2201	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2202	>	final Node<K,V>[] nextTable;
2203	>	ForwardingNode(Node<K,V>[] tab) {
2204	>	super(MOVED, null, null);
2205	>	this.nextTable = tab;
2206	>	}
2207	>
2208	>	Node<K,V> find(int h, Object k) {
2209	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2210	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2211	>	Node<K,V> e; int n;
2212	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2213	>	(e = tabAt(tab, (n - 1) & h)) == null)
2214	>	return null;
2215	>	for (;;) {
2216	>	int eh; K ek;
2217	>	if ((eh = e.hash) == h &&
2218	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2219	>	return e;
2220	>	if (eh < 0) {
2221	>	if (e instanceof ForwardingNode) {
2222	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2223	>	continue outer;
2224	>	}
2225	>	else
2226	>	return e.find(h, k);
2227	>	}
2228	>	if ((e = e.next) == null)
2229	>	return null;
2230	>	}
2231	>	}
2232		}
2233	+	}
2234	+
2235	+	/**
2236	+	* A place-holder node used in computeIfAbsent and compute.
2237	+	*/
2238	+	static final class ReservationNode<K,V> extends Node<K,V> {
2239	+	ReservationNode() {
2240	+	super(RESERVED, null, null);
2241	+	}
2242	+
2243	+	Node<K,V> find(int h, Object k) {
2244	+	return null;
2245	+	}
2246	+	}
2247	+
2248	+	/* ---------------- Table Initialization and Resizing -------------- */
2249	+
2250	+	/**
2251	+	* Returns the stamp bits for resizing a table of size n.
2252	+	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2253	+	*/
2254	+	static final int resizeStamp(int n) {
2255	+	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2256	+	}
2257
2258	<	public boolean hasMoreElements() { return hasNext(); }
2258	>	/**
2259	>	* Initializes table, using the size recorded in sizeCtl.
2260	>	*/
2261	>	private final Node<K,V>[] initTable() {
2262	>	Node<K,V>[] tab; int sc;
2263	>	while ((tab = table) == null || tab.length == 0) {
2264	>	if ((sc = sizeCtl) < 0)
2265	>	Thread.yield(); // lost initialization race; just spin
2266	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2267	>	try {
2268	>	if ((tab = table) == null || tab.length == 0) {
2269	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2270	>	@SuppressWarnings("unchecked")
2271	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2272	>	table = tab = nt;
2273	>	sc = n - (n >>> 2);
2274	>	}
2275	>	} finally {
2276	>	sizeCtl = sc;
2277	>	}
2278	>	break;
2279	>	}
2280	>	}
2281	>	return tab;
2282	>	}
2283
2284	<	final void advance() {
2285	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
2284	>	/**
2285	>	* Adds to count, and if table is too small and not already
2286	>	* resizing, initiates transfer. If already resizing, helps
2287	>	* perform transfer if work is available.  Rechecks occupancy
2288	>	* after a transfer to see if another resize is already needed
2289	>	* because resizings are lagging additions.
2290	>	*
2291	>	* @param x the count to add
2292	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2293	>	*/
2294	>	private final void addCount(long x, int check) {
2295	>	CounterCell[] as; long b, s;
2296	>	if ((as = counterCells) != null ||
2297	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2298	>	CounterCell a; long v; int m;
2299	>	boolean uncontended = true;
2300	>	if (as == null || (m = as.length - 1) < 0 ||
2301	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2302	>	!(uncontended =
2303	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2304	>	fullAddCount(x, uncontended);
2305		return;
2306	+	}
2307	+	if (check <= 1)
2308	+	return;
2309	+	s = sumCount();
2310	+	}
2311	+	if (check >= 0) {
2312	+	Node<K,V>[] tab, nt; int n, sc;
2313	+	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2314	+	(n = tab.length) < MAXIMUM_CAPACITY) {
2315	+	int rs = resizeStamp(n);
2316	+	if (sc < 0) {
2317	+	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2318	+	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2319	+	transferIndex <= 0)
2320	+	break;
2321	+	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2322	+	transfer(tab, nt);
2323	+	}
2324	+	else if (U.compareAndSwapInt(this, SIZECTL, sc,
2325	+	(rs << RESIZE_STAMP_SHIFT) + 2))
2326	+	transfer(tab, null);
2327	+	s = sumCount();
2328	+	}
2329	+	}
2330	+	}
2331
2332	<	while (nextTableIndex >= 0) {
2333	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
2332	>	/**
2333	>	* Helps transfer if a resize is in progress.
2334	>	*/
2335	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2336	>	Node<K,V>[] nextTab; int sc;
2337	>	if (tab != null && (f instanceof ForwardingNode) &&
2338	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2339	>	int rs = resizeStamp(tab.length);
2340	>	while (nextTab == nextTable && table == tab &&
2341	>	(sc = sizeCtl) < 0) {
2342	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2343	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2344	>	break;
2345	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2346	>	transfer(tab, nextTab);
2347	>	break;
2348	>	}
2349	>	}
2350	>	return nextTab;
2351	>	}
2352	>	return table;
2353	>	}
2354	>
2355	>	/**
2356	>	* Tries to presize table to accommodate the given number of elements.
2357	>	*
2358	>	* @param size number of elements (doesn't need to be perfectly accurate)
2359	>	*/
2360	>	private final void tryPresize(int size) {
2361	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2362	>	tableSizeFor(size + (size >>> 1) + 1);
2363	>	int sc;
2364	>	while ((sc = sizeCtl) >= 0) {
2365	>	Node<K,V>[] tab = table; int n;
2366	>	if (tab == null || (n = tab.length) == 0) {
2367	>	n = (sc > c) ? sc : c;
2368	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2369	>	try {
2370	>	if (table == tab) {
2371	>	@SuppressWarnings("unchecked")
2372	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2373	>	table = nt;
2374	>	sc = n - (n >>> 2);
2375	>	}
2376	>	} finally {
2377	>	sizeCtl = sc;
2378	>	}
2379	>	}
2380	>	}
2381	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2382	>	break;
2383	>	else if (tab == table) {
2384	>	int rs = resizeStamp(n);
2385	>	if (U.compareAndSwapInt(this, SIZECTL, sc,
2386	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2387	>	transfer(tab, null);
2388	>	}
2389	>	}
2390	>	}
2391	>
2392	>	/**
2393	>	* Moves and/or copies the nodes in each bin to new table. See
2394	>	* above for explanation.
2395	>	*/
2396	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2397	>	int n = tab.length, stride;
2398	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2399	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2400	>	if (nextTab == null) {            // initiating
2401	>	try {
2402	>	@SuppressWarnings("unchecked")
2403	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2404	>	nextTab = nt;
2405	>	} catch (Throwable ex) {      // try to cope with OOME
2406	>	sizeCtl = Integer.MAX_VALUE;
2407	>	return;
2408	>	}
2409	>	nextTable = nextTab;
2410	>	transferIndex = n;
2411	>	}
2412	>	int nextn = nextTab.length;
2413	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2414	>	boolean advance = true;
2415	>	boolean finishing = false; // to ensure sweep before committing nextTab
2416	>	for (int i = 0, bound = 0;;) {
2417	>	Node<K,V> f; int fh;
2418	>	while (advance) {
2419	>	int nextIndex, nextBound;
2420	>	if (--i >= bound || finishing)
2421	>	advance = false;
2422	>	else if ((nextIndex = transferIndex) <= 0) {
2423	>	i = -1;
2424	>	advance = false;
2425	>	}
2426	>	else if (U.compareAndSwapInt
2427	>	(this, TRANSFERINDEX, nextIndex,
2428	>	nextBound = (nextIndex > stride ?
2429	>	nextIndex - stride : 0))) {
2430	>	bound = nextBound;
2431	>	i = nextIndex - 1;
2432	>	advance = false;
2433	>	}
2434	>	}
2435	>	if (i < 0 || i >= n || i + n >= nextn) {
2436	>	int sc;
2437	>	if (finishing) {
2438	>	nextTable = null;
2439	>	table = nextTab;
2440	>	sizeCtl = (n << 1) - (n >>> 1);
2441		return;
2442	+	}
2443	+	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2444	+	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2445	+	return;
2446	+	finishing = advance = true;
2447	+	i = n; // recheck before commit
2448	+	}
2449	+	}
2450	+	else if ((f = tabAt(tab, i)) == null)
2451	+	advance = casTabAt(tab, i, null, fwd);
2452	+	else if ((fh = f.hash) == MOVED)
2453	+	advance = true; // already processed
2454	+	else {
2455	+	synchronized (f) {
2456	+	if (tabAt(tab, i) == f) {
2457	+	Node<K,V> ln, hn;
2458	+	if (fh >= 0) {
2459	+	int runBit = fh & n;
2460	+	Node<K,V> lastRun = f;
2461	+	for (Node<K,V> p = f.next; p != null; p = p.next) {
2462	+	int b = p.hash & n;
2463	+	if (b != runBit) {
2464	+	runBit = b;
2465	+	lastRun = p;
2466	+	}
2467	+	}
2468	+	if (runBit == 0) {
2469	+	ln = lastRun;
2470	+	hn = null;
2471	+	}
2472	+	else {
2473	+	hn = lastRun;
2474	+	ln = null;
2475	+	}
2476	+	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2477	+	int ph = p.hash; K pk = p.key; V pv = p.val;
2478	+	if ((ph & n) == 0)
2479	+	ln = new Node<K,V>(ph, pk, pv, ln);
2480	+	else
2481	+	hn = new Node<K,V>(ph, pk, pv, hn);
2482	+	}
2483	+	setTabAt(nextTab, i, ln);
2484	+	setTabAt(nextTab, i + n, hn);
2485	+	setTabAt(tab, i, fwd);
2486	+	advance = true;
2487	+	}
2488	+	else if (f instanceof TreeBin) {
2489	+	TreeBin<K,V> t = (TreeBin<K,V>)f;
2490	+	TreeNode<K,V> lo = null, loTail = null;
2491	+	TreeNode<K,V> hi = null, hiTail = null;
2492	+	int lc = 0, hc = 0;
2493	+	for (Node<K,V> e = t.first; e != null; e = e.next) {
2494	+	int h = e.hash;
2495	+	TreeNode<K,V> p = new TreeNode<K,V>
2496	+	(h, e.key, e.val, null, null);
2497	+	if ((h & n) == 0) {
2498	+	if ((p.prev = loTail) == null)
2499	+	lo = p;
2500	+	else
2501	+	loTail.next = p;
2502	+	loTail = p;
2503	+	++lc;
2504	+	}
2505	+	else {
2506	+	if ((p.prev = hiTail) == null)
2507	+	hi = p;
2508	+	else
2509	+	hiTail.next = p;
2510	+	hiTail = p;
2511	+	++hc;
2512	+	}
2513	+	}
2514	+	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2515	+	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2516	+	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2517	+	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2518	+	setTabAt(nextTab, i, ln);
2519	+	setTabAt(nextTab, i + n, hn);
2520	+	setTabAt(tab, i, fwd);
2521	+	advance = true;
2522	+	}
2523	+	}
2524	+	}
2525	+	}
2526	+	}
2527	+	}
2528	+
2529	+	/* ---------------- Counter support -------------- */
2530	+
2531	+	/**
2532	+	* A padded cell for distributing counts.  Adapted from LongAdder
2533	+	* and Striped64.  See their internal docs for explanation.
2534	+	*/
2535	+	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2536	+	volatile long value;
2537	+	CounterCell(long x) { value = x; }
2538	+	}
2539	+
2540	+	final long sumCount() {
2541	+	CounterCell[] as = counterCells; CounterCell a;
2542	+	long sum = baseCount;
2543	+	if (as != null) {
2544	+	for (int i = 0; i < as.length; ++i) {
2545	+	if ((a = as[i]) != null)
2546	+	sum += a.value;
2547		}
2548	+	}
2549	+	return sum;
2550	+	}
2551
2552	<	while (nextSegmentIndex >= 0) {
2553	<	Segment<K,V> seg = segments[nextSegmentIndex--];
2554	<	if (seg.count != 0) {
2555	<	currentTable = seg.table;
2556	<	for (int j = currentTable.length - 1; j >= 0; --j) {
2557	<	if ( (nextEntry = currentTable[j]) != null) {
2558	<	nextTableIndex = j - 1;
2559	<	return;
2552	>	// See LongAdder version for explanation
2553	>	private final void fullAddCount(long x, boolean wasUncontended) {
2554	>	int h;
2555	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2556	>	ThreadLocalRandom.localInit();      // force initialization
2557	>	h = ThreadLocalRandom.getProbe();
2558	>	wasUncontended = true;
2559	>	}
2560	>	boolean collide = false;                // True if last slot nonempty
2561	>	for (;;) {
2562	>	CounterCell[] as; CounterCell a; int n; long v;
2563	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2564	>	if ((a = as[(n - 1) & h]) == null) {
2565	>	if (cellsBusy == 0) {            // Try to attach new Cell
2566	>	CounterCell r = new CounterCell(x); // Optimistic create
2567	>	if (cellsBusy == 0 &&
2568	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2569	>	boolean created = false;
2570	>	try {               // Recheck under lock
2571	>	CounterCell[] rs; int m, j;
2572	>	if ((rs = counterCells) != null &&
2573	>	(m = rs.length) > 0 &&
2574	>	rs[j = (m - 1) & h] == null) {
2575	>	rs[j] = r;
2576	>	created = true;
2577	>	}
2578	>	} finally {
2579	>	cellsBusy = 0;
2580	>	}
2581	>	if (created)
2582	>	break;
2583	>	continue;           // Slot is now non-empty
2584		}
2585		}
2586	+	collide = false;
2587		}
2588	+	else if (!wasUncontended)       // CAS already known to fail
2589	+	wasUncontended = true;      // Continue after rehash
2590	+	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2591	+	break;
2592	+	else if (counterCells != as || n >= NCPU)
2593	+	collide = false;            // At max size or stale
2594	+	else if (!collide)
2595	+	collide = true;
2596	+	else if (cellsBusy == 0 &&
2597	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2598	+	try {
2599	+	if (counterCells == as) {// Expand table unless stale
2600	+	CounterCell[] rs = new CounterCell[n << 1];
2601	+	for (int i = 0; i < n; ++i)
2602	+	rs[i] = as[i];
2603	+	counterCells = rs;
2604	+	}
2605	+	} finally {
2606	+	cellsBusy = 0;
2607	+	}
2608	+	collide = false;
2609	+	continue;                   // Retry with expanded table
2610	+	}
2611	+	h = ThreadLocalRandom.advanceProbe(h);
2612		}
2613	+	else if (cellsBusy == 0 && counterCells == as &&
2614	+	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2615	+	boolean init = false;
2616	+	try {                           // Initialize table
2617	+	if (counterCells == as) {
2618	+	CounterCell[] rs = new CounterCell[2];
2619	+	rs[h & 1] = new CounterCell(x);
2620	+	counterCells = rs;
2621	+	init = true;
2622	+	}
2623	+	} finally {
2624	+	cellsBusy = 0;
2625	+	}
2626	+	if (init)
2627	+	break;
2628	+	}
2629	+	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2630	+	break;                          // Fall back on using base
2631		}
2632	+	}
2633
2634	<	public boolean hasNext() { return nextEntry != null; }
2634	>	/* ---------------- Conversion from/to TreeBins -------------- */
2635
2636	<	HashEntry<K,V> nextEntry() {
2637	<	if (nextEntry == null)
2638	<	throw new NoSuchElementException();
2639	<	lastReturned = nextEntry;
2636	>	/**
2637	>	* Replaces all linked nodes in bin at given index unless table is
2638	>	* too small, in which case resizes instead.
2639	>	*/
2640	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2641	>	Node<K,V> b; int n;
2642	>	if (tab != null) {
2643	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2644	>	tryPresize(n << 1);
2645	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2646	>	synchronized (b) {
2647	>	if (tabAt(tab, index) == b) {
2648	>	TreeNode<K,V> hd = null, tl = null;
2649	>	for (Node<K,V> e = b; e != null; e = e.next) {
2650	>	TreeNode<K,V> p =
2651	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2652	>	null, null);
2653	>	if ((p.prev = tl) == null)
2654	>	hd = p;
2655	>	else
2656	>	tl.next = p;
2657	>	tl = p;
2658	>	}
2659	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2660	>	}
2661	>	}
2662	>	}
2663	>	}
2664	>	}
2665	>
2666	>	/**
2667	>	* Returns a list of non-TreeNodes replacing those in given list.
2668	>	*/
2669	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2670	>	Node<K,V> hd = null, tl = null;
2671	>	for (Node<K,V> q = b; q != null; q = q.next) {
2672	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2673	>	if (tl == null)
2674	>	hd = p;
2675	>	else
2676	>	tl.next = p;
2677	>	tl = p;
2678	>	}
2679	>	return hd;
2680	>	}
2681	>
2682	>	/* ---------------- TreeNodes -------------- */
2683	>
2684	>	/**
2685	>	* Nodes for use in TreeBins.
2686	>	*/
2687	>	static final class TreeNode<K,V> extends Node<K,V> {
2688	>	TreeNode<K,V> parent;  // red-black tree links
2689	>	TreeNode<K,V> left;
2690	>	TreeNode<K,V> right;
2691	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2692	>	boolean red;
2693	>
2694	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2695	>	TreeNode<K,V> parent) {
2696	>	super(hash, key, val, next);
2697	>	this.parent = parent;
2698	>	}
2699	>
2700	>	Node<K,V> find(int h, Object k) {
2701	>	return findTreeNode(h, k, null);
2702	>	}
2703	>
2704	>	/**
2705	>	* Returns the TreeNode (or null if not found) for the given key
2706	>	* starting at given root.
2707	>	*/
2708	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2709	>	if (k != null) {
2710	>	TreeNode<K,V> p = this;
2711	>	do {
2712	>	int ph, dir; K pk; TreeNode<K,V> q;
2713	>	TreeNode<K,V> pl = p.left, pr = p.right;
2714	>	if ((ph = p.hash) > h)
2715	>	p = pl;
2716	>	else if (ph < h)
2717	>	p = pr;
2718	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2719	>	return p;
2720	>	else if (pl == null)
2721	>	p = pr;
2722	>	else if (pr == null)
2723	>	p = pl;
2724	>	else if ((kc != null ||
2725	>	(kc = comparableClassFor(k)) != null) &&
2726	>	(dir = compareComparables(kc, k, pk)) != 0)
2727	>	p = (dir < 0) ? pl : pr;
2728	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2729	>	return q;
2730	>	else
2731	>	p = pl;
2732	>	} while (p != null);
2733	>	}
2734	>	return null;
2735	>	}
2736	>	}
2737	>
2738	>	/* ---------------- TreeBins -------------- */
2739	>
2740	>	/**
2741	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2742	>	* keys or values, but instead point to list of TreeNodes and
2743	>	* their root. They also maintain a parasitic read-write lock
2744	>	* forcing writers (who hold bin lock) to wait for readers (who do
2745	>	* not) to complete before tree restructuring operations.
