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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.89 by dl, Tue Jun 6 11:17:58 2006 UTC vs.
Revision 1.310 by jsr166, Wed May 23 06:11:41 2018 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	>	import jdk.internal.misc.Unsafe;
43
44		/**
45		* A hash table supporting full concurrency of retrievals and
46	<	* adjustable expected concurrency for updates. This class obeys the
46	>	* high expected concurrency for updates. This class obeys the
47		* same functional specification as {@link java.util.Hashtable}, and
48		* includes versions of methods corresponding to each method of
49	<	* <tt>Hashtable</tt>. However, even though all operations are
49	>	* {@code Hashtable}. However, even though all operations are
50		* thread-safe, retrieval operations do <em>not</em> entail locking,
51		* and there is <em>not</em> any support for locking the entire table
52		* in a way that prevents all access.  This class is fully
53	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
53	>	* interoperable with {@code Hashtable} in programs that rely on its
54		* thread safety but not on its synchronization details.
55		*
56	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
57	<	* block, so may overlap with update operations (including
58	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
59	<	* of the most recently <em>completed</em> update operations holding
60	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
61	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
62	<	* removal of only some entries.  Similarly, Iterators and
63	<	* Enumerations return elements reflecting the state of the hash table
64	<	* at some point at or since the creation of the iterator/enumeration.
65	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
56	>	* <p>Retrieval operations (including {@code get}) generally do not
57	>	* block, so may overlap with update operations (including {@code put}
58	>	* and {@code remove}). Retrievals reflect the results of the most
59	>	* recently <em>completed</em> update operations holding upon their
60	>	* onset. (More formally, an update operation for a given key bears a
61	>	* <em>happens-before</em> relation with any (non-null) retrieval for
62	>	* that key reporting the updated value.)  For aggregate operations
63	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
64	>	* reflect insertion or removal of only some entries.  Similarly,
65	>	* Iterators, Spliterators and Enumerations return elements reflecting the
66	>	* state of the hash table at some point at or since the creation of the
67	>	* iterator/enumeration.  They do <em>not</em> throw {@link
68	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
69		* However, iterators are designed to be used by only one thread at a time.
70	+	* Bear in mind that the results of aggregate status methods including
71	+	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
72	+	* useful only when a map is not undergoing concurrent updates in other threads.
73	+	* Otherwise the results of these methods reflect transient states
74	+	* that may be adequate for monitoring or estimation purposes, but not
75	+	* for program control.
76	+	*
77	+	* <p>The table is dynamically expanded when there are too many
78	+	* collisions (i.e., keys that have distinct hash codes but fall into
79	+	* the same slot modulo the table size), with the expected average
80	+	* effect of maintaining roughly two bins per mapping (corresponding
81	+	* to a 0.75 load factor threshold for resizing). There may be much
82	+	* variance around this average as mappings are added and removed, but
83	+	* overall, this maintains a commonly accepted time/space tradeoff for
84	+	* hash tables.  However, resizing this or any other kind of hash
85	+	* table may be a relatively slow operation. When possible, it is a
86	+	* good idea to provide a size estimate as an optional {@code
87	+	* initialCapacity} constructor argument. An additional optional
88	+	* {@code loadFactor} constructor argument provides a further means of
89	+	* customizing initial table capacity by specifying the table density
90	+	* to be used in calculating the amount of space to allocate for the
91	+	* given number of elements.  Also, for compatibility with previous
92	+	* versions of this class, constructors may optionally specify an
93	+	* expected {@code concurrencyLevel} as an additional hint for
94	+	* internal sizing.  Note that using many keys with exactly the same
95	+	* {@code hashCode()} is a sure way to slow down performance of any
96	+	* hash table. To ameliorate impact, when keys are {@link Comparable},
97	+	* this class may use comparison order among keys to help break ties.
98	+	*
99	+	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
100	+	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
101	+	* (using {@link #keySet(Object)} when only keys are of interest, and the
102	+	* mapped values are (perhaps transiently) not used or all take the
103	+	* same mapping value.
104		*
105	<	* <p> The allowed concurrency among update operations is guided by
106	<	* the optional <tt>concurrencyLevel</tt> constructor argument
107	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
108	<	* table is internally partitioned to try to permit the indicated
109	<	* number of concurrent updates without contention. Because placement
110	<	* 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.
105	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
106	>	* form of histogram or multiset) by using {@link
107	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
108	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
109	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
110	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
111		*
112		* <p>This class and its views and iterators implement all of the
113		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
114		* interfaces.
115		*
116	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
117	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
116	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
117	>	* does <em>not</em> allow {@code null} to be used as a key or value.
118	>	*
119	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
120	>	* operations that, unlike most {@link Stream} methods, are designed
121	>	* to be safely, and often sensibly, applied even with maps that are
122	>	* being concurrently updated by other threads; for example, when
123	>	* computing a snapshot summary of the values in a shared registry.
124	>	* There are three kinds of operation, each with four forms, accepting
125	>	* functions with keys, values, entries, and (key, value) pairs as
126	>	* arguments and/or return values. Because the elements of a
127	>	* ConcurrentHashMap are not ordered in any particular way, and may be
128	>	* processed in different orders in different parallel executions, the
129	>	* correctness of supplied functions should not depend on any
130	>	* ordering, or on any other objects or values that may transiently
131	>	* change while computation is in progress; and except for forEach
132	>	* actions, should ideally be side-effect-free. Bulk operations on
133	>	* {@link Map.Entry} objects do not support method {@code 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">
227	>	* <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
228		* Java Collections Framework</a>.
229		*
230		* @since 1.5
#	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 HashMap uses power-of two length hash tables, that
152	<	* otherwise encounter collisions for hashCodes that do not differ
153	<	* 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	<	static int hash(int h) {
156	<	// This function ensures that hashCodes that differ only by
157	<	// constant multiples at each bit position have a bounded
158	<	// number of collisions (approximately 8 at default load factor).
159	<	h ^= (h >>> 20) ^ (h >>> 12);
160	<	return h ^ (h >>> 7) ^ (h >>> 4);
161	<	}
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
166	<	* @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) {
169	<	return segments[(hash >>> segmentShift) & segmentMask];
170	<	}
171	<
172	<	/* ---------------- 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
176	<	* out as a user-visible Map.Entry.
177	<	*
178	<	* Because the value field is volatile, not final, it is legal wrt
179	<	* the Java Memory Model for an unsynchronized reader to see null
180	<	* instead of initial value when read via a data race.  Although a
181	<	* reordering leading to this is not likely to ever actually
182	<	* occur, the Segment.readValueUnderLock method is used as a
183	<	* backup in case a null (pre-initialized) value is ever seen in
184	<	* an unsynchronized access method.
555	>	* The bit shift for recording size stamp in sizeCtl.
556		*/
557	<	static final class HashEntry<K,V> {
187	<	final K key;
188	<	final int hash;
189	<	volatile V value;
190	<	final HashEntry<K,V> next;
191	<
192	<	HashEntry(K key, int hash, HashEntry<K,V> next, V value) {
193	<	this.key = key;
194	<	this.hash = hash;
195	<	this.next = next;
196	<	this.value = value;
197	<	}
198	<
199	<	@SuppressWarnings("unchecked")
200	<	static final <K,V> HashEntry<K,V>[] newArray(int i) {
201	<	return new HashEntry[i];
202	<	}
203	<	}
557	>	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
558
559	<	/**
560	<	* Segments are specialized versions of hash tables.  This
207	<	* subclasses from ReentrantLock opportunistically, just to
208	<	* 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.
214	<	* Next fields of nodes are immutable (final).  All list
215	<	* additions are performed at the front of each bin. This
216	<	* makes it easy to check changes, and also fast to traverse.
217	<	* When nodes would otherwise be changed, new nodes are
218	<	* created to replace them. This works well for hash tables
219	<	* since the bin lists tend to be short. (The average length
220	<	* is less than two for the default load factor threshold.)
221	<	*
222	<	* Read operations can thus proceed without locking, but rely
223	<	* on selected uses of volatiles to ensure that completed
224	<	* write operations performed by other threads are
225	<	* noticed. For most purposes, the "count" field, tracking the
226	<	* number of elements, serves as that volatile variable
227	<	* ensuring visibility.  This is convenient because this field
228	<	* needs to be read in many read operations anyway:
229	<	*
230	<	*   - All (unsynchronized) read operations must first read the
231	<	*     "count" field, and should not look at table entries if
232	<	*     it is 0.
233	<	*
234	<	*   - All (synchronized) write operations should write to
235	<	*     the "count" field after structurally changing any bin.
236	<	*     The operations must not take any action that could even
237	<	*     momentarily cause a concurrent read operation to see
238	<	*     inconsistent data. This is made easier by the nature of
239	<	*     the read operations in Map. For example, no operation
240	<	*     can reveal that the table has grown but the threshold
241	<	*     has not yet been updated, so there are no atomicity
242	<	*     requirements for this with respect to reads.
243	<	*
244	<	* As a guide, all critical volatile reads and writes to the
245	<	* count field are marked in code comments.
246	<	*/
247	<
248	<	private static final long serialVersionUID = 2249069246763182397L;
249	<
250	<	/**
251	<	* The number of elements in this segment's region.
252	<	*/
253	<	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
257	<	* used during bulk-read methods to make sure they see a
258	<	* consistent snapshot: If modCounts change during a traversal
259	<	* of segments computing size or checking containsValue, then
260	<	* we might have an inconsistent view of state so (usually)
261	<	* must retry.
262	<	*/
263	<	transient int modCount;
264	<
265	<	/**
266	<	* The table is rehashed when its size exceeds this threshold.
267	<	* (The value of this field is always <tt>(int)(capacity *
268	<	* loadFactor)</tt>.)
269	<	*/
270	<	transient int threshold;
567	>	/** Number of CPUS, to place bounds on some sizings */
568	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
569
570	<	/**
571	<	* The per-segment table.
572	<	*/
573	<	transient volatile HashEntry<K,V>[] table;
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	<	/**
278	<	* The load factor for the hash table.  Even though this value
279	<	* is same for all segments, it is replicated to avoid needing
280	<	* links to outer object.
281	<	* @serial
282	<	*/
283	<	final float loadFactor;
586	>	/* ---------------- Nodes -------------- */
587
588	<	Segment(int initialCapacity, float lf) {
589	<	loadFactor = lf;
590	<	setTable(HashEntry.<K,V>newArray(initialCapacity));
591	<	}
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	<	@SuppressWarnings("unchecked")
603	<	static final <K,V> Segment<K,V>[] newArray(int i) {
604	<	return new Segment[i];
602	>	Node(int hash, K key, V val) {
603	>	this.hash = hash;
604	>	this.key = key;
605	>	this.val = val;
606		}
607
608	<	/**
609	<	* Sets table to new HashEntry array.
610	<	* Call only while holding lock or in constructor.
298	<	*/
299	<	void setTable(HashEntry<K,V>[] newTable) {
300	<	threshold = (int)(newTable.length * loadFactor);
301	<	table = newTable;
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	<	* Returns properly casted first entry of bin for given hash.
615	<	*/
616	<	HashEntry<K,V> getFirst(int hash) {
617	<	HashEntry<K,V>[] tab = table;
618	<	return tab[hash & (tab.length - 1)];
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	<	* Reads value field of an entry under lock. Called if value
314	<	* field ever appears to be null. This is possible only if a
315	<	* compiler happens to reorder a HashEntry initialization with
316	<	* its table assignment, which is legal under memory model
317	<	* but is not known to ever occur.
633	>	* Virtualized support for map.get(); overridden in subclasses.
634		*/
635	<	V readValueUnderLock(HashEntry<K,V> e) {
636	<	lock();
637	<	try {
638	<	return e.value;
639	<	} finally {
640	<	unlock();
641	<	}
642	<	}
643	<
328	<	/* Specialized implementations of map methods */
329	<
330	<	V get(Object key, int hash) {
331	<	if (count != 0) { // read-volatile
332	<	HashEntry<K,V> e = getFirst(hash);
333	<	while (e != null) {
334	<	if (e.hash == hash && key.equals(e.key)) {
335	<	V v = e.value;
336	<	if (v != null)
337	<	return v;
338	<	return readValueUnderLock(e); // recheck
339	<	}
340	<	e = e.next;
341	<	}
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) {
347	<	if (count != 0) { // read-volatile
348	<	HashEntry<K,V> e = getFirst(hash);
349	<	while (e != null) {
350	<	if (e.hash == hash && key.equals(e.key))
351	<	return true;
352	<	e = e.next;
353	<	}
354	<	}
355	<	return false;
356	<	}
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;
383	<	if (e != null && oldValue.equals(e.value)) {
384	<	replaced = true;
385	<	e.value = newValue;
386	<	}
387	<	return replaced;
388	<	} finally {
389	<	unlock();
390	<	}
391	<	}
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 = -1 >>> Integer.numberOfLeadingZeros(c - 1);
677	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
678	>	}
679
680	<	V replace(K key, int hash, V newValue) {
681	<	lock();
682	<	try {
683	<	HashEntry<K,V> e = getFirst(hash);
684	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
685	<	e = e.next;
686	<
687	<	V oldValue = null;
688	<	if (e != null) {
689	<	oldValue = e.value;
690	<	e.value = newValue;
680	>	/**
681	>	* Returns x's Class if it is of the form "class C implements
682	>	* Comparable<C>", else null.
683	>	*/
684	>	static Class<?> comparableClassFor(Object x) {
685	>	if (x instanceof Comparable) {
686	>	Class<?> c; Type[] ts, as; ParameterizedType p;
687	>	if ((c = x.getClass()) == String.class) // bypass checks
688	>	return c;
689	>	if ((ts = c.getGenericInterfaces()) != null) {
690	>	for (Type t : ts) {
691	>	if ((t instanceof ParameterizedType) &&
692	>	((p = (ParameterizedType)t).getRawType() ==
693	>	Comparable.class) &&
694	>	(as = p.getActualTypeArguments()) != null &&
695	>	as.length == 1 && as[0] == c) // type arg is c
696	>	return c;
697		}
405	–	return oldValue;
406	–	} finally {
407	–	unlock();
698		}
699		}
700	+	return null;
701	+	}
702
703	+	/**
704	+	* Returns k.compareTo(x) if x matches kc (k's screened comparable
705	+	* class), else 0.
706	+	*/
707	+	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
708	+	static int compareComparables(Class<?> kc, Object k, Object x) {
709	+	return (x == null || x.getClass() != kc ? 0 :
710	+	((Comparable)k).compareTo(x));
711	+	}
712
713	<	V put(K key, int hash, V value, boolean onlyIfAbsent) {
413	<	lock();
414	<	try {
415	<	int c = count;
416	<	if (c++ > threshold) // ensure capacity
417	<	rehash();
418	<	HashEntry<K,V>[] tab = table;
419	<	int index = hash & (tab.length - 1);
420	<	HashEntry<K,V> first = tab[index];
421	<	HashEntry<K,V> e = first;
422	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
423	<	e = e.next;
424	<
425	<	V oldValue;
426	<	if (e != null) {
427	<	oldValue = e.value;
428	<	if (!onlyIfAbsent)
429	<	e.value = value;
430	<	}
431	<	else {
432	<	oldValue = null;
433	<	++modCount;
434	<	tab[index] = new HashEntry<K,V>(key, hash, first, value);
435	<	count = c; // write-volatile
436	<	}
437	<	return oldValue;
438	<	} finally {
439	<	unlock();
440	<	}
441	<	}
713	>	/* ---------------- Table element access -------------- */
714
715	<	void rehash() {
716	<	HashEntry<K,V>[] oldTable = table;
717	<	int oldCapacity = oldTable.length;
718	<	if (oldCapacity >= MAXIMUM_CAPACITY)
719	<	return;
715	>	/*
716	>	* Atomic access methods are used for table elements as well as
717	>	* elements of in-progress next table while resizing.  All uses of
718	>	* the tab arguments must be null checked by callers.  All callers
719	>	* also paranoically precheck that tab's length is not zero (or an
720	>	* equivalent check), thus ensuring that any index argument taking
721	>	* the form of a hash value anded with (length - 1) is a valid
722	>	* index.  Note that, to be correct wrt arbitrary concurrency
723	>	* errors by users, these checks must operate on local variables,
724	>	* which accounts for some odd-looking inline assignments below.
725	>	* Note that calls to setTabAt always occur within locked regions,
726	>	* and so require only release ordering.
727	>	*/
728	>
729	>	@SuppressWarnings("unchecked")
730	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
731	>	return (Node<K,V>)U.getObjectAcquire(tab, ((long)i << ASHIFT) + ABASE);
732	>	}
733
734	<	/*
735	<	* Reclassify nodes in each list to new Map.  Because we are
736	<	* using power-of-two expansion, the elements from each bin
737	<	* must either stay at same index, or move with a power of two
453	<	* offset. We eliminate unnecessary node creation by catching
454	<	* cases where old nodes can be reused because their next
455	<	* fields won't change. Statistically, at the default
456	<	* threshold, only about one-sixth of them need cloning when
457	<	* a table doubles. The nodes they replace will be garbage
458	<	* collectable as soon as they are no longer referenced by any
459	<	* reader thread that may be in the midst of traversing table
460	<	* right now.
461	<	*/
462	<
463	<	HashEntry<K,V>[] newTable = HashEntry.newArray(oldCapacity<<1);
464	<	threshold = (int)(newTable.length * loadFactor);
465	<	int sizeMask = newTable.length - 1;
466	<	for (int i = 0; i < oldCapacity ; i++) {
467	<	// We need to guarantee that any existing reads of old Map can
468	<	//  proceed. So we cannot yet null out each bin.
469	<	HashEntry<K,V> e = oldTable[i];
470	<
471	<	if (e != null) {
472	<	HashEntry<K,V> next = e.next;
473	<	int idx = e.hash & sizeMask;
474	<
475	<	//  Single node on list
476	<	if (next == null)
477	<	newTable[idx] = e;
734	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
735	>	Node<K,V> c, Node<K,V> v) {
736	>	return U.compareAndSetObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
737	>	}
738
739	<	else {
740	<	// Reuse trailing consecutive sequence at same slot
741	<	HashEntry<K,V> lastRun = e;
482	<	int lastIdx = idx;
483	<	for (HashEntry<K,V> last = next;
484	<	last != null;
485	<	last = last.next) {
486	<	int k = last.hash & sizeMask;
487	<	if (k != lastIdx) {
488	<	lastIdx = k;
489	<	lastRun = last;
490	<	}
491	<	}
492	<	newTable[lastIdx] = lastRun;
739	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
740	>	U.putObjectRelease(tab, ((long)i << ASHIFT) + ABASE, v);
741	>	}
742
743	<	// Clone all remaining nodes
495	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
496	<	int k = p.hash & sizeMask;
497	<	HashEntry<K,V> n = newTable[k];
498	<	newTable[k] = new HashEntry<K,V>(p.key, p.hash,
499	<	n, p.value);
500	<	}
501	<	}
502	<	}
503	<	}
504	<	table = newTable;
505	<	}
743	>	/* ---------------- Fields -------------- */
744
745	<	/**
746	<	* Remove; match on key only if value null, else match both.
747	<	*/
748	<	V remove(Object key, int hash, Object value) {
749	<	lock();
512	<	try {
513	<	int c = count - 1;
514	<	HashEntry<K,V>[] tab = table;
515	<	int index = hash & (tab.length - 1);
516	<	HashEntry<K,V> first = tab[index];
517	<	HashEntry<K,V> e = first;
518	<	while (e != null && (e.hash != hash || !key.equals(e.key)))
519	<	e = e.next;
520	<
521	<	V oldValue = null;
522	<	if (e != null) {
523	<	V v = e.value;
524	<	if (value == null || value.equals(v)) {
525	<	oldValue = v;
526	<	// All entries following removed node can stay
527	<	// in list, but all preceding ones need to be
528	<	// cloned.
529	<	++modCount;
530	<	HashEntry<K,V> newFirst = e.next;
531	<	for (HashEntry<K,V> p = first; p != e; p = p.next)
532	<	newFirst = new HashEntry<K,V>(p.key, p.hash,
533	<	newFirst, p.value);
534	<	tab[index] = newFirst;
535	<	count = c; // write-volatile
536	<	}
537	<	}
538	<	return oldValue;
539	<	} finally {
540	<	unlock();
541	<	}
542	<	}
745	>	/**
746	>	* The array of bins. Lazily initialized upon first insertion.
747	>	* Size is always a power of two. Accessed directly by iterators.
748	>	*/
749	>	transient volatile Node<K,V>[] table;
750
751	<	void clear() {
752	<	if (count != 0) {
753	<	lock();
754	<	try {
548	<	HashEntry<K,V>[] tab = table;
549	<	for (int i = 0; i < tab.length ; i++)
550	<	tab[i] = null;
551	<	++modCount;
552	<	count = 0; // write-volatile
553	<	} finally {
554	<	unlock();
555	<	}
556	<	}
557	<	}
558	<	}
751	>	/**
752	>	* The next table to use; non-null only while resizing.
753	>	*/
754	>	private transient volatile Node<K,V>[] nextTable;
755
756	+	/**
757	+	* Base counter value, used mainly when there is no contention,
758	+	* but also as a fallback during table initialization
759	+	* races. Updated via CAS.
760	+	*/
761	+	private transient volatile long baseCount;
762
763	+	/**
764	+	* Table initialization and resizing control.  When negative, the
765	+	* table is being initialized or resized: -1 for initialization,
766	+	* else -(1 + the number of active resizing threads).  Otherwise,
767	+	* when table is null, holds the initial table size to use upon
768	+	* creation, or 0 for default. After initialization, holds the
769	+	* next element count value upon which to resize the table.
770	+	*/
771	+	private transient volatile int sizeCtl;
772
773	<	/* ---------------- Public operations -------------- */
773	>	/**
774	>	* The next table index (plus one) to split while resizing.
775	>	*/
776	>	private transient volatile int transferIndex;
777
778		/**
779	<	* Creates a new, empty map with the specified initial
566	<	* capacity, load factor and concurrency level.
567	<	*
568	<	* @param initialCapacity the initial capacity. The implementation
569	<	* performs internal sizing to accommodate this many elements.
570	<	* @param loadFactor  the load factor threshold, used to control resizing.
571	<	* Resizing may be performed when the average number of elements per
572	<	* bin exceeds this threshold.
573	<	* @param concurrencyLevel the estimated number of concurrently
574	<	* updating threads. The implementation performs internal sizing
575	<	* to try to accommodate this many threads.
576	<	* @throws IllegalArgumentException if the initial capacity is
577	<	* negative or the load factor or concurrencyLevel are
578	<	* nonpositive.
779	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
780		*/
781	<	public ConcurrentHashMap(int initialCapacity,
581	<	float loadFactor, int concurrencyLevel) {
582	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
583	<	throw new IllegalArgumentException();
781	>	private transient volatile int cellsBusy;
782
783	<	if (concurrencyLevel > MAX_SEGMENTS)
784	<	concurrencyLevel = MAX_SEGMENTS;
783	>	/**
784	>	* Table of counter cells. When non-null, size is a power of 2.
785	>	*/
786	>	private transient volatile CounterCell[] counterCells;
787
788	<	// Find power-of-two sizes best matching arguments
789	<	int sshift = 0;
790	<	int ssize = 1;
791	<	while (ssize < concurrencyLevel) {
592	<	++sshift;
593	<	ssize <<= 1;
594	<	}
595	<	segmentShift = 32 - sshift;
596	<	segmentMask = ssize - 1;
597	<	this.segments = Segment.newArray(ssize);
598	<
599	<	if (initialCapacity > MAXIMUM_CAPACITY)
600	<	initialCapacity = MAXIMUM_CAPACITY;
601	<	int c = initialCapacity / ssize;
602	<	if (c * ssize < initialCapacity)
603	<	++c;
604	<	int cap = 1;
605	<	while (cap < c)
606	<	cap <<= 1;
788	>	// views
789	>	private transient KeySetView<K,V> keySet;
790	>	private transient ValuesView<K,V> values;
791	>	private transient EntrySetView<K,V> entrySet;
792
793	<	for (int i = 0; i < this.segments.length; ++i)
794	<	this.segments[i] = new Segment<K,V>(cap, loadFactor);
610	<	}
793	>
794	>	/* ---------------- Public operations -------------- */
795
796		/**
797	<	* Creates a new, empty map with the specified initial capacity
614	<	* and load factor and with the default concurrencyLevel (16).
615	<	*
616	<	* @param initialCapacity The implementation performs internal
617	<	* sizing to accommodate this many elements.
618	<	* @param loadFactor  the load factor threshold, used to control resizing.
619	<	* Resizing may be performed when the average number of elements per
620	<	* bin exceeds this threshold.
621	<	* @throws IllegalArgumentException if the initial capacity of
622	<	* elements is negative or the load factor is nonpositive
623	<	*
624	<	* @since 1.6
797	>	* Creates a new, empty map with the default initial table size (16).
798		*/
799	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
627	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
799	>	public ConcurrentHashMap() {
800		}
801
802		/**
803	<	* Creates a new, empty map with the specified initial capacity,
804	<	* and with default load factor (0.75) and concurrencyLevel (16).
803	>	* Creates a new, empty map with an initial table size
804	>	* accommodating the specified number of elements without the need
805	>	* to dynamically resize.
806		*
807	<	* @param initialCapacity the initial capacity. The implementation
808	<	* performs internal sizing to accommodate this many elements.
807	>	* @param initialCapacity The implementation performs internal
808	>	* sizing to accommodate this many elements.
809		* @throws IllegalArgumentException if the initial capacity of
810	<	* elements is negative.
810	>	* elements is negative
811		*/
812		public ConcurrentHashMap(int initialCapacity) {
813	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
814	<	}
815	<
816	<	/**
817	<	* Creates a new, empty map with a default initial capacity (16),
818	<	* load factor (0.75) and concurrencyLevel (16).
646	<	*/
647	<	public ConcurrentHashMap() {
648	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
813	>	if (initialCapacity < 0)
814	>	throw new IllegalArgumentException();
815	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
816	>	MAXIMUM_CAPACITY :
817	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
818	>	this.sizeCtl = cap;
819		}
820
821		/**
822		* Creates a new map with the same mappings as the given map.
653	–	* The map is created with a capacity of 1.5 times the number
654	–	* of mappings in the given map or 16 (whichever is greater),
655	–	* and a default load factor (0.75) and concurrencyLevel (16).
823		*
824		* @param m the map
825		*/
826		public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
827	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
661	<	DEFAULT_INITIAL_CAPACITY),
662	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
827	>	this.sizeCtl = DEFAULT_CAPACITY;
828		putAll(m);
829		}
830
831		/**
832	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
832	>	* Creates a new, empty map with an initial table size based on
833	>	* the given number of elements ({@code initialCapacity}) and
834	>	* initial table density ({@code loadFactor}).
835	>	*
836	>	* @param initialCapacity the initial capacity. The implementation
837	>	* performs internal sizing to accommodate this many elements,
838	>	* given the specified load factor.
839	>	* @param loadFactor the load factor (table density) for
840	>	* establishing the initial table size
841	>	* @throws IllegalArgumentException if the initial capacity of
842	>	* elements is negative or the load factor is nonpositive
843		*
844	<	* @return <tt>true</tt> if this map contains no key-value mappings
844	>	* @since 1.6
845		*/
846	<	public boolean isEmpty() {
847	<	final Segment<K,V>[] segments = this.segments;
673	<	/*
674	<	* We keep track of per-segment modCounts to avoid ABA
675	<	* problems in which an element in one segment was added and
676	<	* in another removed during traversal, in which case the
677	<	* table was never actually empty at any point. Note the
678	<	* similar use of modCounts in the size() and containsValue()
679	<	* methods, which are the only other methods also susceptible
680	<	* to ABA problems.
681	<	*/
682	<	int[] mc = new int[segments.length];
683	<	int mcsum = 0;
684	<	for (int i = 0; i < segments.length; ++i) {
685	<	if (segments[i].count != 0)
686	<	return false;
687	<	else
688	<	mcsum += mc[i] = segments[i].modCount;
689	<	}
690	<	// If mcsum happens to be zero, then we know we got a snapshot
691	<	// before any modifications at all were made.  This is
692	<	// probably common enough to bother tracking.
693	<	if (mcsum != 0) {
694	<	for (int i = 0; i < segments.length; ++i) {
695	<	if (segments[i].count != 0 ||
696	<	mc[i] != segments[i].modCount)
697	<	return false;
698	<	}
699	<	}
700	<	return true;
846	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
847	>	this(initialCapacity, loadFactor, 1);
848		}
849
850		/**
851	<	* Returns the number of key-value mappings in this map.  If the
852	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
853	<	* <tt>Integer.MAX_VALUE</tt>.
851	>	* Creates a new, empty map with an initial table size based on
852	>	* the given number of elements ({@code initialCapacity}), table
853	>	* density ({@code loadFactor}), and number of concurrently
854	>	* updating threads ({@code concurrencyLevel}).
855		*
856	<	* @return the number of key-value mappings in this map
856	>	* @param initialCapacity the initial capacity. The implementation
857	>	* performs internal sizing to accommodate this many elements,
858	>	* given the specified load factor.
859	>	* @param loadFactor the load factor (table density) for
860	>	* establishing the initial table size
861	>	* @param concurrencyLevel the estimated number of concurrently
862	>	* updating threads. The implementation may use this value as
863	>	* a sizing hint.
864	>	* @throws IllegalArgumentException if the initial capacity is
865	>	* negative or the load factor or concurrencyLevel are
866	>	* nonpositive
867	>	*/
868	>	public ConcurrentHashMap(int initialCapacity,
869	>	float loadFactor, int concurrencyLevel) {
870	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
871	>	throw new IllegalArgumentException();
872	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
873	>	initialCapacity = concurrencyLevel;   // as estimated threads
874	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
875	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
876	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
877	>	this.sizeCtl = cap;
878	>	}
879	>
880	>	// Original (since JDK1.2) Map methods
881	>
882	>	/**
883	>	* {@inheritDoc}
884		*/
885		public int size() {
886	<	final Segment<K,V>[] segments = this.segments;
887	<	long sum = 0;
888	<	long check = 0;
889	<	int[] mc = new int[segments.length];
890	<	// Try a few times to get accurate count. On failure due to
891	<	// continuous async changes in table, resort to locking.
