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Comparing jsr166/src/jsr166e/ConcurrentHashMapV8.java (file contents):
Revision 1.8 by jsr166, Tue Aug 30 13:49:10 2011 UTC vs.
Revision 1.37 by dl, Sun Mar 4 20:34:27 2012 UTC

#	Line 6 | Line 6
6
7		package jsr166e;
8		import jsr166e.LongAdder;
9	+	import java.util.Arrays;
10		import java.util.Map;
11		import java.util.Set;
12		import java.util.Collection;
#	Line 19 | Line 20 | import java.util.Enumeration;
20		import java.util.ConcurrentModificationException;
21		import java.util.NoSuchElementException;
22		import java.util.concurrent.ConcurrentMap;
23	+	import java.util.concurrent.ThreadLocalRandom;
24	+	import java.util.concurrent.locks.LockSupport;
25		import java.io.Serializable;
26
27		/**
#	Line 49 | Line 52 | import java.io.Serializable;
52		* are typically useful only when a map is not undergoing concurrent
53		* updates in other threads.  Otherwise the results of these methods
54		* reflect transient states that may be adequate for monitoring
55	<	* purposes, but not for program control.
55	>	* or estimation purposes, but not for program control.
56		*
57	<	* <p> Resizing this or any other kind of hash table is a relatively
58	<	* slow operation, so, when possible, it is a good idea to provide
59	<	* estimates of expected table sizes in constructors. Also, for
60	<	* compatibility with previous versions of this class, constructors
61	<	* may optionally specify an expected {@code concurrencyLevel} as an
62	<	* additional hint for internal sizing.
57	>	* <p> The table is dynamically expanded when there are too many
58	>	* collisions (i.e., keys that have distinct hash codes but fall into
59	>	* the same slot modulo the table size), with the expected average
60	>	* effect of maintaining roughly two bins per mapping (corresponding
61	>	* to a 0.75 load factor threshold for resizing). There may be much
62	>	* variance around this average as mappings are added and removed, but
63	>	* overall, this maintains a commonly accepted time/space tradeoff for
64	>	* hash tables.  However, resizing this or any other kind of hash
65	>	* table may be a relatively slow operation. When possible, it is a
66	>	* good idea to provide a size estimate as an optional {@code
67	>	* initialCapacity} constructor argument. An additional optional
68	>	* {@code loadFactor} constructor argument provides a further means of
69	>	* customizing initial table capacity by specifying the table density
70	>	* to be used in calculating the amount of space to allocate for the
71	>	* given number of elements.  Also, for compatibility with previous
72	>	* versions of this class, constructors may optionally specify an
73	>	* expected {@code concurrencyLevel} as an additional hint for
74	>	* internal sizing.  Note that using many keys with exactly the same
75	>	* {@code hashCode()} is a sure way to slow down performance of any
76	>	* hash table.
77		*
78		* <p>This class and its views and iterators implement all of the
79		* <em>optional</em> methods of the {@link Map} and {@link Iterator}
#	Line 82 | Line 99 | public class ConcurrentHashMapV8<K, V>
99		private static final long serialVersionUID = 7249069246763182397L;
100
101		/**
102	<	* A function computing a mapping from the given key to a value,
103	<	* or {@code null} if there is no mapping. This is a place-holder
87	<	* for an upcoming JDK8 interface.
102	>	* A function computing a mapping from the given key to a value.
103	>	* This is a place-holder for an upcoming JDK8 interface.
104		*/
105		public static interface MappingFunction<K, V> {
106		/**
107	<	* Returns a value for the given key, or null if there is no
92	<	* mapping. If this function throws an (unchecked) exception,
93	<	* the exception is rethrown to its caller, and no mapping is
94	<	* recorded.  Because this function is invoked within
95	<	* atomicity control, the computation should be short and
96	<	* simple. The most common usage is to construct a new object
97	<	* serving as an initial mapped value.
107	>	* Returns a non-null value for the given key.
108		*
109		* @param key the (non-null) key
110	<	* @return a value, or null if none
110	>	* @return a non-null value
111		*/
112		V map(K key);
113		}
114
115	+	/**
116	+	* A function computing a new mapping given a key and its current
117	+	* mapped value (or {@code null} if there is no current
118	+	* mapping). This is a place-holder for an upcoming JDK8
119	+	* interface.
120	+	*/
121	+	public static interface RemappingFunction<K, V> {
122	+	/**
123	+	* Returns a new value given a key and its current value.
124	+	*
125	+	* @param key the (non-null) key
126	+	* @param value the current value, or null if there is no mapping
127	+	* @return a non-null value
128	+	*/
129	+	V remap(K key, V value);
130	+	}
131	+
132		/*
133		* Overview:
134		*
135		* The primary design goal of this hash table is to maintain
136		* concurrent readability (typically method get(), but also
137		* iterators and related methods) while minimizing update
138	<	* contention.
138	>	* contention. Secondary goals are to keep space consumption about
139	>	* the same or better than java.util.HashMap, and to support high
140	>	* initial insertion rates on an empty table by many threads.
141		*
142		* Each key-value mapping is held in a Node.  Because Node fields
143		* can contain special values, they are defined using plain Object
144		* types. Similarly in turn, all internal methods that use them
145	<	* work off Object types. All public generic-typed methods relay
146	<	* in/out of these internal methods, supplying casts as needed.
145	>	* work off Object types. And similarly, so do the internal
146	>	* methods of auxiliary iterator and view classes.  All public
147	>	* generic typed methods relay in/out of these internal methods,
148	>	* supplying null-checks and casts as needed. This also allows
149	>	* many of the public methods to be factored into a smaller number
150	>	* of internal methods (although sadly not so for the five
151	>	* sprawling variants of put-related operations).
152		*
153		* The table is lazily initialized to a power-of-two size upon the
154	<	* first insertion.  Each bin in the table contains a (typically
155	<	* short) list of Nodes.  Table accesses require volatile/atomic
156	<	* reads, writes, and CASes.  Because there is no other way to
157	<	* arrange this without adding further indirections, we use
158	<	* intrinsics (sun.misc.Unsafe) operations.  The lists of nodes
159	<	* within bins are always accurately traversable under volatile
160	<	* reads, so long as lookups check hash code and non-nullness of
161	<	* key and value before checking key equality. (All valid hash
162	<	* codes are nonnegative. Negative values are reserved for special
163	<	* forwarding nodes; see below.)
164	<	*
165	<	* A bin may be locked during update (insert, delete, and replace)
166	<	* operations.  We do not want to waste the space required to
167	<	* associate a distinct lock object with each bin, so instead use
168	<	* the first node of a bin list itself as a lock, using builtin
169	<	* "synchronized" locks. These save space and we can live with
170	<	* only plain block-structured lock/unlock operations. Using the
171	<	* first node of a list as a lock does not by itself suffice
172	<	* though: When a node is locked, any update must first validate
173	<	* that it is still the first node, and retry if not. (Because new
174	<	* nodes are always appended to lists, once a node is first in a
175	<	* bin, it remains first until deleted or the bin becomes
176	<	* invalidated.)  However, update operations can and usually do
177	<	* still traverse the bin until the point of update, which helps
178	<	* reduce cache misses on retries.  This is a converse of sorts to
179	<	* the lazy locking technique described by Herlihy & Shavit. If
180	<	* there is no existing node during a put operation, then one can
181	<	* be CAS'ed in (without need for lock except in computeIfAbsent);
182	<	* the CAS serves as validation. This is on average the most
183	<	* common case for put operations -- under random hash codes, the
184	<	* distribution of nodes in bins follows a Poisson distribution
185	<	* (see http://en.wikipedia.org/wiki/Poisson_distribution) with a
186	<	* parameter of 0.5 on average under the default loadFactor of
187	<	* 0.75.  The expected number of locks covering different elements
188	<	* (i.e., bins with 2 or more nodes) is approximately 10% at
189	<	* steady state under default settings.  Lock contention
190	<	* probability for two threads accessing arbitrary distinct
191	<	* elements is, roughly, 1 / (8 * #elements).
192	<	*
193	<	* The table is resized when occupancy exceeds a threshold.  Only
194	<	* a single thread performs the resize (using field "resizing", to
195	<	* arrange exclusion), but the table otherwise remains usable for
196	<	* both reads and updates. Resizing proceeds by transferring bins,
197	<	* one by one, from the table to the next table.  Upon transfer,
198	<	* the old table bin contains only a special forwarding node (with
199	<	* negative hash code ("MOVED")) that contains the next table as
154	>	* first insertion.  Each bin in the table contains a list of
155	>	* Nodes (most often, the list has only zero or one Node).  Table
156	>	* accesses require volatile/atomic reads, writes, and CASes.
157	>	* Because there is no other way to arrange this without adding
158	>	* further indirections, we use intrinsics (sun.misc.Unsafe)
159	>	* operations.  The lists of nodes within bins are always
160	>	* accurately traversable under volatile reads, so long as lookups
161	>	* check hash code and non-nullness of value before checking key
162	>	* equality.
163	>	*
164	>	* We use the top two bits of Node hash fields for control
165	>	* purposes -- they are available anyway because of addressing
166	>	* constraints.  As explained further below, these top bits are
167	>	* used as follows:
168	>	*  00 - Normal
169	>	*  01 - Locked
170	>	*  11 - Locked and may have a thread waiting for lock
171	>	*  10 - Node is a forwarding node
172	>	*
173	>	* The lower 30 bits of each Node's hash field contain a
174	>	* transformation (for better randomization -- method "spread") of
175	>	* the key's hash code, except for forwarding nodes, for which the
176	>	* lower bits are zero (and so always have hash field == MOVED).
177	>	*
178	>	* Insertion (via put or its variants) of the first node in an
179	>	* empty bin is performed by just CASing it to the bin.  This is
180	>	* by far the most common case for put operations.  Other update
181	>	* operations (insert, delete, and replace) require locks.  We do
182	>	* not want to waste the space required to associate a distinct
183	>	* lock object with each bin, so instead use the first node of a
184	>	* bin list itself as a lock. Blocking support for these locks
185	>	* relies on the builtin "synchronized" monitors.  However, we
186	>	* also need a tryLock construction, so we overlay these by using
187	>	* bits of the Node hash field for lock control (see above), and
188	>	* so normally use builtin monitors only for blocking and
189	>	* signalling using wait/notifyAll constructions. See
190	>	* Node.tryAwaitLock.
191	>	*
192	>	* Using the first node of a list as a lock does not by itself
193	>	* suffice though: When a node is locked, any update must first
194	>	* validate that it is still the first node after locking it, and
195	>	* retry if not. Because new nodes are always appended to lists,
196	>	* once a node is first in a bin, it remains first until deleted
197	>	* or the bin becomes invalidated (upon resizing).  However,
198	>	* operations that only conditionally update may inspect nodes
199	>	* until the point of update. This is a converse of sorts to the
200	>	* lazy locking technique described by Herlihy & Shavit.
201	>	*
202	>	* The main disadvantage of per-bin locks is that other update
203	>	* operations on other nodes in a bin list protected by the same
204	>	* lock can stall, for example when user equals() or mapping
205	>	* functions take a long time.  However, statistically, this is
206	>	* not a common enough problem to outweigh the time/space overhead
207	>	* of alternatives: Under random hash codes, the frequency of
208	>	* nodes in bins follows a Poisson distribution
209	>	* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
210	>	* parameter of about 0.5 on average, given the resizing threshold
211	>	* of 0.75, although with a large variance because of resizing
212	>	* granularity. Ignoring variance, the expected occurrences of
213	>	* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
214	>	* first few values are:
215	>	*
216	>	* 0:    0.607
217	>	* 1:    0.303
218	>	* 2:    0.076
219	>	* 3:    0.012
220	>	* more: 0.002
221	>	*
222	>	* Lock contention probability for two threads accessing distinct
223	>	* elements is roughly 1 / (8 * #elements).  Function "spread"
224	>	* performs hashCode randomization that improves the likelihood
225	>	* that these assumptions hold unless users define exactly the
226	>	* same value for too many hashCodes.
227	>	*
228	>	* The table is resized when occupancy exceeds an occupancy
229	>	* threshold (nominally, 0.75, but see below).  Only a single
230	>	* thread performs the resize (using field "sizeCtl", to arrange
231	>	* exclusion), but the table otherwise remains usable for reads
232	>	* and updates. Resizing proceeds by transferring bins, one by
233	>	* one, from the table to the next table.  Because we are using
234	>	* power-of-two expansion, the elements from each bin must either
235	>	* stay at same index, or move with a power of two offset. We
236	>	* eliminate unnecessary node creation by catching cases where old
237	>	* nodes can be reused because their next fields won't change.  On
238	>	* average, only about one-sixth of them need cloning when a table
239	>	* doubles. The nodes they replace will be garbage collectable as
240	>	* soon as they are no longer referenced by any reader thread that
241	>	* may be in the midst of concurrently traversing table.  Upon
242	>	* transfer, the old table bin contains only a special forwarding
243	>	* node (with hash field "MOVED") that contains the next table as
244		* its key. On encountering a forwarding node, access and update
245	<	* operations restart, using the new table. To ensure concurrent
246	<	* readability of traversals, transfers must proceed from the last
247	<	* bin (table.length - 1) up towards the first.  Any traversal
248	<	* starting from the first bin can then arrange to move to the new
249	<	* table for the rest of the traversal without revisiting nodes.
250	<	* This constrains bin transfers to a particular order, and so can
251	<	* block indefinitely waiting for the next lock, and other threads
252	<	* cannot help with the transfer. However, expected stalls are
253	<	* infrequent enough to not warrant the additional overhead and
254	<	* complexity of access and iteration schemes that could admit
255	<	* out-of-order or concurrent bin transfers.
256	<	*
257	<	* A similar traversal scheme (not yet implemented) can apply to
258	<	* partial traversals during partitioned aggregate operations.
259	<	* Also, read-only operations give up if ever forwarded to a null
260	<	* table, which provides support for shutdown-style clearing,
261	<	* which is also not currently implemented.
245	>	* operations restart, using the new table.
246	>	*
247	>	* Each bin transfer requires its bin lock. However, unlike other
248	>	* cases, a transfer can skip a bin if it fails to acquire its
249	>	* lock, and revisit it later. Method rebuild maintains a buffer
250	>	* of TRANSFER_BUFFER_SIZE bins that have been skipped because of
251	>	* failure to acquire a lock, and blocks only if none are
252	>	* available (i.e., only very rarely).  The transfer operation
253	>	* must also ensure that all accessible bins in both the old and
254	>	* new table are usable by any traversal.  When there are no lock
255	>	* acquisition failures, this is arranged simply by proceeding
256	>	* from the last bin (table.length - 1) up towards the first.
