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Comparing jsr166/src/main/java/util/concurrent/ConcurrentHashMap.java (file contents):
Revision 1.228 by jsr166, Tue Jun 18 18:39:14 2013 UTC vs.
Revision 1.307 by jsr166, Sun Mar 11 18:00:05 2018 UTC

#	Line 10 | Line 10 | import java.io.ObjectStreamField;
10		import java.io.Serializable;
11		import java.lang.reflect.ParameterizedType;
12		import java.lang.reflect.Type;
13	+	import java.util.AbstractMap;
14		import java.util.Arrays;
15		import java.util.Collection;
15	–	import java.util.Comparator;
16	–	import java.util.ConcurrentModificationException;
16		import java.util.Enumeration;
17		import java.util.HashMap;
18		import java.util.Hashtable;
#	Line 22 | Line 21 | import java.util.Map;
21		import java.util.NoSuchElementException;
22		import java.util.Set;
23		import java.util.Spliterator;
25	–	import java.util.concurrent.ConcurrentMap;
26	–	import java.util.concurrent.ForkJoinPool;
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;
32	–	import java.util.function.BinaryOperator;
29		import java.util.function.Consumer;
30		import java.util.function.DoubleBinaryOperator;
31		import java.util.function.Function;
32		import java.util.function.IntBinaryOperator;
33		import java.util.function.LongBinaryOperator;
34	+	import java.util.function.Predicate;
35		import java.util.function.ToDoubleBiFunction;
36		import java.util.function.ToDoubleFunction;
37		import java.util.function.ToIntBiFunction;
#	Line 42 | Line 39 | import java.util.function.ToIntFunction;
39		import java.util.function.ToLongBiFunction;
40		import java.util.function.ToLongFunction;
41		import java.util.stream.Stream;
42	+	import jdk.internal.misc.Unsafe;
43
44		/**
45		* A hash table supporting full concurrency of retrievals and
#	Line 64 | Line 62 | import java.util.stream.Stream;
62		* that key reporting the updated value.)  For aggregate operations
63		* such as {@code putAll} and {@code clear}, concurrent retrievals may
64		* reflect insertion or removal of only some entries.  Similarly,
65	<	* Iterators and Enumerations return elements reflecting the state of
66	<	* the hash table at some point at or since the creation of the
65	>	* Iterators, Spliterators and Enumerations return elements reflecting the
66	>	* state of the hash table at some point at or since the creation of the
67		* iterator/enumeration.  They do <em>not</em> throw {@link
68	<	* ConcurrentModificationException}.  However, iterators are designed
69	<	* to be used by only one thread at a time.  Bear in mind that the
70	<	* results of aggregate status methods including {@code size}, {@code
71	<	* isEmpty}, and {@code containsValue} are typically useful only when
72	<	* a map is not undergoing concurrent updates in other threads.
68	>	* java.util.ConcurrentModificationException ConcurrentModificationException}.
69	>	* However, iterators are designed to be used by only one thread at a time.
70	>	* Bear in mind that the results of aggregate status methods including
71	>	* {@code size}, {@code isEmpty}, and {@code containsValue} are typically
72	>	* useful only when a map is not undergoing concurrent updates in other threads.
73		* Otherwise the results of these methods reflect transient states
74		* that may be adequate for monitoring or estimation purposes, but not
75		* for program control.
#	Line 104 | Line 102 | import java.util.stream.Stream;
102		* mapped values are (perhaps transiently) not used or all take the
103		* same mapping value.
104		*
105	<	* <p>A ConcurrentHashMap can be used as scalable frequency map (a
105	>	* <p>A ConcurrentHashMap can be used as a scalable frequency map (a
106		* form of histogram or multiset) by using {@link
107		* java.util.concurrent.atomic.LongAdder} values and initializing via
108		* {@link #computeIfAbsent computeIfAbsent}. For example, to add a count
109		* to a {@code ConcurrentHashMap<String,LongAdder> freqs}, you can use
110	<	* {@code freqs.computeIfAbsent(k -> new LongAdder()).increment();}
110	>	* {@code freqs.computeIfAbsent(key, k -> new LongAdder()).increment();}
111		*
112		* <p>This class and its views and iterators implement all of the
113		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
#	Line 124 | Line 122 | import java.util.stream.Stream;
122		* being concurrently updated by other threads; for example, when
123		* computing a snapshot summary of the values in a shared registry.
124		* There are three kinds of operation, each with four forms, accepting
125	<	* functions with Keys, Values, Entries, and (Key, Value) arguments
126	<	* and/or return values. Because the elements of a ConcurrentHashMap
127	<	* are not ordered in any particular way, and may be processed in
128	<	* different orders in different parallel executions, the correctness
129	<	* of supplied functions should not depend on any ordering, or on any
130	<	* other objects or values that may transiently change while
131	<	* computation is in progress; and except for forEach actions, should
132	<	* ideally be side-effect-free. Bulk operations on {@link Map.Entry}
133	<	* objects do not support method {@code setValue}.
125	>	* functions with keys, values, entries, and (key, value) pairs as
126	>	* arguments and/or return values. Because the elements of a
127	>	* ConcurrentHashMap are not ordered in any particular way, and may be
128	>	* processed in different orders in different parallel executions, the
129	>	* correctness of supplied functions should not depend on any
130	>	* ordering, or on any other objects or values that may transiently
131	>	* change while computation is in progress; and except for forEach
132	>	* actions, should ideally be side-effect-free. Bulk operations on
133	>	* {@link Map.Entry} objects do not support method {@code setValue}.
134		*
135		* <ul>
136	<	* <li> forEach: Perform a given action on each element.
136	>	* <li>forEach: Performs a given action on each element.
137		* A variant form applies a given transformation on each element
138	<	* before performing the action.</li>
138	>	* before performing the action.
139		*
140	<	* <li> search: Return the first available non-null result of
140	>	* <li>search: Returns the first available non-null result of
141		* applying a given function on each element; skipping further
142	<	* search when a result is found.</li>
142	>	* search when a result is found.
143		*
144	<	* <li> reduce: Accumulate each element.  The supplied reduction
144	>	* <li>reduce: Accumulates each element.  The supplied reduction
145		* function cannot rely on ordering (more formally, it should be
146		* both associative and commutative).  There are five variants:
147		*
148		* <ul>
149		*
150	<	* <li> Plain reductions. (There is not a form of this method for
150	>	* <li>Plain reductions. (There is not a form of this method for
151		* (key, value) function arguments since there is no corresponding
152	<	* return type.)</li>
152	>	* return type.)
153		*
154	<	* <li> Mapped reductions that accumulate the results of a given
155	<	* function applied to each element.</li>
154	>	* <li>Mapped reductions that accumulate the results of a given
155	>	* function applied to each element.
156		*
157	<	* <li> Reductions to scalar doubles, longs, and ints, using a
158	<	* given basis value.</li>
157	>	* <li>Reductions to scalar doubles, longs, and ints, using a
158	>	* given basis value.
159		*
160		* </ul>
163	–	* </li>
161		* </ul>
162		*
163		* <p>These bulk operations accept a {@code parallelismThreshold}
#	Line 227 | Line 224 | import java.util.stream.Stream;
224		* <p>All arguments to all task methods must be non-null.
225		*
226		* <p>This class is a member of the
227	<	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
227	>	* <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
228		* Java Collections Framework</a>.
229		*
230		* @since 1.5
#	Line 235 | Line 232 | import java.util.stream.Stream;
232		* @param <K> the type of keys maintained by this map
233		* @param <V> the type of mapped values
234		*/
235	<	public class ConcurrentHashMap<K,V> implements ConcurrentMap<K,V>, Serializable {
235	>	public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
236	>	implements ConcurrentMap<K,V>, Serializable {
237		private static final long serialVersionUID = 7249069246763182397L;
238
239		/*
#	Line 262 | Line 260 | public class ConcurrentHashMap<K,V> impl
260		* because they have negative hash fields and null key and value
261		* fields. (These special nodes are either uncommon or transient,
262		* so the impact of carrying around some unused fields is
263	<	* insignficant.)
263	>	* insignificant.)
264		*
265		* The table is lazily initialized to a power-of-two size upon the
266		* first insertion.  Each bin in the table normally contains a
#	Line 270 | Line 268 | public class ConcurrentHashMap<K,V> impl
268		* Table accesses require volatile/atomic reads, writes, and
269		* CASes.  Because there is no other way to arrange this without
270		* adding further indirections, we use intrinsics
271	<	* (sun.misc.Unsafe) operations.
271	>	* (jdk.internal.misc.Unsafe) operations.
272		*
273		* We use the top (sign) bit of Node hash fields for control
274		* purposes -- it is available anyway because of addressing
#	Line 343 | Line 341 | public class ConcurrentHashMap<K,V> impl
341		* The table is resized when occupancy exceeds a percentage
342		* threshold (nominally, 0.75, but see below).  Any thread
343		* noticing an overfull bin may assist in resizing after the
344	<	* initiating thread allocates and sets up the replacement
345	<	* array. However, rather than stalling, these other threads may
346	<	* proceed with insertions etc.  The use of TreeBins shields us
347	<	* from the worst case effects of overfilling while resizes are in
344	>	* initiating thread allocates and sets up the replacement array.
345	>	* However, rather than stalling, these other threads may proceed
346	>	* with insertions etc.  The use of TreeBins shields us from the
347	>	* worst case effects of overfilling while resizes are in
348		* progress.  Resizing proceeds by transferring bins, one by one,
349	<	* from the table to the next table. To enable concurrency, the
350	<	* next table must be (incrementally) prefilled with place-holders
351	<	* serving as reverse forwarders to the old table.  Because we are
349	>	* from the table to the next table. However, threads claim small
350	>	* blocks of indices to transfer (via field transferIndex) before
351	>	* doing so, reducing contention.  A generation stamp in field
352	>	* sizeCtl ensures that resizings do not overlap. Because we are
353		* using power-of-two expansion, the elements from each bin must
354		* either stay at same index, or move with a power of two
355		* offset. We eliminate unnecessary node creation by catching
#	Line 371 | Line 370 | public class ConcurrentHashMap<K,V> impl
370		* locks, average aggregate waits become shorter as resizing
371		* progresses.  The transfer operation must also ensure that all
372		* accessible bins in both the old and new table are usable by any
373	<	* traversal.  This is arranged by proceeding from the last bin
374	<	* (table.length - 1) up towards the first.  Upon seeing a
375	<	* forwarding node, traversals (see class Traverser) arrange to
376	<	* move to the new table without revisiting nodes.  However, to
377	<	* ensure that no intervening nodes are skipped, bin splitting can
378	<	* only begin after the associated reverse-forwarders are in
379	<	* place.
373	>	* traversal.  This is arranged in part by proceeding from the
374	>	* last bin (table.length - 1) up towards the first.  Upon seeing
375	>	* a forwarding node, traversals (see class Traverser) arrange to
376	>	* move to the new table without revisiting nodes.  To ensure that
377	>	* no intervening nodes are skipped even when moved out of order,
378	>	* a stack (see class TableStack) is created on first encounter of
379	>	* a forwarding node during a traversal, to maintain its place if
380	>	* later processing the current table. The need for these
381	>	* save/restore mechanics is relatively rare, but when one
382	>	* forwarding node is encountered, typically many more will be.
383	>	* So Traversers use a simple caching scheme to avoid creating so
384	>	* many new TableStack nodes. (Thanks to Peter Levart for
385	>	* suggesting use of a stack here.)
386		*
387		* The traversal scheme also applies to partial traversals of
388		* ranges of bins (via an alternate Traverser constructor)
#	Line 409 | Line 414 | public class ConcurrentHashMap<K,V> impl
414		* related operations (which is the main reason we cannot use
415		* existing collections such as TreeMaps). TreeBins contain
416		* Comparable elements, but may contain others, as well as
417	<	* elements that are Comparable but not necessarily Comparable
418	<	* for the same T, so we cannot invoke compareTo among them. To
419	<	* handle this, the tree is ordered primarily by hash value, then
420	<	* by Comparable.compareTo order if applicable.  On lookup at a
421	<	* node, if elements are not comparable or compare as 0 then both
422	<	* left and right children may need to be searched in the case of
423	<	* tied hash values. (This corresponds to the full list search
424	<	* that would be necessary if all elements were non-Comparable and
425	<	* had tied hashes.)  The red-black balancing code is updated from
426	<	* pre-jdk-collections
417	>	* elements that are Comparable but not necessarily Comparable for
418	>	* the same T, so we cannot invoke compareTo among them. To handle
419	>	* this, the tree is ordered primarily by hash value, then by
420	>	* Comparable.compareTo order if applicable.  On lookup at a node,
421	>	* if elements are not comparable or compare as 0 then both left
422	>	* and right children may need to be searched in the case of tied
423	>	* hash values. (This corresponds to the full list search that
424	>	* would be necessary if all elements were non-Comparable and had
425	>	* tied hashes.) On insertion, to keep a total ordering (or as
426	>	* close as is required here) across rebalancings, we compare
427	>	* classes and identityHashCodes as tie-breakers. The red-black
428	>	* balancing code is updated from pre-jdk-collections
429		* (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
430		* based in turn on Cormen, Leiserson, and Rivest "Introduction to
431		* Algorithms" (CLR).