2746	>	*/
2747	>	static final class TreeBin<K,V> extends Node<K,V> {
2748	>	TreeNode<K,V> root;
2749	>	volatile TreeNode<K,V> first;
2750	>	volatile Thread waiter;
2751	>	volatile int lockState;
2752	>	// values for lockState
2753	>	static final int WRITER = 1; // set while holding write lock
2754	>	static final int WAITER = 2; // set when waiting for write lock
2755	>	static final int READER = 4; // increment value for setting read lock
2756	>
2757	>	/**
2758	>	* Tie-breaking utility for ordering insertions when equal
2759	>	* hashCodes and non-comparable. We don't require a total
2760	>	* order, just a consistent insertion rule to maintain
2761	>	* equivalence across rebalancings. Tie-breaking further than
2762	>	* necessary simplifies testing a bit.
2763	>	*/
2764	>	static int tieBreakOrder(Object a, Object b) {
2765	>	int d;
2766	>	if (a == null || b == null ||
2767	>	(d = a.getClass().getName().
2768	>	compareTo(b.getClass().getName())) == 0)
2769	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2770	>	-1 : 1);
2771	>	return d;
2772	>	}
2773	>
2774	>	/**
2775	>	* Creates bin with initial set of nodes headed by b.
2776	>	*/
2777	>	TreeBin(TreeNode<K,V> b) {
2778	>	super(TREEBIN, null, null);
2779	>	this.first = b;
2780	>	TreeNode<K,V> r = null;
2781	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2782	>	next = (TreeNode<K,V>)x.next;
2783	>	x.left = x.right = null;
2784	>	if (r == null) {
2785	>	x.parent = null;
2786	>	x.red = false;
2787	>	r = x;
2788	>	}
2789	>	else {
2790	>	K k = x.key;
2791	>	int h = x.hash;
2792	>	Class<?> kc = null;
2793	>	for (TreeNode<K,V> p = r;;) {
2794	>	int dir, ph;
2795	>	K pk = p.key;
2796	>	if ((ph = p.hash) > h)
2797	>	dir = -1;
2798	>	else if (ph < h)
2799	>	dir = 1;
2800	>	else if ((kc == null &&
2801	>	(kc = comparableClassFor(k)) == null) ||
2802	>	(dir = compareComparables(kc, k, pk)) == 0)
2803	>	dir = tieBreakOrder(k, pk);
2804	>	TreeNode<K,V> xp = p;
2805	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2806	>	x.parent = xp;
2807	>	if (dir <= 0)
2808	>	xp.left = x;
2809	>	else
2810	>	xp.right = x;
2811	>	r = balanceInsertion(r, x);
2812	>	break;
2813	>	}
2814	>	}
2815	>	}
2816	>	}
2817	>	this.root = r;
2818	>	assert checkInvariants(root);
2819	>	}
2820	>
2821	>	/**
2822	>	* Acquires write lock for tree restructuring.
2823	>	*/
2824	>	private final void lockRoot() {
2825	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2826	>	contendedLock(); // offload to separate method
2827	>	}
2828	>
2829	>	/**
2830	>	* Releases write lock for tree restructuring.
2831	>	*/
2832	>	private final void unlockRoot() {
2833	>	lockState = 0;
2834	>	}
2835	>
2836	>	/**
2837	>	* Possibly blocks awaiting root lock.
2838	>	*/
2839	>	private final void contendedLock() {
2840	>	boolean waiting = false;
2841	>	for (int s;;) {
2842	>	if (((s = lockState) & ~WAITER) == 0) {
2843	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2844	>	if (waiting)
2845	>	waiter = null;
2846	>	return;
2847	>	}
2848	>	}
2849	>	else if ((s & WAITER) == 0) {
2850	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2851	>	waiting = true;
2852	>	waiter = Thread.currentThread();
2853	>	}
2854	>	}
2855	>	else if (waiting)
2856	>	LockSupport.park(this);
2857	>	}
2858	>	}
2859	>
2860	>	/**
2861	>	* Returns matching node or null if none. Tries to search
2862	>	* using tree comparisons from root, but continues linear
2863	>	* search when lock not available.
2864	>	*/
2865	>	final Node<K,V> find(int h, Object k) {
2866	>	if (k != null) {
2867	>	for (Node<K,V> e = first; e != null; ) {
2868	>	int s; K ek;
2869	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2870	>	if (e.hash == h &&
2871	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2872	>	return e;
2873	>	e = e.next;
2874	>	}
2875	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2876	>	s + READER)) {
2877	>	TreeNode<K,V> r, p;
2878	>	try {
2879	>	p = ((r = root) == null ? null :
2880	>	r.findTreeNode(h, k, null));
2881	>	} finally {
2882	>	Thread w;
2883	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2884	>	(READER|WAITER) && (w = waiter) != null)
2885	>	LockSupport.unpark(w);
2886	>	}
2887	>	return p;
2888	>	}
2889	>	}
2890	>	}
2891	>	return null;
2892	>	}
2893	>
2894	>	/**
2895	>	* Finds or adds a node.
2896	>	* @return null if added
2897	>	*/
2898	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2899	>	Class<?> kc = null;
2900	>	boolean searched = false;
2901	>	for (TreeNode<K,V> p = root;;) {
2902	>	int dir, ph; K pk;
2903	>	if (p == null) {
2904	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2905	>	break;
2906	>	}
2907	>	else if ((ph = p.hash) > h)
2908	>	dir = -1;
2909	>	else if (ph < h)
2910	>	dir = 1;
2911	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2912	>	return p;
2913	>	else if ((kc == null &&
2914	>	(kc = comparableClassFor(k)) == null) ||
2915	>	(dir = compareComparables(kc, k, pk)) == 0) {
2916	>	if (!searched) {
2917	>	TreeNode<K,V> q, ch;
2918	>	searched = true;
2919	>	if (((ch = p.left) != null &&
2920	>	(q = ch.findTreeNode(h, k, kc)) != null) ||
2921	>	((ch = p.right) != null &&
2922	>	(q = ch.findTreeNode(h, k, kc)) != null))
2923	>	return q;
2924	>	}
2925	>	dir = tieBreakOrder(k, pk);
2926	>	}
2927	>
2928	>	TreeNode<K,V> xp = p;
2929	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2930	>	TreeNode<K,V> x, f = first;
2931	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2932	>	if (f != null)
2933	>	f.prev = x;
2934	>	if (dir <= 0)
2935	>	xp.left = x;
2936	>	else
2937	>	xp.right = x;
2938	>	if (!xp.red)
2939	>	x.red = true;
2940	>	else {
2941	>	lockRoot();
2942	>	try {
2943	>	root = balanceInsertion(root, x);
2944	>	} finally {
2945	>	unlockRoot();
2946	>	}
2947	>	}
2948	>	break;
2949	>	}
2950	>	}
2951	>	assert checkInvariants(root);
2952	>	return null;
2953	>	}
2954	>
2955	>	/**
2956	>	* Removes the given node, that must be present before this
2957	>	* call.  This is messier than typical red-black deletion code
2958	>	* because we cannot swap the contents of an interior node
2959	>	* with a leaf successor that is pinned by "next" pointers
2960	>	* that are accessible independently of lock. So instead we
2961	>	* swap the tree linkages.
2962	>	*
2963	>	* @return true if now too small, so should be untreeified
2964	>	*/
2965	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2966	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2967	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2968	>	TreeNode<K,V> r, rl;
2969	>	if (pred == null)
2970	>	first = next;
2971	>	else
2972	>	pred.next = next;
2973	>	if (next != null)
2974	>	next.prev = pred;
2975	>	if (first == null) {
2976	>	root = null;
2977	>	return true;
2978	>	}
2979	>	if ((r = root) == null || r.right == null || // too small
2980	>	(rl = r.left) == null || rl.left == null)
2981	>	return true;
2982	>	lockRoot();
2983	>	try {
2984	>	TreeNode<K,V> replacement;
2985	>	TreeNode<K,V> pl = p.left;
2986	>	TreeNode<K,V> pr = p.right;
2987	>	if (pl != null && pr != null) {
2988	>	TreeNode<K,V> s = pr, sl;
2989	>	while ((sl = s.left) != null) // find successor
2990	>	s = sl;
2991	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2992	>	TreeNode<K,V> sr = s.right;
2993	>	TreeNode<K,V> pp = p.parent;
2994	>	if (s == pr) { // p was s's direct parent
2995	>	p.parent = s;
2996	>	s.right = p;
2997	>	}
2998	>	else {
2999	>	TreeNode<K,V> sp = s.parent;
3000	>	if ((p.parent = sp) != null) {
3001	>	if (s == sp.left)
3002	>	sp.left = p;
3003	>	else
3004	>	sp.right = p;
3005	>	}
3006	>	if ((s.right = pr) != null)
3007	>	pr.parent = s;
3008	>	}
3009	>	p.left = null;
3010	>	if ((p.right = sr) != null)
3011	>	sr.parent = p;
3012	>	if ((s.left = pl) != null)
3013	>	pl.parent = s;
3014	>	if ((s.parent = pp) == null)
3015	>	r = s;
3016	>	else if (p == pp.left)
3017	>	pp.left = s;
3018	>	else
3019	>	pp.right = s;
3020	>	if (sr != null)
3021	>	replacement = sr;
3022	>	else
3023	>	replacement = p;
3024	>	}
3025	>	else if (pl != null)
3026	>	replacement = pl;
3027	>	else if (pr != null)
3028	>	replacement = pr;
3029	>	else
3030	>	replacement = p;
3031	>	if (replacement != p) {
3032	>	TreeNode<K,V> pp = replacement.parent = p.parent;
3033	>	if (pp == null)
3034	>	r = replacement;
3035	>	else if (p == pp.left)
3036	>	pp.left = replacement;
3037	>	else
3038	>	pp.right = replacement;
3039	>	p.left = p.right = p.parent = null;
3040	>	}
3041	>
3042	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3043	>
3044	>	if (p == replacement) {  // detach pointers
3045	>	TreeNode<K,V> pp;
3046	>	if ((pp = p.parent) != null) {
3047	>	if (p == pp.left)
3048	>	pp.left = null;
3049	>	else if (p == pp.right)
3050	>	pp.right = null;
3051	>	p.parent = null;
3052	>	}
3053	>	}
3054	>	} finally {
3055	>	unlockRoot();
3056	>	}
3057	>	assert checkInvariants(root);
3058	>	return false;
3059	>	}
3060	>
3061	>	/* ------------------------------------------------------------ */
3062	>	// Red-black tree methods, all adapted from CLR
3063	>
3064	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3065	>	TreeNode<K,V> p) {
3066	>	TreeNode<K,V> r, pp, rl;
3067	>	if (p != null && (r = p.right) != null) {
3068	>	if ((rl = p.right = r.left) != null)
3069	>	rl.parent = p;
3070	>	if ((pp = r.parent = p.parent) == null)
3071	>	(root = r).red = false;
3072	>	else if (pp.left == p)
3073	>	pp.left = r;
3074	>	else
3075	>	pp.right = r;
3076	>	r.left = p;
3077	>	p.parent = r;
3078	>	}
3079	>	return root;
3080	>	}
3081	>
3082	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3083	>	TreeNode<K,V> p) {
3084	>	TreeNode<K,V> l, pp, lr;
3085	>	if (p != null && (l = p.left) != null) {
3086	>	if ((lr = p.left = l.right) != null)
3087	>	lr.parent = p;
3088	>	if ((pp = l.parent = p.parent) == null)
3089	>	(root = l).red = false;
3090	>	else if (pp.right == p)
3091	>	pp.right = l;
3092	>	else
3093	>	pp.left = l;
3094	>	l.right = p;
3095	>	p.parent = l;
3096	>	}
3097	>	return root;
3098	>	}
3099	>
3100	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3101	>	TreeNode<K,V> x) {
3102	>	x.red = true;
3103	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3104	>	if ((xp = x.parent) == null) {
3105	>	x.red = false;
3106	>	return x;
3107	>	}
3108	>	else if (!xp.red || (xpp = xp.parent) == null)
3109	>	return root;
3110	>	if (xp == (xppl = xpp.left)) {
3111	>	if ((xppr = xpp.right) != null && xppr.red) {
3112	>	xppr.red = false;
3113	>	xp.red = false;
3114	>	xpp.red = true;
3115	>	x = xpp;
3116	>	}
3117	>	else {
3118	>	if (x == xp.right) {
3119	>	root = rotateLeft(root, x = xp);
3120	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3121	>	}
3122	>	if (xp != null) {
3123	>	xp.red = false;
3124	>	if (xpp != null) {
3125	>	xpp.red = true;
3126	>	root = rotateRight(root, xpp);
3127	>	}
3128	>	}
3129	>	}
3130	>	}
3131	>	else {
3132	>	if (xppl != null && xppl.red) {
3133	>	xppl.red = false;
3134	>	xp.red = false;
3135	>	xpp.red = true;
3136	>	x = xpp;
3137	>	}
3138	>	else {
3139	>	if (x == xp.left) {
3140	>	root = rotateRight(root, x = xp);
3141	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3142	>	}
3143	>	if (xp != null) {
3144	>	xp.red = false;
3145	>	if (xpp != null) {
3146	>	xpp.red = true;
3147	>	root = rotateLeft(root, xpp);
3148	>	}
3149	>	}
3150	>	}
3151	>	}
3152	>	}
3153	>	}
3154	>
3155	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3156	>	TreeNode<K,V> x) {
3157	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3158	>	if (x == null || x == root)
3159	>	return root;
3160	>	else if ((xp = x.parent) == null) {
3161	>	x.red = false;
3162	>	return x;
3163	>	}
3164	>	else if (x.red) {
3165	>	x.red = false;
3166	>	return root;
3167	>	}
3168	>	else if ((xpl = xp.left) == x) {
3169	>	if ((xpr = xp.right) != null && xpr.red) {
3170	>	xpr.red = false;
3171	>	xp.red = true;
3172	>	root = rotateLeft(root, xp);
3173	>	xpr = (xp = x.parent) == null ? null : xp.right;
3174	>	}
3175	>	if (xpr == null)
3176	>	x = xp;
3177	>	else {
3178	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3179	>	if ((sr == null || !sr.red) &&
3180	>	(sl == null || !sl.red)) {
3181	>	xpr.red = true;
3182	>	x = xp;
3183	>	}
3184	>	else {
3185	>	if (sr == null || !sr.red) {
3186	>	if (sl != null)
3187	>	sl.red = false;
3188	>	xpr.red = true;
3189	>	root = rotateRight(root, xpr);
3190	>	xpr = (xp = x.parent) == null ?
3191	>	null : xp.right;
3192	>	}
3193	>	if (xpr != null) {
3194	>	xpr.red = (xp == null) ? false : xp.red;
3195	>	if ((sr = xpr.right) != null)
3196	>	sr.red = false;
3197	>	}
3198	>	if (xp != null) {
3199	>	xp.red = false;
3200	>	root = rotateLeft(root, xp);
3201	>	}
3202	>	x = root;
3203	>	}
3204	>	}
3205	>	}
3206	>	else { // symmetric
3207	>	if (xpl != null && xpl.red) {
3208	>	xpl.red = false;
3209	>	xp.red = true;
3210	>	root = rotateRight(root, xp);
3211	>	xpl = (xp = x.parent) == null ? null : xp.left;
3212	>	}
3213	>	if (xpl == null)
3214	>	x = xp;
3215	>	else {
3216	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3217	>	if ((sl == null || !sl.red) &&
3218	>	(sr == null || !sr.red)) {
3219	>	xpl.red = true;
3220	>	x = xp;
3221	>	}
3222	>	else {
3223	>	if (sl == null || !sl.red) {
3224	>	if (sr != null)
3225	>	sr.red = false;
3226	>	xpl.red = true;
3227	>	root = rotateLeft(root, xpl);
3228	>	xpl = (xp = x.parent) == null ?
3229	>	null : xp.left;
3230	>	}
3231	>	if (xpl != null) {
3232	>	xpl.red = (xp == null) ? false : xp.red;
3233	>	if ((sl = xpl.left) != null)
3234	>	sl.red = false;
3235	>	}
3236	>	if (xp != null) {
3237	>	xp.red = false;
3238	>	root = rotateRight(root, xp);
3239	>	}
3240	>	x = root;
3241	>	}
3242	>	}
3243	>	}
3244	>	}
3245	>	}
3246	>
3247	>	/**
3248	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3249	>	*/
3250	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3251	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3252	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3253	>	if (tb != null && tb.next != t)
3254	>	return false;
3255	>	if (tn != null && tn.prev != t)
3256	>	return false;
3257	>	if (tp != null && t != tp.left && t != tp.right)
3258	>	return false;
3259	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3260	>	return false;
3261	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3262	>	return false;
3263	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3264	>	return false;
3265	>	if (tl != null && !checkInvariants(tl))
3266	>	return false;
3267	>	if (tr != null && !checkInvariants(tr))
3268	>	return false;
3269	>	return true;
3270	>	}
3271	>
3272	>	private static final jdk.internal.misc.Unsafe U = jdk.internal.misc.Unsafe.getUnsafe();
3273	>	private static final long LOCKSTATE;
3274	>	static {
3275	>	try {
3276	>	LOCKSTATE = U.objectFieldOffset
3277	>	(TreeBin.class.getDeclaredField("lockState"));
3278	>	} catch (ReflectiveOperationException e) {
3279	>	throw new Error(e);
3280	>	}
3281	>	}
3282	>	}
3283	>
3284	>	/* ----------------Table Traversal -------------- */
3285	>
3286	>	/**
3287	>	* Records the table, its length, and current traversal index for a
3288	>	* traverser that must process a region of a forwarded table before
3289	>	* proceeding with current table.
3290	>	*/
3291	>	static final class TableStack<K,V> {
3292	>	int length;
3293	>	int index;
3294	>	Node<K,V>[] tab;
3295	>	TableStack<K,V> next;
3296	>	}
3297	>
3298	>	/**
3299	>	* Encapsulates traversal for methods such as containsValue; also
3300	>	* serves as a base class for other iterators and spliterators.
3301	>	*
3302	>	* Method advance visits once each still-valid node that was
3303	>	* reachable upon iterator construction. It might miss some that
3304	>	* were added to a bin after the bin was visited, which is OK wrt
3305	>	* consistency guarantees. Maintaining this property in the face
3306	>	* of possible ongoing resizes requires a fair amount of
3307	>	* bookkeeping state that is difficult to optimize away amidst
3308	>	* volatile accesses.  Even so, traversal maintains reasonable
3309	>	* throughput.
3310	>	*
3311	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3312	>	* However, if the table has been resized, then all future steps
3313	>	* must traverse both the bin at the current index as well as at
3314	>	* (index + baseSize); and so on for further resizings. To
3315	>	* paranoically cope with potential sharing by users of iterators
3316	>	* across threads, iteration terminates if a bounds checks fails
3317	>	* for a table read.
