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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.112 by jsr166, Fri Jun 3 02:28:05 2011 UTC vs.
Revision 1.308 by jsr166, Mon Mar 12 03:29:09 2018 UTC

#	Line 5 | Line 5
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
16	>	import java.util.Enumeration;
17	>	import java.util.HashMap;
18	>	import java.util.Hashtable;
19	>	import java.util.Iterator;
20	>	import java.util.Map;
21	>	import java.util.NoSuchElementException;
22	>	import java.util.Set;
23	>	import java.util.Spliterator;
24	>	import java.util.concurrent.atomic.AtomicReference;
25	>	import java.util.concurrent.locks.LockSupport;
26	>	import java.util.concurrent.locks.ReentrantLock;
27	>	import java.util.function.BiConsumer;
28	>	import java.util.function.BiFunction;
29	>	import java.util.function.Consumer;
30	>	import java.util.function.DoubleBinaryOperator;
31	>	import java.util.function.Function;
32	>	import java.util.function.IntBinaryOperator;
33	>	import java.util.function.LongBinaryOperator;
34	>	import java.util.function.Predicate;
35	>	import java.util.function.ToDoubleBiFunction;
36	>	import java.util.function.ToDoubleFunction;
37	>	import java.util.function.ToIntBiFunction;
38	>	import java.util.function.ToIntFunction;
39	>	import java.util.function.ToLongBiFunction;
40	>	import java.util.function.ToLongFunction;
41	>	import java.util.stream.Stream;
42	>	import jdk.internal.misc.Unsafe;
43
44		/**
45		* A hash table supporting full concurrency of retrievals and
46	<	* adjustable expected concurrency for updates. This class obeys the
46	>	* high expected concurrency for updates. This class obeys the
47		* same functional specification as {@link java.util.Hashtable}, and
48		* includes versions of methods corresponding to each method of
49	<	* <tt>Hashtable</tt>. However, even though all operations are
49	>	* {@code Hashtable}. However, even though all operations are
50		* thread-safe, retrieval operations do <em>not</em> entail locking,
51		* and there is <em>not</em> any support for locking the entire table
52		* in a way that prevents all access.  This class is fully
53	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
53	>	* interoperable with {@code Hashtable} in programs that rely on its
54		* thread safety but not on its synchronization details.
55		*
56	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
57	<	* block, so may overlap with update operations (including
58	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
59	<	* of the most recently <em>completed</em> update operations holding
60	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
61	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
62	<	* removal of only some entries.  Similarly, Iterators and
63	<	* Enumerations return elements reflecting the state of the hash table
64	<	* at some point at or since the creation of the iterator/enumeration.
65	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
56	>	* <p>Retrieval operations (including {@code get}) generally do not
57	>	* block, so may overlap with update operations (including {@code put}
58	>	* and {@code remove}). Retrievals reflect the results of the most
59	>	* recently <em>completed</em> update operations holding upon their
60	>	* onset. (More formally, an update operation for a given key bears a
61	>	* <em>happens-before</em> relation with any (non-null) retrieval for
62	>	* that key reporting the updated value.)  For aggregate operations
63	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
64	>	* reflect insertion or removal of only some entries.  Similarly,
65	>	* Iterators, Spliterators and Enumerations return elements reflecting the
66	>	* state of the hash table at some point at or since the creation of the
67	>	* iterator/enumeration.  They do <em>not</em> throw {@link
68	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
69		* However, iterators are designed to be used by only one thread at a time.
70	+	* Bear in mind that the results of aggregate status methods including
71	+	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
72	+	* useful only when a map is not undergoing concurrent updates in other threads.
73	+	* Otherwise the results of these methods reflect transient states
74	+	* that may be adequate for monitoring or estimation purposes, but not
75	+	* for program control.
76	+	*
77	+	* <p>The table is dynamically expanded when there are too many
78	+	* collisions (i.e., keys that have distinct hash codes but fall into
79	+	* the same slot modulo the table size), with the expected average
80	+	* effect of maintaining roughly two bins per mapping (corresponding
81	+	* to a 0.75 load factor threshold for resizing). There may be much
82	+	* variance around this average as mappings are added and removed, but
83	+	* overall, this maintains a commonly accepted time/space tradeoff for
84	+	* hash tables.  However, resizing this or any other kind of hash
85	+	* table may be a relatively slow operation. When possible, it is a
86	+	* good idea to provide a size estimate as an optional {@code
87	+	* initialCapacity} constructor argument. An additional optional
88	+	* {@code loadFactor} constructor argument provides a further means of
89	+	* customizing initial table capacity by specifying the table density
90	+	* to be used in calculating the amount of space to allocate for the
91	+	* given number of elements.  Also, for compatibility with previous
92	+	* versions of this class, constructors may optionally specify an
93	+	* expected {@code concurrencyLevel} as an additional hint for
94	+	* internal sizing.  Note that using many keys with exactly the same
95	+	* {@code hashCode()} is a sure way to slow down performance of any
96	+	* hash table. To ameliorate impact, when keys are {@link Comparable},
97	+	* this class may use comparison order among keys to help break ties.
98	+	*
99	+	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
100	+	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
101	+	* (using {@link #keySet(Object)} when only keys are of interest, and the
102	+	* mapped values are (perhaps transiently) not used or all take the
103	+	* same mapping value.
104		*
105	<	* <p> The allowed concurrency among update operations is guided by
106	<	* the optional <tt>concurrencyLevel</tt> constructor argument
107	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
108	<	* table is internally partitioned to try to permit the indicated
109	<	* number of concurrent updates without contention. Because placement
110	<	* in hash tables is essentially random, the actual concurrency will
45	<	* vary.  Ideally, you should choose a value to accommodate as many
46	<	* threads as will ever concurrently modify the table. Using a
47	<	* significantly higher value than you need can waste space and time,
48	<	* and a significantly lower value can lead to thread contention. But
49	<	* overestimates and underestimates within an order of magnitude do
50	<	* not usually have much noticeable impact. A value of one is
51	<	* appropriate when it is known that only one thread will modify and
52	<	* all others will only read. Also, resizing this or any other kind of
53	<	* hash table is a relatively slow operation, so, when possible, it is
54	<	* a good idea to provide estimates of expected table sizes in
55	<	* constructors.
105	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
106	>	* form of histogram or multiset) by using {@link
107	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
108	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
109	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
110	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
111		*
112		* <p>This class and its views and iterators implement all of the
113		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
114		* interfaces.
115		*
116	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
117	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
116	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
117	>	* does <em>not</em> allow {@code null} to be used as a key or value.
118	>	*
119	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
120	>	* operations that, unlike most {@link Stream} methods, are designed
121	>	* to be safely, and often sensibly, applied even with maps that are
122	>	* being concurrently updated by other threads; for example, when
123	>	* computing a snapshot summary of the values in a shared registry.
124	>	* There are three kinds of operation, each with four forms, accepting
125	>	* functions with keys, values, entries, and (key, value) pairs as
126	>	* arguments and/or return values. Because the elements of a
127	>	* ConcurrentHashMap are not ordered in any particular way, and may be
128	>	* processed in different orders in different parallel executions, the
129	>	* correctness of supplied functions should not depend on any
130	>	* ordering, or on any other objects or values that may transiently
131	>	* change while computation is in progress; and except for forEach
132	>	* actions, should ideally be side-effect-free. Bulk operations on
133	>	* {@link Map.Entry} objects do not support method {@code setValue}.
134	>	*
135	>	* <ul>
136	>	* <li>forEach: Performs a given action on each element.
137	>	* A variant form applies a given transformation on each element
138	>	* before performing the action.
139	>	*
140	>	* <li>search: Returns the first available non-null result of
141	>	* applying a given function on each element; skipping further
142	>	* search when a result is found.
143	>	*
144	>	* <li>reduce: Accumulates each element.  The supplied reduction
145	>	* function cannot rely on ordering (more formally, it should be
146	>	* both associative and commutative).  There are five variants:
147	>	*
148	>	* <ul>
149	>	*
150	>	* <li>Plain reductions. (There is not a form of this method for
151	>	* (key, value) function arguments since there is no corresponding
152	>	* return type.)
153	>	*
154	>	* <li>Mapped reductions that accumulate the results of a given
155	>	* function applied to each element.
156	>	*
157	>	* <li>Reductions to scalar doubles, longs, and ints, using a
158	>	* given basis value.
159	>	*
160	>	* </ul>
161	>	* </ul>
162	>	*
163	>	* <p>These bulk operations accept a {@code parallelismThreshold}
164	>	* argument. Methods proceed sequentially if the current map size is
165	>	* estimated to be less than the given threshold. Using a value of
166	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
167	>	* of {@code 1} results in maximal parallelism by partitioning into
168	>	* enough subtasks to fully utilize the {@link
169	>	* ForkJoinPool#commonPool()} that is used for all parallel
170	>	* computations. Normally, you would initially choose one of these
171	>	* extreme values, and then measure performance of using in-between
172	>	* values that trade off overhead versus throughput.
173	>	*
174	>	* <p>The concurrency properties of bulk operations follow
175	>	* from those of ConcurrentHashMap: Any non-null result returned
176	>	* from {@code get(key)} and related access methods bears a
177	>	* happens-before relation with the associated insertion or
178	>	* update.  The result of any bulk operation reflects the
179	>	* composition of these per-element relations (but is not
180	>	* necessarily atomic with respect to the map as a whole unless it
181	>	* is somehow known to be quiescent).  Conversely, because keys
182	>	* and values in the map are never null, null serves as a reliable
183	>	* atomic indicator of the current lack of any result.  To
184	>	* maintain this property, null serves as an implicit basis for
185	>	* all non-scalar reduction operations. For the double, long, and
186	>	* int versions, the basis should be one that, when combined with
187	>	* any other value, returns that other value (more formally, it
188	>	* should be the identity element for the reduction). Most common
189	>	* reductions have these properties; for example, computing a sum
190	>	* with basis 0 or a minimum with basis MAX_VALUE.
191	>	*
192	>	* <p>Search and transformation functions provided as arguments
193	>	* should similarly return null to indicate the lack of any result
194	>	* (in which case it is not used). In the case of mapped
195	>	* reductions, this also enables transformations to serve as
196	>	* filters, returning null (or, in the case of primitive
197	>	* specializations, the identity basis) if the element should not
198	>	* be combined. You can create compound transformations and
199	>	* filterings by composing them yourself under this "null means
200	>	* there is nothing there now" rule before using them in search or
201	>	* reduce operations.
202	>	*
203	>	* <p>Methods accepting and/or returning Entry arguments maintain
204	>	* key-value associations. They may be useful for example when
205	>	* finding the key for the greatest value. Note that "plain" Entry
206	>	* arguments can be supplied using {@code new
207	>	* AbstractMap.SimpleEntry(k,v)}.
208	>	*
209	>	* <p>Bulk operations may complete abruptly, throwing an
210	>	* exception encountered in the application of a supplied
211	>	* function. Bear in mind when handling such exceptions that other
212	>	* concurrently executing functions could also have thrown
213	>	* exceptions, or would have done so if the first exception had
214	>	* not occurred.
215	>	*
216	>	* <p>Speedups for parallel compared to sequential forms are common
217	>	* but not guaranteed.  Parallel operations involving brief functions
218	>	* on small maps may execute more slowly than sequential forms if the
219	>	* underlying work to parallelize the computation is more expensive
220	>	* than the computation itself.  Similarly, parallelization may not
221	>	* lead to much actual parallelism if all processors are busy
222	>	* performing unrelated tasks.
223	>	*
224	>	* <p>All arguments to all task methods must be non-null.
225		*
226		* <p>This class is a member of the
227	<	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
227	>	* <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
228		* Java Collections Framework</a>.
229		*
230		* @since 1.5
#	Line 70 | Line 232 | import java.io.ObjectOutputStream;
232		* @param <K> the type of keys maintained by this map
233		* @param <V> the type of mapped values
234		*/
235	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
236	<	implements ConcurrentMap<K, V>, Serializable {
235	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
236	>	implements ConcurrentMap<K,V>, Serializable {
237		private static final long serialVersionUID = 7249069246763182397L;
238
239		/*
240	<	* The basic strategy is to subdivide the table among Segments,
241	<	* each of which itself is a concurrently readable hash table.  To
242	<	* reduce footprint, all but one segments are constructed only
243	<	* when first needed (see ensureSegment). To maintain visibility
244	<	* in the presence of lazy construction, accesses to segments as
245	<	* well as elements of segment's table must use volatile access,
246	<	* which is done via Unsafe within methods segmentAt etc
247	<	* below. These provide the functionality of AtomicReferenceArrays
248	<	* but reduce the levels of indirection. Additionally,
249	<	* volatile-writes of table elements and entry "next" fields
250	<	* within locked operations use the cheaper "lazySet" forms of
251	<	* writes (via putOrderedObject) because these writes are always
252	<	* followed by lock releases that maintain sequential consistency
253	<	* of table updates.
254	<	*
255	<	* Historical note: The previous version of this class relied
256	<	* heavily on "final" fields, which avoided some volatile reads at
257	<	* the expense of a large initial footprint.  Some remnants of
258	<	* that design (including forced construction of segment 0) exist
259	<	* to ensure serialization compatibility.
240	>	* Overview:
241	>	*
242	>	* The primary design goal of this hash table is to maintain
243	>	* concurrent readability (typically method get(), but also
244	>	* iterators and related methods) while minimizing update
245	>	* contention. Secondary goals are to keep space consumption about
246	>	* the same or better than java.util.HashMap, and to support high
247	>	* initial insertion rates on an empty table by many threads.
248	>	*
249	>	* This map usually acts as a binned (bucketed) hash table.  Each
250	>	* key-value mapping is held in a Node.  Most nodes are instances
251	>	* of the basic Node class with hash, key, value, and next
252	>	* fields. However, various subclasses exist: TreeNodes are
253	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
254	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
255	>	* of bins during resizing. ReservationNodes are used as
256	>	* placeholders while establishing values in computeIfAbsent and
257	>	* related methods.  The types TreeBin, ForwardingNode, and
258	>	* ReservationNode do not hold normal user keys, values, or
259	>	* hashes, and are readily distinguishable during search etc
260	>	* because they have negative hash fields and null key and value
261	>	* fields. (These special nodes are either uncommon or transient,
262	>	* so the impact of carrying around some unused fields is
263	>	* insignificant.)
264	>	*
265	>	* The table is lazily initialized to a power-of-two size upon the
266	>	* first insertion.  Each bin in the table normally contains a
267	>	* list of Nodes (most often, the list has only zero or one Node).
268	>	* Table accesses require volatile/atomic reads, writes, and
269	>	* CASes.  Because there is no other way to arrange this without
270	>	* adding further indirections, we use intrinsics
271	>	* (jdk.internal.misc.Unsafe) operations.
272	>	*
273	>	* We use the top (sign) bit of Node hash fields for control
274	>	* purposes -- it is available anyway because of addressing
275	>	* constraints.  Nodes with negative hash fields are specially
276	>	* handled or ignored in map methods.
277	>	*
278	>	* Insertion (via put or its variants) of the first node in an
279	>	* empty bin is performed by just CASing it to the bin.  This is
280	>	* by far the most common case for put operations under most
281	>	* key/hash distributions.  Other update operations (insert,
282	>	* delete, and replace) require locks.  We do not want to waste
283	>	* the space required to associate a distinct lock object with
284	>	* each bin, so instead use the first node of a bin list itself as
285	>	* a lock. Locking support for these locks relies on builtin
286	>	* "synchronized" monitors.
287	>	*
288	>	* Using the first node of a list as a lock does not by itself
289	>	* suffice though: When a node is locked, any update must first
290	>	* validate that it is still the first node after locking it, and
291	>	* retry if not. Because new nodes are always appended to lists,
292	>	* once a node is first in a bin, it remains first until deleted
293	>	* or the bin becomes invalidated (upon resizing).
294	>	*
295	>	* The main disadvantage of per-bin locks is that other update
296	>	* operations on other nodes in a bin list protected by the same
297	>	* lock can stall, for example when user equals() or mapping
298	>	* functions take a long time.  However, statistically, under
299	>	* random hash codes, this is not a common problem.  Ideally, the
300	>	* frequency of nodes in bins follows a Poisson distribution
301	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
302	>	* parameter of about 0.5 on average, given the resizing threshold
303	>	* of 0.75, although with a large variance because of resizing
304	>	* granularity. Ignoring variance, the expected occurrences of
305	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
306	>	* first values are:
307	>	*
308	>	* 0:    0.60653066
309	>	* 1:    0.30326533
310	>	* 2:    0.07581633
311	>	* 3:    0.01263606
312	>	* 4:    0.00157952
313	>	* 5:    0.00015795
314	>	* 6:    0.00001316
315	>	* 7:    0.00000094
316	>	* 8:    0.00000006
317	>	* more: less than 1 in ten million
318	>	*
319	>	* Lock contention probability for two threads accessing distinct
320	>	* elements is roughly 1 / (8 * #elements) under random hashes.
321	>	*
322	>	* Actual hash code distributions encountered in practice
323	>	* sometimes deviate significantly from uniform randomness.  This
324	>	* includes the case when N > (1<<30), so some keys MUST collide.
325	>	* Similarly for dumb or hostile usages in which multiple keys are
326	>	* designed to have identical hash codes or ones that differs only
327	>	* in masked-out high bits. So we use a secondary strategy that
328	>	* applies when the number of nodes in a bin exceeds a
329	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
330	>	* specialized form of red-black trees), bounding search time to
331	>	* O(log N).  Each search step in a TreeBin is at least twice as
332	>	* slow as in a regular list, but given that N cannot exceed
333	>	* (1<<64) (before running out of addresses) this bounds search
334	>	* steps, lock hold times, etc, to reasonable constants (roughly
335	>	* 100 nodes inspected per operation worst case) so long as keys
336	>	* are Comparable (which is very common -- String, Long, etc).
337	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
338	>	* traversal pointers as regular nodes, so can be traversed in
339	>	* iterators in the same way.
340	>	*
341	>	* The table is resized when occupancy exceeds a percentage
342	>	* threshold (nominally, 0.75, but see below).  Any thread
343	>	* noticing an overfull bin may assist in resizing after the
344	>	* initiating thread allocates and sets up the replacement array.
345	>	* However, rather than stalling, these other threads may proceed
346	>	* with insertions etc.  The use of TreeBins shields us from the
347	>	* worst case effects of overfilling while resizes are in
348	>	* progress.  Resizing proceeds by transferring bins, one by one,
349	>	* from the table to the next table. However, threads claim small
350	>	* blocks of indices to transfer (via field transferIndex) before
351	>	* doing so, reducing contention.  A generation stamp in field
352	>	* sizeCtl ensures that resizings do not overlap. Because we are
353	>	* using power-of-two expansion, the elements from each bin must
354	>	* either stay at same index, or move with a power of two
355	>	* offset. We eliminate unnecessary node creation by catching
356	>	* cases where old nodes can be reused because their next fields
357	>	* won't change.  On average, only about one-sixth of them need
358	>	* cloning when a table doubles. The nodes they replace will be
359	>	* garbage collectable as soon as they are no longer referenced by
360	>	* any reader thread that may be in the midst of concurrently
361	>	* traversing table.  Upon transfer, the old table bin contains
362	>	* only a special forwarding node (with hash field "MOVED") that
363	>	* contains the next table as its key. On encountering a
364	>	* forwarding node, access and update operations restart, using
365	>	* the new table.
366	>	*
367	>	* Each bin transfer requires its bin lock, which can stall
368	>	* waiting for locks while resizing. However, because other
369	>	* threads can join in and help resize rather than contend for
370	>	* locks, average aggregate waits become shorter as resizing
371	>	* progresses.  The transfer operation must also ensure that all
372	>	* accessible bins in both the old and new table are usable by any
373	>	* traversal.  This is arranged in part by proceeding from the
374	>	* last bin (table.length - 1) up towards the first.  Upon seeing
375	>	* a forwarding node, traversals (see class Traverser) arrange to
376	>	* move to the new table without revisiting nodes.  To ensure that
377	>	* no intervening nodes are skipped even when moved out of order,
378	>	* a stack (see class TableStack) is created on first encounter of
379	>	* a forwarding node during a traversal, to maintain its place if
380	>	* later processing the current table. The need for these
381	>	* save/restore mechanics is relatively rare, but when one
382	>	* forwarding node is encountered, typically many more will be.
383	>	* So Traversers use a simple caching scheme to avoid creating so
384	>	* many new TableStack nodes. (Thanks to Peter Levart for
385	>	* suggesting use of a stack here.)
386	>	*
387	>	* The traversal scheme also applies to partial traversals of
388	>	* ranges of bins (via an alternate Traverser constructor)
389	>	* to support partitioned aggregate operations.  Also, read-only
390	>	* operations give up if ever forwarded to a null table, which
391	>	* provides support for shutdown-style clearing, which is also not
392	>	* currently implemented.
393	>	*
394	>	* Lazy table initialization minimizes footprint until first use,
395	>	* and also avoids resizings when the first operation is from a
396	>	* putAll, constructor with map argument, or deserialization.
397	>	* These cases attempt to override the initial capacity settings,
398	>	* but harmlessly fail to take effect in cases of races.
399	>	*
400	>	* The element count is maintained using a specialization of
401	>	* LongAdder. We need to incorporate a specialization rather than
402	>	* just use a LongAdder in order to access implicit
403	>	* contention-sensing that leads to creation of multiple
404	>	* CounterCells.  The counter mechanics avoid contention on
405	>	* updates but can encounter cache thrashing if read too
406	>	* frequently during concurrent access. To avoid reading so often,
407	>	* resizing under contention is attempted only upon adding to a
408	>	* bin already holding two or more nodes. Under uniform hash
409	>	* distributions, the probability of this occurring at threshold
410	>	* is around 13%, meaning that only about 1 in 8 puts check
411	>	* threshold (and after resizing, many fewer do so).
412	>	*
413	>	* TreeBins use a special form of comparison for search and
414	>	* related operations (which is the main reason we cannot use
415	>	* existing collections such as TreeMaps). TreeBins contain
416	>	* Comparable elements, but may contain others, as well as
417	>	* elements that are Comparable but not necessarily Comparable for
418	>	* the same T, so we cannot invoke compareTo among them. To handle
419	>	* this, the tree is ordered primarily by hash value, then by
420	>	* Comparable.compareTo order if applicable.  On lookup at a node,
421	>	* if elements are not comparable or compare as 0 then both left
422	>	* and right children may need to be searched in the case of tied
423	>	* hash values. (This corresponds to the full list search that
424	>	* would be necessary if all elements were non-Comparable and had
425	>	* tied hashes.) On insertion, to keep a total ordering (or as
426	>	* close as is required here) across rebalancings, we compare
427	>	* classes and identityHashCodes as tie-breakers. The red-black
428	>	* balancing code is updated from pre-jdk-collections
429	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
430	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
431	>	* Algorithms" (CLR).
432	>	*
433	>	* TreeBins also require an additional locking mechanism.  While
434	>	* list traversal is always possible by readers even during
435	>	* updates, tree traversal is not, mainly because of tree-rotations
436	>	* that may change the root node and/or its linkages.  TreeBins
437	>	* include a simple read-write lock mechanism parasitic on the
438	>	* main bin-synchronization strategy: Structural adjustments
439	>	* associated with an insertion or removal are already bin-locked
440	>	* (and so cannot conflict with other writers) but must wait for
441	>	* ongoing readers to finish. Since there can be only one such
442	>	* waiter, we use a simple scheme using a single "waiter" field to
443	>	* block writers.  However, readers need never block.  If the root
444	>	* lock is held, they proceed along the slow traversal path (via
445	>	* next-pointers) until the lock becomes available or the list is
446	>	* exhausted, whichever comes first. These cases are not fast, but
447	>	* maximize aggregate expected throughput.
448	>	*
449	>	* Maintaining API and serialization compatibility with previous
450	>	* versions of this class introduces several oddities. Mainly: We
451	>	* leave untouched but unused constructor arguments referring to
452	>	* concurrencyLevel. We accept a loadFactor constructor argument,
453	>	* but apply it only to initial table capacity (which is the only
454	>	* time that we can guarantee to honor it.) We also declare an
455	>	* unused "Segment" class that is instantiated in minimal form
456	>	* only when serializing.
457	>	*
458	>	* Also, solely for compatibility with previous versions of this
459	>	* class, it extends AbstractMap, even though all of its methods
460	>	* are overridden, so it is just useless baggage.
461	>	*
462	>	* This file is organized to make things a little easier to follow
463	>	* while reading than they might otherwise: First the main static
464	>	* declarations and utilities, then fields, then main public
465	>	* methods (with a few factorings of multiple public methods into
466	>	* internal ones), then sizing methods, trees, traversers, and
467	>	* bulk operations.
468		*/
469
470		/* ---------------- Constants -------------- */
471
472		/**
473	<	* The default initial capacity for this table,
474	<	* used when not otherwise specified in a constructor.
473	>	* The largest possible table capacity.  This value must be
474	>	* exactly 1<<30 to stay within Java array allocation and indexing
475	>	* bounds for power of two table sizes, and is further required
476	>	* because the top two bits of 32bit hash fields are used for
477	>	* control purposes.
478		*/
479	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
479	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
480
481		/**
482	<	* The default load factor for this table, used when not
483	<	* otherwise specified in a constructor.
482	>	* The default initial table capacity.  Must be a power of 2
483	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
484		*/
485	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
485	>	private static final int DEFAULT_CAPACITY = 16;
486
487		/**
488	<	* The default concurrency level for this table, used when not
489	<	* otherwise specified in a constructor.
488	>	* The largest possible (non-power of two) array size.
489	>	* Needed by toArray and related methods.
490		*/
491	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
491	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
492
493		/**
494	<	* The maximum capacity, used if a higher value is implicitly
495	<	* specified by either of the constructors with arguments.  MUST
123	<	* be a power of two <= 1<<30 to ensure that entries are indexable
124	<	* using ints.
494	>	* The default concurrency level for this table. Unused but
495	>	* defined for compatibility with previous versions of this class.
496		*/
497	<	static final int MAXIMUM_CAPACITY = 1 << 30;
497	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
498
499		/**
500	<	* The minimum capacity for per-segment tables.  Must be a power
501	<	* of two, at least two to avoid immediate resizing on next use
502	<	* after lazy construction.
500	>	* The load factor for this table. Overrides of this value in
501	>	* constructors affect only the initial table capacity.  The
502	>	* actual floating point value isn't normally used -- it is
503	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
504	>	* the associated resizing threshold.
505		*/
506	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
506	>	private static final float LOAD_FACTOR = 0.75f;
507
508		/**
509	<	* The maximum number of segments to allow; used to bound
510	<	* constructor arguments. Must be power of two less than 1 << 24.
509	>	* The bin count threshold for using a tree rather than list for a
510	>	* bin.  Bins are converted to trees when adding an element to a
511	>	* bin with at least this many nodes. The value must be greater
512	>	* than 2, and should be at least 8 to mesh with assumptions in
513	>	* tree removal about conversion back to plain bins upon
514	>	* shrinkage.
515		*/
516	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
516	>	static final int TREEIFY_THRESHOLD = 8;
517
518		/**
519	<	* Number of unsynchronized retries in size and containsValue
520	<	* methods before resorting to locking. This is used to avoid
521	<	* unbounded retries if tables undergo continuous modification
145	<	* which would make it impossible to obtain an accurate result.
519	>	* The bin count threshold for untreeifying a (split) bin during a
520	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
521	>	* most 6 to mesh with shrinkage detection under removal.
522		*/
523	<	static final int RETRIES_BEFORE_LOCK = 2;
148	<
149	<	/* ---------------- Fields -------------- */
523	>	static final int UNTREEIFY_THRESHOLD = 6;
524
525		/**
526	<	* Mask value for indexing into segments. The upper bits of a
527	<	* key's hash code are used to choose the segment.
526	>	* The smallest table capacity for which bins may be treeified.
527	>	* (Otherwise the table is resized if too many nodes in a bin.)
528	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
529	>	* conflicts between resizing and treeification thresholds.
530		*/
531	<	final int segmentMask;
531	>	static final int MIN_TREEIFY_CAPACITY = 64;
532
533		/**
534	<	* Shift value for indexing within segments.
534	>	* Minimum number of rebinnings per transfer step. Ranges are
535	>	* subdivided to allow multiple resizer threads.  This value
536	>	* serves as a lower bound to avoid resizers encountering
537	>	* excessive memory contention.  The value should be at least
538	>	* DEFAULT_CAPACITY.
539		*/
540	<	final int segmentShift;
540	>	private static final int MIN_TRANSFER_STRIDE = 16;
541
542		/**
543	<	* The segments, each of which is a specialized hash table.
543	>	* The number of bits used for generation stamp in sizeCtl.
544	>	* Must be at least 6 for 32bit arrays.
545		*/
546	<	final Segment<K,V>[] segments;
546	>	private static final int RESIZE_STAMP_BITS = 16;
547
548	<	transient Set<K> keySet;
549	<	transient Set<Map.Entry<K,V>> entrySet;
550	<	transient Collection<V> values;
548	>	/**
549	>	* The maximum number of threads that can help resize.
550	>	* Must fit in 32 - RESIZE_STAMP_BITS bits.
551	>	*/
552	>	private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
553
554		/**
555	<	* ConcurrentHashMap list entry. Note that this is never exported
556	<	* out as a user-visible Map.Entry.
555	>	* The bit shift for recording size stamp in sizeCtl.
556	>	*/
557	>	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
558	>
559	>	/*
560	>	* Encodings for Node hash fields. See above for explanation.
561	>	*/
562	>	static final int MOVED     = -1; // hash for forwarding nodes
563	>	static final int TREEBIN   = -2; // hash for roots of trees
564	>	static final int RESERVED  = -3; // hash for transient reservations
565	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
566	>
567	>	/** Number of CPUS, to place bounds on some sizings */
568	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
569	>
570	>	/**
571	>	* Serialized pseudo-fields, provided only for jdk7 compatibility.
572	>	* @serialField segments Segment[]
573	>	*   The segments, each of which is a specialized hash table.
574	>	* @serialField segmentMask int
575	>	*   Mask value for indexing into segments. The upper bits of a
576	>	*   key's hash code are used to choose the segment.
577	>	* @serialField segmentShift int
578	>	*   Shift value for indexing within segments.
579	>	*/
580	>	private static final ObjectStreamField[] serialPersistentFields = {
581	>	new ObjectStreamField("segments", Segment[].class),
582	>	new ObjectStreamField("segmentMask", Integer.TYPE),
583	>	new ObjectStreamField("segmentShift", Integer.TYPE),
584	>	};
585	>
586	>	/* ---------------- Nodes -------------- */
587	>
588	>	/**
589	>	* Key-value entry.  This class is never exported out as a
590	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
591	>	* MapEntry below), but can be used for read-only traversals used
592	>	* in bulk tasks.  Subclasses of Node with a negative hash field
593	>	* are special, and contain null keys and values (but are never
594	>	* exported).  Otherwise, keys and vals are never null.
595		*/
596	<	static final class HashEntry<K,V> {
596	>	static class Node<K,V> implements Map.Entry<K,V> {
597		final int hash;
598		final K key;
599	<	volatile V value;
600	<	volatile HashEntry<K,V> next;
599	>	volatile V val;
600	>	volatile Node<K,V> next;
601
602	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
602	>	Node(int hash, K key, V val) {
603		this.hash = hash;
604		this.key = key;
605	<	this.value = value;
605	>	this.val = val;
606	>	}
607	>
608	>	Node(int hash, K key, V val, Node<K,V> next) {
609	>	this(hash, key, val);
610		this.next = next;
611		}
612
613	+	public final K getKey()     { return key; }
614	+	public final V getValue()   { return val; }
615	+	public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
616	+	public final String toString() {
617	+	return Helpers.mapEntryToString(key, val);
618	+	}
619	+	public final V setValue(V value) {
620	+	throw new UnsupportedOperationException();
621	+	}
622	+
623	+	public final boolean equals(Object o) {
624	+	Object k, v, u; Map.Entry<?,?> e;
625	+	return ((o instanceof Map.Entry) &&
626	+	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
627	+	(v = e.getValue()) != null &&
628	+	(k == key || k.equals(key)) &&
629	+	(v == (u = val) || v.equals(u)));
630	+	}
631	+
632		/**
633	<	* Sets next field with volatile write semantics.  (See above
190	<	* about use of putOrderedObject.)
633	>	* Virtualized support for map.get(); overridden in subclasses.
634		*/
635	<	final void setNext(HashEntry<K,V> n) {
636	<	UNSAFE.putOrderedObject(this, nextOffset, n);
635	>	Node<K,V> find(int h, Object k) {
636	>	Node<K,V> e = this;
637	>	if (k != null) {
638	>	do {
639	>	K ek;
640	>	if (e.hash == h &&
641	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
642	>	return e;
643	>	} while ((e = e.next) != null);
644	>	}
645	>	return null;
646		}
647	+	}
648
649	<	// Unsafe mechanics
650	<	static final sun.misc.Unsafe UNSAFE;
651	<	static final long nextOffset;
652	<	static {
653	<	try {
654	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
655	<	Class<?> k = HashEntry.class;
656	<	nextOffset = UNSAFE.objectFieldOffset
657	<	(k.getDeclaredField("next"));
658	<	} catch (Exception e) {
659	<	throw new Error(e);
649	>	/* ---------------- Static utilities -------------- */
650	>
651	>	/**
652	>	* Spreads (XORs) higher bits of hash to lower and also forces top
653	>	* bit to 0. Because the table uses power-of-two masking, sets of
654	>	* hashes that vary only in bits above the current mask will
655	>	* always collide. (Among known examples are sets of Float keys
656	>	* holding consecutive whole numbers in small tables.)  So we
657	>	* apply a transform that spreads the impact of higher bits
658	>	* downward. There is a tradeoff between speed, utility, and
659	>	* quality of bit-spreading. Because many common sets of hashes
660	>	* are already reasonably distributed (so don't benefit from
661	>	* spreading), and because we use trees to handle large sets of
662	>	* collisions in bins, we just XOR some shifted bits in the
663	>	* cheapest possible way to reduce systematic lossage, as well as
664	>	* to incorporate impact of the highest bits that would otherwise
665	>	* never be used in index calculations because of table bounds.
666	>	*/
667	>	static final int spread(int h) {
668	>	return (h ^ (h >>> 16)) & HASH_BITS;
669	>	}
670	>
671	>	/**
672	>	* Returns a power of two table size for the given desired capacity.
