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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.115 by jsr166, Fri Dec 2 14:28:17 2011 UTC vs.
Revision 1.202 by jsr166, Thu Apr 11 17:50:12 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.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 67 | Line 219 | import java.io.Serializable;
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
120	<	* be a power of two <= 1<<30 to ensure that entries are indexable
121	<	* 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	<	static final int RETRIES_BEFORE_LOCK = 2;
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 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
170	<	* 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.
687	<	*/
252	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
253	<	/*
254	<	* Segments maintain a table of entry lists that are always
255	<	* kept in a consistent state, so can be read (via volatile
256	<	* reads of segments and tables) without locking.  This
257	<	* requires replicating nodes when necessary during table
258	<	* resizing, so the old lists can be traversed by readers
259	<	* still using old version of table.
260	<	*
261	<	* This class defines only mutative methods requiring locking.
262	<	* Except as noted, the methods of this class perform the
263	<	* per-segment versions of ConcurrentHashMap methods.  (Other
264	<	* methods are integrated directly into ConcurrentHashMap
265	<	* methods.) These mutative methods use a form of controlled
266	<	* spinning on contention via methods scanAndLock and
267	<	* scanAndLockForPut. These intersperse tryLocks with
268	<	* traversals to locate nodes.  The main benefit is to absorb
269	<	* cache misses (which are very common for hash tables) while
270	<	* obtaining locks so that traversal is faster once
271	<	* acquired. We do not actually use the found nodes since they
272	<	* must be re-acquired under lock anyway to ensure sequential
273	<	* consistency of updates (and in any case may be undetectably
274	<	* stale), but they will normally be much faster to re-locate.
275	<	* Also, scanAndLockForPut speculatively creates a fresh node
276	<	* to use in put if no node is found.
277	<	*/
278	<
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, else by class
656	>	* names if both comparable but not to each other.  On lookup at a
657	>	* node, if elements are not comparable or compare as 0 then both
658	>	* left and right children may need to be searched in the case of
659	>	* tied hash values. (This corresponds to the full list search
660	>	* that would be necessary if all elements were non-Comparable and
661	>	* had tied hashes.)  The red-black balancing code is updated from
662	>	* pre-jdk-collections
663	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
664	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
665	>	* Algorithms" (CLR).
666	>	*
667	>	* TreeBins also maintain a separate locking discipline than
668	>	* regular bins. Because they are forwarded via special MOVED
669	>	* nodes at bin heads (which can never change once established),
670	>	* we cannot use those nodes as locks. Instead, TreeBin
671	>	* extends AbstractQueuedSynchronizer to support a simple form of
672	>	* read-write lock. For update operations and table validation,
673	>	* the exclusive form of lock behaves in the same way as bin-head
674	>	* locks. However, lookups use shared read-lock mechanics to allow
675	>	* multiple readers in the absence of writers.  Additionally,
676	>	* these lookups do not ever block: While the lock is not
677	>	* available, they proceed along the slow traversal path (via
678	>	* next-pointers) until the lock becomes available or the list is
679	>	* exhausted, whichever comes first. (These cases are not fast,
680	>	* but maximize aggregate expected throughput.)  The AQS mechanics
681	>	* for doing this are straightforward.  The lock state is held as
682	>	* AQS getState().  Read counts are negative; the write count (1)
683	>	* is positive.  There are no signalling preferences among readers
684	>	* and writers. Since we don't need to export full Lock API, we
685	>	* just override the minimal AQS methods and use them directly.
686	>	*/
687	>	static final class TreeBin<V> extends AbstractQueuedSynchronizer {
688		private static final long serialVersionUID = 2249069246763182397L;
689	+	transient TreeNode<V> root;  // root of tree
690	+	transient TreeNode<V> first; // head of next-pointer list
691	+
692	+	/* AQS overrides */
693	+	public final boolean isHeldExclusively() { return getState() > 0; }
694	+	public final boolean tryAcquire(int ignore) {
695	+	if (compareAndSetState(0, 1)) {
696	+	setExclusiveOwnerThread(Thread.currentThread());
697	+	return true;
698	+	}
699	+	return false;
700	+	}
701	+	public final boolean tryRelease(int ignore) {
702	+	setExclusiveOwnerThread(null);
703	+	setState(0);
704	+	return true;
705	+	}
706	+	public final int tryAcquireShared(int ignore) {
707	+	for (int c;;) {
708	+	if ((c = getState()) > 0)
709	+	return -1;
710	+	if (compareAndSetState(c, c -1))
711	+	return 1;
712	+	}
713	+	}
714	+	public final boolean tryReleaseShared(int ignore) {
715	+	int c;
716	+	do {} while (!compareAndSetState(c = getState(), c + 1));
717	+	return c == -1;
718	+	}
719	+
720	+	/** From CLR */
721	+	private void rotateLeft(TreeNode<V> p) {
722	+	if (p != null) {
723	+	TreeNode<V> r = p.right, pp, rl;
724	+	if ((rl = p.right = r.left) != null)
725	+	rl.parent = p;
726	+	if ((pp = r.parent = p.parent) == null)
727	+	root = r;
728	+	else if (pp.left == p)
729	+	pp.left = r;
730	+	else
731	+	pp.right = r;
732	+	r.left = p;
733	+	p.parent = r;
734	+	}
735	+	}
736	+
737	+	/** From CLR */
738	+	private void rotateRight(TreeNode<V> p) {
739	+	if (p != null) {
740	+	TreeNode<V> l = p.left, pp, lr;
741	+	if ((lr = p.left = l.right) != null)
742	+	lr.parent = p;
743	+	if ((pp = l.parent = p.parent) == null)
744	+	root = l;
745	+	else if (pp.right == p)
746	+	pp.right = l;
747	+	else
748	+	pp.left = l;
749	+	l.right = p;
750	+	p.parent = l;
751	+	}
752	+	}
753
754		/**
755	<	* The maximum number of times to tryLock in a prescan before
756	<	* possibly blocking on acquire in preparation for a locked
757	<	* segment operation. On multiprocessors, using a bounded
285	<	* number of retries maintains cache acquired while locating
286	<	* nodes.
755	>	* Compares k and x: if k's comparable class (cc) matches x's,
756	>	* uses Comparable.compareTo. Otherwise compares on comparable
757	>	* class name if either exist, else 0.
758		*/
759	<	static final int MAX_SCAN_RETRIES =
760	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
759	>	@SuppressWarnings("unchecked")
760	>	static int cccompare(Class<?> cc, Object k, Object x) {
761	>	Class<?> cx = comparableClassFor(x);
762	>	return ((cc == null) ? ((cx == null) ? 0 : 1) :
763	>	(cx == null) ? -1 :
764	>	(cx == cc) ? ((Comparable<Object>)k).compareTo(x) :
765	>	cc.getName().compareTo(cx.getName()));
766	>	}
767
768		/**
769	<	* The per-segment table. Elements are accessed via
770	<	* entryAt/setEntryAt providing volatile semantics.
769	>	* Returns the TreeNode (or null if not found) for the given
770	>	* key.  A front-end for recursive version.
771		*/
772	<	transient volatile HashEntry<K,V>[] table;
772	>	final TreeNode<V> getTreeNode(int h, Object k) {
773	>	return getTreeNode(h, k, root, comparableClassFor(k));
774	>	}
775
776		/**
777	<	* The number of elements. Accessed only either within locks
778	<	* or among other volatile reads that maintain visibility.
777	>	* Finds or adds a node. A front-end for recursive version
778	>	* @return null if added
779		*/
780	<	transient int count;
780	>	final TreeNode<V> putTreeNode(int h, Object k, V v) {
781	>	return putTreeNode(h, k, v, comparableClassFor(k));
782	>	}
783
784		/**
785	<	* The total number of mutative operations in this segment.
786	<	* Even though this may overflows 32 bits, it provides
306	<	* sufficient accuracy for stability checks in CHM isEmpty()
307	<	* and size() methods.  Accessed only either within locks or
308	<	* among other volatile reads that maintain visibility.
785	>	* Returns the TreeNode (or null if not found) for the given key
786	>	* starting at given root.
787		*/
788	<	transient int modCount;
788	>	@SuppressWarnings("unchecked") final TreeNode<V> getTreeNode
789	>	(int h, Object k, TreeNode<V> p, Class<?> cc) {
790	>	while (p != null) {
791	>	int dir, ph;  Object pk;
792	>	if ((ph = p.hash) != h)
793	>	dir = (h < ph) ? -1 : 1;
794	>	else if ((pk = p.key) == k || k.equals(pk))
795	>	return p;
796	>	else if ((dir = cccompare(cc, k, pk)) == 0) {
797	>	TreeNode<V> r, pl, pr; // check both sides
798	>	if ((pr = p.right) != null && h >= pr.hash &&
799	>	(r = getTreeNode(h, k, pr, cc)) != null)
800	>	return r;
801	>	else if ((pl = p.left) != null && h <= pl.hash)
802	>	dir = -1;
803	>	else // nothing there
804	>	break;
805	>	}
806	>	p = (dir > 0) ? p.right : p.left;
807	>	}
808	>	return null;
809	>	}
810
811		/**
812	<	* The table is rehashed when its size exceeds this threshold.
813	<	* (The value of this field is always <tt>(int)(capacity *
814	<	* loadFactor)</tt>.)
812	>	* Wrapper for getTreeNode used by CHM.get. Tries to obtain
813	>	* read-lock to call getTreeNode, but during failure to get
814	>	* lock, searches along next links.
815		*/
816	<	transient int threshold;
816	>	final V getValue(int h, Object k) {
817	>	Node<V> r = null;
818	>	int c = getState(); // Must read lock state first
819	>	for (Node<V> e = first; e != null; e = e.next) {
820	>	if (c <= 0 && compareAndSetState(c, c - 1)) {
821	>	try {
822	>	r = getTreeNode(h, k, root, comparableClassFor(k));
823	>	} finally {
824	>	releaseShared(0);
825	>	}
826	>	break;
827	>	}
828	>	else if (e.hash == h && k.equals(e.key)) {
829	>	r = e;
830	>	break;
831	>	}
832	>	else
833	>	c = getState();
834	>	}
835	>	return r == null ? null : r.val;
836	>	}
837	>
838
839		/**
840	<	* The load factor for the hash table.  Even though this value
841	<	* is same for all segments, it is replicated to avoid needing
322	<	* links to outer object.
323	<	* @serial
840	>	* recursive add.
841	>	* @return null if added
842		*/
843	<	final float loadFactor;
844	<
845	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
846	<	this.loadFactor = lf;
847	<	this.threshold = threshold;
848	<	this.table = tab;
849	<	}
843	>	@SuppressWarnings("unchecked") final TreeNode<V> putTreeNode
844	>	(int h, Object k, V v, Class<?> cc) {
845	>	TreeNode<V> pp = root, p = null;
846	>	int dir = 0;
847	>	while (pp != null) { // find existing node or leaf to insert at
848	>	int ph;  Object pk;
849	>	p = pp;
850	>	if ((ph = p.hash) != h)
851	>	dir = (h < ph) ? -1 : 1;
852	>	else if ((pk = p.key) == k || k.equals(pk))
853	>	return p;
854	>	else if ((dir = cccompare(cc, k, pk)) == 0) {
855	>	TreeNode<V> r, pr;
856	>	if ((pr = p.right) != null && h >= pr.hash &&
857	>	(r = getTreeNode(h, k, pr, cc)) != null)
858	>	return r;
859	>	else // continue left
860	>	dir = -1;
861	>	}
862	>	pp = (dir > 0) ? p.right : p.left;
863	>	}
864
865	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
866	<	HashEntry<K,V> node = tryLock() ? null :
867	<	scanAndLockForPut(key, hash, value);
868	<	V oldValue;
869	<	try {
870	<	HashEntry<K,V>[] tab = table;
871	<	int index = (tab.length - 1) & hash;
872	<	HashEntry<K,V> first = entryAt(tab, index);
873	<	for (HashEntry<K,V> e = first;;) {
874	<	if (e != null) {
875	<	K k;
876	<	if ((k = e.key) == key ||
877	<	(e.hash == hash && key.equals(k))) {
878	<	oldValue = e.value;
879	<	if (!onlyIfAbsent) {
880	<	e.value = value;
881	<	++modCount;
865	>	TreeNode<V> f = first;
866	>	TreeNode<V> x = first = new TreeNode<V>(h, k, v, f, p);
867	>	if (p == null)
868	>	root = x;
869	>	else { // attach and rebalance; adapted from CLR
870	>	TreeNode<V> xp, xpp;
871	>	if (f != null)
872	>	f.prev = x;
873	>	if (dir <= 0)
874	>	p.left = x;
875	>	else
876	>	p.right = x;
877	>	x.red = true;
878	>	while (x != null && (xp = x.parent) != null && xp.red &&
879	>	(xpp = xp.parent) != null) {
880	>	TreeNode<V> xppl = xpp.left;
881	>	if (xp == xppl) {
882	>	TreeNode<V> y = xpp.right;
883	>	if (y != null && y.red) {
884	>	y.red = false;
885	>	xp.red = false;
886	>	xpp.red = true;
887	>	x = xpp;
888	>	}
889	>	else {
890	>	if (x == xp.right) {
891	>	rotateLeft(x = xp);
892	>	xpp = (xp = x.parent) == null ? null : xp.parent;
893	>	}
894	>	if (xp != null) {
895	>	xp.red = false;
896	>	if (xpp != null) {
897	>	xpp.red = true;
898	>	rotateRight(xpp);
899	>	}
900		}
351	–	break;
901		}
353	–	e = e.next;
902		}
903		else {
904	<	if (node != null)
905	<	node.setNext(first);
906	<	else
907	<	node = new HashEntry<K,V>(hash, key, value, first);
908	<	int c = count + 1;
909	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
910	<	rehash(node);
911	<	else
912	<	setEntryAt(tab, index, node);
913	<	++modCount;
914	<	count = c;
915	<	oldValue = null;
916	<	break;
904	>	TreeNode<V> y = xppl;
905	>	if (y != null && y.red) {
906	>	y.red = false;
907	>	xp.red = false;
908	>	xpp.red = true;
909	>	x = xpp;
910	>	}
911	>	else {
912	>	if (x == xp.left) {
913	>	rotateRight(x = xp);
914	>	xpp = (xp = x.parent) == null ? null : xp.parent;
915	>	}
916	>	if (xp != null) {
917	>	xp.red = false;
918	>	if (xpp != null) {
919	>	xpp.red = true;
920	>	rotateLeft(xpp);
921	>	}
922	>	}
923	>	}
924		}
925		}
926	<	} finally {
927	<	unlock();
926	>	TreeNode<V> r = root;
927	>	if (r != null && r.red)
928	>	r.red = false;
929		}
930	<	return oldValue;
930	>	return null;
931		}
932
933		/**
934	<	* Doubles size of table and repacks entries, also adding the
935	<	* given node to new table
934	>	* Removes the given node, that must be present before this
935	>	* call.  This is messier than typical red-black deletion code
936	>	* because we cannot swap the contents of an interior node
937	>	* with a leaf successor that is pinned by "next" pointers
938	>	* that are accessible independently of lock. So instead we
939	>	* swap the tree linkages.
940		*/
941	<	@SuppressWarnings("unchecked")
942	<	private void rehash(HashEntry<K,V> node) {
943	<	/*
944	<	* Reclassify nodes in each list to new table.  Because we
945	<	* are using power-of-two expansion, the elements from
946	<	* each bin must either stay at same index, or move with a
947	<	* power of two offset. We eliminate unnecessary node
948	<	* creation by catching cases where old nodes can be
949	<	* reused because their next fields won't change.
950	<	* Statistically, at the default threshold, only about
951	<	* one-sixth of them need cloning when a table
952	<	* doubles. The nodes they replace will be garbage
953	<	* collectable as soon as they are no longer referenced by
954	<	* any reader thread that may be in the midst of
955	<	* concurrently traversing table. Entry accesses use plain
956	<	* array indexing because they are followed by volatile
957	<	* table write.
958	<	*/
959	<	HashEntry<K,V>[] oldTable = table;
960	<	int oldCapacity = oldTable.length;
961	<	int newCapacity = oldCapacity << 1;
962	<	threshold = (int)(newCapacity * loadFactor);
963	<	HashEntry<K,V>[] newTable =
964	<	(HashEntry<K,V>[]) new HashEntry<?,?>[newCapacity];
965	<	int sizeMask = newCapacity - 1;
966	<	for (int i = 0; i < oldCapacity ; i++) {
967	<	HashEntry<K,V> e = oldTable[i];
968	<	if (e != null) {
969	<	HashEntry<K,V> next = e.next;
970	<	int idx = e.hash & sizeMask;
411	<	if (next == null)   //  Single node on list
412	<	newTable[idx] = e;
413	<	else { // Reuse consecutive sequence at same slot
414	<	HashEntry<K,V> lastRun = e;
415	<	int lastIdx = idx;
416	<	for (HashEntry<K,V> last = next;
417	<	last != null;
418	<	last = last.next) {
419	<	int k = last.hash & sizeMask;
420	<	if (k != lastIdx) {
421	<	lastIdx = k;
422	<	lastRun = last;
423	<	}
424	<	}
425	<	newTable[lastIdx] = lastRun;
426	<	// Clone remaining nodes
427	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
428	<	V v = p.value;
429	<	int h = p.hash;
430	<	int k = h & sizeMask;
431	<	HashEntry<K,V> n = newTable[k];
432	<	newTable[k] = new HashEntry<K,V>(h, p.key, v, n);
433	<	}
434	<	}
435	<	}
436	<	}
437	<	int nodeIndex = node.hash & sizeMask; // add the new node
438	<	node.setNext(newTable[nodeIndex]);
439	<	newTable[nodeIndex] = node;
440	<	table = newTable;
441	<	}
442	<
443	<	/**
444	<	* Scans for a node containing given key while trying to
445	<	* acquire lock, creating and returning one if not found. Upon
446	<	* return, guarantees that lock is held. Unlike in most
447	<	* methods, calls to method equals are not screened: Since
448	<	* traversal speed doesn't matter, we might as well help warm
449	<	* up the associated code and accesses as well.
450	<	*
451	<	* @return a new node if key not found, else null
452	<	*/
453	<	private HashEntry<K,V> scanAndLockForPut(K key, int hash, V value) {
454	<	HashEntry<K,V> first = entryForHash(this, hash);
455	<	HashEntry<K,V> e = first;
456	<	HashEntry<K,V> node = null;
457	<	int retries = -1; // negative while locating node
458	<	while (!tryLock()) {
459	<	HashEntry<K,V> f; // to recheck first below
460	<	if (retries < 0) {
461	<	if (e == null) {
462	<	if (node == null) // speculatively create node
463	<	node = new HashEntry<K,V>(hash, key, value, null);
464	<	retries = 0;
941	>	final void deleteTreeNode(TreeNode<V> p) {
942	>	TreeNode<V> next = (TreeNode<V>)p.next; // unlink traversal pointers
943	>	TreeNode<V> pred = p.prev;
944	>	if (pred == null)
945	>	first = next;
946	>	else
947	>	pred.next = next;
948	>	if (next != null)
949	>	next.prev = pred;
950	>	TreeNode<V> replacement;
951	>	TreeNode<V> pl = p.left;
952	>	TreeNode<V> pr = p.right;
953	>	if (pl != null && pr != null) {
954	>	TreeNode<V> s = pr, sl;
955	>	while ((sl = s.left) != null) // find successor
956	>	s = sl;
957	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
958	>	TreeNode<V> sr = s.right;
959	>	TreeNode<V> pp = p.parent;
960	>	if (s == pr) { // p was s's direct parent
961	>	p.parent = s;
962	>	s.right = p;
963	>	}
964	>	else {
965	>	TreeNode<V> sp = s.parent;
966	>	if ((p.parent = sp) != null) {
967	>	if (s == sp.left)
968	>	sp.left = p;
969	>	else
970	>	sp.right = p;
971		}
972	<	else if (key.equals(e.key))
973	<	retries = 0;
468	<	else
469	<	e = e.next;
972	>	if ((s.right = pr) != null)
973	>	pr.parent = s;
974		}
975	<	else if (++retries > MAX_SCAN_RETRIES) {
976	<	lock();
977	<	break;
975	>	p.left = null;
976	>	if ((p.right = sr) != null)
977	>	sr.parent = p;
978	>	if ((s.left = pl) != null)
979	>	pl.parent = s;
980	>	if ((s.parent = pp) == null)
981	>	root = s;
982	>	else if (p == pp.left)
983	>	pp.left = s;
984	>	else
985	>	pp.right = s;
986	>	replacement = sr;
987	>	}
988	>	else
989	>	replacement = (pl != null) ? pl : pr;
990	>	TreeNode<V> pp = p.parent;
991	>	if (replacement == null) {
992	>	if (pp == null) {
993	>	root = null;
994	>	return;
995		}
996	<	else if ((retries & 1) == 0 &&
997	<	(f = entryForHash(this, hash)) != first) {
998	<	e = first = f; // re-traverse if entry changed
999	<	retries = -1;
1000	<	}
1001	<	}
1002	<	return node;
996	>	replacement = p;
997	>	}
998	>	else {
999	>	replacement.parent = pp;
1000	>	if (pp == null)
1001	>	root = replacement;
1002	>	else if (p == pp.left)
1003	>	pp.left = replacement;
1004	>	else
1005	>	pp.right = replacement;
1006	>	p.left = p.right = p.parent = null;
1007	>	}
1008	>	if (!p.red) { // rebalance, from CLR
1009	>	TreeNode<V> x = replacement;
1010	>	while (x != null) {
1011	>	TreeNode<V> xp, xpl;
1012	>	if (x.red || (xp = x.parent) == null) {
1013	>	x.red = false;
1014	>	break;
1015	>	}
1016	>	if (x == (xpl = xp.left)) {
1017	>	TreeNode<V> sib = xp.right;
1018	>	if (sib != null && sib.red) {
1019	>	sib.red = false;
1020	>	xp.red = true;
1021	>	rotateLeft(xp);
1022	>	sib = (xp = x.parent) == null ? null : xp.right;
1023	>	}
1024	>	if (sib == null)
1025	>	x = xp;
1026	>	else {
1027	>	TreeNode<V> sl = sib.left, sr = sib.right;
1028	>	if ((sr == null || !sr.red) &&
1029	>	(sl == null || !sl.red)) {
1030	>	sib.red = true;
1031	>	x = xp;
1032	>	}
1033	>	else {
1034	>	if (sr == null || !sr.red) {
1035	>	if (sl != null)
1036	>	sl.red = false;
1037	>	sib.red = true;
1038	>	rotateRight(sib);
1039	>	sib = (xp = x.parent) == null ?
1040	>	null : xp.right;
1041	>	}
1042	>	if (sib != null) {
1043	>	sib.red = (xp == null) ? false : xp.red;
1044	>	if ((sr = sib.right) != null)
1045	>	sr.red = false;
1046	>	}
1047	>	if (xp != null) {
1048	>	xp.red = false;
1049	>	rotateLeft(xp);
1050	>	}
1051	>	x = root;
1052	>	}
1053	>	}
1054	>	}
1055	>	else { // symmetric
1056	>	TreeNode<V> sib = xpl;
1057	>	if (sib != null && sib.red) {
1058	>	sib.red = false;
1059	>	xp.red = true;
1060	>	rotateRight(xp);
1061	>	sib = (xp = x.parent) == null ? null : xp.left;
1062	>	}
1063	>	if (sib == null)
1064	>	x = xp;
1065	>	else {
1066	>	TreeNode<V> sl = sib.left, sr = sib.right;
1067	>	if ((sl == null || !sl.red) &&
1068	>	(sr == null || !sr.red)) {
1069	>	sib.red = true;
1070	>	x = xp;
1071	>	}
1072	>	else {
1073	>	if (sl == null || !sl.red) {
1074	>	if (sr != null)
1075	>	sr.red = false;
1076	>	sib.red = true;
1077	>	rotateLeft(sib);
1078	>	sib = (xp = x.parent) == null ?
1079	>	null : xp.left;
1080	>	}
1081	>	if (sib != null) {
1082	>	sib.red = (xp == null) ? false : xp.red;
1083	>	if ((sl = sib.left) != null)
1084	>	sl.red = false;
1085	>	}
1086	>	if (xp != null) {
1087	>	xp.red = false;
1088	>	rotateRight(xp);
1089	>	}
1090	>	x = root;
1091	>	}
1092	>	}
1093	>	}
1094	>	}
1095	>	}
1096	>	if (p == replacement && (pp = p.parent) != null) {
1097	>	if (p == pp.left) // detach pointers
1098	>	pp.left = null;
1099	>	else if (p == pp.right)
1100	>	pp.right = null;
1101	>	p.parent = null;
1102	>	}
1103		}
1104	+	}
1105
1106	<	/**
1107	<	* Scans for a node containing the given key while trying to
1108	<	* acquire lock for a remove or replace operation. Upon
1109	<	* return, guarantees that lock is held.  Note that we must
1110	<	* lock even if the key is not found, to ensure sequential
1111	<	* consistency of updates.
1112	<	*/
1113	<	private void scanAndLock(Object key, int hash) {
1114	<	// similar to but simpler than scanAndLockForPut
1115	<	HashEntry<K,V> first = entryForHash(this, hash);
1116	<	HashEntry<K,V> e = first;
1117	<	int retries = -1;
1118	<	while (!tryLock()) {
1119	<	HashEntry<K,V> f;
1120	<	if (retries < 0) {
1121	<	if (e == null || key.equals(e.key))
1122	<	retries = 0;
1123	<	else
1124	<	e = e.next;
1106	>	/* ---------------- Collision reduction methods -------------- */
1107	>
1108	>	/**
1109	>	* Spreads higher bits to lower, and also forces top bit to 0.
1110	>	* Because the table uses power-of-two masking, sets of hashes
1111	>	* that vary only in bits above the current mask will always
1112	>	* collide. (Among known examples are sets of Float keys holding
1113	>	* consecutive whole numbers in small tables.)  To counter this,
1114	>	* we apply a transform that spreads the impact of higher bits
1115	>	* downward. There is a tradeoff between speed, utility, and
1116	>	* quality of bit-spreading. Because many common sets of hashes
1117	>	* are already reasonably distributed across bits (so don't benefit
1118	>	* from spreading), and because we use trees to handle large sets
1119	>	* of collisions in bins, we don't need excessively high quality.
1120	>	*/
1121	>	private static final int spread(int h) {
1122	>	h ^= (h >>> 18) ^ (h >>> 12);
1123	>	return (h ^ (h >>> 10)) & HASH_BITS;
1124	>	}
1125	>
1126	>	/**
1127	>	* Replaces a list bin with a tree bin if key is comparable.  Call
1128	>	* only when locked.
1129	>	*/
1130	>	private final void replaceWithTreeBin(Node<V>[] tab, int index, Object key) {
1131	>	if (comparableClassFor(key) != null) {
1132	>	TreeBin<V> t = new TreeBin<V>();
1133	>	for (Node<V> e = tabAt(tab, index); e != null; e = e.next)
1134	>	t.putTreeNode(e.hash, e.key, e.val);
1135	>	setTabAt(tab, index, new Node<V>(MOVED, t, null, null));
1136	>	}
1137	>	}
1138	>
1139	>	/* ---------------- Internal access and update methods -------------- */
1140	>
1141	>	/** Implementation for get and containsKey */
1142	>	@SuppressWarnings("unchecked") private final V internalGet(Object k) {
1143	>	int h = spread(k.hashCode());
1144	>	retry: for (Node<V>[] tab = table; tab != null;) {
1145	>	Node<V> e; Object ek; V ev; int eh; // locals to read fields once
1146	>	for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
1147	>	if ((eh = e.hash) < 0) {
1148	>	if ((ek = e.key) instanceof TreeBin)  // search TreeBin
1149	>	return ((TreeBin<V>)ek).getValue(h, k);
1150	>	else {                      // restart with new table
1151	>	tab = (Node<V>[])ek;
1152	>	continue retry;
1153	>	}
1154	>	}
1155	>	else if (eh == h && (ev = e.val) != null &&
1156	>	((ek = e.key) == k || k.equals(ek)))
1157	>	return ev;
1158	>	}
1159	>	break;
1160	>	}
1161	>	return null;
1162	>	}
1163	>
1164	>	/**
1165	>	* Implementation for the four public remove/replace methods:
1166	>	* Replaces node value with v, conditional upon match of cv if
1167	>	* non-null.  If resulting value is null, delete.
1168	>	*/
1169	>	@SuppressWarnings("unchecked") private final V internalReplace
1170	>	(Object k, V v, Object cv) {
1171	>	int h = spread(k.hashCode());
1172	>	V oldVal = null;
1173	>	for (Node<V>[] tab = table;;) {
1174	>	Node<V> f; int i, fh; Object fk;
1175	>	if (tab == null ||
1176	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
1177	>	break;
1178	>	else if ((fh = f.hash) < 0) {
1179	>	if ((fk = f.key) instanceof TreeBin) {
1180	>	TreeBin<V> t = (TreeBin<V>)fk;
1181	>	boolean validated = false;
1182	>	boolean deleted = false;
1183	>	t.acquire(0);
1184	>	try {
1185	>	if (tabAt(tab, i) == f) {
1186	>	validated = true;
1187	>	TreeNode<V> p = t.getTreeNode(h, k);
1188	>	if (p != null) {
1189	>	V pv = p.val;
1190	>	if (cv == null || cv == pv || cv.equals(pv)) {
1191	>	oldVal = pv;
1192	>	if ((p.val = v) == null) {
1193	>	deleted = true;
1194	>	t.deleteTreeNode(p);
1195	>	}
1196	>	}
1197	>	}
1198	>	}
1199	>	} finally {
1200	>	t.release(0);
1201	>	}
1202	>	if (validated) {
1203	>	if (deleted)
1204	>	addCount(-1L, -1);
1205	>	break;
1206	>	}
1207	>	}
1208	>	else
1209	>	tab = (Node<V>[])fk;
1210	>	}
1211	>	else if (fh != h && f.next == null) // precheck
1212	>	break;                          // rules out possible existence
1213	>	else {
1214	>	boolean validated = false;
1215	>	boolean deleted = false;
1216	>	synchronized (f) {
1217	>	if (tabAt(tab, i) == f) {
1218	>	validated = true;
1219	>	for (Node<V> e = f, pred = null;;) {
1220	>	Object ek; V ev;
1221	>	if (e.hash == h &&
1222	>	((ev = e.val) != null) &&
1223	>	((ek = e.key) == k || k.equals(ek))) {
1224	>	if (cv == null || cv == ev || cv.equals(ev)) {
1225	>	oldVal = ev;
1226	>	if ((e.val = v) == null) {
1227	>	deleted = true;
1228	>	Node<V> en = e.next;
1229	>	if (pred != null)
1230	>	pred.next = en;
1231	>	else
1232	>	setTabAt(tab, i, en);
1233	>	}
1234	>	}
1235	>	break;
1236	>	}
1237	>	pred = e;
1238	>	if ((e = e.next) == null)
1239	>	break;
1240	>	}
1241	>	}
1242		}
1243	<	else if (++retries > MAX_SCAN_RETRIES) {
1244	<	lock();
1243	>	if (validated) {
1244	>	if (deleted)
1245	>	addCount(-1L, -1);
1246		break;
1247		}
1248	<	else if ((retries & 1) == 0 &&
1249	<	(f = entryForHash(this, hash)) != first) {
1250	<	e = first = f;
1251	<	retries = -1;
1248	>	}
1249	>	}
1250	>	return oldVal;
1251	>	}
1252	>
1253	>	/*
1254	>	* Internal versions of insertion methods
1255	>	* All have the same basic structure as the first (internalPut):
1256	>	*  1. If table uninitialized, create
1257	>	*  2. If bin empty, try to CAS new node
1258	>	*  3. If bin stale, use new table
1259	>	*  4. if bin converted to TreeBin, validate and relay to TreeBin methods
1260	>	*  5. Lock and validate; if valid, scan and add or update
1261	>	*
1262	>	* The putAll method differs mainly in attempting to pre-allocate
1263	>	* enough table space, and also more lazily performs count updates
1264	>	* and checks.
1265	>	*
1266	>	* Most of the function-accepting methods can't be factored nicely
1267	>	* because they require different functional forms, so instead
1268	>	* sprawl out similar mechanics.
1269	>	*/
1270	>
1271	>	/** Implementation for put and putIfAbsent */
1272	>	@SuppressWarnings("unchecked") private final V internalPut
1273	>	(K k, V v, boolean onlyIfAbsent) {
1274	>	if (k == null || v == null) throw new NullPointerException();
1275	>	int h = spread(k.hashCode());
1276	>	int len = 0;
1277	>	for (Node<V>[] tab = table;;) {
1278	>	int i, fh; Node<V> f; Object fk; V fv;
1279	>	if (tab == null)
1280	>	tab = initTable();
1281	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1282	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null)))
1283	>	break;                   // no lock when adding to empty bin
1284	>	}
1285	>	else if ((fh = f.hash) < 0) {
1286	>	if ((fk = f.key) instanceof TreeBin) {
1287	>	TreeBin<V> t = (TreeBin<V>)fk;
1288	>	V oldVal = null;
1289	>	t.acquire(0);
1290	>	try {
1291	>	if (tabAt(tab, i) == f) {
1292	>	len = 2;
1293	>	TreeNode<V> p = t.putTreeNode(h, k, v);
1294	>	if (p != null) {
1295	>	oldVal = p.val;
1296	>	if (!onlyIfAbsent)
1297	>	p.val = v;
1298	>	}
1299	>	}
1300	>	} finally {
1301	>	t.release(0);
1302	>	}
1303	>	if (len != 0) {
1304	>	if (oldVal != null)
1305	>	return oldVal;
1306	>	break;
1307	>	}
1308	>	}
1309	>	else
1310	>	tab = (Node<V>[])fk;
1311	>	}
1312	>	else if (onlyIfAbsent && fh == h && (fv = f.val) != null &&
1313	>	((fk = f.key) == k || k.equals(fk))) // peek while nearby
1314	>	return fv;
1315	>	else {
1316	>	V oldVal = null;
1317	>	synchronized (f) {
1318	>	if (tabAt(tab, i) == f) {
1319	>	len = 1;
1320	>	for (Node<V> e = f;; ++len) {
1321	>	Object ek; V ev;
1322	>	if (e.hash == h &&
1323	>	(ev = e.val) != null &&
1324	>	((ek = e.key) == k || k.equals(ek))) {
1325	>	oldVal = ev;
1326	>	if (!onlyIfAbsent)
1327	>	e.val = v;
1328	>	break;
1329	>	}
1330	>	Node<V> last = e;
1331	>	if ((e = e.next) == null) {
1332	>	last.next = new Node<V>(h, k, v, null);
1333	>	if (len >= TREE_THRESHOLD)
1334	>	replaceWithTreeBin(tab, i, k);
1335	>	break;
1336	>	}
1337	>	}
1338	>	}
1339	>	}
1340	>	if (len != 0) {
1341	>	if (oldVal != null)
1342	>	return oldVal;
1343	>	break;
1344		}
1345		}
1346		}
1347	+	addCount(1L, len);
1348	+	return null;
1349	+	}
1350
1351	<	/**
1352	<	* Remove; match on key only if value null, else match both.