432		*
433		* TreeBins also require an additional locking mechanism.  While
434		* list traversal is always possible by readers even during
435	<	* updates, tree traversal is not, mainly beause of tree-rotations
435	>	* updates, tree traversal is not, mainly because of tree-rotations
436		* that may change the root node and/or its linkages.  TreeBins
437		* include a simple read-write lock mechanism parasitic on the
438		* main bin-synchronization strategy: Structural adjustments
#	Line 441 | Line 448 | public class ConcurrentHashMap<K,V> impl
448		*
449		* Maintaining API and serialization compatibility with previous
450		* versions of this class introduces several oddities. Mainly: We
451	<	* leave untouched but unused constructor arguments refering to
451	>	* leave untouched but unused constructor arguments referring to
452		* concurrencyLevel. We accept a loadFactor constructor argument,
453		* but apply it only to initial table capacity (which is the only
454		* time that we can guarantee to honor it.) We also declare an
455		* unused "Segment" class that is instantiated in minimal form
456		* only when serializing.
457		*
458	+	* Also, solely for compatibility with previous versions of this
459	+	* class, it extends AbstractMap, even though all of its methods
460	+	* are overridden, so it is just useless baggage.
461	+	*
462		* This file is organized to make things a little easier to follow
463		* while reading than they might otherwise: First the main static
464		* declarations and utilities, then fields, then main public
#	Line 528 | Line 539 | public class ConcurrentHashMap<K,V> impl
539		*/
540		private static final int MIN_TRANSFER_STRIDE = 16;
541
542	+	/**
543	+	* The number of bits used for generation stamp in sizeCtl.
544	+	* Must be at least 6 for 32bit arrays.
545	+	*/
546	+	private static final int RESIZE_STAMP_BITS = 16;
547	+
548	+	/**
549	+	* The maximum number of threads that can help resize.
550	+	* Must fit in 32 - RESIZE_STAMP_BITS bits.
551	+	*/
552	+	private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
553	+
554	+	/**
555	+	* The bit shift for recording size stamp in sizeCtl.
556	+	*/
557	+	private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
558	+
559		/*
560		* Encodings for Node hash fields. See above for explanation.
561		*/
562	<	static final int MOVED     = 0x8fffffff; // (-1) hash for forwarding nodes
563	<	static final int TREEBIN   = 0x80000000; // hash for heads of treea
564	<	static final int RESERVED  = 0x80000001; // hash for transient reservations
562	>	static final int MOVED     = -1; // hash for forwarding nodes
563	>	static final int TREEBIN   = -2; // hash for roots of trees
564	>	static final int RESERVED  = -3; // hash for transient reservations
565		static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash
566
567		/** Number of CPUS, to place bounds on some sizings */
568		static final int NCPU = Runtime.getRuntime().availableProcessors();
569
570	<	/** For serialization compatibility. */
570	>	/**
571	>	* Serialized pseudo-fields, provided only for jdk7 compatibility.
572	>	* @serialField segments Segment[]
573	>	*   The segments, each of which is a specialized hash table.
574	>	* @serialField segmentMask int
575	>	*   Mask value for indexing into segments. The upper bits of a
576	>	*   key's hash code are used to choose the segment.
577	>	* @serialField segmentShift int
578	>	*   Shift value for indexing within segments.
579	>	*/
580		private static final ObjectStreamField[] serialPersistentFields = {
581		new ObjectStreamField("segments", Segment[].class),
582		new ObjectStreamField("segmentMask", Integer.TYPE),
583	<	new ObjectStreamField("segmentShift", Integer.TYPE)
583	>	new ObjectStreamField("segmentShift", Integer.TYPE),
584		};
585
586		/* ---------------- Nodes -------------- */
#	Line 552 | Line 589 | public class ConcurrentHashMap<K,V> impl
589		* Key-value entry.  This class is never exported out as a
590		* user-mutable Map.Entry (i.e., one supporting setValue; see
591		* MapEntry below), but can be used for read-only traversals used
592	<	* in bulk tasks.  Subclasses of Node with a negativehash field
592	>	* in bulk tasks.  Subclasses of Node with a negative hash field
593		* are special, and contain null keys and values (but are never
594		* exported).  Otherwise, keys and vals are never null.
595		*/
#	Line 560 | Line 597 | public class ConcurrentHashMap<K,V> impl
597		final int hash;
598		final K key;
599		volatile V val;
600	<	Node<K,V> next;
600	>	volatile Node<K,V> next;
601
602	<	Node(int hash, K key, V val, Node<K,V> next) {
602	>	Node(int hash, K key, V val) {
603		this.hash = hash;
604		this.key = key;
605		this.val = val;
606	+	}
607	+
608	+	Node(int hash, K key, V val, Node<K,V> next) {
609	+	this(hash, key, val);
610		this.next = next;
611		}
612
613	<	public final K getKey()       { return key; }
614	<	public final V getValue()     { return val; }
615	<	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
616	<	public final String toString(){ return key + "=" + val; }
613	>	public final K getKey()     { return key; }
614	>	public final V getValue()   { return val; }
615	>	public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
616	>	public final String toString() {
617	>	return Helpers.mapEntryToString(key, val);
618	>	}
619		public final V setValue(V value) {
620		throw new UnsupportedOperationException();
621		}
#	Line 645 | Line 688 | public class ConcurrentHashMap<K,V> impl
688		*/
689		static Class<?> comparableClassFor(Object x) {
690		if (x instanceof Comparable) {
691	<	Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
691	>	Class<?> c; Type[] ts, as; ParameterizedType p;
692		if ((c = x.getClass()) == String.class) // bypass checks
693		return c;
694		if ((ts = c.getGenericInterfaces()) != null) {
695	<	for (int i = 0; i < ts.length; ++i) {
696	<	if (((t = ts[i]) instanceof ParameterizedType) &&
695	>	for (Type t : ts) {
696	>	if ((t instanceof ParameterizedType) &&
697		((p = (ParameterizedType)t).getRawType() ==
698		Comparable.class) &&
699		(as = p.getActualTypeArguments()) != null &&
#	Line 675 | Line 718 | public class ConcurrentHashMap<K,V> impl
718		/* ---------------- Table element access -------------- */
719
720		/*
721	<	* Volatile access methods are used for table elements as well as
721	>	* Atomic access methods are used for table elements as well as
722		* elements of in-progress next table while resizing.  All uses of
723		* the tab arguments must be null checked by callers.  All callers
724		* also paranoically precheck that tab's length is not zero (or an
#	Line 685 | Line 728 | public class ConcurrentHashMap<K,V> impl
728		* errors by users, these checks must operate on local variables,
729		* which accounts for some odd-looking inline assignments below.
730		* Note that calls to setTabAt always occur within locked regions,
731	<	* and so do not need full volatile semantics, but still require
689	<	* ordering to maintain concurrent readability.
731	>	* and so require only release ordering.
732		*/
733
734		@SuppressWarnings("unchecked")
735		static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
736	<	return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
736	>	return (Node<K,V>)U.getObjectAcquire(tab, ((long)i << ASHIFT) + ABASE);
737		}
738
739		static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
740		Node<K,V> c, Node<K,V> v) {
741	<	return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
741	>	return U.compareAndSetObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
742		}
743
744		static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
745	<	U.putOrderedObject(tab, ((long)i << ASHIFT) + ABASE, v);
745	>	U.putObjectRelease(tab, ((long)i << ASHIFT) + ABASE, v);
746		}
747
748		/* ---------------- Fields -------------- */
#	Line 739 | Line 781 | public class ConcurrentHashMap<K,V> impl
781		private transient volatile int transferIndex;
782
783		/**
742	–	* The least available table index to split while resizing.
743	–	*/
744	–	private transient volatile int transferOrigin;
745	–
746	–	/**
784		* Spinlock (locked via CAS) used when resizing and/or creating CounterCells.
785		*/
786		private transient volatile int cellsBusy;
#	Line 956 | Line 993 | public class ConcurrentHashMap<K,V> impl
993		int hash = spread(key.hashCode());
994		int binCount = 0;
995		for (Node<K,V>[] tab = table;;) {
996	<	Node<K,V> f; int n, i, fh;
996	>	Node<K,V> f; int n, i, fh; K fk; V fv;
997		if (tab == null || (n = tab.length) == 0)
998		tab = initTable();
999		else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
1000	<	if (casTabAt(tab, i, null,
964	<	new Node<K,V>(hash, key, value, null)))
1000	>	if (casTabAt(tab, i, null, new Node<K,V>(hash, key, value)))
1001		break;                   // no lock when adding to empty bin
1002		}
1003		else if ((fh = f.hash) == MOVED)
1004		tab = helpTransfer(tab, f);
1005	+	else if (onlyIfAbsent // check first node without acquiring lock
1006	+	&& fh == hash
1007	+	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1008	+	&& (fv = f.val) != null)
1009	+	return fv;
1010		else {
1011		V oldVal = null;
1012		synchronized (f) {
#	Line 984 | Line 1025 | public class ConcurrentHashMap<K,V> impl
1025		}
1026		Node<K,V> pred = e;
1027		if ((e = e.next) == null) {
1028	<	pred.next = new Node<K,V>(hash, key,
988	<	value, null);
1028	>	pred.next = new Node<K,V>(hash, key, value);
1029		break;
1030		}
1031		}
#	Line 1000 | Line 1040 | public class ConcurrentHashMap<K,V> impl
1040		p.val = value;
1041		}
1042		}
1043	+	else if (f instanceof ReservationNode)
1044	+	throw new IllegalStateException("Recursive update");
1045		}
1046		}
1047		if (binCount != 0) {
#	Line 1102 | Line 1144 | public class ConcurrentHashMap<K,V> impl
1144		}
1145		}
1146		}
1147	+	else if (f instanceof ReservationNode)
1148	+	throw new IllegalStateException("Recursive update");
1149		}
1150		}
1151		if (validated) {
#	Line 1162 | Line 1206 | public class ConcurrentHashMap<K,V> impl
1206		* operations.  It does not support the {@code add} or
1207		* {@code addAll} operations.
1208		*
1209	<	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1210	<	* that will never throw {@link ConcurrentModificationException},
1211	<	* and guarantees to traverse elements as they existed upon
1212	<	* construction of the iterator, and may (but is not guaranteed to)
1213	<	* reflect any modifications subsequent to construction.
1209	>	* <p>The view's iterators and spliterators are
1210	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1211	>	*
1212	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1213	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1214		*
1215		* @return the set view
1216		*/
1217		public KeySetView<K,V> keySet() {
1218		KeySetView<K,V> ks;
1219	<	return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
1219	>	if ((ks = keySet) != null) return ks;
1220	>	return keySet = new KeySetView<K,V>(this, null);
1221		}
1222
1223		/**
#	Line 1185 | Line 1230 | public class ConcurrentHashMap<K,V> impl
1230		* {@code retainAll}, and {@code clear} operations.  It does not
1231		* support the {@code add} or {@code addAll} operations.
1232		*
1233	<	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1234	<	* that will never throw {@link ConcurrentModificationException},
1235	<	* and guarantees to traverse elements as they existed upon
1236	<	* construction of the iterator, and may (but is not guaranteed to)
1237	<	* reflect any modifications subsequent to construction.
1233	>	* <p>The view's iterators and spliterators are
1234	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1235	>	*
1236	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
1237	>	* and {@link Spliterator#NONNULL}.
1238		*
1239		* @return the collection view
1240		*/
1241		public Collection<V> values() {
1242		ValuesView<K,V> vs;
1243	<	return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
1243	>	if ((vs = values) != null) return vs;
1244	>	return values = new ValuesView<K,V>(this);
1245		}
1246
1247		/**
#	Line 1207 | Line 1253 | public class ConcurrentHashMap<K,V> impl
1253		* {@code removeAll}, {@code retainAll}, and {@code clear}
1254		* operations.
1255		*
1256	<	* <p>The view's {@code iterator} is a "weakly consistent" iterator
1257	<	* that will never throw {@link ConcurrentModificationException},
1258	<	* and guarantees to traverse elements as they existed upon
1259	<	* construction of the iterator, and may (but is not guaranteed to)
1260	<	* reflect any modifications subsequent to construction.
