ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/jsr166/jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java

Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.112 by jsr166, Fri Jun 3 02:28:05 2011 UTC vs.
Revision 1.262 by jsr166, Sun Jan 4 01:06:15 2015 UTC

#	Line 5 | Line 5
5		*/
6
7		package java.util.concurrent;
8	<	import java.util.concurrent.locks.*;
9	<	import java.util.*;
8	>
9	>	import java.io.ObjectStreamField;
10		import java.io.Serializable;
11	<	import java.io.IOException;
12	<	import java.io.ObjectInputStream;
13	<	import java.io.ObjectOutputStream;
11	>	import java.lang.reflect.ParameterizedType;
12	>	import java.lang.reflect.Type;
13	>	import java.util.AbstractMap;
14	>	import java.util.Arrays;
15	>	import java.util.Collection;
16	>	import java.util.Enumeration;
17	>	import java.util.HashMap;
18	>	import java.util.Hashtable;
19	>	import java.util.Iterator;
20	>	import java.util.Map;
21	>	import java.util.NoSuchElementException;
22	>	import java.util.Set;
23	>	import java.util.Spliterator;
24	>	import java.util.concurrent.atomic.AtomicReference;
25	>	import java.util.concurrent.locks.LockSupport;
26	>	import java.util.concurrent.locks.ReentrantLock;
27	>	import java.util.function.BiConsumer;
28	>	import java.util.function.BiFunction;
29	>	import java.util.function.Consumer;
30	>	import java.util.function.DoubleBinaryOperator;
31	>	import java.util.function.Function;
32	>	import java.util.function.IntBinaryOperator;
33	>	import java.util.function.LongBinaryOperator;
34	>	import java.util.function.ToDoubleBiFunction;
35	>	import java.util.function.ToDoubleFunction;
36	>	import java.util.function.ToIntBiFunction;
37	>	import java.util.function.ToIntFunction;
38	>	import java.util.function.ToLongBiFunction;
39	>	import java.util.function.ToLongFunction;
40	>	import java.util.stream.Stream;
41
42		/**
43		* A hash table supporting full concurrency of retrievals and
44	<	* adjustable expected concurrency for updates. This class obeys the
44	>	* high expected concurrency for updates. This class obeys the
45		* same functional specification as {@link java.util.Hashtable}, and
46		* includes versions of methods corresponding to each method of
47	<	* <tt>Hashtable</tt>. However, even though all operations are
47	>	* {@code Hashtable}. However, even though all operations are
48		* thread-safe, retrieval operations do <em>not</em> entail locking,
49		* and there is <em>not</em> any support for locking the entire table
50		* in a way that prevents all access.  This class is fully
51	<	* interoperable with <tt>Hashtable</tt> in programs that rely on its
51	>	* interoperable with {@code Hashtable} in programs that rely on its
52		* thread safety but not on its synchronization details.
53		*
54	<	* <p> Retrieval operations (including <tt>get</tt>) generally do not
55	<	* block, so may overlap with update operations (including
56	<	* <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
57	<	* of the most recently <em>completed</em> update operations holding
58	<	* upon their onset.  For aggregate operations such as <tt>putAll</tt>
59	<	* and <tt>clear</tt>, concurrent retrievals may reflect insertion or
60	<	* removal of only some entries.  Similarly, Iterators and
61	<	* Enumerations return elements reflecting the state of the hash table
62	<	* at some point at or since the creation of the iterator/enumeration.
63	<	* They do <em>not</em> throw {@link ConcurrentModificationException}.
54	>	* <p>Retrieval operations (including {@code get}) generally do not
55	>	* block, so may overlap with update operations (including {@code put}
56	>	* and {@code remove}). Retrievals reflect the results of the most
57	>	* recently <em>completed</em> update operations holding upon their
58	>	* onset. (More formally, an update operation for a given key bears a
59	>	* <em>happens-before</em> relation with any (non-null) retrieval for
60	>	* that key reporting the updated value.)  For aggregate operations
61	>	* such as {@code putAll} and {@code clear}, concurrent retrievals may
62	>	* reflect insertion or removal of only some entries.  Similarly,
63	>	* Iterators, Spliterators and Enumerations return elements reflecting the
64	>	* state of the hash table at some point at or since the creation of the
65	>	* iterator/enumeration.  They do <em>not</em> throw {@link
66	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
67		* However, iterators are designed to be used by only one thread at a time.
68	+	* Bear in mind that the results of aggregate status methods including
69	+	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
70	+	* useful only when a map is not undergoing concurrent updates in other threads.
71	+	* Otherwise the results of these methods reflect transient states
72	+	* that may be adequate for monitoring or estimation purposes, but not
73	+	* for program control.
74	+	*
75	+	* <p>The table is dynamically expanded when there are too many
76	+	* collisions (i.e., keys that have distinct hash codes but fall into
77	+	* the same slot modulo the table size), with the expected average
78	+	* effect of maintaining roughly two bins per mapping (corresponding
79	+	* to a 0.75 load factor threshold for resizing). There may be much
80	+	* variance around this average as mappings are added and removed, but
81	+	* overall, this maintains a commonly accepted time/space tradeoff for
82	+	* hash tables.  However, resizing this or any other kind of hash
83	+	* table may be a relatively slow operation. When possible, it is a
84	+	* good idea to provide a size estimate as an optional {@code
85	+	* initialCapacity} constructor argument. An additional optional
86	+	* {@code loadFactor} constructor argument provides a further means of
87	+	* customizing initial table capacity by specifying the table density
88	+	* to be used in calculating the amount of space to allocate for the
89	+	* given number of elements.  Also, for compatibility with previous
90	+	* versions of this class, constructors may optionally specify an
91	+	* expected {@code concurrencyLevel} as an additional hint for
92	+	* internal sizing.  Note that using many keys with exactly the same
93	+	* {@code hashCode()} is a sure way to slow down performance of any
94	+	* hash table. To ameliorate impact, when keys are {@link Comparable},
95	+	* this class may use comparison order among keys to help break ties.
96	+	*
97	+	* <p>A {@link Set} projection of a ConcurrentHashMap may be created
98	+	* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
99	+	* (using {@link #keySet(Object)} when only keys are of interest, and the
100	+	* mapped values are (perhaps transiently) not used or all take the
101	+	* same mapping value.
102		*
103	<	* <p> The allowed concurrency among update operations is guided by
104	<	* the optional <tt>concurrencyLevel</tt> constructor argument
105	<	* (default <tt>16</tt>), which is used as a hint for internal sizing.  The
106	<	* table is internally partitioned to try to permit the indicated
107	<	* number of concurrent updates without contention. Because placement
108	<	* in hash tables is essentially random, the actual concurrency will
45	<	* vary.  Ideally, you should choose a value to accommodate as many
46	<	* threads as will ever concurrently modify the table. Using a
47	<	* significantly higher value than you need can waste space and time,
48	<	* and a significantly lower value can lead to thread contention. But
49	<	* overestimates and underestimates within an order of magnitude do
50	<	* not usually have much noticeable impact. A value of one is
51	<	* appropriate when it is known that only one thread will modify and
52	<	* all others will only read. Also, resizing this or any other kind of
53	<	* hash table is a relatively slow operation, so, when possible, it is
54	<	* a good idea to provide estimates of expected table sizes in
55	<	* constructors.
103	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
104	>	* form of histogram or multiset) by using {@link
105	>	* java.util.concurrent.atomic.LongAdder} values and initializing via
106	>	* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
107	>	* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
108	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
109		*
110		* <p>This class and its views and iterators implement all of the
111		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
112		* interfaces.
113		*
114	<	* <p> Like {@link Hashtable} but unlike {@link HashMap}, this class
115	<	* does <em>not</em> allow <tt>null</tt> to be used as a key or value.
114	>	* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
115	>	* does <em>not</em> allow {@code null} to be used as a key or value.
116	>	*
117	>	* <p>ConcurrentHashMaps support a set of sequential and parallel bulk
118	>	* operations that, unlike most {@link Stream} methods, are designed
119	>	* to be safely, and often sensibly, applied even with maps that are
120	>	* being concurrently updated by other threads; for example, when
121	>	* computing a snapshot summary of the values in a shared registry.
122	>	* There are three kinds of operation, each with four forms, accepting
123	>	* functions with Keys, Values, Entries, and (Key, Value) arguments
124	>	* and/or return values. Because the elements of a ConcurrentHashMap
125	>	* are not ordered in any particular way, and may be processed in
126	>	* different orders in different parallel executions, the correctness
127	>	* of supplied functions should not depend on any ordering, or on any
128	>	* other objects or values that may transiently change while
129	>	* computation is in progress; and except for forEach actions, should
130	>	* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
131	>	* objects do not support method {@code setValue}.
132	>	*
133	>	* <ul>
134	>	* <li> forEach: Perform a given action on each element.
135	>	* A variant form applies a given transformation on each element
136	>	* before performing the action.</li>
137	>	*
138	>	* <li> search: Return the first available non-null result of
139	>	* applying a given function on each element; skipping further
140	>	* search when a result is found.</li>
141	>	*
142	>	* <li> reduce: Accumulate each element.  The supplied reduction
143	>	* function cannot rely on ordering (more formally, it should be
144	>	* both associative and commutative).  There are five variants:
145	>	*
146	>	* <ul>
147	>	*
148	>	* <li> Plain reductions. (There is not a form of this method for
149	>	* (key, value) function arguments since there is no corresponding
150	>	* return type.)</li>
151	>	*
152	>	* <li> Mapped reductions that accumulate the results of a given
153	>	* function applied to each element.</li>
154	>	*
155	>	* <li> Reductions to scalar doubles, longs, and ints, using a
156	>	* given basis value.</li>
157	>	*
158	>	* </ul>
159	>	* </li>
160	>	* </ul>
161	>	*
162	>	* <p>These bulk operations accept a {@code parallelismThreshold}
163	>	* argument. Methods proceed sequentially if the current map size is
164	>	* estimated to be less than the given threshold. Using a value of
165	>	* {@code Long.MAX_VALUE} suppresses all parallelism.  Using a value
166	>	* of {@code 1} results in maximal parallelism by partitioning into
167	>	* enough subtasks to fully utilize the {@link
168	>	* ForkJoinPool#commonPool()} that is used for all parallel
169	>	* computations. Normally, you would initially choose one of these
170	>	* extreme values, and then measure performance of using in-between
171	>	* values that trade off overhead versus throughput.
172	>	*
173	>	* <p>The concurrency properties of bulk operations follow
174	>	* from those of ConcurrentHashMap: Any non-null result returned
175	>	* from {@code get(key)} and related access methods bears a
176	>	* happens-before relation with the associated insertion or
177	>	* update.  The result of any bulk operation reflects the
178	>	* composition of these per-element relations (but is not
179	>	* necessarily atomic with respect to the map as a whole unless it
180	>	* is somehow known to be quiescent).  Conversely, because keys
181	>	* and values in the map are never null, null serves as a reliable
182	>	* atomic indicator of the current lack of any result.  To
183	>	* maintain this property, null serves as an implicit basis for
184	>	* all non-scalar reduction operations. For the double, long, and
185	>	* int versions, the basis should be one that, when combined with
186	>	* any other value, returns that other value (more formally, it
187	>	* should be the identity element for the reduction). Most common
188	>	* reductions have these properties; for example, computing a sum
189	>	* with basis 0 or a minimum with basis MAX_VALUE.
190	>	*
191	>	* <p>Search and transformation functions provided as arguments
192	>	* should similarly return null to indicate the lack of any result
193	>	* (in which case it is not used). In the case of mapped
194	>	* reductions, this also enables transformations to serve as
195	>	* filters, returning null (or, in the case of primitive
196	>	* specializations, the identity basis) if the element should not
197	>	* be combined. You can create compound transformations and
198	>	* filterings by composing them yourself under this "null means
199	>	* there is nothing there now" rule before using them in search or
200	>	* reduce operations.
201	>	*
202	>	* <p>Methods accepting and/or returning Entry arguments maintain
203	>	* key-value associations. They may be useful for example when
204	>	* finding the key for the greatest value. Note that "plain" Entry
205	>	* arguments can be supplied using {@code new
206	>	* AbstractMap.SimpleEntry(k,v)}.
207	>	*
208	>	* <p>Bulk operations may complete abruptly, throwing an
209	>	* exception encountered in the application of a supplied
210	>	* function. Bear in mind when handling such exceptions that other
211	>	* concurrently executing functions could also have thrown
212	>	* exceptions, or would have done so if the first exception had
213	>	* not occurred.
214	>	*
215	>	* <p>Speedups for parallel compared to sequential forms are common
216	>	* but not guaranteed.  Parallel operations involving brief functions
217	>	* on small maps may execute more slowly than sequential forms if the
218	>	* underlying work to parallelize the computation is more expensive
219	>	* than the computation itself.  Similarly, parallelization may not
220	>	* lead to much actual parallelism if all processors are busy
221	>	* performing unrelated tasks.
222	>	*
223	>	* <p>All arguments to all task methods must be non-null.
224		*
225		* <p>This class is a member of the
226		* <a href="{@docRoot}/../technotes/guides/collections/index.html">
#	Line 70 | Line 231 | import java.io.ObjectOutputStream;
231		* @param <K> the type of keys maintained by this map
232		* @param <V> the type of mapped values
233		*/
234	<	public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
235	<	implements ConcurrentMap<K, V>, Serializable {
234	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
235	>	implements ConcurrentMap<K,V>, Serializable {
236		private static final long serialVersionUID = 7249069246763182397L;
237
238		/*
239	<	* The basic strategy is to subdivide the table among Segments,
240	<	* each of which itself is a concurrently readable hash table.  To
241	<	* reduce footprint, all but one segments are constructed only
242	<	* when first needed (see ensureSegment). To maintain visibility
243	<	* in the presence of lazy construction, accesses to segments as
244	<	* well as elements of segment's table must use volatile access,
245	<	* which is done via Unsafe within methods segmentAt etc
246	<	* below. These provide the functionality of AtomicReferenceArrays
247	<	* but reduce the levels of indirection. Additionally,
248	<	* volatile-writes of table elements and entry "next" fields
249	<	* within locked operations use the cheaper "lazySet" forms of
250	<	* writes (via putOrderedObject) because these writes are always
251	<	* followed by lock releases that maintain sequential consistency
252	<	* of table updates.
253	<	*
254	<	* Historical note: The previous version of this class relied
255	<	* heavily on "final" fields, which avoided some volatile reads at
256	<	* the expense of a large initial footprint.  Some remnants of
257	<	* that design (including forced construction of segment 0) exist
258	<	* to ensure serialization compatibility.
239	>	* Overview:
240	>	*
241	>	* The primary design goal of this hash table is to maintain
242	>	* concurrent readability (typically method get(), but also
243	>	* iterators and related methods) while minimizing update
244	>	* contention. Secondary goals are to keep space consumption about
245	>	* the same or better than java.util.HashMap, and to support high
246	>	* initial insertion rates on an empty table by many threads.
247	>	*
248	>	* This map usually acts as a binned (bucketed) hash table.  Each
249	>	* key-value mapping is held in a Node.  Most nodes are instances
250	>	* of the basic Node class with hash, key, value, and next
251	>	* fields. However, various subclasses exist: TreeNodes are
252	>	* arranged in balanced trees, not lists.  TreeBins hold the roots
253	>	* of sets of TreeNodes. ForwardingNodes are placed at the heads
254	>	* of bins during resizing. ReservationNodes are used as
255	>	* placeholders while establishing values in computeIfAbsent and
256	>	* related methods.  The types TreeBin, ForwardingNode, and
257	>	* ReservationNode do not hold normal user keys, values, or
258	>	* hashes, and are readily distinguishable during search etc
259	>	* because they have negative hash fields and null key and value
260	>	* fields. (These special nodes are either uncommon or transient,
261	>	* so the impact of carrying around some unused fields is
262	>	* insignificant.)
263	>	*
264	>	* The table is lazily initialized to a power-of-two size upon the
265	>	* first insertion.  Each bin in the table normally contains a
266	>	* list of Nodes (most often, the list has only zero or one Node).
267	>	* Table accesses require volatile/atomic reads, writes, and
268	>	* CASes.  Because there is no other way to arrange this without
269	>	* adding further indirections, we use intrinsics
270	>	* (sun.misc.Unsafe) operations.
271	>	*
272	>	* We use the top (sign) bit of Node hash fields for control
273	>	* purposes -- it is available anyway because of addressing
274	>	* constraints.  Nodes with negative hash fields are specially
275	>	* handled or ignored in map methods.
276	>	*
277	>	* Insertion (via put or its variants) of the first node in an
278	>	* empty bin is performed by just CASing it to the bin.  This is
279	>	* by far the most common case for put operations under most
280	>	* key/hash distributions.  Other update operations (insert,
281	>	* delete, and replace) require locks.  We do not want to waste
282	>	* the space required to associate a distinct lock object with
283	>	* each bin, so instead use the first node of a bin list itself as
284	>	* a lock. Locking support for these locks relies on builtin
285	>	* "synchronized" monitors.
286	>	*
287	>	* Using the first node of a list as a lock does not by itself
288	>	* suffice though: When a node is locked, any update must first
289	>	* validate that it is still the first node after locking it, and
290	>	* retry if not. Because new nodes are always appended to lists,
291	>	* once a node is first in a bin, it remains first until deleted
292	>	* or the bin becomes invalidated (upon resizing).
293	>	*
294	>	* The main disadvantage of per-bin locks is that other update
295	>	* operations on other nodes in a bin list protected by the same
296	>	* lock can stall, for example when user equals() or mapping
297	>	* functions take a long time.  However, statistically, under
298	>	* random hash codes, this is not a common problem.  Ideally, the
299	>	* frequency of nodes in bins follows a Poisson distribution
300	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
301	>	* parameter of about 0.5 on average, given the resizing threshold
302	>	* of 0.75, although with a large variance because of resizing
303	>	* granularity. Ignoring variance, the expected occurrences of
304	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
305	>	* first values are:
306	>	*
307	>	* 0:    0.60653066
308	>	* 1:    0.30326533
309	>	* 2:    0.07581633
310	>	* 3:    0.01263606
311	>	* 4:    0.00157952
312	>	* 5:    0.00015795
313	>	* 6:    0.00001316
314	>	* 7:    0.00000094
315	>	* 8:    0.00000006
316	>	* more: less than 1 in ten million
317	>	*
318	>	* Lock contention probability for two threads accessing distinct
319	>	* elements is roughly 1 / (8 * #elements) under random hashes.
320	>	*
321	>	* Actual hash code distributions encountered in practice
322	>	* sometimes deviate significantly from uniform randomness.  This
323	>	* includes the case when N > (1<<30), so some keys MUST collide.
324	>	* Similarly for dumb or hostile usages in which multiple keys are
325	>	* designed to have identical hash codes or ones that differs only
326	>	* in masked-out high bits. So we use a secondary strategy that
327	>	* applies when the number of nodes in a bin exceeds a
328	>	* threshold. These TreeBins use a balanced tree to hold nodes (a
329	>	* specialized form of red-black trees), bounding search time to
330	>	* O(log N).  Each search step in a TreeBin is at least twice as
331	>	* slow as in a regular list, but given that N cannot exceed
332	>	* (1<<64) (before running out of addresses) this bounds search
333	>	* steps, lock hold times, etc, to reasonable constants (roughly
334	>	* 100 nodes inspected per operation worst case) so long as keys
335	>	* are Comparable (which is very common -- String, Long, etc).
336	>	* TreeBin nodes (TreeNodes) also maintain the same "next"
337	>	* traversal pointers as regular nodes, so can be traversed in
338	>	* iterators in the same way.
339	>	*
340	>	* The table is resized when occupancy exceeds a percentage
341	>	* threshold (nominally, 0.75, but see below).  Any thread
342	>	* noticing an overfull bin may assist in resizing after the
343	>	* initiating thread allocates and sets up the replacement array.
344	>	* However, rather than stalling, these other threads may proceed
345	>	* with insertions etc.  The use of TreeBins shields us from the
346	>	* worst case effects of overfilling while resizes are in
347	>	* progress.  Resizing proceeds by transferring bins, one by one,
348	>	* from the table to the next table. However, threads claim small
349	>	* blocks of indices to transfer (via field transferIndex) before
350	>	* doing so, reducing contention.  A generation stamp in field
351	>	* sizeCtl ensures that resizings do not overlap. Because we are
352	>	* using power-of-two expansion, the elements from each bin must
353	>	* either stay at same index, or move with a power of two
354	>	* offset. We eliminate unnecessary node creation by catching
355	>	* cases where old nodes can be reused because their next fields
356	>	* won't change.  On average, only about one-sixth of them need
357	>	* cloning when a table doubles. The nodes they replace will be
358	>	* garbage collectable as soon as they are no longer referenced by
359	>	* any reader thread that may be in the midst of concurrently
360	>	* traversing table.  Upon transfer, the old table bin contains
361	>	* only a special forwarding node (with hash field "MOVED") that
362	>	* contains the next table as its key. On encountering a
363	>	* forwarding node, access and update operations restart, using
364	>	* the new table.
365	>	*
366	>	* Each bin transfer requires its bin lock, which can stall
367	>	* waiting for locks while resizing. However, because other
368	>	* threads can join in and help resize rather than contend for
369	>	* locks, average aggregate waits become shorter as resizing
370	>	* progresses.  The transfer operation must also ensure that all
371	>	* accessible bins in both the old and new table are usable by any
372	>	* traversal.  This is arranged in part by proceeding from the
373	>	* last bin (table.length - 1) up towards the first.  Upon seeing
374	>	* a forwarding node, traversals (see class Traverser) arrange to
375	>	* move to the new table without revisiting nodes.  To ensure that
376	>	* no intervening nodes are skipped even when moved out of order,
377	>	* a stack (see class TableStack) is created on first encounter of
378	>	* a forwarding node during a traversal, to maintain its place if
379	>	* later processing the current table. The need for these
380	>	* save/restore mechanics is relatively rare, but when one
381	>	* forwarding node is encountered, typically many more will be.
382	>	* So Traversers use a simple caching scheme to avoid creating so
383	>	* many new TableStack nodes. (Thanks to Peter Levart for
384	>	* suggesting use of a stack here.)
385	>	*
386	>	* The traversal scheme also applies to partial traversals of
387	>	* ranges of bins (via an alternate Traverser constructor)
388	>	* to support partitioned aggregate operations.  Also, read-only
389	>	* operations give up if ever forwarded to a null table, which
390	>	* provides support for shutdown-style clearing, which is also not
391	>	* currently implemented.
392	>	*
393	>	* Lazy table initialization minimizes footprint until first use,
394	>	* and also avoids resizings when the first operation is from a
395	>	* putAll, constructor with map argument, or deserialization.
396	>	* These cases attempt to override the initial capacity settings,
397	>	* but harmlessly fail to take effect in cases of races.
398	>	*
399	>	* The element count is maintained using a specialization of
400	>	* LongAdder. We need to incorporate a specialization rather than
401	>	* just use a LongAdder in order to access implicit
402	>	* contention-sensing that leads to creation of multiple
403	>	* CounterCells.  The counter mechanics avoid contention on
404	>	* updates but can encounter cache thrashing if read too
405	>	* frequently during concurrent access. To avoid reading so often,
406	>	* resizing under contention is attempted only upon adding to a
407	>	* bin already holding two or more nodes. Under uniform hash
408	>	* distributions, the probability of this occurring at threshold
409	>	* is around 13%, meaning that only about 1 in 8 puts check
410	>	* threshold (and after resizing, many fewer do so).
411	>	*
412	>	* TreeBins use a special form of comparison for search and
413	>	* related operations (which is the main reason we cannot use
414	>	* existing collections such as TreeMaps). TreeBins contain
415	>	* Comparable elements, but may contain others, as well as
416	>	* elements that are Comparable but not necessarily Comparable for
417	>	* the same T, so we cannot invoke compareTo among them. To handle
418	>	* this, the tree is ordered primarily by hash value, then by
419	>	* Comparable.compareTo order if applicable.  On lookup at a node,
420	>	* if elements are not comparable or compare as 0 then both left
421	>	* and right children may need to be searched in the case of tied
422	>	* hash values. (This corresponds to the full list search that
423	>	* would be necessary if all elements were non-Comparable and had
424	>	* tied hashes.) On insertion, to keep a total ordering (or as
425	>	* close as is required here) across rebalancings, we compare
426	>	* classes and identityHashCodes as tie-breakers. The red-black
427	>	* balancing code is updated from pre-jdk-collections
428	>	* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
429	>	* based in turn on Cormen, Leiserson, and Rivest "Introduction to
430	>	* Algorithms" (CLR).
431	>	*
432	>	* TreeBins also require an additional locking mechanism.  While
433	>	* list traversal is always possible by readers even during
434	>	* updates, tree traversal is not, mainly because of tree-rotations
435	>	* that may change the root node and/or its linkages.  TreeBins
436	>	* include a simple read-write lock mechanism parasitic on the
437	>	* main bin-synchronization strategy: Structural adjustments
438	>	* associated with an insertion or removal are already bin-locked
439	>	* (and so cannot conflict with other writers) but must wait for
440	>	* ongoing readers to finish. Since there can be only one such
441	>	* waiter, we use a simple scheme using a single "waiter" field to
442	>	* block writers.  However, readers need never block.  If the root
443	>	* lock is held, they proceed along the slow traversal path (via
444	>	* next-pointers) until the lock becomes available or the list is
445	>	* exhausted, whichever comes first. These cases are not fast, but
446	>	* maximize aggregate expected throughput.
447	>	*
448	>	* Maintaining API and serialization compatibility with previous
449	>	* versions of this class introduces several oddities. Mainly: We
450	>	* leave untouched but unused constructor arguments refering to
451	>	* concurrencyLevel. We accept a loadFactor constructor argument,
452	>	* but apply it only to initial table capacity (which is the only
453	>	* time that we can guarantee to honor it.) We also declare an
454	>	* unused "Segment" class that is instantiated in minimal form
455	>	* only when serializing.
456	>	*
457	>	* Also, solely for compatibility with previous versions of this
458	>	* class, it extends AbstractMap, even though all of its methods
459	>	* are overridden, so it is just useless baggage.
460	>	*
461	>	* This file is organized to make things a little easier to follow
462	>	* while reading than they might otherwise: First the main static
463	>	* declarations and utilities, then fields, then main public
464	>	* methods (with a few factorings of multiple public methods into
465	>	* internal ones), then sizing methods, trees, traversers, and
466	>	* bulk operations.
467		*/
468
469		/* ---------------- Constants -------------- */
470
471		/**
472	<	* The default initial capacity for this table,
473	<	* used when not otherwise specified in a constructor.
472	>	* The largest possible table capacity.  This value must be
473	>	* exactly 1<<30 to stay within Java array allocation and indexing
474	>	* bounds for power of two table sizes, and is further required
475	>	* because the top two bits of 32bit hash fields are used for
476	>	* control purposes.
477		*/
478	<	static final int DEFAULT_INITIAL_CAPACITY = 16;
478	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
479
480		/**
481	<	* The default load factor for this table, used when not
482	<	* otherwise specified in a constructor.
481	>	* The default initial table capacity.  Must be a power of 2
482	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
483		*/
484	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
484	>	private static final int DEFAULT_CAPACITY = 16;
485
486		/**
487	<	* The default concurrency level for this table, used when not
488	<	* otherwise specified in a constructor.
487	>	* The largest possible (non-power of two) array size.
488	>	* Needed by toArray and related methods.
489		*/
490	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
490	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
491
492		/**
493	<	* The maximum capacity, used if a higher value is implicitly
494	<	* 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.
493	>	* The default concurrency level for this table. Unused but
494	>	* defined for compatibility with previous versions of this class.
495		*/
496	<	static final int MAXIMUM_CAPACITY = 1 << 30;
496	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
497
498		/**
499	<	* The minimum capacity for per-segment tables.  Must be a power
500	<	* of two, at least two to avoid immediate resizing on next use
501	<	* after lazy construction.
499	>	* The load factor for this table. Overrides of this value in
500	>	* constructors affect only the initial table capacity.  The
501	>	* actual floating point value isn't normally used -- it is
502	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
503	>	* the associated resizing threshold.
504		*/
505	<	static final int MIN_SEGMENT_TABLE_CAPACITY = 2;
505	>	private static final float LOAD_FACTOR = 0.75f;
506
507		/**
508	<	* The maximum number of segments to allow; used to bound
509	<	* constructor arguments. Must be power of two less than 1 << 24.
508	>	* The bin count threshold for using a tree rather than list for a
509	>	* bin.  Bins are converted to trees when adding an element to a
510	>	* bin with at least this many nodes. The value must be greater
511	>	* than 2, and should be at least 8 to mesh with assumptions in
512	>	* tree removal about conversion back to plain bins upon
513	>	* shrinkage.
514		*/
515	<	static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
515	>	static final int TREEIFY_THRESHOLD = 8;
516
517		/**
518	<	* Number of unsynchronized retries in size and containsValue
519	<	* methods before resorting to locking. This is used to avoid
520	<	* unbounded retries if tables undergo continuous modification
145	<	* which would make it impossible to obtain an accurate result.
518	>	* The bin count threshold for untreeifying a (split) bin during a
519	>	* resize operation. Should be less than TREEIFY_THRESHOLD, and at
520	>	* most 6 to mesh with shrinkage detection under removal.
521		*/
522	<	static final int RETRIES_BEFORE_LOCK = 2;
148	<
149	<	/* ---------------- Fields -------------- */
522	>	static final int UNTREEIFY_THRESHOLD = 6;
523
524		/**
525	<	* Mask value for indexing into segments. The upper bits of a
526	<	* key's hash code are used to choose the segment.
525	>	* The smallest table capacity for which bins may be treeified.
526	>	* (Otherwise the table is resized if too many nodes in a bin.)
527	>	* The value should be at least 4 * TREEIFY_THRESHOLD to avoid
528	>	* conflicts between resizing and treeification thresholds.
529		*/
530	<	final int segmentMask;
530	>	static final int MIN_TREEIFY_CAPACITY = 64;
531
532		/**
533	<	* Shift value for indexing within segments.
533	>	* Minimum number of rebinnings per transfer step. Ranges are
534	>	* subdivided to allow multiple resizer threads.  This value
535	>	* serves as a lower bound to avoid resizers encountering
536	>	* excessive memory contention.  The value should be at least
537	>	* DEFAULT_CAPACITY.
538		*/
539	<	final int segmentShift;
539	>	private static final int MIN_TRANSFER_STRIDE = 16;
540
541		/**
542	<	* The segments, each of which is a specialized hash table.
542	>	* The number of bits used for generation stamp in sizeCtl.
543	>	* Must be at least 6 for 32bit arrays.
544		*/
545	<	final Segment<K,V>[] segments;
545	>	private static int RESIZE_STAMP_BITS = 16;
546
547	<	transient Set<K> keySet;
548	<	transient Set<Map.Entry<K,V>> entrySet;
549	<	transient Collection<V> values;
547	>	/**
548	>	* The maximum number of threads that can help resize.
549	>	* Must fit in 32 - RESIZE_STAMP_BITS bits.
550	>	*/
551	>	private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
552
553		/**
554	<	* ConcurrentHashMap list entry. Note that this is never exported
555	<	* out as a user-visible Map.Entry.
554	>	* The bit shift for recording size stamp in sizeCtl.
555	>	*/
556	>	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
557	>
558	>	/*
559	>	* Encodings for Node hash fields. See above for explanation.
560	>	*/
561	>	static final int MOVED     = -1; // hash for forwarding nodes
562	>	static final int TREEBIN   = -2; // hash for roots of trees
563	>	static final int RESERVED  = -3; // hash for transient reservations
564	>	static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
565	>
566	>	/** Number of CPUS, to place bounds on some sizings */
567	>	static final int NCPU = Runtime.getRuntime().availableProcessors();
568	>
569	>	/** For serialization compatibility. */
570	>	private static final ObjectStreamField[] serialPersistentFields = {
571	>	new ObjectStreamField("segments", Segment[].class),
572	>	new ObjectStreamField("segmentMask", Integer.TYPE),
573	>	new ObjectStreamField("segmentShift", Integer.TYPE)
574	>	};
575	>
576	>	/* ---------------- Nodes -------------- */
577	>
578	>	/**
579	>	* Key-value entry.  This class is never exported out as a
580	>	* user-mutable Map.Entry (i.e., one supporting setValue; see
581	>	* MapEntry below), but can be used for read-only traversals used
582	>	* in bulk tasks.  Subclasses of Node with a negative hash field
583	>	* are special, and contain null keys and values (but are never
584	>	* exported).  Otherwise, keys and vals are never null.
585		*/
586	<	static final class HashEntry<K,V> {
586	>	static class Node<K,V> implements Map.Entry<K,V> {
587		final int hash;
588		final K key;
589	<	volatile V value;
590	<	volatile HashEntry<K,V> next;
589	>	volatile V val;
590	>	volatile Node<K,V> next;
591
592	<	HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
592	>	Node(int hash, K key, V val, Node<K,V> next) {
593		this.hash = hash;
594		this.key = key;
595	<	this.value = value;
595	>	this.val = val;
596		this.next = next;
597		}
598
599	+	public final K getKey()       { return key; }
600	+	public final V getValue()     { return val; }
601	+	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
602	+	public final String toString(){ return key + "=" + val; }
603	+	public final V setValue(V value) {
604	+	throw new UnsupportedOperationException();
605	+	}
606	+
607	+	public final boolean equals(Object o) {
608	+	Object k, v, u; Map.Entry<?,?> e;
609	+	return ((o instanceof Map.Entry) &&
610	+	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
611	+	(v = e.getValue()) != null &&
612	+	(k == key || k.equals(key)) &&
613	+	(v == (u = val) || v.equals(u)));
614	+	}
615	+
616		/**
617	<	* Sets next field with volatile write semantics.  (See above
190	<	* about use of putOrderedObject.)
617	>	* Virtualized support for map.get(); overridden in subclasses.
618		*/
619	<	final void setNext(HashEntry<K,V> n) {
620	<	UNSAFE.putOrderedObject(this, nextOffset, n);
619	>	Node<K,V> find(int h, Object k) {
620	>	Node<K,V> e = this;
621	>	if (k != null) {
622	>	do {
623	>	K ek;
624	>	if (e.hash == h &&
625	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
626	>	return e;
627	>	} while ((e = e.next) != null);
628	>	}
629	>	return null;
630		}
631	+	}
632
633	<	// Unsafe mechanics
634	<	static final sun.misc.Unsafe UNSAFE;
635	<	static final long nextOffset;
636	<	static {
637	<	try {
638	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
639	<	Class<?> k = HashEntry.class;
640	<	nextOffset = UNSAFE.objectFieldOffset
641	<	(k.getDeclaredField("next"));
642	<	} catch (Exception e) {
643	<	throw new Error(e);
633	>	/* ---------------- Static utilities -------------- */
634	>
635	>	/**
636	>	* Spreads (XORs) higher bits of hash to lower and also forces top
637	>	* bit to 0. Because the table uses power-of-two masking, sets of
638	>	* hashes that vary only in bits above the current mask will
639	>	* always collide. (Among known examples are sets of Float keys
640	>	* holding consecutive whole numbers in small tables.)  So we
641	>	* apply a transform that spreads the impact of higher bits
642	>	* downward. There is a tradeoff between speed, utility, and
643	>	* quality of bit-spreading. Because many common sets of hashes
644	>	* are already reasonably distributed (so don't benefit from
645	>	* spreading), and because we use trees to handle large sets of
646	>	* collisions in bins, we just XOR some shifted bits in the
647	>	* cheapest possible way to reduce systematic lossage, as well as
648	>	* to incorporate impact of the highest bits that would otherwise
649	>	* never be used in index calculations because of table bounds.
