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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.110 by jsr166, Wed Apr 27 14:06:30 2011 UTC vs.
Revision 1.235 by dl, Fri Jul 5 10:40:16 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.Arrays;
14	>	import java.util.Collection;
15	>	import java.util.Comparator;
16	>	import java.util.ConcurrentModificationException;
17	>	import java.util.Enumeration;
18	>	import java.util.HashMap;
19	>	import java.util.Hashtable;
20	>	import java.util.Iterator;
21	>	import java.util.Map;
22	>	import java.util.NoSuchElementException;
23	>	import java.util.Set;
24	>	import java.util.Spliterator;
25	>	import java.util.concurrent.ConcurrentMap;
26	>	import java.util.concurrent.ForkJoinPool;
27	>	import java.util.concurrent.atomic.AtomicReference;
28	>	import java.util.concurrent.locks.LockSupport;
29	>	import java.util.concurrent.locks.ReentrantLock;
30	>	import java.util.function.BiConsumer;
31	>	import java.util.function.BiFunction;
32	>	import java.util.function.BinaryOperator;
33	>	import java.util.function.Consumer;
34	>	import java.util.function.DoubleBinaryOperator;
35	>	import java.util.function.Function;
36	>	import java.util.function.IntBinaryOperator;
37	>	import java.util.function.LongBinaryOperator;
38	>	import java.util.function.ToDoubleBiFunction;
39	>	import java.util.function.ToDoubleFunction;
40	>	import java.util.function.ToIntBiFunction;
41	>	import java.util.function.ToIntFunction;
42	>	import java.util.function.ToLongBiFunction;
43	>	import java.util.function.ToLongFunction;
44	>	import java.util.stream.Stream;
45
46		/**
47		* A hash table supporting full concurrency of retrievals and
48	<	* adjustable expected concurrency for updates. This class obeys the
48	>	* high expected concurrency for updates. This class obeys the
49		* same functional specification as {@link java.util.Hashtable}, and
50		* includes versions of methods corresponding to each method of
51	<	* <tt>Hashtable</tt>. However, even though all operations are
51	>	* {@code Hashtable}. However, even though all operations are
52		* thread-safe, retrieval operations do <em>not</em> entail locking,
53		* and there is <em>not</em> any support for locking the entire table
54		* in a way that prevents all access.  This class is fully
55	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
55	>	* interoperable with {@code Hashtable} in programs that rely on its
56		* thread safety but not on its synchronization details.
57		*
58	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
59	<	* block, so may overlap with update operations (including
60	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
61	<	* of the most recently <em>completed</em> update operations holding
62	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
63	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
64	<	* removal of only some entries.  Similarly, Iterators and
65	<	* Enumerations return elements reflecting the state of the hash table
66	<	* at some point at or since the creation of the iterator/enumeration.
67	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
68	<	* However, iterators are designed to be used by only one thread at a time.
69	<	*
70	<	* <p> The allowed concurrency among update operations is guided by
71	<	* the optional <tt>concurrencyLevel</tt> constructor argument
72	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
73	<	* table is internally partitioned to try to permit the indicated
74	<	* number of concurrent updates without contention. Because placement
75	<	* in hash tables is essentially random, the actual concurrency will
76	<	* vary.  Ideally, you should choose a value to accommodate as many
77	<	* threads as will ever concurrently modify the table. Using a
78	<	* significantly higher value than you need can waste space and time,
79	<	* and a significantly lower value can lead to thread contention. But
80	<	* overestimates and underestimates within an order of magnitude do
81	<	* not usually have much noticeable impact. A value of one is
82	<	* appropriate when it is known that only one thread will modify and
83	<	* all others will only read. Also, resizing this or any other kind of
84	<	* hash table is a relatively slow operation, so, when possible, it is
85	<	* a good idea to provide estimates of expected table sizes in
86	<	* constructors.
58	>	* <p>Retrieval operations (including {@code get}) generally do not
59	>	* block, so may overlap with update operations (including {@code put}
60	>	* and {@code remove}). Retrievals reflect the results of the most
61	>	* recently <em>completed</em> update operations holding upon their
62	>	* onset. (More formally, an update operation for a given key bears a
63	>	* <em>happens-before</em> relation with any (non-null) retrieval for
64	>	* that key reporting the updated value.)  For aggregate operations
65	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
66	>	* reflect insertion or removal of only some entries.  Similarly,
67	>	* Iterators and Enumerations return elements reflecting the state of
68	>	* the hash table at some point at or since the creation of the
69	>	* iterator/enumeration.  They do <em>not</em> throw {@link
70	>	* ConcurrentModificationException}.  However, iterators are designed
71	>	* to be used by only one thread at a time.  Bear in mind that the
72	>	* results of aggregate status methods including {@code size}, {@code
73	>	* isEmpty}, and {@code containsValue} are typically useful only when
74	>	* a map is not undergoing concurrent updates in other threads.
75	>	* Otherwise the results of these methods reflect transient states
76	>	* that may be adequate for monitoring or estimation purposes, but not
77	>	* for program control.
78	>	*
79	>	* <p>The table is dynamically expanded when there are too many
80	>	* collisions (i.e., keys that have distinct hash codes but fall into
81	>	* the same slot modulo the table size), with the expected average
82	>	* effect of maintaining roughly two bins per mapping (corresponding
83	>	* to a 0.75 load factor threshold for resizing). There may be much
84	>	* variance around this average as mappings are added and removed, but
85	>	* overall, this maintains a commonly accepted time/space tradeoff for
86	>	* hash tables.  However, resizing this or any other kind of hash
87	>	* table may be a relatively slow operation. When possible, it is a
88	>	* good idea to provide a size estimate as an optional {@code
89	>	* initialCapacity} constructor argument. An additional optional
90	>	* {@code loadFactor} constructor argument provides a further means of
91	>	* customizing initial table capacity by specifying the table density
92	>	* to be used in calculating the amount of space to allocate for the
93	>	* given number of elements.  Also, for compatibility with previous
94	>	* versions of this class, constructors may optionally specify an
95	>	* expected {@code concurrencyLevel} as an additional hint for
96	>	* internal sizing.  Note that using many keys with exactly the same
97	>	* {@code hashCode()} is a sure way to slow down performance of any
98	>	* hash table. To ameliorate impact, when keys are {@link Comparable},
99	>	* this class may use comparison order among keys to help break ties.
100	>	*
101	>	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
102	>	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
103	>	* (using {@link #keySet(Object)} when only keys are of interest, and the
104	>	* mapped values are (perhaps transiently) not used or all take the
105	>	* same mapping value.
106	>	*
107	>	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
108	>	* form of histogram or multiset) by using {@link
109	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
110	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
111	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
112	>	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
113		*
114		* <p>This class and its views and iterators implement all of the
115		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
116		* interfaces.
117		*
118	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
119	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
118	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
119	>	* does <em>not</em> allow {@code null} to be used as a key or value.
120	>	*
121	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
122	>	* operations that, unlike most {@link Stream} methods, are designed
123	>	* to be safely, and often sensibly, applied even with maps that are
124	>	* being concurrently updated by other threads; for example, when
125	>	* computing a snapshot summary of the values in a shared registry.
126	>	* There are three kinds of operation, each with four forms, accepting
127	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
128	>	* and/or return values. Because the elements of a ConcurrentHashMap
129	>	* are not ordered in any particular way, and may be processed in
130	>	* different orders in different parallel executions, the correctness
131	>	* of supplied functions should not depend on any ordering, or on any
132	>	* other objects or values that may transiently change while
133	>	* computation is in progress; and except for forEach actions, should
134	>	* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
135	>	* objects do not support method {@code setValue}.
136	>	*
137	>	* <ul>
138	>	* <li> forEach: Perform a given action on each element.
139	>	* A variant form applies a given transformation on each element
140	>	* before performing the action.</li>
141	>	*
142	>	* <li> search: Return the first available non-null result of
143	>	* applying a given function on each element; skipping further
144	>	* search when a result is found.</li>
145	>	*
146	>	* <li> reduce: Accumulate each element.  The supplied reduction
147	>	* function cannot rely on ordering (more formally, it should be
148	>	* both associative and commutative).  There are five variants:
149	>	*
150	>	* <ul>
151	>	*
152	>	* <li> Plain reductions. (There is not a form of this method for
153	>	* (key, value) function arguments since there is no corresponding
154	>	* return type.)</li>
155	>	*
156	>	* <li> Mapped reductions that accumulate the results of a given
157	>	* function applied to each element.</li>
158	>	*
159	>	* <li> Reductions to scalar doubles, longs, and ints, using a
160	>	* given basis value.</li>
161	>	*
162	>	* </ul>
163	>	* </li>
164	>	* </ul>
165	>	*
166	>	* <p>These bulk operations accept a {@code parallelismThreshold}
167	>	* argument. Methods proceed sequentially if the current map size is
168	>	* estimated to be less than the given threshold. Using a value of
169	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
170	>	* of {@code 1} results in maximal parallelism by partitioning into
171	>	* enough subtasks to fully utilize the {@link
172	>	* ForkJoinPool#commonPool()} that is used for all parallel
173	>	* computations. Normally, you would initially choose one of these
174	>	* extreme values, and then measure performance of using in-between
175	>	* values that trade off overhead versus throughput.
176	>	*
177	>	* <p>The concurrency properties of bulk operations follow
178	>	* from those of ConcurrentHashMap: Any non-null result returned
179	>	* from {@code get(key)} and related access methods bears a
180	>	* happens-before relation with the associated insertion or
181	>	* update.  The result of any bulk operation reflects the
182	>	* composition of these per-element relations (but is not
183	>	* necessarily atomic with respect to the map as a whole unless it
184	>	* is somehow known to be quiescent).  Conversely, because keys
185	>	* and values in the map are never null, null serves as a reliable
186	>	* atomic indicator of the current lack of any result.  To
187	>	* maintain this property, null serves as an implicit basis for
188	>	* all non-scalar reduction operations. For the double, long, and
189	>	* int versions, the basis should be one that, when combined with
190	>	* any other value, returns that other value (more formally, it
191	>	* should be the identity element for the reduction). Most common
192	>	* reductions have these properties; for example, computing a sum
193	>	* with basis 0 or a minimum with basis MAX_VALUE.
194	>	*
195	>	* <p>Search and transformation functions provided as arguments
196	>	* should similarly return null to indicate the lack of any result
197	>	* (in which case it is not used). In the case of mapped
198	>	* reductions, this also enables transformations to serve as
199	>	* filters, returning null (or, in the case of primitive
200	>	* specializations, the identity basis) if the element should not
201	>	* be combined. You can create compound transformations and
202	>	* filterings by composing them yourself under this "null means
203	>	* there is nothing there now" rule before using them in search or
204	>	* reduce operations.
205	>	*
206	>	* <p>Methods accepting and/or returning Entry arguments maintain
207	>	* key-value associations. They may be useful for example when
208	>	* finding the key for the greatest value. Note that "plain" Entry
209	>	* arguments can be supplied using {@code new
210	>	* AbstractMap.SimpleEntry(k,v)}.
211	>	*
212	>	* <p>Bulk operations may complete abruptly, throwing an
213	>	* exception encountered in the application of a supplied
214	>	* function. Bear in mind when handling such exceptions that other
215	>	* concurrently executing functions could also have thrown
216	>	* exceptions, or would have done so if the first exception had
217	>	* not occurred.
218	>	*
219	>	* <p>Speedups for parallel compared to sequential forms are common
220	>	* but not guaranteed.  Parallel operations involving brief functions
221	>	* on small maps may execute more slowly than sequential forms if the
222	>	* underlying work to parallelize the computation is more expensive
223	>	* than the computation itself.  Similarly, parallelization may not
224	>	* lead to much actual parallelism if all processors are busy
225	>	* performing unrelated tasks.
226	>	*
227	>	* <p>All arguments to all task methods must be non-null.
228		*
229		* <p>This class is a member of the
230		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 235 | import java.io.ObjectOutputStream;
235		* @param <K> the type of keys maintained by this map
236		* @param <V> the type of mapped values
237		*/
238	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
74	<	implements ConcurrentMap<K, V>, Serializable {
238	>	public class ConcurrentHashMap<K,V> implements ConcurrentMap<K,V>, Serializable {
239		private static final long serialVersionUID = 7249069246763182397L;
240
241		/*
242	<	* The basic strategy is to subdivide the table among Segments,
243	<	* each of which itself is a concurrently readable hash table.  To
244	<	* reduce footprint, all but one segments are constructed only
245	<	* when first needed (see ensureSegment). To maintain visibility
246	<	* in the presence of lazy construction, accesses to segments as
247	<	* well as elements of segment's table must use volatile access,
248	<	* which is done via Unsafe within methods segmentAt etc
249	<	* below. These provide the functionality of AtomicReferenceArrays
250	<	* but reduce the levels of indirection. Additionally,
251	<	* volatile-writes of table elements and entry "next" fields
252	<	* within locked operations use the cheaper "lazySet" forms of
253	<	* writes (via putOrderedObject) because these writes are always
254	<	* followed by lock releases that maintain sequential consistency
255	<	* of table updates.
256	<	*
257	<	* Historical note: The previous version of this class relied
258	<	* heavily on "final" fields, which avoided some volatile reads at
259	<	* the expense of a large initial footprint.  Some remnants of
260	<	* that design (including forced construction of segment 0) exist
261	<	* to ensure serialization compatibility.
242	>	* Overview:
243	>	*
244	>	* The primary design goal of this hash table is to maintain
245	>	* concurrent readability (typically method get(), but also
246	>	* iterators and related methods) while minimizing update
247	>	* contention. Secondary goals are to keep space consumption about
248	>	* the same or better than java.util.HashMap, and to support high
249	>	* initial insertion rates on an empty table by many threads.
250	>	*
251	>	* This map usually acts as a binned (bucketed) hash table.  Each
252	>	* key-value mapping is held in a Node.  Most nodes are instances
253	>	* of the basic Node class with hash, key, value, and next
254	>	* fields. However, various subclasses exist: TreeNodes are
255	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
256	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
257	>	* of bins during resizing. ReservationNodes are used as
258	>	* placeholders while establishing values in computeIfAbsent and
259	>	* related methods.  The types TreeBin, ForwardingNode, and
260	>	* ReservationNode do not hold normal user keys, values, or
261	>	* hashes, and are readily distinguishable during search etc
262	>	* because they have negative hash fields and null key and value
263	>	* fields. (These special nodes are either uncommon or transient,
264	>	* so the impact of carrying around some unused fields is
265	>	* insignificant.)
266	>	*
267	>	* The table is lazily initialized to a power-of-two size upon the
268	>	* first insertion.  Each bin in the table normally contains a
269	>	* list of Nodes (most often, the list has only zero or one Node).
270	>	* Table accesses require volatile/atomic reads, writes, and
271	>	* CASes.  Because there is no other way to arrange this without
272	>	* adding further indirections, we use intrinsics
273	>	* (sun.misc.Unsafe) operations.
274	>	*
275	>	* We use the top (sign) bit of Node hash fields for control
276	>	* purposes -- it is available anyway because of addressing
277	>	* constraints.  Nodes with negative hash fields are specially
278	>	* handled or ignored in map methods.
279	>	*
280	>	* Insertion (via put or its variants) of the first node in an
281	>	* empty bin is performed by just CASing it to the bin.  This is
282	>	* by far the most common case for put operations under most
283	>	* key/hash distributions.  Other update operations (insert,
284	>	* delete, and replace) require locks.  We do not want to waste
285	>	* the space required to associate a distinct lock object with
286	>	* each bin, so instead use the first node of a bin list itself as
287	>	* a lock. Locking support for these locks relies on builtin
288	>	* "synchronized" monitors.
289	>	*
290	>	* Using the first node of a list as a lock does not by itself
291	>	* suffice though: When a node is locked, any update must first
292	>	* validate that it is still the first node after locking it, and
293	>	* retry if not. Because new nodes are always appended to lists,
294	>	* once a node is first in a bin, it remains first until deleted
295	>	* or the bin becomes invalidated (upon resizing).
296	>	*
297	>	* The main disadvantage of per-bin locks is that other update
298	>	* operations on other nodes in a bin list protected by the same
299	>	* lock can stall, for example when user equals() or mapping
300	>	* functions take a long time.  However, statistically, under
301	>	* random hash codes, this is not a common problem.  Ideally, the
302	>	* frequency of nodes in bins follows a Poisson distribution
303	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
304	>	* parameter of about 0.5 on average, given the resizing threshold
305	>	* of 0.75, although with a large variance because of resizing
306	>	* granularity. Ignoring variance, the expected occurrences of
307	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
308	>	* first values are:
309	>	*
310	>	* 0:    0.60653066
311	>	* 1:    0.30326533
312	>	* 2:    0.07581633
313	>	* 3:    0.01263606
314	>	* 4:    0.00157952
315	>	* 5:    0.00015795
316	>	* 6:    0.00001316
317	>	* 7:    0.00000094
318	>	* 8:    0.00000006
319	>	* more: less than 1 in ten million
320	>	*
321	>	* Lock contention probability for two threads accessing distinct
322	>	* elements is roughly 1 / (8 * #elements) under random hashes.
323	>	*
324	>	* Actual hash code distributions encountered in practice
325	>	* sometimes deviate significantly from uniform randomness.  This
326	>	* includes the case when N > (1<<30), so some keys MUST collide.
327	>	* Similarly for dumb or hostile usages in which multiple keys are
328	>	* designed to have identical hash codes or ones that differs only
329	>	* in masked-out high bits. So we use a secondary strategy that
330	>	* applies when the number of nodes in a bin exceeds a
331	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
332	>	* specialized form of red-black trees), bounding search time to
333	>	* O(log N).  Each search step in a TreeBin is at least twice as
334	>	* slow as in a regular list, but given that N cannot exceed
335	>	* (1<<64) (before running out of addresses) this bounds search
336	>	* steps, lock hold times, etc, to reasonable constants (roughly
337	>	* 100 nodes inspected per operation worst case) so long as keys
338	>	* are Comparable (which is very common -- String, Long, etc).
339	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
340	>	* traversal pointers as regular nodes, so can be traversed in
341	>	* iterators in the same way.
342	>	*
343	>	* The table is resized when occupancy exceeds a percentage
344	>	* threshold (nominally, 0.75, but see below).  Any thread
345	>	* noticing an overfull bin may assist in resizing after the
346	>	* initiating thread allocates and sets up the replacement
347	>	* array. However, rather than stalling, these other threads may
348	>	* proceed with insertions etc.  The use of TreeBins shields us
349	>	* from the worst case effects of overfilling while resizes are in
350	>	* progress.  Resizing proceeds by transferring bins, one by one,
351	>	* from the table to the next table. To enable concurrency, the
352	>	* next table must be (incrementally) prefilled with place-holders
353	>	* serving as reverse forwarders to the old table.  Because we are
354	>	* using power-of-two expansion, the elements from each bin must
355	>	* either stay at same index, or move with a power of two
356	>	* offset. We eliminate unnecessary node creation by catching
357	>	* cases where old nodes can be reused because their next fields
358	>	* won't change.  On average, only about one-sixth of them need
359	>	* cloning when a table doubles. The nodes they replace will be
360	>	* garbage collectable as soon as they are no longer referenced by
361	>	* any reader thread that may be in the midst of concurrently
362	>	* traversing table.  Upon transfer, the old table bin contains
363	>	* only a special forwarding node (with hash field "MOVED") that
364	>	* contains the next table as its key. On encountering a
365	>	* forwarding node, access and update operations restart, using
366	>	* the new table.
367	>	*
368	>	* Each bin transfer requires its bin lock, which can stall
369	>	* waiting for locks while resizing. However, because other
370	>	* threads can join in and help resize rather than contend for
371	>	* locks, average aggregate waits become shorter as resizing
372	>	* progresses.  The transfer operation must also ensure that all
373	>	* accessible bins in both the old and new table are usable by any
374	>	* traversal.  This is arranged by proceeding from the last bin
375	>	* (table.length - 1) up towards the first.  Upon seeing a
376	>	* forwarding node, traversals (see class Traverser) arrange to
377	>	* move to the new table without revisiting nodes.  However, to
378	>	* ensure that no intervening nodes are skipped, bin splitting can
379	>	* only begin after the associated reverse-forwarders are in
380	>	* place.
381	>	*
382	>	* The traversal scheme also applies to partial traversals of
383	>	* ranges of bins (via an alternate Traverser constructor)
384	>	* to support partitioned aggregate operations.  Also, read-only
385	>	* operations give up if ever forwarded to a null table, which
386	>	* provides support for shutdown-style clearing, which is also not
387	>	* currently implemented.
388	>	*
389	>	* Lazy table initialization minimizes footprint until first use,
390	>	* and also avoids resizings when the first operation is from a
391	>	* putAll, constructor with map argument, or deserialization.
392	>	* These cases attempt to override the initial capacity settings,
393	>	* but harmlessly fail to take effect in cases of races.
394	>	*
395	>	* The element count is maintained using a specialization of
396	>	* LongAdder. We need to incorporate a specialization rather than
397	>	* just use a LongAdder in order to access implicit
398	>	* contention-sensing that leads to creation of multiple
399	>	* CounterCells.  The counter mechanics avoid contention on
400	>	* updates but can encounter cache thrashing if read too
401	>	* frequently during concurrent access. To avoid reading so often,
402	>	* resizing under contention is attempted only upon adding to a
403	>	* bin already holding two or more nodes. Under uniform hash
404	>	* distributions, the probability of this occurring at threshold
405	>	* is around 13%, meaning that only about 1 in 8 puts check
406	>	* threshold (and after resizing, many fewer do so).
407	>	*
408	>	* TreeBins use a special form of comparison for search and
409	>	* related operations (which is the main reason we cannot use
410	>	* existing collections such as TreeMaps). TreeBins contain
411	>	* Comparable elements, but may contain others, as well as
412	>	* elements that are Comparable but not necessarily Comparable
413	>	* for the same T, so we cannot invoke compareTo among them. To
414	>	* handle this, the tree is ordered primarily by hash value, then
415	>	* by Comparable.compareTo order if applicable.  On lookup at a
416	>	* node, if elements are not comparable or compare as 0 then both
417	>	* left and right children may need to be searched in the case of
418	>	* tied hash values. (This corresponds to the full list search
419	>	* that would be necessary if all elements were non-Comparable and
420	>	* had tied hashes.)  The red-black balancing code is updated from
421	>	* pre-jdk-collections
422	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
423	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
424	>	* Algorithms" (CLR).
425	>	*
426	>	* TreeBins also require an additional locking mechanism.  While
427	>	* list traversal is always possible by readers even during
428	>	* updates, tree traversal is not, mainly because of tree-rotations
429	>	* that may change the root node and/or its linkages.  TreeBins
430	>	* include a simple read-write lock mechanism parasitic on the
431	>	* main bin-synchronization strategy: Structural adjustments
432	>	* associated with an insertion or removal are already bin-locked
433	>	* (and so cannot conflict with other writers) but must wait for
434	>	* ongoing readers to finish. Since there can be only one such
435	>	* waiter, we use a simple scheme using a single "waiter" field to
436	>	* block writers.  However, readers need never block.  If the root
437	>	* lock is held, they proceed along the slow traversal path (via
438	>	* next-pointers) until the lock becomes available or the list is
439	>	* exhausted, whichever comes first. These cases are not fast, but
440	>	* maximize aggregate expected throughput.
441	>	*
442	>	* Maintaining API and serialization compatibility with previous
443	>	* versions of this class introduces several oddities. Mainly: We
444	>	* leave untouched but unused constructor arguments refering to
445	>	* concurrencyLevel. We accept a loadFactor constructor argument,
446	>	* but apply it only to initial table capacity (which is the only
447	>	* time that we can guarantee to honor it.) We also declare an
448	>	* unused "Segment" class that is instantiated in minimal form
449	>	* only when serializing.
450	>	*
451	>	* This file is organized to make things a little easier to follow
452	>	* while reading than they might otherwise: First the main static
453	>	* declarations and utilities, then fields, then main public
454	>	* methods (with a few factorings of multiple public methods into
455	>	* internal ones), then sizing methods, trees, traversers, and
456	>	* bulk operations.
457		*/
458
459		/* ---------------- Constants -------------- */
460
461		/**
462	<	* The default initial capacity for this table,
463	<	* used when not otherwise specified in a constructor.
462	>	* The largest possible table capacity.  This value must be
463	>	* exactly 1<<30 to stay within Java array allocation and indexing
464	>	* bounds for power of two table sizes, and is further required
465	>	* because the top two bits of 32bit hash fields are used for
466	>	* control purposes.
467		*/
468	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
468	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
469
470		/**
471	<	* The default load factor for this table, used when not
472	<	* otherwise specified in a constructor.
471	>	* The default initial table capacity.  Must be a power of 2
472	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
473		*/
474	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
474	>	private static final int DEFAULT_CAPACITY = 16;
475
476		/**
477	<	* The default concurrency level for this table, used when not
478	<	* otherwise specified in a constructor.
477	>	* The largest possible (non-power of two) array size.
478	>	* Needed by toArray and related methods.
479		*/
480	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
480	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
481
482		/**
483	<	* The maximum capacity, used if a higher value is implicitly
484	<	* 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.
483	>	* The default concurrency level for this table. Unused but
484	>	* defined for compatibility with previous versions of this class.
485		*/
486	<	static final int MAXIMUM_CAPACITY = 1 << 30;
486	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
487
488		/**
489	<	* The minimum capacity for per-segment tables.  Must be a power
490	<	* of two, at least two to avoid immediate resizing on next use
491	<	* after lazy construction.
489	>	* The load factor for this table. Overrides of this value in
490	>	* constructors affect only the initial table capacity.  The
491	>	* actual floating point value isn't normally used -- it is
492	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
493	>	* the associated resizing threshold.
494		*/
495	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
495	>	private static final float LOAD_FACTOR = 0.75f;
496
497		/**
498	<	* The maximum number of segments to allow; used to bound
499	<	* constructor arguments. Must be power of two less than 1 << 24.
498	>	* The bin count threshold for using a tree rather than list for a
499	>	* bin.  Bins are converted to trees when adding an element to a
500	>	* bin with at least this many nodes. The value must be greater
501	>	* than 2, and should be at least 8 to mesh with assumptions in
502	>	* tree removal about conversion back to plain bins upon
503	>	* shrinkage.
504		*/
505	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
505	>	static final int TREEIFY_THRESHOLD = 8;
506
507		/**
508	<	* Number of unsynchronized retries in size and containsValue
509	<	* methods before resorting to locking. This is used to avoid
510	<	* unbounded retries if tables undergo continuous modification
145	<	* which would make it impossible to obtain an accurate result.
508	>	* The bin count threshold for untreeifying a (split) bin during a
509	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
510	>	* most 6 to mesh with shrinkage detection under removal.
511		*/
512	<	static final int RETRIES_BEFORE_LOCK = 2;
148	<
149	<	/* ---------------- Fields -------------- */
512	>	static final int UNTREEIFY_THRESHOLD = 6;
513
514		/**
515	<	* Mask value for indexing into segments. The upper bits of a
516	<	* key's hash code are used to choose the segment.
515	>	* The smallest table capacity for which bins may be treeified.
516	>	* (Otherwise the table is resized if too many nodes in a bin.)
517	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
518	>	* conflicts between resizing and treeification thresholds.
519		*/
520	<	final int segmentMask;
520	>	static final int MIN_TREEIFY_CAPACITY = 64;
521
522		/**
523	<	* Shift value for indexing within segments.
523	>	* Minimum number of rebinnings per transfer step. Ranges are
524	>	* subdivided to allow multiple resizer threads.  This value
525	>	* serves as a lower bound to avoid resizers encountering
526	>	* excessive memory contention.  The value should be at least
527	>	* DEFAULT_CAPACITY.
528		*/
529	<	final int segmentShift;
529	>	private static final int MIN_TRANSFER_STRIDE = 16;
530
531	<	/**
532	<	* The segments, each of which is a specialized hash table.
531	>	/*
532	>	* Encodings for Node hash fields. See above for explanation.
533		*/
534	<	final Segment<K,V>[] segments;
535	<
536	<	transient Set<K> keySet;
537	<	transient Set<Map.Entry<K,V>> entrySet;
538	<	transient Collection<V> values;
539	<
540	<	/**
541	<	* ConcurrentHashMap list entry. Note that this is never exported
542	<	* out as a user-visible Map.Entry.
534	>	static final int MOVED     = -1; // hash for forwarding nodes
535	>	static final int TREEBIN   = -2; // hash for roots of trees
536	>	static final int RESERVED  = -3; // hash for transient reservations
537	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
538	>
539	>	/** Number of CPUS, to place bounds on some sizings */
540	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
541	>
542	>	/** For serialization compatibility. */
543	>	private static final ObjectStreamField[] serialPersistentFields = {
544	>	new ObjectStreamField("segments", Segment[].class),
545	>	new ObjectStreamField("segmentMask", Integer.TYPE),
546	>	new ObjectStreamField("segmentShift", Integer.TYPE)
547	>	};
548	>
549	>	/* ---------------- Nodes -------------- */
550	>
551	>	/**
552	>	* Key-value entry.  This class is never exported out as a
553	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
554	>	* MapEntry below), but can be used for read-only traversals used
555	>	* in bulk tasks.  Subclasses of Node with a negative hash field
556	>	* are special, and contain null keys and values (but are never
557	>	* exported).  Otherwise, keys and vals are never null.
558		*/
559	<	static final class HashEntry<K,V> {
559	>	static class Node<K,V> implements Map.Entry<K,V> {
560		final int hash;
561		final K key;
562	<	volatile V value;
563	<	volatile HashEntry<K,V> next;
562	>	volatile V val;
563	>	volatile Node<K,V> next;
564
565	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
565	>	Node(int hash, K key, V val, Node<K,V> next) {
566		this.hash = hash;
567		this.key = key;
568	<	this.value = value;
568	>	this.val = val;
569		this.next = next;
570		}
571
572	+	public final K getKey()       { return key; }
573	+	public final V getValue()     { return val; }
574	+	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
575	+	public final String toString(){ return key + "=" + val; }
576	+	public final V setValue(V value) {
577	+	throw new UnsupportedOperationException();
578	+	}
579	+
580	+	public final boolean equals(Object o) {
581	+	Object k, v, u; Map.Entry<?,?> e;
582	+	return ((o instanceof Map.Entry) &&
583	+	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
584	+	(v = e.getValue()) != null &&
585	+	(k == key || k.equals(key)) &&
586	+	(v == (u = val) || v.equals(u)));
587	+	}
588	+
589		/**
590	<	* Sets next field with volatile write semantics.  (See above
190	<	* about use of putOrderedObject.)
590	>	* Virtualized support for map.get(); overridden in subclasses.
591		*/
592	<	final void setNext(HashEntry<K,V> n) {
593	<	UNSAFE.putOrderedObject(this, nextOffset, n);
592	>	Node<K,V> find(int h, Object k) {
593	>	Node<K,V> e = this;
594	>	if (k != null) {
595	>	do {
596	>	K ek;
597	>	if (e.hash == h &&
598	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
599	>	return e;
600	>	} while ((e = e.next) != null);
601	>	}
602	>	return null;
603		}
604	+	}
605
606	<	// Unsafe mechanics
607	<	static final sun.misc.Unsafe UNSAFE;
608	<	static final long nextOffset;
609	<	static {
610	<	try {
611	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
612	<	Class k = HashEntry.class;
613	<	nextOffset = UNSAFE.objectFieldOffset
614	<	(k.getDeclaredField("next"));
615	<	} catch (Exception e) {
616	<	throw new Error(e);
606	>	/* ---------------- Static utilities -------------- */
607	>
608	>	/**
609	>	* Spreads (XORs) higher bits of hash to lower and also forces top
610	>	* bit to 0. Because the table uses power-of-two masking, sets of
611	>	* hashes that vary only in bits above the current mask will
612	>	* always collide. (Among known examples are sets of Float keys
613	>	* holding consecutive whole numbers in small tables.)  So we
614	>	* apply a transform that spreads the impact of higher bits
615	>	* downward. There is a tradeoff between speed, utility, and
616	>	* quality of bit-spreading. Because many common sets of hashes
617	>	* are already reasonably distributed (so don't benefit from
618	>	* spreading), and because we use trees to handle large sets of
619	>	* collisions in bins, we just XOR some shifted bits in the
620	>	* cheapest possible way to reduce systematic lossage, as well as
621	>	* to incorporate impact of the highest bits that would otherwise
622	>	* never be used in index calculations because of table bounds.