257	>	* Upon seeing a forwarding node, traversals (see class
258	>	* InternalIterator) arrange to move to the new table without
259	>	* revisiting nodes.  However, when any node is skipped during a
260	>	* transfer, all earlier table bins may have become visible, so
261	>	* are initialized with a reverse-forwarding node back to the old
262	>	* table until the new ones are established. (This sometimes
263	>	* requires transiently locking a forwarding node, which is
264	>	* possible under the above encoding.) These more expensive
265	>	* mechanics trigger only when necessary.
266	>	*
267	>	* The traversal scheme also applies to partial traversals of
268	>	* ranges of bins (via an alternate InternalIterator constructor)
269	>	* to support partitioned aggregate operations (that are not
270	>	* otherwise implemented yet).  Also, read-only operations give up
271	>	* if ever forwarded to a null table, which provides support for
272	>	* shutdown-style clearing, which is also not currently
273	>	* implemented.
274	>	*
275	>	* Lazy table initialization minimizes footprint until first use,
276	>	* and also avoids resizings when the first operation is from a
277	>	* putAll, constructor with map argument, or deserialization.
278	>	* These cases attempt to override the initial capacity settings,
279	>	* but harmlessly fail to take effect in cases of races.
280		*
281		* The element count is maintained using a LongAdder, which avoids
282		* contention on updates but can encounter cache thrashing if read
283	<	* too frequently during concurrent updates. To avoid reading so
284	<	* often, resizing is normally attempted only upon adding to a bin
285	<	* already holding two or more nodes. Under the default threshold
286	<	* (0.75), and uniform hash distributions, the probability of this
287	<	* occurring at threshold is around 13%, meaning that only about 1
288	<	* in 8 puts check threshold (and after resizing, many fewer do
289	<	* so). But this approximation has high variance for small table
290	<	* sizes, so we check on any collision for sizes <= 64.  Further,
291	<	* to increase the probability that a resize occurs soon enough, we
292	<	* offset the threshold (see THRESHOLD_OFFSET) by the expected
293	<	* number of puts between checks. This is currently set to 8, in
294	<	* accord with the default load factor. In practice, this is
295	<	* rarely overridden, and in any case is close enough to other
296	<	* plausible values not to waste dynamic probability computation
297	<	* for more precision.
283	>	* too frequently during concurrent access. To avoid reading so
284	>	* often, resizing is attempted either when a bin lock is
285	>	* contended, or upon adding to a bin already holding two or more
286	>	* nodes (checked before adding in the xIfAbsent methods, after
287	>	* adding in others). Under uniform hash distributions, the
288	>	* probability of this occurring at threshold is around 13%,
289	>	* meaning that only about 1 in 8 puts check threshold (and after
290	>	* resizing, many fewer do so). But this approximation has high
291	>	* variance for small table sizes, so we check on any collision
292	>	* for sizes <= 64. The bulk putAll operation further reduces
293	>	* contention by only committing count updates upon these size
294	>	* checks.
295	>	*
296	>	* Maintaining API and serialization compatibility with previous
297	>	* versions of this class introduces several oddities. Mainly: We
298	>	* leave untouched but unused constructor arguments refering to
299	>	* concurrencyLevel. We accept a loadFactor constructor argument,
300	>	* but apply it only to initial table capacity (which is the only
301	>	* time that we can guarantee to honor it.) We also declare an
302	>	* unused "Segment" class that is instantiated in minimal form
303	>	* only when serializing.
304		*/
305
306		/* ---------------- Constants -------------- */
307
308		/**
309	<	* The smallest allowed table capacity.  Must be a power of 2, at
310	<	* least 2.
309	>	* The largest possible table capacity.  This value must be
310	>	* exactly 1<<30 to stay within Java array allocation and indexing
311	>	* bounds for power of two table sizes, and is further required
312	>	* because the top two bits of 32bit hash fields are used for
313	>	* control purposes.
314		*/
315	<	static final int MINIMUM_CAPACITY = 2;
315	>	private static final int MAXIMUM_CAPACITY = 1 << 30;
316
317		/**
318	<	* The largest allowed table capacity.  Must be a power of 2, at
319	<	* most 1<<30.
318	>	* The default initial table capacity.  Must be a power of 2
319	>	* (i.e., at least 1) and at most MAXIMUM_CAPACITY.
320		*/
321	<	static final int MAXIMUM_CAPACITY = 1 << 30;
321	>	private static final int DEFAULT_CAPACITY = 16;
322
323		/**
324	<	* The default initial table capacity.  Must be a power of 2, at
325	<	* least MINIMUM_CAPACITY and at most MAXIMUM_CAPACITY
324	>	* The largest possible (non-power of two) array size.
325	>	* Needed by toArray and related methods.
326		*/
327	<	static final int DEFAULT_CAPACITY = 16;
327	>	static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
328
329		/**
330	<	* The default load factor for this table, used when not otherwise
331	<	* specified in a constructor.
330	>	* The default concurrency level for this table. Unused but
331	>	* defined for compatibility with previous versions of this class.
332		*/
333	<	static final float DEFAULT_LOAD_FACTOR = 0.75f;
333	>	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
334
335		/**
336	<	* The default concurrency level for this table. Unused, but
337	<	* defined for compatibility with previous versions of this class.
336	>	* The load factor for this table. Overrides of this value in
337	>	* constructors affect only the initial table capacity.  The
338	>	* actual floating point value isn't normally used -- it is
339	>	* simpler to use expressions such as {@code n - (n >>> 2)} for
340	>	* the associated resizing threshold.
341		*/
342	<	static final int DEFAULT_CONCURRENCY_LEVEL = 16;
342	>	private static final float LOAD_FACTOR = 0.75f;
343
344		/**
345	<	* The count value to offset thresholds to compensate for checking
346	<	* for resizing only when inserting into bins with two or more
347	<	* elements. See above for explanation.
345	>	* The buffer size for skipped bins during transfers. The
346	>	* value is arbitrary but should be large enough to avoid
347	>	* most locking stalls during resizes.
348		*/
349	<	static final int THRESHOLD_OFFSET = 8;
349	>	private static final int TRANSFER_BUFFER_SIZE = 32;
350
351	<	/**
352	<	* Special node hash value indicating to use table in node.key
353	<	* Must be negative.
351	>	/*
352	>	* Encodings for special uses of Node hash fields. See above for
353	>	* explanation.
354		*/
355	<	static final int MOVED = -1;
355	>	static final int MOVED     = 0x80000000; // hash field for forwarding nodes
356	>	static final int LOCKED    = 0x40000000; // set/tested only as a bit
357	>	static final int WAITING   = 0xc0000000; // both bits set/tested together
358	>	static final int HASH_BITS = 0x3fffffff; // usable bits of normal node hash
359
360		/* ---------------- Fields -------------- */
361
362		/**
363		* The array of bins. Lazily initialized upon first insertion.
364	<	* Size is always a power of two. Accessed directly by inner
254	<	* classes.
364	>	* Size is always a power of two. Accessed directly by iterators.
365		*/
366		transient volatile Node[] table;
367
368	<	/** The counter maintaining number of elements. */
368	>	/**
369	>	* The counter maintaining number of elements.
370	>	*/
371		private transient final LongAdder counter;
372	<	/** Nonzero when table is being initialized or resized. Updated via CAS. */
373	<	private transient volatile int resizing;
374	<	/** The target load factor for the table. */
375	<	private transient float loadFactor;
376	<	/** The next element count value upon which to resize the table. */
377	<	private transient int threshold;
378	<	/** The initial capacity of the table. */
379	<	private transient int initCap;
372	>
373	>	/**
374	>	* Table initialization and resizing control.  When negative, the
375	>	* table is being initialized or resized. Otherwise, when table is
376	>	* null, holds the initial table size to use upon creation, or 0
377	>	* for default. After initialization, holds the next element count
378	>	* value upon which to resize the table.
379	>	*/
380	>	private transient volatile int sizeCtl;
381
382		// views
383	<	transient Set<K> keySet;
384	<	transient Set<Map.Entry<K,V>> entrySet;
385	<	transient Collection<V> values;
383	>	private transient KeySet<K,V> keySet;
384	>	private transient Values<K,V> values;
385	>	private transient EntrySet<K,V> entrySet;
386
387		/** For serialization compatibility. Null unless serialized; see below */
388	<	Segment<K,V>[] segments;
388	>	private Segment<K,V>[] segments;
389
390	<	/**
278	<	* Applies a supplemental hash function to a given hashCode, which
279	<	* defends against poor quality hash functions.  The result must
280	<	* be non-negative, and for reasonable performance must have good
281	<	* avalanche properties; i.e., that each bit of the argument
282	<	* affects each bit (except sign bit) of the result.
283	<	*/
284	<	private static final int spread(int h) {
285	<	// Apply base step of MurmurHash; see http://code.google.com/p/smhasher/
286	<	h ^= h >>> 16;
287	<	h *= 0x85ebca6b;
288	<	h ^= h >>> 13;
289	<	h *= 0xc2b2ae35;
290	<	return (h >>> 16) ^ (h & 0x7fffffff); // mask out sign bit
291	<	}
390	>	/* ---------------- Nodes -------------- */
391
392		/**
393		* Key-value entry. Note that this is never exported out as a
394	<	* user-visible Map.Entry.
394	>	* user-visible Map.Entry (see WriteThroughEntry and SnapshotEntry
395	>	* below). Nodes with a hash field of MOVED are special, and do
396	>	* not contain user keys or values.  Otherwise, keys are never
397	>	* null, and null val fields indicate that a node is in the
398	>	* process of being deleted or created. For purposes of read-only
399	>	* access, a key may be read before a val, but can only be used
400	>	* after checking val to be non-null.
401		*/
402		static final class Node {
403	<	final int hash;
403	>	volatile int hash;
404		final Object key;
405		volatile Object val;
406		volatile Node next;
#	Line 306 | Line 411 | public class ConcurrentHashMapV8<K, V>
411		this.val = val;
412		this.next = next;
413		}
414	+
415	+	/** CompareAndSet the hash field */
416	+	final boolean casHash(int cmp, int val) {
417	+	return UNSAFE.compareAndSwapInt(this, hashOffset, cmp, val);
418	+	}
419	+
420	+	/** The number of spins before blocking for a lock */
421	+	static final int MAX_SPINS =
422	+	Runtime.getRuntime().availableProcessors() > 1 ? 64 : 1;
423	+
424	+	/**
425	+	* Spins a while if LOCKED bit set and this node is the first
426	+	* of its bin, and then sets WAITING bits on hash field and
427	+	* blocks (once) if they are still set.  It is OK for this
428	+	* method to return even if lock is not available upon exit,
429	+	* which enables these simple single-wait mechanics.
430	+	*
431	+	* The corresponding signalling operation is performed within
432	+	* callers: Upon detecting that WAITING has been set when
433	+	* unlocking lock (via a failed CAS from non-waiting LOCKED
434	+	* state), unlockers acquire the sync lock and perform a
435	+	* notifyAll.
436	+	*/
437	+	final void tryAwaitLock(Node[] tab, int i) {
438	+	if (tab != null && i >= 0 && i < tab.length) { // bounds check
439	+	int r = ThreadLocalRandom.current().nextInt(); // randomize spins
440	+	int spins = MAX_SPINS, h;
441	+	while (tabAt(tab, i) == this && ((h = hash) & LOCKED) != 0) {
442	+	if (spins >= 0) {
443	+	r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
444	+	if (r >= 0 && --spins == 0)
445	+	Thread.yield();  // yield before block
446	+	}
447	+	else if (casHash(h, h | WAITING)) {
448	+	synchronized (this) {
449	+	if (tabAt(tab, i) == this &&
450	+	(hash & WAITING) == WAITING) {
451	+	try {
452	+	wait();
453	+	} catch (InterruptedException ie) {
454	+	Thread.currentThread().interrupt();
455	+	}
456	+	}
457	+	else
458	+	notifyAll(); // possibly won race vs signaller
459	+	}
460	+	break;
461	+	}
462	+	}
463	+	}
464	+	}
465	+
466	+	// Unsafe mechanics for casHash
467	+	private static final sun.misc.Unsafe UNSAFE;
468	+	private static final long hashOffset;
469	+
470	+	static {
471	+	try {
472	+	UNSAFE = getUnsafe();
473	+	Class<?> k = Node.class;
474	+	hashOffset = UNSAFE.objectFieldOffset
475	+	(k.getDeclaredField("hash"));
476	+	} catch (Exception e) {
477	+	throw new Error(e);
478	+	}
479	+	}
480		}
481
482	+	/* ---------------- Table element access -------------- */
483	+
484		/*
485		* Volatile access methods are used for table elements as well as
486	<	* elements of in-progress next table while resizing.  Uses in
487	<	* access and update methods are null checked by callers, and
488	<	* implicitly bounds-checked, relying on the invariants that tab
489	<	* arrays have non-zero size, and all indices are masked with
490	<	* (tab.length - 1) which is never negative and always less than
491	<	* length. The "relaxed" non-volatile forms are used only during
492	<	* table initialization. The only other usage is in
493	<	* HashIterator.advance, which performs explicit checks.
486	>	* elements of in-progress next table while resizing.  Uses are
487	>	* null checked by callers, and implicitly bounds-checked, relying
488	>	* on the invariants that tab arrays have non-zero size, and all
489	>	* indices are masked with (tab.length - 1) which is never
490	>	* negative and always less than length. Note that, to be correct
491	>	* wrt arbitrary concurrency errors by users, bounds checks must
492	>	* operate on local variables, which accounts for some odd-looking
493	>	* inline assignments below.
494		*/
495
496	<	static final Node tabAt(Node[] tab, int i) { // used in HashIterator
496	>	static final Node tabAt(Node[] tab, int i) { // used by InternalIterator
497		return (Node)UNSAFE.getObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE);
498		}
499
#	Line 332 | Line 505 | public class ConcurrentHashMapV8<K, V>
505		UNSAFE.putObjectVolatile(tab, ((long)i<<ASHIFT)+ABASE, v);
506		}
507
508	<	private static final Node relaxedTabAt(Node[] tab, int i) {
336	<	return (Node)UNSAFE.getObject(tab, ((long)i<<ASHIFT)+ABASE);
337	<	}
508	>	/* ---------------- Internal access and update methods -------------- */
509
510	<	private static final void relaxedSetTabAt(Node[] tab, int i, Node v) {
511	<	UNSAFE.putObject(tab, ((long)i<<ASHIFT)+ABASE, v);
510	>	/**
511	>	* Applies a supplemental hash function to a given hashCode, which
512	>	* defends against poor quality hash functions.  The result must
513	>	* be have the top 2 bits clear. For reasonable performance, this
514	>	* function must have good avalanche properties; i.e., that each
515	>	* bit of the argument affects each bit of the result. (Although
516	>	* we don't care about the unused top 2 bits.)