3318	>	*/
3319	>	static class Traverser<K,V> {
3320	>	Node<K,V>[] tab;        // current table; updated if resized
3321	>	Node<K,V> next;         // the next entry to use
3322	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3323	>	int index;              // index of bin to use next
3324	>	int baseIndex;          // current index of initial table
3325	>	int baseLimit;          // index bound for initial table
3326	>	final int baseSize;     // initial table size
3327	>
3328	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3329	>	this.tab = tab;
3330	>	this.baseSize = size;
3331	>	this.baseIndex = this.index = index;
3332	>	this.baseLimit = limit;
3333	>	this.next = null;
3334	>	}
3335	>
3336	>	/**
3337	>	* Advances if possible, returning next valid node, or null if none.
3338	>	*/
3339	>	final Node<K,V> advance() {
3340	>	Node<K,V> e;
3341	>	if ((e = next) != null)
3342	>	e = e.next;
3343	>	for (;;) {
3344	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3345	>	if (e != null)
3346	>	return next = e;
3347	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3348	>	(n = t.length) <= (i = index) || i < 0)
3349	>	return next = null;
3350	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3351	>	if (e instanceof ForwardingNode) {
3352	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3353	>	e = null;
3354	>	pushState(t, i, n);
3355	>	continue;
3356	>	}
3357	>	else if (e instanceof TreeBin)
3358	>	e = ((TreeBin<K,V>)e).first;
3359	>	else
3360	>	e = null;
3361	>	}
3362	>	if (stack != null)
3363	>	recoverState(n);
3364	>	else if ((index = i + baseSize) >= n)
3365	>	index = ++baseIndex; // visit upper slots if present
3366	>	}
3367	>	}
3368	>
3369	>	/**
3370	>	* Saves traversal state upon encountering a forwarding node.
3371	>	*/
3372	>	private void pushState(Node<K,V>[] t, int i, int n) {
3373	>	TableStack<K,V> s = spare;  // reuse if possible
3374	>	if (s != null)
3375	>	spare = s.next;
3376	>	else
3377	>	s = new TableStack<K,V>();
3378	>	s.tab = t;
3379	>	s.length = n;
3380	>	s.index = i;
3381	>	s.next = stack;
3382	>	stack = s;
3383	>	}
3384	>
3385	>	/**
3386	>	* Possibly pops traversal state.
3387	>	*
3388	>	* @param n length of current table
3389	>	*/
3390	>	private void recoverState(int n) {
3391	>	TableStack<K,V> s; int len;
3392	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3393	>	n = len;
3394	>	index = s.index;
3395	>	tab = s.tab;
3396	>	s.tab = null;
3397	>	TableStack<K,V> next = s.next;
3398	>	s.next = spare; // save for reuse
3399	>	stack = next;
3400	>	spare = s;
3401	>	}
3402	>	if (s == null && (index += baseSize) >= n)
3403	>	index = ++baseIndex;
3404	>	}
3405	>	}
3406	>
3407	>	/**
3408	>	* Base of key, value, and entry Iterators. Adds fields to
3409	>	* Traverser to support iterator.remove.
3410	>	*/
3411	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3412	>	final ConcurrentHashMap<K,V> map;
3413	>	Node<K,V> lastReturned;
3414	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3415	>	ConcurrentHashMap<K,V> map) {
3416	>	super(tab, size, index, limit);
3417	>	this.map = map;
3418		advance();
1101	–	return lastReturned;
3419		}
3420
3421	<	public void remove() {
3422	<	if (lastReturned == null)
3421	>	public final boolean hasNext() { return next != null; }
3422	>	public final boolean hasMoreElements() { return next != null; }
3423	>
3424	>	public final void remove() {
3425	>	Node<K,V> p;
3426	>	if ((p = lastReturned) == null)
3427		throw new IllegalStateException();
1107	–	ConcurrentHashMap.this.remove(lastReturned.key);
3428		lastReturned = null;
3429	+	map.replaceNode(p.key, null, null);
3430	+	}
3431	+	}
3432	+
3433	+	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3434	+	implements Iterator<K>, Enumeration<K> {
3435	+	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3436	+	ConcurrentHashMap<K,V> map) {
3437	+	super(tab, index, size, limit, map);
3438		}
3439	+
3440	+	public final K next() {
3441	+	Node<K,V> p;
3442	+	if ((p = next) == null)
3443	+	throw new NoSuchElementException();
3444	+	K k = p.key;
3445	+	lastReturned = p;
3446	+	advance();
3447	+	return k;
3448	+	}
3449	+
3450	+	public final K nextElement() { return next(); }
3451		}
3452
3453	<	final class KeyIterator
3454	<	extends HashIterator
3455	<	implements Iterator<K>, Enumeration<K>
3456	<	{
3457	<	public K next()        { return super.nextEntry().key; }
3458	<	public K nextElement() { return super.nextEntry().key; }
3453	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3454	>	implements Iterator<V>, Enumeration<V> {
3455	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3456	>	ConcurrentHashMap<K,V> map) {
3457	>	super(tab, index, size, limit, map);
3458	>	}
3459	>
3460	>	public final V next() {
3461	>	Node<K,V> p;
3462	>	if ((p = next) == null)
3463	>	throw new NoSuchElementException();
3464	>	V v = p.val;
3465	>	lastReturned = p;
3466	>	advance();
3467	>	return v;
3468	>	}
3469	>
3470	>	public final V nextElement() { return next(); }
3471		}
3472
3473	<	final class ValueIterator
3474	<	extends HashIterator
3475	<	implements Iterator<V>, Enumeration<V>
3476	<	{
3477	<	public V next()        { return super.nextEntry().value; }
3478	<	public V nextElement() { return super.nextEntry().value; }
3473	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3474	>	implements Iterator<Map.Entry<K,V>> {
3475	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3476	>	ConcurrentHashMap<K,V> map) {
3477	>	super(tab, index, size, limit, map);
3478	>	}
3479	>
3480	>	public final Map.Entry<K,V> next() {
3481	>	Node<K,V> p;
3482	>	if ((p = next) == null)
3483	>	throw new NoSuchElementException();
3484	>	K k = p.key;
3485	>	V v = p.val;
3486	>	lastReturned = p;
3487	>	advance();
3488	>	return new MapEntry<K,V>(k, v, map);
3489	>	}
3490		}
3491
3492		/**
3493	<	* Custom Entry class used by EntryIterator.next(), that relays
1130	<	* setValue changes to the underlying map.
3493	>	* Exported Entry for EntryIterator.
3494		*/
3495	<	final class WriteThroughEntry
3496	<	extends AbstractMap.SimpleEntry<K,V>
3497	<	{
3498	<	WriteThroughEntry(K k, V v) {
3499	<	super(k,v);
3495	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3496	>	final K key; // non-null
3497	>	V val;       // non-null
3498	>	final ConcurrentHashMap<K,V> map;
3499	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3500	>	this.key = key;
3501	>	this.val = val;
3502	>	this.map = map;
3503	>	}
3504	>	public K getKey()        { return key; }
3505	>	public V getValue()      { return val; }
3506	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3507	>	public String toString() {
3508	>	return Helpers.mapEntryToString(key, val);
3509	>	}
3510	>
3511	>	public boolean equals(Object o) {
3512	>	Object k, v; Map.Entry<?,?> e;
3513	>	return ((o instanceof Map.Entry) &&
3514	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3515	>	(v = e.getValue()) != null &&
3516	>	(k == key || k.equals(key)) &&
3517	>	(v == val || v.equals(val)));
3518		}
3519
3520		/**
3521	<	* Set our entry's value and write through to the map. The
3522	<	* value to return is somewhat arbitrary here. Since a
3523	<	* WriteThroughEntry does not necessarily track asynchronous
3524	<	* changes, the most recent "previous" value could be
3525	<	* different from what we return (or could even have been
3526	<	* removed in which case the put will re-establish). We do not
1146	<	* and cannot guarantee more.
3521	>	* Sets our entry's value and writes through to the map. The
3522	>	* value to return is somewhat arbitrary here. Since we do not
3523	>	* necessarily track asynchronous changes, the most recent
3524	>	* "previous" value could be different from what we return (or
3525	>	* could even have been removed, in which case the put will
3526	>	* re-establish). We do not and cannot guarantee more.
3527		*/
3528	<	public V setValue(V value) {
3528	>	public V setValue(V value) {
3529		if (value == null) throw new NullPointerException();
3530	<	V v = super.setValue(value);
3531	<	ConcurrentHashMap.this.put(getKey(), value);
3530	>	V v = val;
3531	>	val = value;
3532	>	map.put(key, value);
3533		return v;
3534		}
3535		}
3536
3537	<	final class EntryIterator
3538	<	extends HashIterator
3539	<	implements Iterator<Entry<K,V>>
3540	<	{
3541	<	public Map.Entry<K,V> next() {
3542	<	HashEntry<K,V> e = super.nextEntry();
3543	<	return new WriteThroughEntry(e.key, e.value);
3537	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3538	>	implements Spliterator<K> {
3539	>	long est;               // size estimate
3540	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3541	>	long est) {
3542	>	super(tab, size, index, limit);
3543	>	this.est = est;
3544	>	}
3545	>
3546	>	public KeySpliterator<K,V> trySplit() {
3547	>	int i, f, h;
3548	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3549	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3550	>	f, est >>>= 1);
3551	>	}
3552	>
3553	>	public void forEachRemaining(Consumer<? super K> action) {
3554	>	if (action == null) throw new NullPointerException();
3555	>	for (Node<K,V> p; (p = advance()) != null;)
3556	>	action.accept(p.key);
3557	>	}
3558	>
3559	>	public boolean tryAdvance(Consumer<? super K> action) {
3560	>	if (action == null) throw new NullPointerException();
3561	>	Node<K,V> p;
3562	>	if ((p = advance()) == null)
3563	>	return false;
3564	>	action.accept(p.key);
3565	>	return true;
3566	>	}
3567	>
3568	>	public long estimateSize() { return est; }
3569	>
3570	>	public int characteristics() {
3571	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3572	>	Spliterator.NONNULL;
3573		}
3574		}
3575
3576	<	final class KeySet extends AbstractSet<K> {
3577	<	public Iterator<K> iterator() {
3578	<	return new KeyIterator();
3576	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3577	>	implements Spliterator<V> {
3578	>	long est;               // size estimate
3579	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3580	>	long est) {
3581	>	super(tab, size, index, limit);
3582	>	this.est = est;
3583	>	}
3584	>
3585	>	public ValueSpliterator<K,V> trySplit() {
3586	>	int i, f, h;
3587	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3588	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3589	>	f, est >>>= 1);
3590	>	}
3591	>
3592	>	public void forEachRemaining(Consumer<? super V> action) {
3593	>	if (action == null) throw new NullPointerException();
3594	>	for (Node<K,V> p; (p = advance()) != null;)
3595	>	action.accept(p.val);
3596	>	}
3597	>
3598	>	public boolean tryAdvance(Consumer<? super V> action) {
3599	>	if (action == null) throw new NullPointerException();
3600	>	Node<K,V> p;
3601	>	if ((p = advance()) == null)
3602	>	return false;
3603	>	action.accept(p.val);
3604	>	return true;
3605		}
3606	<	public int size() {
3607	<	return ConcurrentHashMap.this.size();
3606	>
3607	>	public long estimateSize() { return est; }
3608	>
3609	>	public int characteristics() {
3610	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3611		}
3612	<	public boolean contains(Object o) {
3613	<	return ConcurrentHashMap.this.containsKey(o);
3612	>	}
3613	>
3614	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3615	>	implements Spliterator<Map.Entry<K,V>> {
3616	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3617	>	long est;               // size estimate
3618	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3619	>	long est, ConcurrentHashMap<K,V> map) {
3620	>	super(tab, size, index, limit);
3621	>	this.map = map;
3622	>	this.est = est;
3623	>	}
3624	>
3625	>	public EntrySpliterator<K,V> trySplit() {
3626	>	int i, f, h;
3627	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3628	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3629	>	f, est >>>= 1, map);
3630	>	}
3631	>
3632	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3633	>	if (action == null) throw new NullPointerException();
3634	>	for (Node<K,V> p; (p = advance()) != null; )
3635	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3636	>	}
3637	>
3638	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3639	>	if (action == null) throw new NullPointerException();
3640	>	Node<K,V> p;
3641	>	if ((p = advance()) == null)
3642	>	return false;
3643	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3644	>	return true;
3645		}
3646	<	public boolean remove(Object o) {
3647	<	return ConcurrentHashMap.this.remove(o) != null;
3646	>
3647	>	public long estimateSize() { return est; }
3648	>
3649	>	public int characteristics() {
3650	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3651	>	Spliterator.NONNULL;
3652		}
3653	<	public void clear() {
3654	<	ConcurrentHashMap.this.clear();
3653	>	}
3654	>
3655	>	// Parallel bulk operations
3656	>
3657	>	/**
3658	>	* Computes initial batch value for bulk tasks. The returned value
3659	>	* is approximately exp2 of the number of times (minus one) to
3660	>	* split task by two before executing leaf action. This value is
3661	>	* faster to compute and more convenient to use as a guide to
3662	>	* splitting than is the depth, since it is used while dividing by
3663	>	* two anyway.
3664	>	*/
3665	>	final int batchFor(long b) {
3666	>	long n;
3667	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3668	>	return 0;
3669	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3670	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3671	>	}
3672	>
3673	>	/**
3674	>	* Performs the given action for each (key, value).
3675	>	*
3676	>	* @param parallelismThreshold the (estimated) number of elements
3677	>	* needed for this operation to be executed in parallel
3678	>	* @param action the action
3679	>	* @since 1.8
3680	>	*/
3681	>	public void forEach(long parallelismThreshold,
3682	>	BiConsumer<? super K,? super V> action) {
3683	>	if (action == null) throw new NullPointerException();
3684	>	new ForEachMappingTask<K,V>
3685	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3686	>	action).invoke();
3687	>	}
3688	>
3689	>	/**
3690	>	* Performs the given action for each non-null transformation
3691	>	* of each (key, value).
3692	>	*
3693	>	* @param parallelismThreshold the (estimated) number of elements
3694	>	* needed for this operation to be executed in parallel
3695	>	* @param transformer a function returning the transformation
3696	>	* for an element, or null if there is no transformation (in
3697	>	* which case the action is not applied)
3698	>	* @param action the action
3699	>	* @param <U> the return type of the transformer
3700	>	* @since 1.8
3701	>	*/
3702	>	public <U> void forEach(long parallelismThreshold,
3703	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3704	>	Consumer<? super U> action) {
3705	>	if (transformer == null || action == null)
3706	>	throw new NullPointerException();
3707	>	new ForEachTransformedMappingTask<K,V,U>
3708	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3709	>	transformer, action).invoke();
3710	>	}
3711	>
3712	>	/**
3713	>	* Returns a non-null result from applying the given search
3714	>	* function on each (key, value), or null if none.  Upon
3715	>	* success, further element processing is suppressed and the
3716	>	* results of any other parallel invocations of the search
3717	>	* function are ignored.
3718	>	*
3719	>	* @param parallelismThreshold the (estimated) number of elements
3720	>	* needed for this operation to be executed in parallel
3721	>	* @param searchFunction a function returning a non-null
3722	>	* result on success, else null
3723	>	* @param <U> the return type of the search function
3724	>	* @return a non-null result from applying the given search
3725	>	* function on each (key, value), or null if none
3726	>	* @since 1.8
3727	>	*/
3728	>	public <U> U search(long parallelismThreshold,
3729	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3730	>	if (searchFunction == null) throw new NullPointerException();
3731	>	return new SearchMappingsTask<K,V,U>
3732	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3733	>	searchFunction, new AtomicReference<U>()).invoke();
3734	>	}
3735	>
3736	>	/**
3737	>	* Returns the result of accumulating the given transformation
3738	>	* of all (key, value) pairs using the given reducer to
3739	>	* combine values, or null if none.
3740	>	*
3741	>	* @param parallelismThreshold the (estimated) number of elements
3742	>	* needed for this operation to be executed in parallel
3743	>	* @param transformer a function returning the transformation
3744	>	* for an element, or null if there is no transformation (in
3745	>	* which case it is not combined)
3746	>	* @param reducer a commutative associative combining function
3747	>	* @param <U> the return type of the transformer
3748	>	* @return the result of accumulating the given transformation
3749	>	* of all (key, value) pairs
3750	>	* @since 1.8
3751	>	*/
3752	>	public <U> U reduce(long parallelismThreshold,
3753	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3754	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3755	>	if (transformer == null || reducer == null)
3756	>	throw new NullPointerException();
3757	>	return new MapReduceMappingsTask<K,V,U>
3758	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3759	>	null, transformer, reducer).invoke();
3760	>	}
3761	>
3762	>	/**
3763	>	* Returns the result of accumulating the given transformation
3764	>	* of all (key, value) pairs using the given reducer to
3765	>	* combine values, and the given basis as an identity value.
3766	>	*
3767	>	* @param parallelismThreshold the (estimated) number of elements
3768	>	* needed for this operation to be executed in parallel
3769	>	* @param transformer a function returning the transformation
3770	>	* for an element
3771	>	* @param basis the identity (initial default value) for the reduction
3772	>	* @param reducer a commutative associative combining function
3773	>	* @return the result of accumulating the given transformation
3774	>	* of all (key, value) pairs
3775	>	* @since 1.8
3776	>	*/
3777	>	public double reduceToDouble(long parallelismThreshold,
3778	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3779	>	double basis,
3780	>	DoubleBinaryOperator reducer) {
3781	>	if (transformer == null || reducer == null)
3782	>	throw new NullPointerException();
3783	>	return new MapReduceMappingsToDoubleTask<K,V>
3784	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3785	>	null, transformer, basis, reducer).invoke();
3786	>	}
3787	>
3788	>	/**
3789	>	* Returns the result of accumulating the given transformation
3790	>	* of all (key, value) pairs using the given reducer to
3791	>	* combine values, and the given basis as an identity value.
3792	>	*
3793	>	* @param parallelismThreshold the (estimated) number of elements
3794	>	* needed for this operation to be executed in parallel
3795	>	* @param transformer a function returning the transformation
3796	>	* for an element
3797	>	* @param basis the identity (initial default value) for the reduction
3798	>	* @param reducer a commutative associative combining function
3799	>	* @return the result of accumulating the given transformation
3800	>	* of all (key, value) pairs
3801	>	* @since 1.8
3802	>	*/
3803	>	public long reduceToLong(long parallelismThreshold,
3804	>	ToLongBiFunction<? super K, ? super V> transformer,
3805	>	long basis,
3806	>	LongBinaryOperator reducer) {
3807	>	if (transformer == null || reducer == null)
3808	>	throw new NullPointerException();
3809	>	return new MapReduceMappingsToLongTask<K,V>
3810	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3811	>	null, transformer, basis, reducer).invoke();
3812	>	}
3813	>
3814	>	/**
3815	>	* Returns the result of accumulating the given transformation
3816	>	* of all (key, value) pairs using the given reducer to
3817	>	* combine values, and the given basis as an identity value.