623	>	*/
624	>	static final int spread(int h) {
625	>	return (h ^ (h >>> 16)) & HASH_BITS;
626	>	}
627	>
628	>	/**
629	>	* Returns a power of two table size for the given desired capacity.
630	>	* See Hackers Delight, sec 3.2
631	>	*/
632	>	private static final int tableSizeFor(int c) {
633	>	int n = c - 1;
634	>	n |= n >>> 1;
635	>	n |= n >>> 2;
636	>	n |= n >>> 4;
637	>	n |= n >>> 8;
638	>	n |= n >>> 16;
639	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
640	>	}
641	>
642	>	/**
643	>	* Returns x's Class if it is of the form "class C implements
644	>	* Comparable<C>", else null.
645	>	*/
646	>	static Class<?> comparableClassFor(Object x) {
647	>	if (x instanceof Comparable) {
648	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
649	>	if ((c = x.getClass()) == String.class) // bypass checks
650	>	return c;
651	>	if ((ts = c.getGenericInterfaces()) != null) {
652	>	for (int i = 0; i < ts.length; ++i) {
653	>	if (((t = ts[i]) instanceof ParameterizedType) &&
654	>	((p = (ParameterizedType)t).getRawType() ==
655	>	Comparable.class) &&
656	>	(as = p.getActualTypeArguments()) != null &&
657	>	as.length == 1 && as[0] == c) // type arg is c
658	>	return c;
659	>	}
660		}
661		}
662	+	return null;
663		}
664
665		/**
666	<	* Gets the ith element of given table (if nonnull) with volatile
667	<	* read semantics. Note: This is manually integrated into a few
668	<	* performance-sensitive methods to reduce call overhead.
666	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
667	>	* class), else 0.
668	>	*/
669	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
670	>	static int compareComparables(Class<?> kc, Object k, Object x) {
671	>	return (x == null || x.getClass() != kc ? 0 :
672	>	((Comparable)k).compareTo(x));
673	>	}
674	>
675	>	/* ---------------- Table element access -------------- */
676	>
677	>	/*
678	>	* Volatile access methods are used for table elements as well as
679	>	* elements of in-progress next table while resizing.  All uses of
680	>	* the tab arguments must be null checked by callers.  All callers
681	>	* also paranoically precheck that tab's length is not zero (or an
682	>	* equivalent check), thus ensuring that any index argument taking
683	>	* the form of a hash value anded with (length - 1) is a valid
684	>	* index.  Note that, to be correct wrt arbitrary concurrency
685	>	* errors by users, these checks must operate on local variables,
686	>	* which accounts for some odd-looking inline assignments below.
687	>	* Note that calls to setTabAt always occur within locked regions,
688	>	* and so in principle require only release ordering, not need
689	>	* full volatile semantics, but are currently coded as volatile
690	>	* writes to be conservative.
691		*/
692	+
693		@SuppressWarnings("unchecked")
694	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
695	<	return (tab == null) ? null :
696	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
697	<	(tab, ((long)i << TSHIFT) + TBASE);
694	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
695	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
696	>	}
697	>
698	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
699	>	Node<K,V> c, Node<K,V> v) {
700	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
701	>	}
702	>
703	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
704	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
705		}
706
707	+	/* ---------------- Fields -------------- */
708	+
709	+	/**
710	+	* The array of bins. Lazily initialized upon first insertion.
711	+	* Size is always a power of two. Accessed directly by iterators.
712	+	*/
713	+	transient volatile Node<K,V>[] table;
714	+
715	+	/**
716	+	* The next table to use; non-null only while resizing.
717	+	*/
718	+	private transient volatile Node<K,V>[] nextTable;
719	+
720	+	/**
721	+	* Base counter value, used mainly when there is no contention,
722	+	* but also as a fallback during table initialization
723	+	* races. Updated via CAS.
724	+	*/
725	+	private transient volatile long baseCount;
726	+
727	+	/**
728	+	* Table initialization and resizing control.  When negative, the
729	+	* table is being initialized or resized: -1 for initialization,
730	+	* else -(1 + the number of active resizing threads).  Otherwise,
731	+	* when table is null, holds the initial table size to use upon
732	+	* creation, or 0 for default. After initialization, holds the
733	+	* next element count value upon which to resize the table.
734	+	*/
735	+	private transient volatile int sizeCtl;
736	+
737	+	/**
738	+	* The next table index (plus one) to split while resizing.
739	+	*/
740	+	private transient volatile int transferIndex;
741	+
742	+	/**
743	+	* The least available table index to split while resizing.
744	+	*/
745	+	private transient volatile int transferOrigin;
746	+
747	+	/**
748	+	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
749	+	*/
750	+	private transient volatile int cellsBusy;
751	+
752	+	/**
753	+	* Table of counter cells. When non-null, size is a power of 2.
754	+	*/
755	+	private transient volatile CounterCell[] counterCells;
756	+
757	+	// views
758	+	private transient KeySetView<K,V> keySet;
759	+	private transient ValuesView<K,V> values;
760	+	private transient EntrySetView<K,V> entrySet;
761	+
762	+
763	+	/* ---------------- Public operations -------------- */
764	+
765		/**
766	<	* Sets the ith element of given table, with volatile write
225	<	* semantics. (See above about use of putOrderedObject.)
766	>	* Creates a new, empty map with the default initial table size (16).
767		*/
768	<	static final <K,V> void setEntryAt(HashEntry<K,V>[] tab, int i,
228	<	HashEntry<K,V> e) {
229	<	UNSAFE.putOrderedObject(tab, ((long)i << TSHIFT) + TBASE, e);
768	>	public ConcurrentHashMap() {
769		}
770
771		/**
772	<	* Applies a supplemental hash function to a given hashCode, which
773	<	* defends against poor quality hash functions.  This is critical
774	<	* because ConcurrentHashMap uses power-of-two length hash tables,
775	<	* that otherwise encounter collisions for hashCodes that do not
776	<	* differ in lower or upper bits.
772	>	* Creates a new, empty map with an initial table size
773	>	* accommodating the specified number of elements without the need
774	>	* to dynamically resize.
775	>	*
776	>	* @param initialCapacity The implementation performs internal
777	>	* sizing to accommodate this many elements.
778	>	* @throws IllegalArgumentException if the initial capacity of
779	>	* elements is negative
780		*/
781	<	private static int hash(int h) {
782	<	// Spread bits to regularize both segment and index locations,
783	<	// using variant of single-word Wang/Jenkins hash.
784	<	h += (h <<  15) ^ 0xffffcd7d;
785	<	h ^= (h >>> 10);
786	<	h += (h <<   3);
787	<	h ^= (h >>>  6);
246	<	h += (h <<   2) + (h << 14);
247	<	return h ^ (h >>> 16);
781	>	public ConcurrentHashMap(int initialCapacity) {
782	>	if (initialCapacity < 0)
783	>	throw new IllegalArgumentException();
784	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
785	>	MAXIMUM_CAPACITY :
786	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
787	>	this.sizeCtl = cap;
788		}
789
790		/**
791	<	* Segments are specialized versions of hash tables.  This
792	<	* subclasses from ReentrantLock opportunistically, just to
793	<	* simplify some locking and avoid separate construction.
791	>	* Creates a new map with the same mappings as the given map.
792	>	*
793	>	* @param m the map
794		*/
795	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
796	<	/*
797	<	* Segments maintain a table of entry lists that are always
798	<	* 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	<	*/
795	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
796	>	this.sizeCtl = DEFAULT_CAPACITY;
797	>	putAll(m);
798	>	}
799
800	<	private static final long serialVersionUID = 2249069246763182397L;
800	>	/**
801	>	* Creates a new, empty map with an initial table size based on
802	>	* the given number of elements ({@code initialCapacity}) and
803	>	* initial table density ({@code loadFactor}).
804	>	*
805	>	* @param initialCapacity the initial capacity. The implementation
806	>	* performs internal sizing to accommodate this many elements,
807	>	* given the specified load factor.
808	>	* @param loadFactor the load factor (table density) for
809	>	* establishing the initial table size
810	>	* @throws IllegalArgumentException if the initial capacity of
811	>	* elements is negative or the load factor is nonpositive
812	>	*
813	>	* @since 1.6
814	>	*/
815	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
816	>	this(initialCapacity, loadFactor, 1);
817	>	}
818
819	<	/**
820	<	* The maximum number of times to tryLock in a prescan before
821	<	* possibly blocking on acquire in preparation for a locked
822	<	* segment operation. On multiprocessors, using a bounded
823	<	* number of retries maintains cache acquired while locating
824	<	* nodes.
825	<	*/
826	<	static final int MAX_SCAN_RETRIES =
827	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
819	>	/**
820	>	* Creates a new, empty map with an initial table size based on
821	>	* the given number of elements ({@code initialCapacity}), table
822	>	* density ({@code loadFactor}), and number of concurrently
823	>	* updating threads ({@code concurrencyLevel}).
824	>	*
825	>	* @param initialCapacity the initial capacity. The implementation
826	>	* performs internal sizing to accommodate this many elements,
827	>	* given the specified load factor.
828	>	* @param loadFactor the load factor (table density) for
829	>	* establishing the initial table size
830	>	* @param concurrencyLevel the estimated number of concurrently
831	>	* updating threads. The implementation may use this value as
832	>	* a sizing hint.
833	>	* @throws IllegalArgumentException if the initial capacity is
834	>	* negative or the load factor or concurrencyLevel are
835	>	* nonpositive
836	>	*/
837	>	public ConcurrentHashMap(int initialCapacity,
838	>	float loadFactor, int concurrencyLevel) {
839	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
840	>	throw new IllegalArgumentException();
841	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
842	>	initialCapacity = concurrencyLevel;   // as estimated threads
843	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
844	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
845	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
846	>	this.sizeCtl = cap;
847	>	}
848
849	<	/**
295	<	* The per-segment table. Elements are accessed via
296	<	* entryAt/setEntryAt providing volatile semantics.
297	<	*/
298	<	transient volatile HashEntry<K,V>[] table;
849	>	// Original (since JDK1.2) Map methods
850
851	<	/**
852	<	* The number of elements. Accessed only either within locks
853	<	* or among other volatile reads that maintain visibility.
854	<	*/
855	<	transient int count;
851	>	/**
852	>	* {@inheritDoc}
853	>	*/
854	>	public int size() {
855	>	long n = sumCount();
856	>	return ((n < 0L) ? 0 :
857	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
858	>	(int)n);
859	>	}
860
861	<	/**
862	<	* The total number of mutative operations in this segment.
863	<	* Even though this may overflows 32 bits, it provides
864	<	* sufficient accuracy for stability checks in CHM isEmpty()
865	<	* and size() methods.  Accessed only either within locks or
866	<	* among other volatile reads that maintain visibility.
312	<	*/
313	<	transient int modCount;
861	>	/**
862	>	* {@inheritDoc}
863	>	*/
864	>	public boolean isEmpty() {
865	>	return sumCount() <= 0L; // ignore transient negative values
866	>	}
867
868	<	/**
869	<	* The table is rehashed when its size exceeds this threshold.
870	<	* (The value of this field is always <tt>(int)(capacity *
871	<	* loadFactor)</tt>.)
872	<	*/
873	<	transient int threshold;
868	>	/**
869	>	* Returns the value to which the specified key is mapped,
870	>	* or {@code null} if this map contains no mapping for the key.
871	>	*
872	>	* <p>More formally, if this map contains a mapping from a key
873	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
874	>	* then this method returns {@code v}; otherwise it returns
875	>	* {@code null}.  (There can be at most one such mapping.)
876	>	*
877	>	* @throws NullPointerException if the specified key is null
878	>	*/
879	>	public V get(Object key) {
880	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
881	>	int h = spread(key.hashCode());
882	>	if ((tab = table) != null && (n = tab.length) > 0 &&
883	>	(e = tabAt(tab, (n - 1) & h)) != null) {
884	>	if ((eh = e.hash) == h) {
885	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
886	>	return e.val;
887	>	}
888	>	else if (eh < 0)
889	>	return (p = e.find(h, key)) != null ? p.val : null;
890	>	while ((e = e.next) != null) {
891	>	if (e.hash == h &&
892	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
893	>	return e.val;
894	>	}
895	>	}
896	>	return null;
897	>	}
898
899	<	/**
900	<	* The load factor for the hash table.  Even though this value
901	<	* is same for all segments, it is replicated to avoid needing
902	<	* links to outer object.
903	<	* @serial
904	<	*/
905	<	final float loadFactor;
899	>	/**
900	>	* Tests if the specified object is a key in this table.
901	>	*
902	>	* @param  key possible key
903	>	* @return {@code true} if and only if the specified object
904	>	*         is a key in this table, as determined by the
905	>	*         {@code equals} method; {@code false} otherwise
906	>	* @throws NullPointerException if the specified key is null
907	>	*/
908	>	public boolean containsKey(Object key) {
909	>	return get(key) != null;
910	>	}
911
912	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
913	<	this.loadFactor = lf;
914	<	this.threshold = threshold;
915	<	this.table = tab;
912	>	/**
913	>	* Returns {@code true} if this map maps one or more keys to the
914	>	* specified value. Note: This method may require a full traversal
915	>	* of the map, and is much slower than method {@code containsKey}.
916	>	*
917	>	* @param value value whose presence in this map is to be tested
918	>	* @return {@code true} if this map maps one or more keys to the
919	>	*         specified value
920	>	* @throws NullPointerException if the specified value is null
921	>	*/
922	>	public boolean containsValue(Object value) {
923	>	if (value == null)
924	>	throw new NullPointerException();
925	>	Node<K,V>[] t;
926	>	if ((t = table) != null) {
927	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
928	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
929	>	V v;
930	>	if ((v = p.val) == value || (v != null && value.equals(v)))
931	>	return true;
932	>	}
933		}
934	+	return false;
935	+	}
936
937	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
938	<	HashEntry<K,V> node = tryLock() ? null :
939	<	scanAndLockForPut(key, hash, value);
940	<	V oldValue;
941	<	try {
942	<	HashEntry<K,V>[] tab = table;
943	<	int index = (tab.length - 1) & hash;
944	<	HashEntry<K,V> first = entryAt(tab, index);
945	<	for (HashEntry<K,V> e = first;;) {
946	<	if (e != null) {
947	<	K k;
948	<	if ((k = e.key) == key ||
949	<	(e.hash == hash && key.equals(k))) {
950	<	oldValue = e.value;
951	<	if (!onlyIfAbsent) {
952	<	e.value = value;
953	<	++modCount;
937	>	/**
938	>	* Maps the specified key to the specified value in this table.
939	>	* Neither the key nor the value can be null.
940	>	*
941	>	* <p>The value can be retrieved by calling the {@code get} method
942	>	* with a key that is equal to the original key.
943	>	*
944	>	* @param key key with which the specified value is to be associated
945	>	* @param value value to be associated with the specified key
946	>	* @return the previous value associated with {@code key}, or
947	>	*         {@code null} if there was no mapping for {@code key}
948	>	* @throws NullPointerException if the specified key or value is null
949	>	*/
950	>	public V put(K key, V value) {
951	>	return putVal(key, value, false);
952	>	}
953	>
954	>	/** Implementation for put and putIfAbsent */
955	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
956	>	if (key == null || value == null) throw new NullPointerException();
957	>	int hash = spread(key.hashCode());
958	>	int binCount = 0;
959	>	for (Node<K,V>[] tab = table;;) {
960	>	Node<K,V> f; int n, i, fh;
961	>	if (tab == null || (n = tab.length) == 0)
962	>	tab = initTable();
963	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
964	>	if (casTabAt(tab, i, null,
965	>	new Node<K,V>(hash, key, value, null)))
966	>	break;                   // no lock when adding to empty bin
967	>	}
968	>	else if ((fh = f.hash) == MOVED)
969	>	tab = helpTransfer(tab, f);
970	>	else {
971	>	V oldVal = null;
972	>	synchronized (f) {
973	>	if (tabAt(tab, i) == f) {
974	>	if (fh >= 0) {
975	>	binCount = 1;
976	>	for (Node<K,V> e = f;; ++binCount) {
977	>	K ek;
978	>	if (e.hash == hash &&
979	>	((ek = e.key) == key ||
980	>	(ek != null && key.equals(ek)))) {
981	>	oldVal = e.val;
982	>	if (!onlyIfAbsent)
983	>	e.val = value;
984	>	break;
985	>	}
986	>	Node<K,V> pred = e;
987	>	if ((e = e.next) == null) {
988	>	pred.next = new Node<K,V>(hash, key,
989	>	value, null);
990	>	break;
991	>	}
992	>	}
993	>	}
994	>	else if (f instanceof TreeBin) {
995	>	Node<K,V> p;
996	>	binCount = 2;
997	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
998	>	value)) != null) {
999	>	oldVal = p.val;
1000	>	if (!onlyIfAbsent)
1001	>	p.val = value;
1002		}
354	–	break;
1003		}
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;
1004		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
1005		}
1006	<	else if (++retries > MAX_SCAN_RETRIES) {
1007	<	lock();
1006	>	if (binCount != 0) {
1007	>	if (binCount >= TREEIFY_THRESHOLD)
1008	>	treeifyBin(tab, i);
1009	>	if (oldVal != null)
1010	>	return oldVal;
1011		break;
1012		}
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	–	}
1013		}
1014		}
1015	+	addCount(1L, binCount);
1016	+	return null;
1017	+	}
1018
1019	<	/**
1020	<	* Remove; match on key only if value null, else match both.
1021	<	*/
1022	<	final V remove(Object key, int hash, Object value) {
1023	<	if (!tryLock())
1024	<	scanAndLock(key, hash);
1025	<	V oldValue = null;
1026	<	try {
1027	<	HashEntry<K,V>[] tab = table;
1028	<	int index = (tab.length - 1) & hash;
1029	<	HashEntry<K,V> e = entryAt(tab, index);
1030	<	HashEntry<K,V> pred = null;
1031	<	while (e != null) {
1032	<	K k;
1033	<	HashEntry<K,V> next = e.next;
1034	<	if ((k = e.key) == key ||
1035	<	(e.hash == hash && key.equals(k))) {
1036	<	V v = e.value;
1037	<	if (value == null || value == v || value.equals(v)) {
1038	<	if (pred == null)
1039	<	setEntryAt(tab, index, next);
1040	<	else
1041	<	pred.setNext(next);
1042	<	++modCount;
1043	<	--count;
1044	<	oldValue = v;
1019	>	/**
1020	>	* Copies all of the mappings from the specified map to this one.
1021	>	* These mappings replace any mappings that this map had for any of the
1022	>	* keys currently in the specified map.
1023	>	*
1024	>	* @param m mappings to be stored in this map
1025	>	*/
1026	>	public void putAll(Map<? extends K, ? extends V> m) {
1027	>	tryPresize(m.size());
1028	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1029	>	putVal(e.getKey(), e.getValue(), false);
1030	>	}
1031	>
1032	>	/**
1033	>	* Removes the key (and its corresponding value) from this map.
1034	>	* This method does nothing if the key is not in the map.
1035	>	*
1036	>	* @param  key the key that needs to be removed
1037	>	* @return the previous value associated with {@code key}, or
1038	>	*         {@code null} if there was no mapping for {@code key}
1039	>	* @throws NullPointerException if the specified key is null
1040	>	*/
1041	>	public V remove(Object key) {
1042	>	return replaceNode(key, null, null);
1043	>	}
1044	>
1045	>	/**
1046	>	* Implementation for the four public remove/replace methods:
1047	>	* Replaces node value with v, conditional upon match of cv if
1048	>	* non-null.  If resulting value is null, delete.
1049	>	*/
1050	>	final V replaceNode(Object key, V value, Object cv) {
1051	>	int hash = spread(key.hashCode());
1052	>	for (Node<K,V>[] tab = table;;) {
1053	>	Node<K,V> f; int n, i, fh;
1054	>	if (tab == null || (n = tab.length) == 0 ||
1055	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1056	>	break;
1057	>	else if ((fh = f.hash) == MOVED)
1058	>	tab = helpTransfer(tab, f);
1059	>	else {
1060	>	V oldVal = null;
1061	>	boolean validated = false;
1062	>	synchronized (f) {
1063	>	if (tabAt(tab, i) == f) {
1064	>	if (fh >= 0) {
1065	>	validated = true;
1066	>	for (Node<K,V> e = f, pred = null;;) {
1067	>	K ek;
1068	>	if (e.hash == hash &&
1069	>	((ek = e.key) == key ||
1070	>	(ek != null && key.equals(ek)))) {
1071	>	V ev = e.val;
1072	>	if (cv == null || cv == ev ||
1073	>	(ev != null && cv.equals(ev))) {
1074	>	oldVal = ev;
1075	>	if (value != null)
1076	>	e.val = value;
1077	>	else if (pred != null)
1078	>	pred.next = e.next;
1079	>	else
1080	>	setTabAt(tab, i, e.next);
1081	>	}
1082	>	break;
1083	>	}
1084	>	pred = e;
1085	>	if ((e = e.next) == null)
1086	>	break;
1087	>	}
1088	>	}
1089	>	else if (f instanceof TreeBin) {
1090	>	validated = true;
1091	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1092	>	TreeNode<K,V> r, p;
1093	>	if ((r = t.root) != null &&
1094	>	(p = r.findTreeNode(hash, key, null)) != null) {
1095	>	V pv = p.val;
1096	>	if (cv == null || cv == pv ||
1097	>	(pv != null && cv.equals(pv))) {
1098	>	oldVal = pv;
1099	>	if (value != null)
1100	>	p.val = value;
1101	>	else if (t.removeTreeNode(p))
1102	>	setTabAt(tab, i, untreeify(t.first));
1103	>	}
1104	>	}
1105		}
546	–	break;
1106		}
548	–	pred = e;
549	–	e = next;
1107		}
1108	<	} finally {
1109	<	unlock();
1110	<	}
1111	<	return oldValue;
1112	<	}
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;
1108	>	if (validated) {
1109	>	if (oldVal != null) {
1110	>	if (value == null)
1111	>	addCount(-1L, -1);
1112	>	return oldVal;
1113		}
1114	+	break;
1115		}
575	–	} finally {
576	–	unlock();
1116		}
578	–	return replaced;
1117		}
1118	+	return null;
1119	+	}
1120
1121	<	final V replace(K key, int hash, V value) {
1122	<	if (!tryLock())
1123	<	scanAndLock(key, hash);
1124	<	V oldValue = null;
1125	<	try {
1126	<	HashEntry<K,V> e;
1127	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1128	<	K k;
1129	<	if ((k = e.key) == key ||
1130	<	(e.hash == hash && key.equals(k))) {
1131	<	oldValue = e.value;
1132	<	e.value = value;
1133	<	++modCount;
1134	<	break;
1121	>	/**
1122	>	* Removes all of the mappings from this map.
1123	>	*/
1124	>	public void clear() {
1125	>	long delta = 0L; // negative number of deletions
1126	>	int i = 0;
1127	>	Node<K,V>[] tab = table;
1128	>	while (tab != null && i < tab.length) {
1129	>	int fh;
1130	>	Node<K,V> f = tabAt(tab, i);
1131	>	if (f == null)
1132	>	++i;
1133	>	else if ((fh = f.hash) == MOVED) {
1134	>	tab = helpTransfer(tab, f);
1135	>	i = 0; // restart
1136	>	}
1137	>	else {
1138	>	synchronized (f) {
1139	>	if (tabAt(tab, i) == f) {
1140	>	Node<K,V> p = (fh >= 0 ? f :
1141	>	(f instanceof TreeBin) ?
1142	>	((TreeBin<K,V>)f).first : null);
1143	>	while (p != null) {
1144	>	--delta;
1145	>	p = p.next;
1146	>	}
1147	>	setTabAt(tab, i++, null);
1148		}
1149		}
597	–	} finally {
598	–	unlock();
1150		}
600	–	return oldValue;
1151		}
1152	+	if (delta != 0L)
1153	+	addCount(delta, -1);
1154	+	}
1155
1156	<	final void clear() {
1157	<	lock();
1158	<	try {
1159	<	HashEntry<K,V>[] tab = table;
1160	<	for (int i = 0; i < tab.length ; i++)
1161	<	setEntryAt(tab, i, null);
1162	<	++modCount;
1163	<	count = 0;
1164	<	} finally {
1165	<	unlock();
1166	<	}
1167	<	}
1156	>	/**
1157	>	* Returns a {@link Set} view of the keys contained in this map.
1158	>	* The set is backed by the map, so changes to the map are
1159	>	* reflected in the set, and vice-versa. The set supports element
1160	>	* removal, which removes the corresponding mapping from this map,
1161	>	* via the {@code Iterator.remove}, {@code Set.remove},
1162	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1163	>	* operations.  It does not support the {@code add} or
1164	>	* {@code addAll} operations.
1165	>	*
1166	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1167	>	* that will never throw {@link ConcurrentModificationException},
1168	>	* and guarantees to traverse elements as they existed upon
1169	>	* construction of the iterator, and may (but is not guaranteed to)
1170	>	* reflect any modifications subsequent to construction.
1171	>	*
1172	>	* @return the set view
1173	>	*/
1174	>	public KeySetView<K,V> keySet() {
1175	>	KeySetView<K,V> ks;
1176	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1177		}
1178
1179	<	// Accessing segments
1179	>	/**
1180	>	* Returns a {@link Collection} view of the values contained in this map.
1181	>	* The collection is backed by the map, so changes to the map are
1182	>	* reflected in the collection, and vice-versa.  The collection
1183	>	* supports element removal, which removes the corresponding
1184	>	* mapping from this map, via the {@code Iterator.remove},
1185	>	* {@code Collection.remove}, {@code removeAll},
1186	>	* {@code retainAll}, and {@code clear} operations.  It does not
1187	>	* support the {@code add} or {@code addAll} operations.
1188	>	*
1189	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1190	>	* that will never throw {@link ConcurrentModificationException},
1191	>	* and guarantees to traverse elements as they existed upon
1192	>	* construction of the iterator, and may (but is not guaranteed to)
1193	>	* reflect any modifications subsequent to construction.
1194	>	*
1195	>	* @return the collection view
1196	>	*/
1197	>	public Collection<V> values() {
1198	>	ValuesView<K,V> vs;
1199	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1200	>	}
1201
1202		/**
1203	<	* Gets the jth element of given segment array (if nonnull) with
1204	<	* volatile element access semantics via Unsafe. (The null check
1205	<	* can trigger harmlessly only during deserialization.) Note:
1206	<	* because each element of segments array is set only once (using
1207	<	* fully ordered writes), some performance-sensitive methods rely
1208	<	* on this method only as a recheck upon null reads.
1203	>	* Returns a {@link Set} view of the mappings contained in this map.
1204	>	* The set is backed by the map, so changes to the map are
1205	>	* reflected in the set, and vice-versa.  The set supports element
1206	>	* removal, which removes the corresponding mapping from the map,
1207	>	* via the {@code Iterator.remove}, {@code Set.remove},
1208	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1209	>	* operations.
1210	>	*
1211	>	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1212	>	* that will never throw {@link ConcurrentModificationException},
1213	>	* and guarantees to traverse elements as they existed upon
1214	>	* construction of the iterator, and may (but is not guaranteed to)
1215	>	* reflect any modifications subsequent to construction.
1216	>	*
1217	>	* @return the set view
1218		*/
1219	<	@SuppressWarnings("unchecked")
1220	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1221	<	long u = (j << SSHIFT) + SBASE;
630	<	return ss == null ? null :
631	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1219	>	public Set<Map.Entry<K,V>> entrySet() {
1220	>	EntrySetView<K,V> es;
1221	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1222		}
1223
1224		/**
1225	<	* Returns the segment for the given index, creating it and
1226	<	* recording in segment table (via CAS) if not already present.
1225	>	* Returns the hash code value for this {@link Map}, i.e.,
1226	>	* the sum of, for each key-value pair in the map,
1227	>	* {@code key.hashCode() ^ value.hashCode()}.
1228		*
1229	<	* @param k the index
639	<	* @return the segment
1229	>	* @return the hash code value for this map
1230		*/
1231	<	@SuppressWarnings("unchecked")
1232	<	private Segment<K,V> ensureSegment(int k) {
1233	<	final Segment<K,V>[] ss = this.segments;
1234	<	long u = (k << SSHIFT) + SBASE; // raw offset
1235	<	Segment<K,V> seg;
1236	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1237	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1238	<	int cap = proto.table.length;
1239	<	float lf = proto.loadFactor;
1240	<	int threshold = (int)(cap * lf);
1241	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry[cap];
1242	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1243	<	== null) { // recheck
1244	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1245	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1246	<	== null) {
1247	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1248	<	break;
1249	<	}
1231	>	public int hashCode() {
1232	>	int h = 0;
1233	>	Node<K,V>[] t;
1234	>	if ((t = table) != null) {
1235	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1236	>	for (Node<K,V> p; (p = it.advance()) != null; )
1237	>	h += p.key.hashCode() ^ p.val.hashCode();
1238	>	}
1239	>	return h;
1240	>	}
1241	>
1242	>	/**
1243	>	* Returns a string representation of this map.  The string
1244	>	* representation consists of a list of key-value mappings (in no
1245	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1246	>	* mappings are separated by the characters {@code ", "} (comma
1247	>	* and space).  Each key-value mapping is rendered as the key
1248	>	* followed by an equals sign ("{@code =}") followed by the
1249	>	* associated value.
1250	>	*
1251	>	* @return a string representation of this map
1252	>	*/
1253	>	public String toString() {
1254	>	Node<K,V>[] t;
1255	>	int f = (t = table) == null ? 0 : t.length;
1256	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1257	>	StringBuilder sb = new StringBuilder();
1258	>	sb.append('{');
1259	>	Node<K,V> p;
1260	>	if ((p = it.advance()) != null) {
1261	>	for (;;) {
1262	>	K k = p.key;
1263	>	V v = p.val;
1264	>	sb.append(k == this ? "(this Map)" : k);
1265	>	sb.append('=');
1266	>	sb.append(v == this ? "(this Map)" : v);
1267	>	if ((p = it.advance()) == null)
1268	>	break;
1269	>	sb.append(',').append(' ');
1270		}
1271		}
1272	<	return seg;
1272	>	return sb.append('}').toString();
1273		}
1274
665	–	// Hash-based segment and entry accesses
666	–
1275		/**
1276	<	* Gets the segment for the given hash code.
1276	>	* Compares the specified object with this map for equality.
1277	>	* Returns {@code true} if the given object is a map with the same
1278	>	* mappings as this map.  This operation may return misleading
1279	>	* results if either map is concurrently modified during execution
1280	>	* of this method.
1281	>	*
1282	>	* @param o object to be compared for equality with this map
1283	>	* @return {@code true} if the specified object is equal to this map
1284		*/
1285	<	@SuppressWarnings("unchecked")
1286	<	private Segment<K,V> segmentForHash(int h) {
1287	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1288	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1285	>	public boolean equals(Object o) {
1286	>	if (o != this) {
1287	>	if (!(o instanceof Map))
1288	>	return false;
1289	>	Map<?,?> m = (Map<?,?>) o;
1290	>	Node<K,V>[] t;
1291	>	int f = (t = table) == null ? 0 : t.length;
1292	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1293	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1294	>	V val = p.val;
1295	>	Object v = m.get(p.key);
1296	>	if (v == null || (v != val && !v.equals(val)))
1297	>	return false;
1298	>	}
1299	>	for (Map.Entry<?,?> e : m.entrySet()) {
1300	>	Object mk, mv, v;
1301	>	if ((mk = e.getKey()) == null ||
1302	>	(mv = e.getValue()) == null ||
1303	>	(v = get(mk)) == null ||
1304	>	(mv != v && !mv.equals(v)))
1305	>	return false;
1306	>	}
1307	>	}
1308	>	return true;
1309		}
1310
1311		/**
1312	<	* Gets the table entry for the given segment and hash code.