673	>	* See Hackers Delight, sec 3.2
674	>	*/
675	>	private static final int tableSizeFor(int c) {
676	>	int n = c - 1;
677	>	n |= n >>> 1;
678	>	n |= n >>> 2;
679	>	n |= n >>> 4;
680	>	n |= n >>> 8;
681	>	n |= n >>> 16;
682	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
683	>	}
684	>
685	>	/**
686	>	* Returns x's Class if it is of the form "class C implements
687	>	* Comparable<C>", else null.
688	>	*/
689	>	static Class<?> comparableClassFor(Object x) {
690	>	if (x instanceof Comparable) {
691	>	Class<?> c; Type[] ts, as; ParameterizedType p;
692	>	if ((c = x.getClass()) == String.class) // bypass checks
693	>	return c;
694	>	if ((ts = c.getGenericInterfaces()) != null) {
695	>	for (Type t : ts) {
696	>	if ((t instanceof ParameterizedType) &&
697	>	((p = (ParameterizedType)t).getRawType() ==
698	>	Comparable.class) &&
699	>	(as = p.getActualTypeArguments()) != null &&
700	>	as.length == 1 && as[0] == c) // type arg is c
701	>	return c;
702	>	}
703		}
704		}
705	+	return null;
706		}
707
708		/**
709	<	* Gets the ith element of given table (if nonnull) with volatile
710	<	* read semantics. Note: This is manually integrated into a few
711	<	* performance-sensitive methods to reduce call overhead.
709	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
710	>	* class), else 0.
711	>	*/
712	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
713	>	static int compareComparables(Class<?> kc, Object k, Object x) {
714	>	return (x == null || x.getClass() != kc ? 0 :
715	>	((Comparable)k).compareTo(x));
716	>	}
717	>
718	>	/* ---------------- Table element access -------------- */
719	>
720	>	/*
721	>	* Atomic access methods are used for table elements as well as
722	>	* elements of in-progress next table while resizing.  All uses of
723	>	* the tab arguments must be null checked by callers.  All callers
724	>	* also paranoically precheck that tab's length is not zero (or an
725	>	* equivalent check), thus ensuring that any index argument taking
726	>	* the form of a hash value anded with (length - 1) is a valid
727	>	* index.  Note that, to be correct wrt arbitrary concurrency
728	>	* errors by users, these checks must operate on local variables,
729	>	* which accounts for some odd-looking inline assignments below.
730	>	* Note that calls to setTabAt always occur within locked regions,
731	>	* and so require only release ordering.
732		*/
733	+
734		@SuppressWarnings("unchecked")
735	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
736	<	return (tab == null) ? null :
737	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
738	<	(tab, ((long)i << TSHIFT) + TBASE);
735	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
736	>	return (Node<K,V>)U.getObjectAcquire(tab, ((long)i << ASHIFT) + ABASE);
737	>	}
738	>
739	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
740	>	Node<K,V> c, Node<K,V> v) {
741	>	return U.compareAndSetObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
742		}
743
744	+	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
745	+	U.putObjectRelease(tab, ((long)i << ASHIFT) + ABASE, v);
746	+	}
747	+
748	+	/* ---------------- Fields -------------- */
749	+
750	+	/**
751	+	* The array of bins. Lazily initialized upon first insertion.
752	+	* Size is always a power of two. Accessed directly by iterators.
753	+	*/
754	+	transient volatile Node<K,V>[] table;
755	+
756		/**
757	<	* Sets the ith element of given table, with volatile write
225	<	* semantics. (See above about use of putOrderedObject.)
757	>	* The next table to use; non-null only while resizing.
758		*/
759	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
760	<	HashEntry<K,V> e) {
761	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
759	>	private transient volatile Node<K,V>[] nextTable;
760	>
761	>	/**
762	>	* Base counter value, used mainly when there is no contention,
763	>	* but also as a fallback during table initialization
764	>	* races. Updated via CAS.
765	>	*/
766	>	private transient volatile long baseCount;
767	>
768	>	/**
769	>	* Table initialization and resizing control.  When negative, the
770	>	* table is being initialized or resized: -1 for initialization,
771	>	* else -(1 + the number of active resizing threads).  Otherwise,
772	>	* when table is null, holds the initial table size to use upon
773	>	* creation, or 0 for default. After initialization, holds the
774	>	* next element count value upon which to resize the table.
775	>	*/
776	>	private transient volatile int sizeCtl;
777	>
778	>	/**
779	>	* The next table index (plus one) to split while resizing.
780	>	*/
781	>	private transient volatile int transferIndex;
782	>
783	>	/**
784	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
785	>	*/
786	>	private transient volatile int cellsBusy;
787	>
788	>	/**
789	>	* Table of counter cells. When non-null, size is a power of 2.
790	>	*/
791	>	private transient volatile CounterCell[] counterCells;
792	>
793	>	// views
794	>	private transient KeySetView<K,V> keySet;
795	>	private transient ValuesView<K,V> values;
796	>	private transient EntrySetView<K,V> entrySet;
797	>
798	>
799	>	/* ---------------- Public operations -------------- */
800	>
801	>	/**
802	>	* Creates a new, empty map with the default initial table size (16).
803	>	*/
804	>	public ConcurrentHashMap() {
805		}
806
807		/**
808	<	* Applies a supplemental hash function to a given hashCode, which
809	<	* defends against poor quality hash functions.  This is critical
810	<	* because ConcurrentHashMap uses power-of-two length hash tables,
811	<	* that otherwise encounter collisions for hashCodes that do not
812	<	* differ in lower or upper bits.
808	>	* Creates a new, empty map with an initial table size
809	>	* accommodating the specified number of elements without the need
810	>	* to dynamically resize.
811	>	*
812	>	* @param initialCapacity The implementation performs internal
813	>	* sizing to accommodate this many elements.
814	>	* @throws IllegalArgumentException if the initial capacity of
815	>	* elements is negative
816		*/
817	<	private static int hash(int h) {
818	<	// Spread bits to regularize both segment and index locations,
819	<	// using variant of single-word Wang/Jenkins hash.
820	<	h += (h <<  15) ^ 0xffffcd7d;
821	<	h ^= (h >>> 10);
822	<	h += (h <<   3);
823	<	h ^= (h >>>  6);
246	<	h += (h <<   2) + (h << 14);
247	<	return h ^ (h >>> 16);
817	>	public ConcurrentHashMap(int initialCapacity) {
818	>	if (initialCapacity < 0)
819	>	throw new IllegalArgumentException();
820	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
821	>	MAXIMUM_CAPACITY :
822	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
823	>	this.sizeCtl = cap;
824		}
825
826		/**
827	<	* Segments are specialized versions of hash tables.  This
828	<	* subclasses from ReentrantLock opportunistically, just to
829	<	* simplify some locking and avoid separate construction.
827	>	* Creates a new map with the same mappings as the given map.
828	>	*
829	>	* @param m the map
830		*/
831	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
832	<	/*
833	<	* Segments maintain a table of entry lists that are always
834	<	* kept in a consistent state, so can be read (via volatile
259	<	* reads of segments and tables) without locking.  This
260	<	* requires replicating nodes when necessary during table
261	<	* resizing, so the old lists can be traversed by readers
262	<	* still using old version of table.
263	<	*
264	<	* This class defines only mutative methods requiring locking.
265	<	* Except as noted, the methods of this class perform the
266	<	* per-segment versions of ConcurrentHashMap methods.  (Other
267	<	* methods are integrated directly into ConcurrentHashMap
268	<	* methods.) These mutative methods use a form of controlled
269	<	* spinning on contention via methods scanAndLock and
270	<	* scanAndLockForPut. These intersperse tryLocks with
271	<	* traversals to locate nodes.  The main benefit is to absorb
272	<	* cache misses (which are very common for hash tables) while
273	<	* obtaining locks so that traversal is faster once
274	<	* acquired. We do not actually use the found nodes since they
275	<	* must be re-acquired under lock anyway to ensure sequential
276	<	* consistency of updates (and in any case may be undetectably
277	<	* stale), but they will normally be much faster to re-locate.
278	<	* Also, scanAndLockForPut speculatively creates a fresh node
279	<	* to use in put if no node is found.
280	<	*/
831	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
832	>	this.sizeCtl = DEFAULT_CAPACITY;
833	>	putAll(m);
834	>	}
835
836	<	private static final long serialVersionUID = 2249069246763182397L;
836	>	/**
837	>	* Creates a new, empty map with an initial table size based on
838	>	* the given number of elements ({@code initialCapacity}) and
839	>	* initial table density ({@code loadFactor}).
840	>	*
841	>	* @param initialCapacity the initial capacity. The implementation
842	>	* performs internal sizing to accommodate this many elements,
843	>	* given the specified load factor.
844	>	* @param loadFactor the load factor (table density) for
845	>	* establishing the initial table size
846	>	* @throws IllegalArgumentException if the initial capacity of
847	>	* elements is negative or the load factor is nonpositive
848	>	*
849	>	* @since 1.6
850	>	*/
851	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
852	>	this(initialCapacity, loadFactor, 1);
853	>	}
854
855	<	/**
856	<	* The maximum number of times to tryLock in a prescan before
857	<	* possibly blocking on acquire in preparation for a locked
858	<	* segment operation. On multiprocessors, using a bounded
859	<	* number of retries maintains cache acquired while locating
860	<	* nodes.
861	<	*/
862	<	static final int MAX_SCAN_RETRIES =
863	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
855	>	/**
856	>	* Creates a new, empty map with an initial table size based on
857	>	* the given number of elements ({@code initialCapacity}), table
858	>	* density ({@code loadFactor}), and number of concurrently
859	>	* updating threads ({@code concurrencyLevel}).
860	>	*
861	>	* @param initialCapacity the initial capacity. The implementation
862	>	* performs internal sizing to accommodate this many elements,
863	>	* given the specified load factor.
864	>	* @param loadFactor the load factor (table density) for
865	>	* establishing the initial table size
866	>	* @param concurrencyLevel the estimated number of concurrently
867	>	* updating threads. The implementation may use this value as
868	>	* a sizing hint.
869	>	* @throws IllegalArgumentException if the initial capacity is
870	>	* negative or the load factor or concurrencyLevel are
871	>	* nonpositive
872	>	*/
873	>	public ConcurrentHashMap(int initialCapacity,
874	>	float loadFactor, int concurrencyLevel) {
875	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
876	>	throw new IllegalArgumentException();
877	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
878	>	initialCapacity = concurrencyLevel;   // as estimated threads
879	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
880	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
881	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
882	>	this.sizeCtl = cap;
883	>	}
884
885	<	/**
295	<	* The per-segment table. Elements are accessed via
296	<	* entryAt/setEntryAt providing volatile semantics.
297	<	*/
298	<	transient volatile HashEntry<K,V>[] table;
885	>	// Original (since JDK1.2) Map methods
886
887	<	/**
888	<	* The number of elements. Accessed only either within locks
889	<	* or among other volatile reads that maintain visibility.
890	<	*/
891	<	transient int count;
887	>	/**
888	>	* {@inheritDoc}
889	>	*/
890	>	public int size() {
891	>	long n = sumCount();
892	>	return ((n < 0L) ? 0 :
893	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
894	>	(int)n);
895	>	}
896
897	<	/**
898	<	* The total number of mutative operations in this segment.
899	<	* Even though this may overflows 32 bits, it provides
900	<	* sufficient accuracy for stability checks in CHM isEmpty()
901	<	* and size() methods.  Accessed only either within locks or
902	<	* among other volatile reads that maintain visibility.
312	<	*/
313	<	transient int modCount;
897	>	/**
898	>	* {@inheritDoc}
899	>	*/
900	>	public boolean isEmpty() {
901	>	return sumCount() <= 0L; // ignore transient negative values
902	>	}
903
904	<	/**
905	<	* The table is rehashed when its size exceeds this threshold.
906	<	* (The value of this field is always <tt>(int)(capacity *
907	<	* loadFactor)</tt>.)
908	<	*/
909	<	transient int threshold;
904	>	/**
905	>	* Returns the value to which the specified key is mapped,
906	>	* or {@code null} if this map contains no mapping for the key.
907	>	*
908	>	* <p>More formally, if this map contains a mapping from a key
909	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
910	>	* then this method returns {@code v}; otherwise it returns
911	>	* {@code null}.  (There can be at most one such mapping.)
912	>	*
913	>	* @throws NullPointerException if the specified key is null
914	>	*/
915	>	public V get(Object key) {
916	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
917	>	int h = spread(key.hashCode());
918	>	if ((tab = table) != null && (n = tab.length) > 0 &&
919	>	(e = tabAt(tab, (n - 1) & h)) != null) {
920	>	if ((eh = e.hash) == h) {
921	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
922	>	return e.val;
923	>	}
924	>	else if (eh < 0)
925	>	return (p = e.find(h, key)) != null ? p.val : null;
926	>	while ((e = e.next) != null) {
927	>	if (e.hash == h &&
928	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
929	>	return e.val;
930	>	}
931	>	}
932	>	return null;
933	>	}
934
935	<	/**
936	<	* The load factor for the hash table.  Even though this value
937	<	* is same for all segments, it is replicated to avoid needing
938	<	* links to outer object.
939	<	* @serial
940	<	*/
941	<	final float loadFactor;
935	>	/**
936	>	* Tests if the specified object is a key in this table.
937	>	*
938	>	* @param  key possible key
939	>	* @return {@code true} if and only if the specified object
940	>	*         is a key in this table, as determined by the
941	>	*         {@code equals} method; {@code false} otherwise
942	>	* @throws NullPointerException if the specified key is null
943	>	*/
944	>	public boolean containsKey(Object key) {
945	>	return get(key) != null;
946	>	}
947
948	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
949	<	this.loadFactor = lf;
950	<	this.threshold = threshold;
951	<	this.table = tab;
948	>	/**
949	>	* Returns {@code true} if this map maps one or more keys to the
950	>	* specified value. Note: This method may require a full traversal
951	>	* of the map, and is much slower than method {@code containsKey}.
952	>	*
953	>	* @param value value whose presence in this map is to be tested
954	>	* @return {@code true} if this map maps one or more keys to the
955	>	*         specified value
956	>	* @throws NullPointerException if the specified value is null
957	>	*/
958	>	public boolean containsValue(Object value) {
959	>	if (value == null)
960	>	throw new NullPointerException();
961	>	Node<K,V>[] t;
962	>	if ((t = table) != null) {
963	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
964	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
965	>	V v;
966	>	if ((v = p.val) == value || (v != null && value.equals(v)))
967	>	return true;
968	>	}
969		}
970	+	return false;
971	+	}
972
973	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
974	<	HashEntry<K,V> node = tryLock() ? null :
975	<	scanAndLockForPut(key, hash, value);
976	<	V oldValue;
977	<	try {
978	<	HashEntry<K,V>[] tab = table;
979	<	int index = (tab.length - 1) & hash;
980	<	HashEntry<K,V> first = entryAt(tab, index);
981	<	for (HashEntry<K,V> e = first;;) {
982	<	if (e != null) {
983	<	K k;
984	<	if ((k = e.key) == key ||
985	<	(e.hash == hash && key.equals(k))) {
986	<	oldValue = e.value;
987	<	if (!onlyIfAbsent) {
988	<	e.value = value;
989	<	++modCount;
973	>	/**
974	>	* Maps the specified key to the specified value in this table.
975	>	* Neither the key nor the value can be null.
976	>	*
977	>	* <p>The value can be retrieved by calling the {@code get} method
978	>	* with a key that is equal to the original key.
979	>	*
980	>	* @param key key with which the specified value is to be associated
981	>	* @param value value to be associated with the specified key
982	>	* @return the previous value associated with {@code key}, or
983	>	*         {@code null} if there was no mapping for {@code key}
984	>	* @throws NullPointerException if the specified key or value is null
985	>	*/
986	>	public V put(K key, V value) {
987	>	return putVal(key, value, false);
988	>	}
989	>
990	>	/** Implementation for put and putIfAbsent */
991	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
992	>	if (key == null || value == null) throw new NullPointerException();
993	>	int hash = spread(key.hashCode());
994	>	int binCount = 0;
995	>	for (Node<K,V>[] tab = table;;) {
996	>	Node<K,V> f; int n, i, fh; K fk; V fv;
997	>	if (tab == null || (n = tab.length) == 0)
998	>	tab = initTable();
999	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1000	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
1001	>	break;                   // no lock when adding to empty bin
1002	>	}
1003	>	else if ((fh = f.hash) == MOVED)
1004	>	tab = helpTransfer(tab, f);
1005	>	else if (onlyIfAbsent // check first node without acquiring lock
1006	>	&& fh == hash
1007	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1008	>	&& (fv = f.val) != null)
1009	>	return fv;
1010	>	else {
1011	>	V oldVal = null;
1012	>	synchronized (f) {
1013	>	if (tabAt(tab, i) == f) {
1014	>	if (fh >= 0) {
1015	>	binCount = 1;
1016	>	for (Node<K,V> e = f;; ++binCount) {
1017	>	K ek;
1018	>	if (e.hash == hash &&
1019	>	((ek = e.key) == key ||
1020	>	(ek != null && key.equals(ek)))) {
1021	>	oldVal = e.val;
1022	>	if (!onlyIfAbsent)
1023	>	e.val = value;
1024	>	break;
1025	>	}
1026	>	Node<K,V> pred = e;
1027	>	if ((e = e.next) == null) {
1028	>	pred.next = new Node<K,V>(hash, key, value);
1029	>	break;
1030	>	}
1031		}
354	–	break;
1032		}
1033	<	e = e.next;
1034	<	}
1035	<	else {
1036	<	if (node != null)
1037	<	node.setNext(first);
1038	<	else
1039	<	node = new HashEntry<K,V>(hash, key, value, first);
1040	<	int c = count + 1;
1041	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
1042	<	rehash(node);
1043	<	else
1044	<	setEntryAt(tab, index, node);
368	<	++modCount;
369	<	count = c;
370	<	oldValue = null;
371	<	break;
372	<	}
373	<	}
374	<	} finally {
375	<	unlock();
376	<	}
377	<	return oldValue;
378	<	}
379	<
380	<	/**
381	<	* Doubles size of table and repacks entries, also adding the
382	<	* given node to new table
383	<	*/
384	<	@SuppressWarnings("unchecked")
385	<	private void rehash(HashEntry<K,V> node) {
386	<	/*
387	<	* Reclassify nodes in each list to new table.  Because we
388	<	* are using power-of-two expansion, the elements from
389	<	* each bin must either stay at same index, or move with a
390	<	* power of two offset. We eliminate unnecessary node
391	<	* creation by catching cases where old nodes can be
392	<	* reused because their next fields won't change.
393	<	* Statistically, at the default threshold, only about
394	<	* one-sixth of them need cloning when a table
395	<	* doubles. The nodes they replace will be garbage
396	<	* collectable as soon as they are no longer referenced by
397	<	* any reader thread that may be in the midst of
398	<	* concurrently traversing table. Entry accesses use plain
399	<	* array indexing because they are followed by volatile
400	<	* table write.
401	<	*/
402	<	HashEntry<K,V>[] oldTable = table;
403	<	int oldCapacity = oldTable.length;
404	<	int newCapacity = oldCapacity << 1;
405	<	threshold = (int)(newCapacity * loadFactor);
406	<	HashEntry<K,V>[] newTable =
407	<	(HashEntry<K,V>[]) new HashEntry<?,?>[newCapacity];
408	<	int sizeMask = newCapacity - 1;
409	<	for (int i = 0; i < oldCapacity ; i++) {
410	<	HashEntry<K,V> e = oldTable[i];
411	<	if (e != null) {
412	<	HashEntry<K,V> next = e.next;
413	<	int idx = e.hash & sizeMask;
414	<	if (next == null)   //  Single node on list
415	<	newTable[idx] = e;
416	<	else { // Reuse consecutive sequence at same slot
417	<	HashEntry<K,V> lastRun = e;
418	<	int lastIdx = idx;
419	<	for (HashEntry<K,V> last = next;
420	<	last != null;
421	<	last = last.next) {
422	<	int k = last.hash & sizeMask;
423	<	if (k != lastIdx) {
424	<	lastIdx = k;
425	<	lastRun = last;
426	<	}
427	<	}
428	<	newTable[lastIdx] = lastRun;
429	<	// Clone remaining nodes
430	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
431	<	V v = p.value;
432	<	int h = p.hash;
433	<	int k = h & sizeMask;
434	<	HashEntry<K,V> n = newTable[k];
435	<	newTable[k] = new HashEntry<K,V>(h, p.key, v, n);
436	<	}
437	<	}
438	<	}
439	<	}
440	<	int nodeIndex = node.hash & sizeMask; // add the new node
441	<	node.setNext(newTable[nodeIndex]);
442	<	newTable[nodeIndex] = node;
443	<	table = newTable;
444	<	}
445	<
446	<	/**
447	<	* Scans for a node containing given key while trying to
448	<	* acquire lock, creating and returning one if not found. Upon
449	<	* return, guarantees that lock is held. Unlike in most
450	<	* methods, calls to method equals are not screened: Since
451	<	* traversal speed doesn't matter, we might as well help warm
452	<	* up the associated code and accesses as well.
453	<	*
454	<	* @return a new node if key not found, else null
455	<	*/
456	<	private HashEntry<K,V> scanAndLockForPut(K key, int hash, V value) {
457	<	HashEntry<K,V> first = entryForHash(this, hash);
458	<	HashEntry<K,V> e = first;
459	<	HashEntry<K,V> node = null;
460	<	int retries = -1; // negative while locating node
461	<	while (!tryLock()) {
462	<	HashEntry<K,V> f; // to recheck first below
463	<	if (retries < 0) {
464	<	if (e == null) {
465	<	if (node == null) // speculatively create node
466	<	node = new HashEntry<K,V>(hash, key, value, null);
467	<	retries = 0;
1033	>	else if (f instanceof TreeBin) {
1034	>	Node<K,V> p;
1035	>	binCount = 2;
1036	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1037	>	value)) != null) {
1038	>	oldVal = p.val;
1039	>	if (!onlyIfAbsent)
1040	>	p.val = value;
1041	>	}
1042	>	}
1043	>	else if (f instanceof ReservationNode)
1044	>	throw new IllegalStateException("Recursive update");
1045		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
473	–	}
474	–	else if (++retries > MAX_SCAN_RETRIES) {
475	–	lock();
476	–	break;
477	–	}
478	–	else if ((retries & 1) == 0 &&
479	–	(f = entryForHash(this, hash)) != first) {
480	–	e = first = f; // re-traverse if entry changed
481	–	retries = -1;
482	–	}
483	–	}
484	–	return node;
485	–	}
486	–
487	–	/**
488	–	* Scans for a node containing the given key while trying to
489	–	* acquire lock for a remove or replace operation. Upon
490	–	* return, guarantees that lock is held.  Note that we must
491	–	* lock even if the key is not found, to ensure sequential
492	–	* consistency of updates.
493	–	*/
494	–	private void scanAndLock(Object key, int hash) {
495	–	// similar to but simpler than scanAndLockForPut
496	–	HashEntry<K,V> first = entryForHash(this, hash);
497	–	HashEntry<K,V> e = first;
498	–	int retries = -1;
499	–	while (!tryLock()) {
500	–	HashEntry<K,V> f;
501	–	if (retries < 0) {
502	–	if (e == null || key.equals(e.key))
503	–	retries = 0;
504	–	else
505	–	e = e.next;
1046		}
1047	<	else if (++retries > MAX_SCAN_RETRIES) {
1048	<	lock();
1047	>	if (binCount != 0) {
1048	>	if (binCount >= TREEIFY_THRESHOLD)
1049	>	treeifyBin(tab, i);
1050	>	if (oldVal != null)
1051	>	return oldVal;
1052		break;
1053		}
511	–	else if ((retries & 1) == 0 &&
512	–	(f = entryForHash(this, hash)) != first) {
513	–	e = first = f;
514	–	retries = -1;
515	–	}
1054		}
1055		}
1056	+	addCount(1L, binCount);
1057	+	return null;
1058	+	}
1059
1060	<	/**
1061	<	* Remove; match on key only if value null, else match both.
1062	<	*/
1063	<	final V remove(Object key, int hash, Object value) {
1064	<	if (!tryLock())
1065	<	scanAndLock(key, hash);
1066	<	V oldValue = null;
1067	<	try {
1068	<	HashEntry<K,V>[] tab = table;
1069	<	int index = (tab.length - 1) & hash;
1070	<	HashEntry<K,V> e = entryAt(tab, index);
1071	<	HashEntry<K,V> pred = null;
1072	<	while (e != null) {
1073	<	K k;
1074	<	HashEntry<K,V> next = e.next;
1075	<	if ((k = e.key) == key ||
1076	<	(e.hash == hash && key.equals(k))) {
1077	<	V v = e.value;
1078	<	if (value == null || value == v || value.equals(v)) {
1079	<	if (pred == null)
1080	<	setEntryAt(tab, index, next);
1081	<	else
1082	<	pred.setNext(next);
1083	<	++modCount;
1084	<	--count;
1085	<	oldValue = v;
1060	>	/**
1061	>	* Copies all of the mappings from the specified map to this one.
1062	>	* These mappings replace any mappings that this map had for any of the
1063	>	* keys currently in the specified map.
1064	>	*
1065	>	* @param m mappings to be stored in this map
1066	>	*/
1067	>	public void putAll(Map<? extends K, ? extends V> m) {
1068	>	tryPresize(m.size());
1069	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1070	>	putVal(e.getKey(), e.getValue(), false);
1071	>	}
1072	>
1073	>	/**
1074	>	* Removes the key (and its corresponding value) from this map.
1075	>	* This method does nothing if the key is not in the map.
1076	>	*
1077	>	* @param  key the key that needs to be removed
1078	>	* @return the previous value associated with {@code key}, or
1079	>	*         {@code null} if there was no mapping for {@code key}
1080	>	* @throws NullPointerException if the specified key is null
1081	>	*/
1082	>	public V remove(Object key) {
1083	>	return replaceNode(key, null, null);
1084	>	}
1085	>
1086	>	/**
1087	>	* Implementation for the four public remove/replace methods:
1088	>	* Replaces node value with v, conditional upon match of cv if
1089	>	* non-null.  If resulting value is null, delete.
1090	>	*/
1091	>	final V replaceNode(Object key, V value, Object cv) {
1092	>	int hash = spread(key.hashCode());
1093	>	for (Node<K,V>[] tab = table;;) {
1094	>	Node<K,V> f; int n, i, fh;
1095	>	if (tab == null || (n = tab.length) == 0 ||
1096	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1097	>	break;
1098	>	else if ((fh = f.hash) == MOVED)
1099	>	tab = helpTransfer(tab, f);
1100	>	else {
1101	>	V oldVal = null;
1102	>	boolean validated = false;
1103	>	synchronized (f) {
1104	>	if (tabAt(tab, i) == f) {
1105	>	if (fh >= 0) {
1106	>	validated = true;
1107	>	for (Node<K,V> e = f, pred = null;;) {
1108	>	K ek;
1109	>	if (e.hash == hash &&
1110	>	((ek = e.key) == key ||
1111	>	(ek != null && key.equals(ek)))) {
1112	>	V ev = e.val;
1113	>	if (cv == null || cv == ev ||
1114	>	(ev != null && cv.equals(ev))) {
1115	>	oldVal = ev;
1116	>	if (value != null)
1117	>	e.val = value;
1118	>	else if (pred != null)
1119	>	pred.next = e.next;
1120	>	else
1121	>	setTabAt(tab, i, e.next);
1122	>	}
1123	>	break;
1124	>	}
1125	>	pred = e;
1126	>	if ((e = e.next) == null)
1127	>	break;
1128	>	}
1129		}
1130	<	break;
1130	>	else if (f instanceof TreeBin) {
1131	>	validated = true;
1132	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1133	>	TreeNode<K,V> r, p;
1134	>	if ((r = t.root) != null &&
1135	>	(p = r.findTreeNode(hash, key, null)) != null) {
1136	>	V pv = p.val;
1137	>	if (cv == null || cv == pv ||
1138	>	(pv != null && cv.equals(pv))) {
1139	>	oldVal = pv;
1140	>	if (value != null)
1141	>	p.val = value;
1142	>	else if (t.removeTreeNode(p))
1143	>	setTabAt(tab, i, untreeify(t.first));
1144	>	}
1145	>	}
1146	>	}
1147	>	else if (f instanceof ReservationNode)
1148	>	throw new IllegalStateException("Recursive update");
1149		}
548	–	pred = e;
549	–	e = next;
1150		}
1151	<	} finally {
1152	<	unlock();
1153	<	}
1154	<	return oldValue;
1155	<	}
556	<
557	<	final boolean replace(K key, int hash, V oldValue, V newValue) {
558	<	if (!tryLock())
559	<	scanAndLock(key, hash);
560	<	boolean replaced = false;
561	<	try {
562	<	HashEntry<K,V> e;
563	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
564	<	K k;
565	<	if ((k = e.key) == key ||
566	<	(e.hash == hash && key.equals(k))) {
567	<	if (oldValue.equals(e.value)) {
568	<	e.value = newValue;
569	<	++modCount;
570	<	replaced = true;
571	<	}
572	<	break;
1151	>	if (validated) {
1152	>	if (oldVal != null) {
1153	>	if (value == null)
1154	>	addCount(-1L, -1);
1155	>	return oldVal;
1156		}
1157	+	break;
1158		}
575	–	} finally {
576	–	unlock();
1159		}
578	–	return replaced;
1160		}
1161	+	return null;
1162	+	}
1163
1164	<	final V replace(K key, int hash, V value) {
1165	<	if (!tryLock())
1166	<	scanAndLock(key, hash);
1167	<	V oldValue = null;
1168	<	try {
1169	<	HashEntry<K,V> e;
1170	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1171	<	K k;
1172	<	if ((k = e.key) == key ||
1173	<	(e.hash == hash && key.equals(k))) {
1174	<	oldValue = e.value;
1175	<	e.value = value;
1176	<	++modCount;
1177	<	break;
1164	>	/**
1165	>	* Removes all of the mappings from this map.
1166	>	*/
1167	>	public void clear() {
1168	>	long delta = 0L; // negative number of deletions
1169	>	int i = 0;
1170	>	Node<K,V>[] tab = table;
1171	>	while (tab != null && i < tab.length) {
1172	>	int fh;
1173	>	Node<K,V> f = tabAt(tab, i);
1174	>	if (f == null)
1175	>	++i;
1176	>	else if ((fh = f.hash) == MOVED) {
1177	>	tab = helpTransfer(tab, f);
1178	>	i = 0; // restart
1179	>	}
1180	>	else {
1181	>	synchronized (f) {
1182	>	if (tabAt(tab, i) == f) {
1183	>	Node<K,V> p = (fh >= 0 ? f :
1184	>	(f instanceof TreeBin) ?
1185	>	((TreeBin<K,V>)f).first : null);
1186	>	while (p != null) {
1187	>	--delta;
1188	>	p = p.next;
1189	>	}
1190	>	setTabAt(tab, i++, null);
1191		}
1192		}
597	–	} finally {
598	–	unlock();
1193		}
600	–	return oldValue;
1194		}
1195	+	if (delta != 0L)
1196	+	addCount(delta, -1);
1197	+	}
1198
1199	<	final void clear() {
1200	<	lock();
1201	<	try {
1202	<	HashEntry<K,V>[] tab = table;
1203	<	for (int i = 0; i < tab.length ; i++)
1204	<	setEntryAt(tab, i, null);
1205	<	++modCount;
1206	<	count = 0;
1207	<	} finally {
1208	<	unlock();
1209	<	}
1210	<	}
1199	>	/**
1200	>	* Returns a {@link Set} view of the keys contained in this map.
1201	>	* The set is backed by the map, so changes to the map are
1202	>	* reflected in the set, and vice-versa. The set supports element
1203	>	* removal, which removes the corresponding mapping from this map,
1204	>	* via the {@code Iterator.remove}, {@code Set.remove},
1205	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1206	>	* operations.  It does not support the {@code add} or
1207	>	* {@code addAll} operations.
1208	>	*
1209	>	* <p>The view's iterators and spliterators are
1210	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1211	>	*
1212	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1213	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1214	>	*
1215	>	* @return the set view
1216	>	*/
1217	>	public KeySetView<K,V> keySet() {
1218	>	KeySetView<K,V> ks;
1219	>	if ((ks = keySet) != null) return ks;
1220	>	return keySet = new KeySetView<K,V>(this, null);
1221		}
1222
1223	<	// Accessing segments
1223	>	/**
1224	>	* Returns a {@link Collection} view of the values contained in this map.
1225	>	* The collection is backed by the map, so changes to the map are
1226	>	* reflected in the collection, and vice-versa.  The collection
1227	>	* supports element removal, which removes the corresponding
1228	>	* mapping from this map, via the {@code Iterator.remove},
1229	>	* {@code Collection.remove}, {@code removeAll},
1230	>	* {@code retainAll}, and {@code clear} operations.  It does not
1231	>	* support the {@code add} or {@code addAll} operations.
1232	>	*
1233	>	* <p>The view's iterators and spliterators are
1234	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1235	>	*
1236	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1237	>	* and {@link Spliterator#NONNULL}.
1238	>	*
1239	>	* @return the collection view
1240	>	*/
1241	>	public Collection<V> values() {
1242	>	ValuesView<K,V> vs;
1243	>	if ((vs = values) != null) return vs;
1244	>	return values = new ValuesView<K,V>(this);
1245	>	}
1246
1247		/**
1248	<	* Gets the jth element of given segment array (if nonnull) with
1249	<	* volatile element access semantics via Unsafe. (The null check
1250	<	* can trigger harmlessly only during deserialization.) Note:
1251	<	* because each element of segments array is set only once (using
1252	<	* fully ordered writes), some performance-sensitive methods rely
1253	<	* on this method only as a recheck upon null reads.
1248	>	* Returns a {@link Set} view of the mappings contained in this map.
1249	>	* The set is backed by the map, so changes to the map are
1250	>	* reflected in the set, and vice-versa.  The set supports element
1251	>	* removal, which removes the corresponding mapping from the map,
1252	>	* via the {@code Iterator.remove}, {@code Set.remove},
1253	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1254	>	* operations.
