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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.115 by jsr166, Fri Dec 2 14:28:17 2011 UTC vs.
Revision 1.315 by dl, Wed Nov 28 23:52:49 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.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
42	<	* vary.  Ideally, you should choose a value to accommodate as many
43	<	* threads as will ever concurrently modify the table. Using a
44	<	* significantly higher value than you need can waste space and time,
45	<	* and a significantly lower value can lead to thread contention. But
46	<	* overestimates and underestimates within an order of magnitude do
47	<	* not usually have much noticeable impact. A value of one is
48	<	* appropriate when it is known that only one thread will modify and
49	<	* all others will only read. Also, resizing this or any other kind of
50	<	* hash table is a relatively slow operation, so, when possible, it is
51	<	* a good idea to provide estimates of expected table sizes in
52	<	* 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.base/java/util/package-summary.html#CollectionsFramework">
228		* Java Collections Framework</a>.
229		*
230		* @since 1.5
#	Line 67 | Line 232 | import java.io.Serializable;
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
120	<	* be a power of two <= 1<<30 to ensure that entries are indexable
121	<	* 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
142	<	* 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;
145	<
146	<	/* ---------------- 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
187	<	* 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 = -1 >>> Integer.numberOfLeadingZeros(c - 1);
677	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
678	>	}
679	>
680	>	/**
681	>	* Returns x's Class if it is of the form "class C implements
682	>	* Comparable<C>", else null.
683	>	*/
684	>	static Class<?> comparableClassFor(Object x) {
685	>	if (x instanceof Comparable) {
686	>	Class<?> c; Type[] ts, as; ParameterizedType p;
687	>	if ((c = x.getClass()) == String.class) // bypass checks
688	>	return c;
689	>	if ((ts = c.getGenericInterfaces()) != null) {
690	>	for (Type t : ts) {
691	>	if ((t instanceof ParameterizedType) &&
692	>	((p = (ParameterizedType)t).getRawType() ==
693	>	Comparable.class) &&
694	>	(as = p.getActualTypeArguments()) != null &&
695	>	as.length == 1 && as[0] == c) // type arg is c
696	>	return c;
697	>	}
698		}
699		}
700	+	return null;
701		}
702
703		/**
704	<	* Gets the ith element of given table (if nonnull) with volatile
705	<	* read semantics. Note: This is manually integrated into a few
211	<	* performance-sensitive methods to reduce call overhead.
704	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
705	>	* class), else 0.
706		*/
707	+	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
708	+	static int compareComparables(Class<?> kc, Object k, Object x) {
709	+	return (x == null || x.getClass() != kc ? 0 :
710	+	((Comparable)k).compareTo(x));
711	+	}
712	+
713	+	/* ---------------- Table element access -------------- */
714	+
715	+	/*
716	+	* Atomic access methods are used for table elements as well as
717	+	* elements of in-progress next table while resizing.  All uses of
718	+	* the tab arguments must be null checked by callers.  All callers
719	+	* also paranoically precheck that tab's length is not zero (or an
720	+	* equivalent check), thus ensuring that any index argument taking
721	+	* the form of a hash value anded with (length - 1) is a valid
722	+	* index.  Note that, to be correct wrt arbitrary concurrency
723	+	* errors by users, these checks must operate on local variables,
724	+	* which accounts for some odd-looking inline assignments below.
725	+	* Note that calls to setTabAt always occur within locked regions,
726	+	* and so require only release ordering.
727	+	*/
728	+
729		@SuppressWarnings("unchecked")
730	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
731	<	return (tab == null) ? null :
732	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
733	<	(tab, ((long)i << TSHIFT) + TBASE);
730	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
731	>	return (Node<K,V>)U.getObjectAcquire(tab, ((long)i << ASHIFT) + ABASE);
732	>	}
733	>
734	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
735	>	Node<K,V> c, Node<K,V> v) {
736	>	return U.compareAndSetObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
737		}
738
739	+	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
740	+	U.putObjectRelease(tab, ((long)i << ASHIFT) + ABASE, v);
741	+	}
742	+
743	+	/* ---------------- Fields -------------- */
744	+
745	+	/**
746	+	* The array of bins. Lazily initialized upon first insertion.
747	+	* Size is always a power of two. Accessed directly by iterators.
748	+	*/
749	+	transient volatile Node<K,V>[] table;
750	+
751	+	/**
752	+	* The next table to use; non-null only while resizing.
753	+	*/
754	+	private transient volatile Node<K,V>[] nextTable;
755	+
756	+	/**
757	+	* Base counter value, used mainly when there is no contention,
758	+	* but also as a fallback during table initialization
759	+	* races. Updated via CAS.
760	+	*/
761	+	private transient volatile long baseCount;
762	+
763	+	/**
764	+	* Table initialization and resizing control.  When negative, the
765	+	* table is being initialized or resized: -1 for initialization,
766	+	* else -(1 + the number of active resizing threads).  Otherwise,
767	+	* when table is null, holds the initial table size to use upon
768	+	* creation, or 0 for default. After initialization, holds the
769	+	* next element count value upon which to resize the table.
770	+	*/
771	+	private transient volatile int sizeCtl;
772	+
773	+	/**
774	+	* The next table index (plus one) to split while resizing.
775	+	*/
776	+	private transient volatile int transferIndex;
777	+
778	+	/**
779	+	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
780	+	*/
781	+	private transient volatile int cellsBusy;
782	+
783	+	/**
784	+	* Table of counter cells. When non-null, size is a power of 2.
785	+	*/
786	+	private transient volatile CounterCell[] counterCells;
787	+
788	+	// views
789	+	private transient KeySetView<K,V> keySet;
790	+	private transient ValuesView<K,V> values;
791	+	private transient EntrySetView<K,V> entrySet;
792	+
793	+
794	+	/* ---------------- Public operations -------------- */
795	+
796		/**
797	<	* Sets the ith element of given table, with volatile write
222	<	* semantics. (See above about use of putOrderedObject.)
797	>	* Creates a new, empty map with the default initial table size (16).
798		*/
799	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
225	<	HashEntry<K,V> e) {
226	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
799	>	public ConcurrentHashMap() {
800		}
801
802		/**
803	<	* Applies a supplemental hash function to a given hashCode, which
804	<	* defends against poor quality hash functions.  This is critical
805	<	* because ConcurrentHashMap uses power-of-two length hash tables,
806	<	* that otherwise encounter collisions for hashCodes that do not
807	<	* differ in lower or upper bits.
803	>	* Creates a new, empty map with an initial table size
804	>	* accommodating the specified number of elements without the need
805	>	* to dynamically resize.
806	>	*
807	>	* @param initialCapacity The implementation performs internal
808	>	* sizing to accommodate this many elements.
809	>	* @throws IllegalArgumentException if the initial capacity of
810	>	* elements is negative
811		*/
812	<	private static int hash(int h) {
813	<	// Spread bits to regularize both segment and index locations,
238	<	// using variant of single-word Wang/Jenkins hash.
239	<	h += (h <<  15) ^ 0xffffcd7d;
240	<	h ^= (h >>> 10);
241	<	h += (h <<   3);
242	<	h ^= (h >>>  6);
243	<	h += (h <<   2) + (h << 14);
244	<	return h ^ (h >>> 16);
812	>	public ConcurrentHashMap(int initialCapacity) {
813	>	this(initialCapacity, LOAD_FACTOR, 1);
814		}
815
816		/**
817	<	* Segments are specialized versions of hash tables.  This
818	<	* subclasses from ReentrantLock opportunistically, just to
819	<	* simplify some locking and avoid separate construction.
817	>	* Creates a new map with the same mappings as the given map.
818	>	*
819	>	* @param m the map
820		*/
821	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
822	<	/*
823	<	* Segments maintain a table of entry lists that are always
824	<	* kept in a consistent state, so can be read (via volatile
256	<	* reads of segments and tables) without locking.  This
257	<	* requires replicating nodes when necessary during table
258	<	* resizing, so the old lists can be traversed by readers
259	<	* still using old version of table.
260	<	*
261	<	* This class defines only mutative methods requiring locking.
262	<	* Except as noted, the methods of this class perform the
263	<	* per-segment versions of ConcurrentHashMap methods.  (Other
264	<	* methods are integrated directly into ConcurrentHashMap
265	<	* methods.) These mutative methods use a form of controlled
266	<	* spinning on contention via methods scanAndLock and
267	<	* scanAndLockForPut. These intersperse tryLocks with
268	<	* traversals to locate nodes.  The main benefit is to absorb
269	<	* cache misses (which are very common for hash tables) while
270	<	* obtaining locks so that traversal is faster once
271	<	* acquired. We do not actually use the found nodes since they
272	<	* must be re-acquired under lock anyway to ensure sequential
273	<	* consistency of updates (and in any case may be undetectably
274	<	* stale), but they will normally be much faster to re-locate.
275	<	* Also, scanAndLockForPut speculatively creates a fresh node
276	<	* to use in put if no node is found.
277	<	*/
821	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
822	>	this.sizeCtl = DEFAULT_CAPACITY;
823	>	putAll(m);
824	>	}
825
826	<	private static final long serialVersionUID = 2249069246763182397L;
826	>	/**
827	>	* Creates a new, empty map with an initial table size based on
828	>	* the given number of elements ({@code initialCapacity}) and
829	>	* initial table density ({@code loadFactor}).
830	>	*
831	>	* @param initialCapacity the initial capacity. The implementation
832	>	* performs internal sizing to accommodate this many elements,
833	>	* given the specified load factor.
834	>	* @param loadFactor the load factor (table density) for
835	>	* establishing the initial table size
836	>	* @throws IllegalArgumentException if the initial capacity of
837	>	* elements is negative or the load factor is nonpositive
838	>	*
839	>	* @since 1.6
840	>	*/
841	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
842	>	this(initialCapacity, loadFactor, 1);
843	>	}
844
845	<	/**
846	<	* The maximum number of times to tryLock in a prescan before
847	<	* possibly blocking on acquire in preparation for a locked
848	<	* segment operation. On multiprocessors, using a bounded
849	<	* number of retries maintains cache acquired while locating
850	<	* nodes.
851	<	*/
852	<	static final int MAX_SCAN_RETRIES =
853	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
845	>	/**
846	>	* Creates a new, empty map with an initial table size based on
847	>	* the given number of elements ({@code initialCapacity}), initial
848	>	* table density ({@code loadFactor}), and number of concurrently
849	>	* updating threads ({@code concurrencyLevel}).
850	>	*
851	>	* @param initialCapacity the initial capacity. The implementation
852	>	* performs internal sizing to accommodate this many elements,
853	>	* given the specified load factor.
854	>	* @param loadFactor the load factor (table density) for
855	>	* establishing the initial table size
856	>	* @param concurrencyLevel the estimated number of concurrently
857	>	* updating threads. The implementation may use this value as
858	>	* a sizing hint.
859	>	* @throws IllegalArgumentException if the initial capacity is
860	>	* negative or the load factor or concurrencyLevel are
861	>	* nonpositive
862	>	*/
863	>	public ConcurrentHashMap(int initialCapacity,
864	>	float loadFactor, int concurrencyLevel) {
865	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
866	>	throw new IllegalArgumentException();
867	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
868	>	initialCapacity = concurrencyLevel;   // as estimated threads
869	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
870	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
871	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
872	>	this.sizeCtl = cap;
873	>	}
874
875	<	/**
292	<	* The per-segment table. Elements are accessed via
293	<	* entryAt/setEntryAt providing volatile semantics.
294	<	*/
295	<	transient volatile HashEntry<K,V>[] table;
875	>	// Original (since JDK1.2) Map methods
876
877	<	/**
878	<	* The number of elements. Accessed only either within locks
879	<	* or among other volatile reads that maintain visibility.
880	<	*/
881	<	transient int count;
877	>	/**
878	>	* {@inheritDoc}
879	>	*/
880	>	public int size() {
881	>	long n = sumCount();
882	>	return ((n < 0L) ? 0 :
883	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
884	>	(int)n);
885	>	}
886
887	<	/**
888	<	* The total number of mutative operations in this segment.
889	<	* Even though this may overflows 32 bits, it provides
890	<	* sufficient accuracy for stability checks in CHM isEmpty()
891	<	* and size() methods.  Accessed only either within locks or
892	<	* among other volatile reads that maintain visibility.
309	<	*/
310	<	transient int modCount;
887	>	/**
888	>	* {@inheritDoc}
889	>	*/
890	>	public boolean isEmpty() {
891	>	return sumCount() <= 0L; // ignore transient negative values
892	>	}
893
894	<	/**
895	<	* The table is rehashed when its size exceeds this threshold.
896	<	* (The value of this field is always <tt>(int)(capacity *
897	<	* loadFactor)</tt>.)
898	<	*/
899	<	transient int threshold;
894	>	/**
895	>	* Returns the value to which the specified key is mapped,
896	>	* or {@code null} if this map contains no mapping for the key.
897	>	*
898	>	* <p>More formally, if this map contains a mapping from a key
899	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
900	>	* then this method returns {@code v}; otherwise it returns
901	>	* {@code null}.  (There can be at most one such mapping.)
902	>	*
903	>	* @throws NullPointerException if the specified key is null
904	>	*/
905	>	public V get(Object key) {
906	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
907	>	int h = spread(key.hashCode());
908	>	if ((tab = table) != null && (n = tab.length) > 0 &&
909	>	(e = tabAt(tab, (n - 1) & h)) != null) {
910	>	if ((eh = e.hash) == h) {
911	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
912	>	return e.val;
913	>	}
914	>	else if (eh < 0)
915	>	return (p = e.find(h, key)) != null ? p.val : null;
916	>	while ((e = e.next) != null) {
917	>	if (e.hash == h &&
918	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
919	>	return e.val;
920	>	}
921	>	}
922	>	return null;
923	>	}
924
925	<	/**
926	<	* The load factor for the hash table.  Even though this value
927	<	* is same for all segments, it is replicated to avoid needing
928	<	* links to outer object.
929	<	* @serial
930	<	*/
931	<	final float loadFactor;
925	>	/**
926	>	* Tests if the specified object is a key in this table.
927	>	*
928	>	* @param  key possible key
929	>	* @return {@code true} if and only if the specified object
930	>	*         is a key in this table, as determined by the
931	>	*         {@code equals} method; {@code false} otherwise
932	>	* @throws NullPointerException if the specified key is null
933	>	*/
934	>	public boolean containsKey(Object key) {
935	>	return get(key) != null;
936	>	}
937
938	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
939	<	this.loadFactor = lf;
940	<	this.threshold = threshold;
941	<	this.table = tab;
938	>	/**
939	>	* Returns {@code true} if this map maps one or more keys to the
940	>	* specified value. Note: This method may require a full traversal
941	>	* of the map, and is much slower than method {@code containsKey}.
942	>	*
943	>	* @param value value whose presence in this map is to be tested
944	>	* @return {@code true} if this map maps one or more keys to the
945	>	*         specified value
946	>	* @throws NullPointerException if the specified value is null
947	>	*/
948	>	public boolean containsValue(Object value) {
949	>	if (value == null)
950	>	throw new NullPointerException();
951	>	Node<K,V>[] t;
952	>	if ((t = table) != null) {
953	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
954	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
955	>	V v;
956	>	if ((v = p.val) == value || (v != null && value.equals(v)))
957	>	return true;
958	>	}
959		}
960	+	return false;
961	+	}
962
963	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
964	<	HashEntry<K,V> node = tryLock() ? null :
965	<	scanAndLockForPut(key, hash, value);
966	<	V oldValue;
967	<	try {
968	<	HashEntry<K,V>[] tab = table;
969	<	int index = (tab.length - 1) & hash;
970	<	HashEntry<K,V> first = entryAt(tab, index);
971	<	for (HashEntry<K,V> e = first;;) {
972	<	if (e != null) {
973	<	K k;
974	<	if ((k = e.key) == key ||
975	<	(e.hash == hash && key.equals(k))) {
976	<	oldValue = e.value;
977	<	if (!onlyIfAbsent) {
978	<	e.value = value;
979	<	++modCount;
963	>	/**
964	>	* Maps the specified key to the specified value in this table.
965	>	* Neither the key nor the value can be null.
966	>	*
967	>	* <p>The value can be retrieved by calling the {@code get} method
968	>	* with a key that is equal to the original key.
969	>	*
970	>	* @param key key with which the specified value is to be associated
971	>	* @param value value to be associated with the specified key
972	>	* @return the previous value associated with {@code key}, or
973	>	*         {@code null} if there was no mapping for {@code key}
974	>	* @throws NullPointerException if the specified key or value is null
975	>	*/
976	>	public V put(K key, V value) {
977	>	return putVal(key, value, false);
978	>	}
979	>
980	>	/** Implementation for put and putIfAbsent */
981	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
982	>	if (key == null || value == null) throw new NullPointerException();
983	>	int hash = spread(key.hashCode());
984	>	int binCount = 0;
985	>	for (Node<K,V>[] tab = table;;) {
986	>	Node<K,V> f; int n, i, fh; K fk; V fv;
987	>	if (tab == null || (n = tab.length) == 0)
988	>	tab = initTable();
989	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
990	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
991	>	break;                   // no lock when adding to empty bin
992	>	}
993	>	else if ((fh = f.hash) == MOVED)
994	>	tab = helpTransfer(tab, f);
995	>	else if (onlyIfAbsent // check first node without acquiring lock
996	>	&& fh == hash
997	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
998	>	&& (fv = f.val) != null)
999	>	return fv;
1000	>	else {
1001	>	V oldVal = null;
1002	>	synchronized (f) {
1003	>	if (tabAt(tab, i) == f) {
1004	>	if (fh >= 0) {
1005	>	binCount = 1;
1006	>	for (Node<K,V> e = f;; ++binCount) {
1007	>	K ek;
1008	>	if (e.hash == hash &&
1009	>	((ek = e.key) == key ||
1010	>	(ek != null && key.equals(ek)))) {
1011	>	oldVal = e.val;
1012	>	if (!onlyIfAbsent)
1013	>	e.val = value;
1014	>	break;
1015	>	}
1016	>	Node<K,V> pred = e;
1017	>	if ((e = e.next) == null) {
1018	>	pred.next = new Node<K,V>(hash, key, value);
1019	>	break;
1020	>	}
1021		}
351	–	break;
1022		}
1023	<	e = e.next;
1024	<	}
1025	<	else {
1026	<	if (node != null)
1027	<	node.setNext(first);
1028	<	else
1029	<	node = new HashEntry<K,V>(hash, key, value, first);
1030	<	int c = count + 1;
1031	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
1032	<	rehash(node);
1033	<	else
1034	<	setEntryAt(tab, index, node);
365	<	++modCount;
366	<	count = c;
367	<	oldValue = null;
368	<	break;
369	<	}
370	<	}
371	<	} finally {
372	<	unlock();
373	<	}
374	<	return oldValue;
375	<	}
376	<
377	<	/**
378	<	* Doubles size of table and repacks entries, also adding the
379	<	* given node to new table
380	<	*/
381	<	@SuppressWarnings("unchecked")
382	<	private void rehash(HashEntry<K,V> node) {
383	<	/*
384	<	* Reclassify nodes in each list to new table.  Because we
385	<	* are using power-of-two expansion, the elements from
386	<	* each bin must either stay at same index, or move with a
387	<	* power of two offset. We eliminate unnecessary node
388	<	* creation by catching cases where old nodes can be
389	<	* reused because their next fields won't change.
390	<	* Statistically, at the default threshold, only about
391	<	* one-sixth of them need cloning when a table
392	<	* doubles. The nodes they replace will be garbage
393	<	* collectable as soon as they are no longer referenced by
394	<	* any reader thread that may be in the midst of
395	<	* concurrently traversing table. Entry accesses use plain
396	<	* array indexing because they are followed by volatile
397	<	* table write.
398	<	*/
399	<	HashEntry<K,V>[] oldTable = table;
400	<	int oldCapacity = oldTable.length;
401	<	int newCapacity = oldCapacity << 1;
402	<	threshold = (int)(newCapacity * loadFactor);
403	<	HashEntry<K,V>[] newTable =
404	<	(HashEntry<K,V>[]) new HashEntry<?,?>[newCapacity];
405	<	int sizeMask = newCapacity - 1;
406	<	for (int i = 0; i < oldCapacity ; i++) {
407	<	HashEntry<K,V> e = oldTable[i];
408	<	if (e != null) {
409	<	HashEntry<K,V> next = e.next;
410	<	int idx = e.hash & sizeMask;
411	<	if (next == null)   //  Single node on list
412	<	newTable[idx] = e;
413	<	else { // Reuse consecutive sequence at same slot
414	<	HashEntry<K,V> lastRun = e;
415	<	int lastIdx = idx;
416	<	for (HashEntry<K,V> last = next;
417	<	last != null;
418	<	last = last.next) {
419	<	int k = last.hash & sizeMask;
420	<	if (k != lastIdx) {
421	<	lastIdx = k;
422	<	lastRun = last;
423	<	}
424	<	}
425	<	newTable[lastIdx] = lastRun;
426	<	// Clone remaining nodes
427	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
428	<	V v = p.value;
429	<	int h = p.hash;
430	<	int k = h & sizeMask;
431	<	HashEntry<K,V> n = newTable[k];
432	<	newTable[k] = new HashEntry<K,V>(h, p.key, v, n);
433	<	}
434	<	}
435	<	}
436	<	}
437	<	int nodeIndex = node.hash & sizeMask; // add the new node
438	<	node.setNext(newTable[nodeIndex]);
439	<	newTable[nodeIndex] = node;
440	<	table = newTable;
441	<	}
442	<
443	<	/**
444	<	* Scans for a node containing given key while trying to
445	<	* acquire lock, creating and returning one if not found. Upon
446	<	* return, guarantees that lock is held. Unlike in most
447	<	* methods, calls to method equals are not screened: Since
448	<	* traversal speed doesn't matter, we might as well help warm
449	<	* up the associated code and accesses as well.
450	<	*
451	<	* @return a new node if key not found, else null
452	<	*/
453	<	private HashEntry<K,V> scanAndLockForPut(K key, int hash, V value) {
454	<	HashEntry<K,V> first = entryForHash(this, hash);
455	<	HashEntry<K,V> e = first;
456	<	HashEntry<K,V> node = null;
457	<	int retries = -1; // negative while locating node
458	<	while (!tryLock()) {
459	<	HashEntry<K,V> f; // to recheck first below
460	<	if (retries < 0) {
461	<	if (e == null) {
462	<	if (node == null) // speculatively create node
463	<	node = new HashEntry<K,V>(hash, key, value, null);
464	<	retries = 0;
1023	>	else if (f instanceof TreeBin) {
1024	>	Node<K,V> p;
1025	>	binCount = 2;
1026	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1027	>	value)) != null) {
1028	>	oldVal = p.val;
1029	>	if (!onlyIfAbsent)
1030	>	p.val = value;
1031	>	}
1032	>	}
1033	>	else if (f instanceof ReservationNode)
1034	>	throw new IllegalStateException("Recursive update");
1035		}
466	–	else if (key.equals(e.key))
467	–	retries = 0;
468	–	else
469	–	e = e.next;
470	–	}
471	–	else if (++retries > MAX_SCAN_RETRIES) {
472	–	lock();
473	–	break;
474	–	}
475	–	else if ((retries & 1) == 0 &&
476	–	(f = entryForHash(this, hash)) != first) {
477	–	e = first = f; // re-traverse if entry changed
478	–	retries = -1;
479	–	}
480	–	}
481	–	return node;
482	–	}
483	–
484	–	/**
485	–	* Scans for a node containing the given key while trying to
486	–	* acquire lock for a remove or replace operation. Upon
487	–	* return, guarantees that lock is held.  Note that we must
488	–	* lock even if the key is not found, to ensure sequential
489	–	* consistency of updates.
490	–	*/
491	–	private void scanAndLock(Object key, int hash) {
492	–	// similar to but simpler than scanAndLockForPut
493	–	HashEntry<K,V> first = entryForHash(this, hash);
494	–	HashEntry<K,V> e = first;
495	–	int retries = -1;
496	–	while (!tryLock()) {
497	–	HashEntry<K,V> f;
498	–	if (retries < 0) {
499	–	if (e == null || key.equals(e.key))
500	–	retries = 0;
501	–	else
502	–	e = e.next;
1036		}
1037	<	else if (++retries > MAX_SCAN_RETRIES) {
1038	<	lock();
1037	>	if (binCount != 0) {
1038	>	if (binCount >= TREEIFY_THRESHOLD)
1039	>	treeifyBin(tab, i);
1040	>	if (oldVal != null)
1041	>	return oldVal;
1042		break;
1043		}
508	–	else if ((retries & 1) == 0 &&
509	–	(f = entryForHash(this, hash)) != first) {
510	–	e = first = f;
511	–	retries = -1;
512	–	}
1044		}
1045		}
1046	+	addCount(1L, binCount);
1047	+	return null;
1048	+	}
1049
1050	<	/**
1051	<	* Remove; match on key only if value null, else match both.
1052	<	*/
1053	<	final V remove(Object key, int hash, Object value) {
1054	<	if (!tryLock())
1055	<	scanAndLock(key, hash);
1056	<	V oldValue = null;
1057	<	try {
1058	<	HashEntry<K,V>[] tab = table;
1059	<	int index = (tab.length - 1) & hash;
1060	<	HashEntry<K,V> e = entryAt(tab, index);
1061	<	HashEntry<K,V> pred = null;
1062	<	while (e != null) {
1063	<	K k;
1064	<	HashEntry<K,V> next = e.next;
1065	<	if ((k = e.key) == key ||
1066	<	(e.hash == hash && key.equals(k))) {
1067	<	V v = e.value;
1068	<	if (value == null || value == v || value.equals(v)) {
1069	<	if (pred == null)
1070	<	setEntryAt(tab, index, next);
1071	<	else
1072	<	pred.setNext(next);
1073	<	++modCount;
1074	<	--count;
1075	<	oldValue = v;
1050	>	/**
1051	>	* Copies all of the mappings from the specified map to this one.
1052	>	* These mappings replace any mappings that this map had for any of the
1053	>	* keys currently in the specified map.
1054	>	*
1055	>	* @param m mappings to be stored in this map
1056	>	*/
1057	>	public void putAll(Map<? extends K, ? extends V> m) {
1058	>	tryPresize(m.size());
1059	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1060	>	putVal(e.getKey(), e.getValue(), false);
1061	>	}
1062	>
1063	>	/**
1064	>	* Removes the key (and its corresponding value) from this map.
1065	>	* This method does nothing if the key is not in the map.
1066	>	*
1067	>	* @param  key the key that needs to be removed
1068	>	* @return the previous value associated with {@code key}, or
1069	>	*         {@code null} if there was no mapping for {@code key}
1070	>	* @throws NullPointerException if the specified key is null
1071	>	*/
1072	>	public V remove(Object key) {
1073	>	return replaceNode(key, null, null);
1074	>	}
1075	>
1076	>	/**
1077	>	* Implementation for the four public remove/replace methods:
1078	>	* Replaces node value with v, conditional upon match of cv if
1079	>	* non-null.  If resulting value is null, delete.
1080	>	*/
1081	>	final V replaceNode(Object key, V value, Object cv) {
1082	>	int hash = spread(key.hashCode());
1083	>	for (Node<K,V>[] tab = table;;) {
1084	>	Node<K,V> f; int n, i, fh;
1085	>	if (tab == null || (n = tab.length) == 0 ||
1086	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1087	>	break;
1088	>	else if ((fh = f.hash) == MOVED)
1089	>	tab = helpTransfer(tab, f);
1090	>	else {
1091	>	V oldVal = null;
1092	>	boolean validated = false;
1093	>	synchronized (f) {
1094	>	if (tabAt(tab, i) == f) {
1095	>	if (fh >= 0) {
1096	>	validated = true;
1097	>	for (Node<K,V> e = f, pred = null;;) {
1098	>	K ek;
1099	>	if (e.hash == hash &&
1100	>	((ek = e.key) == key ||
1101	>	(ek != null && key.equals(ek)))) {
1102	>	V ev = e.val;
1103	>	if (cv == null || cv == ev ||
1104	>	(ev != null && cv.equals(ev))) {
1105	>	oldVal = ev;
1106	>	if (value != null)
1107	>	e.val = value;
1108	>	else if (pred != null)
1109	>	pred.next = e.next;
1110	>	else
1111	>	setTabAt(tab, i, e.next);
1112	>	}
1113	>	break;
1114	>	}
1115	>	pred = e;
1116	>	if ((e = e.next) == null)
1117	>	break;
1118	>	}
1119		}
1120	<	break;
1120	>	else if (f instanceof TreeBin) {
1121	>	validated = true;
1122	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1123	>	TreeNode<K,V> r, p;
1124	>	if ((r = t.root) != null &&
1125	>	(p = r.findTreeNode(hash, key, null)) != null) {
1126	>	V pv = p.val;
1127	>	if (cv == null || cv == pv ||
1128	>	(pv != null && cv.equals(pv))) {
1129	>	oldVal = pv;
1130	>	if (value != null)
1131	>	p.val = value;
1132	>	else if (t.removeTreeNode(p))
1133	>	setTabAt(tab, i, untreeify(t.first));
1134	>	}
1135	>	}
1136	>	}
1137	>	else if (f instanceof ReservationNode)
1138	>	throw new IllegalStateException("Recursive update");
1139		}
545	–	pred = e;
546	–	e = next;
1140		}
1141	<	} finally {
1142	<	unlock();
1143	<	}
1144	<	return oldValue;
1145	<	}
553	<
554	<	final boolean replace(K key, int hash, V oldValue, V newValue) {
555	<	if (!tryLock())
556	<	scanAndLock(key, hash);
557	<	boolean replaced = false;
558	<	try {
559	<	HashEntry<K,V> e;
560	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
561	<	K k;
562	<	if ((k = e.key) == key ||
563	<	(e.hash == hash && key.equals(k))) {
564	<	if (oldValue.equals(e.value)) {
565	<	e.value = newValue;
566	<	++modCount;
567	<	replaced = true;
568	<	}
569	<	break;
1141	>	if (validated) {
1142	>	if (oldVal != null) {
1143	>	if (value == null)
1144	>	addCount(-1L, -1);
1145	>	return oldVal;
1146		}
1147	+	break;
1148		}
572	–	} finally {
573	–	unlock();
1149		}
575	–	return replaced;
1150		}
1151	+	return null;
1152	+	}
1153
1154	<	final V replace(K key, int hash, V value) {
1155	<	if (!tryLock())
1156	<	scanAndLock(key, hash);
1157	<	V oldValue = null;
1158	<	try {
1159	<	HashEntry<K,V> e;
1160	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1161	<	K k;
1162	<	if ((k = e.key) == key ||
1163	<	(e.hash == hash && key.equals(k))) {
1164	<	oldValue = e.value;
1165	<	e.value = value;
1166	<	++modCount;
1167	<	break;
1154	>	/**
1155	>	* Removes all of the mappings from this map.