892	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
893	<	check = 0;
894	<	sum = 0;
895	<	int mcsum = 0;
896	<	for (int i = 0; i < segments.length; ++i) {
722	<	sum += segments[i].count;
723	<	mcsum += mc[i] = segments[i].modCount;
724	<	}
725	<	if (mcsum != 0) {
726	<	for (int i = 0; i < segments.length; ++i) {
727	<	check += segments[i].count;
728	<	if (mc[i] != segments[i].modCount) {
729	<	check = -1; // force retry
730	<	break;
731	<	}
732	<	}
733	<	}
734	<	if (check == sum)
735	<	break;
736	<	}
737	<	if (check != sum) { // Resort to locking all segments
738	<	sum = 0;
739	<	for (int i = 0; i < segments.length; ++i)
740	<	segments[i].lock();
741	<	for (int i = 0; i < segments.length; ++i)
742	<	sum += segments[i].count;
743	<	for (int i = 0; i < segments.length; ++i)
744	<	segments[i].unlock();
745	<	}
746	<	if (sum > Integer.MAX_VALUE)
747	<	return Integer.MAX_VALUE;
748	<	else
749	<	return (int)sum;
886	>	long n = sumCount();
887	>	return ((n < 0L) ? 0 :
888	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
889	>	(int)n);
890	>	}
891	>
892	>	/**
893	>	* {@inheritDoc}
894	>	*/
895	>	public boolean isEmpty() {
896	>	return sumCount() <= 0L; // ignore transient negative values
897		}
898
899		/**
#	Line 761 | Line 908 | public class ConcurrentHashMap<K, V> ext
908		* @throws NullPointerException if the specified key is null
909		*/
910		public V get(Object key) {
911	<	int hash = hash(key.hashCode());
912	<	return segmentFor(hash).get(key, hash);
911	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
912	>	int h = spread(key.hashCode());
913	>	if ((tab = table) != null && (n = tab.length) > 0 &&
914	>	(e = tabAt(tab, (n - 1) & h)) != null) {
915	>	if ((eh = e.hash) == h) {
916	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
917	>	return e.val;
918	>	}
919	>	else if (eh < 0)
920	>	return (p = e.find(h, key)) != null ? p.val : null;
921	>	while ((e = e.next) != null) {
922	>	if (e.hash == h &&
923	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
924	>	return e.val;
925	>	}
926	>	}
927	>	return null;
928		}
929
930		/**
931		* Tests if the specified object is a key in this table.
932		*
933	<	* @param  key   possible key
934	<	* @return <tt>true</tt> if and only if the specified object
933	>	* @param  key possible key
934	>	* @return {@code true} if and only if the specified object
935		*         is a key in this table, as determined by the
936	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
936	>	*         {@code equals} method; {@code false} otherwise
937		* @throws NullPointerException if the specified key is null
938		*/
939		public boolean containsKey(Object key) {
940	<	int hash = hash(key.hashCode());
779	<	return segmentFor(hash).containsKey(key, hash);
940	>	return get(key) != null;
941		}
942
943		/**
944	<	* Returns <tt>true</tt> if this map maps one or more keys to the
945	<	* specified value. Note: This method requires a full internal
946	<	* traversal of the hash table, and so is much slower than
786	<	* method <tt>containsKey</tt>.
944	>	* Returns {@code true} if this map maps one or more keys to the
945	>	* specified value. Note: This method may require a full traversal
946	>	* of the map, and is much slower than method {@code containsKey}.
947		*
948		* @param value value whose presence in this map is to be tested
949	<	* @return <tt>true</tt> if this map maps one or more keys to the
949	>	* @return {@code true} if this map maps one or more keys to the
950		*         specified value
951		* @throws NullPointerException if the specified value is null
952		*/
953		public boolean containsValue(Object value) {
954		if (value == null)
955		throw new NullPointerException();
956	<
957	<	// See explanation of modCount use above
958	<
959	<	final Segment<K,V>[] segments = this.segments;
960	<	int[] mc = new int[segments.length];
961	<
802	<	// Try a few times without locking
803	<	for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
804	<	int sum = 0;
805	<	int mcsum = 0;
806	<	for (int i = 0; i < segments.length; ++i) {
807	<	int c = segments[i].count;
808	<	mcsum += mc[i] = segments[i].modCount;
809	<	if (segments[i].containsValue(value))
956	>	Node<K,V>[] t;
957	>	if ((t = table) != null) {
958	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
959	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
960	>	V v;
961	>	if ((v = p.val) == value || (v != null && value.equals(v)))
962		return true;
963		}
812	–	boolean cleanSweep = true;
813	–	if (mcsum != 0) {
814	–	for (int i = 0; i < segments.length; ++i) {
815	–	int c = segments[i].count;
816	–	if (mc[i] != segments[i].modCount) {
817	–	cleanSweep = false;
818	–	break;
819	–	}
820	–	}
821	–	}
822	–	if (cleanSweep)
823	–	return false;
964		}
965	<	// Resort to locking all segments
826	<	for (int i = 0; i < segments.length; ++i)
827	<	segments[i].lock();
828	<	boolean found = false;
829	<	try {
830	<	for (int i = 0; i < segments.length; ++i) {
831	<	if (segments[i].containsValue(value)) {
832	<	found = true;
833	<	break;
834	<	}
835	<	}
836	<	} finally {
837	<	for (int i = 0; i < segments.length; ++i)
838	<	segments[i].unlock();
839	<	}
840	<	return found;
841	<	}
842	<
843	<	/**
844	<	* Legacy method testing if some key maps into the specified value
845	<	* in this table.  This method is identical in functionality to
846	<	* {@link #containsValue}, and exists solely to ensure
847	<	* full compatibility with class {@link java.util.Hashtable},
848	<	* which supported this method prior to introduction of the
849	<	* Java Collections framework.
850	<
851	<	* @param  value a value to search for
852	<	* @return <tt>true</tt> if and only if some key maps to the
853	<	*         <tt>value</tt> argument in this table as
854	<	*         determined by the <tt>equals</tt> method;
855	<	*         <tt>false</tt> otherwise
856	<	* @throws NullPointerException if the specified value is null
857	<	*/
858	<	public boolean contains(Object value) {
859	<	return containsValue(value);
965	>	return false;
966		}
967
968		/**
969		* Maps the specified key to the specified value in this table.
970		* Neither the key nor the value can be null.
971		*
972	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
972	>	* <p>The value can be retrieved by calling the {@code get} method
973		* with a key that is equal to the original key.
974		*
975		* @param key key with which the specified value is to be associated
976		* @param value value to be associated with the specified key
977	<	* @return the previous value associated with <tt>key</tt>, or
978	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
977	>	* @return the previous value associated with {@code key}, or
978	>	*         {@code null} if there was no mapping for {@code key}
979		* @throws NullPointerException if the specified key or value is null
980		*/
981		public V put(K key, V value) {
982	<	if (value == null)
877	<	throw new NullPointerException();
878	<	int hash = hash(key.hashCode());
879	<	return segmentFor(hash).put(key, hash, value, false);
982	>	return putVal(key, value, false);
983		}
984
985	<	/**
986	<	* {@inheritDoc}
987	<	*
988	<	* @return the previous value associated with the specified key,
989	<	*         or <tt>null</tt> if there was no mapping for the key
990	<	* @throws NullPointerException if the specified key or value is null
991	<	*/
992	<	public V putIfAbsent(K key, V value) {
993	<	if (value == null)
994	<	throw new NullPointerException();
995	<	int hash = hash(key.hashCode());
996	<	return segmentFor(hash).put(key, hash, value, true);
985	>	/** Implementation for put and putIfAbsent */
986	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
987	>	if (key == null || value == null) throw new NullPointerException();
988	>	int hash = spread(key.hashCode());
989	>	int binCount = 0;
990	>	for (Node<K,V>[] tab = table;;) {
991	>	Node<K,V> f; int n, i, fh; K fk; V fv;
992	>	if (tab == null || (n = tab.length) == 0)
993	>	tab = initTable();
994	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
995	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
996	>	break;                   // no lock when adding to empty bin
997	>	}
998	>	else if ((fh = f.hash) == MOVED)
999	>	tab = helpTransfer(tab, f);
1000	>	else if (onlyIfAbsent // check first node without acquiring lock
1001	>	&& fh == hash
1002	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1003	>	&& (fv = f.val) != null)
1004	>	return fv;
1005	>	else {
1006	>	V oldVal = null;
1007	>	synchronized (f) {
1008	>	if (tabAt(tab, i) == f) {
1009	>	if (fh >= 0) {
1010	>	binCount = 1;
1011	>	for (Node<K,V> e = f;; ++binCount) {
1012	>	K ek;
1013	>	if (e.hash == hash &&
1014	>	((ek = e.key) == key ||
1015	>	(ek != null && key.equals(ek)))) {
1016	>	oldVal = e.val;
1017	>	if (!onlyIfAbsent)
1018	>	e.val = value;
1019	>	break;
1020	>	}
1021	>	Node<K,V> pred = e;
1022	>	if ((e = e.next) == null) {
1023	>	pred.next = new Node<K,V>(hash, key, value);
1024	>	break;
1025	>	}
1026	>	}
1027	>	}
1028	>	else if (f instanceof TreeBin) {
1029	>	Node<K,V> p;
1030	>	binCount = 2;
1031	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1032	>	value)) != null) {
1033	>	oldVal = p.val;
1034	>	if (!onlyIfAbsent)
1035	>	p.val = value;
1036	>	}
1037	>	}
1038	>	else if (f instanceof ReservationNode)
1039	>	throw new IllegalStateException("Recursive update");
1040	>	}
1041	>	}
1042	>	if (binCount != 0) {
1043	>	if (binCount >= TREEIFY_THRESHOLD)
1044	>	treeifyBin(tab, i);
1045	>	if (oldVal != null)
1046	>	return oldVal;
1047	>	break;
1048	>	}
1049	>	}
1050	>	}
1051	>	addCount(1L, binCount);
1052	>	return null;
1053		}
1054
1055		/**
#	Line 901 | Line 1060 | public class ConcurrentHashMap<K, V> ext
1060		* @param m mappings to be stored in this map
1061		*/
1062		public void putAll(Map<? extends K, ? extends V> m) {
1063	+	tryPresize(m.size());
1064		for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1065	<	put(e.getKey(), e.getValue());
1065	>	putVal(e.getKey(), e.getValue(), false);
1066		}
1067
1068		/**
#	Line 910 | Line 1070 | public class ConcurrentHashMap<K, V> ext
1070		* This method does nothing if the key is not in the map.
1071		*
1072		* @param  key the key that needs to be removed
1073	<	* @return the previous value associated with <tt>key</tt>, or
1074	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1073	>	* @return the previous value associated with {@code key}, or
1074	>	*         {@code null} if there was no mapping for {@code key}
1075		* @throws NullPointerException if the specified key is null
1076		*/
1077		public V remove(Object key) {
1078	<	int hash = hash(key.hashCode());
1079	<	return segmentFor(hash).remove(key, hash, null);
1078	>	return replaceNode(key, null, null);
1079	>	}
1080	>
1081	>	/**
1082	>	* Implementation for the four public remove/replace methods:
1083	>	* Replaces node value with v, conditional upon match of cv if
1084	>	* non-null.  If resulting value is null, delete.
1085	>	*/
1086	>	final V replaceNode(Object key, V value, Object cv) {
1087	>	int hash = spread(key.hashCode());
1088	>	for (Node<K,V>[] tab = table;;) {
1089	>	Node<K,V> f; int n, i, fh;
1090	>	if (tab == null || (n = tab.length) == 0 ||
1091	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1092	>	break;
1093	>	else if ((fh = f.hash) == MOVED)
1094	>	tab = helpTransfer(tab, f);
1095	>	else {
1096	>	V oldVal = null;
1097	>	boolean validated = false;
1098	>	synchronized (f) {
1099	>	if (tabAt(tab, i) == f) {
1100	>	if (fh >= 0) {
1101	>	validated = true;
1102	>	for (Node<K,V> e = f, pred = null;;) {
1103	>	K ek;
1104	>	if (e.hash == hash &&
1105	>	((ek = e.key) == key ||
1106	>	(ek != null && key.equals(ek)))) {
1107	>	V ev = e.val;
1108	>	if (cv == null || cv == ev ||
1109	>	(ev != null && cv.equals(ev))) {
1110	>	oldVal = ev;
1111	>	if (value != null)
1112	>	e.val = value;
1113	>	else if (pred != null)
1114	>	pred.next = e.next;
1115	>	else
1116	>	setTabAt(tab, i, e.next);
1117	>	}
1118	>	break;
1119	>	}
1120	>	pred = e;
1121	>	if ((e = e.next) == null)
1122	>	break;
1123	>	}
1124	>	}
1125	>	else if (f instanceof TreeBin) {
1126	>	validated = true;
1127	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1128	>	TreeNode<K,V> r, p;
1129	>	if ((r = t.root) != null &&
1130	>	(p = r.findTreeNode(hash, key, null)) != null) {
1131	>	V pv = p.val;
1132	>	if (cv == null || cv == pv ||
1133	>	(pv != null && cv.equals(pv))) {
1134	>	oldVal = pv;
1135	>	if (value != null)
1136	>	p.val = value;
1137	>	else if (t.removeTreeNode(p))
1138	>	setTabAt(tab, i, untreeify(t.first));
1139	>	}
1140	>	}
1141	>	}
1142	>	else if (f instanceof ReservationNode)
1143	>	throw new IllegalStateException("Recursive update");
1144	>	}
1145	>	}
1146	>	if (validated) {
1147	>	if (oldVal != null) {
1148	>	if (value == null)
1149	>	addCount(-1L, -1);
1150	>	return oldVal;
1151	>	}
1152	>	break;
1153	>	}
1154	>	}
1155	>	}
1156	>	return null;
1157	>	}
1158	>
1159	>	/**
1160	>	* Removes all of the mappings from this map.
1161	>	*/
1162	>	public void clear() {
1163	>	long delta = 0L; // negative number of deletions
1164	>	int i = 0;
1165	>	Node<K,V>[] tab = table;
1166	>	while (tab != null && i < tab.length) {
1167	>	int fh;
1168	>	Node<K,V> f = tabAt(tab, i);
1169	>	if (f == null)
1170	>	++i;
1171	>	else if ((fh = f.hash) == MOVED) {
1172	>	tab = helpTransfer(tab, f);
1173	>	i = 0; // restart
1174	>	}
1175	>	else {
1176	>	synchronized (f) {
1177	>	if (tabAt(tab, i) == f) {
1178	>	Node<K,V> p = (fh >= 0 ? f :
1179	>	(f instanceof TreeBin) ?
1180	>	((TreeBin<K,V>)f).first : null);
1181	>	while (p != null) {
1182	>	--delta;
1183	>	p = p.next;
1184	>	}
1185	>	setTabAt(tab, i++, null);
1186	>	}
1187	>	}
1188	>	}
1189	>	}
1190	>	if (delta != 0L)
1191	>	addCount(delta, -1);
1192	>	}
1193	>
1194	>	/**
1195	>	* Returns a {@link Set} view of the keys contained in this map.
1196	>	* The set is backed by the map, so changes to the map are
1197	>	* reflected in the set, and vice-versa. The set supports element
1198	>	* removal, which removes the corresponding mapping from this map,
1199	>	* via the {@code Iterator.remove}, {@code Set.remove},
1200	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1201	>	* operations.  It does not support the {@code add} or
1202	>	* {@code addAll} operations.
1203	>	*
1204	>	* <p>The view's iterators and spliterators are
1205	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1206	>	*
1207	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1208	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1209	>	*
1210	>	* @return the set view
1211	>	*/
1212	>	public KeySetView<K,V> keySet() {
1213	>	KeySetView<K,V> ks;
1214	>	if ((ks = keySet) != null) return ks;
1215	>	return keySet = new KeySetView<K,V>(this, null);
1216	>	}
1217	>
1218	>	/**
1219	>	* Returns a {@link Collection} view of the values contained in this map.
1220	>	* The collection is backed by the map, so changes to the map are
1221	>	* reflected in the collection, and vice-versa.  The collection
1222	>	* supports element removal, which removes the corresponding
1223	>	* mapping from this map, via the {@code Iterator.remove},
1224	>	* {@code Collection.remove}, {@code removeAll},
1225	>	* {@code retainAll}, and {@code clear} operations.  It does not
1226	>	* support the {@code add} or {@code addAll} operations.
1227	>	*
1228	>	* <p>The view's iterators and spliterators are
1229	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1230	>	*
1231	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1232	>	* and {@link Spliterator#NONNULL}.
1233	>	*
1234	>	* @return the collection view
1235	>	*/
1236	>	public Collection<V> values() {
1237	>	ValuesView<K,V> vs;
1238	>	if ((vs = values) != null) return vs;
1239	>	return values = new ValuesView<K,V>(this);
1240	>	}
1241	>
1242	>	/**
1243	>	* Returns a {@link Set} view of the mappings contained in this map.
1244	>	* The set is backed by the map, so changes to the map are
1245	>	* reflected in the set, and vice-versa.  The set supports element
1246	>	* removal, which removes the corresponding mapping from the map,
1247	>	* via the {@code Iterator.remove}, {@code Set.remove},
1248	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1249	>	* operations.
1250	>	*
1251	>	* <p>The view's iterators and spliterators are
1252	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1253	>	*
1254	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1255	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1256	>	*
1257	>	* @return the set view
1258	>	*/
1259	>	public Set<Map.Entry<K,V>> entrySet() {
1260	>	EntrySetView<K,V> es;
1261	>	if ((es = entrySet) != null) return es;
1262	>	return entrySet = new EntrySetView<K,V>(this);
1263	>	}
1264	>
1265	>	/**
1266	>	* Returns the hash code value for this {@link Map}, i.e.,
1267	>	* the sum of, for each key-value pair in the map,
1268	>	* {@code key.hashCode() ^ value.hashCode()}.
1269	>	*
1270	>	* @return the hash code value for this map
1271	>	*/
1272	>	public int hashCode() {
1273	>	int h = 0;
1274	>	Node<K,V>[] t;
1275	>	if ((t = table) != null) {
1276	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1277	>	for (Node<K,V> p; (p = it.advance()) != null; )
1278	>	h += p.key.hashCode() ^ p.val.hashCode();
1279	>	}
1280	>	return h;
1281	>	}
1282	>
1283	>	/**
1284	>	* Returns a string representation of this map.  The string
1285	>	* representation consists of a list of key-value mappings (in no
1286	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1287	>	* mappings are separated by the characters {@code ", "} (comma
1288	>	* and space).  Each key-value mapping is rendered as the key
1289	>	* followed by an equals sign ("{@code =}") followed by the
1290	>	* associated value.
1291	>	*
1292	>	* @return a string representation of this map
1293	>	*/
1294	>	public String toString() {
1295	>	Node<K,V>[] t;
1296	>	int f = (t = table) == null ? 0 : t.length;
1297	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1298	>	StringBuilder sb = new StringBuilder();
1299	>	sb.append('{');
1300	>	Node<K,V> p;
1301	>	if ((p = it.advance()) != null) {
1302	>	for (;;) {
1303	>	K k = p.key;
1304	>	V v = p.val;
1305	>	sb.append(k == this ? "(this Map)" : k);
1306	>	sb.append('=');
1307	>	sb.append(v == this ? "(this Map)" : v);
1308	>	if ((p = it.advance()) == null)
1309	>	break;
1310	>	sb.append(',').append(' ');
1311	>	}
1312	>	}
1313	>	return sb.append('}').toString();
1314	>	}
1315	>
1316	>	/**
1317	>	* Compares the specified object with this map for equality.
1318	>	* Returns {@code true} if the given object is a map with the same
1319	>	* mappings as this map.  This operation may return misleading
1320	>	* results if either map is concurrently modified during execution
1321	>	* of this method.
1322	>	*
1323	>	* @param o object to be compared for equality with this map
1324	>	* @return {@code true} if the specified object is equal to this map
1325	>	*/
1326	>	public boolean equals(Object o) {
1327	>	if (o != this) {
1328	>	if (!(o instanceof Map))
1329	>	return false;
1330	>	Map<?,?> m = (Map<?,?>) o;
1331	>	Node<K,V>[] t;
1332	>	int f = (t = table) == null ? 0 : t.length;
1333	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1334	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1335	>	V val = p.val;
1336	>	Object v = m.get(p.key);
1337	>	if (v == null || (v != val && !v.equals(val)))
1338	>	return false;
1339	>	}
1340	>	for (Map.Entry<?,?> e : m.entrySet()) {
1341	>	Object mk, mv, v;
1342	>	if ((mk = e.getKey()) == null ||
1343	>	(mv = e.getValue()) == null ||
1344	>	(v = get(mk)) == null ||
1345	>	(mv != v && !mv.equals(v)))
1346	>	return false;
1347	>	}
1348	>	}
1349	>	return true;
1350	>	}
1351	>
1352	>	/**
1353	>	* Stripped-down version of helper class used in previous version,
1354	>	* declared for the sake of serialization compatibility.
1355	>	*/
1356	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1357	>	private static final long serialVersionUID = 2249069246763182397L;
1358	>	final float loadFactor;
1359	>	Segment(float lf) { this.loadFactor = lf; }
1360	>	}
1361	>
1362	>	/**
1363	>	* Saves this map to a stream (that is, serializes it).
1364	>	*
1365	>	* @param s the stream
1366	>	* @throws java.io.IOException if an I/O error occurs
1367	>	* @serialData
1368	>	* the serialized fields, followed by the key (Object) and value
1369	>	* (Object) for each key-value mapping, followed by a null pair.
1370	>	* The key-value mappings are emitted in no particular order.
1371	>	*/
1372	>	private void writeObject(java.io.ObjectOutputStream s)
1373	>	throws java.io.IOException {
1374	>	// For serialization compatibility
1375	>	// Emulate segment calculation from previous version of this class
1376	>	int sshift = 0;
1377	>	int ssize = 1;
1378	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1379	>	++sshift;
1380	>	ssize <<= 1;
1381	>	}
1382	>	int segmentShift = 32 - sshift;
1383	>	int segmentMask = ssize - 1;
1384	>	@SuppressWarnings("unchecked")
1385	>	Segment<K,V>[] segments = (Segment<K,V>[])
1386	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1387	>	for (int i = 0; i < segments.length; ++i)
1388	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1389	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1390	>	streamFields.put("segments", segments);
1391	>	streamFields.put("segmentShift", segmentShift);
1392	>	streamFields.put("segmentMask", segmentMask);
1393	>	s.writeFields();
1394	>
1395	>	Node<K,V>[] t;
1396	>	if ((t = table) != null) {
1397	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1398	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1399	>	s.writeObject(p.key);
1400	>	s.writeObject(p.val);
1401	>	}
1402	>	}
1403	>	s.writeObject(null);
1404	>	s.writeObject(null);
1405	>	}
1406	>
1407	>	/**
1408	>	* Reconstitutes this map from a stream (that is, deserializes it).
1409	>	* @param s the stream
1410	>	* @throws ClassNotFoundException if the class of a serialized object
1411	>	*         could not be found
1412	>	* @throws java.io.IOException if an I/O error occurs
1413	>	*/
1414	>	private void readObject(java.io.ObjectInputStream s)
1415	>	throws java.io.IOException, ClassNotFoundException {
1416	>	/*
1417	>	* To improve performance in typical cases, we create nodes
1418	>	* while reading, then place in table once size is known.
1419	>	* However, we must also validate uniqueness and deal with
1420	>	* overpopulated bins while doing so, which requires
1421	>	* specialized versions of putVal mechanics.
1422	>	*/
1423	>	sizeCtl = -1; // force exclusion for table construction
1424	>	s.defaultReadObject();
1425	>	long size = 0L;
1426	>	Node<K,V> p = null;
1427	>	for (;;) {
1428	>	@SuppressWarnings("unchecked")
1429	>	K k = (K) s.readObject();
1430	>	@SuppressWarnings("unchecked")
1431	>	V v = (V) s.readObject();
1432	>	if (k != null && v != null) {
1433	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1434	>	++size;
1435	>	}
1436	>	else
1437	>	break;
1438	>	}
1439	>	if (size == 0L)
1440	>	sizeCtl = 0;
1441	>	else {
1442	>	int n;
1443	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1444	>	n = MAXIMUM_CAPACITY;
1445	>	else {
1446	>	int sz = (int)size;
1447	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1448	>	}
1449	>	@SuppressWarnings("unchecked")
1450	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1451	>	int mask = n - 1;
1452	>	long added = 0L;
1453	>	while (p != null) {
1454	>	boolean insertAtFront;
1455	>	Node<K,V> next = p.next, first;
1456	>	int h = p.hash, j = h & mask;
1457	>	if ((first = tabAt(tab, j)) == null)
1458	>	insertAtFront = true;
1459	>	else {
1460	>	K k = p.key;
1461	>	if (first.hash < 0) {
1462	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1463	>	if (t.putTreeVal(h, k, p.val) == null)
1464	>	++added;
1465	>	insertAtFront = false;
1466	>	}
1467	>	else {
1468	>	int binCount = 0;
1469	>	insertAtFront = true;
1470	>	Node<K,V> q; K qk;
1471	>	for (q = first; q != null; q = q.next) {
1472	>	if (q.hash == h &&
1473	>	((qk = q.key) == k ||
1474	>	(qk != null && k.equals(qk)))) {
1475	>	insertAtFront = false;
1476	>	break;
1477	>	}
1478	>	++binCount;
1479	>	}
1480	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1481	>	insertAtFront = false;
1482	>	++added;
1483	>	p.next = first;
1484	>	TreeNode<K,V> hd = null, tl = null;
1485	>	for (q = p; q != null; q = q.next) {
1486	>	TreeNode<K,V> t = new TreeNode<K,V>
1487	>	(q.hash, q.key, q.val, null, null);
1488	>	if ((t.prev = tl) == null)
1489	>	hd = t;
1490	>	else
1491	>	tl.next = t;
1492	>	tl = t;
1493	>	}
1494	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1495	>	}
1496	>	}
1497	>	}
1498	>	if (insertAtFront) {
1499	>	++added;
1500	>	p.next = first;
1501	>	setTabAt(tab, j, p);
1502	>	}
1503	>	p = next;
1504	>	}
1505	>	table = tab;
1506	>	sizeCtl = n - (n >>> 2);
1507	>	baseCount = added;
1508	>	}
1509	>	}
1510	>
1511	>	// ConcurrentMap methods
1512	>
1513	>	/**
1514	>	* {@inheritDoc}
1515	>	*
1516	>	* @return the previous value associated with the specified key,
1517	>	*         or {@code null} if there was no mapping for the key
1518	>	* @throws NullPointerException if the specified key or value is null
1519	>	*/
1520	>	public V putIfAbsent(K key, V value) {
1521	>	return putVal(key, value, true);
1522		}
1523
1524		/**
#	Line 925 | Line 1527 | public class ConcurrentHashMap<K, V> ext
1527		* @throws NullPointerException if the specified key is null
1528		*/
1529		public boolean remove(Object key, Object value) {
1530	<	int hash = hash(key.hashCode());
1531	<	if (value == null)
1532	<	return false;
931	<	return segmentFor(hash).remove(key, hash, value) != null;
1530	>	if (key == null)
1531	>	throw new NullPointerException();
1532	>	return value != null && replaceNode(key, null, value) != null;
1533		}
1534
1535		/**
#	Line 937 | Line 1538 | public class ConcurrentHashMap<K, V> ext
1538		* @throws NullPointerException if any of the arguments are null
1539		*/
1540		public boolean replace(K key, V oldValue, V newValue) {
1541	<	if (oldValue == null || newValue == null)
1541	>	if (key == null || oldValue == null || newValue == null)
1542		throw new NullPointerException();
1543	<	int hash = hash(key.hashCode());
943	<	return segmentFor(hash).replace(key, hash, oldValue, newValue);
1543	>	return replaceNode(key, newValue, oldValue) != null;
1544		}
1545
1546		/**
1547		* {@inheritDoc}
1548		*
1549		* @return the previous value associated with the specified key,
1550	<	*         or <tt>null</tt> if there was no mapping for the key
1550	>	*         or {@code null} if there was no mapping for the key
1551		* @throws NullPointerException if the specified key or value is null
1552		*/
1553		public V replace(K key, V value) {
1554	<	if (value == null)
1554	>	if (key == null || value == null)
1555		throw new NullPointerException();
1556	<	int hash = hash(key.hashCode());
957	<	return segmentFor(hash).replace(key, hash, value);
1556	>	return replaceNode(key, value, null);
1557		}
1558
1559	+	// Overrides of JDK8+ Map extension method defaults
1560	+
1561		/**
1562	<	* Removes all of the mappings from this map.
1562	>	* Returns the value to which the specified key is mapped, or the
1563	>	* given default value if this map contains no mapping for the
1564	>	* key.
1565	>	*
1566	>	* @param key the key whose associated value is to be returned
1567	>	* @param defaultValue the value to return if this map contains
1568	>	* no mapping for the given key
1569	>	* @return the mapping for the key, if present; else the default value
1570	>	* @throws NullPointerException if the specified key is null
1571		*/
1572	<	public void clear() {
1573	<	for (int i = 0; i < segments.length; ++i)
1574	<	segments[i].clear();
1572	>	public V getOrDefault(Object key, V defaultValue) {
1573	>	V v;
1574	>	return (v = get(key)) == null ? defaultValue : v;
1575	>	}
1576	>
1577	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1578	>	if (action == null) throw new NullPointerException();
1579	>	Node<K,V>[] t;
1580	>	if ((t = table) != null) {
1581	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1582	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1583	>	action.accept(p.key, p.val);
1584	>	}
1585	>	}
1586	>	}
1587	>
1588	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1589	>	if (function == null) throw new NullPointerException();
1590	>	Node<K,V>[] t;
1591	>	if ((t = table) != null) {
1592	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1593	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1594	>	V oldValue = p.val;
1595	>	for (K key = p.key;;) {
1596	>	V newValue = function.apply(key, oldValue);
1597	>	if (newValue == null)
1598	>	throw new NullPointerException();
1599	>	if (replaceNode(key, newValue, oldValue) != null ||
1600	>	(oldValue = get(key)) == null)
1601	>	break;
1602	>	}
1603	>	}
1604	>	}
1605		}
1606
1607		/**
1608	<	* Returns a {@link Set} view of the keys contained in this map.