1312	>	* Stripped-down version of helper class used in previous version,
1313	>	* declared for the sake of serialization compatibility
1314		*/
1315	<	@SuppressWarnings("unchecked")
1316	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1317	<	HashEntry<K,V>[] tab;
1318	<	return (seg == null || (tab = seg.table) == null) ? null :
683	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
684	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1315	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1316	>	private static final long serialVersionUID = 2249069246763182397L;
1317	>	final float loadFactor;
1318	>	Segment(float lf) { this.loadFactor = lf; }
1319		}
1320
687	–	/* ---------------- Public operations -------------- */
688	–
1321		/**
1322	<	* Creates a new, empty map with the specified initial
1323	<	* capacity, load factor and concurrency level.
1324	<	*
1325	<	* @param initialCapacity the initial capacity. The implementation
1326	<	* performs internal sizing to accommodate this many elements.
1327	<	* @param loadFactor  the load factor threshold, used to control resizing.
1328	<	* 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.
1322	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1323	>	* stream (i.e., serializes it).
1324	>	* @param s the stream
1325	>	* @serialData
1326	>	* the key (Object) and value (Object)
1327	>	* for each key-value mapping, followed by a null pair.
1328	>	* The key-value mappings are emitted in no particular order.
1329		*/
1330	<	@SuppressWarnings("unchecked")
1331	<	public ConcurrentHashMap(int initialCapacity,
1332	<	float loadFactor, int concurrencyLevel) {
1333	<	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
1330	>	private void writeObject(java.io.ObjectOutputStream s)
1331	>	throws java.io.IOException {
1332	>	// For serialization compatibility
1333	>	// Emulate segment calculation from previous version of this class
1334		int sshift = 0;
1335		int ssize = 1;
1336	<	while (ssize < concurrencyLevel) {
1336	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1337		++sshift;
1338		ssize <<= 1;
1339		}
1340	<	this.segmentShift = 32 - sshift;
1341	<	this.segmentMask = ssize - 1;
1342	<	if (initialCapacity > MAXIMUM_CAPACITY)
1343	<	initialCapacity = MAXIMUM_CAPACITY;
1344	<	int c = initialCapacity / ssize;
1345	<	if (c * ssize < initialCapacity)
1346	<	++c;
1347	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1348	<	while (cap < c)
1349	<	cap <<= 1;
1350	<	// create segments and segments[0]
1351	<	Segment<K,V> s0 =
1352	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1353	<	(HashEntry<K,V>[])new HashEntry[cap]);
1354	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment[ssize];
1355	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1356	<	this.segments = ss;
1340	>	int segmentShift = 32 - sshift;
1341	>	int segmentMask = ssize - 1;
1342	>	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1343	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1344	>	for (int i = 0; i < segments.length; ++i)
1345	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1346	>	s.putFields().put("segments", segments);
1347	>	s.putFields().put("segmentShift", segmentShift);
1348	>	s.putFields().put("segmentMask", segmentMask);
1349	>	s.writeFields();
1350	>
1351	>	Node<K,V>[] t;
1352	>	if ((t = table) != null) {
1353	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1354	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1355	>	s.writeObject(p.key);
1356	>	s.writeObject(p.val);
1357	>	}
1358	>	}
1359	>	s.writeObject(null);
1360	>	s.writeObject(null);
1361	>	segments = null; // throw away
1362		}
1363
1364		/**
1365	<	* Creates a new, empty map with the specified initial capacity
1366	<	* and load factor and with the default concurrencyLevel (16).
1367	<	*
1368	<	* @param initialCapacity The implementation performs internal
1369	<	* sizing to accommodate this many elements.
1370	<	* @param loadFactor  the load factor threshold, used to control resizing.
1371	<	* Resizing may be performed when the average number of elements per
1372	<	* bin exceeds this threshold.
1373	<	* @throws IllegalArgumentException if the initial capacity of
1374	<	* elements is negative or the load factor is nonpositive
1365	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1366	>	* @param s the stream
1367	>	*/
1368	>	private void readObject(java.io.ObjectInputStream s)
1369	>	throws java.io.IOException, ClassNotFoundException {
1370	>	/*
1371	>	* To improve performance in typical cases, we create nodes
1372	>	* while reading, then place in table once size is known.
1373	>	* However, we must also validate uniqueness and deal with
1374	>	* overpopulated bins while doing so, which requires
1375	>	* specialized versions of putVal mechanics.
1376	>	*/
1377	>	sizeCtl = -1; // force exclusion for table construction
1378	>	s.defaultReadObject();
1379	>	long size = 0L;
1380	>	Node<K,V> p = null;
1381	>	for (;;) {
1382	>	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1383	>	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1384	>	if (k != null && v != null) {
1385	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1386	>	++size;
1387	>	}
1388	>	else
1389	>	break;
1390	>	}
1391	>	if (size == 0L)
1392	>	sizeCtl = 0;
1393	>	else {
1394	>	int n;
1395	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1396	>	n = MAXIMUM_CAPACITY;
1397	>	else {
1398	>	int sz = (int)size;
1399	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1400	>	}
1401	>	@SuppressWarnings({"rawtypes","unchecked"})
1402	>	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1403	>	int mask = n - 1;
1404	>	long added = 0L;
1405	>	while (p != null) {
1406	>	boolean insertAtFront;
1407	>	Node<K,V> next = p.next, first;
1408	>	int h = p.hash, j = h & mask;
1409	>	if ((first = tabAt(tab, j)) == null)
1410	>	insertAtFront = true;
1411	>	else {
1412	>	K k = p.key;
1413	>	if (first.hash < 0) {
1414	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1415	>	if (t.putTreeVal(h, k, p.val) == null)
1416	>	++added;
1417	>	insertAtFront = false;
1418	>	}
1419	>	else {
1420	>	int binCount = 0;
1421	>	insertAtFront = true;
1422	>	Node<K,V> q; K qk;
1423	>	for (q = first; q != null; q = q.next) {
1424	>	if (q.hash == h &&
1425	>	((qk = q.key) == k ||
1426	>	(qk != null && k.equals(qk)))) {
1427	>	insertAtFront = false;
1428	>	break;
1429	>	}
1430	>	++binCount;
1431	>	}
1432	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1433	>	insertAtFront = false;
1434	>	++added;
1435	>	p.next = first;
1436	>	TreeNode<K,V> hd = null, tl = null;
1437	>	for (q = p; q != null; q = q.next) {
1438	>	TreeNode<K,V> t = new TreeNode<K,V>
1439	>	(q.hash, q.key, q.val, null, null);
1440	>	if ((t.prev = tl) == null)
1441	>	hd = t;
1442	>	else
1443	>	tl.next = t;
1444	>	tl = t;
1445	>	}
1446	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1447	>	}
1448	>	}
1449	>	}
1450	>	if (insertAtFront) {
1451	>	++added;
1452	>	p.next = first;
1453	>	setTabAt(tab, j, p);
1454	>	}
1455	>	p = next;
1456	>	}
1457	>	table = tab;
1458	>	sizeCtl = n - (n >>> 2);
1459	>	baseCount = added;
1460	>	}
1461	>	}
1462	>
1463	>	// ConcurrentMap methods
1464	>
1465	>	/**
1466	>	* {@inheritDoc}
1467		*
1468	<	* @since 1.6
1468	>	* @return the previous value associated with the specified key,
1469	>	*         or {@code null} if there was no mapping for the key
1470	>	* @throws NullPointerException if the specified key or value is null
1471		*/
1472	<	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
1473	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1472	>	public V putIfAbsent(K key, V value) {
1473	>	return putVal(key, value, true);
1474		}
1475
1476		/**
1477	<	* Creates a new, empty map with the specified initial capacity,
758	<	* and with default load factor (0.75) and concurrencyLevel (16).
1477	>	* {@inheritDoc}
1478		*
1479	<	* @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.
1479	>	* @throws NullPointerException if the specified key is null
1480		*/
1481	<	public ConcurrentHashMap(int initialCapacity) {
1482	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1481	>	public boolean remove(Object key, Object value) {
1482	>	if (key == null)
1483	>	throw new NullPointerException();
1484	>	return value != null && replaceNode(key, null, value) != null;
1485		}
1486
1487		/**
1488	<	* Creates a new, empty map with a default initial capacity (16),
1489	<	* load factor (0.75) and concurrencyLevel (16).
1488	>	* {@inheritDoc}
1489	>	*
1490	>	* @throws NullPointerException if any of the arguments are null
1491		*/
1492	<	public ConcurrentHashMap() {
1493	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1492	>	public boolean replace(K key, V oldValue, V newValue) {
1493	>	if (key == null || oldValue == null || newValue == null)
1494	>	throw new NullPointerException();
1495	>	return replaceNode(key, newValue, oldValue) != null;
1496		}
1497
1498		/**
1499	<	* 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).
1499	>	* {@inheritDoc}
1500		*
1501	<	* @param m the map
1501	>	* @return the previous value associated with the specified key,
1502	>	*         or {@code null} if there was no mapping for the key
1503	>	* @throws NullPointerException if the specified key or value is null
1504		*/
1505	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1506	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1507	<	DEFAULT_INITIAL_CAPACITY),
1508	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
1505	>	public V replace(K key, V value) {
1506	>	if (key == null || value == null)
1507	>	throw new NullPointerException();
1508	>	return replaceNode(key, value, null);
1509		}
1510
1511	+	// Overrides of JDK8+ Map extension method defaults
1512	+
1513		/**
1514	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1514	>	* Returns the value to which the specified key is mapped, or the
1515	>	* given default value if this map contains no mapping for the
1516	>	* key.
1517		*
1518	<	* @return <tt>true</tt> if this map contains no key-value mappings
1518	>	* @param key the key whose associated value is to be returned
1519	>	* @param defaultValue the value to return if this map contains
1520	>	* no mapping for the given key
1521	>	* @return the mapping for the key, if present; else the default value
1522	>	* @throws NullPointerException if the specified key is null
1523		*/
1524	<	public boolean isEmpty() {
1525	<	/*
1526	<	* Sum per-segment modCounts to avoid mis-reporting when
1527	<	* elements are concurrently added and removed in one segment
1528	<	* while checking another, in which case the table was never
1529	<	* actually empty at any point. (The sum ensures accuracy up
1530	<	* through at least 1<<31 per-segment modifications before
1531	<	* recheck.)  Methods size() and containsValue() use similar
1532	<	* constructions for stability checks.
1533	<	*/
1534	<	long sum = 0L;
1535	<	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;
1524	>	public V getOrDefault(Object key, V defaultValue) {
1525	>	V v;
1526	>	return (v = get(key)) == null ? defaultValue : v;
1527	>	}
1528	>
1529	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1530	>	if (action == null) throw new NullPointerException();
1531	>	Node<K,V>[] t;
1532	>	if ((t = table) != null) {
1533	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1534	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1535	>	action.accept(p.key, p.val);
1536		}
1537		}
1538	<	if (sum != 0L) { // recheck unless no modifications
1539	<	for (int j = 0; j < segments.length; ++j) {
1540	<	Segment<K,V> seg = segmentAt(segments, j);
1541	<	if (seg != null) {
1542	<	if (seg.count != 0)
1543	<	return false;
1544	<	sum -= seg.modCount;
1538	>	}
1539	>
1540	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1541	>	if (function == null) throw new NullPointerException();
1542	>	Node<K,V>[] t;
1543	>	if ((t = table) != null) {
1544	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1545	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1546	>	V oldValue = p.val;
1547	>	for (K key = p.key;;) {
1548	>	V newValue = function.apply(key, oldValue);
1549	>	if (newValue == null)
1550	>	throw new NullPointerException();
1551	>	if (replaceNode(key, newValue, oldValue) != null ||
1552	>	(oldValue = get(key)) == null)
1553	>	break;
1554		}
1555		}
826	–	if (sum != 0L)
827	–	return false;
1556		}
829	–	return true;
1557		}
1558
1559		/**
1560	<	* Returns the number of key-value mappings in this map.  If the
1561	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
1562	<	* <tt>Integer.MAX_VALUE</tt>.
1560	>	* If the specified key is not already associated with a value,
1561	>	* attempts to compute its value using the given mapping function
1562	>	* and enters it into this map unless {@code null}.  The entire
1563	>	* method invocation is performed atomically, so the function is
1564	>	* applied at most once per key.  Some attempted update operations
1565	>	* on this map by other threads may be blocked while computation
1566	>	* is in progress, so the computation should be short and simple,
1567	>	* and must not attempt to update any other mappings of this map.
1568		*
1569	<	* @return the number of key-value mappings in this map
1569	>	* @param key key with which the specified value is to be associated
1570	>	* @param mappingFunction the function to compute a value
1571	>	* @return the current (existing or computed) value associated with
1572	>	*         the specified key, or null if the computed value is null
1573	>	* @throws NullPointerException if the specified key or mappingFunction
1574	>	*         is null
1575	>	* @throws IllegalStateException if the computation detectably
1576	>	*         attempts a recursive update to this map that would
1577	>	*         otherwise never complete
1578	>	* @throws RuntimeException or Error if the mappingFunction does so,
1579	>	*         in which case the mapping is left unestablished
1580		*/
1581	<	public int size() {
1582	<	// Try a few times to get accurate count. On failure due to
1583	<	// continuous async changes in table, resort to locking.
1584	<	final Segment<K,V>[] segments = this.segments;
1585	<	int size;
1586	<	boolean overflow; // true if size overflows 32 bits
1587	<	long sum;         // sum of modCounts
1588	<	long last = 0L;   // previous sum
1589	<	int retries = -1; // first iteration isn't retry
1590	<	try {
1591	<	for (;;) {
1592	<	if (retries++ == RETRIES_BEFORE_LOCK) {
1593	<	for (int j = 0; j < segments.length; ++j)
1594	<	ensureSegment(j).lock(); // force creation
1595	<	}
1596	<	sum = 0L;
1597	<	size = 0;
1598	<	overflow = false;
1599	<	for (int j = 0; j < segments.length; ++j) {
1600	<	Segment<K,V> seg = segmentAt(segments, j);
1601	<	if (seg != null) {
1602	<	sum += seg.modCount;
861	<	int c = seg.count;
862	<	if (c < 0 || (size += c) < 0)
863	<	overflow = true;
1581	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1582	>	if (key == null || mappingFunction == null)
1583	>	throw new NullPointerException();
1584	>	int h = spread(key.hashCode());
1585	>	V val = null;
1586	>	int binCount = 0;
1587	>	for (Node<K,V>[] tab = table;;) {
1588	>	Node<K,V> f; int n, i, fh;
1589	>	if (tab == null || (n = tab.length) == 0)
1590	>	tab = initTable();
1591	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1592	>	Node<K,V> r = new ReservationNode<K,V>();
1593	>	synchronized (r) {
1594	>	if (casTabAt(tab, i, null, r)) {
1595	>	binCount = 1;
1596	>	Node<K,V> node = null;
1597	>	try {
1598	>	if ((val = mappingFunction.apply(key)) != null)
1599	>	node = new Node<K,V>(h, key, val, null);
1600	>	} finally {
1601	>	setTabAt(tab, i, node);
1602	>	}
1603		}
1604		}
1605	<	if (sum == last)
1605	>	if (binCount != 0)
1606		break;
868	–	last = sum;
1607		}
1608	<	} finally {
1609	<	if (retries > RETRIES_BEFORE_LOCK) {
1610	<	for (int j = 0; j < segments.length; ++j)
1611	<	segmentAt(segments, j).unlock();
1608	>	else if ((fh = f.hash) == MOVED)
1609	>	tab = helpTransfer(tab, f);
1610	>	else {
1611	>	boolean added = false;
1612	>	synchronized (f) {
1613	>	if (tabAt(tab, i) == f) {
1614	>	if (fh >= 0) {
1615	>	binCount = 1;
1616	>	for (Node<K,V> e = f;; ++binCount) {
1617	>	K ek; V ev;
1618	>	if (e.hash == h &&
1619	>	((ek = e.key) == key ||
1620	>	(ek != null && key.equals(ek)))) {
1621	>	val = e.val;
1622	>	break;
1623	>	}
1624	>	Node<K,V> pred = e;
1625	>	if ((e = e.next) == null) {
1626	>	if ((val = mappingFunction.apply(key)) != null) {
1627	>	added = true;
1628	>	pred.next = new Node<K,V>(h, key, val, null);
1629	>	}
1630	>	break;
1631	>	}
1632	>	}
1633	>	}
1634	>	else if (f instanceof TreeBin) {
1635	>	binCount = 2;
1636	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1637	>	TreeNode<K,V> r, p;
1638	>	if ((r = t.root) != null &&
1639	>	(p = r.findTreeNode(h, key, null)) != null)
1640	>	val = p.val;
1641	>	else if ((val = mappingFunction.apply(key)) != null) {
1642	>	added = true;
1643	>	t.putTreeVal(h, key, val);
1644	>	}
1645	>	}
1646	>	}
1647	>	}
1648	>	if (binCount != 0) {
1649	>	if (binCount >= TREEIFY_THRESHOLD)
1650	>	treeifyBin(tab, i);
1651	>	if (!added)
1652	>	return val;
1653	>	break;
1654	>	}
1655		}
1656		}
1657	<	return overflow ? Integer.MAX_VALUE : size;
1657	>	if (val != null)
1658	>	addCount(1L, binCount);
1659	>	return val;
1660		}
1661
1662		/**
1663	<	* Returns the value to which the specified key is mapped,
1664	<	* or {@code null} if this map contains no mapping for the key.
1663	>	* If the value for the specified key is present, attempts to
1664	>	* compute a new mapping given the key and its current mapped
1665	>	* value.  The entire method invocation is performed atomically.
1666	>	* Some attempted update operations on this map by other threads
1667	>	* may be blocked while computation is in progress, so the
1668	>	* computation should be short and simple, and must not attempt to
1669	>	* update any other mappings of this map.
1670		*
1671	<	* <p>More formally, if this map contains a mapping from a key
1672	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1673	<	* then this method returns {@code v}; otherwise it returns
1674	<	* {@code null}.  (There can be at most one such mapping.)
1675	<	*
1676	<	* @throws NullPointerException if the specified key is null
1671	>	* @param key key with which a value may be associated
1672	>	* @param remappingFunction the function to compute a value
1673	>	* @return the new value associated with the specified key, or null if none
1674	>	* @throws NullPointerException if the specified key or remappingFunction
1675	>	*         is null
1676	>	* @throws IllegalStateException if the computation detectably
1677	>	*         attempts a recursive update to this map that would
1678	>	*         otherwise never complete
1679	>	* @throws RuntimeException or Error if the remappingFunction does so,
1680	>	*         in which case the mapping is unchanged
1681		*/
1682	<	public V get(Object key) {
1683	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1684	<	HashEntry<K,V>[] tab;
1685	<	int h = hash(key.hashCode());
1686	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1687	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1688	<	(tab = s.table) != null) {
1689	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1690	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1691	<	e != null; e = e.next) {
1692	<	K k;
1693	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1694	<	return e.value;
1682	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1683	>	if (key == null || remappingFunction == null)
1684	>	throw new NullPointerException();
1685	>	int h = spread(key.hashCode());
1686	>	V val = null;
1687	>	int delta = 0;
1688	>	int binCount = 0;
1689	>	for (Node<K,V>[] tab = table;;) {
1690	>	Node<K,V> f; int n, i, fh;
1691	>	if (tab == null || (n = tab.length) == 0)
1692	>	tab = initTable();
1693	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1694	>	break;
1695	>	else if ((fh = f.hash) == MOVED)
1696	>	tab = helpTransfer(tab, f);
1697	>	else {
1698	>	synchronized (f) {
1699	>	if (tabAt(tab, i) == f) {
1700	>	if (fh >= 0) {
1701	>	binCount = 1;
1702	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1703	>	K ek;
1704	>	if (e.hash == h &&
1705	>	((ek = e.key) == key ||
1706	>	(ek != null && key.equals(ek)))) {
1707	>	val = remappingFunction.apply(key, e.val);
1708	>	if (val != null)
1709	>	e.val = val;
1710	>	else {
1711	>	delta = -1;
1712	>	Node<K,V> en = e.next;
1713	>	if (pred != null)
1714	>	pred.next = en;
1715	>	else
1716	>	setTabAt(tab, i, en);
1717	>	}
1718	>	break;
1719	>	}
1720	>	pred = e;
1721	>	if ((e = e.next) == null)
1722	>	break;
1723	>	}
1724	>	}
1725	>	else if (f instanceof TreeBin) {
1726	>	binCount = 2;
1727	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1728	>	TreeNode<K,V> r, p;
1729	>	if ((r = t.root) != null &&
1730	>	(p = r.findTreeNode(h, key, null)) != null) {
1731	>	val = remappingFunction.apply(key, p.val);
1732	>	if (val != null)
1733	>	p.val = val;
1734	>	else {
1735	>	delta = -1;
1736	>	if (t.removeTreeNode(p))
1737	>	setTabAt(tab, i, untreeify(t.first));
1738	>	}
1739	>	}
1740	>	}
1741	>	}
1742	>	}
1743	>	if (binCount != 0)
1744	>	break;
1745		}
1746		}
1747	<	return null;
1747	>	if (delta != 0)
1748	>	addCount((long)delta, binCount);
1749	>	return val;
1750		}
1751
1752		/**
1753	<	* Tests if the specified object is a key in this table.
1753	>	* Attempts to compute a mapping for the specified key and its
1754	>	* current mapped value (or {@code null} if there is no current
1755	>	* mapping). The entire method invocation is performed atomically.
1756	>	* Some attempted update operations on this map by other threads
1757	>	* may be blocked while computation is in progress, so the
1758	>	* computation should be short and simple, and must not attempt to
1759	>	* update any other mappings of this Map.
1760		*
1761	<	* @param  key   possible key
1762	<	* @return <tt>true</tt> if and only if the specified object
1763	<	*         is a key in this table, as determined by the
1764	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1765	<	* @throws NullPointerException if the specified key is null
1766	<	*/
1767	<	@SuppressWarnings("unchecked")
1768	<	public boolean containsKey(Object key) {
1769	<	Segment<K,V> s; // same as get() except no need for volatile value read
1770	<	HashEntry<K,V>[] tab;
1771	<	int h = hash(key.hashCode());
1772	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1773	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1774	<	(tab = s.table) != null) {
1775	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1776	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1777	<	e != null; e = e.next) {
1778	<	K k;
1779	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1780	<	return true;
1761	>	* @param key key with which the specified value is to be associated
1762	>	* @param remappingFunction the function to compute a value
1763	>	* @return the new value associated with the specified key, or null if none
1764	>	* @throws NullPointerException if the specified key or remappingFunction
1765	>	*         is null
1766	>	* @throws IllegalStateException if the computation detectably
1767	>	*         attempts a recursive update to this map that would
1768	>	*         otherwise never complete
1769	>	* @throws RuntimeException or Error if the remappingFunction does so,
1770	>	*         in which case the mapping is unchanged
1771	>	*/
1772	>	public V compute(K key,
1773	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1774	>	if (key == null || remappingFunction == null)
1775	>	throw new NullPointerException();
1776	>	int h = spread(key.hashCode());
1777	>	V val = null;
1778	>	int delta = 0;
1779	>	int binCount = 0;
1780	>	for (Node<K,V>[] tab = table;;) {
1781	>	Node<K,V> f; int n, i, fh;
1782	>	if (tab == null || (n = tab.length) == 0)
1783	>	tab = initTable();
1784	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1785	>	Node<K,V> r = new ReservationNode<K,V>();
1786	>	synchronized (r) {
1787	>	if (casTabAt(tab, i, null, r)) {
1788	>	binCount = 1;
1789	>	Node<K,V> node = null;
1790	>	try {
1791	>	if ((val = remappingFunction.apply(key, null)) != null) {
1792	>	delta = 1;
1793	>	node = new Node<K,V>(h, key, val, null);
1794	>	}
1795	>	} finally {
1796	>	setTabAt(tab, i, node);
1797	>	}
1798	>	}
1799	>	}
1800	>	if (binCount != 0)
1801	>	break;
1802	>	}
1803	>	else if ((fh = f.hash) == MOVED)
1804	>	tab = helpTransfer(tab, f);
1805	>	else {
1806	>	synchronized (f) {
1807	>	if (tabAt(tab, i) == f) {
1808	>	if (fh >= 0) {
1809	>	binCount = 1;
1810	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1811	>	K ek;
1812	>	if (e.hash == h &&
1813	>	((ek = e.key) == key ||
1814	>	(ek != null && key.equals(ek)))) {
1815	>	val = remappingFunction.apply(key, e.val);
1816	>	if (val != null)
1817	>	e.val = val;
1818	>	else {
1819	>	delta = -1;
1820	>	Node<K,V> en = e.next;
1821	>	if (pred != null)
1822	>	pred.next = en;
1823	>	else
1824	>	setTabAt(tab, i, en);
1825	>	}
1826	>	break;
1827	>	}
1828	>	pred = e;
1829	>	if ((e = e.next) == null) {
1830	>	val = remappingFunction.apply(key, null);
1831	>	if (val != null) {
1832	>	delta = 1;
1833	>	pred.next =
1834	>	new Node<K,V>(h, key, val, null);
1835	>	}
1836	>	break;
1837	>	}
1838	>	}
1839	>	}
1840	>	else if (f instanceof TreeBin) {
1841	>	binCount = 1;
1842	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1843	>	TreeNode<K,V> r, p;
1844	>	if ((r = t.root) != null)
1845	>	p = r.findTreeNode(h, key, null);
1846	>	else
1847	>	p = null;
1848	>	V pv = (p == null) ? null : p.val;
1849	>	val = remappingFunction.apply(key, pv);
1850	>	if (val != null) {
1851	>	if (p != null)
1852	>	p.val = val;
1853	>	else {
1854	>	delta = 1;
1855	>	t.putTreeVal(h, key, val);
1856	>	}
1857	>	}
1858	>	else if (p != null) {
1859	>	delta = -1;
1860	>	if (t.removeTreeNode(p))
1861	>	setTabAt(tab, i, untreeify(t.first));
1862	>	}
1863	>	}
1864	>	}
1865	>	}
1866	>	if (binCount != 0) {
1867	>	if (binCount >= TREEIFY_THRESHOLD)
1868	>	treeifyBin(tab, i);
1869	>	break;
1870	>	}
1871		}
1872		}
1873	<	return false;
1873	>	if (delta != 0)
1874	>	addCount((long)delta, binCount);
1875	>	return val;
1876		}
1877
1878		/**
1879	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1880	<	* specified value. Note: This method requires a full internal
1881	<	* traversal of the hash table, and so is much slower than
1882	<	* method <tt>containsKey</tt>.
1879	>	* If the specified key is not already associated with a
1880	>	* (non-null) value, associates it with the given value.
1881	>	* Otherwise, replaces the value with the results of the given
1882	>	* remapping function, or removes if {@code null}. The entire
1883	>	* method invocation is performed atomically.  Some attempted
1884	>	* update operations on this map by other threads may be blocked
1885	>	* while computation is in progress, so the computation should be
1886	>	* short and simple, and must not attempt to update any other
1887	>	* mappings of this Map.
1888		*
1889	<	* @param value value whose presence in this map is to be tested
1890	<	* @return <tt>true</tt> if this map maps one or more keys to the
1891	<	*         specified value
1892	<	* @throws NullPointerException if the specified value is null
1889	>	* @param key key with which the specified value is to be associated
1890	>	* @param value the value to use if absent
1891	>	* @param remappingFunction the function to recompute a value if present
1892	>	* @return the new value associated with the specified key, or null if none
1893	>	* @throws NullPointerException if the specified key or the
1894	>	*         remappingFunction is null
1895	>	* @throws RuntimeException or Error if the remappingFunction does so,
1896	>	*         in which case the mapping is unchanged
1897		*/
1898	<	public boolean containsValue(Object value) {
1899	<	// Same idea as size()
949	<	if (value == null)
1898	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1899	>	if (key == null || value == null || remappingFunction == null)
1900		throw new NullPointerException();
1901	<	final Segment<K,V>[] segments = this.segments;
1902	<	boolean found = false;
1903	<	long last = 0L;   // previous sum
1904	<	int retries = -1;
1905	<	try {
1906	<	outer: for (;;) {
1907	<	if (retries++ == RETRIES_BEFORE_LOCK) {
1908	<	for (int j = 0; j < segments.length; ++j)
1909	<	ensureSegment(j).lock(); // force creation
1910	<	}
1911	<	long sum = 0L;
1912	<	for (int j = 0; j < segments.length; ++j) {
1913	<	HashEntry<K,V>[] tab;
1914	<	Segment<K,V> seg = segmentAt(segments, j);
1915	<	if (seg != null && (tab = seg.table) != null) {
1916	<	for (int i = 0 ; i < tab.length; i++) {
1917	<	HashEntry<K,V> e;
1918	<	for (e = entryAt(tab, i); e != null; e = e.next) {
1919	<	V v = e.value;
1920	<	if (v != null && value.equals(v)) {
1921	<	found = true;
1922	<	break outer;
1901	>	int h = spread(key.hashCode());
1902	>	V val = null;
1903	>	int delta = 0;
1904	>	int binCount = 0;
1905	>	for (Node<K,V>[] tab = table;;) {
1906	>	Node<K,V> f; int n, i, fh;
1907	>	if (tab == null || (n = tab.length) == 0)
1908	>	tab = initTable();
1909	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1910	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1911	>	delta = 1;
1912	>	val = value;
1913	>	break;
1914	>	}
1915	>	}
1916	>	else if ((fh = f.hash) == MOVED)
1917	>	tab = helpTransfer(tab, f);
1918	>	else {
1919	>	synchronized (f) {
1920	>	if (tabAt(tab, i) == f) {
1921	>	if (fh >= 0) {
1922	>	binCount = 1;
1923	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1924	>	K ek;
1925	>	if (e.hash == h &&
1926	>	((ek = e.key) == key ||
1927	>	(ek != null && key.equals(ek)))) {
1928	>	val = remappingFunction.apply(e.val, value);
1929	>	if (val != null)
1930	>	e.val = val;
1931	>	else {
1932	>	delta = -1;
1933	>	Node<K,V> en = e.next;
1934	>	if (pred != null)
1935	>	pred.next = en;
1936	>	else
1937	>	setTabAt(tab, i, en);
1938	>	}
1939	>	break;
1940		}
1941	+	pred = e;
1942	+	if ((e = e.next) == null) {
1943	+	delta = 1;
1944	+	val = value;
1945	+	pred.next =
1946	+	new Node<K,V>(h, key, val, null);
1947	+	break;
1948	+	}
1949	+	}
1950	+	}
1951	+	else if (f instanceof TreeBin) {
1952	+	binCount = 2;
1953	+	TreeBin<K,V> t = (TreeBin<K,V>)f;
1954	+	TreeNode<K,V> r = t.root;
1955	+	TreeNode<K,V> p = (r == null) ? null :
1956	+	r.findTreeNode(h, key, null);
1957	+	val = (p == null) ? value :
1958	+	remappingFunction.apply(p.val, value);
1959	+	if (val != null) {
1960	+	if (p != null)
1961	+	p.val = val;
1962	+	else {
1963	+	delta = 1;
1964	+	t.putTreeVal(h, key, val);
1965	+	}
1966	+	}
1967	+	else if (p != null) {
1968	+	delta = -1;
1969	+	if (t.removeTreeNode(p))
1970	+	setTabAt(tab, i, untreeify(t.first));
1971		}
1972		}
976	–	sum += seg.modCount;
1973		}
1974		}
1975	<	if (retries > 0 && sum == last)
1975	>	if (binCount != 0) {
1976	>	if (binCount >= TREEIFY_THRESHOLD)
1977	>	treeifyBin(tab, i);
1978		break;
1979	<	last = sum;
982	<	}
983	<	} finally {
984	<	if (retries > RETRIES_BEFORE_LOCK) {
985	<	for (int j = 0; j < segments.length; ++j)
986	<	segmentAt(segments, j).unlock();
1979	>	}
1980		}
1981		}
1982	<	return found;
1982	>	if (delta != 0)
1983	>	addCount((long)delta, binCount);
1984	>	return val;
1985		}
1986
1987	+	// Hashtable legacy methods
1988	+
1989		/**
1990		* Legacy method testing if some key maps into the specified value
1991		* in this table.  This method is identical in functionality to
1992	<	* {@link #containsValue}, and exists solely to ensure
1992	>	* {@link #containsValue(Object)}, and exists solely to ensure
1993		* full compatibility with class {@link java.util.Hashtable},
1994		* which supported this method prior to introduction of the
1995		* Java Collections framework.