650	>	*/
651	>	static final int spread(int h) {
652	>	return (h ^ (h >>> 16)) & HASH_BITS;
653	>	}
654	>
655	>	/**
656	>	* Returns a power of two table size for the given desired capacity.
657	>	* See Hackers Delight, sec 3.2
658	>	*/
659	>	private static final int tableSizeFor(int c) {
660	>	int n = c - 1;
661	>	n |= n >>> 1;
662	>	n |= n >>> 2;
663	>	n |= n >>> 4;
664	>	n |= n >>> 8;
665	>	n |= n >>> 16;
666	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
667	>	}
668	>
669	>	/**
670	>	* Returns x's Class if it is of the form "class C implements
671	>	* Comparable<C>", else null.
672	>	*/
673	>	static Class<?> comparableClassFor(Object x) {
674	>	if (x instanceof Comparable) {
675	>	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
676	>	if ((c = x.getClass()) == String.class) // bypass checks
677	>	return c;
678	>	if ((ts = c.getGenericInterfaces()) != null) {
679	>	for (int i = 0; i < ts.length; ++i) {
680	>	if (((t = ts[i]) instanceof ParameterizedType) &&
681	>	((p = (ParameterizedType)t).getRawType() ==
682	>	Comparable.class) &&
683	>	(as = p.getActualTypeArguments()) != null &&
684	>	as.length == 1 && as[0] == c) // type arg is c
685	>	return c;
686	>	}
687		}
688		}
689	+	return null;
690		}
691
692		/**
693	<	* Gets the ith element of given table (if nonnull) with volatile
694	<	* read semantics. Note: This is manually integrated into a few
695	<	* performance-sensitive methods to reduce call overhead.
693	>	* Returns k.compareTo(x) if x matches kc (k's screened comparable
694	>	* class), else 0.
695	>	*/
696	>	@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
697	>	static int compareComparables(Class<?> kc, Object k, Object x) {
698	>	return (x == null || x.getClass() != kc ? 0 :
699	>	((Comparable)k).compareTo(x));
700	>	}
701	>
702	>	/* ---------------- Table element access -------------- */
703	>
704	>	/*
705	>	* Volatile access methods are used for table elements as well as
706	>	* elements of in-progress next table while resizing.  All uses of
707	>	* the tab arguments must be null checked by callers.  All callers
708	>	* also paranoically precheck that tab's length is not zero (or an
709	>	* equivalent check), thus ensuring that any index argument taking
710	>	* the form of a hash value anded with (length - 1) is a valid
711	>	* index.  Note that, to be correct wrt arbitrary concurrency
712	>	* errors by users, these checks must operate on local variables,
713	>	* which accounts for some odd-looking inline assignments below.
714	>	* Note that calls to setTabAt always occur within locked regions,
715	>	* and so in principle require only release ordering, not
716	>	* full volatile semantics, but are currently coded as volatile
717	>	* writes to be conservative.
718		*/
719	+
720		@SuppressWarnings("unchecked")
721	<	static final <K,V> HashEntry<K,V> entryAt(HashEntry<K,V>[] tab, int i) {
722	<	return (tab == null) ? null :
723	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
724	<	(tab, ((long)i << TSHIFT) + TBASE);
721	>	static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
722	>	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
723	>	}
724	>
725	>	static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
726	>	Node<K,V> c, Node<K,V> v) {
727	>	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
728	>	}
729	>
730	>	static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
731	>	U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
732		}
733
734	+	/* ---------------- Fields -------------- */
735	+
736	+	/**
737	+	* The array of bins. Lazily initialized upon first insertion.
738	+	* Size is always a power of two. Accessed directly by iterators.
739	+	*/
740	+	transient volatile Node<K,V>[] table;
741	+
742	+	/**
743	+	* The next table to use; non-null only while resizing.
744	+	*/
745	+	private transient volatile Node<K,V>[] nextTable;
746	+
747	+	/**
748	+	* Base counter value, used mainly when there is no contention,
749	+	* but also as a fallback during table initialization
750	+	* races. Updated via CAS.
751	+	*/
752	+	private transient volatile long baseCount;
753	+
754	+	/**
755	+	* Table initialization and resizing control.  When negative, the
756	+	* table is being initialized or resized: -1 for initialization,
757	+	* else -(1 + the number of active resizing threads).  Otherwise,
758	+	* when table is null, holds the initial table size to use upon
759	+	* creation, or 0 for default. After initialization, holds the
760	+	* next element count value upon which to resize the table.
761	+	*/
762	+	private transient volatile int sizeCtl;
763	+
764	+	/**
765	+	* The next table index (plus one) to split while resizing.
766	+	*/
767	+	private transient volatile int transferIndex;
768	+
769	+	/**
770	+	* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
771	+	*/
772	+	private transient volatile int cellsBusy;
773	+
774	+	/**
775	+	* Table of counter cells. When non-null, size is a power of 2.
776	+	*/
777	+	private transient volatile CounterCell[] counterCells;
778	+
779	+	// views
780	+	private transient KeySetView<K,V> keySet;
781	+	private transient ValuesView<K,V> values;
782	+	private transient EntrySetView<K,V> entrySet;
783	+
784	+
785	+	/* ---------------- Public operations -------------- */
786	+
787		/**
788	<	* Sets the ith element of given table, with volatile write
225	<	* semantics. (See above about use of putOrderedObject.)
788	>	* Creates a new, empty map with the default initial table size (16).
789		*/
790	<	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);
790	>	public ConcurrentHashMap() {
791		}
792
793		/**
794	<	* Applies a supplemental hash function to a given hashCode, which
795	<	* defends against poor quality hash functions.  This is critical
796	<	* because ConcurrentHashMap uses power-of-two length hash tables,
797	<	* that otherwise encounter collisions for hashCodes that do not
798	<	* differ in lower or upper bits.
794	>	* Creates a new, empty map with an initial table size
795	>	* accommodating the specified number of elements without the need
796	>	* to dynamically resize.
797	>	*
798	>	* @param initialCapacity The implementation performs internal
799	>	* sizing to accommodate this many elements.
800	>	* @throws IllegalArgumentException if the initial capacity of
801	>	* elements is negative
802		*/
803	<	private static int hash(int h) {
804	<	// Spread bits to regularize both segment and index locations,
805	<	// using variant of single-word Wang/Jenkins hash.
806	<	h += (h <<  15) ^ 0xffffcd7d;
807	<	h ^= (h >>> 10);
808	<	h += (h <<   3);
809	<	h ^= (h >>>  6);
246	<	h += (h <<   2) + (h << 14);
247	<	return h ^ (h >>> 16);
803	>	public ConcurrentHashMap(int initialCapacity) {
804	>	if (initialCapacity < 0)
805	>	throw new IllegalArgumentException();
806	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
807	>	MAXIMUM_CAPACITY :
808	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
809	>	this.sizeCtl = cap;
810		}
811
812		/**
813	<	* Segments are specialized versions of hash tables.  This
814	<	* subclasses from ReentrantLock opportunistically, just to
815	<	* simplify some locking and avoid separate construction.
813	>	* Creates a new map with the same mappings as the given map.
814	>	*
815	>	* @param m the map
816		*/
817	<	static final class Segment<K,V> extends ReentrantLock implements Serializable {
818	<	/*
819	<	* Segments maintain a table of entry lists that are always
820	<	* 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	<	*/
817	>	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
818	>	this.sizeCtl = DEFAULT_CAPACITY;
819	>	putAll(m);
820	>	}
821
822	<	private static final long serialVersionUID = 2249069246763182397L;
822	>	/**
823	>	* Creates a new, empty map with an initial table size based on
824	>	* the given number of elements ({@code initialCapacity}) and
825	>	* initial table density ({@code loadFactor}).
826	>	*
827	>	* @param initialCapacity the initial capacity. The implementation
828	>	* performs internal sizing to accommodate this many elements,
829	>	* given the specified load factor.
830	>	* @param loadFactor the load factor (table density) for
831	>	* establishing the initial table size
832	>	* @throws IllegalArgumentException if the initial capacity of
833	>	* elements is negative or the load factor is nonpositive
834	>	*
835	>	* @since 1.6
836	>	*/
837	>	public ConcurrentHashMap(int initialCapacity, float loadFactor) {
838	>	this(initialCapacity, loadFactor, 1);
839	>	}
840
841	<	/**
842	<	* The maximum number of times to tryLock in a prescan before
843	<	* possibly blocking on acquire in preparation for a locked
844	<	* segment operation. On multiprocessors, using a bounded
845	<	* number of retries maintains cache acquired while locating
846	<	* nodes.
847	<	*/
848	<	static final int MAX_SCAN_RETRIES =
849	<	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
841	>	/**
842	>	* Creates a new, empty map with an initial table size based on
843	>	* the given number of elements ({@code initialCapacity}), table
844	>	* density ({@code loadFactor}), and number of concurrently
845	>	* updating threads ({@code concurrencyLevel}).
846	>	*
847	>	* @param initialCapacity the initial capacity. The implementation
848	>	* performs internal sizing to accommodate this many elements,
849	>	* given the specified load factor.
850	>	* @param loadFactor the load factor (table density) for
851	>	* establishing the initial table size
852	>	* @param concurrencyLevel the estimated number of concurrently
853	>	* updating threads. The implementation may use this value as
854	>	* a sizing hint.
855	>	* @throws IllegalArgumentException if the initial capacity is
856	>	* negative or the load factor or concurrencyLevel are
857	>	* nonpositive
858	>	*/
859	>	public ConcurrentHashMap(int initialCapacity,
860	>	float loadFactor, int concurrencyLevel) {
861	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
862	>	throw new IllegalArgumentException();
863	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
864	>	initialCapacity = concurrencyLevel;   // as estimated threads
865	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
866	>	int cap = (size >= (long)MAXIMUM_CAPACITY) ?
867	>	MAXIMUM_CAPACITY : tableSizeFor((int)size);
868	>	this.sizeCtl = cap;
869	>	}
870
871	<	/**
295	<	* The per-segment table. Elements are accessed via
296	<	* entryAt/setEntryAt providing volatile semantics.
297	<	*/
298	<	transient volatile HashEntry<K,V>[] table;
871	>	// Original (since JDK1.2) Map methods
872
873	<	/**
874	<	* The number of elements. Accessed only either within locks
875	<	* or among other volatile reads that maintain visibility.
876	<	*/
877	<	transient int count;
873	>	/**
874	>	* {@inheritDoc}
875	>	*/
876	>	public int size() {
877	>	long n = sumCount();
878	>	return ((n < 0L) ? 0 :
879	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
880	>	(int)n);
881	>	}
882
883	<	/**
884	<	* The total number of mutative operations in this segment.
885	<	* Even though this may overflows 32 bits, it provides
886	<	* sufficient accuracy for stability checks in CHM isEmpty()
887	<	* and size() methods.  Accessed only either within locks or
888	<	* among other volatile reads that maintain visibility.
312	<	*/
313	<	transient int modCount;
883	>	/**
884	>	* {@inheritDoc}
885	>	*/
886	>	public boolean isEmpty() {
887	>	return sumCount() <= 0L; // ignore transient negative values
888	>	}
889
890	<	/**
891	<	* The table is rehashed when its size exceeds this threshold.
892	<	* (The value of this field is always <tt>(int)(capacity *
893	<	* loadFactor)</tt>.)
894	<	*/
895	<	transient int threshold;
890	>	/**
891	>	* Returns the value to which the specified key is mapped,
892	>	* or {@code null} if this map contains no mapping for the key.
893	>	*
894	>	* <p>More formally, if this map contains a mapping from a key
895	>	* {@code k} to a value {@code v} such that {@code key.equals(k)},
896	>	* then this method returns {@code v}; otherwise it returns
897	>	* {@code null}.  (There can be at most one such mapping.)
898	>	*
899	>	* @throws NullPointerException if the specified key is null
900	>	*/
901	>	public V get(Object key) {
902	>	Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
903	>	int h = spread(key.hashCode());
904	>	if ((tab = table) != null && (n = tab.length) > 0 &&
905	>	(e = tabAt(tab, (n - 1) & h)) != null) {
906	>	if ((eh = e.hash) == h) {
907	>	if ((ek = e.key) == key || (ek != null && key.equals(ek)))
908	>	return e.val;
909	>	}
910	>	else if (eh < 0)
911	>	return (p = e.find(h, key)) != null ? p.val : null;
912	>	while ((e = e.next) != null) {
913	>	if (e.hash == h &&
914	>	((ek = e.key) == key || (ek != null && key.equals(ek))))
915	>	return e.val;
916	>	}
917	>	}
918	>	return null;
919	>	}
920
921	<	/**
922	<	* The load factor for the hash table.  Even though this value
923	<	* is same for all segments, it is replicated to avoid needing
924	<	* links to outer object.
925	<	* @serial
926	<	*/
927	<	final float loadFactor;
921	>	/**
922	>	* Tests if the specified object is a key in this table.
923	>	*
924	>	* @param  key possible key
925	>	* @return {@code true} if and only if the specified object
926	>	*         is a key in this table, as determined by the
927	>	*         {@code equals} method; {@code false} otherwise
928	>	* @throws NullPointerException if the specified key is null
929	>	*/
930	>	public boolean containsKey(Object key) {
931	>	return get(key) != null;
932	>	}
933
934	<	Segment(float lf, int threshold, HashEntry<K,V>[] tab) {
935	<	this.loadFactor = lf;
936	<	this.threshold = threshold;
937	<	this.table = tab;
934	>	/**
935	>	* Returns {@code true} if this map maps one or more keys to the
936	>	* specified value. Note: This method may require a full traversal
937	>	* of the map, and is much slower than method {@code containsKey}.
938	>	*
939	>	* @param value value whose presence in this map is to be tested
940	>	* @return {@code true} if this map maps one or more keys to the
941	>	*         specified value
942	>	* @throws NullPointerException if the specified value is null
943	>	*/
944	>	public boolean containsValue(Object value) {
945	>	if (value == null)
946	>	throw new NullPointerException();
947	>	Node<K,V>[] t;
948	>	if ((t = table) != null) {
949	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
950	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
951	>	V v;
952	>	if ((v = p.val) == value || (v != null && value.equals(v)))
953	>	return true;
954	>	}
955		}
956	+	return false;
957	+	}
958
959	<	final V put(K key, int hash, V value, boolean onlyIfAbsent) {
960	<	HashEntry<K,V> node = tryLock() ? null :
961	<	scanAndLockForPut(key, hash, value);
962	<	V oldValue;
963	<	try {
964	<	HashEntry<K,V>[] tab = table;
965	<	int index = (tab.length - 1) & hash;
966	<	HashEntry<K,V> first = entryAt(tab, index);
967	<	for (HashEntry<K,V> e = first;;) {
968	<	if (e != null) {
969	<	K k;
970	<	if ((k = e.key) == key ||
971	<	(e.hash == hash && key.equals(k))) {
972	<	oldValue = e.value;
973	<	if (!onlyIfAbsent) {
974	<	e.value = value;
975	<	++modCount;
959	>	/**
960	>	* Maps the specified key to the specified value in this table.
961	>	* Neither the key nor the value can be null.
962	>	*
963	>	* <p>The value can be retrieved by calling the {@code get} method
964	>	* with a key that is equal to the original key.
965	>	*
966	>	* @param key key with which the specified value is to be associated
967	>	* @param value value to be associated with the specified key
968	>	* @return the previous value associated with {@code key}, or
969	>	*         {@code null} if there was no mapping for {@code key}
970	>	* @throws NullPointerException if the specified key or value is null
971	>	*/
972	>	public V put(K key, V value) {
973	>	return putVal(key, value, false);
974	>	}
975	>
976	>	/** Implementation for put and putIfAbsent */
977	>	final V putVal(K key, V value, boolean onlyIfAbsent) {
978	>	if (key == null || value == null) throw new NullPointerException();
979	>	int hash = spread(key.hashCode());
980	>	int binCount = 0;
981	>	for (Node<K,V>[] tab = table;;) {
982	>	Node<K,V> f; int n, i, fh;
983	>	if (tab == null || (n = tab.length) == 0)
984	>	tab = initTable();
985	>	else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
986	>	if (casTabAt(tab, i, null,
987	>	new Node<K,V>(hash, key, value, null)))
988	>	break;                   // no lock when adding to empty bin
989	>	}
990	>	else if ((fh = f.hash) == MOVED)
991	>	tab = helpTransfer(tab, f);
992	>	else {
993	>	V oldVal = null;
994	>	synchronized (f) {
995	>	if (tabAt(tab, i) == f) {
996	>	if (fh >= 0) {
997	>	binCount = 1;
998	>	for (Node<K,V> e = f;; ++binCount) {
999	>	K ek;
1000	>	if (e.hash == hash &&
1001	>	((ek = e.key) == key ||
1002	>	(ek != null && key.equals(ek)))) {
1003	>	oldVal = e.val;
1004	>	if (!onlyIfAbsent)
1005	>	e.val = value;
1006	>	break;
1007	>	}
1008	>	Node<K,V> pred = e;
1009	>	if ((e = e.next) == null) {
1010	>	pred.next = new Node<K,V>(hash, key,
1011	>	value, null);
1012	>	break;
1013	>	}
1014		}
354	–	break;
1015		}
1016	<	e = e.next;
1017	<	}
1018	<	else {
1019	<	if (node != null)
1020	<	node.setNext(first);
1021	<	else
1022	<	node = new HashEntry<K,V>(hash, key, value, first);
1023	<	int c = count + 1;
1024	<	if (c > threshold && tab.length < MAXIMUM_CAPACITY)
1025	<	rehash(node);
1026	<	else
1027	<	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;
1016	>	else if (f instanceof TreeBin) {
1017	>	Node<K,V> p;
1018	>	binCount = 2;
1019	>	if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
1020	>	value)) != null) {
1021	>	oldVal = p.val;
1022	>	if (!onlyIfAbsent)
1023	>	p.val = value;
1024	>	}
1025	>	}
1026	>	else if (f instanceof ReservationNode)
1027	>	throw new IllegalStateException("Recursive update");
1028		}
469	–	else if (key.equals(e.key))
470	–	retries = 0;
471	–	else
472	–	e = e.next;
1029		}
1030	<	else if (++retries > MAX_SCAN_RETRIES) {
1031	<	lock();
1030	>	if (binCount != 0) {
1031	>	if (binCount >= TREEIFY_THRESHOLD)
1032	>	treeifyBin(tab, i);
1033	>	if (oldVal != null)
1034	>	return oldVal;
1035		break;
1036		}
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	–	}
1037		}
1038		}
1039	+	addCount(1L, binCount);
1040	+	return null;
1041	+	}
1042
1043	<	/**
1044	<	* Remove; match on key only if value null, else match both.
1045	<	*/
1046	<	final V remove(Object key, int hash, Object value) {
1047	<	if (!tryLock())
1048	<	scanAndLock(key, hash);
1049	<	V oldValue = null;
1050	<	try {
1051	<	HashEntry<K,V>[] tab = table;
1052	<	int index = (tab.length - 1) & hash;
1053	<	HashEntry<K,V> e = entryAt(tab, index);
1054	<	HashEntry<K,V> pred = null;
1055	<	while (e != null) {
1056	<	K k;
1057	<	HashEntry<K,V> next = e.next;
1058	<	if ((k = e.key) == key ||
1059	<	(e.hash == hash && key.equals(k))) {
1060	<	V v = e.value;
1061	<	if (value == null || value == v || value.equals(v)) {
1062	<	if (pred == null)
1063	<	setEntryAt(tab, index, next);
1064	<	else
1065	<	pred.setNext(next);
1066	<	++modCount;
1067	<	--count;
1068	<	oldValue = v;
1043	>	/**
1044	>	* Copies all of the mappings from the specified map to this one.
1045	>	* These mappings replace any mappings that this map had for any of the
1046	>	* keys currently in the specified map.
1047	>	*
1048	>	* @param m mappings to be stored in this map
1049	>	*/
1050	>	public void putAll(Map<? extends K, ? extends V> m) {
1051	>	tryPresize(m.size());
1052	>	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
1053	>	putVal(e.getKey(), e.getValue(), false);
1054	>	}
1055	>
1056	>	/**
1057	>	* Removes the key (and its corresponding value) from this map.
1058	>	* This method does nothing if the key is not in the map.
1059	>	*
1060	>	* @param  key the key that needs to be removed
1061	>	* @return the previous value associated with {@code key}, or
1062	>	*         {@code null} if there was no mapping for {@code key}
1063	>	* @throws NullPointerException if the specified key is null
1064	>	*/
1065	>	public V remove(Object key) {
1066	>	return replaceNode(key, null, null);
1067	>	}
1068	>
1069	>	/**
1070	>	* Implementation for the four public remove/replace methods:
1071	>	* Replaces node value with v, conditional upon match of cv if
1072	>	* non-null.  If resulting value is null, delete.
1073	>	*/
1074	>	final V replaceNode(Object key, V value, Object cv) {
1075	>	int hash = spread(key.hashCode());
1076	>	for (Node<K,V>[] tab = table;;) {
1077	>	Node<K,V> f; int n, i, fh;
1078	>	if (tab == null || (n = tab.length) == 0 ||
1079	>	(f = tabAt(tab, i = (n - 1) & hash)) == null)
1080	>	break;
1081	>	else if ((fh = f.hash) == MOVED)
1082	>	tab = helpTransfer(tab, f);
1083	>	else {
1084	>	V oldVal = null;
1085	>	boolean validated = false;
1086	>	synchronized (f) {
1087	>	if (tabAt(tab, i) == f) {
1088	>	if (fh >= 0) {
1089	>	validated = true;
1090	>	for (Node<K,V> e = f, pred = null;;) {
1091	>	K ek;
1092	>	if (e.hash == hash &&
1093	>	((ek = e.key) == key ||
1094	>	(ek != null && key.equals(ek)))) {
1095	>	V ev = e.val;
1096	>	if (cv == null || cv == ev ||
1097	>	(ev != null && cv.equals(ev))) {
1098	>	oldVal = ev;
1099	>	if (value != null)
1100	>	e.val = value;
1101	>	else if (pred != null)
1102	>	pred.next = e.next;
1103	>	else
1104	>	setTabAt(tab, i, e.next);
1105	>	}
1106	>	break;
1107	>	}
1108	>	pred = e;
1109	>	if ((e = e.next) == null)
1110	>	break;
1111	>	}
1112		}
1113	<	break;
1113	>	else if (f instanceof TreeBin) {
1114	>	validated = true;
1115	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1116	>	TreeNode<K,V> r, p;
1117	>	if ((r = t.root) != null &&
1118	>	(p = r.findTreeNode(hash, key, null)) != null) {
1119	>	V pv = p.val;
1120	>	if (cv == null || cv == pv ||
1121	>	(pv != null && cv.equals(pv))) {
1122	>	oldVal = pv;
1123	>	if (value != null)
1124	>	p.val = value;
1125	>	else if (t.removeTreeNode(p))
1126	>	setTabAt(tab, i, untreeify(t.first));
1127	>	}
1128	>	}
1129	>	}
1130	>	else if (f instanceof ReservationNode)
1131	>	throw new IllegalStateException("Recursive update");
1132		}
548	–	pred = e;
549	–	e = next;
1133		}
1134	<	} finally {
1135	<	unlock();
1136	<	}
1137	<	return oldValue;
1138	<	}
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;
1134	>	if (validated) {
1135	>	if (oldVal != null) {
1136	>	if (value == null)
1137	>	addCount(-1L, -1);
1138	>	return oldVal;
1139		}
1140	+	break;
1141		}
575	–	} finally {
576	–	unlock();
1142		}
578	–	return replaced;
1143		}
1144	+	return null;
1145	+	}
1146
1147	<	final V replace(K key, int hash, V value) {
1148	<	if (!tryLock())
1149	<	scanAndLock(key, hash);
1150	<	V oldValue = null;
1151	<	try {
1152	<	HashEntry<K,V> e;
1153	<	for (e = entryForHash(this, hash); e != null; e = e.next) {
1154	<	K k;
1155	<	if ((k = e.key) == key ||
1156	<	(e.hash == hash && key.equals(k))) {
1157	<	oldValue = e.value;
1158	<	e.value = value;
1159	<	++modCount;
1160	<	break;
1147	>	/**
1148	>	* Removes all of the mappings from this map.
1149	>	*/
1150	>	public void clear() {
1151	>	long delta = 0L; // negative number of deletions
1152	>	int i = 0;
1153	>	Node<K,V>[] tab = table;
1154	>	while (tab != null && i < tab.length) {
1155	>	int fh;
1156	>	Node<K,V> f = tabAt(tab, i);
1157	>	if (f == null)
1158	>	++i;
1159	>	else if ((fh = f.hash) == MOVED) {
1160	>	tab = helpTransfer(tab, f);
1161	>	i = 0; // restart
1162	>	}
1163	>	else {
1164	>	synchronized (f) {
1165	>	if (tabAt(tab, i) == f) {
1166	>	Node<K,V> p = (fh >= 0 ? f :
1167	>	(f instanceof TreeBin) ?
1168	>	((TreeBin<K,V>)f).first : null);
1169	>	while (p != null) {
1170	>	--delta;
1171	>	p = p.next;
1172	>	}
1173	>	setTabAt(tab, i++, null);
1174		}
1175		}
597	–	} finally {
598	–	unlock();
1176		}
600	–	return oldValue;
1177		}
1178	+	if (delta != 0L)
1179	+	addCount(delta, -1);
1180	+	}
1181
1182	<	final void clear() {
1183	<	lock();
1184	<	try {
1185	<	HashEntry<K,V>[] tab = table;
1186	<	for (int i = 0; i < tab.length ; i++)
1187	<	setEntryAt(tab, i, null);
1188	<	++modCount;
1189	<	count = 0;
1190	<	} finally {
1191	<	unlock();
1192	<	}
1193	<	}
1182	>	/**
1183	>	* Returns a {@link Set} view of the keys contained in this map.
1184	>	* The set is backed by the map, so changes to the map are
1185	>	* reflected in the set, and vice-versa. The set supports element
1186	>	* removal, which removes the corresponding mapping from this map,
1187	>	* via the {@code Iterator.remove}, {@code Set.remove},
1188	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1189	>	* operations.  It does not support the {@code add} or
1190	>	* {@code addAll} operations.
1191	>	*
1192	>	* <p>The view's iterators and spliterators are
1193	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1194	>	*
1195	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1196	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1197	>	*
1198	>	* @return the set view
1199	>	*/
1200	>	public KeySetView<K,V> keySet() {
1201	>	KeySetView<K,V> ks;
1202	>	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1203		}
1204
1205	<	// Accessing segments
1205	>	/**
1206	>	* Returns a {@link Collection} view of the values contained in this map.
1207	>	* The collection is backed by the map, so changes to the map are
1208	>	* reflected in the collection, and vice-versa.  The collection
1209	>	* supports element removal, which removes the corresponding
1210	>	* mapping from this map, via the {@code Iterator.remove},
1211	>	* {@code Collection.remove}, {@code removeAll},
1212	>	* {@code retainAll}, and {@code clear} operations.  It does not
1213	>	* support the {@code add} or {@code addAll} operations.
1214	>	*
1215	>	* <p>The view's iterators and spliterators are
1216	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1217	>	*
1218	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1219	>	* and {@link Spliterator#NONNULL}.
1220	>	*
1221	>	* @return the collection view
1222	>	*/
1223	>	public Collection<V> values() {
1224	>	ValuesView<K,V> vs;
1225	>	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1226	>	}
1227
1228		/**
1229	<	* Gets the jth element of given segment array (if nonnull) with
1230	<	* volatile element access semantics via Unsafe. (The null check
1231	<	* can trigger harmlessly only during deserialization.) Note:
1232	<	* because each element of segments array is set only once (using
1233	<	* fully ordered writes), some performance-sensitive methods rely
1234	<	* on this method only as a recheck upon null reads.
1229	>	* Returns a {@link Set} view of the mappings contained in this map.
1230	>	* The set is backed by the map, so changes to the map are
1231	>	* reflected in the set, and vice-versa.  The set supports element
1232	>	* removal, which removes the corresponding mapping from the map,
1233	>	* via the {@code Iterator.remove}, {@code Set.remove},
1234	>	* {@code removeAll}, {@code retainAll}, and {@code clear}
1235	>	* operations.
1236	>	*
1237	>	* <p>The view's iterators and spliterators are
1238	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1239	>	*
1240	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1241	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1242	>	*
1243	>	* @return the set view
1244		*/
1245	<	@SuppressWarnings("unchecked")
1246	<	static final <K,V> Segment<K,V> segmentAt(Segment<K,V>[] ss, int j) {
1247	<	long u = (j << SSHIFT) + SBASE;
630	<	return ss == null ? null :
631	<	(Segment<K,V>) UNSAFE.getObjectVolatile(ss, u);
1245	>	public Set<Map.Entry<K,V>> entrySet() {
1246	>	EntrySetView<K,V> es;
1247	>	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1248		}
1249
1250		/**
1251	<	* Returns the segment for the given index, creating it and
1252	<	* recording in segment table (via CAS) if not already present.
1251	>	* Returns the hash code value for this {@link Map}, i.e.,
1252	>	* the sum of, for each key-value pair in the map,
1253	>	* {@code key.hashCode() ^ value.hashCode()}.
1254		*
1255	<	* @param k the index
639	<	* @return the segment
1255	>	* @return the hash code value for this map
1256		*/
1257	<	@SuppressWarnings("unchecked")
1258	<	private Segment<K,V> ensureSegment(int k) {
1259	<	final Segment<K,V>[] ss = this.segments;
1260	<	long u = (k << SSHIFT) + SBASE; // raw offset
1261	<	Segment<K,V> seg;
1262	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u)) == null) {
1263	<	Segment<K,V> proto = ss[0]; // use segment 0 as prototype
1264	<	int cap = proto.table.length;
1265	<	float lf = proto.loadFactor;
1266	<	int threshold = (int)(cap * lf);
1267	<	HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry<?,?>[cap];
1268	<	if ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1269	<	== null) { // recheck
1270	<	Segment<K,V> s = new Segment<K,V>(lf, threshold, tab);
1271	<	while ((seg = (Segment<K,V>)UNSAFE.getObjectVolatile(ss, u))
1272	<	== null) {
1273	<	if (UNSAFE.compareAndSwapObject(ss, u, null, seg = s))
1274	<	break;
1275	<	}
1257	>	public int hashCode() {
1258	>	int h = 0;
1259	>	Node<K,V>[] t;
1260	>	if ((t = table) != null) {
1261	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1262	>	for (Node<K,V> p; (p = it.advance()) != null; )
1263	>	h += p.key.hashCode() ^ p.val.hashCode();
1264	>	}
1265	>	return h;
1266	>	}
1267	>
1268	>	/**
1269	>	* Returns a string representation of this map.  The string
1270	>	* representation consists of a list of key-value mappings (in no
1271	>	* particular order) enclosed in braces ("{@code {}}").  Adjacent
1272	>	* mappings are separated by the characters {@code ", "} (comma
1273	>	* and space).  Each key-value mapping is rendered as the key
1274	>	* followed by an equals sign ("{@code =}") followed by the
1275	>	* associated value.
1276	>	*
1277	>	* @return a string representation of this map
1278	>	*/
1279	>	public String toString() {
1280	>	Node<K,V>[] t;
1281	>	int f = (t = table) == null ? 0 : t.length;
1282	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1283	>	StringBuilder sb = new StringBuilder();
1284	>	sb.append('{');
1285	>	Node<K,V> p;
1286	>	if ((p = it.advance()) != null) {
1287	>	for (;;) {
1288	>	K k = p.key;
1289	>	V v = p.val;
1290	>	sb.append(k == this ? "(this Map)" : k);
1291	>	sb.append('=');
1292	>	sb.append(v == this ? "(this Map)" : v);
1293	>	if ((p = it.advance()) == null)
1294	>	break;
1295	>	sb.append(',').append(' ');
1296		}
1297		}
1298	<	return seg;
1298	>	return sb.append('}').toString();
1299		}
1300
665	–	// Hash-based segment and entry accesses
666	–
1301		/**
1302	<	* Gets the segment for the given hash code.
1302	>	* Compares the specified object with this map for equality.
1303	>	* Returns {@code true} if the given object is a map with the same
1304	>	* mappings as this map.  This operation may return misleading
1305	>	* results if either map is concurrently modified during execution
1306	>	* of this method.
1307	>	*
1308	>	* @param o object to be compared for equality with this map
1309	>	* @return {@code true} if the specified object is equal to this map
1310		*/
1311	<	@SuppressWarnings("unchecked")
1312	<	private Segment<K,V> segmentForHash(int h) {
1313	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1314	<	return (Segment<K,V>) UNSAFE.getObjectVolatile(segments, u);
1311	>	public boolean equals(Object o) {
1312	>	if (o != this) {
1313	>	if (!(o instanceof Map))
1314	>	return false;
1315	>	Map<?,?> m = (Map<?,?>) o;
1316	>	Node<K,V>[] t;
1317	>	int f = (t = table) == null ? 0 : t.length;
1318	>	Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
1319	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1320	>	V val = p.val;
1321	>	Object v = m.get(p.key);
1322	>	if (v == null || (v != val && !v.equals(val)))
1323	>	return false;
1324	>	}
1325	>	for (Map.Entry<?,?> e : m.entrySet()) {
1326	>	Object mk, mv, v;
1327	>	if ((mk = e.getKey()) == null ||
1328	>	(mv = e.getValue()) == null ||
1329	>	(v = get(mk)) == null ||
1330	>	(mv != v && !mv.equals(v)))
1331	>	return false;
1332	>	}
1333	>	}
1334	>	return true;
1335		}
1336
1337		/**
1338	<	* Gets the table entry for the given segment and hash code.
1338	>	* Stripped-down version of helper class used in previous version,
1339	>	* declared for the sake of serialization compatibility
1340		*/
1341	<	@SuppressWarnings("unchecked")
1342	<	static final <K,V> HashEntry<K,V> entryForHash(Segment<K,V> seg, int h) {
1343	<	HashEntry<K,V>[] tab;
1344	<	return (seg == null || (tab = seg.table) == null) ? null :
683	<	(HashEntry<K,V>) UNSAFE.getObjectVolatile
684	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1341	>	static class Segment<K,V> extends ReentrantLock implements Serializable {
1342	>	private static final long serialVersionUID = 2249069246763182397L;
1343	>	final float loadFactor;
1344	>	Segment(float lf) { this.loadFactor = lf; }
1345		}
1346
687	–	/* ---------------- Public operations -------------- */
688	–
1347		/**
1348	<	* Creates a new, empty map with the specified initial
1349	<	* capacity, load factor and concurrency level.