1609	<	* The set is backed by the map, so changes to the map are
1610	<	* reflected in the set, and vice-versa.  The set supports element
1611	<	* removal, which removes the corresponding mapping from this map,
1612	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1613	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1614	<	* operations.  It does not support the <tt>add</tt> or
1615	<	* <tt>addAll</tt> operations.
1616	<	*
1617	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1618	<	* that will never throw {@link ConcurrentModificationException},
1619	<	* and guarantees to traverse elements as they existed upon
1620	<	* construction of the iterator, and may (but is not guaranteed to)
1621	<	* reflect any modifications subsequent to construction.
1622	<	*/
1623	<	public Set<K> keySet() {
1624	<	Set<K> ks = keySet;
986	<	return (ks != null) ? ks : (keySet = new KeySet());
1608	>	* Helper method for EntrySetView.removeIf.
1609	>	*/
1610	>	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1611	>	if (function == null) throw new NullPointerException();
1612	>	Node<K,V>[] t;
1613	>	boolean removed = false;
1614	>	if ((t = table) != null) {
1615	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1616	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1617	>	K k = p.key;
1618	>	V v = p.val;
1619	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1620	>	if (function.test(e) && replaceNode(k, null, v) != null)
1621	>	removed = true;
1622	>	}
1623	>	}
1624	>	return removed;
1625		}
1626
1627		/**
1628	<	* Returns a {@link Collection} view of the values contained in this map.
991	<	* The collection is backed by the map, so changes to the map are
992	<	* reflected in the collection, and vice-versa.  The collection
993	<	* supports element removal, which removes the corresponding
994	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
995	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
996	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
997	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
998	<	*
999	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1000	<	* that will never throw {@link ConcurrentModificationException},
1001	<	* and guarantees to traverse elements as they existed upon
1002	<	* construction of the iterator, and may (but is not guaranteed to)
1003	<	* reflect any modifications subsequent to construction.
1628	>	* Helper method for ValuesView.removeIf.
1629		*/
1630	<	public Collection<V> values() {
1631	<	Collection<V> vs = values;
1632	<	return (vs != null) ? vs : (values = new Values());
1630	>	boolean removeValueIf(Predicate<? super V> function) {
1631	>	if (function == null) throw new NullPointerException();
1632	>	Node<K,V>[] t;
1633	>	boolean removed = false;
1634	>	if ((t = table) != null) {
1635	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1636	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1637	>	K k = p.key;
1638	>	V v = p.val;
1639	>	if (function.test(v) && replaceNode(k, null, v) != null)
1640	>	removed = true;
1641	>	}
1642	>	}
1643	>	return removed;
1644		}
1645
1646		/**
1647	<	* Returns a {@link Set} view of the mappings contained in this map.
1648	<	* The set is backed by the map, so changes to the map are
1649	<	* reflected in the set, and vice-versa.  The set supports element
1650	<	* removal, which removes the corresponding mapping from the map,
1651	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1652	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1653	<	* operations.  It does not support the <tt>add</tt> or
1654	<	* <tt>addAll</tt> operations.
1655	<	*
1656	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1657	<	* that will never throw {@link ConcurrentModificationException},
1658	<	* and guarantees to traverse elements as they existed upon
1659	<	* construction of the iterator, and may (but is not guaranteed to)
1660	<	* reflect any modifications subsequent to construction.
1647	>	* If the specified key is not already associated with a value,
1648	>	* attempts to compute its value using the given mapping function
1649	>	* and enters it into this map unless {@code null}.  The entire
1650	>	* method invocation is performed atomically, so the function is
1651	>	* applied at most once per key.  Some attempted update operations
1652	>	* on this map by other threads may be blocked while computation
1653	>	* is in progress, so the computation should be short and simple,
1654	>	* and must not attempt to update any other mappings of this map.
1655	>	*
1656	>	* @param key key with which the specified value is to be associated
1657	>	* @param mappingFunction the function to compute a value
1658	>	* @return the current (existing or computed) value associated with
1659	>	*         the specified key, or null if the computed value is null
1660	>	* @throws NullPointerException if the specified key or mappingFunction
1661	>	*         is null
1662	>	* @throws IllegalStateException if the computation detectably
1663	>	*         attempts a recursive update to this map that would
1664	>	*         otherwise never complete
1665	>	* @throws RuntimeException or Error if the mappingFunction does so,
1666	>	*         in which case the mapping is left unestablished
1667		*/
1668	<	public Set<Map.Entry<K,V>> entrySet() {
1669	<	Set<Map.Entry<K,V>> es = entrySet;
1670	<	return (es != null) ? es : (entrySet = new EntrySet());
1668	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1669	>	if (key == null || mappingFunction == null)
1670	>	throw new NullPointerException();
1671	>	int h = spread(key.hashCode());
1672	>	V val = null;
1673	>	int binCount = 0;
1674	>	for (Node<K,V>[] tab = table;;) {
1675	>	Node<K,V> f; int n, i, fh; K fk; V fv;
1676	>	if (tab == null || (n = tab.length) == 0)
1677	>	tab = initTable();
1678	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1679	>	Node<K,V> r = new ReservationNode<K,V>();
1680	>	synchronized (r) {
1681	>	if (casTabAt(tab, i, null, r)) {
1682	>	binCount = 1;
1683	>	Node<K,V> node = null;
1684	>	try {
1685	>	if ((val = mappingFunction.apply(key)) != null)
1686	>	node = new Node<K,V>(h, key, val);
1687	>	} finally {
1688	>	setTabAt(tab, i, node);
1689	>	}
1690	>	}
1691	>	}
1692	>	if (binCount != 0)
1693	>	break;
1694	>	}
1695	>	else if ((fh = f.hash) == MOVED)
1696	>	tab = helpTransfer(tab, f);
1697	>	else if (fh == h    // check first node without acquiring lock
1698	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1699	>	&& (fv = f.val) != null)
1700	>	return fv;
1701	>	else {
1702	>	boolean added = false;
1703	>	synchronized (f) {
1704	>	if (tabAt(tab, i) == f) {
1705	>	if (fh >= 0) {
1706	>	binCount = 1;
1707	>	for (Node<K,V> e = f;; ++binCount) {
1708	>	K ek;
1709	>	if (e.hash == h &&
1710	>	((ek = e.key) == key ||
1711	>	(ek != null && key.equals(ek)))) {
1712	>	val = e.val;
1713	>	break;
1714	>	}
1715	>	Node<K,V> pred = e;
1716	>	if ((e = e.next) == null) {
1717	>	if ((val = mappingFunction.apply(key)) != null) {
1718	>	if (pred.next != null)
1719	>	throw new IllegalStateException("Recursive update");
1720	>	added = true;
1721	>	pred.next = new Node<K,V>(h, key, val);
1722	>	}
1723	>	break;
1724	>	}
1725	>	}
1726	>	}
1727	>	else if (f instanceof TreeBin) {
1728	>	binCount = 2;
1729	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1730	>	TreeNode<K,V> r, p;
1731	>	if ((r = t.root) != null &&
1732	>	(p = r.findTreeNode(h, key, null)) != null)
1733	>	val = p.val;
1734	>	else if ((val = mappingFunction.apply(key)) != null) {
1735	>	added = true;
1736	>	t.putTreeVal(h, key, val);
1737	>	}
1738	>	}
1739	>	else if (f instanceof ReservationNode)
1740	>	throw new IllegalStateException("Recursive update");
1741	>	}
1742	>	}
1743	>	if (binCount != 0) {
1744	>	if (binCount >= TREEIFY_THRESHOLD)
1745	>	treeifyBin(tab, i);
1746	>	if (!added)
1747	>	return val;
1748	>	break;
1749	>	}
1750	>	}
1751	>	}
1752	>	if (val != null)
1753	>	addCount(1L, binCount);
1754	>	return val;
1755	>	}
1756	>
1757	>	/**
1758	>	* If the value for the specified key is present, attempts to
1759	>	* compute a new mapping given the key and its current mapped
1760	>	* value.  The entire method invocation is performed atomically.
1761	>	* Some attempted update operations on this map by other threads
1762	>	* may be blocked while computation is in progress, so the
1763	>	* computation should be short and simple, and must not attempt to
1764	>	* update any other mappings of this map.
1765	>	*
1766	>	* @param key key with which a value may be associated
1767	>	* @param remappingFunction the function to compute a value
1768	>	* @return the new value associated with the specified key, or null if none
1769	>	* @throws NullPointerException if the specified key or remappingFunction
1770	>	*         is null
1771	>	* @throws IllegalStateException if the computation detectably
1772	>	*         attempts a recursive update to this map that would
1773	>	*         otherwise never complete
1774	>	* @throws RuntimeException or Error if the remappingFunction does so,
1775	>	*         in which case the mapping is unchanged
1776	>	*/
1777	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1778	>	if (key == null || remappingFunction == null)
1779	>	throw new NullPointerException();
1780	>	int h = spread(key.hashCode());
1781	>	V val = null;
1782	>	int delta = 0;
1783	>	int binCount = 0;
1784	>	for (Node<K,V>[] tab = table;;) {
1785	>	Node<K,V> f; int n, i, fh;
1786	>	if (tab == null || (n = tab.length) == 0)
1787	>	tab = initTable();
1788	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1789	>	break;
1790	>	else if ((fh = f.hash) == MOVED)
1791	>	tab = helpTransfer(tab, f);
1792	>	else {
1793	>	synchronized (f) {
1794	>	if (tabAt(tab, i) == f) {
1795	>	if (fh >= 0) {
1796	>	binCount = 1;
1797	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1798	>	K ek;
1799	>	if (e.hash == h &&
1800	>	((ek = e.key) == key ||
1801	>	(ek != null && key.equals(ek)))) {
1802	>	val = remappingFunction.apply(key, e.val);
1803	>	if (val != null)
1804	>	e.val = val;
1805	>	else {
1806	>	delta = -1;
1807	>	Node<K,V> en = e.next;
1808	>	if (pred != null)
1809	>	pred.next = en;
1810	>	else
1811	>	setTabAt(tab, i, en);
1812	>	}
1813	>	break;
1814	>	}
1815	>	pred = e;
1816	>	if ((e = e.next) == null)
1817	>	break;
1818	>	}
1819	>	}
1820	>	else if (f instanceof TreeBin) {
1821	>	binCount = 2;
1822	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1823	>	TreeNode<K,V> r, p;
1824	>	if ((r = t.root) != null &&
1825	>	(p = r.findTreeNode(h, key, null)) != null) {
1826	>	val = remappingFunction.apply(key, p.val);
1827	>	if (val != null)
1828	>	p.val = val;
1829	>	else {
1830	>	delta = -1;
1831	>	if (t.removeTreeNode(p))
1832	>	setTabAt(tab, i, untreeify(t.first));
1833	>	}
1834	>	}
1835	>	}
1836	>	else if (f instanceof ReservationNode)
1837	>	throw new IllegalStateException("Recursive update");
1838	>	}
1839	>	}
1840	>	if (binCount != 0)
1841	>	break;
1842	>	}
1843	>	}
1844	>	if (delta != 0)
1845	>	addCount((long)delta, binCount);
1846	>	return val;
1847	>	}
1848	>
1849	>	/**
1850	>	* Attempts to compute a mapping for the specified key and its
1851	>	* current mapped value (or {@code null} if there is no current
1852	>	* mapping). The entire method invocation is performed atomically.
1853	>	* Some attempted update operations on this map by other threads
1854	>	* may be blocked while computation is in progress, so the
1855	>	* computation should be short and simple, and must not attempt to
1856	>	* update any other mappings of this Map.
1857	>	*
1858	>	* @param key key with which the specified value is to be associated
1859	>	* @param remappingFunction the function to compute a value
1860	>	* @return the new value associated with the specified key, or null if none
1861	>	* @throws NullPointerException if the specified key or remappingFunction
1862	>	*         is null
1863	>	* @throws IllegalStateException if the computation detectably
1864	>	*         attempts a recursive update to this map that would
1865	>	*         otherwise never complete
1866	>	* @throws RuntimeException or Error if the remappingFunction does so,
1867	>	*         in which case the mapping is unchanged
1868	>	*/
1869	>	public V compute(K key,
1870	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1871	>	if (key == null || remappingFunction == null)
1872	>	throw new NullPointerException();
1873	>	int h = spread(key.hashCode());
1874	>	V val = null;
1875	>	int delta = 0;
1876	>	int binCount = 0;
1877	>	for (Node<K,V>[] tab = table;;) {
1878	>	Node<K,V> f; int n, i, fh;
1879	>	if (tab == null || (n = tab.length) == 0)
1880	>	tab = initTable();
1881	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1882	>	Node<K,V> r = new ReservationNode<K,V>();
1883	>	synchronized (r) {
1884	>	if (casTabAt(tab, i, null, r)) {
1885	>	binCount = 1;
1886	>	Node<K,V> node = null;
1887	>	try {
1888	>	if ((val = remappingFunction.apply(key, null)) != null) {
1889	>	delta = 1;
1890	>	node = new Node<K,V>(h, key, val);
1891	>	}
1892	>	} finally {
1893	>	setTabAt(tab, i, node);
1894	>	}
1895	>	}
1896	>	}
1897	>	if (binCount != 0)
1898	>	break;
1899	>	}
1900	>	else if ((fh = f.hash) == MOVED)
1901	>	tab = helpTransfer(tab, f);
1902	>	else {
1903	>	synchronized (f) {
1904	>	if (tabAt(tab, i) == f) {
1905	>	if (fh >= 0) {
1906	>	binCount = 1;
1907	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1908	>	K ek;
1909	>	if (e.hash == h &&
1910	>	((ek = e.key) == key ||
1911	>	(ek != null && key.equals(ek)))) {
1912	>	val = remappingFunction.apply(key, e.val);
1913	>	if (val != null)
1914	>	e.val = val;
1915	>	else {
1916	>	delta = -1;
1917	>	Node<K,V> en = e.next;
1918	>	if (pred != null)
1919	>	pred.next = en;
1920	>	else
1921	>	setTabAt(tab, i, en);
1922	>	}
1923	>	break;
1924	>	}
1925	>	pred = e;
1926	>	if ((e = e.next) == null) {
1927	>	val = remappingFunction.apply(key, null);
1928	>	if (val != null) {
1929	>	if (pred.next != null)
1930	>	throw new IllegalStateException("Recursive update");
1931	>	delta = 1;
1932	>	pred.next = new Node<K,V>(h, key, val);
1933	>	}
1934	>	break;
1935	>	}
1936	>	}
1937	>	}
1938	>	else if (f instanceof TreeBin) {
1939	>	binCount = 1;
1940	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1941	>	TreeNode<K,V> r, p;
1942	>	if ((r = t.root) != null)
1943	>	p = r.findTreeNode(h, key, null);
1944	>	else
1945	>	p = null;
1946	>	V pv = (p == null) ? null : p.val;
1947	>	val = remappingFunction.apply(key, pv);
1948	>	if (val != null) {
1949	>	if (p != null)
1950	>	p.val = val;
1951	>	else {
1952	>	delta = 1;
1953	>	t.putTreeVal(h, key, val);
1954	>	}
1955	>	}
1956	>	else if (p != null) {
1957	>	delta = -1;
1958	>	if (t.removeTreeNode(p))
1959	>	setTabAt(tab, i, untreeify(t.first));
1960	>	}
1961	>	}
1962	>	else if (f instanceof ReservationNode)
1963	>	throw new IllegalStateException("Recursive update");
1964	>	}
1965	>	}
1966	>	if (binCount != 0) {
1967	>	if (binCount >= TREEIFY_THRESHOLD)
1968	>	treeifyBin(tab, i);
1969	>	break;
1970	>	}
1971	>	}
1972	>	}
1973	>	if (delta != 0)
1974	>	addCount((long)delta, binCount);
1975	>	return val;
1976	>	}
1977	>
1978	>	/**
1979	>	* If the specified key is not already associated with a
1980	>	* (non-null) value, associates it with the given value.
1981	>	* Otherwise, replaces the value with the results of the given
1982	>	* remapping function, or removes if {@code null}. The entire
1983	>	* method invocation is performed atomically.  Some attempted
1984	>	* update operations on this map by other threads may be blocked
1985	>	* while computation is in progress, so the computation should be
1986	>	* short and simple, and must not attempt to update any other
1987	>	* mappings of this Map.
1988	>	*
1989	>	* @param key key with which the specified value is to be associated
1990	>	* @param value the value to use if absent
1991	>	* @param remappingFunction the function to recompute a value if present
1992	>	* @return the new value associated with the specified key, or null if none
1993	>	* @throws NullPointerException if the specified key or the
1994	>	*         remappingFunction is null
1995	>	* @throws RuntimeException or Error if the remappingFunction does so,
1996	>	*         in which case the mapping is unchanged
1997	>	*/
1998	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1999	>	if (key == null || value == null || remappingFunction == null)
2000	>	throw new NullPointerException();
2001	>	int h = spread(key.hashCode());
2002	>	V val = null;
2003	>	int delta = 0;
2004	>	int binCount = 0;
2005	>	for (Node<K,V>[] tab = table;;) {
2006	>	Node<K,V> f; int n, i, fh;
2007	>	if (tab == null || (n = tab.length) == 0)
2008	>	tab = initTable();
2009	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2010	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2011	>	delta = 1;
2012	>	val = value;
2013	>	break;
2014	>	}
2015	>	}
2016	>	else if ((fh = f.hash) == MOVED)
2017	>	tab = helpTransfer(tab, f);
2018	>	else {
2019	>	synchronized (f) {
2020	>	if (tabAt(tab, i) == f) {
2021	>	if (fh >= 0) {
2022	>	binCount = 1;
2023	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
2024	>	K ek;
2025	>	if (e.hash == h &&
2026	>	((ek = e.key) == key ||
2027	>	(ek != null && key.equals(ek)))) {
2028	>	val = remappingFunction.apply(e.val, value);
2029	>	if (val != null)
2030	>	e.val = val;
2031	>	else {
2032	>	delta = -1;
2033	>	Node<K,V> en = e.next;
2034	>	if (pred != null)
2035	>	pred.next = en;
2036	>	else
2037	>	setTabAt(tab, i, en);
2038	>	}
2039	>	break;
2040	>	}
2041	>	pred = e;
2042	>	if ((e = e.next) == null) {
2043	>	delta = 1;
2044	>	val = value;
2045	>	pred.next = new Node<K,V>(h, key, val);
2046	>	break;
2047	>	}
2048	>	}
2049	>	}
2050	>	else if (f instanceof TreeBin) {
2051	>	binCount = 2;
2052	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2053	>	TreeNode<K,V> r = t.root;
2054	>	TreeNode<K,V> p = (r == null) ? null :
2055	>	r.findTreeNode(h, key, null);
2056	>	val = (p == null) ? value :
2057	>	remappingFunction.apply(p.val, value);
2058	>	if (val != null) {
2059	>	if (p != null)
2060	>	p.val = val;
2061	>	else {
2062	>	delta = 1;
2063	>	t.putTreeVal(h, key, val);
2064	>	}
2065	>	}
2066	>	else if (p != null) {
2067	>	delta = -1;
2068	>	if (t.removeTreeNode(p))
2069	>	setTabAt(tab, i, untreeify(t.first));
2070	>	}
2071	>	}
2072	>	else if (f instanceof ReservationNode)
2073	>	throw new IllegalStateException("Recursive update");
2074	>	}
2075	>	}
2076	>	if (binCount != 0) {
2077	>	if (binCount >= TREEIFY_THRESHOLD)
2078	>	treeifyBin(tab, i);
2079	>	break;
2080	>	}
2081	>	}
2082	>	}
2083	>	if (delta != 0)
2084	>	addCount((long)delta, binCount);
2085	>	return val;
2086	>	}
2087	>
2088	>	// Hashtable legacy methods
2089	>
2090	>	/**
2091	>	* Tests if some key maps into the specified value in this table.
2092	>	*
2093	>	* <p>Note that this method is identical in functionality to
2094	>	* {@link #containsValue(Object)}, and exists solely to ensure
2095	>	* full compatibility with class {@link java.util.Hashtable},
2096	>	* which supported this method prior to introduction of the
2097	>	* Java Collections Framework.
2098	>	*
2099	>	* @param  value a value to search for
2100	>	* @return {@code true} if and only if some key maps to the
2101	>	*         {@code value} argument in this table as
2102	>	*         determined by the {@code equals} method;
2103	>	*         {@code false} otherwise
2104	>	* @throws NullPointerException if the specified value is null
2105	>	*/
2106	>	public boolean contains(Object value) {
2107	>	return containsValue(value);
2108		}
2109
2110		/**
2111		* Returns an enumeration of the keys in this table.
2112		*
2113		* @return an enumeration of the keys in this table
2114	<	* @see #keySet
2114	>	* @see #keySet()
2115		*/
2116		public Enumeration<K> keys() {
2117	<	return new KeyIterator();
2117	>	Node<K,V>[] t;
2118	>	int f = (t = table) == null ? 0 : t.length;
2119	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2120		}
2121
2122		/**
2123		* Returns an enumeration of the values in this table.
2124		*
2125		* @return an enumeration of the values in this table
2126	<	* @see #values
2126	>	* @see #values()
2127		*/
2128		public Enumeration<V> elements() {
2129	<	return new ValueIterator();
2129	>	Node<K,V>[] t;
2130	>	int f = (t = table) == null ? 0 : t.length;
2131	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2132		}
2133
2134	<	/* ---------------- Iterator Support -------------- */
2134	>	// ConcurrentHashMap-only methods
2135	>
2136	>	/**
2137	>	* Returns the number of mappings. This method should be used
2138	>	* instead of {@link #size} because a ConcurrentHashMap may
2139	>	* contain more mappings than can be represented as an int. The
2140	>	* value returned is an estimate; the actual count may differ if
2141	>	* there are concurrent insertions or removals.
2142	>	*
2143	>	* @return the number of mappings
2144	>	* @since 1.8
2145	>	*/
2146	>	public long mappingCount() {
2147	>	long n = sumCount();
2148	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2149	>	}
2150
2151	<	abstract class HashIterator {
2152	<	int nextSegmentIndex;
2153	<	int nextTableIndex;
2154	<	HashEntry<K,V>[] currentTable;
2155	<	HashEntry<K, V> nextEntry;
2156	<	HashEntry<K, V> lastReturned;
2151	>	/**
2152	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2153	>	* from the given type to {@code Boolean.TRUE}.
2154	>	*
2155	>	* @param <K> the element type of the returned set
2156	>	* @return the new set
2157	>	* @since 1.8
2158	>	*/
2159	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2160	>	return new KeySetView<K,Boolean>
2161	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2162	>	}
2163
2164	<	HashIterator() {
2165	<	nextSegmentIndex = segments.length - 1;
2166	<	nextTableIndex = -1;
2167	<	advance();
2164	>	/**
2165	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2166	>	* from the given type to {@code Boolean.TRUE}.
2167	>	*
2168	>	* @param initialCapacity The implementation performs internal
2169	>	* sizing to accommodate this many elements.
2170	>	* @param <K> the element type of the returned set
2171	>	* @return the new set
2172	>	* @throws IllegalArgumentException if the initial capacity of
2173	>	* elements is negative
2174	>	* @since 1.8
2175	>	*/
2176	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2177	>	return new KeySetView<K,Boolean>
2178	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2179	>	}
2180	>
2181	>	/**
2182	>	* Returns a {@link Set} view of the keys in this map, using the
2183	>	* given common mapped value for any additions (i.e., {@link
2184	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2185	>	* This is of course only appropriate if it is acceptable to use
2186	>	* the same value for all additions from this view.
2187	>	*
2188	>	* @param mappedValue the mapped value to use for any additions
2189	>	* @return the set view
2190	>	* @throws NullPointerException if the mappedValue is null
2191	>	*/
2192	>	public KeySetView<K,V> keySet(V mappedValue) {
2193	>	if (mappedValue == null)
2194	>	throw new NullPointerException();
2195	>	return new KeySetView<K,V>(this, mappedValue);
2196	>	}
2197	>
2198	>	/* ---------------- Special Nodes -------------- */
2199	>
2200	>	/**
2201	>	* A node inserted at head of bins during transfer operations.
2202	>	*/
2203	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2204	>	final Node<K,V>[] nextTable;
2205	>	ForwardingNode(Node<K,V>[] tab) {
2206	>	super(MOVED, null, null);
2207	>	this.nextTable = tab;
2208	>	}
2209	>
2210	>	Node<K,V> find(int h, Object k) {
2211	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2212	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2213	>	Node<K,V> e; int n;
2214	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2215	>	(e = tabAt(tab, (n - 1) & h)) == null)
2216	>	return null;
2217	>	for (;;) {
2218	>	int eh; K ek;
2219	>	if ((eh = e.hash) == h &&
2220	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2221	>	return e;
2222	>	if (eh < 0) {
2223	>	if (e instanceof ForwardingNode) {
2224	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2225	>	continue outer;
2226	>	}
2227	>	else
2228	>	return e.find(h, k);
2229	>	}
2230	>	if ((e = e.next) == null)
2231	>	return null;
2232	>	}
2233	>	}
2234		}
2235	+	}
2236	+
2237	+	/**
2238	+	* A place-holder node used in computeIfAbsent and compute.
2239	+	*/
2240	+	static final class ReservationNode<K,V> extends Node<K,V> {
2241	+	ReservationNode() {
2242	+	super(RESERVED, null, null);
2243	+	}
2244	+
2245	+	Node<K,V> find(int h, Object k) {
2246	+	return null;
2247	+	}
2248	+	}
2249	+
2250	+	/* ---------------- Table Initialization and Resizing -------------- */
2251	+
2252	+	/**
2253	+	* Returns the stamp bits for resizing a table of size n.
2254	+	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2255	+	*/
2256	+	static final int resizeStamp(int n) {
2257	+	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2258	+	}
2259
2260	<	public boolean hasMoreElements() { return hasNext(); }
2260	>	/**
2261	>	* Initializes table, using the size recorded in sizeCtl.
2262	>	*/
2263	>	private final Node<K,V>[] initTable() {
2264	>	Node<K,V>[] tab; int sc;
2265	>	while ((tab = table) == null || tab.length == 0) {
2266	>	if ((sc = sizeCtl) < 0)
2267	>	Thread.yield(); // lost initialization race; just spin
2268	>	else if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2269	>	try {
2270	>	if ((tab = table) == null || tab.length == 0) {
2271	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2272	>	@SuppressWarnings("unchecked")
2273	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2274	>	table = tab = nt;
2275	>	sc = n - (n >>> 2);
2276	>	}
2277	>	} finally {
2278	>	sizeCtl = sc;
2279	>	}
2280	>	break;
2281	>	}
2282	>	}
2283	>	return tab;
2284	>	}
2285
2286	<	final void advance() {
2287	<	if (nextEntry != null && (nextEntry = nextEntry.next) != null)
2286	>	/**
2287	>	* Adds to count, and if table is too small and not already
2288	>	* resizing, initiates transfer. If already resizing, helps
2289	>	* perform transfer if work is available.  Rechecks occupancy
2290	>	* after a transfer to see if another resize is already needed
2291	>	* because resizings are lagging additions.
2292	>	*
2293	>	* @param x the count to add
2294	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2295	>	*/
2296	>	private final void addCount(long x, int check) {
2297	>	CounterCell[] cs; long b, s;
2298	>	if ((cs = counterCells) != null ||
2299	>	!U.compareAndSetLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2300	>	CounterCell c; long v; int m;
2301	>	boolean uncontended = true;
2302	>	if (cs == null || (m = cs.length - 1) < 0 ||
2303	>	(c = cs[ThreadLocalRandom.getProbe() & m]) == null ||
2304	>	!(uncontended =
2305	>	U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))) {
2306	>	fullAddCount(x, uncontended);
2307	>	return;
2308	>	}
2309	>	if (check <= 1)
2310		return;
2311	+	s = sumCount();
2312	+	}
2313	+	if (check >= 0) {
2314	+	Node<K,V>[] tab, nt; int n, sc;
2315	+	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2316	+	(n = tab.length) < MAXIMUM_CAPACITY) {
2317	+	int rs = resizeStamp(n);
2318	+	if (sc < 0) {
2319	+	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2320	+	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2321	+	transferIndex <= 0)
2322	+	break;
2323	+	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
2324	+	transfer(tab, nt);
2325	+	}
2326	+	else if (U.compareAndSetInt(this, SIZECTL, sc,
2327	+	(rs << RESIZE_STAMP_SHIFT) + 2))
2328	+	transfer(tab, null);
2329	+	s = sumCount();
2330	+	}
2331	+	}
2332	+	}
2333	+
2334	+	/**
2335	+	* Helps transfer if a resize is in progress.
2336	+	*/
2337	+	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2338	+	Node<K,V>[] nextTab; int sc;
2339	+	if (tab != null && (f instanceof ForwardingNode) &&
2340	+	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2341	+	int rs = resizeStamp(tab.length);
2342	+	while (nextTab == nextTable && table == tab &&
2343	+	(sc = sizeCtl) < 0) {
2344	+	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2345	+	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2346	+	break;
2347	+	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
2348	+	transfer(tab, nextTab);
2349	+	break;
2350	+	}
2351	+	}
2352	+	return nextTab;
2353	+	}
2354	+	return table;
2355	+	}
2356
2357	<	while (nextTableIndex >= 0) {
2358	<	if ( (nextEntry = currentTable[nextTableIndex--]) != null)
2357	>	/**
2358	>	* Tries to presize table to accommodate the given number of elements.
2359	>	*
2360	>	* @param size number of elements (doesn't need to be perfectly accurate)
2361	>	*/
2362	>	private final void tryPresize(int size) {
2363	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2364	>	tableSizeFor(size + (size >>> 1) + 1);
2365	>	int sc;
2366	>	while ((sc = sizeCtl) >= 0) {
2367	>	Node<K,V>[] tab = table; int n;
2368	>	if (tab == null || (n = tab.length) == 0) {
2369	>	n = (sc > c) ? sc : c;
2370	>	if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2371	>	try {
2372	>	if (table == tab) {
2373	>	@SuppressWarnings("unchecked")
2374	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2375	>	table = nt;
2376	>	sc = n - (n >>> 2);
2377	>	}
2378	>	} finally {
2379	>	sizeCtl = sc;
2380	>	}
2381	>	}
2382	>	}
2383	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2384	>	break;
2385	>	else if (tab == table) {
2386	>	int rs = resizeStamp(n);
2387	>	if (U.compareAndSetInt(this, SIZECTL, sc,
2388	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2389	>	transfer(tab, null);
2390	>	}
2391	>	}
2392	>	}
2393	>
2394	>	/**
2395	>	* Moves and/or copies the nodes in each bin to new table. See
2396	>	* above for explanation.