1156	>	*/
1157	>	public void clear() {
1158	>	long delta = 0L; // negative number of deletions
1159	>	int i = 0;
1160	>	Node<K,V>[] tab = table;
1161	>	while (tab != null && i < tab.length) {
1162	>	int fh;
1163	>	Node<K,V> f = tabAt(tab, i);
1164	>	if (f == null)
1165	>	++i;
1166	>	else if ((fh = f.hash) == MOVED) {
1167	>	tab = helpTransfer(tab, f);
1168	>	i = 0; // restart
1169	>	}
1170	>	else {
1171	>	synchronized (f) {
1172	>	if (tabAt(tab, i) == f) {
1173	>	Node<K,V> p = (fh >= 0 ? f :
1174	>	(f instanceof TreeBin) ?
1175	>	((TreeBin<K,V>)f).first : null);
1176	>	while (p != null) {
1177	>	--delta;
1178	>	p = p.next;
1179	>	}
1180	>	setTabAt(tab, i++, null);
1181		}
1182		}
594	–	} finally {
595	–	unlock();
1183		}
597	–	return oldValue;
1184		}
1185	+	if (delta != 0L)
1186	+	addCount(delta, -1);
1187	+	}
1188
1189	<	final void clear() {
1190	<	lock();
1191	<	try {
1192	<	HashEntry<K,V>[] tab = table;
1193	<	for (int i = 0; i < tab.length ; i++)
1194	<	setEntryAt(tab, i, null);
1195	<	++modCount;
1196	<	count = 0;
1197	<	} finally {
1198	<	unlock();
1199	<	}
1200	<	}
1189	>	/**
1190	>	* Returns a {@link Set} view of the keys contained in this map.
1191	>	* The set is backed by the map, so changes to the map are
1192	>	* reflected in the set, and vice-versa. The set supports element
1193	>	* removal, which removes the corresponding mapping from this map,
1194	>	* via the {@code Iterator.remove}, {@code Set.remove},
1195	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1196	>	* operations.  It does not support the {@code add} or
1197	>	* {@code addAll} operations.
1198	>	*
1199	>	* <p>The view's iterators and spliterators are
1200	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1201	>	*
1202	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1203	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1204	>	*
1205	>	* @return the set view
1206	>	*/
1207	>	public KeySetView<K,V> keySet() {
1208	>	KeySetView<K,V> ks;
1209	>	if ((ks = keySet) != null) return ks;
1210	>	return keySet = new KeySetView<K,V>(this, null);
1211		}
1212
1213	<	// Accessing segments
1213	>	/**
1214	>	* Returns a {@link Collection} view of the values contained in this map.
1215	>	* The collection is backed by the map, so changes to the map are
1216	>	* reflected in the collection, and vice-versa.  The collection
1217	>	* supports element removal, which removes the corresponding
1218	>	* mapping from this map, via the {@code Iterator.remove},
1219	>	* {@code Collection.remove}, {@code removeAll},
1220	>	* {@code retainAll}, and {@code clear} operations.  It does not
1221	>	* support the {@code add} or {@code addAll} operations.
1222	>	*
1223	>	* <p>The view's iterators and spliterators are
1224	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1225	>	*
1226	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1227	>	* and {@link Spliterator#NONNULL}.
1228	>	*
1229	>	* @return the collection view
1230	>	*/
1231	>	public Collection<V> values() {
1232	>	ValuesView<K,V> vs;
1233	>	if ((vs = values) != null) return vs;
1234	>	return values = new ValuesView<K,V>(this);
1235	>	}
1236
1237		/**
1238	<	* Gets the jth element of given segment array (if nonnull) with
1239	<	* volatile element access semantics via Unsafe. (The null check
1240	<	* can trigger harmlessly only during deserialization.) Note:
1241	<	* because each element of segments array is set only once (using
1242	<	* fully ordered writes), some performance-sensitive methods rely
1243	<	* on this method only as a recheck upon null reads.
1238	>	* Returns a {@link Set} view of the mappings contained in this map.
1239	>	* The set is backed by the map, so changes to the map are
1240	>	* reflected in the set, and vice-versa.  The set supports element
1241	>	* removal, which removes the corresponding mapping from the map,
1242	>	* via the {@code Iterator.remove}, {@code Set.remove},
1243	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1244	>	* operations.
1245	>	*
1246	>	* <p>The view's iterators and spliterators are
1247	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1248	>	*
1249	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1250	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1251	>	*
1252	>	* @return the set view
1253		*/
1254	<	@SuppressWarnings("unchecked")
1255	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1256	<	long u = (j << SSHIFT) + SBASE;
1257	<	return ss == null ? null :
628	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1254	>	public Set<Map.Entry<K,V>> entrySet() {
1255	>	EntrySetView<K,V> es;
1256	>	if ((es = entrySet) != null) return es;
1257	>	return entrySet = new EntrySetView<K,V>(this);
1258		}
1259
1260		/**
1261	<	* Returns the segment for the given index, creating it and
1262	<	* recording in segment table (via CAS) if not already present.
1261	>	* Returns the hash code value for this {@link Map}, i.e.,
1262	>	* the sum of, for each key-value pair in the map,
1263	>	* {@code key.hashCode() ^ value.hashCode()}.
1264		*
1265	<	* @param k the index
636	<	* @return the segment
1265	>	* @return the hash code value for this map
1266		*/
1267	<	@SuppressWarnings("unchecked")
1268	<	private Segment<K,V> ensureSegment(int k) {
1269	<	final Segment<K,V>[] ss = this.segments;
1270	<	long u = (k << SSHIFT) + SBASE; // raw offset
1271	<	Segment<K,V> seg;
1272	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1273	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1274	<	int cap = proto.table.length;
1275	<	float lf = proto.loadFactor;
1276	<	int threshold = (int)(cap * lf);
1277	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry<?,?>[cap];
1278	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1279	<	== null) { // recheck
1280	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1281	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1282	<	== null) {
1283	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1284	<	break;
1285	<	}
1267	>	public int hashCode() {
1268	>	int h = 0;
1269	>	Node<K,V>[] t;
1270	>	if ((t = table) != null) {
1271	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1272	>	for (Node<K,V> p; (p = it.advance()) != null; )
1273	>	h += p.key.hashCode() ^ p.val.hashCode();
1274	>	}
1275	>	return h;
1276	>	}
1277	>
1278	>	/**
1279	>	* Returns a string representation of this map.  The string
1280	>	* representation consists of a list of key-value mappings (in no
1281	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1282	>	* mappings are separated by the characters {@code ", "} (comma
1283	>	* and space).  Each key-value mapping is rendered as the key
1284	>	* followed by an equals sign ("{@code =}") followed by the
1285	>	* associated value.
1286	>	*
1287	>	* @return a string representation of this map
1288	>	*/
1289	>	public String toString() {
1290	>	Node<K,V>[] t;
1291	>	int f = (t = table) == null ? 0 : t.length;
1292	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1293	>	StringBuilder sb = new StringBuilder();
1294	>	sb.append('{');
1295	>	Node<K,V> p;
1296	>	if ((p = it.advance()) != null) {
1297	>	for (;;) {
1298	>	K k = p.key;
1299	>	V v = p.val;
1300	>	sb.append(k == this ? "(this Map)" : k);
1301	>	sb.append('=');
1302	>	sb.append(v == this ? "(this Map)" : v);
1303	>	if ((p = it.advance()) == null)
1304	>	break;
1305	>	sb.append(',').append(' ');
1306		}
1307		}
1308	<	return seg;
1308	>	return sb.append('}').toString();
1309		}
1310
662	–	// Hash-based segment and entry accesses
663	–
1311		/**
1312	<	* Gets the segment for the given hash code.
1312	>	* Compares the specified object with this map for equality.
1313	>	* Returns {@code true} if the given object is a map with the same
1314	>	* mappings as this map.  This operation may return misleading
1315	>	* results if either map is concurrently modified during execution
1316	>	* of this method.
1317	>	*
1318	>	* @param o object to be compared for equality with this map
1319	>	* @return {@code true} if the specified object is equal to this map
1320		*/
1321	<	@SuppressWarnings("unchecked")
1322	<	private Segment<K,V> segmentForHash(int h) {
1323	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1324	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1321	>	public boolean equals(Object o) {
1322	>	if (o != this) {
1323	>	if (!(o instanceof Map))
1324	>	return false;
1325	>	Map<?,?> m = (Map<?,?>) o;
1326	>	Node<K,V>[] t;
1327	>	int f = (t = table) == null ? 0 : t.length;
1328	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1329	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1330	>	V val = p.val;
1331	>	Object v = m.get(p.key);
1332	>	if (v == null || (v != val && !v.equals(val)))
1333	>	return false;
1334	>	}
1335	>	for (Map.Entry<?,?> e : m.entrySet()) {
1336	>	Object mk, mv, v;
1337	>	if ((mk = e.getKey()) == null ||
1338	>	(mv = e.getValue()) == null ||
1339	>	(v = get(mk)) == null ||
1340	>	(mv != v && !mv.equals(v)))
1341	>	return false;
1342	>	}
1343	>	}
1344	>	return true;
1345		}
1346
1347		/**
1348	<	* Gets the table entry for the given segment and hash code.
1348	>	* Stripped-down version of helper class used in previous version,
1349	>	* declared for the sake of serialization compatibility.
1350		*/
1351	<	@SuppressWarnings("unchecked")
1352	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1353	<	HashEntry<K,V>[] tab;
1354	<	return (seg == null || (tab = seg.table) == null) ? null :
680	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
681	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1351	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1352	>	private static final long serialVersionUID = 2249069246763182397L;
1353	>	final float loadFactor;
1354	>	Segment(float lf) { this.loadFactor = lf; }
1355		}
1356
684	–	/* ---------------- Public operations -------------- */
685	–
1357		/**
1358	<	* Creates a new, empty map with the specified initial
688	<	* capacity, load factor and concurrency level.
1358	>	* Saves this map to a stream (that is, serializes it).
1359		*
1360	<	* @param initialCapacity the initial capacity. The implementation
1361	<	* performs internal sizing to accommodate this many elements.
1362	<	* @param loadFactor  the load factor threshold, used to control resizing.
1363	<	* Resizing may be performed when the average number of elements per
1364	<	* bin exceeds this threshold.
1365	<	* @param concurrencyLevel the estimated number of concurrently
696	<	* updating threads. The implementation performs internal sizing
697	<	* to try to accommodate this many threads.
698	<	* @throws IllegalArgumentException if the initial capacity is
699	<	* negative or the load factor or concurrencyLevel are
700	<	* nonpositive.
1360	>	* @param s the stream
1361	>	* @throws java.io.IOException if an I/O error occurs
1362	>	* @serialData
1363	>	* the serialized fields, followed by the key (Object) and value
1364	>	* (Object) for each key-value mapping, followed by a null pair.
1365	>	* The key-value mappings are emitted in no particular order.
1366		*/
1367	<	@SuppressWarnings("unchecked")
1368	<	public ConcurrentHashMap(int initialCapacity,
1369	<	float loadFactor, int concurrencyLevel) {
1370	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
706	<	throw new IllegalArgumentException();
707	<	if (concurrencyLevel > MAX_SEGMENTS)
708	<	concurrencyLevel = MAX_SEGMENTS;
709	<	// Find power-of-two sizes best matching arguments
1367	>	private void writeObject(java.io.ObjectOutputStream s)
1368	>	throws java.io.IOException {
1369	>	// For serialization compatibility
1370	>	// Emulate segment calculation from previous version of this class
1371		int sshift = 0;
1372		int ssize = 1;
1373	<	while (ssize < concurrencyLevel) {
1373	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1374		++sshift;
1375		ssize <<= 1;
1376		}
1377	<	this.segmentShift = 32 - sshift;
1378	<	this.segmentMask = ssize - 1;
1379	<	if (initialCapacity > MAXIMUM_CAPACITY)
1380	<	initialCapacity = MAXIMUM_CAPACITY;
1381	<	int c = initialCapacity / ssize;
1382	<	if (c * ssize < initialCapacity)
1383	<	++c;
1384	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1385	<	while (cap < c)
1386	<	cap <<= 1;
1387	<	// create segments and segments[0]
1388	<	Segment<K,V> s0 =
1389	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1390	<	(HashEntry<K,V>[])new HashEntry<?,?>[cap]);
1391	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment<?,?>[ssize];
1392	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1393	<	this.segments = ss;
1377	>	int segmentShift = 32 - sshift;
1378	>	int segmentMask = ssize - 1;
1379	>	@SuppressWarnings("unchecked")
1380	>	Segment<K,V>[] segments = (Segment<K,V>[])
1381	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1382	>	for (int i = 0; i < segments.length; ++i)
1383	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1384	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1385	>	streamFields.put("segments", segments);
1386	>	streamFields.put("segmentShift", segmentShift);
1387	>	streamFields.put("segmentMask", segmentMask);
1388	>	s.writeFields();
1389	>
1390	>	Node<K,V>[] t;
1391	>	if ((t = table) != null) {
1392	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1393	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1394	>	s.writeObject(p.key);
1395	>	s.writeObject(p.val);
1396	>	}
1397	>	}
1398	>	s.writeObject(null);
1399	>	s.writeObject(null);
1400		}
1401
1402		/**
1403	<	* Creates a new, empty map with the specified initial capacity
1404	<	* and load factor and with the default concurrencyLevel (16).
1405	<	*
1406	<	* @param initialCapacity The implementation performs internal
1407	<	* sizing to accommodate this many elements.
1408	<	* @param loadFactor  the load factor threshold, used to control resizing.
1409	<	* Resizing may be performed when the average number of elements per
1410	<	* bin exceeds this threshold.
1411	<	* @throws IllegalArgumentException if the initial capacity of
1412	<	* elements is negative or the load factor is nonpositive
1403	>	* Reconstitutes this map from a stream (that is, deserializes it).
1404	>	* @param s the stream
1405	>	* @throws ClassNotFoundException if the class of a serialized object
1406	>	*         could not be found
1407	>	* @throws java.io.IOException if an I/O error occurs
1408	>	*/
1409	>	private void readObject(java.io.ObjectInputStream s)
1410	>	throws java.io.IOException, ClassNotFoundException {
1411	>	/*
1412	>	* To improve performance in typical cases, we create nodes
1413	>	* while reading, then place in table once size is known.
1414	>	* However, we must also validate uniqueness and deal with
1415	>	* overpopulated bins while doing so, which requires
1416	>	* specialized versions of putVal mechanics.
1417	>	*/
1418	>	sizeCtl = -1; // force exclusion for table construction
1419	>	s.defaultReadObject();
1420	>	long size = 0L;
1421	>	Node<K,V> p = null;
1422	>	for (;;) {
1423	>	@SuppressWarnings("unchecked")
1424	>	K k = (K) s.readObject();
1425	>	@SuppressWarnings("unchecked")
1426	>	V v = (V) s.readObject();
1427	>	if (k != null && v != null) {
1428	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1429	>	++size;
1430	>	}
1431	>	else
1432	>	break;
1433	>	}
1434	>	if (size == 0L)
1435	>	sizeCtl = 0;
1436	>	else {
1437	>	long ts = (long)(1.0 + size / LOAD_FACTOR);
1438	>	int n = (ts >= (long)MAXIMUM_CAPACITY) ?
1439	>	MAXIMUM_CAPACITY : tableSizeFor((int)ts);
1440	>	@SuppressWarnings("unchecked")
1441	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1442	>	int mask = n - 1;
1443	>	long added = 0L;
1444	>	while (p != null) {
1445	>	boolean insertAtFront;
1446	>	Node<K,V> next = p.next, first;
1447	>	int h = p.hash, j = h & mask;
1448	>	if ((first = tabAt(tab, j)) == null)
1449	>	insertAtFront = true;
1450	>	else {
1451	>	K k = p.key;
1452	>	if (first.hash < 0) {
1453	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1454	>	if (t.putTreeVal(h, k, p.val) == null)
1455	>	++added;
1456	>	insertAtFront = false;
1457	>	}
1458	>	else {
1459	>	int binCount = 0;
1460	>	insertAtFront = true;
1461	>	Node<K,V> q; K qk;
1462	>	for (q = first; q != null; q = q.next) {
1463	>	if (q.hash == h &&
1464	>	((qk = q.key) == k ||
1465	>	(qk != null && k.equals(qk)))) {
1466	>	insertAtFront = false;
1467	>	break;
1468	>	}
1469	>	++binCount;
1470	>	}
1471	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1472	>	insertAtFront = false;
1473	>	++added;
1474	>	p.next = first;
1475	>	TreeNode<K,V> hd = null, tl = null;
1476	>	for (q = p; q != null; q = q.next) {
1477	>	TreeNode<K,V> t = new TreeNode<K,V>
1478	>	(q.hash, q.key, q.val, null, null);
1479	>	if ((t.prev = tl) == null)
1480	>	hd = t;
1481	>	else
1482	>	tl.next = t;
1483	>	tl = t;
1484	>	}
1485	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1486	>	}
1487	>	}
1488	>	}
1489	>	if (insertAtFront) {
1490	>	++added;
1491	>	p.next = first;
1492	>	setTabAt(tab, j, p);
1493	>	}
1494	>	p = next;
1495	>	}
1496	>	table = tab;
1497	>	sizeCtl = n - (n >>> 2);
1498	>	baseCount = added;
1499	>	}
1500	>	}
1501	>
1502	>	// ConcurrentMap methods
1503	>
1504	>	/**
1505	>	* {@inheritDoc}
1506		*
1507	<	* @since 1.6
1507	>	* @return the previous value associated with the specified key,
1508	>	*         or {@code null} if there was no mapping for the key
1509	>	* @throws NullPointerException if the specified key or value is null
1510		*/
1511	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
1512	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1511	>	public V putIfAbsent(K key, V value) {
1512	>	return putVal(key, value, true);
1513		}
1514
1515		/**
1516	<	* Creates a new, empty map with the specified initial capacity,
755	<	* and with default load factor (0.75) and concurrencyLevel (16).
1516	>	* {@inheritDoc}
1517		*
1518	<	* @param initialCapacity the initial capacity. The implementation
758	<	* performs internal sizing to accommodate this many elements.
759	<	* @throws IllegalArgumentException if the initial capacity of
760	<	* elements is negative.
1518	>	* @throws NullPointerException if the specified key is null
1519		*/
1520	<	public ConcurrentHashMap(int initialCapacity) {
1521	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1520	>	public boolean remove(Object key, Object value) {
1521	>	if (key == null)
1522	>	throw new NullPointerException();
1523	>	return value != null && replaceNode(key, null, value) != null;
1524		}
1525
1526		/**
1527	<	* Creates a new, empty map with a default initial capacity (16),
1528	<	* load factor (0.75) and concurrencyLevel (16).
1527	>	* {@inheritDoc}
1528	>	*
1529	>	* @throws NullPointerException if any of the arguments are null
1530		*/
1531	<	public ConcurrentHashMap() {
1532	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1531	>	public boolean replace(K key, V oldValue, V newValue) {
1532	>	if (key == null || oldValue == null || newValue == null)
1533	>	throw new NullPointerException();
1534	>	return replaceNode(key, newValue, oldValue) != null;
1535		}
1536
1537		/**
1538	<	* Creates a new map with the same mappings as the given map.
776	<	* The map is created with a capacity of 1.5 times the number
777	<	* of mappings in the given map or 16 (whichever is greater),
778	<	* and a default load factor (0.75) and concurrencyLevel (16).
1538	>	* {@inheritDoc}
1539		*
1540	<	* @param m the map
1540	>	* @return the previous value associated with the specified key,
1541	>	*         or {@code null} if there was no mapping for the key
1542	>	* @throws NullPointerException if the specified key or value is null
1543		*/
1544	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1545	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1546	<	DEFAULT_INITIAL_CAPACITY),
1547	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
786	<	putAll(m);
1544	>	public V replace(K key, V value) {
1545	>	if (key == null || value == null)
1546	>	throw new NullPointerException();
1547	>	return replaceNode(key, value, null);
1548		}
1549
1550	+	// Overrides of JDK8+ Map extension method defaults
1551	+
1552		/**
1553	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1553	>	* Returns the value to which the specified key is mapped, or the
1554	>	* given default value if this map contains no mapping for the
1555	>	* key.
1556		*
1557	<	* @return <tt>true</tt> if this map contains no key-value mappings
1557	>	* @param key the key whose associated value is to be returned
1558	>	* @param defaultValue the value to return if this map contains
1559	>	* no mapping for the given key
1560	>	* @return the mapping for the key, if present; else the default value
1561	>	* @throws NullPointerException if the specified key is null
1562		*/
1563	<	public boolean isEmpty() {
1564	<	/*
1565	<	* Sum per-segment modCounts to avoid mis-reporting when
1566	<	* elements are concurrently added and removed in one segment
1567	<	* while checking another, in which case the table was never
1568	<	* actually empty at any point. (The sum ensures accuracy up
1569	<	* through at least 1<<31 per-segment modifications before
1570	<	* recheck.)  Methods size() and containsValue() use similar
1571	<	* constructions for stability checks.
1572	<	*/
1573	<	long sum = 0L;
1574	<	final Segment<K,V>[] segments = this.segments;
806	<	for (int j = 0; j < segments.length; ++j) {
807	<	Segment<K,V> seg = segmentAt(segments, j);
808	<	if (seg != null) {
809	<	if (seg.count != 0)
810	<	return false;
811	<	sum += seg.modCount;
1563	>	public V getOrDefault(Object key, V defaultValue) {
1564	>	V v;
1565	>	return (v = get(key)) == null ? defaultValue : v;
1566	>	}
1567	>
1568	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1569	>	if (action == null) throw new NullPointerException();
1570	>	Node<K,V>[] t;
1571	>	if ((t = table) != null) {
1572	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1573	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1574	>	action.accept(p.key, p.val);
1575		}
1576		}
1577	<	if (sum != 0L) { // recheck unless no modifications
1578	<	for (int j = 0; j < segments.length; ++j) {
1579	<	Segment<K,V> seg = segmentAt(segments, j);
1580	<	if (seg != null) {
1581	<	if (seg.count != 0)
1582	<	return false;
1583	<	sum -= seg.modCount;
1577	>	}
1578	>
1579	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1580	>	if (function == null) throw new NullPointerException();
1581	>	Node<K,V>[] t;
1582	>	if ((t = table) != null) {
1583	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1584	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1585	>	V oldValue = p.val;
1586	>	for (K key = p.key;;) {
1587	>	V newValue = function.apply(key, oldValue);
1588	>	if (newValue == null)
1589	>	throw new NullPointerException();
1590	>	if (replaceNode(key, newValue, oldValue) != null ||
1591	>	(oldValue = get(key)) == null)
1592	>	break;
1593		}
1594		}
823	–	if (sum != 0L)
824	–	return false;
1595		}
826	–	return true;
1596		}
1597
1598		/**
1599	<	* Returns the number of key-value mappings in this map.  If the
831	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
832	<	* <tt>Integer.MAX_VALUE</tt>.
833	<	*
834	<	* @return the number of key-value mappings in this map
1599	>	* Helper method for EntrySetView.removeIf.
1600		*/
1601	<	public int size() {
1602	<	// Try a few times to get accurate count. On failure due to
1603	<	// continuous async changes in table, resort to locking.
1604	<	final Segment<K,V>[] segments = this.segments;
1605	<	final int segmentCount = segments.length;
1606	<
1607	<	long previousSum = 0L;
1608	<	for (int retries = -1; retries < RETRIES_BEFORE_LOCK; retries++) {
1609	<	long sum = 0L;    // sum of modCounts
1610	<	long size = 0L;
1611	<	for (int i = 0; i < segmentCount; i++) {
1612	<	Segment<K,V> segment = segmentAt(segments, i);
1613	<	if (segment != null) {
849	<	sum += segment.modCount;
850	<	size += segment.count;
851	<	}
852	<	}
853	<	if (sum == previousSum)
854	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
855	<	previousSum = sum;
1601	>	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1602	>	if (function == null) throw new NullPointerException();
1603	>	Node<K,V>[] t;
1604	>	boolean removed = false;
1605	>	if ((t = table) != null) {
1606	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1607	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1608	>	K k = p.key;
1609	>	V v = p.val;
1610	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1611	>	if (function.test(e) && replaceNode(k, null, v) != null)
1612	>	removed = true;
1613	>	}
1614		}
1615	+	return removed;
1616	+	}
1617
1618	<	long size = 0L;
1619	<	for (int i = 0; i < segmentCount; i++) {
1620	<	Segment<K,V> segment = ensureSegment(i);
1621	<	segment.lock();
1622	<	size += segment.count;
1623	<	}
1624	<	for (int i = 0; i < segmentCount; i++)
1625	<	segments[i].unlock();
1626	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1618	>	/**
1619	>	* Helper method for ValuesView.removeIf.
1620	>	*/
1621	>	boolean removeValueIf(Predicate<? super V> function) {
1622	>	if (function == null) throw new NullPointerException();
1623	>	Node<K,V>[] t;
1624	>	boolean removed = false;
1625	>	if ((t = table) != null) {
1626	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1627	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1628	>	K k = p.key;
1629	>	V v = p.val;
1630	>	if (function.test(v) && replaceNode(k, null, v) != null)
1631	>	removed = true;
1632	>	}
1633	>	}
1634	>	return removed;
1635		}
1636
1637		/**
1638	<	* Returns the value to which the specified key is mapped,
1639	<	* or {@code null} if this map contains no mapping for the key.
1638	>	* If the specified key is not already associated with a value,
1639	>	* attempts to compute its value using the given mapping function
1640	>	* and enters it into this map unless {@code null}.  The entire
1641	>	* method invocation is performed atomically, so the function is
1642	>	* applied at most once per key.  Some attempted update operations
1643	>	* on this map by other threads may be blocked while computation
1644	>	* is in progress, so the computation should be short and simple,
1645	>	* and must not attempt to update any other mappings of this map.
1646		*
1647	<	* <p>More formally, if this map contains a mapping from a key
1648	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1649	<	* then this method returns {@code v}; otherwise it returns
1650	<	* {@code null}.  (There can be at most one such mapping.)
1651	<	*
1652	<	* @throws NullPointerException if the specified key is null
1647	>	* @param key key with which the specified value is to be associated
1648	>	* @param mappingFunction the function to compute a value
1649	>	* @return the current (existing or computed) value associated with
1650	>	*         the specified key, or null if the computed value is null
1651	>	* @throws NullPointerException if the specified key or mappingFunction
1652	>	*         is null
1653	>	* @throws IllegalStateException if the computation detectably
1654	>	*         attempts a recursive update to this map that would
1655	>	*         otherwise never complete
1656	>	* @throws RuntimeException or Error if the mappingFunction does so,
1657	>	*         in which case the mapping is left unestablished
1658		*/
1659	<	@SuppressWarnings("unchecked")
1660	<	public V get(Object key) {
1661	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1662	<	HashEntry<K,V>[] tab;
1663	<	int h = hash(key.hashCode());
1664	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1665	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1666	<	(tab = s.table) != null) {
1667	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1668	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1669	<	e != null; e = e.next) {
1670	<	K k;
1671	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1672	<	return e.value;
1659	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1660	>	if (key == null || mappingFunction == null)
1661	>	throw new NullPointerException();
1662	>	int h = spread(key.hashCode());
1663	>	V val = null;
1664	>	int binCount = 0;
1665	>	for (Node<K,V>[] tab = table;;) {
1666	>	Node<K,V> f; int n, i, fh; K fk; V fv;
1667	>	if (tab == null || (n = tab.length) == 0)
1668	>	tab = initTable();
1669	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1670	>	Node<K,V> r = new ReservationNode<K,V>();
1671	>	synchronized (r) {
1672	>	if (casTabAt(tab, i, null, r)) {
1673	>	binCount = 1;
1674	>	Node<K,V> node = null;
1675	>	try {
1676	>	if ((val = mappingFunction.apply(key)) != null)
1677	>	node = new Node<K,V>(h, key, val);
1678	>	} finally {
1679	>	setTabAt(tab, i, node);
1680	>	}
1681	>	}
1682	>	}
1683	>	if (binCount != 0)
1684	>	break;
1685	>	}
1686	>	else if ((fh = f.hash) == MOVED)
1687	>	tab = helpTransfer(tab, f);
1688	>	else if (fh == h    // check first node without acquiring lock
1689	>	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1690	>	&& (fv = f.val) != null)
1691	>	return fv;
1692	>	else {
1693	>	boolean added = false;
1694	>	synchronized (f) {
1695	>	if (tabAt(tab, i) == f) {
1696	>	if (fh >= 0) {
1697	>	binCount = 1;
1698	>	for (Node<K,V> e = f;; ++binCount) {
1699	>	K ek;
1700	>	if (e.hash == h &&
1701	>	((ek = e.key) == key ||
1702	>	(ek != null && key.equals(ek)))) {
1703	>	val = e.val;
1704	>	break;
1705	>	}
1706	>	Node<K,V> pred = e;
1707	>	if ((e = e.next) == null) {
1708	>	if ((val = mappingFunction.apply(key)) != null) {
1709	>	if (pred.next != null)
1710	>	throw new IllegalStateException("Recursive update");
1711	>	added = true;
1712	>	pred.next = new Node<K,V>(h, key, val);
1713	>	}
1714	>	break;
1715	>	}
1716	>	}
1717	>	}
1718	>	else if (f instanceof TreeBin) {
1719	>	binCount = 2;
1720	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1721	>	TreeNode<K,V> r, p;
1722	>	if ((r = t.root) != null &&
1723	>	(p = r.findTreeNode(h, key, null)) != null)
1724	>	val = p.val;
1725	>	else if ((val = mappingFunction.apply(key)) != null) {
1726	>	added = true;
1727	>	t.putTreeVal(h, key, val);
1728	>	}
1729	>	}
1730	>	else if (f instanceof ReservationNode)
1731	>	throw new IllegalStateException("Recursive update");
1732	>	}
1733	>	}
1734	>	if (binCount != 0) {
1735	>	if (binCount >= TREEIFY_THRESHOLD)
1736	>	treeifyBin(tab, i);
1737	>	if (!added)
1738	>	return val;
1739	>	break;
1740	>	}
1741		}
1742		}
1743	<	return null;
1743	>	if (val != null)
1744	>	addCount(1L, binCount);
1745	>	return val;
1746		}
1747
1748		/**
1749	<	* Tests if the specified object is a key in this table.