1350	<	*
1351	<	* @param initialCapacity the initial capacity. The implementation
1352	<	* performs internal sizing to accommodate this many elements.
1353	<	* @param loadFactor  the load factor threshold, used to control resizing.
1354	<	* Resizing may be performed when the average number of elements per
1355	<	* 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.
1348	>	* Saves the state of the {@code ConcurrentHashMap} instance to a
1349	>	* stream (i.e., serializes it).
1350	>	* @param s the stream
1351	>	* @throws java.io.IOException if an I/O error occurs
1352	>	* @serialData
1353	>	* the key (Object) and value (Object)
1354	>	* for each key-value mapping, followed by a null pair.
1355	>	* The key-value mappings are emitted in no particular order.
1356		*/
1357	<	@SuppressWarnings("unchecked")
1358	<	public ConcurrentHashMap(int initialCapacity,
1359	<	float loadFactor, int concurrencyLevel) {
1360	<	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
1357	>	private void writeObject(java.io.ObjectOutputStream s)
1358	>	throws java.io.IOException {
1359	>	// For serialization compatibility
1360	>	// Emulate segment calculation from previous version of this class
1361		int sshift = 0;
1362		int ssize = 1;
1363	<	while (ssize < concurrencyLevel) {
1363	>	while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
1364		++sshift;
1365		ssize <<= 1;
1366		}
1367	<	this.segmentShift = 32 - sshift;
1368	<	this.segmentMask = ssize - 1;
1369	<	if (initialCapacity > MAXIMUM_CAPACITY)
1370	<	initialCapacity = MAXIMUM_CAPACITY;
1371	<	int c = initialCapacity / ssize;
1372	<	if (c * ssize < initialCapacity)
1373	<	++c;
1374	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
1375	<	while (cap < c)
1376	<	cap <<= 1;
1377	<	// create segments and segments[0]
1378	<	Segment<K,V> s0 =
1379	<	new Segment<K,V>(loadFactor, (int)(cap * loadFactor),
1380	<	(HashEntry<K,V>[])new HashEntry<?,?>[cap]);
1381	<	Segment<K,V>[] ss = (Segment<K,V>[])new Segment<?,?>[ssize];
1382	<	UNSAFE.putOrderedObject(ss, SBASE, s0); // ordered write of segments[0]
1383	<	this.segments = ss;
1367	>	int segmentShift = 32 - sshift;
1368	>	int segmentMask = ssize - 1;
1369	>	@SuppressWarnings("unchecked")
1370	>	Segment<K,V>[] segments = (Segment<K,V>[])
1371	>	new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1372	>	for (int i = 0; i < segments.length; ++i)
1373	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
1374	>	s.putFields().put("segments", segments);
1375	>	s.putFields().put("segmentShift", segmentShift);
1376	>	s.putFields().put("segmentMask", segmentMask);
1377	>	s.writeFields();
1378	>
1379	>	Node<K,V>[] t;
1380	>	if ((t = table) != null) {
1381	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1382	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1383	>	s.writeObject(p.key);
1384	>	s.writeObject(p.val);
1385	>	}
1386	>	}
1387	>	s.writeObject(null);
1388	>	s.writeObject(null);
1389	>	segments = null; // throw away
1390		}
1391
1392		/**
1393	<	* Creates a new, empty map with the specified initial capacity
1394	<	* and load factor and with the default concurrencyLevel (16).
1395	<	*
1396	<	* @param initialCapacity The implementation performs internal
1397	<	* sizing to accommodate this many elements.
1398	<	* @param loadFactor  the load factor threshold, used to control resizing.
1399	<	* Resizing may be performed when the average number of elements per
1400	<	* bin exceeds this threshold.
1401	<	* @throws IllegalArgumentException if the initial capacity of
1402	<	* elements is negative or the load factor is nonpositive
1393	>	* Reconstitutes the instance from a stream (that is, deserializes it).
1394	>	* @param s the stream
1395	>	* @throws ClassNotFoundException if the class of a serialized object
1396	>	*         could not be found
1397	>	* @throws java.io.IOException if an I/O error occurs
1398	>	*/
1399	>	private void readObject(java.io.ObjectInputStream s)
1400	>	throws java.io.IOException, ClassNotFoundException {
1401	>	/*
1402	>	* To improve performance in typical cases, we create nodes
1403	>	* while reading, then place in table once size is known.
1404	>	* However, we must also validate uniqueness and deal with
1405	>	* overpopulated bins while doing so, which requires
1406	>	* specialized versions of putVal mechanics.
1407	>	*/
1408	>	sizeCtl = -1; // force exclusion for table construction
1409	>	s.defaultReadObject();
1410	>	long size = 0L;
1411	>	Node<K,V> p = null;
1412	>	for (;;) {
1413	>	@SuppressWarnings("unchecked")
1414	>	K k = (K) s.readObject();
1415	>	@SuppressWarnings("unchecked")
1416	>	V v = (V) s.readObject();
1417	>	if (k != null && v != null) {
1418	>	p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1419	>	++size;
1420	>	}
1421	>	else
1422	>	break;
1423	>	}
1424	>	if (size == 0L)
1425	>	sizeCtl = 0;
1426	>	else {
1427	>	int n;
1428	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
1429	>	n = MAXIMUM_CAPACITY;
1430	>	else {
1431	>	int sz = (int)size;
1432	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
1433	>	}
1434	>	@SuppressWarnings("unchecked")
1435	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1436	>	int mask = n - 1;
1437	>	long added = 0L;
1438	>	while (p != null) {
1439	>	boolean insertAtFront;
1440	>	Node<K,V> next = p.next, first;
1441	>	int h = p.hash, j = h & mask;
1442	>	if ((first = tabAt(tab, j)) == null)
1443	>	insertAtFront = true;
1444	>	else {
1445	>	K k = p.key;
1446	>	if (first.hash < 0) {
1447	>	TreeBin<K,V> t = (TreeBin<K,V>)first;
1448	>	if (t.putTreeVal(h, k, p.val) == null)
1449	>	++added;
1450	>	insertAtFront = false;
1451	>	}
1452	>	else {
1453	>	int binCount = 0;
1454	>	insertAtFront = true;
1455	>	Node<K,V> q; K qk;
1456	>	for (q = first; q != null; q = q.next) {
1457	>	if (q.hash == h &&
1458	>	((qk = q.key) == k ||
1459	>	(qk != null && k.equals(qk)))) {
1460	>	insertAtFront = false;
1461	>	break;
1462	>	}
1463	>	++binCount;
1464	>	}
1465	>	if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
1466	>	insertAtFront = false;
1467	>	++added;
1468	>	p.next = first;
1469	>	TreeNode<K,V> hd = null, tl = null;
1470	>	for (q = p; q != null; q = q.next) {
1471	>	TreeNode<K,V> t = new TreeNode<K,V>
1472	>	(q.hash, q.key, q.val, null, null);
1473	>	if ((t.prev = tl) == null)
1474	>	hd = t;
1475	>	else
1476	>	tl.next = t;
1477	>	tl = t;
1478	>	}
1479	>	setTabAt(tab, j, new TreeBin<K,V>(hd));
1480	>	}
1481	>	}
1482	>	}
1483	>	if (insertAtFront) {
1484	>	++added;
1485	>	p.next = first;
1486	>	setTabAt(tab, j, p);
1487	>	}
1488	>	p = next;
1489	>	}
1490	>	table = tab;
1491	>	sizeCtl = n - (n >>> 2);
1492	>	baseCount = added;
1493	>	}
1494	>	}
1495	>
1496	>	// ConcurrentMap methods
1497	>
1498	>	/**
1499	>	* {@inheritDoc}
1500		*
1501	<	* @since 1.6
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(int initialCapacity, float loadFactor) {
1506	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1505	>	public V putIfAbsent(K key, V value) {
1506	>	return putVal(key, value, true);
1507		}
1508
1509		/**
1510	<	* Creates a new, empty map with the specified initial capacity,
758	<	* and with default load factor (0.75) and concurrencyLevel (16).
1510	>	* {@inheritDoc}
1511		*
1512	<	* @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.
1512	>	* @throws NullPointerException if the specified key is null
1513		*/
1514	<	public ConcurrentHashMap(int initialCapacity) {
1515	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1514	>	public boolean remove(Object key, Object value) {
1515	>	if (key == null)
1516	>	throw new NullPointerException();
1517	>	return value != null && replaceNode(key, null, value) != null;
1518		}
1519
1520		/**
1521	<	* Creates a new, empty map with a default initial capacity (16),
1522	<	* load factor (0.75) and concurrencyLevel (16).
1521	>	* {@inheritDoc}
1522	>	*
1523	>	* @throws NullPointerException if any of the arguments are null
1524		*/
1525	<	public ConcurrentHashMap() {
1526	<	this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1525	>	public boolean replace(K key, V oldValue, V newValue) {
1526	>	if (key == null || oldValue == null || newValue == null)
1527	>	throw new NullPointerException();
1528	>	return replaceNode(key, newValue, oldValue) != null;
1529		}
1530
1531		/**
1532	<	* 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).
1532	>	* {@inheritDoc}
1533		*
1534	<	* @param m the map
1534	>	* @return the previous value associated with the specified key,
1535	>	*         or {@code null} if there was no mapping for the key
1536	>	* @throws NullPointerException if the specified key or value is null
1537		*/
1538	<	public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
1539	<	this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
1540	<	DEFAULT_INITIAL_CAPACITY),
1541	<	DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
789	<	putAll(m);
1538	>	public V replace(K key, V value) {
1539	>	if (key == null || value == null)
1540	>	throw new NullPointerException();
1541	>	return replaceNode(key, value, null);
1542		}
1543
1544	+	// Overrides of JDK8+ Map extension method defaults
1545	+
1546		/**
1547	<	* Returns <tt>true</tt> if this map contains no key-value mappings.
1547	>	* Returns the value to which the specified key is mapped, or the
1548	>	* given default value if this map contains no mapping for the
1549	>	* key.
1550		*
1551	<	* @return <tt>true</tt> if this map contains no key-value mappings
1551	>	* @param key the key whose associated value is to be returned
1552	>	* @param defaultValue the value to return if this map contains
1553	>	* no mapping for the given key
1554	>	* @return the mapping for the key, if present; else the default value
1555	>	* @throws NullPointerException if the specified key is null
1556		*/
1557	<	public boolean isEmpty() {
1558	<	/*
1559	<	* Sum per-segment modCounts to avoid mis-reporting when
1560	<	* elements are concurrently added and removed in one segment
1561	<	* while checking another, in which case the table was never
1562	<	* actually empty at any point. (The sum ensures accuracy up
1563	<	* through at least 1<<31 per-segment modifications before
1564	<	* recheck.)  Methods size() and containsValue() use similar
1565	<	* constructions for stability checks.
1566	<	*/
1567	<	long sum = 0L;
1568	<	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;
1557	>	public V getOrDefault(Object key, V defaultValue) {
1558	>	V v;
1559	>	return (v = get(key)) == null ? defaultValue : v;
1560	>	}
1561	>
1562	>	public void forEach(BiConsumer<? super K, ? super V> action) {
1563	>	if (action == null) throw new NullPointerException();
1564	>	Node<K,V>[] t;
1565	>	if ((t = table) != null) {
1566	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1567	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1568	>	action.accept(p.key, p.val);
1569		}
1570		}
1571	<	if (sum != 0L) { // recheck unless no modifications
1572	<	for (int j = 0; j < segments.length; ++j) {
1573	<	Segment<K,V> seg = segmentAt(segments, j);
1574	<	if (seg != null) {
1575	<	if (seg.count != 0)
1576	<	return false;
1577	<	sum -= seg.modCount;
1571	>	}
1572	>
1573	>	public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1574	>	if (function == null) throw new NullPointerException();
1575	>	Node<K,V>[] t;
1576	>	if ((t = table) != null) {
1577	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1578	>	for (Node<K,V> p; (p = it.advance()) != null; ) {
1579	>	V oldValue = p.val;
1580	>	for (K key = p.key;;) {
1581	>	V newValue = function.apply(key, oldValue);
1582	>	if (newValue == null)
1583	>	throw new NullPointerException();
1584	>	if (replaceNode(key, newValue, oldValue) != null ||
1585	>	(oldValue = get(key)) == null)
1586	>	break;
1587		}
1588		}
826	–	if (sum != 0L)
827	–	return false;
1589		}
829	–	return true;
1590		}
1591
1592		/**
1593	<	* Returns the number of key-value mappings in this map.  If the
1594	<	* map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
1595	<	* <tt>Integer.MAX_VALUE</tt>.
1593	>	* If the specified key is not already associated with a value,
1594	>	* attempts to compute its value using the given mapping function
1595	>	* and enters it into this map unless {@code null}.  The entire
1596	>	* method invocation is performed atomically, so the function is
1597	>	* applied at most once per key.  Some attempted update operations
1598	>	* on this map by other threads may be blocked while computation
1599	>	* is in progress, so the computation should be short and simple,
1600	>	* and must not attempt to update any other mappings of this map.
1601		*
1602	<	* @return the number of key-value mappings in this map
1602	>	* @param key key with which the specified value is to be associated
1603	>	* @param mappingFunction the function to compute a value
1604	>	* @return the current (existing or computed) value associated with
1605	>	*         the specified key, or null if the computed value is null
1606	>	* @throws NullPointerException if the specified key or mappingFunction
1607	>	*         is null
1608	>	* @throws IllegalStateException if the computation detectably
1609	>	*         attempts a recursive update to this map that would
1610	>	*         otherwise never complete
1611	>	* @throws RuntimeException or Error if the mappingFunction does so,
1612	>	*         in which case the mapping is left unestablished
1613		*/
1614	<	public int size() {
1615	<	// Try a few times to get accurate count. On failure due to
1616	<	// continuous async changes in table, resort to locking.
1617	<	final Segment<K,V>[] segments = this.segments;
1618	<	final int segmentCount = segments.length;
1619	<
1620	<	long previousSum = 0L;
1621	<	for (int retries = -1; retries < RETRIES_BEFORE_LOCK; retries++) {
1622	<	long sum = 0L;    // sum of modCounts
1623	<	long size = 0L;
1624	<	for (int i = 0; i < segmentCount; i++) {
1625	<	Segment<K,V> segment = segmentAt(segments, i);
1626	<	if (segment != null) {
1627	<	sum += segment.modCount;
1628	<	size += segment.count;
1629	<	}
1630	<	}
1631	<	if (sum == previousSum)
1632	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1633	<	previousSum = sum;
1614	>	public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
1615	>	if (key == null || mappingFunction == null)
1616	>	throw new NullPointerException();
1617	>	int h = spread(key.hashCode());
1618	>	V val = null;
1619	>	int binCount = 0;
1620	>	for (Node<K,V>[] tab = table;;) {
1621	>	Node<K,V> f; int n, i, fh;
1622	>	if (tab == null || (n = tab.length) == 0)
1623	>	tab = initTable();
1624	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1625	>	Node<K,V> r = new ReservationNode<K,V>();
1626	>	synchronized (r) {
1627	>	if (casTabAt(tab, i, null, r)) {
1628	>	binCount = 1;
1629	>	Node<K,V> node = null;
1630	>	try {
1631	>	if ((val = mappingFunction.apply(key)) != null)
1632	>	node = new Node<K,V>(h, key, val, null);
1633	>	} finally {
1634	>	setTabAt(tab, i, node);
1635	>	}
1636	>	}
1637	>	}
1638	>	if (binCount != 0)
1639	>	break;
1640	>	}
1641	>	else if ((fh = f.hash) == MOVED)
1642	>	tab = helpTransfer(tab, f);
1643	>	else {
1644	>	boolean added = false;
1645	>	synchronized (f) {
1646	>	if (tabAt(tab, i) == f) {
1647	>	if (fh >= 0) {
1648	>	binCount = 1;
1649	>	for (Node<K,V> e = f;; ++binCount) {
1650	>	K ek; V ev;
1651	>	if (e.hash == h &&
1652	>	((ek = e.key) == key ||
1653	>	(ek != null && key.equals(ek)))) {
1654	>	val = e.val;
1655	>	break;
1656	>	}
1657	>	Node<K,V> pred = e;
1658	>	if ((e = e.next) == null) {
1659	>	if ((val = mappingFunction.apply(key)) != null) {
1660	>	if (pred.next != null)
1661	>	throw new IllegalStateException("Recursive update");
1662	>	added = true;
1663	>	pred.next = new Node<K,V>(h, key, val, null);
1664	>	}
1665	>	break;
1666	>	}
1667	>	}
1668	>	}
1669	>	else if (f instanceof TreeBin) {
1670	>	binCount = 2;
1671	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1672	>	TreeNode<K,V> r, p;
1673	>	if ((r = t.root) != null &&
1674	>	(p = r.findTreeNode(h, key, null)) != null)
1675	>	val = p.val;
1676	>	else if ((val = mappingFunction.apply(key)) != null) {
1677	>	added = true;
1678	>	t.putTreeVal(h, key, val);
1679	>	}
1680	>	}
1681	>	else if (f instanceof ReservationNode)
1682	>	throw new IllegalStateException("Recursive update");
1683	>	}
1684	>	}
1685	>	if (binCount != 0) {
1686	>	if (binCount >= TREEIFY_THRESHOLD)
1687	>	treeifyBin(tab, i);
1688	>	if (!added)
1689	>	return val;
1690	>	break;
1691	>	}
1692	>	}
1693		}
1694	<
1695	<	long size = 0L;
1696	<	for (int i = 0; i < segmentCount; i++) {
863	<	Segment<K,V> segment = ensureSegment(i);
864	<	segment.lock();
865	<	size += segment.count;
866	<	}
867	<	for (int i = 0; i < segmentCount; i++)
868	<	segments[i].unlock();
869	<	return ((size >>> 31) == 0) ? (int) size : Integer.MAX_VALUE;
1694	>	if (val != null)
1695	>	addCount(1L, binCount);
1696	>	return val;
1697		}
1698
1699		/**
1700	<	* Returns the value to which the specified key is mapped,
1701	<	* or {@code null} if this map contains no mapping for the key.
1702	<	*
1703	<	* <p>More formally, if this map contains a mapping from a key
1704	<	* {@code k} to a value {@code v} such that {@code key.equals(k)},
1705	<	* then this method returns {@code v}; otherwise it returns
1706	<	* {@code null}.  (There can be at most one such mapping.)
1700	>	* If the value for the specified key is present, attempts to
1701	>	* compute a new mapping given the key and its current mapped
1702	>	* value.  The entire method invocation is performed atomically.
1703	>	* Some attempted update operations on this map by other threads
1704	>	* may be blocked while computation is in progress, so the
1705	>	* computation should be short and simple, and must not attempt to
1706	>	* update any other mappings of this map.
1707		*
1708	<	* @throws NullPointerException if the specified key is null
1708	>	* @param key key with which a value may be associated
1709	>	* @param remappingFunction the function to compute a value
1710	>	* @return the new value associated with the specified key, or null if none
1711	>	* @throws NullPointerException if the specified key or remappingFunction
1712	>	*         is null
1713	>	* @throws IllegalStateException if the computation detectably
1714	>	*         attempts a recursive update to this map that would
1715	>	*         otherwise never complete
1716	>	* @throws RuntimeException or Error if the remappingFunction does so,
1717	>	*         in which case the mapping is unchanged
1718		*/
1719	<	public V get(Object key) {
1720	<	Segment<K,V> s; // manually integrate access methods to reduce overhead
1721	<	HashEntry<K,V>[] tab;
1722	<	int h = hash(key.hashCode());
1723	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1724	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1725	<	(tab = s.table) != null) {
1726	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1727	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1728	<	e != null; e = e.next) {
1729	<	K k;
1730	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1731	<	return e.value;
1719	>	public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1720	>	if (key == null || remappingFunction == null)
1721	>	throw new NullPointerException();
1722	>	int h = spread(key.hashCode());
1723	>	V val = null;
1724	>	int delta = 0;
1725	>	int binCount = 0;
1726	>	for (Node<K,V>[] tab = table;;) {
1727	>	Node<K,V> f; int n, i, fh;
1728	>	if (tab == null || (n = tab.length) == 0)
1729	>	tab = initTable();
1730	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
1731	>	break;
1732	>	else if ((fh = f.hash) == MOVED)
1733	>	tab = helpTransfer(tab, f);
1734	>	else {
1735	>	synchronized (f) {
1736	>	if (tabAt(tab, i) == f) {
1737	>	if (fh >= 0) {
1738	>	binCount = 1;
1739	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1740	>	K ek;
1741	>	if (e.hash == h &&
1742	>	((ek = e.key) == key ||
1743	>	(ek != null && key.equals(ek)))) {
1744	>	val = remappingFunction.apply(key, e.val);
1745	>	if (val != null)
1746	>	e.val = val;
1747	>	else {
1748	>	delta = -1;
1749	>	Node<K,V> en = e.next;
1750	>	if (pred != null)
1751	>	pred.next = en;
1752	>	else
1753	>	setTabAt(tab, i, en);
1754	>	}
1755	>	break;
1756	>	}
1757	>	pred = e;
1758	>	if ((e = e.next) == null)
1759	>	break;
1760	>	}
1761	>	}
1762	>	else if (f instanceof TreeBin) {
1763	>	binCount = 2;
1764	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1765	>	TreeNode<K,V> r, p;
1766	>	if ((r = t.root) != null &&
1767	>	(p = r.findTreeNode(h, key, null)) != null) {
1768	>	val = remappingFunction.apply(key, p.val);
1769	>	if (val != null)
1770	>	p.val = val;
1771	>	else {
1772	>	delta = -1;
1773	>	if (t.removeTreeNode(p))
1774	>	setTabAt(tab, i, untreeify(t.first));
1775	>	}
1776	>	}
1777	>	}
1778	>	else if (f instanceof ReservationNode)
1779	>	throw new IllegalStateException("Recursive update");
1780	>	}
1781	>	}
1782	>	if (binCount != 0)
1783	>	break;
1784		}
1785		}
1786	<	return null;
1786	>	if (delta != 0)
1787	>	addCount((long)delta, binCount);
1788	>	return val;
1789		}
1790
1791		/**
1792	<	* Tests if the specified object is a key in this table.
1792	>	* Attempts to compute a mapping for the specified key and its
1793	>	* current mapped value (or {@code null} if there is no current
1794	>	* mapping). The entire method invocation is performed atomically.
1795	>	* Some attempted update operations on this map by other threads
1796	>	* may be blocked while computation is in progress, so the
1797	>	* computation should be short and simple, and must not attempt to
1798	>	* update any other mappings of this Map.
1799		*
1800	<	* @param  key   possible key
1801	<	* @return <tt>true</tt> if and only if the specified object
1802	<	*         is a key in this table, as determined by the
1803	<	*         <tt>equals</tt> method; <tt>false</tt> otherwise.
1804	<	* @throws NullPointerException if the specified key is null
1805	<	*/
1806	<	@SuppressWarnings("unchecked")
1807	<	public boolean containsKey(Object key) {
1808	<	Segment<K,V> s; // same as get() except no need for volatile value read
1809	<	HashEntry<K,V>[] tab;
1810	<	int h = hash(key.hashCode());
1811	<	long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
1812	<	if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
1813	<	(tab = s.table) != null) {
1814	<	for (HashEntry<K,V> e = (HashEntry<K,V>) UNSAFE.getObjectVolatile
1815	<	(tab, ((long)(((tab.length - 1) & h)) << TSHIFT) + TBASE);
1816	<	e != null; e = e.next) {
1817	<	K k;
1818	<	if ((k = e.key) == key || (e.hash == h && key.equals(k)))
1819	<	return true;
1800	>	* @param key key with which the specified value is to be associated
1801	>	* @param remappingFunction the function to compute a value
1802	>	* @return the new value associated with the specified key, or null if none
1803	>	* @throws NullPointerException if the specified key or remappingFunction
1804	>	*         is null
1805	>	* @throws IllegalStateException if the computation detectably
1806	>	*         attempts a recursive update to this map that would
1807	>	*         otherwise never complete
1808	>	* @throws RuntimeException or Error if the remappingFunction does so,
1809	>	*         in which case the mapping is unchanged
1810	>	*/
1811	>	public V compute(K key,
1812	>	BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1813	>	if (key == null || remappingFunction == null)
1814	>	throw new NullPointerException();
1815	>	int h = spread(key.hashCode());
1816	>	V val = null;
1817	>	int delta = 0;
1818	>	int binCount = 0;
1819	>	for (Node<K,V>[] tab = table;;) {
1820	>	Node<K,V> f; int n, i, fh;
1821	>	if (tab == null || (n = tab.length) == 0)
1822	>	tab = initTable();
1823	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1824	>	Node<K,V> r = new ReservationNode<K,V>();
1825	>	synchronized (r) {
1826	>	if (casTabAt(tab, i, null, r)) {
1827	>	binCount = 1;
1828	>	Node<K,V> node = null;
1829	>	try {
1830	>	if ((val = remappingFunction.apply(key, null)) != null) {
1831	>	delta = 1;
1832	>	node = new Node<K,V>(h, key, val, null);
1833	>	}
1834	>	} finally {
1835	>	setTabAt(tab, i, node);
1836	>	}
1837	>	}
1838	>	}
1839	>	if (binCount != 0)
1840	>	break;
1841	>	}
1842	>	else if ((fh = f.hash) == MOVED)
1843	>	tab = helpTransfer(tab, f);
1844	>	else {
1845	>	synchronized (f) {
1846	>	if (tabAt(tab, i) == f) {
1847	>	if (fh >= 0) {
1848	>	binCount = 1;
1849	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1850	>	K ek;
1851	>	if (e.hash == h &&
1852	>	((ek = e.key) == key ||
1853	>	(ek != null && key.equals(ek)))) {
1854	>	val = remappingFunction.apply(key, e.val);
1855	>	if (val != null)
1856	>	e.val = val;
1857	>	else {
1858	>	delta = -1;
1859	>	Node<K,V> en = e.next;
1860	>	if (pred != null)
1861	>	pred.next = en;
1862	>	else
1863	>	setTabAt(tab, i, en);
1864	>	}
1865	>	break;
1866	>	}
1867	>	pred = e;
1868	>	if ((e = e.next) == null) {
1869	>	val = remappingFunction.apply(key, null);
1870	>	if (val != null) {
1871	>	if (pred.next != null)
1872	>	throw new IllegalStateException("Recursive update");
1873	>	delta = 1;
1874	>	pred.next =
1875	>	new Node<K,V>(h, key, val, null);
1876	>	}
1877	>	break;
1878	>	}
1879	>	}
1880	>	}
1881	>	else if (f instanceof TreeBin) {
1882	>	binCount = 1;
1883	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1884	>	TreeNode<K,V> r, p;
1885	>	if ((r = t.root) != null)
1886	>	p = r.findTreeNode(h, key, null);
1887	>	else
1888	>	p = null;
1889	>	V pv = (p == null) ? null : p.val;
1890	>	val = remappingFunction.apply(key, pv);
1891	>	if (val != null) {
1892	>	if (p != null)
1893	>	p.val = val;
1894	>	else {
1895	>	delta = 1;
1896	>	t.putTreeVal(h, key, val);
1897	>	}
1898	>	}
1899	>	else if (p != null) {
1900	>	delta = -1;
1901	>	if (t.removeTreeNode(p))
1902	>	setTabAt(tab, i, untreeify(t.first));
1903	>	}
1904	>	}
1905	>	else if (f instanceof ReservationNode)
1906	>	throw new IllegalStateException("Recursive update");
1907	>	}
1908	>	}
1909	>	if (binCount != 0) {
1910	>	if (binCount >= TREEIFY_THRESHOLD)
1911	>	treeifyBin(tab, i);
1912	>	break;
1913	>	}
1914		}
1915		}
1916	<	return false;
1916	>	if (delta != 0)
1917	>	addCount((long)delta, binCount);
1918	>	return val;
1919		}
1920
1921		/**
1922	<	* Returns <tt>true</tt> if this map maps one or more keys to the
1923	<	* specified value. Note: This method requires a full internal
1924	<	* traversal of the hash table, and so is much slower than
1925	<	* method <tt>containsKey</tt>.
1922	>	* If the specified key is not already associated with a
1923	>	* (non-null) value, associates it with the given value.
1924	>	* Otherwise, replaces the value with the results of the given
1925	>	* remapping function, or removes if {@code null}. The entire
1926	>	* method invocation is performed atomically.  Some attempted
1927	>	* update operations on this map by other threads may be blocked
1928	>	* while computation is in progress, so the computation should be
1929	>	* short and simple, and must not attempt to update any other
1930	>	* mappings of this Map.
1931		*
1932	<	* @param value value whose presence in this map is to be tested
1933	<	* @return <tt>true</tt> if this map maps one or more keys to the
1934	<	*         specified value
1935	<	* @throws NullPointerException if the specified value is null
1932	>	* @param key key with which the specified value is to be associated
1933	>	* @param value the value to use if absent
1934	>	* @param remappingFunction the function to recompute a value if present
1935	>	* @return the new value associated with the specified key, or null if none
1936	>	* @throws NullPointerException if the specified key or the
1937	>	*         remappingFunction is null
1938	>	* @throws RuntimeException or Error if the remappingFunction does so,
1939	>	*         in which case the mapping is unchanged
1940		*/
1941	<	public boolean containsValue(Object value) {
1942	<	// Same idea as size()
942	<	if (value == null)
1941	>	public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1942	>	if (key == null || value == null || remappingFunction == null)
1943		throw new NullPointerException();
1944	<	final Segment<K,V>[] segments = this.segments;
1945	<	long previousSum = 0L;
1946	<	int lockCount = 0;
1947	<	try {
1948	<	for (int retries = -1; ; retries++) {
1949	<	long sum = 0L;    // sum of modCounts
1950	<	for (int j = 0; j < segments.length; j++) {
1951	<	Segment<K,V> segment;
1952	<	if (retries == RETRIES_BEFORE_LOCK) {
1953	<	segment = ensureSegment(j);
1954	<	segment.lock();
1955	<	lockCount++;
1956	<	} else {
1957	<	segment = segmentAt(segments, j);
1958	<	if (segment == null)
1959	<	continue;
1960	<	}
1961	<	HashEntry<K,V>[] tab = segment.table;
1962	<	if (tab != null) {
1963	<	for (int i = 0 ; i < tab.length; i++) {
1964	<	HashEntry<K,V> e;
1965	<	for (e = entryAt(tab, i); e != null; e = e.next) {
1966	<	V v = e.value;
1967	<	if (v != null && value.equals(v))
1968	<	return true;
1944	>	int h = spread(key.hashCode());
1945	>	V val = null;
1946	>	int delta = 0;
1947	>	int binCount = 0;
1948	>	for (Node<K,V>[] tab = table;;) {
1949	>	Node<K,V> f; int n, i, fh;
1950	>	if (tab == null || (n = tab.length) == 0)
1951	>	tab = initTable();
1952	>	else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
1953	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
1954	>	delta = 1;
1955	>	val = value;
1956	>	break;
1957	>	}
1958	>	}
1959	>	else if ((fh = f.hash) == MOVED)
1960	>	tab = helpTransfer(tab, f);
1961	>	else {
1962	>	synchronized (f) {
1963	>	if (tabAt(tab, i) == f) {
1964	>	if (fh >= 0) {
1965	>	binCount = 1;
1966	>	for (Node<K,V> e = f, pred = null;; ++binCount) {
1967	>	K ek;
1968	>	if (e.hash == h &&
1969	>	((ek = e.key) == key ||
1970	>	(ek != null && key.equals(ek)))) {
1971	>	val = remappingFunction.apply(e.val, value);
1972	>	if (val != null)
1973	>	e.val = val;
1974	>	else {
1975	>	delta = -1;
1976	>	Node<K,V> en = e.next;
1977	>	if (pred != null)
1978	>	pred.next = en;
1979	>	else
1980	>	setTabAt(tab, i, en);
1981	>	}
1982	>	break;
1983	>	}
1984	>	pred = e;
1985	>	if ((e = e.next) == null) {
1986	>	delta = 1;
1987	>	val = value;
1988	>	pred.next =
1989	>	new Node<K,V>(h, key, val, null);
1990	>	break;
1991	>	}
1992		}
1993		}
1994	<	sum += segment.modCount;
1994	>	else if (f instanceof TreeBin) {
1995	>	binCount = 2;
1996	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
1997	>	TreeNode<K,V> r = t.root;
1998	>	TreeNode<K,V> p = (r == null) ? null :
1999	>	r.findTreeNode(h, key, null);
2000	>	val = (p == null) ? value :
2001	>	remappingFunction.apply(p.val, value);
2002	>	if (val != null) {
2003	>	if (p != null)
2004	>	p.val = val;
2005	>	else {
2006	>	delta = 1;
2007	>	t.putTreeVal(h, key, val);
2008	>	}
2009	>	}
2010	>	else if (p != null) {
2011	>	delta = -1;
2012	>	if (t.removeTreeNode(p))
2013	>	setTabAt(tab, i, untreeify(t.first));
2014	>	}
2015	>	}
2016	>	else if (f instanceof ReservationNode)
2017	>	throw new IllegalStateException("Recursive update");
2018		}
2019		}
2020	<	if ((retries >= 0 && sum == previousSum) || lockCount > 0)
2021	<	return false;
2022	<	previousSum = sum;
2020	>	if (binCount != 0) {
2021	>	if (binCount >= TREEIFY_THRESHOLD)
2022	>	treeifyBin(tab, i);
2023	>	break;
2024	>	}
2025		}
978	–	} finally {
979	–	for (int j = 0; j < lockCount; j++)
980	–	segments[j].unlock();
2026		}
2027	+	if (delta != 0)
2028	+	addCount((long)delta, binCount);
2029	+	return val;
2030		}
2031
2032	+	// Hashtable legacy methods
2033	+
2034		/**
2035		* Legacy method testing if some key maps into the specified value
2036	<	* in this table.  This method is identical in functionality to
2037	<	* {@link #containsValue}, and exists solely to ensure
2036	>	* in this table.
2037	>	*
2038	>	* @deprecated This method is identical in functionality to
2039	>	* {@link #containsValue(Object)}, and exists solely to ensure
2040		* full compatibility with class {@link java.util.Hashtable},
2041		* which supported this method prior to introduction of the
2042		* Java Collections framework.
2043		*
2044		* @param  value a value to search for
2045	<	* @return <tt>true</tt> if and only if some key maps to the
2046	<	*         <tt>value</tt> argument in this table as
2047	<	*         determined by the <tt>equals</tt> method;
2048	<	*         <tt>false</tt> otherwise
2045	>	* @return {@code true} if and only if some key maps to the
2046	>	*         {@code value} argument in this table as
2047	>	*         determined by the {@code equals} method;
2048	>	*         {@code false} otherwise
2049		* @throws NullPointerException if the specified value is null
2050		*/
2051	+	@Deprecated
2052		public boolean contains(Object value) {
2053		return containsValue(value);
2054		}
2055
2056		/**
2057	<	* Maps the specified key to the specified value in this table.