1255	>	*
1256	>	* <p>The view's iterators and spliterators are
1257	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1258	>	*
1259	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1260	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1261	>	*
1262	>	* @return the set view
1263		*/
1264	<	@SuppressWarnings("unchecked")
1265	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1266	<	long u = (j << SSHIFT) + SBASE;
1267	<	return ss == null ? null :
631	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1264	>	public Set<Map.Entry<K,V>> entrySet() {
1265	>	EntrySetView<K,V> es;
1266	>	if ((es = entrySet) != null) return es;
1267	>	return entrySet = new EntrySetView<K,V>(this);
1268		}
1269
1270		/**
1271	<	* Returns the segment for the given index, creating it and
1272	<	* recording in segment table (via CAS) if not already present.
1271	>	* Returns the hash code value for this {@link Map}, i.e.,
1272	>	* the sum of, for each key-value pair in the map,
1273	>	* {@code key.hashCode() ^ value.hashCode()}.
1274		*
1275	<	* @param k the index
639	<	* @return the segment
1275	>	* @return the hash code value for this map
1276		*/
1277	<	@SuppressWarnings("unchecked")
1278	<	private Segment<K,V> ensureSegment(int k) {
1279	<	final Segment<K,V>[] ss = this.segments;
1280	<	long u = (k << SSHIFT) + SBASE; // raw offset
1281	<	Segment<K,V> seg;
1282	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1283	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1284	<	int cap = proto.table.length;
1285	<	float lf = proto.loadFactor;
1286	<	int threshold = (int)(cap * lf);
1287	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry<?,?>[cap];
1288	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1289	<	== null) { // recheck
1290	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1291	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1292	<	== null) {
1293	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1294	<	break;
1295	<	}
1277	>	public int hashCode() {
1278	>	int h = 0;
1279	>	Node<K,V>[] t;
1280	>	if ((t = table) != null) {
1281	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1282	>	for (Node<K,V> p; (p = it.advance()) != null; )
1283	>	h += p.key.hashCode() ^ p.val.hashCode();
1284	>	}
1285	>	return h;
1286	>	}
1287	>
1288	>	/**
1289	>	* Returns a string representation of this map.  The string
1290	>	* representation consists of a list of key-value mappings (in no
1291	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1292	>	* mappings are separated by the characters {@code ", "} (comma
1293	>	* and space).  Each key-value mapping is rendered as the key
1294	>	* followed by an equals sign ("{@code =}") followed by the
1295	>	* associated value.
1296	>	*
1297	>	* @return a string representation of this map
1298	>	*/
1299	>	public String toString() {
1300	>	Node<K,V>[] t;
1301	>	int f = (t = table) == null ? 0 : t.length;
1302	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1303	>	StringBuilder sb = new StringBuilder();
1304	>	sb.append('{');
1305	>	Node<K,V> p;
1306	>	if ((p = it.advance()) != null) {
1307	>	for (;;) {
1308	>	K k = p.key;
1309	>	V v = p.val;
1310	>	sb.append(k == this ? "(this Map)" : k);
1311	>	sb.append('=');
1312	>	sb.append(v == this ? "(this Map)" : v);
1313	>	if ((p = it.advance()) == null)
1314	>	break;
1315	>	sb.append(',').append(' ');
1316		}
1317		}
1318	<	return seg;
1318	>	return sb.append('}').toString();
1319		}
1320
665	–	// Hash-based segment and entry accesses
666	–
1321		/**
1322	<	* Gets the segment for the given hash code.
1322	>	* Compares the specified object with this map for equality.
1323	>	* Returns {@code true} if the given object is a map with the same
1324	>	* mappings as this map.  This operation may return misleading
1325	>	* results if either map is concurrently modified during execution
1326	>	* of this method.
1327	>	*
1328	>	* @param o object to be compared for equality with this map
1329	>	* @return {@code true} if the specified object is equal to this map
1330		*/
1331	<	@SuppressWarnings("unchecked")
1332	<	private Segment<K,V> segmentForHash(int h) {
1333	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1334	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1331	>	public boolean equals(Object o) {
1332	>	if (o != this) {
1333	>	if (!(o instanceof Map))
1334	>	return false;
1335	>	Map<?,?> m = (Map<?,?>) o;
1336	>	Node<K,V>[] t;
1337	>	int f = (t = table) == null ? 0 : t.length;
1338	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1339	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1340	>	V val = p.val;
1341	>	Object v = m.get(p.key);
1342	>	if (v == null || (v != val && !v.equals(val)))
1343	>	return false;
1344	>	}
1345	>	for (Map.Entry<?,?> e : m.entrySet()) {
1346	>	Object mk, mv, v;
1347	>	if ((mk = e.getKey()) == null ||
1348	>	(mv = e.getValue()) == null ||
1349	>	(v = get(mk)) == null ||
1350	>	(mv != v && !mv.equals(v)))
1351	>	return false;
1352	>	}
1353	>	}
1354	>	return true;
1355		}
1356
1357		/**
1358	<	* Gets the table entry for the given segment and hash code.
1358	>	* Stripped-down version of helper class used in previous version,
1359	>	* declared for the sake of serialization compatibility.
1360		*/
1361	<	@SuppressWarnings("unchecked")
1362	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1363	<	HashEntry<K,V>[] tab;
1364	<	return (seg == null || (tab = seg.table) == null) ? null :
683	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
684	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1361	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1362	>	private static final long serialVersionUID = 2249069246763182397L;
1363	>	final float loadFactor;
1364	>	Segment(float lf) { this.loadFactor = lf; }
1365		}
1366
687	–	/* ---------------- Public operations -------------- */
688	–
1367		/**
1368	<	* Creates a new, empty map with the specified initial
691	<	* capacity, load factor and concurrency level.
1368	>	* Saves this map to a stream (that is, serializes it).
1369		*
1370	<	* @param initialCapacity the initial capacity. The implementation
1371	<	* performs internal sizing to accommodate this many elements.
1372	<	* @param loadFactor  the load factor threshold, used to control resizing.
1373	<	* Resizing may be performed when the average number of elements per
1374	<	* bin exceeds this threshold.
1375	<	* @param concurrencyLevel the estimated number of concurrently
699	<	* updating threads. The implementation performs internal sizing
700	<	* to try to accommodate this many threads.
701	<	* @throws IllegalArgumentException if the initial capacity is
702	<	* negative or the load factor or concurrencyLevel are
703	<	* nonpositive.
1370	>	* @param s the stream
1371	>	* @throws java.io.IOException if an I/O error occurs
1372	>	* @serialData
1373	>	* the serialized fields, followed by the key (Object) and value
1374	>	* (Object) for each key-value mapping, followed by a null pair.
1375	>	* The key-value mappings are emitted in no particular order.
1376		*/
1377	<	@SuppressWarnings("unchecked")
1378	<	public ConcurrentHashMap(int initialCapacity,
1379	<	float loadFactor, int concurrencyLevel) {
1380	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
709	<	throw new IllegalArgumentException();
710	<	if (concurrencyLevel > MAX_SEGMENTS)
711	<	concurrencyLevel = MAX_SEGMENTS;
712	<	// Find power-of-two sizes best matching arguments
1377	>	private void writeObject(java.io.ObjectOutputStream s)
1378	>	throws java.io.IOException {
1379	>	// For serialization compatibility
1380	>	// Emulate segment calculation from previous version of this class
1381		int sshift = 0;
1382		int ssize = 1;
1383	<	while (ssize < concurrencyLevel) {
1383	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1384		++sshift;
1385		ssize <<= 1;
1386		}
1387	<	this.segmentShift = 32 - sshift;
1388	<	this.segmentMask = ssize - 1;
1389	<	if (initialCapacity > MAXIMUM_CAPACITY)
1390	<	initialCapacity = MAXIMUM_CAPACITY;
1391	<	int c = initialCapacity / ssize;
1392	<	if (c * ssize < initialCapacity)
1393	<	++c;
1394	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1395	<	while (cap < c)
1396	<	cap <<= 1;
1397	<	// create segments and segments[0]
1398	<	Segment<K,V> s0 =
1399	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1400	<	(HashEntry<K,V>[])new HashEntry<?,?>[cap]);
1401	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment<?,?>[ssize];
1402	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1403	<	this.segments = ss;
1387	>	int segmentShift = 32 - sshift;
1388	>	int segmentMask = ssize - 1;
1389	>	@SuppressWarnings("unchecked")
1390	>	Segment<K,V>[] segments = (Segment<K,V>[])
1391	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1392	>	for (int i = 0; i < segments.length; ++i)
1393	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1394	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1395	>	streamFields.put("segments", segments);
1396	>	streamFields.put("segmentShift", segmentShift);
1397	>	streamFields.put("segmentMask", segmentMask);
1398	>	s.writeFields();
1399	>
1400	>	Node<K,V>[] t;
1401	>	if ((t = table) != null) {
1402	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1403	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1404	>	s.writeObject(p.key);
1405	>	s.writeObject(p.val);
1406	>	}
1407	>	}
1408	>	s.writeObject(null);
1409	>	s.writeObject(null);
1410		}
1411
1412		/**
1413	<	* Creates a new, empty map with the specified initial capacity
1414	<	* and load factor and with the default concurrencyLevel (16).
1415	<	*
1416	<	* @param initialCapacity The implementation performs internal
1417	<	* sizing to accommodate this many elements.
1418	<	* @param loadFactor  the load factor threshold, used to control resizing.
1419	<	* Resizing may be performed when the average number of elements per
1420	<	* bin exceeds this threshold.
1421	<	* @throws IllegalArgumentException if the initial capacity of
1422	<	* elements is negative or the load factor is nonpositive
1413	>	* Reconstitutes this map from a stream (that is, deserializes it).
1414	>	* @param s the stream
1415	>	* @throws ClassNotFoundException if the class of a serialized object
1416	>	*         could not be found
1417	>	* @throws java.io.IOException if an I/O error occurs
1418	>	*/
1419	>	private void readObject(java.io.ObjectInputStream s)
1420	>	throws java.io.IOException, ClassNotFoundException {
1421	>	/*
1422	>	* To improve performance in typical cases, we create nodes
1423	>	* while reading, then place in table once size is known.
1424	>	* However, we must also validate uniqueness and deal with
1425	>	* overpopulated bins while doing so, which requires
1426	>	* specialized versions of putVal mechanics.
1427	>	*/
1428	>	sizeCtl = -1; // force exclusion for table construction
1429	>	s.defaultReadObject();
1430	>	long size = 0L;
1431	>	Node<K,V> p = null;
1432	>	for (;;) {
1433	>	@SuppressWarnings("unchecked")
1434	>	K k = (K) s.readObject();
1435	>	@SuppressWarnings("unchecked")
1436	>	V v = (V) s.readObject();
1437	>	if (k != null && v != null) {
1438	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1439	>	++size;
1440	>	}
1441	>	else
1442	>	break;
1443	>	}
1444	>	if (size == 0L)
1445	>	sizeCtl = 0;
1446	>	else {
1447	>	int n;
1448	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1449	>	n = MAXIMUM_CAPACITY;
1450	>	else {
1451	>	int sz = (int)size;
1452	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1453	>	}
1454	>	@SuppressWarnings("unchecked")
1455	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1456	>	int mask = n - 1;
1457	>	long added = 0L;
1458	>	while (p != null) {
1459	>	boolean insertAtFront;
1460	>	Node<K,V> next = p.next, first;
1461	>	int h = p.hash, j = h & mask;
1462	>	if ((first = tabAt(tab, j)) == null)
1463	>	insertAtFront = true;
1464	>	else {
1465	>	K k = p.key;
1466	>	if (first.hash < 0) {
1467	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1468	>	if (t.putTreeVal(h, k, p.val) == null)
1469	>	++added;
1470	>	insertAtFront = false;
1471	>	}
1472	>	else {
1473	>	int binCount = 0;
1474	>	insertAtFront = true;
1475	>	Node<K,V> q; K qk;
1476	>	for (q = first; q != null; q = q.next) {
1477	>	if (q.hash == h &&
1478	>	((qk = q.key) == k ||
1479	>	(qk != null && k.equals(qk)))) {
1480	>	insertAtFront = false;
1481	>	break;
1482	>	}
1483	>	++binCount;
1484	>	}
1485	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1486	>	insertAtFront = false;
1487	>	++added;
1488	>	p.next = first;
1489	>	TreeNode<K,V> hd = null, tl = null;
1490	>	for (q = p; q != null; q = q.next) {
1491	>	TreeNode<K,V> t = new TreeNode<K,V>
1492	>	(q.hash, q.key, q.val, null, null);
1493	>	if ((t.prev = tl) == null)
1494	>	hd = t;
1495	>	else
1496	>	tl.next = t;
1497	>	tl = t;
1498	>	}
1499	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1500	>	}
1501	>	}
1502	>	}
1503	>	if (insertAtFront) {
1504	>	++added;
1505	>	p.next = first;
1506	>	setTabAt(tab, j, p);
1507	>	}
1508	>	p = next;
1509	>	}
1510	>	table = tab;
1511	>	sizeCtl = n - (n >>> 2);
1512	>	baseCount = added;
1513	>	}
1514	>	}
1515	>
1516	>	// ConcurrentMap methods
1517	>
1518	>	/**
1519	>	* {@inheritDoc}
1520		*
1521	<	* @since 1.6
1521	>	* @return the previous value associated with the specified key,
1522	>	*         or {@code null} if there was no mapping for the key
1523	>	* @throws NullPointerException if the specified key or value is null
1524		*/
1525	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
1526	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1525	>	public V putIfAbsent(K key, V value) {
1526	>	return putVal(key, value, true);
1527		}
1528
1529		/**
1530	<	* Creates a new, empty map with the specified initial capacity,
758	<	* and with default load factor (0.75) and concurrencyLevel (16).
1530	>	* {@inheritDoc}
1531		*
1532	<	* @param initialCapacity the initial capacity. The implementation
761	<	* performs internal sizing to accommodate this many elements.
762	<	* @throws IllegalArgumentException if the initial capacity of
763	<	* elements is negative.
1532	>	* @throws NullPointerException if the specified key is null
1533		*/
1534	<	public ConcurrentHashMap(int initialCapacity) {
1535	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1534	>	public boolean remove(Object key, Object value) {
1535	>	if (key == null)
1536	>	throw new NullPointerException();
1537	>	return value != null && replaceNode(key, null, value) != null;
1538		}
1539
1540		/**
1541	<	* Creates a new, empty map with a default initial capacity (16),
1542	<	* load factor (0.75) and concurrencyLevel (16).
1541	>	* {@inheritDoc}
1542	>	*
1543	>	* @throws NullPointerException if any of the arguments are null
1544		*/
1545	<	public ConcurrentHashMap() {
1546	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1545	>	public boolean replace(K key, V oldValue, V newValue) {
1546	>	if (key == null || oldValue == null || newValue == null)
1547	>	throw new NullPointerException();
1548	>	return replaceNode(key, newValue, oldValue) != null;
1549		}
1550
1551		/**
1552	<	* Creates a new map with the same mappings as the given map.
779	<	* The map is created with a capacity of 1.5 times the number
780	<	* of mappings in the given map or 16 (whichever is greater),
781	<	* and a default load factor (0.75) and concurrencyLevel (16).
1552	>	* {@inheritDoc}
1553		*
1554	<	* @param m the map
1554	>	* @return the previous value associated with the specified key,
1555	>	*         or {@code null} if there was no mapping for the key
1556	>	* @throws NullPointerException if the specified key or value is null
1557		*/
1558	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1559	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1560	<	DEFAULT_INITIAL_CAPACITY),
1561	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
1558	>	public V replace(K key, V value) {
1559	>	if (key == null || value == null)
1560	>	throw new NullPointerException();
1561	>	return replaceNode(key, value, null);
1562		}
1563
1564	+	// Overrides of JDK8+ Map extension method defaults
1565	+
1566		/**
1567	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1567	>	* Returns the value to which the specified key is mapped, or the
1568	>	* given default value if this map contains no mapping for the
1569	>	* key.
1570		*
1571	<	* @return <tt>true</tt> if this map contains no key-value mappings
1571	>	* @param key the key whose associated value is to be returned
1572	>	* @param defaultValue the value to return if this map contains
1573	>	* no mapping for the given key
1574	>	* @return the mapping for the key, if present; else the default value
1575	>	* @throws NullPointerException if the specified key is null
1576		*/
1577	<	public boolean isEmpty() {
1578	<	/*
1579	<	* Sum per-segment modCounts to avoid mis-reporting when
1580	<	* elements are concurrently added and removed in one segment
1581	<	* while checking another, in which case the table was never
1582	<	* actually empty at any point. (The sum ensures accuracy up
1583	<	* through at least 1<<31 per-segment modifications before
1584	<	* recheck.)  Methods size() and containsValue() use similar
1585	<	* constructions for stability checks.
1586	<	*/
1587	<	long sum = 0L;
1588	<	final Segment<K,V>[] segments = this.segments;
809	<	for (int j = 0; j < segments.length; ++j) {
810	<	Segment<K,V> seg = segmentAt(segments, j);
811	<	if (seg != null) {
812	<	if (seg.count != 0)
813	<	return false;
814	<	sum += seg.modCount;
1577	>	public V getOrDefault(Object key, V defaultValue) {
1578	>	V v;
1579	>	return (v = get(key)) == null ? defaultValue : v;
1580	>	}
1581	>
1582	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1583	>	if (action == null) throw new NullPointerException();
1584	>	Node<K,V>[] t;
1585	>	if ((t = table) != null) {
1586	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1587	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1588	>	action.accept(p.key, p.val);
1589		}
1590		}
1591	<	if (sum != 0L) { // recheck unless no modifications
1592	<	for (int j = 0; j < segments.length; ++j) {
1593	<	Segment<K,V> seg = segmentAt(segments, j);
1594	<	if (seg != null) {
1595	<	if (seg.count != 0)
1596	<	return false;
1597	<	sum -= seg.modCount;
1591	>	}
1592	>
1593	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1594	>	if (function == null) throw new NullPointerException();
1595	>	Node<K,V>[] t;
1596	>	if ((t = table) != null) {
1597	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1598	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1599	>	V oldValue = p.val;
1600	>	for (K key = p.key;;) {
1601	>	V newValue = function.apply(key, oldValue);
1602	>	if (newValue == null)
1603	>	throw new NullPointerException();
1604	>	if (replaceNode(key, newValue, oldValue) != null ||
1605	>	(oldValue = get(key)) == null)
1606	>	break;
1607		}
1608		}
826	–	if (sum != 0L)
827	–	return false;
1609		}
829	–	return true;
1610		}
1611
1612		/**
1613	<	* Returns the number of key-value mappings in this map.  If the
834	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
835	<	* <tt>Integer.MAX_VALUE</tt>.
836	<	*
837	<	* @return the number of key-value mappings in this map
1613	>	* Helper method for EntrySetView.removeIf.
1614		*/
1615	<	public int size() {
1616	<	// Try a few times to get accurate count. On failure due to
1617	<	// continuous async changes in table, resort to locking.
1618	<	final Segment<K,V>[] segments = this.segments;
1619	<	final int segmentCount = segments.length;
1620	<
1621	<	long previousSum = 0L;
1622	<	for (int retries = -1; retries < RETRIES_BEFORE_LOCK; retries++) {
1623	<	long sum = 0L;    // sum of modCounts
1624	<	long size = 0L;
1625	<	for (int i = 0; i < segmentCount; i++) {
1626	<	Segment<K,V> segment = segmentAt(segments, i);
1627	<	if (segment != null) {
852	<	sum += segment.modCount;
853	<	size += segment.count;
854	<	}
855	<	}
856	<	if (sum == previousSum)
857	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
858	<	previousSum = sum;
1615	>	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1616	>	if (function == null) throw new NullPointerException();
1617	>	Node<K,V>[] t;
1618	>	boolean removed = false;
1619	>	if ((t = table) != null) {
1620	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1621	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1622	>	K k = p.key;
1623	>	V v = p.val;
1624	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1625	>	if (function.test(e) && replaceNode(k, null, v) != null)
1626	>	removed = true;
1627	>	}
1628		}
1629	+	return removed;
1630	+	}
1631
1632	<	long size = 0L;
1633	<	for (int i = 0; i < segmentCount; i++) {
1634	<	Segment<K,V> segment = ensureSegment(i);
1635	<	segment.lock();
1636	<	size += segment.count;
1637	<	}
1638	<	for (int i = 0; i < segmentCount; i++)
1639	<	segments[i].unlock();
1640	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1632	>	/**
1633	>	* Helper method for ValuesView.removeIf.
1634	>	*/
1635	>	boolean removeValueIf(Predicate<? super V> function) {
1636	>	if (function == null) throw new NullPointerException();
1637	>	Node<K,V>[] t;
1638	>	boolean removed = false;
1639	>	if ((t = table) != null) {
1640	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1641	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1642	>	K k = p.key;
1643	>	V v = p.val;
1644	>	if (function.test(v) && replaceNode(k, null, v) != null)
1645	>	removed = true;
1646	>	}
1647	>	}
1648	>	return removed;
1649		}
1650
1651		/**
1652	<	* Returns the value to which the specified key is mapped,
1653	<	* or {@code null} if this map contains no mapping for the key.
1652	>	* If the specified key is not already associated with a value,
1653	>	* attempts to compute its value using the given mapping function
1654	>	* and enters it into this map unless {@code null}.  The entire
1655	>	* method invocation is performed atomically, so the function is
1656	>	* applied at most once per key.  Some attempted update operations
1657	>	* on this map by other threads may be blocked while computation
1658	>	* is in progress, so the computation should be short and simple,
1659	>	* and must not attempt to update any other mappings of this map.
1660		*
1661	<	* <p>More formally, if this map contains a mapping from a key
1662	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1663	<	* then this method returns {@code v}; otherwise it returns
1664	<	* {@code null}.  (There can be at most one such mapping.)
1665	<	*
1666	<	* @throws NullPointerException if the specified key is null
1661	>	* @param key key with which the specified value is to be associated
1662	>	* @param mappingFunction the function to compute a value
1663	>	* @return the current (existing or computed) value associated with
1664	>	*         the specified key, or null if the computed value is null
1665	>	* @throws NullPointerException if the specified key or mappingFunction
1666	>	*         is null
1667	>	* @throws IllegalStateException if the computation detectably
1668	>	*         attempts a recursive update to this map that would
1669	>	*         otherwise never complete
1670	>	* @throws RuntimeException or Error if the mappingFunction does so,
1671	>	*         in which case the mapping is left unestablished
1672		*/
1673	<	public V get(Object key) {
1674	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1675	<	HashEntry<K,V>[] tab;
1676	<	int h = hash(key.hashCode());
1677	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1678	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1679	<	(tab = s.table) != null) {
1680	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1681	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1682	<	e != null; e = e.next) {
1683	<	K k;
1684	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1685	<	return e.value;
1673	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1674	>	if (key == null || mappingFunction == null)
1675	>	throw new NullPointerException();
1676	>	int h = spread(key.hashCode());
1677	>	V val = null;
1678	>	int binCount = 0;
1679	>	for (Node<K,V>[] tab = table;;) {
1680	>	Node<K,V> f; int n, i, fh; K fk; V fv;
1681	>	if (tab == null || (n = tab.length) == 0)
1682	>	tab = initTable();
1683	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1684	>	Node<K,V> r = new ReservationNode<K,V>();
1685	>	synchronized (r) {
1686	>	if (casTabAt(tab, i, null, r)) {
1687	>	binCount = 1;
1688	>	Node<K,V> node = null;
1689	>	try {
1690	>	if ((val = mappingFunction.apply(key)) != null)
1691	>	node = new Node<K,V>(h, key, val);
1692	>	} finally {
1693	>	setTabAt(tab, i, node);
1694	>	}
1695	>	}
1696	>	}
1697	>	if (binCount != 0)
1698	>	break;
1699	>	}
1700	>	else if ((fh = f.hash) == MOVED)
1701	>	tab = helpTransfer(tab, f);
1702	>	else if (fh == h    // check first node without acquiring lock
1703	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1704	>	&& (fv = f.val) != null)
1705	>	return fv;
1706	>	else {
1707	>	boolean added = false;
1708	>	synchronized (f) {
1709	>	if (tabAt(tab, i) == f) {
1710	>	if (fh >= 0) {
1711	>	binCount = 1;
1712	>	for (Node<K,V> e = f;; ++binCount) {
1713	>	K ek;
1714	>	if (e.hash == h &&
1715	>	((ek = e.key) == key ||
1716	>	(ek != null && key.equals(ek)))) {
1717	>	val = e.val;
1718	>	break;
1719	>	}
1720	>	Node<K,V> pred = e;
1721	>	if ((e = e.next) == null) {
1722	>	if ((val = mappingFunction.apply(key)) != null) {
1723	>	if (pred.next != null)
1724	>	throw new IllegalStateException("Recursive update");
1725	>	added = true;
1726	>	pred.next = new Node<K,V>(h, key, val);
1727	>	}
1728	>	break;
1729	>	}
1730	>	}
1731	>	}
1732	>	else if (f instanceof TreeBin) {
1733	>	binCount = 2;
1734	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1735	>	TreeNode<K,V> r, p;
1736	>	if ((r = t.root) != null &&
1737	>	(p = r.findTreeNode(h, key, null)) != null)
1738	>	val = p.val;
1739	>	else if ((val = mappingFunction.apply(key)) != null) {
1740	>	added = true;
1741	>	t.putTreeVal(h, key, val);
1742	>	}
1743	>	}
1744	>	else if (f instanceof ReservationNode)
1745	>	throw new IllegalStateException("Recursive update");
1746	>	}
1747	>	}
1748	>	if (binCount != 0) {
1749	>	if (binCount >= TREEIFY_THRESHOLD)
1750	>	treeifyBin(tab, i);
1751	>	if (!added)
1752	>	return val;
1753	>	break;
1754	>	}
1755		}
1756		}
1757	<	return null;
1757	>	if (val != null)
1758	>	addCount(1L, binCount);
1759	>	return val;
1760		}
1761
1762		/**
1763	<	* Tests if the specified object is a key in this table.
1763	>	* If the value for the specified key is present, attempts to
1764	>	* compute a new mapping given the key and its current mapped
1765	>	* value.  The entire method invocation is performed atomically.
1766	>	* Some attempted update operations on this map by other threads
1767	>	* may be blocked while computation is in progress, so the
1768	>	* computation should be short and simple, and must not attempt to
1769	>	* update any other mappings of this map.
1770		*
1771	<	* @param  key   possible key
1772	<	* @return <tt>true</tt> if and only if the specified object
1773	<	*         is a key in this table, as determined by the
1774	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1775	<	* @throws NullPointerException if the specified key is null
1771	>	* @param key key with which a value may be associated
1772	>	* @param remappingFunction the function to compute a value
1773	>	* @return the new value associated with the specified key, or null if none
1774	>	* @throws NullPointerException if the specified key or remappingFunction
1775	>	*         is null
1776	>	* @throws IllegalStateException if the computation detectably
1777	>	*         attempts a recursive update to this map that would
1778	>	*         otherwise never complete
1779	>	* @throws RuntimeException or Error if the remappingFunction does so,
1780	>	*         in which case the mapping is unchanged
1781		*/
1782	<	@SuppressWarnings("unchecked")
1783	<	public boolean containsKey(Object key) {
1784	<	Segment<K,V> s; // same as get() except no need for volatile value read
1785	<	HashEntry<K,V>[] tab;
1786	<	int h = hash(key.hashCode());
1787	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1788	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1789	<	(tab = s.table) != null) {
1790	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1791	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1792	<	e != null; e = e.next) {
1793	<	K k;
1794	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1795	<	return true;
1782	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1783	>	if (key == null || remappingFunction == null)
1784	>	throw new NullPointerException();
1785	>	int h = spread(key.hashCode());
1786	>	V val = null;
1787	>	int delta = 0;
1788	>	int binCount = 0;
1789	>	for (Node<K,V>[] tab = table;;) {
1790	>	Node<K,V> f; int n, i, fh;
1791	>	if (tab == null || (n = tab.length) == 0)
1792	>	tab = initTable();
1793	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1794	>	break;
1795	>	else if ((fh = f.hash) == MOVED)
1796	>	tab = helpTransfer(tab, f);
1797	>	else {
1798	>	synchronized (f) {
1799	>	if (tabAt(tab, i) == f) {
1800	>	if (fh >= 0) {
1801	>	binCount = 1;
1802	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1803	>	K ek;
1804	>	if (e.hash == h &&
1805	>	((ek = e.key) == key ||
1806	>	(ek != null && key.equals(ek)))) {
1807	>	val = remappingFunction.apply(key, e.val);
1808	>	if (val != null)
1809	>	e.val = val;
1810	>	else {
1811	>	delta = -1;
1812	>	Node<K,V> en = e.next;
1813	>	if (pred != null)
1814	>	pred.next = en;
1815	>	else
1816	>	setTabAt(tab, i, en);
1817	>	}
1818	>	break;
1819	>	}
1820	>	pred = e;
1821	>	if ((e = e.next) == null)
1822	>	break;
1823	>	}
1824	>	}
1825	>	else if (f instanceof TreeBin) {
1826	>	binCount = 2;
1827	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1828	>	TreeNode<K,V> r, p;
1829	>	if ((r = t.root) != null &&
1830	>	(p = r.findTreeNode(h, key, null)) != null) {
1831	>	val = remappingFunction.apply(key, p.val);
1832	>	if (val != null)
1833	>	p.val = val;
1834	>	else {
1835	>	delta = -1;
1836	>	if (t.removeTreeNode(p))
1837	>	setTabAt(tab, i, untreeify(t.first));
1838	>	}
1839	>	}
1840	>	}
1841	>	else if (f instanceof ReservationNode)
1842	>	throw new IllegalStateException("Recursive update");
1843	>	}
1844	>	}
1845	>	if (binCount != 0)
1846	>	break;
1847		}
1848		}
1849	<	return false;
1849	>	if (delta != 0)
1850	>	addCount((long)delta, binCount);
1851	>	return val;
1852		}
1853
1854		/**
1855	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1856	<	* specified value. Note: This method requires a full internal
1857	<	* traversal of the hash table, and so is much slower than
1858	<	* method <tt>containsKey</tt>.
1855	>	* Attempts to compute a mapping for the specified key and its
1856	>	* current mapped value (or {@code null} if there is no current
1857	>	* mapping). The entire method invocation is performed atomically.
1858	>	* Some attempted update operations on this map by other threads
1859	>	* may be blocked while computation is in progress, so the
1860	>	* computation should be short and simple, and must not attempt to
1861	>	* update any other mappings of this Map.
1862		*
1863	<	* @param value value whose presence in this map is to be tested
1864	<	* @return <tt>true</tt> if this map maps one or more keys to the
1865	<	*         specified value
1866	<	* @throws NullPointerException if the specified value is null
1863	>	* @param key key with which the specified value is to be associated
1864	>	* @param remappingFunction the function to compute a value
1865	>	* @return the new value associated with the specified key, or null if none
1866	>	* @throws NullPointerException if the specified key or remappingFunction
1867	>	*         is null
1868	>	* @throws IllegalStateException if the computation detectably
1869	>	*         attempts a recursive update to this map that would
1870	>	*         otherwise never complete
1871	>	* @throws RuntimeException or Error if the remappingFunction does so,
1872	>	*         in which case the mapping is unchanged
1873	>	*/
1874	>	public V compute(K key,
1875	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1876	>	if (key == null || remappingFunction == null)
1877	>	throw new NullPointerException();
1878	>	int h = spread(key.hashCode());
1879	>	V val = null;
1880	>	int delta = 0;
1881	>	int binCount = 0;
1882	>	for (Node<K,V>[] tab = table;;) {
1883	>	Node<K,V> f; int n, i, fh;
1884	>	if (tab == null || (n = tab.length) == 0)
1885	>	tab = initTable();
1886	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1887	>	Node<K,V> r = new ReservationNode<K,V>();
1888	>	synchronized (r) {
1889	>	if (casTabAt(tab, i, null, r)) {
1890	>	binCount = 1;
1891	>	Node<K,V> node = null;
1892	>	try {
1893	>	if ((val = remappingFunction.apply(key, null)) != null) {
1894	>	delta = 1;
1895	>	node = new Node<K,V>(h, key, val);
1896	>	}
1897	>	} finally {
1898	>	setTabAt(tab, i, node);
1899	>	}
1900	>	}
1901	>	}
1902	>	if (binCount != 0)
1903	>	break;
1904	>	}
1905	>	else if ((fh = f.hash) == MOVED)
1906	>	tab = helpTransfer(tab, f);
1907	>	else {
1908	>	synchronized (f) {
1909	>	if (tabAt(tab, i) == f) {
1910	>	if (fh >= 0) {
1911	>	binCount = 1;
1912	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1913	>	K ek;
1914	>	if (e.hash == h &&
1915	>	((ek = e.key) == key ||
1916	>	(ek != null && key.equals(ek)))) {
1917	>	val = remappingFunction.apply(key, e.val);
1918	>	if (val != null)
1919	>	e.val = val;
1920	>	else {
1921	>	delta = -1;
1922	>	Node<K,V> en = e.next;
1923	>	if (pred != null)
1924	>	pred.next = en;
1925	>	else
1926	>	setTabAt(tab, i, en);
1927	>	}
1928	>	break;
1929	>	}
1930	>	pred = e;
1931	>	if ((e = e.next) == null) {
1932	>	val = remappingFunction.apply(key, null);
1933	>	if (val != null) {
1934	>	if (pred.next != null)
1935	>	throw new IllegalStateException("Recursive update");
1936	>	delta = 1;
1937	>	pred.next = new Node<K,V>(h, key, val);
1938	>	}
1939	>	break;
1940	>	}
1941	>	}
1942	>	}
1943	>	else if (f instanceof TreeBin) {
1944	>	binCount = 1;
1945	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1946	>	TreeNode<K,V> r, p;
1947	>	if ((r = t.root) != null)
1948	>	p = r.findTreeNode(h, key, null);
1949	>	else
1950	>	p = null;
1951	>	V pv = (p == null) ? null : p.val;
1952	>	val = remappingFunction.apply(key, pv);
1953	>	if (val != null) {
1954	>	if (p != null)
1955	>	p.val = val;
1956	>	else {
1957	>	delta = 1;
1958	>	t.putTreeVal(h, key, val);
1959	>	}
1960	>	}
1961	>	else if (p != null) {
1962	>	delta = -1;
1963	>	if (t.removeTreeNode(p))
1964	>	setTabAt(tab, i, untreeify(t.first));
1965	>	}
1966	>	}
1967	>	else if (f instanceof ReservationNode)
1968	>	throw new IllegalStateException("Recursive update");
1969	>	}
1970	>	}
1971	>	if (binCount != 0) {
1972	>	if (binCount >= TREEIFY_THRESHOLD)
1973	>	treeifyBin(tab, i);
1974	>	break;
1975	>	}
1976	>	}
1977	>	}
1978	>	if (delta != 0)
1979	>	addCount((long)delta, binCount);
1980	>	return val;
1981	>	}
1982	>
1983	>	/**
1984	>	* If the specified key is not already associated with a
1985	>	* (non-null) value, associates it with the given value.