1749	>	* If the value for the specified key is present, attempts to
1750	>	* compute a new mapping given the key and its current mapped
1751	>	* value.  The entire method invocation is performed atomically.
1752	>	* Some attempted update operations on this map by other threads
1753	>	* may be blocked while computation is in progress, so the
1754	>	* computation should be short and simple, and must not attempt to
1755	>	* update any other mappings of this map.
1756		*
1757	<	* @param  key   possible key
1758	<	* @return <tt>true</tt> if and only if the specified object
1759	<	*         is a key in this table, as determined by the
1760	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1761	<	* @throws NullPointerException if the specified key is null
1757	>	* @param key key with which a value may be associated
1758	>	* @param remappingFunction the function to compute a value
1759	>	* @return the new value associated with the specified key, or null if none
1760	>	* @throws NullPointerException if the specified key or remappingFunction
1761	>	*         is null
1762	>	* @throws IllegalStateException if the computation detectably
1763	>	*         attempts a recursive update to this map that would
1764	>	*         otherwise never complete
1765	>	* @throws RuntimeException or Error if the remappingFunction does so,
1766	>	*         in which case the mapping is unchanged
1767		*/
1768	<	@SuppressWarnings("unchecked")
1769	<	public boolean containsKey(Object key) {
1770	<	Segment<K,V> s; // same as get() except no need for volatile value read
1771	<	HashEntry<K,V>[] tab;
1772	<	int h = hash(key.hashCode());
1773	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1774	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1775	<	(tab = s.table) != null) {
1776	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1777	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1778	<	e != null; e = e.next) {
1779	<	K k;
1780	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1781	<	return true;
1768	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1769	>	if (key == null || remappingFunction == null)
1770	>	throw new NullPointerException();
1771	>	int h = spread(key.hashCode());
1772	>	V val = null;
1773	>	int delta = 0;
1774	>	int binCount = 0;
1775	>	for (Node<K,V>[] tab = table;;) {
1776	>	Node<K,V> f; int n, i, fh;
1777	>	if (tab == null || (n = tab.length) == 0)
1778	>	tab = initTable();
1779	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1780	>	break;
1781	>	else if ((fh = f.hash) == MOVED)
1782	>	tab = helpTransfer(tab, f);
1783	>	else {
1784	>	synchronized (f) {
1785	>	if (tabAt(tab, i) == f) {
1786	>	if (fh >= 0) {
1787	>	binCount = 1;
1788	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1789	>	K ek;
1790	>	if (e.hash == h &&
1791	>	((ek = e.key) == key ||
1792	>	(ek != null && key.equals(ek)))) {
1793	>	val = remappingFunction.apply(key, e.val);
1794	>	if (val != null)
1795	>	e.val = val;
1796	>	else {
1797	>	delta = -1;
1798	>	Node<K,V> en = e.next;
1799	>	if (pred != null)
1800	>	pred.next = en;
1801	>	else
1802	>	setTabAt(tab, i, en);
1803	>	}
1804	>	break;
1805	>	}
1806	>	pred = e;
1807	>	if ((e = e.next) == null)
1808	>	break;
1809	>	}
1810	>	}
1811	>	else if (f instanceof TreeBin) {
1812	>	binCount = 2;
1813	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1814	>	TreeNode<K,V> r, p;
1815	>	if ((r = t.root) != null &&
1816	>	(p = r.findTreeNode(h, key, null)) != null) {
1817	>	val = remappingFunction.apply(key, p.val);
1818	>	if (val != null)
1819	>	p.val = val;
1820	>	else {
1821	>	delta = -1;
1822	>	if (t.removeTreeNode(p))
1823	>	setTabAt(tab, i, untreeify(t.first));
1824	>	}
1825	>	}
1826	>	}
1827	>	else if (f instanceof ReservationNode)
1828	>	throw new IllegalStateException("Recursive update");
1829	>	}
1830	>	}
1831	>	if (binCount != 0)
1832	>	break;
1833		}
1834		}
1835	<	return false;
1835	>	if (delta != 0)
1836	>	addCount((long)delta, binCount);
1837	>	return val;
1838		}
1839
1840		/**
1841	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1842	<	* specified value. Note: This method requires a full internal
1843	<	* traversal of the hash table, and so is much slower than
1844	<	* method <tt>containsKey</tt>.
1841	>	* Attempts to compute a mapping for the specified key and its
1842	>	* current mapped value (or {@code null} if there is no current
1843	>	* mapping). The entire method invocation is performed atomically.
1844	>	* Some attempted update operations on this map by other threads
1845	>	* may be blocked while computation is in progress, so the
1846	>	* computation should be short and simple, and must not attempt to
1847	>	* update any other mappings of this Map.
1848		*
1849	<	* @param value value whose presence in this map is to be tested
1850	<	* @return <tt>true</tt> if this map maps one or more keys to the
1851	<	*         specified value
1852	<	* @throws NullPointerException if the specified value is null
1849	>	* @param key key with which the specified value is to be associated
1850	>	* @param remappingFunction the function to compute a value
1851	>	* @return the new value associated with the specified key, or null if none
1852	>	* @throws NullPointerException if the specified key or remappingFunction
1853	>	*         is null
1854	>	* @throws IllegalStateException if the computation detectably
1855	>	*         attempts a recursive update to this map that would
1856	>	*         otherwise never complete
1857	>	* @throws RuntimeException or Error if the remappingFunction does so,
1858	>	*         in which case the mapping is unchanged
1859	>	*/
1860	>	public V compute(K key,
1861	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1862	>	if (key == null || remappingFunction == null)
1863	>	throw new NullPointerException();
1864	>	int h = spread(key.hashCode());
1865	>	V val = null;
1866	>	int delta = 0;
1867	>	int binCount = 0;
1868	>	for (Node<K,V>[] tab = table;;) {
1869	>	Node<K,V> f; int n, i, fh;
1870	>	if (tab == null || (n = tab.length) == 0)
1871	>	tab = initTable();
1872	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1873	>	Node<K,V> r = new ReservationNode<K,V>();
1874	>	synchronized (r) {
1875	>	if (casTabAt(tab, i, null, r)) {
1876	>	binCount = 1;
1877	>	Node<K,V> node = null;
1878	>	try {
1879	>	if ((val = remappingFunction.apply(key, null)) != null) {
1880	>	delta = 1;
1881	>	node = new Node<K,V>(h, key, val);
1882	>	}
1883	>	} finally {
1884	>	setTabAt(tab, i, node);
1885	>	}
1886	>	}
1887	>	}
1888	>	if (binCount != 0)
1889	>	break;
1890	>	}
1891	>	else if ((fh = f.hash) == MOVED)
1892	>	tab = helpTransfer(tab, f);
1893	>	else {
1894	>	synchronized (f) {
1895	>	if (tabAt(tab, i) == f) {
1896	>	if (fh >= 0) {
1897	>	binCount = 1;
1898	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1899	>	K ek;
1900	>	if (e.hash == h &&
1901	>	((ek = e.key) == key ||
1902	>	(ek != null && key.equals(ek)))) {
1903	>	val = remappingFunction.apply(key, e.val);
1904	>	if (val != null)
1905	>	e.val = val;
1906	>	else {
1907	>	delta = -1;
1908	>	Node<K,V> en = e.next;
1909	>	if (pred != null)
1910	>	pred.next = en;
1911	>	else
1912	>	setTabAt(tab, i, en);
1913	>	}
1914	>	break;
1915	>	}
1916	>	pred = e;
1917	>	if ((e = e.next) == null) {
1918	>	val = remappingFunction.apply(key, null);
1919	>	if (val != null) {
1920	>	if (pred.next != null)
1921	>	throw new IllegalStateException("Recursive update");
1922	>	delta = 1;
1923	>	pred.next = new Node<K,V>(h, key, val);
1924	>	}
1925	>	break;
1926	>	}
1927	>	}
1928	>	}
1929	>	else if (f instanceof TreeBin) {
1930	>	binCount = 1;
1931	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1932	>	TreeNode<K,V> r, p;
1933	>	if ((r = t.root) != null)
1934	>	p = r.findTreeNode(h, key, null);
1935	>	else
1936	>	p = null;
1937	>	V pv = (p == null) ? null : p.val;
1938	>	val = remappingFunction.apply(key, pv);
1939	>	if (val != null) {
1940	>	if (p != null)
1941	>	p.val = val;
1942	>	else {
1943	>	delta = 1;
1944	>	t.putTreeVal(h, key, val);
1945	>	}
1946	>	}
1947	>	else if (p != null) {
1948	>	delta = -1;
1949	>	if (t.removeTreeNode(p))
1950	>	setTabAt(tab, i, untreeify(t.first));
1951	>	}
1952	>	}
1953	>	else if (f instanceof ReservationNode)
1954	>	throw new IllegalStateException("Recursive update");
1955	>	}
1956	>	}
1957	>	if (binCount != 0) {
1958	>	if (binCount >= TREEIFY_THRESHOLD)
1959	>	treeifyBin(tab, i);
1960	>	break;
1961	>	}
1962	>	}
1963	>	}
1964	>	if (delta != 0)
1965	>	addCount((long)delta, binCount);
1966	>	return val;
1967	>	}
1968	>
1969	>	/**
1970	>	* If the specified key is not already associated with a
1971	>	* (non-null) value, associates it with the given value.
1972	>	* Otherwise, replaces the value with the results of the given
1973	>	* remapping function, or removes if {@code null}. The entire
1974	>	* method invocation is performed atomically.  Some attempted
1975	>	* update operations on this map by other threads may be blocked
1976	>	* while computation is in progress, so the computation should be
1977	>	* short and simple, and must not attempt to update any other
1978	>	* mappings of this Map.
1979	>	*
1980	>	* @param key key with which the specified value is to be associated
1981	>	* @param value the value to use if absent
1982	>	* @param remappingFunction the function to recompute a value if present
1983	>	* @return the new value associated with the specified key, or null if none
1984	>	* @throws NullPointerException if the specified key or the
1985	>	*         remappingFunction is null
1986	>	* @throws RuntimeException or Error if the remappingFunction does so,
1987	>	*         in which case the mapping is unchanged
1988		*/
1989	<	public boolean containsValue(Object value) {
1990	<	// Same idea as size()
940	<	if (value == null)
1989	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1990	>	if (key == null || value == null || remappingFunction == null)
1991		throw new NullPointerException();
1992	<	final Segment<K,V>[] segments = this.segments;
1993	<	long previousSum = 0L;
1994	<	int lockCount = 0;
1995	<	try {
1996	<	for (int retries = -1; ; retries++) {
1997	<	long sum = 0L;    // sum of modCounts
1998	<	for (int j = 0; j < segments.length; j++) {
1999	<	Segment<K,V> segment;
2000	<	if (retries == RETRIES_BEFORE_LOCK) {
2001	<	segment = ensureSegment(j);
2002	<	segment.lock();
2003	<	lockCount++;
2004	<	} else {
2005	<	segment = segmentAt(segments, j);
2006	<	if (segment == null)
2007	<	continue;
2008	<	}
2009	<	HashEntry<K,V>[] tab = segment.table;
2010	<	if (tab != null) {
2011	<	for (int i = 0 ; i < tab.length; i++) {
2012	<	HashEntry<K,V> e;
2013	<	for (e = entryAt(tab, i); e != null; e = e.next) {
2014	<	V v = e.value;
2015	<	if (v != null && value.equals(v))
2016	<	return true;
1992	>	int h = spread(key.hashCode());
1993	>	V val = null;
1994	>	int delta = 0;
1995	>	int binCount = 0;
1996	>	for (Node<K,V>[] tab = table;;) {
1997	>	Node<K,V> f; int n, i, fh;
1998	>	if (tab == null || (n = tab.length) == 0)
1999	>	tab = initTable();
2000	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2001	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2002	>	delta = 1;
2003	>	val = value;
2004	>	break;
2005	>	}
2006	>	}
2007	>	else if ((fh = f.hash) == MOVED)
2008	>	tab = helpTransfer(tab, f);
2009	>	else {
2010	>	synchronized (f) {
2011	>	if (tabAt(tab, i) == f) {
2012	>	if (fh >= 0) {
2013	>	binCount = 1;
2014	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
2015	>	K ek;
2016	>	if (e.hash == h &&
2017	>	((ek = e.key) == key ||
2018	>	(ek != null && key.equals(ek)))) {
2019	>	val = remappingFunction.apply(e.val, value);
2020	>	if (val != null)
2021	>	e.val = val;
2022	>	else {
2023	>	delta = -1;
2024	>	Node<K,V> en = e.next;
2025	>	if (pred != null)
2026	>	pred.next = en;
2027	>	else
2028	>	setTabAt(tab, i, en);
2029	>	}
2030	>	break;
2031	>	}
2032	>	pred = e;
2033	>	if ((e = e.next) == null) {
2034	>	delta = 1;
2035	>	val = value;
2036	>	pred.next = new Node<K,V>(h, key, val);
2037	>	break;
2038	>	}
2039	>	}
2040	>	}
2041	>	else if (f instanceof TreeBin) {
2042	>	binCount = 2;
2043	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2044	>	TreeNode<K,V> r = t.root;
2045	>	TreeNode<K,V> p = (r == null) ? null :
2046	>	r.findTreeNode(h, key, null);
2047	>	val = (p == null) ? value :
2048	>	remappingFunction.apply(p.val, value);
2049	>	if (val != null) {
2050	>	if (p != null)
2051	>	p.val = val;
2052	>	else {
2053	>	delta = 1;
2054	>	t.putTreeVal(h, key, val);
2055	>	}
2056	>	}
2057	>	else if (p != null) {
2058	>	delta = -1;
2059	>	if (t.removeTreeNode(p))
2060	>	setTabAt(tab, i, untreeify(t.first));
2061		}
2062		}
2063	<	sum += segment.modCount;
2063	>	else if (f instanceof ReservationNode)
2064	>	throw new IllegalStateException("Recursive update");
2065		}
2066		}
2067	<	if ((retries >= 0 && sum == previousSum) || lockCount > 0)
2068	<	return false;
2069	<	previousSum = sum;
2067	>	if (binCount != 0) {
2068	>	if (binCount >= TREEIFY_THRESHOLD)
2069	>	treeifyBin(tab, i);
2070	>	break;
2071	>	}
2072		}
976	–	} finally {
977	–	for (int j = 0; j < lockCount; j++)
978	–	segments[j].unlock();
2073		}
2074	+	if (delta != 0)
2075	+	addCount((long)delta, binCount);
2076	+	return val;
2077		}
2078
2079	+	// Hashtable legacy methods
2080	+
2081		/**
2082	<	* Legacy method testing if some key maps into the specified value
2083	<	* in this table.  This method is identical in functionality to
2084	<	* {@link #containsValue}, and exists solely to ensure
2082	>	* Tests if some key maps into the specified value in this table.
2083	>	*
2084	>	* <p>Note that this method is identical in functionality to
2085	>	* {@link #containsValue(Object)}, and exists solely to ensure
2086		* full compatibility with class {@link java.util.Hashtable},
2087		* which supported this method prior to introduction of the
2088	<	* Java Collections framework.
2088	>	* Java Collections Framework.
2089		*
2090		* @param  value a value to search for
2091	<	* @return <tt>true</tt> if and only if some key maps to the
2092	<	*         <tt>value</tt> argument in this table as
2093	<	*         determined by the <tt>equals</tt> method;
2094	<	*         <tt>false</tt> otherwise
2091	>	* @return {@code true} if and only if some key maps to the
2092	>	*         {@code value} argument in this table as
2093	>	*         determined by the {@code equals} method;
2094	>	*         {@code false} otherwise
2095		* @throws NullPointerException if the specified value is null
2096		*/
2097		public boolean contains(Object value) {
#	Line 999 | Line 2099 | public class ConcurrentHashMap<K, V> ext
2099		}
2100
2101		/**
2102	<	* Maps the specified key to the specified value in this table.
1003	<	* Neither the key nor the value can be null.
1004	<	*
1005	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1006	<	* with a key that is equal to the original key.
2102	>	* Returns an enumeration of the keys in this table.
2103		*
2104	<	* @param key key with which the specified value is to be associated
2105	<	* @param value value to be associated with the specified key
1010	<	* @return the previous value associated with <tt>key</tt>, or
1011	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1012	<	* @throws NullPointerException if the specified key or value is null
2104	>	* @return an enumeration of the keys in this table
2105	>	* @see #keySet()
2106		*/
2107	<	@SuppressWarnings("unchecked")
2108	<	public V put(K key, V value) {
2109	<	Segment<K,V> s;
2110	<	if (value == null)
1018	<	throw new NullPointerException();
1019	<	int hash = hash(key.hashCode());
1020	<	int j = (hash >>> segmentShift) & segmentMask;
1021	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1022	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1023	<	s = ensureSegment(j);
1024	<	return s.put(key, hash, value, false);
2107	>	public Enumeration<K> keys() {
2108	>	Node<K,V>[] t;
2109	>	int f = (t = table) == null ? 0 : t.length;
2110	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2111		}
2112
2113		/**
2114	<	* {@inheritDoc}
2114	>	* Returns an enumeration of the values in this table.
2115		*
2116	<	* @return the previous value associated with the specified key,
2117	<	*         or <tt>null</tt> if there was no mapping for the key
1032	<	* @throws NullPointerException if the specified key or value is null
2116	>	* @return an enumeration of the values in this table
2117	>	* @see #values()
2118		*/
2119	<	@SuppressWarnings("unchecked")
2120	<	public V putIfAbsent(K key, V value) {
2121	<	Segment<K,V> s;
2122	<	if (value == null)
1038	<	throw new NullPointerException();
1039	<	int hash = hash(key.hashCode());
1040	<	int j = (hash >>> segmentShift) & segmentMask;
1041	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1042	<	(segments, (j << SSHIFT) + SBASE)) == null)
1043	<	s = ensureSegment(j);
1044	<	return s.put(key, hash, value, true);
2119	>	public Enumeration<V> elements() {
2120	>	Node<K,V>[] t;
2121	>	int f = (t = table) == null ? 0 : t.length;
2122	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2123		}
2124
2125	+	// ConcurrentHashMap-only methods
2126	+
2127		/**
2128	<	* Copies all of the mappings from the specified map to this one.
2129	<	* These mappings replace any mappings that this map had for any of the
2130	<	* keys currently in the specified map.
2128	>	* Returns the number of mappings. This method should be used
2129	>	* instead of {@link #size} because a ConcurrentHashMap may
2130	>	* contain more mappings than can be represented as an int. The
2131	>	* value returned is an estimate; the actual count may differ if
2132	>	* there are concurrent insertions or removals.
2133		*
2134	<	* @param m mappings to be stored in this map
2134	>	* @return the number of mappings
2135	>	* @since 1.8
2136		*/
2137	<	public void putAll(Map<? extends K, ? extends V> m) {
2138	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2139	<	put(e.getKey(), e.getValue());
2137	>	public long mappingCount() {
2138	>	long n = sumCount();
2139	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2140		}
2141
2142		/**
2143	<	* Removes the key (and its corresponding value) from this map.
2144	<	* This method does nothing if the key is not in the map.
2143	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2144	>	* from the given type to {@code Boolean.TRUE}.
2145		*
2146	<	* @param  key the key that needs to be removed
2147	<	* @return the previous value associated with <tt>key</tt>, or
2148	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1066	<	* @throws NullPointerException if the specified key is null
2146	>	* @param <K> the element type of the returned set
2147	>	* @return the new set
2148	>	* @since 1.8
2149		*/
2150	<	public V remove(Object key) {
2151	<	int hash = hash(key.hashCode());
2152	<	Segment<K,V> s = segmentForHash(hash);
1071	<	return s == null ? null : s.remove(key, hash, null);
2150	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2151	>	return new KeySetView<K,Boolean>
2152	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2153		}
2154
2155		/**
2156	<	* {@inheritDoc}
2156	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2157	>	* from the given type to {@code Boolean.TRUE}.
2158		*
2159	<	* @throws NullPointerException if the specified key is null
2159	>	* @param initialCapacity The implementation performs internal
2160	>	* sizing to accommodate this many elements.
2161	>	* @param <K> the element type of the returned set
2162	>	* @return the new set
2163	>	* @throws IllegalArgumentException if the initial capacity of
2164	>	* elements is negative
2165	>	* @since 1.8
2166		*/
2167	<	public boolean remove(Object key, Object value) {
2168	<	int hash = hash(key.hashCode());
2169	<	Segment<K,V> s;
1082	<	return value != null && (s = segmentForHash(hash)) != null &&
1083	<	s.remove(key, hash, value) != null;
2167	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2168	>	return new KeySetView<K,Boolean>
2169	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2170		}
2171
2172		/**
2173	<	* {@inheritDoc}
2173	>	* Returns a {@link Set} view of the keys in this map, using the
2174	>	* given common mapped value for any additions (i.e., {@link
2175	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2176	>	* This is of course only appropriate if it is acceptable to use
2177	>	* the same value for all additions from this view.
2178		*
2179	<	* @throws NullPointerException if any of the arguments are null
2179	>	* @param mappedValue the mapped value to use for any additions
2180	>	* @return the set view
2181	>	* @throws NullPointerException if the mappedValue is null
2182		*/
2183	<	public boolean replace(K key, V oldValue, V newValue) {
2184	<	int hash = hash(key.hashCode());
1093	<	if (oldValue == null || newValue == null)
2183	>	public KeySetView<K,V> keySet(V mappedValue) {
2184	>	if (mappedValue == null)
2185		throw new NullPointerException();
2186	<	Segment<K,V> s = segmentForHash(hash);
1096	<	return s != null && s.replace(key, hash, oldValue, newValue);
2186	>	return new KeySetView<K,V>(this, mappedValue);
2187		}
2188
2189	+	/* ---------------- Special Nodes -------------- */
2190	+
2191		/**
2192	<	* {@inheritDoc}
1101	<	*
1102	<	* @return the previous value associated with the specified key,
1103	<	*         or <tt>null</tt> if there was no mapping for the key
1104	<	* @throws NullPointerException if the specified key or value is null
2192	>	* A node inserted at head of bins during transfer operations.
2193		*/
2194	<	public V replace(K key, V value) {
2195	<	int hash = hash(key.hashCode());
2196	<	if (value == null)
2197	<	throw new NullPointerException();
2198	<	Segment<K,V> s = segmentForHash(hash);
2199	<	return s == null ? null : s.replace(key, hash, value);
2194	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2195	>	final Node<K,V>[] nextTable;
2196	>	ForwardingNode(Node<K,V>[] tab) {
2197	>	super(MOVED, null, null);
2198	>	this.nextTable = tab;
2199	>	}
2200	>
2201	>	Node<K,V> find(int h, Object k) {
2202	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2203	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2204	>	Node<K,V> e; int n;
2205	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2206	>	(e = tabAt(tab, (n - 1) & h)) == null)
2207	>	return null;
2208	>	for (;;) {
2209	>	int eh; K ek;
2210	>	if ((eh = e.hash) == h &&
2211	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2212	>	return e;
2213	>	if (eh < 0) {
2214	>	if (e instanceof ForwardingNode) {
2215	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2216	>	continue outer;
2217	>	}
2218	>	else
2219	>	return e.find(h, k);
2220	>	}
2221	>	if ((e = e.next) == null)
2222	>	return null;
2223	>	}
2224	>	}
2225	>	}
2226		}
2227
2228		/**
2229	<	* Removes all of the mappings from this map.
2229	>	* A place-holder node used in computeIfAbsent and compute.
2230		*/
2231	<	public void clear() {
2232	<	final Segment<K,V>[] segments = this.segments;
2233	<	for (int j = 0; j < segments.length; ++j) {
2234	<	Segment<K,V> s = segmentAt(segments, j);
2235	<	if (s != null)
2236	<	s.clear();
2231	>	static final class ReservationNode<K,V> extends Node<K,V> {
2232	>	ReservationNode() {
2233	>	super(RESERVED, null, null);
2234	>	}
2235	>
2236	>	Node<K,V> find(int h, Object k) {
2237	>	return null;
2238		}
2239		}
2240
2241	+	/* ---------------- Table Initialization and Resizing -------------- */
2242	+
2243		/**
2244	<	* Returns a {@link Set} view of the keys contained in this map.
2245	<	* The set is backed by the map, so changes to the map are
2246	<	* reflected in the set, and vice-versa.  The set supports element
2247	<	* removal, which removes the corresponding mapping from this map,
2248	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1132	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1133	<	* operations.  It does not support the <tt>add</tt> or
1134	<	* <tt>addAll</tt> operations.
1135	<	*
1136	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1137	<	* that will never throw {@link ConcurrentModificationException},
1138	<	* and guarantees to traverse elements as they existed upon
1139	<	* construction of the iterator, and may (but is not guaranteed to)
1140	<	* reflect any modifications subsequent to construction.
1141	<	*/
1142	<	public Set<K> keySet() {
1143	<	Set<K> ks = keySet;
1144	<	return (ks != null) ? ks : (keySet = new KeySet());
2244	>	* Returns the stamp bits for resizing a table of size n.
2245	>	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2246	>	*/
2247	>	static final int resizeStamp(int n) {
2248	>	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2249		}
2250
2251		/**
2252	<	* Returns a {@link Collection} view of the values contained in this map.
1149	<	* The collection is backed by the map, so changes to the map are
1150	<	* reflected in the collection, and vice-versa.  The collection
1151	<	* supports element removal, which removes the corresponding
1152	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1153	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1154	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1155	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1156	<	*
1157	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1158	<	* that will never throw {@link ConcurrentModificationException},
1159	<	* and guarantees to traverse elements as they existed upon
1160	<	* construction of the iterator, and may (but is not guaranteed to)
1161	<	* reflect any modifications subsequent to construction.
2252	>	* Initializes table, using the size recorded in sizeCtl.
2253		*/
2254	<	public Collection<V> values() {
2255	<	Collection<V> vs = values;
2256	<	return (vs != null) ? vs : (values = new Values());
2254	>	private final Node<K,V>[] initTable() {
2255	>	Node<K,V>[] tab; int sc;
2256	>	while ((tab = table) == null || tab.length == 0) {
2257	>	if ((sc = sizeCtl) < 0)
2258	>	Thread.yield(); // lost initialization race; just spin
2259	>	else if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2260	>	try {
2261	>	if ((tab = table) == null || tab.length == 0) {
2262	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2263	>	@SuppressWarnings("unchecked")
2264	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2265	>	table = tab = nt;
2266	>	sc = n - (n >>> 2);
2267	>	}
2268	>	} finally {
2269	>	sizeCtl = sc;
2270	>	}
2271	>	break;
2272	>	}
2273	>	}
2274	>	return tab;
2275		}
2276
2277		/**
2278	<	* Returns a {@link Set} view of the mappings contained in this map.
2279	<	* The set is backed by the map, so changes to the map are
2280	<	* reflected in the set, and vice-versa.  The set supports element
2281	<	* removal, which removes the corresponding mapping from the map,
2282	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2283	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2284	<	* operations.  It does not support the <tt>add</tt> or
2285	<	* <tt>addAll</tt> operations.
1177	<	*
1178	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1179	<	* that will never throw {@link ConcurrentModificationException},
1180	<	* and guarantees to traverse elements as they existed upon
1181	<	* construction of the iterator, and may (but is not guaranteed to)
1182	<	* reflect any modifications subsequent to construction.
2278	>	* Adds to count, and if table is too small and not already
2279	>	* resizing, initiates transfer. If already resizing, helps
2280	>	* perform transfer if work is available.  Rechecks occupancy
2281	>	* after a transfer to see if another resize is already needed
2282	>	* because resizings are lagging additions.
2283	>	*
2284	>	* @param x the count to add
2285	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2286		*/
2287	<	public Set<Map.Entry<K,V>> entrySet() {
2288	<	Set<Map.Entry<K,V>> es = entrySet;
2289	<	return (es != null) ? es : (entrySet = new EntrySet());
2287	>	private final void addCount(long x, int check) {
2288	>	CounterCell[] cs; long b, s;
2289	>	if ((cs = counterCells) != null ||
2290	>	!U.compareAndSetLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2291	>	CounterCell c; long v; int m;
2292	>	boolean uncontended = true;
2293	>	if (cs == null || (m = cs.length - 1) < 0 ||
2294	>	(c = cs[ThreadLocalRandom.getProbe() & m]) == null ||
2295	>	!(uncontended =
2296	>	U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))) {
2297	>	fullAddCount(x, uncontended);
2298	>	return;
2299	>	}
2300	>	if (check <= 1)
2301	>	return;
2302	>	s = sumCount();
2303	>	}
2304	>	if (check >= 0) {
2305	>	Node<K,V>[] tab, nt; int n, sc;
2306	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2307	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2308	>	int rs = resizeStamp(n);
2309	>	if (sc < 0) {
2310	>	if ((sc >>> RESIZE_STAMP_SHIFT) == rs + 1 ||
2311	>	(sc >>> RESIZE_STAMP_SHIFT) == rs + MAX_RESIZERS ||
2312	>	(nt = nextTable) == null || transferIndex <= 0)
2313	>	break;
2314	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
2315	>	transfer(tab, nt);
2316	>	}
2317	>	else if (U.compareAndSetInt(this, SIZECTL, sc,
2318	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2319	>	transfer(tab, null);
2320	>	s = sumCount();
2321	>	}
2322	>	}
2323		}
2324
2325		/**
2326	<	* Returns an enumeration of the keys in this table.
1191	<	*
1192	<	* @return an enumeration of the keys in this table
1193	<	* @see #keySet()
2326	>	* Helps transfer if a resize is in progress.