1005	<	* Neither the key nor the value can be null.
1006	<	*
1007	<	* <p> The value can be retrieved by calling the <tt>get</tt> method
1008	<	* with a key that is equal to the original key.
2057	>	* Returns an enumeration of the keys in this table.
2058		*
2059	<	* @param key key with which the specified value is to be associated
2060	<	* @param value value to be associated with the specified key
1012	<	* @return the previous value associated with <tt>key</tt>, or
1013	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1014	<	* @throws NullPointerException if the specified key or value is null
2059	>	* @return an enumeration of the keys in this table
2060	>	* @see #keySet()
2061		*/
2062	<	@SuppressWarnings("unchecked")
2063	<	public V put(K key, V value) {
2064	<	Segment<K,V> s;
2065	<	if (value == null)
1020	<	throw new NullPointerException();
1021	<	int hash = hash(key.hashCode());
1022	<	int j = (hash >>> segmentShift) & segmentMask;
1023	<	if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
1024	<	(segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
1025	<	s = ensureSegment(j);
1026	<	return s.put(key, hash, value, false);
2062	>	public Enumeration<K> keys() {
2063	>	Node<K,V>[] t;
2064	>	int f = (t = table) == null ? 0 : t.length;
2065	>	return new KeyIterator<K,V>(t, f, 0, f, this);
2066		}
2067
2068		/**
2069	<	* {@inheritDoc}
2069	>	* Returns an enumeration of the values in this table.
2070		*
2071	<	* @return the previous value associated with the specified key,
2072	<	*         or <tt>null</tt> if there was no mapping for the key
1034	<	* @throws NullPointerException if the specified key or value is null
2071	>	* @return an enumeration of the values in this table
2072	>	* @see #values()
2073		*/
2074	<	@SuppressWarnings("unchecked")
2075	<	public V putIfAbsent(K key, V value) {
2076	<	Segment<K,V> s;
2077	<	if (value == null)
1040	<	throw new NullPointerException();
1041	<	int hash = hash(key.hashCode());
1042	<	int j = (hash >>> segmentShift) & segmentMask;
1043	<	if ((s = (Segment<K,V>)UNSAFE.getObject
1044	<	(segments, (j << SSHIFT) + SBASE)) == null)
1045	<	s = ensureSegment(j);
1046	<	return s.put(key, hash, value, true);
2074	>	public Enumeration<V> elements() {
2075	>	Node<K,V>[] t;
2076	>	int f = (t = table) == null ? 0 : t.length;
2077	>	return new ValueIterator<K,V>(t, f, 0, f, this);
2078		}
2079
2080	+	// ConcurrentHashMap-only methods
2081	+
2082		/**
2083	<	* Copies all of the mappings from the specified map to this one.
2084	<	* These mappings replace any mappings that this map had for any of the
2085	<	* keys currently in the specified map.
2083	>	* Returns the number of mappings. This method should be used
2084	>	* instead of {@link #size} because a ConcurrentHashMap may
2085	>	* contain more mappings than can be represented as an int. The
2086	>	* value returned is an estimate; the actual count may differ if
2087	>	* there are concurrent insertions or removals.
2088		*
2089	<	* @param m mappings to be stored in this map
2089	>	* @return the number of mappings
2090	>	* @since 1.8
2091		*/
2092	<	public void putAll(Map<? extends K, ? extends V> m) {
2093	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
2094	<	put(e.getKey(), e.getValue());
2092	>	public long mappingCount() {
2093	>	long n = sumCount();
2094	>	return (n < 0L) ? 0L : n; // ignore transient negative values
2095		}
2096
2097		/**
2098	<	* Removes the key (and its corresponding value) from this map.
2099	<	* This method does nothing if the key is not in the map.
2098	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2099	>	* from the given type to {@code Boolean.TRUE}.
2100		*
2101	<	* @param  key the key that needs to be removed
2102	<	* @return the previous value associated with <tt>key</tt>, or
2103	<	*         <tt>null</tt> if there was no mapping for <tt>key</tt>
1068	<	* @throws NullPointerException if the specified key is null
2101	>	* @param <K> the element type of the returned set
2102	>	* @return the new set
2103	>	* @since 1.8
2104		*/
2105	<	public V remove(Object key) {
2106	<	int hash = hash(key.hashCode());
2107	<	Segment<K,V> s = segmentForHash(hash);
1073	<	return s == null ? null : s.remove(key, hash, null);
2105	>	public static <K> KeySetView<K,Boolean> newKeySet() {
2106	>	return new KeySetView<K,Boolean>
2107	>	(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
2108		}
2109
2110		/**
2111	<	* {@inheritDoc}
2111	>	* Creates a new {@link Set} backed by a ConcurrentHashMap
2112	>	* from the given type to {@code Boolean.TRUE}.
2113		*
2114	<	* @throws NullPointerException if the specified key is null
2114	>	* @param initialCapacity The implementation performs internal
2115	>	* sizing to accommodate this many elements.
2116	>	* @param <K> the element type of the returned set
2117	>	* @return the new set
2118	>	* @throws IllegalArgumentException if the initial capacity of
2119	>	* elements is negative
2120	>	* @since 1.8
2121		*/
2122	<	public boolean remove(Object key, Object value) {
2123	<	int hash = hash(key.hashCode());
2124	<	Segment<K,V> s;
1084	<	return value != null && (s = segmentForHash(hash)) != null &&
1085	<	s.remove(key, hash, value) != null;
2122	>	public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
2123	>	return new KeySetView<K,Boolean>
2124	>	(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
2125		}
2126
2127		/**
2128	<	* {@inheritDoc}
2128	>	* Returns a {@link Set} view of the keys in this map, using the
2129	>	* given common mapped value for any additions (i.e., {@link
2130	>	* Collection#add} and {@link Collection#addAll(Collection)}).
2131	>	* This is of course only appropriate if it is acceptable to use
2132	>	* the same value for all additions from this view.
2133		*
2134	<	* @throws NullPointerException if any of the arguments are null
2134	>	* @param mappedValue the mapped value to use for any additions
2135	>	* @return the set view
2136	>	* @throws NullPointerException if the mappedValue is null
2137		*/
2138	<	public boolean replace(K key, V oldValue, V newValue) {
2139	<	int hash = hash(key.hashCode());
1095	<	if (oldValue == null || newValue == null)
2138	>	public KeySetView<K,V> keySet(V mappedValue) {
2139	>	if (mappedValue == null)
2140		throw new NullPointerException();
2141	<	Segment<K,V> s = segmentForHash(hash);
1098	<	return s != null && s.replace(key, hash, oldValue, newValue);
2141	>	return new KeySetView<K,V>(this, mappedValue);
2142		}
2143
2144	+	/* ---------------- Special Nodes -------------- */
2145	+
2146		/**
2147	<	* {@inheritDoc}
1103	<	*
1104	<	* @return the previous value associated with the specified key,
1105	<	*         or <tt>null</tt> if there was no mapping for the key
1106	<	* @throws NullPointerException if the specified key or value is null
2147	>	* A node inserted at head of bins during transfer operations.
2148		*/
2149	<	public V replace(K key, V value) {
2150	<	int hash = hash(key.hashCode());
2151	<	if (value == null)
2152	<	throw new NullPointerException();
2153	<	Segment<K,V> s = segmentForHash(hash);
2154	<	return s == null ? null : s.replace(key, hash, value);
2149	>	static final class ForwardingNode<K,V> extends Node<K,V> {
2150	>	final Node<K,V>[] nextTable;
2151	>	ForwardingNode(Node<K,V>[] tab) {
2152	>	super(MOVED, null, null, null);
2153	>	this.nextTable = tab;
2154	>	}
2155	>
2156	>	Node<K,V> find(int h, Object k) {
2157	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2158	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2159	>	Node<K,V> e; int n;
2160	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2161	>	(e = tabAt(tab, (n - 1) & h)) == null)
2162	>	return null;
2163	>	for (;;) {
2164	>	int eh; K ek;
2165	>	if ((eh = e.hash) == h &&
2166	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2167	>	return e;
2168	>	if (eh < 0) {
2169	>	if (e instanceof ForwardingNode) {
2170	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2171	>	continue outer;
2172	>	}
2173	>	else
2174	>	return e.find(h, k);
2175	>	}
2176	>	if ((e = e.next) == null)
2177	>	return null;
2178	>	}
2179	>	}
2180	>	}
2181		}
2182
2183		/**
2184	<	* Removes all of the mappings from this map.
2184	>	* A place-holder node used in computeIfAbsent and compute
2185		*/
2186	<	public void clear() {
2187	<	final Segment<K,V>[] segments = this.segments;
2188	<	for (int j = 0; j < segments.length; ++j) {
2189	<	Segment<K,V> s = segmentAt(segments, j);
2190	<	if (s != null)
2191	<	s.clear();
2186	>	static final class ReservationNode<K,V> extends Node<K,V> {
2187	>	ReservationNode() {
2188	>	super(RESERVED, null, null, null);
2189	>	}
2190	>
2191	>	Node<K,V> find(int h, Object k) {
2192	>	return null;
2193		}
2194		}
2195
2196	+	/* ---------------- Table Initialization and Resizing -------------- */
2197	+
2198		/**
2199	<	* Returns a {@link Set} view of the keys contained in this map.
2200	<	* The set is backed by the map, so changes to the map are
2201	<	* reflected in the set, and vice-versa.  The set supports element
2202	<	* removal, which removes the corresponding mapping from this map,
2203	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
1134	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
1135	<	* operations.  It does not support the <tt>add</tt> or
1136	<	* <tt>addAll</tt> operations.
1137	<	*
1138	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1139	<	* that will never throw {@link ConcurrentModificationException},
1140	<	* and guarantees to traverse elements as they existed upon
1141	<	* construction of the iterator, and may (but is not guaranteed to)
1142	<	* reflect any modifications subsequent to construction.
1143	<	*/
1144	<	public Set<K> keySet() {
1145	<	Set<K> ks = keySet;
1146	<	return (ks != null) ? ks : (keySet = new KeySet());
2199	>	* Returns the stamp bits for resizing a table of size n.
2200	>	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2201	>	*/
2202	>	static final int resizeStamp(int n) {
2203	>	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2204		}
2205
2206		/**
2207	<	* Returns a {@link Collection} view of the values contained in this map.
1151	<	* The collection is backed by the map, so changes to the map are
1152	<	* reflected in the collection, and vice-versa.  The collection
1153	<	* supports element removal, which removes the corresponding
1154	<	* mapping from this map, via the <tt>Iterator.remove</tt>,
1155	<	* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
1156	<	* <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not
1157	<	* support the <tt>add</tt> or <tt>addAll</tt> operations.
1158	<	*
1159	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1160	<	* that will never throw {@link ConcurrentModificationException},
1161	<	* and guarantees to traverse elements as they existed upon
1162	<	* construction of the iterator, and may (but is not guaranteed to)
1163	<	* reflect any modifications subsequent to construction.
2207	>	* Initializes table, using the size recorded in sizeCtl.
2208		*/
2209	<	public Collection<V> values() {
2210	<	Collection<V> vs = values;
2211	<	return (vs != null) ? vs : (values = new Values());
2209	>	private final Node<K,V>[] initTable() {
2210	>	Node<K,V>[] tab; int sc;
2211	>	while ((tab = table) == null || tab.length == 0) {
2212	>	if ((sc = sizeCtl) < 0)
2213	>	Thread.yield(); // lost initialization race; just spin
2214	>	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2215	>	try {
2216	>	if ((tab = table) == null || tab.length == 0) {
2217	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2218	>	@SuppressWarnings("unchecked")
2219	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2220	>	table = tab = nt;
2221	>	sc = n - (n >>> 2);
2222	>	}
2223	>	} finally {
2224	>	sizeCtl = sc;
2225	>	}
2226	>	break;
2227	>	}
2228	>	}
2229	>	return tab;
2230		}
2231
2232		/**
2233	<	* Returns a {@link Set} view of the mappings contained in this map.
2234	<	* The set is backed by the map, so changes to the map are
2235	<	* reflected in the set, and vice-versa.  The set supports element
2236	<	* removal, which removes the corresponding mapping from the map,
2237	<	* via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
2238	<	* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
2239	<	* operations.  It does not support the <tt>add</tt> or
2240	<	* <tt>addAll</tt> operations.
1179	<	*
1180	<	* <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
1181	<	* that will never throw {@link ConcurrentModificationException},
1182	<	* and guarantees to traverse elements as they existed upon
1183	<	* construction of the iterator, and may (but is not guaranteed to)
1184	<	* reflect any modifications subsequent to construction.
2233	>	* Adds to count, and if table is too small and not already
2234	>	* resizing, initiates transfer. If already resizing, helps
2235	>	* perform transfer if work is available.  Rechecks occupancy
2236	>	* after a transfer to see if another resize is already needed
2237	>	* because resizings are lagging additions.
2238	>	*
2239	>	* @param x the count to add
2240	>	* @param check if <0, don't check resize, if <= 1 only check if uncontended
2241		*/
2242	<	public Set<Map.Entry<K,V>> entrySet() {
2243	<	Set<Map.Entry<K,V>> es = entrySet;
2244	<	return (es != null) ? es : (entrySet = new EntrySet());
2242	>	private final void addCount(long x, int check) {
2243	>	CounterCell[] as; long b, s;
2244	>	if ((as = counterCells) != null ||
2245	>	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2246	>	CounterCell a; long v; int m;
2247	>	boolean uncontended = true;
2248	>	if (as == null || (m = as.length - 1) < 0 ||
2249	>	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2250	>	!(uncontended =
2251	>	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2252	>	fullAddCount(x, uncontended);
2253	>	return;
2254	>	}
2255	>	if (check <= 1)
2256	>	return;
2257	>	s = sumCount();
2258	>	}
2259	>	if (check >= 0) {
2260	>	Node<K,V>[] tab, nt; int n, sc;
2261	>	while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2262	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2263	>	int rs = resizeStamp(n);
2264	>	if (sc < 0) {
2265	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2266	>	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2267	>	transferIndex <= 0)
2268	>	break;
2269	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
2270	>	transfer(tab, nt);
2271	>	}
2272	>	else if (U.compareAndSwapInt(this, SIZECTL, sc,
2273	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2274	>	transfer(tab, null);
2275	>	s = sumCount();
2276	>	}
2277	>	}
2278		}
2279
2280		/**
2281	<	* Returns an enumeration of the keys in this table.
1193	<	*
1194	<	* @return an enumeration of the keys in this table
1195	<	* @see #keySet()
2281	>	* Helps transfer if a resize is in progress.
2282		*/
2283	<	public Enumeration<K> keys() {
2284	<	return new KeyIterator();
2283	>	final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2284	>	Node<K,V>[] nextTab; int sc;
2285	>	if (tab != null && (f instanceof ForwardingNode) &&
2286	>	(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2287	>	int rs = resizeStamp(tab.length);
2288	>	while (nextTab == nextTable && table == tab &&
2289	>	(sc = sizeCtl) < 0) {
2290	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2291	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2292	>	break;
2293	>	if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
2294	>	transfer(tab, nextTab);
2295	>	break;
2296	>	}
2297	>	}
2298	>	return nextTab;
2299	>	}
2300	>	return table;
2301		}
2302
2303		/**
2304	<	* Returns an enumeration of the values in this table.
2304	>	* Tries to presize table to accommodate the given number of elements.
2305		*
2306	<	* @return an enumeration of the values in this table
1205	<	* @see #values()
2306	>	* @param size number of elements (doesn't need to be perfectly accurate)
2307		*/
2308	<	public Enumeration<V> elements() {
2309	<	return new ValueIterator();
2308	>	private final void tryPresize(int size) {
2309	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
2310	>	tableSizeFor(size + (size >>> 1) + 1);
2311	>	int sc;
2312	>	while ((sc = sizeCtl) >= 0) {
2313	>	Node<K,V>[] tab = table; int n;
2314	>	if (tab == null || (n = tab.length) == 0) {
2315	>	n = (sc > c) ? sc : c;
2316	>	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2317	>	try {
2318	>	if (table == tab) {
2319	>	@SuppressWarnings("unchecked")
2320	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2321	>	table = nt;
2322	>	sc = n - (n >>> 2);
2323	>	}
2324	>	} finally {
2325	>	sizeCtl = sc;
2326	>	}
2327	>	}
2328	>	}
2329	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
2330	>	break;
2331	>	else if (tab == table) {
2332	>	int rs = resizeStamp(n);
2333	>	if (U.compareAndSwapInt(this, SIZECTL, sc,
2334	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2335	>	transfer(tab, null);
2336	>	}
2337	>	}
2338		}
2339
2340	<	/* ---------------- Iterator Support -------------- */
2340	>	/**
2341	>	* Moves and/or copies the nodes in each bin to new table. See
2342	>	* above for explanation.
2343	>	*/
2344	>	private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
2345	>	int n = tab.length, stride;
2346	>	if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
2347	>	stride = MIN_TRANSFER_STRIDE; // subdivide range
2348	>	if (nextTab == null) {            // initiating
2349	>	try {
2350	>	@SuppressWarnings("unchecked")
2351	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2352	>	nextTab = nt;
2353	>	} catch (Throwable ex) {      // try to cope with OOME
2354	>	sizeCtl = Integer.MAX_VALUE;
2355	>	return;
2356	>	}
2357	>	nextTable = nextTab;
2358	>	transferIndex = n;
2359	>	}
2360	>	int nextn = nextTab.length;
2361	>	ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2362	>	boolean advance = true;
2363	>	boolean finishing = false; // to ensure sweep before committing nextTab
2364	>	for (int i = 0, bound = 0;;) {
2365	>	Node<K,V> f; int fh;
2366	>	while (advance) {
2367	>	int nextIndex, nextBound;
2368	>	if (--i >= bound || finishing)
2369	>	advance = false;
2370	>	else if ((nextIndex = transferIndex) <= 0) {
2371	>	i = -1;
2372	>	advance = false;
2373	>	}
2374	>	else if (U.compareAndSwapInt
2375	>	(this, TRANSFERINDEX, nextIndex,
2376	>	nextBound = (nextIndex > stride ?
2377	>	nextIndex - stride : 0))) {
2378	>	bound = nextBound;
2379	>	i = nextIndex - 1;
2380	>	advance = false;
2381	>	}
2382	>	}
2383	>	if (i < 0 || i >= n || i + n >= nextn) {
2384	>	int sc;
2385	>	if (finishing) {
2386	>	nextTable = null;
2387	>	table = nextTab;
2388	>	sizeCtl = (n << 1) - (n >>> 1);
2389	>	return;
2390	>	}
2391	>	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2392	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2393	>	return;
2394	>	finishing = advance = true;
2395	>	i = n; // recheck before commit
2396	>	}
2397	>	}
2398	>	else if ((f = tabAt(tab, i)) == null)
2399	>	advance = casTabAt(tab, i, null, fwd);
2400	>	else if ((fh = f.hash) == MOVED)
2401	>	advance = true; // already processed
2402	>	else {
2403	>	synchronized (f) {
2404	>	if (tabAt(tab, i) == f) {
2405	>	Node<K,V> ln, hn;
2406	>	if (fh >= 0) {
2407	>	int runBit = fh & n;
2408	>	Node<K,V> lastRun = f;
2409	>	for (Node<K,V> p = f.next; p != null; p = p.next) {
2410	>	int b = p.hash & n;
2411	>	if (b != runBit) {
2412	>	runBit = b;
2413	>	lastRun = p;
2414	>	}
2415	>	}
2416	>	if (runBit == 0) {
2417	>	ln = lastRun;
2418	>	hn = null;
2419	>	}
2420	>	else {
2421	>	hn = lastRun;
2422	>	ln = null;
2423	>	}
2424	>	for (Node<K,V> p = f; p != lastRun; p = p.next) {
2425	>	int ph = p.hash; K pk = p.key; V pv = p.val;
2426	>	if ((ph & n) == 0)
2427	>	ln = new Node<K,V>(ph, pk, pv, ln);
2428	>	else
2429	>	hn = new Node<K,V>(ph, pk, pv, hn);
2430	>	}
2431	>	setTabAt(nextTab, i, ln);
2432	>	setTabAt(nextTab, i + n, hn);
2433	>	setTabAt(tab, i, fwd);
2434	>	advance = true;
2435	>	}
2436	>	else if (f instanceof TreeBin) {
2437	>	TreeBin<K,V> t = (TreeBin<K,V>)f;
2438	>	TreeNode<K,V> lo = null, loTail = null;
2439	>	TreeNode<K,V> hi = null, hiTail = null;
2440	>	int lc = 0, hc = 0;
2441	>	for (Node<K,V> e = t.first; e != null; e = e.next) {
2442	>	int h = e.hash;
2443	>	TreeNode<K,V> p = new TreeNode<K,V>
2444	>	(h, e.key, e.val, null, null);
2445	>	if ((h & n) == 0) {
2446	>	if ((p.prev = loTail) == null)
2447	>	lo = p;
2448	>	else
2449	>	loTail.next = p;
2450	>	loTail = p;
2451	>	++lc;
2452	>	}
2453	>	else {
2454	>	if ((p.prev = hiTail) == null)
2455	>	hi = p;
2456	>	else
2457	>	hiTail.next = p;
2458	>	hiTail = p;
2459	>	++hc;
2460	>	}
2461	>	}
2462	>	ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
2463	>	(hc != 0) ? new TreeBin<K,V>(lo) : t;
2464	>	hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2465	>	(lc != 0) ? new TreeBin<K,V>(hi) : t;
2466	>	setTabAt(nextTab, i, ln);
2467	>	setTabAt(nextTab, i + n, hn);
2468	>	setTabAt(tab, i, fwd);
2469	>	advance = true;
2470	>	}
2471	>	}
2472	>	}
2473	>	}
2474	>	}
2475	>	}
2476
2477	<	abstract class HashIterator {
1214	<	int nextSegmentIndex;
1215	<	int nextTableIndex;
1216	<	HashEntry<K,V>[] currentTable;
1217	<	HashEntry<K, V> nextEntry;
1218	<	HashEntry<K, V> lastReturned;
2477	>	/* ---------------- Counter support -------------- */
2478
2479	<	HashIterator() {
2480	<	nextSegmentIndex = segments.length - 1;
2481	<	nextTableIndex = -1;
2482	<	advance();
2479	>	/**
2480	>	* A padded cell for distributing counts.  Adapted from LongAdder
2481	>	* and Striped64.  See their internal docs for explanation.
2482	>	*/
2483	>	@sun.misc.Contended static final class CounterCell {
2484	>	volatile long value;
2485	>	CounterCell(long x) { value = x; }
2486	>	}
2487	>
2488	>	final long sumCount() {
2489	>	CounterCell[] as = counterCells; CounterCell a;
2490	>	long sum = baseCount;
2491	>	if (as != null) {
2492	>	for (int i = 0; i < as.length; ++i) {
2493	>	if ((a = as[i]) != null)
2494	>	sum += a.value;
2495	>	}
2496	>	}
2497	>	return sum;
2498	>	}
2499	>
2500	>	// See LongAdder version for explanation
2501	>	private final void fullAddCount(long x, boolean wasUncontended) {
2502	>	int h;
2503	>	if ((h = ThreadLocalRandom.getProbe()) == 0) {
2504	>	ThreadLocalRandom.localInit();      // force initialization
2505	>	h = ThreadLocalRandom.getProbe();
2506	>	wasUncontended = true;
2507	>	}
2508	>	boolean collide = false;                // True if last slot nonempty
2509	>	for (;;) {
2510	>	CounterCell[] as; CounterCell a; int n; long v;
2511	>	if ((as = counterCells) != null && (n = as.length) > 0) {
2512	>	if ((a = as[(n - 1) & h]) == null) {
2513	>	if (cellsBusy == 0) {            // Try to attach new Cell
2514	>	CounterCell r = new CounterCell(x); // Optimistic create
2515	>	if (cellsBusy == 0 &&
2516	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2517	>	boolean created = false;
2518	>	try {               // Recheck under lock
2519	>	CounterCell[] rs; int m, j;
2520	>	if ((rs = counterCells) != null &&
2521	>	(m = rs.length) > 0 &&
2522	>	rs[j = (m - 1) & h] == null) {
2523	>	rs[j] = r;
2524	>	created = true;
2525	>	}
2526	>	} finally {
2527	>	cellsBusy = 0;
2528	>	}
2529	>	if (created)
2530	>	break;
2531	>	continue;           // Slot is now non-empty
2532	>	}
2533	>	}
2534	>	collide = false;
2535	>	}
2536	>	else if (!wasUncontended)       // CAS already known to fail
2537	>	wasUncontended = true;      // Continue after rehash
2538	>	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2539	>	break;
2540	>	else if (counterCells != as || n >= NCPU)
2541	>	collide = false;            // At max size or stale
2542	>	else if (!collide)
2543	>	collide = true;
2544	>	else if (cellsBusy == 0 &&
2545	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2546	>	try {
2547	>	if (counterCells == as) {// Expand table unless stale
2548	>	CounterCell[] rs = new CounterCell[n << 1];
2549	>	for (int i = 0; i < n; ++i)
2550	>	rs[i] = as[i];
2551	>	counterCells = rs;
2552	>	}
2553	>	} finally {
2554	>	cellsBusy = 0;
2555	>	}
2556	>	collide = false;
2557	>	continue;                   // Retry with expanded table
2558	>	}
2559	>	h = ThreadLocalRandom.advanceProbe(h);
2560	>	}
2561	>	else if (cellsBusy == 0 && counterCells == as &&
2562	>	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2563	>	boolean init = false;
2564	>	try {                           // Initialize table
2565	>	if (counterCells == as) {
2566	>	CounterCell[] rs = new CounterCell[2];
2567	>	rs[h & 1] = new CounterCell(x);
2568	>	counterCells = rs;
2569	>	init = true;
2570	>	}
2571	>	} finally {
2572	>	cellsBusy = 0;
2573	>	}
2574	>	if (init)
2575	>	break;
2576	>	}
2577	>	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2578	>	break;                          // Fall back on using base
2579	>	}
2580	>	}
2581	>
2582	>	/* ---------------- Conversion from/to TreeBins -------------- */
2583	>
2584	>	/**
2585	>	* Replaces all linked nodes in bin at given index unless table is
2586	>	* too small, in which case resizes instead.
2587	>	*/
2588	>	private final void treeifyBin(Node<K,V>[] tab, int index) {
2589	>	Node<K,V> b; int n, sc;
2590	>	if (tab != null) {
2591	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2592	>	tryPresize(n << 1);
2593	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2594	>	synchronized (b) {
2595	>	if (tabAt(tab, index) == b) {
2596	>	TreeNode<K,V> hd = null, tl = null;
2597	>	for (Node<K,V> e = b; e != null; e = e.next) {
2598	>	TreeNode<K,V> p =
2599	>	new TreeNode<K,V>(e.hash, e.key, e.val,
2600	>	null, null);
2601	>	if ((p.prev = tl) == null)
2602	>	hd = p;
2603	>	else
2604	>	tl.next = p;
2605	>	tl = p;
2606	>	}
2607	>	setTabAt(tab, index, new TreeBin<K,V>(hd));
2608	>	}
2609	>	}
2610	>	}
2611	>	}
2612	>	}
2613	>
2614	>	/**
2615	>	* Returns a list on non-TreeNodes replacing those in given list.
2616	>	*/
2617	>	static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2618	>	Node<K,V> hd = null, tl = null;
2619	>	for (Node<K,V> q = b; q != null; q = q.next) {
2620	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2621	>	if (tl == null)
2622	>	hd = p;
2623	>	else
2624	>	tl.next = p;
2625	>	tl = p;
2626	>	}
2627	>	return hd;
2628	>	}
2629	>
2630	>	/* ---------------- TreeNodes -------------- */
2631	>
2632	>	/**
2633	>	* Nodes for use in TreeBins
2634	>	*/
2635	>	static final class TreeNode<K,V> extends Node<K,V> {
2636	>	TreeNode<K,V> parent;  // red-black tree links
2637	>	TreeNode<K,V> left;
2638	>	TreeNode<K,V> right;
2639	>	TreeNode<K,V> prev;    // needed to unlink next upon deletion
2640	>	boolean red;
2641	>
2642	>	TreeNode(int hash, K key, V val, Node<K,V> next,
2643	>	TreeNode<K,V> parent) {
2644	>	super(hash, key, val, next);
2645	>	this.parent = parent;
2646	>	}
2647	>
2648	>	Node<K,V> find(int h, Object k) {
2649	>	return findTreeNode(h, k, null);
2650		}
2651
2652		/**
2653	<	* Sets nextEntry to first node of next non-empty table
2654	<	* (in backwards order, to simplify checks).
2653	>	* Returns the TreeNode (or null if not found) for the given key
2654	>	* starting at given root.
2655		*/
2656	<	final void advance() {
2657	<	for (;;) {
2658	<	if (nextTableIndex >= 0) {
2659	<	if ((nextEntry = entryAt(currentTable,
2660	<	nextTableIndex--)) != null)
2661	<	break;
2656	>	final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2657	>	if (k != null) {
2658	>	TreeNode<K,V> p = this;
2659	>	do {
2660	>	int ph, dir; K pk; TreeNode<K,V> q;
2661	>	TreeNode<K,V> pl = p.left, pr = p.right;
2662	>	if ((ph = p.hash) > h)
2663	>	p = pl;
2664	>	else if (ph < h)
2665	>	p = pr;
2666	>	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2667	>	return p;
2668	>	else if (pl == null)
2669	>	p = pr;
2670	>	else if (pr == null)
2671	>	p = pl;
2672	>	else if ((kc != null ||
2673	>	(kc = comparableClassFor(k)) != null) &&
2674	>	(dir = compareComparables(kc, k, pk)) != 0)
2675	>	p = (dir < 0) ? pl : pr;
2676	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2677	>	return q;
2678	>	else
2679	>	p = pl;
2680	>	} while (p != null);
2681	>	}
2682	>	return null;
2683	>	}
2684	>	}
2685	>
2686	>	/* ---------------- TreeBins -------------- */
2687	>
2688	>	/**
2689	>	* TreeNodes used at the heads of bins. TreeBins do not hold user
2690	>	* keys or values, but instead point to list of TreeNodes and
2691	>	* their root. They also maintain a parasitic read-write lock
2692	>	* forcing writers (who hold bin lock) to wait for readers (who do
2693	>	* not) to complete before tree restructuring operations.
2694	>	*/
2695	>	static final class TreeBin<K,V> extends Node<K,V> {
2696	>	TreeNode<K,V> root;
2697	>	volatile TreeNode<K,V> first;
2698	>	volatile Thread waiter;
2699	>	volatile int lockState;
2700	>	// values for lockState
2701	>	static final int WRITER = 1; // set while holding write lock
2702	>	static final int WAITER = 2; // set when waiting for write lock
2703	>	static final int READER = 4; // increment value for setting read lock
2704	>
2705	>	/**
2706	>	* Tie-breaking utility for ordering insertions when equal
2707	>	* hashCodes and non-comparable. We don't require a total
2708	>	* order, just a consistent insertion rule to maintain
2709	>	* equivalence across rebalancings. Tie-breaking further than
2710	>	* necessary simplifies testing a bit.
2711	>	*/
2712	>	static int tieBreakOrder(Object a, Object b) {
2713	>	int d;
2714	>	if (a == null || b == null ||
2715	>	(d = a.getClass().getName().
2716	>	compareTo(b.getClass().getName())) == 0)
2717	>	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2718	>	-1 : 1);
2719	>	return d;
2720	>	}
2721	>
2722	>	/**
2723	>	* Creates bin with initial set of nodes headed by b.
2724	>	*/
2725	>	TreeBin(TreeNode<K,V> b) {
2726	>	super(TREEBIN, null, null, null);
2727	>	this.first = b;
2728	>	TreeNode<K,V> r = null;
2729	>	for (TreeNode<K,V> x = b, next; x != null; x = next) {
2730	>	next = (TreeNode<K,V>)x.next;
2731	>	x.left = x.right = null;
2732	>	if (r == null) {
2733	>	x.parent = null;
2734	>	x.red = false;
2735	>	r = x;
2736		}
2737	<	else if (nextSegmentIndex >= 0) {
2738	<	Segment<K,V> seg = segmentAt(segments, nextSegmentIndex--);
2739	<	if (seg != null && (currentTable = seg.table) != null)
2740	<	nextTableIndex = currentTable.length - 1;
2737	>	else {
2738	>	K k = x.key;
2739	>	int h = x.hash;
2740	>	Class<?> kc = null;
2741	>	for (TreeNode<K,V> p = r;;) {
2742	>	int dir, ph;
2743	>	K pk = p.key;
2744	>	if ((ph = p.hash) > h)
2745	>	dir = -1;
2746	>	else if (ph < h)
2747	>	dir = 1;
2748	>	else if ((kc == null &&
2749	>	(kc = comparableClassFor(k)) == null) ||
2750	>	(dir = compareComparables(kc, k, pk)) == 0)
2751	>	dir = tieBreakOrder(k, pk);
2752	>	TreeNode<K,V> xp = p;
2753	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2754	>	x.parent = xp;
2755	>	if (dir <= 0)
2756	>	xp.left = x;
2757	>	else
2758	>	xp.right = x;
2759	>	r = balanceInsertion(r, x);
2760	>	break;
2761	>	}
2762	>	}
2763		}
2764	<	else
2764	>	}
2765	>	this.root = r;
2766	>	assert checkInvariants(root);
2767	>	}
2768	>
2769	>	/**
2770	>	* Acquires write lock for tree restructuring.
2771	>	*/
2772	>	private final void lockRoot() {
2773	>	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2774	>	contendedLock(); // offload to separate method
2775	>	}
2776	>
2777	>	/**
2778	>	* Releases write lock for tree restructuring.
2779	>	*/
2780	>	private final void unlockRoot() {
2781	>	lockState = 0;
2782	>	}
2783	>
2784	>	/**
2785	>	* Possibly blocks awaiting root lock.
2786	>	*/
2787	>	private final void contendedLock() {
2788	>	boolean waiting = false;
2789	>	for (int s;;) {
2790	>	if (((s = lockState) & ~WAITER) == 0) {
2791	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2792	>	if (waiting)
2793	>	waiter = null;
2794	>	return;
2795	>	}
2796	>	}
2797	>	else if ((s & WAITER) == 0) {
2798	>	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2799	>	waiting = true;
2800	>	waiter = Thread.currentThread();
2801	>	}
2802	>	}
2803	>	else if (waiting)
2804	>	LockSupport.park(this);
2805	>	}
2806	>	}
2807	>
2808	>	/**
2809	>	* Returns matching node or null if none. Tries to search
2810	>	* using tree comparisons from root, but continues linear
2811	>	* search when lock not available.