1256	>	* <p>The view's iterators and spliterators are
1257	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
1258	>	*
1259	>	* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
1260	>	* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
1261		*
1262		* @return the set view
1263		*/
1264		public Set<Map.Entry<K,V>> entrySet() {
1265		EntrySetView<K,V> es;
1266	<	return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
1266	>	if ((es = entrySet) != null) return es;
1267	>	return entrySet = new EntrySetView<K,V>(this);
1268		}
1269
1270		/**
#	Line 1309 | Line 1356 | public class ConcurrentHashMap<K,V> impl
1356
1357		/**
1358		* Stripped-down version of helper class used in previous version,
1359	<	* declared for the sake of serialization compatibility
1359	>	* declared for the sake of serialization compatibility.
1360		*/
1361		static class Segment<K,V> extends ReentrantLock implements Serializable {
1362		private static final long serialVersionUID = 2249069246763182397L;
#	Line 1318 | Line 1365 | public class ConcurrentHashMap<K,V> impl
1365		}
1366
1367		/**
1368	<	* Saves the state of the {@code ConcurrentHashMap} instance to a
1369	<	* stream (i.e., serializes it).
1368	>	* Saves this map to a stream (that is, serializes it).
1369	>	*
1370		* @param s the stream
1371	+	* @throws java.io.IOException if an I/O error occurs
1372		* @serialData
1373	<	* the key (Object) and value (Object)
1374	<	* for each key-value mapping, followed by a null pair.
1373	>	* the serialized fields, followed by the key (Object) and value
1374	>	* (Object) for each key-value mapping, followed by a null pair.
1375		* The key-value mappings are emitted in no particular order.
1376		*/
1377		private void writeObject(java.io.ObjectOutputStream s)
#	Line 1338 | Line 1386 | public class ConcurrentHashMap<K,V> impl
1386		}
1387		int segmentShift = 32 - sshift;
1388		int segmentMask = ssize - 1;
1389	<	@SuppressWarnings("unchecked") Segment<K,V>[] segments = (Segment<K,V>[])
1389	>	@SuppressWarnings("unchecked")
1390	>	Segment<K,V>[] segments = (Segment<K,V>[])
1391		new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
1392		for (int i = 0; i < segments.length; ++i)
1393		segments[i] = new Segment<K,V>(LOAD_FACTOR);
1394	<	s.putFields().put("segments", segments);
1395	<	s.putFields().put("segmentShift", segmentShift);
1396	<	s.putFields().put("segmentMask", segmentMask);
1394	>	java.io.ObjectOutputStream.PutField streamFields = s.putFields();
1395	>	streamFields.put("segments", segments);
1396	>	streamFields.put("segmentShift", segmentShift);
1397	>	streamFields.put("segmentMask", segmentMask);
1398		s.writeFields();
1399
1400		Node<K,V>[] t;
#	Line 1357 | Line 1407 | public class ConcurrentHashMap<K,V> impl
1407		}
1408		s.writeObject(null);
1409		s.writeObject(null);
1360	–	segments = null; // throw away
1410		}
1411
1412		/**
1413	<	* Reconstitutes the instance from a stream (that is, deserializes it).
1413	>	* Reconstitutes this map from a stream (that is, deserializes it).
1414		* @param s the stream
1415	+	* @throws ClassNotFoundException if the class of a serialized object
1416	+	*         could not be found
1417	+	* @throws java.io.IOException if an I/O error occurs
1418		*/
1419		private void readObject(java.io.ObjectInputStream s)
1420		throws java.io.IOException, ClassNotFoundException {
#	Line 1378 | Line 1430 | public class ConcurrentHashMap<K,V> impl
1430		long size = 0L;
1431		Node<K,V> p = null;
1432		for (;;) {
1433	<	@SuppressWarnings("unchecked") K k = (K) s.readObject();
1434	<	@SuppressWarnings("unchecked") V v = (V) s.readObject();
1433	>	@SuppressWarnings("unchecked")
1434	>	K k = (K) s.readObject();
1435	>	@SuppressWarnings("unchecked")
1436	>	V v = (V) s.readObject();
1437		if (k != null && v != null) {
1438		p = new Node<K,V>(spread(k.hashCode()), k, v, p);
1439		++size;
#	Line 1397 | Line 1451 | public class ConcurrentHashMap<K,V> impl
1451		int sz = (int)size;
1452		n = tableSizeFor(sz + (sz >>> 1) + 1);
1453		}
1454	<	@SuppressWarnings({"rawtypes","unchecked"})
1455	<	Node<K,V>[] tab = (Node<K,V>[])new Node[n];
1454	>	@SuppressWarnings("unchecked")
1455	>	Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
1456		int mask = n - 1;
1457		long added = 0L;
1458		while (p != null) {
#	Line 1556 | Line 1610 | public class ConcurrentHashMap<K,V> impl
1610		}
1611
1612		/**
1613	+	* Helper method for EntrySetView.removeIf.
1614	+	*/
1615	+	boolean removeEntryIf(Predicate<? super Entry<K,V>> function) {
1616	+	if (function == null) throw new NullPointerException();
1617	+	Node<K,V>[] t;
1618	+	boolean removed = false;
1619	+	if ((t = table) != null) {
1620	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1621	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
1622	+	K k = p.key;
1623	+	V v = p.val;
1624	+	Map.Entry<K,V> e = new AbstractMap.SimpleImmutableEntry<>(k, v);
1625	+	if (function.test(e) && replaceNode(k, null, v) != null)
1626	+	removed = true;
1627	+	}
1628	+	}
1629	+	return removed;
1630	+	}
1631	+
1632	+	/**
1633	+	* Helper method for ValuesView.removeIf.
1634	+	*/
1635	+	boolean removeValueIf(Predicate<? super V> function) {
1636	+	if (function == null) throw new NullPointerException();
1637	+	Node<K,V>[] t;
1638	+	boolean removed = false;
1639	+	if ((t = table) != null) {
1640	+	Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
1641	+	for (Node<K,V> p; (p = it.advance()) != null; ) {
1642	+	K k = p.key;
1643	+	V v = p.val;
1644	+	if (function.test(v) && replaceNode(k, null, v) != null)
1645	+	removed = true;
1646	+	}
1647	+	}
1648	+	return removed;
1649	+	}
1650	+
1651	+	/**
1652		* If the specified key is not already associated with a value,
1653		* attempts to compute its value using the given mapping function
1654		* and enters it into this map unless {@code null}.  The entire
#	Line 1584 | Line 1677 | public class ConcurrentHashMap<K,V> impl
1677		V val = null;
1678		int binCount = 0;
1679		for (Node<K,V>[] tab = table;;) {
1680	<	Node<K,V> f; int n, i, fh;
1680	>	Node<K,V> f; int n, i, fh; K fk; V fv;
1681		if (tab == null || (n = tab.length) == 0)
1682		tab = initTable();
1683		else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
#	Line 1595 | Line 1688 | public class ConcurrentHashMap<K,V> impl
1688		Node<K,V> node = null;
1689		try {
1690		if ((val = mappingFunction.apply(key)) != null)
1691	<	node = new Node<K,V>(h, key, val, null);
1691	>	node = new Node<K,V>(h, key, val);
1692		} finally {
1693		setTabAt(tab, i, node);
1694		}
#	Line 1606 | Line 1699 | public class ConcurrentHashMap<K,V> impl
1699		}
1700		else if ((fh = f.hash) == MOVED)
1701		tab = helpTransfer(tab, f);
1702	+	else if (fh == h    // check first node without acquiring lock
1703	+	&& ((fk = f.key) == key || (fk != null && key.equals(fk)))
1704	+	&& (fv = f.val) != null)
1705	+	return fv;
1706		else {
1707		boolean added = false;
1708		synchronized (f) {
#	Line 1613 | Line 1710 | public class ConcurrentHashMap<K,V> impl
1710		if (fh >= 0) {
1711		binCount = 1;
1712		for (Node<K,V> e = f;; ++binCount) {
1713	<	K ek; V ev;
1713	>	K ek;
1714		if (e.hash == h &&
1715		((ek = e.key) == key ||
1716		(ek != null && key.equals(ek)))) {
#	Line 1623 | Line 1720 | public class ConcurrentHashMap<K,V> impl
1720		Node<K,V> pred = e;
1721		if ((e = e.next) == null) {
1722		if ((val = mappingFunction.apply(key)) != null) {
1723	+	if (pred.next != null)
1724	+	throw new IllegalStateException("Recursive update");
1725		added = true;
1726	<	pred.next = new Node<K,V>(h, key, val, null);
1726	>	pred.next = new Node<K,V>(h, key, val);
1727		}
1728		break;
1729		}
#	Line 1642 | Line 1741 | public class ConcurrentHashMap<K,V> impl
1741		t.putTreeVal(h, key, val);
1742		}
1743		}
1744	+	else if (f instanceof ReservationNode)
1745	+	throw new IllegalStateException("Recursive update");
1746		}
1747		}
1748		if (binCount != 0) {
#	Line 1737 | Line 1838 | public class ConcurrentHashMap<K,V> impl
1838		}
1839		}
1840		}
1841	+	else if (f instanceof ReservationNode)
1842	+	throw new IllegalStateException("Recursive update");
1843		}
1844		}
1845		if (binCount != 0)
#	Line 1789 | Line 1892 | public class ConcurrentHashMap<K,V> impl
1892		try {
1893		if ((val = remappingFunction.apply(key, null)) != null) {
1894		delta = 1;
1895	<	node = new Node<K,V>(h, key, val, null);
1895	>	node = new Node<K,V>(h, key, val);
1896		}
1897		} finally {
1898		setTabAt(tab, i, node);
#	Line 1828 | Line 1931 | public class ConcurrentHashMap<K,V> impl
1931		if ((e = e.next) == null) {
1932		val = remappingFunction.apply(key, null);
1933		if (val != null) {
1934	+	if (pred.next != null)
1935	+	throw new IllegalStateException("Recursive update");
1936		delta = 1;
1937	<	pred.next =
1833	<	new Node<K,V>(h, key, val, null);
1937	>	pred.next = new Node<K,V>(h, key, val);
1938		}
1939		break;
1940		}
#	Line 1860 | Line 1964 | public class ConcurrentHashMap<K,V> impl
1964		setTabAt(tab, i, untreeify(t.first));
1965		}
1966		}
1967	+	else if (f instanceof ReservationNode)
1968	+	throw new IllegalStateException("Recursive update");
1969		}
1970		}
1971		if (binCount != 0) {
#	Line 1906 | Line 2012 | public class ConcurrentHashMap<K,V> impl
2012		if (tab == null || (n = tab.length) == 0)
2013		tab = initTable();
2014		else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
2015	<	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
2015	>	if (casTabAt(tab, i, null, new Node<K,V>(h, key, value))) {
2016		delta = 1;
2017		val = value;
2018		break;
#	Line 1941 | Line 2047 | public class ConcurrentHashMap<K,V> impl
2047		if ((e = e.next) == null) {
2048		delta = 1;
2049		val = value;
2050	<	pred.next =
1945	<	new Node<K,V>(h, key, val, null);
2050	>	pred.next = new Node<K,V>(h, key, val);
2051		break;
2052		}
2053		}
#	Line 1969 | Line 2074 | public class ConcurrentHashMap<K,V> impl
2074		setTabAt(tab, i, untreeify(t.first));
2075		}
2076		}
2077	+	else if (f instanceof ReservationNode)
2078	+	throw new IllegalStateException("Recursive update");
2079		}
2080		}
2081		if (binCount != 0) {
#	Line 1986 | Line 2093 | public class ConcurrentHashMap<K,V> impl
2093		// Hashtable legacy methods
2094
2095		/**
2096	<	* Legacy method testing if some key maps into the specified value
2097	<	* in this table.  This method is identical in functionality to
2096	>	* Tests if some key maps into the specified value in this table.
2097	>	*
2098	>	* <p>Note that this method is identical in functionality to
2099		* {@link #containsValue(Object)}, and exists solely to ensure
2100		* full compatibility with class {@link java.util.Hashtable},
2101		* which supported this method prior to introduction of the
2102	<	* Java Collections framework.
2102	>	* Java Collections Framework.
2103		*
2104		* @param  value a value to search for
2105		* @return {@code true} if and only if some key maps to the
#	Line 2000 | Line 2108 | public class ConcurrentHashMap<K,V> impl
2108		*         {@code false} otherwise
2109		* @throws NullPointerException if the specified value is null
2110		*/
2111	<	@Deprecated public boolean contains(Object value) {
2111	>	public boolean contains(Object value) {
2112		return containsValue(value);
2113		}
2114
#	Line 2049 | Line 2157 | public class ConcurrentHashMap<K,V> impl
2157		* Creates a new {@link Set} backed by a ConcurrentHashMap
2158		* from the given type to {@code Boolean.TRUE}.