2327		*/
2328	<	public Enumeration<K> keys() {
2329	<	return new KeyIterator();
2328	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2329	>	Node<K,V>[] nextTab; int sc;
2330	>	if (tab != null && (f instanceof ForwardingNode) &&
2331	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2332	>	int rs = resizeStamp(tab.length);
2333	>	while (nextTab == nextTable && table == tab &&
2334	>	(sc = sizeCtl) < 0) {
2335	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2336	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2337	>	break;
2338	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
2339	>	transfer(tab, nextTab);
2340	>	break;
2341	>	}
2342	>	}
2343	>	return nextTab;
2344	>	}
2345	>	return table;
2346		}
2347
2348		/**
2349	<	* Returns an enumeration of the values in this table.
2349	>	* Tries to presize table to accommodate the given number of elements.
2350		*
2351	<	* @return an enumeration of the values in this table
1203	<	* @see #values()
2351	>	* @param size number of elements (doesn't need to be perfectly accurate)
2352		*/
2353	<	public Enumeration<V> elements() {
2354	<	return new ValueIterator();
2353	>	private final void tryPresize(int size) {
2354	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2355	>	tableSizeFor(size + (size >>> 1) + 1);
2356	>	int sc;
2357	>	while ((sc = sizeCtl) >= 0) {
2358	>	Node<K,V>[] tab = table; int n;
2359	>	if (tab == null || (n = tab.length) == 0) {
2360	>	n = (sc > c) ? sc : c;
2361	>	if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2362	>	try {
2363	>	if (table == tab) {
2364	>	@SuppressWarnings("unchecked")
2365	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2366	>	table = nt;
2367	>	sc = n - (n >>> 2);
2368	>	}
2369	>	} finally {
2370	>	sizeCtl = sc;
2371	>	}
2372	>	}
2373	>	}
2374	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2375	>	break;
2376	>	else if (tab == table) {
2377	>	int rs = resizeStamp(n);
2378	>	if (U.compareAndSetInt(this, SIZECTL, sc,
2379	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2380	>	transfer(tab, null);
2381	>	}
2382	>	}
2383		}
2384
2385	<	/* ---------------- Iterator Support -------------- */
2385	>	/**
2386	>	* Moves and/or copies the nodes in each bin to new table. See
2387	>	* above for explanation.
2388	>	*/
2389	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2390	>	int n = tab.length, stride;
2391	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2392	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2393	>	if (nextTab == null) {            // initiating
2394	>	try {
2395	>	@SuppressWarnings("unchecked")
2396	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2397	>	nextTab = nt;
2398	>	} catch (Throwable ex) {      // try to cope with OOME
2399	>	sizeCtl = Integer.MAX_VALUE;
2400	>	return;
2401	>	}
2402	>	nextTable = nextTab;
2403	>	transferIndex = n;
2404	>	}
2405	>	int nextn = nextTab.length;
2406	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2407	>	boolean advance = true;
2408	>	boolean finishing = false; // to ensure sweep before committing nextTab
2409	>	for (int i = 0, bound = 0;;) {
2410	>	Node<K,V> f; int fh;
2411	>	while (advance) {
2412	>	int nextIndex, nextBound;
2413	>	if (--i >= bound || finishing)
2414	>	advance = false;
2415	>	else if ((nextIndex = transferIndex) <= 0) {
2416	>	i = -1;
2417	>	advance = false;
2418	>	}
2419	>	else if (U.compareAndSetInt
2420	>	(this, TRANSFERINDEX, nextIndex,
2421	>	nextBound = (nextIndex > stride ?
2422	>	nextIndex - stride : 0))) {
2423	>	bound = nextBound;
2424	>	i = nextIndex - 1;
2425	>	advance = false;
2426	>	}
2427	>	}
2428	>	if (i < 0 || i >= n || i + n >= nextn) {
2429	>	int sc;
2430	>	if (finishing) {
2431	>	nextTable = null;
2432	>	table = nextTab;
2433	>	sizeCtl = (n << 1) - (n >>> 1);
2434	>	return;
2435	>	}
2436	>	if (U.compareAndSetInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2437	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2438	>	return;
2439	>	finishing = advance = true;
2440	>	i = n; // recheck before commit
2441	>	}
2442	>	}
2443	>	else if ((f = tabAt(tab, i)) == null)
2444	>	advance = casTabAt(tab, i, null, fwd);
2445	>	else if ((fh = f.hash) == MOVED)
2446	>	advance = true; // already processed
2447	>	else {
2448	>	synchronized (f) {
2449	>	if (tabAt(tab, i) == f) {
2450	>	Node<K,V> ln, hn;
2451	>	if (fh >= 0) {
2452	>	int runBit = fh & n;
2453	>	Node<K,V> lastRun = f;
2454	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2455	>	int b = p.hash & n;
2456	>	if (b != runBit) {
2457	>	runBit = b;
2458	>	lastRun = p;
2459	>	}
2460	>	}
2461	>	if (runBit == 0) {
2462	>	ln = lastRun;
2463	>	hn = null;
2464	>	}
2465	>	else {
2466	>	hn = lastRun;
2467	>	ln = null;
2468	>	}
2469	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2470	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2471	>	if ((ph & n) == 0)
2472	>	ln = new Node<K,V>(ph, pk, pv, ln);
2473	>	else
2474	>	hn = new Node<K,V>(ph, pk, pv, hn);
2475	>	}
2476	>	setTabAt(nextTab, i, ln);
2477	>	setTabAt(nextTab, i + n, hn);
2478	>	setTabAt(tab, i, fwd);
2479	>	advance = true;
2480	>	}
2481	>	else if (f instanceof TreeBin) {
2482	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2483	>	TreeNode<K,V> lo = null, loTail = null;
2484	>	TreeNode<K,V> hi = null, hiTail = null;
2485	>	int lc = 0, hc = 0;
2486	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2487	>	int h = e.hash;
2488	>	TreeNode<K,V> p = new TreeNode<K,V>
2489	>	(h, e.key, e.val, null, null);
2490	>	if ((h & n) == 0) {
2491	>	if ((p.prev = loTail) == null)
2492	>	lo = p;
2493	>	else
2494	>	loTail.next = p;
2495	>	loTail = p;
2496	>	++lc;
2497	>	}
2498	>	else {
2499	>	if ((p.prev = hiTail) == null)
2500	>	hi = p;
2501	>	else
2502	>	hiTail.next = p;
2503	>	hiTail = p;
2504	>	++hc;
2505	>	}
2506	>	}
2507	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2508	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2509	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2510	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2511	>	setTabAt(nextTab, i, ln);
2512	>	setTabAt(nextTab, i + n, hn);
2513	>	setTabAt(tab, i, fwd);
2514	>	advance = true;
2515	>	}
2516	>	else if (f instanceof ReservationNode)
2517	>	throw new IllegalStateException("Recursive update");
2518	>	}
2519	>	}
2520	>	}
2521	>	}
2522	>	}
2523
2524	<	abstract class HashIterator {
1212	<	int nextSegmentIndex;
1213	<	int nextTableIndex;
1214	<	HashEntry<K,V>[] currentTable;
1215	<	HashEntry<K, V> nextEntry;
1216	<	HashEntry<K, V> lastReturned;
2524	>	/* ---------------- Counter support -------------- */
2525
2526	<	HashIterator() {
2527	<	nextSegmentIndex = segments.length - 1;
2528	<	nextTableIndex = -1;
2529	<	advance();
2526	>	/**
2527	>	* A padded cell for distributing counts.  Adapted from LongAdder
2528	>	* and Striped64.  See their internal docs for explanation.
2529	>	*/
2530	>	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2531	>	volatile long value;
2532	>	CounterCell(long x) { value = x; }
2533	>	}
2534	>
2535	>	final long sumCount() {
2536	>	CounterCell[] cs = counterCells;
2537	>	long sum = baseCount;
2538	>	if (cs != null) {
2539	>	for (CounterCell c : cs)
2540	>	if (c != null)
2541	>	sum += c.value;
2542	>	}
2543	>	return sum;
2544	>	}
2545	>
2546	>	// See LongAdder version for explanation
2547	>	private final void fullAddCount(long x, boolean wasUncontended) {
2548	>	int h;
2549	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2550	>	ThreadLocalRandom.localInit();      // force initialization
2551	>	h = ThreadLocalRandom.getProbe();
2552	>	wasUncontended = true;
2553	>	}
2554	>	boolean collide = false;                // True if last slot nonempty
2555	>	for (;;) {
2556	>	CounterCell[] cs; CounterCell c; int n; long v;
2557	>	if ((cs = counterCells) != null && (n = cs.length) > 0) {
2558	>	if ((c = cs[(n - 1) & h]) == null) {
2559	>	if (cellsBusy == 0) {            // Try to attach new Cell
2560	>	CounterCell r = new CounterCell(x); // Optimistic create
2561	>	if (cellsBusy == 0 &&
2562	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2563	>	boolean created = false;
2564	>	try {               // Recheck under lock
2565	>	CounterCell[] rs; int m, j;
2566	>	if ((rs = counterCells) != null &&
2567	>	(m = rs.length) > 0 &&
2568	>	rs[j = (m - 1) & h] == null) {
2569	>	rs[j] = r;
2570	>	created = true;
2571	>	}
2572	>	} finally {
2573	>	cellsBusy = 0;
2574	>	}
2575	>	if (created)
2576	>	break;
2577	>	continue;           // Slot is now non-empty
2578	>	}
2579	>	}
2580	>	collide = false;
2581	>	}
2582	>	else if (!wasUncontended)       // CAS already known to fail
2583	>	wasUncontended = true;      // Continue after rehash
2584	>	else if (U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))
2585	>	break;
2586	>	else if (counterCells != cs || n >= NCPU)
2587	>	collide = false;            // At max size or stale
2588	>	else if (!collide)
2589	>	collide = true;
2590	>	else if (cellsBusy == 0 &&
2591	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2592	>	try {
2593	>	if (counterCells == cs) // Expand table unless stale
2594	>	counterCells = Arrays.copyOf(cs, n << 1);
2595	>	} finally {
2596	>	cellsBusy = 0;
2597	>	}
2598	>	collide = false;
2599	>	continue;                   // Retry with expanded table
2600	>	}
2601	>	h = ThreadLocalRandom.advanceProbe(h);
2602	>	}
2603	>	else if (cellsBusy == 0 && counterCells == cs &&
2604	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2605	>	boolean init = false;
2606	>	try {                           // Initialize table
2607	>	if (counterCells == cs) {
2608	>	CounterCell[] rs = new CounterCell[2];
2609	>	rs[h & 1] = new CounterCell(x);
2610	>	counterCells = rs;
2611	>	init = true;
2612	>	}
2613	>	} finally {
2614	>	cellsBusy = 0;
2615	>	}
2616	>	if (init)
2617	>	break;
2618	>	}
2619	>	else if (U.compareAndSetLong(this, BASECOUNT, v = baseCount, v + x))
2620	>	break;                          // Fall back on using base
2621	>	}
2622	>	}
2623	>
2624	>	/* ---------------- Conversion from/to TreeBins -------------- */
2625	>
2626	>	/**
2627	>	* Replaces all linked nodes in bin at given index unless table is
2628	>	* too small, in which case resizes instead.
2629	>	*/
2630	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2631	>	Node<K,V> b; int n;
2632	>	if (tab != null) {
2633	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2634	>	tryPresize(n << 1);
2635	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2636	>	synchronized (b) {
2637	>	if (tabAt(tab, index) == b) {
2638	>	TreeNode<K,V> hd = null, tl = null;
2639	>	for (Node<K,V> e = b; e != null; e = e.next) {
2640	>	TreeNode<K,V> p =
2641	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2642	>	null, null);
2643	>	if ((p.prev = tl) == null)
2644	>	hd = p;
2645	>	else
2646	>	tl.next = p;
2647	>	tl = p;
2648	>	}
2649	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2650	>	}
2651	>	}
2652	>	}
2653	>	}
2654	>	}
2655	>
2656	>	/**
2657	>	* Returns a list of non-TreeNodes replacing those in given list.
2658	>	*/
2659	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2660	>	Node<K,V> hd = null, tl = null;
2661	>	for (Node<K,V> q = b; q != null; q = q.next) {
2662	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2663	>	if (tl == null)
2664	>	hd = p;
2665	>	else
2666	>	tl.next = p;
2667	>	tl = p;
2668	>	}
2669	>	return hd;
2670	>	}
2671	>
2672	>	/* ---------------- TreeNodes -------------- */
2673	>
2674	>	/**
2675	>	* Nodes for use in TreeBins.
2676	>	*/
2677	>	static final class TreeNode<K,V> extends Node<K,V> {
2678	>	TreeNode<K,V> parent;  // red-black tree links
2679	>	TreeNode<K,V> left;
2680	>	TreeNode<K,V> right;
2681	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2682	>	boolean red;
2683	>
2684	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2685	>	TreeNode<K,V> parent) {
2686	>	super(hash, key, val, next);
2687	>	this.parent = parent;
2688	>	}
2689	>
2690	>	Node<K,V> find(int h, Object k) {
2691	>	return findTreeNode(h, k, null);
2692		}
2693
2694		/**
2695	<	* Sets nextEntry to first node of next non-empty table
2696	<	* (in backwards order, to simplify checks).
2695	>	* Returns the TreeNode (or null if not found) for the given key
2696	>	* starting at given root.
2697		*/
2698	<	final void advance() {
2699	<	for (;;) {
2700	<	if (nextTableIndex >= 0) {
2701	<	if ((nextEntry = entryAt(currentTable,
2702	<	nextTableIndex--)) != null)
2703	<	break;
2698	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2699	>	if (k != null) {
2700	>	TreeNode<K,V> p = this;
2701	>	do {
2702	>	int ph, dir; K pk; TreeNode<K,V> q;
2703	>	TreeNode<K,V> pl = p.left, pr = p.right;
2704	>	if ((ph = p.hash) > h)
2705	>	p = pl;
2706	>	else if (ph < h)
2707	>	p = pr;
2708	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2709	>	return p;
2710	>	else if (pl == null)
2711	>	p = pr;
2712	>	else if (pr == null)
2713	>	p = pl;
2714	>	else if ((kc != null ||
2715	>	(kc = comparableClassFor(k)) != null) &&
2716	>	(dir = compareComparables(kc, k, pk)) != 0)
2717	>	p = (dir < 0) ? pl : pr;
2718	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2719	>	return q;
2720	>	else
2721	>	p = pl;
2722	>	} while (p != null);
2723	>	}
2724	>	return null;
2725	>	}
2726	>	}
2727	>
2728	>	/* ---------------- TreeBins -------------- */
2729	>
2730	>	/**
2731	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2732	>	* keys or values, but instead point to list of TreeNodes and
2733	>	* their root. They also maintain a parasitic read-write lock
2734	>	* forcing writers (who hold bin lock) to wait for readers (who do
2735	>	* not) to complete before tree restructuring operations.
2736	>	*/
2737	>	static final class TreeBin<K,V> extends Node<K,V> {
2738	>	TreeNode<K,V> root;
2739	>	volatile TreeNode<K,V> first;
2740	>	volatile Thread waiter;
2741	>	volatile int lockState;
2742	>	// values for lockState
2743	>	static final int WRITER = 1; // set while holding write lock
2744	>	static final int WAITER = 2; // set when waiting for write lock
2745	>	static final int READER = 4; // increment value for setting read lock
2746	>
2747	>	/**
2748	>	* Tie-breaking utility for ordering insertions when equal
2749	>	* hashCodes and non-comparable. We don't require a total
2750	>	* order, just a consistent insertion rule to maintain
2751	>	* equivalence across rebalancings. Tie-breaking further than
2752	>	* necessary simplifies testing a bit.
2753	>	*/
2754	>	static int tieBreakOrder(Object a, Object b) {
2755	>	int d;
2756	>	if (a == null || b == null ||
2757	>	(d = a.getClass().getName().
2758	>	compareTo(b.getClass().getName())) == 0)
2759	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2760	>	-1 : 1);
2761	>	return d;
2762	>	}
2763	>
2764	>	/**
2765	>	* Creates bin with initial set of nodes headed by b.
2766	>	*/
2767	>	TreeBin(TreeNode<K,V> b) {
2768	>	super(TREEBIN, null, null);
2769	>	this.first = b;
2770	>	TreeNode<K,V> r = null;
2771	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2772	>	next = (TreeNode<K,V>)x.next;
2773	>	x.left = x.right = null;
2774	>	if (r == null) {
2775	>	x.parent = null;
2776	>	x.red = false;
2777	>	r = x;
2778		}
2779	<	else if (nextSegmentIndex >= 0) {
2780	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2781	<	if (seg != null && (currentTable = seg.table) != null)
2782	<	nextTableIndex = currentTable.length - 1;
2779	>	else {
2780	>	K k = x.key;
2781	>	int h = x.hash;
2782	>	Class<?> kc = null;
2783	>	for (TreeNode<K,V> p = r;;) {
2784	>	int dir, ph;
2785	>	K pk = p.key;
2786	>	if ((ph = p.hash) > h)
2787	>	dir = -1;
2788	>	else if (ph < h)
2789	>	dir = 1;
2790	>	else if ((kc == null &&
2791	>	(kc = comparableClassFor(k)) == null) ||
2792	>	(dir = compareComparables(kc, k, pk)) == 0)
2793	>	dir = tieBreakOrder(k, pk);
2794	>	TreeNode<K,V> xp = p;
2795	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2796	>	x.parent = xp;
2797	>	if (dir <= 0)
2798	>	xp.left = x;
2799	>	else
2800	>	xp.right = x;
2801	>	r = balanceInsertion(r, x);
2802	>	break;
2803	>	}
2804	>	}
2805		}
2806	<	else
2806	>	}
2807	>	this.root = r;
2808	>	assert checkInvariants(root);
2809	>	}
2810	>
2811	>	/**
2812	>	* Acquires write lock for tree restructuring.
2813	>	*/
2814	>	private final void lockRoot() {
2815	>	if (!U.compareAndSetInt(this, LOCKSTATE, 0, WRITER))
2816	>	contendedLock(); // offload to separate method
2817	>	}
2818	>
2819	>	/**
2820	>	* Releases write lock for tree restructuring.
2821	>	*/
2822	>	private final void unlockRoot() {
2823	>	lockState = 0;
2824	>	}
2825	>
2826	>	/**
2827	>	* Possibly blocks awaiting root lock.
2828	>	*/
2829	>	private final void contendedLock() {
2830	>	boolean waiting = false;
2831	>	for (int s;;) {
2832	>	if (((s = lockState) & ~WAITER) == 0) {
2833	>	if (U.compareAndSetInt(this, LOCKSTATE, s, WRITER)) {
2834	>	if (waiting)
2835	>	waiter = null;
2836	>	return;
2837	>	}
2838	>	}
2839	>	else if ((s & WAITER) == 0) {
2840	>	if (U.compareAndSetInt(this, LOCKSTATE, s, s | WAITER)) {
2841	>	waiting = true;
2842	>	waiter = Thread.currentThread();
2843	>	}
2844	>	}
2845	>	else if (waiting)
2846	>	LockSupport.park(this);
2847	>	}
2848	>	}
2849	>
2850	>	/**
2851	>	* Returns matching node or null if none. Tries to search
2852	>	* using tree comparisons from root, but continues linear
2853	>	* search when lock not available.
2854	>	*/
2855	>	final Node<K,V> find(int h, Object k) {
2856	>	if (k != null) {
2857	>	for (Node<K,V> e = first; e != null; ) {
2858	>	int s; K ek;
2859	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2860	>	if (e.hash == h &&
2861	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2862	>	return e;
2863	>	e = e.next;
2864	>	}
2865	>	else if (U.compareAndSetInt(this, LOCKSTATE, s,
2866	>	s + READER)) {
2867	>	TreeNode<K,V> r, p;
2868	>	try {
2869	>	p = ((r = root) == null ? null :
2870	>	r.findTreeNode(h, k, null));
2871	>	} finally {
2872	>	Thread w;
2873	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2874	>	(READER|WAITER) && (w = waiter) != null)
2875	>	LockSupport.unpark(w);
2876	>	}
2877	>	return p;
2878	>	}
2879	>	}
2880	>	}
2881	>	return null;
2882	>	}
2883	>
2884	>	/**
2885	>	* Finds or adds a node.
2886	>	* @return null if added
2887	>	*/
2888	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2889	>	Class<?> kc = null;
2890	>	boolean searched = false;
2891	>	for (TreeNode<K,V> p = root;;) {
2892	>	int dir, ph; K pk;
2893	>	if (p == null) {
2894	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2895		break;
2896	+	}
2897	+	else if ((ph = p.hash) > h)
2898	+	dir = -1;
2899	+	else if (ph < h)
2900	+	dir = 1;
2901	+	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2902	+	return p;
2903	+	else if ((kc == null &&
2904	+	(kc = comparableClassFor(k)) == null) ||
2905	+	(dir = compareComparables(kc, k, pk)) == 0) {
2906	+	if (!searched) {
2907	+	TreeNode<K,V> q, ch;
2908	+	searched = true;
2909	+	if (((ch = p.left) != null &&
2910	+	(q = ch.findTreeNode(h, k, kc)) != null) ||
2911	+	((ch = p.right) != null &&
2912	+	(q = ch.findTreeNode(h, k, kc)) != null))
2913	+	return q;
2914	+	}
2915	+	dir = tieBreakOrder(k, pk);
2916	+	}
2917	+
2918	+	TreeNode<K,V> xp = p;
2919	+	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2920	+	TreeNode<K,V> x, f = first;
2921	+	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2922	+	if (f != null)
2923	+	f.prev = x;
2924	+	if (dir <= 0)
2925	+	xp.left = x;
2926	+	else
2927	+	xp.right = x;
2928	+	if (!xp.red)
2929	+	x.red = true;
2930	+	else {
2931	+	lockRoot();
2932	+	try {
2933	+	root = balanceInsertion(root, x);
2934	+	} finally {
2935	+	unlockRoot();
2936	+	}
2937	+	}
2938	+	break;
2939	+	}
2940		}
2941	+	assert checkInvariants(root);
2942	+	return null;
2943		}
2944
2945	<	final HashEntry<K,V> nextEntry() {
2946	<	HashEntry<K,V> e = nextEntry;
2947	<	if (e == null)
2948	<	throw new NoSuchElementException();
2949	<	lastReturned = e; // cannot assign until after null check
2950	<	if ((nextEntry = e.next) == null)
2951	<	advance();
2952	<	return e;
2945	>	/**
2946	>	* Removes the given node, that must be present before this
2947	>	* call.  This is messier than typical red-black deletion code
2948	>	* because we cannot swap the contents of an interior node
2949	>	* with a leaf successor that is pinned by "next" pointers
2950	>	* that are accessible independently of lock. So instead we
2951	>	* swap the tree linkages.
2952	>	*
2953	>	* @return true if now too small, so should be untreeified
2954	>	*/
2955	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2956	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2957	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2958	>	TreeNode<K,V> r, rl;
2959	>	if (pred == null)
2960	>	first = next;
2961	>	else
2962	>	pred.next = next;
2963	>	if (next != null)
2964	>	next.prev = pred;
2965	>	if (first == null) {
2966	>	root = null;
2967	>	return true;
2968	>	}
2969	>	if ((r = root) == null || r.right == null || // too small
2970	>	(rl = r.left) == null || rl.left == null)
2971	>	return true;
2972	>	lockRoot();
2973	>	try {
2974	>	TreeNode<K,V> replacement;
2975	>	TreeNode<K,V> pl = p.left;
2976	>	TreeNode<K,V> pr = p.right;
2977	>	if (pl != null && pr != null) {
2978	>	TreeNode<K,V> s = pr, sl;
2979	>	while ((sl = s.left) != null) // find successor
2980	>	s = sl;
2981	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2982	>	TreeNode<K,V> sr = s.right;
2983	>	TreeNode<K,V> pp = p.parent;
2984	>	if (s == pr) { // p was s's direct parent
2985	>	p.parent = s;
2986	>	s.right = p;
2987	>	}
2988	>	else {
2989	>	TreeNode<K,V> sp = s.parent;
2990	>	if ((p.parent = sp) != null) {
2991	>	if (s == sp.left)
2992	>	sp.left = p;
2993	>	else
2994	>	sp.right = p;
2995	>	}
2996	>	if ((s.right = pr) != null)
2997	>	pr.parent = s;
2998	>	}
2999	>	p.left = null;
3000	>	if ((p.right = sr) != null)
3001	>	sr.parent = p;
3002	>	if ((s.left = pl) != null)
3003	>	pl.parent = s;
3004	>	if ((s.parent = pp) == null)
3005	>	r = s;
3006	>	else if (p == pp.left)
3007	>	pp.left = s;
3008	>	else
3009	>	pp.right = s;
3010	>	if (sr != null)
3011	>	replacement = sr;
3012	>	else
3013	>	replacement = p;
3014	>	}
3015	>	else if (pl != null)
3016	>	replacement = pl;
3017	>	else if (pr != null)
3018	>	replacement = pr;
3019	>	else
3020	>	replacement = p;
3021	>	if (replacement != p) {
3022	>	TreeNode<K,V> pp = replacement.parent = p.parent;
3023	>	if (pp == null)
3024	>	r = replacement;
3025	>	else if (p == pp.left)
3026	>	pp.left = replacement;
3027	>	else
3028	>	pp.right = replacement;
3029	>	p.left = p.right = p.parent = null;
3030	>	}
3031	>
3032	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3033	>
3034	>	if (p == replacement) {  // detach pointers
3035	>	TreeNode<K,V> pp;
3036	>	if ((pp = p.parent) != null) {
3037	>	if (p == pp.left)
3038	>	pp.left = null;
3039	>	else if (p == pp.right)
3040	>	pp.right = null;
3041	>	p.parent = null;
3042	>	}
3043	>	}
3044	>	} finally {
3045	>	unlockRoot();
3046	>	}
3047	>	assert checkInvariants(root);
3048	>	return false;
3049		}
3050
3051	<	public final boolean hasNext() { return nextEntry != null; }
3052	<	public final boolean hasMoreElements() { return nextEntry != null; }
3051	>	/* ------------------------------------------------------------ */
3052	>	// Red-black tree methods, all adapted from CLR
3053	>
3054	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3055	>	TreeNode<K,V> p) {
3056	>	TreeNode<K,V> r, pp, rl;
3057	>	if (p != null && (r = p.right) != null) {
3058	>	if ((rl = p.right = r.left) != null)
3059	>	rl.parent = p;
3060	>	if ((pp = r.parent = p.parent) == null)
3061	>	(root = r).red = false;
3062	>	else if (pp.left == p)
3063	>	pp.left = r;
3064	>	else
3065	>	pp.right = r;
3066	>	r.left = p;
3067	>	p.parent = r;
3068	>	}
3069	>	return root;
3070	>	}
3071	>
3072	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3073	>	TreeNode<K,V> p) {
3074	>	TreeNode<K,V> l, pp, lr;
3075	>	if (p != null && (l = p.left) != null) {
3076	>	if ((lr = p.left = l.right) != null)
3077	>	lr.parent = p;
3078	>	if ((pp = l.parent = p.parent) == null)
3079	>	(root = l).red = false;
3080	>	else if (pp.right == p)
3081	>	pp.right = l;
3082	>	else
3083	>	pp.left = l;
3084	>	l.right = p;
3085	>	p.parent = l;
3086	>	}
3087	>	return root;
3088	>	}
3089	>
3090	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3091	>	TreeNode<K,V> x) {
3092	>	x.red = true;
3093	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3094	>	if ((xp = x.parent) == null) {
3095	>	x.red = false;
3096	>	return x;
3097	>	}
3098	>	else if (!xp.red || (xpp = xp.parent) == null)
3099	>	return root;
3100	>	if (xp == (xppl = xpp.left)) {
3101	>	if ((xppr = xpp.right) != null && xppr.red) {
3102	>	xppr.red = false;
3103	>	xp.red = false;
3104	>	xpp.red = true;
3105	>	x = xpp;
3106	>	}
3107	>	else {
3108	>	if (x == xp.right) {
3109	>	root = rotateLeft(root, x = xp);
3110	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3111	>	}
3112	>	if (xp != null) {
3113	>	xp.red = false;
3114	>	if (xpp != null) {
3115	>	xpp.red = true;
3116	>	root = rotateRight(root, xpp);
3117	>	}
3118	>	}
3119	>	}
3120	>	}
3121	>	else {
3122	>	if (xppl != null && xppl.red) {
3123	>	xppl.red = false;
3124	>	xp.red = false;
3125	>	xpp.red = true;
3126	>	x = xpp;
3127	>	}
3128	>	else {
3129	>	if (x == xp.left) {
3130	>	root = rotateRight(root, x = xp);
3131	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3132	>	}
3133	>	if (xp != null) {
3134	>	xp.red = false;
3135	>	if (xpp != null) {
3136	>	xpp.red = true;
3137	>	root = rotateLeft(root, xpp);
3138	>	}
3139	>	}
3140	>	}
3141	>	}
3142	>	}
3143	>	}
3144	>
3145	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3146	>	TreeNode<K,V> x) {
3147	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3148	>	if (x == null || x == root)
3149	>	return root;
3150	>	else if ((xp = x.parent) == null) {
3151	>	x.red = false;
3152	>	return x;
3153	>	}
3154	>	else if (x.red) {
3155	>	x.red = false;
3156	>	return root;
3157	>	}
3158	>	else if ((xpl = xp.left) == x) {
3159	>	if ((xpr = xp.right) != null && xpr.red) {
3160	>	xpr.red = false;
3161	>	xp.red = true;
3162	>	root = rotateLeft(root, xp);
3163	>	xpr = (xp = x.parent) == null ? null : xp.right;
3164	>	}
3165	>	if (xpr == null)
3166	>	x = xp;
3167	>	else {
3168	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3169	>	if ((sr == null || !sr.red) &&
3170	>	(sl == null || !sl.red)) {
3171	>	xpr.red = true;
3172	>	x = xp;
3173	>	}
3174	>	else {
3175	>	if (sr == null || !sr.red) {
3176	>	if (sl != null)
3177	>	sl.red = false;
3178	>	xpr.red = true;
3179	>	root = rotateRight(root, xpr);
3180	>	xpr = (xp = x.parent) == null ?