1353	<	*/
1354	<	final V remove(Object key, int hash, Object value) {
1355	<	if (!tryLock())
1356	<	scanAndLock(key, hash);
1357	<	V oldValue = null;
1358	<	try {
1359	<	HashEntry<K,V>[] tab = table;
1360	<	int index = (tab.length - 1) & hash;
1361	<	HashEntry<K,V> e = entryAt(tab, index);
1362	<	HashEntry<K,V> pred = null;
1363	<	while (e != null) {
1364	<	K k;
1365	<	HashEntry<K,V> next = e.next;
1366	<	if ((k = e.key) == key ||
1367	<	(e.hash == hash && key.equals(k))) {
1368	<	V v = e.value;
1369	<	if (value == null || value == v || value.equals(v)) {
1370	<	if (pred == null)
1371	<	setEntryAt(tab, index, next);
1372	<	else
1373	<	pred.setNext(next);
539	<	++modCount;
540	<	--count;
541	<	oldValue = v;
1351	>	/** Implementation for computeIfAbsent */
1352	>	@SuppressWarnings("unchecked") private final V internalComputeIfAbsent
1353	>	(K k, Function<? super K, ? extends V> mf) {
1354	>	if (k == null || mf == null)
1355	>	throw new NullPointerException();
1356	>	int h = spread(k.hashCode());
1357	>	V val = null;
1358	>	int len = 0;
1359	>	for (Node<V>[] tab = table;;) {
1360	>	Node<V> f; int i; Object fk;
1361	>	if (tab == null)
1362	>	tab = initTable();
1363	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1364	>	Node<V> node = new Node<V>(h, k, null, null);
1365	>	synchronized (node) {
1366	>	if (casTabAt(tab, i, null, node)) {
1367	>	len = 1;
1368	>	try {
1369	>	if ((val = mf.apply(k)) != null)
1370	>	node.val = val;
1371	>	} finally {
1372	>	if (val == null)
1373	>	setTabAt(tab, i, null);
1374		}
1375	+	}
1376	+	}
1377	+	if (len != 0)
1378	+	break;
1379	+	}
1380	+	else if (f.hash < 0) {
1381	+	if ((fk = f.key) instanceof TreeBin) {
1382	+	TreeBin<V> t = (TreeBin<V>)fk;
1383	+	boolean added = false;
1384	+	t.acquire(0);
1385	+	try {
1386	+	if (tabAt(tab, i) == f) {
1387	+	len = 1;
1388	+	TreeNode<V> p = t.getTreeNode(h, k);
1389	+	if (p != null)
1390	+	val = p.val;
1391	+	else if ((val = mf.apply(k)) != null) {
1392	+	added = true;
1393	+	len = 2;
1394	+	t.putTreeNode(h, k, val);
1395	+	}
1396	+	}
1397	+	} finally {
1398	+	t.release(0);
1399	+	}
1400	+	if (len != 0) {
1401	+	if (!added)
1402	+	return val;
1403		break;
1404		}
545	–	pred = e;
546	–	e = next;
1405		}
1406	<	} finally {
1407	<	unlock();
1406	>	else
1407	>	tab = (Node<V>[])fk;
1408	>	}
1409	>	else {
1410	>	for (Node<V> e = f; e != null; e = e.next) { // prescan
1411	>	Object ek; V ev;
1412	>	if (e.hash == h && (ev = e.val) != null &&
1413	>	((ek = e.key) == k || k.equals(ek)))
1414	>	return ev;
1415	>	}
1416	>	boolean added = false;
1417	>	synchronized (f) {
1418	>	if (tabAt(tab, i) == f) {
1419	>	len = 1;
1420	>	for (Node<V> e = f;; ++len) {
1421	>	Object ek; V ev;
1422	>	if (e.hash == h &&
1423	>	(ev = e.val) != null &&
1424	>	((ek = e.key) == k || k.equals(ek))) {
1425	>	val = ev;
1426	>	break;
1427	>	}
1428	>	Node<V> last = e;
1429	>	if ((e = e.next) == null) {
1430	>	if ((val = mf.apply(k)) != null) {
1431	>	added = true;
1432	>	last.next = new Node<V>(h, k, val, null);
1433	>	if (len >= TREE_THRESHOLD)
1434	>	replaceWithTreeBin(tab, i, k);
1435	>	}
1436	>	break;
1437	>	}
1438	>	}
1439	>	}
1440	>	}
1441	>	if (len != 0) {
1442	>	if (!added)
1443	>	return val;
1444	>	break;
1445	>	}
1446		}
551	–	return oldValue;
1447		}
1448	+	if (val != null)
1449	+	addCount(1L, len);
1450	+	return val;
1451	+	}
1452
1453	<	final boolean replace(K key, int hash, V oldValue, V newValue) {
1454	<	if (!tryLock())
1455	<	scanAndLock(key, hash);
1456	<	boolean replaced = false;
1457	<	try {
1458	<	HashEntry<K,V> e;
1459	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1460	<	K k;
1461	<	if ((k = e.key) == key ||
1462	<	(e.hash == hash && key.equals(k))) {
1463	<	if (oldValue.equals(e.value)) {
1464	<	e.value = newValue;
1465	<	++modCount;
1466	<	replaced = true;
1453	>	/** Implementation for compute */
1454	>	@SuppressWarnings("unchecked") private final V internalCompute
1455	>	(K k, boolean onlyIfPresent,
1456	>	BiFunction<? super K, ? super V, ? extends V> mf) {
1457	>	if (k == null || mf == null)
1458	>	throw new NullPointerException();
1459	>	int h = spread(k.hashCode());
1460	>	V val = null;
1461	>	int delta = 0;
1462	>	int len = 0;
1463	>	for (Node<V>[] tab = table;;) {
1464	>	Node<V> f; int i, fh; Object fk;
1465	>	if (tab == null)
1466	>	tab = initTable();
1467	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1468	>	if (onlyIfPresent)
1469	>	break;
1470	>	Node<V> node = new Node<V>(h, k, null, null);
1471	>	synchronized (node) {
1472	>	if (casTabAt(tab, i, null, node)) {
1473	>	try {
1474	>	len = 1;
1475	>	if ((val = mf.apply(k, null)) != null) {
1476	>	node.val = val;
1477	>	delta = 1;
1478	>	}
1479	>	} finally {
1480	>	if (delta == 0)
1481	>	setTabAt(tab, i, null);
1482		}
1483	+	}
1484	+	}
1485	+	if (len != 0)
1486	+	break;
1487	+	}
1488	+	else if ((fh = f.hash) < 0) {
1489	+	if ((fk = f.key) instanceof TreeBin) {
1490	+	TreeBin<V> t = (TreeBin<V>)fk;
1491	+	t.acquire(0);
1492	+	try {
1493	+	if (tabAt(tab, i) == f) {
1494	+	len = 1;
1495	+	TreeNode<V> p = t.getTreeNode(h, k);
1496	+	if (p == null && onlyIfPresent)
1497	+	break;
1498	+	V pv = (p == null) ? null : p.val;
1499	+	if ((val = mf.apply(k, pv)) != null) {
1500	+	if (p != null)
1501	+	p.val = val;
1502	+	else {
1503	+	len = 2;
1504	+	delta = 1;
1505	+	t.putTreeNode(h, k, val);
1506	+	}
1507	+	}
1508	+	else if (p != null) {
1509	+	delta = -1;
1510	+	t.deleteTreeNode(p);
1511	+	}
1512	+	}
1513	+	} finally {
1514	+	t.release(0);
1515	+	}
1516	+	if (len != 0)
1517		break;
1518	+	}
1519	+	else
1520	+	tab = (Node<V>[])fk;
1521	+	}
1522	+	else {
1523	+	synchronized (f) {
1524	+	if (tabAt(tab, i) == f) {
1525	+	len = 1;
1526	+	for (Node<V> e = f, pred = null;; ++len) {
1527	+	Object ek; V ev;
1528	+	if (e.hash == h &&
1529	+	(ev = e.val) != null &&
1530	+	((ek = e.key) == k || k.equals(ek))) {
1531	+	val = mf.apply(k, ev);
1532	+	if (val != null)
1533	+	e.val = val;
1534	+	else {
1535	+	delta = -1;
1536	+	Node<V> en = e.next;
1537	+	if (pred != null)
1538	+	pred.next = en;
1539	+	else
1540	+	setTabAt(tab, i, en);
1541	+	}
1542	+	break;
1543	+	}
1544	+	pred = e;
1545	+	if ((e = e.next) == null) {
1546	+	if (!onlyIfPresent &&
1547	+	(val = mf.apply(k, null)) != null) {
1548	+	pred.next = new Node<V>(h, k, val, null);
1549	+	delta = 1;
1550	+	if (len >= TREE_THRESHOLD)
1551	+	replaceWithTreeBin(tab, i, k);
1552	+	}
1553	+	break;
1554	+	}
1555	+	}
1556		}
1557		}
1558	<	} finally {
1559	<	unlock();
1558	>	if (len != 0)
1559	>	break;
1560		}
575	–	return replaced;
1561		}
1562	+	if (delta != 0)
1563	+	addCount((long)delta, len);
1564	+	return val;
1565	+	}
1566
1567	<	final V replace(K key, int hash, V value) {
1568	<	if (!tryLock())
1569	<	scanAndLock(key, hash);
1570	<	V oldValue = null;
1571	<	try {
1572	<	HashEntry<K,V> e;
1573	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1574	<	K k;
1575	<	if ((k = e.key) == key ||
1576	<	(e.hash == hash && key.equals(k))) {
1577	<	oldValue = e.value;
1578	<	e.value = value;
1579	<	++modCount;
1567	>	/** Implementation for merge */
1568	>	@SuppressWarnings("unchecked") private final V internalMerge
1569	>	(K k, V v, BiFunction<? super V, ? super V, ? extends V> mf) {
1570	>	if (k == null || v == null || mf == null)
1571	>	throw new NullPointerException();
1572	>	int h = spread(k.hashCode());
1573	>	V val = null;
1574	>	int delta = 0;
1575	>	int len = 0;
1576	>	for (Node<V>[] tab = table;;) {
1577	>	int i; Node<V> f; Object fk; V fv;
1578	>	if (tab == null)
1579	>	tab = initTable();
1580	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
1581	>	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1582	>	delta = 1;
1583	>	val = v;
1584	>	break;
1585	>	}
1586	>	}
1587	>	else if (f.hash < 0) {
1588	>	if ((fk = f.key) instanceof TreeBin) {
1589	>	TreeBin<V> t = (TreeBin<V>)fk;
1590	>	t.acquire(0);
1591	>	try {
1592	>	if (tabAt(tab, i) == f) {
1593	>	len = 1;
1594	>	TreeNode<V> p = t.getTreeNode(h, k);
1595	>	val = (p == null) ? v : mf.apply(p.val, v);
1596	>	if (val != null) {
1597	>	if (p != null)
1598	>	p.val = val;
1599	>	else {
1600	>	len = 2;
1601	>	delta = 1;
1602	>	t.putTreeNode(h, k, val);
1603	>	}
1604	>	}
1605	>	else if (p != null) {
1606	>	delta = -1;
1607	>	t.deleteTreeNode(p);
1608	>	}
1609	>	}
1610	>	} finally {
1611	>	t.release(0);
1612	>	}
1613	>	if (len != 0)
1614		break;
1615	+	}
1616	+	else
1617	+	tab = (Node<V>[])fk;
1618	+	}
1619	+	else {
1620	+	synchronized (f) {
1621	+	if (tabAt(tab, i) == f) {
1622	+	len = 1;
1623	+	for (Node<V> e = f, pred = null;; ++len) {
1624	+	Object ek; V ev;
1625	+	if (e.hash == h &&
1626	+	(ev = e.val) != null &&
1627	+	((ek = e.key) == k || k.equals(ek))) {
1628	+	val = mf.apply(ev, v);
1629	+	if (val != null)
1630	+	e.val = val;
1631	+	else {
1632	+	delta = -1;
1633	+	Node<V> en = e.next;
1634	+	if (pred != null)
1635	+	pred.next = en;
1636	+	else
1637	+	setTabAt(tab, i, en);
1638	+	}
1639	+	break;
1640	+	}
1641	+	pred = e;
1642	+	if ((e = e.next) == null) {
1643	+	val = v;
1644	+	pred.next = new Node<V>(h, k, val, null);
1645	+	delta = 1;
1646	+	if (len >= TREE_THRESHOLD)
1647	+	replaceWithTreeBin(tab, i, k);
1648	+	break;
1649	+	}
1650	+	}
1651	+	}
1652	+	}
1653	+	if (len != 0)
1654	+	break;
1655	+	}
1656	+	}
1657	+	if (delta != 0)
1658	+	addCount((long)delta, len);
1659	+	return val;
1660	+	}
1661	+
1662	+	/** Implementation for putAll */
1663	+	@SuppressWarnings("unchecked") private final void internalPutAll
1664	+	(Map<? extends K, ? extends V> m) {
1665	+	tryPresize(m.size());
1666	+	long delta = 0L;     // number of uncommitted additions
1667	+	boolean npe = false; // to throw exception on exit for nulls
1668	+	try {                // to clean up counts on other exceptions
1669	+	for (Map.Entry<?, ? extends V> entry : m.entrySet()) {
1670	+	Object k; V v;
1671	+	if (entry == null || (k = entry.getKey()) == null ||
1672	+	(v = entry.getValue()) == null) {
1673	+	npe = true;
1674	+	break;
1675	+	}
1676	+	int h = spread(k.hashCode());
1677	+	for (Node<V>[] tab = table;;) {
1678	+	int i; Node<V> f; int fh; Object fk;
1679	+	if (tab == null)
1680	+	tab = initTable();
1681	+	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
1682	+	if (casTabAt(tab, i, null, new Node<V>(h, k, v, null))) {
1683	+	++delta;
1684	+	break;
1685	+	}
1686	+	}
1687	+	else if ((fh = f.hash) < 0) {
1688	+	if ((fk = f.key) instanceof TreeBin) {
1689	+	TreeBin<V> t = (TreeBin<V>)fk;
1690	+	boolean validated = false;
1691	+	t.acquire(0);
1692	+	try {
1693	+	if (tabAt(tab, i) == f) {
1694	+	validated = true;
1695	+	TreeNode<V> p = t.getTreeNode(h, k);
1696	+	if (p != null)
1697	+	p.val = v;
1698	+	else {
1699	+	t.putTreeNode(h, k, v);
1700	+	++delta;
1701	+	}
1702	+	}
1703	+	} finally {
1704	+	t.release(0);
1705	+	}
1706	+	if (validated)
1707	+	break;
1708	+	}
1709	+	else
1710	+	tab = (Node<V>[])fk;
1711	+	}
1712	+	else {
1713	+	int len = 0;
1714	+	synchronized (f) {
1715	+	if (tabAt(tab, i) == f) {
1716	+	len = 1;
1717	+	for (Node<V> e = f;; ++len) {
1718	+	Object ek; V ev;
1719	+	if (e.hash == h &&
1720	+	(ev = e.val) != null &&
1721	+	((ek = e.key) == k || k.equals(ek))) {
1722	+	e.val = v;
1723	+	break;
1724	+	}
1725	+	Node<V> last = e;
1726	+	if ((e = e.next) == null) {
1727	+	++delta;
1728	+	last.next = new Node<V>(h, k, v, null);
1729	+	if (len >= TREE_THRESHOLD)
1730	+	replaceWithTreeBin(tab, i, k);
1731	+	break;
1732	+	}
1733	+	}
1734	+	}
1735	+	}
1736	+	if (len != 0) {
1737	+	if (len > 1) {
1738	+	addCount(delta, len);
1739	+	delta = 0L;
1740	+	}
1741	+	break;
1742	+	}
1743		}
1744		}
594	–	} finally {
595	–	unlock();
1745		}
1746	<	return oldValue;
1746	>	} finally {
1747	>	if (delta != 0L)
1748	>	addCount(delta, 2);
1749		}
1750	+	if (npe)
1751	+	throw new NullPointerException();
1752	+	}
1753
1754	<	final void clear() {
1755	<	lock();
1756	<	try {
1757	<	HashEntry<K,V>[] tab = table;
1758	<	for (int i = 0; i < tab.length ; i++)
1759	<	setEntryAt(tab, i, null);
1760	<	++modCount;
1761	<	count = 0;
1762	<	} finally {
1763	<	unlock();
1754	>	/**
1755	>	* Implementation for clear. Steps through each bin, removing all
1756	>	* nodes.
1757	>	*/
1758	>	@SuppressWarnings("unchecked") private final void internalClear() {
1759	>	long delta = 0L; // negative number of deletions
1760	>	int i = 0;
1761	>	Node<V>[] tab = table;
1762	>	while (tab != null && i < tab.length) {
1763	>	Node<V> f = tabAt(tab, i);
1764	>	if (f == null)
1765	>	++i;
1766	>	else if (f.hash < 0) {
1767	>	Object fk;
1768	>	if ((fk = f.key) instanceof TreeBin) {
1769	>	TreeBin<V> t = (TreeBin<V>)fk;
1770	>	t.acquire(0);
1771	>	try {
1772	>	if (tabAt(tab, i) == f) {
1773	>	for (Node<V> p = t.first; p != null; p = p.next) {
1774	>	if (p.val != null) { // (currently always true)
1775	>	p.val = null;
1776	>	--delta;
1777	>	}
1778	>	}
1779	>	t.first = null;
1780	>	t.root = null;
1781	>	++i;
1782	>	}
1783	>	} finally {
1784	>	t.release(0);
1785	>	}
1786	>	}
1787	>	else
1788	>	tab = (Node<V>[])fk;
1789	>	}
1790	>	else {
1791	>	synchronized (f) {
1792	>	if (tabAt(tab, i) == f) {
1793	>	for (Node<V> e = f; e != null; e = e.next) {
1794	>	if (e.val != null) {  // (currently always true)
1795	>	e.val = null;
1796	>	--delta;
1797	>	}
1798	>	}
1799	>	setTabAt(tab, i, null);
1800	>	++i;
1801	>	}
1802	>	}
1803		}
1804		}
1805	+	if (delta != 0L)
1806	+	addCount(delta, -1);
1807		}
1808
1809	<	// Accessing segments
1809	>	/* ---------------- Table Initialization and Resizing -------------- */
1810
1811		/**
1812	<	* Gets the jth element of given segment array (if nonnull) with
1813	<	* volatile element access semantics via Unsafe. (The null check
619	<	* can trigger harmlessly only during deserialization.) Note:
620	<	* because each element of segments array is set only once (using
621	<	* fully ordered writes), some performance-sensitive methods rely
622	<	* on this method only as a recheck upon null reads.
1812	>	* Returns a power of two table size for the given desired capacity.
1813	>	* See Hackers Delight, sec 3.2
1814		*/
1815	<	@SuppressWarnings("unchecked")
1816	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1817	<	long u = (j << SSHIFT) + SBASE;
1818	<	return ss == null ? null :
1819	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1815	>	private static final int tableSizeFor(int c) {
1816	>	int n = c - 1;
1817	>	n |= n >>> 1;
1818	>	n |= n >>> 2;
1819	>	n |= n >>> 4;
1820	>	n |= n >>> 8;
1821	>	n |= n >>> 16;
1822	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1823		}
1824
1825		/**
1826	<	* Returns the segment for the given index, creating it and
1827	<	* recording in segment table (via CAS) if not already present.
1826	>	* Initializes table, using the size recorded in sizeCtl.
1827	>	*/
1828	>	@SuppressWarnings("unchecked") private final Node<V>[] initTable() {
1829	>	Node<V>[] tab; int sc;
1830	>	while ((tab = table) == null) {
1831	>	if ((sc = sizeCtl) < 0)
1832	>	Thread.yield(); // lost initialization race; just spin
1833	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1834	>	try {
1835	>	if ((tab = table) == null) {
1836	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1837	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1838	>	table = tab = (Node<V>[])tb;
1839	>	sc = n - (n >>> 2);
1840	>	}
1841	>	} finally {
1842	>	sizeCtl = sc;
1843	>	}
1844	>	break;
1845	>	}
1846	>	}
1847	>	return tab;
1848	>	}
1849	>
1850	>	/**
1851	>	* Adds to count, and if table is too small and not already
1852	>	* resizing, initiates transfer. If already resizing, helps
1853	>	* perform transfer if work is available.  Rechecks occupancy
1854	>	* after a transfer to see if another resize is already needed
1855	>	* because resizings are lagging additions.
1856		*
1857	<	* @param k the index
1858	<	* @return the segment
1857	>	* @param x the count to add
1858	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
1859		*/
1860	<	@SuppressWarnings("unchecked")
1861	<	private Segment<K,V> ensureSegment(int k) {
1862	<	final Segment<K,V>[] ss = this.segments;
1863	<	long u = (k << SSHIFT) + SBASE; // raw offset
1864	<	Segment<K,V> seg;
1865	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1866	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1867	<	int cap = proto.table.length;
1868	<	float lf = proto.loadFactor;
1869	<	int threshold = (int)(cap * lf);
1870	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry<?,?>[cap];
1871	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1872	<	== null) { // recheck
1873	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1874	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1875	<	== null) {
1876	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1860	>	private final void addCount(long x, int check) {
1861	>	Cell[] as; long b, s;
1862	>	if ((as = counterCells) != null ||
1863	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
1864	>	Cell a; long v; int m;
1865	>	boolean uncontended = true;
1866	>	if (as == null || (m = as.length - 1) < 0 ||
1867	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
1868	>	!(uncontended =
1869	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
1870	>	fullAddCount(x, uncontended);
1871	>	return;
1872	>	}
1873	>	if (check <= 1)
1874	>	return;
1875	>	s = sumCount();
1876	>	}
1877	>	if (check >= 0) {
1878	>	Node<V>[] tab, nt; int sc;
1879	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
1880	>	tab.length < MAXIMUM_CAPACITY) {
1881	>	if (sc < 0) {
1882	>	if (sc == -1 || transferIndex <= transferOrigin ||
1883	>	(nt = nextTable) == null)
1884		break;
1885	+	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
1886	+	transfer(tab, nt);
1887		}
1888	+	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
1889	+	transfer(tab, null);
1890	+	s = sumCount();
1891		}
1892		}
659	–	return seg;
1893		}
1894
662	–	// Hash-based segment and entry accesses
663	–
1895		/**
1896	<	* Gets the segment for the given hash code.
1896	>	* Tries to presize table to accommodate the given number of elements.
1897	>	*
1898	>	* @param size number of elements (doesn't need to be perfectly accurate)
1899		*/
1900	<	@SuppressWarnings("unchecked")
1901	<	private Segment<K,V> segmentForHash(int h) {
1902	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1903	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1900	>	@SuppressWarnings("unchecked") private final void tryPresize(int size) {
1901	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1902	>	tableSizeFor(size + (size >>> 1) + 1);
1903	>	int sc;
1904	>	while ((sc = sizeCtl) >= 0) {
1905	>	Node<V>[] tab = table; int n;
1906	>	if (tab == null || (n = tab.length) == 0) {
1907	>	n = (sc > c) ? sc : c;
1908	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
1909	>	try {
1910	>	if (table == tab) {
1911	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n];
1912	>	table = (Node<V>[])tb;
1913	>	sc = n - (n >>> 2);
1914	>	}
1915	>	} finally {
1916	>	sizeCtl = sc;
1917	>	}
1918	>	}
1919	>	}
1920	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1921	>	break;
1922	>	else if (tab == table &&
1923	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
1924	>	transfer(tab, null);
1925	>	}
1926		}
1927
1928		/**
1929	<	* Gets the table entry for the given segment and hash code.
1929	>	* Moves and/or copies the nodes in each bin to new table. See
1930	>	* above for explanation.
1931		*/
1932	<	@SuppressWarnings("unchecked")
1933	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1934	<	HashEntry<K,V>[] tab;
1935	<	return (seg == null || (tab = seg.table) == null) ? null :
1936	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
1937	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1932	>	@SuppressWarnings("unchecked") private final void transfer
1933	>	(Node<V>[] tab, Node<V>[] nextTab) {
1934	>	int n = tab.length, stride;
1935	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
1936	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
1937	>	if (nextTab == null) {            // initiating
1938	>	try {
1939	>	@SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1];
1940	>	nextTab = (Node<V>[])tb;
1941	>	} catch (Throwable ex) {      // try to cope with OOME
1942	>	sizeCtl = Integer.MAX_VALUE;
1943	>	return;
1944	>	}
1945	>	nextTable = nextTab;
1946	>	transferOrigin = n;
1947	>	transferIndex = n;
1948	>	Node<V> rev = new Node<V>(MOVED, tab, null, null);
1949	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
1950	>	int nextk = (k > stride) ? k - stride : 0;
1951	>	for (int m = nextk; m < k; ++m)
1952	>	nextTab[m] = rev;
1953	>	for (int m = n + nextk; m < n + k; ++m)
1954	>	nextTab[m] = rev;
1955	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
1956	>	}
1957	>	}
1958	>	int nextn = nextTab.length;
1959	>	Node<V> fwd = new Node<V>(MOVED, nextTab, null, null);
1960	>	boolean advance = true;
1961	>	for (int i = 0, bound = 0;;) {
1962	>	int nextIndex, nextBound; Node<V> f; Object fk;
1963	>	while (advance) {
1964	>	if (--i >= bound)
1965	>	advance = false;
1966	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
1967	>	i = -1;
1968	>	advance = false;
1969	>	}
1970	>	else if (U.compareAndSwapInt
1971	>	(this, TRANSFERINDEX, nextIndex,
1972	>	nextBound = (nextIndex > stride ?
1973	>	nextIndex - stride : 0))) {
1974	>	bound = nextBound;
1975	>	i = nextIndex - 1;
1976	>	advance = false;
1977	>	}
1978	>	}
1979	>	if (i < 0 || i >= n || i + n >= nextn) {
1980	>	for (int sc;;) {
1981	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
1982	>	if (sc == -1) {
1983	>	nextTable = null;
1984	>	table = nextTab;
1985	>	sizeCtl = (n << 1) - (n >>> 1);
1986	>	}
1987	>	return;
1988	>	}
1989	>	}
1990	>	}
1991	>	else if ((f = tabAt(tab, i)) == null) {
1992	>	if (casTabAt(tab, i, null, fwd)) {
1993	>	setTabAt(nextTab, i, null);
1994	>	setTabAt(nextTab, i + n, null);
1995	>	advance = true;
1996	>	}
1997	>	}
1998	>	else if (f.hash >= 0) {
1999	>	synchronized (f) {
2000	>	if (tabAt(tab, i) == f) {
2001	>	int runBit = f.hash & n;
2002	>	Node<V> lastRun = f, lo = null, hi = null;
2003	>	for (Node<V> p = f.next; p != null; p = p.next) {
2004	>	int b = p.hash & n;
2005	>	if (b != runBit) {
2006	>	runBit = b;
2007	>	lastRun = p;
2008	>	}
2009	>	}
2010	>	if (runBit == 0)
2011	>	lo = lastRun;
2012	>	else
2013	>	hi = lastRun;
2014	>	for (Node<V> p = f; p != lastRun; p = p.next) {
2015	>	int ph = p.hash;
2016	>	Object pk = p.key; V pv = p.val;
2017	>	if ((ph & n) == 0)
2018	>	lo = new Node<V>(ph, pk, pv, lo);
2019	>	else
2020	>	hi = new Node<V>(ph, pk, pv, hi);
2021	>	}
2022	>	setTabAt(nextTab, i, lo);
2023	>	setTabAt(nextTab, i + n, hi);
2024	>	setTabAt(tab, i, fwd);
2025	>	advance = true;
2026	>	}
2027	>	}
2028	>	}
2029	>	else if ((fk = f.key) instanceof TreeBin) {
2030	>	TreeBin<V> t = (TreeBin<V>)fk;
2031	>	t.acquire(0);
2032	>	try {
2033	>	if (tabAt(tab, i) == f) {
2034	>	TreeBin<V> lt = new TreeBin<V>();
2035	>	TreeBin<V> ht = new TreeBin<V>();
2036	>	int lc = 0, hc = 0;
2037	>	for (Node<V> e = t.first; e != null; e = e.next) {
2038	>	int h = e.hash;
2039	>	Object k = e.key; V v = e.val;
2040	>	if ((h & n) == 0) {
2041	>	++lc;
2042	>	lt.putTreeNode(h, k, v);
2043	>	}
2044	>	else {
2045	>	++hc;
2046	>	ht.putTreeNode(h, k, v);
2047	>	}
2048	>	}
2049	>	Node<V> ln, hn; // throw away trees if too small
2050	>	if (lc < TREE_THRESHOLD) {
2051	>	ln = null;
2052	>	for (Node<V> p = lt.first; p != null; p = p.next)
2053	>	ln = new Node<V>(p.hash, p.key, p.val, ln);
2054	>	}
2055	>	else
2056	>	ln = new Node<V>(MOVED, lt, null, null);
2057	>	setTabAt(nextTab, i, ln);
2058	>	if (hc < TREE_THRESHOLD) {
2059	>	hn = null;
2060	>	for (Node<V> p = ht.first; p != null; p = p.next)
2061	>	hn = new Node<V>(p.hash, p.key, p.val, hn);
2062	>	}
2063	>	else
2064	>	hn = new Node<V>(MOVED, ht, null, null);
2065	>	setTabAt(nextTab, i + n, hn);
2066	>	setTabAt(tab, i, fwd);
2067	>	advance = true;
2068	>	}
2069	>	} finally {
2070	>	t.release(0);
2071	>	}
2072	>	}
2073	>	else
2074	>	advance = true; // already processed
2075	>	}
2076		}
2077
2078	<	/* ---------------- Public operations -------------- */
2078	>	/* ---------------- Counter support -------------- */
2079	>
2080	>	final long sumCount() {
2081	>	Cell[] as = counterCells; Cell a;
2082	>	long sum = baseCount;
2083	>	if (as != null) {
2084	>	for (int i = 0; i < as.length; ++i) {
2085	>	if ((a = as[i]) != null)
2086	>	sum += a.value;
2087	>	}
2088	>	}
2089	>	return sum;
2090	>	}
2091	>
2092	>	// See LongAdder version for explanation
2093	>	private final void fullAddCount(long x, boolean wasUncontended) {
2094	>	int h;
2095	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2096	>	ThreadLocalRandom.localInit();      // force initialization
2097	>	h = ThreadLocalRandom.getProbe();
2098	>	wasUncontended = true;
2099	>	}
2100	>	boolean collide = false;                // True if last slot nonempty
2101	>	for (;;) {
2102	>	Cell[] as; Cell a; int n; long v;
2103	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2104	>	if ((a = as[(n - 1) & h]) == null) {
2105	>	if (cellsBusy == 0) {            // Try to attach new Cell
2106	>	Cell r = new Cell(x); // Optimistic create
2107	>	if (cellsBusy == 0 &&
2108	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2109	>	boolean created = false;
2110	>	try {               // Recheck under lock
2111	>	Cell[] rs; int m, j;
2112	>	if ((rs = counterCells) != null &&
2113	>	(m = rs.length) > 0 &&
2114	>	rs[j = (m - 1) & h] == null) {
2115	>	rs[j] = r;
2116	>	created = true;
2117	>	}
2118	>	} finally {
2119	>	cellsBusy = 0;
2120	>	}
2121	>	if (created)
2122	>	break;
2123	>	continue;           // Slot is now non-empty
2124	>	}
2125	>	}
2126	>	collide = false;
2127	>	}
2128	>	else if (!wasUncontended)       // CAS already known to fail
2129	>	wasUncontended = true;      // Continue after rehash
2130	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2131	>	break;
2132	>	else if (counterCells != as || n >= NCPU)
2133	>	collide = false;            // At max size or stale
2134	>	else if (!collide)
2135	>	collide = true;
2136	>	else if (cellsBusy == 0 &&
2137	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2138	>	try {
2139	>	if (counterCells == as) {// Expand table unless stale
2140	>	Cell[] rs = new Cell[n << 1];
2141	>	for (int i = 0; i < n; ++i)
2142	>	rs[i] = as[i];
2143	>	counterCells = rs;
2144	>	}
2145	>	} finally {
2146	>	cellsBusy = 0;
2147	>	}
2148	>	collide = false;
2149	>	continue;                   // Retry with expanded table
2150	>	}
2151	>	h = ThreadLocalRandom.advanceProbe(h);
2152	>	}
2153	>	else if (cellsBusy == 0 && counterCells == as &&
2154	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2155	>	boolean init = false;
2156	>	try {                           // Initialize table
2157	>	if (counterCells == as) {
2158	>	Cell[] rs = new Cell[2];
2159	>	rs[h & 1] = new Cell(x);
2160	>	counterCells = rs;
2161	>	init = true;
2162	>	}
2163	>	} finally {
2164	>	cellsBusy = 0;
2165	>	}
2166	>	if (init)
2167	>	break;
2168	>	}
2169	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2170	>	break;                          // Fall back on using base
2171	>	}
2172	>	}
2173	>
2174	>	/* ----------------Table Traversal -------------- */
2175
2176		/**
2177	<	* Creates a new, empty map with the specified initial
2178	<	* capacity, load factor and concurrency level.
2177	>	* Encapsulates traversal for methods such as containsValue; also
2178	>	* serves as a base class for other iterators and bulk tasks.