2812	>	*/
2813	>	final Node<K,V> find(int h, Object k) {
2814	>	if (k != null) {
2815	>	for (Node<K,V> e = first; e != null; ) {
2816	>	int s; K ek;
2817	>	if (((s = lockState) & (WAITER|WRITER)) != 0) {
2818	>	if (e.hash == h &&
2819	>	((ek = e.key) == k || (ek != null && k.equals(ek))))
2820	>	return e;
2821	>	e = e.next;
2822	>	}
2823	>	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2824	>	s + READER)) {
2825	>	TreeNode<K,V> r, p;
2826	>	try {
2827	>	p = ((r = root) == null ? null :
2828	>	r.findTreeNode(h, k, null));
2829	>	} finally {
2830	>	Thread w;
2831	>	if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
2832	>	(READER|WAITER) && (w = waiter) != null)
2833	>	LockSupport.unpark(w);
2834	>	}
2835	>	return p;
2836	>	}
2837	>	}
2838	>	}
2839	>	return null;
2840	>	}
2841	>
2842	>	/**
2843	>	* Finds or adds a node.
2844	>	* @return null if added
2845	>	*/
2846	>	final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2847	>	Class<?> kc = null;
2848	>	boolean searched = false;
2849	>	for (TreeNode<K,V> p = root;;) {
2850	>	int dir, ph; K pk;
2851	>	if (p == null) {
2852	>	first = root = new TreeNode<K,V>(h, k, v, null, null);
2853		break;
2854	+	}
2855	+	else if ((ph = p.hash) > h)
2856	+	dir = -1;
2857	+	else if (ph < h)
2858	+	dir = 1;
2859	+	else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2860	+	return p;
2861	+	else if ((kc == null &&
2862	+	(kc = comparableClassFor(k)) == null) ||
2863	+	(dir = compareComparables(kc, k, pk)) == 0) {
2864	+	if (!searched) {
2865	+	TreeNode<K,V> q, ch;
2866	+	searched = true;
2867	+	if (((ch = p.left) != null &&
2868	+	(q = ch.findTreeNode(h, k, kc)) != null) ||
2869	+	((ch = p.right) != null &&
2870	+	(q = ch.findTreeNode(h, k, kc)) != null))
2871	+	return q;
2872	+	}
2873	+	dir = tieBreakOrder(k, pk);
2874	+	}
2875	+
2876	+	TreeNode<K,V> xp = p;
2877	+	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2878	+	TreeNode<K,V> x, f = first;
2879	+	first = x = new TreeNode<K,V>(h, k, v, f, xp);
2880	+	if (f != null)
2881	+	f.prev = x;
2882	+	if (dir <= 0)
2883	+	xp.left = x;
2884	+	else
2885	+	xp.right = x;
2886	+	if (!xp.red)
2887	+	x.red = true;
2888	+	else {
2889	+	lockRoot();
2890	+	try {
2891	+	root = balanceInsertion(root, x);
2892	+	} finally {
2893	+	unlockRoot();
2894	+	}
2895	+	}
2896	+	break;
2897	+	}
2898		}
2899	+	assert checkInvariants(root);
2900	+	return null;
2901		}
2902
2903	<	final HashEntry<K,V> nextEntry() {
2904	<	HashEntry<K,V> e = nextEntry;
2905	<	if (e == null)
2906	<	throw new NoSuchElementException();
2907	<	lastReturned = e; // cannot assign until after null check
2908	<	if ((nextEntry = e.next) == null)
2909	<	advance();
2910	<	return e;
2903	>	/**
2904	>	* Removes the given node, that must be present before this
2905	>	* call.  This is messier than typical red-black deletion code
2906	>	* because we cannot swap the contents of an interior node
2907	>	* with a leaf successor that is pinned by "next" pointers
2908	>	* that are accessible independently of lock. So instead we
2909	>	* swap the tree linkages.
2910	>	*
2911	>	* @return true if now too small, so should be untreeified
2912	>	*/
2913	>	final boolean removeTreeNode(TreeNode<K,V> p) {
2914	>	TreeNode<K,V> next = (TreeNode<K,V>)p.next;
2915	>	TreeNode<K,V> pred = p.prev;  // unlink traversal pointers
2916	>	TreeNode<K,V> r, rl;
2917	>	if (pred == null)
2918	>	first = next;
2919	>	else
2920	>	pred.next = next;
2921	>	if (next != null)
2922	>	next.prev = pred;
2923	>	if (first == null) {
2924	>	root = null;
2925	>	return true;
2926	>	}
2927	>	if ((r = root) == null || r.right == null || // too small
2928	>	(rl = r.left) == null || rl.left == null)
2929	>	return true;
2930	>	lockRoot();
2931	>	try {
2932	>	TreeNode<K,V> replacement;
2933	>	TreeNode<K,V> pl = p.left;
2934	>	TreeNode<K,V> pr = p.right;
2935	>	if (pl != null && pr != null) {
2936	>	TreeNode<K,V> s = pr, sl;
2937	>	while ((sl = s.left) != null) // find successor
2938	>	s = sl;
2939	>	boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2940	>	TreeNode<K,V> sr = s.right;
2941	>	TreeNode<K,V> pp = p.parent;
2942	>	if (s == pr) { // p was s's direct parent
2943	>	p.parent = s;
2944	>	s.right = p;
2945	>	}
2946	>	else {
2947	>	TreeNode<K,V> sp = s.parent;
2948	>	if ((p.parent = sp) != null) {
2949	>	if (s == sp.left)
2950	>	sp.left = p;
2951	>	else
2952	>	sp.right = p;
2953	>	}
2954	>	if ((s.right = pr) != null)
2955	>	pr.parent = s;
2956	>	}
2957	>	p.left = null;
2958	>	if ((p.right = sr) != null)
2959	>	sr.parent = p;
2960	>	if ((s.left = pl) != null)
2961	>	pl.parent = s;
2962	>	if ((s.parent = pp) == null)
2963	>	r = s;
2964	>	else if (p == pp.left)
2965	>	pp.left = s;
2966	>	else
2967	>	pp.right = s;
2968	>	if (sr != null)
2969	>	replacement = sr;
2970	>	else
2971	>	replacement = p;
2972	>	}
2973	>	else if (pl != null)
2974	>	replacement = pl;
2975	>	else if (pr != null)
2976	>	replacement = pr;
2977	>	else
2978	>	replacement = p;
2979	>	if (replacement != p) {
2980	>	TreeNode<K,V> pp = replacement.parent = p.parent;
2981	>	if (pp == null)
2982	>	r = replacement;
2983	>	else if (p == pp.left)
2984	>	pp.left = replacement;
2985	>	else
2986	>	pp.right = replacement;
2987	>	p.left = p.right = p.parent = null;
2988	>	}
2989	>
2990	>	root = (p.red) ? r : balanceDeletion(r, replacement);
2991	>
2992	>	if (p == replacement) {  // detach pointers
2993	>	TreeNode<K,V> pp;
2994	>	if ((pp = p.parent) != null) {
2995	>	if (p == pp.left)
2996	>	pp.left = null;
2997	>	else if (p == pp.right)
2998	>	pp.right = null;
2999	>	p.parent = null;
3000	>	}
3001	>	}
3002	>	} finally {
3003	>	unlockRoot();
3004	>	}
3005	>	assert checkInvariants(root);
3006	>	return false;
3007	>	}
3008	>
3009	>	/* ------------------------------------------------------------ */
3010	>	// Red-black tree methods, all adapted from CLR
3011	>
3012	>	static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
3013	>	TreeNode<K,V> p) {
3014	>	TreeNode<K,V> r, pp, rl;
3015	>	if (p != null && (r = p.right) != null) {
3016	>	if ((rl = p.right = r.left) != null)
3017	>	rl.parent = p;
3018	>	if ((pp = r.parent = p.parent) == null)
3019	>	(root = r).red = false;
3020	>	else if (pp.left == p)
3021	>	pp.left = r;
3022	>	else
3023	>	pp.right = r;
3024	>	r.left = p;
3025	>	p.parent = r;
3026	>	}
3027	>	return root;
3028	>	}
3029	>
3030	>	static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
3031	>	TreeNode<K,V> p) {
3032	>	TreeNode<K,V> l, pp, lr;
3033	>	if (p != null && (l = p.left) != null) {
3034	>	if ((lr = p.left = l.right) != null)
3035	>	lr.parent = p;
3036	>	if ((pp = l.parent = p.parent) == null)
3037	>	(root = l).red = false;
3038	>	else if (pp.right == p)
3039	>	pp.right = l;
3040	>	else
3041	>	pp.left = l;
3042	>	l.right = p;
3043	>	p.parent = l;
3044	>	}
3045	>	return root;
3046	>	}
3047	>
3048	>	static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
3049	>	TreeNode<K,V> x) {
3050	>	x.red = true;
3051	>	for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
3052	>	if ((xp = x.parent) == null) {
3053	>	x.red = false;
3054	>	return x;
3055	>	}
3056	>	else if (!xp.red || (xpp = xp.parent) == null)
3057	>	return root;
3058	>	if (xp == (xppl = xpp.left)) {
3059	>	if ((xppr = xpp.right) != null && xppr.red) {
3060	>	xppr.red = false;
3061	>	xp.red = false;
3062	>	xpp.red = true;
3063	>	x = xpp;
3064	>	}
3065	>	else {
3066	>	if (x == xp.right) {
3067	>	root = rotateLeft(root, x = xp);
3068	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3069	>	}
3070	>	if (xp != null) {
3071	>	xp.red = false;
3072	>	if (xpp != null) {
3073	>	xpp.red = true;
3074	>	root = rotateRight(root, xpp);
3075	>	}
3076	>	}
3077	>	}
3078	>	}
3079	>	else {
3080	>	if (xppl != null && xppl.red) {
3081	>	xppl.red = false;
3082	>	xp.red = false;
3083	>	xpp.red = true;
3084	>	x = xpp;
3085	>	}
3086	>	else {
3087	>	if (x == xp.left) {
3088	>	root = rotateRight(root, x = xp);
3089	>	xpp = (xp = x.parent) == null ? null : xp.parent;
3090	>	}
3091	>	if (xp != null) {
3092	>	xp.red = false;
3093	>	if (xpp != null) {
3094	>	xpp.red = true;
3095	>	root = rotateLeft(root, xpp);
3096	>	}
3097	>	}
3098	>	}
3099	>	}
3100	>	}
3101	>	}
3102	>
3103	>	static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3104	>	TreeNode<K,V> x) {
3105	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3106	>	if (x == null || x == root)
3107	>	return root;
3108	>	else if ((xp = x.parent) == null) {
3109	>	x.red = false;
3110	>	return x;
3111	>	}
3112	>	else if (x.red) {
3113	>	x.red = false;
3114	>	return root;
3115	>	}
3116	>	else if ((xpl = xp.left) == x) {
3117	>	if ((xpr = xp.right) != null && xpr.red) {
3118	>	xpr.red = false;
3119	>	xp.red = true;
3120	>	root = rotateLeft(root, xp);
3121	>	xpr = (xp = x.parent) == null ? null : xp.right;
3122	>	}
3123	>	if (xpr == null)
3124	>	x = xp;
3125	>	else {
3126	>	TreeNode<K,V> sl = xpr.left, sr = xpr.right;
3127	>	if ((sr == null || !sr.red) &&
3128	>	(sl == null || !sl.red)) {
3129	>	xpr.red = true;
3130	>	x = xp;
3131	>	}
3132	>	else {
3133	>	if (sr == null || !sr.red) {
3134	>	if (sl != null)
3135	>	sl.red = false;
3136	>	xpr.red = true;
3137	>	root = rotateRight(root, xpr);
3138	>	xpr = (xp = x.parent) == null ?
3139	>	null : xp.right;
3140	>	}
3141	>	if (xpr != null) {
3142	>	xpr.red = (xp == null) ? false : xp.red;
3143	>	if ((sr = xpr.right) != null)
3144	>	sr.red = false;
3145	>	}
3146	>	if (xp != null) {
3147	>	xp.red = false;
3148	>	root = rotateLeft(root, xp);
3149	>	}
3150	>	x = root;
3151	>	}
3152	>	}
3153	>	}
3154	>	else { // symmetric
3155	>	if (xpl != null && xpl.red) {
3156	>	xpl.red = false;
3157	>	xp.red = true;
3158	>	root = rotateRight(root, xp);
3159	>	xpl = (xp = x.parent) == null ? null : xp.left;
3160	>	}
3161	>	if (xpl == null)
3162	>	x = xp;
3163	>	else {
3164	>	TreeNode<K,V> sl = xpl.left, sr = xpl.right;
3165	>	if ((sl == null || !sl.red) &&
3166	>	(sr == null || !sr.red)) {
3167	>	xpl.red = true;
3168	>	x = xp;
3169	>	}
3170	>	else {
3171	>	if (sl == null || !sl.red) {
3172	>	if (sr != null)
3173	>	sr.red = false;
3174	>	xpl.red = true;
3175	>	root = rotateLeft(root, xpl);
3176	>	xpl = (xp = x.parent) == null ?
3177	>	null : xp.left;
3178	>	}
3179	>	if (xpl != null) {
3180	>	xpl.red = (xp == null) ? false : xp.red;
3181	>	if ((sl = xpl.left) != null)
3182	>	sl.red = false;
3183	>	}
3184	>	if (xp != null) {
3185	>	xp.red = false;
3186	>	root = rotateRight(root, xp);
3187	>	}
3188	>	x = root;
3189	>	}
3190	>	}
3191	>	}
3192	>	}
3193		}
3194
3195	<	public final boolean hasNext() { return nextEntry != null; }
3196	<	public final boolean hasMoreElements() { return nextEntry != null; }
3195	>	/**
3196	>	* Recursive invariant check
3197	>	*/
3198	>	static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3199	>	TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
3200	>	tb = t.prev, tn = (TreeNode<K,V>)t.next;
3201	>	if (tb != null && tb.next != t)
3202	>	return false;
3203	>	if (tn != null && tn.prev != t)
3204	>	return false;
3205	>	if (tp != null && t != tp.left && t != tp.right)
3206	>	return false;
3207	>	if (tl != null && (tl.parent != t || tl.hash > t.hash))
3208	>	return false;
3209	>	if (tr != null && (tr.parent != t || tr.hash < t.hash))
3210	>	return false;
3211	>	if (t.red && tl != null && tl.red && tr != null && tr.red)
3212	>	return false;
3213	>	if (tl != null && !checkInvariants(tl))
3214	>	return false;
3215	>	if (tr != null && !checkInvariants(tr))
3216	>	return false;
3217	>	return true;
3218	>	}
3219	>
3220	>	private static final sun.misc.Unsafe U;
3221	>	private static final long LOCKSTATE;
3222	>	static {
3223	>	try {
3224	>	U = sun.misc.Unsafe.getUnsafe();
3225	>	Class<?> k = TreeBin.class;
3226	>	LOCKSTATE = U.objectFieldOffset
3227	>	(k.getDeclaredField("lockState"));
3228	>	} catch (ReflectiveOperationException e) {
3229	>	throw new Error(e);
3230	>	}
3231	>	}
3232	>	}
3233	>
3234	>	/* ----------------Table Traversal -------------- */
3235	>
3236	>	/**
3237	>	* Records the table, its length, and current traversal index for a
3238	>	* traverser that must process a region of a forwarded table before
3239	>	* proceeding with current table.
3240	>	*/
3241	>	static final class TableStack<K,V> {
3242	>	int length;
3243	>	int index;
3244	>	Node<K,V>[] tab;
3245	>	TableStack<K,V> next;
3246	>	}
3247	>
3248	>	/**
3249	>	* Encapsulates traversal for methods such as containsValue; also
3250	>	* serves as a base class for other iterators and spliterators.
3251	>	*
3252	>	* Method advance visits once each still-valid node that was
3253	>	* reachable upon iterator construction. It might miss some that
3254	>	* were added to a bin after the bin was visited, which is OK wrt
3255	>	* consistency guarantees. Maintaining this property in the face
3256	>	* of possible ongoing resizes requires a fair amount of
3257	>	* bookkeeping state that is difficult to optimize away amidst
3258	>	* volatile accesses.  Even so, traversal maintains reasonable
3259	>	* throughput.
3260	>	*
3261	>	* Normally, iteration proceeds bin-by-bin traversing lists.
3262	>	* However, if the table has been resized, then all future steps
3263	>	* must traverse both the bin at the current index as well as at
3264	>	* (index + baseSize); and so on for further resizings. To
3265	>	* paranoically cope with potential sharing by users of iterators
3266	>	* across threads, iteration terminates if a bounds checks fails
3267	>	* for a table read.
3268	>	*/
3269	>	static class Traverser<K,V> {
3270	>	Node<K,V>[] tab;        // current table; updated if resized
3271	>	Node<K,V> next;         // the next entry to use
3272	>	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3273	>	int index;              // index of bin to use next
3274	>	int baseIndex;          // current index of initial table
3275	>	int baseLimit;          // index bound for initial table
3276	>	final int baseSize;     // initial table size
3277	>
3278	>	Traverser(Node<K,V>[] tab, int size, int index, int limit) {
3279	>	this.tab = tab;
3280	>	this.baseSize = size;
3281	>	this.baseIndex = this.index = index;
3282	>	this.baseLimit = limit;
3283	>	this.next = null;
3284	>	}
3285	>
3286	>	/**
3287	>	* Advances if possible, returning next valid node, or null if none.
3288	>	*/
3289	>	final Node<K,V> advance() {
3290	>	Node<K,V> e;
3291	>	if ((e = next) != null)
3292	>	e = e.next;
3293	>	for (;;) {
3294	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3295	>	if (e != null)
3296	>	return next = e;
3297	>	if (baseIndex >= baseLimit || (t = tab) == null ||
3298	>	(n = t.length) <= (i = index) || i < 0)
3299	>	return next = null;
3300	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3301	>	if (e instanceof ForwardingNode) {
3302	>	tab = ((ForwardingNode<K,V>)e).nextTable;
3303	>	e = null;
3304	>	pushState(t, i, n);
3305	>	continue;
3306	>	}
3307	>	else if (e instanceof TreeBin)
3308	>	e = ((TreeBin<K,V>)e).first;
3309	>	else
3310	>	e = null;
3311	>	}
3312	>	if (stack != null)
3313	>	recoverState(n);
3314	>	else if ((index = i + baseSize) >= n)
3315	>	index = ++baseIndex; // visit upper slots if present
3316	>	}
3317	>	}
3318	>
3319	>	/**
3320	>	* Saves traversal state upon encountering a forwarding node.
3321	>	*/
3322	>	private void pushState(Node<K,V>[] t, int i, int n) {
3323	>	TableStack<K,V> s = spare;  // reuse if possible
3324	>	if (s != null)
3325	>	spare = s.next;
3326	>	else
3327	>	s = new TableStack<K,V>();
3328	>	s.tab = t;
3329	>	s.length = n;
3330	>	s.index = i;
3331	>	s.next = stack;
3332	>	stack = s;
3333	>	}
3334	>
3335	>	/**
3336	>	* Possibly pops traversal state.
3337	>	*
3338	>	* @param n length of current table
3339	>	*/
3340	>	private void recoverState(int n) {
3341	>	TableStack<K,V> s; int len;
3342	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3343	>	n = len;
3344	>	index = s.index;
3345	>	tab = s.tab;
3346	>	s.tab = null;
3347	>	TableStack<K,V> next = s.next;
3348	>	s.next = spare; // save for reuse
3349	>	stack = next;
3350	>	spare = s;
3351	>	}
3352	>	if (s == null && (index += baseSize) >= n)
3353	>	index = ++baseIndex;
3354	>	}
3355	>	}
3356	>
3357	>	/**
3358	>	* Base of key, value, and entry Iterators. Adds fields to
3359	>	* Traverser to support iterator.remove.
3360	>	*/
3361	>	static class BaseIterator<K,V> extends Traverser<K,V> {
3362	>	final ConcurrentHashMap<K,V> map;
3363	>	Node<K,V> lastReturned;
3364	>	BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
3365	>	ConcurrentHashMap<K,V> map) {
3366	>	super(tab, size, index, limit);
3367	>	this.map = map;
3368	>	advance();
3369	>	}
3370	>
3371	>	public final boolean hasNext() { return next != null; }
3372	>	public final boolean hasMoreElements() { return next != null; }
3373
3374		public final void remove() {
3375	<	if (lastReturned == null)
3375	>	Node<K,V> p;
3376	>	if ((p = lastReturned) == null)
3377		throw new IllegalStateException();
1263	–	ConcurrentHashMap.this.remove(lastReturned.key);
3378		lastReturned = null;
3379	+	map.replaceNode(p.key, null, null);
3380		}
3381		}
3382
3383	<	final class KeyIterator
3384	<	extends HashIterator
3385	<	implements Iterator<K>, Enumeration<K>
3386	<	{
3387	<	public final K next()        { return super.nextEntry().key; }
3388	<	public final K nextElement() { return super.nextEntry().key; }
3389	<	}
3390	<
3391	<	final class ValueIterator
3392	<	extends HashIterator
3393	<	implements Iterator<V>, Enumeration<V>
3394	<	{
3395	<	public final V next()        { return super.nextEntry().value; }
3396	<	public final V nextElement() { return super.nextEntry().value; }
3383	>	static final class KeyIterator<K,V> extends BaseIterator<K,V>
3384	>	implements Iterator<K>, Enumeration<K> {
3385	>	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3386	>	ConcurrentHashMap<K,V> map) {
3387	>	super(tab, index, size, limit, map);
3388	>	}
3389	>
3390	>	public final K next() {
3391	>	Node<K,V> p;
3392	>	if ((p = next) == null)
3393	>	throw new NoSuchElementException();
3394	>	K k = p.key;
3395	>	lastReturned = p;
3396	>	advance();
3397	>	return k;
3398	>	}
3399	>
3400	>	public final K nextElement() { return next(); }
3401	>	}
3402	>
3403	>	static final class ValueIterator<K,V> extends BaseIterator<K,V>
3404	>	implements Iterator<V>, Enumeration<V> {
3405	>	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3406	>	ConcurrentHashMap<K,V> map) {
3407	>	super(tab, index, size, limit, map);
3408	>	}
3409	>
3410	>	public final V next() {
3411	>	Node<K,V> p;
3412	>	if ((p = next) == null)
3413	>	throw new NoSuchElementException();
3414	>	V v = p.val;
3415	>	lastReturned = p;
3416	>	advance();
3417	>	return v;
3418	>	}
3419	>
3420	>	public final V nextElement() { return next(); }
3421	>	}
3422	>
3423	>	static final class EntryIterator<K,V> extends BaseIterator<K,V>
3424	>	implements Iterator<Map.Entry<K,V>> {
3425	>	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3426	>	ConcurrentHashMap<K,V> map) {
3427	>	super(tab, index, size, limit, map);
3428	>	}
3429	>
3430	>	public final Map.Entry<K,V> next() {
3431	>	Node<K,V> p;
3432	>	if ((p = next) == null)
3433	>	throw new NoSuchElementException();
3434	>	K k = p.key;
3435	>	V v = p.val;
3436	>	lastReturned = p;
3437	>	advance();
3438	>	return new MapEntry<K,V>(k, v, map);
3439	>	}
3440		}
3441
3442		/**
3443	<	* Custom Entry class used by EntryIterator.next(), that relays
3444	<	* setValue changes to the underlying map.
3445	<	*/
3446	<	final class WriteThroughEntry
3447	<	extends AbstractMap.SimpleEntry<K,V>
3448	<	{
3449	<	WriteThroughEntry(K k, V v) {
3450	<	super(k,v);
3443	>	* Exported Entry for EntryIterator
3444	>	*/
3445	>	static final class MapEntry<K,V> implements Map.Entry<K,V> {
3446	>	final K key; // non-null
3447	>	V val;       // non-null
3448	>	final ConcurrentHashMap<K,V> map;
3449	>	MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
3450	>	this.key = key;
3451	>	this.val = val;
3452	>	this.map = map;
3453	>	}
3454	>	public K getKey()        { return key; }
3455	>	public V getValue()      { return val; }
3456	>	public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3457	>	public String toString() { return key + "=" + val; }
3458	>
3459	>	public boolean equals(Object o) {
3460	>	Object k, v; Map.Entry<?,?> e;
3461	>	return ((o instanceof Map.Entry) &&
3462	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
3463	>	(v = e.getValue()) != null &&
3464	>	(k == key || k.equals(key)) &&
3465	>	(v == val || v.equals(val)));
3466		}
3467
3468		/**
3469		* Sets our entry's value and writes through to the map. The
3470	<	* value to return is somewhat arbitrary here. Since a
3471	<	* WriteThroughEntry does not necessarily track asynchronous
3472	<	* changes, the most recent "previous" value could be
3473	<	* different from what we return (or could even have been
3474	<	* removed in which case the put will re-establish). We do not
1302	<	* and cannot guarantee more.
3470	>	* value to return is somewhat arbitrary here. Since we do not
3471	>	* necessarily track asynchronous changes, the most recent
3472	>	* "previous" value could be different from what we return (or
3473	>	* could even have been removed, in which case the put will
3474	>	* re-establish). We do not and cannot guarantee more.
3475		*/
3476		public V setValue(V value) {
3477		if (value == null) throw new NullPointerException();
3478	<	V v = super.setValue(value);
3479	<	ConcurrentHashMap.this.put(getKey(), value);
3478	>	V v = val;
3479	>	val = value;
3480	>	map.put(key, value);
3481		return v;
3482		}
3483		}
3484
3485	<	final class EntryIterator
3486	<	extends HashIterator
3487	<	implements Iterator<Entry<K,V>>
3488	<	{
3489	<	public Map.Entry<K,V> next() {
3490	<	HashEntry<K,V> e = super.nextEntry();
3491	<	return new WriteThroughEntry(e.key, e.value);
3485	>	static final class KeySpliterator<K,V> extends Traverser<K,V>
3486	>	implements Spliterator<K> {
3487	>	long est;               // size estimate
3488	>	KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3489	>	long est) {
3490	>	super(tab, size, index, limit);
3491	>	this.est = est;
3492	>	}
3493	>
3494	>	public Spliterator<K> trySplit() {
3495	>	int i, f, h;
3496	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3497	>	new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
3498	>	f, est >>>= 1);
3499	>	}
3500	>
3501	>	public void forEachRemaining(Consumer<? super K> action) {
3502	>	if (action == null) throw new NullPointerException();
3503	>	for (Node<K,V> p; (p = advance()) != null;)
3504	>	action.accept(p.key);
3505	>	}
3506	>
3507	>	public boolean tryAdvance(Consumer<? super K> action) {
3508	>	if (action == null) throw new NullPointerException();
3509	>	Node<K,V> p;
3510	>	if ((p = advance()) == null)
3511	>	return false;
3512	>	action.accept(p.key);
3513	>	return true;
3514	>	}
3515	>
3516	>	public long estimateSize() { return est; }
3517	>
3518	>	public int characteristics() {
3519	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3520	>	Spliterator.NONNULL;
3521		}
3522		}
3523
3524	<	final class KeySet extends AbstractSet<K> {
3525	<	public Iterator<K> iterator() {
3526	<	return new KeyIterator();
3524	>	static final class ValueSpliterator<K,V> extends Traverser<K,V>
3525	>	implements Spliterator<V> {
3526	>	long est;               // size estimate
3527	>	ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
3528	>	long est) {
3529	>	super(tab, size, index, limit);
3530	>	this.est = est;
3531		}
3532	<	public int size() {
3533	<	return ConcurrentHashMap.this.size();
3532	>
3533	>	public Spliterator<V> trySplit() {
3534	>	int i, f, h;
3535	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3536	>	new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
3537	>	f, est >>>= 1);
3538		}
3539	<	public boolean isEmpty() {
3540	<	return ConcurrentHashMap.this.isEmpty();
3539	>
3540	>	public void forEachRemaining(Consumer<? super V> action) {
3541	>	if (action == null) throw new NullPointerException();
3542	>	for (Node<K,V> p; (p = advance()) != null;)
3543	>	action.accept(p.val);
3544		}
3545	<	public boolean contains(Object o) {
3546	<	return ConcurrentHashMap.this.containsKey(o);
3545	>
3546	>	public boolean tryAdvance(Consumer<? super V> action) {
3547	>	if (action == null) throw new NullPointerException();
3548	>	Node<K,V> p;
3549	>	if ((p = advance()) == null)
3550	>	return false;
3551	>	action.accept(p.val);
3552	>	return true;
3553		}
3554	<	public boolean remove(Object o) {
3555	<	return ConcurrentHashMap.this.remove(o) != null;
3554	>
3555	>	public long estimateSize() { return est; }
3556	>
3557	>	public int characteristics() {
3558	>	return Spliterator.CONCURRENT | Spliterator.NONNULL;
3559	>	}
3560	>	}
3561	>
3562	>	static final class EntrySpliterator<K,V> extends Traverser<K,V>
3563	>	implements Spliterator<Map.Entry<K,V>> {
3564	>	final ConcurrentHashMap<K,V> map; // To export MapEntry
3565	>	long est;               // size estimate
3566	>	EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
3567	>	long est, ConcurrentHashMap<K,V> map) {
3568	>	super(tab, size, index, limit);
3569	>	this.map = map;
3570	>	this.est = est;
3571	>	}
3572	>
3573	>	public Spliterator<Map.Entry<K,V>> trySplit() {
3574	>	int i, f, h;
3575	>	return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3576	>	new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
3577	>	f, est >>>= 1, map);
3578	>	}
3579	>
3580	>	public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
3581	>	if (action == null) throw new NullPointerException();
3582	>	for (Node<K,V> p; (p = advance()) != null; )
3583	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3584	>	}
3585	>
3586	>	public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
3587	>	if (action == null) throw new NullPointerException();
3588	>	Node<K,V> p;
3589	>	if ((p = advance()) == null)
3590	>	return false;
3591	>	action.accept(new MapEntry<K,V>(p.key, p.val, map));
3592	>	return true;
3593	>	}
3594	>
3595	>	public long estimateSize() { return est; }
3596	>
3597	>	public int characteristics() {
3598	>	return Spliterator.DISTINCT | Spliterator.CONCURRENT |
3599	>	Spliterator.NONNULL;
3600	>	}
3601	>	}
3602	>
3603	>	// Parallel bulk operations
3604	>
3605	>	/**
3606	>	* Computes initial batch value for bulk tasks. The returned value
3607	>	* is approximately exp2 of the number of times (minus one) to
3608	>	* split task by two before executing leaf action. This value is
3609	>	* faster to compute and more convenient to use as a guide to
3610	>	* splitting than is the depth, since it is used while dividing by
3611	>	* two anyway.
3612	>	*/
3613	>	final int batchFor(long b) {
3614	>	long n;
3615	>	if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
3616	>	return 0;
3617	>	int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
3618	>	return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
3619	>	}
3620	>
3621	>	/**
3622	>	* Performs the given action for each (key, value).
3623	>	*
3624	>	* @param parallelismThreshold the (estimated) number of elements
3625	>	* needed for this operation to be executed in parallel
3626	>	* @param action the action
3627	>	* @since 1.8
3628	>	*/
3629	>	public void forEach(long parallelismThreshold,
3630	>	BiConsumer<? super K,? super V> action) {
3631	>	if (action == null) throw new NullPointerException();
3632	>	new ForEachMappingTask<K,V>
3633	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3634	>	action).invoke();
3635	>	}
3636	>
3637	>	/**
3638	>	* Performs the given action for each non-null transformation
3639	>	* of each (key, value).
3640	>	*
3641	>	* @param parallelismThreshold the (estimated) number of elements
3642	>	* needed for this operation to be executed in parallel
3643	>	* @param transformer a function returning the transformation
3644	>	* for an element, or null if there is no transformation (in
3645	>	* which case the action is not applied)
3646	>	* @param action the action
3647	>	* @param <U> the return type of the transformer
3648	>	* @since 1.8
3649	>	*/
3650	>	public <U> void forEach(long parallelismThreshold,
3651	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3652	>	Consumer<? super U> action) {
3653	>	if (transformer == null || action == null)
3654	>	throw new NullPointerException();
3655	>	new ForEachTransformedMappingTask<K,V,U>
3656	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3657	>	transformer, action).invoke();
3658	>	}
3659	>
3660	>	/**
3661	>	* Returns a non-null result from applying the given search
3662	>	* function on each (key, value), or null if none.  Upon
3663	>	* success, further element processing is suppressed and the
3664	>	* results of any other parallel invocations of the search
3665	>	* function are ignored.
3666	>	*
3667	>	* @param parallelismThreshold the (estimated) number of elements
3668	>	* needed for this operation to be executed in parallel
3669	>	* @param searchFunction a function returning a non-null
3670	>	* result on success, else null
3671	>	* @param <U> the return type of the search function
3672	>	* @return a non-null result from applying the given search
3673	>	* function on each (key, value), or null if none
3674	>	* @since 1.8
3675	>	*/
3676	>	public <U> U search(long parallelismThreshold,
3677	>	BiFunction<? super K, ? super V, ? extends U> searchFunction) {
3678	>	if (searchFunction == null) throw new NullPointerException();
3679	>	return new SearchMappingsTask<K,V,U>
3680	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3681	>	searchFunction, new AtomicReference<U>()).invoke();
3682	>	}
3683	>
3684	>	/**
3685	>	* Returns the result of accumulating the given transformation
3686	>	* of all (key, value) pairs using the given reducer to
3687	>	* combine values, or null if none.
3688	>	*
3689	>	* @param parallelismThreshold the (estimated) number of elements
3690	>	* needed for this operation to be executed in parallel
3691	>	* @param transformer a function returning the transformation
3692	>	* for an element, or null if there is no transformation (in
3693	>	* which case it is not combined)
3694	>	* @param reducer a commutative associative combining function
3695	>	* @param <U> the return type of the transformer
3696	>	* @return the result of accumulating the given transformation
3697	>	* of all (key, value) pairs
3698	>	* @since 1.8
3699	>	*/
3700	>	public <U> U reduce(long parallelismThreshold,
3701	>	BiFunction<? super K, ? super V, ? extends U> transformer,
3702	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3703	>	if (transformer == null || reducer == null)
3704	>	throw new NullPointerException();
3705	>	return new MapReduceMappingsTask<K,V,U>
3706	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3707	>	null, transformer, reducer).invoke();
3708	>	}
3709	>
3710	>	/**
3711	>	* Returns the result of accumulating the given transformation
3712	>	* of all (key, value) pairs using the given reducer to
3713	>	* combine values, and the given basis as an identity value.