517	>	*/
518	>	private static final int spread(int h) {
519	>	// Apply base step of MurmurHash; see http://code.google.com/p/smhasher/
520	>	// Despite two multiplies, this is often faster than others
521	>	// with comparable bit-spread properties.
522	>	h ^= h >>> 16;
523	>	h *= 0x85ebca6b;
524	>	h ^= h >>> 13;
525	>	h *= 0xc2b2ae35;
526	>	return ((h >>> 16) ^ h) & HASH_BITS; // mask out top bits
527		}
528
529	<	/* ---------------- Access and update operations -------------- */
344	<
345	<	/** Implementation for get and containsKey **/
529	>	/** Implementation for get and containsKey */
530		private final Object internalGet(Object k) {
531		int h = spread(k.hashCode());
532	<	Node[] tab = table;
533	<	retry: while (tab != null) {
534	<	Node e = tabAt(tab, (tab.length - 1) & h);
535	<	while (e != null) {
536	<	int eh = e.hash;
353	<	if (eh == h) {
354	<	Object ek = e.key, ev = e.val;
355	<	if (ev != null && ek != null && (k == ek || k.equals(ek)))
356	<	return ev;
357	<	}
358	<	else if (eh < 0) { // bin was moved during resize
359	<	tab = (Node[])e.key;
532	>	retry: for (Node[] tab = table; tab != null;) {
533	>	Node e; Object ek, ev; int eh;    // locals to read fields once
534	>	for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) {
535	>	if ((eh = e.hash) == MOVED) {
536	>	tab = (Node[])e.key;      // restart with new table
537		continue retry;
538		}
539	<	e = e.next;
539	>	if ((eh & HASH_BITS) == h && (ev = e.val) != null &&
540	>	((ek = e.key) == k || k.equals(ek)))
541	>	return ev;
542		}
543		break;
544		}
545		return null;
546		}
547
548	<	/** Implementation for put and putIfAbsent **/
549	<	private final Object internalPut(Object k, Object v, boolean replace) {
548	>	/**
549	>	* Implementation for the four public remove/replace methods:
550	>	* Replaces node value with v, conditional upon match of cv if
551	>	* non-null.  If resulting value is null, delete.
552	>	*/
553	>	private final Object internalReplace(Object k, Object v, Object cv) {
554		int h = spread(k.hashCode());
555	<	Object oldVal = null;  // the previous value or null if none
556	<	Node[] tab = table;
557	<	for (;;) {
558	<	Node e; int i;
555	>	Object oldVal = null;
556	>	for (Node[] tab = table;;) {
557	>	Node f; int i, fh;
558	>	if (tab == null ||
559	>	(f = tabAt(tab, i = (tab.length - 1) & h)) == null)
560	>	break;
561	>	else if ((fh = f.hash) == MOVED)
562	>	tab = (Node[])f.key;
563	>	else if ((fh & HASH_BITS) != h && f.next == null) // precheck
564	>	break;                          // rules out possible existence
565	>	else if ((fh & LOCKED) != 0) {
566	>	checkForResize();               // try resizing if can't get lock
567	>	f.tryAwaitLock(tab, i);
568	>	}
569	>	else if (f.casHash(fh, fh | LOCKED)) {
570	>	boolean validated = false;
571	>	boolean deleted = false;
572	>	try {
573	>	if (tabAt(tab, i) == f) {
574	>	validated = true;
575	>	for (Node e = f, pred = null;;) {
576	>	Object ek, ev;
577	>	if ((e.hash & HASH_BITS) == h &&
578	>	((ev = e.val) != null) &&
579	>	((ek = e.key) == k || k.equals(ek))) {
580	>	if (cv == null || cv == ev || cv.equals(ev)) {
581	>	oldVal = ev;
582	>	if ((e.val = v) == null) {
583	>	deleted = true;
584	>	Node en = e.next;
585	>	if (pred != null)
586	>	pred.next = en;
587	>	else
588	>	setTabAt(tab, i, en);
589	>	}
590	>	}
591	>	break;
592	>	}
593	>	pred = e;
594	>	if ((e = e.next) == null)
595	>	break;
596	>	}
597	>	}
598	>	} finally {
599	>	if (!f.casHash(fh | LOCKED, fh)) {
600	>	f.hash = fh;
601	>	synchronized (f) { f.notifyAll(); };
602	>	}
603	>	}
604	>	if (validated) {
605	>	if (deleted)
606	>	counter.add(-1L);
607	>	break;
608	>	}
609	>	}
610	>	}
611	>	return oldVal;
612	>	}
613	>
614	>	/*
615	>	* Internal versions of the five insertion methods, each a
616	>	* little more complicated than the last. All have
617	>	* the same basic structure as the first (internalPut):
618	>	*  1. If table uninitialized, create
619	>	*  2. If bin empty, try to CAS new node
620	>	*  3. If bin stale, use new table
621	>	*  4. Lock and validate; if valid, scan and add or update
622	>	*
623	>	* The others interweave other checks and/or alternative actions:
624	>	*  * Plain put checks for and performs resize after insertion.
625	>	*  * putIfAbsent prescans for mapping without lock (and fails to add
626	>	*    if present), which also makes pre-emptive resize checks worthwhile.
627	>	*  * computeIfAbsent extends form used in putIfAbsent with additional
628	>	*    mechanics to deal with, calls, potential exceptions and null
629	>	*    returns from function call.
630	>	*  * compute uses the same function-call mechanics, but without
631	>	*    the prescans
632	>	*  * putAll attempts to pre-allocate enough table space
633	>	*    and more lazily performs count updates and checks.
634	>	*
635	>	* Someday when details settle down a bit more, it might be worth
636	>	* some factoring to reduce sprawl.
637	>	*/
638	>
639	>	/** Implementation for put */
640	>	private final Object internalPut(Object k, Object v) {
641	>	int h = spread(k.hashCode());
642	>	boolean checkSize = false;
643	>	for (Node[] tab = table;;) {
644	>	int i; Node f; int fh;
645		if (tab == null)
646	<	tab = grow(0);
647	<	else if ((e = tabAt(tab, i = (tab.length - 1) & h)) == null) {
646	>	tab = initTable();
647	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
648		if (casTabAt(tab, i, null, new Node(h, k, v, null)))
649	<	break;
649	>	break;                   // no lock when adding to empty bin
650		}
651	<	else if (e.hash < 0)
652	<	tab = (Node[])e.key;
653	<	else {
651	>	else if ((fh = f.hash) == MOVED)
652	>	tab = (Node[])f.key;
653	>	else if ((fh & LOCKED) != 0) {
654	>	checkForResize();
655	>	f.tryAwaitLock(tab, i);
656	>	}
657	>	else if (f.casHash(fh, fh | LOCKED)) {
658	>	Object oldVal = null;
659		boolean validated = false;
660	<	boolean checkSize = false;
661	<	synchronized (e) {
662	<	Node first = e;
663	<	for (;;) {
664	<	Object ek, ev;
665	<	if ((ev = e.val) == null)
666	<	break;
667	<	if (e.hash == h && (ek = e.key) != null &&
394	<	(k == ek || k.equals(ek))) {
395	<	if (tabAt(tab, i) == first) {
396	<	validated = true;
660	>	try {                        // needed in case equals() throws
661	>	if (tabAt(tab, i) == f) {
662	>	validated = true;    // retry if 1st already deleted
663	>	for (Node e = f;;) {
664	>	Object ek, ev;
665	>	if ((e.hash & HASH_BITS) == h &&
666	>	(ev = e.val) != null &&
667	>	((ek = e.key) == k || k.equals(ek))) {
668		oldVal = ev;
669	<	if (replace)
670	<	e.val = v;
669	>	e.val = v;
670	>	break;
671		}
672	<	break;
673	<	}
403	<	Node last = e;
404	<	if ((e = e.next) == null) {
405	<	if (tabAt(tab, i) == first) {
406	<	validated = true;
672	>	Node last = e;
673	>	if ((e = e.next) == null) {
674		last.next = new Node(h, k, v, null);
675	<	if (last != first || tab.length <= 64)
675	>	if (last != f || tab.length <= 64)
676		checkSize = true;
677	+	break;
678		}
411	–	break;
679		}
680		}
681	+	} finally {                  // unlock and signal if needed
682	+	if (!f.casHash(fh | LOCKED, fh)) {
683	+	f.hash = fh;
684	+	synchronized (f) { f.notifyAll(); };
685	+	}
686		}
687		if (validated) {
688	<	if (checkSize && tab.length < MAXIMUM_CAPACITY &&
689	<	resizing == 0 && counter.sum() >= threshold)
418	<	grow(0);
688	>	if (oldVal != null)
689	>	return oldVal;
690		break;
691		}
692		}
693		}
694	<	if (oldVal == null)
695	<	counter.increment();
696	<	return oldVal;
694	>	counter.add(1L);
695	>	if (checkSize)
696	>	checkForResize();
697	>	return null;
698		}
699
700	<	/**
701	<	* Covers the four public remove/replace methods: Replaces node
430	<	* value with v, conditional upon match of cv if non-null.  If
431	<	* resulting value is null, delete.
432	<	*/
433	<	private final Object internalReplace(Object k, Object v, Object cv) {
700	>	/** Implementation for putIfAbsent */
701	>	private final Object internalPutIfAbsent(Object k, Object v) {
702		int h = spread(k.hashCode());
703	<	Object oldVal = null;
704	<	Node e; int i;
705	<	Node[] tab = table;
706	<	while (tab != null &&
707	<	(e = tabAt(tab, i = (tab.length - 1) & h)) != null) {
708	<	if (e.hash < 0)
709	<	tab = (Node[])e.key;
703	>	for (Node[] tab = table;;) {
704	>	int i; Node f; int fh; Object fk, fv;
705	>	if (tab == null)
706	>	tab = initTable();
707	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
708	>	if (casTabAt(tab, i, null, new Node(h, k, v, null)))
709	>	break;
710	>	}
711	>	else if ((fh = f.hash) == MOVED)
712	>	tab = (Node[])f.key;
713	>	else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
714	>	((fk = f.key) == k || k.equals(fk)))
715	>	return fv;
716		else {
717	<	boolean validated = false;
718	<	boolean deleted = false;
719	<	synchronized (e) {
446	<	Node pred = null;
447	<	Node first = e;
448	<	for (;;) {
717	>	Node g = f.next;
718	>	if (g != null) { // at least 2 nodes -- search and maybe resize
719	>	for (Node e = g;;) {
720		Object ek, ev;
721	<	if ((ev = e.val) == null)
721	>	if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
722	>	((ek = e.key) == k || k.equals(ek)))
723	>	return ev;
724	>	if ((e = e.next) == null) {
725	>	checkForResize();
726		break;
727	<	if (e.hash == h && (ek = e.key) != null &&
728	<	(k == ek || k.equals(ek))) {
729	<	if (tabAt(tab, i) == first) {
730	<	validated = true;
731	<	if (cv == null || cv == ev || cv.equals(ev)) {
727	>	}
728	>	}
729	>	}
730	>	if (((fh = f.hash) & LOCKED) != 0) {
731	>	checkForResize();
732	>	f.tryAwaitLock(tab, i);
733	>	}
734	>	else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
735	>	Object oldVal = null;
736	>	boolean validated = false;
737	>	try {
738	>	if (tabAt(tab, i) == f) {
739	>	validated = true;
740	>	for (Node e = f;;) {
741	>	Object ek, ev;
742	>	if ((e.hash & HASH_BITS) == h &&
743	>	(ev = e.val) != null &&
744	>	((ek = e.key) == k || k.equals(ek))) {
745		oldVal = ev;
746	<	if ((e.val = v) == null) {
747	<	deleted = true;
748	<	Node en = e.next;
749	<	if (pred != null)
750	<	pred.next = en;
751	<	else
464	<	setTabAt(tab, i, en);
465	<	}
746	>	break;
747	>	}
748	>	Node last = e;
749	>	if ((e = e.next) == null) {
750	>	last.next = new Node(h, k, v, null);
751	>	break;
752		}
753		}
468	–	break;
754		}
755	<	pred = e;
755	>	} finally {
756	>	if (!f.casHash(fh | LOCKED, fh)) {
757	>	f.hash = fh;
758	>	synchronized (f) { f.notifyAll(); };
759	>	}
760	>	}
761	>	if (validated) {
762	>	if (oldVal != null)
763	>	return oldVal;
764	>	break;
765	>	}
766	>	}
767	>	}
768	>	}
769	>	counter.add(1L);
770	>	return null;
771	>	}
772	>
773	>	/** Implementation for computeIfAbsent */
774	>	private final Object internalComputeIfAbsent(K k,
775	>	MappingFunction<? super K, ?> mf) {
776	>	int h = spread(k.hashCode());
777	>	Object val = null;
778	>	for (Node[] tab = table;;) {
779	>	Node f; int i, fh; Object fk, fv;
780	>	if (tab == null)
781	>	tab = initTable();
782	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
783	>	Node node = new Node(fh = h | LOCKED, k, null, null);
784	>	boolean validated = false;
785	>	if (casTabAt(tab, i, null, node)) {
786	>	validated = true;
787	>	try {
788	>	if ((val = mf.map(k)) != null)
789	>	node.val = val;
790	>	} finally {
791	>	if (val == null)
792	>	setTabAt(tab, i, null);
793	>	if (!node.casHash(fh, h)) {
794	>	node.hash = h;
795	>	synchronized (node) { node.notifyAll(); };
796	>	}
797	>	}
798	>	}
799	>	if (validated)
800	>	break;
801	>	}
802	>	else if ((fh = f.hash) == MOVED)
803	>	tab = (Node[])f.key;
804	>	else if ((fh & HASH_BITS) == h && (fv = f.val) != null &&
805	>	((fk = f.key) == k || k.equals(fk)))
806	>	return fv;
807	>	else {
808	>	Node g = f.next;
809	>	if (g != null) {
810	>	for (Node e = g;;) {
811	>	Object ek, ev;
812	>	if ((e.hash & HASH_BITS) == h && (ev = e.val) != null &&
813	>	((ek = e.key) == k || k.equals(ek)))
814	>	return ev;
815		if ((e = e.next) == null) {
816	<	if (tabAt(tab, i) == first)
473	<	validated = true;
816	>	checkForResize();
817		break;
818		}
819		}
820		}
821	<	if (validated) {
