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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.110 by jsr166, Wed Apr 27 14:06:30 2011 UTC vs.
Revision 1.271 by dl, Tue Apr 28 23:06:53 2015 UTC

#	Line 5 | Line 5
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
16	>	import java.util.Enumeration;
17	>	import java.util.HashMap;
18	>	import java.util.Hashtable;
19	>	import java.util.Iterator;
20	>	import java.util.Map;
21	>	import java.util.NoSuchElementException;
22	>	import java.util.Set;
23	>	import java.util.Spliterator;
24	>	import java.util.concurrent.atomic.AtomicReference;
25	>	import java.util.concurrent.locks.LockSupport;
26	>	import java.util.concurrent.locks.ReentrantLock;
27	>	import java.util.function.BiConsumer;
28	>	import java.util.function.BiFunction;
29	>	import java.util.function.Consumer;
30	>	import java.util.function.DoubleBinaryOperator;
31	>	import java.util.function.Function;
32	>	import java.util.function.IntBinaryOperator;
33	>	import java.util.function.LongBinaryOperator;
34	>	import java.util.function.Predicate;
35	>	import java.util.function.ToDoubleBiFunction;
36	>	import java.util.function.ToDoubleFunction;
37	>	import java.util.function.ToIntBiFunction;
38	>	import java.util.function.ToIntFunction;
39	>	import java.util.function.ToLongBiFunction;
40	>	import java.util.function.ToLongFunction;
41	>	import java.util.stream.Stream;
42
43		/**
44		* A hash table supporting full concurrency of retrievals and
45	<	* adjustable expected concurrency for updates. This class obeys the
45	>	* high expected concurrency for updates. This class obeys the
46		* same functional specification as {@link java.util.Hashtable}, and
47		* includes versions of methods corresponding to each method of
48	<	* <tt>Hashtable</tt>. However, even though all operations are
48	>	* {@code Hashtable}. However, even though all operations are
49		* thread-safe, retrieval operations do <em>not</em> entail locking,
50		* and there is <em>not</em> any support for locking the entire table
51		* in a way that prevents all access.  This class is fully
52	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
52	>	* interoperable with {@code Hashtable} in programs that rely on its
53		* thread safety but not on its synchronization details.
54		*
55	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
56	<	* block, so may overlap with update operations (including
57	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
58	<	* of the most recently <em>completed</em> update operations holding
59	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
60	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
61	<	* removal of only some entries.  Similarly, Iterators and
62	<	* Enumerations return elements reflecting the state of the hash table
63	<	* at some point at or since the creation of the iterator/enumeration.
64	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
55	>	* <p>Retrieval operations (including {@code get}) generally do not
56	>	* block, so may overlap with update operations (including {@code put}
57	>	* and {@code remove}). Retrievals reflect the results of the most
58	>	* recently <em>completed</em> update operations holding upon their
59	>	* onset. (More formally, an update operation for a given key bears a
60	>	* <em>happens-before</em> relation with any (non-null) retrieval for
61	>	* that key reporting the updated value.)  For aggregate operations
62	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
63	>	* reflect insertion or removal of only some entries.  Similarly,
64	>	* Iterators, Spliterators and Enumerations return elements reflecting the
65	>	* state of the hash table at some point at or since the creation of the
66	>	* iterator/enumeration.  They do <em>not</em> throw {@link
67	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
68		* However, iterators are designed to be used by only one thread at a time.
69	+	* Bear in mind that the results of aggregate status methods including
70	+	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
71	+	* useful only when a map is not undergoing concurrent updates in other threads.
72	+	* Otherwise the results of these methods reflect transient states
73	+	* that may be adequate for monitoring or estimation purposes, but not
74	+	* for program control.
75	+	*
76	+	* <p>The table is dynamically expanded when there are too many
77	+	* collisions (i.e., keys that have distinct hash codes but fall into
78	+	* the same slot modulo the table size), with the expected average
79	+	* effect of maintaining roughly two bins per mapping (corresponding
80	+	* to a 0.75 load factor threshold for resizing). There may be much
81	+	* variance around this average as mappings are added and removed, but
82	+	* overall, this maintains a commonly accepted time/space tradeoff for
83	+	* hash tables.  However, resizing this or any other kind of hash
84	+	* table may be a relatively slow operation. When possible, it is a
85	+	* good idea to provide a size estimate as an optional {@code
86	+	* initialCapacity} constructor argument. An additional optional
87	+	* {@code loadFactor} constructor argument provides a further means of
88	+	* customizing initial table capacity by specifying the table density
89	+	* to be used in calculating the amount of space to allocate for the
90	+	* given number of elements.  Also, for compatibility with previous
91	+	* versions of this class, constructors may optionally specify an
92	+	* expected {@code concurrencyLevel} as an additional hint for
93	+	* internal sizing.  Note that using many keys with exactly the same
94	+	* {@code hashCode()} is a sure way to slow down performance of any
95	+	* hash table. To ameliorate impact, when keys are {@link Comparable},
96	+	* this class may use comparison order among keys to help break ties.
97	+	*
98	+	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
99	+	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
100	+	* (using {@link #keySet(Object)} when only keys are of interest, and the
101	+	* mapped values are (perhaps transiently) not used or all take the
102	+	* same mapping value.
103		*
104	<	* <p> The allowed concurrency among update operations is guided by
105	<	* the optional <tt>concurrencyLevel</tt> constructor argument
106	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
107	<	* table is internally partitioned to try to permit the indicated
108	<	* number of concurrent updates without contention. Because placement
109	<	* in hash tables is essentially random, the actual concurrency will
45	<	* vary.  Ideally, you should choose a value to accommodate as many
46	<	* threads as will ever concurrently modify the table. Using a
47	<	* significantly higher value than you need can waste space and time,
48	<	* and a significantly lower value can lead to thread contention. But
49	<	* overestimates and underestimates within an order of magnitude do
50	<	* not usually have much noticeable impact. A value of one is
51	<	* appropriate when it is known that only one thread will modify and
52	<	* all others will only read. Also, resizing this or any other kind of
53	<	* hash table is a relatively slow operation, so, when possible, it is
54	<	* a good idea to provide estimates of expected table sizes in
55	<	* constructors.
104	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
105	>	* form of histogram or multiset) by using {@link
106	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
107	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
108	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
109	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
110		*
111		* <p>This class and its views and iterators implement all of the
112		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
113		* interfaces.
114		*
115	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
116	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
115	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
116	>	* does <em>not</em> allow {@code null} to be used as a key or value.
117	>	*
118	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
119	>	* operations that, unlike most {@link Stream} methods, are designed
120	>	* to be safely, and often sensibly, applied even with maps that are
121	>	* being concurrently updated by other threads; for example, when
122	>	* computing a snapshot summary of the values in a shared registry.
123	>	* There are three kinds of operation, each with four forms, accepting
124	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
125	>	* and/or return values. Because the elements of a ConcurrentHashMap
126	>	* are not ordered in any particular way, and may be processed in
127	>	* different orders in different parallel executions, the correctness
128	>	* of supplied functions should not depend on any ordering, or on any
129	>	* other objects or values that may transiently change while
130	>	* computation is in progress; and except for forEach actions, should
131	>	* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
132	>	* objects do not support method {@code setValue}.
133	>	*
134	>	* <ul>
135	>	* <li> forEach: Perform a given action on each element.
136	>	* A variant form applies a given transformation on each element
137	>	* before performing the action.</li>
138	>	*
139	>	* <li> search: Return the first available non-null result of
140	>	* applying a given function on each element; skipping further
141	>	* search when a result is found.</li>
142	>	*
143	>	* <li> reduce: Accumulate each element.  The supplied reduction
144	>	* function cannot rely on ordering (more formally, it should be
145	>	* both associative and commutative).  There are five variants:
146	>	*
147	>	* <ul>
148	>	*
149	>	* <li> Plain reductions. (There is not a form of this method for
150	>	* (key, value) function arguments since there is no corresponding
151	>	* return type.)</li>
152	>	*
153	>	* <li> Mapped reductions that accumulate the results of a given
154	>	* function applied to each element.</li>
155	>	*
156	>	* <li> Reductions to scalar doubles, longs, and ints, using a
157	>	* given basis value.</li>
158	>	*
159	>	* </ul>
160	>	* </li>
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">
#	Line 70 | Line 232 | import java.io.ObjectOutputStream;
232		* @param <K> the type of keys maintained by this map
233		* @param <V> the type of mapped values
234		*/
235	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
236	<	implements ConcurrentMap<K, V>, Serializable {
235	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
236	>	implements ConcurrentMap<K,V>, Serializable {
237		private static final long serialVersionUID = 7249069246763182397L;
238
239		/*
240	<	* The basic strategy is to subdivide the table among Segments,
241	<	* each of which itself is a concurrently readable hash table.  To
242	<	* reduce footprint, all but one segments are constructed only
243	<	* when first needed (see ensureSegment). To maintain visibility
244	<	* in the presence of lazy construction, accesses to segments as
245	<	* well as elements of segment's table must use volatile access,
246	<	* which is done via Unsafe within methods segmentAt etc
247	<	* below. These provide the functionality of AtomicReferenceArrays
248	<	* but reduce the levels of indirection. Additionally,
249	<	* volatile-writes of table elements and entry "next" fields
250	<	* within locked operations use the cheaper "lazySet" forms of
251	<	* writes (via putOrderedObject) because these writes are always
252	<	* followed by lock releases that maintain sequential consistency
253	<	* of table updates.
254	<	*
255	<	* Historical note: The previous version of this class relied
256	<	* heavily on "final" fields, which avoided some volatile reads at
257	<	* the expense of a large initial footprint.  Some remnants of
258	<	* that design (including forced construction of segment 0) exist
259	<	* to ensure serialization compatibility.
240	>	* Overview:
241	>	*
242	>	* The primary design goal of this hash table is to maintain
243	>	* concurrent readability (typically method get(), but also
244	>	* iterators and related methods) while minimizing update
245	>	* contention. Secondary goals are to keep space consumption about
246	>	* the same or better than java.util.HashMap, and to support high
247	>	* initial insertion rates on an empty table by many threads.
248	>	*
249	>	* This map usually acts as a binned (bucketed) hash table.  Each
250	>	* key-value mapping is held in a Node.  Most nodes are instances
251	>	* of the basic Node class with hash, key, value, and next
252	>	* fields. However, various subclasses exist: TreeNodes are
253	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
254	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
255	>	* of bins during resizing. ReservationNodes are used as
256	>	* placeholders while establishing values in computeIfAbsent and
257	>	* related methods.  The types TreeBin, ForwardingNode, and
258	>	* ReservationNode do not hold normal user keys, values, or
259	>	* hashes, and are readily distinguishable during search etc
260	>	* because they have negative hash fields and null key and value
261	>	* fields. (These special nodes are either uncommon or transient,
262	>	* so the impact of carrying around some unused fields is
263	>	* insignificant.)
264	>	*
265	>	* The table is lazily initialized to a power-of-two size upon the
266	>	* first insertion.  Each bin in the table normally contains a
267	>	* list of Nodes (most often, the list has only zero or one Node).
268	>	* Table accesses require volatile/atomic reads, writes, and
269	>	* CASes.  Because there is no other way to arrange this without
270	>	* adding further indirections, we use intrinsics
271	>	* (sun.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 refering to
452	>	* concurrencyLevel. We accept a loadFactor constructor argument,
453	>	* but apply it only to initial table capacity (which is the only
454	>	* time that we can guarantee to honor it.) We also declare an
455	>	* unused "Segment" class that is instantiated in minimal form
456	>	* only when serializing.
457	>	*
458	>	* Also, solely for compatibility with previous versions of this
459	>	* class, it extends AbstractMap, even though all of its methods
460	>	* are overridden, so it is just useless baggage.
461	>	*
462	>	* This file is organized to make things a little easier to follow
463	>	* while reading than they might otherwise: First the main static
464	>	* declarations and utilities, then fields, then main public
465	>	* methods (with a few factorings of multiple public methods into
466	>	* internal ones), then sizing methods, trees, traversers, and
467	>	* bulk operations.
468		*/
469
470		/* ---------------- Constants -------------- */
471
472		/**
473	<	* The default initial capacity for this table,
474	<	* used when not otherwise specified in a constructor.
473	>	* The largest possible table capacity.  This value must be
474	>	* exactly 1<<30 to stay within Java array allocation and indexing
475	>	* bounds for power of two table sizes, and is further required
476	>	* because the top two bits of 32bit hash fields are used for
477	>	* control purposes.
478		*/
479	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
479	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
480
481		/**
482	<	* The default load factor for this table, used when not
483	<	* otherwise specified in a constructor.
482	>	* The default initial table capacity.  Must be a power of 2
483	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
484		*/
485	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
485	>	private static final int DEFAULT_CAPACITY = 16;
486
487		/**
488	<	* The default concurrency level for this table, used when not
489	<	* otherwise specified in a constructor.
488	>	* The largest possible (non-power of two) array size.
489	>	* Needed by toArray and related methods.
490		*/
491	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
491	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
492
493		/**
494	<	* The maximum capacity, used if a higher value is implicitly
495	<	* specified by either of the constructors with arguments.  MUST
123	<	* be a power of two <= 1<<30 to ensure that entries are indexable
124	<	* using ints.
494	>	* The default concurrency level for this table. Unused but
495	>	* defined for compatibility with previous versions of this class.
496		*/
497	<	static final int MAXIMUM_CAPACITY = 1 << 30;
497	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
498
499		/**
500	<	* The minimum capacity for per-segment tables.  Must be a power
501	<	* of two, at least two to avoid immediate resizing on next use
502	<	* after lazy construction.
500	>	* The load factor for this table. Overrides of this value in
501	>	* constructors affect only the initial table capacity.  The
502	>	* actual floating point value isn't normally used -- it is
503	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
504	>	* the associated resizing threshold.
505		*/
506	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
506	>	private static final float LOAD_FACTOR = 0.75f;
507
508		/**
509	<	* The maximum number of segments to allow; used to bound
510	<	* constructor arguments. Must be power of two less than 1 << 24.
509	>	* The bin count threshold for using a tree rather than list for a
510	>	* bin.  Bins are converted to trees when adding an element to a
511	>	* bin with at least this many nodes. The value must be greater
512	>	* than 2, and should be at least 8 to mesh with assumptions in
513	>	* tree removal about conversion back to plain bins upon
514	>	* shrinkage.
515		*/
516	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
516	>	static final int TREEIFY_THRESHOLD = 8;
517
518		/**
519	<	* Number of unsynchronized retries in size and containsValue
520	<	* methods before resorting to locking. This is used to avoid
521	<	* unbounded retries if tables undergo continuous modification
145	<	* which would make it impossible to obtain an accurate result.
519	>	* The bin count threshold for untreeifying a (split) bin during a
520	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
521	>	* most 6 to mesh with shrinkage detection under removal.
522		*/
523	<	static final int RETRIES_BEFORE_LOCK = 2;
148	<
149	<	/* ---------------- Fields -------------- */
523	>	static final int UNTREEIFY_THRESHOLD = 6;
524
525		/**
526	<	* Mask value for indexing into segments. The upper bits of a
527	<	* key's hash code are used to choose the segment.
526	>	* The smallest table capacity for which bins may be treeified.
527	>	* (Otherwise the table is resized if too many nodes in a bin.)
528	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
529	>	* conflicts between resizing and treeification thresholds.
530		*/
531	<	final int segmentMask;
531	>	static final int MIN_TREEIFY_CAPACITY = 64;
532
533		/**
534	<	* Shift value for indexing within segments.
534	>	* Minimum number of rebinnings per transfer step. Ranges are
535	>	* subdivided to allow multiple resizer threads.  This value
536	>	* serves as a lower bound to avoid resizers encountering
537	>	* excessive memory contention.  The value should be at least
538	>	* DEFAULT_CAPACITY.
539		*/
540	<	final int segmentShift;
540	>	private static final int MIN_TRANSFER_STRIDE = 16;
541
542		/**
543	<	* The segments, each of which is a specialized hash table.
543	>	* The number of bits used for generation stamp in sizeCtl.
544	>	* Must be at least 6 for 32bit arrays.
545		*/
546	<	final Segment<K,V>[] segments;
546	>	private static 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	>	/** For serialization compatibility. */
571	>	private static final ObjectStreamField[] serialPersistentFields = {
572	>	new ObjectStreamField("segments", Segment[].class),
573	>	new ObjectStreamField("segmentMask", Integer.TYPE),
574	>	new ObjectStreamField("segmentShift", Integer.TYPE)
575	>	};
576	>
577	>	/* ---------------- Nodes -------------- */
578	>
579	>	/**
580	>	* Key-value entry.  This class is never exported out as a
581	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
582	>	* MapEntry below), but can be used for read-only traversals used
583	>	* in bulk tasks.  Subclasses of Node with a negative hash field
584	>	* are special, and contain null keys and values (but are never
585	>	* exported).  Otherwise, keys and vals are never null.
586		*/
587	<	static final class HashEntry<K,V> {
587	>	static class Node<K,V> implements Map.Entry<K,V> {
588		final int hash;
589		final K key;
590	<	volatile V value;
591	<	volatile HashEntry<K,V> next;
590	>	volatile V val;
591	>	volatile Node<K,V> next;
592
593	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
593	>	Node(int hash, K key, V val, Node<K,V> next) {
594		this.hash = hash;
595		this.key = key;
596	<	this.value = value;
596	>	this.val = val;
597		this.next = next;
598		}
599
600	+	public final K getKey()     { return key; }
601	+	public final V getValue()   { return val; }
602	+	public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
603	+	public final String toString() {
604	+	return Helpers.mapEntryToString(key, val);
605	+	}
606	+	public final V setValue(V value) {
607	+	throw new UnsupportedOperationException();
608	+	}
609	+
610	+	public final boolean equals(Object o) {
611	+	Object k, v, u; Map.Entry<?,?> e;
612	+	return ((o instanceof Map.Entry) &&
613	+	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
614	+	(v = e.getValue()) != null &&
615	+	(k == key || k.equals(key)) &&
616	+	(v == (u = val) || v.equals(u)));
617	+	}
618	+
619		/**
620	<	* Sets next field with volatile write semantics.  (See above
190	<	* about use of putOrderedObject.)
620	>	* Virtualized support for map.get(); overridden in subclasses.
621		*/
622	<	final void setNext(HashEntry<K,V> n) {
623	<	UNSAFE.putOrderedObject(this, nextOffset, n);
622	>	Node<K,V> find(int h, Object k) {
623	>	Node<K,V> e = this;
624	>	if (k != null) {
625	>	do {
626	>	K ek;
627	>	if (e.hash == h &&
628	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
629	>	return e;
630	>	} while ((e = e.next) != null);
631	>	}
632	>	return null;
633		}
634	+	}
635
636	<	// Unsafe mechanics
637	<	static final sun.misc.Unsafe UNSAFE;
638	<	static final long nextOffset;
639	<	static {
640	<	try {
641	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
642	<	Class k = HashEntry.class;
643	<	nextOffset = UNSAFE.objectFieldOffset
644	<	(k.getDeclaredField("next"));
645	<	} catch (Exception e) {
646	<	throw new Error(e);
636	>	/* ---------------- Static utilities -------------- */
637	>
638	>	/**
639	>	* Spreads (XORs) higher bits of hash to lower and also forces top
640	>	* bit to 0. Because the table uses power-of-two masking, sets of
641	>	* hashes that vary only in bits above the current mask will
642	>	* always collide. (Among known examples are sets of Float keys
643	>	* holding consecutive whole numbers in small tables.)  So we
644	>	* apply a transform that spreads the impact of higher bits
645	>	* downward. There is a tradeoff between speed, utility, and
646	>	* quality of bit-spreading. Because many common sets of hashes
647	>	* are already reasonably distributed (so don't benefit from
648	>	* spreading), and because we use trees to handle large sets of
649	>	* collisions in bins, we just XOR some shifted bits in the
650	>	* cheapest possible way to reduce systematic lossage, as well as
651	>	* to incorporate impact of the highest bits that would otherwise
652	>	* never be used in index calculations because of table bounds.
653	>	*/
654	>	static final int spread(int h) {
655	>	return (h ^ (h >>> 16)) & HASH_BITS;
656	>	}
657	>
658	>	/**
659	>	* Returns a power of two table size for the given desired capacity.
660	>	* See Hackers Delight, sec 3.2
661	>	*/
662	>	private static final int tableSizeFor(int c) {
663	>	int n = c - 1;
664	>	n |= n >>> 1;
665	>	n |= n >>> 2;
666	>	n |= n >>> 4;
667	>	n |= n >>> 8;
668	>	n |= n >>> 16;
669	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
670	>	}
671	>
672	>	/**
673	>	* Returns x's Class if it is of the form "class C implements
674	>	* Comparable<C>", else null.
675	>	*/
676	>	static Class<?> comparableClassFor(Object x) {
677	>	if (x instanceof Comparable) {
678	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
679	>	if ((c = x.getClass()) == String.class) // bypass checks
680	>	return c;
681	>	if ((ts = c.getGenericInterfaces()) != null) {
682	>	for (int i = 0; i < ts.length; ++i) {
683	>	if (((t = ts[i]) instanceof ParameterizedType) &&
684	>	((p = (ParameterizedType)t).getRawType() ==
685	>	Comparable.class) &&
686	>	(as = p.getActualTypeArguments()) != null &&
687	>	as.length == 1 && as[0] == c) // type arg is c
688	>	return c;
689	>	}
690		}
691		}
692	+	return null;
693		}
694
695		/**
696	<	* Gets the ith element of given table (if nonnull) with volatile
697	<	* read semantics. Note: This is manually integrated into a few
214	<	* performance-sensitive methods to reduce call overhead.
696	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
697	>	* class), else 0.
698		*/
699	+	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
700	+	static int compareComparables(Class<?> kc, Object k, Object x) {
701	+	return (x == null || x.getClass() != kc ? 0 :
702	+	((Comparable)k).compareTo(x));
703	+	}
704	+
705	+	/* ---------------- Table element access -------------- */
706	+
707	+	/*
708	+	* Volatile access methods are used for table elements as well as
709	+	* elements of in-progress next table while resizing.  All uses of
710	+	* the tab arguments must be null checked by callers.  All callers
711	+	* also paranoically precheck that tab's length is not zero (or an
712	+	* equivalent check), thus ensuring that any index argument taking
713	+	* the form of a hash value anded with (length - 1) is a valid
714	+	* index.  Note that, to be correct wrt arbitrary concurrency
715	+	* errors by users, these checks must operate on local variables,
716	+	* which accounts for some odd-looking inline assignments below.
717	+	* Note that calls to setTabAt always occur within locked regions,
718	+	* and so in principle require only release ordering, not
719	+	* full volatile semantics, but are currently coded as volatile
720	+	* writes to be conservative.
721	+	*/
722	+
723		@SuppressWarnings("unchecked")
724	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
725	<	return (tab == null) ? null :
219	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
220	<	(tab, ((long)i << TSHIFT) + TBASE);
724	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
725	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
726		}
727
728	+	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
729	+	Node<K,V> c, Node<K,V> v) {
730	+	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
731	+	}
732	+
733	+	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
734	+	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
735	+	}
736	+
737	+	/* ---------------- Fields -------------- */
738	+
739	+	/**
740	+	* The array of bins. Lazily initialized upon first insertion.
741	+	* Size is always a power of two. Accessed directly by iterators.
742	+	*/
743	+	transient volatile Node<K,V>[] table;
744	+
745	+	/**
746	+	* The next table to use; non-null only while resizing.
747	+	*/
748	+	private transient volatile Node<K,V>[] nextTable;
749	+
750	+	/**
751	+	* Base counter value, used mainly when there is no contention,
752	+	* but also as a fallback during table initialization
753	+	* races. Updated via CAS.
754	+	*/
755	+	private transient volatile long baseCount;
756	+
757	+	/**
758	+	* Table initialization and resizing control.  When negative, the
759	+	* table is being initialized or resized: -1 for initialization,
760	+	* else -(1 + the number of active resizing threads).  Otherwise,
761	+	* when table is null, holds the initial table size to use upon
762	+	* creation, or 0 for default. After initialization, holds the
763	+	* next element count value upon which to resize the table.
764	+	*/
765	+	private transient volatile int sizeCtl;
766	+
767	+	/**
768	+	* The next table index (plus one) to split while resizing.
769	+	*/
770	+	private transient volatile int transferIndex;
771	+
772	+	/**
773	+	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
774	+	*/
775	+	private transient volatile int cellsBusy;
776	+
777	+	/**
778	+	* Table of counter cells. When non-null, size is a power of 2.
779	+	*/
780	+	private transient volatile CounterCell[] counterCells;
781	+
782	+	// views
783	+	private transient KeySetView<K,V> keySet;
784	+	private transient ValuesView<K,V> values;
785	+	private transient EntrySetView<K,V> entrySet;
786	+
787	+
788	+	/* ---------------- Public operations -------------- */
789	+
790		/**
791	<	* Sets the ith element of given table, with volatile write
225	<	* semantics. (See above about use of putOrderedObject.)
791	>	* Creates a new, empty map with the default initial table size (16).
792		*/
793	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
228	<	HashEntry<K,V> e) {
229	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
793	>	public ConcurrentHashMap() {
794		}
795
796		/**
797	<	* Applies a supplemental hash function to a given hashCode, which
798	<	* defends against poor quality hash functions.  This is critical
799	<	* because ConcurrentHashMap uses power-of-two length hash tables,
800	<	* that otherwise encounter collisions for hashCodes that do not
801	<	* differ in lower or upper bits.
797	>	* Creates a new, empty map with an initial table size
798	>	* accommodating the specified number of elements without the need
799	>	* to dynamically resize.
800	>	*
801	>	* @param initialCapacity The implementation performs internal
802	>	* sizing to accommodate this many elements.
803	>	* @throws IllegalArgumentException if the initial capacity of
804	>	* elements is negative
805		*/
806	<	private static int hash(int h) {
807	<	// Spread bits to regularize both segment and index locations,
808	<	// using variant of single-word Wang/Jenkins hash.
809	<	h += (h <<  15) ^ 0xffffcd7d;
810	<	h ^= (h >>> 10);
811	<	h += (h <<   3);
812	<	h ^= (h >>>  6);
246	<	h += (h <<   2) + (h << 14);
247	<	return h ^ (h >>> 16);
806	>	public ConcurrentHashMap(int initialCapacity) {
807	>	if (initialCapacity < 0)
808	>	throw new IllegalArgumentException();
809	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
810	>	MAXIMUM_CAPACITY :
811	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
812	>	this.sizeCtl = cap;
813		}
814
815		/**
816	<	* Segments are specialized versions of hash tables.  This
817	<	* subclasses from ReentrantLock opportunistically, just to
818	<	* simplify some locking and avoid separate construction.
816	>	* Creates a new map with the same mappings as the given map.
817	>	*
818	>	* @param m the map
819		*/
820	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
821	<	/*
822	<	* Segments maintain a table of entry lists that are always
823	<	* kept in a consistent state, so can be read (via volatile
259	<	* reads of segments and tables) without locking.  This
260	<	* requires replicating nodes when necessary during table
261	<	* resizing, so the old lists can be traversed by readers
262	<	* still using old version of table.
263	<	*
264	<	* This class defines only mutative methods requiring locking.
265	<	* Except as noted, the methods of this class perform the
266	<	* per-segment versions of ConcurrentHashMap methods.  (Other
267	<	* methods are integrated directly into ConcurrentHashMap
268	<	* methods.) These mutative methods use a form of controlled
269	<	* spinning on contention via methods scanAndLock and
270	<	* scanAndLockForPut. These intersperse tryLocks with
271	<	* traversals to locate nodes.  The main benefit is to absorb
272	<	* cache misses (which are very common for hash tables) while
273	<	* obtaining locks so that traversal is faster once
274	<	* acquired. We do not actually use the found nodes since they
275	<	* must be re-acquired under lock anyway to ensure sequential
276	<	* consistency of updates (and in any case may be undetectably
277	<	* stale), but they will normally be much faster to re-locate.
278	<	* Also, scanAndLockForPut speculatively creates a fresh node
279	<	* to use in put if no node is found.
280	<	*/
820	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
821	>	this.sizeCtl = DEFAULT_CAPACITY;
822	>	putAll(m);
823	>	}
824
825	<	private static final long serialVersionUID = 2249069246763182397L;
825	>	/**
826	>	* Creates a new, empty map with an initial table size based on
827	>	* the given number of elements ({@code initialCapacity}) and
828	>	* initial table density ({@code loadFactor}).
829	>	*
830	>	* @param initialCapacity the initial capacity. The implementation
831	>	* performs internal sizing to accommodate this many elements,
832	>	* given the specified load factor.
833	>	* @param loadFactor the load factor (table density) for
834	>	* establishing the initial table size
835	>	* @throws IllegalArgumentException if the initial capacity of
836	>	* elements is negative or the load factor is nonpositive
837	>	*
838	>	* @since 1.6
839	>	*/
840	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
841	>	this(initialCapacity, loadFactor, 1);
842	>	}
843
844	<	/**
845	<	* The maximum number of times to tryLock in a prescan before
846	<	* possibly blocking on acquire in preparation for a locked
847	<	* segment operation. On multiprocessors, using a bounded
848	<	* number of retries maintains cache acquired while locating
849	<	* nodes.
850	<	*/
851	<	static final int MAX_SCAN_RETRIES =
852	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
844	>	/**
845	>	* Creates a new, empty map with an initial table size based on
846	>	* the given number of elements ({@code initialCapacity}), table
847	>	* density ({@code loadFactor}), and number of concurrently
848	>	* updating threads ({@code concurrencyLevel}).
849	>	*
850	>	* @param initialCapacity the initial capacity. The implementation
851	>	* performs internal sizing to accommodate this many elements,
852	>	* given the specified load factor.
853	>	* @param loadFactor the load factor (table density) for
854	>	* establishing the initial table size
855	>	* @param concurrencyLevel the estimated number of concurrently
856	>	* updating threads. The implementation may use this value as
857	>	* a sizing hint.
858	>	* @throws IllegalArgumentException if the initial capacity is
859	>	* negative or the load factor or concurrencyLevel are
860	>	* nonpositive
861	>	*/
862	>	public ConcurrentHashMap(int initialCapacity,
863	>	float loadFactor, int concurrencyLevel) {
864	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
865	>	throw new IllegalArgumentException();
866	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
867	>	initialCapacity = concurrencyLevel;   // as estimated threads
868	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
869	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
870	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
871	>	this.sizeCtl = cap;
872	>	}
873
874	<	/**
295	<	* The per-segment table. Elements are accessed via
296	<	* entryAt/setEntryAt providing volatile semantics.
297	<	*/
298	<	transient volatile HashEntry<K,V>[] table;
874	>	// Original (since JDK1.2) Map methods
875
876	<	/**
877	<	* The number of elements. Accessed only either within locks
878	<	* or among other volatile reads that maintain visibility.
879	<	*/
880	<	transient int count;
876	>	/**
877	>	* {@inheritDoc}
878	>	*/
879	>	public int size() {
880	>	long n = sumCount();
881	>	return ((n < 0L) ? 0 :
882	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
883	>	(int)n);
884	>	}
885
886	<	/**
887	<	* The total number of mutative operations in this segment.
888	<	* Even though this may overflows 32 bits, it provides
889	<	* sufficient accuracy for stability checks in CHM isEmpty()
890	<	* and size() methods.  Accessed only either within locks or
891	<	* among other volatile reads that maintain visibility.
312	<	*/
313	<	transient int modCount;
886	>	/**
887	>	* {@inheritDoc}
888	>	*/
889	>	public boolean isEmpty() {
890	>	return sumCount() <= 0L; // ignore transient negative values
891	>	}
892
893	<	/**
894	<	* The table is rehashed when its size exceeds this threshold.
895	<	* (The value of this field is always <tt>(int)(capacity *
896	<	* loadFactor)</tt>.)
897	<	*/
898	<	transient int threshold;
893	>	/**
894	>	* Returns the value to which the specified key is mapped,
895	>	* or {@code null} if this map contains no mapping for the key.