2179		*
2180	<	* @param initialCapacity the initial capacity. The implementation
2181	<	* performs internal sizing to accommodate this many elements.
2182	<	* @param loadFactor  the load factor threshold, used to control resizing.
2183	<	* Resizing may be performed when the average number of elements per
2184	<	* bin exceeds this threshold.
2185	<	* @param concurrencyLevel the estimated number of concurrently
2186	<	* updating threads. The implementation performs internal sizing
2187	<	* to try to accommodate this many threads.
2188	<	* @throws IllegalArgumentException if the initial capacity is
2189	<	* negative or the load factor or concurrencyLevel are
2190	<	* nonpositive.
2180	>	* At each step, the iterator snapshots the key ("nextKey") and
2181	>	* value ("nextVal") of a valid node (i.e., one that, at point of
2182	>	* snapshot, has a non-null user value). Because val fields can
2183	>	* change (including to null, indicating deletion), field nextVal
2184	>	* might not be accurate at point of use, but still maintains the
2185	>	* weak consistency property of holding a value that was once
2186	>	* valid. To support iterator.remove, the nextKey field is not
2187	>	* updated (nulled out) when the iterator cannot advance.
2188	>	*
2189	>	* Exported iterators must track whether the iterator has advanced
2190	>	* (in hasNext vs next) (by setting/checking/nulling field
2191	>	* nextVal), and then extract key, value, or key-value pairs as
2192	>	* return values of next().
2193	>	*
2194	>	* Method advance visits once each still-valid node that was
2195	>	* reachable upon iterator construction. It might miss some that
2196	>	* were added to a bin after the bin was visited, which is OK wrt
2197	>	* consistency guarantees. Maintaining this property in the face
2198	>	* of possible ongoing resizes requires a fair amount of
2199	>	* bookkeeping state that is difficult to optimize away amidst
2200	>	* volatile accesses.  Even so, traversal maintains reasonable
2201	>	* throughput.
2202	>	*
2203	>	* Normally, iteration proceeds bin-by-bin traversing lists.
2204	>	* However, if the table has been resized, then all future steps
2205	>	* must traverse both the bin at the current index as well as at
2206	>	* (index + baseSize); and so on for further resizings. To
2207	>	* paranoically cope with potential sharing by users of iterators
2208	>	* across threads, iteration terminates if a bounds checks fails
2209	>	* for a table read.
2210	>	*
2211	>	* Methods advanceKey and advanceValue are specializations of the
2212	>	* common cases of advance, relaying to the full version
2213	>	* otherwise. The forEachKey and forEachValue methods further
2214	>	* specialize, bypassing all incremental field updates in most cases.
2215	>	*
2216	>	* This class supports both Spliterator-based traversal and
2217	>	* CountedCompleter-based bulk tasks. The same "batch" field is
2218	>	* used, but in slightly different ways, in the two cases.  For
2219	>	* Spliterators, it is a saturating (at Integer.MAX_VALUE)
2220	>	* estimate of element coverage. For CHM tasks, it is a pre-scaled
2221	>	* size that halves down to zero for leaf tasks, that is only
2222	>	* computed upon execution of the task. (Tasks can be submitted to
2223	>	* any pool, of any size, so we don't know scale factors until
2224	>	* running.)
2225	>	*
2226	>	* This class extends CountedCompleter to streamline parallel
2227	>	* iteration in bulk operations. This adds only a few fields of
2228	>	* space overhead, which is small enough in cases where it is not
2229	>	* needed to not worry about it.  Because CountedCompleter is
2230	>	* Serializable, but iterators need not be, we need to add warning
2231	>	* suppressions.
2232	>	*/
2233	>	@SuppressWarnings("serial") static class Traverser<K,V,R>
2234	>	extends CountedCompleter<R> {
2235	>	final ConcurrentHashMap<K,V> map;
2236	>	Node<V> next;        // the next entry to use
2237	>	K nextKey;           // cached key field of next
2238	>	V nextVal;           // cached val field of next
2239	>	Node<V>[] tab;       // current table; updated if resized
2240	>	int index;           // index of bin to use next
2241	>	int baseIndex;       // current index of initial table
2242	>	int baseLimit;       // index bound for initial table
2243	>	final int baseSize;  // initial table size
2244	>	int batch;           // split control
2245	>
2246	>	/** Creates iterator for all entries in the table. */
2247	>	Traverser(ConcurrentHashMap<K,V> map) {
2248	>	this.map = map;
2249	>	Node<V>[] t = this.tab = map.table;
2250	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2251	>	}
2252	>
2253	>	/** Task constructor */
2254	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it, int batch) {
2255	>	super(it);
2256	>	this.map = map;
2257	>	this.batch = batch; // -1 if unknown
2258	>	if (it == null) {
2259	>	Node<V>[] t = this.tab = map.table;
2260	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2261	>	}
2262	>	else { // split parent
2263	>	this.tab = it.tab;
2264	>	this.baseSize = it.baseSize;
2265	>	int hi = this.baseLimit = it.baseLimit;
2266	>	it.baseLimit = this.index = this.baseIndex =
2267	>	(hi + it.baseIndex) >>> 1;
2268	>	}
2269	>	}
2270	>
2271	>	/** Spliterator constructor */
2272	>	Traverser(ConcurrentHashMap<K,V> map, Traverser<K,V,?> it) {
2273	>	super(it);
2274	>	this.map = map;
2275	>	if (it == null) {
2276	>	Node<V>[] t = this.tab = map.table;
2277	>	baseLimit = baseSize = (t == null) ? 0 : t.length;
2278	>	long n = map.sumCount();
2279	>	batch = ((n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2280	>	(int)n);
2281	>	}
2282	>	else {
2283	>	this.tab = it.tab;
2284	>	this.baseSize = it.baseSize;
2285	>	int hi = this.baseLimit = it.baseLimit;
2286	>	it.baseLimit = this.index = this.baseIndex =
2287	>	(hi + it.baseIndex) >>> 1;
2288	>	this.batch = it.batch >>>= 1;
2289	>	}
2290	>	}
2291	>
2292	>	/**
2293	>	* Advances if possible, returning next valid value, or null if none.
2294	>	*/
2295	>	@SuppressWarnings("unchecked") final V advance() {
2296	>	for (Node<V> e = next;;) {
2297	>	if (e != null)                  // advance past used/skipped node
2298	>	e = next = e.next;
2299	>	while (e == null) {             // get to next non-null bin
2300	>	Node<V>[] t; int i, n;      // must use locals in checks
2301	>	if (baseIndex >= baseLimit || (t = tab) == null ||
2302	>	(n = t.length) <= (i = index) || i < 0)
2303	>	return nextVal = null;
2304	>	if ((e = next = tabAt(t, index)) != null && e.hash < 0) {
2305	>	Object ek;
2306	>	if ((ek = e.key) instanceof TreeBin)
2307	>	e = ((TreeBin<V>)ek).first;
2308	>	else {
2309	>	tab = (Node<V>[])ek;
2310	>	continue;           // restarts due to null val
2311	>	}
2312	>	}
2313	>	if ((index += baseSize) >= n)
2314	>	index = ++baseIndex;    // visit upper slots if present
2315	>	}
2316	>	nextKey = (K)e.key;
2317	>	if ((nextVal = e.val) != null) // skip deleted or special nodes
2318	>	return nextVal;
2319	>	}
2320	>	}
2321	>
2322	>	/**
2323	>	* Common case version for value traversal
2324	>	*/
2325	>	@SuppressWarnings("unchecked") final V advanceValue() {
2326	>	outer: for (Node<V> e = next;;) {
2327	>	if (e == null || (e = e.next) == null) {
2328	>	Node<V>[] t; int i, len, n; Object ek;
2329	>	if ((t = tab) == null ||
2330	>	baseSize != (len = t.length) ||
2331	>	len < (n = baseLimit) ||
2332	>	baseIndex != (i = index))
2333	>	break;
2334	>	do {
2335	>	if (i < 0 || i >= n) {
2336	>	index = baseIndex = n;
2337	>	next = null;
2338	>	return nextVal = null;
2339	>	}
2340	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2341	>	if ((ek = e.key) instanceof TreeBin)
2342	>	e = ((TreeBin<V>)ek).first;
2343	>	else {
2344	>	index = baseIndex = i;
2345	>	next = null;
2346	>	tab = (Node<V>[])ek;
2347	>	break outer;
2348	>	}
2349	>	}
2350	>	++i;
2351	>	} while (e == null);
2352	>	index = baseIndex = i;
2353	>	}
2354	>	V v;
2355	>	K k = (K)e.key;
2356	>	if ((v = e.val) != null) {
2357	>	nextVal = v;
2358	>	nextKey = k;
2359	>	next = e;
2360	>	return v;
2361	>	}
2362	>	}
2363	>	return advance();
2364	>	}
2365	>
2366	>	/**
2367	>	* Common case version for key traversal
2368	>	*/
2369	>	@SuppressWarnings("unchecked") final K advanceKey() {
2370	>	outer: for (Node<V> e = next;;) {
2371	>	if (e == null || (e = e.next) == null) {
2372	>	Node<V>[] t; int i, len, n; Object ek;
2373	>	if ((t = tab) == null ||
2374	>	baseSize != (len = t.length) ||
2375	>	len < (n = baseLimit) ||
2376	>	baseIndex != (i = index))
2377	>	break;
2378	>	do {
2379	>	if (i < 0 || i >= n) {
2380	>	index = baseIndex = n;
2381	>	next = null;
2382	>	nextVal = null;
2383	>	return null;
2384	>	}
2385	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2386	>	if ((ek = e.key) instanceof TreeBin)
2387	>	e = ((TreeBin<V>)ek).first;
2388	>	else {
2389	>	index = baseIndex = i;
2390	>	next = null;
2391	>	tab = (Node<V>[])ek;
2392	>	break outer;
2393	>	}
2394	>	}
2395	>	++i;
2396	>	} while (e == null);
2397	>	index = baseIndex = i;
2398	>	}
2399	>	V v;
2400	>	K k = (K)e.key;
2401	>	if ((v = e.val) != null) {
2402	>	nextVal = v;
2403	>	nextKey = k;
2404	>	next = e;
2405	>	return k;
2406	>	}
2407	>	}
2408	>	return (advance() == null) ? null : nextKey;
2409	>	}
2410	>
2411	>	@SuppressWarnings("unchecked") final void forEachValue(Consumer<? super V> action) {
2412	>	if (action == null) throw new NullPointerException();
2413	>	Node<V>[] t; int i, len, n;
2414	>	if ((t = tab) != null && baseSize == (len = t.length) &&
2415	>	len >= (n = baseLimit) && baseIndex == (i = index)) {
2416	>	index = baseIndex = n;
2417	>	nextVal = null;
2418	>	Node<V> e = next;
2419	>	next = null;
2420	>	if (e != null)
2421	>	e = e.next;
2422	>	outer: for (;; e = e.next) {
2423	>	V v; Object ek;
2424	>	for (; e == null; ++i) {
2425	>	if (i < 0 || i >= n)
2426	>	return;
2427	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2428	>	if ((ek = e.key) instanceof TreeBin)
2429	>	e = ((TreeBin<V>)ek).first;
2430	>	else {
2431	>	index = baseIndex = i;
2432	>	tab = (Node<V>[])ek;
2433	>	break outer;
2434	>	}
2435	>	}
2436	>	}
2437	>	if ((v = e.val) != null)
2438	>	action.accept(v);
2439	>	}
2440	>	}
2441	>	V v;
2442	>	while ((v = advance()) != null)
2443	>	action.accept(v);
2444	>	}
2445	>
2446	>	@SuppressWarnings("unchecked") final void forEachKey(Consumer<? super K> action) {
2447	>	if (action == null) throw new NullPointerException();
2448	>	Node<V>[] t; int i, len, n;
2449	>	if ((t = tab) != null && baseSize == (len = t.length) &&
2450	>	len >= (n = baseLimit) && baseIndex == (i = index)) {
2451	>	index = baseIndex = n;
2452	>	nextVal = null;
2453	>	Node<V> e = next;
2454	>	next = null;
2455	>	if (e != null)
2456	>	e = e.next;
2457	>	outer: for (;; e = e.next) {
2458	>	for (; e == null; ++i) {
2459	>	if (i < 0 || i >= n)
2460	>	return;
2461	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
2462	>	Object ek;
2463	>	if ((ek = e.key) instanceof TreeBin)
2464	>	e = ((TreeBin<V>)ek).first;
2465	>	else {
2466	>	index = baseIndex = i;
2467	>	tab = (Node<V>[])ek;
2468	>	break outer;
2469	>	}
2470	>	}
2471	>	}
2472	>	Object k = e.key;
2473	>	if (e.val != null)
2474	>	action.accept((K)k);
2475	>	}
2476	>	}
2477	>	while (advance() != null)
2478	>	action.accept(nextKey);
2479	>	}
2480	>
2481	>	public final void remove() {
2482	>	K k = nextKey;
2483	>	if (k == null && (advanceValue() == null || (k = nextKey) == null))
2484	>	throw new IllegalStateException();
2485	>	map.internalReplace(k, null, null);
2486	>	}
2487	>
2488	>	public final boolean hasNext() {
2489	>	return nextVal != null || advanceValue() != null;
2490	>	}
2491	>
2492	>	public final boolean hasMoreElements() { return hasNext(); }
2493	>
2494	>	public void compute() { } // default no-op CountedCompleter body
2495	>
2496	>	public long estimateSize() { return batch; }
2497	>
2498	>	/**
2499	>	* Returns a batch value > 0 if this task should (and must) be
2500	>	* split, if so, adding to pending count, and in any case
2501	>	* updating batch value. The initial batch value is approx
2502	>	* exp2 of the number of times (minus one) to split task by
2503	>	* two before executing leaf action. This value is faster to
2504	>	* compute and more convenient to use as a guide to splitting
2505	>	* than is the depth, since it is used while dividing by two
2506	>	* anyway.
2507	>	*/
2508	>	final int preSplit() {
2509	>	int b;  ForkJoinPool pool;
2510	>	if ((b = batch) < 0) { // force initialization
2511	>	int sp = (((pool = getPool()) == null) ?
2512	>	ForkJoinPool.getCommonPoolParallelism() :
2513	>	pool.getParallelism()) << 3; // slack of 8
2514	>	long n = map.sumCount();
2515	>	b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp;
2516	>	}
2517	>	b = (b <= 1 || baseIndex >= baseLimit) ? 0 : (b >>> 1);
2518	>	if ((batch = b) > 0)
2519	>	addToPendingCount(1);
2520	>	return b;
2521	>	}
2522	>	}
2523	>
2524	>	/* ---------------- Public operations -------------- */
2525	>
2526	>	/**
2527	>	* Creates a new, empty map with the default initial table size (16).
2528		*/
2529	<	@SuppressWarnings("unchecked")
703	<	public ConcurrentHashMap(int initialCapacity,
704	<	float loadFactor, int concurrencyLevel) {
705	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
706	<	throw new IllegalArgumentException();
707	<	if (concurrencyLevel > MAX_SEGMENTS)
708	<	concurrencyLevel = MAX_SEGMENTS;
709	<	// Find power-of-two sizes best matching arguments
710	<	int sshift = 0;
711	<	int ssize = 1;
712	<	while (ssize < concurrencyLevel) {
713	<	++sshift;
714	<	ssize <<= 1;
715	<	}
716	<	this.segmentShift = 32 - sshift;
717	<	this.segmentMask = ssize - 1;
718	<	if (initialCapacity > MAXIMUM_CAPACITY)
719	<	initialCapacity = MAXIMUM_CAPACITY;
720	<	int c = initialCapacity / ssize;
721	<	if (c * ssize < initialCapacity)
722	<	++c;
723	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
724	<	while (cap < c)
725	<	cap <<= 1;
726	<	// create segments and segments[0]
727	<	Segment<K,V> s0 =
728	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
729	<	(HashEntry<K,V>[])new HashEntry<?,?>[cap]);
730	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment<?,?>[ssize];
731	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
732	<	this.segments = ss;
2529	>	public ConcurrentHashMap() {
2530		}
2531
2532		/**
2533	<	* Creates a new, empty map with the specified initial capacity
2534	<	* and load factor and with the default concurrencyLevel (16).
2533	>	* Creates a new, empty map with an initial table size
2534	>	* accommodating the specified number of elements without the need
2535	>	* to dynamically resize.
2536		*
2537		* @param initialCapacity The implementation performs internal
2538		* sizing to accommodate this many elements.
2539	<	* @param loadFactor  the load factor threshold, used to control resizing.
2540	<	* Resizing may be performed when the average number of elements per
2541	<	* bin exceeds this threshold.
2539	>	* @throws IllegalArgumentException if the initial capacity of
2540	>	* elements is negative
2541	>	*/
2542	>	public ConcurrentHashMap(int initialCapacity) {
2543	>	if (initialCapacity < 0)
2544	>	throw new IllegalArgumentException();
2545	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
2546	>	MAXIMUM_CAPACITY :
2547	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
2548	>	this.sizeCtl = cap;
2549	>	}
2550	>
2551	>	/**
2552	>	* Creates a new map with the same mappings as the given map.
2553	>	*
2554	>	* @param m the map
2555	>	*/
2556	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2557	>	this.sizeCtl = DEFAULT_CAPACITY;
2558	>	internalPutAll(m);
2559	>	}
2560	>
2561	>	/**
2562	>	* Creates a new, empty map with an initial table size based on
2563	>	* the given number of elements ({@code initialCapacity}) and
2564	>	* initial table density ({@code loadFactor}).
2565	>	*
2566	>	* @param initialCapacity the initial capacity. The implementation
2567	>	* performs internal sizing to accommodate this many elements,
2568	>	* given the specified load factor.
2569	>	* @param loadFactor the load factor (table density) for
2570	>	* establishing the initial table size
2571		* @throws IllegalArgumentException if the initial capacity of
2572		* elements is negative or the load factor is nonpositive
2573		*
2574		* @since 1.6
2575		*/
2576		public ConcurrentHashMap(int initialCapacity, float loadFactor) {
2577	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
2577	>	this(initialCapacity, loadFactor, 1);
2578		}
2579
2580		/**
2581	<	* Creates a new, empty map with the specified initial capacity,
2582	<	* and with default load factor (0.75) and concurrencyLevel (16).
2581	>	* Creates a new, empty map with an initial table size based on
2582	>	* the given number of elements ({@code initialCapacity}), table
2583	>	* density ({@code loadFactor}), and number of concurrently
2584	>	* updating threads ({@code concurrencyLevel}).
2585		*
2586		* @param initialCapacity the initial capacity. The implementation
2587	<	* performs internal sizing to accommodate this many elements.
2588	<	* @throws IllegalArgumentException if the initial capacity of
2589	<	* elements is negative.
2587	>	* performs internal sizing to accommodate this many elements,
2588	>	* given the specified load factor.
2589	>	* @param loadFactor the load factor (table density) for
2590	>	* establishing the initial table size
2591	>	* @param concurrencyLevel the estimated number of concurrently
2592	>	* updating threads. The implementation may use this value as
2593	>	* a sizing hint.
2594	>	* @throws IllegalArgumentException if the initial capacity is
2595	>	* negative or the load factor or concurrencyLevel are
2596	>	* nonpositive
2597		*/
2598	<	public ConcurrentHashMap(int initialCapacity) {
2599	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2598	>	public ConcurrentHashMap(int initialCapacity,
2599	>	float loadFactor, int concurrencyLevel) {
2600	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
2601	>	throw new IllegalArgumentException();
2602	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
2603	>	initialCapacity = concurrencyLevel;   // as estimated threads
2604	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
2605	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
2606	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
2607	>	this.sizeCtl = cap;
2608		}
2609
2610		/**
2611	<	* Creates a new, empty map with a default initial capacity (16),
2612	<	* load factor (0.75) and concurrencyLevel (16).
2611	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2612	>	* from the given type to {@code Boolean.TRUE}.
2613	>	*
2614	>	* @return the new set
2615		*/
2616	<	public ConcurrentHashMap() {
2617	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
2616	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2617	>	return new KeySetView<K,Boolean>
2618	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2619		}
2620
2621		/**
2622	<	* Creates a new map with the same mappings as the given map.
2623	<	* The map is created with a capacity of 1.5 times the number
777	<	* of mappings in the given map or 16 (whichever is greater),
778	<	* and a default load factor (0.75) and concurrencyLevel (16).
2622	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2623	>	* from the given type to {@code Boolean.TRUE}.
2624		*
2625	<	* @param m the map
2625	>	* @param initialCapacity The implementation performs internal
2626	>	* sizing to accommodate this many elements.
2627	>	* @throws IllegalArgumentException if the initial capacity of
2628	>	* elements is negative
2629	>	* @return the new set
2630		*/
2631	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
2632	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
2633	<	DEFAULT_INITIAL_CAPACITY),
785	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
786	<	putAll(m);
2631	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2632	>	return new KeySetView<K,Boolean>
2633	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2634		}
2635
2636		/**
2637	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
791	<	*
792	<	* @return <tt>true</tt> if this map contains no key-value mappings
2637	>	* {@inheritDoc}
2638		*/
2639		public boolean isEmpty() {
2640	<	/*
796	<	* Sum per-segment modCounts to avoid mis-reporting when
797	<	* elements are concurrently added and removed in one segment
798	<	* while checking another, in which case the table was never
799	<	* actually empty at any point. (The sum ensures accuracy up
800	<	* through at least 1<<31 per-segment modifications before
801	<	* recheck.)  Methods size() and containsValue() use similar
802	<	* constructions for stability checks.
803	<	*/
804	<	long sum = 0L;
805	<	final Segment<K,V>[] segments = this.segments;
806	<	for (int j = 0; j < segments.length; ++j) {
807	<	Segment<K,V> seg = segmentAt(segments, j);
808	<	if (seg != null) {
809	<	if (seg.count != 0)
810	<	return false;
811	<	sum += seg.modCount;
812	<	}
813	<	}
814	<	if (sum != 0L) { // recheck unless no modifications
815	<	for (int j = 0; j < segments.length; ++j) {
816	<	Segment<K,V> seg = segmentAt(segments, j);
817	<	if (seg != null) {
818	<	if (seg.count != 0)
819	<	return false;
820	<	sum -= seg.modCount;
821	<	}
822	<	}
823	<	if (sum != 0L)
824	<	return false;
825	<	}
826	<	return true;
2640	>	return sumCount() <= 0L; // ignore transient negative values
2641		}
2642
2643		/**
2644	<	* Returns the number of key-value mappings in this map.  If the
831	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
832	<	* <tt>Integer.MAX_VALUE</tt>.
833	<	*
834	<	* @return the number of key-value mappings in this map
2644	>	* {@inheritDoc}
2645		*/
2646		public int size() {
2647	<	// Try a few times to get accurate count. On failure due to
2648	<	// continuous async changes in table, resort to locking.
2649	<	final Segment<K,V>[] segments = this.segments;
2650	<	final int segmentCount = segments.length;
2651	<
842	<	long previousSum = 0L;
843	<	for (int retries = -1; retries < RETRIES_BEFORE_LOCK; retries++) {
844	<	long sum = 0L;    // sum of modCounts
845	<	long size = 0L;
846	<	for (int i = 0; i < segmentCount; i++) {
847	<	Segment<K,V> segment = segmentAt(segments, i);
848	<	if (segment != null) {
849	<	sum += segment.modCount;
850	<	size += segment.count;
851	<	}
852	<	}
853	<	if (sum == previousSum)
854	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
855	<	previousSum = sum;
856	<	}
2647	>	long n = sumCount();
2648	>	return ((n < 0L) ? 0 :
2649	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
2650	>	(int)n);
2651	>	}
2652
2653	<	long size = 0L;
2654	<	for (int i = 0; i < segmentCount; i++) {
2655	<	Segment<K,V> segment = ensureSegment(i);
2656	<	segment.lock();
2657	<	size += segment.count;
2658	<	}
2659	<	for (int i = 0; i < segmentCount; i++)
2660	<	segments[i].unlock();
2661	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
2653	>	/**
2654	>	* Returns the number of mappings. This method should be used
2655	>	* instead of {@link #size} because a ConcurrentHashMap may
2656	>	* contain more mappings than can be represented as an int. The
2657	>	* value returned is an estimate; the actual count may differ if
2658	>	* there are concurrent insertions or removals.
2659	>	*
2660	>	* @return the number of mappings
2661	>	*/
2662	>	public long mappingCount() {
2663	>	long n = sumCount();
2664	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2665		}
2666
2667		/**
#	Line 877 | Line 2675 | public class ConcurrentHashMap<K, V> ext
2675		*
2676		* @throws NullPointerException if the specified key is null
2677		*/
880	–	@SuppressWarnings("unchecked")
2678		public V get(Object key) {
2679	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
2680	<	HashEntry<K,V>[] tab;
2681	<	int h = hash(key.hashCode());
2682	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
2683	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
2684	<	(tab = s.table) != null) {
2685	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
2686	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
2687	<	e != null; e = e.next) {
2688	<	K k;
2689	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
2690	<	return e.value;
2691	<	}
2692	<	}
2693	<	return null;
2679	>	return internalGet(key);
2680	>	}
2681	>
2682	>	/**
2683	>	* Returns the value to which the specified key is mapped,
2684	>	* or the given defaultValue if this map contains no mapping for the key.
2685	>	*
2686	>	* @param key the key
2687	>	* @param defaultValue the value to return if this map contains
2688	>	* no mapping for the given key
2689	>	* @return the mapping for the key, if present; else the defaultValue
2690	>	* @throws NullPointerException if the specified key is null
2691	>	*/
2692	>	public V getOrDefault(Object key, V defaultValue) {
2693	>	V v;
2694	>	return (v = internalGet(key)) == null ? defaultValue : v;
2695		}
2696
2697		/**
2698		* Tests if the specified object is a key in this table.
2699		*
2700	<	* @param  key   possible key
2701	<	* @return <tt>true</tt> if and only if the specified object
2700	>	* @param  key possible key
2701	>	* @return {@code true} if and only if the specified object
2702		*         is a key in this table, as determined by the
2703	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
2703	>	*         {@code equals} method; {@code false} otherwise
2704		* @throws NullPointerException if the specified key is null
2705		*/
908	–	@SuppressWarnings("unchecked")
2706		public boolean containsKey(Object key) {
2707	<	Segment<K,V> s; // same as get() except no need for volatile value read
911	<	HashEntry<K,V>[] tab;
912	<	int h = hash(key.hashCode());
913	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
914	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
915	<	(tab = s.table) != null) {
916	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
917	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
918	<	e != null; e = e.next) {
919	<	K k;
920	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
921	<	return true;
922	<	}
923	<	}
924	<	return false;
2707	>	return internalGet(key) != null;
2708		}
2709
2710		/**
2711	<	* Returns <tt>true</tt> if this map maps one or more keys to the
2712	<	* specified value. Note: This method requires a full internal
2713	<	* traversal of the hash table, and so is much slower than
931	<	* method <tt>containsKey</tt>.
2711	>	* Returns {@code true} if this map maps one or more keys to the
2712	>	* specified value. Note: This method may require a full traversal
2713	>	* of the map, and is much slower than method {@code containsKey}.
2714		*
2715		* @param value value whose presence in this map is to be tested
2716	<	* @return <tt>true</tt> if this map maps one or more keys to the
2716	>	* @return {@code true} if this map maps one or more keys to the
2717		*         specified value
2718		* @throws NullPointerException if the specified value is null
2719		*/
2720		public boolean containsValue(Object value) {
939	–	// Same idea as size()
2721		if (value == null)
2722		throw new NullPointerException();
2723	<	final Segment<K,V>[] segments = this.segments;
2724	<	long previousSum = 0L;
2725	<	int lockCount = 0;
2726	<	try {
2727	<	for (int retries = -1; ; retries++) {
947	<	long sum = 0L;    // sum of modCounts
948	<	for (int j = 0; j < segments.length; j++) {
949	<	Segment<K,V> segment;
950	<	if (retries == RETRIES_BEFORE_LOCK) {
951	<	segment = ensureSegment(j);
952	<	segment.lock();
953	<	lockCount++;
954	<	} else {
955	<	segment = segmentAt(segments, j);
956	<	if (segment == null)
957	<	continue;
958	<	}
959	<	HashEntry<K,V>[] tab = segment.table;
960	<	if (tab != null) {
961	<	for (int i = 0 ; i < tab.length; i++) {
962	<	HashEntry<K,V> e;
963	<	for (e = entryAt(tab, i); e != null; e = e.next) {
964	<	V v = e.value;
965	<	if (v != null && value.equals(v))
966	<	return true;
967	<	}
968	<	}
969	<	sum += segment.modCount;
970	<	}
971	<	}
972	<	if ((retries >= 0 && sum == previousSum) || lockCount > 0)
973	<	return false;
974	<	previousSum = sum;
975	<	}
976	<	} finally {
977	<	for (int j = 0; j < lockCount; j++)
978	<	segments[j].unlock();
2723	>	V v;
2724	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
2725	>	while ((v = it.advanceValue()) != null) {
2726	>	if (v == value || value.equals(v))
2727	>	return true;
2728		}
2729	+	return false;
2730		}
2731
2732		/**
2733		* Legacy method testing if some key maps into the specified value
2734		* in this table.  This method is identical in functionality to
2735	<	* {@link #containsValue}, and exists solely to ensure
2735	>	* {@link #containsValue(Object)}, and exists solely to ensure
2736		* full compatibility with class {@link java.util.Hashtable},
2737		* which supported this method prior to introduction of the
2738		* Java Collections framework.
2739		*
2740		* @param  value a value to search for
2741	<	* @return <tt>true</tt> if and only if some key maps to the
2742	<	*         <tt>value</tt> argument in this table as
2743	<	*         determined by the <tt>equals</tt> method;
2744	<	*         <tt>false</tt> otherwise
2741	>	* @return {@code true} if and only if some key maps to the
2742	>	*         {@code value} argument in this table as
2743	>	*         determined by the {@code equals} method;
2744	>	*         {@code false} otherwise
2745		* @throws NullPointerException if the specified value is null
2746		*/
2747	<	public boolean contains(Object value) {
2747	>	@Deprecated public boolean contains(Object value) {
2748		return containsValue(value);
2749		}
2750
#	Line 1002 | Line 2752 | public class ConcurrentHashMap<K, V> ext
2752		* Maps the specified key to the specified value in this table.
2753		* Neither the key nor the value can be null.
2754		*
2755	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
2755	>	* <p>The value can be retrieved by calling the {@code get} method
2756		* with a key that is equal to the original key.
2757		*
2758		* @param key key with which the specified value is to be associated
2759		* @param value value to be associated with the specified key
2760	<	* @return the previous value associated with <tt>key</tt>, or
2761	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2760	>	* @return the previous value associated with {@code key}, or
2761	>	*         {@code null} if there was no mapping for {@code key}
2762		* @throws NullPointerException if the specified key or value is null
2763		*/
1014	–	@SuppressWarnings("unchecked")
2764		public V put(K key, V value) {
2765	<	Segment<K,V> s;
1017	<	if (value == null)
1018	<	throw new NullPointerException();
1019	<	int hash = hash(key.hashCode());
1020	<	int j = (hash >>> segmentShift) & segmentMask;
1021	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1022	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1023	<	s = ensureSegment(j);
1024	<	return s.put(key, hash, value, false);
2765	>	return internalPut(key, value, false);
2766		}
2767
2768		/**
2769		* {@inheritDoc}
2770		*
2771		* @return the previous value associated with the specified key,
2772	<	*         or <tt>null</tt> if there was no mapping for the key
2772	>	*         or {@code null} if there was no mapping for the key
2773		* @throws NullPointerException if the specified key or value is null
2774		*/
1034	–	@SuppressWarnings("unchecked")
2775		public V putIfAbsent(K key, V value) {
2776	<	Segment<K,V> s;
1037	<	if (value == null)
1038	<	throw new NullPointerException();
1039	<	int hash = hash(key.hashCode());
1040	<	int j = (hash >>> segmentShift) & segmentMask;
1041	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1042	<	(segments, (j << SSHIFT) + SBASE)) == null)
1043	<	s = ensureSegment(j);
1044	<	return s.put(key, hash, value, true);
2776	>	return internalPut(key, value, true);
2777		}
2778
2779		/**
#	Line 1052 | Line 2784 | public class ConcurrentHashMap<K, V> ext
2784		* @param m mappings to be stored in this map
2785		*/
2786		public void putAll(Map<? extends K, ? extends V> m) {
2787	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2788	<	put(e.getKey(), e.getValue());
2787	>	internalPutAll(m);
2788	>	}
2789	>
2790	>	/**
2791	>	* If the specified key is not already associated with a value (or
2792	>	* is mapped to {@code null}), attempts to compute its value using
2793	>	* the given mapping function and enters it into this map unless
2794	>	* {@code null}. The entire method invocation is performed
2795	>	* atomically, so the function is applied at most once per key.
2796	>	* Some attempted update operations on this map by other threads
2797	>	* may be blocked while computation is in progress, so the
2798	>	* computation should be short and simple, and must not attempt to
2799	>	* update any other mappings of this Map.
2800	>	*
2801	>	* @param key key with which the specified value is to be associated
2802	>	* @param mappingFunction the function to compute a value
2803	>	* @return the current (existing or computed) value associated with
2804	>	*         the specified key, or null if the computed value is null
2805	>	* @throws NullPointerException if the specified key or mappingFunction
2806	>	*         is null
2807	>	* @throws IllegalStateException if the computation detectably
2808	>	*         attempts a recursive update to this map that would
2809	>	*         otherwise never complete
2810	>	* @throws RuntimeException or Error if the mappingFunction does so,
2811	>	*         in which case the mapping is left unestablished
2812	>	*/
2813	>	public V computeIfAbsent
2814	>	(K key, Function<? super K, ? extends V> mappingFunction) {
2815	>	return internalComputeIfAbsent(key, mappingFunction);
2816	>	}
2817	>
2818	>	/**
2819	>	* If the value for the specified key is present and non-null,
2820	>	* attempts to compute a new mapping given the key and its current
2821	>	* mapped value.  The entire method invocation is performed
2822	>	* atomically.  Some attempted update operations on this map by
2823	>	* other threads may be blocked while computation is in progress,
2824	>	* so the computation should be short and simple, and must not
2825	>	* attempt to update any other mappings of this Map.