1996		*
1997		* @param  value a value to search for
1998	<	* @return <tt>true</tt> if and only if some key maps to the
1999	<	*         <tt>value</tt> argument in this table as
2000	<	*         determined by the <tt>equals</tt> method;
2001	<	*         <tt>false</tt> otherwise
1998	>	* @return {@code true} if and only if some key maps to the
1999	>	*         {@code value} argument in this table as
2000	>	*         determined by the {@code equals} method;
2001	>	*         {@code false} otherwise
2002		* @throws NullPointerException if the specified value is null
2003		*/
2004	<	public boolean contains(Object value) {
2004	>	@Deprecated public boolean contains(Object value) {
2005		return containsValue(value);
2006		}
2007
2008		/**
2009	<	* Maps the specified key to the specified value in this table.
1013	<	* Neither the key nor the value can be null.
1014	<	*
1015	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1016	<	* with a key that is equal to the original key.
2009	>	* Returns an enumeration of the keys in this table.
2010		*
2011	<	* @param key key with which the specified value is to be associated
2012	<	* @param value value to be associated with the specified key
1020	<	* @return the previous value associated with <tt>key</tt>, or
1021	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1022	<	* @throws NullPointerException if the specified key or value is null
2011	>	* @return an enumeration of the keys in this table
2012	>	* @see #keySet()
2013		*/
2014	<	@SuppressWarnings("unchecked")
2015	<	public V put(K key, V value) {
2016	<	Segment<K,V> s;
2017	<	if (value == null)
1028	<	throw new NullPointerException();
1029	<	int hash = hash(key.hashCode());
1030	<	int j = (hash >>> segmentShift) & segmentMask;
1031	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1032	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1033	<	s = ensureSegment(j);
1034	<	return s.put(key, hash, value, false);
2014	>	public Enumeration<K> keys() {
2015	>	Node<K,V>[] t;
2016	>	int f = (t = table) == null ? 0 : t.length;
2017	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2018		}
2019
2020		/**
2021	<	* {@inheritDoc}
2021	>	* Returns an enumeration of the values in this table.
2022		*
2023	<	* @return the previous value associated with the specified key,
2024	<	*         or <tt>null</tt> if there was no mapping for the key
1042	<	* @throws NullPointerException if the specified key or value is null
2023	>	* @return an enumeration of the values in this table
2024	>	* @see #values()
2025		*/
2026	<	@SuppressWarnings("unchecked")
2027	<	public V putIfAbsent(K key, V value) {
2028	<	Segment<K,V> s;
2029	<	if (value == null)
1048	<	throw new NullPointerException();
1049	<	int hash = hash(key.hashCode());
1050	<	int j = (hash >>> segmentShift) & segmentMask;
1051	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1052	<	(segments, (j << SSHIFT) + SBASE)) == null)
1053	<	s = ensureSegment(j);
1054	<	return s.put(key, hash, value, true);
2026	>	public Enumeration<V> elements() {
2027	>	Node<K,V>[] t;
2028	>	int f = (t = table) == null ? 0 : t.length;
2029	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2030		}
2031
2032	+	// ConcurrentHashMap-only methods
2033	+
2034		/**
2035	<	* Copies all of the mappings from the specified map to this one.
2036	<	* These mappings replace any mappings that this map had for any of the
2037	<	* keys currently in the specified map.
2035	>	* Returns the number of mappings. This method should be used
2036	>	* instead of {@link #size} because a ConcurrentHashMap may
2037	>	* contain more mappings than can be represented as an int. The
2038	>	* value returned is an estimate; the actual count may differ if
2039	>	* there are concurrent insertions or removals.
2040		*
2041	<	* @param m mappings to be stored in this map
2041	>	* @return the number of mappings
2042	>	* @since 1.8
2043		*/
2044	<	public void putAll(Map<? extends K, ? extends V> m) {
2045	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2046	<	put(e.getKey(), e.getValue());
2044	>	public long mappingCount() {
2045	>	long n = sumCount();
2046	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2047		}
2048
2049		/**
2050	<	* Removes the key (and its corresponding value) from this map.
2051	<	* This method does nothing if the key is not in the map.
2050	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2051	>	* from the given type to {@code Boolean.TRUE}.
2052		*
2053	<	* @param  key the key that needs to be removed
2054	<	* @return the previous value associated with <tt>key</tt>, or
1075	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1076	<	* @throws NullPointerException if the specified key is null
2053	>	* @return the new set
2054	>	* @since 1.8
2055		*/
2056	<	public V remove(Object key) {
2057	<	int hash = hash(key.hashCode());
2058	<	Segment<K,V> s = segmentForHash(hash);
1081	<	return s == null ? null : s.remove(key, hash, null);
2056	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2057	>	return new KeySetView<K,Boolean>
2058	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2059		}
2060
2061		/**
2062	<	* {@inheritDoc}
2062	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2063	>	* from the given type to {@code Boolean.TRUE}.
2064		*
2065	<	* @throws NullPointerException if the specified key is null
2065	>	* @param initialCapacity The implementation performs internal
2066	>	* sizing to accommodate this many elements.
2067	>	* @throws IllegalArgumentException if the initial capacity of
2068	>	* elements is negative
2069	>	* @return the new set
2070	>	* @since 1.8
2071		*/
2072	<	public boolean remove(Object key, Object value) {
2073	<	int hash = hash(key.hashCode());
2074	<	Segment<K,V> s;
1092	<	return value != null && (s = segmentForHash(hash)) != null &&
1093	<	s.remove(key, hash, value) != null;
2072	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2073	>	return new KeySetView<K,Boolean>
2074	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2075		}
2076
2077		/**
2078	<	* {@inheritDoc}
2078	>	* Returns a {@link Set} view of the keys in this map, using the
2079	>	* given common mapped value for any additions (i.e., {@link
2080	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2081	>	* This is of course only appropriate if it is acceptable to use
2082	>	* the same value for all additions from this view.
2083		*
2084	<	* @throws NullPointerException if any of the arguments are null
2084	>	* @param mappedValue the mapped value to use for any additions
2085	>	* @return the set view
2086	>	* @throws NullPointerException if the mappedValue is null
2087		*/
2088	<	public boolean replace(K key, V oldValue, V newValue) {
2089	<	int hash = hash(key.hashCode());
1103	<	if (oldValue == null || newValue == null)
2088	>	public KeySetView<K,V> keySet(V mappedValue) {
2089	>	if (mappedValue == null)
2090		throw new NullPointerException();
2091	<	Segment<K,V> s = segmentForHash(hash);
1106	<	return s != null && s.replace(key, hash, oldValue, newValue);
2091	>	return new KeySetView<K,V>(this, mappedValue);
2092		}
2093
2094	+	/* ---------------- Special Nodes -------------- */
2095	+
2096		/**
2097	<	* {@inheritDoc}
1111	<	*
1112	<	* @return the previous value associated with the specified key,
1113	<	*         or <tt>null</tt> if there was no mapping for the key
1114	<	* @throws NullPointerException if the specified key or value is null
2097	>	* A node inserted at head of bins during transfer operations.
2098		*/
2099	<	public V replace(K key, V value) {
2100	<	int hash = hash(key.hashCode());
2101	<	if (value == null)
2102	<	throw new NullPointerException();
2103	<	Segment<K,V> s = segmentForHash(hash);
2104	<	return s == null ? null : s.replace(key, hash, value);
2099	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2100	>	final Node<K,V>[] nextTable;
2101	>	ForwardingNode(Node<K,V>[] tab) {
2102	>	super(MOVED, null, null, null);
2103	>	this.nextTable = tab;
2104	>	}
2105	>
2106	>	Node<K,V> find(int h, Object k) {
2107	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2108	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2109	>	Node<K,V> e; int n;
2110	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2111	>	(e = tabAt(tab, (n - 1) & h)) == null)
2112	>	return null;
2113	>	for (;;) {
2114	>	int eh; K ek;
2115	>	if ((eh = e.hash) == h &&
2116	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2117	>	return e;
2118	>	if (eh < 0) {
2119	>	if (e instanceof ForwardingNode) {
2120	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2121	>	continue outer;
2122	>	}
2123	>	else
2124	>	return e.find(h, k);
2125	>	}
2126	>	if ((e = e.next) == null)
2127	>	return null;
2128	>	}
2129	>	}
2130	>	}
2131		}
2132
2133		/**
2134	<	* Removes all of the mappings from this map.
2134	>	* A place-holder node used in computeIfAbsent and compute
2135		*/
2136	<	public void clear() {
2137	<	final Segment<K,V>[] segments = this.segments;
2138	<	for (int j = 0; j < segments.length; ++j) {
2139	<	Segment<K,V> s = segmentAt(segments, j);
2140	<	if (s != null)
2141	<	s.clear();
2136	>	static final class ReservationNode<K,V> extends Node<K,V> {
2137	>	ReservationNode() {
2138	>	super(RESERVED, null, null, null);
2139	>	}
2140	>
2141	>	Node<K,V> find(int h, Object k) {
2142	>	return null;
2143		}
2144		}
2145
2146	+	/* ---------------- Table Initialization and Resizing -------------- */
2147	+
2148		/**
2149	<	* Returns a {@link Set} view of the keys contained in this map.
1138	<	* The set is backed by the map, so changes to the map are
1139	<	* reflected in the set, and vice-versa.  The set supports element
1140	<	* removal, which removes the corresponding mapping from this map,
1141	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1142	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1143	<	* operations.  It does not support the <tt>add</tt> or
1144	<	* <tt>addAll</tt> operations.
1145	<	*
1146	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1147	<	* that will never throw {@link ConcurrentModificationException},
1148	<	* and guarantees to traverse elements as they existed upon
1149	<	* construction of the iterator, and may (but is not guaranteed to)
1150	<	* reflect any modifications subsequent to construction.
2149	>	* Initializes table, using the size recorded in sizeCtl.
2150		*/
2151	<	public Set<K> keySet() {
2152	<	Set<K> ks = keySet;
2153	<	return (ks != null) ? ks : (keySet = new KeySet());
2151	>	private final Node<K,V>[] initTable() {
2152	>	Node<K,V>[] tab; int sc;
2153	>	while ((tab = table) == null || tab.length == 0) {
2154	>	if ((sc = sizeCtl) < 0)
2155	>	Thread.yield(); // lost initialization race; just spin
2156	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2157	>	try {
2158	>	if ((tab = table) == null || tab.length == 0) {
2159	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2160	>	@SuppressWarnings({"rawtypes","unchecked"})
2161	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2162	>	table = tab = nt;
2163	>	sc = n - (n >>> 2);
2164	>	}
2165	>	} finally {
2166	>	sizeCtl = sc;
2167	>	}
2168	>	break;
2169	>	}
2170	>	}
2171	>	return tab;
2172		}
2173
2174		/**
2175	<	* Returns a {@link Collection} view of the values contained in this map.
2176	<	* The collection is backed by the map, so changes to the map are
2177	<	* reflected in the collection, and vice-versa.  The collection
2178	<	* supports element removal, which removes the corresponding
2179	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1163	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1164	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1165	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
2175	>	* Adds to count, and if table is too small and not already
2176	>	* resizing, initiates transfer. If already resizing, helps
2177	>	* perform transfer if work is available.  Rechecks occupancy
2178	>	* after a transfer to see if another resize is already needed
2179	>	* because resizings are lagging additions.
2180		*
2181	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
2182	<	* 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.
2181	>	* @param x the count to add
2182	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2183		*/
2184	<	public Collection<V> values() {
2185	<	Collection<V> vs = values;
2186	<	return (vs != null) ? vs : (values = new Values());
2184	>	private final void addCount(long x, int check) {
2185	>	CounterCell[] as; long b, s;
2186	>	if ((as = counterCells) != null ||
2187	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2188	>	CounterCell a; long v; int m;
2189	>	boolean uncontended = true;
2190	>	if (as == null || (m = as.length - 1) < 0 ||
2191	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2192	>	!(uncontended =
2193	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2194	>	fullAddCount(x, uncontended);
2195	>	return;
2196	>	}
2197	>	if (check <= 1)
2198	>	return;
2199	>	s = sumCount();
2200	>	}
2201	>	if (check >= 0) {
2202	>	Node<K,V>[] tab, nt; int sc;
2203	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2204	>	tab.length < MAXIMUM_CAPACITY) {
2205	>	if (sc < 0) {
2206	>	if (sc == -1 || transferIndex <= transferOrigin ||
2207	>	(nt = nextTable) == null)
2208	>	break;
2209	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2210	>	transfer(tab, nt);
2211	>	}
2212	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2213	>	transfer(tab, null);
2214	>	s = sumCount();
2215	>	}
2216	>	}
2217		}
2218
2219		/**
2220	<	* Returns a {@link Set} view of the mappings contained in this map.
1180	<	* The set is backed by the map, so changes to the map are
1181	<	* reflected in the set, and vice-versa.  The set supports element
1182	<	* removal, which removes the corresponding mapping from the map,
1183	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1184	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1185	<	* operations.  It does not support the <tt>add</tt> or
1186	<	* <tt>addAll</tt> operations.
1187	<	*
1188	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1189	<	* that will never throw {@link ConcurrentModificationException},
1190	<	* and guarantees to traverse elements as they existed upon
1191	<	* construction of the iterator, and may (but is not guaranteed to)
1192	<	* reflect any modifications subsequent to construction.
2220	>	* Helps transfer if a resize is in progress.
2221		*/
2222	<	public Set<Map.Entry<K,V>> entrySet() {
2223	<	Set<Map.Entry<K,V>> es = entrySet;
2224	<	return (es != null) ? es : (entrySet = new EntrySet());
2222	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2223	>	Node<K,V>[] nextTab; int sc;
2224	>	if ((f instanceof ForwardingNode) &&
2225	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2226	>	if (nextTab == nextTable && tab == table &&
2227	>	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2228	>	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2229	>	transfer(tab, nextTab);
2230	>	return nextTab;
2231	>	}
2232	>	return table;
2233		}
2234
2235		/**
2236	<	* Returns an enumeration of the keys in this table.
2236	>	* Tries to presize table to accommodate the given number of elements.
2237		*
2238	<	* @return an enumeration of the keys in this table
1203	<	* @see #keySet()
2238	>	* @param size number of elements (doesn't need to be perfectly accurate)
2239		*/
2240	<	public Enumeration<K> keys() {
2241	<	return new KeyIterator();
2240	>	private final void tryPresize(int size) {
2241	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2242	>	tableSizeFor(size + (size >>> 1) + 1);
2243	>	int sc;
2244	>	while ((sc = sizeCtl) >= 0) {
2245	>	Node<K,V>[] tab = table; int n;
2246	>	if (tab == null || (n = tab.length) == 0) {
2247	>	n = (sc > c) ? sc : c;
2248	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2249	>	try {
2250	>	if (table == tab) {
2251	>	@SuppressWarnings({"rawtypes","unchecked"})
2252	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2253	>	table = nt;
2254	>	sc = n - (n >>> 2);
2255	>	}
2256	>	} finally {
2257	>	sizeCtl = sc;
2258	>	}
2259	>	}
2260	>	}
2261	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2262	>	break;
2263	>	else if (tab == table &&
2264	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2265	>	transfer(tab, null);
2266	>	}
2267		}
2268
2269		/**
2270	<	* Returns an enumeration of the values in this table.
2271	<	*
1212	<	* @return an enumeration of the values in this table
1213	<	* @see #values()
2270	>	* Moves and/or copies the nodes in each bin to new table. See
2271	>	* above for explanation.
2272		*/
2273	<	public Enumeration<V> elements() {
2274	<	return new ValueIterator();
2273	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2274	>	int n = tab.length, stride;
2275	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2276	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2277	>	if (nextTab == null) {            // initiating
2278	>	try {
2279	>	@SuppressWarnings({"rawtypes","unchecked"})
2280	>	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2281	>	nextTab = nt;
2282	>	} catch (Throwable ex) {      // try to cope with OOME
2283	>	sizeCtl = Integer.MAX_VALUE;
2284	>	return;
2285	>	}
2286	>	nextTable = nextTab;
2287	>	transferOrigin = n;
2288	>	transferIndex = n;
2289	>	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2290	>	for (int k = n; k > 0;) {    // progressively reveal ready slots
2291	>	int nextk = (k > stride) ? k - stride : 0;
2292	>	for (int m = nextk; m < k; ++m)
2293	>	nextTab[m] = rev;
2294	>	for (int m = n + nextk; m < n + k; ++m)
2295	>	nextTab[m] = rev;
2296	>	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2297	>	}
2298	>	}
2299	>	int nextn = nextTab.length;
2300	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2301	>	boolean advance = true;
2302	>	boolean finishing = false; // to ensure sweep before committing nextTab
2303	>	for (int i = 0, bound = 0;;) {
2304	>	int nextIndex, nextBound, fh; Node<K,V> f;
2305	>	while (advance) {
2306	>	if (--i >= bound || finishing)
2307	>	advance = false;
2308	>	else if ((nextIndex = transferIndex) <= transferOrigin) {
2309	>	i = -1;
2310	>	advance = false;
2311	>	}
2312	>	else if (U.compareAndSwapInt
2313	>	(this, TRANSFERINDEX, nextIndex,
2314	>	nextBound = (nextIndex > stride ?
2315	>	nextIndex - stride : 0))) {
2316	>	bound = nextBound;
2317	>	i = nextIndex - 1;
2318	>	advance = false;
2319	>	}
2320	>	}
2321	>	if (i < 0 || i >= n || i + n >= nextn) {
2322	>	if (finishing) {
2323	>	nextTable = null;
2324	>	table = nextTab;
2325	>	sizeCtl = (n << 1) - (n >>> 1);
2326	>	return;
2327	>	}
2328	>	for (int sc;;) {
2329	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2330	>	if (sc != -1)
2331	>	return;
2332	>	finishing = advance = true;
2333	>	i = n; // recheck before commit
2334	>	break;
2335	>	}
2336	>	}
2337	>	}
2338	>	else if ((f = tabAt(tab, i)) == null) {
2339	>	if (casTabAt(tab, i, null, fwd)) {
2340	>	setTabAt(nextTab, i, null);
2341	>	setTabAt(nextTab, i + n, null);
2342	>	advance = true;
2343	>	}
2344	>	}
2345	>	else if ((fh = f.hash) == MOVED)
2346	>	advance = true; // already processed
2347	>	else {
2348	>	synchronized (f) {
2349	>	if (tabAt(tab, i) == f) {
2350	>	Node<K,V> ln, hn;
2351	>	if (fh >= 0) {
2352	>	int runBit = fh & n;
2353	>	Node<K,V> lastRun = f;
2354	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2355	>	int b = p.hash & n;
2356	>	if (b != runBit) {
2357	>	runBit = b;
2358	>	lastRun = p;
2359	>	}
2360	>	}
2361	>	if (runBit == 0) {
2362	>	ln = lastRun;
2363	>	hn = null;
2364	>	}
2365	>	else {
2366	>	hn = lastRun;
2367	>	ln = null;
2368	>	}
2369	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2370	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2371	>	if ((ph & n) == 0)
2372	>	ln = new Node<K,V>(ph, pk, pv, ln);
2373	>	else
2374	>	hn = new Node<K,V>(ph, pk, pv, hn);
2375	>	}
2376	>	setTabAt(nextTab, i, ln);
2377	>	setTabAt(nextTab, i + n, hn);
2378	>	setTabAt(tab, i, fwd);
2379	>	advance = true;
2380	>	}
2381	>	else if (f instanceof TreeBin) {
2382	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2383	>	TreeNode<K,V> lo = null, loTail = null;
2384	>	TreeNode<K,V> hi = null, hiTail = null;
2385	>	int lc = 0, hc = 0;
2386	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2387	>	int h = e.hash;
2388	>	TreeNode<K,V> p = new TreeNode<K,V>
2389	>	(h, e.key, e.val, null, null);
2390	>	if ((h & n) == 0) {
2391	>	if ((p.prev = loTail) == null)
2392	>	lo = p;
2393	>	else
2394	>	loTail.next = p;
2395	>	loTail = p;
2396	>	++lc;
2397	>	}
2398	>	else {
2399	>	if ((p.prev = hiTail) == null)
2400	>	hi = p;
2401	>	else
2402	>	hiTail.next = p;
2403	>	hiTail = p;
2404	>	++hc;
2405	>	}
2406	>	}
2407	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2408	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2409	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2410	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2411	>	setTabAt(nextTab, i, ln);
2412	>	setTabAt(nextTab, i + n, hn);
2413	>	setTabAt(tab, i, fwd);
2414	>	advance = true;
2415	>	}
2416	>	}
2417	>	}
2418	>	}
2419	>	}
2420		}
2421
2422	<	/* ---------------- Iterator Support -------------- */
2422	>	/* ---------------- Counter support -------------- */
2423
2424	<	abstract class HashIterator {
2425	<	int nextSegmentIndex;
2426	<	int nextTableIndex;
2427	<	HashEntry<K,V>[] currentTable;
2428	<	HashEntry<K, V> nextEntry;
2429	<	HashEntry<K, V> lastReturned;
2424	>	/**
2425	>	* A padded cell for distributing counts.  Adapted from LongAdder
2426	>	* and Striped64.  See their internal docs for explanation.
2427	>	*/
2428	>	@sun.misc.Contended static final class CounterCell {
2429	>	volatile long value;
2430	>	CounterCell(long x) { value = x; }
2431	>	}
2432
2433	<	HashIterator() {
2434	<	nextSegmentIndex = segments.length - 1;
2435	<	nextTableIndex = -1;
2436	<	advance();
2433	>	final long sumCount() {
2434	>	CounterCell[] as = counterCells; CounterCell a;
2435	>	long sum = baseCount;
2436	>	if (as != null) {
2437	>	for (int i = 0; i < as.length; ++i) {
2438	>	if ((a = as[i]) != null)
2439	>	sum += a.value;
2440	>	}
2441	>	}
2442	>	return sum;
2443	>	}
2444	>
2445	>	// See LongAdder version for explanation
2446	>	private final void fullAddCount(long x, boolean wasUncontended) {
2447	>	int h;
2448	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2449	>	ThreadLocalRandom.localInit();      // force initialization
2450	>	h = ThreadLocalRandom.getProbe();
2451	>	wasUncontended = true;
2452	>	}
2453	>	boolean collide = false;                // True if last slot nonempty
2454	>	for (;;) {
2455	>	CounterCell[] as; CounterCell a; int n; long v;
2456	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2457	>	if ((a = as[(n - 1) & h]) == null) {
2458	>	if (cellsBusy == 0) {            // Try to attach new Cell
2459	>	CounterCell r = new CounterCell(x); // Optimistic create
2460	>	if (cellsBusy == 0 &&
2461	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2462	>	boolean created = false;
2463	>	try {               // Recheck under lock
2464	>	CounterCell[] rs; int m, j;
2465	>	if ((rs = counterCells) != null &&
2466	>	(m = rs.length) > 0 &&
2467	>	rs[j = (m - 1) & h] == null) {
2468	>	rs[j] = r;
2469	>	created = true;
2470	>	}
2471	>	} finally {
2472	>	cellsBusy = 0;
2473	>	}
2474	>	if (created)
2475	>	break;
2476	>	continue;           // Slot is now non-empty
2477	>	}
2478	>	}
2479	>	collide = false;
2480	>	}
2481	>	else if (!wasUncontended)       // CAS already known to fail
2482	>	wasUncontended = true;      // Continue after rehash
2483	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2484	>	break;
2485	>	else if (counterCells != as || n >= NCPU)
2486	>	collide = false;            // At max size or stale
2487	>	else if (!collide)
2488	>	collide = true;
2489	>	else if (cellsBusy == 0 &&
2490	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2491	>	try {
2492	>	if (counterCells == as) {// Expand table unless stale
2493	>	CounterCell[] rs = new CounterCell[n << 1];
2494	>	for (int i = 0; i < n; ++i)
2495	>	rs[i] = as[i];
2496	>	counterCells = rs;
2497	>	}
2498	>	} finally {
2499	>	cellsBusy = 0;
2500	>	}
2501	>	collide = false;
2502	>	continue;                   // Retry with expanded table
2503	>	}
2504	>	h = ThreadLocalRandom.advanceProbe(h);
2505	>	}
2506	>	else if (cellsBusy == 0 && counterCells == as &&
2507	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2508	>	boolean init = false;
2509	>	try {                           // Initialize table
2510	>	if (counterCells == as) {
2511	>	CounterCell[] rs = new CounterCell[2];
2512	>	rs[h & 1] = new CounterCell(x);
2513	>	counterCells = rs;
2514	>	init = true;
2515	>	}
2516	>	} finally {
2517	>	cellsBusy = 0;
2518	>	}
2519	>	if (init)
2520	>	break;
2521	>	}
2522	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2523	>	break;                          // Fall back on using base
2524	>	}
2525	>	}
2526	>
2527	>	/* ---------------- Conversion from/to TreeBins -------------- */
2528	>
2529	>	/**
2530	>	* Replaces all linked nodes in bin at given index unless table is
2531	>	* too small, in which case resizes instead.
2532	>	*/
2533	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2534	>	Node<K,V> b; int n, sc;
2535	>	if (tab != null) {
2536	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY) {
2537	>	if (tab == table && (sc = sizeCtl) >= 0 &&
2538	>	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2539	>	transfer(tab, null);
2540	>	}
2541	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2542	>	synchronized (b) {
2543	>	if (tabAt(tab, index) == b) {
2544	>	TreeNode<K,V> hd = null, tl = null;
2545	>	for (Node<K,V> e = b; e != null; e = e.next) {
2546	>	TreeNode<K,V> p =
2547	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2548	>	null, null);
2549	>	if ((p.prev = tl) == null)
2550	>	hd = p;
2551	>	else
2552	>	tl.next = p;
2553	>	tl = p;
2554	>	}
2555	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2556	>	}
2557	>	}
2558	>	}
2559	>	}
2560	>	}
2561	>
2562	>	/**
2563	>	* Returns a list on non-TreeNodes replacing those in given list.
2564	>	*/
2565	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2566	>	Node<K,V> hd = null, tl = null;
2567	>	for (Node<K,V> q = b; q != null; q = q.next) {
2568	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2569	>	if (tl == null)
2570	>	hd = p;
2571	>	else
2572	>	tl.next = p;
2573	>	tl = p;
2574	>	}
2575	>	return hd;
2576	>	}
2577	>
2578	>	/* ---------------- TreeNodes -------------- */
2579	>
2580	>	/**
2581	>	* Nodes for use in TreeBins
2582	>	*/
2583	>	static final class TreeNode<K,V> extends Node<K,V> {
2584	>	TreeNode<K,V> parent;  // red-black tree links
2585	>	TreeNode<K,V> left;
2586	>	TreeNode<K,V> right;
2587	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2588	>	boolean red;
2589	>
2590	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2591	>	TreeNode<K,V> parent) {
2592	>	super(hash, key, val, next);
2593	>	this.parent = parent;
2594	>	}
2595	>
2596	>	Node<K,V> find(int h, Object k) {
2597	>	return findTreeNode(h, k, null);
2598		}
2599
2600		/**
2601	<	* Sets nextEntry to first node of next non-empty table
2602	<	* (in backwards order, to simplify checks).
2601	>	* Returns the TreeNode (or null if not found) for the given key
2602	>	* starting at given root.
2603		*/
2604	<	final void advance() {
2605	<	for (;;) {
2606	<	if (nextTableIndex >= 0) {
2607	<	if ((nextEntry = entryAt(currentTable,
2608	<	nextTableIndex--)) != null)
2604	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2605	>	if (k != null) {
2606	>	TreeNode<K,V> p = this;
2607	>	do  {
2608	>	int ph, dir; K pk; TreeNode<K,V> q;
2609	>	TreeNode<K,V> pl = p.left, pr = p.right;
2610	>	if ((ph = p.hash) > h)
2611	>	p = pl;
2612	>	else if (ph < h)
2613	>	p = pr;
2614	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2615	>	return p;
2616	>	else if (pl == null && pr == null)
2617		break;
2618	+	else if ((kc != null ||
2619	+	(kc = comparableClassFor(k)) != null) &&
2620	+	(dir = compareComparables(kc, k, pk)) != 0)
2621	+	p = (dir < 0) ? pl : pr;
2622	+	else if (pl == null)
2623	+	p = pr;
2624	+	else if (pr == null ||
2625	+	(q = pr.findTreeNode(h, k, kc)) == null)
2626	+	p = pl;
2627	+	else
2628	+	return q;
2629	+	} while (p != null);
2630	+	}
2631	+	return null;
2632	+	}
2633	+	}
2634	+
2635	+	/* ---------------- TreeBins -------------- */
2636	+
2637	+	/**
2638	+	* TreeNodes used at the heads of bins. TreeBins do not hold user
2639	+	* keys or values, but instead point to list of TreeNodes and
2640	+	* their root. They also maintain a parasitic read-write lock
2641	+	* forcing writers (who hold bin lock) to wait for readers (who do
2642	+	* not) to complete before tree restructuring operations.
2643	+	*/
2644	+	static final class TreeBin<K,V> extends Node<K,V> {
2645	+	TreeNode<K,V> root;
2646	+	volatile TreeNode<K,V> first;
2647	+	volatile Thread waiter;
2648	+	volatile int lockState;
2649	+	// values for lockState
2650	+	static final int WRITER = 1; // set while holding write lock
2651	+	static final int WAITER = 2; // set when waiting for write lock
2652	+	static final int READER = 4; // increment value for setting read lock
2653	+
2654	+	/**
2655	+	* Creates bin with initial set of nodes headed by b.
2656	+	*/
2657	+	TreeBin(TreeNode<K,V> b) {
2658	+	super(TREEBIN, null, null, null);
2659	+	this.first = b;
2660	+	TreeNode<K,V> r = null;
2661	+	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2662	+	next = (TreeNode<K,V>)x.next;
2663	+	x.left = x.right = null;
2664	+	if (r == null) {
2665	+	x.parent = null;
2666	+	x.red = false;
2667	+	r = x;
2668		}
2669	<	else if (nextSegmentIndex >= 0) {
2670	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2671	<	if (seg != null && (currentTable = seg.table) != null)
2672	<	nextTableIndex = currentTable.length - 1;
2669	>	else {
2670	>	Object key = x.key;
2671	>	int hash = x.hash;
2672	>	Class<?> kc = null;
2673	>	for (TreeNode<K,V> p = r;;) {
2674	>	int dir, ph;
2675	>	if ((ph = p.hash) > hash)
2676	>	dir = -1;
2677	>	else if (ph < hash)
2678	>	dir = 1;
2679	>	else if ((kc != null ||
2680	>	(kc = comparableClassFor(key)) != null))
2681	>	dir = compareComparables(kc, key, p.key);
2682	>	else
2683	>	dir = 0;
2684	>	TreeNode<K,V> xp = p;
2685	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2686	>	x.parent = xp;
2687	>	if (dir <= 0)
2688	>	xp.left = x;
2689	>	else
2690	>	xp.right = x;
2691	>	r = balanceInsertion(r, x);
2692	>	break;
2693	>	}
2694	>	}
2695		}
2696	<	else
2696	>	}
2697	>	this.root = r;
2698	>	}
2699	>
2700	>	/**
2701	>	* Acquires write lock for tree restructuring.