896	>	*
897	>	* <p>More formally, if this map contains a mapping from a key
898	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
899	>	* then this method returns {@code v}; otherwise it returns
900	>	* {@code null}.  (There can be at most one such mapping.)
901	>	*
902	>	* @throws NullPointerException if the specified key is null
903	>	*/
904	>	public V get(Object key) {
905	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
906	>	int h = spread(key.hashCode());
907	>	if ((tab = table) != null && (n = tab.length) > 0 &&
908	>	(e = tabAt(tab, (n - 1) & h)) != null) {
909	>	if ((eh = e.hash) == h) {
910	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
911	>	return e.val;
912	>	}
913	>	else if (eh < 0)
914	>	return (p = e.find(h, key)) != null ? p.val : null;
915	>	while ((e = e.next) != null) {
916	>	if (e.hash == h &&
917	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
918	>	return e.val;
919	>	}
920	>	}
921	>	return null;
922	>	}
923
924	<	/**
925	<	* The load factor for the hash table.  Even though this value
926	<	* is same for all segments, it is replicated to avoid needing
927	<	* links to outer object.
928	<	* @serial
929	<	*/
930	<	final float loadFactor;
924	>	/**
925	>	* Tests if the specified object is a key in this table.
926	>	*
927	>	* @param  key possible key
928	>	* @return {@code true} if and only if the specified object
929	>	*         is a key in this table, as determined by the
930	>	*         {@code equals} method; {@code false} otherwise
931	>	* @throws NullPointerException if the specified key is null
932	>	*/
933	>	public boolean containsKey(Object key) {
934	>	return get(key) != null;
935	>	}
936
937	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
938	<	this.loadFactor = lf;
939	<	this.threshold = threshold;
940	<	this.table = tab;
937	>	/**
938	>	* Returns {@code true} if this map maps one or more keys to the
939	>	* specified value. Note: This method may require a full traversal
940	>	* of the map, and is much slower than method {@code containsKey}.
941	>	*
942	>	* @param value value whose presence in this map is to be tested
943	>	* @return {@code true} if this map maps one or more keys to the
944	>	*         specified value
945	>	* @throws NullPointerException if the specified value is null
946	>	*/
947	>	public boolean containsValue(Object value) {
948	>	if (value == null)
949	>	throw new NullPointerException();
950	>	Node<K,V>[] t;
951	>	if ((t = table) != null) {
952	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
953	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
954	>	V v;
955	>	if ((v = p.val) == value || (v != null && value.equals(v)))
956	>	return true;
957	>	}
958		}
959	+	return false;
960	+	}
961
962	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
963	<	HashEntry<K,V> node = tryLock() ? null :
964	<	scanAndLockForPut(key, hash, value);
965	<	V oldValue;
966	<	try {
967	<	HashEntry<K,V>[] tab = table;
968	<	int index = (tab.length - 1) & hash;
969	<	HashEntry<K,V> first = entryAt(tab, index);
970	<	for (HashEntry<K,V> e = first;;) {
971	<	if (e != null) {
972	<	K k;
973	<	if ((k = e.key) == key ||
974	<	(e.hash == hash && key.equals(k))) {
975	<	oldValue = e.value;
976	<	if (!onlyIfAbsent) {
977	<	e.value = value;
978	<	++modCount;
962	>	/**
963	>	* Maps the specified key to the specified value in this table.
964	>	* Neither the key nor the value can be null.
965	>	*
966	>	* <p>The value can be retrieved by calling the {@code get} method
967	>	* with a key that is equal to the original key.
968	>	*
969	>	* @param key key with which the specified value is to be associated
970	>	* @param value value to be associated with the specified key
971	>	* @return the previous value associated with {@code key}, or
972	>	*         {@code null} if there was no mapping for {@code key}
973	>	* @throws NullPointerException if the specified key or value is null
974	>	*/
975	>	public V put(K key, V value) {
976	>	return putVal(key, value, false);
977	>	}
978	>
979	>	/** Implementation for put and putIfAbsent */
980	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
981	>	if (key == null || value == null) throw new NullPointerException();
982	>	int hash = spread(key.hashCode());
983	>	int binCount = 0;
984	>	for (Node<K,V>[] tab = table;;) {
985	>	Node<K,V> f; int n, i, fh;
986	>	if (tab == null || (n = tab.length) == 0)
987	>	tab = initTable();
988	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
989	>	if (casTabAt(tab, i, null,
990	>	new Node<K,V>(hash, key, value, null)))
991	>	break;                   // no lock when adding to empty bin
992	>	}
993	>	else if ((fh = f.hash) == MOVED)
994	>	tab = helpTransfer(tab, f);
995	>	else {
996	>	V oldVal = null;
997	>	synchronized (f) {
998	>	if (tabAt(tab, i) == f) {
999	>	if (fh >= 0) {
1000	>	binCount = 1;
1001	>	for (Node<K,V> e = f;; ++binCount) {
1002	>	K ek;
1003	>	if (e.hash == hash &&
1004	>	((ek = e.key) == key ||
1005	>	(ek != null && key.equals(ek)))) {
1006	>	oldVal = e.val;
1007	>	if (!onlyIfAbsent)
1008	>	e.val = value;
1009	>	break;
1010	>	}
1011	>	Node<K,V> pred = e;
1012	>	if ((e = e.next) == null) {
1013	>	pred.next = new Node<K,V>(hash, key,
1014	>	value, null);
1015	>	break;
1016	>	}
1017		}
354	–	break;
1018		}
1019	<	e = e.next;
1020	<	}
1021	<	else {
1022	<	if (node != null)
1023	<	node.setNext(first);
1024	<	else
1025	<	node = new HashEntry<K,V>(hash, key, value, first);
1026	<	int c = count + 1;
1027	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
1028	<	rehash(node);
1029	<	else
1030	<	setEntryAt(tab, index, node);
368	<	++modCount;
369	<	count = c;
370	<	oldValue = null;
371	<	break;
372	<	}
373	<	}
374	<	} finally {
375	<	unlock();
376	<	}
377	<	return oldValue;
378	<	}
379	<
380	<	/**
381	<	* Doubles size of table and repacks entries, also adding the
382	<	* given node to new table
383	<	*/
384	<	@SuppressWarnings("unchecked")
385	<	private void rehash(HashEntry<K,V> node) {
386	<	/*
387	<	* Reclassify nodes in each list to new table.  Because we
388	<	* are using power-of-two expansion, the elements from
389	<	* each bin must either stay at same index, or move with a
390	<	* power of two offset. We eliminate unnecessary node
391	<	* creation by catching cases where old nodes can be
392	<	* reused because their next fields won't change.
393	<	* Statistically, at the default threshold, only about
394	<	* one-sixth of them need cloning when a table
395	<	* doubles. The nodes they replace will be garbage
396	<	* collectable as soon as they are no longer referenced by
397	<	* any reader thread that may be in the midst of
398	<	* concurrently traversing table. Entry accesses use plain
399	<	* array indexing because they are followed by volatile
400	<	* table write.
401	<	*/
402	<	HashEntry<K,V>[] oldTable = table;
403	<	int oldCapacity = oldTable.length;
404	<	int newCapacity = oldCapacity << 1;
405	<	threshold = (int)(newCapacity * loadFactor);
406	<	HashEntry<K,V>[] newTable =
407	<	(HashEntry<K,V>[]) new HashEntry[newCapacity];
408	<	int sizeMask = newCapacity - 1;
409	<	for (int i = 0; i < oldCapacity ; i++) {
410	<	HashEntry<K,V> e = oldTable[i];
411	<	if (e != null) {
412	<	HashEntry<K,V> next = e.next;
413	<	int idx = e.hash & sizeMask;
414	<	if (next == null)   //  Single node on list
415	<	newTable[idx] = e;
416	<	else { // Reuse consecutive sequence at same slot
417	<	HashEntry<K,V> lastRun = e;
418	<	int lastIdx = idx;
419	<	for (HashEntry<K,V> last = next;
420	<	last != null;
421	<	last = last.next) {
422	<	int k = last.hash & sizeMask;
423	<	if (k != lastIdx) {
424	<	lastIdx = k;
425	<	lastRun = last;
426	<	}
427	<	}
428	<	newTable[lastIdx] = lastRun;
429	<	// Clone remaining nodes
430	<	for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
431	<	V v = p.value;
432	<	int h = p.hash;
433	<	int k = h & sizeMask;
434	<	HashEntry<K,V> n = newTable[k];
435	<	newTable[k] = new HashEntry<K,V>(h, p.key, v, n);
436	<	}
437	<	}
438	<	}
439	<	}
440	<	int nodeIndex = node.hash & sizeMask; // add the new node
441	<	node.setNext(newTable[nodeIndex]);
442	<	newTable[nodeIndex] = node;
443	<	table = newTable;
444	<	}
445	<
446	<	/**
447	<	* Scans for a node containing given key while trying to
448	<	* acquire lock, creating and returning one if not found. Upon
449	<	* return, guarantees that lock is held. Unlike in most
450	<	* methods, calls to method equals are not screened: Since
451	<	* traversal speed doesn't matter, we might as well help warm
452	<	* up the associated code and accesses as well.
453	<	*
454	<	* @return a new node if key not found, else null
455	<	*/
456	<	private HashEntry<K,V> scanAndLockForPut(K key, int hash, V value) {
457	<	HashEntry<K,V> first = entryForHash(this, hash);
458	<	HashEntry<K,V> e = first;
459	<	HashEntry<K,V> node = null;
460	<	int retries = -1; // negative while locating node
461	<	while (!tryLock()) {
462	<	HashEntry<K,V> f; // to recheck first below
463	<	if (retries < 0) {
464	<	if (e == null) {
465	<	if (node == null) // speculatively create node
466	<	node = new HashEntry<K,V>(hash, key, value, null);
467	<	retries = 0;
1019	>	else if (f instanceof TreeBin) {
1020	>	Node<K,V> p;
1021	>	binCount = 2;
1022	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1023	>	value)) != null) {
1024	>	oldVal = p.val;
1025	>	if (!onlyIfAbsent)
1026	>	p.val = value;
1027	>	}
1028	>	}
1029	>	else if (f instanceof ReservationNode)
1030	>	throw new IllegalStateException("Recursive update");
1031		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
473	–	}
474	–	else if (++retries > MAX_SCAN_RETRIES) {
475	–	lock();
476	–	break;
477	–	}
478	–	else if ((retries & 1) == 0 &&
479	–	(f = entryForHash(this, hash)) != first) {
480	–	e = first = f; // re-traverse if entry changed
481	–	retries = -1;
482	–	}
483	–	}
484	–	return node;
485	–	}
486	–
487	–	/**
488	–	* Scans for a node containing the given key while trying to
489	–	* acquire lock for a remove or replace operation. Upon
490	–	* return, guarantees that lock is held.  Note that we must
491	–	* lock even if the key is not found, to ensure sequential
492	–	* consistency of updates.
493	–	*/
494	–	private void scanAndLock(Object key, int hash) {
495	–	// similar to but simpler than scanAndLockForPut
496	–	HashEntry<K,V> first = entryForHash(this, hash);
497	–	HashEntry<K,V> e = first;
498	–	int retries = -1;
499	–	while (!tryLock()) {
500	–	HashEntry<K,V> f;
501	–	if (retries < 0) {
502	–	if (e == null || key.equals(e.key))
503	–	retries = 0;
504	–	else
505	–	e = e.next;
1032		}
1033	<	else if (++retries > MAX_SCAN_RETRIES) {
1034	<	lock();
1033	>	if (binCount != 0) {
1034	>	if (binCount >= TREEIFY_THRESHOLD)
1035	>	treeifyBin(tab, i);
1036	>	if (oldVal != null)
1037	>	return oldVal;
1038		break;
1039		}
511	–	else if ((retries & 1) == 0 &&
512	–	(f = entryForHash(this, hash)) != first) {
513	–	e = first = f;
514	–	retries = -1;
515	–	}
1040		}
1041		}
1042	+	addCount(1L, binCount);
1043	+	return null;
1044	+	}
1045
1046	<	/**
1047	<	* Remove; match on key only if value null, else match both.
1048	<	*/
1049	<	final V remove(Object key, int hash, Object value) {
1050	<	if (!tryLock())
1051	<	scanAndLock(key, hash);
1052	<	V oldValue = null;
1053	<	try {
1054	<	HashEntry<K,V>[] tab = table;
1055	<	int index = (tab.length - 1) & hash;
1056	<	HashEntry<K,V> e = entryAt(tab, index);
1057	<	HashEntry<K,V> pred = null;
1058	<	while (e != null) {
1059	<	K k;
1060	<	HashEntry<K,V> next = e.next;
1061	<	if ((k = e.key) == key ||
1062	<	(e.hash == hash && key.equals(k))) {
1063	<	V v = e.value;
1064	<	if (value == null || value == v || value.equals(v)) {
1065	<	if (pred == null)
1066	<	setEntryAt(tab, index, next);
1067	<	else
1068	<	pred.setNext(next);
1069	<	++modCount;
1070	<	--count;
1071	<	oldValue = v;
1046	>	/**
1047	>	* Copies all of the mappings from the specified map to this one.
1048	>	* These mappings replace any mappings that this map had for any of the
1049	>	* keys currently in the specified map.
1050	>	*
1051	>	* @param m mappings to be stored in this map
1052	>	*/
1053	>	public void putAll(Map<? extends K, ? extends V> m) {
1054	>	tryPresize(m.size());
1055	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1056	>	putVal(e.getKey(), e.getValue(), false);
1057	>	}
1058	>
1059	>	/**
1060	>	* Removes the key (and its corresponding value) from this map.
1061	>	* This method does nothing if the key is not in the map.
1062	>	*
1063	>	* @param  key the key that needs to be removed
1064	>	* @return the previous value associated with {@code key}, or
1065	>	*         {@code null} if there was no mapping for {@code key}
1066	>	* @throws NullPointerException if the specified key is null
1067	>	*/
1068	>	public V remove(Object key) {
1069	>	return replaceNode(key, null, null);
1070	>	}
1071	>
1072	>	/**
1073	>	* Implementation for the four public remove/replace methods:
1074	>	* Replaces node value with v, conditional upon match of cv if
1075	>	* non-null.  If resulting value is null, delete.
1076	>	*/
1077	>	final V replaceNode(Object key, V value, Object cv) {
1078	>	int hash = spread(key.hashCode());
1079	>	for (Node<K,V>[] tab = table;;) {
1080	>	Node<K,V> f; int n, i, fh;
1081	>	if (tab == null || (n = tab.length) == 0 ||
1082	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1083	>	break;
1084	>	else if ((fh = f.hash) == MOVED)
1085	>	tab = helpTransfer(tab, f);
1086	>	else {
1087	>	V oldVal = null;
1088	>	boolean validated = false;
1089	>	synchronized (f) {
1090	>	if (tabAt(tab, i) == f) {
1091	>	if (fh >= 0) {
1092	>	validated = true;
1093	>	for (Node<K,V> e = f, pred = null;;) {
1094	>	K ek;
1095	>	if (e.hash == hash &&
1096	>	((ek = e.key) == key ||
1097	>	(ek != null && key.equals(ek)))) {
1098	>	V ev = e.val;
1099	>	if (cv == null || cv == ev ||
1100	>	(ev != null && cv.equals(ev))) {
1101	>	oldVal = ev;
1102	>	if (value != null)
1103	>	e.val = value;
1104	>	else if (pred != null)
1105	>	pred.next = e.next;
1106	>	else
1107	>	setTabAt(tab, i, e.next);
1108	>	}
1109	>	break;
1110	>	}
1111	>	pred = e;
1112	>	if ((e = e.next) == null)
1113	>	break;
1114	>	}
1115		}
1116	<	break;
1116	>	else if (f instanceof TreeBin) {
1117	>	validated = true;
1118	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1119	>	TreeNode<K,V> r, p;
1120	>	if ((r = t.root) != null &&
1121	>	(p = r.findTreeNode(hash, key, null)) != null) {
1122	>	V pv = p.val;
1123	>	if (cv == null || cv == pv ||
1124	>	(pv != null && cv.equals(pv))) {
1125	>	oldVal = pv;
1126	>	if (value != null)
1127	>	p.val = value;
1128	>	else if (t.removeTreeNode(p))
1129	>	setTabAt(tab, i, untreeify(t.first));
1130	>	}
1131	>	}
1132	>	}
1133	>	else if (f instanceof ReservationNode)
1134	>	throw new IllegalStateException("Recursive update");
1135		}
548	–	pred = e;
549	–	e = next;
1136		}
1137	<	} finally {
1138	<	unlock();
1139	<	}
1140	<	return oldValue;
1141	<	}
556	<
557	<	final boolean replace(K key, int hash, V oldValue, V newValue) {
558	<	if (!tryLock())
559	<	scanAndLock(key, hash);
560	<	boolean replaced = false;
561	<	try {
562	<	HashEntry<K,V> e;
563	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
564	<	K k;
565	<	if ((k = e.key) == key ||
566	<	(e.hash == hash && key.equals(k))) {
567	<	if (oldValue.equals(e.value)) {
568	<	e.value = newValue;
569	<	++modCount;
570	<	replaced = true;
571	<	}
572	<	break;
1137	>	if (validated) {
1138	>	if (oldVal != null) {
1139	>	if (value == null)
1140	>	addCount(-1L, -1);
1141	>	return oldVal;
1142		}
1143	+	break;
1144		}
575	–	} finally {
576	–	unlock();
1145		}
578	–	return replaced;
1146		}
1147	+	return null;
1148	+	}
1149
1150	<	final V replace(K key, int hash, V value) {
1151	<	if (!tryLock())
1152	<	scanAndLock(key, hash);
1153	<	V oldValue = null;
1154	<	try {
1155	<	HashEntry<K,V> e;
1156	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1157	<	K k;
1158	<	if ((k = e.key) == key ||
1159	<	(e.hash == hash && key.equals(k))) {
1160	<	oldValue = e.value;
1161	<	e.value = value;
1162	<	++modCount;
1163	<	break;
1150	>	/**
1151	>	* Removes all of the mappings from this map.
1152	>	*/
1153	>	public void clear() {
1154	>	long delta = 0L; // negative number of deletions
1155	>	int i = 0;
1156	>	Node<K,V>[] tab = table;
1157	>	while (tab != null && i < tab.length) {
1158	>	int fh;
1159	>	Node<K,V> f = tabAt(tab, i);
1160	>	if (f == null)
1161	>	++i;
1162	>	else if ((fh = f.hash) == MOVED) {
1163	>	tab = helpTransfer(tab, f);
1164	>	i = 0; // restart
1165	>	}
1166	>	else {
1167	>	synchronized (f) {
1168	>	if (tabAt(tab, i) == f) {
1169	>	Node<K,V> p = (fh >= 0 ? f :
1170	>	(f instanceof TreeBin) ?
1171	>	((TreeBin<K,V>)f).first : null);
1172	>	while (p != null) {
1173	>	--delta;
1174	>	p = p.next;
1175	>	}
1176	>	setTabAt(tab, i++, null);
1177		}
1178		}
597	–	} finally {
598	–	unlock();
1179		}
600	–	return oldValue;
1180		}
1181	+	if (delta != 0L)
1182	+	addCount(delta, -1);
1183	+	}
1184
1185	<	final void clear() {
1186	<	lock();
1187	<	try {
1188	<	HashEntry<K,V>[] tab = table;
1189	<	for (int i = 0; i < tab.length ; i++)
1190	<	setEntryAt(tab, i, null);
1191	<	++modCount;
1192	<	count = 0;
1193	<	} finally {
1194	<	unlock();
1195	<	}
1196	<	}
1185	>	/**
1186	>	* Returns a {@link Set} view of the keys contained in this map.
1187	>	* The set is backed by the map, so changes to the map are
1188	>	* reflected in the set, and vice-versa. The set supports element
1189	>	* removal, which removes the corresponding mapping from this map,
1190	>	* via the {@code Iterator.remove}, {@code Set.remove},
1191	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1192	>	* operations.  It does not support the {@code add} or
1193	>	* {@code addAll} operations.
1194	>	*
1195	>	* <p>The view's iterators and spliterators are
1196	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1197	>	*
1198	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1199	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1200	>	*
1201	>	* @return the set view
1202	>	*/
1203	>	public KeySetView<K,V> keySet() {
1204	>	KeySetView<K,V> ks;
1205	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1206	>	}
1207	>
1208	>	/**
1209	>	* Returns a {@link Collection} view of the values contained in this map.
1210	>	* The collection is backed by the map, so changes to the map are
1211	>	* reflected in the collection, and vice-versa.  The collection
1212	>	* supports element removal, which removes the corresponding
1213	>	* mapping from this map, via the {@code Iterator.remove},
1214	>	* {@code Collection.remove}, {@code removeAll},
1215	>	* {@code retainAll}, and {@code clear} operations.  It does not
1216	>	* support the {@code add} or {@code addAll} operations.
1217	>	*
1218	>	* <p>The view's iterators and spliterators are
1219	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1220	>	*
1221	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1222	>	* and {@link Spliterator#NONNULL}.
1223	>	*
1224	>	* @return the collection view
1225	>	*/
1226	>	public Collection<V> values() {
1227	>	ValuesView<K,V> vs;
1228	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1229		}
1230
1231	<	// Accessing segments
1231	>	/**
1232	>	* Returns a {@link Set} view of the mappings contained in this map.
1233	>	* The set is backed by the map, so changes to the map are
1234	>	* reflected in the set, and vice-versa.  The set supports element
1235	>	* removal, which removes the corresponding mapping from the map,
1236	>	* via the {@code Iterator.remove}, {@code Set.remove},
1237	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1238	>	* operations.
1239	>	*
1240	>	* <p>The view's iterators and spliterators are
1241	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1242	>	*
1243	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1244	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1245	>	*
1246	>	* @return the set view
1247	>	*/
1248	>	public Set<Map.Entry<K,V>> entrySet() {
1249	>	EntrySetView<K,V> es;
1250	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1251	>	}
1252
1253		/**
1254	<	* Gets the jth element of given segment array (if nonnull) with
1255	<	* volatile element access semantics via Unsafe. (The null check
1256	<	* can trigger harmlessly only during deserialization.) Note:
1257	<	* because each element of segments array is set only once (using
1258	<	* fully ordered writes), some performance-sensitive methods rely
625	<	* on this method only as a recheck upon null reads.
1254	>	* Returns the hash code value for this {@link Map}, i.e.,
1255	>	* the sum of, for each key-value pair in the map,
1256	>	* {@code key.hashCode() ^ value.hashCode()}.
1257	>	*
1258	>	* @return the hash code value for this map
1259		*/
1260	<	@SuppressWarnings("unchecked")
1261	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1262	<	long u = (j << SSHIFT) + SBASE;
1263	<	return ss == null ? null :
1264	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1260	>	public int hashCode() {
1261	>	int h = 0;
1262	>	Node<K,V>[] t;
1263	>	if ((t = table) != null) {
1264	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1265	>	for (Node<K,V> p; (p = it.advance()) != null; )
1266	>	h += p.key.hashCode() ^ p.val.hashCode();
1267	>	}
1268	>	return h;
1269		}
1270
1271		/**
1272	<	* Returns the segment for the given index, creating it and
1273	<	* recording in segment table (via CAS) if not already present.
1272	>	* Returns a string representation of this map.  The string
1273	>	* representation consists of a list of key-value mappings (in no
1274	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1275	>	* mappings are separated by the characters {@code ", "} (comma
1276	>	* and space).  Each key-value mapping is rendered as the key
1277	>	* followed by an equals sign ("{@code =}") followed by the
1278	>	* associated value.
1279		*
1280	<	* @param k the index
639	<	* @return the segment
1280	>	* @return a string representation of this map
1281		*/
1282	<	@SuppressWarnings("unchecked")
1283	<	private Segment<K,V> ensureSegment(int k) {
1284	<	final Segment<K,V>[] ss = this.segments;
1285	<	long u = (k << SSHIFT) + SBASE; // raw offset
1286	<	Segment<K,V> seg;
1287	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1288	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1289	<	int cap = proto.table.length;
1290	<	float lf = proto.loadFactor;
1291	<	int threshold = (int)(cap * lf);
1292	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry[cap];
1293	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1294	<	== null) { // recheck
1295	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1296	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1297	<	== null) {
1298	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
658	<	break;
659	<	}
1282	>	public String toString() {
1283	>	Node<K,V>[] t;
1284	>	int f = (t = table) == null ? 0 : t.length;
1285	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1286	>	StringBuilder sb = new StringBuilder();
1287	>	sb.append('{');
1288	>	Node<K,V> p;
1289	>	if ((p = it.advance()) != null) {
1290	>	for (;;) {
1291	>	K k = p.key;
1292	>	V v = p.val;
1293	>	sb.append(k == this ? "(this Map)" : k);
1294	>	sb.append('=');
1295	>	sb.append(v == this ? "(this Map)" : v);
1296	>	if ((p = it.advance()) == null)
1297	>	break;
1298	>	sb.append(',').append(' ');
1299		}
1300		}
1301	<	return seg;
1301	>	return sb.append('}').toString();
1302		}
1303
665	–	// Hash-based segment and entry accesses
666	–
1304		/**
1305	<	* Gets the segment for the given hash code.
1305	>	* Compares the specified object with this map for equality.
1306	>	* Returns {@code true} if the given object is a map with the same
1307	>	* mappings as this map.  This operation may return misleading
1308	>	* results if either map is concurrently modified during execution
1309	>	* of this method.
1310	>	*
1311	>	* @param o object to be compared for equality with this map
1312	>	* @return {@code true} if the specified object is equal to this map
1313		*/
1314	<	@SuppressWarnings("unchecked")
1315	<	private Segment<K,V> segmentForHash(int h) {
1316	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1317	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1314	>	public boolean equals(Object o) {
1315	>	if (o != this) {
1316	>	if (!(o instanceof Map))
1317	>	return false;
1318	>	Map<?,?> m = (Map<?,?>) o;
1319	>	Node<K,V>[] t;
1320	>	int f = (t = table) == null ? 0 : t.length;
1321	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1322	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1323	>	V val = p.val;
1324	>	Object v = m.get(p.key);
1325	>	if (v == null || (v != val && !v.equals(val)))
1326	>	return false;
1327	>	}
1328	>	for (Map.Entry<?,?> e : m.entrySet()) {
1329	>	Object mk, mv, v;
1330	>	if ((mk = e.getKey()) == null ||
1331	>	(mv = e.getValue()) == null ||
1332	>	(v = get(mk)) == null ||
1333	>	(mv != v && !mv.equals(v)))
1334	>	return false;
1335	>	}
1336	>	}
1337	>	return true;
1338		}
1339
1340		/**
1341	<	* Gets the table entry for the given segment and hash code.
1341	>	* Stripped-down version of helper class used in previous version,
1342	>	* declared for the sake of serialization compatibility
1343		*/
1344	<	@SuppressWarnings("unchecked")
1345	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1346	<	HashEntry<K,V>[] tab;
1347	<	return (seg == null || (tab = seg.table) == null) ? null :
683	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
684	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1344	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1345	>	private static final long serialVersionUID = 2249069246763182397L;
1346	>	final float loadFactor;
1347	>	Segment(float lf) { this.loadFactor = lf; }
1348		}
1349
687	–	/* ---------------- Public operations -------------- */
688	–
1350		/**
1351	<	* Creates a new, empty map with the specified initial
1352	<	* capacity, load factor and concurrency level.
1353	<	*
1354	<	* @param initialCapacity the initial capacity. The implementation
1355	<	* performs internal sizing to accommodate this many elements.
1356	<	* @param loadFactor  the load factor threshold, used to control resizing.
1357	<	* Resizing may be performed when the average number of elements per
1358	<	* bin exceeds this threshold.
698	<	* @param concurrencyLevel the estimated number of concurrently
699	<	* updating threads. The implementation performs internal sizing
700	<	* to try to accommodate this many threads.
701	<	* @throws IllegalArgumentException if the initial capacity is
702	<	* negative or the load factor or concurrencyLevel are
703	<	* nonpositive.
1351	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1352	>	* stream (i.e., serializes it).
1353	>	* @param s the stream
1354	>	* @throws java.io.IOException if an I/O error occurs
1355	>	* @serialData
1356	>	* the key (Object) and value (Object)
1357	>	* for each key-value mapping, followed by a null pair.
1358	>	* The key-value mappings are emitted in no particular order.
1359		*/
1360	<	@SuppressWarnings("unchecked")
1361	<	public ConcurrentHashMap(int initialCapacity,
1362	<	float loadFactor, int concurrencyLevel) {
1363	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
709	<	throw new IllegalArgumentException();
710	<	if (concurrencyLevel > MAX_SEGMENTS)
711	<	concurrencyLevel = MAX_SEGMENTS;
712	<	// Find power-of-two sizes best matching arguments
1360	>	private void writeObject(java.io.ObjectOutputStream s)
1361	>	throws java.io.IOException {
1362	>	// For serialization compatibility
1363	>	// Emulate segment calculation from previous version of this class
1364		int sshift = 0;
1365		int ssize = 1;
1366	<	while (ssize < concurrencyLevel) {
1366	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1367		++sshift;
1368		ssize <<= 1;
1369		}
1370	<	this.segmentShift = 32 - sshift;
1371	<	this.segmentMask = ssize - 1;
1372	<	if (initialCapacity > MAXIMUM_CAPACITY)
1373	<	initialCapacity = MAXIMUM_CAPACITY;
1374	<	int c = initialCapacity / ssize;
1375	<	if (c * ssize < initialCapacity)
1376	<	++c;
1377	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1378	<	while (cap < c)
1379	<	cap <<= 1;
1380	<	// create segments and segments[0]
1381	<	Segment<K,V> s0 =
1382	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1383	<	(HashEntry<K,V>[])new HashEntry[cap]);
1384	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment[ssize];
1385	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1386	<	this.segments = ss;
1370	>	int segmentShift = 32 - sshift;
1371	>	int segmentMask = ssize - 1;
1372	>	@SuppressWarnings("unchecked")
1373	>	Segment<K,V>[] segments = (Segment<K,V>[])
1374	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1375	>	for (int i = 0; i < segments.length; ++i)
1376	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1377	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1378	>	streamFields.put("segments", segments);
1379	>	streamFields.put("segmentShift", segmentShift);
1380	>	streamFields.put("segmentMask", segmentMask);
1381	>	s.writeFields();
1382	>
1383	>	Node<K,V>[] t;
1384	>	if ((t = table) != null) {
1385	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1386	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1387	>	s.writeObject(p.key);
1388	>	s.writeObject(p.val);
1389	>	}
1390	>	}
1391	>	s.writeObject(null);
1392	>	s.writeObject(null);
1393	>	segments = null; // throw away
1394		}
1395
1396		/**
1397	<	* Creates a new, empty map with the specified initial capacity
1398	<	* and load factor and with the default concurrencyLevel (16).
1399	<	*
1400	<	* @param initialCapacity The implementation performs internal
1401	<	* sizing to accommodate this many elements.
1402	<	* @param loadFactor  the load factor threshold, used to control resizing.
1403	<	* Resizing may be performed when the average number of elements per
1404	<	* bin exceeds this threshold.
1405	<	* @throws IllegalArgumentException if the initial capacity of
1406	<	* elements is negative or the load factor is nonpositive
1397	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1398	>	* @param s the stream
1399	>	* @throws ClassNotFoundException if the class of a serialized object
1400	>	*         could not be found
1401	>	* @throws java.io.IOException if an I/O error occurs
1402	>	*/
1403	>	private void readObject(java.io.ObjectInputStream s)
1404	>	throws java.io.IOException, ClassNotFoundException {
1405	>	/*
1406	>	* To improve performance in typical cases, we create nodes
1407	>	* while reading, then place in table once size is known.
1408	>	* However, we must also validate uniqueness and deal with
1409	>	* overpopulated bins while doing so, which requires
1410	>	* specialized versions of putVal mechanics.