2159		*
2160	+	* @param <K> the element type of the returned set
2161		* @return the new set
2162		* @since 1.8
2163		*/
#	Line 2063 | Line 2172 | public class ConcurrentHashMap<K,V> impl
2172		*
2173		* @param initialCapacity The implementation performs internal
2174		* sizing to accommodate this many elements.
2175	+	* @param <K> the element type of the returned set
2176	+	* @return the new set
2177		* @throws IllegalArgumentException if the initial capacity of
2178		* elements is negative
2068	–	* @return the new set
2179		* @since 1.8
2180		*/
2181		public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
#	Line 2098 | Line 2208 | public class ConcurrentHashMap<K,V> impl
2208		static final class ForwardingNode<K,V> extends Node<K,V> {
2209		final Node<K,V>[] nextTable;
2210		ForwardingNode(Node<K,V>[] tab) {
2211	<	super(MOVED, null, null, null);
2211	>	super(MOVED, null, null);
2212		this.nextTable = tab;
2213		}
2214
2215		Node<K,V> find(int h, Object k) {
2216	<	Node<K,V> e; int n;
2217	<	Node<K,V>[] tab = nextTable;
2218	<	if (k != null && tab != null && (n = tab.length) > 0 &&
2219	<	(e = tabAt(tab, (n - 1) & h)) != null) {
2220	<	do {
2216	>	// loop to avoid arbitrarily deep recursion on forwarding nodes
2217	>	outer: for (Node<K,V>[] tab = nextTable;;) {
2218	>	Node<K,V> e; int n;
2219	>	if (k == null || tab == null || (n = tab.length) == 0 ||
2220	>	(e = tabAt(tab, (n - 1) & h)) == null)
2221	>	return null;
2222	>	for (;;) {
2223		int eh; K ek;
2224		if ((eh = e.hash) == h &&
2225		((ek = e.key) == k || (ek != null && k.equals(ek))))
2226		return e;
2227	<	if (eh < 0)
2228	<	return e.find(h, k);
2229	<	} while ((e = e.next) != null);
2227	>	if (eh < 0) {
2228	>	if (e instanceof ForwardingNode) {
2229	>	tab = ((ForwardingNode<K,V>)e).nextTable;
2230	>	continue outer;
2231	>	}
2232	>	else
2233	>	return e.find(h, k);
2234	>	}
2235	>	if ((e = e.next) == null)
2236	>	return null;
2237	>	}
2238		}
2119	–	return null;
2239		}
2240		}
2241
2242		/**
2243	<	* A place-holder node used in computeIfAbsent and compute
2243	>	* A place-holder node used in computeIfAbsent and compute.
2244		*/
2245		static final class ReservationNode<K,V> extends Node<K,V> {
2246		ReservationNode() {
2247	<	super(RESERVED, null, null, null);
2247	>	super(RESERVED, null, null);
2248		}
2249
2250		Node<K,V> find(int h, Object k) {
#	Line 2136 | Line 2255 | public class ConcurrentHashMap<K,V> impl
2255		/* ---------------- Table Initialization and Resizing -------------- */
2256
2257		/**
2258	+	* Returns the stamp bits for resizing a table of size n.
2259	+	* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
2260	+	*/
2261	+	static final int resizeStamp(int n) {
2262	+	return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
2263	+	}
2264	+
2265	+	/**
2266		* Initializes table, using the size recorded in sizeCtl.
2267		*/
2268		private final Node<K,V>[] initTable() {
#	Line 2143 | Line 2270 | public class ConcurrentHashMap<K,V> impl
2270		while ((tab = table) == null || tab.length == 0) {
2271		if ((sc = sizeCtl) < 0)
2272		Thread.yield(); // lost initialization race; just spin
2273	<	else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2273	>	else if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2274		try {
2275		if ((tab = table) == null || tab.length == 0) {
2276		int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
2277	<	@SuppressWarnings({"rawtypes","unchecked"})
2278	<	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2277	>	@SuppressWarnings("unchecked")
2278	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2279		table = tab = nt;
2280		sc = n - (n >>> 2);
2281		}
#	Line 2172 | Line 2299 | public class ConcurrentHashMap<K,V> impl
2299		* @param check if <0, don't check resize, if <= 1 only check if uncontended
2300		*/
2301		private final void addCount(long x, int check) {
2302	<	CounterCell[] as; long b, s;
2303	<	if ((as = counterCells) != null ||
2304	<	!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2305	<	CounterCell a; long v; int m;
2302	>	CounterCell[] cs; long b, s;
2303	>	if ((cs = counterCells) != null ||
2304	>	!U.compareAndSetLong(this, BASECOUNT, b = baseCount, s = b + x)) {
2305	>	CounterCell c; long v; int m;
2306		boolean uncontended = true;
2307	<	if (as == null || (m = as.length - 1) < 0 ||
2308	<	(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
2307	>	if (cs == null || (m = cs.length - 1) < 0 ||
2308	>	(c = cs[ThreadLocalRandom.getProbe() & m]) == null ||
2309		!(uncontended =
2310	<	U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
2310	>	U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))) {
2311		fullAddCount(x, uncontended);
2312		return;
2313		}
#	Line 2189 | Line 2316 | public class ConcurrentHashMap<K,V> impl
2316		s = sumCount();
2317		}
2318		if (check >= 0) {
2319	<	Node<K,V>[] tab, nt; int sc;
2319	>	Node<K,V>[] tab, nt; int n, sc;
2320		while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
2321	<	tab.length < MAXIMUM_CAPACITY) {
2321	>	(n = tab.length) < MAXIMUM_CAPACITY) {
2322	>	int rs = resizeStamp(n);
2323		if (sc < 0) {
2324	<	if (sc == -1 || transferIndex <= transferOrigin ||
2325	<	(nt = nextTable) == null)
2324	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2325	>	sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
2326	>	transferIndex <= 0)
2327		break;
2328	<	if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2328	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
2329		transfer(tab, nt);
2330		}
2331	<	else if (U.compareAndSwapInt(this, SIZECTL, sc, -2))
2331	>	else if (U.compareAndSetInt(this, SIZECTL, sc,
2332	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2333		transfer(tab, null);
2334		s = sumCount();
2335		}
#	Line 2211 | Line 2341 | public class ConcurrentHashMap<K,V> impl
2341		*/
2342		final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
2343		Node<K,V>[] nextTab; int sc;
2344	<	if ((f instanceof ForwardingNode) &&
2344	>	if (tab != null && (f instanceof ForwardingNode) &&
2345		(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
2346	<	if (nextTab == nextTable && tab == table &&
2347	<	transferIndex > transferOrigin && (sc = sizeCtl) < -1 &&
2348	<	U.compareAndSwapInt(this, SIZECTL, sc, sc - 1))
2349	<	transfer(tab, nextTab);
2346	>	int rs = resizeStamp(tab.length);
2347	>	while (nextTab == nextTable && table == tab &&
2348	>	(sc = sizeCtl) < 0) {
2349	>	if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
2350	>	sc == rs + MAX_RESIZERS || transferIndex <= 0)
2351	>	break;
2352	>	if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
2353	>	transfer(tab, nextTab);
2354	>	break;
2355	>	}
2356	>	}
2357		return nextTab;
2358		}
2359		return table;
#	Line 2235 | Line 2372 | public class ConcurrentHashMap<K,V> impl
2372		Node<K,V>[] tab = table; int n;
2373		if (tab == null || (n = tab.length) == 0) {
2374		n = (sc > c) ? sc : c;
2375	<	if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
2375	>	if (U.compareAndSetInt(this, SIZECTL, sc, -1)) {
2376		try {
2377		if (table == tab) {
2378	<	@SuppressWarnings({"rawtypes","unchecked"})
2379	<	Node<K,V>[] nt = (Node<K,V>[])new Node[n];
2378	>	@SuppressWarnings("unchecked")
2379	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
2380		table = nt;
2381		sc = n - (n >>> 2);
2382		}
#	Line 2250 | Line 2387 | public class ConcurrentHashMap<K,V> impl
2387		}
2388		else if (c <= sc || n >= MAXIMUM_CAPACITY)
2389		break;
2390	<	else if (tab == table &&
2391	<	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2392	<	transfer(tab, null);
2390	>	else if (tab == table) {
2391	>	int rs = resizeStamp(n);
2392	>	if (U.compareAndSetInt(this, SIZECTL, sc,
2393	>	(rs << RESIZE_STAMP_SHIFT) + 2))
2394	>	transfer(tab, null);
2395	>	}
2396		}
2397		}
2398
#	Line 2266 | Line 2406 | public class ConcurrentHashMap<K,V> impl
2406		stride = MIN_TRANSFER_STRIDE; // subdivide range
2407		if (nextTab == null) {            // initiating
2408		try {
2409	<	@SuppressWarnings({"rawtypes","unchecked"})
2410	<	Node<K,V>[] nt = (Node<K,V>[])new Node[n << 1];
2409	>	@SuppressWarnings("unchecked")
2410	>	Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
2411		nextTab = nt;
2412		} catch (Throwable ex) {      // try to cope with OOME
2413		sizeCtl = Integer.MAX_VALUE;
2414		return;
2415		}
2416		nextTable = nextTab;
2277	–	transferOrigin = n;
2417		transferIndex = n;
2279	–	ForwardingNode<K,V> rev = new ForwardingNode<K,V>(tab);
2280	–	for (int k = n; k > 0;) {    // progressively reveal ready slots
2281	–	int nextk = (k > stride) ? k - stride : 0;
2282	–	for (int m = nextk; m < k; ++m)
2283	–	nextTab[m] = rev;
2284	–	for (int m = n + nextk; m < n + k; ++m)
2285	–	nextTab[m] = rev;
2286	–	U.putOrderedInt(this, TRANSFERORIGIN, k = nextk);
2287	–	}
2418		}
2419		int nextn = nextTab.length;
2420		ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
2421		boolean advance = true;
2422	+	boolean finishing = false; // to ensure sweep before committing nextTab
2423		for (int i = 0, bound = 0;;) {
2424	<	int nextIndex, nextBound, fh; Node<K,V> f;
2424	>	Node<K,V> f; int fh;
2425		while (advance) {
2426	<	if (--i >= bound)
2426	>	int nextIndex, nextBound;
2427	>	if (--i >= bound || finishing)
2428		advance = false;
2429	<	else if ((nextIndex = transferIndex) <= transferOrigin) {
2429	>	else if ((nextIndex = transferIndex) <= 0) {
2430		i = -1;
2431		advance = false;
2432		}
2433	<	else if (U.compareAndSwapInt
2433	>	else if (U.compareAndSetInt
2434		(this, TRANSFERINDEX, nextIndex,
2435		nextBound = (nextIndex > stride ?
2436		nextIndex - stride : 0))) {
#	Line 2308 | Line 2440 | public class ConcurrentHashMap<K,V> impl
2440		}
2441		}
2442		if (i < 0 || i >= n || i + n >= nextn) {
2443	<	for (int sc;;) {
2444	<	if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) {
2445	<	if (sc == -1) {
2446	<	nextTable = null;
2447	<	table = nextTab;
2448	<	sizeCtl = (n << 1) - (n >>> 1);
2317	<	}
2318	<	return;
2319	<	}
2443	>	int sc;
2444	>	if (finishing) {
2445	>	nextTable = null;
2446	>	table = nextTab;
2447	>	sizeCtl = (n << 1) - (n >>> 1);
2448	>	return;
2449		}
2450	<	}
2451	<	else if ((f = tabAt(tab, i)) == null) {
2452	<	if (casTabAt(tab, i, null, fwd)) {
2453	<	setTabAt(nextTab, i, null);
2454	<	setTabAt(nextTab, i + n, null);
2326	<	advance = true;
2450	>	if (U.compareAndSetInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
2451	>	if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
2452	>	return;
2453	>	finishing = advance = true;
2454	>	i = n; // recheck before commit
2455		}
2456		}
2457	+	else if ((f = tabAt(tab, i)) == null)
2458	+	advance = casTabAt(tab, i, null, fwd);
2459		else if ((fh = f.hash) == MOVED)
2460		advance = true; // already processed
2461		else {
#	Line 2357 | Line 2487 | public class ConcurrentHashMap<K,V> impl
2487		else
2488		hn = new Node<K,V>(ph, pk, pv, hn);
2489		}
2490	+	setTabAt(nextTab, i, ln);
2491	+	setTabAt(nextTab, i + n, hn);
2492	+	setTabAt(tab, i, fwd);
2493	+	advance = true;
2494		}
2495		else if (f instanceof TreeBin) {
2496		TreeBin<K,V> t = (TreeBin<K,V>)f;
#	Line 2388 | Line 2522 | public class ConcurrentHashMap<K,V> impl
2522		(hc != 0) ? new TreeBin<K,V>(lo) : t;
2523		hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
2524		(lc != 0) ? new TreeBin<K,V>(hi) : t;
2525	+	setTabAt(nextTab, i, ln);
2526	+	setTabAt(nextTab, i + n, hn);
2527	+	setTabAt(tab, i, fwd);
2528	+	advance = true;
2529		}
2392	–	else
2393	–	ln = hn = null;
2394	–	setTabAt(nextTab, i, ln);
2395	–	setTabAt(nextTab, i + n, hn);
2396	–	setTabAt(tab, i, fwd);
2397	–	advance = true;
2530		}
2531		}
2532		}
#	Line 2407 | Line 2539 | public class ConcurrentHashMap<K,V> impl
2539		* A padded cell for distributing counts.  Adapted from LongAdder
2540		* and Striped64.  See their internal docs for explanation.