2826	>	*
2827	>	* @param key key with which a value may be associated
2828	>	* @param remappingFunction the function to compute a value
2829	>	* @return the new value associated with the specified key, or null if none
2830	>	* @throws NullPointerException if the specified key or remappingFunction
2831	>	*         is null
2832	>	* @throws IllegalStateException if the computation detectably
2833	>	*         attempts a recursive update to this map that would
2834	>	*         otherwise never complete
2835	>	* @throws RuntimeException or Error if the remappingFunction does so,
2836	>	*         in which case the mapping is unchanged
2837	>	*/
2838	>	public V computeIfPresent
2839	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2840	>	return internalCompute(key, true, remappingFunction);
2841	>	}
2842	>
2843	>	/**
2844	>	* Attempts to compute a mapping for the specified key and its
2845	>	* current mapped value (or {@code null} if there is no current
2846	>	* mapping). The entire method invocation is performed atomically.
2847	>	* Some attempted update operations on this map by other threads
2848	>	* may be blocked while computation is in progress, so the
2849	>	* computation should be short and simple, and must not attempt to
2850	>	* update any other mappings of this Map.
2851	>	*
2852	>	* @param key key with which the specified value is to be associated
2853	>	* @param remappingFunction the function to compute a value
2854	>	* @return the new value associated with the specified key, or null if none
2855	>	* @throws NullPointerException if the specified key or remappingFunction
2856	>	*         is null
2857	>	* @throws IllegalStateException if the computation detectably
2858	>	*         attempts a recursive update to this map that would
2859	>	*         otherwise never complete
2860	>	* @throws RuntimeException or Error if the remappingFunction does so,
2861	>	*         in which case the mapping is unchanged
2862	>	*/
2863	>	public V compute
2864	>	(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
2865	>	return internalCompute(key, false, remappingFunction);
2866	>	}
2867	>
2868	>	/**
2869	>	* If the specified key is not already associated with a
2870	>	* (non-null) value, associates it with the given value.
2871	>	* Otherwise, replaces the value with the results of the given
2872	>	* remapping function, or removes if {@code null}. The entire
2873	>	* method invocation is performed atomically.  Some attempted
2874	>	* update operations on this map by other threads may be blocked
2875	>	* while computation is in progress, so the computation should be
2876	>	* short and simple, and must not attempt to update any other
2877	>	* mappings of this Map.
2878	>	*
2879	>	* @param key key with which the specified value is to be associated
2880	>	* @param value the value to use if absent
2881	>	* @param remappingFunction the function to recompute a value if present
2882	>	* @return the new value associated with the specified key, or null if none
2883	>	* @throws NullPointerException if the specified key or the
2884	>	*         remappingFunction is null
2885	>	* @throws RuntimeException or Error if the remappingFunction does so,
2886	>	*         in which case the mapping is unchanged
2887	>	*/
2888	>	public V merge
2889	>	(K key, V value,
2890	>	BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2891	>	return internalMerge(key, value, remappingFunction);
2892		}
2893
2894		/**
#	Line 1061 | Line 2896 | public class ConcurrentHashMap<K, V> ext
2896		* This method does nothing if the key is not in the map.
2897		*
2898		* @param  key the key that needs to be removed
2899	<	* @return the previous value associated with <tt>key</tt>, or
2900	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
2899	>	* @return the previous value associated with {@code key}, or
2900	>	*         {@code null} if there was no mapping for {@code key}
2901		* @throws NullPointerException if the specified key is null
2902		*/
2903		public V remove(Object key) {
2904	<	int hash = hash(key.hashCode());
1070	<	Segment<K,V> s = segmentForHash(hash);
1071	<	return s == null ? null : s.remove(key, hash, null);
2904	>	return internalReplace(key, null, null);
2905		}
2906
2907		/**
#	Line 1077 | Line 2910 | public class ConcurrentHashMap<K, V> ext
2910		* @throws NullPointerException if the specified key is null
2911		*/
2912		public boolean remove(Object key, Object value) {
2913	<	int hash = hash(key.hashCode());
2914	<	Segment<K,V> s;
2915	<	return value != null && (s = segmentForHash(hash)) != null &&
1083	<	s.remove(key, hash, value) != null;
2913	>	if (key == null)
2914	>	throw new NullPointerException();
2915	>	return value != null && internalReplace(key, null, value) != null;
2916		}
2917
2918		/**
#	Line 1089 | Line 2921 | public class ConcurrentHashMap<K, V> ext
2921		* @throws NullPointerException if any of the arguments are null
2922		*/
2923		public boolean replace(K key, V oldValue, V newValue) {
2924	<	int hash = hash(key.hashCode());
1093	<	if (oldValue == null || newValue == null)
2924	>	if (key == null || oldValue == null || newValue == null)
2925		throw new NullPointerException();
2926	<	Segment<K,V> s = segmentForHash(hash);
1096	<	return s != null && s.replace(key, hash, oldValue, newValue);
2926	>	return internalReplace(key, newValue, oldValue) != null;
2927		}
2928
2929		/**
2930		* {@inheritDoc}
2931		*
2932		* @return the previous value associated with the specified key,
2933	<	*         or <tt>null</tt> if there was no mapping for the key
2933	>	*         or {@code null} if there was no mapping for the key
2934		* @throws NullPointerException if the specified key or value is null
2935		*/
2936		public V replace(K key, V value) {
2937	<	int hash = hash(key.hashCode());
1108	<	if (value == null)
2937	>	if (key == null || value == null)
2938		throw new NullPointerException();
2939	<	Segment<K,V> s = segmentForHash(hash);
1111	<	return s == null ? null : s.replace(key, hash, value);
2939	>	return internalReplace(key, value, null);
2940		}
2941
2942		/**
2943		* Removes all of the mappings from this map.
2944		*/
2945		public void clear() {
2946	<	final Segment<K,V>[] segments = this.segments;
1119	<	for (int j = 0; j < segments.length; ++j) {
1120	<	Segment<K,V> s = segmentAt(segments, j);
1121	<	if (s != null)
1122	<	s.clear();
1123	<	}
2946	>	internalClear();
2947		}
2948
2949		/**
2950		* Returns a {@link Set} view of the keys contained in this map.
2951		* The set is backed by the map, so changes to the map are
2952	<	* reflected in the set, and vice-versa.  The set supports element
1130	<	* removal, which removes the corresponding mapping from this map,
1131	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1132	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1133	<	* operations.  It does not support the <tt>add</tt> or
1134	<	* <tt>addAll</tt> operations.
2952	>	* reflected in the set, and vice-versa.
2953		*
2954	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1137	<	* that will never throw {@link ConcurrentModificationException},
1138	<	* and guarantees to traverse elements as they existed upon
1139	<	* construction of the iterator, and may (but is not guaranteed to)
1140	<	* reflect any modifications subsequent to construction.
2954	>	* @return the set view
2955		*/
2956	<	public Set<K> keySet() {
2957	<	Set<K> ks = keySet;
2958	<	return (ks != null) ? ks : (keySet = new KeySet());
2956	>	public KeySetView<K,V> keySet() {
2957	>	KeySetView<K,V> ks = keySet;
2958	>	return (ks != null) ? ks : (keySet = new KeySetView<K,V>(this, null));
2959	>	}
2960	>
2961	>	/**
2962	>	* Returns a {@link Set} view of the keys in this map, using the
2963	>	* given common mapped value for any additions (i.e., {@link
2964	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2965	>	* This is of course only appropriate if it is acceptable to use
2966	>	* the same value for all additions from this view.
2967	>	*
2968	>	* @param mappedValue the mapped value to use for any additions
2969	>	* @return the set view
2970	>	* @throws NullPointerException if the mappedValue is null
2971	>	*/
2972	>	public KeySetView<K,V> keySet(V mappedValue) {
2973	>	if (mappedValue == null)
2974	>	throw new NullPointerException();
2975	>	return new KeySetView<K,V>(this, mappedValue);
2976		}
2977
2978		/**
2979		* Returns a {@link Collection} view of the values contained in this map.
2980		* The collection is backed by the map, so changes to the map are
2981	<	* reflected in the collection, and vice-versa.  The collection
1151	<	* supports element removal, which removes the corresponding
1152	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1153	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1154	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1155	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
2981	>	* reflected in the collection, and vice-versa.
2982		*
2983	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1158	<	* that will never throw {@link ConcurrentModificationException},
1159	<	* and guarantees to traverse elements as they existed upon
1160	<	* construction of the iterator, and may (but is not guaranteed to)
1161	<	* reflect any modifications subsequent to construction.
2983	>	* @return the collection view
2984		*/
2985	<	public Collection<V> values() {
2986	<	Collection<V> vs = values;
2987	<	return (vs != null) ? vs : (values = new Values());
2985	>	public ValuesView<K,V> values() {
2986	>	ValuesView<K,V> vs = values;
2987	>	return (vs != null) ? vs : (values = new ValuesView<K,V>(this));
2988		}
2989
2990		/**
#	Line 1170 | Line 2992 | public class ConcurrentHashMap<K, V> ext
2992		* The set is backed by the map, so changes to the map are
2993		* reflected in the set, and vice-versa.  The set supports element
2994		* removal, which removes the corresponding mapping from the map,
2995	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2996	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2997	<	* operations.  It does not support the <tt>add</tt> or
2998	<	* <tt>addAll</tt> operations.
2995	>	* via the {@code Iterator.remove}, {@code Set.remove},
2996	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
2997	>	* operations.  It does not support the {@code add} or
2998	>	* {@code addAll} operations.
2999		*
3000	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
3000	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
3001		* that will never throw {@link ConcurrentModificationException},
3002		* and guarantees to traverse elements as they existed upon
3003		* construction of the iterator, and may (but is not guaranteed to)
3004		* reflect any modifications subsequent to construction.
3005	+	*
3006	+	* @return the set view
3007		*/
3008		public Set<Map.Entry<K,V>> entrySet() {
3009	<	Set<Map.Entry<K,V>> es = entrySet;
3010	<	return (es != null) ? es : (entrySet = new EntrySet());
3009	>	EntrySetView<K,V> es = entrySet;
3010	>	return (es != null) ? es : (entrySet = new EntrySetView<K,V>(this));
3011		}
3012
3013		/**
#	Line 1193 | Line 3017 | public class ConcurrentHashMap<K, V> ext
3017		* @see #keySet()
3018		*/
3019		public Enumeration<K> keys() {
3020	<	return new KeyIterator();
3020	>	return new KeyIterator<K,V>(this);
3021		}
3022
3023		/**
#	Line 1203 | Line 3027 | public class ConcurrentHashMap<K, V> ext
3027		* @see #values()
3028		*/
3029		public Enumeration<V> elements() {
3030	<	return new ValueIterator();
3030	>	return new ValueIterator<K,V>(this);
3031		}
3032
3033	<	/* ---------------- Iterator Support -------------- */
3034	<
3035	<	abstract class HashIterator {
3036	<	int nextSegmentIndex;
3037	<	int nextTableIndex;
3038	<	HashEntry<K,V>[] currentTable;
3039	<	HashEntry<K, V> nextEntry;
3040	<	HashEntry<K, V> lastReturned;
3041	<
3042	<	HashIterator() {
3043	<	nextSegmentIndex = segments.length - 1;
3044	<	nextTableIndex = -1;
3045	<	advance();
3046	<	}
3033	>	/**
3034	>	* Returns the hash code value for this {@link Map}, i.e.,
3035	>	* the sum of, for each key-value pair in the map,
3036	>	* {@code key.hashCode() ^ value.hashCode()}.
3037	>	*
3038	>	* @return the hash code value for this map
3039	>	*/
3040	>	public int hashCode() {
3041	>	int h = 0;
3042	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3043	>	V v;
3044	>	while ((v = it.advanceValue()) != null) {
3045	>	h += it.nextKey.hashCode() ^ v.hashCode();
3046	>	}
3047	>	return h;
3048	>	}
3049
3050	<	/**
3051	<	* Sets nextEntry to first node of next non-empty table
3052	<	* (in backwards order, to simplify checks).
3053	<	*/
3054	<	final void advance() {
3050	>	/**
3051	>	* Returns a string representation of this map.  The string
3052	>	* representation consists of a list of key-value mappings (in no
3053	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
3054	>	* mappings are separated by the characters {@code ", "} (comma
3055	>	* and space).  Each key-value mapping is rendered as the key
3056	>	* followed by an equals sign ("{@code =}") followed by the
3057	>	* associated value.
3058	>	*
3059	>	* @return a string representation of this map
3060	>	*/
3061	>	public String toString() {
3062	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3063	>	StringBuilder sb = new StringBuilder();
3064	>	sb.append('{');
3065	>	V v;
3066	>	if ((v = it.advanceValue()) != null) {
3067		for (;;) {
3068	<	if (nextTableIndex >= 0) {
3069	<	if ((nextEntry = entryAt(currentTable,
3070	<	nextTableIndex--)) != null)
3071	<	break;
3072	<	}
1235	<	else if (nextSegmentIndex >= 0) {
1236	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
1237	<	if (seg != null && (currentTable = seg.table) != null)
1238	<	nextTableIndex = currentTable.length - 1;
1239	<	}
1240	<	else
3068	>	K k = it.nextKey;
3069	>	sb.append(k == this ? "(this Map)" : k);
3070	>	sb.append('=');
3071	>	sb.append(v == this ? "(this Map)" : v);
3072	>	if ((v = it.advanceValue()) == null)
3073		break;
3074	+	sb.append(',').append(' ');
3075		}
3076		}
3077	+	return sb.append('}').toString();
3078	+	}
3079
3080	<	final HashEntry<K,V> nextEntry() {
3081	<	HashEntry<K,V> e = nextEntry;
3082	<	if (e == null)
3080	>	/**
3081	>	* Compares the specified object with this map for equality.
3082	>	* Returns {@code true} if the given object is a map with the same
3083	>	* mappings as this map.  This operation may return misleading
3084	>	* results if either map is concurrently modified during execution
3085	>	* of this method.
3086	>	*
3087	>	* @param o object to be compared for equality with this map
3088	>	* @return {@code true} if the specified object is equal to this map
3089	>	*/
3090	>	public boolean equals(Object o) {
3091	>	if (o != this) {
3092	>	if (!(o instanceof Map))
3093	>	return false;
3094	>	Map<?,?> m = (Map<?,?>) o;
3095	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3096	>	V val;
3097	>	while ((val = it.advanceValue()) != null) {
3098	>	Object v = m.get(it.nextKey);
3099	>	if (v == null || (v != val && !v.equals(val)))
3100	>	return false;
3101	>	}
3102	>	for (Map.Entry<?,?> e : m.entrySet()) {
3103	>	Object mk, mv, v;
3104	>	if ((mk = e.getKey()) == null ||
3105	>	(mv = e.getValue()) == null ||
3106	>	(v = internalGet(mk)) == null ||
3107	>	(mv != v && !mv.equals(v)))
3108	>	return false;
3109	>	}
3110	>	}
3111	>	return true;
3112	>	}
3113	>
3114	>	/* ----------------Iterators -------------- */
3115	>
3116	>	@SuppressWarnings("serial") static final class KeyIterator<K,V>
3117	>	extends Traverser<K,V,Object>
3118	>	implements Spliterator<K>, Iterator<K>, Enumeration<K> {
3119	>	KeyIterator(ConcurrentHashMap<K,V> map) { super(map); }
3120	>	KeyIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3121	>	super(map, it);
3122	>	}
3123	>	public Spliterator<K> trySplit() {
3124	>	return (baseLimit - baseIndex <= 1) ? null :
3125	>	new KeyIterator<K,V>(map, this);
3126	>	}
3127	>	public final K next() {
3128	>	K k;
3129	>	if ((k = (nextVal == null) ? advanceKey() : nextKey) == null)
3130		throw new NoSuchElementException();
3131	<	lastReturned = e; // cannot assign until after null check
3132	<	if ((nextEntry = e.next) == null)
1251	<	advance();
1252	<	return e;
3131	>	nextVal = null;
3132	>	return k;
3133		}
3134
3135	<	public final boolean hasNext() { return nextEntry != null; }
1256	<	public final boolean hasMoreElements() { return nextEntry != null; }
3135	>	public final K nextElement() { return next(); }
3136
3137	<	public final void remove() {
3138	<	if (lastReturned == null)
3139	<	throw new IllegalStateException();
3140	<	ConcurrentHashMap.this.remove(lastReturned.key);
3141	<	lastReturned = null;
3137	>	public Iterator<K> iterator() { return this; }
3138	>
3139	>	public void forEachRemaining(Consumer<? super K> action) {
3140	>	forEachKey(action);
3141	>	}
3142	>
3143	>	public boolean tryAdvance(Consumer<? super K> block) {
3144	>	if (block == null) throw new NullPointerException();
3145	>	K k;
3146	>	if ((k = advanceKey()) == null)
3147	>	return false;
3148	>	block.accept(k);
3149	>	return true;
3150		}
3151	+
3152	+	public int characteristics() {
3153	+	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3154	+	Spliterator.NONNULL;
3155	+	}
3156	+
3157		}
3158
3159	<	final class KeyIterator
3160	<	extends HashIterator
3161	<	implements Iterator<K>, Enumeration<K>
3162	<	{
3163	<	public final K next()        { return super.nextEntry().key; }
3164	<	public final K nextElement() { return super.nextEntry().key; }
3159	>	@SuppressWarnings("serial") static final class ValueIterator<K,V>
3160	>	extends Traverser<K,V,Object>
3161	>	implements Spliterator<V>, Iterator<V>, Enumeration<V> {
3162	>	ValueIterator(ConcurrentHashMap<K,V> map) { super(map); }
3163	>	ValueIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3164	>	super(map, it);
3165	>	}
3166	>	public Spliterator<V> trySplit() {
3167	>	return (baseLimit - baseIndex <= 1) ? null :
3168	>	new ValueIterator<K,V>(map, this);
3169	>	}
3170	>
3171	>	public final V next() {
3172	>	V v;
3173	>	if ((v = nextVal) == null && (v = advanceValue()) == null)
3174	>	throw new NoSuchElementException();
3175	>	nextVal = null;
3176	>	return v;
3177	>	}
3178	>
3179	>	public final V nextElement() { return next(); }
3180	>
3181	>	public Iterator<V> iterator() { return this; }
3182	>
3183	>	public void forEachRemaining(Consumer<? super V> action) {
3184	>	forEachValue(action);
3185	>	}
3186	>
3187	>	public boolean tryAdvance(Consumer<? super V> block) {
3188	>	V v;
3189	>	if (block == null) throw new NullPointerException();
3190	>	if ((v = advanceValue()) == null)
3191	>	return false;
3192	>	block.accept(v);
3193	>	return true;
3194	>	}
3195	>
3196	>	public int characteristics() {
3197	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3198	>	}
3199		}
3200
3201	<	final class ValueIterator
3202	<	extends HashIterator
3203	<	implements Iterator<V>, Enumeration<V>
3204	<	{
3205	<	public final V next()        { return super.nextEntry().value; }
3206	<	public final V nextElement() { return super.nextEntry().value; }
3201	>	@SuppressWarnings("serial") static final class EntryIterator<K,V>
3202	>	extends Traverser<K,V,Object>
3203	>	implements Spliterator<Map.Entry<K,V>>, Iterator<Map.Entry<K,V>> {
3204	>	EntryIterator(ConcurrentHashMap<K,V> map) { super(map); }
3205	>	EntryIterator(ConcurrentHashMap<K,V> map, Traverser<K,V,Object> it) {
3206	>	super(map, it);
3207	>	}
3208	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3209	>	return (baseLimit - baseIndex <= 1) ? null :
3210	>	new EntryIterator<K,V>(map, this);
3211	>	}
3212	>
3213	>	public final Map.Entry<K,V> next() {
3214	>	V v;
3215	>	if ((v = nextVal) == null && (v = advanceValue()) == null)
3216	>	throw new NoSuchElementException();
3217	>	K k = nextKey;
3218	>	nextVal = null;
3219	>	return new MapEntry<K,V>(k, v, map);
3220	>	}
3221	>
3222	>	public Iterator<Map.Entry<K,V>> iterator() { return this; }
3223	>
3224	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3225	>	if (action == null) throw new NullPointerException();
3226	>	V v;
3227	>	while ((v = advanceValue()) != null)
3228	>	action.accept(entryFor(nextKey, v));
3229	>	}
3230	>
3231	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> block) {
3232	>	V v;
3233	>	if (block == null) throw new NullPointerException();
3234	>	if ((v = advanceValue()) == null)
3235	>	return false;
3236	>	block.accept(entryFor(nextKey, v));
3237	>	return true;
3238	>	}
3239	>
3240	>	public int characteristics() {
3241	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3242	>	Spliterator.NONNULL;
3243	>	}
3244		}
3245
3246		/**
3247	<	* Custom Entry class used by EntryIterator.next(), that relays
1284	<	* setValue changes to the underlying map.
3247	>	* Exported Entry for iterators
3248		*/
3249	<	final class WriteThroughEntry
3250	<	extends AbstractMap.SimpleEntry<K,V>
3251	<	{
3252	<	static final long serialVersionUID = 7249069246763182397L;
3253	<
3254	<	WriteThroughEntry(K k, V v) {
3255	<	super(k,v);
3249	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3250	>	final K key; // non-null
3251	>	V val;       // non-null
3252	>	final ConcurrentHashMap<K,V> map;
3253	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3254	>	this.key = key;
3255	>	this.val = val;
3256	>	this.map = map;
3257	>	}
3258	>	public final K getKey()       { return key; }
3259	>	public final V getValue()     { return val; }
3260	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
3261	>	public final String toString(){ return key + "=" + val; }
3262	>
3263	>	public final boolean equals(Object o) {
3264	>	Object k, v; Map.Entry<?,?> e;
3265	>	return ((o instanceof Map.Entry) &&
3266	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3267	>	(v = e.getValue()) != null &&
3268	>	(k == key || k.equals(key)) &&
3269	>	(v == val || v.equals(val)));
3270		}
3271
3272		/**
3273		* Sets our entry's value and writes through to the map. The
3274	<	* value to return is somewhat arbitrary here. Since a
3275	<	* WriteThroughEntry does not necessarily track asynchronous
3276	<	* changes, the most recent "previous" value could be
3277	<	* different from what we return (or could even have been
3278	<	* removed in which case the put will re-establish). We do not
1302	<	* and cannot guarantee more.
3274	>	* value to return is somewhat arbitrary here. Since we do not
3275	>	* necessarily track asynchronous changes, the most recent
3276	>	* "previous" value could be different from what we return (or
3277	>	* could even have been removed in which case the put will
3278	>	* re-establish). We do not and cannot guarantee more.
3279		*/
3280	<	public V setValue(V value) {
3280	>	public final V setValue(V value) {
3281		if (value == null) throw new NullPointerException();
3282	<	V v = super.setValue(value);
3283	<	ConcurrentHashMap.this.put(getKey(), value);
3282	>	V v = val;
3283	>	val = value;
3284	>	map.put(key, value);
3285		return v;
3286		}
3287		}
3288
3289	<	final class EntryIterator
3290	<	extends HashIterator
3291	<	implements Iterator<Entry<K,V>>
3292	<	{
3293	<	public Map.Entry<K,V> next() {
3294	<	HashEntry<K,V> e = super.nextEntry();
3295	<	return new WriteThroughEntry(e.key, e.value);
3296	<	}
3289	>	/**
3290	>	* Returns exportable snapshot entry for the given key and value
3291	>	* when write-through can't or shouldn't be used.
3292	>	*/
3293	>	static <K,V> AbstractMap.SimpleEntry<K,V> entryFor(K k, V v) {
3294	>	return new AbstractMap.SimpleEntry<K,V>(k, v);
3295	>	}
3296	>
3297	>	/* ---------------- Serialization Support -------------- */
3298	>
3299	>	/**
3300	>	* Stripped-down version of helper class used in previous version,
3301	>	* declared for the sake of serialization compatibility
3302	>	*/
3303	>	static class Segment<K,V> implements Serializable {
3304	>	private static final long serialVersionUID = 2249069246763182397L;
3305	>	final float loadFactor;
3306	>	Segment(float lf) { this.loadFactor = lf; }
3307		}
3308
3309	<	final class KeySet extends AbstractSet<K> {
3310	<	public Iterator<K> iterator() {
3311	<	return new KeyIterator();
3309	>	/**
3310	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
3311	>	* stream (i.e., serializes it).
3312	>	* @param s the stream
3313	>	* @serialData
3314	>	* the key (Object) and value (Object)
3315	>	* for each key-value mapping, followed by a null pair.
3316	>	* The key-value mappings are emitted in no particular order.
3317	>	*/
3318	>	@SuppressWarnings("unchecked") private void writeObject
3319	>	(java.io.ObjectOutputStream s)
3320	>	throws java.io.IOException {
3321	>	if (segments == null) { // for serialization compatibility
3322	>	segments = (Segment<K,V>[])
3323	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
3324	>	for (int i = 0; i < segments.length; ++i)
3325	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
3326		}
3327	<	public int size() {
3328	<	return ConcurrentHashMap.this.size();
3327	>	s.defaultWriteObject();
3328	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3329	>	V v;
3330	>	while ((v = it.advanceValue()) != null) {
3331	>	s.writeObject(it.nextKey);
3332	>	s.writeObject(v);
3333		}
3334	<	public boolean isEmpty() {
3335	<	return ConcurrentHashMap.this.isEmpty();
3334	>	s.writeObject(null);
3335	>	s.writeObject(null);
3336	>	segments = null; // throw away
3337	>	}
3338	>
3339	>	/**
3340	>	* Reconstitutes the instance from a stream (that is, deserializes it).
3341	>	* @param s the stream
3342	>	*/
3343	>	@SuppressWarnings("unchecked") private void readObject
3344	>	(java.io.ObjectInputStream s)
3345	>	throws java.io.IOException, ClassNotFoundException {
3346	>	s.defaultReadObject();
3347	>	this.segments = null; // unneeded
3348	>
3349	>	// Create all nodes, then place in table once size is known
3350	>	long size = 0L;
3351	>	Node<V> p = null;
3352	>	for (;;) {
3353	>	K k = (K) s.readObject();
3354	>	V v = (V) s.readObject();
3355	>	if (k != null && v != null) {
3356	>	int h = spread(k.hashCode());
3357	>	p = new Node<V>(h, k, v, p);
3358	>	++size;
3359	>	}
3360	>	else
3361	>	break;
3362		}
3363	<	public boolean contains(Object o) {
3364	<	return ConcurrentHashMap.this.containsKey(o);
3363	>	if (p != null) {
3364	>	boolean init = false;
3365	>	int n;
3366	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
3367	>	n = MAXIMUM_CAPACITY;
3368	>	else {
3369	>	int sz = (int)size;
3370	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
3371	>	}
3372	>	int sc = sizeCtl;
3373	>	boolean collide = false;
3374	>	if (n > sc &&
3375	>	U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
3376	>	try {
3377	>	if (table == null) {
3378	>	init = true;
3379	>	@SuppressWarnings("rawtypes") Node[] rt = new Node[n];
3380	>	Node<V>[] tab = (Node<V>[])rt;
3381	>	int mask = n - 1;
3382	>	while (p != null) {
3383	>	int j = p.hash & mask;
3384	>	Node<V> next = p.next;
3385	>	Node<V> q = p.next = tabAt(tab, j);
3386	>	setTabAt(tab, j, p);
3387	>	if (!collide && q != null && q.hash == p.hash)
3388	>	collide = true;
3389	>	p = next;
3390	>	}
3391	>	table = tab;
3392	>	addCount(size, -1);
3393	>	sc = n - (n >>> 2);
3394	>	}
3395	>	} finally {
3396	>	sizeCtl = sc;
3397	>	}
3398	>	if (collide) { // rescan and convert to TreeBins
3399	>	Node<V>[] tab = table;
3400	>	for (int i = 0; i < tab.length; ++i) {
3401	>	int c = 0;
3402	>	for (Node<V> e = tabAt(tab, i); e != null; e = e.next) {
3403	>	if (++c > TREE_THRESHOLD &&
3404	>	(e.key instanceof Comparable)) {
3405	>	replaceWithTreeBin(tab, i, e.key);
3406	>	break;
3407	>	}
3408	>	}
3409	>	}
3410	>	}
3411	>	}
3412	>	if (!init) { // Can only happen if unsafely published.
3413	>	while (p != null) {
3414	>	internalPut((K)p.key, p.val, false);
3415	>	p = p.next;
3416	>	}
3417	>	}
3418		}
3419	<	public boolean remove(Object o) {
3420	<	return ConcurrentHashMap.this.remove(o) != null;
3419	>	}
3420	>
3421	>	// -------------------------------------------------------
3422	>
3423	>	// Sequential bulk operations
3424	>
3425	>	/**
3426	>	* Performs the given action for each (key, value).
3427	>	*
3428	>	* @param action the action
3429	>	*/
3430	>	public void forEachSequentially
3431	>	(BiConsumer<? super K, ? super V> action) {
3432	>	if (action == null) throw new NullPointerException();
3433	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3434	>	V v;
3435	>	while ((v = it.advanceValue()) != null)
3436	>	action.accept(it.nextKey, v);
3437	>	}
3438	>
3439	>	/**
3440	>	* Performs the given action for each non-null transformation
3441	>	* of each (key, value).
3442	>	*
3443	>	* @param transformer a function returning the transformation
3444	>	* for an element, or null if there is no transformation (in
3445	>	* which case the action is not applied)
3446	>	* @param action the action
3447	>	*/
3448	>	public <U> void forEachSequentially
3449	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
3450	>	Consumer<? super U> action) {
3451	>	if (transformer == null || action == null)
3452	>	throw new NullPointerException();
3453	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3454	>	V v; U u;
3455	>	while ((v = it.advanceValue()) != null) {
3456	>	if ((u = transformer.apply(it.nextKey, v)) != null)
3457	>	action.accept(u);
3458		}
3459	<	public void clear() {
3460	<	ConcurrentHashMap.this.clear();
3459	>	}
3460	>
3461	>	/**
3462	>	* Returns a non-null result from applying the given search
3463	>	* function on each (key, value), or null if none.
3464	>	*
3465	>	* @param searchFunction a function returning a non-null
3466	>	* result on success, else null
3467	>	* @return a non-null result from applying the given search
3468	>	* function on each (key, value), or null if none
3469	>	*/
3470	>	public <U> U searchSequentially
3471	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3472	>	if (searchFunction == null) throw new NullPointerException();
3473	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3474	>	V v; U u;
3475	>	while ((v = it.advanceValue()) != null) {
3476	>	if ((u = searchFunction.apply(it.nextKey, v)) != null)
3477	>	return u;
3478		}
3479	+	return null;
3480	+	}
3481	+
3482	+	/**
3483	+	* Returns the result of accumulating the given transformation
3484	+	* of all (key, value) pairs using the given reducer to
3485	+	* combine values, or null if none.
3486	+	*
3487	+	* @param transformer a function returning the transformation
3488	+	* for an element, or null if there is no transformation (in
3489	+	* which case it is not combined)
3490	+	* @param reducer a commutative associative combining function
3491	+	* @return the result of accumulating the given transformation
3492	+	* of all (key, value) pairs
3493	+	*/
3494	+	public <U> U reduceSequentially
3495	+	(BiFunction<? super K, ? super V, ? extends U> transformer,
3496	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3497	+	if (transformer == null || reducer == null)
3498	+	throw new NullPointerException();
3499	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3500	+	U r = null, u; V v;
3501	+	while ((v = it.advanceValue()) != null) {
3502	+	if ((u = transformer.apply(it.nextKey, v)) != null)
3503	+	r = (r == null) ? u : reducer.apply(r, u);
3504	+	}
3505	+	return r;
3506	+	}
3507	+
3508	+	/**
3509	+	* Returns the result of accumulating the given transformation
3510	+	* of all (key, value) pairs using the given reducer to
3511	+	* combine values, and the given basis as an identity value.
3512	+	*
3513	+	* @param transformer a function returning the transformation
3514	+	* for an element
3515	+	* @param basis the identity (initial default value) for the reduction
3516	+	* @param reducer a commutative associative combining function
3517	+	* @return the result of accumulating the given transformation
3518	+	* of all (key, value) pairs
3519	+	*/
3520	+	public double reduceToDoubleSequentially
3521	+	(ToDoubleBiFunction<? super K, ? super V> transformer,
3522	+	double basis,
3523	+	DoubleBinaryOperator reducer) {
3524	+	if (transformer == null || reducer == null)
3525	+	throw new NullPointerException();
3526	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3527	+	double r = basis; V v;
3528	+	while ((v = it.advanceValue()) != null)
3529	+	r = reducer.applyAsDouble(r, transformer.applyAsDouble(it.nextKey, v));
3530	+	return r;
3531	+	}
3532	+
3533	+	/**
3534	+	* Returns the result of accumulating the given transformation
3535	+	* of all (key, value) pairs using the given reducer to
3536	+	* combine values, and the given basis as an identity value.
3537	+	*
3538	+	* @param transformer a function returning the transformation
3539	+	* for an element
3540	+	* @param basis the identity (initial default value) for the reduction
3541	+	* @param reducer a commutative associative combining function
3542	+	* @return the result of accumulating the given transformation
3543	+	* of all (key, value) pairs
3544	+	*/
3545	+	public long reduceToLongSequentially
3546	+	(ToLongBiFunction<? super K, ? super V> transformer,
3547	+	long basis,
3548	+	LongBinaryOperator reducer) {
3549	+	if (transformer == null || reducer == null)
3550	+	throw new NullPointerException();
3551	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3552	+	long r = basis; V v;
3553	+	while ((v = it.advanceValue()) != null)
3554	+	r = reducer.applyAsLong(r, transformer.applyAsLong(it.nextKey, v));
3555	+	return r;
3556	+	}
3557	+
3558	+	/**
3559	+	* Returns the result of accumulating the given transformation
3560	+	* of all (key, value) pairs using the given reducer to
3561	+	* combine values, and the given basis as an identity value.