1986	>	* Otherwise, replaces the value with the results of the given
1987	>	* remapping function, or removes if {@code null}. The entire
1988	>	* method invocation is performed atomically.  Some attempted
1989	>	* update operations on this map by other threads may be blocked
1990	>	* while computation is in progress, so the computation should be
1991	>	* short and simple, and must not attempt to update any other
1992	>	* mappings of this Map.
1993	>	*
1994	>	* @param key key with which the specified value is to be associated
1995	>	* @param value the value to use if absent
1996	>	* @param remappingFunction the function to recompute a value if present
1997	>	* @return the new value associated with the specified key, or null if none
1998	>	* @throws NullPointerException if the specified key or the
1999	>	*         remappingFunction is null
2000	>	* @throws RuntimeException or Error if the remappingFunction does so,
2001	>	*         in which case the mapping is unchanged
2002		*/
2003	<	public boolean containsValue(Object value) {
2004	<	// Same idea as size()
942	<	if (value == null)
2003	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
2004	>	if (key == null || value == null || remappingFunction == null)
2005		throw new NullPointerException();
2006	<	final Segment<K,V>[] segments = this.segments;
2007	<	long previousSum = 0L;
2008	<	int lockCount = 0;
2009	<	try {
2010	<	for (int retries = -1; ; retries++) {
2011	<	long sum = 0L;    // sum of modCounts
2012	<	for (int j = 0; j < segments.length; j++) {
2013	<	Segment<K,V> segment;
2014	<	if (retries == RETRIES_BEFORE_LOCK) {
2015	<	segment = ensureSegment(j);
2016	<	segment.lock();
2017	<	lockCount++;
2018	<	} else {
2019	<	segment = segmentAt(segments, j);
2020	<	if (segment == null)
2021	<	continue;
2022	<	}
2023	<	HashEntry<K,V>[] tab = segment.table;
2024	<	if (tab != null) {
2025	<	for (int i = 0 ; i < tab.length; i++) {
2026	<	HashEntry<K,V> e;
2027	<	for (e = entryAt(tab, i); e != null; e = e.next) {
2028	<	V v = e.value;
2029	<	if (v != null && value.equals(v))
2030	<	return true;
2006	>	int h = spread(key.hashCode());
2007	>	V val = null;
2008	>	int delta = 0;
2009	>	int binCount = 0;
2010	>	for (Node<K,V>[] tab = table;;) {
2011	>	Node<K,V> f; int n, i, fh;
2012	>	if (tab == null || (n = tab.length) == 0)
2013	>	tab = initTable();
2014	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2015	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2016	>	delta = 1;
2017	>	val = value;
2018	>	break;
2019	>	}
2020	>	}
2021	>	else if ((fh = f.hash) == MOVED)
2022	>	tab = helpTransfer(tab, f);
2023	>	else {
2024	>	synchronized (f) {
2025	>	if (tabAt(tab, i) == f) {
2026	>	if (fh >= 0) {
2027	>	binCount = 1;
2028	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
2029	>	K ek;
2030	>	if (e.hash == h &&
2031	>	((ek = e.key) == key ||
2032	>	(ek != null && key.equals(ek)))) {
2033	>	val = remappingFunction.apply(e.val, value);
2034	>	if (val != null)
2035	>	e.val = val;
2036	>	else {
2037	>	delta = -1;
2038	>	Node<K,V> en = e.next;
2039	>	if (pred != null)
2040	>	pred.next = en;
2041	>	else
2042	>	setTabAt(tab, i, en);
2043	>	}
2044	>	break;
2045	>	}
2046	>	pred = e;
2047	>	if ((e = e.next) == null) {
2048	>	delta = 1;
2049	>	val = value;
2050	>	pred.next = new Node<K,V>(h, key, val);
2051	>	break;
2052	>	}
2053		}
2054		}
2055	<	sum += segment.modCount;
2055	>	else if (f instanceof TreeBin) {
2056	>	binCount = 2;
2057	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2058	>	TreeNode<K,V> r = t.root;
2059	>	TreeNode<K,V> p = (r == null) ? null :
2060	>	r.findTreeNode(h, key, null);
2061	>	val = (p == null) ? value :
2062	>	remappingFunction.apply(p.val, value);
2063	>	if (val != null) {
2064	>	if (p != null)
2065	>	p.val = val;
2066	>	else {
2067	>	delta = 1;
2068	>	t.putTreeVal(h, key, val);
2069	>	}
2070	>	}
2071	>	else if (p != null) {
2072	>	delta = -1;
2073	>	if (t.removeTreeNode(p))
2074	>	setTabAt(tab, i, untreeify(t.first));
2075	>	}
2076	>	}
2077	>	else if (f instanceof ReservationNode)
2078	>	throw new IllegalStateException("Recursive update");
2079		}
2080		}
2081	<	if ((retries >= 0 && sum == previousSum) || lockCount > 0)
2082	<	return false;
2083	<	previousSum = sum;
2081	>	if (binCount != 0) {
2082	>	if (binCount >= TREEIFY_THRESHOLD)
2083	>	treeifyBin(tab, i);
2084	>	break;
2085	>	}
2086		}
978	–	} finally {
979	–	for (int j = 0; j < lockCount; j++)
980	–	segments[j].unlock();
2087		}
2088	+	if (delta != 0)
2089	+	addCount((long)delta, binCount);
2090	+	return val;
2091		}
2092
2093	+	// Hashtable legacy methods
2094	+
2095		/**
2096	<	* Legacy method testing if some key maps into the specified value
2097	<	* in this table.  This method is identical in functionality to
2098	<	* {@link #containsValue}, and exists solely to ensure
2096	>	* Tests if some key maps into the specified value in this table.
2097	>	*
2098	>	* <p>Note that this method is identical in functionality to
2099	>	* {@link #containsValue(Object)}, and exists solely to ensure
2100		* full compatibility with class {@link java.util.Hashtable},
2101		* which supported this method prior to introduction of the
2102	<	* Java Collections framework.
2102	>	* Java Collections Framework.
2103		*
2104		* @param  value a value to search for
2105	<	* @return <tt>true</tt> if and only if some key maps to the
2106	<	*         <tt>value</tt> argument in this table as
2107	<	*         determined by the <tt>equals</tt> method;
2108	<	*         <tt>false</tt> otherwise
2105	>	* @return {@code true} if and only if some key maps to the
2106	>	*         {@code value} argument in this table as
2107	>	*         determined by the {@code equals} method;
2108	>	*         {@code false} otherwise
2109		* @throws NullPointerException if the specified value is null
2110		*/
2111		public boolean contains(Object value) {
#	Line 1001 | Line 2113 | public class ConcurrentHashMap<K, V> ext
2113		}
2114
2115		/**
2116	<	* Maps the specified key to the specified value in this table.
1005	<	* Neither the key nor the value can be null.
1006	<	*
1007	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1008	<	* with a key that is equal to the original key.
2116	>	* Returns an enumeration of the keys in this table.
2117		*
2118	<	* @param key key with which the specified value is to be associated
2119	<	* @param value value to be associated with the specified key
1012	<	* @return the previous value associated with <tt>key</tt>, or
1013	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1014	<	* @throws NullPointerException if the specified key or value is null
2118	>	* @return an enumeration of the keys in this table
2119	>	* @see #keySet()
2120		*/
2121	<	@SuppressWarnings("unchecked")
2122	<	public V put(K key, V value) {
2123	<	Segment<K,V> s;
2124	<	if (value == null)
1020	<	throw new NullPointerException();
1021	<	int hash = hash(key.hashCode());
1022	<	int j = (hash >>> segmentShift) & segmentMask;
1023	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1024	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1025	<	s = ensureSegment(j);
1026	<	return s.put(key, hash, value, false);
2121	>	public Enumeration<K> keys() {
2122	>	Node<K,V>[] t;
2123	>	int f = (t = table) == null ? 0 : t.length;
2124	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2125		}
2126
2127		/**
2128	<	* {@inheritDoc}
2128	>	* Returns an enumeration of the values in this table.
2129		*
2130	<	* @return the previous value associated with the specified key,
2131	<	*         or <tt>null</tt> if there was no mapping for the key
1034	<	* @throws NullPointerException if the specified key or value is null
2130	>	* @return an enumeration of the values in this table
2131	>	* @see #values()
2132		*/
2133	<	@SuppressWarnings("unchecked")
2134	<	public V putIfAbsent(K key, V value) {
2135	<	Segment<K,V> s;
2136	<	if (value == null)
1040	<	throw new NullPointerException();
1041	<	int hash = hash(key.hashCode());
1042	<	int j = (hash >>> segmentShift) & segmentMask;
1043	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1044	<	(segments, (j << SSHIFT) + SBASE)) == null)
1045	<	s = ensureSegment(j);
1046	<	return s.put(key, hash, value, true);
2133	>	public Enumeration<V> elements() {
2134	>	Node<K,V>[] t;
2135	>	int f = (t = table) == null ? 0 : t.length;
2136	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2137		}
2138
2139	+	// ConcurrentHashMap-only methods
2140	+
2141		/**
2142	<	* Copies all of the mappings from the specified map to this one.
2143	<	* These mappings replace any mappings that this map had for any of the
2144	<	* keys currently in the specified map.
2142	>	* Returns the number of mappings. This method should be used
2143	>	* instead of {@link #size} because a ConcurrentHashMap may
2144	>	* contain more mappings than can be represented as an int. The
2145	>	* value returned is an estimate; the actual count may differ if
2146	>	* there are concurrent insertions or removals.
2147		*
2148	<	* @param m mappings to be stored in this map
2148	>	* @return the number of mappings
2149	>	* @since 1.8
2150		*/
2151	<	public void putAll(Map<? extends K, ? extends V> m) {
2152	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2153	<	put(e.getKey(), e.getValue());
2151	>	public long mappingCount() {
2152	>	long n = sumCount();
2153	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2154		}
2155
2156		/**
2157	<	* Removes the key (and its corresponding value) from this map.
2158	<	* This method does nothing if the key is not in the map.
2157	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2158	>	* from the given type to {@code Boolean.TRUE}.
2159		*
2160	<	* @param  key the key that needs to be removed
2161	<	* @return the previous value associated with <tt>key</tt>, or
2162	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1068	<	* @throws NullPointerException if the specified key is null
2160	>	* @param <K> the element type of the returned set
2161	>	* @return the new set
2162	>	* @since 1.8
2163		*/
2164	<	public V remove(Object key) {
2165	<	int hash = hash(key.hashCode());
2166	<	Segment<K,V> s = segmentForHash(hash);
1073	<	return s == null ? null : s.remove(key, hash, null);
2164	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2165	>	return new KeySetView<K,Boolean>
2166	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2167		}
2168
2169		/**
2170	<	* {@inheritDoc}
2170	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2171	>	* from the given type to {@code Boolean.TRUE}.
2172		*
2173	<	* @throws NullPointerException if the specified key is null
2173	>	* @param initialCapacity The implementation performs internal
2174	>	* sizing to accommodate this many elements.
2175	>	* @param <K> the element type of the returned set
2176	>	* @return the new set
2177	>	* @throws IllegalArgumentException if the initial capacity of
2178	>	* elements is negative
2179	>	* @since 1.8
2180		*/
2181	<	public boolean remove(Object key, Object value) {
2182	<	int hash = hash(key.hashCode());
2183	<	Segment<K,V> s;
1084	<	return value != null && (s = segmentForHash(hash)) != null &&
1085	<	s.remove(key, hash, value) != null;
2181	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2182	>	return new KeySetView<K,Boolean>
2183	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2184		}
2185
2186		/**
2187	<	* {@inheritDoc}
2187	>	* Returns a {@link Set} view of the keys in this map, using the
2188	>	* given common mapped value for any additions (i.e., {@link
2189	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2190	>	* This is of course only appropriate if it is acceptable to use
2191	>	* the same value for all additions from this view.
2192		*
2193	<	* @throws NullPointerException if any of the arguments are null
2193	>	* @param mappedValue the mapped value to use for any additions
2194	>	* @return the set view
2195	>	* @throws NullPointerException if the mappedValue is null
2196		*/
2197	<	public boolean replace(K key, V oldValue, V newValue) {
2198	<	int hash = hash(key.hashCode());
1095	<	if (oldValue == null || newValue == null)
2197	>	public KeySetView<K,V> keySet(V mappedValue) {
2198	>	if (mappedValue == null)
2199		throw new NullPointerException();
2200	<	Segment<K,V> s = segmentForHash(hash);
1098	<	return s != null && s.replace(key, hash, oldValue, newValue);
2200	>	return new KeySetView<K,V>(this, mappedValue);
2201		}
2202
2203	+	/* ---------------- Special Nodes -------------- */
2204	+
2205		/**
2206	<	* {@inheritDoc}
1103	<	*
1104	<	* @return the previous value associated with the specified key,
1105	<	*         or <tt>null</tt> if there was no mapping for the key
1106	<	* @throws NullPointerException if the specified key or value is null
2206	>	* A node inserted at head of bins during transfer operations.
2207		*/
2208	<	public V replace(K key, V value) {
2209	<	int hash = hash(key.hashCode());
2210	<	if (value == null)
2211	<	throw new NullPointerException();
2212	<	Segment<K,V> s = segmentForHash(hash);
2213	<	return s == null ? null : s.replace(key, hash, value);
2208	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2209	>	final Node<K,V>[] nextTable;
2210	>	ForwardingNode(Node<K,V>[] tab) {
2211	>	super(MOVED, null, null);
2212	>	this.nextTable = tab;
2213	>	}
2214	>
2215	>	Node<K,V> find(int h, Object k) {
2216	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2217	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2218	>	Node<K,V> e; int n;
2219	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2220	>	(e = tabAt(tab, (n - 1) & h)) == null)
2221	>	return null;
2222	>	for (;;) {
2223	>	int eh; K ek;
2224	>	if ((eh = e.hash) == h &&
2225	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2226	>	return e;
2227	>	if (eh < 0) {
2228	>	if (e instanceof ForwardingNode) {
2229	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2230	>	continue outer;
2231	>	}
2232	>	else
2233	>	return e.find(h, k);
2234	>	}
2235	>	if ((e = e.next) == null)
2236	>	return null;
2237	>	}
2238	>	}
2239	>	}
2240		}
2241
2242		/**
2243	<	* Removes all of the mappings from this map.
2243	>	* A place-holder node used in computeIfAbsent and compute.
2244		*/
2245	<	public void clear() {
2246	<	final Segment<K,V>[] segments = this.segments;
2247	<	for (int j = 0; j < segments.length; ++j) {
2248	<	Segment<K,V> s = segmentAt(segments, j);
2249	<	if (s != null)
2250	<	s.clear();
2245	>	static final class ReservationNode<K,V> extends Node<K,V> {
2246	>	ReservationNode() {
2247	>	super(RESERVED, null, null);
2248	>	}
2249	>
2250	>	Node<K,V> find(int h, Object k) {
2251	>	return null;
2252		}
2253		}
2254
2255	+	/* ---------------- Table Initialization and Resizing -------------- */
2256	+
2257		/**
2258	<	* Returns a {@link Set} view of the keys contained in this map.
2259	<	* The set is backed by the map, so changes to the map are
2260	<	* reflected in the set, and vice-versa.  The set supports element
2261	<	* removal, which removes the corresponding mapping from this map,
2262	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1134	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1135	<	* operations.  It does not support the <tt>add</tt> or
1136	<	* <tt>addAll</tt> operations.
1137	<	*
1138	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1139	<	* that will never throw {@link ConcurrentModificationException},
1140	<	* and guarantees to traverse elements as they existed upon
1141	<	* construction of the iterator, and may (but is not guaranteed to)
1142	<	* reflect any modifications subsequent to construction.
1143	<	*/
1144	<	public Set<K> keySet() {
1145	<	Set<K> ks = keySet;
1146	<	return (ks != null) ? ks : (keySet = new KeySet());
2258	>	* Returns the stamp bits for resizing a table of size n.
2259	>	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2260	>	*/
2261	>	static final int resizeStamp(int n) {
2262	>	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2263		}
2264
2265		/**
2266	<	* Returns a {@link Collection} view of the values contained in this map.
1151	<	* The collection is backed by the map, so changes to the map are
1152	<	* reflected in the collection, and vice-versa.  The collection
1153	<	* supports element removal, which removes the corresponding
1154	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1155	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1156	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1157	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1158	<	*
1159	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1160	<	* that will never throw {@link ConcurrentModificationException},
1161	<	* and guarantees to traverse elements as they existed upon
1162	<	* construction of the iterator, and may (but is not guaranteed to)
1163	<	* reflect any modifications subsequent to construction.
2266	>	* Initializes table, using the size recorded in sizeCtl.
2267		*/
2268	<	public Collection<V> values() {
2269	<	Collection<V> vs = values;
2270	<	return (vs != null) ? vs : (values = new Values());
2268	>	private final Node<K,V>[] initTable() {
2269	>	Node<K,V>[] tab; int sc;
2270	>	while ((tab = table) == null || tab.length == 0) {
2271	>	if ((sc = sizeCtl) < 0)
2272	>	Thread.yield(); // lost initialization race; just spin
2273	>	else if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2274	>	try {
2275	>	if ((tab = table) == null || tab.length == 0) {
2276	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2277	>	@SuppressWarnings("unchecked")
2278	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2279	>	table = tab = nt;
2280	>	sc = n - (n >>> 2);
2281	>	}
2282	>	} finally {
2283	>	sizeCtl = sc;
2284	>	}
2285	>	break;
2286	>	}
2287	>	}
2288	>	return tab;
2289		}
2290
2291		/**
2292	<	* Returns a {@link Set} view of the mappings contained in this map.
2293	<	* The set is backed by the map, so changes to the map are
2294	<	* reflected in the set, and vice-versa.  The set supports element
2295	<	* removal, which removes the corresponding mapping from the map,
2296	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2297	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2298	<	* operations.  It does not support the <tt>add</tt> or
2299	<	* <tt>addAll</tt> operations.
1179	<	*
1180	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1181	<	* that will never throw {@link ConcurrentModificationException},
1182	<	* and guarantees to traverse elements as they existed upon
1183	<	* construction of the iterator, and may (but is not guaranteed to)
1184	<	* reflect any modifications subsequent to construction.
2292	>	* Adds to count, and if table is too small and not already
2293	>	* resizing, initiates transfer. If already resizing, helps
2294	>	* perform transfer if work is available.  Rechecks occupancy
2295	>	* after a transfer to see if another resize is already needed
2296	>	* because resizings are lagging additions.
2297	>	*
2298	>	* @param x the count to add
2299	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2300		*/
2301	<	public Set<Map.Entry<K,V>> entrySet() {
2302	<	Set<Map.Entry<K,V>> es = entrySet;
2303	<	return (es != null) ? es : (entrySet = new EntrySet());
2301	>	private final void addCount(long x, int check) {
2302	>	CounterCell[] cs; long b, s;
2303	>	if ((cs = counterCells) != null ||
2304	>	!U.compareAndSetLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2305	>	CounterCell c; long v; int m;
2306	>	boolean uncontended = true;
2307	>	if (cs == null || (m = cs.length - 1) < 0 ||
2308	>	(c = cs[ThreadLocalRandom.getProbe() & m]) == null ||
2309	>	!(uncontended =
2310	>	U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))) {
2311	>	fullAddCount(x, uncontended);
2312	>	return;
2313	>	}
2314	>	if (check <= 1)
2315	>	return;
2316	>	s = sumCount();
2317	>	}
2318	>	if (check >= 0) {
2319	>	Node<K,V>[] tab, nt; int n, sc;
2320	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2321	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2322	>	int rs = resizeStamp(n);
2323	>	if (sc < 0) {
2324	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2325	>	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2326	>	transferIndex <= 0)
2327	>	break;
2328	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
2329	>	transfer(tab, nt);
2330	>	}
2331	>	else if (U.compareAndSetInt(this, SIZECTL, sc,
2332	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2333	>	transfer(tab, null);
2334	>	s = sumCount();
2335	>	}
2336	>	}
2337		}
2338
2339		/**
2340	<	* Returns an enumeration of the keys in this table.
1193	<	*
1194	<	* @return an enumeration of the keys in this table
1195	<	* @see #keySet()
2340	>	* Helps transfer if a resize is in progress.
2341		*/
2342	<	public Enumeration<K> keys() {
2343	<	return new KeyIterator();
2342	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2343	>	Node<K,V>[] nextTab; int sc;
2344	>	if (tab != null && (f instanceof ForwardingNode) &&
2345	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2346	>	int rs = resizeStamp(tab.length);
2347	>	while (nextTab == nextTable && table == tab &&
2348	>	(sc = sizeCtl) < 0) {
2349	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2350	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2351	>	break;
2352	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
2353	>	transfer(tab, nextTab);
2354	>	break;
2355	>	}
2356	>	}
2357	>	return nextTab;
2358	>	}
2359	>	return table;
2360		}
2361
2362		/**
2363	<	* Returns an enumeration of the values in this table.
2363	>	* Tries to presize table to accommodate the given number of elements.
2364		*
2365	<	* @return an enumeration of the values in this table
1205	<	* @see #values()
2365	>	* @param size number of elements (doesn't need to be perfectly accurate)
2366		*/
2367	<	public Enumeration<V> elements() {
2368	<	return new ValueIterator();
2367	>	private final void tryPresize(int size) {
2368	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2369	>	tableSizeFor(size + (size >>> 1) + 1);
2370	>	int sc;
2371	>	while ((sc = sizeCtl) >= 0) {
2372	>	Node<K,V>[] tab = table; int n;
2373	>	if (tab == null || (n = tab.length) == 0) {
2374	>	n = (sc > c) ? sc : c;
2375	>	if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2376	>	try {
2377	>	if (table == tab) {
2378	>	@SuppressWarnings("unchecked")
2379	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2380	>	table = nt;
2381	>	sc = n - (n >>> 2);
2382	>	}
2383	>	} finally {
2384	>	sizeCtl = sc;
2385	>	}
2386	>	}
2387	>	}
2388	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2389	>	break;
2390	>	else if (tab == table) {
2391	>	int rs = resizeStamp(n);
2392	>	if (U.compareAndSetInt(this, SIZECTL, sc,
2393	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2394	>	transfer(tab, null);
2395	>	}
2396	>	}
2397		}
2398
2399	<	/* ---------------- Iterator Support -------------- */
2399	>	/**
2400	>	* Moves and/or copies the nodes in each bin to new table. See
2401	>	* above for explanation.
2402	>	*/
2403	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2404	>	int n = tab.length, stride;
2405	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2406	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2407	>	if (nextTab == null) {            // initiating
2408	>	try {
2409	>	@SuppressWarnings("unchecked")
2410	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2411	>	nextTab = nt;
2412	>	} catch (Throwable ex) {      // try to cope with OOME
2413	>	sizeCtl = Integer.MAX_VALUE;
2414	>	return;
2415	>	}
2416	>	nextTable = nextTab;
2417	>	transferIndex = n;
2418	>	}
2419	>	int nextn = nextTab.length;
2420	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2421	>	boolean advance = true;
2422	>	boolean finishing = false; // to ensure sweep before committing nextTab
2423	>	for (int i = 0, bound = 0;;) {
2424	>	Node<K,V> f; int fh;
2425	>	while (advance) {
2426	>	int nextIndex, nextBound;
2427	>	if (--i >= bound || finishing)
2428	>	advance = false;
2429	>	else if ((nextIndex = transferIndex) <= 0) {
2430	>	i = -1;
2431	>	advance = false;
2432	>	}
2433	>	else if (U.compareAndSetInt
2434	>	(this, TRANSFERINDEX, nextIndex,
2435	>	nextBound = (nextIndex > stride ?
2436	>	nextIndex - stride : 0))) {
2437	>	bound = nextBound;
2438	>	i = nextIndex - 1;
2439	>	advance = false;
2440	>	}
2441	>	}
2442	>	if (i < 0 || i >= n || i + n >= nextn) {
2443	>	int sc;
2444	>	if (finishing) {
2445	>	nextTable = null;
2446	>	table = nextTab;
2447	>	sizeCtl = (n << 1) - (n >>> 1);
2448	>	return;
2449	>	}
2450	>	if (U.compareAndSetInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2451	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2452	>	return;
2453	>	finishing = advance = true;
2454	>	i = n; // recheck before commit
2455	>	}
2456	>	}
2457	>	else if ((f = tabAt(tab, i)) == null)
2458	>	advance = casTabAt(tab, i, null, fwd);
2459	>	else if ((fh = f.hash) == MOVED)
2460	>	advance = true; // already processed
2461	>	else {
2462	>	synchronized (f) {
2463	>	if (tabAt(tab, i) == f) {
2464	>	Node<K,V> ln, hn;
2465	>	if (fh >= 0) {
2466	>	int runBit = fh & n;
2467	>	Node<K,V> lastRun = f;
2468	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2469	>	int b = p.hash & n;
2470	>	if (b != runBit) {
2471	>	runBit = b;
2472	>	lastRun = p;
2473	>	}
2474	>	}
2475	>	if (runBit == 0) {
2476	>	ln = lastRun;
2477	>	hn = null;
2478	>	}
2479	>	else {
2480	>	hn = lastRun;
2481	>	ln = null;
2482	>	}
2483	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2484	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2485	>	if ((ph & n) == 0)
2486	>	ln = new Node<K,V>(ph, pk, pv, ln);
2487	>	else
2488	>	hn = new Node<K,V>(ph, pk, pv, hn);
2489	>	}
2490	>	setTabAt(nextTab, i, ln);
2491	>	setTabAt(nextTab, i + n, hn);
2492	>	setTabAt(tab, i, fwd);
2493	>	advance = true;
2494	>	}
2495	>	else if (f instanceof TreeBin) {
2496	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2497	>	TreeNode<K,V> lo = null, loTail = null;
2498	>	TreeNode<K,V> hi = null, hiTail = null;
2499	>	int lc = 0, hc = 0;
2500	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2501	>	int h = e.hash;
2502	>	TreeNode<K,V> p = new TreeNode<K,V>
2503	>	(h, e.key, e.val, null, null);
2504	>	if ((h & n) == 0) {
2505	>	if ((p.prev = loTail) == null)
2506	>	lo = p;
2507	>	else
2508	>	loTail.next = p;
2509	>	loTail = p;
2510	>	++lc;
2511	>	}
2512	>	else {
2513	>	if ((p.prev = hiTail) == null)
2514	>	hi = p;
2515	>	else
2516	>	hiTail.next = p;
2517	>	hiTail = p;
2518	>	++hc;
2519	>	}
2520	>	}
2521	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2522	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2523	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2524	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2525	>	setTabAt(nextTab, i, ln);
2526	>	setTabAt(nextTab, i + n, hn);
2527	>	setTabAt(tab, i, fwd);
2528	>	advance = true;
2529	>	}
2530	>	}
2531	>	}
2532	>	}
2533	>	}
2534	>	}
2535
2536	<	abstract class HashIterator {
1214	<	int nextSegmentIndex;
1215	<	int nextTableIndex;
1216	<	HashEntry<K,V>[] currentTable;
1217	<	HashEntry<K, V> nextEntry;
1218	<	HashEntry<K, V> lastReturned;
2536	>	/* ---------------- Counter support -------------- */
2537
2538	<	HashIterator() {
2539	<	nextSegmentIndex = segments.length - 1;
2540	<	nextTableIndex = -1;
2541	<	advance();
2538	>	/**
2539	>	* A padded cell for distributing counts.  Adapted from LongAdder
2540	>	* and Striped64.  See their internal docs for explanation.
2541	>	*/
2542	>	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2543	>	volatile long value;
2544	>	CounterCell(long x) { value = x; }
2545	>	}
2546	>
2547	>	final long sumCount() {
2548	>	CounterCell[] cs = counterCells;
2549	>	long sum = baseCount;
2550	>	if (cs != null) {
2551	>	for (CounterCell c : cs)
2552	>	if (c != null)
2553	>	sum += c.value;
2554	>	}
2555	>	return sum;
2556	>	}
2557	>
2558	>	// See LongAdder version for explanation
2559	>	private final void fullAddCount(long x, boolean wasUncontended) {
2560	>	int h;
2561	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2562	>	ThreadLocalRandom.localInit();      // force initialization
2563	>	h = ThreadLocalRandom.getProbe();
2564	>	wasUncontended = true;
2565	>	}
2566	>	boolean collide = false;                // True if last slot nonempty
2567	>	for (;;) {
2568	>	CounterCell[] cs; CounterCell c; int n; long v;
2569	>	if ((cs = counterCells) != null && (n = cs.length) > 0) {
2570	>	if ((c = cs[(n - 1) & h]) == null) {
2571	>	if (cellsBusy == 0) {            // Try to attach new Cell
2572	>	CounterCell r = new CounterCell(x); // Optimistic create
2573	>	if (cellsBusy == 0 &&
2574	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2575	>	boolean created = false;
2576	>	try {               // Recheck under lock
2577	>	CounterCell[] rs; int m, j;
2578	>	if ((rs = counterCells) != null &&
2579	>	(m = rs.length) > 0 &&
2580	>	rs[j = (m - 1) & h] == null) {
2581	>	rs[j] = r;
2582	>	created = true;
2583	>	}
2584	>	} finally {
2585	>	cellsBusy = 0;
2586	>	}
2587	>	if (created)
2588	>	break;
2589	>	continue;           // Slot is now non-empty
2590	>	}
2591	>	}
2592	>	collide = false;
2593	>	}
2594	>	else if (!wasUncontended)       // CAS already known to fail
2595	>	wasUncontended = true;      // Continue after rehash
2596	>	else if (U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))
2597	>	break;
2598	>	else if (counterCells != cs || n >= NCPU)
2599	>	collide = false;            // At max size or stale
2600	>	else if (!collide)
2601	>	collide = true;
2602	>	else if (cellsBusy == 0 &&
2603	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2604	>	try {
2605	>	if (counterCells == cs) // Expand table unless stale
2606	>	counterCells = Arrays.copyOf(cs, n << 1);
2607	>	} finally {
2608	>	cellsBusy = 0;
2609	>	}
2610	>	collide = false;
2611	>	continue;                   // Retry with expanded table
2612	>	}
2613	>	h = ThreadLocalRandom.advanceProbe(h);
2614	>	}
2615	>	else if (cellsBusy == 0 && counterCells == cs &&
2616	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2617	>	boolean init = false;
2618	>	try {                           // Initialize table
2619	>	if (counterCells == cs) {
2620	>	CounterCell[] rs = new CounterCell[2];
2621	>	rs[h & 1] = new CounterCell(x);
2622	>	counterCells = rs;
2623	>	init = true;
2624	>	}
2625	>	} finally {
2626	>	cellsBusy = 0;
2627	>	}
2628	>	if (init)
2629	>	break;
2630	>	}
2631	>	else if (U.compareAndSetLong(this, BASECOUNT, v = baseCount, v + x))
2632	>	break;                          // Fall back on using base
2633	>	}
2634	>	}
2635	>
2636	>	/* ---------------- Conversion from/to TreeBins -------------- */
2637	>
2638	>	/**
2639	>	* Replaces all linked nodes in bin at given index unless table is
2640	>	* too small, in which case resizes instead.
2641	>	*/
2642	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2643	>	Node<K,V> b; int n;
2644	>	if (tab != null) {
2645	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2646	>	tryPresize(n << 1);
2647	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2648	>	synchronized (b) {
2649	>	if (tabAt(tab, index) == b) {
2650	>	TreeNode<K,V> hd = null, tl = null;
2651	>	for (Node<K,V> e = b; e != null; e = e.next) {
2652	>	TreeNode<K,V> p =
2653	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2654	>	null, null);
2655	>	if ((p.prev = tl) == null)
2656	>	hd = p;
2657	>	else
2658	>	tl.next = p;
2659	>	tl = p;
2660	>	}
2661	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2662	>	}
2663	>	}
2664	>	}
2665	>	}
2666	>	}
2667	>
2668	>	/**
2669	>	* Returns a list of non-TreeNodes replacing those in given list.
2670	>	*/
2671	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2672	>	Node<K,V> hd = null, tl = null;
2673	>	for (Node<K,V> q = b; q != null; q = q.next) {
2674	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2675	>	if (tl == null)
2676	>	hd = p;
2677	>	else
2678	>	tl.next = p;
2679	>	tl = p;
2680	>	}
2681	>	return hd;
2682	>	}
2683	>
2684	>	/* ---------------- TreeNodes -------------- */
2685	>
2686	>	/**
2687	>	* Nodes for use in TreeBins.
2688	>	*/
2689	>	static final class TreeNode<K,V> extends Node<K,V> {
2690	>	TreeNode<K,V> parent;  // red-black tree links
2691	>	TreeNode<K,V> left;
2692	>	TreeNode<K,V> right;
2693	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2694	>	boolean red;
2695	>
2696	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2697	>	TreeNode<K,V> parent) {
2698	>	super(hash, key, val, next);
2699	>	this.parent = parent;
2700	>	}
2701	>
2702	>	Node<K,V> find(int h, Object k) {
2703	>	return findTreeNode(h, k, null);
2704		}
2705
2706		/**
2707	<	* Sets nextEntry to first node of next non-empty table
2708	<	* (in backwards order, to simplify checks).
2707	>	* Returns the TreeNode (or null if not found) for the given key
2708	>	* starting at given root.