2702	>	*/
2703	>	private final void lockRoot() {
2704	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2705	>	contendedLock(); // offload to separate method
2706	>	}
2707	>
2708	>	/**
2709	>	* Releases write lock for tree restructuring.
2710	>	*/
2711	>	private final void unlockRoot() {
2712	>	lockState = 0;
2713	>	}
2714	>
2715	>	/**
2716	>	* Possibly blocks awaiting root lock.
2717	>	*/
2718	>	private final void contendedLock() {
2719	>	boolean waiting = false;
2720	>	for (int s;;) {
2721	>	if (((s = lockState) & WRITER) == 0) {
2722	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2723	>	if (waiting)
2724	>	waiter = null;
2725	>	return;
2726	>	}
2727	>	}
2728	>	else if ((s | WAITER) == 0) {
2729	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2730	>	waiting = true;
2731	>	waiter = Thread.currentThread();
2732	>	}
2733	>	}
2734	>	else if (waiting)
2735	>	LockSupport.park(this);
2736	>	}
2737	>	}
2738	>
2739	>	/**
2740	>	* Returns matching node or null if none. Tries to search
2741	>	* using tree comparisons from root, but continues linear
2742	>	* search when lock not available.
2743	>	*/
2744	>	final Node<K,V> find(int h, Object k) {
2745	>	if (k != null) {
2746	>	for (Node<K,V> e = first; e != null; e = e.next) {
2747	>	int s; K ek;
2748	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2749	>	if (e.hash == h &&
2750	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2751	>	return e;
2752	>	}
2753	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2754	>	s + READER)) {
2755	>	TreeNode<K,V> r, p;
2756	>	try {
2757	>	p = ((r = root) == null ? null :
2758	>	r.findTreeNode(h, k, null));
2759	>	} finally {
2760	>	Thread w;
2761	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2762	>	(READER|WAITER) && (w = waiter) != null)
2763	>	LockSupport.unpark(w);
2764	>	}
2765	>	return p;
2766	>	}
2767	>	}
2768	>	}
2769	>	return null;
2770	>	}
2771	>
2772	>	/**
2773	>	* Finds or adds a node.
2774	>	* @return null if added
2775	>	*/
2776	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2777	>	Class<?> kc = null;
2778	>	for (TreeNode<K,V> p = root;;) {
2779	>	int dir, ph; K pk; TreeNode<K,V> q, pr;
2780	>	if (p == null) {
2781	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2782		break;
2783	+	}
2784	+	else if ((ph = p.hash) > h)
2785	+	dir = -1;
2786	+	else if (ph < h)
2787	+	dir = 1;
2788	+	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2789	+	return p;
2790	+	else if ((kc == null &&
2791	+	(kc = comparableClassFor(k)) == null) ||
2792	+	(dir = compareComparables(kc, k, pk)) == 0) {
2793	+	if (p.left == null)
2794	+	dir = 1;
2795	+	else if ((pr = p.right) == null ||
2796	+	(q = pr.findTreeNode(h, k, kc)) == null)
2797	+	dir = -1;
2798	+	else
2799	+	return q;
2800	+	}
2801	+	TreeNode<K,V> xp = p;
2802	+	if ((p = (dir < 0) ? p.left : p.right) == null) {
2803	+	TreeNode<K,V> x, f = first;
2804	+	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2805	+	if (f != null)
2806	+	f.prev = x;
2807	+	if (dir < 0)
2808	+	xp.left = x;
2809	+	else
2810	+	xp.right = x;
2811	+	if (!xp.red)
2812	+	x.red = true;
2813	+	else {
2814	+	lockRoot();
2815	+	try {
2816	+	root = balanceInsertion(root, x);
2817	+	} finally {
2818	+	unlockRoot();
2819	+	}
2820	+	}
2821	+	break;
2822	+	}
2823		}
2824	+	assert checkInvariants(root);
2825	+	return null;
2826		}
2827
2828	<	final HashEntry<K,V> nextEntry() {
2829	<	HashEntry<K,V> e = nextEntry;
2830	<	if (e == null)
2831	<	throw new NoSuchElementException();
2832	<	lastReturned = e; // cannot assign until after null check
2833	<	if ((nextEntry = e.next) == null)
2834	<	advance();
2835	<	return e;
2828	>	/**
2829	>	* Removes the given node, that must be present before this
2830	>	* call.  This is messier than typical red-black deletion code
2831	>	* because we cannot swap the contents of an interior node
2832	>	* with a leaf successor that is pinned by "next" pointers
2833	>	* that are accessible independently of lock. So instead we
2834	>	* swap the tree linkages.
2835	>	*
2836	>	* @return true if now too small, so should be untreeified
2837	>	*/
2838	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2839	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2840	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2841	>	TreeNode<K,V> r, rl;
2842	>	if (pred == null)
2843	>	first = next;
2844	>	else
2845	>	pred.next = next;
2846	>	if (next != null)
2847	>	next.prev = pred;
2848	>	if (first == null) {
2849	>	root = null;
2850	>	return true;
2851	>	}
2852	>	if ((r = root) == null || r.right == null || // too small
2853	>	(rl = r.left) == null || rl.left == null)
2854	>	return true;
2855	>	lockRoot();
2856	>	try {
2857	>	TreeNode<K,V> replacement;
2858	>	TreeNode<K,V> pl = p.left;
2859	>	TreeNode<K,V> pr = p.right;
2860	>	if (pl != null && pr != null) {
2861	>	TreeNode<K,V> s = pr, sl;
2862	>	while ((sl = s.left) != null) // find successor
2863	>	s = sl;
2864	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2865	>	TreeNode<K,V> sr = s.right;
2866	>	TreeNode<K,V> pp = p.parent;
2867	>	if (s == pr) { // p was s's direct parent
2868	>	p.parent = s;
2869	>	s.right = p;
2870	>	}
2871	>	else {
2872	>	TreeNode<K,V> sp = s.parent;
2873	>	if ((p.parent = sp) != null) {
2874	>	if (s == sp.left)
2875	>	sp.left = p;
2876	>	else
2877	>	sp.right = p;
2878	>	}
2879	>	if ((s.right = pr) != null)
2880	>	pr.parent = s;
2881	>	}
2882	>	p.left = null;
2883	>	if ((p.right = sr) != null)
2884	>	sr.parent = p;
2885	>	if ((s.left = pl) != null)
2886	>	pl.parent = s;
2887	>	if ((s.parent = pp) == null)
2888	>	r = s;
2889	>	else if (p == pp.left)
2890	>	pp.left = s;
2891	>	else
2892	>	pp.right = s;
2893	>	if (sr != null)
2894	>	replacement = sr;
2895	>	else
2896	>	replacement = p;
2897	>	}
2898	>	else if (pl != null)
2899	>	replacement = pl;
2900	>	else if (pr != null)
2901	>	replacement = pr;
2902	>	else
2903	>	replacement = p;
2904	>	if (replacement != p) {
2905	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2906	>	if (pp == null)
2907	>	r = replacement;
2908	>	else if (p == pp.left)
2909	>	pp.left = replacement;
2910	>	else
2911	>	pp.right = replacement;
2912	>	p.left = p.right = p.parent = null;
2913	>	}
2914	>
2915	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2916	>
2917	>	if (p == replacement) {  // detach pointers
2918	>	TreeNode<K,V> pp;
2919	>	if ((pp = p.parent) != null) {
2920	>	if (p == pp.left)
2921	>	pp.left = null;
2922	>	else if (p == pp.right)
2923	>	pp.right = null;
2924	>	p.parent = null;
2925	>	}
2926	>	}
2927	>	} finally {
2928	>	unlockRoot();
2929	>	}
2930	>	assert checkInvariants(root);
2931	>	return false;
2932	>	}
2933	>
2934	>	/* ------------------------------------------------------------ */
2935	>	// Red-black tree methods, all adapted from CLR
2936	>
2937	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
2938	>	TreeNode<K,V> p) {
2939	>	TreeNode<K,V> r, pp, rl;
2940	>	if (p != null && (r = p.right) != null) {
2941	>	if ((rl = p.right = r.left) != null)
2942	>	rl.parent = p;
2943	>	if ((pp = r.parent = p.parent) == null)
2944	>	(root = r).red = false;
2945	>	else if (pp.left == p)
2946	>	pp.left = r;
2947	>	else
2948	>	pp.right = r;
2949	>	r.left = p;
2950	>	p.parent = r;
2951	>	}
2952	>	return root;
2953	>	}
2954	>
2955	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
2956	>	TreeNode<K,V> p) {
2957	>	TreeNode<K,V> l, pp, lr;
2958	>	if (p != null && (l = p.left) != null) {
2959	>	if ((lr = p.left = l.right) != null)
2960	>	lr.parent = p;
2961	>	if ((pp = l.parent = p.parent) == null)
2962	>	(root = l).red = false;
2963	>	else if (pp.right == p)
2964	>	pp.right = l;
2965	>	else
2966	>	pp.left = l;
2967	>	l.right = p;
2968	>	p.parent = l;
2969	>	}
2970	>	return root;
2971		}
2972
2973	<	public final boolean hasNext() { return nextEntry != null; }
2974	<	public final boolean hasMoreElements() { return nextEntry != null; }
2973	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
2974	>	TreeNode<K,V> x) {
2975	>	x.red = true;
2976	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
2977	>	if ((xp = x.parent) == null) {
2978	>	x.red = false;
2979	>	return x;
2980	>	}
2981	>	else if (!xp.red || (xpp = xp.parent) == null)
2982	>	return root;
2983	>	if (xp == (xppl = xpp.left)) {
2984	>	if ((xppr = xpp.right) != null && xppr.red) {
2985	>	xppr.red = false;
2986	>	xp.red = false;
2987	>	xpp.red = true;
2988	>	x = xpp;
2989	>	}
2990	>	else {
2991	>	if (x == xp.right) {
2992	>	root = rotateLeft(root, x = xp);
2993	>	xpp = (xp = x.parent) == null ? null : xp.parent;
2994	>	}
2995	>	if (xp != null) {
2996	>	xp.red = false;
2997	>	if (xpp != null) {
2998	>	xpp.red = true;
2999	>	root = rotateRight(root, xpp);
3000	>	}
3001	>	}
3002	>	}
3003	>	}
3004	>	else {
3005	>	if (xppl != null && xppl.red) {
3006	>	xppl.red = false;
3007	>	xp.red = false;
3008	>	xpp.red = true;
3009	>	x = xpp;
3010	>	}
3011	>	else {
3012	>	if (x == xp.left) {
3013	>	root = rotateRight(root, x = xp);
3014	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3015	>	}
3016	>	if (xp != null) {
3017	>	xp.red = false;
3018	>	if (xpp != null) {
3019	>	xpp.red = true;
3020	>	root = rotateLeft(root, xpp);
3021	>	}
3022	>	}
3023	>	}
3024	>	}
3025	>	}
3026	>	}
3027	>
3028	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3029	>	TreeNode<K,V> x) {
3030	>	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3031	>	if (x == null || x == root)
3032	>	return root;
3033	>	else if ((xp = x.parent) == null) {
3034	>	x.red = false;
3035	>	return x;
3036	>	}
3037	>	else if (x.red) {
3038	>	x.red = false;
3039	>	return root;
3040	>	}
3041	>	else if ((xpl = xp.left) == x) {
3042	>	if ((xpr = xp.right) != null && xpr.red) {
3043	>	xpr.red = false;
3044	>	xp.red = true;
3045	>	root = rotateLeft(root, xp);
3046	>	xpr = (xp = x.parent) == null ? null : xp.right;
3047	>	}
3048	>	if (xpr == null)
3049	>	x = xp;
3050	>	else {
3051	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3052	>	if ((sr == null || !sr.red) &&
3053	>	(sl == null || !sl.red)) {
3054	>	xpr.red = true;
3055	>	x = xp;
3056	>	}
3057	>	else {
3058	>	if (sr == null || !sr.red) {
3059	>	if (sl != null)
3060	>	sl.red = false;
3061	>	xpr.red = true;
3062	>	root = rotateRight(root, xpr);
3063	>	xpr = (xp = x.parent) == null ?
3064	>	null : xp.right;
3065	>	}
3066	>	if (xpr != null) {
3067	>	xpr.red = (xp == null) ? false : xp.red;
3068	>	if ((sr = xpr.right) != null)
3069	>	sr.red = false;
3070	>	}
3071	>	if (xp != null) {
3072	>	xp.red = false;
3073	>	root = rotateLeft(root, xp);
3074	>	}
3075	>	x = root;
3076	>	}
3077	>	}
3078	>	}
3079	>	else { // symmetric
3080	>	if (xpl != null && xpl.red) {
3081	>	xpl.red = false;
3082	>	xp.red = true;
3083	>	root = rotateRight(root, xp);
3084	>	xpl = (xp = x.parent) == null ? null : xp.left;
3085	>	}
3086	>	if (xpl == null)
3087	>	x = xp;
3088	>	else {
3089	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3090	>	if ((sl == null || !sl.red) &&
3091	>	(sr == null || !sr.red)) {
3092	>	xpl.red = true;
3093	>	x = xp;
3094	>	}
3095	>	else {
3096	>	if (sl == null || !sl.red) {
3097	>	if (sr != null)
3098	>	sr.red = false;
3099	>	xpl.red = true;
3100	>	root = rotateLeft(root, xpl);
3101	>	xpl = (xp = x.parent) == null ?
3102	>	null : xp.left;
3103	>	}
3104	>	if (xpl != null) {
3105	>	xpl.red = (xp == null) ? false : xp.red;
3106	>	if ((sl = xpl.left) != null)
3107	>	sl.red = false;
3108	>	}
3109	>	if (xp != null) {
3110	>	xp.red = false;
3111	>	root = rotateRight(root, xp);
3112	>	}
3113	>	x = root;
3114	>	}
3115	>	}
3116	>	}
3117	>	}
3118	>	}
3119	>
3120	>	/**
3121	>	* Recursive invariant check
3122	>	*/
3123	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3124	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3125	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3126	>	if (tb != null && tb.next != t)
3127	>	return false;
3128	>	if (tn != null && tn.prev != t)
3129	>	return false;
3130	>	if (tp != null && t != tp.left && t != tp.right)
3131	>	return false;
3132	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3133	>	return false;
3134	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3135	>	return false;
3136	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3137	>	return false;
3138	>	if (tl != null && !checkInvariants(tl))
3139	>	return false;
3140	>	if (tr != null && !checkInvariants(tr))
3141	>	return false;
3142	>	return true;
3143	>	}
3144	>
3145	>	private static final sun.misc.Unsafe U;
3146	>	private static final long LOCKSTATE;
3147	>	static {
3148	>	try {
3149	>	U = sun.misc.Unsafe.getUnsafe();
3150	>	Class<?> k = TreeBin.class;
3151	>	LOCKSTATE = U.objectFieldOffset
3152	>	(k.getDeclaredField("lockState"));
3153	>	} catch (Exception e) {
3154	>	throw new Error(e);
3155	>	}
3156	>	}
3157	>	}
3158	>
3159	>	/* ----------------Table Traversal -------------- */
3160	>
3161	>	/**
3162	>	* Encapsulates traversal for methods such as containsValue; also
3163	>	* serves as a base class for other iterators and spliterators.
3164	>	*
3165	>	* Method advance visits once each still-valid node that was
3166	>	* reachable upon iterator construction. It might miss some that
3167	>	* were added to a bin after the bin was visited, which is OK wrt
3168	>	* consistency guarantees. Maintaining this property in the face
3169	>	* of possible ongoing resizes requires a fair amount of
3170	>	* bookkeeping state that is difficult to optimize away amidst
3171	>	* volatile accesses.  Even so, traversal maintains reasonable
3172	>	* throughput.
3173	>	*
3174	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3175	>	* However, if the table has been resized, then all future steps
3176	>	* must traverse both the bin at the current index as well as at
3177	>	* (index + baseSize); and so on for further resizings. To
3178	>	* paranoically cope with potential sharing by users of iterators
3179	>	* across threads, iteration terminates if a bounds checks fails
3180	>	* for a table read.
3181	>	*/
3182	>	static class Traverser<K,V> {
3183	>	Node<K,V>[] tab;        // current table; updated if resized
3184	>	Node<K,V> next;         // the next entry to use
3185	>	int index;              // index of bin to use next
3186	>	int baseIndex;          // current index of initial table
3187	>	int baseLimit;          // index bound for initial table
3188	>	final int baseSize;     // initial table size
3189	>
3190	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3191	>	this.tab = tab;
3192	>	this.baseSize = size;
3193	>	this.baseIndex = this.index = index;
3194	>	this.baseLimit = limit;
3195	>	this.next = null;
3196	>	}
3197	>
3198	>	/**
3199	>	* Advances if possible, returning next valid node, or null if none.
3200	>	*/
3201	>	final Node<K,V> advance() {
3202	>	Node<K,V> e;
3203	>	if ((e = next) != null)
3204	>	e = e.next;
3205	>	for (;;) {
3206	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3207	>	if (e != null)
3208	>	return next = e;
3209	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3210	>	(n = t.length) <= (i = index) || i < 0)
3211	>	return next = null;
3212	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
3213	>	if (e instanceof ForwardingNode) {
3214	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3215	>	e = null;
3216	>	continue;
3217	>	}
3218	>	else if (e instanceof TreeBin)
3219	>	e = ((TreeBin<K,V>)e).first;
3220	>	else
3221	>	e = null;
3222	>	}
3223	>	if ((index += baseSize) >= n)
3224	>	index = ++baseIndex;    // visit upper slots if present
3225	>	}
3226	>	}
3227	>	}
3228	>
3229	>	/**
3230	>	* Base of key, value, and entry Iterators. Adds fields to
3231	>	* Traverser to support iterator.remove.
3232	>	*/
3233	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3234	>	final ConcurrentHashMap<K,V> map;
3235	>	Node<K,V> lastReturned;
3236	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3237	>	ConcurrentHashMap<K,V> map) {
3238	>	super(tab, size, index, limit);
3239	>	this.map = map;
3240	>	advance();
3241	>	}
3242	>
3243	>	public final boolean hasNext() { return next != null; }
3244	>	public final boolean hasMoreElements() { return next != null; }
3245
3246		public final void remove() {
3247	<	if (lastReturned == null)
3247	>	Node<K,V> p;
3248	>	if ((p = lastReturned) == null)
3249		throw new IllegalStateException();
1271	–	ConcurrentHashMap.this.remove(lastReturned.key);
3250		lastReturned = null;
3251	+	map.replaceNode(p.key, null, null);
3252		}
3253		}
3254
3255	<	final class KeyIterator
3256	<	extends HashIterator
3257	<	implements Iterator<K>, Enumeration<K>
3258	<	{
3259	<	public final K next()        { return super.nextEntry().key; }
3260	<	public final K nextElement() { return super.nextEntry().key; }
3261	<	}
3262	<
3263	<	final class ValueIterator
3264	<	extends HashIterator
3265	<	implements Iterator<V>, Enumeration<V>
3266	<	{
3267	<	public final V next()        { return super.nextEntry().value; }
3268	<	public final V nextElement() { return super.nextEntry().value; }
3255	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3256	>	implements Iterator<K>, Enumeration<K> {
3257	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3258	>	ConcurrentHashMap<K,V> map) {
3259	>	super(tab, index, size, limit, map);
3260	>	}
3261	>
3262	>	public final K next() {
3263	>	Node<K,V> p;
3264	>	if ((p = next) == null)
3265	>	throw new NoSuchElementException();
3266	>	K k = p.key;
3267	>	lastReturned = p;
3268	>	advance();
3269	>	return k;
3270	>	}
3271	>
3272	>	public final K nextElement() { return next(); }
3273	>	}
3274	>
3275	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3276	>	implements Iterator<V>, Enumeration<V> {
3277	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3278	>	ConcurrentHashMap<K,V> map) {
3279	>	super(tab, index, size, limit, map);
3280	>	}
3281	>
3282	>	public final V next() {
3283	>	Node<K,V> p;
3284	>	if ((p = next) == null)
3285	>	throw new NoSuchElementException();
3286	>	V v = p.val;
3287	>	lastReturned = p;
3288	>	advance();
3289	>	return v;
3290	>	}
3291	>
3292	>	public final V nextElement() { return next(); }
3293	>	}
3294	>
3295	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3296	>	implements Iterator<Map.Entry<K,V>> {
3297	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3298	>	ConcurrentHashMap<K,V> map) {
3299	>	super(tab, index, size, limit, map);
3300	>	}
3301	>
3302	>	public final Map.Entry<K,V> next() {
3303	>	Node<K,V> p;
3304	>	if ((p = next) == null)
3305	>	throw new NoSuchElementException();
3306	>	K k = p.key;
3307	>	V v = p.val;
3308	>	lastReturned = p;
3309	>	advance();
3310	>	return new MapEntry<K,V>(k, v, map);
3311	>	}
3312		}
3313
3314		/**
3315	<	* Custom Entry class used by EntryIterator.next(), that relays
3316	<	* setValue changes to the underlying map.
3317	<	*/
3318	<	final class WriteThroughEntry
3319	<	extends AbstractMap.SimpleEntry<K,V>
3320	<	{
3321	<	WriteThroughEntry(K k, V v) {
3322	<	super(k,v);
3315	>	* Exported Entry for EntryIterator
3316	>	*/
3317	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3318	>	final K key; // non-null
3319	>	V val;       // non-null
3320	>	final ConcurrentHashMap<K,V> map;
3321	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3322	>	this.key = key;
3323	>	this.val = val;
3324	>	this.map = map;
3325	>	}
3326	>	public K getKey()        { return key; }
3327	>	public V getValue()      { return val; }
3328	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3329	>	public String toString() { return key + "=" + val; }
3330	>
3331	>	public boolean equals(Object o) {
3332	>	Object k, v; Map.Entry<?,?> e;
3333	>	return ((o instanceof Map.Entry) &&
3334	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3335	>	(v = e.getValue()) != null &&
3336	>	(k == key || k.equals(key)) &&
3337	>	(v == val || v.equals(val)));
3338		}
3339
3340		/**
3341		* Sets our entry's value and writes through to the map. The
3342	<	* value to return is somewhat arbitrary here. Since a
3343	<	* WriteThroughEntry does not necessarily track asynchronous
3344	<	* changes, the most recent "previous" value could be
3345	<	* different from what we return (or could even have been
3346	<	* removed in which case the put will re-establish). We do not
1310	<	* and cannot guarantee more.
3342	>	* value to return is somewhat arbitrary here. Since we do not
3343	>	* necessarily track asynchronous changes, the most recent
3344	>	* "previous" value could be different from what we return (or
3345	>	* could even have been removed, in which case the put will
3346	>	* re-establish). We do not and cannot guarantee more.
3347		*/
3348		public V setValue(V value) {
3349		if (value == null) throw new NullPointerException();
3350	<	V v = super.setValue(value);
3351	<	ConcurrentHashMap.this.put(getKey(), value);
3350	>	V v = val;
3351	>	val = value;
3352	>	map.put(key, value);
3353		return v;
3354		}
3355		}
3356
3357	<	final class EntryIterator
3358	<	extends HashIterator
3359	<	implements Iterator<Entry<K,V>>
3360	<	{
3361	<	public Map.Entry<K,V> next() {
3362	<	HashEntry<K,V> e = super.nextEntry();
3363	<	return new WriteThroughEntry(e.key, e.value);
3357	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3358	>	implements Spliterator<K> {
3359	>	long est;               // size estimate
3360	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3361	>	long est) {
3362	>	super(tab, size, index, limit);
3363	>	this.est = est;
3364	>	}
3365	>
3366	>	public Spliterator<K> trySplit() {
3367	>	int i, f, h;
3368	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3369	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3370	>	f, est >>>= 1);
3371	>	}
3372	>
3373	>	public void forEachRemaining(Consumer<? super K> action) {
3374	>	if (action == null) throw new NullPointerException();
3375	>	for (Node<K,V> p; (p = advance()) != null;)
3376	>	action.accept(p.key);
3377	>	}
3378	>
3379	>	public boolean tryAdvance(Consumer<? super K> action) {
3380	>	if (action == null) throw new NullPointerException();
3381	>	Node<K,V> p;
3382	>	if ((p = advance()) == null)
3383	>	return false;
3384	>	action.accept(p.key);
3385	>	return true;
3386	>	}
3387	>
3388	>	public long estimateSize() { return est; }
3389	>
3390	>	public int characteristics() {
3391	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3392	>	Spliterator.NONNULL;
3393		}
3394		}
3395
3396	<	final class KeySet extends AbstractSet<K> {
3397	<	public Iterator<K> iterator() {
3398	<	return new KeyIterator();
3396	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3397	>	implements Spliterator<V> {
3398	>	long est;               // size estimate
3399	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3400	>	long est) {
3401	>	super(tab, size, index, limit);
3402	>	this.est = est;
3403		}
3404	<	public int size() {
3405	<	return ConcurrentHashMap.this.size();
3404	>
3405	>	public Spliterator<V> trySplit() {
3406	>	int i, f, h;
3407	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3408	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3409	>	f, est >>>= 1);
3410		}
3411	<	public boolean isEmpty() {
3412	<	return ConcurrentHashMap.this.isEmpty();
3411	>
3412	>	public void forEachRemaining(Consumer<? super V> action) {
3413	>	if (action == null) throw new NullPointerException();
3414	>	for (Node<K,V> p; (p = advance()) != null;)
3415	>	action.accept(p.val);
3416		}
3417	<	public boolean contains(Object o) {
3418	<	return ConcurrentHashMap.this.containsKey(o);
3417	>
3418	>	public boolean tryAdvance(Consumer<? super V> action) {
3419	>	if (action == null) throw new NullPointerException();
3420	>	Node<K,V> p;
3421	>	if ((p = advance()) == null)
3422	>	return false;
3423	>	action.accept(p.val);
3424	>	return true;
3425		}
3426	<	public boolean remove(Object o) {
3427	<	return ConcurrentHashMap.this.remove(o) != null;
3426	>
3427	>	public long estimateSize() { return est; }
3428	>
3429	>	public int characteristics() {
3430	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3431	>	}
3432	>	}
3433	>
3434	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3435	>	implements Spliterator<Map.Entry<K,V>> {
3436	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3437	>	long est;               // size estimate
3438	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3439	>	long est, ConcurrentHashMap<K,V> map) {
3440	>	super(tab, size, index, limit);
3441	>	this.map = map;
3442	>	this.est = est;
3443	>	}
3444	>
3445	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3446	>	int i, f, h;
3447	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3448	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3449	>	f, est >>>= 1, map);
3450	>	}
3451	>
3452	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3453	>	if (action == null) throw new NullPointerException();
3454	>	for (Node<K,V> p; (p = advance()) != null; )
3455	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3456	>	}
3457	>
3458	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3459	>	if (action == null) throw new NullPointerException();
3460	>	Node<K,V> p;
3461	>	if ((p = advance()) == null)
3462	>	return false;
3463	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3464	>	return true;
3465	>	}
3466	>
3467	>	public long estimateSize() { return est; }
3468	>
3469	>	public int characteristics() {
3470	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3471	>	Spliterator.NONNULL;
3472	>	}
3473	>	}
3474	>
3475	>	// Parallel bulk operations
3476	>
3477	>	/**
3478	>	* Computes initial batch value for bulk tasks. The returned value
3479	>	* is approximately exp2 of the number of times (minus one) to
3480	>	* split task by two before executing leaf action. This value is
3481	>	* faster to compute and more convenient to use as a guide to
3482	>	* splitting than is the depth, since it is used while dividing by
3483	>	* two anyway.
3484	>	*/
3485	>	final int batchFor(long b) {
3486	>	long n;
3487	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3488	>	return 0;
3489	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3490	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3491	>	}
3492	>
3493	>	/**
3494	>	* Performs the given action for each (key, value).
3495	>	*
3496	>	* @param parallelismThreshold the (estimated) number of elements
3497	>	* needed for this operation to be executed in parallel
3498	>	* @param action the action
3499	>	* @since 1.8
3500	>	*/
3501	>	public void forEach(long parallelismThreshold,
3502	>	BiConsumer<? super K,? super V> action) {
3503	>	if (action == null) throw new NullPointerException();
3504	>	new ForEachMappingTask<K,V>
3505	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3506	>	action).invoke();
3507	>	}
3508	>
3509	>	/**
3510	>	* Performs the given action for each non-null transformation
3511	>	* of each (key, value).
3512	>	*
3513	>	* @param parallelismThreshold the (estimated) number of elements
3514	>	* needed for this operation to be executed in parallel
3515	>	* @param transformer a function returning the transformation
3516	>	* for an element, or null if there is no transformation (in
3517	>	* which case the action is not applied)
3518	>	* @param action the action
3519	>	* @since 1.8
3520	>	*/
3521	>	public <U> void forEach(long parallelismThreshold,
3522	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3523	>	Consumer<? super U> action) {
3524	>	if (transformer == null || action == null)
3525	>	throw new NullPointerException();
3526	>	new ForEachTransformedMappingTask<K,V,U>
3527	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3528	>	transformer, action).invoke();
3529	>	}
3530	>
3531	>	/**
3532	>	* Returns a non-null result from applying the given search
3533	>	* function on each (key, value), or null if none.  Upon
3534	>	* success, further element processing is suppressed and the
3535	>	* results of any other parallel invocations of the search
3536	>	* function are ignored.
3537	>	*
3538	>	* @param parallelismThreshold the (estimated) number of elements
3539	>	* needed for this operation to be executed in parallel
3540	>	* @param searchFunction a function returning a non-null
3541	>	* result on success, else null
3542	>	* @return a non-null result from applying the given search
3543	>	* function on each (key, value), or null if none
3544	>	* @since 1.8
3545	>	*/
3546	>	public <U> U search(long parallelismThreshold,
3547	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3548	>	if (searchFunction == null) throw new NullPointerException();
3549	>	return new SearchMappingsTask<K,V,U>
3550	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3551	>	searchFunction, new AtomicReference<U>()).invoke();
3552	>	}
3553	>
3554	>	/**
3555	>	* Returns the result of accumulating the given transformation
3556	>	* of all (key, value) pairs using the given reducer to
3557	>	* combine values, or null if none.
3558	>	*
3559	>	* @param parallelismThreshold the (estimated) number of elements
3560	>	* needed for this operation to be executed in parallel
3561	>	* @param transformer a function returning the transformation
3562	>	* for an element, or null if there is no transformation (in
3563	>	* which case it is not combined)
3564	>	* @param reducer a commutative associative combining function
3565	>	* @return the result of accumulating the given transformation
3566	>	* of all (key, value) pairs
3567	>	* @since 1.8
3568	>	*/
3569	>	public <U> U reduce(long parallelismThreshold,
3570	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3571	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3572	>	if (transformer == null || reducer == null)
3573	>	throw new NullPointerException();
3574	>	return new MapReduceMappingsTask<K,V,U>
3575	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3576	>	null, transformer, reducer).invoke();
3577	>	}
3578	>
3579	>	/**
3580	>	* Returns the result of accumulating the given transformation
3581	>	* of all (key, value) pairs using the given reducer to
3582	>	* combine values, and the given basis as an identity value.
3583	>	*
3584	>	* @param parallelismThreshold the (estimated) number of elements
3585	>	* needed for this operation to be executed in parallel
3586	>	* @param transformer a function returning the transformation
3587	>	* for an element
3588	>	* @param basis the identity (initial default value) for the reduction
3589	>	* @param reducer a commutative associative combining function
3590	>	* @return the result of accumulating the given transformation
3591	>	* of all (key, value) pairs
3592	>	* @since 1.8
3593	>	*/
3594	>	public double reduceToDouble(long parallelismThreshold,
3595	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3596	>	double basis,
3597	>	DoubleBinaryOperator reducer) {
3598	>	if (transformer == null || reducer == null)
3599	>	throw new NullPointerException();
3600	>	return new MapReduceMappingsToDoubleTask<K,V>
3601	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3602	>	null, transformer, basis, reducer).invoke();
3603	>	}
3604	>
3605	>	/**
3606	>	* Returns the result of accumulating the given transformation
3607	>	* of all (key, value) pairs using the given reducer to
3608	>	* combine values, and the given basis as an identity value.