822	<	if (deleted)
823	<	counter.decrement();
824	<	break;
821	>	if (((fh = f.hash) & LOCKED) != 0) {
822	>	checkForResize();
823	>	f.tryAwaitLock(tab, i);
824	>	}
825	>	else if (tabAt(tab, i) == f && f.casHash(fh, fh | LOCKED)) {
826	>	boolean validated = false;
827	>	try {
828	>	if (tabAt(tab, i) == f) {
829	>	validated = true;
830	>	for (Node e = f;;) {
831	>	Object ek, ev;
832	>	if ((e.hash & HASH_BITS) == h &&
833	>	(ev = e.val) != null &&
834	>	((ek = e.key) == k || k.equals(ek))) {
835	>	val = ev;
836	>	break;
837	>	}
838	>	Node last = e;
839	>	if ((e = e.next) == null) {
840	>	if ((val = mf.map(k)) != null)
841	>	last.next = new Node(h, k, val, null);
842	>	break;
843	>	}
844	>	}
845	>	}
846	>	} finally {
847	>	if (!f.casHash(fh | LOCKED, fh)) {
848	>	f.hash = fh;
849	>	synchronized (f) { f.notifyAll(); };
850	>	}
851	>	}
852	>	if (validated)
853	>	break;
854		}
855		}
856		}
857	<	return oldVal;
857	>	if (val == null)
858	>	throw new NullPointerException();
859	>	counter.add(1L);
860	>	return val;
861		}
862
863	<	/** Implementation for computeIfAbsent and compute */
863	>	/** Implementation for compute */
864		@SuppressWarnings("unchecked")
865	<	private final V internalCompute(K k,
866	<	MappingFunction<? super K, ? extends V> f,
492	<	boolean replace) {
865	>	private final Object internalCompute(K k,
866	>	RemappingFunction<? super K, V> mf) {
867		int h = spread(k.hashCode());
868	<	V val = null;
868	>	Object val = null;
869		boolean added = false;
870	<	boolean validated = false;
871	<	Node[] tab = table;
872	<	do {
499	<	Node e; int i;
870	>	boolean checkSize = false;
871	>	for (Node[] tab = table;;) {
872	>	Node f; int i, fh;
873		if (tab == null)
874	<	tab = grow(0);
875	<	else if ((e = tabAt(tab, i = (tab.length - 1) & h)) == null) {
876	<	Node node = new Node(h, k, null, null);
877	<	synchronized (node) {
878	<	if (casTabAt(tab, i, null, node)) {
879	<	validated = true;
880	<	try {
881	<	val = f.map(k);
882	<	if (val != null) {
883	<	node.val = val;
884	<	added = true;
885	<	}
886	<	} finally {
887	<	if (!added)
888	<	setTabAt(tab, i, null);
874	>	tab = initTable();
875	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) {
876	>	Node node = new Node(fh = h | LOCKED, k, null, null);
877	>	boolean validated = false;
878	>	if (casTabAt(tab, i, null, node)) {
879	>	validated = true;
880	>	try {
881	>	if ((val = mf.remap(k, null)) != null) {
882	>	node.val = val;
883	>	added = true;
884	>	}
885	>	} finally {
886	>	if (!added)
887	>	setTabAt(tab, i, null);
888	>	if (!node.casHash(fh, h)) {
889	>	node.hash = h;
890	>	synchronized (node) { node.notifyAll(); };
891		}
892		}
893		}
894	+	if (validated)
895	+	break;
896		}
897	<	else if (e.hash < 0)
898	<	tab = (Node[])e.key;
899	<	else if (Thread.holdsLock(e))
900	<	throw new IllegalStateException("Recursive map computation");
901	<	else {
902	<	boolean checkSize = false;
903	<	synchronized (e) {
904	<	Node first = e;
905	<	for (;;) {
906	<	Object ek, ev;
907	<	if ((ev = e.val) == null)
908	<	break;
909	<	if (e.hash == h && (ek = e.key) != null &&
910	<	(k == ek || k.equals(ek))) {
911	<	if (tabAt(tab, i) == first) {
912	<	validated = true;
913	<	if (replace && (ev = f.map(k)) != null)
914	<	e.val = ev;
915	<	val = (V)ev;
897	>	else if ((fh = f.hash) == MOVED)
898	>	tab = (Node[])f.key;
899	>	else if ((fh & LOCKED) != 0) {
900	>	checkForResize();
901	>	f.tryAwaitLock(tab, i);
902	>	}
903	>	else if (f.casHash(fh, fh | LOCKED)) {
904	>	boolean validated = false;
905	>	try {
906	>	if (tabAt(tab, i) == f) {
907	>	validated = true;
908	>	for (Node e = f;;) {
909	>	Object ek, ev;
910	>	if ((e.hash & HASH_BITS) == h &&
911	>	(ev = e.val) != null &&
912	>	((ek = e.key) == k || k.equals(ek))) {
913	>	val = mf.remap(k, (V)ev);
914	>	if (val != null)
915	>	e.val = val;
916	>	break;
917		}
918	<	break;
919	<	}
920	<	Node last = e;
543	<	if ((e = e.next) == null) {
544	<	if (tabAt(tab, i) == first) {
545	<	validated = true;
546	<	if ((val = f.map(k)) != null) {
918	>	Node last = e;
919	>	if ((e = e.next) == null) {
920	>	if ((val = mf.remap(k, null)) != null) {
921		last.next = new Node(h, k, val, null);
922		added = true;
923	<	if (last != first || tab.length <= 64)
923	>	if (last != f || tab.length <= 64)
924		checkSize = true;
925		}
926	+	break;
927		}
553	–	break;
928		}
929		}
930	+	} finally {
931	+	if (!f.casHash(fh | LOCKED, fh)) {
932	+	f.hash = fh;
933	+	synchronized (f) { f.notifyAll(); };
934	+	}
935		}
936	<	if (checkSize && tab.length < MAXIMUM_CAPACITY &&
937	<	resizing == 0 && counter.sum() >= threshold)
938	<	grow(0);
939	<	}
940	<	} while (!validated);
941	<	if (added)
942	<	counter.increment();
936	>	if (validated)
937	>	break;
938	>	}
939	>	}
940	>	if (val == null)
941	>	throw new NullPointerException();
942	>	if (added) {
943	>	counter.add(1L);
944	>	if (checkSize)
945	>	checkForResize();
946	>	}
947		return val;
948		}
949
950	<	/*
951	<	* Reclassifies nodes in each bin to new table.  Because we are
952	<	* using power-of-two expansion, the elements from each bin must
953	<	* either stay at same index, or move with a power of two
954	<	* offset. We eliminate unnecessary node creation by catching
955	<	* cases where old nodes can be reused because their next fields
956	<	* won't change.  Statistically, at the default threshold, only
957	<	* about one-sixth of them need cloning when a table doubles. The
958	<	* nodes they replace will be garbage collectable as soon as they
959	<	* are no longer referenced by any reader thread that may be in
960	<	* the midst of concurrently traversing table.
961	<	*
579	<	* Transfers are done from the bottom up to preserve iterator
580	<	* traversability. On each step, the old bin is locked,
581	<	* moved/copied, and then replaced with a forwarding node.
582	<	*/
583	<	private static final void transfer(Node[] tab, Node[] nextTab) {
584	<	int n = tab.length;
585	<	int mask = nextTab.length - 1;
586	<	Node fwd = new Node(MOVED, nextTab, null, null);
587	<	for (int i = n - 1; i >= 0; --i) {
588	<	for (Node e;;) {
589	<	if ((e = tabAt(tab, i)) == null) {
590	<	if (casTabAt(tab, i, e, fwd))
591	<	break;
950	>	/** Implementation for putAll */
951	>	private final void internalPutAll(Map<?, ?> m) {
952	>	tryPresize(m.size());
953	>	long delta = 0L;     // number of uncommitted additions
954	>	boolean npe = false; // to throw exception on exit for nulls
955	>	try {                // to clean up counts on other exceptions
956	>	for (Map.Entry<?, ?> entry : m.entrySet()) {
957	>	Object k, v;
958	>	if (entry == null || (k = entry.getKey()) == null ||
959	>	(v = entry.getValue()) == null) {
960	>	npe = true;
961	>	break;
962		}
963	<	else {
964	<	boolean validated = false;
965	<	synchronized (e) {
966	<	int idx = e.hash & mask;
967	<	Node lastRun = e;
968	<	for (Node p = e.next; p != null; p = p.next) {
969	<	int j = p.hash & mask;
970	<	if (j != idx) {
971	<	idx = j;
972	<	lastRun = p;
963	>	int h = spread(k.hashCode());
964	>	for (Node[] tab = table;;) {
965	>	int i; Node f; int fh;
966	>	if (tab == null)
967	>	tab = initTable();
968	>	else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){
969	>	if (casTabAt(tab, i, null, new Node(h, k, v, null))) {
970	>	++delta;
971	>	break;
972	>	}
973	>	}
974	>	else if ((fh = f.hash) == MOVED)
975	>	tab = (Node[])f.key;
976	>	else if ((fh & LOCKED) != 0) {
977	>	counter.add(delta);
978	>	delta = 0L;
979	>	checkForResize();
980	>	f.tryAwaitLock(tab, i);
981	>	}
982	>	else if (f.casHash(fh, fh | LOCKED)) {
983	>	boolean validated = false;
984	>	boolean tooLong = false;
985	>	try {
986	>	if (tabAt(tab, i) == f) {
987	>	validated = true;
988	>	for (Node e = f;;) {
989	>	Object ek, ev;
990	>	if ((e.hash & HASH_BITS) == h &&
991	>	(ev = e.val) != null &&
992	>	((ek = e.key) == k || k.equals(ek))) {
993	>	e.val = v;
994	>	break;
995	>	}
996	>	Node last = e;
997	>	if ((e = e.next) == null) {
998	>	++delta;
999	>	last.next = new Node(h, k, v, null);
1000	>	break;
1001	>	}
1002	>	tooLong = true;
1003	>	}
1004	>	}
1005	>	} finally {
1006	>	if (!f.casHash(fh | LOCKED, fh)) {
1007	>	f.hash = fh;
1008	>	synchronized (f) { f.notifyAll(); };
1009		}
1010		}
1011	<	if (tabAt(tab, i) == e) {
1012	<	validated = true;
1013	<	relaxedSetTabAt(nextTab, idx, lastRun);
1014	<	for (Node p = e; p != lastRun; p = p.next) {
1015	<	int h = p.hash;
610	<	int j = h & mask;
611	<	Node r = relaxedTabAt(nextTab, j);
612	<	relaxedSetTabAt(nextTab, j,
613	<	new Node(h, p.key, p.val, r));
1011	>	if (validated) {
1012	>	if (tooLong) {
1013	>	counter.add(delta);
1014	>	delta = 0L;
1015	>	checkForResize();
1016		}
1017	<	setTabAt(tab, i, fwd);
1017	>	break;
1018		}
1019		}
618	–	if (validated)
619	–	break;
1020		}
1021		}
1022	+	} finally {
1023	+	if (delta != 0)
1024	+	counter.add(delta);
1025		}
1026	+	if (npe)
1027	+	throw new NullPointerException();
1028		}
1029
1030	+	/* ---------------- Table Initialization and Resizing -------------- */
1031	+
1032		/**
1033	<	* If not already resizing, initializes or creates next table and
1034	<	* transfers bins. Rechecks occupancy after a transfer to see if
1035	<	* another resize is already needed because resizings are lagging
1036	<	* additions.
1037	<	*
1038	<	* @param sizeHint overridden capacity target (nonzero only from putAll)
1039	<	* @return current table
1040	<	*/
1041	<	private final Node[] grow(int sizeHint) {
1042	<	if (resizing == 0 &&
1043	<	UNSAFE.compareAndSwapInt(this, resizingOffset, 0, 1)) {
1044	<	try {
1045	<	for (;;) {
1046	<	int cap, n;
1047	<	Node[] tab = table;
1048	<	if (tab == null) {
1049	<	int c = initCap;
1050	<	if (c < sizeHint)
1051	<	c = sizeHint;
1052	<	if (c == DEFAULT_CAPACITY)
1053	<	cap = c;
1054	<	else if (c >= MAXIMUM_CAPACITY)
1055	<	cap = MAXIMUM_CAPACITY;
1056	<	else {
1057	<	cap = MINIMUM_CAPACITY;
1058	<	while (cap < c)
1059	<	cap <<= 1;
1060	<	}
1061	<	}
1062	<	else if ((n = tab.length) < MAXIMUM_CAPACITY &&
656	<	(sizeHint <= 0 || n < sizeHint))
657	<	cap = n << 1;
658	<	else
659	<	break;
660	<	threshold = (int)(cap * loadFactor) - THRESHOLD_OFFSET;
661	<	Node[] nextTab = new Node[cap];
662	<	if (tab != null)
663	<	transfer(tab, nextTab);
664	<	table = nextTab;
665	<	if (tab == null || cap >= MAXIMUM_CAPACITY ||
666	<	(sizeHint > 0 && cap >= sizeHint) ||
667	<	counter.sum() < threshold)
668	<	break;
1033	>	* Returns a power of two table size for the given desired capacity.
1034	>	* See Hackers Delight, sec 3.2
1035	>	*/
1036	>	private static final int tableSizeFor(int c) {
1037	>	int n = c - 1;
1038	>	n |= n >>> 1;
1039	>	n |= n >>> 2;
1040	>	n |= n >>> 4;
1041	>	n |= n >>> 8;
1042	>	n |= n >>> 16;
1043	>	return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
1044	>	}
1045	>
1046	>	/**
1047	>	* Initializes table, using the size recorded in sizeCtl.
1048	>	*/
1049	>	private final Node[] initTable() {
1050	>	Node[] tab; int sc;
1051	>	while ((tab = table) == null) {
1052	>	if ((sc = sizeCtl) < 0)
1053	>	Thread.yield(); // lost initialization race; just spin
1054	>	else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
1055	>	try {
1056	>	if ((tab = table) == null) {
1057	>	int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
1058	>	tab = table = new Node[n];
1059	>	sc = n - (n >>> 2);
1060	>	}
1061	>	} finally {
1062	>	sizeCtl = sc;
1063		}
1064	<	} finally {
671	<	resizing = 0;
1064	>	break;
1065		}
1066		}
1067	<	else if (table == null)
675	<	Thread.yield(); // lost initialization race; just spin
676	<	return table;
1067	>	return tab;
1068		}
1069
1070		/**
1071	<	* Implementation for putAll and constructor with Map
1072	<	* argument. Tries to first override initial capacity or grow
1073	<	* based on map size to pre-allocate table space.
1071	>	* If table is too small and not already resizing, creates next
1072	>	* table and transfers bins.  Rechecks occupancy after a transfer
1073	>	* to see if another resize is already needed because resizings
1074	>	* are lagging additions.