1411	>	*/
1412	>	sizeCtl = -1; // force exclusion for table construction
1413	>	s.defaultReadObject();
1414	>	long size = 0L;
1415	>	Node<K,V> p = null;
1416	>	for (;;) {
1417	>	@SuppressWarnings("unchecked")
1418	>	K k = (K) s.readObject();
1419	>	@SuppressWarnings("unchecked")
1420	>	V v = (V) s.readObject();
1421	>	if (k != null && v != null) {
1422	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1423	>	++size;
1424	>	}
1425	>	else
1426	>	break;
1427	>	}
1428	>	if (size == 0L)
1429	>	sizeCtl = 0;
1430	>	else {
1431	>	int n;
1432	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1433	>	n = MAXIMUM_CAPACITY;
1434	>	else {
1435	>	int sz = (int)size;
1436	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1437	>	}
1438	>	@SuppressWarnings("unchecked")
1439	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1440	>	int mask = n - 1;
1441	>	long added = 0L;
1442	>	while (p != null) {
1443	>	boolean insertAtFront;
1444	>	Node<K,V> next = p.next, first;
1445	>	int h = p.hash, j = h & mask;
1446	>	if ((first = tabAt(tab, j)) == null)
1447	>	insertAtFront = true;
1448	>	else {
1449	>	K k = p.key;
1450	>	if (first.hash < 0) {
1451	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1452	>	if (t.putTreeVal(h, k, p.val) == null)
1453	>	++added;
1454	>	insertAtFront = false;
1455	>	}
1456	>	else {
1457	>	int binCount = 0;
1458	>	insertAtFront = true;
1459	>	Node<K,V> q; K qk;
1460	>	for (q = first; q != null; q = q.next) {
1461	>	if (q.hash == h &&
1462	>	((qk = q.key) == k ||
1463	>	(qk != null && k.equals(qk)))) {
1464	>	insertAtFront = false;
1465	>	break;
1466	>	}
1467	>	++binCount;
1468	>	}
1469	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1470	>	insertAtFront = false;
1471	>	++added;
1472	>	p.next = first;
1473	>	TreeNode<K,V> hd = null, tl = null;
1474	>	for (q = p; q != null; q = q.next) {
1475	>	TreeNode<K,V> t = new TreeNode<K,V>
1476	>	(q.hash, q.key, q.val, null, null);
1477	>	if ((t.prev = tl) == null)
1478	>	hd = t;
1479	>	else
1480	>	tl.next = t;
1481	>	tl = t;
1482	>	}
1483	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1484	>	}
1485	>	}
1486	>	}
1487	>	if (insertAtFront) {
1488	>	++added;
1489	>	p.next = first;
1490	>	setTabAt(tab, j, p);
1491	>	}
1492	>	p = next;
1493	>	}
1494	>	table = tab;
1495	>	sizeCtl = n - (n >>> 2);
1496	>	baseCount = added;
1497	>	}
1498	>	}
1499	>
1500	>	// ConcurrentMap methods
1501	>
1502	>	/**
1503	>	* {@inheritDoc}
1504		*
1505	<	* @since 1.6
1505	>	* @return the previous value associated with the specified key,
1506	>	*         or {@code null} if there was no mapping for the key
1507	>	* @throws NullPointerException if the specified key or value is null
1508		*/
1509	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
1510	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1509	>	public V putIfAbsent(K key, V value) {
1510	>	return putVal(key, value, true);
1511		}
1512
1513		/**
1514	<	* Creates a new, empty map with the specified initial capacity,
758	<	* and with default load factor (0.75) and concurrencyLevel (16).
1514	>	* {@inheritDoc}
1515		*
1516	<	* @param initialCapacity the initial capacity. The implementation
761	<	* performs internal sizing to accommodate this many elements.
762	<	* @throws IllegalArgumentException if the initial capacity of
763	<	* elements is negative.
1516	>	* @throws NullPointerException if the specified key is null
1517		*/
1518	<	public ConcurrentHashMap(int initialCapacity) {
1519	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1518	>	public boolean remove(Object key, Object value) {
1519	>	if (key == null)
1520	>	throw new NullPointerException();
1521	>	return value != null && replaceNode(key, null, value) != null;
1522		}
1523
1524		/**
1525	<	* Creates a new, empty map with a default initial capacity (16),
1526	<	* load factor (0.75) and concurrencyLevel (16).
1525	>	* {@inheritDoc}
1526	>	*
1527	>	* @throws NullPointerException if any of the arguments are null
1528		*/
1529	<	public ConcurrentHashMap() {
1530	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1529	>	public boolean replace(K key, V oldValue, V newValue) {
1530	>	if (key == null || oldValue == null || newValue == null)
1531	>	throw new NullPointerException();
1532	>	return replaceNode(key, newValue, oldValue) != null;
1533		}
1534
1535		/**
1536	<	* Creates a new map with the same mappings as the given map.
779	<	* The map is created with a capacity of 1.5 times the number
780	<	* of mappings in the given map or 16 (whichever is greater),
781	<	* and a default load factor (0.75) and concurrencyLevel (16).
1536	>	* {@inheritDoc}
1537		*
1538	<	* @param m the map
1538	>	* @return the previous value associated with the specified key,
1539	>	*         or {@code null} if there was no mapping for the key
1540	>	* @throws NullPointerException if the specified key or value is null
1541		*/
1542	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1543	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1544	<	DEFAULT_INITIAL_CAPACITY),
1545	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
1542	>	public V replace(K key, V value) {
1543	>	if (key == null || value == null)
1544	>	throw new NullPointerException();
1545	>	return replaceNode(key, value, null);
1546		}
1547
1548	+	// Overrides of JDK8+ Map extension method defaults
1549	+
1550		/**
1551	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1551	>	* Returns the value to which the specified key is mapped, or the
1552	>	* given default value if this map contains no mapping for the
1553	>	* key.
1554		*
1555	<	* @return <tt>true</tt> if this map contains no key-value mappings
1555	>	* @param key the key whose associated value is to be returned
1556	>	* @param defaultValue the value to return if this map contains
1557	>	* no mapping for the given key
1558	>	* @return the mapping for the key, if present; else the default value
1559	>	* @throws NullPointerException if the specified key is null
1560		*/
1561	<	public boolean isEmpty() {
1562	<	/*
1563	<	* Sum per-segment modCounts to avoid mis-reporting when
1564	<	* elements are concurrently added and removed in one segment
1565	<	* while checking another, in which case the table was never
1566	<	* actually empty at any point. (The sum ensures accuracy up
1567	<	* through at least 1<<31 per-segment modifications before
1568	<	* recheck.)  Methods size() and containsValue() use similar
1569	<	* constructions for stability checks.
1570	<	*/
1571	<	long sum = 0L;
1572	<	final Segment<K,V>[] segments = this.segments;
809	<	for (int j = 0; j < segments.length; ++j) {
810	<	Segment<K,V> seg = segmentAt(segments, j);
811	<	if (seg != null) {
812	<	if (seg.count != 0)
813	<	return false;
814	<	sum += seg.modCount;
1561	>	public V getOrDefault(Object key, V defaultValue) {
1562	>	V v;
1563	>	return (v = get(key)) == null ? defaultValue : v;
1564	>	}
1565	>
1566	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1567	>	if (action == null) throw new NullPointerException();
1568	>	Node<K,V>[] t;
1569	>	if ((t = table) != null) {
1570	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1571	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1572	>	action.accept(p.key, p.val);
1573		}
1574		}
1575	<	if (sum != 0L) { // recheck unless no modifications
1576	<	for (int j = 0; j < segments.length; ++j) {
1577	<	Segment<K,V> seg = segmentAt(segments, j);
1578	<	if (seg != null) {
1579	<	if (seg.count != 0)
1580	<	return false;
1581	<	sum -= seg.modCount;
1575	>	}
1576	>
1577	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1578	>	if (function == null) throw new NullPointerException();
1579	>	Node<K,V>[] t;
1580	>	if ((t = table) != null) {
1581	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1582	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1583	>	V oldValue = p.val;
1584	>	for (K key = p.key;;) {
1585	>	V newValue = function.apply(key, oldValue);
1586	>	if (newValue == null)
1587	>	throw new NullPointerException();
1588	>	if (replaceNode(key, newValue, oldValue) != null ||
1589	>	(oldValue = get(key)) == null)
1590	>	break;
1591		}
1592		}
826	–	if (sum != 0L)
827	–	return false;
1593		}
829	–	return true;
1594		}
1595
1596		/**
1597	<	* Returns the number of key-value mappings in this map.  If the
1598	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
1599	<	* <tt>Integer.MAX_VALUE</tt>.
1597	>	* Helper method for EntrySet.removeIf
1598	>	*/
1599	>	boolean removeEntryIf(Predicate<? super Entry<K, V>> function) {
1600	>	if (function == null) throw new NullPointerException();
1601	>	Node<K,V>[] t;
1602	>	boolean removed = false;
1603	>	if ((t = table) != null) {
1604	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1605	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1606	>	K k = p.key;
1607	>	V v = p.val;
1608	>	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1609	>	if (function.test(e) && replaceNode(k, null, v) != null)
1610	>	removed = true;
1611	>	}
1612	>	}
1613	>	return removed;
1614	>	}
1615	>
1616	>	/**
1617	>	* If the specified key is not already associated with a value,
1618	>	* attempts to compute its value using the given mapping function
1619	>	* and enters it into this map unless {@code null}.  The entire
1620	>	* method invocation is performed atomically, so the function is
1621	>	* applied at most once per key.  Some attempted update operations
1622	>	* on this map by other threads may be blocked while computation
1623	>	* is in progress, so the computation should be short and simple,
1624	>	* and must not attempt to update any other mappings of this map.
1625		*
1626	<	* @return the number of key-value mappings in this map
1626	>	* @param key key with which the specified value is to be associated
1627	>	* @param mappingFunction the function to compute a value
1628	>	* @return the current (existing or computed) value associated with
1629	>	*         the specified key, or null if the computed value is null
1630	>	* @throws NullPointerException if the specified key or mappingFunction
1631	>	*         is null
1632	>	* @throws IllegalStateException if the computation detectably
1633	>	*         attempts a recursive update to this map that would
1634	>	*         otherwise never complete
1635	>	* @throws RuntimeException or Error if the mappingFunction does so,
1636	>	*         in which case the mapping is left unestablished
1637		*/
1638	<	public int size() {
1639	<	// Try a few times to get accurate count. On failure due to
1640	<	// continuous async changes in table, resort to locking.
1641	<	final Segment<K,V>[] segments = this.segments;
1642	<	int size;
1643	<	boolean overflow; // true if size overflows 32 bits
1644	<	long sum;         // sum of modCounts
1645	<	long last = 0L;   // previous sum
1646	<	int retries = -1; // first iteration isn't retry
1647	<	try {
1648	<	for (;;) {
1649	<	if (retries++ == RETRIES_BEFORE_LOCK) {
1650	<	for (int j = 0; j < segments.length; ++j)
1651	<	ensureSegment(j).lock(); // force creation
1652	<	}
1653	<	sum = 0L;
1654	<	size = 0;
1655	<	overflow = false;
1656	<	for (int j = 0; j < segments.length; ++j) {
1657	<	Segment<K,V> seg = segmentAt(segments, j);
1658	<	if (seg != null) {
1659	<	sum += seg.modCount;
861	<	int c = seg.count;
862	<	if (c < 0 || (size += c) < 0)
863	<	overflow = true;
1638	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1639	>	if (key == null || mappingFunction == null)
1640	>	throw new NullPointerException();
1641	>	int h = spread(key.hashCode());
1642	>	V val = null;
1643	>	int binCount = 0;
1644	>	for (Node<K,V>[] tab = table;;) {
1645	>	Node<K,V> f; int n, i, fh;
1646	>	if (tab == null || (n = tab.length) == 0)
1647	>	tab = initTable();
1648	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1649	>	Node<K,V> r = new ReservationNode<K,V>();
1650	>	synchronized (r) {
1651	>	if (casTabAt(tab, i, null, r)) {
1652	>	binCount = 1;
1653	>	Node<K,V> node = null;
1654	>	try {
1655	>	if ((val = mappingFunction.apply(key)) != null)
1656	>	node = new Node<K,V>(h, key, val, null);
1657	>	} finally {
1658	>	setTabAt(tab, i, node);
1659	>	}
1660		}
1661		}
1662	<	if (sum == last)
1662	>	if (binCount != 0)
1663		break;
868	–	last = sum;
1664		}
1665	<	} finally {
1666	<	if (retries > RETRIES_BEFORE_LOCK) {
1667	<	for (int j = 0; j < segments.length; ++j)
1668	<	segmentAt(segments, j).unlock();
1665	>	else if ((fh = f.hash) == MOVED)
1666	>	tab = helpTransfer(tab, f);
1667	>	else {
1668	>	boolean added = false;
1669	>	synchronized (f) {
1670	>	if (tabAt(tab, i) == f) {
1671	>	if (fh >= 0) {
1672	>	binCount = 1;
1673	>	for (Node<K,V> e = f;; ++binCount) {
1674	>	K ek;
1675	>	if (e.hash == h &&
1676	>	((ek = e.key) == key ||
1677	>	(ek != null && key.equals(ek)))) {
1678	>	val = e.val;
1679	>	break;
1680	>	}
1681	>	Node<K,V> pred = e;
1682	>	if ((e = e.next) == null) {
1683	>	if ((val = mappingFunction.apply(key)) != null) {
1684	>	if (pred.next != null)
1685	>	throw new IllegalStateException("Recursive update");
1686	>	added = true;
1687	>	pred.next = new Node<K,V>(h, key, val, null);
1688	>	}
1689	>	break;
1690	>	}
1691	>	}
1692	>	}
1693	>	else if (f instanceof TreeBin) {
1694	>	binCount = 2;
1695	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1696	>	TreeNode<K,V> r, p;
1697	>	if ((r = t.root) != null &&
1698	>	(p = r.findTreeNode(h, key, null)) != null)
1699	>	val = p.val;
1700	>	else if ((val = mappingFunction.apply(key)) != null) {
1701	>	added = true;
1702	>	t.putTreeVal(h, key, val);
1703	>	}
1704	>	}
1705	>	else if (f instanceof ReservationNode)
1706	>	throw new IllegalStateException("Recursive update");
1707	>	}
1708	>	}
1709	>	if (binCount != 0) {
1710	>	if (binCount >= TREEIFY_THRESHOLD)
1711	>	treeifyBin(tab, i);
1712	>	if (!added)
1713	>	return val;
1714	>	break;
1715	>	}
1716		}
1717		}
1718	<	return overflow ? Integer.MAX_VALUE : size;
1718	>	if (val != null)
1719	>	addCount(1L, binCount);
1720	>	return val;
1721		}
1722
1723		/**
1724	<	* Returns the value to which the specified key is mapped,
1725	<	* or {@code null} if this map contains no mapping for the key.
1726	<	*
1727	<	* <p>More formally, if this map contains a mapping from a key
1728	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1729	<	* then this method returns {@code v}; otherwise it returns
1730	<	* {@code null}.  (There can be at most one such mapping.)
1724	>	* If the value for the specified key is present, attempts to
1725	>	* compute a new mapping given the key and its current mapped
1726	>	* value.  The entire method invocation is performed atomically.
1727	>	* Some attempted update operations on this map by other threads
1728	>	* may be blocked while computation is in progress, so the
1729	>	* computation should be short and simple, and must not attempt to
1730	>	* update any other mappings of this map.
1731		*
1732	<	* @throws NullPointerException if the specified key is null
1732	>	* @param key key with which a value may be associated
1733	>	* @param remappingFunction the function to compute a value
1734	>	* @return the new value associated with the specified key, or null if none
1735	>	* @throws NullPointerException if the specified key or remappingFunction
1736	>	*         is null
1737	>	* @throws IllegalStateException if the computation detectably
1738	>	*         attempts a recursive update to this map that would
1739	>	*         otherwise never complete
1740	>	* @throws RuntimeException or Error if the remappingFunction does so,
1741	>	*         in which case the mapping is unchanged
1742		*/
1743	<	public V get(Object key) {
1744	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1745	<	HashEntry<K,V>[] tab;
1746	<	int h = hash(key.hashCode());
1747	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1748	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1749	<	(tab = s.table) != null) {
1750	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1751	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1752	<	e != null; e = e.next) {
1753	<	K k;
1754	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1755	<	return e.value;
1743	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1744	>	if (key == null || remappingFunction == null)
1745	>	throw new NullPointerException();
1746	>	int h = spread(key.hashCode());
1747	>	V val = null;
1748	>	int delta = 0;
1749	>	int binCount = 0;
1750	>	for (Node<K,V>[] tab = table;;) {
1751	>	Node<K,V> f; int n, i, fh;
1752	>	if (tab == null || (n = tab.length) == 0)
1753	>	tab = initTable();
1754	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1755	>	break;
1756	>	else if ((fh = f.hash) == MOVED)
1757	>	tab = helpTransfer(tab, f);
1758	>	else {
1759	>	synchronized (f) {
1760	>	if (tabAt(tab, i) == f) {
1761	>	if (fh >= 0) {
1762	>	binCount = 1;
1763	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1764	>	K ek;
1765	>	if (e.hash == h &&
1766	>	((ek = e.key) == key ||
1767	>	(ek != null && key.equals(ek)))) {
1768	>	val = remappingFunction.apply(key, e.val);
1769	>	if (val != null)
1770	>	e.val = val;
1771	>	else {
1772	>	delta = -1;
1773	>	Node<K,V> en = e.next;
1774	>	if (pred != null)
1775	>	pred.next = en;
1776	>	else
1777	>	setTabAt(tab, i, en);
1778	>	}
1779	>	break;
1780	>	}
1781	>	pred = e;
1782	>	if ((e = e.next) == null)
1783	>	break;
1784	>	}
1785	>	}
1786	>	else if (f instanceof TreeBin) {
1787	>	binCount = 2;
1788	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1789	>	TreeNode<K,V> r, p;
1790	>	if ((r = t.root) != null &&
1791	>	(p = r.findTreeNode(h, key, null)) != null) {
1792	>	val = remappingFunction.apply(key, p.val);
1793	>	if (val != null)
1794	>	p.val = val;
1795	>	else {
1796	>	delta = -1;
1797	>	if (t.removeTreeNode(p))
1798	>	setTabAt(tab, i, untreeify(t.first));
1799	>	}
1800	>	}
1801	>	}
1802	>	else if (f instanceof ReservationNode)
1803	>	throw new IllegalStateException("Recursive update");
1804	>	}
1805	>	}
1806	>	if (binCount != 0)
1807	>	break;
1808		}
1809		}
1810	<	return null;
1810	>	if (delta != 0)
1811	>	addCount((long)delta, binCount);
1812	>	return val;
1813		}
1814
1815		/**
1816	<	* Tests if the specified object is a key in this table.
1816	>	* Attempts to compute a mapping for the specified key and its
1817	>	* current mapped value (or {@code null} if there is no current
1818	>	* mapping). The entire method invocation is performed atomically.
1819	>	* Some attempted update operations on this map by other threads
1820	>	* may be blocked while computation is in progress, so the
1821	>	* computation should be short and simple, and must not attempt to
1822	>	* update any other mappings of this Map.
1823		*
1824	<	* @param  key   possible key
1825	<	* @return <tt>true</tt> if and only if the specified object
1826	<	*         is a key in this table, as determined by the
1827	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1828	<	* @throws NullPointerException if the specified key is null
1829	<	*/
1830	<	@SuppressWarnings("unchecked")
1831	<	public boolean containsKey(Object key) {
1832	<	Segment<K,V> s; // same as get() except no need for volatile value read
1833	<	HashEntry<K,V>[] tab;
1834	<	int h = hash(key.hashCode());
1835	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1836	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1837	<	(tab = s.table) != null) {
1838	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1839	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1840	<	e != null; e = e.next) {
1841	<	K k;
1842	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1843	<	return true;
1824	>	* @param key key with which the specified value is to be associated
1825	>	* @param remappingFunction the function to compute a value
1826	>	* @return the new value associated with the specified key, or null if none
1827	>	* @throws NullPointerException if the specified key or remappingFunction
1828	>	*         is null
1829	>	* @throws IllegalStateException if the computation detectably
1830	>	*         attempts a recursive update to this map that would
1831	>	*         otherwise never complete
1832	>	* @throws RuntimeException or Error if the remappingFunction does so,
1833	>	*         in which case the mapping is unchanged
1834	>	*/
1835	>	public V compute(K key,
1836	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1837	>	if (key == null || remappingFunction == null)
1838	>	throw new NullPointerException();
1839	>	int h = spread(key.hashCode());
1840	>	V val = null;
1841	>	int delta = 0;
1842	>	int binCount = 0;
1843	>	for (Node<K,V>[] tab = table;;) {
1844	>	Node<K,V> f; int n, i, fh;
1845	>	if (tab == null || (n = tab.length) == 0)
1846	>	tab = initTable();
1847	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1848	>	Node<K,V> r = new ReservationNode<K,V>();
1849	>	synchronized (r) {
1850	>	if (casTabAt(tab, i, null, r)) {
1851	>	binCount = 1;
1852	>	Node<K,V> node = null;
1853	>	try {
1854	>	if ((val = remappingFunction.apply(key, null)) != null) {
1855	>	delta = 1;
1856	>	node = new Node<K,V>(h, key, val, null);
1857	>	}
1858	>	} finally {
1859	>	setTabAt(tab, i, node);
1860	>	}
1861	>	}
1862	>	}
1863	>	if (binCount != 0)
1864	>	break;
1865	>	}
1866	>	else if ((fh = f.hash) == MOVED)
1867	>	tab = helpTransfer(tab, f);
1868	>	else {
1869	>	synchronized (f) {
1870	>	if (tabAt(tab, i) == f) {
1871	>	if (fh >= 0) {
1872	>	binCount = 1;
1873	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1874	>	K ek;
1875	>	if (e.hash == h &&
1876	>	((ek = e.key) == key ||
1877	>	(ek != null && key.equals(ek)))) {
1878	>	val = remappingFunction.apply(key, e.val);
1879	>	if (val != null)
1880	>	e.val = val;
1881	>	else {
1882	>	delta = -1;
1883	>	Node<K,V> en = e.next;
1884	>	if (pred != null)
1885	>	pred.next = en;
1886	>	else
1887	>	setTabAt(tab, i, en);
1888	>	}
1889	>	break;
1890	>	}
1891	>	pred = e;
1892	>	if ((e = e.next) == null) {
1893	>	val = remappingFunction.apply(key, null);
1894	>	if (val != null) {
1895	>	if (pred.next != null)
1896	>	throw new IllegalStateException("Recursive update");
1897	>	delta = 1;
1898	>	pred.next =
1899	>	new Node<K,V>(h, key, val, null);
1900	>	}
1901	>	break;
1902	>	}
1903	>	}
1904	>	}
1905	>	else if (f instanceof TreeBin) {
1906	>	binCount = 1;
1907	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1908	>	TreeNode<K,V> r, p;
1909	>	if ((r = t.root) != null)
1910	>	p = r.findTreeNode(h, key, null);
1911	>	else
1912	>	p = null;
1913	>	V pv = (p == null) ? null : p.val;
1914	>	val = remappingFunction.apply(key, pv);
1915	>	if (val != null) {
1916	>	if (p != null)
1917	>	p.val = val;
1918	>	else {
1919	>	delta = 1;
1920	>	t.putTreeVal(h, key, val);
1921	>	}
1922	>	}
1923	>	else if (p != null) {
1924	>	delta = -1;
1925	>	if (t.removeTreeNode(p))
1926	>	setTabAt(tab, i, untreeify(t.first));
1927	>	}
1928	>	}
1929	>	else if (f instanceof ReservationNode)
1930	>	throw new IllegalStateException("Recursive update");
1931	>	}
1932	>	}
1933	>	if (binCount != 0) {
1934	>	if (binCount >= TREEIFY_THRESHOLD)
1935	>	treeifyBin(tab, i);
1936	>	break;
1937	>	}
1938		}
1939		}
1940	<	return false;
1940	>	if (delta != 0)
1941	>	addCount((long)delta, binCount);
1942	>	return val;
1943		}
1944
1945		/**
1946	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1947	<	* specified value. Note: This method requires a full internal
1948	<	* traversal of the hash table, and so is much slower than
1949	<	* method <tt>containsKey</tt>.
1946	>	* If the specified key is not already associated with a
1947	>	* (non-null) value, associates it with the given value.
1948	>	* Otherwise, replaces the value with the results of the given
1949	>	* remapping function, or removes if {@code null}. The entire
1950	>	* method invocation is performed atomically.  Some attempted
1951	>	* update operations on this map by other threads may be blocked
1952	>	* while computation is in progress, so the computation should be
1953	>	* short and simple, and must not attempt to update any other
1954	>	* mappings of this Map.
1955		*
1956	<	* @param value value whose presence in this map is to be tested
1957	<	* @return <tt>true</tt> if this map maps one or more keys to the
1958	<	*         specified value
1959	<	* @throws NullPointerException if the specified value is null
1956	>	* @param key key with which the specified value is to be associated
1957	>	* @param value the value to use if absent
1958	>	* @param remappingFunction the function to recompute a value if present
1959	>	* @return the new value associated with the specified key, or null if none
1960	>	* @throws NullPointerException if the specified key or the
1961	>	*         remappingFunction is null
1962	>	* @throws RuntimeException or Error if the remappingFunction does so,
1963	>	*         in which case the mapping is unchanged
1964		*/
1965	<	public boolean containsValue(Object value) {
1966	<	// Same idea as size()
949	<	if (value == null)
1965	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1966	>	if (key == null || value == null || remappingFunction == null)
1967		throw new NullPointerException();
1968	<	final Segment<K,V>[] segments = this.segments;
1969	<	boolean found = false;
1970	<	long last = 0L;   // previous sum
1971	<	int retries = -1;
1972	<	try {
1973	<	outer: for (;;) {
1974	<	if (retries++ == RETRIES_BEFORE_LOCK) {
1975	<	for (int j = 0; j < segments.length; ++j)
1976	<	ensureSegment(j).lock(); // force creation
1977	<	}
1978	<	long sum = 0L;
1979	<	for (int j = 0; j < segments.length; ++j) {
1980	<	HashEntry<K,V>[] tab;
1981	<	Segment<K,V> seg = segmentAt(segments, j);
1982	<	if (seg != null && (tab = seg.table) != null) {
1983	<	for (int i = 0 ; i < tab.length; i++) {
1984	<	HashEntry<K,V> e;
1985	<	for (e = entryAt(tab, i); e != null; e = e.next) {
1986	<	V v = e.value;
1987	<	if (v != null && value.equals(v)) {
1988	<	found = true;
1989	<	break outer;
1968	>	int h = spread(key.hashCode());
1969	>	V val = null;
1970	>	int delta = 0;
1971	>	int binCount = 0;
1972	>	for (Node<K,V>[] tab = table;;) {
1973	>	Node<K,V> f; int n, i, fh;
1974	>	if (tab == null || (n = tab.length) == 0)
1975	>	tab = initTable();
1976	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1977	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1978	>	delta = 1;
1979	>	val = value;
1980	>	break;
1981	>	}
1982	>	}
1983	>	else if ((fh = f.hash) == MOVED)
1984	>	tab = helpTransfer(tab, f);
1985	>	else {
1986	>	synchronized (f) {
1987	>	if (tabAt(tab, i) == f) {
1988	>	if (fh >= 0) {
1989	>	binCount = 1;
1990	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1991	>	K ek;
1992	>	if (e.hash == h &&
1993	>	((ek = e.key) == key ||
1994	>	(ek != null && key.equals(ek)))) {
1995	>	val = remappingFunction.apply(e.val, value);
1996	>	if (val != null)
1997	>	e.val = val;
1998	>	else {
1999	>	delta = -1;
2000	>	Node<K,V> en = e.next;
2001	>	if (pred != null)
2002	>	pred.next = en;
2003	>	else
2004	>	setTabAt(tab, i, en);
2005	>	}
2006	>	break;
2007	>	}
2008	>	pred = e;
2009	>	if ((e = e.next) == null) {
2010	>	delta = 1;
2011	>	val = value;
2012	>	pred.next =
2013	>	new Node<K,V>(h, key, val, null);
2014	>	break;
2015		}
2016		}
2017		}
2018	<	sum += seg.modCount;
2018	>	else if (f instanceof TreeBin) {
2019	>	binCount = 2;
2020	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2021	>	TreeNode<K,V> r = t.root;
2022	>	TreeNode<K,V> p = (r == null) ? null :
2023	>	r.findTreeNode(h, key, null);
2024	>	val = (p == null) ? value :
2025	>	remappingFunction.apply(p.val, value);
2026	>	if (val != null) {
2027	>	if (p != null)
2028	>	p.val = val;
2029	>	else {
2030	>	delta = 1;
2031	>	t.putTreeVal(h, key, val);
2032	>	}
2033	>	}
2034	>	else if (p != null) {
2035	>	delta = -1;
2036	>	if (t.removeTreeNode(p))
2037	>	setTabAt(tab, i, untreeify(t.first));
2038	>	}
2039	>	}
2040	>	else if (f instanceof ReservationNode)
2041	>	throw new IllegalStateException("Recursive update");
2042		}
2043		}
2044	<	if (retries > 0 && sum == last)
2044	>	if (binCount != 0) {
2045	>	if (binCount >= TREEIFY_THRESHOLD)
2046	>	treeifyBin(tab, i);
2047		break;
2048	<	last = sum;
982	<	}
983	<	} finally {
984	<	if (retries > RETRIES_BEFORE_LOCK) {
985	<	for (int j = 0; j < segments.length; ++j)
986	<	segmentAt(segments, j).unlock();
2048	>	}
2049		}
2050		}
2051	<	return found;
2051	>	if (delta != 0)
2052	>	addCount((long)delta, binCount);
2053	>	return val;
2054		}
2055
2056	+	// Hashtable legacy methods
2057	+
2058		/**
2059		* Legacy method testing if some key maps into the specified value
2060	<	* in this table.  This method is identical in functionality to
2061	<	* {@link #containsValue}, and exists solely to ensure
2060	>	* in this table.
2061	>	*
2062	>	* @deprecated This method is identical in functionality to
2063	>	* {@link #containsValue(Object)}, and exists solely to ensure
2064		* full compatibility with class {@link java.util.Hashtable},
2065		* which supported this method prior to introduction of the
2066		* Java Collections framework.
2067		*
2068		* @param  value a value to search for
2069	<	* @return <tt>true</tt> if and only if some key maps to the
2070	<	*         <tt>value</tt> argument in this table as
2071	<	*         determined by the <tt>equals</tt> method;
2072	<	*         <tt>false</tt> otherwise
2069	>	* @return {@code true} if and only if some key maps to the
2070	>	*         {@code value} argument in this table as
2071	>	*         determined by the {@code equals} method;
2072	>	*         {@code false} otherwise
2073		* @throws NullPointerException if the specified value is null
2074		*/
2075	+	@Deprecated
2076		public boolean contains(Object value) {
2077		return containsValue(value);
2078		}
2079
2080		/**
2081	<	* Maps the specified key to the specified value in this table.
1013	<	* Neither the key nor the value can be null.
1014	<	*
1015	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1016	<	* with a key that is equal to the original key.
2081	>	* Returns an enumeration of the keys in this table.
2082		*
2083	<	* @param key key with which the specified value is to be associated
2084	<	* @param value value to be associated with the specified key
1020	<	* @return the previous value associated with <tt>key</tt>, or
1021	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1022	<	* @throws NullPointerException if the specified key or value is null
2083	>	* @return an enumeration of the keys in this table
2084	>	* @see #keySet()
2085		*/
2086	<	@SuppressWarnings("unchecked")
2087	<	public V put(K key, V value) {
2088	<	Segment<K,V> s;
2089	<	if (value == null)
1028	<	throw new NullPointerException();
1029	<	int hash = hash(key.hashCode());
1030	<	int j = (hash >>> segmentShift) & segmentMask;
1031	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1032	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1033	<	s = ensureSegment(j);
1034	<	return s.put(key, hash, value, false);
2086	>	public Enumeration<K> keys() {
2087	>	Node<K,V>[] t;
2088	>	int f = (t = table) == null ? 0 : t.length;
2089	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2090		}
2091
2092		/**
2093	<	* {@inheritDoc}
2093	>	* Returns an enumeration of the values in this table.