3609	>	*
3610	>	* @param parallelismThreshold the (estimated) number of elements
3611	>	* needed for this operation to be executed in parallel
3612	>	* @param transformer a function returning the transformation
3613	>	* for an element
3614	>	* @param basis the identity (initial default value) for the reduction
3615	>	* @param reducer a commutative associative combining function
3616	>	* @return the result of accumulating the given transformation
3617	>	* of all (key, value) pairs
3618	>	* @since 1.8
3619	>	*/
3620	>	public long reduceToLong(long parallelismThreshold,
3621	>	ToLongBiFunction<? super K, ? super V> transformer,
3622	>	long basis,
3623	>	LongBinaryOperator reducer) {
3624	>	if (transformer == null || reducer == null)
3625	>	throw new NullPointerException();
3626	>	return new MapReduceMappingsToLongTask<K,V>
3627	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3628	>	null, transformer, basis, reducer).invoke();
3629	>	}
3630	>
3631	>	/**
3632	>	* Returns the result of accumulating the given transformation
3633	>	* of all (key, value) pairs using the given reducer to
3634	>	* combine values, and the given basis as an identity value.
3635	>	*
3636	>	* @param parallelismThreshold the (estimated) number of elements
3637	>	* needed for this operation to be executed in parallel
3638	>	* @param transformer a function returning the transformation
3639	>	* for an element
3640	>	* @param basis the identity (initial default value) for the reduction
3641	>	* @param reducer a commutative associative combining function
3642	>	* @return the result of accumulating the given transformation
3643	>	* of all (key, value) pairs
3644	>	* @since 1.8
3645	>	*/
3646	>	public int reduceToInt(long parallelismThreshold,
3647	>	ToIntBiFunction<? super K, ? super V> transformer,
3648	>	int basis,
3649	>	IntBinaryOperator reducer) {
3650	>	if (transformer == null || reducer == null)
3651	>	throw new NullPointerException();
3652	>	return new MapReduceMappingsToIntTask<K,V>
3653	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3654	>	null, transformer, basis, reducer).invoke();
3655	>	}
3656	>
3657	>	/**
3658	>	* Performs the given action for each key.
3659	>	*
3660	>	* @param parallelismThreshold the (estimated) number of elements
3661	>	* needed for this operation to be executed in parallel
3662	>	* @param action the action
3663	>	* @since 1.8
3664	>	*/
3665	>	public void forEachKey(long parallelismThreshold,
3666	>	Consumer<? super K> action) {
3667	>	if (action == null) throw new NullPointerException();
3668	>	new ForEachKeyTask<K,V>
3669	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3670	>	action).invoke();
3671	>	}
3672	>
3673	>	/**
3674	>	* Performs the given action for each non-null transformation
3675	>	* of each key.
3676	>	*
3677	>	* @param parallelismThreshold the (estimated) number of elements
3678	>	* needed for this operation to be executed in parallel
3679	>	* @param transformer a function returning the transformation
3680	>	* for an element, or null if there is no transformation (in
3681	>	* which case the action is not applied)
3682	>	* @param action the action
3683	>	* @since 1.8
3684	>	*/
3685	>	public <U> void forEachKey(long parallelismThreshold,
3686	>	Function<? super K, ? extends U> transformer,
3687	>	Consumer<? super U> action) {
3688	>	if (transformer == null || action == null)
3689	>	throw new NullPointerException();
3690	>	new ForEachTransformedKeyTask<K,V,U>
3691	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3692	>	transformer, action).invoke();
3693	>	}
3694	>
3695	>	/**
3696	>	* Returns a non-null result from applying the given search
3697	>	* function on each key, or null if none. Upon success,
3698	>	* further element processing is suppressed and the results of
3699	>	* any other parallel invocations of the search function are
3700	>	* ignored.
3701	>	*
3702	>	* @param parallelismThreshold the (estimated) number of elements
3703	>	* needed for this operation to be executed in parallel
3704	>	* @param searchFunction a function returning a non-null
3705	>	* result on success, else null
3706	>	* @return a non-null result from applying the given search
3707	>	* function on each key, or null if none
3708	>	* @since 1.8
3709	>	*/
3710	>	public <U> U searchKeys(long parallelismThreshold,
3711	>	Function<? super K, ? extends U> searchFunction) {
3712	>	if (searchFunction == null) throw new NullPointerException();
3713	>	return new SearchKeysTask<K,V,U>
3714	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3715	>	searchFunction, new AtomicReference<U>()).invoke();
3716	>	}
3717	>
3718	>	/**
3719	>	* Returns the result of accumulating all keys using the given
3720	>	* reducer to combine values, or null if none.
3721	>	*
3722	>	* @param parallelismThreshold the (estimated) number of elements
3723	>	* needed for this operation to be executed in parallel
3724	>	* @param reducer a commutative associative combining function
3725	>	* @return the result of accumulating all keys using the given
3726	>	* reducer to combine values, or null if none
3727	>	* @since 1.8
3728	>	*/
3729	>	public K reduceKeys(long parallelismThreshold,
3730	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3731	>	if (reducer == null) throw new NullPointerException();
3732	>	return new ReduceKeysTask<K,V>
3733	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3734	>	null, reducer).invoke();
3735	>	}
3736	>
3737	>	/**
3738	>	* Returns the result of accumulating the given transformation
3739	>	* of all keys using the given reducer to combine values, or
3740	>	* null if none.
3741	>	*
3742	>	* @param parallelismThreshold the (estimated) number of elements
3743	>	* needed for this operation to be executed in parallel
3744	>	* @param transformer a function returning the transformation
3745	>	* for an element, or null if there is no transformation (in
3746	>	* which case it is not combined)
3747	>	* @param reducer a commutative associative combining function
3748	>	* @return the result of accumulating the given transformation
3749	>	* of all keys
3750	>	* @since 1.8
3751	>	*/
3752	>	public <U> U reduceKeys(long parallelismThreshold,
3753	>	Function<? super K, ? extends U> transformer,
3754	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3755	>	if (transformer == null || reducer == null)
3756	>	throw new NullPointerException();
3757	>	return new MapReduceKeysTask<K,V,U>
3758	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3759	>	null, transformer, reducer).invoke();
3760	>	}
3761	>
3762	>	/**
3763	>	* Returns the result of accumulating the given transformation
3764	>	* of all keys using the given reducer to combine values, and
3765	>	* the given basis as an identity value.
3766	>	*
3767	>	* @param parallelismThreshold the (estimated) number of elements
3768	>	* needed for this operation to be executed in parallel
3769	>	* @param transformer a function returning the transformation
3770	>	* for an element
3771	>	* @param basis the identity (initial default value) for the reduction
3772	>	* @param reducer a commutative associative combining function
3773	>	* @return the result of accumulating the given transformation
3774	>	* of all keys
3775	>	* @since 1.8
3776	>	*/
3777	>	public double reduceKeysToDouble(long parallelismThreshold,
3778	>	ToDoubleFunction<? super K> transformer,
3779	>	double basis,
3780	>	DoubleBinaryOperator reducer) {
3781	>	if (transformer == null || reducer == null)
3782	>	throw new NullPointerException();
3783	>	return new MapReduceKeysToDoubleTask<K,V>
3784	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3785	>	null, transformer, basis, reducer).invoke();
3786	>	}
3787	>
3788	>	/**
3789	>	* Returns the result of accumulating the given transformation
3790	>	* of all keys using the given reducer to combine values, and
3791	>	* the given basis as an identity value.
3792	>	*
3793	>	* @param parallelismThreshold the (estimated) number of elements
3794	>	* needed for this operation to be executed in parallel
3795	>	* @param transformer a function returning the transformation
3796	>	* for an element
3797	>	* @param basis the identity (initial default value) for the reduction
3798	>	* @param reducer a commutative associative combining function
3799	>	* @return the result of accumulating the given transformation
3800	>	* of all keys
3801	>	* @since 1.8
3802	>	*/
3803	>	public long reduceKeysToLong(long parallelismThreshold,
3804	>	ToLongFunction<? super K> transformer,
3805	>	long basis,
3806	>	LongBinaryOperator reducer) {
3807	>	if (transformer == null || reducer == null)
3808	>	throw new NullPointerException();
3809	>	return new MapReduceKeysToLongTask<K,V>
3810	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3811	>	null, transformer, basis, reducer).invoke();
3812	>	}
3813	>
3814	>	/**
3815	>	* Returns the result of accumulating the given transformation
3816	>	* of all keys using the given reducer to combine values, and
3817	>	* the given basis as an identity value.
3818	>	*
3819	>	* @param parallelismThreshold the (estimated) number of elements
3820	>	* needed for this operation to be executed in parallel
3821	>	* @param transformer a function returning the transformation
3822	>	* for an element
3823	>	* @param basis the identity (initial default value) for the reduction
3824	>	* @param reducer a commutative associative combining function
3825	>	* @return the result of accumulating the given transformation
3826	>	* of all keys
3827	>	* @since 1.8
3828	>	*/
3829	>	public int reduceKeysToInt(long parallelismThreshold,
3830	>	ToIntFunction<? super K> transformer,
3831	>	int basis,
3832	>	IntBinaryOperator reducer) {
3833	>	if (transformer == null || reducer == null)
3834	>	throw new NullPointerException();
3835	>	return new MapReduceKeysToIntTask<K,V>
3836	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3837	>	null, transformer, basis, reducer).invoke();
3838	>	}
3839	>
3840	>	/**
3841	>	* Performs the given action for each value.
3842	>	*
3843	>	* @param parallelismThreshold the (estimated) number of elements
3844	>	* needed for this operation to be executed in parallel
3845	>	* @param action the action
3846	>	* @since 1.8
3847	>	*/
3848	>	public void forEachValue(long parallelismThreshold,
3849	>	Consumer<? super V> action) {
3850	>	if (action == null)
3851	>	throw new NullPointerException();
3852	>	new ForEachValueTask<K,V>
3853	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3854	>	action).invoke();
3855	>	}
3856	>
3857	>	/**
3858	>	* Performs the given action for each non-null transformation
3859	>	* of each value.
3860	>	*
3861	>	* @param parallelismThreshold the (estimated) number of elements
3862	>	* needed for this operation to be executed in parallel
3863	>	* @param transformer a function returning the transformation
3864	>	* for an element, or null if there is no transformation (in
3865	>	* which case the action is not applied)
3866	>	* @param action the action
3867	>	* @since 1.8
3868	>	*/
3869	>	public <U> void forEachValue(long parallelismThreshold,
3870	>	Function<? super V, ? extends U> transformer,
3871	>	Consumer<? super U> action) {
3872	>	if (transformer == null || action == null)
3873	>	throw new NullPointerException();
3874	>	new ForEachTransformedValueTask<K,V,U>
3875	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3876	>	transformer, action).invoke();
3877	>	}
3878	>
3879	>	/**
3880	>	* Returns a non-null result from applying the given search
3881	>	* function on each value, or null if none.  Upon success,
3882	>	* further element processing is suppressed and the results of
3883	>	* any other parallel invocations of the search function are
3884	>	* ignored.
3885	>	*
3886	>	* @param parallelismThreshold the (estimated) number of elements
3887	>	* needed for this operation to be executed in parallel
3888	>	* @param searchFunction a function returning a non-null
3889	>	* result on success, else null
3890	>	* @return a non-null result from applying the given search
3891	>	* function on each value, or null if none
3892	>	* @since 1.8
3893	>	*/
3894	>	public <U> U searchValues(long parallelismThreshold,
3895	>	Function<? super V, ? extends U> searchFunction) {
3896	>	if (searchFunction == null) throw new NullPointerException();
3897	>	return new SearchValuesTask<K,V,U>
3898	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3899	>	searchFunction, new AtomicReference<U>()).invoke();
3900	>	}
3901	>
3902	>	/**
3903	>	* Returns the result of accumulating all values using the
3904	>	* given reducer to combine values, or null if none.
3905	>	*
3906	>	* @param parallelismThreshold the (estimated) number of elements
3907	>	* needed for this operation to be executed in parallel
3908	>	* @param reducer a commutative associative combining function
3909	>	* @return the result of accumulating all values
3910	>	* @since 1.8
3911	>	*/
3912	>	public V reduceValues(long parallelismThreshold,
3913	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
3914	>	if (reducer == null) throw new NullPointerException();
3915	>	return new ReduceValuesTask<K,V>
3916	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3917	>	null, reducer).invoke();
3918	>	}
3919	>
3920	>	/**
3921	>	* Returns the result of accumulating the given transformation
3922	>	* of all values using the given reducer to combine values, or
3923	>	* null if none.
3924	>	*
3925	>	* @param parallelismThreshold the (estimated) number of elements
3926	>	* needed for this operation to be executed in parallel
3927	>	* @param transformer a function returning the transformation
3928	>	* for an element, or null if there is no transformation (in
3929	>	* which case it is not combined)
3930	>	* @param reducer a commutative associative combining function
3931	>	* @return the result of accumulating the given transformation
3932	>	* of all values
3933	>	* @since 1.8
3934	>	*/
3935	>	public <U> U reduceValues(long parallelismThreshold,
3936	>	Function<? super V, ? extends U> transformer,
3937	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3938	>	if (transformer == null || reducer == null)
3939	>	throw new NullPointerException();
3940	>	return new MapReduceValuesTask<K,V,U>
3941	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3942	>	null, transformer, reducer).invoke();
3943	>	}
3944	>
3945	>	/**
3946	>	* Returns the result of accumulating the given transformation
3947	>	* of all values using the given reducer to combine values,
3948	>	* and the given basis as an identity value.
3949	>	*
3950	>	* @param parallelismThreshold the (estimated) number of elements
3951	>	* needed for this operation to be executed in parallel
3952	>	* @param transformer a function returning the transformation
3953	>	* for an element
3954	>	* @param basis the identity (initial default value) for the reduction
3955	>	* @param reducer a commutative associative combining function
3956	>	* @return the result of accumulating the given transformation
3957	>	* of all values
3958	>	* @since 1.8
3959	>	*/
3960	>	public double reduceValuesToDouble(long parallelismThreshold,
3961	>	ToDoubleFunction<? super V> transformer,
3962	>	double basis,
3963	>	DoubleBinaryOperator reducer) {
3964	>	if (transformer == null || reducer == null)
3965	>	throw new NullPointerException();
3966	>	return new MapReduceValuesToDoubleTask<K,V>
3967	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3968	>	null, transformer, basis, reducer).invoke();
3969	>	}
3970	>
3971	>	/**
3972	>	* Returns the result of accumulating the given transformation
3973	>	* of all values using the given reducer to combine values,
3974	>	* and the given basis as an identity value.
3975	>	*
3976	>	* @param parallelismThreshold the (estimated) number of elements
3977	>	* needed for this operation to be executed in parallel
3978	>	* @param transformer a function returning the transformation
3979	>	* for an element
3980	>	* @param basis the identity (initial default value) for the reduction
3981	>	* @param reducer a commutative associative combining function
3982	>	* @return the result of accumulating the given transformation
3983	>	* of all values
3984	>	* @since 1.8
3985	>	*/
3986	>	public long reduceValuesToLong(long parallelismThreshold,
3987	>	ToLongFunction<? super V> transformer,
3988	>	long basis,
3989	>	LongBinaryOperator reducer) {
3990	>	if (transformer == null || reducer == null)
3991	>	throw new NullPointerException();
3992	>	return new MapReduceValuesToLongTask<K,V>
3993	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3994	>	null, transformer, basis, reducer).invoke();
3995	>	}
3996	>
3997	>	/**
3998	>	* Returns the result of accumulating the given transformation
3999	>	* of all values using the given reducer to combine values,
4000	>	* and the given basis as an identity value.
4001	>	*
4002	>	* @param parallelismThreshold the (estimated) number of elements
4003	>	* needed for this operation to be executed in parallel
4004	>	* @param transformer a function returning the transformation
4005	>	* for an element
4006	>	* @param basis the identity (initial default value) for the reduction
4007	>	* @param reducer a commutative associative combining function
4008	>	* @return the result of accumulating the given transformation
4009	>	* of all values
4010	>	* @since 1.8
4011	>	*/
4012	>	public int reduceValuesToInt(long parallelismThreshold,
4013	>	ToIntFunction<? super V> transformer,
4014	>	int basis,
4015	>	IntBinaryOperator reducer) {
4016	>	if (transformer == null || reducer == null)
4017	>	throw new NullPointerException();
4018	>	return new MapReduceValuesToIntTask<K,V>
4019	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4020	>	null, transformer, basis, reducer).invoke();
4021	>	}
4022	>
4023	>	/**
4024	>	* Performs the given action for each entry.
4025	>	*
4026	>	* @param parallelismThreshold the (estimated) number of elements
4027	>	* needed for this operation to be executed in parallel
4028	>	* @param action the action
4029	>	* @since 1.8
4030	>	*/
4031	>	public void forEachEntry(long parallelismThreshold,
4032	>	Consumer<? super Map.Entry<K,V>> action) {
4033	>	if (action == null) throw new NullPointerException();
4034	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4035	>	action).invoke();
4036	>	}
4037	>
4038	>	/**
4039	>	* Performs the given action for each non-null transformation
4040	>	* of each entry.
4041	>	*
4042	>	* @param parallelismThreshold the (estimated) number of elements
4043	>	* needed for this operation to be executed in parallel
4044	>	* @param transformer a function returning the transformation
4045	>	* for an element, or null if there is no transformation (in
4046	>	* which case the action is not applied)
4047	>	* @param action the action
4048	>	* @since 1.8
4049	>	*/
4050	>	public <U> void forEachEntry(long parallelismThreshold,
4051	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4052	>	Consumer<? super U> action) {
4053	>	if (transformer == null || action == null)
4054	>	throw new NullPointerException();
4055	>	new ForEachTransformedEntryTask<K,V,U>
4056	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4057	>	transformer, action).invoke();
4058	>	}
4059	>
4060	>	/**
4061	>	* Returns a non-null result from applying the given search
4062	>	* function on each entry, or null if none.  Upon success,
4063	>	* further element processing is suppressed and the results of
4064	>	* any other parallel invocations of the search function are
4065	>	* ignored.
4066	>	*
4067	>	* @param parallelismThreshold the (estimated) number of elements
4068	>	* needed for this operation to be executed in parallel
4069	>	* @param searchFunction a function returning a non-null
4070	>	* result on success, else null
4071	>	* @return a non-null result from applying the given search
4072	>	* function on each entry, or null if none
4073	>	* @since 1.8
4074	>	*/
4075	>	public <U> U searchEntries(long parallelismThreshold,
4076	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4077	>	if (searchFunction == null) throw new NullPointerException();
4078	>	return new SearchEntriesTask<K,V,U>
4079	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4080	>	searchFunction, new AtomicReference<U>()).invoke();
4081	>	}
4082	>
4083	>	/**
4084	>	* Returns the result of accumulating all entries using the
4085	>	* given reducer to combine values, or null if none.
4086	>	*
4087	>	* @param parallelismThreshold the (estimated) number of elements
4088	>	* needed for this operation to be executed in parallel
4089	>	* @param reducer a commutative associative combining function
4090	>	* @return the result of accumulating all entries
4091	>	* @since 1.8
4092	>	*/
4093	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4094	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4095	>	if (reducer == null) throw new NullPointerException();
4096	>	return new ReduceEntriesTask<K,V>
4097	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4098	>	null, reducer).invoke();
4099	>	}
4100	>
4101	>	/**
4102	>	* Returns the result of accumulating the given transformation
4103	>	* of all entries using the given reducer to combine values,
4104	>	* or null if none.
4105	>	*
4106	>	* @param parallelismThreshold the (estimated) number of elements
4107	>	* needed for this operation to be executed in parallel
4108	>	* @param transformer a function returning the transformation
4109	>	* for an element, or null if there is no transformation (in
4110	>	* which case it is not combined)
4111	>	* @param reducer a commutative associative combining function
4112	>	* @return the result of accumulating the given transformation
4113	>	* of all entries
4114	>	* @since 1.8
4115	>	*/
4116	>	public <U> U reduceEntries(long parallelismThreshold,
4117	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4118	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4119	>	if (transformer == null || reducer == null)
4120	>	throw new NullPointerException();
4121	>	return new MapReduceEntriesTask<K,V,U>
4122	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4123	>	null, transformer, reducer).invoke();
4124	>	}
4125	>
4126	>	/**
4127	>	* Returns the result of accumulating the given transformation
4128	>	* of all entries using the given reducer to combine values,
4129	>	* and the given basis as an identity value.
4130	>	*
4131	>	* @param parallelismThreshold the (estimated) number of elements
4132	>	* needed for this operation to be executed in parallel
4133	>	* @param transformer a function returning the transformation
4134	>	* for an element
4135	>	* @param basis the identity (initial default value) for the reduction
4136	>	* @param reducer a commutative associative combining function
4137	>	* @return the result of accumulating the given transformation
4138	>	* of all entries
4139	>	* @since 1.8
4140	>	*/
4141	>	public double reduceEntriesToDouble(long parallelismThreshold,
4142	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4143	>	double basis,
4144	>	DoubleBinaryOperator reducer) {
4145	>	if (transformer == null || reducer == null)
4146	>	throw new NullPointerException();
4147	>	return new MapReduceEntriesToDoubleTask<K,V>
4148	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4149	>	null, transformer, basis, reducer).invoke();
4150	>	}
4151	>
4152	>	/**
4153	>	* Returns the result of accumulating the given transformation
4154	>	* of all entries using the given reducer to combine values,
4155	>	* and the given basis as an identity value.
4156	>	*
4157	>	* @param parallelismThreshold the (estimated) number of elements
4158	>	* needed for this operation to be executed in parallel
4159	>	* @param transformer a function returning the transformation
4160	>	* for an element
4161	>	* @param basis the identity (initial default value) for the reduction
4162	>	* @param reducer a commutative associative combining function
4163	>	* @return the result of accumulating the given transformation
4164	>	* of all entries
4165	>	* @since 1.8
4166	>	*/
4167	>	public long reduceEntriesToLong(long parallelismThreshold,
4168	>	ToLongFunction<Map.Entry<K,V>> transformer,
4169	>	long basis,
4170	>	LongBinaryOperator reducer) {
4171	>	if (transformer == null || reducer == null)
4172	>	throw new NullPointerException();
4173	>	return new MapReduceEntriesToLongTask<K,V>
4174	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4175	>	null, transformer, basis, reducer).invoke();
4176	>	}
4177	>
4178	>	/**
4179	>	* Returns the result of accumulating the given transformation
4180	>	* of all entries using the given reducer to combine values,
4181	>	* and the given basis as an identity value.
4182	>	*
4183	>	* @param parallelismThreshold the (estimated) number of elements
4184	>	* needed for this operation to be executed in parallel
4185	>	* @param transformer a function returning the transformation
4186	>	* for an element
4187	>	* @param basis the identity (initial default value) for the reduction
4188	>	* @param reducer a commutative associative combining function
4189	>	* @return the result of accumulating the given transformation
4190	>	* of all entries
4191	>	* @since 1.8
4192	>	*/
4193	>	public int reduceEntriesToInt(long parallelismThreshold,
4194	>	ToIntFunction<Map.Entry<K,V>> transformer,
4195	>	int basis,
4196	>	IntBinaryOperator reducer) {
4197	>	if (transformer == null || reducer == null)
4198	>	throw new NullPointerException();
4199	>	return new MapReduceEntriesToIntTask<K,V>
4200	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4201	>	null, transformer, basis, reducer).invoke();
4202	>	}
4203	>
4204	>
4205	>	/* ----------------Views -------------- */
4206	>
4207	>	/**
4208	>	* Base class for views.
4209	>	*/
4210	>	abstract static class CollectionView<K,V,E>
4211	>	implements Collection<E>, java.io.Serializable {
4212	>	private static final long serialVersionUID = 7249069246763182397L;
4213	>	final ConcurrentHashMap<K,V> map;
4214	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4215	>
4216	>	/**
4217	>	* Returns the map backing this view.
4218	>	*
4219	>	* @return the map backing this view
4220	>	*/
4221	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4222	>
4223	>	/**
4224	>	* Removes all of the elements from this view, by removing all
4225	>	* the mappings from the map backing this view.
4226	>	*/
4227	>	public final void clear()      { map.clear(); }
4228	>	public final int size()        { return map.size(); }
4229	>	public final boolean isEmpty() { return map.isEmpty(); }
4230	>
4231	>	// implementations below rely on concrete classes supplying these
4232	>	// abstract methods
4233	>	/**
4234	>	* Returns a "weakly consistent" iterator that will never
4235	>	* throw {@link ConcurrentModificationException}, and
4236	>	* guarantees to traverse elements as they existed upon
4237	>	* construction of the iterator, and may (but is not
4238	>	* guaranteed to) reflect any modifications subsequent to
4239	>	* construction.
4240	>	*/
4241	>	public abstract Iterator<E> iterator();
4242	>	public abstract boolean contains(Object o);
4243	>	public abstract boolean remove(Object o);
4244	>
4245	>	private static final String oomeMsg = "Required array size too large";
4246	>
4247	>	public final Object[] toArray() {
4248	>	long sz = map.mappingCount();
4249	>	if (sz > MAX_ARRAY_SIZE)
4250	>	throw new OutOfMemoryError(oomeMsg);
4251	>	int n = (int)sz;
4252	>	Object[] r = new Object[n];
4253	>	int i = 0;
4254	>	for (E e : this) {
4255	>	if (i == n) {
4256	>	if (n >= MAX_ARRAY_SIZE)
4257	>	throw new OutOfMemoryError(oomeMsg);
4258	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4259	>	n = MAX_ARRAY_SIZE;
4260	>	else
4261	>	n += (n >>> 1) + 1;
4262	>	r = Arrays.copyOf(r, n);
4263	>	}
4264	>	r[i++] = e;
4265	>	}
4266	>	return (i == n) ? r : Arrays.copyOf(r, i);
4267		}
4268	<	public void clear() {
4269	<	ConcurrentHashMap.this.clear();
4268	>
4269	>	@SuppressWarnings("unchecked")
4270	>	public final <T> T[] toArray(T[] a) {
4271	>	long sz = map.mappingCount();
4272	>	if (sz > MAX_ARRAY_SIZE)
4273	>	throw new OutOfMemoryError(oomeMsg);
4274	>	int m = (int)sz;
4275	>	T[] r = (a.length >= m) ? a :
4276	>	(T[])java.lang.reflect.Array
4277	>	.newInstance(a.getClass().getComponentType(), m);
4278	>	int n = r.length;
4279	>	int i = 0;
4280	>	for (E e : this) {
4281	>	if (i == n) {
4282	>	if (n >= MAX_ARRAY_SIZE)
4283	>	throw new OutOfMemoryError(oomeMsg);
4284	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4285	>	n = MAX_ARRAY_SIZE;
4286	>	else
4287	>	n += (n >>> 1) + 1;
4288	>	r = Arrays.copyOf(r, n);
4289	>	}
4290	>	r[i++] = (T)e;
4291	>	}
4292	>	if (a == r && i < n) {
4293	>	r[i] = null; // null-terminate
4294	>	return r;
4295	>	}
4296	>	return (i == n) ? r : Arrays.copyOf(r, i);
4297		}
4298	+
4299	+	/**
4300	+	* Returns a string representation of this collection.
4301	+	* The string representation consists of the string representations
4302	+	* of the collection's elements in the order they are returned by
4303	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4304	+	* Adjacent elements are separated by the characters {@code ", "}
4305	+	* (comma and space).  Elements are converted to strings as by
4306	+	* {@link String#valueOf(Object)}.
4307	+	*
4308	+	* @return a string representation of this collection
4309	+	*/
4310	+	public final String toString() {
4311	+	StringBuilder sb = new StringBuilder();
4312	+	sb.append('[');
4313	+	Iterator<E> it = iterator();
4314	+	if (it.hasNext()) {
4315	+	for (;;) {
4316	+	Object e = it.next();
4317	+	sb.append(e == this ? "(this Collection)" : e);
4318	+	if (!it.hasNext())
4319	+	break;
4320	+	sb.append(',').append(' ');
4321	+	}
4322	+	}
4323	+	return sb.append(']').toString();
4324	+	}
4325	+
4326	+	public final boolean containsAll(Collection<?> c) {
4327	+	if (c != this) {
4328	+	for (Object e : c) {
4329	+	if (e == null || !contains(e))
4330	+	return false;
4331	+	}
4332	+	}
4333	+	return true;
4334	+	}
4335	+
4336	+	public final boolean removeAll(Collection<?> c) {
4337	+	boolean modified = false;
4338	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4339	+	if (c.contains(it.next())) {
4340	+	it.remove();
4341	+	modified = true;
4342	+	}
4343	+	}
4344	+	return modified;
4345	+	}
4346	+
4347	+	public final boolean retainAll(Collection<?> c) {
4348	+	boolean modified = false;
4349	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4350	+	if (!c.contains(it.next())) {
4351	+	it.remove();
4352	+	modified = true;
4353	+	}
4354	+	}
4355	+	return modified;
4356	+	}
4357	+
4358		}
4359
4360	<	final class Values extends AbstractCollection<V> {
4361	<	public Iterator<V> iterator() {
4362	<	return new ValueIterator();
4360	>	/**
4361	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4362	>	* which additions may optionally be enabled by mapping to a
4363	>	* common value.  This class cannot be directly instantiated.
4364	>	* See {@link #keySet() keySet()},
4365	>	* {@link #keySet(Object) keySet(V)},
4366	>	* {@link #newKeySet() newKeySet()},
4367	>	* {@link #newKeySet(int) newKeySet(int)}.
4368	>	*
4369	>	* @since 1.8
4370	>	*/
4371	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4372	>	implements Set<K>, java.io.Serializable {
4373	>	private static final long serialVersionUID = 7249069246763182397L;
4374	>	private final V value;
4375	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4376	>	super(map);
4377	>	this.value = value;
4378		}
4379	<	public int size() {
4380	<	return ConcurrentHashMap.this.size();
4379	>
4380	>	/**
4381	>	* Returns the default mapped value for additions,
4382	>	* or {@code null} if additions are not supported.
4383	>	*
4384	>	* @return the default mapped value for additions, or {@code null}
4385	>	* if not supported
4386	>	*/
4387	>	public V getMappedValue() { return value; }
4388	>
4389	>	/**
4390	>	* {@inheritDoc}
4391	>	* @throws NullPointerException if the specified key is null
4392	>	*/
4393	>	public boolean contains(Object o) { return map.containsKey(o); }
4394	>
4395	>	/**
4396	>	* Removes the key from this map view, by removing the key (and its
4397	>	* corresponding value) from the backing map.  This method does
4398	>	* nothing if the key is not in the map.
4399	>	*
4400	>	* @param  o the key to be removed from the backing map
4401	>	* @return {@code true} if the backing map contained the specified key
4402	>	* @throws NullPointerException if the specified key is null
4403	>	*/
4404	>	public boolean remove(Object o) { return map.remove(o) != null; }
4405	>
4406	>	/**
4407	>	* @return an iterator over the keys of the backing map
4408	>	*/
4409	>	public Iterator<K> iterator() {
4410	>	Node<K,V>[] t;
4411	>	ConcurrentHashMap<K,V> m = map;
4412	>	int f = (t = m.table) == null ? 0 : t.length;
4413	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4414		}
4415	<	public boolean isEmpty() {
4416	<	return ConcurrentHashMap.this.isEmpty();
4415	>
4416	>	/**
4417	>	* Adds the specified key to this set view by mapping the key to
4418	>	* the default mapped value in the backing map, if defined.