3818	>	*
3819	>	* @param parallelismThreshold the (estimated) number of elements
3820	>	* needed for this operation to be executed in parallel
3821	>	* @param transformer a function returning the transformation
3822	>	* for an element
3823	>	* @param basis the identity (initial default value) for the reduction
3824	>	* @param reducer a commutative associative combining function
3825	>	* @return the result of accumulating the given transformation
3826	>	* of all (key, value) pairs
3827	>	* @since 1.8
3828	>	*/
3829	>	public int reduceToInt(long parallelismThreshold,
3830	>	ToIntBiFunction<? super K, ? super V> transformer,
3831	>	int basis,
3832	>	IntBinaryOperator reducer) {
3833	>	if (transformer == null || reducer == null)
3834	>	throw new NullPointerException();
3835	>	return new MapReduceMappingsToIntTask<K,V>
3836	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3837	>	null, transformer, basis, reducer).invoke();
3838	>	}
3839	>
3840	>	/**
3841	>	* Performs the given action for each key.
3842	>	*
3843	>	* @param parallelismThreshold the (estimated) number of elements
3844	>	* needed for this operation to be executed in parallel
3845	>	* @param action the action
3846	>	* @since 1.8
3847	>	*/
3848	>	public void forEachKey(long parallelismThreshold,
3849	>	Consumer<? super K> action) {
3850	>	if (action == null) throw new NullPointerException();
3851	>	new ForEachKeyTask<K,V>
3852	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3853	>	action).invoke();
3854	>	}
3855	>
3856	>	/**
3857	>	* Performs the given action for each non-null transformation
3858	>	* of each key.
3859	>	*
3860	>	* @param parallelismThreshold the (estimated) number of elements
3861	>	* needed for this operation to be executed in parallel
3862	>	* @param transformer a function returning the transformation
3863	>	* for an element, or null if there is no transformation (in
3864	>	* which case the action is not applied)
3865	>	* @param action the action
3866	>	* @param <U> the return type of the transformer
3867	>	* @since 1.8
3868	>	*/
3869	>	public <U> void forEachKey(long parallelismThreshold,
3870	>	Function<? super K, ? extends U> transformer,
3871	>	Consumer<? super U> action) {
3872	>	if (transformer == null || action == null)
3873	>	throw new NullPointerException();
3874	>	new ForEachTransformedKeyTask<K,V,U>
3875	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3876	>	transformer, action).invoke();
3877	>	}
3878	>
3879	>	/**
3880	>	* Returns a non-null result from applying the given search
3881	>	* function on each key, or null if none. Upon success,
3882	>	* further element processing is suppressed and the results of
3883	>	* any other parallel invocations of the search function are
3884	>	* ignored.
3885	>	*
3886	>	* @param parallelismThreshold the (estimated) number of elements
3887	>	* needed for this operation to be executed in parallel
3888	>	* @param searchFunction a function returning a non-null
3889	>	* result on success, else null
3890	>	* @param <U> the return type of the search function
3891	>	* @return a non-null result from applying the given search
3892	>	* function on each key, or null if none
3893	>	* @since 1.8
3894	>	*/
3895	>	public <U> U searchKeys(long parallelismThreshold,
3896	>	Function<? super K, ? extends U> searchFunction) {
3897	>	if (searchFunction == null) throw new NullPointerException();
3898	>	return new SearchKeysTask<K,V,U>
3899	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3900	>	searchFunction, new AtomicReference<U>()).invoke();
3901	>	}
3902	>
3903	>	/**
3904	>	* Returns the result of accumulating all keys using the given
3905	>	* reducer to combine values, or null if none.
3906	>	*
3907	>	* @param parallelismThreshold the (estimated) number of elements
3908	>	* needed for this operation to be executed in parallel
3909	>	* @param reducer a commutative associative combining function
3910	>	* @return the result of accumulating all keys using the given
3911	>	* reducer to combine values, or null if none
3912	>	* @since 1.8
3913	>	*/
3914	>	public K reduceKeys(long parallelismThreshold,
3915	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3916	>	if (reducer == null) throw new NullPointerException();
3917	>	return new ReduceKeysTask<K,V>
3918	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3919	>	null, reducer).invoke();
3920	>	}
3921	>
3922	>	/**
3923	>	* Returns the result of accumulating the given transformation
3924	>	* of all keys using the given reducer to combine values, or
3925	>	* null if none.
3926	>	*
3927	>	* @param parallelismThreshold the (estimated) number of elements
3928	>	* needed for this operation to be executed in parallel
3929	>	* @param transformer a function returning the transformation
3930	>	* for an element, or null if there is no transformation (in
3931	>	* which case it is not combined)
3932	>	* @param reducer a commutative associative combining function
3933	>	* @param <U> the return type of the transformer
3934	>	* @return the result of accumulating the given transformation
3935	>	* of all keys
3936	>	* @since 1.8
3937	>	*/
3938	>	public <U> U reduceKeys(long parallelismThreshold,
3939	>	Function<? super K, ? extends U> transformer,
3940	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3941	>	if (transformer == null || reducer == null)
3942	>	throw new NullPointerException();
3943	>	return new MapReduceKeysTask<K,V,U>
3944	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3945	>	null, transformer, reducer).invoke();
3946	>	}
3947	>
3948	>	/**
3949	>	* Returns the result of accumulating the given transformation
3950	>	* of all keys using the given reducer to combine values, and
3951	>	* the given basis as an identity value.
3952	>	*
3953	>	* @param parallelismThreshold the (estimated) number of elements
3954	>	* needed for this operation to be executed in parallel
3955	>	* @param transformer a function returning the transformation
3956	>	* for an element
3957	>	* @param basis the identity (initial default value) for the reduction
3958	>	* @param reducer a commutative associative combining function
3959	>	* @return the result of accumulating the given transformation
3960	>	* of all keys
3961	>	* @since 1.8
3962	>	*/
3963	>	public double reduceKeysToDouble(long parallelismThreshold,
3964	>	ToDoubleFunction<? super K> transformer,
3965	>	double basis,
3966	>	DoubleBinaryOperator reducer) {
3967	>	if (transformer == null || reducer == null)
3968	>	throw new NullPointerException();
3969	>	return new MapReduceKeysToDoubleTask<K,V>
3970	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3971	>	null, transformer, basis, reducer).invoke();
3972	>	}
3973	>
3974	>	/**
3975	>	* Returns the result of accumulating the given transformation
3976	>	* of all keys using the given reducer to combine values, and
3977	>	* the given basis as an identity value.
3978	>	*
3979	>	* @param parallelismThreshold the (estimated) number of elements
3980	>	* needed for this operation to be executed in parallel
3981	>	* @param transformer a function returning the transformation
3982	>	* for an element
3983	>	* @param basis the identity (initial default value) for the reduction
3984	>	* @param reducer a commutative associative combining function
3985	>	* @return the result of accumulating the given transformation
3986	>	* of all keys
3987	>	* @since 1.8
3988	>	*/
3989	>	public long reduceKeysToLong(long parallelismThreshold,
3990	>	ToLongFunction<? super K> transformer,
3991	>	long basis,
3992	>	LongBinaryOperator reducer) {
3993	>	if (transformer == null || reducer == null)
3994	>	throw new NullPointerException();
3995	>	return new MapReduceKeysToLongTask<K,V>
3996	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3997	>	null, transformer, basis, reducer).invoke();
3998	>	}
3999	>
4000	>	/**
4001	>	* Returns the result of accumulating the given transformation
4002	>	* of all keys using the given reducer to combine values, and
4003	>	* the given basis as an identity value.
4004	>	*
4005	>	* @param parallelismThreshold the (estimated) number of elements
4006	>	* needed for this operation to be executed in parallel
4007	>	* @param transformer a function returning the transformation
4008	>	* for an element
4009	>	* @param basis the identity (initial default value) for the reduction
4010	>	* @param reducer a commutative associative combining function
4011	>	* @return the result of accumulating the given transformation
4012	>	* of all keys
4013	>	* @since 1.8
4014	>	*/
4015	>	public int reduceKeysToInt(long parallelismThreshold,
4016	>	ToIntFunction<? super K> transformer,
4017	>	int basis,
4018	>	IntBinaryOperator reducer) {
4019	>	if (transformer == null || reducer == null)
4020	>	throw new NullPointerException();
4021	>	return new MapReduceKeysToIntTask<K,V>
4022	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4023	>	null, transformer, basis, reducer).invoke();
4024	>	}
4025	>
4026	>	/**
4027	>	* Performs the given action for each value.
4028	>	*
4029	>	* @param parallelismThreshold the (estimated) number of elements
4030	>	* needed for this operation to be executed in parallel
4031	>	* @param action the action
4032	>	* @since 1.8
4033	>	*/
4034	>	public void forEachValue(long parallelismThreshold,
4035	>	Consumer<? super V> action) {
4036	>	if (action == null)
4037	>	throw new NullPointerException();
4038	>	new ForEachValueTask<K,V>
4039	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4040	>	action).invoke();
4041	>	}
4042	>
4043	>	/**
4044	>	* Performs the given action for each non-null transformation
4045	>	* of each value.
4046	>	*
4047	>	* @param parallelismThreshold the (estimated) number of elements
4048	>	* needed for this operation to be executed in parallel
4049	>	* @param transformer a function returning the transformation
4050	>	* for an element, or null if there is no transformation (in
4051	>	* which case the action is not applied)
4052	>	* @param action the action
4053	>	* @param <U> the return type of the transformer
4054	>	* @since 1.8
4055	>	*/
4056	>	public <U> void forEachValue(long parallelismThreshold,
4057	>	Function<? super V, ? extends U> transformer,
4058	>	Consumer<? super U> action) {
4059	>	if (transformer == null || action == null)
4060	>	throw new NullPointerException();
4061	>	new ForEachTransformedValueTask<K,V,U>
4062	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4063	>	transformer, action).invoke();
4064	>	}
4065	>
4066	>	/**
4067	>	* Returns a non-null result from applying the given search
4068	>	* function on each value, or null if none.  Upon success,
4069	>	* further element processing is suppressed and the results of
4070	>	* any other parallel invocations of the search function are
4071	>	* ignored.
4072	>	*
4073	>	* @param parallelismThreshold the (estimated) number of elements
4074	>	* needed for this operation to be executed in parallel
4075	>	* @param searchFunction a function returning a non-null
4076	>	* result on success, else null
4077	>	* @param <U> the return type of the search function
4078	>	* @return a non-null result from applying the given search
4079	>	* function on each value, or null if none
4080	>	* @since 1.8
4081	>	*/
4082	>	public <U> U searchValues(long parallelismThreshold,
4083	>	Function<? super V, ? extends U> searchFunction) {
4084	>	if (searchFunction == null) throw new NullPointerException();
4085	>	return new SearchValuesTask<K,V,U>
4086	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4087	>	searchFunction, new AtomicReference<U>()).invoke();
4088	>	}
4089	>
4090	>	/**
4091	>	* Returns the result of accumulating all values using the
4092	>	* given reducer to combine values, or null if none.
4093	>	*
4094	>	* @param parallelismThreshold the (estimated) number of elements
4095	>	* needed for this operation to be executed in parallel
4096	>	* @param reducer a commutative associative combining function
4097	>	* @return the result of accumulating all values
4098	>	* @since 1.8
4099	>	*/
4100	>	public V reduceValues(long parallelismThreshold,
4101	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4102	>	if (reducer == null) throw new NullPointerException();
4103	>	return new ReduceValuesTask<K,V>
4104	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4105	>	null, reducer).invoke();
4106	>	}
4107	>
4108	>	/**
4109	>	* Returns the result of accumulating the given transformation
4110	>	* of all values using the given reducer to combine values, or
4111	>	* null if none.
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, or null if there is no transformation (in
4117	>	* which case it is not combined)
4118	>	* @param reducer a commutative associative combining function
4119	>	* @param <U> the return type of the transformer
4120	>	* @return the result of accumulating the given transformation
4121	>	* of all values
4122	>	* @since 1.8
4123	>	*/
4124	>	public <U> U reduceValues(long parallelismThreshold,
4125	>	Function<? super V, ? extends U> transformer,
4126	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4127	>	if (transformer == null || reducer == null)
4128	>	throw new NullPointerException();
4129	>	return new MapReduceValuesTask<K,V,U>
4130	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4131	>	null, transformer, reducer).invoke();
4132	>	}
4133	>
4134	>	/**
4135	>	* Returns the result of accumulating the given transformation
4136	>	* of all values 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 values
4147	>	* @since 1.8
4148	>	*/
4149	>	public double reduceValuesToDouble(long parallelismThreshold,
4150	>	ToDoubleFunction<? super V> transformer,
4151	>	double basis,
4152	>	DoubleBinaryOperator reducer) {
4153	>	if (transformer == null || reducer == null)
4154	>	throw new NullPointerException();
4155	>	return new MapReduceValuesToDoubleTask<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 values 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 values
4173	>	* @since 1.8
4174	>	*/
4175	>	public long reduceValuesToLong(long parallelismThreshold,
4176	>	ToLongFunction<? super V> transformer,
4177	>	long basis,
4178	>	LongBinaryOperator reducer) {
4179	>	if (transformer == null || reducer == null)
4180	>	throw new NullPointerException();
4181	>	return new MapReduceValuesToLongTask<K,V>
4182	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4183	>	null, transformer, basis, reducer).invoke();
4184	>	}
4185	>
4186	>	/**
4187	>	* Returns the result of accumulating the given transformation
4188	>	* of all values using the given reducer to combine values,
4189	>	* and the given basis as an identity value.
4190	>	*
4191	>	* @param parallelismThreshold the (estimated) number of elements
4192	>	* needed for this operation to be executed in parallel
4193	>	* @param transformer a function returning the transformation
4194	>	* for an element
4195	>	* @param basis the identity (initial default value) for the reduction
4196	>	* @param reducer a commutative associative combining function
4197	>	* @return the result of accumulating the given transformation
4198	>	* of all values
4199	>	* @since 1.8
4200	>	*/
4201	>	public int reduceValuesToInt(long parallelismThreshold,
4202	>	ToIntFunction<? super V> transformer,
4203	>	int basis,
4204	>	IntBinaryOperator reducer) {
4205	>	if (transformer == null || reducer == null)
4206	>	throw new NullPointerException();
4207	>	return new MapReduceValuesToIntTask<K,V>
4208	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4209	>	null, transformer, basis, reducer).invoke();
4210	>	}
4211	>
4212	>	/**
4213	>	* Performs the given action for each entry.
4214	>	*
4215	>	* @param parallelismThreshold the (estimated) number of elements
4216	>	* needed for this operation to be executed in parallel
4217	>	* @param action the action
4218	>	* @since 1.8
4219	>	*/
4220	>	public void forEachEntry(long parallelismThreshold,
4221	>	Consumer<? super Map.Entry<K,V>> action) {
4222	>	if (action == null) throw new NullPointerException();
4223	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4224	>	action).invoke();
4225	>	}
4226	>
4227	>	/**
4228	>	* Performs the given action for each non-null transformation
4229	>	* of each entry.
4230	>	*
4231	>	* @param parallelismThreshold the (estimated) number of elements
4232	>	* needed for this operation to be executed in parallel
4233	>	* @param transformer a function returning the transformation
4234	>	* for an element, or null if there is no transformation (in
4235	>	* which case the action is not applied)
4236	>	* @param action the action
4237	>	* @param <U> the return type of the transformer
4238	>	* @since 1.8
4239	>	*/
4240	>	public <U> void forEachEntry(long parallelismThreshold,
4241	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4242	>	Consumer<? super U> action) {
4243	>	if (transformer == null || action == null)
4244	>	throw new NullPointerException();
4245	>	new ForEachTransformedEntryTask<K,V,U>
4246	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4247	>	transformer, action).invoke();
4248	>	}
4249	>
4250	>	/**
4251	>	* Returns a non-null result from applying the given search
4252	>	* function on each entry, or null if none.  Upon success,
4253	>	* further element processing is suppressed and the results of
4254	>	* any other parallel invocations of the search function are
4255	>	* ignored.
4256	>	*
4257	>	* @param parallelismThreshold the (estimated) number of elements
4258	>	* needed for this operation to be executed in parallel
4259	>	* @param searchFunction a function returning a non-null
4260	>	* result on success, else null
4261	>	* @param <U> the return type of the search function
4262	>	* @return a non-null result from applying the given search
4263	>	* function on each entry, or null if none
4264	>	* @since 1.8
4265	>	*/
4266	>	public <U> U searchEntries(long parallelismThreshold,
4267	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4268	>	if (searchFunction == null) throw new NullPointerException();
4269	>	return new SearchEntriesTask<K,V,U>
4270	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4271	>	searchFunction, new AtomicReference<U>()).invoke();
4272	>	}
4273	>
4274	>	/**
4275	>	* Returns the result of accumulating all entries using the
4276	>	* given reducer to combine values, or null if none.
4277	>	*
4278	>	* @param parallelismThreshold the (estimated) number of elements
4279	>	* needed for this operation to be executed in parallel
4280	>	* @param reducer a commutative associative combining function
4281	>	* @return the result of accumulating all entries
4282	>	* @since 1.8
4283	>	*/
4284	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4285	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4286	>	if (reducer == null) throw new NullPointerException();
4287	>	return new ReduceEntriesTask<K,V>
4288	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4289	>	null, reducer).invoke();
4290	>	}
4291	>
4292	>	/**
4293	>	* Returns the result of accumulating the given transformation
4294	>	* of all entries using the given reducer to combine values,
4295	>	* or null if none.
4296	>	*
4297	>	* @param parallelismThreshold the (estimated) number of elements
4298	>	* needed for this operation to be executed in parallel
4299	>	* @param transformer a function returning the transformation
4300	>	* for an element, or null if there is no transformation (in
4301	>	* which case it is not combined)
4302	>	* @param reducer a commutative associative combining function
4303	>	* @param <U> the return type of the transformer
4304	>	* @return the result of accumulating the given transformation
4305	>	* of all entries
4306	>	* @since 1.8
4307	>	*/
4308	>	public <U> U reduceEntries(long parallelismThreshold,
4309	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4310	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4311	>	if (transformer == null || reducer == null)
4312	>	throw new NullPointerException();
4313	>	return new MapReduceEntriesTask<K,V,U>
4314	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4315	>	null, transformer, reducer).invoke();
4316	>	}
4317	>
4318	>	/**
4319	>	* Returns the result of accumulating the given transformation
4320	>	* of all entries using the given reducer to combine values,
4321	>	* and the given basis as an identity value.
4322	>	*
4323	>	* @param parallelismThreshold the (estimated) number of elements
4324	>	* needed for this operation to be executed in parallel
4325	>	* @param transformer a function returning the transformation
4326	>	* for an element
4327	>	* @param basis the identity (initial default value) for the reduction
4328	>	* @param reducer a commutative associative combining function
4329	>	* @return the result of accumulating the given transformation
4330	>	* of all entries
4331	>	* @since 1.8
4332	>	*/
4333	>	public double reduceEntriesToDouble(long parallelismThreshold,
4334	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4335	>	double basis,
4336	>	DoubleBinaryOperator reducer) {
4337	>	if (transformer == null || reducer == null)
4338	>	throw new NullPointerException();
4339	>	return new MapReduceEntriesToDoubleTask<K,V>
4340	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4341	>	null, transformer, basis, reducer).invoke();
4342	>	}
4343	>
4344	>	/**
4345	>	* Returns the result of accumulating the given transformation
4346	>	* of all entries using the given reducer to combine values,
4347	>	* and the given basis as an identity value.