2397	>	*/
2398	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2399	>	int n = tab.length, stride;
2400	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2401	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2402	>	if (nextTab == null) {            // initiating
2403	>	try {
2404	>	@SuppressWarnings("unchecked")
2405	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2406	>	nextTab = nt;
2407	>	} catch (Throwable ex) {      // try to cope with OOME
2408	>	sizeCtl = Integer.MAX_VALUE;
2409	>	return;
2410	>	}
2411	>	nextTable = nextTab;
2412	>	transferIndex = n;
2413	>	}
2414	>	int nextn = nextTab.length;
2415	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2416	>	boolean advance = true;
2417	>	boolean finishing = false; // to ensure sweep before committing nextTab
2418	>	for (int i = 0, bound = 0;;) {
2419	>	Node<K,V> f; int fh;
2420	>	while (advance) {
2421	>	int nextIndex, nextBound;
2422	>	if (--i >= bound || finishing)
2423	>	advance = false;
2424	>	else if ((nextIndex = transferIndex) <= 0) {
2425	>	i = -1;
2426	>	advance = false;
2427	>	}
2428	>	else if (U.compareAndSetInt
2429	>	(this, TRANSFERINDEX, nextIndex,
2430	>	nextBound = (nextIndex > stride ?
2431	>	nextIndex - stride : 0))) {
2432	>	bound = nextBound;
2433	>	i = nextIndex - 1;
2434	>	advance = false;
2435	>	}
2436	>	}
2437	>	if (i < 0 || i >= n || i + n >= nextn) {
2438	>	int sc;
2439	>	if (finishing) {
2440	>	nextTable = null;
2441	>	table = nextTab;
2442	>	sizeCtl = (n << 1) - (n >>> 1);
2443		return;
2444	+	}
2445	+	if (U.compareAndSetInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2446	+	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2447	+	return;
2448	+	finishing = advance = true;
2449	+	i = n; // recheck before commit
2450	+	}
2451	+	}
2452	+	else if ((f = tabAt(tab, i)) == null)
2453	+	advance = casTabAt(tab, i, null, fwd);
2454	+	else if ((fh = f.hash) == MOVED)
2455	+	advance = true; // already processed
2456	+	else {
2457	+	synchronized (f) {
2458	+	if (tabAt(tab, i) == f) {
2459	+	Node<K,V> ln, hn;
2460	+	if (fh >= 0) {
2461	+	int runBit = fh & n;
2462	+	Node<K,V> lastRun = f;
2463	+	for (Node<K,V> p = f.next; p != null; p = p.next) {
2464	+	int b = p.hash & n;
2465	+	if (b != runBit) {
2466	+	runBit = b;
2467	+	lastRun = p;
2468	+	}
2469	+	}
2470	+	if (runBit == 0) {
2471	+	ln = lastRun;
2472	+	hn = null;
2473	+	}
2474	+	else {
2475	+	hn = lastRun;
2476	+	ln = null;
2477	+	}
2478	+	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2479	+	int ph = p.hash; K pk = p.key; V pv = p.val;
2480	+	if ((ph & n) == 0)
2481	+	ln = new Node<K,V>(ph, pk, pv, ln);
2482	+	else
2483	+	hn = new Node<K,V>(ph, pk, pv, hn);
2484	+	}
2485	+	setTabAt(nextTab, i, ln);
2486	+	setTabAt(nextTab, i + n, hn);
2487	+	setTabAt(tab, i, fwd);
2488	+	advance = true;
2489	+	}
2490	+	else if (f instanceof TreeBin) {
2491	+	TreeBin<K,V> t = (TreeBin<K,V>)f;
2492	+	TreeNode<K,V> lo = null, loTail = null;
2493	+	TreeNode<K,V> hi = null, hiTail = null;
2494	+	int lc = 0, hc = 0;
2495	+	for (Node<K,V> e = t.first; e != null; e = e.next) {
2496	+	int h = e.hash;
2497	+	TreeNode<K,V> p = new TreeNode<K,V>
2498	+	(h, e.key, e.val, null, null);
2499	+	if ((h & n) == 0) {
2500	+	if ((p.prev = loTail) == null)
2501	+	lo = p;
2502	+	else
2503	+	loTail.next = p;
2504	+	loTail = p;
2505	+	++lc;
2506	+	}
2507	+	else {
2508	+	if ((p.prev = hiTail) == null)
2509	+	hi = p;
2510	+	else
2511	+	hiTail.next = p;
2512	+	hiTail = p;
2513	+	++hc;
2514	+	}
2515	+	}
2516	+	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2517	+	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2518	+	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2519	+	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2520	+	setTabAt(nextTab, i, ln);
2521	+	setTabAt(nextTab, i + n, hn);
2522	+	setTabAt(tab, i, fwd);
2523	+	advance = true;
2524	+	}
2525	+	}
2526	+	}
2527	+	}
2528	+	}
2529	+	}
2530	+
2531	+	/* ---------------- Counter support -------------- */
2532	+
2533	+	/**
2534	+	* A padded cell for distributing counts.  Adapted from LongAdder
2535	+	* and Striped64.  See their internal docs for explanation.
2536	+	*/
2537	+	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2538	+	volatile long value;
2539	+	CounterCell(long x) { value = x; }
2540	+	}
2541	+
2542	+	final long sumCount() {
2543	+	CounterCell[] cs = counterCells;
2544	+	long sum = baseCount;
2545	+	if (cs != null) {
2546	+	for (CounterCell c : cs)
2547	+	if (c != null)
2548	+	sum += c.value;
2549	+	}
2550	+	return sum;
2551	+	}
2552	+
2553	+	// See LongAdder version for explanation
2554	+	private final void fullAddCount(long x, boolean wasUncontended) {
2555	+	int h;
2556	+	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2557	+	ThreadLocalRandom.localInit();      // force initialization
2558	+	h = ThreadLocalRandom.getProbe();
2559	+	wasUncontended = true;
2560	+	}
2561	+	boolean collide = false;                // True if last slot nonempty
2562	+	for (;;) {
2563	+	CounterCell[] cs; CounterCell c; int n; long v;
2564	+	if ((cs = counterCells) != null && (n = cs.length) > 0) {
2565	+	if ((c = cs[(n - 1) & h]) == null) {
2566	+	if (cellsBusy == 0) {            // Try to attach new Cell
2567	+	CounterCell r = new CounterCell(x); // Optimistic create
2568	+	if (cellsBusy == 0 &&
2569	+	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2570	+	boolean created = false;
2571	+	try {               // Recheck under lock
2572	+	CounterCell[] rs; int m, j;
2573	+	if ((rs = counterCells) != null &&
2574	+	(m = rs.length) > 0 &&
2575	+	rs[j = (m - 1) & h] == null) {
2576	+	rs[j] = r;
2577	+	created = true;
2578	+	}
2579	+	} finally {
2580	+	cellsBusy = 0;
2581	+	}
2582	+	if (created)
2583	+	break;
2584	+	continue;           // Slot is now non-empty
2585	+	}
2586	+	}
2587	+	collide = false;
2588	+	}
2589	+	else if (!wasUncontended)       // CAS already known to fail
2590	+	wasUncontended = true;      // Continue after rehash
2591	+	else if (U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))
2592	+	break;
2593	+	else if (counterCells != cs || n >= NCPU)
2594	+	collide = false;            // At max size or stale
2595	+	else if (!collide)
2596	+	collide = true;
2597	+	else if (cellsBusy == 0 &&
2598	+	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2599	+	try {
2600	+	if (counterCells == cs) // Expand table unless stale
2601	+	counterCells = Arrays.copyOf(cs, n << 1);
2602	+	} finally {
2603	+	cellsBusy = 0;
2604	+	}
2605	+	collide = false;
2606	+	continue;                   // Retry with expanded table
2607	+	}
2608	+	h = ThreadLocalRandom.advanceProbe(h);
2609		}
2610	+	else if (cellsBusy == 0 && counterCells == cs &&
2611	+	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2612	+	boolean init = false;
2613	+	try {                           // Initialize table
2614	+	if (counterCells == cs) {
2615	+	CounterCell[] rs = new CounterCell[2];
2616	+	rs[h & 1] = new CounterCell(x);
2617	+	counterCells = rs;
2618	+	init = true;
2619	+	}
2620	+	} finally {
2621	+	cellsBusy = 0;
2622	+	}
2623	+	if (init)
2624	+	break;
2625	+	}
2626	+	else if (U.compareAndSetLong(this, BASECOUNT, v = baseCount, v + x))
2627	+	break;                          // Fall back on using base
2628	+	}
2629	+	}
2630
2631	<	while (nextSegmentIndex >= 0) {
2632	<	Segment<K,V> seg = segments[nextSegmentIndex--];
2633	<	if (seg.count != 0) {
2634	<	currentTable = seg.table;
2635	<	for (int j = currentTable.length - 1; j >= 0; --j) {
2636	<	if ( (nextEntry = currentTable[j]) != null) {
2637	<	nextTableIndex = j - 1;
2638	<	return;
2631	>	/* ---------------- Conversion from/to TreeBins -------------- */
2632	>
2633	>	/**
2634	>	* Replaces all linked nodes in bin at given index unless table is
2635	>	* too small, in which case resizes instead.
2636	>	*/
2637	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2638	>	Node<K,V> b; int n;
2639	>	if (tab != null) {
2640	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2641	>	tryPresize(n << 1);
2642	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2643	>	synchronized (b) {
2644	>	if (tabAt(tab, index) == b) {
2645	>	TreeNode<K,V> hd = null, tl = null;
2646	>	for (Node<K,V> e = b; e != null; e = e.next) {
2647	>	TreeNode<K,V> p =
2648	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2649	>	null, null);
2650	>	if ((p.prev = tl) == null)
2651	>	hd = p;
2652	>	else
2653	>	tl.next = p;
2654	>	tl = p;
2655		}
2656	+	setTabAt(tab, index, new TreeBin<K,V>(hd));
2657		}
2658		}
2659		}
2660		}
2661	+	}
2662	+
2663	+	/**
2664	+	* Returns a list of non-TreeNodes replacing those in given list.
2665	+	*/
2666	+	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2667	+	Node<K,V> hd = null, tl = null;
2668	+	for (Node<K,V> q = b; q != null; q = q.next) {
2669	+	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2670	+	if (tl == null)
2671	+	hd = p;
2672	+	else
2673	+	tl.next = p;
2674	+	tl = p;
2675	+	}
2676	+	return hd;
2677	+	}
2678
2679	<	public boolean hasNext() { return nextEntry != null; }
2679	>	/* ---------------- TreeNodes -------------- */
2680
2681	<	HashEntry<K,V> nextEntry() {
2682	<	if (nextEntry == null)
2683	<	throw new NoSuchElementException();
2684	<	lastReturned = nextEntry;
2681	>	/**
2682	>	* Nodes for use in TreeBins.
2683	>	*/
2684	>	static final class TreeNode<K,V> extends Node<K,V> {
2685	>	TreeNode<K,V> parent;  // red-black tree links
2686	>	TreeNode<K,V> left;
2687	>	TreeNode<K,V> right;
2688	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2689	>	boolean red;
2690	>
2691	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2692	>	TreeNode<K,V> parent) {
2693	>	super(hash, key, val, next);
2694	>	this.parent = parent;
2695	>	}
2696	>
2697	>	Node<K,V> find(int h, Object k) {
2698	>	return findTreeNode(h, k, null);
2699	>	}
2700	>
2701	>	/**
2702	>	* Returns the TreeNode (or null if not found) for the given key
2703	>	* starting at given root.
2704	>	*/
2705	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2706	>	if (k != null) {
2707	>	TreeNode<K,V> p = this;
2708	>	do {
2709	>	int ph, dir; K pk; TreeNode<K,V> q;
2710	>	TreeNode<K,V> pl = p.left, pr = p.right;
2711	>	if ((ph = p.hash) > h)
2712	>	p = pl;
2713	>	else if (ph < h)
2714	>	p = pr;
2715	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2716	>	return p;
2717	>	else if (pl == null)
2718	>	p = pr;
2719	>	else if (pr == null)
2720	>	p = pl;
2721	>	else if ((kc != null ||
2722	>	(kc = comparableClassFor(k)) != null) &&
2723	>	(dir = compareComparables(kc, k, pk)) != 0)
2724	>	p = (dir < 0) ? pl : pr;
2725	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2726	>	return q;
2727	>	else
2728	>	p = pl;
2729	>	} while (p != null);
2730	>	}
2731	>	return null;
2732	>	}
2733	>	}
2734	>
2735	>	/* ---------------- TreeBins -------------- */
2736	>
2737	>	/**
2738	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2739	>	* keys or values, but instead point to list of TreeNodes and
2740	>	* their root. They also maintain a parasitic read-write lock
2741	>	* forcing writers (who hold bin lock) to wait for readers (who do
2742	>	* not) to complete before tree restructuring operations.
2743	>	*/
2744	>	static final class TreeBin<K,V> extends Node<K,V> {
2745	>	TreeNode<K,V> root;
2746	>	volatile TreeNode<K,V> first;
2747	>	volatile Thread waiter;
2748	>	volatile int lockState;
2749	>	// values for lockState
2750	>	static final int WRITER = 1; // set while holding write lock
2751	>	static final int WAITER = 2; // set when waiting for write lock
2752	>	static final int READER = 4; // increment value for setting read lock
2753	>
2754	>	/**
2755	>	* Tie-breaking utility for ordering insertions when equal
2756	>	* hashCodes and non-comparable. We don't require a total
2757	>	* order, just a consistent insertion rule to maintain
2758	>	* equivalence across rebalancings. Tie-breaking further than
2759	>	* necessary simplifies testing a bit.
2760	>	*/
2761	>	static int tieBreakOrder(Object a, Object b) {
2762	>	int d;
2763	>	if (a == null || b == null ||
2764	>	(d = a.getClass().getName().
2765	>	compareTo(b.getClass().getName())) == 0)
2766	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2767	>	-1 : 1);
2768	>	return d;
2769	>	}
2770	>
2771	>	/**
2772	>	* Creates bin with initial set of nodes headed by b.
2773	>	*/
2774	>	TreeBin(TreeNode<K,V> b) {
2775	>	super(TREEBIN, null, null);
2776	>	this.first = b;
2777	>	TreeNode<K,V> r = null;
2778	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2779	>	next = (TreeNode<K,V>)x.next;
2780	>	x.left = x.right = null;
2781	>	if (r == null) {
2782	>	x.parent = null;
2783	>	x.red = false;
2784	>	r = x;
2785	>	}
2786	>	else {
2787	>	K k = x.key;
2788	>	int h = x.hash;
2789	>	Class<?> kc = null;
2790	>	for (TreeNode<K,V> p = r;;) {
2791	>	int dir, ph;
2792	>	K pk = p.key;
2793	>	if ((ph = p.hash) > h)
2794	>	dir = -1;
2795	>	else if (ph < h)
2796	>	dir = 1;
2797	>	else if ((kc == null &&
2798	>	(kc = comparableClassFor(k)) == null) ||
2799	>	(dir = compareComparables(kc, k, pk)) == 0)
2800	>	dir = tieBreakOrder(k, pk);
2801	>	TreeNode<K,V> xp = p;
2802	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2803	>	x.parent = xp;
2804	>	if (dir <= 0)
2805	>	xp.left = x;
2806	>	else
2807	>	xp.right = x;
2808	>	r = balanceInsertion(r, x);
2809	>	break;
2810	>	}
2811	>	}
2812	>	}
2813	>	}
2814	>	this.root = r;
2815	>	assert checkInvariants(root);
2816	>	}
2817	>
2818	>	/**
2819	>	* Acquires write lock for tree restructuring.
2820	>	*/
2821	>	private final void lockRoot() {
2822	>	if (!U.compareAndSetInt(this, LOCKSTATE, 0, WRITER))
2823	>	contendedLock(); // offload to separate method
2824	>	}
2825	>
2826	>	/**
2827	>	* Releases write lock for tree restructuring.
2828	>	*/
2829	>	private final void unlockRoot() {
2830	>	lockState = 0;
2831	>	}
2832	>
2833	>	/**
2834	>	* Possibly blocks awaiting root lock.
2835	>	*/
2836	>	private final void contendedLock() {
2837	>	boolean waiting = false;
2838	>	for (int s;;) {
2839	>	if (((s = lockState) & ~WAITER) == 0) {
2840	>	if (U.compareAndSetInt(this, LOCKSTATE, s, WRITER)) {
2841	>	if (waiting)
2842	>	waiter = null;
2843	>	return;
2844	>	}
2845	>	}
2846	>	else if ((s & WAITER) == 0) {
2847	>	if (U.compareAndSetInt(this, LOCKSTATE, s, s | WAITER)) {
2848	>	waiting = true;
2849	>	waiter = Thread.currentThread();
2850	>	}
2851	>	}
2852	>	else if (waiting)
2853	>	LockSupport.park(this);
2854	>	}
2855	>	}
2856	>
2857	>	/**
2858	>	* Returns matching node or null if none. Tries to search
2859	>	* using tree comparisons from root, but continues linear
2860	>	* search when lock not available.
2861	>	*/
2862	>	final Node<K,V> find(int h, Object k) {
2863	>	if (k != null) {
2864	>	for (Node<K,V> e = first; e != null; ) {
2865	>	int s; K ek;
2866	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2867	>	if (e.hash == h &&
2868	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2869	>	return e;
2870	>	e = e.next;
2871	>	}
2872	>	else if (U.compareAndSetInt(this, LOCKSTATE, s,
2873	>	s + READER)) {
2874	>	TreeNode<K,V> r, p;
2875	>	try {
2876	>	p = ((r = root) == null ? null :
2877	>	r.findTreeNode(h, k, null));
2878	>	} finally {
2879	>	Thread w;
2880	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2881	>	(READER|WAITER) && (w = waiter) != null)
2882	>	LockSupport.unpark(w);
2883	>	}
2884	>	return p;
2885	>	}
2886	>	}
2887	>	}
2888	>	return null;
2889	>	}
2890	>
2891	>	/**
2892	>	* Finds or adds a node.
2893	>	* @return null if added
2894	>	*/
2895	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2896	>	Class<?> kc = null;
2897	>	boolean searched = false;
2898	>	for (TreeNode<K,V> p = root;;) {
2899	>	int dir, ph; K pk;
2900	>	if (p == null) {
2901	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2902	>	break;
2903	>	}
2904	>	else if ((ph = p.hash) > h)
2905	>	dir = -1;
2906	>	else if (ph < h)
2907	>	dir = 1;
2908	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2909	>	return p;
2910	>	else if ((kc == null &&
2911	>	(kc = comparableClassFor(k)) == null) ||
2912	>	(dir = compareComparables(kc, k, pk)) == 0) {
2913	>	if (!searched) {
2914	>	TreeNode<K,V> q, ch;
2915	>	searched = true;
2916	>	if (((ch = p.left) != null &&
2917	>	(q = ch.findTreeNode(h, k, kc)) != null) ||
2918	>	((ch = p.right) != null &&
2919	>	(q = ch.findTreeNode(h, k, kc)) != null))
2920	>	return q;
2921	>	}
2922	>	dir = tieBreakOrder(k, pk);
2923	>	}
2924	>
2925	>	TreeNode<K,V> xp = p;
2926	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2927	>	TreeNode<K,V> x, f = first;
2928	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2929	>	if (f != null)
2930	>	f.prev = x;
2931	>	if (dir <= 0)
2932	>	xp.left = x;
2933	>	else
2934	>	xp.right = x;
2935	>	if (!xp.red)
2936	>	x.red = true;
2937	>	else {
2938	>	lockRoot();
2939	>	try {
2940	>	root = balanceInsertion(root, x);
2941	>	} finally {
2942	>	unlockRoot();
2943	>	}
2944	>	}
2945	>	break;
2946	>	}
2947	>	}
2948	>	assert checkInvariants(root);
2949	>	return null;
2950	>	}
2951	>
2952	>	/**
2953	>	* Removes the given node, that must be present before this
2954	>	* call.  This is messier than typical red-black deletion code
2955	>	* because we cannot swap the contents of an interior node
2956	>	* with a leaf successor that is pinned by "next" pointers
2957	>	* that are accessible independently of lock. So instead we
2958	>	* swap the tree linkages.
2959	>	*
2960	>	* @return true if now too small, so should be untreeified
2961	>	*/
2962	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2963	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2964	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2965	>	TreeNode<K,V> r, rl;
2966	>	if (pred == null)
2967	>	first = next;
2968	>	else
2969	>	pred.next = next;
2970	>	if (next != null)
2971	>	next.prev = pred;
2972	>	if (first == null) {
2973	>	root = null;
2974	>	return true;
2975	>	}
2976	>	if ((r = root) == null || r.right == null || // too small
2977	>	(rl = r.left) == null || rl.left == null)
2978	>	return true;
2979	>	lockRoot();
2980	>	try {
2981	>	TreeNode<K,V> replacement;
2982	>	TreeNode<K,V> pl = p.left;
2983	>	TreeNode<K,V> pr = p.right;
2984	>	if (pl != null && pr != null) {
2985	>	TreeNode<K,V> s = pr, sl;
2986	>	while ((sl = s.left) != null) // find successor
2987	>	s = sl;
2988	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2989	>	TreeNode<K,V> sr = s.right;
2990	>	TreeNode<K,V> pp = p.parent;
2991	>	if (s == pr) { // p was s's direct parent
2992	>	p.parent = s;
2993	>	s.right = p;
2994	>	}
2995	>	else {
2996	>	TreeNode<K,V> sp = s.parent;
2997	>	if ((p.parent = sp) != null) {
2998	>	if (s == sp.left)
2999	>	sp.left = p;
3000	>	else
3001	>	sp.right = p;
3002	>	}
3003	>	if ((s.right = pr) != null)
3004	>	pr.parent = s;
3005	>	}
3006	>	p.left = null;
3007	>	if ((p.right = sr) != null)
3008	>	sr.parent = p;
3009	>	if ((s.left = pl) != null)
3010	>	pl.parent = s;
3011	>	if ((s.parent = pp) == null)
3012	>	r = s;
3013	>	else if (p == pp.left)
3014	>	pp.left = s;
3015	>	else
3016	>	pp.right = s;
3017	>	if (sr != null)
3018	>	replacement = sr;
3019	>	else
3020	>	replacement = p;
3021	>	}
3022	>	else if (pl != null)
3023	>	replacement = pl;
3024	>	else if (pr != null)
3025	>	replacement = pr;
3026	>	else
3027	>	replacement = p;
3028	>	if (replacement != p) {
3029	>	TreeNode<K,V> pp = replacement.parent = p.parent;
3030	>	if (pp == null)
3031	>	r = replacement;
3032	>	else if (p == pp.left)
3033	>	pp.left = replacement;
3034	>	else
3035	>	pp.right = replacement;
3036	>	p.left = p.right = p.parent = null;
3037	>	}
3038	>
3039	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3040	>
3041	>	if (p == replacement) {  // detach pointers
3042	>	TreeNode<K,V> pp;
3043	>	if ((pp = p.parent) != null) {
3044	>	if (p == pp.left)
3045	>	pp.left = null;
3046	>	else if (p == pp.right)
3047	>	pp.right = null;
3048	>	p.parent = null;
3049	>	}
3050	>	}
3051	>	} finally {
3052	>	unlockRoot();
3053	>	}
3054	>	assert checkInvariants(root);
3055	>	return false;
3056	>	}
3057	>
3058	>	/* ------------------------------------------------------------ */
3059	>	// Red-black tree methods, all adapted from CLR
3060	>
3061	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3062	>	TreeNode<K,V> p) {
3063	>	TreeNode<K,V> r, pp, rl;
3064	>	if (p != null && (r = p.right) != null) {
3065	>	if ((rl = p.right = r.left) != null)
3066	>	rl.parent = p;
3067	>	if ((pp = r.parent = p.parent) == null)
3068	>	(root = r).red = false;
3069	>	else if (pp.left == p)
3070	>	pp.left = r;
3071	>	else
3072	>	pp.right = r;
3073	>	r.left = p;
3074	>	p.parent = r;
3075	>	}
3076	>	return root;
3077	>	}
3078	>
3079	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3080	>	TreeNode<K,V> p) {
3081	>	TreeNode<K,V> l, pp, lr;
3082	>	if (p != null && (l = p.left) != null) {
3083	>	if ((lr = p.left = l.right) != null)
3084	>	lr.parent = p;
3085	>	if ((pp = l.parent = p.parent) == null)
3086	>	(root = l).red = false;
3087	>	else if (pp.right == p)
3088	>	pp.right = l;
3089	>	else
3090	>	pp.left = l;
3091	>	l.right = p;
3092	>	p.parent = l;
3093	>	}
3094	>	return root;
3095	>	}
3096	>
3097	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3098	>	TreeNode<K,V> x) {
3099	>	x.red = true;
3100	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3101	>	if ((xp = x.parent) == null) {
3102	>	x.red = false;
3103	>	return x;
3104	>	}
3105	>	else if (!xp.red || (xpp = xp.parent) == null)
3106	>	return root;
3107	>	if (xp == (xppl = xpp.left)) {
3108	>	if ((xppr = xpp.right) != null && xppr.red) {
3109	>	xppr.red = false;
3110	>	xp.red = false;
3111	>	xpp.red = true;
3112	>	x = xpp;
3113	>	}
3114	>	else {
3115	>	if (x == xp.right) {
3116	>	root = rotateLeft(root, x = xp);
3117	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3118	>	}
3119	>	if (xp != null) {
3120	>	xp.red = false;
3121	>	if (xpp != null) {
3122	>	xpp.red = true;
3123	>	root = rotateRight(root, xpp);
3124	>	}
3125	>	}
3126	>	}
3127	>	}
3128	>	else {
3129	>	if (xppl != null && xppl.red) {
3130	>	xppl.red = false;
3131	>	xp.red = false;
3132	>	xpp.red = true;
3133	>	x = xpp;
3134	>	}
3135	>	else {
3136	>	if (x == xp.left) {
3137	>	root = rotateRight(root, x = xp);
3138	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3139	>	}
3140	>	if (xp != null) {
3141	>	xp.red = false;
3142	>	if (xpp != null) {
3143	>	xpp.red = true;
3144	>	root = rotateLeft(root, xpp);
3145	>	}
3146	>	}
3147	>	}
3148	>	}
3149	>	}
3150	>	}
3151	>
3152	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3153	>	TreeNode<K,V> x) {
3154	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3155	>	if (x == null || x == root)
3156	>	return root;
3157	>	else if ((xp = x.parent) == null) {
3158	>	x.red = false;
3159	>	return x;
3160	>	}
3161	>	else if (x.red) {
3162	>	x.red = false;
3163	>	return root;
3164	>	}
3165	>	else if ((xpl = xp.left) == x) {
3166	>	if ((xpr = xp.right) != null && xpr.red) {
3167	>	xpr.red = false;
3168	>	xp.red = true;
3169	>	root = rotateLeft(root, xp);
3170	>	xpr = (xp = x.parent) == null ? null : xp.right;
3171	>	}
3172	>	if (xpr == null)
3173	>	x = xp;
3174	>	else {
3175	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3176	>	if ((sr == null || !sr.red) &&
3177	>	(sl == null || !sl.red)) {
3178	>	xpr.red = true;
3179	>	x = xp;
3180	>	}
3181	>	else {
3182	>	if (sr == null || !sr.red) {
3183	>	if (sl != null)
3184	>	sl.red = false;
3185	>	xpr.red = true;
3186	>	root = rotateRight(root, xpr);
3187	>	xpr = (xp = x.parent) == null ?
3188	>	null : xp.right;
3189	>	}
3190	>	if (xpr != null) {
3191	>	xpr.red = (xp == null) ? false : xp.red;
3192	>	if ((sr = xpr.right) != null)
3193	>	sr.red = false;
3194	>	}
3195	>	if (xp != null) {
3196	>	xp.red = false;
3197	>	root = rotateLeft(root, xp);
3198	>	}
3199	>	x = root;
3200	>	}
3201	>	}
3202	>	}
3203	>	else { // symmetric
3204	>	if (xpl != null && xpl.red) {
3205	>	xpl.red = false;
3206	>	xp.red = true;
3207	>	root = rotateRight(root, xp);
3208	>	xpl = (xp = x.parent) == null ? null : xp.left;
3209	>	}
3210	>	if (xpl == null)
3211	>	x = xp;
3212	>	else {
3213	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3214	>	if ((sl == null || !sl.red) &&
3215	>	(sr == null || !sr.red)) {
3216	>	xpl.red = true;
3217	>	x = xp;
3218	>	}
3219	>	else {
3220	>	if (sl == null || !sl.red) {
3221	>	if (sr != null)
3222	>	sr.red = false;
3223	>	xpl.red = true;
3224	>	root = rotateLeft(root, xpl);
3225	>	xpl = (xp = x.parent) == null ?