3562	+	*
3563	+	* @param transformer a function returning the transformation
3564	+	* for an element
3565	+	* @param basis the identity (initial default value) for the reduction
3566	+	* @param reducer a commutative associative combining function
3567	+	* @return the result of accumulating the given transformation
3568	+	* of all (key, value) pairs
3569	+	*/
3570	+	public int reduceToIntSequentially
3571	+	(ToIntBiFunction<? super K, ? super V> transformer,
3572	+	int basis,
3573	+	IntBinaryOperator reducer) {
3574	+	if (transformer == null || reducer == null)
3575	+	throw new NullPointerException();
3576	+	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3577	+	int r = basis; V v;
3578	+	while ((v = it.advanceValue()) != null)
3579	+	r = reducer.applyAsInt(r, transformer.applyAsInt(it.nextKey, v));
3580	+	return r;
3581		}
3582
3583	<	final class Values extends AbstractCollection<V> {
3584	<	public Iterator<V> iterator() {
3585	<	return new ValueIterator();
3583	>	/**
3584	>	* Performs the given action for each key.
3585	>	*
3586	>	* @param action the action
3587	>	*/
3588	>	public void forEachKeySequentially
3589	>	(Consumer<? super K> action) {
3590	>	new Traverser<K,V,Object>(this).forEachKey(action);
3591	>	}
3592	>
3593	>	/**
3594	>	* Performs the given action for each non-null transformation
3595	>	* of each key.
3596	>	*
3597	>	* @param transformer a function returning the transformation
3598	>	* for an element, or null if there is no transformation (in
3599	>	* which case the action is not applied)
3600	>	* @param action the action
3601	>	*/
3602	>	public <U> void forEachKeySequentially
3603	>	(Function<? super K, ? extends U> transformer,
3604	>	Consumer<? super U> action) {
3605	>	if (transformer == null || action == null)
3606	>	throw new NullPointerException();
3607	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3608	>	K k; U u;
3609	>	while ((k = it.advanceKey()) != null) {
3610	>	if ((u = transformer.apply(k)) != null)
3611	>	action.accept(u);
3612		}
3613	<	public int size() {
3614	<	return ConcurrentHashMap.this.size();
3613	>	}
3614	>
3615	>	/**
3616	>	* Returns a non-null result from applying the given search
3617	>	* function on each key, or null if none.
3618	>	*
3619	>	* @param searchFunction a function returning a non-null
3620	>	* result on success, else null
3621	>	* @return a non-null result from applying the given search
3622	>	* function on each key, or null if none
3623	>	*/
3624	>	public <U> U searchKeysSequentially
3625	>	(Function<? super K, ? extends U> searchFunction) {
3626	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3627	>	K k; U u;
3628	>	while ((k = it.advanceKey()) != null) {
3629	>	if ((u = searchFunction.apply(k)) != null)
3630	>	return u;
3631		}
3632	<	public boolean isEmpty() {
3633	<	return ConcurrentHashMap.this.isEmpty();
3632	>	return null;
3633	>	}
3634	>
3635	>	/**
3636	>	* Returns the result of accumulating all keys using the given
3637	>	* reducer to combine values, or null if none.
3638	>	*
3639	>	* @param reducer a commutative associative combining function
3640	>	* @return the result of accumulating all keys using the given
3641	>	* reducer to combine values, or null if none
3642	>	*/
3643	>	public K reduceKeysSequentially
3644	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
3645	>	if (reducer == null) throw new NullPointerException();
3646	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3647	>	K u, r = null;
3648	>	while ((u = it.advanceKey()) != null) {
3649	>	r = (r == null) ? u : reducer.apply(r, u);
3650		}
3651	<	public boolean contains(Object o) {
3652	<	return ConcurrentHashMap.this.containsValue(o);
3651	>	return r;
3652	>	}
3653	>
3654	>	/**
3655	>	* Returns the result of accumulating the given transformation
3656	>	* of all keys using the given reducer to combine values, or
3657	>	* null if none.
3658	>	*
3659	>	* @param transformer a function returning the transformation
3660	>	* for an element, or null if there is no transformation (in
3661	>	* which case it is not combined)
3662	>	* @param reducer a commutative associative combining function
3663	>	* @return the result of accumulating the given transformation
3664	>	* of all keys
3665	>	*/
3666	>	public <U> U reduceKeysSequentially
3667	>	(Function<? super K, ? extends U> transformer,
3668	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3669	>	if (transformer == null || reducer == null)
3670	>	throw new NullPointerException();
3671	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3672	>	K k; U r = null, u;
3673	>	while ((k = it.advanceKey()) != null) {
3674	>	if ((u = transformer.apply(k)) != null)
3675	>	r = (r == null) ? u : reducer.apply(r, u);
3676		}
3677	<	public void clear() {
3678	<	ConcurrentHashMap.this.clear();
3677	>	return r;
3678	>	}
3679	>
3680	>	/**
3681	>	* Returns the result of accumulating the given transformation
3682	>	* of all keys using the given reducer to combine values, and
3683	>	* the given basis as an identity value.
3684	>	*
3685	>	* @param transformer a function returning the transformation
3686	>	* for an element
3687	>	* @param basis the identity (initial default value) for the reduction
3688	>	* @param reducer a commutative associative combining function
3689	>	* @return the result of accumulating the given transformation
3690	>	* of all keys
3691	>	*/
3692	>	public double reduceKeysToDoubleSequentially
3693	>	(ToDoubleFunction<? super K> transformer,
3694	>	double basis,
3695	>	DoubleBinaryOperator reducer) {
3696	>	if (transformer == null || reducer == null)
3697	>	throw new NullPointerException();
3698	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3699	>	double r = basis;
3700	>	K k;
3701	>	while ((k = it.advanceKey()) != null)
3702	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(k));
3703	>	return r;
3704	>	}
3705	>
3706	>	/**
3707	>	* Returns the result of accumulating the given transformation
3708	>	* of all keys using the given reducer to combine values, and
3709	>	* the given basis as an identity value.
3710	>	*
3711	>	* @param transformer a function returning the transformation
3712	>	* for an element
3713	>	* @param basis the identity (initial default value) for the reduction
3714	>	* @param reducer a commutative associative combining function
3715	>	* @return the result of accumulating the given transformation
3716	>	* of all keys
3717	>	*/
3718	>	public long reduceKeysToLongSequentially
3719	>	(ToLongFunction<? super K> transformer,
3720	>	long basis,
3721	>	LongBinaryOperator reducer) {
3722	>	if (transformer == null || reducer == null)
3723	>	throw new NullPointerException();
3724	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3725	>	long r = basis;
3726	>	K k;
3727	>	while ((k = it.advanceKey()) != null)
3728	>	r = reducer.applyAsLong(r, transformer.applyAsLong(k));
3729	>	return r;
3730	>	}
3731	>
3732	>	/**
3733	>	* Returns the result of accumulating the given transformation
3734	>	* of all keys using the given reducer to combine values, and
3735	>	* the given basis as an identity value.
3736	>	*
3737	>	* @param transformer a function returning the transformation
3738	>	* for an element
3739	>	* @param basis the identity (initial default value) for the reduction
3740	>	* @param reducer a commutative associative combining function
3741	>	* @return the result of accumulating the given transformation
3742	>	* of all keys
3743	>	*/
3744	>	public int reduceKeysToIntSequentially
3745	>	(ToIntFunction<? super K> transformer,
3746	>	int basis,
3747	>	IntBinaryOperator reducer) {
3748	>	if (transformer == null || reducer == null)
3749	>	throw new NullPointerException();
3750	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3751	>	int r = basis;
3752	>	K k;
3753	>	while ((k = it.advanceKey()) != null)
3754	>	r = reducer.applyAsInt(r, transformer.applyAsInt(k));
3755	>	return r;
3756	>	}
3757	>
3758	>	/**
3759	>	* Performs the given action for each value.
3760	>	*
3761	>	* @param action the action
3762	>	*/
3763	>	public void forEachValueSequentially(Consumer<? super V> action) {
3764	>	new Traverser<K,V,Object>(this).forEachValue(action);
3765	>	}
3766	>
3767	>	/**
3768	>	* Performs the given action for each non-null transformation
3769	>	* of each value.
3770	>	*
3771	>	* @param transformer a function returning the transformation
3772	>	* for an element, or null if there is no transformation (in
3773	>	* which case the action is not applied)
3774	>	* @param action the action
3775	>	*/
3776	>	public <U> void forEachValueSequentially
3777	>	(Function<? super V, ? extends U> transformer,
3778	>	Consumer<? super U> action) {
3779	>	if (transformer == null || action == null)
3780	>	throw new NullPointerException();
3781	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3782	>	V v; U u;
3783	>	while ((v = it.advanceValue()) != null) {
3784	>	if ((u = transformer.apply(v)) != null)
3785	>	action.accept(u);
3786		}
3787		}
3788
3789	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
3790	<	public Iterator<Map.Entry<K,V>> iterator() {
3791	<	return new EntryIterator();
3789	>	/**
3790	>	* Returns a non-null result from applying the given search
3791	>	* function on each value, or null if none.
3792	>	*
3793	>	* @param searchFunction a function returning a non-null
3794	>	* result on success, else null
3795	>	* @return a non-null result from applying the given search
3796	>	* function on each value, or null if none
3797	>	*/
3798	>	public <U> U searchValuesSequentially
3799	>	(Function<? super V, ? extends U> searchFunction) {
3800	>	if (searchFunction == null) throw new NullPointerException();
3801	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3802	>	V v; U u;
3803	>	while ((v = it.advanceValue()) != null) {
3804	>	if ((u = searchFunction.apply(v)) != null)
3805	>	return u;
3806		}
3807	<	public boolean contains(Object o) {
3808	<	if (!(o instanceof Map.Entry))
3809	<	return false;
3810	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3811	<	V v = ConcurrentHashMap.this.get(e.getKey());
3812	<	return v != null && v.equals(e.getValue());
3807	>	return null;
3808	>	}
3809	>
3810	>	/**
3811	>	* Returns the result of accumulating all values using the
3812	>	* given reducer to combine values, or null if none.
3813	>	*
3814	>	* @param reducer a commutative associative combining function
3815	>	* @return the result of accumulating all values
3816	>	*/
3817	>	public V reduceValuesSequentially
3818	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
3819	>	if (reducer == null) throw new NullPointerException();
3820	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3821	>	V r = null; V v;
3822	>	while ((v = it.advanceValue()) != null)
3823	>	r = (r == null) ? v : reducer.apply(r, v);
3824	>	return r;
3825	>	}
3826	>
3827	>	/**
3828	>	* Returns the result of accumulating the given transformation
3829	>	* of all values using the given reducer to combine values, or
3830	>	* null if none.
3831	>	*
3832	>	* @param transformer a function returning the transformation
3833	>	* for an element, or null if there is no transformation (in
3834	>	* which case it is not combined)
3835	>	* @param reducer a commutative associative combining function
3836	>	* @return the result of accumulating the given transformation
3837	>	* of all values
3838	>	*/
3839	>	public <U> U reduceValuesSequentially
3840	>	(Function<? super V, ? extends U> transformer,
3841	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3842	>	if (transformer == null || reducer == null)
3843	>	throw new NullPointerException();
3844	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3845	>	U r = null, u; V v;
3846	>	while ((v = it.advanceValue()) != null) {
3847	>	if ((u = transformer.apply(v)) != null)
3848	>	r = (r == null) ? u : reducer.apply(r, u);
3849		}
3850	<	public boolean remove(Object o) {
3851	<	if (!(o instanceof Map.Entry))
3852	<	return false;
3853	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
3854	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
3850	>	return r;
3851	>	}
3852	>
3853	>	/**
3854	>	* Returns the result of accumulating the given transformation
3855	>	* of all values using the given reducer to combine values,
3856	>	* and the given basis as an identity value.
3857	>	*
3858	>	* @param transformer a function returning the transformation
3859	>	* for an element
3860	>	* @param basis the identity (initial default value) for the reduction
3861	>	* @param reducer a commutative associative combining function
3862	>	* @return the result of accumulating the given transformation
3863	>	* of all values
3864	>	*/
3865	>	public double reduceValuesToDoubleSequentially
3866	>	(ToDoubleFunction<? super V> transformer,
3867	>	double basis,
3868	>	DoubleBinaryOperator reducer) {
3869	>	if (transformer == null || reducer == null)
3870	>	throw new NullPointerException();
3871	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3872	>	double r = basis; V v;
3873	>	while ((v = it.advanceValue()) != null)
3874	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
3875	>	return r;
3876	>	}
3877	>
3878	>	/**
3879	>	* Returns the result of accumulating the given transformation
3880	>	* of all values using the given reducer to combine values,
3881	>	* and the given basis as an identity value.
3882	>	*
3883	>	* @param transformer a function returning the transformation
3884	>	* for an element
3885	>	* @param basis the identity (initial default value) for the reduction
3886	>	* @param reducer a commutative associative combining function
3887	>	* @return the result of accumulating the given transformation
3888	>	* of all values
3889	>	*/
3890	>	public long reduceValuesToLongSequentially
3891	>	(ToLongFunction<? super V> transformer,
3892	>	long basis,
3893	>	LongBinaryOperator reducer) {
3894	>	if (transformer == null || reducer == null)
3895	>	throw new NullPointerException();
3896	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3897	>	long r = basis; V v;
3898	>	while ((v = it.advanceValue()) != null)
3899	>	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
3900	>	return r;
3901	>	}
3902	>
3903	>	/**
3904	>	* Returns the result of accumulating the given transformation
3905	>	* of all values using the given reducer to combine values,
3906	>	* and the given basis as an identity value.
3907	>	*
3908	>	* @param transformer a function returning the transformation
3909	>	* for an element
3910	>	* @param basis the identity (initial default value) for the reduction
3911	>	* @param reducer a commutative associative combining function
3912	>	* @return the result of accumulating the given transformation
3913	>	* of all values
3914	>	*/
3915	>	public int reduceValuesToIntSequentially
3916	>	(ToIntFunction<? super V> transformer,
3917	>	int basis,
3918	>	IntBinaryOperator reducer) {
3919	>	if (transformer == null || reducer == null)
3920	>	throw new NullPointerException();
3921	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3922	>	int r = basis; V v;
3923	>	while ((v = it.advanceValue()) != null)
3924	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
3925	>	return r;
3926	>	}
3927	>
3928	>	/**
3929	>	* Performs the given action for each entry.
3930	>	*
3931	>	* @param action the action
3932	>	*/
3933	>	public void forEachEntrySequentially
3934	>	(Consumer<? super Map.Entry<K,V>> action) {
3935	>	if (action == null) throw new NullPointerException();
3936	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3937	>	V v;
3938	>	while ((v = it.advanceValue()) != null)
3939	>	action.accept(entryFor(it.nextKey, v));
3940	>	}
3941	>
3942	>	/**
3943	>	* Performs the given action for each non-null transformation
3944	>	* of each entry.
3945	>	*
3946	>	* @param transformer a function returning the transformation
3947	>	* for an element, or null if there is no transformation (in
3948	>	* which case the action is not applied)
3949	>	* @param action the action
3950	>	*/
3951	>	public <U> void forEachEntrySequentially
3952	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
3953	>	Consumer<? super U> action) {
3954	>	if (transformer == null || action == null)
3955	>	throw new NullPointerException();
3956	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3957	>	V v; U u;
3958	>	while ((v = it.advanceValue()) != null) {
3959	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
3960	>	action.accept(u);
3961		}
3962	<	public int size() {
3963	<	return ConcurrentHashMap.this.size();
3962	>	}
3963	>
3964	>	/**
3965	>	* Returns a non-null result from applying the given search
3966	>	* function on each entry, or null if none.
3967	>	*
3968	>	* @param searchFunction a function returning a non-null
3969	>	* result on success, else null
3970	>	* @return a non-null result from applying the given search
3971	>	* function on each entry, or null if none
3972	>	*/
3973	>	public <U> U searchEntriesSequentially
3974	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
3975	>	if (searchFunction == null) throw new NullPointerException();
3976	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3977	>	V v; U u;
3978	>	while ((v = it.advanceValue()) != null) {
3979	>	if ((u = searchFunction.apply(entryFor(it.nextKey, v))) != null)
3980	>	return u;
3981		}
3982	<	public boolean isEmpty() {
3983	<	return ConcurrentHashMap.this.isEmpty();
3982	>	return null;
3983	>	}
3984	>
3985	>	/**
3986	>	* Returns the result of accumulating all entries using the
3987	>	* given reducer to combine values, or null if none.
3988	>	*
3989	>	* @param reducer a commutative associative combining function
3990	>	* @return the result of accumulating all entries
3991	>	*/
3992	>	public Map.Entry<K,V> reduceEntriesSequentially
3993	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
3994	>	if (reducer == null) throw new NullPointerException();
3995	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
3996	>	Map.Entry<K,V> r = null; V v;
3997	>	while ((v = it.advanceValue()) != null) {
3998	>	Map.Entry<K,V> u = entryFor(it.nextKey, v);
3999	>	r = (r == null) ? u : reducer.apply(r, u);
4000		}
4001	<	public void clear() {
4002	<	ConcurrentHashMap.this.clear();
4001	>	return r;
4002	>	}
4003	>
4004	>	/**
4005	>	* Returns the result of accumulating the given transformation
4006	>	* of all entries using the given reducer to combine values,
4007	>	* or null if none.
4008	>	*
4009	>	* @param transformer a function returning the transformation
4010	>	* for an element, or null if there is no transformation (in
4011	>	* which case it is not combined)
4012	>	* @param reducer a commutative associative combining function
4013	>	* @return the result of accumulating the given transformation
4014	>	* of all entries
4015	>	*/
4016	>	public <U> U reduceEntriesSequentially
4017	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4018	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4019	>	if (transformer == null || reducer == null)
4020	>	throw new NullPointerException();
4021	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4022	>	U r = null, u; V v;
4023	>	while ((v = it.advanceValue()) != null) {
4024	>	if ((u = transformer.apply(entryFor(it.nextKey, v))) != null)
4025	>	r = (r == null) ? u : reducer.apply(r, u);
4026		}
4027	+	return r;
4028		}
4029
4030	<	/* ---------------- Serialization Support -------------- */
4030	>	/**
4031	>	* Returns the result of accumulating the given transformation
4032	>	* of all entries using the given reducer to combine values,
4033	>	* and the given basis as an identity value.
4034	>	*
4035	>	* @param transformer a function returning the transformation
4036	>	* for an element
4037	>	* @param basis the identity (initial default value) for the reduction
4038	>	* @param reducer a commutative associative combining function
4039	>	* @return the result of accumulating the given transformation
4040	>	* of all entries
4041	>	*/
4042	>	public double reduceEntriesToDoubleSequentially
4043	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
4044	>	double basis,
4045	>	DoubleBinaryOperator reducer) {
4046	>	if (transformer == null || reducer == null)
4047	>	throw new NullPointerException();
4048	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4049	>	double r = basis; V v;
4050	>	while ((v = it.advanceValue()) != null)
4051	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(it.nextKey, v)));
4052	>	return r;
4053	>	}
4054
4055		/**
4056	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4057	<	* stream (i.e., serializes it).
4058	<	* @param s the stream
4059	<	* @serialData
4060	<	* the key (Object) and value (Object)
4061	<	* for each key-value mapping, followed by a null pair.
4062	<	* The key-value mappings are emitted in no particular order.
4056	>	* Returns the result of accumulating the given transformation
4057	>	* of all entries using the given reducer to combine values,
4058	>	* and the given basis as an identity value.
4059	>	*
4060	>	* @param transformer a function returning the transformation
4061	>	* for an element
4062	>	* @param basis the identity (initial default value) for the reduction
4063	>	* @param reducer a commutative associative combining function
4064	>	* @return the result of accumulating the given transformation
4065	>	* of all entries
4066	>	*/
4067	>	public long reduceEntriesToLongSequentially
4068	>	(ToLongFunction<Map.Entry<K,V>> transformer,
4069	>	long basis,
4070	>	LongBinaryOperator reducer) {
4071	>	if (transformer == null || reducer == null)
4072	>	throw new NullPointerException();
4073	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4074	>	long r = basis; V v;
4075	>	while ((v = it.advanceValue()) != null)
4076	>	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(it.nextKey, v)));
4077	>	return r;
4078	>	}
4079	>
4080	>	/**
4081	>	* Returns the result of accumulating the given transformation
4082	>	* of all entries using the given reducer to combine values,
4083	>	* and the given basis as an identity value.
4084	>	*
4085	>	* @param transformer a function returning the transformation
4086	>	* for an element
4087	>	* @param basis the identity (initial default value) for the reduction
4088	>	* @param reducer a commutative associative combining function
4089	>	* @return the result of accumulating the given transformation
4090	>	* of all entries
4091	>	*/
4092	>	public int reduceEntriesToIntSequentially
4093	>	(ToIntFunction<Map.Entry<K,V>> transformer,
4094	>	int basis,
4095	>	IntBinaryOperator reducer) {
4096	>	if (transformer == null || reducer == null)
4097	>	throw new NullPointerException();
4098	>	Traverser<K,V,Object> it = new Traverser<K,V,Object>(this);
4099	>	int r = basis; V v;
4100	>	while ((v = it.advanceValue()) != null)
4101	>	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(it.nextKey, v)));
4102	>	return r;
4103	>	}
4104	>
4105	>	// Parallel bulk operations
4106	>
4107	>	/**
4108	>	* Performs the given action for each (key, value).
4109	>	*
4110	>	* @param action the action
4111		*/
4112	<	private void writeObject(java.io.ObjectOutputStream s)
4113	<	throws java.io.IOException {
4114	<	// force all segments for serialization compatibility
4115	<	for (int k = 0; k < segments.length; ++k)
1404	<	ensureSegment(k);
1405	<	s.defaultWriteObject();
4112	>	public void forEachInParallel(BiConsumer<? super K,? super V> action) {
4113	>	ForkJoinTasks.forEach
4114	>	(this, action).invoke();
4115	>	}
4116
4117	<	final Segment<K,V>[] segments = this.segments;
4118	<	for (int k = 0; k < segments.length; ++k) {
4119	<	Segment<K,V> seg = segmentAt(segments, k);
4120	<	seg.lock();
4121	<	try {
4122	<	HashEntry<K,V>[] tab = seg.table;
4123	<	for (int i = 0; i < tab.length; ++i) {
4124	<	HashEntry<K,V> e;
4125	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4126	<	s.writeObject(e.key);
4127	<	s.writeObject(e.value);
4117	>	/**
4118	>	* Performs the given action for each non-null transformation
4119	>	* of each (key, value).
4120	>	*
4121	>	* @param transformer a function returning the transformation
4122	>	* for an element, or null if there is no transformation (in
4123	>	* which case the action is not applied)
4124	>	* @param action the action
4125	>	*/
4126	>	public <U> void forEachInParallel
4127	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
4128	>	Consumer<? super U> action) {
4129	>	ForkJoinTasks.forEach
4130	>	(this, transformer, action).invoke();
4131	>	}
4132	>
4133	>	/**
4134	>	* Returns a non-null result from applying the given search
4135	>	* function on each (key, value), or null if none.  Upon
4136	>	* success, further element processing is suppressed and the
4137	>	* results of any other parallel invocations of the search
4138	>	* function are ignored.
4139	>	*
4140	>	* @param searchFunction a function returning a non-null
4141	>	* result on success, else null
4142	>	* @return a non-null result from applying the given search
4143	>	* function on each (key, value), or null if none
4144	>	*/
4145	>	public <U> U searchInParallel
4146	>	(BiFunction<? super K, ? super V, ? extends U> searchFunction) {
4147	>	return ForkJoinTasks.search
4148	>	(this, searchFunction).invoke();
4149	>	}
4150	>
4151	>	/**
4152	>	* Returns the result of accumulating the given transformation
4153	>	* of all (key, value) pairs using the given reducer to
4154	>	* combine values, or null if none.
4155	>	*
4156	>	* @param transformer a function returning the transformation
4157	>	* for an element, or null if there is no transformation (in
4158	>	* which case it is not combined)
4159	>	* @param reducer a commutative associative combining function
4160	>	* @return the result of accumulating the given transformation
4161	>	* of all (key, value) pairs
4162	>	*/
4163	>	public <U> U reduceInParallel
4164	>	(BiFunction<? super K, ? super V, ? extends U> transformer,
4165	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4166	>	return ForkJoinTasks.reduce
4167	>	(this, transformer, reducer).invoke();
4168	>	}
4169	>
4170	>	/**
4171	>	* Returns the result of accumulating the given transformation
4172	>	* of all (key, value) pairs using the given reducer to
4173	>	* combine values, and the given basis as an identity value.
4174	>	*
4175	>	* @param transformer a function returning the transformation
4176	>	* for an element
4177	>	* @param basis the identity (initial default value) for the reduction
4178	>	* @param reducer a commutative associative combining function
4179	>	* @return the result of accumulating the given transformation
4180	>	* of all (key, value) pairs
4181	>	*/
4182	>	public double reduceToDoubleInParallel
4183	>	(ToDoubleBiFunction<? super K, ? super V> transformer,
4184	>	double basis,
4185	>	DoubleBinaryOperator reducer) {
4186	>	return ForkJoinTasks.reduceToDouble
4187	>	(this, transformer, basis, reducer).invoke();
4188	>	}
4189	>
4190	>	/**
4191	>	* Returns the result of accumulating the given transformation
4192	>	* of all (key, value) pairs using the given reducer to
4193	>	* combine values, and the given basis as an identity value.
4194	>	*
4195	>	* @param transformer a function returning the transformation
4196	>	* for an element
4197	>	* @param basis the identity (initial default value) for the reduction
4198	>	* @param reducer a commutative associative combining function
4199	>	* @return the result of accumulating the given transformation
4200	>	* of all (key, value) pairs
4201	>	*/
4202	>	public long reduceToLongInParallel
4203	>	(ToLongBiFunction<? super K, ? super V> transformer,
4204	>	long basis,
4205	>	LongBinaryOperator reducer) {
4206	>	return ForkJoinTasks.reduceToLong
4207	>	(this, transformer, basis, reducer).invoke();
4208	>	}
4209	>
4210	>	/**
4211	>	* Returns the result of accumulating the given transformation
4212	>	* of all (key, value) pairs using the given reducer to
4213	>	* combine values, and the given basis as an identity value.
4214	>	*
4215	>	* @param transformer a function returning the transformation
4216	>	* for an element
4217	>	* @param basis the identity (initial default value) for the reduction
4218	>	* @param reducer a commutative associative combining function
4219	>	* @return the result of accumulating the given transformation
4220	>	* of all (key, value) pairs
4221	>	*/
4222	>	public int reduceToIntInParallel
4223	>	(ToIntBiFunction<? super K, ? super V> transformer,
4224	>	int basis,
4225	>	IntBinaryOperator reducer) {
4226	>	return ForkJoinTasks.reduceToInt
4227	>	(this, transformer, basis, reducer).invoke();
4228	>	}
4229	>
4230	>	/**
4231	>	* Performs the given action for each key.
4232	>	*
4233	>	* @param action the action
4234	>	*/
4235	>	public void forEachKeyInParallel(Consumer<? super K> action) {
4236	>	ForkJoinTasks.forEachKey
4237	>	(this, action).invoke();
4238	>	}
4239	>
4240	>	/**
4241	>	* Performs the given action for each non-null transformation
4242	>	* of each key.
4243	>	*
4244	>	* @param transformer a function returning the transformation
4245	>	* for an element, or null if there is no transformation (in
4246	>	* which case the action is not applied)
4247	>	* @param action the action
4248	>	*/
4249	>	public <U> void forEachKeyInParallel
4250	>	(Function<? super K, ? extends U> transformer,
4251	>	Consumer<? super U> action) {
4252	>	ForkJoinTasks.forEachKey
4253	>	(this, transformer, action).invoke();
4254	>	}
4255	>
4256	>	/**
4257	>	* Returns a non-null result from applying the given search
4258	>	* function on each key, or null if none. Upon success,
4259	>	* further element processing is suppressed and the results of
4260	>	* any other parallel invocations of the search function are
4261	>	* ignored.
4262	>	*
4263	>	* @param searchFunction a function returning a non-null
4264	>	* result on success, else null
4265	>	* @return a non-null result from applying the given search
4266	>	* function on each key, or null if none
4267	>	*/
4268	>	public <U> U searchKeysInParallel
4269	>	(Function<? super K, ? extends U> searchFunction) {
4270	>	return ForkJoinTasks.searchKeys
4271	>	(this, searchFunction).invoke();
4272	>	}
4273	>
4274	>	/**
4275	>	* Returns the result of accumulating all keys using the given
4276	>	* reducer to combine values, or null if none.
4277	>	*
4278	>	* @param reducer a commutative associative combining function
4279	>	* @return the result of accumulating all keys using the given
4280	>	* reducer to combine values, or null if none
4281	>	*/
4282	>	public K reduceKeysInParallel
4283	>	(BiFunction<? super K, ? super K, ? extends K> reducer) {
4284	>	return ForkJoinTasks.reduceKeys
4285	>	(this, reducer).invoke();
4286	>	}
4287	>
4288	>	/**
4289	>	* Returns the result of accumulating the given transformation
4290	>	* of all keys using the given reducer to combine values, or
4291	>	* null if none.
4292	>	*
4293	>	* @param transformer a function returning the transformation
4294	>	* for an element, or null if there is no transformation (in
4295	>	* which case it is not combined)
4296	>	* @param reducer a commutative associative combining function
4297	>	* @return the result of accumulating the given transformation
4298	>	* of all keys
4299	>	*/
4300	>	public <U> U reduceKeysInParallel
4301	>	(Function<? super K, ? extends U> transformer,
4302	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4303	>	return ForkJoinTasks.reduceKeys
4304	>	(this, transformer, reducer).invoke();
4305	>	}
4306	>
4307	>	/**
4308	>	* Returns the result of accumulating the given transformation
4309	>	* of all keys using the given reducer to combine values, and
4310	>	* the given basis as an identity value.
4311	>	*
4312	>	* @param transformer a function returning the transformation
4313	>	* for an element
4314	>	* @param basis the identity (initial default value) for the reduction
4315	>	* @param reducer a commutative associative combining function
4316	>	* @return the result of accumulating the given transformation
4317	>	* of all keys
4318	>	*/
4319	>	public double reduceKeysToDoubleInParallel
4320	>	(ToDoubleFunction<? super K> transformer,
4321	>	double basis,
4322	>	DoubleBinaryOperator reducer) {
4323	>	return ForkJoinTasks.reduceKeysToDouble
4324	>	(this, transformer, basis, reducer).invoke();
4325	>	}
4326	>
4327	>	/**
4328	>	* Returns the result of accumulating the given transformation
4329	>	* of all keys using the given reducer to combine values, and
4330	>	* the given basis as an identity value.
4331	>	*
4332	>	* @param transformer a function returning the transformation
4333	>	* for an element
4334	>	* @param basis the identity (initial default value) for the reduction
4335	>	* @param reducer a commutative associative combining function
4336	>	* @return the result of accumulating the given transformation
4337	>	* of all keys
4338	>	*/
4339	>	public long reduceKeysToLongInParallel
4340	>	(ToLongFunction<? super K> transformer,
4341	>	long basis,
4342	>	LongBinaryOperator reducer) {
4343	>	return ForkJoinTasks.reduceKeysToLong
4344	>	(this, transformer, basis, reducer).invoke();
4345	>	}
4346	>
4347	>	/**
4348	>	* Returns the result of accumulating the given transformation
4349	>	* of all keys using the given reducer to combine values, and
4350	>	* the given basis as an identity value.
4351	>	*
4352	>	* @param transformer a function returning the transformation
4353	>	* for an element
4354	>	* @param basis the identity (initial default value) for the reduction
4355	>	* @param reducer a commutative associative combining function
4356	>	* @return the result of accumulating the given transformation
4357	>	* of all keys
4358	>	*/
4359	>	public int reduceKeysToIntInParallel
4360	>	(ToIntFunction<? super K> transformer,
4361	>	int basis,
4362	>	IntBinaryOperator reducer) {
4363	>	return ForkJoinTasks.reduceKeysToInt
4364	>	(this, transformer, basis, reducer).invoke();
4365	>	}
4366	>
4367	>	/**
4368	>	* Performs the given action for each value.
4369	>	*
4370	>	* @param action the action
4371	>	*/
4372	>	public void forEachValueInParallel(Consumer<? super V> action) {
4373	>	ForkJoinTasks.forEachValue
4374	>	(this, action).invoke();
4375	>	}
4376	>
4377	>	/**
4378	>	* Performs the given action for each non-null transformation
4379	>	* of each value.
4380	>	*
4381	>	* @param transformer a function returning the transformation
4382	>	* for an element, or null if there is no transformation (in
4383	>	* which case the action is not applied)
4384	>	* @param action the action
4385	>	*/
4386	>	public <U> void forEachValueInParallel
4387	>	(Function<? super V, ? extends U> transformer,
4388	>	Consumer<? super U> action) {
4389	>	ForkJoinTasks.forEachValue
4390	>	(this, transformer, action).invoke();
4391	>	}
4392	>
4393	>	/**
4394	>	* Returns a non-null result from applying the given search
4395	>	* function on each value, or null if none.  Upon success,
4396	>	* further element processing is suppressed and the results of
4397	>	* any other parallel invocations of the search function are
4398	>	* ignored.
4399	>	*
4400	>	* @param searchFunction a function returning a non-null
4401	>	* result on success, else null
4402	>	* @return a non-null result from applying the given search
4403	>	* function on each value, or null if none
4404	>	*/
4405	>	public <U> U searchValuesInParallel
4406	>	(Function<? super V, ? extends U> searchFunction) {
4407	>	return ForkJoinTasks.searchValues
4408	>	(this, searchFunction).invoke();
4409	>	}
4410	>
4411	>	/**
4412	>	* Returns the result of accumulating all values using the
4413	>	* given reducer to combine values, or null if none.
4414	>	*
4415	>	* @param reducer a commutative associative combining function
4416	>	* @return the result of accumulating all values
4417	>	*/
4418	>	public V reduceValuesInParallel
4419	>	(BiFunction<? super V, ? super V, ? extends V> reducer) {
4420	>	return ForkJoinTasks.reduceValues
4421	>	(this, reducer).invoke();
4422	>	}
4423	>
4424	>	/**
4425	>	* Returns the result of accumulating the given transformation
4426	>	* of all values using the given reducer to combine values, or
4427	>	* null if none.