4348	>	*
4349	>	* @param parallelismThreshold the (estimated) number of elements
4350	>	* needed for this operation to be executed in parallel
4351	>	* @param transformer a function returning the transformation
4352	>	* for an element
4353	>	* @param basis the identity (initial default value) for the reduction
4354	>	* @param reducer a commutative associative combining function
4355	>	* @return the result of accumulating the given transformation
4356	>	* of all entries
4357	>	* @since 1.8
4358	>	*/
4359	>	public long reduceEntriesToLong(long parallelismThreshold,
4360	>	ToLongFunction<Map.Entry<K,V>> transformer,
4361	>	long basis,
4362	>	LongBinaryOperator reducer) {
4363	>	if (transformer == null || reducer == null)
4364	>	throw new NullPointerException();
4365	>	return new MapReduceEntriesToLongTask<K,V>
4366	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4367	>	null, transformer, basis, reducer).invoke();
4368	>	}
4369	>
4370	>	/**
4371	>	* Returns the result of accumulating the given transformation
4372	>	* of all entries using the given reducer to combine values,
4373	>	* and the given basis as an identity value.
4374	>	*
4375	>	* @param parallelismThreshold the (estimated) number of elements
4376	>	* needed for this operation to be executed in parallel
4377	>	* @param transformer a function returning the transformation
4378	>	* for an element
4379	>	* @param basis the identity (initial default value) for the reduction
4380	>	* @param reducer a commutative associative combining function
4381	>	* @return the result of accumulating the given transformation
4382	>	* of all entries
4383	>	* @since 1.8
4384	>	*/
4385	>	public int reduceEntriesToInt(long parallelismThreshold,
4386	>	ToIntFunction<Map.Entry<K,V>> transformer,
4387	>	int basis,
4388	>	IntBinaryOperator reducer) {
4389	>	if (transformer == null || reducer == null)
4390	>	throw new NullPointerException();
4391	>	return new MapReduceEntriesToIntTask<K,V>
4392	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4393	>	null, transformer, basis, reducer).invoke();
4394	>	}
4395	>
4396	>
4397	>	/* ----------------Views -------------- */
4398	>
4399	>	/**
4400	>	* Base class for views.
4401	>	*/
4402	>	abstract static class CollectionView<K,V,E>
4403	>	implements Collection<E>, java.io.Serializable {
4404	>	private static final long serialVersionUID = 7249069246763182397L;
4405	>	final ConcurrentHashMap<K,V> map;
4406	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4407	>
4408	>	/**
4409	>	* Returns the map backing this view.
4410	>	*
4411	>	* @return the map backing this view
4412	>	*/
4413	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4414	>
4415	>	/**
4416	>	* Removes all of the elements from this view, by removing all
4417	>	* the mappings from the map backing this view.
4418	>	*/
4419	>	public final void clear()      { map.clear(); }
4420	>	public final int size()        { return map.size(); }
4421	>	public final boolean isEmpty() { return map.isEmpty(); }
4422	>
4423	>	// implementations below rely on concrete classes supplying these
4424	>	// abstract methods
4425	>	/**
4426	>	* Returns an iterator over the elements in this collection.
4427	>	*
4428	>	* <p>The returned iterator is
4429	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4430	>	*
4431	>	* @return an iterator over the elements in this collection
4432	>	*/
4433	>	public abstract Iterator<E> iterator();
4434	>	public abstract boolean contains(Object o);
4435	>	public abstract boolean remove(Object o);
4436	>
4437	>	private static final String OOME_MSG = "Required array size too large";
4438	>
4439	>	public final Object[] toArray() {
4440	>	long sz = map.mappingCount();
4441	>	if (sz > MAX_ARRAY_SIZE)
4442	>	throw new OutOfMemoryError(OOME_MSG);
4443	>	int n = (int)sz;
4444	>	Object[] r = new Object[n];
4445	>	int i = 0;
4446	>	for (E e : this) {
4447	>	if (i == n) {
4448	>	if (n >= MAX_ARRAY_SIZE)
4449	>	throw new OutOfMemoryError(OOME_MSG);
4450	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4451	>	n = MAX_ARRAY_SIZE;
4452	>	else
4453	>	n += (n >>> 1) + 1;
4454	>	r = Arrays.copyOf(r, n);
4455	>	}
4456	>	r[i++] = e;
4457	>	}
4458	>	return (i == n) ? r : Arrays.copyOf(r, i);
4459		}
4460	+
4461	+	@SuppressWarnings("unchecked")
4462	+	public final <T> T[] toArray(T[] a) {
4463	+	long sz = map.mappingCount();
4464	+	if (sz > MAX_ARRAY_SIZE)
4465	+	throw new OutOfMemoryError(OOME_MSG);
4466	+	int m = (int)sz;
4467	+	T[] r = (a.length >= m) ? a :
4468	+	(T[])java.lang.reflect.Array
4469	+	.newInstance(a.getClass().getComponentType(), m);
4470	+	int n = r.length;
4471	+	int i = 0;
4472	+	for (E e : this) {
4473	+	if (i == n) {
4474	+	if (n >= MAX_ARRAY_SIZE)
4475	+	throw new OutOfMemoryError(OOME_MSG);
4476	+	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4477	+	n = MAX_ARRAY_SIZE;
4478	+	else
4479	+	n += (n >>> 1) + 1;
4480	+	r = Arrays.copyOf(r, n);
4481	+	}
4482	+	r[i++] = (T)e;
4483	+	}
4484	+	if (a == r && i < n) {
4485	+	r[i] = null; // null-terminate
4486	+	return r;
4487	+	}
4488	+	return (i == n) ? r : Arrays.copyOf(r, i);
4489	+	}
4490	+
4491	+	/**
4492	+	* Returns a string representation of this collection.
4493	+	* The string representation consists of the string representations
4494	+	* of the collection's elements in the order they are returned by
4495	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4496	+	* Adjacent elements are separated by the characters {@code ", "}
4497	+	* (comma and space).  Elements are converted to strings as by
4498	+	* {@link String#valueOf(Object)}.
4499	+	*
4500	+	* @return a string representation of this collection
4501	+	*/
4502	+	public final String toString() {
4503	+	StringBuilder sb = new StringBuilder();
4504	+	sb.append('[');
4505	+	Iterator<E> it = iterator();
4506	+	if (it.hasNext()) {
4507	+	for (;;) {
4508	+	Object e = it.next();
4509	+	sb.append(e == this ? "(this Collection)" : e);
4510	+	if (!it.hasNext())
4511	+	break;
4512	+	sb.append(',').append(' ');
4513	+	}
4514	+	}
4515	+	return sb.append(']').toString();
4516	+	}
4517	+
4518	+	public final boolean containsAll(Collection<?> c) {
4519	+	if (c != this) {
4520	+	for (Object e : c) {
4521	+	if (e == null || !contains(e))
4522	+	return false;
4523	+	}
4524	+	}
4525	+	return true;
4526	+	}
4527	+
4528	+	public final boolean removeAll(Collection<?> c) {
4529	+	if (c == null) throw new NullPointerException();
4530	+	boolean modified = false;
4531	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4532	+	if (c.contains(it.next())) {
4533	+	it.remove();
4534	+	modified = true;
4535	+	}
4536	+	}
4537	+	return modified;
4538	+	}
4539	+
4540	+	public final boolean retainAll(Collection<?> c) {
4541	+	if (c == null) throw new NullPointerException();
4542	+	boolean modified = false;
4543	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4544	+	if (!c.contains(it.next())) {
4545	+	it.remove();
4546	+	modified = true;
4547	+	}
4548	+	}
4549	+	return modified;
4550	+	}
4551	+
4552		}
4553
4554	<	final class Values extends AbstractCollection<V> {
4555	<	public Iterator<V> iterator() {
4556	<	return new ValueIterator();
4554	>	/**
4555	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4556	>	* which additions may optionally be enabled by mapping to a
4557	>	* common value.  This class cannot be directly instantiated.
4558	>	* See {@link #keySet() keySet()},
4559	>	* {@link #keySet(Object) keySet(V)},
4560	>	* {@link #newKeySet() newKeySet()},
4561	>	* {@link #newKeySet(int) newKeySet(int)}.
4562	>	*
4563	>	* @since 1.8
4564	>	*/
4565	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4566	>	implements Set<K>, java.io.Serializable {
4567	>	private static final long serialVersionUID = 7249069246763182397L;
4568	>	private final V value;
4569	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4570	>	super(map);
4571	>	this.value = value;
4572		}
4573	<	public int size() {
4574	<	return ConcurrentHashMap.this.size();
4573	>
4574	>	/**
4575	>	* Returns the default mapped value for additions,
4576	>	* or {@code null} if additions are not supported.
4577	>	*
4578	>	* @return the default mapped value for additions, or {@code null}
4579	>	* if not supported
4580	>	*/
4581	>	public V getMappedValue() { return value; }
4582	>
4583	>	/**
4584	>	* {@inheritDoc}
4585	>	* @throws NullPointerException if the specified key is null
4586	>	*/
4587	>	public boolean contains(Object o) { return map.containsKey(o); }
4588	>
4589	>	/**
4590	>	* Removes the key from this map view, by removing the key (and its
4591	>	* corresponding value) from the backing map.  This method does
4592	>	* nothing if the key is not in the map.
4593	>	*
4594	>	* @param  o the key to be removed from the backing map
4595	>	* @return {@code true} if the backing map contained the specified key
4596	>	* @throws NullPointerException if the specified key is null
4597	>	*/
4598	>	public boolean remove(Object o) { return map.remove(o) != null; }
4599	>
4600	>	/**
4601	>	* @return an iterator over the keys of the backing map
4602	>	*/
4603	>	public Iterator<K> iterator() {
4604	>	Node<K,V>[] t;
4605	>	ConcurrentHashMap<K,V> m = map;
4606	>	int f = (t = m.table) == null ? 0 : t.length;
4607	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4608		}
4609	<	public boolean contains(Object o) {
4610	<	return ConcurrentHashMap.this.containsValue(o);
4609	>
4610	>	/**
4611	>	* Adds the specified key to this set view by mapping the key to
4612	>	* the default mapped value in the backing map, if defined.
4613	>	*
4614	>	* @param e key to be added
4615	>	* @return {@code true} if this set changed as a result of the call
4616	>	* @throws NullPointerException if the specified key is null
4617	>	* @throws UnsupportedOperationException if no default mapped value
4618	>	* for additions was provided
4619	>	*/
4620	>	public boolean add(K e) {
4621	>	V v;
4622	>	if ((v = value) == null)
4623	>	throw new UnsupportedOperationException();
4624	>	return map.putVal(e, v, true) == null;
4625	>	}
4626	>
4627	>	/**
4628	>	* Adds all of the elements in the specified collection to this set,
4629	>	* as if by calling {@link #add} on each one.
4630	>	*
4631	>	* @param c the elements to be inserted into this set
4632	>	* @return {@code true} if this set changed as a result of the call
4633	>	* @throws NullPointerException if the collection or any of its
4634	>	* elements are {@code null}
4635	>	* @throws UnsupportedOperationException if no default mapped value
4636	>	* for additions was provided
4637	>	*/
4638	>	public boolean addAll(Collection<? extends K> c) {
4639	>	boolean added = false;
4640	>	V v;
4641	>	if ((v = value) == null)
4642	>	throw new UnsupportedOperationException();
4643	>	for (K e : c) {
4644	>	if (map.putVal(e, v, true) == null)
4645	>	added = true;
4646	>	}
4647	>	return added;
4648		}
4649	<	public void clear() {
4650	<	ConcurrentHashMap.this.clear();
4649	>
4650	>	public int hashCode() {
4651	>	int h = 0;
4652	>	for (K e : this)
4653	>	h += e.hashCode();
4654	>	return h;
4655	>	}
4656	>
4657	>	public boolean equals(Object o) {
4658	>	Set<?> c;
4659	>	return ((o instanceof Set) &&
4660	>	((c = (Set<?>)o) == this ||
4661	>	(containsAll(c) && c.containsAll(this))));
4662	>	}
4663	>
4664	>	public Spliterator<K> spliterator() {
4665	>	Node<K,V>[] t;
4666	>	ConcurrentHashMap<K,V> m = map;
4667	>	long n = m.sumCount();
4668	>	int f = (t = m.table) == null ? 0 : t.length;
4669	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4670	>	}
4671	>
4672	>	public void forEach(Consumer<? super K> action) {
4673	>	if (action == null) throw new NullPointerException();
4674	>	Node<K,V>[] t;
4675	>	if ((t = map.table) != null) {
4676	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4677	>	for (Node<K,V> p; (p = it.advance()) != null; )
4678	>	action.accept(p.key);
4679	>	}
4680		}
4681		}
4682
4683	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4684	<	public Iterator<Map.Entry<K,V>> iterator() {
4685	<	return new EntryIterator();
4683	>	/**
4684	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4685	>	* values, in which additions are disabled. This class cannot be
4686	>	* directly instantiated. See {@link #values()}.
4687	>	*/
4688	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4689	>	implements Collection<V>, java.io.Serializable {
4690	>	private static final long serialVersionUID = 2249069246763182397L;
4691	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4692	>	public final boolean contains(Object o) {
4693	>	return map.containsValue(o);
4694		}
4695	+
4696	+	public final boolean remove(Object o) {
4697	+	if (o != null) {
4698	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4699	+	if (o.equals(it.next())) {
4700	+	it.remove();
4701	+	return true;
4702	+	}
4703	+	}
4704	+	}
4705	+	return false;
4706	+	}
4707	+
4708	+	public final Iterator<V> iterator() {
4709	+	ConcurrentHashMap<K,V> m = map;
4710	+	Node<K,V>[] t;
4711	+	int f = (t = m.table) == null ? 0 : t.length;
4712	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4713	+	}
4714	+
4715	+	public final boolean add(V e) {
4716	+	throw new UnsupportedOperationException();
4717	+	}
4718	+	public final boolean addAll(Collection<? extends V> c) {
4719	+	throw new UnsupportedOperationException();
4720	+	}
4721	+
4722	+	public boolean removeIf(Predicate<? super V> filter) {
4723	+	return map.removeValueIf(filter);
4724	+	}
4725	+
4726	+	public Spliterator<V> spliterator() {
4727	+	Node<K,V>[] t;
4728	+	ConcurrentHashMap<K,V> m = map;
4729	+	long n = m.sumCount();
4730	+	int f = (t = m.table) == null ? 0 : t.length;
4731	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4732	+	}
4733	+
4734	+	public void forEach(Consumer<? super V> action) {
4735	+	if (action == null) throw new NullPointerException();
4736	+	Node<K,V>[] t;
4737	+	if ((t = map.table) != null) {
4738	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4739	+	for (Node<K,V> p; (p = it.advance()) != null; )
4740	+	action.accept(p.val);
4741	+	}
4742	+	}
4743	+	}
4744	+
4745	+	/**
4746	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4747	+	* entries.  This class cannot be directly instantiated. See
4748	+	* {@link #entrySet()}.
4749	+	*/
4750	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4751	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4752	+	private static final long serialVersionUID = 2249069246763182397L;
4753	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4754	+
4755		public boolean contains(Object o) {
4756	<	if (!(o instanceof Map.Entry))
4757	<	return false;
4758	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4759	<	V v = ConcurrentHashMap.this.get(e.getKey());
4760	<	return v != null && v.equals(e.getValue());
4756	>	Object k, v, r; Map.Entry<?,?> e;
4757	>	return ((o instanceof Map.Entry) &&
4758	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4759	>	(r = map.get(k)) != null &&
4760	>	(v = e.getValue()) != null &&
4761	>	(v == r || v.equals(r)));
4762		}
4763	+
4764		public boolean remove(Object o) {
4765	<	if (!(o instanceof Map.Entry))
4766	<	return false;
4767	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4768	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4765	>	Object k, v; Map.Entry<?,?> e;
4766	>	return ((o instanceof Map.Entry) &&
4767	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4768	>	(v = e.getValue()) != null &&
4769	>	map.remove(k, v));
4770	>	}
4771	>
4772	>	/**
4773	>	* @return an iterator over the entries of the backing map
4774	>	*/
4775	>	public Iterator<Map.Entry<K,V>> iterator() {
4776	>	ConcurrentHashMap<K,V> m = map;
4777	>	Node<K,V>[] t;
4778	>	int f = (t = m.table) == null ? 0 : t.length;
4779	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4780	>	}
4781	>
4782	>	public boolean add(Entry<K,V> e) {
4783	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4784	>	}
4785	>
4786	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4787	>	boolean added = false;
4788	>	for (Entry<K,V> e : c) {
4789	>	if (add(e))
4790	>	added = true;
4791	>	}
4792	>	return added;
4793	>	}
4794	>
4795	>	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4796	>	return map.removeEntryIf(filter);
4797		}
4798	<	public int size() {
4799	<	return ConcurrentHashMap.this.size();
4798	>
4799	>	public final int hashCode() {
4800	>	int h = 0;
4801	>	Node<K,V>[] t;
4802	>	if ((t = map.table) != null) {
4803	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4804	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4805	>	h += p.hashCode();
4806	>	}
4807	>	}
4808	>	return h;
4809		}
4810	<	public void clear() {
4811	<	ConcurrentHashMap.this.clear();
4810	>
4811	>	public final boolean equals(Object o) {
4812	>	Set<?> c;
4813	>	return ((o instanceof Set) &&
4814	>	((c = (Set<?>)o) == this ||
4815	>	(containsAll(c) && c.containsAll(this))));
4816	>	}
4817	>
4818	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4819	>	Node<K,V>[] t;
4820	>	ConcurrentHashMap<K,V> m = map;
4821	>	long n = m.sumCount();
4822	>	int f = (t = m.table) == null ? 0 : t.length;
4823	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4824	>	}
4825	>
4826	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4827	>	if (action == null) throw new NullPointerException();
4828	>	Node<K,V>[] t;
4829	>	if ((t = map.table) != null) {
4830	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4831	>	for (Node<K,V> p; (p = it.advance()) != null; )
4832	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4833	>	}
4834		}
4835	+
4836		}
4837
4838	<	/* ---------------- Serialization Support -------------- */
4838	>	// -------------------------------------------------------
4839
4840		/**
4841	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
4842	<	* 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.
4841	>	* Base class for bulk tasks. Repeats some fields and code from
4842	>	* class Traverser, because we need to subclass CountedCompleter.