2709		*/
2710	<	final void advance() {
2711	<	for (;;) {
2712	<	if (nextTableIndex >= 0) {
2713	<	if ((nextEntry = entryAt(currentTable,
2714	<	nextTableIndex--)) != null)
2715	<	break;
2710	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2711	>	if (k != null) {
2712	>	TreeNode<K,V> p = this;
2713	>	do {
2714	>	int ph, dir; K pk; TreeNode<K,V> q;
2715	>	TreeNode<K,V> pl = p.left, pr = p.right;
2716	>	if ((ph = p.hash) > h)
2717	>	p = pl;
2718	>	else if (ph < h)
2719	>	p = pr;
2720	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2721	>	return p;
2722	>	else if (pl == null)
2723	>	p = pr;
2724	>	else if (pr == null)
2725	>	p = pl;
2726	>	else if ((kc != null ||
2727	>	(kc = comparableClassFor(k)) != null) &&
2728	>	(dir = compareComparables(kc, k, pk)) != 0)
2729	>	p = (dir < 0) ? pl : pr;
2730	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2731	>	return q;
2732	>	else
2733	>	p = pl;
2734	>	} while (p != null);
2735	>	}
2736	>	return null;
2737	>	}
2738	>	}
2739	>
2740	>	/* ---------------- TreeBins -------------- */
2741	>
2742	>	/**
2743	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2744	>	* keys or values, but instead point to list of TreeNodes and
2745	>	* their root. They also maintain a parasitic read-write lock
2746	>	* forcing writers (who hold bin lock) to wait for readers (who do
2747	>	* not) to complete before tree restructuring operations.
2748	>	*/
2749	>	static final class TreeBin<K,V> extends Node<K,V> {
2750	>	TreeNode<K,V> root;
2751	>	volatile TreeNode<K,V> first;
2752	>	volatile Thread waiter;
2753	>	volatile int lockState;
2754	>	// values for lockState
2755	>	static final int WRITER = 1; // set while holding write lock
2756	>	static final int WAITER = 2; // set when waiting for write lock
2757	>	static final int READER = 4; // increment value for setting read lock
2758	>
2759	>	/**
2760	>	* Tie-breaking utility for ordering insertions when equal
2761	>	* hashCodes and non-comparable. We don't require a total
2762	>	* order, just a consistent insertion rule to maintain
2763	>	* equivalence across rebalancings. Tie-breaking further than
2764	>	* necessary simplifies testing a bit.
2765	>	*/
2766	>	static int tieBreakOrder(Object a, Object b) {
2767	>	int d;
2768	>	if (a == null || b == null ||
2769	>	(d = a.getClass().getName().
2770	>	compareTo(b.getClass().getName())) == 0)
2771	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2772	>	-1 : 1);
2773	>	return d;
2774	>	}
2775	>
2776	>	/**
2777	>	* Creates bin with initial set of nodes headed by b.
2778	>	*/
2779	>	TreeBin(TreeNode<K,V> b) {
2780	>	super(TREEBIN, null, null);
2781	>	this.first = b;
2782	>	TreeNode<K,V> r = null;
2783	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2784	>	next = (TreeNode<K,V>)x.next;
2785	>	x.left = x.right = null;
2786	>	if (r == null) {
2787	>	x.parent = null;
2788	>	x.red = false;
2789	>	r = x;
2790		}
2791	<	else if (nextSegmentIndex >= 0) {
2792	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2793	<	if (seg != null && (currentTable = seg.table) != null)
2794	<	nextTableIndex = currentTable.length - 1;
2791	>	else {
2792	>	K k = x.key;
2793	>	int h = x.hash;
2794	>	Class<?> kc = null;
2795	>	for (TreeNode<K,V> p = r;;) {
2796	>	int dir, ph;
2797	>	K pk = p.key;
2798	>	if ((ph = p.hash) > h)
2799	>	dir = -1;
2800	>	else if (ph < h)
2801	>	dir = 1;
2802	>	else if ((kc == null &&
2803	>	(kc = comparableClassFor(k)) == null) ||
2804	>	(dir = compareComparables(kc, k, pk)) == 0)
2805	>	dir = tieBreakOrder(k, pk);
2806	>	TreeNode<K,V> xp = p;
2807	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2808	>	x.parent = xp;
2809	>	if (dir <= 0)
2810	>	xp.left = x;
2811	>	else
2812	>	xp.right = x;
2813	>	r = balanceInsertion(r, x);
2814	>	break;
2815	>	}
2816	>	}
2817		}
2818	<	else
2818	>	}
2819	>	this.root = r;
2820	>	assert checkInvariants(root);
2821	>	}
2822	>
2823	>	/**
2824	>	* Acquires write lock for tree restructuring.
2825	>	*/
2826	>	private final void lockRoot() {
2827	>	if (!U.compareAndSetInt(this, LOCKSTATE, 0, WRITER))
2828	>	contendedLock(); // offload to separate method
2829	>	}
2830	>
2831	>	/**
2832	>	* Releases write lock for tree restructuring.
2833	>	*/
2834	>	private final void unlockRoot() {
2835	>	lockState = 0;
2836	>	}
2837	>
2838	>	/**
2839	>	* Possibly blocks awaiting root lock.
2840	>	*/
2841	>	private final void contendedLock() {
2842	>	boolean waiting = false;
2843	>	for (int s;;) {
2844	>	if (((s = lockState) & ~WAITER) == 0) {
2845	>	if (U.compareAndSetInt(this, LOCKSTATE, s, WRITER)) {
2846	>	if (waiting)
2847	>	waiter = null;
2848	>	return;
2849	>	}
2850	>	}
2851	>	else if ((s & WAITER) == 0) {
2852	>	if (U.compareAndSetInt(this, LOCKSTATE, s, s | WAITER)) {
2853	>	waiting = true;
2854	>	waiter = Thread.currentThread();
2855	>	}
2856	>	}
2857	>	else if (waiting)
2858	>	LockSupport.park(this);
2859	>	}
2860	>	}
2861	>
2862	>	/**
2863	>	* Returns matching node or null if none. Tries to search
2864	>	* using tree comparisons from root, but continues linear
2865	>	* search when lock not available.
2866	>	*/
2867	>	final Node<K,V> find(int h, Object k) {
2868	>	if (k != null) {
2869	>	for (Node<K,V> e = first; e != null; ) {
2870	>	int s; K ek;
2871	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2872	>	if (e.hash == h &&
2873	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2874	>	return e;
2875	>	e = e.next;
2876	>	}
2877	>	else if (U.compareAndSetInt(this, LOCKSTATE, s,
2878	>	s + READER)) {
2879	>	TreeNode<K,V> r, p;
2880	>	try {
2881	>	p = ((r = root) == null ? null :
2882	>	r.findTreeNode(h, k, null));
2883	>	} finally {
2884	>	Thread w;
2885	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2886	>	(READER|WAITER) && (w = waiter) != null)
2887	>	LockSupport.unpark(w);
2888	>	}
2889	>	return p;
2890	>	}
2891	>	}
2892	>	}
2893	>	return null;
2894	>	}
2895	>
2896	>	/**
2897	>	* Finds or adds a node.
2898	>	* @return null if added
2899	>	*/
2900	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2901	>	Class<?> kc = null;
2902	>	boolean searched = false;
2903	>	for (TreeNode<K,V> p = root;;) {
2904	>	int dir, ph; K pk;
2905	>	if (p == null) {
2906	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2907		break;
2908	+	}
2909	+	else if ((ph = p.hash) > h)
2910	+	dir = -1;
2911	+	else if (ph < h)
2912	+	dir = 1;
2913	+	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2914	+	return p;
2915	+	else if ((kc == null &&
2916	+	(kc = comparableClassFor(k)) == null) ||
2917	+	(dir = compareComparables(kc, k, pk)) == 0) {
2918	+	if (!searched) {
2919	+	TreeNode<K,V> q, ch;
2920	+	searched = true;
2921	+	if (((ch = p.left) != null &&
2922	+	(q = ch.findTreeNode(h, k, kc)) != null) ||
2923	+	((ch = p.right) != null &&
2924	+	(q = ch.findTreeNode(h, k, kc)) != null))
2925	+	return q;
2926	+	}
2927	+	dir = tieBreakOrder(k, pk);
2928	+	}
2929	+
2930	+	TreeNode<K,V> xp = p;
2931	+	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2932	+	TreeNode<K,V> x, f = first;
2933	+	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2934	+	if (f != null)
2935	+	f.prev = x;
2936	+	if (dir <= 0)
2937	+	xp.left = x;
2938	+	else
2939	+	xp.right = x;
2940	+	if (!xp.red)
2941	+	x.red = true;
2942	+	else {
2943	+	lockRoot();
2944	+	try {
2945	+	root = balanceInsertion(root, x);
2946	+	} finally {
2947	+	unlockRoot();
2948	+	}
2949	+	}
2950	+	break;
2951	+	}
2952		}
2953	+	assert checkInvariants(root);
2954	+	return null;
2955		}
2956
2957	<	final HashEntry<K,V> nextEntry() {
2958	<	HashEntry<K,V> e = nextEntry;
2959	<	if (e == null)
2960	<	throw new NoSuchElementException();
2961	<	lastReturned = e; // cannot assign until after null check
2962	<	if ((nextEntry = e.next) == null)
2963	<	advance();
2964	<	return e;
2957	>	/**
2958	>	* Removes the given node, that must be present before this
2959	>	* call.  This is messier than typical red-black deletion code
2960	>	* because we cannot swap the contents of an interior node
2961	>	* with a leaf successor that is pinned by "next" pointers
2962	>	* that are accessible independently of lock. So instead we
2963	>	* swap the tree linkages.
2964	>	*
2965	>	* @return true if now too small, so should be untreeified
2966	>	*/
2967	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2968	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2969	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2970	>	TreeNode<K,V> r, rl;
2971	>	if (pred == null)
2972	>	first = next;
2973	>	else
2974	>	pred.next = next;
2975	>	if (next != null)
2976	>	next.prev = pred;
2977	>	if (first == null) {
2978	>	root = null;
2979	>	return true;
2980	>	}
2981	>	if ((r = root) == null || r.right == null || // too small
2982	>	(rl = r.left) == null || rl.left == null)
2983	>	return true;
2984	>	lockRoot();
2985	>	try {
2986	>	TreeNode<K,V> replacement;
2987	>	TreeNode<K,V> pl = p.left;
2988	>	TreeNode<K,V> pr = p.right;
2989	>	if (pl != null && pr != null) {
2990	>	TreeNode<K,V> s = pr, sl;
2991	>	while ((sl = s.left) != null) // find successor
2992	>	s = sl;
2993	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2994	>	TreeNode<K,V> sr = s.right;
2995	>	TreeNode<K,V> pp = p.parent;
2996	>	if (s == pr) { // p was s's direct parent
2997	>	p.parent = s;
2998	>	s.right = p;
2999	>	}
3000	>	else {
3001	>	TreeNode<K,V> sp = s.parent;
3002	>	if ((p.parent = sp) != null) {
3003	>	if (s == sp.left)
3004	>	sp.left = p;
3005	>	else
3006	>	sp.right = p;
3007	>	}
3008	>	if ((s.right = pr) != null)
3009	>	pr.parent = s;
3010	>	}
3011	>	p.left = null;
3012	>	if ((p.right = sr) != null)
3013	>	sr.parent = p;
3014	>	if ((s.left = pl) != null)
3015	>	pl.parent = s;
3016	>	if ((s.parent = pp) == null)
3017	>	r = s;
3018	>	else if (p == pp.left)
3019	>	pp.left = s;
3020	>	else
3021	>	pp.right = s;
3022	>	if (sr != null)
3023	>	replacement = sr;
3024	>	else
3025	>	replacement = p;
3026	>	}
3027	>	else if (pl != null)
3028	>	replacement = pl;
3029	>	else if (pr != null)
3030	>	replacement = pr;
3031	>	else
3032	>	replacement = p;
3033	>	if (replacement != p) {
3034	>	TreeNode<K,V> pp = replacement.parent = p.parent;
3035	>	if (pp == null)
3036	>	r = replacement;
3037	>	else if (p == pp.left)
3038	>	pp.left = replacement;
3039	>	else
3040	>	pp.right = replacement;
3041	>	p.left = p.right = p.parent = null;
3042	>	}
3043	>
3044	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3045	>
3046	>	if (p == replacement) {  // detach pointers
3047	>	TreeNode<K,V> pp;
3048	>	if ((pp = p.parent) != null) {
3049	>	if (p == pp.left)
3050	>	pp.left = null;
3051	>	else if (p == pp.right)
3052	>	pp.right = null;
3053	>	p.parent = null;
3054	>	}
3055	>	}
3056	>	} finally {
3057	>	unlockRoot();
3058	>	}
3059	>	assert checkInvariants(root);
3060	>	return false;
3061		}
3062
3063	<	public final boolean hasNext() { return nextEntry != null; }
3064	<	public final boolean hasMoreElements() { return nextEntry != null; }
3063	>	/* ------------------------------------------------------------ */
3064	>	// Red-black tree methods, all adapted from CLR
3065	>
3066	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3067	>	TreeNode<K,V> p) {
3068	>	TreeNode<K,V> r, pp, rl;
3069	>	if (p != null && (r = p.right) != null) {
3070	>	if ((rl = p.right = r.left) != null)
3071	>	rl.parent = p;
3072	>	if ((pp = r.parent = p.parent) == null)
3073	>	(root = r).red = false;
3074	>	else if (pp.left == p)
3075	>	pp.left = r;
3076	>	else
3077	>	pp.right = r;
3078	>	r.left = p;
3079	>	p.parent = r;
3080	>	}
3081	>	return root;
3082	>	}
3083	>
3084	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3085	>	TreeNode<K,V> p) {
3086	>	TreeNode<K,V> l, pp, lr;
3087	>	if (p != null && (l = p.left) != null) {
3088	>	if ((lr = p.left = l.right) != null)
3089	>	lr.parent = p;
3090	>	if ((pp = l.parent = p.parent) == null)
3091	>	(root = l).red = false;
3092	>	else if (pp.right == p)
3093	>	pp.right = l;
3094	>	else
3095	>	pp.left = l;
3096	>	l.right = p;
3097	>	p.parent = l;
3098	>	}
3099	>	return root;
3100	>	}
3101	>
3102	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3103	>	TreeNode<K,V> x) {
3104	>	x.red = true;
3105	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3106	>	if ((xp = x.parent) == null) {
3107	>	x.red = false;
3108	>	return x;
3109	>	}
3110	>	else if (!xp.red || (xpp = xp.parent) == null)
3111	>	return root;
3112	>	if (xp == (xppl = xpp.left)) {
3113	>	if ((xppr = xpp.right) != null && xppr.red) {
3114	>	xppr.red = false;
3115	>	xp.red = false;
3116	>	xpp.red = true;
3117	>	x = xpp;
3118	>	}
3119	>	else {
3120	>	if (x == xp.right) {
3121	>	root = rotateLeft(root, x = xp);
3122	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3123	>	}
3124	>	if (xp != null) {
3125	>	xp.red = false;
3126	>	if (xpp != null) {
3127	>	xpp.red = true;
3128	>	root = rotateRight(root, xpp);
3129	>	}
3130	>	}
3131	>	}
3132	>	}
3133	>	else {
3134	>	if (xppl != null && xppl.red) {
3135	>	xppl.red = false;
3136	>	xp.red = false;
3137	>	xpp.red = true;
3138	>	x = xpp;
3139	>	}
3140	>	else {
3141	>	if (x == xp.left) {
3142	>	root = rotateRight(root, x = xp);
3143	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3144	>	}
3145	>	if (xp != null) {
3146	>	xp.red = false;
3147	>	if (xpp != null) {
3148	>	xpp.red = true;
3149	>	root = rotateLeft(root, xpp);
3150	>	}
3151	>	}
3152	>	}
3153	>	}
3154	>	}
3155	>	}
3156	>
3157	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3158	>	TreeNode<K,V> x) {
3159	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3160	>	if (x == null || x == root)
3161	>	return root;
3162	>	else if ((xp = x.parent) == null) {
3163	>	x.red = false;
3164	>	return x;
3165	>	}
3166	>	else if (x.red) {
3167	>	x.red = false;
3168	>	return root;
3169	>	}
3170	>	else if ((xpl = xp.left) == x) {
3171	>	if ((xpr = xp.right) != null && xpr.red) {
3172	>	xpr.red = false;
3173	>	xp.red = true;
3174	>	root = rotateLeft(root, xp);
3175	>	xpr = (xp = x.parent) == null ? null : xp.right;
3176	>	}
3177	>	if (xpr == null)
3178	>	x = xp;
3179	>	else {
3180	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3181	>	if ((sr == null || !sr.red) &&
3182	>	(sl == null || !sl.red)) {
3183	>	xpr.red = true;
3184	>	x = xp;
3185	>	}
3186	>	else {
3187	>	if (sr == null || !sr.red) {
3188	>	if (sl != null)
3189	>	sl.red = false;
3190	>	xpr.red = true;
3191	>	root = rotateRight(root, xpr);
3192	>	xpr = (xp = x.parent) == null ?
3193	>	null : xp.right;
3194	>	}
3195	>	if (xpr != null) {
3196	>	xpr.red = (xp == null) ? false : xp.red;
3197	>	if ((sr = xpr.right) != null)
3198	>	sr.red = false;
3199	>	}
3200	>	if (xp != null) {
3201	>	xp.red = false;
3202	>	root = rotateLeft(root, xp);
3203	>	}
3204	>	x = root;
3205	>	}
3206	>	}
3207	>	}
3208	>	else { // symmetric
3209	>	if (xpl != null && xpl.red) {
3210	>	xpl.red = false;
3211	>	xp.red = true;
3212	>	root = rotateRight(root, xp);
3213	>	xpl = (xp = x.parent) == null ? null : xp.left;
3214	>	}
3215	>	if (xpl == null)
3216	>	x = xp;
3217	>	else {
3218	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3219	>	if ((sl == null || !sl.red) &&
3220	>	(sr == null || !sr.red)) {
3221	>	xpl.red = true;
3222	>	x = xp;
3223	>	}
3224	>	else {
3225	>	if (sl == null || !sl.red) {
3226	>	if (sr != null)
3227	>	sr.red = false;
3228	>	xpl.red = true;
3229	>	root = rotateLeft(root, xpl);
3230	>	xpl = (xp = x.parent) == null ?
3231	>	null : xp.left;
3232	>	}
3233	>	if (xpl != null) {
3234	>	xpl.red = (xp == null) ? false : xp.red;
3235	>	if ((sl = xpl.left) != null)
3236	>	sl.red = false;
3237	>	}
3238	>	if (xp != null) {
3239	>	xp.red = false;
3240	>	root = rotateRight(root, xp);
3241	>	}
3242	>	x = root;
3243	>	}
3244	>	}
3245	>	}
3246	>	}
3247	>	}
3248	>
3249	>	/**
3250	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3251	>	*/
3252	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3253	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3254	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3255	>	if (tb != null && tb.next != t)
3256	>	return false;
3257	>	if (tn != null && tn.prev != t)
3258	>	return false;
3259	>	if (tp != null && t != tp.left && t != tp.right)
3260	>	return false;
3261	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3262	>	return false;
3263	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3264	>	return false;
3265	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3266	>	return false;
3267	>	if (tl != null && !checkInvariants(tl))
3268	>	return false;
3269	>	if (tr != null && !checkInvariants(tr))
3270	>	return false;
3271	>	return true;
3272	>	}
3273	>
3274	>	private static final Unsafe U = Unsafe.getUnsafe();
3275	>	private static final long LOCKSTATE;
3276	>	static {
3277	>	try {
3278	>	LOCKSTATE = U.objectFieldOffset
3279	>	(TreeBin.class.getDeclaredField("lockState"));
3280	>	} catch (ReflectiveOperationException e) {
3281	>	throw new ExceptionInInitializerError(e);
3282	>	}
3283	>	}
3284	>	}
3285	>
3286	>	/* ----------------Table Traversal -------------- */
3287	>
3288	>	/**
3289	>	* Records the table, its length, and current traversal index for a
3290	>	* traverser that must process a region of a forwarded table before
3291	>	* proceeding with current table.
3292	>	*/
3293	>	static final class TableStack<K,V> {
3294	>	int length;
3295	>	int index;
3296	>	Node<K,V>[] tab;
3297	>	TableStack<K,V> next;
3298	>	}
3299	>
3300	>	/**
3301	>	* Encapsulates traversal for methods such as containsValue; also
3302	>	* serves as a base class for other iterators and spliterators.
3303	>	*
3304	>	* Method advance visits once each still-valid node that was
3305	>	* reachable upon iterator construction. It might miss some that
3306	>	* were added to a bin after the bin was visited, which is OK wrt
3307	>	* consistency guarantees. Maintaining this property in the face
3308	>	* of possible ongoing resizes requires a fair amount of
3309	>	* bookkeeping state that is difficult to optimize away amidst
3310	>	* volatile accesses.  Even so, traversal maintains reasonable
3311	>	* throughput.
3312	>	*
3313	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3314	>	* However, if the table has been resized, then all future steps
3315	>	* must traverse both the bin at the current index as well as at
3316	>	* (index + baseSize); and so on for further resizings. To
3317	>	* paranoically cope with potential sharing by users of iterators
3318	>	* across threads, iteration terminates if a bounds checks fails
3319	>	* for a table read.
3320	>	*/
3321	>	static class Traverser<K,V> {
3322	>	Node<K,V>[] tab;        // current table; updated if resized
3323	>	Node<K,V> next;         // the next entry to use
3324	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3325	>	int index;              // index of bin to use next
3326	>	int baseIndex;          // current index of initial table
3327	>	int baseLimit;          // index bound for initial table
3328	>	final int baseSize;     // initial table size
3329	>
3330	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3331	>	this.tab = tab;
3332	>	this.baseSize = size;
3333	>	this.baseIndex = this.index = index;
3334	>	this.baseLimit = limit;
3335	>	this.next = null;
3336	>	}
3337	>
3338	>	/**
3339	>	* Advances if possible, returning next valid node, or null if none.
3340	>	*/
3341	>	final Node<K,V> advance() {
3342	>	Node<K,V> e;
3343	>	if ((e = next) != null)
3344	>	e = e.next;
3345	>	for (;;) {
3346	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3347	>	if (e != null)
3348	>	return next = e;
3349	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3350	>	(n = t.length) <= (i = index) || i < 0)
3351	>	return next = null;
3352	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3353	>	if (e instanceof ForwardingNode) {
3354	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3355	>	e = null;
3356	>	pushState(t, i, n);
3357	>	continue;
3358	>	}
3359	>	else if (e instanceof TreeBin)
3360	>	e = ((TreeBin<K,V>)e).first;
3361	>	else
3362	>	e = null;
3363	>	}
3364	>	if (stack != null)
3365	>	recoverState(n);
3366	>	else if ((index = i + baseSize) >= n)
3367	>	index = ++baseIndex; // visit upper slots if present
3368	>	}
3369	>	}
3370	>
3371	>	/**
3372	>	* Saves traversal state upon encountering a forwarding node.
3373	>	*/
3374	>	private void pushState(Node<K,V>[] t, int i, int n) {
3375	>	TableStack<K,V> s = spare;  // reuse if possible
3376	>	if (s != null)
3377	>	spare = s.next;
3378	>	else
3379	>	s = new TableStack<K,V>();
3380	>	s.tab = t;
3381	>	s.length = n;
3382	>	s.index = i;
3383	>	s.next = stack;
3384	>	stack = s;
3385	>	}
3386	>
3387	>	/**
3388	>	* Possibly pops traversal state.
3389	>	*
3390	>	* @param n length of current table
3391	>	*/
3392	>	private void recoverState(int n) {
3393	>	TableStack<K,V> s; int len;
3394	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3395	>	n = len;
3396	>	index = s.index;
3397	>	tab = s.tab;
3398	>	s.tab = null;
3399	>	TableStack<K,V> next = s.next;
3400	>	s.next = spare; // save for reuse
3401	>	stack = next;
3402	>	spare = s;
3403	>	}
3404	>	if (s == null && (index += baseSize) >= n)
3405	>	index = ++baseIndex;
3406	>	}
3407	>	}
3408	>
3409	>	/**
3410	>	* Base of key, value, and entry Iterators. Adds fields to
3411	>	* Traverser to support iterator.remove.
3412	>	*/
3413	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3414	>	final ConcurrentHashMap<K,V> map;
3415	>	Node<K,V> lastReturned;
3416	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3417	>	ConcurrentHashMap<K,V> map) {
3418	>	super(tab, size, index, limit);
3419	>	this.map = map;
3420	>	advance();
3421	>	}
3422	>
3423	>	public final boolean hasNext() { return next != null; }
3424	>	public final boolean hasMoreElements() { return next != null; }
3425
3426		public final void remove() {
3427	<	if (lastReturned == null)
3427	>	Node<K,V> p;
3428	>	if ((p = lastReturned) == null)
3429		throw new IllegalStateException();
1263	–	ConcurrentHashMap.this.remove(lastReturned.key);
3430		lastReturned = null;
3431	+	map.replaceNode(p.key, null, null);
3432	+	}
3433	+	}
3434	+
3435	+	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3436	+	implements Iterator<K>, Enumeration<K> {
3437	+	KeyIterator(Node<K,V>[] tab, int size, int index, int limit,
3438	+	ConcurrentHashMap<K,V> map) {
3439	+	super(tab, size, index, limit, map);
3440	+	}
3441	+
3442	+	public final K next() {
3443	+	Node<K,V> p;
3444	+	if ((p = next) == null)
3445	+	throw new NoSuchElementException();
3446	+	K k = p.key;
3447	+	lastReturned = p;
3448	+	advance();
3449	+	return k;
3450		}
3451	+
3452	+	public final K nextElement() { return next(); }
3453		}
3454
3455	<	final class KeyIterator
3456	<	extends HashIterator
3457	<	implements Iterator<K>, Enumeration<K>
3458	<	{
3459	<	public final K next()        { return super.nextEntry().key; }
3460	<	public final K nextElement() { return super.nextEntry().key; }
3461	<	}
3462	<
3463	<	final class ValueIterator
3464	<	extends HashIterator
3465	<	implements Iterator<V>, Enumeration<V>
3466	<	{
3467	<	public final V next()        { return super.nextEntry().value; }
3468	<	public final V nextElement() { return super.nextEntry().value; }
3455	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3456	>	implements Iterator<V>, Enumeration<V> {
3457	>	ValueIterator(Node<K,V>[] tab, int size, int index, int limit,
3458	>	ConcurrentHashMap<K,V> map) {
3459	>	super(tab, size, index, limit, map);
3460	>	}
3461	>
3462	>	public final V next() {
3463	>	Node<K,V> p;
3464	>	if ((p = next) == null)
3465	>	throw new NoSuchElementException();
3466	>	V v = p.val;
3467	>	lastReturned = p;
3468	>	advance();
3469	>	return v;
3470	>	}
3471	>
3472	>	public final V nextElement() { return next(); }
3473	>	}
3474	>
3475	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3476	>	implements Iterator<Map.Entry<K,V>> {
3477	>	EntryIterator(Node<K,V>[] tab, int size, int index, int limit,
3478	>	ConcurrentHashMap<K,V> map) {
3479	>	super(tab, size, index, limit, map);
3480	>	}
3481	>
3482	>	public final Map.Entry<K,V> next() {
3483	>	Node<K,V> p;
3484	>	if ((p = next) == null)
3485	>	throw new NoSuchElementException();
3486	>	K k = p.key;
3487	>	V v = p.val;
3488	>	lastReturned = p;
3489	>	advance();
3490	>	return new MapEntry<K,V>(k, v, map);
3491	>	}
3492		}
3493
3494		/**
3495	<	* Custom Entry class used by EntryIterator.next(), that relays
3496	<	* setValue changes to the underlying map.
3497	<	*/
3498	<	final class WriteThroughEntry
3499	<	extends AbstractMap.SimpleEntry<K,V>
3500	<	{
3501	<	WriteThroughEntry(K k, V v) {
3502	<	super(k,v);
3495	>	* Exported Entry for EntryIterator.
3496	>	*/
3497	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3498	>	final K key; // non-null
3499	>	V val;       // non-null
3500	>	final ConcurrentHashMap<K,V> map;
3501	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3502	>	this.key = key;
3503	>	this.val = val;
3504	>	this.map = map;
3505	>	}
3506	>	public K getKey()        { return key; }
3507	>	public V getValue()      { return val; }
3508	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3509	>	public String toString() {
3510	>	return Helpers.mapEntryToString(key, val);
3511	>	}
3512	>
3513	>	public boolean equals(Object o) {
3514	>	Object k, v; Map.Entry<?,?> e;
3515	>	return ((o instanceof Map.Entry) &&
3516	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3517	>	(v = e.getValue()) != null &&
3518	>	(k == key || k.equals(key)) &&
3519	>	(v == val || v.equals(val)));
3520		}
3521
3522		/**
3523		* Sets our entry's value and writes through to the map. The
3524	<	* value to return is somewhat arbitrary here. Since a
3525	<	* WriteThroughEntry does not necessarily track asynchronous
3526	<	* changes, the most recent "previous" value could be
3527	<	* different from what we return (or could even have been
3528	<	* removed in which case the put will re-establish). We do not
1302	<	* and cannot guarantee more.
3524	>	* value to return is somewhat arbitrary here. Since we do not
3525	>	* necessarily track asynchronous changes, the most recent
3526	>	* "previous" value could be different from what we return (or
3527	>	* could even have been removed, in which case the put will
3528	>	* re-establish). We do not and cannot guarantee more.
3529		*/
3530		public V setValue(V value) {
3531		if (value == null) throw new NullPointerException();
3532	<	V v = super.setValue(value);
3533	<	ConcurrentHashMap.this.put(getKey(), value);
3532	>	V v = val;
3533	>	val = value;
3534	>	map.put(key, value);
3535		return v;
3536		}
3537		}
3538
3539	<	final class EntryIterator
3540	<	extends HashIterator
3541	<	implements Iterator<Entry<K,V>>
3542	<	{
3543	<	public Map.Entry<K,V> next() {
3544	<	HashEntry<K,V> e = super.nextEntry();
3545	<	return new WriteThroughEntry(e.key, e.value);
3539	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3540	>	implements Spliterator<K> {
3541	>	long est;               // size estimate
3542	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3543	>	long est) {
3544	>	super(tab, size, index, limit);
3545	>	this.est = est;
3546	>	}
3547	>
3548	>	public KeySpliterator<K,V> trySplit() {
3549	>	int i, f, h;
3550	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3551	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3552	>	f, est >>>= 1);
3553	>	}
3554	>
3555	>	public void forEachRemaining(Consumer<? super K> action) {
3556	>	if (action == null) throw new NullPointerException();
3557	>	for (Node<K,V> p; (p = advance()) != null;)
3558	>	action.accept(p.key);
3559	>	}
3560	>
3561	>	public boolean tryAdvance(Consumer<? super K> action) {
3562	>	if (action == null) throw new NullPointerException();
3563	>	Node<K,V> p;
3564	>	if ((p = advance()) == null)
3565	>	return false;
3566	>	action.accept(p.key);
3567	>	return true;
3568	>	}
3569	>
3570	>	public long estimateSize() { return est; }
3571	>
3572	>	public int characteristics() {
3573	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3574	>	Spliterator.NONNULL;
3575		}
3576		}
3577
3578	<	final class KeySet extends AbstractSet<K> {
3579	<	public Iterator<K> iterator() {
3580	<	return new KeyIterator();
3578	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3579	>	implements Spliterator<V> {
3580	>	long est;               // size estimate
3581	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3582	>	long est) {
3583	>	super(tab, size, index, limit);
3584	>	this.est = est;
3585	>	}
3586	>
3587	>	public ValueSpliterator<K,V> trySplit() {
3588	>	int i, f, h;
3589	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3590	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3591	>	f, est >>>= 1);
3592		}
3593	<	public int size() {
3594	<	return ConcurrentHashMap.this.size();
3593	>
3594	>	public void forEachRemaining(Consumer<? super V> action) {
3595	>	if (action == null) throw new NullPointerException();
3596	>	for (Node<K,V> p; (p = advance()) != null;)
3597	>	action.accept(p.val);
3598		}
3599	<	public boolean isEmpty() {
3600	<	return ConcurrentHashMap.this.isEmpty();
3599	>
3600	>	public boolean tryAdvance(Consumer<? super V> action) {
3601	>	if (action == null) throw new NullPointerException();
3602	>	Node<K,V> p;
3603	>	if ((p = advance()) == null)
3604	>	return false;
3605	>	action.accept(p.val);
3606	>	return true;
3607		}
3608	<	public boolean contains(Object o) {
3609	<	return ConcurrentHashMap.this.containsKey(o);
3608	>
3609	>	public long estimateSize() { return est; }
3610	>
3611	>	public int characteristics() {
3612	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3613		}
3614	<	public boolean remove(Object o) {
3615	<	return ConcurrentHashMap.this.remove(o) != null;
3614	>	}
3615	>
3616	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3617	>	implements Spliterator<Map.Entry<K,V>> {
3618	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3619	>	long est;               // size estimate
3620	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3621	>	long est, ConcurrentHashMap<K,V> map) {
3622	>	super(tab, size, index, limit);
3623	>	this.map = map;
3624	>	this.est = est;
3625		}
3626	<	public void clear() {
3627	<	ConcurrentHashMap.this.clear();
3626	>
3627	>	public EntrySpliterator<K,V> trySplit() {
3628	>	int i, f, h;
3629	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3630	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3631	>	f, est >>>= 1, map);
3632		}
3633	+
3634	+	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3635	+	if (action == null) throw new NullPointerException();
3636	+	for (Node<K,V> p; (p = advance()) != null; )
3637	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3638	+	}
3639	+
3640	+	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3641	+	if (action == null) throw new NullPointerException();
3642	+	Node<K,V> p;
3643	+	if ((p = advance()) == null)
3644	+	return false;
3645	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3646	+	return true;
3647	+	}
3648	+
3649	+	public long estimateSize() { return est; }
3650	+
3651	+	public int characteristics() {
3652	+	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3653	+	Spliterator.NONNULL;
3654	+	}
3655	+	}
3656	+
3657	+	// Parallel bulk operations
3658	+
3659	+	/**
3660	+	* Computes initial batch value for bulk tasks. The returned value
3661	+	* is approximately exp2 of the number of times (minus one) to
3662	+	* split task by two before executing leaf action. This value is
3663	+	* faster to compute and more convenient to use as a guide to
3664	+	* splitting than is the depth, since it is used while dividing by
3665	+	* two anyway.
3666	+	*/
3667	+	final int batchFor(long b) {
3668	+	long n;
3669	+	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3670	+	return 0;
3671	+	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3672	+	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3673	+	}
3674	+
3675	+	/**
3676	+	* Performs the given action for each (key, value).
3677	+	*
3678	+	* @param parallelismThreshold the (estimated) number of elements
3679	+	* needed for this operation to be executed in parallel
3680	+	* @param action the action
3681	+	* @since 1.8
3682	+	*/
3683	+	public void forEach(long parallelismThreshold,
3684	+	BiConsumer<? super K,? super V> action) {
3685	+	if (action == null) throw new NullPointerException();
3686	+	new ForEachMappingTask<K,V>
3687	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3688	+	action).invoke();
3689	+	}
3690	+
3691	+	/**
3692	+	* Performs the given action for each non-null transformation
3693	+	* of each (key, value).