3181	>	null : xp.right;
3182	>	}
3183	>	if (xpr != null) {
3184	>	xpr.red = (xp == null) ? false : xp.red;
3185	>	if ((sr = xpr.right) != null)
3186	>	sr.red = false;
3187	>	}
3188	>	if (xp != null) {
3189	>	xp.red = false;
3190	>	root = rotateLeft(root, xp);
3191	>	}
3192	>	x = root;
3193	>	}
3194	>	}
3195	>	}
3196	>	else { // symmetric
3197	>	if (xpl != null && xpl.red) {
3198	>	xpl.red = false;
3199	>	xp.red = true;
3200	>	root = rotateRight(root, xp);
3201	>	xpl = (xp = x.parent) == null ? null : xp.left;
3202	>	}
3203	>	if (xpl == null)
3204	>	x = xp;
3205	>	else {
3206	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3207	>	if ((sl == null || !sl.red) &&
3208	>	(sr == null || !sr.red)) {
3209	>	xpl.red = true;
3210	>	x = xp;
3211	>	}
3212	>	else {
3213	>	if (sl == null || !sl.red) {
3214	>	if (sr != null)
3215	>	sr.red = false;
3216	>	xpl.red = true;
3217	>	root = rotateLeft(root, xpl);
3218	>	xpl = (xp = x.parent) == null ?
3219	>	null : xp.left;
3220	>	}
3221	>	if (xpl != null) {
3222	>	xpl.red = (xp == null) ? false : xp.red;
3223	>	if ((sl = xpl.left) != null)
3224	>	sl.red = false;
3225	>	}
3226	>	if (xp != null) {
3227	>	xp.red = false;
3228	>	root = rotateRight(root, xp);
3229	>	}
3230	>	x = root;
3231	>	}
3232	>	}
3233	>	}
3234	>	}
3235	>	}
3236	>
3237	>	/**
3238	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3239	>	*/
3240	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3241	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3242	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3243	>	if (tb != null && tb.next != t)
3244	>	return false;
3245	>	if (tn != null && tn.prev != t)
3246	>	return false;
3247	>	if (tp != null && t != tp.left && t != tp.right)
3248	>	return false;
3249	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3250	>	return false;
3251	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3252	>	return false;
3253	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3254	>	return false;
3255	>	if (tl != null && !checkInvariants(tl))
3256	>	return false;
3257	>	if (tr != null && !checkInvariants(tr))
3258	>	return false;
3259	>	return true;
3260	>	}
3261	>
3262	>	private static final Unsafe U = Unsafe.getUnsafe();
3263	>	private static final long LOCKSTATE;
3264	>	static {
3265	>	try {
3266	>	LOCKSTATE = U.objectFieldOffset
3267	>	(TreeBin.class.getDeclaredField("lockState"));
3268	>	} catch (ReflectiveOperationException e) {
3269	>	throw new ExceptionInInitializerError(e);
3270	>	}
3271	>	}
3272	>	}
3273	>
3274	>	/* ----------------Table Traversal -------------- */
3275	>
3276	>	/**
3277	>	* Records the table, its length, and current traversal index for a
3278	>	* traverser that must process a region of a forwarded table before
3279	>	* proceeding with current table.
3280	>	*/
3281	>	static final class TableStack<K,V> {
3282	>	int length;
3283	>	int index;
3284	>	Node<K,V>[] tab;
3285	>	TableStack<K,V> next;
3286	>	}
3287	>
3288	>	/**
3289	>	* Encapsulates traversal for methods such as containsValue; also
3290	>	* serves as a base class for other iterators and spliterators.
3291	>	*
3292	>	* Method advance visits once each still-valid node that was
3293	>	* reachable upon iterator construction. It might miss some that
3294	>	* were added to a bin after the bin was visited, which is OK wrt
3295	>	* consistency guarantees. Maintaining this property in the face
3296	>	* of possible ongoing resizes requires a fair amount of
3297	>	* bookkeeping state that is difficult to optimize away amidst
3298	>	* volatile accesses.  Even so, traversal maintains reasonable
3299	>	* throughput.
3300	>	*
3301	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3302	>	* However, if the table has been resized, then all future steps
3303	>	* must traverse both the bin at the current index as well as at
3304	>	* (index + baseSize); and so on for further resizings. To
3305	>	* paranoically cope with potential sharing by users of iterators
3306	>	* across threads, iteration terminates if a bounds checks fails
3307	>	* for a table read.
3308	>	*/
3309	>	static class Traverser<K,V> {
3310	>	Node<K,V>[] tab;        // current table; updated if resized
3311	>	Node<K,V> next;         // the next entry to use
3312	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3313	>	int index;              // index of bin to use next
3314	>	int baseIndex;          // current index of initial table
3315	>	int baseLimit;          // index bound for initial table
3316	>	final int baseSize;     // initial table size
3317	>
3318	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3319	>	this.tab = tab;
3320	>	this.baseSize = size;
3321	>	this.baseIndex = this.index = index;
3322	>	this.baseLimit = limit;
3323	>	this.next = null;
3324	>	}
3325	>
3326	>	/**
3327	>	* Advances if possible, returning next valid node, or null if none.
3328	>	*/
3329	>	final Node<K,V> advance() {
3330	>	Node<K,V> e;
3331	>	if ((e = next) != null)
3332	>	e = e.next;
3333	>	for (;;) {
3334	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3335	>	if (e != null)
3336	>	return next = e;
3337	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3338	>	(n = t.length) <= (i = index) || i < 0)
3339	>	return next = null;
3340	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3341	>	if (e instanceof ForwardingNode) {
3342	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3343	>	e = null;
3344	>	pushState(t, i, n);
3345	>	continue;
3346	>	}
3347	>	else if (e instanceof TreeBin)
3348	>	e = ((TreeBin<K,V>)e).first;
3349	>	else
3350	>	e = null;
3351	>	}
3352	>	if (stack != null)
3353	>	recoverState(n);
3354	>	else if ((index = i + baseSize) >= n)
3355	>	index = ++baseIndex; // visit upper slots if present
3356	>	}
3357	>	}
3358	>
3359	>	/**
3360	>	* Saves traversal state upon encountering a forwarding node.
3361	>	*/
3362	>	private void pushState(Node<K,V>[] t, int i, int n) {
3363	>	TableStack<K,V> s = spare;  // reuse if possible
3364	>	if (s != null)
3365	>	spare = s.next;
3366	>	else
3367	>	s = new TableStack<K,V>();
3368	>	s.tab = t;
3369	>	s.length = n;
3370	>	s.index = i;
3371	>	s.next = stack;
3372	>	stack = s;
3373	>	}
3374	>
3375	>	/**
3376	>	* Possibly pops traversal state.
3377	>	*
3378	>	* @param n length of current table
3379	>	*/
3380	>	private void recoverState(int n) {
3381	>	TableStack<K,V> s; int len;
3382	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3383	>	n = len;
3384	>	index = s.index;
3385	>	tab = s.tab;
3386	>	s.tab = null;
3387	>	TableStack<K,V> next = s.next;
3388	>	s.next = spare; // save for reuse
3389	>	stack = next;
3390	>	spare = s;
3391	>	}
3392	>	if (s == null && (index += baseSize) >= n)
3393	>	index = ++baseIndex;
3394	>	}
3395	>	}
3396	>
3397	>	/**
3398	>	* Base of key, value, and entry Iterators. Adds fields to
3399	>	* Traverser to support iterator.remove.
3400	>	*/
3401	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3402	>	final ConcurrentHashMap<K,V> map;
3403	>	Node<K,V> lastReturned;
3404	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3405	>	ConcurrentHashMap<K,V> map) {
3406	>	super(tab, size, index, limit);
3407	>	this.map = map;
3408	>	advance();
3409	>	}
3410	>
3411	>	public final boolean hasNext() { return next != null; }
3412	>	public final boolean hasMoreElements() { return next != null; }
3413
3414		public final void remove() {
3415	<	if (lastReturned == null)
3415	>	Node<K,V> p;
3416	>	if ((p = lastReturned) == null)
3417		throw new IllegalStateException();
1261	–	ConcurrentHashMap.this.remove(lastReturned.key);
3418		lastReturned = null;
3419	+	map.replaceNode(p.key, null, null);
3420		}
3421		}
3422
3423	<	final class KeyIterator
3424	<	extends HashIterator
3425	<	implements Iterator<K>, Enumeration<K>
3426	<	{
3427	<	public final K next()        { return super.nextEntry().key; }
3428	<	public final K nextElement() { return super.nextEntry().key; }
3423	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3424	>	implements Iterator<K>, Enumeration<K> {
3425	>	KeyIterator(Node<K,V>[] tab, int size, int index, int limit,
3426	>	ConcurrentHashMap<K,V> map) {
3427	>	super(tab, size, index, limit, map);
3428	>	}
3429	>
3430	>	public final K next() {
3431	>	Node<K,V> p;
3432	>	if ((p = next) == null)
3433	>	throw new NoSuchElementException();
3434	>	K k = p.key;
3435	>	lastReturned = p;
3436	>	advance();
3437	>	return k;
3438	>	}
3439	>
3440	>	public final K nextElement() { return next(); }
3441		}
3442
3443	<	final class ValueIterator
3444	<	extends HashIterator
3445	<	implements Iterator<V>, Enumeration<V>
3446	<	{
3447	<	public final V next()        { return super.nextEntry().value; }
3448	<	public final V nextElement() { return super.nextEntry().value; }
3443	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3444	>	implements Iterator<V>, Enumeration<V> {
3445	>	ValueIterator(Node<K,V>[] tab, int size, int index, int limit,
3446	>	ConcurrentHashMap<K,V> map) {
3447	>	super(tab, size, index, limit, map);
3448	>	}
3449	>
3450	>	public final V next() {
3451	>	Node<K,V> p;
3452	>	if ((p = next) == null)
3453	>	throw new NoSuchElementException();
3454	>	V v = p.val;
3455	>	lastReturned = p;
3456	>	advance();
3457	>	return v;
3458	>	}
3459	>
3460	>	public final V nextElement() { return next(); }
3461	>	}
3462	>
3463	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3464	>	implements Iterator<Map.Entry<K,V>> {
3465	>	EntryIterator(Node<K,V>[] tab, int size, int index, int limit,
3466	>	ConcurrentHashMap<K,V> map) {
3467	>	super(tab, size, index, limit, map);
3468	>	}
3469	>
3470	>	public final Map.Entry<K,V> next() {
3471	>	Node<K,V> p;
3472	>	if ((p = next) == null)
3473	>	throw new NoSuchElementException();
3474	>	K k = p.key;
3475	>	V v = p.val;
3476	>	lastReturned = p;
3477	>	advance();
3478	>	return new MapEntry<K,V>(k, v, map);
3479	>	}
3480		}
3481
3482		/**
3483	<	* Custom Entry class used by EntryIterator.next(), that relays
1284	<	* setValue changes to the underlying map.
3483	>	* Exported Entry for EntryIterator.
3484		*/
3485	<	final class WriteThroughEntry
3486	<	extends AbstractMap.SimpleEntry<K,V>
3487	<	{
3488	<	static final long serialVersionUID = 7249069246763182397L;
3489	<
3490	<	WriteThroughEntry(K k, V v) {
3491	<	super(k,v);
3485	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3486	>	final K key; // non-null
3487	>	V val;       // non-null
3488	>	final ConcurrentHashMap<K,V> map;
3489	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3490	>	this.key = key;
3491	>	this.val = val;
3492	>	this.map = map;
3493	>	}
3494	>	public K getKey()        { return key; }
3495	>	public V getValue()      { return val; }
3496	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3497	>	public String toString() {
3498	>	return Helpers.mapEntryToString(key, val);
3499	>	}
3500	>
3501	>	public boolean equals(Object o) {
3502	>	Object k, v; Map.Entry<?,?> e;
3503	>	return ((o instanceof Map.Entry) &&
3504	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3505	>	(v = e.getValue()) != null &&
3506	>	(k == key || k.equals(key)) &&
3507	>	(v == val || v.equals(val)));
3508		}
3509
3510		/**
3511		* Sets our entry's value and writes through to the map. The
3512	<	* value to return is somewhat arbitrary here. Since a
3513	<	* WriteThroughEntry does not necessarily track asynchronous
3514	<	* changes, the most recent "previous" value could be
3515	<	* different from what we return (or could even have been
3516	<	* removed in which case the put will re-establish). We do not
1302	<	* and cannot guarantee more.
3512	>	* value to return is somewhat arbitrary here. Since we do not
3513	>	* necessarily track asynchronous changes, the most recent
3514	>	* "previous" value could be different from what we return (or
3515	>	* could even have been removed, in which case the put will
3516	>	* re-establish). We do not and cannot guarantee more.
3517		*/
3518		public V setValue(V value) {
3519		if (value == null) throw new NullPointerException();
3520	<	V v = super.setValue(value);
3521	<	ConcurrentHashMap.this.put(getKey(), value);
3520	>	V v = val;
3521	>	val = value;
3522	>	map.put(key, value);
3523		return v;
3524		}
3525		}
3526
3527	<	final class EntryIterator
3528	<	extends HashIterator
3529	<	implements Iterator<Entry<K,V>>
3530	<	{
3531	<	public Map.Entry<K,V> next() {
3532	<	HashEntry<K,V> e = super.nextEntry();
3533	<	return new WriteThroughEntry(e.key, e.value);
3527	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3528	>	implements Spliterator<K> {
3529	>	long est;               // size estimate
3530	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3531	>	long est) {
3532	>	super(tab, size, index, limit);
3533	>	this.est = est;
3534	>	}
3535	>
3536	>	public KeySpliterator<K,V> trySplit() {
3537	>	int i, f, h;
3538	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3539	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3540	>	f, est >>>= 1);
3541	>	}
3542	>
3543	>	public void forEachRemaining(Consumer<? super K> action) {
3544	>	if (action == null) throw new NullPointerException();
3545	>	for (Node<K,V> p; (p = advance()) != null;)
3546	>	action.accept(p.key);
3547	>	}
3548	>
3549	>	public boolean tryAdvance(Consumer<? super K> action) {
3550	>	if (action == null) throw new NullPointerException();
3551	>	Node<K,V> p;
3552	>	if ((p = advance()) == null)
3553	>	return false;
3554	>	action.accept(p.key);
3555	>	return true;
3556	>	}
3557	>
3558	>	public long estimateSize() { return est; }
3559	>
3560	>	public int characteristics() {
3561	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3562	>	Spliterator.NONNULL;
3563		}
3564		}
3565
3566	<	final class KeySet extends AbstractSet<K> {
3567	<	public Iterator<K> iterator() {
3568	<	return new KeyIterator();
3566	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3567	>	implements Spliterator<V> {
3568	>	long est;               // size estimate
3569	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3570	>	long est) {
3571	>	super(tab, size, index, limit);
3572	>	this.est = est;
3573	>	}
3574	>
3575	>	public ValueSpliterator<K,V> trySplit() {
3576	>	int i, f, h;
3577	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3578	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3579	>	f, est >>>= 1);
3580		}
3581	<	public int size() {
3582	<	return ConcurrentHashMap.this.size();
3581	>
3582	>	public void forEachRemaining(Consumer<? super V> action) {
3583	>	if (action == null) throw new NullPointerException();
3584	>	for (Node<K,V> p; (p = advance()) != null;)
3585	>	action.accept(p.val);
3586		}
3587	<	public boolean isEmpty() {
3588	<	return ConcurrentHashMap.this.isEmpty();
3587	>
3588	>	public boolean tryAdvance(Consumer<? super V> action) {
3589	>	if (action == null) throw new NullPointerException();
3590	>	Node<K,V> p;
3591	>	if ((p = advance()) == null)
3592	>	return false;
3593	>	action.accept(p.val);
3594	>	return true;
3595		}
3596	<	public boolean contains(Object o) {
3597	<	return ConcurrentHashMap.this.containsKey(o);
3596	>
3597	>	public long estimateSize() { return est; }
3598	>
3599	>	public int characteristics() {
3600	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3601		}
3602	<	public boolean remove(Object o) {
3603	<	return ConcurrentHashMap.this.remove(o) != null;
3602	>	}
3603	>
3604	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3605	>	implements Spliterator<Map.Entry<K,V>> {
3606	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3607	>	long est;               // size estimate
3608	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3609	>	long est, ConcurrentHashMap<K,V> map) {
3610	>	super(tab, size, index, limit);
3611	>	this.map = map;
3612	>	this.est = est;
3613	>	}
3614	>
3615	>	public EntrySpliterator<K,V> trySplit() {
3616	>	int i, f, h;
3617	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3618	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3619	>	f, est >>>= 1, map);
3620	>	}
3621	>
3622	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3623	>	if (action == null) throw new NullPointerException();
3624	>	for (Node<K,V> p; (p = advance()) != null; )
3625	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3626	>	}
3627	>
3628	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3629	>	if (action == null) throw new NullPointerException();
3630	>	Node<K,V> p;
3631	>	if ((p = advance()) == null)
3632	>	return false;
3633	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3634	>	return true;
3635	>	}
3636	>
3637	>	public long estimateSize() { return est; }
3638	>
3639	>	public int characteristics() {
3640	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3641	>	Spliterator.NONNULL;
3642	>	}
3643	>	}
3644	>
3645	>	// Parallel bulk operations
3646	>
3647	>	/**
3648	>	* Computes initial batch value for bulk tasks. The returned value
3649	>	* is approximately exp2 of the number of times (minus one) to
3650	>	* split task by two before executing leaf action. This value is
3651	>	* faster to compute and more convenient to use as a guide to
3652	>	* splitting than is the depth, since it is used while dividing by
3653	>	* two anyway.
3654	>	*/
3655	>	final int batchFor(long b) {
3656	>	long n;
3657	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3658	>	return 0;
3659	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3660	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3661	>	}
3662	>
3663	>	/**
3664	>	* Performs the given action for each (key, value).
3665	>	*
3666	>	* @param parallelismThreshold the (estimated) number of elements
3667	>	* needed for this operation to be executed in parallel
3668	>	* @param action the action
3669	>	* @since 1.8
3670	>	*/
3671	>	public void forEach(long parallelismThreshold,
3672	>	BiConsumer<? super K,? super V> action) {
3673	>	if (action == null) throw new NullPointerException();
3674	>	new ForEachMappingTask<K,V>
3675	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3676	>	action).invoke();
3677	>	}
3678	>
3679	>	/**
3680	>	* Performs the given action for each non-null transformation
3681	>	* of each (key, value).
3682	>	*
3683	>	* @param parallelismThreshold the (estimated) number of elements
3684	>	* needed for this operation to be executed in parallel
3685	>	* @param transformer a function returning the transformation
3686	>	* for an element, or null if there is no transformation (in
3687	>	* which case the action is not applied)
3688	>	* @param action the action
3689	>	* @param <U> the return type of the transformer
3690	>	* @since 1.8
3691	>	*/
3692	>	public <U> void forEach(long parallelismThreshold,
3693	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3694	>	Consumer<? super U> action) {
3695	>	if (transformer == null || action == null)
3696	>	throw new NullPointerException();
3697	>	new ForEachTransformedMappingTask<K,V,U>
3698	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3699	>	transformer, action).invoke();
3700	>	}
3701	>
3702	>	/**
3703	>	* Returns a non-null result from applying the given search
3704	>	* function on each (key, value), or null if none.  Upon
3705	>	* success, further element processing is suppressed and the
3706	>	* results of any other parallel invocations of the search
3707	>	* function are ignored.
3708	>	*
3709	>	* @param parallelismThreshold the (estimated) number of elements
3710	>	* needed for this operation to be executed in parallel
3711	>	* @param searchFunction a function returning a non-null
3712	>	* result on success, else null
3713	>	* @param <U> the return type of the search function
3714	>	* @return a non-null result from applying the given search
3715	>	* function on each (key, value), or null if none
3716	>	* @since 1.8
3717	>	*/
3718	>	public <U> U search(long parallelismThreshold,
3719	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3720	>	if (searchFunction == null) throw new NullPointerException();
3721	>	return new SearchMappingsTask<K,V,U>
3722	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3723	>	searchFunction, new AtomicReference<U>()).invoke();
3724	>	}
3725	>
3726	>	/**
3727	>	* Returns the result of accumulating the given transformation
3728	>	* of all (key, value) pairs using the given reducer to
3729	>	* combine values, or null if none.
3730	>	*
3731	>	* @param parallelismThreshold the (estimated) number of elements
3732	>	* needed for this operation to be executed in parallel
3733	>	* @param transformer a function returning the transformation
3734	>	* for an element, or null if there is no transformation (in
3735	>	* which case it is not combined)
3736	>	* @param reducer a commutative associative combining function
3737	>	* @param <U> the return type of the transformer
3738	>	* @return the result of accumulating the given transformation
3739	>	* of all (key, value) pairs
3740	>	* @since 1.8
3741	>	*/
3742	>	public <U> U reduce(long parallelismThreshold,
3743	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3744	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3745	>	if (transformer == null || reducer == null)
3746	>	throw new NullPointerException();
3747	>	return new MapReduceMappingsTask<K,V,U>
3748	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3749	>	null, transformer, reducer).invoke();
3750	>	}
3751	>
3752	>	/**
3753	>	* Returns the result of accumulating the given transformation
3754	>	* of all (key, value) pairs using the given reducer to
3755	>	* combine values, and the given basis as an identity value.
3756	>	*
3757	>	* @param parallelismThreshold the (estimated) number of elements
3758	>	* needed for this operation to be executed in parallel
3759	>	* @param transformer a function returning the transformation
3760	>	* for an element
3761	>	* @param basis the identity (initial default value) for the reduction
3762	>	* @param reducer a commutative associative combining function
3763	>	* @return the result of accumulating the given transformation
3764	>	* of all (key, value) pairs
3765	>	* @since 1.8
3766	>	*/
3767	>	public double reduceToDouble(long parallelismThreshold,
3768	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3769	>	double basis,
3770	>	DoubleBinaryOperator reducer) {
3771	>	if (transformer == null || reducer == null)
3772	>	throw new NullPointerException();
3773	>	return new MapReduceMappingsToDoubleTask<K,V>
3774	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3775	>	null, transformer, basis, reducer).invoke();
3776	>	}
3777	>
3778	>	/**
3779	>	* Returns the result of accumulating the given transformation
3780	>	* of all (key, value) pairs using the given reducer to
3781	>	* combine values, and the given basis as an identity value.
3782	>	*
3783	>	* @param parallelismThreshold the (estimated) number of elements
3784	>	* needed for this operation to be executed in parallel
3785	>	* @param transformer a function returning the transformation
3786	>	* for an element
3787	>	* @param basis the identity (initial default value) for the reduction
3788	>	* @param reducer a commutative associative combining function
3789	>	* @return the result of accumulating the given transformation
3790	>	* of all (key, value) pairs
3791	>	* @since 1.8
3792	>	*/
3793	>	public long reduceToLong(long parallelismThreshold,
3794	>	ToLongBiFunction<? super K, ? super V> transformer,
3795	>	long basis,
3796	>	LongBinaryOperator reducer) {
3797	>	if (transformer == null || reducer == null)
3798	>	throw new NullPointerException();
3799	>	return new MapReduceMappingsToLongTask<K,V>
3800	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3801	>	null, transformer, basis, reducer).invoke();
3802	>	}
3803	>
3804	>	/**
3805	>	* Returns the result of accumulating the given transformation
3806	>	* of all (key, value) pairs using the given reducer to
3807	>	* combine values, and the given basis as an identity value.
3808	>	*
3809	>	* @param parallelismThreshold the (estimated) number of elements
3810	>	* needed for this operation to be executed in parallel
3811	>	* @param transformer a function returning the transformation
3812	>	* for an element
3813	>	* @param basis the identity (initial default value) for the reduction
3814	>	* @param reducer a commutative associative combining function
3815	>	* @return the result of accumulating the given transformation
3816	>	* of all (key, value) pairs
3817	>	* @since 1.8
3818	>	*/
3819	>	public int reduceToInt(long parallelismThreshold,
3820	>	ToIntBiFunction<? super K, ? super V> transformer,
3821	>	int basis,
3822	>	IntBinaryOperator reducer) {
3823	>	if (transformer == null || reducer == null)
3824	>	throw new NullPointerException();
3825	>	return new MapReduceMappingsToIntTask<K,V>
3826	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3827	>	null, transformer, basis, reducer).invoke();
3828	>	}
3829	>
3830	>	/**
3831	>	* Performs the given action for each key.
3832	>	*
3833	>	* @param parallelismThreshold the (estimated) number of elements
3834	>	* needed for this operation to be executed in parallel
3835	>	* @param action the action
3836	>	* @since 1.8
3837	>	*/
3838	>	public void forEachKey(long parallelismThreshold,
3839	>	Consumer<? super K> action) {
3840	>	if (action == null) throw new NullPointerException();
3841	>	new ForEachKeyTask<K,V>
3842	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3843	>	action).invoke();
3844	>	}
3845	>
3846	>	/**
3847	>	* Performs the given action for each non-null transformation
3848	>	* of each key.
3849	>	*
3850	>	* @param parallelismThreshold the (estimated) number of elements
3851	>	* needed for this operation to be executed in parallel
3852	>	* @param transformer a function returning the transformation
3853	>	* for an element, or null if there is no transformation (in
3854	>	* which case the action is not applied)
3855	>	* @param action the action
3856	>	* @param <U> the return type of the transformer
3857	>	* @since 1.8
3858	>	*/
3859	>	public <U> void forEachKey(long parallelismThreshold,
3860	>	Function<? super K, ? extends U> transformer,
3861	>	Consumer<? super U> action) {
3862	>	if (transformer == null || action == null)
3863	>	throw new NullPointerException();
3864	>	new ForEachTransformedKeyTask<K,V,U>
3865	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3866	>	transformer, action).invoke();
3867	>	}
3868	>
3869	>	/**
3870	>	* Returns a non-null result from applying the given search
3871	>	* function on each key, or null if none. Upon success,
3872	>	* further element processing is suppressed and the results of
3873	>	* any other parallel invocations of the search function are
3874	>	* ignored.
3875	>	*
3876	>	* @param parallelismThreshold the (estimated) number of elements
3877	>	* needed for this operation to be executed in parallel
3878	>	* @param searchFunction a function returning a non-null
3879	>	* result on success, else null
3880	>	* @param <U> the return type of the search function
3881	>	* @return a non-null result from applying the given search
3882	>	* function on each key, or null if none
3883	>	* @since 1.8
3884	>	*/
3885	>	public <U> U searchKeys(long parallelismThreshold,
3886	>	Function<? super K, ? extends U> searchFunction) {
3887	>	if (searchFunction == null) throw new NullPointerException();
3888	>	return new SearchKeysTask<K,V,U>
3889	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3890	>	searchFunction, new AtomicReference<U>()).invoke();
3891	>	}
3892	>
3893	>	/**
3894	>	* Returns the result of accumulating all keys using the given
3895	>	* reducer to combine values, or null if none.
3896	>	*
3897	>	* @param parallelismThreshold the (estimated) number of elements
3898	>	* needed for this operation to be executed in parallel
3899	>	* @param reducer a commutative associative combining function
3900	>	* @return the result of accumulating all keys using the given
3901	>	* reducer to combine values, or null if none
3902	>	* @since 1.8
3903	>	*/
3904	>	public K reduceKeys(long parallelismThreshold,
3905	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3906	>	if (reducer == null) throw new NullPointerException();
3907	>	return new ReduceKeysTask<K,V>
3908	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3909	>	null, reducer).invoke();
3910	>	}
3911	>
3912	>	/**
3913	>	* Returns the result of accumulating the given transformation
3914	>	* of all keys using the given reducer to combine values, or
3915	>	* null if none.
3916	>	*
3917	>	* @param parallelismThreshold the (estimated) number of elements
3918	>	* needed for this operation to be executed in parallel
3919	>	* @param transformer a function returning the transformation
3920	>	* for an element, or null if there is no transformation (in
3921	>	* which case it is not combined)
3922	>	* @param reducer a commutative associative combining function
3923	>	* @param <U> the return type of the transformer
3924	>	* @return the result of accumulating the given transformation
3925	>	* of all keys
3926	>	* @since 1.8
3927	>	*/
3928	>	public <U> U reduceKeys(long parallelismThreshold,
3929	>	Function<? super K, ? extends U> transformer,
3930	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3931	>	if (transformer == null || reducer == null)
3932	>	throw new NullPointerException();
3933	>	return new MapReduceKeysTask<K,V,U>
3934	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3935	>	null, transformer, reducer).invoke();
3936	>	}
3937	>
3938	>	/**
3939	>	* Returns the result of accumulating the given transformation
3940	>	* of all keys using the given reducer to combine values, and
3941	>	* the given basis as an identity value.
3942	>	*
3943	>	* @param parallelismThreshold the (estimated) number of elements
3944	>	* needed for this operation to be executed in parallel
3945	>	* @param transformer a function returning the transformation
3946	>	* for an element
3947	>	* @param basis the identity (initial default value) for the reduction
3948	>	* @param reducer a commutative associative combining function
3949	>	* @return the result of accumulating the given transformation
3950	>	* of all keys
3951	>	* @since 1.8
3952	>	*/
3953	>	public double reduceKeysToDouble(long parallelismThreshold,
3954	>	ToDoubleFunction<? super K> transformer,
3955	>	double basis,
3956	>	DoubleBinaryOperator reducer) {
3957	>	if (transformer == null || reducer == null)
3958	>	throw new NullPointerException();
3959	>	return new MapReduceKeysToDoubleTask<K,V>
3960	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3961	>	null, transformer, basis, reducer).invoke();
3962	>	}
3963	>
3964	>	/**
3965	>	* Returns the result of accumulating the given transformation
3966	>	* of all keys using the given reducer to combine values, and
3967	>	* the given basis as an identity value.
3968	>	*
3969	>	* @param parallelismThreshold the (estimated) number of elements
3970	>	* needed for this operation to be executed in parallel
3971	>	* @param transformer a function returning the transformation
3972	>	* for an element
3973	>	* @param basis the identity (initial default value) for the reduction
3974	>	* @param reducer a commutative associative combining function
3975	>	* @return the result of accumulating the given transformation
3976	>	* of all keys
3977	>	* @since 1.8
3978	>	*/
3979	>	public long reduceKeysToLong(long parallelismThreshold,
3980	>	ToLongFunction<? super K> transformer,
3981	>	long basis,
3982	>	LongBinaryOperator reducer) {
3983	>	if (transformer == null || reducer == null)
3984	>	throw new NullPointerException();
3985	>	return new MapReduceKeysToLongTask<K,V>
3986	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3987	>	null, transformer, basis, reducer).invoke();
3988	>	}
3989	>
3990	>	/**
3991	>	* Returns the result of accumulating the given transformation
3992	>	* of all keys using the given reducer to combine values, and
3993	>	* the given basis as an identity value.
