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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.112 by jsr166, Fri Jun 3 02:28:05 2011 UTC vs.
Revision 1.237 by jsr166, Thu Jul 18 17:13:42 2013 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.Comparator;
17	>	import java.util.ConcurrentModificationException;
18	>	import java.util.Enumeration;
19	>	import java.util.HashMap;
20	>	import java.util.Hashtable;
21	>	import java.util.Iterator;
22	>	import java.util.Map;
23	>	import java.util.NoSuchElementException;
24	>	import java.util.Set;
25	>	import java.util.Spliterator;
26	>	import java.util.concurrent.ConcurrentMap;
27	>	import java.util.concurrent.ForkJoinPool;
28	>	import java.util.concurrent.atomic.AtomicReference;
29	>	import java.util.concurrent.locks.LockSupport;
30	>	import java.util.concurrent.locks.ReentrantLock;
31	>	import java.util.function.BiConsumer;
32	>	import java.util.function.BiFunction;
33	>	import java.util.function.BinaryOperator;
34	>	import java.util.function.Consumer;
35	>	import java.util.function.DoubleBinaryOperator;
36	>	import java.util.function.Function;
37	>	import java.util.function.IntBinaryOperator;
38	>	import java.util.function.LongBinaryOperator;
39	>	import java.util.function.ToDoubleBiFunction;
40	>	import java.util.function.ToDoubleFunction;
41	>	import java.util.function.ToIntBiFunction;
42	>	import java.util.function.ToIntFunction;
43	>	import java.util.function.ToLongBiFunction;
44	>	import java.util.function.ToLongFunction;
45	>	import java.util.stream.Stream;
46
47		/**
48		* A hash table supporting full concurrency of retrievals and
49	<	* adjustable expected concurrency for updates. This class obeys the
49	>	* high expected concurrency for updates. This class obeys the
50		* same functional specification as {@link java.util.Hashtable}, and
51		* includes versions of methods corresponding to each method of
52	<	* <tt>Hashtable</tt>. However, even though all operations are
52	>	* {@code Hashtable}. However, even though all operations are
53		* thread-safe, retrieval operations do <em>not</em> entail locking,
54		* and there is <em>not</em> any support for locking the entire table
55		* in a way that prevents all access.  This class is fully
56	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
56	>	* interoperable with {@code Hashtable} in programs that rely on its
57		* thread safety but not on its synchronization details.
58		*
59	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
60	<	* block, so may overlap with update operations (including
61	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
62	<	* of the most recently <em>completed</em> update operations holding
63	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
64	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
65	<	* removal of only some entries.  Similarly, Iterators and
66	<	* Enumerations return elements reflecting the state of the hash table
67	<	* at some point at or since the creation of the iterator/enumeration.
68	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
69	<	* However, iterators are designed to be used by only one thread at a time.
70	<	*
71	<	* <p> The allowed concurrency among update operations is guided by
72	<	* the optional <tt>concurrencyLevel</tt> constructor argument
73	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
74	<	* table is internally partitioned to try to permit the indicated
75	<	* number of concurrent updates without contention. Because placement
76	<	* in hash tables is essentially random, the actual concurrency will
77	<	* vary.  Ideally, you should choose a value to accommodate as many
78	<	* threads as will ever concurrently modify the table. Using a
79	<	* significantly higher value than you need can waste space and time,
80	<	* and a significantly lower value can lead to thread contention. But
81	<	* overestimates and underestimates within an order of magnitude do
82	<	* not usually have much noticeable impact. A value of one is
83	<	* appropriate when it is known that only one thread will modify and
84	<	* all others will only read. Also, resizing this or any other kind of
85	<	* hash table is a relatively slow operation, so, when possible, it is
86	<	* a good idea to provide estimates of expected table sizes in
87	<	* constructors.
59	>	* <p>Retrieval operations (including {@code get}) generally do not
60	>	* block, so may overlap with update operations (including {@code put}
61	>	* and {@code remove}). Retrievals reflect the results of the most
62	>	* recently <em>completed</em> update operations holding upon their
63	>	* onset. (More formally, an update operation for a given key bears a
64	>	* <em>happens-before</em> relation with any (non-null) retrieval for
65	>	* that key reporting the updated value.)  For aggregate operations
66	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
67	>	* reflect insertion or removal of only some entries.  Similarly,
68	>	* Iterators and Enumerations return elements reflecting the state of
69	>	* the hash table at some point at or since the creation of the
70	>	* iterator/enumeration.  They do <em>not</em> throw {@link
71	>	* ConcurrentModificationException}.  However, iterators are designed
72	>	* to be used by only one thread at a time.  Bear in mind that the
73	>	* results of aggregate status methods including {@code size}, {@code
74	>	* isEmpty}, and {@code containsValue} are typically useful only when
75	>	* a map is not undergoing concurrent updates in other threads.
76	>	* Otherwise the results of these methods reflect transient states
77	>	* that may be adequate for monitoring or estimation purposes, but not
78	>	* for program control.
79	>	*
80	>	* <p>The table is dynamically expanded when there are too many
81	>	* collisions (i.e., keys that have distinct hash codes but fall into
82	>	* the same slot modulo the table size), with the expected average
83	>	* effect of maintaining roughly two bins per mapping (corresponding
84	>	* to a 0.75 load factor threshold for resizing). There may be much
85	>	* variance around this average as mappings are added and removed, but
86	>	* overall, this maintains a commonly accepted time/space tradeoff for
87	>	* hash tables.  However, resizing this or any other kind of hash
88	>	* table may be a relatively slow operation. When possible, it is a
89	>	* good idea to provide a size estimate as an optional {@code
90	>	* initialCapacity} constructor argument. An additional optional
91	>	* {@code loadFactor} constructor argument provides a further means of
92	>	* customizing initial table capacity by specifying the table density
93	>	* to be used in calculating the amount of space to allocate for the
94	>	* given number of elements.  Also, for compatibility with previous
95	>	* versions of this class, constructors may optionally specify an
96	>	* expected {@code concurrencyLevel} as an additional hint for
97	>	* internal sizing.  Note that using many keys with exactly the same
98	>	* {@code hashCode()} is a sure way to slow down performance of any
99	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
100	>	* this class may use comparison order among keys to help break ties.
101	>	*
102	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
103	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
104	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
105	>	* mapped values are (perhaps transiently) not used or all take the
106	>	* same mapping value.
107	>	*
108	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
109	>	* form of histogram or multiset) by using {@link
110	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
111	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
112	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
113	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
114		*
115		* <p>This class and its views and iterators implement all of the
116		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
117		* interfaces.
118		*
119	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
120	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
119	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
120	>	* does <em>not</em> allow {@code null} to be used as a key or value.
121	>	*
122	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
123	>	* operations that, unlike most {@link Stream} methods, are designed
124	>	* to be safely, and often sensibly, applied even with maps that are
125	>	* being concurrently updated by other threads; for example, when
126	>	* computing a snapshot summary of the values in a shared registry.
127	>	* There are three kinds of operation, each with four forms, accepting
128	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
129	>	* and/or return values. Because the elements of a ConcurrentHashMap
130	>	* are not ordered in any particular way, and may be processed in
131	>	* different orders in different parallel executions, the correctness
132	>	* of supplied functions should not depend on any ordering, or on any
133	>	* other objects or values that may transiently change while
134	>	* computation is in progress; and except for forEach actions, should
135	>	* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
136	>	* objects do not support method {@code setValue}.
137	>	*
138	>	* <ul>
139	>	* <li> forEach: Perform a given action on each element.
140	>	* A variant form applies a given transformation on each element
141	>	* before performing the action.</li>
142	>	*
143	>	* <li> search: Return the first available non-null result of
144	>	* applying a given function on each element; skipping further
145	>	* search when a result is found.</li>
146	>	*
147	>	* <li> reduce: Accumulate each element.  The supplied reduction
148	>	* function cannot rely on ordering (more formally, it should be
149	>	* both associative and commutative).  There are five variants:
150	>	*
151	>	* <ul>
152	>	*
153	>	* <li> Plain reductions. (There is not a form of this method for
154	>	* (key, value) function arguments since there is no corresponding
155	>	* return type.)</li>
156	>	*
157	>	* <li> Mapped reductions that accumulate the results of a given
158	>	* function applied to each element.</li>
159	>	*
160	>	* <li> Reductions to scalar doubles, longs, and ints, using a
161	>	* given basis value.</li>
162	>	*
163	>	* </ul>
164	>	* </li>
165	>	* </ul>
166	>	*
167	>	* <p>These bulk operations accept a {@code parallelismThreshold}
168	>	* argument. Methods proceed sequentially if the current map size is
169	>	* estimated to be less than the given threshold. Using a value of
170	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
171	>	* of {@code 1} results in maximal parallelism by partitioning into
172	>	* enough subtasks to fully utilize the {@link
173	>	* ForkJoinPool#commonPool()} that is used for all parallel
174	>	* computations. Normally, you would initially choose one of these
175	>	* extreme values, and then measure performance of using in-between
176	>	* values that trade off overhead versus throughput.
177	>	*
178	>	* <p>The concurrency properties of bulk operations follow
179	>	* from those of ConcurrentHashMap: Any non-null result returned
180	>	* from {@code get(key)} and related access methods bears a
181	>	* happens-before relation with the associated insertion or
182	>	* update.  The result of any bulk operation reflects the
183	>	* composition of these per-element relations (but is not
184	>	* necessarily atomic with respect to the map as a whole unless it
185	>	* is somehow known to be quiescent).  Conversely, because keys
186	>	* and values in the map are never null, null serves as a reliable
187	>	* atomic indicator of the current lack of any result.  To
188	>	* maintain this property, null serves as an implicit basis for
189	>	* all non-scalar reduction operations. For the double, long, and
190	>	* int versions, the basis should be one that, when combined with
191	>	* any other value, returns that other value (more formally, it
192	>	* should be the identity element for the reduction). Most common
193	>	* reductions have these properties; for example, computing a sum
194	>	* with basis 0 or a minimum with basis MAX_VALUE.
195	>	*
196	>	* <p>Search and transformation functions provided as arguments
197	>	* should similarly return null to indicate the lack of any result
198	>	* (in which case it is not used). In the case of mapped
199	>	* reductions, this also enables transformations to serve as
200	>	* filters, returning null (or, in the case of primitive
201	>	* specializations, the identity basis) if the element should not
202	>	* be combined. You can create compound transformations and
203	>	* filterings by composing them yourself under this "null means
204	>	* there is nothing there now" rule before using them in search or
205	>	* reduce operations.
206	>	*
207	>	* <p>Methods accepting and/or returning Entry arguments maintain
208	>	* key-value associations. They may be useful for example when
209	>	* finding the key for the greatest value. Note that "plain" Entry
210	>	* arguments can be supplied using {@code new
211	>	* AbstractMap.SimpleEntry(k,v)}.
212	>	*
213	>	* <p>Bulk operations may complete abruptly, throwing an
214	>	* exception encountered in the application of a supplied
215	>	* function. Bear in mind when handling such exceptions that other
216	>	* concurrently executing functions could also have thrown
217	>	* exceptions, or would have done so if the first exception had
218	>	* not occurred.
219	>	*
220	>	* <p>Speedups for parallel compared to sequential forms are common
221	>	* but not guaranteed.  Parallel operations involving brief functions
222	>	* on small maps may execute more slowly than sequential forms if the
223	>	* underlying work to parallelize the computation is more expensive
224	>	* than the computation itself.  Similarly, parallelization may not
225	>	* lead to much actual parallelism if all processors are busy
226	>	* performing unrelated tasks.
227	>	*
228	>	* <p>All arguments to all task methods must be non-null.
229		*
230		* <p>This class is a member of the
231		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 236 | import java.io.ObjectOutputStream;
236		* @param <K> the type of keys maintained by this map
237		* @param <V> the type of mapped values
238		*/
239	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
74	<	implements ConcurrentMap<K, V>, Serializable {
239	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V> implements ConcurrentMap<K,V>, Serializable {
240		private static final long serialVersionUID = 7249069246763182397L;
241
242		/*
243	<	* The basic strategy is to subdivide the table among Segments,
244	<	* each of which itself is a concurrently readable hash table.  To
245	<	* reduce footprint, all but one segments are constructed only
246	<	* when first needed (see ensureSegment). To maintain visibility
247	<	* in the presence of lazy construction, accesses to segments as
248	<	* well as elements of segment's table must use volatile access,
249	<	* which is done via Unsafe within methods segmentAt etc
250	<	* below. These provide the functionality of AtomicReferenceArrays
251	<	* but reduce the levels of indirection. Additionally,
252	<	* volatile-writes of table elements and entry "next" fields
253	<	* within locked operations use the cheaper "lazySet" forms of
254	<	* writes (via putOrderedObject) because these writes are always
255	<	* followed by lock releases that maintain sequential consistency
256	<	* of table updates.
257	<	*
258	<	* Historical note: The previous version of this class relied
259	<	* heavily on "final" fields, which avoided some volatile reads at
260	<	* the expense of a large initial footprint.  Some remnants of
261	<	* that design (including forced construction of segment 0) exist
262	<	* to ensure serialization compatibility.
243	>	* Overview:
244	>	*
245	>	* The primary design goal of this hash table is to maintain
246	>	* concurrent readability (typically method get(), but also
247	>	* iterators and related methods) while minimizing update
248	>	* contention. Secondary goals are to keep space consumption about
249	>	* the same or better than java.util.HashMap, and to support high
250	>	* initial insertion rates on an empty table by many threads.
251	>	*
252	>	* This map usually acts as a binned (bucketed) hash table.  Each
253	>	* key-value mapping is held in a Node.  Most nodes are instances
254	>	* of the basic Node class with hash, key, value, and next
255	>	* fields. However, various subclasses exist: TreeNodes are
256	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
257	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
258	>	* of bins during resizing. ReservationNodes are used as
259	>	* placeholders while establishing values in computeIfAbsent and
260	>	* related methods.  The types TreeBin, ForwardingNode, and
261	>	* ReservationNode do not hold normal user keys, values, or
262	>	* hashes, and are readily distinguishable during search etc
263	>	* because they have negative hash fields and null key and value
264	>	* fields. (These special nodes are either uncommon or transient,
265	>	* so the impact of carrying around some unused fields is
266	>	* insignificant.)
267	>	*
268	>	* The table is lazily initialized to a power-of-two size upon the
269	>	* first insertion.  Each bin in the table normally contains a
270	>	* list of Nodes (most often, the list has only zero or one Node).
271	>	* Table accesses require volatile/atomic reads, writes, and
272	>	* CASes.  Because there is no other way to arrange this without
273	>	* adding further indirections, we use intrinsics
274	>	* (sun.misc.Unsafe) operations.
275	>	*
276	>	* We use the top (sign) bit of Node hash fields for control
277	>	* purposes -- it is available anyway because of addressing
278	>	* constraints.  Nodes with negative hash fields are specially
279	>	* handled or ignored in map methods.
280	>	*
281	>	* Insertion (via put or its variants) of the first node in an
282	>	* empty bin is performed by just CASing it to the bin.  This is
283	>	* by far the most common case for put operations under most
284	>	* key/hash distributions.  Other update operations (insert,
285	>	* delete, and replace) require locks.  We do not want to waste
286	>	* the space required to associate a distinct lock object with
287	>	* each bin, so instead use the first node of a bin list itself as
288	>	* a lock. Locking support for these locks relies on builtin
289	>	* "synchronized" monitors.
290	>	*
291	>	* Using the first node of a list as a lock does not by itself
292	>	* suffice though: When a node is locked, any update must first
293	>	* validate that it is still the first node after locking it, and
294	>	* retry if not. Because new nodes are always appended to lists,
295	>	* once a node is first in a bin, it remains first until deleted
296	>	* or the bin becomes invalidated (upon resizing).
297	>	*
298	>	* The main disadvantage of per-bin locks is that other update
299	>	* operations on other nodes in a bin list protected by the same
300	>	* lock can stall, for example when user equals() or mapping
301	>	* functions take a long time.  However, statistically, under
302	>	* random hash codes, this is not a common problem.  Ideally, the
303	>	* frequency of nodes in bins follows a Poisson distribution
304	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
305	>	* parameter of about 0.5 on average, given the resizing threshold
306	>	* of 0.75, although with a large variance because of resizing
307	>	* granularity. Ignoring variance, the expected occurrences of
308	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
309	>	* first values are:
310	>	*
311	>	* 0:    0.60653066
312	>	* 1:    0.30326533
313	>	* 2:    0.07581633
314	>	* 3:    0.01263606
315	>	* 4:    0.00157952
316	>	* 5:    0.00015795
317	>	* 6:    0.00001316
318	>	* 7:    0.00000094
319	>	* 8:    0.00000006
320	>	* more: less than 1 in ten million
321	>	*
322	>	* Lock contention probability for two threads accessing distinct
323	>	* elements is roughly 1 / (8 * #elements) under random hashes.
324	>	*
325	>	* Actual hash code distributions encountered in practice
326	>	* sometimes deviate significantly from uniform randomness.  This
327	>	* includes the case when N > (1<<30), so some keys MUST collide.
328	>	* Similarly for dumb or hostile usages in which multiple keys are
329	>	* designed to have identical hash codes or ones that differs only
330	>	* in masked-out high bits. So we use a secondary strategy that
331	>	* applies when the number of nodes in a bin exceeds a
332	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
333	>	* specialized form of red-black trees), bounding search time to
334	>	* O(log N).  Each search step in a TreeBin is at least twice as
335	>	* slow as in a regular list, but given that N cannot exceed
336	>	* (1<<64) (before running out of addresses) this bounds search
337	>	* steps, lock hold times, etc, to reasonable constants (roughly
338	>	* 100 nodes inspected per operation worst case) so long as keys
339	>	* are Comparable (which is very common -- String, Long, etc).
340	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
341	>	* traversal pointers as regular nodes, so can be traversed in
342	>	* iterators in the same way.
343	>	*
344	>	* The table is resized when occupancy exceeds a percentage
345	>	* threshold (nominally, 0.75, but see below).  Any thread
346	>	* noticing an overfull bin may assist in resizing after the
347	>	* initiating thread allocates and sets up the replacement
348	>	* array. However, rather than stalling, these other threads may
349	>	* proceed with insertions etc.  The use of TreeBins shields us
350	>	* from the worst case effects of overfilling while resizes are in
351	>	* progress.  Resizing proceeds by transferring bins, one by one,
352	>	* from the table to the next table. To enable concurrency, the
353	>	* next table must be (incrementally) prefilled with place-holders
354	>	* serving as reverse forwarders to the old table.  Because we are
355	>	* using power-of-two expansion, the elements from each bin must
356	>	* either stay at same index, or move with a power of two
357	>	* offset. We eliminate unnecessary node creation by catching
358	>	* cases where old nodes can be reused because their next fields
359	>	* won't change.  On average, only about one-sixth of them need
360	>	* cloning when a table doubles. The nodes they replace will be
361	>	* garbage collectable as soon as they are no longer referenced by
362	>	* any reader thread that may be in the midst of concurrently
363	>	* traversing table.  Upon transfer, the old table bin contains
364	>	* only a special forwarding node (with hash field "MOVED") that
365	>	* contains the next table as its key. On encountering a
366	>	* forwarding node, access and update operations restart, using
367	>	* the new table.
368	>	*
369	>	* Each bin transfer requires its bin lock, which can stall
370	>	* waiting for locks while resizing. However, because other
371	>	* threads can join in and help resize rather than contend for
372	>	* locks, average aggregate waits become shorter as resizing
373	>	* progresses.  The transfer operation must also ensure that all
374	>	* accessible bins in both the old and new table are usable by any
375	>	* traversal.  This is arranged by proceeding from the last bin
376	>	* (table.length - 1) up towards the first.  Upon seeing a
377	>	* forwarding node, traversals (see class Traverser) arrange to
378	>	* move to the new table without revisiting nodes.  However, to
379	>	* ensure that no intervening nodes are skipped, bin splitting can
380	>	* only begin after the associated reverse-forwarders are in
381	>	* place.
382	>	*
383	>	* The traversal scheme also applies to partial traversals of
384	>	* ranges of bins (via an alternate Traverser constructor)
385	>	* to support partitioned aggregate operations.  Also, read-only
386	>	* operations give up if ever forwarded to a null table, which
387	>	* provides support for shutdown-style clearing, which is also not
388	>	* currently implemented.
389	>	*
390	>	* Lazy table initialization minimizes footprint until first use,
391	>	* and also avoids resizings when the first operation is from a
392	>	* putAll, constructor with map argument, or deserialization.
393	>	* These cases attempt to override the initial capacity settings,
394	>	* but harmlessly fail to take effect in cases of races.
395	>	*
396	>	* The element count is maintained using a specialization of
397	>	* LongAdder. We need to incorporate a specialization rather than
398	>	* just use a LongAdder in order to access implicit
399	>	* contention-sensing that leads to creation of multiple
400	>	* CounterCells.  The counter mechanics avoid contention on
401	>	* updates but can encounter cache thrashing if read too
402	>	* frequently during concurrent access. To avoid reading so often,
403	>	* resizing under contention is attempted only upon adding to a
404	>	* bin already holding two or more nodes. Under uniform hash
405	>	* distributions, the probability of this occurring at threshold
406	>	* is around 13%, meaning that only about 1 in 8 puts check
407	>	* threshold (and after resizing, many fewer do so).
408	>	*
409	>	* TreeBins use a special form of comparison for search and
410	>	* related operations (which is the main reason we cannot use
411	>	* existing collections such as TreeMaps). TreeBins contain
412	>	* Comparable elements, but may contain others, as well as
413	>	* elements that are Comparable but not necessarily Comparable
414	>	* for the same T, so we cannot invoke compareTo among them. To
415	>	* handle this, the tree is ordered primarily by hash value, then
416	>	* by Comparable.compareTo order if applicable.  On lookup at a
417	>	* node, if elements are not comparable or compare as 0 then both
418	>	* left and right children may need to be searched in the case of
419	>	* tied hash values. (This corresponds to the full list search
420	>	* that would be necessary if all elements were non-Comparable and
421	>	* had tied hashes.)  The red-black balancing code is updated from
422	>	* pre-jdk-collections
423	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
424	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
425	>	* Algorithms" (CLR).
426	>	*
427	>	* TreeBins also require an additional locking mechanism.  While
428	>	* list traversal is always possible by readers even during
429	>	* updates, tree traversal is not, mainly because of tree-rotations
430	>	* that may change the root node and/or its linkages.  TreeBins
431	>	* include a simple read-write lock mechanism parasitic on the
432	>	* main bin-synchronization strategy: Structural adjustments
433	>	* associated with an insertion or removal are already bin-locked
434	>	* (and so cannot conflict with other writers) but must wait for
435	>	* ongoing readers to finish. Since there can be only one such
436	>	* waiter, we use a simple scheme using a single "waiter" field to
437	>	* block writers.  However, readers need never block.  If the root
438	>	* lock is held, they proceed along the slow traversal path (via
439	>	* next-pointers) until the lock becomes available or the list is
440	>	* exhausted, whichever comes first. These cases are not fast, but
441	>	* maximize aggregate expected throughput.
442	>	*
443	>	* Maintaining API and serialization compatibility with previous
444	>	* versions of this class introduces several oddities. Mainly: We
445	>	* leave untouched but unused constructor arguments refering to
446	>	* concurrencyLevel. We accept a loadFactor constructor argument,
447	>	* but apply it only to initial table capacity (which is the only
448	>	* time that we can guarantee to honor it.) We also declare an
449	>	* unused "Segment" class that is instantiated in minimal form
450	>	* only when serializing.
451	>	*
452	>	* This file is organized to make things a little easier to follow
453	>	* while reading than they might otherwise: First the main static
454	>	* declarations and utilities, then fields, then main public
455	>	* methods (with a few factorings of multiple public methods into
456	>	* internal ones), then sizing methods, trees, traversers, and
457	>	* bulk operations.
458		*/
459
460		/* ---------------- Constants -------------- */
461
462		/**
463	<	* The default initial capacity for this table,
464	<	* used when not otherwise specified in a constructor.
463	>	* The largest possible table capacity.  This value must be
464	>	* exactly 1<<30 to stay within Java array allocation and indexing
465	>	* bounds for power of two table sizes, and is further required
466	>	* because the top two bits of 32bit hash fields are used for
467	>	* control purposes.
468		*/
469	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
469	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
470
471		/**
472	<	* The default load factor for this table, used when not
473	<	* otherwise specified in a constructor.
472	>	* The default initial table capacity.  Must be a power of 2
473	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
474		*/
475	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
475	>	private static final int DEFAULT_CAPACITY = 16;
476
477		/**
478	<	* The default concurrency level for this table, used when not
479	<	* otherwise specified in a constructor.
478	>	* The largest possible (non-power of two) array size.
479	>	* Needed by toArray and related methods.
480		*/
481	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
481	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
482
483		/**
484	<	* The maximum capacity, used if a higher value is implicitly
485	<	* 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.
484	>	* The default concurrency level for this table. Unused but
485	>	* defined for compatibility with previous versions of this class.
486		*/
487	<	static final int MAXIMUM_CAPACITY = 1 << 30;
487	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
488
489		/**
490	<	* The minimum capacity for per-segment tables.  Must be a power
491	<	* of two, at least two to avoid immediate resizing on next use
492	<	* after lazy construction.
490	>	* The load factor for this table. Overrides of this value in
491	>	* constructors affect only the initial table capacity.  The
492	>	* actual floating point value isn't normally used -- it is
493	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
494	>	* the associated resizing threshold.
495		*/
496	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
496	>	private static final float LOAD_FACTOR = 0.75f;
497
498		/**
499	<	* The maximum number of segments to allow; used to bound
500	<	* constructor arguments. Must be power of two less than 1 << 24.
499	>	* The bin count threshold for using a tree rather than list for a
500	>	* bin.  Bins are converted to trees when adding an element to a
501	>	* bin with at least this many nodes. The value must be greater
502	>	* than 2, and should be at least 8 to mesh with assumptions in
503	>	* tree removal about conversion back to plain bins upon
504	>	* shrinkage.
505		*/
506	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
506	>	static final int TREEIFY_THRESHOLD = 8;
507
508		/**
509	<	* Number of unsynchronized retries in size and containsValue
510	<	* methods before resorting to locking. This is used to avoid
511	<	* unbounded retries if tables undergo continuous modification
145	<	* which would make it impossible to obtain an accurate result.
509	>	* The bin count threshold for untreeifying a (split) bin during a
510	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
511	>	* most 6 to mesh with shrinkage detection under removal.
512		*/
513	<	static final int RETRIES_BEFORE_LOCK = 2;
148	<
149	<	/* ---------------- Fields -------------- */
513	>	static final int UNTREEIFY_THRESHOLD = 6;
514
515		/**
516	<	* Mask value for indexing into segments. The upper bits of a
517	<	* key's hash code are used to choose the segment.
516	>	* The smallest table capacity for which bins may be treeified.
517	>	* (Otherwise the table is resized if too many nodes in a bin.)
518	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
519	>	* conflicts between resizing and treeification thresholds.
520		*/
521	<	final int segmentMask;
521	>	static final int MIN_TREEIFY_CAPACITY = 64;
522
523		/**
524	<	* Shift value for indexing within segments.
524	>	* Minimum number of rebinnings per transfer step. Ranges are
525	>	* subdivided to allow multiple resizer threads.  This value
526	>	* serves as a lower bound to avoid resizers encountering
527	>	* excessive memory contention.  The value should be at least
528	>	* DEFAULT_CAPACITY.
529		*/
530	<	final int segmentShift;
530	>	private static final int MIN_TRANSFER_STRIDE = 16;
531
532	<	/**
533	<	* The segments, each of which is a specialized hash table.
532	>	/*
533	>	* Encodings for Node hash fields. See above for explanation.
534		*/
535	<	final Segment<K,V>[] segments;
536	<
537	<	transient Set<K> keySet;
538	<	transient Set<Map.Entry<K,V>> entrySet;
539	<	transient Collection<V> values;
540	<
541	<	/**
542	<	* ConcurrentHashMap list entry. Note that this is never exported
543	<	* out as a user-visible Map.Entry.
535	>	static final int MOVED     = -1; // hash for forwarding nodes
536	>	static final int TREEBIN   = -2; // hash for roots of trees
537	>	static final int RESERVED  = -3; // hash for transient reservations
538	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
539	>
540	>	/** Number of CPUS, to place bounds on some sizings */
541	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
542	>
543	>	/** For serialization compatibility. */
544	>	private static final ObjectStreamField[] serialPersistentFields = {
545	>	new ObjectStreamField("segments", Segment[].class),
546	>	new ObjectStreamField("segmentMask", Integer.TYPE),
547	>	new ObjectStreamField("segmentShift", Integer.TYPE)
548	>	};
549	>
550	>	/* ---------------- Nodes -------------- */
551	>
552	>	/**
553	>	* Key-value entry.  This class is never exported out as a
554	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
555	>	* MapEntry below), but can be used for read-only traversals used
556	>	* in bulk tasks.  Subclasses of Node with a negative hash field
557	>	* are special, and contain null keys and values (but are never
558	>	* exported).  Otherwise, keys and vals are never null.
559		*/
560	<	static final class HashEntry<K,V> {
560	>	static class Node<K,V> implements Map.Entry<K,V> {
561		final int hash;
562		final K key;
563	<	volatile V value;
564	<	volatile HashEntry<K,V> next;
563	>	volatile V val;
564	>	volatile Node<K,V> next;
565
566	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
566	>	Node(int hash, K key, V val, Node<K,V> next) {
567		this.hash = hash;
568		this.key = key;
569	<	this.value = value;
569	>	this.val = val;
570		this.next = next;
571		}
572
573	+	public final K getKey()       { return key; }
574	+	public final V getValue()     { return val; }
575	+	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
576	+	public final String toString(){ return key + "=" + val; }
577	+	public final V setValue(V value) {
578	+	throw new UnsupportedOperationException();
579	+	}
580	+
581	+	public final boolean equals(Object o) {
582	+	Object k, v, u; Map.Entry<?,?> e;
583	+	return ((o instanceof Map.Entry) &&
584	+	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
585	+	(v = e.getValue()) != null &&
586	+	(k == key || k.equals(key)) &&
587	+	(v == (u = val) || v.equals(u)));
588	+	}
589	+
590		/**
591	<	* Sets next field with volatile write semantics.  (See above
190	<	* about use of putOrderedObject.)
591	>	* Virtualized support for map.get(); overridden in subclasses.
592		*/
593	<	final void setNext(HashEntry<K,V> n) {
594	<	UNSAFE.putOrderedObject(this, nextOffset, n);
593	>	Node<K,V> find(int h, Object k) {
594	>	Node<K,V> e = this;
595	>	if (k != null) {
596	>	do {
597	>	K ek;
598	>	if (e.hash == h &&
599	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
600	>	return e;
601	>	} while ((e = e.next) != null);
602	>	}
603	>	return null;
604		}
605	+	}
606
607	<	// Unsafe mechanics
608	<	static final sun.misc.Unsafe UNSAFE;
609	<	static final long nextOffset;
610	<	static {
611	<	try {
612	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
613	<	Class<?> k = HashEntry.class;
614	<	nextOffset = UNSAFE.objectFieldOffset
615	<	(k.getDeclaredField("next"));
616	<	} catch (Exception e) {
617	<	throw new Error(e);
607	>	/* ---------------- Static utilities -------------- */
608	>
609	>	/**
610	>	* Spreads (XORs) higher bits of hash to lower and also forces top
611	>	* bit to 0. Because the table uses power-of-two masking, sets of
612	>	* hashes that vary only in bits above the current mask will
613	>	* always collide. (Among known examples are sets of Float keys
614	>	* holding consecutive whole numbers in small tables.)  So we
615	>	* apply a transform that spreads the impact of higher bits
616	>	* downward. There is a tradeoff between speed, utility, and
617	>	* quality of bit-spreading. Because many common sets of hashes
618	>	* are already reasonably distributed (so don't benefit from
619	>	* spreading), and because we use trees to handle large sets of
620	>	* collisions in bins, we just XOR some shifted bits in the
621	>	* cheapest possible way to reduce systematic lossage, as well as
622	>	* to incorporate impact of the highest bits that would otherwise
623	>	* never be used in index calculations because of table bounds.