4428	>	*
4429	>	* @param transformer a function returning the transformation
4430	>	* for an element, or null if there is no transformation (in
4431	>	* which case it is not combined)
4432	>	* @param reducer a commutative associative combining function
4433	>	* @return the result of accumulating the given transformation
4434	>	* of all values
4435	>	*/
4436	>	public <U> U reduceValuesInParallel
4437	>	(Function<? super V, ? extends U> transformer,
4438	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4439	>	return ForkJoinTasks.reduceValues
4440	>	(this, transformer, reducer).invoke();
4441	>	}
4442	>
4443	>	/**
4444	>	* Returns the result of accumulating the given transformation
4445	>	* of all values using the given reducer to combine values,
4446	>	* and the given basis as an identity value.
4447	>	*
4448	>	* @param transformer a function returning the transformation
4449	>	* for an element
4450	>	* @param basis the identity (initial default value) for the reduction
4451	>	* @param reducer a commutative associative combining function
4452	>	* @return the result of accumulating the given transformation
4453	>	* of all values
4454	>	*/
4455	>	public double reduceValuesToDoubleInParallel
4456	>	(ToDoubleFunction<? super V> transformer,
4457	>	double basis,
4458	>	DoubleBinaryOperator reducer) {
4459	>	return ForkJoinTasks.reduceValuesToDouble
4460	>	(this, transformer, basis, reducer).invoke();
4461	>	}
4462	>
4463	>	/**
4464	>	* Returns the result of accumulating the given transformation
4465	>	* of all values using the given reducer to combine values,
4466	>	* and the given basis as an identity value.
4467	>	*
4468	>	* @param transformer a function returning the transformation
4469	>	* for an element
4470	>	* @param basis the identity (initial default value) for the reduction
4471	>	* @param reducer a commutative associative combining function
4472	>	* @return the result of accumulating the given transformation
4473	>	* of all values
4474	>	*/
4475	>	public long reduceValuesToLongInParallel
4476	>	(ToLongFunction<? super V> transformer,
4477	>	long basis,
4478	>	LongBinaryOperator reducer) {
4479	>	return ForkJoinTasks.reduceValuesToLong
4480	>	(this, transformer, basis, reducer).invoke();
4481	>	}
4482	>
4483	>	/**
4484	>	* Returns the result of accumulating the given transformation
4485	>	* of all values using the given reducer to combine values,
4486	>	* and the given basis as an identity value.
4487	>	*
4488	>	* @param transformer a function returning the transformation
4489	>	* for an element
4490	>	* @param basis the identity (initial default value) for the reduction
4491	>	* @param reducer a commutative associative combining function
4492	>	* @return the result of accumulating the given transformation
4493	>	* of all values
4494	>	*/
4495	>	public int reduceValuesToIntInParallel
4496	>	(ToIntFunction<? super V> transformer,
4497	>	int basis,
4498	>	IntBinaryOperator reducer) {
4499	>	return ForkJoinTasks.reduceValuesToInt
4500	>	(this, transformer, basis, reducer).invoke();
4501	>	}
4502	>
4503	>	/**
4504	>	* Performs the given action for each entry.
4505	>	*
4506	>	* @param action the action
4507	>	*/
4508	>	public void forEachEntryInParallel(Consumer<? super Map.Entry<K,V>> action) {
4509	>	ForkJoinTasks.forEachEntry
4510	>	(this, action).invoke();
4511	>	}
4512	>
4513	>	/**
4514	>	* Performs the given action for each non-null transformation
4515	>	* of each entry.
4516	>	*
4517	>	* @param transformer a function returning the transformation
4518	>	* for an element, or null if there is no transformation (in
4519	>	* which case the action is not applied)
4520	>	* @param action the action
4521	>	*/
4522	>	public <U> void forEachEntryInParallel
4523	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4524	>	Consumer<? super U> action) {
4525	>	ForkJoinTasks.forEachEntry
4526	>	(this, transformer, action).invoke();
4527	>	}
4528	>
4529	>	/**
4530	>	* Returns a non-null result from applying the given search
4531	>	* function on each entry, or null if none.  Upon success,
4532	>	* further element processing is suppressed and the results of
4533	>	* any other parallel invocations of the search function are
4534	>	* ignored.
4535	>	*
4536	>	* @param searchFunction a function returning a non-null
4537	>	* result on success, else null
4538	>	* @return a non-null result from applying the given search
4539	>	* function on each entry, or null if none
4540	>	*/
4541	>	public <U> U searchEntriesInParallel
4542	>	(Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4543	>	return ForkJoinTasks.searchEntries
4544	>	(this, searchFunction).invoke();
4545	>	}
4546	>
4547	>	/**
4548	>	* Returns the result of accumulating all entries using the
4549	>	* given reducer to combine values, or null if none.
4550	>	*
4551	>	* @param reducer a commutative associative combining function
4552	>	* @return the result of accumulating all entries
4553	>	*/
4554	>	public Map.Entry<K,V> reduceEntriesInParallel
4555	>	(BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4556	>	return ForkJoinTasks.reduceEntries
4557	>	(this, reducer).invoke();
4558	>	}
4559	>
4560	>	/**
4561	>	* Returns the result of accumulating the given transformation
4562	>	* of all entries using the given reducer to combine values,
4563	>	* or null if none.
4564	>	*
4565	>	* @param transformer a function returning the transformation
4566	>	* for an element, or null if there is no transformation (in
4567	>	* which case it is not combined)
4568	>	* @param reducer a commutative associative combining function
4569	>	* @return the result of accumulating the given transformation
4570	>	* of all entries
4571	>	*/
4572	>	public <U> U reduceEntriesInParallel
4573	>	(Function<Map.Entry<K,V>, ? extends U> transformer,
4574	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4575	>	return ForkJoinTasks.reduceEntries
4576	>	(this, transformer, reducer).invoke();
4577	>	}
4578	>
4579	>	/**
4580	>	* Returns the result of accumulating the given transformation
4581	>	* of all entries using the given reducer to combine values,
4582	>	* and the given basis as an identity value.
4583	>	*
4584	>	* @param transformer a function returning the transformation
4585	>	* for an element
4586	>	* @param basis the identity (initial default value) for the reduction
4587	>	* @param reducer a commutative associative combining function
4588	>	* @return the result of accumulating the given transformation
4589	>	* of all entries
4590	>	*/
4591	>	public double reduceEntriesToDoubleInParallel
4592	>	(ToDoubleFunction<Map.Entry<K,V>> transformer,
4593	>	double basis,
4594	>	DoubleBinaryOperator reducer) {
4595	>	return ForkJoinTasks.reduceEntriesToDouble
4596	>	(this, transformer, basis, reducer).invoke();
4597	>	}
4598	>
4599	>	/**
4600	>	* Returns the result of accumulating the given transformation
4601	>	* of all entries using the given reducer to combine values,
4602	>	* and the given basis as an identity value.
4603	>	*
4604	>	* @param transformer a function returning the transformation
4605	>	* for an element
4606	>	* @param basis the identity (initial default value) for the reduction
4607	>	* @param reducer a commutative associative combining function
4608	>	* @return the result of accumulating the given transformation
4609	>	* of all entries
4610	>	*/
4611	>	public long reduceEntriesToLongInParallel
4612	>	(ToLongFunction<Map.Entry<K,V>> transformer,
4613	>	long basis,
4614	>	LongBinaryOperator reducer) {
4615	>	return ForkJoinTasks.reduceEntriesToLong
4616	>	(this, transformer, basis, reducer).invoke();
4617	>	}
4618	>
4619	>	/**
4620	>	* Returns the result of accumulating the given transformation
4621	>	* of all entries using the given reducer to combine values,
4622	>	* and the given basis as an identity value.
4623	>	*
4624	>	* @param transformer a function returning the transformation
4625	>	* for an element
4626	>	* @param basis the identity (initial default value) for the reduction
4627	>	* @param reducer a commutative associative combining function
4628	>	* @return the result of accumulating the given transformation
4629	>	* of all entries
4630	>	*/
4631	>	public int reduceEntriesToIntInParallel
4632	>	(ToIntFunction<Map.Entry<K,V>> transformer,
4633	>	int basis,
4634	>	IntBinaryOperator reducer) {
4635	>	return ForkJoinTasks.reduceEntriesToInt
4636	>	(this, transformer, basis, reducer).invoke();
4637	>	}
4638	>
4639	>
4640	>	/* ----------------Views -------------- */
4641	>
4642	>	/**
4643	>	* Base class for views.
4644	>	*/
4645	>	abstract static class CHMCollectionView<K,V,E>
4646	>	implements Collection<E>, java.io.Serializable {
4647	>	private static final long serialVersionUID = 7249069246763182397L;
4648	>	final ConcurrentHashMap<K,V> map;
4649	>	CHMCollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4650	>
4651	>	/**
4652	>	* Returns the map backing this view.
4653	>	*
4654	>	* @return the map backing this view
4655	>	*/
4656	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4657	>
4658	>	/**
4659	>	* Removes all of the elements from this view, by removing all
4660	>	* the mappings from the map backing this view.
4661	>	*/
4662	>	public final void clear()      { map.clear(); }
4663	>	public final int size()        { return map.size(); }
4664	>	public final boolean isEmpty() { return map.isEmpty(); }
4665	>
4666	>	// implementations below rely on concrete classes supplying these
4667	>	// abstract methods
4668	>	/**
4669	>	* Returns a "weakly consistent" iterator that will never
4670	>	* throw {@link ConcurrentModificationException}, and
4671	>	* guarantees to traverse elements as they existed upon
4672	>	* construction of the iterator, and may (but is not
4673	>	* guaranteed to) reflect any modifications subsequent to
4674	>	* construction.
4675	>	*/
4676	>	public abstract Iterator<E> iterator();
4677	>	public abstract boolean contains(Object o);
4678	>	public abstract boolean remove(Object o);
4679	>
4680	>	private static final String oomeMsg = "Required array size too large";
4681	>
4682	>	public final Object[] toArray() {
4683	>	long sz = map.mappingCount();
4684	>	if (sz > MAX_ARRAY_SIZE)
4685	>	throw new OutOfMemoryError(oomeMsg);
4686	>	int n = (int)sz;
4687	>	Object[] r = new Object[n];
4688	>	int i = 0;
4689	>	for (E e : this) {
4690	>	if (i == n) {
4691	>	if (n >= MAX_ARRAY_SIZE)
4692	>	throw new OutOfMemoryError(oomeMsg);
4693	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4694	>	n = MAX_ARRAY_SIZE;
4695	>	else
4696	>	n += (n >>> 1) + 1;
4697	>	r = Arrays.copyOf(r, n);
4698	>	}
4699	>	r[i++] = e;
4700	>	}
4701	>	return (i == n) ? r : Arrays.copyOf(r, i);
4702	>	}
4703	>
4704	>	@SuppressWarnings("unchecked")
4705	>	public final <T> T[] toArray(T[] a) {
4706	>	long sz = map.mappingCount();
4707	>	if (sz > MAX_ARRAY_SIZE)
4708	>	throw new OutOfMemoryError(oomeMsg);
4709	>	int m = (int)sz;
4710	>	T[] r = (a.length >= m) ? a :
4711	>	(T[])java.lang.reflect.Array
4712	>	.newInstance(a.getClass().getComponentType(), m);
4713	>	int n = r.length;
4714	>	int i = 0;
4715	>	for (E e : this) {
4716	>	if (i == n) {
4717	>	if (n >= MAX_ARRAY_SIZE)
4718	>	throw new OutOfMemoryError(oomeMsg);
4719	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4720	>	n = MAX_ARRAY_SIZE;
4721	>	else
4722	>	n += (n >>> 1) + 1;
4723	>	r = Arrays.copyOf(r, n);
4724	>	}
4725	>	r[i++] = (T)e;
4726	>	}
4727	>	if (a == r && i < n) {
4728	>	r[i] = null; // null-terminate
4729	>	return r;
4730	>	}
4731	>	return (i == n) ? r : Arrays.copyOf(r, i);
4732	>	}
4733	>
4734	>	/**
4735	>	* Returns a string representation of this collection.
4736	>	* The string representation consists of the string representations
4737	>	* of the collection's elements in the order they are returned by
4738	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4739	>	* Adjacent elements are separated by the characters {@code ", "}
4740	>	* (comma and space).  Elements are converted to strings as by
4741	>	* {@link String#valueOf(Object)}.
4742	>	*
4743	>	* @return a string representation of this collection
4744	>	*/
4745	>	public final String toString() {
4746	>	StringBuilder sb = new StringBuilder();
4747	>	sb.append('[');
4748	>	Iterator<E> it = iterator();
4749	>	if (it.hasNext()) {
4750	>	for (;;) {
4751	>	Object e = it.next();
4752	>	sb.append(e == this ? "(this Collection)" : e);
4753	>	if (!it.hasNext())
4754	>	break;
4755	>	sb.append(',').append(' ');
4756	>	}
4757	>	}
4758	>	return sb.append(']').toString();
4759	>	}
4760	>
4761	>	public final boolean containsAll(Collection<?> c) {
4762	>	if (c != this) {
4763	>	for (Object e : c) {
4764	>	if (e == null || !contains(e))
4765	>	return false;
4766	>	}
4767	>	}
4768	>	return true;
4769	>	}
4770	>
4771	>	public final boolean removeAll(Collection<?> c) {
4772	>	boolean modified = false;
4773	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4774	>	if (c.contains(it.next())) {
4775	>	it.remove();
4776	>	modified = true;
4777	>	}
4778	>	}
4779	>	return modified;
4780	>	}
4781	>
4782	>	public final boolean retainAll(Collection<?> c) {
4783	>	boolean modified = false;
4784	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4785	>	if (!c.contains(it.next())) {
4786	>	it.remove();
4787	>	modified = true;
4788	>	}
4789	>	}
4790	>	return modified;
4791	>	}
4792	>
4793	>	}
4794	>
4795	>	abstract static class CHMSetView<K,V,E>
4796	>	extends CHMCollectionView<K,V,E>
4797	>	implements Set<E>, java.io.Serializable {
4798	>	private static final long serialVersionUID = 7249069246763182397L;
4799	>	CHMSetView(ConcurrentHashMap<K,V> map) { super(map); }
4800	>
4801	>	// Implement Set API
4802	>
4803	>	/**
4804	>	* Implements {@link Set#hashCode()}.
4805	>	* @return the hash code value for this set
4806	>	*/
4807	>	public final int hashCode() {
4808	>	int h = 0;
4809	>	for (E e : this)
4810	>	h += e.hashCode();
4811	>	return h;
4812	>	}
4813	>
4814	>	/**
4815	>	* Implements {@link Set#equals(Object)}.
4816	>	* @param o object to be compared for equality with this set
4817	>	* @return {@code true} if the specified object is equal to this set
4818	>	*/
4819	>	public final boolean equals(Object o) {
4820	>	Set<?> c;
4821	>	return ((o instanceof Set) &&
4822	>	((c = (Set<?>)o) == this ||
4823	>	(containsAll(c) && c.containsAll(this))));
4824	>	}
4825	>	}
4826	>
4827	>	/**
4828	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4829	>	* which additions may optionally be enabled by mapping to a
4830	>	* common value.  This class cannot be directly instantiated.
4831	>	* See {@link #keySet() keySet()},
4832	>	* {@link #keySet(Object) keySet(V)},
4833	>	* {@link #newKeySet() newKeySet()},
4834	>	* {@link #newKeySet(int) newKeySet(int)}.
4835	>	*/
4836	>	public static class KeySetView<K,V>
4837	>	extends CHMSetView<K,V,K>
4838	>	implements Set<K>, java.io.Serializable {
4839	>	private static final long serialVersionUID = 7249069246763182397L;
4840	>	private final V value;
4841	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4842	>	super(map);
4843	>	this.value = value;
4844	>	}
4845	>
4846	>	/**
4847	>	* Returns the default mapped value for additions,
4848	>	* or {@code null} if additions are not supported.
4849	>	*
4850	>	* @return the default mapped value for additions, or {@code null}
4851	>	* if not supported
4852	>	*/
4853	>	public V getMappedValue() { return value; }
4854	>
4855	>	/**
4856	>	* {@inheritDoc}
4857	>	* @throws NullPointerException if the specified key is null
4858	>	*/
4859	>	public boolean contains(Object o) { return map.containsKey(o); }
4860	>
4861	>	/**
4862	>	* Removes the key from this map view, by removing the key (and its
4863	>	* corresponding value) from the backing map.  This method does
4864	>	* nothing if the key is not in the map.
4865	>	*
4866	>	* @param  o the key to be removed from the backing map
4867	>	* @return {@code true} if the backing map contained the specified key
4868	>	* @throws NullPointerException if the specified key is null
4869	>	*/
4870	>	public boolean remove(Object o) { return map.remove(o) != null; }
4871	>
4872	>	/**
4873	>	* @return an iterator over the keys of the backing map
4874	>	*/
4875	>	public Iterator<K> iterator() { return new KeyIterator<K,V>(map); }
4876	>
4877	>	/**
4878	>	* Adds the specified key to this set view by mapping the key to
4879	>	* the default mapped value in the backing map, if defined.
4880	>	*
4881	>	* @param e key to be added
4882	>	* @return {@code true} if this set changed as a result of the call
4883	>	* @throws NullPointerException if the specified key is null
4884	>	* @throws UnsupportedOperationException if no default mapped value
4885	>	* for additions was provided
4886	>	*/
4887	>	public boolean add(K e) {
4888	>	V v;
4889	>	if ((v = value) == null)
4890	>	throw new UnsupportedOperationException();
4891	>	return map.internalPut(e, v, true) == null;
4892	>	}
4893	>
4894	>	/**
4895	>	* Adds all of the elements in the specified collection to this set,
4896	>	* as if by calling {@link #add} on each one.
4897	>	*
4898	>	* @param c the elements to be inserted into this set
4899	>	* @return {@code true} if this set changed as a result of the call
4900	>	* @throws NullPointerException if the collection or any of its
4901	>	* elements are {@code null}
4902	>	* @throws UnsupportedOperationException if no default mapped value
4903	>	* for additions was provided
4904	>	*/
4905	>	public boolean addAll(Collection<? extends K> c) {
4906	>	boolean added = false;
4907	>	V v;
4908	>	if ((v = value) == null)
4909	>	throw new UnsupportedOperationException();
4910	>	for (K e : c) {
4911	>	if (map.internalPut(e, v, true) == null)
4912	>	added = true;
4913	>	}
4914	>	return added;
4915	>	}
4916	>
4917	>	public Spliterator<K> spliterator() {
4918	>	return new KeyIterator<>(map, null);
4919	>	}
4920	>
4921	>	}
4922	>
4923	>	/**
4924	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4925	>	* values, in which additions are disabled. This class cannot be
4926	>	* directly instantiated. See {@link #values()}.
4927	>	*
4928	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
4929	>	* that will never throw {@link ConcurrentModificationException},
4930	>	* and guarantees to traverse elements as they existed upon
4931	>	* construction of the iterator, and may (but is not guaranteed to)
4932	>	* reflect any modifications subsequent to construction.
4933	>	*/
4934	>	public static final class ValuesView<K,V>
4935	>	extends CHMCollectionView<K,V,V>
4936	>	implements Collection<V>, java.io.Serializable {
4937	>	private static final long serialVersionUID = 2249069246763182397L;
4938	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4939	>	public final boolean contains(Object o) {
4940	>	return map.containsValue(o);
4941	>	}
4942	>	public final boolean remove(Object o) {
4943	>	if (o != null) {
4944	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4945	>	if (o.equals(it.next())) {
4946	>	it.remove();
4947	>	return true;
4948		}
4949		}
1420	–	} finally {
1421	–	seg.unlock();
4950		}
4951	+	return false;
4952		}
4953	<	s.writeObject(null);
4954	<	s.writeObject(null);
4953	>
4954	>	/**
4955	>	* @return an iterator over the values of the backing map
4956	>	*/
4957	>	public final Iterator<V> iterator() {
4958	>	return new ValueIterator<K,V>(map);
4959	>	}
4960	>
4961	>	/** Always throws {@link UnsupportedOperationException}. */
4962	>	public final boolean add(V e) {
4963	>	throw new UnsupportedOperationException();
4964	>	}
4965	>	/** Always throws {@link UnsupportedOperationException}. */
4966	>	public final boolean addAll(Collection<? extends V> c) {
4967	>	throw new UnsupportedOperationException();
4968	>	}
4969	>
4970	>	public Spliterator<V> spliterator() {
4971	>	return new ValueIterator<K,V>(map, null);
4972	>	}
4973	>
4974		}
4975
4976		/**
4977	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4978	<	* stream (i.e., deserializes it).
4979	<	* @param s the stream
4977	>	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4978	>	* entries.  This class cannot be directly instantiated. See
4979	>	* {@link #entrySet()}.
4980		*/
4981	<	@SuppressWarnings("unchecked")
4982	<	private void readObject(java.io.ObjectInputStream s)
4983	<	throws java.io.IOException, ClassNotFoundException {
4984	<	s.defaultReadObject();
4981	>	public static final class EntrySetView<K,V>
4982	>	extends CHMSetView<K,V,Map.Entry<K,V>>
4983	>	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4984	>	private static final long serialVersionUID = 2249069246763182397L;
4985	>	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4986	>
4987	>	public final boolean contains(Object o) {
4988	>	Object k, v, r; Map.Entry<?,?> e;
4989	>	return ((o instanceof Map.Entry) &&
4990	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4991	>	(r = map.get(k)) != null &&
4992	>	(v = e.getValue()) != null &&
4993	>	(v == r || v.equals(r)));
4994	>	}
4995	>	public final boolean remove(Object o) {
4996	>	Object k, v; Map.Entry<?,?> e;
4997	>	return ((o instanceof Map.Entry) &&
4998	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4999	>	(v = e.getValue()) != null &&
5000	>	map.remove(k, v));
5001	>	}
5002	>
5003	>	/**
5004	>	* @return an iterator over the entries of the backing map
5005	>	*/
5006	>	public final Iterator<Map.Entry<K,V>> iterator() {
5007	>	return new EntryIterator<K,V>(map);
5008	>	}
5009	>
5010	>	/**
5011	>	* Adds the specified mapping to this view.
5012	>	*
5013	>	* @param e mapping to be added
5014	>	* @return {@code true} if this set changed as a result of the call
5015	>	* @throws NullPointerException if the entry, its key, or its
5016	>	* value is null
5017	>	*/
5018	>	public final boolean add(Entry<K,V> e) {
5019	>	return map.internalPut(e.getKey(), e.getValue(), false) == null;
5020	>	}
5021
5022	<	// Re-initialize segments to be minimally sized, and let grow.
5023	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
5024	<	final Segment<K,V>[] segments = this.segments;
5025	<	for (int k = 0; k < segments.length; ++k) {
5026	<	Segment<K,V> seg = segments[k];
5027	<	if (seg != null) {
5028	<	seg.threshold = (int)(cap * seg.loadFactor);
5029	<	seg.table = (HashEntry<K,V>[]) new HashEntry<?,?>[cap];
5022	>	/**
5023	>	* Adds all of the mappings in the specified collection to this
5024	>	* set, as if by calling {@link #add(Map.Entry)} on each one.
5025	>	* @param c the mappings to be inserted into this set
5026	>	* @return {@code true} if this set changed as a result of the call
5027	>	* @throws NullPointerException if the collection or any of its
5028	>	* entries, keys, or values are null
5029	>	*/
5030	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
5031	>	boolean added = false;
5032	>	for (Entry<K,V> e : c) {
5033	>	if (add(e))
5034	>	added = true;
5035		}
5036	+	return added;
5037		}
5038
5039	<	// Read the keys and values, and put the mappings in the table
5040	<	for (;;) {
5041	<	K key = (K) s.readObject();
5042	<	V value = (V) s.readObject();
5043	<	if (key == null)
5044	<	break;
5045	<	put(key, value);
5039	>	public Spliterator<Map.Entry<K,V>> spliterator() {
5040	>	return new EntryIterator<K,V>(map, null);
5041	>	}
5042	>
5043	>	}
5044	>
5045	>	// ---------------------------------------------------------------------
5046	>
5047	>	/**
5048	>	* Predefined tasks for performing bulk parallel operations on
5049	>	* ConcurrentHashMaps. These tasks follow the forms and rules used
5050	>	* for bulk operations. Each method has the same name, but returns
5051	>	* a task rather than invoking it. These methods may be useful in
5052	>	* custom applications such as submitting a task without waiting
5053	>	* for completion, using a custom pool, or combining with other
5054	>	* tasks.
5055	>	*/
5056	>	public static class ForkJoinTasks {
5057	>	private ForkJoinTasks() {}
5058	>
5059	>	/**
5060	>	* Returns a task that when invoked, performs the given
5061	>	* action for each (key, value)
5062	>	*
5063	>	* @param map the map
5064	>	* @param action the action
5065	>	* @return the task
5066	>	*/
5067	>	public static <K,V> ForkJoinTask<Void> forEach
5068	>	(ConcurrentHashMap<K,V> map,
5069	>	BiConsumer<? super K, ? super V> action) {
5070	>	if (action == null) throw new NullPointerException();
5071	>	return new ForEachMappingTask<K,V>(map, null, -1, action);
5072	>	}
5073	>
5074	>	/**
5075	>	* Returns a task that when invoked, performs the given
5076	>	* action for each non-null transformation of each (key, value)
5077	>	*
5078	>	* @param map the map
5079	>	* @param transformer a function returning the transformation
5080	>	* for an element, or null if there is no transformation (in
5081	>	* which case the action is not applied)
5082	>	* @param action the action
5083	>	* @return the task
5084	>	*/
5085	>	public static <K,V,U> ForkJoinTask<Void> forEach
5086	>	(ConcurrentHashMap<K,V> map,
5087	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5088	>	Consumer<? super U> action) {
5089	>	if (transformer == null || action == null)
5090	>	throw new NullPointerException();
5091	>	return new ForEachTransformedMappingTask<K,V,U>
5092	>	(map, null, -1, transformer, action);
5093	>	}
5094	>
5095	>	/**
5096	>	* Returns a task that when invoked, returns a non-null result
5097	>	* from applying the given search function on each (key,
5098	>	* value), or null if none. Upon success, further element
5099	>	* processing is suppressed and the results of any other
5100	>	* parallel invocations of the search function are ignored.
5101	>	*
5102	>	* @param map the map
5103	>	* @param searchFunction a function returning a non-null
5104	>	* result on success, else null
5105	>	* @return the task
5106	>	*/
5107	>	public static <K,V,U> ForkJoinTask<U> search
5108	>	(ConcurrentHashMap<K,V> map,
5109	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
5110	>	if (searchFunction == null) throw new NullPointerException();
5111	>	return new SearchMappingsTask<K,V,U>
5112	>	(map, null, -1, searchFunction,
5113	>	new AtomicReference<U>());
5114	>	}
5115	>
5116	>	/**
5117	>	* Returns a task that when invoked, returns the result of
5118	>	* accumulating the given transformation of all (key, value) pairs
5119	>	* using the given reducer to combine values, or null if none.
5120	>	*
5121	>	* @param map the map
5122	>	* @param transformer a function returning the transformation
5123	>	* for an element, or null if there is no transformation (in
5124	>	* which case it is not combined)
5125	>	* @param reducer a commutative associative combining function
5126	>	* @return the task
5127	>	*/
5128	>	public static <K,V,U> ForkJoinTask<U> reduce
5129	>	(ConcurrentHashMap<K,V> map,
5130	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5131	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5132	>	if (transformer == null || reducer == null)
5133	>	throw new NullPointerException();
5134	>	return new MapReduceMappingsTask<K,V,U>
5135	>	(map, null, -1, null, transformer, reducer);
5136	>	}
5137	>
5138	>	/**
5139	>	* Returns a task that when invoked, returns the result of
5140	>	* accumulating the given transformation of all (key, value) pairs
5141	>	* using the given reducer to combine values, and the given
5142	>	* basis as an identity value.
5143	>	*
5144	>	* @param map the map
5145	>	* @param transformer a function returning the transformation
5146	>	* for an element
5147	>	* @param basis the identity (initial default value) for the reduction
5148	>	* @param reducer a commutative associative combining function
5149	>	* @return the task
5150	>	*/
5151	>	public static <K,V> ForkJoinTask<Double> reduceToDouble
5152	>	(ConcurrentHashMap<K,V> map,
5153	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5154	>	double basis,
5155	>	DoubleBinaryOperator reducer) {
5156	>	if (transformer == null || reducer == null)
5157	>	throw new NullPointerException();
5158	>	return new MapReduceMappingsToDoubleTask<K,V>
5159	>	(map, null, -1, null, transformer, basis, reducer);
5160	>	}
5161	>
5162	>	/**
5163	>	* Returns a task that when invoked, returns the result of
5164	>	* accumulating the given transformation of all (key, value) pairs
5165	>	* using the given reducer to combine values, and the given
5166	>	* basis as an identity value.
5167	>	*
5168	>	* @param map the map
5169	>	* @param transformer a function returning the transformation
5170	>	* for an element
5171	>	* @param basis the identity (initial default value) for the reduction
5172	>	* @param reducer a commutative associative combining function
5173	>	* @return the task
5174	>	*/
5175	>	public static <K,V> ForkJoinTask<Long> reduceToLong
5176	>	(ConcurrentHashMap<K,V> map,
5177	>	ToLongBiFunction<? super K, ? super V> transformer,
5178	>	long basis,
5179	>	LongBinaryOperator reducer) {
5180	>	if (transformer == null || reducer == null)
5181	>	throw new NullPointerException();
5182	>	return new MapReduceMappingsToLongTask<K,V>
5183	>	(map, null, -1, null, transformer, basis, reducer);
5184	>	}
5185	>
5186	>	/**
5187	>	* Returns a task that when invoked, returns the result of
5188	>	* accumulating the given transformation of all (key, value) pairs
5189	>	* using the given reducer to combine values, and the given
5190	>	* basis as an identity value.
5191	>	*
5192	>	* @param map the map
5193	>	* @param transformer a function returning the transformation
5194	>	* for an element
5195	>	* @param basis the identity (initial default value) for the reduction
5196	>	* @param reducer a commutative associative combining function
5197	>	* @return the task
5198	>	*/
5199	>	public static <K,V> ForkJoinTask<Integer> reduceToInt
5200	>	(ConcurrentHashMap<K,V> map,
5201	>	ToIntBiFunction<? super K, ? super V> transformer,
5202	>	int basis,
5203	>	IntBinaryOperator reducer) {
5204	>	if (transformer == null || reducer == null)
5205	>	throw new NullPointerException();
5206	>	return new MapReduceMappingsToIntTask<K,V>
5207	>	(map, null, -1, null, transformer, basis, reducer);
5208	>	}
5209	>
5210	>	/**
5211	>	* Returns a task that when invoked, performs the given action
5212	>	* for each key.
5213	>	*
5214	>	* @param map the map
5215	>	* @param action the action
5216	>	* @return the task
5217	>	*/
5218	>	public static <K,V> ForkJoinTask<Void> forEachKey
5219	>	(ConcurrentHashMap<K,V> map,
5220	>	Consumer<? super K> action) {
5221	>	if (action == null) throw new NullPointerException();
5222	>	return new ForEachKeyTask<K,V>(map, null, -1, action);
5223	>	}
5224	>
5225	>	/**
5226	>	* Returns a task that when invoked, performs the given action
5227	>	* for each non-null transformation of each key.
5228	>	*
5229	>	* @param map the map
5230	>	* @param transformer a function returning the transformation
5231	>	* for an element, or null if there is no transformation (in
5232	>	* which case the action is not applied)
5233	>	* @param action the action
5234	>	* @return the task
5235	>	*/
5236	>	public static <K,V,U> ForkJoinTask<Void> forEachKey
5237	>	(ConcurrentHashMap<K,V> map,
5238	>	Function<? super K, ? extends U> transformer,
5239	>	Consumer<? super U> action) {
5240	>	if (transformer == null || action == null)
5241	>	throw new NullPointerException();
5242	>	return new ForEachTransformedKeyTask<K,V,U>
5243	>	(map, null, -1, transformer, action);
5244	>	}
5245	>
5246	>	/**
5247	>	* Returns a task that when invoked, returns a non-null result
5248	>	* from applying the given search function on each key, or
5249	>	* null if none.  Upon success, further element processing is
5250	>	* suppressed and the results of any other parallel
5251	>	* invocations of the search function are ignored.
5252	>	*
5253	>	* @param map the map
5254	>	* @param searchFunction a function returning a non-null
5255	>	* result on success, else null
5256	>	* @return the task
5257	>	*/
5258	>	public static <K,V,U> ForkJoinTask<U> searchKeys
5259	>	(ConcurrentHashMap<K,V> map,
5260	>	Function<? super K, ? extends U> searchFunction) {
5261	>	if (searchFunction == null) throw new NullPointerException();
5262	>	return new SearchKeysTask<K,V,U>
5263	>	(map, null, -1, searchFunction,
5264	>	new AtomicReference<U>());
5265	>	}
5266	>
5267	>	/**
5268	>	* Returns a task that when invoked, returns the result of
5269	>	* accumulating all keys using the given reducer to combine
5270	>	* values, or null if none.
5271	>	*
5272	>	* @param map the map
5273	>	* @param reducer a commutative associative combining function
5274	>	* @return the task
5275	>	*/
5276	>	public static <K,V> ForkJoinTask<K> reduceKeys
5277	>	(ConcurrentHashMap<K,V> map,
5278	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5279	>	if (reducer == null) throw new NullPointerException();
5280	>	return new ReduceKeysTask<K,V>
5281	>	(map, null, -1, null, reducer);
5282	>	}
5283	>
5284	>	/**
5285	>	* Returns a task that when invoked, returns the result of
5286	>	* accumulating the given transformation of all keys using the given
5287	>	* reducer to combine values, or null if none.
5288	>	*
5289	>	* @param map the map
5290	>	* @param transformer a function returning the transformation
5291	>	* for an element, or null if there is no transformation (in
5292	>	* which case it is not combined)
5293	>	* @param reducer a commutative associative combining function
5294	>	* @return the task
5295	>	*/
5296	>	public static <K,V,U> ForkJoinTask<U> reduceKeys
5297	>	(ConcurrentHashMap<K,V> map,
5298	>	Function<? super K, ? extends U> transformer,
5299	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5300	>	if (transformer == null || reducer == null)
5301	>	throw new NullPointerException();
5302	>	return new MapReduceKeysTask<K,V,U>
5303	>	(map, null, -1, null, transformer, reducer);
5304	>	}
5305	>
5306	>	/**
5307	>	* Returns a task that when invoked, returns the result of
5308	>	* accumulating the given transformation of all keys using the given
5309	>	* reducer to combine values, and the given basis as an
5310	>	* identity value.