3694	+	*
3695	+	* @param parallelismThreshold the (estimated) number of elements
3696	+	* needed for this operation to be executed in parallel
3697	+	* @param transformer a function returning the transformation
3698	+	* for an element, or null if there is no transformation (in
3699	+	* which case the action is not applied)
3700	+	* @param action the action
3701	+	* @param <U> the return type of the transformer
3702	+	* @since 1.8
3703	+	*/
3704	+	public <U> void forEach(long parallelismThreshold,
3705	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3706	+	Consumer<? super U> action) {
3707	+	if (transformer == null || action == null)
3708	+	throw new NullPointerException();
3709	+	new ForEachTransformedMappingTask<K,V,U>
3710	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3711	+	transformer, action).invoke();
3712	+	}
3713	+
3714	+	/**
3715	+	* Returns a non-null result from applying the given search
3716	+	* function on each (key, value), or null if none.  Upon
3717	+	* success, further element processing is suppressed and the
3718	+	* results of any other parallel invocations of the search
3719	+	* function are ignored.
3720	+	*
3721	+	* @param parallelismThreshold the (estimated) number of elements
3722	+	* needed for this operation to be executed in parallel
3723	+	* @param searchFunction a function returning a non-null
3724	+	* result on success, else null
3725	+	* @param <U> the return type of the search function
3726	+	* @return a non-null result from applying the given search
3727	+	* function on each (key, value), or null if none
3728	+	* @since 1.8
3729	+	*/
3730	+	public <U> U search(long parallelismThreshold,
3731	+	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3732	+	if (searchFunction == null) throw new NullPointerException();
3733	+	return new SearchMappingsTask<K,V,U>
3734	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3735	+	searchFunction, new AtomicReference<U>()).invoke();
3736	+	}
3737	+
3738	+	/**
3739	+	* Returns the result of accumulating the given transformation
3740	+	* of all (key, value) pairs using the given reducer to
3741	+	* combine values, or null if none.
3742	+	*
3743	+	* @param parallelismThreshold the (estimated) number of elements
3744	+	* needed for this operation to be executed in parallel
3745	+	* @param transformer a function returning the transformation
3746	+	* for an element, or null if there is no transformation (in
3747	+	* which case it is not combined)
3748	+	* @param reducer a commutative associative combining function
3749	+	* @param <U> the return type of the transformer
3750	+	* @return the result of accumulating the given transformation
3751	+	* of all (key, value) pairs
3752	+	* @since 1.8
3753	+	*/
3754	+	public <U> U reduce(long parallelismThreshold,
3755	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3756	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3757	+	if (transformer == null || reducer == null)
3758	+	throw new NullPointerException();
3759	+	return new MapReduceMappingsTask<K,V,U>
3760	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3761	+	null, transformer, reducer).invoke();
3762	+	}
3763	+
3764	+	/**
3765	+	* Returns the result of accumulating the given transformation
3766	+	* of all (key, value) pairs using the given reducer to
3767	+	* combine values, and the given basis as an identity value.
3768	+	*
3769	+	* @param parallelismThreshold the (estimated) number of elements
3770	+	* needed for this operation to be executed in parallel
3771	+	* @param transformer a function returning the transformation
3772	+	* for an element
3773	+	* @param basis the identity (initial default value) for the reduction
3774	+	* @param reducer a commutative associative combining function
3775	+	* @return the result of accumulating the given transformation
3776	+	* of all (key, value) pairs
3777	+	* @since 1.8
3778	+	*/
3779	+	public double reduceToDouble(long parallelismThreshold,
3780	+	ToDoubleBiFunction<? super K, ? super V> transformer,
3781	+	double basis,
3782	+	DoubleBinaryOperator reducer) {
3783	+	if (transformer == null || reducer == null)
3784	+	throw new NullPointerException();
3785	+	return new MapReduceMappingsToDoubleTask<K,V>
3786	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3787	+	null, transformer, basis, reducer).invoke();
3788		}
3789
3790	<	final class Values extends AbstractCollection<V> {
3791	<	public Iterator<V> iterator() {
3792	<	return new ValueIterator();
3790	>	/**
3791	>	* Returns the result of accumulating the given transformation
3792	>	* of all (key, value) pairs using the given reducer to
3793	>	* combine values, and the given basis as an identity value.
3794	>	*
3795	>	* @param parallelismThreshold the (estimated) number of elements
3796	>	* needed for this operation to be executed in parallel
3797	>	* @param transformer a function returning the transformation
3798	>	* for an element
3799	>	* @param basis the identity (initial default value) for the reduction
3800	>	* @param reducer a commutative associative combining function
3801	>	* @return the result of accumulating the given transformation
3802	>	* of all (key, value) pairs
3803	>	* @since 1.8
3804	>	*/
3805	>	public long reduceToLong(long parallelismThreshold,
3806	>	ToLongBiFunction<? super K, ? super V> transformer,
3807	>	long basis,
3808	>	LongBinaryOperator reducer) {
3809	>	if (transformer == null || reducer == null)
3810	>	throw new NullPointerException();
3811	>	return new MapReduceMappingsToLongTask<K,V>
3812	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3813	>	null, transformer, basis, reducer).invoke();
3814	>	}
3815	>
3816	>	/**
3817	>	* Returns the result of accumulating the given transformation
3818	>	* of all (key, value) pairs using the given reducer to
3819	>	* combine values, and the given basis as an identity value.
3820	>	*
3821	>	* @param parallelismThreshold the (estimated) number of elements
3822	>	* needed for this operation to be executed in parallel
3823	>	* @param transformer a function returning the transformation
3824	>	* for an element
3825	>	* @param basis the identity (initial default value) for the reduction
3826	>	* @param reducer a commutative associative combining function
3827	>	* @return the result of accumulating the given transformation
3828	>	* of all (key, value) pairs
3829	>	* @since 1.8
3830	>	*/
3831	>	public int reduceToInt(long parallelismThreshold,
3832	>	ToIntBiFunction<? super K, ? super V> transformer,
3833	>	int basis,
3834	>	IntBinaryOperator reducer) {
3835	>	if (transformer == null || reducer == null)
3836	>	throw new NullPointerException();
3837	>	return new MapReduceMappingsToIntTask<K,V>
3838	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3839	>	null, transformer, basis, reducer).invoke();
3840	>	}
3841	>
3842	>	/**
3843	>	* Performs the given action for each key.
3844	>	*
3845	>	* @param parallelismThreshold the (estimated) number of elements
3846	>	* needed for this operation to be executed in parallel
3847	>	* @param action the action
3848	>	* @since 1.8
3849	>	*/
3850	>	public void forEachKey(long parallelismThreshold,
3851	>	Consumer<? super K> action) {
3852	>	if (action == null) throw new NullPointerException();
3853	>	new ForEachKeyTask<K,V>
3854	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3855	>	action).invoke();
3856	>	}
3857	>
3858	>	/**
3859	>	* Performs the given action for each non-null transformation
3860	>	* of each key.
3861	>	*
3862	>	* @param parallelismThreshold the (estimated) number of elements
3863	>	* needed for this operation to be executed in parallel
3864	>	* @param transformer a function returning the transformation
3865	>	* for an element, or null if there is no transformation (in
3866	>	* which case the action is not applied)
3867	>	* @param action the action
3868	>	* @param <U> the return type of the transformer
3869	>	* @since 1.8
3870	>	*/
3871	>	public <U> void forEachKey(long parallelismThreshold,
3872	>	Function<? super K, ? extends U> transformer,
3873	>	Consumer<? super U> action) {
3874	>	if (transformer == null || action == null)
3875	>	throw new NullPointerException();
3876	>	new ForEachTransformedKeyTask<K,V,U>
3877	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3878	>	transformer, action).invoke();
3879	>	}
3880	>
3881	>	/**
3882	>	* Returns a non-null result from applying the given search
3883	>	* function on each key, or null if none. Upon success,
3884	>	* further element processing is suppressed and the results of
3885	>	* any other parallel invocations of the search function are
3886	>	* ignored.
3887	>	*
3888	>	* @param parallelismThreshold the (estimated) number of elements
3889	>	* needed for this operation to be executed in parallel
3890	>	* @param searchFunction a function returning a non-null
3891	>	* result on success, else null
3892	>	* @param <U> the return type of the search function
3893	>	* @return a non-null result from applying the given search
3894	>	* function on each key, or null if none
3895	>	* @since 1.8
3896	>	*/
3897	>	public <U> U searchKeys(long parallelismThreshold,
3898	>	Function<? super K, ? extends U> searchFunction) {
3899	>	if (searchFunction == null) throw new NullPointerException();
3900	>	return new SearchKeysTask<K,V,U>
3901	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3902	>	searchFunction, new AtomicReference<U>()).invoke();
3903	>	}
3904	>
3905	>	/**
3906	>	* Returns the result of accumulating all keys using the given
3907	>	* reducer to combine values, or null if none.
3908	>	*
3909	>	* @param parallelismThreshold the (estimated) number of elements
3910	>	* needed for this operation to be executed in parallel
3911	>	* @param reducer a commutative associative combining function
3912	>	* @return the result of accumulating all keys using the given
3913	>	* reducer to combine values, or null if none
3914	>	* @since 1.8
3915	>	*/
3916	>	public K reduceKeys(long parallelismThreshold,
3917	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3918	>	if (reducer == null) throw new NullPointerException();
3919	>	return new ReduceKeysTask<K,V>
3920	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3921	>	null, reducer).invoke();
3922	>	}
3923	>
3924	>	/**
3925	>	* Returns the result of accumulating the given transformation
3926	>	* of all keys using the given reducer to combine values, or
3927	>	* null if none.
3928	>	*
3929	>	* @param parallelismThreshold the (estimated) number of elements
3930	>	* needed for this operation to be executed in parallel
3931	>	* @param transformer a function returning the transformation
3932	>	* for an element, or null if there is no transformation (in
3933	>	* which case it is not combined)
3934	>	* @param reducer a commutative associative combining function
3935	>	* @param <U> the return type of the transformer
3936	>	* @return the result of accumulating the given transformation
3937	>	* of all keys
3938	>	* @since 1.8
3939	>	*/
3940	>	public <U> U reduceKeys(long parallelismThreshold,
3941	>	Function<? super K, ? extends U> transformer,
3942	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3943	>	if (transformer == null || reducer == null)
3944	>	throw new NullPointerException();
3945	>	return new MapReduceKeysTask<K,V,U>
3946	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3947	>	null, transformer, reducer).invoke();
3948	>	}
3949	>
3950	>	/**
3951	>	* Returns the result of accumulating the given transformation
3952	>	* of all keys using the given reducer to combine values, and
3953	>	* the given basis as an identity value.
3954	>	*
3955	>	* @param parallelismThreshold the (estimated) number of elements
3956	>	* needed for this operation to be executed in parallel
3957	>	* @param transformer a function returning the transformation
3958	>	* for an element
3959	>	* @param basis the identity (initial default value) for the reduction
3960	>	* @param reducer a commutative associative combining function
3961	>	* @return the result of accumulating the given transformation
3962	>	* of all keys
3963	>	* @since 1.8
3964	>	*/
3965	>	public double reduceKeysToDouble(long parallelismThreshold,
3966	>	ToDoubleFunction<? super K> transformer,
3967	>	double basis,
3968	>	DoubleBinaryOperator reducer) {
3969	>	if (transformer == null || reducer == null)
3970	>	throw new NullPointerException();
3971	>	return new MapReduceKeysToDoubleTask<K,V>
3972	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3973	>	null, transformer, basis, reducer).invoke();
3974	>	}
3975	>
3976	>	/**
3977	>	* Returns the result of accumulating the given transformation
3978	>	* of all keys using the given reducer to combine values, and
3979	>	* the given basis as an identity value.
3980	>	*
3981	>	* @param parallelismThreshold the (estimated) number of elements
3982	>	* needed for this operation to be executed in parallel
3983	>	* @param transformer a function returning the transformation
3984	>	* for an element
3985	>	* @param basis the identity (initial default value) for the reduction
3986	>	* @param reducer a commutative associative combining function
3987	>	* @return the result of accumulating the given transformation
3988	>	* of all keys
3989	>	* @since 1.8
3990	>	*/
3991	>	public long reduceKeysToLong(long parallelismThreshold,
3992	>	ToLongFunction<? super K> transformer,
3993	>	long basis,
3994	>	LongBinaryOperator reducer) {
3995	>	if (transformer == null || reducer == null)
3996	>	throw new NullPointerException();
3997	>	return new MapReduceKeysToLongTask<K,V>
3998	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3999	>	null, transformer, basis, reducer).invoke();
4000	>	}
4001	>
4002	>	/**
4003	>	* Returns the result of accumulating the given transformation
4004	>	* of all keys using the given reducer to combine values, and
4005	>	* the given basis as an identity value.
4006	>	*
4007	>	* @param parallelismThreshold the (estimated) number of elements
4008	>	* needed for this operation to be executed in parallel
4009	>	* @param transformer a function returning the transformation
4010	>	* for an element
4011	>	* @param basis the identity (initial default value) for the reduction
4012	>	* @param reducer a commutative associative combining function
4013	>	* @return the result of accumulating the given transformation
4014	>	* of all keys
4015	>	* @since 1.8
4016	>	*/
4017	>	public int reduceKeysToInt(long parallelismThreshold,
4018	>	ToIntFunction<? super K> transformer,
4019	>	int basis,
4020	>	IntBinaryOperator reducer) {
4021	>	if (transformer == null || reducer == null)
4022	>	throw new NullPointerException();
4023	>	return new MapReduceKeysToIntTask<K,V>
4024	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4025	>	null, transformer, basis, reducer).invoke();
4026	>	}
4027	>
4028	>	/**
4029	>	* Performs the given action for each value.
4030	>	*
4031	>	* @param parallelismThreshold the (estimated) number of elements
4032	>	* needed for this operation to be executed in parallel
4033	>	* @param action the action
4034	>	* @since 1.8
4035	>	*/
4036	>	public void forEachValue(long parallelismThreshold,
4037	>	Consumer<? super V> action) {
4038	>	if (action == null)
4039	>	throw new NullPointerException();
4040	>	new ForEachValueTask<K,V>
4041	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4042	>	action).invoke();
4043	>	}
4044	>
4045	>	/**
4046	>	* Performs the given action for each non-null transformation
4047	>	* of each value.
4048	>	*
4049	>	* @param parallelismThreshold the (estimated) number of elements
4050	>	* needed for this operation to be executed in parallel
4051	>	* @param transformer a function returning the transformation
4052	>	* for an element, or null if there is no transformation (in
4053	>	* which case the action is not applied)
4054	>	* @param action the action
4055	>	* @param <U> the return type of the transformer
4056	>	* @since 1.8
4057	>	*/
4058	>	public <U> void forEachValue(long parallelismThreshold,
4059	>	Function<? super V, ? extends U> transformer,
4060	>	Consumer<? super U> action) {
4061	>	if (transformer == null || action == null)
4062	>	throw new NullPointerException();
4063	>	new ForEachTransformedValueTask<K,V,U>
4064	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4065	>	transformer, action).invoke();
4066	>	}
4067	>
4068	>	/**
4069	>	* Returns a non-null result from applying the given search
4070	>	* function on each value, or null if none.  Upon success,
4071	>	* further element processing is suppressed and the results of
4072	>	* any other parallel invocations of the search function are
4073	>	* ignored.
4074	>	*
4075	>	* @param parallelismThreshold the (estimated) number of elements
4076	>	* needed for this operation to be executed in parallel
4077	>	* @param searchFunction a function returning a non-null
4078	>	* result on success, else null
4079	>	* @param <U> the return type of the search function
4080	>	* @return a non-null result from applying the given search
4081	>	* function on each value, or null if none
4082	>	* @since 1.8
4083	>	*/
4084	>	public <U> U searchValues(long parallelismThreshold,
4085	>	Function<? super V, ? extends U> searchFunction) {
4086	>	if (searchFunction == null) throw new NullPointerException();
4087	>	return new SearchValuesTask<K,V,U>
4088	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4089	>	searchFunction, new AtomicReference<U>()).invoke();
4090	>	}
4091	>
4092	>	/**
4093	>	* Returns the result of accumulating all values using the
4094	>	* given reducer to combine values, or null if none.
4095	>	*
4096	>	* @param parallelismThreshold the (estimated) number of elements
4097	>	* needed for this operation to be executed in parallel
4098	>	* @param reducer a commutative associative combining function
4099	>	* @return the result of accumulating all values
4100	>	* @since 1.8
4101	>	*/
4102	>	public V reduceValues(long parallelismThreshold,
4103	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4104	>	if (reducer == null) throw new NullPointerException();
4105	>	return new ReduceValuesTask<K,V>
4106	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4107	>	null, reducer).invoke();
4108	>	}
4109	>
4110	>	/**
4111	>	* Returns the result of accumulating the given transformation
4112	>	* of all values using the given reducer to combine values, or
4113	>	* null if none.
4114	>	*
4115	>	* @param parallelismThreshold the (estimated) number of elements
4116	>	* needed for this operation to be executed in parallel
4117	>	* @param transformer a function returning the transformation
4118	>	* for an element, or null if there is no transformation (in
4119	>	* which case it is not combined)
4120	>	* @param reducer a commutative associative combining function
4121	>	* @param <U> the return type of the transformer
4122	>	* @return the result of accumulating the given transformation
4123	>	* of all values
4124	>	* @since 1.8
4125	>	*/
4126	>	public <U> U reduceValues(long parallelismThreshold,
4127	>	Function<? super V, ? extends U> transformer,
4128	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4129	>	if (transformer == null || reducer == null)
4130	>	throw new NullPointerException();
4131	>	return new MapReduceValuesTask<K,V,U>
4132	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4133	>	null, transformer, reducer).invoke();
4134	>	}
4135	>
4136	>	/**
4137	>	* Returns the result of accumulating the given transformation
4138	>	* of all values using the given reducer to combine values,
4139	>	* and the given basis as an identity value.
4140	>	*
4141	>	* @param parallelismThreshold the (estimated) number of elements
4142	>	* needed for this operation to be executed in parallel
4143	>	* @param transformer a function returning the transformation
4144	>	* for an element
4145	>	* @param basis the identity (initial default value) for the reduction
4146	>	* @param reducer a commutative associative combining function
4147	>	* @return the result of accumulating the given transformation
4148	>	* of all values
4149	>	* @since 1.8
4150	>	*/
4151	>	public double reduceValuesToDouble(long parallelismThreshold,
4152	>	ToDoubleFunction<? super V> transformer,
4153	>	double basis,
4154	>	DoubleBinaryOperator reducer) {
4155	>	if (transformer == null || reducer == null)
4156	>	throw new NullPointerException();
4157	>	return new MapReduceValuesToDoubleTask<K,V>
4158	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4159	>	null, transformer, basis, reducer).invoke();
4160	>	}
4161	>
4162	>	/**
4163	>	* Returns the result of accumulating the given transformation
4164	>	* of all values using the given reducer to combine values,
4165	>	* and the given basis as an identity value.
4166	>	*
4167	>	* @param parallelismThreshold the (estimated) number of elements
4168	>	* needed for this operation to be executed in parallel
4169	>	* @param transformer a function returning the transformation
4170	>	* for an element
4171	>	* @param basis the identity (initial default value) for the reduction
4172	>	* @param reducer a commutative associative combining function
4173	>	* @return the result of accumulating the given transformation
4174	>	* of all values
4175	>	* @since 1.8
4176	>	*/
4177	>	public long reduceValuesToLong(long parallelismThreshold,
4178	>	ToLongFunction<? super V> transformer,
4179	>	long basis,
4180	>	LongBinaryOperator reducer) {
4181	>	if (transformer == null || reducer == null)
4182	>	throw new NullPointerException();
4183	>	return new MapReduceValuesToLongTask<K,V>
4184	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4185	>	null, transformer, basis, reducer).invoke();
4186	>	}
4187	>
4188	>	/**
4189	>	* Returns the result of accumulating the given transformation
4190	>	* of all values using the given reducer to combine values,
4191	>	* and the given basis as an identity value.
4192	>	*
4193	>	* @param parallelismThreshold the (estimated) number of elements
4194	>	* needed for this operation to be executed in parallel
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 values
4201	>	* @since 1.8
4202	>	*/
4203	>	public int reduceValuesToInt(long parallelismThreshold,
4204	>	ToIntFunction<? super V> transformer,
4205	>	int basis,
4206	>	IntBinaryOperator reducer) {
4207	>	if (transformer == null || reducer == null)
4208	>	throw new NullPointerException();
4209	>	return new MapReduceValuesToIntTask<K,V>
4210	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4211	>	null, transformer, basis, reducer).invoke();
4212	>	}
4213	>
4214	>	/**
4215	>	* Performs the given action for each entry.
4216	>	*
4217	>	* @param parallelismThreshold the (estimated) number of elements
4218	>	* needed for this operation to be executed in parallel
4219	>	* @param action the action
4220	>	* @since 1.8
4221	>	*/
4222	>	public void forEachEntry(long parallelismThreshold,
4223	>	Consumer<? super Map.Entry<K,V>> action) {
4224	>	if (action == null) throw new NullPointerException();
4225	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4226	>	action).invoke();
4227	>	}
4228	>
4229	>	/**
4230	>	* Performs the given action for each non-null transformation
4231	>	* of each entry.
4232	>	*
4233	>	* @param parallelismThreshold the (estimated) number of elements
4234	>	* needed for this operation to be executed in parallel
4235	>	* @param transformer a function returning the transformation
4236	>	* for an element, or null if there is no transformation (in
4237	>	* which case the action is not applied)
4238	>	* @param action the action
4239	>	* @param <U> the return type of the transformer
4240	>	* @since 1.8
4241	>	*/
4242	>	public <U> void forEachEntry(long parallelismThreshold,
4243	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4244	>	Consumer<? super U> action) {
4245	>	if (transformer == null || action == null)
4246	>	throw new NullPointerException();
4247	>	new ForEachTransformedEntryTask<K,V,U>
4248	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4249	>	transformer, action).invoke();
4250	>	}
4251	>
4252	>	/**
4253	>	* Returns a non-null result from applying the given search
4254	>	* function on each entry, or null if none.  Upon success,
4255	>	* further element processing is suppressed and the results of
4256	>	* any other parallel invocations of the search function are
4257	>	* ignored.
4258	>	*
4259	>	* @param parallelismThreshold the (estimated) number of elements
4260	>	* needed for this operation to be executed in parallel
4261	>	* @param searchFunction a function returning a non-null
4262	>	* result on success, else null
4263	>	* @param <U> the return type of the search function
4264	>	* @return a non-null result from applying the given search
4265	>	* function on each entry, or null if none
4266	>	* @since 1.8
4267	>	*/
4268	>	public <U> U searchEntries(long parallelismThreshold,
4269	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4270	>	if (searchFunction == null) throw new NullPointerException();
4271	>	return new SearchEntriesTask<K,V,U>
4272	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4273	>	searchFunction, new AtomicReference<U>()).invoke();
4274	>	}
4275	>
4276	>	/**
4277	>	* Returns the result of accumulating all entries using the
4278	>	* given reducer to combine values, or null if none.
4279	>	*
4280	>	* @param parallelismThreshold the (estimated) number of elements
4281	>	* needed for this operation to be executed in parallel
4282	>	* @param reducer a commutative associative combining function
4283	>	* @return the result of accumulating all entries
4284	>	* @since 1.8
4285	>	*/
4286	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4287	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4288	>	if (reducer == null) throw new NullPointerException();
4289	>	return new ReduceEntriesTask<K,V>
4290	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4291	>	null, reducer).invoke();
4292	>	}
4293	>
4294	>	/**
4295	>	* Returns the result of accumulating the given transformation
4296	>	* of all entries using the given reducer to combine values,
4297	>	* or null if none.
4298	>	*
4299	>	* @param parallelismThreshold the (estimated) number of elements
4300	>	* needed for this operation to be executed in parallel
4301	>	* @param transformer a function returning the transformation
4302	>	* for an element, or null if there is no transformation (in
4303	>	* which case it is not combined)
4304	>	* @param reducer a commutative associative combining function
4305	>	* @param <U> the return type of the transformer
4306	>	* @return the result of accumulating the given transformation
4307	>	* of all entries
4308	>	* @since 1.8
4309	>	*/
4310	>	public <U> U reduceEntries(long parallelismThreshold,
4311	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4312	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4313	>	if (transformer == null || reducer == null)
4314	>	throw new NullPointerException();
4315	>	return new MapReduceEntriesTask<K,V,U>
4316	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4317	>	null, transformer, reducer).invoke();
4318	>	}
4319	>
4320	>	/**
4321	>	* Returns the result of accumulating the given transformation
4322	>	* of all entries using the given reducer to combine values,
4323	>	* and the given basis as an identity value.
4324	>	*
4325	>	* @param parallelismThreshold the (estimated) number of elements
4326	>	* needed for this operation to be executed in parallel
4327	>	* @param transformer a function returning the transformation
4328	>	* for an element
4329	>	* @param basis the identity (initial default value) for the reduction
4330	>	* @param reducer a commutative associative combining function
4331	>	* @return the result of accumulating the given transformation
4332	>	* of all entries
4333	>	* @since 1.8
4334	>	*/
4335	>	public double reduceEntriesToDouble(long parallelismThreshold,
4336	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4337	>	double basis,
4338	>	DoubleBinaryOperator reducer) {
4339	>	if (transformer == null || reducer == null)
4340	>	throw new NullPointerException();
4341	>	return new MapReduceEntriesToDoubleTask<K,V>
4342	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4343	>	null, transformer, basis, reducer).invoke();
4344	>	}
4345	>
4346	>	/**
4347	>	* Returns the result of accumulating the given transformation
4348	>	* of all entries using the given reducer to combine values,
4349	>	* and the given basis as an identity value.
4350	>	*
4351	>	* @param parallelismThreshold the (estimated) number of elements
4352	>	* needed for this operation to be executed in parallel
4353	>	* @param transformer a function returning the transformation
4354	>	* for an element
4355	>	* @param basis the identity (initial default value) for the reduction
4356	>	* @param reducer a commutative associative combining function
4357	>	* @return the result of accumulating the given transformation
4358	>	* of all entries
4359	>	* @since 1.8
4360	>	*/
4361	>	public long reduceEntriesToLong(long parallelismThreshold,
4362	>	ToLongFunction<Map.Entry<K,V>> transformer,
4363	>	long basis,
4364	>	LongBinaryOperator reducer) {
4365	>	if (transformer == null || reducer == null)
4366	>	throw new NullPointerException();
4367	>	return new MapReduceEntriesToLongTask<K,V>
4368	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4369	>	null, transformer, basis, reducer).invoke();
4370	>	}
4371	>
4372	>	/**
4373	>	* Returns the result of accumulating the given transformation
4374	>	* of all entries using the given reducer to combine values,
4375	>	* and the given basis as an identity value.
4376	>	*
4377	>	* @param parallelismThreshold the (estimated) number of elements
4378	>	* needed for this operation to be executed in parallel
4379	>	* @param transformer a function returning the transformation
4380	>	* for an element
4381	>	* @param basis the identity (initial default value) for the reduction
4382	>	* @param reducer a commutative associative combining function
4383	>	* @return the result of accumulating the given transformation
4384	>	* of all entries
4385	>	* @since 1.8
4386	>	*/
4387	>	public int reduceEntriesToInt(long parallelismThreshold,
4388	>	ToIntFunction<Map.Entry<K,V>> transformer,
4389	>	int basis,
4390	>	IntBinaryOperator reducer) {
4391	>	if (transformer == null || reducer == null)
4392	>	throw new NullPointerException();
4393	>	return new MapReduceEntriesToIntTask<K,V>
4394	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4395	>	null, transformer, basis, reducer).invoke();
4396	>	}
4397	>
4398	>
4399	>	/* ----------------Views -------------- */
4400	>
4401	>	/**
4402	>	* Base class for views.
4403	>	*/
4404	>	abstract static class CollectionView<K,V,E>
4405	>	implements Collection<E>, java.io.Serializable {
4406	>	private static final long serialVersionUID = 7249069246763182397L;
4407	>	final ConcurrentHashMap<K,V> map;
4408	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4409	>
4410	>	/**
4411	>	* Returns the map backing this view.
4412	>	*
4413	>	* @return the map backing this view
4414	>	*/
4415	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4416	>
4417	>	/**
4418	>	* Removes all of the elements from this view, by removing all
4419	>	* the mappings from the map backing this view.
4420	>	*/
4421	>	public final void clear()      { map.clear(); }
4422	>	public final int size()        { return map.size(); }
4423	>	public final boolean isEmpty() { return map.isEmpty(); }
4424	>
4425	>	// implementations below rely on concrete classes supplying these
4426	>	// abstract methods
4427	>	/**
4428	>	* Returns an iterator over the elements in this collection.
4429	>	*
4430	>	* <p>The returned iterator is
4431	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4432	>	*
4433	>	* @return an iterator over the elements in this collection
4434	>	*/
4435	>	public abstract Iterator<E> iterator();
4436	>	public abstract boolean contains(Object o);
4437	>	public abstract boolean remove(Object o);
4438	>
4439	>	private static final String OOME_MSG = "Required array size too large";
4440	>
4441	>	public final Object[] toArray() {
4442	>	long sz = map.mappingCount();
4443	>	if (sz > MAX_ARRAY_SIZE)
4444	>	throw new OutOfMemoryError(OOME_MSG);
4445	>	int n = (int)sz;
4446	>	Object[] r = new Object[n];
4447	>	int i = 0;
4448	>	for (E e : this) {
4449	>	if (i == n) {
4450	>	if (n >= MAX_ARRAY_SIZE)
4451	>	throw new OutOfMemoryError(OOME_MSG);
4452	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4453	>	n = MAX_ARRAY_SIZE;
4454	>	else
4455	>	n += (n >>> 1) + 1;
4456	>	r = Arrays.copyOf(r, n);
4457	>	}
4458	>	r[i++] = e;
4459	>	}
4460	>	return (i == n) ? r : Arrays.copyOf(r, i);
4461		}
4462	<	public int size() {
4463	<	return ConcurrentHashMap.this.size();
4462	>
4463	>	@SuppressWarnings("unchecked")
4464	>	public final <T> T[] toArray(T[] a) {
4465	>	long sz = map.mappingCount();
4466	>	if (sz > MAX_ARRAY_SIZE)
4467	>	throw new OutOfMemoryError(OOME_MSG);
4468	>	int m = (int)sz;
4469	>	T[] r = (a.length >= m) ? a :
4470	>	(T[])java.lang.reflect.Array
4471	>	.newInstance(a.getClass().getComponentType(), m);
4472	>	int n = r.length;
4473	>	int i = 0;
4474	>	for (E e : this) {
4475	>	if (i == n) {
4476	>	if (n >= MAX_ARRAY_SIZE)
4477	>	throw new OutOfMemoryError(OOME_MSG);
4478	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4479	>	n = MAX_ARRAY_SIZE;
4480	>	else
4481	>	n += (n >>> 1) + 1;
4482	>	r = Arrays.copyOf(r, n);
4483	>	}
4484	>	r[i++] = (T)e;
4485	>	}
4486	>	if (a == r && i < n) {
4487	>	r[i] = null; // null-terminate
4488	>	return r;
4489	>	}
4490	>	return (i == n) ? r : Arrays.copyOf(r, i);
4491		}
4492	<	public boolean isEmpty() {
4493	<	return ConcurrentHashMap.this.isEmpty();
4492	>
4493	>	/**
4494	>	* Returns a string representation of this collection.
4495	>	* The string representation consists of the string representations
4496	>	* of the collection's elements in the order they are returned by
4497	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4498	>	* Adjacent elements are separated by the characters {@code ", "}
4499	>	* (comma and space).  Elements are converted to strings as by
4500	>	* {@link String#valueOf(Object)}.
4501	>	*
4502	>	* @return a string representation of this collection
4503	>	*/
4504	>	public final String toString() {
4505	>	StringBuilder sb = new StringBuilder();
4506	>	sb.append('[');
4507	>	Iterator<E> it = iterator();
4508	>	if (it.hasNext()) {
4509	>	for (;;) {
4510	>	Object e = it.next();
4511	>	sb.append(e == this ? "(this Collection)" : e);
4512	>	if (!it.hasNext())
4513	>	break;
4514	>	sb.append(',').append(' ');
4515	>	}
4516	>	}
4517	>	return sb.append(']').toString();
4518		}
4519	<	public boolean contains(Object o) {
4520	<	return ConcurrentHashMap.this.containsValue(o);
4519	>
4520	>	public final boolean containsAll(Collection<?> c) {
4521	>	if (c != this) {
4522	>	for (Object e : c) {
4523	>	if (e == null || !contains(e))
4524	>	return false;
4525	>	}
4526	>	}
4527	>	return true;
4528		}
4529	<	public void clear() {
4530	<	ConcurrentHashMap.this.clear();
4529	>
4530	>	public boolean removeAll(Collection<?> c) {
4531	>	if (c == null) throw new NullPointerException();
4532	>	boolean modified = false;
4533	>	// Use (c instanceof Set) as a hint that lookup in c is as
4534	>	// efficient as this view
4535	>	Node<K,V>[] t;
4536	>	if ((t = map.table) == null) {
4537	>	return false;
4538	>	} else if (c instanceof Set<?> && c.size() > t.length) {
4539	>	for (Iterator<?> it = iterator(); it.hasNext(); ) {
4540	>	if (c.contains(it.next())) {
4541	>	it.remove();
4542	>	modified = true;
4543	>	}
4544	>	}
4545	>	} else {
4546	>	for (Object e : c)
4547	>	modified |= remove(e);
4548	>	}
4549	>	return modified;
4550	>	}
4551	>
4552	>	public final boolean retainAll(Collection<?> c) {
4553	>	if (c == null) throw new NullPointerException();
4554	>	boolean modified = false;
4555	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4556	>	if (!c.contains(it.next())) {
4557	>	it.remove();
4558	>	modified = true;
4559	>	}
4560	>	}
4561	>	return modified;
4562		}
4563	+
4564		}
4565
4566	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4567	<	public Iterator<Map.Entry<K,V>> iterator() {
4568	<	return new EntryIterator();
4566	>	/**
4567	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4568	>	* which additions may optionally be enabled by mapping to a
4569	>	* common value.  This class cannot be directly instantiated.