2094		*
2095	<	* @return the previous value associated with the specified key,
2096	<	*         or <tt>null</tt> if there was no mapping for the key
1042	<	* @throws NullPointerException if the specified key or value is null
2095	>	* @return an enumeration of the values in this table
2096	>	* @see #values()
2097		*/
2098	<	@SuppressWarnings("unchecked")
2099	<	public V putIfAbsent(K key, V value) {
2100	<	Segment<K,V> s;
2101	<	if (value == null)
1048	<	throw new NullPointerException();
1049	<	int hash = hash(key.hashCode());
1050	<	int j = (hash >>> segmentShift) & segmentMask;
1051	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1052	<	(segments, (j << SSHIFT) + SBASE)) == null)
1053	<	s = ensureSegment(j);
1054	<	return s.put(key, hash, value, true);
2098	>	public Enumeration<V> elements() {
2099	>	Node<K,V>[] t;
2100	>	int f = (t = table) == null ? 0 : t.length;
2101	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2102		}
2103
2104	+	// ConcurrentHashMap-only methods
2105	+
2106		/**
2107	<	* Copies all of the mappings from the specified map to this one.
2108	<	* These mappings replace any mappings that this map had for any of the
2109	<	* keys currently in the specified map.
2107	>	* Returns the number of mappings. This method should be used
2108	>	* instead of {@link #size} because a ConcurrentHashMap may
2109	>	* contain more mappings than can be represented as an int. The
2110	>	* value returned is an estimate; the actual count may differ if
2111	>	* there are concurrent insertions or removals.
2112		*
2113	<	* @param m mappings to be stored in this map
2113	>	* @return the number of mappings
2114	>	* @since 1.8
2115		*/
2116	<	public void putAll(Map<? extends K, ? extends V> m) {
2117	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2118	<	put(e.getKey(), e.getValue());
2116	>	public long mappingCount() {
2117	>	long n = sumCount();
2118	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2119		}
2120
2121		/**
2122	<	* Removes the key (and its corresponding value) from this map.
2123	<	* This method does nothing if the key is not in the map.
2122	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2123	>	* from the given type to {@code Boolean.TRUE}.
2124		*
2125	<	* @param  key the key that needs to be removed
2126	<	* @return the previous value associated with <tt>key</tt>, or
2127	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1076	<	* @throws NullPointerException if the specified key is null
2125	>	* @param <K> the element type of the returned set
2126	>	* @return the new set
2127	>	* @since 1.8
2128		*/
2129	<	public V remove(Object key) {
2130	<	int hash = hash(key.hashCode());
2131	<	Segment<K,V> s = segmentForHash(hash);
1081	<	return s == null ? null : s.remove(key, hash, null);
2129	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2130	>	return new KeySetView<K,Boolean>
2131	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2132		}
2133
2134		/**
2135	<	* {@inheritDoc}
2135	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2136	>	* from the given type to {@code Boolean.TRUE}.
2137		*
2138	<	* @throws NullPointerException if the specified key is null
2138	>	* @param initialCapacity The implementation performs internal
2139	>	* sizing to accommodate this many elements.
2140	>	* @param <K> the element type of the returned set
2141	>	* @return the new set
2142	>	* @throws IllegalArgumentException if the initial capacity of
2143	>	* elements is negative
2144	>	* @since 1.8
2145		*/
2146	<	public boolean remove(Object key, Object value) {
2147	<	int hash = hash(key.hashCode());
2148	<	Segment<K,V> s;
1092	<	return value != null && (s = segmentForHash(hash)) != null &&
1093	<	s.remove(key, hash, value) != null;
2146	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2147	>	return new KeySetView<K,Boolean>
2148	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2149		}
2150
2151		/**
2152	<	* {@inheritDoc}
2152	>	* Returns a {@link Set} view of the keys in this map, using the
2153	>	* given common mapped value for any additions (i.e., {@link
2154	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2155	>	* This is of course only appropriate if it is acceptable to use
2156	>	* the same value for all additions from this view.
2157		*
2158	<	* @throws NullPointerException if any of the arguments are null
2158	>	* @param mappedValue the mapped value to use for any additions
2159	>	* @return the set view
2160	>	* @throws NullPointerException if the mappedValue is null
2161		*/
2162	<	public boolean replace(K key, V oldValue, V newValue) {
2163	<	int hash = hash(key.hashCode());
1103	<	if (oldValue == null || newValue == null)
2162	>	public KeySetView<K,V> keySet(V mappedValue) {
2163	>	if (mappedValue == null)
2164		throw new NullPointerException();
2165	<	Segment<K,V> s = segmentForHash(hash);
1106	<	return s != null && s.replace(key, hash, oldValue, newValue);
2165	>	return new KeySetView<K,V>(this, mappedValue);
2166		}
2167
2168	+	/* ---------------- Special Nodes -------------- */
2169	+
2170		/**
2171	<	* {@inheritDoc}
1111	<	*
1112	<	* @return the previous value associated with the specified key,
1113	<	*         or <tt>null</tt> if there was no mapping for the key
1114	<	* @throws NullPointerException if the specified key or value is null
2171	>	* A node inserted at head of bins during transfer operations.
2172		*/
2173	<	public V replace(K key, V value) {
2174	<	int hash = hash(key.hashCode());
2175	<	if (value == null)
2176	<	throw new NullPointerException();
2177	<	Segment<K,V> s = segmentForHash(hash);
2178	<	return s == null ? null : s.replace(key, hash, value);
2173	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2174	>	final Node<K,V>[] nextTable;
2175	>	ForwardingNode(Node<K,V>[] tab) {
2176	>	super(MOVED, null, null, null);
2177	>	this.nextTable = tab;
2178	>	}
2179	>
2180	>	Node<K,V> find(int h, Object k) {
2181	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2182	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2183	>	Node<K,V> e; int n;
2184	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2185	>	(e = tabAt(tab, (n - 1) & h)) == null)
2186	>	return null;
2187	>	for (;;) {
2188	>	int eh; K ek;
2189	>	if ((eh = e.hash) == h &&
2190	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2191	>	return e;
2192	>	if (eh < 0) {
2193	>	if (e instanceof ForwardingNode) {
2194	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2195	>	continue outer;
2196	>	}
2197	>	else
2198	>	return e.find(h, k);
2199	>	}
2200	>	if ((e = e.next) == null)
2201	>	return null;
2202	>	}
2203	>	}
2204	>	}
2205		}
2206
2207		/**
2208	<	* Removes all of the mappings from this map.
2208	>	* A place-holder node used in computeIfAbsent and compute
2209		*/
2210	<	public void clear() {
2211	<	final Segment<K,V>[] segments = this.segments;
2212	<	for (int j = 0; j < segments.length; ++j) {
2213	<	Segment<K,V> s = segmentAt(segments, j);
2214	<	if (s != null)
2215	<	s.clear();
2210	>	static final class ReservationNode<K,V> extends Node<K,V> {
2211	>	ReservationNode() {
2212	>	super(RESERVED, null, null, null);
2213	>	}
2214	>
2215	>	Node<K,V> find(int h, Object k) {
2216	>	return null;
2217		}
2218		}
2219
2220	+	/* ---------------- Table Initialization and Resizing -------------- */
2221	+
2222		/**
2223	<	* Returns a {@link Set} view of the keys contained in this map.
2224	<	* The set is backed by the map, so changes to the map are
2225	<	* reflected in the set, and vice-versa.  The set supports element
2226	<	* removal, which removes the corresponding mapping from this map,
2227	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1142	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1143	<	* operations.  It does not support the <tt>add</tt> or
1144	<	* <tt>addAll</tt> operations.
1145	<	*
1146	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1147	<	* that will never throw {@link ConcurrentModificationException},
1148	<	* and guarantees to traverse elements as they existed upon
1149	<	* construction of the iterator, and may (but is not guaranteed to)
1150	<	* reflect any modifications subsequent to construction.
1151	<	*/
1152	<	public Set<K> keySet() {
1153	<	Set<K> ks = keySet;
1154	<	return (ks != null) ? ks : (keySet = new KeySet());
2223	>	* Returns the stamp bits for resizing a table of size n.
2224	>	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2225	>	*/
2226	>	static final int resizeStamp(int n) {
2227	>	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2228		}
2229
2230		/**
2231	<	* Returns a {@link Collection} view of the values contained in this map.
1159	<	* The collection is backed by the map, so changes to the map are
1160	<	* reflected in the collection, and vice-versa.  The collection
1161	<	* supports element removal, which removes the corresponding
1162	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1163	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1164	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1165	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1166	<	*
1167	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1168	<	* that will never throw {@link ConcurrentModificationException},
1169	<	* and guarantees to traverse elements as they existed upon
1170	<	* construction of the iterator, and may (but is not guaranteed to)
1171	<	* reflect any modifications subsequent to construction.
2231	>	* Initializes table, using the size recorded in sizeCtl.
2232		*/
2233	<	public Collection<V> values() {
2234	<	Collection<V> vs = values;
2235	<	return (vs != null) ? vs : (values = new Values());
2233	>	private final Node<K,V>[] initTable() {
2234	>	Node<K,V>[] tab; int sc;
2235	>	while ((tab = table) == null || tab.length == 0) {
2236	>	if ((sc = sizeCtl) < 0)
2237	>	Thread.yield(); // lost initialization race; just spin
2238	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2239	>	try {
2240	>	if ((tab = table) == null || tab.length == 0) {
2241	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2242	>	@SuppressWarnings("unchecked")
2243	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2244	>	table = tab = nt;
2245	>	sc = n - (n >>> 2);
2246	>	}
2247	>	} finally {
2248	>	sizeCtl = sc;
2249	>	}
2250	>	break;
2251	>	}
2252	>	}
2253	>	return tab;
2254		}
2255
2256		/**
2257	<	* Returns a {@link Set} view of the mappings contained in this map.
2258	<	* The set is backed by the map, so changes to the map are
2259	<	* reflected in the set, and vice-versa.  The set supports element
2260	<	* removal, which removes the corresponding mapping from the map,
2261	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2262	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2263	<	* operations.  It does not support the <tt>add</tt> or
2264	<	* <tt>addAll</tt> operations.
1187	<	*
1188	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1189	<	* that will never throw {@link ConcurrentModificationException},
1190	<	* and guarantees to traverse elements as they existed upon
1191	<	* construction of the iterator, and may (but is not guaranteed to)
1192	<	* reflect any modifications subsequent to construction.
2257	>	* Adds to count, and if table is too small and not already
2258	>	* resizing, initiates transfer. If already resizing, helps
2259	>	* perform transfer if work is available.  Rechecks occupancy
2260	>	* after a transfer to see if another resize is already needed
2261	>	* because resizings are lagging additions.
2262	>	*
2263	>	* @param x the count to add
2264	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2265		*/
2266	<	public Set<Map.Entry<K,V>> entrySet() {
2267	<	Set<Map.Entry<K,V>> es = entrySet;
2268	<	return (es != null) ? es : (entrySet = new EntrySet());
2266	>	private final void addCount(long x, int check) {
2267	>	CounterCell[] as; long b, s;
2268	>	if ((as = counterCells) != null ||
2269	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2270	>	CounterCell a; long v; int m;
2271	>	boolean uncontended = true;
2272	>	if (as == null || (m = as.length - 1) < 0 ||
2273	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2274	>	!(uncontended =
2275	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2276	>	fullAddCount(x, uncontended);
2277	>	return;
2278	>	}
2279	>	if (check <= 1)
2280	>	return;
2281	>	s = sumCount();
2282	>	}
2283	>	if (check >= 0) {
2284	>	Node<K,V>[] tab, nt; int n, sc;
2285	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2286	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2287	>	int rs = resizeStamp(n);
2288	>	if (sc < 0) {
2289	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2290	>	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2291	>	transferIndex <= 0)
2292	>	break;
2293	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2294	>	transfer(tab, nt);
2295	>	}
2296	>	else if (U.compareAndSwapInt(this, SIZECTL, sc,
2297	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2298	>	transfer(tab, null);
2299	>	s = sumCount();
2300	>	}
2301	>	}
2302		}
2303
2304		/**
2305	<	* Returns an enumeration of the keys in this table.
1201	<	*
1202	<	* @return an enumeration of the keys in this table
1203	<	* @see #keySet()
2305	>	* Helps transfer if a resize is in progress.
2306		*/
2307	<	public Enumeration<K> keys() {
2308	<	return new KeyIterator();
2307	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2308	>	Node<K,V>[] nextTab; int sc;
2309	>	if (tab != null && (f instanceof ForwardingNode) &&
2310	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2311	>	int rs = resizeStamp(tab.length);
2312	>	while (nextTab == nextTable && table == tab &&
2313	>	(sc = sizeCtl) < 0) {
2314	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2315	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2316	>	break;
2317	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2318	>	transfer(tab, nextTab);
2319	>	break;
2320	>	}
2321	>	}
2322	>	return nextTab;
2323	>	}
2324	>	return table;
2325		}
2326
2327		/**
2328	<	* Returns an enumeration of the values in this table.
2328	>	* Tries to presize table to accommodate the given number of elements.
2329		*
2330	<	* @return an enumeration of the values in this table
1213	<	* @see #values()
2330	>	* @param size number of elements (doesn't need to be perfectly accurate)
2331		*/
2332	<	public Enumeration<V> elements() {
2333	<	return new ValueIterator();
2332	>	private final void tryPresize(int size) {
2333	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2334	>	tableSizeFor(size + (size >>> 1) + 1);
2335	>	int sc;
2336	>	while ((sc = sizeCtl) >= 0) {
2337	>	Node<K,V>[] tab = table; int n;
2338	>	if (tab == null || (n = tab.length) == 0) {
2339	>	n = (sc > c) ? sc : c;
2340	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2341	>	try {
2342	>	if (table == tab) {
2343	>	@SuppressWarnings("unchecked")
2344	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2345	>	table = nt;
2346	>	sc = n - (n >>> 2);
2347	>	}
2348	>	} finally {
2349	>	sizeCtl = sc;
2350	>	}
2351	>	}
2352	>	}
2353	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2354	>	break;
2355	>	else if (tab == table) {
2356	>	int rs = resizeStamp(n);
2357	>	if (U.compareAndSwapInt(this, SIZECTL, sc,
2358	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2359	>	transfer(tab, null);
2360	>	}
2361	>	}
2362		}
2363
2364	<	/* ---------------- Iterator Support -------------- */
2364	>	/**
2365	>	* Moves and/or copies the nodes in each bin to new table. See
2366	>	* above for explanation.
2367	>	*/
2368	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2369	>	int n = tab.length, stride;
2370	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2371	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2372	>	if (nextTab == null) {            // initiating
2373	>	try {
2374	>	@SuppressWarnings("unchecked")
2375	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2376	>	nextTab = nt;
2377	>	} catch (Throwable ex) {      // try to cope with OOME
2378	>	sizeCtl = Integer.MAX_VALUE;
2379	>	return;
2380	>	}
2381	>	nextTable = nextTab;
2382	>	transferIndex = n;
2383	>	}
2384	>	int nextn = nextTab.length;
2385	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2386	>	boolean advance = true;
2387	>	boolean finishing = false; // to ensure sweep before committing nextTab
2388	>	for (int i = 0, bound = 0;;) {
2389	>	Node<K,V> f; int fh;
2390	>	while (advance) {
2391	>	int nextIndex, nextBound;
2392	>	if (--i >= bound || finishing)
2393	>	advance = false;
2394	>	else if ((nextIndex = transferIndex) <= 0) {
2395	>	i = -1;
2396	>	advance = false;
2397	>	}
2398	>	else if (U.compareAndSwapInt
2399	>	(this, TRANSFERINDEX, nextIndex,
2400	>	nextBound = (nextIndex > stride ?
2401	>	nextIndex - stride : 0))) {
2402	>	bound = nextBound;
2403	>	i = nextIndex - 1;
2404	>	advance = false;
2405	>	}
2406	>	}
2407	>	if (i < 0 || i >= n || i + n >= nextn) {
2408	>	int sc;
2409	>	if (finishing) {
2410	>	nextTable = null;
2411	>	table = nextTab;
2412	>	sizeCtl = (n << 1) - (n >>> 1);
2413	>	return;
2414	>	}
2415	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2416	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2417	>	return;
2418	>	finishing = advance = true;
2419	>	i = n; // recheck before commit
2420	>	}
2421	>	}
2422	>	else if ((f = tabAt(tab, i)) == null)
2423	>	advance = casTabAt(tab, i, null, fwd);
2424	>	else if ((fh = f.hash) == MOVED)
2425	>	advance = true; // already processed
2426	>	else {
2427	>	synchronized (f) {
2428	>	if (tabAt(tab, i) == f) {
2429	>	Node<K,V> ln, hn;
2430	>	if (fh >= 0) {
2431	>	int runBit = fh & n;
2432	>	Node<K,V> lastRun = f;
2433	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2434	>	int b = p.hash & n;
2435	>	if (b != runBit) {
2436	>	runBit = b;
2437	>	lastRun = p;
2438	>	}
2439	>	}
2440	>	if (runBit == 0) {
2441	>	ln = lastRun;
2442	>	hn = null;
2443	>	}
2444	>	else {
2445	>	hn = lastRun;
2446	>	ln = null;
2447	>	}
2448	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2449	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2450	>	if ((ph & n) == 0)
2451	>	ln = new Node<K,V>(ph, pk, pv, ln);
2452	>	else
2453	>	hn = new Node<K,V>(ph, pk, pv, hn);
2454	>	}
2455	>	setTabAt(nextTab, i, ln);
2456	>	setTabAt(nextTab, i + n, hn);
2457	>	setTabAt(tab, i, fwd);
2458	>	advance = true;
2459	>	}
2460	>	else if (f instanceof TreeBin) {
2461	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2462	>	TreeNode<K,V> lo = null, loTail = null;
2463	>	TreeNode<K,V> hi = null, hiTail = null;
2464	>	int lc = 0, hc = 0;
2465	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2466	>	int h = e.hash;
2467	>	TreeNode<K,V> p = new TreeNode<K,V>
2468	>	(h, e.key, e.val, null, null);
2469	>	if ((h & n) == 0) {
2470	>	if ((p.prev = loTail) == null)
2471	>	lo = p;
2472	>	else
2473	>	loTail.next = p;
2474	>	loTail = p;
2475	>	++lc;
2476	>	}
2477	>	else {
2478	>	if ((p.prev = hiTail) == null)
2479	>	hi = p;
2480	>	else
2481	>	hiTail.next = p;
2482	>	hiTail = p;
2483	>	++hc;
2484	>	}
2485	>	}
2486	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2487	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2488	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2489	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2490	>	setTabAt(nextTab, i, ln);
2491	>	setTabAt(nextTab, i + n, hn);
2492	>	setTabAt(tab, i, fwd);
2493	>	advance = true;
2494	>	}
2495	>	}
2496	>	}
2497	>	}
2498	>	}
2499	>	}
2500
2501	<	abstract class HashIterator {
1222	<	int nextSegmentIndex;
1223	<	int nextTableIndex;
1224	<	HashEntry<K,V>[] currentTable;
1225	<	HashEntry<K, V> nextEntry;
1226	<	HashEntry<K, V> lastReturned;
2501	>	/* ---------------- Counter support -------------- */
2502
2503	<	HashIterator() {
2504	<	nextSegmentIndex = segments.length - 1;
2505	<	nextTableIndex = -1;
2506	<	advance();
2503	>	/**
2504	>	* A padded cell for distributing counts.  Adapted from LongAdder
2505	>	* and Striped64.  See their internal docs for explanation.
2506	>	*/
2507	>	@sun.misc.Contended static final class CounterCell {
2508	>	volatile long value;
2509	>	CounterCell(long x) { value = x; }
2510	>	}
2511	>
2512	>	final long sumCount() {
2513	>	CounterCell[] as = counterCells; CounterCell a;
2514	>	long sum = baseCount;
2515	>	if (as != null) {
2516	>	for (int i = 0; i < as.length; ++i) {
2517	>	if ((a = as[i]) != null)
2518	>	sum += a.value;
2519	>	}
2520	>	}
2521	>	return sum;
2522	>	}
2523	>
2524	>	// See LongAdder version for explanation
2525	>	private final void fullAddCount(long x, boolean wasUncontended) {
2526	>	int h;
2527	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2528	>	ThreadLocalRandom.localInit();      // force initialization
2529	>	h = ThreadLocalRandom.getProbe();
2530	>	wasUncontended = true;
2531	>	}
2532	>	boolean collide = false;                // True if last slot nonempty
2533	>	for (;;) {
2534	>	CounterCell[] as; CounterCell a; int n; long v;
2535	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2536	>	if ((a = as[(n - 1) & h]) == null) {
2537	>	if (cellsBusy == 0) {            // Try to attach new Cell
2538	>	CounterCell r = new CounterCell(x); // Optimistic create
2539	>	if (cellsBusy == 0 &&
2540	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2541	>	boolean created = false;
2542	>	try {               // Recheck under lock
2543	>	CounterCell[] rs; int m, j;
2544	>	if ((rs = counterCells) != null &&
2545	>	(m = rs.length) > 0 &&
2546	>	rs[j = (m - 1) & h] == null) {
2547	>	rs[j] = r;
2548	>	created = true;
2549	>	}
2550	>	} finally {
2551	>	cellsBusy = 0;
2552	>	}
2553	>	if (created)
2554	>	break;
2555	>	continue;           // Slot is now non-empty
2556	>	}
2557	>	}
2558	>	collide = false;
2559	>	}
2560	>	else if (!wasUncontended)       // CAS already known to fail
2561	>	wasUncontended = true;      // Continue after rehash
2562	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2563	>	break;
2564	>	else if (counterCells != as || n >= NCPU)
2565	>	collide = false;            // At max size or stale
2566	>	else if (!collide)
2567	>	collide = true;
2568	>	else if (cellsBusy == 0 &&
2569	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2570	>	try {
2571	>	if (counterCells == as) {// Expand table unless stale
2572	>	CounterCell[] rs = new CounterCell[n << 1];
2573	>	for (int i = 0; i < n; ++i)
2574	>	rs[i] = as[i];
2575	>	counterCells = rs;
2576	>	}
2577	>	} finally {
2578	>	cellsBusy = 0;
2579	>	}
2580	>	collide = false;
2581	>	continue;                   // Retry with expanded table
2582	>	}
2583	>	h = ThreadLocalRandom.advanceProbe(h);
2584	>	}
2585	>	else if (cellsBusy == 0 && counterCells == as &&
2586	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2587	>	boolean init = false;
2588	>	try {                           // Initialize table
2589	>	if (counterCells == as) {
2590	>	CounterCell[] rs = new CounterCell[2];
2591	>	rs[h & 1] = new CounterCell(x);
2592	>	counterCells = rs;
2593	>	init = true;
2594	>	}
2595	>	} finally {
2596	>	cellsBusy = 0;
2597	>	}
2598	>	if (init)
2599	>	break;
2600	>	}
2601	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2602	>	break;                          // Fall back on using base
2603	>	}
2604	>	}
2605	>
2606	>	/* ---------------- Conversion from/to TreeBins -------------- */
2607	>
2608	>	/**
2609	>	* Replaces all linked nodes in bin at given index unless table is
2610	>	* too small, in which case resizes instead.
2611	>	*/
2612	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2613	>	Node<K,V> b; int n;
2614	>	if (tab != null) {
2615	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2616	>	tryPresize(n << 1);
2617	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2618	>	synchronized (b) {
2619	>	if (tabAt(tab, index) == b) {
2620	>	TreeNode<K,V> hd = null, tl = null;
2621	>	for (Node<K,V> e = b; e != null; e = e.next) {
2622	>	TreeNode<K,V> p =
2623	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2624	>	null, null);
2625	>	if ((p.prev = tl) == null)
2626	>	hd = p;
2627	>	else
2628	>	tl.next = p;
2629	>	tl = p;
2630	>	}
2631	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2632	>	}
2633	>	}
2634	>	}
2635	>	}
2636	>	}
2637	>
2638	>	/**
2639	>	* Returns a list on non-TreeNodes replacing those in given list.
2640	>	*/
2641	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2642	>	Node<K,V> hd = null, tl = null;
2643	>	for (Node<K,V> q = b; q != null; q = q.next) {
2644	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2645	>	if (tl == null)
2646	>	hd = p;
2647	>	else
2648	>	tl.next = p;
2649	>	tl = p;
2650	>	}
2651	>	return hd;
2652	>	}
2653	>
2654	>	/* ---------------- TreeNodes -------------- */
2655	>
2656	>	/**
2657	>	* Nodes for use in TreeBins
2658	>	*/
2659	>	static final class TreeNode<K,V> extends Node<K,V> {
2660	>	TreeNode<K,V> parent;  // red-black tree links
2661	>	TreeNode<K,V> left;
2662	>	TreeNode<K,V> right;
2663	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2664	>	boolean red;
2665	>
2666	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2667	>	TreeNode<K,V> parent) {
2668	>	super(hash, key, val, next);
2669	>	this.parent = parent;
2670	>	}
2671	>
2672	>	Node<K,V> find(int h, Object k) {
2673	>	return findTreeNode(h, k, null);
2674		}
2675
2676		/**
2677	<	* Sets nextEntry to first node of next non-empty table
2678	<	* (in backwards order, to simplify checks).
2677	>	* Returns the TreeNode (or null if not found) for the given key
2678	>	* starting at given root.
2679		*/
2680	<	final void advance() {
2681	<	for (;;) {
2682	<	if (nextTableIndex >= 0) {
2683	<	if ((nextEntry = entryAt(currentTable,
2684	<	nextTableIndex--)) != null)
2685	<	break;
2680	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2681	>	if (k != null) {
2682	>	TreeNode<K,V> p = this;
2683	>	do {
2684	>	int ph, dir; K pk; TreeNode<K,V> q;
2685	>	TreeNode<K,V> pl = p.left, pr = p.right;
2686	>	if ((ph = p.hash) > h)
2687	>	p = pl;
2688	>	else if (ph < h)
2689	>	p = pr;
2690	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2691	>	return p;
2692	>	else if (pl == null)
2693	>	p = pr;
2694	>	else if (pr == null)
2695	>	p = pl;
2696	>	else if ((kc != null ||
2697	>	(kc = comparableClassFor(k)) != null) &&
2698	>	(dir = compareComparables(kc, k, pk)) != 0)
2699	>	p = (dir < 0) ? pl : pr;
2700	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2701	>	return q;
2702	>	else
2703	>	p = pl;
2704	>	} while (p != null);
2705	>	}
2706	>	return null;
2707	>	}
2708	>	}
2709	>
2710	>	/* ---------------- TreeBins -------------- */
2711	>
2712	>	/**
2713	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2714	>	* keys or values, but instead point to list of TreeNodes and
2715	>	* their root. They also maintain a parasitic read-write lock
2716	>	* forcing writers (who hold bin lock) to wait for readers (who do
2717	>	* not) to complete before tree restructuring operations.
2718	>	*/
2719	>	static final class TreeBin<K,V> extends Node<K,V> {
2720	>	TreeNode<K,V> root;
2721	>	volatile TreeNode<K,V> first;
2722	>	volatile Thread waiter;
2723	>	volatile int lockState;
2724	>	// values for lockState
2725	>	static final int WRITER = 1; // set while holding write lock
2726	>	static final int WAITER = 2; // set when waiting for write lock
2727	>	static final int READER = 4; // increment value for setting read lock
2728	>
2729	>	/**
2730	>	* Tie-breaking utility for ordering insertions when equal
2731	>	* hashCodes and non-comparable. We don't require a total
2732	>	* order, just a consistent insertion rule to maintain
2733	>	* equivalence across rebalancings. Tie-breaking further than
2734	>	* necessary simplifies testing a bit.
2735	>	*/
2736	>	static int tieBreakOrder(Object a, Object b) {
2737	>	int d;
2738	>	if (a == null || b == null ||
2739	>	(d = a.getClass().getName().
2740	>	compareTo(b.getClass().getName())) == 0)
2741	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2742	>	-1 : 1);
2743	>	return d;
2744	>	}
2745	>
2746	>	/**
2747	>	* Creates bin with initial set of nodes headed by b.
2748	>	*/
2749	>	TreeBin(TreeNode<K,V> b) {
2750	>	super(TREEBIN, null, null, null);
2751	>	this.first = b;
2752	>	TreeNode<K,V> r = null;
2753	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2754	>	next = (TreeNode<K,V>)x.next;
2755	>	x.left = x.right = null;
2756	>	if (r == null) {
2757	>	x.parent = null;
2758	>	x.red = false;
2759	>	r = x;
2760		}
2761	<	else if (nextSegmentIndex >= 0) {
2762	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2763	<	if (seg != null && (currentTable = seg.table) != null)
2764	<	nextTableIndex = currentTable.length - 1;
2761	>	else {
2762	>	K k = x.key;
2763	>	int h = x.hash;
2764	>	Class<?> kc = null;
2765	>	for (TreeNode<K,V> p = r;;) {
2766	>	int dir, ph;
2767	>	K pk = p.key;
2768	>	if ((ph = p.hash) > h)
2769	>	dir = -1;
2770	>	else if (ph < h)
2771	>	dir = 1;
2772	>	else if ((kc == null &&
2773	>	(kc = comparableClassFor(k)) == null) ||
2774	>	(dir = compareComparables(kc, k, pk)) == 0)
2775	>	dir = tieBreakOrder(k, pk);
2776	>	TreeNode<K,V> xp = p;
2777	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2778	>	x.parent = xp;
2779	>	if (dir <= 0)
2780	>	xp.left = x;
2781	>	else
2782	>	xp.right = x;
2783	>	r = balanceInsertion(r, x);
2784	>	break;
2785	>	}
2786	>	}
2787		}
2788	<	else
2788	>	}
2789	>	this.root = r;
2790	>	assert checkInvariants(root);
2791	>	}
2792	>
2793	>	/**
2794	>	* Acquires write lock for tree restructuring.
2795	>	*/
2796	>	private final void lockRoot() {
2797	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2798	>	contendedLock(); // offload to separate method
2799	>	}
2800	>
2801	>	/**
2802	>	* Releases write lock for tree restructuring.
2803	>	*/
2804	>	private final void unlockRoot() {
2805	>	lockState = 0;
2806	>	}
2807	>
2808	>	/**
2809	>	* Possibly blocks awaiting root lock.
2810	>	*/
2811	>	private final void contendedLock() {
2812	>	boolean waiting = false;
2813	>	for (int s;;) {
2814	>	if (((s = lockState) & ~WAITER) == 0) {
2815	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2816	>	if (waiting)
2817	>	waiter = null;
2818	>	return;
2819	>	}
2820	>	}
2821	>	else if ((s & WAITER) == 0) {
2822	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2823	>	waiting = true;
2824	>	waiter = Thread.currentThread();
2825	>	}
2826	>	}
2827	>	else if (waiting)
2828	>	LockSupport.park(this);
2829	>	}
2830	>	}
2831	>
2832	>	/**
2833	>	* Returns matching node or null if none. Tries to search
2834	>	* using tree comparisons from root, but continues linear
2835	>	* search when lock not available.
2836	>	*/
2837	>	final Node<K,V> find(int h, Object k) {
2838	>	if (k != null) {
2839	>	for (Node<K,V> e = first; e != null; ) {
2840	>	int s; K ek;
2841	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2842	>	if (e.hash == h &&
2843	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2844	>	return e;
2845	>	e = e.next;
2846	>	}
2847	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2848	>	s + READER)) {
2849	>	TreeNode<K,V> r, p;
2850	>	try {
2851	>	p = ((r = root) == null ? null :
2852	>	r.findTreeNode(h, k, null));
2853	>	} finally {
2854	>	Thread w;
2855	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2856	>	(READER|WAITER) && (w = waiter) != null)
2857	>	LockSupport.unpark(w);
2858	>	}
2859	>	return p;
2860	>	}
2861	>	}
2862	>	}
2863	>	return null;
2864	>	}
2865	>
2866	>	/**
2867	>	* Finds or adds a node.