4843		*/
4844	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4845	<	s.defaultWriteObject();
4844	>	@SuppressWarnings("serial")
4845	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4846	>	Node<K,V>[] tab;        // same as Traverser
4847	>	Node<K,V> next;
4848	>	TableStack<K,V> stack, spare;
4849	>	int index;
4850	>	int baseIndex;
4851	>	int baseLimit;
4852	>	final int baseSize;
4853	>	int batch;              // split control
4854	>
4855	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4856	>	super(par);
4857	>	this.batch = b;
4858	>	this.index = this.baseIndex = i;
4859	>	if ((this.tab = t) == null)
4860	>	this.baseSize = this.baseLimit = 0;
4861	>	else if (par == null)
4862	>	this.baseSize = this.baseLimit = t.length;
4863	>	else {
4864	>	this.baseLimit = f;
4865	>	this.baseSize = par.baseSize;
4866	>	}
4867	>	}
4868
4869	<	for (int k = 0; k < segments.length; ++k) {
4870	<	Segment<K,V> seg = segments[k];
4871	<	seg.lock();
4872	<	try {
4873	<	HashEntry<K,V>[] tab = seg.table;
4874	<	for (int i = 0; i < tab.length; ++i) {
4875	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
4876	<	s.writeObject(e.key);
4877	<	s.writeObject(e.value);
4869	>	/**
4870	>	* Same as Traverser version.
4871	>	*/
4872	>	final Node<K,V> advance() {
4873	>	Node<K,V> e;
4874	>	if ((e = next) != null)
4875	>	e = e.next;
4876	>	for (;;) {
4877	>	Node<K,V>[] t; int i, n;
4878	>	if (e != null)
4879	>	return next = e;
4880	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4881	>	(n = t.length) <= (i = index) || i < 0)
4882	>	return next = null;
4883	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4884	>	if (e instanceof ForwardingNode) {
4885	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4886	>	e = null;
4887	>	pushState(t, i, n);
4888	>	continue;
4889		}
4890	+	else if (e instanceof TreeBin)
4891	+	e = ((TreeBin<K,V>)e).first;
4892	+	else
4893	+	e = null;
4894		}
4895	<	} finally {
4896	<	seg.unlock();
4895	>	if (stack != null)
4896	>	recoverState(n);
4897	>	else if ((index = i + baseSize) >= n)
4898	>	index = ++baseIndex;
4899		}
4900		}
4901	<	s.writeObject(null);
4902	<	s.writeObject(null);
4901	>
4902	>	private void pushState(Node<K,V>[] t, int i, int n) {
4903	>	TableStack<K,V> s = spare;
4904	>	if (s != null)
4905	>	spare = s.next;
4906	>	else
4907	>	s = new TableStack<K,V>();
4908	>	s.tab = t;
4909	>	s.length = n;
4910	>	s.index = i;
4911	>	s.next = stack;
4912	>	stack = s;
4913	>	}
4914	>
4915	>	private void recoverState(int n) {
4916	>	TableStack<K,V> s; int len;
4917	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4918	>	n = len;
4919	>	index = s.index;
4920	>	tab = s.tab;
4921	>	s.tab = null;
4922	>	TableStack<K,V> next = s.next;
4923	>	s.next = spare; // save for reuse
4924	>	stack = next;
4925	>	spare = s;
4926	>	}
4927	>	if (s == null && (index += baseSize) >= n)
4928	>	index = ++baseIndex;
4929	>	}
4930		}
4931
4932	<	/**
4933	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
4934	<	* stream (i.e., deserialize it).
4935	<	* @param s the stream
4936	<	*/
4937	<	private void readObject(java.io.ObjectInputStream s)
4938	<	throws IOException, ClassNotFoundException  {
4939	<	s.defaultReadObject();
4932	>	/*
4933	>	* Task classes. Coded in a regular but ugly format/style to
4934	>	* simplify checks that each variant differs in the right way from
4935	>	* others. The null screenings exist because compilers cannot tell
4936	>	* that we've already null-checked task arguments, so we force
4937	>	* simplest hoisted bypass to help avoid convoluted traps.
4938	>	*/
4939	>	@SuppressWarnings("serial")
4940	>	static final class ForEachKeyTask<K,V>
4941	>	extends BulkTask<K,V,Void> {
4942	>	final Consumer<? super K> action;
4943	>	ForEachKeyTask
4944	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4945	>	Consumer<? super K> action) {
4946	>	super(p, b, i, f, t);
4947	>	this.action = action;
4948	>	}
4949	>	public final void compute() {
4950	>	final Consumer<? super K> action;
4951	>	if ((action = this.action) != null) {
4952	>	for (int i = baseIndex, f, h; batch > 0 &&
4953	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4954	>	addToPendingCount(1);
4955	>	new ForEachKeyTask<K,V>
4956	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4957	>	action).fork();
4958	>	}
4959	>	for (Node<K,V> p; (p = advance()) != null;)
4960	>	action.accept(p.key);
4961	>	propagateCompletion();
4962	>	}
4963	>	}
4964	>	}
4965
4966	<	// Initialize each segment to be minimally sized, and let grow.
4967	<	for (int i = 0; i < segments.length; ++i) {
4968	<	segments[i].setTable(new HashEntry[1]);
4966	>	@SuppressWarnings("serial")
4967	>	static final class ForEachValueTask<K,V>
4968	>	extends BulkTask<K,V,Void> {
4969	>	final Consumer<? super V> action;
4970	>	ForEachValueTask
4971	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4972	>	Consumer<? super V> action) {
4973	>	super(p, b, i, f, t);
4974	>	this.action = action;
4975	>	}
4976	>	public final void compute() {
4977	>	final Consumer<? super V> action;
4978	>	if ((action = this.action) != null) {
4979	>	for (int i = baseIndex, f, h; batch > 0 &&
4980	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4981	>	addToPendingCount(1);
4982	>	new ForEachValueTask<K,V>
4983	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4984	>	action).fork();
4985	>	}
4986	>	for (Node<K,V> p; (p = advance()) != null;)
4987	>	action.accept(p.val);
4988	>	propagateCompletion();
4989	>	}
4990		}
4991	+	}
4992
4993	<	// Read the keys and values, and put the mappings in the table
4994	<	for (;;) {
4995	<	K key = (K) s.readObject();
4996	<	V value = (V) s.readObject();
4997	<	if (key == null)
4998	<	break;
4999	<	put(key, value);
4993	>	@SuppressWarnings("serial")
4994	>	static final class ForEachEntryTask<K,V>
4995	>	extends BulkTask<K,V,Void> {
4996	>	final Consumer<? super Entry<K,V>> action;
4997	>	ForEachEntryTask
4998	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4999	>	Consumer<? super Entry<K,V>> action) {
5000	>	super(p, b, i, f, t);
5001	>	this.action = action;
5002	>	}
5003	>	public final void compute() {
5004	>	final Consumer<? super Entry<K,V>> action;
5005	>	if ((action = this.action) != null) {
5006	>	for (int i = baseIndex, f, h; batch > 0 &&
5007	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5008	>	addToPendingCount(1);
5009	>	new ForEachEntryTask<K,V>
5010	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5011	>	action).fork();
5012	>	}
5013	>	for (Node<K,V> p; (p = advance()) != null; )
5014	>	action.accept(p);
5015	>	propagateCompletion();
5016	>	}
5017	>	}
5018	>	}
5019	>
5020	>	@SuppressWarnings("serial")
5021	>	static final class ForEachMappingTask<K,V>
5022	>	extends BulkTask<K,V,Void> {
5023	>	final BiConsumer<? super K, ? super V> action;
5024	>	ForEachMappingTask
5025	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5026	>	BiConsumer<? super K,? super V> action) {
5027	>	super(p, b, i, f, t);
5028	>	this.action = action;
5029	>	}
5030	>	public final void compute() {
5031	>	final BiConsumer<? super K, ? super V> action;
5032	>	if ((action = this.action) != null) {
5033	>	for (int i = baseIndex, f, h; batch > 0 &&
5034	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5035	>	addToPendingCount(1);
5036	>	new ForEachMappingTask<K,V>
5037	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5038	>	action).fork();
5039	>	}
5040	>	for (Node<K,V> p; (p = advance()) != null; )
5041	>	action.accept(p.key, p.val);
5042	>	propagateCompletion();
5043	>	}
5044	>	}
5045	>	}
5046	>
5047	>	@SuppressWarnings("serial")
5048	>	static final class ForEachTransformedKeyTask<K,V,U>
5049	>	extends BulkTask<K,V,Void> {
5050	>	final Function<? super K, ? extends U> transformer;
5051	>	final Consumer<? super U> action;
5052	>	ForEachTransformedKeyTask
5053	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5054	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5055	>	super(p, b, i, f, t);
5056	>	this.transformer = transformer; this.action = action;
5057	>	}
5058	>	public final void compute() {
5059	>	final Function<? super K, ? extends U> transformer;
5060	>	final Consumer<? super U> action;
5061	>	if ((transformer = this.transformer) != null &&
5062	>	(action = this.action) != null) {
5063	>	for (int i = baseIndex, f, h; batch > 0 &&
5064	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5065	>	addToPendingCount(1);
5066	>	new ForEachTransformedKeyTask<K,V,U>
5067	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5068	>	transformer, action).fork();
5069	>	}
5070	>	for (Node<K,V> p; (p = advance()) != null; ) {
5071	>	U u;
5072	>	if ((u = transformer.apply(p.key)) != null)
5073	>	action.accept(u);
5074	>	}
5075	>	propagateCompletion();
5076	>	}
5077		}
5078		}
5079	+
5080	+	@SuppressWarnings("serial")
5081	+	static final class ForEachTransformedValueTask<K,V,U>
5082	+	extends BulkTask<K,V,Void> {
5083	+	final Function<? super V, ? extends U> transformer;
5084	+	final Consumer<? super U> action;
5085	+	ForEachTransformedValueTask
5086	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5087	+	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5088	+	super(p, b, i, f, t);
5089	+	this.transformer = transformer; this.action = action;
5090	+	}
5091	+	public final void compute() {
5092	+	final Function<? super V, ? extends U> transformer;
5093	+	final Consumer<? super U> action;
5094	+	if ((transformer = this.transformer) != null &&
5095	+	(action = this.action) != null) {
5096	+	for (int i = baseIndex, f, h; batch > 0 &&
5097	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5098	+	addToPendingCount(1);
5099	+	new ForEachTransformedValueTask<K,V,U>
5100	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5101	+	transformer, action).fork();
5102	+	}
5103	+	for (Node<K,V> p; (p = advance()) != null; ) {
5104	+	U u;
5105	+	if ((u = transformer.apply(p.val)) != null)
5106	+	action.accept(u);
5107	+	}
5108	+	propagateCompletion();
5109	+	}
5110	+	}
5111	+	}
5112	+
5113	+	@SuppressWarnings("serial")
5114	+	static final class ForEachTransformedEntryTask<K,V,U>
5115	+	extends BulkTask<K,V,Void> {
5116	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5117	+	final Consumer<? super U> action;
5118	+	ForEachTransformedEntryTask
5119	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5120	+	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5121	+	super(p, b, i, f, t);
5122	+	this.transformer = transformer; this.action = action;
5123	+	}
5124	+	public final void compute() {
5125	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5126	+	final Consumer<? super U> action;
5127	+	if ((transformer = this.transformer) != null &&
5128	+	(action = this.action) != null) {
5129	+	for (int i = baseIndex, f, h; batch > 0 &&
5130	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5131	+	addToPendingCount(1);
5132	+	new ForEachTransformedEntryTask<K,V,U>
5133	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5134	+	transformer, action).fork();
5135	+	}
5136	+	for (Node<K,V> p; (p = advance()) != null; ) {
5137	+	U u;
5138	+	if ((u = transformer.apply(p)) != null)
5139	+	action.accept(u);
5140	+	}
5141	+	propagateCompletion();
5142	+	}
5143	+	}
5144	+	}
5145	+
5146	+	@SuppressWarnings("serial")
5147	+	static final class ForEachTransformedMappingTask<K,V,U>
5148	+	extends BulkTask<K,V,Void> {
5149	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5150	+	final Consumer<? super U> action;
5151	+	ForEachTransformedMappingTask
5152	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5153	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5154	+	Consumer<? super U> action) {
5155	+	super(p, b, i, f, t);
5156	+	this.transformer = transformer; this.action = action;
5157	+	}
5158	+	public final void compute() {
5159	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5160	+	final Consumer<? super U> action;
5161	+	if ((transformer = this.transformer) != null &&
5162	+	(action = this.action) != null) {
5163	+	for (int i = baseIndex, f, h; batch > 0 &&
5164	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5165	+	addToPendingCount(1);
5166	+	new ForEachTransformedMappingTask<K,V,U>
5167	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5168	+	transformer, action).fork();
5169	+	}
5170	+	for (Node<K,V> p; (p = advance()) != null; ) {
5171	+	U u;
5172	+	if ((u = transformer.apply(p.key, p.val)) != null)
5173	+	action.accept(u);
5174	+	}
5175	+	propagateCompletion();
5176	+	}
5177	+	}
5178	+	}
5179	+
5180	+	@SuppressWarnings("serial")
5181	+	static final class SearchKeysTask<K,V,U>
5182	+	extends BulkTask<K,V,U> {
5183	+	final Function<? super K, ? extends U> searchFunction;
5184	+	final AtomicReference<U> result;
5185	+	SearchKeysTask
5186	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5187	+	Function<? super K, ? extends U> searchFunction,
5188	+	AtomicReference<U> result) {
5189	+	super(p, b, i, f, t);
5190	+	this.searchFunction = searchFunction; this.result = result;
5191	+	}
5192	+	public final U getRawResult() { return result.get(); }
5193	+	public final void compute() {
5194	+	final Function<? super K, ? extends U> searchFunction;
5195	+	final AtomicReference<U> result;
5196	+	if ((searchFunction = this.searchFunction) != null &&
5197	+	(result = this.result) != null) {
5198	+	for (int i = baseIndex, f, h; batch > 0 &&
5199	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5200	+	if (result.get() != null)
5201	+	return;
5202	+	addToPendingCount(1);
5203	+	new SearchKeysTask<K,V,U>
5204	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5205	+	searchFunction, result).fork();
5206	+	}
5207	+	while (result.get() == null) {
5208	+	U u;
5209	+	Node<K,V> p;
5210	+	if ((p = advance()) == null) {
5211	+	propagateCompletion();
5212	+	break;
5213	+	}
5214	+	if ((u = searchFunction.apply(p.key)) != null) {
5215	+	if (result.compareAndSet(null, u))
5216	+	quietlyCompleteRoot();
5217	+	break;
5218	+	}
5219	+	}
5220	+	}
5221	+	}
5222	+	}
5223	+
5224	+	@SuppressWarnings("serial")
5225	+	static final class SearchValuesTask<K,V,U>
5226	+	extends BulkTask<K,V,U> {
5227	+	final Function<? super V, ? extends U> searchFunction;
5228	+	final AtomicReference<U> result;
5229	+	SearchValuesTask
5230	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5231	+	Function<? super V, ? extends U> searchFunction,
5232	+	AtomicReference<U> result) {
5233	+	super(p, b, i, f, t);
5234	+	this.searchFunction = searchFunction; this.result = result;
5235	+	}
5236	+	public final U getRawResult() { return result.get(); }
5237	+	public final void compute() {
5238	+	final Function<? super V, ? extends U> searchFunction;
5239	+	final AtomicReference<U> result;
5240	+	if ((searchFunction = this.searchFunction) != null &&
5241	+	(result = this.result) != null) {
5242	+	for (int i = baseIndex, f, h; batch > 0 &&
5243	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5244	+	if (result.get() != null)
5245	+	return;
5246	+	addToPendingCount(1);
5247	+	new SearchValuesTask<K,V,U>
5248	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5249	+	searchFunction, result).fork();
5250	+	}
5251	+	while (result.get() == null) {
5252	+	U u;
5253	+	Node<K,V> p;
5254	+	if ((p = advance()) == null) {
5255	+	propagateCompletion();
5256	+	break;
5257	+	}
5258	+	if ((u = searchFunction.apply(p.val)) != null) {
5259	+	if (result.compareAndSet(null, u))
5260	+	quietlyCompleteRoot();
5261	+	break;
5262	+	}
5263	+	}
5264	+	}
5265	+	}
5266	+	}
5267	+
5268	+	@SuppressWarnings("serial")
5269	+	static final class SearchEntriesTask<K,V,U>
5270	+	extends BulkTask<K,V,U> {
5271	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5272	+	final AtomicReference<U> result;
5273	+	SearchEntriesTask
5274	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5275	+	Function<Entry<K,V>, ? extends U> searchFunction,
5276	+	AtomicReference<U> result) {
5277	+	super(p, b, i, f, t);
5278	+	this.searchFunction = searchFunction; this.result = result;
5279	+	}
5280	+	public final U getRawResult() { return result.get(); }
5281	+	public final void compute() {
5282	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5283	+	final AtomicReference<U> result;
5284	+	if ((searchFunction = this.searchFunction) != null &&
5285	+	(result = this.result) != null) {
5286	+	for (int i = baseIndex, f, h; batch > 0 &&
5287	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5288	+	if (result.get() != null)
5289	+	return;
5290	+	addToPendingCount(1);
5291	+	new SearchEntriesTask<K,V,U>
5292	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5293	+	searchFunction, result).fork();
5294	+	}
5295	+	while (result.get() == null) {
5296	+	U u;
5297	+	Node<K,V> p;
5298	+	if ((p = advance()) == null) {
5299	+	propagateCompletion();
5300	+	break;
5301	+	}
5302	+	if ((u = searchFunction.apply(p)) != null) {
5303	+	if (result.compareAndSet(null, u))
5304	+	quietlyCompleteRoot();
5305	+	return;
5306	+	}
5307	+	}
5308	+	}
5309	+	}
5310	+	}
5311	+
5312	+	@SuppressWarnings("serial")
5313	+	static final class SearchMappingsTask<K,V,U>
5314	+	extends BulkTask<K,V,U> {
5315	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5316	+	final AtomicReference<U> result;
5317	+	SearchMappingsTask
5318	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5319	+	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5320	+	AtomicReference<U> result) {
5321	+	super(p, b, i, f, t);
5322	+	this.searchFunction = searchFunction; this.result = result;
5323	+	}
5324	+	public final U getRawResult() { return result.get(); }
5325	+	public final void compute() {
5326	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5327	+	final AtomicReference<U> result;
5328	+	if ((searchFunction = this.searchFunction) != null &&
5329	+	(result = this.result) != null) {
5330	+	for (int i = baseIndex, f, h; batch > 0 &&
5331	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5332	+	if (result.get() != null)
5333	+	return;
5334	+	addToPendingCount(1);
5335	+	new SearchMappingsTask<K,V,U>
5336	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5337	+	searchFunction, result).fork();
5338	+	}
5339	+	while (result.get() == null) {
5340	+	U u;
5341	+	Node<K,V> p;
5342	+	if ((p = advance()) == null) {
5343	+	propagateCompletion();
5344	+	break;
5345	+	}
5346	+	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5347	+	if (result.compareAndSet(null, u))
5348	+	quietlyCompleteRoot();
5349	+	break;
5350	+	}
5351	+	}
5352	+	}
5353	+	}
5354	+	}
5355	+
5356	+	@SuppressWarnings("serial")
5357	+	static final class ReduceKeysTask<K,V>
5358	+	extends BulkTask<K,V,K> {
5359	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5360	+	K result;
5361	+	ReduceKeysTask<K,V> rights, nextRight;