5311	>	*
5312	>	* @param map the map
5313	>	* @param transformer a function returning the transformation
5314	>	* for an element
5315	>	* @param basis the identity (initial default value) for the reduction
5316	>	* @param reducer a commutative associative combining function
5317	>	* @return the task
5318	>	*/
5319	>	public static <K,V> ForkJoinTask<Double> reduceKeysToDouble
5320	>	(ConcurrentHashMap<K,V> map,
5321	>	ToDoubleFunction<? super K> transformer,
5322	>	double basis,
5323	>	DoubleBinaryOperator reducer) {
5324	>	if (transformer == null || reducer == null)
5325	>	throw new NullPointerException();
5326	>	return new MapReduceKeysToDoubleTask<K,V>
5327	>	(map, null, -1, null, transformer, basis, reducer);
5328	>	}
5329	>
5330	>	/**
5331	>	* Returns a task that when invoked, returns the result of
5332	>	* accumulating the given transformation of all keys using the given
5333	>	* reducer to combine values, and the given basis as an
5334	>	* identity value.
5335	>	*
5336	>	* @param map the map
5337	>	* @param transformer a function returning the transformation
5338	>	* for an element
5339	>	* @param basis the identity (initial default value) for the reduction
5340	>	* @param reducer a commutative associative combining function
5341	>	* @return the task
5342	>	*/
5343	>	public static <K,V> ForkJoinTask<Long> reduceKeysToLong
5344	>	(ConcurrentHashMap<K,V> map,
5345	>	ToLongFunction<? super K> transformer,
5346	>	long basis,
5347	>	LongBinaryOperator reducer) {
5348	>	if (transformer == null || reducer == null)
5349	>	throw new NullPointerException();
5350	>	return new MapReduceKeysToLongTask<K,V>
5351	>	(map, null, -1, null, transformer, basis, reducer);
5352	>	}
5353	>
5354	>	/**
5355	>	* Returns a task that when invoked, returns the result of
5356	>	* accumulating the given transformation of all keys using the given
5357	>	* reducer to combine values, and the given basis as an
5358	>	* identity value.
5359	>	*
5360	>	* @param map the map
5361	>	* @param transformer a function returning the transformation
5362	>	* for an element
5363	>	* @param basis the identity (initial default value) for the reduction
5364	>	* @param reducer a commutative associative combining function
5365	>	* @return the task
5366	>	*/
5367	>	public static <K,V> ForkJoinTask<Integer> reduceKeysToInt
5368	>	(ConcurrentHashMap<K,V> map,
5369	>	ToIntFunction<? super K> transformer,
5370	>	int basis,
5371	>	IntBinaryOperator reducer) {
5372	>	if (transformer == null || reducer == null)
5373	>	throw new NullPointerException();
5374	>	return new MapReduceKeysToIntTask<K,V>
5375	>	(map, null, -1, null, transformer, basis, reducer);
5376	>	}
5377	>
5378	>	/**
5379	>	* Returns a task that when invoked, performs the given action
5380	>	* for each value.
5381	>	*
5382	>	* @param map the map
5383	>	* @param action the action
5384	>	* @return the task
5385	>	*/
5386	>	public static <K,V> ForkJoinTask<Void> forEachValue
5387	>	(ConcurrentHashMap<K,V> map,
5388	>	Consumer<? super V> action) {
5389	>	if (action == null) throw new NullPointerException();
5390	>	return new ForEachValueTask<K,V>(map, null, -1, action);
5391	>	}
5392	>
5393	>	/**
5394	>	* Returns a task that when invoked, performs the given action
5395	>	* for each non-null transformation of each value.
5396	>	*
5397	>	* @param map the map
5398	>	* @param transformer a function returning the transformation
5399	>	* for an element, or null if there is no transformation (in
5400	>	* which case the action is not applied)
5401	>	* @param action the action
5402	>	* @return the task
5403	>	*/
5404	>	public static <K,V,U> ForkJoinTask<Void> forEachValue
5405	>	(ConcurrentHashMap<K,V> map,
5406	>	Function<? super V, ? extends U> transformer,
5407	>	Consumer<? super U> action) {
5408	>	if (transformer == null || action == null)
5409	>	throw new NullPointerException();
5410	>	return new ForEachTransformedValueTask<K,V,U>
5411	>	(map, null, -1, transformer, action);
5412	>	}
5413	>
5414	>	/**
5415	>	* Returns a task that when invoked, returns a non-null result
5416	>	* from applying the given search function on each value, or
5417	>	* null if none.  Upon success, further element processing is
5418	>	* suppressed and the results of any other parallel
5419	>	* invocations of the search function are ignored.
5420	>	*
5421	>	* @param map the map
5422	>	* @param searchFunction a function returning a non-null
5423	>	* result on success, else null
5424	>	* @return the task
5425	>	*/
5426	>	public static <K,V,U> ForkJoinTask<U> searchValues
5427	>	(ConcurrentHashMap<K,V> map,
5428	>	Function<? super V, ? extends U> searchFunction) {
5429	>	if (searchFunction == null) throw new NullPointerException();
5430	>	return new SearchValuesTask<K,V,U>
5431	>	(map, null, -1, searchFunction,
5432	>	new AtomicReference<U>());
5433	>	}
5434	>
5435	>	/**
5436	>	* Returns a task that when invoked, returns the result of
5437	>	* accumulating all values using the given reducer to combine
5438	>	* values, or null if none.
5439	>	*
5440	>	* @param map the map
5441	>	* @param reducer a commutative associative combining function
5442	>	* @return the task
5443	>	*/
5444	>	public static <K,V> ForkJoinTask<V> reduceValues
5445	>	(ConcurrentHashMap<K,V> map,
5446	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5447	>	if (reducer == null) throw new NullPointerException();
5448	>	return new ReduceValuesTask<K,V>
5449	>	(map, null, -1, null, reducer);
5450	>	}
5451	>
5452	>	/**
5453	>	* Returns a task that when invoked, returns the result of
5454	>	* accumulating the given transformation of all values using the
5455	>	* given reducer to combine values, or null if none.
5456	>	*
5457	>	* @param map the map
5458	>	* @param transformer a function returning the transformation
5459	>	* for an element, or null if there is no transformation (in
5460	>	* which case it is not combined)
5461	>	* @param reducer a commutative associative combining function
5462	>	* @return the task
5463	>	*/
5464	>	public static <K,V,U> ForkJoinTask<U> reduceValues
5465	>	(ConcurrentHashMap<K,V> map,
5466	>	Function<? super V, ? extends U> transformer,
5467	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5468	>	if (transformer == null || reducer == null)
5469	>	throw new NullPointerException();
5470	>	return new MapReduceValuesTask<K,V,U>
5471	>	(map, null, -1, null, transformer, reducer);
5472	>	}
5473	>
5474	>	/**
5475	>	* Returns a task that when invoked, returns the result of
5476	>	* accumulating the given transformation of all values using the
5477	>	* given reducer to combine values, and the given basis as an
5478	>	* identity value.
5479	>	*
5480	>	* @param map the map
5481	>	* @param transformer a function returning the transformation
5482	>	* for an element
5483	>	* @param basis the identity (initial default value) for the reduction
5484	>	* @param reducer a commutative associative combining function
5485	>	* @return the task
5486	>	*/
5487	>	public static <K,V> ForkJoinTask<Double> reduceValuesToDouble
5488	>	(ConcurrentHashMap<K,V> map,
5489	>	ToDoubleFunction<? super V> transformer,
5490	>	double basis,
5491	>	DoubleBinaryOperator reducer) {
5492	>	if (transformer == null || reducer == null)
5493	>	throw new NullPointerException();
5494	>	return new MapReduceValuesToDoubleTask<K,V>
5495	>	(map, null, -1, null, transformer, basis, reducer);
5496	>	}
5497	>
5498	>	/**
5499	>	* Returns a task that when invoked, returns the result of
5500	>	* accumulating the given transformation of all values using the
5501	>	* given reducer to combine values, and the given basis as an
5502	>	* identity value.
5503	>	*
5504	>	* @param map the map
5505	>	* @param transformer a function returning the transformation
5506	>	* for an element
5507	>	* @param basis the identity (initial default value) for the reduction
5508	>	* @param reducer a commutative associative combining function
5509	>	* @return the task
5510	>	*/
5511	>	public static <K,V> ForkJoinTask<Long> reduceValuesToLong
5512	>	(ConcurrentHashMap<K,V> map,
5513	>	ToLongFunction<? super V> transformer,
5514	>	long basis,
5515	>	LongBinaryOperator reducer) {
5516	>	if (transformer == null || reducer == null)
5517	>	throw new NullPointerException();
5518	>	return new MapReduceValuesToLongTask<K,V>
5519	>	(map, null, -1, null, transformer, basis, reducer);
5520	>	}
5521	>
5522	>	/**
5523	>	* Returns a task that when invoked, returns the result of
5524	>	* accumulating the given transformation of all values using the
5525	>	* given reducer to combine values, and the given basis as an
5526	>	* identity value.
5527	>	*
5528	>	* @param map the map
5529	>	* @param transformer a function returning the transformation
5530	>	* for an element
5531	>	* @param basis the identity (initial default value) for the reduction
5532	>	* @param reducer a commutative associative combining function
5533	>	* @return the task
5534	>	*/
5535	>	public static <K,V> ForkJoinTask<Integer> reduceValuesToInt
5536	>	(ConcurrentHashMap<K,V> map,
5537	>	ToIntFunction<? super V> transformer,
5538	>	int basis,
5539	>	IntBinaryOperator reducer) {
5540	>	if (transformer == null || reducer == null)
5541	>	throw new NullPointerException();
5542	>	return new MapReduceValuesToIntTask<K,V>
5543	>	(map, null, -1, null, transformer, basis, reducer);
5544	>	}
5545	>
5546	>	/**
5547	>	* Returns a task that when invoked, perform the given action
5548	>	* for each entry.
5549	>	*
5550	>	* @param map the map
5551	>	* @param action the action
5552	>	* @return the task
5553	>	*/
5554	>	public static <K,V> ForkJoinTask<Void> forEachEntry
5555	>	(ConcurrentHashMap<K,V> map,
5556	>	Consumer<? super Map.Entry<K,V>> action) {
5557	>	if (action == null) throw new NullPointerException();
5558	>	return new ForEachEntryTask<K,V>(map, null, -1, action);
5559	>	}
5560	>
5561	>	/**
5562	>	* Returns a task that when invoked, perform the given action
5563	>	* for each non-null transformation of each entry.
5564	>	*
5565	>	* @param map the map
5566	>	* @param transformer a function returning the transformation
5567	>	* for an element, or null if there is no transformation (in
5568	>	* which case the action is not applied)
5569	>	* @param action the action
5570	>	* @return the task
5571	>	*/
5572	>	public static <K,V,U> ForkJoinTask<Void> forEachEntry
5573	>	(ConcurrentHashMap<K,V> map,
5574	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5575	>	Consumer<? super U> action) {
5576	>	if (transformer == null || action == null)
5577	>	throw new NullPointerException();
5578	>	return new ForEachTransformedEntryTask<K,V,U>
5579	>	(map, null, -1, transformer, action);
5580	>	}
5581	>
5582	>	/**
5583	>	* Returns a task that when invoked, returns a non-null result
5584	>	* from applying the given search function on each entry, or
5585	>	* null if none.  Upon success, further element processing is
5586	>	* suppressed and the results of any other parallel
5587	>	* invocations of the search function are ignored.
5588	>	*
5589	>	* @param map the map
5590	>	* @param searchFunction a function returning a non-null
5591	>	* result on success, else null
5592	>	* @return the task
5593	>	*/
5594	>	public static <K,V,U> ForkJoinTask<U> searchEntries
5595	>	(ConcurrentHashMap<K,V> map,
5596	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
5597	>	if (searchFunction == null) throw new NullPointerException();
5598	>	return new SearchEntriesTask<K,V,U>
5599	>	(map, null, -1, searchFunction,
5600	>	new AtomicReference<U>());
5601	>	}
5602	>
5603	>	/**
5604	>	* Returns a task that when invoked, returns the result of
5605	>	* accumulating all entries using the given reducer to combine
5606	>	* values, or null if none.
5607	>	*
5608	>	* @param map the map
5609	>	* @param reducer a commutative associative combining function
5610	>	* @return the task
5611	>	*/
5612	>	public static <K,V> ForkJoinTask<Map.Entry<K,V>> reduceEntries
5613	>	(ConcurrentHashMap<K,V> map,
5614	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5615	>	if (reducer == null) throw new NullPointerException();
5616	>	return new ReduceEntriesTask<K,V>
5617	>	(map, null, -1, null, reducer);
5618	>	}
5619	>
5620	>	/**
5621	>	* Returns a task that when invoked, returns the result of
5622	>	* accumulating the given transformation of all entries using the
5623	>	* given reducer to combine values, or null if none.
5624	>	*
5625	>	* @param map the map
5626	>	* @param transformer a function returning the transformation
5627	>	* for an element, or null if there is no transformation (in
5628	>	* which case it is not combined)
5629	>	* @param reducer a commutative associative combining function
5630	>	* @return the task
5631	>	*/
5632	>	public static <K,V,U> ForkJoinTask<U> reduceEntries
5633	>	(ConcurrentHashMap<K,V> map,
5634	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5635	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5636	>	if (transformer == null || reducer == null)
5637	>	throw new NullPointerException();
5638	>	return new MapReduceEntriesTask<K,V,U>
5639	>	(map, null, -1, null, transformer, reducer);
5640	>	}
5641	>
5642	>	/**
5643	>	* Returns a task that when invoked, returns the result of
5644	>	* accumulating the given transformation of all entries using the
5645	>	* given reducer to combine values, and the given basis as an
5646	>	* identity value.
5647	>	*
5648	>	* @param map the map
5649	>	* @param transformer a function returning the transformation
5650	>	* for an element
5651	>	* @param basis the identity (initial default value) for the reduction
5652	>	* @param reducer a commutative associative combining function
5653	>	* @return the task
5654	>	*/
5655	>	public static <K,V> ForkJoinTask<Double> reduceEntriesToDouble
5656	>	(ConcurrentHashMap<K,V> map,
5657	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5658	>	double basis,
5659	>	DoubleBinaryOperator reducer) {
5660	>	if (transformer == null || reducer == null)
5661	>	throw new NullPointerException();
5662	>	return new MapReduceEntriesToDoubleTask<K,V>
5663	>	(map, null, -1, null, transformer, basis, reducer);
5664	>	}
5665	>
5666	>	/**
5667	>	* Returns a task that when invoked, returns the result of
5668	>	* accumulating the given transformation of all entries using the
5669	>	* given reducer to combine values, and the given basis as an
5670	>	* identity value.
5671	>	*
5672	>	* @param map the map
5673	>	* @param transformer a function returning the transformation
5674	>	* for an element
5675	>	* @param basis the identity (initial default value) for the reduction
5676	>	* @param reducer a commutative associative combining function
5677	>	* @return the task
5678	>	*/
5679	>	public static <K,V> ForkJoinTask<Long> reduceEntriesToLong
5680	>	(ConcurrentHashMap<K,V> map,
5681	>	ToLongFunction<Map.Entry<K,V>> transformer,
5682	>	long basis,
5683	>	LongBinaryOperator reducer) {
5684	>	if (transformer == null || reducer == null)
5685	>	throw new NullPointerException();
5686	>	return new MapReduceEntriesToLongTask<K,V>
5687	>	(map, null, -1, null, transformer, basis, reducer);
5688	>	}
5689	>
5690	>	/**
5691	>	* Returns a task that when invoked, returns the result of
5692	>	* accumulating the given transformation of all entries using the
5693	>	* given reducer to combine values, and the given basis as an
5694	>	* identity value.
5695	>	*
5696	>	* @param map the map
5697	>	* @param transformer a function returning the transformation
5698	>	* for an element
5699	>	* @param basis the identity (initial default value) for the reduction
5700	>	* @param reducer a commutative associative combining function
5701	>	* @return the task
5702	>	*/
5703	>	public static <K,V> ForkJoinTask<Integer> reduceEntriesToInt
5704	>	(ConcurrentHashMap<K,V> map,
5705	>	ToIntFunction<Map.Entry<K,V>> transformer,
5706	>	int basis,
5707	>	IntBinaryOperator reducer) {
5708	>	if (transformer == null || reducer == null)
5709	>	throw new NullPointerException();
5710	>	return new MapReduceEntriesToIntTask<K,V>
5711	>	(map, null, -1, null, transformer, basis, reducer);
5712	>	}
5713	>	}
5714	>
5715	>	// -------------------------------------------------------
5716	>
5717	>	/*
5718	>	* Task classes. Coded in a regular but ugly format/style to
5719	>	* simplify checks that each variant differs in the right way from
5720	>	* others. The null screenings exist because compilers cannot tell
5721	>	* that we've already null-checked task arguments, so we force
5722	>	* simplest hoisted bypass to help avoid convoluted traps.
5723	>	*/
5724	>
5725	>	@SuppressWarnings("serial") static final class ForEachKeyTask<K,V>
5726	>	extends Traverser<K,V,Void> {
5727	>	final Consumer<? super K> action;
5728	>	ForEachKeyTask
5729	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5730	>	Consumer<? super K> action) {
5731	>	super(m, p, b);
5732	>	this.action = action;
5733	>	}
5734	>	public final void compute() {
5735	>	final Consumer<? super K> action;
5736	>	if ((action = this.action) != null) {
5737	>	for (int b; (b = preSplit()) > 0;)
5738	>	new ForEachKeyTask<K,V>(map, this, b, action).fork();
5739	>	forEachKey(action);
5740	>	propagateCompletion();
5741	>	}
5742	>	}
5743	>	}
5744	>
5745	>	@SuppressWarnings("serial") static final class ForEachValueTask<K,V>
5746	>	extends Traverser<K,V,Void> {
5747	>	final Consumer<? super V> action;
5748	>	ForEachValueTask
5749	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5750	>	Consumer<? super V> action) {
5751	>	super(m, p, b);
5752	>	this.action = action;
5753	>	}
5754	>	public final void compute() {
5755	>	final Consumer<? super V> action;
5756	>	if ((action = this.action) != null) {
5757	>	for (int b; (b = preSplit()) > 0;)
5758	>	new ForEachValueTask<K,V>(map, this, b, action).fork();
5759	>	forEachValue(action);
5760	>	propagateCompletion();
5761	>	}
5762	>	}
5763	>	}
5764	>
5765	>	@SuppressWarnings("serial") static final class ForEachEntryTask<K,V>
5766	>	extends Traverser<K,V,Void> {
5767	>	final Consumer<? super Entry<K,V>> action;
5768	>	ForEachEntryTask
5769	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5770	>	Consumer<? super Entry<K,V>> action) {
5771	>	super(m, p, b);
5772	>	this.action = action;
5773	>	}
5774	>	public final void compute() {
5775	>	final Consumer<? super Entry<K,V>> action;
5776	>	if ((action = this.action) != null) {
5777	>	for (int b; (b = preSplit()) > 0;)
5778	>	new ForEachEntryTask<K,V>(map, this, b, action).fork();
5779	>	V v;
5780	>	while ((v = advanceValue()) != null)
5781	>	action.accept(entryFor(nextKey, v));
5782	>	propagateCompletion();
5783	>	}
5784	>	}
5785	>	}
5786	>
5787	>	@SuppressWarnings("serial") static final class ForEachMappingTask<K,V>
5788	>	extends Traverser<K,V,Void> {
5789	>	final BiConsumer<? super K, ? super V> action;
5790	>	ForEachMappingTask
5791	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5792	>	BiConsumer<? super K,? super V> action) {
5793	>	super(m, p, b);
5794	>	this.action = action;
5795	>	}
5796	>	public final void compute() {
5797	>	final BiConsumer<? super K, ? super V> action;
5798	>	if ((action = this.action) != null) {
5799	>	for (int b; (b = preSplit()) > 0;)
5800	>	new ForEachMappingTask<K,V>(map, this, b, action).fork();
5801	>	V v;
5802	>	while ((v = advanceValue()) != null)
5803	>	action.accept(nextKey, v);
5804	>	propagateCompletion();
5805	>	}
5806	>	}
5807	>	}
5808	>
5809	>	@SuppressWarnings("serial") static final class ForEachTransformedKeyTask<K,V,U>
5810	>	extends Traverser<K,V,Void> {
5811	>	final Function<? super K, ? extends U> transformer;
5812	>	final Consumer<? super U> action;
5813	>	ForEachTransformedKeyTask
5814	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5815	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5816	>	super(m, p, b);
5817	>	this.transformer = transformer; this.action = action;
5818	>	}
5819	>	public final void compute() {
5820	>	final Function<? super K, ? extends U> transformer;
5821	>	final Consumer<? super U> action;
5822	>	if ((transformer = this.transformer) != null &&
5823	>	(action = this.action) != null) {
5824	>	for (int b; (b = preSplit()) > 0;)
5825	>	new ForEachTransformedKeyTask<K,V,U>
5826	>	(map, this, b, transformer, action).fork();
5827	>	K k; U u;
5828	>	while ((k = advanceKey()) != null) {
5829	>	if ((u = transformer.apply(k)) != null)
5830	>	action.accept(u);
5831	>	}
5832	>	propagateCompletion();
5833	>	}
5834	>	}
5835	>	}
5836	>
5837	>	@SuppressWarnings("serial") static final class ForEachTransformedValueTask<K,V,U>
5838	>	extends Traverser<K,V,Void> {
5839	>	final Function<? super V, ? extends U> transformer;
5840	>	final Consumer<? super U> action;
5841	>	ForEachTransformedValueTask
5842	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5843	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5844	>	super(m, p, b);
5845	>	this.transformer = transformer; this.action = action;
5846	>	}
5847	>	public final void compute() {
5848	>	final Function<? super V, ? extends U> transformer;
5849	>	final Consumer<? super U> action;
5850	>	if ((transformer = this.transformer) != null &&
5851	>	(action = this.action) != null) {
5852	>	for (int b; (b = preSplit()) > 0;)
5853	>	new ForEachTransformedValueTask<K,V,U>
5854	>	(map, this, b, transformer, action).fork();
5855	>	V v; U u;
5856	>	while ((v = advanceValue()) != null) {
5857	>	if ((u = transformer.apply(v)) != null)
5858	>	action.accept(u);
5859	>	}
5860	>	propagateCompletion();
5861	>	}
5862	>	}
5863	>	}
5864	>
5865	>	@SuppressWarnings("serial") static final class ForEachTransformedEntryTask<K,V,U>
5866	>	extends Traverser<K,V,Void> {
5867	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5868	>	final Consumer<? super U> action;
5869	>	ForEachTransformedEntryTask
5870	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5871	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5872	>	super(m, p, b);
5873	>	this.transformer = transformer; this.action = action;
5874	>	}
5875	>	public final void compute() {
5876	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5877	>	final Consumer<? super U> action;
5878	>	if ((transformer = this.transformer) != null &&
5879	>	(action = this.action) != null) {
5880	>	for (int b; (b = preSplit()) > 0;)
5881	>	new ForEachTransformedEntryTask<K,V,U>
5882	>	(map, this, b, transformer, action).fork();
5883	>	V v; U u;
5884	>	while ((v = advanceValue()) != null) {
5885	>	if ((u = transformer.apply(entryFor(nextKey,
5886	>	v))) != null)
5887	>	action.accept(u);
5888	>	}
5889	>	propagateCompletion();
5890	>	}
5891	>	}
5892	>	}
5893	>
5894	>	@SuppressWarnings("serial") static final class ForEachTransformedMappingTask<K,V,U>
5895	>	extends Traverser<K,V,Void> {
5896	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5897	>	final Consumer<? super U> action;
5898	>	ForEachTransformedMappingTask
5899	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5900	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5901	>	Consumer<? super U> action) {
5902	>	super(m, p, b);
5903	>	this.transformer = transformer; this.action = action;
5904	>	}
5905	>	public final void compute() {
5906	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5907	>	final Consumer<? super U> action;
5908	>	if ((transformer = this.transformer) != null &&
5909	>	(action = this.action) != null) {
5910	>	for (int b; (b = preSplit()) > 0;)
5911	>	new ForEachTransformedMappingTask<K,V,U>
5912	>	(map, this, b, transformer, action).fork();
5913	>	V v; U u;
5914	>	while ((v = advanceValue()) != null) {
5915	>	if ((u = transformer.apply(nextKey, v)) != null)
5916	>	action.accept(u);
5917	>	}
5918	>	propagateCompletion();
5919	>	}
5920	>	}
5921	>	}
5922	>
5923	>	@SuppressWarnings("serial") static final class SearchKeysTask<K,V,U>
5924	>	extends Traverser<K,V,U> {
5925	>	final Function<? super K, ? extends U> searchFunction;
5926	>	final AtomicReference<U> result;
5927	>	SearchKeysTask
5928	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5929	>	Function<? super K, ? extends U> searchFunction,
5930	>	AtomicReference<U> result) {
5931	>	super(m, p, b);
5932	>	this.searchFunction = searchFunction; this.result = result;
5933	>	}
5934	>	public final U getRawResult() { return result.get(); }
5935	>	public final void compute() {
5936	>	final Function<? super K, ? extends U> searchFunction;
5937	>	final AtomicReference<U> result;
5938	>	if ((searchFunction = this.searchFunction) != null &&
5939	>	(result = this.result) != null) {
5940	>	for (int b;;) {
5941	>	if (result.get() != null)
5942	>	return;
5943	>	if ((b = preSplit()) <= 0)
5944	>	break;
5945	>	new SearchKeysTask<K,V,U>
5946	>	(map, this, b, searchFunction, result).fork();
5947	>	}
5948	>	while (result.get() == null) {
5949	>	K k; U u;
5950	>	if ((k = advanceKey()) == null) {
5951	>	propagateCompletion();
5952	>	break;
5953	>	}
5954	>	if ((u = searchFunction.apply(k)) != null) {
5955	>	if (result.compareAndSet(null, u))
5956	>	quietlyCompleteRoot();
5957	>	break;
5958	>	}
5959	>	}
5960	>	}
5961	>	}
5962	>	}
5963	>
5964	>	@SuppressWarnings("serial") static final class SearchValuesTask<K,V,U>
5965	>	extends Traverser<K,V,U> {
5966	>	final Function<? super V, ? extends U> searchFunction;
5967	>	final AtomicReference<U> result;
5968	>	SearchValuesTask
5969	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
5970	>	Function<? super V, ? extends U> searchFunction,
5971	>	AtomicReference<U> result) {
5972	>	super(m, p, b);
5973	>	this.searchFunction = searchFunction; this.result = result;
5974	>	}
5975	>	public final U getRawResult() { return result.get(); }
5976	>	public final void compute() {
5977	>	final Function<? super V, ? extends U> searchFunction;
5978	>	final AtomicReference<U> result;
5979	>	if ((searchFunction = this.searchFunction) != null &&
5980	>	(result = this.result) != null) {
5981	>	for (int b;;) {
5982	>	if (result.get() != null)
5983	>	return;
5984	>	if ((b = preSplit()) <= 0)
5985	>	break;
5986	>	new SearchValuesTask<K,V,U>
5987	>	(map, this, b, searchFunction, result).fork();
5988	>	}
5989	>	while (result.get() == null) {
5990	>	V v; U u;
5991	>	if ((v = advanceValue()) == null) {
5992	>	propagateCompletion();
5993	>	break;
5994	>	}
5995	>	if ((u = searchFunction.apply(v)) != null) {
5996	>	if (result.compareAndSet(null, u))
5997	>	quietlyCompleteRoot();
5998	>	break;
5999	>	}
6000	>	}
6001	>	}
6002	>	}
6003	>	}
6004	>
6005	>	@SuppressWarnings("serial") static final class SearchEntriesTask<K,V,U>
6006	>	extends Traverser<K,V,U> {
6007	>	final Function<Entry<K,V>, ? extends U> searchFunction;
6008	>	final AtomicReference<U> result;
6009	>	SearchEntriesTask
6010	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6011	>	Function<Entry<K,V>, ? extends U> searchFunction,
6012	>	AtomicReference<U> result) {
6013	>	super(m, p, b);
6014	>	this.searchFunction = searchFunction; this.result = result;
6015	>	}
6016	>	public final U getRawResult() { return result.get(); }
6017	>	public final void compute() {
6018	>	final Function<Entry<K,V>, ? extends U> searchFunction;
6019	>	final AtomicReference<U> result;
6020	>	if ((searchFunction = this.searchFunction) != null &&
6021	>	(result = this.result) != null) {
6022	>	for (int b;;) {
6023	>	if (result.get() != null)
6024	>	return;
6025	>	if ((b = preSplit()) <= 0)
6026	>	break;
6027	>	new SearchEntriesTask<K,V,U>
6028	>	(map, this, b, searchFunction, result).fork();
6029	>	}
6030	>	while (result.get() == null) {
6031	>	V v; U u;
6032	>	if ((v = advanceValue()) == null) {
6033	>	propagateCompletion();
6034	>	break;
6035	>	}
6036	>	if ((u = searchFunction.apply(entryFor(nextKey,
6037	>	v))) != null) {
6038	>	if (result.compareAndSet(null, u))
6039	>	quietlyCompleteRoot();
6040	>	return;
6041	>	}
6042	>	}
6043	>	}
6044	>	}
6045	>	}
6046	>
6047	>	@SuppressWarnings("serial") static final class SearchMappingsTask<K,V,U>
6048	>	extends Traverser<K,V,U> {
6049	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
6050	>	final AtomicReference<U> result;
6051	>	SearchMappingsTask
6052	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6053	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
6054	>	AtomicReference<U> result) {
6055	>	super(m, p, b);
6056	>	this.searchFunction = searchFunction; this.result = result;
6057	>	}
6058	>	public final U getRawResult() { return result.get(); }
6059	>	public final void compute() {
6060	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
6061	>	final AtomicReference<U> result;
6062	>	if ((searchFunction = this.searchFunction) != null &&
6063	>	(result = this.result) != null) {
6064	>	for (int b;;) {
6065	>	if (result.get() != null)
6066	>	return;
6067	>	if ((b = preSplit()) <= 0)
6068	>	break;
6069	>	new SearchMappingsTask<K,V,U>
6070	>	(map, this, b, searchFunction, result).fork();
6071	>	}
6072	>	while (result.get() == null) {
6073	>	V v; U u;
6074	>	if ((v = advanceValue()) == null) {
6075	>	propagateCompletion();
6076	>	break;
6077	>	}
6078	>	if ((u = searchFunction.apply(nextKey, v)) != null) {
6079	>	if (result.compareAndSet(null, u))
6080	>	quietlyCompleteRoot();
6081	>	break;
6082	>	}
6083	>	}
6084	>	}
6085	>	}
6086	>	}
6087	>
6088	>	@SuppressWarnings("serial") static final class ReduceKeysTask<K,V>
6089	>	extends Traverser<K,V,K> {
6090	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
6091	>	K result;
6092	>	ReduceKeysTask<K,V> rights, nextRight;
6093	>	ReduceKeysTask
6094	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6095	>	ReduceKeysTask<K,V> nextRight,
6096	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
6097	>	super(m, p, b); this.nextRight = nextRight;
6098	>	this.reducer = reducer;
6099	>	}
6100	>	public final K getRawResult() { return result; }
6101	>	@SuppressWarnings("unchecked") public final void compute() {
6102	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
6103	>	if ((reducer = this.reducer) != null) {
6104	>	for (int b; (b = preSplit()) > 0;)
6105	>	(rights = new ReduceKeysTask<K,V>
6106	>	(map, this, b, rights, reducer)).fork();
6107	>	K u, r = null;
6108	>	while ((u = advanceKey()) != null) {
6109	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
6110	>	}
6111	>	result = r;
6112	>	CountedCompleter<?> c;
6113	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6114	>	ReduceKeysTask<K,V>
6115	>	t = (ReduceKeysTask<K,V>)c,
6116	>	s = t.rights;
6117	>	while (s != null) {
6118	>	K tr, sr;
6119	>	if ((sr = s.result) != null)
6120	>	t.result = (((tr = t.result) == null) ? sr :
6121	>	reducer.apply(tr, sr));
6122	>	s = t.rights = s.nextRight;
6123	>	}
6124	>	}
6125	>	}
6126	>	}
6127	>	}
6128	>
6129	>	@SuppressWarnings("serial") static final class ReduceValuesTask<K,V>
6130	>	extends Traverser<K,V,V> {
6131	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
6132	>	V result;
6133	>	ReduceValuesTask<K,V> rights, nextRight;
6134	>	ReduceValuesTask
6135	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6136	>	ReduceValuesTask<K,V> nextRight,
6137	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
6138	>	super(m, p, b); this.nextRight = nextRight;
6139	>	this.reducer = reducer;
6140	>	}
6141	>	public final V getRawResult() { return result; }
6142	>	@SuppressWarnings("unchecked") public final void compute() {
6143	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
6144	>	if ((reducer = this.reducer) != null) {
6145	>	for (int b; (b = preSplit()) > 0;)
6146	>	(rights = new ReduceValuesTask<K,V>
6147	>	(map, this, b, rights, reducer)).fork();
6148	>	V r = null, v;
6149	>	while ((v = advanceValue()) != null)
6150	>	r = (r == null) ? v : reducer.apply(r, v);
6151	>	result = r;
6152	>	CountedCompleter<?> c;
6153	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6154	>	ReduceValuesTask<K,V>
6155	>	t = (ReduceValuesTask<K,V>)c,
6156	>	s = t.rights;
6157	>	while (s != null) {
6158	>	V tr, sr;
6159	>	if ((sr = s.result) != null)
6160	>	t.result = (((tr = t.result) == null) ? sr :
6161	>	reducer.apply(tr, sr));
6162	>	s = t.rights = s.nextRight;
6163	>	}
6164	>	}
6165	>	}
6166	>	}
6167	>	}
6168	>
6169	>	@SuppressWarnings("serial") static final class ReduceEntriesTask<K,V>
6170	>	extends Traverser<K,V,Map.Entry<K,V>> {