2541		*/
2542	<	@sun.misc.Contended static final class CounterCell {
2542	>	@jdk.internal.vm.annotation.Contended static final class CounterCell {
2543		volatile long value;
2544		CounterCell(long x) { value = x; }
2545		}
2546
2547		final long sumCount() {
2548	<	CounterCell[] as = counterCells; CounterCell a;
2548	>	CounterCell[] cs = counterCells;
2549		long sum = baseCount;
2550	<	if (as != null) {
2551	<	for (int i = 0; i < as.length; ++i) {
2552	<	if ((a = as[i]) != null)
2553	<	sum += a.value;
2422	<	}
2550	>	if (cs != null) {
2551	>	for (CounterCell c : cs)
2552	>	if (c != null)
2553	>	sum += c.value;
2554		}
2555		return sum;
2556		}
#	Line 2434 | Line 2565 | public class ConcurrentHashMap<K,V> impl
2565		}
2566		boolean collide = false;                // True if last slot nonempty
2567		for (;;) {
2568	<	CounterCell[] as; CounterCell a; int n; long v;
2569	<	if ((as = counterCells) != null && (n = as.length) > 0) {
2570	<	if ((a = as[(n - 1) & h]) == null) {
2568	>	CounterCell[] cs; CounterCell c; int n; long v;
2569	>	if ((cs = counterCells) != null && (n = cs.length) > 0) {
2570	>	if ((c = cs[(n - 1) & h]) == null) {
2571		if (cellsBusy == 0) {            // Try to attach new Cell
2572		CounterCell r = new CounterCell(x); // Optimistic create
2573		if (cellsBusy == 0 &&
2574	<	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2574	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2575		boolean created = false;
2576		try {               // Recheck under lock
2577		CounterCell[] rs; int m, j;
#	Line 2462 | Line 2593 | public class ConcurrentHashMap<K,V> impl
2593		}
2594		else if (!wasUncontended)       // CAS already known to fail
2595		wasUncontended = true;      // Continue after rehash
2596	<	else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
2596	>	else if (U.compareAndSetLong(c, CELLVALUE, v = c.value, v + x))
2597		break;
2598	<	else if (counterCells != as || n >= NCPU)
2598	>	else if (counterCells != cs || n >= NCPU)
2599		collide = false;            // At max size or stale
2600		else if (!collide)
2601		collide = true;
2602		else if (cellsBusy == 0 &&
2603	<	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2603	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2604		try {
2605	<	if (counterCells == as) {// Expand table unless stale
2606	<	CounterCell[] rs = new CounterCell[n << 1];
2476	<	for (int i = 0; i < n; ++i)
2477	<	rs[i] = as[i];
2478	<	counterCells = rs;
2479	<	}
2605	>	if (counterCells == cs) // Expand table unless stale
2606	>	counterCells = Arrays.copyOf(cs, n << 1);
2607		} finally {
2608		cellsBusy = 0;
2609		}
#	Line 2485 | Line 2612 | public class ConcurrentHashMap<K,V> impl
2612		}
2613		h = ThreadLocalRandom.advanceProbe(h);
2614		}
2615	<	else if (cellsBusy == 0 && counterCells == as &&
2616	<	U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
2615	>	else if (cellsBusy == 0 && counterCells == cs &&
2616	>	U.compareAndSetInt(this, CELLSBUSY, 0, 1)) {
2617		boolean init = false;
2618		try {                           // Initialize table
2619	<	if (counterCells == as) {
2619	>	if (counterCells == cs) {
2620		CounterCell[] rs = new CounterCell[2];
2621		rs[h & 1] = new CounterCell(x);
2622		counterCells = rs;
#	Line 2501 | Line 2628 | public class ConcurrentHashMap<K,V> impl
2628		if (init)
2629		break;
2630		}
2631	<	else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
2631	>	else if (U.compareAndSetLong(this, BASECOUNT, v = baseCount, v + x))
2632		break;                          // Fall back on using base
2633		}
2634		}
#	Line 2513 | Line 2640 | public class ConcurrentHashMap<K,V> impl
2640		* too small, in which case resizes instead.
2641		*/
2642		private final void treeifyBin(Node<K,V>[] tab, int index) {
2643	<	Node<K,V> b; int n, sc;
2643	>	Node<K,V> b; int n;
2644		if (tab != null) {
2645	<	if ((n = tab.length) < MIN_TREEIFY_CAPACITY) {
2646	<	if (tab == table && (sc = sizeCtl) >= 0 &&
2647	<	U.compareAndSwapInt(this, SIZECTL, sc, -2))
2521	<	transfer(tab, null);
2522	<	}
2523	<	else if ((b = tabAt(tab, index)) != null) {
2645	>	if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
2646	>	tryPresize(n << 1);
2647	>	else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
2648		synchronized (b) {
2649		if (tabAt(tab, index) == b) {
2650		TreeNode<K,V> hd = null, tl = null;
#	Line 2542 | Line 2666 | public class ConcurrentHashMap<K,V> impl
2666		}
2667
2668		/**
2669	<	* Returns a list on non-TreeNodes replacing those in given list
2669	>	* Returns a list of non-TreeNodes replacing those in given list.
2670		*/
2671		static <K,V> Node<K,V> untreeify(Node<K,V> b) {
2672		Node<K,V> hd = null, tl = null;
2673		for (Node<K,V> q = b; q != null; q = q.next) {
2674	<	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
2674	>	Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val);
2675		if (tl == null)
2676		hd = p;
2677		else
#	Line 2560 | Line 2684 | public class ConcurrentHashMap<K,V> impl
2684		/* ---------------- TreeNodes -------------- */
2685
2686		/**
2687	<	* Nodes for use in TreeBins
2687	>	* Nodes for use in TreeBins.
2688		*/
2689		static final class TreeNode<K,V> extends Node<K,V> {
2690		TreeNode<K,V> parent;  // red-black tree links
#	Line 2586 | Line 2710 | public class ConcurrentHashMap<K,V> impl
2710		final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
2711		if (k != null) {
2712		TreeNode<K,V> p = this;
2713	<	do  {
2713	>	do {
2714		int ph, dir; K pk; TreeNode<K,V> q;
2715		TreeNode<K,V> pl = p.left, pr = p.right;
2716		if ((ph = p.hash) > h)
#	Line 2595 | Line 2719 | public class ConcurrentHashMap<K,V> impl
2719		p = pr;
2720		else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
2721		return p;
2722	<	else if (pl == null && pr == null)
2723	<	break;
2722	>	else if (pl == null)
2723	>	p = pr;
2724	>	else if (pr == null)
2725	>	p = pl;
2726		else if ((kc != null ||
2727		(kc = comparableClassFor(k)) != null) &&
2728		(dir = compareComparables(kc, k, pk)) != 0)
2729		p = (dir < 0) ? pl : pr;
2730	<	else if (pl == null)
2605	<	p = pr;
2606	<	else if (pr == null ||
2607	<	(q = pr.findTreeNode(h, k, kc)) == null)
2608	<	p = pl;
2609	<	else
2730	>	else if ((q = pr.findTreeNode(h, k, kc)) != null)
2731		return q;
2732	+	else
2733	+	p = pl;
2734		} while (p != null);
2735		}
2736		return null;
#	Line 2634 | Line 2757 | public class ConcurrentHashMap<K,V> impl
2757		static final int READER = 4; // increment value for setting read lock
2758
2759		/**
2760	+	* Tie-breaking utility for ordering insertions when equal
2761	+	* hashCodes and non-comparable. We don't require a total
2762	+	* order, just a consistent insertion rule to maintain
2763	+	* equivalence across rebalancings. Tie-breaking further than
2764	+	* necessary simplifies testing a bit.
2765	+	*/
2766	+	static int tieBreakOrder(Object a, Object b) {
2767	+	int d;
2768	+	if (a == null || b == null ||
2769	+	(d = a.getClass().getName().
2770	+	compareTo(b.getClass().getName())) == 0)
2771	+	d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
2772	+	-1 : 1);
2773	+	return d;
2774	+	}
2775	+
2776	+	/**
2777		* Creates bin with initial set of nodes headed by b.
2778		*/
2779		TreeBin(TreeNode<K,V> b) {
2780	<	super(TREEBIN, null, null, null);
2780	>	super(TREEBIN, null, null);
2781		this.first = b;
2782		TreeNode<K,V> r = null;
2783		for (TreeNode<K,V> x = b, next; x != null; x = next) {
#	Line 2649 | Line 2789 | public class ConcurrentHashMap<K,V> impl
2789		r = x;
2790		}
2791		else {
2792	<	Object key = x.key;
2793	<	int hash = x.hash;
2792	>	K k = x.key;
2793	>	int h = x.hash;
2794		Class<?> kc = null;
2795		for (TreeNode<K,V> p = r;;) {
2796		int dir, ph;
2797	<	if ((ph = p.hash) > hash)
2797	>	K pk = p.key;
2798	>	if ((ph = p.hash) > h)
2799		dir = -1;
2800	<	else if (ph < hash)
2800	>	else if (ph < h)
2801		dir = 1;
2802	<	else if ((kc != null ||
2803	<	(kc = comparableClassFor(key)) != null))
2804	<	dir = compareComparables(kc, key, p.key);
2805	<	else
2665	<	dir = 0;
2802	>	else if ((kc == null &&
2803	>	(kc = comparableClassFor(k)) == null) ||
2804	>	(dir = compareComparables(kc, k, pk)) == 0)
2805	>	dir = tieBreakOrder(k, pk);
2806		TreeNode<K,V> xp = p;
2807		if ((p = (dir <= 0) ? p.left : p.right) == null) {
2808		x.parent = xp;
#	Line 2677 | Line 2817 | public class ConcurrentHashMap<K,V> impl
2817		}
2818		}
2819		this.root = r;
2820	+	assert checkInvariants(root);
2821		}
2822
2823		/**
2824	<	* Acquires write lock for tree restructuring
2824	>	* Acquires write lock for tree restructuring.
2825		*/
2826		private final void lockRoot() {
2827	<	if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
2827	>	if (!U.compareAndSetInt(this, LOCKSTATE, 0, WRITER))
2828		contendedLock(); // offload to separate method
2829		}
2830
2831		/**
2832	<	* Releases write lock for tree restructuring
2832	>	* Releases write lock for tree restructuring.
2833		*/
2834		private final void unlockRoot() {
2835		lockState = 0;
2836		}
2837
2838		/**
2839	<	* Possibly blocks awaiting root lock
2839	>	* Possibly blocks awaiting root lock.
2840		*/
2841		private final void contendedLock() {
2842		boolean waiting = false;
2843		for (int s;;) {
2844	<	if (((s = lockState) & WRITER) == 0) {
2845	<	if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
2844	>	if (((s = lockState) & ~WAITER) == 0) {
2845	>	if (U.compareAndSetInt(this, LOCKSTATE, s, WRITER)) {
2846		if (waiting)
2847		waiter = null;
2848		return;
2849		}
2850		}
2851	<	else if ((s | WAITER) == 0) {
2852	<	if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
2851	>	else if ((s & WAITER) == 0) {
2852	>	if (U.compareAndSetInt(this, LOCKSTATE, s, s | WAITER)) {
2853		waiting = true;
2854		waiter = Thread.currentThread();
2855		}
#	Line 2720 | Line 2861 | public class ConcurrentHashMap<K,V> impl
2861
2862		/**
2863		* Returns matching node or null if none. Tries to search
2864	<	* using tree compareisons from root, but continues linear
2864	>	* using tree comparisons from root, but continues linear
2865		* search when lock not available.