2868	>	* @return null if added
2869	>	*/
2870	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2871	>	Class<?> kc = null;
2872	>	boolean searched = false;
2873	>	for (TreeNode<K,V> p = root;;) {
2874	>	int dir, ph; K pk;
2875	>	if (p == null) {
2876	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2877	>	break;
2878	>	}
2879	>	else if ((ph = p.hash) > h)
2880	>	dir = -1;
2881	>	else if (ph < h)
2882	>	dir = 1;
2883	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2884	>	return p;
2885	>	else if ((kc == null &&
2886	>	(kc = comparableClassFor(k)) == null) ||
2887	>	(dir = compareComparables(kc, k, pk)) == 0) {
2888	>	if (!searched) {
2889	>	TreeNode<K,V> q, ch;
2890	>	searched = true;
2891	>	if (((ch = p.left) != null &&
2892	>	(q = ch.findTreeNode(h, k, kc)) != null) ||
2893	>	((ch = p.right) != null &&
2894	>	(q = ch.findTreeNode(h, k, kc)) != null))
2895	>	return q;
2896	>	}
2897	>	dir = tieBreakOrder(k, pk);
2898	>	}
2899	>
2900	>	TreeNode<K,V> xp = p;
2901	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2902	>	TreeNode<K,V> x, f = first;
2903	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2904	>	if (f != null)
2905	>	f.prev = x;
2906	>	if (dir <= 0)
2907	>	xp.left = x;
2908	>	else
2909	>	xp.right = x;
2910	>	if (!xp.red)
2911	>	x.red = true;
2912	>	else {
2913	>	lockRoot();
2914	>	try {
2915	>	root = balanceInsertion(root, x);
2916	>	} finally {
2917	>	unlockRoot();
2918	>	}
2919	>	}
2920		break;
2921	+	}
2922		}
2923	+	assert checkInvariants(root);
2924	+	return null;
2925		}
2926
2927	<	final HashEntry<K,V> nextEntry() {
2928	<	HashEntry<K,V> e = nextEntry;
2929	<	if (e == null)
2930	<	throw new NoSuchElementException();
2931	<	lastReturned = e; // cannot assign until after null check
2932	<	if ((nextEntry = e.next) == null)
2933	<	advance();
2934	<	return e;
2927	>	/**
2928	>	* Removes the given node, that must be present before this
2929	>	* call.  This is messier than typical red-black deletion code
2930	>	* because we cannot swap the contents of an interior node
2931	>	* with a leaf successor that is pinned by "next" pointers
2932	>	* that are accessible independently of lock. So instead we
2933	>	* swap the tree linkages.
2934	>	*
2935	>	* @return true if now too small, so should be untreeified
2936	>	*/
2937	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2938	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2939	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2940	>	TreeNode<K,V> r, rl;
2941	>	if (pred == null)
2942	>	first = next;
2943	>	else
2944	>	pred.next = next;
2945	>	if (next != null)
2946	>	next.prev = pred;
2947	>	if (first == null) {
2948	>	root = null;
2949	>	return true;
2950	>	}
2951	>	if ((r = root) == null || r.right == null || // too small
2952	>	(rl = r.left) == null || rl.left == null)
2953	>	return true;
2954	>	lockRoot();
2955	>	try {
2956	>	TreeNode<K,V> replacement;
2957	>	TreeNode<K,V> pl = p.left;
2958	>	TreeNode<K,V> pr = p.right;
2959	>	if (pl != null && pr != null) {
2960	>	TreeNode<K,V> s = pr, sl;
2961	>	while ((sl = s.left) != null) // find successor
2962	>	s = sl;
2963	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2964	>	TreeNode<K,V> sr = s.right;
2965	>	TreeNode<K,V> pp = p.parent;
2966	>	if (s == pr) { // p was s's direct parent
2967	>	p.parent = s;
2968	>	s.right = p;
2969	>	}
2970	>	else {
2971	>	TreeNode<K,V> sp = s.parent;
2972	>	if ((p.parent = sp) != null) {
2973	>	if (s == sp.left)
2974	>	sp.left = p;
2975	>	else
2976	>	sp.right = p;
2977	>	}
2978	>	if ((s.right = pr) != null)
2979	>	pr.parent = s;
2980	>	}
2981	>	p.left = null;
2982	>	if ((p.right = sr) != null)
2983	>	sr.parent = p;
2984	>	if ((s.left = pl) != null)
2985	>	pl.parent = s;
2986	>	if ((s.parent = pp) == null)
2987	>	r = s;
2988	>	else if (p == pp.left)
2989	>	pp.left = s;
2990	>	else
2991	>	pp.right = s;
2992	>	if (sr != null)
2993	>	replacement = sr;
2994	>	else
2995	>	replacement = p;
2996	>	}
2997	>	else if (pl != null)
2998	>	replacement = pl;
2999	>	else if (pr != null)
3000	>	replacement = pr;
3001	>	else
3002	>	replacement = p;
3003	>	if (replacement != p) {
3004	>	TreeNode<K,V> pp = replacement.parent = p.parent;
3005	>	if (pp == null)
3006	>	r = replacement;
3007	>	else if (p == pp.left)
3008	>	pp.left = replacement;
3009	>	else
3010	>	pp.right = replacement;
3011	>	p.left = p.right = p.parent = null;
3012	>	}
3013	>
3014	>	root = (p.red) ? r : balanceDeletion(r, replacement);
3015	>
3016	>	if (p == replacement) {  // detach pointers
3017	>	TreeNode<K,V> pp;
3018	>	if ((pp = p.parent) != null) {
3019	>	if (p == pp.left)
3020	>	pp.left = null;
3021	>	else if (p == pp.right)
3022	>	pp.right = null;
3023	>	p.parent = null;
3024	>	}
3025	>	}
3026	>	} finally {
3027	>	unlockRoot();
3028	>	}
3029	>	assert checkInvariants(root);
3030	>	return false;
3031	>	}
3032	>
3033	>	/* ------------------------------------------------------------ */
3034	>	// Red-black tree methods, all adapted from CLR
3035	>
3036	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3037	>	TreeNode<K,V> p) {
3038	>	TreeNode<K,V> r, pp, rl;
3039	>	if (p != null && (r = p.right) != null) {
3040	>	if ((rl = p.right = r.left) != null)
3041	>	rl.parent = p;
3042	>	if ((pp = r.parent = p.parent) == null)
3043	>	(root = r).red = false;
3044	>	else if (pp.left == p)
3045	>	pp.left = r;
3046	>	else
3047	>	pp.right = r;
3048	>	r.left = p;
3049	>	p.parent = r;
3050	>	}
3051	>	return root;
3052	>	}
3053	>
3054	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3055	>	TreeNode<K,V> p) {
3056	>	TreeNode<K,V> l, pp, lr;
3057	>	if (p != null && (l = p.left) != null) {
3058	>	if ((lr = p.left = l.right) != null)
3059	>	lr.parent = p;
3060	>	if ((pp = l.parent = p.parent) == null)
3061	>	(root = l).red = false;
3062	>	else if (pp.right == p)
3063	>	pp.right = l;
3064	>	else
3065	>	pp.left = l;
3066	>	l.right = p;
3067	>	p.parent = l;
3068	>	}
3069	>	return root;
3070	>	}
3071	>
3072	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3073	>	TreeNode<K,V> x) {
3074	>	x.red = true;
3075	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3076	>	if ((xp = x.parent) == null) {
3077	>	x.red = false;
3078	>	return x;
3079	>	}
3080	>	else if (!xp.red || (xpp = xp.parent) == null)
3081	>	return root;
3082	>	if (xp == (xppl = xpp.left)) {
3083	>	if ((xppr = xpp.right) != null && xppr.red) {
3084	>	xppr.red = false;
3085	>	xp.red = false;
3086	>	xpp.red = true;
3087	>	x = xpp;
3088	>	}
3089	>	else {
3090	>	if (x == xp.right) {
3091	>	root = rotateLeft(root, x = xp);
3092	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3093	>	}
3094	>	if (xp != null) {
3095	>	xp.red = false;
3096	>	if (xpp != null) {
3097	>	xpp.red = true;
3098	>	root = rotateRight(root, xpp);
3099	>	}
3100	>	}
3101	>	}
3102	>	}
3103	>	else {
3104	>	if (xppl != null && xppl.red) {
3105	>	xppl.red = false;
3106	>	xp.red = false;
3107	>	xpp.red = true;
3108	>	x = xpp;
3109	>	}
3110	>	else {
3111	>	if (x == xp.left) {
3112	>	root = rotateRight(root, x = xp);
3113	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3114	>	}
3115	>	if (xp != null) {
3116	>	xp.red = false;
3117	>	if (xpp != null) {
3118	>	xpp.red = true;
3119	>	root = rotateLeft(root, xpp);
3120	>	}
3121	>	}
3122	>	}
3123	>	}
3124	>	}
3125	>	}
3126	>
3127	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3128	>	TreeNode<K,V> x) {
3129	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3130	>	if (x == null || x == root)
3131	>	return root;
3132	>	else if ((xp = x.parent) == null) {
3133	>	x.red = false;
3134	>	return x;
3135	>	}
3136	>	else if (x.red) {
3137	>	x.red = false;
3138	>	return root;
3139	>	}
3140	>	else if ((xpl = xp.left) == x) {
3141	>	if ((xpr = xp.right) != null && xpr.red) {
3142	>	xpr.red = false;
3143	>	xp.red = true;
3144	>	root = rotateLeft(root, xp);
3145	>	xpr = (xp = x.parent) == null ? null : xp.right;
3146	>	}
3147	>	if (xpr == null)
3148	>	x = xp;
3149	>	else {
3150	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3151	>	if ((sr == null || !sr.red) &&
3152	>	(sl == null || !sl.red)) {
3153	>	xpr.red = true;
3154	>	x = xp;
3155	>	}
3156	>	else {
3157	>	if (sr == null || !sr.red) {
3158	>	if (sl != null)
3159	>	sl.red = false;
3160	>	xpr.red = true;
3161	>	root = rotateRight(root, xpr);
3162	>	xpr = (xp = x.parent) == null ?
3163	>	null : xp.right;
3164	>	}
3165	>	if (xpr != null) {
3166	>	xpr.red = (xp == null) ? false : xp.red;
3167	>	if ((sr = xpr.right) != null)
3168	>	sr.red = false;
3169	>	}
3170	>	if (xp != null) {
3171	>	xp.red = false;
3172	>	root = rotateLeft(root, xp);
3173	>	}
3174	>	x = root;
3175	>	}
3176	>	}
3177	>	}
3178	>	else { // symmetric
3179	>	if (xpl != null && xpl.red) {
3180	>	xpl.red = false;
3181	>	xp.red = true;
3182	>	root = rotateRight(root, xp);
3183	>	xpl = (xp = x.parent) == null ? null : xp.left;
3184	>	}
3185	>	if (xpl == null)
3186	>	x = xp;
3187	>	else {
3188	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3189	>	if ((sl == null || !sl.red) &&
3190	>	(sr == null || !sr.red)) {
3191	>	xpl.red = true;
3192	>	x = xp;
3193	>	}
3194	>	else {
3195	>	if (sl == null || !sl.red) {
3196	>	if (sr != null)
3197	>	sr.red = false;
3198	>	xpl.red = true;
3199	>	root = rotateLeft(root, xpl);
3200	>	xpl = (xp = x.parent) == null ?
3201	>	null : xp.left;
3202	>	}
3203	>	if (xpl != null) {
3204	>	xpl.red = (xp == null) ? false : xp.red;
3205	>	if ((sl = xpl.left) != null)
3206	>	sl.red = false;
3207	>	}
3208	>	if (xp != null) {
3209	>	xp.red = false;
3210	>	root = rotateRight(root, xp);
3211	>	}
3212	>	x = root;
3213	>	}
3214	>	}
3215	>	}
3216	>	}
3217	>	}
3218	>
3219	>	/**
3220	>	* Recursive invariant check
3221	>	*/
3222	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3223	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3224	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3225	>	if (tb != null && tb.next != t)
3226	>	return false;
3227	>	if (tn != null && tn.prev != t)
3228	>	return false;
3229	>	if (tp != null && t != tp.left && t != tp.right)
3230	>	return false;
3231	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3232	>	return false;
3233	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3234	>	return false;
3235	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3236	>	return false;
3237	>	if (tl != null && !checkInvariants(tl))
3238	>	return false;
3239	>	if (tr != null && !checkInvariants(tr))
3240	>	return false;
3241	>	return true;
3242	>	}
3243	>
3244	>	private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
3245	>	private static final long LOCKSTATE;
3246	>	static {
3247	>	try {
3248	>	LOCKSTATE = U.objectFieldOffset
3249	>	(TreeBin.class.getDeclaredField("lockState"));
3250	>	} catch (ReflectiveOperationException e) {
3251	>	throw new Error(e);
3252	>	}
3253	>	}
3254	>	}
3255	>
3256	>	/* ----------------Table Traversal -------------- */
3257	>
3258	>	/**
3259	>	* Records the table, its length, and current traversal index for a
3260	>	* traverser that must process a region of a forwarded table before
3261	>	* proceeding with current table.
3262	>	*/
3263	>	static final class TableStack<K,V> {
3264	>	int length;
3265	>	int index;
3266	>	Node<K,V>[] tab;
3267	>	TableStack<K,V> next;
3268	>	}
3269	>
3270	>	/**
3271	>	* Encapsulates traversal for methods such as containsValue; also
3272	>	* serves as a base class for other iterators and spliterators.
3273	>	*
3274	>	* Method advance visits once each still-valid node that was
3275	>	* reachable upon iterator construction. It might miss some that
3276	>	* were added to a bin after the bin was visited, which is OK wrt
3277	>	* consistency guarantees. Maintaining this property in the face
3278	>	* of possible ongoing resizes requires a fair amount of
3279	>	* bookkeeping state that is difficult to optimize away amidst
3280	>	* volatile accesses.  Even so, traversal maintains reasonable
3281	>	* throughput.
3282	>	*
3283	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3284	>	* However, if the table has been resized, then all future steps
3285	>	* must traverse both the bin at the current index as well as at
3286	>	* (index + baseSize); and so on for further resizings. To
3287	>	* paranoically cope with potential sharing by users of iterators
3288	>	* across threads, iteration terminates if a bounds checks fails
3289	>	* for a table read.
3290	>	*/
3291	>	static class Traverser<K,V> {
3292	>	Node<K,V>[] tab;        // current table; updated if resized
3293	>	Node<K,V> next;         // the next entry to use
3294	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3295	>	int index;              // index of bin to use next
3296	>	int baseIndex;          // current index of initial table
3297	>	int baseLimit;          // index bound for initial table
3298	>	final int baseSize;     // initial table size
3299	>
3300	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3301	>	this.tab = tab;
3302	>	this.baseSize = size;
3303	>	this.baseIndex = this.index = index;
3304	>	this.baseLimit = limit;
3305	>	this.next = null;
3306	>	}
3307	>
3308	>	/**
3309	>	* Advances if possible, returning next valid node, or null if none.
3310	>	*/
3311	>	final Node<K,V> advance() {
3312	>	Node<K,V> e;
3313	>	if ((e = next) != null)
3314	>	e = e.next;
3315	>	for (;;) {
3316	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3317	>	if (e != null)
3318	>	return next = e;
3319	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3320	>	(n = t.length) <= (i = index) || i < 0)
3321	>	return next = null;
3322	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3323	>	if (e instanceof ForwardingNode) {
3324	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3325	>	e = null;
3326	>	pushState(t, i, n);
3327	>	continue;
3328	>	}
3329	>	else if (e instanceof TreeBin)
3330	>	e = ((TreeBin<K,V>)e).first;
3331	>	else
3332	>	e = null;
3333	>	}
3334	>	if (stack != null)
3335	>	recoverState(n);
3336	>	else if ((index = i + baseSize) >= n)
3337	>	index = ++baseIndex; // visit upper slots if present
3338	>	}
3339		}
3340
3341	<	public final boolean hasNext() { return nextEntry != null; }
3342	<	public final boolean hasMoreElements() { return nextEntry != null; }
3341	>	/**
3342	>	* Saves traversal state upon encountering a forwarding node.
3343	>	*/
3344	>	private void pushState(Node<K,V>[] t, int i, int n) {
3345	>	TableStack<K,V> s = spare;  // reuse if possible
3346	>	if (s != null)
3347	>	spare = s.next;
3348	>	else
3349	>	s = new TableStack<K,V>();
3350	>	s.tab = t;
3351	>	s.length = n;
3352	>	s.index = i;
3353	>	s.next = stack;
3354	>	stack = s;
3355	>	}
3356	>
3357	>	/**
3358	>	* Possibly pops traversal state.
3359	>	*
3360	>	* @param n length of current table
3361	>	*/
3362	>	private void recoverState(int n) {
3363	>	TableStack<K,V> s; int len;
3364	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3365	>	n = len;
3366	>	index = s.index;
3367	>	tab = s.tab;
3368	>	s.tab = null;
3369	>	TableStack<K,V> next = s.next;
3370	>	s.next = spare; // save for reuse
3371	>	stack = next;
3372	>	spare = s;
3373	>	}
3374	>	if (s == null && (index += baseSize) >= n)
3375	>	index = ++baseIndex;
3376	>	}
3377	>	}
3378	>
3379	>	/**
3380	>	* Base of key, value, and entry Iterators. Adds fields to
3381	>	* Traverser to support iterator.remove.
3382	>	*/
3383	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3384	>	final ConcurrentHashMap<K,V> map;
3385	>	Node<K,V> lastReturned;
3386	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3387	>	ConcurrentHashMap<K,V> map) {
3388	>	super(tab, size, index, limit);
3389	>	this.map = map;
3390	>	advance();
3391	>	}
3392	>
3393	>	public final boolean hasNext() { return next != null; }
3394	>	public final boolean hasMoreElements() { return next != null; }
3395
3396		public final void remove() {
3397	<	if (lastReturned == null)
3397	>	Node<K,V> p;
3398	>	if ((p = lastReturned) == null)
3399		throw new IllegalStateException();
1271	–	ConcurrentHashMap.this.remove(lastReturned.key);
3400		lastReturned = null;
3401	+	map.replaceNode(p.key, null, null);
3402	+	}
3403	+	}
3404	+
3405	+	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3406	+	implements Iterator<K>, Enumeration<K> {
3407	+	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3408	+	ConcurrentHashMap<K,V> map) {
3409	+	super(tab, index, size, limit, map);
3410	+	}
3411	+
3412	+	public final K next() {
3413	+	Node<K,V> p;
3414	+	if ((p = next) == null)
3415	+	throw new NoSuchElementException();
3416	+	K k = p.key;
3417	+	lastReturned = p;
3418	+	advance();
3419	+	return k;
3420	+	}
3421	+
3422	+	public final K nextElement() { return next(); }
3423	+	}
3424	+
3425	+	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3426	+	implements Iterator<V>, Enumeration<V> {
3427	+	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3428	+	ConcurrentHashMap<K,V> map) {
3429	+	super(tab, index, size, limit, map);
3430	+	}
3431	+
3432	+	public final V next() {
3433	+	Node<K,V> p;
3434	+	if ((p = next) == null)
3435	+	throw new NoSuchElementException();
3436	+	V v = p.val;
3437	+	lastReturned = p;
3438	+	advance();
3439	+	return v;
3440		}
3441	+
3442	+	public final V nextElement() { return next(); }
3443		}
3444
3445	<	final class KeyIterator
3446	<	extends HashIterator
3447	<	implements Iterator<K>, Enumeration<K>
3448	<	{
3449	<	public final K next()        { return super.nextEntry().key; }
3450	<	public final K nextElement() { return super.nextEntry().key; }
3451	<	}
3452	<
3453	<	final class ValueIterator
3454	<	extends HashIterator
3455	<	implements Iterator<V>, Enumeration<V>
3456	<	{
3457	<	public final V next()        { return super.nextEntry().value; }
3458	<	public final V nextElement() { return super.nextEntry().value; }
3445	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3446	>	implements Iterator<Map.Entry<K,V>> {
3447	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3448	>	ConcurrentHashMap<K,V> map) {
3449	>	super(tab, index, size, limit, map);
3450	>	}
3451	>
3452	>	public final Map.Entry<K,V> next() {
3453	>	Node<K,V> p;
3454	>	if ((p = next) == null)
3455	>	throw new NoSuchElementException();
3456	>	K k = p.key;
3457	>	V v = p.val;
3458	>	lastReturned = p;
3459	>	advance();
3460	>	return new MapEntry<K,V>(k, v, map);
3461	>	}
3462		}
3463
3464		/**
3465	<	* Custom Entry class used by EntryIterator.next(), that relays
3466	<	* setValue changes to the underlying map.
3467	<	*/
3468	<	final class WriteThroughEntry
3469	<	extends AbstractMap.SimpleEntry<K,V>
3470	<	{
3471	<	WriteThroughEntry(K k, V v) {
3472	<	super(k,v);
3465	>	* Exported Entry for EntryIterator
3466	>	*/
3467	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3468	>	final K key; // non-null
3469	>	V val;       // non-null
3470	>	final ConcurrentHashMap<K,V> map;
3471	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3472	>	this.key = key;
3473	>	this.val = val;
3474	>	this.map = map;
3475	>	}
3476	>	public K getKey()        { return key; }
3477	>	public V getValue()      { return val; }
3478	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3479	>	public String toString() {
3480	>	return Helpers.mapEntryToString(key, val);
3481	>	}
3482	>
3483	>	public boolean equals(Object o) {
3484	>	Object k, v; Map.Entry<?,?> e;
3485	>	return ((o instanceof Map.Entry) &&
3486	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3487	>	(v = e.getValue()) != null &&
3488	>	(k == key || k.equals(key)) &&
3489	>	(v == val || v.equals(val)));
3490		}
3491
3492		/**
3493		* Sets our entry's value and writes through to the map. The
3494	<	* value to return is somewhat arbitrary here. Since a
3495	<	* WriteThroughEntry does not necessarily track asynchronous
3496	<	* changes, the most recent "previous" value could be
3497	<	* different from what we return (or could even have been
3498	<	* removed in which case the put will re-establish). We do not
1310	<	* and cannot guarantee more.
3494	>	* value to return is somewhat arbitrary here. Since we do not
3495	>	* necessarily track asynchronous changes, the most recent
3496	>	* "previous" value could be different from what we return (or
3497	>	* could even have been removed, in which case the put will
3498	>	* re-establish). We do not and cannot guarantee more.
3499		*/
3500		public V setValue(V value) {
3501		if (value == null) throw new NullPointerException();
3502	<	V v = super.setValue(value);
3503	<	ConcurrentHashMap.this.put(getKey(), value);
3502	>	V v = val;
3503	>	val = value;
3504	>	map.put(key, value);
3505		return v;
3506		}
3507		}
3508
3509	<	final class EntryIterator
3510	<	extends HashIterator
3511	<	implements Iterator<Entry<K,V>>
3512	<	{
3513	<	public Map.Entry<K,V> next() {
3514	<	HashEntry<K,V> e = super.nextEntry();
3515	<	return new WriteThroughEntry(e.key, e.value);
3509	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3510	>	implements Spliterator<K> {
3511	>	long est;               // size estimate
3512	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3513	>	long est) {
3514	>	super(tab, size, index, limit);
3515	>	this.est = est;
3516	>	}
3517	>
3518	>	public Spliterator<K> trySplit() {
3519	>	int i, f, h;
3520	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3521	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3522	>	f, est >>>= 1);
3523	>	}
3524	>
3525	>	public void forEachRemaining(Consumer<? super K> action) {
3526	>	if (action == null) throw new NullPointerException();
3527	>	for (Node<K,V> p; (p = advance()) != null;)
3528	>	action.accept(p.key);
3529	>	}
3530	>
3531	>	public boolean tryAdvance(Consumer<? super K> action) {
3532	>	if (action == null) throw new NullPointerException();
3533	>	Node<K,V> p;
3534	>	if ((p = advance()) == null)
3535	>	return false;
3536	>	action.accept(p.key);
3537	>	return true;
3538	>	}
3539	>
3540	>	public long estimateSize() { return est; }
3541	>
3542	>	public int characteristics() {
3543	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3544	>	Spliterator.NONNULL;
3545		}
3546		}
3547
3548	<	final class KeySet extends AbstractSet<K> {
3549	<	public Iterator<K> iterator() {
3550	<	return new KeyIterator();
3548	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3549	>	implements Spliterator<V> {
3550	>	long est;               // size estimate
3551	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3552	>	long est) {
3553	>	super(tab, size, index, limit);
3554	>	this.est = est;
3555		}
3556	<	public int size() {
3557	<	return ConcurrentHashMap.this.size();
3556	>
3557	>	public Spliterator<V> trySplit() {
3558	>	int i, f, h;
3559	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3560	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3561	>	f, est >>>= 1);
3562		}
3563	<	public boolean isEmpty() {
3564	<	return ConcurrentHashMap.this.isEmpty();
3563	>
3564	>	public void forEachRemaining(Consumer<? super V> action) {
3565	>	if (action == null) throw new NullPointerException();
3566	>	for (Node<K,V> p; (p = advance()) != null;)
3567	>	action.accept(p.val);
3568		}
3569	<	public boolean contains(Object o) {
3570	<	return ConcurrentHashMap.this.containsKey(o);
3569	>
3570	>	public boolean tryAdvance(Consumer<? super V> action) {
3571	>	if (action == null) throw new NullPointerException();
3572	>	Node<K,V> p;
3573	>	if ((p = advance()) == null)
3574	>	return false;
3575	>	action.accept(p.val);
3576	>	return true;
3577		}
3578	<	public boolean remove(Object o) {
3579	<	return ConcurrentHashMap.this.remove(o) != null;
3578	>
3579	>	public long estimateSize() { return est; }
3580	>
3581	>	public int characteristics() {
3582	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3583	>	}
3584	>	}
3585	>
3586	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3587	>	implements Spliterator<Map.Entry<K,V>> {
3588	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3589	>	long est;               // size estimate
3590	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3591	>	long est, ConcurrentHashMap<K,V> map) {
3592	>	super(tab, size, index, limit);
3593	>	this.map = map;
3594	>	this.est = est;
3595	>	}
3596	>
3597	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3598	>	int i, f, h;
3599	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3600	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3601	>	f, est >>>= 1, map);
3602	>	}
3603	>
3604	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3605	>	if (action == null) throw new NullPointerException();
3606	>	for (Node<K,V> p; (p = advance()) != null; )
3607	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3608		}
3609	<	public void clear() {
3610	<	ConcurrentHashMap.this.clear();
3609	>
3610	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3611	>	if (action == null) throw new NullPointerException();
3612	>	Node<K,V> p;
3613	>	if ((p = advance()) == null)
3614	>	return false;
3615	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3616	>	return true;
3617		}
3618	+
3619	+	public long estimateSize() { return est; }
3620	+
3621	+	public int characteristics() {
3622	+	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3623	+	Spliterator.NONNULL;
3624	+	}
3625	+	}
3626	+
3627	+	// Parallel bulk operations
3628	+
3629	+	/**
3630	+	* Computes initial batch value for bulk tasks. The returned value
3631	+	* is approximately exp2 of the number of times (minus one) to
3632	+	* split task by two before executing leaf action. This value is
3633	+	* faster to compute and more convenient to use as a guide to
3634	+	* splitting than is the depth, since it is used while dividing by
3635	+	* two anyway.
3636	+	*/
3637	+	final int batchFor(long b) {
3638	+	long n;
3639	+	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3640	+	return 0;
3641	+	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3642	+	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3643	+	}
3644	+
3645	+	/**
3646	+	* Performs the given action for each (key, value).
3647	+	*
3648	+	* @param parallelismThreshold the (estimated) number of elements
3649	+	* needed for this operation to be executed in parallel
3650	+	* @param action the action
3651	+	* @since 1.8
3652	+	*/
3653	+	public void forEach(long parallelismThreshold,
3654	+	BiConsumer<? super K,? super V> action) {
3655	+	if (action == null) throw new NullPointerException();
3656	+	new ForEachMappingTask<K,V>
3657	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3658	+	action).invoke();
3659	+	}
3660	+
3661	+	/**
3662	+	* Performs the given action for each non-null transformation
3663	+	* of each (key, value).
3664	+	*
3665	+	* @param parallelismThreshold the (estimated) number of elements
3666	+	* needed for this operation to be executed in parallel
3667	+	* @param transformer a function returning the transformation
3668	+	* for an element, or null if there is no transformation (in
3669	+	* which case the action is not applied)
3670	+	* @param action the action
3671	+	* @param <U> the return type of the transformer
3672	+	* @since 1.8
3673	+	*/
3674	+	public <U> void forEach(long parallelismThreshold,
3675	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3676	+	Consumer<? super U> action) {
3677	+	if (transformer == null || action == null)
3678	+	throw new NullPointerException();
3679	+	new ForEachTransformedMappingTask<K,V,U>
3680	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3681	+	transformer, action).invoke();
3682	+	}
3683	+
3684	+	/**
3685	+	* Returns a non-null result from applying the given search
3686	+	* function on each (key, value), or null if none.  Upon
3687	+	* success, further element processing is suppressed and the
3688	+	* results of any other parallel invocations of the search
3689	+	* function are ignored.
3690	+	*
3691	+	* @param parallelismThreshold the (estimated) number of elements
3692	+	* needed for this operation to be executed in parallel
3693	+	* @param searchFunction a function returning a non-null
3694	+	* result on success, else null
3695	+	* @param <U> the return type of the search function
3696	+	* @return a non-null result from applying the given search
3697	+	* function on each (key, value), or null if none
3698	+	* @since 1.8
3699	+	*/
3700	+	public <U> U search(long parallelismThreshold,
3701	+	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3702	+	if (searchFunction == null) throw new NullPointerException();
3703	+	return new SearchMappingsTask<K,V,U>
3704	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3705	+	searchFunction, new AtomicReference<U>()).invoke();
3706	+	}
3707	+
3708	+	/**
3709	+	* Returns the result of accumulating the given transformation
3710	+	* of all (key, value) pairs using the given reducer to
3711	+	* combine values, or null if none.
3712	+	*
3713	+	* @param parallelismThreshold the (estimated) number of elements
3714	+	* needed for this operation to be executed in parallel
3715	+	* @param transformer a function returning the transformation
3716	+	* for an element, or null if there is no transformation (in
3717	+	* which case it is not combined)
3718	+	* @param reducer a commutative associative combining function
3719	+	* @param <U> the return type of the transformer
3720	+	* @return the result of accumulating the given transformation
3721	+	* of all (key, value) pairs
3722	+	* @since 1.8
3723	+	*/
3724	+	public <U> U reduce(long parallelismThreshold,
3725	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3726	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3727	+	if (transformer == null || reducer == null)
3728	+	throw new NullPointerException();
3729	+	return new MapReduceMappingsTask<K,V,U>
3730	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3731	+	null, transformer, reducer).invoke();
3732	+	}
3733	+
3734	+	/**
3735	+	* Returns the result of accumulating the given transformation
3736	+	* of all (key, value) pairs using the given reducer to
3737	+	* combine values, and the given basis as an identity value.
3738	+	*
3739	+	* @param parallelismThreshold the (estimated) number of elements
3740	+	* needed for this operation to be executed in parallel
3741	+	* @param transformer a function returning the transformation
3742	+	* for an element
3743	+	* @param basis the identity (initial default value) for the reduction
3744	+	* @param reducer a commutative associative combining function
3745	+	* @return the result of accumulating the given transformation
3746	+	* of all (key, value) pairs
3747	+	* @since 1.8
3748	+	*/
3749	+	public double reduceToDouble(long parallelismThreshold,
3750	+	ToDoubleBiFunction<? super K, ? super V> transformer,
3751	+	double basis,
3752	+	DoubleBinaryOperator reducer) {
3753	+	if (transformer == null || reducer == null)
3754	+	throw new NullPointerException();
3755	+	return new MapReduceMappingsToDoubleTask<K,V>
3756	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3757	+	null, transformer, basis, reducer).invoke();
3758	+	}
3759	+
3760	+	/**
3761	+	* Returns the result of accumulating the given transformation
3762	+	* of all (key, value) pairs using the given reducer to
3763	+	* combine values, and the given basis as an identity value.