3994	>	*
3995	>	* @param parallelismThreshold the (estimated) number of elements
3996	>	* needed for this operation to be executed in parallel
3997	>	* @param transformer a function returning the transformation
3998	>	* for an element
3999	>	* @param basis the identity (initial default value) for the reduction
4000	>	* @param reducer a commutative associative combining function
4001	>	* @return the result of accumulating the given transformation
4002	>	* of all keys
4003	>	* @since 1.8
4004	>	*/
4005	>	public int reduceKeysToInt(long parallelismThreshold,
4006	>	ToIntFunction<? super K> transformer,
4007	>	int basis,
4008	>	IntBinaryOperator reducer) {
4009	>	if (transformer == null || reducer == null)
4010	>	throw new NullPointerException();
4011	>	return new MapReduceKeysToIntTask<K,V>
4012	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4013	>	null, transformer, basis, reducer).invoke();
4014	>	}
4015	>
4016	>	/**
4017	>	* Performs the given action for each value.
4018	>	*
4019	>	* @param parallelismThreshold the (estimated) number of elements
4020	>	* needed for this operation to be executed in parallel
4021	>	* @param action the action
4022	>	* @since 1.8
4023	>	*/
4024	>	public void forEachValue(long parallelismThreshold,
4025	>	Consumer<? super V> action) {
4026	>	if (action == null)
4027	>	throw new NullPointerException();
4028	>	new ForEachValueTask<K,V>
4029	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4030	>	action).invoke();
4031	>	}
4032	>
4033	>	/**
4034	>	* Performs the given action for each non-null transformation
4035	>	* of each value.
4036	>	*
4037	>	* @param parallelismThreshold the (estimated) number of elements
4038	>	* needed for this operation to be executed in parallel
4039	>	* @param transformer a function returning the transformation
4040	>	* for an element, or null if there is no transformation (in
4041	>	* which case the action is not applied)
4042	>	* @param action the action
4043	>	* @param <U> the return type of the transformer
4044	>	* @since 1.8
4045	>	*/
4046	>	public <U> void forEachValue(long parallelismThreshold,
4047	>	Function<? super V, ? extends U> transformer,
4048	>	Consumer<? super U> action) {
4049	>	if (transformer == null || action == null)
4050	>	throw new NullPointerException();
4051	>	new ForEachTransformedValueTask<K,V,U>
4052	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4053	>	transformer, action).invoke();
4054	>	}
4055	>
4056	>	/**
4057	>	* Returns a non-null result from applying the given search
4058	>	* function on each value, or null if none.  Upon success,
4059	>	* further element processing is suppressed and the results of
4060	>	* any other parallel invocations of the search function are
4061	>	* ignored.
4062	>	*
4063	>	* @param parallelismThreshold the (estimated) number of elements
4064	>	* needed for this operation to be executed in parallel
4065	>	* @param searchFunction a function returning a non-null
4066	>	* result on success, else null
4067	>	* @param <U> the return type of the search function
4068	>	* @return a non-null result from applying the given search
4069	>	* function on each value, or null if none
4070	>	* @since 1.8
4071	>	*/
4072	>	public <U> U searchValues(long parallelismThreshold,
4073	>	Function<? super V, ? extends U> searchFunction) {
4074	>	if (searchFunction == null) throw new NullPointerException();
4075	>	return new SearchValuesTask<K,V,U>
4076	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4077	>	searchFunction, new AtomicReference<U>()).invoke();
4078	>	}
4079	>
4080	>	/**
4081	>	* Returns the result of accumulating all values using the
4082	>	* given reducer to combine values, or null if none.
4083	>	*
4084	>	* @param parallelismThreshold the (estimated) number of elements
4085	>	* needed for this operation to be executed in parallel
4086	>	* @param reducer a commutative associative combining function
4087	>	* @return the result of accumulating all values
4088	>	* @since 1.8
4089	>	*/
4090	>	public V reduceValues(long parallelismThreshold,
4091	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4092	>	if (reducer == null) throw new NullPointerException();
4093	>	return new ReduceValuesTask<K,V>
4094	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4095	>	null, reducer).invoke();
4096	>	}
4097	>
4098	>	/**
4099	>	* Returns the result of accumulating the given transformation
4100	>	* of all values using the given reducer to combine values, or
4101	>	* null if none.
4102	>	*
4103	>	* @param parallelismThreshold the (estimated) number of elements
4104	>	* needed for this operation to be executed in parallel
4105	>	* @param transformer a function returning the transformation
4106	>	* for an element, or null if there is no transformation (in
4107	>	* which case it is not combined)
4108	>	* @param reducer a commutative associative combining function
4109	>	* @param <U> the return type of the transformer
4110	>	* @return the result of accumulating the given transformation
4111	>	* of all values
4112	>	* @since 1.8
4113	>	*/
4114	>	public <U> U reduceValues(long parallelismThreshold,
4115	>	Function<? super V, ? extends U> transformer,
4116	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4117	>	if (transformer == null || reducer == null)
4118	>	throw new NullPointerException();
4119	>	return new MapReduceValuesTask<K,V,U>
4120	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4121	>	null, transformer, reducer).invoke();
4122	>	}
4123	>
4124	>	/**
4125	>	* Returns the result of accumulating the given transformation
4126	>	* of all values using the given reducer to combine values,
4127	>	* and the given basis as an identity value.
4128	>	*
4129	>	* @param parallelismThreshold the (estimated) number of elements
4130	>	* needed for this operation to be executed in parallel
4131	>	* @param transformer a function returning the transformation
4132	>	* for an element
4133	>	* @param basis the identity (initial default value) for the reduction
4134	>	* @param reducer a commutative associative combining function
4135	>	* @return the result of accumulating the given transformation
4136	>	* of all values
4137	>	* @since 1.8
4138	>	*/
4139	>	public double reduceValuesToDouble(long parallelismThreshold,
4140	>	ToDoubleFunction<? super V> transformer,
4141	>	double basis,
4142	>	DoubleBinaryOperator reducer) {
4143	>	if (transformer == null || reducer == null)
4144	>	throw new NullPointerException();
4145	>	return new MapReduceValuesToDoubleTask<K,V>
4146	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4147	>	null, transformer, basis, reducer).invoke();
4148	>	}
4149	>
4150	>	/**
4151	>	* Returns the result of accumulating the given transformation
4152	>	* of all values using the given reducer to combine values,
4153	>	* and the given basis as an identity value.
4154	>	*
4155	>	* @param parallelismThreshold the (estimated) number of elements
4156	>	* needed for this operation to be executed in parallel
4157	>	* @param transformer a function returning the transformation
4158	>	* for an element
4159	>	* @param basis the identity (initial default value) for the reduction
4160	>	* @param reducer a commutative associative combining function
4161	>	* @return the result of accumulating the given transformation
4162	>	* of all values
4163	>	* @since 1.8
4164	>	*/
4165	>	public long reduceValuesToLong(long parallelismThreshold,
4166	>	ToLongFunction<? super V> transformer,
4167	>	long basis,
4168	>	LongBinaryOperator reducer) {
4169	>	if (transformer == null || reducer == null)
4170	>	throw new NullPointerException();
4171	>	return new MapReduceValuesToLongTask<K,V>
4172	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4173	>	null, transformer, basis, reducer).invoke();
4174	>	}
4175	>
4176	>	/**
4177	>	* Returns the result of accumulating the given transformation
4178	>	* of all values using the given reducer to combine values,
4179	>	* and the given basis as an identity value.
4180	>	*
4181	>	* @param parallelismThreshold the (estimated) number of elements
4182	>	* needed for this operation to be executed in parallel
4183	>	* @param transformer a function returning the transformation
4184	>	* for an element
4185	>	* @param basis the identity (initial default value) for the reduction
4186	>	* @param reducer a commutative associative combining function
4187	>	* @return the result of accumulating the given transformation
4188	>	* of all values
4189	>	* @since 1.8
4190	>	*/
4191	>	public int reduceValuesToInt(long parallelismThreshold,
4192	>	ToIntFunction<? super V> transformer,
4193	>	int basis,
4194	>	IntBinaryOperator reducer) {
4195	>	if (transformer == null || reducer == null)
4196	>	throw new NullPointerException();
4197	>	return new MapReduceValuesToIntTask<K,V>
4198	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4199	>	null, transformer, basis, reducer).invoke();
4200	>	}
4201	>
4202	>	/**
4203	>	* Performs the given action for each entry.
4204	>	*
4205	>	* @param parallelismThreshold the (estimated) number of elements
4206	>	* needed for this operation to be executed in parallel
4207	>	* @param action the action
4208	>	* @since 1.8
4209	>	*/
4210	>	public void forEachEntry(long parallelismThreshold,
4211	>	Consumer<? super Map.Entry<K,V>> action) {
4212	>	if (action == null) throw new NullPointerException();
4213	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4214	>	action).invoke();
4215	>	}
4216	>
4217	>	/**
4218	>	* Performs the given action for each non-null transformation
4219	>	* of each entry.
4220	>	*
4221	>	* @param parallelismThreshold the (estimated) number of elements
4222	>	* needed for this operation to be executed in parallel
4223	>	* @param transformer a function returning the transformation
4224	>	* for an element, or null if there is no transformation (in
4225	>	* which case the action is not applied)
4226	>	* @param action the action
4227	>	* @param <U> the return type of the transformer
4228	>	* @since 1.8
4229	>	*/
4230	>	public <U> void forEachEntry(long parallelismThreshold,
4231	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4232	>	Consumer<? super U> action) {
4233	>	if (transformer == null || action == null)
4234	>	throw new NullPointerException();
4235	>	new ForEachTransformedEntryTask<K,V,U>
4236	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4237	>	transformer, action).invoke();
4238	>	}
4239	>
4240	>	/**
4241	>	* Returns a non-null result from applying the given search
4242	>	* function on each entry, or null if none.  Upon success,
4243	>	* further element processing is suppressed and the results of
4244	>	* any other parallel invocations of the search function are
4245	>	* ignored.
4246	>	*
4247	>	* @param parallelismThreshold the (estimated) number of elements
4248	>	* needed for this operation to be executed in parallel
4249	>	* @param searchFunction a function returning a non-null
4250	>	* result on success, else null
4251	>	* @param <U> the return type of the search function
4252	>	* @return a non-null result from applying the given search
4253	>	* function on each entry, or null if none
4254	>	* @since 1.8
4255	>	*/
4256	>	public <U> U searchEntries(long parallelismThreshold,
4257	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4258	>	if (searchFunction == null) throw new NullPointerException();
4259	>	return new SearchEntriesTask<K,V,U>
4260	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4261	>	searchFunction, new AtomicReference<U>()).invoke();
4262	>	}
4263	>
4264	>	/**
4265	>	* Returns the result of accumulating all entries using the
4266	>	* given reducer to combine values, or null if none.
4267	>	*
4268	>	* @param parallelismThreshold the (estimated) number of elements
4269	>	* needed for this operation to be executed in parallel
4270	>	* @param reducer a commutative associative combining function
4271	>	* @return the result of accumulating all entries
4272	>	* @since 1.8
4273	>	*/
4274	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4275	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4276	>	if (reducer == null) throw new NullPointerException();
4277	>	return new ReduceEntriesTask<K,V>
4278	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4279	>	null, reducer).invoke();
4280	>	}
4281	>
4282	>	/**
4283	>	* Returns the result of accumulating the given transformation
4284	>	* of all entries using the given reducer to combine values,
4285	>	* or null if none.
4286	>	*
4287	>	* @param parallelismThreshold the (estimated) number of elements
4288	>	* needed for this operation to be executed in parallel
4289	>	* @param transformer a function returning the transformation
4290	>	* for an element, or null if there is no transformation (in
4291	>	* which case it is not combined)
4292	>	* @param reducer a commutative associative combining function
4293	>	* @param <U> the return type of the transformer
4294	>	* @return the result of accumulating the given transformation
4295	>	* of all entries
4296	>	* @since 1.8
4297	>	*/
4298	>	public <U> U reduceEntries(long parallelismThreshold,
4299	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4300	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4301	>	if (transformer == null || reducer == null)
4302	>	throw new NullPointerException();
4303	>	return new MapReduceEntriesTask<K,V,U>
4304	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4305	>	null, transformer, reducer).invoke();
4306	>	}
4307	>
4308	>	/**
4309	>	* Returns the result of accumulating the given transformation
4310	>	* of all entries using the given reducer to combine values,
4311	>	* and the given basis as an identity value.
4312	>	*
4313	>	* @param parallelismThreshold the (estimated) number of elements
4314	>	* needed for this operation to be executed in parallel
4315	>	* @param transformer a function returning the transformation
4316	>	* for an element
4317	>	* @param basis the identity (initial default value) for the reduction
4318	>	* @param reducer a commutative associative combining function
4319	>	* @return the result of accumulating the given transformation
4320	>	* of all entries
4321	>	* @since 1.8
4322	>	*/
4323	>	public double reduceEntriesToDouble(long parallelismThreshold,
4324	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4325	>	double basis,
4326	>	DoubleBinaryOperator reducer) {
4327	>	if (transformer == null || reducer == null)
4328	>	throw new NullPointerException();
4329	>	return new MapReduceEntriesToDoubleTask<K,V>
4330	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4331	>	null, transformer, basis, reducer).invoke();
4332	>	}
4333	>
4334	>	/**
4335	>	* Returns the result of accumulating the given transformation
4336	>	* of all entries using the given reducer to combine values,
4337	>	* and the given basis as an identity value.
4338	>	*
4339	>	* @param parallelismThreshold the (estimated) number of elements
4340	>	* needed for this operation to be executed in parallel
4341	>	* @param transformer a function returning the transformation
4342	>	* for an element
4343	>	* @param basis the identity (initial default value) for the reduction
4344	>	* @param reducer a commutative associative combining function
4345	>	* @return the result of accumulating the given transformation
4346	>	* of all entries
4347	>	* @since 1.8
4348	>	*/
4349	>	public long reduceEntriesToLong(long parallelismThreshold,
4350	>	ToLongFunction<Map.Entry<K,V>> transformer,
4351	>	long basis,
4352	>	LongBinaryOperator reducer) {
4353	>	if (transformer == null || reducer == null)
4354	>	throw new NullPointerException();
4355	>	return new MapReduceEntriesToLongTask<K,V>
4356	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4357	>	null, transformer, basis, reducer).invoke();
4358	>	}
4359	>
4360	>	/**
4361	>	* Returns the result of accumulating the given transformation
4362	>	* of all entries using the given reducer to combine values,
4363	>	* and the given basis as an identity value.
4364	>	*
4365	>	* @param parallelismThreshold the (estimated) number of elements
4366	>	* needed for this operation to be executed in parallel
4367	>	* @param transformer a function returning the transformation
4368	>	* for an element
4369	>	* @param basis the identity (initial default value) for the reduction
4370	>	* @param reducer a commutative associative combining function
4371	>	* @return the result of accumulating the given transformation
4372	>	* of all entries
4373	>	* @since 1.8
4374	>	*/
4375	>	public int reduceEntriesToInt(long parallelismThreshold,
4376	>	ToIntFunction<Map.Entry<K,V>> transformer,
4377	>	int basis,
4378	>	IntBinaryOperator reducer) {
4379	>	if (transformer == null || reducer == null)
4380	>	throw new NullPointerException();
4381	>	return new MapReduceEntriesToIntTask<K,V>
4382	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4383	>	null, transformer, basis, reducer).invoke();
4384	>	}
4385	>
4386	>
4387	>	/* ----------------Views -------------- */
4388	>
4389	>	/**
4390	>	* Base class for views.
4391	>	*/
4392	>	abstract static class CollectionView<K,V,E>
4393	>	implements Collection<E>, java.io.Serializable {
4394	>	private static final long serialVersionUID = 7249069246763182397L;
4395	>	final ConcurrentHashMap<K,V> map;
4396	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4397	>
4398	>	/**
4399	>	* Returns the map backing this view.
4400	>	*
4401	>	* @return the map backing this view
4402	>	*/
4403	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4404	>
4405	>	/**
4406	>	* Removes all of the elements from this view, by removing all
4407	>	* the mappings from the map backing this view.
4408	>	*/
4409	>	public final void clear()      { map.clear(); }
4410	>	public final int size()        { return map.size(); }
4411	>	public final boolean isEmpty() { return map.isEmpty(); }
4412	>
4413	>	// implementations below rely on concrete classes supplying these
4414	>	// abstract methods
4415	>	/**
4416	>	* Returns an iterator over the elements in this collection.
4417	>	*
4418	>	* <p>The returned iterator is
4419	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4420	>	*
4421	>	* @return an iterator over the elements in this collection
4422	>	*/
4423	>	public abstract Iterator<E> iterator();
4424	>	public abstract boolean contains(Object o);
4425	>	public abstract boolean remove(Object o);
4426	>
4427	>	private static final String OOME_MSG = "Required array size too large";
4428	>
4429	>	public final Object[] toArray() {
4430	>	long sz = map.mappingCount();
4431	>	if (sz > MAX_ARRAY_SIZE)
4432	>	throw new OutOfMemoryError(OOME_MSG);
4433	>	int n = (int)sz;
4434	>	Object[] r = new Object[n];
4435	>	int i = 0;
4436	>	for (E e : this) {
4437	>	if (i == n) {
4438	>	if (n >= MAX_ARRAY_SIZE)
4439	>	throw new OutOfMemoryError(OOME_MSG);
4440	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4441	>	n = MAX_ARRAY_SIZE;
4442	>	else
4443	>	n += (n >>> 1) + 1;
4444	>	r = Arrays.copyOf(r, n);
4445	>	}
4446	>	r[i++] = e;
4447	>	}
4448	>	return (i == n) ? r : Arrays.copyOf(r, i);
4449		}
4450	<	public void clear() {
4451	<	ConcurrentHashMap.this.clear();
4450	>
4451	>	@SuppressWarnings("unchecked")
4452	>	public final <T> T[] toArray(T[] a) {
4453	>	long sz = map.mappingCount();
4454	>	if (sz > MAX_ARRAY_SIZE)
4455	>	throw new OutOfMemoryError(OOME_MSG);
4456	>	int m = (int)sz;
4457	>	T[] r = (a.length >= m) ? a :
4458	>	(T[])java.lang.reflect.Array
4459	>	.newInstance(a.getClass().getComponentType(), m);
4460	>	int n = r.length;
4461	>	int i = 0;
4462	>	for (E e : this) {
4463	>	if (i == n) {
4464	>	if (n >= MAX_ARRAY_SIZE)
4465	>	throw new OutOfMemoryError(OOME_MSG);
4466	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4467	>	n = MAX_ARRAY_SIZE;
4468	>	else
4469	>	n += (n >>> 1) + 1;
4470	>	r = Arrays.copyOf(r, n);
4471	>	}
4472	>	r[i++] = (T)e;
4473	>	}
4474	>	if (a == r && i < n) {
4475	>	r[i] = null; // null-terminate
4476	>	return r;
4477	>	}
4478	>	return (i == n) ? r : Arrays.copyOf(r, i);
4479		}
4480	+
4481	+	/**
4482	+	* Returns a string representation of this collection.
4483	+	* The string representation consists of the string representations
4484	+	* of the collection's elements in the order they are returned by
4485	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4486	+	* Adjacent elements are separated by the characters {@code ", "}
4487	+	* (comma and space).  Elements are converted to strings as by
4488	+	* {@link String#valueOf(Object)}.
4489	+	*
4490	+	* @return a string representation of this collection
4491	+	*/
4492	+	public final String toString() {
4493	+	StringBuilder sb = new StringBuilder();
4494	+	sb.append('[');
4495	+	Iterator<E> it = iterator();
4496	+	if (it.hasNext()) {
4497	+	for (;;) {
4498	+	Object e = it.next();
4499	+	sb.append(e == this ? "(this Collection)" : e);
4500	+	if (!it.hasNext())
4501	+	break;
4502	+	sb.append(',').append(' ');
4503	+	}
4504	+	}
4505	+	return sb.append(']').toString();
4506	+	}
4507	+
4508	+	public final boolean containsAll(Collection<?> c) {
4509	+	if (c != this) {
4510	+	for (Object e : c) {
4511	+	if (e == null || !contains(e))
4512	+	return false;
4513	+	}
4514	+	}
4515	+	return true;
4516	+	}
4517	+
4518	+	public boolean removeAll(Collection<?> c) {
4519	+	if (c == null) throw new NullPointerException();
4520	+	boolean modified = false;
4521	+	// Use (c instanceof Set) as a hint that lookup in c is as
4522	+	// efficient as this view
4523	+	Node<K,V>[] t;
4524	+	if ((t = map.table) == null) {
4525	+	return false;
4526	+	} else if (c instanceof Set<?> && c.size() > t.length) {
4527	+	for (Iterator<?> it = iterator(); it.hasNext(); ) {
4528	+	if (c.contains(it.next())) {
4529	+	it.remove();
4530	+	modified = true;
4531	+	}
4532	+	}
4533	+	} else {
4534	+	for (Object e : c)
4535	+	modified |= remove(e);
4536	+	}
4537	+	return modified;
4538	+	}
4539	+
4540	+	public final boolean retainAll(Collection<?> c) {
4541	+	if (c == null) throw new NullPointerException();
4542	+	boolean modified = false;
4543	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4544	+	if (!c.contains(it.next())) {
4545	+	it.remove();
4546	+	modified = true;
4547	+	}
4548	+	}
4549	+	return modified;
4550	+	}
4551	+
4552		}
4553
4554	<	final class Values extends AbstractCollection<V> {
4555	<	public Iterator<V> iterator() {
4556	<	return new ValueIterator();
4554	>	/**
4555	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4556	>	* which additions may optionally be enabled by mapping to a
4557	>	* common value.  This class cannot be directly instantiated.
4558	>	* See {@link #keySet() keySet()},
4559	>	* {@link #keySet(Object) keySet(V)},
4560	>	* {@link #newKeySet() newKeySet()},
4561	>	* {@link #newKeySet(int) newKeySet(int)}.
4562	>	*
4563	>	* @since 1.8
4564	>	*/
4565	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4566	>	implements Set<K>, java.io.Serializable {
4567	>	private static final long serialVersionUID = 7249069246763182397L;
4568	>	private final V value;
4569	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4570	>	super(map);
4571	>	this.value = value;
4572		}
4573	<	public int size() {
4574	<	return ConcurrentHashMap.this.size();
4573	>
4574	>	/**
4575	>	* Returns the default mapped value for additions,
4576	>	* or {@code null} if additions are not supported.
4577	>	*
4578	>	* @return the default mapped value for additions, or {@code null}
4579	>	* if not supported
4580	>	*/
4581	>	public V getMappedValue() { return value; }
4582	>
4583	>	/**
4584	>	* {@inheritDoc}
4585	>	* @throws NullPointerException if the specified key is null
4586	>	*/
4587	>	public boolean contains(Object o) { return map.containsKey(o); }
4588	>
4589	>	/**
4590	>	* Removes the key from this map view, by removing the key (and its
4591	>	* corresponding value) from the backing map.  This method does
4592	>	* nothing if the key is not in the map.
4593	>	*
4594	>	* @param  o the key to be removed from the backing map
4595	>	* @return {@code true} if the backing map contained the specified key
4596	>	* @throws NullPointerException if the specified key is null
4597	>	*/
4598	>	public boolean remove(Object o) { return map.remove(o) != null; }
4599	>
4600	>	/**
4601	>	* @return an iterator over the keys of the backing map
4602	>	*/
4603	>	public Iterator<K> iterator() {
4604	>	Node<K,V>[] t;
4605	>	ConcurrentHashMap<K,V> m = map;
4606	>	int f = (t = m.table) == null ? 0 : t.length;
4607	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4608		}
4609	<	public boolean isEmpty() {
4610	<	return ConcurrentHashMap.this.isEmpty();
4609	>
4610	>	/**
4611	>	* Adds the specified key to this set view by mapping the key to
4612	>	* the default mapped value in the backing map, if defined.
4613	>	*
4614	>	* @param e key to be added
4615	>	* @return {@code true} if this set changed as a result of the call
4616	>	* @throws NullPointerException if the specified key is null
4617	>	* @throws UnsupportedOperationException if no default mapped value
4618	>	* for additions was provided
4619	>	*/
4620	>	public boolean add(K e) {
4621	>	V v;
4622	>	if ((v = value) == null)
4623	>	throw new UnsupportedOperationException();
4624	>	return map.putVal(e, v, true) == null;
4625		}
4626	<	public boolean contains(Object o) {
4627	<	return ConcurrentHashMap.this.containsValue(o);
4626	>
4627	>	/**
4628	>	* Adds all of the elements in the specified collection to this set,
4629	>	* as if by calling {@link #add} on each one.
4630	>	*
4631	>	* @param c the elements to be inserted into this set
4632	>	* @return {@code true} if this set changed as a result of the call
4633	>	* @throws NullPointerException if the collection or any of its
4634	>	* elements are {@code null}
4635	>	* @throws UnsupportedOperationException if no default mapped value
4636	>	* for additions was provided
4637	>	*/
4638	>	public boolean addAll(Collection<? extends K> c) {
4639	>	boolean added = false;
4640	>	V v;
4641	>	if ((v = value) == null)
4642	>	throw new UnsupportedOperationException();
4643	>	for (K e : c) {
4644	>	if (map.putVal(e, v, true) == null)
4645	>	added = true;
4646	>	}
4647	>	return added;
4648		}
4649	<	public void clear() {
4650	<	ConcurrentHashMap.this.clear();
4649	>
4650	>	public int hashCode() {
4651	>	int h = 0;
4652	>	for (K e : this)
4653	>	h += e.hashCode();
4654	>	return h;
4655	>	}
4656	>
4657	>	public boolean equals(Object o) {
4658	>	Set<?> c;
4659	>	return ((o instanceof Set) &&
4660	>	((c = (Set<?>)o) == this ||
4661	>	(containsAll(c) && c.containsAll(this))));
4662	>	}
4663	>
4664	>	public Spliterator<K> spliterator() {
4665	>	Node<K,V>[] t;
4666	>	ConcurrentHashMap<K,V> m = map;
4667	>	long n = m.sumCount();
4668	>	int f = (t = m.table) == null ? 0 : t.length;
4669	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4670	>	}
4671	>
4672	>	public void forEach(Consumer<? super K> action) {
4673	>	if (action == null) throw new NullPointerException();
4674	>	Node<K,V>[] t;
4675	>	if ((t = map.table) != null) {
4676	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4677	>	for (Node<K,V> p; (p = it.advance()) != null; )
4678	>	action.accept(p.key);
4679	>	}
4680		}
4681		}
4682
4683	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4684	<	public Iterator<Map.Entry<K,V>> iterator() {
4685	<	return new EntryIterator();
4683	>	/**
4684	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4685	>	* values, in which additions are disabled. This class cannot be
4686	>	* directly instantiated. See {@link #values()}.
4687	>	*/
4688	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4689	>	implements Collection<V>, java.io.Serializable {
4690	>	private static final long serialVersionUID = 2249069246763182397L;
4691	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4692	>	public final boolean contains(Object o) {
4693	>	return map.containsValue(o);
4694		}
4695	+
4696	+	public final boolean remove(Object o) {
4697	+	if (o != null) {
4698	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4699	+	if (o.equals(it.next())) {
4700	+	it.remove();
4701	+	return true;
4702	+	}
4703	+	}
4704	+	}
4705	+	return false;
4706	+	}
4707	+
4708	+	public final Iterator<V> iterator() {
4709	+	ConcurrentHashMap<K,V> m = map;
4710	+	Node<K,V>[] t;
4711	+	int f = (t = m.table) == null ? 0 : t.length;
4712	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4713	+	}
4714	+
4715	+	public final boolean add(V e) {
4716	+	throw new UnsupportedOperationException();
4717	+	}
4718	+	public final boolean addAll(Collection<? extends V> c) {
4719	+	throw new UnsupportedOperationException();
4720	+	}
4721	+
4722	+	@Override public boolean removeAll(Collection<?> c) {
4723	+	if (c == null) throw new NullPointerException();
4724	+	boolean modified = false;
4725	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4726	+	if (c.contains(it.next())) {
4727	+	it.remove();
4728	+	modified = true;
4729	+	}
4730	+	}
4731	+	return modified;
4732	+	}
4733	+
4734	+	public boolean removeIf(Predicate<? super V> filter) {
4735	+	return map.removeValueIf(filter);
4736	+	}
4737	+
4738	+	public Spliterator<V> spliterator() {
4739	+	Node<K,V>[] t;
4740	+	ConcurrentHashMap<K,V> m = map;
4741	+	long n = m.sumCount();
4742	+	int f = (t = m.table) == null ? 0 : t.length;
4743	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4744	+	}
4745	+
4746	+	public void forEach(Consumer<? super V> action) {
4747	+	if (action == null) throw new NullPointerException();
4748	+	Node<K,V>[] t;
4749	+	if ((t = map.table) != null) {
4750	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4751	+	for (Node<K,V> p; (p = it.advance()) != null; )
4752	+	action.accept(p.val);
4753	+	}
4754	+	}
4755	+	}
4756	+
4757	+	/**
4758	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4759	+	* entries.  This class cannot be directly instantiated. See
4760	+	* {@link #entrySet()}.