2866		*/
2867		final Node<K,V> find(int h, Object k) {
2868		if (k != null) {
2869	<	for (Node<K,V> e = first; e != null; e = e.next) {
2869	>	for (Node<K,V> e = first; e != null; ) {
2870		int s; K ek;
2871		if (((s = lockState) & (WAITER|WRITER)) != 0) {
2872		if (e.hash == h &&
2873		((ek = e.key) == k || (ek != null && k.equals(ek))))
2874		return e;
2875	+	e = e.next;
2876		}
2877	<	else if (U.compareAndSwapInt(this, LOCKSTATE, s,
2877	>	else if (U.compareAndSetInt(this, LOCKSTATE, s,
2878		s + READER)) {
2879		TreeNode<K,V> r, p;
2880		try {
#	Line 2757 | Line 2899 | public class ConcurrentHashMap<K,V> impl
2899		*/
2900		final TreeNode<K,V> putTreeVal(int h, K k, V v) {
2901		Class<?> kc = null;
2902	+	boolean searched = false;
2903		for (TreeNode<K,V> p = root;;) {
2904	<	int dir, ph; K pk; TreeNode<K,V> q, pr;
2904	>	int dir, ph; K pk;
2905		if (p == null) {
2906		first = root = new TreeNode<K,V>(h, k, v, null, null);
2907		break;
#	Line 2772 | Line 2915 | public class ConcurrentHashMap<K,V> impl
2915		else if ((kc == null &&
2916		(kc = comparableClassFor(k)) == null) ||
2917		(dir = compareComparables(kc, k, pk)) == 0) {
2918	<	if (p.left == null)
2919	<	dir = 1;
2920	<	else if ((pr = p.right) == null ||
2921	<	(q = pr.findTreeNode(h, k, kc)) == null)
2922	<	dir = -1;
2923	<	else
2924	<	return q;
2918	>	if (!searched) {
2919	>	TreeNode<K,V> q, ch;
2920	>	searched = true;
2921	>	if (((ch = p.left) != null &&
2922	>	(q = ch.findTreeNode(h, k, kc)) != null) ||
2923	>	((ch = p.right) != null &&
2924	>	(q = ch.findTreeNode(h, k, kc)) != null))
2925	>	return q;
2926	>	}
2927	>	dir = tieBreakOrder(k, pk);
2928		}
2929	+
2930		TreeNode<K,V> xp = p;
2931	<	if ((p = (dir < 0) ? p.left : p.right) == null) {
2931	>	if ((p = (dir <= 0) ? p.left : p.right) == null) {
2932		TreeNode<K,V> x, f = first;
2933		first = x = new TreeNode<K,V>(h, k, v, f, xp);
2934		if (f != null)
2935		f.prev = x;
2936	<	if (dir < 0)
2936	>	if (dir <= 0)
2937		xp.left = x;
2938		else
2939		xp.right = x;
#	Line 2815 | Line 2962 | public class ConcurrentHashMap<K,V> impl
2962		* that are accessible independently of lock. So instead we
2963		* swap the tree linkages.
2964		*
2965	<	* @return true if now too small so should be untreeified.
2965	>	* @return true if now too small, so should be untreeified
2966		*/
2967		final boolean removeTreeNode(TreeNode<K,V> p) {
2968		TreeNode<K,V> next = (TreeNode<K,V>)p.next;
#	Line 3009 | Line 3156 | public class ConcurrentHashMap<K,V> impl
3156
3157		static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
3158		TreeNode<K,V> x) {
3159	<	for (TreeNode<K,V> xp, xpl, xpr;;)  {
3159	>	for (TreeNode<K,V> xp, xpl, xpr;;) {
3160		if (x == null || x == root)
3161		return root;
3162		else if ((xp = x.parent) == null) {
#	Line 3100 | Line 3247 | public class ConcurrentHashMap<K,V> impl
3247		}
3248
3249		/**
3250	<	* Recursive invariant check
3250	>	* Checks invariants recursively for the tree of Nodes rooted at t.
3251		*/
3252		static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
3253		TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
#	Line 3124 | Line 3271 | public class ConcurrentHashMap<K,V> impl
3271		return true;
3272		}
3273
3274	<	private static final sun.misc.Unsafe U;
3274	>	private static final Unsafe U = Unsafe.getUnsafe();
3275		private static final long LOCKSTATE;
3276		static {
3277		try {
3131	–	U = sun.misc.Unsafe.getUnsafe();
3132	–	Class<?> k = TreeBin.class;
3278		LOCKSTATE = U.objectFieldOffset
3279	<	(k.getDeclaredField("lockState"));
3280	<	} catch (Exception e) {
3281	<	throw new Error(e);
3279	>	(TreeBin.class.getDeclaredField("lockState"));
3280	>	} catch (ReflectiveOperationException e) {
3281	>	throw new ExceptionInInitializerError(e);
3282		}
3283		}
3284		}
#	Line 3141 | Line 3286 | public class ConcurrentHashMap<K,V> impl
3286		/* ----------------Table Traversal -------------- */
3287
3288		/**
3289	+	* Records the table, its length, and current traversal index for a
3290	+	* traverser that must process a region of a forwarded table before
3291	+	* proceeding with current table.
3292	+	*/
3293	+	static final class TableStack<K,V> {
3294	+	int length;
3295	+	int index;
3296	+	Node<K,V>[] tab;
3297	+	TableStack<K,V> next;
3298	+	}
3299	+
3300	+	/**
3301		* Encapsulates traversal for methods such as containsValue; also
3302		* serves as a base class for other iterators and spliterators.
3303		*
#	Line 3164 | Line 3321 | public class ConcurrentHashMap<K,V> impl
3321		static class Traverser<K,V> {
3322		Node<K,V>[] tab;        // current table; updated if resized
3323		Node<K,V> next;         // the next entry to use
3324	+	TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
3325		int index;              // index of bin to use next
3326		int baseIndex;          // current index of initial table
3327		int baseLimit;          // index bound for initial table
#	Line 3185 | Line 3343 | public class ConcurrentHashMap<K,V> impl
3343		if ((e = next) != null)
3344		e = e.next;
3345		for (;;) {
3346	<	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
3346	>	Node<K,V>[] t; int i, n;  // must use locals in checks
3347		if (e != null)
3348		return next = e;
3349		if (baseIndex >= baseLimit || (t = tab) == null ||
3350		(n = t.length) <= (i = index) || i < 0)
3351		return next = null;
3352	<	if ((e = tabAt(t, index)) != null && e.hash < 0) {
3352	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
3353		if (e instanceof ForwardingNode) {
3354		tab = ((ForwardingNode<K,V>)e).nextTable;
3355		e = null;
3356	+	pushState(t, i, n);
3357		continue;
3358		}
3359		else if (e instanceof TreeBin)
#	Line 3202 | Line 3361 | public class ConcurrentHashMap<K,V> impl
3361		else
3362		e = null;
3363		}
3364	<	if ((index += baseSize) >= n)
3365	<	index = ++baseIndex;    // visit upper slots if present
3364	>	if (stack != null)
3365	>	recoverState(n);
3366	>	else if ((index = i + baseSize) >= n)
3367	>	index = ++baseIndex; // visit upper slots if present
3368	>	}
3369	>	}
3370	>
3371	>	/**
3372	>	* Saves traversal state upon encountering a forwarding node.
3373	>	*/
3374	>	private void pushState(Node<K,V>[] t, int i, int n) {
3375	>	TableStack<K,V> s = spare;  // reuse if possible
3376	>	if (s != null)
3377	>	spare = s.next;
3378	>	else
3379	>	s = new TableStack<K,V>();
3380	>	s.tab = t;
3381	>	s.length = n;
3382	>	s.index = i;
3383	>	s.next = stack;
3384	>	stack = s;
3385	>	}
3386	>
3387	>	/**
3388	>	* Possibly pops traversal state.
3389	>	*
3390	>	* @param n length of current table
3391	>	*/
3392	>	private void recoverState(int n) {
3393	>	TableStack<K,V> s; int len;
3394	>	while ((s = stack) != null && (index += (len = s.length)) >= n) {
3395	>	n = len;
3396	>	index = s.index;
3397	>	tab = s.tab;
3398	>	s.tab = null;
3399	>	TableStack<K,V> next = s.next;
3400	>	s.next = spare; // save for reuse
3401	>	stack = next;
3402	>	spare = s;
3403		}
3404	+	if (s == null && (index += baseSize) >= n)
3405	+	index = ++baseIndex;
3406		}
3407		}
3408
3409		/**
3410		* Base of key, value, and entry Iterators. Adds fields to
3411	<	* Traverser to support iterator.remove
3411	>	* Traverser to support iterator.remove.
3412		*/
3413		static class BaseIterator<K,V> extends Traverser<K,V> {
3414		final ConcurrentHashMap<K,V> map;
#	Line 3236 | Line 3434 | public class ConcurrentHashMap<K,V> impl
3434
3435		static final class KeyIterator<K,V> extends BaseIterator<K,V>
3436		implements Iterator<K>, Enumeration<K> {
3437	<	KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
3437	>	KeyIterator(Node<K,V>[] tab, int size, int index, int limit,
3438		ConcurrentHashMap<K,V> map) {
3439	<	super(tab, index, size, limit, map);
3439	>	super(tab, size, index, limit, map);
3440		}
3441
3442		public final K next() {
#	Line 3256 | Line 3454 | public class ConcurrentHashMap<K,V> impl
3454
3455		static final class ValueIterator<K,V> extends BaseIterator<K,V>
3456		implements Iterator<V>, Enumeration<V> {
3457	<	ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
3457	>	ValueIterator(Node<K,V>[] tab, int size, int index, int limit,
3458		ConcurrentHashMap<K,V> map) {
3459	<	super(tab, index, size, limit, map);
3459	>	super(tab, size, index, limit, map);
3460		}
3461
3462		public final V next() {
#	Line 3276 | Line 3474 | public class ConcurrentHashMap<K,V> impl
3474
3475		static final class EntryIterator<K,V> extends BaseIterator<K,V>
3476		implements Iterator<Map.Entry<K,V>> {
3477	<	EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
3477	>	EntryIterator(Node<K,V>[] tab, int size, int index, int limit,
3478		ConcurrentHashMap<K,V> map) {
3479	<	super(tab, index, size, limit, map);
3479	>	super(tab, size, index, limit, map);
3480		}
3481
3482		public final Map.Entry<K,V> next() {
#	Line 3294 | Line 3492 | public class ConcurrentHashMap<K,V> impl
3492		}
3493
3494		/**
3495	<	* Exported Entry for EntryIterator
3495	>	* Exported Entry for EntryIterator.