624	>	*/
625	>	static final int spread(int h) {
626	>	return (h ^ (h >>> 16)) & HASH_BITS;
627	>	}
628	>
629	>	/**
630	>	* Returns a power of two table size for the given desired capacity.
631	>	* See Hackers Delight, sec 3.2
632	>	*/
633	>	private static final int tableSizeFor(int c) {
634	>	int n = c - 1;
635	>	n |= n >>> 1;
636	>	n |= n >>> 2;
637	>	n |= n >>> 4;
638	>	n |= n >>> 8;
639	>	n |= n >>> 16;
640	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
641	>	}
642	>
643	>	/**
644	>	* Returns x's Class if it is of the form "class C implements
645	>	* Comparable<C>", else null.
646	>	*/
647	>	static Class<?> comparableClassFor(Object x) {
648	>	if (x instanceof Comparable) {
649	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
650	>	if ((c = x.getClass()) == String.class) // bypass checks
651	>	return c;
652	>	if ((ts = c.getGenericInterfaces()) != null) {
653	>	for (int i = 0; i < ts.length; ++i) {
654	>	if (((t = ts[i]) instanceof ParameterizedType) &&
655	>	((p = (ParameterizedType)t).getRawType() ==
656	>	Comparable.class) &&
657	>	(as = p.getActualTypeArguments()) != null &&
658	>	as.length == 1 && as[0] == c) // type arg is c
659	>	return c;
660	>	}
661		}
662		}
663	+	return null;
664		}
665
666		/**
667	<	* Gets the ith element of given table (if nonnull) with volatile
668	<	* read semantics. Note: This is manually integrated into a few
669	<	* performance-sensitive methods to reduce call overhead.
667	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
668	>	* class), else 0.
669	>	*/
670	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
671	>	static int compareComparables(Class<?> kc, Object k, Object x) {
672	>	return (x == null || x.getClass() != kc ? 0 :
673	>	((Comparable)k).compareTo(x));
674	>	}
675	>
676	>	/* ---------------- Table element access -------------- */
677	>
678	>	/*
679	>	* Volatile access methods are used for table elements as well as
680	>	* elements of in-progress next table while resizing.  All uses of
681	>	* the tab arguments must be null checked by callers.  All callers
682	>	* also paranoically precheck that tab's length is not zero (or an
683	>	* equivalent check), thus ensuring that any index argument taking
684	>	* the form of a hash value anded with (length - 1) is a valid
685	>	* index.  Note that, to be correct wrt arbitrary concurrency
686	>	* errors by users, these checks must operate on local variables,
687	>	* which accounts for some odd-looking inline assignments below.
688	>	* Note that calls to setTabAt always occur within locked regions,
689	>	* and so in principle require only release ordering, not need
690	>	* full volatile semantics, but are currently coded as volatile
691	>	* writes to be conservative.
692		*/
693	+
694		@SuppressWarnings("unchecked")
695	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
696	<	return (tab == null) ? null :
697	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
698	<	(tab, ((long)i << TSHIFT) + TBASE);
695	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
696	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
697	>	}
698	>
699	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
700	>	Node<K,V> c, Node<K,V> v) {
701	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
702	>	}
703	>
704	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
705	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
706		}
707
708	+	/* ---------------- Fields -------------- */
709	+
710	+	/**
711	+	* The array of bins. Lazily initialized upon first insertion.
712	+	* Size is always a power of two. Accessed directly by iterators.
713	+	*/
714	+	transient volatile Node<K,V>[] table;
715	+
716		/**
717	<	* Sets the ith element of given table, with volatile write
225	<	* semantics. (See above about use of putOrderedObject.)
717	>	* The next table to use; non-null only while resizing.
718		*/
719	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
720	<	HashEntry<K,V> e) {
721	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
719	>	private transient volatile Node<K,V>[] nextTable;
720	>
721	>	/**
722	>	* Base counter value, used mainly when there is no contention,
723	>	* but also as a fallback during table initialization
724	>	* races. Updated via CAS.
725	>	*/
726	>	private transient volatile long baseCount;
727	>
728	>	/**
729	>	* Table initialization and resizing control.  When negative, the
730	>	* table is being initialized or resized: -1 for initialization,
731	>	* else -(1 + the number of active resizing threads).  Otherwise,
732	>	* when table is null, holds the initial table size to use upon
733	>	* creation, or 0 for default. After initialization, holds the
734	>	* next element count value upon which to resize the table.
735	>	*/
736	>	private transient volatile int sizeCtl;
737	>
738	>	/**
739	>	* The next table index (plus one) to split while resizing.
740	>	*/
741	>	private transient volatile int transferIndex;
742	>
743	>	/**
744	>	* The least available table index to split while resizing.
745	>	*/
746	>	private transient volatile int transferOrigin;
747	>
748	>	/**
749	>	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
750	>	*/
751	>	private transient volatile int cellsBusy;
752	>
753	>	/**
754	>	* Table of counter cells. When non-null, size is a power of 2.
755	>	*/
756	>	private transient volatile CounterCell[] counterCells;
757	>
758	>	// views
759	>	private transient KeySetView<K,V> keySet;
760	>	private transient ValuesView<K,V> values;
761	>	private transient EntrySetView<K,V> entrySet;
762	>
763	>
764	>	/* ---------------- Public operations -------------- */
765	>
766	>	/**
767	>	* Creates a new, empty map with the default initial table size (16).
768	>	*/
769	>	public ConcurrentHashMap() {
770		}
771
772		/**
773	<	* Applies a supplemental hash function to a given hashCode, which
774	<	* defends against poor quality hash functions.  This is critical
775	<	* because ConcurrentHashMap uses power-of-two length hash tables,
776	<	* that otherwise encounter collisions for hashCodes that do not
777	<	* differ in lower or upper bits.
773	>	* Creates a new, empty map with an initial table size
774	>	* accommodating the specified number of elements without the need
775	>	* to dynamically resize.
776	>	*
777	>	* @param initialCapacity The implementation performs internal
778	>	* sizing to accommodate this many elements.
779	>	* @throws IllegalArgumentException if the initial capacity of
780	>	* elements is negative
781		*/
782	<	private static int hash(int h) {
783	<	// Spread bits to regularize both segment and index locations,
784	<	// using variant of single-word Wang/Jenkins hash.
785	<	h += (h <<  15) ^ 0xffffcd7d;
786	<	h ^= (h >>> 10);
787	<	h += (h <<   3);
788	<	h ^= (h >>>  6);
246	<	h += (h <<   2) + (h << 14);
247	<	return h ^ (h >>> 16);
782	>	public ConcurrentHashMap(int initialCapacity) {
783	>	if (initialCapacity < 0)
784	>	throw new IllegalArgumentException();
785	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
786	>	MAXIMUM_CAPACITY :
787	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
788	>	this.sizeCtl = cap;
789		}
790
791		/**
792	<	* Segments are specialized versions of hash tables.  This
793	<	* subclasses from ReentrantLock opportunistically, just to
794	<	* simplify some locking and avoid separate construction.
792	>	* Creates a new map with the same mappings as the given map.
793	>	*
794	>	* @param m the map
795		*/
796	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
797	<	/*
798	<	* Segments maintain a table of entry lists that are always
799	<	* 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	<	*/
796	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
797	>	this.sizeCtl = DEFAULT_CAPACITY;
798	>	putAll(m);
799	>	}
800
801	<	private static final long serialVersionUID = 2249069246763182397L;
801	>	/**
802	>	* Creates a new, empty map with an initial table size based on
803	>	* the given number of elements ({@code initialCapacity}) and
804	>	* initial table density ({@code loadFactor}).
805	>	*
806	>	* @param initialCapacity the initial capacity. The implementation
807	>	* performs internal sizing to accommodate this many elements,
808	>	* given the specified load factor.
809	>	* @param loadFactor the load factor (table density) for
810	>	* establishing the initial table size
811	>	* @throws IllegalArgumentException if the initial capacity of
812	>	* elements is negative or the load factor is nonpositive
813	>	*
814	>	* @since 1.6
815	>	*/
816	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
817	>	this(initialCapacity, loadFactor, 1);
818	>	}
819
820	<	/**
821	<	* The maximum number of times to tryLock in a prescan before
822	<	* possibly blocking on acquire in preparation for a locked
823	<	* segment operation. On multiprocessors, using a bounded
824	<	* number of retries maintains cache acquired while locating
825	<	* nodes.
826	<	*/
827	<	static final int MAX_SCAN_RETRIES =
828	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
820	>	/**
821	>	* Creates a new, empty map with an initial table size based on
822	>	* the given number of elements ({@code initialCapacity}), table
823	>	* density ({@code loadFactor}), and number of concurrently
824	>	* updating threads ({@code concurrencyLevel}).
825	>	*
826	>	* @param initialCapacity the initial capacity. The implementation
827	>	* performs internal sizing to accommodate this many elements,
828	>	* given the specified load factor.
829	>	* @param loadFactor the load factor (table density) for
830	>	* establishing the initial table size
831	>	* @param concurrencyLevel the estimated number of concurrently
832	>	* updating threads. The implementation may use this value as
833	>	* a sizing hint.
834	>	* @throws IllegalArgumentException if the initial capacity is
835	>	* negative or the load factor or concurrencyLevel are
836	>	* nonpositive
837	>	*/
838	>	public ConcurrentHashMap(int initialCapacity,
839	>	float loadFactor, int concurrencyLevel) {
840	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
841	>	throw new IllegalArgumentException();
842	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
843	>	initialCapacity = concurrencyLevel;   // as estimated threads
844	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
845	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
846	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
847	>	this.sizeCtl = cap;
848	>	}
849
850	<	/**
295	<	* The per-segment table. Elements are accessed via
296	<	* entryAt/setEntryAt providing volatile semantics.
297	<	*/
298	<	transient volatile HashEntry<K,V>[] table;
850	>	// Original (since JDK1.2) Map methods
851
852	<	/**
853	<	* The number of elements. Accessed only either within locks
854	<	* or among other volatile reads that maintain visibility.
855	<	*/
856	<	transient int count;
852	>	/**
853	>	* {@inheritDoc}
854	>	*/
855	>	public int size() {
856	>	long n = sumCount();
857	>	return ((n < 0L) ? 0 :
858	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
859	>	(int)n);
860	>	}
861
862	<	/**
863	<	* The total number of mutative operations in this segment.
864	<	* Even though this may overflows 32 bits, it provides
865	<	* sufficient accuracy for stability checks in CHM isEmpty()
866	<	* and size() methods.  Accessed only either within locks or
867	<	* among other volatile reads that maintain visibility.
312	<	*/
313	<	transient int modCount;
862	>	/**
863	>	* {@inheritDoc}
864	>	*/
865	>	public boolean isEmpty() {
866	>	return sumCount() <= 0L; // ignore transient negative values
867	>	}
868
869	<	/**
870	<	* The table is rehashed when its size exceeds this threshold.
871	<	* (The value of this field is always <tt>(int)(capacity *
872	<	* loadFactor)</tt>.)
873	<	*/
874	<	transient int threshold;
869	>	/**
870	>	* Returns the value to which the specified key is mapped,
871	>	* or {@code null} if this map contains no mapping for the key.
872	>	*
873	>	* <p>More formally, if this map contains a mapping from a key
874	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
875	>	* then this method returns {@code v}; otherwise it returns
876	>	* {@code null}.  (There can be at most one such mapping.)
877	>	*
878	>	* @throws NullPointerException if the specified key is null
879	>	*/
880	>	public V get(Object key) {
881	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
882	>	int h = spread(key.hashCode());
883	>	if ((tab = table) != null && (n = tab.length) > 0 &&
884	>	(e = tabAt(tab, (n - 1) & h)) != null) {
885	>	if ((eh = e.hash) == h) {
886	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
887	>	return e.val;
888	>	}
889	>	else if (eh < 0)
890	>	return (p = e.find(h, key)) != null ? p.val : null;
891	>	while ((e = e.next) != null) {
892	>	if (e.hash == h &&
893	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
894	>	return e.val;
895	>	}
896	>	}
897	>	return null;
898	>	}
899
900	<	/**
901	<	* The load factor for the hash table.  Even though this value
902	<	* is same for all segments, it is replicated to avoid needing
903	<	* links to outer object.
904	<	* @serial
905	<	*/
906	<	final float loadFactor;
900	>	/**
901	>	* Tests if the specified object is a key in this table.
902	>	*
903	>	* @param  key possible key
904	>	* @return {@code true} if and only if the specified object
905	>	*         is a key in this table, as determined by the
906	>	*         {@code equals} method; {@code false} otherwise
907	>	* @throws NullPointerException if the specified key is null
908	>	*/
909	>	public boolean containsKey(Object key) {
910	>	return get(key) != null;
911	>	}
912
913	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
914	<	this.loadFactor = lf;
915	<	this.threshold = threshold;
916	<	this.table = tab;
913	>	/**
914	>	* Returns {@code true} if this map maps one or more keys to the
915	>	* specified value. Note: This method may require a full traversal
916	>	* of the map, and is much slower than method {@code containsKey}.
917	>	*
918	>	* @param value value whose presence in this map is to be tested
919	>	* @return {@code true} if this map maps one or more keys to the
920	>	*         specified value
921	>	* @throws NullPointerException if the specified value is null
922	>	*/
923	>	public boolean containsValue(Object value) {
924	>	if (value == null)
925	>	throw new NullPointerException();
926	>	Node<K,V>[] t;
927	>	if ((t = table) != null) {
928	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
929	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
930	>	V v;
931	>	if ((v = p.val) == value || (v != null && value.equals(v)))
932	>	return true;
933	>	}
934		}
935	+	return false;
936	+	}
937
938	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
939	<	HashEntry<K,V> node = tryLock() ? null :
940	<	scanAndLockForPut(key, hash, value);
941	<	V oldValue;
942	<	try {
943	<	HashEntry<K,V>[] tab = table;
944	<	int index = (tab.length - 1) & hash;
945	<	HashEntry<K,V> first = entryAt(tab, index);
946	<	for (HashEntry<K,V> e = first;;) {
947	<	if (e != null) {
948	<	K k;
949	<	if ((k = e.key) == key ||
950	<	(e.hash == hash && key.equals(k))) {
951	<	oldValue = e.value;
952	<	if (!onlyIfAbsent) {
953	<	e.value = value;
954	<	++modCount;
938	>	/**
939	>	* Maps the specified key to the specified value in this table.
940	>	* Neither the key nor the value can be null.
941	>	*
942	>	* <p>The value can be retrieved by calling the {@code get} method
943	>	* with a key that is equal to the original key.
944	>	*
945	>	* @param key key with which the specified value is to be associated
946	>	* @param value value to be associated with the specified key
947	>	* @return the previous value associated with {@code key}, or
948	>	*         {@code null} if there was no mapping for {@code key}
949	>	* @throws NullPointerException if the specified key or value is null
950	>	*/
951	>	public V put(K key, V value) {
952	>	return putVal(key, value, false);
953	>	}
954	>
955	>	/** Implementation for put and putIfAbsent */
956	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
957	>	if (key == null || value == null) throw new NullPointerException();
958	>	int hash = spread(key.hashCode());
959	>	int binCount = 0;
960	>	for (Node<K,V>[] tab = table;;) {
961	>	Node<K,V> f; int n, i, fh;
962	>	if (tab == null || (n = tab.length) == 0)
963	>	tab = initTable();
964	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
965	>	if (casTabAt(tab, i, null,
966	>	new Node<K,V>(hash, key, value, null)))
967	>	break;                   // no lock when adding to empty bin
968	>	}
969	>	else if ((fh = f.hash) == MOVED)
970	>	tab = helpTransfer(tab, f);
971	>	else {
972	>	V oldVal = null;
973	>	synchronized (f) {
974	>	if (tabAt(tab, i) == f) {
975	>	if (fh >= 0) {
976	>	binCount = 1;
977	>	for (Node<K,V> e = f;; ++binCount) {
978	>	K ek;
979	>	if (e.hash == hash &&
980	>	((ek = e.key) == key ||
981	>	(ek != null && key.equals(ek)))) {
982	>	oldVal = e.val;
983	>	if (!onlyIfAbsent)
984	>	e.val = value;
985	>	break;
986	>	}
987	>	Node<K,V> pred = e;
988	>	if ((e = e.next) == null) {
989	>	pred.next = new Node<K,V>(hash, key,
990	>	value, null);
991	>	break;
992	>	}
993	>	}
994	>	}
995	>	else if (f instanceof TreeBin) {
996	>	Node<K,V> p;
997	>	binCount = 2;
998	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
999	>	value)) != null) {
1000	>	oldVal = p.val;
1001	>	if (!onlyIfAbsent)
1002	>	p.val = value;
1003		}
354	–	break;
1004		}
356	–	e = e.next;
357	–	}
358	–	else {
359	–	if (node != null)
360	–	node.setNext(first);
361	–	else
362	–	node = new HashEntry<K,V>(hash, key, value, first);
363	–	int c = count + 1;
364	–	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
365	–	rehash(node);
366	–	else
367	–	setEntryAt(tab, index, node);
368	–	++modCount;
369	–	count = c;
370	–	oldValue = null;
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;
1005		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
1006		}
1007	<	else if (++retries > MAX_SCAN_RETRIES) {
1008	<	lock();
1007	>	if (binCount != 0) {
1008	>	if (binCount >= TREEIFY_THRESHOLD)
1009	>	treeifyBin(tab, i);
1010	>	if (oldVal != null)
1011	>	return oldVal;
1012		break;
1013		}
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;
506	–	}
507	–	else if (++retries > MAX_SCAN_RETRIES) {
508	–	lock();
509	–	break;
510	–	}
511	–	else if ((retries & 1) == 0 &&
512	–	(f = entryForHash(this, hash)) != first) {
513	–	e = first = f;
514	–	retries = -1;
515	–	}
1014		}
1015		}
1016	+	addCount(1L, binCount);
1017	+	return null;
1018	+	}
1019
1020	<	/**
1021	<	* Remove; match on key only if value null, else match both.
1022	<	*/
1023	<	final V remove(Object key, int hash, Object value) {
1024	<	if (!tryLock())
1025	<	scanAndLock(key, hash);
1026	<	V oldValue = null;
1027	<	try {
1028	<	HashEntry<K,V>[] tab = table;
1029	<	int index = (tab.length - 1) & hash;
1030	<	HashEntry<K,V> e = entryAt(tab, index);
1031	<	HashEntry<K,V> pred = null;
1032	<	while (e != null) {
1033	<	K k;
1034	<	HashEntry<K,V> next = e.next;
1035	<	if ((k = e.key) == key ||
1036	<	(e.hash == hash && key.equals(k))) {
1037	<	V v = e.value;
1038	<	if (value == null || value == v || value.equals(v)) {
1039	<	if (pred == null)
1040	<	setEntryAt(tab, index, next);
1041	<	else
1042	<	pred.setNext(next);
1043	<	++modCount;
1044	<	--count;
1045	<	oldValue = v;
1020	>	/**
1021	>	* Copies all of the mappings from the specified map to this one.
1022	>	* These mappings replace any mappings that this map had for any of the
1023	>	* keys currently in the specified map.
1024	>	*
1025	>	* @param m mappings to be stored in this map
1026	>	*/
1027	>	public void putAll(Map<? extends K, ? extends V> m) {
1028	>	tryPresize(m.size());
1029	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1030	>	putVal(e.getKey(), e.getValue(), false);
1031	>	}
1032	>
1033	>	/**
1034	>	* Removes the key (and its corresponding value) from this map.
1035	>	* This method does nothing if the key is not in the map.
1036	>	*
1037	>	* @param  key the key that needs to be removed
1038	>	* @return the previous value associated with {@code key}, or
1039	>	*         {@code null} if there was no mapping for {@code key}
1040	>	* @throws NullPointerException if the specified key is null
1041	>	*/
1042	>	public V remove(Object key) {
1043	>	return replaceNode(key, null, null);
1044	>	}
1045	>
1046	>	/**
1047	>	* Implementation for the four public remove/replace methods:
1048	>	* Replaces node value with v, conditional upon match of cv if
1049	>	* non-null.  If resulting value is null, delete.
1050	>	*/
1051	>	final V replaceNode(Object key, V value, Object cv) {
1052	>	int hash = spread(key.hashCode());
1053	>	for (Node<K,V>[] tab = table;;) {
1054	>	Node<K,V> f; int n, i, fh;
1055	>	if (tab == null || (n = tab.length) == 0 ||
1056	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1057	>	break;
1058	>	else if ((fh = f.hash) == MOVED)
1059	>	tab = helpTransfer(tab, f);
1060	>	else {
1061	>	V oldVal = null;
1062	>	boolean validated = false;
1063	>	synchronized (f) {
1064	>	if (tabAt(tab, i) == f) {
1065	>	if (fh >= 0) {
1066	>	validated = true;
1067	>	for (Node<K,V> e = f, pred = null;;) {
1068	>	K ek;
1069	>	if (e.hash == hash &&
1070	>	((ek = e.key) == key ||
1071	>	(ek != null && key.equals(ek)))) {
1072	>	V ev = e.val;
1073	>	if (cv == null || cv == ev ||
1074	>	(ev != null && cv.equals(ev))) {
1075	>	oldVal = ev;
1076	>	if (value != null)
1077	>	e.val = value;
1078	>	else if (pred != null)
1079	>	pred.next = e.next;
1080	>	else
1081	>	setTabAt(tab, i, e.next);
1082	>	}
1083	>	break;
1084	>	}
1085	>	pred = e;
1086	>	if ((e = e.next) == null)
1087	>	break;
1088	>	}
1089	>	}
1090	>	else if (f instanceof TreeBin) {
1091	>	validated = true;
1092	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1093	>	TreeNode<K,V> r, p;
1094	>	if ((r = t.root) != null &&
1095	>	(p = r.findTreeNode(hash, key, null)) != null) {
1096	>	V pv = p.val;
1097	>	if (cv == null || cv == pv ||
1098	>	(pv != null && cv.equals(pv))) {
1099	>	oldVal = pv;
1100	>	if (value != null)
1101	>	p.val = value;
1102	>	else if (t.removeTreeNode(p))
1103	>	setTabAt(tab, i, untreeify(t.first));
1104	>	}
1105	>	}
1106		}
546	–	break;
1107		}
548	–	pred = e;
549	–	e = next;
1108		}
1109	<	} finally {
1110	<	unlock();
1111	<	}
1112	<	return oldValue;
1113	<	}
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;
1109	>	if (validated) {
1110	>	if (oldVal != null) {
1111	>	if (value == null)
1112	>	addCount(-1L, -1);
1113	>	return oldVal;
1114		}
1115	+	break;
1116		}
575	–	} finally {
576	–	unlock();
1117		}
578	–	return replaced;
1118		}
1119	+	return null;
1120	+	}
1121
1122	<	final V replace(K key, int hash, V value) {
1123	<	if (!tryLock())
1124	<	scanAndLock(key, hash);
1125	<	V oldValue = null;
1126	<	try {
1127	<	HashEntry<K,V> e;
1128	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1129	<	K k;
1130	<	if ((k = e.key) == key ||
1131	<	(e.hash == hash && key.equals(k))) {
1132	<	oldValue = e.value;
1133	<	e.value = value;
1134	<	++modCount;
1135	<	break;
1122	>	/**
1123	>	* Removes all of the mappings from this map.
1124	>	*/
1125	>	public void clear() {
1126	>	long delta = 0L; // negative number of deletions
1127	>	int i = 0;
1128	>	Node<K,V>[] tab = table;
1129	>	while (tab != null && i < tab.length) {
1130	>	int fh;
1131	>	Node<K,V> f = tabAt(tab, i);
1132	>	if (f == null)
1133	>	++i;
1134	>	else if ((fh = f.hash) == MOVED) {
1135	>	tab = helpTransfer(tab, f);
1136	>	i = 0; // restart
1137	>	}
1138	>	else {
1139	>	synchronized (f) {
1140	>	if (tabAt(tab, i) == f) {
1141	>	Node<K,V> p = (fh >= 0 ? f :
1142	>	(f instanceof TreeBin) ?
1143	>	((TreeBin<K,V>)f).first : null);
1144	>	while (p != null) {
1145	>	--delta;
1146	>	p = p.next;
1147	>	}
1148	>	setTabAt(tab, i++, null);
1149		}
1150		}
597	–	} finally {
598	–	unlock();
1151		}
600	–	return oldValue;
1152		}
1153	+	if (delta != 0L)
1154	+	addCount(delta, -1);
1155	+	}
1156
1157	<	final void clear() {
1158	<	lock();
1159	<	try {
1160	<	HashEntry<K,V>[] tab = table;
1161	<	for (int i = 0; i < tab.length ; i++)
1162	<	setEntryAt(tab, i, null);
1163	<	++modCount;
1164	<	count = 0;
1165	<	} finally {
1166	<	unlock();
1167	<	}
1168	<	}
1157	>	/**
1158	>	* Returns a {@link Set} view of the keys contained in this map.
1159	>	* The set is backed by the map, so changes to the map are
1160	>	* reflected in the set, and vice-versa. The set supports element
1161	>	* removal, which removes the corresponding mapping from this map,
1162	>	* via the {@code Iterator.remove}, {@code Set.remove},
1163	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1164	>	* operations.  It does not support the {@code add} or
1165	>	* {@code addAll} operations.
1166	>	*
1167	>	* <p>The view's {@code iterator} 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.
1172	>	*
1173	>	* @return the set view
1174	>	*/
1175	>	public KeySetView<K,V> keySet() {
1176	>	KeySetView<K,V> ks;
1177	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1178	>	}
1179	>
1180	>	/**
1181	>	* Returns a {@link Collection} view of the values contained in this map.
1182	>	* The collection is backed by the map, so changes to the map are
1183	>	* reflected in the collection, and vice-versa.  The collection
1184	>	* supports element removal, which removes the corresponding
1185	>	* mapping from this map, via the {@code Iterator.remove},
1186	>	* {@code Collection.remove}, {@code removeAll},
1187	>	* {@code retainAll}, and {@code clear} operations.  It does not
1188	>	* support the {@code add} or {@code addAll} operations.
1189	>	*
1190	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1191	>	* that will never throw {@link ConcurrentModificationException},
1192	>	* and guarantees to traverse elements as they existed upon
1193	>	* construction of the iterator, and may (but is not guaranteed to)
1194	>	* reflect any modifications subsequent to construction.
1195	>	*
1196	>	* @return the collection view
1197	>	*/
1198	>	public Collection<V> values() {
1199	>	ValuesView<K,V> vs;
1200	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1201		}
1202
1203	<	// Accessing segments
1203	>	/**
1204	>	* Returns a {@link Set} view of the mappings contained in this map.
1205	>	* The set is backed by the map, so changes to the map are
1206	>	* reflected in the set, and vice-versa.  The set supports element
1207	>	* removal, which removes the corresponding mapping from the map,
1208	>	* via the {@code Iterator.remove}, {@code Set.remove},
1209	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1210	>	* operations.
1211	>	*
1212	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1213	>	* that will never throw {@link ConcurrentModificationException},
1214	>	* and guarantees to traverse elements as they existed upon
1215	>	* construction of the iterator, and may (but is not guaranteed to)
1216	>	* reflect any modifications subsequent to construction.
1217	>	*
1218	>	* @return the set view
1219	>	*/
1220	>	public Set<Map.Entry<K,V>> entrySet() {
1221	>	EntrySetView<K,V> es;
1222	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1223	>	}
1224
1225		/**
1226	<	* Gets the jth element of given segment array (if nonnull) with
1227	<	* volatile element access semantics via Unsafe. (The null check
1228	<	* can trigger harmlessly only during deserialization.) Note:
1229	<	* because each element of segments array is set only once (using
1230	<	* fully ordered writes), some performance-sensitive methods rely
625	<	* on this method only as a recheck upon null reads.
1226	>	* Returns the hash code value for this {@link Map}, i.e.,
1227	>	* the sum of, for each key-value pair in the map,
1228	>	* {@code key.hashCode() ^ value.hashCode()}.
1229	>	*
1230	>	* @return the hash code value for this map
1231		*/
1232	<	@SuppressWarnings("unchecked")
1233	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1234	<	long u = (j << SSHIFT) + SBASE;
1235	<	return ss == null ? null :
1236	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1232	>	public int hashCode() {
1233	>	int h = 0;
1234	>	Node<K,V>[] t;
1235	>	if ((t = table) != null) {
1236	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1237	>	for (Node<K,V> p; (p = it.advance()) != null; )
1238	>	h += p.key.hashCode() ^ p.val.hashCode();
1239	>	}
1240	>	return h;
1241		}
1242
1243		/**
1244	<	* Returns the segment for the given index, creating it and
1245	<	* recording in segment table (via CAS) if not already present.
1244	>	* Returns a string representation of this map.  The string
1245	>	* representation consists of a list of key-value mappings (in no
1246	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1247	>	* mappings are separated by the characters {@code ", "} (comma
1248	>	* and space).  Each key-value mapping is rendered as the key
1249	>	* followed by an equals sign ("{@code =}") followed by the
1250	>	* associated value.
1251		*
1252	<	* @param k the index
639	<	* @return the segment
1252	>	* @return a string representation of this map
1253		*/
1254	<	@SuppressWarnings("unchecked")
1255	<	private Segment<K,V> ensureSegment(int k) {
1256	<	final Segment<K,V>[] ss = this.segments;
1257	<	long u = (k << SSHIFT) + SBASE; // raw offset
1258	<	Segment<K,V> seg;
1259	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1260	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1261	<	int cap = proto.table.length;
1262	<	float lf = proto.loadFactor;
1263	<	int threshold = (int)(cap * lf);
1264	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry<?,?>[cap];
1265	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1266	<	== null) { // recheck
1267	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1268	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1269	<	== null) {
1270	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
658	<	break;
659	<	}
1254	>	public String toString() {
1255	>	Node<K,V>[] t;
1256	>	int f = (t = table) == null ? 0 : t.length;
1257	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1258	>	StringBuilder sb = new StringBuilder();
1259	>	sb.append('{');
1260	>	Node<K,V> p;
1261	>	if ((p = it.advance()) != null) {
1262	>	for (;;) {
1263	>	K k = p.key;
1264	>	V v = p.val;
1265	>	sb.append(k == this ? "(this Map)" : k);
1266	>	sb.append('=');
1267	>	sb.append(v == this ? "(this Map)" : v);
1268	>	if ((p = it.advance()) == null)
1269	>	break;
1270	>	sb.append(',').append(' ');
1271		}
1272		}
1273	<	return seg;
1273	>	return sb.append('}').toString();
1274		}
1275
665	–	// Hash-based segment and entry accesses
666	–
1276		/**
1277	<	* Gets the segment for the given hash code.
1277	>	* Compares the specified object with this map for equality.
1278	>	* Returns {@code true} if the given object is a map with the same
1279	>	* mappings as this map.  This operation may return misleading
1280	>	* results if either map is concurrently modified during execution
1281	>	* of this method.
1282	>	*
1283	>	* @param o object to be compared for equality with this map
1284	>	* @return {@code true} if the specified object is equal to this map
1285		*/
1286	<	@SuppressWarnings("unchecked")
1287	<	private Segment<K,V> segmentForHash(int h) {
1288	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1289	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1286	>	public boolean equals(Object o) {
1287	>	if (o != this) {
1288	>	if (!(o instanceof Map))
1289	>	return false;
1290	>	Map<?,?> m = (Map<?,?>) o;
1291	>	Node<K,V>[] t;
1292	>	int f = (t = table) == null ? 0 : t.length;
1293	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1294	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1295	>	V val = p.val;
1296	>	Object v = m.get(p.key);
1297	>	if (v == null || (v != val && !v.equals(val)))
1298	>	return false;
1299	>	}
1300	>	for (Map.Entry<?,?> e : m.entrySet()) {
1301	>	Object mk, mv, v;
1302	>	if ((mk = e.getKey()) == null ||
1303	>	(mv = e.getValue()) == null ||
1304	>	(v = get(mk)) == null ||
1305	>	(mv != v && !mv.equals(v)))
1306	>	return false;
1307	>	}
1308	>	}
1309	>	return true;
1310		}
1311
1312		/**
1313	<	* Gets the table entry for the given segment and hash code.