3714	>	*
3715	>	* @param parallelismThreshold the (estimated) number of elements
3716	>	* needed for this operation to be executed in parallel
3717	>	* @param transformer a function returning the transformation
3718	>	* for an element
3719	>	* @param basis the identity (initial default value) for the reduction
3720	>	* @param reducer a commutative associative combining function
3721	>	* @return the result of accumulating the given transformation
3722	>	* of all (key, value) pairs
3723	>	* @since 1.8
3724	>	*/
3725	>	public double reduceToDouble(long parallelismThreshold,
3726	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3727	>	double basis,
3728	>	DoubleBinaryOperator reducer) {
3729	>	if (transformer == null || reducer == null)
3730	>	throw new NullPointerException();
3731	>	return new MapReduceMappingsToDoubleTask<K,V>
3732	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3733	>	null, transformer, basis, reducer).invoke();
3734	>	}
3735	>
3736	>	/**
3737	>	* Returns the result of accumulating the given transformation
3738	>	* of all (key, value) pairs using the given reducer to
3739	>	* combine values, and the given basis as an identity value.
3740	>	*
3741	>	* @param parallelismThreshold the (estimated) number of elements
3742	>	* needed for this operation to be executed in parallel
3743	>	* @param transformer a function returning the transformation
3744	>	* for an element
3745	>	* @param basis the identity (initial default value) for the reduction
3746	>	* @param reducer a commutative associative combining function
3747	>	* @return the result of accumulating the given transformation
3748	>	* of all (key, value) pairs
3749	>	* @since 1.8
3750	>	*/
3751	>	public long reduceToLong(long parallelismThreshold,
3752	>	ToLongBiFunction<? super K, ? super V> transformer,
3753	>	long basis,
3754	>	LongBinaryOperator reducer) {
3755	>	if (transformer == null || reducer == null)
3756	>	throw new NullPointerException();
3757	>	return new MapReduceMappingsToLongTask<K,V>
3758	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3759	>	null, transformer, basis, reducer).invoke();
3760	>	}
3761	>
3762	>	/**
3763	>	* Returns the result of accumulating the given transformation
3764	>	* of all (key, value) pairs using the given reducer to
3765	>	* combine values, and 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 (key, value) pairs
3775	>	* @since 1.8
3776	>	*/
3777	>	public int reduceToInt(long parallelismThreshold,
3778	>	ToIntBiFunction<? super K, ? super V> transformer,
3779	>	int basis,
3780	>	IntBinaryOperator reducer) {
3781	>	if (transformer == null || reducer == null)
3782	>	throw new NullPointerException();
3783	>	return new MapReduceMappingsToIntTask<K,V>
3784	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3785	>	null, transformer, basis, reducer).invoke();
3786	>	}
3787	>
3788	>	/**
3789	>	* Performs the given action for each key.
3790	>	*
3791	>	* @param parallelismThreshold the (estimated) number of elements
3792	>	* needed for this operation to be executed in parallel
3793	>	* @param action the action
3794	>	* @since 1.8
3795	>	*/
3796	>	public void forEachKey(long parallelismThreshold,
3797	>	Consumer<? super K> action) {
3798	>	if (action == null) throw new NullPointerException();
3799	>	new ForEachKeyTask<K,V>
3800	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3801	>	action).invoke();
3802	>	}
3803	>
3804	>	/**
3805	>	* Performs the given action for each non-null transformation
3806	>	* of each key.
3807	>	*
3808	>	* @param parallelismThreshold the (estimated) number of elements
3809	>	* needed for this operation to be executed in parallel
3810	>	* @param transformer a function returning the transformation
3811	>	* for an element, or null if there is no transformation (in
3812	>	* which case the action is not applied)
3813	>	* @param action the action
3814	>	* @param <U> the return type of the transformer
3815	>	* @since 1.8
3816	>	*/
3817	>	public <U> void forEachKey(long parallelismThreshold,
3818	>	Function<? super K, ? extends U> transformer,
3819	>	Consumer<? super U> action) {
3820	>	if (transformer == null || action == null)
3821	>	throw new NullPointerException();
3822	>	new ForEachTransformedKeyTask<K,V,U>
3823	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3824	>	transformer, action).invoke();
3825	>	}
3826	>
3827	>	/**
3828	>	* Returns a non-null result from applying the given search
3829	>	* function on each key, or null if none. Upon success,
3830	>	* further element processing is suppressed and the results of
3831	>	* any other parallel invocations of the search function are
3832	>	* ignored.
3833	>	*
3834	>	* @param parallelismThreshold the (estimated) number of elements
3835	>	* needed for this operation to be executed in parallel
3836	>	* @param searchFunction a function returning a non-null
3837	>	* result on success, else null
3838	>	* @param <U> the return type of the search function
3839	>	* @return a non-null result from applying the given search
3840	>	* function on each key, or null if none
3841	>	* @since 1.8
3842	>	*/
3843	>	public <U> U searchKeys(long parallelismThreshold,
3844	>	Function<? super K, ? extends U> searchFunction) {
3845	>	if (searchFunction == null) throw new NullPointerException();
3846	>	return new SearchKeysTask<K,V,U>
3847	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3848	>	searchFunction, new AtomicReference<U>()).invoke();
3849	>	}
3850	>
3851	>	/**
3852	>	* Returns the result of accumulating all keys using the given
3853	>	* reducer to combine values, or null if none.
3854	>	*
3855	>	* @param parallelismThreshold the (estimated) number of elements
3856	>	* needed for this operation to be executed in parallel
3857	>	* @param reducer a commutative associative combining function
3858	>	* @return the result of accumulating all keys using the given
3859	>	* reducer to combine values, or null if none
3860	>	* @since 1.8
3861	>	*/
3862	>	public K reduceKeys(long parallelismThreshold,
3863	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
3864	>	if (reducer == null) throw new NullPointerException();
3865	>	return new ReduceKeysTask<K,V>
3866	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3867	>	null, reducer).invoke();
3868	>	}
3869	>
3870	>	/**
3871	>	* Returns the result of accumulating the given transformation
3872	>	* of all keys using the given reducer to combine values, or
3873	>	* null if none.
3874	>	*
3875	>	* @param parallelismThreshold the (estimated) number of elements
3876	>	* needed for this operation to be executed in parallel
3877	>	* @param transformer a function returning the transformation
3878	>	* for an element, or null if there is no transformation (in
3879	>	* which case it is not combined)
3880	>	* @param reducer a commutative associative combining function
3881	>	* @param <U> the return type of the transformer
3882	>	* @return the result of accumulating the given transformation
3883	>	* of all keys
3884	>	* @since 1.8
3885	>	*/
3886	>	public <U> U reduceKeys(long parallelismThreshold,
3887	>	Function<? super K, ? extends U> transformer,
3888	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
3889	>	if (transformer == null || reducer == null)
3890	>	throw new NullPointerException();
3891	>	return new MapReduceKeysTask<K,V,U>
3892	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3893	>	null, transformer, reducer).invoke();
3894	>	}
3895	>
3896	>	/**
3897	>	* Returns the result of accumulating the given transformation
3898	>	* of all keys using the given reducer to combine values, and
3899	>	* the given basis as an identity value.
3900	>	*
3901	>	* @param parallelismThreshold the (estimated) number of elements
3902	>	* needed for this operation to be executed in parallel
3903	>	* @param transformer a function returning the transformation
3904	>	* for an element
3905	>	* @param basis the identity (initial default value) for the reduction
3906	>	* @param reducer a commutative associative combining function
3907	>	* @return the result of accumulating the given transformation
3908	>	* of all keys
3909	>	* @since 1.8
3910	>	*/
3911	>	public double reduceKeysToDouble(long parallelismThreshold,
3912	>	ToDoubleFunction<? super K> transformer,
3913	>	double basis,
3914	>	DoubleBinaryOperator reducer) {
3915	>	if (transformer == null || reducer == null)
3916	>	throw new NullPointerException();
3917	>	return new MapReduceKeysToDoubleTask<K,V>
3918	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3919	>	null, transformer, basis, reducer).invoke();
3920	>	}
3921	>
3922	>	/**
3923	>	* Returns the result of accumulating the given transformation
3924	>	* of all keys using the given reducer to combine values, and
3925	>	* the given basis as an identity value.
3926	>	*
3927	>	* @param parallelismThreshold the (estimated) number of elements
3928	>	* needed for this operation to be executed in parallel
3929	>	* @param transformer a function returning the transformation
3930	>	* for an element
3931	>	* @param basis the identity (initial default value) for the reduction
3932	>	* @param reducer a commutative associative combining function
3933	>	* @return the result of accumulating the given transformation
3934	>	* of all keys
3935	>	* @since 1.8
3936	>	*/
3937	>	public long reduceKeysToLong(long parallelismThreshold,
3938	>	ToLongFunction<? super K> transformer,
3939	>	long basis,
3940	>	LongBinaryOperator reducer) {
3941	>	if (transformer == null || reducer == null)
3942	>	throw new NullPointerException();
3943	>	return new MapReduceKeysToLongTask<K,V>
3944	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3945	>	null, transformer, basis, reducer).invoke();
3946	>	}
3947	>
3948	>	/**
3949	>	* Returns the result of accumulating the given transformation
3950	>	* of all keys using the given reducer to combine values, and
3951	>	* the given basis as an identity value.
3952	>	*
3953	>	* @param parallelismThreshold the (estimated) number of elements
3954	>	* needed for this operation to be executed in parallel
3955	>	* @param transformer a function returning the transformation
3956	>	* for an element
3957	>	* @param basis the identity (initial default value) for the reduction
3958	>	* @param reducer a commutative associative combining function
3959	>	* @return the result of accumulating the given transformation
3960	>	* of all keys
3961	>	* @since 1.8
3962	>	*/
3963	>	public int reduceKeysToInt(long parallelismThreshold,
3964	>	ToIntFunction<? super K> transformer,
3965	>	int basis,
3966	>	IntBinaryOperator reducer) {
3967	>	if (transformer == null || reducer == null)
3968	>	throw new NullPointerException();
3969	>	return new MapReduceKeysToIntTask<K,V>
3970	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3971	>	null, transformer, basis, reducer).invoke();
3972	>	}
3973	>
3974	>	/**
3975	>	* Performs the given action for each value.
3976	>	*
3977	>	* @param parallelismThreshold the (estimated) number of elements
3978	>	* needed for this operation to be executed in parallel
3979	>	* @param action the action
3980	>	* @since 1.8
3981	>	*/
3982	>	public void forEachValue(long parallelismThreshold,
3983	>	Consumer<? super V> action) {
3984	>	if (action == null)
3985	>	throw new NullPointerException();
3986	>	new ForEachValueTask<K,V>
3987	>	(null, batchFor(parallelismThreshold), 0, 0, table,
3988	>	action).invoke();
3989	>	}
3990	>
3991	>	/**
3992	>	* Performs the given action for each non-null transformation
3993	>	* of each value.
3994	>	*
3995	>	* @param parallelismThreshold the (estimated) number of elements
3996	>	* needed for this operation to be executed in parallel
3997	>	* @param transformer a function returning the transformation
3998	>	* for an element, or null if there is no transformation (in
3999	>	* which case the action is not applied)
4000	>	* @param action the action
4001	>	* @param <U> the return type of the transformer
4002	>	* @since 1.8
4003	>	*/
4004	>	public <U> void forEachValue(long parallelismThreshold,
4005	>	Function<? super V, ? extends U> transformer,
4006	>	Consumer<? super U> action) {
4007	>	if (transformer == null || action == null)
4008	>	throw new NullPointerException();
4009	>	new ForEachTransformedValueTask<K,V,U>
4010	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4011	>	transformer, action).invoke();
4012	>	}
4013	>
4014	>	/**
4015	>	* Returns a non-null result from applying the given search
4016	>	* function on each value, or null if none.  Upon success,
4017	>	* further element processing is suppressed and the results of
4018	>	* any other parallel invocations of the search function are
4019	>	* ignored.
4020	>	*
4021	>	* @param parallelismThreshold the (estimated) number of elements
4022	>	* needed for this operation to be executed in parallel
4023	>	* @param searchFunction a function returning a non-null
4024	>	* result on success, else null
4025	>	* @param <U> the return type of the search function
4026	>	* @return a non-null result from applying the given search
4027	>	* function on each value, or null if none
4028	>	* @since 1.8
4029	>	*/
4030	>	public <U> U searchValues(long parallelismThreshold,
4031	>	Function<? super V, ? extends U> searchFunction) {
4032	>	if (searchFunction == null) throw new NullPointerException();
4033	>	return new SearchValuesTask<K,V,U>
4034	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4035	>	searchFunction, new AtomicReference<U>()).invoke();
4036	>	}
4037	>
4038	>	/**
4039	>	* Returns the result of accumulating all values using the
4040	>	* given reducer to combine values, or null if none.
4041	>	*
4042	>	* @param parallelismThreshold the (estimated) number of elements
4043	>	* needed for this operation to be executed in parallel
4044	>	* @param reducer a commutative associative combining function
4045	>	* @return the result of accumulating all values
4046	>	* @since 1.8
4047	>	*/
4048	>	public V reduceValues(long parallelismThreshold,
4049	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
4050	>	if (reducer == null) throw new NullPointerException();
4051	>	return new ReduceValuesTask<K,V>
4052	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4053	>	null, reducer).invoke();
4054	>	}
4055	>
4056	>	/**
4057	>	* Returns the result of accumulating the given transformation
4058	>	* of all values using the given reducer to combine values, or
4059	>	* null if none.
4060	>	*
4061	>	* @param parallelismThreshold the (estimated) number of elements
4062	>	* needed for this operation to be executed in parallel
4063	>	* @param transformer a function returning the transformation
4064	>	* for an element, or null if there is no transformation (in
4065	>	* which case it is not combined)
4066	>	* @param reducer a commutative associative combining function
4067	>	* @param <U> the return type of the transformer
4068	>	* @return the result of accumulating the given transformation
4069	>	* of all values
4070	>	* @since 1.8
4071	>	*/
4072	>	public <U> U reduceValues(long parallelismThreshold,
4073	>	Function<? super V, ? extends U> transformer,
4074	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4075	>	if (transformer == null || reducer == null)
4076	>	throw new NullPointerException();
4077	>	return new MapReduceValuesTask<K,V,U>
4078	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4079	>	null, transformer, reducer).invoke();
4080	>	}
4081	>
4082	>	/**
4083	>	* Returns the result of accumulating the given transformation
4084	>	* of all values using the given reducer to combine values,
4085	>	* and the given basis as an identity value.
4086	>	*
4087	>	* @param parallelismThreshold the (estimated) number of elements
4088	>	* needed for this operation to be executed in parallel
4089	>	* @param transformer a function returning the transformation
4090	>	* for an element
4091	>	* @param basis the identity (initial default value) for the reduction
4092	>	* @param reducer a commutative associative combining function
4093	>	* @return the result of accumulating the given transformation
4094	>	* of all values
4095	>	* @since 1.8
4096	>	*/
4097	>	public double reduceValuesToDouble(long parallelismThreshold,
4098	>	ToDoubleFunction<? super V> transformer,
4099	>	double basis,
4100	>	DoubleBinaryOperator reducer) {
4101	>	if (transformer == null || reducer == null)
4102	>	throw new NullPointerException();
4103	>	return new MapReduceValuesToDoubleTask<K,V>
4104	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4105	>	null, transformer, basis, reducer).invoke();
4106	>	}
4107	>
4108	>	/**
4109	>	* Returns the result of accumulating the given transformation
4110	>	* of all values using the given reducer to combine values,
4111	>	* and the given basis as an identity value.
4112	>	*
4113	>	* @param parallelismThreshold the (estimated) number of elements
4114	>	* needed for this operation to be executed in parallel
4115	>	* @param transformer a function returning the transformation
4116	>	* for an element
4117	>	* @param basis the identity (initial default value) for the reduction
4118	>	* @param reducer a commutative associative combining function
4119	>	* @return the result of accumulating the given transformation
4120	>	* of all values
4121	>	* @since 1.8
4122	>	*/
4123	>	public long reduceValuesToLong(long parallelismThreshold,
4124	>	ToLongFunction<? super V> transformer,
4125	>	long basis,
4126	>	LongBinaryOperator reducer) {
4127	>	if (transformer == null || reducer == null)
4128	>	throw new NullPointerException();
4129	>	return new MapReduceValuesToLongTask<K,V>
4130	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4131	>	null, transformer, basis, reducer).invoke();
4132	>	}
4133	>
4134	>	/**
4135	>	* Returns the result of accumulating the given transformation
4136	>	* of all values using the given reducer to combine values,
4137	>	* and the given basis as an identity value.
4138	>	*
4139	>	* @param parallelismThreshold the (estimated) number of elements
4140	>	* needed for this operation to be executed in parallel
4141	>	* @param transformer a function returning the transformation
4142	>	* for an element
4143	>	* @param basis the identity (initial default value) for the reduction
4144	>	* @param reducer a commutative associative combining function
4145	>	* @return the result of accumulating the given transformation
4146	>	* of all values
4147	>	* @since 1.8
4148	>	*/
4149	>	public int reduceValuesToInt(long parallelismThreshold,
4150	>	ToIntFunction<? super V> transformer,
4151	>	int basis,
4152	>	IntBinaryOperator reducer) {
4153	>	if (transformer == null || reducer == null)
4154	>	throw new NullPointerException();
4155	>	return new MapReduceValuesToIntTask<K,V>
4156	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4157	>	null, transformer, basis, reducer).invoke();
4158	>	}
4159	>
4160	>	/**
4161	>	* Performs the given action for each entry.
4162	>	*
4163	>	* @param parallelismThreshold the (estimated) number of elements
4164	>	* needed for this operation to be executed in parallel
4165	>	* @param action the action
4166	>	* @since 1.8
4167	>	*/
4168	>	public void forEachEntry(long parallelismThreshold,
4169	>	Consumer<? super Map.Entry<K,V>> action) {
4170	>	if (action == null) throw new NullPointerException();
4171	>	new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
4172	>	action).invoke();
4173	>	}
4174	>
4175	>	/**
4176	>	* Performs the given action for each non-null transformation
4177	>	* of each entry.
4178	>	*
4179	>	* @param parallelismThreshold the (estimated) number of elements
4180	>	* needed for this operation to be executed in parallel
4181	>	* @param transformer a function returning the transformation
4182	>	* for an element, or null if there is no transformation (in
4183	>	* which case the action is not applied)
4184	>	* @param action the action
4185	>	* @param <U> the return type of the transformer
4186	>	* @since 1.8
4187	>	*/
4188	>	public <U> void forEachEntry(long parallelismThreshold,
4189	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4190	>	Consumer<? super U> action) {
4191	>	if (transformer == null || action == null)
4192	>	throw new NullPointerException();
4193	>	new ForEachTransformedEntryTask<K,V,U>
4194	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4195	>	transformer, action).invoke();
4196	>	}
4197	>
4198	>	/**
4199	>	* Returns a non-null result from applying the given search
4200	>	* function on each entry, or null if none.  Upon success,
4201	>	* further element processing is suppressed and the results of
4202	>	* any other parallel invocations of the search function are
4203	>	* ignored.
4204	>	*
4205	>	* @param parallelismThreshold the (estimated) number of elements
4206	>	* needed for this operation to be executed in parallel
4207	>	* @param searchFunction a function returning a non-null
4208	>	* result on success, else null
4209	>	* @param <U> the return type of the search function
4210	>	* @return a non-null result from applying the given search
4211	>	* function on each entry, or null if none
4212	>	* @since 1.8
4213	>	*/
4214	>	public <U> U searchEntries(long parallelismThreshold,
4215	>	Function<Map.Entry<K,V>, ? extends U> searchFunction) {
4216	>	if (searchFunction == null) throw new NullPointerException();
4217	>	return new SearchEntriesTask<K,V,U>
4218	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4219	>	searchFunction, new AtomicReference<U>()).invoke();
4220	>	}
4221	>
4222	>	/**
4223	>	* Returns the result of accumulating all entries using the
4224	>	* given reducer to combine values, or null if none.
4225	>	*
4226	>	* @param parallelismThreshold the (estimated) number of elements
4227	>	* needed for this operation to be executed in parallel
4228	>	* @param reducer a commutative associative combining function
4229	>	* @return the result of accumulating all entries
4230	>	* @since 1.8
4231	>	*/
4232	>	public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
4233	>	BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
4234	>	if (reducer == null) throw new NullPointerException();
4235	>	return new ReduceEntriesTask<K,V>
4236	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4237	>	null, reducer).invoke();
4238	>	}
4239	>
4240	>	/**
4241	>	* Returns the result of accumulating the given transformation
4242	>	* of all entries using the given reducer to combine values,
4243	>	* or null if none.
4244	>	*
4245	>	* @param parallelismThreshold the (estimated) number of elements
4246	>	* needed for this operation to be executed in parallel
4247	>	* @param transformer a function returning the transformation
4248	>	* for an element, or null if there is no transformation (in
4249	>	* which case it is not combined)
4250	>	* @param reducer a commutative associative combining function
4251	>	* @param <U> the return type of the transformer
4252	>	* @return the result of accumulating the given transformation
4253	>	* of all entries
4254	>	* @since 1.8
4255	>	*/
4256	>	public <U> U reduceEntries(long parallelismThreshold,
4257	>	Function<Map.Entry<K,V>, ? extends U> transformer,
4258	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
4259	>	if (transformer == null || reducer == null)
4260	>	throw new NullPointerException();
4261	>	return new MapReduceEntriesTask<K,V,U>
4262	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4263	>	null, transformer, reducer).invoke();
4264	>	}
4265	>
4266	>	/**
4267	>	* Returns the result of accumulating the given transformation
4268	>	* of all entries using the given reducer to combine values,
4269	>	* and the given basis as an identity value.
4270	>	*
4271	>	* @param parallelismThreshold the (estimated) number of elements
4272	>	* needed for this operation to be executed in parallel
4273	>	* @param transformer a function returning the transformation
4274	>	* for an element
4275	>	* @param basis the identity (initial default value) for the reduction
4276	>	* @param reducer a commutative associative combining function
4277	>	* @return the result of accumulating the given transformation
4278	>	* of all entries
4279	>	* @since 1.8
4280	>	*/
4281	>	public double reduceEntriesToDouble(long parallelismThreshold,
4282	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
4283	>	double basis,
4284	>	DoubleBinaryOperator reducer) {
4285	>	if (transformer == null || reducer == null)
4286	>	throw new NullPointerException();
4287	>	return new MapReduceEntriesToDoubleTask<K,V>
4288	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4289	>	null, transformer, basis, reducer).invoke();
4290	>	}
4291	>
4292	>	/**
4293	>	* Returns the result of accumulating the given transformation
4294	>	* of all entries using the given reducer to combine values,
4295	>	* and the given basis as an identity value.
4296	>	*
4297	>	* @param parallelismThreshold the (estimated) number of elements
4298	>	* needed for this operation to be executed in parallel
4299	>	* @param transformer a function returning the transformation
4300	>	* for an element
4301	>	* @param basis the identity (initial default value) for the reduction
4302	>	* @param reducer a commutative associative combining function
4303	>	* @return the result of accumulating the given transformation
4304	>	* of all entries
4305	>	* @since 1.8
4306	>	*/
4307	>	public long reduceEntriesToLong(long parallelismThreshold,
4308	>	ToLongFunction<Map.Entry<K,V>> transformer,
4309	>	long basis,
4310	>	LongBinaryOperator reducer) {
4311	>	if (transformer == null || reducer == null)
4312	>	throw new NullPointerException();
4313	>	return new MapReduceEntriesToLongTask<K,V>
4314	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4315	>	null, transformer, basis, reducer).invoke();
4316	>	}
4317	>
4318	>	/**
4319	>	* Returns the result of accumulating the given transformation
4320	>	* of all entries using the given reducer to combine values,
4321	>	* and the given basis as an identity value.
4322	>	*
4323	>	* @param parallelismThreshold the (estimated) number of elements
4324	>	* needed for this operation to be executed in parallel
4325	>	* @param transformer a function returning the transformation
4326	>	* for an element
4327	>	* @param basis the identity (initial default value) for the reduction
4328	>	* @param reducer a commutative associative combining function
4329	>	* @return the result of accumulating the given transformation
4330	>	* of all entries
4331	>	* @since 1.8
4332	>	*/
4333	>	public int reduceEntriesToInt(long parallelismThreshold,
4334	>	ToIntFunction<Map.Entry<K,V>> transformer,
4335	>	int basis,
4336	>	IntBinaryOperator reducer) {
4337	>	if (transformer == null || reducer == null)
4338	>	throw new NullPointerException();
4339	>	return new MapReduceEntriesToIntTask<K,V>
4340	>	(null, batchFor(parallelismThreshold), 0, 0, table,
4341	>	null, transformer, basis, reducer).invoke();
4342	>	}
4343	>
4344	>
4345	>	/* ----------------Views -------------- */
4346	>
4347	>	/**
4348	>	* Base class for views.
4349	>	*/
4350	>	abstract static class CollectionView<K,V,E>
4351	>	implements Collection<E>, java.io.Serializable {
4352	>	private static final long serialVersionUID = 7249069246763182397L;
4353	>	final ConcurrentHashMap<K,V> map;
4354	>	CollectionView(ConcurrentHashMap<K,V> map)  { this.map = map; }
4355	>
4356	>	/**
4357	>	* Returns the map backing this view.
4358	>	*
4359	>	* @return the map backing this view
4360	>	*/
4361	>	public ConcurrentHashMap<K,V> getMap() { return map; }
4362	>
4363	>	/**
4364	>	* Removes all of the elements from this view, by removing all
4365	>	* the mappings from the map backing this view.
4366	>	*/
4367	>	public final void clear()      { map.clear(); }
4368	>	public final int size()        { return map.size(); }
4369	>	public final boolean isEmpty() { return map.isEmpty(); }
4370	>
4371	>	// implementations below rely on concrete classes supplying these
4372	>	// abstract methods
4373	>	/**
4374	>	* Returns an iterator over the elements in this collection.
4375	>	*
4376	>	* <p>The returned iterator is
4377	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4378	>	*
4379	>	* @return an iterator over the elements in this collection
4380	>	*/
4381	>	public abstract Iterator<E> iterator();
4382	>	public abstract boolean contains(Object o);
4383	>	public abstract boolean remove(Object o);
4384	>
4385	>	private static final String oomeMsg = "Required array size too large";
4386	>
4387	>	public final Object[] toArray() {
4388	>	long sz = map.mappingCount();
4389	>	if (sz > MAX_ARRAY_SIZE)
4390	>	throw new OutOfMemoryError(oomeMsg);
4391	>	int n = (int)sz;
4392	>	Object[] r = new Object[n];
4393	>	int i = 0;
4394	>	for (E e : this) {
4395	>	if (i == n) {
4396	>	if (n >= MAX_ARRAY_SIZE)
4397	>	throw new OutOfMemoryError(oomeMsg);
4398	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4399	>	n = MAX_ARRAY_SIZE;
4400	>	else
4401	>	n += (n >>> 1) + 1;
4402	>	r = Arrays.copyOf(r, n);
4403	>	}
4404	>	r[i++] = e;
4405	>	}
4406	>	return (i == n) ? r : Arrays.copyOf(r, i);
4407		}
4408	<	public void clear() {
4409	<	ConcurrentHashMap.this.clear();
4408	>
4409	>	@SuppressWarnings("unchecked")
4410	>	public final <T> T[] toArray(T[] a) {
4411	>	long sz = map.mappingCount();
4412	>	if (sz > MAX_ARRAY_SIZE)
4413	>	throw new OutOfMemoryError(oomeMsg);
4414	>	int m = (int)sz;
4415	>	T[] r = (a.length >= m) ? a :
4416	>	(T[])java.lang.reflect.Array
4417	>	.newInstance(a.getClass().getComponentType(), m);
4418	>	int n = r.length;
4419	>	int i = 0;
4420	>	for (E e : this) {
4421	>	if (i == n) {
4422	>	if (n >= MAX_ARRAY_SIZE)
4423	>	throw new OutOfMemoryError(oomeMsg);
4424	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4425	>	n = MAX_ARRAY_SIZE;
4426	>	else
4427	>	n += (n >>> 1) + 1;
4428	>	r = Arrays.copyOf(r, n);
4429	>	}
4430	>	r[i++] = (T)e;
4431	>	}
4432	>	if (a == r && i < n) {
4433	>	r[i] = null; // null-terminate
4434	>	return r;
4435	>	}
4436	>	return (i == n) ? r : Arrays.copyOf(r, i);
4437		}
4438	+
4439	+	/**
4440	+	* Returns a string representation of this collection.
4441	+	* The string representation consists of the string representations
4442	+	* of the collection's elements in the order they are returned by
4443	+	* its iterator, enclosed in square brackets ({@code "[]"}).
4444	+	* Adjacent elements are separated by the characters {@code ", "}
4445	+	* (comma and space).  Elements are converted to strings as by
4446	+	* {@link String#valueOf(Object)}.
4447	+	*
4448	+	* @return a string representation of this collection
4449	+	*/
4450	+	public final String toString() {
4451	+	StringBuilder sb = new StringBuilder();
4452	+	sb.append('[');
4453	+	Iterator<E> it = iterator();
4454	+	if (it.hasNext()) {
4455	+	for (;;) {
4456	+	Object e = it.next();
4457	+	sb.append(e == this ? "(this Collection)" : e);
4458	+	if (!it.hasNext())
4459	+	break;
4460	+	sb.append(',').append(' ');
4461	+	}
4462	+	}
4463	+	return sb.append(']').toString();
4464	+	}
4465	+
4466	+	public final boolean containsAll(Collection<?> c) {
4467	+	if (c != this) {
4468	+	for (Object e : c) {
4469	+	if (e == null || !contains(e))
4470	+	return false;
4471	+	}
4472	+	}
4473	+	return true;
4474	+	}
4475	+
4476	+	public final boolean removeAll(Collection<?> c) {
4477	+	if (c == null) throw new NullPointerException();
4478	+	boolean modified = false;
4479	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4480	+	if (c.contains(it.next())) {
4481	+	it.remove();
4482	+	modified = true;
4483	+	}
4484	+	}
4485	+	return modified;
4486	+	}
4487	+
4488	+	public final boolean retainAll(Collection<?> c) {
4489	+	if (c == null) throw new NullPointerException();
4490	+	boolean modified = false;
4491	+	for (Iterator<E> it = iterator(); it.hasNext();) {
4492	+	if (!c.contains(it.next())) {
4493	+	it.remove();
4494	+	modified = true;
4495	+	}
4496	+	}
4497	+	return modified;
4498	+	}
4499	+
4500		}
4501
4502	<	final class Values extends AbstractCollection<V> {
4503	<	public Iterator<V> iterator() {
4504	<	return new ValueIterator();
4502	>	/**
4503	>	* A view of a ConcurrentHashMap as a {@link Set} of keys, in
4504	>	* which additions may optionally be enabled by mapping to a
4505	>	* common value.  This class cannot be directly instantiated.
4506	>	* See {@link #keySet() keySet()},
4507	>	* {@link #keySet(Object) keySet(V)},
4508	>	* {@link #newKeySet() newKeySet()},
4509	>	* {@link #newKeySet(int) newKeySet(int)}.
4510	>	*
4511	>	* @since 1.8
4512	>	*/
4513	>	public static class KeySetView<K,V> extends CollectionView<K,V,K>
4514	>	implements Set<K>, java.io.Serializable {
4515	>	private static final long serialVersionUID = 7249069246763182397L;
4516	>	private final V value;
4517	>	KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
4518	>	super(map);
4519	>	this.value = value;
4520		}
4521	<	public int size() {
4522	<	return ConcurrentHashMap.this.size();
4521	>
4522	>	/**
4523	>	* Returns the default mapped value for additions,
4524	>	* or {@code null} if additions are not supported.
4525	>	*
4526	>	* @return the default mapped value for additions, or {@code null}
4527	>	* if not supported
4528	>	*/
4529	>	public V getMappedValue() { return value; }
4530	>
4531	>	/**
4532	>	* {@inheritDoc}
4533	>	* @throws NullPointerException if the specified key is null
4534	>	*/
4535	>	public boolean contains(Object o) { return map.containsKey(o); }
4536	>
4537	>	/**
4538	>	* Removes the key from this map view, by removing the key (and its
4539	>	* corresponding value) from the backing map.  This method does
4540	>	* nothing if the key is not in the map.
4541	>	*
4542	>	* @param  o the key to be removed from the backing map
4543	>	* @return {@code true} if the backing map contained the specified key
4544	>	* @throws NullPointerException if the specified key is null
4545	>	*/
4546	>	public boolean remove(Object o) { return map.remove(o) != null; }
4547	>
4548	>	/**
4549	>	* @return an iterator over the keys of the backing map
4550	>	*/
4551	>	public Iterator<K> iterator() {
4552	>	Node<K,V>[] t;
4553	>	ConcurrentHashMap<K,V> m = map;
4554	>	int f = (t = m.table) == null ? 0 : t.length;
4555	>	return new KeyIterator<K,V>(t, f, 0, f, m);
4556		}
4557	<	public boolean isEmpty() {
4558	<	return ConcurrentHashMap.this.isEmpty();
4557	>
4558	>	/**
4559	>	* Adds the specified key to this set view by mapping the key to
4560	>	* the default mapped value in the backing map, if defined.
4561	>	*
4562	>	* @param e key to be added
4563	>	* @return {@code true} if this set changed as a result of the call
4564	>	* @throws NullPointerException if the specified key is null
4565	>	* @throws UnsupportedOperationException if no default mapped value
4566	>	* for additions was provided
4567	>	*/
4568	>	public boolean add(K e) {
4569	>	V v;
4570	>	if ((v = value) == null)
4571	>	throw new UnsupportedOperationException();
4572	>	return map.putVal(e, v, true) == null;
4573		}
4574	<	public boolean contains(Object o) {
4575	<	return ConcurrentHashMap.this.containsValue(o);
4574	>
4575	>	/**
4576	>	* Adds all of the elements in the specified collection to this set,
4577	>	* as if by calling {@link #add} on each one.
4578	>	*
4579	>	* @param c the elements to be inserted into this set
4580	>	* @return {@code true} if this set changed as a result of the call
4581	>	* @throws NullPointerException if the collection or any of its
4582	>	* elements are {@code null}
4583	>	* @throws UnsupportedOperationException if no default mapped value
4584	>	* for additions was provided
4585	>	*/
4586	>	public boolean addAll(Collection<? extends K> c) {
4587	>	boolean added = false;
4588	>	V v;
4589	>	if ((v = value) == null)
4590	>	throw new UnsupportedOperationException();
4591	>	for (K e : c) {
4592	>	if (map.putVal(e, v, true) == null)
4593	>	added = true;
4594	>	}
4595	>	return added;
4596		}
4597	<	public void clear() {
4598	<	ConcurrentHashMap.this.clear();
4597	>
4598	>	public int hashCode() {
4599	>	int h = 0;
4600	>	for (K e : this)
4601	>	h += e.hashCode();
4602	>	return h;
4603	>	}
4604	>
4605	>	public boolean equals(Object o) {
4606	>	Set<?> c;
4607	>	return ((o instanceof Set) &&
4608	>	((c = (Set<?>)o) == this ||
4609	>	(containsAll(c) && c.containsAll(this))));
4610	>	}
4611	>
4612	>	public Spliterator<K> spliterator() {
4613	>	Node<K,V>[] t;
4614	>	ConcurrentHashMap<K,V> m = map;
4615	>	long n = m.sumCount();
4616	>	int f = (t = m.table) == null ? 0 : t.length;
4617	>	return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4618	>	}
4619	>
4620	>	public void forEach(Consumer<? super K> action) {
4621	>	if (action == null) throw new NullPointerException();
4622	>	Node<K,V>[] t;
4623	>	if ((t = map.table) != null) {
4624	>	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4625	>	for (Node<K,V> p; (p = it.advance()) != null; )
4626	>	action.accept(p.key);
4627	>	}
4628		}
4629		}
4630
4631	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
4632	<	public Iterator<Map.Entry<K,V>> iterator() {
4633	<	return new EntryIterator();
4631	>	/**
4632	>	* A view of a ConcurrentHashMap as a {@link Collection} of
4633	>	* values, in which additions are disabled. This class cannot be
4634	>	* directly instantiated. See {@link #values()}.