3764	+	*
3765	+	* @param parallelismThreshold the (estimated) number of elements
3766	+	* needed for this operation to be executed in parallel
3767	+	* @param transformer a function returning the transformation
3768	+	* for an element
3769	+	* @param basis the identity (initial default value) for the reduction
3770	+	* @param reducer a commutative associative combining function
3771	+	* @return the result of accumulating the given transformation
3772	+	* of all (key, value) pairs
3773	+	* @since 1.8
3774	+	*/
3775	+	public long reduceToLong(long parallelismThreshold,
3776	+	ToLongBiFunction<? super K, ? super V> transformer,
3777	+	long basis,
3778	+	LongBinaryOperator reducer) {
3779	+	if (transformer == null || reducer == null)
3780	+	throw new NullPointerException();
3781	+	return new MapReduceMappingsToLongTask<K,V>
3782	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3783	+	null, transformer, basis, reducer).invoke();
3784	+	}
3785	+
3786	+	/**
3787	+	* Returns the result of accumulating the given transformation
3788	+	* of all (key, value) pairs using the given reducer to
3789	+	* combine values, and the given basis as an identity value.
3790	+	*
3791	+	* @param parallelismThreshold the (estimated) number of elements
3792	+	* needed for this operation to be executed in parallel
3793	+	* @param transformer a function returning the transformation
3794	+	* for an element
3795	+	* @param basis the identity (initial default value) for the reduction
3796	+	* @param reducer a commutative associative combining function
3797	+	* @return the result of accumulating the given transformation
3798	+	* of all (key, value) pairs
3799	+	* @since 1.8
3800	+	*/
3801	+	public int reduceToInt(long parallelismThreshold,
3802	+	ToIntBiFunction<? super K, ? super V> transformer,
3803	+	int basis,
3804	+	IntBinaryOperator reducer) {
3805	+	if (transformer == null || reducer == null)
3806	+	throw new NullPointerException();
3807	+	return new MapReduceMappingsToIntTask<K,V>
3808	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3809	+	null, transformer, basis, reducer).invoke();
3810	+	}
3811	+
3812	+	/**
3813	+	* Performs the given action for each key.
3814	+	*
3815	+	* @param parallelismThreshold the (estimated) number of elements
3816	+	* needed for this operation to be executed in parallel
3817	+	* @param action the action
3818	+	* @since 1.8
3819	+	*/
3820	+	public void forEachKey(long parallelismThreshold,
3821	+	Consumer<? super K> action) {
3822	+	if (action == null) throw new NullPointerException();
3823	+	new ForEachKeyTask<K,V>
3824	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3825	+	action).invoke();
3826	+	}
3827	+
3828	+	/**
3829	+	* Performs the given action for each non-null transformation
3830	+	* of each key.
3831	+	*
3832	+	* @param parallelismThreshold the (estimated) number of elements
3833	+	* needed for this operation to be executed in parallel
3834	+	* @param transformer a function returning the transformation
3835	+	* for an element, or null if there is no transformation (in
3836	+	* which case the action is not applied)
3837	+	* @param action the action
3838	+	* @param <U> the return type of the transformer
3839	+	* @since 1.8
3840	+	*/
3841	+	public <U> void forEachKey(long parallelismThreshold,
3842	+	Function<? super K, ? extends U> transformer,
3843	+	Consumer<? super U> action) {
3844	+	if (transformer == null || action == null)
3845	+	throw new NullPointerException();
3846	+	new ForEachTransformedKeyTask<K,V,U>
3847	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3848	+	transformer, action).invoke();
3849	+	}
3850	+
3851	+	/**
3852	+	* Returns a non-null result from applying the given search
3853	+	* function on each key, or null if none. Upon success,
3854	+	* further element processing is suppressed and the results of
3855	+	* any other parallel invocations of the search function are
3856	+	* ignored.
3857	+	*
3858	+	* @param parallelismThreshold the (estimated) number of elements
3859	+	* needed for this operation to be executed in parallel
3860	+	* @param searchFunction a function returning a non-null
3861	+	* result on success, else null
3862	+	* @param <U> the return type of the search function
3863	+	* @return a non-null result from applying the given search
3864	+	* function on each key, or null if none
3865	+	* @since 1.8
3866	+	*/
3867	+	public <U> U searchKeys(long parallelismThreshold,
3868	+	Function<? super K, ? extends U> searchFunction) {
3869	+	if (searchFunction == null) throw new NullPointerException();
3870	+	return new SearchKeysTask<K,V,U>
3871	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3872	+	searchFunction, new AtomicReference<U>()).invoke();
3873	+	}
3874	+
3875	+	/**
3876	+	* Returns the result of accumulating all keys using the given
3877	+	* reducer to combine values, or null if none.
3878	+	*
3879	+	* @param parallelismThreshold the (estimated) number of elements
3880	+	* needed for this operation to be executed in parallel
3881	+	* @param reducer a commutative associative combining function
3882	+	* @return the result of accumulating all keys using the given
3883	+	* reducer to combine values, or null if none
3884	+	* @since 1.8
3885	+	*/
3886	+	public K reduceKeys(long parallelismThreshold,
3887	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
3888	+	if (reducer == null) throw new NullPointerException();
3889	+	return new ReduceKeysTask<K,V>
3890	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3891	+	null, reducer).invoke();
3892	+	}
3893	+
3894	+	/**
3895	+	* Returns the result of accumulating the given transformation
3896	+	* of all keys using the given reducer to combine values, or
3897	+	* null if none.
3898	+	*
3899	+	* @param parallelismThreshold the (estimated) number of elements
3900	+	* needed for this operation to be executed in parallel
3901	+	* @param transformer a function returning the transformation
3902	+	* for an element, or null if there is no transformation (in
3903	+	* which case it is not combined)
3904	+	* @param reducer a commutative associative combining function
3905	+	* @param <U> the return type of the transformer
3906	+	* @return the result of accumulating the given transformation
3907	+	* of all keys
3908	+	* @since 1.8
3909	+	*/
3910	+	public <U> U reduceKeys(long parallelismThreshold,
3911	+	Function<? super K, ? extends U> transformer,
3912	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3913	+	if (transformer == null || reducer == null)
3914	+	throw new NullPointerException();
3915	+	return new MapReduceKeysTask<K,V,U>
3916	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3917	+	null, transformer, reducer).invoke();
3918	+	}
3919	+
3920	+	/**
3921	+	* Returns the result of accumulating the given transformation
3922	+	* of all keys using the given reducer to combine values, and
3923	+	* the given basis as an identity value.
3924	+	*
3925	+	* @param parallelismThreshold the (estimated) number of elements
3926	+	* needed for this operation to be executed in parallel
3927	+	* @param transformer a function returning the transformation
3928	+	* for an element
3929	+	* @param basis the identity (initial default value) for the reduction
3930	+	* @param reducer a commutative associative combining function
3931	+	* @return the result of accumulating the given transformation
3932	+	* of all keys
3933	+	* @since 1.8
3934	+	*/
3935	+	public double reduceKeysToDouble(long parallelismThreshold,
3936	+	ToDoubleFunction<? super K> transformer,
3937	+	double basis,
3938	+	DoubleBinaryOperator reducer) {
3939	+	if (transformer == null || reducer == null)
3940	+	throw new NullPointerException();
3941	+	return new MapReduceKeysToDoubleTask<K,V>
3942	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3943	+	null, transformer, basis, reducer).invoke();
3944	+	}
3945	+
3946	+	/**
3947	+	* Returns the result of accumulating the given transformation
3948	+	* of all keys using the given reducer to combine values, and
3949	+	* the given basis as an identity value.
3950	+	*
3951	+	* @param parallelismThreshold the (estimated) number of elements
3952	+	* needed for this operation to be executed in parallel
3953	+	* @param transformer a function returning the transformation
3954	+	* for an element
3955	+	* @param basis the identity (initial default value) for the reduction
3956	+	* @param reducer a commutative associative combining function
3957	+	* @return the result of accumulating the given transformation
3958	+	* of all keys
3959	+	* @since 1.8
3960	+	*/
3961	+	public long reduceKeysToLong(long parallelismThreshold,
3962	+	ToLongFunction<? super K> transformer,
3963	+	long basis,
3964	+	LongBinaryOperator reducer) {
3965	+	if (transformer == null || reducer == null)
3966	+	throw new NullPointerException();
3967	+	return new MapReduceKeysToLongTask<K,V>
3968	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3969	+	null, transformer, basis, reducer).invoke();
3970	+	}
3971	+
3972	+	/**
3973	+	* Returns the result of accumulating the given transformation
3974	+	* of all keys using the given reducer to combine values, and
3975	+	* the given basis as an identity value.
3976	+	*
3977	+	* @param parallelismThreshold the (estimated) number of elements
3978	+	* needed for this operation to be executed in parallel
3979	+	* @param transformer a function returning the transformation
3980	+	* for an element
3981	+	* @param basis the identity (initial default value) for the reduction
3982	+	* @param reducer a commutative associative combining function
3983	+	* @return the result of accumulating the given transformation
3984	+	* of all keys
3985	+	* @since 1.8
3986	+	*/
3987	+	public int reduceKeysToInt(long parallelismThreshold,
3988	+	ToIntFunction<? super K> transformer,
3989	+	int basis,
3990	+	IntBinaryOperator reducer) {
3991	+	if (transformer == null || reducer == null)
3992	+	throw new NullPointerException();
3993	+	return new MapReduceKeysToIntTask<K,V>
3994	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3995	+	null, transformer, basis, reducer).invoke();
3996	+	}
3997	+
3998	+	/**
3999	+	* Performs the given action for each value.
4000	+	*
4001	+	* @param parallelismThreshold the (estimated) number of elements
4002	+	* needed for this operation to be executed in parallel
4003	+	* @param action the action
4004	+	* @since 1.8
4005	+	*/
4006	+	public void forEachValue(long parallelismThreshold,
4007	+	Consumer<? super V> action) {
4008	+	if (action == null)
4009	+	throw new NullPointerException();
4010	+	new ForEachValueTask<K,V>
4011	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4012	+	action).invoke();
4013	+	}
4014	+
4015	+	/**
4016	+	* Performs the given action for each non-null transformation
4017	+	* of each value.
4018	+	*
4019	+	* @param parallelismThreshold the (estimated) number of elements
4020	+	* needed for this operation to be executed in parallel
4021	+	* @param transformer a function returning the transformation
4022	+	* for an element, or null if there is no transformation (in
4023	+	* which case the action is not applied)
4024	+	* @param action the action
4025	+	* @param <U> the return type of the transformer
4026	+	* @since 1.8
4027	+	*/
4028	+	public <U> void forEachValue(long parallelismThreshold,
4029	+	Function<? super V, ? extends U> transformer,
4030	+	Consumer<? super U> action) {
4031	+	if (transformer == null || action == null)
4032	+	throw new NullPointerException();
4033	+	new ForEachTransformedValueTask<K,V,U>
4034	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4035	+	transformer, action).invoke();
4036	+	}
4037	+
4038	+	/**
4039	+	* Returns a non-null result from applying the given search
4040	+	* function on each value, or null if none.  Upon success,
4041	+	* further element processing is suppressed and the results of
4042	+	* any other parallel invocations of the search function are
4043	+	* ignored.
4044	+	*
4045	+	* @param parallelismThreshold the (estimated) number of elements
4046	+	* needed for this operation to be executed in parallel
4047	+	* @param searchFunction a function returning a non-null
4048	+	* result on success, else null
4049	+	* @param <U> the return type of the search function
4050	+	* @return a non-null result from applying the given search
4051	+	* function on each value, or null if none
4052	+	* @since 1.8
4053	+	*/
4054	+	public <U> U searchValues(long parallelismThreshold,
4055	+	Function<? super V, ? extends U> searchFunction) {
4056	+	if (searchFunction == null) throw new NullPointerException();
4057	+	return new SearchValuesTask<K,V,U>
4058	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4059	+	searchFunction, new AtomicReference<U>()).invoke();
4060	+	}
4061	+
4062	+	/**
4063	+	* Returns the result of accumulating all values using the
4064	+	* given reducer to combine values, or null if none.
4065	+	*
4066	+	* @param parallelismThreshold the (estimated) number of elements
4067	+	* needed for this operation to be executed in parallel
4068	+	* @param reducer a commutative associative combining function
4069	+	* @return the result of accumulating all values
4070	+	* @since 1.8
4071	+	*/
4072	+	public V reduceValues(long parallelismThreshold,
4073	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
4074	+	if (reducer == null) throw new NullPointerException();
4075	+	return new ReduceValuesTask<K,V>
4076	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4077	+	null, reducer).invoke();
4078	+	}
4079	+
4080	+	/**
4081	+	* Returns the result of accumulating the given transformation
4082	+	* of all values using the given reducer to combine values, or
4083	+	* null if none.
4084	+	*
4085	+	* @param parallelismThreshold the (estimated) number of elements
4086	+	* needed for this operation to be executed in parallel
4087	+	* @param transformer a function returning the transformation
4088	+	* for an element, or null if there is no transformation (in
4089	+	* which case it is not combined)
4090	+	* @param reducer a commutative associative combining function
4091	+	* @param <U> the return type of the transformer
4092	+	* @return the result of accumulating the given transformation
4093	+	* of all values
4094	+	* @since 1.8
4095	+	*/
4096	+	public <U> U reduceValues(long parallelismThreshold,
4097	+	Function<? super V, ? extends U> transformer,
4098	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
4099	+	if (transformer == null || reducer == null)
4100	+	throw new NullPointerException();
4101	+	return new MapReduceValuesTask<K,V,U>
4102	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4103	+	null, transformer, reducer).invoke();
4104	+	}
4105	+
4106	+	/**
4107	+	* Returns the result of accumulating the given transformation
4108	+	* of all values using the given reducer to combine values,
4109	+	* and the given basis as an identity value.
4110	+	*
4111	+	* @param parallelismThreshold the (estimated) number of elements
4112	+	* needed for this operation to be executed in parallel
4113	+	* @param transformer a function returning the transformation
4114	+	* for an element
4115	+	* @param basis the identity (initial default value) for the reduction
4116	+	* @param reducer a commutative associative combining function
4117	+	* @return the result of accumulating the given transformation
4118	+	* of all values
4119	+	* @since 1.8
4120	+	*/
4121	+	public double reduceValuesToDouble(long parallelismThreshold,
4122	+	ToDoubleFunction<? super V> transformer,
4123	+	double basis,
4124	+	DoubleBinaryOperator reducer) {
4125	+	if (transformer == null || reducer == null)
4126	+	throw new NullPointerException();
4127	+	return new MapReduceValuesToDoubleTask<K,V>
4128	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4129	+	null, transformer, basis, reducer).invoke();
4130		}
4131
4132	<	final class Values extends AbstractCollection<V> {
4133	<	public Iterator<V> iterator() {
4134	<	return new ValueIterator();
4132	>	/**
4133	>	* Returns the result of accumulating the given transformation
4134	>	* of all values using the given reducer to combine values,
4135	>	* and the given basis as an identity value.
4136	>	*
4137	>	* @param parallelismThreshold the (estimated) number of elements
4138	>	* needed for this operation to be executed in parallel
4139	>	* @param transformer a function returning the transformation
4140	>	* for an element
4141	>	* @param basis the identity (initial default value) for the reduction
4142	>	* @param reducer a commutative associative combining function
4143	>	* @return the result of accumulating the given transformation
4144	>	* of all values
4145	>	* @since 1.8
4146	>	*/
4147	>	public long reduceValuesToLong(long parallelismThreshold,
4148	>	ToLongFunction<? super V> transformer,
4149	>	long basis,
4150	>	LongBinaryOperator reducer) {
4151	>	if (transformer == null || reducer == null)
4152	>	throw new NullPointerException();
4153	>	return new MapReduceValuesToLongTask<K,V>
4154	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4155	>	null, transformer, basis, reducer).invoke();
4156	>	}
4157	>
4158	>	/**
4159	>	* Returns the result of accumulating the given transformation
4160	>	* of all values using the given reducer to combine values,
4161	>	* and the given basis as an identity value.
4162	>	*
4163	>	* @param parallelismThreshold the (estimated) number of elements
4164	>	* needed for this operation to be executed in parallel
4165	>	* @param transformer a function returning the transformation
4166	>	* for an element
4167	>	* @param basis the identity (initial default value) for the reduction
4168	>	* @param reducer a commutative associative combining function
4169	>	* @return the result of accumulating the given transformation
4170	>	* of all values
4171	>	* @since 1.8
4172	>	*/
4173	>	public int reduceValuesToInt(long parallelismThreshold,
4174	>	ToIntFunction<? super V> transformer,
4175	>	int basis,
4176	>	IntBinaryOperator reducer) {
4177	>	if (transformer == null || reducer == null)
4178	>	throw new NullPointerException();
4179	>	return new MapReduceValuesToIntTask<K,V>
4180	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4181	>	null, transformer, basis, reducer).invoke();
4182	>	}
4183	>
4184	>	/**
4185	>	* Performs the given action for each entry.
4186	>	*
4187	>	* @param parallelismThreshold the (estimated) number of elements
4188	>	* needed for this operation to be executed in parallel
4189	>	* @param action the action
4190	>	* @since 1.8
4191	>	*/
4192	>	public void forEachEntry(long parallelismThreshold,
4193	>	Consumer<? super Map.Entry<K,V>> action) {
4194	>	if (action == null) throw new NullPointerException();
4195	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4196	>	action).invoke();
4197	>	}
4198	>
4199	>	/**
4200	>	* Performs the given action for each non-null transformation
4201	>	* of each entry.
4202	>	*
4203	>	* @param parallelismThreshold the (estimated) number of elements
4204	>	* needed for this operation to be executed in parallel
4205	>	* @param transformer a function returning the transformation
4206	>	* for an element, or null if there is no transformation (in
4207	>	* which case the action is not applied)
4208	>	* @param action the action
4209	>	* @param <U> the return type of the transformer
4210	>	* @since 1.8
4211	>	*/
4212	>	public <U> void forEachEntry(long parallelismThreshold,
4213	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4214	>	Consumer<? super U> action) {
4215	>	if (transformer == null || action == null)
4216	>	throw new NullPointerException();
4217	>	new ForEachTransformedEntryTask<K,V,U>
4218	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4219	>	transformer, action).invoke();
4220	>	}
4221	>
4222	>	/**
4223	>	* Returns a non-null result from applying the given search
4224	>	* function on each entry, or null if none.  Upon success,
4225	>	* further element processing is suppressed and the results of
4226	>	* any other parallel invocations of the search function are
4227	>	* ignored.
4228	>	*
4229	>	* @param parallelismThreshold the (estimated) number of elements
4230	>	* needed for this operation to be executed in parallel
4231	>	* @param searchFunction a function returning a non-null
4232	>	* result on success, else null
4233	>	* @param <U> the return type of the search function
4234	>	* @return a non-null result from applying the given search
4235	>	* function on each entry, or null if none
4236	>	* @since 1.8
4237	>	*/
4238	>	public <U> U searchEntries(long parallelismThreshold,
4239	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4240	>	if (searchFunction == null) throw new NullPointerException();
4241	>	return new SearchEntriesTask<K,V,U>
4242	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4243	>	searchFunction, new AtomicReference<U>()).invoke();
4244	>	}
4245	>
4246	>	/**
4247	>	* Returns the result of accumulating all entries using the
4248	>	* given reducer to combine values, or null if none.
4249	>	*
4250	>	* @param parallelismThreshold the (estimated) number of elements
4251	>	* needed for this operation to be executed in parallel
4252	>	* @param reducer a commutative associative combining function
4253	>	* @return the result of accumulating all entries
4254	>	* @since 1.8
4255	>	*/
4256	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4257	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4258	>	if (reducer == null) throw new NullPointerException();
4259	>	return new ReduceEntriesTask<K,V>
4260	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4261	>	null, reducer).invoke();
4262	>	}
4263	>
4264	>	/**
4265	>	* Returns the result of accumulating the given transformation
4266	>	* of all entries using the given reducer to combine values,
4267	>	* or null if none.
4268	>	*
4269	>	* @param parallelismThreshold the (estimated) number of elements
4270	>	* needed for this operation to be executed in parallel
4271	>	* @param transformer a function returning the transformation
4272	>	* for an element, or null if there is no transformation (in
4273	>	* which case it is not combined)
4274	>	* @param reducer a commutative associative combining function
4275	>	* @param <U> the return type of the transformer
4276	>	* @return the result of accumulating the given transformation
4277	>	* of all entries
4278	>	* @since 1.8
4279	>	*/
4280	>	public <U> U reduceEntries(long parallelismThreshold,
4281	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4282	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4283	>	if (transformer == null || reducer == null)
4284	>	throw new NullPointerException();
4285	>	return new MapReduceEntriesTask<K,V,U>
4286	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4287	>	null, transformer, reducer).invoke();
4288	>	}
4289	>
4290	>	/**
4291	>	* Returns the result of accumulating the given transformation
4292	>	* of all entries using the given reducer to combine values,
4293	>	* and the given basis as an identity value.
4294	>	*
4295	>	* @param parallelismThreshold the (estimated) number of elements
4296	>	* needed for this operation to be executed in parallel
4297	>	* @param transformer a function returning the transformation
4298	>	* for an element
4299	>	* @param basis the identity (initial default value) for the reduction
4300	>	* @param reducer a commutative associative combining function
4301	>	* @return the result of accumulating the given transformation
4302	>	* of all entries
4303	>	* @since 1.8
4304	>	*/
4305	>	public double reduceEntriesToDouble(long parallelismThreshold,
4306	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4307	>	double basis,
4308	>	DoubleBinaryOperator reducer) {
4309	>	if (transformer == null || reducer == null)
4310	>	throw new NullPointerException();
4311	>	return new MapReduceEntriesToDoubleTask<K,V>
4312	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4313	>	null, transformer, basis, reducer).invoke();
4314	>	}
4315	>
4316	>	/**
4317	>	* Returns the result of accumulating the given transformation
4318	>	* of all entries using the given reducer to combine values,
4319	>	* and the given basis as an identity value.
4320	>	*
4321	>	* @param parallelismThreshold the (estimated) number of elements
4322	>	* needed for this operation to be executed in parallel
4323	>	* @param transformer a function returning the transformation
4324	>	* for an element
4325	>	* @param basis the identity (initial default value) for the reduction
4326	>	* @param reducer a commutative associative combining function
4327	>	* @return the result of accumulating the given transformation
4328	>	* of all entries
4329	>	* @since 1.8
4330	>	*/
4331	>	public long reduceEntriesToLong(long parallelismThreshold,
4332	>	ToLongFunction<Map.Entry<K,V>> transformer,
4333	>	long basis,
4334	>	LongBinaryOperator reducer) {
4335	>	if (transformer == null || reducer == null)
4336	>	throw new NullPointerException();
4337	>	return new MapReduceEntriesToLongTask<K,V>
4338	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4339	>	null, transformer, basis, reducer).invoke();
4340	>	}
4341	>
4342	>	/**
4343	>	* Returns the result of accumulating the given transformation
4344	>	* of all entries using the given reducer to combine values,
4345	>	* and the given basis as an identity value.
4346	>	*
4347	>	* @param parallelismThreshold the (estimated) number of elements
4348	>	* needed for this operation to be executed in parallel
4349	>	* @param transformer a function returning the transformation
4350	>	* for an element
4351	>	* @param basis the identity (initial default value) for the reduction
4352	>	* @param reducer a commutative associative combining function
4353	>	* @return the result of accumulating the given transformation
4354	>	* of all entries
4355	>	* @since 1.8
4356	>	*/
4357	>	public int reduceEntriesToInt(long parallelismThreshold,
4358	>	ToIntFunction<Map.Entry<K,V>> transformer,
4359	>	int basis,
4360	>	IntBinaryOperator reducer) {
4361	>	if (transformer == null || reducer == null)
4362	>	throw new NullPointerException();
4363	>	return new MapReduceEntriesToIntTask<K,V>
4364	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4365	>	null, transformer, basis, reducer).invoke();
4366	>	}
4367	>
4368	>
4369	>	/* ----------------Views -------------- */
4370	>
4371	>	/**
4372	>	* Base class for views.
4373	>	*/
4374	>	abstract static class CollectionView<K,V,E>
4375	>	implements Collection<E>, java.io.Serializable {
4376	>	private static final long serialVersionUID = 7249069246763182397L;
4377	>	final ConcurrentHashMap<K,V> map;
4378	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4379	>
4380	>	/**
4381	>	* Returns the map backing this view.
4382	>	*
4383	>	* @return the map backing this view
4384	>	*/
4385	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4386	>
4387	>	/**
4388	>	* Removes all of the elements from this view, by removing all
4389	>	* the mappings from the map backing this view.
4390	>	*/
4391	>	public final void clear()      { map.clear(); }
4392	>	public final int size()        { return map.size(); }
4393	>	public final boolean isEmpty() { return map.isEmpty(); }
4394	>
4395	>	// implementations below rely on concrete classes supplying these
4396	>	// abstract methods
4397	>	/**
4398	>	* Returns an iterator over the elements in this collection.
4399	>	*
4400	>	* <p>The returned iterator is
4401	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4402	>	*
4403	>	* @return an iterator over the elements in this collection
4404	>	*/
4405	>	public abstract Iterator<E> iterator();
4406	>	public abstract boolean contains(Object o);
4407	>	public abstract boolean remove(Object o);
4408	>
4409	>	private static final String oomeMsg = "Required array size too large";
4410	>
4411	>	public final Object[] toArray() {
4412	>	long sz = map.mappingCount();
4413	>	if (sz > MAX_ARRAY_SIZE)
4414	>	throw new OutOfMemoryError(oomeMsg);
4415	>	int n = (int)sz;
4416	>	Object[] r = new Object[n];
4417	>	int i = 0;
4418	>	for (E e : this) {
4419	>	if (i == n) {
4420	>	if (n >= MAX_ARRAY_SIZE)
4421	>	throw new OutOfMemoryError(oomeMsg);
4422	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4423	>	n = MAX_ARRAY_SIZE;
4424	>	else
4425	>	n += (n >>> 1) + 1;
4426	>	r = Arrays.copyOf(r, n);
4427	>	}
4428	>	r[i++] = e;
4429	>	}
4430	>	return (i == n) ? r : Arrays.copyOf(r, i);
4431		}
4432	<	public int size() {
4433	<	return ConcurrentHashMap.this.size();
4432	>
4433	>	@SuppressWarnings("unchecked")
4434	>	public final <T> T[] toArray(T[] a) {
4435	>	long sz = map.mappingCount();
4436	>	if (sz > MAX_ARRAY_SIZE)
4437	>	throw new OutOfMemoryError(oomeMsg);
4438	>	int m = (int)sz;
4439	>	T[] r = (a.length >= m) ? a :
4440	>	(T[])java.lang.reflect.Array
4441	>	.newInstance(a.getClass().getComponentType(), m);
4442	>	int n = r.length;
4443	>	int i = 0;
4444	>	for (E e : this) {
4445	>	if (i == n) {
4446	>	if (n >= MAX_ARRAY_SIZE)
4447	>	throw new OutOfMemoryError(oomeMsg);
4448	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4449	>	n = MAX_ARRAY_SIZE;
4450	>	else
4451	>	n += (n >>> 1) + 1;
4452	>	r = Arrays.copyOf(r, n);
4453	>	}
4454	>	r[i++] = (T)e;
4455	>	}
4456	>	if (a == r && i < n) {
4457	>	r[i] = null; // null-terminate
4458	>	return r;
4459	>	}
4460	>	return (i == n) ? r : Arrays.copyOf(r, i);
4461		}
4462	<	public boolean isEmpty() {
4463	<	return ConcurrentHashMap.this.isEmpty();
4462	>
4463	>	/**
4464	>	* Returns a string representation of this collection.
4465	>	* The string representation consists of the string representations
4466	>	* of the collection's elements in the order they are returned by
4467	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4468	>	* Adjacent elements are separated by the characters {@code ", "}
4469	>	* (comma and space).  Elements are converted to strings as by
4470	>	* {@link String#valueOf(Object)}.
4471	>	*
4472	>	* @return a string representation of this collection
4473	>	*/
4474	>	public final String toString() {
4475	>	StringBuilder sb = new StringBuilder();
4476	>	sb.append('[');
4477	>	Iterator<E> it = iterator();
4478	>	if (it.hasNext()) {
4479	>	for (;;) {
4480	>	Object e = it.next();
4481	>	sb.append(e == this ? "(this Collection)" : e);
4482	>	if (!it.hasNext())
4483	>	break;
4484	>	sb.append(',').append(' ');
4485	>	}
4486	>	}
4487	>	return sb.append(']').toString();
4488		}
4489	<	public boolean contains(Object o) {
4490	<	return ConcurrentHashMap.this.containsValue(o);
4489	>
4490	>	public final boolean containsAll(Collection<?> c) {
4491	>	if (c != this) {
4492	>	for (Object e : c) {
4493	>	if (e == null || !contains(e))
4494	>	return false;
4495	>	}
4496	>	}
4497	>	return true;
4498		}
4499	<	public void clear() {
4500	<	ConcurrentHashMap.this.clear();
4499	>
4500	>	public final boolean removeAll(Collection<?> c) {
4501	>	if (c == null) throw new NullPointerException();
4502	>	boolean modified = false;
4503	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4504	>	if (c.contains(it.next())) {
4505	>	it.remove();
4506	>	modified = true;
4507	>	}
4508	>	}
4509	>	return modified;
4510		}
4511	+
4512	+	public final boolean retainAll(Collection<?> c) {
4513	+	if (c == null) throw new NullPointerException();
4514	+	boolean modified = false;
4515	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4516	+	if (!c.contains(it.next())) {
4517	+	it.remove();
4518	+	modified = true;
4519	+	}
4520	+	}
4521	+	return modified;
4522	+	}
4523	+
4524		}
4525
4526	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4527	<	public Iterator<Map.Entry<K,V>> iterator() {
4528	<	return new EntryIterator();
4526	>	/**
4527	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4528	>	* which additions may optionally be enabled by mapping to a
4529	>	* common value.  This class cannot be directly instantiated.
4530	>	* See {@link #keySet() keySet()},
4531	>	* {@link #keySet(Object) keySet(V)},
4532	>	* {@link #newKeySet() newKeySet()},
4533	>	* {@link #newKeySet(int) newKeySet(int)}.
4534	>	*
4535	>	* @since 1.8
4536	>	*/
4537	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4538	>	implements Set<K>, java.io.Serializable {
4539	>	private static final long serialVersionUID = 7249069246763182397L;
4540	>	private final V value;
4541	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4542	>	super(map);
4543	>	this.value = value;
4544	>	}
4545	>
4546	>	/**
4547	>	* Returns the default mapped value for additions,
4548	>	* or {@code null} if additions are not supported.
4549	>	*
4550	>	* @return the default mapped value for additions, or {@code null}
4551	>	* if not supported
4552	>	*/
4553	>	public V getMappedValue() { return value; }
4554	>
4555	>	/**
4556	>	* {@inheritDoc}
4557	>	* @throws NullPointerException if the specified key is null
4558	>	*/
4559	>	public boolean contains(Object o) { return map.containsKey(o); }
4560	>
4561	>	/**
4562	>	* Removes the key from this map view, by removing the key (and its
4563	>	* corresponding value) from the backing map.  This method does
4564	>	* nothing if the key is not in the map.