3226	>	null : xp.left;
3227	>	}
3228	>	if (xpl != null) {
3229	>	xpl.red = (xp == null) ? false : xp.red;
3230	>	if ((sl = xpl.left) != null)
3231	>	sl.red = false;
3232	>	}
3233	>	if (xp != null) {
3234	>	xp.red = false;
3235	>	root = rotateRight(root, xp);
3236	>	}
3237	>	x = root;
3238	>	}
3239	>	}
3240	>	}
3241	>	}
3242	>	}
3243	>
3244	>	/**
3245	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3246	>	*/
3247	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3248	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3249	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3250	>	if (tb != null && tb.next != t)
3251	>	return false;
3252	>	if (tn != null && tn.prev != t)
3253	>	return false;
3254	>	if (tp != null && t != tp.left && t != tp.right)
3255	>	return false;
3256	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3257	>	return false;
3258	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3259	>	return false;
3260	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3261	>	return false;
3262	>	if (tl != null && !checkInvariants(tl))
3263	>	return false;
3264	>	if (tr != null && !checkInvariants(tr))
3265	>	return false;
3266	>	return true;
3267	>	}
3268	>
3269	>	private static final Unsafe U = Unsafe.getUnsafe();
3270	>	private static final long LOCKSTATE;
3271	>	static {
3272	>	try {
3273	>	LOCKSTATE = U.objectFieldOffset
3274	>	(TreeBin.class.getDeclaredField("lockState"));
3275	>	} catch (ReflectiveOperationException e) {
3276	>	throw new ExceptionInInitializerError(e);
3277	>	}
3278	>	}
3279	>	}
3280	>
3281	>	/* ----------------Table Traversal -------------- */
3282	>
3283	>	/**
3284	>	* Records the table, its length, and current traversal index for a
3285	>	* traverser that must process a region of a forwarded table before
3286	>	* proceeding with current table.
3287	>	*/
3288	>	static final class TableStack<K,V> {
3289	>	int length;
3290	>	int index;
3291	>	Node<K,V>[] tab;
3292	>	TableStack<K,V> next;
3293	>	}
3294	>
3295	>	/**
3296	>	* Encapsulates traversal for methods such as containsValue; also
3297	>	* serves as a base class for other iterators and spliterators.
3298	>	*
3299	>	* Method advance visits once each still-valid node that was
3300	>	* reachable upon iterator construction. It might miss some that
3301	>	* were added to a bin after the bin was visited, which is OK wrt
3302	>	* consistency guarantees. Maintaining this property in the face
3303	>	* of possible ongoing resizes requires a fair amount of
3304	>	* bookkeeping state that is difficult to optimize away amidst
3305	>	* volatile accesses.  Even so, traversal maintains reasonable
3306	>	* throughput.
3307	>	*
3308	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3309	>	* However, if the table has been resized, then all future steps
3310	>	* must traverse both the bin at the current index as well as at
3311	>	* (index + baseSize); and so on for further resizings. To
3312	>	* paranoically cope with potential sharing by users of iterators
3313	>	* across threads, iteration terminates if a bounds checks fails
3314	>	* for a table read.
3315	>	*/
3316	>	static class Traverser<K,V> {
3317	>	Node<K,V>[] tab;        // current table; updated if resized
3318	>	Node<K,V> next;         // the next entry to use
3319	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3320	>	int index;              // index of bin to use next
3321	>	int baseIndex;          // current index of initial table
3322	>	int baseLimit;          // index bound for initial table
3323	>	final int baseSize;     // initial table size
3324	>
3325	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3326	>	this.tab = tab;
3327	>	this.baseSize = size;
3328	>	this.baseIndex = this.index = index;
3329	>	this.baseLimit = limit;
3330	>	this.next = null;
3331	>	}
3332	>
3333	>	/**
3334	>	* Advances if possible, returning next valid node, or null if none.
3335	>	*/
3336	>	final Node<K,V> advance() {
3337	>	Node<K,V> e;
3338	>	if ((e = next) != null)
3339	>	e = e.next;
3340	>	for (;;) {
3341	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3342	>	if (e != null)
3343	>	return next = e;
3344	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3345	>	(n = t.length) <= (i = index) || i < 0)
3346	>	return next = null;
3347	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3348	>	if (e instanceof ForwardingNode) {
3349	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3350	>	e = null;
3351	>	pushState(t, i, n);
3352	>	continue;
3353	>	}
3354	>	else if (e instanceof TreeBin)
3355	>	e = ((TreeBin<K,V>)e).first;
3356	>	else
3357	>	e = null;
3358	>	}
3359	>	if (stack != null)
3360	>	recoverState(n);
3361	>	else if ((index = i + baseSize) >= n)
3362	>	index = ++baseIndex; // visit upper slots if present
3363	>	}
3364	>	}
3365	>
3366	>	/**
3367	>	* Saves traversal state upon encountering a forwarding node.
3368	>	*/
3369	>	private void pushState(Node<K,V>[] t, int i, int n) {
3370	>	TableStack<K,V> s = spare;  // reuse if possible
3371	>	if (s != null)
3372	>	spare = s.next;
3373	>	else
3374	>	s = new TableStack<K,V>();
3375	>	s.tab = t;
3376	>	s.length = n;
3377	>	s.index = i;
3378	>	s.next = stack;
3379	>	stack = s;
3380	>	}
3381	>
3382	>	/**
3383	>	* Possibly pops traversal state.
3384	>	*
3385	>	* @param n length of current table
3386	>	*/
3387	>	private void recoverState(int n) {
3388	>	TableStack<K,V> s; int len;
3389	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3390	>	n = len;
3391	>	index = s.index;
3392	>	tab = s.tab;
3393	>	s.tab = null;
3394	>	TableStack<K,V> next = s.next;
3395	>	s.next = spare; // save for reuse
3396	>	stack = next;
3397	>	spare = s;
3398	>	}
3399	>	if (s == null && (index += baseSize) >= n)
3400	>	index = ++baseIndex;
3401	>	}
3402	>	}
3403	>
3404	>	/**
3405	>	* Base of key, value, and entry Iterators. Adds fields to
3406	>	* Traverser to support iterator.remove.
3407	>	*/
3408	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3409	>	final ConcurrentHashMap<K,V> map;
3410	>	Node<K,V> lastReturned;
3411	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3412	>	ConcurrentHashMap<K,V> map) {
3413	>	super(tab, size, index, limit);
3414	>	this.map = map;
3415		advance();
1098	–	return lastReturned;
3416		}
3417
3418	<	public void remove() {
3419	<	if (lastReturned == null)
3418	>	public final boolean hasNext() { return next != null; }
3419	>	public final boolean hasMoreElements() { return next != null; }
3420	>
3421	>	public final void remove() {
3422	>	Node<K,V> p;
3423	>	if ((p = lastReturned) == null)
3424		throw new IllegalStateException();
1104	–	ConcurrentHashMap.this.remove(lastReturned.key);
3425		lastReturned = null;
3426	+	map.replaceNode(p.key, null, null);
3427		}
3428		}
3429
3430	<	final class KeyIterator
3431	<	extends HashIterator
3432	<	implements Iterator<K>, Enumeration<K>
3433	<	{
3434	<	public K next()        { return super.nextEntry().key; }
3435	<	public K nextElement() { return super.nextEntry().key; }
3430	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3431	>	implements Iterator<K>, Enumeration<K> {
3432	>	KeyIterator(Node<K,V>[] tab, int size, int index, int limit,
3433	>	ConcurrentHashMap<K,V> map) {
3434	>	super(tab, size, index, limit, map);
3435	>	}
3436	>
3437	>	public final K next() {
3438	>	Node<K,V> p;
3439	>	if ((p = next) == null)
3440	>	throw new NoSuchElementException();
3441	>	K k = p.key;
3442	>	lastReturned = p;
3443	>	advance();
3444	>	return k;
3445	>	}
3446	>
3447	>	public final K nextElement() { return next(); }
3448		}
3449
3450	<	final class ValueIterator
3451	<	extends HashIterator
3452	<	implements Iterator<V>, Enumeration<V>
3453	<	{
3454	<	public V next()        { return super.nextEntry().value; }
3455	<	public V nextElement() { return super.nextEntry().value; }
3450	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3451	>	implements Iterator<V>, Enumeration<V> {
3452	>	ValueIterator(Node<K,V>[] tab, int size, int index, int limit,
3453	>	ConcurrentHashMap<K,V> map) {
3454	>	super(tab, size, index, limit, map);
3455	>	}
3456	>
3457	>	public final V next() {
3458	>	Node<K,V> p;
3459	>	if ((p = next) == null)
3460	>	throw new NoSuchElementException();
3461	>	V v = p.val;
3462	>	lastReturned = p;
3463	>	advance();
3464	>	return v;
3465	>	}
3466	>
3467	>	public final V nextElement() { return next(); }
3468	>	}
3469	>
3470	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3471	>	implements Iterator<Map.Entry<K,V>> {
3472	>	EntryIterator(Node<K,V>[] tab, int size, int index, int limit,
3473	>	ConcurrentHashMap<K,V> map) {
3474	>	super(tab, size, index, limit, map);
3475	>	}
3476	>
3477	>	public final Map.Entry<K,V> next() {
3478	>	Node<K,V> p;
3479	>	if ((p = next) == null)
3480	>	throw new NoSuchElementException();
3481	>	K k = p.key;
3482	>	V v = p.val;
3483	>	lastReturned = p;
3484	>	advance();
3485	>	return new MapEntry<K,V>(k, v, map);
3486	>	}
3487		}
3488
3489		/**
3490	<	* Custom Entry class used by EntryIterator.next(), that relays
1127	<	* setValue changes to the underlying map.
3490	>	* Exported Entry for EntryIterator.
3491		*/
3492	<	final class WriteThroughEntry
3493	<	extends AbstractMap.SimpleEntry<K,V>
3494	<	{
3495	<	WriteThroughEntry(K k, V v) {
3496	<	super(k,v);
3492	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3493	>	final K key; // non-null
3494	>	V val;       // non-null
3495	>	final ConcurrentHashMap<K,V> map;
3496	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3497	>	this.key = key;
3498	>	this.val = val;
3499	>	this.map = map;
3500	>	}
3501	>	public K getKey()        { return key; }
3502	>	public V getValue()      { return val; }
3503	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3504	>	public String toString() {
3505	>	return Helpers.mapEntryToString(key, val);
3506	>	}
3507	>
3508	>	public boolean equals(Object o) {
3509	>	Object k, v; Map.Entry<?,?> e;
3510	>	return ((o instanceof Map.Entry) &&
3511	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3512	>	(v = e.getValue()) != null &&
3513	>	(k == key || k.equals(key)) &&
3514	>	(v == val || v.equals(val)));
3515		}
3516
3517		/**
3518	<	* Set our entry's value and write through to the map. The
3519	<	* value to return is somewhat arbitrary here. Since a
3520	<	* WriteThroughEntry does not necessarily track asynchronous
3521	<	* changes, the most recent "previous" value could be
3522	<	* different from what we return (or could even have been
3523	<	* removed in which case the put will re-establish). We do not
1143	<	* and cannot guarantee more.
3518	>	* Sets our entry's value and writes through to the map. The
3519	>	* value to return is somewhat arbitrary here. Since we do not
3520	>	* necessarily track asynchronous changes, the most recent
3521	>	* "previous" value could be different from what we return (or
3522	>	* could even have been removed, in which case the put will
3523	>	* re-establish). We do not and cannot guarantee more.
3524		*/
3525	<	public V setValue(V value) {
3525	>	public V setValue(V value) {
3526		if (value == null) throw new NullPointerException();
3527	<	V v = super.setValue(value);
3528	<	ConcurrentHashMap.this.put(getKey(), value);
3527	>	V v = val;
3528	>	val = value;
3529	>	map.put(key, value);
3530		return v;
3531		}
3532		}
3533
3534	<	final class EntryIterator
3535	<	extends HashIterator
3536	<	implements Iterator<Entry<K,V>>
3537	<	{
3538	<	public Map.Entry<K,V> next() {
3539	<	HashEntry<K,V> e = super.nextEntry();
3540	<	return new WriteThroughEntry(e.key, e.value);
3534	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3535	>	implements Spliterator<K> {
3536	>	long est;               // size estimate
3537	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3538	>	long est) {
3539	>	super(tab, size, index, limit);
3540	>	this.est = est;
3541	>	}
3542	>
3543	>	public KeySpliterator<K,V> trySplit() {
3544	>	int i, f, h;
3545	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3546	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3547	>	f, est >>>= 1);
3548	>	}
3549	>
3550	>	public void forEachRemaining(Consumer<? super K> action) {
3551	>	if (action == null) throw new NullPointerException();
3552	>	for (Node<K,V> p; (p = advance()) != null;)
3553	>	action.accept(p.key);
3554	>	}
3555	>
3556	>	public boolean tryAdvance(Consumer<? super K> action) {
3557	>	if (action == null) throw new NullPointerException();
3558	>	Node<K,V> p;
3559	>	if ((p = advance()) == null)
3560	>	return false;
3561	>	action.accept(p.key);
3562	>	return true;
3563	>	}
3564	>
3565	>	public long estimateSize() { return est; }
3566	>
3567	>	public int characteristics() {
3568	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3569	>	Spliterator.NONNULL;
3570		}
3571		}
3572
3573	<	final class KeySet extends AbstractSet<K> {
3574	<	public Iterator<K> iterator() {
3575	<	return new KeyIterator();
3573	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3574	>	implements Spliterator<V> {
3575	>	long est;               // size estimate
3576	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3577	>	long est) {
3578	>	super(tab, size, index, limit);
3579	>	this.est = est;
3580	>	}
3581	>
3582	>	public ValueSpliterator<K,V> trySplit() {
3583	>	int i, f, h;
3584	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3585	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3586	>	f, est >>>= 1);
3587	>	}
3588	>
3589	>	public void forEachRemaining(Consumer<? super V> action) {
3590	>	if (action == null) throw new NullPointerException();
3591	>	for (Node<K,V> p; (p = advance()) != null;)
3592	>	action.accept(p.val);
3593	>	}
3594	>
3595	>	public boolean tryAdvance(Consumer<? super V> action) {
3596	>	if (action == null) throw new NullPointerException();
3597	>	Node<K,V> p;
3598	>	if ((p = advance()) == null)
3599	>	return false;
3600	>	action.accept(p.val);
3601	>	return true;
3602	>	}
3603	>
3604	>	public long estimateSize() { return est; }
3605	>
3606	>	public int characteristics() {
3607	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3608		}
3609	<	public int size() {
3610	<	return ConcurrentHashMap.this.size();
3609	>	}
3610	>
3611	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3612	>	implements Spliterator<Map.Entry<K,V>> {
3613	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3614	>	long est;               // size estimate
3615	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3616	>	long est, ConcurrentHashMap<K,V> map) {
3617	>	super(tab, size, index, limit);
3618	>	this.map = map;
3619	>	this.est = est;
3620	>	}
3621	>
3622	>	public EntrySpliterator<K,V> trySplit() {
3623	>	int i, f, h;
3624	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3625	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3626	>	f, est >>>= 1, map);
3627	>	}
3628	>
3629	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3630	>	if (action == null) throw new NullPointerException();
3631	>	for (Node<K,V> p; (p = advance()) != null; )
3632	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3633	>	}
3634	>
3635	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3636	>	if (action == null) throw new NullPointerException();
3637	>	Node<K,V> p;
3638	>	if ((p = advance()) == null)
3639	>	return false;
3640	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3641	>	return true;
3642		}
3643	<	public boolean contains(Object o) {
3644	<	return ConcurrentHashMap.this.containsKey(o);
3643	>
3644	>	public long estimateSize() { return est; }
3645	>
3646	>	public int characteristics() {
3647	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3648	>	Spliterator.NONNULL;
3649		}
3650	<	public boolean remove(Object o) {
3651	<	return ConcurrentHashMap.this.remove(o) != null;
3650	>	}
3651	>
3652	>	// Parallel bulk operations
3653	>
3654	>	/**
3655	>	* Computes initial batch value for bulk tasks. The returned value
3656	>	* is approximately exp2 of the number of times (minus one) to
3657	>	* split task by two before executing leaf action. This value is
3658	>	* faster to compute and more convenient to use as a guide to
3659	>	* splitting than is the depth, since it is used while dividing by
3660	>	* two anyway.
3661	>	*/
3662	>	final int batchFor(long b) {
3663	>	long n;
3664	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3665	>	return 0;
3666	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3667	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3668	>	}
3669	>
3670	>	/**
3671	>	* Performs the given action for each (key, value).
3672	>	*
3673	>	* @param parallelismThreshold the (estimated) number of elements
3674	>	* needed for this operation to be executed in parallel
3675	>	* @param action the action
3676	>	* @since 1.8
3677	>	*/
3678	>	public void forEach(long parallelismThreshold,
3679	>	BiConsumer<? super K,? super V> action) {
3680	>	if (action == null) throw new NullPointerException();
3681	>	new ForEachMappingTask<K,V>
3682	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3683	>	action).invoke();
3684	>	}
3685	>
3686	>	/**
3687	>	* Performs the given action for each non-null transformation
3688	>	* of each (key, value).
3689	>	*
3690	>	* @param parallelismThreshold the (estimated) number of elements
3691	>	* needed for this operation to be executed in parallel
3692	>	* @param transformer a function returning the transformation
3693	>	* for an element, or null if there is no transformation (in
3694	>	* which case the action is not applied)
3695	>	* @param action the action
3696	>	* @param <U> the return type of the transformer
3697	>	* @since 1.8
3698	>	*/
3699	>	public <U> void forEach(long parallelismThreshold,
3700	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3701	>	Consumer<? super U> action) {
3702	>	if (transformer == null || action == null)
3703	>	throw new NullPointerException();
3704	>	new ForEachTransformedMappingTask<K,V,U>
3705	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3706	>	transformer, action).invoke();
3707	>	}
3708	>
3709	>	/**
3710	>	* Returns a non-null result from applying the given search
3711	>	* function on each (key, value), or null if none.  Upon
3712	>	* success, further element processing is suppressed and the
3713	>	* results of any other parallel invocations of the search
3714	>	* function are ignored.
3715	>	*
3716	>	* @param parallelismThreshold the (estimated) number of elements
3717	>	* needed for this operation to be executed in parallel
3718	>	* @param searchFunction a function returning a non-null
3719	>	* result on success, else null
3720	>	* @param <U> the return type of the search function
3721	>	* @return a non-null result from applying the given search
3722	>	* function on each (key, value), or null if none
3723	>	* @since 1.8
3724	>	*/
3725	>	public <U> U search(long parallelismThreshold,
3726	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3727	>	if (searchFunction == null) throw new NullPointerException();
3728	>	return new SearchMappingsTask<K,V,U>
3729	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3730	>	searchFunction, new AtomicReference<U>()).invoke();
3731	>	}
3732	>
3733	>	/**
3734	>	* Returns the result of accumulating the given transformation
3735	>	* of all (key, value) pairs using the given reducer to
3736	>	* combine values, or null if none.
3737	>	*
3738	>	* @param parallelismThreshold the (estimated) number of elements
3739	>	* needed for this operation to be executed in parallel
3740	>	* @param transformer a function returning the transformation
3741	>	* for an element, or null if there is no transformation (in
3742	>	* which case it is not combined)
3743	>	* @param reducer a commutative associative combining function
3744	>	* @param <U> the return type of the transformer
3745	>	* @return the result of accumulating the given transformation
3746	>	* of all (key, value) pairs
3747	>	* @since 1.8
3748	>	*/
3749	>	public <U> U reduce(long parallelismThreshold,
3750	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3751	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3752	>	if (transformer == null || reducer == null)
3753	>	throw new NullPointerException();
3754	>	return new MapReduceMappingsTask<K,V,U>
3755	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3756	>	null, transformer, reducer).invoke();
3757	>	}
3758	>
3759	>	/**
3760	>	* Returns the result of accumulating the given transformation
3761	>	* of all (key, value) pairs using the given reducer to
3762	>	* combine values, and the given basis as an identity value.
3763	>	*
3764	>	* @param parallelismThreshold the (estimated) number of elements
3765	>	* needed for this operation to be executed in parallel
3766	>	* @param transformer a function returning the transformation
3767	>	* for an element
3768	>	* @param basis the identity (initial default value) for the reduction
3769	>	* @param reducer a commutative associative combining function
3770	>	* @return the result of accumulating the given transformation
3771	>	* of all (key, value) pairs
3772	>	* @since 1.8
3773	>	*/
3774	>	public double reduceToDouble(long parallelismThreshold,
3775	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3776	>	double basis,
3777	>	DoubleBinaryOperator reducer) {
3778	>	if (transformer == null || reducer == null)
3779	>	throw new NullPointerException();
3780	>	return new MapReduceMappingsToDoubleTask<K,V>
3781	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3782	>	null, transformer, basis, reducer).invoke();
3783	>	}
3784	>
3785	>	/**
3786	>	* Returns the result of accumulating the given transformation
3787	>	* of all (key, value) pairs using the given reducer to
3788	>	* combine values, and the given basis as an identity value.
3789	>	*
3790	>	* @param parallelismThreshold the (estimated) number of elements
3791	>	* needed for this operation to be executed in parallel
3792	>	* @param transformer a function returning the transformation
3793	>	* for an element
3794	>	* @param basis the identity (initial default value) for the reduction
3795	>	* @param reducer a commutative associative combining function
3796	>	* @return the result of accumulating the given transformation
3797	>	* of all (key, value) pairs
3798	>	* @since 1.8
3799	>	*/
3800	>	public long reduceToLong(long parallelismThreshold,
3801	>	ToLongBiFunction<? super K, ? super V> transformer,
3802	>	long basis,
3803	>	LongBinaryOperator reducer) {
3804	>	if (transformer == null || reducer == null)
3805	>	throw new NullPointerException();
3806	>	return new MapReduceMappingsToLongTask<K,V>
3807	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3808	>	null, transformer, basis, reducer).invoke();
3809	>	}
3810	>
3811	>	/**
3812	>	* Returns the result of accumulating the given transformation
3813	>	* of all (key, value) pairs using the given reducer to
3814	>	* combine values, and the given basis as an identity value.
3815	>	*
3816	>	* @param parallelismThreshold the (estimated) number of elements
3817	>	* needed for this operation to be executed in parallel
3818	>	* @param transformer a function returning the transformation
3819	>	* for an element
3820	>	* @param basis the identity (initial default value) for the reduction
3821	>	* @param reducer a commutative associative combining function
3822	>	* @return the result of accumulating the given transformation
3823	>	* of all (key, value) pairs
3824	>	* @since 1.8
3825	>	*/
3826	>	public int reduceToInt(long parallelismThreshold,
3827	>	ToIntBiFunction<? super K, ? super V> transformer,
3828	>	int basis,
3829	>	IntBinaryOperator reducer) {
3830	>	if (transformer == null || reducer == null)
3831	>	throw new NullPointerException();
3832	>	return new MapReduceMappingsToIntTask<K,V>
3833	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3834	>	null, transformer, basis, reducer).invoke();
3835	>	}
3836	>
3837	>	/**
3838	>	* Performs the given action for each key.
3839	>	*
3840	>	* @param parallelismThreshold the (estimated) number of elements
3841	>	* needed for this operation to be executed in parallel
3842	>	* @param action the action
3843	>	* @since 1.8
3844	>	*/
3845	>	public void forEachKey(long parallelismThreshold,
3846	>	Consumer<? super K> action) {
3847	>	if (action == null) throw new NullPointerException();
3848	>	new ForEachKeyTask<K,V>
3849	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3850	>	action).invoke();
3851	>	}
3852	>
3853	>	/**
3854	>	* Performs the given action for each non-null transformation
3855	>	* of each key.
3856	>	*
3857	>	* @param parallelismThreshold the (estimated) number of elements
3858	>	* needed for this operation to be executed in parallel
3859	>	* @param transformer a function returning the transformation
3860	>	* for an element, or null if there is no transformation (in
3861	>	* which case the action is not applied)
3862	>	* @param action the action
3863	>	* @param <U> the return type of the transformer
3864	>	* @since 1.8
3865	>	*/
3866	>	public <U> void forEachKey(long parallelismThreshold,
3867	>	Function<? super K, ? extends U> transformer,
3868	>	Consumer<? super U> action) {
3869	>	if (transformer == null || action == null)
3870	>	throw new NullPointerException();
3871	>	new ForEachTransformedKeyTask<K,V,U>
3872	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3873	>	transformer, action).invoke();
3874	>	}
3875	>
3876	>	/**
3877	>	* Returns a non-null result from applying the given search
3878	>	* function on each key, or null if none. Upon success,
3879	>	* further element processing is suppressed and the results of
3880	>	* any other parallel invocations of the search function are
3881	>	* ignored.
3882	>	*
3883	>	* @param parallelismThreshold the (estimated) number of elements
3884	>	* needed for this operation to be executed in parallel
3885	>	* @param searchFunction a function returning a non-null
3886	>	* result on success, else null
3887	>	* @param <U> the return type of the search function
3888	>	* @return a non-null result from applying the given search
3889	>	* function on each key, or null if none
3890	>	* @since 1.8
3891	>	*/
3892	>	public <U> U searchKeys(long parallelismThreshold,
3893	>	Function<? super K, ? extends U> searchFunction) {
3894	>	if (searchFunction == null) throw new NullPointerException();
3895	>	return new SearchKeysTask<K,V,U>
3896	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3897	>	searchFunction, new AtomicReference<U>()).invoke();
3898	>	}
3899	>
3900	>	/**
3901	>	* Returns the result of accumulating all keys using the given
3902	>	* reducer to combine values, or null if none.
3903	>	*
3904	>	* @param parallelismThreshold the (estimated) number of elements
3905	>	* needed for this operation to be executed in parallel
3906	>	* @param reducer a commutative associative combining function
3907	>	* @return the result of accumulating all keys using the given
3908	>	* reducer to combine values, or null if none
3909	>	* @since 1.8
3910	>	*/
3911	>	public K reduceKeys(long parallelismThreshold,
3912	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3913	>	if (reducer == null) throw new NullPointerException();
3914	>	return new ReduceKeysTask<K,V>
3915	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3916	>	null, reducer).invoke();
3917	>	}
3918	>
3919	>	/**
3920	>	* Returns the result of accumulating the given transformation
3921	>	* of all keys using the given reducer to combine values, or
3922	>	* null if none.
3923	>	*
3924	>	* @param parallelismThreshold the (estimated) number of elements
3925	>	* needed for this operation to be executed in parallel
3926	>	* @param transformer a function returning the transformation
3927	>	* for an element, or null if there is no transformation (in
3928	>	* which case it is not combined)
3929	>	* @param reducer a commutative associative combining function
3930	>	* @param <U> the return type of the transformer
3931	>	* @return the result of accumulating the given transformation
3932	>	* of all keys
3933	>	* @since 1.8
3934	>	*/
3935	>	public <U> U reduceKeys(long parallelismThreshold,
3936	>	Function<? super K, ? extends U> transformer,
3937	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3938	>	if (transformer == null || reducer == null)
3939	>	throw new NullPointerException();
3940	>	return new MapReduceKeysTask<K,V,U>
3941	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3942	>	null, transformer, reducer).invoke();
3943	>	}
3944	>
3945	>	/**
3946	>	* Returns the result of accumulating the given transformation
3947	>	* of all keys using the given reducer to combine values, and
3948	>	* the given basis as an identity value.
3949	>	*
3950	>	* @param parallelismThreshold the (estimated) number of elements
3951	>	* needed for this operation to be executed in parallel
3952	>	* @param transformer a function returning the transformation
3953	>	* for an element
3954	>	* @param basis the identity (initial default value) for the reduction
3955	>	* @param reducer a commutative associative combining function
3956	>	* @return the result of accumulating the given transformation
3957	>	* of all keys
3958	>	* @since 1.8
3959	>	*/
3960	>	public double reduceKeysToDouble(long parallelismThreshold,
3961	>	ToDoubleFunction<? super K> transformer,
3962	>	double basis,
3963	>	DoubleBinaryOperator reducer) {
3964	>	if (transformer == null || reducer == null)
3965	>	throw new NullPointerException();
3966	>	return new MapReduceKeysToDoubleTask<K,V>
3967	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3968	>	null, transformer, basis, reducer).invoke();
3969	>	}
3970	>
3971	>	/**
3972	>	* Returns the result of accumulating the given transformation
3973	>	* of all keys using the given reducer to combine values, and
3974	>	* the given basis as an identity value.
3975	>	*
3976	>	* @param parallelismThreshold the (estimated) number of elements
3977	>	* needed for this operation to be executed in parallel
3978	>	* @param transformer a function returning the transformation
3979	>	* for an element
3980	>	* @param basis the identity (initial default value) for the reduction
3981	>	* @param reducer a commutative associative combining function
3982	>	* @return the result of accumulating the given transformation
3983	>	* of all keys
3984	>	* @since 1.8
3985	>	*/
3986	>	public long reduceKeysToLong(long parallelismThreshold,
3987	>	ToLongFunction<? super K> transformer,
3988	>	long basis,
3989	>	LongBinaryOperator reducer) {
3990	>	if (transformer == null || reducer == null)
3991	>	throw new NullPointerException();
3992	>	return new MapReduceKeysToLongTask<K,V>
3993	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3994	>	null, transformer, basis, reducer).invoke();
3995	>	}
3996	>
3997	>	/**
3998	>	* Returns the result of accumulating the given transformation
3999	>	* of all keys using the given reducer to combine values, and
4000	>	* the given basis as an identity value.
4001	>	*
4002	>	* @param parallelismThreshold the (estimated) number of elements
4003	>	* needed for this operation to be executed in parallel
4004	>	* @param transformer a function returning the transformation
4005	>	* for an element
4006	>	* @param basis the identity (initial default value) for the reduction
4007	>	* @param reducer a commutative associative combining function
4008	>	* @return the result of accumulating the given transformation
4009	>	* of all keys
4010	>	* @since 1.8
4011	>	*/
4012	>	public int reduceKeysToInt(long parallelismThreshold,
4013	>	ToIntFunction<? super K> transformer,
4014	>	int basis,
4015	>	IntBinaryOperator reducer) {
4016	>	if (transformer == null || reducer == null)
4017	>	throw new NullPointerException();
4018	>	return new MapReduceKeysToIntTask<K,V>
4019	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4020	>	null, transformer, basis, reducer).invoke();
4021	>	}
4022	>
4023	>	/**
4024	>	* Performs the given action for each value.
4025	>	*
4026	>	* @param parallelismThreshold the (estimated) number of elements
4027	>	* needed for this operation to be executed in parallel
4028	>	* @param action the action
4029	>	* @since 1.8
4030	>	*/
4031	>	public void forEachValue(long parallelismThreshold,
4032	>	Consumer<? super V> action) {
4033	>	if (action == null)
4034	>	throw new NullPointerException();
4035	>	new ForEachValueTask<K,V>
4036	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4037	>	action).invoke();
4038	>	}
4039	>
4040	>	/**
4041	>	* Performs the given action for each non-null transformation
4042	>	* of each value.