1313	>	* Stripped-down version of helper class used in previous version,
1314	>	* declared for the sake of serialization compatibility
1315		*/
1316	<	@SuppressWarnings("unchecked")
1317	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1318	<	HashEntry<K,V>[] tab;
1319	<	return (seg == null || (tab = seg.table) == null) ? null :
683	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
684	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1316	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1317	>	private static final long serialVersionUID = 2249069246763182397L;
1318	>	final float loadFactor;
1319	>	Segment(float lf) { this.loadFactor = lf; }
1320		}
1321
687	–	/* ---------------- Public operations -------------- */
688	–
1322		/**
1323	<	* Creates a new, empty map with the specified initial
1324	<	* capacity, load factor and concurrency level.
1325	<	*
1326	<	* @param initialCapacity the initial capacity. The implementation
1327	<	* performs internal sizing to accommodate this many elements.
1328	<	* @param loadFactor  the load factor threshold, used to control resizing.
1329	<	* Resizing may be performed when the average number of elements per
697	<	* 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.
1323	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1324	>	* stream (i.e., serializes it).
1325	>	* @param s the stream
1326	>	* @serialData
1327	>	* the key (Object) and value (Object)
1328	>	* for each key-value mapping, followed by a null pair.
1329	>	* The key-value mappings are emitted in no particular order.
1330		*/
1331	<	@SuppressWarnings("unchecked")
1332	<	public ConcurrentHashMap(int initialCapacity,
1333	<	float loadFactor, int concurrencyLevel) {
1334	<	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
1331	>	private void writeObject(java.io.ObjectOutputStream s)
1332	>	throws java.io.IOException {
1333	>	// For serialization compatibility
1334	>	// Emulate segment calculation from previous version of this class
1335		int sshift = 0;
1336		int ssize = 1;
1337	<	while (ssize < concurrencyLevel) {
1337	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1338		++sshift;
1339		ssize <<= 1;
1340		}
1341	<	this.segmentShift = 32 - sshift;
1342	<	this.segmentMask = ssize - 1;
1343	<	if (initialCapacity > MAXIMUM_CAPACITY)
1344	<	initialCapacity = MAXIMUM_CAPACITY;
1345	<	int c = initialCapacity / ssize;
1346	<	if (c * ssize < initialCapacity)
1347	<	++c;
1348	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1349	<	while (cap < c)
1350	<	cap <<= 1;
1351	<	// create segments and segments[0]
1352	<	Segment<K,V> s0 =
1353	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1354	<	(HashEntry<K,V>[])new HashEntry<?,?>[cap]);
1355	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment<?,?>[ssize];
1356	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1357	<	this.segments = ss;
1341	>	int segmentShift = 32 - sshift;
1342	>	int segmentMask = ssize - 1;
1343	>	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1344	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1345	>	for (int i = 0; i < segments.length; ++i)
1346	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1347	>	s.putFields().put("segments", segments);
1348	>	s.putFields().put("segmentShift", segmentShift);
1349	>	s.putFields().put("segmentMask", segmentMask);
1350	>	s.writeFields();
1351	>
1352	>	Node<K,V>[] t;
1353	>	if ((t = table) != null) {
1354	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1355	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1356	>	s.writeObject(p.key);
1357	>	s.writeObject(p.val);
1358	>	}
1359	>	}
1360	>	s.writeObject(null);
1361	>	s.writeObject(null);
1362	>	segments = null; // throw away
1363		}
1364
1365		/**
1366	<	* Creates a new, empty map with the specified initial capacity
1367	<	* and load factor and with the default concurrencyLevel (16).
1368	<	*
1369	<	* @param initialCapacity The implementation performs internal
1370	<	* sizing to accommodate this many elements.
1371	<	* @param loadFactor  the load factor threshold, used to control resizing.
1372	<	* Resizing may be performed when the average number of elements per
1373	<	* bin exceeds this threshold.
1374	<	* @throws IllegalArgumentException if the initial capacity of
1375	<	* elements is negative or the load factor is nonpositive
1366	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1367	>	* @param s the stream
1368	>	*/
1369	>	private void readObject(java.io.ObjectInputStream s)
1370	>	throws java.io.IOException, ClassNotFoundException {
1371	>	/*
1372	>	* To improve performance in typical cases, we create nodes
1373	>	* while reading, then place in table once size is known.
1374	>	* However, we must also validate uniqueness and deal with
1375	>	* overpopulated bins while doing so, which requires
1376	>	* specialized versions of putVal mechanics.
1377	>	*/
1378	>	sizeCtl = -1; // force exclusion for table construction
1379	>	s.defaultReadObject();
1380	>	long size = 0L;
1381	>	Node<K,V> p = null;
1382	>	for (;;) {
1383	>	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1384	>	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1385	>	if (k != null && v != null) {
1386	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1387	>	++size;
1388	>	}
1389	>	else
1390	>	break;
1391	>	}
1392	>	if (size == 0L)
1393	>	sizeCtl = 0;
1394	>	else {
1395	>	int n;
1396	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1397	>	n = MAXIMUM_CAPACITY;
1398	>	else {
1399	>	int sz = (int)size;
1400	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1401	>	}
1402	>	@SuppressWarnings({"rawtypes","unchecked"})
1403	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1404	>	int mask = n - 1;
1405	>	long added = 0L;
1406	>	while (p != null) {
1407	>	boolean insertAtFront;
1408	>	Node<K,V> next = p.next, first;
1409	>	int h = p.hash, j = h & mask;
1410	>	if ((first = tabAt(tab, j)) == null)
1411	>	insertAtFront = true;
1412	>	else {
1413	>	K k = p.key;
1414	>	if (first.hash < 0) {
1415	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1416	>	if (t.putTreeVal(h, k, p.val) == null)
1417	>	++added;
1418	>	insertAtFront = false;
1419	>	}
1420	>	else {
1421	>	int binCount = 0;
1422	>	insertAtFront = true;
1423	>	Node<K,V> q; K qk;
1424	>	for (q = first; q != null; q = q.next) {
1425	>	if (q.hash == h &&
1426	>	((qk = q.key) == k ||
1427	>	(qk != null && k.equals(qk)))) {
1428	>	insertAtFront = false;
1429	>	break;
1430	>	}
1431	>	++binCount;
1432	>	}
1433	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1434	>	insertAtFront = false;
1435	>	++added;
1436	>	p.next = first;
1437	>	TreeNode<K,V> hd = null, tl = null;
1438	>	for (q = p; q != null; q = q.next) {
1439	>	TreeNode<K,V> t = new TreeNode<K,V>
1440	>	(q.hash, q.key, q.val, null, null);
1441	>	if ((t.prev = tl) == null)
1442	>	hd = t;
1443	>	else
1444	>	tl.next = t;
1445	>	tl = t;
1446	>	}
1447	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1448	>	}
1449	>	}
1450	>	}
1451	>	if (insertAtFront) {
1452	>	++added;
1453	>	p.next = first;
1454	>	setTabAt(tab, j, p);
1455	>	}
1456	>	p = next;
1457	>	}
1458	>	table = tab;
1459	>	sizeCtl = n - (n >>> 2);
1460	>	baseCount = added;
1461	>	}
1462	>	}
1463	>
1464	>	// ConcurrentMap methods
1465	>
1466	>	/**
1467	>	* {@inheritDoc}
1468		*
1469	<	* @since 1.6
1469	>	* @return the previous value associated with the specified key,
1470	>	*         or {@code null} if there was no mapping for the key
1471	>	* @throws NullPointerException if the specified key or value is null
1472		*/
1473	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
1474	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1473	>	public V putIfAbsent(K key, V value) {
1474	>	return putVal(key, value, true);
1475		}
1476
1477		/**
1478	<	* Creates a new, empty map with the specified initial capacity,
758	<	* and with default load factor (0.75) and concurrencyLevel (16).
1478	>	* {@inheritDoc}
1479		*
1480	<	* @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.
1480	>	* @throws NullPointerException if the specified key is null
1481		*/
1482	<	public ConcurrentHashMap(int initialCapacity) {
1483	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1482	>	public boolean remove(Object key, Object value) {
1483	>	if (key == null)
1484	>	throw new NullPointerException();
1485	>	return value != null && replaceNode(key, null, value) != null;
1486		}
1487
1488		/**
1489	<	* Creates a new, empty map with a default initial capacity (16),
1490	<	* load factor (0.75) and concurrencyLevel (16).
1489	>	* {@inheritDoc}
1490	>	*
1491	>	* @throws NullPointerException if any of the arguments are null
1492		*/
1493	<	public ConcurrentHashMap() {
1494	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1493	>	public boolean replace(K key, V oldValue, V newValue) {
1494	>	if (key == null || oldValue == null || newValue == null)
1495	>	throw new NullPointerException();
1496	>	return replaceNode(key, newValue, oldValue) != null;
1497		}
1498
1499		/**
1500	<	* 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).
1500	>	* {@inheritDoc}
1501		*
1502	<	* @param m the map
1502	>	* @return the previous value associated with the specified key,
1503	>	*         or {@code null} if there was no mapping for the key
1504	>	* @throws NullPointerException if the specified key or value is null
1505		*/
1506	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1507	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1508	<	DEFAULT_INITIAL_CAPACITY),
1509	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
1506	>	public V replace(K key, V value) {
1507	>	if (key == null || value == null)
1508	>	throw new NullPointerException();
1509	>	return replaceNode(key, value, null);
1510		}
1511
1512	+	// Overrides of JDK8+ Map extension method defaults
1513	+
1514		/**
1515	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1515	>	* Returns the value to which the specified key is mapped, or the
1516	>	* given default value if this map contains no mapping for the
1517	>	* key.
1518		*
1519	<	* @return <tt>true</tt> if this map contains no key-value mappings
1519	>	* @param key the key whose associated value is to be returned
1520	>	* @param defaultValue the value to return if this map contains
1521	>	* no mapping for the given key
1522	>	* @return the mapping for the key, if present; else the default value
1523	>	* @throws NullPointerException if the specified key is null
1524		*/
1525	<	public boolean isEmpty() {
1526	<	/*
1527	<	* Sum per-segment modCounts to avoid mis-reporting when
1528	<	* elements are concurrently added and removed in one segment
1529	<	* while checking another, in which case the table was never
1530	<	* actually empty at any point. (The sum ensures accuracy up
1531	<	* through at least 1<<31 per-segment modifications before
1532	<	* recheck.)  Methods size() and containsValue() use similar
1533	<	* constructions for stability checks.
1534	<	*/
1535	<	long sum = 0L;
1536	<	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;
1525	>	public V getOrDefault(Object key, V defaultValue) {
1526	>	V v;
1527	>	return (v = get(key)) == null ? defaultValue : v;
1528	>	}
1529	>
1530	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1531	>	if (action == null) throw new NullPointerException();
1532	>	Node<K,V>[] t;
1533	>	if ((t = table) != null) {
1534	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1535	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1536	>	action.accept(p.key, p.val);
1537		}
1538		}
1539	<	if (sum != 0L) { // recheck unless no modifications
1540	<	for (int j = 0; j < segments.length; ++j) {
1541	<	Segment<K,V> seg = segmentAt(segments, j);
1542	<	if (seg != null) {
1543	<	if (seg.count != 0)
1544	<	return false;
1545	<	sum -= seg.modCount;
1539	>	}
1540	>
1541	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1542	>	if (function == null) throw new NullPointerException();
1543	>	Node<K,V>[] t;
1544	>	if ((t = table) != null) {
1545	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1546	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1547	>	V oldValue = p.val;
1548	>	for (K key = p.key;;) {
1549	>	V newValue = function.apply(key, oldValue);
1550	>	if (newValue == null)
1551	>	throw new NullPointerException();
1552	>	if (replaceNode(key, newValue, oldValue) != null ||
1553	>	(oldValue = get(key)) == null)
1554	>	break;
1555		}
1556		}
826	–	if (sum != 0L)
827	–	return false;
1557		}
829	–	return true;
1558		}
1559
1560		/**
1561	<	* Returns the number of key-value mappings in this map.  If the
1562	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
1563	<	* <tt>Integer.MAX_VALUE</tt>.
1561	>	* If the specified key is not already associated with a value,
1562	>	* attempts to compute its value using the given mapping function
1563	>	* and enters it into this map unless {@code null}.  The entire
1564	>	* method invocation is performed atomically, so the function is
1565	>	* applied at most once per key.  Some attempted update operations
1566	>	* on this map by other threads may be blocked while computation
1567	>	* is in progress, so the computation should be short and simple,
1568	>	* and must not attempt to update any other mappings of this map.
1569		*
1570	<	* @return the number of key-value mappings in this map
1570	>	* @param key key with which the specified value is to be associated
1571	>	* @param mappingFunction the function to compute a value
1572	>	* @return the current (existing or computed) value associated with
1573	>	*         the specified key, or null if the computed value is null
1574	>	* @throws NullPointerException if the specified key or mappingFunction
1575	>	*         is null
1576	>	* @throws IllegalStateException if the computation detectably
1577	>	*         attempts a recursive update to this map that would
1578	>	*         otherwise never complete
1579	>	* @throws RuntimeException or Error if the mappingFunction does so,
1580	>	*         in which case the mapping is left unestablished
1581		*/
1582	<	public int size() {
1583	<	// Try a few times to get accurate count. On failure due to
1584	<	// continuous async changes in table, resort to locking.
1585	<	final Segment<K,V>[] segments = this.segments;
1586	<	final int segmentCount = segments.length;
1587	<
1588	<	long previousSum = 0L;
1589	<	for (int retries = -1; retries < RETRIES_BEFORE_LOCK; retries++) {
1590	<	long sum = 0L;    // sum of modCounts
1591	<	long size = 0L;
1592	<	for (int i = 0; i < segmentCount; i++) {
1593	<	Segment<K,V> segment = segmentAt(segments, i);
1594	<	if (segment != null) {
1595	<	sum += segment.modCount;
1596	<	size += segment.count;
1597	<	}
1598	<	}
1599	<	if (sum == previousSum)
1600	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1601	<	previousSum = sum;
1582	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1583	>	if (key == null || mappingFunction == null)
1584	>	throw new NullPointerException();
1585	>	int h = spread(key.hashCode());
1586	>	V val = null;
1587	>	int binCount = 0;
1588	>	for (Node<K,V>[] tab = table;;) {
1589	>	Node<K,V> f; int n, i, fh;
1590	>	if (tab == null || (n = tab.length) == 0)
1591	>	tab = initTable();
1592	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1593	>	Node<K,V> r = new ReservationNode<K,V>();
1594	>	synchronized (r) {
1595	>	if (casTabAt(tab, i, null, r)) {
1596	>	binCount = 1;
1597	>	Node<K,V> node = null;
1598	>	try {
1599	>	if ((val = mappingFunction.apply(key)) != null)
1600	>	node = new Node<K,V>(h, key, val, null);
1601	>	} finally {
1602	>	setTabAt(tab, i, node);
1603	>	}
1604	>	}
1605	>	}
1606	>	if (binCount != 0)
1607	>	break;
1608	>	}
1609	>	else if ((fh = f.hash) == MOVED)
1610	>	tab = helpTransfer(tab, f);
1611	>	else {
1612	>	boolean added = false;
1613	>	synchronized (f) {
1614	>	if (tabAt(tab, i) == f) {
1615	>	if (fh >= 0) {
1616	>	binCount = 1;
1617	>	for (Node<K,V> e = f;; ++binCount) {
1618	>	K ek; V ev;
1619	>	if (e.hash == h &&
1620	>	((ek = e.key) == key ||
1621	>	(ek != null && key.equals(ek)))) {
1622	>	val = e.val;
1623	>	break;
1624	>	}
1625	>	Node<K,V> pred = e;
1626	>	if ((e = e.next) == null) {
1627	>	if ((val = mappingFunction.apply(key)) != null) {
1628	>	added = true;
1629	>	pred.next = new Node<K,V>(h, key, val, null);
1630	>	}
1631	>	break;
1632	>	}
1633	>	}
1634	>	}
1635	>	else if (f instanceof TreeBin) {
1636	>	binCount = 2;
1637	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1638	>	TreeNode<K,V> r, p;
1639	>	if ((r = t.root) != null &&
1640	>	(p = r.findTreeNode(h, key, null)) != null)
1641	>	val = p.val;
1642	>	else if ((val = mappingFunction.apply(key)) != null) {
1643	>	added = true;
1644	>	t.putTreeVal(h, key, val);
1645	>	}
1646	>	}
1647	>	}
1648	>	}
1649	>	if (binCount != 0) {
1650	>	if (binCount >= TREEIFY_THRESHOLD)
1651	>	treeifyBin(tab, i);
1652	>	if (!added)
1653	>	return val;
1654	>	break;
1655	>	}
1656	>	}
1657		}
1658	<
1659	<	long size = 0L;
1660	<	for (int i = 0; i < segmentCount; i++) {
863	<	Segment<K,V> segment = ensureSegment(i);
864	<	segment.lock();
865	<	size += segment.count;
866	<	}
867	<	for (int i = 0; i < segmentCount; i++)
868	<	segments[i].unlock();
869	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1658	>	if (val != null)
1659	>	addCount(1L, binCount);
1660	>	return val;
1661		}
1662
1663		/**
1664	<	* Returns the value to which the specified key is mapped,
1665	<	* or {@code null} if this map contains no mapping for the key.
1666	<	*
1667	<	* <p>More formally, if this map contains a mapping from a key
1668	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1669	<	* then this method returns {@code v}; otherwise it returns
1670	<	* {@code null}.  (There can be at most one such mapping.)
1664	>	* If the value for the specified key is present, attempts to
1665	>	* compute a new mapping given the key and its current mapped
1666	>	* value.  The entire method invocation is performed atomically.
1667	>	* Some attempted update operations on this map by other threads
1668	>	* may be blocked while computation is in progress, so the
1669	>	* computation should be short and simple, and must not attempt to
1670	>	* update any other mappings of this map.
1671		*
1672	<	* @throws NullPointerException if the specified key is null
1672	>	* @param key key with which a value may be associated
1673	>	* @param remappingFunction the function to compute a value
1674	>	* @return the new value associated with the specified key, or null if none
1675	>	* @throws NullPointerException if the specified key or remappingFunction
1676	>	*         is null
1677	>	* @throws IllegalStateException if the computation detectably
1678	>	*         attempts a recursive update to this map that would
1679	>	*         otherwise never complete
1680	>	* @throws RuntimeException or Error if the remappingFunction does so,
1681	>	*         in which case the mapping is unchanged
1682		*/
1683	<	public V get(Object key) {
1684	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1685	<	HashEntry<K,V>[] tab;
1686	<	int h = hash(key.hashCode());
1687	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1688	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1689	<	(tab = s.table) != null) {
1690	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1691	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1692	<	e != null; e = e.next) {
1693	<	K k;
1694	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1695	<	return e.value;
1683	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1684	>	if (key == null || remappingFunction == null)
1685	>	throw new NullPointerException();
1686	>	int h = spread(key.hashCode());
1687	>	V val = null;
1688	>	int delta = 0;
1689	>	int binCount = 0;
1690	>	for (Node<K,V>[] tab = table;;) {
1691	>	Node<K,V> f; int n, i, fh;
1692	>	if (tab == null || (n = tab.length) == 0)
1693	>	tab = initTable();
1694	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1695	>	break;
1696	>	else if ((fh = f.hash) == MOVED)
1697	>	tab = helpTransfer(tab, f);
1698	>	else {
1699	>	synchronized (f) {
1700	>	if (tabAt(tab, i) == f) {
1701	>	if (fh >= 0) {
1702	>	binCount = 1;
1703	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1704	>	K ek;
1705	>	if (e.hash == h &&
1706	>	((ek = e.key) == key ||
1707	>	(ek != null && key.equals(ek)))) {
1708	>	val = remappingFunction.apply(key, e.val);
1709	>	if (val != null)
1710	>	e.val = val;
1711	>	else {
1712	>	delta = -1;
1713	>	Node<K,V> en = e.next;
1714	>	if (pred != null)
1715	>	pred.next = en;
1716	>	else
1717	>	setTabAt(tab, i, en);
1718	>	}
1719	>	break;
1720	>	}
1721	>	pred = e;
1722	>	if ((e = e.next) == null)
1723	>	break;
1724	>	}
1725	>	}
1726	>	else if (f instanceof TreeBin) {
1727	>	binCount = 2;
1728	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1729	>	TreeNode<K,V> r, p;
1730	>	if ((r = t.root) != null &&
1731	>	(p = r.findTreeNode(h, key, null)) != null) {
1732	>	val = remappingFunction.apply(key, p.val);
1733	>	if (val != null)
1734	>	p.val = val;
1735	>	else {
1736	>	delta = -1;
1737	>	if (t.removeTreeNode(p))
1738	>	setTabAt(tab, i, untreeify(t.first));
1739	>	}
1740	>	}
1741	>	}
1742	>	}
1743	>	}
1744	>	if (binCount != 0)
1745	>	break;
1746		}
1747		}
1748	<	return null;
1748	>	if (delta != 0)
1749	>	addCount((long)delta, binCount);
1750	>	return val;
1751		}
1752
1753		/**
1754	<	* Tests if the specified object is a key in this table.
1754	>	* Attempts to compute a mapping for the specified key and its
1755	>	* current mapped value (or {@code null} if there is no current
1756	>	* mapping). The entire method invocation is performed atomically.
1757	>	* Some attempted update operations on this map by other threads
1758	>	* may be blocked while computation is in progress, so the
1759	>	* computation should be short and simple, and must not attempt to
1760	>	* update any other mappings of this Map.
1761		*
1762	<	* @param  key   possible key
1763	<	* @return <tt>true</tt> if and only if the specified object
1764	<	*         is a key in this table, as determined by the
1765	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1766	<	* @throws NullPointerException if the specified key is null
1767	<	*/
1768	<	@SuppressWarnings("unchecked")
1769	<	public boolean containsKey(Object key) {
1770	<	Segment<K,V> s; // same as get() except no need for volatile value read
1771	<	HashEntry<K,V>[] tab;
1772	<	int h = hash(key.hashCode());
1773	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1774	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1775	<	(tab = s.table) != null) {
1776	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1777	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1778	<	e != null; e = e.next) {
1779	<	K k;
1780	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1781	<	return true;
1762	>	* @param key key with which the specified value is to be associated
1763	>	* @param remappingFunction the function to compute a value
1764	>	* @return the new value associated with the specified key, or null if none
1765	>	* @throws NullPointerException if the specified key or remappingFunction
1766	>	*         is null
1767	>	* @throws IllegalStateException if the computation detectably
1768	>	*         attempts a recursive update to this map that would
1769	>	*         otherwise never complete
1770	>	* @throws RuntimeException or Error if the remappingFunction does so,
1771	>	*         in which case the mapping is unchanged
1772	>	*/
1773	>	public V compute(K key,
1774	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1775	>	if (key == null || remappingFunction == null)
1776	>	throw new NullPointerException();
1777	>	int h = spread(key.hashCode());
1778	>	V val = null;
1779	>	int delta = 0;
1780	>	int binCount = 0;
1781	>	for (Node<K,V>[] tab = table;;) {
1782	>	Node<K,V> f; int n, i, fh;
1783	>	if (tab == null || (n = tab.length) == 0)
1784	>	tab = initTable();
1785	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1786	>	Node<K,V> r = new ReservationNode<K,V>();
1787	>	synchronized (r) {
1788	>	if (casTabAt(tab, i, null, r)) {
1789	>	binCount = 1;
1790	>	Node<K,V> node = null;
1791	>	try {
1792	>	if ((val = remappingFunction.apply(key, null)) != null) {
1793	>	delta = 1;
1794	>	node = new Node<K,V>(h, key, val, null);
1795	>	}
1796	>	} finally {
1797	>	setTabAt(tab, i, node);
1798	>	}
1799	>	}
1800	>	}
1801	>	if (binCount != 0)
1802	>	break;
1803	>	}
1804	>	else if ((fh = f.hash) == MOVED)
1805	>	tab = helpTransfer(tab, f);
1806	>	else {
1807	>	synchronized (f) {
1808	>	if (tabAt(tab, i) == f) {
1809	>	if (fh >= 0) {
1810	>	binCount = 1;
1811	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1812	>	K ek;
1813	>	if (e.hash == h &&
1814	>	((ek = e.key) == key ||
1815	>	(ek != null && key.equals(ek)))) {
1816	>	val = remappingFunction.apply(key, e.val);
1817	>	if (val != null)
1818	>	e.val = val;
1819	>	else {
1820	>	delta = -1;
1821	>	Node<K,V> en = e.next;
1822	>	if (pred != null)
1823	>	pred.next = en;
1824	>	else
1825	>	setTabAt(tab, i, en);
1826	>	}
1827	>	break;
1828	>	}
1829	>	pred = e;
1830	>	if ((e = e.next) == null) {
1831	>	val = remappingFunction.apply(key, null);
1832	>	if (val != null) {
1833	>	delta = 1;
1834	>	pred.next =
1835	>	new Node<K,V>(h, key, val, null);
1836	>	}
1837	>	break;
1838	>	}
1839	>	}
1840	>	}
1841	>	else if (f instanceof TreeBin) {
1842	>	binCount = 1;
1843	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1844	>	TreeNode<K,V> r, p;
1845	>	if ((r = t.root) != null)
1846	>	p = r.findTreeNode(h, key, null);
1847	>	else
1848	>	p = null;
1849	>	V pv = (p == null) ? null : p.val;
1850	>	val = remappingFunction.apply(key, pv);
1851	>	if (val != null) {
1852	>	if (p != null)
1853	>	p.val = val;
1854	>	else {
1855	>	delta = 1;
1856	>	t.putTreeVal(h, key, val);
1857	>	}
1858	>	}
1859	>	else if (p != null) {
1860	>	delta = -1;
1861	>	if (t.removeTreeNode(p))
1862	>	setTabAt(tab, i, untreeify(t.first));
1863	>	}
1864	>	}
1865	>	}
1866	>	}
1867	>	if (binCount != 0) {
1868	>	if (binCount >= TREEIFY_THRESHOLD)
1869	>	treeifyBin(tab, i);
1870	>	break;
1871	>	}
1872		}
1873		}
1874	<	return false;
1874	>	if (delta != 0)
1875	>	addCount((long)delta, binCount);
1876	>	return val;
1877		}
1878
1879		/**
1880	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1881	<	* specified value. Note: This method requires a full internal
1882	<	* traversal of the hash table, and so is much slower than
1883	<	* method <tt>containsKey</tt>.
1880	>	* If the specified key is not already associated with a
1881	>	* (non-null) value, associates it with the given value.
1882	>	* Otherwise, replaces the value with the results of the given
1883	>	* remapping function, or removes if {@code null}. The entire
1884	>	* method invocation is performed atomically.  Some attempted
1885	>	* update operations on this map by other threads may be blocked
1886	>	* while computation is in progress, so the computation should be
1887	>	* short and simple, and must not attempt to update any other
1888	>	* mappings of this Map.
1889		*
1890	<	* @param value value whose presence in this map is to be tested
1891	<	* @return <tt>true</tt> if this map maps one or more keys to the
1892	<	*         specified value
1893	<	* @throws NullPointerException if the specified value is null
1890	>	* @param key key with which the specified value is to be associated
1891	>	* @param value the value to use if absent
1892	>	* @param remappingFunction the function to recompute a value if present
1893	>	* @return the new value associated with the specified key, or null if none
1894	>	* @throws NullPointerException if the specified key or the
1895	>	*         remappingFunction is null
1896	>	* @throws RuntimeException or Error if the remappingFunction does so,
1897	>	*         in which case the mapping is unchanged
1898		*/
1899	<	public boolean containsValue(Object value) {
1900	<	// Same idea as size()
942	<	if (value == null)
1899	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1900	>	if (key == null || value == null || remappingFunction == null)
1901		throw new NullPointerException();
1902	<	final Segment<K,V>[] segments = this.segments;
1903	<	long previousSum = 0L;
1904	<	int lockCount = 0;
1905	<	try {
1906	<	for (int retries = -1; ; retries++) {
1907	<	long sum = 0L;    // sum of modCounts
1908	<	for (int j = 0; j < segments.length; j++) {
1909	<	Segment<K,V> segment;
1910	<	if (retries == RETRIES_BEFORE_LOCK) {
1911	<	segment = ensureSegment(j);
1912	<	segment.lock();
1913	<	lockCount++;
1914	<	} else {
1915	<	segment = segmentAt(segments, j);
1916	<	if (segment == null)
1917	<	continue;
1918	<	}
1919	<	HashEntry<K,V>[] tab = segment.table;
1920	<	if (tab != null) {
1921	<	for (int i = 0 ; i < tab.length; i++) {
1922	<	HashEntry<K,V> e;
1923	<	for (e = entryAt(tab, i); e != null; e = e.next) {
1924	<	V v = e.value;
1925	<	if (v != null && value.equals(v))
1926	<	return true;
1902	>	int h = spread(key.hashCode());
1903	>	V val = null;
1904	>	int delta = 0;
1905	>	int binCount = 0;
1906	>	for (Node<K,V>[] tab = table;;) {
1907	>	Node<K,V> f; int n, i, fh;
1908	>	if (tab == null || (n = tab.length) == 0)
1909	>	tab = initTable();
1910	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1911	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1912	>	delta = 1;
1913	>	val = value;
1914	>	break;
1915	>	}
1916	>	}
1917	>	else if ((fh = f.hash) == MOVED)
1918	>	tab = helpTransfer(tab, f);
1919	>	else {
1920	>	synchronized (f) {
1921	>	if (tabAt(tab, i) == f) {
1922	>	if (fh >= 0) {
1923	>	binCount = 1;
1924	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1925	>	K ek;
1926	>	if (e.hash == h &&
1927	>	((ek = e.key) == key ||
1928	>	(ek != null && key.equals(ek)))) {
1929	>	val = remappingFunction.apply(e.val, value);
1930	>	if (val != null)
1931	>	e.val = val;
1932	>	else {
1933	>	delta = -1;
1934	>	Node<K,V> en = e.next;
1935	>	if (pred != null)
1936	>	pred.next = en;
1937	>	else
1938	>	setTabAt(tab, i, en);
1939	>	}
1940	>	break;
1941	>	}
1942	>	pred = e;
1943	>	if ((e = e.next) == null) {
1944	>	delta = 1;
1945	>	val = value;
1946	>	pred.next =
1947	>	new Node<K,V>(h, key, val, null);
1948	>	break;
1949	>	}
1950	>	}
1951	>	}
1952	>	else if (f instanceof TreeBin) {
1953	>	binCount = 2;
1954	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1955	>	TreeNode<K,V> r = t.root;
1956	>	TreeNode<K,V> p = (r == null) ? null :
1957	>	r.findTreeNode(h, key, null);
1958	>	val = (p == null) ? value :
1959	>	remappingFunction.apply(p.val, value);
1960	>	if (val != null) {
1961	>	if (p != null)
1962	>	p.val = val;
1963	>	else {
1964	>	delta = 1;
1965	>	t.putTreeVal(h, key, val);
1966	>	}
1967	>	}
1968	>	else if (p != null) {
1969	>	delta = -1;
1970	>	if (t.removeTreeNode(p))
1971	>	setTabAt(tab, i, untreeify(t.first));
1972		}
1973		}
971	–	sum += segment.modCount;
1974		}
1975		}
1976	<	if ((retries >= 0 && sum == previousSum) || lockCount > 0)
1977	<	return false;
1978	<	previousSum = sum;
1976	>	if (binCount != 0) {
1977	>	if (binCount >= TREEIFY_THRESHOLD)
1978	>	treeifyBin(tab, i);
1979	>	break;
1980	>	}
1981		}
978	–	} finally {
979	–	for (int j = 0; j < lockCount; j++)
980	–	segments[j].unlock();
1982		}
1983	+	if (delta != 0)
1984	+	addCount((long)delta, binCount);
1985	+	return val;
1986		}
1987
1988	+	// Hashtable legacy methods
1989	+
1990		/**
1991		* Legacy method testing if some key maps into the specified value
1992		* in this table.  This method is identical in functionality to
1993	<	* {@link #containsValue}, and exists solely to ensure
1993	>	* {@link #containsValue(Object)}, and exists solely to ensure
1994		* full compatibility with class {@link java.util.Hashtable},
1995		* which supported this method prior to introduction of the
1996		* Java Collections framework.