4565	>	*
4566	>	* @param  o the key to be removed from the backing map
4567	>	* @return {@code true} if the backing map contained the specified key
4568	>	* @throws NullPointerException if the specified key is null
4569	>	*/
4570	>	public boolean remove(Object o) { return map.remove(o) != null; }
4571	>
4572	>	/**
4573	>	* @return an iterator over the keys of the backing map
4574	>	*/
4575	>	public Iterator<K> iterator() {
4576	>	Node<K,V>[] t;
4577	>	ConcurrentHashMap<K,V> m = map;
4578	>	int f = (t = m.table) == null ? 0 : t.length;
4579	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4580	>	}
4581	>
4582	>	/**
4583	>	* Adds the specified key to this set view by mapping the key to
4584	>	* the default mapped value in the backing map, if defined.
4585	>	*
4586	>	* @param e key to be added
4587	>	* @return {@code true} if this set changed as a result of the call
4588	>	* @throws NullPointerException if the specified key is null
4589	>	* @throws UnsupportedOperationException if no default mapped value
4590	>	* for additions was provided
4591	>	*/
4592	>	public boolean add(K e) {
4593	>	V v;
4594	>	if ((v = value) == null)
4595	>	throw new UnsupportedOperationException();
4596	>	return map.putVal(e, v, true) == null;
4597	>	}
4598	>
4599	>	/**
4600	>	* Adds all of the elements in the specified collection to this set,
4601	>	* as if by calling {@link #add} on each one.
4602	>	*
4603	>	* @param c the elements to be inserted into this set
4604	>	* @return {@code true} if this set changed as a result of the call
4605	>	* @throws NullPointerException if the collection or any of its
4606	>	* elements are {@code null}
4607	>	* @throws UnsupportedOperationException if no default mapped value
4608	>	* for additions was provided
4609	>	*/
4610	>	public boolean addAll(Collection<? extends K> c) {
4611	>	boolean added = false;
4612	>	V v;
4613	>	if ((v = value) == null)
4614	>	throw new UnsupportedOperationException();
4615	>	for (K e : c) {
4616	>	if (map.putVal(e, v, true) == null)
4617	>	added = true;
4618	>	}
4619	>	return added;
4620	>	}
4621	>
4622	>	public int hashCode() {
4623	>	int h = 0;
4624	>	for (K e : this)
4625	>	h += e.hashCode();
4626	>	return h;
4627	>	}
4628	>
4629	>	public boolean equals(Object o) {
4630	>	Set<?> c;
4631	>	return ((o instanceof Set) &&
4632	>	((c = (Set<?>)o) == this ||
4633	>	(containsAll(c) && c.containsAll(this))));
4634	>	}
4635	>
4636	>	public Spliterator<K> spliterator() {
4637	>	Node<K,V>[] t;
4638	>	ConcurrentHashMap<K,V> m = map;
4639	>	long n = m.sumCount();
4640	>	int f = (t = m.table) == null ? 0 : t.length;
4641	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4642	>	}
4643	>
4644	>	public void forEach(Consumer<? super K> action) {
4645	>	if (action == null) throw new NullPointerException();
4646	>	Node<K,V>[] t;
4647	>	if ((t = map.table) != null) {
4648	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4649	>	for (Node<K,V> p; (p = it.advance()) != null; )
4650	>	action.accept(p.key);
4651	>	}
4652	>	}
4653	>	}
4654	>
4655	>	/**
4656	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4657	>	* values, in which additions are disabled. This class cannot be
4658	>	* directly instantiated. See {@link #values()}.
4659	>	*/
4660	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4661	>	implements Collection<V>, java.io.Serializable {
4662	>	private static final long serialVersionUID = 2249069246763182397L;
4663	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4664	>	public final boolean contains(Object o) {
4665	>	return map.containsValue(o);
4666	>	}
4667	>
4668	>	public final boolean remove(Object o) {
4669	>	if (o != null) {
4670	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4671	>	if (o.equals(it.next())) {
4672	>	it.remove();
4673	>	return true;
4674	>	}
4675	>	}
4676	>	}
4677	>	return false;
4678	>	}
4679	>
4680	>	public final Iterator<V> iterator() {
4681	>	ConcurrentHashMap<K,V> m = map;
4682	>	Node<K,V>[] t;
4683	>	int f = (t = m.table) == null ? 0 : t.length;
4684	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4685		}
4686	+
4687	+	public final boolean add(V e) {
4688	+	throw new UnsupportedOperationException();
4689	+	}
4690	+	public final boolean addAll(Collection<? extends V> c) {
4691	+	throw new UnsupportedOperationException();
4692	+	}
4693	+
4694	+	public Spliterator<V> spliterator() {
4695	+	Node<K,V>[] t;
4696	+	ConcurrentHashMap<K,V> m = map;
4697	+	long n = m.sumCount();
4698	+	int f = (t = m.table) == null ? 0 : t.length;
4699	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4700	+	}
4701	+
4702	+	public void forEach(Consumer<? super V> action) {
4703	+	if (action == null) throw new NullPointerException();
4704	+	Node<K,V>[] t;
4705	+	if ((t = map.table) != null) {
4706	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4707	+	for (Node<K,V> p; (p = it.advance()) != null; )
4708	+	action.accept(p.val);
4709	+	}
4710	+	}
4711	+	}
4712	+
4713	+	/**
4714	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4715	+	* entries.  This class cannot be directly instantiated. See
4716	+	* {@link #entrySet()}.
4717	+	*/
4718	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4719	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4720	+	private static final long serialVersionUID = 2249069246763182397L;
4721	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4722	+
4723		public boolean contains(Object o) {
4724	<	if (!(o instanceof Map.Entry))
4725	<	return false;
4726	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4727	<	V v = ConcurrentHashMap.this.get(e.getKey());
4728	<	return v != null && v.equals(e.getValue());
4724	>	Object k, v, r; Map.Entry<?,?> e;
4725	>	return ((o instanceof Map.Entry) &&
4726	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4727	>	(r = map.get(k)) != null &&
4728	>	(v = e.getValue()) != null &&
4729	>	(v == r || v.equals(r)));
4730		}
4731	+
4732		public boolean remove(Object o) {
4733	<	if (!(o instanceof Map.Entry))
4734	<	return false;
4735	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4736	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4733	>	Object k, v; Map.Entry<?,?> e;
4734	>	return ((o instanceof Map.Entry) &&
4735	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4736	>	(v = e.getValue()) != null &&
4737	>	map.remove(k, v));
4738		}
4739	<	public int size() {
4740	<	return ConcurrentHashMap.this.size();
4739	>
4740	>	/**
4741	>	* @return an iterator over the entries of the backing map
4742	>	*/
4743	>	public Iterator<Map.Entry<K,V>> iterator() {
4744	>	ConcurrentHashMap<K,V> m = map;
4745	>	Node<K,V>[] t;
4746	>	int f = (t = m.table) == null ? 0 : t.length;
4747	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4748		}
4749	<	public boolean isEmpty() {
4750	<	return ConcurrentHashMap.this.isEmpty();
4749	>
4750	>	public boolean add(Entry<K,V> e) {
4751	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4752		}
4753	<	public void clear() {
4754	<	ConcurrentHashMap.this.clear();
4753	>
4754	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4755	>	boolean added = false;
4756	>	for (Entry<K,V> e : c) {
4757	>	if (add(e))
4758	>	added = true;
4759	>	}
4760	>	return added;
4761		}
4762	+
4763	+	public boolean removeIf(Predicate<? super Entry<K, V>> filter) {
4764	+	return map.removeEntryIf(filter);
4765	+	}
4766	+
4767	+	public final int hashCode() {
4768	+	int h = 0;
4769	+	Node<K,V>[] t;
4770	+	if ((t = map.table) != null) {
4771	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4772	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
4773	+	h += p.hashCode();
4774	+	}
4775	+	}
4776	+	return h;
4777	+	}
4778	+
4779	+	public final boolean equals(Object o) {
4780	+	Set<?> c;
4781	+	return ((o instanceof Set) &&
4782	+	((c = (Set<?>)o) == this ||
4783	+	(containsAll(c) && c.containsAll(this))));
4784	+	}
4785	+
4786	+	public Spliterator<Map.Entry<K,V>> spliterator() {
4787	+	Node<K,V>[] t;
4788	+	ConcurrentHashMap<K,V> m = map;
4789	+	long n = m.sumCount();
4790	+	int f = (t = m.table) == null ? 0 : t.length;
4791	+	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4792	+	}
4793	+
4794	+	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4795	+	if (action == null) throw new NullPointerException();
4796	+	Node<K,V>[] t;
4797	+	if ((t = map.table) != null) {
4798	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4799	+	for (Node<K,V> p; (p = it.advance()) != null; )
4800	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4801	+	}
4802	+	}
4803	+
4804		}
4805
4806	<	/* ---------------- Serialization Support -------------- */
4806	>	// -------------------------------------------------------
4807
4808		/**
4809	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4810	<	* stream (i.e., serializes it).
1402	<	* @param s the stream
1403	<	* @serialData
1404	<	* the key (Object) and value (Object)
1405	<	* for each key-value mapping, followed by a null pair.
1406	<	* The key-value mappings are emitted in no particular order.
4809	>	* Base class for bulk tasks. Repeats some fields and code from
4810	>	* class Traverser, because we need to subclass CountedCompleter.
4811		*/
4812	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4813	<	// force all segments for serialization compatibility
4814	<	for (int k = 0; k < segments.length; ++k)
4815	<	ensureSegment(k);
4816	<	s.defaultWriteObject();
4817	<
4818	<	final Segment<K,V>[] segments = this.segments;
4819	<	for (int k = 0; k < segments.length; ++k) {
4820	<	Segment<K,V> seg = segmentAt(segments, k);
4821	<	seg.lock();
4822	<	try {
4823	<	HashEntry<K,V>[] tab = seg.table;
4824	<	for (int i = 0; i < tab.length; ++i) {
4825	<	HashEntry<K,V> e;
4826	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4827	<	s.writeObject(e.key);
4828	<	s.writeObject(e.value);
4812	>	@SuppressWarnings("serial")
4813	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4814	>	Node<K,V>[] tab;        // same as Traverser
4815	>	Node<K,V> next;
4816	>	TableStack<K,V> stack, spare;
4817	>	int index;
4818	>	int baseIndex;
4819	>	int baseLimit;
4820	>	final int baseSize;
4821	>	int batch;              // split control
4822	>
4823	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4824	>	super(par);
4825	>	this.batch = b;
4826	>	this.index = this.baseIndex = i;
4827	>	if ((this.tab = t) == null)
4828	>	this.baseSize = this.baseLimit = 0;
4829	>	else if (par == null)
4830	>	this.baseSize = this.baseLimit = t.length;
4831	>	else {
4832	>	this.baseLimit = f;
4833	>	this.baseSize = par.baseSize;
4834	>	}
4835	>	}
4836	>
4837	>	/**
4838	>	* Same as Traverser version
4839	>	*/
4840	>	final Node<K,V> advance() {
4841	>	Node<K,V> e;
4842	>	if ((e = next) != null)
4843	>	e = e.next;
4844	>	for (;;) {
4845	>	Node<K,V>[] t; int i, n;
4846	>	if (e != null)
4847	>	return next = e;
4848	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4849	>	(n = t.length) <= (i = index) || i < 0)
4850	>	return next = null;
4851	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4852	>	if (e instanceof ForwardingNode) {
4853	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4854	>	e = null;
4855	>	pushState(t, i, n);
4856	>	continue;
4857		}
4858	+	else if (e instanceof TreeBin)
4859	+	e = ((TreeBin<K,V>)e).first;
4860	+	else
4861	+	e = null;
4862		}
4863	<	} finally {
4864	<	seg.unlock();
4863	>	if (stack != null)
4864	>	recoverState(n);
4865	>	else if ((index = i + baseSize) >= n)
4866	>	index = ++baseIndex;
4867		}
4868		}
4869	<	s.writeObject(null);
4870	<	s.writeObject(null);
4869	>
4870	>	private void pushState(Node<K,V>[] t, int i, int n) {
4871	>	TableStack<K,V> s = spare;
4872	>	if (s != null)
4873	>	spare = s.next;
4874	>	else
4875	>	s = new TableStack<K,V>();
4876	>	s.tab = t;
4877	>	s.length = n;
4878	>	s.index = i;
4879	>	s.next = stack;
4880	>	stack = s;
4881	>	}
4882	>
4883	>	private void recoverState(int n) {
4884	>	TableStack<K,V> s; int len;
4885	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4886	>	n = len;
4887	>	index = s.index;
4888	>	tab = s.tab;
4889	>	s.tab = null;
4890	>	TableStack<K,V> next = s.next;
4891	>	s.next = spare; // save for reuse
4892	>	stack = next;
4893	>	spare = s;
4894	>	}
4895	>	if (s == null && (index += baseSize) >= n)
4896	>	index = ++baseIndex;
4897	>	}
4898		}
4899
4900	<	/**
4901	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4902	<	* stream (i.e., deserializes it).
4903	<	* @param s the stream
4904	<	*/
4905	<	@SuppressWarnings("unchecked")
4906	<	private void readObject(java.io.ObjectInputStream s)
4907	<	throws IOException, ClassNotFoundException {
4908	<	s.defaultReadObject();
4900	>	/*
4901	>	* Task classes. Coded in a regular but ugly format/style to
4902	>	* simplify checks that each variant differs in the right way from
4903	>	* others. The null screenings exist because compilers cannot tell
4904	>	* that we've already null-checked task arguments, so we force
4905	>	* simplest hoisted bypass to help avoid convoluted traps.
4906	>	*/
4907	>	@SuppressWarnings("serial")
4908	>	static final class ForEachKeyTask<K,V>
4909	>	extends BulkTask<K,V,Void> {
4910	>	final Consumer<? super K> action;
4911	>	ForEachKeyTask
4912	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4913	>	Consumer<? super K> action) {
4914	>	super(p, b, i, f, t);
4915	>	this.action = action;
4916	>	}
4917	>	public final void compute() {
4918	>	final Consumer<? super K> action;
4919	>	if ((action = this.action) != null) {
4920	>	for (int i = baseIndex, f, h; batch > 0 &&
4921	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4922	>	addToPendingCount(1);
4923	>	new ForEachKeyTask<K,V>
4924	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4925	>	action).fork();
4926	>	}
4927	>	for (Node<K,V> p; (p = advance()) != null;)
4928	>	action.accept(p.key);
4929	>	propagateCompletion();
4930	>	}
4931	>	}
4932	>	}
4933
4934	<	// Re-initialize segments to be minimally sized, and let grow.
4935	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4936	<	final Segment<K,V>[] segments = this.segments;
4937	<	for (int k = 0; k < segments.length; ++k) {
4938	<	Segment<K,V> seg = segments[k];
4939	<	if (seg != null) {
4940	<	seg.threshold = (int)(cap * seg.loadFactor);
4941	<	seg.table = (HashEntry<K,V>[]) new HashEntry[cap];
4934	>	@SuppressWarnings("serial")
4935	>	static final class ForEachValueTask<K,V>
4936	>	extends BulkTask<K,V,Void> {
4937	>	final Consumer<? super V> action;
4938	>	ForEachValueTask
4939	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4940	>	Consumer<? super V> action) {
4941	>	super(p, b, i, f, t);
4942	>	this.action = action;
4943	>	}
4944	>	public final void compute() {
4945	>	final Consumer<? super V> action;
4946	>	if ((action = this.action) != null) {
4947	>	for (int i = baseIndex, f, h; batch > 0 &&
4948	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4949	>	addToPendingCount(1);
4950	>	new ForEachValueTask<K,V>
4951	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4952	>	action).fork();
4953	>	}
4954	>	for (Node<K,V> p; (p = advance()) != null;)
4955	>	action.accept(p.val);
4956	>	propagateCompletion();
4957		}
4958		}
4959	+	}
4960
4961	<	// Read the keys and values, and put the mappings in the table
4962	<	for (;;) {
4963	<	K key = (K) s.readObject();
4964	<	V value = (V) s.readObject();
4965	<	if (key == null)
4966	<	break;
4967	<	put(key, value);
4961	>	@SuppressWarnings("serial")
4962	>	static final class ForEachEntryTask<K,V>
4963	>	extends BulkTask<K,V,Void> {
4964	>	final Consumer<? super Entry<K,V>> action;
4965	>	ForEachEntryTask
4966	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4967	>	Consumer<? super Entry<K,V>> action) {
4968	>	super(p, b, i, f, t);
4969	>	this.action = action;
4970	>	}
4971	>	public final void compute() {
4972	>	final Consumer<? super Entry<K,V>> action;
4973	>	if ((action = this.action) != null) {
4974	>	for (int i = baseIndex, f, h; batch > 0 &&
4975	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4976	>	addToPendingCount(1);
4977	>	new ForEachEntryTask<K,V>
4978	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4979	>	action).fork();
4980	>	}
4981	>	for (Node<K,V> p; (p = advance()) != null; )
4982	>	action.accept(p);
4983	>	propagateCompletion();
4984	>	}
4985	>	}
4986	>	}
4987	>
4988	>	@SuppressWarnings("serial")
4989	>	static final class ForEachMappingTask<K,V>
4990	>	extends BulkTask<K,V,Void> {
4991	>	final BiConsumer<? super K, ? super V> action;
4992	>	ForEachMappingTask
4993	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4994	>	BiConsumer<? super K,? super V> action) {
4995	>	super(p, b, i, f, t);
4996	>	this.action = action;
4997	>	}
4998	>	public final void compute() {
4999	>	final BiConsumer<? super K, ? super V> action;
5000	>	if ((action = this.action) != null) {
5001	>	for (int i = baseIndex, f, h; batch > 0 &&
5002	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5003	>	addToPendingCount(1);
5004	>	new ForEachMappingTask<K,V>
5005	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5006	>	action).fork();
5007	>	}
5008	>	for (Node<K,V> p; (p = advance()) != null; )
5009	>	action.accept(p.key, p.val);
5010	>	propagateCompletion();
5011	>	}
5012	>	}
5013	>	}
5014	>
5015	>	@SuppressWarnings("serial")
5016	>	static final class ForEachTransformedKeyTask<K,V,U>
5017	>	extends BulkTask<K,V,Void> {
5018	>	final Function<? super K, ? extends U> transformer;
5019	>	final Consumer<? super U> action;
5020	>	ForEachTransformedKeyTask
5021	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5022	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
5023	>	super(p, b, i, f, t);
5024	>	this.transformer = transformer; this.action = action;
5025	>	}
5026	>	public final void compute() {
5027	>	final Function<? super K, ? extends U> transformer;
5028	>	final Consumer<? super U> action;
5029	>	if ((transformer = this.transformer) != null &&
5030	>	(action = this.action) != null) {
5031	>	for (int i = baseIndex, f, h; batch > 0 &&
5032	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5033	>	addToPendingCount(1);
5034	>	new ForEachTransformedKeyTask<K,V,U>
5035	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5036	>	transformer, action).fork();
5037	>	}
5038	>	for (Node<K,V> p; (p = advance()) != null; ) {
5039	>	U u;
5040	>	if ((u = transformer.apply(p.key)) != null)
5041	>	action.accept(u);
5042	>	}
5043	>	propagateCompletion();
5044	>	}
5045	>	}
5046	>	}
5047	>
5048	>	@SuppressWarnings("serial")
5049	>	static final class ForEachTransformedValueTask<K,V,U>
5050	>	extends BulkTask<K,V,Void> {
5051	>	final Function<? super V, ? extends U> transformer;
5052	>	final Consumer<? super U> action;
5053	>	ForEachTransformedValueTask
5054	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5055	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5056	>	super(p, b, i, f, t);
5057	>	this.transformer = transformer; this.action = action;
5058	>	}
5059	>	public final void compute() {
5060	>	final Function<? super V, ? extends U> transformer;
5061	>	final Consumer<? super U> action;
5062	>	if ((transformer = this.transformer) != null &&
5063	>	(action = this.action) != null) {
5064	>	for (int i = baseIndex, f, h; batch > 0 &&
5065	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5066	>	addToPendingCount(1);
5067	>	new ForEachTransformedValueTask<K,V,U>
5068	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5069	>	transformer, action).fork();
5070	>	}
5071	>	for (Node<K,V> p; (p = advance()) != null; ) {
5072	>	U u;
5073	>	if ((u = transformer.apply(p.val)) != null)
5074	>	action.accept(u);
5075	>	}
5076	>	propagateCompletion();
5077	>	}
5078	>	}
5079	>	}
5080	>
5081	>	@SuppressWarnings("serial")
5082	>	static final class ForEachTransformedEntryTask<K,V,U>
5083	>	extends BulkTask<K,V,Void> {
5084	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5085	>	final Consumer<? super U> action;
5086	>	ForEachTransformedEntryTask
5087	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5088	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5089	>	super(p, b, i, f, t);
5090	>	this.transformer = transformer; this.action = action;
5091	>	}
5092	>	public final void compute() {
5093	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5094	>	final Consumer<? super U> action;
5095	>	if ((transformer = this.transformer) != null &&
5096	>	(action = this.action) != null) {
5097	>	for (int i = baseIndex, f, h; batch > 0 &&
5098	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5099	>	addToPendingCount(1);
5100	>	new ForEachTransformedEntryTask<K,V,U>
5101	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5102	>	transformer, action).fork();
5103	>	}
5104	>	for (Node<K,V> p; (p = advance()) != null; ) {
5105	>	U u;
5106	>	if ((u = transformer.apply(p)) != null)
5107	>	action.accept(u);
5108	>	}
5109	>	propagateCompletion();
5110	>	}
5111	>	}
5112	>	}
5113	>
5114	>	@SuppressWarnings("serial")
5115	>	static final class ForEachTransformedMappingTask<K,V,U>
5116	>	extends BulkTask<K,V,Void> {
5117	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5118	>	final Consumer<? super U> action;
5119	>	ForEachTransformedMappingTask
5120	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5121	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5122	>	Consumer<? super U> action) {
5123	>	super(p, b, i, f, t);
5124	>	this.transformer = transformer; this.action = action;
5125	>	}
5126	>	public final void compute() {
5127	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5128	>	final Consumer<? super U> action;
5129	>	if ((transformer = this.transformer) != null &&
5130	>	(action = this.action) != null) {
5131	>	for (int i = baseIndex, f, h; batch > 0 &&
5132	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5133	>	addToPendingCount(1);
5134	>	new ForEachTransformedMappingTask<K,V,U>
5135	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5136	>	transformer, action).fork();
5137	>	}
5138	>	for (Node<K,V> p; (p = advance()) != null; ) {
5139	>	U u;
5140	>	if ((u = transformer.apply(p.key, p.val)) != null)
5141	>	action.accept(u);
5142	>	}
5143	>	propagateCompletion();
5144	>	}
5145	>	}
5146	>	}
5147	>
5148	>	@SuppressWarnings("serial")
5149	>	static final class SearchKeysTask<K,V,U>
5150	>	extends BulkTask<K,V,U> {
5151	>	final Function<? super K, ? extends U> searchFunction;
5152	>	final AtomicReference<U> result;
5153	>	SearchKeysTask
5154	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5155	>	Function<? super K, ? extends U> searchFunction,
5156	>	AtomicReference<U> result) {
5157	>	super(p, b, i, f, t);
5158	>	this.searchFunction = searchFunction; this.result = result;
5159	>	}
5160	>	public final U getRawResult() { return result.get(); }
5161	>	public final void compute() {
5162	>	final Function<? super K, ? extends U> searchFunction;
5163	>	final AtomicReference<U> result;
5164	>	if ((searchFunction = this.searchFunction) != null &&
5165	>	(result = this.result) != null) {
5166	>	for (int i = baseIndex, f, h; batch > 0 &&
5167	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5168	>	if (result.get() != null)
5169	>	return;
5170	>	addToPendingCount(1);
5171	>	new SearchKeysTask<K,V,U>
5172	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5173	>	searchFunction, result).fork();
5174	>	}
5175	>	while (result.get() == null) {
5176	>	U u;
5177	>	Node<K,V> p;
5178	>	if ((p = advance()) == null) {
5179	>	propagateCompletion();
5180	>	break;
5181	>	}
5182	>	if ((u = searchFunction.apply(p.key)) != null) {
5183	>	if (result.compareAndSet(null, u))
5184	>	quietlyCompleteRoot();
5185	>	break;
5186	>	}
5187	>	}
5188	>	}
5189	>	}
5190	>	}
5191	>
5192	>	@SuppressWarnings("serial")
5193	>	static final class SearchValuesTask<K,V,U>
5194	>	extends BulkTask<K,V,U> {
5195	>	final Function<? super V, ? extends U> searchFunction;
5196	>	final AtomicReference<U> result;
5197	>	SearchValuesTask
5198	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5199	>	Function<? super V, ? 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 V, ? 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 SearchValuesTask<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.val)) != null) {
5227	>	if (result.compareAndSet(null, u))
5228	>	quietlyCompleteRoot();
5229	>	break;
5230	>	}
5231	>	}
5232	>	}
5233	>	}
5234	>	}
5235	>
5236	>	@SuppressWarnings("serial")
5237	>	static final class SearchEntriesTask<K,V,U>
5238	>	extends BulkTask<K,V,U> {
5239	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5240	>	final AtomicReference<U> result;
5241	>	SearchEntriesTask
5242	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5243	>	Function<Entry<K,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<Entry<K,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 SearchEntriesTask<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)) != null) {
5271	>	if (result.compareAndSet(null, u))
5272	>	quietlyCompleteRoot();
5273	>	return;
5274	>	}
5275	>	}
5276	>	}
5277	>	}
5278	>	}
5279	>
5280	>	@SuppressWarnings("serial")
5281	>	static final class SearchMappingsTask<K,V,U>
5282	>	extends BulkTask<K,V,U> {
5283	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5284	>	final AtomicReference<U> result;
5285	>	SearchMappingsTask
5286	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5287	>	BiFunction<? super K, ? super 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 BiFunction<? super K, ? super 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 SearchMappingsTask<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.key, p.val)) != null) {
5315	>	if (result.compareAndSet(null, u))
5316	>	quietlyCompleteRoot();
5317	>	break;
5318	>	}
5319	>	}
5320	>	}
5321	>	}
5322	>	}
5323	>
5324	>	@SuppressWarnings("serial")
5325	>	static final class ReduceKeysTask<K,V>
5326	>	extends BulkTask<K,V,K> {
5327	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5328	>	K result;
5329	>	ReduceKeysTask<K,V> rights, nextRight;
5330	>	ReduceKeysTask
5331	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5332	>	ReduceKeysTask<K,V> nextRight,
5333	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5334	>	super(p, b, i, f, t); this.nextRight = nextRight;
5335	>	this.reducer = reducer;
5336	>	}
5337	>	public final K getRawResult() { return result; }
5338	>	public final void compute() {
5339	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5340	>	if ((reducer = this.reducer) != null) {
5341	>	for (int i = baseIndex, f, h; batch > 0 &&
5342	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5343	>	addToPendingCount(1);
5344	>	(rights = new ReduceKeysTask<K,V>
5345	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5346	>	rights, reducer)).fork();
5347	>	}
5348	>	K r = null;
5349	>	for (Node<K,V> p; (p = advance()) != null; ) {
5350	>	K u = p.key;
5351	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5352	>	}
5353	>	result = r;
5354	>	CountedCompleter<?> c;
5355	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5356	>	@SuppressWarnings("unchecked")
5357	>	ReduceKeysTask<K,V>
5358	>	t = (ReduceKeysTask<K,V>)c,
5359	>	s = t.rights;
5360	>	while (s != null) {
5361	>	K tr, sr;
5362	>	if ((sr = s.result) != null)
5363	>	t.result = (((tr = t.result) == null) ? sr :
5364	>	reducer.apply(tr, sr));
5365	>	s = t.rights = s.nextRight;
5366	>	}
5367	>	}
5368	>	}
5369	>	}
5370	>	}
5371	>
5372	>	@SuppressWarnings("serial")
5373	>	static final class ReduceValuesTask<K,V>
5374	>	extends BulkTask<K,V,V> {
5375	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5376	>	V result;
5377	>	ReduceValuesTask<K,V> rights, nextRight;
5378	>	ReduceValuesTask
5379	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5380	>	ReduceValuesTask<K,V> nextRight,
5381	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5382	>	super(p, b, i, f, t); this.nextRight = nextRight;
5383	>	this.reducer = reducer;
5384	>	}
5385	>	public final V getRawResult() { return result; }
5386	>	public final void compute() {
5387	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5388	>	if ((reducer = this.reducer) != null) {
5389	>	for (int i = baseIndex, f, h; batch > 0 &&
5390	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5391	>	addToPendingCount(1);
5392	>	(rights = new ReduceValuesTask<K,V>
5393	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5394	>	rights, reducer)).fork();
5395	>	}
5396	>	V r = null;
5397	>	for (Node<K,V> p; (p = advance()) != null; ) {
5398	>	V v = p.val;
5399	>	r = (r == null) ? v : reducer.apply(r, v);
5400	>	}
5401	>	result = r;
5402	>	CountedCompleter<?> c;
5403	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5404	>	@SuppressWarnings("unchecked")
5405	>	ReduceValuesTask<K,V>
5406	>	t = (ReduceValuesTask<K,V>)c,
5407	>	s = t.rights;
5408	>	while (s != null) {
5409	>	V tr, sr;
5410	>	if ((sr = s.result) != null)
5411	>	t.result = (((tr = t.result) == null) ? sr :
5412	>	reducer.apply(tr, sr));
5413	>	s = t.rights = s.nextRight;
5414	>	}
5415	>	}
5416	>	}
5417	>	}
5418	>	}
5419	>
5420	>	@SuppressWarnings("serial")
5421	>	static final class ReduceEntriesTask<K,V>
5422	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5423	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5424	>	Map.Entry<K,V> result;
5425	>	ReduceEntriesTask<K,V> rights, nextRight;
5426	>	ReduceEntriesTask
5427	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5428	>	ReduceEntriesTask<K,V> nextRight,
5429	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5430	>	super(p, b, i, f, t); this.nextRight = nextRight;
5431	>	this.reducer = reducer;
5432	>	}
5433	>	public final Map.Entry<K,V> getRawResult() { return result; }
5434	>	public final void compute() {
5435	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5436	>	if ((reducer = this.reducer) != null) {
5437	>	for (int i = baseIndex, f, h; batch > 0 &&
5438	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5439	>	addToPendingCount(1);
5440	>	(rights = new ReduceEntriesTask<K,V>
5441	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5442	>	rights, reducer)).fork();
5443	>	}
5444	>	Map.Entry<K,V> r = null;
5445	>	for (Node<K,V> p; (p = advance()) != null; )
5446	>	r = (r == null) ? p : reducer.apply(r, p);
5447	>	result = r;
5448	>	CountedCompleter<?> c;
5449	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5450	>	@SuppressWarnings("unchecked")
5451	>	ReduceEntriesTask<K,V>
5452	>	t = (ReduceEntriesTask<K,V>)c,
5453	>	s = t.rights;
5454	>	while (s != null) {
5455	>	Map.Entry<K,V> tr, sr;
5456	>	if ((sr = s.result) != null)
5457	>	t.result = (((tr = t.result) == null) ? sr :
5458	>	reducer.apply(tr, sr));
5459	>	s = t.rights = s.nextRight;
5460	>	}
5461	>	}
5462	>	}
5463	>	}
5464	>	}
5465	>
5466	>	@SuppressWarnings("serial")
5467	>	static final class MapReduceKeysTask<K,V,U>
5468	>	extends BulkTask<K,V,U> {
5469	>	final Function<? super K, ? extends U> transformer;
5470	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5471	>	U result;
5472	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5473	>	MapReduceKeysTask
5474	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5475	>	MapReduceKeysTask<K,V,U> nextRight,
5476	>	Function<? super K, ? extends U> transformer,
5477	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5478	>	super(p, b, i, f, t); this.nextRight = nextRight;
5479	>	this.transformer = transformer;
5480	>	this.reducer = reducer;
5481	>	}
5482	>	public final U getRawResult() { return result; }
5483	>	public final void compute() {
5484	>	final Function<? super K, ? extends U> transformer;
5485	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5486	>	if ((transformer = this.transformer) != null &&
5487	>	(reducer = this.reducer) != null) {
5488	>	for (int i = baseIndex, f, h; batch > 0 &&
5489	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5490	>	addToPendingCount(1);
5491	>	(rights = new MapReduceKeysTask<K,V,U>
5492	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5493	>	rights, transformer, reducer)).fork();
5494	>	}
5495	>	U r = null;
5496	>	for (Node<K,V> p; (p = advance()) != null; ) {
5497	>	U u;