4043	>	*
4044	>	* @param parallelismThreshold the (estimated) number of elements
4045	>	* needed for this operation to be executed in parallel
4046	>	* @param transformer a function returning the transformation
4047	>	* for an element, or null if there is no transformation (in
4048	>	* which case the action is not applied)
4049	>	* @param action the action
4050	>	* @param <U> the return type of the transformer
4051	>	* @since 1.8
4052	>	*/
4053	>	public <U> void forEachValue(long parallelismThreshold,
4054	>	Function<? super V, ? extends U> transformer,
4055	>	Consumer<? super U> action) {
4056	>	if (transformer == null || action == null)
4057	>	throw new NullPointerException();
4058	>	new ForEachTransformedValueTask<K,V,U>
4059	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4060	>	transformer, action).invoke();
4061	>	}
4062	>
4063	>	/**
4064	>	* Returns a non-null result from applying the given search
4065	>	* function on each value, or null if none.  Upon success,
4066	>	* further element processing is suppressed and the results of
4067	>	* any other parallel invocations of the search function are
4068	>	* ignored.
4069	>	*
4070	>	* @param parallelismThreshold the (estimated) number of elements
4071	>	* needed for this operation to be executed in parallel
4072	>	* @param searchFunction a function returning a non-null
4073	>	* result on success, else null
4074	>	* @param <U> the return type of the search function
4075	>	* @return a non-null result from applying the given search
4076	>	* function on each value, or null if none
4077	>	* @since 1.8
4078	>	*/
4079	>	public <U> U searchValues(long parallelismThreshold,
4080	>	Function<? super V, ? extends U> searchFunction) {
4081	>	if (searchFunction == null) throw new NullPointerException();
4082	>	return new SearchValuesTask<K,V,U>
4083	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4084	>	searchFunction, new AtomicReference<U>()).invoke();
4085	>	}
4086	>
4087	>	/**
4088	>	* Returns the result of accumulating all values using the
4089	>	* given reducer to combine values, or null if none.
4090	>	*
4091	>	* @param parallelismThreshold the (estimated) number of elements
4092	>	* needed for this operation to be executed in parallel
4093	>	* @param reducer a commutative associative combining function
4094	>	* @return the result of accumulating all values
4095	>	* @since 1.8
4096	>	*/
4097	>	public V reduceValues(long parallelismThreshold,
4098	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4099	>	if (reducer == null) throw new NullPointerException();
4100	>	return new ReduceValuesTask<K,V>
4101	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4102	>	null, reducer).invoke();
4103	>	}
4104	>
4105	>	/**
4106	>	* Returns the result of accumulating the given transformation
4107	>	* of all values using the given reducer to combine values, or
4108	>	* null if none.
4109	>	*
4110	>	* @param parallelismThreshold the (estimated) number of elements
4111	>	* needed for this operation to be executed in parallel
4112	>	* @param transformer a function returning the transformation
4113	>	* for an element, or null if there is no transformation (in
4114	>	* which case it is not combined)
4115	>	* @param reducer a commutative associative combining function
4116	>	* @param <U> the return type of the transformer
4117	>	* @return the result of accumulating the given transformation
4118	>	* of all values
4119	>	* @since 1.8
4120	>	*/
4121	>	public <U> U reduceValues(long parallelismThreshold,
4122	>	Function<? super V, ? extends U> transformer,
4123	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4124	>	if (transformer == null || reducer == null)
4125	>	throw new NullPointerException();
4126	>	return new MapReduceValuesTask<K,V,U>
4127	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4128	>	null, transformer, reducer).invoke();
4129	>	}
4130	>
4131	>	/**
4132	>	* Returns the result of accumulating the given transformation
4133	>	* of all values using the given reducer to combine values,
4134	>	* and the given basis as an identity value.
4135	>	*
4136	>	* @param parallelismThreshold the (estimated) number of elements
4137	>	* needed for this operation to be executed in parallel
4138	>	* @param transformer a function returning the transformation
4139	>	* for an element
4140	>	* @param basis the identity (initial default value) for the reduction
4141	>	* @param reducer a commutative associative combining function
4142	>	* @return the result of accumulating the given transformation
4143	>	* of all values
4144	>	* @since 1.8
4145	>	*/
4146	>	public double reduceValuesToDouble(long parallelismThreshold,
4147	>	ToDoubleFunction<? super V> transformer,
4148	>	double basis,
4149	>	DoubleBinaryOperator reducer) {
4150	>	if (transformer == null || reducer == null)
4151	>	throw new NullPointerException();
4152	>	return new MapReduceValuesToDoubleTask<K,V>
4153	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4154	>	null, transformer, basis, reducer).invoke();
4155	>	}
4156	>
4157	>	/**
4158	>	* Returns the result of accumulating the given transformation
4159	>	* of all values using the given reducer to combine values,
4160	>	* and the given basis as an identity value.
4161	>	*
4162	>	* @param parallelismThreshold the (estimated) number of elements
4163	>	* needed for this operation to be executed in parallel
4164	>	* @param transformer a function returning the transformation
4165	>	* for an element
4166	>	* @param basis the identity (initial default value) for the reduction
4167	>	* @param reducer a commutative associative combining function
4168	>	* @return the result of accumulating the given transformation
4169	>	* of all values
4170	>	* @since 1.8
4171	>	*/
4172	>	public long reduceValuesToLong(long parallelismThreshold,
4173	>	ToLongFunction<? super V> transformer,
4174	>	long basis,
4175	>	LongBinaryOperator reducer) {
4176	>	if (transformer == null || reducer == null)
4177	>	throw new NullPointerException();
4178	>	return new MapReduceValuesToLongTask<K,V>
4179	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4180	>	null, transformer, basis, reducer).invoke();
4181	>	}
4182	>
4183	>	/**
4184	>	* Returns the result of accumulating the given transformation
4185	>	* of all values using the given reducer to combine values,
4186	>	* and the given basis as an identity value.
4187	>	*
4188	>	* @param parallelismThreshold the (estimated) number of elements
4189	>	* needed for this operation to be executed in parallel
4190	>	* @param transformer a function returning the transformation
4191	>	* for an element
4192	>	* @param basis the identity (initial default value) for the reduction
4193	>	* @param reducer a commutative associative combining function
4194	>	* @return the result of accumulating the given transformation
4195	>	* of all values
4196	>	* @since 1.8
4197	>	*/
4198	>	public int reduceValuesToInt(long parallelismThreshold,
4199	>	ToIntFunction<? super V> transformer,
4200	>	int basis,
4201	>	IntBinaryOperator reducer) {
4202	>	if (transformer == null || reducer == null)
4203	>	throw new NullPointerException();
4204	>	return new MapReduceValuesToIntTask<K,V>
4205	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4206	>	null, transformer, basis, reducer).invoke();
4207	>	}
4208	>
4209	>	/**
4210	>	* Performs the given action for each entry.
4211	>	*
4212	>	* @param parallelismThreshold the (estimated) number of elements
4213	>	* needed for this operation to be executed in parallel
4214	>	* @param action the action
4215	>	* @since 1.8
4216	>	*/
4217	>	public void forEachEntry(long parallelismThreshold,
4218	>	Consumer<? super Map.Entry<K,V>> action) {
4219	>	if (action == null) throw new NullPointerException();
4220	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4221	>	action).invoke();
4222	>	}
4223	>
4224	>	/**
4225	>	* Performs the given action for each non-null transformation
4226	>	* of each entry.
4227	>	*
4228	>	* @param parallelismThreshold the (estimated) number of elements
4229	>	* needed for this operation to be executed in parallel
4230	>	* @param transformer a function returning the transformation
4231	>	* for an element, or null if there is no transformation (in
4232	>	* which case the action is not applied)
4233	>	* @param action the action
4234	>	* @param <U> the return type of the transformer
4235	>	* @since 1.8
4236	>	*/
4237	>	public <U> void forEachEntry(long parallelismThreshold,
4238	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4239	>	Consumer<? super U> action) {
4240	>	if (transformer == null || action == null)
4241	>	throw new NullPointerException();
4242	>	new ForEachTransformedEntryTask<K,V,U>
4243	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4244	>	transformer, action).invoke();
4245	>	}
4246	>
4247	>	/**
4248	>	* Returns a non-null result from applying the given search
4249	>	* function on each entry, or null if none.  Upon success,
4250	>	* further element processing is suppressed and the results of
4251	>	* any other parallel invocations of the search function are
4252	>	* ignored.
4253	>	*
4254	>	* @param parallelismThreshold the (estimated) number of elements
4255	>	* needed for this operation to be executed in parallel
4256	>	* @param searchFunction a function returning a non-null
4257	>	* result on success, else null
4258	>	* @param <U> the return type of the search function
4259	>	* @return a non-null result from applying the given search
4260	>	* function on each entry, or null if none
4261	>	* @since 1.8
4262	>	*/
4263	>	public <U> U searchEntries(long parallelismThreshold,
4264	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4265	>	if (searchFunction == null) throw new NullPointerException();
4266	>	return new SearchEntriesTask<K,V,U>
4267	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4268	>	searchFunction, new AtomicReference<U>()).invoke();
4269	>	}
4270	>
4271	>	/**
4272	>	* Returns the result of accumulating all entries using the
4273	>	* given reducer to combine values, or null if none.
4274	>	*
4275	>	* @param parallelismThreshold the (estimated) number of elements
4276	>	* needed for this operation to be executed in parallel
4277	>	* @param reducer a commutative associative combining function
4278	>	* @return the result of accumulating all entries
4279	>	* @since 1.8
4280	>	*/
4281	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4282	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4283	>	if (reducer == null) throw new NullPointerException();
4284	>	return new ReduceEntriesTask<K,V>
4285	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4286	>	null, reducer).invoke();
4287	>	}
4288	>
4289	>	/**
4290	>	* Returns the result of accumulating the given transformation
4291	>	* of all entries using the given reducer to combine values,
4292	>	* or null if none.
4293	>	*
4294	>	* @param parallelismThreshold the (estimated) number of elements
4295	>	* needed for this operation to be executed in parallel
4296	>	* @param transformer a function returning the transformation
4297	>	* for an element, or null if there is no transformation (in
4298	>	* which case it is not combined)
4299	>	* @param reducer a commutative associative combining function
4300	>	* @param <U> the return type of the transformer
4301	>	* @return the result of accumulating the given transformation
4302	>	* of all entries
4303	>	* @since 1.8
4304	>	*/
4305	>	public <U> U reduceEntries(long parallelismThreshold,
4306	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4307	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4308	>	if (transformer == null || reducer == null)
4309	>	throw new NullPointerException();
4310	>	return new MapReduceEntriesTask<K,V,U>
4311	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4312	>	null, transformer, reducer).invoke();
4313	>	}
4314	>
4315	>	/**
4316	>	* Returns the result of accumulating the given transformation
4317	>	* of all entries using the given reducer to combine values,
4318	>	* and the given basis as an identity value.
4319	>	*
4320	>	* @param parallelismThreshold the (estimated) number of elements
4321	>	* needed for this operation to be executed in parallel
4322	>	* @param transformer a function returning the transformation
4323	>	* for an element
4324	>	* @param basis the identity (initial default value) for the reduction
4325	>	* @param reducer a commutative associative combining function
4326	>	* @return the result of accumulating the given transformation
4327	>	* of all entries
4328	>	* @since 1.8
4329	>	*/
4330	>	public double reduceEntriesToDouble(long parallelismThreshold,
4331	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4332	>	double basis,
4333	>	DoubleBinaryOperator reducer) {
4334	>	if (transformer == null || reducer == null)
4335	>	throw new NullPointerException();
4336	>	return new MapReduceEntriesToDoubleTask<K,V>
4337	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4338	>	null, transformer, basis, reducer).invoke();
4339	>	}
4340	>
4341	>	/**
4342	>	* Returns the result of accumulating the given transformation
4343	>	* of all entries using the given reducer to combine values,
4344	>	* and the given basis as an identity value.
4345	>	*
4346	>	* @param parallelismThreshold the (estimated) number of elements
4347	>	* needed for this operation to be executed in parallel
4348	>	* @param transformer a function returning the transformation
4349	>	* for an element
4350	>	* @param basis the identity (initial default value) for the reduction
4351	>	* @param reducer a commutative associative combining function
4352	>	* @return the result of accumulating the given transformation
4353	>	* of all entries
4354	>	* @since 1.8
4355	>	*/
4356	>	public long reduceEntriesToLong(long parallelismThreshold,
4357	>	ToLongFunction<Map.Entry<K,V>> transformer,
4358	>	long basis,
4359	>	LongBinaryOperator reducer) {
4360	>	if (transformer == null || reducer == null)
4361	>	throw new NullPointerException();
4362	>	return new MapReduceEntriesToLongTask<K,V>
4363	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4364	>	null, transformer, basis, reducer).invoke();
4365	>	}
4366	>
4367	>	/**
4368	>	* Returns the result of accumulating the given transformation
4369	>	* of all entries using the given reducer to combine values,
4370	>	* and the given basis as an identity value.
4371	>	*
4372	>	* @param parallelismThreshold the (estimated) number of elements
4373	>	* needed for this operation to be executed in parallel
4374	>	* @param transformer a function returning the transformation
4375	>	* for an element
4376	>	* @param basis the identity (initial default value) for the reduction
4377	>	* @param reducer a commutative associative combining function
4378	>	* @return the result of accumulating the given transformation
4379	>	* of all entries
4380	>	* @since 1.8
4381	>	*/
4382	>	public int reduceEntriesToInt(long parallelismThreshold,
4383	>	ToIntFunction<Map.Entry<K,V>> transformer,
4384	>	int basis,
4385	>	IntBinaryOperator reducer) {
4386	>	if (transformer == null || reducer == null)
4387	>	throw new NullPointerException();
4388	>	return new MapReduceEntriesToIntTask<K,V>
4389	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4390	>	null, transformer, basis, reducer).invoke();
4391	>	}
4392	>
4393	>
4394	>	/* ----------------Views -------------- */
4395	>
4396	>	/**
4397	>	* Base class for views.
4398	>	*/
4399	>	abstract static class CollectionView<K,V,E>
4400	>	implements Collection<E>, java.io.Serializable {
4401	>	private static final long serialVersionUID = 7249069246763182397L;
4402	>	final ConcurrentHashMap<K,V> map;
4403	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4404	>
4405	>	/**
4406	>	* Returns the map backing this view.
4407	>	*
4408	>	* @return the map backing this view
4409	>	*/
4410	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4411	>
4412	>	/**
4413	>	* Removes all of the elements from this view, by removing all
4414	>	* the mappings from the map backing this view.
4415	>	*/
4416	>	public final void clear()      { map.clear(); }
4417	>	public final int size()        { return map.size(); }
4418	>	public final boolean isEmpty() { return map.isEmpty(); }
4419	>
4420	>	// implementations below rely on concrete classes supplying these
4421	>	// abstract methods
4422	>	/**
4423	>	* Returns an iterator over the elements in this collection.
4424	>	*
4425	>	* <p>The returned iterator is
4426	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4427	>	*
4428	>	* @return an iterator over the elements in this collection
4429	>	*/
4430	>	public abstract Iterator<E> iterator();
4431	>	public abstract boolean contains(Object o);
4432	>	public abstract boolean remove(Object o);
4433	>
4434	>	private static final String OOME_MSG = "Required array size too large";
4435	>
4436	>	public final Object[] toArray() {
4437	>	long sz = map.mappingCount();
4438	>	if (sz > MAX_ARRAY_SIZE)
4439	>	throw new OutOfMemoryError(OOME_MSG);
4440	>	int n = (int)sz;
4441	>	Object[] r = new Object[n];
4442	>	int i = 0;
4443	>	for (E e : this) {
4444	>	if (i == n) {
4445	>	if (n >= MAX_ARRAY_SIZE)
4446	>	throw new OutOfMemoryError(OOME_MSG);
4447	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4448	>	n = MAX_ARRAY_SIZE;
4449	>	else
4450	>	n += (n >>> 1) + 1;
4451	>	r = Arrays.copyOf(r, n);
4452	>	}
4453	>	r[i++] = e;
4454	>	}
4455	>	return (i == n) ? r : Arrays.copyOf(r, i);
4456		}
4457	<	public void clear() {
4458	<	ConcurrentHashMap.this.clear();
4457	>
4458	>	@SuppressWarnings("unchecked")
4459	>	public final <T> T[] toArray(T[] a) {
4460	>	long sz = map.mappingCount();
4461	>	if (sz > MAX_ARRAY_SIZE)
4462	>	throw new OutOfMemoryError(OOME_MSG);
4463	>	int m = (int)sz;
4464	>	T[] r = (a.length >= m) ? a :
4465	>	(T[])java.lang.reflect.Array
4466	>	.newInstance(a.getClass().getComponentType(), m);
4467	>	int n = r.length;
4468	>	int i = 0;
4469	>	for (E e : this) {
4470	>	if (i == n) {
4471	>	if (n >= MAX_ARRAY_SIZE)
4472	>	throw new OutOfMemoryError(OOME_MSG);
4473	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4474	>	n = MAX_ARRAY_SIZE;
4475	>	else
4476	>	n += (n >>> 1) + 1;
4477	>	r = Arrays.copyOf(r, n);
4478	>	}
4479	>	r[i++] = (T)e;
4480	>	}
4481	>	if (a == r && i < n) {
4482	>	r[i] = null; // null-terminate
4483	>	return r;
4484	>	}
4485	>	return (i == n) ? r : Arrays.copyOf(r, i);
4486		}
4487	+
4488	+	/**
4489	+	* Returns a string representation of this collection.
4490	+	* The string representation consists of the string representations
4491	+	* of the collection's elements in the order they are returned by
4492	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4493	+	* Adjacent elements are separated by the characters {@code ", "}
4494	+	* (comma and space).  Elements are converted to strings as by
4495	+	* {@link String#valueOf(Object)}.
4496	+	*
4497	+	* @return a string representation of this collection
4498	+	*/
4499	+	public final String toString() {
4500	+	StringBuilder sb = new StringBuilder();
4501	+	sb.append('[');
4502	+	Iterator<E> it = iterator();
4503	+	if (it.hasNext()) {
4504	+	for (;;) {
4505	+	Object e = it.next();
4506	+	sb.append(e == this ? "(this Collection)" : e);
4507	+	if (!it.hasNext())
4508	+	break;
4509	+	sb.append(',').append(' ');
4510	+	}
4511	+	}
4512	+	return sb.append(']').toString();
4513	+	}
4514	+
4515	+	public final boolean containsAll(Collection<?> c) {
4516	+	if (c != this) {
4517	+	for (Object e : c) {
4518	+	if (e == null || !contains(e))
4519	+	return false;
4520	+	}
4521	+	}
4522	+	return true;
4523	+	}
4524	+
4525	+	public boolean removeAll(Collection<?> c) {
4526	+	if (c == null) throw new NullPointerException();
4527	+	boolean modified = false;
4528	+	// Use (c instanceof Set) as a hint that lookup in c is as
4529	+	// efficient as this view
4530	+	Node<K,V>[] t;
4531	+	if ((t = map.table) == null) {
4532	+	return false;
4533	+	} else if (c instanceof Set<?> && c.size() > t.length) {
4534	+	for (Iterator<?> it = iterator(); it.hasNext(); ) {
4535	+	if (c.contains(it.next())) {
4536	+	it.remove();
4537	+	modified = true;
4538	+	}
4539	+	}
4540	+	} else {
4541	+	for (Object e : c)
4542	+	modified |= remove(e);
4543	+	}
4544	+	return modified;
4545	+	}
4546	+
4547	+	public final boolean retainAll(Collection<?> c) {
4548	+	if (c == null) throw new NullPointerException();
4549	+	boolean modified = false;
4550	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4551	+	if (!c.contains(it.next())) {
4552	+	it.remove();
4553	+	modified = true;
4554	+	}
4555	+	}
4556	+	return modified;
4557	+	}
4558	+
4559		}
4560
4561	<	final class Values extends AbstractCollection<V> {
4562	<	public Iterator<V> iterator() {
4563	<	return new ValueIterator();
4561	>	/**
4562	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4563	>	* which additions may optionally be enabled by mapping to a
4564	>	* common value.  This class cannot be directly instantiated.
4565	>	* See {@link #keySet() keySet()},
4566	>	* {@link #keySet(Object) keySet(V)},
4567	>	* {@link #newKeySet() newKeySet()},
4568	>	* {@link #newKeySet(int) newKeySet(int)}.
4569	>	*
4570	>	* @since 1.8
4571	>	*/
4572	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4573	>	implements Set<K>, java.io.Serializable {
4574	>	private static final long serialVersionUID = 7249069246763182397L;
4575	>	private final V value;
4576	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4577	>	super(map);
4578	>	this.value = value;
4579		}
4580	<	public int size() {
4581	<	return ConcurrentHashMap.this.size();
4580	>
4581	>	/**
4582	>	* Returns the default mapped value for additions,
4583	>	* or {@code null} if additions are not supported.
4584	>	*
4585	>	* @return the default mapped value for additions, or {@code null}
4586	>	* if not supported
4587	>	*/
4588	>	public V getMappedValue() { return value; }
4589	>
4590	>	/**
4591	>	* {@inheritDoc}
4592	>	* @throws NullPointerException if the specified key is null
4593	>	*/
4594	>	public boolean contains(Object o) { return map.containsKey(o); }
4595	>
4596	>	/**
4597	>	* Removes the key from this map view, by removing the key (and its
4598	>	* corresponding value) from the backing map.  This method does
4599	>	* nothing if the key is not in the map.
4600	>	*
4601	>	* @param  o the key to be removed from the backing map
4602	>	* @return {@code true} if the backing map contained the specified key
4603	>	* @throws NullPointerException if the specified key is null
4604	>	*/
4605	>	public boolean remove(Object o) { return map.remove(o) != null; }
4606	>
4607	>	/**
4608	>	* @return an iterator over the keys of the backing map
4609	>	*/
4610	>	public Iterator<K> iterator() {
4611	>	Node<K,V>[] t;
4612	>	ConcurrentHashMap<K,V> m = map;
4613	>	int f = (t = m.table) == null ? 0 : t.length;
4614	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4615		}
4616	<	public boolean contains(Object o) {
4617	<	return ConcurrentHashMap.this.containsValue(o);
4616	>
4617	>	/**
4618	>	* Adds the specified key to this set view by mapping the key to
4619	>	* the default mapped value in the backing map, if defined.
4620	>	*
4621	>	* @param e key to be added
4622	>	* @return {@code true} if this set changed as a result of the call
4623	>	* @throws NullPointerException if the specified key is null
4624	>	* @throws UnsupportedOperationException if no default mapped value
4625	>	* for additions was provided
4626	>	*/
4627	>	public boolean add(K e) {
4628	>	V v;
4629	>	if ((v = value) == null)
4630	>	throw new UnsupportedOperationException();
4631	>	return map.putVal(e, v, true) == null;
4632	>	}
4633	>
4634	>	/**
4635	>	* Adds all of the elements in the specified collection to this set,
4636	>	* as if by calling {@link #add} on each one.
4637	>	*
4638	>	* @param c the elements to be inserted into this set
4639	>	* @return {@code true} if this set changed as a result of the call
4640	>	* @throws NullPointerException if the collection or any of its
4641	>	* elements are {@code null}
4642	>	* @throws UnsupportedOperationException if no default mapped value
4643	>	* for additions was provided
4644	>	*/
4645	>	public boolean addAll(Collection<? extends K> c) {
4646	>	boolean added = false;
4647	>	V v;
4648	>	if ((v = value) == null)
4649	>	throw new UnsupportedOperationException();
4650	>	for (K e : c) {
4651	>	if (map.putVal(e, v, true) == null)
4652	>	added = true;
4653	>	}
4654	>	return added;
4655		}
4656	<	public void clear() {
4657	<	ConcurrentHashMap.this.clear();
4656	>
4657	>	public int hashCode() {
4658	>	int h = 0;
4659	>	for (K e : this)
4660	>	h += e.hashCode();
4661	>	return h;
4662	>	}
4663	>
4664	>	public boolean equals(Object o) {
4665	>	Set<?> c;
4666	>	return ((o instanceof Set) &&
4667	>	((c = (Set<?>)o) == this ||
4668	>	(containsAll(c) && c.containsAll(this))));
4669	>	}
4670	>
4671	>	public Spliterator<K> spliterator() {
4672	>	Node<K,V>[] t;
4673	>	ConcurrentHashMap<K,V> m = map;
4674	>	long n = m.sumCount();
4675	>	int f = (t = m.table) == null ? 0 : t.length;
4676	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4677	>	}
4678	>
4679	>	public void forEach(Consumer<? super K> action) {
4680	>	if (action == null) throw new NullPointerException();
4681	>	Node<K,V>[] t;
4682	>	if ((t = map.table) != null) {
4683	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4684	>	for (Node<K,V> p; (p = it.advance()) != null; )
4685	>	action.accept(p.key);
4686	>	}
4687		}
4688		}
4689
4690	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4691	<	public Iterator<Map.Entry<K,V>> iterator() {
4692	<	return new EntryIterator();
4690	>	/**
4691	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4692	>	* values, in which additions are disabled. This class cannot be
4693	>	* directly instantiated. See {@link #values()}.
4694	>	*/
4695	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4696	>	implements Collection<V>, java.io.Serializable {
4697	>	private static final long serialVersionUID = 2249069246763182397L;
4698	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4699	>	public final boolean contains(Object o) {
4700	>	return map.containsValue(o);
4701	>	}
4702	>
4703	>	public final boolean remove(Object o) {
4704	>	if (o != null) {
4705	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4706	>	if (o.equals(it.next())) {
4707	>	it.remove();
4708	>	return true;
4709	>	}
4710	>	}
4711	>	}
4712	>	return false;
4713	>	}
4714	>
4715	>	public final Iterator<V> iterator() {
4716	>	ConcurrentHashMap<K,V> m = map;
4717	>	Node<K,V>[] t;
4718	>	int f = (t = m.table) == null ? 0 : t.length;
4719	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4720	>	}
4721	>
4722	>	public final boolean add(V e) {
4723	>	throw new UnsupportedOperationException();
4724	>	}
4725	>	public final boolean addAll(Collection<? extends V> c) {
4726	>	throw new UnsupportedOperationException();
4727	>	}
4728	>
4729	>	@Override public boolean removeAll(Collection<?> c) {
4730	>	if (c == null) throw new NullPointerException();
4731	>	boolean modified = false;
4732	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4733	>	if (c.contains(it.next())) {
4734	>	it.remove();
4735	>	modified = true;
4736	>	}
4737	>	}
4738	>	return modified;
4739	>	}
4740	>
4741	>	public boolean removeIf(Predicate<? super V> filter) {
4742	>	return map.removeValueIf(filter);
4743		}
4744	+
4745	+	public Spliterator<V> spliterator() {
4746	+	Node<K,V>[] t;
4747	+	ConcurrentHashMap<K,V> m = map;
4748	+	long n = m.sumCount();
4749	+	int f = (t = m.table) == null ? 0 : t.length;
4750	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4751	+	}
4752	+
4753	+	public void forEach(Consumer<? super V> action) {
4754	+	if (action == null) throw new NullPointerException();
4755	+	Node<K,V>[] t;
4756	+	if ((t = map.table) != null) {
4757	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4758	+	for (Node<K,V> p; (p = it.advance()) != null; )
4759	+	action.accept(p.val);
4760	+	}
4761	+	}
4762	+	}
4763	+
4764	+	/**
4765	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4766	+	* entries.  This class cannot be directly instantiated. See
4767	+	* {@link #entrySet()}.
4768	+	*/
4769	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4770	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4771	+	private static final long serialVersionUID = 2249069246763182397L;
4772	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4773	+
4774		public boolean contains(Object o) {
4775	<	if (!(o instanceof Map.Entry))
4776	<	return false;
4777	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4778	<	V v = ConcurrentHashMap.this.get(e.getKey());
4779	<	return v != null && v.equals(e.getValue());
4775	>	Object k, v, r; Map.Entry<?,?> e;
4776	>	return ((o instanceof Map.Entry) &&
4777	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4778	>	(r = map.get(k)) != null &&
4779	>	(v = e.getValue()) != null &&
4780	>	(v == r || v.equals(r)));
4781		}
4782	+
4783		public boolean remove(Object o) {
4784	<	if (!(o instanceof Map.Entry))
4785	<	return false;
4786	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4787	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4784	>	Object k, v; Map.Entry<?,?> e;
4785	>	return ((o instanceof Map.Entry) &&
4786	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4787	>	(v = e.getValue()) != null &&
4788	>	map.remove(k, v));
4789	>	}
4790	>
4791	>	/**
4792	>	* @return an iterator over the entries of the backing map
4793	>	*/
4794	>	public Iterator<Map.Entry<K,V>> iterator() {
4795	>	ConcurrentHashMap<K,V> m = map;
4796	>	Node<K,V>[] t;
4797	>	int f = (t = m.table) == null ? 0 : t.length;
4798	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4799	>	}
4800	>
4801	>	public boolean add(Entry<K,V> e) {
4802	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4803	>	}
4804	>
4805	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4806	>	boolean added = false;
4807	>	for (Entry<K,V> e : c) {
4808	>	if (add(e))
4809	>	added = true;
4810	>	}
4811	>	return added;
4812	>	}
4813	>
4814	>	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4815	>	return map.removeEntryIf(filter);
4816		}
4817	<	public int size() {
4818	<	return ConcurrentHashMap.this.size();
4817	>
4818	>	public final int hashCode() {
4819	>	int h = 0;
4820	>	Node<K,V>[] t;
4821	>	if ((t = map.table) != null) {
4822	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4823	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4824	>	h += p.hashCode();
4825	>	}
4826	>	}
4827	>	return h;
4828		}
4829	<	public void clear() {
4830	<	ConcurrentHashMap.this.clear();
4829	>
4830	>	public final boolean equals(Object o) {
4831	>	Set<?> c;
4832	>	return ((o instanceof Set) &&
4833	>	((c = (Set<?>)o) == this ||
4834	>	(containsAll(c) && c.containsAll(this))));
4835	>	}
4836	>
4837	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4838	>	Node<K,V>[] t;
4839	>	ConcurrentHashMap<K,V> m = map;
4840	>	long n = m.sumCount();
4841	>	int f = (t = m.table) == null ? 0 : t.length;
4842	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4843	>	}
4844	>
4845	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4846	>	if (action == null) throw new NullPointerException();
4847	>	Node<K,V>[] t;
4848	>	if ((t = map.table) != null) {
4849	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4850	>	for (Node<K,V> p; (p = it.advance()) != null; )
4851	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4852	>	}
4853		}
4854	+
4855		}
4856
4857	<	/* ---------------- Serialization Support -------------- */
4857	>	// -------------------------------------------------------
4858
4859		/**
4860	<	* Save the state of the <tt>ConcurrentHashMap</tt> instance to a
4861	<	* stream (i.e., serialize it).