1997		*
1998		* @param  value a value to search for
1999	<	* @return <tt>true</tt> if and only if some key maps to the
2000	<	*         <tt>value</tt> argument in this table as
2001	<	*         determined by the <tt>equals</tt> method;
2002	<	*         <tt>false</tt> otherwise
1999	>	* @return {@code true} if and only if some key maps to the
2000	>	*         {@code value} argument in this table as
2001	>	*         determined by the {@code equals} method;
2002	>	*         {@code false} otherwise
2003		* @throws NullPointerException if the specified value is null
2004		*/
2005	<	public boolean contains(Object value) {
2005	>	@Deprecated public boolean contains(Object value) {
2006		return containsValue(value);
2007		}
2008
2009		/**
2010	<	* Maps the specified key to the specified value in this table.
1005	<	* Neither the key nor the value can be null.
1006	<	*
1007	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1008	<	* with a key that is equal to the original key.
2010	>	* Returns an enumeration of the keys in this table.
2011		*
2012	<	* @param key key with which the specified value is to be associated
2013	<	* @param value value to be associated with the specified key
1012	<	* @return the previous value associated with <tt>key</tt>, or
1013	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1014	<	* @throws NullPointerException if the specified key or value is null
2012	>	* @return an enumeration of the keys in this table
2013	>	* @see #keySet()
2014		*/
2015	<	@SuppressWarnings("unchecked")
2016	<	public V put(K key, V value) {
2017	<	Segment<K,V> s;
2018	<	if (value == null)
1020	<	throw new NullPointerException();
1021	<	int hash = hash(key.hashCode());
1022	<	int j = (hash >>> segmentShift) & segmentMask;
1023	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1024	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1025	<	s = ensureSegment(j);
1026	<	return s.put(key, hash, value, false);
2015	>	public Enumeration<K> keys() {
2016	>	Node<K,V>[] t;
2017	>	int f = (t = table) == null ? 0 : t.length;
2018	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2019		}
2020
2021		/**
2022	<	* {@inheritDoc}
2022	>	* Returns an enumeration of the values in this table.
2023		*
2024	<	* @return the previous value associated with the specified key,
2025	<	*         or <tt>null</tt> if there was no mapping for the key
1034	<	* @throws NullPointerException if the specified key or value is null
2024	>	* @return an enumeration of the values in this table
2025	>	* @see #values()
2026		*/
2027	<	@SuppressWarnings("unchecked")
2028	<	public V putIfAbsent(K key, V value) {
2029	<	Segment<K,V> s;
2030	<	if (value == null)
1040	<	throw new NullPointerException();
1041	<	int hash = hash(key.hashCode());
1042	<	int j = (hash >>> segmentShift) & segmentMask;
1043	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1044	<	(segments, (j << SSHIFT) + SBASE)) == null)
1045	<	s = ensureSegment(j);
1046	<	return s.put(key, hash, value, true);
2027	>	public Enumeration<V> elements() {
2028	>	Node<K,V>[] t;
2029	>	int f = (t = table) == null ? 0 : t.length;
2030	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2031		}
2032
2033	+	// ConcurrentHashMap-only methods
2034	+
2035		/**
2036	<	* Copies all of the mappings from the specified map to this one.
2037	<	* These mappings replace any mappings that this map had for any of the
2038	<	* keys currently in the specified map.
2036	>	* Returns the number of mappings. This method should be used
2037	>	* instead of {@link #size} because a ConcurrentHashMap may
2038	>	* contain more mappings than can be represented as an int. The
2039	>	* value returned is an estimate; the actual count may differ if
2040	>	* there are concurrent insertions or removals.
2041		*
2042	<	* @param m mappings to be stored in this map
2042	>	* @return the number of mappings
2043	>	* @since 1.8
2044		*/
2045	<	public void putAll(Map<? extends K, ? extends V> m) {
2046	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2047	<	put(e.getKey(), e.getValue());
2045	>	public long mappingCount() {
2046	>	long n = sumCount();
2047	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2048		}
2049
2050		/**
2051	<	* Removes the key (and its corresponding value) from this map.
2052	<	* This method does nothing if the key is not in the map.
2051	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2052	>	* from the given type to {@code Boolean.TRUE}.
2053		*
2054	<	* @param  key the key that needs to be removed
2055	<	* @return the previous value associated with <tt>key</tt>, or
2056	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1068	<	* @throws NullPointerException if the specified key is null
2054	>	* @param <K> the element type of the returned set
2055	>	* @return the new set
2056	>	* @since 1.8
2057		*/
2058	<	public V remove(Object key) {
2059	<	int hash = hash(key.hashCode());
2060	<	Segment<K,V> s = segmentForHash(hash);
1073	<	return s == null ? null : s.remove(key, hash, null);
2058	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2059	>	return new KeySetView<K,Boolean>
2060	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2061		}
2062
2063		/**
2064	<	* {@inheritDoc}
2064	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2065	>	* from the given type to {@code Boolean.TRUE}.
2066		*
2067	<	* @throws NullPointerException if the specified key is null
2067	>	* @param initialCapacity The implementation performs internal
2068	>	* sizing to accommodate this many elements.
2069	>	* @param <K> the element type of the returned set
2070	>	* @throws IllegalArgumentException if the initial capacity of
2071	>	* elements is negative
2072	>	* @return the new set
2073	>	* @since 1.8
2074		*/
2075	<	public boolean remove(Object key, Object value) {
2076	<	int hash = hash(key.hashCode());
2077	<	Segment<K,V> s;
1084	<	return value != null && (s = segmentForHash(hash)) != null &&
1085	<	s.remove(key, hash, value) != null;
2075	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2076	>	return new KeySetView<K,Boolean>
2077	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2078		}
2079
2080		/**
2081	<	* {@inheritDoc}
2081	>	* Returns a {@link Set} view of the keys in this map, using the
2082	>	* given common mapped value for any additions (i.e., {@link
2083	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2084	>	* This is of course only appropriate if it is acceptable to use
2085	>	* the same value for all additions from this view.
2086		*
2087	<	* @throws NullPointerException if any of the arguments are null
2087	>	* @param mappedValue the mapped value to use for any additions
2088	>	* @return the set view
2089	>	* @throws NullPointerException if the mappedValue is null
2090		*/
2091	<	public boolean replace(K key, V oldValue, V newValue) {
2092	<	int hash = hash(key.hashCode());
1095	<	if (oldValue == null || newValue == null)
2091	>	public KeySetView<K,V> keySet(V mappedValue) {
2092	>	if (mappedValue == null)
2093		throw new NullPointerException();
2094	<	Segment<K,V> s = segmentForHash(hash);
1098	<	return s != null && s.replace(key, hash, oldValue, newValue);
2094	>	return new KeySetView<K,V>(this, mappedValue);
2095		}
2096
2097	+	/* ---------------- Special Nodes -------------- */
2098	+
2099		/**
2100	<	* {@inheritDoc}
1103	<	*
1104	<	* @return the previous value associated with the specified key,
1105	<	*         or <tt>null</tt> if there was no mapping for the key
1106	<	* @throws NullPointerException if the specified key or value is null
2100	>	* A node inserted at head of bins during transfer operations.
2101		*/
2102	<	public V replace(K key, V value) {
2103	<	int hash = hash(key.hashCode());
2104	<	if (value == null)
2105	<	throw new NullPointerException();
2106	<	Segment<K,V> s = segmentForHash(hash);
2107	<	return s == null ? null : s.replace(key, hash, value);
2102	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2103	>	final Node<K,V>[] nextTable;
2104	>	ForwardingNode(Node<K,V>[] tab) {
2105	>	super(MOVED, null, null, null);
2106	>	this.nextTable = tab;
2107	>	}
2108	>
2109	>	Node<K,V> find(int h, Object k) {
2110	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2111	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2112	>	Node<K,V> e; int n;
2113	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2114	>	(e = tabAt(tab, (n - 1) & h)) == null)
2115	>	return null;
2116	>	for (;;) {
2117	>	int eh; K ek;
2118	>	if ((eh = e.hash) == h &&
2119	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2120	>	return e;
2121	>	if (eh < 0) {
2122	>	if (e instanceof ForwardingNode) {
2123	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2124	>	continue outer;
2125	>	}
2126	>	else
2127	>	return e.find(h, k);
2128	>	}
2129	>	if ((e = e.next) == null)
2130	>	return null;
2131	>	}
2132	>	}
2133	>	}
2134		}
2135
2136		/**
2137	<	* Removes all of the mappings from this map.
2137	>	* A place-holder node used in computeIfAbsent and compute
2138		*/
2139	<	public void clear() {
2140	<	final Segment<K,V>[] segments = this.segments;
2141	<	for (int j = 0; j < segments.length; ++j) {
2142	<	Segment<K,V> s = segmentAt(segments, j);
2143	<	if (s != null)
2144	<	s.clear();
2139	>	static final class ReservationNode<K,V> extends Node<K,V> {
2140	>	ReservationNode() {
2141	>	super(RESERVED, null, null, null);
2142	>	}
2143	>
2144	>	Node<K,V> find(int h, Object k) {
2145	>	return null;
2146		}
2147		}
2148
2149	+	/* ---------------- Table Initialization and Resizing -------------- */
2150	+
2151		/**
2152	<	* Returns a {@link Set} view of the keys contained in this map.
1130	<	* The set is backed by the map, so changes to the map are
1131	<	* reflected in the set, and vice-versa.  The set supports element
1132	<	* removal, which removes the corresponding mapping from this map,
1133	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1134	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1135	<	* operations.  It does not support the <tt>add</tt> or
1136	<	* <tt>addAll</tt> operations.
1137	<	*
1138	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1139	<	* that will never throw {@link ConcurrentModificationException},
1140	<	* and guarantees to traverse elements as they existed upon
1141	<	* construction of the iterator, and may (but is not guaranteed to)
1142	<	* reflect any modifications subsequent to construction.
2152	>	* Initializes table, using the size recorded in sizeCtl.
2153		*/
2154	<	public Set<K> keySet() {
2155	<	Set<K> ks = keySet;
2156	<	return (ks != null) ? ks : (keySet = new KeySet());
2154	>	private final Node<K,V>[] initTable() {
2155	>	Node<K,V>[] tab; int sc;
2156	>	while ((tab = table) == null || tab.length == 0) {
2157	>	if ((sc = sizeCtl) < 0)
2158	>	Thread.yield(); // lost initialization race; just spin
2159	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2160	>	try {
2161	>	if ((tab = table) == null || tab.length == 0) {
2162	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2163	>	@SuppressWarnings({"rawtypes","unchecked"})
2164	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2165	>	table = tab = nt;
2166	>	sc = n - (n >>> 2);
2167	>	}
2168	>	} finally {
2169	>	sizeCtl = sc;
2170	>	}
2171	>	break;
2172	>	}
2173	>	}
2174	>	return tab;
2175		}
2176
2177		/**
2178	<	* Returns a {@link Collection} view of the values contained in this map.
2179	<	* The collection is backed by the map, so changes to the map are
2180	<	* reflected in the collection, and vice-versa.  The collection
2181	<	* supports element removal, which removes the corresponding
2182	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1155	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1156	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1157	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
2178	>	* Adds to count, and if table is too small and not already
2179	>	* resizing, initiates transfer. If already resizing, helps
2180	>	* perform transfer if work is available.  Rechecks occupancy
2181	>	* after a transfer to see if another resize is already needed
2182	>	* because resizings are lagging additions.
2183		*
2184	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2185	<	* that will never throw {@link ConcurrentModificationException},
1161	<	* and guarantees to traverse elements as they existed upon
1162	<	* construction of the iterator, and may (but is not guaranteed to)
1163	<	* reflect any modifications subsequent to construction.
2184	>	* @param x the count to add
2185	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2186		*/
2187	<	public Collection<V> values() {
2188	<	Collection<V> vs = values;
2189	<	return (vs != null) ? vs : (values = new Values());
2187	>	private final void addCount(long x, int check) {
2188	>	CounterCell[] as; long b, s;
2189	>	if ((as = counterCells) != null ||
2190	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2191	>	CounterCell a; long v; int m;
2192	>	boolean uncontended = true;
2193	>	if (as == null || (m = as.length - 1) < 0 ||
2194	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2195	>	!(uncontended =
2196	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2197	>	fullAddCount(x, uncontended);
2198	>	return;
2199	>	}
2200	>	if (check <= 1)
2201	>	return;
2202	>	s = sumCount();
2203	>	}
2204	>	if (check >= 0) {
2205	>	Node<K,V>[] tab, nt; int sc;
2206	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2207	>	tab.length < MAXIMUM_CAPACITY) {
2208	>	if (sc < 0) {
2209	>	if (sc == -1 || transferIndex <= transferOrigin ||
2210	>	(nt = nextTable) == null)
2211	>	break;
2212	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2213	>	transfer(tab, nt);
2214	>	}
2215	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2216	>	transfer(tab, null);
2217	>	s = sumCount();
2218	>	}
2219	>	}
2220		}
2221
2222		/**
2223	<	* Returns a {@link Set} view of the mappings contained in this map.
1172	<	* The set is backed by the map, so changes to the map are
1173	<	* reflected in the set, and vice-versa.  The set supports element
1174	<	* removal, which removes the corresponding mapping from the map,
1175	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1176	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1177	<	* operations.  It does not support the <tt>add</tt> or
1178	<	* <tt>addAll</tt> operations.
1179	<	*
1180	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1181	<	* that will never throw {@link ConcurrentModificationException},
1182	<	* and guarantees to traverse elements as they existed upon
1183	<	* construction of the iterator, and may (but is not guaranteed to)
1184	<	* reflect any modifications subsequent to construction.
2223	>	* Helps transfer if a resize is in progress.
2224		*/
2225	<	public Set<Map.Entry<K,V>> entrySet() {
2226	<	Set<Map.Entry<K,V>> es = entrySet;
2227	<	return (es != null) ? es : (entrySet = new EntrySet());
2225	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2226	>	Node<K,V>[] nextTab; int sc;
2227	>	if ((f instanceof ForwardingNode) &&
2228	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2229	>	if (nextTab == nextTable && tab == table &&
2230	>	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2231	>	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2232	>	transfer(tab, nextTab);
2233	>	return nextTab;
2234	>	}
2235	>	return table;
2236		}
2237
2238		/**
2239	<	* Returns an enumeration of the keys in this table.
2239	>	* Tries to presize table to accommodate the given number of elements.
2240		*
2241	<	* @return an enumeration of the keys in this table
1195	<	* @see #keySet()
2241	>	* @param size number of elements (doesn't need to be perfectly accurate)
2242		*/
2243	<	public Enumeration<K> keys() {
2244	<	return new KeyIterator();
2243	>	private final void tryPresize(int size) {
2244	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2245	>	tableSizeFor(size + (size >>> 1) + 1);
2246	>	int sc;
2247	>	while ((sc = sizeCtl) >= 0) {
2248	>	Node<K,V>[] tab = table; int n;
2249	>	if (tab == null || (n = tab.length) == 0) {
2250	>	n = (sc > c) ? sc : c;
2251	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2252	>	try {
2253	>	if (table == tab) {
2254	>	@SuppressWarnings({"rawtypes","unchecked"})
2255	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2256	>	table = nt;
2257	>	sc = n - (n >>> 2);
2258	>	}
2259	>	} finally {
2260	>	sizeCtl = sc;
2261	>	}
2262	>	}
2263	>	}
2264	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2265	>	break;
2266	>	else if (tab == table &&
2267	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2268	>	transfer(tab, null);
2269	>	}
2270		}
2271
2272		/**
2273	<	* Returns an enumeration of the values in this table.
2274	<	*
1204	<	* @return an enumeration of the values in this table
1205	<	* @see #values()
2273	>	* Moves and/or copies the nodes in each bin to new table. See
2274	>	* above for explanation.
2275		*/
2276	<	public Enumeration<V> elements() {
2277	<	return new ValueIterator();
2276	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2277	>	int n = tab.length, stride;
2278	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2279	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2280	>	if (nextTab == null) {            // initiating
2281	>	try {
2282	>	@SuppressWarnings({"rawtypes","unchecked"})
2283	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2284	>	nextTab = nt;
2285	>	} catch (Throwable ex) {      // try to cope with OOME
2286	>	sizeCtl = Integer.MAX_VALUE;
2287	>	return;
2288	>	}
2289	>	nextTable = nextTab;
2290	>	transferOrigin = n;
2291	>	transferIndex = n;
2292	>	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2293	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
2294	>	int nextk = (k > stride) ? k - stride : 0;
2295	>	for (int m = nextk; m < k; ++m)
2296	>	nextTab[m] = rev;
2297	>	for (int m = n + nextk; m < n + k; ++m)
2298	>	nextTab[m] = rev;
2299	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2300	>	}
2301	>	}
2302	>	int nextn = nextTab.length;
2303	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2304	>	boolean advance = true;
2305	>	boolean finishing = false; // to ensure sweep before committing nextTab
2306	>	for (int i = 0, bound = 0;;) {
2307	>	int nextIndex, nextBound, fh; Node<K,V> f;
2308	>	while (advance) {
2309	>	if (--i >= bound || finishing)
2310	>	advance = false;
2311	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
2312	>	i = -1;
2313	>	advance = false;
2314	>	}
2315	>	else if (U.compareAndSwapInt
2316	>	(this, TRANSFERINDEX, nextIndex,
2317	>	nextBound = (nextIndex > stride ?
2318	>	nextIndex - stride : 0))) {
2319	>	bound = nextBound;
2320	>	i = nextIndex - 1;
2321	>	advance = false;
2322	>	}
2323	>	}
2324	>	if (i < 0 || i >= n || i + n >= nextn) {
2325	>	if (finishing) {
2326	>	nextTable = null;
2327	>	table = nextTab;
2328	>	sizeCtl = (n << 1) - (n >>> 1);
2329	>	return;
2330	>	}
2331	>	for (int sc;;) {
2332	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2333	>	if (sc != -1)
2334	>	return;
2335	>	finishing = advance = true;
2336	>	i = n; // recheck before commit
2337	>	break;
2338	>	}
2339	>	}
2340	>	}
2341	>	else if ((f = tabAt(tab, i)) == null) {
2342	>	if (casTabAt(tab, i, null, fwd)) {
2343	>	setTabAt(nextTab, i, null);
2344	>	setTabAt(nextTab, i + n, null);
2345	>	advance = true;
2346	>	}
2347	>	}
2348	>	else if ((fh = f.hash) == MOVED)
2349	>	advance = true; // already processed
2350	>	else {
2351	>	synchronized (f) {
2352	>	if (tabAt(tab, i) == f) {
2353	>	Node<K,V> ln, hn;
2354	>	if (fh >= 0) {
2355	>	int runBit = fh & n;
2356	>	Node<K,V> lastRun = f;
2357	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2358	>	int b = p.hash & n;
2359	>	if (b != runBit) {
2360	>	runBit = b;
2361	>	lastRun = p;
2362	>	}
2363	>	}
2364	>	if (runBit == 0) {
2365	>	ln = lastRun;
2366	>	hn = null;
2367	>	}
2368	>	else {
2369	>	hn = lastRun;
2370	>	ln = null;
2371	>	}
2372	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2373	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2374	>	if ((ph & n) == 0)
2375	>	ln = new Node<K,V>(ph, pk, pv, ln);
2376	>	else
2377	>	hn = new Node<K,V>(ph, pk, pv, hn);
2378	>	}
2379	>	setTabAt(nextTab, i, ln);
2380	>	setTabAt(nextTab, i + n, hn);
2381	>	setTabAt(tab, i, fwd);
2382	>	advance = true;
2383	>	}
2384	>	else if (f instanceof TreeBin) {
2385	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2386	>	TreeNode<K,V> lo = null, loTail = null;
2387	>	TreeNode<K,V> hi = null, hiTail = null;
2388	>	int lc = 0, hc = 0;
2389	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2390	>	int h = e.hash;
2391	>	TreeNode<K,V> p = new TreeNode<K,V>
2392	>	(h, e.key, e.val, null, null);
2393	>	if ((h & n) == 0) {
2394	>	if ((p.prev = loTail) == null)
2395	>	lo = p;
2396	>	else
2397	>	loTail.next = p;
2398	>	loTail = p;
2399	>	++lc;
2400	>	}
2401	>	else {
2402	>	if ((p.prev = hiTail) == null)
2403	>	hi = p;
2404	>	else
2405	>	hiTail.next = p;
2406	>	hiTail = p;
2407	>	++hc;
2408	>	}
2409	>	}
2410	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2411	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2412	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2413	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2414	>	setTabAt(nextTab, i, ln);
2415	>	setTabAt(nextTab, i + n, hn);
2416	>	setTabAt(tab, i, fwd);
2417	>	advance = true;
2418	>	}
2419	>	}
2420	>	}
2421	>	}
2422	>	}
2423		}
2424
2425	<	/* ---------------- Iterator Support -------------- */
2425	>	/* ---------------- Counter support -------------- */
2426
2427	<	abstract class HashIterator {
2428	<	int nextSegmentIndex;
2429	<	int nextTableIndex;
2430	<	HashEntry<K,V>[] currentTable;
2431	<	HashEntry<K, V> nextEntry;
2432	<	HashEntry<K, V> lastReturned;
2427	>	/**
2428	>	* A padded cell for distributing counts.  Adapted from LongAdder
2429	>	* and Striped64.  See their internal docs for explanation.
2430	>	*/
2431	>	@sun.misc.Contended static final class CounterCell {
2432	>	volatile long value;
2433	>	CounterCell(long x) { value = x; }
2434	>	}
2435
2436	<	HashIterator() {
2437	<	nextSegmentIndex = segments.length - 1;
2438	<	nextTableIndex = -1;
2439	<	advance();
2436	>	final long sumCount() {
2437	>	CounterCell[] as = counterCells; CounterCell a;
2438	>	long sum = baseCount;
2439	>	if (as != null) {
2440	>	for (int i = 0; i < as.length; ++i) {
2441	>	if ((a = as[i]) != null)
2442	>	sum += a.value;
2443	>	}
2444	>	}
2445	>	return sum;
2446	>	}
2447	>
2448	>	// See LongAdder version for explanation
2449	>	private final void fullAddCount(long x, boolean wasUncontended) {
2450	>	int h;
2451	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2452	>	ThreadLocalRandom.localInit();      // force initialization
2453	>	h = ThreadLocalRandom.getProbe();
2454	>	wasUncontended = true;
2455	>	}
2456	>	boolean collide = false;                // True if last slot nonempty
2457	>	for (;;) {
2458	>	CounterCell[] as; CounterCell a; int n; long v;
2459	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2460	>	if ((a = as[(n - 1) & h]) == null) {
2461	>	if (cellsBusy == 0) {            // Try to attach new Cell
2462	>	CounterCell r = new CounterCell(x); // Optimistic create
2463	>	if (cellsBusy == 0 &&
2464	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2465	>	boolean created = false;
2466	>	try {               // Recheck under lock
2467	>	CounterCell[] rs; int m, j;
2468	>	if ((rs = counterCells) != null &&
2469	>	(m = rs.length) > 0 &&
2470	>	rs[j = (m - 1) & h] == null) {
2471	>	rs[j] = r;
2472	>	created = true;
2473	>	}
2474	>	} finally {
2475	>	cellsBusy = 0;
2476	>	}
2477	>	if (created)
2478	>	break;
2479	>	continue;           // Slot is now non-empty
2480	>	}
2481	>	}
2482	>	collide = false;
2483	>	}
2484	>	else if (!wasUncontended)       // CAS already known to fail
2485	>	wasUncontended = true;      // Continue after rehash
2486	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2487	>	break;
2488	>	else if (counterCells != as || n >= NCPU)
2489	>	collide = false;            // At max size or stale
2490	>	else if (!collide)
2491	>	collide = true;
2492	>	else if (cellsBusy == 0 &&
2493	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2494	>	try {
2495	>	if (counterCells == as) {// Expand table unless stale
2496	>	CounterCell[] rs = new CounterCell[n << 1];
2497	>	for (int i = 0; i < n; ++i)
2498	>	rs[i] = as[i];
2499	>	counterCells = rs;
2500	>	}
2501	>	} finally {
2502	>	cellsBusy = 0;
2503	>	}
2504	>	collide = false;
2505	>	continue;                   // Retry with expanded table
2506	>	}
2507	>	h = ThreadLocalRandom.advanceProbe(h);
2508	>	}
2509	>	else if (cellsBusy == 0 && counterCells == as &&
2510	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2511	>	boolean init = false;
2512	>	try {                           // Initialize table
2513	>	if (counterCells == as) {
2514	>	CounterCell[] rs = new CounterCell[2];
2515	>	rs[h & 1] = new CounterCell(x);
2516	>	counterCells = rs;
2517	>	init = true;
2518	>	}
2519	>	} finally {
2520	>	cellsBusy = 0;
2521	>	}
2522	>	if (init)
2523	>	break;
2524	>	}
2525	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2526	>	break;                          // Fall back on using base
2527	>	}
2528	>	}
2529	>
2530	>	/* ---------------- Conversion from/to TreeBins -------------- */
2531	>
2532	>	/**
2533	>	* Replaces all linked nodes in bin at given index unless table is
2534	>	* too small, in which case resizes instead.
2535	>	*/
2536	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2537	>	Node<K,V> b; int n, sc;
2538	>	if (tab != null) {
2539	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY) {
2540	>	if (tab == table && (sc = sizeCtl) >= 0 &&
2541	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2542	>	transfer(tab, null);
2543	>	}
2544	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2545	>	synchronized (b) {
2546	>	if (tabAt(tab, index) == b) {
2547	>	TreeNode<K,V> hd = null, tl = null;
2548	>	for (Node<K,V> e = b; e != null; e = e.next) {
2549	>	TreeNode<K,V> p =
2550	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2551	>	null, null);
2552	>	if ((p.prev = tl) == null)
2553	>	hd = p;
2554	>	else
2555	>	tl.next = p;
2556	>	tl = p;
2557	>	}
2558	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2559	>	}
2560	>	}
2561	>	}
2562	>	}
2563	>	}
2564	>
2565	>	/**
2566	>	* Returns a list on non-TreeNodes replacing those in given list.
2567	>	*/
2568	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2569	>	Node<K,V> hd = null, tl = null;
2570	>	for (Node<K,V> q = b; q != null; q = q.next) {
2571	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2572	>	if (tl == null)
2573	>	hd = p;
2574	>	else
2575	>	tl.next = p;
2576	>	tl = p;
2577	>	}
2578	>	return hd;
2579	>	}
2580	>
2581	>	/* ---------------- TreeNodes -------------- */
2582	>
2583	>	/**
2584	>	* Nodes for use in TreeBins
2585	>	*/
2586	>	static final class TreeNode<K,V> extends Node<K,V> {
2587	>	TreeNode<K,V> parent;  // red-black tree links
2588	>	TreeNode<K,V> left;
2589	>	TreeNode<K,V> right;
2590	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2591	>	boolean red;
2592	>
2593	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2594	>	TreeNode<K,V> parent) {
2595	>	super(hash, key, val, next);
2596	>	this.parent = parent;
2597	>	}
2598	>
2599	>	Node<K,V> find(int h, Object k) {
2600	>	return findTreeNode(h, k, null);
2601		}
2602
2603		/**
2604	<	* Sets nextEntry to first node of next non-empty table
2605	<	* (in backwards order, to simplify checks).
2604	>	* Returns the TreeNode (or null if not found) for the given key
2605	>	* starting at given root.
2606		*/
2607	<	final void advance() {
2608	<	for (;;) {
2609	<	if (nextTableIndex >= 0) {
2610	<	if ((nextEntry = entryAt(currentTable,
2611	<	nextTableIndex--)) != null)
2607	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2608	>	if (k != null) {
2609	>	TreeNode<K,V> p = this;
2610	>	do  {
2611	>	int ph, dir; K pk; TreeNode<K,V> q;
2612	>	TreeNode<K,V> pl = p.left, pr = p.right;
2613	>	if ((ph = p.hash) > h)
2614	>	p = pl;
2615	>	else if (ph < h)
2616	>	p = pr;
2617	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2618	>	return p;
2619	>	else if (pl == null && pr == null)
2620		break;
2621	+	else if ((kc != null ||
2622	+	(kc = comparableClassFor(k)) != null) &&
2623	+	(dir = compareComparables(kc, k, pk)) != 0)
2624	+	p = (dir < 0) ? pl : pr;
2625	+	else if (pl == null)
2626	+	p = pr;
2627	+	else if (pr == null ||
2628	+	(q = pr.findTreeNode(h, k, kc)) == null)
2629	+	p = pl;
2630	+	else
2631	+	return q;
2632	+	} while (p != null);
2633	+	}
2634	+	return null;
2635	+	}
2636	+	}
2637	+
2638	+	/* ---------------- TreeBins -------------- */
2639	+
2640	+	/**
2641	+	* TreeNodes used at the heads of bins. TreeBins do not hold user
2642	+	* keys or values, but instead point to list of TreeNodes and
2643	+	* their root. They also maintain a parasitic read-write lock
2644	+	* forcing writers (who hold bin lock) to wait for readers (who do
2645	+	* not) to complete before tree restructuring operations.
2646	+	*/
2647	+	static final class TreeBin<K,V> extends Node<K,V> {
2648	+	TreeNode<K,V> root;
2649	+	volatile TreeNode<K,V> first;
2650	+	volatile Thread waiter;
2651	+	volatile int lockState;
2652	+	// values for lockState
2653	+	static final int WRITER = 1; // set while holding write lock
2654	+	static final int WAITER = 2; // set when waiting for write lock
2655	+	static final int READER = 4; // increment value for setting read lock
2656	+
2657	+	/**
2658	+	* Creates bin with initial set of nodes headed by b.
2659	+	*/
2660	+	TreeBin(TreeNode<K,V> b) {
2661	+	super(TREEBIN, null, null, null);
2662	+	this.first = b;
2663	+	TreeNode<K,V> r = null;
2664	+	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2665	+	next = (TreeNode<K,V>)x.next;
2666	+	x.left = x.right = null;
2667	+	if (r == null) {
2668	+	x.parent = null;
2669	+	x.red = false;
2670	+	r = x;
2671		}
2672	<	else if (nextSegmentIndex >= 0) {
2673	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2674	<	if (seg != null && (currentTable = seg.table) != null)
2675	<	nextTableIndex = currentTable.length - 1;
2672	>	else {
2673	>	Object key = x.key;
2674	>	int hash = x.hash;
2675	>	Class<?> kc = null;
2676	>	for (TreeNode<K,V> p = r;;) {
2677	>	int dir, ph;
2678	>	if ((ph = p.hash) > hash)
2679	>	dir = -1;
2680	>	else if (ph < hash)
2681	>	dir = 1;
2682	>	else if ((kc != null ||
2683	>	(kc = comparableClassFor(key)) != null))
2684	>	dir = compareComparables(kc, key, p.key);
2685	>	else
2686	>	dir = 0;
2687	>	TreeNode<K,V> xp = p;
2688	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2689	>	x.parent = xp;
2690	>	if (dir <= 0)
2691	>	xp.left = x;
2692	>	else
2693	>	xp.right = x;
2694	>	r = balanceInsertion(r, x);
2695	>	break;
2696	>	}
2697	>	}
2698		}
2699	<	else
2699	>	}
2700	>	this.root = r;
2701	>	}
2702	>
2703	>	/**
2704	>	* Acquires write lock for tree restructuring.