3496		*/
3497		static final class MapEntry<K,V> implements Map.Entry<K,V> {
3498		final K key; // non-null
#	Line 3308 | Line 3506 | public class ConcurrentHashMap<K,V> impl
3506		public K getKey()        { return key; }
3507		public V getValue()      { return val; }
3508		public int hashCode()    { return key.hashCode() ^ val.hashCode(); }
3509	<	public String toString() { return key + "=" + val; }
3509	>	public String toString() {
3510	>	return Helpers.mapEntryToString(key, val);
3511	>	}
3512
3513		public boolean equals(Object o) {
3514		Object k, v; Map.Entry<?,?> e;
#	Line 3345 | Line 3545 | public class ConcurrentHashMap<K,V> impl
3545		this.est = est;
3546		}
3547
3548	<	public Spliterator<K> trySplit() {
3548	>	public KeySpliterator<K,V> trySplit() {
3549		int i, f, h;
3550		return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3551		new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
#	Line 3384 | Line 3584 | public class ConcurrentHashMap<K,V> impl
3584		this.est = est;
3585		}
3586
3587	<	public Spliterator<V> trySplit() {
3587	>	public ValueSpliterator<K,V> trySplit() {
3588		int i, f, h;
3589		return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3590		new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
#	Line 3424 | Line 3624 | public class ConcurrentHashMap<K,V> impl
3624		this.est = est;
3625		}
3626
3627	<	public Spliterator<Map.Entry<K,V>> trySplit() {
3627	>	public EntrySpliterator<K,V> trySplit() {
3628		int i, f, h;
3629		return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
3630		new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
#	Line 3498 | Line 3698 | public class ConcurrentHashMap<K,V> impl
3698		* for an element, or null if there is no transformation (in
3699		* which case the action is not applied)
3700		* @param action the action
3701	+	* @param <U> the return type of the transformer
3702		* @since 1.8
3703		*/
3704		public <U> void forEach(long parallelismThreshold,
#	Line 3521 | Line 3722 | public class ConcurrentHashMap<K,V> impl
3722		* needed for this operation to be executed in parallel
3723		* @param searchFunction a function returning a non-null
3724		* result on success, else null
3725	+	* @param <U> the return type of the search function
3726		* @return a non-null result from applying the given search
3727		* function on each (key, value), or null if none
3728		* @since 1.8
#	Line 3544 | Line 3746 | public class ConcurrentHashMap<K,V> impl
3746		* for an element, or null if there is no transformation (in
3747		* which case it is not combined)
3748		* @param reducer a commutative associative combining function
3749	+	* @param <U> the return type of the transformer
3750		* @return the result of accumulating the given transformation
3751		* of all (key, value) pairs
3752		* @since 1.8
#	Line 3573 | Line 3776 | public class ConcurrentHashMap<K,V> impl
3776		* of all (key, value) pairs
3777		* @since 1.8
3778		*/
3779	<	public double reduceToDoubleIn(long parallelismThreshold,
3780	<	ToDoubleBiFunction<? super K, ? super V> transformer,
3781	<	double basis,
3782	<	DoubleBinaryOperator reducer) {
3779	>	public double reduceToDouble(long parallelismThreshold,
3780	>	ToDoubleBiFunction<? super K, ? super V> transformer,
3781	>	double basis,
3782	>	DoubleBinaryOperator reducer) {
3783		if (transformer == null || reducer == null)
3784		throw new NullPointerException();
3785		return new MapReduceMappingsToDoubleTask<K,V>
#	Line 3662 | Line 3865 | public class ConcurrentHashMap<K,V> impl
3865		* for an element, or null if there is no transformation (in
3866		* which case the action is not applied)
3867		* @param action the action
3868	+	* @param <U> the return type of the transformer
3869		* @since 1.8
3870		*/
3871		public <U> void forEachKey(long parallelismThreshold,
#	Line 3685 | Line 3889 | public class ConcurrentHashMap<K,V> impl
3889		* needed for this operation to be executed in parallel
3890		* @param searchFunction a function returning a non-null
3891		* result on success, else null
3892	+	* @param <U> the return type of the search function
3893		* @return a non-null result from applying the given search
3894		* function on each key, or null if none
3895		* @since 1.8
#	Line 3727 | Line 3932 | public class ConcurrentHashMap<K,V> impl
3932		* for an element, or null if there is no transformation (in
3933		* which case it is not combined)
3934		* @param reducer a commutative associative combining function
3935	+	* @param <U> the return type of the transformer
3936		* @return the result of accumulating the given transformation
3937		* of all keys
3938		* @since 1.8
#	Line 3846 | Line 4052 | public class ConcurrentHashMap<K,V> impl
4052		* for an element, or null if there is no transformation (in
4053		* which case the action is not applied)
4054		* @param action the action
4055	+	* @param <U> the return type of the transformer
4056		* @since 1.8
4057		*/
4058		public <U> void forEachValue(long parallelismThreshold,
#	Line 3869 | Line 4076 | public class ConcurrentHashMap<K,V> impl
4076		* needed for this operation to be executed in parallel
4077		* @param searchFunction a function returning a non-null
4078		* result on success, else null
4079	+	* @param <U> the return type of the search function
4080		* @return a non-null result from applying the given search
4081		* function on each value, or null if none
4082		* @since 1.8
#	Line 3910 | Line 4118 | public class ConcurrentHashMap<K,V> impl
4118		* for an element, or null if there is no transformation (in
4119		* which case it is not combined)
4120		* @param reducer a commutative associative combining function
4121	+	* @param <U> the return type of the transformer
4122		* @return the result of accumulating the given transformation
4123		* of all values
4124		* @since 1.8
#	Line 4027 | Line 4236 | public class ConcurrentHashMap<K,V> impl
4236		* for an element, or null if there is no transformation (in
4237		* which case the action is not applied)
4238		* @param action the action
4239	+	* @param <U> the return type of the transformer
4240		* @since 1.8
4241		*/
4242		public <U> void forEachEntry(long parallelismThreshold,
#	Line 4050 | Line 4260 | public class ConcurrentHashMap<K,V> impl
4260		* needed for this operation to be executed in parallel
4261		* @param searchFunction a function returning a non-null
4262		* result on success, else null
4263	+	* @param <U> the return type of the search function
4264		* @return a non-null result from applying the given search
4265		* function on each entry, or null if none
4266		* @since 1.8
#	Line 4091 | Line 4302 | public class ConcurrentHashMap<K,V> impl
4302		* for an element, or null if there is no transformation (in
4303		* which case it is not combined)
4304		* @param reducer a commutative associative combining function
4305	+	* @param <U> the return type of the transformer
4306		* @return the result of accumulating the given transformation
4307		* of all entries
4308		* @since 1.8
#	Line 4213 | Line 4425 | public class ConcurrentHashMap<K,V> impl
4425		// implementations below rely on concrete classes supplying these
4426		// abstract methods
4427		/**
4428	<	* Returns a "weakly consistent" iterator that will never
4429	<	* throw {@link ConcurrentModificationException}, and
4430	<	* guarantees to traverse elements as they existed upon
4431	<	* construction of the iterator, and may (but is not
4432	<	* guaranteed to) reflect any modifications subsequent to
4433	<	* construction.
4428	>	* Returns an iterator over the elements in this collection.
4429	>	*
4430	>	* <p>The returned iterator is
4431	>	* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
4432	>	*
4433	>	* @return an iterator over the elements in this collection
4434		*/
4435		public abstract Iterator<E> iterator();
4436		public abstract boolean contains(Object o);
4437		public abstract boolean remove(Object o);
4438
4439	<	private static final String oomeMsg = "Required array size too large";
4439	>	private static final String OOME_MSG = "Required array size too large";
4440
4441		public final Object[] toArray() {
4442		long sz = map.mappingCount();
4443		if (sz > MAX_ARRAY_SIZE)
4444	<	throw new OutOfMemoryError(oomeMsg);
4444	>	throw new OutOfMemoryError(OOME_MSG);
4445		int n = (int)sz;
4446		Object[] r = new Object[n];
4447		int i = 0;
4448		for (E e : this) {
4449		if (i == n) {
4450		if (n >= MAX_ARRAY_SIZE)
4451	<	throw new OutOfMemoryError(oomeMsg);
4451	>	throw new OutOfMemoryError(OOME_MSG);
4452		if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4453		n = MAX_ARRAY_SIZE;
4454		else
#	Line 4252 | Line 4464 | public class ConcurrentHashMap<K,V> impl
4464		public final <T> T[] toArray(T[] a) {
4465		long sz = map.mappingCount();
4466		if (sz > MAX_ARRAY_SIZE)
4467	<	throw new OutOfMemoryError(oomeMsg);
4467	>	throw new OutOfMemoryError(OOME_MSG);
4468		int m = (int)sz;
4469		T[] r = (a.length >= m) ? a :
4470		(T[])java.lang.reflect.Array
#	Line 4262 | Line 4474 | public class ConcurrentHashMap<K,V> impl
4474		for (E e : this) {
4475		if (i == n) {
4476		if (n >= MAX_ARRAY_SIZE)
4477	<	throw new OutOfMemoryError(oomeMsg);
4477	>	throw new OutOfMemoryError(OOME_MSG);
4478		if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
4479		n = MAX_ARRAY_SIZE;
4480		else
#	Line 4315 | Line 4527 | public class ConcurrentHashMap<K,V> impl
4527		return true;
4528		}
4529
4530	<	public final boolean removeAll(Collection<?> c) {
4530	>	public boolean removeAll(Collection<?> c) {
4531	>	if (c == null) throw new NullPointerException();
4532		boolean modified = false;
4533	<	for (Iterator<E> it = iterator(); it.hasNext();) {
4534	<	if (c.contains(it.next())) {
4535	<	it.remove();
4536	<	modified = true;
4533	>	// Use (c instanceof Set) as a hint that lookup in c is as
4534	>	// efficient as this view
4535	>	Node<K,V>[] t;
4536	>	if ((t = map.table) == null) {
4537	>	return false;
4538	>	} else if (c instanceof Set<?> && c.size() > t.length) {
4539	>	for (Iterator<?> it = iterator(); it.hasNext(); ) {
4540	>	if (c.contains(it.next())) {
4541	>	it.remove();
4542	>	modified = true;
4543	>	}
4544		}
4545	+	} else {
4546	+	for (Object e : c)
4547	+	modified |= remove(e);
4548		}
4549		return modified;
4550		}
4551
4552		public final boolean retainAll(Collection<?> c) {
4553	+	if (c == null) throw new NullPointerException();
4554		boolean modified = false;
4555		for (Iterator<E> it = iterator(); it.hasNext();) {
4556		if (!c.contains(it.next())) {
#	Line 4507 | Line 4731 | public class ConcurrentHashMap<K,V> impl
4731		throw new UnsupportedOperationException();
4732		}
4733
4734	+	@Override public boolean removeAll(Collection<?> c) {
4735	+	if (c == null) throw new NullPointerException();
4736	+	boolean modified = false;
4737	+	for (Iterator<V> it = iterator(); it.hasNext();) {
4738	+	if (c.contains(it.next())) {
4739	+	it.remove();
4740	+	modified = true;
4741	+	}
4742	+	}
4743	+	return modified;
4744	+	}
4745	+
4746	+	public boolean removeIf(Predicate<? super V> filter) {
4747	+	return map.removeValueIf(filter);
4748	+	}
4749	+
4750		public Spliterator<V> spliterator() {
4751		Node<K,V>[] t;
4752		ConcurrentHashMap<K,V> m = map;
#	Line 4576 | Line 4816 | public class ConcurrentHashMap<K,V> impl
4816		return added;
4817		}
4818
4819	+	public boolean removeIf(Predicate<? super Entry<K,V>> filter) {
4820	+	return map.removeEntryIf(filter);
4821	+	}
4822	+
4823		public final int hashCode() {
4824		int h = 0;
4825		Node<K,V>[] t;
#	Line 4621 | Line 4865 | public class ConcurrentHashMap<K,V> impl
4865		* Base class for bulk tasks. Repeats some fields and code from
4866		* class Traverser, because we need to subclass CountedCompleter.
4867		*/
4868	+	@SuppressWarnings("serial")
4869		abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
4870		Node<K,V>[] tab;        // same as Traverser
4871		Node<K,V> next;
4872	+	TableStack<K,V> stack, spare;
4873		int index;
4874		int baseIndex;
4875		int baseLimit;
#	Line 4645 | Line 4891 | public class ConcurrentHashMap<K,V> impl
4891		}
4892
4893		/**
4894	<	* Same as Traverser version
4894	>	* Same as Traverser version.