1226	<	* @param s the stream
1227	<	* @serialData
1228	<	* the key (Object) and value (Object)
1229	<	* for each key-value mapping, followed by a null pair.
1230	<	* The key-value mappings are emitted in no particular order.
4860	>	* Base class for bulk tasks. Repeats some fields and code from
4861	>	* class Traverser, because we need to subclass CountedCompleter.
4862		*/
4863	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
4864	<	s.defaultWriteObject();
4863	>	@SuppressWarnings("serial")
4864	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4865	>	Node<K,V>[] tab;        // same as Traverser
4866	>	Node<K,V> next;
4867	>	TableStack<K,V> stack, spare;
4868	>	int index;
4869	>	int baseIndex;
4870	>	int baseLimit;
4871	>	final int baseSize;
4872	>	int batch;              // split control
4873	>
4874	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4875	>	super(par);
4876	>	this.batch = b;
4877	>	this.index = this.baseIndex = i;
4878	>	if ((this.tab = t) == null)
4879	>	this.baseSize = this.baseLimit = 0;
4880	>	else if (par == null)
4881	>	this.baseSize = this.baseLimit = t.length;
4882	>	else {
4883	>	this.baseLimit = f;
4884	>	this.baseSize = par.baseSize;
4885	>	}
4886	>	}
4887
4888	<	for (int k = 0; k < segments.length; ++k) {
4889	<	Segment<K,V> seg = segments[k];
4890	<	seg.lock();
4891	<	try {
4892	<	HashEntry<K,V>[] tab = seg.table;
4893	<	for (int i = 0; i < tab.length; ++i) {
4894	<	for (HashEntry<K,V> e = tab[i]; e != null; e = e.next) {
4895	<	s.writeObject(e.key);
4896	<	s.writeObject(e.value);
4888	>	/**
4889	>	* Same as Traverser version.
4890	>	*/
4891	>	final Node<K,V> advance() {
4892	>	Node<K,V> e;
4893	>	if ((e = next) != null)
4894	>	e = e.next;
4895	>	for (;;) {
4896	>	Node<K,V>[] t; int i, n;
4897	>	if (e != null)
4898	>	return next = e;
4899	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4900	>	(n = t.length) <= (i = index) || i < 0)
4901	>	return next = null;
4902	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4903	>	if (e instanceof ForwardingNode) {
4904	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4905	>	e = null;
4906	>	pushState(t, i, n);
4907	>	continue;
4908		}
4909	+	else if (e instanceof TreeBin)
4910	+	e = ((TreeBin<K,V>)e).first;
4911	+	else
4912	+	e = null;
4913		}
4914	<	} finally {
4915	<	seg.unlock();
4914	>	if (stack != null)
4915	>	recoverState(n);
4916	>	else if ((index = i + baseSize) >= n)
4917	>	index = ++baseIndex;
4918		}
4919		}
4920	<	s.writeObject(null);
4921	<	s.writeObject(null);
4920	>
4921	>	private void pushState(Node<K,V>[] t, int i, int n) {
4922	>	TableStack<K,V> s = spare;
4923	>	if (s != null)
4924	>	spare = s.next;
4925	>	else
4926	>	s = new TableStack<K,V>();
4927	>	s.tab = t;
4928	>	s.length = n;
4929	>	s.index = i;
4930	>	s.next = stack;
4931	>	stack = s;
4932	>	}
4933	>
4934	>	private void recoverState(int n) {
4935	>	TableStack<K,V> s; int len;
4936	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4937	>	n = len;
4938	>	index = s.index;
4939	>	tab = s.tab;
4940	>	s.tab = null;
4941	>	TableStack<K,V> next = s.next;
4942	>	s.next = spare; // save for reuse
4943	>	stack = next;
4944	>	spare = s;
4945	>	}
4946	>	if (s == null && (index += baseSize) >= n)
4947	>	index = ++baseIndex;
4948	>	}
4949		}
4950
4951	<	/**
4952	<	* Reconstitute the <tt>ConcurrentHashMap</tt> instance from a
4953	<	* stream (i.e., deserialize it).
4954	<	* @param s the stream
4955	<	*/
4956	<	private void readObject(java.io.ObjectInputStream s)
4957	<	throws IOException, ClassNotFoundException  {
4958	<	s.defaultReadObject();
4951	>	/*
4952	>	* Task classes. Coded in a regular but ugly format/style to
4953	>	* simplify checks that each variant differs in the right way from
4954	>	* others. The null screenings exist because compilers cannot tell
4955	>	* that we've already null-checked task arguments, so we force
4956	>	* simplest hoisted bypass to help avoid convoluted traps.
4957	>	*/
4958	>	@SuppressWarnings("serial")
4959	>	static final class ForEachKeyTask<K,V>
4960	>	extends BulkTask<K,V,Void> {
4961	>	final Consumer<? super K> action;
4962	>	ForEachKeyTask
4963	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4964	>	Consumer<? super K> action) {
4965	>	super(p, b, i, f, t);
4966	>	this.action = action;
4967	>	}
4968	>	public final void compute() {
4969	>	final Consumer<? super K> action;
4970	>	if ((action = this.action) != null) {
4971	>	for (int i = baseIndex, f, h; batch > 0 &&
4972	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4973	>	addToPendingCount(1);
4974	>	new ForEachKeyTask<K,V>
4975	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4976	>	action).fork();
4977	>	}
4978	>	for (Node<K,V> p; (p = advance()) != null;)
4979	>	action.accept(p.key);
4980	>	propagateCompletion();
4981	>	}
4982	>	}
4983	>	}
4984
4985	<	// Initialize each segment to be minimally sized, and let grow.
4986	<	for (int i = 0; i < segments.length; ++i) {
4987	<	segments[i].setTable(new HashEntry[1]);
4985	>	@SuppressWarnings("serial")
4986	>	static final class ForEachValueTask<K,V>
4987	>	extends BulkTask<K,V,Void> {
4988	>	final Consumer<? super V> action;
4989	>	ForEachValueTask
4990	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4991	>	Consumer<? super V> action) {
4992	>	super(p, b, i, f, t);
4993	>	this.action = action;
4994	>	}
4995	>	public final void compute() {
4996	>	final Consumer<? super V> action;
4997	>	if ((action = this.action) != null) {
4998	>	for (int i = baseIndex, f, h; batch > 0 &&
4999	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5000	>	addToPendingCount(1);
5001	>	new ForEachValueTask<K,V>
5002	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5003	>	action).fork();
5004	>	}
5005	>	for (Node<K,V> p; (p = advance()) != null;)
5006	>	action.accept(p.val);
5007	>	propagateCompletion();
5008	>	}
5009		}
5010	+	}
5011
5012	<	// Read the keys and values, and put the mappings in the table
5013	<	for (;;) {
5014	<	K key = (K) s.readObject();
5015	<	V value = (V) s.readObject();
5016	<	if (key == null)
5017	<	break;
5018	<	put(key, value);
5012	>	@SuppressWarnings("serial")
5013	>	static final class ForEachEntryTask<K,V>
5014	>	extends BulkTask<K,V,Void> {
5015	>	final Consumer<? super Entry<K,V>> action;
5016	>	ForEachEntryTask
5017	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5018	>	Consumer<? super Entry<K,V>> action) {
5019	>	super(p, b, i, f, t);
5020	>	this.action = action;
5021	>	}
5022	>	public final void compute() {
5023	>	final Consumer<? super Entry<K,V>> action;
5024	>	if ((action = this.action) != null) {
5025	>	for (int i = baseIndex, f, h; batch > 0 &&
5026	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5027	>	addToPendingCount(1);
5028	>	new ForEachEntryTask<K,V>
5029	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5030	>	action).fork();
5031	>	}
5032	>	for (Node<K,V> p; (p = advance()) != null; )
5033	>	action.accept(p);
5034	>	propagateCompletion();
5035	>	}
5036	>	}
5037	>	}
5038	>
5039	>	@SuppressWarnings("serial")
5040	>	static final class ForEachMappingTask<K,V>
5041	>	extends BulkTask<K,V,Void> {
5042	>	final BiConsumer<? super K, ? super V> action;
5043	>	ForEachMappingTask
5044	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5045	>	BiConsumer<? super K,? super V> action) {
5046	>	super(p, b, i, f, t);
5047	>	this.action = action;
5048	>	}
5049	>	public final void compute() {
5050	>	final BiConsumer<? super K, ? super V> action;
5051	>	if ((action = this.action) != null) {
5052	>	for (int i = baseIndex, f, h; batch > 0 &&
5053	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5054	>	addToPendingCount(1);
5055	>	new ForEachMappingTask<K,V>
5056	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5057	>	action).fork();
5058	>	}
5059	>	for (Node<K,V> p; (p = advance()) != null; )
5060	>	action.accept(p.key, p.val);
5061	>	propagateCompletion();
5062	>	}
5063		}
5064		}
5065	+
5066	+	@SuppressWarnings("serial")
5067	+	static final class ForEachTransformedKeyTask<K,V,U>
5068	+	extends BulkTask<K,V,Void> {
5069	+	final Function<? super K, ? extends U> transformer;
5070	+	final Consumer<? super U> action;
5071	+	ForEachTransformedKeyTask
5072	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5073	+	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5074	+	super(p, b, i, f, t);
5075	+	this.transformer = transformer; this.action = action;
5076	+	}
5077	+	public final void compute() {
5078	+	final Function<? super K, ? extends U> transformer;
5079	+	final Consumer<? super U> action;
5080	+	if ((transformer = this.transformer) != null &&
5081	+	(action = this.action) != null) {
5082	+	for (int i = baseIndex, f, h; batch > 0 &&
5083	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5084	+	addToPendingCount(1);
5085	+	new ForEachTransformedKeyTask<K,V,U>
5086	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5087	+	transformer, action).fork();
5088	+	}
5089	+	for (Node<K,V> p; (p = advance()) != null; ) {
5090	+	U u;
5091	+	if ((u = transformer.apply(p.key)) != null)
5092	+	action.accept(u);
5093	+	}
5094	+	propagateCompletion();
5095	+	}
5096	+	}
5097	+	}
5098	+
5099	+	@SuppressWarnings("serial")
5100	+	static final class ForEachTransformedValueTask<K,V,U>
5101	+	extends BulkTask<K,V,Void> {
5102	+	final Function<? super V, ? extends U> transformer;
5103	+	final Consumer<? super U> action;
5104	+	ForEachTransformedValueTask
5105	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5106	+	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5107	+	super(p, b, i, f, t);
5108	+	this.transformer = transformer; this.action = action;
5109	+	}
5110	+	public final void compute() {
5111	+	final Function<? super V, ? extends U> transformer;
5112	+	final Consumer<? super U> action;
5113	+	if ((transformer = this.transformer) != null &&
5114	+	(action = this.action) != null) {
5115	+	for (int i = baseIndex, f, h; batch > 0 &&
5116	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5117	+	addToPendingCount(1);
5118	+	new ForEachTransformedValueTask<K,V,U>
5119	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5120	+	transformer, action).fork();
5121	+	}
5122	+	for (Node<K,V> p; (p = advance()) != null; ) {
5123	+	U u;
5124	+	if ((u = transformer.apply(p.val)) != null)
5125	+	action.accept(u);
5126	+	}
5127	+	propagateCompletion();
5128	+	}
5129	+	}
5130	+	}
5131	+
5132	+	@SuppressWarnings("serial")
5133	+	static final class ForEachTransformedEntryTask<K,V,U>
5134	+	extends BulkTask<K,V,Void> {
5135	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5136	+	final Consumer<? super U> action;
5137	+	ForEachTransformedEntryTask
5138	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5139	+	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5140	+	super(p, b, i, f, t);
5141	+	this.transformer = transformer; this.action = action;
5142	+	}
5143	+	public final void compute() {
5144	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5145	+	final Consumer<? super U> action;
5146	+	if ((transformer = this.transformer) != null &&
5147	+	(action = this.action) != null) {
5148	+	for (int i = baseIndex, f, h; batch > 0 &&
5149	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5150	+	addToPendingCount(1);
5151	+	new ForEachTransformedEntryTask<K,V,U>
5152	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5153	+	transformer, action).fork();
5154	+	}
5155	+	for (Node<K,V> p; (p = advance()) != null; ) {
5156	+	U u;
5157	+	if ((u = transformer.apply(p)) != null)
5158	+	action.accept(u);
5159	+	}
5160	+	propagateCompletion();
5161	+	}
5162	+	}
5163	+	}
5164	+
5165	+	@SuppressWarnings("serial")
5166	+	static final class ForEachTransformedMappingTask<K,V,U>
5167	+	extends BulkTask<K,V,Void> {
5168	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5169	+	final Consumer<? super U> action;
5170	+	ForEachTransformedMappingTask
5171	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5172	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5173	+	Consumer<? super U> action) {
5174	+	super(p, b, i, f, t);
5175	+	this.transformer = transformer; this.action = action;
5176	+	}
5177	+	public final void compute() {
5178	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5179	+	final Consumer<? super U> action;
5180	+	if ((transformer = this.transformer) != null &&
5181	+	(action = this.action) != null) {
5182	+	for (int i = baseIndex, f, h; batch > 0 &&
5183	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5184	+	addToPendingCount(1);
5185	+	new ForEachTransformedMappingTask<K,V,U>
5186	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5187	+	transformer, action).fork();
5188	+	}
5189	+	for (Node<K,V> p; (p = advance()) != null; ) {
5190	+	U u;
5191	+	if ((u = transformer.apply(p.key, p.val)) != null)
5192	+	action.accept(u);
5193	+	}
5194	+	propagateCompletion();
5195	+	}
5196	+	}
5197	+	}
5198	+
5199	+	@SuppressWarnings("serial")
5200	+	static final class SearchKeysTask<K,V,U>
5201	+	extends BulkTask<K,V,U> {
5202	+	final Function<? super K, ? extends U> searchFunction;
5203	+	final AtomicReference<U> result;
5204	+	SearchKeysTask
5205	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5206	+	Function<? super K, ? extends U> searchFunction,
5207	+	AtomicReference<U> result) {
5208	+	super(p, b, i, f, t);
5209	+	this.searchFunction = searchFunction; this.result = result;
5210	+	}
5211	+	public final U getRawResult() { return result.get(); }
5212	+	public final void compute() {
5213	+	final Function<? super K, ? extends U> searchFunction;
5214	+	final AtomicReference<U> result;
5215	+	if ((searchFunction = this.searchFunction) != null &&
5216	+	(result = this.result) != null) {
5217	+	for (int i = baseIndex, f, h; batch > 0 &&
5218	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5219	+	if (result.get() != null)
5220	+	return;
5221	+	addToPendingCount(1);
5222	+	new SearchKeysTask<K,V,U>
5223	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5224	+	searchFunction, result).fork();
5225	+	}
5226	+	while (result.get() == null) {
5227	+	U u;
5228	+	Node<K,V> p;
5229	+	if ((p = advance()) == null) {
5230	+	propagateCompletion();
5231	+	break;
5232	+	}
5233	+	if ((u = searchFunction.apply(p.key)) != null) {
5234	+	if (result.compareAndSet(null, u))
5235	+	quietlyCompleteRoot();
5236	+	break;
5237	+	}
5238	+	}
5239	+	}
5240	+	}
5241	+	}
5242	+
5243	+	@SuppressWarnings("serial")
5244	+	static final class SearchValuesTask<K,V,U>
5245	+	extends BulkTask<K,V,U> {
5246	+	final Function<? super V, ? extends U> searchFunction;
5247	+	final AtomicReference<U> result;
5248	+	SearchValuesTask
5249	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5250	+	Function<? super V, ? extends U> searchFunction,
5251	+	AtomicReference<U> result) {
5252	+	super(p, b, i, f, t);
5253	+	this.searchFunction = searchFunction; this.result = result;
5254	+	}
5255	+	public final U getRawResult() { return result.get(); }
5256	+	public final void compute() {
5257	+	final Function<? super V, ? extends U> searchFunction;
5258	+	final AtomicReference<U> result;
5259	+	if ((searchFunction = this.searchFunction) != null &&
5260	+	(result = this.result) != null) {
5261	+	for (int i = baseIndex, f, h; batch > 0 &&
5262	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5263	+	if (result.get() != null)
5264	+	return;
5265	+	addToPendingCount(1);
5266	+	new SearchValuesTask<K,V,U>
5267	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5268	+	searchFunction, result).fork();
5269	+	}
5270	+	while (result.get() == null) {
5271	+	U u;
5272	+	Node<K,V> p;
5273	+	if ((p = advance()) == null) {
5274	+	propagateCompletion();
5275	+	break;
5276	+	}
5277	+	if ((u = searchFunction.apply(p.val)) != null) {
5278	+	if (result.compareAndSet(null, u))
5279	+	quietlyCompleteRoot();
5280	+	break;
5281	+	}
5282	+	}
5283	+	}
5284	+	}
5285	+	}
5286	+
5287	+	@SuppressWarnings("serial")
5288	+	static final class SearchEntriesTask<K,V,U>
5289	+	extends BulkTask<K,V,U> {
5290	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5291	+	final AtomicReference<U> result;
5292	+	SearchEntriesTask
5293	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5294	+	Function<Entry<K,V>, ? extends U> searchFunction,
5295	+	AtomicReference<U> result) {
5296	+	super(p, b, i, f, t);
5297	+	this.searchFunction = searchFunction; this.result = result;
5298	+	}
5299	+	public final U getRawResult() { return result.get(); }
5300	+	public final void compute() {
5301	+	final Function<Entry<K,V>, ? extends U> searchFunction;
5302	+	final AtomicReference<U> result;
5303	+	if ((searchFunction = this.searchFunction) != null &&
5304	+	(result = this.result) != null) {
5305	+	for (int i = baseIndex, f, h; batch > 0 &&
5306	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5307	+	if (result.get() != null)
5308	+	return;
5309	+	addToPendingCount(1);
5310	+	new SearchEntriesTask<K,V,U>
5311	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5312	+	searchFunction, result).fork();
5313	+	}
5314	+	while (result.get() == null) {
5315	+	U u;
5316	+	Node<K,V> p;
5317	+	if ((p = advance()) == null) {
5318	+	propagateCompletion();
5319	+	break;
5320	+	}
5321	+	if ((u = searchFunction.apply(p)) != null) {
5322	+	if (result.compareAndSet(null, u))
5323	+	quietlyCompleteRoot();
5324	+	return;
5325	+	}
5326	+	}
5327	+	}
5328	+	}
5329	+	}
5330	+
5331	+	@SuppressWarnings("serial")
5332	+	static final class SearchMappingsTask<K,V,U>
5333	+	extends BulkTask<K,V,U> {
5334	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5335	+	final AtomicReference<U> result;
5336	+	SearchMappingsTask
5337	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5338	+	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5339	+	AtomicReference<U> result) {
5340	+	super(p, b, i, f, t);
5341	+	this.searchFunction = searchFunction; this.result = result;
5342	+	}
5343	+	public final U getRawResult() { return result.get(); }
5344	+	public final void compute() {
5345	+	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5346	+	final AtomicReference<U> result;
5347	+	if ((searchFunction = this.searchFunction) != null &&
5348	+	(result = this.result) != null) {
5349	+	for (int i = baseIndex, f, h; batch > 0 &&
5350	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5351	+	if (result.get() != null)
5352	+	return;
5353	+	addToPendingCount(1);
5354	+	new SearchMappingsTask<K,V,U>
5355	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5356	+	searchFunction, result).fork();
5357	+	}
5358	+	while (result.get() == null) {
5359	+	U u;
5360	+	Node<K,V> p;
5361	+	if ((p = advance()) == null) {
5362	+	propagateCompletion();
5363	+	break;
5364	+	}
5365	+	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5366	+	if (result.compareAndSet(null, u))
5367	+	quietlyCompleteRoot();
5368	+	break;
5369	+	}
5370	+	}
5371	+	}
5372	+	}
5373	+	}
5374	+
5375	+	@SuppressWarnings("serial")
5376	+	static final class ReduceKeysTask<K,V>
5377	+	extends BulkTask<K,V,K> {
5378	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5379	+	K result;
5380	+	ReduceKeysTask<K,V> rights, nextRight;
5381	+	ReduceKeysTask
5382	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5383	+	ReduceKeysTask<K,V> nextRight,
5384	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
5385	+	super(p, b, i, f, t); this.nextRight = nextRight;
5386	+	this.reducer = reducer;
5387	+	}
5388	+	public final K getRawResult() { return result; }
5389	+	public final void compute() {
5390	+	final BiFunction<? super K, ? super K, ? extends K> reducer;
5391	+	if ((reducer = this.reducer) != null) {
5392	+	for (int i = baseIndex, f, h; batch > 0 &&
5393	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5394	+	addToPendingCount(1);
5395	+	(rights = new ReduceKeysTask<K,V>
5396	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5397	+	rights, reducer)).fork();
5398	+	}
5399	+	K r = null;
5400	+	for (Node<K,V> p; (p = advance()) != null; ) {
5401	+	K u = p.key;
5402	+	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5403	+	}
5404	+	result = r;
5405	+	CountedCompleter<?> c;
5406	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5407	+	@SuppressWarnings("unchecked")
5408	+	ReduceKeysTask<K,V>
5409	+	t = (ReduceKeysTask<K,V>)c,
5410	+	s = t.rights;
5411	+	while (s != null) {
5412	+	K tr, sr;
5413	+	if ((sr = s.result) != null)
5414	+	t.result = (((tr = t.result) == null) ? sr :
5415	+	reducer.apply(tr, sr));
5416	+	s = t.rights = s.nextRight;
5417	+	}
5418	+	}
5419	+	}
5420	+	}
5421	+	}
5422	+
5423	+	@SuppressWarnings("serial")
5424	+	static final class ReduceValuesTask<K,V>
5425	+	extends BulkTask<K,V,V> {
5426	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5427	+	V result;
5428	+	ReduceValuesTask<K,V> rights, nextRight;
5429	+	ReduceValuesTask
5430	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5431	+	ReduceValuesTask<K,V> nextRight,
5432	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
5433	+	super(p, b, i, f, t); this.nextRight = nextRight;
5434	+	this.reducer = reducer;
5435	+	}
5436	+	public final V getRawResult() { return result; }
5437	+	public final void compute() {
5438	+	final BiFunction<? super V, ? super V, ? extends V> reducer;
5439	+	if ((reducer = this.reducer) != null) {
5440	+	for (int i = baseIndex, f, h; batch > 0 &&
5441	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5442	+	addToPendingCount(1);
5443	+	(rights = new ReduceValuesTask<K,V>
5444	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5445	+	rights, reducer)).fork();
5446	+	}
5447	+	V r = null;
5448	+	for (Node<K,V> p; (p = advance()) != null; ) {
5449	+	V v = p.val;
5450	+	r = (r == null) ? v : reducer.apply(r, v);
5451	+	}
5452	+	result = r;
5453	+	CountedCompleter<?> c;
5454	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5455	+	@SuppressWarnings("unchecked")
5456	+	ReduceValuesTask<K,V>
5457	+	t = (ReduceValuesTask<K,V>)c,
5458	+	s = t.rights;
5459	+	while (s != null) {
5460	+	V tr, sr;
5461	+	if ((sr = s.result) != null)
5462	+	t.result = (((tr = t.result) == null) ? sr :
5463	+	reducer.apply(tr, sr));
5464	+	s = t.rights = s.nextRight;
5465	+	}
5466	+	}
5467	+	}
5468	+	}
5469	+	}
5470	+
5471	+	@SuppressWarnings("serial")
5472	+	static final class ReduceEntriesTask<K,V>
5473	+	extends BulkTask<K,V,Map.Entry<K,V>> {
5474	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5475	+	Map.Entry<K,V> result;
5476	+	ReduceEntriesTask<K,V> rights, nextRight;
5477	+	ReduceEntriesTask
5478	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5479	+	ReduceEntriesTask<K,V> nextRight,
5480	+	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5481	+	super(p, b, i, f, t); this.nextRight = nextRight;
5482	+	this.reducer = reducer;
5483	+	}
5484	+	public final Map.Entry<K,V> getRawResult() { return result; }
5485	+	public final void compute() {
5486	+	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5487	+	if ((reducer = this.reducer) != null) {
5488	+	for (int i = baseIndex, f, h; batch > 0 &&
5489	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5490	+	addToPendingCount(1);
5491	+	(rights = new ReduceEntriesTask<K,V>
5492	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5493	+	rights, reducer)).fork();
5494	+	}
5495	+	Map.Entry<K,V> r = null;
5496	+	for (Node<K,V> p; (p = advance()) != null; )
5497	+	r = (r == null) ? p : reducer.apply(r, p);
5498	+	result = r;
5499	+	CountedCompleter<?> c;
5500	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5501	+	@SuppressWarnings("unchecked")
5502	+	ReduceEntriesTask<K,V>
5503	+	t = (ReduceEntriesTask<K,V>)c,
5504	+	s = t.rights;
5505	+	while (s != null) {
5506	+	Map.Entry<K,V> tr, sr;
5507	+	if ((sr = s.result) != null)
5508	+	t.result = (((tr = t.result) == null) ? sr :
5509	+	reducer.apply(tr, sr));
5510	+	s = t.rights = s.nextRight;
5511	+	}
5512	+	}
5513	+	}
5514	+	}
5515	+	}
5516	+
5517	+	@SuppressWarnings("serial")
5518	+	static final class MapReduceKeysTask<K,V,U>
5519	+	extends BulkTask<K,V,U> {
5520	+	final Function<? super K, ? extends U> transformer;
5521	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5522	+	U result;
5523	+	MapReduceKeysTask<K,V,U> rights, nextRight;
5524	+	MapReduceKeysTask
5525	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5526	+	MapReduceKeysTask<K,V,U> nextRight,
5527	+	Function<? super K, ? extends U> transformer,
5528	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5529	+	super(p, b, i, f, t); this.nextRight = nextRight;
5530	+	this.transformer = transformer;
5531	+	this.reducer = reducer;
5532	+	}
5533	+	public final U getRawResult() { return result; }
5534	+	public final void compute() {
5535	+	final Function<? super K, ? extends U> transformer;
5536	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5537	+	if ((transformer = this.transformer) != null &&
5538	+	(reducer = this.reducer) != null) {
5539	+	for (int i = baseIndex, f, h; batch > 0 &&
5540	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5541	+	addToPendingCount(1);
5542	+	(rights = new MapReduceKeysTask<K,V,U>
5543	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5544	+	rights, transformer, reducer)).fork();
5545	+	}
5546	+	U r = null;
5547	+	for (Node<K,V> p; (p = advance()) != null; ) {
5548	+	U u;
5549	+	if ((u = transformer.apply(p.key)) != null)
5550	+	r = (r == null) ? u : reducer.apply(r, u);
5551	+	}
5552	+	result = r;
5553	+	CountedCompleter<?> c;
5554	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5555	+	@SuppressWarnings("unchecked")
5556	+	MapReduceKeysTask<K,V,U>
5557	+	t = (MapReduceKeysTask<K,V,U>)c,
5558	+	s = t.rights;
5559	+	while (s != null) {
5560	+	U tr, sr;
5561	+	if ((sr = s.result) != null)
5562	+	t.result = (((tr = t.result) == null) ? sr :
5563	+	reducer.apply(tr, sr));
5564	+	s = t.rights = s.nextRight;
5565	+	}
5566	+	}
5567	+	}
5568	+	}
5569	+	}
5570	+
5571	+	@SuppressWarnings("serial")
5572	+	static final class MapReduceValuesTask<K,V,U>
5573	+	extends BulkTask<K,V,U> {
5574	+	final Function<? super V, ? extends U> transformer;
5575	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5576	+	U result;
5577	+	MapReduceValuesTask<K,V,U> rights, nextRight;
5578	+	MapReduceValuesTask
5579	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5580	+	MapReduceValuesTask<K,V,U> nextRight,
5581	+	Function<? super V, ? extends U> transformer,
5582	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5583	+	super(p, b, i, f, t); this.nextRight = nextRight;
5584	+	this.transformer = transformer;
5585	+	this.reducer = reducer;
5586	+	}
5587	+	public final U getRawResult() { return result; }
5588	+	public final void compute() {
5589	+	final Function<? super V, ? extends U> transformer;
5590	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5591	+	if ((transformer = this.transformer) != null &&
5592	+	(reducer = this.reducer) != null) {
5593	+	for (int i = baseIndex, f, h; batch > 0 &&
5594	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5595	+	addToPendingCount(1);
5596	+	(rights = new MapReduceValuesTask<K,V,U>
5597	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5598	+	rights, transformer, reducer)).fork();
5599	+	}
5600	+	U r = null;
5601	+	for (Node<K,V> p; (p = advance()) != null; ) {
5602	+	U u;
5603	+	if ((u = transformer.apply(p.val)) != null)
5604	+	r = (r == null) ? u : reducer.apply(r, u);
5605	+	}
5606	+	result = r;
5607	+	CountedCompleter<?> c;
5608	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5609	+	@SuppressWarnings("unchecked")
5610	+	MapReduceValuesTask<K,V,U>
5611	+	t = (MapReduceValuesTask<K,V,U>)c,
5612	+	s = t.rights;
5613	+	while (s != null) {
5614	+	U tr, sr;
5615	+	if ((sr = s.result) != null)
5616	+	t.result = (((tr = t.result) == null) ? sr :
5617	+	reducer.apply(tr, sr));
5618	+	s = t.rights = s.nextRight;
5619	+	}
5620	+	}
5621	+	}
5622	+	}
5623	+	}
5624	+
5625	+	@SuppressWarnings("serial")
5626	+	static final class MapReduceEntriesTask<K,V,U>
5627	+	extends BulkTask<K,V,U> {
5628	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5629	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5630	+	U result;
5631	+	MapReduceEntriesTask<K,V,U> rights, nextRight;
5632	+	MapReduceEntriesTask
5633	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5634	+	MapReduceEntriesTask<K,V,U> nextRight,