2705	>	*/
2706	>	private final void lockRoot() {
2707	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2708	>	contendedLock(); // offload to separate method
2709	>	}
2710	>
2711	>	/**
2712	>	* Releases write lock for tree restructuring.
2713	>	*/
2714	>	private final void unlockRoot() {
2715	>	lockState = 0;
2716	>	}
2717	>
2718	>	/**
2719	>	* Possibly blocks awaiting root lock.
2720	>	*/
2721	>	private final void contendedLock() {
2722	>	boolean waiting = false;
2723	>	for (int s;;) {
2724	>	if (((s = lockState) & WRITER) == 0) {
2725	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2726	>	if (waiting)
2727	>	waiter = null;
2728	>	return;
2729	>	}
2730	>	}
2731	>	else if ((s | WAITER) == 0) {
2732	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2733	>	waiting = true;
2734	>	waiter = Thread.currentThread();
2735	>	}
2736	>	}
2737	>	else if (waiting)
2738	>	LockSupport.park(this);
2739	>	}
2740	>	}
2741	>
2742	>	/**
2743	>	* Returns matching node or null if none. Tries to search
2744	>	* using tree comparisons from root, but continues linear
2745	>	* search when lock not available.
2746	>	*/
2747	>	final Node<K,V> find(int h, Object k) {
2748	>	if (k != null) {
2749	>	for (Node<K,V> e = first; e != null; e = e.next) {
2750	>	int s; K ek;
2751	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2752	>	if (e.hash == h &&
2753	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2754	>	return e;
2755	>	}
2756	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2757	>	s + READER)) {
2758	>	TreeNode<K,V> r, p;
2759	>	try {
2760	>	p = ((r = root) == null ? null :
2761	>	r.findTreeNode(h, k, null));
2762	>	} finally {
2763	>	Thread w;
2764	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2765	>	(READER|WAITER) && (w = waiter) != null)
2766	>	LockSupport.unpark(w);
2767	>	}
2768	>	return p;
2769	>	}
2770	>	}
2771	>	}
2772	>	return null;
2773	>	}
2774	>
2775	>	/**
2776	>	* Finds or adds a node.
2777	>	* @return null if added
2778	>	*/
2779	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2780	>	Class<?> kc = null;
2781	>	for (TreeNode<K,V> p = root;;) {
2782	>	int dir, ph; K pk; TreeNode<K,V> q, pr;
2783	>	if (p == null) {
2784	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2785	>	break;
2786	>	}
2787	>	else if ((ph = p.hash) > h)
2788	>	dir = -1;
2789	>	else if (ph < h)
2790	>	dir = 1;
2791	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2792	>	return p;
2793	>	else if ((kc == null &&
2794	>	(kc = comparableClassFor(k)) == null) ||
2795	>	(dir = compareComparables(kc, k, pk)) == 0) {
2796	>	if (p.left == null)
2797	>	dir = 1;
2798	>	else if ((pr = p.right) == null ||
2799	>	(q = pr.findTreeNode(h, k, kc)) == null)
2800	>	dir = -1;
2801	>	else
2802	>	return q;
2803	>	}
2804	>	TreeNode<K,V> xp = p;
2805	>	if ((p = (dir < 0) ? p.left : p.right) == null) {
2806	>	TreeNode<K,V> x, f = first;
2807	>	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2808	>	if (f != null)
2809	>	f.prev = x;
2810	>	if (dir < 0)
2811	>	xp.left = x;
2812	>	else
2813	>	xp.right = x;
2814	>	if (!xp.red)
2815	>	x.red = true;
2816	>	else {
2817	>	lockRoot();
2818	>	try {
2819	>	root = balanceInsertion(root, x);
2820	>	} finally {
2821	>	unlockRoot();
2822	>	}
2823	>	}
2824		break;
2825	+	}
2826		}
2827	+	assert checkInvariants(root);
2828	+	return null;
2829		}
2830
2831	<	final HashEntry<K,V> nextEntry() {
2832	<	HashEntry<K,V> e = nextEntry;
2833	<	if (e == null)
2834	<	throw new NoSuchElementException();
2835	<	lastReturned = e; // cannot assign until after null check
2836	<	if ((nextEntry = e.next) == null)
2837	<	advance();
2838	<	return e;
2831	>	/**
2832	>	* Removes the given node, that must be present before this
2833	>	* call.  This is messier than typical red-black deletion code
2834	>	* because we cannot swap the contents of an interior node
2835	>	* with a leaf successor that is pinned by "next" pointers
2836	>	* that are accessible independently of lock. So instead we
2837	>	* swap the tree linkages.
2838	>	*
2839	>	* @return true if now too small, so should be untreeified
2840	>	*/
2841	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2842	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2843	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2844	>	TreeNode<K,V> r, rl;
2845	>	if (pred == null)
2846	>	first = next;
2847	>	else
2848	>	pred.next = next;
2849	>	if (next != null)
2850	>	next.prev = pred;
2851	>	if (first == null) {
2852	>	root = null;
2853	>	return true;
2854	>	}
2855	>	if ((r = root) == null || r.right == null || // too small
2856	>	(rl = r.left) == null || rl.left == null)
2857	>	return true;
2858	>	lockRoot();
2859	>	try {
2860	>	TreeNode<K,V> replacement;
2861	>	TreeNode<K,V> pl = p.left;
2862	>	TreeNode<K,V> pr = p.right;
2863	>	if (pl != null && pr != null) {
2864	>	TreeNode<K,V> s = pr, sl;
2865	>	while ((sl = s.left) != null) // find successor
2866	>	s = sl;
2867	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2868	>	TreeNode<K,V> sr = s.right;
2869	>	TreeNode<K,V> pp = p.parent;
2870	>	if (s == pr) { // p was s's direct parent
2871	>	p.parent = s;
2872	>	s.right = p;
2873	>	}
2874	>	else {
2875	>	TreeNode<K,V> sp = s.parent;
2876	>	if ((p.parent = sp) != null) {
2877	>	if (s == sp.left)
2878	>	sp.left = p;
2879	>	else
2880	>	sp.right = p;
2881	>	}
2882	>	if ((s.right = pr) != null)
2883	>	pr.parent = s;
2884	>	}
2885	>	p.left = null;
2886	>	if ((p.right = sr) != null)
2887	>	sr.parent = p;
2888	>	if ((s.left = pl) != null)
2889	>	pl.parent = s;
2890	>	if ((s.parent = pp) == null)
2891	>	r = s;
2892	>	else if (p == pp.left)
2893	>	pp.left = s;
2894	>	else
2895	>	pp.right = s;
2896	>	if (sr != null)
2897	>	replacement = sr;
2898	>	else
2899	>	replacement = p;
2900	>	}
2901	>	else if (pl != null)
2902	>	replacement = pl;
2903	>	else if (pr != null)
2904	>	replacement = pr;
2905	>	else
2906	>	replacement = p;
2907	>	if (replacement != p) {
2908	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2909	>	if (pp == null)
2910	>	r = replacement;
2911	>	else if (p == pp.left)
2912	>	pp.left = replacement;
2913	>	else
2914	>	pp.right = replacement;
2915	>	p.left = p.right = p.parent = null;
2916	>	}
2917	>
2918	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2919	>
2920	>	if (p == replacement) {  // detach pointers
2921	>	TreeNode<K,V> pp;
2922	>	if ((pp = p.parent) != null) {
2923	>	if (p == pp.left)
2924	>	pp.left = null;
2925	>	else if (p == pp.right)
2926	>	pp.right = null;
2927	>	p.parent = null;
2928	>	}
2929	>	}
2930	>	} finally {
2931	>	unlockRoot();
2932	>	}
2933	>	assert checkInvariants(root);
2934	>	return false;
2935		}
2936
2937	<	public final boolean hasNext() { return nextEntry != null; }
2938	<	public final boolean hasMoreElements() { return nextEntry != null; }
2937	>	/* ------------------------------------------------------------ */
2938	>	// Red-black tree methods, all adapted from CLR
2939	>
2940	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2941	>	TreeNode<K,V> p) {
2942	>	TreeNode<K,V> r, pp, rl;
2943	>	if (p != null && (r = p.right) != null) {
2944	>	if ((rl = p.right = r.left) != null)
2945	>	rl.parent = p;
2946	>	if ((pp = r.parent = p.parent) == null)
2947	>	(root = r).red = false;
2948	>	else if (pp.left == p)
2949	>	pp.left = r;
2950	>	else
2951	>	pp.right = r;
2952	>	r.left = p;
2953	>	p.parent = r;
2954	>	}
2955	>	return root;
2956	>	}
2957	>
2958	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2959	>	TreeNode<K,V> p) {
2960	>	TreeNode<K,V> l, pp, lr;
2961	>	if (p != null && (l = p.left) != null) {
2962	>	if ((lr = p.left = l.right) != null)
2963	>	lr.parent = p;
2964	>	if ((pp = l.parent = p.parent) == null)
2965	>	(root = l).red = false;
2966	>	else if (pp.right == p)
2967	>	pp.right = l;
2968	>	else
2969	>	pp.left = l;
2970	>	l.right = p;
2971	>	p.parent = l;
2972	>	}
2973	>	return root;
2974	>	}
2975	>
2976	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2977	>	TreeNode<K,V> x) {
2978	>	x.red = true;
2979	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2980	>	if ((xp = x.parent) == null) {
2981	>	x.red = false;
2982	>	return x;
2983	>	}
2984	>	else if (!xp.red || (xpp = xp.parent) == null)
2985	>	return root;
2986	>	if (xp == (xppl = xpp.left)) {
2987	>	if ((xppr = xpp.right) != null && xppr.red) {
2988	>	xppr.red = false;
2989	>	xp.red = false;
2990	>	xpp.red = true;
2991	>	x = xpp;
2992	>	}
2993	>	else {
2994	>	if (x == xp.right) {
2995	>	root = rotateLeft(root, x = xp);
2996	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2997	>	}
2998	>	if (xp != null) {
2999	>	xp.red = false;
3000	>	if (xpp != null) {
3001	>	xpp.red = true;
3002	>	root = rotateRight(root, xpp);
3003	>	}
3004	>	}
3005	>	}
3006	>	}
3007	>	else {
3008	>	if (xppl != null && xppl.red) {
3009	>	xppl.red = false;
3010	>	xp.red = false;
3011	>	xpp.red = true;
3012	>	x = xpp;
3013	>	}
3014	>	else {
3015	>	if (x == xp.left) {
3016	>	root = rotateRight(root, x = xp);
3017	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3018	>	}
3019	>	if (xp != null) {
3020	>	xp.red = false;
3021	>	if (xpp != null) {
3022	>	xpp.red = true;
3023	>	root = rotateLeft(root, xpp);
3024	>	}
3025	>	}
3026	>	}
3027	>	}
3028	>	}
3029	>	}
3030	>
3031	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3032	>	TreeNode<K,V> x) {
3033	>	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3034	>	if (x == null || x == root)
3035	>	return root;
3036	>	else if ((xp = x.parent) == null) {
3037	>	x.red = false;
3038	>	return x;
3039	>	}
3040	>	else if (x.red) {
3041	>	x.red = false;
3042	>	return root;
3043	>	}
3044	>	else if ((xpl = xp.left) == x) {
3045	>	if ((xpr = xp.right) != null && xpr.red) {
3046	>	xpr.red = false;
3047	>	xp.red = true;
3048	>	root = rotateLeft(root, xp);
3049	>	xpr = (xp = x.parent) == null ? null : xp.right;
3050	>	}
3051	>	if (xpr == null)
3052	>	x = xp;
3053	>	else {
3054	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3055	>	if ((sr == null || !sr.red) &&
3056	>	(sl == null || !sl.red)) {
3057	>	xpr.red = true;
3058	>	x = xp;
3059	>	}
3060	>	else {
3061	>	if (sr == null || !sr.red) {
3062	>	if (sl != null)
3063	>	sl.red = false;
3064	>	xpr.red = true;
3065	>	root = rotateRight(root, xpr);
3066	>	xpr = (xp = x.parent) == null ?
3067	>	null : xp.right;
3068	>	}
3069	>	if (xpr != null) {
3070	>	xpr.red = (xp == null) ? false : xp.red;
3071	>	if ((sr = xpr.right) != null)
3072	>	sr.red = false;
3073	>	}
3074	>	if (xp != null) {
3075	>	xp.red = false;
3076	>	root = rotateLeft(root, xp);
3077	>	}
3078	>	x = root;
3079	>	}
3080	>	}
3081	>	}
3082	>	else { // symmetric
3083	>	if (xpl != null && xpl.red) {
3084	>	xpl.red = false;
3085	>	xp.red = true;
3086	>	root = rotateRight(root, xp);
3087	>	xpl = (xp = x.parent) == null ? null : xp.left;
3088	>	}
3089	>	if (xpl == null)
3090	>	x = xp;
3091	>	else {
3092	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3093	>	if ((sl == null || !sl.red) &&
3094	>	(sr == null || !sr.red)) {
3095	>	xpl.red = true;
3096	>	x = xp;
3097	>	}
3098	>	else {
3099	>	if (sl == null || !sl.red) {
3100	>	if (sr != null)
3101	>	sr.red = false;
3102	>	xpl.red = true;
3103	>	root = rotateLeft(root, xpl);
3104	>	xpl = (xp = x.parent) == null ?
3105	>	null : xp.left;
3106	>	}
3107	>	if (xpl != null) {
3108	>	xpl.red = (xp == null) ? false : xp.red;
3109	>	if ((sl = xpl.left) != null)
3110	>	sl.red = false;
3111	>	}
3112	>	if (xp != null) {
3113	>	xp.red = false;
3114	>	root = rotateRight(root, xp);
3115	>	}
3116	>	x = root;
3117	>	}
3118	>	}
3119	>	}
3120	>	}
3121	>	}
3122	>
3123	>	/**
3124	>	* Recursive invariant check
3125	>	*/
3126	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3127	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3128	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3129	>	if (tb != null && tb.next != t)
3130	>	return false;
3131	>	if (tn != null && tn.prev != t)
3132	>	return false;
3133	>	if (tp != null && t != tp.left && t != tp.right)
3134	>	return false;
3135	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3136	>	return false;
3137	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3138	>	return false;
3139	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3140	>	return false;
3141	>	if (tl != null && !checkInvariants(tl))
3142	>	return false;
3143	>	if (tr != null && !checkInvariants(tr))
3144	>	return false;
3145	>	return true;
3146	>	}
3147	>
3148	>	private static final sun.misc.Unsafe U;
3149	>	private static final long LOCKSTATE;
3150	>	static {
3151	>	try {
3152	>	U = sun.misc.Unsafe.getUnsafe();
3153	>	Class<?> k = TreeBin.class;
3154	>	LOCKSTATE = U.objectFieldOffset
3155	>	(k.getDeclaredField("lockState"));
3156	>	} catch (Exception e) {
3157	>	throw new Error(e);
3158	>	}
3159	>	}
3160	>	}
3161	>
3162	>	/* ----------------Table Traversal -------------- */
3163	>
3164	>	/**
3165	>	* Encapsulates traversal for methods such as containsValue; also
3166	>	* serves as a base class for other iterators and spliterators.
3167	>	*
3168	>	* Method advance visits once each still-valid node that was
3169	>	* reachable upon iterator construction. It might miss some that
3170	>	* were added to a bin after the bin was visited, which is OK wrt
3171	>	* consistency guarantees. Maintaining this property in the face
3172	>	* of possible ongoing resizes requires a fair amount of
3173	>	* bookkeeping state that is difficult to optimize away amidst
3174	>	* volatile accesses.  Even so, traversal maintains reasonable
3175	>	* throughput.
3176	>	*
3177	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3178	>	* However, if the table has been resized, then all future steps
3179	>	* must traverse both the bin at the current index as well as at
3180	>	* (index + baseSize); and so on for further resizings. To
3181	>	* paranoically cope with potential sharing by users of iterators
3182	>	* across threads, iteration terminates if a bounds checks fails
3183	>	* for a table read.
3184	>	*/
3185	>	static class Traverser<K,V> {
3186	>	Node<K,V>[] tab;        // current table; updated if resized
3187	>	Node<K,V> next;         // the next entry to use
3188	>	int index;              // index of bin to use next
3189	>	int baseIndex;          // current index of initial table
3190	>	int baseLimit;          // index bound for initial table
3191	>	final int baseSize;     // initial table size
3192	>
3193	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3194	>	this.tab = tab;
3195	>	this.baseSize = size;
3196	>	this.baseIndex = this.index = index;
3197	>	this.baseLimit = limit;
3198	>	this.next = null;
3199	>	}
3200	>
3201	>	/**
3202	>	* Advances if possible, returning next valid node, or null if none.
3203	>	*/
3204	>	final Node<K,V> advance() {
3205	>	Node<K,V> e;
3206	>	if ((e = next) != null)
3207	>	e = e.next;
3208	>	for (;;) {
3209	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3210	>	if (e != null)
3211	>	return next = e;
3212	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3213	>	(n = t.length) <= (i = index) || i < 0)
3214	>	return next = null;
3215	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
3216	>	if (e instanceof ForwardingNode) {
3217	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3218	>	e = null;
3219	>	continue;
3220	>	}
3221	>	else if (e instanceof TreeBin)
3222	>	e = ((TreeBin<K,V>)e).first;
3223	>	else
3224	>	e = null;
3225	>	}
3226	>	if ((index += baseSize) >= n)
3227	>	index = ++baseIndex;    // visit upper slots if present
3228	>	}
3229	>	}
3230	>	}
3231	>
3232	>	/**
3233	>	* Base of key, value, and entry Iterators. Adds fields to
3234	>	* Traverser to support iterator.remove.
3235	>	*/
3236	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3237	>	final ConcurrentHashMap<K,V> map;
3238	>	Node<K,V> lastReturned;
3239	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3240	>	ConcurrentHashMap<K,V> map) {
3241	>	super(tab, size, index, limit);
3242	>	this.map = map;
3243	>	advance();
3244	>	}
3245	>
3246	>	public final boolean hasNext() { return next != null; }
3247	>	public final boolean hasMoreElements() { return next != null; }
3248
3249		public final void remove() {
3250	<	if (lastReturned == null)
3250	>	Node<K,V> p;
3251	>	if ((p = lastReturned) == null)
3252		throw new IllegalStateException();
1263	–	ConcurrentHashMap.this.remove(lastReturned.key);
3253		lastReturned = null;
3254	+	map.replaceNode(p.key, null, null);
3255		}
3256		}
3257
3258	<	final class KeyIterator
3259	<	extends HashIterator
3260	<	implements Iterator<K>, Enumeration<K>
3261	<	{
3262	<	public final K next()        { return super.nextEntry().key; }
3263	<	public final K nextElement() { return super.nextEntry().key; }
3264	<	}
3265	<
3266	<	final class ValueIterator
3267	<	extends HashIterator
3268	<	implements Iterator<V>, Enumeration<V>
3269	<	{
3270	<	public final V next()        { return super.nextEntry().value; }
3271	<	public final V nextElement() { return super.nextEntry().value; }
3258	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3259	>	implements Iterator<K>, Enumeration<K> {
3260	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3261	>	ConcurrentHashMap<K,V> map) {
3262	>	super(tab, index, size, limit, map);
3263	>	}
3264	>
3265	>	public final K next() {
3266	>	Node<K,V> p;
3267	>	if ((p = next) == null)
3268	>	throw new NoSuchElementException();
3269	>	K k = p.key;
3270	>	lastReturned = p;
3271	>	advance();
3272	>	return k;
3273	>	}
3274	>
3275	>	public final K nextElement() { return next(); }
3276	>	}
3277	>
3278	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3279	>	implements Iterator<V>, Enumeration<V> {
3280	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3281	>	ConcurrentHashMap<K,V> map) {
3282	>	super(tab, index, size, limit, map);
3283	>	}
3284	>
3285	>	public final V next() {
3286	>	Node<K,V> p;
3287	>	if ((p = next) == null)
3288	>	throw new NoSuchElementException();
3289	>	V v = p.val;
3290	>	lastReturned = p;
3291	>	advance();
3292	>	return v;
3293	>	}
3294	>
3295	>	public final V nextElement() { return next(); }
3296	>	}
3297	>
3298	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3299	>	implements Iterator<Map.Entry<K,V>> {
3300	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3301	>	ConcurrentHashMap<K,V> map) {
3302	>	super(tab, index, size, limit, map);
3303	>	}
3304	>
3305	>	public final Map.Entry<K,V> next() {
3306	>	Node<K,V> p;
3307	>	if ((p = next) == null)
3308	>	throw new NoSuchElementException();
3309	>	K k = p.key;
3310	>	V v = p.val;
3311	>	lastReturned = p;
3312	>	advance();
3313	>	return new MapEntry<K,V>(k, v, map);
3314	>	}
3315		}
3316
3317		/**
3318	<	* Custom Entry class used by EntryIterator.next(), that relays
3319	<	* setValue changes to the underlying map.
3320	<	*/
3321	<	final class WriteThroughEntry
3322	<	extends AbstractMap.SimpleEntry<K,V>
3323	<	{
3324	<	WriteThroughEntry(K k, V v) {
3325	<	super(k,v);
3318	>	* Exported Entry for EntryIterator
3319	>	*/
3320	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3321	>	final K key; // non-null
3322	>	V val;       // non-null
3323	>	final ConcurrentHashMap<K,V> map;
3324	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3325	>	this.key = key;
3326	>	this.val = val;
3327	>	this.map = map;
3328	>	}
3329	>	public K getKey()        { return key; }
3330	>	public V getValue()      { return val; }
3331	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3332	>	public String toString() { return key + "=" + val; }
3333	>
3334	>	public boolean equals(Object o) {
3335	>	Object k, v; Map.Entry<?,?> e;
3336	>	return ((o instanceof Map.Entry) &&
3337	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3338	>	(v = e.getValue()) != null &&
3339	>	(k == key || k.equals(key)) &&
3340	>	(v == val || v.equals(val)));
3341		}
3342
3343		/**
3344		* Sets our entry's value and writes through to the map. The
3345	<	* value to return is somewhat arbitrary here. Since a
3346	<	* WriteThroughEntry does not necessarily track asynchronous
3347	<	* changes, the most recent "previous" value could be
3348	<	* different from what we return (or could even have been
3349	<	* removed in which case the put will re-establish). We do not
1302	<	* and cannot guarantee more.
3345	>	* value to return is somewhat arbitrary here. Since we do not
3346	>	* necessarily track asynchronous changes, the most recent
3347	>	* "previous" value could be different from what we return (or
3348	>	* could even have been removed, in which case the put will
3349	>	* re-establish). We do not and cannot guarantee more.
3350		*/
3351		public V setValue(V value) {
3352		if (value == null) throw new NullPointerException();
3353	<	V v = super.setValue(value);
3354	<	ConcurrentHashMap.this.put(getKey(), value);
3353	>	V v = val;
3354	>	val = value;
3355	>	map.put(key, value);
3356		return v;
3357		}
3358		}
3359
3360	<	final class EntryIterator
3361	<	extends HashIterator
3362	<	implements Iterator<Entry<K,V>>
3363	<	{
3364	<	public Map.Entry<K,V> next() {
3365	<	HashEntry<K,V> e = super.nextEntry();
3366	<	return new WriteThroughEntry(e.key, e.value);
3360	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3361	>	implements Spliterator<K> {
3362	>	long est;               // size estimate
3363	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3364	>	long est) {
3365	>	super(tab, size, index, limit);
3366	>	this.est = est;
3367	>	}
3368	>
3369	>	public Spliterator<K> trySplit() {
3370	>	int i, f, h;
3371	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3372	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3373	>	f, est >>>= 1);
3374	>	}
3375	>
3376	>	public void forEachRemaining(Consumer<? super K> action) {
3377	>	if (action == null) throw new NullPointerException();
3378	>	for (Node<K,V> p; (p = advance()) != null;)
3379	>	action.accept(p.key);
3380	>	}
3381	>
3382	>	public boolean tryAdvance(Consumer<? super K> action) {
3383	>	if (action == null) throw new NullPointerException();
3384	>	Node<K,V> p;
3385	>	if ((p = advance()) == null)
3386	>	return false;
3387	>	action.accept(p.key);
3388	>	return true;
3389	>	}
3390	>
3391	>	public long estimateSize() { return est; }
3392	>
3393	>	public int characteristics() {
3394	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3395	>	Spliterator.NONNULL;
3396		}
3397		}
3398
3399	<	final class KeySet extends AbstractSet<K> {
3400	<	public Iterator<K> iterator() {
3401	<	return new KeyIterator();
3399	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3400	>	implements Spliterator<V> {
3401	>	long est;               // size estimate
3402	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3403	>	long est) {
3404	>	super(tab, size, index, limit);
3405	>	this.est = est;
3406		}
3407	<	public int size() {
3408	<	return ConcurrentHashMap.this.size();
3407	>
3408	>	public Spliterator<V> trySplit() {
3409	>	int i, f, h;
3410	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3411	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3412	>	f, est >>>= 1);
3413		}
3414	<	public boolean isEmpty() {
3415	<	return ConcurrentHashMap.this.isEmpty();
3414	>
3415	>	public void forEachRemaining(Consumer<? super V> action) {
3416	>	if (action == null) throw new NullPointerException();
3417	>	for (Node<K,V> p; (p = advance()) != null;)
3418	>	action.accept(p.val);
3419		}
3420	<	public boolean contains(Object o) {
3421	<	return ConcurrentHashMap.this.containsKey(o);
3420	>
3421	>	public boolean tryAdvance(Consumer<? super V> action) {
3422	>	if (action == null) throw new NullPointerException();
3423	>	Node<K,V> p;
3424	>	if ((p = advance()) == null)
3425	>	return false;
3426	>	action.accept(p.val);
3427	>	return true;
3428		}
3429	<	public boolean remove(Object o) {
3430	<	return ConcurrentHashMap.this.remove(o) != null;
3429	>
3430	>	public long estimateSize() { return est; }
3431	>
3432	>	public int characteristics() {
3433	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3434	>	}
3435	>	}
3436	>
3437	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3438	>	implements Spliterator<Map.Entry<K,V>> {
3439	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3440	>	long est;               // size estimate
3441	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3442	>	long est, ConcurrentHashMap<K,V> map) {
3443	>	super(tab, size, index, limit);
3444	>	this.map = map;
3445	>	this.est = est;
3446	>	}
3447	>
3448	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3449	>	int i, f, h;
3450	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3451	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3452	>	f, est >>>= 1, map);
3453		}
3454	<	public void clear() {
3455	<	ConcurrentHashMap.this.clear();
3454	>
3455	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3456	>	if (action == null) throw new NullPointerException();
3457	>	for (Node<K,V> p; (p = advance()) != null; )
3458	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3459	>	}
3460	>
3461	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3462	>	if (action == null) throw new NullPointerException();
3463	>	Node<K,V> p;
3464	>	if ((p = advance()) == null)
3465	>	return false;
3466	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3467	>	return true;
3468		}
3469	+
3470	+	public long estimateSize() { return est; }
3471	+
3472	+	public int characteristics() {
3473	+	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3474	+	Spliterator.NONNULL;
3475	+	}
3476	+	}
3477	+
3478	+	// Parallel bulk operations
3479	+
3480	+	/**
3481	+	* Computes initial batch value for bulk tasks. The returned value
3482	+	* is approximately exp2 of the number of times (minus one) to
3483	+	* split task by two before executing leaf action. This value is
3484	+	* faster to compute and more convenient to use as a guide to
3485	+	* splitting than is the depth, since it is used while dividing by
3486	+	* two anyway.
3487	+	*/
3488	+	final int batchFor(long b) {
3489	+	long n;
3490	+	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3491	+	return 0;
3492	+	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3493	+	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3494	+	}
3495	+
3496	+	/**
3497	+	* Performs the given action for each (key, value).
3498	+	*
3499	+	* @param parallelismThreshold the (estimated) number of elements
3500	+	* needed for this operation to be executed in parallel
3501	+	* @param action the action
3502	+	* @since 1.8
3503	+	*/
3504	+	public void forEach(long parallelismThreshold,
3505	+	BiConsumer<? super K,? super V> action) {
3506	+	if (action == null) throw new NullPointerException();
3507	+	new ForEachMappingTask<K,V>
3508	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3509	+	action).invoke();
3510	+	}
3511	+
3512	+	/**
3513	+	* Performs the given action for each non-null transformation
3514	+	* of each (key, value).
3515	+	*
3516	+	* @param parallelismThreshold the (estimated) number of elements
3517	+	* needed for this operation to be executed in parallel
3518	+	* @param transformer a function returning the transformation
3519	+	* for an element, or null if there is no transformation (in
3520	+	* which case the action is not applied)
3521	+	* @param action the action
3522	+	* @param <U> the return type of the transformer
3523	+	* @since 1.8
3524	+	*/
3525	+	public <U> void forEach(long parallelismThreshold,
3526	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3527	+	Consumer<? super U> action) {
3528	+	if (transformer == null || action == null)
3529	+	throw new NullPointerException();
3530	+	new ForEachTransformedMappingTask<K,V,U>
3531	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3532	+	transformer, action).invoke();
3533	+	}
3534	+
3535	+	/**
3536	+	* Returns a non-null result from applying the given search
3537	+	* function on each (key, value), or null if none.  Upon
3538	+	* success, further element processing is suppressed and the
3539	+	* results of any other parallel invocations of the search
3540	+	* function are ignored.
3541	+	*
3542	+	* @param parallelismThreshold the (estimated) number of elements
3543	+	* needed for this operation to be executed in parallel
3544	+	* @param searchFunction a function returning a non-null
3545	+	* result on success, else null
3546	+	* @param <U> the return type of the search function
3547	+	* @return a non-null result from applying the given search
3548	+	* function on each (key, value), or null if none
3549	+	* @since 1.8
3550	+	*/
3551	+	public <U> U search(long parallelismThreshold,
3552	+	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3553	+	if (searchFunction == null) throw new NullPointerException();
3554	+	return new SearchMappingsTask<K,V,U>
3555	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3556	+	searchFunction, new AtomicReference<U>()).invoke();
3557	+	}
3558	+
3559	+	/**
3560	+	* Returns the result of accumulating the given transformation
3561	+	* of all (key, value) pairs using the given reducer to
3562	+	* combine values, or null if none.
3563	+	*
3564	+	* @param parallelismThreshold the (estimated) number of elements
3565	+	* needed for this operation to be executed in parallel
3566	+	* @param transformer a function returning the transformation
3567	+	* for an element, or null if there is no transformation (in
3568	+	* which case it is not combined)
3569	+	* @param reducer a commutative associative combining function
3570	+	* @param <U> the return type of the transformer
3571	+	* @return the result of accumulating the given transformation
3572	+	* of all (key, value) pairs
3573	+	* @since 1.8
3574	+	*/
3575	+	public <U> U reduce(long parallelismThreshold,
3576	+	BiFunction<? super K, ? super V, ? extends U> transformer,
3577	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3578	+	if (transformer == null || reducer == null)
3579	+	throw new NullPointerException();
3580	+	return new MapReduceMappingsTask<K,V,U>
3581	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3582	+	null, transformer, reducer).invoke();
3583	+	}
3584	+
3585	+	/**
3586	+	* Returns the result of accumulating the given transformation
3587	+	* of all (key, value) pairs using the given reducer to
3588	+	* combine values, and the given basis as an identity value.
3589	+	*
3590	+	* @param parallelismThreshold the (estimated) number of elements
3591	+	* needed for this operation to be executed in parallel
3592	+	* @param transformer a function returning the transformation
3593	+	* for an element
3594	+	* @param basis the identity (initial default value) for the reduction
3595	+	* @param reducer a commutative associative combining function
3596	+	* @return the result of accumulating the given transformation
3597	+	* of all (key, value) pairs
3598	+	* @since 1.8
3599	+	*/
3600	+	public double reduceToDouble(long parallelismThreshold,
3601	+	ToDoubleBiFunction<? super K, ? super V> transformer,
3602	+	double basis,
3603	+	DoubleBinaryOperator reducer) {
3604	+	if (transformer == null || reducer == null)
3605	+	throw new NullPointerException();
3606	+	return new MapReduceMappingsToDoubleTask<K,V>
3607	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3608	+	null, transformer, basis, reducer).invoke();
3609	+	}
3610	+
3611	+	/**
3612	+	* Returns the result of accumulating the given transformation
3613	+	* of all (key, value) pairs using the given reducer to
3614	+	* combine values, and the given basis as an identity value.