6171	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
6172	>	Map.Entry<K,V> result;
6173	>	ReduceEntriesTask<K,V> rights, nextRight;
6174	>	ReduceEntriesTask
6175	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6176	>	ReduceEntriesTask<K,V> nextRight,
6177	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
6178	>	super(m, p, b); this.nextRight = nextRight;
6179	>	this.reducer = reducer;
6180	>	}
6181	>	public final Map.Entry<K,V> getRawResult() { return result; }
6182	>	@SuppressWarnings("unchecked") public final void compute() {
6183	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
6184	>	if ((reducer = this.reducer) != null) {
6185	>	for (int b; (b = preSplit()) > 0;)
6186	>	(rights = new ReduceEntriesTask<K,V>
6187	>	(map, this, b, rights, reducer)).fork();
6188	>	Map.Entry<K,V> r = null;
6189	>	V v;
6190	>	while ((v = advanceValue()) != null) {
6191	>	Map.Entry<K,V> u = entryFor(nextKey, v);
6192	>	r = (r == null) ? u : reducer.apply(r, u);
6193	>	}
6194	>	result = r;
6195	>	CountedCompleter<?> c;
6196	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6197	>	ReduceEntriesTask<K,V>
6198	>	t = (ReduceEntriesTask<K,V>)c,
6199	>	s = t.rights;
6200	>	while (s != null) {
6201	>	Map.Entry<K,V> tr, sr;
6202	>	if ((sr = s.result) != null)
6203	>	t.result = (((tr = t.result) == null) ? sr :
6204	>	reducer.apply(tr, sr));
6205	>	s = t.rights = s.nextRight;
6206	>	}
6207	>	}
6208	>	}
6209	>	}
6210	>	}
6211	>
6212	>	@SuppressWarnings("serial") static final class MapReduceKeysTask<K,V,U>
6213	>	extends Traverser<K,V,U> {
6214	>	final Function<? super K, ? extends U> transformer;
6215	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6216	>	U result;
6217	>	MapReduceKeysTask<K,V,U> rights, nextRight;
6218	>	MapReduceKeysTask
6219	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6220	>	MapReduceKeysTask<K,V,U> nextRight,
6221	>	Function<? super K, ? extends U> transformer,
6222	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6223	>	super(m, p, b); this.nextRight = nextRight;
6224	>	this.transformer = transformer;
6225	>	this.reducer = reducer;
6226	>	}
6227	>	public final U getRawResult() { return result; }
6228	>	@SuppressWarnings("unchecked") public final void compute() {
6229	>	final Function<? super K, ? extends U> transformer;
6230	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6231	>	if ((transformer = this.transformer) != null &&
6232	>	(reducer = this.reducer) != null) {
6233	>	for (int b; (b = preSplit()) > 0;)
6234	>	(rights = new MapReduceKeysTask<K,V,U>
6235	>	(map, this, b, rights, transformer, reducer)).fork();
6236	>	K k; U r = null, u;
6237	>	while ((k = advanceKey()) != null) {
6238	>	if ((u = transformer.apply(k)) != null)
6239	>	r = (r == null) ? u : reducer.apply(r, u);
6240	>	}
6241	>	result = r;
6242	>	CountedCompleter<?> c;
6243	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6244	>	MapReduceKeysTask<K,V,U>
6245	>	t = (MapReduceKeysTask<K,V,U>)c,
6246	>	s = t.rights;
6247	>	while (s != null) {
6248	>	U tr, sr;
6249	>	if ((sr = s.result) != null)
6250	>	t.result = (((tr = t.result) == null) ? sr :
6251	>	reducer.apply(tr, sr));
6252	>	s = t.rights = s.nextRight;
6253	>	}
6254	>	}
6255	>	}
6256	>	}
6257	>	}
6258	>
6259	>	@SuppressWarnings("serial") static final class MapReduceValuesTask<K,V,U>
6260	>	extends Traverser<K,V,U> {
6261	>	final Function<? super V, ? extends U> transformer;
6262	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6263	>	U result;
6264	>	MapReduceValuesTask<K,V,U> rights, nextRight;
6265	>	MapReduceValuesTask
6266	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6267	>	MapReduceValuesTask<K,V,U> nextRight,
6268	>	Function<? super V, ? extends U> transformer,
6269	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6270	>	super(m, p, b); this.nextRight = nextRight;
6271	>	this.transformer = transformer;
6272	>	this.reducer = reducer;
6273	>	}
6274	>	public final U getRawResult() { return result; }
6275	>	@SuppressWarnings("unchecked") public final void compute() {
6276	>	final Function<? super V, ? extends U> transformer;
6277	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6278	>	if ((transformer = this.transformer) != null &&
6279	>	(reducer = this.reducer) != null) {
6280	>	for (int b; (b = preSplit()) > 0;)
6281	>	(rights = new MapReduceValuesTask<K,V,U>
6282	>	(map, this, b, rights, transformer, reducer)).fork();
6283	>	U r = null, u;
6284	>	V v;
6285	>	while ((v = advanceValue()) != null) {
6286	>	if ((u = transformer.apply(v)) != null)
6287	>	r = (r == null) ? u : reducer.apply(r, u);
6288	>	}
6289	>	result = r;
6290	>	CountedCompleter<?> c;
6291	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6292	>	MapReduceValuesTask<K,V,U>
6293	>	t = (MapReduceValuesTask<K,V,U>)c,
6294	>	s = t.rights;
6295	>	while (s != null) {
6296	>	U tr, sr;
6297	>	if ((sr = s.result) != null)
6298	>	t.result = (((tr = t.result) == null) ? sr :
6299	>	reducer.apply(tr, sr));
6300	>	s = t.rights = s.nextRight;
6301	>	}
6302	>	}
6303	>	}
6304	>	}
6305	>	}
6306	>
6307	>	@SuppressWarnings("serial") static final class MapReduceEntriesTask<K,V,U>
6308	>	extends Traverser<K,V,U> {
6309	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
6310	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6311	>	U result;
6312	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
6313	>	MapReduceEntriesTask
6314	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6315	>	MapReduceEntriesTask<K,V,U> nextRight,
6316	>	Function<Map.Entry<K,V>, ? extends U> transformer,
6317	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6318	>	super(m, p, b); this.nextRight = nextRight;
6319	>	this.transformer = transformer;
6320	>	this.reducer = reducer;
6321	>	}
6322	>	public final U getRawResult() { return result; }
6323	>	@SuppressWarnings("unchecked") public final void compute() {
6324	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
6325	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6326	>	if ((transformer = this.transformer) != null &&
6327	>	(reducer = this.reducer) != null) {
6328	>	for (int b; (b = preSplit()) > 0;)
6329	>	(rights = new MapReduceEntriesTask<K,V,U>
6330	>	(map, this, b, rights, transformer, reducer)).fork();
6331	>	U r = null, u;
6332	>	V v;
6333	>	while ((v = advanceValue()) != null) {
6334	>	if ((u = transformer.apply(entryFor(nextKey,
6335	>	v))) != null)
6336	>	r = (r == null) ? u : reducer.apply(r, u);
6337	>	}
6338	>	result = r;
6339	>	CountedCompleter<?> c;
6340	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6341	>	MapReduceEntriesTask<K,V,U>
6342	>	t = (MapReduceEntriesTask<K,V,U>)c,
6343	>	s = t.rights;
6344	>	while (s != null) {
6345	>	U tr, sr;
6346	>	if ((sr = s.result) != null)
6347	>	t.result = (((tr = t.result) == null) ? sr :
6348	>	reducer.apply(tr, sr));
6349	>	s = t.rights = s.nextRight;
6350	>	}
6351	>	}
6352	>	}
6353	>	}
6354	>	}
6355	>
6356	>	@SuppressWarnings("serial") static final class MapReduceMappingsTask<K,V,U>
6357	>	extends Traverser<K,V,U> {
6358	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
6359	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6360	>	U result;
6361	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
6362	>	MapReduceMappingsTask
6363	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6364	>	MapReduceMappingsTask<K,V,U> nextRight,
6365	>	BiFunction<? super K, ? super V, ? extends U> transformer,
6366	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
6367	>	super(m, p, b); this.nextRight = nextRight;
6368	>	this.transformer = transformer;
6369	>	this.reducer = reducer;
6370	>	}
6371	>	public final U getRawResult() { return result; }
6372	>	@SuppressWarnings("unchecked") public final void compute() {
6373	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
6374	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
6375	>	if ((transformer = this.transformer) != null &&
6376	>	(reducer = this.reducer) != null) {
6377	>	for (int b; (b = preSplit()) > 0;)
6378	>	(rights = new MapReduceMappingsTask<K,V,U>
6379	>	(map, this, b, rights, transformer, reducer)).fork();
6380	>	U r = null, u;
6381	>	V v;
6382	>	while ((v = advanceValue()) != null) {
6383	>	if ((u = transformer.apply(nextKey, v)) != null)
6384	>	r = (r == null) ? u : reducer.apply(r, u);
6385	>	}
6386	>	result = r;
6387	>	CountedCompleter<?> c;
6388	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6389	>	MapReduceMappingsTask<K,V,U>
6390	>	t = (MapReduceMappingsTask<K,V,U>)c,
6391	>	s = t.rights;
6392	>	while (s != null) {
6393	>	U tr, sr;
6394	>	if ((sr = s.result) != null)
6395	>	t.result = (((tr = t.result) == null) ? sr :
6396	>	reducer.apply(tr, sr));
6397	>	s = t.rights = s.nextRight;
6398	>	}
6399	>	}
6400	>	}
6401	>	}
6402	>	}
6403	>
6404	>	@SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask<K,V>
6405	>	extends Traverser<K,V,Double> {
6406	>	final ToDoubleFunction<? super K> transformer;
6407	>	final DoubleBinaryOperator reducer;
6408	>	final double basis;
6409	>	double result;
6410	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
6411	>	MapReduceKeysToDoubleTask
6412	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6413	>	MapReduceKeysToDoubleTask<K,V> nextRight,
6414	>	ToDoubleFunction<? super K> transformer,
6415	>	double basis,
6416	>	DoubleBinaryOperator reducer) {
6417	>	super(m, p, b); this.nextRight = nextRight;
6418	>	this.transformer = transformer;
6419	>	this.basis = basis; this.reducer = reducer;
6420	>	}
6421	>	public final Double getRawResult() { return result; }
6422	>	@SuppressWarnings("unchecked") public final void compute() {
6423	>	final ToDoubleFunction<? super K> transformer;
6424	>	final DoubleBinaryOperator reducer;
6425	>	if ((transformer = this.transformer) != null &&
6426	>	(reducer = this.reducer) != null) {
6427	>	double r = this.basis;
6428	>	for (int b; (b = preSplit()) > 0;)
6429	>	(rights = new MapReduceKeysToDoubleTask<K,V>
6430	>	(map, this, b, rights, transformer, r, reducer)).fork();
6431	>	K k;
6432	>	while ((k = advanceKey()) != null)
6433	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(k));
6434	>	result = r;
6435	>	CountedCompleter<?> c;
6436	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6437	>	MapReduceKeysToDoubleTask<K,V>
6438	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
6439	>	s = t.rights;
6440	>	while (s != null) {
6441	>	t.result = reducer.applyAsDouble(t.result, s.result);
6442	>	s = t.rights = s.nextRight;
6443	>	}
6444	>	}
6445	>	}
6446	>	}
6447	>	}
6448	>
6449	>	@SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask<K,V>
6450	>	extends Traverser<K,V,Double> {
6451	>	final ToDoubleFunction<? super V> transformer;
6452	>	final DoubleBinaryOperator reducer;
6453	>	final double basis;
6454	>	double result;
6455	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
6456	>	MapReduceValuesToDoubleTask
6457	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6458	>	MapReduceValuesToDoubleTask<K,V> nextRight,
6459	>	ToDoubleFunction<? super V> transformer,
6460	>	double basis,
6461	>	DoubleBinaryOperator reducer) {
6462	>	super(m, p, b); this.nextRight = nextRight;
6463	>	this.transformer = transformer;
6464	>	this.basis = basis; this.reducer = reducer;
6465	>	}
6466	>	public final Double getRawResult() { return result; }
6467	>	@SuppressWarnings("unchecked") public final void compute() {
6468	>	final ToDoubleFunction<? super V> transformer;
6469	>	final DoubleBinaryOperator reducer;
6470	>	if ((transformer = this.transformer) != null &&
6471	>	(reducer = this.reducer) != null) {
6472	>	double r = this.basis;
6473	>	for (int b; (b = preSplit()) > 0;)
6474	>	(rights = new MapReduceValuesToDoubleTask<K,V>
6475	>	(map, this, b, rights, transformer, r, reducer)).fork();
6476	>	V v;
6477	>	while ((v = advanceValue()) != null)
6478	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(v));
6479	>	result = r;
6480	>	CountedCompleter<?> c;
6481	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6482	>	MapReduceValuesToDoubleTask<K,V>
6483	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
6484	>	s = t.rights;
6485	>	while (s != null) {
6486	>	t.result = reducer.applyAsDouble(t.result, s.result);
6487	>	s = t.rights = s.nextRight;
6488	>	}
6489	>	}
6490	>	}
6491	>	}
6492	>	}
6493	>
6494	>	@SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask<K,V>
6495	>	extends Traverser<K,V,Double> {
6496	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6497	>	final DoubleBinaryOperator reducer;
6498	>	final double basis;
6499	>	double result;
6500	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
6501	>	MapReduceEntriesToDoubleTask
6502	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6503	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
6504	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
6505	>	double basis,
6506	>	DoubleBinaryOperator reducer) {
6507	>	super(m, p, b); this.nextRight = nextRight;
6508	>	this.transformer = transformer;
6509	>	this.basis = basis; this.reducer = reducer;
6510	>	}
6511	>	public final Double getRawResult() { return result; }
6512	>	@SuppressWarnings("unchecked") public final void compute() {
6513	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
6514	>	final DoubleBinaryOperator reducer;
6515	>	if ((transformer = this.transformer) != null &&
6516	>	(reducer = this.reducer) != null) {
6517	>	double r = this.basis;
6518	>	for (int b; (b = preSplit()) > 0;)
6519	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
6520	>	(map, this, b, rights, transformer, r, reducer)).fork();
6521	>	V v;
6522	>	while ((v = advanceValue()) != null)
6523	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(entryFor(nextKey,
6524	>	v)));
6525	>	result = r;
6526	>	CountedCompleter<?> c;
6527	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6528	>	MapReduceEntriesToDoubleTask<K,V>
6529	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
6530	>	s = t.rights;
6531	>	while (s != null) {
6532	>	t.result = reducer.applyAsDouble(t.result, s.result);
6533	>	s = t.rights = s.nextRight;
6534	>	}
6535	>	}
6536	>	}
6537	>	}
6538	>	}
6539	>
6540	>	@SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask<K,V>
6541	>	extends Traverser<K,V,Double> {
6542	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
6543	>	final DoubleBinaryOperator reducer;
6544	>	final double basis;
6545	>	double result;
6546	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
6547	>	MapReduceMappingsToDoubleTask
6548	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6549	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
6550	>	ToDoubleBiFunction<? super K, ? super V> transformer,
6551	>	double basis,
6552	>	DoubleBinaryOperator reducer) {
6553	>	super(m, p, b); this.nextRight = nextRight;
6554	>	this.transformer = transformer;
6555	>	this.basis = basis; this.reducer = reducer;
6556	>	}
6557	>	public final Double getRawResult() { return result; }
6558	>	@SuppressWarnings("unchecked") public final void compute() {
6559	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
6560	>	final DoubleBinaryOperator reducer;
6561	>	if ((transformer = this.transformer) != null &&
6562	>	(reducer = this.reducer) != null) {
6563	>	double r = this.basis;
6564	>	for (int b; (b = preSplit()) > 0;)
6565	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
6566	>	(map, this, b, rights, transformer, r, reducer)).fork();
6567	>	V v;
6568	>	while ((v = advanceValue()) != null)
6569	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(nextKey, v));
6570	>	result = r;
6571	>	CountedCompleter<?> c;
6572	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6573	>	MapReduceMappingsToDoubleTask<K,V>
6574	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
6575	>	s = t.rights;
6576	>	while (s != null) {
6577	>	t.result = reducer.applyAsDouble(t.result, s.result);
6578	>	s = t.rights = s.nextRight;
6579	>	}
6580	>	}
6581	>	}
6582	>	}
6583	>	}
6584	>
6585	>	@SuppressWarnings("serial") static final class MapReduceKeysToLongTask<K,V>
6586	>	extends Traverser<K,V,Long> {
6587	>	final ToLongFunction<? super K> transformer;
6588	>	final LongBinaryOperator reducer;
6589	>	final long basis;
6590	>	long result;
6591	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
6592	>	MapReduceKeysToLongTask
6593	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6594	>	MapReduceKeysToLongTask<K,V> nextRight,
6595	>	ToLongFunction<? super K> transformer,
6596	>	long basis,
6597	>	LongBinaryOperator reducer) {
6598	>	super(m, p, b); this.nextRight = nextRight;
6599	>	this.transformer = transformer;
6600	>	this.basis = basis; this.reducer = reducer;
6601	>	}
6602	>	public final Long getRawResult() { return result; }
6603	>	@SuppressWarnings("unchecked") public final void compute() {
6604	>	final ToLongFunction<? super K> transformer;
6605	>	final LongBinaryOperator reducer;
6606	>	if ((transformer = this.transformer) != null &&
6607	>	(reducer = this.reducer) != null) {
6608	>	long r = this.basis;
6609	>	for (int b; (b = preSplit()) > 0;)
6610	>	(rights = new MapReduceKeysToLongTask<K,V>
6611	>	(map, this, b, rights, transformer, r, reducer)).fork();
6612	>	K k;
6613	>	while ((k = advanceKey()) != null)
6614	>	r = reducer.applyAsLong(r, transformer.applyAsLong(k));
6615	>	result = r;
6616	>	CountedCompleter<?> c;
6617	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6618	>	MapReduceKeysToLongTask<K,V>
6619	>	t = (MapReduceKeysToLongTask<K,V>)c,
6620	>	s = t.rights;
6621	>	while (s != null) {
6622	>	t.result = reducer.applyAsLong(t.result, s.result);
6623	>	s = t.rights = s.nextRight;
6624	>	}
6625	>	}
6626	>	}
6627	>	}
6628	>	}
6629	>
6630	>	@SuppressWarnings("serial") static final class MapReduceValuesToLongTask<K,V>
6631	>	extends Traverser<K,V,Long> {
6632	>	final ToLongFunction<? super V> transformer;
6633	>	final LongBinaryOperator reducer;
6634	>	final long basis;
6635	>	long result;
6636	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
6637	>	MapReduceValuesToLongTask
6638	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6639	>	MapReduceValuesToLongTask<K,V> nextRight,
6640	>	ToLongFunction<? super V> transformer,
6641	>	long basis,
6642	>	LongBinaryOperator reducer) {
6643	>	super(m, p, b); this.nextRight = nextRight;
6644	>	this.transformer = transformer;
6645	>	this.basis = basis; this.reducer = reducer;
6646	>	}
6647	>	public final Long getRawResult() { return result; }
6648	>	@SuppressWarnings("unchecked") public final void compute() {
6649	>	final ToLongFunction<? super V> transformer;
6650	>	final LongBinaryOperator reducer;
6651	>	if ((transformer = this.transformer) != null &&
6652	>	(reducer = this.reducer) != null) {
6653	>	long r = this.basis;
6654	>	for (int b; (b = preSplit()) > 0;)
6655	>	(rights = new MapReduceValuesToLongTask<K,V>
6656	>	(map, this, b, rights, transformer, r, reducer)).fork();
6657	>	V v;
6658	>	while ((v = advanceValue()) != null)
6659	>	r = reducer.applyAsLong(r, transformer.applyAsLong(v));
6660	>	result = r;
6661	>	CountedCompleter<?> c;
6662	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6663	>	MapReduceValuesToLongTask<K,V>
6664	>	t = (MapReduceValuesToLongTask<K,V>)c,
6665	>	s = t.rights;
6666	>	while (s != null) {
6667	>	t.result = reducer.applyAsLong(t.result, s.result);
6668	>	s = t.rights = s.nextRight;
6669	>	}
6670	>	}
6671	>	}
6672	>	}
6673	>	}
6674	>
6675	>	@SuppressWarnings("serial") static final class MapReduceEntriesToLongTask<K,V>
6676	>	extends Traverser<K,V,Long> {
6677	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6678	>	final LongBinaryOperator reducer;
6679	>	final long basis;
6680	>	long result;
6681	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6682	>	MapReduceEntriesToLongTask
6683	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6684	>	MapReduceEntriesToLongTask<K,V> nextRight,
6685	>	ToLongFunction<Map.Entry<K,V>> transformer,
6686	>	long basis,
6687	>	LongBinaryOperator reducer) {
6688	>	super(m, p, b); this.nextRight = nextRight;
6689	>	this.transformer = transformer;
6690	>	this.basis = basis; this.reducer = reducer;
6691	>	}
6692	>	public final Long getRawResult() { return result; }
6693	>	@SuppressWarnings("unchecked") public final void compute() {
6694	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6695	>	final LongBinaryOperator reducer;
6696	>	if ((transformer = this.transformer) != null &&
6697	>	(reducer = this.reducer) != null) {
6698	>	long r = this.basis;
6699	>	for (int b; (b = preSplit()) > 0;)
6700	>	(rights = new MapReduceEntriesToLongTask<K,V>
6701	>	(map, this, b, rights, transformer, r, reducer)).fork();
6702	>	V v;
6703	>	while ((v = advanceValue()) != null)
6704	>	r = reducer.applyAsLong(r, transformer.applyAsLong(entryFor(nextKey, v)));
6705	>	result = r;
6706	>	CountedCompleter<?> c;
6707	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6708	>	MapReduceEntriesToLongTask<K,V>
6709	>	t = (MapReduceEntriesToLongTask<K,V>)c,
6710	>	s = t.rights;
6711	>	while (s != null) {
6712	>	t.result = reducer.applyAsLong(t.result, s.result);
6713	>	s = t.rights = s.nextRight;
6714	>	}
6715	>	}
6716	>	}
6717	>	}
6718	>	}
6719	>
6720	>	@SuppressWarnings("serial") static final class MapReduceMappingsToLongTask<K,V>
6721	>	extends Traverser<K,V,Long> {
6722	>	final ToLongBiFunction<? super K, ? super V> transformer;
6723	>	final LongBinaryOperator reducer;
6724	>	final long basis;
6725	>	long result;
6726	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6727	>	MapReduceMappingsToLongTask
6728	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6729	>	MapReduceMappingsToLongTask<K,V> nextRight,
6730	>	ToLongBiFunction<? super K, ? super V> transformer,
6731	>	long basis,
6732	>	LongBinaryOperator reducer) {
6733	>	super(m, p, b); this.nextRight = nextRight;
6734	>	this.transformer = transformer;
6735	>	this.basis = basis; this.reducer = reducer;
6736	>	}
6737	>	public final Long getRawResult() { return result; }
6738	>	@SuppressWarnings("unchecked") public final void compute() {
6739	>	final ToLongBiFunction<? super K, ? super V> transformer;
6740	>	final LongBinaryOperator reducer;
6741	>	if ((transformer = this.transformer) != null &&
6742	>	(reducer = this.reducer) != null) {
6743	>	long r = this.basis;
6744	>	for (int b; (b = preSplit()) > 0;)
6745	>	(rights = new MapReduceMappingsToLongTask<K,V>
6746	>	(map, this, b, rights, transformer, r, reducer)).fork();
6747	>	V v;
6748	>	while ((v = advanceValue()) != null)
6749	>	r = reducer.applyAsLong(r, transformer.applyAsLong(nextKey, v));
6750	>	result = r;
6751	>	CountedCompleter<?> c;
6752	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6753	>	MapReduceMappingsToLongTask<K,V>
6754	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6755	>	s = t.rights;
6756	>	while (s != null) {
6757	>	t.result = reducer.applyAsLong(t.result, s.result);
6758	>	s = t.rights = s.nextRight;
6759	>	}
6760	>	}
6761	>	}
6762	>	}
6763	>	}
6764	>
6765	>	@SuppressWarnings("serial") static final class MapReduceKeysToIntTask<K,V>
6766	>	extends Traverser<K,V,Integer> {
6767	>	final ToIntFunction<? super K> transformer;
6768	>	final IntBinaryOperator reducer;
6769	>	final int basis;
6770	>	int result;
6771	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6772	>	MapReduceKeysToIntTask
6773	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6774	>	MapReduceKeysToIntTask<K,V> nextRight,
6775	>	ToIntFunction<? super K> transformer,
6776	>	int basis,
6777	>	IntBinaryOperator reducer) {
6778	>	super(m, p, b); this.nextRight = nextRight;
6779	>	this.transformer = transformer;
6780	>	this.basis = basis; this.reducer = reducer;
6781	>	}
6782	>	public final Integer getRawResult() { return result; }
6783	>	@SuppressWarnings("unchecked") public final void compute() {
6784	>	final ToIntFunction<? super K> transformer;
6785	>	final IntBinaryOperator reducer;
6786	>	if ((transformer = this.transformer) != null &&
6787	>	(reducer = this.reducer) != null) {
6788	>	int r = this.basis;
6789	>	for (int b; (b = preSplit()) > 0;)
6790	>	(rights = new MapReduceKeysToIntTask<K,V>
6791	>	(map, this, b, rights, transformer, r, reducer)).fork();
6792	>	K k;
6793	>	while ((k = advanceKey()) != null)
6794	>	r = reducer.applyAsInt(r, transformer.applyAsInt(k));
6795	>	result = r;
6796	>	CountedCompleter<?> c;
6797	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6798	>	MapReduceKeysToIntTask<K,V>
6799	>	t = (MapReduceKeysToIntTask<K,V>)c,
6800	>	s = t.rights;
6801	>	while (s != null) {
6802	>	t.result = reducer.applyAsInt(t.result, s.result);
6803	>	s = t.rights = s.nextRight;
6804	>	}
6805	>	}
6806	>	}
6807	>	}
6808	>	}
6809	>
6810	>	@SuppressWarnings("serial") static final class MapReduceValuesToIntTask<K,V>
6811	>	extends Traverser<K,V,Integer> {
6812	>	final ToIntFunction<? super V> transformer;
6813	>	final IntBinaryOperator reducer;
6814	>	final int basis;
6815	>	int result;
6816	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6817	>	MapReduceValuesToIntTask
6818	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6819	>	MapReduceValuesToIntTask<K,V> nextRight,
6820	>	ToIntFunction<? super V> transformer,
6821	>	int basis,
6822	>	IntBinaryOperator reducer) {
6823	>	super(m, p, b); this.nextRight = nextRight;
6824	>	this.transformer = transformer;
6825	>	this.basis = basis; this.reducer = reducer;
6826	>	}
6827	>	public final Integer getRawResult() { return result; }
6828	>	@SuppressWarnings("unchecked") public final void compute() {
6829	>	final ToIntFunction<? super V> transformer;
6830	>	final IntBinaryOperator reducer;
6831	>	if ((transformer = this.transformer) != null &&
6832	>	(reducer = this.reducer) != null) {
6833	>	int r = this.basis;
6834	>	for (int b; (b = preSplit()) > 0;)
6835	>	(rights = new MapReduceValuesToIntTask<K,V>
6836	>	(map, this, b, rights, transformer, r, reducer)).fork();
6837	>	V v;
6838	>	while ((v = advanceValue()) != null)
6839	>	r = reducer.applyAsInt(r, transformer.applyAsInt(v));
6840	>	result = r;
6841	>	CountedCompleter<?> c;
6842	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6843	>	MapReduceValuesToIntTask<K,V>
6844	>	t = (MapReduceValuesToIntTask<K,V>)c,
6845	>	s = t.rights;
6846	>	while (s != null) {
6847	>	t.result = reducer.applyAsInt(t.result, s.result);
6848	>	s = t.rights = s.nextRight;
6849	>	}
6850	>	}
6851	>	}
6852	>	}
6853	>	}
6854	>
6855	>	@SuppressWarnings("serial") static final class MapReduceEntriesToIntTask<K,V>
6856	>	extends Traverser<K,V,Integer> {
6857	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6858	>	final IntBinaryOperator reducer;
6859	>	final int basis;
6860	>	int result;
6861	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6862	>	MapReduceEntriesToIntTask
6863	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6864	>	MapReduceEntriesToIntTask<K,V> nextRight,
6865	>	ToIntFunction<Map.Entry<K,V>> transformer,
6866	>	int basis,
6867	>	IntBinaryOperator reducer) {
6868	>	super(m, p, b); this.nextRight = nextRight;
6869	>	this.transformer = transformer;
6870	>	this.basis = basis; this.reducer = reducer;
6871	>	}
6872	>	public final Integer getRawResult() { return result; }
6873	>	@SuppressWarnings("unchecked") public final void compute() {
6874	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6875	>	final IntBinaryOperator reducer;
6876	>	if ((transformer = this.transformer) != null &&
6877	>	(reducer = this.reducer) != null) {
6878	>	int r = this.basis;
6879	>	for (int b; (b = preSplit()) > 0;)
6880	>	(rights = new MapReduceEntriesToIntTask<K,V>
6881	>	(map, this, b, rights, transformer, r, reducer)).fork();
6882	>	V v;
6883	>	while ((v = advanceValue()) != null)
6884	>	r = reducer.applyAsInt(r, transformer.applyAsInt(entryFor(nextKey,
6885	>	v)));
6886	>	result = r;
6887	>	CountedCompleter<?> c;
6888	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6889	>	MapReduceEntriesToIntTask<K,V>
6890	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6891	>	s = t.rights;
6892	>	while (s != null) {
6893	>	t.result = reducer.applyAsInt(t.result, s.result);
6894	>	s = t.rights = s.nextRight;
6895	>	}
6896	>	}
6897	>	}
6898	>	}
6899	>	}
6900	>
6901	>	@SuppressWarnings("serial") static final class MapReduceMappingsToIntTask<K,V>
6902	>	extends Traverser<K,V,Integer> {
6903	>	final ToIntBiFunction<? super K, ? super V> transformer;
6904	>	final IntBinaryOperator reducer;
6905	>	final int basis;
6906	>	int result;
6907	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6908	>	MapReduceMappingsToIntTask
6909	>	(ConcurrentHashMap<K,V> m, Traverser<K,V,?> p, int b,
6910	>	MapReduceMappingsToIntTask<K,V> nextRight,
6911	>	ToIntBiFunction<? super K, ? super V> transformer,
6912	>	int basis,
6913	>	IntBinaryOperator reducer) {
6914	>	super(m, p, b); this.nextRight = nextRight;
6915	>	this.transformer = transformer;
6916	>	this.basis = basis; this.reducer = reducer;
6917	>	}
6918	>	public final Integer getRawResult() { return result; }
6919	>	@SuppressWarnings("unchecked") public final void compute() {
6920	>	final ToIntBiFunction<? super K, ? super V> transformer;
6921	>	final IntBinaryOperator reducer;
6922	>	if ((transformer = this.transformer) != null &&
6923	>	(reducer = this.reducer) != null) {
6924	>	int r = this.basis;
6925	>	for (int b; (b = preSplit()) > 0;)
6926	>	(rights = new MapReduceMappingsToIntTask<K,V>
6927	>	(map, this, b, rights, transformer, r, reducer)).fork();
6928	>	V v;
6929	>	while ((v = advanceValue()) != null)
6930	>	r = reducer.applyAsInt(r, transformer.applyAsInt(nextKey, v));
6931	>	result = r;
6932	>	CountedCompleter<?> c;
6933	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6934	>	MapReduceMappingsToIntTask<K,V>
6935	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6936	>	s = t.rights;
6937	>	while (s != null) {
6938	>	t.result = reducer.applyAsInt(t.result, s.result);
6939	>	s = t.rights = s.nextRight;
6940	>	}
6941	>	}
6942	>	}
6943		}
6944		}
6945
6946		// Unsafe mechanics
6947	<	private static final sun.misc.Unsafe UNSAFE;
6948	<	private static final long SBASE;
6949	<	private static final int SSHIFT;
6950	<	private static final long TBASE;
6951	<	private static final int TSHIFT;
6947	>	private static final sun.misc.Unsafe U;
6948	>	private static final long SIZECTL;
6949	>	private static final long TRANSFERINDEX;
6950	>	private static final long TRANSFERORIGIN;
6951	>	private static final long BASECOUNT;
6952	>	private static final long CELLSBUSY;
6953	>	private static final long CELLVALUE;
6954	>	private static final long ABASE;
6955	>	private static final int ASHIFT;
6956
6957		static {
1467	–	int ss, ts;
6958		try {
6959	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6960	<	Class<?> tc = HashEntry[].class;
6961	<	Class<?> sc = Segment[].class;
6962	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6963	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6964	<	ts = UNSAFE.arrayIndexScale(tc);
6965	<	ss = UNSAFE.arrayIndexScale(sc);
6959	>	U = sun.misc.Unsafe.getUnsafe();
6960	>	Class<?> k = ConcurrentHashMap.class;
6961	>	SIZECTL = U.objectFieldOffset
6962	>	(k.getDeclaredField("sizeCtl"));
6963	>	TRANSFERINDEX = U.objectFieldOffset
6964	>	(k.getDeclaredField("transferIndex"));
6965	>	TRANSFERORIGIN = U.objectFieldOffset
6966	>	(k.getDeclaredField("transferOrigin"));
6967	>	BASECOUNT = U.objectFieldOffset
6968	>	(k.getDeclaredField("baseCount"));
6969	>	CELLSBUSY = U.objectFieldOffset
6970	>	(k.getDeclaredField("cellsBusy"));
6971	>	Class<?> ck = Cell.class;
6972	>	CELLVALUE = U.objectFieldOffset
6973	>	(ck.getDeclaredField("value"));
6974	>	Class<?> sc = Node[].class;
6975	>	ABASE = U.arrayBaseOffset(sc);
6976	>	int scale = U.arrayIndexScale(sc);
6977	>	if ((scale & (scale - 1)) != 0)
6978	>	throw new Error("data type scale not a power of two");
6979	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6980		} catch (Exception e) {
6981		throw new Error(e);
6982		}
1479	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1480	–	throw new Error("data type scale not a power of two");
1481	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1482	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6983		}
6984
6985		}

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