5635	+	Function<Map.Entry<K,V>, ? extends U> transformer,
5636	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5637	+	super(p, b, i, f, t); this.nextRight = nextRight;
5638	+	this.transformer = transformer;
5639	+	this.reducer = reducer;
5640	+	}
5641	+	public final U getRawResult() { return result; }
5642	+	public final void compute() {
5643	+	final Function<Map.Entry<K,V>, ? extends U> transformer;
5644	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5645	+	if ((transformer = this.transformer) != null &&
5646	+	(reducer = this.reducer) != null) {
5647	+	for (int i = baseIndex, f, h; batch > 0 &&
5648	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5649	+	addToPendingCount(1);
5650	+	(rights = new MapReduceEntriesTask<K,V,U>
5651	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5652	+	rights, transformer, reducer)).fork();
5653	+	}
5654	+	U r = null;
5655	+	for (Node<K,V> p; (p = advance()) != null; ) {
5656	+	U u;
5657	+	if ((u = transformer.apply(p)) != null)
5658	+	r = (r == null) ? u : reducer.apply(r, u);
5659	+	}
5660	+	result = r;
5661	+	CountedCompleter<?> c;
5662	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5663	+	@SuppressWarnings("unchecked")
5664	+	MapReduceEntriesTask<K,V,U>
5665	+	t = (MapReduceEntriesTask<K,V,U>)c,
5666	+	s = t.rights;
5667	+	while (s != null) {
5668	+	U tr, sr;
5669	+	if ((sr = s.result) != null)
5670	+	t.result = (((tr = t.result) == null) ? sr :
5671	+	reducer.apply(tr, sr));
5672	+	s = t.rights = s.nextRight;
5673	+	}
5674	+	}
5675	+	}
5676	+	}
5677	+	}
5678	+
5679	+	@SuppressWarnings("serial")
5680	+	static final class MapReduceMappingsTask<K,V,U>
5681	+	extends BulkTask<K,V,U> {
5682	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5683	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5684	+	U result;
5685	+	MapReduceMappingsTask<K,V,U> rights, nextRight;
5686	+	MapReduceMappingsTask
5687	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5688	+	MapReduceMappingsTask<K,V,U> nextRight,
5689	+	BiFunction<? super K, ? super V, ? extends U> transformer,
5690	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
5691	+	super(p, b, i, f, t); this.nextRight = nextRight;
5692	+	this.transformer = transformer;
5693	+	this.reducer = reducer;
5694	+	}
5695	+	public final U getRawResult() { return result; }
5696	+	public final void compute() {
5697	+	final BiFunction<? super K, ? super V, ? extends U> transformer;
5698	+	final BiFunction<? super U, ? super U, ? extends U> reducer;
5699	+	if ((transformer = this.transformer) != null &&
5700	+	(reducer = this.reducer) != null) {
5701	+	for (int i = baseIndex, f, h; batch > 0 &&
5702	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5703	+	addToPendingCount(1);
5704	+	(rights = new MapReduceMappingsTask<K,V,U>
5705	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5706	+	rights, transformer, reducer)).fork();
5707	+	}
5708	+	U r = null;
5709	+	for (Node<K,V> p; (p = advance()) != null; ) {
5710	+	U u;
5711	+	if ((u = transformer.apply(p.key, p.val)) != null)
5712	+	r = (r == null) ? u : reducer.apply(r, u);
5713	+	}
5714	+	result = r;
5715	+	CountedCompleter<?> c;
5716	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5717	+	@SuppressWarnings("unchecked")
5718	+	MapReduceMappingsTask<K,V,U>
5719	+	t = (MapReduceMappingsTask<K,V,U>)c,
5720	+	s = t.rights;
5721	+	while (s != null) {
5722	+	U tr, sr;
5723	+	if ((sr = s.result) != null)
5724	+	t.result = (((tr = t.result) == null) ? sr :
5725	+	reducer.apply(tr, sr));
5726	+	s = t.rights = s.nextRight;
5727	+	}
5728	+	}
5729	+	}
5730	+	}
5731	+	}
5732	+
5733	+	@SuppressWarnings("serial")
5734	+	static final class MapReduceKeysToDoubleTask<K,V>
5735	+	extends BulkTask<K,V,Double> {
5736	+	final ToDoubleFunction<? super K> transformer;
5737	+	final DoubleBinaryOperator reducer;
5738	+	final double basis;
5739	+	double result;
5740	+	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5741	+	MapReduceKeysToDoubleTask
5742	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5743	+	MapReduceKeysToDoubleTask<K,V> nextRight,
5744	+	ToDoubleFunction<? super K> transformer,
5745	+	double basis,
5746	+	DoubleBinaryOperator reducer) {
5747	+	super(p, b, i, f, t); this.nextRight = nextRight;
5748	+	this.transformer = transformer;
5749	+	this.basis = basis; this.reducer = reducer;
5750	+	}
5751	+	public final Double getRawResult() { return result; }
5752	+	public final void compute() {
5753	+	final ToDoubleFunction<? super K> transformer;
5754	+	final DoubleBinaryOperator reducer;
5755	+	if ((transformer = this.transformer) != null &&
5756	+	(reducer = this.reducer) != null) {
5757	+	double r = this.basis;
5758	+	for (int i = baseIndex, f, h; batch > 0 &&
5759	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5760	+	addToPendingCount(1);
5761	+	(rights = new MapReduceKeysToDoubleTask<K,V>
5762	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5763	+	rights, transformer, r, reducer)).fork();
5764	+	}
5765	+	for (Node<K,V> p; (p = advance()) != null; )
5766	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5767	+	result = r;
5768	+	CountedCompleter<?> c;
5769	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5770	+	@SuppressWarnings("unchecked")
5771	+	MapReduceKeysToDoubleTask<K,V>
5772	+	t = (MapReduceKeysToDoubleTask<K,V>)c,
5773	+	s = t.rights;
5774	+	while (s != null) {
5775	+	t.result = reducer.applyAsDouble(t.result, s.result);
5776	+	s = t.rights = s.nextRight;
5777	+	}
5778	+	}
5779	+	}
5780	+	}
5781	+	}
5782	+
5783	+	@SuppressWarnings("serial")
5784	+	static final class MapReduceValuesToDoubleTask<K,V>
5785	+	extends BulkTask<K,V,Double> {
5786	+	final ToDoubleFunction<? super V> transformer;
5787	+	final DoubleBinaryOperator reducer;
5788	+	final double basis;
5789	+	double result;
5790	+	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5791	+	MapReduceValuesToDoubleTask
5792	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5793	+	MapReduceValuesToDoubleTask<K,V> nextRight,
5794	+	ToDoubleFunction<? super V> transformer,
5795	+	double basis,
5796	+	DoubleBinaryOperator reducer) {
5797	+	super(p, b, i, f, t); this.nextRight = nextRight;
5798	+	this.transformer = transformer;
5799	+	this.basis = basis; this.reducer = reducer;
5800	+	}
5801	+	public final Double getRawResult() { return result; }
5802	+	public final void compute() {
5803	+	final ToDoubleFunction<? super V> transformer;
5804	+	final DoubleBinaryOperator reducer;
5805	+	if ((transformer = this.transformer) != null &&
5806	+	(reducer = this.reducer) != null) {
5807	+	double r = this.basis;
5808	+	for (int i = baseIndex, f, h; batch > 0 &&
5809	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5810	+	addToPendingCount(1);
5811	+	(rights = new MapReduceValuesToDoubleTask<K,V>
5812	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5813	+	rights, transformer, r, reducer)).fork();
5814	+	}
5815	+	for (Node<K,V> p; (p = advance()) != null; )
5816	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5817	+	result = r;
5818	+	CountedCompleter<?> c;
5819	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5820	+	@SuppressWarnings("unchecked")
5821	+	MapReduceValuesToDoubleTask<K,V>
5822	+	t = (MapReduceValuesToDoubleTask<K,V>)c,
5823	+	s = t.rights;
5824	+	while (s != null) {
5825	+	t.result = reducer.applyAsDouble(t.result, s.result);
5826	+	s = t.rights = s.nextRight;
5827	+	}
5828	+	}
5829	+	}
5830	+	}
5831	+	}
5832	+
5833	+	@SuppressWarnings("serial")
5834	+	static final class MapReduceEntriesToDoubleTask<K,V>
5835	+	extends BulkTask<K,V,Double> {
5836	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5837	+	final DoubleBinaryOperator reducer;
5838	+	final double basis;
5839	+	double result;
5840	+	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5841	+	MapReduceEntriesToDoubleTask
5842	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5843	+	MapReduceEntriesToDoubleTask<K,V> nextRight,
5844	+	ToDoubleFunction<Map.Entry<K,V>> transformer,
5845	+	double basis,
5846	+	DoubleBinaryOperator reducer) {
5847	+	super(p, b, i, f, t); this.nextRight = nextRight;
5848	+	this.transformer = transformer;
5849	+	this.basis = basis; this.reducer = reducer;
5850	+	}
5851	+	public final Double getRawResult() { return result; }
5852	+	public final void compute() {
5853	+	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5854	+	final DoubleBinaryOperator reducer;
5855	+	if ((transformer = this.transformer) != null &&
5856	+	(reducer = this.reducer) != null) {
5857	+	double r = this.basis;
5858	+	for (int i = baseIndex, f, h; batch > 0 &&
5859	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5860	+	addToPendingCount(1);
5861	+	(rights = new MapReduceEntriesToDoubleTask<K,V>
5862	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5863	+	rights, transformer, r, reducer)).fork();
5864	+	}
5865	+	for (Node<K,V> p; (p = advance()) != null; )
5866	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5867	+	result = r;
5868	+	CountedCompleter<?> c;
5869	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5870	+	@SuppressWarnings("unchecked")
5871	+	MapReduceEntriesToDoubleTask<K,V>
5872	+	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5873	+	s = t.rights;
5874	+	while (s != null) {
5875	+	t.result = reducer.applyAsDouble(t.result, s.result);
5876	+	s = t.rights = s.nextRight;
5877	+	}
5878	+	}
5879	+	}
5880	+	}
5881	+	}
5882	+
5883	+	@SuppressWarnings("serial")
5884	+	static final class MapReduceMappingsToDoubleTask<K,V>
5885	+	extends BulkTask<K,V,Double> {
5886	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5887	+	final DoubleBinaryOperator reducer;
5888	+	final double basis;
5889	+	double result;
5890	+	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5891	+	MapReduceMappingsToDoubleTask
5892	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5893	+	MapReduceMappingsToDoubleTask<K,V> nextRight,
5894	+	ToDoubleBiFunction<? super K, ? super V> transformer,
5895	+	double basis,
5896	+	DoubleBinaryOperator reducer) {
5897	+	super(p, b, i, f, t); this.nextRight = nextRight;
5898	+	this.transformer = transformer;
5899	+	this.basis = basis; this.reducer = reducer;
5900	+	}
5901	+	public final Double getRawResult() { return result; }
5902	+	public final void compute() {
5903	+	final ToDoubleBiFunction<? super K, ? super V> transformer;
5904	+	final DoubleBinaryOperator reducer;
5905	+	if ((transformer = this.transformer) != null &&
5906	+	(reducer = this.reducer) != null) {
5907	+	double r = this.basis;
5908	+	for (int i = baseIndex, f, h; batch > 0 &&
5909	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5910	+	addToPendingCount(1);
5911	+	(rights = new MapReduceMappingsToDoubleTask<K,V>
5912	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5913	+	rights, transformer, r, reducer)).fork();
5914	+	}
5915	+	for (Node<K,V> p; (p = advance()) != null; )
5916	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5917	+	result = r;
5918	+	CountedCompleter<?> c;
5919	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5920	+	@SuppressWarnings("unchecked")
5921	+	MapReduceMappingsToDoubleTask<K,V>
5922	+	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5923	+	s = t.rights;
5924	+	while (s != null) {
5925	+	t.result = reducer.applyAsDouble(t.result, s.result);
5926	+	s = t.rights = s.nextRight;
5927	+	}
5928	+	}
5929	+	}
5930	+	}
5931	+	}
5932	+
5933	+	@SuppressWarnings("serial")
5934	+	static final class MapReduceKeysToLongTask<K,V>
5935	+	extends BulkTask<K,V,Long> {
5936	+	final ToLongFunction<? super K> transformer;
5937	+	final LongBinaryOperator reducer;
5938	+	final long basis;
5939	+	long result;
5940	+	MapReduceKeysToLongTask<K,V> rights, nextRight;
5941	+	MapReduceKeysToLongTask
5942	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5943	+	MapReduceKeysToLongTask<K,V> nextRight,
5944	+	ToLongFunction<? super K> transformer,
5945	+	long basis,
5946	+	LongBinaryOperator reducer) {
5947	+	super(p, b, i, f, t); this.nextRight = nextRight;
5948	+	this.transformer = transformer;
5949	+	this.basis = basis; this.reducer = reducer;
5950	+	}
5951	+	public final Long getRawResult() { return result; }
5952	+	public final void compute() {
5953	+	final ToLongFunction<? super K> transformer;
5954	+	final LongBinaryOperator reducer;
5955	+	if ((transformer = this.transformer) != null &&
5956	+	(reducer = this.reducer) != null) {
5957	+	long r = this.basis;
5958	+	for (int i = baseIndex, f, h; batch > 0 &&
5959	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5960	+	addToPendingCount(1);
5961	+	(rights = new MapReduceKeysToLongTask<K,V>
5962	+	(this, batch >>>= 1, baseLimit = h, f, tab,
5963	+	rights, transformer, r, reducer)).fork();
5964	+	}
5965	+	for (Node<K,V> p; (p = advance()) != null; )
5966	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5967	+	result = r;
5968	+	CountedCompleter<?> c;
5969	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5970	+	@SuppressWarnings("unchecked")
5971	+	MapReduceKeysToLongTask<K,V>
5972	+	t = (MapReduceKeysToLongTask<K,V>)c,
5973	+	s = t.rights;
5974	+	while (s != null) {
5975	+	t.result = reducer.applyAsLong(t.result, s.result);
5976	+	s = t.rights = s.nextRight;
5977	+	}
5978	+	}
5979	+	}
5980	+	}
5981	+	}
5982	+
5983	+	@SuppressWarnings("serial")
5984	+	static final class MapReduceValuesToLongTask<K,V>
5985	+	extends BulkTask<K,V,Long> {
5986	+	final ToLongFunction<? super V> transformer;
5987	+	final LongBinaryOperator reducer;
5988	+	final long basis;
5989	+	long result;
5990	+	MapReduceValuesToLongTask<K,V> rights, nextRight;
5991	+	MapReduceValuesToLongTask
5992	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5993	+	MapReduceValuesToLongTask<K,V> nextRight,
5994	+	ToLongFunction<? super V> transformer,
5995	+	long basis,
5996	+	LongBinaryOperator reducer) {
5997	+	super(p, b, i, f, t); this.nextRight = nextRight;
5998	+	this.transformer = transformer;
5999	+	this.basis = basis; this.reducer = reducer;
6000	+	}
6001	+	public final Long getRawResult() { return result; }
6002	+	public final void compute() {
6003	+	final ToLongFunction<? super V> transformer;
6004	+	final LongBinaryOperator reducer;
6005	+	if ((transformer = this.transformer) != null &&
6006	+	(reducer = this.reducer) != null) {
6007	+	long r = this.basis;
6008	+	for (int i = baseIndex, f, h; batch > 0 &&
6009	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6010	+	addToPendingCount(1);
6011	+	(rights = new MapReduceValuesToLongTask<K,V>
6012	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6013	+	rights, transformer, r, reducer)).fork();
6014	+	}
6015	+	for (Node<K,V> p; (p = advance()) != null; )
6016	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
6017	+	result = r;
6018	+	CountedCompleter<?> c;
6019	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6020	+	@SuppressWarnings("unchecked")
6021	+	MapReduceValuesToLongTask<K,V>
6022	+	t = (MapReduceValuesToLongTask<K,V>)c,
6023	+	s = t.rights;
6024	+	while (s != null) {
6025	+	t.result = reducer.applyAsLong(t.result, s.result);
6026	+	s = t.rights = s.nextRight;
6027	+	}
6028	+	}
6029	+	}
6030	+	}
6031	+	}
6032	+
6033	+	@SuppressWarnings("serial")
6034	+	static final class MapReduceEntriesToLongTask<K,V>
6035	+	extends BulkTask<K,V,Long> {
6036	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6037	+	final LongBinaryOperator reducer;
6038	+	final long basis;
6039	+	long result;
6040	+	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6041	+	MapReduceEntriesToLongTask
6042	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6043	+	MapReduceEntriesToLongTask<K,V> nextRight,
6044	+	ToLongFunction<Map.Entry<K,V>> transformer,
6045	+	long basis,
6046	+	LongBinaryOperator reducer) {
6047	+	super(p, b, i, f, t); this.nextRight = nextRight;
6048	+	this.transformer = transformer;
6049	+	this.basis = basis; this.reducer = reducer;
6050	+	}
6051	+	public final Long getRawResult() { return result; }
6052	+	public final void compute() {
6053	+	final ToLongFunction<Map.Entry<K,V>> transformer;
6054	+	final LongBinaryOperator reducer;
6055	+	if ((transformer = this.transformer) != null &&
6056	+	(reducer = this.reducer) != null) {
6057	+	long r = this.basis;
6058	+	for (int i = baseIndex, f, h; batch > 0 &&
6059	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6060	+	addToPendingCount(1);
6061	+	(rights = new MapReduceEntriesToLongTask<K,V>
6062	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6063	+	rights, transformer, r, reducer)).fork();
6064	+	}
6065	+	for (Node<K,V> p; (p = advance()) != null; )
6066	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6067	+	result = r;
6068	+	CountedCompleter<?> c;
6069	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6070	+	@SuppressWarnings("unchecked")
6071	+	MapReduceEntriesToLongTask<K,V>
6072	+	t = (MapReduceEntriesToLongTask<K,V>)c,
6073	+	s = t.rights;
6074	+	while (s != null) {
6075	+	t.result = reducer.applyAsLong(t.result, s.result);
6076	+	s = t.rights = s.nextRight;
6077	+	}
6078	+	}
6079	+	}
6080	+	}
6081	+	}
6082	+
6083	+	@SuppressWarnings("serial")
6084	+	static final class MapReduceMappingsToLongTask<K,V>
6085	+	extends BulkTask<K,V,Long> {
6086	+	final ToLongBiFunction<? super K, ? super V> transformer;
6087	+	final LongBinaryOperator reducer;
6088	+	final long basis;
6089	+	long result;
6090	+	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6091	+	MapReduceMappingsToLongTask
6092	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6093	+	MapReduceMappingsToLongTask<K,V> nextRight,
6094	+	ToLongBiFunction<? super K, ? super V> transformer,
6095	+	long basis,
6096	+	LongBinaryOperator reducer) {
6097	+	super(p, b, i, f, t); this.nextRight = nextRight;
6098	+	this.transformer = transformer;
6099	+	this.basis = basis; this.reducer = reducer;
6100	+	}
6101	+	public final Long getRawResult() { return result; }
6102	+	public final void compute() {
6103	+	final ToLongBiFunction<? super K, ? super V> transformer;
6104	+	final LongBinaryOperator reducer;
6105	+	if ((transformer = this.transformer) != null &&
6106	+	(reducer = this.reducer) != null) {
6107	+	long r = this.basis;
6108	+	for (int i = baseIndex, f, h; batch > 0 &&
6109	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6110	+	addToPendingCount(1);
6111	+	(rights = new MapReduceMappingsToLongTask<K,V>
6112	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6113	+	rights, transformer, r, reducer)).fork();
6114	+	}
6115	+	for (Node<K,V> p; (p = advance()) != null; )
6116	+	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6117	+	result = r;
6118	+	CountedCompleter<?> c;
6119	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6120	+	@SuppressWarnings("unchecked")
6121	+	MapReduceMappingsToLongTask<K,V>
6122	+	t = (MapReduceMappingsToLongTask<K,V>)c,
6123	+	s = t.rights;
6124	+	while (s != null) {
6125	+	t.result = reducer.applyAsLong(t.result, s.result);
6126	+	s = t.rights = s.nextRight;
6127	+	}
6128	+	}
6129	+	}
6130	+	}
6131	+	}
6132	+
6133	+	@SuppressWarnings("serial")
6134	+	static final class MapReduceKeysToIntTask<K,V>
6135	+	extends BulkTask<K,V,Integer> {
6136	+	final ToIntFunction<? super K> transformer;
6137	+	final IntBinaryOperator reducer;
6138	+	final int basis;
6139	+	int result;
6140	+	MapReduceKeysToIntTask<K,V> rights, nextRight;
6141	+	MapReduceKeysToIntTask
6142	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6143	+	MapReduceKeysToIntTask<K,V> nextRight,
6144	+	ToIntFunction<? super K> transformer,
6145	+	int basis,
6146	+	IntBinaryOperator reducer) {
6147	+	super(p, b, i, f, t); this.nextRight = nextRight;
6148	+	this.transformer = transformer;
6149	+	this.basis = basis; this.reducer = reducer;
6150	+	}
6151	+	public final Integer getRawResult() { return result; }
6152	+	public final void compute() {
6153	+	final ToIntFunction<? super K> transformer;
6154	+	final IntBinaryOperator reducer;
6155	+	if ((transformer = this.transformer) != null &&
6156	+	(reducer = this.reducer) != null) {
6157	+	int r = this.basis;
6158	+	for (int i = baseIndex, f, h; batch > 0 &&
6159	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6160	+	addToPendingCount(1);
6161	+	(rights = new MapReduceKeysToIntTask<K,V>
6162	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6163	+	rights, transformer, r, reducer)).fork();
6164	+	}
6165	+	for (Node<K,V> p; (p = advance()) != null; )
6166	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6167	+	result = r;
6168	+	CountedCompleter<?> c;
6169	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6170	+	@SuppressWarnings("unchecked")
6171	+	MapReduceKeysToIntTask<K,V>
6172	+	t = (MapReduceKeysToIntTask<K,V>)c,
6173	+	s = t.rights;
6174	+	while (s != null) {
6175	+	t.result = reducer.applyAsInt(t.result, s.result);
6176	+	s = t.rights = s.nextRight;
6177	+	}
6178	+	}
6179	+	}
6180	+	}
6181	+	}
6182	+
6183	+	@SuppressWarnings("serial")
6184	+	static final class MapReduceValuesToIntTask<K,V>
6185	+	extends BulkTask<K,V,Integer> {
6186	+	final ToIntFunction<? super V> transformer;
6187	+	final IntBinaryOperator reducer;
6188	+	final int basis;
6189	+	int result;
6190	+	MapReduceValuesToIntTask<K,V> rights, nextRight;
6191	+	MapReduceValuesToIntTask
6192	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6193	+	MapReduceValuesToIntTask<K,V> nextRight,
6194	+	ToIntFunction<? super V> transformer,
6195	+	int basis,
6196	+	IntBinaryOperator reducer) {
6197	+	super(p, b, i, f, t); this.nextRight = nextRight;
6198	+	this.transformer = transformer;
6199	+	this.basis = basis; this.reducer = reducer;
6200	+	}
6201	+	public final Integer getRawResult() { return result; }
6202	+	public final void compute() {
6203	+	final ToIntFunction<? super V> transformer;
6204	+	final IntBinaryOperator reducer;
6205	+	if ((transformer = this.transformer) != null &&
6206	+	(reducer = this.reducer) != null) {
6207	+	int r = this.basis;
6208	+	for (int i = baseIndex, f, h; batch > 0 &&
6209	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6210	+	addToPendingCount(1);
6211	+	(rights = new MapReduceValuesToIntTask<K,V>
6212	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6213	+	rights, transformer, r, reducer)).fork();
6214	+	}
6215	+	for (Node<K,V> p; (p = advance()) != null; )
6216	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6217	+	result = r;
6218	+	CountedCompleter<?> c;
6219	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6220	+	@SuppressWarnings("unchecked")
6221	+	MapReduceValuesToIntTask<K,V>
6222	+	t = (MapReduceValuesToIntTask<K,V>)c,
6223	+	s = t.rights;
6224	+	while (s != null) {
6225	+	t.result = reducer.applyAsInt(t.result, s.result);
6226	+	s = t.rights = s.nextRight;
6227	+	}
6228	+	}
6229	+	}
6230	+	}
6231	+	}
6232	+
6233	+	@SuppressWarnings("serial")
6234	+	static final class MapReduceEntriesToIntTask<K,V>
6235	+	extends BulkTask<K,V,Integer> {
6236	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6237	+	final IntBinaryOperator reducer;
6238	+	final int basis;
6239	+	int result;
6240	+	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6241	+	MapReduceEntriesToIntTask
6242	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6243	+	MapReduceEntriesToIntTask<K,V> nextRight,
6244	+	ToIntFunction<Map.Entry<K,V>> transformer,
6245	+	int basis,
6246	+	IntBinaryOperator reducer) {
6247	+	super(p, b, i, f, t); this.nextRight = nextRight;
6248	+	this.transformer = transformer;
6249	+	this.basis = basis; this.reducer = reducer;
6250	+	}
6251	+	public final Integer getRawResult() { return result; }
6252	+	public final void compute() {
6253	+	final ToIntFunction<Map.Entry<K,V>> transformer;
6254	+	final IntBinaryOperator reducer;
6255	+	if ((transformer = this.transformer) != null &&
6256	+	(reducer = this.reducer) != null) {
6257	+	int r = this.basis;
6258	+	for (int i = baseIndex, f, h; batch > 0 &&
6259	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6260	+	addToPendingCount(1);
6261	+	(rights = new MapReduceEntriesToIntTask<K,V>
6262	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6263	+	rights, transformer, r, reducer)).fork();
6264	+	}
6265	+	for (Node<K,V> p; (p = advance()) != null; )
6266	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6267	+	result = r;
6268	+	CountedCompleter<?> c;
6269	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6270	+	@SuppressWarnings("unchecked")
6271	+	MapReduceEntriesToIntTask<K,V>
6272	+	t = (MapReduceEntriesToIntTask<K,V>)c,
6273	+	s = t.rights;
6274	+	while (s != null) {
6275	+	t.result = reducer.applyAsInt(t.result, s.result);
6276	+	s = t.rights = s.nextRight;
6277	+	}
6278	+	}
6279	+	}
6280	+	}
6281	+	}
6282	+
6283	+	@SuppressWarnings("serial")
6284	+	static final class MapReduceMappingsToIntTask<K,V>
6285	+	extends BulkTask<K,V,Integer> {
6286	+	final ToIntBiFunction<? super K, ? super V> transformer;
6287	+	final IntBinaryOperator reducer;
6288	+	final int basis;
6289	+	int result;
6290	+	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6291	+	MapReduceMappingsToIntTask
6292	+	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6293	+	MapReduceMappingsToIntTask<K,V> nextRight,
6294	+	ToIntBiFunction<? super K, ? super V> transformer,
6295	+	int basis,
6296	+	IntBinaryOperator reducer) {
6297	+	super(p, b, i, f, t); this.nextRight = nextRight;
6298	+	this.transformer = transformer;
6299	+	this.basis = basis; this.reducer = reducer;
6300	+	}
6301	+	public final Integer getRawResult() { return result; }
6302	+	public final void compute() {
6303	+	final ToIntBiFunction<? super K, ? super V> transformer;
6304	+	final IntBinaryOperator reducer;
6305	+	if ((transformer = this.transformer) != null &&
6306	+	(reducer = this.reducer) != null) {
6307	+	int r = this.basis;
6308	+	for (int i = baseIndex, f, h; batch > 0 &&
6309	+	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6310	+	addToPendingCount(1);
6311	+	(rights = new MapReduceMappingsToIntTask<K,V>
6312	+	(this, batch >>>= 1, baseLimit = h, f, tab,
6313	+	rights, transformer, r, reducer)).fork();
6314	+	}
6315	+	for (Node<K,V> p; (p = advance()) != null; )
6316	+	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6317	+	result = r;
6318	+	CountedCompleter<?> c;
6319	+	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6320	+	@SuppressWarnings("unchecked")
6321	+	MapReduceMappingsToIntTask<K,V>
6322	+	t = (MapReduceMappingsToIntTask<K,V>)c,
6323	+	s = t.rights;
6324	+	while (s != null) {
6325	+	t.result = reducer.applyAsInt(t.result, s.result);
6326	+	s = t.rights = s.nextRight;
6327	+	}
6328	+	}
6329	+	}
6330	+	}
6331	+	}
6332	+
6333	+	// Unsafe mechanics
6334	+	private static final Unsafe U = Unsafe.getUnsafe();
6335	+	private static final long SIZECTL;
6336	+	private static final long TRANSFERINDEX;
6337	+	private static final long BASECOUNT;
6338	+	private static final long CELLSBUSY;
6339	+	private static final long CELLVALUE;
6340	+	private static final int ABASE;
6341	+	private static final int ASHIFT;
6342	+
6343	+	static {
6344	+	try {
6345	+	SIZECTL = U.objectFieldOffset
6346	+	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6347	+	TRANSFERINDEX = U.objectFieldOffset
6348	+	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6349	+	BASECOUNT = U.objectFieldOffset
6350	+	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6351	+	CELLSBUSY = U.objectFieldOffset
6352	+	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6353	+
6354	+	CELLVALUE = U.objectFieldOffset
6355	+	(CounterCell.class.getDeclaredField("value"));
6356	+
6357	+	ABASE = U.arrayBaseOffset(Node[].class);
6358	+	int scale = U.arrayIndexScale(Node[].class);
6359	+	if ((scale & (scale - 1)) != 0)
6360	+	throw new ExceptionInInitializerError("array index scale not a power of two");
6361	+	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6362	+	} catch (ReflectiveOperationException e) {
6363	+	throw new ExceptionInInitializerError(e);
6364	+	}
6365	+
6366	+	// Reduce the risk of rare disastrous classloading in first call to
6367	+	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6368	+	Class<?> ensureLoaded = LockSupport.class;
6369	+
6370	+	// Eager class load observed to help JIT during startup
6371	+	ensureLoaded = ReservationNode.class;
6372	+	}
6373		}

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