4635	>	*/
4636	>	static final class ValuesView<K,V> extends CollectionView<K,V,V>
4637	>	implements Collection<V>, java.io.Serializable {
4638	>	private static final long serialVersionUID = 2249069246763182397L;
4639	>	ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
4640	>	public final boolean contains(Object o) {
4641	>	return map.containsValue(o);
4642	>	}
4643	>
4644	>	public final boolean remove(Object o) {
4645	>	if (o != null) {
4646	>	for (Iterator<V> it = iterator(); it.hasNext();) {
4647	>	if (o.equals(it.next())) {
4648	>	it.remove();
4649	>	return true;
4650	>	}
4651	>	}
4652	>	}
4653	>	return false;
4654	>	}
4655	>
4656	>	public final Iterator<V> iterator() {
4657	>	ConcurrentHashMap<K,V> m = map;
4658	>	Node<K,V>[] t;
4659	>	int f = (t = m.table) == null ? 0 : t.length;
4660	>	return new ValueIterator<K,V>(t, f, 0, f, m);
4661		}
4662	+
4663	+	public final boolean add(V e) {
4664	+	throw new UnsupportedOperationException();
4665	+	}
4666	+	public final boolean addAll(Collection<? extends V> c) {
4667	+	throw new UnsupportedOperationException();
4668	+	}
4669	+
4670	+	public Spliterator<V> spliterator() {
4671	+	Node<K,V>[] t;
4672	+	ConcurrentHashMap<K,V> m = map;
4673	+	long n = m.sumCount();
4674	+	int f = (t = m.table) == null ? 0 : t.length;
4675	+	return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
4676	+	}
4677	+
4678	+	public void forEach(Consumer<? super V> action) {
4679	+	if (action == null) throw new NullPointerException();
4680	+	Node<K,V>[] t;
4681	+	if ((t = map.table) != null) {
4682	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4683	+	for (Node<K,V> p; (p = it.advance()) != null; )
4684	+	action.accept(p.val);
4685	+	}
4686	+	}
4687	+	}
4688	+
4689	+	/**
4690	+	* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
4691	+	* entries.  This class cannot be directly instantiated. See
4692	+	* {@link #entrySet()}.
4693	+	*/
4694	+	static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
4695	+	implements Set<Map.Entry<K,V>>, java.io.Serializable {
4696	+	private static final long serialVersionUID = 2249069246763182397L;
4697	+	EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
4698	+
4699		public boolean contains(Object o) {
4700	<	if (!(o instanceof Map.Entry))
4701	<	return false;
4702	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4703	<	V v = ConcurrentHashMap.this.get(e.getKey());
4704	<	return v != null && v.equals(e.getValue());
4700	>	Object k, v, r; Map.Entry<?,?> e;
4701	>	return ((o instanceof Map.Entry) &&
4702	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4703	>	(r = map.get(k)) != null &&
4704	>	(v = e.getValue()) != null &&
4705	>	(v == r || v.equals(r)));
4706		}
4707	+
4708		public boolean remove(Object o) {
4709	<	if (!(o instanceof Map.Entry))
4710	<	return false;
4711	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
4712	<	return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
4709	>	Object k, v; Map.Entry<?,?> e;
4710	>	return ((o instanceof Map.Entry) &&
4711	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
4712	>	(v = e.getValue()) != null &&
4713	>	map.remove(k, v));
4714		}
4715	<	public int size() {
4716	<	return ConcurrentHashMap.this.size();
4715	>
4716	>	/**
4717	>	* @return an iterator over the entries of the backing map
4718	>	*/
4719	>	public Iterator<Map.Entry<K,V>> iterator() {
4720	>	ConcurrentHashMap<K,V> m = map;
4721	>	Node<K,V>[] t;
4722	>	int f = (t = m.table) == null ? 0 : t.length;
4723	>	return new EntryIterator<K,V>(t, f, 0, f, m);
4724		}
4725	<	public boolean isEmpty() {
4726	<	return ConcurrentHashMap.this.isEmpty();
4725	>
4726	>	public boolean add(Entry<K,V> e) {
4727	>	return map.putVal(e.getKey(), e.getValue(), false) == null;
4728		}
4729	<	public void clear() {
4730	<	ConcurrentHashMap.this.clear();
4729	>
4730	>	public boolean addAll(Collection<? extends Entry<K,V>> c) {
4731	>	boolean added = false;
4732	>	for (Entry<K,V> e : c) {
4733	>	if (add(e))
4734	>	added = true;
4735	>	}
4736	>	return added;
4737		}
4738	+
4739	+	public final int hashCode() {
4740	+	int h = 0;
4741	+	Node<K,V>[] t;
4742	+	if ((t = map.table) != null) {
4743	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4744	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
4745	+	h += p.hashCode();
4746	+	}
4747	+	}
4748	+	return h;
4749	+	}
4750	+
4751	+	public final boolean equals(Object o) {
4752	+	Set<?> c;
4753	+	return ((o instanceof Set) &&
4754	+	((c = (Set<?>)o) == this ||
4755	+	(containsAll(c) && c.containsAll(this))));
4756	+	}
4757	+
4758	+	public Spliterator<Map.Entry<K,V>> spliterator() {
4759	+	Node<K,V>[] t;
4760	+	ConcurrentHashMap<K,V> m = map;
4761	+	long n = m.sumCount();
4762	+	int f = (t = m.table) == null ? 0 : t.length;
4763	+	return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
4764	+	}
4765	+
4766	+	public void forEach(Consumer<? super Map.Entry<K,V>> action) {
4767	+	if (action == null) throw new NullPointerException();
4768	+	Node<K,V>[] t;
4769	+	if ((t = map.table) != null) {
4770	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
4771	+	for (Node<K,V> p; (p = it.advance()) != null; )
4772	+	action.accept(new MapEntry<K,V>(p.key, p.val, map));
4773	+	}
4774	+	}
4775	+
4776		}
4777
4778	<	/* ---------------- Serialization Support -------------- */
4778	>	// -------------------------------------------------------
4779
4780		/**
4781	<	* Saves the state of the <tt>ConcurrentHashMap</tt> instance to a
4782	<	* stream (i.e., serializes it).
1394	<	* @param s the stream
1395	<	* @serialData
1396	<	* the key (Object) and value (Object)
1397	<	* for each key-value mapping, followed by a null pair.
1398	<	* The key-value mappings are emitted in no particular order.
4781	>	* Base class for bulk tasks. Repeats some fields and code from
4782	>	* class Traverser, because we need to subclass CountedCompleter.
4783		*/
4784	<	private void writeObject(java.io.ObjectOutputStream s) throws IOException {
4785	<	// force all segments for serialization compatibility
4786	<	for (int k = 0; k < segments.length; ++k)
4787	<	ensureSegment(k);
4788	<	s.defaultWriteObject();
4789	<
4790	<	final Segment<K,V>[] segments = this.segments;
4791	<	for (int k = 0; k < segments.length; ++k) {
4792	<	Segment<K,V> seg = segmentAt(segments, k);
4793	<	seg.lock();
4794	<	try {
4795	<	HashEntry<K,V>[] tab = seg.table;
4796	<	for (int i = 0; i < tab.length; ++i) {
4797	<	HashEntry<K,V> e;
4798	<	for (e = entryAt(tab, i); e != null; e = e.next) {
4799	<	s.writeObject(e.key);
4800	<	s.writeObject(e.value);
4784	>	@SuppressWarnings("serial")
4785	>	abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4786	>	Node<K,V>[] tab;        // same as Traverser
4787	>	Node<K,V> next;
4788	>	TableStack<K,V> stack, spare;
4789	>	int index;
4790	>	int baseIndex;
4791	>	int baseLimit;
4792	>	final int baseSize;
4793	>	int batch;              // split control
4794	>
4795	>	BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
4796	>	super(par);
4797	>	this.batch = b;
4798	>	this.index = this.baseIndex = i;
4799	>	if ((this.tab = t) == null)
4800	>	this.baseSize = this.baseLimit = 0;
4801	>	else if (par == null)
4802	>	this.baseSize = this.baseLimit = t.length;
4803	>	else {
4804	>	this.baseLimit = f;
4805	>	this.baseSize = par.baseSize;
4806	>	}
4807	>	}
4808	>
4809	>	/**
4810	>	* Same as Traverser version
4811	>	*/
4812	>	final Node<K,V> advance() {
4813	>	Node<K,V> e;
4814	>	if ((e = next) != null)
4815	>	e = e.next;
4816	>	for (;;) {
4817	>	Node<K,V>[] t; int i, n;
4818	>	if (e != null)
4819	>	return next = e;
4820	>	if (baseIndex >= baseLimit || (t = tab) == null ||
4821	>	(n = t.length) <= (i = index) || i < 0)
4822	>	return next = null;
4823	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4824	>	if (e instanceof ForwardingNode) {
4825	>	tab = ((ForwardingNode<K,V>)e).nextTable;
4826	>	e = null;
4827	>	pushState(t, i, n);
4828	>	continue;
4829		}
4830	+	else if (e instanceof TreeBin)
4831	+	e = ((TreeBin<K,V>)e).first;
4832	+	else
4833	+	e = null;
4834		}
4835	<	} finally {
4836	<	seg.unlock();
4835	>	if (stack != null)
4836	>	recoverState(n);
4837	>	else if ((index = i + baseSize) >= n)
4838	>	index = ++baseIndex;
4839		}
4840		}
4841	<	s.writeObject(null);
4842	<	s.writeObject(null);
4841	>
4842	>	private void pushState(Node<K,V>[] t, int i, int n) {
4843	>	TableStack<K,V> s = spare;
4844	>	if (s != null)
4845	>	spare = s.next;
4846	>	else
4847	>	s = new TableStack<K,V>();
4848	>	s.tab = t;
4849	>	s.length = n;
4850	>	s.index = i;
4851	>	s.next = stack;
4852	>	stack = s;
4853	>	}
4854	>
4855	>	private void recoverState(int n) {
4856	>	TableStack<K,V> s; int len;
4857	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4858	>	n = len;
4859	>	index = s.index;
4860	>	tab = s.tab;
4861	>	s.tab = null;
4862	>	TableStack<K,V> next = s.next;
4863	>	s.next = spare; // save for reuse
4864	>	stack = next;
4865	>	spare = s;
4866	>	}
4867	>	if (s == null && (index += baseSize) >= n)
4868	>	index = ++baseIndex;
4869	>	}
4870		}
4871
4872	<	/**
4873	<	* Reconstitutes the <tt>ConcurrentHashMap</tt> instance from a
4874	<	* stream (i.e., deserializes it).
4875	<	* @param s the stream
4876	<	*/
4877	<	@SuppressWarnings("unchecked")
4878	<	private void readObject(java.io.ObjectInputStream s)
4879	<	throws IOException, ClassNotFoundException {
4880	<	s.defaultReadObject();
4872	>	/*
4873	>	* Task classes. Coded in a regular but ugly format/style to
4874	>	* simplify checks that each variant differs in the right way from
4875	>	* others. The null screenings exist because compilers cannot tell
4876	>	* that we've already null-checked task arguments, so we force
4877	>	* simplest hoisted bypass to help avoid convoluted traps.
4878	>	*/
4879	>	@SuppressWarnings("serial")
4880	>	static final class ForEachKeyTask<K,V>
4881	>	extends BulkTask<K,V,Void> {
4882	>	final Consumer<? super K> action;
4883	>	ForEachKeyTask
4884	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4885	>	Consumer<? super K> action) {
4886	>	super(p, b, i, f, t);
4887	>	this.action = action;
4888	>	}
4889	>	public final void compute() {
4890	>	final Consumer<? super K> action;
4891	>	if ((action = this.action) != null) {
4892	>	for (int i = baseIndex, f, h; batch > 0 &&
4893	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4894	>	addToPendingCount(1);
4895	>	new ForEachKeyTask<K,V>
4896	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4897	>	action).fork();
4898	>	}
4899	>	for (Node<K,V> p; (p = advance()) != null;)
4900	>	action.accept(p.key);
4901	>	propagateCompletion();
4902	>	}
4903	>	}
4904	>	}
4905
4906	<	// Re-initialize segments to be minimally sized, and let grow.
4907	<	int cap = MIN_SEGMENT_TABLE_CAPACITY;
4908	<	final Segment<K,V>[] segments = this.segments;
4909	<	for (int k = 0; k < segments.length; ++k) {
4910	<	Segment<K,V> seg = segments[k];
4911	<	if (seg != null) {
4912	<	seg.threshold = (int)(cap * seg.loadFactor);
4913	<	seg.table = (HashEntry<K,V>[]) new HashEntry<?,?>[cap];
4906	>	@SuppressWarnings("serial")
4907	>	static final class ForEachValueTask<K,V>
4908	>	extends BulkTask<K,V,Void> {
4909	>	final Consumer<? super V> action;
4910	>	ForEachValueTask
4911	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4912	>	Consumer<? super V> action) {
4913	>	super(p, b, i, f, t);
4914	>	this.action = action;
4915	>	}
4916	>	public final void compute() {
4917	>	final Consumer<? super V> action;
4918	>	if ((action = this.action) != null) {
4919	>	for (int i = baseIndex, f, h; batch > 0 &&
4920	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4921	>	addToPendingCount(1);
4922	>	new ForEachValueTask<K,V>
4923	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4924	>	action).fork();
4925	>	}
4926	>	for (Node<K,V> p; (p = advance()) != null;)
4927	>	action.accept(p.val);
4928	>	propagateCompletion();
4929		}
4930		}
4931	+	}
4932
4933	<	// Read the keys and values, and put the mappings in the table
4934	<	for (;;) {
4935	<	K key = (K) s.readObject();
4936	<	V value = (V) s.readObject();
4937	<	if (key == null)
4938	<	break;
4939	<	put(key, value);
4933	>	@SuppressWarnings("serial")
4934	>	static final class ForEachEntryTask<K,V>
4935	>	extends BulkTask<K,V,Void> {
4936	>	final Consumer<? super Entry<K,V>> action;
4937	>	ForEachEntryTask
4938	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4939	>	Consumer<? super Entry<K,V>> action) {
4940	>	super(p, b, i, f, t);
4941	>	this.action = action;
4942	>	}
4943	>	public final void compute() {
4944	>	final Consumer<? super Entry<K,V>> action;
4945	>	if ((action = this.action) != null) {
4946	>	for (int i = baseIndex, f, h; batch > 0 &&
4947	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4948	>	addToPendingCount(1);
4949	>	new ForEachEntryTask<K,V>
4950	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4951	>	action).fork();
4952	>	}
4953	>	for (Node<K,V> p; (p = advance()) != null; )
4954	>	action.accept(p);
4955	>	propagateCompletion();
4956	>	}
4957	>	}
4958	>	}
4959	>
4960	>	@SuppressWarnings("serial")
4961	>	static final class ForEachMappingTask<K,V>
4962	>	extends BulkTask<K,V,Void> {
4963	>	final BiConsumer<? super K, ? super V> action;
4964	>	ForEachMappingTask
4965	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4966	>	BiConsumer<? super K,? super V> action) {
4967	>	super(p, b, i, f, t);
4968	>	this.action = action;
4969	>	}
4970	>	public final void compute() {
4971	>	final BiConsumer<? super K, ? super V> action;
4972	>	if ((action = this.action) != null) {
4973	>	for (int i = baseIndex, f, h; batch > 0 &&
4974	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
4975	>	addToPendingCount(1);
4976	>	new ForEachMappingTask<K,V>
4977	>	(this, batch >>>= 1, baseLimit = h, f, tab,
4978	>	action).fork();
4979	>	}
4980	>	for (Node<K,V> p; (p = advance()) != null; )
4981	>	action.accept(p.key, p.val);
4982	>	propagateCompletion();
4983	>	}
4984	>	}
4985	>	}
4986	>
4987	>	@SuppressWarnings("serial")
4988	>	static final class ForEachTransformedKeyTask<K,V,U>
4989	>	extends BulkTask<K,V,Void> {
4990	>	final Function<? super K, ? extends U> transformer;
4991	>	final Consumer<? super U> action;
4992	>	ForEachTransformedKeyTask
4993	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
4994	>	Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
4995	>	super(p, b, i, f, t);
4996	>	this.transformer = transformer; this.action = action;
4997	>	}
4998	>	public final void compute() {
4999	>	final Function<? super K, ? extends U> transformer;
5000	>	final Consumer<? super U> action;
5001	>	if ((transformer = this.transformer) != null &&
5002	>	(action = this.action) != null) {
5003	>	for (int i = baseIndex, f, h; batch > 0 &&
5004	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5005	>	addToPendingCount(1);
5006	>	new ForEachTransformedKeyTask<K,V,U>
5007	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5008	>	transformer, action).fork();
5009	>	}
5010	>	for (Node<K,V> p; (p = advance()) != null; ) {
5011	>	U u;
5012	>	if ((u = transformer.apply(p.key)) != null)
5013	>	action.accept(u);
5014	>	}
5015	>	propagateCompletion();
5016	>	}
5017	>	}
5018	>	}
5019	>
5020	>	@SuppressWarnings("serial")
5021	>	static final class ForEachTransformedValueTask<K,V,U>
5022	>	extends BulkTask<K,V,Void> {
5023	>	final Function<? super V, ? extends U> transformer;
5024	>	final Consumer<? super U> action;
5025	>	ForEachTransformedValueTask
5026	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5027	>	Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
5028	>	super(p, b, i, f, t);
5029	>	this.transformer = transformer; this.action = action;
5030	>	}
5031	>	public final void compute() {
5032	>	final Function<? super V, ? extends U> transformer;
5033	>	final Consumer<? super U> action;
5034	>	if ((transformer = this.transformer) != null &&
5035	>	(action = this.action) != null) {
5036	>	for (int i = baseIndex, f, h; batch > 0 &&
5037	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5038	>	addToPendingCount(1);
5039	>	new ForEachTransformedValueTask<K,V,U>
5040	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5041	>	transformer, action).fork();
5042	>	}
5043	>	for (Node<K,V> p; (p = advance()) != null; ) {
5044	>	U u;
5045	>	if ((u = transformer.apply(p.val)) != null)
5046	>	action.accept(u);
5047	>	}
5048	>	propagateCompletion();
5049	>	}
5050	>	}
5051	>	}
5052	>
5053	>	@SuppressWarnings("serial")
5054	>	static final class ForEachTransformedEntryTask<K,V,U>
5055	>	extends BulkTask<K,V,Void> {
5056	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5057	>	final Consumer<? super U> action;
5058	>	ForEachTransformedEntryTask
5059	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5060	>	Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
5061	>	super(p, b, i, f, t);
5062	>	this.transformer = transformer; this.action = action;
5063	>	}
5064	>	public final void compute() {
5065	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5066	>	final Consumer<? super U> action;
5067	>	if ((transformer = this.transformer) != null &&
5068	>	(action = this.action) != null) {
5069	>	for (int i = baseIndex, f, h; batch > 0 &&
5070	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5071	>	addToPendingCount(1);
5072	>	new ForEachTransformedEntryTask<K,V,U>
5073	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5074	>	transformer, action).fork();
5075	>	}
5076	>	for (Node<K,V> p; (p = advance()) != null; ) {
5077	>	U u;
5078	>	if ((u = transformer.apply(p)) != null)
5079	>	action.accept(u);
5080	>	}
5081	>	propagateCompletion();
5082	>	}
5083	>	}
5084	>	}
5085	>
5086	>	@SuppressWarnings("serial")
5087	>	static final class ForEachTransformedMappingTask<K,V,U>
5088	>	extends BulkTask<K,V,Void> {
5089	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5090	>	final Consumer<? super U> action;
5091	>	ForEachTransformedMappingTask
5092	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5093	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5094	>	Consumer<? super U> action) {
5095	>	super(p, b, i, f, t);
5096	>	this.transformer = transformer; this.action = action;
5097	>	}
5098	>	public final void compute() {
5099	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5100	>	final Consumer<? super U> action;
5101	>	if ((transformer = this.transformer) != null &&
5102	>	(action = this.action) != null) {
5103	>	for (int i = baseIndex, f, h; batch > 0 &&
5104	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5105	>	addToPendingCount(1);
5106	>	new ForEachTransformedMappingTask<K,V,U>
5107	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5108	>	transformer, action).fork();
5109	>	}
5110	>	for (Node<K,V> p; (p = advance()) != null; ) {
5111	>	U u;
5112	>	if ((u = transformer.apply(p.key, p.val)) != null)
5113	>	action.accept(u);
5114	>	}
5115	>	propagateCompletion();
5116	>	}
5117	>	}
5118	>	}
5119	>
5120	>	@SuppressWarnings("serial")
5121	>	static final class SearchKeysTask<K,V,U>
5122	>	extends BulkTask<K,V,U> {
5123	>	final Function<? super K, ? extends U> searchFunction;
5124	>	final AtomicReference<U> result;
5125	>	SearchKeysTask
5126	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5127	>	Function<? super K, ? extends U> searchFunction,
5128	>	AtomicReference<U> result) {
5129	>	super(p, b, i, f, t);
5130	>	this.searchFunction = searchFunction; this.result = result;
5131	>	}
5132	>	public final U getRawResult() { return result.get(); }
5133	>	public final void compute() {
5134	>	final Function<? super K, ? extends U> searchFunction;
5135	>	final AtomicReference<U> result;
5136	>	if ((searchFunction = this.searchFunction) != null &&
5137	>	(result = this.result) != null) {
5138	>	for (int i = baseIndex, f, h; batch > 0 &&
5139	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5140	>	if (result.get() != null)
5141	>	return;
5142	>	addToPendingCount(1);
5143	>	new SearchKeysTask<K,V,U>
5144	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5145	>	searchFunction, result).fork();
5146	>	}
5147	>	while (result.get() == null) {
5148	>	U u;
5149	>	Node<K,V> p;
5150	>	if ((p = advance()) == null) {
5151	>	propagateCompletion();
5152	>	break;
5153	>	}
5154	>	if ((u = searchFunction.apply(p.key)) != null) {
5155	>	if (result.compareAndSet(null, u))
5156	>	quietlyCompleteRoot();
5157	>	break;
5158	>	}
5159	>	}
5160	>	}
5161	>	}
5162	>	}
5163	>
5164	>	@SuppressWarnings("serial")
5165	>	static final class SearchValuesTask<K,V,U>
5166	>	extends BulkTask<K,V,U> {
5167	>	final Function<? super V, ? extends U> searchFunction;
5168	>	final AtomicReference<U> result;
5169	>	SearchValuesTask
5170	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5171	>	Function<? super V, ? extends U> searchFunction,
5172	>	AtomicReference<U> result) {
5173	>	super(p, b, i, f, t);
5174	>	this.searchFunction = searchFunction; this.result = result;
5175	>	}
5176	>	public final U getRawResult() { return result.get(); }
5177	>	public final void compute() {
5178	>	final Function<? super V, ? extends U> searchFunction;
5179	>	final AtomicReference<U> result;
5180	>	if ((searchFunction = this.searchFunction) != null &&
5181	>	(result = this.result) != null) {
5182	>	for (int i = baseIndex, f, h; batch > 0 &&
5183	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5184	>	if (result.get() != null)
5185	>	return;
5186	>	addToPendingCount(1);
5187	>	new SearchValuesTask<K,V,U>
5188	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5189	>	searchFunction, result).fork();
5190	>	}
5191	>	while (result.get() == null) {
5192	>	U u;
5193	>	Node<K,V> p;
5194	>	if ((p = advance()) == null) {
5195	>	propagateCompletion();
5196	>	break;
5197	>	}
5198	>	if ((u = searchFunction.apply(p.val)) != null) {
5199	>	if (result.compareAndSet(null, u))
5200	>	quietlyCompleteRoot();
5201	>	break;
5202	>	}
5203	>	}
5204	>	}
5205	>	}
5206	>	}
5207	>
5208	>	@SuppressWarnings("serial")
5209	>	static final class SearchEntriesTask<K,V,U>
5210	>	extends BulkTask<K,V,U> {
5211	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5212	>	final AtomicReference<U> result;
5213	>	SearchEntriesTask
5214	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5215	>	Function<Entry<K,V>, ? extends U> searchFunction,
5216	>	AtomicReference<U> result) {
5217	>	super(p, b, i, f, t);
5218	>	this.searchFunction = searchFunction; this.result = result;
5219	>	}
5220	>	public final U getRawResult() { return result.get(); }
5221	>	public final void compute() {
5222	>	final Function<Entry<K,V>, ? extends U> searchFunction;
5223	>	final AtomicReference<U> result;
5224	>	if ((searchFunction = this.searchFunction) != null &&
5225	>	(result = this.result) != null) {
5226	>	for (int i = baseIndex, f, h; batch > 0 &&
5227	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5228	>	if (result.get() != null)
5229	>	return;
5230	>	addToPendingCount(1);
5231	>	new SearchEntriesTask<K,V,U>
5232	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5233	>	searchFunction, result).fork();
5234	>	}
5235	>	while (result.get() == null) {
5236	>	U u;
5237	>	Node<K,V> p;
5238	>	if ((p = advance()) == null) {
5239	>	propagateCompletion();
5240	>	break;
5241	>	}
5242	>	if ((u = searchFunction.apply(p)) != null) {
5243	>	if (result.compareAndSet(null, u))
5244	>	quietlyCompleteRoot();
5245	>	return;
5246	>	}
5247	>	}
5248	>	}
5249	>	}
5250	>	}
5251	>
5252	>	@SuppressWarnings("serial")
5253	>	static final class SearchMappingsTask<K,V,U>
5254	>	extends BulkTask<K,V,U> {
5255	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5256	>	final AtomicReference<U> result;
5257	>	SearchMappingsTask
5258	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5259	>	BiFunction<? super K, ? super V, ? extends U> searchFunction,
5260	>	AtomicReference<U> result) {
5261	>	super(p, b, i, f, t);
5262	>	this.searchFunction = searchFunction; this.result = result;
5263	>	}
5264	>	public final U getRawResult() { return result.get(); }
5265	>	public final void compute() {
5266	>	final BiFunction<? super K, ? super V, ? extends U> searchFunction;
5267	>	final AtomicReference<U> result;
5268	>	if ((searchFunction = this.searchFunction) != null &&
5269	>	(result = this.result) != null) {
5270	>	for (int i = baseIndex, f, h; batch > 0 &&
5271	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5272	>	if (result.get() != null)
5273	>	return;
5274	>	addToPendingCount(1);
5275	>	new SearchMappingsTask<K,V,U>
5276	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5277	>	searchFunction, result).fork();
5278	>	}
5279	>	while (result.get() == null) {
5280	>	U u;
5281	>	Node<K,V> p;
5282	>	if ((p = advance()) == null) {
5283	>	propagateCompletion();
5284	>	break;
5285	>	}
5286	>	if ((u = searchFunction.apply(p.key, p.val)) != null) {
5287	>	if (result.compareAndSet(null, u))
5288	>	quietlyCompleteRoot();
5289	>	break;
5290	>	}
5291	>	}
5292	>	}
5293	>	}
5294	>	}
5295	>
5296	>	@SuppressWarnings("serial")
5297	>	static final class ReduceKeysTask<K,V>
5298	>	extends BulkTask<K,V,K> {
5299	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5300	>	K result;
5301	>	ReduceKeysTask<K,V> rights, nextRight;
5302	>	ReduceKeysTask
5303	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5304	>	ReduceKeysTask<K,V> nextRight,
5305	>	BiFunction<? super K, ? super K, ? extends K> reducer) {
5306	>	super(p, b, i, f, t); this.nextRight = nextRight;
5307	>	this.reducer = reducer;
5308	>	}
5309	>	public final K getRawResult() { return result; }
5310	>	public final void compute() {
5311	>	final BiFunction<? super K, ? super K, ? extends K> reducer;
5312	>	if ((reducer = this.reducer) != null) {
5313	>	for (int i = baseIndex, f, h; batch > 0 &&
5314	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5315	>	addToPendingCount(1);
5316	>	(rights = new ReduceKeysTask<K,V>
5317	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5318	>	rights, reducer)).fork();
5319	>	}
5320	>	K r = null;
5321	>	for (Node<K,V> p; (p = advance()) != null; ) {
5322	>	K u = p.key;
5323	>	r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
5324	>	}
5325	>	result = r;
5326	>	CountedCompleter<?> c;
5327	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5328	>	@SuppressWarnings("unchecked")
5329	>	ReduceKeysTask<K,V>
5330	>	t = (ReduceKeysTask<K,V>)c,
5331	>	s = t.rights;
5332	>	while (s != null) {
5333	>	K tr, sr;
5334	>	if ((sr = s.result) != null)
5335	>	t.result = (((tr = t.result) == null) ? sr :
5336	>	reducer.apply(tr, sr));
5337	>	s = t.rights = s.nextRight;
5338	>	}
5339	>	}
5340	>	}
5341	>	}
5342	>	}
5343	>
5344	>	@SuppressWarnings("serial")
5345	>	static final class ReduceValuesTask<K,V>
5346	>	extends BulkTask<K,V,V> {
5347	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5348	>	V result;
5349	>	ReduceValuesTask<K,V> rights, nextRight;
5350	>	ReduceValuesTask
5351	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5352	>	ReduceValuesTask<K,V> nextRight,
5353	>	BiFunction<? super V, ? super V, ? extends V> reducer) {
5354	>	super(p, b, i, f, t); this.nextRight = nextRight;
5355	>	this.reducer = reducer;
5356	>	}
5357	>	public final V getRawResult() { return result; }
5358	>	public final void compute() {
5359	>	final BiFunction<? super V, ? super V, ? extends V> reducer;
5360	>	if ((reducer = this.reducer) != null) {
5361	>	for (int i = baseIndex, f, h; batch > 0 &&
5362	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5363	>	addToPendingCount(1);
5364	>	(rights = new ReduceValuesTask<K,V>
5365	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5366	>	rights, reducer)).fork();
5367	>	}
5368	>	V r = null;
5369	>	for (Node<K,V> p; (p = advance()) != null; ) {
5370	>	V v = p.val;
5371	>	r = (r == null) ? v : reducer.apply(r, v);
5372	>	}
5373	>	result = r;
5374	>	CountedCompleter<?> c;
5375	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5376	>	@SuppressWarnings("unchecked")
5377	>	ReduceValuesTask<K,V>
5378	>	t = (ReduceValuesTask<K,V>)c,
5379	>	s = t.rights;
5380	>	while (s != null) {
5381	>	V tr, sr;
5382	>	if ((sr = s.result) != null)
5383	>	t.result = (((tr = t.result) == null) ? sr :
5384	>	reducer.apply(tr, sr));
5385	>	s = t.rights = s.nextRight;
5386	>	}
5387	>	}
5388	>	}
5389	>	}
5390	>	}
5391	>
5392	>	@SuppressWarnings("serial")
5393	>	static final class ReduceEntriesTask<K,V>
5394	>	extends BulkTask<K,V,Map.Entry<K,V>> {
5395	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5396	>	Map.Entry<K,V> result;
5397	>	ReduceEntriesTask<K,V> rights, nextRight;
5398	>	ReduceEntriesTask
5399	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5400	>	ReduceEntriesTask<K,V> nextRight,
5401	>	BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
5402	>	super(p, b, i, f, t); this.nextRight = nextRight;
5403	>	this.reducer = reducer;
5404	>	}
5405	>	public final Map.Entry<K,V> getRawResult() { return result; }
5406	>	public final void compute() {
5407	>	final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
5408	>	if ((reducer = this.reducer) != null) {
5409	>	for (int i = baseIndex, f, h; batch > 0 &&
5410	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5411	>	addToPendingCount(1);
5412	>	(rights = new ReduceEntriesTask<K,V>
5413	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5414	>	rights, reducer)).fork();
5415	>	}
5416	>	Map.Entry<K,V> r = null;
5417	>	for (Node<K,V> p; (p = advance()) != null; )
5418	>	r = (r == null) ? p : reducer.apply(r, p);
5419	>	result = r;
5420	>	CountedCompleter<?> c;
5421	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5422	>	@SuppressWarnings("unchecked")
5423	>	ReduceEntriesTask<K,V>
5424	>	t = (ReduceEntriesTask<K,V>)c,
5425	>	s = t.rights;
5426	>	while (s != null) {
5427	>	Map.Entry<K,V> tr, sr;
5428	>	if ((sr = s.result) != null)
5429	>	t.result = (((tr = t.result) == null) ? sr :
5430	>	reducer.apply(tr, sr));
5431	>	s = t.rights = s.nextRight;
5432	>	}
5433	>	}
5434	>	}
5435	>	}
5436	>	}
5437	>
5438	>	@SuppressWarnings("serial")
5439	>	static final class MapReduceKeysTask<K,V,U>
5440	>	extends BulkTask<K,V,U> {
5441	>	final Function<? super K, ? extends U> transformer;
5442	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5443	>	U result;
5444	>	MapReduceKeysTask<K,V,U> rights, nextRight;
5445	>	MapReduceKeysTask
5446	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5447	>	MapReduceKeysTask<K,V,U> nextRight,
5448	>	Function<? super K, ? extends U> transformer,
5449	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5450	>	super(p, b, i, f, t); this.nextRight = nextRight;
5451	>	this.transformer = transformer;
5452	>	this.reducer = reducer;
5453	>	}
5454	>	public final U getRawResult() { return result; }
5455	>	public final void compute() {
5456	>	final Function<? super K, ? extends U> transformer;
5457	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5458	>	if ((transformer = this.transformer) != null &&
5459	>	(reducer = this.reducer) != null) {
5460	>	for (int i = baseIndex, f, h; batch > 0 &&
5461	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5462	>	addToPendingCount(1);
5463	>	(rights = new MapReduceKeysTask<K,V,U>
5464	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5465	>	rights, transformer, reducer)).fork();
5466	>	}
5467	>	U r = null;
5468	>	for (Node<K,V> p; (p = advance()) != null; ) {
5469	>	U u;
5470	>	if ((u = transformer.apply(p.key)) != null)
5471	>	r = (r == null) ? u : reducer.apply(r, u);
5472	>	}
5473	>	result = r;
5474	>	CountedCompleter<?> c;
5475	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5476	>	@SuppressWarnings("unchecked")