4570	>	* See {@link #keySet() keySet()},
4571	>	* {@link #keySet(Object) keySet(V)},
4572	>	* {@link #newKeySet() newKeySet()},
4573	>	* {@link #newKeySet(int) newKeySet(int)}.
4574	>	*
4575	>	* @since 1.8
4576	>	*/
4577	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4578	>	implements Set<K>, java.io.Serializable {
4579	>	private static final long serialVersionUID = 7249069246763182397L;
4580	>	private final V value;
4581	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4582	>	super(map);
4583	>	this.value = value;
4584		}
4585	+
4586	+	/**
4587	+	* Returns the default mapped value for additions,
4588	+	* or {@code null} if additions are not supported.
4589	+	*
4590	+	* @return the default mapped value for additions, or {@code null}
4591	+	* if not supported
4592	+	*/
4593	+	public V getMappedValue() { return value; }
4594	+
4595	+	/**
4596	+	* {@inheritDoc}
4597	+	* @throws NullPointerException if the specified key is null
4598	+	*/
4599	+	public boolean contains(Object o) { return map.containsKey(o); }
4600	+
4601	+	/**
4602	+	* Removes the key from this map view, by removing the key (and its
4603	+	* corresponding value) from the backing map.  This method does
4604	+	* nothing if the key is not in the map.
4605	+	*
4606	+	* @param  o the key to be removed from the backing map
4607	+	* @return {@code true} if the backing map contained the specified key
4608	+	* @throws NullPointerException if the specified key is null
4609	+	*/
4610	+	public boolean remove(Object o) { return map.remove(o) != null; }
4611	+
4612	+	/**
4613	+	* @return an iterator over the keys of the backing map
4614	+	*/
4615	+	public Iterator<K> iterator() {
4616	+	Node<K,V>[] t;
4617	+	ConcurrentHashMap<K,V> m = map;
4618	+	int f = (t = m.table) == null ? 0 : t.length;
4619	+	return new KeyIterator<K,V>(t, f, 0, f, m);
4620	+	}
4621	+
4622	+	/**
4623	+	* Adds the specified key to this set view by mapping the key to
4624	+	* the default mapped value in the backing map, if defined.
4625	+	*
4626	+	* @param e key to be added
4627	+	* @return {@code true} if this set changed as a result of the call
4628	+	* @throws NullPointerException if the specified key is null
4629	+	* @throws UnsupportedOperationException if no default mapped value
4630	+	* for additions was provided
4631	+	*/
4632	+	public boolean add(K e) {
4633	+	V v;
4634	+	if ((v = value) == null)
4635	+	throw new UnsupportedOperationException();
4636	+	return map.putVal(e, v, true) == null;
4637	+	}
4638	+
4639	+	/**
4640	+	* Adds all of the elements in the specified collection to this set,
4641	+	* as if by calling {@link #add} on each one.
4642	+	*
4643	+	* @param c the elements to be inserted into this set
4644	+	* @return {@code true} if this set changed as a result of the call
4645	+	* @throws NullPointerException if the collection or any of its
4646	+	* elements are {@code null}
4647	+	* @throws UnsupportedOperationException if no default mapped value
4648	+	* for additions was provided
4649	+	*/
4650	+	public boolean addAll(Collection<? extends K> c) {
4651	+	boolean added = false;
4652	+	V v;
4653	+	if ((v = value) == null)
4654	+	throw new UnsupportedOperationException();
4655	+	for (K e : c) {
4656	+	if (map.putVal(e, v, true) == null)
4657	+	added = true;
4658	+	}
4659	+	return added;
4660	+	}
4661	+
4662	+	public int hashCode() {
4663	+	int h = 0;
4664	+	for (K e : this)
4665	+	h += e.hashCode();
4666	+	return h;
4667	+	}
4668	+
4669	+	public boolean equals(Object o) {
4670	+	Set<?> c;
4671	+	return ((o instanceof Set) &&
4672	+	((c = (Set<?>)o) == this ||
4673	+	(containsAll(c) && c.containsAll(this))));
4674	+	}
4675	+
4676	+	public Spliterator<K> spliterator() {
4677	+	Node<K,V>[] t;
4678	+	ConcurrentHashMap<K,V> m = map;
4679	+	long n = m.sumCount();
4680	+	int f = (t = m.table) == null ? 0 : t.length;
4681	+	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4682	+	}
4683	+
4684	+	public void forEach(Consumer<? super K> action) {
4685	+	if (action == null) throw new NullPointerException();
4686	+	Node<K,V>[] t;
4687	+	if ((t = map.table) != null) {
4688	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4689	+	for (Node<K,V> p; (p = it.advance()) != null; )
4690	+	action.accept(p.key);
4691	+	}
4692	+	}
4693	+	}
4694	+
4695	+	/**
4696	+	* A view of a ConcurrentHashMap as a {@link Collection} of
4697	+	* values, in which additions are disabled. This class cannot be
4698	+	* directly instantiated. See {@link #values()}.
4699	+	*/
4700	+	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4701	+	implements Collection<V>, java.io.Serializable {
4702	+	private static final long serialVersionUID = 2249069246763182397L;
4703	+	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4704	+	public final boolean contains(Object o) {
4705	+	return map.containsValue(o);
4706	+	}
4707	+
4708	+	public final boolean remove(Object o) {
4709	+	if (o != null) {
4710	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4711	+	if (o.equals(it.next())) {
4712	+	it.remove();
4713	+	return true;
4714	+	}
4715	+	}
4716	+	}
4717	+	return false;
4718	+	}
4719	+
4720	+	public final Iterator<V> iterator() {
4721	+	ConcurrentHashMap<K,V> m = map;
4722	+	Node<K,V>[] t;
4723	+	int f = (t = m.table) == null ? 0 : t.length;
4724	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4725	+	}
4726	+
4727	+	public final boolean add(V e) {
4728	+	throw new UnsupportedOperationException();
4729	+	}
4730	+	public final boolean addAll(Collection<? extends V> c) {
4731	+	throw new UnsupportedOperationException();
4732	+	}
4733	+
4734	+	@Override public boolean removeAll(Collection<?> c) {
4735	+	if (c == null) throw new NullPointerException();
4736	+	boolean modified = false;
4737	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4738	+	if (c.contains(it.next())) {
4739	+	it.remove();
4740	+	modified = true;
4741	+	}
4742	+	}
4743	+	return modified;
4744	+	}
4745	+
4746	+	public boolean removeIf(Predicate<? super V> filter) {
4747	+	return map.removeValueIf(filter);
4748	+	}
4749	+
4750	+	public Spliterator<V> spliterator() {
4751	+	Node<K,V>[] t;
4752	+	ConcurrentHashMap<K,V> m = map;
4753	+	long n = m.sumCount();
4754	+	int f = (t = m.table) == null ? 0 : t.length;
4755	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4756	+	}
4757	+
4758	+	public void forEach(Consumer<? super V> action) {
4759	+	if (action == null) throw new NullPointerException();
4760	+	Node<K,V>[] t;
4761	+	if ((t = map.table) != null) {
4762	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4763	+	for (Node<K,V> p; (p = it.advance()) != null; )
4764	+	action.accept(p.val);
4765	+	}
4766	+	}
4767	+	}
4768	+
4769	+	/**
4770	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4771	+	* entries.  This class cannot be directly instantiated. See
4772	+	* {@link #entrySet()}.
4773	+	*/
4774	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4775	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4776	+	private static final long serialVersionUID = 2249069246763182397L;
4777	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4778	+
4779		public boolean contains(Object o) {
4780	<	if (!(o instanceof Map.Entry))
4781	<	return false;
4782	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4783	<	V v = ConcurrentHashMap.this.get(e.getKey());
4784	<	return v != null && v.equals(e.getValue());
4780	>	Object k, v, r; Map.Entry<?,?> e;
4781	>	return ((o instanceof Map.Entry) &&
4782	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4783	>	(r = map.get(k)) != null &&
4784	>	(v = e.getValue()) != null &&
4785	>	(v == r || v.equals(r)));
4786		}
4787	+
4788		public boolean remove(Object o) {
4789	<	if (!(o instanceof Map.Entry))
4790	<	return false;
4791	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4792	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4789	>	Object k, v; Map.Entry<?,?> e;
4790	>	return ((o instanceof Map.Entry) &&
4791	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4792	>	(v = e.getValue()) != null &&
4793	>	map.remove(k, v));
4794		}
4795	<	public int size() {
4796	<	return ConcurrentHashMap.this.size();
4795	>
4796	>	/**
4797	>	* @return an iterator over the entries of the backing map
4798	>	*/
4799	>	public Iterator<Map.Entry<K,V>> iterator() {
4800	>	ConcurrentHashMap<K,V> m = map;
4801	>	Node<K,V>[] t;
4802	>	int f = (t = m.table) == null ? 0 : t.length;
4803	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4804		}
4805	<	public boolean isEmpty() {
4806	<	return ConcurrentHashMap.this.isEmpty();
4805	>
4806	>	public boolean add(Entry<K,V> e) {
4807	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4808		}
4809	<	public void clear() {
4810	<	ConcurrentHashMap.this.clear();
4809	>
4810	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4811	>	boolean added = false;
4812	>	for (Entry<K,V> e : c) {
4813	>	if (add(e))
4814	>	added = true;
4815	>	}
4816	>	return added;
4817	>	}
4818	>
4819	>	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4820	>	return map.removeEntryIf(filter);
4821	>	}
4822	>
4823	>	public final int hashCode() {
4824	>	int h = 0;
4825	>	Node<K,V>[] t;
4826	>	if ((t = map.table) != null) {
4827	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4828	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4829	>	h += p.hashCode();
4830	>	}
4831	>	}
4832	>	return h;
4833	>	}
4834	>
4835	>	public final boolean equals(Object o) {
4836	>	Set<?> c;
4837	>	return ((o instanceof Set) &&
4838	>	((c = (Set<?>)o) == this ||
4839	>	(containsAll(c) && c.containsAll(this))));
4840	>	}
4841	>
4842	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4843	>	Node<K,V>[] t;
4844	>	ConcurrentHashMap<K,V> m = map;
4845	>	long n = m.sumCount();
4846	>	int f = (t = m.table) == null ? 0 : t.length;
4847	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4848	>	}
4849	>
4850	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4851	>	if (action == null) throw new NullPointerException();
4852	>	Node<K,V>[] t;
4853	>	if ((t = map.table) != null) {
4854	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4855	>	for (Node<K,V> p; (p = it.advance()) != null; )
4856	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4857	>	}
4858		}
4859	+
4860		}
4861
4862	<	/* ---------------- Serialization Support -------------- */
4862	>	// -------------------------------------------------------
4863
4864		/**
4865	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4866	<	* stream (i.e., serializes it).
1394	<	* @param s the stream
1395	<	* @serialData
1396	<	* the key (Object) and value (Object)
1397	<	* for each key-value mapping, followed by a null pair.
1398	<	* The key-value mappings are emitted in no particular order.
4865	>	* Base class for bulk tasks. Repeats some fields and code from
4866	>	* class Traverser, because we need to subclass CountedCompleter.
4867		*/
4868	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4869	<	// force all segments for serialization compatibility
4870	<	for (int k = 0; k < segments.length; ++k)
4871	<	ensureSegment(k);
4872	<	s.defaultWriteObject();
4873	<
4874	<	final Segment<K,V>[] segments = this.segments;
4875	<	for (int k = 0; k < segments.length; ++k) {
4876	<	Segment<K,V> seg = segmentAt(segments, k);
4877	<	seg.lock();
4878	<	try {
4879	<	HashEntry<K,V>[] tab = seg.table;
4880	<	for (int i = 0; i < tab.length; ++i) {
4881	<	HashEntry<K,V> e;
4882	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4883	<	s.writeObject(e.key);
4884	<	s.writeObject(e.value);
4868	>	@SuppressWarnings("serial")
4869	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4870	>	Node<K,V>[] tab;        // same as Traverser
4871	>	Node<K,V> next;
4872	>	TableStack<K,V> stack, spare;
4873	>	int index;
4874	>	int baseIndex;
4875	>	int baseLimit;
4876	>	final int baseSize;
4877	>	int batch;              // split control
4878	>
4879	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4880	>	super(par);
4881	>	this.batch = b;
4882	>	this.index = this.baseIndex = i;
4883	>	if ((this.tab = t) == null)
4884	>	this.baseSize = this.baseLimit = 0;
4885	>	else if (par == null)
4886	>	this.baseSize = this.baseLimit = t.length;
4887	>	else {
4888	>	this.baseLimit = f;
4889	>	this.baseSize = par.baseSize;
4890	>	}
4891	>	}
4892	>
4893	>	/**
4894	>	* Same as Traverser version.
4895	>	*/
4896	>	final Node<K,V> advance() {
4897	>	Node<K,V> e;
4898	>	if ((e = next) != null)
4899	>	e = e.next;
4900	>	for (;;) {
4901	>	Node<K,V>[] t; int i, n;
4902	>	if (e != null)
4903	>	return next = e;
4904	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4905	>	(n = t.length) <= (i = index) || i < 0)
4906	>	return next = null;
4907	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4908	>	if (e instanceof ForwardingNode) {
4909	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4910	>	e = null;
4911	>	pushState(t, i, n);
4912	>	continue;
4913		}
4914	+	else if (e instanceof TreeBin)
4915	+	e = ((TreeBin<K,V>)e).first;
4916	+	else
4917	+	e = null;
4918		}
4919	<	} finally {
4920	<	seg.unlock();
4919	>	if (stack != null)
4920	>	recoverState(n);
4921	>	else if ((index = i + baseSize) >= n)
4922	>	index = ++baseIndex;
4923		}
4924		}
4925	<	s.writeObject(null);
4926	<	s.writeObject(null);
4925	>
4926	>	private void pushState(Node<K,V>[] t, int i, int n) {
4927	>	TableStack<K,V> s = spare;
4928	>	if (s != null)
4929	>	spare = s.next;
4930	>	else
4931	>	s = new TableStack<K,V>();
4932	>	s.tab = t;
4933	>	s.length = n;
4934	>	s.index = i;
4935	>	s.next = stack;
4936	>	stack = s;
4937	>	}
4938	>
4939	>	private void recoverState(int n) {
4940	>	TableStack<K,V> s; int len;
4941	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4942	>	n = len;
4943	>	index = s.index;
4944	>	tab = s.tab;
4945	>	s.tab = null;
4946	>	TableStack<K,V> next = s.next;
4947	>	s.next = spare; // save for reuse
4948	>	stack = next;
4949	>	spare = s;
4950	>	}
4951	>	if (s == null && (index += baseSize) >= n)
4952	>	index = ++baseIndex;
4953	>	}
4954		}
4955
4956	<	/**
4957	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4958	<	* stream (i.e., deserializes it).
4959	<	* @param s the stream
4960	<	*/
4961	<	@SuppressWarnings("unchecked")
4962	<	private void readObject(java.io.ObjectInputStream s)
4963	<	throws IOException, ClassNotFoundException {
4964	<	s.defaultReadObject();
4956	>	/*
4957	>	* Task classes. Coded in a regular but ugly format/style to
4958	>	* simplify checks that each variant differs in the right way from
4959	>	* others. The null screenings exist because compilers cannot tell
4960	>	* that we've already null-checked task arguments, so we force
4961	>	* simplest hoisted bypass to help avoid convoluted traps.
4962	>	*/
4963	>	@SuppressWarnings("serial")
4964	>	static final class ForEachKeyTask<K,V>
4965	>	extends BulkTask<K,V,Void> {
4966	>	final Consumer<? super K> action;
4967	>	ForEachKeyTask
4968	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4969	>	Consumer<? super K> action) {
4970	>	super(p, b, i, f, t);
4971	>	this.action = action;
4972	>	}
4973	>	public final void compute() {
4974	>	final Consumer<? super K> action;
4975	>	if ((action = this.action) != null) {
4976	>	for (int i = baseIndex, f, h; batch > 0 &&
4977	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4978	>	addToPendingCount(1);
4979	>	new ForEachKeyTask<K,V>
4980	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4981	>	action).fork();
4982	>	}
4983	>	for (Node<K,V> p; (p = advance()) != null;)
4984	>	action.accept(p.key);
4985	>	propagateCompletion();
4986	>	}
4987	>	}
4988	>	}
4989
4990	<	// Re-initialize segments to be minimally sized, and let grow.
4991	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4992	<	final Segment<K,V>[] segments = this.segments;
4993	<	for (int k = 0; k < segments.length; ++k) {
4994	<	Segment<K,V> seg = segments[k];
4995	<	if (seg != null) {
4996	<	seg.threshold = (int)(cap * seg.loadFactor);
4997	<	seg.table = (HashEntry<K,V>[]) new HashEntry<?,?>[cap];
4990	>	@SuppressWarnings("serial")
4991	>	static final class ForEachValueTask<K,V>
4992	>	extends BulkTask<K,V,Void> {
4993	>	final Consumer<? super V> action;
4994	>	ForEachValueTask
4995	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4996	>	Consumer<? super V> action) {
4997	>	super(p, b, i, f, t);
4998	>	this.action = action;
4999	>	}
5000	>	public final void compute() {
5001	>	final Consumer<? super V> action;
5002	>	if ((action = this.action) != null) {
5003	>	for (int i = baseIndex, f, h; batch > 0 &&
5004	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5005	>	addToPendingCount(1);
5006	>	new ForEachValueTask<K,V>
5007	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5008	>	action).fork();
5009	>	}
5010	>	for (Node<K,V> p; (p = advance()) != null;)
5011	>	action.accept(p.val);
5012	>	propagateCompletion();
5013		}
5014		}
5015	+	}
5016
5017	<	// Read the keys and values, and put the mappings in the table
5018	<	for (;;) {
5019	<	K key = (K) s.readObject();
5020	<	V value = (V) s.readObject();
5021	<	if (key == null)
5022	<	break;
5023	<	put(key, value);
5017	>	@SuppressWarnings("serial")
5018	>	static final class ForEachEntryTask<K,V>
5019	>	extends BulkTask<K,V,Void> {
5020	>	final Consumer<? super Entry<K,V>> action;
5021	>	ForEachEntryTask
5022	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5023	>	Consumer<? super Entry<K,V>> action) {
5024	>	super(p, b, i, f, t);
5025	>	this.action = action;
5026	>	}
5027	>	public final void compute() {
5028	>	final Consumer<? super Entry<K,V>> action;
5029	>	if ((action = this.action) != null) {
5030	>	for (int i = baseIndex, f, h; batch > 0 &&
5031	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5032	>	addToPendingCount(1);
5033	>	new ForEachEntryTask<K,V>
5034	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5035	>	action).fork();
5036	>	}
5037	>	for (Node<K,V> p; (p = advance()) != null; )
5038	>	action.accept(p);
5039	>	propagateCompletion();
5040	>	}
5041	>	}
5042	>	}
5043	>
5044	>	@SuppressWarnings("serial")
5045	>	static final class ForEachMappingTask<K,V>
5046	>	extends BulkTask<K,V,Void> {
5047	>	final BiConsumer<? super K, ? super V> action;
5048	>	ForEachMappingTask
5049	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5050	>	BiConsumer<? super K,? super V> action) {
5051	>	super(p, b, i, f, t);
5052	>	this.action = action;
5053	>	}
5054	>	public final void compute() {
5055	>	final BiConsumer<? super K, ? super V> action;
5056	>	if ((action = this.action) != null) {
5057	>	for (int i = baseIndex, f, h; batch > 0 &&
5058	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5059	>	addToPendingCount(1);
5060	>	new ForEachMappingTask<K,V>
5061	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5062	>	action).fork();
5063	>	}
5064	>	for (Node<K,V> p; (p = advance()) != null; )
5065	>	action.accept(p.key, p.val);
5066	>	propagateCompletion();
5067	>	}
5068	>	}
5069	>	}
5070	>
5071	>	@SuppressWarnings("serial")
5072	>	static final class ForEachTransformedKeyTask<K,V,U>
5073	>	extends BulkTask<K,V,Void> {
5074	>	final Function<? super K, ? extends U> transformer;
5075	>	final Consumer<? super U> action;
5076	>	ForEachTransformedKeyTask
5077	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5078	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5079	>	super(p, b, i, f, t);
5080	>	this.transformer = transformer; this.action = action;
5081	>	}
5082	>	public final void compute() {
5083	>	final Function<? super K, ? extends U> transformer;
5084	>	final Consumer<? super U> action;
5085	>	if ((transformer = this.transformer) != null &&
5086	>	(action = this.action) != null) {
5087	>	for (int i = baseIndex, f, h; batch > 0 &&
5088	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5089	>	addToPendingCount(1);
5090	>	new ForEachTransformedKeyTask<K,V,U>
5091	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5092	>	transformer, action).fork();
5093	>	}
5094	>	for (Node<K,V> p; (p = advance()) != null; ) {
5095	>	U u;
5096	>	if ((u = transformer.apply(p.key)) != null)
5097	>	action.accept(u);
5098	>	}
5099	>	propagateCompletion();
5100	>	}
5101	>	}
5102	>	}
5103	>
5104	>	@SuppressWarnings("serial")
5105	>	static final class ForEachTransformedValueTask<K,V,U>
5106	>	extends BulkTask<K,V,Void> {
5107	>	final Function<? super V, ? extends U> transformer;
5108	>	final Consumer<? super U> action;
5109	>	ForEachTransformedValueTask
5110	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5111	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5112	>	super(p, b, i, f, t);
5113	>	this.transformer = transformer; this.action = action;
5114	>	}
5115	>	public final void compute() {
5116	>	final Function<? super V, ? extends U> transformer;
5117	>	final Consumer<? super U> action;
5118	>	if ((transformer = this.transformer) != null &&
5119	>	(action = this.action) != null) {
5120	>	for (int i = baseIndex, f, h; batch > 0 &&
5121	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5122	>	addToPendingCount(1);
5123	>	new ForEachTransformedValueTask<K,V,U>
5124	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5125	>	transformer, action).fork();
5126	>	}
5127	>	for (Node<K,V> p; (p = advance()) != null; ) {
5128	>	U u;
5129	>	if ((u = transformer.apply(p.val)) != null)
5130	>	action.accept(u);
5131	>	}
5132	>	propagateCompletion();
5133	>	}
5134	>	}
5135	>	}
5136	>
5137	>	@SuppressWarnings("serial")
5138	>	static final class ForEachTransformedEntryTask<K,V,U>
5139	>	extends BulkTask<K,V,Void> {
5140	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5141	>	final Consumer<? super U> action;
5142	>	ForEachTransformedEntryTask
5143	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5144	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5145	>	super(p, b, i, f, t);
5146	>	this.transformer = transformer; this.action = action;
5147	>	}
5148	>	public final void compute() {
5149	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5150	>	final Consumer<? super U> action;
5151	>	if ((transformer = this.transformer) != null &&
5152	>	(action = this.action) != null) {
5153	>	for (int i = baseIndex, f, h; batch > 0 &&
5154	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5155	>	addToPendingCount(1);
5156	>	new ForEachTransformedEntryTask<K,V,U>
5157	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5158	>	transformer, action).fork();
5159	>	}
5160	>	for (Node<K,V> p; (p = advance()) != null; ) {
5161	>	U u;
5162	>	if ((u = transformer.apply(p)) != null)
5163	>	action.accept(u);
5164	>	}
5165	>	propagateCompletion();
5166	>	}
5167	>	}
5168	>	}
5169	>
5170	>	@SuppressWarnings("serial")
5171	>	static final class ForEachTransformedMappingTask<K,V,U>
5172	>	extends BulkTask<K,V,Void> {
5173	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5174	>	final Consumer<? super U> action;
5175	>	ForEachTransformedMappingTask
5176	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5177	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5178	>	Consumer<? super U> action) {
5179	>	super(p, b, i, f, t);
5180	>	this.transformer = transformer; this.action = action;
5181	>	}
5182	>	public final void compute() {
5183	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5184	>	final Consumer<? super U> action;
5185	>	if ((transformer = this.transformer) != null &&
5186	>	(action = this.action) != null) {
5187	>	for (int i = baseIndex, f, h; batch > 0 &&
5188	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5189	>	addToPendingCount(1);
5190	>	new ForEachTransformedMappingTask<K,V,U>
5191	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5192	>	transformer, action).fork();
5193	>	}
5194	>	for (Node<K,V> p; (p = advance()) != null; ) {
5195	>	U u;
5196	>	if ((u = transformer.apply(p.key, p.val)) != null)
5197	>	action.accept(u);
5198	>	}
5199	>	propagateCompletion();
5200	>	}
5201	>	}
5202	>	}
5203	>
5204	>	@SuppressWarnings("serial")
5205	>	static final class SearchKeysTask<K,V,U>
5206	>	extends BulkTask<K,V,U> {
5207	>	final Function<? super K, ? extends U> searchFunction;
5208	>	final AtomicReference<U> result;
5209	>	SearchKeysTask
5210	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5211	>	Function<? super K, ? extends U> searchFunction,
5212	>	AtomicReference<U> result) {
5213	>	super(p, b, i, f, t);
5214	>	this.searchFunction = searchFunction; this.result = result;
5215	>	}
5216	>	public final U getRawResult() { return result.get(); }
5217	>	public final void compute() {
5218	>	final Function<? super K, ? extends U> searchFunction;
5219	>	final AtomicReference<U> result;
5220	>	if ((searchFunction = this.searchFunction) != null &&
5221	>	(result = this.result) != null) {
5222	>	for (int i = baseIndex, f, h; batch > 0 &&
5223	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5224	>	if (result.get() != null)
5225	>	return;
5226	>	addToPendingCount(1);
5227	>	new SearchKeysTask<K,V,U>
5228	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5229	>	searchFunction, result).fork();
5230	>	}
5231	>	while (result.get() == null) {
5232	>	U u;
5233	>	Node<K,V> p;
5234	>	if ((p = advance()) == null) {
5235	>	propagateCompletion();
5236	>	break;
5237	>	}
5238	>	if ((u = searchFunction.apply(p.key)) != null) {
5239	>	if (result.compareAndSet(null, u))
5240	>	quietlyCompleteRoot();
5241	>	break;
5242	>	}
5243	>	}
5244	>	}
5245	>	}
5246	>	}
5247	>
5248	>	@SuppressWarnings("serial")
5249	>	static final class SearchValuesTask<K,V,U>
5250	>	extends BulkTask<K,V,U> {
5251	>	final Function<? super V, ? extends U> searchFunction;
5252	>	final AtomicReference<U> result;
5253	>	SearchValuesTask
5254	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5255	>	Function<? super V, ? extends U> searchFunction,
5256	>	AtomicReference<U> result) {
5257	>	super(p, b, i, f, t);
5258	>	this.searchFunction = searchFunction; this.result = result;
5259	>	}
5260	>	public final U getRawResult() { return result.get(); }
5261	>	public final void compute() {
5262	>	final Function<? super V, ? extends U> searchFunction;
5263	>	final AtomicReference<U> result;
5264	>	if ((searchFunction = this.searchFunction) != null &&
5265	>	(result = this.result) != null) {
5266	>	for (int i = baseIndex, f, h; batch > 0 &&
5267	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5268	>	if (result.get() != null)
5269	>	return;
5270	>	addToPendingCount(1);
5271	>	new SearchValuesTask<K,V,U>
5272	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5273	>	searchFunction, result).fork();
5274	>	}
5275	>	while (result.get() == null) {
5276	>	U u;
5277	>	Node<K,V> p;
5278	>	if ((p = advance()) == null) {
5279	>	propagateCompletion();
5280	>	break;
5281	>	}
5282	>	if ((u = searchFunction.apply(p.val)) != null) {
5283	>	if (result.compareAndSet(null, u))
5284	>	quietlyCompleteRoot();
5285	>	break;
5286	>	}
5287	>	}
5288	>	}
5289	>	}
5290	>	}
5291	>
5292	>	@SuppressWarnings("serial")
5293	>	static final class SearchEntriesTask<K,V,U>
5294	>	extends BulkTask<K,V,U> {
5295	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5296	>	final AtomicReference<U> result;
5297	>	SearchEntriesTask
5298	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5299	>	Function<Entry<K,V>, ? extends U> searchFunction,
5300	>	AtomicReference<U> result) {
5301	>	super(p, b, i, f, t);
5302	>	this.searchFunction = searchFunction; this.result = result;
5303	>	}
5304	>	public final U getRawResult() { return result.get(); }
5305	>	public final void compute() {
5306	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5307	>	final AtomicReference<U> result;
5308	>	if ((searchFunction = this.searchFunction) != null &&
5309	>	(result = this.result) != null) {
5310	>	for (int i = baseIndex, f, h; batch > 0 &&
5311	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5312	>	if (result.get() != null)
5313	>	return;
5314	>	addToPendingCount(1);
5315	>	new SearchEntriesTask<K,V,U>
5316	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5317	>	searchFunction, result).fork();
5318	>	}
5319	>	while (result.get() == null) {
5320	>	U u;
5321	>	Node<K,V> p;
5322	>	if ((p = advance()) == null) {
5323	>	propagateCompletion();
5324	>	break;
5325	>	}
5326	>	if ((u = searchFunction.apply(p)) != null) {
5327	>	if (result.compareAndSet(null, u))
5328	>	quietlyCompleteRoot();
5329	>	return;
5330	>	}
5331	>	}
5332	>	}
5333	>	}
5334	>	}
5335	>
5336	>	@SuppressWarnings("serial")
5337	>	static final class SearchMappingsTask<K,V,U>
5338	>	extends BulkTask<K,V,U> {
5339	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5340	>	final AtomicReference<U> result;
5341	>	SearchMappingsTask
5342	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5343	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5344	>	AtomicReference<U> result) {
5345	>	super(p, b, i, f, t);
5346	>	this.searchFunction = searchFunction; this.result = result;
5347	>	}
5348	>	public final U getRawResult() { return result.get(); }
5349	>	public final void compute() {
5350	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5351	>	final AtomicReference<U> result;
5352	>	if ((searchFunction = this.searchFunction) != null &&
5353	>	(result = this.result) != null) {
5354	>	for (int i = baseIndex, f, h; batch > 0 &&
5355	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5356	>	if (result.get() != null)
5357	>	return;
5358	>	addToPendingCount(1);
5359	>	new SearchMappingsTask<K,V,U>
5360	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5361	>	searchFunction, result).fork();
5362	>	}
5363	>	while (result.get() == null) {
5364	>	U u;
5365	>	Node<K,V> p;
5366	>	if ((p = advance()) == null) {
5367	>	propagateCompletion();
5368	>	break;
5369	>	}
5370	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5371	>	if (result.compareAndSet(null, u))
5372	>	quietlyCompleteRoot();
5373	>	break;
5374	>	}
5375	>	}
5376	>	}
5377	>	}
5378	>	}
5379	>
5380	>	@SuppressWarnings("serial")
5381	>	static final class ReduceKeysTask<K,V>
5382	>	extends BulkTask<K,V,K> {
5383	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5384	>	K result;
5385	>	ReduceKeysTask<K,V> rights, nextRight;
5386	>	ReduceKeysTask
5387	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5388	>	ReduceKeysTask<K,V> nextRight,
5389	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5390	>	super(p, b, i, f, t); this.nextRight = nextRight;
5391	>	this.reducer = reducer;
5392	>	}
5393	>	public final K getRawResult() { return result; }
5394	>	public final void compute() {
5395	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5396	>	if ((reducer = this.reducer) != null) {
5397	>	for (int i = baseIndex, f, h; batch > 0 &&
5398	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5399	>	addToPendingCount(1);
5400	>	(rights = new ReduceKeysTask<K,V>
5401	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5402	>	rights, reducer)).fork();
5403	>	}
5404	>	K r = null;
5405	>	for (Node<K,V> p; (p = advance()) != null; ) {
5406	>	K u = p.key;
5407	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5408	>	}
5409	>	result = r;
5410	>	CountedCompleter<?> c;
5411	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5412	>	@SuppressWarnings("unchecked")
5413	>	ReduceKeysTask<K,V>
5414	>	t = (ReduceKeysTask<K,V>)c,
5415	>	s = t.rights;
5416	>	while (s != null) {
5417	>	K tr, sr;
5418	>	if ((sr = s.result) != null)
5419	>	t.result = (((tr = t.result) == null) ? sr :
5420	>	reducer.apply(tr, sr));
5421	>	s = t.rights = s.nextRight;
5422	>	}
5423	>	}
5424	>	}
5425	>	}
5426	>	}
5427	>
5428	>	@SuppressWarnings("serial")
5429	>	static final class ReduceValuesTask<K,V>
5430	>	extends BulkTask<K,V,V> {
5431	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5432	>	V result;
5433	>	ReduceValuesTask<K,V> rights, nextRight;
5434	>	ReduceValuesTask
5435	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5436	>	ReduceValuesTask<K,V> nextRight,
5437	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5438	>	super(p, b, i, f, t); this.nextRight = nextRight;
5439	>	this.reducer = reducer;
5440	>	}
5441	>	public final V getRawResult() { return result; }
5442	>	public final void compute() {
5443	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5444	>	if ((reducer = this.reducer) != null) {
5445	>	for (int i = baseIndex, f, h; batch > 0 &&
5446	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5447	>	addToPendingCount(1);
5448	>	(rights = new ReduceValuesTask<K,V>
5449	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5450	>	rights, reducer)).fork();
5451	>	}
5452	>	V r = null;
5453	>	for (Node<K,V> p; (p = advance()) != null; ) {
5454	>	V v = p.val;
5455	>	r = (r == null) ? v : reducer.apply(r, v);
5456	>	}
5457	>	result = r;
5458	>	CountedCompleter<?> c;
5459	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5460	>	@SuppressWarnings("unchecked")
5461	>	ReduceValuesTask<K,V>
5462	>	t = (ReduceValuesTask<K,V>)c,
5463	>	s = t.rights;
5464	>	while (s != null) {
5465	>	V tr, sr;
5466	>	if ((sr = s.result) != null)
5467	>	t.result = (((tr = t.result) == null) ? sr :
5468	>	reducer.apply(tr, sr));
5469	>	s = t.rights = s.nextRight;
5470	>	}
5471	>	}
5472	>	}
5473	>	}
5474	>	}
5475	>
5476	>	@SuppressWarnings("serial")
5477	>	static final class ReduceEntriesTask<K,V>
5478	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5479	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5480	>	Map.Entry<K,V> result;
5481	>	ReduceEntriesTask<K,V> rights, nextRight;
5482	>	ReduceEntriesTask
5483	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5484	>	ReduceEntriesTask<K,V> nextRight,
5485	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5486	>	super(p, b, i, f, t); this.nextRight = nextRight;
5487	>	this.reducer = reducer;
5488	>	}
5489	>	public final Map.Entry<K,V> getRawResult() { return result; }
5490	>	public final void compute() {
5491	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5492	>	if ((reducer = this.reducer) != null) {
5493	>	for (int i = baseIndex, f, h; batch > 0 &&
5494	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5495	>	addToPendingCount(1);
5496	>	(rights = new ReduceEntriesTask<K,V>
5497	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5498	>	rights, reducer)).fork();
5499	>	}