3615	+	*
3616	+	* @param parallelismThreshold the (estimated) number of elements
3617	+	* needed for this operation to be executed in parallel
3618	+	* @param transformer a function returning the transformation
3619	+	* for an element
3620	+	* @param basis the identity (initial default value) for the reduction
3621	+	* @param reducer a commutative associative combining function
3622	+	* @return the result of accumulating the given transformation
3623	+	* of all (key, value) pairs
3624	+	* @since 1.8
3625	+	*/
3626	+	public long reduceToLong(long parallelismThreshold,
3627	+	ToLongBiFunction<? super K, ? super V> transformer,
3628	+	long basis,
3629	+	LongBinaryOperator reducer) {
3630	+	if (transformer == null || reducer == null)
3631	+	throw new NullPointerException();
3632	+	return new MapReduceMappingsToLongTask<K,V>
3633	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3634	+	null, transformer, basis, reducer).invoke();
3635	+	}
3636	+
3637	+	/**
3638	+	* Returns the result of accumulating the given transformation
3639	+	* of all (key, value) pairs using the given reducer to
3640	+	* combine values, and the given basis as an identity value.
3641	+	*
3642	+	* @param parallelismThreshold the (estimated) number of elements
3643	+	* needed for this operation to be executed in parallel
3644	+	* @param transformer a function returning the transformation
3645	+	* for an element
3646	+	* @param basis the identity (initial default value) for the reduction
3647	+	* @param reducer a commutative associative combining function
3648	+	* @return the result of accumulating the given transformation
3649	+	* of all (key, value) pairs
3650	+	* @since 1.8
3651	+	*/
3652	+	public int reduceToInt(long parallelismThreshold,
3653	+	ToIntBiFunction<? super K, ? super V> transformer,
3654	+	int basis,
3655	+	IntBinaryOperator reducer) {
3656	+	if (transformer == null || reducer == null)
3657	+	throw new NullPointerException();
3658	+	return new MapReduceMappingsToIntTask<K,V>
3659	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3660	+	null, transformer, basis, reducer).invoke();
3661	+	}
3662	+
3663	+	/**
3664	+	* Performs the given action for each key.
3665	+	*
3666	+	* @param parallelismThreshold the (estimated) number of elements
3667	+	* needed for this operation to be executed in parallel
3668	+	* @param action the action
3669	+	* @since 1.8
3670	+	*/
3671	+	public void forEachKey(long parallelismThreshold,
3672	+	Consumer<? super K> action) {
3673	+	if (action == null) throw new NullPointerException();
3674	+	new ForEachKeyTask<K,V>
3675	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3676	+	action).invoke();
3677	+	}
3678	+
3679	+	/**
3680	+	* Performs the given action for each non-null transformation
3681	+	* of each key.
3682	+	*
3683	+	* @param parallelismThreshold the (estimated) number of elements
3684	+	* needed for this operation to be executed in parallel
3685	+	* @param transformer a function returning the transformation
3686	+	* for an element, or null if there is no transformation (in
3687	+	* which case the action is not applied)
3688	+	* @param action the action
3689	+	* @param <U> the return type of the transformer
3690	+	* @since 1.8
3691	+	*/
3692	+	public <U> void forEachKey(long parallelismThreshold,
3693	+	Function<? super K, ? extends U> transformer,
3694	+	Consumer<? super U> action) {
3695	+	if (transformer == null || action == null)
3696	+	throw new NullPointerException();
3697	+	new ForEachTransformedKeyTask<K,V,U>
3698	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3699	+	transformer, action).invoke();
3700	+	}
3701	+
3702	+	/**
3703	+	* Returns a non-null result from applying the given search
3704	+	* function on each key, or null if none. Upon success,
3705	+	* further element processing is suppressed and the results of
3706	+	* any other parallel invocations of the search function are
3707	+	* ignored.
3708	+	*
3709	+	* @param parallelismThreshold the (estimated) number of elements
3710	+	* needed for this operation to be executed in parallel
3711	+	* @param searchFunction a function returning a non-null
3712	+	* result on success, else null
3713	+	* @param <U> the return type of the search function
3714	+	* @return a non-null result from applying the given search
3715	+	* function on each key, or null if none
3716	+	* @since 1.8
3717	+	*/
3718	+	public <U> U searchKeys(long parallelismThreshold,
3719	+	Function<? super K, ? extends U> searchFunction) {
3720	+	if (searchFunction == null) throw new NullPointerException();
3721	+	return new SearchKeysTask<K,V,U>
3722	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3723	+	searchFunction, new AtomicReference<U>()).invoke();
3724	+	}
3725	+
3726	+	/**
3727	+	* Returns the result of accumulating all keys using the given
3728	+	* reducer to combine values, or null if none.
3729	+	*
3730	+	* @param parallelismThreshold the (estimated) number of elements
3731	+	* needed for this operation to be executed in parallel
3732	+	* @param reducer a commutative associative combining function
3733	+	* @return the result of accumulating all keys using the given
3734	+	* reducer to combine values, or null if none
3735	+	* @since 1.8
3736	+	*/
3737	+	public K reduceKeys(long parallelismThreshold,
3738	+	BiFunction<? super K, ? super K, ? extends K> reducer) {
3739	+	if (reducer == null) throw new NullPointerException();
3740	+	return new ReduceKeysTask<K,V>
3741	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3742	+	null, reducer).invoke();
3743	+	}
3744	+
3745	+	/**
3746	+	* Returns the result of accumulating the given transformation
3747	+	* of all keys using the given reducer to combine values, or
3748	+	* null if none.
3749	+	*
3750	+	* @param parallelismThreshold the (estimated) number of elements
3751	+	* needed for this operation to be executed in parallel
3752	+	* @param transformer a function returning the transformation
3753	+	* for an element, or null if there is no transformation (in
3754	+	* which case it is not combined)
3755	+	* @param reducer a commutative associative combining function
3756	+	* @param <U> the return type of the transformer
3757	+	* @return the result of accumulating the given transformation
3758	+	* of all keys
3759	+	* @since 1.8
3760	+	*/
3761	+	public <U> U reduceKeys(long parallelismThreshold,
3762	+	Function<? super K, ? extends U> transformer,
3763	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3764	+	if (transformer == null || reducer == null)
3765	+	throw new NullPointerException();
3766	+	return new MapReduceKeysTask<K,V,U>
3767	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3768	+	null, transformer, reducer).invoke();
3769	+	}
3770	+
3771	+	/**
3772	+	* Returns the result of accumulating the given transformation
3773	+	* of all keys using the given reducer to combine values, and
3774	+	* the given basis as an identity value.
3775	+	*
3776	+	* @param parallelismThreshold the (estimated) number of elements
3777	+	* needed for this operation to be executed in parallel
3778	+	* @param transformer a function returning the transformation
3779	+	* for an element
3780	+	* @param basis the identity (initial default value) for the reduction
3781	+	* @param reducer a commutative associative combining function
3782	+	* @return the result of accumulating the given transformation
3783	+	* of all keys
3784	+	* @since 1.8
3785	+	*/
3786	+	public double reduceKeysToDouble(long parallelismThreshold,
3787	+	ToDoubleFunction<? super K> transformer,
3788	+	double basis,
3789	+	DoubleBinaryOperator reducer) {
3790	+	if (transformer == null || reducer == null)
3791	+	throw new NullPointerException();
3792	+	return new MapReduceKeysToDoubleTask<K,V>
3793	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3794	+	null, transformer, basis, reducer).invoke();
3795	+	}
3796	+
3797	+	/**
3798	+	* Returns the result of accumulating the given transformation
3799	+	* of all keys using the given reducer to combine values, and
3800	+	* the given basis as an identity value.
3801	+	*
3802	+	* @param parallelismThreshold the (estimated) number of elements
3803	+	* needed for this operation to be executed in parallel
3804	+	* @param transformer a function returning the transformation
3805	+	* for an element
3806	+	* @param basis the identity (initial default value) for the reduction
3807	+	* @param reducer a commutative associative combining function
3808	+	* @return the result of accumulating the given transformation
3809	+	* of all keys
3810	+	* @since 1.8
3811	+	*/
3812	+	public long reduceKeysToLong(long parallelismThreshold,
3813	+	ToLongFunction<? super K> transformer,
3814	+	long basis,
3815	+	LongBinaryOperator reducer) {
3816	+	if (transformer == null || reducer == null)
3817	+	throw new NullPointerException();
3818	+	return new MapReduceKeysToLongTask<K,V>
3819	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3820	+	null, transformer, basis, reducer).invoke();
3821	+	}
3822	+
3823	+	/**
3824	+	* Returns the result of accumulating the given transformation
3825	+	* of all keys using the given reducer to combine values, and
3826	+	* the given basis as an identity value.
3827	+	*
3828	+	* @param parallelismThreshold the (estimated) number of elements
3829	+	* needed for this operation to be executed in parallel
3830	+	* @param transformer a function returning the transformation
3831	+	* for an element
3832	+	* @param basis the identity (initial default value) for the reduction
3833	+	* @param reducer a commutative associative combining function
3834	+	* @return the result of accumulating the given transformation
3835	+	* of all keys
3836	+	* @since 1.8
3837	+	*/
3838	+	public int reduceKeysToInt(long parallelismThreshold,
3839	+	ToIntFunction<? super K> transformer,
3840	+	int basis,
3841	+	IntBinaryOperator reducer) {
3842	+	if (transformer == null || reducer == null)
3843	+	throw new NullPointerException();
3844	+	return new MapReduceKeysToIntTask<K,V>
3845	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3846	+	null, transformer, basis, reducer).invoke();
3847	+	}
3848	+
3849	+	/**
3850	+	* Performs the given action for each value.
3851	+	*
3852	+	* @param parallelismThreshold the (estimated) number of elements
3853	+	* needed for this operation to be executed in parallel
3854	+	* @param action the action
3855	+	* @since 1.8
3856	+	*/
3857	+	public void forEachValue(long parallelismThreshold,
3858	+	Consumer<? super V> action) {
3859	+	if (action == null)
3860	+	throw new NullPointerException();
3861	+	new ForEachValueTask<K,V>
3862	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3863	+	action).invoke();
3864	+	}
3865	+
3866	+	/**
3867	+	* Performs the given action for each non-null transformation
3868	+	* of each value.
3869	+	*
3870	+	* @param parallelismThreshold the (estimated) number of elements
3871	+	* needed for this operation to be executed in parallel
3872	+	* @param transformer a function returning the transformation
3873	+	* for an element, or null if there is no transformation (in
3874	+	* which case the action is not applied)
3875	+	* @param action the action
3876	+	* @param <U> the return type of the transformer
3877	+	* @since 1.8
3878	+	*/
3879	+	public <U> void forEachValue(long parallelismThreshold,
3880	+	Function<? super V, ? extends U> transformer,
3881	+	Consumer<? super U> action) {
3882	+	if (transformer == null || action == null)
3883	+	throw new NullPointerException();
3884	+	new ForEachTransformedValueTask<K,V,U>
3885	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3886	+	transformer, action).invoke();
3887	+	}
3888	+
3889	+	/**
3890	+	* Returns a non-null result from applying the given search
3891	+	* function on each value, or null if none.  Upon success,
3892	+	* further element processing is suppressed and the results of
3893	+	* any other parallel invocations of the search function are
3894	+	* ignored.
3895	+	*
3896	+	* @param parallelismThreshold the (estimated) number of elements
3897	+	* needed for this operation to be executed in parallel
3898	+	* @param searchFunction a function returning a non-null
3899	+	* result on success, else null
3900	+	* @param <U> the return type of the search function
3901	+	* @return a non-null result from applying the given search
3902	+	* function on each value, or null if none
3903	+	* @since 1.8
3904	+	*/
3905	+	public <U> U searchValues(long parallelismThreshold,
3906	+	Function<? super V, ? extends U> searchFunction) {
3907	+	if (searchFunction == null) throw new NullPointerException();
3908	+	return new SearchValuesTask<K,V,U>
3909	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3910	+	searchFunction, new AtomicReference<U>()).invoke();
3911	+	}
3912	+
3913	+	/**
3914	+	* Returns the result of accumulating all values using the
3915	+	* given reducer to combine values, or null if none.
3916	+	*
3917	+	* @param parallelismThreshold the (estimated) number of elements
3918	+	* needed for this operation to be executed in parallel
3919	+	* @param reducer a commutative associative combining function
3920	+	* @return the result of accumulating all values
3921	+	* @since 1.8
3922	+	*/
3923	+	public V reduceValues(long parallelismThreshold,
3924	+	BiFunction<? super V, ? super V, ? extends V> reducer) {
3925	+	if (reducer == null) throw new NullPointerException();
3926	+	return new ReduceValuesTask<K,V>
3927	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3928	+	null, reducer).invoke();
3929	+	}
3930	+
3931	+	/**
3932	+	* Returns the result of accumulating the given transformation
3933	+	* of all values using the given reducer to combine values, or
3934	+	* null if none.
3935	+	*
3936	+	* @param parallelismThreshold the (estimated) number of elements
3937	+	* needed for this operation to be executed in parallel
3938	+	* @param transformer a function returning the transformation
3939	+	* for an element, or null if there is no transformation (in
3940	+	* which case it is not combined)
3941	+	* @param reducer a commutative associative combining function
3942	+	* @param <U> the return type of the transformer
3943	+	* @return the result of accumulating the given transformation
3944	+	* of all values
3945	+	* @since 1.8
3946	+	*/
3947	+	public <U> U reduceValues(long parallelismThreshold,
3948	+	Function<? super V, ? extends U> transformer,
3949	+	BiFunction<? super U, ? super U, ? extends U> reducer) {
3950	+	if (transformer == null || reducer == null)
3951	+	throw new NullPointerException();
3952	+	return new MapReduceValuesTask<K,V,U>
3953	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3954	+	null, transformer, reducer).invoke();
3955	+	}
3956	+
3957	+	/**
3958	+	* Returns the result of accumulating the given transformation
3959	+	* of all values using the given reducer to combine values,
3960	+	* and the given basis as an identity value.
3961	+	*
3962	+	* @param parallelismThreshold the (estimated) number of elements
3963	+	* needed for this operation to be executed in parallel
3964	+	* @param transformer a function returning the transformation
3965	+	* for an element
3966	+	* @param basis the identity (initial default value) for the reduction
3967	+	* @param reducer a commutative associative combining function
3968	+	* @return the result of accumulating the given transformation
3969	+	* of all values
3970	+	* @since 1.8
3971	+	*/
3972	+	public double reduceValuesToDouble(long parallelismThreshold,
3973	+	ToDoubleFunction<? super V> transformer,
3974	+	double basis,
3975	+	DoubleBinaryOperator reducer) {
3976	+	if (transformer == null || reducer == null)
3977	+	throw new NullPointerException();
3978	+	return new MapReduceValuesToDoubleTask<K,V>
3979	+	(null, batchFor(parallelismThreshold), 0, 0, table,
3980	+	null, transformer, basis, reducer).invoke();
3981	+	}
3982	+
3983	+	/**
3984	+	* Returns the result of accumulating the given transformation
3985	+	* of all values using the given reducer to combine values,
3986	+	* and the given basis as an identity value.
3987	+	*
3988	+	* @param parallelismThreshold the (estimated) number of elements
3989	+	* needed for this operation to be executed in parallel
3990	+	* @param transformer a function returning the transformation
3991	+	* for an element
3992	+	* @param basis the identity (initial default value) for the reduction
3993	+	* @param reducer a commutative associative combining function
3994	+	* @return the result of accumulating the given transformation
3995	+	* of all values
3996	+	* @since 1.8
3997	+	*/
3998	+	public long reduceValuesToLong(long parallelismThreshold,
3999	+	ToLongFunction<? super V> transformer,
4000	+	long basis,
4001	+	LongBinaryOperator reducer) {
4002	+	if (transformer == null || reducer == null)
4003	+	throw new NullPointerException();
4004	+	return new MapReduceValuesToLongTask<K,V>
4005	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4006	+	null, transformer, basis, reducer).invoke();
4007	+	}
4008	+
4009	+	/**
4010	+	* Returns the result of accumulating the given transformation
4011	+	* of all values using the given reducer to combine values,
4012	+	* and the given basis as an identity value.
4013	+	*
4014	+	* @param parallelismThreshold the (estimated) number of elements
4015	+	* needed for this operation to be executed in parallel
4016	+	* @param transformer a function returning the transformation
4017	+	* for an element
4018	+	* @param basis the identity (initial default value) for the reduction
4019	+	* @param reducer a commutative associative combining function
4020	+	* @return the result of accumulating the given transformation
4021	+	* of all values
4022	+	* @since 1.8
4023	+	*/
4024	+	public int reduceValuesToInt(long parallelismThreshold,
4025	+	ToIntFunction<? super V> transformer,
4026	+	int basis,
4027	+	IntBinaryOperator reducer) {
4028	+	if (transformer == null || reducer == null)
4029	+	throw new NullPointerException();
4030	+	return new MapReduceValuesToIntTask<K,V>
4031	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4032	+	null, transformer, basis, reducer).invoke();
4033	+	}
4034	+
4035	+	/**
4036	+	* Performs the given action for each entry.
4037	+	*
4038	+	* @param parallelismThreshold the (estimated) number of elements
4039	+	* needed for this operation to be executed in parallel
4040	+	* @param action the action
4041	+	* @since 1.8
4042	+	*/
4043	+	public void forEachEntry(long parallelismThreshold,
4044	+	Consumer<? super Map.Entry<K,V>> action) {
4045	+	if (action == null) throw new NullPointerException();
4046	+	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4047	+	action).invoke();
4048	+	}
4049	+
4050	+	/**
4051	+	* Performs the given action for each non-null transformation
4052	+	* of each entry.
4053	+	*
4054	+	* @param parallelismThreshold the (estimated) number of elements
4055	+	* needed for this operation to be executed in parallel
4056	+	* @param transformer a function returning the transformation
4057	+	* for an element, or null if there is no transformation (in
4058	+	* which case the action is not applied)
4059	+	* @param action the action
4060	+	* @param <U> the return type of the transformer
4061	+	* @since 1.8
4062	+	*/
4063	+	public <U> void forEachEntry(long parallelismThreshold,
4064	+	Function<Map.Entry<K,V>, ? extends U> transformer,
4065	+	Consumer<? super U> action) {
4066	+	if (transformer == null || action == null)
4067	+	throw new NullPointerException();
4068	+	new ForEachTransformedEntryTask<K,V,U>
4069	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4070	+	transformer, action).invoke();
4071	+	}
4072	+
4073	+	/**
4074	+	* Returns a non-null result from applying the given search
4075	+	* function on each entry, or null if none.  Upon success,
4076	+	* further element processing is suppressed and the results of
4077	+	* any other parallel invocations of the search function are
4078	+	* ignored.
4079	+	*
4080	+	* @param parallelismThreshold the (estimated) number of elements
4081	+	* needed for this operation to be executed in parallel
4082	+	* @param searchFunction a function returning a non-null
4083	+	* result on success, else null
4084	+	* @param <U> the return type of the search function
4085	+	* @return a non-null result from applying the given search
4086	+	* function on each entry, or null if none
4087	+	* @since 1.8
4088	+	*/
4089	+	public <U> U searchEntries(long parallelismThreshold,
4090	+	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4091	+	if (searchFunction == null) throw new NullPointerException();
4092	+	return new SearchEntriesTask<K,V,U>
4093	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4094	+	searchFunction, new AtomicReference<U>()).invoke();
4095	+	}
4096	+
4097	+	/**
4098	+	* Returns the result of accumulating all entries using the
4099	+	* given reducer to combine values, or null if none.
4100	+	*
4101	+	* @param parallelismThreshold the (estimated) number of elements
4102	+	* needed for this operation to be executed in parallel
4103	+	* @param reducer a commutative associative combining function
4104	+	* @return the result of accumulating all entries
4105	+	* @since 1.8
4106	+	*/
4107	+	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4108	+	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4109	+	if (reducer == null) throw new NullPointerException();
4110	+	return new ReduceEntriesTask<K,V>
4111	+	(null, batchFor(parallelismThreshold), 0, 0, table,
4112	+	null, reducer).invoke();
4113		}
4114
4115	<	final class Values extends AbstractCollection<V> {
4116	<	public Iterator<V> iterator() {
4117	<	return new ValueIterator();
4115	>	/**
4116	>	* Returns the result of accumulating the given transformation
4117	>	* of all entries using the given reducer to combine values,
4118	>	* or null if none.
4119	>	*
4120	>	* @param parallelismThreshold the (estimated) number of elements
4121	>	* needed for this operation to be executed in parallel
4122	>	* @param transformer a function returning the transformation
4123	>	* for an element, or null if there is no transformation (in
4124	>	* which case it is not combined)
4125	>	* @param reducer a commutative associative combining function
4126	>	* @param <U> the return type of the transformer
4127	>	* @return the result of accumulating the given transformation
4128	>	* of all entries
4129	>	* @since 1.8
4130	>	*/
4131	>	public <U> U reduceEntries(long parallelismThreshold,
4132	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4133	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4134	>	if (transformer == null || reducer == null)
4135	>	throw new NullPointerException();
4136	>	return new MapReduceEntriesTask<K,V,U>
4137	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4138	>	null, transformer, reducer).invoke();
4139	>	}
4140	>
4141	>	/**
4142	>	* Returns the result of accumulating the given transformation
4143	>	* of all entries using the given reducer to combine values,
4144	>	* and the given basis as an identity value.
4145	>	*
4146	>	* @param parallelismThreshold the (estimated) number of elements
4147	>	* needed for this operation to be executed in parallel
4148	>	* @param transformer a function returning the transformation
4149	>	* for an element
4150	>	* @param basis the identity (initial default value) for the reduction
4151	>	* @param reducer a commutative associative combining function
4152	>	* @return the result of accumulating the given transformation
4153	>	* of all entries
4154	>	* @since 1.8
4155	>	*/
4156	>	public double reduceEntriesToDouble(long parallelismThreshold,
4157	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4158	>	double basis,
4159	>	DoubleBinaryOperator reducer) {
4160	>	if (transformer == null || reducer == null)
4161	>	throw new NullPointerException();
4162	>	return new MapReduceEntriesToDoubleTask<K,V>
4163	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4164	>	null, transformer, basis, reducer).invoke();
4165	>	}
4166	>
4167	>	/**
4168	>	* Returns the result of accumulating the given transformation
4169	>	* of all entries using the given reducer to combine values,
4170	>	* and the given basis as an identity value.
4171	>	*
4172	>	* @param parallelismThreshold the (estimated) number of elements
4173	>	* needed for this operation to be executed in parallel
4174	>	* @param transformer a function returning the transformation
4175	>	* for an element
4176	>	* @param basis the identity (initial default value) for the reduction
4177	>	* @param reducer a commutative associative combining function
4178	>	* @return the result of accumulating the given transformation
4179	>	* of all entries
4180	>	* @since 1.8
4181	>	*/
4182	>	public long reduceEntriesToLong(long parallelismThreshold,
4183	>	ToLongFunction<Map.Entry<K,V>> transformer,
4184	>	long basis,
4185	>	LongBinaryOperator reducer) {
4186	>	if (transformer == null || reducer == null)
4187	>	throw new NullPointerException();
4188	>	return new MapReduceEntriesToLongTask<K,V>
4189	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4190	>	null, transformer, basis, reducer).invoke();
4191	>	}
4192	>
4193	>	/**
4194	>	* Returns the result of accumulating the given transformation
4195	>	* of all entries using the given reducer to combine values,
4196	>	* and the given basis as an identity value.
4197	>	*
4198	>	* @param parallelismThreshold the (estimated) number of elements
4199	>	* needed for this operation to be executed in parallel
4200	>	* @param transformer a function returning the transformation
4201	>	* for an element
4202	>	* @param basis the identity (initial default value) for the reduction
4203	>	* @param reducer a commutative associative combining function
4204	>	* @return the result of accumulating the given transformation
4205	>	* of all entries
4206	>	* @since 1.8
4207	>	*/
4208	>	public int reduceEntriesToInt(long parallelismThreshold,
4209	>	ToIntFunction<Map.Entry<K,V>> transformer,
4210	>	int basis,
4211	>	IntBinaryOperator reducer) {
4212	>	if (transformer == null || reducer == null)
4213	>	throw new NullPointerException();
4214	>	return new MapReduceEntriesToIntTask<K,V>
4215	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4216	>	null, transformer, basis, reducer).invoke();
4217	>	}
4218	>
4219	>
4220	>	/* ----------------Views -------------- */
4221	>
4222	>	/**
4223	>	* Base class for views.
4224	>	*/
4225	>	abstract static class CollectionView<K,V,E>
4226	>	implements Collection<E>, java.io.Serializable {
4227	>	private static final long serialVersionUID = 7249069246763182397L;
4228	>	final ConcurrentHashMap<K,V> map;
4229	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4230	>
4231	>	/**
4232	>	* Returns the map backing this view.
4233	>	*
4234	>	* @return the map backing this view
4235	>	*/
4236	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4237	>
4238	>	/**
4239	>	* Removes all of the elements from this view, by removing all
4240	>	* the mappings from the map backing this view.
4241	>	*/
4242	>	public final void clear()      { map.clear(); }
4243	>	public final int size()        { return map.size(); }
4244	>	public final boolean isEmpty() { return map.isEmpty(); }
4245	>
4246	>	// implementations below rely on concrete classes supplying these
4247	>	// abstract methods
4248	>	/**
4249	>	* Returns a "weakly consistent" iterator that will never
4250	>	* throw {@link ConcurrentModificationException}, and
4251	>	* guarantees to traverse elements as they existed upon
4252	>	* construction of the iterator, and may (but is not
4253	>	* guaranteed to) reflect any modifications subsequent to
4254	>	* construction.
4255	>	*/
4256	>	public abstract Iterator<E> iterator();
4257	>	public abstract boolean contains(Object o);
4258	>	public abstract boolean remove(Object o);
4259	>
4260	>	private static final String oomeMsg = "Required array size too large";
4261	>
4262	>	public final Object[] toArray() {
4263	>	long sz = map.mappingCount();
4264	>	if (sz > MAX_ARRAY_SIZE)
4265	>	throw new OutOfMemoryError(oomeMsg);
4266	>	int n = (int)sz;
4267	>	Object[] r = new Object[n];
4268	>	int i = 0;
4269	>	for (E e : this) {
4270	>	if (i == n) {
4271	>	if (n >= MAX_ARRAY_SIZE)
4272	>	throw new OutOfMemoryError(oomeMsg);
4273	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4274	>	n = MAX_ARRAY_SIZE;
4275	>	else
4276	>	n += (n >>> 1) + 1;
4277	>	r = Arrays.copyOf(r, n);
4278	>	}
4279	>	r[i++] = e;
4280	>	}
4281	>	return (i == n) ? r : Arrays.copyOf(r, i);
4282	>	}
4283	>
4284	>	@SuppressWarnings("unchecked")
4285	>	public final <T> T[] toArray(T[] a) {
4286	>	long sz = map.mappingCount();
4287	>	if (sz > MAX_ARRAY_SIZE)
4288	>	throw new OutOfMemoryError(oomeMsg);
4289	>	int m = (int)sz;
4290	>	T[] r = (a.length >= m) ? a :
4291	>	(T[])java.lang.reflect.Array
4292	>	.newInstance(a.getClass().getComponentType(), m);
4293	>	int n = r.length;
4294	>	int i = 0;
4295	>	for (E e : this) {
4296	>	if (i == n) {
4297	>	if (n >= MAX_ARRAY_SIZE)
4298	>	throw new OutOfMemoryError(oomeMsg);
4299	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4300	>	n = MAX_ARRAY_SIZE;
4301	>	else
4302	>	n += (n >>> 1) + 1;
4303	>	r = Arrays.copyOf(r, n);
4304	>	}
4305	>	r[i++] = (T)e;
4306	>	}
4307	>	if (a == r && i < n) {
4308	>	r[i] = null; // null-terminate
4309	>	return r;
4310	>	}
4311	>	return (i == n) ? r : Arrays.copyOf(r, i);
4312		}
4313	<	public int size() {
4314	<	return ConcurrentHashMap.this.size();
4313	>
4314	>	/**
4315	>	* Returns a string representation of this collection.
4316	>	* The string representation consists of the string representations
4317	>	* of the collection's elements in the order they are returned by
4318	>	* its iterator, enclosed in square brackets ({@code "[]"}).
4319	>	* Adjacent elements are separated by the characters {@code ", "}
4320	>	* (comma and space).  Elements are converted to strings as by
4321	>	* {@link String#valueOf(Object)}.
4322	>	*
4323	>	* @return a string representation of this collection
4324	>	*/
4325	>	public final String toString() {
4326	>	StringBuilder sb = new StringBuilder();
4327	>	sb.append('[');
4328	>	Iterator<E> it = iterator();
4329	>	if (it.hasNext()) {
4330	>	for (;;) {
4331	>	Object e = it.next();
4332	>	sb.append(e == this ? "(this Collection)" : e);
4333	>	if (!it.hasNext())
4334	>	break;
4335	>	sb.append(',').append(' ');
4336	>	}
4337	>	}
4338	>	return sb.append(']').toString();
4339		}
4340	<	public boolean isEmpty() {
4341	<	return ConcurrentHashMap.this.isEmpty();
4340	>
4341	>	public final boolean containsAll(Collection<?> c) {
4342	>	if (c != this) {
4343	>	for (Object e : c) {
4344	>	if (e == null || !contains(e))
4345	>	return false;
4346	>	}
4347	>	}
4348	>	return true;
4349		}
4350	<	public boolean contains(Object o) {
4351	<	return ConcurrentHashMap.this.containsValue(o);
4350	>
4351	>	public final boolean removeAll(Collection<?> c) {
4352	>	boolean modified = false;
4353	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4354	>	if (c.contains(it.next())) {
4355	>	it.remove();
4356	>	modified = true;
4357	>	}
4358	>	}
4359	>	return modified;
4360	>	}
4361	>
4362	>	public final boolean retainAll(Collection<?> c) {
4363	>	boolean modified = false;
4364	>	for (Iterator<E> it = iterator(); it.hasNext();) {
4365	>	if (!c.contains(it.next())) {
4366	>	it.remove();
4367	>	modified = true;
4368	>	}
4369	>	}
4370	>	return modified;
4371		}
4372	<	public void clear() {
4373	<	ConcurrentHashMap.this.clear();
4372	>
4373	>	}
4374	>
4375	>	/**
4376	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4377	>	* which additions may optionally be enabled by mapping to a
4378	>	* common value.  This class cannot be directly instantiated.
4379	>	* See {@link #keySet() keySet()},
4380	>	* {@link #keySet(Object) keySet(V)},
4381	>	* {@link #newKeySet() newKeySet()},
4382	>	* {@link #newKeySet(int) newKeySet(int)}.
4383	>	*
4384	>	* @since 1.8
4385	>	*/
4386	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4387	>	implements Set<K>, java.io.Serializable {
4388	>	private static final long serialVersionUID = 7249069246763182397L;
4389	>	private final V value;
4390	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4391	>	super(map);
4392	>	this.value = value;
4393	>	}
4394	>
4395	>	/**
4396	>	* Returns the default mapped value for additions,
4397	>	* or {@code null} if additions are not supported.
4398	>	*
4399	>	* @return the default mapped value for additions, or {@code null}
4400	>	* if not supported
4401	>	*/
4402	>	public V getMappedValue() { return value; }
4403	>
4404	>	/**
4405	>	* {@inheritDoc}
4406	>	* @throws NullPointerException if the specified key is null
4407	>	*/
4408	>	public boolean contains(Object o) { return map.containsKey(o); }
4409	>
4410	>	/**
4411	>	* Removes the key from this map view, by removing the key (and its
4412	>	* corresponding value) from the backing map.  This method does
4413	>	* nothing if the key is not in the map.