5477	>	MapReduceKeysTask<K,V,U>
5478	>	t = (MapReduceKeysTask<K,V,U>)c,
5479	>	s = t.rights;
5480	>	while (s != null) {
5481	>	U tr, sr;
5482	>	if ((sr = s.result) != null)
5483	>	t.result = (((tr = t.result) == null) ? sr :
5484	>	reducer.apply(tr, sr));
5485	>	s = t.rights = s.nextRight;
5486	>	}
5487	>	}
5488	>	}
5489	>	}
5490	>	}
5491	>
5492	>	@SuppressWarnings("serial")
5493	>	static final class MapReduceValuesTask<K,V,U>
5494	>	extends BulkTask<K,V,U> {
5495	>	final Function<? super V, ? extends U> transformer;
5496	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5497	>	U result;
5498	>	MapReduceValuesTask<K,V,U> rights, nextRight;
5499	>	MapReduceValuesTask
5500	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5501	>	MapReduceValuesTask<K,V,U> nextRight,
5502	>	Function<? super V, ? extends U> transformer,
5503	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5504	>	super(p, b, i, f, t); this.nextRight = nextRight;
5505	>	this.transformer = transformer;
5506	>	this.reducer = reducer;
5507	>	}
5508	>	public final U getRawResult() { return result; }
5509	>	public final void compute() {
5510	>	final Function<? super V, ? extends U> transformer;
5511	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5512	>	if ((transformer = this.transformer) != null &&
5513	>	(reducer = this.reducer) != null) {
5514	>	for (int i = baseIndex, f, h; batch > 0 &&
5515	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5516	>	addToPendingCount(1);
5517	>	(rights = new MapReduceValuesTask<K,V,U>
5518	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5519	>	rights, transformer, reducer)).fork();
5520	>	}
5521	>	U r = null;
5522	>	for (Node<K,V> p; (p = advance()) != null; ) {
5523	>	U u;
5524	>	if ((u = transformer.apply(p.val)) != null)
5525	>	r = (r == null) ? u : reducer.apply(r, u);
5526	>	}
5527	>	result = r;
5528	>	CountedCompleter<?> c;
5529	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5530	>	@SuppressWarnings("unchecked")
5531	>	MapReduceValuesTask<K,V,U>
5532	>	t = (MapReduceValuesTask<K,V,U>)c,
5533	>	s = t.rights;
5534	>	while (s != null) {
5535	>	U tr, sr;
5536	>	if ((sr = s.result) != null)
5537	>	t.result = (((tr = t.result) == null) ? sr :
5538	>	reducer.apply(tr, sr));
5539	>	s = t.rights = s.nextRight;
5540	>	}
5541	>	}
5542	>	}
5543	>	}
5544	>	}
5545	>
5546	>	@SuppressWarnings("serial")
5547	>	static final class MapReduceEntriesTask<K,V,U>
5548	>	extends BulkTask<K,V,U> {
5549	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5550	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5551	>	U result;
5552	>	MapReduceEntriesTask<K,V,U> rights, nextRight;
5553	>	MapReduceEntriesTask
5554	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5555	>	MapReduceEntriesTask<K,V,U> nextRight,
5556	>	Function<Map.Entry<K,V>, ? extends U> transformer,
5557	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5558	>	super(p, b, i, f, t); this.nextRight = nextRight;
5559	>	this.transformer = transformer;
5560	>	this.reducer = reducer;
5561	>	}
5562	>	public final U getRawResult() { return result; }
5563	>	public final void compute() {
5564	>	final Function<Map.Entry<K,V>, ? extends U> transformer;
5565	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5566	>	if ((transformer = this.transformer) != null &&
5567	>	(reducer = this.reducer) != null) {
5568	>	for (int i = baseIndex, f, h; batch > 0 &&
5569	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5570	>	addToPendingCount(1);
5571	>	(rights = new MapReduceEntriesTask<K,V,U>
5572	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5573	>	rights, transformer, reducer)).fork();
5574	>	}
5575	>	U r = null;
5576	>	for (Node<K,V> p; (p = advance()) != null; ) {
5577	>	U u;
5578	>	if ((u = transformer.apply(p)) != null)
5579	>	r = (r == null) ? u : reducer.apply(r, u);
5580	>	}
5581	>	result = r;
5582	>	CountedCompleter<?> c;
5583	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5584	>	@SuppressWarnings("unchecked")
5585	>	MapReduceEntriesTask<K,V,U>
5586	>	t = (MapReduceEntriesTask<K,V,U>)c,
5587	>	s = t.rights;
5588	>	while (s != null) {
5589	>	U tr, sr;
5590	>	if ((sr = s.result) != null)
5591	>	t.result = (((tr = t.result) == null) ? sr :
5592	>	reducer.apply(tr, sr));
5593	>	s = t.rights = s.nextRight;
5594	>	}
5595	>	}
5596	>	}
5597	>	}
5598	>	}
5599	>
5600	>	@SuppressWarnings("serial")
5601	>	static final class MapReduceMappingsTask<K,V,U>
5602	>	extends BulkTask<K,V,U> {
5603	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5604	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5605	>	U result;
5606	>	MapReduceMappingsTask<K,V,U> rights, nextRight;
5607	>	MapReduceMappingsTask
5608	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5609	>	MapReduceMappingsTask<K,V,U> nextRight,
5610	>	BiFunction<? super K, ? super V, ? extends U> transformer,
5611	>	BiFunction<? super U, ? super U, ? extends U> reducer) {
5612	>	super(p, b, i, f, t); this.nextRight = nextRight;
5613	>	this.transformer = transformer;
5614	>	this.reducer = reducer;
5615	>	}
5616	>	public final U getRawResult() { return result; }
5617	>	public final void compute() {
5618	>	final BiFunction<? super K, ? super V, ? extends U> transformer;
5619	>	final BiFunction<? super U, ? super U, ? extends U> reducer;
5620	>	if ((transformer = this.transformer) != null &&
5621	>	(reducer = this.reducer) != null) {
5622	>	for (int i = baseIndex, f, h; batch > 0 &&
5623	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5624	>	addToPendingCount(1);
5625	>	(rights = new MapReduceMappingsTask<K,V,U>
5626	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5627	>	rights, transformer, reducer)).fork();
5628	>	}
5629	>	U r = null;
5630	>	for (Node<K,V> p; (p = advance()) != null; ) {
5631	>	U u;
5632	>	if ((u = transformer.apply(p.key, p.val)) != null)
5633	>	r = (r == null) ? u : reducer.apply(r, u);
5634	>	}
5635	>	result = r;
5636	>	CountedCompleter<?> c;
5637	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5638	>	@SuppressWarnings("unchecked")
5639	>	MapReduceMappingsTask<K,V,U>
5640	>	t = (MapReduceMappingsTask<K,V,U>)c,
5641	>	s = t.rights;
5642	>	while (s != null) {
5643	>	U tr, sr;
5644	>	if ((sr = s.result) != null)
5645	>	t.result = (((tr = t.result) == null) ? sr :
5646	>	reducer.apply(tr, sr));
5647	>	s = t.rights = s.nextRight;
5648	>	}
5649	>	}
5650	>	}
5651	>	}
5652	>	}
5653	>
5654	>	@SuppressWarnings("serial")
5655	>	static final class MapReduceKeysToDoubleTask<K,V>
5656	>	extends BulkTask<K,V,Double> {
5657	>	final ToDoubleFunction<? super K> transformer;
5658	>	final DoubleBinaryOperator reducer;
5659	>	final double basis;
5660	>	double result;
5661	>	MapReduceKeysToDoubleTask<K,V> rights, nextRight;
5662	>	MapReduceKeysToDoubleTask
5663	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5664	>	MapReduceKeysToDoubleTask<K,V> nextRight,
5665	>	ToDoubleFunction<? super K> transformer,
5666	>	double basis,
5667	>	DoubleBinaryOperator reducer) {
5668	>	super(p, b, i, f, t); this.nextRight = nextRight;
5669	>	this.transformer = transformer;
5670	>	this.basis = basis; this.reducer = reducer;
5671	>	}
5672	>	public final Double getRawResult() { return result; }
5673	>	public final void compute() {
5674	>	final ToDoubleFunction<? super K> transformer;
5675	>	final DoubleBinaryOperator reducer;
5676	>	if ((transformer = this.transformer) != null &&
5677	>	(reducer = this.reducer) != null) {
5678	>	double r = this.basis;
5679	>	for (int i = baseIndex, f, h; batch > 0 &&
5680	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5681	>	addToPendingCount(1);
5682	>	(rights = new MapReduceKeysToDoubleTask<K,V>
5683	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5684	>	rights, transformer, r, reducer)).fork();
5685	>	}
5686	>	for (Node<K,V> p; (p = advance()) != null; )
5687	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
5688	>	result = r;
5689	>	CountedCompleter<?> c;
5690	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5691	>	@SuppressWarnings("unchecked")
5692	>	MapReduceKeysToDoubleTask<K,V>
5693	>	t = (MapReduceKeysToDoubleTask<K,V>)c,
5694	>	s = t.rights;
5695	>	while (s != null) {
5696	>	t.result = reducer.applyAsDouble(t.result, s.result);
5697	>	s = t.rights = s.nextRight;
5698	>	}
5699	>	}
5700	>	}
5701	>	}
5702	>	}
5703	>
5704	>	@SuppressWarnings("serial")
5705	>	static final class MapReduceValuesToDoubleTask<K,V>
5706	>	extends BulkTask<K,V,Double> {
5707	>	final ToDoubleFunction<? super V> transformer;
5708	>	final DoubleBinaryOperator reducer;
5709	>	final double basis;
5710	>	double result;
5711	>	MapReduceValuesToDoubleTask<K,V> rights, nextRight;
5712	>	MapReduceValuesToDoubleTask
5713	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5714	>	MapReduceValuesToDoubleTask<K,V> nextRight,
5715	>	ToDoubleFunction<? super V> transformer,
5716	>	double basis,
5717	>	DoubleBinaryOperator reducer) {
5718	>	super(p, b, i, f, t); this.nextRight = nextRight;
5719	>	this.transformer = transformer;
5720	>	this.basis = basis; this.reducer = reducer;
5721	>	}
5722	>	public final Double getRawResult() { return result; }
5723	>	public final void compute() {
5724	>	final ToDoubleFunction<? super V> transformer;
5725	>	final DoubleBinaryOperator reducer;
5726	>	if ((transformer = this.transformer) != null &&
5727	>	(reducer = this.reducer) != null) {
5728	>	double r = this.basis;
5729	>	for (int i = baseIndex, f, h; batch > 0 &&
5730	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5731	>	addToPendingCount(1);
5732	>	(rights = new MapReduceValuesToDoubleTask<K,V>
5733	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5734	>	rights, transformer, r, reducer)).fork();
5735	>	}
5736	>	for (Node<K,V> p; (p = advance()) != null; )
5737	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
5738	>	result = r;
5739	>	CountedCompleter<?> c;
5740	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5741	>	@SuppressWarnings("unchecked")
5742	>	MapReduceValuesToDoubleTask<K,V>
5743	>	t = (MapReduceValuesToDoubleTask<K,V>)c,
5744	>	s = t.rights;
5745	>	while (s != null) {
5746	>	t.result = reducer.applyAsDouble(t.result, s.result);
5747	>	s = t.rights = s.nextRight;
5748	>	}
5749	>	}
5750	>	}
5751	>	}
5752	>	}
5753	>
5754	>	@SuppressWarnings("serial")
5755	>	static final class MapReduceEntriesToDoubleTask<K,V>
5756	>	extends BulkTask<K,V,Double> {
5757	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5758	>	final DoubleBinaryOperator reducer;
5759	>	final double basis;
5760	>	double result;
5761	>	MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
5762	>	MapReduceEntriesToDoubleTask
5763	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5764	>	MapReduceEntriesToDoubleTask<K,V> nextRight,
5765	>	ToDoubleFunction<Map.Entry<K,V>> transformer,
5766	>	double basis,
5767	>	DoubleBinaryOperator reducer) {
5768	>	super(p, b, i, f, t); this.nextRight = nextRight;
5769	>	this.transformer = transformer;
5770	>	this.basis = basis; this.reducer = reducer;
5771	>	}
5772	>	public final Double getRawResult() { return result; }
5773	>	public final void compute() {
5774	>	final ToDoubleFunction<Map.Entry<K,V>> transformer;
5775	>	final DoubleBinaryOperator reducer;
5776	>	if ((transformer = this.transformer) != null &&
5777	>	(reducer = this.reducer) != null) {
5778	>	double r = this.basis;
5779	>	for (int i = baseIndex, f, h; batch > 0 &&
5780	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5781	>	addToPendingCount(1);
5782	>	(rights = new MapReduceEntriesToDoubleTask<K,V>
5783	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5784	>	rights, transformer, r, reducer)).fork();
5785	>	}
5786	>	for (Node<K,V> p; (p = advance()) != null; )
5787	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
5788	>	result = r;
5789	>	CountedCompleter<?> c;
5790	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5791	>	@SuppressWarnings("unchecked")
5792	>	MapReduceEntriesToDoubleTask<K,V>
5793	>	t = (MapReduceEntriesToDoubleTask<K,V>)c,
5794	>	s = t.rights;
5795	>	while (s != null) {
5796	>	t.result = reducer.applyAsDouble(t.result, s.result);
5797	>	s = t.rights = s.nextRight;
5798	>	}
5799	>	}
5800	>	}
5801	>	}
5802	>	}
5803	>
5804	>	@SuppressWarnings("serial")
5805	>	static final class MapReduceMappingsToDoubleTask<K,V>
5806	>	extends BulkTask<K,V,Double> {
5807	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5808	>	final DoubleBinaryOperator reducer;
5809	>	final double basis;
5810	>	double result;
5811	>	MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
5812	>	MapReduceMappingsToDoubleTask
5813	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5814	>	MapReduceMappingsToDoubleTask<K,V> nextRight,
5815	>	ToDoubleBiFunction<? super K, ? super V> transformer,
5816	>	double basis,
5817	>	DoubleBinaryOperator reducer) {
5818	>	super(p, b, i, f, t); this.nextRight = nextRight;
5819	>	this.transformer = transformer;
5820	>	this.basis = basis; this.reducer = reducer;
5821	>	}
5822	>	public final Double getRawResult() { return result; }
5823	>	public final void compute() {
5824	>	final ToDoubleBiFunction<? super K, ? super V> transformer;
5825	>	final DoubleBinaryOperator reducer;
5826	>	if ((transformer = this.transformer) != null &&
5827	>	(reducer = this.reducer) != null) {
5828	>	double r = this.basis;
5829	>	for (int i = baseIndex, f, h; batch > 0 &&
5830	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5831	>	addToPendingCount(1);
5832	>	(rights = new MapReduceMappingsToDoubleTask<K,V>
5833	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5834	>	rights, transformer, r, reducer)).fork();
5835	>	}
5836	>	for (Node<K,V> p; (p = advance()) != null; )
5837	>	r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
5838	>	result = r;
5839	>	CountedCompleter<?> c;
5840	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5841	>	@SuppressWarnings("unchecked")
5842	>	MapReduceMappingsToDoubleTask<K,V>
5843	>	t = (MapReduceMappingsToDoubleTask<K,V>)c,
5844	>	s = t.rights;
5845	>	while (s != null) {
5846	>	t.result = reducer.applyAsDouble(t.result, s.result);
5847	>	s = t.rights = s.nextRight;
5848	>	}
5849	>	}
5850	>	}
5851	>	}
5852	>	}
5853	>
5854	>	@SuppressWarnings("serial")
5855	>	static final class MapReduceKeysToLongTask<K,V>
5856	>	extends BulkTask<K,V,Long> {
5857	>	final ToLongFunction<? super K> transformer;
5858	>	final LongBinaryOperator reducer;
5859	>	final long basis;
5860	>	long result;
5861	>	MapReduceKeysToLongTask<K,V> rights, nextRight;
5862	>	MapReduceKeysToLongTask
5863	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5864	>	MapReduceKeysToLongTask<K,V> nextRight,
5865	>	ToLongFunction<? super K> transformer,
5866	>	long basis,
5867	>	LongBinaryOperator reducer) {
5868	>	super(p, b, i, f, t); this.nextRight = nextRight;
5869	>	this.transformer = transformer;
5870	>	this.basis = basis; this.reducer = reducer;
5871	>	}
5872	>	public final Long getRawResult() { return result; }
5873	>	public final void compute() {
5874	>	final ToLongFunction<? super K> transformer;
5875	>	final LongBinaryOperator reducer;
5876	>	if ((transformer = this.transformer) != null &&
5877	>	(reducer = this.reducer) != null) {
5878	>	long r = this.basis;
5879	>	for (int i = baseIndex, f, h; batch > 0 &&
5880	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5881	>	addToPendingCount(1);
5882	>	(rights = new MapReduceKeysToLongTask<K,V>
5883	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5884	>	rights, transformer, r, reducer)).fork();
5885	>	}
5886	>	for (Node<K,V> p; (p = advance()) != null; )
5887	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
5888	>	result = r;
5889	>	CountedCompleter<?> c;
5890	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5891	>	@SuppressWarnings("unchecked")
5892	>	MapReduceKeysToLongTask<K,V>
5893	>	t = (MapReduceKeysToLongTask<K,V>)c,
5894	>	s = t.rights;
5895	>	while (s != null) {
5896	>	t.result = reducer.applyAsLong(t.result, s.result);
5897	>	s = t.rights = s.nextRight;
5898	>	}
5899	>	}
5900	>	}
5901	>	}
5902	>	}
5903	>
5904	>	@SuppressWarnings("serial")
5905	>	static final class MapReduceValuesToLongTask<K,V>
5906	>	extends BulkTask<K,V,Long> {
5907	>	final ToLongFunction<? super V> transformer;
5908	>	final LongBinaryOperator reducer;
5909	>	final long basis;
5910	>	long result;
5911	>	MapReduceValuesToLongTask<K,V> rights, nextRight;
5912	>	MapReduceValuesToLongTask
5913	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5914	>	MapReduceValuesToLongTask<K,V> nextRight,
5915	>	ToLongFunction<? super V> transformer,
5916	>	long basis,
5917	>	LongBinaryOperator reducer) {
5918	>	super(p, b, i, f, t); this.nextRight = nextRight;
5919	>	this.transformer = transformer;
5920	>	this.basis = basis; this.reducer = reducer;
5921	>	}
5922	>	public final Long getRawResult() { return result; }
5923	>	public final void compute() {
5924	>	final ToLongFunction<? super V> transformer;
5925	>	final LongBinaryOperator reducer;
5926	>	if ((transformer = this.transformer) != null &&
5927	>	(reducer = this.reducer) != null) {
5928	>	long r = this.basis;
5929	>	for (int i = baseIndex, f, h; batch > 0 &&
5930	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5931	>	addToPendingCount(1);
5932	>	(rights = new MapReduceValuesToLongTask<K,V>
5933	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5934	>	rights, transformer, r, reducer)).fork();
5935	>	}
5936	>	for (Node<K,V> p; (p = advance()) != null; )
5937	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
5938	>	result = r;
5939	>	CountedCompleter<?> c;
5940	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5941	>	@SuppressWarnings("unchecked")
5942	>	MapReduceValuesToLongTask<K,V>
5943	>	t = (MapReduceValuesToLongTask<K,V>)c,
5944	>	s = t.rights;
5945	>	while (s != null) {
5946	>	t.result = reducer.applyAsLong(t.result, s.result);
5947	>	s = t.rights = s.nextRight;
5948	>	}
5949	>	}
5950	>	}
5951	>	}
5952	>	}
5953	>
5954	>	@SuppressWarnings("serial")
5955	>	static final class MapReduceEntriesToLongTask<K,V>
5956	>	extends BulkTask<K,V,Long> {
5957	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5958	>	final LongBinaryOperator reducer;
5959	>	final long basis;
5960	>	long result;
5961	>	MapReduceEntriesToLongTask<K,V> rights, nextRight;
5962	>	MapReduceEntriesToLongTask
5963	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
5964	>	MapReduceEntriesToLongTask<K,V> nextRight,
5965	>	ToLongFunction<Map.Entry<K,V>> transformer,
5966	>	long basis,
5967	>	LongBinaryOperator reducer) {
5968	>	super(p, b, i, f, t); this.nextRight = nextRight;
5969	>	this.transformer = transformer;
5970	>	this.basis = basis; this.reducer = reducer;
5971	>	}
5972	>	public final Long getRawResult() { return result; }
5973	>	public final void compute() {
5974	>	final ToLongFunction<Map.Entry<K,V>> transformer;
5975	>	final LongBinaryOperator reducer;
5976	>	if ((transformer = this.transformer) != null &&
5977	>	(reducer = this.reducer) != null) {
5978	>	long r = this.basis;
5979	>	for (int i = baseIndex, f, h; batch > 0 &&
5980	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
5981	>	addToPendingCount(1);
5982	>	(rights = new MapReduceEntriesToLongTask<K,V>
5983	>	(this, batch >>>= 1, baseLimit = h, f, tab,
5984	>	rights, transformer, r, reducer)).fork();
5985	>	}
5986	>	for (Node<K,V> p; (p = advance()) != null; )
5987	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p));
5988	>	result = r;
5989	>	CountedCompleter<?> c;
5990	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
5991	>	@SuppressWarnings("unchecked")
5992	>	MapReduceEntriesToLongTask<K,V>
5993	>	t = (MapReduceEntriesToLongTask<K,V>)c,
5994	>	s = t.rights;
5995	>	while (s != null) {
5996	>	t.result = reducer.applyAsLong(t.result, s.result);
5997	>	s = t.rights = s.nextRight;
5998	>	}
5999	>	}
6000	>	}
6001	>	}
6002	>	}
6003	>
6004	>	@SuppressWarnings("serial")
6005	>	static final class MapReduceMappingsToLongTask<K,V>
6006	>	extends BulkTask<K,V,Long> {
6007	>	final ToLongBiFunction<? super K, ? super V> transformer;
6008	>	final LongBinaryOperator reducer;
6009	>	final long basis;
6010	>	long result;
6011	>	MapReduceMappingsToLongTask<K,V> rights, nextRight;
6012	>	MapReduceMappingsToLongTask
6013	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6014	>	MapReduceMappingsToLongTask<K,V> nextRight,
6015	>	ToLongBiFunction<? super K, ? super V> transformer,
6016	>	long basis,
6017	>	LongBinaryOperator reducer) {
6018	>	super(p, b, i, f, t); this.nextRight = nextRight;
6019	>	this.transformer = transformer;
6020	>	this.basis = basis; this.reducer = reducer;
6021	>	}
6022	>	public final Long getRawResult() { return result; }
6023	>	public final void compute() {
6024	>	final ToLongBiFunction<? super K, ? super V> transformer;
6025	>	final LongBinaryOperator reducer;
6026	>	if ((transformer = this.transformer) != null &&
6027	>	(reducer = this.reducer) != null) {
6028	>	long r = this.basis;
6029	>	for (int i = baseIndex, f, h; batch > 0 &&
6030	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6031	>	addToPendingCount(1);
6032	>	(rights = new MapReduceMappingsToLongTask<K,V>
6033	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6034	>	rights, transformer, r, reducer)).fork();
6035	>	}
6036	>	for (Node<K,V> p; (p = advance()) != null; )
6037	>	r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
6038	>	result = r;
6039	>	CountedCompleter<?> c;
6040	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6041	>	@SuppressWarnings("unchecked")
6042	>	MapReduceMappingsToLongTask<K,V>
6043	>	t = (MapReduceMappingsToLongTask<K,V>)c,
6044	>	s = t.rights;
6045	>	while (s != null) {
6046	>	t.result = reducer.applyAsLong(t.result, s.result);
6047	>	s = t.rights = s.nextRight;
6048	>	}
6049	>	}
6050	>	}
6051	>	}
6052	>	}
6053	>
6054	>	@SuppressWarnings("serial")
6055	>	static final class MapReduceKeysToIntTask<K,V>
6056	>	extends BulkTask<K,V,Integer> {
6057	>	final ToIntFunction<? super K> transformer;
6058	>	final IntBinaryOperator reducer;
6059	>	final int basis;
6060	>	int result;
6061	>	MapReduceKeysToIntTask<K,V> rights, nextRight;
6062	>	MapReduceKeysToIntTask
6063	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6064	>	MapReduceKeysToIntTask<K,V> nextRight,
6065	>	ToIntFunction<? super K> transformer,
6066	>	int basis,
6067	>	IntBinaryOperator reducer) {
6068	>	super(p, b, i, f, t); this.nextRight = nextRight;
6069	>	this.transformer = transformer;
6070	>	this.basis = basis; this.reducer = reducer;
6071	>	}
6072	>	public final Integer getRawResult() { return result; }
6073	>	public final void compute() {
6074	>	final ToIntFunction<? super K> transformer;
6075	>	final IntBinaryOperator reducer;
6076	>	if ((transformer = this.transformer) != null &&
6077	>	(reducer = this.reducer) != null) {
6078	>	int r = this.basis;
6079	>	for (int i = baseIndex, f, h; batch > 0 &&
6080	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6081	>	addToPendingCount(1);
6082	>	(rights = new MapReduceKeysToIntTask<K,V>
6083	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6084	>	rights, transformer, r, reducer)).fork();
6085	>	}
6086	>	for (Node<K,V> p; (p = advance()) != null; )
6087	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
6088	>	result = r;
6089	>	CountedCompleter<?> c;
6090	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6091	>	@SuppressWarnings("unchecked")
6092	>	MapReduceKeysToIntTask<K,V>
6093	>	t = (MapReduceKeysToIntTask<K,V>)c,
6094	>	s = t.rights;
6095	>	while (s != null) {
6096	>	t.result = reducer.applyAsInt(t.result, s.result);
6097	>	s = t.rights = s.nextRight;
6098	>	}
6099	>	}
6100	>	}
6101	>	}
6102	>	}
6103	>
6104	>	@SuppressWarnings("serial")
6105	>	static final class MapReduceValuesToIntTask<K,V>
6106	>	extends BulkTask<K,V,Integer> {
6107	>	final ToIntFunction<? super V> transformer;
6108	>	final IntBinaryOperator reducer;
6109	>	final int basis;
6110	>	int result;
6111	>	MapReduceValuesToIntTask<K,V> rights, nextRight;
6112	>	MapReduceValuesToIntTask
6113	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6114	>	MapReduceValuesToIntTask<K,V> nextRight,
6115	>	ToIntFunction<? super V> transformer,
6116	>	int basis,
6117	>	IntBinaryOperator reducer) {
6118	>	super(p, b, i, f, t); this.nextRight = nextRight;
6119	>	this.transformer = transformer;
6120	>	this.basis = basis; this.reducer = reducer;
6121	>	}
6122	>	public final Integer getRawResult() { return result; }
6123	>	public final void compute() {
6124	>	final ToIntFunction<? super V> transformer;
6125	>	final IntBinaryOperator reducer;
6126	>	if ((transformer = this.transformer) != null &&
6127	>	(reducer = this.reducer) != null) {
6128	>	int r = this.basis;
6129	>	for (int i = baseIndex, f, h; batch > 0 &&
6130	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6131	>	addToPendingCount(1);
6132	>	(rights = new MapReduceValuesToIntTask<K,V>
6133	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6134	>	rights, transformer, r, reducer)).fork();
6135	>	}
6136	>	for (Node<K,V> p; (p = advance()) != null; )
6137	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
6138	>	result = r;
6139	>	CountedCompleter<?> c;
6140	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6141	>	@SuppressWarnings("unchecked")
6142	>	MapReduceValuesToIntTask<K,V>
6143	>	t = (MapReduceValuesToIntTask<K,V>)c,
6144	>	s = t.rights;
6145	>	while (s != null) {
6146	>	t.result = reducer.applyAsInt(t.result, s.result);
6147	>	s = t.rights = s.nextRight;
6148	>	}
6149	>	}
6150	>	}
6151	>	}
6152	>	}
6153	>
6154	>	@SuppressWarnings("serial")
6155	>	static final class MapReduceEntriesToIntTask<K,V>
6156	>	extends BulkTask<K,V,Integer> {
6157	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6158	>	final IntBinaryOperator reducer;
6159	>	final int basis;
6160	>	int result;
6161	>	MapReduceEntriesToIntTask<K,V> rights, nextRight;
6162	>	MapReduceEntriesToIntTask
6163	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6164	>	MapReduceEntriesToIntTask<K,V> nextRight,
6165	>	ToIntFunction<Map.Entry<K,V>> transformer,
6166	>	int basis,
6167	>	IntBinaryOperator reducer) {
6168	>	super(p, b, i, f, t); this.nextRight = nextRight;
6169	>	this.transformer = transformer;
6170	>	this.basis = basis; this.reducer = reducer;
6171	>	}
6172	>	public final Integer getRawResult() { return result; }
6173	>	public final void compute() {
6174	>	final ToIntFunction<Map.Entry<K,V>> transformer;
6175	>	final IntBinaryOperator reducer;
6176	>	if ((transformer = this.transformer) != null &&
6177	>	(reducer = this.reducer) != null) {
6178	>	int r = this.basis;
6179	>	for (int i = baseIndex, f, h; batch > 0 &&
6180	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6181	>	addToPendingCount(1);
6182	>	(rights = new MapReduceEntriesToIntTask<K,V>
6183	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6184	>	rights, transformer, r, reducer)).fork();
6185	>	}
6186	>	for (Node<K,V> p; (p = advance()) != null; )
6187	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p));
6188	>	result = r;
6189	>	CountedCompleter<?> c;
6190	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6191	>	@SuppressWarnings("unchecked")
6192	>	MapReduceEntriesToIntTask<K,V>
6193	>	t = (MapReduceEntriesToIntTask<K,V>)c,
6194	>	s = t.rights;
6195	>	while (s != null) {
6196	>	t.result = reducer.applyAsInt(t.result, s.result);
6197	>	s = t.rights = s.nextRight;
6198	>	}
6199	>	}
6200	>	}
6201	>	}
6202	>	}
6203	>
6204	>	@SuppressWarnings("serial")
6205	>	static final class MapReduceMappingsToIntTask<K,V>
6206	>	extends BulkTask<K,V,Integer> {
6207	>	final ToIntBiFunction<? super K, ? super V> transformer;
6208	>	final IntBinaryOperator reducer;
6209	>	final int basis;
6210	>	int result;
6211	>	MapReduceMappingsToIntTask<K,V> rights, nextRight;
6212	>	MapReduceMappingsToIntTask
6213	>	(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
6214	>	MapReduceMappingsToIntTask<K,V> nextRight,
6215	>	ToIntBiFunction<? super K, ? super V> transformer,
6216	>	int basis,
6217	>	IntBinaryOperator reducer) {
6218	>	super(p, b, i, f, t); this.nextRight = nextRight;
6219	>	this.transformer = transformer;
6220	>	this.basis = basis; this.reducer = reducer;
6221	>	}
6222	>	public final Integer getRawResult() { return result; }
6223	>	public final void compute() {
6224	>	final ToIntBiFunction<? super K, ? super V> transformer;
6225	>	final IntBinaryOperator reducer;
6226	>	if ((transformer = this.transformer) != null &&
6227	>	(reducer = this.reducer) != null) {
6228	>	int r = this.basis;
6229	>	for (int i = baseIndex, f, h; batch > 0 &&
6230	>	(h = ((f = baseLimit) + i) >>> 1) > i;) {
6231	>	addToPendingCount(1);
6232	>	(rights = new MapReduceMappingsToIntTask<K,V>
6233	>	(this, batch >>>= 1, baseLimit = h, f, tab,
6234	>	rights, transformer, r, reducer)).fork();
6235	>	}
6236	>	for (Node<K,V> p; (p = advance()) != null; )
6237	>	r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
6238	>	result = r;
6239	>	CountedCompleter<?> c;
6240	>	for (c = firstComplete(); c != null; c = c.nextComplete()) {
6241	>	@SuppressWarnings("unchecked")
6242	>	MapReduceMappingsToIntTask<K,V>
6243	>	t = (MapReduceMappingsToIntTask<K,V>)c,
6244	>	s = t.rights;
6245	>	while (s != null) {
6246	>	t.result = reducer.applyAsInt(t.result, s.result);
6247	>	s = t.rights = s.nextRight;
6248	>	}
6249	>	}
6250	>	}
6251		}
6252		}
6253
6254		// Unsafe mechanics
6255	<	private static final sun.misc.Unsafe UNSAFE;
6256	<	private static final long SBASE;
6257	<	private static final int SSHIFT;
6258	<	private static final long TBASE;
6259	<	private static final int TSHIFT;
6255	>	private static final sun.misc.Unsafe U;
6256	>	private static final long SIZECTL;
6257	>	private static final long TRANSFERINDEX;
6258	>	private static final long BASECOUNT;
6259	>	private static final long CELLSBUSY;
6260	>	private static final long CELLVALUE;
6261	>	private static final long ABASE;
6262	>	private static final int ASHIFT;
6263
6264		static {
1466	–	int ss, ts;
6265		try {
6266	<	UNSAFE = sun.misc.Unsafe.getUnsafe();
6267	<	Class<?> tc = HashEntry[].class;
6268	<	Class<?> sc = Segment[].class;
6269	<	TBASE = UNSAFE.arrayBaseOffset(tc);
6270	<	SBASE = UNSAFE.arrayBaseOffset(sc);
6271	<	ts = UNSAFE.arrayIndexScale(tc);
6272	<	ss = UNSAFE.arrayIndexScale(sc);
6273	<	} catch (Exception e) {
6266	>	U = sun.misc.Unsafe.getUnsafe();
6267	>	Class<?> k = ConcurrentHashMap.class;
6268	>	SIZECTL = U.objectFieldOffset
6269	>	(k.getDeclaredField("sizeCtl"));
6270	>	TRANSFERINDEX = U.objectFieldOffset
6271	>	(k.getDeclaredField("transferIndex"));
6272	>	BASECOUNT = U.objectFieldOffset
6273	>	(k.getDeclaredField("baseCount"));
6274	>	CELLSBUSY = U.objectFieldOffset
6275	>	(k.getDeclaredField("cellsBusy"));
6276	>	Class<?> ck = CounterCell.class;
6277	>	CELLVALUE = U.objectFieldOffset
6278	>	(ck.getDeclaredField("value"));
6279	>	Class<?> ak = Node[].class;
6280	>	ABASE = U.arrayBaseOffset(ak);
6281	>	int scale = U.arrayIndexScale(ak);
6282	>	if ((scale & (scale - 1)) != 0)
6283	>	throw new Error("data type scale not a power of two");
6284	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6285	>	} catch (ReflectiveOperationException e) {
6286		throw new Error(e);
6287		}
1478	–	if ((ss & (ss-1)) != 0 || (ts & (ts-1)) != 0)
1479	–	throw new Error("data type scale not a power of two");
1480	–	SSHIFT = 31 - Integer.numberOfLeadingZeros(ss);
1481	–	TSHIFT = 31 - Integer.numberOfLeadingZeros(ts);
6288		}
1483	–
6289		}

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines