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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.110 by jsr166, Wed Apr 27 14:06:30 2011 UTC vs.
Revision 1.205 by dl, Thu Apr 11 20:13:38 2013 UTC

#	Line 5 | Line 5
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>	import java.util.concurrent.ForkJoinPool;
9	>	import java.util.concurrent.CountedCompleter;
10	>	import java.util.Spliterator;
11	>	import java.util.stream.Stream;
12	>	import java.util.stream.Streams;
13	>	import java.util.function.*;
14	>	import java.util.function.Consumer;
15	>	import java.util.function.Function;
16	>	import java.util.function.BiFunction;
17	>
18	>	import java.util.Comparator;
19	>	import java.util.Arrays;
20	>	import java.util.Map;
21	>	import java.util.Set;
22	>	import java.util.Collection;
23	>	import java.util.AbstractMap;
24	>	import java.util.AbstractSet;
25	>	import java.util.AbstractCollection;
26	>	import java.util.Hashtable;
27	>	import java.util.HashMap;
28	>	import java.util.Iterator;
29	>	import java.util.Enumeration;
30	>	import java.util.ConcurrentModificationException;
31	>	import java.util.NoSuchElementException;
32	>	import java.util.concurrent.ConcurrentMap;
33	>	import java.util.concurrent.locks.AbstractQueuedSynchronizer;
34	>	import java.util.concurrent.atomic.AtomicInteger;
35	>	import java.util.concurrent.atomic.AtomicReference;
36		import java.io.Serializable;
37	<	import java.io.IOException;
38	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
37	>	import java.lang.reflect.Type;
38	>	import java.lang.reflect.ParameterizedType;
39
40		/**
41		* A hash table supporting full concurrency of retrievals and
42	<	* adjustable expected concurrency for updates. This class obeys the
42	>	* high expected concurrency for updates. This class obeys the
43		* same functional specification as {@link java.util.Hashtable}, and
44		* includes versions of methods corresponding to each method of
45	<	* <tt>Hashtable</tt>. However, even though all operations are
45	>	* {@code Hashtable}. However, even though all operations are
46		* thread-safe, retrieval operations do <em>not</em> entail locking,
47		* and there is <em>not</em> any support for locking the entire table
48		* in a way that prevents all access.  This class is fully
49	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
49	>	* interoperable with {@code Hashtable} in programs that rely on its
50		* thread safety but not on its synchronization details.
51		*
52	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
53	<	* block, so may overlap with update operations (including
54	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
55	<	* of the most recently <em>completed</em> update operations holding
56	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
57	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
58	<	* removal of only some entries.  Similarly, Iterators and
59	<	* Enumerations return elements reflecting the state of the hash table
60	<	* at some point at or since the creation of the iterator/enumeration.
61	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
62	<	* However, iterators are designed to be used by only one thread at a time.
63	<	*
64	<	* <p> The allowed concurrency among update operations is guided by
65	<	* the optional <tt>concurrencyLevel</tt> constructor argument
66	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
67	<	* table is internally partitioned to try to permit the indicated
68	<	* number of concurrent updates without contention. Because placement
69	<	* in hash tables is essentially random, the actual concurrency will
70	<	* vary.  Ideally, you should choose a value to accommodate as many
71	<	* threads as will ever concurrently modify the table. Using a
72	<	* significantly higher value than you need can waste space and time,
73	<	* and a significantly lower value can lead to thread contention. But
74	<	* overestimates and underestimates within an order of magnitude do
75	<	* not usually have much noticeable impact. A value of one is
76	<	* appropriate when it is known that only one thread will modify and
77	<	* all others will only read. Also, resizing this or any other kind of
78	<	* hash table is a relatively slow operation, so, when possible, it is
79	<	* a good idea to provide estimates of expected table sizes in
80	<	* constructors.
52	>	* <p>Retrieval operations (including {@code get}) generally do not
53	>	* block, so may overlap with update operations (including {@code put}
54	>	* and {@code remove}). Retrievals reflect the results of the most
55	>	* recently <em>completed</em> update operations holding upon their
56	>	* onset. (More formally, an update operation for a given key bears a
57	>	* <em>happens-before</em> relation with any (non-null) retrieval for
58	>	* that key reporting the updated value.)  For aggregate operations
59	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
60	>	* reflect insertion or removal of only some entries.  Similarly,
61	>	* Iterators and Enumerations return elements reflecting the state of
62	>	* the hash table at some point at or since the creation of the
63	>	* iterator/enumeration.  They do <em>not</em> throw {@link
64	>	* ConcurrentModificationException}.  However, iterators are designed
65	>	* to be used by only one thread at a time.  Bear in mind that the
66	>	* results of aggregate status methods including {@code size}, {@code
67	>	* isEmpty}, and {@code containsValue} are typically useful only when
68	>	* a map is not undergoing concurrent updates in other threads.
69	>	* Otherwise the results of these methods reflect transient states
70	>	* that may be adequate for monitoring or estimation purposes, but not
71	>	* for program control.
72	>	*
73	>	* <p>The table is dynamically expanded when there are too many
74	>	* collisions (i.e., keys that have distinct hash codes but fall into
75	>	* the same slot modulo the table size), with the expected average
76	>	* effect of maintaining roughly two bins per mapping (corresponding
77	>	* to a 0.75 load factor threshold for resizing). There may be much
78	>	* variance around this average as mappings are added and removed, but
79	>	* overall, this maintains a commonly accepted time/space tradeoff for
80	>	* hash tables.  However, resizing this or any other kind of hash
81	>	* table may be a relatively slow operation. When possible, it is a
82	>	* good idea to provide a size estimate as an optional {@code
83	>	* initialCapacity} constructor argument. An additional optional
84	>	* {@code loadFactor} constructor argument provides a further means of
85	>	* customizing initial table capacity by specifying the table density
86	>	* to be used in calculating the amount of space to allocate for the
87	>	* given number of elements.  Also, for compatibility with previous
88	>	* versions of this class, constructors may optionally specify an
89	>	* expected {@code concurrencyLevel} as an additional hint for
90	>	* internal sizing.  Note that using many keys with exactly the same
91	>	* {@code hashCode()} is a sure way to slow down performance of any
92	>	* hash table.
93	>	*
94	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
95	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
96	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
97	>	* mapped values are (perhaps transiently) not used or all take the
98	>	* same mapping value.
99	>	*
100	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
101	>	* form of histogram or multiset) by using {@link
102	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
103	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
104	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
105	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
106		*
107		* <p>This class and its views and iterators implement all of the
108		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
109		* interfaces.
110		*
111	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
112	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
111	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
112	>	* does <em>not</em> allow {@code null} to be used as a key or value.
113	>	*
114	>	* <p>ConcurrentHashMaps support sequential and parallel operations
115	>	* bulk operations. (Parallel forms use the {@link
116	>	* ForkJoinPool#commonPool()}). Tasks that may be used in other
117	>	* contexts are available in class {@link ForkJoinTasks}. These
118	>	* operations are designed to be safely, and often sensibly, applied
119	>	* even with maps that are being concurrently updated by other
120	>	* threads; for example, when computing a snapshot summary of the
121	>	* values in a shared registry.  There are three kinds of operation,
122	>	* each with four forms, accepting functions with Keys, Values,
123	>	* Entries, and (Key, Value) arguments and/or return values. Because
124	>	* the elements of a ConcurrentHashMap are not ordered in any
125	>	* particular way, and may be processed in different orders in
126	>	* different parallel executions, the correctness of supplied
127	>	* functions should not depend on any ordering, or on any other
128	>	* objects or values that may transiently change while computation is
129	>	* in progress; and except for forEach actions, should ideally be
130	>	* side-effect-free.
131	>	*
132	>	* <ul>
133	>	* <li> forEach: Perform a given action on each element.
134	>	* A variant form applies a given transformation on each element
135	>	* before performing the action.</li>
136	>	*
137	>	* <li> search: Return the first available non-null result of
138	>	* applying a given function on each element; skipping further
139	>	* search when a result is found.</li>
140	>	*
141	>	* <li> reduce: Accumulate each element.  The supplied reduction
142	>	* function cannot rely on ordering (more formally, it should be
143	>	* both associative and commutative).  There are five variants:
144	>	*
145	>	* <ul>
146	>	*
147	>	* <li> Plain reductions. (There is not a form of this method for
148	>	* (key, value) function arguments since there is no corresponding
149	>	* return type.)</li>
150	>	*
151	>	* <li> Mapped reductions that accumulate the results of a given
152	>	* function applied to each element.</li>
153	>	*
154	>	* <li> Reductions to scalar doubles, longs, and ints, using a
155	>	* given basis value.</li>
156	>	*
157	>	* </ul>
158	>	* </li>
159	>	* </ul>
160	>	*
161	>	* <p>The concurrency properties of bulk operations follow
162	>	* from those of ConcurrentHashMap: Any non-null result returned
163	>	* from {@code get(key)} and related access methods bears a
164	>	* happens-before relation with the associated insertion or
165	>	* update.  The result of any bulk operation reflects the
166	>	* composition of these per-element relations (but is not
167	>	* necessarily atomic with respect to the map as a whole unless it
168	>	* is somehow known to be quiescent).  Conversely, because keys
169	>	* and values in the map are never null, null serves as a reliable
170	>	* atomic indicator of the current lack of any result.  To
171	>	* maintain this property, null serves as an implicit basis for
172	>	* all non-scalar reduction operations. For the double, long, and
173	>	* int versions, the basis should be one that, when combined with
174	>	* any other value, returns that other value (more formally, it
175	>	* should be the identity element for the reduction). Most common
176	>	* reductions have these properties; for example, computing a sum
177	>	* with basis 0 or a minimum with basis MAX_VALUE.
178	>	*
179	>	* <p>Search and transformation functions provided as arguments
180	>	* should similarly return null to indicate the lack of any result
181	>	* (in which case it is not used). In the case of mapped
182	>	* reductions, this also enables transformations to serve as
183	>	* filters, returning null (or, in the case of primitive
184	>	* specializations, the identity basis) if the element should not
185	>	* be combined. You can create compound transformations and
186	>	* filterings by composing them yourself under this "null means
187	>	* there is nothing there now" rule before using them in search or
188	>	* reduce operations.
189	>	*
190	>	* <p>Methods accepting and/or returning Entry arguments maintain
191	>	* key-value associations. They may be useful for example when
192	>	* finding the key for the greatest value. Note that "plain" Entry
193	>	* arguments can be supplied using {@code new
194	>	* AbstractMap.SimpleEntry(k,v)}.
195	>	*
196	>	* <p>Bulk operations may complete abruptly, throwing an
197	>	* exception encountered in the application of a supplied
198	>	* function. Bear in mind when handling such exceptions that other
199	>	* concurrently executing functions could also have thrown
200	>	* exceptions, or would have done so if the first exception had
201	>	* not occurred.
202	>	*
203	>	* <p>Speedups for parallel compared to sequential forms are common
204	>	* but not guaranteed.  Parallel operations involving brief functions
205	>	* on small maps may execute more slowly than sequential forms if the
206	>	* underlying work to parallelize the computation is more expensive
207	>	* than the computation itself.  Similarly, parallelization may not
208	>	* lead to much actual parallelism if all processors are busy
209	>	* performing unrelated tasks.
210	>	*
211	>	* <p>All arguments to all task methods must be non-null.
212		*
213		* <p>This class is a member of the
214		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 219 | import java.io.ObjectOutputStream;
219		* @param <K> the type of keys maintained by this map
220		* @param <V> the type of mapped values
221		*/
222	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
223	<	implements ConcurrentMap<K, V>, Serializable {
222	>	public class ConcurrentHashMap<K,V>
223	>	implements ConcurrentMap<K,V>, Serializable {
224		private static final long serialVersionUID = 7249069246763182397L;
225
226		/*
227	<	* The basic strategy is to subdivide the table among Segments,
228	<	* each of which itself is a concurrently readable hash table.  To
229	<	* reduce footprint, all but one segments are constructed only
230	<	* when first needed (see ensureSegment). To maintain visibility
231	<	* in the presence of lazy construction, accesses to segments as
232	<	* well as elements of segment's table must use volatile access,
233	<	* which is done via Unsafe within methods segmentAt etc
234	<	* below. These provide the functionality of AtomicReferenceArrays
235	<	* but reduce the levels of indirection. Additionally,
236	<	* volatile-writes of table elements and entry "next" fields
237	<	* within locked operations use the cheaper "lazySet" forms of
238	<	* writes (via putOrderedObject) because these writes are always
239	<	* followed by lock releases that maintain sequential consistency
240	<	* of table updates.
241	<	*
242	<	* Historical note: The previous version of this class relied
243	<	* heavily on "final" fields, which avoided some volatile reads at
244	<	* the expense of a large initial footprint.  Some remnants of
245	<	* that design (including forced construction of segment 0) exist
246	<	* to ensure serialization compatibility.
227	>	* Overview:
228	>	*
229	>	* The primary design goal of this hash table is to maintain
230	>	* concurrent readability (typically method get(), but also
231	>	* iterators and related methods) while minimizing update
232	>	* contention. Secondary goals are to keep space consumption about
233	>	* the same or better than java.util.HashMap, and to support high
234	>	* initial insertion rates on an empty table by many threads.
235	>	*
236	>	* Each key-value mapping is held in a Node.  Because Node key
237	>	* fields can contain special values, they are defined using plain
238	>	* Object types (not type "K"). This leads to a lot of explicit
239	>	* casting (and many explicit warning suppressions to tell
240	>	* compilers not to complain about it). It also allows some of the
241	>	* public methods to be factored into a smaller number of internal
242	>	* methods (although sadly not so for the five variants of
243	>	* put-related operations). The validation-based approach
244	>	* explained below leads to a lot of code sprawl because
245	>	* retry-control precludes factoring into smaller methods.
246	>	*
247	>	* The table is lazily initialized to a power-of-two size upon the
248	>	* first insertion.  Each bin in the table normally contains a
249	>	* list of Nodes (most often, the list has only zero or one Node).
250	>	* Table accesses require volatile/atomic reads, writes, and
251	>	* CASes.  Because there is no other way to arrange this without
252	>	* adding further indirections, we use intrinsics
253	>	* (sun.misc.Unsafe) operations.  The lists of nodes within bins
254	>	* are always accurately traversable under volatile reads, so long
255	>	* as lookups check hash code and non-nullness of value before
256	>	* checking key equality.
257	>	*
258	>	* We use the top (sign) bit of Node hash fields for control
259	>	* purposes -- it is available anyway because of addressing
260	>	* constraints.  Nodes with negative hash fields are forwarding
261	>	* nodes to either TreeBins or resized tables.  The lower 31 bits
262	>	* of each normal Node's hash field contain a transformation of
263	>	* the key's hash code.
264	>	*
265	>	* Insertion (via put or its variants) of the first node in an
266	>	* empty bin is performed by just CASing it to the bin.  This is
267	>	* by far the most common case for put operations under most
268	>	* key/hash distributions.  Other update operations (insert,
269	>	* delete, and replace) require locks.  We do not want to waste
270	>	* the space required to associate a distinct lock object with
271	>	* each bin, so instead use the first node of a bin list itself as
272	>	* a lock. Locking support for these locks relies on builtin
273	>	* "synchronized" monitors.
274	>	*
275	>	* Using the first node of a list as a lock does not by itself
276	>	* suffice though: When a node is locked, any update must first
277	>	* validate that it is still the first node after locking it, and
278	>	* retry if not. Because new nodes are always appended to lists,
279	>	* once a node is first in a bin, it remains first until deleted
280	>	* or the bin becomes invalidated (upon resizing).  However,
281	>	* operations that only conditionally update may inspect nodes
282	>	* until the point of update. This is a converse of sorts to the
283	>	* lazy locking technique described by Herlihy & Shavit.
284	>	*
285	>	* The main disadvantage of per-bin locks is that other update
286	>	* operations on other nodes in a bin list protected by the same
287	>	* lock can stall, for example when user equals() or mapping
288	>	* functions take a long time.  However, statistically, under
289	>	* random hash codes, this is not a common problem.  Ideally, the
290	>	* frequency of nodes in bins follows a Poisson distribution
291	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
292	>	* parameter of about 0.5 on average, given the resizing threshold
293	>	* of 0.75, although with a large variance because of resizing
294	>	* granularity. Ignoring variance, the expected occurrences of
295	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
296	>	* first values are:
297	>	*
298	>	* 0:    0.60653066
299	>	* 1:    0.30326533
300	>	* 2:    0.07581633
301	>	* 3:    0.01263606
302	>	* 4:    0.00157952
303	>	* 5:    0.00015795
304	>	* 6:    0.00001316
305	>	* 7:    0.00000094
306	>	* 8:    0.00000006
307	>	* more: less than 1 in ten million
308	>	*
309	>	* Lock contention probability for two threads accessing distinct
310	>	* elements is roughly 1 / (8 * #elements) under random hashes.
311	>	*
312	>	* Actual hash code distributions encountered in practice
313	>	* sometimes deviate significantly from uniform randomness.  This
314	>	* includes the case when N > (1<<30), so some keys MUST collide.
315	>	* Similarly for dumb or hostile usages in which multiple keys are
316	>	* designed to have identical hash codes. Also, although we guard
317	>	* against the worst effects of this (see method spread), sets of
318	>	* hashes may differ only in bits that do not impact their bin
319	>	* index for a given power-of-two mask.  So we use a secondary
320	>	* strategy that applies when the number of nodes in a bin exceeds
321	>	* a threshold, and at least one of the keys implements
322	>	* Comparable.  These TreeBins use a balanced tree to hold nodes
323	>	* (a specialized form of red-black trees), bounding search time
324	>	* to O(log N).  Each search step in a TreeBin is around twice as
325	>	* slow as in a regular list, but given that N cannot exceed
326	>	* (1<<64) (before running out of addresses) this bounds search
327	>	* steps, lock hold times, etc, to reasonable constants (roughly
328	>	* 100 nodes inspected per operation worst case) so long as keys
329	>	* are Comparable (which is very common -- String, Long, etc).
330	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
331	>	* traversal pointers as regular nodes, so can be traversed in
332	>	* iterators in the same way.
333	>	*
334	>	* The table is resized when occupancy exceeds a percentage
335	>	* threshold (nominally, 0.75, but see below).  Any thread
336	>	* noticing an overfull bin may assist in resizing after the
337	>	* initiating thread allocates and sets up the replacement
338	>	* array. However, rather than stalling, these other threads may
339	>	* proceed with insertions etc.  The use of TreeBins shields us
340	>	* from the worst case effects of overfilling while resizes are in
341	>	* progress.  Resizing proceeds by transferring bins, one by one,
342	>	* from the table to the next table. To enable concurrency, the
343	>	* next table must be (incrementally) prefilled with place-holders
344	>	* serving as reverse forwarders to the old table.  Because we are
345	>	* using power-of-two expansion, the elements from each bin must
346	>	* either stay at same index, or move with a power of two
347	>	* offset. We eliminate unnecessary node creation by catching
348	>	* cases where old nodes can be reused because their next fields
349	>	* won't change.  On average, only about one-sixth of them need
350	>	* cloning when a table doubles. The nodes they replace will be
351	>	* garbage collectable as soon as they are no longer referenced by
352	>	* any reader thread that may be in the midst of concurrently
353	>	* traversing table.  Upon transfer, the old table bin contains
354	>	* only a special forwarding node (with hash field "MOVED") that
355	>	* contains the next table as its key. On encountering a
356	>	* forwarding node, access and update operations restart, using
357	>	* the new table.
358	>	*
359	>	* Each bin transfer requires its bin lock, which can stall
360	>	* waiting for locks while resizing. However, because other
361	>	* threads can join in and help resize rather than contend for
362	>	* locks, average aggregate waits become shorter as resizing
363	>	* progresses.  The transfer operation must also ensure that all
364	>	* accessible bins in both the old and new table are usable by any
365	>	* traversal.  This is arranged by proceeding from the last bin
366	>	* (table.length - 1) up towards the first.  Upon seeing a
367	>	* forwarding node, traversals (see class Traverser) arrange to
368	>	* move to the new table without revisiting nodes.  However, to
369	>	* ensure that no intervening nodes are skipped, bin splitting can
370	>	* only begin after the associated reverse-forwarders are in
371	>	* place.
372	>	*
373	>	* The traversal scheme also applies to partial traversals of
374	>	* ranges of bins (via an alternate Traverser constructor)
375	>	* to support partitioned aggregate operations.  Also, read-only
376	>	* operations give up if ever forwarded to a null table, which
377	>	* provides support for shutdown-style clearing, which is also not
378	>	* currently implemented.
379	>	*
380	>	* Lazy table initialization minimizes footprint until first use,
381	>	* and also avoids resizings when the first operation is from a
382	>	* putAll, constructor with map argument, or deserialization.
383	>	* These cases attempt to override the initial capacity settings,
384	>	* but harmlessly fail to take effect in cases of races.
385	>	*
386	>	* The element count is maintained using a specialization of
387	>	* LongAdder. We need to incorporate a specialization rather than
388	>	* just use a LongAdder in order to access implicit
389	>	* contention-sensing that leads to creation of multiple
390	>	* Cells.  The counter mechanics avoid contention on
391	>	* updates but can encounter cache thrashing if read too
392	>	* frequently during concurrent access. To avoid reading so often,
393	>	* resizing under contention is attempted only upon adding to a
394	>	* bin already holding two or more nodes. Under uniform hash
395	>	* distributions, the probability of this occurring at threshold
396	>	* is around 13%, meaning that only about 1 in 8 puts check
397	>	* threshold (and after resizing, many fewer do so). The bulk
398	>	* putAll operation further reduces contention by only committing
399	>	* count updates upon these size checks.
400	>	*
401	>	* Maintaining API and serialization compatibility with previous
402	>	* versions of this class introduces several oddities. Mainly: We
403	>	* leave untouched but unused constructor arguments refering to
404	>	* concurrencyLevel. We accept a loadFactor constructor argument,
405	>	* but apply it only to initial table capacity (which is the only
406	>	* time that we can guarantee to honor it.) We also declare an
407	>	* unused "Segment" class that is instantiated in minimal form
408	>	* only when serializing.
409		*/
410
411		/* ---------------- Constants -------------- */
412
413		/**
414	<	* The default initial capacity for this table,
415	<	* used when not otherwise specified in a constructor.
414	>	* The largest possible table capacity.  This value must be
415	>	* exactly 1<<30 to stay within Java array allocation and indexing
416	>	* bounds for power of two table sizes, and is further required
417	>	* because the top two bits of 32bit hash fields are used for
418	>	* control purposes.
419		*/
420	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
420	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
421
422		/**
423	<	* The default load factor for this table, used when not
424	<	* otherwise specified in a constructor.
423	>	* The default initial table capacity.  Must be a power of 2
424	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
425		*/
426	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
426	>	private static final int DEFAULT_CAPACITY = 16;
427
428		/**
429	<	* The default concurrency level for this table, used when not
430	<	* otherwise specified in a constructor.
429	>	* The largest possible (non-power of two) array size.
430	>	* Needed by toArray and related methods.
431		*/
432	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
432	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
433
434		/**
435	<	* The maximum capacity, used if a higher value is implicitly
436	<	* specified by either of the constructors with arguments.  MUST
123	<	* be a power of two <= 1<<30 to ensure that entries are indexable
124	<	* using ints.
435	>	* The default concurrency level for this table. Unused but
436	>	* defined for compatibility with previous versions of this class.
437		*/
438	<	static final int MAXIMUM_CAPACITY = 1 << 30;
438	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
439
440		/**
441	<	* The minimum capacity for per-segment tables.  Must be a power
442	<	* of two, at least two to avoid immediate resizing on next use
443	<	* after lazy construction.
441	>	* The load factor for this table. Overrides of this value in
442	>	* constructors affect only the initial table capacity.  The
443	>	* actual floating point value isn't normally used -- it is
444	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
445	>	* the associated resizing threshold.
446		*/
447	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
447	>	private static final float LOAD_FACTOR = 0.75f;
448
449		/**
450	<	* The maximum number of segments to allow; used to bound
451	<	* constructor arguments. Must be power of two less than 1 << 24.
450	>	* The bin count threshold for using a tree rather than list for a
451	>	* bin.  The value reflects the approximate break-even point for
452	>	* using tree-based operations.
453		*/
454	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
454	>	private static final int TREE_THRESHOLD = 16;
455
456		/**
457	<	* Number of unsynchronized retries in size and containsValue
458	<	* methods before resorting to locking. This is used to avoid
459	<	* unbounded retries if tables undergo continuous modification
460	<	* which would make it impossible to obtain an accurate result.
457	>	* Minimum number of rebinnings per transfer step. Ranges are
458	>	* subdivided to allow multiple resizer threads.  This value
459	>	* serves as a lower bound to avoid resizers encountering
460	>	* excessive memory contention.  The value should be at least
461	>	* DEFAULT_CAPACITY.
462	>	*/
463	>	private static final int MIN_TRANSFER_STRIDE = 16;
464	>
465	>	/*
466	>	* Encodings for Node hash fields. See above for explanation.
467		*/
468	<	static final int RETRIES_BEFORE_LOCK = 2;
468	>	static final int MOVED     = 0x80000000; // hash field for forwarding nodes
469	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
470	>
471	>	/** Number of CPUS, to place bounds on some sizings */
472	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
473	>
474	>	/* ---------------- Counters -------------- */
475	>
476	>	// Adapted from LongAdder and Striped64.
477	>	// See their internal docs for explanation.
478	>
479	>	// A padded cell for distributing counts
480	>	static final class Cell {
481	>	volatile long p0, p1, p2, p3, p4, p5, p6;
482	>	volatile long value;
483	>	volatile long q0, q1, q2, q3, q4, q5, q6;
484	>	Cell(long x) { value = x; }
485	>	}
486
487		/* ---------------- Fields -------------- */
488
489		/**
490	<	* Mask value for indexing into segments. The upper bits of a
491	<	* key's hash code are used to choose the segment.
490	>	* The array of bins. Lazily initialized upon first insertion.
491	>	* Size is always a power of two. Accessed directly by iterators.
492		*/
493	<	final int segmentMask;
493	>	transient volatile Node<V>[] table;
494
495		/**
496	<	* Shift value for indexing within segments.
496	>	* The next table to use; non-null only while resizing.
497		*/
498	<	final int segmentShift;
498	>	private transient volatile Node<V>[] nextTable;
499
500		/**
501	<	* The segments, each of which is a specialized hash table.
501	>	* Base counter value, used mainly when there is no contention,
502	>	* but also as a fallback during table initialization
503	>	* races. Updated via CAS.
504		*/
505	<	final Segment<K,V>[] segments;
505	>	private transient volatile long baseCount;
506
507	<	transient Set<K> keySet;
508	<	transient Set<Map.Entry<K,V>> entrySet;
509	<	transient Collection<V> values;
507	>	/**
508	>	* Table initialization and resizing control.  When negative, the
509	>	* table is being initialized or resized: -1 for initialization,
510	>	* else -(1 + the number of active resizing threads).  Otherwise,
511	>	* when table is null, holds the initial table size to use upon
512	>	* creation, or 0 for default. After initialization, holds the
513	>	* next element count value upon which to resize the table.
514	>	*/
515	>	private transient volatile int sizeCtl;
516	>
517	>	/**
518	>	* The next table index (plus one) to split while resizing.
519	>	*/
520	>	private transient volatile int transferIndex;
521
522		/**
523	<	* ConcurrentHashMap list entry. Note that this is never exported
173	<	* out as a user-visible Map.Entry.
523	>	* The least available table index to split while resizing.
524		*/
525	<	static final class HashEntry<K,V> {
525	>	private transient volatile int transferOrigin;
526	>
527	>	/**
528	>	* Spinlock (locked via CAS) used when resizing and/or creating Cells.
529	>	*/
530	>	private transient volatile int cellsBusy;
531	>
532	>	/**
533	>	* Table of counter cells. When non-null, size is a power of 2.
534	>	*/
535	>	private transient volatile Cell[] counterCells;
536	>
537	>	// views
538	>	private transient KeySetView<K,V> keySet;
539	>	private transient ValuesView<K,V> values;
540	>	private transient EntrySetView<K,V> entrySet;
541	>
542	>	/** For serialization compatibility. Null unless serialized; see below */
543	>	private Segment<K,V>[] segments;
544	>
545	>	/* ---------------- Table element access -------------- */
546	>
547	>	/*
548	>	* Volatile access methods are used for table elements as well as
549	>	* elements of in-progress next table while resizing.  Uses are
550	>	* null checked by callers, and implicitly bounds-checked, relying
551	>	* on the invariants that tab arrays have non-zero size, and all
552	>	* indices are masked with (tab.length - 1) which is never
553	>	* negative and always less than length. Note that, to be correct
554	>	* wrt arbitrary concurrency errors by users, bounds checks must
555	>	* operate on local variables, which accounts for some odd-looking
556	>	* inline assignments below.
557	>	*/
558	>
559	>	@SuppressWarnings("unchecked") static final <V> Node<V> tabAt
560	>	(Node<V>[] tab, int i) { // used by Traverser
561	>	return (Node<V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
562	>	}
563	>
564	>	private static final <V> boolean casTabAt
565	>	(Node<V>[] tab, int i, Node<V> c, Node<V> v) {
566	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
567	>	}
568	>
569	>	private static final <V> void setTabAt
570	>	(Node<V>[] tab, int i, Node<V> v) {
571	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
572	>	}
573	>
574	>	/* ---------------- Nodes -------------- */
575	>
576	>	/**
577	>	* Key-value entry. Note that this is never exported out as a
578	>	* user-visible Map.Entry (see MapEntry below). Nodes with a hash
579	>	* field of MOVED are special, and do not contain user keys or
580	>	* values.  Otherwise, keys are never null, and null val fields
581	>	* indicate that a node is in the process of being deleted or
582	>	* created. For purposes of read-only access, a key may be read
583	>	* before a val, but can only be used after checking val to be
584	>	* non-null.
585	>	*/
586	>	static class Node<V> {
587		final int hash;
588	<	final K key;
589	<	volatile V value;
590	<	volatile HashEntry<K,V> next;
588	>	final Object key;
589	>	volatile V val;
590	>	volatile Node<V> next;
591
592	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
592	>	Node(int hash, Object key, V val, Node<V> next) {
593		this.hash = hash;
594		this.key = key;
595	<	this.value = value;
595	>	this.val = val;
596		this.next = next;
597		}
598	+	}
599
600	<	/**
601	<	* Sets next field with volatile write semantics.  (See above
602	<	* about use of putOrderedObject.)
603	<	*/
604	<	final void setNext(HashEntry<K,V> n) {
605	<	UNSAFE.putOrderedObject(this, nextOffset, n);
600	>	/* ---------------- TreeBins -------------- */
601	>
602	>	/**
603	>	* Nodes for use in TreeBins
604	>	*/
605	>	static final class TreeNode<V> extends Node<V> {
606	>	TreeNode<V> parent;  // red-black tree links
607	>	TreeNode<V> left;
608	>	TreeNode<V> right;
609	>	TreeNode<V> prev;    // needed to unlink next upon deletion
610	>	boolean red;
611	>
612	>	TreeNode(int hash, Object key, V val, Node<V> next, TreeNode<V> parent) {
613	>	super(hash, key, val, next);
614	>	this.parent = parent;
615		}
616	+	}
617
618	<	// Unsafe mechanics
619	<	static final sun.misc.Unsafe UNSAFE;
620	<	static final long nextOffset;
621	<	static {
622	<	try {
623	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
624	<	Class k = HashEntry.class;
625	<	nextOffset = UNSAFE.objectFieldOffset
626	<	(k.getDeclaredField("next"));
627	<	} catch (Exception e) {
628	<	throw new Error(e);
618	>
619	>	/**
620	>	* Returns a Class for the given object of the form "class C
621	>	* implements Comparable<C>", if one exists, else null.  See below
622	>	* for explanation.
623	>	*/
624	>	static Class<?> comparableClassFor(Object x) {
625	>	Class<?> c, s, cmpc; Type[] ts, as; Type t; ParameterizedType p;
626	>	if ((c = x.getClass()) == String.class) // bypass checks
627	>	return c;
628	>	if ((cmpc = Comparable.class).isAssignableFrom(c)) {
629	>	while (cmpc.isAssignableFrom(s = c.getSuperclass()))
630	>	c = s; // find topmost comparable class
631	>	if ((ts  = c.getGenericInterfaces()) != null) {
632	>	for (int i = 0; i < ts.length; ++i) {
633	>	if (((t = ts[i]) instanceof ParameterizedType) &&
634	>	((p = (ParameterizedType)t).getRawType() == cmpc) &&
635	>	(as = p.getActualTypeArguments()) != null &&
636	>	as.length == 1 && as[0] == c) // type arg is c
637	>	return c;
638	>	}
639		}
640		}
641	+	return null;
642		}
643
644		/**
645	<	* Gets the ith element of given table (if nonnull) with volatile
646	<	* read semantics. Note: This is manually integrated into a few
647	<	* performance-sensitive methods to reduce call overhead.
648	<	*/
649	<	@SuppressWarnings("unchecked")
650	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
651	<	return (tab == null) ? null :
652	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
653	<	(tab, ((long)i << TSHIFT) + TBASE);
654	<	}
655	<
656	<	/**
657	<	* Sets the ith element of given table, with volatile write
658	<	* semantics. (See above about use of putOrderedObject.)
659	<	*/
660	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
661	<	HashEntry<K,V> e) {
662	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
663	<	}
664	<
665	<	/**
666	<	* Applies a supplemental hash function to a given hashCode, which
667	<	* defends against poor quality hash functions.  This is critical
668	<	* because ConcurrentHashMap uses power-of-two length hash tables,
669	<	* that otherwise encounter collisions for hashCodes that do not
670	<	* differ in lower or upper bits.
671	<	*/
672	<	private static int hash(int h) {
673	<	// Spread bits to regularize both segment and index locations,
674	<	// using variant of single-word Wang/Jenkins hash.
675	<	h += (h <<  15) ^ 0xffffcd7d;
676	<	h ^= (h >>> 10);
677	<	h += (h <<   3);
678	<	h ^= (h >>>  6);
679	<	h += (h <<   2) + (h << 14);
680	<	return h ^ (h >>> 16);
681	<	}
682	<
683	<	/**
684	<	* Segments are specialized versions of hash tables.  This
685	<	* subclasses from ReentrantLock opportunistically, just to
686	<	* simplify some locking and avoid separate construction.
254	<	*/
255	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
256	<	/*
257	<	* Segments maintain a table of entry lists that are always
258	<	* kept in a consistent state, so can be read (via volatile
259	<	* reads of segments and tables) without locking.  This
260	<	* requires replicating nodes when necessary during table
261	<	* resizing, so the old lists can be traversed by readers
262	<	* still using old version of table.
263	<	*
264	<	* This class defines only mutative methods requiring locking.
265	<	* Except as noted, the methods of this class perform the
266	<	* per-segment versions of ConcurrentHashMap methods.  (Other
267	<	* methods are integrated directly into ConcurrentHashMap
268	<	* methods.) These mutative methods use a form of controlled
269	<	* spinning on contention via methods scanAndLock and
270	<	* scanAndLockForPut. These intersperse tryLocks with
271	<	* traversals to locate nodes.  The main benefit is to absorb
272	<	* cache misses (which are very common for hash tables) while
273	<	* obtaining locks so that traversal is faster once
274	<	* acquired. We do not actually use the found nodes since they
275	<	* must be re-acquired under lock anyway to ensure sequential
276	<	* consistency of updates (and in any case may be undetectably
277	<	* stale), but they will normally be much faster to re-locate.
278	<	* Also, scanAndLockForPut speculatively creates a fresh node
279	<	* to use in put if no node is found.
280	<	*/
281	<
645	>	* A specialized form of red-black tree for use in bins
646	>	* whose size exceeds a threshold.
647	>	*
648	>	* TreeBins use a special form of comparison for search and
649	>	* related operations (which is the main reason we cannot use
650	>	* existing collections such as TreeMaps). TreeBins contain
651	>	* Comparable elements, but may contain others, as well as
652	>	* elements that are Comparable but not necessarily Comparable<T>
653	>	* for the same T, so we cannot invoke compareTo among them. To
654	>	* handle this, the tree is ordered primarily by hash value, then
655	>	* by Comparable.compareTo order if applicable.  On lookup at a
656	>	* node, if elements are not comparable or compare as 0 then both
657	>	* left and right children may need to be searched in the case of
658	>	* tied hash values. (This corresponds to the full list search
659	>	* that would be necessary if all elements were non-Comparable and
660	>	* had tied hashes.)  The red-black balancing code is updated from
661	>	* pre-jdk-collections
662	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
663	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
664	>	* Algorithms" (CLR).
665	>	*
666	>	* TreeBins also maintain a separate locking discipline than
667	>	* regular bins. Because they are forwarded via special MOVED
668	>	* nodes at bin heads (which can never change once established),
669	>	* we cannot use those nodes as locks. Instead, TreeBin
670	>	* extends AbstractQueuedSynchronizer to support a simple form of
671	>	* read-write lock. For update operations and table validation,
672	>	* the exclusive form of lock behaves in the same way as bin-head
673	>	* locks. However, lookups use shared read-lock mechanics to allow
674	>	* multiple readers in the absence of writers.  Additionally,
675	>	* these lookups do not ever block: While the lock is not
676	>	* available, they proceed along the slow traversal path (via
677	>	* next-pointers) until the lock becomes available or the list is
678	>	* exhausted, whichever comes first. (These cases are not fast,
679	>	* but maximize aggregate expected throughput.)  The AQS mechanics
680	>	* for doing this are straightforward.  The lock state is held as
681	>	* AQS getState().  Read counts are negative; the write count (1)
682	>	* is positive.  There are no signalling preferences among readers
683	>	* and writers. Since we don't need to export full Lock API, we
684	>	* just override the minimal AQS methods and use them directly.
685	>	*/
686	>	static final class TreeBin<V> extends AbstractQueuedSynchronizer {
687		private static final long serialVersionUID = 2249069246763182397L;
688	+	transient TreeNode<V> root;  // root of tree
689	+	transient TreeNode<V> first; // head of next-pointer list
690
691	<	/**
692	<	* The maximum number of times to tryLock in a prescan before
693	<	* possibly blocking on acquire in preparation for a locked
694	<	* segment operation. On multiprocessors, using a bounded
695	<	* number of retries maintains cache acquired while locating
696	<	* nodes.
697	<	*/
698	<	static final int MAX_SCAN_RETRIES =
699	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
691	>	/* AQS overrides */
692	>	public final boolean isHeldExclusively() { return getState() > 0; }
693	>	public final boolean tryAcquire(int ignore) {
694	>	if (compareAndSetState(0, 1)) {
695	>	setExclusiveOwnerThread(Thread.currentThread());
696	>	return true;
697	>	}
698	>	return false;
699	>	}
700	>	public final boolean tryRelease(int ignore) {
701	>	setExclusiveOwnerThread(null);
702	>	setState(0);
703	>	return true;
704	>	}
705	>	public final int tryAcquireShared(int ignore) {
706	>	for (int c;;) {
707	>	if ((c = getState()) > 0)
708	>	return -1;
709	>	if (compareAndSetState(c, c -1))
710	>	return 1;
711	>	}
712	>	}
713	>	public final boolean tryReleaseShared(int ignore) {
714	>	int c;
715	>	do {} while (!compareAndSetState(c = getState(), c + 1));
716	>	return c == -1;
717	>	}
718	>
719	>	/** From CLR */
720	>	private void rotateLeft(TreeNode<V> p) {
721	>	if (p != null) {
722	>	TreeNode<V> r = p.right, pp, rl;
723	>	if ((rl = p.right = r.left) != null)
724	>	rl.parent = p;
725	>	if ((pp = r.parent = p.parent) == null)
726	>	root = r;
727	>	else if (pp.left == p)
728	>	pp.left = r;
729	>	else
730	>	pp.right = r;
731	>	r.left = p;
732	>	p.parent = r;
733	>	}
734	>	}
735	>
736	>	/** From CLR */
737	>	private void rotateRight(TreeNode<V> p) {
738	>	if (p != null) {
739	>	TreeNode<V> l = p.left, pp, lr;
740	>	if ((lr = p.left = l.right) != null)
741	>	lr.parent = p;
742	>	if ((pp = l.parent = p.parent) == null)
743	>	root = l;
744	>	else if (pp.right == p)
745	>	pp.right = l;
746	>	else
747	>	pp.left = l;
748	>	l.right = p;
749	>	p.parent = l;
750	>	}
751	>	}
752
753		/**
754	<	* The per-segment table. Elements are accessed via
755	<	* entryAt/setEntryAt providing volatile semantics.
754	>	* Returns the TreeNode (or null if not found) for the given
755	>	* key.  A front-end for recursive version.
756		*/
757	<	transient volatile HashEntry<K,V>[] table;
757	>	final TreeNode<V> getTreeNode(int h, Object k) {
758	>	return getTreeNode(h, k, root, comparableClassFor(k));
759	>	}
760
761		/**
762	<	* The number of elements. Accessed only either within locks
763	<	* or among other volatile reads that maintain visibility.
762	>	* Returns the TreeNode (or null if not found) for the given key
763	>	* starting at given root.
764		*/
765	<	transient int count;
765	>	@SuppressWarnings("unchecked") final TreeNode<V> getTreeNode
766	>	(int h, Object k, TreeNode<V> p, Class<?> cc) {
767	>	while (p != null) {
768	>	int dir, ph;  Object pk;
769	>	if ((ph = p.hash) != h)
770	>	dir = (h < ph) ? -1 : 1;
771	>	else if ((pk = p.key) == k || k.equals(pk))
772	>	return p;
773	>	else if (cc == null || comparableClassFor(pk) != cc ||
774	>	(dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
775	>	TreeNode<V> r, pl, pr; // check both sides
776	>	if ((pr = p.right) != null && h >= pr.hash &&
777	>	(r = getTreeNode(h, k, pr, cc)) != null)
778	>	return r;
779	>	else if ((pl = p.left) != null && h <= pl.hash)
780	>	dir = -1;
781	>	else // nothing there
782	>	break;
783	>	}
784	>	p = (dir > 0) ? p.right : p.left;
785	>	}
786	>	return null;
787	>	}
788
789		/**
790	<	* The total number of mutative operations in this segment.
791	<	* Even though this may overflows 32 bits, it provides
792	<	* sufficient accuracy for stability checks in CHM isEmpty()
310	<	* and size() methods.  Accessed only either within locks or
311	<	* among other volatile reads that maintain visibility.
790	>	* Wrapper for getTreeNode used by CHM.get. Tries to obtain
791	>	* read-lock to call getTreeNode, but during failure to get
792	>	* lock, searches along next links.
793		*/
794	<	transient int modCount;
794	>	final V getValue(int h, Object k) {
795	>	Node<V> r = null;
796	>	int c = getState(); // Must read lock state first
797	>	for (Node<V> e = first; e != null; e = e.next) {
798	>	if (c <= 0 && compareAndSetState(c, c - 1)) {
799	>	try {
800	>	r = getTreeNode(h, k, root, comparableClassFor(k));
801	>	} finally {
802	>	releaseShared(0);
803	>	}
804	>	break;
805	>	}
806	>	else if (e.hash == h && k.equals(e.key)) {
807	>	r = e;
808	>	break;
809	>	}
810	>	else
811	>	c = getState();
812	>	}
813	>	return r == null ? null : r.val;
814	>	}
815
816		/**
817	<	* The table is rehashed when its size exceeds this threshold.
818	<	* (The value of this field is always <tt>(int)(capacity *
318	<	* loadFactor)</tt>.)
817	>	* Finds or adds a node.
818	>	* @return null if added
819		*/
820	<	transient int threshold;
820	>	@SuppressWarnings("unchecked") final TreeNode<V> putTreeNode
821	>	(int h, Object k, V v) {
822	>	Class<?> cc = comparableClassFor(k);
823	>	TreeNode<V> pp = root, p = null;
824	>	int dir = 0;
825	>	while (pp != null) { // find existing node or leaf to insert at
826	>	int ph;  Object pk;
827	>	p = pp;
828	>	if ((ph = p.hash) != h)
829	>	dir = (h < ph) ? -1 : 1;
830	>	else if ((pk = p.key) == k || k.equals(pk))
831	>	return p;
832	>	else if (cc == null || comparableClassFor(pk) != cc ||
833	>	(dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
834	>	TreeNode<V> r, pr;
835	>	if ((pr = p.right) != null && h >= pr.hash &&
836	>	(r = getTreeNode(h, k, pr, cc)) != null)
837	>	return r;
838	>	else // continue left
839	>	dir = -1;
840	>	}
841	>	pp = (dir > 0) ? p.right : p.left;
842	>	}
843	>
844	>	TreeNode<V> f = first;
845	>	TreeNode<V> x = first = new TreeNode<V>(h, k, v, f, p);
846	>	if (p == null)
847	>	root = x;
848	>	else { // attach and rebalance; adapted from CLR
849	>	TreeNode<V> xp, xpp;
850	>	if (f != null)
851	>	f.prev = x;
852	>	if (dir <= 0)
853	>	p.left = x;
854	>	else
855	>	p.right = x;
856	>	x.red = true;
857	>	while (x != null && (xp = x.parent) != null && xp.red &&
858	>	(xpp = xp.parent) != null) {
859	>	TreeNode<V> xppl = xpp.left;
860	>	if (xp == xppl) {
861	>	TreeNode<V> y = xpp.right;
862	>	if (y != null && y.red) {
863	>	y.red = false;
864	>	xp.red = false;
865	>	xpp.red = true;
866	>	x = xpp;
867	>	}
868	>	else {
869	>	if (x == xp.right) {
870	>	rotateLeft(x = xp);
871	>	xpp = (xp = x.parent) == null ? null : xp.parent;
872	>	}
873	>	if (xp != null) {
874	>	xp.red = false;
875	>	if (xpp != null) {
876	>	xpp.red = true;
877	>	rotateRight(xpp);
878	>	}
879	>	}
880	>	}
881	>	}
882	>	else {
883	>	TreeNode<V> y = xppl;
884	>	if (y != null && y.red) {
885	>	y.red = false;
886	>	xp.red = false;
887	>	xpp.red = true;
888	>	x = xpp;
889	>	}
890	>	else {
891	>	if (x == xp.left) {
892	>	rotateRight(x = xp);
893	>	xpp = (xp = x.parent) == null ? null : xp.parent;
894	>	}
895	>	if (xp != null) {
896	>	xp.red = false;
897	>	if (xpp != null) {
898	>	xpp.red = true;
899	>	rotateLeft(xpp);
900	>	}
901	>	}
902	>	}
903	>	}
904	>	}
905	>	TreeNode<V> r = root;
906	>	if (r != null && r.red)
907	>	r.red = false;
908	>	}
909	>	return null;
910	>	}
911
912		/**
913	<	* The load factor for the hash table.  Even though this value
914	<	* is same for all segments, it is replicated to avoid needing
915	<	* links to outer object.
916	<	* @serial
913	>	* Removes the given node, that must be present before this
914	>	* call.  This is messier than typical red-black deletion code
915	>	* because we cannot swap the contents of an interior node
916	>	* with a leaf successor that is pinned by "next" pointers
917	>	* that are accessible independently of lock. So instead we
918	>	* swap the tree linkages.
919		*/
920	<	final float loadFactor;
920	>	final void deleteTreeNode(TreeNode<V> p) {
921	>	TreeNode<V> next = (TreeNode<V>)p.next; // unlink traversal pointers
922	>	TreeNode<V> pred = p.prev;
923	>	if (pred == null)
924	>	first = next;
925	>	else
926	>	pred.next = next;
927	>	if (next != null)
928	>	next.prev = pred;
929	>	TreeNode<V> replacement;
930	>	TreeNode<V> pl = p.left;
931	>	TreeNode<V> pr = p.right;
932	>	if (pl != null && pr != null) {
933	>	TreeNode<V> s = pr, sl;
934	>	while ((sl = s.left) != null) // find successor
935	>	s = sl;
936	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
937	>	TreeNode<V> sr = s.right;
938	>	TreeNode<V> pp = p.parent;
939	>	if (s == pr) { // p was s's direct parent
940	>	p.parent = s;
941	>	s.right = p;
942	>	}
943	>	else {
944	>	TreeNode<V> sp = s.parent;
945	>	if ((p.parent = sp) != null) {
946	>	if (s == sp.left)
947	>	sp.left = p;
948	>	else
949	>	sp.right = p;
950	>	}
951	>	if ((s.right = pr) != null)
952	>	pr.parent = s;
953	>	}
954	>	p.left = null;
955	>	if ((p.right = sr) != null)
956	>	sr.parent = p;
957	>	if ((s.left = pl) != null)
958	>	pl.parent = s;
959	>	if ((s.parent = pp) == null)
960	>	root = s;
961	>	else if (p == pp.left)
962	>	pp.left = s;
963	>	else
964	>	pp.right = s;
965	>	replacement = sr;
966	>	}
967	>	else
968	>	replacement = (pl != null) ? pl : pr;
969	>	TreeNode<V> pp = p.parent;
970	>	if (replacement == null) {
971	>	if (pp == null) {
972	>	root = null;
973	>	return;
974	>	}
975	>	replacement = p;
976	>	}
977	>	else {
978	>	replacement.parent = pp;
979	>	if (pp == null)
980	>	root = replacement;
981	>	else if (p == pp.left)
982	>	pp.left = replacement;
983	>	else
984	>	pp.right = replacement;
985	>	p.left = p.right = p.parent = null;
986	>	}
987	>	if (!p.red) { // rebalance, from CLR
988	>	TreeNode<V> x = replacement;
989	>	while (x != null) {
990	>	TreeNode<V> xp, xpl;
991	>	if (x.red || (xp = x.parent) == null) {
992	>	x.red = false;
993	>	break;
994	>	}
995	>	if (x == (xpl = xp.left)) {
996	>	TreeNode<V> sib = xp.right;
997	>	if (sib != null && sib.red) {
998	>	sib.red = false;
999	>	xp.red = true;
1000	>	rotateLeft(xp);
1001	>	sib = (xp = x.parent) == null ? null : xp.right;
1002	>	}
1003	>	if (sib == null)
1004	>	x = xp;
1005	>	else {
1006	>	TreeNode<V> sl = sib.left, sr = sib.right;
1007	>	if ((sr == null || !sr.red) &&
1008	>	(sl == null || !sl.red)) {
1009	>	sib.red = true;
1010	>	x = xp;
1011	>	}
1012	>	else {
1013	>	if (sr == null || !sr.red) {
1014	>	if (sl != null)
1015	>	sl.red = false;
1016	>	sib.red = true;
1017	>	rotateRight(sib);
1018	>	sib = (xp = x.parent) == null ?
1019	>	null : xp.right;
1020	>	}
1021	>	if (sib != null) {
1022	>	sib.red = (xp == null) ? false : xp.red;
1023	>	if ((sr = sib.right) != null)
1024	>	sr.red = false;
1025	>	}
1026	>	if (xp != null) {
1027	>	xp.red = false;
1028	>	rotateLeft(xp);
1029	>	}
1030	>	x = root;
1031	>	}
1032	>	}
1033	>	}
1034	>	else { // symmetric
1035	>	TreeNode<V> sib = xpl;
1036	>	if (sib != null && sib.red) {
1037	>	sib.red = false;
1038	>	xp.red = true;
1039	>	rotateRight(xp);
1040	>	sib = (xp = x.parent) == null ? null : xp.left;
1041	>	}
1042	>	if (sib == null)
1043	>	x = xp;
1044	>	else {
1045	>	TreeNode<V> sl = sib.left, sr = sib.right;
1046	>	if ((sl == null || !sl.red) &&
1047	>	(sr == null || !sr.red)) {
1048	>	sib.red = true;
1049	>	x = xp;
1050	>	}
1051	>	else {
1052	>	if (sl == null || !sl.red) {
1053	>	if (sr != null)
1054	>	sr.red = false;
1055	>	sib.red = true;
1056	>	rotateLeft(sib);
1057	>	sib = (xp = x.parent) == null ?
1058	>	null : xp.left;
1059	>	}
1060	>	if (sib != null) {
1061	>	sib.red = (xp == null) ? false : xp.red;
1062	>	if ((sl = sib.left) != null)
1063	>	sl.red = false;
1064	>	}
1065	>	if (xp != null) {
1066	>	xp.red = false;
1067	>	rotateRight(xp);
1068	>	}
1069	>	x = root;
1070	>	}
1071	>	}
1072	>	}
1073	>	}
1074	>	}
1075	>	if (p == replacement && (pp = p.parent) != null) {
1076	>	if (p == pp.left) // detach pointers
1077	>	pp.left = null;
1078	>	else if (p == pp.right)
1079	>	pp.right = null;
1080	>	p.parent = null;
1081	>	}
1082	>	}
1083	>	}
1084	>
1085	>	/* ---------------- Collision reduction methods -------------- */
1086	>
1087	>	/**
1088	>	* Spreads higher bits to lower, and also forces top bit to 0.
1089	>	* Because the table uses power-of-two masking, sets of hashes
1090	>	* that vary only in bits above the current mask will always
1091	>	* collide. (Among known examples are sets of Float keys holding
1092	>	* consecutive whole numbers in small tables.)  To counter this,
1093	>	* we apply a transform that spreads the impact of higher bits
1094	>	* downward. There is a tradeoff between speed, utility, and
1095	>	* quality of bit-spreading. Because many common sets of hashes
1096	>	* are already reasonably distributed across bits (so don't benefit
1097	>	* from spreading), and because we use trees to handle large sets
1098	>	* of collisions in bins, we don't need excessively high quality.
1099	>	*/
1100	>	private static final int spread(int h) {
1101	>	h ^= (h >>> 18) ^ (h >>> 12);
1102	>	return (h ^ (h >>> 10)) & HASH_BITS;
1103	>	}
1104
1105	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
1106	<	this.loadFactor = lf;
1107	<	this.threshold = threshold;
1108	<	this.table = tab;
1105	>	/**
1106	>	* Replaces a list bin with a tree bin if key is comparable.  Call
1107	>	* only when locked.
1108	>	*/
1109	>	private final void replaceWithTreeBin(Node<V>[] tab, int index, Object key) {
1110	>	if (comparableClassFor(key) != null) {
1111	>	TreeBin<V> t = new TreeBin<V>();
1112	>	for (Node<V> e = tabAt(tab, index); e != null; e = e.next)
1113	>	t.putTreeNode(e.hash, e.key, e.val);
1114	>	setTabAt(tab, index, new Node<V>(MOVED, t, null, null));
1115		}
1116	+	}
1117
1118	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
1119	<	HashEntry<K,V> node = tryLock() ? null :
1120	<	scanAndLockForPut(key, hash, value);
1121	<	V oldValue;
1122	<	try {
1123	<	HashEntry<K,V>[] tab = table;
1124	<	int index = (tab.length - 1) & hash;
1125	<	HashEntry<K,V> first = entryAt(tab, index);
1126	<	for (HashEntry<K,V> e = first;;) {
1127	<	if (e != null) {
1128	<	K k;
1129	<	if ((k = e.key) == key ||
1130	<	(e.hash == hash && key.equals(k))) {
1131	<	oldValue = e.value;
1132	<	if (!onlyIfAbsent) {
1133	<	e.value = value;
1134	<	++modCount;
1118	>	/* ---------------- Internal access and update methods -------------- */
1119	>
1120	>	/** Implementation for get and containsKey */
1121	>	@SuppressWarnings("unchecked") private final V internalGet(Object k) {
1122	>	int h = spread(k.hashCode());
1123	>	retry: for (Node<V>[] tab = table; tab != null;) {
1124	>	Node<V> e; Object ek; V ev; int eh; // locals to read fields once
1125	>	for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
1126	>	if ((eh = e.hash) < 0) {
1127	>	if ((ek = e.key) instanceof TreeBin)  // search TreeBin
1128	>	return ((TreeBin<V>)ek).getValue(h, k);
1129	>	else {                      // restart with new table
1130	>	tab = (Node<V>[])ek;
1131	>	continue retry;
1132	>	}
1133	>	}
1134	>	else if (eh == h && (ev = e.val) != null &&
1135	>	((ek = e.key) == k || k.equals(ek)))
1136	>	return ev;
1137	>	}
1138	>	break;
1139	>	}
1140	>	return null;
1141	>	}
1142	>
1143	>	/**
1144	>	* Implementation for the four public remove/replace methods:
1145	>	* Replaces node value with v, conditional upon match of cv if
1146	>	* non-null.  If resulting value is null, delete.
1147	>	*/
1148	>	@SuppressWarnings("unchecked") private final V internalReplace
1149	>	(Object k, V v, Object cv) {
1150	>	int h = spread(k.hashCode());
1151	>	V oldVal = null;
1152	>	for (Node<V>[] tab = table;;) {
1153	>	Node<V> f; int i, fh; Object fk;
1154	>	if (tab == null ||
1155	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1156	>	break;
1157	>	else if ((fh = f.hash) < 0) {
1158	>	if ((fk = f.key) instanceof TreeBin) {
1159	>	TreeBin<V> t = (TreeBin<V>)fk;
1160	>	boolean validated = false;
1161	>	boolean deleted = false;
1162	>	t.acquire(0);
1163	>	try {
1164	>	if (tabAt(tab, i) == f) {
1165	>	validated = true;
1166	>	TreeNode<V> p = t.getTreeNode(h, k);
1167	>	if (p != null) {
1168	>	V pv = p.val;
1169	>	if (cv == null || cv == pv || cv.equals(pv)) {
1170	>	oldVal = pv;
1171	>	if ((p.val = v) == null) {
1172	>	deleted = true;
1173	>	t.deleteTreeNode(p);
1174	>	}
1175	>	}
1176		}
354	–	break;
1177		}
1178	<	e = e.next;
1178	>	} finally {
1179	>	t.release(0);
1180		}
1181	<	else {
1182	<	if (node != null)
1183	<	node.setNext(first);
361	<	else
362	<	node = new HashEntry<K,V>(hash, key, value, first);
363	<	int c = count + 1;
364	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
365	<	rehash(node);
366	<	else
367	<	setEntryAt(tab, index, node);
368	<	++modCount;
369	<	count = c;
370	<	oldValue = null;
1181	>	if (validated) {
1182	>	if (deleted)
1183	>	addCount(-1L, -1);
1184		break;
1185		}
1186		}
1187	<	} finally {
1188	<	unlock();
1187	>	else
1188	>	tab = (Node<V>[])fk;
1189	>	}
1190	>	else if (fh != h && f.next == null) // precheck
1191	>	break;                          // rules out possible existence
1192	>	else {
1193	>	boolean validated = false;
1194	>	boolean deleted = false;
1195	>	synchronized (f) {
1196	>	if (tabAt(tab, i) == f) {
1197	>	validated = true;
1198	>	for (Node<V> e = f, pred = null;;) {
1199	>	Object ek; V ev;
1200	>	if (e.hash == h &&
1201	>	((ev = e.val) != null) &&
1202	>	((ek = e.key) == k || k.equals(ek))) {
1203	>	if (cv == null || cv == ev || cv.equals(ev)) {
1204	>	oldVal = ev;
1205	>	if ((e.val = v) == null) {
1206	>	deleted = true;
1207	>	Node<V> en = e.next;
1208	>	if (pred != null)
1209	>	pred.next = en;
1210	>	else
1211	>	setTabAt(tab, i, en);
1212	>	}
1213	>	}
1214	>	break;
1215	>	}
1216	>	pred = e;
1217	>	if ((e = e.next) == null)
1218	>	break;
1219	>	}
1220	>	}
1221	>	}
1222	>	if (validated) {
1223	>	if (deleted)
1224	>	addCount(-1L, -1);
1225	>	break;
1226	>	}
1227		}
377	–	return oldValue;
1228		}
1229	+	return oldVal;
1230	+	}
1231
1232	<	/**
1233	<	* Doubles size of table and repacks entries, also adding the
1234	<	* given node to new table
1235	<	*/
1236	<	@SuppressWarnings("unchecked")
1237	<	private void rehash(HashEntry<K,V> node) {
1238	<	/*
1239	<	* Reclassify nodes in each list to new table.  Because we
1240	<	* are using power-of-two expansion, the elements from
1241	<	* each bin must either stay at same index, or move with a
1242	<	* power of two offset. We eliminate unnecessary node
1243	<	* creation by catching cases where old nodes can be
1244	<	* reused because their next fields won't change.
1245	<	* Statistically, at the default threshold, only about
1246	<	* one-sixth of them need cloning when a table
1247	<	* doubles. The nodes they replace will be garbage
1248	<	* collectable as soon as they are no longer referenced by
1249	<	* any reader thread that may be in the midst of
1250	<	* concurrently traversing table. Entry accesses use plain
1251	<	* array indexing because they are followed by volatile
1252	<	* table write.
1253	<	*/
1254	<	HashEntry<K,V>[] oldTable = table;
1255	<	int oldCapacity = oldTable.length;
1256	<	int newCapacity = oldCapacity << 1;
1257	<	threshold = (int)(newCapacity * loadFactor);
1258	<	HashEntry<K,V>[] newTable =
1259	<	(HashEntry<K,V>[]) new HashEntry[newCapacity];
1260	<	int sizeMask = newCapacity - 1;
1261	<	for (int i = 0; i < oldCapacity ; i++) {
1262	<	HashEntry<K,V> e = oldTable[i];
1263	<	if (e != null) {
1264	<	HashEntry<K,V> next = e.next;
1265	<	int idx = e.hash & sizeMask;
1266	<	if (next == null)   //  Single node on list
1267	<	newTable[idx] = e;
1268	<	else { // Reuse consecutive sequence at same slot
1269	<	HashEntry<K,V> lastRun = e;
1270	<	int lastIdx = idx;
1271	<	for (HashEntry<K,V> last = next;
1272	<	last != null;
1273	<	last = last.next) {
1274	<	int k = last.hash & sizeMask;
1275	<	if (k != lastIdx) {
1276	<	lastIdx = k;
1277	<	lastRun = last;
1278	<	}
1279	<	}
1280	<	newTable[lastIdx] = lastRun;
1281	<	// Clone remaining nodes
1282	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
1283	<	V v = p.value;
1284	<	int h = p.hash;
1285	<	int k = h & sizeMask;
1286	<	HashEntry<K,V> n = newTable[k];
1287	<	newTable[k] = new HashEntry<K,V>(h, p.key, v, n);
1288	<	}
1289	<	}
1290	<	}
1291	<	}
1292	<	int nodeIndex = node.hash & sizeMask; // add the new node
1293	<	node.setNext(newTable[nodeIndex]);
1294	<	newTable[nodeIndex] = node;
1295	<	table = newTable;
1296	<	}
1297	<
1298	<	/**
1299	<	* Scans for a node containing given key while trying to
1300	<	* acquire lock, creating and returning one if not found. Upon
1301	<	* return, guarantees that lock is held. Unlike in most
1302	<	* methods, calls to method equals are not screened: Since
1303	<	* traversal speed doesn't matter, we might as well help warm
1304	<	* up the associated code and accesses as well.
1305	<	*
1306	<	* @return a new node if key not found, else null
1307	<	*/
1308	<	private HashEntry<K,V> scanAndLockForPut(K key, int hash, V value) {
1309	<	HashEntry<K,V> first = entryForHash(this, hash);
1310	<	HashEntry<K,V> e = first;
1311	<	HashEntry<K,V> node = null;
1312	<	int retries = -1; // negative while locating node
1313	<	while (!tryLock()) {
1314	<	HashEntry<K,V> f; // to recheck first below
1315	<	if (retries < 0) {
1316	<	if (e == null) {
465	<	if (node == null) // speculatively create node
466	<	node = new HashEntry<K,V>(hash, key, value, null);
467	<	retries = 0;
1232	>	/*
1233	>	* Internal versions of insertion methods
1234	>	* All have the same basic structure as the first (internalPut):
1235	>	*  1. If table uninitialized, create
1236	>	*  2. If bin empty, try to CAS new node
1237	>	*  3. If bin stale, use new table
1238	>	*  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1239	>	*  5. Lock and validate; if valid, scan and add or update
1240	>	*
1241	>	* The putAll method differs mainly in attempting to pre-allocate
1242	>	* enough table space, and also more lazily performs count updates
1243	>	* and checks.
1244	>	*
1245	>	* Most of the function-accepting methods can't be factored nicely
1246	>	* because they require different functional forms, so instead
1247	>	* sprawl out similar mechanics.
1248	>	*/
1249	>
1250	>	/** Implementation for put and putIfAbsent */
1251	>	@SuppressWarnings("unchecked") private final V internalPut
1252	>	(K k, V v, boolean onlyIfAbsent) {
1253	>	if (k == null || v == null) throw new NullPointerException();
1254	>	int h = spread(k.hashCode());
1255	>	int len = 0;
1256	>	for (Node<V>[] tab = table;;) {
1257	>	int i, fh; Node<V> f; Object fk; V fv;
1258	>	if (tab == null)
1259	>	tab = initTable();
1260	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1261	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null)))
1262	>	break;                   // no lock when adding to empty bin
1263	>	}
1264	>	else if ((fh = f.hash) < 0) {
1265	>	if ((fk = f.key) instanceof TreeBin) {
1266	>	TreeBin<V> t = (TreeBin<V>)fk;
1267	>	V oldVal = null;
1268	>	t.acquire(0);
1269	>	try {
1270	>	if (tabAt(tab, i) == f) {
1271	>	len = 2;
1272	>	TreeNode<V> p = t.putTreeNode(h, k, v);
1273	>	if (p != null) {
1274	>	oldVal = p.val;
1275	>	if (!onlyIfAbsent)
1276	>	p.val = v;
1277	>	}
1278	>	}
1279	>	} finally {
1280	>	t.release(0);
1281	>	}
1282	>	if (len != 0) {
1283	>	if (oldVal != null)
1284	>	return oldVal;
1285	>	break;
1286	>	}
1287	>	}
1288	>	else
1289	>	tab = (Node<V>[])fk;
1290	>	}
1291	>	else if (onlyIfAbsent && fh == h && (fv = f.val) != null &&
1292	>	((fk = f.key) == k || k.equals(fk))) // peek while nearby
1293	>	return fv;
1294	>	else {
1295	>	V oldVal = null;
1296	>	synchronized (f) {
1297	>	if (tabAt(tab, i) == f) {
1298	>	len = 1;
1299	>	for (Node<V> e = f;; ++len) {
1300	>	Object ek; V ev;
1301	>	if (e.hash == h &&
1302	>	(ev = e.val) != null &&
1303	>	((ek = e.key) == k || k.equals(ek))) {
1304	>	oldVal = ev;
1305	>	if (!onlyIfAbsent)
1306	>	e.val = v;
1307	>	break;
1308	>	}
1309	>	Node<V> last = e;
1310	>	if ((e = e.next) == null) {
1311	>	last.next = new Node<V>(h, k, v, null);
1312	>	if (len >= TREE_THRESHOLD)
1313	>	replaceWithTreeBin(tab, i, k);
1314	>	break;
1315	>	}
1316	>	}
1317		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
1318		}
1319	<	else if (++retries > MAX_SCAN_RETRIES) {
1320	<	lock();
1319	>	if (len != 0) {
1320	>	if (oldVal != null)
1321	>	return oldVal;
1322		break;
1323		}
1324	<	else if ((retries & 1) == 0 &&
479	<	(f = entryForHash(this, hash)) != first) {
480	<	e = first = f; // re-traverse if entry changed
481	<	retries = -1;
482	<	}
483	<	}
484	<	return node;
1324	>	}
1325		}
1326	+	addCount(1L, len);
1327	+	return null;
1328	+	}
1329
1330	<	/**
1331	<	* Scans for a node containing the given key while trying to
1332	<	* acquire lock for a remove or replace operation. Upon
1333	<	* return, guarantees that lock is held.  Note that we must
1334	<	* lock even if the key is not found, to ensure sequential
1335	<	* consistency of updates.
1336	<	*/
1337	<	private void scanAndLock(Object key, int hash) {
1338	<	// similar to but simpler than scanAndLockForPut
1339	<	HashEntry<K,V> first = entryForHash(this, hash);
1340	<	HashEntry<K,V> e = first;
1341	<	int retries = -1;
1342	<	while (!tryLock()) {
1343	<	HashEntry<K,V> f;
1344	<	if (retries < 0) {
1345	<	if (e == null || key.equals(e.key))
1346	<	retries = 0;
1347	<	else
1348	<	e = e.next;
1330	>	/** Implementation for computeIfAbsent */
1331	>	@SuppressWarnings("unchecked") private final V internalComputeIfAbsent
1332	>	(K k, Function<? super K, ? extends V> mf) {
1333	>	if (k == null || mf == null)
1334	>	throw new NullPointerException();
1335	>	int h = spread(k.hashCode());
1336	>	V val = null;
1337	>	int len = 0;
1338	>	for (Node<V>[] tab = table;;) {
1339	>	Node<V> f; int i; Object fk;
1340	>	if (tab == null)
1341	>	tab = initTable();
1342	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1343	>	Node<V> node = new Node<V>(h, k, null, null);
1344	>	synchronized (node) {
1345	>	if (casTabAt(tab, i, null, node)) {
1346	>	len = 1;
1347	>	try {
1348	>	if ((val = mf.apply(k)) != null)
1349	>	node.val = val;
1350	>	} finally {
1351	>	if (val == null)
1352	>	setTabAt(tab, i, null);
1353	>	}
1354	>	}
1355		}
1356	<	else if (++retries > MAX_SCAN_RETRIES) {
508	<	lock();
1356	>	if (len != 0)
1357		break;
1358	+	}
1359	+	else if (f.hash < 0) {
1360	+	if ((fk = f.key) instanceof TreeBin) {
1361	+	TreeBin<V> t = (TreeBin<V>)fk;
1362	+	boolean added = false;
1363	+	t.acquire(0);
1364	+	try {
1365	+	if (tabAt(tab, i) == f) {
1366	+	len = 1;
1367	+	TreeNode<V> p = t.getTreeNode(h, k);
1368	+	if (p != null)
1369	+	val = p.val;
1370	+	else if ((val = mf.apply(k)) != null) {
1371	+	added = true;
1372	+	len = 2;
1373	+	t.putTreeNode(h, k, val);
1374	+	}
1375	+	}
1376	+	} finally {
1377	+	t.release(0);
1378	+	}
1379	+	if (len != 0) {
1380	+	if (!added)
1381	+	return val;
1382	+	break;
1383	+	}
1384		}
1385	<	else if ((retries & 1) == 0 &&
1386	<	(f = entryForHash(this, hash)) != first) {
1387	<	e = first = f;
1388	<	retries = -1;
1385	>	else
1386	>	tab = (Node<V>[])fk;
1387	>	}
1388	>	else {
1389	>	for (Node<V> e = f; e != null; e = e.next) { // prescan
1390	>	Object ek; V ev;
1391	>	if (e.hash == h && (ev = e.val) != null &&
1392	>	((ek = e.key) == k || k.equals(ek)))
1393	>	return ev;
1394	>	}
1395	>	boolean added = false;
1396	>	synchronized (f) {
1397	>	if (tabAt(tab, i) == f) {
1398	>	len = 1;
1399	>	for (Node<V> e = f;; ++len) {
1400	>	Object ek; V ev;
1401	>	if (e.hash == h &&
1402	>	(ev = e.val) != null &&
1403	>	((ek = e.key) == k || k.equals(ek))) {
1404	>	val = ev;
1405	>	break;
1406	>	}
1407	>	Node<V> last = e;
1408	>	if ((e = e.next) == null) {
1409	>	if ((val = mf.apply(k)) != null) {
1410	>	added = true;
1411	>	last.next = new Node<V>(h, k, val, null);
1412	>	if (len >= TREE_THRESHOLD)
1413	>	replaceWithTreeBin(tab, i, k);
1414	>	}
1415	>	break;
1416	>	}
1417	>	}
1418	>	}
1419	>	}
1420	>	if (len != 0) {
1421	>	if (!added)
1422	>	return val;
1423	>	break;
1424		}
1425		}
1426		}
1427	+	if (val != null)
1428	+	addCount(1L, len);
1429	+	return val;
1430	+	}
1431
1432	<	/**
1433	<	* Remove; match on key only if value null, else match both.
1434	<	*/
1435	<	final V remove(Object key, int hash, Object value) {
1436	<	if (!tryLock())
1437	<	scanAndLock(key, hash);
1438	<	V oldValue = null;
1439	<	try {
1440	<	HashEntry<K,V>[] tab = table;
1441	<	int index = (tab.length - 1) & hash;
1442	<	HashEntry<K,V> e = entryAt(tab, index);
1443	<	HashEntry<K,V> pred = null;
1444	<	while (e != null) {
1445	<	K k;
1446	<	HashEntry<K,V> next = e.next;
1447	<	if ((k = e.key) == key ||
1448	<	(e.hash == hash && key.equals(k))) {
1449	<	V v = e.value;
1450	<	if (value == null || value == v || value.equals(v)) {
1451	<	if (pred == null)
1452	<	setEntryAt(tab, index, next);
1453	<	else
1454	<	pred.setNext(next);
1455	<	++modCount;
1456	<	--count;
1457	<	oldValue = v;
1432	>	/** Implementation for compute */
1433	>	@SuppressWarnings("unchecked") private final V internalCompute
1434	>	(K k, boolean onlyIfPresent,
1435	>	BiFunction<? super K, ? super V, ? extends V> mf) {
1436	>	if (k == null || mf == null)
1437	>	throw new NullPointerException();
1438	>	int h = spread(k.hashCode());
1439	>	V val = null;
1440	>	int delta = 0;
1441	>	int len = 0;
1442	>	for (Node<V>[] tab = table;;) {
1443	>	Node<V> f; int i, fh; Object fk;
1444	>	if (tab == null)
1445	>	tab = initTable();
1446	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1447	>	if (onlyIfPresent)
1448	>	break;
1449	>	Node<V> node = new Node<V>(h, k, null, null);
1450	>	synchronized (node) {
1451	>	if (casTabAt(tab, i, null, node)) {
1452	>	try {
1453	>	len = 1;
1454	>	if ((val = mf.apply(k, null)) != null) {
1455	>	node.val = val;
1456	>	delta = 1;
1457	>	}
1458	>	} finally {
1459	>	if (delta == 0)
1460	>	setTabAt(tab, i, null);
1461	>	}
1462	>	}
1463	>	}
1464	>	if (len != 0)
1465	>	break;
1466	>	}
1467	>	else if ((fh = f.hash) < 0) {
1468	>	if ((fk = f.key) instanceof TreeBin) {
1469	>	TreeBin<V> t = (TreeBin<V>)fk;
1470	>	t.acquire(0);
1471	>	try {
1472	>	if (tabAt(tab, i) == f) {
1473	>	len = 1;
1474	>	TreeNode<V> p = t.getTreeNode(h, k);
1475	>	if (p == null && onlyIfPresent)
1476	>	break;
1477	>	V pv = (p == null) ? null : p.val;
1478	>	if ((val = mf.apply(k, pv)) != null) {
1479	>	if (p != null)
1480	>	p.val = val;
1481	>	else {
1482	>	len = 2;
1483	>	delta = 1;
1484	>	t.putTreeNode(h, k, val);
1485	>	}
1486	>	}
1487	>	else if (p != null) {
1488	>	delta = -1;
1489	>	t.deleteTreeNode(p);
1490	>	}
1491		}
1492	+	} finally {
1493	+	t.release(0);
1494	+	}
1495	+	if (len != 0)
1496		break;
1497	+	}
1498	+	else
1499	+	tab = (Node<V>[])fk;
1500	+	}
1501	+	else {
1502	+	synchronized (f) {
1503	+	if (tabAt(tab, i) == f) {
1504	+	len = 1;
1505	+	for (Node<V> e = f, pred = null;; ++len) {
1506	+	Object ek; V ev;
1507	+	if (e.hash == h &&
1508	+	(ev = e.val) != null &&
1509	+	((ek = e.key) == k || k.equals(ek))) {
1510	+	val = mf.apply(k, ev);
1511	+	if (val != null)
1512	+	e.val = val;
1513	+	else {
1514	+	delta = -1;
1515	+	Node<V> en = e.next;
1516	+	if (pred != null)
1517	+	pred.next = en;
1518	+	else
1519	+	setTabAt(tab, i, en);
1520	+	}
1521	+	break;
1522	+	}
1523	+	pred = e;
1524	+	if ((e = e.next) == null) {
1525	+	if (!onlyIfPresent &&
1526	+	(val = mf.apply(k, null)) != null) {
1527	+	pred.next = new Node<V>(h, k, val, null);
1528	+	delta = 1;
1529	+	if (len >= TREE_THRESHOLD)
1530	+	replaceWithTreeBin(tab, i, k);
1531	+	}
1532	+	break;
1533	+	}
1534	+	}
1535		}
548	–	pred = e;
549	–	e = next;
1536		}
1537	<	} finally {
1538	<	unlock();
1537	>	if (len != 0)
1538	>	break;
1539		}
554	–	return oldValue;
1540		}
1541	+	if (delta != 0)
1542	+	addCount((long)delta, len);
1543	+	return val;
1544	+	}
1545
1546	<	final boolean replace(K key, int hash, V oldValue, V newValue) {
1547	<	if (!tryLock())
1548	<	scanAndLock(key, hash);
1549	<	boolean replaced = false;
1550	<	try {
1551	<	HashEntry<K,V> e;
1552	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1553	<	K k;
1554	<	if ((k = e.key) == key ||
1555	<	(e.hash == hash && key.equals(k))) {
1556	<	if (oldValue.equals(e.value)) {
1557	<	e.value = newValue;
1558	<	++modCount;
1559	<	replaced = true;
1546	>	/** Implementation for merge */
1547	>	@SuppressWarnings("unchecked") private final V internalMerge
1548	>	(K k, V v, BiFunction<? super V, ? super V, ? extends V> mf) {
1549	>	if (k == null || v == null || mf == null)
1550	>	throw new NullPointerException();
1551	>	int h = spread(k.hashCode());
1552	>	V val = null;
1553	>	int delta = 0;
1554	>	int len = 0;
1555	>	for (Node<V>[] tab = table;;) {
1556	>	int i; Node<V> f; Object fk; V fv;
1557	>	if (tab == null)
1558	>	tab = initTable();
1559	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1560	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1561	>	delta = 1;
1562	>	val = v;
1563	>	break;
1564	>	}
1565	>	}
1566	>	else if (f.hash < 0) {
1567	>	if ((fk = f.key) instanceof TreeBin) {
1568	>	TreeBin<V> t = (TreeBin<V>)fk;
1569	>	t.acquire(0);
1570	>	try {
1571	>	if (tabAt(tab, i) == f) {
1572	>	len = 1;
1573	>	TreeNode<V> p = t.getTreeNode(h, k);
1574	>	val = (p == null) ? v : mf.apply(p.val, v);
1575	>	if (val != null) {
1576	>	if (p != null)
1577	>	p.val = val;
1578	>	else {
1579	>	len = 2;
1580	>	delta = 1;
1581	>	t.putTreeNode(h, k, val);
1582	>	}
1583	>	}
1584	>	else if (p != null) {
1585	>	delta = -1;
1586	>	t.deleteTreeNode(p);
1587	>	}
1588		}
1589	+	} finally {
1590	+	t.release(0);
1591	+	}
1592	+	if (len != 0)
1593		break;
1594	+	}
1595	+	else
1596	+	tab = (Node<V>[])fk;
1597	+	}
1598	+	else {
1599	+	synchronized (f) {
1600	+	if (tabAt(tab, i) == f) {
1601	+	len = 1;
1602	+	for (Node<V> e = f, pred = null;; ++len) {
1603	+	Object ek; V ev;
1604	+	if (e.hash == h &&
1605	+	(ev = e.val) != null &&
1606	+	((ek = e.key) == k || k.equals(ek))) {
1607	+	val = mf.apply(ev, v);
1608	+	if (val != null)
1609	+	e.val = val;
1610	+	else {
1611	+	delta = -1;
1612	+	Node<V> en = e.next;
1613	+	if (pred != null)
1614	+	pred.next = en;
1615	+	else
1616	+	setTabAt(tab, i, en);
1617	+	}
1618	+	break;
1619	+	}
1620	+	pred = e;
1621	+	if ((e = e.next) == null) {
1622	+	val = v;
1623	+	pred.next = new Node<V>(h, k, val, null);
1624	+	delta = 1;
1625	+	if (len >= TREE_THRESHOLD)
1626	+	replaceWithTreeBin(tab, i, k);
1627	+	break;
1628	+	}
1629	+	}
1630		}
1631		}
1632	<	} finally {
1633	<	unlock();
1632	>	if (len != 0)
1633	>	break;
1634		}
578	–	return replaced;
1635		}
1636	<
1637	<	final V replace(K key, int hash, V value) {
1638	<	if (!tryLock())
1639	<	scanAndLock(key, hash);
1640	<	V oldValue = null;
1641	<	try {
1642	<	HashEntry<K,V> e;
1643	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1644	<	K k;
1645	<	if ((k = e.key) == key ||
1646	<	(e.hash == hash && key.equals(k))) {
1647	<	oldValue = e.value;
1648	<	e.value = value;
1649	<	++modCount;
1650	<	break;
1636	>	if (delta != 0)
1637	>	addCount((long)delta, len);
1638	>	return val;
1639	>	}
1640	>
1641	>	/** Implementation for putAll */
1642	>	@SuppressWarnings("unchecked") private final void internalPutAll
1643	>	(Map<? extends K, ? extends V> m) {
1644	>	tryPresize(m.size());
1645	>	long delta = 0L;     // number of uncommitted additions
1646	>	boolean npe = false; // to throw exception on exit for nulls
1647	>	try {                // to clean up counts on other exceptions
1648	>	for (Map.Entry<?, ? extends V> entry : m.entrySet()) {
1649	>	Object k; V v;
1650	>	if (entry == null || (k = entry.getKey()) == null ||
1651	>	(v = entry.getValue()) == null) {
1652	>	npe = true;
1653	>	break;
1654	>	}
1655	>	int h = spread(k.hashCode());
1656	>	for (Node<V>[] tab = table;;) {
1657	>	int i; Node<V> f; int fh; Object fk;
1658	>	if (tab == null)
1659	>	tab = initTable();
1660	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1661	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1662	>	++delta;
1663	>	break;
1664	>	}
1665	>	}
1666	>	else if ((fh = f.hash) < 0) {
1667	>	if ((fk = f.key) instanceof TreeBin) {
1668	>	TreeBin<V> t = (TreeBin<V>)fk;
1669	>	boolean validated = false;
1670	>	t.acquire(0);
1671	>	try {
1672	>	if (tabAt(tab, i) == f) {
1673	>	validated = true;
1674	>	TreeNode<V> p = t.getTreeNode(h, k);
1675	>	if (p != null)
1676	>	p.val = v;
1677	>	else {
1678	>	t.putTreeNode(h, k, v);
1679	>	++delta;
1680	>	}
1681	>	}
1682	>	} finally {
1683	>	t.release(0);
1684	>	}
1685	>	if (validated)
1686	>	break;
1687	>	}
1688	>	else
1689	>	tab = (Node<V>[])fk;
1690	>	}
1691	>	else {
1692	>	int len = 0;
1693	>	synchronized (f) {
1694	>	if (tabAt(tab, i) == f) {
1695	>	len = 1;
1696	>	for (Node<V> e = f;; ++len) {
1697	>	Object ek; V ev;
1698	>	if (e.hash == h &&
1699	>	(ev = e.val) != null &&
1700	>	((ek = e.key) == k || k.equals(ek))) {
1701	>	e.val = v;
1702	>	break;
1703	>	}
1704	>	Node<V> last = e;
1705	>	if ((e = e.next) == null) {
1706	>	++delta;
1707	>	last.next = new Node<V>(h, k, v, null);
1708	>	if (len >= TREE_THRESHOLD)
1709	>	replaceWithTreeBin(tab, i, k);
1710	>	break;
1711	>	}
1712	>	}
1713	>	}
1714	>	}
1715	>	if (len != 0) {
1716	>	if (len > 1) {
1717	>	addCount(delta, len);
1718	>	delta = 0L;
1719	>	}
1720	>	break;
1721	>	}
1722		}
1723		}
597	–	} finally {
598	–	unlock();
1724		}
1725	<	return oldValue;
1725	>	} finally {
1726	>	if (delta != 0L)
1727	>	addCount(delta, 2);
1728		}
1729	+	if (npe)
1730	+	throw new NullPointerException();
1731	+	}
1732
1733	<	final void clear() {
1734	<	lock();
1735	<	try {
1736	<	HashEntry<K,V>[] tab = table;
1737	<	for (int i = 0; i < tab.length ; i++)
1738	<	setEntryAt(tab, i, null);
1739	<	++modCount;
1740	<	count = 0;
1741	<	} finally {
1742	<	unlock();
1733	>	/**
1734	>	* Implementation for clear. Steps through each bin, removing all
1735	>	* nodes.
1736	>	*/
1737	>	@SuppressWarnings("unchecked") private final void internalClear() {
1738	>	long delta = 0L; // negative number of deletions
1739	>	int i = 0;
1740	>	Node<V>[] tab = table;
1741	>	while (tab != null && i < tab.length) {
1742	>	Node<V> f = tabAt(tab, i);
1743	>	if (f == null)
1744	>	++i;
1745	>	else if (f.hash < 0) {
1746	>	Object fk;
1747	>	if ((fk = f.key) instanceof TreeBin) {
1748	>	TreeBin<V> t = (TreeBin<V>)fk;
1749	>	t.acquire(0);
1750	>	try {
1751	>	if (tabAt(tab, i) == f) {
1752	>	for (Node<V> p = t.first; p != null; p = p.next) {
1753	>	if (p.val != null) { // (currently always true)
1754	>	p.val = null;
1755	>	--delta;
1756	>	}
1757	>	}
1758	>	t.first = null;
1759	>	t.root = null;
1760	>	++i;
1761	>	}
1762	>	} finally {
1763	>	t.release(0);
1764	>	}
1765	>	}
1766	>	else
1767	>	tab = (Node<V>[])fk;
1768	>	}
1769	>	else {
1770	>	synchronized (f) {
1771	>	if (tabAt(tab, i) == f) {
1772	>	for (Node<V> e = f; e != null; e = e.next) {
1773	>	if (e.val != null) {  // (currently always true)
1774	>	e.val = null;
1775	>	--delta;
1776	>	}
1777	>	}
1778	>	setTabAt(tab, i, null);
1779	>	++i;
1780	>	}
1781	>	}
1782		}
1783		}
1784	+	if (delta != 0L)
1785	+	addCount(delta, -1);
1786		}
1787
1788	<	// Accessing segments
1788	>	/* ---------------- Table Initialization and Resizing -------------- */
1789
1790		/**
1791	<	* Gets the jth element of given segment array (if nonnull) with
1792	<	* volatile element access semantics via Unsafe. (The null check
622	<	* can trigger harmlessly only during deserialization.) Note:
623	<	* because each element of segments array is set only once (using
624	<	* fully ordered writes), some performance-sensitive methods rely
625	<	* on this method only as a recheck upon null reads.
1791	>	* Returns a power of two table size for the given desired capacity.
1792	>	* See Hackers Delight, sec 3.2
1793		*/
1794	<	@SuppressWarnings("unchecked")
1795	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1796	<	long u = (j << SSHIFT) + SBASE;
1797	<	return ss == null ? null :
1798	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1794	>	private static final int tableSizeFor(int c) {
1795	>	int n = c - 1;
1796	>	n |= n >>> 1;
1797	>	n |= n >>> 2;
1798	>	n |= n >>> 4;
1799	>	n |= n >>> 8;
1800	>	n |= n >>> 16;
1801	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1802	>	}
1803	>
1804	>	/**
1805	>	* Initializes table, using the size recorded in sizeCtl.
1806	>	*/
1807	>	@SuppressWarnings("unchecked") private final Node<V>[] initTable() {
1808	>	Node<V>[] tab; int sc;
1809	>	while ((tab = table) == null) {
1810	>	if ((sc = sizeCtl) < 0)
1811	>	Thread.yield(); // lost initialization race; just spin
1812	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1813	>	try {
1814	>	if ((tab = table) == null) {
1815	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1816	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1817	>	table = tab = (Node<V>[])tb;
1818	>	sc = n - (n >>> 2);
1819	>	}
1820	>	} finally {
1821	>	sizeCtl = sc;
1822	>	}
1823	>	break;
1824	>	}
1825	>	}
1826	>	return tab;
1827		}
1828
1829		/**
1830	<	* Returns the segment for the given index, creating it and
1831	<	* recording in segment table (via CAS) if not already present.
1830	>	* Adds to count, and if table is too small and not already
1831	>	* resizing, initiates transfer. If already resizing, helps
1832	>	* perform transfer if work is available.  Rechecks occupancy
1833	>	* after a transfer to see if another resize is already needed
1834	>	* because resizings are lagging additions.
1835		*
1836	<	* @param k the index
1837	<	* @return the segment
1836	>	* @param x the count to add
1837	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
1838		*/
1839	<	@SuppressWarnings("unchecked")
1840	<	private Segment<K,V> ensureSegment(int k) {
1841	<	final Segment<K,V>[] ss = this.segments;
1842	<	long u = (k << SSHIFT) + SBASE; // raw offset
1843	<	Segment<K,V> seg;
1844	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1845	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1846	<	int cap = proto.table.length;
1847	<	float lf = proto.loadFactor;
1848	<	int threshold = (int)(cap * lf);
1849	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry[cap];
1850	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1851	<	== null) { // recheck
1852	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1853	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1854	<	== null) {
1855	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1839	>	private final void addCount(long x, int check) {
1840	>	Cell[] as; long b, s;
1841	>	if ((as = counterCells) != null ||
1842	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1843	>	Cell a; long v; int m;
1844	>	boolean uncontended = true;
1845	>	if (as == null || (m = as.length - 1) < 0 ||
1846	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
1847	>	!(uncontended =
1848	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1849	>	fullAddCount(x, uncontended);
1850	>	return;
1851	>	}
1852	>	if (check <= 1)
1853	>	return;
1854	>	s = sumCount();
1855	>	}
1856	>	if (check >= 0) {
1857	>	Node<V>[] tab, nt; int sc;
1858	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1859	>	tab.length < MAXIMUM_CAPACITY) {
1860	>	if (sc < 0) {
1861	>	if (sc == -1 || transferIndex <= transferOrigin ||
1862	>	(nt = nextTable) == null)
1863		break;
1864	+	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1865	+	transfer(tab, nt);
1866		}
1867	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1868	+	transfer(tab, null);
1869	+	s = sumCount();
1870		}
1871		}
662	–	return seg;
1872		}
1873
665	–	// Hash-based segment and entry accesses
666	–
1874		/**
1875	<	* Gets the segment for the given hash code.
1875	>	* Tries to presize table to accommodate the given number of elements.
1876	>	*
1877	>	* @param size number of elements (doesn't need to be perfectly accurate)
1878		*/
1879	<	@SuppressWarnings("unchecked")
1880	<	private Segment<K,V> segmentForHash(int h) {
1881	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1882	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1879	>	@SuppressWarnings("unchecked") private final void tryPresize(int size) {
1880	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1881	>	tableSizeFor(size + (size >>> 1) + 1);
1882	>	int sc;
1883	>	while ((sc = sizeCtl) >= 0) {
1884	>	Node<V>[] tab = table; int n;
1885	>	if (tab == null || (n = tab.length) == 0) {
1886	>	n = (sc > c) ? sc : c;
1887	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1888	>	try {
1889	>	if (table == tab) {
1890	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1891	>	table = (Node<V>[])tb;
1892	>	sc = n - (n >>> 2);
1893	>	}
1894	>	} finally {
1895	>	sizeCtl = sc;
1896	>	}
1897	>	}
1898	>	}
1899	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1900	>	break;
1901	>	else if (tab == table &&
1902	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
1903	>	transfer(tab, null);
1904	>	}
1905		}
1906
1907		/**
1908	<	* Gets the table entry for the given segment and hash code.
1908	>	* Moves and/or copies the nodes in each bin to new table. See
1909	>	* above for explanation.
1910		*/
1911	<	@SuppressWarnings("unchecked")
1912	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1913	<	HashEntry<K,V>[] tab;
1914	<	return (seg == null || (tab = seg.table) == null) ? null :
1915	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
1916	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1911	>	@SuppressWarnings("unchecked") private final void transfer
1912	>	(Node<V>[] tab, Node<V>[] nextTab) {
1913	>	int n = tab.length, stride;
1914	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1915	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
1916	>	if (nextTab == null) {            // initiating
1917	>	try {
1918	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1];
1919	>	nextTab = (Node<V>[])tb;
1920	>	} catch (Throwable ex) {      // try to cope with OOME
1921	>	sizeCtl = Integer.MAX_VALUE;
1922	>	return;
1923	>	}
1924	>	nextTable = nextTab;
1925	>	transferOrigin = n;
1926	>	transferIndex = n;
1927	>	Node<V> rev = new Node<V>(MOVED, tab, null, null);
1928	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
1929	>	int nextk = (k > stride) ? k - stride : 0;
1930	>	for (int m = nextk; m < k; ++m)
1931	>	nextTab[m] = rev;
1932	>	for (int m = n + nextk; m < n + k; ++m)
1933	>	nextTab[m] = rev;
1934	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
1935	>	}
1936	>	}
1937	>	int nextn = nextTab.length;
1938	>	Node<V> fwd = new Node<V>(MOVED, nextTab, null, null);
1939	>	boolean advance = true;
1940	>	for (int i = 0, bound = 0;;) {
1941	>	int nextIndex, nextBound; Node<V> f; Object fk;
1942	>	while (advance) {
1943	>	if (--i >= bound)
1944	>	advance = false;
1945	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
1946	>	i = -1;
1947	>	advance = false;
1948	>	}
1949	>	else if (U.compareAndSwapInt
1950	>	(this, TRANSFERINDEX, nextIndex,
1951	>	nextBound = (nextIndex > stride ?
1952	>	nextIndex - stride : 0))) {
1953	>	bound = nextBound;
1954	>	i = nextIndex - 1;
1955	>	advance = false;
1956	>	}
1957	>	}
1958	>	if (i < 0 || i >= n || i + n >= nextn) {
1959	>	for (int sc;;) {
1960	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
1961	>	if (sc == -1) {
1962	>	nextTable = null;
1963	>	table = nextTab;
1964	>	sizeCtl = (n << 1) - (n >>> 1);
1965	>	}
1966	>	return;
1967	>	}
1968	>	}
1969	>	}
1970	>	else if ((f = tabAt(tab, i)) == null) {
1971	>	if (casTabAt(tab, i, null, fwd)) {
1972	>	setTabAt(nextTab, i, null);
1973	>	setTabAt(nextTab, i + n, null);
1974	>	advance = true;
1975	>	}
1976	>	}
1977	>	else if (f.hash >= 0) {
1978	>	synchronized (f) {
1979	>	if (tabAt(tab, i) == f) {
1980	>	int runBit = f.hash & n;
1981	>	Node<V> lastRun = f, lo = null, hi = null;
1982	>	for (Node<V> p = f.next; p != null; p = p.next) {
1983	>	int b = p.hash & n;
1984	>	if (b != runBit) {
1985	>	runBit = b;
1986	>	lastRun = p;
1987	>	}
1988	>	}
1989	>	if (runBit == 0)
1990	>	lo = lastRun;
1991	>	else
1992	>	hi = lastRun;
1993	>	for (Node<V> p = f; p != lastRun; p = p.next) {
1994	>	int ph = p.hash;
1995	>	Object pk = p.key; V pv = p.val;
1996	>	if ((ph & n) == 0)
1997	>	lo = new Node<V>(ph, pk, pv, lo);
1998	>	else
1999	>	hi = new Node<V>(ph, pk, pv, hi);
2000	>	}
2001	>	setTabAt(nextTab, i, lo);
2002	>	setTabAt(nextTab, i + n, hi);
2003	>	setTabAt(tab, i, fwd);
2004	>	advance = true;
2005	>	}
2006	>	}
2007	>	}
2008	>	else if ((fk = f.key) instanceof TreeBin) {
2009	>	TreeBin<V> t = (TreeBin<V>)fk;
2010	>	t.acquire(0);
2011	>	try {
2012	>	if (tabAt(tab, i) == f) {
2013	>	TreeBin<V> lt = new TreeBin<V>();
2014	>	TreeBin<V> ht = new TreeBin<V>();
2015	>	int lc = 0, hc = 0;
2016	>	for (Node<V> e = t.first; e != null; e = e.next) {
2017	>	int h = e.hash;
2018	>	Object k = e.key; V v = e.val;
2019	>	if ((h & n) == 0) {
2020	>	++lc;
2021	>	lt.putTreeNode(h, k, v);
2022	>	}
2023	>	else {
2024	>	++hc;
2025	>	ht.putTreeNode(h, k, v);
2026	>	}
2027	>	}
2028	>	Node<V> ln, hn; // throw away trees if too small
2029	>	if (lc < TREE_THRESHOLD) {
2030	>	ln = null;
2031	>	for (Node<V> p = lt.first; p != null; p = p.next)
2032	>	ln = new Node<V>(p.hash, p.key, p.val, ln);
2033	>	}
2034	>	else
2035	>	ln = new Node<V>(MOVED, lt, null, null);
2036	>	setTabAt(nextTab, i, ln);
2037	>	if (hc < TREE_THRESHOLD) {
2038	>	hn = null;
2039	>	for (Node<V> p = ht.first; p != null; p = p.next)
2040	>	hn = new Node<V>(p.hash, p.key, p.val, hn);
2041	>	}
2042	>	else
2043	>	hn = new Node<V>(MOVED, ht, null, null);
2044	>	setTabAt(nextTab, i + n, hn);
2045	>	setTabAt(tab, i, fwd);
2046	>	advance = true;
2047	>	}
2048	>	} finally {
2049	>	t.release(0);
2050	>	}
2051	>	}
2052	>	else
2053	>	advance = true; // already processed
2054	>	}
2055		}
2056
2057	<	/* ---------------- Public operations -------------- */
2057	>	/* ---------------- Counter support -------------- */
2058	>
2059	>	final long sumCount() {
2060	>	Cell[] as = counterCells; Cell a;
2061	>	long sum = baseCount;
2062	>	if (as != null) {
2063	>	for (int i = 0; i < as.length; ++i) {
2064	>	if ((a = as[i]) != null)
2065	>	sum += a.value;
2066	>	}
2067	>	}
2068	>	return sum;
2069	>	}
2070	>
2071	>	// See LongAdder version for explanation
2072	>	private final void fullAddCount(long x, boolean wasUncontended) {
2073	>	int h;
2074	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2075	>	ThreadLocalRandom.localInit();      // force initialization
2076	>	h = ThreadLocalRandom.getProbe();
2077	>	wasUncontended = true;
2078	>	}
2079	>	boolean collide = false;                // True if last slot nonempty
2080	>	for (;;) {
2081	>	Cell[] as; Cell a; int n; long v;
2082	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2083	>	if ((a = as[(n - 1) & h]) == null) {
2084	>	if (cellsBusy == 0) {            // Try to attach new Cell
2085	>	Cell r = new Cell(x); // Optimistic create
2086	>	if (cellsBusy == 0 &&
2087	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2088	>	boolean created = false;
2089	>	try {               // Recheck under lock
2090	>	Cell[] rs; int m, j;
2091	>	if ((rs = counterCells) != null &&
2092	>	(m = rs.length) > 0 &&
2093	>	rs[j = (m - 1) & h] == null) {
2094	>	rs[j] = r;
2095	>	created = true;
2096	>	}
2097	>	} finally {
2098	>	cellsBusy = 0;
2099	>	}
2100	>	if (created)
2101	>	break;
2102	>	continue;           // Slot is now non-empty
2103	>	}
2104	>	}
2105	>	collide = false;
2106	>	}
2107	>	else if (!wasUncontended)       // CAS already known to fail
2108	>	wasUncontended = true;      // Continue after rehash
2109	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2110	>	break;
2111	>	else if (counterCells != as || n >= NCPU)
2112	>	collide = false;            // At max size or stale
2113	>	else if (!collide)
2114	>	collide = true;
2115	>	else if (cellsBusy == 0 &&
2116	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2117	>	try {
2118	>	if (counterCells == as) {// Expand table unless stale
2119	>	Cell[] rs = new Cell[n << 1];
2120	>	for (int i = 0; i < n; ++i)
2121	>	rs[i] = as[i];
2122	>	counterCells = rs;
2123	>	}
2124	>	} finally {
2125	>	cellsBusy = 0;
2126	>	}
2127	>	collide = false;
2128	>	continue;                   // Retry with expanded table
2129	>	}
2130	>	h = ThreadLocalRandom.advanceProbe(h);
2131	>	}
2132	>	else if (cellsBusy == 0 && counterCells == as &&
2133	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2134	>	boolean init = false;
2135	>	try {                           // Initialize table
2136	>	if (counterCells == as) {
2137	>	Cell[] rs = new Cell[2];
2138	>	rs[h & 1] = new Cell(x);
2139	>	counterCells = rs;
2140	>	init = true;
2141	>	}
2142	>	} finally {
2143	>	cellsBusy = 0;
2144	>	}
2145	>	if (init)
2146	>	break;
2147	>	}
2148	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2149	>	break;                          // Fall back on using base
2150	>	}
2151	>	}
2152	>
2153	>	/* ----------------Table Traversal -------------- */
2154
2155		/**
2156	<	* Creates a new, empty map with the specified initial
2157	<	* capacity, load factor and concurrency level.
2156	>	* Encapsulates traversal for methods such as containsValue; also
2157	>	* serves as a base class for other iterators and bulk tasks.
2158		*
2159	<	* @param initialCapacity the initial capacity. The implementation
2160	<	* performs internal sizing to accommodate this many elements.
2161	<	* @param loadFactor  the load factor threshold, used to control resizing.
2162	<	* Resizing may be performed when the average number of elements per
2163	<	* bin exceeds this threshold.
2164	<	* @param concurrencyLevel the estimated number of concurrently
2165	<	* updating threads. The implementation performs internal sizing
2166	<	* to try to accommodate this many threads.
2167	<	* @throws IllegalArgumentException if the initial capacity is
2168	<	* negative or the load factor or concurrencyLevel are
2169	<	* nonpositive.
2159	>	* At each step, the iterator snapshots the key ("nextKey") and
2160	>	* value ("nextVal") of a valid node (i.e., one that, at point of
2161	>	* snapshot, has a non-null user value). Because val fields can
2162	>	* change (including to null, indicating deletion), field nextVal
2163	>	* might not be accurate at point of use, but still maintains the
2164	>	* weak consistency property of holding a value that was once
2165	>	* valid. To support iterator.remove, the nextKey field is not
2166	>	* updated (nulled out) when the iterator cannot advance.
2167	>	*
2168	>	* Exported iterators must track whether the iterator has advanced
2169	>	* (in hasNext vs next) (by setting/checking/nulling field
2170	>	* nextVal), and then extract key, value, or key-value pairs as
2171	>	* return values of next().
2172	>	*
2173	>	* Method advance visits once each still-valid node that was
2174	>	* reachable upon iterator construction. It might miss some that
2175	>	* were added to a bin after the bin was visited, which is OK wrt
2176	>	* consistency guarantees. Maintaining this property in the face
2177	>	* of possible ongoing resizes requires a fair amount of
2178	>	* bookkeeping state that is difficult to optimize away amidst
2179	>	* volatile accesses.  Even so, traversal maintains reasonable
2180	>	* throughput.
2181	>	*
2182	>	* Normally, iteration proceeds bin-by-bin traversing lists.
2183	>	* However, if the table has been resized, then all future steps
2184	>	* must traverse both the bin at the current index as well as at
2185	>	* (index + baseSize); and so on for further resizings. To
2186	>	* paranoically cope with potential sharing by users of iterators
2187	>	* across threads, iteration terminates if a bounds checks fails
2188	>	* for a table read.
2189	>	*
2190	>	* Methods advanceKey and advanceValue are specializations of the
2191	>	* common cases of advance, relaying to the full version
2192	>	* otherwise. The forEachKey and forEachValue methods further
2193	>	* specialize, bypassing all incremental field updates in most cases.
2194	>	*
2195	>	* This class supports both Spliterator-based traversal and
2196	>	* CountedCompleter-based bulk tasks. The same "batch" field is
2197	>	* used, but in slightly different ways, in the two cases.  For
2198	>	* Spliterators, it is a saturating (at Integer.MAX_VALUE)
2199	>	* estimate of element coverage. For CHM tasks, it is a pre-scaled
2200	>	* size that halves down to zero for leaf tasks, that is only
2201	>	* computed upon execution of the task. (Tasks can be submitted to
2202	>	* any pool, of any size, so we don't know scale factors until
2203	>	* running.)
2204	>	*
2205	>	* This class extends CountedCompleter to streamline parallel
2206	>	* iteration in bulk operations. This adds only a few fields of
2207	>	* space overhead, which is small enough in cases where it is not
2208	>	* needed to not worry about it.  Because CountedCompleter is
2209	>	* Serializable, but iterators need not be, we need to add warning
2210	>	* suppressions.
2211	>	*/
2212	>	@SuppressWarnings("serial") static class Traverser<K,V,R>
2213	>	extends CountedCompleter<R> {
2214	>	final ConcurrentHashMap<K,V> map;
2215	>	Node<V> next;        // the next entry to use
2216	>	K nextKey;           // cached key field of next
2217	>	V nextVal;           // cached val field of next
2218	>	Node<V>[] tab;       // current table; updated if resized
2219	>	int index;           // index of bin to use next
2220	>	int baseIndex;       // current index of initial table
2221	>	int baseLimit;       // index bound for initial table
2222	>	final int baseSize;  // initial table size
2223	>	int batch;           // split control
2224	>
2225	>	/** Creates iterator for all entries in the table. */
2226	>	Traverser(ConcurrentHashMap<K,V> map) {
2227	>	this.map = map;
2228	>	Node<V>[] t = this.tab = map.table;
2229	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2230	>	}
2231	>
2232	>	/** Task constructor */
2233	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it, int batch) {
2234	>	super(it);
2235	>	this.map = map;
2236	>	this.batch = batch; // -1 if unknown
2237	>	if (it == null) {
2238	>	Node<V>[] t = this.tab = map.table;
2239	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2240	>	}
2241	>	else { // split parent
2242	>	this.tab = it.tab;
2243	>	this.baseSize = it.baseSize;
2244	>	int hi = this.baseLimit = it.baseLimit;
2245	>	it.baseLimit = this.index = this.baseIndex =
2246	>	(hi + it.baseIndex) >>> 1;
2247	>	}
2248	>	}
2249	>
2250	>	/** Spliterator constructor */
2251	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it) {
2252	>	super(it);
2253	>	this.map = map;
2254	>	if (it == null) {
2255	>	Node<V>[] t = this.tab = map.table;
2256	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2257	>	long n = map.sumCount();
2258	>	batch = ((n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2259	>	(int)n);
2260	>	}
2261	>	else {
2262	>	this.tab = it.tab;
2263	>	this.baseSize = it.baseSize;
2264	>	int hi = this.baseLimit = it.baseLimit;
2265	>	it.baseLimit = this.index = this.baseIndex =
2266	>	(hi + it.baseIndex) >>> 1;
2267	>	this.batch = it.batch >>>= 1;
2268	>	}
2269	>	}
2270	>
2271	>	/**
2272	>	* Advances if possible, returning next valid value, or null if none.
2273	>	*/
2274	>	@SuppressWarnings("unchecked") final V advance() {
2275	>	for (Node<V> e = next;;) {
2276	>	if (e != null)                  // advance past used/skipped node
2277	>	e = next = e.next;
2278	>	while (e == null) {             // get to next non-null bin
2279	>	Node<V>[] t; int i, n;      // must use locals in checks
2280	>	if (baseIndex >= baseLimit || (t = tab) == null ||
2281	>	(n = t.length) <= (i = index) || i < 0)
2282	>	return nextVal = null;
2283	>	if ((e = next = tabAt(t, index)) != null && e.hash < 0) {
2284	>	Object ek;
2285	>	if ((ek = e.key) instanceof TreeBin)
2286	>	e = ((TreeBin<V>)ek).first;
2287	>	else {
2288	>	tab = (Node<V>[])ek;
2289	>	continue;           // restarts due to null val
2290	>	}
2291	>	}
2292	>	if ((index += baseSize) >= n)
2293	>	index = ++baseIndex;    // visit upper slots if present
2294	>	}
2295	>	nextKey = (K)e.key;
2296	>	if ((nextVal = e.val) != null) // skip deleted or special nodes
2297	>	return nextVal;
2298	>	}
2299	>	}
2300	>
2301	>	/**
2302	>	* Common case version for value traversal
2303	>	*/
2304	>	@SuppressWarnings("unchecked") final V advanceValue() {
2305	>	outer: for (Node<V> e = next;;) {
2306	>	if (e == null || (e = e.next) == null) {
2307	>	Node<V>[] t; int i, len, n; Object ek;
2308	>	if ((t = tab) == null ||
2309	>	baseSize != (len = t.length) ||
2310	>	len < (n = baseLimit) ||
2311	>	baseIndex != (i = index))
2312	>	break;
2313	>	do {
2314	>	if (i < 0 || i >= n) {
2315	>	index = baseIndex = n;
2316	>	next = null;
2317	>	return nextVal = null;
2318	>	}
2319	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2320	>	if ((ek = e.key) instanceof TreeBin)
2321	>	e = ((TreeBin<V>)ek).first;
2322	>	else {
2323	>	index = baseIndex = i;
2324	>	next = null;
2325	>	tab = (Node<V>[])ek;
2326	>	break outer;
2327	>	}
2328	>	}
2329	>	++i;
2330	>	} while (e == null);
2331	>	index = baseIndex = i;
2332	>	}
2333	>	V v;
2334	>	K k = (K)e.key;
2335	>	if ((v = e.val) != null) {
2336	>	nextVal = v;
2337	>	nextKey = k;
2338	>	next = e;
2339	>	return v;
2340	>	}
2341	>	}
2342	>	return advance();
2343	>	}
2344	>
2345	>	/**
2346	>	* Common case version for key traversal
2347	>	*/
2348	>	@SuppressWarnings("unchecked") final K advanceKey() {
2349	>	outer: for (Node<V> e = next;;) {
2350	>	if (e == null || (e = e.next) == null) {
2351	>	Node<V>[] t; int i, len, n; Object ek;
2352	>	if ((t = tab) == null ||
2353	>	baseSize != (len = t.length) ||
2354	>	len < (n = baseLimit) ||
2355	>	baseIndex != (i = index))
2356	>	break;
2357	>	do {
2358	>	if (i < 0 || i >= n) {
2359	>	index = baseIndex = n;
2360	>	next = null;
2361	>	nextVal = null;
2362	>	return null;
2363	>	}
2364	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2365	>	if ((ek = e.key) instanceof TreeBin)
2366	>	e = ((TreeBin<V>)ek).first;
2367	>	else {
2368	>	index = baseIndex = i;
2369	>	next = null;
2370	>	tab = (Node<V>[])ek;
2371	>	break outer;
2372	>	}
2373	>	}
2374	>	++i;
2375	>	} while (e == null);
2376	>	index = baseIndex = i;
2377	>	}
2378	>	V v;
2379	>	K k = (K)e.key;
2380	>	if ((v = e.val) != null) {
2381	>	nextVal = v;
2382	>	nextKey = k;
2383	>	next = e;
2384	>	return k;
2385	>	}
2386	>	}
2387	>	return (advance() == null) ? null : nextKey;
2388	>	}
2389	>
2390	>	@SuppressWarnings("unchecked") final void forEachValue(Consumer<? super V> action) {
2391	>	if (action == null) throw new NullPointerException();
2392	>	Node<V>[] t; int i, len, n;
2393	>	if ((t = tab) != null && baseSize == (len = t.length) &&
2394	>	len >= (n = baseLimit) && baseIndex == (i = index)) {
2395	>	index = baseIndex = n;
2396	>	nextVal = null;
2397	>	Node<V> e = next;
2398	>	next = null;
2399	>	if (e != null)
2400	>	e = e.next;
2401	>	outer: for (;; e = e.next) {
2402	>	V v; Object ek;
2403	>	for (; e == null; ++i) {
2404	>	if (i < 0 || i >= n)
2405	>	return;
2406	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2407	>	if ((ek = e.key) instanceof TreeBin)
2408	>	e = ((TreeBin<V>)ek).first;
2409	>	else {
2410	>	index = baseIndex = i;
2411	>	tab = (Node<V>[])ek;
2412	>	break outer;
2413	>	}
2414	>	}
2415	>	}
2416	>	if ((v = e.val) != null)
2417	>	action.accept(v);
2418	>	}
2419	>	}
2420	>	V v;
2421	>	while ((v = advance()) != null)
2422	>	action.accept(v);
2423	>	}
2424	>
2425	>	@SuppressWarnings("unchecked") final void forEachKey(Consumer<? super K> action) {
2426	>	if (action == null) throw new NullPointerException();
2427	>	Node<V>[] t; int i, len, n;
2428	>	if ((t = tab) != null && baseSize == (len = t.length) &&
2429	>	len >= (n = baseLimit) && baseIndex == (i = index)) {
2430	>	index = baseIndex = n;
2431	>	nextVal = null;
2432	>	Node<V> e = next;
2433	>	next = null;
2434	>	if (e != null)
2435	>	e = e.next;
2436	>	outer: for (;; e = e.next) {
2437	>	for (; e == null; ++i) {
2438	>	if (i < 0 || i >= n)
2439	>	return;
2440	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2441	>	Object ek;
2442	>	if ((ek = e.key) instanceof TreeBin)
2443	>	e = ((TreeBin<V>)ek).first;
2444	>	else {
2445	>	index = baseIndex = i;
2446	>	tab = (Node<V>[])ek;
2447	>	break outer;
2448	>	}
2449	>	}
2450	>	}
2451	>	Object k = e.key;
2452	>	if (e.val != null)
2453	>	action.accept((K)k);
2454	>	}
2455	>	}
2456	>	while (advance() != null)
2457	>	action.accept(nextKey);
2458	>	}
2459	>
2460	>	public final void remove() {
2461	>	K k = nextKey;
2462	>	if (k == null && (advanceValue() == null || (k = nextKey) == null))
2463	>	throw new IllegalStateException();
2464	>	map.internalReplace(k, null, null);
2465	>	}
2466	>
2467	>	public final boolean hasNext() {
2468	>	return nextVal != null || advanceValue() != null;
2469	>	}
2470	>
2471	>	public final boolean hasMoreElements() { return hasNext(); }
2472	>
2473	>	public void compute() { } // default no-op CountedCompleter body
2474	>
2475	>	public long estimateSize() { return batch; }
2476	>
2477	>	/**
2478	>	* Returns a batch value > 0 if this task should (and must) be
2479	>	* split, if so, adding to pending count, and in any case
2480	>	* updating batch value. The initial batch value is approx
2481	>	* exp2 of the number of times (minus one) to split task by
2482	>	* two before executing leaf action. This value is faster to
2483	>	* compute and more convenient to use as a guide to splitting
2484	>	* than is the depth, since it is used while dividing by two
2485	>	* anyway.