5362	+	ReduceKeysTask
5363	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5364	+	ReduceKeysTask<K,V> nextRight,
5365	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5366	+	super(p, b, i, f, t); this.nextRight = nextRight;
5367	+	this.reducer = reducer;
5368	+	}
5369	+	public final K getRawResult() { return result; }
5370	+	public final void compute() {
5371	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5372	+	if ((reducer = this.reducer) != null) {
5373	+	for (int i = baseIndex, f, h; batch > 0 &&
5374	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5375	+	addToPendingCount(1);
5376	+	(rights = new ReduceKeysTask<K,V>
5377	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5378	+	rights, reducer)).fork();
5379	+	}
5380	+	K r = null;
5381	+	for (Node<K,V> p; (p = advance()) != null; ) {
5382	+	K u = p.key;
5383	+	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5384	+	}
5385	+	result = r;
5386	+	CountedCompleter<?> c;
5387	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5388	+	@SuppressWarnings("unchecked")
5389	+	ReduceKeysTask<K,V>
5390	+	t = (ReduceKeysTask<K,V>)c,
5391	+	s = t.rights;
5392	+	while (s != null) {
5393	+	K tr, sr;
5394	+	if ((sr = s.result) != null)
5395	+	t.result = (((tr = t.result) == null) ? sr :
5396	+	reducer.apply(tr, sr));
5397	+	s = t.rights = s.nextRight;
5398	+	}
5399	+	}
5400	+	}
5401	+	}
5402	+	}
5403	+
5404	+	@SuppressWarnings("serial")
5405	+	static final class ReduceValuesTask<K,V>
5406	+	extends BulkTask<K,V,V> {
5407	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5408	+	V result;
5409	+	ReduceValuesTask<K,V> rights, nextRight;
5410	+	ReduceValuesTask
5411	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5412	+	ReduceValuesTask<K,V> nextRight,
5413	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5414	+	super(p, b, i, f, t); this.nextRight = nextRight;
5415	+	this.reducer = reducer;
5416	+	}
5417	+	public final V getRawResult() { return result; }
5418	+	public final void compute() {
5419	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5420	+	if ((reducer = this.reducer) != null) {
5421	+	for (int i = baseIndex, f, h; batch > 0 &&
5422	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5423	+	addToPendingCount(1);
5424	+	(rights = new ReduceValuesTask<K,V>
5425	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5426	+	rights, reducer)).fork();
5427	+	}
5428	+	V r = null;
5429	+	for (Node<K,V> p; (p = advance()) != null; ) {
5430	+	V v = p.val;
5431	+	r = (r == null) ? v : reducer.apply(r, v);
5432	+	}
5433	+	result = r;
5434	+	CountedCompleter<?> c;
5435	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5436	+	@SuppressWarnings("unchecked")
5437	+	ReduceValuesTask<K,V>
5438	+	t = (ReduceValuesTask<K,V>)c,
5439	+	s = t.rights;
5440	+	while (s != null) {
5441	+	V tr, sr;
5442	+	if ((sr = s.result) != null)
5443	+	t.result = (((tr = t.result) == null) ? sr :
5444	+	reducer.apply(tr, sr));
5445	+	s = t.rights = s.nextRight;
5446	+	}
5447	+	}
5448	+	}
5449	+	}
5450	+	}
5451	+
5452	+	@SuppressWarnings("serial")
5453	+	static final class ReduceEntriesTask<K,V>
5454	+	extends BulkTask<K,V,Map.Entry<K,V>> {
5455	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5456	+	Map.Entry<K,V> result;
5457	+	ReduceEntriesTask<K,V> rights, nextRight;
5458	+	ReduceEntriesTask
5459	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5460	+	ReduceEntriesTask<K,V> nextRight,
5461	+	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5462	+	super(p, b, i, f, t); this.nextRight = nextRight;
5463	+	this.reducer = reducer;
5464	+	}
5465	+	public final Map.Entry<K,V> getRawResult() { return result; }
5466	+	public final void compute() {
5467	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5468	+	if ((reducer = this.reducer) != null) {
5469	+	for (int i = baseIndex, f, h; batch > 0 &&
5470	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5471	+	addToPendingCount(1);
5472	+	(rights = new ReduceEntriesTask<K,V>
5473	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5474	+	rights, reducer)).fork();
5475	+	}
5476	+	Map.Entry<K,V> r = null;
5477	+	for (Node<K,V> p; (p = advance()) != null; )
5478	+	r = (r == null) ? p : reducer.apply(r, p);
5479	+	result = r;
5480	+	CountedCompleter<?> c;
5481	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5482	+	@SuppressWarnings("unchecked")
5483	+	ReduceEntriesTask<K,V>
5484	+	t = (ReduceEntriesTask<K,V>)c,
5485	+	s = t.rights;
5486	+	while (s != null) {
5487	+	Map.Entry<K,V> tr, sr;
5488	+	if ((sr = s.result) != null)
5489	+	t.result = (((tr = t.result) == null) ? sr :
5490	+	reducer.apply(tr, sr));
5491	+	s = t.rights = s.nextRight;
5492	+	}
5493	+	}
5494	+	}
5495	+	}
5496	+	}
5497	+
5498	+	@SuppressWarnings("serial")
5499	+	static final class MapReduceKeysTask<K,V,U>
5500	+	extends BulkTask<K,V,U> {
5501	+	final Function<? super K, ? extends U> transformer;
5502	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5503	+	U result;
5504	+	MapReduceKeysTask<K,V,U> rights, nextRight;
5505	+	MapReduceKeysTask
5506	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5507	+	MapReduceKeysTask<K,V,U> nextRight,
5508	+	Function<? super K, ? extends U> transformer,
5509	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5510	+	super(p, b, i, f, t); this.nextRight = nextRight;
5511	+	this.transformer = transformer;
5512	+	this.reducer = reducer;
5513	+	}
5514	+	public final U getRawResult() { return result; }
5515	+	public final void compute() {
5516	+	final Function<? super K, ? extends U> transformer;
5517	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5518	+	if ((transformer = this.transformer) != null &&
5519	+	(reducer = this.reducer) != null) {
5520	+	for (int i = baseIndex, f, h; batch > 0 &&
5521	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5522	+	addToPendingCount(1);
5523	+	(rights = new MapReduceKeysTask<K,V,U>
5524	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5525	+	rights, transformer, reducer)).fork();
5526	+	}
5527	+	U r = null;
5528	+	for (Node<K,V> p; (p = advance()) != null; ) {
5529	+	U u;
5530	+	if ((u = transformer.apply(p.key)) != null)
5531	+	r = (r == null) ? u : reducer.apply(r, u);
5532	+	}
5533	+	result = r;
5534	+	CountedCompleter<?> c;
5535	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5536	+	@SuppressWarnings("unchecked")
5537	+	MapReduceKeysTask<K,V,U>
5538	+	t = (MapReduceKeysTask<K,V,U>)c,
5539	+	s = t.rights;
5540	+	while (s != null) {
5541	+	U tr, sr;
5542	+	if ((sr = s.result) != null)
5543	+	t.result = (((tr = t.result) == null) ? sr :
5544	+	reducer.apply(tr, sr));
5545	+	s = t.rights = s.nextRight;
5546	+	}
5547	+	}
5548	+	}
5549	+	}
5550	+	}
5551	+
5552	+	@SuppressWarnings("serial")
5553	+	static final class MapReduceValuesTask<K,V,U>
5554	+	extends BulkTask<K,V,U> {
5555	+	final Function<? super V, ? extends U> transformer;
5556	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5557	+	U result;
5558	+	MapReduceValuesTask<K,V,U> rights, nextRight;
5559	+	MapReduceValuesTask
5560	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5561	+	MapReduceValuesTask<K,V,U> nextRight,
5562	+	Function<? super V, ? extends U> transformer,
5563	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5564	+	super(p, b, i, f, t); this.nextRight = nextRight;
5565	+	this.transformer = transformer;
5566	+	this.reducer = reducer;
5567	+	}
5568	+	public final U getRawResult() { return result; }
5569	+	public final void compute() {
5570	+	final Function<? super V, ? extends U> transformer;
5571	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5572	+	if ((transformer = this.transformer) != null &&
5573	+	(reducer = this.reducer) != null) {
5574	+	for (int i = baseIndex, f, h; batch > 0 &&
5575	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5576	+	addToPendingCount(1);
5577	+	(rights = new MapReduceValuesTask<K,V,U>
5578	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5579	+	rights, transformer, reducer)).fork();
5580	+	}
5581	+	U r = null;
5582	+	for (Node<K,V> p; (p = advance()) != null; ) {
5583	+	U u;
5584	+	if ((u = transformer.apply(p.val)) != null)
5585	+	r = (r == null) ? u : reducer.apply(r, u);
5586	+	}
5587	+	result = r;
5588	+	CountedCompleter<?> c;
5589	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5590	+	@SuppressWarnings("unchecked")
5591	+	MapReduceValuesTask<K,V,U>
5592	+	t = (MapReduceValuesTask<K,V,U>)c,
5593	+	s = t.rights;
5594	+	while (s != null) {
5595	+	U tr, sr;
5596	+	if ((sr = s.result) != null)
5597	+	t.result = (((tr = t.result) == null) ? sr :
5598	+	reducer.apply(tr, sr));
5599	+	s = t.rights = s.nextRight;
5600	+	}
5601	+	}
5602	+	}
5603	+	}
5604	+	}
5605	+
5606	+	@SuppressWarnings("serial")
5607	+	static final class MapReduceEntriesTask<K,V,U>
5608	+	extends BulkTask<K,V,U> {
5609	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5610	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5611	+	U result;
5612	+	MapReduceEntriesTask<K,V,U> rights, nextRight;
5613	+	MapReduceEntriesTask
5614	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5615	+	MapReduceEntriesTask<K,V,U> nextRight,
5616	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5617	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5618	+	super(p, b, i, f, t); this.nextRight = nextRight;
5619	+	this.transformer = transformer;
5620	+	this.reducer = reducer;
5621	+	}
5622	+	public final U getRawResult() { return result; }
5623	+	public final void compute() {
5624	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5625	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5626	+	if ((transformer = this.transformer) != null &&
5627	+	(reducer = this.reducer) != null) {
5628	+	for (int i = baseIndex, f, h; batch > 0 &&
5629	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5630	+	addToPendingCount(1);
5631	+	(rights = new MapReduceEntriesTask<K,V,U>
5632	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5633	+	rights, transformer, reducer)).fork();
5634	+	}
5635	+	U r = null;
5636	+	for (Node<K,V> p; (p = advance()) != null; ) {
5637	+	U u;
5638	+	if ((u = transformer.apply(p)) != null)
5639	+	r = (r == null) ? u : reducer.apply(r, u);
5640	+	}
5641	+	result = r;
5642	+	CountedCompleter<?> c;
5643	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5644	+	@SuppressWarnings("unchecked")
5645	+	MapReduceEntriesTask<K,V,U>
5646	+	t = (MapReduceEntriesTask<K,V,U>)c,
5647	+	s = t.rights;
5648	+	while (s != null) {
5649	+	U tr, sr;
5650	+	if ((sr = s.result) != null)
5651	+	t.result = (((tr = t.result) == null) ? sr :
5652	+	reducer.apply(tr, sr));
5653	+	s = t.rights = s.nextRight;
5654	+	}
5655	+	}
5656	+	}
5657	+	}
5658	+	}
5659	+
5660	+	@SuppressWarnings("serial")
5661	+	static final class MapReduceMappingsTask<K,V,U>
5662	+	extends BulkTask<K,V,U> {
5663	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5664	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5665	+	U result;
5666	+	MapReduceMappingsTask<K,V,U> rights, nextRight;
5667	+	MapReduceMappingsTask
5668	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5669	+	MapReduceMappingsTask<K,V,U> nextRight,
5670	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5671	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5672	+	super(p, b, i, f, t); this.nextRight = nextRight;
5673	+	this.transformer = transformer;
5674	+	this.reducer = reducer;
5675	+	}
5676	+	public final U getRawResult() { return result; }
5677	+	public final void compute() {
5678	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5679	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5680	+	if ((transformer = this.transformer) != null &&
5681	+	(reducer = this.reducer) != null) {
5682	+	for (int i = baseIndex, f, h; batch > 0 &&
5683	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5684	+	addToPendingCount(1);
5685	+	(rights = new MapReduceMappingsTask<K,V,U>
5686	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5687	+	rights, transformer, reducer)).fork();
5688	+	}
5689	+	U r = null;
5690	+	for (Node<K,V> p; (p = advance()) != null; ) {
5691	+	U u;
5692	+	if ((u = transformer.apply(p.key, p.val)) != null)
5693	+	r = (r == null) ? u : reducer.apply(r, u);
5694	+	}
5695	+	result = r;
5696	+	CountedCompleter<?> c;
5697	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5698	+	@SuppressWarnings("unchecked")
5699	+	MapReduceMappingsTask<K,V,U>
5700	+	t = (MapReduceMappingsTask<K,V,U>)c,
5701	+	s = t.rights;
5702	+	while (s != null) {
5703	+	U tr, sr;
5704	+	if ((sr = s.result) != null)
5705	+	t.result = (((tr = t.result) == null) ? sr :
5706	+	reducer.apply(tr, sr));
5707	+	s = t.rights = s.nextRight;
5708	+	}
5709	+	}
5710	+	}
5711	+	}
5712	+	}
5713	+
5714	+	@SuppressWarnings("serial")
5715	+	static final class MapReduceKeysToDoubleTask<K,V>
5716	+	extends BulkTask<K,V,Double> {
5717	+	final ToDoubleFunction<? super K> transformer;
5718	+	final DoubleBinaryOperator reducer;
5719	+	final double basis;
5720	+	double result;
5721	+	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5722	+	MapReduceKeysToDoubleTask
5723	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5724	+	MapReduceKeysToDoubleTask<K,V> nextRight,
5725	+	ToDoubleFunction<? super K> transformer,
5726	+	double basis,
5727	+	DoubleBinaryOperator reducer) {
5728	+	super(p, b, i, f, t); this.nextRight = nextRight;
5729	+	this.transformer = transformer;
5730	+	this.basis = basis; this.reducer = reducer;
5731	+	}
5732	+	public final Double getRawResult() { return result; }
5733	+	public final void compute() {
5734	+	final ToDoubleFunction<? super K> transformer;
5735	+	final DoubleBinaryOperator reducer;
5736	+	if ((transformer = this.transformer) != null &&
5737	+	(reducer = this.reducer) != null) {
5738	+	double r = this.basis;
5739	+	for (int i = baseIndex, f, h; batch > 0 &&
5740	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5741	+	addToPendingCount(1);
5742	+	(rights = new MapReduceKeysToDoubleTask<K,V>
5743	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5744	+	rights, transformer, r, reducer)).fork();
5745	+	}
5746	+	for (Node<K,V> p; (p = advance()) != null; )
5747	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5748	+	result = r;
5749	+	CountedCompleter<?> c;
5750	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5751	+	@SuppressWarnings("unchecked")
5752	+	MapReduceKeysToDoubleTask<K,V>
5753	+	t = (MapReduceKeysToDoubleTask<K,V>)c,
5754	+	s = t.rights;
5755	+	while (s != null) {
5756	+	t.result = reducer.applyAsDouble(t.result, s.result);
5757	+	s = t.rights = s.nextRight;
5758	+	}
5759	+	}
5760	+	}
5761	+	}
5762	+	}
5763	+
5764	+	@SuppressWarnings("serial")
5765	+	static final class MapReduceValuesToDoubleTask<K,V>
5766	+	extends BulkTask<K,V,Double> {
5767	+	final ToDoubleFunction<? super V> transformer;
5768	+	final DoubleBinaryOperator reducer;
5769	+	final double basis;
5770	+	double result;
5771	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5772	+	MapReduceValuesToDoubleTask
5773	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5774	+	MapReduceValuesToDoubleTask<K,V> nextRight,
5775	+	ToDoubleFunction<? super V> transformer,
5776	+	double basis,
5777	+	DoubleBinaryOperator reducer) {
5778	+	super(p, b, i, f, t); this.nextRight = nextRight;
5779	+	this.transformer = transformer;
5780	+	this.basis = basis; this.reducer = reducer;
5781	+	}
5782	+	public final Double getRawResult() { return result; }
5783	+	public final void compute() {
5784	+	final ToDoubleFunction<? super V> transformer;
5785	+	final DoubleBinaryOperator reducer;
5786	+	if ((transformer = this.transformer) != null &&
5787	+	(reducer = this.reducer) != null) {
5788	+	double r = this.basis;
5789	+	for (int i = baseIndex, f, h; batch > 0 &&
5790	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5791	+	addToPendingCount(1);
5792	+	(rights = new MapReduceValuesToDoubleTask<K,V>
5793	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5794	+	rights, transformer, r, reducer)).fork();
5795	+	}
5796	+	for (Node<K,V> p; (p = advance()) != null; )
5797	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5798	+	result = r;
5799	+	CountedCompleter<?> c;
5800	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5801	+	@SuppressWarnings("unchecked")
5802	+	MapReduceValuesToDoubleTask<K,V>
5803	+	t = (MapReduceValuesToDoubleTask<K,V>)c,
5804	+	s = t.rights;
5805	+	while (s != null) {
5806	+	t.result = reducer.applyAsDouble(t.result, s.result);
5807	+	s = t.rights = s.nextRight;
5808	+	}
5809	+	}
5810	+	}
5811	+	}
5812	+	}
5813	+
5814	+	@SuppressWarnings("serial")
5815	+	static final class MapReduceEntriesToDoubleTask<K,V>
5816	+	extends BulkTask<K,V,Double> {
5817	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5818	+	final DoubleBinaryOperator reducer;
5819	+	final double basis;
5820	+	double result;
5821	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5822	+	MapReduceEntriesToDoubleTask
5823	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5824	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
5825	+	ToDoubleFunction<Map.Entry<K,V>> transformer,
5826	+	double basis,
5827	+	DoubleBinaryOperator reducer) {
5828	+	super(p, b, i, f, t); this.nextRight = nextRight;
5829	+	this.transformer = transformer;
5830	+	this.basis = basis; this.reducer = reducer;
5831	+	}
5832	+	public final Double getRawResult() { return result; }
5833	+	public final void compute() {
5834	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5835	+	final DoubleBinaryOperator reducer;
5836	+	if ((transformer = this.transformer) != null &&
5837	+	(reducer = this.reducer) != null) {
5838	+	double r = this.basis;
5839	+	for (int i = baseIndex, f, h; batch > 0 &&
5840	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5841	+	addToPendingCount(1);
5842	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
5843	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5844	+	rights, transformer, r, reducer)).fork();
5845	+	}
5846	+	for (Node<K,V> p; (p = advance()) != null; )
5847	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5848	+	result = r;
5849	+	CountedCompleter<?> c;
5850	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5851	+	@SuppressWarnings("unchecked")
5852	+	MapReduceEntriesToDoubleTask<K,V>
5853	+	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5854	+	s = t.rights;
5855	+	while (s != null) {
5856	+	t.result = reducer.applyAsDouble(t.result, s.result);
5857	+	s = t.rights = s.nextRight;
5858	+	}
5859	+	}
5860	+	}
5861	+	}
5862	+	}
5863	+
5864	+	@SuppressWarnings("serial")
5865	+	static final class MapReduceMappingsToDoubleTask<K,V>
5866	+	extends BulkTask<K,V,Double> {