1075		*/
1076	<	private final void internalPutAll(Map<? extends K, ? extends V> m) {
1077	<	int s = m.size();
1078	<	grow((s >= (MAXIMUM_CAPACITY >>> 1)) ? s : s + (s >>> 1));
1079	<	for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) {
1080	<	Object k = e.getKey();
1081	<	Object v = e.getValue();
1082	<	if (k == null || v == null)
1083	<	throw new NullPointerException();
1084	<	internalPut(k, v, true);
1076	>	private final void checkForResize() {
1077	>	Node[] tab; int n, sc;
1078	>	while ((tab = table) != null &&
1079	>	(n = tab.length) < MAXIMUM_CAPACITY &&
1080	>	(sc = sizeCtl) >= 0 && counter.sum() >= (long)sc &&
1081	>	UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
1082	>	try {
1083	>	if (tab == table) {
1084	>	table = rebuild(tab);
1085	>	sc = (n << 1) - (n >>> 1);
1086	>	}
1087	>	} finally {
1088	>	sizeCtl = sc;
1089	>	}
1090		}
1091		}
1092
1093		/**
1094	<	* Implementation for clear. Steps through each bin, removing all nodes.
1094	>	* Tries to presize table to accommodate the given number of elements.
1095	>	*
1096	>	* @param size number of elements (doesn't need to be perfectly accurate)
1097		*/
1098	<	private final void internalClear() {
1099	<	long deletions = 0L;
1100	<	int i = 0;
1101	<	Node[] tab = table;
1102	<	while (tab != null && i < tab.length) {
1103	<	Node e = tabAt(tab, i);
1104	<	if (e == null)
1105	<	++i;
1106	<	else if (e.hash < 0)
1107	<	tab = (Node[])e.key;
1108	<	else {
1109	<	boolean validated = false;
1110	<	synchronized (e) {
1111	<	if (tabAt(tab, i) == e) {
1112	<	validated = true;
1113	<	do {
715	<	if (e.val != null) {
716	<	e.val = null;
717	<	++deletions;
718	<	}
719	<	} while ((e = e.next) != null);
720	<	setTabAt(tab, i, null);
1098	>	private final void tryPresize(int size) {
1099	>	int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
1100	>	tableSizeFor(size + (size >>> 1) + 1);
1101	>	int sc;
1102	>	while ((sc = sizeCtl) >= 0) {
1103	>	Node[] tab = table; int n;
1104	>	if (tab == null || (n = tab.length) == 0) {
1105	>	n = (sc > c) ? sc : c;
1106	>	if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
1107	>	try {
1108	>	if (table == tab) {
1109	>	table = new Node[n];
1110	>	sc = n - (n >>> 2);
1111	>	}
1112	>	} finally {
1113	>	sizeCtl = sc;
1114		}
1115		}
1116	<	if (validated) {
1117	<	++i;
1118	<	if (deletions > THRESHOLD_OFFSET) { // bound lag in counts
1119	<	counter.add(-deletions);
1120	<	deletions = 0L;
1116	>	}
1117	>	else if (c <= sc || n >= MAXIMUM_CAPACITY)
1118	>	break;
1119	>	else if (UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
1120	>	try {
1121	>	if (table == tab) {
1122	>	table = rebuild(tab);
1123	>	sc = (n << 1) - (n >>> 1);
1124		}
1125	+	} finally {
1126	+	sizeCtl = sc;
1127		}
1128		}
1129		}
732	–	if (deletions != 0L)
733	–	counter.add(-deletions);
1130		}
1131
1132	<	/**
1133	<	* Base class for key, value, and entry iterators, plus internal
1134	<	* implementations of public traversal-based methods, to avoid
1135	<	* duplicating traversal code.
1132	>	/*
1133	>	* Moves and/or copies the nodes in each bin to new table. See
1134	>	* above for explanation.
1135	>	*
1136	>	* @return the new table
1137		*/
1138	<	class HashIterator {
1139	<	private Node next;          // the next entry to return
1140	<	private Node[] tab;         // current table; updated if resized
1141	<	private Node lastReturned;  // the last entry returned, for remove
1142	<	private Object nextVal;     // cached value of next
1143	<	private int index;          // index of bin to use next
1144	<	private int baseIndex;      // current index of initial table
1145	<	private final int baseSize; // initial table size
1146	<
1147	<	HashIterator() {
1148	<	Node[] t = tab = table;
1149	<	if (t == null)
1150	<	baseSize = 0;
1151	<	else {
1152	<	baseSize = t.length;
1153	<	advance(null);
1154	<	}
1155	<	}
1156	<
1157	<	public final boolean hasNext()         { return next != null; }
1158	<	public final boolean hasMoreElements() { return next != null; }
1159	<
1160	<	/**
1161	<	* Advances next.  Normally, iteration proceeds bin-by-bin
1162	<	* traversing lists.  However, if the table has been resized,
1163	<	* then all future steps must traverse both the bin at the
1164	<	* current index as well as at (index + baseSize); and so on
768	<	* for further resizings. To paranoically cope with potential
769	<	* (improper) sharing of iterators across threads, table reads
770	<	* are bounds-checked.
771	<	*/
772	<	final void advance(Node e) {
773	<	for (;;) {
774	<	Node[] t; int i; // for bounds checks
775	<	if (e != null) {
776	<	Object ek = e.key, ev = e.val;
777	<	if (ev != null && ek != null) {
778	<	nextVal = ev;
779	<	next = e;
780	<	break;
1138	>	private static final Node[] rebuild(Node[] tab) {
1139	>	int n = tab.length;
1140	>	Node[] nextTab = new Node[n << 1];
1141	>	Node fwd = new Node(MOVED, nextTab, null, null);
1142	>	int[] buffer = null;       // holds bins to revisit; null until needed
1143	>	Node rev = null;           // reverse forwarder; null until needed
1144	>	int nbuffered = 0;         // the number of bins in buffer list
1145	>	int bufferIndex = 0;       // buffer index of current buffered bin
1146	>	int bin = n - 1;           // current non-buffered bin or -1 if none
1147	>
1148	>	for (int i = bin;;) {      // start upwards sweep
1149	>	int fh; Node f;
1150	>	if ((f = tabAt(tab, i)) == null) {
1151	>	if (bin >= 0) {    // no lock needed (or available)
1152	>	if (!casTabAt(tab, i, f, fwd))
1153	>	continue;
1154	>	}
1155	>	else {             // transiently use a locked forwarding node
1156	>	Node g = new Node(MOVED|LOCKED, nextTab, null, null);
1157	>	if (!casTabAt(tab, i, f, g))
1158	>	continue;
1159	>	setTabAt(nextTab, i, null);
1160	>	setTabAt(nextTab, i + n, null);
1161	>	setTabAt(tab, i, fwd);
1162	>	if (!g.casHash(MOVED|LOCKED, MOVED)) {
1163	>	g.hash = MOVED;
1164	>	synchronized (g) { g.notifyAll(); }
1165		}
782	–	e = e.next;
1166		}
1167	<	else if (baseIndex < baseSize && (t = tab) != null &&
1168	<	t.length > (i = index) && i >= 0) {
1169	<	if ((e = tabAt(t, i)) != null && e.hash < 0) {
1170	<	tab = (Node[])e.key;
1171	<	e = null;
1167	>	}
1168	>	else if (((fh = f.hash) & LOCKED) == 0 && f.casHash(fh, fh|LOCKED)) {
1169	>	boolean validated = false;
1170	>	try {              // split to lo and hi lists; copying as needed
1171	>	if (tabAt(tab, i) == f) {
1172	>	validated = true;
1173	>	Node e = f, lastRun = f;
1174	>	Node lo = null, hi = null;
1175	>	int runBit = e.hash & n;
1176	>	for (Node p = e.next; p != null; p = p.next) {
1177	>	int b = p.hash & n;
1178	>	if (b != runBit) {
1179	>	runBit = b;
1180	>	lastRun = p;
1181	>	}
1182	>	}
1183	>	if (runBit == 0)
1184	>	lo = lastRun;
1185	>	else
1186	>	hi = lastRun;
1187	>	for (Node p = e; p != lastRun; p = p.next) {
1188	>	int ph = p.hash & HASH_BITS;
1189	>	Object pk = p.key, pv = p.val;
1190	>	if ((ph & n) == 0)
1191	>	lo = new Node(ph, pk, pv, lo);
1192	>	else
1193	>	hi = new Node(ph, pk, pv, hi);
1194	>	}
1195	>	setTabAt(nextTab, i, lo);
1196	>	setTabAt(nextTab, i + n, hi);
1197	>	setTabAt(tab, i, fwd);
1198	>	}
1199	>	} finally {
1200	>	if (!f.casHash(fh | LOCKED, fh)) {
1201	>	f.hash = fh;
1202	>	synchronized (f) { f.notifyAll(); };
1203		}
790	–	else if (i + baseSize < t.length)
791	–	index += baseSize;    // visit forwarded upper slots
792	–	else
793	–	index = ++baseIndex;
1204		}
1205	<	else {
1206	<	next = null;
1207	<	break;
1205	>	if (!validated)
1206	>	continue;
1207	>	}
1208	>	else {
1209	>	if (buffer == null) // initialize buffer for revisits
1210	>	buffer = new int[TRANSFER_BUFFER_SIZE];
1211	>	if (bin < 0 && bufferIndex > 0) {
1212	>	int j = buffer[--bufferIndex];
1213	>	buffer[bufferIndex] = i;
1214	>	i = j;         // swap with another bin
1215	>	continue;
1216		}
1217	+	if (bin < 0 || nbuffered >= TRANSFER_BUFFER_SIZE) {
1218	+	f.tryAwaitLock(tab, i);
1219	+	continue;      // no other options -- block
1220	+	}
1221	+	if (rev == null)   // initialize reverse-forwarder
1222	+	rev = new Node(MOVED, tab, null, null);
1223	+	if (tabAt(tab, i) != f || (f.hash & LOCKED) == 0)
1224	+	continue;      // recheck before adding to list
1225	+	buffer[nbuffered++] = i;
1226	+	setTabAt(nextTab, i, rev);     // install place-holders
1227	+	setTabAt(nextTab, i + n, rev);
1228		}
800	–	}
801	–
802	–	final Object nextKey() {
803	–	Node e = next;
804	–	if (e == null)
805	–	throw new NoSuchElementException();
806	–	Object k = e.key;
807	–	advance((lastReturned = e).next);
808	–	return k;
809	–	}
810	–
811	–	final Object nextValue() {
812	–	Node e = next;
813	–	if (e == null)
814	–	throw new NoSuchElementException();
815	–	Object v = nextVal;
816	–	advance((lastReturned = e).next);
817	–	return v;
818	–	}
819	–
820	–	final WriteThroughEntry nextEntry() {
821	–	Node e = next;
822	–	if (e == null)
823	–	throw new NoSuchElementException();
824	–	WriteThroughEntry entry =
825	–	new WriteThroughEntry(e.key, nextVal);
826	–	advance((lastReturned = e).next);
827	–	return entry;
828	–	}
1229
1230	<	public final void remove() {
1231	<	if (lastReturned == null)
1232	<	throw new IllegalStateException();
1233	<	ConcurrentHashMapV8.this.remove(lastReturned.key);
1234	<	lastReturned = null;
835	<	}
836	<
837	<	/** Helper for serialization */
838	<	final void writeEntries(java.io.ObjectOutputStream s)
839	<	throws java.io.IOException {
840	<	Node e;
841	<	while ((e = next) != null) {
842	<	s.writeObject(e.key);
843	<	s.writeObject(nextVal);
844	<	advance(e.next);
1230	>	if (bin > 0)
1231	>	i = --bin;
1232	>	else if (buffer != null && nbuffered > 0) {
1233	>	bin = -1;
1234	>	i = buffer[bufferIndex = --nbuffered];
1235		}
1236	+	else
1237	+	return nextTab;
1238		}
1239	+	}
1240
1241	<	/** Helper for containsValue */
1242	<	final boolean containsVal(Object value) {
1243	<	if (value != null) {
1244	<	Node e;
1245	<	while ((e = next) != null) {
1246	<	Object v = nextVal;
1247	<	if (value == v || value.equals(v))
1248	<	return true;
1249	<	advance(e.next);
1241	>	/**
1242	>	* Implementation for clear. Steps through each bin, removing all
1243	>	* nodes.
1244	>	*/
1245	>	private final void internalClear() {
1246	>	long delta = 0L; // negative number of deletions
1247	>	int i = 0;
1248	>	Node[] tab = table;
1249	>	while (tab != null && i < tab.length) {
1250	>	int fh;
1251	>	Node f = tabAt(tab, i);
1252	>	if (f == null)
1253	>	++i;
1254	>	else if ((fh = f.hash) == MOVED)
1255	>	tab = (Node[])f.key;
1256	>	else if ((fh & LOCKED) != 0) {
1257	>	counter.add(delta); // opportunistically update count
1258	>	delta = 0L;
1259	>	f.tryAwaitLock(tab, i);
1260	>	}
1261	>	else if (f.casHash(fh, fh | LOCKED)) {
1262	>	boolean validated = false;
1263	>	try {
1264	>	if (tabAt(tab, i) == f) {
1265	>	validated = true;
1266	>	for (Node e = f; e != null; e = e.next) {
1267	>	if (e.val != null) { // currently always true
1268	>	e.val = null;
1269	>	--delta;
1270	>	}
1271	>	}
1272	>	setTabAt(tab, i, null);
1273	>	}
1274	>	} finally {
1275	>	if (!f.casHash(fh | LOCKED, fh)) {
1276	>	f.hash = fh;
1277	>	synchronized (f) { f.notifyAll(); };
1278	>	}
1279		}
1280	+	if (validated)
1281	+	++i;
1282		}
859	–	return false;
1283		}
1284	+	if (delta != 0)
1285	+	counter.add(delta);
1286	+	}
1287
862	–	/** Helper for Map.hashCode */
863	–	final int mapHashCode() {
864	–	int h = 0;
865	–	Node e;
866	–	while ((e = next) != null) {
867	–	h += e.key.hashCode() ^ nextVal.hashCode();
868	–	advance(e.next);
869	–	}
870	–	return h;
871	–	}
1288
1289	<	/** Helper for Map.toString */
1290	<	final String mapToString() {
1291	<	Node e = next;
1292	<	if (e == null)
1293	<	return "{}";
1294	<	StringBuilder sb = new StringBuilder();
1295	<	sb.append('{');
1296	<	for (;;) {
1297	<	sb.append(e.key   == this ? "(this Map)" : e.key);
1298	<	sb.append('=');
1299	<	sb.append(nextVal == this ? "(this Map)" : nextVal);
1300	<	advance(e.next);
1301	<	if ((e = next) != null)
1302	<	sb.append(',').append(' ');
1303	<	else
1304	<	return sb.append('}').toString();
1305	<	}
1289	>	/* ----------------Table Traversal -------------- */
1290	>
1291	>	/**
1292	>	* Encapsulates traversal for methods such as containsValue; also
1293	>	* serves as a base class for other iterators.
1294	>	*
1295	>	* At each step, the iterator snapshots the key ("nextKey") and
1296	>	* value ("nextVal") of a valid node (i.e., one that, at point of
1297	>	* snapshot, has a non-null user value). Because val fields can
1298	>	* change (including to null, indicating deletion), field nextVal
1299	>	* might not be accurate at point of use, but still maintains the
1300	>	* weak consistency property of holding a value that was once
1301	>	* valid.
1302	>	*
1303	>	* Internal traversals directly access these fields, as in:
1304	>	* {@code while (it.next != null) { process(it.nextKey); it.advance(); }}
1305	>	*
1306	>	* Exported iterators (subclasses of ViewIterator) extract key,
1307	>	* value, or key-value pairs as return values of Iterator.next(),
1308	>	* and encapsulate the it.next check as hasNext();
1309	>	*
1310	>	* The iterator visits once each still-valid node that was
1311	>	* reachable upon iterator construction. It might miss some that
1312	>	* were added to a bin after the bin was visited, which is OK wrt
1313	>	* consistency guarantees. Maintaining this property in the face
1314	>	* of possible ongoing resizes requires a fair amount of
1315	>	* bookkeeping state that is difficult to optimize away amidst
1316	>	* volatile accesses.  Even so, traversal maintains reasonable
1317	>	* throughput.
1318	>	*
1319	>	* Normally, iteration proceeds bin-by-bin traversing lists.
1320	>	* However, if the table has been resized, then all future steps
1321	>	* must traverse both the bin at the current index as well as at
1322	>	* (index + baseSize); and so on for further resizings. To
1323	>	* paranoically cope with potential sharing by users of iterators
1324	>	* across threads, iteration terminates if a bounds checks fails
1325	>	* for a table read.
1326	>	*
1327	>	* The range-based constructor enables creation of parallel
1328	>	* range-splitting traversals. (Not yet implemented.)
1329	>	*/
1330	>	static class InternalIterator {
1331	>	Node next;           // the next entry to use
1332	>	Node last;           // the last entry used
1333	>	Object nextKey;      // cached key field of next
1334	>	Object nextVal;      // cached val field of next
1335	>	Node[] tab;          // current table; updated if resized
1336	>	int index;           // index of bin to use next
1337	>	int baseIndex;       // current index of initial table
1338	>	final int baseLimit; // index bound for initial table
1339	>	final int baseSize;  // initial table size
1340	>
1341	>	/** Creates iterator for all entries in the table. */
1342	>	InternalIterator(Node[] tab) {
1343	>	this.tab = tab;
1344	>	baseLimit = baseSize = (tab == null) ? 0 : tab.length;
1345	>	index = baseIndex = 0;
1346	>	next = null;
1347	>	advance();
1348	>	}
1349	>
1350	>	/** Creates iterator for the given range of the table */
1351	>	InternalIterator(Node[] tab, int lo, int hi) {
1352	>	this.tab = tab;
1353	>	baseSize = (tab == null) ? 0 : tab.length;
1354	>	baseLimit = (hi <= baseSize) ? hi : baseSize;
1355	>	index = baseIndex = (lo >= 0) ? lo : 0;
1356	>	next = null;
1357	>	advance();
1358	>	}
1359	>
1360	>	/** Advances next. See above for explanation. */
1361	>	final void advance() {
1362	>	Node e = last = next;
1363	>	outer: do {
1364	>	if (e != null)                  // advance past used/skipped node
1365	>	e = e.next;
1366	>	while (e == null) {             // get to next non-null bin
1367	>	Node[] t; int b, i, n;      // checks must use locals
1368	>	if ((b = baseIndex) >= baseLimit || (i = index) < 0 ||
1369	>	(t = tab) == null || i >= (n = t.length))
1370	>	break outer;
1371	>	else if ((e = tabAt(t, i)) != null && e.hash == MOVED)
1372	>	tab = (Node[])e.key;    // restarts due to null val
1373	>	else                        // visit upper slots if present
1374	>	index = (i += baseSize) < n ? i : (baseIndex = b + 1);
1375	>	}
1376	>	nextKey = e.key;
1377	>	} while ((nextVal = e.val) == null);// skip deleted or special nodes
1378	>	next = e;
1379		}
1380		}
1381
1382		/* ---------------- Public operations -------------- */
1383
1384		/**
1385	<	* Creates a new, empty map with the specified initial
897	<	* capacity, load factor and concurrency level.
898	<	*
899	<	* @param initialCapacity the initial capacity. The implementation
900	<	* performs internal sizing to accommodate this many elements.
901	<	* @param loadFactor  the load factor threshold, used to control resizing.
902	<	* Resizing may be performed when the average number of elements per
903	<	* bin exceeds this threshold.
904	<	* @param concurrencyLevel the estimated number of concurrently
905	<	* updating threads. The implementation may use this value as
906	<	* a sizing hint.
907	<	* @throws IllegalArgumentException if the initial capacity is
908	<	* negative or the load factor or concurrencyLevel are
909	<	* nonpositive.
1385	>	* Creates a new, empty map with the default initial table size (16),
1386		*/
1387	<	public ConcurrentHashMapV8(int initialCapacity,
912	<	float loadFactor, int concurrencyLevel) {
913	<	if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
914	<	throw new IllegalArgumentException();
915	<	this.initCap = initialCapacity;
916	<	this.loadFactor = loadFactor;
1387	>	public ConcurrentHashMapV8() {
1388		this.counter = new LongAdder();
1389		}
1390
1391		/**
1392	<	* Creates a new, empty map with the specified initial capacity
1393	<	* and load factor and with the default concurrencyLevel (16).
1392	>	* Creates a new, empty map with an initial table size
1393	>	* accommodating the specified number of elements without the need
1394	>	* to dynamically resize.
1395		*
1396		* @param initialCapacity The implementation performs internal
1397		* sizing to accommodate this many elements.
926	–	* @param loadFactor  the load factor threshold, used to control resizing.
927	–	* Resizing may be performed when the average number of elements per
928	–	* bin exceeds this threshold.
1398		* @throws IllegalArgumentException if the initial capacity of
1399	<	* elements is negative or the load factor is nonpositive
931	<	*
932	<	* @since 1.6
1399	>	* elements is negative
1400		*/
1401	<	public ConcurrentHashMapV8(int initialCapacity, float loadFactor) {
1402	<	this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
1401	>	public ConcurrentHashMapV8(int initialCapacity) {
1402	>	if (initialCapacity < 0)
1403	>	throw new IllegalArgumentException();
1404	>	int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
1405	>	MAXIMUM_CAPACITY :
1406	>	tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
1407	>	this.counter = new LongAdder();
1408	>	this.sizeCtl = cap;
1409		}
1410
1411		/**
1412	<	* Creates a new, empty map with the specified initial capacity,
940	<	* and with default load factor (0.75) and concurrencyLevel (16).
1412	>	* Creates a new map with the same mappings as the given map.
1413		*
1414	<	* @param initialCapacity the initial capacity. The implementation
943	<	* performs internal sizing to accommodate this many elements.
944	<	* @throws IllegalArgumentException if the initial capacity of
945	<	* elements is negative.
1414	>	* @param m the map
1415		*/
1416	<	public ConcurrentHashMapV8(int initialCapacity) {
1417	<	this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1416	>	public ConcurrentHashMapV8(Map<? extends K, ? extends V> m) {
1417	>	this.counter = new LongAdder();
1418	>	this.sizeCtl = DEFAULT_CAPACITY;
1419	>	internalPutAll(m);
1420		}
1421
1422		/**
1423	<	* Creates a new, empty map with a default initial capacity (16),
1424	<	* load factor (0.75) and concurrencyLevel (16).
1423	>	* Creates a new, empty map with an initial table size based on
1424	>	* the given number of elements ({@code initialCapacity}) and
1425	>	* initial table density ({@code loadFactor}).
1426	>	*
1427	>	* @param initialCapacity the initial capacity. The implementation
1428	>	* performs internal sizing to accommodate this many elements,
1429	>	* given the specified load factor.
1430	>	* @param loadFactor the load factor (table density) for
1431	>	* establishing the initial table size
1432	>	* @throws IllegalArgumentException if the initial capacity of
1433	>	* elements is negative or the load factor is nonpositive
1434	>	*
1435	>	* @since 1.6
1436		*/
1437	<	public ConcurrentHashMapV8() {
1438	<	this(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1437	>	public ConcurrentHashMapV8(int initialCapacity, float loadFactor) {
1438	>	this(initialCapacity, loadFactor, 1);
1439		}
1440
1441		/**
1442	<	* Creates a new map with the same mappings as the given map.
1443	<	* The map is created with a capacity of 1.5 times the number
1444	<	* of mappings in the given map or 16 (whichever is greater),
1445	<	* and a default load factor (0.75) and concurrencyLevel (16).
1442	>	* Creates a new, empty map with an initial table size based on
1443	>	* the given number of elements ({@code initialCapacity}), table
1444	>	* density ({@code loadFactor}), and number of concurrently
1445	>	* updating threads ({@code concurrencyLevel}).
1446		*
1447	<	* @param m the map
1447	>	* @param initialCapacity the initial capacity. The implementation
1448	>	* performs internal sizing to accommodate this many elements,
1449	>	* given the specified load factor.
1450	>	* @param loadFactor the load factor (table density) for
1451	>	* establishing the initial table size
1452	>	* @param concurrencyLevel the estimated number of concurrently
1453	>	* updating threads. The implementation may use this value as
1454	>	* a sizing hint.
1455	>	* @throws IllegalArgumentException if the initial capacity is
1456	>	* negative or the load factor or concurrencyLevel are
1457	>	* nonpositive
1458		*/
1459	<	public ConcurrentHashMapV8(Map<? extends K, ? extends V> m) {
1460	<	this(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL);
1461	<	if (m == null)
1462	<	throw new NullPointerException();
1463	<	internalPutAll(m);
1459	>	public ConcurrentHashMapV8(int initialCapacity,
1460	>	float loadFactor, int concurrencyLevel) {
1461	>	if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
1462	>	throw new IllegalArgumentException();
1463	>	if (initialCapacity < concurrencyLevel)   // Use at least as many bins
1464	>	initialCapacity = concurrencyLevel;   // as estimated threads
1465	>	long size = (long)(1.0 + (long)initialCapacity / loadFactor);
1466	>	int cap = ((size >= (long)MAXIMUM_CAPACITY) ?
1467	>	MAXIMUM_CAPACITY: tableSizeFor((int)size));
1468	>	this.counter = new LongAdder();
1469	>	this.sizeCtl = cap;
1470		}
1471
1472		/**
1473	<	* Returns {@code true} if this map contains no key-value mappings.
976	<	*
977	<	* @return {@code true} if this map contains no key-value mappings
1473	>	* {@inheritDoc}
1474		*/
1475		public boolean isEmpty() {
1476		return counter.sum() <= 0L; // ignore transient negative values
1477		}
1478
1479		/**
1480	<	* Returns the number of key-value mappings in this map.  If the
985	<	* map contains more than {@code Integer.MAX_VALUE} elements, returns
986	<	* {@code Integer.MAX_VALUE}.
987	<	*
988	<	* @return the number of key-value mappings in this map
1480	>	* {@inheritDoc}
1481		*/
1482		public int size() {
1483		long n = counter.sum();
1484	<	return ((n >>> 31) == 0) ? (int)n : (n < 0L) ? 0 : Integer.MAX_VALUE;
1484	>	return ((n < 0L) ? 0 :
1485	>	(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
1486	>	(int)n);
1487	>	}
1488	>
1489	>	final long longSize() { // accurate version of size needed for views
1490	>	long n = counter.sum();
1491	>	return (n < 0L) ? 0L : n;
1492		}
1493
1494		/**
#	Line 1016 | Line 1515 | public class ConcurrentHashMapV8<K, V>
1515		* @param  key   possible key
1516		* @return {@code true} if and only if the specified object
1517		*         is a key in this table, as determined by the
1518	<	*         {@code equals} method; {@code false} otherwise.
1518	>	*         {@code equals} method; {@code false} otherwise
1519		* @throws NullPointerException if the specified key is null
1520		*/
1521		public boolean containsKey(Object key) {
#	Line 1027 | Line 1526 | public class ConcurrentHashMapV8<K, V>
1526
1527		/**
1528		* Returns {@code true} if this map maps one or more keys to the
1529	<	* specified value. Note: This method requires a full internal
1530	<	* traversal of the hash table, and so is much slower than
1032	<	* method {@code containsKey}.
1529	>	* specified value. Note: This method may require a full traversal
1530	>	* of the map, and is much slower than method {@code containsKey}.
1531		*
1532		* @param value value whose presence in this map is to be tested
1533		* @return {@code true} if this map maps one or more keys to the
#	Line 1039 | Line 1537 | public class ConcurrentHashMapV8<K, V>
1537		public boolean containsValue(Object value) {
1538		if (value == null)
1539		throw new NullPointerException();
1540	<	return new HashIterator().containsVal(value);
1540	>	Object v;
1541	>	InternalIterator it = new InternalIterator(table);
1542	>	while (it.next != null) {
1543	>	if ((v = it.nextVal) == value || value.equals(v))
1544	>	return true;
1545	>	it.advance();
1546	>	}
1547	>	return false;
1548		}
1549
1550		/**
#	Line 1078 | Line 1583 | public class ConcurrentHashMapV8<K, V>
1583		public V put(K key, V value) {
1584		if (key == null || value == null)
1585		throw new NullPointerException();
1586	<	return (V)internalPut(key, value, true);
1586	>	return (V)internalPut(key, value);
1587		}
1588
1589		/**
#	Line 1092 | Line 1597 | public class ConcurrentHashMapV8<K, V>
1597		public V putIfAbsent(K key, V value) {
1598		if (key == null || value == null)
1599		throw new NullPointerException();
1600	<	return (V)internalPut(key, value, false);
1600	>	return (V)internalPutIfAbsent(key, value);
1601		}
1602
1603		/**
#	Line 1103 | Line 1608 | public class ConcurrentHashMapV8<K, V>
1608		* @param m mappings to be stored in this map
1609		*/
1610		public void putAll(Map<? extends K, ? extends V> m) {
1106	–	if (m == null)
1107	–	throw new NullPointerException();
1611		internalPutAll(m);
1612		}
1613
1614		/**
1615		* If the specified key is not already associated with a value,
1616	<	* computes its value using the given mappingFunction, and if
1617	<	* non-null, enters it into the map.  This is equivalent to
1618	<	*
1619	<	* <pre>
1620	<	*   if (map.containsKey(key))
1621	<	*       return map.get(key);
1622	<	*   value = mappingFunction.map(key);
1623	<	*   if (value != null)
1624	<	*      map.put(key, value);
1625	<	*   return value;
1626	<	* </pre>
1616	>	* computes its value using the given mappingFunction and
1617	>	* enters it into the map.  This is equivalent to
1618	>	* <pre> {@code
1619	>	* if (map.containsKey(key))
1620	>	*   return map.get(key);
1621	>	* value = mappingFunction.map(key);
1622	>	* map.put(key, value);
1623	>	* return value;}</pre>
1624	>	*
1625	>	* except that the action is performed atomically.  If the
1626	>	* function returns {@code null} (in which case a {@code
1627	>	* NullPointerException} is thrown), or the function itself throws
1628	>	* an (unchecked) exception, the exception is rethrown to its
1629	>	* caller, and no mapping is recorded.  Some attempted update
1630	>	* operations on this map by other threads may be blocked while
1631	>	* computation is in progress, so the computation should be short
1632	>	* and simple, and must not attempt to update any other mappings
1633	>	* of this Map. The most appropriate usage is to construct a new
1634	>	* object serving as an initial mapped value, or memoized result,
1635	>	* as in:
1636		*
1637	<	* except that the action is performed atomically.  Some attempted
1126	<	* update operations on this map by other threads may be blocked
1127	<	* while computation is in progress, so the computation should be
1128	<	* short and simple, and must not attempt to update any other
1129	<	* mappings of this Map. The most appropriate usage is to
1130	<	* construct a new object serving as an initial mapped value, or
1131	<	* memoized result, as in:
1132	<	* <pre>{@code
1637	>	*  <pre> {@code
1638		* map.computeIfAbsent(key, new MappingFunction<K, V>() {
1639	<	*   public V map(K k) { return new Value(f(k)); }};
1135	<	* }</pre>
1639	>	*   public V map(K k) { return new Value(f(k)); }});}</pre>
1640		*
1641		* @param key key with which the specified value is to be associated
1642		* @param mappingFunction the function to compute a value
1643		* @return the current (existing or computed) value associated with
1644	<	*         the specified key, or {@code null} if the computation
1645	<	*         returned {@code null}.