4761	+	*/
4762	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4763	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4764	+	private static final long serialVersionUID = 2249069246763182397L;
4765	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4766	+
4767		public boolean contains(Object o) {
4768	<	if (!(o instanceof Map.Entry))
4769	<	return false;
4770	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4771	<	V v = ConcurrentHashMap.this.get(e.getKey());
4772	<	return v != null && v.equals(e.getValue());
4768	>	Object k, v, r; Map.Entry<?,?> e;
4769	>	return ((o instanceof Map.Entry) &&
4770	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4771	>	(r = map.get(k)) != null &&
4772	>	(v = e.getValue()) != null &&
4773	>	(v == r || v.equals(r)));
4774		}
4775	+
4776		public boolean remove(Object o) {
4777	<	if (!(o instanceof Map.Entry))
4778	<	return false;
4779	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4780	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4777	>	Object k, v; Map.Entry<?,?> e;
4778	>	return ((o instanceof Map.Entry) &&
4779	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4780	>	(v = e.getValue()) != null &&
4781	>	map.remove(k, v));
4782		}
4783	<	public int size() {
4784	<	return ConcurrentHashMap.this.size();
4783	>
4784	>	/**
4785	>	* @return an iterator over the entries of the backing map
4786	>	*/
4787	>	public Iterator<Map.Entry<K,V>> iterator() {
4788	>	ConcurrentHashMap<K,V> m = map;
4789	>	Node<K,V>[] t;
4790	>	int f = (t = m.table) == null ? 0 : t.length;
4791	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4792		}
4793	<	public boolean isEmpty() {
4794	<	return ConcurrentHashMap.this.isEmpty();
4793	>
4794	>	public boolean add(Entry<K,V> e) {
4795	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4796		}
4797	<	public void clear() {
4798	<	ConcurrentHashMap.this.clear();
4797	>
4798	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4799	>	boolean added = false;
4800	>	for (Entry<K,V> e : c) {
4801	>	if (add(e))
4802	>	added = true;
4803	>	}
4804	>	return added;
4805	>	}
4806	>
4807	>	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4808	>	return map.removeEntryIf(filter);
4809	>	}
4810	>
4811	>	public final int hashCode() {
4812	>	int h = 0;
4813	>	Node<K,V>[] t;
4814	>	if ((t = map.table) != null) {
4815	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4816	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4817	>	h += p.hashCode();
4818	>	}
4819	>	}
4820	>	return h;
4821	>	}
4822	>
4823	>	public final boolean equals(Object o) {
4824	>	Set<?> c;
4825	>	return ((o instanceof Set) &&
4826	>	((c = (Set<?>)o) == this ||
4827	>	(containsAll(c) && c.containsAll(this))));
4828	>	}
4829	>
4830	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4831	>	Node<K,V>[] t;
4832	>	ConcurrentHashMap<K,V> m = map;
4833	>	long n = m.sumCount();
4834	>	int f = (t = m.table) == null ? 0 : t.length;
4835	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4836	>	}
4837	>
4838	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4839	>	if (action == null) throw new NullPointerException();
4840	>	Node<K,V>[] t;
4841	>	if ((t = map.table) != null) {
4842	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4843	>	for (Node<K,V> p; (p = it.advance()) != null; )
4844	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4845	>	}
4846		}
4847	+
4848		}
4849
4850	<	/* ---------------- Serialization Support -------------- */
4850	>	// -------------------------------------------------------
4851
4852		/**
4853	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4854	<	* 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.
4853	>	* Base class for bulk tasks. Repeats some fields and code from
4854	>	* class Traverser, because we need to subclass CountedCompleter.
4855		*/
4856	<	private void writeObject(java.io.ObjectOutputStream s)
4857	<	throws java.io.IOException {
4858	<	// force all segments for serialization compatibility
4859	<	for (int k = 0; k < segments.length; ++k)
4860	<	ensureSegment(k);
4861	<	s.defaultWriteObject();
4862	<
4863	<	final Segment<K,V>[] segments = this.segments;
4864	<	for (int k = 0; k < segments.length; ++k) {
4865	<	Segment<K,V> seg = segmentAt(segments, k);
4866	<	seg.lock();
4867	<	try {
4868	<	HashEntry<K,V>[] tab = seg.table;
4869	<	for (int i = 0; i < tab.length; ++i) {
4870	<	HashEntry<K,V> e;
4871	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4872	<	s.writeObject(e.key);
4873	<	s.writeObject(e.value);
4856	>	@SuppressWarnings("serial")
4857	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4858	>	Node<K,V>[] tab;        // same as Traverser
4859	>	Node<K,V> next;
4860	>	TableStack<K,V> stack, spare;
4861	>	int index;
4862	>	int baseIndex;
4863	>	int baseLimit;
4864	>	final int baseSize;
4865	>	int batch;              // split control
4866	>
4867	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4868	>	super(par);
4869	>	this.batch = b;
4870	>	this.index = this.baseIndex = i;
4871	>	if ((this.tab = t) == null)
4872	>	this.baseSize = this.baseLimit = 0;
4873	>	else if (par == null)
4874	>	this.baseSize = this.baseLimit = t.length;
4875	>	else {
4876	>	this.baseLimit = f;
4877	>	this.baseSize = par.baseSize;
4878	>	}
4879	>	}
4880	>
4881	>	/**
4882	>	* Same as Traverser version.
4883	>	*/
4884	>	final Node<K,V> advance() {
4885	>	Node<K,V> e;
4886	>	if ((e = next) != null)
4887	>	e = e.next;
4888	>	for (;;) {
4889	>	Node<K,V>[] t; int i, n;
4890	>	if (e != null)
4891	>	return next = e;
4892	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4893	>	(n = t.length) <= (i = index) || i < 0)
4894	>	return next = null;
4895	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4896	>	if (e instanceof ForwardingNode) {
4897	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4898	>	e = null;
4899	>	pushState(t, i, n);
4900	>	continue;
4901		}
4902	+	else if (e instanceof TreeBin)
4903	+	e = ((TreeBin<K,V>)e).first;
4904	+	else
4905	+	e = null;
4906		}
4907	<	} finally {
4908	<	seg.unlock();
4907	>	if (stack != null)
4908	>	recoverState(n);
4909	>	else if ((index = i + baseSize) >= n)
4910	>	index = ++baseIndex;
4911		}
4912		}
4913	<	s.writeObject(null);
4914	<	s.writeObject(null);
4913	>
4914	>	private void pushState(Node<K,V>[] t, int i, int n) {
4915	>	TableStack<K,V> s = spare;
4916	>	if (s != null)
4917	>	spare = s.next;
4918	>	else
4919	>	s = new TableStack<K,V>();
4920	>	s.tab = t;
4921	>	s.length = n;
4922	>	s.index = i;
4923	>	s.next = stack;
4924	>	stack = s;
4925	>	}
4926	>
4927	>	private void recoverState(int n) {
4928	>	TableStack<K,V> s; int len;
4929	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4930	>	n = len;
4931	>	index = s.index;
4932	>	tab = s.tab;
4933	>	s.tab = null;
4934	>	TableStack<K,V> next = s.next;
4935	>	s.next = spare; // save for reuse
4936	>	stack = next;
4937	>	spare = s;
4938	>	}
4939	>	if (s == null && (index += baseSize) >= n)
4940	>	index = ++baseIndex;
4941	>	}
4942		}
4943
4944	<	/**
4945	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4946	<	* stream (i.e., deserializes it).
4947	<	* @param s the stream
4948	<	*/
4949	<	@SuppressWarnings("unchecked")
4950	<	private void readObject(java.io.ObjectInputStream s)
4951	<	throws java.io.IOException, ClassNotFoundException {
4952	<	s.defaultReadObject();
4944	>	/*
4945	>	* Task classes. Coded in a regular but ugly format/style to
4946	>	* simplify checks that each variant differs in the right way from
4947	>	* others. The null screenings exist because compilers cannot tell
4948	>	* that we've already null-checked task arguments, so we force
4949	>	* simplest hoisted bypass to help avoid convoluted traps.
4950	>	*/
4951	>	@SuppressWarnings("serial")
4952	>	static final class ForEachKeyTask<K,V>
4953	>	extends BulkTask<K,V,Void> {
4954	>	final Consumer<? super K> action;
4955	>	ForEachKeyTask
4956	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4957	>	Consumer<? super K> action) {
4958	>	super(p, b, i, f, t);
4959	>	this.action = action;
4960	>	}
4961	>	public final void compute() {
4962	>	final Consumer<? super K> action;
4963	>	if ((action = this.action) != null) {
4964	>	for (int i = baseIndex, f, h; batch > 0 &&
4965	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4966	>	addToPendingCount(1);
4967	>	new ForEachKeyTask<K,V>
4968	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4969	>	action).fork();
4970	>	}
4971	>	for (Node<K,V> p; (p = advance()) != null;)
4972	>	action.accept(p.key);
4973	>	propagateCompletion();
4974	>	}
4975	>	}
4976	>	}
4977
4978	<	// Re-initialize segments to be minimally sized, and let grow.
4979	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4980	<	final Segment<K,V>[] segments = this.segments;
4981	<	for (int k = 0; k < segments.length; ++k) {
4982	<	Segment<K,V> seg = segments[k];
4983	<	if (seg != null) {
4984	<	seg.threshold = (int)(cap * seg.loadFactor);
4985	<	seg.table = (HashEntry<K,V>[]) new HashEntry<?,?>[cap];
4978	>	@SuppressWarnings("serial")
4979	>	static final class ForEachValueTask<K,V>
4980	>	extends BulkTask<K,V,Void> {
4981	>	final Consumer<? super V> action;
4982	>	ForEachValueTask
4983	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4984	>	Consumer<? super V> action) {
4985	>	super(p, b, i, f, t);
4986	>	this.action = action;
4987	>	}
4988	>	public final void compute() {
4989	>	final Consumer<? super V> action;
4990	>	if ((action = this.action) != null) {
4991	>	for (int i = baseIndex, f, h; batch > 0 &&
4992	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4993	>	addToPendingCount(1);
4994	>	new ForEachValueTask<K,V>
4995	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4996	>	action).fork();
4997	>	}
4998	>	for (Node<K,V> p; (p = advance()) != null;)
4999	>	action.accept(p.val);
5000	>	propagateCompletion();
5001		}
5002		}
5003	+	}
5004
5005	<	// Read the keys and values, and put the mappings in the table
5006	<	for (;;) {
5007	<	K key = (K) s.readObject();
5008	<	V value = (V) s.readObject();
5009	<	if (key == null)
5010	<	break;
5011	<	put(key, value);
5005	>	@SuppressWarnings("serial")
5006	>	static final class ForEachEntryTask<K,V>
5007	>	extends BulkTask<K,V,Void> {
5008	>	final Consumer<? super Entry<K,V>> action;
5009	>	ForEachEntryTask
5010	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5011	>	Consumer<? super Entry<K,V>> action) {
5012	>	super(p, b, i, f, t);
5013	>	this.action = action;
5014	>	}
5015	>	public final void compute() {
5016	>	final Consumer<? super Entry<K,V>> action;
5017	>	if ((action = this.action) != null) {
5018	>	for (int i = baseIndex, f, h; batch > 0 &&
5019	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5020	>	addToPendingCount(1);
5021	>	new ForEachEntryTask<K,V>
5022	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5023	>	action).fork();
5024	>	}
5025	>	for (Node<K,V> p; (p = advance()) != null; )
5026	>	action.accept(p);
5027	>	propagateCompletion();
5028	>	}
5029	>	}
5030	>	}
5031	>
5032	>	@SuppressWarnings("serial")
5033	>	static final class ForEachMappingTask<K,V>
5034	>	extends BulkTask<K,V,Void> {
5035	>	final BiConsumer<? super K, ? super V> action;
5036	>	ForEachMappingTask
5037	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5038	>	BiConsumer<? super K,? super V> action) {
5039	>	super(p, b, i, f, t);
5040	>	this.action = action;
5041	>	}
5042	>	public final void compute() {
5043	>	final BiConsumer<? super K, ? super V> action;
5044	>	if ((action = this.action) != null) {
5045	>	for (int i = baseIndex, f, h; batch > 0 &&
5046	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5047	>	addToPendingCount(1);
5048	>	new ForEachMappingTask<K,V>
5049	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5050	>	action).fork();
5051	>	}
5052	>	for (Node<K,V> p; (p = advance()) != null; )
5053	>	action.accept(p.key, p.val);
5054	>	propagateCompletion();
5055	>	}
5056	>	}
5057	>	}
5058	>
5059	>	@SuppressWarnings("serial")
5060	>	static final class ForEachTransformedKeyTask<K,V,U>
5061	>	extends BulkTask<K,V,Void> {
5062	>	final Function<? super K, ? extends U> transformer;
5063	>	final Consumer<? super U> action;
5064	>	ForEachTransformedKeyTask
5065	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5066	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5067	>	super(p, b, i, f, t);
5068	>	this.transformer = transformer; this.action = action;
5069	>	}
5070	>	public final void compute() {
5071	>	final Function<? super K, ? extends U> transformer;
5072	>	final Consumer<? super U> action;
5073	>	if ((transformer = this.transformer) != null &&
5074	>	(action = this.action) != null) {
5075	>	for (int i = baseIndex, f, h; batch > 0 &&
5076	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5077	>	addToPendingCount(1);
5078	>	new ForEachTransformedKeyTask<K,V,U>
5079	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5080	>	transformer, action).fork();
5081	>	}
5082	>	for (Node<K,V> p; (p = advance()) != null; ) {
5083	>	U u;
5084	>	if ((u = transformer.apply(p.key)) != null)
5085	>	action.accept(u);
5086	>	}
5087	>	propagateCompletion();
5088	>	}
5089	>	}
5090	>	}
5091	>
5092	>	@SuppressWarnings("serial")
5093	>	static final class ForEachTransformedValueTask<K,V,U>
5094	>	extends BulkTask<K,V,Void> {
5095	>	final Function<? super V, ? extends U> transformer;
5096	>	final Consumer<? super U> action;
5097	>	ForEachTransformedValueTask
5098	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5099	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5100	>	super(p, b, i, f, t);
5101	>	this.transformer = transformer; this.action = action;
5102	>	}
5103	>	public final void compute() {
5104	>	final Function<? super V, ? extends U> transformer;
5105	>	final Consumer<? super U> action;
5106	>	if ((transformer = this.transformer) != null &&
5107	>	(action = this.action) != null) {
5108	>	for (int i = baseIndex, f, h; batch > 0 &&
5109	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5110	>	addToPendingCount(1);
5111	>	new ForEachTransformedValueTask<K,V,U>
5112	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5113	>	transformer, action).fork();
5114	>	}
5115	>	for (Node<K,V> p; (p = advance()) != null; ) {
5116	>	U u;
5117	>	if ((u = transformer.apply(p.val)) != null)
5118	>	action.accept(u);
5119	>	}
5120	>	propagateCompletion();
5121	>	}
5122	>	}
5123	>	}
5124	>
5125	>	@SuppressWarnings("serial")
5126	>	static final class ForEachTransformedEntryTask<K,V,U>
5127	>	extends BulkTask<K,V,Void> {
5128	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5129	>	final Consumer<? super U> action;
5130	>	ForEachTransformedEntryTask
5131	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5132	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5133	>	super(p, b, i, f, t);
5134	>	this.transformer = transformer; this.action = action;
5135	>	}
5136	>	public final void compute() {
5137	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5138	>	final Consumer<? super U> action;
5139	>	if ((transformer = this.transformer) != null &&
5140	>	(action = this.action) != null) {
5141	>	for (int i = baseIndex, f, h; batch > 0 &&
5142	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5143	>	addToPendingCount(1);
5144	>	new ForEachTransformedEntryTask<K,V,U>
5145	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5146	>	transformer, action).fork();
5147	>	}
5148	>	for (Node<K,V> p; (p = advance()) != null; ) {
5149	>	U u;
5150	>	if ((u = transformer.apply(p)) != null)
5151	>	action.accept(u);
5152	>	}
5153	>	propagateCompletion();
5154	>	}
5155	>	}
5156	>	}
5157	>
5158	>	@SuppressWarnings("serial")
5159	>	static final class ForEachTransformedMappingTask<K,V,U>
5160	>	extends BulkTask<K,V,Void> {
5161	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5162	>	final Consumer<? super U> action;
5163	>	ForEachTransformedMappingTask
5164	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5165	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5166	>	Consumer<? super U> action) {
5167	>	super(p, b, i, f, t);
5168	>	this.transformer = transformer; this.action = action;
5169	>	}
5170	>	public final void compute() {
5171	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5172	>	final Consumer<? super U> action;
5173	>	if ((transformer = this.transformer) != null &&
5174	>	(action = this.action) != null) {
5175	>	for (int i = baseIndex, f, h; batch > 0 &&
5176	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5177	>	addToPendingCount(1);
5178	>	new ForEachTransformedMappingTask<K,V,U>
5179	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5180	>	transformer, action).fork();
5181	>	}
5182	>	for (Node<K,V> p; (p = advance()) != null; ) {
5183	>	U u;
5184	>	if ((u = transformer.apply(p.key, p.val)) != null)
5185	>	action.accept(u);
5186	>	}
5187	>	propagateCompletion();
5188	>	}
5189	>	}
5190	>	}
5191	>
5192	>	@SuppressWarnings("serial")
5193	>	static final class SearchKeysTask<K,V,U>
5194	>	extends BulkTask<K,V,U> {
5195	>	final Function<? super K, ? extends U> searchFunction;
5196	>	final AtomicReference<U> result;
5197	>	SearchKeysTask
5198	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5199	>	Function<? super K, ? extends U> searchFunction,
5200	>	AtomicReference<U> result) {
5201	>	super(p, b, i, f, t);
5202	>	this.searchFunction = searchFunction; this.result = result;
5203	>	}
5204	>	public final U getRawResult() { return result.get(); }
5205	>	public final void compute() {
5206	>	final Function<? super K, ? extends U> searchFunction;
5207	>	final AtomicReference<U> result;
5208	>	if ((searchFunction = this.searchFunction) != null &&
5209	>	(result = this.result) != null) {
5210	>	for (int i = baseIndex, f, h; batch > 0 &&
5211	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5212	>	if (result.get() != null)
5213	>	return;
5214	>	addToPendingCount(1);
5215	>	new SearchKeysTask<K,V,U>
5216	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5217	>	searchFunction, result).fork();
5218	>	}
5219	>	while (result.get() == null) {
5220	>	U u;
5221	>	Node<K,V> p;
5222	>	if ((p = advance()) == null) {
5223	>	propagateCompletion();
5224	>	break;
5225	>	}
5226	>	if ((u = searchFunction.apply(p.key)) != null) {
5227	>	if (result.compareAndSet(null, u))
5228	>	quietlyCompleteRoot();
5229	>	break;
5230	>	}
5231	>	}
5232	>	}
5233	>	}
5234	>	}
5235	>
5236	>	@SuppressWarnings("serial")
5237	>	static final class SearchValuesTask<K,V,U>
5238	>	extends BulkTask<K,V,U> {
5239	>	final Function<? super V, ? extends U> searchFunction;
5240	>	final AtomicReference<U> result;
5241	>	SearchValuesTask
5242	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5243	>	Function<? super V, ? extends U> searchFunction,
5244	>	AtomicReference<U> result) {
5245	>	super(p, b, i, f, t);
5246	>	this.searchFunction = searchFunction; this.result = result;
5247	>	}
5248	>	public final U getRawResult() { return result.get(); }
5249	>	public final void compute() {
5250	>	final Function<? super V, ? extends U> searchFunction;
5251	>	final AtomicReference<U> result;
5252	>	if ((searchFunction = this.searchFunction) != null &&
5253	>	(result = this.result) != null) {
5254	>	for (int i = baseIndex, f, h; batch > 0 &&
5255	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5256	>	if (result.get() != null)
5257	>	return;
5258	>	addToPendingCount(1);
5259	>	new SearchValuesTask<K,V,U>
5260	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5261	>	searchFunction, result).fork();
5262	>	}
5263	>	while (result.get() == null) {
5264	>	U u;
5265	>	Node<K,V> p;
5266	>	if ((p = advance()) == null) {
5267	>	propagateCompletion();
5268	>	break;
5269	>	}
5270	>	if ((u = searchFunction.apply(p.val)) != null) {
5271	>	if (result.compareAndSet(null, u))
5272	>	quietlyCompleteRoot();
5273	>	break;
5274	>	}
5275	>	}
5276	>	}
5277	>	}
5278	>	}
5279	>
5280	>	@SuppressWarnings("serial")
5281	>	static final class SearchEntriesTask<K,V,U>
5282	>	extends BulkTask<K,V,U> {
5283	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5284	>	final AtomicReference<U> result;
5285	>	SearchEntriesTask
5286	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5287	>	Function<Entry<K,V>, ? extends U> searchFunction,
5288	>	AtomicReference<U> result) {
5289	>	super(p, b, i, f, t);
5290	>	this.searchFunction = searchFunction; this.result = result;
5291	>	}
5292	>	public final U getRawResult() { return result.get(); }
5293	>	public final void compute() {
5294	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5295	>	final AtomicReference<U> result;
5296	>	if ((searchFunction = this.searchFunction) != null &&
5297	>	(result = this.result) != null) {
5298	>	for (int i = baseIndex, f, h; batch > 0 &&
5299	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5300	>	if (result.get() != null)
5301	>	return;
5302	>	addToPendingCount(1);
5303	>	new SearchEntriesTask<K,V,U>
5304	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5305	>	searchFunction, result).fork();
5306	>	}
5307	>	while (result.get() == null) {
5308	>	U u;
5309	>	Node<K,V> p;
5310	>	if ((p = advance()) == null) {
5311	>	propagateCompletion();
5312	>	break;
5313	>	}
5314	>	if ((u = searchFunction.apply(p)) != null) {
5315	>	if (result.compareAndSet(null, u))
5316	>	quietlyCompleteRoot();
5317	>	return;
5318	>	}
5319	>	}
5320	>	}
5321	>	}
5322	>	}
5323	>
5324	>	@SuppressWarnings("serial")
5325	>	static final class SearchMappingsTask<K,V,U>
5326	>	extends BulkTask<K,V,U> {
5327	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5328	>	final AtomicReference<U> result;
5329	>	SearchMappingsTask
5330	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5331	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5332	>	AtomicReference<U> result) {
5333	>	super(p, b, i, f, t);
5334	>	this.searchFunction = searchFunction; this.result = result;
5335	>	}
5336	>	public final U getRawResult() { return result.get(); }
5337	>	public final void compute() {
5338	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5339	>	final AtomicReference<U> result;
5340	>	if ((searchFunction = this.searchFunction) != null &&
5341	>	(result = this.result) != null) {
5342	>	for (int i = baseIndex, f, h; batch > 0 &&
5343	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5344	>	if (result.get() != null)
5345	>	return;
5346	>	addToPendingCount(1);
5347	>	new SearchMappingsTask<K,V,U>
5348	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5349	>	searchFunction, result).fork();
5350	>	}
5351	>	while (result.get() == null) {
5352	>	U u;
5353	>	Node<K,V> p;
5354	>	if ((p = advance()) == null) {
5355	>	propagateCompletion();
5356	>	break;
5357	>	}
5358	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5359	>	if (result.compareAndSet(null, u))
5360	>	quietlyCompleteRoot();
5361	>	break;
5362	>	}
5363	>	}
5364	>	}
5365	>	}
5366	>	}
5367	>
5368	>	@SuppressWarnings("serial")
5369	>	static final class ReduceKeysTask<K,V>
5370	>	extends BulkTask<K,V,K> {
5371	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5372	>	K result;
5373	>	ReduceKeysTask<K,V> rights, nextRight;
5374	>	ReduceKeysTask
5375	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5376	>	ReduceKeysTask<K,V> nextRight,
5377	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5378	>	super(p, b, i, f, t); this.nextRight = nextRight;
5379	>	this.reducer = reducer;
5380	>	}
5381	>	public final K getRawResult() { return result; }
5382	>	public final void compute() {
5383	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5384	>	if ((reducer = this.reducer) != null) {
5385	>	for (int i = baseIndex, f, h; batch > 0 &&
5386	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5387	>	addToPendingCount(1);
5388	>	(rights = new ReduceKeysTask<K,V>
5389	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5390	>	rights, reducer)).fork();
5391	>	}
5392	>	K r = null;
5393	>	for (Node<K,V> p; (p = advance()) != null; ) {
5394	>	K u = p.key;
5395	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5396	>	}
5397	>	result = r;
5398	>	CountedCompleter<?> c;
5399	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5400	>	@SuppressWarnings("unchecked")
5401	>	ReduceKeysTask<K,V>
5402	>	t = (ReduceKeysTask<K,V>)c,
5403	>	s = t.rights;
5404	>	while (s != null) {
5405	>	K tr, sr;
5406	>	if ((sr = s.result) != null)
5407	>	t.result = (((tr = t.result) == null) ? sr :
5408	>	reducer.apply(tr, sr));
5409	>	s = t.rights = s.nextRight;
5410	>	}
5411	>	}
5412	>	}
5413	>	}
5414	>	}
5415	>
5416	>	@SuppressWarnings("serial")
5417	>	static final class ReduceValuesTask<K,V>
5418	>	extends BulkTask<K,V,V> {
5419	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5420	>	V result;
5421	>	ReduceValuesTask<K,V> rights, nextRight;
5422	>	ReduceValuesTask
5423	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5424	>	ReduceValuesTask<K,V> nextRight,
5425	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5426	>	super(p, b, i, f, t); this.nextRight = nextRight;
5427	>	this.reducer = reducer;
5428	>	}
5429	>	public final V getRawResult() { return result; }
5430	>	public final void compute() {
5431	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5432	>	if ((reducer = this.reducer) != null) {
5433	>	for (int i = baseIndex, f, h; batch > 0 &&
5434	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5435	>	addToPendingCount(1);
5436	>	(rights = new ReduceValuesTask<K,V>
5437	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5438	>	rights, reducer)).fork();
5439	>	}
5440	>	V r = null;
5441	>	for (Node<K,V> p; (p = advance()) != null; ) {
5442	>	V v = p.val;
5443	>	r = (r == null) ? v : reducer.apply(r, v);
5444	>	}
5445	>	result = r;
5446	>	CountedCompleter<?> c;
5447	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5448	>	@SuppressWarnings("unchecked")
5449	>	ReduceValuesTask<K,V>
5450	>	t = (ReduceValuesTask<K,V>)c,
5451	>	s = t.rights;
5452	>	while (s != null) {
5453	>	V tr, sr;
5454	>	if ((sr = s.result) != null)
5455	>	t.result = (((tr = t.result) == null) ? sr :
5456	>	reducer.apply(tr, sr));
5457	>	s = t.rights = s.nextRight;
5458	>	}
5459	>	}
5460	>	}
5461	>	}
5462	>	}
5463	>
5464	>	@SuppressWarnings("serial")
5465	>	static final class ReduceEntriesTask<K,V>
5466	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5467	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5468	>	Map.Entry<K,V> result;
5469	>	ReduceEntriesTask<K,V> rights, nextRight;
5470	>	ReduceEntriesTask
5471	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5472	>	ReduceEntriesTask<K,V> nextRight,
5473	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5474	>	super(p, b, i, f, t); this.nextRight = nextRight;
5475	>	this.reducer = reducer;
5476	>	}
5477	>	public final Map.Entry<K,V> getRawResult() { return result; }
5478	>	public final void compute() {
5479	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5480	>	if ((reducer = this.reducer) != null) {
5481	>	for (int i = baseIndex, f, h; batch > 0 &&
5482	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5483	>	addToPendingCount(1);
5484	>	(rights = new ReduceEntriesTask<K,V>
5485	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5486	>	rights, reducer)).fork();
5487	>	}
5488	>	Map.Entry<K,V> r = null;
5489	>	for (Node<K,V> p; (p = advance()) != null; )
5490	>	r = (r == null) ? p : reducer.apply(r, p);
5491	>	result = r;
5492	>	CountedCompleter<?> c;
5493	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5494	>	@SuppressWarnings("unchecked")
5495	>	ReduceEntriesTask<K,V>
5496	>	t = (ReduceEntriesTask<K,V>)c,
5497	>	s = t.rights;
5498	>	while (s != null) {
5499	>	Map.Entry<K,V> tr, sr;
5500	>	if ((sr = s.result) != null)
5501	>	t.result = (((tr = t.result) == null) ? sr :
5502	>	reducer.apply(tr, sr));
5503	>	s = t.rights = s.nextRight;
5504	>	}
5505	>	}
5506	>	}
5507	>	}
5508	>	}
5509	>
5510	>	@SuppressWarnings("serial")
5511	>	static final class MapReduceKeysTask<K,V,U>
5512	>	extends BulkTask<K,V,U> {
5513	>	final Function<? super K, ? extends U> transformer;
5514	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5515	>	U result;
5516	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5517	>	MapReduceKeysTask
5518	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5519	>	MapReduceKeysTask<K,V,U> nextRight,
5520	>	Function<? super K, ? extends U> transformer,
5521	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5522	>	super(p, b, i, f, t); this.nextRight = nextRight;
5523	>	this.transformer = transformer;
5524	>	this.reducer = reducer;
5525	>	}
5526	>	public final U getRawResult() { return result; }
5527	>	public final void compute() {
5528	>	final Function<? super K, ? extends U> transformer;
5529	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5530	>	if ((transformer = this.transformer) != null &&
5531	>	(reducer = this.reducer) != null) {
5532	>	for (int i = baseIndex, f, h; batch > 0 &&
5533	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5534	>	addToPendingCount(1);
5535	>	(rights = new MapReduceKeysTask<K,V,U>
5536	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5537	>	rights, transformer, reducer)).fork();
5538	>	}
5539	>	U r = null;
5540	>	for (Node<K,V> p; (p = advance()) != null; ) {
5541	>	U u;
5542	>	if ((u = transformer.apply(p.key)) != null)
5543	>	r = (r == null) ? u : reducer.apply(r, u);
5544	>	}
5545	>	result = r;
5546	>	CountedCompleter<?> c;
5547	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5548	>	@SuppressWarnings("unchecked")
5549	>	MapReduceKeysTask<K,V,U>
5550	>	t = (MapReduceKeysTask<K,V,U>)c,
5551	>	s = t.rights;
5552	>	while (s != null) {
5553	>	U tr, sr;
5554	>	if ((sr = s.result) != null)
5555	>	t.result = (((tr = t.result) == null) ? sr :
5556	>	reducer.apply(tr, sr));
5557	>	s = t.rights = s.nextRight;
5558	>	}
5559	>	}
5560	>	}
5561	>	}
5562	>	}
5563	>
5564	>	@SuppressWarnings("serial")
5565	>	static final class MapReduceValuesTask<K,V,U>
5566	>	extends BulkTask<K,V,U> {
5567	>	final Function<? super V, ? extends U> transformer;
5568	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5569	>	U result;
5570	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5571	>	MapReduceValuesTask
5572	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5573	>	MapReduceValuesTask<K,V,U> nextRight,
5574	>	Function<? super V, ? extends U> transformer,
5575	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5576	>	super(p, b, i, f, t); this.nextRight = nextRight;
5577	>	this.transformer = transformer;
5578	>	this.reducer = reducer;
5579	>	}
5580	>	public final U getRawResult() { return result; }
5581	>	public final void compute() {
5582	>	final Function<? super V, ? extends U> transformer;
5583	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5584	>	if ((transformer = this.transformer) != null &&