4414	>	*
4415	>	* @param  o the key to be removed from the backing map
4416	>	* @return {@code true} if the backing map contained the specified key
4417	>	* @throws NullPointerException if the specified key is null
4418	>	*/
4419	>	public boolean remove(Object o) { return map.remove(o) != null; }
4420	>
4421	>	/**
4422	>	* @return an iterator over the keys of the backing map
4423	>	*/
4424	>	public Iterator<K> iterator() {
4425	>	Node<K,V>[] t;
4426	>	ConcurrentHashMap<K,V> m = map;
4427	>	int f = (t = m.table) == null ? 0 : t.length;
4428	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4429	>	}
4430	>
4431	>	/**
4432	>	* Adds the specified key to this set view by mapping the key to
4433	>	* the default mapped value in the backing map, if defined.
4434	>	*
4435	>	* @param e key to be added
4436	>	* @return {@code true} if this set changed as a result of the call
4437	>	* @throws NullPointerException if the specified key is null
4438	>	* @throws UnsupportedOperationException if no default mapped value
4439	>	* for additions was provided
4440	>	*/
4441	>	public boolean add(K e) {
4442	>	V v;
4443	>	if ((v = value) == null)
4444	>	throw new UnsupportedOperationException();
4445	>	return map.putVal(e, v, true) == null;
4446	>	}
4447	>
4448	>	/**
4449	>	* Adds all of the elements in the specified collection to this set,
4450	>	* as if by calling {@link #add} on each one.
4451	>	*
4452	>	* @param c the elements to be inserted into this set
4453	>	* @return {@code true} if this set changed as a result of the call
4454	>	* @throws NullPointerException if the collection or any of its
4455	>	* elements are {@code null}
4456	>	* @throws UnsupportedOperationException if no default mapped value
4457	>	* for additions was provided
4458	>	*/
4459	>	public boolean addAll(Collection<? extends K> c) {
4460	>	boolean added = false;
4461	>	V v;
4462	>	if ((v = value) == null)
4463	>	throw new UnsupportedOperationException();
4464	>	for (K e : c) {
4465	>	if (map.putVal(e, v, true) == null)
4466	>	added = true;
4467	>	}
4468	>	return added;
4469	>	}
4470	>
4471	>	public int hashCode() {
4472	>	int h = 0;
4473	>	for (K e : this)
4474	>	h += e.hashCode();
4475	>	return h;
4476	>	}
4477	>
4478	>	public boolean equals(Object o) {
4479	>	Set<?> c;
4480	>	return ((o instanceof Set) &&
4481	>	((c = (Set<?>)o) == this ||
4482	>	(containsAll(c) && c.containsAll(this))));
4483	>	}
4484	>
4485	>	public Spliterator<K> spliterator() {
4486	>	Node<K,V>[] t;
4487	>	ConcurrentHashMap<K,V> m = map;
4488	>	long n = m.sumCount();
4489	>	int f = (t = m.table) == null ? 0 : t.length;
4490	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4491	>	}
4492	>
4493	>	public void forEach(Consumer<? super K> action) {
4494	>	if (action == null) throw new NullPointerException();
4495	>	Node<K,V>[] t;
4496	>	if ((t = map.table) != null) {
4497	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4498	>	for (Node<K,V> p; (p = it.advance()) != null; )
4499	>	action.accept(p.key);
4500	>	}
4501		}
4502		}
4503
4504	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4505	<	public Iterator<Map.Entry<K,V>> iterator() {
4506	<	return new EntryIterator();
4504	>	/**
4505	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4506	>	* values, in which additions are disabled. This class cannot be
4507	>	* directly instantiated. See {@link #values()}.
4508	>	*/
4509	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4510	>	implements Collection<V>, java.io.Serializable {
4511	>	private static final long serialVersionUID = 2249069246763182397L;
4512	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4513	>	public final boolean contains(Object o) {
4514	>	return map.containsValue(o);
4515	>	}
4516	>
4517	>	public final boolean remove(Object o) {
4518	>	if (o != null) {
4519	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4520	>	if (o.equals(it.next())) {
4521	>	it.remove();
4522	>	return true;
4523	>	}
4524	>	}
4525	>	}
4526	>	return false;
4527		}
4528	+
4529	+	public final Iterator<V> iterator() {
4530	+	ConcurrentHashMap<K,V> m = map;
4531	+	Node<K,V>[] t;
4532	+	int f = (t = m.table) == null ? 0 : t.length;
4533	+	return new ValueIterator<K,V>(t, f, 0, f, m);
4534	+	}
4535	+
4536	+	public final boolean add(V e) {
4537	+	throw new UnsupportedOperationException();
4538	+	}
4539	+	public final boolean addAll(Collection<? extends V> c) {
4540	+	throw new UnsupportedOperationException();
4541	+	}
4542	+
4543	+	public Spliterator<V> spliterator() {
4544	+	Node<K,V>[] t;
4545	+	ConcurrentHashMap<K,V> m = map;
4546	+	long n = m.sumCount();
4547	+	int f = (t = m.table) == null ? 0 : t.length;
4548	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4549	+	}
4550	+
4551	+	public void forEach(Consumer<? super V> action) {
4552	+	if (action == null) throw new NullPointerException();
4553	+	Node<K,V>[] t;
4554	+	if ((t = map.table) != null) {
4555	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4556	+	for (Node<K,V> p; (p = it.advance()) != null; )
4557	+	action.accept(p.val);
4558	+	}
4559	+	}
4560	+	}
4561	+
4562	+	/**
4563	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4564	+	* entries.  This class cannot be directly instantiated. See
4565	+	* {@link #entrySet()}.
4566	+	*/
4567	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4568	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4569	+	private static final long serialVersionUID = 2249069246763182397L;
4570	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4571	+
4572		public boolean contains(Object o) {
4573	<	if (!(o instanceof Map.Entry))
4574	<	return false;
4575	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4576	<	V v = ConcurrentHashMap.this.get(e.getKey());
4577	<	return v != null && v.equals(e.getValue());
4573	>	Object k, v, r; Map.Entry<?,?> e;
4574	>	return ((o instanceof Map.Entry) &&
4575	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4576	>	(r = map.get(k)) != null &&
4577	>	(v = e.getValue()) != null &&
4578	>	(v == r || v.equals(r)));
4579		}
4580	+
4581		public boolean remove(Object o) {
4582	<	if (!(o instanceof Map.Entry))
4583	<	return false;
4584	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4585	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4582	>	Object k, v; Map.Entry<?,?> e;
4583	>	return ((o instanceof Map.Entry) &&
4584	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4585	>	(v = e.getValue()) != null &&
4586	>	map.remove(k, v));
4587	>	}
4588	>
4589	>	/**
4590	>	* @return an iterator over the entries of the backing map
4591	>	*/
4592	>	public Iterator<Map.Entry<K,V>> iterator() {
4593	>	ConcurrentHashMap<K,V> m = map;
4594	>	Node<K,V>[] t;
4595	>	int f = (t = m.table) == null ? 0 : t.length;
4596	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4597	>	}
4598	>
4599	>	public boolean add(Entry<K,V> e) {
4600	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4601		}
4602	<	public int size() {
4603	<	return ConcurrentHashMap.this.size();
4602	>
4603	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4604	>	boolean added = false;
4605	>	for (Entry<K,V> e : c) {
4606	>	if (add(e))
4607	>	added = true;
4608	>	}
4609	>	return added;
4610		}
4611	<	public boolean isEmpty() {
4612	<	return ConcurrentHashMap.this.isEmpty();
4611	>
4612	>	public final int hashCode() {
4613	>	int h = 0;
4614	>	Node<K,V>[] t;
4615	>	if ((t = map.table) != null) {
4616	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4617	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4618	>	h += p.hashCode();
4619	>	}
4620	>	}
4621	>	return h;
4622		}
4623	<	public void clear() {
4624	<	ConcurrentHashMap.this.clear();
4623	>
4624	>	public final boolean equals(Object o) {
4625	>	Set<?> c;
4626	>	return ((o instanceof Set) &&
4627	>	((c = (Set<?>)o) == this ||
4628	>	(containsAll(c) && c.containsAll(this))));
4629	>	}
4630	>
4631	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4632	>	Node<K,V>[] t;
4633	>	ConcurrentHashMap<K,V> m = map;
4634	>	long n = m.sumCount();
4635	>	int f = (t = m.table) == null ? 0 : t.length;
4636	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4637	>	}
4638	>
4639	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4640	>	if (action == null) throw new NullPointerException();
4641	>	Node<K,V>[] t;
4642	>	if ((t = map.table) != null) {
4643	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4644	>	for (Node<K,V> p; (p = it.advance()) != null; )
4645	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4646	>	}
4647		}
4648	+
4649		}
4650
4651	<	/* ---------------- Serialization Support -------------- */
4651	>	// -------------------------------------------------------
4652
4653		/**
4654	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4655	<	* stream (i.e., serializes it).
1394	<	* @param s the stream
1395	<	* @serialData
1396	<	* the key (Object) and value (Object)
1397	<	* for each key-value mapping, followed by a null pair.
1398	<	* The key-value mappings are emitted in no particular order.
4654	>	* Base class for bulk tasks. Repeats some fields and code from
4655	>	* class Traverser, because we need to subclass CountedCompleter.
4656		*/
4657	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4658	<	// force all segments for serialization compatibility
4659	<	for (int k = 0; k < segments.length; ++k)
4660	<	ensureSegment(k);
4661	<	s.defaultWriteObject();
4662	<
4663	<	final Segment<K,V>[] segments = this.segments;
4664	<	for (int k = 0; k < segments.length; ++k) {
4665	<	Segment<K,V> seg = segmentAt(segments, k);
4666	<	seg.lock();
4667	<	try {
4668	<	HashEntry<K,V>[] tab = seg.table;
4669	<	for (int i = 0; i < tab.length; ++i) {
4670	<	HashEntry<K,V> e;
4671	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4672	<	s.writeObject(e.key);
4673	<	s.writeObject(e.value);
4657	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4658	>	Node<K,V>[] tab;        // same as Traverser
4659	>	Node<K,V> next;
4660	>	int index;
4661	>	int baseIndex;
4662	>	int baseLimit;
4663	>	final int baseSize;
4664	>	int batch;              // split control
4665	>
4666	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4667	>	super(par);
4668	>	this.batch = b;
4669	>	this.index = this.baseIndex = i;
4670	>	if ((this.tab = t) == null)
4671	>	this.baseSize = this.baseLimit = 0;
4672	>	else if (par == null)
4673	>	this.baseSize = this.baseLimit = t.length;
4674	>	else {
4675	>	this.baseLimit = f;
4676	>	this.baseSize = par.baseSize;
4677	>	}
4678	>	}
4679	>
4680	>	/**
4681	>	* Same as Traverser version
4682	>	*/
4683	>	final Node<K,V> advance() {
4684	>	Node<K,V> e;
4685	>	if ((e = next) != null)
4686	>	e = e.next;
4687	>	for (;;) {
4688	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4689	>	if (e != null)
4690	>	return next = e;
4691	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4692	>	(n = t.length) <= (i = index) || i < 0)
4693	>	return next = null;
4694	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4695	>	if (e instanceof ForwardingNode) {
4696	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4697	>	e = null;
4698	>	continue;
4699		}
4700	+	else if (e instanceof TreeBin)
4701	+	e = ((TreeBin<K,V>)e).first;
4702	+	else
4703	+	e = null;
4704		}
4705	<	} finally {
4706	<	seg.unlock();
4705	>	if ((index += baseSize) >= n)
4706	>	index = ++baseIndex;    // visit upper slots if present
4707		}
4708		}
1423	–	s.writeObject(null);
1424	–	s.writeObject(null);
4709		}
4710
4711	<	/**
4712	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4713	<	* stream (i.e., deserializes it).
4714	<	* @param s the stream
4715	<	*/
4716	<	@SuppressWarnings("unchecked")
4717	<	private void readObject(java.io.ObjectInputStream s)
4718	<	throws IOException, ClassNotFoundException {
4719	<	s.defaultReadObject();
4711	>	/*
4712	>	* Task classes. Coded in a regular but ugly format/style to
4713	>	* simplify checks that each variant differs in the right way from
4714	>	* others. The null screenings exist because compilers cannot tell
4715	>	* that we've already null-checked task arguments, so we force
4716	>	* simplest hoisted bypass to help avoid convoluted traps.
4717	>	*/
4718	>	@SuppressWarnings("serial")
4719	>	static final class ForEachKeyTask<K,V>
4720	>	extends BulkTask<K,V,Void> {
4721	>	final Consumer<? super K> action;
4722	>	ForEachKeyTask
4723	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4724	>	Consumer<? super K> action) {
4725	>	super(p, b, i, f, t);
4726	>	this.action = action;
4727	>	}
4728	>	public final void compute() {
4729	>	final Consumer<? super K> action;
4730	>	if ((action = this.action) != null) {
4731	>	for (int i = baseIndex, f, h; batch > 0 &&
4732	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4733	>	addToPendingCount(1);
4734	>	new ForEachKeyTask<K,V>
4735	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4736	>	action).fork();
4737	>	}
4738	>	for (Node<K,V> p; (p = advance()) != null;)
4739	>	action.accept(p.key);
4740	>	propagateCompletion();
4741	>	}
4742	>	}
4743	>	}
4744
4745	<	// Re-initialize segments to be minimally sized, and let grow.
4746	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4747	<	final Segment<K,V>[] segments = this.segments;
4748	<	for (int k = 0; k < segments.length; ++k) {
4749	<	Segment<K,V> seg = segments[k];
4750	<	if (seg != null) {
4751	<	seg.threshold = (int)(cap * seg.loadFactor);
4752	<	seg.table = (HashEntry<K,V>[]) new HashEntry<?,?>[cap];
4745	>	@SuppressWarnings("serial")
4746	>	static final class ForEachValueTask<K,V>
4747	>	extends BulkTask<K,V,Void> {
4748	>	final Consumer<? super V> action;
4749	>	ForEachValueTask
4750	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4751	>	Consumer<? super V> action) {
4752	>	super(p, b, i, f, t);
4753	>	this.action = action;
4754	>	}
4755	>	public final void compute() {
4756	>	final Consumer<? super V> action;
4757	>	if ((action = this.action) != null) {
4758	>	for (int i = baseIndex, f, h; batch > 0 &&
4759	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4760	>	addToPendingCount(1);
4761	>	new ForEachValueTask<K,V>
4762	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4763	>	action).fork();
4764	>	}
4765	>	for (Node<K,V> p; (p = advance()) != null;)
4766	>	action.accept(p.val);
4767	>	propagateCompletion();
4768		}
4769		}
4770	+	}
4771
4772	<	// Read the keys and values, and put the mappings in the table
4773	<	for (;;) {
4774	<	K key = (K) s.readObject();
4775	<	V value = (V) s.readObject();
4776	<	if (key == null)
4777	<	break;
4778	<	put(key, value);
4772	>	@SuppressWarnings("serial")
4773	>	static final class ForEachEntryTask<K,V>
4774	>	extends BulkTask<K,V,Void> {
4775	>	final Consumer<? super Entry<K,V>> action;
4776	>	ForEachEntryTask
4777	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4778	>	Consumer<? super Entry<K,V>> action) {
4779	>	super(p, b, i, f, t);
4780	>	this.action = action;
4781	>	}
4782	>	public final void compute() {
4783	>	final Consumer<? super Entry<K,V>> action;
4784	>	if ((action = this.action) != null) {
4785	>	for (int i = baseIndex, f, h; batch > 0 &&
4786	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4787	>	addToPendingCount(1);
4788	>	new ForEachEntryTask<K,V>
4789	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4790	>	action).fork();
4791	>	}
4792	>	for (Node<K,V> p; (p = advance()) != null; )
4793	>	action.accept(p);
4794	>	propagateCompletion();
4795	>	}
4796	>	}
4797	>	}
4798	>
4799	>	@SuppressWarnings("serial")
4800	>	static final class ForEachMappingTask<K,V>
4801	>	extends BulkTask<K,V,Void> {
4802	>	final BiConsumer<? super K, ? super V> action;
4803	>	ForEachMappingTask
4804	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4805	>	BiConsumer<? super K,? super V> action) {
4806	>	super(p, b, i, f, t);
4807	>	this.action = action;
4808	>	}
4809	>	public final void compute() {
4810	>	final BiConsumer<? super K, ? super V> action;
4811	>	if ((action = this.action) != null) {
4812	>	for (int i = baseIndex, f, h; batch > 0 &&
4813	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4814	>	addToPendingCount(1);
4815	>	new ForEachMappingTask<K,V>
4816	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4817	>	action).fork();
4818	>	}
4819	>	for (Node<K,V> p; (p = advance()) != null; )
4820	>	action.accept(p.key, p.val);
4821	>	propagateCompletion();
4822	>	}
4823	>	}
4824	>	}
4825	>
4826	>	@SuppressWarnings("serial")
4827	>	static final class ForEachTransformedKeyTask<K,V,U>
4828	>	extends BulkTask<K,V,Void> {
4829	>	final Function<? super K, ? extends U> transformer;
4830	>	final Consumer<? super U> action;
4831	>	ForEachTransformedKeyTask
4832	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4833	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4834	>	super(p, b, i, f, t);
4835	>	this.transformer = transformer; this.action = action;
4836	>	}
4837	>	public final void compute() {
4838	>	final Function<? super K, ? extends U> transformer;
4839	>	final Consumer<? super U> action;
4840	>	if ((transformer = this.transformer) != null &&
4841	>	(action = this.action) != null) {
4842	>	for (int i = baseIndex, f, h; batch > 0 &&
4843	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4844	>	addToPendingCount(1);
4845	>	new ForEachTransformedKeyTask<K,V,U>
4846	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4847	>	transformer, action).fork();
4848	>	}
4849	>	for (Node<K,V> p; (p = advance()) != null; ) {
4850	>	U u;
4851	>	if ((u = transformer.apply(p.key)) != null)
4852	>	action.accept(u);
4853	>	}
4854	>	propagateCompletion();
4855	>	}
4856	>	}
4857	>	}
4858	>
4859	>	@SuppressWarnings("serial")
4860	>	static final class ForEachTransformedValueTask<K,V,U>
4861	>	extends BulkTask<K,V,Void> {
4862	>	final Function<? super V, ? extends U> transformer;
4863	>	final Consumer<? super U> action;
4864	>	ForEachTransformedValueTask
4865	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4866	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4867	>	super(p, b, i, f, t);
4868	>	this.transformer = transformer; this.action = action;
4869	>	}
4870	>	public final void compute() {
4871	>	final Function<? super V, ? extends U> transformer;
4872	>	final Consumer<? super U> action;
4873	>	if ((transformer = this.transformer) != null &&
4874	>	(action = this.action) != null) {
4875	>	for (int i = baseIndex, f, h; batch > 0 &&
4876	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4877	>	addToPendingCount(1);
4878	>	new ForEachTransformedValueTask<K,V,U>
4879	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4880	>	transformer, action).fork();
4881	>	}
4882	>	for (Node<K,V> p; (p = advance()) != null; ) {
4883	>	U u;
4884	>	if ((u = transformer.apply(p.val)) != null)
4885	>	action.accept(u);
4886	>	}
4887	>	propagateCompletion();
4888	>	}
4889	>	}
4890	>	}
4891	>
4892	>	@SuppressWarnings("serial")
4893	>	static final class ForEachTransformedEntryTask<K,V,U>
4894	>	extends BulkTask<K,V,Void> {
4895	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4896	>	final Consumer<? super U> action;
4897	>	ForEachTransformedEntryTask
4898	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4899	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4900	>	super(p, b, i, f, t);
4901	>	this.transformer = transformer; this.action = action;
4902	>	}
4903	>	public final void compute() {
4904	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4905	>	final Consumer<? super U> action;
4906	>	if ((transformer = this.transformer) != null &&
4907	>	(action = this.action) != null) {
4908	>	for (int i = baseIndex, f, h; batch > 0 &&
4909	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4910	>	addToPendingCount(1);
4911	>	new ForEachTransformedEntryTask<K,V,U>
4912	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4913	>	transformer, action).fork();
4914	>	}
4915	>	for (Node<K,V> p; (p = advance()) != null; ) {
4916	>	U u;
4917	>	if ((u = transformer.apply(p)) != null)
4918	>	action.accept(u);
4919	>	}
4920	>	propagateCompletion();
4921	>	}
4922	>	}
4923	>	}
4924	>
4925	>	@SuppressWarnings("serial")
4926	>	static final class ForEachTransformedMappingTask<K,V,U>
4927	>	extends BulkTask<K,V,Void> {
4928	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4929	>	final Consumer<? super U> action;
4930	>	ForEachTransformedMappingTask
4931	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4932	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4933	>	Consumer<? super U> action) {
4934	>	super(p, b, i, f, t);
4935	>	this.transformer = transformer; this.action = action;
4936	>	}
4937	>	public final void compute() {
4938	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4939	>	final Consumer<? super U> action;
4940	>	if ((transformer = this.transformer) != null &&
4941	>	(action = this.action) != null) {
4942	>	for (int i = baseIndex, f, h; batch > 0 &&
4943	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4944	>	addToPendingCount(1);
4945	>	new ForEachTransformedMappingTask<K,V,U>
4946	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4947	>	transformer, action).fork();
4948	>	}
4949	>	for (Node<K,V> p; (p = advance()) != null; ) {
4950	>	U u;
4951	>	if ((u = transformer.apply(p.key, p.val)) != null)
4952	>	action.accept(u);
4953	>	}
4954	>	propagateCompletion();
4955	>	}
4956	>	}
4957	>	}
4958	>
4959	>	@SuppressWarnings("serial")
4960	>	static final class SearchKeysTask<K,V,U>
4961	>	extends BulkTask<K,V,U> {
4962	>	final Function<? super K, ? extends U> searchFunction;
4963	>	final AtomicReference<U> result;
4964	>	SearchKeysTask
4965	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4966	>	Function<? super K, ? extends U> searchFunction,
4967	>	AtomicReference<U> result) {
4968	>	super(p, b, i, f, t);
4969	>	this.searchFunction = searchFunction; this.result = result;
4970	>	}
4971	>	public final U getRawResult() { return result.get(); }
4972	>	public final void compute() {
4973	>	final Function<? super K, ? extends U> searchFunction;
4974	>	final AtomicReference<U> result;
4975	>	if ((searchFunction = this.searchFunction) != null &&
4976	>	(result = this.result) != null) {
4977	>	for (int i = baseIndex, f, h; batch > 0 &&
4978	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4979	>	if (result.get() != null)
4980	>	return;
4981	>	addToPendingCount(1);
4982	>	new SearchKeysTask<K,V,U>
4983	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4984	>	searchFunction, result).fork();
4985	>	}
4986	>	while (result.get() == null) {
4987	>	U u;
4988	>	Node<K,V> p;
4989	>	if ((p = advance()) == null) {
4990	>	propagateCompletion();
4991	>	break;
4992	>	}
4993	>	if ((u = searchFunction.apply(p.key)) != null) {
4994	>	if (result.compareAndSet(null, u))
4995	>	quietlyCompleteRoot();
4996	>	break;
4997	>	}
4998	>	}
4999	>	}
5000	>	}
5001	>	}
5002	>
5003	>	@SuppressWarnings("serial")
5004	>	static final class SearchValuesTask<K,V,U>
5005	>	extends BulkTask<K,V,U> {
5006	>	final Function<? super V, ? extends U> searchFunction;
5007	>	final AtomicReference<U> result;
5008	>	SearchValuesTask
5009	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5010	>	Function<? super V, ? extends U> searchFunction,
5011	>	AtomicReference<U> result) {
5012	>	super(p, b, i, f, t);
5013	>	this.searchFunction = searchFunction; this.result = result;
5014	>	}
5015	>	public final U getRawResult() { return result.get(); }
5016	>	public final void compute() {
5017	>	final Function<? super V, ? extends U> searchFunction;
5018	>	final AtomicReference<U> result;
5019	>	if ((searchFunction = this.searchFunction) != null &&
5020	>	(result = this.result) != null) {
5021	>	for (int i = baseIndex, f, h; batch > 0 &&
5022	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5023	>	if (result.get() != null)
5024	>	return;
5025	>	addToPendingCount(1);
5026	>	new SearchValuesTask<K,V,U>
5027	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5028	>	searchFunction, result).fork();
5029	>	}
5030	>	while (result.get() == null) {
5031	>	U u;
5032	>	Node<K,V> p;
5033	>	if ((p = advance()) == null) {
5034	>	propagateCompletion();
5035	>	break;
5036	>	}
5037	>	if ((u = searchFunction.apply(p.val)) != null) {
5038	>	if (result.compareAndSet(null, u))
5039	>	quietlyCompleteRoot();
5040	>	break;
5041	>	}
5042	>	}
5043	>	}
5044	>	}
5045	>	}
5046	>
5047	>	@SuppressWarnings("serial")
5048	>	static final class SearchEntriesTask<K,V,U>
5049	>	extends BulkTask<K,V,U> {
5050	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5051	>	final AtomicReference<U> result;
5052	>	SearchEntriesTask
5053	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5054	>	Function<Entry<K,V>, ? extends U> searchFunction,
5055	>	AtomicReference<U> result) {
5056	>	super(p, b, i, f, t);
5057	>	this.searchFunction = searchFunction; this.result = result;
5058	>	}
5059	>	public final U getRawResult() { return result.get(); }
5060	>	public final void compute() {
5061	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5062	>	final AtomicReference<U> result;
5063	>	if ((searchFunction = this.searchFunction) != null &&
5064	>	(result = this.result) != null) {
5065	>	for (int i = baseIndex, f, h; batch > 0 &&
5066	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5067	>	if (result.get() != null)
5068	>	return;
5069	>	addToPendingCount(1);
5070	>	new SearchEntriesTask<K,V,U>
5071	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5072	>	searchFunction, result).fork();
5073	>	}
5074	>	while (result.get() == null) {
5075	>	U u;
5076	>	Node<K,V> p;
5077	>	if ((p = advance()) == null) {
5078	>	propagateCompletion();
5079	>	break;
5080	>	}
5081	>	if ((u = searchFunction.apply(p)) != null) {
5082	>	if (result.compareAndSet(null, u))
5083	>	quietlyCompleteRoot();
5084	>	return;
5085	>	}
5086	>	}
5087	>	}
5088	>	}
5089	>	}
5090	>
5091	>	@SuppressWarnings("serial")
5092	>	static final class SearchMappingsTask<K,V,U>
5093	>	extends BulkTask<K,V,U> {
5094	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5095	>	final AtomicReference<U> result;
5096	>	SearchMappingsTask
5097	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5098	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5099	>	AtomicReference<U> result) {
5100	>	super(p, b, i, f, t);
5101	>	this.searchFunction = searchFunction; this.result = result;
5102	>	}
5103	>	public final U getRawResult() { return result.get(); }
5104	>	public final void compute() {
5105	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5106	>	final AtomicReference<U> result;
5107	>	if ((searchFunction = this.searchFunction) != null &&
5108	>	(result = this.result) != null) {
5109	>	for (int i = baseIndex, f, h; batch > 0 &&
5110	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5111	>	if (result.get() != null)
5112	>	return;
5113	>	addToPendingCount(1);
5114	>	new SearchMappingsTask<K,V,U>
5115	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5116	>	searchFunction, result).fork();
5117	>	}
5118	>	while (result.get() == null) {
5119	>	U u;
5120	>	Node<K,V> p;
5121	>	if ((p = advance()) == null) {
5122	>	propagateCompletion();
5123	>	break;
5124	>	}
5125	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5126	>	if (result.compareAndSet(null, u))
5127	>	quietlyCompleteRoot();
5128	>	break;
5129	>	}
5130	>	}
5131	>	}
5132	>	}
5133	>	}
5134	>
5135	>	@SuppressWarnings("serial")
5136	>	static final class ReduceKeysTask<K,V>
5137	>	extends BulkTask<K,V,K> {
5138	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5139	>	K result;
5140	>	ReduceKeysTask<K,V> rights, nextRight;
5141	>	ReduceKeysTask
5142	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5143	>	ReduceKeysTask<K,V> nextRight,
5144	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5145	>	super(p, b, i, f, t); this.nextRight = nextRight;
5146	>	this.reducer = reducer;
5147	>	}
5148	>	public final K getRawResult() { return result; }
5149	>	public final void compute() {
5150	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5151	>	if ((reducer = this.reducer) != null) {
5152	>	for (int i = baseIndex, f, h; batch > 0 &&
5153	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5154	>	addToPendingCount(1);
5155	>	(rights = new ReduceKeysTask<K,V>
5156	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5157	>	rights, reducer)).fork();
5158	>	}
5159	>	K r = null;
5160	>	for (Node<K,V> p; (p = advance()) != null; ) {
5161	>	K u = p.key;
5162	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5163	>	}
5164	>	result = r;
5165	>	CountedCompleter<?> c;
5166	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5167	>	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5168	>	t = (ReduceKeysTask<K,V>)c,
5169	>	s = t.rights;
5170	>	while (s != null) {
5171	>	K tr, sr;
5172	>	if ((sr = s.result) != null)
5173	>	t.result = (((tr = t.result) == null) ? sr :
5174	>	reducer.apply(tr, sr));
5175	>	s = t.rights = s.nextRight;
5176	>	}
5177	>	}
5178	>	}
5179	>	}
5180	>	}
5181	>
5182	>	@SuppressWarnings("serial")
5183	>	static final class ReduceValuesTask<K,V>
5184	>	extends BulkTask<K,V,V> {
5185	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5186	>	V result;
5187	>	ReduceValuesTask<K,V> rights, nextRight;
5188	>	ReduceValuesTask
5189	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5190	>	ReduceValuesTask<K,V> nextRight,
5191	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5192	>	super(p, b, i, f, t); this.nextRight = nextRight;
5193	>	this.reducer = reducer;
5194	>	}
5195	>	public final V getRawResult() { return result; }
5196	>	public final void compute() {
5197	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5198	>	if ((reducer = this.reducer) != null) {
5199	>	for (int i = baseIndex, f, h; batch > 0 &&
5200	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5201	>	addToPendingCount(1);
5202	>	(rights = new ReduceValuesTask<K,V>
5203	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5204	>	rights, reducer)).fork();
5205	>	}
5206	>	V r = null;
5207	>	for (Node<K,V> p; (p = advance()) != null; ) {
5208	>	V v = p.val;
5209	>	r = (r == null) ? v : reducer.apply(r, v);
5210	>	}
5211	>	result = r;
5212	>	CountedCompleter<?> c;
5213	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5214	>	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5215	>	t = (ReduceValuesTask<K,V>)c,
5216	>	s = t.rights;
5217	>	while (s != null) {
5218	>	V tr, sr;
5219	>	if ((sr = s.result) != null)
5220	>	t.result = (((tr = t.result) == null) ? sr :
5221	>	reducer.apply(tr, sr));
5222	>	s = t.rights = s.nextRight;
5223	>	}
5224	>	}
5225	>	}
5226	>	}
5227	>	}
5228	>
5229	>	@SuppressWarnings("serial")
5230	>	static final class ReduceEntriesTask<K,V>
5231	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5232	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5233	>	Map.Entry<K,V> result;
5234	>	ReduceEntriesTask<K,V> rights, nextRight;
5235	>	ReduceEntriesTask
5236	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5237	>	ReduceEntriesTask<K,V> nextRight,
5238	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5239	>	super(p, b, i, f, t); this.nextRight = nextRight;
5240	>	this.reducer = reducer;
5241	>	}
5242	>	public final Map.Entry<K,V> getRawResult() { return result; }
5243	>	public final void compute() {
5244	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5245	>	if ((reducer = this.reducer) != null) {
5246	>	for (int i = baseIndex, f, h; batch > 0 &&
5247	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5248	>	addToPendingCount(1);
5249	>	(rights = new ReduceEntriesTask<K,V>
5250	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5251	>	rights, reducer)).fork();
5252	>	}
5253	>	Map.Entry<K,V> r = null;
5254	>	for (Node<K,V> p; (p = advance()) != null; )
5255	>	r = (r == null) ? p : reducer.apply(r, p);
5256	>	result = r;
5257	>	CountedCompleter<?> c;
5258	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5259	>	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5260	>	t = (ReduceEntriesTask<K,V>)c,
5261	>	s = t.rights;
5262	>	while (s != null) {
5263	>	Map.Entry<K,V> tr, sr;
5264	>	if ((sr = s.result) != null)
5265	>	t.result = (((tr = t.result) == null) ? sr :
5266	>	reducer.apply(tr, sr));
5267	>	s = t.rights = s.nextRight;
5268	>	}
5269	>	}
5270	>	}
5271	>	}
5272	>	}
5273	>
5274	>	@SuppressWarnings("serial")
5275	>	static final class MapReduceKeysTask<K,V,U>
5276	>	extends BulkTask<K,V,U> {
5277	>	final Function<? super K, ? extends U> transformer;
5278	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5279	>	U result;