1646	<	* @throws NullPointerException if the specified key or mappingFunction
1143	<	*         is null,
1644	>	*         the specified key.
1645	>	* @throws NullPointerException if the specified key, mappingFunction,
1646	>	*         or computed value is null
1647		* @throws IllegalStateException if the computation detectably
1648		*         attempts a recursive update to this map that would
1649	<	*         otherwise never complete.
1649	>	*         otherwise never complete
1650		* @throws RuntimeException or Error if the mappingFunction does so,
1651	<	*         in which case the mapping is left unestablished.
1651	>	*         in which case the mapping is left unestablished
1652		*/
1653	+	@SuppressWarnings("unchecked")
1654		public V computeIfAbsent(K key, MappingFunction<? super K, ? extends V> mappingFunction) {
1655		if (key == null || mappingFunction == null)
1656		throw new NullPointerException();
1657	<	return internalCompute(key, mappingFunction, false);
1657	>	return (V)internalComputeIfAbsent(key, mappingFunction);
1658		}
1659
1660		/**
1661	<	* Computes the value associated with the given key using the given
1662	<	* mappingFunction, and if non-null, enters it into the map.  This
1663	<	* is equivalent to
1664	<	*
1665	<	* <pre>
1666	<	*   value = mappingFunction.map(key);
1163	<	*   if (value != null)
1164	<	*      map.put(key, value);
1165	<	*   else
1166	<	*      value = map.get(key);
1167	<	*   return value;
1168	<	* </pre>
1661	>	* Computes and enters a new mapping value given a key and
1662	>	* its current mapped value (or {@code null} if there is no current
1663	>	* mapping). This is equivalent to
1664	>	*  <pre> {@code
1665	>	*  map.put(key, remappingFunction.remap(key, map.get(key));
1666	>	* }</pre>
1667		*
1668	<	* except that the action is performed atomically.  Some attempted
1668	>	* except that the action is performed atomically.  If the
1669	>	* function returns {@code null} (in which case a {@code
1670	>	* NullPointerException} is thrown), or the function itself throws
1671	>	* an (unchecked) exception, the exception is rethrown to its
1672	>	* caller, and current mapping is left unchanged.  Some attempted
1673		* update operations on this map by other threads may be blocked
1674		* while computation is in progress, so the computation should be
1675		* short and simple, and must not attempt to update any other
1676	<	* mappings of this Map.
1676	>	* mappings of this Map. For example, to either create or
1677	>	* append new messages to a value mapping:
1678	>	*
1679	>	* <pre> {@code
1680	>	* Map<Key, String> map = ...;
1681	>	* final String msg = ...;
1682	>	* map.compute(key, new RemappingFunction<Key, String>() {
1683	>	*   public String remap(Key k, String v) {
1684	>	*    return (v == null) ? msg : v + msg;});}}</pre>
1685		*
1686		* @param key key with which the specified value is to be associated
1687	<	* @param mappingFunction the function to compute a value
1688	<	* @return the current value associated with
1689	<	*         the specified key, or {@code null} if the computation
1690	<	*         returned {@code null} and the value was not otherwise present.
1691	<	* @throws NullPointerException if the specified key or mappingFunction
1182	<	*         is null,
1687	>	* @param remappingFunction the function to compute a value
1688	>	* @return the new value associated with
1689	>	*         the specified key.
1690	>	* @throws NullPointerException if the specified key or remappingFunction
1691	>	*         or computed value is null
1692		* @throws IllegalStateException if the computation detectably
1693		*         attempts a recursive update to this map that would
1694	<	*         otherwise never complete.
1695	<	* @throws RuntimeException or Error if the mappingFunction does so,
1696	<	*         in which case the mapping is unchanged.
1694	>	*         otherwise never complete
1695	>	* @throws RuntimeException or Error if the remappingFunction does so,
1696	>	*         in which case the mapping is unchanged
1697		*/
1698	<	public V compute(K key, MappingFunction<? super K, ? extends V> mappingFunction) {
1699	<	if (key == null || mappingFunction == null)
1698	>	@SuppressWarnings("unchecked")
1699	>	public V compute(K key, RemappingFunction<? super K, V> remappingFunction) {
1700	>	if (key == null || remappingFunction == null)
1701		throw new NullPointerException();
1702	<	return internalCompute(key, mappingFunction, true);
1702	>	return (V)internalCompute(key, remappingFunction);
1703		}
1704
1705		/**
#	Line 1270 | Line 1780 | public class ConcurrentHashMapV8<K, V>
1780		* reflect any modifications subsequent to construction.
1781		*/
1782		public Set<K> keySet() {
1783	<	Set<K> ks = keySet;
1784	<	return (ks != null) ? ks : (keySet = new KeySet());
1783	>	KeySet<K,V> ks = keySet;
1784	>	return (ks != null) ? ks : (keySet = new KeySet<K,V>(this));
1785		}
1786
1787		/**
#	Line 1291 | Line 1801 | public class ConcurrentHashMapV8<K, V>
1801		* reflect any modifications subsequent to construction.
1802		*/
1803		public Collection<V> values() {
1804	<	Collection<V> vs = values;
1805	<	return (vs != null) ? vs : (values = new Values());
1804	>	Values<K,V> vs = values;
1805	>	return (vs != null) ? vs : (values = new Values<K,V>(this));
1806		}
1807
1808		/**
#	Line 1312 | Line 1822 | public class ConcurrentHashMapV8<K, V>
1822		* reflect any modifications subsequent to construction.
1823		*/
1824		public Set<Map.Entry<K,V>> entrySet() {
1825	<	Set<Map.Entry<K,V>> es = entrySet;
1826	<	return (es != null) ? es : (entrySet = new EntrySet());
1825	>	EntrySet<K,V> es = entrySet;
1826	>	return (es != null) ? es : (entrySet = new EntrySet<K,V>(this));
1827		}
1828
1829		/**
#	Line 1323 | Line 1833 | public class ConcurrentHashMapV8<K, V>
1833		* @see #keySet()
1834		*/
1835		public Enumeration<K> keys() {
1836	<	return new KeyIterator();
1836	>	return new KeyIterator<K,V>(this);
1837		}
1838
1839		/**
#	Line 1333 | Line 1843 | public class ConcurrentHashMapV8<K, V>
1843		* @see #values()
1844		*/
1845		public Enumeration<V> elements() {
1846	<	return new ValueIterator();
1846	>	return new ValueIterator<K,V>(this);
1847		}
1848
1849		/**
#	Line 1344 | Line 1854 | public class ConcurrentHashMapV8<K, V>
1854		* @return the hash code value for this map
1855		*/
1856		public int hashCode() {
1857	<	return new HashIterator().mapHashCode();
1857	>	int h = 0;
1858	>	InternalIterator it = new InternalIterator(table);
1859	>	while (it.next != null) {
1860	>	h += it.nextKey.hashCode() ^ it.nextVal.hashCode();
1861	>	it.advance();
1862	>	}
1863	>	return h;
1864		}
1865
1866		/**
#	Line 1359 | Line 1875 | public class ConcurrentHashMapV8<K, V>
1875		* @return a string representation of this map
1876		*/
1877		public String toString() {
1878	<	return new HashIterator().mapToString();
1878	>	InternalIterator it = new InternalIterator(table);
1879	>	StringBuilder sb = new StringBuilder();
1880	>	sb.append('{');
1881	>	if (it.next != null) {
1882	>	for (;;) {
1883	>	Object k = it.nextKey, v = it.nextVal;
1884	>	sb.append(k == this ? "(this Map)" : k);
1885	>	sb.append('=');
1886	>	sb.append(v == this ? "(this Map)" : v);
1887	>	it.advance();
1888	>	if (it.next == null)
1889	>	break;
1890	>	sb.append(',').append(' ');
1891	>	}
1892	>	}
1893	>	return sb.append('}').toString();
1894		}
1895
1896		/**
#	Line 1373 | Line 1904 | public class ConcurrentHashMapV8<K, V>
1904		* @return {@code true} if the specified object is equal to this map
1905		*/
1906		public boolean equals(Object o) {
1907	<	if (o == this)
1908	<	return true;
1909	<	if (!(o instanceof Map))
1910	<	return false;
1911	<	Map<?,?> m = (Map<?,?>) o;
1912	<	try {
1913	<	for (Map.Entry<K,V> e : this.entrySet())
1914	<	if (! e.getValue().equals(m.get(e.getKey())))
1907	>	if (o != this) {
1908	>	if (!(o instanceof Map))
1909	>	return false;
1910	>	Map<?,?> m = (Map<?,?>) o;
1911	>	InternalIterator it = new InternalIterator(table);
1912	>	while (it.next != null) {
1913	>	Object val = it.nextVal;
1914	>	Object v = m.get(it.nextKey);
1915	>	if (v == null || (v != val && !v.equals(val)))
1916		return false;
1917	+	it.advance();
1918	+	}
1919		for (Map.Entry<?,?> e : m.entrySet()) {
1920	<	Object k = e.getKey();
1921	<	Object v = e.getValue();
1922	<	if (k == null || v == null || !v.equals(get(k)))
1920	>	Object mk, mv, v;
1921	>	if ((mk = e.getKey()) == null ||
1922	>	(mv = e.getValue()) == null ||
1923	>	(v = internalGet(mk)) == null ||
1924	>	(mv != v && !mv.equals(v)))
1925		return false;
1926		}
1391	–	return true;
1392	–	} catch (ClassCastException unused) {
1393	–	return false;
1394	–	} catch (NullPointerException unused) {
1395	–	return false;
1927		}
1928	+	return true;
1929		}
1930
1931	+	/* ----------------Iterators -------------- */
1932	+
1933		/**
1934	<	* Custom Entry class used by EntryIterator.next(), that relays
1935	<	* setValue changes to the underlying map.
1934	>	* Base class for key, value, and entry iterators.  Adds a map
1935	>	* reference to InternalIterator to support Iterator.remove.
1936		*/
1937	<	final class WriteThroughEntry extends AbstractMap.SimpleEntry<K,V> {
1937	>	static abstract class ViewIterator<K,V> extends InternalIterator {
1938	>	final ConcurrentHashMapV8<K, V> map;
1939	>	ViewIterator(ConcurrentHashMapV8<K, V> map) {
1940	>	super(map.table);
1941	>	this.map = map;
1942	>	}
1943	>
1944	>	public final void remove() {
1945	>	if (last == null)
1946	>	throw new IllegalStateException();
1947	>	map.remove(last.key);
1948	>	last = null;
1949	>	}
1950	>
1951	>	public final boolean hasNext()         { return next != null; }
1952	>	public final boolean hasMoreElements() { return next != null; }
1953	>	}
1954	>
1955	>	static final class KeyIterator<K,V> extends ViewIterator<K,V>
1956	>	implements Iterator<K>, Enumeration<K> {
1957	>	KeyIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
1958	>
1959		@SuppressWarnings("unchecked")
1960	<	WriteThroughEntry(Object k, Object v) {
1961	<	super((K)k, (V)v);
1960	>	public final K next() {
1961	>	if (next == null)
1962	>	throw new NoSuchElementException();
1963	>	Object k = nextKey;
1964	>	advance();
1965	>	return (K)k;
1966	>	}
1967	>
1968	>	public final K nextElement() { return next(); }
1969	>	}
1970	>
1971	>	static final class ValueIterator<K,V> extends ViewIterator<K,V>
1972	>	implements Iterator<V>, Enumeration<V> {
1973	>	ValueIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
1974	>
1975	>	@SuppressWarnings("unchecked")
1976	>	public final V next() {
1977	>	if (next == null)
1978	>	throw new NoSuchElementException();
1979	>	Object v = nextVal;
1980	>	advance();
1981	>	return (V)v;
1982	>	}
1983	>
1984	>	public final V nextElement() { return next(); }
1985	>	}
1986	>
1987	>	static final class EntryIterator<K,V> extends ViewIterator<K,V>
1988	>	implements Iterator<Map.Entry<K,V>> {
1989	>	EntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
1990	>
1991	>	@SuppressWarnings("unchecked")
1992	>	public final Map.Entry<K,V> next() {
1993	>	if (next == null)
1994	>	throw new NoSuchElementException();
1995	>	Object k = nextKey;
1996	>	Object v = nextVal;
1997	>	advance();
1998	>	return new WriteThroughEntry<K,V>((K)k, (V)v, map);
1999	>	}
2000	>	}
2001	>
2002	>	static final class SnapshotEntryIterator<K,V> extends ViewIterator<K,V>
2003	>	implements Iterator<Map.Entry<K,V>> {
2004	>	SnapshotEntryIterator(ConcurrentHashMapV8<K, V> map) { super(map); }
2005	>
2006	>	@SuppressWarnings("unchecked")
2007	>	public final Map.Entry<K,V> next() {
2008	>	if (next == null)
2009	>	throw new NoSuchElementException();
2010	>	Object k = nextKey;
2011	>	Object v = nextVal;
2012	>	advance();
2013	>	return new SnapshotEntry<K,V>((K)k, (V)v);
2014	>	}
2015	>	}
2016	>
2017	>	/**
2018	>	* Base of writeThrough and Snapshot entry classes
2019	>	*/
2020	>	static abstract class MapEntry<K,V> implements Map.Entry<K, V> {
2021	>	final K key; // non-null
2022	>	V val;       // non-null
2023	>	MapEntry(K key, V val)        { this.key = key; this.val = val; }
2024	>	public final K getKey()       { return key; }
2025	>	public final V getValue()     { return val; }
2026	>	public final int hashCode()   { return key.hashCode() ^ val.hashCode(); }
2027	>	public final String toString(){ return key + "=" + val; }
2028	>
2029	>	public final boolean equals(Object o) {
2030	>	Object k, v; Map.Entry<?,?> e;
2031	>	return ((o instanceof Map.Entry) &&
2032	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
2033	>	(v = e.getValue()) != null &&
2034	>	(k == key || k.equals(key)) &&
2035	>	(v == val || v.equals(val)));
2036	>	}
2037	>
2038	>	public abstract V setValue(V value);
2039	>	}
2040	>
2041	>	/**
2042	>	* Entry used by EntryIterator.next(), that relays setValue
2043	>	* changes to the underlying map.