5585	>	(reducer = this.reducer) != null) {
5586	>	for (int i = baseIndex, f, h; batch > 0 &&
5587	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5588	>	addToPendingCount(1);
5589	>	(rights = new MapReduceValuesTask<K,V,U>
5590	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5591	>	rights, transformer, reducer)).fork();
5592	>	}
5593	>	U r = null;
5594	>	for (Node<K,V> p; (p = advance()) != null; ) {
5595	>	U u;
5596	>	if ((u = transformer.apply(p.val)) != null)
5597	>	r = (r == null) ? u : reducer.apply(r, u);
5598	>	}
5599	>	result = r;
5600	>	CountedCompleter<?> c;
5601	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5602	>	@SuppressWarnings("unchecked")
5603	>	MapReduceValuesTask<K,V,U>
5604	>	t = (MapReduceValuesTask<K,V,U>)c,
5605	>	s = t.rights;
5606	>	while (s != null) {
5607	>	U tr, sr;
5608	>	if ((sr = s.result) != null)
5609	>	t.result = (((tr = t.result) == null) ? sr :
5610	>	reducer.apply(tr, sr));
5611	>	s = t.rights = s.nextRight;
5612	>	}
5613	>	}
5614	>	}
5615	>	}
5616	>	}
5617	>
5618	>	@SuppressWarnings("serial")
5619	>	static final class MapReduceEntriesTask<K,V,U>
5620	>	extends BulkTask<K,V,U> {
5621	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5622	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5623	>	U result;
5624	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5625	>	MapReduceEntriesTask
5626	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5627	>	MapReduceEntriesTask<K,V,U> nextRight,
5628	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5629	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5630	>	super(p, b, i, f, t); this.nextRight = nextRight;
5631	>	this.transformer = transformer;
5632	>	this.reducer = reducer;
5633	>	}
5634	>	public final U getRawResult() { return result; }
5635	>	public final void compute() {
5636	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5637	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5638	>	if ((transformer = this.transformer) != null &&
5639	>	(reducer = this.reducer) != null) {
5640	>	for (int i = baseIndex, f, h; batch > 0 &&
5641	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5642	>	addToPendingCount(1);
5643	>	(rights = new MapReduceEntriesTask<K,V,U>
5644	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5645	>	rights, transformer, reducer)).fork();
5646	>	}
5647	>	U r = null;
5648	>	for (Node<K,V> p; (p = advance()) != null; ) {
5649	>	U u;
5650	>	if ((u = transformer.apply(p)) != null)
5651	>	r = (r == null) ? u : reducer.apply(r, u);
5652	>	}
5653	>	result = r;
5654	>	CountedCompleter<?> c;
5655	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5656	>	@SuppressWarnings("unchecked")
5657	>	MapReduceEntriesTask<K,V,U>
5658	>	t = (MapReduceEntriesTask<K,V,U>)c,
5659	>	s = t.rights;
5660	>	while (s != null) {
5661	>	U tr, sr;
5662	>	if ((sr = s.result) != null)
5663	>	t.result = (((tr = t.result) == null) ? sr :
5664	>	reducer.apply(tr, sr));
5665	>	s = t.rights = s.nextRight;
5666	>	}
5667	>	}
5668	>	}
5669	>	}
5670	>	}
5671	>
5672	>	@SuppressWarnings("serial")
5673	>	static final class MapReduceMappingsTask<K,V,U>
5674	>	extends BulkTask<K,V,U> {
5675	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5676	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5677	>	U result;
5678	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5679	>	MapReduceMappingsTask
5680	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5681	>	MapReduceMappingsTask<K,V,U> nextRight,
5682	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5683	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5684	>	super(p, b, i, f, t); this.nextRight = nextRight;
5685	>	this.transformer = transformer;
5686	>	this.reducer = reducer;
5687	>	}
5688	>	public final U getRawResult() { return result; }
5689	>	public final void compute() {
5690	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5691	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5692	>	if ((transformer = this.transformer) != null &&
5693	>	(reducer = this.reducer) != null) {
5694	>	for (int i = baseIndex, f, h; batch > 0 &&
5695	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5696	>	addToPendingCount(1);
5697	>	(rights = new MapReduceMappingsTask<K,V,U>
5698	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5699	>	rights, transformer, reducer)).fork();
5700	>	}
5701	>	U r = null;
5702	>	for (Node<K,V> p; (p = advance()) != null; ) {
5703	>	U u;
5704	>	if ((u = transformer.apply(p.key, p.val)) != null)
5705	>	r = (r == null) ? u : reducer.apply(r, u);
5706	>	}
5707	>	result = r;
5708	>	CountedCompleter<?> c;
5709	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5710	>	@SuppressWarnings("unchecked")
5711	>	MapReduceMappingsTask<K,V,U>
5712	>	t = (MapReduceMappingsTask<K,V,U>)c,
5713	>	s = t.rights;
5714	>	while (s != null) {
5715	>	U tr, sr;
5716	>	if ((sr = s.result) != null)
5717	>	t.result = (((tr = t.result) == null) ? sr :
5718	>	reducer.apply(tr, sr));
5719	>	s = t.rights = s.nextRight;
5720	>	}
5721	>	}
5722	>	}
5723	>	}
5724	>	}
5725	>
5726	>	@SuppressWarnings("serial")
5727	>	static final class MapReduceKeysToDoubleTask<K,V>
5728	>	extends BulkTask<K,V,Double> {
5729	>	final ToDoubleFunction<? super K> transformer;
5730	>	final DoubleBinaryOperator reducer;
5731	>	final double basis;
5732	>	double result;
5733	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5734	>	MapReduceKeysToDoubleTask
5735	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5736	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5737	>	ToDoubleFunction<? super K> transformer,
5738	>	double basis,
5739	>	DoubleBinaryOperator reducer) {
5740	>	super(p, b, i, f, t); this.nextRight = nextRight;
5741	>	this.transformer = transformer;
5742	>	this.basis = basis; this.reducer = reducer;
5743	>	}
5744	>	public final Double getRawResult() { return result; }
5745	>	public final void compute() {
5746	>	final ToDoubleFunction<? super K> transformer;
5747	>	final DoubleBinaryOperator reducer;
5748	>	if ((transformer = this.transformer) != null &&
5749	>	(reducer = this.reducer) != null) {
5750	>	double r = this.basis;
5751	>	for (int i = baseIndex, f, h; batch > 0 &&
5752	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5753	>	addToPendingCount(1);
5754	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5755	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5756	>	rights, transformer, r, reducer)).fork();
5757	>	}
5758	>	for (Node<K,V> p; (p = advance()) != null; )
5759	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5760	>	result = r;
5761	>	CountedCompleter<?> c;
5762	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5763	>	@SuppressWarnings("unchecked")
5764	>	MapReduceKeysToDoubleTask<K,V>
5765	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5766	>	s = t.rights;
5767	>	while (s != null) {
5768	>	t.result = reducer.applyAsDouble(t.result, s.result);
5769	>	s = t.rights = s.nextRight;
5770	>	}
5771	>	}
5772	>	}
5773	>	}
5774	>	}
5775	>
5776	>	@SuppressWarnings("serial")
5777	>	static final class MapReduceValuesToDoubleTask<K,V>
5778	>	extends BulkTask<K,V,Double> {
5779	>	final ToDoubleFunction<? super V> transformer;
5780	>	final DoubleBinaryOperator reducer;
5781	>	final double basis;
5782	>	double result;
5783	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5784	>	MapReduceValuesToDoubleTask
5785	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5786	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5787	>	ToDoubleFunction<? super V> transformer,
5788	>	double basis,
5789	>	DoubleBinaryOperator reducer) {
5790	>	super(p, b, i, f, t); this.nextRight = nextRight;
5791	>	this.transformer = transformer;
5792	>	this.basis = basis; this.reducer = reducer;
5793	>	}
5794	>	public final Double getRawResult() { return result; }
5795	>	public final void compute() {
5796	>	final ToDoubleFunction<? super V> transformer;
5797	>	final DoubleBinaryOperator reducer;
5798	>	if ((transformer = this.transformer) != null &&
5799	>	(reducer = this.reducer) != null) {
5800	>	double r = this.basis;
5801	>	for (int i = baseIndex, f, h; batch > 0 &&
5802	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5803	>	addToPendingCount(1);
5804	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5805	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5806	>	rights, transformer, r, reducer)).fork();
5807	>	}
5808	>	for (Node<K,V> p; (p = advance()) != null; )
5809	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5810	>	result = r;
5811	>	CountedCompleter<?> c;
5812	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5813	>	@SuppressWarnings("unchecked")
5814	>	MapReduceValuesToDoubleTask<K,V>
5815	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5816	>	s = t.rights;
5817	>	while (s != null) {
5818	>	t.result = reducer.applyAsDouble(t.result, s.result);
5819	>	s = t.rights = s.nextRight;
5820	>	}
5821	>	}
5822	>	}
5823	>	}
5824	>	}
5825	>
5826	>	@SuppressWarnings("serial")
5827	>	static final class MapReduceEntriesToDoubleTask<K,V>
5828	>	extends BulkTask<K,V,Double> {
5829	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5830	>	final DoubleBinaryOperator reducer;
5831	>	final double basis;
5832	>	double result;
5833	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5834	>	MapReduceEntriesToDoubleTask
5835	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5836	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5837	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5838	>	double basis,
5839	>	DoubleBinaryOperator reducer) {
5840	>	super(p, b, i, f, t); this.nextRight = nextRight;
5841	>	this.transformer = transformer;
5842	>	this.basis = basis; this.reducer = reducer;
5843	>	}
5844	>	public final Double getRawResult() { return result; }
5845	>	public final void compute() {
5846	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5847	>	final DoubleBinaryOperator reducer;
5848	>	if ((transformer = this.transformer) != null &&
5849	>	(reducer = this.reducer) != null) {
5850	>	double r = this.basis;
5851	>	for (int i = baseIndex, f, h; batch > 0 &&
5852	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5853	>	addToPendingCount(1);
5854	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5855	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5856	>	rights, transformer, r, reducer)).fork();
5857	>	}
5858	>	for (Node<K,V> p; (p = advance()) != null; )
5859	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5860	>	result = r;
5861	>	CountedCompleter<?> c;
5862	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5863	>	@SuppressWarnings("unchecked")
5864	>	MapReduceEntriesToDoubleTask<K,V>
5865	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5866	>	s = t.rights;
5867	>	while (s != null) {
5868	>	t.result = reducer.applyAsDouble(t.result, s.result);
5869	>	s = t.rights = s.nextRight;
5870	>	}
5871	>	}
5872	>	}
5873	>	}
5874	>	}
5875	>
5876	>	@SuppressWarnings("serial")
5877	>	static final class MapReduceMappingsToDoubleTask<K,V>
5878	>	extends BulkTask<K,V,Double> {
5879	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5880	>	final DoubleBinaryOperator reducer;
5881	>	final double basis;
5882	>	double result;
5883	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5884	>	MapReduceMappingsToDoubleTask
5885	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5886	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5887	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5888	>	double basis,
5889	>	DoubleBinaryOperator reducer) {
5890	>	super(p, b, i, f, t); this.nextRight = nextRight;
5891	>	this.transformer = transformer;
5892	>	this.basis = basis; this.reducer = reducer;
5893	>	}
5894	>	public final Double getRawResult() { return result; }
5895	>	public final void compute() {
5896	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5897	>	final DoubleBinaryOperator reducer;
5898	>	if ((transformer = this.transformer) != null &&
5899	>	(reducer = this.reducer) != null) {
5900	>	double r = this.basis;
5901	>	for (int i = baseIndex, f, h; batch > 0 &&
5902	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5903	>	addToPendingCount(1);
5904	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5905	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5906	>	rights, transformer, r, reducer)).fork();
5907	>	}
5908	>	for (Node<K,V> p; (p = advance()) != null; )
5909	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5910	>	result = r;
5911	>	CountedCompleter<?> c;
5912	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5913	>	@SuppressWarnings("unchecked")
5914	>	MapReduceMappingsToDoubleTask<K,V>
5915	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5916	>	s = t.rights;
5917	>	while (s != null) {
5918	>	t.result = reducer.applyAsDouble(t.result, s.result);
5919	>	s = t.rights = s.nextRight;
5920	>	}
5921	>	}
5922	>	}
5923	>	}
5924	>	}
5925	>
5926	>	@SuppressWarnings("serial")
5927	>	static final class MapReduceKeysToLongTask<K,V>
5928	>	extends BulkTask<K,V,Long> {
5929	>	final ToLongFunction<? super K> transformer;
5930	>	final LongBinaryOperator reducer;
5931	>	final long basis;
5932	>	long result;
5933	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5934	>	MapReduceKeysToLongTask
5935	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5936	>	MapReduceKeysToLongTask<K,V> nextRight,
5937	>	ToLongFunction<? super K> transformer,
5938	>	long basis,
5939	>	LongBinaryOperator reducer) {
5940	>	super(p, b, i, f, t); this.nextRight = nextRight;
5941	>	this.transformer = transformer;
5942	>	this.basis = basis; this.reducer = reducer;
5943	>	}
5944	>	public final Long getRawResult() { return result; }
5945	>	public final void compute() {
5946	>	final ToLongFunction<? super K> transformer;
5947	>	final LongBinaryOperator reducer;
5948	>	if ((transformer = this.transformer) != null &&
5949	>	(reducer = this.reducer) != null) {
5950	>	long r = this.basis;
5951	>	for (int i = baseIndex, f, h; batch > 0 &&
5952	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5953	>	addToPendingCount(1);
5954	>	(rights = new MapReduceKeysToLongTask<K,V>
5955	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5956	>	rights, transformer, r, reducer)).fork();
5957	>	}
5958	>	for (Node<K,V> p; (p = advance()) != null; )
5959	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5960	>	result = r;
5961	>	CountedCompleter<?> c;
5962	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5963	>	@SuppressWarnings("unchecked")
5964	>	MapReduceKeysToLongTask<K,V>
5965	>	t = (MapReduceKeysToLongTask<K,V>)c,
5966	>	s = t.rights;
5967	>	while (s != null) {
5968	>	t.result = reducer.applyAsLong(t.result, s.result);
5969	>	s = t.rights = s.nextRight;
5970	>	}
5971	>	}
5972	>	}
5973	>	}
5974	>	}
5975	>
5976	>	@SuppressWarnings("serial")
5977	>	static final class MapReduceValuesToLongTask<K,V>
5978	>	extends BulkTask<K,V,Long> {
5979	>	final ToLongFunction<? super V> transformer;
5980	>	final LongBinaryOperator reducer;
5981	>	final long basis;
5982	>	long result;
5983	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5984	>	MapReduceValuesToLongTask
5985	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5986	>	MapReduceValuesToLongTask<K,V> nextRight,
5987	>	ToLongFunction<? super V> transformer,
5988	>	long basis,
5989	>	LongBinaryOperator reducer) {
5990	>	super(p, b, i, f, t); this.nextRight = nextRight;
5991	>	this.transformer = transformer;
5992	>	this.basis = basis; this.reducer = reducer;
5993	>	}
5994	>	public final Long getRawResult() { return result; }
5995	>	public final void compute() {
5996	>	final ToLongFunction<? super V> transformer;
5997	>	final LongBinaryOperator reducer;
5998	>	if ((transformer = this.transformer) != null &&
5999	>	(reducer = this.reducer) != null) {
6000	>	long r = this.basis;
6001	>	for (int i = baseIndex, f, h; batch > 0 &&
6002	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6003	>	addToPendingCount(1);
6004	>	(rights = new MapReduceValuesToLongTask<K,V>
6005	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6006	>	rights, transformer, r, reducer)).fork();
6007	>	}
6008	>	for (Node<K,V> p; (p = advance()) != null; )
6009	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
6010	>	result = r;
6011	>	CountedCompleter<?> c;
6012	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6013	>	@SuppressWarnings("unchecked")
6014	>	MapReduceValuesToLongTask<K,V>
6015	>	t = (MapReduceValuesToLongTask<K,V>)c,
6016	>	s = t.rights;
6017	>	while (s != null) {
6018	>	t.result = reducer.applyAsLong(t.result, s.result);
6019	>	s = t.rights = s.nextRight;
6020	>	}
6021	>	}
6022	>	}
6023	>	}
6024	>	}
6025	>
6026	>	@SuppressWarnings("serial")
6027	>	static final class MapReduceEntriesToLongTask<K,V>
6028	>	extends BulkTask<K,V,Long> {
6029	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6030	>	final LongBinaryOperator reducer;
6031	>	final long basis;
6032	>	long result;
6033	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
6034	>	MapReduceEntriesToLongTask
6035	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6036	>	MapReduceEntriesToLongTask<K,V> nextRight,
6037	>	ToLongFunction<Map.Entry<K,V>> transformer,
6038	>	long basis,
6039	>	LongBinaryOperator reducer) {
6040	>	super(p, b, i, f, t); this.nextRight = nextRight;
6041	>	this.transformer = transformer;
6042	>	this.basis = basis; this.reducer = reducer;
6043	>	}
6044	>	public final Long getRawResult() { return result; }
6045	>	public final void compute() {
6046	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6047	>	final LongBinaryOperator reducer;
6048	>	if ((transformer = this.transformer) != null &&
6049	>	(reducer = this.reducer) != null) {
6050	>	long r = this.basis;
6051	>	for (int i = baseIndex, f, h; batch > 0 &&
6052	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6053	>	addToPendingCount(1);
6054	>	(rights = new MapReduceEntriesToLongTask<K,V>
6055	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6056	>	rights, transformer, r, reducer)).fork();
6057	>	}
6058	>	for (Node<K,V> p; (p = advance()) != null; )
6059	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6060	>	result = r;
6061	>	CountedCompleter<?> c;
6062	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6063	>	@SuppressWarnings("unchecked")
6064	>	MapReduceEntriesToLongTask<K,V>
6065	>	t = (MapReduceEntriesToLongTask<K,V>)c,
6066	>	s = t.rights;
6067	>	while (s != null) {
6068	>	t.result = reducer.applyAsLong(t.result, s.result);
6069	>	s = t.rights = s.nextRight;
6070	>	}
6071	>	}
6072	>	}
6073	>	}
6074	>	}
6075	>
6076	>	@SuppressWarnings("serial")
6077	>	static final class MapReduceMappingsToLongTask<K,V>
6078	>	extends BulkTask<K,V,Long> {
6079	>	final ToLongBiFunction<? super K, ? super V> transformer;
6080	>	final LongBinaryOperator reducer;
6081	>	final long basis;
6082	>	long result;
6083	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6084	>	MapReduceMappingsToLongTask
6085	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6086	>	MapReduceMappingsToLongTask<K,V> nextRight,
6087	>	ToLongBiFunction<? super K, ? super V> transformer,
6088	>	long basis,
6089	>	LongBinaryOperator reducer) {
6090	>	super(p, b, i, f, t); this.nextRight = nextRight;
6091	>	this.transformer = transformer;
6092	>	this.basis = basis; this.reducer = reducer;
6093	>	}
6094	>	public final Long getRawResult() { return result; }
6095	>	public final void compute() {
6096	>	final ToLongBiFunction<? super K, ? super V> transformer;
6097	>	final LongBinaryOperator reducer;
6098	>	if ((transformer = this.transformer) != null &&
6099	>	(reducer = this.reducer) != null) {
6100	>	long r = this.basis;
6101	>	for (int i = baseIndex, f, h; batch > 0 &&
6102	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6103	>	addToPendingCount(1);
6104	>	(rights = new MapReduceMappingsToLongTask<K,V>
6105	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6106	>	rights, transformer, r, reducer)).fork();
6107	>	}
6108	>	for (Node<K,V> p; (p = advance()) != null; )
6109	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6110	>	result = r;
6111	>	CountedCompleter<?> c;
6112	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6113	>	@SuppressWarnings("unchecked")
6114	>	MapReduceMappingsToLongTask<K,V>
6115	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6116	>	s = t.rights;
6117	>	while (s != null) {
6118	>	t.result = reducer.applyAsLong(t.result, s.result);
6119	>	s = t.rights = s.nextRight;
6120	>	}
6121	>	}
6122	>	}
6123	>	}
6124	>	}
6125	>
6126	>	@SuppressWarnings("serial")
6127	>	static final class MapReduceKeysToIntTask<K,V>
6128	>	extends BulkTask<K,V,Integer> {
6129	>	final ToIntFunction<? super K> transformer;
6130	>	final IntBinaryOperator reducer;
6131	>	final int basis;
6132	>	int result;
6133	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6134	>	MapReduceKeysToIntTask
6135	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6136	>	MapReduceKeysToIntTask<K,V> nextRight,
6137	>	ToIntFunction<? super K> transformer,
6138	>	int basis,
6139	>	IntBinaryOperator reducer) {
6140	>	super(p, b, i, f, t); this.nextRight = nextRight;
6141	>	this.transformer = transformer;
6142	>	this.basis = basis; this.reducer = reducer;
6143	>	}
6144	>	public final Integer getRawResult() { return result; }
6145	>	public final void compute() {
6146	>	final ToIntFunction<? super K> transformer;
6147	>	final IntBinaryOperator reducer;
6148	>	if ((transformer = this.transformer) != null &&
6149	>	(reducer = this.reducer) != null) {
6150	>	int r = this.basis;
6151	>	for (int i = baseIndex, f, h; batch > 0 &&
6152	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6153	>	addToPendingCount(1);
6154	>	(rights = new MapReduceKeysToIntTask<K,V>
6155	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6156	>	rights, transformer, r, reducer)).fork();
6157	>	}
6158	>	for (Node<K,V> p; (p = advance()) != null; )
6159	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6160	>	result = r;
6161	>	CountedCompleter<?> c;
6162	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6163	>	@SuppressWarnings("unchecked")
6164	>	MapReduceKeysToIntTask<K,V>
6165	>	t = (MapReduceKeysToIntTask<K,V>)c,
6166	>	s = t.rights;
6167	>	while (s != null) {
6168	>	t.result = reducer.applyAsInt(t.result, s.result);
6169	>	s = t.rights = s.nextRight;
6170	>	}
6171	>	}
6172	>	}
6173	>	}
6174	>	}
6175	>
6176	>	@SuppressWarnings("serial")
6177	>	static final class MapReduceValuesToIntTask<K,V>
6178	>	extends BulkTask<K,V,Integer> {
6179	>	final ToIntFunction<? super V> transformer;
6180	>	final IntBinaryOperator reducer;
6181	>	final int basis;
6182	>	int result;
6183	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6184	>	MapReduceValuesToIntTask
6185	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6186	>	MapReduceValuesToIntTask<K,V> nextRight,
6187	>	ToIntFunction<? super V> transformer,
6188	>	int basis,
6189	>	IntBinaryOperator reducer) {
6190	>	super(p, b, i, f, t); this.nextRight = nextRight;
6191	>	this.transformer = transformer;
6192	>	this.basis = basis; this.reducer = reducer;
6193	>	}
6194	>	public final Integer getRawResult() { return result; }
6195	>	public final void compute() {
6196	>	final ToIntFunction<? super V> transformer;
6197	>	final IntBinaryOperator reducer;
6198	>	if ((transformer = this.transformer) != null &&
6199	>	(reducer = this.reducer) != null) {
6200	>	int r = this.basis;
6201	>	for (int i = baseIndex, f, h; batch > 0 &&
6202	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6203	>	addToPendingCount(1);
6204	>	(rights = new MapReduceValuesToIntTask<K,V>
6205	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6206	>	rights, transformer, r, reducer)).fork();
6207	>	}
6208	>	for (Node<K,V> p; (p = advance()) != null; )
6209	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6210	>	result = r;
6211	>	CountedCompleter<?> c;
6212	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6213	>	@SuppressWarnings("unchecked")
6214	>	MapReduceValuesToIntTask<K,V>
6215	>	t = (MapReduceValuesToIntTask<K,V>)c,
6216	>	s = t.rights;
6217	>	while (s != null) {
6218	>	t.result = reducer.applyAsInt(t.result, s.result);
6219	>	s = t.rights = s.nextRight;
6220	>	}
6221	>	}
6222	>	}
6223	>	}
6224	>	}
6225	>
6226	>	@SuppressWarnings("serial")
6227	>	static final class MapReduceEntriesToIntTask<K,V>
6228	>	extends BulkTask<K,V,Integer> {
6229	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6230	>	final IntBinaryOperator reducer;
6231	>	final int basis;
6232	>	int result;
6233	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6234	>	MapReduceEntriesToIntTask
6235	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6236	>	MapReduceEntriesToIntTask<K,V> nextRight,
6237	>	ToIntFunction<Map.Entry<K,V>> transformer,
6238	>	int basis,
6239	>	IntBinaryOperator reducer) {
6240	>	super(p, b, i, f, t); this.nextRight = nextRight;
6241	>	this.transformer = transformer;
6242	>	this.basis = basis; this.reducer = reducer;
6243	>	}
6244	>	public final Integer getRawResult() { return result; }
6245	>	public final void compute() {
6246	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6247	>	final IntBinaryOperator reducer;
6248	>	if ((transformer = this.transformer) != null &&
6249	>	(reducer = this.reducer) != null) {
6250	>	int r = this.basis;
6251	>	for (int i = baseIndex, f, h; batch > 0 &&
6252	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6253	>	addToPendingCount(1);
6254	>	(rights = new MapReduceEntriesToIntTask<K,V>
6255	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6256	>	rights, transformer, r, reducer)).fork();
6257	>	}
6258	>	for (Node<K,V> p; (p = advance()) != null; )
6259	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6260	>	result = r;
6261	>	CountedCompleter<?> c;
6262	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6263	>	@SuppressWarnings("unchecked")
6264	>	MapReduceEntriesToIntTask<K,V>
6265	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6266	>	s = t.rights;
6267	>	while (s != null) {
6268	>	t.result = reducer.applyAsInt(t.result, s.result);
6269	>	s = t.rights = s.nextRight;
6270	>	}
6271	>	}
6272	>	}
6273	>	}
6274	>	}
6275	>
6276	>	@SuppressWarnings("serial")
6277	>	static final class MapReduceMappingsToIntTask<K,V>
6278	>	extends BulkTask<K,V,Integer> {
6279	>	final ToIntBiFunction<? super K, ? super V> transformer;
6280	>	final IntBinaryOperator reducer;
6281	>	final int basis;
6282	>	int result;
6283	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6284	>	MapReduceMappingsToIntTask
6285	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6286	>	MapReduceMappingsToIntTask<K,V> nextRight,
6287	>	ToIntBiFunction<? super K, ? super V> transformer,
6288	>	int basis,
6289	>	IntBinaryOperator reducer) {
6290	>	super(p, b, i, f, t); this.nextRight = nextRight;
6291	>	this.transformer = transformer;
6292	>	this.basis = basis; this.reducer = reducer;
6293	>	}
6294	>	public final Integer getRawResult() { return result; }
6295	>	public final void compute() {
6296	>	final ToIntBiFunction<? super K, ? super V> transformer;
6297	>	final IntBinaryOperator reducer;
6298	>	if ((transformer = this.transformer) != null &&
6299	>	(reducer = this.reducer) != null) {
6300	>	int r = this.basis;
6301	>	for (int i = baseIndex, f, h; batch > 0 &&
6302	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6303	>	addToPendingCount(1);
6304	>	(rights = new MapReduceMappingsToIntTask<K,V>
6305	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6306	>	rights, transformer, r, reducer)).fork();
6307	>	}
6308	>	for (Node<K,V> p; (p = advance()) != null; )
6309	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6310	>	result = r;
6311	>	CountedCompleter<?> c;
6312	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6313	>	@SuppressWarnings("unchecked")
6314	>	MapReduceMappingsToIntTask<K,V>
6315	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6316	>	s = t.rights;
6317	>	while (s != null) {
6318	>	t.result = reducer.applyAsInt(t.result, s.result);
6319	>	s = t.rights = s.nextRight;
6320	>	}
6321	>	}
6322	>	}
6323		}
6324		}
6325
6326		// Unsafe mechanics
6327	<	private static final sun.misc.Unsafe UNSAFE;
6328	<	private static final long SBASE;
6329	<	private static final int SSHIFT;
6330	<	private static final long TBASE;
6331	<	private static final int TSHIFT;
6327	>	private static final Unsafe U = Unsafe.getUnsafe();
6328	>	private static final long SIZECTL;
6329	>	private static final long TRANSFERINDEX;
6330	>	private static final long BASECOUNT;
6331	>	private static final long CELLSBUSY;
6332	>	private static final long CELLVALUE;
6333	>	private static final int ABASE;
6334	>	private static final int ASHIFT;
6335
6336		static {
1467	–	int ss, ts;
6337		try {
6338	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6339	<	Class<?> tc = HashEntry[].class;
6340	<	Class<?> sc = Segment[].class;
6341	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6342	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6343	<	ts = UNSAFE.arrayIndexScale(tc);
6344	<	ss = UNSAFE.arrayIndexScale(sc);
6345	<	} catch (Exception e) {
6346	<	throw new Error(e);
6347	<	}
6348	<	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
6349	<	throw new Error("data type scale not a power of two");
6350	<	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
6351	<	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6352	<	}
6338	>	SIZECTL = U.objectFieldOffset
6339	>	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6340	>	TRANSFERINDEX = U.objectFieldOffset
6341	>	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6342	>	BASECOUNT = U.objectFieldOffset
6343	>	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6344	>	CELLSBUSY = U.objectFieldOffset
6345	>	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6346	>
6347	>	CELLVALUE = U.objectFieldOffset
6348	>	(CounterCell.class.getDeclaredField("value"));
6349	>
6350	>	ABASE = U.arrayBaseOffset(Node[].class);
6351	>	int scale = U.arrayIndexScale(Node[].class);
6352	>	if ((scale & (scale - 1)) != 0)
6353	>	throw new ExceptionInInitializerError("array index scale not a power of two");
6354	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6355	>	} catch (ReflectiveOperationException e) {
6356	>	throw new ExceptionInInitializerError(e);
6357	>	}
6358	>
6359	>	// Reduce the risk of rare disastrous classloading in first call to
6360	>	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6361	>	Class<?> ensureLoaded = LockSupport.class;
6362
6363	+	// Eager class load observed to help JIT during startup
6364	+	ensureLoaded = ReservationNode.class;
6365	+	}
6366		}

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