5500	>	Map.Entry<K,V> r = null;
5501	>	for (Node<K,V> p; (p = advance()) != null; )
5502	>	r = (r == null) ? p : reducer.apply(r, p);
5503	>	result = r;
5504	>	CountedCompleter<?> c;
5505	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5506	>	@SuppressWarnings("unchecked")
5507	>	ReduceEntriesTask<K,V>
5508	>	t = (ReduceEntriesTask<K,V>)c,
5509	>	s = t.rights;
5510	>	while (s != null) {
5511	>	Map.Entry<K,V> tr, sr;
5512	>	if ((sr = s.result) != null)
5513	>	t.result = (((tr = t.result) == null) ? sr :
5514	>	reducer.apply(tr, sr));
5515	>	s = t.rights = s.nextRight;
5516	>	}
5517	>	}
5518	>	}
5519	>	}
5520	>	}
5521	>
5522	>	@SuppressWarnings("serial")
5523	>	static final class MapReduceKeysTask<K,V,U>
5524	>	extends BulkTask<K,V,U> {
5525	>	final Function<? super K, ? extends U> transformer;
5526	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5527	>	U result;
5528	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5529	>	MapReduceKeysTask
5530	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5531	>	MapReduceKeysTask<K,V,U> nextRight,
5532	>	Function<? super K, ? extends U> transformer,
5533	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5534	>	super(p, b, i, f, t); this.nextRight = nextRight;
5535	>	this.transformer = transformer;
5536	>	this.reducer = reducer;
5537	>	}
5538	>	public final U getRawResult() { return result; }
5539	>	public final void compute() {
5540	>	final Function<? super K, ? extends U> transformer;
5541	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5542	>	if ((transformer = this.transformer) != null &&
5543	>	(reducer = this.reducer) != null) {
5544	>	for (int i = baseIndex, f, h; batch > 0 &&
5545	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5546	>	addToPendingCount(1);
5547	>	(rights = new MapReduceKeysTask<K,V,U>
5548	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5549	>	rights, transformer, reducer)).fork();
5550	>	}
5551	>	U r = null;
5552	>	for (Node<K,V> p; (p = advance()) != null; ) {
5553	>	U u;
5554	>	if ((u = transformer.apply(p.key)) != null)
5555	>	r = (r == null) ? u : reducer.apply(r, u);
5556	>	}
5557	>	result = r;
5558	>	CountedCompleter<?> c;
5559	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5560	>	@SuppressWarnings("unchecked")
5561	>	MapReduceKeysTask<K,V,U>
5562	>	t = (MapReduceKeysTask<K,V,U>)c,
5563	>	s = t.rights;
5564	>	while (s != null) {
5565	>	U tr, sr;
5566	>	if ((sr = s.result) != null)
5567	>	t.result = (((tr = t.result) == null) ? sr :
5568	>	reducer.apply(tr, sr));
5569	>	s = t.rights = s.nextRight;
5570	>	}
5571	>	}
5572	>	}
5573	>	}
5574	>	}
5575	>
5576	>	@SuppressWarnings("serial")
5577	>	static final class MapReduceValuesTask<K,V,U>
5578	>	extends BulkTask<K,V,U> {
5579	>	final Function<? super V, ? extends U> transformer;
5580	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5581	>	U result;
5582	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5583	>	MapReduceValuesTask
5584	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5585	>	MapReduceValuesTask<K,V,U> nextRight,
5586	>	Function<? super V, ? extends U> transformer,
5587	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5588	>	super(p, b, i, f, t); this.nextRight = nextRight;
5589	>	this.transformer = transformer;
5590	>	this.reducer = reducer;
5591	>	}
5592	>	public final U getRawResult() { return result; }
5593	>	public final void compute() {
5594	>	final Function<? super V, ? extends U> transformer;
5595	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5596	>	if ((transformer = this.transformer) != null &&
5597	>	(reducer = this.reducer) != null) {
5598	>	for (int i = baseIndex, f, h; batch > 0 &&
5599	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5600	>	addToPendingCount(1);
5601	>	(rights = new MapReduceValuesTask<K,V,U>
5602	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5603	>	rights, transformer, reducer)).fork();
5604	>	}
5605	>	U r = null;
5606	>	for (Node<K,V> p; (p = advance()) != null; ) {
5607	>	U u;
5608	>	if ((u = transformer.apply(p.val)) != null)
5609	>	r = (r == null) ? u : reducer.apply(r, u);
5610	>	}
5611	>	result = r;
5612	>	CountedCompleter<?> c;
5613	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5614	>	@SuppressWarnings("unchecked")
5615	>	MapReduceValuesTask<K,V,U>
5616	>	t = (MapReduceValuesTask<K,V,U>)c,
5617	>	s = t.rights;
5618	>	while (s != null) {
5619	>	U tr, sr;
5620	>	if ((sr = s.result) != null)
5621	>	t.result = (((tr = t.result) == null) ? sr :
5622	>	reducer.apply(tr, sr));
5623	>	s = t.rights = s.nextRight;
5624	>	}
5625	>	}
5626	>	}
5627	>	}
5628	>	}
5629	>
5630	>	@SuppressWarnings("serial")
5631	>	static final class MapReduceEntriesTask<K,V,U>
5632	>	extends BulkTask<K,V,U> {
5633	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5634	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5635	>	U result;
5636	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5637	>	MapReduceEntriesTask
5638	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5639	>	MapReduceEntriesTask<K,V,U> nextRight,
5640	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5641	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5642	>	super(p, b, i, f, t); this.nextRight = nextRight;
5643	>	this.transformer = transformer;
5644	>	this.reducer = reducer;
5645	>	}
5646	>	public final U getRawResult() { return result; }
5647	>	public final void compute() {
5648	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5649	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5650	>	if ((transformer = this.transformer) != null &&
5651	>	(reducer = this.reducer) != null) {
5652	>	for (int i = baseIndex, f, h; batch > 0 &&
5653	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5654	>	addToPendingCount(1);
5655	>	(rights = new MapReduceEntriesTask<K,V,U>
5656	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5657	>	rights, transformer, reducer)).fork();
5658	>	}
5659	>	U r = null;
5660	>	for (Node<K,V> p; (p = advance()) != null; ) {
5661	>	U u;
5662	>	if ((u = transformer.apply(p)) != null)
5663	>	r = (r == null) ? u : reducer.apply(r, u);
5664	>	}
5665	>	result = r;
5666	>	CountedCompleter<?> c;
5667	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5668	>	@SuppressWarnings("unchecked")
5669	>	MapReduceEntriesTask<K,V,U>
5670	>	t = (MapReduceEntriesTask<K,V,U>)c,
5671	>	s = t.rights;
5672	>	while (s != null) {
5673	>	U tr, sr;
5674	>	if ((sr = s.result) != null)
5675	>	t.result = (((tr = t.result) == null) ? sr :
5676	>	reducer.apply(tr, sr));
5677	>	s = t.rights = s.nextRight;
5678	>	}
5679	>	}
5680	>	}
5681	>	}
5682	>	}
5683	>
5684	>	@SuppressWarnings("serial")
5685	>	static final class MapReduceMappingsTask<K,V,U>
5686	>	extends BulkTask<K,V,U> {
5687	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5688	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5689	>	U result;
5690	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5691	>	MapReduceMappingsTask
5692	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5693	>	MapReduceMappingsTask<K,V,U> nextRight,
5694	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5695	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5696	>	super(p, b, i, f, t); this.nextRight = nextRight;
5697	>	this.transformer = transformer;
5698	>	this.reducer = reducer;
5699	>	}
5700	>	public final U getRawResult() { return result; }
5701	>	public final void compute() {
5702	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5703	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5704	>	if ((transformer = this.transformer) != null &&
5705	>	(reducer = this.reducer) != null) {
5706	>	for (int i = baseIndex, f, h; batch > 0 &&
5707	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5708	>	addToPendingCount(1);
5709	>	(rights = new MapReduceMappingsTask<K,V,U>
5710	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5711	>	rights, transformer, reducer)).fork();
5712	>	}
5713	>	U r = null;
5714	>	for (Node<K,V> p; (p = advance()) != null; ) {
5715	>	U u;
5716	>	if ((u = transformer.apply(p.key, p.val)) != null)
5717	>	r = (r == null) ? u : reducer.apply(r, u);
5718	>	}
5719	>	result = r;
5720	>	CountedCompleter<?> c;
5721	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5722	>	@SuppressWarnings("unchecked")
5723	>	MapReduceMappingsTask<K,V,U>
5724	>	t = (MapReduceMappingsTask<K,V,U>)c,
5725	>	s = t.rights;
5726	>	while (s != null) {
5727	>	U tr, sr;
5728	>	if ((sr = s.result) != null)
5729	>	t.result = (((tr = t.result) == null) ? sr :
5730	>	reducer.apply(tr, sr));
5731	>	s = t.rights = s.nextRight;
5732	>	}
5733	>	}
5734	>	}
5735	>	}
5736	>	}
5737	>
5738	>	@SuppressWarnings("serial")
5739	>	static final class MapReduceKeysToDoubleTask<K,V>
5740	>	extends BulkTask<K,V,Double> {
5741	>	final ToDoubleFunction<? super K> transformer;
5742	>	final DoubleBinaryOperator reducer;
5743	>	final double basis;
5744	>	double result;
5745	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5746	>	MapReduceKeysToDoubleTask
5747	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5748	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5749	>	ToDoubleFunction<? super K> transformer,
5750	>	double basis,
5751	>	DoubleBinaryOperator reducer) {
5752	>	super(p, b, i, f, t); this.nextRight = nextRight;
5753	>	this.transformer = transformer;
5754	>	this.basis = basis; this.reducer = reducer;
5755	>	}
5756	>	public final Double getRawResult() { return result; }
5757	>	public final void compute() {
5758	>	final ToDoubleFunction<? super K> transformer;
5759	>	final DoubleBinaryOperator reducer;
5760	>	if ((transformer = this.transformer) != null &&
5761	>	(reducer = this.reducer) != null) {
5762	>	double r = this.basis;
5763	>	for (int i = baseIndex, f, h; batch > 0 &&
5764	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5765	>	addToPendingCount(1);
5766	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5767	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5768	>	rights, transformer, r, reducer)).fork();
5769	>	}
5770	>	for (Node<K,V> p; (p = advance()) != null; )
5771	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5772	>	result = r;
5773	>	CountedCompleter<?> c;
5774	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5775	>	@SuppressWarnings("unchecked")
5776	>	MapReduceKeysToDoubleTask<K,V>
5777	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5778	>	s = t.rights;
5779	>	while (s != null) {
5780	>	t.result = reducer.applyAsDouble(t.result, s.result);
5781	>	s = t.rights = s.nextRight;
5782	>	}
5783	>	}
5784	>	}
5785	>	}
5786	>	}
5787	>
5788	>	@SuppressWarnings("serial")
5789	>	static final class MapReduceValuesToDoubleTask<K,V>
5790	>	extends BulkTask<K,V,Double> {
5791	>	final ToDoubleFunction<? super V> transformer;
5792	>	final DoubleBinaryOperator reducer;
5793	>	final double basis;
5794	>	double result;
5795	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5796	>	MapReduceValuesToDoubleTask
5797	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5798	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5799	>	ToDoubleFunction<? super V> transformer,
5800	>	double basis,
5801	>	DoubleBinaryOperator reducer) {
5802	>	super(p, b, i, f, t); this.nextRight = nextRight;
5803	>	this.transformer = transformer;
5804	>	this.basis = basis; this.reducer = reducer;
5805	>	}
5806	>	public final Double getRawResult() { return result; }
5807	>	public final void compute() {
5808	>	final ToDoubleFunction<? super V> transformer;
5809	>	final DoubleBinaryOperator reducer;
5810	>	if ((transformer = this.transformer) != null &&
5811	>	(reducer = this.reducer) != null) {
5812	>	double r = this.basis;
5813	>	for (int i = baseIndex, f, h; batch > 0 &&
5814	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5815	>	addToPendingCount(1);
5816	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5817	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5818	>	rights, transformer, r, reducer)).fork();
5819	>	}
5820	>	for (Node<K,V> p; (p = advance()) != null; )
5821	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5822	>	result = r;
5823	>	CountedCompleter<?> c;
5824	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5825	>	@SuppressWarnings("unchecked")
5826	>	MapReduceValuesToDoubleTask<K,V>
5827	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5828	>	s = t.rights;
5829	>	while (s != null) {
5830	>	t.result = reducer.applyAsDouble(t.result, s.result);
5831	>	s = t.rights = s.nextRight;
5832	>	}
5833	>	}
5834	>	}
5835	>	}
5836	>	}
5837	>
5838	>	@SuppressWarnings("serial")
5839	>	static final class MapReduceEntriesToDoubleTask<K,V>
5840	>	extends BulkTask<K,V,Double> {
5841	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5842	>	final DoubleBinaryOperator reducer;
5843	>	final double basis;
5844	>	double result;
5845	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5846	>	MapReduceEntriesToDoubleTask
5847	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5848	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5849	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5850	>	double basis,
5851	>	DoubleBinaryOperator reducer) {
5852	>	super(p, b, i, f, t); this.nextRight = nextRight;
5853	>	this.transformer = transformer;
5854	>	this.basis = basis; this.reducer = reducer;
5855	>	}
5856	>	public final Double getRawResult() { return result; }
5857	>	public final void compute() {
5858	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5859	>	final DoubleBinaryOperator reducer;
5860	>	if ((transformer = this.transformer) != null &&
5861	>	(reducer = this.reducer) != null) {
5862	>	double r = this.basis;
5863	>	for (int i = baseIndex, f, h; batch > 0 &&
5864	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5865	>	addToPendingCount(1);
5866	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5867	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5868	>	rights, transformer, r, reducer)).fork();
5869	>	}
5870	>	for (Node<K,V> p; (p = advance()) != null; )
5871	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5872	>	result = r;
5873	>	CountedCompleter<?> c;
5874	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5875	>	@SuppressWarnings("unchecked")
5876	>	MapReduceEntriesToDoubleTask<K,V>
5877	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5878	>	s = t.rights;
5879	>	while (s != null) {
5880	>	t.result = reducer.applyAsDouble(t.result, s.result);
5881	>	s = t.rights = s.nextRight;
5882	>	}
5883	>	}
5884	>	}
5885	>	}
5886	>	}
5887	>
5888	>	@SuppressWarnings("serial")
5889	>	static final class MapReduceMappingsToDoubleTask<K,V>
5890	>	extends BulkTask<K,V,Double> {
5891	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5892	>	final DoubleBinaryOperator reducer;
5893	>	final double basis;
5894	>	double result;
5895	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5896	>	MapReduceMappingsToDoubleTask
5897	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5898	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5899	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5900	>	double basis,
5901	>	DoubleBinaryOperator reducer) {
5902	>	super(p, b, i, f, t); this.nextRight = nextRight;
5903	>	this.transformer = transformer;
5904	>	this.basis = basis; this.reducer = reducer;
5905	>	}
5906	>	public final Double getRawResult() { return result; }
5907	>	public final void compute() {
5908	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5909	>	final DoubleBinaryOperator reducer;
5910	>	if ((transformer = this.transformer) != null &&
5911	>	(reducer = this.reducer) != null) {
5912	>	double r = this.basis;
5913	>	for (int i = baseIndex, f, h; batch > 0 &&
5914	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5915	>	addToPendingCount(1);
5916	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5917	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5918	>	rights, transformer, r, reducer)).fork();
5919	>	}
5920	>	for (Node<K,V> p; (p = advance()) != null; )
5921	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5922	>	result = r;
5923	>	CountedCompleter<?> c;
5924	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5925	>	@SuppressWarnings("unchecked")
5926	>	MapReduceMappingsToDoubleTask<K,V>
5927	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5928	>	s = t.rights;
5929	>	while (s != null) {
5930	>	t.result = reducer.applyAsDouble(t.result, s.result);
5931	>	s = t.rights = s.nextRight;
5932	>	}
5933	>	}
5934	>	}
5935	>	}
5936	>	}
5937	>
5938	>	@SuppressWarnings("serial")
5939	>	static final class MapReduceKeysToLongTask<K,V>
5940	>	extends BulkTask<K,V,Long> {
5941	>	final ToLongFunction<? super K> transformer;
5942	>	final LongBinaryOperator reducer;
5943	>	final long basis;
5944	>	long result;
5945	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5946	>	MapReduceKeysToLongTask
5947	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5948	>	MapReduceKeysToLongTask<K,V> nextRight,
5949	>	ToLongFunction<? super K> transformer,
5950	>	long basis,
5951	>	LongBinaryOperator reducer) {
5952	>	super(p, b, i, f, t); this.nextRight = nextRight;
5953	>	this.transformer = transformer;
5954	>	this.basis = basis; this.reducer = reducer;
5955	>	}
5956	>	public final Long getRawResult() { return result; }
5957	>	public final void compute() {
5958	>	final ToLongFunction<? super K> transformer;
5959	>	final LongBinaryOperator reducer;
5960	>	if ((transformer = this.transformer) != null &&
5961	>	(reducer = this.reducer) != null) {
5962	>	long r = this.basis;
5963	>	for (int i = baseIndex, f, h; batch > 0 &&
5964	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5965	>	addToPendingCount(1);
5966	>	(rights = new MapReduceKeysToLongTask<K,V>
5967	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5968	>	rights, transformer, r, reducer)).fork();
5969	>	}
5970	>	for (Node<K,V> p; (p = advance()) != null; )
5971	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5972	>	result = r;
5973	>	CountedCompleter<?> c;
5974	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5975	>	@SuppressWarnings("unchecked")
5976	>	MapReduceKeysToLongTask<K,V>
5977	>	t = (MapReduceKeysToLongTask<K,V>)c,
5978	>	s = t.rights;
5979	>	while (s != null) {
5980	>	t.result = reducer.applyAsLong(t.result, s.result);
5981	>	s = t.rights = s.nextRight;
5982	>	}
5983	>	}
5984	>	}
5985	>	}
5986	>	}
5987	>
5988	>	@SuppressWarnings("serial")
5989	>	static final class MapReduceValuesToLongTask<K,V>
5990	>	extends BulkTask<K,V,Long> {
5991	>	final ToLongFunction<? super V> transformer;
5992	>	final LongBinaryOperator reducer;
5993	>	final long basis;
5994	>	long result;
5995	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5996	>	MapReduceValuesToLongTask
5997	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5998	>	MapReduceValuesToLongTask<K,V> nextRight,
5999	>	ToLongFunction<? super V> transformer,
6000	>	long basis,
6001	>	LongBinaryOperator reducer) {
6002	>	super(p, b, i, f, t); this.nextRight = nextRight;
6003	>	this.transformer = transformer;
6004	>	this.basis = basis; this.reducer = reducer;
6005	>	}
6006	>	public final Long getRawResult() { return result; }
6007	>	public final void compute() {
6008	>	final ToLongFunction<? super V> transformer;
6009	>	final LongBinaryOperator reducer;
6010	>	if ((transformer = this.transformer) != null &&
6011	>	(reducer = this.reducer) != null) {
6012	>	long r = this.basis;
6013	>	for (int i = baseIndex, f, h; batch > 0 &&
6014	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6015	>	addToPendingCount(1);
6016	>	(rights = new MapReduceValuesToLongTask<K,V>
6017	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6018	>	rights, transformer, r, reducer)).fork();
6019	>	}
6020	>	for (Node<K,V> p; (p = advance()) != null; )
6021	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
6022	>	result = r;
6023	>	CountedCompleter<?> c;
6024	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6025	>	@SuppressWarnings("unchecked")
6026	>	MapReduceValuesToLongTask<K,V>
6027	>	t = (MapReduceValuesToLongTask<K,V>)c,
6028	>	s = t.rights;
6029	>	while (s != null) {
6030	>	t.result = reducer.applyAsLong(t.result, s.result);
6031	>	s = t.rights = s.nextRight;
6032	>	}
6033	>	}
6034	>	}
6035	>	}
6036	>	}
6037	>
6038	>	@SuppressWarnings("serial")
6039	>	static final class MapReduceEntriesToLongTask<K,V>
6040	>	extends BulkTask<K,V,Long> {
6041	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6042	>	final LongBinaryOperator reducer;
6043	>	final long basis;
6044	>	long result;
6045	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6046	>	MapReduceEntriesToLongTask
6047	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6048	>	MapReduceEntriesToLongTask<K,V> nextRight,
6049	>	ToLongFunction<Map.Entry<K,V>> transformer,
6050	>	long basis,
6051	>	LongBinaryOperator reducer) {
6052	>	super(p, b, i, f, t); this.nextRight = nextRight;
6053	>	this.transformer = transformer;
6054	>	this.basis = basis; this.reducer = reducer;
6055	>	}
6056	>	public final Long getRawResult() { return result; }
6057	>	public final void compute() {
6058	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6059	>	final LongBinaryOperator reducer;
6060	>	if ((transformer = this.transformer) != null &&
6061	>	(reducer = this.reducer) != null) {
6062	>	long r = this.basis;
6063	>	for (int i = baseIndex, f, h; batch > 0 &&
6064	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6065	>	addToPendingCount(1);
6066	>	(rights = new MapReduceEntriesToLongTask<K,V>
6067	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6068	>	rights, transformer, r, reducer)).fork();
6069	>	}
6070	>	for (Node<K,V> p; (p = advance()) != null; )
6071	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6072	>	result = r;
6073	>	CountedCompleter<?> c;
6074	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6075	>	@SuppressWarnings("unchecked")
6076	>	MapReduceEntriesToLongTask<K,V>
6077	>	t = (MapReduceEntriesToLongTask<K,V>)c,
6078	>	s = t.rights;
6079	>	while (s != null) {
6080	>	t.result = reducer.applyAsLong(t.result, s.result);
6081	>	s = t.rights = s.nextRight;
6082	>	}
6083	>	}
6084	>	}
6085	>	}
6086	>	}
6087	>
6088	>	@SuppressWarnings("serial")
6089	>	static final class MapReduceMappingsToLongTask<K,V>
6090	>	extends BulkTask<K,V,Long> {
6091	>	final ToLongBiFunction<? super K, ? super V> transformer;
6092	>	final LongBinaryOperator reducer;
6093	>	final long basis;
6094	>	long result;
6095	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6096	>	MapReduceMappingsToLongTask
6097	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6098	>	MapReduceMappingsToLongTask<K,V> nextRight,
6099	>	ToLongBiFunction<? super K, ? super V> transformer,
6100	>	long basis,
6101	>	LongBinaryOperator reducer) {
6102	>	super(p, b, i, f, t); this.nextRight = nextRight;
6103	>	this.transformer = transformer;
6104	>	this.basis = basis; this.reducer = reducer;
6105	>	}
6106	>	public final Long getRawResult() { return result; }
6107	>	public final void compute() {
6108	>	final ToLongBiFunction<? super K, ? super V> transformer;
6109	>	final LongBinaryOperator reducer;
6110	>	if ((transformer = this.transformer) != null &&
6111	>	(reducer = this.reducer) != null) {
6112	>	long r = this.basis;
6113	>	for (int i = baseIndex, f, h; batch > 0 &&
6114	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6115	>	addToPendingCount(1);
6116	>	(rights = new MapReduceMappingsToLongTask<K,V>
6117	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6118	>	rights, transformer, r, reducer)).fork();
6119	>	}
6120	>	for (Node<K,V> p; (p = advance()) != null; )
6121	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6122	>	result = r;
6123	>	CountedCompleter<?> c;
6124	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6125	>	@SuppressWarnings("unchecked")
6126	>	MapReduceMappingsToLongTask<K,V>
6127	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6128	>	s = t.rights;
6129	>	while (s != null) {
6130	>	t.result = reducer.applyAsLong(t.result, s.result);
6131	>	s = t.rights = s.nextRight;
6132	>	}
6133	>	}
6134	>	}
6135	>	}
6136	>	}
6137	>
6138	>	@SuppressWarnings("serial")
6139	>	static final class MapReduceKeysToIntTask<K,V>
6140	>	extends BulkTask<K,V,Integer> {
6141	>	final ToIntFunction<? super K> transformer;
6142	>	final IntBinaryOperator reducer;
6143	>	final int basis;
6144	>	int result;
6145	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6146	>	MapReduceKeysToIntTask
6147	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6148	>	MapReduceKeysToIntTask<K,V> nextRight,
6149	>	ToIntFunction<? super K> transformer,
6150	>	int basis,
6151	>	IntBinaryOperator reducer) {
6152	>	super(p, b, i, f, t); this.nextRight = nextRight;
6153	>	this.transformer = transformer;
6154	>	this.basis = basis; this.reducer = reducer;
6155	>	}
6156	>	public final Integer getRawResult() { return result; }
6157	>	public final void compute() {
6158	>	final ToIntFunction<? super K> transformer;
6159	>	final IntBinaryOperator reducer;
6160	>	if ((transformer = this.transformer) != null &&
6161	>	(reducer = this.reducer) != null) {
6162	>	int r = this.basis;
6163	>	for (int i = baseIndex, f, h; batch > 0 &&
6164	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6165	>	addToPendingCount(1);
6166	>	(rights = new MapReduceKeysToIntTask<K,V>
6167	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6168	>	rights, transformer, r, reducer)).fork();
6169	>	}
6170	>	for (Node<K,V> p; (p = advance()) != null; )
6171	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6172	>	result = r;
6173	>	CountedCompleter<?> c;
6174	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6175	>	@SuppressWarnings("unchecked")
6176	>	MapReduceKeysToIntTask<K,V>
6177	>	t = (MapReduceKeysToIntTask<K,V>)c,
6178	>	s = t.rights;
6179	>	while (s != null) {
6180	>	t.result = reducer.applyAsInt(t.result, s.result);
6181	>	s = t.rights = s.nextRight;
6182	>	}
6183	>	}
6184	>	}
6185	>	}
6186	>	}
6187	>
6188	>	@SuppressWarnings("serial")
6189	>	static final class MapReduceValuesToIntTask<K,V>
6190	>	extends BulkTask<K,V,Integer> {
6191	>	final ToIntFunction<? super V> transformer;
6192	>	final IntBinaryOperator reducer;
6193	>	final int basis;
6194	>	int result;
6195	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6196	>	MapReduceValuesToIntTask
6197	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6198	>	MapReduceValuesToIntTask<K,V> nextRight,
6199	>	ToIntFunction<? super V> transformer,
6200	>	int basis,
6201	>	IntBinaryOperator reducer) {
6202	>	super(p, b, i, f, t); this.nextRight = nextRight;
6203	>	this.transformer = transformer;
6204	>	this.basis = basis; this.reducer = reducer;
6205	>	}
6206	>	public final Integer getRawResult() { return result; }
6207	>	public final void compute() {
6208	>	final ToIntFunction<? super V> transformer;
6209	>	final IntBinaryOperator reducer;
6210	>	if ((transformer = this.transformer) != null &&
6211	>	(reducer = this.reducer) != null) {
6212	>	int r = this.basis;
6213	>	for (int i = baseIndex, f, h; batch > 0 &&
6214	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6215	>	addToPendingCount(1);
6216	>	(rights = new MapReduceValuesToIntTask<K,V>
6217	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6218	>	rights, transformer, r, reducer)).fork();
6219	>	}
6220	>	for (Node<K,V> p; (p = advance()) != null; )
6221	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6222	>	result = r;
6223	>	CountedCompleter<?> c;
6224	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6225	>	@SuppressWarnings("unchecked")
6226	>	MapReduceValuesToIntTask<K,V>
6227	>	t = (MapReduceValuesToIntTask<K,V>)c,
6228	>	s = t.rights;
6229	>	while (s != null) {
6230	>	t.result = reducer.applyAsInt(t.result, s.result);
6231	>	s = t.rights = s.nextRight;
6232	>	}
6233	>	}
6234	>	}
6235	>	}
6236	>	}
6237	>
6238	>	@SuppressWarnings("serial")
6239	>	static final class MapReduceEntriesToIntTask<K,V>
6240	>	extends BulkTask<K,V,Integer> {
6241	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6242	>	final IntBinaryOperator reducer;
6243	>	final int basis;
6244	>	int result;
6245	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6246	>	MapReduceEntriesToIntTask
6247	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6248	>	MapReduceEntriesToIntTask<K,V> nextRight,
6249	>	ToIntFunction<Map.Entry<K,V>> transformer,
6250	>	int basis,
6251	>	IntBinaryOperator reducer) {
6252	>	super(p, b, i, f, t); this.nextRight = nextRight;
6253	>	this.transformer = transformer;
6254	>	this.basis = basis; this.reducer = reducer;
6255	>	}
6256	>	public final Integer getRawResult() { return result; }
6257	>	public final void compute() {
6258	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6259	>	final IntBinaryOperator reducer;
6260	>	if ((transformer = this.transformer) != null &&
6261	>	(reducer = this.reducer) != null) {
6262	>	int r = this.basis;
6263	>	for (int i = baseIndex, f, h; batch > 0 &&
6264	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6265	>	addToPendingCount(1);
6266	>	(rights = new MapReduceEntriesToIntTask<K,V>
6267	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6268	>	rights, transformer, r, reducer)).fork();
6269	>	}
6270	>	for (Node<K,V> p; (p = advance()) != null; )
6271	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6272	>	result = r;
6273	>	CountedCompleter<?> c;
6274	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6275	>	@SuppressWarnings("unchecked")
6276	>	MapReduceEntriesToIntTask<K,V>
6277	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6278	>	s = t.rights;
6279	>	while (s != null) {
6280	>	t.result = reducer.applyAsInt(t.result, s.result);
6281	>	s = t.rights = s.nextRight;
6282	>	}
6283	>	}
6284	>	}
6285	>	}
6286	>	}
6287	>
6288	>	@SuppressWarnings("serial")
6289	>	static final class MapReduceMappingsToIntTask<K,V>
6290	>	extends BulkTask<K,V,Integer> {
6291	>	final ToIntBiFunction<? super K, ? super V> transformer;
6292	>	final IntBinaryOperator reducer;
6293	>	final int basis;
6294	>	int result;
6295	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6296	>	MapReduceMappingsToIntTask
6297	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6298	>	MapReduceMappingsToIntTask<K,V> nextRight,
6299	>	ToIntBiFunction<? super K, ? super V> transformer,
6300	>	int basis,
6301	>	IntBinaryOperator reducer) {
6302	>	super(p, b, i, f, t); this.nextRight = nextRight;
6303	>	this.transformer = transformer;
6304	>	this.basis = basis; this.reducer = reducer;
6305	>	}
6306	>	public final Integer getRawResult() { return result; }
6307	>	public final void compute() {
6308	>	final ToIntBiFunction<? super K, ? super V> transformer;
6309	>	final IntBinaryOperator reducer;
6310	>	if ((transformer = this.transformer) != null &&
6311	>	(reducer = this.reducer) != null) {
6312	>	int r = this.basis;
6313	>	for (int i = baseIndex, f, h; batch > 0 &&
6314	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6315	>	addToPendingCount(1);
6316	>	(rights = new MapReduceMappingsToIntTask<K,V>
6317	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6318	>	rights, transformer, r, reducer)).fork();
6319	>	}
6320	>	for (Node<K,V> p; (p = advance()) != null; )
6321	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6322	>	result = r;
6323	>	CountedCompleter<?> c;
6324	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6325	>	@SuppressWarnings("unchecked")
6326	>	MapReduceMappingsToIntTask<K,V>
6327	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6328	>	s = t.rights;
6329	>	while (s != null) {
6330	>	t.result = reducer.applyAsInt(t.result, s.result);
6331	>	s = t.rights = s.nextRight;
6332	>	}
6333	>	}
6334	>	}
6335		}
6336		}
6337
6338		// Unsafe mechanics
6339	<	private static final sun.misc.Unsafe UNSAFE;
6340	<	private static final long SBASE;
6341	<	private static final int SSHIFT;
6342	<	private static final long TBASE;
6343	<	private static final int TSHIFT;
6339	>	private static final Unsafe U = Unsafe.getUnsafe();
6340	>	private static final long SIZECTL;
6341	>	private static final long TRANSFERINDEX;
6342	>	private static final long BASECOUNT;
6343	>	private static final long CELLSBUSY;
6344	>	private static final long CELLVALUE;
6345	>	private static final int ABASE;
6346	>	private static final int ASHIFT;
6347
6348		static {
1466	–	int ss, ts;
6349		try {
6350	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6351	<	Class<?> tc = HashEntry[].class;
6352	<	Class<?> sc = Segment[].class;
6353	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6354	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6355	<	ts = UNSAFE.arrayIndexScale(tc);
6356	<	ss = UNSAFE.arrayIndexScale(sc);
6357	<	} catch (Exception e) {
6358	<	throw new Error(e);
6359	<	}
6360	<	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
6361	<	throw new Error("data type scale not a power of two");
6362	<	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
6363	<	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6350	>	SIZECTL = U.objectFieldOffset
6351	>	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6352	>	TRANSFERINDEX = U.objectFieldOffset
6353	>	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6354	>	BASECOUNT = U.objectFieldOffset
6355	>	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6356	>	CELLSBUSY = U.objectFieldOffset
6357	>	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6358	>
6359	>	CELLVALUE = U.objectFieldOffset
6360	>	(CounterCell.class.getDeclaredField("value"));
6361	>
6362	>	ABASE = U.arrayBaseOffset(Node[].class);
6363	>	int scale = U.arrayIndexScale(Node[].class);
6364	>	if ((scale & (scale - 1)) != 0)
6365	>	throw new ExceptionInInitializerError("array index scale not a power of two");
6366	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6367	>	} catch (ReflectiveOperationException e) {
6368	>	throw new ExceptionInInitializerError(e);
6369	>	}
6370	>
6371	>	// Reduce the risk of rare disastrous classloading in first call to
6372	>	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6373	>	Class<?> ensureLoaded = LockSupport.class;
6374		}
1483	–
6375		}

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