4419	>	*
4420	>	* @param e key to be added
4421	>	* @return {@code true} if this set changed as a result of the call
4422	>	* @throws NullPointerException if the specified key is null
4423	>	* @throws UnsupportedOperationException if no default mapped value
4424	>	* for additions was provided
4425	>	*/
4426	>	public boolean add(K e) {
4427	>	V v;
4428	>	if ((v = value) == null)
4429	>	throw new UnsupportedOperationException();
4430	>	return map.putVal(e, v, true) == null;
4431		}
4432	<	public boolean contains(Object o) {
4433	<	return ConcurrentHashMap.this.containsValue(o);
4432	>
4433	>	/**
4434	>	* Adds all of the elements in the specified collection to this set,
4435	>	* as if by calling {@link #add} on each one.
4436	>	*
4437	>	* @param c the elements to be inserted into this set
4438	>	* @return {@code true} if this set changed as a result of the call
4439	>	* @throws NullPointerException if the collection or any of its
4440	>	* elements are {@code null}
4441	>	* @throws UnsupportedOperationException if no default mapped value
4442	>	* for additions was provided
4443	>	*/
4444	>	public boolean addAll(Collection<? extends K> c) {
4445	>	boolean added = false;
4446	>	V v;
4447	>	if ((v = value) == null)
4448	>	throw new UnsupportedOperationException();
4449	>	for (K e : c) {
4450	>	if (map.putVal(e, v, true) == null)
4451	>	added = true;
4452	>	}
4453	>	return added;
4454		}
4455	<	public void clear() {
4456	<	ConcurrentHashMap.this.clear();
4455	>
4456	>	public int hashCode() {
4457	>	int h = 0;
4458	>	for (K e : this)
4459	>	h += e.hashCode();
4460	>	return h;
4461	>	}
4462	>
4463	>	public boolean equals(Object o) {
4464	>	Set<?> c;
4465	>	return ((o instanceof Set) &&
4466	>	((c = (Set<?>)o) == this ||
4467	>	(containsAll(c) && c.containsAll(this))));
4468	>	}
4469	>
4470	>	public Spliterator<K> spliterator() {
4471	>	Node<K,V>[] t;
4472	>	ConcurrentHashMap<K,V> m = map;
4473	>	long n = m.sumCount();
4474	>	int f = (t = m.table) == null ? 0 : t.length;
4475	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4476	>	}
4477	>
4478	>	public void forEach(Consumer<? super K> action) {
4479	>	if (action == null) throw new NullPointerException();
4480	>	Node<K,V>[] t;
4481	>	if ((t = map.table) != null) {
4482	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4483	>	for (Node<K,V> p; (p = it.advance()) != null; )
4484	>	action.accept(p.key);
4485	>	}
4486		}
4487		}
4488
4489	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4490	<	public Iterator<Map.Entry<K,V>> iterator() {
4491	<	return new EntryIterator();
4489	>	/**
4490	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4491	>	* values, in which additions are disabled. This class cannot be
4492	>	* directly instantiated. See {@link #values()}.
4493	>	*/
4494	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4495	>	implements Collection<V>, java.io.Serializable {
4496	>	private static final long serialVersionUID = 2249069246763182397L;
4497	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4498	>	public final boolean contains(Object o) {
4499	>	return map.containsValue(o);
4500	>	}
4501	>
4502	>	public final boolean remove(Object o) {
4503	>	if (o != null) {
4504	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4505	>	if (o.equals(it.next())) {
4506	>	it.remove();
4507	>	return true;
4508	>	}
4509	>	}
4510	>	}
4511	>	return false;
4512	>	}
4513	>
4514	>	public final Iterator<V> iterator() {
4515	>	ConcurrentHashMap<K,V> m = map;
4516	>	Node<K,V>[] t;
4517	>	int f = (t = m.table) == null ? 0 : t.length;
4518	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4519	>	}
4520	>
4521	>	public final boolean add(V e) {
4522	>	throw new UnsupportedOperationException();
4523	>	}
4524	>	public final boolean addAll(Collection<? extends V> c) {
4525	>	throw new UnsupportedOperationException();
4526	>	}
4527	>
4528	>	public Spliterator<V> spliterator() {
4529	>	Node<K,V>[] t;
4530	>	ConcurrentHashMap<K,V> m = map;
4531	>	long n = m.sumCount();
4532	>	int f = (t = m.table) == null ? 0 : t.length;
4533	>	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4534	>	}
4535	>
4536	>	public void forEach(Consumer<? super V> action) {
4537	>	if (action == null) throw new NullPointerException();
4538	>	Node<K,V>[] t;
4539	>	if ((t = map.table) != null) {
4540	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4541	>	for (Node<K,V> p; (p = it.advance()) != null; )
4542	>	action.accept(p.val);
4543	>	}
4544		}
4545	+	}
4546	+
4547	+	/**
4548	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4549	+	* entries.  This class cannot be directly instantiated. See
4550	+	* {@link #entrySet()}.
4551	+	*/
4552	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4553	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4554	+	private static final long serialVersionUID = 2249069246763182397L;
4555	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4556	+
4557		public boolean contains(Object o) {
4558	<	if (!(o instanceof Map.Entry))
4559	<	return false;
4560	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4561	<	V v = ConcurrentHashMap.this.get(e.getKey());
4562	<	return v != null && v.equals(e.getValue());
4558	>	Object k, v, r; Map.Entry<?,?> e;
4559	>	return ((o instanceof Map.Entry) &&
4560	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4561	>	(r = map.get(k)) != null &&
4562	>	(v = e.getValue()) != null &&
4563	>	(v == r || v.equals(r)));
4564		}
4565	+
4566		public boolean remove(Object o) {
4567	<	if (!(o instanceof Map.Entry))
4568	<	return false;
4569	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4570	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4567	>	Object k, v; Map.Entry<?,?> e;
4568	>	return ((o instanceof Map.Entry) &&
4569	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4570	>	(v = e.getValue()) != null &&
4571	>	map.remove(k, v));
4572		}
4573	<	public int size() {
4574	<	return ConcurrentHashMap.this.size();
4573	>
4574	>	/**
4575	>	* @return an iterator over the entries of the backing map
4576	>	*/
4577	>	public Iterator<Map.Entry<K,V>> iterator() {
4578	>	ConcurrentHashMap<K,V> m = map;
4579	>	Node<K,V>[] t;
4580	>	int f = (t = m.table) == null ? 0 : t.length;
4581	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4582	>	}
4583	>
4584	>	public boolean add(Entry<K,V> e) {
4585	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4586	>	}
4587	>
4588	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4589	>	boolean added = false;
4590	>	for (Entry<K,V> e : c) {
4591	>	if (add(e))
4592	>	added = true;
4593	>	}
4594	>	return added;
4595		}
4596	<	public boolean isEmpty() {
4597	<	return ConcurrentHashMap.this.isEmpty();
4596	>
4597	>	public final int hashCode() {
4598	>	int h = 0;
4599	>	Node<K,V>[] t;
4600	>	if ((t = map.table) != null) {
4601	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4602	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
4603	>	h += p.hashCode();
4604	>	}
4605	>	}
4606	>	return h;
4607		}
4608	<	public void clear() {
4609	<	ConcurrentHashMap.this.clear();
4608	>
4609	>	public final boolean equals(Object o) {
4610	>	Set<?> c;
4611	>	return ((o instanceof Set) &&
4612	>	((c = (Set<?>)o) == this ||
4613	>	(containsAll(c) && c.containsAll(this))));
4614	>	}
4615	>
4616	>	public Spliterator<Map.Entry<K,V>> spliterator() {
4617	>	Node<K,V>[] t;
4618	>	ConcurrentHashMap<K,V> m = map;
4619	>	long n = m.sumCount();
4620	>	int f = (t = m.table) == null ? 0 : t.length;
4621	>	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4622	>	}
4623	>
4624	>	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4625	>	if (action == null) throw new NullPointerException();
4626	>	Node<K,V>[] t;
4627	>	if ((t = map.table) != null) {
4628	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4629	>	for (Node<K,V> p; (p = it.advance()) != null; )
4630	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4631	>	}
4632		}
4633	+
4634		}
4635
4636	<	/* ---------------- Serialization Support -------------- */
4636	>	// -------------------------------------------------------
4637
4638		/**
4639	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4640	<	* stream (i.e., serializes it).
1402	<	* @param s the stream
1403	<	* @serialData
1404	<	* the key (Object) and value (Object)
1405	<	* for each key-value mapping, followed by a null pair.
1406	<	* The key-value mappings are emitted in no particular order.
4639	>	* Base class for bulk tasks. Repeats some fields and code from
4640	>	* class Traverser, because we need to subclass CountedCompleter.
4641		*/
4642	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4643	<	// force all segments for serialization compatibility
4644	<	for (int k = 0; k < segments.length; ++k)
4645	<	ensureSegment(k);
4646	<	s.defaultWriteObject();
4647	<
4648	<	final Segment<K,V>[] segments = this.segments;
4649	<	for (int k = 0; k < segments.length; ++k) {
4650	<	Segment<K,V> seg = segmentAt(segments, k);
4651	<	seg.lock();
4652	<	try {
4653	<	HashEntry<K,V>[] tab = seg.table;
4654	<	for (int i = 0; i < tab.length; ++i) {
4655	<	HashEntry<K,V> e;
4656	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4657	<	s.writeObject(e.key);
4658	<	s.writeObject(e.value);
4642	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4643	>	Node<K,V>[] tab;        // same as Traverser
4644	>	Node<K,V> next;
4645	>	int index;
4646	>	int baseIndex;
4647	>	int baseLimit;
4648	>	final int baseSize;
4649	>	int batch;              // split control
4650	>
4651	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4652	>	super(par);
4653	>	this.batch = b;
4654	>	this.index = this.baseIndex = i;
4655	>	if ((this.tab = t) == null)
4656	>	this.baseSize = this.baseLimit = 0;
4657	>	else if (par == null)
4658	>	this.baseSize = this.baseLimit = t.length;
4659	>	else {
4660	>	this.baseLimit = f;
4661	>	this.baseSize = par.baseSize;
4662	>	}
4663	>	}
4664	>
4665	>	/**
4666	>	* Same as Traverser version
4667	>	*/
4668	>	final Node<K,V> advance() {
4669	>	Node<K,V> e;
4670	>	if ((e = next) != null)
4671	>	e = e.next;
4672	>	for (;;) {
4673	>	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4674	>	if (e != null)
4675	>	return next = e;
4676	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4677	>	(n = t.length) <= (i = index) || i < 0)
4678	>	return next = null;
4679	>	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4680	>	if (e instanceof ForwardingNode) {
4681	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4682	>	e = null;
4683	>	continue;
4684		}
4685	+	else if (e instanceof TreeBin)
4686	+	e = ((TreeBin<K,V>)e).first;
4687	+	else
4688	+	e = null;
4689		}
4690	<	} finally {
4691	<	seg.unlock();
4690	>	if ((index += baseSize) >= n)
4691	>	index = ++baseIndex;    // visit upper slots if present
4692		}
4693		}
1431	–	s.writeObject(null);
1432	–	s.writeObject(null);
4694		}
4695
4696	<	/**
4697	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4698	<	* stream (i.e., deserializes it).
4699	<	* @param s the stream
4700	<	*/
4701	<	@SuppressWarnings("unchecked")
4702	<	private void readObject(java.io.ObjectInputStream s)
4703	<	throws IOException, ClassNotFoundException {
4704	<	s.defaultReadObject();
4696	>	/*
4697	>	* Task classes. Coded in a regular but ugly format/style to
4698	>	* simplify checks that each variant differs in the right way from
4699	>	* others. The null screenings exist because compilers cannot tell
4700	>	* that we've already null-checked task arguments, so we force
4701	>	* simplest hoisted bypass to help avoid convoluted traps.
4702	>	*/
4703	>	@SuppressWarnings("serial")
4704	>	static final class ForEachKeyTask<K,V>
4705	>	extends BulkTask<K,V,Void> {
4706	>	final Consumer<? super K> action;
4707	>	ForEachKeyTask
4708	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4709	>	Consumer<? super K> action) {
4710	>	super(p, b, i, f, t);
4711	>	this.action = action;
4712	>	}
4713	>	public final void compute() {
4714	>	final Consumer<? super K> action;
4715	>	if ((action = this.action) != null) {
4716	>	for (int i = baseIndex, f, h; batch > 0 &&
4717	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4718	>	addToPendingCount(1);
4719	>	new ForEachKeyTask<K,V>
4720	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4721	>	action).fork();
4722	>	}
4723	>	for (Node<K,V> p; (p = advance()) != null;)
4724	>	action.accept(p.key);
4725	>	propagateCompletion();
4726	>	}
4727	>	}
4728	>	}
4729
4730	<	// Re-initialize segments to be minimally sized, and let grow.
4731	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4732	<	final Segment<K,V>[] segments = this.segments;
4733	<	for (int k = 0; k < segments.length; ++k) {
4734	<	Segment<K,V> seg = segments[k];
4735	<	if (seg != null) {
4736	<	seg.threshold = (int)(cap * seg.loadFactor);
4737	<	seg.table = (HashEntry<K,V>[]) new HashEntry[cap];
4730	>	@SuppressWarnings("serial")
4731	>	static final class ForEachValueTask<K,V>
4732	>	extends BulkTask<K,V,Void> {
4733	>	final Consumer<? super V> action;
4734	>	ForEachValueTask
4735	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4736	>	Consumer<? super V> action) {
4737	>	super(p, b, i, f, t);
4738	>	this.action = action;
4739	>	}
4740	>	public final void compute() {
4741	>	final Consumer<? super V> action;
4742	>	if ((action = this.action) != null) {
4743	>	for (int i = baseIndex, f, h; batch > 0 &&
4744	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4745	>	addToPendingCount(1);
4746	>	new ForEachValueTask<K,V>
4747	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4748	>	action).fork();
4749	>	}
4750	>	for (Node<K,V> p; (p = advance()) != null;)
4751	>	action.accept(p.val);
4752	>	propagateCompletion();
4753		}
4754		}
4755	+	}
4756
4757	<	// Read the keys and values, and put the mappings in the table
4758	<	for (;;) {
4759	<	K key = (K) s.readObject();
4760	<	V value = (V) s.readObject();
4761	<	if (key == null)
4762	<	break;
4763	<	put(key, value);
4757	>	@SuppressWarnings("serial")
4758	>	static final class ForEachEntryTask<K,V>
4759	>	extends BulkTask<K,V,Void> {
4760	>	final Consumer<? super Entry<K,V>> action;
4761	>	ForEachEntryTask
4762	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4763	>	Consumer<? super Entry<K,V>> action) {
4764	>	super(p, b, i, f, t);
4765	>	this.action = action;
4766	>	}
4767	>	public final void compute() {
4768	>	final Consumer<? super Entry<K,V>> action;
4769	>	if ((action = this.action) != null) {
4770	>	for (int i = baseIndex, f, h; batch > 0 &&
4771	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4772	>	addToPendingCount(1);
4773	>	new ForEachEntryTask<K,V>
4774	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4775	>	action).fork();
4776	>	}
4777	>	for (Node<K,V> p; (p = advance()) != null; )
4778	>	action.accept(p);
4779	>	propagateCompletion();
4780	>	}
4781	>	}
4782	>	}
4783	>
4784	>	@SuppressWarnings("serial")
4785	>	static final class ForEachMappingTask<K,V>
4786	>	extends BulkTask<K,V,Void> {
4787	>	final BiConsumer<? super K, ? super V> action;
4788	>	ForEachMappingTask
4789	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4790	>	BiConsumer<? super K,? super V> action) {
4791	>	super(p, b, i, f, t);
4792	>	this.action = action;
4793	>	}
4794	>	public final void compute() {
4795	>	final BiConsumer<? super K, ? super V> action;
4796	>	if ((action = this.action) != null) {
4797	>	for (int i = baseIndex, f, h; batch > 0 &&
4798	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4799	>	addToPendingCount(1);
4800	>	new ForEachMappingTask<K,V>
4801	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4802	>	action).fork();
4803	>	}
4804	>	for (Node<K,V> p; (p = advance()) != null; )
4805	>	action.accept(p.key, p.val);
4806	>	propagateCompletion();
4807	>	}
4808	>	}
4809	>	}
4810	>
4811	>	@SuppressWarnings("serial")
4812	>	static final class ForEachTransformedKeyTask<K,V,U>
4813	>	extends BulkTask<K,V,Void> {
4814	>	final Function<? super K, ? extends U> transformer;
4815	>	final Consumer<? super U> action;
4816	>	ForEachTransformedKeyTask
4817	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4818	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4819	>	super(p, b, i, f, t);
4820	>	this.transformer = transformer; this.action = action;
4821	>	}
4822	>	public final void compute() {
4823	>	final Function<? super K, ? extends U> transformer;
4824	>	final Consumer<? super U> action;
4825	>	if ((transformer = this.transformer) != null &&
4826	>	(action = this.action) != null) {
4827	>	for (int i = baseIndex, f, h; batch > 0 &&
4828	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4829	>	addToPendingCount(1);
4830	>	new ForEachTransformedKeyTask<K,V,U>
4831	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4832	>	transformer, action).fork();
4833	>	}
4834	>	for (Node<K,V> p; (p = advance()) != null; ) {
4835	>	U u;
4836	>	if ((u = transformer.apply(p.key)) != null)
4837	>	action.accept(u);
4838	>	}
4839	>	propagateCompletion();
4840	>	}
4841	>	}
4842	>	}
4843	>
4844	>	@SuppressWarnings("serial")
4845	>	static final class ForEachTransformedValueTask<K,V,U>
4846	>	extends BulkTask<K,V,Void> {
4847	>	final Function<? super V, ? extends U> transformer;
4848	>	final Consumer<? super U> action;
4849	>	ForEachTransformedValueTask
4850	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4851	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
4852	>	super(p, b, i, f, t);
4853	>	this.transformer = transformer; this.action = action;
4854	>	}
4855	>	public final void compute() {
4856	>	final Function<? super V, ? extends U> transformer;
4857	>	final Consumer<? super U> action;
4858	>	if ((transformer = this.transformer) != null &&
4859	>	(action = this.action) != null) {
4860	>	for (int i = baseIndex, f, h; batch > 0 &&
4861	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4862	>	addToPendingCount(1);
4863	>	new ForEachTransformedValueTask<K,V,U>
4864	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4865	>	transformer, action).fork();
4866	>	}
4867	>	for (Node<K,V> p; (p = advance()) != null; ) {
4868	>	U u;
4869	>	if ((u = transformer.apply(p.val)) != null)
4870	>	action.accept(u);
4871	>	}
4872	>	propagateCompletion();
4873	>	}
4874	>	}
4875	>	}
4876	>
4877	>	@SuppressWarnings("serial")
4878	>	static final class ForEachTransformedEntryTask<K,V,U>
4879	>	extends BulkTask<K,V,Void> {
4880	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4881	>	final Consumer<? super U> action;
4882	>	ForEachTransformedEntryTask
4883	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4884	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
4885	>	super(p, b, i, f, t);
4886	>	this.transformer = transformer; this.action = action;
4887	>	}
4888	>	public final void compute() {
4889	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
4890	>	final Consumer<? super U> action;
4891	>	if ((transformer = this.transformer) != null &&
4892	>	(action = this.action) != null) {
4893	>	for (int i = baseIndex, f, h; batch > 0 &&
4894	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4895	>	addToPendingCount(1);
4896	>	new ForEachTransformedEntryTask<K,V,U>
4897	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4898	>	transformer, action).fork();
4899	>	}
4900	>	for (Node<K,V> p; (p = advance()) != null; ) {
4901	>	U u;
4902	>	if ((u = transformer.apply(p)) != null)
4903	>	action.accept(u);
4904	>	}
4905	>	propagateCompletion();
4906	>	}
4907	>	}
4908	>	}
4909	>
4910	>	@SuppressWarnings("serial")
4911	>	static final class ForEachTransformedMappingTask<K,V,U>
4912	>	extends BulkTask<K,V,Void> {
4913	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4914	>	final Consumer<? super U> action;
4915	>	ForEachTransformedMappingTask
4916	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4917	>	BiFunction<? super K, ? super V, ? extends U> transformer,
4918	>	Consumer<? super U> action) {
4919	>	super(p, b, i, f, t);
4920	>	this.transformer = transformer; this.action = action;
4921	>	}
4922	>	public final void compute() {
4923	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
4924	>	final Consumer<? super U> action;
4925	>	if ((transformer = this.transformer) != null &&
4926	>	(action = this.action) != null) {
4927	>	for (int i = baseIndex, f, h; batch > 0 &&
4928	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4929	>	addToPendingCount(1);
4930	>	new ForEachTransformedMappingTask<K,V,U>
4931	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4932	>	transformer, action).fork();
4933	>	}
4934	>	for (Node<K,V> p; (p = advance()) != null; ) {
4935	>	U u;
4936	>	if ((u = transformer.apply(p.key, p.val)) != null)
4937	>	action.accept(u);
4938	>	}
4939	>	propagateCompletion();
4940	>	}
4941	>	}
4942	>	}
4943	>
4944	>	@SuppressWarnings("serial")
4945	>	static final class SearchKeysTask<K,V,U>
4946	>	extends BulkTask<K,V,U> {
4947	>	final Function<? super K, ? extends U> searchFunction;
4948	>	final AtomicReference<U> result;
4949	>	SearchKeysTask
4950	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4951	>	Function<? super K, ? extends U> searchFunction,
4952	>	AtomicReference<U> result) {
4953	>	super(p, b, i, f, t);
4954	>	this.searchFunction = searchFunction; this.result = result;
4955	>	}
4956	>	public final U getRawResult() { return result.get(); }
4957	>	public final void compute() {
4958	>	final Function<? super K, ? extends U> searchFunction;
4959	>	final AtomicReference<U> result;
4960	>	if ((searchFunction = this.searchFunction) != null &&
4961	>	(result = this.result) != null) {
4962	>	for (int i = baseIndex, f, h; batch > 0 &&
4963	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4964	>	if (result.get() != null)
4965	>	return;
4966	>	addToPendingCount(1);
4967	>	new SearchKeysTask<K,V,U>
4968	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4969	>	searchFunction, result).fork();
4970	>	}
4971	>	while (result.get() == null) {
4972	>	U u;
4973	>	Node<K,V> p;
4974	>	if ((p = advance()) == null) {
4975	>	propagateCompletion();
4976	>	break;
4977	>	}
4978	>	if ((u = searchFunction.apply(p.key)) != null) {
4979	>	if (result.compareAndSet(null, u))
4980	>	quietlyCompleteRoot();
4981	>	break;
4982	>	}
4983	>	}
4984	>	}
4985	>	}
4986	>	}
4987	>
4988	>	@SuppressWarnings("serial")
4989	>	static final class SearchValuesTask<K,V,U>
4990	>	extends BulkTask<K,V,U> {
4991	>	final Function<? super V, ? extends U> searchFunction;
4992	>	final AtomicReference<U> result;
4993	>	SearchValuesTask
4994	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4995	>	Function<? super V, ? extends U> searchFunction,
4996	>	AtomicReference<U> result) {
4997	>	super(p, b, i, f, t);
4998	>	this.searchFunction = searchFunction; this.result = result;
4999	>	}
5000	>	public final U getRawResult() { return result.get(); }
5001	>	public final void compute() {
5002	>	final Function<? super V, ? extends U> searchFunction;
5003	>	final AtomicReference<U> result;
5004	>	if ((searchFunction = this.searchFunction) != null &&
5005	>	(result = this.result) != null) {
5006	>	for (int i = baseIndex, f, h; batch > 0 &&
5007	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5008	>	if (result.get() != null)
5009	>	return;
5010	>	addToPendingCount(1);
5011	>	new SearchValuesTask<K,V,U>
5012	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5013	>	searchFunction, result).fork();
5014	>	}
5015	>	while (result.get() == null) {
5016	>	U u;
5017	>	Node<K,V> p;
5018	>	if ((p = advance()) == null) {
5019	>	propagateCompletion();
5020	>	break;
5021	>	}
5022	>	if ((u = searchFunction.apply(p.val)) != null) {
5023	>	if (result.compareAndSet(null, u))
5024	>	quietlyCompleteRoot();
5025	>	break;
5026	>	}
5027	>	}
5028	>	}
5029	>	}
5030	>	}
5031	>
5032	>	@SuppressWarnings("serial")
5033	>	static final class SearchEntriesTask<K,V,U>
5034	>	extends BulkTask<K,V,U> {
5035	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5036	>	final AtomicReference<U> result;
5037	>	SearchEntriesTask
5038	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5039	>	Function<Entry<K,V>, ? extends U> searchFunction,
5040	>	AtomicReference<U> result) {
5041	>	super(p, b, i, f, t);
5042	>	this.searchFunction = searchFunction; this.result = result;
5043	>	}
5044	>	public final U getRawResult() { return result.get(); }
5045	>	public final void compute() {
5046	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5047	>	final AtomicReference<U> result;
5048	>	if ((searchFunction = this.searchFunction) != null &&
5049	>	(result = this.result) != null) {
5050	>	for (int i = baseIndex, f, h; batch > 0 &&
5051	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5052	>	if (result.get() != null)
5053	>	return;
5054	>	addToPendingCount(1);
5055	>	new SearchEntriesTask<K,V,U>
5056	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5057	>	searchFunction, result).fork();
5058	>	}
5059	>	while (result.get() == null) {
5060	>	U u;
5061	>	Node<K,V> p;
5062	>	if ((p = advance()) == null) {
5063	>	propagateCompletion();
5064	>	break;
5065	>	}
5066	>	if ((u = searchFunction.apply(p)) != null) {
5067	>	if (result.compareAndSet(null, u))
5068	>	quietlyCompleteRoot();
5069	>	return;
5070	>	}
5071	>	}
5072	>	}
5073	>	}
5074	>	}
5075	>
5076	>	@SuppressWarnings("serial")
5077	>	static final class SearchMappingsTask<K,V,U>
5078	>	extends BulkTask<K,V,U> {
5079	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5080	>	final AtomicReference<U> result;
5081	>	SearchMappingsTask
5082	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5083	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5084	>	AtomicReference<U> result) {
5085	>	super(p, b, i, f, t);
5086	>	this.searchFunction = searchFunction; this.result = result;
5087	>	}
5088	>	public final U getRawResult() { return result.get(); }
5089	>	public final void compute() {
5090	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5091	>	final AtomicReference<U> result;
5092	>	if ((searchFunction = this.searchFunction) != null &&
5093	>	(result = this.result) != null) {
5094	>	for (int i = baseIndex, f, h; batch > 0 &&
5095	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5096	>	if (result.get() != null)
5097	>	return;
5098	>	addToPendingCount(1);
5099	>	new SearchMappingsTask<K,V,U>
5100	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5101	>	searchFunction, result).fork();
5102	>	}
5103	>	while (result.get() == null) {
5104	>	U u;
5105	>	Node<K,V> p;
5106	>	if ((p = advance()) == null) {
5107	>	propagateCompletion();
5108	>	break;
5109	>	}
5110	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5111	>	if (result.compareAndSet(null, u))
5112	>	quietlyCompleteRoot();
5113	>	break;
5114	>	}
5115	>	}
5116	>	}
5117	>	}
5118	>	}
5119	>
5120	>	@SuppressWarnings("serial")
5121	>	static final class ReduceKeysTask<K,V>
5122	>	extends BulkTask<K,V,K> {
5123	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5124	>	K result;
5125	>	ReduceKeysTask<K,V> rights, nextRight;
5126	>	ReduceKeysTask
5127	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5128	>	ReduceKeysTask<K,V> nextRight,
5129	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5130	>	super(p, b, i, f, t); this.nextRight = nextRight;
5131	>	this.reducer = reducer;
5132	>	}
5133	>	public final K getRawResult() { return result; }
5134	>	public final void compute() {
5135	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5136	>	if ((reducer = this.reducer) != null) {
5137	>	for (int i = baseIndex, f, h; batch > 0 &&
5138	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5139	>	addToPendingCount(1);
5140	>	(rights = new ReduceKeysTask<K,V>
5141	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5142	>	rights, reducer)).fork();
5143	>	}
5144	>	K r = null;
5145	>	for (Node<K,V> p; (p = advance()) != null; ) {
5146	>	K u = p.key;
5147	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5148	>	}
5149	>	result = r;
5150	>	CountedCompleter<?> c;
5151	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5152	>	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5153	>	t = (ReduceKeysTask<K,V>)c,
5154	>	s = t.rights;
5155	>	while (s != null) {
5156	>	K tr, sr;
5157	>	if ((sr = s.result) != null)
5158	>	t.result = (((tr = t.result) == null) ? sr :
5159	>	reducer.apply(tr, sr));
5160	>	s = t.rights = s.nextRight;
5161	>	}
5162	>	}
5163	>	}
5164	>	}
5165	>	}
5166	>
5167	>	@SuppressWarnings("serial")
5168	>	static final class ReduceValuesTask<K,V>
5169	>	extends BulkTask<K,V,V> {
5170	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5171	>	V result;
5172	>	ReduceValuesTask<K,V> rights, nextRight;
5173	>	ReduceValuesTask
5174	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5175	>	ReduceValuesTask<K,V> nextRight,
5176	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5177	>	super(p, b, i, f, t); this.nextRight = nextRight;
5178	>	this.reducer = reducer;
5179	>	}
5180	>	public final V getRawResult() { return result; }
5181	>	public final void compute() {
5182	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5183	>	if ((reducer = this.reducer) != null) {
5184	>	for (int i = baseIndex, f, h; batch > 0 &&
5185	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5186	>	addToPendingCount(1);
5187	>	(rights = new ReduceValuesTask<K,V>
5188	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5189	>	rights, reducer)).fork();
5190	>	}
5191	>	V r = null;
5192	>	for (Node<K,V> p; (p = advance()) != null; ) {
5193	>	V v = p.val;
5194	>	r = (r == null) ? v : reducer.apply(r, v);
5195	>	}
5196	>	result = r;
5197	>	CountedCompleter<?> c;
5198	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5199	>	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5200	>	t = (ReduceValuesTask<K,V>)c,
5201	>	s = t.rights;
5202	>	while (s != null) {
5203	>	V tr, sr;
5204	>	if ((sr = s.result) != null)
5205	>	t.result = (((tr = t.result) == null) ? sr :
5206	>	reducer.apply(tr, sr));
5207	>	s = t.rights = s.nextRight;
5208	>	}
5209	>	}
5210	>	}
5211	>	}
5212	>	}
5213	>
5214	>	@SuppressWarnings("serial")
5215	>	static final class ReduceEntriesTask<K,V>
5216	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5217	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5218	>	Map.Entry<K,V> result;
5219	>	ReduceEntriesTask<K,V> rights, nextRight;
5220	>	ReduceEntriesTask
5221	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5222	>	ReduceEntriesTask<K,V> nextRight,
5223	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5224	>	super(p, b, i, f, t); this.nextRight = nextRight;
5225	>	this.reducer = reducer;
5226	>	}
5227	>	public final Map.Entry<K,V> getRawResult() { return result; }
5228	>	public final void compute() {
5229	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5230	>	if ((reducer = this.reducer) != null) {
5231	>	for (int i = baseIndex, f, h; batch > 0 &&
5232	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5233	>	addToPendingCount(1);
5234	>	(rights = new ReduceEntriesTask<K,V>
5235	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5236	>	rights, reducer)).fork();
5237	>	}
5238	>	Map.Entry<K,V> r = null;
5239	>	for (Node<K,V> p; (p = advance()) != null; )
5240	>	r = (r == null) ? p : reducer.apply(r, p);
5241	>	result = r;
5242	>	CountedCompleter<?> c;
5243	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5244	>	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5245	>	t = (ReduceEntriesTask<K,V>)c,
5246	>	s = t.rights;
5247	>	while (s != null) {
5248	>	Map.Entry<K,V> tr, sr;
5249	>	if ((sr = s.result) != null)
5250	>	t.result = (((tr = t.result) == null) ? sr :
5251	>	reducer.apply(tr, sr));
5252	>	s = t.rights = s.nextRight;
5253	>	}
5254	>	}
5255	>	}
5256	>	}
5257	>	}
5258	>
5259	>	@SuppressWarnings("serial")
5260	>	static final class MapReduceKeysTask<K,V,U>
5261	>	extends BulkTask<K,V,U> {
5262	>	final Function<? super K, ? extends U> transformer;
5263	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5264	>	U result;
5265	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5266	>	MapReduceKeysTask
5267	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5268	>	MapReduceKeysTask<K,V,U> nextRight,
5269	>	Function<? super K, ? extends U> transformer,
5270	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5271	>	super(p, b, i, f, t); this.nextRight = nextRight;
5272	>	this.transformer = transformer;
5273	>	this.reducer = reducer;
5274	>	}
5275	>	public final U getRawResult() { return result; }