5280	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5281	>	MapReduceKeysTask
5282	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5283	>	MapReduceKeysTask<K,V,U> nextRight,
5284	>	Function<? super K, ? extends U> transformer,
5285	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5286	>	super(p, b, i, f, t); this.nextRight = nextRight;
5287	>	this.transformer = transformer;
5288	>	this.reducer = reducer;
5289	>	}
5290	>	public final U getRawResult() { return result; }
5291	>	public final void compute() {
5292	>	final Function<? super K, ? extends U> transformer;
5293	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5294	>	if ((transformer = this.transformer) != null &&
5295	>	(reducer = this.reducer) != null) {
5296	>	for (int i = baseIndex, f, h; batch > 0 &&
5297	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5298	>	addToPendingCount(1);
5299	>	(rights = new MapReduceKeysTask<K,V,U>
5300	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5301	>	rights, transformer, reducer)).fork();
5302	>	}
5303	>	U r = null;
5304	>	for (Node<K,V> p; (p = advance()) != null; ) {
5305	>	U u;
5306	>	if ((u = transformer.apply(p.key)) != null)
5307	>	r = (r == null) ? u : reducer.apply(r, u);
5308	>	}
5309	>	result = r;
5310	>	CountedCompleter<?> c;
5311	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5312	>	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5313	>	t = (MapReduceKeysTask<K,V,U>)c,
5314	>	s = t.rights;
5315	>	while (s != null) {
5316	>	U tr, sr;
5317	>	if ((sr = s.result) != null)
5318	>	t.result = (((tr = t.result) == null) ? sr :
5319	>	reducer.apply(tr, sr));
5320	>	s = t.rights = s.nextRight;
5321	>	}
5322	>	}
5323	>	}
5324	>	}
5325	>	}
5326	>
5327	>	@SuppressWarnings("serial")
5328	>	static final class MapReduceValuesTask<K,V,U>
5329	>	extends BulkTask<K,V,U> {
5330	>	final Function<? super V, ? extends U> transformer;
5331	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5332	>	U result;
5333	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5334	>	MapReduceValuesTask
5335	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5336	>	MapReduceValuesTask<K,V,U> nextRight,
5337	>	Function<? super V, ? extends U> transformer,
5338	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5339	>	super(p, b, i, f, t); this.nextRight = nextRight;
5340	>	this.transformer = transformer;
5341	>	this.reducer = reducer;
5342	>	}
5343	>	public final U getRawResult() { return result; }
5344	>	public final void compute() {
5345	>	final Function<? super V, ? extends U> transformer;
5346	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5347	>	if ((transformer = this.transformer) != null &&
5348	>	(reducer = this.reducer) != null) {
5349	>	for (int i = baseIndex, f, h; batch > 0 &&
5350	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5351	>	addToPendingCount(1);
5352	>	(rights = new MapReduceValuesTask<K,V,U>
5353	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5354	>	rights, transformer, reducer)).fork();
5355	>	}
5356	>	U r = null;
5357	>	for (Node<K,V> p; (p = advance()) != null; ) {
5358	>	U u;
5359	>	if ((u = transformer.apply(p.val)) != null)
5360	>	r = (r == null) ? u : reducer.apply(r, u);
5361	>	}
5362	>	result = r;
5363	>	CountedCompleter<?> c;
5364	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5365	>	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5366	>	t = (MapReduceValuesTask<K,V,U>)c,
5367	>	s = t.rights;
5368	>	while (s != null) {
5369	>	U tr, sr;
5370	>	if ((sr = s.result) != null)
5371	>	t.result = (((tr = t.result) == null) ? sr :
5372	>	reducer.apply(tr, sr));
5373	>	s = t.rights = s.nextRight;
5374	>	}
5375	>	}
5376	>	}
5377	>	}
5378	>	}
5379	>
5380	>	@SuppressWarnings("serial")
5381	>	static final class MapReduceEntriesTask<K,V,U>
5382	>	extends BulkTask<K,V,U> {
5383	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5384	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5385	>	U result;
5386	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5387	>	MapReduceEntriesTask
5388	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5389	>	MapReduceEntriesTask<K,V,U> nextRight,
5390	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5391	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5392	>	super(p, b, i, f, t); this.nextRight = nextRight;
5393	>	this.transformer = transformer;
5394	>	this.reducer = reducer;
5395	>	}
5396	>	public final U getRawResult() { return result; }
5397	>	public final void compute() {
5398	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5399	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5400	>	if ((transformer = this.transformer) != null &&
5401	>	(reducer = this.reducer) != null) {
5402	>	for (int i = baseIndex, f, h; batch > 0 &&
5403	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5404	>	addToPendingCount(1);
5405	>	(rights = new MapReduceEntriesTask<K,V,U>
5406	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5407	>	rights, transformer, reducer)).fork();
5408	>	}
5409	>	U r = null;
5410	>	for (Node<K,V> p; (p = advance()) != null; ) {
5411	>	U u;
5412	>	if ((u = transformer.apply(p)) != null)
5413	>	r = (r == null) ? u : reducer.apply(r, u);
5414	>	}
5415	>	result = r;
5416	>	CountedCompleter<?> c;
5417	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5418	>	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5419	>	t = (MapReduceEntriesTask<K,V,U>)c,
5420	>	s = t.rights;
5421	>	while (s != null) {
5422	>	U tr, sr;
5423	>	if ((sr = s.result) != null)
5424	>	t.result = (((tr = t.result) == null) ? sr :
5425	>	reducer.apply(tr, sr));
5426	>	s = t.rights = s.nextRight;
5427	>	}
5428	>	}
5429	>	}
5430	>	}
5431	>	}
5432	>
5433	>	@SuppressWarnings("serial")
5434	>	static final class MapReduceMappingsTask<K,V,U>
5435	>	extends BulkTask<K,V,U> {
5436	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5437	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5438	>	U result;
5439	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5440	>	MapReduceMappingsTask
5441	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5442	>	MapReduceMappingsTask<K,V,U> nextRight,
5443	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5444	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5445	>	super(p, b, i, f, t); this.nextRight = nextRight;
5446	>	this.transformer = transformer;
5447	>	this.reducer = reducer;
5448	>	}
5449	>	public final U getRawResult() { return result; }
5450	>	public final void compute() {
5451	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5452	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5453	>	if ((transformer = this.transformer) != null &&
5454	>	(reducer = this.reducer) != null) {
5455	>	for (int i = baseIndex, f, h; batch > 0 &&
5456	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5457	>	addToPendingCount(1);
5458	>	(rights = new MapReduceMappingsTask<K,V,U>
5459	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5460	>	rights, transformer, reducer)).fork();
5461	>	}
5462	>	U r = null;
5463	>	for (Node<K,V> p; (p = advance()) != null; ) {
5464	>	U u;
5465	>	if ((u = transformer.apply(p.key, p.val)) != null)
5466	>	r = (r == null) ? u : reducer.apply(r, u);
5467	>	}
5468	>	result = r;
5469	>	CountedCompleter<?> c;
5470	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5471	>	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5472	>	t = (MapReduceMappingsTask<K,V,U>)c,
5473	>	s = t.rights;
5474	>	while (s != null) {
5475	>	U tr, sr;
5476	>	if ((sr = s.result) != null)
5477	>	t.result = (((tr = t.result) == null) ? sr :
5478	>	reducer.apply(tr, sr));
5479	>	s = t.rights = s.nextRight;
5480	>	}
5481	>	}
5482	>	}
5483	>	}
5484	>	}
5485	>
5486	>	@SuppressWarnings("serial")
5487	>	static final class MapReduceKeysToDoubleTask<K,V>
5488	>	extends BulkTask<K,V,Double> {
5489	>	final ToDoubleFunction<? super K> transformer;
5490	>	final DoubleBinaryOperator reducer;
5491	>	final double basis;
5492	>	double result;
5493	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5494	>	MapReduceKeysToDoubleTask
5495	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5496	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5497	>	ToDoubleFunction<? super K> transformer,
5498	>	double basis,
5499	>	DoubleBinaryOperator reducer) {
5500	>	super(p, b, i, f, t); this.nextRight = nextRight;
5501	>	this.transformer = transformer;
5502	>	this.basis = basis; this.reducer = reducer;
5503	>	}
5504	>	public final Double getRawResult() { return result; }
5505	>	public final void compute() {
5506	>	final ToDoubleFunction<? super K> transformer;
5507	>	final DoubleBinaryOperator reducer;
5508	>	if ((transformer = this.transformer) != null &&
5509	>	(reducer = this.reducer) != null) {
5510	>	double r = this.basis;
5511	>	for (int i = baseIndex, f, h; batch > 0 &&
5512	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5513	>	addToPendingCount(1);
5514	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5515	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5516	>	rights, transformer, r, reducer)).fork();
5517	>	}
5518	>	for (Node<K,V> p; (p = advance()) != null; )
5519	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5520	>	result = r;
5521	>	CountedCompleter<?> c;
5522	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5523	>	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5524	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5525	>	s = t.rights;
5526	>	while (s != null) {
5527	>	t.result = reducer.applyAsDouble(t.result, s.result);
5528	>	s = t.rights = s.nextRight;
5529	>	}
5530	>	}
5531	>	}
5532	>	}
5533	>	}
5534	>
5535	>	@SuppressWarnings("serial")
5536	>	static final class MapReduceValuesToDoubleTask<K,V>
5537	>	extends BulkTask<K,V,Double> {
5538	>	final ToDoubleFunction<? super V> transformer;
5539	>	final DoubleBinaryOperator reducer;
5540	>	final double basis;
5541	>	double result;
5542	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5543	>	MapReduceValuesToDoubleTask
5544	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5545	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5546	>	ToDoubleFunction<? super V> transformer,
5547	>	double basis,
5548	>	DoubleBinaryOperator reducer) {
5549	>	super(p, b, i, f, t); this.nextRight = nextRight;
5550	>	this.transformer = transformer;
5551	>	this.basis = basis; this.reducer = reducer;
5552	>	}
5553	>	public final Double getRawResult() { return result; }
5554	>	public final void compute() {
5555	>	final ToDoubleFunction<? super V> transformer;
5556	>	final DoubleBinaryOperator reducer;
5557	>	if ((transformer = this.transformer) != null &&
5558	>	(reducer = this.reducer) != null) {
5559	>	double r = this.basis;
5560	>	for (int i = baseIndex, f, h; batch > 0 &&
5561	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5562	>	addToPendingCount(1);
5563	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5564	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5565	>	rights, transformer, r, reducer)).fork();
5566	>	}
5567	>	for (Node<K,V> p; (p = advance()) != null; )
5568	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5569	>	result = r;
5570	>	CountedCompleter<?> c;
5571	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5572	>	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5573	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5574	>	s = t.rights;
5575	>	while (s != null) {
5576	>	t.result = reducer.applyAsDouble(t.result, s.result);
5577	>	s = t.rights = s.nextRight;
5578	>	}
5579	>	}
5580	>	}
5581	>	}
5582	>	}
5583	>
5584	>	@SuppressWarnings("serial")
5585	>	static final class MapReduceEntriesToDoubleTask<K,V>
5586	>	extends BulkTask<K,V,Double> {
5587	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5588	>	final DoubleBinaryOperator reducer;
5589	>	final double basis;
5590	>	double result;
5591	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5592	>	MapReduceEntriesToDoubleTask
5593	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5594	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5595	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5596	>	double basis,
5597	>	DoubleBinaryOperator reducer) {
5598	>	super(p, b, i, f, t); this.nextRight = nextRight;
5599	>	this.transformer = transformer;
5600	>	this.basis = basis; this.reducer = reducer;
5601	>	}
5602	>	public final Double getRawResult() { return result; }
5603	>	public final void compute() {
5604	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5605	>	final DoubleBinaryOperator reducer;
5606	>	if ((transformer = this.transformer) != null &&
5607	>	(reducer = this.reducer) != null) {
5608	>	double r = this.basis;
5609	>	for (int i = baseIndex, f, h; batch > 0 &&
5610	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5611	>	addToPendingCount(1);
5612	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5613	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5614	>	rights, transformer, r, reducer)).fork();
5615	>	}
5616	>	for (Node<K,V> p; (p = advance()) != null; )
5617	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5618	>	result = r;
5619	>	CountedCompleter<?> c;
5620	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5621	>	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5622	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5623	>	s = t.rights;
5624	>	while (s != null) {
5625	>	t.result = reducer.applyAsDouble(t.result, s.result);
5626	>	s = t.rights = s.nextRight;
5627	>	}
5628	>	}
5629	>	}
5630	>	}
5631	>	}
5632	>
5633	>	@SuppressWarnings("serial")
5634	>	static final class MapReduceMappingsToDoubleTask<K,V>
5635	>	extends BulkTask<K,V,Double> {
5636	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5637	>	final DoubleBinaryOperator reducer;
5638	>	final double basis;
5639	>	double result;
5640	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5641	>	MapReduceMappingsToDoubleTask
5642	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5643	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5644	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5645	>	double basis,
5646	>	DoubleBinaryOperator reducer) {
5647	>	super(p, b, i, f, t); this.nextRight = nextRight;
5648	>	this.transformer = transformer;
5649	>	this.basis = basis; this.reducer = reducer;
5650	>	}
5651	>	public final Double getRawResult() { return result; }
5652	>	public final void compute() {
5653	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5654	>	final DoubleBinaryOperator reducer;
5655	>	if ((transformer = this.transformer) != null &&
5656	>	(reducer = this.reducer) != null) {
5657	>	double r = this.basis;
5658	>	for (int i = baseIndex, f, h; batch > 0 &&
5659	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5660	>	addToPendingCount(1);
5661	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5662	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5663	>	rights, transformer, r, reducer)).fork();
5664	>	}
5665	>	for (Node<K,V> p; (p = advance()) != null; )
5666	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5667	>	result = r;
5668	>	CountedCompleter<?> c;
5669	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5670	>	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5671	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5672	>	s = t.rights;
5673	>	while (s != null) {
5674	>	t.result = reducer.applyAsDouble(t.result, s.result);
5675	>	s = t.rights = s.nextRight;
5676	>	}
5677	>	}
5678	>	}
5679	>	}
5680	>	}
5681	>
5682	>	@SuppressWarnings("serial")
5683	>	static final class MapReduceKeysToLongTask<K,V>
5684	>	extends BulkTask<K,V,Long> {
5685	>	final ToLongFunction<? super K> transformer;
5686	>	final LongBinaryOperator reducer;
5687	>	final long basis;
5688	>	long result;
5689	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5690	>	MapReduceKeysToLongTask
5691	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5692	>	MapReduceKeysToLongTask<K,V> nextRight,
5693	>	ToLongFunction<? super K> transformer,
5694	>	long basis,
5695	>	LongBinaryOperator 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 Long getRawResult() { return result; }
5701	>	public final void compute() {
5702	>	final ToLongFunction<? super K> transformer;
5703	>	final LongBinaryOperator reducer;
5704	>	if ((transformer = this.transformer) != null &&
5705	>	(reducer = this.reducer) != null) {
5706	>	long 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 MapReduceKeysToLongTask<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.applyAsLong(r, transformer.applyAsLong(p.key));
5716	>	result = r;
5717	>	CountedCompleter<?> c;
5718	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5719	>	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5720	>	t = (MapReduceKeysToLongTask<K,V>)c,
5721	>	s = t.rights;
5722	>	while (s != null) {
5723	>	t.result = reducer.applyAsLong(t.result, s.result);
5724	>	s = t.rights = s.nextRight;
5725	>	}
5726	>	}
5727	>	}
5728	>	}
5729	>	}
5730	>
5731	>	@SuppressWarnings("serial")
5732	>	static final class MapReduceValuesToLongTask<K,V>
5733	>	extends BulkTask<K,V,Long> {
5734	>	final ToLongFunction<? super V> transformer;
5735	>	final LongBinaryOperator reducer;
5736	>	final long basis;
5737	>	long result;
5738	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5739	>	MapReduceValuesToLongTask
5740	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5741	>	MapReduceValuesToLongTask<K,V> nextRight,
5742	>	ToLongFunction<? super V> transformer,
5743	>	long basis,
5744	>	LongBinaryOperator reducer) {
5745	>	super(p, b, i, f, t); this.nextRight = nextRight;
5746	>	this.transformer = transformer;
5747	>	this.basis = basis; this.reducer = reducer;
5748	>	}
5749	>	public final Long getRawResult() { return result; }
5750	>	public final void compute() {
5751	>	final ToLongFunction<? super V> transformer;
5752	>	final LongBinaryOperator reducer;
5753	>	if ((transformer = this.transformer) != null &&
5754	>	(reducer = this.reducer) != null) {
5755	>	long r = this.basis;
5756	>	for (int i = baseIndex, f, h; batch > 0 &&
5757	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5758	>	addToPendingCount(1);
5759	>	(rights = new MapReduceValuesToLongTask<K,V>
5760	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5761	>	rights, transformer, r, reducer)).fork();
5762	>	}
5763	>	for (Node<K,V> p; (p = advance()) != null; )
5764	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5765	>	result = r;
5766	>	CountedCompleter<?> c;
5767	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5768	>	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5769	>	t = (MapReduceValuesToLongTask<K,V>)c,
5770	>	s = t.rights;
5771	>	while (s != null) {
5772	>	t.result = reducer.applyAsLong(t.result, s.result);
5773	>	s = t.rights = s.nextRight;
5774	>	}
5775	>	}
5776	>	}
5777	>	}
5778	>	}
5779	>
5780	>	@SuppressWarnings("serial")
5781	>	static final class MapReduceEntriesToLongTask<K,V>
5782	>	extends BulkTask<K,V,Long> {
5783	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5784	>	final LongBinaryOperator reducer;
5785	>	final long basis;
5786	>	long result;
5787	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5788	>	MapReduceEntriesToLongTask
5789	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5790	>	MapReduceEntriesToLongTask<K,V> nextRight,
5791	>	ToLongFunction<Map.Entry<K,V>> transformer,
5792	>	long basis,
5793	>	LongBinaryOperator reducer) {
5794	>	super(p, b, i, f, t); this.nextRight = nextRight;
5795	>	this.transformer = transformer;
5796	>	this.basis = basis; this.reducer = reducer;
5797	>	}
5798	>	public final Long getRawResult() { return result; }
5799	>	public final void compute() {
5800	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5801	>	final LongBinaryOperator reducer;
5802	>	if ((transformer = this.transformer) != null &&
5803	>	(reducer = this.reducer) != null) {
5804	>	long r = this.basis;
5805	>	for (int i = baseIndex, f, h; batch > 0 &&
5806	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5807	>	addToPendingCount(1);
5808	>	(rights = new MapReduceEntriesToLongTask<K,V>
5809	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5810	>	rights, transformer, r, reducer)).fork();
5811	>	}
5812	>	for (Node<K,V> p; (p = advance()) != null; )
5813	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5814	>	result = r;
5815	>	CountedCompleter<?> c;
5816	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5817	>	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5818	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5819	>	s = t.rights;
5820	>	while (s != null) {
5821	>	t.result = reducer.applyAsLong(t.result, s.result);
5822	>	s = t.rights = s.nextRight;
5823	>	}
5824	>	}
5825	>	}
5826	>	}
5827	>	}
5828	>
5829	>	@SuppressWarnings("serial")
5830	>	static final class MapReduceMappingsToLongTask<K,V>
5831	>	extends BulkTask<K,V,Long> {
5832	>	final ToLongBiFunction<? super K, ? super V> transformer;
5833	>	final LongBinaryOperator reducer;
5834	>	final long basis;
5835	>	long result;
5836	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5837	>	MapReduceMappingsToLongTask
5838	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5839	>	MapReduceMappingsToLongTask<K,V> nextRight,
5840	>	ToLongBiFunction<? super K, ? super V> transformer,
5841	>	long basis,
5842	>	LongBinaryOperator reducer) {
5843	>	super(p, b, i, f, t); this.nextRight = nextRight;
5844	>	this.transformer = transformer;
5845	>	this.basis = basis; this.reducer = reducer;
5846	>	}
5847	>	public final Long getRawResult() { return result; }
5848	>	public final void compute() {
5849	>	final ToLongBiFunction<? super K, ? super V> transformer;
5850	>	final LongBinaryOperator reducer;
5851	>	if ((transformer = this.transformer) != null &&
5852	>	(reducer = this.reducer) != null) {
5853	>	long r = this.basis;
5854	>	for (int i = baseIndex, f, h; batch > 0 &&
5855	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5856	>	addToPendingCount(1);
5857	>	(rights = new MapReduceMappingsToLongTask<K,V>
5858	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5859	>	rights, transformer, r, reducer)).fork();
5860	>	}
5861	>	for (Node<K,V> p; (p = advance()) != null; )
5862	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
5863	>	result = r;
5864	>	CountedCompleter<?> c;
5865	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5866	>	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5867	>	t = (MapReduceMappingsToLongTask<K,V>)c,
5868	>	s = t.rights;
5869	>	while (s != null) {
5870	>	t.result = reducer.applyAsLong(t.result, s.result);
5871	>	s = t.rights = s.nextRight;
5872	>	}
5873	>	}
5874	>	}
5875	>	}
5876	>	}
5877	>
5878	>	@SuppressWarnings("serial")
5879	>	static final class MapReduceKeysToIntTask<K,V>
5880	>	extends BulkTask<K,V,Integer> {
5881	>	final ToIntFunction<? super K> transformer;
5882	>	final IntBinaryOperator reducer;
5883	>	final int basis;
5884	>	int result;
5885	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
5886	>	MapReduceKeysToIntTask
5887	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5888	>	MapReduceKeysToIntTask<K,V> nextRight,
5889	>	ToIntFunction<? super K> transformer,
5890	>	int basis,
5891	>	IntBinaryOperator reducer) {
5892	>	super(p, b, i, f, t); this.nextRight = nextRight;
5893	>	this.transformer = transformer;
5894	>	this.basis = basis; this.reducer = reducer;
5895	>	}
5896	>	public final Integer getRawResult() { return result; }
5897	>	public final void compute() {
5898	>	final ToIntFunction<? super K> transformer;
5899	>	final IntBinaryOperator reducer;
5900	>	if ((transformer = this.transformer) != null &&
5901	>	(reducer = this.reducer) != null) {
5902	>	int r = this.basis;
5903	>	for (int i = baseIndex, f, h; batch > 0 &&
5904	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5905	>	addToPendingCount(1);
5906	>	(rights = new MapReduceKeysToIntTask<K,V>
5907	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5908	>	rights, transformer, r, reducer)).fork();
5909	>	}
5910	>	for (Node<K,V> p; (p = advance()) != null; )
5911	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
5912	>	result = r;
5913	>	CountedCompleter<?> c;
5914	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5915	>	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5916	>	t = (MapReduceKeysToIntTask<K,V>)c,
5917	>	s = t.rights;
5918	>	while (s != null) {
5919	>	t.result = reducer.applyAsInt(t.result, s.result);
5920	>	s = t.rights = s.nextRight;
5921	>	}
5922	>	}
5923	>	}
5924	>	}
5925	>	}
5926	>
5927	>	@SuppressWarnings("serial")
5928	>	static final class MapReduceValuesToIntTask<K,V>
5929	>	extends BulkTask<K,V,Integer> {
5930	>	final ToIntFunction<? super V> transformer;
5931	>	final IntBinaryOperator reducer;
5932	>	final int basis;
5933	>	int result;
5934	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
5935	>	MapReduceValuesToIntTask
5936	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5937	>	MapReduceValuesToIntTask<K,V> nextRight,
5938	>	ToIntFunction<? super V> transformer,
5939	>	int basis,
5940	>	IntBinaryOperator reducer) {
5941	>	super(p, b, i, f, t); this.nextRight = nextRight;
5942	>	this.transformer = transformer;
5943	>	this.basis = basis; this.reducer = reducer;
5944	>	}
5945	>	public final Integer getRawResult() { return result; }
5946	>	public final void compute() {
5947	>	final ToIntFunction<? super V> transformer;
5948	>	final IntBinaryOperator reducer;
5949	>	if ((transformer = this.transformer) != null &&
5950	>	(reducer = this.reducer) != null) {
5951	>	int r = this.basis;
5952	>	for (int i = baseIndex, f, h; batch > 0 &&
5953	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5954	>	addToPendingCount(1);
5955	>	(rights = new MapReduceValuesToIntTask<K,V>
5956	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5957	>	rights, transformer, r, reducer)).fork();
5958	>	}
5959	>	for (Node<K,V> p; (p = advance()) != null; )
5960	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5961	>	result = r;
5962	>	CountedCompleter<?> c;
5963	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5964	>	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5965	>	t = (MapReduceValuesToIntTask<K,V>)c,
5966	>	s = t.rights;
5967	>	while (s != null) {
5968	>	t.result = reducer.applyAsInt(t.result, s.result);
5969	>	s = t.rights = s.nextRight;
5970	>	}
5971	>	}
5972	>	}
5973	>	}
5974	>	}
5975	>
5976	>	@SuppressWarnings("serial")
5977	>	static final class MapReduceEntriesToIntTask<K,V>
5978	>	extends BulkTask<K,V,Integer> {
5979	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5980	>	final IntBinaryOperator reducer;
5981	>	final int basis;
5982	>	int result;
5983	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5984	>	MapReduceEntriesToIntTask
5985	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5986	>	MapReduceEntriesToIntTask<K,V> nextRight,
5987	>	ToIntFunction<Map.Entry<K,V>> transformer,
5988	>	int basis,
5989	>	IntBinaryOperator reducer) {
5990	>	super(p, b, i, f, t); this.nextRight = nextRight;
5991	>	this.transformer = transformer;
5992	>	this.basis = basis; this.reducer = reducer;
5993	>	}
5994	>	public final Integer getRawResult() { return result; }
5995	>	public final void compute() {
5996	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5997	>	final IntBinaryOperator reducer;
5998	>	if ((transformer = this.transformer) != null &&
5999	>	(reducer = this.reducer) != null) {
6000	>	int r = this.basis;
6001	>	for (int i = baseIndex, f, h; batch > 0 &&
6002	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6003	>	addToPendingCount(1);
6004	>	(rights = new MapReduceEntriesToIntTask<K,V>
6005	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6006	>	rights, transformer, r, reducer)).fork();
6007	>	}
6008	>	for (Node<K,V> p; (p = advance()) != null; )
6009	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6010	>	result = r;
6011	>	CountedCompleter<?> c;
6012	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6013	>	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
6014	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6015	>	s = t.rights;
6016	>	while (s != null) {
6017	>	t.result = reducer.applyAsInt(t.result, s.result);
6018	>	s = t.rights = s.nextRight;
6019	>	}
6020	>	}
6021	>	}
6022	>	}
6023	>	}
6024	>
6025	>	@SuppressWarnings("serial")
6026	>	static final class MapReduceMappingsToIntTask<K,V>
6027	>	extends BulkTask<K,V,Integer> {
6028	>	final ToIntBiFunction<? super K, ? super V> transformer;
6029	>	final IntBinaryOperator reducer;
6030	>	final int basis;
6031	>	int result;
6032	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6033	>	MapReduceMappingsToIntTask
6034	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6035	>	MapReduceMappingsToIntTask<K,V> nextRight,
6036	>	ToIntBiFunction<? super K, ? super V> transformer,
6037	>	int basis,
6038	>	IntBinaryOperator reducer) {
6039	>	super(p, b, i, f, t); this.nextRight = nextRight;
6040	>	this.transformer = transformer;
6041	>	this.basis = basis; this.reducer = reducer;
6042	>	}
6043	>	public final Integer getRawResult() { return result; }
6044	>	public final void compute() {
6045	>	final ToIntBiFunction<? super K, ? super V> transformer;
6046	>	final IntBinaryOperator reducer;
6047	>	if ((transformer = this.transformer) != null &&
6048	>	(reducer = this.reducer) != null) {
6049	>	int r = this.basis;
6050	>	for (int i = baseIndex, f, h; batch > 0 &&
6051	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6052	>	addToPendingCount(1);
6053	>	(rights = new MapReduceMappingsToIntTask<K,V>
6054	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6055	>	rights, transformer, r, reducer)).fork();
6056	>	}
6057	>	for (Node<K,V> p; (p = advance()) != null; )
6058	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6059	>	result = r;
6060	>	CountedCompleter<?> c;
6061	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6062	>	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6063	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6064	>	s = t.rights;
6065	>	while (s != null) {
6066	>	t.result = reducer.applyAsInt(t.result, s.result);
6067	>	s = t.rights = s.nextRight;
6068	>	}
6069	>	}
6070	>	}
6071		}
6072		}
6073
6074		// Unsafe mechanics
6075	<	private static final sun.misc.Unsafe UNSAFE;
6076	<	private static final long SBASE;
6077	<	private static final int SSHIFT;
6078	<	private static final long TBASE;
6079	<	private static final int TSHIFT;
6075	>	private static final sun.misc.Unsafe U;
6076	>	private static final long SIZECTL;
6077	>	private static final long TRANSFERINDEX;
6078	>	private static final long TRANSFERORIGIN;
6079	>	private static final long BASECOUNT;
6080	>	private static final long CELLSBUSY;
6081	>	private static final long CELLVALUE;
6082	>	private static final long ABASE;
6083	>	private static final int ASHIFT;
6084
6085		static {
1466	–	int ss, ts;
6086		try {
6087	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6088	<	Class<?> tc = HashEntry[].class;
6089	<	Class<?> sc = Segment[].class;
6090	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6091	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6092	<	ts = UNSAFE.arrayIndexScale(tc);
6093	<	ss = UNSAFE.arrayIndexScale(sc);
6087	>	U = sun.misc.Unsafe.getUnsafe();
6088	>	Class<?> k = ConcurrentHashMap.class;
6089	>	SIZECTL = U.objectFieldOffset
6090	>	(k.getDeclaredField("sizeCtl"));
6091	>	TRANSFERINDEX = U.objectFieldOffset
6092	>	(k.getDeclaredField("transferIndex"));
6093	>	TRANSFERORIGIN = U.objectFieldOffset
6094	>	(k.getDeclaredField("transferOrigin"));
6095	>	BASECOUNT = U.objectFieldOffset
6096	>	(k.getDeclaredField("baseCount"));
6097	>	CELLSBUSY = U.objectFieldOffset
6098	>	(k.getDeclaredField("cellsBusy"));
6099	>	Class<?> ck = CounterCell.class;
6100	>	CELLVALUE = U.objectFieldOffset
6101	>	(ck.getDeclaredField("value"));
6102	>	Class<?> ak = Node[].class;
6103	>	ABASE = U.arrayBaseOffset(ak);
6104	>	int scale = U.arrayIndexScale(ak);
6105	>	if ((scale & (scale - 1)) != 0)
6106	>	throw new Error("data type scale not a power of two");
6107	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6108		} catch (Exception e) {
6109		throw new Error(e);
6110		}
1478	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1479	–	throw new Error("data type scale not a power of two");
1480	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1481	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6111		}
1483	–
6112		}

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