5867	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5868	+	final DoubleBinaryOperator reducer;
5869	+	final double basis;
5870	+	double result;
5871	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5872	+	MapReduceMappingsToDoubleTask
5873	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5874	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
5875	+	ToDoubleBiFunction<? super K, ? super V> transformer,
5876	+	double basis,
5877	+	DoubleBinaryOperator reducer) {
5878	+	super(p, b, i, f, t); this.nextRight = nextRight;
5879	+	this.transformer = transformer;
5880	+	this.basis = basis; this.reducer = reducer;
5881	+	}
5882	+	public final Double getRawResult() { return result; }
5883	+	public final void compute() {
5884	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5885	+	final DoubleBinaryOperator reducer;
5886	+	if ((transformer = this.transformer) != null &&
5887	+	(reducer = this.reducer) != null) {
5888	+	double r = this.basis;
5889	+	for (int i = baseIndex, f, h; batch > 0 &&
5890	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5891	+	addToPendingCount(1);
5892	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
5893	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5894	+	rights, transformer, r, reducer)).fork();
5895	+	}
5896	+	for (Node<K,V> p; (p = advance()) != null; )
5897	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5898	+	result = r;
5899	+	CountedCompleter<?> c;
5900	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5901	+	@SuppressWarnings("unchecked")
5902	+	MapReduceMappingsToDoubleTask<K,V>
5903	+	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5904	+	s = t.rights;
5905	+	while (s != null) {
5906	+	t.result = reducer.applyAsDouble(t.result, s.result);
5907	+	s = t.rights = s.nextRight;
5908	+	}
5909	+	}
5910	+	}
5911	+	}
5912	+	}
5913	+
5914	+	@SuppressWarnings("serial")
5915	+	static final class MapReduceKeysToLongTask<K,V>
5916	+	extends BulkTask<K,V,Long> {
5917	+	final ToLongFunction<? super K> transformer;
5918	+	final LongBinaryOperator reducer;
5919	+	final long basis;
5920	+	long result;
5921	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
5922	+	MapReduceKeysToLongTask
5923	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5924	+	MapReduceKeysToLongTask<K,V> nextRight,
5925	+	ToLongFunction<? super K> transformer,
5926	+	long basis,
5927	+	LongBinaryOperator reducer) {
5928	+	super(p, b, i, f, t); this.nextRight = nextRight;
5929	+	this.transformer = transformer;
5930	+	this.basis = basis; this.reducer = reducer;
5931	+	}
5932	+	public final Long getRawResult() { return result; }
5933	+	public final void compute() {
5934	+	final ToLongFunction<? super K> transformer;
5935	+	final LongBinaryOperator reducer;
5936	+	if ((transformer = this.transformer) != null &&
5937	+	(reducer = this.reducer) != null) {
5938	+	long r = this.basis;
5939	+	for (int i = baseIndex, f, h; batch > 0 &&
5940	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5941	+	addToPendingCount(1);
5942	+	(rights = new MapReduceKeysToLongTask<K,V>
5943	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5944	+	rights, transformer, r, reducer)).fork();
5945	+	}
5946	+	for (Node<K,V> p; (p = advance()) != null; )
5947	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5948	+	result = r;
5949	+	CountedCompleter<?> c;
5950	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5951	+	@SuppressWarnings("unchecked")
5952	+	MapReduceKeysToLongTask<K,V>
5953	+	t = (MapReduceKeysToLongTask<K,V>)c,
5954	+	s = t.rights;
5955	+	while (s != null) {
5956	+	t.result = reducer.applyAsLong(t.result, s.result);
5957	+	s = t.rights = s.nextRight;
5958	+	}
5959	+	}
5960	+	}
5961	+	}
5962	+	}
5963	+
5964	+	@SuppressWarnings("serial")
5965	+	static final class MapReduceValuesToLongTask<K,V>
5966	+	extends BulkTask<K,V,Long> {
5967	+	final ToLongFunction<? super V> transformer;
5968	+	final LongBinaryOperator reducer;
5969	+	final long basis;
5970	+	long result;
5971	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
5972	+	MapReduceValuesToLongTask
5973	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5974	+	MapReduceValuesToLongTask<K,V> nextRight,
5975	+	ToLongFunction<? super V> transformer,
5976	+	long basis,
5977	+	LongBinaryOperator reducer) {
5978	+	super(p, b, i, f, t); this.nextRight = nextRight;
5979	+	this.transformer = transformer;
5980	+	this.basis = basis; this.reducer = reducer;
5981	+	}
5982	+	public final Long getRawResult() { return result; }
5983	+	public final void compute() {
5984	+	final ToLongFunction<? super V> transformer;
5985	+	final LongBinaryOperator reducer;
5986	+	if ((transformer = this.transformer) != null &&
5987	+	(reducer = this.reducer) != null) {
5988	+	long r = this.basis;
5989	+	for (int i = baseIndex, f, h; batch > 0 &&
5990	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5991	+	addToPendingCount(1);
5992	+	(rights = new MapReduceValuesToLongTask<K,V>
5993	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5994	+	rights, transformer, r, reducer)).fork();
5995	+	}
5996	+	for (Node<K,V> p; (p = advance()) != null; )
5997	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5998	+	result = r;
5999	+	CountedCompleter<?> c;
6000	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6001	+	@SuppressWarnings("unchecked")
6002	+	MapReduceValuesToLongTask<K,V>
6003	+	t = (MapReduceValuesToLongTask<K,V>)c,
6004	+	s = t.rights;
6005	+	while (s != null) {
6006	+	t.result = reducer.applyAsLong(t.result, s.result);
6007	+	s = t.rights = s.nextRight;
6008	+	}
6009	+	}
6010	+	}
6011	+	}
6012	+	}
6013	+
6014	+	@SuppressWarnings("serial")
6015	+	static final class MapReduceEntriesToLongTask<K,V>
6016	+	extends BulkTask<K,V,Long> {
6017	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6018	+	final LongBinaryOperator reducer;
6019	+	final long basis;
6020	+	long result;
6021	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6022	+	MapReduceEntriesToLongTask
6023	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6024	+	MapReduceEntriesToLongTask<K,V> nextRight,
6025	+	ToLongFunction<Map.Entry<K,V>> transformer,
6026	+	long basis,
6027	+	LongBinaryOperator reducer) {
6028	+	super(p, b, i, f, t); this.nextRight = nextRight;
6029	+	this.transformer = transformer;
6030	+	this.basis = basis; this.reducer = reducer;
6031	+	}
6032	+	public final Long getRawResult() { return result; }
6033	+	public final void compute() {
6034	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6035	+	final LongBinaryOperator reducer;
6036	+	if ((transformer = this.transformer) != null &&
6037	+	(reducer = this.reducer) != null) {
6038	+	long r = this.basis;
6039	+	for (int i = baseIndex, f, h; batch > 0 &&
6040	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6041	+	addToPendingCount(1);
6042	+	(rights = new MapReduceEntriesToLongTask<K,V>
6043	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6044	+	rights, transformer, r, reducer)).fork();
6045	+	}
6046	+	for (Node<K,V> p; (p = advance()) != null; )
6047	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6048	+	result = r;
6049	+	CountedCompleter<?> c;
6050	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6051	+	@SuppressWarnings("unchecked")
6052	+	MapReduceEntriesToLongTask<K,V>
6053	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6054	+	s = t.rights;
6055	+	while (s != null) {
6056	+	t.result = reducer.applyAsLong(t.result, s.result);
6057	+	s = t.rights = s.nextRight;
6058	+	}
6059	+	}
6060	+	}
6061	+	}
6062	+	}
6063	+
6064	+	@SuppressWarnings("serial")
6065	+	static final class MapReduceMappingsToLongTask<K,V>
6066	+	extends BulkTask<K,V,Long> {
6067	+	final ToLongBiFunction<? super K, ? super V> transformer;
6068	+	final LongBinaryOperator reducer;
6069	+	final long basis;
6070	+	long result;
6071	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6072	+	MapReduceMappingsToLongTask
6073	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6074	+	MapReduceMappingsToLongTask<K,V> nextRight,
6075	+	ToLongBiFunction<? super K, ? super V> transformer,
6076	+	long basis,
6077	+	LongBinaryOperator reducer) {
6078	+	super(p, b, i, f, t); this.nextRight = nextRight;
6079	+	this.transformer = transformer;
6080	+	this.basis = basis; this.reducer = reducer;
6081	+	}
6082	+	public final Long getRawResult() { return result; }
6083	+	public final void compute() {
6084	+	final ToLongBiFunction<? super K, ? super V> transformer;
6085	+	final LongBinaryOperator reducer;
6086	+	if ((transformer = this.transformer) != null &&
6087	+	(reducer = this.reducer) != null) {
6088	+	long r = this.basis;
6089	+	for (int i = baseIndex, f, h; batch > 0 &&
6090	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6091	+	addToPendingCount(1);
6092	+	(rights = new MapReduceMappingsToLongTask<K,V>
6093	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6094	+	rights, transformer, r, reducer)).fork();
6095	+	}
6096	+	for (Node<K,V> p; (p = advance()) != null; )
6097	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6098	+	result = r;
6099	+	CountedCompleter<?> c;
6100	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6101	+	@SuppressWarnings("unchecked")
6102	+	MapReduceMappingsToLongTask<K,V>
6103	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6104	+	s = t.rights;
6105	+	while (s != null) {
6106	+	t.result = reducer.applyAsLong(t.result, s.result);
6107	+	s = t.rights = s.nextRight;
6108	+	}
6109	+	}
6110	+	}
6111	+	}
6112	+	}
6113	+
6114	+	@SuppressWarnings("serial")
6115	+	static final class MapReduceKeysToIntTask<K,V>
6116	+	extends BulkTask<K,V,Integer> {
6117	+	final ToIntFunction<? super K> transformer;
6118	+	final IntBinaryOperator reducer;
6119	+	final int basis;
6120	+	int result;
6121	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6122	+	MapReduceKeysToIntTask
6123	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6124	+	MapReduceKeysToIntTask<K,V> nextRight,
6125	+	ToIntFunction<? super K> transformer,
6126	+	int basis,
6127	+	IntBinaryOperator reducer) {
6128	+	super(p, b, i, f, t); this.nextRight = nextRight;
6129	+	this.transformer = transformer;
6130	+	this.basis = basis; this.reducer = reducer;
6131	+	}
6132	+	public final Integer getRawResult() { return result; }
6133	+	public final void compute() {
6134	+	final ToIntFunction<? super K> transformer;
6135	+	final IntBinaryOperator reducer;
6136	+	if ((transformer = this.transformer) != null &&
6137	+	(reducer = this.reducer) != null) {
6138	+	int r = this.basis;
6139	+	for (int i = baseIndex, f, h; batch > 0 &&
6140	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6141	+	addToPendingCount(1);
6142	+	(rights = new MapReduceKeysToIntTask<K,V>
6143	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6144	+	rights, transformer, r, reducer)).fork();
6145	+	}
6146	+	for (Node<K,V> p; (p = advance()) != null; )
6147	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6148	+	result = r;
6149	+	CountedCompleter<?> c;
6150	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6151	+	@SuppressWarnings("unchecked")
6152	+	MapReduceKeysToIntTask<K,V>
6153	+	t = (MapReduceKeysToIntTask<K,V>)c,
6154	+	s = t.rights;
6155	+	while (s != null) {
6156	+	t.result = reducer.applyAsInt(t.result, s.result);
6157	+	s = t.rights = s.nextRight;
6158	+	}
6159	+	}
6160	+	}
6161	+	}
6162	+	}
6163	+
6164	+	@SuppressWarnings("serial")
6165	+	static final class MapReduceValuesToIntTask<K,V>
6166	+	extends BulkTask<K,V,Integer> {
6167	+	final ToIntFunction<? super V> transformer;
6168	+	final IntBinaryOperator reducer;
6169	+	final int basis;
6170	+	int result;
6171	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6172	+	MapReduceValuesToIntTask
6173	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6174	+	MapReduceValuesToIntTask<K,V> nextRight,
6175	+	ToIntFunction<? super V> transformer,
6176	+	int basis,
6177	+	IntBinaryOperator reducer) {
6178	+	super(p, b, i, f, t); this.nextRight = nextRight;
6179	+	this.transformer = transformer;
6180	+	this.basis = basis; this.reducer = reducer;
6181	+	}
6182	+	public final Integer getRawResult() { return result; }
6183	+	public final void compute() {
6184	+	final ToIntFunction<? super V> transformer;
6185	+	final IntBinaryOperator reducer;
6186	+	if ((transformer = this.transformer) != null &&
6187	+	(reducer = this.reducer) != null) {
6188	+	int r = this.basis;
6189	+	for (int i = baseIndex, f, h; batch > 0 &&
6190	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6191	+	addToPendingCount(1);
6192	+	(rights = new MapReduceValuesToIntTask<K,V>
6193	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6194	+	rights, transformer, r, reducer)).fork();
6195	+	}
6196	+	for (Node<K,V> p; (p = advance()) != null; )
6197	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6198	+	result = r;
6199	+	CountedCompleter<?> c;
6200	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6201	+	@SuppressWarnings("unchecked")
6202	+	MapReduceValuesToIntTask<K,V>
6203	+	t = (MapReduceValuesToIntTask<K,V>)c,
6204	+	s = t.rights;
6205	+	while (s != null) {
6206	+	t.result = reducer.applyAsInt(t.result, s.result);
6207	+	s = t.rights = s.nextRight;
6208	+	}
6209	+	}
6210	+	}
6211	+	}
6212	+	}
6213	+
6214	+	@SuppressWarnings("serial")
6215	+	static final class MapReduceEntriesToIntTask<K,V>
6216	+	extends BulkTask<K,V,Integer> {
6217	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6218	+	final IntBinaryOperator reducer;
6219	+	final int basis;
6220	+	int result;
6221	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6222	+	MapReduceEntriesToIntTask
6223	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6224	+	MapReduceEntriesToIntTask<K,V> nextRight,
6225	+	ToIntFunction<Map.Entry<K,V>> transformer,
6226	+	int basis,
6227	+	IntBinaryOperator reducer) {
6228	+	super(p, b, i, f, t); this.nextRight = nextRight;
6229	+	this.transformer = transformer;
6230	+	this.basis = basis; this.reducer = reducer;
6231	+	}
6232	+	public final Integer getRawResult() { return result; }
6233	+	public final void compute() {
6234	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6235	+	final IntBinaryOperator reducer;
6236	+	if ((transformer = this.transformer) != null &&
6237	+	(reducer = this.reducer) != null) {
6238	+	int r = this.basis;
6239	+	for (int i = baseIndex, f, h; batch > 0 &&
6240	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6241	+	addToPendingCount(1);
6242	+	(rights = new MapReduceEntriesToIntTask<K,V>
6243	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6244	+	rights, transformer, r, reducer)).fork();
6245	+	}
6246	+	for (Node<K,V> p; (p = advance()) != null; )
6247	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6248	+	result = r;
6249	+	CountedCompleter<?> c;
6250	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6251	+	@SuppressWarnings("unchecked")
6252	+	MapReduceEntriesToIntTask<K,V>
6253	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6254	+	s = t.rights;
6255	+	while (s != null) {
6256	+	t.result = reducer.applyAsInt(t.result, s.result);
6257	+	s = t.rights = s.nextRight;
6258	+	}
6259	+	}
6260	+	}
6261	+	}
6262	+	}
6263	+
6264	+	@SuppressWarnings("serial")
6265	+	static final class MapReduceMappingsToIntTask<K,V>
6266	+	extends BulkTask<K,V,Integer> {
6267	+	final ToIntBiFunction<? super K, ? super V> transformer;
6268	+	final IntBinaryOperator reducer;
6269	+	final int basis;
6270	+	int result;
6271	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6272	+	MapReduceMappingsToIntTask
6273	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6274	+	MapReduceMappingsToIntTask<K,V> nextRight,
6275	+	ToIntBiFunction<? super K, ? super V> transformer,
6276	+	int basis,
6277	+	IntBinaryOperator reducer) {
6278	+	super(p, b, i, f, t); this.nextRight = nextRight;
6279	+	this.transformer = transformer;
6280	+	this.basis = basis; this.reducer = reducer;
6281	+	}
6282	+	public final Integer getRawResult() { return result; }
6283	+	public final void compute() {
6284	+	final ToIntBiFunction<? super K, ? super V> transformer;
6285	+	final IntBinaryOperator reducer;
6286	+	if ((transformer = this.transformer) != null &&
6287	+	(reducer = this.reducer) != null) {
6288	+	int r = this.basis;
6289	+	for (int i = baseIndex, f, h; batch > 0 &&
6290	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6291	+	addToPendingCount(1);
6292	+	(rights = new MapReduceMappingsToIntTask<K,V>
6293	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6294	+	rights, transformer, r, reducer)).fork();
6295	+	}
6296	+	for (Node<K,V> p; (p = advance()) != null; )
6297	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6298	+	result = r;
6299	+	CountedCompleter<?> c;
6300	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6301	+	@SuppressWarnings("unchecked")
6302	+	MapReduceMappingsToIntTask<K,V>
6303	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6304	+	s = t.rights;
6305	+	while (s != null) {
6306	+	t.result = reducer.applyAsInt(t.result, s.result);
6307	+	s = t.rights = s.nextRight;
6308	+	}
6309	+	}
6310	+	}
6311	+	}
6312	+	}
6313	+
6314	+	// Unsafe mechanics
6315	+	private static final jdk.internal.misc.Unsafe U = jdk.internal.misc.Unsafe.getUnsafe();
6316	+	private static final long SIZECTL;
6317	+	private static final long TRANSFERINDEX;
6318	+	private static final long BASECOUNT;
6319	+	private static final long CELLSBUSY;
6320	+	private static final long CELLVALUE;
6321	+	private static final int ABASE;
6322	+	private static final int ASHIFT;
6323	+
6324	+	static {
6325	+	try {
6326	+	SIZECTL = U.objectFieldOffset
6327	+	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6328	+	TRANSFERINDEX = U.objectFieldOffset
6329	+	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6330	+	BASECOUNT = U.objectFieldOffset
6331	+	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6332	+	CELLSBUSY = U.objectFieldOffset
6333	+	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6334	+
6335	+	CELLVALUE = U.objectFieldOffset
6336	+	(CounterCell.class.getDeclaredField("value"));
6337	+
6338	+	ABASE = U.arrayBaseOffset(Node[].class);
6339	+	int scale = U.arrayIndexScale(Node[].class);
6340	+	if ((scale & (scale - 1)) != 0)
6341	+	throw new Error("array index scale not a power of two");
6342	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6343	+	} catch (ReflectiveOperationException e) {
6344	+	throw new Error(e);
6345	+	}
6346	+
6347	+	// Reduce the risk of rare disastrous classloading in first call to
6348	+	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6349	+	Class<?> ensureLoaded = LockSupport.class;
6350	+	}
6351		}

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