5276	>	public final void compute() {
5277	>	final Function<? super K, ? extends U> transformer;
5278	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5279	>	if ((transformer = this.transformer) != null &&
5280	>	(reducer = this.reducer) != null) {
5281	>	for (int i = baseIndex, f, h; batch > 0 &&
5282	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5283	>	addToPendingCount(1);
5284	>	(rights = new MapReduceKeysTask<K,V,U>
5285	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5286	>	rights, transformer, reducer)).fork();
5287	>	}
5288	>	U r = null;
5289	>	for (Node<K,V> p; (p = advance()) != null; ) {
5290	>	U u;
5291	>	if ((u = transformer.apply(p.key)) != null)
5292	>	r = (r == null) ? u : reducer.apply(r, u);
5293	>	}
5294	>	result = r;
5295	>	CountedCompleter<?> c;
5296	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5297	>	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5298	>	t = (MapReduceKeysTask<K,V,U>)c,
5299	>	s = t.rights;
5300	>	while (s != null) {
5301	>	U tr, sr;
5302	>	if ((sr = s.result) != null)
5303	>	t.result = (((tr = t.result) == null) ? sr :
5304	>	reducer.apply(tr, sr));
5305	>	s = t.rights = s.nextRight;
5306	>	}
5307	>	}
5308	>	}
5309	>	}
5310	>	}
5311	>
5312	>	@SuppressWarnings("serial")
5313	>	static final class MapReduceValuesTask<K,V,U>
5314	>	extends BulkTask<K,V,U> {
5315	>	final Function<? super V, ? extends U> transformer;
5316	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5317	>	U result;
5318	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5319	>	MapReduceValuesTask
5320	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5321	>	MapReduceValuesTask<K,V,U> nextRight,
5322	>	Function<? super V, ? extends U> transformer,
5323	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5324	>	super(p, b, i, f, t); this.nextRight = nextRight;
5325	>	this.transformer = transformer;
5326	>	this.reducer = reducer;
5327	>	}
5328	>	public final U getRawResult() { return result; }
5329	>	public final void compute() {
5330	>	final Function<? super V, ? extends U> transformer;
5331	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5332	>	if ((transformer = this.transformer) != null &&
5333	>	(reducer = this.reducer) != null) {
5334	>	for (int i = baseIndex, f, h; batch > 0 &&
5335	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5336	>	addToPendingCount(1);
5337	>	(rights = new MapReduceValuesTask<K,V,U>
5338	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5339	>	rights, transformer, reducer)).fork();
5340	>	}
5341	>	U r = null;
5342	>	for (Node<K,V> p; (p = advance()) != null; ) {
5343	>	U u;
5344	>	if ((u = transformer.apply(p.val)) != null)
5345	>	r = (r == null) ? u : reducer.apply(r, u);
5346	>	}
5347	>	result = r;
5348	>	CountedCompleter<?> c;
5349	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5350	>	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5351	>	t = (MapReduceValuesTask<K,V,U>)c,
5352	>	s = t.rights;
5353	>	while (s != null) {
5354	>	U tr, sr;
5355	>	if ((sr = s.result) != null)
5356	>	t.result = (((tr = t.result) == null) ? sr :
5357	>	reducer.apply(tr, sr));
5358	>	s = t.rights = s.nextRight;
5359	>	}
5360	>	}
5361	>	}
5362	>	}
5363	>	}
5364	>
5365	>	@SuppressWarnings("serial")
5366	>	static final class MapReduceEntriesTask<K,V,U>
5367	>	extends BulkTask<K,V,U> {
5368	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5369	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5370	>	U result;
5371	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5372	>	MapReduceEntriesTask
5373	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5374	>	MapReduceEntriesTask<K,V,U> nextRight,
5375	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5376	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5377	>	super(p, b, i, f, t); this.nextRight = nextRight;
5378	>	this.transformer = transformer;
5379	>	this.reducer = reducer;
5380	>	}
5381	>	public final U getRawResult() { return result; }
5382	>	public final void compute() {
5383	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5384	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5385	>	if ((transformer = this.transformer) != null &&
5386	>	(reducer = this.reducer) != null) {
5387	>	for (int i = baseIndex, f, h; batch > 0 &&
5388	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5389	>	addToPendingCount(1);
5390	>	(rights = new MapReduceEntriesTask<K,V,U>
5391	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5392	>	rights, transformer, reducer)).fork();
5393	>	}
5394	>	U r = null;
5395	>	for (Node<K,V> p; (p = advance()) != null; ) {
5396	>	U u;
5397	>	if ((u = transformer.apply(p)) != null)
5398	>	r = (r == null) ? u : reducer.apply(r, u);
5399	>	}
5400	>	result = r;
5401	>	CountedCompleter<?> c;
5402	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5403	>	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5404	>	t = (MapReduceEntriesTask<K,V,U>)c,
5405	>	s = t.rights;
5406	>	while (s != null) {
5407	>	U tr, sr;
5408	>	if ((sr = s.result) != null)
5409	>	t.result = (((tr = t.result) == null) ? sr :
5410	>	reducer.apply(tr, sr));
5411	>	s = t.rights = s.nextRight;
5412	>	}
5413	>	}
5414	>	}
5415	>	}
5416	>	}
5417	>
5418	>	@SuppressWarnings("serial")
5419	>	static final class MapReduceMappingsTask<K,V,U>
5420	>	extends BulkTask<K,V,U> {
5421	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5422	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5423	>	U result;
5424	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5425	>	MapReduceMappingsTask
5426	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5427	>	MapReduceMappingsTask<K,V,U> nextRight,
5428	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5429	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5430	>	super(p, b, i, f, t); this.nextRight = nextRight;
5431	>	this.transformer = transformer;
5432	>	this.reducer = reducer;
5433	>	}
5434	>	public final U getRawResult() { return result; }
5435	>	public final void compute() {
5436	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5437	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5438	>	if ((transformer = this.transformer) != null &&
5439	>	(reducer = this.reducer) != null) {
5440	>	for (int i = baseIndex, f, h; batch > 0 &&
5441	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5442	>	addToPendingCount(1);
5443	>	(rights = new MapReduceMappingsTask<K,V,U>
5444	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5445	>	rights, transformer, reducer)).fork();
5446	>	}
5447	>	U r = null;
5448	>	for (Node<K,V> p; (p = advance()) != null; ) {
5449	>	U u;
5450	>	if ((u = transformer.apply(p.key, p.val)) != null)
5451	>	r = (r == null) ? u : reducer.apply(r, u);
5452	>	}
5453	>	result = r;
5454	>	CountedCompleter<?> c;
5455	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5456	>	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5457	>	t = (MapReduceMappingsTask<K,V,U>)c,
5458	>	s = t.rights;
5459	>	while (s != null) {
5460	>	U tr, sr;
5461	>	if ((sr = s.result) != null)
5462	>	t.result = (((tr = t.result) == null) ? sr :
5463	>	reducer.apply(tr, sr));
5464	>	s = t.rights = s.nextRight;
5465	>	}
5466	>	}
5467	>	}
5468	>	}
5469	>	}
5470	>
5471	>	@SuppressWarnings("serial")
5472	>	static final class MapReduceKeysToDoubleTask<K,V>
5473	>	extends BulkTask<K,V,Double> {
5474	>	final ToDoubleFunction<? super K> transformer;
5475	>	final DoubleBinaryOperator reducer;
5476	>	final double basis;
5477	>	double result;
5478	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5479	>	MapReduceKeysToDoubleTask
5480	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5481	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5482	>	ToDoubleFunction<? super K> transformer,
5483	>	double basis,
5484	>	DoubleBinaryOperator reducer) {
5485	>	super(p, b, i, f, t); this.nextRight = nextRight;
5486	>	this.transformer = transformer;
5487	>	this.basis = basis; this.reducer = reducer;
5488	>	}
5489	>	public final Double getRawResult() { return result; }
5490	>	public final void compute() {
5491	>	final ToDoubleFunction<? super K> transformer;
5492	>	final DoubleBinaryOperator reducer;
5493	>	if ((transformer = this.transformer) != null &&
5494	>	(reducer = this.reducer) != null) {
5495	>	double r = this.basis;
5496	>	for (int i = baseIndex, f, h; batch > 0 &&
5497	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5498	>	addToPendingCount(1);
5499	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5500	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5501	>	rights, transformer, r, reducer)).fork();
5502	>	}
5503	>	for (Node<K,V> p; (p = advance()) != null; )
5504	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5505	>	result = r;
5506	>	CountedCompleter<?> c;
5507	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5508	>	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5509	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5510	>	s = t.rights;
5511	>	while (s != null) {
5512	>	t.result = reducer.applyAsDouble(t.result, s.result);
5513	>	s = t.rights = s.nextRight;
5514	>	}
5515	>	}
5516	>	}
5517	>	}
5518	>	}
5519	>
5520	>	@SuppressWarnings("serial")
5521	>	static final class MapReduceValuesToDoubleTask<K,V>
5522	>	extends BulkTask<K,V,Double> {
5523	>	final ToDoubleFunction<? super V> transformer;
5524	>	final DoubleBinaryOperator reducer;
5525	>	final double basis;
5526	>	double result;
5527	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5528	>	MapReduceValuesToDoubleTask
5529	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5530	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5531	>	ToDoubleFunction<? super V> transformer,
5532	>	double basis,
5533	>	DoubleBinaryOperator reducer) {
5534	>	super(p, b, i, f, t); this.nextRight = nextRight;
5535	>	this.transformer = transformer;
5536	>	this.basis = basis; this.reducer = reducer;
5537	>	}
5538	>	public final Double getRawResult() { return result; }
5539	>	public final void compute() {
5540	>	final ToDoubleFunction<? super V> transformer;
5541	>	final DoubleBinaryOperator reducer;
5542	>	if ((transformer = this.transformer) != null &&
5543	>	(reducer = this.reducer) != null) {
5544	>	double r = this.basis;
5545	>	for (int i = baseIndex, f, h; batch > 0 &&
5546	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5547	>	addToPendingCount(1);
5548	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5549	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5550	>	rights, transformer, r, reducer)).fork();
5551	>	}
5552	>	for (Node<K,V> p; (p = advance()) != null; )
5553	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5554	>	result = r;
5555	>	CountedCompleter<?> c;
5556	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5557	>	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5558	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5559	>	s = t.rights;
5560	>	while (s != null) {
5561	>	t.result = reducer.applyAsDouble(t.result, s.result);
5562	>	s = t.rights = s.nextRight;
5563	>	}
5564	>	}
5565	>	}
5566	>	}
5567	>	}
5568	>
5569	>	@SuppressWarnings("serial")
5570	>	static final class MapReduceEntriesToDoubleTask<K,V>
5571	>	extends BulkTask<K,V,Double> {
5572	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5573	>	final DoubleBinaryOperator reducer;
5574	>	final double basis;
5575	>	double result;
5576	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5577	>	MapReduceEntriesToDoubleTask
5578	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5579	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5580	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5581	>	double basis,
5582	>	DoubleBinaryOperator reducer) {
5583	>	super(p, b, i, f, t); this.nextRight = nextRight;
5584	>	this.transformer = transformer;
5585	>	this.basis = basis; this.reducer = reducer;
5586	>	}
5587	>	public final Double getRawResult() { return result; }
5588	>	public final void compute() {
5589	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5590	>	final DoubleBinaryOperator reducer;
5591	>	if ((transformer = this.transformer) != null &&
5592	>	(reducer = this.reducer) != null) {
5593	>	double r = this.basis;
5594	>	for (int i = baseIndex, f, h; batch > 0 &&
5595	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5596	>	addToPendingCount(1);
5597	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5598	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5599	>	rights, transformer, r, reducer)).fork();
5600	>	}
5601	>	for (Node<K,V> p; (p = advance()) != null; )
5602	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5603	>	result = r;
5604	>	CountedCompleter<?> c;
5605	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5606	>	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5607	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5608	>	s = t.rights;
5609	>	while (s != null) {
5610	>	t.result = reducer.applyAsDouble(t.result, s.result);
5611	>	s = t.rights = s.nextRight;
5612	>	}
5613	>	}
5614	>	}
5615	>	}
5616	>	}
5617	>
5618	>	@SuppressWarnings("serial")
5619	>	static final class MapReduceMappingsToDoubleTask<K,V>
5620	>	extends BulkTask<K,V,Double> {
5621	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5622	>	final DoubleBinaryOperator reducer;
5623	>	final double basis;
5624	>	double result;
5625	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5626	>	MapReduceMappingsToDoubleTask
5627	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5628	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5629	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5630	>	double basis,
5631	>	DoubleBinaryOperator reducer) {
5632	>	super(p, b, i, f, t); this.nextRight = nextRight;
5633	>	this.transformer = transformer;
5634	>	this.basis = basis; this.reducer = reducer;
5635	>	}
5636	>	public final Double getRawResult() { return result; }
5637	>	public final void compute() {
5638	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5639	>	final DoubleBinaryOperator reducer;
5640	>	if ((transformer = this.transformer) != null &&
5641	>	(reducer = this.reducer) != null) {
5642	>	double r = this.basis;
5643	>	for (int i = baseIndex, f, h; batch > 0 &&
5644	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5645	>	addToPendingCount(1);
5646	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5647	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5648	>	rights, transformer, r, reducer)).fork();
5649	>	}
5650	>	for (Node<K,V> p; (p = advance()) != null; )
5651	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5652	>	result = r;
5653	>	CountedCompleter<?> c;
5654	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5655	>	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5656	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5657	>	s = t.rights;
5658	>	while (s != null) {
5659	>	t.result = reducer.applyAsDouble(t.result, s.result);
5660	>	s = t.rights = s.nextRight;
5661	>	}
5662	>	}
5663	>	}
5664	>	}
5665	>	}
5666	>
5667	>	@SuppressWarnings("serial")
5668	>	static final class MapReduceKeysToLongTask<K,V>
5669	>	extends BulkTask<K,V,Long> {
5670	>	final ToLongFunction<? super K> transformer;
5671	>	final LongBinaryOperator reducer;
5672	>	final long basis;
5673	>	long result;
5674	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5675	>	MapReduceKeysToLongTask
5676	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5677	>	MapReduceKeysToLongTask<K,V> nextRight,
5678	>	ToLongFunction<? super K> transformer,
5679	>	long basis,
5680	>	LongBinaryOperator reducer) {
5681	>	super(p, b, i, f, t); this.nextRight = nextRight;
5682	>	this.transformer = transformer;
5683	>	this.basis = basis; this.reducer = reducer;
5684	>	}
5685	>	public final Long getRawResult() { return result; }
5686	>	public final void compute() {
5687	>	final ToLongFunction<? super K> transformer;
5688	>	final LongBinaryOperator reducer;
5689	>	if ((transformer = this.transformer) != null &&
5690	>	(reducer = this.reducer) != null) {
5691	>	long r = this.basis;
5692	>	for (int i = baseIndex, f, h; batch > 0 &&
5693	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5694	>	addToPendingCount(1);
5695	>	(rights = new MapReduceKeysToLongTask<K,V>
5696	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5697	>	rights, transformer, r, reducer)).fork();
5698	>	}
5699	>	for (Node<K,V> p; (p = advance()) != null; )
5700	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5701	>	result = r;
5702	>	CountedCompleter<?> c;
5703	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5704	>	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5705	>	t = (MapReduceKeysToLongTask<K,V>)c,
5706	>	s = t.rights;
5707	>	while (s != null) {
5708	>	t.result = reducer.applyAsLong(t.result, s.result);
5709	>	s = t.rights = s.nextRight;
5710	>	}
5711	>	}
5712	>	}
5713	>	}
5714	>	}
5715	>
5716	>	@SuppressWarnings("serial")
5717	>	static final class MapReduceValuesToLongTask<K,V>
5718	>	extends BulkTask<K,V,Long> {
5719	>	final ToLongFunction<? super V> transformer;
5720	>	final LongBinaryOperator reducer;
5721	>	final long basis;
5722	>	long result;
5723	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5724	>	MapReduceValuesToLongTask
5725	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5726	>	MapReduceValuesToLongTask<K,V> nextRight,
5727	>	ToLongFunction<? super V> transformer,
5728	>	long basis,
5729	>	LongBinaryOperator reducer) {
5730	>	super(p, b, i, f, t); this.nextRight = nextRight;
5731	>	this.transformer = transformer;
5732	>	this.basis = basis; this.reducer = reducer;
5733	>	}
5734	>	public final Long getRawResult() { return result; }
5735	>	public final void compute() {
5736	>	final ToLongFunction<? super V> transformer;
5737	>	final LongBinaryOperator reducer;
5738	>	if ((transformer = this.transformer) != null &&
5739	>	(reducer = this.reducer) != null) {
5740	>	long r = this.basis;
5741	>	for (int i = baseIndex, f, h; batch > 0 &&
5742	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5743	>	addToPendingCount(1);
5744	>	(rights = new MapReduceValuesToLongTask<K,V>
5745	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5746	>	rights, transformer, r, reducer)).fork();
5747	>	}
5748	>	for (Node<K,V> p; (p = advance()) != null; )
5749	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5750	>	result = r;
5751	>	CountedCompleter<?> c;
5752	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5753	>	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
5754	>	t = (MapReduceValuesToLongTask<K,V>)c,
5755	>	s = t.rights;
5756	>	while (s != null) {
5757	>	t.result = reducer.applyAsLong(t.result, s.result);
5758	>	s = t.rights = s.nextRight;
5759	>	}
5760	>	}
5761	>	}
5762	>	}
5763	>	}
5764	>
5765	>	@SuppressWarnings("serial")
5766	>	static final class MapReduceEntriesToLongTask<K,V>
5767	>	extends BulkTask<K,V,Long> {
5768	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5769	>	final LongBinaryOperator reducer;
5770	>	final long basis;
5771	>	long result;
5772	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5773	>	MapReduceEntriesToLongTask
5774	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5775	>	MapReduceEntriesToLongTask<K,V> nextRight,
5776	>	ToLongFunction<Map.Entry<K,V>> transformer,
5777	>	long basis,
5778	>	LongBinaryOperator reducer) {
5779	>	super(p, b, i, f, t); this.nextRight = nextRight;
5780	>	this.transformer = transformer;
5781	>	this.basis = basis; this.reducer = reducer;
5782	>	}
5783	>	public final Long getRawResult() { return result; }
5784	>	public final void compute() {
5785	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5786	>	final LongBinaryOperator reducer;
5787	>	if ((transformer = this.transformer) != null &&
5788	>	(reducer = this.reducer) != null) {
5789	>	long r = this.basis;
5790	>	for (int i = baseIndex, f, h; batch > 0 &&
5791	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5792	>	addToPendingCount(1);
5793	>	(rights = new MapReduceEntriesToLongTask<K,V>
5794	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5795	>	rights, transformer, r, reducer)).fork();
5796	>	}
5797	>	for (Node<K,V> p; (p = advance()) != null; )
5798	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5799	>	result = r;
5800	>	CountedCompleter<?> c;
5801	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5802	>	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
5803	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5804	>	s = t.rights;
5805	>	while (s != null) {
5806	>	t.result = reducer.applyAsLong(t.result, s.result);
5807	>	s = t.rights = s.nextRight;
5808	>	}
5809	>	}
5810	>	}
5811	>	}
5812	>	}
5813	>
5814	>	@SuppressWarnings("serial")
5815	>	static final class MapReduceMappingsToLongTask<K,V>
5816	>	extends BulkTask<K,V,Long> {
5817	>	final ToLongBiFunction<? super K, ? super V> transformer;
5818	>	final LongBinaryOperator reducer;
5819	>	final long basis;
5820	>	long result;
5821	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
5822	>	MapReduceMappingsToLongTask
5823	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5824	>	MapReduceMappingsToLongTask<K,V> nextRight,
5825	>	ToLongBiFunction<? super K, ? super V> transformer,
5826	>	long basis,
5827	>	LongBinaryOperator reducer) {
5828	>	super(p, b, i, f, t); this.nextRight = nextRight;
5829	>	this.transformer = transformer;
5830	>	this.basis = basis; this.reducer = reducer;
5831	>	}
5832	>	public final Long getRawResult() { return result; }
5833	>	public final void compute() {
5834	>	final ToLongBiFunction<? super K, ? super V> transformer;
5835	>	final LongBinaryOperator reducer;
5836	>	if ((transformer = this.transformer) != null &&
5837	>	(reducer = this.reducer) != null) {
5838	>	long r = this.basis;
5839	>	for (int i = baseIndex, f, h; batch > 0 &&
5840	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5841	>	addToPendingCount(1);
5842	>	(rights = new MapReduceMappingsToLongTask<K,V>
5843	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5844	>	rights, transformer, r, reducer)).fork();
5845	>	}
5846	>	for (Node<K,V> p; (p = advance()) != null; )
5847	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
5848	>	result = r;
5849	>	CountedCompleter<?> c;
5850	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5851	>	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
5852	>	t = (MapReduceMappingsToLongTask<K,V>)c,
5853	>	s = t.rights;
5854	>	while (s != null) {
5855	>	t.result = reducer.applyAsLong(t.result, s.result);
5856	>	s = t.rights = s.nextRight;
5857	>	}
5858	>	}
5859	>	}
5860	>	}
5861	>	}
5862	>
5863	>	@SuppressWarnings("serial")
5864	>	static final class MapReduceKeysToIntTask<K,V>
5865	>	extends BulkTask<K,V,Integer> {
5866	>	final ToIntFunction<? super K> transformer;
5867	>	final IntBinaryOperator reducer;
5868	>	final int basis;
5869	>	int result;
5870	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
5871	>	MapReduceKeysToIntTask
5872	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5873	>	MapReduceKeysToIntTask<K,V> nextRight,
5874	>	ToIntFunction<? super K> transformer,
5875	>	int basis,
5876	>	IntBinaryOperator reducer) {
5877	>	super(p, b, i, f, t); this.nextRight = nextRight;
5878	>	this.transformer = transformer;
5879	>	this.basis = basis; this.reducer = reducer;
5880	>	}
5881	>	public final Integer getRawResult() { return result; }
5882	>	public final void compute() {
5883	>	final ToIntFunction<? super K> transformer;
5884	>	final IntBinaryOperator reducer;
5885	>	if ((transformer = this.transformer) != null &&
5886	>	(reducer = this.reducer) != null) {
5887	>	int r = this.basis;
5888	>	for (int i = baseIndex, f, h; batch > 0 &&
5889	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5890	>	addToPendingCount(1);
5891	>	(rights = new MapReduceKeysToIntTask<K,V>
5892	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5893	>	rights, transformer, r, reducer)).fork();
5894	>	}
5895	>	for (Node<K,V> p; (p = advance()) != null; )
5896	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
5897	>	result = r;
5898	>	CountedCompleter<?> c;
5899	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5900	>	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
5901	>	t = (MapReduceKeysToIntTask<K,V>)c,
5902	>	s = t.rights;
5903	>	while (s != null) {
5904	>	t.result = reducer.applyAsInt(t.result, s.result);
5905	>	s = t.rights = s.nextRight;
5906	>	}
5907	>	}
5908	>	}
5909	>	}
5910	>	}
5911	>
5912	>	@SuppressWarnings("serial")
5913	>	static final class MapReduceValuesToIntTask<K,V>
5914	>	extends BulkTask<K,V,Integer> {
5915	>	final ToIntFunction<? super V> transformer;
5916	>	final IntBinaryOperator reducer;
5917	>	final int basis;
5918	>	int result;
5919	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
5920	>	MapReduceValuesToIntTask
5921	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5922	>	MapReduceValuesToIntTask<K,V> nextRight,
5923	>	ToIntFunction<? super V> transformer,
5924	>	int basis,
5925	>	IntBinaryOperator reducer) {
5926	>	super(p, b, i, f, t); this.nextRight = nextRight;
5927	>	this.transformer = transformer;
5928	>	this.basis = basis; this.reducer = reducer;
5929	>	}
5930	>	public final Integer getRawResult() { return result; }
5931	>	public final void compute() {
5932	>	final ToIntFunction<? super V> transformer;
5933	>	final IntBinaryOperator reducer;
5934	>	if ((transformer = this.transformer) != null &&
5935	>	(reducer = this.reducer) != null) {
5936	>	int r = this.basis;
5937	>	for (int i = baseIndex, f, h; batch > 0 &&
5938	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5939	>	addToPendingCount(1);
5940	>	(rights = new MapReduceValuesToIntTask<K,V>
5941	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5942	>	rights, transformer, r, reducer)).fork();
5943	>	}
5944	>	for (Node<K,V> p; (p = advance()) != null; )
5945	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
5946	>	result = r;
5947	>	CountedCompleter<?> c;
5948	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5949	>	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
5950	>	t = (MapReduceValuesToIntTask<K,V>)c,
5951	>	s = t.rights;
5952	>	while (s != null) {
5953	>	t.result = reducer.applyAsInt(t.result, s.result);
5954	>	s = t.rights = s.nextRight;
5955	>	}
5956	>	}
5957	>	}
5958	>	}
5959	>	}
5960	>
5961	>	@SuppressWarnings("serial")
5962	>	static final class MapReduceEntriesToIntTask<K,V>
5963	>	extends BulkTask<K,V,Integer> {
5964	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5965	>	final IntBinaryOperator reducer;
5966	>	final int basis;
5967	>	int result;
5968	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
5969	>	MapReduceEntriesToIntTask
5970	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5971	>	MapReduceEntriesToIntTask<K,V> nextRight,
5972	>	ToIntFunction<Map.Entry<K,V>> transformer,
5973	>	int basis,
5974	>	IntBinaryOperator reducer) {
5975	>	super(p, b, i, f, t); this.nextRight = nextRight;
5976	>	this.transformer = transformer;
5977	>	this.basis = basis; this.reducer = reducer;
5978	>	}
5979	>	public final Integer getRawResult() { return result; }
5980	>	public final void compute() {
5981	>	final ToIntFunction<Map.Entry<K,V>> transformer;
5982	>	final IntBinaryOperator reducer;
5983	>	if ((transformer = this.transformer) != null &&
5984	>	(reducer = this.reducer) != null) {
5985	>	int r = this.basis;
5986	>	for (int i = baseIndex, f, h; batch > 0 &&
5987	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5988	>	addToPendingCount(1);
5989	>	(rights = new MapReduceEntriesToIntTask<K,V>
5990	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5991	>	rights, transformer, r, reducer)).fork();
5992	>	}
5993	>	for (Node<K,V> p; (p = advance()) != null; )
5994	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
5995	>	result = r;
5996	>	CountedCompleter<?> c;
5997	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5998	>	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
5999	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6000	>	s = t.rights;
6001	>	while (s != null) {
6002	>	t.result = reducer.applyAsInt(t.result, s.result);
6003	>	s = t.rights = s.nextRight;
6004	>	}
6005	>	}
6006	>	}
6007	>	}
6008	>	}
6009	>
6010	>	@SuppressWarnings("serial")
6011	>	static final class MapReduceMappingsToIntTask<K,V>
6012	>	extends BulkTask<K,V,Integer> {
6013	>	final ToIntBiFunction<? super K, ? super V> transformer;
6014	>	final IntBinaryOperator reducer;
6015	>	final int basis;
6016	>	int result;
6017	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6018	>	MapReduceMappingsToIntTask
6019	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6020	>	MapReduceMappingsToIntTask<K,V> nextRight,
6021	>	ToIntBiFunction<? super K, ? super V> transformer,
6022	>	int basis,
6023	>	IntBinaryOperator reducer) {
6024	>	super(p, b, i, f, t); this.nextRight = nextRight;
6025	>	this.transformer = transformer;
6026	>	this.basis = basis; this.reducer = reducer;
6027	>	}
6028	>	public final Integer getRawResult() { return result; }
6029	>	public final void compute() {
6030	>	final ToIntBiFunction<? super K, ? super V> transformer;
6031	>	final IntBinaryOperator reducer;
6032	>	if ((transformer = this.transformer) != null &&
6033	>	(reducer = this.reducer) != null) {
6034	>	int r = this.basis;
6035	>	for (int i = baseIndex, f, h; batch > 0 &&
6036	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6037	>	addToPendingCount(1);
6038	>	(rights = new MapReduceMappingsToIntTask<K,V>
6039	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6040	>	rights, transformer, r, reducer)).fork();
6041	>	}
6042	>	for (Node<K,V> p; (p = advance()) != null; )
6043	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6044	>	result = r;
6045	>	CountedCompleter<?> c;
6046	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6047	>	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6048	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6049	>	s = t.rights;
6050	>	while (s != null) {
6051	>	t.result = reducer.applyAsInt(t.result, s.result);
6052	>	s = t.rights = s.nextRight;
6053	>	}
6054	>	}
6055	>	}
6056		}
6057		}
6058
6059		// Unsafe mechanics
6060	<	private static final sun.misc.Unsafe UNSAFE;
6061	<	private static final long SBASE;
6062	<	private static final int SSHIFT;
6063	<	private static final long TBASE;
6064	<	private static final int TSHIFT;
6060	>	private static final sun.misc.Unsafe U;
6061	>	private static final long SIZECTL;
6062	>	private static final long TRANSFERINDEX;
6063	>	private static final long TRANSFERORIGIN;
6064	>	private static final long BASECOUNT;
6065	>	private static final long CELLSBUSY;
6066	>	private static final long CELLVALUE;
6067	>	private static final long ABASE;
6068	>	private static final int ASHIFT;
6069
6070		static {
1474	–	int ss, ts;
6071		try {
6072	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6073	<	Class tc = HashEntry[].class;
6074	<	Class sc = Segment[].class;
6075	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6076	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6077	<	ts = UNSAFE.arrayIndexScale(tc);
6078	<	ss = UNSAFE.arrayIndexScale(sc);
6072	>	U = sun.misc.Unsafe.getUnsafe();
6073	>	Class<?> k = ConcurrentHashMap.class;
6074	>	SIZECTL = U.objectFieldOffset
6075	>	(k.getDeclaredField("sizeCtl"));
6076	>	TRANSFERINDEX = U.objectFieldOffset
6077	>	(k.getDeclaredField("transferIndex"));
6078	>	TRANSFERORIGIN = U.objectFieldOffset
6079	>	(k.getDeclaredField("transferOrigin"));
6080	>	BASECOUNT = U.objectFieldOffset
6081	>	(k.getDeclaredField("baseCount"));
6082	>	CELLSBUSY = U.objectFieldOffset
6083	>	(k.getDeclaredField("cellsBusy"));
6084	>	Class<?> ck = CounterCell.class;
6085	>	CELLVALUE = U.objectFieldOffset
6086	>	(ck.getDeclaredField("value"));
6087	>	Class<?> ak = Node[].class;
6088	>	ABASE = U.arrayBaseOffset(ak);
6089	>	int scale = U.arrayIndexScale(ak);
6090	>	if ((scale & (scale - 1)) != 0)
6091	>	throw new Error("data type scale not a power of two");
6092	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6093		} catch (Exception e) {
6094		throw new Error(e);
6095		}
1486	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1487	–	throw new Error("data type scale not a power of two");
1488	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1489	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6096		}
1491	–
6097		}

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