5498	>	if ((u = transformer.apply(p.key)) != null)
5499	>	r = (r == null) ? u : reducer.apply(r, u);
5500	>	}
5501	>	result = r;
5502	>	CountedCompleter<?> c;
5503	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5504	>	@SuppressWarnings("unchecked")
5505	>	MapReduceKeysTask<K,V,U>
5506	>	t = (MapReduceKeysTask<K,V,U>)c,
5507	>	s = t.rights;
5508	>	while (s != null) {
5509	>	U tr, sr;
5510	>	if ((sr = s.result) != null)
5511	>	t.result = (((tr = t.result) == null) ? sr :
5512	>	reducer.apply(tr, sr));
5513	>	s = t.rights = s.nextRight;
5514	>	}
5515	>	}
5516	>	}
5517	>	}
5518	>	}
5519	>
5520	>	@SuppressWarnings("serial")
5521	>	static final class MapReduceValuesTask<K,V,U>
5522	>	extends BulkTask<K,V,U> {
5523	>	final Function<? super V, ? extends U> transformer;
5524	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5525	>	U result;
5526	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5527	>	MapReduceValuesTask
5528	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5529	>	MapReduceValuesTask<K,V,U> nextRight,
5530	>	Function<? super V, ? extends U> transformer,
5531	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5532	>	super(p, b, i, f, t); this.nextRight = nextRight;
5533	>	this.transformer = transformer;
5534	>	this.reducer = reducer;
5535	>	}
5536	>	public final U getRawResult() { return result; }
5537	>	public final void compute() {
5538	>	final Function<? super V, ? extends U> transformer;
5539	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5540	>	if ((transformer = this.transformer) != null &&
5541	>	(reducer = this.reducer) != null) {
5542	>	for (int i = baseIndex, f, h; batch > 0 &&
5543	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5544	>	addToPendingCount(1);
5545	>	(rights = new MapReduceValuesTask<K,V,U>
5546	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5547	>	rights, transformer, reducer)).fork();
5548	>	}
5549	>	U r = null;
5550	>	for (Node<K,V> p; (p = advance()) != null; ) {
5551	>	U u;
5552	>	if ((u = transformer.apply(p.val)) != null)
5553	>	r = (r == null) ? u : reducer.apply(r, u);
5554	>	}
5555	>	result = r;
5556	>	CountedCompleter<?> c;
5557	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5558	>	@SuppressWarnings("unchecked")
5559	>	MapReduceValuesTask<K,V,U>
5560	>	t = (MapReduceValuesTask<K,V,U>)c,
5561	>	s = t.rights;
5562	>	while (s != null) {
5563	>	U tr, sr;
5564	>	if ((sr = s.result) != null)
5565	>	t.result = (((tr = t.result) == null) ? sr :
5566	>	reducer.apply(tr, sr));
5567	>	s = t.rights = s.nextRight;
5568	>	}
5569	>	}
5570	>	}
5571	>	}
5572	>	}
5573	>
5574	>	@SuppressWarnings("serial")
5575	>	static final class MapReduceEntriesTask<K,V,U>
5576	>	extends BulkTask<K,V,U> {
5577	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5578	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5579	>	U result;
5580	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5581	>	MapReduceEntriesTask
5582	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5583	>	MapReduceEntriesTask<K,V,U> nextRight,
5584	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5585	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5586	>	super(p, b, i, f, t); this.nextRight = nextRight;
5587	>	this.transformer = transformer;
5588	>	this.reducer = reducer;
5589	>	}
5590	>	public final U getRawResult() { return result; }
5591	>	public final void compute() {
5592	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5593	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5594	>	if ((transformer = this.transformer) != null &&
5595	>	(reducer = this.reducer) != null) {
5596	>	for (int i = baseIndex, f, h; batch > 0 &&
5597	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5598	>	addToPendingCount(1);
5599	>	(rights = new MapReduceEntriesTask<K,V,U>
5600	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5601	>	rights, transformer, reducer)).fork();
5602	>	}
5603	>	U r = null;
5604	>	for (Node<K,V> p; (p = advance()) != null; ) {
5605	>	U u;
5606	>	if ((u = transformer.apply(p)) != null)
5607	>	r = (r == null) ? u : reducer.apply(r, u);
5608	>	}
5609	>	result = r;
5610	>	CountedCompleter<?> c;
5611	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5612	>	@SuppressWarnings("unchecked")
5613	>	MapReduceEntriesTask<K,V,U>
5614	>	t = (MapReduceEntriesTask<K,V,U>)c,
5615	>	s = t.rights;
5616	>	while (s != null) {
5617	>	U tr, sr;
5618	>	if ((sr = s.result) != null)
5619	>	t.result = (((tr = t.result) == null) ? sr :
5620	>	reducer.apply(tr, sr));
5621	>	s = t.rights = s.nextRight;
5622	>	}
5623	>	}
5624	>	}
5625	>	}
5626	>	}
5627	>
5628	>	@SuppressWarnings("serial")
5629	>	static final class MapReduceMappingsTask<K,V,U>
5630	>	extends BulkTask<K,V,U> {
5631	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5632	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5633	>	U result;
5634	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5635	>	MapReduceMappingsTask
5636	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5637	>	MapReduceMappingsTask<K,V,U> nextRight,
5638	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5639	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5640	>	super(p, b, i, f, t); this.nextRight = nextRight;
5641	>	this.transformer = transformer;
5642	>	this.reducer = reducer;
5643	>	}
5644	>	public final U getRawResult() { return result; }
5645	>	public final void compute() {
5646	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5647	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5648	>	if ((transformer = this.transformer) != null &&
5649	>	(reducer = this.reducer) != null) {
5650	>	for (int i = baseIndex, f, h; batch > 0 &&
5651	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5652	>	addToPendingCount(1);
5653	>	(rights = new MapReduceMappingsTask<K,V,U>
5654	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5655	>	rights, transformer, reducer)).fork();
5656	>	}
5657	>	U r = null;
5658	>	for (Node<K,V> p; (p = advance()) != null; ) {
5659	>	U u;
5660	>	if ((u = transformer.apply(p.key, p.val)) != null)
5661	>	r = (r == null) ? u : reducer.apply(r, u);
5662	>	}
5663	>	result = r;
5664	>	CountedCompleter<?> c;
5665	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5666	>	@SuppressWarnings("unchecked")
5667	>	MapReduceMappingsTask<K,V,U>
5668	>	t = (MapReduceMappingsTask<K,V,U>)c,
5669	>	s = t.rights;
5670	>	while (s != null) {
5671	>	U tr, sr;
5672	>	if ((sr = s.result) != null)
5673	>	t.result = (((tr = t.result) == null) ? sr :
5674	>	reducer.apply(tr, sr));
5675	>	s = t.rights = s.nextRight;
5676	>	}
5677	>	}
5678	>	}
5679	>	}
5680	>	}
5681	>
5682	>	@SuppressWarnings("serial")
5683	>	static final class MapReduceKeysToDoubleTask<K,V>
5684	>	extends BulkTask<K,V,Double> {
5685	>	final ToDoubleFunction<? super K> transformer;
5686	>	final DoubleBinaryOperator reducer;
5687	>	final double basis;
5688	>	double result;
5689	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5690	>	MapReduceKeysToDoubleTask
5691	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5692	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5693	>	ToDoubleFunction<? super K> transformer,
5694	>	double basis,
5695	>	DoubleBinaryOperator reducer) {
5696	>	super(p, b, i, f, t); this.nextRight = nextRight;
5697	>	this.transformer = transformer;
5698	>	this.basis = basis; this.reducer = reducer;
5699	>	}
5700	>	public final Double getRawResult() { return result; }
5701	>	public final void compute() {
5702	>	final ToDoubleFunction<? super K> transformer;
5703	>	final DoubleBinaryOperator reducer;
5704	>	if ((transformer = this.transformer) != null &&
5705	>	(reducer = this.reducer) != null) {
5706	>	double r = this.basis;
5707	>	for (int i = baseIndex, f, h; batch > 0 &&
5708	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5709	>	addToPendingCount(1);
5710	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5711	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5712	>	rights, transformer, r, reducer)).fork();
5713	>	}
5714	>	for (Node<K,V> p; (p = advance()) != null; )
5715	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5716	>	result = r;
5717	>	CountedCompleter<?> c;
5718	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5719	>	@SuppressWarnings("unchecked")
5720	>	MapReduceKeysToDoubleTask<K,V>
5721	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5722	>	s = t.rights;
5723	>	while (s != null) {
5724	>	t.result = reducer.applyAsDouble(t.result, s.result);
5725	>	s = t.rights = s.nextRight;
5726	>	}
5727	>	}
5728	>	}
5729	>	}
5730	>	}
5731	>
5732	>	@SuppressWarnings("serial")
5733	>	static final class MapReduceValuesToDoubleTask<K,V>
5734	>	extends BulkTask<K,V,Double> {
5735	>	final ToDoubleFunction<? super V> transformer;
5736	>	final DoubleBinaryOperator reducer;
5737	>	final double basis;
5738	>	double result;
5739	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5740	>	MapReduceValuesToDoubleTask
5741	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5742	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5743	>	ToDoubleFunction<? super V> transformer,
5744	>	double basis,
5745	>	DoubleBinaryOperator reducer) {
5746	>	super(p, b, i, f, t); this.nextRight = nextRight;
5747	>	this.transformer = transformer;
5748	>	this.basis = basis; this.reducer = reducer;
5749	>	}
5750	>	public final Double getRawResult() { return result; }
5751	>	public final void compute() {
5752	>	final ToDoubleFunction<? super V> transformer;
5753	>	final DoubleBinaryOperator reducer;
5754	>	if ((transformer = this.transformer) != null &&
5755	>	(reducer = this.reducer) != null) {
5756	>	double r = this.basis;
5757	>	for (int i = baseIndex, f, h; batch > 0 &&
5758	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5759	>	addToPendingCount(1);
5760	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5761	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5762	>	rights, transformer, r, reducer)).fork();
5763	>	}
5764	>	for (Node<K,V> p; (p = advance()) != null; )
5765	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5766	>	result = r;
5767	>	CountedCompleter<?> c;
5768	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5769	>	@SuppressWarnings("unchecked")
5770	>	MapReduceValuesToDoubleTask<K,V>
5771	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5772	>	s = t.rights;
5773	>	while (s != null) {
5774	>	t.result = reducer.applyAsDouble(t.result, s.result);
5775	>	s = t.rights = s.nextRight;
5776	>	}
5777	>	}
5778	>	}
5779	>	}
5780	>	}
5781	>
5782	>	@SuppressWarnings("serial")
5783	>	static final class MapReduceEntriesToDoubleTask<K,V>
5784	>	extends BulkTask<K,V,Double> {
5785	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5786	>	final DoubleBinaryOperator reducer;
5787	>	final double basis;
5788	>	double result;
5789	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5790	>	MapReduceEntriesToDoubleTask
5791	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5792	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5793	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5794	>	double basis,
5795	>	DoubleBinaryOperator reducer) {
5796	>	super(p, b, i, f, t); this.nextRight = nextRight;
5797	>	this.transformer = transformer;
5798	>	this.basis = basis; this.reducer = reducer;
5799	>	}
5800	>	public final Double getRawResult() { return result; }
5801	>	public final void compute() {
5802	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5803	>	final DoubleBinaryOperator reducer;
5804	>	if ((transformer = this.transformer) != null &&
5805	>	(reducer = this.reducer) != null) {
5806	>	double r = this.basis;
5807	>	for (int i = baseIndex, f, h; batch > 0 &&
5808	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5809	>	addToPendingCount(1);
5810	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5811	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5812	>	rights, transformer, r, reducer)).fork();
5813	>	}
5814	>	for (Node<K,V> p; (p = advance()) != null; )
5815	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5816	>	result = r;
5817	>	CountedCompleter<?> c;
5818	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5819	>	@SuppressWarnings("unchecked")
5820	>	MapReduceEntriesToDoubleTask<K,V>
5821	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5822	>	s = t.rights;
5823	>	while (s != null) {
5824	>	t.result = reducer.applyAsDouble(t.result, s.result);
5825	>	s = t.rights = s.nextRight;
5826	>	}
5827	>	}
5828	>	}
5829	>	}
5830	>	}
5831	>
5832	>	@SuppressWarnings("serial")
5833	>	static final class MapReduceMappingsToDoubleTask<K,V>
5834	>	extends BulkTask<K,V,Double> {
5835	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5836	>	final DoubleBinaryOperator reducer;
5837	>	final double basis;
5838	>	double result;
5839	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5840	>	MapReduceMappingsToDoubleTask
5841	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5842	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5843	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5844	>	double basis,
5845	>	DoubleBinaryOperator reducer) {
5846	>	super(p, b, i, f, t); this.nextRight = nextRight;
5847	>	this.transformer = transformer;
5848	>	this.basis = basis; this.reducer = reducer;
5849	>	}
5850	>	public final Double getRawResult() { return result; }
5851	>	public final void compute() {
5852	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5853	>	final DoubleBinaryOperator reducer;
5854	>	if ((transformer = this.transformer) != null &&
5855	>	(reducer = this.reducer) != null) {
5856	>	double r = this.basis;
5857	>	for (int i = baseIndex, f, h; batch > 0 &&
5858	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5859	>	addToPendingCount(1);
5860	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5861	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5862	>	rights, transformer, r, reducer)).fork();
5863	>	}
5864	>	for (Node<K,V> p; (p = advance()) != null; )
5865	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5866	>	result = r;
5867	>	CountedCompleter<?> c;
5868	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5869	>	@SuppressWarnings("unchecked")
5870	>	MapReduceMappingsToDoubleTask<K,V>
5871	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5872	>	s = t.rights;
5873	>	while (s != null) {
5874	>	t.result = reducer.applyAsDouble(t.result, s.result);
5875	>	s = t.rights = s.nextRight;
5876	>	}
5877	>	}
5878	>	}
5879	>	}
5880	>	}
5881	>
5882	>	@SuppressWarnings("serial")
5883	>	static final class MapReduceKeysToLongTask<K,V>
5884	>	extends BulkTask<K,V,Long> {
5885	>	final ToLongFunction<? super K> transformer;
5886	>	final LongBinaryOperator reducer;
5887	>	final long basis;
5888	>	long result;
5889	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5890	>	MapReduceKeysToLongTask
5891	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5892	>	MapReduceKeysToLongTask<K,V> nextRight,
5893	>	ToLongFunction<? super K> transformer,
5894	>	long basis,
5895	>	LongBinaryOperator reducer) {
5896	>	super(p, b, i, f, t); this.nextRight = nextRight;
5897	>	this.transformer = transformer;
5898	>	this.basis = basis; this.reducer = reducer;
5899	>	}
5900	>	public final Long getRawResult() { return result; }
5901	>	public final void compute() {
5902	>	final ToLongFunction<? super K> transformer;
5903	>	final LongBinaryOperator reducer;
5904	>	if ((transformer = this.transformer) != null &&
5905	>	(reducer = this.reducer) != null) {
5906	>	long r = this.basis;
5907	>	for (int i = baseIndex, f, h; batch > 0 &&
5908	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5909	>	addToPendingCount(1);
5910	>	(rights = new MapReduceKeysToLongTask<K,V>
5911	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5912	>	rights, transformer, r, reducer)).fork();
5913	>	}
5914	>	for (Node<K,V> p; (p = advance()) != null; )
5915	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5916	>	result = r;
5917	>	CountedCompleter<?> c;
5918	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5919	>	@SuppressWarnings("unchecked")
5920	>	MapReduceKeysToLongTask<K,V>
5921	>	t = (MapReduceKeysToLongTask<K,V>)c,
5922	>	s = t.rights;
5923	>	while (s != null) {
5924	>	t.result = reducer.applyAsLong(t.result, s.result);
5925	>	s = t.rights = s.nextRight;
5926	>	}
5927	>	}
5928	>	}
5929	>	}
5930	>	}
5931	>
5932	>	@SuppressWarnings("serial")
5933	>	static final class MapReduceValuesToLongTask<K,V>
5934	>	extends BulkTask<K,V,Long> {
5935	>	final ToLongFunction<? super V> transformer;
5936	>	final LongBinaryOperator reducer;
5937	>	final long basis;
5938	>	long result;
5939	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5940	>	MapReduceValuesToLongTask
5941	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5942	>	MapReduceValuesToLongTask<K,V> nextRight,
5943	>	ToLongFunction<? super V> transformer,
5944	>	long basis,
5945	>	LongBinaryOperator reducer) {
5946	>	super(p, b, i, f, t); this.nextRight = nextRight;
5947	>	this.transformer = transformer;
5948	>	this.basis = basis; this.reducer = reducer;
5949	>	}
5950	>	public final Long getRawResult() { return result; }
5951	>	public final void compute() {
5952	>	final ToLongFunction<? super V> transformer;
5953	>	final LongBinaryOperator reducer;
5954	>	if ((transformer = this.transformer) != null &&
5955	>	(reducer = this.reducer) != null) {
5956	>	long r = this.basis;
5957	>	for (int i = baseIndex, f, h; batch > 0 &&
5958	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5959	>	addToPendingCount(1);
5960	>	(rights = new MapReduceValuesToLongTask<K,V>
5961	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5962	>	rights, transformer, r, reducer)).fork();
5963	>	}
5964	>	for (Node<K,V> p; (p = advance()) != null; )
5965	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5966	>	result = r;
5967	>	CountedCompleter<?> c;
5968	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5969	>	@SuppressWarnings("unchecked")
5970	>	MapReduceValuesToLongTask<K,V>
5971	>	t = (MapReduceValuesToLongTask<K,V>)c,
5972	>	s = t.rights;
5973	>	while (s != null) {
5974	>	t.result = reducer.applyAsLong(t.result, s.result);
5975	>	s = t.rights = s.nextRight;
5976	>	}
5977	>	}
5978	>	}
5979	>	}
5980	>	}
5981	>
5982	>	@SuppressWarnings("serial")
5983	>	static final class MapReduceEntriesToLongTask<K,V>
5984	>	extends BulkTask<K,V,Long> {
5985	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5986	>	final LongBinaryOperator reducer;
5987	>	final long basis;
5988	>	long result;
5989	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5990	>	MapReduceEntriesToLongTask
5991	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5992	>	MapReduceEntriesToLongTask<K,V> nextRight,
5993	>	ToLongFunction<Map.Entry<K,V>> transformer,
5994	>	long basis,
5995	>	LongBinaryOperator reducer) {
5996	>	super(p, b, i, f, t); this.nextRight = nextRight;
5997	>	this.transformer = transformer;
5998	>	this.basis = basis; this.reducer = reducer;
5999	>	}
6000	>	public final Long getRawResult() { return result; }
6001	>	public final void compute() {
6002	>	final ToLongFunction<Map.Entry<K,V>> transformer;
6003	>	final LongBinaryOperator reducer;
6004	>	if ((transformer = this.transformer) != null &&
6005	>	(reducer = this.reducer) != null) {
6006	>	long r = this.basis;
6007	>	for (int i = baseIndex, f, h; batch > 0 &&
6008	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6009	>	addToPendingCount(1);
6010	>	(rights = new MapReduceEntriesToLongTask<K,V>
6011	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6012	>	rights, transformer, r, reducer)).fork();
6013	>	}
6014	>	for (Node<K,V> p; (p = advance()) != null; )
6015	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
6016	>	result = r;
6017	>	CountedCompleter<?> c;
6018	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6019	>	@SuppressWarnings("unchecked")
6020	>	MapReduceEntriesToLongTask<K,V>
6021	>	t = (MapReduceEntriesToLongTask<K,V>)c,
6022	>	s = t.rights;
6023	>	while (s != null) {
6024	>	t.result = reducer.applyAsLong(t.result, s.result);
6025	>	s = t.rights = s.nextRight;
6026	>	}
6027	>	}
6028	>	}
6029	>	}
6030	>	}
6031	>
6032	>	@SuppressWarnings("serial")
6033	>	static final class MapReduceMappingsToLongTask<K,V>
6034	>	extends BulkTask<K,V,Long> {
6035	>	final ToLongBiFunction<? super K, ? super V> transformer;
6036	>	final LongBinaryOperator reducer;
6037	>	final long basis;
6038	>	long result;
6039	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6040	>	MapReduceMappingsToLongTask
6041	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6042	>	MapReduceMappingsToLongTask<K,V> nextRight,
6043	>	ToLongBiFunction<? super K, ? super V> transformer,
6044	>	long basis,
6045	>	LongBinaryOperator reducer) {
6046	>	super(p, b, i, f, t); this.nextRight = nextRight;
6047	>	this.transformer = transformer;
6048	>	this.basis = basis; this.reducer = reducer;
6049	>	}
6050	>	public final Long getRawResult() { return result; }
6051	>	public final void compute() {
6052	>	final ToLongBiFunction<? super K, ? super V> transformer;
6053	>	final LongBinaryOperator reducer;
6054	>	if ((transformer = this.transformer) != null &&
6055	>	(reducer = this.reducer) != null) {
6056	>	long r = this.basis;
6057	>	for (int i = baseIndex, f, h; batch > 0 &&
6058	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6059	>	addToPendingCount(1);
6060	>	(rights = new MapReduceMappingsToLongTask<K,V>
6061	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6062	>	rights, transformer, r, reducer)).fork();
6063	>	}
6064	>	for (Node<K,V> p; (p = advance()) != null; )
6065	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6066	>	result = r;
6067	>	CountedCompleter<?> c;
6068	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6069	>	@SuppressWarnings("unchecked")
6070	>	MapReduceMappingsToLongTask<K,V>
6071	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6072	>	s = t.rights;
6073	>	while (s != null) {
6074	>	t.result = reducer.applyAsLong(t.result, s.result);
6075	>	s = t.rights = s.nextRight;
6076	>	}
6077	>	}
6078	>	}
6079	>	}
6080	>	}
6081	>
6082	>	@SuppressWarnings("serial")
6083	>	static final class MapReduceKeysToIntTask<K,V>
6084	>	extends BulkTask<K,V,Integer> {
6085	>	final ToIntFunction<? super K> transformer;
6086	>	final IntBinaryOperator reducer;
6087	>	final int basis;
6088	>	int result;
6089	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6090	>	MapReduceKeysToIntTask
6091	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6092	>	MapReduceKeysToIntTask<K,V> nextRight,
6093	>	ToIntFunction<? super K> transformer,
6094	>	int basis,
6095	>	IntBinaryOperator reducer) {
6096	>	super(p, b, i, f, t); this.nextRight = nextRight;
6097	>	this.transformer = transformer;
6098	>	this.basis = basis; this.reducer = reducer;
6099	>	}
6100	>	public final Integer getRawResult() { return result; }
6101	>	public final void compute() {
6102	>	final ToIntFunction<? super K> transformer;
6103	>	final IntBinaryOperator reducer;
6104	>	if ((transformer = this.transformer) != null &&
6105	>	(reducer = this.reducer) != null) {
6106	>	int r = this.basis;
6107	>	for (int i = baseIndex, f, h; batch > 0 &&
6108	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6109	>	addToPendingCount(1);
6110	>	(rights = new MapReduceKeysToIntTask<K,V>
6111	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6112	>	rights, transformer, r, reducer)).fork();
6113	>	}
6114	>	for (Node<K,V> p; (p = advance()) != null; )
6115	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6116	>	result = r;
6117	>	CountedCompleter<?> c;
6118	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6119	>	@SuppressWarnings("unchecked")
6120	>	MapReduceKeysToIntTask<K,V>
6121	>	t = (MapReduceKeysToIntTask<K,V>)c,
6122	>	s = t.rights;
6123	>	while (s != null) {
6124	>	t.result = reducer.applyAsInt(t.result, s.result);
6125	>	s = t.rights = s.nextRight;
6126	>	}
6127	>	}
6128	>	}
6129	>	}
6130	>	}
6131	>
6132	>	@SuppressWarnings("serial")
6133	>	static final class MapReduceValuesToIntTask<K,V>
6134	>	extends BulkTask<K,V,Integer> {
6135	>	final ToIntFunction<? super V> transformer;
6136	>	final IntBinaryOperator reducer;
6137	>	final int basis;
6138	>	int result;
6139	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6140	>	MapReduceValuesToIntTask
6141	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6142	>	MapReduceValuesToIntTask<K,V> nextRight,
6143	>	ToIntFunction<? super V> transformer,
6144	>	int basis,
6145	>	IntBinaryOperator reducer) {
6146	>	super(p, b, i, f, t); this.nextRight = nextRight;
6147	>	this.transformer = transformer;
6148	>	this.basis = basis; this.reducer = reducer;
6149	>	}
6150	>	public final Integer getRawResult() { return result; }
6151	>	public final void compute() {
6152	>	final ToIntFunction<? super V> transformer;
6153	>	final IntBinaryOperator reducer;
6154	>	if ((transformer = this.transformer) != null &&
6155	>	(reducer = this.reducer) != null) {
6156	>	int r = this.basis;
6157	>	for (int i = baseIndex, f, h; batch > 0 &&
6158	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6159	>	addToPendingCount(1);
6160	>	(rights = new MapReduceValuesToIntTask<K,V>
6161	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6162	>	rights, transformer, r, reducer)).fork();
6163	>	}
6164	>	for (Node<K,V> p; (p = advance()) != null; )
6165	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6166	>	result = r;
6167	>	CountedCompleter<?> c;
6168	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6169	>	@SuppressWarnings("unchecked")
6170	>	MapReduceValuesToIntTask<K,V>
6171	>	t = (MapReduceValuesToIntTask<K,V>)c,
6172	>	s = t.rights;
6173	>	while (s != null) {
6174	>	t.result = reducer.applyAsInt(t.result, s.result);
6175	>	s = t.rights = s.nextRight;
6176	>	}
6177	>	}
6178	>	}
6179	>	}
6180	>	}
6181	>
6182	>	@SuppressWarnings("serial")
6183	>	static final class MapReduceEntriesToIntTask<K,V>
6184	>	extends BulkTask<K,V,Integer> {
6185	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6186	>	final IntBinaryOperator reducer;
6187	>	final int basis;
6188	>	int result;
6189	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6190	>	MapReduceEntriesToIntTask
6191	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6192	>	MapReduceEntriesToIntTask<K,V> nextRight,
6193	>	ToIntFunction<Map.Entry<K,V>> transformer,
6194	>	int basis,
6195	>	IntBinaryOperator reducer) {
6196	>	super(p, b, i, f, t); this.nextRight = nextRight;
6197	>	this.transformer = transformer;
6198	>	this.basis = basis; this.reducer = reducer;
6199	>	}
6200	>	public final Integer getRawResult() { return result; }
6201	>	public final void compute() {
6202	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6203	>	final IntBinaryOperator reducer;
6204	>	if ((transformer = this.transformer) != null &&
6205	>	(reducer = this.reducer) != null) {
6206	>	int r = this.basis;
6207	>	for (int i = baseIndex, f, h; batch > 0 &&
6208	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6209	>	addToPendingCount(1);
6210	>	(rights = new MapReduceEntriesToIntTask<K,V>
6211	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6212	>	rights, transformer, r, reducer)).fork();
6213	>	}
6214	>	for (Node<K,V> p; (p = advance()) != null; )
6215	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6216	>	result = r;
6217	>	CountedCompleter<?> c;
6218	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6219	>	@SuppressWarnings("unchecked")
6220	>	MapReduceEntriesToIntTask<K,V>
6221	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6222	>	s = t.rights;
6223	>	while (s != null) {
6224	>	t.result = reducer.applyAsInt(t.result, s.result);
6225	>	s = t.rights = s.nextRight;
6226	>	}
6227	>	}
6228	>	}
6229	>	}
6230	>	}
6231	>
6232	>	@SuppressWarnings("serial")
6233	>	static final class MapReduceMappingsToIntTask<K,V>
6234	>	extends BulkTask<K,V,Integer> {
6235	>	final ToIntBiFunction<? super K, ? super V> transformer;
6236	>	final IntBinaryOperator reducer;
6237	>	final int basis;
6238	>	int result;
6239	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6240	>	MapReduceMappingsToIntTask
6241	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6242	>	MapReduceMappingsToIntTask<K,V> nextRight,
6243	>	ToIntBiFunction<? super K, ? super V> transformer,
6244	>	int basis,
6245	>	IntBinaryOperator reducer) {
6246	>	super(p, b, i, f, t); this.nextRight = nextRight;
6247	>	this.transformer = transformer;
6248	>	this.basis = basis; this.reducer = reducer;
6249	>	}
6250	>	public final Integer getRawResult() { return result; }
6251	>	public final void compute() {
6252	>	final ToIntBiFunction<? super K, ? super V> transformer;
6253	>	final IntBinaryOperator reducer;
6254	>	if ((transformer = this.transformer) != null &&
6255	>	(reducer = this.reducer) != null) {
6256	>	int r = this.basis;
6257	>	for (int i = baseIndex, f, h; batch > 0 &&
6258	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6259	>	addToPendingCount(1);
6260	>	(rights = new MapReduceMappingsToIntTask<K,V>
6261	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6262	>	rights, transformer, r, reducer)).fork();
6263	>	}
6264	>	for (Node<K,V> p; (p = advance()) != null; )
6265	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6266	>	result = r;
6267	>	CountedCompleter<?> c;
6268	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6269	>	@SuppressWarnings("unchecked")
6270	>	MapReduceMappingsToIntTask<K,V>
6271	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6272	>	s = t.rights;
6273	>	while (s != null) {
6274	>	t.result = reducer.applyAsInt(t.result, s.result);
6275	>	s = t.rights = s.nextRight;
6276	>	}
6277	>	}
6278	>	}
6279		}
6280		}
6281
6282		// Unsafe mechanics
6283	<	private static final sun.misc.Unsafe UNSAFE;
6284	<	private static final long SBASE;
6285	<	private static final int SSHIFT;
6286	<	private static final long TBASE;
6287	<	private static final int TSHIFT;
6283	>	private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
6284	>	private static final long SIZECTL;
6285	>	private static final long TRANSFERINDEX;
6286	>	private static final long BASECOUNT;
6287	>	private static final long CELLSBUSY;
6288	>	private static final long CELLVALUE;
6289	>	private static final int ABASE;
6290	>	private static final int ASHIFT;
6291
6292		static {
1474	–	int ss, ts;
6293		try {
6294	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6295	<	Class tc = HashEntry[].class;
6296	<	Class sc = Segment[].class;
6297	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6298	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6299	<	ts = UNSAFE.arrayIndexScale(tc);
6300	<	ss = UNSAFE.arrayIndexScale(sc);
6301	<	} catch (Exception e) {
6294	>	SIZECTL = U.objectFieldOffset
6295	>	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6296	>	TRANSFERINDEX = U.objectFieldOffset
6297	>	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6298	>	BASECOUNT = U.objectFieldOffset
6299	>	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6300	>	CELLSBUSY = U.objectFieldOffset
6301	>	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6302	>
6303	>	CELLVALUE = U.objectFieldOffset
6304	>	(CounterCell.class.getDeclaredField("value"));
6305	>
6306	>	ABASE = U.arrayBaseOffset(Node[].class);
6307	>	int scale = U.arrayIndexScale(Node[].class);
6308	>	if ((scale & (scale - 1)) != 0)
6309	>	throw new Error("array index scale not a power of two");
6310	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6311	>	} catch (ReflectiveOperationException e) {
6312		throw new Error(e);
6313		}
1486	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1487	–	throw new Error("data type scale not a power of two");
1488	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1489	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
1490	–	}
6314
6315	+	// Reduce the risk of rare disastrous classloading in first call to
6316	+	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6317	+	Class<?> ensureLoaded = LockSupport.class;
6318	+	}
6319		}

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