4895		*/
4896		final Node<K,V> advance() {
4897		Node<K,V> e;
4898		if ((e = next) != null)
4899		e = e.next;
4900		for (;;) {
4901	<	Node<K,V>[] t; int i, n; K ek;  // must use locals in checks
4901	>	Node<K,V>[] t; int i, n;
4902		if (e != null)
4903		return next = e;
4904		if (baseIndex >= baseLimit || (t = tab) == null ||
4905		(n = t.length) <= (i = index) || i < 0)
4906		return next = null;
4907	<	if ((e = tabAt(t, index)) != null && e.hash < 0) {
4907	>	if ((e = tabAt(t, i)) != null && e.hash < 0) {
4908		if (e instanceof ForwardingNode) {
4909		tab = ((ForwardingNode<K,V>)e).nextTable;
4910		e = null;
4911	+	pushState(t, i, n);
4912		continue;
4913		}
4914		else if (e instanceof TreeBin)
#	Line 4669 | Line 4916 | public class ConcurrentHashMap<K,V> impl
4916		else
4917		e = null;
4918		}
4919	<	if ((index += baseSize) >= n)
4920	<	index = ++baseIndex;    // visit upper slots if present
4919	>	if (stack != null)
4920	>	recoverState(n);
4921	>	else if ((index = i + baseSize) >= n)
4922	>	index = ++baseIndex;
4923		}
4924		}
4925	+
4926	+	private void pushState(Node<K,V>[] t, int i, int n) {
4927	+	TableStack<K,V> s = spare;
4928	+	if (s != null)
4929	+	spare = s.next;
4930	+	else
4931	+	s = new TableStack<K,V>();
4932	+	s.tab = t;
4933	+	s.length = n;
4934	+	s.index = i;
4935	+	s.next = stack;
4936	+	stack = s;
4937	+	}
4938	+
4939	+	private void recoverState(int n) {
4940	+	TableStack<K,V> s; int len;
4941	+	while ((s = stack) != null && (index += (len = s.length)) >= n) {
4942	+	n = len;
4943	+	index = s.index;
4944	+	tab = s.tab;
4945	+	s.tab = null;
4946	+	TableStack<K,V> next = s.next;
4947	+	s.next = spare; // save for reuse
4948	+	stack = next;
4949	+	spare = s;
4950	+	}
4951	+	if (s == null && (index += baseSize) >= n)
4952	+	index = ++baseIndex;
4953	+	}
4954		}
4955
4956		/*
#	Line 5131 | Line 5409 | public class ConcurrentHashMap<K,V> impl
5409		result = r;
5410		CountedCompleter<?> c;
5411		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5412	<	@SuppressWarnings("unchecked") ReduceKeysTask<K,V>
5412	>	@SuppressWarnings("unchecked")
5413	>	ReduceKeysTask<K,V>
5414		t = (ReduceKeysTask<K,V>)c,
5415		s = t.rights;
5416		while (s != null) {
#	Line 5178 | Line 5457 | public class ConcurrentHashMap<K,V> impl
5457		result = r;
5458		CountedCompleter<?> c;
5459		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5460	<	@SuppressWarnings("unchecked") ReduceValuesTask<K,V>
5460	>	@SuppressWarnings("unchecked")
5461	>	ReduceValuesTask<K,V>
5462		t = (ReduceValuesTask<K,V>)c,
5463		s = t.rights;
5464		while (s != null) {
#	Line 5223 | Line 5503 | public class ConcurrentHashMap<K,V> impl
5503		result = r;
5504		CountedCompleter<?> c;
5505		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5506	<	@SuppressWarnings("unchecked") ReduceEntriesTask<K,V>
5506	>	@SuppressWarnings("unchecked")
5507	>	ReduceEntriesTask<K,V>
5508		t = (ReduceEntriesTask<K,V>)c,
5509		s = t.rights;
5510		while (s != null) {
#	Line 5276 | Line 5557 | public class ConcurrentHashMap<K,V> impl
5557		result = r;
5558		CountedCompleter<?> c;
5559		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5560	<	@SuppressWarnings("unchecked") MapReduceKeysTask<K,V,U>
5560	>	@SuppressWarnings("unchecked")
5561	>	MapReduceKeysTask<K,V,U>
5562		t = (MapReduceKeysTask<K,V,U>)c,
5563		s = t.rights;
5564		while (s != null) {
#	Line 5329 | Line 5611 | public class ConcurrentHashMap<K,V> impl
5611		result = r;
5612		CountedCompleter<?> c;
5613		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5614	<	@SuppressWarnings("unchecked") MapReduceValuesTask<K,V,U>
5614	>	@SuppressWarnings("unchecked")
5615	>	MapReduceValuesTask<K,V,U>
5616		t = (MapReduceValuesTask<K,V,U>)c,
5617		s = t.rights;
5618		while (s != null) {
#	Line 5382 | Line 5665 | public class ConcurrentHashMap<K,V> impl
5665		result = r;
5666		CountedCompleter<?> c;
5667		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5668	<	@SuppressWarnings("unchecked") MapReduceEntriesTask<K,V,U>
5668	>	@SuppressWarnings("unchecked")
5669	>	MapReduceEntriesTask<K,V,U>
5670		t = (MapReduceEntriesTask<K,V,U>)c,
5671		s = t.rights;
5672		while (s != null) {
#	Line 5435 | Line 5719 | public class ConcurrentHashMap<K,V> impl
5719		result = r;
5720		CountedCompleter<?> c;
5721		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5722	<	@SuppressWarnings("unchecked") MapReduceMappingsTask<K,V,U>
5722	>	@SuppressWarnings("unchecked")
5723	>	MapReduceMappingsTask<K,V,U>
5724		t = (MapReduceMappingsTask<K,V,U>)c,
5725		s = t.rights;
5726		while (s != null) {
#	Line 5487 | Line 5772 | public class ConcurrentHashMap<K,V> impl
5772		result = r;
5773		CountedCompleter<?> c;
5774		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5775	<	@SuppressWarnings("unchecked") MapReduceKeysToDoubleTask<K,V>
5775	>	@SuppressWarnings("unchecked")
5776	>	MapReduceKeysToDoubleTask<K,V>
5777		t = (MapReduceKeysToDoubleTask<K,V>)c,
5778		s = t.rights;
5779		while (s != null) {
#	Line 5536 | Line 5822 | public class ConcurrentHashMap<K,V> impl
5822		result = r;
5823		CountedCompleter<?> c;
5824		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5825	<	@SuppressWarnings("unchecked") MapReduceValuesToDoubleTask<K,V>
5825	>	@SuppressWarnings("unchecked")
5826	>	MapReduceValuesToDoubleTask<K,V>
5827		t = (MapReduceValuesToDoubleTask<K,V>)c,
5828		s = t.rights;
5829		while (s != null) {
#	Line 5585 | Line 5872 | public class ConcurrentHashMap<K,V> impl
5872		result = r;
5873		CountedCompleter<?> c;
5874		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5875	<	@SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask<K,V>
5875	>	@SuppressWarnings("unchecked")
5876	>	MapReduceEntriesToDoubleTask<K,V>
5877		t = (MapReduceEntriesToDoubleTask<K,V>)c,
5878		s = t.rights;
5879		while (s != null) {
#	Line 5634 | Line 5922 | public class ConcurrentHashMap<K,V> impl
5922		result = r;
5923		CountedCompleter<?> c;
5924		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5925	<	@SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask<K,V>
5925	>	@SuppressWarnings("unchecked")
5926	>	MapReduceMappingsToDoubleTask<K,V>
5927		t = (MapReduceMappingsToDoubleTask<K,V>)c,
5928		s = t.rights;
5929		while (s != null) {
#	Line 5683 | Line 5972 | public class ConcurrentHashMap<K,V> impl
5972		result = r;
5973		CountedCompleter<?> c;
5974		for (c = firstComplete(); c != null; c = c.nextComplete()) {
5975	<	@SuppressWarnings("unchecked") MapReduceKeysToLongTask<K,V>
5975	>	@SuppressWarnings("unchecked")
5976	>	MapReduceKeysToLongTask<K,V>
5977		t = (MapReduceKeysToLongTask<K,V>)c,
5978		s = t.rights;
5979		while (s != null) {
#	Line 5732 | Line 6022 | public class ConcurrentHashMap<K,V> impl
6022		result = r;
6023		CountedCompleter<?> c;
6024		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6025	<	@SuppressWarnings("unchecked") MapReduceValuesToLongTask<K,V>
6025	>	@SuppressWarnings("unchecked")
6026	>	MapReduceValuesToLongTask<K,V>
6027		t = (MapReduceValuesToLongTask<K,V>)c,
6028		s = t.rights;
6029		while (s != null) {
#	Line 5781 | Line 6072 | public class ConcurrentHashMap<K,V> impl
6072		result = r;
6073		CountedCompleter<?> c;
6074		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6075	<	@SuppressWarnings("unchecked") MapReduceEntriesToLongTask<K,V>
6075	>	@SuppressWarnings("unchecked")
6076	>	MapReduceEntriesToLongTask<K,V>
6077		t = (MapReduceEntriesToLongTask<K,V>)c,
6078		s = t.rights;
6079		while (s != null) {
#	Line 5830 | Line 6122 | public class ConcurrentHashMap<K,V> impl
6122		result = r;
6123		CountedCompleter<?> c;
6124		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6125	<	@SuppressWarnings("unchecked") MapReduceMappingsToLongTask<K,V>
6125	>	@SuppressWarnings("unchecked")
6126	>	MapReduceMappingsToLongTask<K,V>
6127		t = (MapReduceMappingsToLongTask<K,V>)c,
6128		s = t.rights;
6129		while (s != null) {
#	Line 5879 | Line 6172 | public class ConcurrentHashMap<K,V> impl
6172		result = r;
6173		CountedCompleter<?> c;
6174		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6175	<	@SuppressWarnings("unchecked") MapReduceKeysToIntTask<K,V>
6175	>	@SuppressWarnings("unchecked")
6176	>	MapReduceKeysToIntTask<K,V>
6177		t = (MapReduceKeysToIntTask<K,V>)c,
6178		s = t.rights;
6179		while (s != null) {
#	Line 5928 | Line 6222 | public class ConcurrentHashMap<K,V> impl
6222		result = r;
6223		CountedCompleter<?> c;
6224		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6225	<	@SuppressWarnings("unchecked") MapReduceValuesToIntTask<K,V>
6225	>	@SuppressWarnings("unchecked")
6226	>	MapReduceValuesToIntTask<K,V>
6227		t = (MapReduceValuesToIntTask<K,V>)c,
6228		s = t.rights;
6229		while (s != null) {
#	Line 5977 | Line 6272 | public class ConcurrentHashMap<K,V> impl
6272		result = r;
6273		CountedCompleter<?> c;
6274		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6275	<	@SuppressWarnings("unchecked") MapReduceEntriesToIntTask<K,V>
6275	>	@SuppressWarnings("unchecked")
6276	>	MapReduceEntriesToIntTask<K,V>
6277		t = (MapReduceEntriesToIntTask<K,V>)c,
6278		s = t.rights;
6279		while (s != null) {
#	Line 6026 | Line 6322 | public class ConcurrentHashMap<K,V> impl
6322		result = r;
6323		CountedCompleter<?> c;
6324		for (c = firstComplete(); c != null; c = c.nextComplete()) {
6325	<	@SuppressWarnings("unchecked") MapReduceMappingsToIntTask<K,V>
6325	>	@SuppressWarnings("unchecked")
6326	>	MapReduceMappingsToIntTask<K,V>
6327		t = (MapReduceMappingsToIntTask<K,V>)c,
6328		s = t.rights;
6329		while (s != null) {
#	Line 6039 | Line 6336 | public class ConcurrentHashMap<K,V> impl
6336		}
6337
6338		// Unsafe mechanics
6339	<	private static final sun.misc.Unsafe U;
6339	>	private static final Unsafe U = Unsafe.getUnsafe();
6340		private static final long SIZECTL;
6341		private static final long TRANSFERINDEX;
6045	–	private static final long TRANSFERORIGIN;
6342		private static final long BASECOUNT;
6343		private static final long CELLSBUSY;
6344		private static final long CELLVALUE;
6345	<	private static final long ABASE;
6345	>	private static final int ABASE;
6346		private static final int ASHIFT;
6347
6348		static {
6349		try {
6054	–	U = sun.misc.Unsafe.getUnsafe();
6055	–	Class<?> k = ConcurrentHashMap.class;
6350		SIZECTL = U.objectFieldOffset
6351	<	(k.getDeclaredField("sizeCtl"));
6351	>	(ConcurrentHashMap.class.getDeclaredField("sizeCtl"));
6352		TRANSFERINDEX = U.objectFieldOffset
6353	<	(k.getDeclaredField("transferIndex"));
6060	<	TRANSFERORIGIN = U.objectFieldOffset
6061	<	(k.getDeclaredField("transferOrigin"));
6353	>	(ConcurrentHashMap.class.getDeclaredField("transferIndex"));
6354		BASECOUNT = U.objectFieldOffset
6355	<	(k.getDeclaredField("baseCount"));
6355	>	(ConcurrentHashMap.class.getDeclaredField("baseCount"));
6356		CELLSBUSY = U.objectFieldOffset
6357	<	(k.getDeclaredField("cellsBusy"));
6358	<	Class<?> ck = CounterCell.class;
6357	>	(ConcurrentHashMap.class.getDeclaredField("cellsBusy"));
6358	>
6359		CELLVALUE = U.objectFieldOffset
6360	<	(ck.getDeclaredField("value"));
6361	<	Class<?> ak = Node[].class;
6362	<	ABASE = U.arrayBaseOffset(ak);
6363	<	int scale = U.arrayIndexScale(ak);
6360	>	(CounterCell.class.getDeclaredField("value"));
6361	>
6362	>	ABASE = U.arrayBaseOffset(Node[].class);
6363	>	int scale = U.arrayIndexScale(Node[].class);
6364		if ((scale & (scale - 1)) != 0)
6365	<	throw new Error("data type scale not a power of two");
6365	>	throw new Error("array index scale not a power of two");
6366		ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
6367	<	} catch (Exception e) {
6368	<	throw new Error(e);
6367	>	} catch (ReflectiveOperationException e) {
6368	>	throw new ExceptionInInitializerError(e);
6369		}
6370	+
6371	+	// Reduce the risk of rare disastrous classloading in first call to
6372	+	// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
6373	+	Class<?> ensureLoaded = LockSupport.class;
6374		}
6375		}

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