2486	>	*/
2487	>	final int preSplit() {
2488	>	int b;  ForkJoinPool pool;
2489	>	if ((b = batch) < 0) { // force initialization
2490	>	int sp = (((pool = getPool()) == null) ?
2491	>	ForkJoinPool.getCommonPoolParallelism() :
2492	>	pool.getParallelism()) << 3; // slack of 8
2493	>	long n = map.sumCount();
2494	>	b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2495	>	}
2496	>	b = (b <= 1 || baseIndex >= baseLimit) ? 0 : (b >>> 1);
2497	>	if ((batch = b) > 0)
2498	>	addToPendingCount(1);
2499	>	return b;
2500	>	}
2501	>	}
2502	>
2503	>	/* ---------------- Public operations -------------- */
2504	>
2505	>	/**
2506	>	* Creates a new, empty map with the default initial table size (16).
2507		*/
2508	<	@SuppressWarnings("unchecked")
706	<	public ConcurrentHashMap(int initialCapacity,
707	<	float loadFactor, int concurrencyLevel) {
708	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
709	<	throw new IllegalArgumentException();
710	<	if (concurrencyLevel > MAX_SEGMENTS)
711	<	concurrencyLevel = MAX_SEGMENTS;
712	<	// Find power-of-two sizes best matching arguments
713	<	int sshift = 0;
714	<	int ssize = 1;
715	<	while (ssize < concurrencyLevel) {
716	<	++sshift;
717	<	ssize <<= 1;
718	<	}
719	<	this.segmentShift = 32 - sshift;
720	<	this.segmentMask = ssize - 1;
721	<	if (initialCapacity > MAXIMUM_CAPACITY)
722	<	initialCapacity = MAXIMUM_CAPACITY;
723	<	int c = initialCapacity / ssize;
724	<	if (c * ssize < initialCapacity)
725	<	++c;
726	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
727	<	while (cap < c)
728	<	cap <<= 1;
729	<	// create segments and segments[0]
730	<	Segment<K,V> s0 =
731	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
732	<	(HashEntry<K,V>[])new HashEntry[cap]);
733	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment[ssize];
734	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
735	<	this.segments = ss;
2508	>	public ConcurrentHashMap() {
2509		}
2510
2511		/**
2512	<	* Creates a new, empty map with the specified initial capacity
2513	<	* and load factor and with the default concurrencyLevel (16).
2512	>	* Creates a new, empty map with an initial table size
2513	>	* accommodating the specified number of elements without the need
2514	>	* to dynamically resize.
2515		*
2516		* @param initialCapacity The implementation performs internal
2517		* sizing to accommodate this many elements.
2518	<	* @param loadFactor  the load factor threshold, used to control resizing.
2519	<	* Resizing may be performed when the average number of elements per
2520	<	* bin exceeds this threshold.
2518	>	* @throws IllegalArgumentException if the initial capacity of
2519	>	* elements is negative
2520	>	*/
2521	>	public ConcurrentHashMap(int initialCapacity) {
2522	>	if (initialCapacity < 0)
2523	>	throw new IllegalArgumentException();
2524	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2525	>	MAXIMUM_CAPACITY :
2526	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2527	>	this.sizeCtl = cap;
2528	>	}
2529	>
2530	>	/**
2531	>	* Creates a new map with the same mappings as the given map.
2532	>	*
2533	>	* @param m the map
2534	>	*/
2535	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2536	>	this.sizeCtl = DEFAULT_CAPACITY;
2537	>	internalPutAll(m);
2538	>	}
2539	>
2540	>	/**
2541	>	* Creates a new, empty map with an initial table size based on
2542	>	* the given number of elements ({@code initialCapacity}) and
2543	>	* initial table density ({@code loadFactor}).
2544	>	*
2545	>	* @param initialCapacity the initial capacity. The implementation
2546	>	* performs internal sizing to accommodate this many elements,
2547	>	* given the specified load factor.
2548	>	* @param loadFactor the load factor (table density) for
2549	>	* establishing the initial table size
2550		* @throws IllegalArgumentException if the initial capacity of
2551		* elements is negative or the load factor is nonpositive
2552		*
2553		* @since 1.6
2554		*/
2555		public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2556	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
2556	>	this(initialCapacity, loadFactor, 1);
2557		}
2558
2559		/**
2560	<	* Creates a new, empty map with the specified initial capacity,
2561	<	* and with default load factor (0.75) and concurrencyLevel (16).
2560	>	* Creates a new, empty map with an initial table size based on
2561	>	* the given number of elements ({@code initialCapacity}), table
2562	>	* density ({@code loadFactor}), and number of concurrently
2563	>	* updating threads ({@code concurrencyLevel}).
2564		*
2565		* @param initialCapacity the initial capacity. The implementation
2566	<	* performs internal sizing to accommodate this many elements.
2567	<	* @throws IllegalArgumentException if the initial capacity of
2568	<	* elements is negative.
2566	>	* performs internal sizing to accommodate this many elements,
2567	>	* given the specified load factor.
2568	>	* @param loadFactor the load factor (table density) for
2569	>	* establishing the initial table size
2570	>	* @param concurrencyLevel the estimated number of concurrently
2571	>	* updating threads. The implementation may use this value as
2572	>	* a sizing hint.
2573	>	* @throws IllegalArgumentException if the initial capacity is
2574	>	* negative or the load factor or concurrencyLevel are
2575	>	* nonpositive
2576		*/
2577	<	public ConcurrentHashMap(int initialCapacity) {
2578	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2577	>	public ConcurrentHashMap(int initialCapacity,
2578	>	float loadFactor, int concurrencyLevel) {
2579	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2580	>	throw new IllegalArgumentException();
2581	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2582	>	initialCapacity = concurrencyLevel;   // as estimated threads
2583	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2584	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2585	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2586	>	this.sizeCtl = cap;
2587		}
2588
2589		/**
2590	<	* Creates a new, empty map with a default initial capacity (16),
2591	<	* load factor (0.75) and concurrencyLevel (16).
2590	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2591	>	* from the given type to {@code Boolean.TRUE}.
2592	>	*
2593	>	* @return the new set
2594		*/
2595	<	public ConcurrentHashMap() {
2596	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2595	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2596	>	return new KeySetView<K,Boolean>
2597	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2598		}
2599
2600		/**
2601	<	* Creates a new map with the same mappings as the given map.
2602	<	* The map is created with a capacity of 1.5 times the number
780	<	* of mappings in the given map or 16 (whichever is greater),
781	<	* and a default load factor (0.75) and concurrencyLevel (16).
2601	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2602	>	* from the given type to {@code Boolean.TRUE}.
2603		*
2604	<	* @param m the map
2604	>	* @param initialCapacity The implementation performs internal
2605	>	* sizing to accommodate this many elements.
2606	>	* @throws IllegalArgumentException if the initial capacity of
2607	>	* elements is negative
2608	>	* @return the new set
2609		*/
2610	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2611	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
2612	<	DEFAULT_INITIAL_CAPACITY),
788	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
2610	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2611	>	return new KeySetView<K,Boolean>
2612	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2613		}
2614
2615		/**
2616	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
794	<	*
795	<	* @return <tt>true</tt> if this map contains no key-value mappings
2616	>	* {@inheritDoc}
2617		*/
2618		public boolean isEmpty() {
2619	<	/*
799	<	* Sum per-segment modCounts to avoid mis-reporting when
800	<	* elements are concurrently added and removed in one segment
801	<	* while checking another, in which case the table was never
802	<	* actually empty at any point. (The sum ensures accuracy up
803	<	* through at least 1<<31 per-segment modifications before
804	<	* recheck.)  Methods size() and containsValue() use similar
805	<	* constructions for stability checks.
806	<	*/
807	<	long sum = 0L;
808	<	final Segment<K,V>[] segments = this.segments;
809	<	for (int j = 0; j < segments.length; ++j) {
810	<	Segment<K,V> seg = segmentAt(segments, j);
811	<	if (seg != null) {
812	<	if (seg.count != 0)
813	<	return false;
814	<	sum += seg.modCount;
815	<	}
816	<	}
817	<	if (sum != 0L) { // recheck unless no modifications
818	<	for (int j = 0; j < segments.length; ++j) {
819	<	Segment<K,V> seg = segmentAt(segments, j);
820	<	if (seg != null) {
821	<	if (seg.count != 0)
822	<	return false;
823	<	sum -= seg.modCount;
824	<	}
825	<	}
826	<	if (sum != 0L)
827	<	return false;
828	<	}
829	<	return true;
2619	>	return sumCount() <= 0L; // ignore transient negative values
2620		}
2621
2622		/**
2623	<	* Returns the number of key-value mappings in this map.  If the
834	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
835	<	* <tt>Integer.MAX_VALUE</tt>.
836	<	*
837	<	* @return the number of key-value mappings in this map
2623	>	* {@inheritDoc}
2624		*/
2625		public int size() {
2626	<	// Try a few times to get accurate count. On failure due to
2627	<	// continuous async changes in table, resort to locking.
2628	<	final Segment<K,V>[] segments = this.segments;
2629	<	int size;
2630	<	boolean overflow; // true if size overflows 32 bits
2631	<	long sum;         // sum of modCounts
2632	<	long last = 0L;   // previous sum
2633	<	int retries = -1; // first iteration isn't retry
2634	<	try {
2635	<	for (;;) {
2636	<	if (retries++ == RETRIES_BEFORE_LOCK) {
2637	<	for (int j = 0; j < segments.length; ++j)
2638	<	ensureSegment(j).lock(); // force creation
2639	<	}
2640	<	sum = 0L;
2641	<	size = 0;
2642	<	overflow = false;
2643	<	for (int j = 0; j < segments.length; ++j) {
858	<	Segment<K,V> seg = segmentAt(segments, j);
859	<	if (seg != null) {
860	<	sum += seg.modCount;
861	<	int c = seg.count;
862	<	if (c < 0 || (size += c) < 0)
863	<	overflow = true;
864	<	}
865	<	}
866	<	if (sum == last)
867	<	break;
868	<	last = sum;
869	<	}
870	<	} finally {
871	<	if (retries > RETRIES_BEFORE_LOCK) {
872	<	for (int j = 0; j < segments.length; ++j)
873	<	segmentAt(segments, j).unlock();
874	<	}
875	<	}
876	<	return overflow ? Integer.MAX_VALUE : size;
2626	>	long n = sumCount();
2627	>	return ((n < 0L) ? 0 :
2628	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2629	>	(int)n);
2630	>	}
2631	>
2632	>	/**
2633	>	* Returns the number of mappings. This method should be used
2634	>	* instead of {@link #size} because a ConcurrentHashMap may
2635	>	* contain more mappings than can be represented as an int. The
2636	>	* value returned is an estimate; the actual count may differ if
2637	>	* there are concurrent insertions or removals.
2638	>	*
2639	>	* @return the number of mappings
2640	>	*/
2641	>	public long mappingCount() {
2642	>	long n = sumCount();
2643	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2644		}
2645
2646		/**
#	Line 888 | Line 2655 | public class ConcurrentHashMap<K, V> ext
2655		* @throws NullPointerException if the specified key is null
2656		*/
2657		public V get(Object key) {
2658	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
2659	<	HashEntry<K,V>[] tab;
2660	<	int h = hash(key.hashCode());
2661	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
2662	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
2663	<	(tab = s.table) != null) {
2664	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
2665	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
2666	<	e != null; e = e.next) {
2667	<	K k;
2668	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
2669	<	return e.value;
2670	<	}
2671	<	}
2672	<	return null;
2658	>	return internalGet(key);
2659	>	}
2660	>
2661	>	/**
2662	>	* Returns the value to which the specified key is mapped,
2663	>	* or the given defaultValue if this map contains no mapping for the key.
2664	>	*
2665	>	* @param key the key
2666	>	* @param defaultValue the value to return if this map contains
2667	>	* no mapping for the given key
2668	>	* @return the mapping for the key, if present; else the defaultValue
2669	>	* @throws NullPointerException if the specified key is null
2670	>	*/
2671	>	public V getOrDefault(Object key, V defaultValue) {
2672	>	V v;
2673	>	return (v = internalGet(key)) == null ? defaultValue : v;
2674		}
2675
2676		/**
2677		* Tests if the specified object is a key in this table.
2678		*
2679	<	* @param  key   possible key
2680	<	* @return <tt>true</tt> if and only if the specified object
2679	>	* @param  key possible key
2680	>	* @return {@code true} if and only if the specified object
2681		*         is a key in this table, as determined by the
2682	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
2682	>	*         {@code equals} method; {@code false} otherwise
2683		* @throws NullPointerException if the specified key is null
2684		*/
917	–	@SuppressWarnings("unchecked")
2685		public boolean containsKey(Object key) {
2686	<	Segment<K,V> s; // same as get() except no need for volatile value read
920	<	HashEntry<K,V>[] tab;
921	<	int h = hash(key.hashCode());
922	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
923	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
924	<	(tab = s.table) != null) {
925	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
926	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
927	<	e != null; e = e.next) {
928	<	K k;
929	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
930	<	return true;
931	<	}
932	<	}
933	<	return false;
2686	>	return internalGet(key) != null;
2687		}
2688
2689		/**
2690	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2691	<	* specified value. Note: This method requires a full internal
2692	<	* traversal of the hash table, and so is much slower than
940	<	* method <tt>containsKey</tt>.
2690	>	* Returns {@code true} if this map maps one or more keys to the
2691	>	* specified value. Note: This method may require a full traversal
2692	>	* of the map, and is much slower than method {@code containsKey}.
2693		*
2694		* @param value value whose presence in this map is to be tested
2695	<	* @return <tt>true</tt> if this map maps one or more keys to the
2695	>	* @return {@code true} if this map maps one or more keys to the
2696		*         specified value
2697		* @throws NullPointerException if the specified value is null
2698		*/
2699		public boolean containsValue(Object value) {
948	–	// Same idea as size()
2700		if (value == null)
2701		throw new NullPointerException();
2702	<	final Segment<K,V>[] segments = this.segments;
2703	<	boolean found = false;
2704	<	long last = 0L;   // previous sum
2705	<	int retries = -1;
2706	<	try {
956	<	outer: for (;;) {
957	<	if (retries++ == RETRIES_BEFORE_LOCK) {
958	<	for (int j = 0; j < segments.length; ++j)
959	<	ensureSegment(j).lock(); // force creation
960	<	}
961	<	long sum = 0L;
962	<	for (int j = 0; j < segments.length; ++j) {
963	<	HashEntry<K,V>[] tab;
964	<	Segment<K,V> seg = segmentAt(segments, j);
965	<	if (seg != null && (tab = seg.table) != null) {
966	<	for (int i = 0 ; i < tab.length; i++) {
967	<	HashEntry<K,V> e;
968	<	for (e = entryAt(tab, i); e != null; e = e.next) {
969	<	V v = e.value;
970	<	if (v != null && value.equals(v)) {
971	<	found = true;
972	<	break outer;
973	<	}
974	<	}
975	<	}
976	<	sum += seg.modCount;
977	<	}
978	<	}
979	<	if (retries > 0 && sum == last)
980	<	break;
981	<	last = sum;
982	<	}
983	<	} finally {
984	<	if (retries > RETRIES_BEFORE_LOCK) {
985	<	for (int j = 0; j < segments.length; ++j)
986	<	segmentAt(segments, j).unlock();
987	<	}
2702	>	V v;
2703	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2704	>	while ((v = it.advanceValue()) != null) {
2705	>	if (v == value || value.equals(v))
2706	>	return true;
2707		}
2708	<	return found;
2708	>	return false;
2709		}
2710
2711		/**
2712		* Legacy method testing if some key maps into the specified value
2713		* in this table.  This method is identical in functionality to
2714	<	* {@link #containsValue}, and exists solely to ensure
2714	>	* {@link #containsValue(Object)}, and exists solely to ensure
2715		* full compatibility with class {@link java.util.Hashtable},
2716		* which supported this method prior to introduction of the
2717		* Java Collections framework.
2718		*
2719		* @param  value a value to search for
2720	<	* @return <tt>true</tt> if and only if some key maps to the
2721	<	*         <tt>value</tt> argument in this table as
2722	<	*         determined by the <tt>equals</tt> method;
2723	<	*         <tt>false</tt> otherwise
2720	>	* @return {@code true} if and only if some key maps to the
2721	>	*         {@code value} argument in this table as
2722	>	*         determined by the {@code equals} method;
2723	>	*         {@code false} otherwise
2724		* @throws NullPointerException if the specified value is null
2725		*/
2726	<	public boolean contains(Object value) {
2726	>	@Deprecated public boolean contains(Object value) {
2727		return containsValue(value);
2728		}
2729
#	Line 1012 | Line 2731 | public class ConcurrentHashMap<K, V> ext
2731		* Maps the specified key to the specified value in this table.
2732		* Neither the key nor the value can be null.
2733		*
2734	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
2734	>	* <p>The value can be retrieved by calling the {@code get} method
2735		* with a key that is equal to the original key.
2736		*
2737		* @param key key with which the specified value is to be associated
2738		* @param value value to be associated with the specified key
2739	<	* @return the previous value associated with <tt>key</tt>, or
2740	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2739	>	* @return the previous value associated with {@code key}, or
2740	>	*         {@code null} if there was no mapping for {@code key}
2741		* @throws NullPointerException if the specified key or value is null
2742		*/
1024	–	@SuppressWarnings("unchecked")
2743		public V put(K key, V value) {
2744	<	Segment<K,V> s;
1027	<	if (value == null)
1028	<	throw new NullPointerException();
1029	<	int hash = hash(key.hashCode());
1030	<	int j = (hash >>> segmentShift) & segmentMask;
1031	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1032	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1033	<	s = ensureSegment(j);
1034	<	return s.put(key, hash, value, false);
2744	>	return internalPut(key, value, false);
2745		}
2746
2747		/**
2748		* {@inheritDoc}
2749		*
2750		* @return the previous value associated with the specified key,
2751	<	*         or <tt>null</tt> if there was no mapping for the key
2751	>	*         or {@code null} if there was no mapping for the key
2752		* @throws NullPointerException if the specified key or value is null
2753		*/
1044	–	@SuppressWarnings("unchecked")
2754		public V putIfAbsent(K key, V value) {
2755	<	Segment<K,V> s;
1047	<	if (value == null)
1048	<	throw new NullPointerException();
1049	<	int hash = hash(key.hashCode());
1050	<	int j = (hash >>> segmentShift) & segmentMask;
1051	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1052	<	(segments, (j << SSHIFT) + SBASE)) == null)
1053	<	s = ensureSegment(j);
1054	<	return s.put(key, hash, value, true);
2755	>	return internalPut(key, value, true);
2756		}
2757
2758		/**
#	Line 1062 | Line 2763 | public class ConcurrentHashMap<K, V> ext
2763		* @param m mappings to be stored in this map
2764		*/
2765		public void putAll(Map<? extends K, ? extends V> m) {
2766	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2767	<	put(e.getKey(), e.getValue());
2766	>	internalPutAll(m);
2767	>	}
2768	>
2769	>	/**
2770	>	* If the specified key is not already associated with a value (or
2771	>	* is mapped to {@code null}), attempts to compute its value using
2772	>	* the given mapping function and enters it into this map unless
2773	>	* {@code null}. The entire method invocation is performed
2774	>	* atomically, so the function is applied at most once per key.
2775	>	* Some attempted update operations on this map by other threads
2776	>	* may be blocked while computation is in progress, so the
2777	>	* computation should be short and simple, and must not attempt to
2778	>	* update any other mappings of this Map.
2779	>	*
2780	>	* @param key key with which the specified value is to be associated
2781	>	* @param mappingFunction the function to compute a value
2782	>	* @return the current (existing or computed) value associated with
2783	>	*         the specified key, or null if the computed value is null
2784	>	* @throws NullPointerException if the specified key or mappingFunction
2785	>	*         is null
2786	>	* @throws IllegalStateException if the computation detectably
2787	>	*         attempts a recursive update to this map that would
2788	>	*         otherwise never complete
2789	>	* @throws RuntimeException or Error if the mappingFunction does so,
2790	>	*         in which case the mapping is left unestablished
2791	>	*/
2792	>	public V computeIfAbsent
2793	>	(K key, Function<? super K, ? extends V> mappingFunction) {
2794	>	return internalComputeIfAbsent(key, mappingFunction);
2795	>	}
2796	>
2797	>	/**
2798	>	* If the value for the specified key is present and non-null,
2799	>	* attempts to compute a new mapping given the key and its current
2800	>	* mapped value.  The entire method invocation is performed
2801	>	* atomically.  Some attempted update operations on this map by
2802	>	* other threads may be blocked while computation is in progress,
2803	>	* so the computation should be short and simple, and must not
2804	>	* attempt to update any other mappings of this Map.
2805	>	*
2806	>	* @param key key with which a value may be associated
2807	>	* @param remappingFunction the function to compute a value
2808	>	* @return the new value associated with the specified key, or null if none
2809	>	* @throws NullPointerException if the specified key or remappingFunction
2810	>	*         is null
2811	>	* @throws IllegalStateException if the computation detectably
2812	>	*         attempts a recursive update to this map that would
2813	>	*         otherwise never complete
2814	>	* @throws RuntimeException or Error if the remappingFunction does so,
2815	>	*         in which case the mapping is unchanged
2816	>	*/
2817	>	public V computeIfPresent
2818	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2819	>	return internalCompute(key, true, remappingFunction);
2820	>	}
2821	>
2822	>	/**
2823	>	* Attempts to compute a mapping for the specified key and its
2824	>	* current mapped value (or {@code null} if there is no current
2825	>	* mapping). The entire method invocation is performed atomically.
2826	>	* Some attempted update operations on this map by other threads
2827	>	* may be blocked while computation is in progress, so the
2828	>	* computation should be short and simple, and must not attempt to
2829	>	* update any other mappings of this Map.
2830	>	*
2831	>	* @param key key with which the specified value is to be associated
2832	>	* @param remappingFunction the function to compute a value
2833	>	* @return the new value associated with the specified key, or null if none
2834	>	* @throws NullPointerException if the specified key or remappingFunction
2835	>	*         is null
2836	>	* @throws IllegalStateException if the computation detectably
2837	>	*         attempts a recursive update to this map that would
2838	>	*         otherwise never complete
2839	>	* @throws RuntimeException or Error if the remappingFunction does so,
2840	>	*         in which case the mapping is unchanged
2841	>	*/
2842	>	public V compute
2843	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2844	>	return internalCompute(key, false, remappingFunction);
2845	>	}
2846	>
2847	>	/**
2848	>	* If the specified key is not already associated with a
2849	>	* (non-null) value, associates it with the given value.
2850	>	* Otherwise, replaces the value with the results of the given
2851	>	* remapping function, or removes if {@code null}. The entire
2852	>	* method invocation is performed atomically.  Some attempted
2853	>	* update operations on this map by other threads may be blocked
2854	>	* while computation is in progress, so the computation should be
2855	>	* short and simple, and must not attempt to update any other
2856	>	* mappings of this Map.
2857	>	*
2858	>	* @param key key with which the specified value is to be associated
2859	>	* @param value the value to use if absent
2860	>	* @param remappingFunction the function to recompute a value if present
2861	>	* @return the new value associated with the specified key, or null if none
2862	>	* @throws NullPointerException if the specified key or the
2863	>	*         remappingFunction is null
2864	>	* @throws RuntimeException or Error if the remappingFunction does so,
2865	>	*         in which case the mapping is unchanged
2866	>	*/
2867	>	public V merge
2868	>	(K key, V value,
2869	>	BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2870	>	return internalMerge(key, value, remappingFunction);
2871		}
2872
2873		/**
#	Line 1071 | Line 2875 | public class ConcurrentHashMap<K, V> ext
2875		* This method does nothing if the key is not in the map.
2876		*
2877		* @param  key the key that needs to be removed
2878	<	* @return the previous value associated with <tt>key</tt>, or
2879	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2878	>	* @return the previous value associated with {@code key}, or
2879	>	*         {@code null} if there was no mapping for {@code key}
2880		* @throws NullPointerException if the specified key is null
2881		*/
2882		public V remove(Object key) {
2883	<	int hash = hash(key.hashCode());
1080	<	Segment<K,V> s = segmentForHash(hash);
1081	<	return s == null ? null : s.remove(key, hash, null);
2883	>	return internalReplace(key, null, null);
2884		}
2885
2886		/**
#	Line 1087 | Line 2889 | public class ConcurrentHashMap<K, V> ext
2889		* @throws NullPointerException if the specified key is null
2890		*/
2891		public boolean remove(Object key, Object value) {
2892	<	int hash = hash(key.hashCode());
2893	<	Segment<K,V> s;
2894	<	return value != null && (s = segmentForHash(hash)) != null &&
1093	<	s.remove(key, hash, value) != null;
2892	>	if (key == null)
2893	>	throw new NullPointerException();
2894	>	return value != null && internalReplace(key, null, value) != null;
2895		}
2896
2897		/**
#	Line 1099 | Line 2900 | public class ConcurrentHashMap<K, V> ext
2900		* @throws NullPointerException if any of the arguments are null
2901		*/
2902		public boolean replace(K key, V oldValue, V newValue) {
2903	<	int hash = hash(key.hashCode());
1103	<	if (oldValue == null || newValue == null)
2903	>	if (key == null || oldValue == null || newValue == null)
2904		throw new NullPointerException();
2905	<	Segment<K,V> s = segmentForHash(hash);
1106	<	return s != null && s.replace(key, hash, oldValue, newValue);
2905	>	return internalReplace(key, newValue, oldValue) != null;
2906		}
2907
2908		/**
2909		* {@inheritDoc}
2910		*
2911		* @return the previous value associated with the specified key,
2912	<	*         or <tt>null</tt> if there was no mapping for the key
2912	>	*         or {@code null} if there was no mapping for the key
2913		* @throws NullPointerException if the specified key or value is null
2914		*/
2915		public V replace(K key, V value) {
2916	<	int hash = hash(key.hashCode());
1118	<	if (value == null)
2916	>	if (key == null || value == null)
2917		throw new NullPointerException();
2918	<	Segment<K,V> s = segmentForHash(hash);
1121	<	return s == null ? null : s.replace(key, hash, value);
2918	>	return internalReplace(key, value, null);
2919		}
2920
2921		/**
2922		* Removes all of the mappings from this map.
2923		*/
2924		public void clear() {
2925	<	final Segment<K,V>[] segments = this.segments;
1129	<	for (int j = 0; j < segments.length; ++j) {
1130	<	Segment<K,V> s = segmentAt(segments, j);
1131	<	if (s != null)
1132	<	s.clear();
1133	<	}
2925	>	internalClear();
2926		}
2927
2928		/**
2929		* Returns a {@link Set} view of the keys contained in this map.
2930		* The set is backed by the map, so changes to the map are
2931	<	* reflected in the set, and vice-versa.  The set supports element
1140	<	* removal, which removes the corresponding mapping from this map,
1141	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1142	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1143	<	* operations.  It does not support the <tt>add</tt> or
1144	<	* <tt>addAll</tt> operations.
2931	>	* reflected in the set, and vice-versa.
2932		*
2933	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2934	<	* that will never throw {@link ConcurrentModificationException},
2935	<	* and guarantees to traverse elements as they existed upon
2936	<	* construction of the iterator, and may (but is not guaranteed to)
2937	<	* reflect any modifications subsequent to construction.
2933	>	* @return the set view
2934	>	*/
2935	>	public KeySetView<K,V> keySet() {
2936	>	KeySetView<K,V> ks = keySet;
2937	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2938	>	}
2939	>
2940	>	/**
2941	>	* Returns a {@link Set} view of the keys in this map, using the
2942	>	* given common mapped value for any additions (i.e., {@link
2943	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2944	>	* This is of course only appropriate if it is acceptable to use
2945	>	* the same value for all additions from this view.
2946	>	*
2947	>	* @param mappedValue the mapped value to use for any additions
2948	>	* @return the set view
2949	>	* @throws NullPointerException if the mappedValue is null
2950		*/
2951	<	public Set<K> keySet() {
2952	<	Set<K> ks = keySet;
2953	<	return (ks != null) ? ks : (keySet = new KeySet());
2951	>	public KeySetView<K,V> keySet(V mappedValue) {
2952	>	if (mappedValue == null)
2953	>	throw new NullPointerException();
2954	>	return new KeySetView<K,V>(this, mappedValue);
2955		}
2956
2957		/**
2958		* Returns a {@link Collection} view of the values contained in this map.
2959		* The collection is backed by the map, so changes to the map are
2960	<	* reflected in the collection, and vice-versa.  The collection
1161	<	* supports element removal, which removes the corresponding
1162	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1163	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1164	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1165	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
2960	>	* reflected in the collection, and vice-versa.
2961		*
2962	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1168	<	* that will never throw {@link ConcurrentModificationException},
1169	<	* and guarantees to traverse elements as they existed upon
1170	<	* construction of the iterator, and may (but is not guaranteed to)
1171	<	* reflect any modifications subsequent to construction.
2962	>	* @return the collection view
2963		*/
2964	<	public Collection<V> values() {
2965	<	Collection<V> vs = values;
2966	<	return (vs != null) ? vs : (values = new Values());
2964	>	public ValuesView<K,V> values() {
2965	>	ValuesView<K,V> vs = values;
2966	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2967		}
2968
2969		/**
#	Line 1180 | Line 2971 | public class ConcurrentHashMap<K, V> ext
2971		* The set is backed by the map, so changes to the map are
2972		* reflected in the set, and vice-versa.  The set supports element
2973		* removal, which removes the corresponding mapping from the map,
2974	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2975	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2976	<	* operations.  It does not support the <tt>add</tt> or
2977	<	* <tt>addAll</tt> operations.
2974	>	* via the {@code Iterator.remove}, {@code Set.remove},
2975	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2976	>	* operations.  It does not support the {@code add} or
2977	>	* {@code addAll} operations.
2978		*
2979	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2979	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
2980		* that will never throw {@link ConcurrentModificationException},
2981		* and guarantees to traverse elements as they existed upon
2982		* construction of the iterator, and may (but is not guaranteed to)
2983		* reflect any modifications subsequent to construction.
2984	+	*
2985	+	* @return the set view
2986		*/
2987		public Set<Map.Entry<K,V>> entrySet() {
2988	<	Set<Map.Entry<K,V>> es = entrySet;
2989	<	return (es != null) ? es : (entrySet = new EntrySet());
2988	>	EntrySetView<K,V> es = entrySet;
2989	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
2990		}
2991
2992		/**
#	Line 1203 | Line 2996 | public class ConcurrentHashMap<K, V> ext
2996		* @see #keySet()
2997		*/
2998		public Enumeration<K> keys() {
2999	<	return new KeyIterator();
2999	>	return new KeyIterator<K,V>(this);
3000		}
3001
3002		/**
#	Line 1213 | Line 3006 | public class ConcurrentHashMap<K, V> ext
3006		* @see #values()
3007		*/
3008		public Enumeration<V> elements() {
3009	<	return new ValueIterator();
3009	>	return new ValueIterator<K,V>(this);
3010		}
3011
3012	<	/* ---------------- Iterator Support -------------- */
3013	<
3014	<	abstract class HashIterator {
3015	<	int nextSegmentIndex;
3016	<	int nextTableIndex;
3017	<	HashEntry<K,V>[] currentTable;
3018	<	HashEntry<K, V> nextEntry;
3019	<	HashEntry<K, V> lastReturned;
3020	<
3021	<	HashIterator() {
3022	<	nextSegmentIndex = segments.length - 1;
3023	<	nextTableIndex = -1;
3024	<	advance();
3025	<	}
3012	>	/**
3013	>	* Returns the hash code value for this {@link Map}, i.e.,
3014	>	* the sum of, for each key-value pair in the map,
3015	>	* {@code key.hashCode() ^ value.hashCode()}.
3016	>	*
3017	>	* @return the hash code value for this map
3018	>	*/
3019	>	public int hashCode() {
3020	>	int h = 0;
3021	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3022	>	V v;
3023	>	while ((v = it.advanceValue()) != null) {
3024	>	h += it.nextKey.hashCode() ^ v.hashCode();
3025	>	}
3026	>	return h;
3027	>	}
3028
3029	<	/**
3030	<	* Sets nextEntry to first node of next non-empty table
3031	<	* (in backwards order, to simplify checks).
3032	<	*/
3033	<	final void advance() {
3029	>	/**
3030	>	* Returns a string representation of this map.  The string
3031	>	* representation consists of a list of key-value mappings (in no
3032	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
3033	>	* mappings are separated by the characters {@code ", "} (comma
3034	>	* and space).  Each key-value mapping is rendered as the key
3035	>	* followed by an equals sign ("{@code =}") followed by the
3036	>	* associated value.
3037	>	*
3038	>	* @return a string representation of this map
3039	>	*/
3040	>	public String toString() {
3041	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3042	>	StringBuilder sb = new StringBuilder();
3043	>	sb.append('{');
3044	>	V v;
3045	>	if ((v = it.advanceValue()) != null) {
3046		for (;;) {
3047	<	if (nextTableIndex >= 0) {
3048	<	if ((nextEntry = entryAt(currentTable,
3049	<	nextTableIndex--)) != null)
3050	<	break;
3051	<	}
1245	<	else if (nextSegmentIndex >= 0) {
1246	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
1247	<	if (seg != null && (currentTable = seg.table) != null)
1248	<	nextTableIndex = currentTable.length - 1;
1249	<	}
1250	<	else
3047	>	K k = it.nextKey;
3048	>	sb.append(k == this ? "(this Map)" : k);
3049	>	sb.append('=');
3050	>	sb.append(v == this ? "(this Map)" : v);
3051	>	if ((v = it.advanceValue()) == null)
3052		break;
3053	+	sb.append(',').append(' ');
3054	+	}
3055	+	}
3056	+	return sb.append('}').toString();
3057	+	}
3058	+
3059	+	/**
3060	+	* Compares the specified object with this map for equality.
3061	+	* Returns {@code true} if the given object is a map with the same
3062	+	* mappings as this map.  This operation may return misleading
3063	+	* results if either map is concurrently modified during execution
3064	+	* of this method.
3065	+	*
3066	+	* @param o object to be compared for equality with this map
3067	+	* @return {@code true} if the specified object is equal to this map
3068	+	*/
3069	+	public boolean equals(Object o) {
3070	+	if (o != this) {
3071	+	if (!(o instanceof Map))
3072	+	return false;
3073	+	Map<?,?> m = (Map<?,?>) o;
3074	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3075	+	V val;
3076	+	while ((val = it.advanceValue()) != null) {
3077	+	Object v = m.get(it.nextKey);
3078	+	if (v == null || (v != val && !v.equals(val)))
3079	+	return false;
3080	+	}
3081	+	for (Map.Entry<?,?> e : m.entrySet()) {
3082	+	Object mk, mv, v;
3083	+	if ((mk = e.getKey()) == null ||
3084	+	(mv = e.getValue()) == null ||
3085	+	(v = internalGet(mk)) == null ||
3086	+	(mv != v && !mv.equals(v)))
3087	+	return false;
3088		}
3089		}
3090	+	return true;
3091	+	}
3092
3093	<	final HashEntry<K,V> nextEntry() {
3094	<	HashEntry<K,V> e = nextEntry;
3095	<	if (e == null)
3093	>	/* ----------------Iterators -------------- */
3094	>
3095	>	@SuppressWarnings("serial") static final class KeyIterator<K,V>
3096	>	extends Traverser<K,V,Object>
3097	>	implements Spliterator<K>, Iterator<K>, Enumeration<K> {
3098	>	KeyIterator(ConcurrentHashMap<K,V> map) { super(map); }
3099	>	KeyIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3100	>	super(map, it);
3101	>	}
3102	>	public Spliterator<K> trySplit() {
3103	>	return (baseLimit - baseIndex <= 1) ? null :
3104	>	new KeyIterator<K,V>(map, this);
3105	>	}
3106	>	public final K next() {
3107	>	K k;
3108	>	if ((k = (nextVal == null) ? advanceKey() : nextKey) == null)
3109		throw new NoSuchElementException();
3110	<	lastReturned = e; // cannot assign until after null check
3111	<	if ((nextEntry = e.next) == null)
1261	<	advance();
1262	<	return e;
3110	>	nextVal = null;
3111	>	return k;
3112		}
3113
3114	<	public final boolean hasNext() { return nextEntry != null; }
1266	<	public final boolean hasMoreElements() { return nextEntry != null; }
3114	>	public final K nextElement() { return next(); }
3115
3116	<	public final void remove() {
3117	<	if (lastReturned == null)
3118	<	throw new IllegalStateException();
3119	<	ConcurrentHashMap.this.remove(lastReturned.key);
3120	<	lastReturned = null;
3116	>	public Iterator<K> iterator() { return this; }
3117	>
3118	>	public void forEachRemaining(Consumer<? super K> action) {
3119	>	forEachKey(action);
3120	>	}
3121	>
3122	>	public boolean tryAdvance(Consumer<? super K> block) {
3123	>	if (block == null) throw new NullPointerException();
3124	>	K k;
3125	>	if ((k = advanceKey()) == null)
3126	>	return false;
3127	>	block.accept(k);
3128	>	return true;
3129	>	}
3130	>
3131	>	public int characteristics() {
3132	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3133	>	Spliterator.NONNULL;
3134		}
3135	+
3136		}
3137
3138	<	final class KeyIterator
3139	<	extends HashIterator
3140	<	implements Iterator<K>, Enumeration<K>
3141	<	{
3142	<	public final K next()        { return super.nextEntry().key; }
3143	<	public final K nextElement() { return super.nextEntry().key; }
3138	>	@SuppressWarnings("serial") static final class ValueIterator<K,V>
3139	>	extends Traverser<K,V,Object>
3140	>	implements Spliterator<V>, Iterator<V>, Enumeration<V> {
3141	>	ValueIterator(ConcurrentHashMap<K,V> map) { super(map); }
3142	>	ValueIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3143	>	super(map, it);
3144	>	}
3145	>	public Spliterator<V> trySplit() {
3146	>	return (baseLimit - baseIndex <= 1) ? null :
3147	>	new ValueIterator<K,V>(map, this);
3148	>	}
3149	>
3150	>	public final V next() {
3151	>	V v;
3152	>	if ((v = nextVal) == null && (v = advanceValue()) == null)
3153	>	throw new NoSuchElementException();
3154	>	nextVal = null;
3155	>	return v;
3156	>	}
3157	>
3158	>	public final V nextElement() { return next(); }
3159	>
3160	>	public Iterator<V> iterator() { return this; }
3161	>
3162	>	public void forEachRemaining(Consumer<? super V> action) {
3163	>	forEachValue(action);
3164	>	}
3165	>
3166	>	public boolean tryAdvance(Consumer<? super V> block) {
3167	>	V v;
3168	>	if (block == null) throw new NullPointerException();
3169	>	if ((v = advanceValue()) == null)
3170	>	return false;
3171	>	block.accept(v);
3172	>	return true;
3173	>	}
3174	>
3175	>	public int characteristics() {
3176	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3177	>	}
3178		}
3179
3180	<	final class ValueIterator
3181	<	extends HashIterator
3182	<	implements Iterator<V>, Enumeration<V>
3183	<	{
3184	<	public final V next()        { return super.nextEntry().value; }
3185	<	public final V nextElement() { return super.nextEntry().value; }
3180	>	@SuppressWarnings("serial") static final class EntryIterator<K,V>
3181	>	extends Traverser<K,V,Object>
3182	>	implements Spliterator<Map.Entry<K,V>>, Iterator<Map.Entry<K,V>> {
3183	>	EntryIterator(ConcurrentHashMap<K,V> map) { super(map); }
3184	>	EntryIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3185	>	super(map, it);
3186	>	}
3187	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3188	>	return (baseLimit - baseIndex <= 1) ? null :
3189	>	new EntryIterator<K,V>(map, this);
3190	>	}
3191	>
3192	>	public final Map.Entry<K,V> next() {
3193	>	V v;
3194	>	if ((v = nextVal) == null && (v = advanceValue()) == null)
3195	>	throw new NoSuchElementException();
3196	>	K k = nextKey;
3197	>	nextVal = null;
3198	>	return new MapEntry<K,V>(k, v, map);
3199	>	}
3200	>
3201	>	public Iterator<Map.Entry<K,V>> iterator() { return this; }
3202	>
3203	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3204	>	if (action == null) throw new NullPointerException();
3205	>	V v;
3206	>	while ((v = advanceValue()) != null)
3207	>	action.accept(entryFor(nextKey, v));
3208	>	}
3209	>
3210	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> block) {
3211	>	V v;
3212	>	if (block == null) throw new NullPointerException();
3213	>	if ((v = advanceValue()) == null)
3214	>	return false;
3215	>	block.accept(entryFor(nextKey, v));
3216	>	return true;
3217	>	}
3218	>
3219	>	public int characteristics() {
3220	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3221	>	Spliterator.NONNULL;
3222	>	}
3223		}
3224
3225		/**
3226	<	* Custom Entry class used by EntryIterator.next(), that relays
1294	<	* setValue changes to the underlying map.
3226	>	* Exported Entry for iterators
3227		*/
3228	<	final class WriteThroughEntry
3229	<	extends AbstractMap.SimpleEntry<K,V>
3230	<	{
3231	<	WriteThroughEntry(K k, V v) {
3232	<	super(k,v);
3228	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3229	>	final K key; // non-null
3230	>	V val;       // non-null
3231	>	final ConcurrentHashMap<K,V> map;
3232	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3233	>	this.key = key;
3234	>	this.val = val;
3235	>	this.map = map;
3236	>	}
3237	>	public final K getKey()       { return key; }
3238	>	public final V getValue()     { return val; }
3239	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3240	>	public final String toString(){ return key + "=" + val; }
3241	>
3242	>	public final boolean equals(Object o) {
3243	>	Object k, v; Map.Entry<?,?> e;
3244	>	return ((o instanceof Map.Entry) &&
3245	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3246	>	(v = e.getValue()) != null &&
3247	>	(k == key || k.equals(key)) &&
3248	>	(v == val || v.equals(val)));
3249		}
3250
3251		/**
3252		* Sets our entry's value and writes through to the map. The
3253	<	* value to return is somewhat arbitrary here. Since a
3254	<	* WriteThroughEntry does not necessarily track asynchronous
3255	<	* changes, the most recent "previous" value could be
3256	<	* different from what we return (or could even have been
3257	<	* removed in which case the put will re-establish). We do not
1310	<	* and cannot guarantee more.
3253	>	* value to return is somewhat arbitrary here. Since we do not
3254	>	* necessarily track asynchronous changes, the most recent
3255	>	* "previous" value could be different from what we return (or
3256	>	* could even have been removed in which case the put will
3257	>	* re-establish). We do not and cannot guarantee more.
3258		*/
3259	<	public V setValue(V value) {
3259	>	public final V setValue(V value) {
3260		if (value == null) throw new NullPointerException();
3261	<	V v = super.setValue(value);
3262	<	ConcurrentHashMap.this.put(getKey(), value);
3261	>	V v = val;
3262	>	val = value;
3263	>	map.put(key, value);
3264		return v;
3265		}
3266		}
3267
3268	<	final class EntryIterator
3269	<	extends HashIterator
3270	<	implements Iterator<Entry<K,V>>
3271	<	{
3272	<	public Map.Entry<K,V> next() {
3273	<	HashEntry<K,V> e = super.nextEntry();
1326	<	return new WriteThroughEntry(e.key, e.value);
1327	<	}
3268	>	/**
3269	>	* Returns exportable snapshot entry for the given key and value
3270	>	* when write-through can't or shouldn't be used.
3271	>	*/
3272	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3273	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
3274		}
3275
3276	<	final class KeySet extends AbstractSet<K> {
3277	<	public Iterator<K> iterator() {
3278	<	return new KeyIterator();
3276	>	/* ---------------- Serialization Support -------------- */
3277	>
3278	>	/**
3279	>	* Stripped-down version of helper class used in previous version,
3280	>	* declared for the sake of serialization compatibility
3281	>	*/
3282	>	static class Segment<K,V> implements Serializable {
3283	>	private static final long serialVersionUID = 2249069246763182397L;
3284	>	final float loadFactor;
3285	>	Segment(float lf) { this.loadFactor = lf; }
3286	>	}
3287	>
3288	>	/**
3289	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3290	>	* stream (i.e., serializes it).
3291	>	* @param s the stream
3292	>	* @serialData
3293	>	* the key (Object) and value (Object)
3294	>	* for each key-value mapping, followed by a null pair.
3295	>	* The key-value mappings are emitted in no particular order.
3296	>	*/
3297	>	@SuppressWarnings("unchecked") private void writeObject
3298	>	(java.io.ObjectOutputStream s)
3299	>	throws java.io.IOException {
3300	>	if (segments == null) { // for serialization compatibility
3301	>	segments = (Segment<K,V>[])
3302	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3303	>	for (int i = 0; i < segments.length; ++i)
3304	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3305		}
3306	<	public int size() {
3307	<	return ConcurrentHashMap.this.size();
3306	>	s.defaultWriteObject();
3307	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3308	>	V v;
3309	>	while ((v = it.advanceValue()) != null) {
3310	>	s.writeObject(it.nextKey);
3311	>	s.writeObject(v);
3312	>	}
3313	>	s.writeObject(null);
3314	>	s.writeObject(null);
3315	>	segments = null; // throw away
3316	>	}
3317	>
3318	>	/**
3319	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3320	>	* @param s the stream
3321	>	*/
3322	>	@SuppressWarnings("unchecked") private void readObject
3323	>	(java.io.ObjectInputStream s)
3324	>	throws java.io.IOException, ClassNotFoundException {
3325	>	s.defaultReadObject();
3326	>	this.segments = null; // unneeded
3327	>
3328	>	// Create all nodes, then place in table once size is known
3329	>	long size = 0L;
3330	>	Node<V> p = null;
3331	>	for (;;) {
3332	>	K k = (K) s.readObject();
3333	>	V v = (V) s.readObject();
3334	>	if (k != null && v != null) {
3335	>	int h = spread(k.hashCode());
3336	>	p = new Node<V>(h, k, v, p);
3337	>	++size;
3338	>	}
3339	>	else
3340	>	break;
3341		}
3342	<	public boolean isEmpty() {
3343	<	return ConcurrentHashMap.this.isEmpty();
3342	>	if (p != null) {
3343	>	boolean init = false;
3344	>	int n;
3345	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3346	>	n = MAXIMUM_CAPACITY;
3347	>	else {
3348	>	int sz = (int)size;
3349	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3350	>	}
3351	>	int sc = sizeCtl;
3352	>	boolean collide = false;
3353	>	if (n > sc &&
3354	>	U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
3355	>	try {
3356	>	if (table == null) {
3357	>	init = true;
3358	>	@SuppressWarnings("rawtypes") Node[] rt = new Node[n];
3359	>	Node<V>[] tab = (Node<V>[])rt;
3360	>	int mask = n - 1;
3361	>	while (p != null) {
3362	>	int j = p.hash & mask;
3363	>	Node<V> next = p.next;
3364	>	Node<V> q = p.next = tabAt(tab, j);
3365	>	setTabAt(tab, j, p);
3366	>	if (!collide && q != null && q.hash == p.hash)
3367	>	collide = true;
3368	>	p = next;
3369	>	}
3370	>	table = tab;
3371	>	addCount(size, -1);
3372	>	sc = n - (n >>> 2);
3373	>	}
3374	>	} finally {
3375	>	sizeCtl = sc;
3376	>	}
3377	>	if (collide) { // rescan and convert to TreeBins
3378	>	Node<V>[] tab = table;
3379	>	for (int i = 0; i < tab.length; ++i) {
3380	>	int c = 0;
3381	>	for (Node<V> e = tabAt(tab, i); e != null; e = e.next) {
3382	>	if (++c > TREE_THRESHOLD &&
3383	>	(e.key instanceof Comparable)) {
3384	>	replaceWithTreeBin(tab, i, e.key);
3385	>	break;
3386	>	}
3387	>	}
3388	>	}
3389	>	}
3390	>	}
3391	>	if (!init) { // Can only happen if unsafely published.
3392	>	while (p != null) {
3393	>	internalPut((K)p.key, p.val, false);
3394	>	p = p.next;
3395	>	}
3396	>	}
3397		}
3398	<	public boolean contains(Object o) {
3399	<	return ConcurrentHashMap.this.containsKey(o);
3398	>	}
3399	>
3400	>	// -------------------------------------------------------
3401	>
3402	>	// Sequential bulk operations
3403	>
3404	>	/**
3405	>	* Performs the given action for each (key, value).
3406	>	*
3407	>	* @param action the action
3408	>	*/
3409	>	public void forEachSequentially
3410	>	(BiConsumer<? super K, ? super V> action) {
3411	>	if (action == null) throw new NullPointerException();
3412	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3413	>	V v;
3414	>	while ((v = it.advanceValue()) != null)
3415	>	action.accept(it.nextKey, v);
3416	>	}
3417	>
3418	>	/**
3419	>	* Performs the given action for each non-null transformation
3420	>	* of each (key, value).
3421	>	*
3422	>	* @param transformer a function returning the transformation
3423	>	* for an element, or null if there is no transformation (in
3424	>	* which case the action is not applied)
3425	>	* @param action the action
3426	>	*/
3427	>	public <U> void forEachSequentially
3428	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3429	>	Consumer<? super U> action) {
3430	>	if (transformer == null || action == null)
3431	>	throw new NullPointerException();
3432	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3433	>	V v; U u;
3434	>	while ((v = it.advanceValue()) != null) {
3435	>	if ((u = transformer.apply(it.nextKey, v)) != null)
3436	>	action.accept(u);
3437		}
3438	<	public boolean remove(Object o) {
3439	<	return ConcurrentHashMap.this.remove(o) != null;
3438	>	}
3439	>
3440	>	/**
3441	>	* Returns a non-null result from applying the given search
3442	>	* function on each (key, value), or null if none.
3443	>	*
3444	>	* @param searchFunction a function returning a non-null
3445	>	* result on success, else null
3446	>	* @return a non-null result from applying the given search
3447	>	* function on each (key, value), or null if none
3448	>	*/
3449	>	public <U> U searchSequentially
3450	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3451	>	if (searchFunction == null) throw new NullPointerException();
3452	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3453	>	V v; U u;
3454	>	while ((v = it.advanceValue()) != null) {
3455	>	if ((u = searchFunction.apply(it.nextKey, v)) != null)
3456	>	return u;
3457		}
3458	<	public void clear() {
3459	<	ConcurrentHashMap.this.clear();
3458	>	return null;
3459	>	}
3460	>
3461	>	/**
3462	>	* Returns the result of accumulating the given transformation
3463	>	* of all (key, value) pairs using the given reducer to
3464	>	* combine values, or null if none.
3465	>	*
3466	>	* @param transformer a function returning the transformation
3467	>	* for an element, or null if there is no transformation (in
3468	>	* which case it is not combined)
3469	>	* @param reducer a commutative associative combining function
3470	>	* @return the result of accumulating the given transformation
3471	>	* of all (key, value) pairs
3472	>	*/
3473	>	public <U> U reduceSequentially
3474	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3475	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3476	>	if (transformer == null || reducer == null)
3477	>	throw new NullPointerException();
3478	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3479	>	U r = null, u; V v;
3480	>	while ((v = it.advanceValue()) != null) {
3481	>	if ((u = transformer.apply(it.nextKey, v)) != null)
3482	>	r = (r == null) ? u : reducer.apply(r, u);
3483		}
3484	+	return r;
3485	+	}
3486	+
3487	+	/**
3488	+	* Returns the result of accumulating the given transformation
3489	+	* of all (key, value) pairs using the given reducer to
3490	+	* combine values, and the given basis as an identity value.
3491	+	*
3492	+	* @param transformer a function returning the transformation
3493	+	* for an element
3494	+	* @param basis the identity (initial default value) for the reduction
3495	+	* @param reducer a commutative associative combining function
3496	+	* @return the result of accumulating the given transformation
3497	+	* of all (key, value) pairs
3498	+	*/
3499	+	public double reduceToDoubleSequentially
3500	+	(ToDoubleBiFunction<? super K, ? super V> transformer,
3501	+	double basis,
3502	+	DoubleBinaryOperator reducer) {
3503	+	if (transformer == null || reducer == null)
3504	+	throw new NullPointerException();
3505	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3506	+	double r = basis; V v;
3507	+	while ((v = it.advanceValue()) != null)
3508	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(it.nextKey, v));
3509	+	return r;
3510	+	}
3511	+
3512	+	/**
3513	+	* Returns the result of accumulating the given transformation
3514	+	* of all (key, value) pairs using the given reducer to
3515	+	* combine values, and the given basis as an identity value.
3516	+	*
3517	+	* @param transformer a function returning the transformation
3518	+	* for an element
3519	+	* @param basis the identity (initial default value) for the reduction
3520	+	* @param reducer a commutative associative combining function
3521	+	* @return the result of accumulating the given transformation
3522	+	* of all (key, value) pairs
3523	+	*/
3524	+	public long reduceToLongSequentially
3525	+	(ToLongBiFunction<? super K, ? super V> transformer,
3526	+	long basis,
3527	+	LongBinaryOperator reducer) {
3528	+	if (transformer == null || reducer == null)
3529	+	throw new NullPointerException();
3530	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3531	+	long r = basis; V v;
3532	+	while ((v = it.advanceValue()) != null)
3533	+	r = reducer.applyAsLong(r, transformer.applyAsLong(it.nextKey, v));
3534	+	return r;
3535	+	}
3536	+
3537	+	/**
3538	+	* Returns the result of accumulating the given transformation
3539	+	* of all (key, value) pairs using the given reducer to
3540	+	* combine values, and the given basis as an identity value.
3541	+	*
3542	+	* @param transformer a function returning the transformation
3543	+	* for an element
3544	+	* @param basis the identity (initial default value) for the reduction
3545	+	* @param reducer a commutative associative combining function
3546	+	* @return the result of accumulating the given transformation
3547	+	* of all (key, value) pairs
3548	+	*/
3549	+	public int reduceToIntSequentially
3550	+	(ToIntBiFunction<? super K, ? super V> transformer,
3551	+	int basis,
3552	+	IntBinaryOperator reducer) {
3553	+	if (transformer == null || reducer == null)
3554	+	throw new NullPointerException();
3555	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3556	+	int r = basis; V v;
3557	+	while ((v = it.advanceValue()) != null)
3558	+	r = reducer.applyAsInt(r, transformer.applyAsInt(it.nextKey, v));
3559	+	return r;
3560	+	}
3561	+
3562	+	/**
3563	+	* Performs the given action for each key.
3564	+	*
3565	+	* @param action the action
3566	+	*/
3567	+	public void forEachKeySequentially
3568	+	(Consumer<? super K> action) {
3569	+	new Traverser<K,V,Object>(this).forEachKey(action);
3570		}
3571
3572	<	final class Values extends AbstractCollection<V> {
3573	<	public Iterator<V> iterator() {
3574	<	return new ValueIterator();
3572	>	/**
3573	>	* Performs the given action for each non-null transformation
3574	>	* of each key.
3575	>	*
3576	>	* @param transformer a function returning the transformation
3577	>	* for an element, or null if there is no transformation (in
3578	>	* which case the action is not applied)
3579	>	* @param action the action
3580	>	*/
3581	>	public <U> void forEachKeySequentially
3582	>	(Function<? super K, ? extends U> transformer,
3583	>	Consumer<? super U> action) {
3584	>	if (transformer == null || action == null)
3585	>	throw new NullPointerException();
3586	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3587	>	K k; U u;
3588	>	while ((k = it.advanceKey()) != null) {
3589	>	if ((u = transformer.apply(k)) != null)
3590	>	action.accept(u);
3591		}
3592	<	public int size() {
3593	<	return ConcurrentHashMap.this.size();
3592	>	}
3593	>
3594	>	/**
3595	>	* Returns a non-null result from applying the given search
3596	>	* function on each key, or null if none.
3597	>	*
3598	>	* @param searchFunction a function returning a non-null
3599	>	* result on success, else null
3600	>	* @return a non-null result from applying the given search
3601	>	* function on each key, or null if none
3602	>	*/
3603	>	public <U> U searchKeysSequentially
3604	>	(Function<? super K, ? extends U> searchFunction) {
3605	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3606	>	K k; U u;
3607	>	while ((k = it.advanceKey()) != null) {
3608	>	if ((u = searchFunction.apply(k)) != null)
3609	>	return u;
3610		}
3611	<	public boolean isEmpty() {
3612	<	return ConcurrentHashMap.this.isEmpty();
3611	>	return null;
3612	>	}
3613	>
3614	>	/**
3615	>	* Returns the result of accumulating all keys using the given
3616	>	* reducer to combine values, or null if none.
3617	>	*
3618	>	* @param reducer a commutative associative combining function
3619	>	* @return the result of accumulating all keys using the given
3620	>	* reducer to combine values, or null if none
3621	>	*/
3622	>	public K reduceKeysSequentially
3623	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
3624	>	if (reducer == null) throw new NullPointerException();
3625	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3626	>	K u, r = null;
3627	>	while ((u = it.advanceKey()) != null) {
3628	>	r = (r == null) ? u : reducer.apply(r, u);
3629		}
3630	<	public boolean contains(Object o) {
3631	<	return ConcurrentHashMap.this.containsValue(o);
3630	>	return r;
3631	>	}
3632	>
3633	>	/**
3634	>	* Returns the result of accumulating the given transformation
3635	>	* of all keys using the given reducer to combine values, or
3636	>	* null if none.
3637	>	*
3638	>	* @param transformer a function returning the transformation
3639	>	* for an element, or null if there is no transformation (in
3640	>	* which case it is not combined)
3641	>	* @param reducer a commutative associative combining function
3642	>	* @return the result of accumulating the given transformation
3643	>	* of all keys
3644	>	*/
3645	>	public <U> U reduceKeysSequentially
3646	>	(Function<? super K, ? extends U> transformer,
3647	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3648	>	if (transformer == null || reducer == null)
3649	>	throw new NullPointerException();
3650	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3651	>	K k; U r = null, u;
3652	>	while ((k = it.advanceKey()) != null) {
3653	>	if ((u = transformer.apply(k)) != null)
3654	>	r = (r == null) ? u : reducer.apply(r, u);
3655		}
3656	<	public void clear() {
3657	<	ConcurrentHashMap.this.clear();
3656	>	return r;
3657	>	}
3658	>
3659	>	/**
3660	>	* Returns the result of accumulating the given transformation
3661	>	* of all keys using the given reducer to combine values, and
3662	>	* the given basis as an identity value.
3663	>	*
3664	>	* @param transformer a function returning the transformation
3665	>	* for an element
3666	>	* @param basis the identity (initial default value) for the reduction
3667	>	* @param reducer a commutative associative combining function
3668	>	* @return the result of accumulating the given transformation
3669	>	* of all keys
3670	>	*/
3671	>	public double reduceKeysToDoubleSequentially
3672	>	(ToDoubleFunction<? super K> transformer,
3673	>	double basis,
3674	>	DoubleBinaryOperator reducer) {
3675	>	if (transformer == null || reducer == null)
3676	>	throw new NullPointerException();
3677	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3678	>	double r = basis;
3679	>	K k;
3680	>	while ((k = it.advanceKey()) != null)
3681	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(k));
3682	>	return r;
3683	>	}
3684	>
3685	>	/**
3686	>	* Returns the result of accumulating the given transformation
3687	>	* of all keys using the given reducer to combine values, and
3688	>	* the given basis as an identity value.
3689	>	*
3690	>	* @param transformer a function returning the transformation
3691	>	* for an element
3692	>	* @param basis the identity (initial default value) for the reduction
3693	>	* @param reducer a commutative associative combining function
3694	>	* @return the result of accumulating the given transformation
3695	>	* of all keys
3696	>	*/
3697	>	public long reduceKeysToLongSequentially
3698	>	(ToLongFunction<? super K> transformer,
3699	>	long basis,
3700	>	LongBinaryOperator reducer) {
3701	>	if (transformer == null || reducer == null)
3702	>	throw new NullPointerException();
3703	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3704	>	long r = basis;
3705	>	K k;
3706	>	while ((k = it.advanceKey()) != null)
3707	>	r = reducer.applyAsLong(r, transformer.applyAsLong(k));
3708	>	return r;
3709	>	}
3710	>
3711	>	/**
3712	>	* Returns the result of accumulating the given transformation
3713	>	* of all keys using the given reducer to combine values, and
3714	>	* the given basis as an identity value.
3715	>	*
3716	>	* @param transformer a function returning the transformation
3717	>	* for an element
3718	>	* @param basis the identity (initial default value) for the reduction
3719	>	* @param reducer a commutative associative combining function
3720	>	* @return the result of accumulating the given transformation
3721	>	* of all keys
3722	>	*/
3723	>	public int reduceKeysToIntSequentially
3724	>	(ToIntFunction<? super K> transformer,
3725	>	int basis,
3726	>	IntBinaryOperator reducer) {
3727	>	if (transformer == null || reducer == null)
3728	>	throw new NullPointerException();
3729	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3730	>	int r = basis;
3731	>	K k;
3732	>	while ((k = it.advanceKey()) != null)
3733	>	r = reducer.applyAsInt(r, transformer.applyAsInt(k));
3734	>	return r;
3735	>	}
3736	>
3737	>	/**
3738	>	* Performs the given action for each value.
3739	>	*
3740	>	* @param action the action
3741	>	*/
3742	>	public void forEachValueSequentially(Consumer<? super V> action) {
3743	>	new Traverser<K,V,Object>(this).forEachValue(action);
3744	>	}
3745	>
3746	>	/**
3747	>	* Performs the given action for each non-null transformation
3748	>	* of each value.
3749	>	*
3750	>	* @param transformer a function returning the transformation
3751	>	* for an element, or null if there is no transformation (in
3752	>	* which case the action is not applied)
3753	>	* @param action the action
3754	>	*/
3755	>	public <U> void forEachValueSequentially
3756	>	(Function<? super V, ? extends U> transformer,
3757	>	Consumer<? super U> action) {
3758	>	if (transformer == null || action == null)
3759	>	throw new NullPointerException();
3760	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3761	>	V v; U u;
3762	>	while ((v = it.advanceValue()) != null) {
3763	>	if ((u = transformer.apply(v)) != null)
3764	>	action.accept(u);
3765		}
3766		}
3767
3768	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
3769	<	public Iterator<Map.Entry<K,V>> iterator() {
3770	<	return new EntryIterator();
3768	>	/**
3769	>	* Returns a non-null result from applying the given search
3770	>	* function on each value, or null if none.
3771	>	*
3772	>	* @param searchFunction a function returning a non-null
3773	>	* result on success, else null
3774	>	* @return a non-null result from applying the given search
3775	>	* function on each value, or null if none
3776	>	*/
3777	>	public <U> U searchValuesSequentially
3778	>	(Function<? super V, ? extends U> searchFunction) {
3779	>	if (searchFunction == null) throw new NullPointerException();
3780	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3781	>	V v; U u;
3782	>	while ((v = it.advanceValue()) != null) {
3783	>	if ((u = searchFunction.apply(v)) != null)
3784	>	return u;
3785		}
3786	<	public boolean contains(Object o) {
3787	<	if (!(o instanceof Map.Entry))
3788	<	return false;
3789	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3790	<	V v = ConcurrentHashMap.this.get(e.getKey());
3791	<	return v != null && v.equals(e.getValue());
3786	>	return null;
3787	>	}
3788	>
3789	>	/**
3790	>	* Returns the result of accumulating all values using the
3791	>	* given reducer to combine values, or null if none.
3792	>	*
3793	>	* @param reducer a commutative associative combining function
3794	>	* @return the result of accumulating all values
3795	>	*/
3796	>	public V reduceValuesSequentially
3797	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
3798	>	if (reducer == null) throw new NullPointerException();
3799	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3800	>	V r = null; V v;
3801	>	while ((v = it.advanceValue()) != null)
3802	>	r = (r == null) ? v : reducer.apply(r, v);
3803	>	return r;
3804	>	}
3805	>
3806	>	/**
3807	>	* Returns the result of accumulating the given transformation
3808	>	* of all values using the given reducer to combine values, or
3809	>	* null if none.
3810	>	*
3811	>	* @param transformer a function returning the transformation
3812	>	* for an element, or null if there is no transformation (in
3813	>	* which case it is not combined)
3814	>	* @param reducer a commutative associative combining function
3815	>	* @return the result of accumulating the given transformation
3816	>	* of all values
3817	>	*/
3818	>	public <U> U reduceValuesSequentially
3819	>	(Function<? super V, ? extends U> transformer,
3820	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3821	>	if (transformer == null || reducer == null)
3822	>	throw new NullPointerException();
3823	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3824	>	U r = null, u; V v;
3825	>	while ((v = it.advanceValue()) != null) {
3826	>	if ((u = transformer.apply(v)) != null)
3827	>	r = (r == null) ? u : reducer.apply(r, u);
3828		}
3829	<	public boolean remove(Object o) {
3830	<	if (!(o instanceof Map.Entry))
3831	<	return false;
3832	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3833	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
3829	>	return r;
3830	>	}
3831	>
3832	>	/**
3833	>	* Returns the result of accumulating the given transformation
3834	>	* of all values using the given reducer to combine values,
3835	>	* and the given basis as an identity value.
3836	>	*
3837	>	* @param transformer a function returning the transformation
3838	>	* for an element
3839	>	* @param basis the identity (initial default value) for the reduction
3840	>	* @param reducer a commutative associative combining function
3841	>	* @return the result of accumulating the given transformation
3842	>	* of all values
3843	>	*/
3844	>	public double reduceValuesToDoubleSequentially
3845	>	(ToDoubleFunction<? super V> transformer,
3846	>	double basis,
3847	>	DoubleBinaryOperator reducer) {
3848	>	if (transformer == null || reducer == null)
3849	>	throw new NullPointerException();
3850	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3851	>	double r = basis; V v;
3852	>	while ((v = it.advanceValue()) != null)
3853	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
3854	>	return r;
3855	>	}
3856	>
3857	>	/**
3858	>	* Returns the result of accumulating the given transformation
3859	>	* of all values using the given reducer to combine values,
3860	>	* and the given basis as an identity value.
3861	>	*
3862	>	* @param transformer a function returning the transformation
3863	>	* for an element
3864	>	* @param basis the identity (initial default value) for the reduction
3865	>	* @param reducer a commutative associative combining function
3866	>	* @return the result of accumulating the given transformation
3867	>	* of all values
3868	>	*/
3869	>	public long reduceValuesToLongSequentially
3870	>	(ToLongFunction<? super V> transformer,
3871	>	long basis,
3872	>	LongBinaryOperator reducer) {
3873	>	if (transformer == null || reducer == null)
3874	>	throw new NullPointerException();
3875	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3876	>	long r = basis; V v;
3877	>	while ((v = it.advanceValue()) != null)
3878	>	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
3879	>	return r;
3880	>	}
3881	>
3882	>	/**
3883	>	* Returns the result of accumulating the given transformation
3884	>	* of all values using the given reducer to combine values,
3885	>	* and the given basis as an identity value.
3886	>	*
3887	>	* @param transformer a function returning the transformation
3888	>	* for an element
3889	>	* @param basis the identity (initial default value) for the reduction
3890	>	* @param reducer a commutative associative combining function
3891	>	* @return the result of accumulating the given transformation
3892	>	* of all values
3893	>	*/
3894	>	public int reduceValuesToIntSequentially
3895	>	(ToIntFunction<? super V> transformer,
3896	>	int basis,
3897	>	IntBinaryOperator reducer) {
3898	>	if (transformer == null || reducer == null)
3899	>	throw new NullPointerException();
3900	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3901	>	int r = basis; V v;
3902	>	while ((v = it.advanceValue()) != null)
3903	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
3904	>	return r;
3905	>	}
3906	>
3907	>	/**
3908	>	* Performs the given action for each entry.
3909	>	*
3910	>	* @param action the action
3911	>	*/
3912	>	public void forEachEntrySequentially
3913	>	(Consumer<? super Map.Entry<K,V>> action) {
3914	>	if (action == null) throw new NullPointerException();
3915	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3916	>	V v;
3917	>	while ((v = it.advanceValue()) != null)
3918	>	action.accept(entryFor(it.nextKey, v));
3919	>	}
3920	>
3921	>	/**
3922	>	* Performs the given action for each non-null transformation
3923	>	* of each entry.
3924	>	*
3925	>	* @param transformer a function returning the transformation
3926	>	* for an element, or null if there is no transformation (in
3927	>	* which case the action is not applied)
3928	>	* @param action the action
3929	>	*/
3930	>	public <U> void forEachEntrySequentially
3931	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3932	>	Consumer<? super U> action) {
3933	>	if (transformer == null || action == null)
3934	>	throw new NullPointerException();
3935	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3936	>	V v; U u;
3937	>	while ((v = it.advanceValue()) != null) {
3938	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
3939	>	action.accept(u);
3940		}
3941	<	public int size() {
3942	<	return ConcurrentHashMap.this.size();
3941	>	}
3942	>
3943	>	/**
3944	>	* Returns a non-null result from applying the given search
3945	>	* function on each entry, or null if none.
3946	>	*
3947	>	* @param searchFunction a function returning a non-null
3948	>	* result on success, else null
3949	>	* @return a non-null result from applying the given search
3950	>	* function on each entry, or null if none
3951	>	*/
3952	>	public <U> U searchEntriesSequentially
3953	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
3954	>	if (searchFunction == null) throw new NullPointerException();
3955	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3956	>	V v; U u;
3957	>	while ((v = it.advanceValue()) != null) {
3958	>	if ((u = searchFunction.apply(entryFor(it.nextKey, v))) != null)
3959	>	return u;
3960		}
3961	<	public boolean isEmpty() {
3962	<	return ConcurrentHashMap.this.isEmpty();
3961	>	return null;
3962	>	}
3963	>
3964	>	/**
3965	>	* Returns the result of accumulating all entries using the
3966	>	* given reducer to combine values, or null if none.
3967	>	*
3968	>	* @param reducer a commutative associative combining function
3969	>	* @return the result of accumulating all entries
3970	>	*/
3971	>	public Map.Entry<K,V> reduceEntriesSequentially
3972	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3973	>	if (reducer == null) throw new NullPointerException();
3974	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3975	>	Map.Entry<K,V> r = null; V v;
3976	>	while ((v = it.advanceValue()) != null) {
3977	>	Map.Entry<K,V> u = entryFor(it.nextKey, v);
3978	>	r = (r == null) ? u : reducer.apply(r, u);
3979		}
3980	<	public void clear() {
3981	<	ConcurrentHashMap.this.clear();
3980	>	return r;
3981	>	}
3982	>
3983	>	/**
3984	>	* Returns the result of accumulating the given transformation
3985	>	* of all entries using the given reducer to combine values,
3986	>	* or null if none.
3987	>	*
3988	>	* @param transformer a function returning the transformation
3989	>	* for an element, or null if there is no transformation (in
3990	>	* which case it is not combined)
3991	>	* @param reducer a commutative associative combining function
3992	>	* @return the result of accumulating the given transformation
3993	>	* of all entries
3994	>	*/
3995	>	public <U> U reduceEntriesSequentially
3996	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3997	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3998	>	if (transformer == null || reducer == null)
3999	>	throw new NullPointerException();
4000	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4001	>	U r = null, u; V v;
4002	>	while ((v = it.advanceValue()) != null) {
4003	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
4004	>	r = (r == null) ? u : reducer.apply(r, u);
4005		}
4006	+	return r;
4007		}
4008
4009	<	/* ---------------- Serialization Support -------------- */
4009	>	/**
4010	>	* Returns the result of accumulating the given transformation
4011	>	* of all entries using the given reducer to combine values,
4012	>	* and the given basis as an identity value.
4013	>	*
4014	>	* @param transformer a function returning the transformation
4015	>	* for an element
4016	>	* @param basis the identity (initial default value) for the reduction
4017	>	* @param reducer a commutative associative combining function
4018	>	* @return the result of accumulating the given transformation
4019	>	* of all entries
4020	>	*/
4021	>	public double reduceEntriesToDoubleSequentially
4022	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
4023	>	double basis,
4024	>	DoubleBinaryOperator reducer) {
4025	>	if (transformer == null || reducer == null)
4026	>	throw new NullPointerException();
4027	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4028	>	double r = basis; V v;
4029	>	while ((v = it.advanceValue()) != null)
4030	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(it.nextKey, v)));
4031	>	return r;
4032	>	}
4033
4034		/**
4035	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4036	<	* stream (i.e., serializes it).
4037	<	* @param s the stream
4038	<	* @serialData
4039	<	* the key (Object) and value (Object)
4040	<	* for each key-value mapping, followed by a null pair.
4041	<	* The key-value mappings are emitted in no particular order.
4035	>	* Returns the result of accumulating the given transformation
4036	>	* of all entries using the given reducer to combine values,
4037	>	* and the given basis as an identity value.
4038	>	*
4039	>	* @param transformer a function returning the transformation
4040	>	* for an element
4041	>	* @param basis the identity (initial default value) for the reduction
4042	>	* @param reducer a commutative associative combining function
4043	>	* @return the result of accumulating the given transformation
4044	>	* of all entries
4045	>	*/
4046	>	public long reduceEntriesToLongSequentially
4047	>	(ToLongFunction<Map.Entry<K,V>> transformer,
4048	>	long basis,
4049	>	LongBinaryOperator reducer) {
4050	>	if (transformer == null || reducer == null)
4051	>	throw new NullPointerException();
4052	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4053	>	long r = basis; V v;
4054	>	while ((v = it.advanceValue()) != null)
4055	>	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(it.nextKey, v)));
4056	>	return r;
4057	>	}
4058	>
4059	>	/**
4060	>	* Returns the result of accumulating the given transformation
4061	>	* of all entries using the given reducer to combine values,
4062	>	* and the given basis as an identity value.
4063	>	*
4064	>	* @param transformer a function returning the transformation
4065	>	* for an element
4066	>	* @param basis the identity (initial default value) for the reduction
4067	>	* @param reducer a commutative associative combining function
4068	>	* @return the result of accumulating the given transformation
4069	>	* of all entries
4070	>	*/
4071	>	public int reduceEntriesToIntSequentially
4072	>	(ToIntFunction<Map.Entry<K,V>> transformer,
4073	>	int basis,
4074	>	IntBinaryOperator reducer) {
4075	>	if (transformer == null || reducer == null)
4076	>	throw new NullPointerException();
4077	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4078	>	int r = basis; V v;
4079	>	while ((v = it.advanceValue()) != null)
4080	>	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(it.nextKey, v)));
4081	>	return r;
4082	>	}
4083	>
4084	>	// Parallel bulk operations
4085	>
4086	>	/**
4087	>	* Performs the given action for each (key, value).
4088	>	*
4089	>	* @param action the action
4090		*/
4091	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4092	<	// force all segments for serialization compatibility
4093	<	for (int k = 0; k < segments.length; ++k)
4094	<	ensureSegment(k);
1412	<	s.defaultWriteObject();
4091	>	public void forEachInParallel(BiConsumer<? super K,? super V> action) {
4092	>	ForkJoinTasks.forEach
4093	>	(this, action).invoke();
4094	>	}
4095
4096	<	final Segment<K,V>[] segments = this.segments;
4097	<	for (int k = 0; k < segments.length; ++k) {
4098	<	Segment<K,V> seg = segmentAt(segments, k);
4099	<	seg.lock();
4100	<	try {
4101	<	HashEntry<K,V>[] tab = seg.table;
4102	<	for (int i = 0; i < tab.length; ++i) {
4103	<	HashEntry<K,V> e;
4104	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4105	<	s.writeObject(e.key);
4106	<	s.writeObject(e.value);
4096	>	/**
4097	>	* Performs the given action for each non-null transformation
4098	>	* of each (key, value).
4099	>	*
4100	>	* @param transformer a function returning the transformation
4101	>	* for an element, or null if there is no transformation (in
4102	>	* which case the action is not applied)
4103	>	* @param action the action
4104	>	*/
4105	>	public <U> void forEachInParallel
4106	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
4107	>	Consumer<? super U> action) {
4108	>	ForkJoinTasks.forEach
4109	>	(this, transformer, action).invoke();
4110	>	}
4111	>
4112	>	/**
4113	>	* Returns a non-null result from applying the given search
4114	>	* function on each (key, value), or null if none.  Upon
4115	>	* success, further element processing is suppressed and the
4116	>	* results of any other parallel invocations of the search
4117	>	* function are ignored.
4118	>	*
4119	>	* @param searchFunction a function returning a non-null
4120	>	* result on success, else null
4121	>	* @return a non-null result from applying the given search
4122	>	* function on each (key, value), or null if none
4123	>	*/
4124	>	public <U> U searchInParallel
4125	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
4126	>	return ForkJoinTasks.search
4127	>	(this, searchFunction).invoke();
4128	>	}
4129	>
4130	>	/**
4131	>	* Returns the result of accumulating the given transformation
4132	>	* of all (key, value) pairs using the given reducer to
4133	>	* combine values, or null if none.
4134	>	*
4135	>	* @param transformer a function returning the transformation
4136	>	* for an element, or null if there is no transformation (in
4137	>	* which case it is not combined)
4138	>	* @param reducer a commutative associative combining function
4139	>	* @return the result of accumulating the given transformation
4140	>	* of all (key, value) pairs
4141	>	*/
4142	>	public <U> U reduceInParallel
4143	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
4144	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4145	>	return ForkJoinTasks.reduce
4146	>	(this, transformer, reducer).invoke();
4147	>	}
4148	>
4149	>	/**
4150	>	* Returns the result of accumulating the given transformation
4151	>	* of all (key, value) pairs using the given reducer to
4152	>	* combine values, and the given basis as an identity value.
4153	>	*
4154	>	* @param transformer a function returning the transformation
4155	>	* for an element
4156	>	* @param basis the identity (initial default value) for the reduction
4157	>	* @param reducer a commutative associative combining function
4158	>	* @return the result of accumulating the given transformation
4159	>	* of all (key, value) pairs
4160	>	*/
4161	>	public double reduceToDoubleInParallel
4162	>	(ToDoubleBiFunction<? super K, ? super V> transformer,
4163	>	double basis,
4164	>	DoubleBinaryOperator reducer) {
4165	>	return ForkJoinTasks.reduceToDouble
4166	>	(this, transformer, basis, reducer).invoke();
4167	>	}
4168	>
4169	>	/**
4170	>	* Returns the result of accumulating the given transformation
4171	>	* of all (key, value) pairs using the given reducer to
4172	>	* combine values, and the given basis as an identity value.
4173	>	*
4174	>	* @param transformer a function returning the transformation
4175	>	* for an element
4176	>	* @param basis the identity (initial default value) for the reduction
4177	>	* @param reducer a commutative associative combining function
4178	>	* @return the result of accumulating the given transformation
4179	>	* of all (key, value) pairs
4180	>	*/
4181	>	public long reduceToLongInParallel
4182	>	(ToLongBiFunction<? super K, ? super V> transformer,
4183	>	long basis,
4184	>	LongBinaryOperator reducer) {
4185	>	return ForkJoinTasks.reduceToLong
4186	>	(this, transformer, basis, reducer).invoke();
4187	>	}
4188	>
4189	>	/**
4190	>	* Returns the result of accumulating the given transformation
4191	>	* of all (key, value) pairs using the given reducer to
4192	>	* combine values, and the given basis as an identity value.
4193	>	*
4194	>	* @param transformer a function returning the transformation
4195	>	* for an element
4196	>	* @param basis the identity (initial default value) for the reduction
4197	>	* @param reducer a commutative associative combining function
4198	>	* @return the result of accumulating the given transformation
4199	>	* of all (key, value) pairs
4200	>	*/
4201	>	public int reduceToIntInParallel
4202	>	(ToIntBiFunction<? super K, ? super V> transformer,
4203	>	int basis,
4204	>	IntBinaryOperator reducer) {
4205	>	return ForkJoinTasks.reduceToInt
4206	>	(this, transformer, basis, reducer).invoke();
4207	>	}
4208	>
4209	>	/**
4210	>	* Performs the given action for each key.
4211	>	*
4212	>	* @param action the action
4213	>	*/
4214	>	public void forEachKeyInParallel(Consumer<? super K> action) {
4215	>	ForkJoinTasks.forEachKey
4216	>	(this, action).invoke();
4217	>	}
4218	>
4219	>	/**
4220	>	* Performs the given action for each non-null transformation
4221	>	* of each key.
4222	>	*
4223	>	* @param transformer a function returning the transformation
4224	>	* for an element, or null if there is no transformation (in
4225	>	* which case the action is not applied)
4226	>	* @param action the action
4227	>	*/
4228	>	public <U> void forEachKeyInParallel
4229	>	(Function<? super K, ? extends U> transformer,
4230	>	Consumer<? super U> action) {
4231	>	ForkJoinTasks.forEachKey
4232	>	(this, transformer, action).invoke();
4233	>	}
4234	>
4235	>	/**
4236	>	* Returns a non-null result from applying the given search
4237	>	* function on each key, or null if none. Upon success,
4238	>	* further element processing is suppressed and the results of
4239	>	* any other parallel invocations of the search function are
4240	>	* ignored.
4241	>	*
4242	>	* @param searchFunction a function returning a non-null
4243	>	* result on success, else null
4244	>	* @return a non-null result from applying the given search
4245	>	* function on each key, or null if none
4246	>	*/
4247	>	public <U> U searchKeysInParallel
4248	>	(Function<? super K, ? extends U> searchFunction) {
4249	>	return ForkJoinTasks.searchKeys
4250	>	(this, searchFunction).invoke();
4251	>	}
4252	>
4253	>	/**
4254	>	* Returns the result of accumulating all keys using the given
4255	>	* reducer to combine values, or null if none.
4256	>	*
4257	>	* @param reducer a commutative associative combining function
4258	>	* @return the result of accumulating all keys using the given
4259	>	* reducer to combine values, or null if none
4260	>	*/
4261	>	public K reduceKeysInParallel
4262	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
4263	>	return ForkJoinTasks.reduceKeys
4264	>	(this, reducer).invoke();
4265	>	}
4266	>
4267	>	/**
4268	>	* Returns the result of accumulating the given transformation
4269	>	* of all keys using the given reducer to combine values, or
4270	>	* null if none.
4271	>	*
4272	>	* @param transformer a function returning the transformation
4273	>	* for an element, or null if there is no transformation (in
4274	>	* which case it is not combined)
4275	>	* @param reducer a commutative associative combining function
4276	>	* @return the result of accumulating the given transformation
4277	>	* of all keys
4278	>	*/
4279	>	public <U> U reduceKeysInParallel
4280	>	(Function<? super K, ? extends U> transformer,
4281	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4282	>	return ForkJoinTasks.reduceKeys
4283	>	(this, transformer, reducer).invoke();
4284	>	}
4285	>
4286	>	/**
4287	>	* Returns the result of accumulating the given transformation
4288	>	* of all keys using the given reducer to combine values, and
4289	>	* the given basis as an identity value.
4290	>	*
4291	>	* @param transformer a function returning the transformation
4292	>	* for an element
4293	>	* @param basis the identity (initial default value) for the reduction
4294	>	* @param reducer a commutative associative combining function
4295	>	* @return the result of accumulating the given transformation
4296	>	* of all keys
4297	>	*/
4298	>	public double reduceKeysToDoubleInParallel
4299	>	(ToDoubleFunction<? super K> transformer,
4300	>	double basis,
4301	>	DoubleBinaryOperator reducer) {
4302	>	return ForkJoinTasks.reduceKeysToDouble
4303	>	(this, transformer, basis, reducer).invoke();
4304	>	}
4305	>
4306	>	/**
4307	>	* Returns the result of accumulating the given transformation
4308	>	* of all keys using the given reducer to combine values, and
4309	>	* the given basis as an identity value.
4310	>	*
4311	>	* @param transformer a function returning the transformation
4312	>	* for an element
4313	>	* @param basis the identity (initial default value) for the reduction
4314	>	* @param reducer a commutative associative combining function
4315	>	* @return the result of accumulating the given transformation
4316	>	* of all keys
4317	>	*/
4318	>	public long reduceKeysToLongInParallel
4319	>	(ToLongFunction<? super K> transformer,
4320	>	long basis,
4321	>	LongBinaryOperator reducer) {
4322	>	return ForkJoinTasks.reduceKeysToLong
4323	>	(this, transformer, basis, reducer).invoke();
4324	>	}
4325	>
4326	>	/**
4327	>	* Returns the result of accumulating the given transformation
4328	>	* of all keys using the given reducer to combine values, and
4329	>	* the given basis as an identity value.
4330	>	*
4331	>	* @param transformer a function returning the transformation
4332	>	* for an element
4333	>	* @param basis the identity (initial default value) for the reduction
4334	>	* @param reducer a commutative associative combining function
4335	>	* @return the result of accumulating the given transformation
4336	>	* of all keys
4337	>	*/
4338	>	public int reduceKeysToIntInParallel
4339	>	(ToIntFunction<? super K> transformer,
4340	>	int basis,
4341	>	IntBinaryOperator reducer) {
4342	>	return ForkJoinTasks.reduceKeysToInt
4343	>	(this, transformer, basis, reducer).invoke();
4344	>	}
4345	>
4346	>	/**
4347	>	* Performs the given action for each value.
4348	>	*
4349	>	* @param action the action
4350	>	*/
4351	>	public void forEachValueInParallel(Consumer<? super V> action) {
4352	>	ForkJoinTasks.forEachValue
4353	>	(this, action).invoke();
4354	>	}
4355	>
4356	>	/**
4357	>	* Performs the given action for each non-null transformation
4358	>	* of each value.
4359	>	*
4360	>	* @param transformer a function returning the transformation
4361	>	* for an element, or null if there is no transformation (in
4362	>	* which case the action is not applied)
4363	>	* @param action the action
4364	>	*/
4365	>	public <U> void forEachValueInParallel
4366	>	(Function<? super V, ? extends U> transformer,
4367	>	Consumer<? super U> action) {
4368	>	ForkJoinTasks.forEachValue
4369	>	(this, transformer, action).invoke();
4370	>	}
4371	>
4372	>	/**
4373	>	* Returns a non-null result from applying the given search
4374	>	* function on each value, or null if none.  Upon success,
4375	>	* further element processing is suppressed and the results of
4376	>	* any other parallel invocations of the search function are
4377	>	* ignored.
4378	>	*
4379	>	* @param searchFunction a function returning a non-null
4380	>	* result on success, else null
4381	>	* @return a non-null result from applying the given search
4382	>	* function on each value, or null if none
4383	>	*/
4384	>	public <U> U searchValuesInParallel
4385	>	(Function<? super V, ? extends U> searchFunction) {
4386	>	return ForkJoinTasks.searchValues
4387	>	(this, searchFunction).invoke();
4388	>	}
4389	>
4390	>	/**
4391	>	* Returns the result of accumulating all values using the
4392	>	* given reducer to combine values, or null if none.
4393	>	*
4394	>	* @param reducer a commutative associative combining function
4395	>	* @return the result of accumulating all values
4396	>	*/
4397	>	public V reduceValuesInParallel
4398	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
4399	>	return ForkJoinTasks.reduceValues
4400	>	(this, reducer).invoke();
4401	>	}
4402	>
4403	>	/**
4404	>	* Returns the result of accumulating the given transformation
4405	>	* of all values using the given reducer to combine values, or
4406	>	* null if none.
4407	>	*
4408	>	* @param transformer a function returning the transformation
4409	>	* for an element, or null if there is no transformation (in
4410	>	* which case it is not combined)
4411	>	* @param reducer a commutative associative combining function
4412	>	* @return the result of accumulating the given transformation
4413	>	* of all values
4414	>	*/
4415	>	public <U> U reduceValuesInParallel
4416	>	(Function<? super V, ? extends U> transformer,
4417	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4418	>	return ForkJoinTasks.reduceValues
4419	>	(this, transformer, reducer).invoke();
4420	>	}
4421	>
4422	>	/**
4423	>	* Returns the result of accumulating the given transformation
4424	>	* of all values using the given reducer to combine values,
4425	>	* and the given basis as an identity value.
4426	>	*
4427	>	* @param transformer a function returning the transformation
4428	>	* for an element
4429	>	* @param basis the identity (initial default value) for the reduction
4430	>	* @param reducer a commutative associative combining function
4431	>	* @return the result of accumulating the given transformation
4432	>	* of all values
4433	>	*/
4434	>	public double reduceValuesToDoubleInParallel
4435	>	(ToDoubleFunction<? super V> transformer,
4436	>	double basis,
4437	>	DoubleBinaryOperator reducer) {
4438	>	return ForkJoinTasks.reduceValuesToDouble
4439	>	(this, transformer, basis, reducer).invoke();
4440	>	}
4441	>
4442	>	/**
4443	>	* Returns the result of accumulating the given transformation
4444	>	* of all values using the given reducer to combine values,
4445	>	* and the given basis as an identity value.
4446	>	*
4447	>	* @param transformer a function returning the transformation
4448	>	* for an element
4449	>	* @param basis the identity (initial default value) for the reduction
4450	>	* @param reducer a commutative associative combining function
4451	>	* @return the result of accumulating the given transformation
4452	>	* of all values
4453	>	*/
4454	>	public long reduceValuesToLongInParallel
4455	>	(ToLongFunction<? super V> transformer,
4456	>	long basis,
4457	>	LongBinaryOperator reducer) {
4458	>	return ForkJoinTasks.reduceValuesToLong
4459	>	(this, transformer, basis, reducer).invoke();
4460	>	}
4461	>
4462	>	/**
4463	>	* Returns the result of accumulating the given transformation
4464	>	* of all values using the given reducer to combine values,
4465	>	* and the given basis as an identity value.
4466	>	*
4467	>	* @param transformer a function returning the transformation
4468	>	* for an element
4469	>	* @param basis the identity (initial default value) for the reduction
4470	>	* @param reducer a commutative associative combining function
4471	>	* @return the result of accumulating the given transformation
4472	>	* of all values
4473	>	*/
4474	>	public int reduceValuesToIntInParallel
4475	>	(ToIntFunction<? super V> transformer,
4476	>	int basis,
4477	>	IntBinaryOperator reducer) {
4478	>	return ForkJoinTasks.reduceValuesToInt
4479	>	(this, transformer, basis, reducer).invoke();
4480	>	}
4481	>
4482	>	/**
4483	>	* Performs the given action for each entry.
4484	>	*
4485	>	* @param action the action
4486	>	*/
4487	>	public void forEachEntryInParallel(Consumer<? super Map.Entry<K,V>> action) {
4488	>	ForkJoinTasks.forEachEntry
4489	>	(this, action).invoke();
4490	>	}
4491	>
4492	>	/**
4493	>	* Performs the given action for each non-null transformation
4494	>	* of each entry.
4495	>	*
4496	>	* @param transformer a function returning the transformation
4497	>	* for an element, or null if there is no transformation (in
4498	>	* which case the action is not applied)
4499	>	* @param action the action
4500	>	*/
4501	>	public <U> void forEachEntryInParallel
4502	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4503	>	Consumer<? super U> action) {
4504	>	ForkJoinTasks.forEachEntry
4505	>	(this, transformer, action).invoke();
4506	>	}
4507	>
4508	>	/**
4509	>	* Returns a non-null result from applying the given search
4510	>	* function on each entry, or null if none.  Upon success,
4511	>	* further element processing is suppressed and the results of
4512	>	* any other parallel invocations of the search function are
4513	>	* ignored.
4514	>	*
4515	>	* @param searchFunction a function returning a non-null
4516	>	* result on success, else null
4517	>	* @return a non-null result from applying the given search
4518	>	* function on each entry, or null if none
4519	>	*/
4520	>	public <U> U searchEntriesInParallel
4521	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4522	>	return ForkJoinTasks.searchEntries
4523	>	(this, searchFunction).invoke();
4524	>	}
4525	>
4526	>	/**
4527	>	* Returns the result of accumulating all entries using the
4528	>	* given reducer to combine values, or null if none.
4529	>	*
4530	>	* @param reducer a commutative associative combining function
4531	>	* @return the result of accumulating all entries
4532	>	*/
4533	>	public Map.Entry<K,V> reduceEntriesInParallel
4534	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4535	>	return ForkJoinTasks.reduceEntries
4536	>	(this, reducer).invoke();
4537	>	}
4538	>
4539	>	/**
4540	>	* Returns the result of accumulating the given transformation
4541	>	* of all entries using the given reducer to combine values,
4542	>	* or null if none.
4543	>	*
4544	>	* @param transformer a function returning the transformation
4545	>	* for an element, or null if there is no transformation (in
4546	>	* which case it is not combined)
4547	>	* @param reducer a commutative associative combining function
4548	>	* @return the result of accumulating the given transformation
4549	>	* of all entries
4550	>	*/
4551	>	public <U> U reduceEntriesInParallel
4552	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4553	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4554	>	return ForkJoinTasks.reduceEntries
4555	>	(this, transformer, reducer).invoke();
4556	>	}
4557	>
4558	>	/**
4559	>	* Returns the result of accumulating the given transformation
4560	>	* of all entries using the given reducer to combine values,
4561	>	* and the given basis as an identity value.
4562	>	*
4563	>	* @param transformer a function returning the transformation
4564	>	* for an element
4565	>	* @param basis the identity (initial default value) for the reduction
4566	>	* @param reducer a commutative associative combining function
4567	>	* @return the result of accumulating the given transformation
4568	>	* of all entries
4569	>	*/
4570	>	public double reduceEntriesToDoubleInParallel
4571	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
4572	>	double basis,
4573	>	DoubleBinaryOperator reducer) {
4574	>	return ForkJoinTasks.reduceEntriesToDouble
4575	>	(this, transformer, basis, reducer).invoke();
4576	>	}
4577	>
4578	>	/**
4579	>	* Returns the result of accumulating the given transformation
4580	>	* of all entries using the given reducer to combine values,
4581	>	* and the given basis as an identity value.
4582	>	*
4583	>	* @param transformer a function returning the transformation
4584	>	* for an element
4585	>	* @param basis the identity (initial default value) for the reduction
4586	>	* @param reducer a commutative associative combining function
4587	>	* @return the result of accumulating the given transformation
4588	>	* of all entries
4589	>	*/
4590	>	public long reduceEntriesToLongInParallel
4591	>	(ToLongFunction<Map.Entry<K,V>> transformer,
4592	>	long basis,
4593	>	LongBinaryOperator reducer) {
4594	>	return ForkJoinTasks.reduceEntriesToLong
4595	>	(this, transformer, basis, reducer).invoke();
4596	>	}
4597	>
4598	>	/**
4599	>	* Returns the result of accumulating the given transformation
4600	>	* of all entries using the given reducer to combine values,
4601	>	* and the given basis as an identity value.
4602	>	*
4603	>	* @param transformer a function returning the transformation
4604	>	* for an element
4605	>	* @param basis the identity (initial default value) for the reduction
4606	>	* @param reducer a commutative associative combining function
4607	>	* @return the result of accumulating the given transformation
4608	>	* of all entries
4609	>	*/
4610	>	public int reduceEntriesToIntInParallel
4611	>	(ToIntFunction<Map.Entry<K,V>> transformer,
4612	>	int basis,
4613	>	IntBinaryOperator reducer) {
4614	>	return ForkJoinTasks.reduceEntriesToInt
4615	>	(this, transformer, basis, reducer).invoke();
4616	>	}
4617	>
4618	>
4619	>	/* ----------------Views -------------- */
4620	>
4621	>	/**
4622	>	* Base class for views.
4623	>	*/
4624	>	abstract static class CHMCollectionView<K,V,E>
4625	>	implements Collection<E>, java.io.Serializable {
4626	>	private static final long serialVersionUID = 7249069246763182397L;
4627	>	final ConcurrentHashMap<K,V> map;
4628	>	CHMCollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4629	>
4630	>	/**
4631	>	* Returns the map backing this view.
4632	>	*
4633	>	* @return the map backing this view
4634	>	*/
4635	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4636	>
4637	>	/**
4638	>	* Removes all of the elements from this view, by removing all
4639	>	* the mappings from the map backing this view.
4640	>	*/
4641	>	public final void clear()      { map.clear(); }
4642	>	public final int size()        { return map.size(); }
4643	>	public final boolean isEmpty() { return map.isEmpty(); }
4644	>
4645	>	// implementations below rely on concrete classes supplying these
4646	>	// abstract methods
4647	>	/**
4648	>	* Returns a "weakly consistent" iterator that will never
4649	>	* throw {@link ConcurrentModificationException}, and
4650	>	* guarantees to traverse elements as they existed upon
4651	>	* construction of the iterator, and may (but is not
4652	>	* guaranteed to) reflect any modifications subsequent to
4653	>	* construction.
4654	>	*/
4655	>	public abstract Iterator<E> iterator();
4656	>	public abstract boolean contains(Object o);
4657	>	public abstract boolean remove(Object o);
4658	>
4659	>	private static final String oomeMsg = "Required array size too large";
4660	>
4661	>	public final Object[] toArray() {
4662	>	long sz = map.mappingCount();
4663	>	if (sz > MAX_ARRAY_SIZE)
4664	>	throw new OutOfMemoryError(oomeMsg);
4665	>	int n = (int)sz;
4666	>	Object[] r = new Object[n];
4667	>	int i = 0;
4668	>	for (E e : this) {
4669	>	if (i == n) {
4670	>	if (n >= MAX_ARRAY_SIZE)
4671	>	throw new OutOfMemoryError(oomeMsg);
4672	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4673	>	n = MAX_ARRAY_SIZE;
4674	>	else
4675	>	n += (n >>> 1) + 1;
4676	>	r = Arrays.copyOf(r, n);
4677	>	}
4678	>	r[i++] = e;
4679	>	}
4680	>	return (i == n) ? r : Arrays.copyOf(r, i);
4681	>	}
4682	>
4683	>	@SuppressWarnings("unchecked")
4684	>	public final <T> T[] toArray(T[] a) {
4685	>	long sz = map.mappingCount();
4686	>	if (sz > MAX_ARRAY_SIZE)
4687	>	throw new OutOfMemoryError(oomeMsg);
4688	>	int m = (int)sz;
4689	>	T[] r = (a.length >= m) ? a :
4690	>	(T[])java.lang.reflect.Array
4691	>	.newInstance(a.getClass().getComponentType(), m);
4692	>	int n = r.length;
4693	>	int i = 0;
4694	>	for (E e : this) {
4695	>	if (i == n) {
4696	>	if (n >= MAX_ARRAY_SIZE)
4697	>	throw new OutOfMemoryError(oomeMsg);
4698	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4699	>	n = MAX_ARRAY_SIZE;
4700	>	else
4701	>	n += (n >>> 1) + 1;
4702	>	r = Arrays.copyOf(r, n);
4703	>	}
4704	>	r[i++] = (T)e;
4705	>	}
4706	>	if (a == r && i < n) {
4707	>	r[i] = null; // null-terminate
4708	>	return r;
4709	>	}
4710	>	return (i == n) ? r : Arrays.copyOf(r, i);
4711	>	}
4712	>
4713	>	/**
4714	>	* Returns a string representation of this collection.
4715	>	* The string representation consists of the string representations
4716	>	* of the collection's elements in the order they are returned by
4717	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4718	>	* Adjacent elements are separated by the characters {@code ", "}
4719	>	* (comma and space).  Elements are converted to strings as by
4720	>	* {@link String#valueOf(Object)}.
4721	>	*
4722	>	* @return a string representation of this collection
4723	>	*/
4724	>	public final String toString() {
4725	>	StringBuilder sb = new StringBuilder();
4726	>	sb.append('[');
4727	>	Iterator<E> it = iterator();
4728	>	if (it.hasNext()) {
4729	>	for (;;) {
4730	>	Object e = it.next();
4731	>	sb.append(e == this ? "(this Collection)" : e);
4732	>	if (!it.hasNext())
4733	>	break;
4734	>	sb.append(',').append(' ');
4735	>	}
4736	>	}
4737	>	return sb.append(']').toString();
4738	>	}
4739	>
4740	>	public final boolean containsAll(Collection<?> c) {
4741	>	if (c != this) {
4742	>	for (Object e : c) {
4743	>	if (e == null || !contains(e))
4744	>	return false;
4745	>	}
4746	>	}
4747	>	return true;
4748	>	}
4749	>
4750	>	public final boolean removeAll(Collection<?> c) {
4751	>	boolean modified = false;
4752	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4753	>	if (c.contains(it.next())) {
4754	>	it.remove();
4755	>	modified = true;
4756	>	}
4757	>	}
4758	>	return modified;
4759	>	}
4760	>
4761	>	public final boolean retainAll(Collection<?> c) {
4762	>	boolean modified = false;
4763	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4764	>	if (!c.contains(it.next())) {
4765	>	it.remove();
4766	>	modified = true;
4767	>	}
4768	>	}
4769	>	return modified;
4770	>	}
4771	>
4772	>	}
4773	>
4774	>	abstract static class CHMSetView<K,V,E>
4775	>	extends CHMCollectionView<K,V,E>
4776	>	implements Set<E>, java.io.Serializable {
4777	>	private static final long serialVersionUID = 7249069246763182397L;
4778	>	CHMSetView(ConcurrentHashMap<K,V> map) { super(map); }
4779	>
4780	>	// Implement Set API
4781	>
4782	>	/**
4783	>	* Implements {@link Set#hashCode()}.
4784	>	* @return the hash code value for this set
4785	>	*/
4786	>	public final int hashCode() {
4787	>	int h = 0;
4788	>	for (E e : this)
4789	>	h += e.hashCode();
4790	>	return h;
4791	>	}
4792	>
4793	>	/**
4794	>	* Implements {@link Set#equals(Object)}.
4795	>	* @param o object to be compared for equality with this set
4796	>	* @return {@code true} if the specified object is equal to this set
4797	>	*/
4798	>	public final boolean equals(Object o) {
4799	>	Set<?> c;
4800	>	return ((o instanceof Set) &&
4801	>	((c = (Set<?>)o) == this ||
4802	>	(containsAll(c) && c.containsAll(this))));
4803	>	}
4804	>	}
4805	>
4806	>	/**
4807	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4808	>	* which additions may optionally be enabled by mapping to a
4809	>	* common value.  This class cannot be directly instantiated.
4810	>	* See {@link #keySet() keySet()},
4811	>	* {@link #keySet(Object) keySet(V)},
4812	>	* {@link #newKeySet() newKeySet()},
4813	>	* {@link #newKeySet(int) newKeySet(int)}.
4814	>	*/
4815	>	public static class KeySetView<K,V>
4816	>	extends CHMSetView<K,V,K>
4817	>	implements Set<K>, java.io.Serializable {
4818	>	private static final long serialVersionUID = 7249069246763182397L;
4819	>	private final V value;
4820	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4821	>	super(map);
4822	>	this.value = value;
4823	>	}
4824	>
4825	>	/**
4826	>	* Returns the default mapped value for additions,
4827	>	* or {@code null} if additions are not supported.
4828	>	*
4829	>	* @return the default mapped value for additions, or {@code null}
4830	>	* if not supported
4831	>	*/
4832	>	public V getMappedValue() { return value; }
4833	>
4834	>	/**
4835	>	* {@inheritDoc}
4836	>	* @throws NullPointerException if the specified key is null
4837	>	*/
4838	>	public boolean contains(Object o) { return map.containsKey(o); }
4839	>
4840	>	/**
4841	>	* Removes the key from this map view, by removing the key (and its
4842	>	* corresponding value) from the backing map.  This method does
4843	>	* nothing if the key is not in the map.
4844	>	*
4845	>	* @param  o the key to be removed from the backing map
4846	>	* @return {@code true} if the backing map contained the specified key
4847	>	* @throws NullPointerException if the specified key is null
4848	>	*/
4849	>	public boolean remove(Object o) { return map.remove(o) != null; }
4850	>
4851	>	/**
4852	>	* @return an iterator over the keys of the backing map
4853	>	*/
4854	>	public Iterator<K> iterator() { return new KeyIterator<K,V>(map); }
4855	>
4856	>	/**
4857	>	* Adds the specified key to this set view by mapping the key to
4858	>	* the default mapped value in the backing map, if defined.
4859	>	*
4860	>	* @param e key to be added
4861	>	* @return {@code true} if this set changed as a result of the call
4862	>	* @throws NullPointerException if the specified key is null
4863	>	* @throws UnsupportedOperationException if no default mapped value
4864	>	* for additions was provided
4865	>	*/
4866	>	public boolean add(K e) {
4867	>	V v;
4868	>	if ((v = value) == null)
4869	>	throw new UnsupportedOperationException();
4870	>	return map.internalPut(e, v, true) == null;
4871	>	}
4872	>
4873	>	/**
4874	>	* Adds all of the elements in the specified collection to this set,
4875	>	* as if by calling {@link #add} on each one.
4876	>	*
4877	>	* @param c the elements to be inserted into this set
4878	>	* @return {@code true} if this set changed as a result of the call
4879	>	* @throws NullPointerException if the collection or any of its
4880	>	* elements are {@code null}
4881	>	* @throws UnsupportedOperationException if no default mapped value
4882	>	* for additions was provided
4883	>	*/
4884	>	public boolean addAll(Collection<? extends K> c) {
4885	>	boolean added = false;
4886	>	V v;
4887	>	if ((v = value) == null)
4888	>	throw new UnsupportedOperationException();
4889	>	for (K e : c) {
4890	>	if (map.internalPut(e, v, true) == null)
4891	>	added = true;
4892	>	}
4893	>	return added;
4894	>	}
4895	>
4896	>	public Spliterator<K> spliterator() {
4897	>	return new KeyIterator<>(map, null);
4898	>	}
4899	>
4900	>	}
4901	>
4902	>	/**
4903	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4904	>	* values, in which additions are disabled. This class cannot be
4905	>	* directly instantiated. See {@link #values()}.
4906	>	*
4907	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4908	>	* that will never throw {@link ConcurrentModificationException},
4909	>	* and guarantees to traverse elements as they existed upon
4910	>	* construction of the iterator, and may (but is not guaranteed to)
4911	>	* reflect any modifications subsequent to construction.
4912	>	*/
4913	>	public static final class ValuesView<K,V>
4914	>	extends CHMCollectionView<K,V,V>
4915	>	implements Collection<V>, java.io.Serializable {
4916	>	private static final long serialVersionUID = 2249069246763182397L;
4917	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4918	>	public final boolean contains(Object o) {
4919	>	return map.containsValue(o);
4920	>	}
4921	>	public final boolean remove(Object o) {
4922	>	if (o != null) {
4923	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4924	>	if (o.equals(it.next())) {
4925	>	it.remove();
4926	>	return true;
4927		}
4928		}
1427	–	} finally {
1428	–	seg.unlock();
4929		}
4930	+	return false;
4931		}
4932	<	s.writeObject(null);
4933	<	s.writeObject(null);
4932	>
4933	>	/**
4934	>	* @return an iterator over the values of the backing map
4935	>	*/
4936	>	public final Iterator<V> iterator() {
4937	>	return new ValueIterator<K,V>(map);
4938	>	}
4939	>
4940	>	/** Always throws {@link UnsupportedOperationException}. */
4941	>	public final boolean add(V e) {
4942	>	throw new UnsupportedOperationException();
4943	>	}
4944	>	/** Always throws {@link UnsupportedOperationException}. */
4945	>	public final boolean addAll(Collection<? extends V> c) {
4946	>	throw new UnsupportedOperationException();
4947	>	}
4948	>
4949	>	public Spliterator<V> spliterator() {
4950	>	return new ValueIterator<K,V>(map, null);
4951	>	}
4952	>
4953		}
4954
4955		/**
4956	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4957	<	* stream (i.e., deserializes it).
4958	<	* @param s the stream
4956	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4957	>	* entries.  This class cannot be directly instantiated. See
4958	>	* {@link #entrySet()}.
4959		*/
4960	<	@SuppressWarnings("unchecked")
4961	<	private void readObject(java.io.ObjectInputStream s)
4962	<	throws IOException, ClassNotFoundException {
4963	<	s.defaultReadObject();
4960	>	public static final class EntrySetView<K,V>
4961	>	extends CHMSetView<K,V,Map.Entry<K,V>>
4962	>	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4963	>	private static final long serialVersionUID = 2249069246763182397L;
4964	>	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4965	>
4966	>	public final boolean contains(Object o) {
4967	>	Object k, v, r; Map.Entry<?,?> e;
4968	>	return ((o instanceof Map.Entry) &&
4969	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4970	>	(r = map.get(k)) != null &&
4971	>	(v = e.getValue()) != null &&
4972	>	(v == r || v.equals(r)));
4973	>	}
4974	>	public final boolean remove(Object o) {
4975	>	Object k, v; Map.Entry<?,?> e;
4976	>	return ((o instanceof Map.Entry) &&
4977	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4978	>	(v = e.getValue()) != null &&
4979	>	map.remove(k, v));
4980	>	}
4981
4982	<	// Re-initialize segments to be minimally sized, and let grow.
4983	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4984	<	final Segment<K,V>[] segments = this.segments;
4985	<	for (int k = 0; k < segments.length; ++k) {
4986	<	Segment<K,V> seg = segments[k];
4987	<	if (seg != null) {
4988	<	seg.threshold = (int)(cap * seg.loadFactor);
4989	<	seg.table = (HashEntry<K,V>[]) new HashEntry[cap];
4982	>	/**
4983	>	* @return an iterator over the entries of the backing map
4984	>	*/
4985	>	public final Iterator<Map.Entry<K,V>> iterator() {
4986	>	return new EntryIterator<K,V>(map);
4987	>	}
4988	>
4989	>	/**
4990	>	* Adds the specified mapping to this view.
4991	>	*
4992	>	* @param e mapping to be added
4993	>	* @return {@code true} if this set changed as a result of the call
4994	>	* @throws NullPointerException if the entry, its key, or its
4995	>	* value is null
4996	>	*/
4997	>	public final boolean add(Entry<K,V> e) {
4998	>	return map.internalPut(e.getKey(), e.getValue(), false) == null;
4999	>	}
5000	>
5001	>	/**
5002	>	* Adds all of the mappings in the specified collection to this
5003	>	* set, as if by calling {@link #add(Map.Entry)} on each one.
5004	>	* @param c the mappings to be inserted into this set
5005	>	* @return {@code true} if this set changed as a result of the call
5006	>	* @throws NullPointerException if the collection or any of its
5007	>	* entries, keys, or values are null
5008	>	*/
5009	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
5010	>	boolean added = false;
5011	>	for (Entry<K,V> e : c) {
5012	>	if (add(e))
5013	>	added = true;
5014		}
5015	+	return added;
5016		}
5017
5018	<	// Read the keys and values, and put the mappings in the table
5019	<	for (;;) {
5020	<	K key = (K) s.readObject();
5021	<	V value = (V) s.readObject();
5022	<	if (key == null)
5023	<	break;
5024	<	put(key, value);
5018	>	public Spliterator<Map.Entry<K,V>> spliterator() {
5019	>	return new EntryIterator<K,V>(map, null);
5020	>	}
5021	>
5022	>	}
5023	>
5024	>	// ---------------------------------------------------------------------
5025	>
5026	>	/**
5027	>	* Predefined tasks for performing bulk parallel operations on
5028	>	* ConcurrentHashMaps. These tasks follow the forms and rules used
5029	>	* for bulk operations. Each method has the same name, but returns
5030	>	* a task rather than invoking it. These methods may be useful in
5031	>	* custom applications such as submitting a task without waiting
5032	>	* for completion, using a custom pool, or combining with other
5033	>	* tasks.
5034	>	*/
5035	>	public static class ForkJoinTasks {
5036	>	private ForkJoinTasks() {}
5037	>
5038	>	/**
5039	>	* Returns a task that when invoked, performs the given
5040	>	* action for each (key, value)
5041	>	*
5042	>	* @param map the map
5043	>	* @param action the action
5044	>	* @return the task
5045	>	*/
5046	>	public static <K,V> ForkJoinTask<Void> forEach
5047	>	(ConcurrentHashMap<K,V> map,
5048	>	BiConsumer<? super K, ? super V> action) {
5049	>	if (action == null) throw new NullPointerException();
5050	>	return new ForEachMappingTask<K,V>(map, null, -1, action);
5051	>	}
5052	>
5053	>	/**
5054	>	* Returns a task that when invoked, performs the given
5055	>	* action for each non-null transformation of each (key, value)
5056	>	*
5057	>	* @param map the map
5058	>	* @param transformer a function returning the transformation
5059	>	* for an element, or null if there is no transformation (in
5060	>	* which case the action is not applied)
5061	>	* @param action the action
5062	>	* @return the task
5063	>	*/
5064	>	public static <K,V,U> ForkJoinTask<Void> forEach
5065	>	(ConcurrentHashMap<K,V> map,
5066	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5067	>	Consumer<? super U> action) {
5068	>	if (transformer == null || action == null)
5069	>	throw new NullPointerException();
5070	>	return new ForEachTransformedMappingTask<K,V,U>
5071	>	(map, null, -1, transformer, action);
5072	>	}
5073	>
5074	>	/**
5075	>	* Returns a task that when invoked, returns a non-null result
5076	>	* from applying the given search function on each (key,
5077	>	* value), or null if none. Upon success, further element
5078	>	* processing is suppressed and the results of any other
5079	>	* parallel invocations of the search function are ignored.
5080	>	*
5081	>	* @param map the map
5082	>	* @param searchFunction a function returning a non-null
5083	>	* result on success, else null
5084	>	* @return the task
5085	>	*/
5086	>	public static <K,V,U> ForkJoinTask<U> search
5087	>	(ConcurrentHashMap<K,V> map,
5088	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
5089	>	if (searchFunction == null) throw new NullPointerException();
5090	>	return new SearchMappingsTask<K,V,U>
5091	>	(map, null, -1, searchFunction,
5092	>	new AtomicReference<U>());
5093	>	}
5094	>
5095	>	/**
5096	>	* Returns a task that when invoked, returns the result of
5097	>	* accumulating the given transformation of all (key, value) pairs
5098	>	* using the given reducer to combine values, or null if none.
5099	>	*
5100	>	* @param map the map
5101	>	* @param transformer a function returning the transformation
5102	>	* for an element, or null if there is no transformation (in
5103	>	* which case it is not combined)
5104	>	* @param reducer a commutative associative combining function
5105	>	* @return the task
5106	>	*/
5107	>	public static <K,V,U> ForkJoinTask<U> reduce
5108	>	(ConcurrentHashMap<K,V> map,
5109	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5110	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5111	>	if (transformer == null || reducer == null)
5112	>	throw new NullPointerException();
5113	>	return new MapReduceMappingsTask<K,V,U>
5114	>	(map, null, -1, null, transformer, reducer);
5115	>	}
5116	>
5117	>	/**
5118	>	* Returns a task that when invoked, returns the result of
5119	>	* accumulating the given transformation of all (key, value) pairs
5120	>	* using the given reducer to combine values, and the given
5121	>	* basis as an identity value.
5122	>	*
5123	>	* @param map the map
5124	>	* @param transformer a function returning the transformation
5125	>	* for an element
5126	>	* @param basis the identity (initial default value) for the reduction
5127	>	* @param reducer a commutative associative combining function
5128	>	* @return the task
5129	>	*/
5130	>	public static <K,V> ForkJoinTask<Double> reduceToDouble
5131	>	(ConcurrentHashMap<K,V> map,
5132	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5133	>	double basis,
5134	>	DoubleBinaryOperator reducer) {
5135	>	if (transformer == null || reducer == null)
5136	>	throw new NullPointerException();
5137	>	return new MapReduceMappingsToDoubleTask<K,V>
5138	>	(map, null, -1, null, transformer, basis, reducer);
5139	>	}
5140	>
5141	>	/**
5142	>	* Returns a task that when invoked, returns the result of
5143	>	* accumulating the given transformation of all (key, value) pairs
5144	>	* using the given reducer to combine values, and the given
5145	>	* basis as an identity value.
5146	>	*
5147	>	* @param map the map
5148	>	* @param transformer a function returning the transformation
5149	>	* for an element
5150	>	* @param basis the identity (initial default value) for the reduction
5151	>	* @param reducer a commutative associative combining function
5152	>	* @return the task
5153	>	*/
5154	>	public static <K,V> ForkJoinTask<Long> reduceToLong
5155	>	(ConcurrentHashMap<K,V> map,
5156	>	ToLongBiFunction<? super K, ? super V> transformer,
5157	>	long basis,
5158	>	LongBinaryOperator reducer) {
5159	>	if (transformer == null || reducer == null)
5160	>	throw new NullPointerException();
5161	>	return new MapReduceMappingsToLongTask<K,V>
5162	>	(map, null, -1, null, transformer, basis, reducer);
5163	>	}
5164	>
5165	>	/**
5166	>	* Returns a task that when invoked, returns the result of
5167	>	* accumulating the given transformation of all (key, value) pairs
5168	>	* using the given reducer to combine values, and the given
5169	>	* basis as an identity value.
5170	>	*
5171	>	* @param map the map
5172	>	* @param transformer a function returning the transformation
5173	>	* for an element
5174	>	* @param basis the identity (initial default value) for the reduction
5175	>	* @param reducer a commutative associative combining function
5176	>	* @return the task
5177	>	*/
5178	>	public static <K,V> ForkJoinTask<Integer> reduceToInt
5179	>	(ConcurrentHashMap<K,V> map,
5180	>	ToIntBiFunction<? super K, ? super V> transformer,
5181	>	int basis,
5182	>	IntBinaryOperator reducer) {
5183	>	if (transformer == null || reducer == null)
5184	>	throw new NullPointerException();
5185	>	return new MapReduceMappingsToIntTask<K,V>
5186	>	(map, null, -1, null, transformer, basis, reducer);
5187	>	}
5188	>
5189	>	/**
5190	>	* Returns a task that when invoked, performs the given action
5191	>	* for each key.
5192	>	*
5193	>	* @param map the map
5194	>	* @param action the action
5195	>	* @return the task
5196	>	*/
5197	>	public static <K,V> ForkJoinTask<Void> forEachKey
5198	>	(ConcurrentHashMap<K,V> map,
5199	>	Consumer<? super K> action) {
5200	>	if (action == null) throw new NullPointerException();
5201	>	return new ForEachKeyTask<K,V>(map, null, -1, action);
5202	>	}
5203	>
5204	>	/**
5205	>	* Returns a task that when invoked, performs the given action
5206	>	* for each non-null transformation of each key.
5207	>	*
5208	>	* @param map the map
5209	>	* @param transformer a function returning the transformation
5210	>	* for an element, or null if there is no transformation (in
5211	>	* which case the action is not applied)
5212	>	* @param action the action
5213	>	* @return the task
5214	>	*/
5215	>	public static <K,V,U> ForkJoinTask<Void> forEachKey
5216	>	(ConcurrentHashMap<K,V> map,
5217	>	Function<? super K, ? extends U> transformer,
5218	>	Consumer<? super U> action) {
5219	>	if (transformer == null || action == null)
5220	>	throw new NullPointerException();
5221	>	return new ForEachTransformedKeyTask<K,V,U>
5222	>	(map, null, -1, transformer, action);
5223	>	}
5224	>
5225	>	/**
5226	>	* Returns a task that when invoked, returns a non-null result
5227	>	* from applying the given search function on each key, or
5228	>	* null if none.  Upon success, further element processing is
5229	>	* suppressed and the results of any other parallel
5230	>	* invocations of the search function are ignored.
5231	>	*
5232	>	* @param map the map
5233	>	* @param searchFunction a function returning a non-null
5234	>	* result on success, else null
5235	>	* @return the task
5236	>	*/
5237	>	public static <K,V,U> ForkJoinTask<U> searchKeys
5238	>	(ConcurrentHashMap<K,V> map,
5239	>	Function<? super K, ? extends U> searchFunction) {
5240	>	if (searchFunction == null) throw new NullPointerException();
5241	>	return new SearchKeysTask<K,V,U>
5242	>	(map, null, -1, searchFunction,
5243	>	new AtomicReference<U>());
5244	>	}
5245	>
5246	>	/**
5247	>	* Returns a task that when invoked, returns the result of
5248	>	* accumulating all keys using the given reducer to combine
5249	>	* values, or null if none.
5250	>	*
5251	>	* @param map the map
5252	>	* @param reducer a commutative associative combining function
5253	>	* @return the task
5254	>	*/
5255	>	public static <K,V> ForkJoinTask<K> reduceKeys
5256	>	(ConcurrentHashMap<K,V> map,
5257	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5258	>	if (reducer == null) throw new NullPointerException();
5259	>	return new ReduceKeysTask<K,V>
5260	>	(map, null, -1, null, reducer);
5261	>	}
5262	>
5263	>	/**
5264	>	* Returns a task that when invoked, returns the result of
5265	>	* accumulating the given transformation of all keys using the given
5266	>	* reducer to combine values, or null if none.
5267	>	*
5268	>	* @param map the map
5269	>	* @param transformer a function returning the transformation
5270	>	* for an element, or null if there is no transformation (in
5271	>	* which case it is not combined)
5272	>	* @param reducer a commutative associative combining function
5273	>	* @return the task
5274	>	*/
5275	>	public static <K,V,U> ForkJoinTask<U> reduceKeys
5276	>	(ConcurrentHashMap<K,V> map,
5277	>	Function<? super K, ? extends U> transformer,
5278	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5279	>	if (transformer == null || reducer == null)
5280	>	throw new NullPointerException();
5281	>	return new MapReduceKeysTask<K,V,U>
5282	>	(map, null, -1, null, transformer, reducer);
5283	>	}
5284	>
5285	>	/**
5286	>	* Returns a task that when invoked, returns the result of
5287	>	* accumulating the given transformation of all keys using the given
5288	>	* reducer to combine values, and the given basis as an
5289	>	* identity value.
5290	>	*
5291	>	* @param map the map
5292	>	* @param transformer a function returning the transformation
5293	>	* for an element
5294	>	* @param basis the identity (initial default value) for the reduction
5295	>	* @param reducer a commutative associative combining function
5296	>	* @return the task
5297	>	*/
5298	>	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
5299	>	(ConcurrentHashMap<K,V> map,
5300	>	ToDoubleFunction<? super K> transformer,
5301	>	double basis,
5302	>	DoubleBinaryOperator reducer) {
5303	>	if (transformer == null || reducer == null)
5304	>	throw new NullPointerException();
5305	>	return new MapReduceKeysToDoubleTask<K,V>
5306	>	(map, null, -1, null, transformer, basis, reducer);
5307	>	}
5308	>
5309	>	/**
5310	>	* Returns a task that when invoked, returns the result of
5311	>	* accumulating the given transformation of all keys using the given
5312	>	* reducer to combine values, and the given basis as an
5313	>	* identity value.
5314	>	*
5315	>	* @param map the map
5316	>	* @param transformer a function returning the transformation
5317	>	* for an element
5318	>	* @param basis the identity (initial default value) for the reduction
5319	>	* @param reducer a commutative associative combining function
5320	>	* @return the task
5321	>	*/
5322	>	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
5323	>	(ConcurrentHashMap<K,V> map,
5324	>	ToLongFunction<? super K> transformer,
5325	>	long basis,
5326	>	LongBinaryOperator reducer) {
5327	>	if (transformer == null || reducer == null)
5328	>	throw new NullPointerException();
5329	>	return new MapReduceKeysToLongTask<K,V>
5330	>	(map, null, -1, null, transformer, basis, reducer);
5331	>	}
5332	>
5333	>	/**
5334	>	* Returns a task that when invoked, returns the result of
5335	>	* accumulating the given transformation of all keys using the given
5336	>	* reducer to combine values, and the given basis as an
5337	>	* identity value.
5338	>	*
5339	>	* @param map the map
5340	>	* @param transformer a function returning the transformation
5341	>	* for an element
5342	>	* @param basis the identity (initial default value) for the reduction
5343	>	* @param reducer a commutative associative combining function
5344	>	* @return the task
5345	>	*/
5346	>	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5347	>	(ConcurrentHashMap<K,V> map,
5348	>	ToIntFunction<? super K> transformer,
5349	>	int basis,
5350	>	IntBinaryOperator reducer) {
5351	>	if (transformer == null || reducer == null)
5352	>	throw new NullPointerException();
5353	>	return new MapReduceKeysToIntTask<K,V>
5354	>	(map, null, -1, null, transformer, basis, reducer);
5355	>	}
5356	>
5357	>	/**
5358	>	* Returns a task that when invoked, performs the given action
5359	>	* for each value.
5360	>	*
5361	>	* @param map the map
5362	>	* @param action the action
5363	>	* @return the task
5364	>	*/
5365	>	public static <K,V> ForkJoinTask<Void> forEachValue
5366	>	(ConcurrentHashMap<K,V> map,
5367	>	Consumer<? super V> action) {
5368	>	if (action == null) throw new NullPointerException();
5369	>	return new ForEachValueTask<K,V>(map, null, -1, action);
5370	>	}
5371	>
5372	>	/**
5373	>	* Returns a task that when invoked, performs the given action
5374	>	* for each non-null transformation of each value.
5375	>	*
5376	>	* @param map the map
5377	>	* @param transformer a function returning the transformation
5378	>	* for an element, or null if there is no transformation (in
5379	>	* which case the action is not applied)
5380	>	* @param action the action
5381	>	* @return the task
5382	>	*/
5383	>	public static <K,V,U> ForkJoinTask<Void> forEachValue
5384	>	(ConcurrentHashMap<K,V> map,
5385	>	Function<? super V, ? extends U> transformer,
5386	>	Consumer<? super U> action) {
5387	>	if (transformer == null || action == null)
5388	>	throw new NullPointerException();
5389	>	return new ForEachTransformedValueTask<K,V,U>
5390	>	(map, null, -1, transformer, action);
5391	>	}
5392	>
5393	>	/**
5394	>	* Returns a task that when invoked, returns a non-null result
5395	>	* from applying the given search function on each value, or
5396	>	* null if none.  Upon success, further element processing is
5397	>	* suppressed and the results of any other parallel
5398	>	* invocations of the search function are ignored.
5399	>	*
5400	>	* @param map the map
5401	>	* @param searchFunction a function returning a non-null
5402	>	* result on success, else null
5403	>	* @return the task
5404	>	*/
5405	>	public static <K,V,U> ForkJoinTask<U> searchValues
5406	>	(ConcurrentHashMap<K,V> map,
5407	>	Function<? super V, ? extends U> searchFunction) {
5408	>	if (searchFunction == null) throw new NullPointerException();
5409	>	return new SearchValuesTask<K,V,U>
5410	>	(map, null, -1, searchFunction,
5411	>	new AtomicReference<U>());
5412	>	}
5413	>
5414	>	/**
5415	>	* Returns a task that when invoked, returns the result of
5416	>	* accumulating all values using the given reducer to combine
5417	>	* values, or null if none.
5418	>	*
5419	>	* @param map the map
5420	>	* @param reducer a commutative associative combining function
5421	>	* @return the task
5422	>	*/
5423	>	public static <K,V> ForkJoinTask<V> reduceValues
5424	>	(ConcurrentHashMap<K,V> map,
5425	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5426	>	if (reducer == null) throw new NullPointerException();
5427	>	return new ReduceValuesTask<K,V>
5428	>	(map, null, -1, null, reducer);
5429	>	}
5430	>
5431	>	/**
5432	>	* Returns a task that when invoked, returns the result of
5433	>	* accumulating the given transformation of all values using the
5434	>	* given reducer to combine values, or null if none.
5435	>	*
5436	>	* @param map the map
5437	>	* @param transformer a function returning the transformation
5438	>	* for an element, or null if there is no transformation (in
5439	>	* which case it is not combined)
5440	>	* @param reducer a commutative associative combining function
5441	>	* @return the task
5442	>	*/
5443	>	public static <K,V,U> ForkJoinTask<U> reduceValues
5444	>	(ConcurrentHashMap<K,V> map,
5445	>	Function<? super V, ? extends U> transformer,
5446	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5447	>	if (transformer == null || reducer == null)
5448	>	throw new NullPointerException();
5449	>	return new MapReduceValuesTask<K,V,U>
5450	>	(map, null, -1, null, transformer, reducer);
5451	>	}
5452	>
5453	>	/**
5454	>	* Returns a task that when invoked, returns the result of
5455	>	* accumulating the given transformation of all values using the
5456	>	* given reducer to combine values, and the given basis as an
5457	>	* identity value.
5458	>	*
5459	>	* @param map the map
5460	>	* @param transformer a function returning the transformation
5461	>	* for an element
5462	>	* @param basis the identity (initial default value) for the reduction
5463	>	* @param reducer a commutative associative combining function
5464	>	* @return the task
5465	>	*/
5466	>	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5467	>	(ConcurrentHashMap<K,V> map,
5468	>	ToDoubleFunction<? super V> transformer,
5469	>	double basis,
5470	>	DoubleBinaryOperator reducer) {
5471	>	if (transformer == null || reducer == null)
5472	>	throw new NullPointerException();
5473	>	return new MapReduceValuesToDoubleTask<K,V>
5474	>	(map, null, -1, null, transformer, basis, reducer);
5475	>	}
5476	>
5477	>	/**
5478	>	* Returns a task that when invoked, returns the result of
5479	>	* accumulating the given transformation of all values using the
5480	>	* given reducer to combine values, and the given basis as an
5481	>	* identity value.
5482	>	*
5483	>	* @param map the map
5484	>	* @param transformer a function returning the transformation
5485	>	* for an element
5486	>	* @param basis the identity (initial default value) for the reduction
5487	>	* @param reducer a commutative associative combining function
5488	>	* @return the task
5489	>	*/
5490	>	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5491	>	(ConcurrentHashMap<K,V> map,
5492	>	ToLongFunction<? super V> transformer,
5493	>	long basis,
5494	>	LongBinaryOperator reducer) {
5495	>	if (transformer == null || reducer == null)
5496	>	throw new NullPointerException();
5497	>	return new MapReduceValuesToLongTask<K,V>
5498	>	(map, null, -1, null, transformer, basis, reducer);
5499	>	}
5500	>
5501	>	/**
5502	>	* Returns a task that when invoked, returns the result of
5503	>	* accumulating the given transformation of all values using the
5504	>	* given reducer to combine values, and the given basis as an
5505	>	* identity value.
5506	>	*
5507	>	* @param map the map
5508	>	* @param transformer a function returning the transformation
5509	>	* for an element
5510	>	* @param basis the identity (initial default value) for the reduction
5511	>	* @param reducer a commutative associative combining function
5512	>	* @return the task
5513	>	*/
5514	>	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5515	>	(ConcurrentHashMap<K,V> map,
5516	>	ToIntFunction<? super V> transformer,
5517	>	int basis,
5518	>	IntBinaryOperator reducer) {
5519	>	if (transformer == null || reducer == null)
5520	>	throw new NullPointerException();
5521	>	return new MapReduceValuesToIntTask<K,V>
5522	>	(map, null, -1, null, transformer, basis, reducer);
5523	>	}
5524	>
5525	>	/**
5526	>	* Returns a task that when invoked, perform the given action
5527	>	* for each entry.
5528	>	*
5529	>	* @param map the map
5530	>	* @param action the action
5531	>	* @return the task
5532	>	*/
5533	>	public static <K,V> ForkJoinTask<Void> forEachEntry
5534	>	(ConcurrentHashMap<K,V> map,
5535	>	Consumer<? super Map.Entry<K,V>> action) {
5536	>	if (action == null) throw new NullPointerException();
5537	>	return new ForEachEntryTask<K,V>(map, null, -1, action);
5538	>	}
5539	>
5540	>	/**
5541	>	* Returns a task that when invoked, perform the given action
5542	>	* for each non-null transformation of each entry.
5543	>	*
5544	>	* @param map the map
5545	>	* @param transformer a function returning the transformation
5546	>	* for an element, or null if there is no transformation (in
5547	>	* which case the action is not applied)
5548	>	* @param action the action
5549	>	* @return the task
5550	>	*/
5551	>	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5552	>	(ConcurrentHashMap<K,V> map,
5553	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5554	>	Consumer<? super U> action) {
5555	>	if (transformer == null || action == null)
5556	>	throw new NullPointerException();
5557	>	return new ForEachTransformedEntryTask<K,V,U>
5558	>	(map, null, -1, transformer, action);
5559	>	}
5560	>
5561	>	/**
5562	>	* Returns a task that when invoked, returns a non-null result
5563	>	* from applying the given search function on each entry, or
5564	>	* null if none.  Upon success, further element processing is
5565	>	* suppressed and the results of any other parallel
5566	>	* invocations of the search function are ignored.
5567	>	*
5568	>	* @param map the map
5569	>	* @param searchFunction a function returning a non-null
5570	>	* result on success, else null
5571	>	* @return the task
5572	>	*/
5573	>	public static <K,V,U> ForkJoinTask<U> searchEntries
5574	>	(ConcurrentHashMap<K,V> map,
5575	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
5576	>	if (searchFunction == null) throw new NullPointerException();
5577	>	return new SearchEntriesTask<K,V,U>
5578	>	(map, null, -1, searchFunction,
5579	>	new AtomicReference<U>());
5580	>	}
5581	>
5582	>	/**
5583	>	* Returns a task that when invoked, returns the result of
5584	>	* accumulating all entries using the given reducer to combine
5585	>	* values, or null if none.
5586	>	*
5587	>	* @param map the map
5588	>	* @param reducer a commutative associative combining function
5589	>	* @return the task
5590	>	*/
5591	>	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5592	>	(ConcurrentHashMap<K,V> map,
5593	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5594	>	if (reducer == null) throw new NullPointerException();
5595	>	return new ReduceEntriesTask<K,V>
5596	>	(map, null, -1, null, reducer);
5597	>	}
5598	>
5599	>	/**
5600	>	* Returns a task that when invoked, returns the result of
5601	>	* accumulating the given transformation of all entries using the
5602	>	* given reducer to combine values, or null if none.
5603	>	*
5604	>	* @param map the map
5605	>	* @param transformer a function returning the transformation
5606	>	* for an element, or null if there is no transformation (in
5607	>	* which case it is not combined)
5608	>	* @param reducer a commutative associative combining function
5609	>	* @return the task
5610	>	*/
5611	>	public static <K,V,U> ForkJoinTask<U> reduceEntries
5612	>	(ConcurrentHashMap<K,V> map,
5613	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5614	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5615	>	if (transformer == null || reducer == null)
5616	>	throw new NullPointerException();
5617	>	return new MapReduceEntriesTask<K,V,U>
5618	>	(map, null, -1, null, transformer, reducer);
5619	>	}
5620	>
5621	>	/**
5622	>	* Returns a task that when invoked, returns the result of
5623	>	* accumulating the given transformation of all entries using the
5624	>	* given reducer to combine values, and the given basis as an
5625	>	* identity value.
5626	>	*
5627	>	* @param map the map
5628	>	* @param transformer a function returning the transformation
5629	>	* for an element
5630	>	* @param basis the identity (initial default value) for the reduction
5631	>	* @param reducer a commutative associative combining function
5632	>	* @return the task
5633	>	*/
5634	>	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5635	>	(ConcurrentHashMap<K,V> map,
5636	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5637	>	double basis,
5638	>	DoubleBinaryOperator reducer) {
5639	>	if (transformer == null || reducer == null)
5640	>	throw new NullPointerException();
5641	>	return new MapReduceEntriesToDoubleTask<K,V>
5642	>	(map, null, -1, null, transformer, basis, reducer);
5643	>	}
5644	>
5645	>	/**
5646	>	* Returns a task that when invoked, returns the result of
5647	>	* accumulating the given transformation of all entries using the
5648	>	* given reducer to combine values, and the given basis as an
5649	>	* identity value.
5650	>	*
5651	>	* @param map the map
5652	>	* @param transformer a function returning the transformation
5653	>	* for an element
5654	>	* @param basis the identity (initial default value) for the reduction
5655	>	* @param reducer a commutative associative combining function
5656	>	* @return the task
5657	>	*/
5658	>	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5659	>	(ConcurrentHashMap<K,V> map,
5660	>	ToLongFunction<Map.Entry<K,V>> transformer,
5661	>	long basis,
5662	>	LongBinaryOperator reducer) {
5663	>	if (transformer == null || reducer == null)
5664	>	throw new NullPointerException();
5665	>	return new MapReduceEntriesToLongTask<K,V>
5666	>	(map, null, -1, null, transformer, basis, reducer);
5667	>	}
5668	>
5669	>	/**
5670	>	* Returns a task that when invoked, returns the result of
5671	>	* accumulating the given transformation of all entries using the
5672	>	* given reducer to combine values, and the given basis as an
5673	>	* identity value.
5674	>	*
5675	>	* @param map the map
5676	>	* @param transformer a function returning the transformation
5677	>	* for an element
5678	>	* @param basis the identity (initial default value) for the reduction
5679	>	* @param reducer a commutative associative combining function
5680	>	* @return the task
5681	>	*/
5682	>	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5683	>	(ConcurrentHashMap<K,V> map,
5684	>	ToIntFunction<Map.Entry<K,V>> transformer,
5685	>	int basis,
5686	>	IntBinaryOperator reducer) {
5687	>	if (transformer == null || reducer == null)
5688	>	throw new NullPointerException();
5689	>	return new MapReduceEntriesToIntTask<K,V>
5690	>	(map, null, -1, null, transformer, basis, reducer);
5691	>	}
5692	>	}
5693	>
5694	>	// -------------------------------------------------------
5695	>
5696	>	/*
5697	>	* Task classes. Coded in a regular but ugly format/style to
5698	>	* simplify checks that each variant differs in the right way from
5699	>	* others. The null screenings exist because compilers cannot tell
5700	>	* that we've already null-checked task arguments, so we force
5701	>	* simplest hoisted bypass to help avoid convoluted traps.
5702	>	*/
5703	>
5704	>	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5705	>	extends Traverser<K,V,Void> {
5706	>	final Consumer<? super K> action;
5707	>	ForEachKeyTask
5708	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5709	>	Consumer<? super K> action) {
5710	>	super(m, p, b);
5711	>	this.action = action;
5712	>	}
5713	>	public final void compute() {
5714	>	final Consumer<? super K> action;
5715	>	if ((action = this.action) != null) {
5716	>	for (int b; (b = preSplit()) > 0;)
5717	>	new ForEachKeyTask<K,V>(map, this, b, action).fork();
5718	>	forEachKey(action);
5719	>	propagateCompletion();
5720	>	}
5721	>	}
5722	>	}
5723	>
5724	>	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5725	>	extends Traverser<K,V,Void> {
5726	>	final Consumer<? super V> action;
5727	>	ForEachValueTask
5728	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5729	>	Consumer<? super V> action) {
5730	>	super(m, p, b);
5731	>	this.action = action;
5732	>	}
5733	>	public final void compute() {
5734	>	final Consumer<? super V> action;
5735	>	if ((action = this.action) != null) {
5736	>	for (int b; (b = preSplit()) > 0;)
5737	>	new ForEachValueTask<K,V>(map, this, b, action).fork();
5738	>	forEachValue(action);
5739	>	propagateCompletion();
5740	>	}
5741	>	}
5742	>	}
5743	>
5744	>	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5745	>	extends Traverser<K,V,Void> {
5746	>	final Consumer<? super Entry<K,V>> action;
5747	>	ForEachEntryTask
5748	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5749	>	Consumer<? super Entry<K,V>> action) {
5750	>	super(m, p, b);
5751	>	this.action = action;
5752	>	}
5753	>	public final void compute() {
5754	>	final Consumer<? super Entry<K,V>> action;
5755	>	if ((action = this.action) != null) {
5756	>	for (int b; (b = preSplit()) > 0;)
5757	>	new ForEachEntryTask<K,V>(map, this, b, action).fork();
5758	>	V v;
5759	>	while ((v = advanceValue()) != null)
5760	>	action.accept(entryFor(nextKey, v));
5761	>	propagateCompletion();
5762	>	}
5763	>	}
5764	>	}
5765	>
5766	>	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5767	>	extends Traverser<K,V,Void> {
5768	>	final BiConsumer<? super K, ? super V> action;
5769	>	ForEachMappingTask
5770	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5771	>	BiConsumer<? super K,? super V> action) {
5772	>	super(m, p, b);
5773	>	this.action = action;
5774	>	}
5775	>	public final void compute() {
5776	>	final BiConsumer<? super K, ? super V> action;
5777	>	if ((action = this.action) != null) {
5778	>	for (int b; (b = preSplit()) > 0;)
5779	>	new ForEachMappingTask<K,V>(map, this, b, action).fork();
5780	>	V v;
5781	>	while ((v = advanceValue()) != null)
5782	>	action.accept(nextKey, v);
5783	>	propagateCompletion();
5784	>	}
5785	>	}
5786	>	}
5787	>
5788	>	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5789	>	extends Traverser<K,V,Void> {
5790	>	final Function<? super K, ? extends U> transformer;
5791	>	final Consumer<? super U> action;
5792	>	ForEachTransformedKeyTask
5793	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5794	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5795	>	super(m, p, b);
5796	>	this.transformer = transformer; this.action = action;
5797	>	}
5798	>	public final void compute() {
5799	>	final Function<? super K, ? extends U> transformer;
5800	>	final Consumer<? super U> action;
5801	>	if ((transformer = this.transformer) != null &&
5802	>	(action = this.action) != null) {
5803	>	for (int b; (b = preSplit()) > 0;)
5804	>	new ForEachTransformedKeyTask<K,V,U>
5805	>	(map, this, b, transformer, action).fork();
5806	>	K k; U u;
5807	>	while ((k = advanceKey()) != null) {
5808	>	if ((u = transformer.apply(k)) != null)
5809	>	action.accept(u);
5810	>	}
5811	>	propagateCompletion();
5812	>	}
5813	>	}
5814	>	}
5815	>
5816	>	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5817	>	extends Traverser<K,V,Void> {
5818	>	final Function<? super V, ? extends U> transformer;
5819	>	final Consumer<? super U> action;
5820	>	ForEachTransformedValueTask
5821	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5822	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5823	>	super(m, p, b);
5824	>	this.transformer = transformer; this.action = action;
5825	>	}
5826	>	public final void compute() {
5827	>	final Function<? super V, ? extends U> transformer;
5828	>	final Consumer<? super U> action;
5829	>	if ((transformer = this.transformer) != null &&
5830	>	(action = this.action) != null) {
5831	>	for (int b; (b = preSplit()) > 0;)
5832	>	new ForEachTransformedValueTask<K,V,U>
5833	>	(map, this, b, transformer, action).fork();
5834	>	V v; U u;
5835	>	while ((v = advanceValue()) != null) {
5836	>	if ((u = transformer.apply(v)) != null)
5837	>	action.accept(u);
5838	>	}
5839	>	propagateCompletion();
5840	>	}
5841	>	}
5842	>	}
5843	>
5844	>	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5845	>	extends Traverser<K,V,Void> {
5846	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5847	>	final Consumer<? super U> action;
5848	>	ForEachTransformedEntryTask
5849	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5850	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5851	>	super(m, p, b);
5852	>	this.transformer = transformer; this.action = action;
5853	>	}
5854	>	public final void compute() {
5855	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5856	>	final Consumer<? super U> action;
5857	>	if ((transformer = this.transformer) != null &&
5858	>	(action = this.action) != null) {
5859	>	for (int b; (b = preSplit()) > 0;)
5860	>	new ForEachTransformedEntryTask<K,V,U>
5861	>	(map, this, b, transformer, action).fork();
5862	>	V v; U u;
5863	>	while ((v = advanceValue()) != null) {
5864	>	if ((u = transformer.apply(entryFor(nextKey,
5865	>	v))) != null)
5866	>	action.accept(u);
5867	>	}
5868	>	propagateCompletion();
5869	>	}
5870	>	}
5871	>	}
5872	>
5873	>	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5874	>	extends Traverser<K,V,Void> {
5875	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5876	>	final Consumer<? super U> action;
5877	>	ForEachTransformedMappingTask
5878	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5879	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5880	>	Consumer<? super U> action) {
5881	>	super(m, p, b);
5882	>	this.transformer = transformer; this.action = action;
5883	>	}
5884	>	public final void compute() {
5885	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5886	>	final Consumer<? super U> action;
5887	>	if ((transformer = this.transformer) != null &&
5888	>	(action = this.action) != null) {
5889	>	for (int b; (b = preSplit()) > 0;)
5890	>	new ForEachTransformedMappingTask<K,V,U>
5891	>	(map, this, b, transformer, action).fork();
5892	>	V v; U u;
5893	>	while ((v = advanceValue()) != null) {
5894	>	if ((u = transformer.apply(nextKey, v)) != null)
5895	>	action.accept(u);
5896	>	}
5897	>	propagateCompletion();
5898	>	}
5899	>	}
5900	>	}
5901	>
5902	>	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5903	>	extends Traverser<K,V,U> {
5904	>	final Function<? super K, ? extends U> searchFunction;
5905	>	final AtomicReference<U> result;
5906	>	SearchKeysTask
5907	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5908	>	Function<? super K, ? extends U> searchFunction,
5909	>	AtomicReference<U> result) {
5910	>	super(m, p, b);
5911	>	this.searchFunction = searchFunction; this.result = result;
5912	>	}
5913	>	public final U getRawResult() { return result.get(); }
5914	>	public final void compute() {
5915	>	final Function<? super K, ? extends U> searchFunction;
5916	>	final AtomicReference<U> result;
5917	>	if ((searchFunction = this.searchFunction) != null &&
5918	>	(result = this.result) != null) {
5919	>	for (int b;;) {
5920	>	if (result.get() != null)
5921	>	return;
5922	>	if ((b = preSplit()) <= 0)
5923	>	break;
5924	>	new SearchKeysTask<K,V,U>
5925	>	(map, this, b, searchFunction, result).fork();
5926	>	}
5927	>	while (result.get() == null) {
5928	>	K k; U u;
5929	>	if ((k = advanceKey()) == null) {
5930	>	propagateCompletion();
5931	>	break;
5932	>	}
5933	>	if ((u = searchFunction.apply(k)) != null) {
5934	>	if (result.compareAndSet(null, u))
5935	>	quietlyCompleteRoot();
5936	>	break;
5937	>	}
5938	>	}
5939	>	}
5940	>	}
5941	>	}
5942	>
5943	>	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5944	>	extends Traverser<K,V,U> {
5945	>	final Function<? super V, ? extends U> searchFunction;
5946	>	final AtomicReference<U> result;
5947	>	SearchValuesTask
5948	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5949	>	Function<? super V, ? extends U> searchFunction,
5950	>	AtomicReference<U> result) {
5951	>	super(m, p, b);
5952	>	this.searchFunction = searchFunction; this.result = result;
5953	>	}
5954	>	public final U getRawResult() { return result.get(); }
5955	>	public final void compute() {
5956	>	final Function<? super V, ? extends U> searchFunction;
5957	>	final AtomicReference<U> result;
5958	>	if ((searchFunction = this.searchFunction) != null &&
5959	>	(result = this.result) != null) {
5960	>	for (int b;;) {
5961	>	if (result.get() != null)
5962	>	return;
5963	>	if ((b = preSplit()) <= 0)
5964	>	break;
5965	>	new SearchValuesTask<K,V,U>
5966	>	(map, this, b, searchFunction, result).fork();
5967	>	}
5968	>	while (result.get() == null) {
5969	>	V v; U u;
5970	>	if ((v = advanceValue()) == null) {
5971	>	propagateCompletion();
5972	>	break;
5973	>	}
5974	>	if ((u = searchFunction.apply(v)) != null) {
5975	>	if (result.compareAndSet(null, u))
5976	>	quietlyCompleteRoot();
5977	>	break;
5978	>	}
5979	>	}
5980	>	}
5981	>	}
5982	>	}
5983	>
5984	>	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
5985	>	extends Traverser<K,V,U> {
5986	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5987	>	final AtomicReference<U> result;
5988	>	SearchEntriesTask
5989	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5990	>	Function<Entry<K,V>, ? extends U> searchFunction,
5991	>	AtomicReference<U> result) {
5992	>	super(m, p, b);
5993	>	this.searchFunction = searchFunction; this.result = result;
5994	>	}
5995	>	public final U getRawResult() { return result.get(); }
5996	>	public final void compute() {
5997	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5998	>	final AtomicReference<U> result;
5999	>	if ((searchFunction = this.searchFunction) != null &&
6000	>	(result = this.result) != null) {
6001	>	for (int b;;) {
6002	>	if (result.get() != null)
6003	>	return;
6004	>	if ((b = preSplit()) <= 0)
6005	>	break;
6006	>	new SearchEntriesTask<K,V,U>
6007	>	(map, this, b, searchFunction, result).fork();
6008	>	}
6009	>	while (result.get() == null) {
6010	>	V v; U u;
6011	>	if ((v = advanceValue()) == null) {
6012	>	propagateCompletion();
6013	>	break;
6014	>	}
6015	>	if ((u = searchFunction.apply(entryFor(nextKey,
6016	>	v))) != null) {
6017	>	if (result.compareAndSet(null, u))
6018	>	quietlyCompleteRoot();
6019	>	return;
6020	>	}
6021	>	}
6022	>	}
6023	>	}
6024	>	}
6025	>
6026	>	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
6027	>	extends Traverser<K,V,U> {
6028	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
6029	>	final AtomicReference<U> result;
6030	>	SearchMappingsTask
6031	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6032	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
6033	>	AtomicReference<U> result) {
6034	>	super(m, p, b);
6035	>	this.searchFunction = searchFunction; this.result = result;
6036	>	}
6037	>	public final U getRawResult() { return result.get(); }
6038	>	public final void compute() {
6039	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
6040	>	final AtomicReference<U> result;
6041	>	if ((searchFunction = this.searchFunction) != null &&
6042	>	(result = this.result) != null) {
6043	>	for (int b;;) {
6044	>	if (result.get() != null)
6045	>	return;
6046	>	if ((b = preSplit()) <= 0)
6047	>	break;
6048	>	new SearchMappingsTask<K,V,U>
6049	>	(map, this, b, searchFunction, result).fork();
6050	>	}
6051	>	while (result.get() == null) {
6052	>	V v; U u;
6053	>	if ((v = advanceValue()) == null) {
6054	>	propagateCompletion();
6055	>	break;
6056	>	}
6057	>	if ((u = searchFunction.apply(nextKey, v)) != null) {
6058	>	if (result.compareAndSet(null, u))
6059	>	quietlyCompleteRoot();
6060	>	break;
6061	>	}
6062	>	}
6063	>	}
6064	>	}
6065	>	}
6066	>
6067	>	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
6068	>	extends Traverser<K,V,K> {
6069	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
6070	>	K result;
6071	>	ReduceKeysTask<K,V> rights, nextRight;
6072	>	ReduceKeysTask
6073	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6074	>	ReduceKeysTask<K,V> nextRight,
6075	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
6076	>	super(m, p, b); this.nextRight = nextRight;
6077	>	this.reducer = reducer;
6078	>	}
6079	>	public final K getRawResult() { return result; }
6080	>	@SuppressWarnings("unchecked") public final void compute() {
6081	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
6082	>	if ((reducer = this.reducer) != null) {
6083	>	for (int b; (b = preSplit()) > 0;)
6084	>	(rights = new ReduceKeysTask<K,V>
6085	>	(map, this, b, rights, reducer)).fork();
6086	>	K u, r = null;
6087	>	while ((u = advanceKey()) != null) {
6088	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
6089	>	}
6090	>	result = r;
6091	>	CountedCompleter<?> c;
6092	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6093	>	ReduceKeysTask<K,V>
6094	>	t = (ReduceKeysTask<K,V>)c,
6095	>	s = t.rights;
6096	>	while (s != null) {
6097	>	K tr, sr;
6098	>	if ((sr = s.result) != null)
6099	>	t.result = (((tr = t.result) == null) ? sr :
6100	>	reducer.apply(tr, sr));
6101	>	s = t.rights = s.nextRight;
6102	>	}
6103	>	}
6104	>	}
6105	>	}
6106	>	}
6107	>
6108	>	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
6109	>	extends Traverser<K,V,V> {
6110	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
6111	>	V result;
6112	>	ReduceValuesTask<K,V> rights, nextRight;
6113	>	ReduceValuesTask
6114	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6115	>	ReduceValuesTask<K,V> nextRight,
6116	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
6117	>	super(m, p, b); this.nextRight = nextRight;
6118	>	this.reducer = reducer;
6119	>	}
6120	>	public final V getRawResult() { return result; }
6121	>	@SuppressWarnings("unchecked") public final void compute() {
6122	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
6123	>	if ((reducer = this.reducer) != null) {
6124	>	for (int b; (b = preSplit()) > 0;)
6125	>	(rights = new ReduceValuesTask<K,V>
6126	>	(map, this, b, rights, reducer)).fork();
6127	>	V r = null, v;
6128	>	while ((v = advanceValue()) != null)
6129	>	r = (r == null) ? v : reducer.apply(r, v);
6130	>	result = r;
6131	>	CountedCompleter<?> c;
6132	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6133	>	ReduceValuesTask<K,V>
6134	>	t = (ReduceValuesTask<K,V>)c,
6135	>	s = t.rights;
6136	>	while (s != null) {
6137	>	V tr, sr;
6138	>	if ((sr = s.result) != null)
6139	>	t.result = (((tr = t.result) == null) ? sr :
6140	>	reducer.apply(tr, sr));
6141	>	s = t.rights = s.nextRight;
6142	>	}
6143	>	}
6144	>	}
6145	>	}
6146	>	}
6147	>
6148	>	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
6149	>	extends Traverser<K,V,Map.Entry<K,V>> {
6150	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
6151	>	Map.Entry<K,V> result;
6152	>	ReduceEntriesTask<K,V> rights, nextRight;
6153	>	ReduceEntriesTask
6154	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6155	>	ReduceEntriesTask<K,V> nextRight,
6156	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
6157	>	super(m, p, b); this.nextRight = nextRight;
6158	>	this.reducer = reducer;
6159	>	}
6160	>	public final Map.Entry<K,V> getRawResult() { return result; }
6161	>	@SuppressWarnings("unchecked") public final void compute() {
6162	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
6163	>	if ((reducer = this.reducer) != null) {
6164	>	for (int b; (b = preSplit()) > 0;)
6165	>	(rights = new ReduceEntriesTask<K,V>
6166	>	(map, this, b, rights, reducer)).fork();
6167	>	Map.Entry<K,V> r = null;
6168	>	V v;
6169	>	while ((v = advanceValue()) != null) {
6170	>	Map.Entry<K,V> u = entryFor(nextKey, v);
6171	>	r = (r == null) ? u : reducer.apply(r, u);
6172	>	}
6173	>	result = r;
6174	>	CountedCompleter<?> c;
6175	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6176	>	ReduceEntriesTask<K,V>
6177	>	t = (ReduceEntriesTask<K,V>)c,
6178	>	s = t.rights;
6179	>	while (s != null) {
6180	>	Map.Entry<K,V> tr, sr;
6181	>	if ((sr = s.result) != null)
6182	>	t.result = (((tr = t.result) == null) ? sr :
6183	>	reducer.apply(tr, sr));
6184	>	s = t.rights = s.nextRight;
6185	>	}
6186	>	}
6187	>	}
6188	>	}
6189	>	}
6190	>
6191	>	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
6192	>	extends Traverser<K,V,U> {
6193	>	final Function<? super K, ? extends U> transformer;
6194	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6195	>	U result;
6196	>	MapReduceKeysTask<K,V,U> rights, nextRight;
6197	>	MapReduceKeysTask
6198	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6199	>	MapReduceKeysTask<K,V,U> nextRight,
6200	>	Function<? super K, ? extends U> transformer,
6201	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6202	>	super(m, p, b); this.nextRight = nextRight;
6203	>	this.transformer = transformer;
6204	>	this.reducer = reducer;
6205	>	}
6206	>	public final U getRawResult() { return result; }
6207	>	@SuppressWarnings("unchecked") public final void compute() {
6208	>	final Function<? super K, ? extends U> transformer;
6209	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6210	>	if ((transformer = this.transformer) != null &&
6211	>	(reducer = this.reducer) != null) {
6212	>	for (int b; (b = preSplit()) > 0;)
6213	>	(rights = new MapReduceKeysTask<K,V,U>
6214	>	(map, this, b, rights, transformer, reducer)).fork();
6215	>	K k; U r = null, u;
6216	>	while ((k = advanceKey()) != null) {
6217	>	if ((u = transformer.apply(k)) != null)
6218	>	r = (r == null) ? u : reducer.apply(r, u);
6219	>	}
6220	>	result = r;
6221	>	CountedCompleter<?> c;
6222	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6223	>	MapReduceKeysTask<K,V,U>
6224	>	t = (MapReduceKeysTask<K,V,U>)c,
6225	>	s = t.rights;
6226	>	while (s != null) {
6227	>	U tr, sr;
6228	>	if ((sr = s.result) != null)
6229	>	t.result = (((tr = t.result) == null) ? sr :
6230	>	reducer.apply(tr, sr));
6231	>	s = t.rights = s.nextRight;
6232	>	}
6233	>	}
6234	>	}
6235	>	}
6236	>	}
6237	>
6238	>	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
6239	>	extends Traverser<K,V,U> {
6240	>	final Function<? super V, ? extends U> transformer;
6241	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6242	>	U result;
6243	>	MapReduceValuesTask<K,V,U> rights, nextRight;
6244	>	MapReduceValuesTask
6245	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6246	>	MapReduceValuesTask<K,V,U> nextRight,
6247	>	Function<? super V, ? extends U> transformer,
6248	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6249	>	super(m, p, b); this.nextRight = nextRight;
6250	>	this.transformer = transformer;
6251	>	this.reducer = reducer;
6252	>	}
6253	>	public final U getRawResult() { return result; }
6254	>	@SuppressWarnings("unchecked") public final void compute() {
6255	>	final Function<? super V, ? extends U> transformer;
6256	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6257	>	if ((transformer = this.transformer) != null &&
6258	>	(reducer = this.reducer) != null) {
6259	>	for (int b; (b = preSplit()) > 0;)
6260	>	(rights = new MapReduceValuesTask<K,V,U>
6261	>	(map, this, b, rights, transformer, reducer)).fork();
6262	>	U r = null, u;
6263	>	V v;
6264	>	while ((v = advanceValue()) != null) {
6265	>	if ((u = transformer.apply(v)) != null)
6266	>	r = (r == null) ? u : reducer.apply(r, u);
6267	>	}
6268	>	result = r;
6269	>	CountedCompleter<?> c;
6270	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6271	>	MapReduceValuesTask<K,V,U>
6272	>	t = (MapReduceValuesTask<K,V,U>)c,
6273	>	s = t.rights;
6274	>	while (s != null) {
6275	>	U tr, sr;
6276	>	if ((sr = s.result) != null)
6277	>	t.result = (((tr = t.result) == null) ? sr :
6278	>	reducer.apply(tr, sr));
6279	>	s = t.rights = s.nextRight;
6280	>	}
6281	>	}
6282	>	}
6283	>	}
6284	>	}
6285	>
6286	>	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
6287	>	extends Traverser<K,V,U> {
6288	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
6289	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6290	>	U result;
6291	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
6292	>	MapReduceEntriesTask
6293	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6294	>	MapReduceEntriesTask<K,V,U> nextRight,
6295	>	Function<Map.Entry<K,V>, ? extends U> transformer,
6296	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6297	>	super(m, p, b); this.nextRight = nextRight;
6298	>	this.transformer = transformer;
6299	>	this.reducer = reducer;
6300	>	}
6301	>	public final U getRawResult() { return result; }
6302	>	@SuppressWarnings("unchecked") public final void compute() {
6303	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
6304	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6305	>	if ((transformer = this.transformer) != null &&
6306	>	(reducer = this.reducer) != null) {
6307	>	for (int b; (b = preSplit()) > 0;)
6308	>	(rights = new MapReduceEntriesTask<K,V,U>
6309	>	(map, this, b, rights, transformer, reducer)).fork();
6310	>	U r = null, u;
6311	>	V v;
6312	>	while ((v = advanceValue()) != null) {
6313	>	if ((u = transformer.apply(entryFor(nextKey,
6314	>	v))) != null)
6315	>	r = (r == null) ? u : reducer.apply(r, u);
6316	>	}
6317	>	result = r;
6318	>	CountedCompleter<?> c;
6319	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6320	>	MapReduceEntriesTask<K,V,U>
6321	>	t = (MapReduceEntriesTask<K,V,U>)c,
6322	>	s = t.rights;
6323	>	while (s != null) {
6324	>	U tr, sr;
6325	>	if ((sr = s.result) != null)
6326	>	t.result = (((tr = t.result) == null) ? sr :
6327	>	reducer.apply(tr, sr));
6328	>	s = t.rights = s.nextRight;
6329	>	}
6330	>	}
6331	>	}
6332	>	}
6333	>	}
6334	>
6335	>	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6336	>	extends Traverser<K,V,U> {
6337	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
6338	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6339	>	U result;
6340	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
6341	>	MapReduceMappingsTask
6342	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6343	>	MapReduceMappingsTask<K,V,U> nextRight,
6344	>	BiFunction<? super K, ? super V, ? extends U> transformer,
6345	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6346	>	super(m, p, b); this.nextRight = nextRight;
6347	>	this.transformer = transformer;
6348	>	this.reducer = reducer;
6349	>	}
6350	>	public final U getRawResult() { return result; }
6351	>	@SuppressWarnings("unchecked") public final void compute() {
6352	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
6353	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6354	>	if ((transformer = this.transformer) != null &&
6355	>	(reducer = this.reducer) != null) {
6356	>	for (int b; (b = preSplit()) > 0;)
6357	>	(rights = new MapReduceMappingsTask<K,V,U>
6358	>	(map, this, b, rights, transformer, reducer)).fork();
6359	>	U r = null, u;
6360	>	V v;
6361	>	while ((v = advanceValue()) != null) {
6362	>	if ((u = transformer.apply(nextKey, v)) != null)
6363	>	r = (r == null) ? u : reducer.apply(r, u);
6364	>	}
6365	>	result = r;
6366	>	CountedCompleter<?> c;
6367	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6368	>	MapReduceMappingsTask<K,V,U>
6369	>	t = (MapReduceMappingsTask<K,V,U>)c,
6370	>	s = t.rights;
6371	>	while (s != null) {
6372	>	U tr, sr;
6373	>	if ((sr = s.result) != null)
6374	>	t.result = (((tr = t.result) == null) ? sr :
6375	>	reducer.apply(tr, sr));
6376	>	s = t.rights = s.nextRight;
6377	>	}
6378	>	}
6379	>	}
6380	>	}
6381	>	}
6382	>
6383	>	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6384	>	extends Traverser<K,V,Double> {
6385	>	final ToDoubleFunction<? super K> transformer;
6386	>	final DoubleBinaryOperator reducer;
6387	>	final double basis;
6388	>	double result;
6389	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6390	>	MapReduceKeysToDoubleTask
6391	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6392	>	MapReduceKeysToDoubleTask<K,V> nextRight,
6393	>	ToDoubleFunction<? super K> transformer,
6394	>	double basis,
6395	>	DoubleBinaryOperator reducer) {
6396	>	super(m, p, b); this.nextRight = nextRight;
6397	>	this.transformer = transformer;
6398	>	this.basis = basis; this.reducer = reducer;
6399	>	}
6400	>	public final Double getRawResult() { return result; }
6401	>	@SuppressWarnings("unchecked") public final void compute() {
6402	>	final ToDoubleFunction<? super K> transformer;
6403	>	final DoubleBinaryOperator reducer;
6404	>	if ((transformer = this.transformer) != null &&
6405	>	(reducer = this.reducer) != null) {
6406	>	double r = this.basis;
6407	>	for (int b; (b = preSplit()) > 0;)
6408	>	(rights = new MapReduceKeysToDoubleTask<K,V>
6409	>	(map, this, b, rights, transformer, r, reducer)).fork();
6410	>	K k;
6411	>	while ((k = advanceKey()) != null)
6412	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(k));
6413	>	result = r;
6414	>	CountedCompleter<?> c;
6415	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6416	>	MapReduceKeysToDoubleTask<K,V>
6417	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
6418	>	s = t.rights;
6419	>	while (s != null) {
6420	>	t.result = reducer.applyAsDouble(t.result, s.result);
6421	>	s = t.rights = s.nextRight;
6422	>	}
6423	>	}
6424	>	}
6425	>	}
6426	>	}
6427	>
6428	>	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6429	>	extends Traverser<K,V,Double> {
6430	>	final ToDoubleFunction<? super V> transformer;
6431	>	final DoubleBinaryOperator reducer;
6432	>	final double basis;
6433	>	double result;
6434	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6435	>	MapReduceValuesToDoubleTask
6436	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6437	>	MapReduceValuesToDoubleTask<K,V> nextRight,
6438	>	ToDoubleFunction<? super V> transformer,
6439	>	double basis,
6440	>	DoubleBinaryOperator reducer) {
6441	>	super(m, p, b); this.nextRight = nextRight;
6442	>	this.transformer = transformer;
6443	>	this.basis = basis; this.reducer = reducer;
6444	>	}
6445	>	public final Double getRawResult() { return result; }
6446	>	@SuppressWarnings("unchecked") public final void compute() {
6447	>	final ToDoubleFunction<? super V> transformer;
6448	>	final DoubleBinaryOperator reducer;
6449	>	if ((transformer = this.transformer) != null &&
6450	>	(reducer = this.reducer) != null) {
6451	>	double r = this.basis;
6452	>	for (int b; (b = preSplit()) > 0;)
6453	>	(rights = new MapReduceValuesToDoubleTask<K,V>
6454	>	(map, this, b, rights, transformer, r, reducer)).fork();
6455	>	V v;
6456	>	while ((v = advanceValue()) != null)
6457	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
6458	>	result = r;
6459	>	CountedCompleter<?> c;
6460	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6461	>	MapReduceValuesToDoubleTask<K,V>
6462	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
6463	>	s = t.rights;
6464	>	while (s != null) {
6465	>	t.result = reducer.applyAsDouble(t.result, s.result);
6466	>	s = t.rights = s.nextRight;
6467	>	}
6468	>	}
6469	>	}
6470	>	}
6471	>	}
6472	>
6473	>	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6474	>	extends Traverser<K,V,Double> {
6475	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6476	>	final DoubleBinaryOperator reducer;
6477	>	final double basis;
6478	>	double result;
6479	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6480	>	MapReduceEntriesToDoubleTask
6481	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6482	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
6483	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
6484	>	double basis,
6485	>	DoubleBinaryOperator reducer) {
6486	>	super(m, p, b); this.nextRight = nextRight;
6487	>	this.transformer = transformer;
6488	>	this.basis = basis; this.reducer = reducer;
6489	>	}
6490	>	public final Double getRawResult() { return result; }
6491	>	@SuppressWarnings("unchecked") public final void compute() {
6492	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6493	>	final DoubleBinaryOperator reducer;
6494	>	if ((transformer = this.transformer) != null &&
6495	>	(reducer = this.reducer) != null) {
6496	>	double r = this.basis;
6497	>	for (int b; (b = preSplit()) > 0;)
6498	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
6499	>	(map, this, b, rights, transformer, r, reducer)).fork();
6500	>	V v;
6501	>	while ((v = advanceValue()) != null)
6502	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(nextKey,
6503	>	v)));
6504	>	result = r;
6505	>	CountedCompleter<?> c;
6506	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6507	>	MapReduceEntriesToDoubleTask<K,V>
6508	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
6509	>	s = t.rights;
6510	>	while (s != null) {
6511	>	t.result = reducer.applyAsDouble(t.result, s.result);
6512	>	s = t.rights = s.nextRight;
6513	>	}
6514	>	}
6515	>	}
6516	>	}
6517	>	}
6518	>
6519	>	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6520	>	extends Traverser<K,V,Double> {
6521	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
6522	>	final DoubleBinaryOperator reducer;
6523	>	final double basis;
6524	>	double result;
6525	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6526	>	MapReduceMappingsToDoubleTask
6527	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6528	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
6529	>	ToDoubleBiFunction<? super K, ? super V> transformer,
6530	>	double basis,
6531	>	DoubleBinaryOperator reducer) {
6532	>	super(m, p, b); this.nextRight = nextRight;
6533	>	this.transformer = transformer;
6534	>	this.basis = basis; this.reducer = reducer;
6535	>	}
6536	>	public final Double getRawResult() { return result; }
6537	>	@SuppressWarnings("unchecked") public final void compute() {
6538	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
6539	>	final DoubleBinaryOperator reducer;
6540	>	if ((transformer = this.transformer) != null &&
6541	>	(reducer = this.reducer) != null) {
6542	>	double r = this.basis;
6543	>	for (int b; (b = preSplit()) > 0;)
6544	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
6545	>	(map, this, b, rights, transformer, r, reducer)).fork();
6546	>	V v;
6547	>	while ((v = advanceValue()) != null)
6548	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(nextKey, v));
6549	>	result = r;
6550	>	CountedCompleter<?> c;
6551	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6552	>	MapReduceMappingsToDoubleTask<K,V>
6553	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
6554	>	s = t.rights;
6555	>	while (s != null) {
6556	>	t.result = reducer.applyAsDouble(t.result, s.result);
6557	>	s = t.rights = s.nextRight;
6558	>	}
6559	>	}
6560	>	}
6561	>	}
6562	>	}
6563	>
6564	>	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6565	>	extends Traverser<K,V,Long> {
6566	>	final ToLongFunction<? super K> transformer;
6567	>	final LongBinaryOperator reducer;
6568	>	final long basis;
6569	>	long result;
6570	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
6571	>	MapReduceKeysToLongTask
6572	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6573	>	MapReduceKeysToLongTask<K,V> nextRight,
6574	>	ToLongFunction<? super K> transformer,
6575	>	long basis,
6576	>	LongBinaryOperator reducer) {
6577	>	super(m, p, b); this.nextRight = nextRight;
6578	>	this.transformer = transformer;
6579	>	this.basis = basis; this.reducer = reducer;
6580	>	}
6581	>	public final Long getRawResult() { return result; }
6582	>	@SuppressWarnings("unchecked") public final void compute() {
6583	>	final ToLongFunction<? super K> transformer;
6584	>	final LongBinaryOperator reducer;
6585	>	if ((transformer = this.transformer) != null &&
6586	>	(reducer = this.reducer) != null) {
6587	>	long r = this.basis;
6588	>	for (int b; (b = preSplit()) > 0;)
6589	>	(rights = new MapReduceKeysToLongTask<K,V>
6590	>	(map, this, b, rights, transformer, r, reducer)).fork();
6591	>	K k;
6592	>	while ((k = advanceKey()) != null)
6593	>	r = reducer.applyAsLong(r, transformer.applyAsLong(k));
6594	>	result = r;
6595	>	CountedCompleter<?> c;
6596	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6597	>	MapReduceKeysToLongTask<K,V>
6598	>	t = (MapReduceKeysToLongTask<K,V>)c,
6599	>	s = t.rights;
6600	>	while (s != null) {
6601	>	t.result = reducer.applyAsLong(t.result, s.result);
6602	>	s = t.rights = s.nextRight;
6603	>	}
6604	>	}
6605	>	}
6606	>	}
6607	>	}
6608	>
6609	>	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6610	>	extends Traverser<K,V,Long> {
6611	>	final ToLongFunction<? super V> transformer;
6612	>	final LongBinaryOperator reducer;
6613	>	final long basis;
6614	>	long result;
6615	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
6616	>	MapReduceValuesToLongTask
6617	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6618	>	MapReduceValuesToLongTask<K,V> nextRight,
6619	>	ToLongFunction<? super V> transformer,
6620	>	long basis,
6621	>	LongBinaryOperator reducer) {
6622	>	super(m, p, b); this.nextRight = nextRight;
6623	>	this.transformer = transformer;
6624	>	this.basis = basis; this.reducer = reducer;
6625	>	}
6626	>	public final Long getRawResult() { return result; }
6627	>	@SuppressWarnings("unchecked") public final void compute() {
6628	>	final ToLongFunction<? super V> transformer;
6629	>	final LongBinaryOperator reducer;
6630	>	if ((transformer = this.transformer) != null &&
6631	>	(reducer = this.reducer) != null) {
6632	>	long r = this.basis;
6633	>	for (int b; (b = preSplit()) > 0;)
6634	>	(rights = new MapReduceValuesToLongTask<K,V>
6635	>	(map, this, b, rights, transformer, r, reducer)).fork();
6636	>	V v;
6637	>	while ((v = advanceValue()) != null)
6638	>	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
6639	>	result = r;
6640	>	CountedCompleter<?> c;
6641	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6642	>	MapReduceValuesToLongTask<K,V>
6643	>	t = (MapReduceValuesToLongTask<K,V>)c,
6644	>	s = t.rights;
6645	>	while (s != null) {
6646	>	t.result = reducer.applyAsLong(t.result, s.result);
6647	>	s = t.rights = s.nextRight;
6648	>	}
6649	>	}
6650	>	}
6651	>	}
6652	>	}
6653	>
6654	>	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6655	>	extends Traverser<K,V,Long> {
6656	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6657	>	final LongBinaryOperator reducer;
6658	>	final long basis;
6659	>	long result;
6660	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6661	>	MapReduceEntriesToLongTask
6662	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6663	>	MapReduceEntriesToLongTask<K,V> nextRight,
6664	>	ToLongFunction<Map.Entry<K,V>> transformer,
6665	>	long basis,
6666	>	LongBinaryOperator reducer) {
6667	>	super(m, p, b); this.nextRight = nextRight;
6668	>	this.transformer = transformer;
6669	>	this.basis = basis; this.reducer = reducer;
6670	>	}
6671	>	public final Long getRawResult() { return result; }
6672	>	@SuppressWarnings("unchecked") public final void compute() {
6673	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6674	>	final LongBinaryOperator reducer;
6675	>	if ((transformer = this.transformer) != null &&
6676	>	(reducer = this.reducer) != null) {
6677	>	long r = this.basis;
6678	>	for (int b; (b = preSplit()) > 0;)
6679	>	(rights = new MapReduceEntriesToLongTask<K,V>
6680	>	(map, this, b, rights, transformer, r, reducer)).fork();
6681	>	V v;
6682	>	while ((v = advanceValue()) != null)
6683	>	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(nextKey, v)));
6684	>	result = r;
6685	>	CountedCompleter<?> c;
6686	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6687	>	MapReduceEntriesToLongTask<K,V>
6688	>	t = (MapReduceEntriesToLongTask<K,V>)c,
6689	>	s = t.rights;
6690	>	while (s != null) {
6691	>	t.result = reducer.applyAsLong(t.result, s.result);
6692	>	s = t.rights = s.nextRight;
6693	>	}
6694	>	}
6695	>	}
6696	>	}
6697	>	}
6698	>
6699	>	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6700	>	extends Traverser<K,V,Long> {
6701	>	final ToLongBiFunction<? super K, ? super V> transformer;
6702	>	final LongBinaryOperator reducer;
6703	>	final long basis;
6704	>	long result;
6705	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6706	>	MapReduceMappingsToLongTask
6707	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6708	>	MapReduceMappingsToLongTask<K,V> nextRight,
6709	>	ToLongBiFunction<? super K, ? super V> transformer,
6710	>	long basis,
6711	>	LongBinaryOperator reducer) {
6712	>	super(m, p, b); this.nextRight = nextRight;
6713	>	this.transformer = transformer;
6714	>	this.basis = basis; this.reducer = reducer;
6715	>	}
6716	>	public final Long getRawResult() { return result; }
6717	>	@SuppressWarnings("unchecked") public final void compute() {
6718	>	final ToLongBiFunction<? super K, ? super V> transformer;
6719	>	final LongBinaryOperator reducer;
6720	>	if ((transformer = this.transformer) != null &&
6721	>	(reducer = this.reducer) != null) {
6722	>	long r = this.basis;
6723	>	for (int b; (b = preSplit()) > 0;)
6724	>	(rights = new MapReduceMappingsToLongTask<K,V>
6725	>	(map, this, b, rights, transformer, r, reducer)).fork();
6726	>	V v;
6727	>	while ((v = advanceValue()) != null)
6728	>	r = reducer.applyAsLong(r, transformer.applyAsLong(nextKey, v));
6729	>	result = r;
6730	>	CountedCompleter<?> c;
6731	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6732	>	MapReduceMappingsToLongTask<K,V>
6733	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6734	>	s = t.rights;
6735	>	while (s != null) {
6736	>	t.result = reducer.applyAsLong(t.result, s.result);
6737	>	s = t.rights = s.nextRight;
6738	>	}
6739	>	}
6740	>	}
6741	>	}
6742	>	}
6743	>
6744	>	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6745	>	extends Traverser<K,V,Integer> {
6746	>	final ToIntFunction<? super K> transformer;
6747	>	final IntBinaryOperator reducer;
6748	>	final int basis;
6749	>	int result;
6750	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6751	>	MapReduceKeysToIntTask
6752	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6753	>	MapReduceKeysToIntTask<K,V> nextRight,
6754	>	ToIntFunction<? super K> transformer,
6755	>	int basis,
6756	>	IntBinaryOperator reducer) {
6757	>	super(m, p, b); this.nextRight = nextRight;
6758	>	this.transformer = transformer;
6759	>	this.basis = basis; this.reducer = reducer;
6760	>	}
6761	>	public final Integer getRawResult() { return result; }
6762	>	@SuppressWarnings("unchecked") public final void compute() {
6763	>	final ToIntFunction<? super K> transformer;
6764	>	final IntBinaryOperator reducer;
6765	>	if ((transformer = this.transformer) != null &&
6766	>	(reducer = this.reducer) != null) {
6767	>	int r = this.basis;
6768	>	for (int b; (b = preSplit()) > 0;)
6769	>	(rights = new MapReduceKeysToIntTask<K,V>
6770	>	(map, this, b, rights, transformer, r, reducer)).fork();
6771	>	K k;
6772	>	while ((k = advanceKey()) != null)
6773	>	r = reducer.applyAsInt(r, transformer.applyAsInt(k));
6774	>	result = r;
6775	>	CountedCompleter<?> c;
6776	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6777	>	MapReduceKeysToIntTask<K,V>
6778	>	t = (MapReduceKeysToIntTask<K,V>)c,
6779	>	s = t.rights;
6780	>	while (s != null) {
6781	>	t.result = reducer.applyAsInt(t.result, s.result);
6782	>	s = t.rights = s.nextRight;
6783	>	}
6784	>	}
6785	>	}
6786	>	}
6787	>	}
6788	>
6789	>	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6790	>	extends Traverser<K,V,Integer> {
6791	>	final ToIntFunction<? super V> transformer;
6792	>	final IntBinaryOperator reducer;
6793	>	final int basis;
6794	>	int result;
6795	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6796	>	MapReduceValuesToIntTask
6797	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6798	>	MapReduceValuesToIntTask<K,V> nextRight,
6799	>	ToIntFunction<? super V> transformer,
6800	>	int basis,
6801	>	IntBinaryOperator reducer) {
6802	>	super(m, p, b); this.nextRight = nextRight;
6803	>	this.transformer = transformer;
6804	>	this.basis = basis; this.reducer = reducer;
6805	>	}
6806	>	public final Integer getRawResult() { return result; }
6807	>	@SuppressWarnings("unchecked") public final void compute() {
6808	>	final ToIntFunction<? super V> transformer;
6809	>	final IntBinaryOperator reducer;
6810	>	if ((transformer = this.transformer) != null &&
6811	>	(reducer = this.reducer) != null) {
6812	>	int r = this.basis;
6813	>	for (int b; (b = preSplit()) > 0;)
6814	>	(rights = new MapReduceValuesToIntTask<K,V>
6815	>	(map, this, b, rights, transformer, r, reducer)).fork();
6816	>	V v;
6817	>	while ((v = advanceValue()) != null)
6818	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
6819	>	result = r;
6820	>	CountedCompleter<?> c;
6821	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6822	>	MapReduceValuesToIntTask<K,V>
6823	>	t = (MapReduceValuesToIntTask<K,V>)c,
6824	>	s = t.rights;
6825	>	while (s != null) {
6826	>	t.result = reducer.applyAsInt(t.result, s.result);
6827	>	s = t.rights = s.nextRight;
6828	>	}
6829	>	}
6830	>	}
6831	>	}
6832	>	}
6833	>
6834	>	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6835	>	extends Traverser<K,V,Integer> {
6836	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6837	>	final IntBinaryOperator reducer;
6838	>	final int basis;
6839	>	int result;
6840	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6841	>	MapReduceEntriesToIntTask
6842	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6843	>	MapReduceEntriesToIntTask<K,V> nextRight,
6844	>	ToIntFunction<Map.Entry<K,V>> transformer,
6845	>	int basis,
6846	>	IntBinaryOperator reducer) {
6847	>	super(m, p, b); this.nextRight = nextRight;
6848	>	this.transformer = transformer;
6849	>	this.basis = basis; this.reducer = reducer;
6850	>	}
6851	>	public final Integer getRawResult() { return result; }
6852	>	@SuppressWarnings("unchecked") public final void compute() {
6853	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6854	>	final IntBinaryOperator reducer;
6855	>	if ((transformer = this.transformer) != null &&
6856	>	(reducer = this.reducer) != null) {
6857	>	int r = this.basis;
6858	>	for (int b; (b = preSplit()) > 0;)
6859	>	(rights = new MapReduceEntriesToIntTask<K,V>
6860	>	(map, this, b, rights, transformer, r, reducer)).fork();
6861	>	V v;
6862	>	while ((v = advanceValue()) != null)
6863	>	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(nextKey,
6864	>	v)));
6865	>	result = r;
6866	>	CountedCompleter<?> c;
6867	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6868	>	MapReduceEntriesToIntTask<K,V>
6869	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6870	>	s = t.rights;
6871	>	while (s != null) {
6872	>	t.result = reducer.applyAsInt(t.result, s.result);
6873	>	s = t.rights = s.nextRight;
6874	>	}
6875	>	}
6876	>	}
6877	>	}
6878	>	}
6879	>
6880	>	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6881	>	extends Traverser<K,V,Integer> {
6882	>	final ToIntBiFunction<? super K, ? super V> transformer;
6883	>	final IntBinaryOperator reducer;
6884	>	final int basis;
6885	>	int result;
6886	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6887	>	MapReduceMappingsToIntTask
6888	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6889	>	MapReduceMappingsToIntTask<K,V> nextRight,
6890	>	ToIntBiFunction<? super K, ? super V> transformer,
6891	>	int basis,
6892	>	IntBinaryOperator reducer) {
6893	>	super(m, p, b); this.nextRight = nextRight;
6894	>	this.transformer = transformer;
6895	>	this.basis = basis; this.reducer = reducer;
6896	>	}
6897	>	public final Integer getRawResult() { return result; }
6898	>	@SuppressWarnings("unchecked") public final void compute() {
6899	>	final ToIntBiFunction<? super K, ? super V> transformer;
6900	>	final IntBinaryOperator reducer;
6901	>	if ((transformer = this.transformer) != null &&
6902	>	(reducer = this.reducer) != null) {
6903	>	int r = this.basis;
6904	>	for (int b; (b = preSplit()) > 0;)
6905	>	(rights = new MapReduceMappingsToIntTask<K,V>
6906	>	(map, this, b, rights, transformer, r, reducer)).fork();
6907	>	V v;
6908	>	while ((v = advanceValue()) != null)
6909	>	r = reducer.applyAsInt(r, transformer.applyAsInt(nextKey, v));
6910	>	result = r;
6911	>	CountedCompleter<?> c;
6912	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6913	>	MapReduceMappingsToIntTask<K,V>
6914	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6915	>	s = t.rights;
6916	>	while (s != null) {
6917	>	t.result = reducer.applyAsInt(t.result, s.result);
6918	>	s = t.rights = s.nextRight;
6919	>	}
6920	>	}
6921	>	}
6922		}
6923		}
6924
6925		// Unsafe mechanics
6926	<	private static final sun.misc.Unsafe UNSAFE;
6927	<	private static final long SBASE;
6928	<	private static final int SSHIFT;
6929	<	private static final long TBASE;
6930	<	private static final int TSHIFT;
6926	>	private static final sun.misc.Unsafe U;
6927	>	private static final long SIZECTL;
6928	>	private static final long TRANSFERINDEX;
6929	>	private static final long TRANSFERORIGIN;
6930	>	private static final long BASECOUNT;
6931	>	private static final long CELLSBUSY;
6932	>	private static final long CELLVALUE;
6933	>	private static final long ABASE;
6934	>	private static final int ASHIFT;
6935
6936		static {
1474	–	int ss, ts;
6937		try {
6938	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6939	<	Class tc = HashEntry[].class;
6940	<	Class sc = Segment[].class;
6941	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6942	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6943	<	ts = UNSAFE.arrayIndexScale(tc);
6944	<	ss = UNSAFE.arrayIndexScale(sc);
6938	>	U = sun.misc.Unsafe.getUnsafe();
6939	>	Class<?> k = ConcurrentHashMap.class;
6940	>	SIZECTL = U.objectFieldOffset
6941	>	(k.getDeclaredField("sizeCtl"));
6942	>	TRANSFERINDEX = U.objectFieldOffset
6943	>	(k.getDeclaredField("transferIndex"));
6944	>	TRANSFERORIGIN = U.objectFieldOffset
6945	>	(k.getDeclaredField("transferOrigin"));
6946	>	BASECOUNT = U.objectFieldOffset
6947	>	(k.getDeclaredField("baseCount"));
6948	>	CELLSBUSY = U.objectFieldOffset
6949	>	(k.getDeclaredField("cellsBusy"));
6950	>	Class<?> ck = Cell.class;
6951	>	CELLVALUE = U.objectFieldOffset
6952	>	(ck.getDeclaredField("value"));
6953	>	Class<?> sc = Node[].class;
6954	>	ABASE = U.arrayBaseOffset(sc);
6955	>	int scale = U.arrayIndexScale(sc);
6956	>	if ((scale & (scale - 1)) != 0)
6957	>	throw new Error("data type scale not a power of two");
6958	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6959		} catch (Exception e) {
6960		throw new Error(e);
6961		}
1486	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1487	–	throw new Error("data type scale not a power of two");
1488	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1489	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6962		}
6963
6964		}

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