2044	>	*/
2045	>	static final class WriteThroughEntry<K,V> extends MapEntry<K,V>
2046	>	implements Map.Entry<K, V> {
2047	>	final ConcurrentHashMapV8<K, V> map;
2048	>	WriteThroughEntry(K key, V val, ConcurrentHashMapV8<K, V> map) {
2049	>	super(key, val);
2050	>	this.map = map;
2051		}
2052
2053		/**
#	Line 1415 | Line 2059 | public class ConcurrentHashMapV8<K, V>
2059		* removed in which case the put will re-establish). We do not
2060		* and cannot guarantee more.
2061		*/
2062	<	public V setValue(V value) {
2062	>	public final V setValue(V value) {
2063		if (value == null) throw new NullPointerException();
2064	<	V v = super.setValue(value);
2065	<	ConcurrentHashMapV8.this.put(getKey(), value);
2064	>	V v = val;
2065	>	val = value;
2066	>	map.put(key, value);
2067		return v;
2068		}
2069		}
2070
2071	<	final class KeyIterator extends HashIterator
2072	<	implements Iterator<K>, Enumeration<K> {
2073	<	@SuppressWarnings("unchecked")
2074	<	public final K next()        { return (K)super.nextKey(); }
2075	<	@SuppressWarnings("unchecked")
2076	<	public final K nextElement() { return (K)super.nextKey(); }
2071	>	/**
2072	>	* Internal version of entry, that doesn't write though changes
2073	>	*/
2074	>	static final class SnapshotEntry<K,V> extends MapEntry<K,V>
2075	>	implements Map.Entry<K, V> {
2076	>	SnapshotEntry(K key, V val) { super(key, val); }
2077	>	public final V setValue(V value) { // only locally update
2078	>	if (value == null) throw new NullPointerException();
2079	>	V v = val;
2080	>	val = value;
2081	>	return v;
2082	>	}
2083		}
2084
2085	<	final class ValueIterator extends HashIterator
2086	<	implements Iterator<V>, Enumeration<V> {
2087	<	@SuppressWarnings("unchecked")
2088	<	public final V next()        { return (V)super.nextValue(); }
2085	>	/* ----------------Views -------------- */
2086	>
2087	>	/**
2088	>	* Base class for views. This is done mainly to allow adding
2089	>	* customized parallel traversals (not yet implemented.)
2090	>	*/
2091	>	static abstract class MapView<K, V> {
2092	>	final ConcurrentHashMapV8<K, V> map;
2093	>	MapView(ConcurrentHashMapV8<K, V> map)  { this.map = map; }
2094	>	public final int size()                 { return map.size(); }
2095	>	public final boolean isEmpty()          { return map.isEmpty(); }
2096	>	public final void clear()               { map.clear(); }
2097	>
2098	>	// implementations below rely on concrete classes supplying these
2099	>	abstract Iterator<?> iter();
2100	>	abstract public boolean contains(Object o);
2101	>	abstract public boolean remove(Object o);
2102	>
2103	>	private static final String oomeMsg = "Required array size too large";
2104	>
2105	>	public final Object[] toArray() {
2106	>	long sz = map.longSize();
2107	>	if (sz > (long)(MAX_ARRAY_SIZE))
2108	>	throw new OutOfMemoryError(oomeMsg);
2109	>	int n = (int)sz;
2110	>	Object[] r = new Object[n];
2111	>	int i = 0;
2112	>	Iterator<?> it = iter();
2113	>	while (it.hasNext()) {
2114	>	if (i == n) {
2115	>	if (n >= MAX_ARRAY_SIZE)
2116	>	throw new OutOfMemoryError(oomeMsg);
2117	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
2118	>	n = MAX_ARRAY_SIZE;
2119	>	else
2120	>	n += (n >>> 1) + 1;
2121	>	r = Arrays.copyOf(r, n);
2122	>	}
2123	>	r[i++] = it.next();
2124	>	}
2125	>	return (i == n) ? r : Arrays.copyOf(r, i);
2126	>	}
2127	>
2128		@SuppressWarnings("unchecked")
2129	<	public final V nextElement() { return (V)super.nextValue(); }
2130	<	}
2129	>	public final <T> T[] toArray(T[] a) {
2130	>	long sz = map.longSize();
2131	>	if (sz > (long)(MAX_ARRAY_SIZE))
2132	>	throw new OutOfMemoryError(oomeMsg);
2133	>	int m = (int)sz;
2134	>	T[] r = (a.length >= m) ? a :
2135	>	(T[])java.lang.reflect.Array
2136	>	.newInstance(a.getClass().getComponentType(), m);
2137	>	int n = r.length;
2138	>	int i = 0;
2139	>	Iterator<?> it = iter();
2140	>	while (it.hasNext()) {
2141	>	if (i == n) {
2142	>	if (n >= MAX_ARRAY_SIZE)
2143	>	throw new OutOfMemoryError(oomeMsg);
2144	>	if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
2145	>	n = MAX_ARRAY_SIZE;
2146	>	else
2147	>	n += (n >>> 1) + 1;
2148	>	r = Arrays.copyOf(r, n);
2149	>	}
2150	>	r[i++] = (T)it.next();
2151	>	}
2152	>	if (a == r && i < n) {
2153	>	r[i] = null; // null-terminate
2154	>	return r;
2155	>	}
2156	>	return (i == n) ? r : Arrays.copyOf(r, i);
2157	>	}
2158
2159	<	final class EntryIterator extends HashIterator
2160	<	implements Iterator<Entry<K,V>> {
2161	<	public final Map.Entry<K,V> next() { return super.nextEntry(); }
2162	<	}
2159	>	public final int hashCode() {
2160	>	int h = 0;
2161	>	for (Iterator<?> it = iter(); it.hasNext();)
2162	>	h += it.next().hashCode();
2163	>	return h;
2164	>	}
2165	>
2166	>	public final String toString() {
2167	>	StringBuilder sb = new StringBuilder();
2168	>	sb.append('[');
2169	>	Iterator<?> it = iter();
2170	>	if (it.hasNext()) {
2171	>	for (;;) {
2172	>	Object e = it.next();
2173	>	sb.append(e == this ? "(this Collection)" : e);
2174	>	if (!it.hasNext())
2175	>	break;
2176	>	sb.append(',').append(' ');
2177	>	}
2178	>	}
2179	>	return sb.append(']').toString();
2180	>	}
2181	>
2182	>	public final boolean containsAll(Collection<?> c) {
2183	>	if (c != this) {
2184	>	for (Iterator<?> it = c.iterator(); it.hasNext();) {
2185	>	Object e = it.next();
2186	>	if (e == null || !contains(e))
2187	>	return false;
2188	>	}
2189	>	}
2190	>	return true;
2191	>	}
2192
2193	<	final class KeySet extends AbstractSet<K> {
2194	<	public int size() {
2195	<	return ConcurrentHashMapV8.this.size();
2193	>	public final boolean removeAll(Collection<?> c) {
2194	>	boolean modified = false;
2195	>	for (Iterator<?> it = iter(); it.hasNext();) {
2196	>	if (c.contains(it.next())) {
2197	>	it.remove();
2198	>	modified = true;
2199	>	}
2200	>	}
2201	>	return modified;
2202		}
2203	<	public boolean isEmpty() {
2204	<	return ConcurrentHashMapV8.this.isEmpty();
2203	>
2204	>	public final boolean retainAll(Collection<?> c) {
2205	>	boolean modified = false;
2206	>	for (Iterator<?> it = iter(); it.hasNext();) {
2207	>	if (!c.contains(it.next())) {
2208	>	it.remove();
2209	>	modified = true;
2210	>	}
2211	>	}
2212	>	return modified;
2213	>	}
2214	>
2215	>	}
2216	>
2217	>	static final class KeySet<K,V> extends MapView<K,V> implements Set<K> {
2218	>	KeySet(ConcurrentHashMapV8<K, V> map)   { super(map); }
2219	>	public final boolean contains(Object o) { return map.containsKey(o); }
2220	>	public final boolean remove(Object o)   { return map.remove(o) != null; }
2221	>
2222	>	public final Iterator<K> iterator() {
2223	>	return new KeyIterator<K,V>(map);
2224		}
2225	<	public void clear() {
2226	<	ConcurrentHashMapV8.this.clear();
2225	>	final Iterator<?> iter() {
2226	>	return new KeyIterator<K,V>(map);
2227		}
2228	<	public Iterator<K> iterator() {
2229	<	return new KeyIterator();
2228	>	public final boolean add(K e) {
2229	>	throw new UnsupportedOperationException();
2230		}
2231	<	public boolean contains(Object o) {
2232	<	return ConcurrentHashMapV8.this.containsKey(o);
2231	>	public final boolean addAll(Collection<? extends K> c) {
2232	>	throw new UnsupportedOperationException();
2233		}
2234	<	public boolean remove(Object o) {
2235	<	return ConcurrentHashMapV8.this.remove(o) != null;
2234	>	public boolean equals(Object o) {
2235	>	Set<?> c;
2236	>	return ((o instanceof Set) &&
2237	>	((c = (Set<?>)o) == this ||
2238	>	(containsAll(c) && c.containsAll(this))));
2239		}
2240		}
2241
2242	<	final class Values extends AbstractCollection<V> {
2243	<	public int size() {
2244	<	return ConcurrentHashMapV8.this.size();
2242	>	static final class Values<K,V> extends MapView<K,V>
2243	>	implements Collection<V> {
2244	>	Values(ConcurrentHashMapV8<K, V> map)   { super(map); }
2245	>	public final boolean contains(Object o) { return map.containsValue(o); }
2246	>
2247	>	public final boolean remove(Object o) {
2248	>	if (o != null) {
2249	>	Iterator<V> it = new ValueIterator<K,V>(map);
2250	>	while (it.hasNext()) {
2251	>	if (o.equals(it.next())) {
2252	>	it.remove();
2253	>	return true;
2254	>	}
2255	>	}
2256	>	}
2257	>	return false;
2258		}
2259	<	public boolean isEmpty() {
2260	<	return ConcurrentHashMapV8.this.isEmpty();
2259	>	public final Iterator<V> iterator() {
2260	>	return new ValueIterator<K,V>(map);
2261		}
2262	<	public void clear() {
2263	<	ConcurrentHashMapV8.this.clear();
2262	>	final Iterator<?> iter() {
2263	>	return new ValueIterator<K,V>(map);
2264		}
2265	<	public Iterator<V> iterator() {
2266	<	return new ValueIterator();
2265	>	public final boolean add(V e) {
2266	>	throw new UnsupportedOperationException();
2267		}
2268	<	public boolean contains(Object o) {
2269	<	return ConcurrentHashMapV8.this.containsValue(o);
2268	>	public final boolean addAll(Collection<? extends V> c) {
2269	>	throw new UnsupportedOperationException();
2270		}
2271		}
2272
2273	<	final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
2274	<	public int size() {
2275	<	return ConcurrentHashMapV8.this.size();
2273	>	static final class EntrySet<K,V> extends MapView<K,V>
2274	>	implements Set<Map.Entry<K,V>> {
2275	>	EntrySet(ConcurrentHashMapV8<K, V> map) { super(map); }
2276	>
2277	>	public final boolean contains(Object o) {
2278	>	Object k, v, r; Map.Entry<?,?> e;
2279	>	return ((o instanceof Map.Entry) &&
2280	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
2281	>	(r = map.get(k)) != null &&
2282	>	(v = e.getValue()) != null &&
2283	>	(v == r || v.equals(r)));
2284		}
2285	<	public boolean isEmpty() {
2286	<	return ConcurrentHashMapV8.this.isEmpty();
2285	>
2286	>	public final boolean remove(Object o) {
2287	>	Object k, v; Map.Entry<?,?> e;
2288	>	return ((o instanceof Map.Entry) &&
2289	>	(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
2290	>	(v = e.getValue()) != null &&
2291	>	map.remove(k, v));
2292		}
2293	<	public void clear() {
2294	<	ConcurrentHashMapV8.this.clear();
2293	>
2294	>	public final Iterator<Map.Entry<K,V>> iterator() {
2295	>	return new EntryIterator<K,V>(map);
2296		}
2297	<	public Iterator<Map.Entry<K,V>> iterator() {
2298	<	return new EntryIterator();
2297	>	final Iterator<?> iter() {
2298	>	return new SnapshotEntryIterator<K,V>(map);
2299		}
2300	<	public boolean contains(Object o) {
2301	<	if (!(o instanceof Map.Entry))
1501	<	return false;
1502	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
1503	<	V v = ConcurrentHashMapV8.this.get(e.getKey());
1504	<	return v != null && v.equals(e.getValue());
2300	>	public final boolean add(Entry<K,V> e) {
2301	>	throw new UnsupportedOperationException();
2302		}
2303	<	public boolean remove(Object o) {
2304	<	if (!(o instanceof Map.Entry))
2305	<	return false;
2306	<	Map.Entry<?,?> e = (Map.Entry<?,?>)o;
2307	<	return ConcurrentHashMapV8.this.remove(e.getKey(), e.getValue());
2303	>	public final boolean addAll(Collection<? extends Entry<K,V>> c) {
2304	>	throw new UnsupportedOperationException();
2305	>	}
2306	>	public boolean equals(Object o) {
2307	>	Set<?> c;
2308	>	return ((o instanceof Set) &&
2309	>	((c = (Set<?>)o) == this ||
2310	>	(containsAll(c) && c.containsAll(this))));
2311		}
2312		}
2313
2314		/* ---------------- Serialization Support -------------- */
2315
2316		/**
2317	<	* Helper class used in previous version, declared for the sake of
2318	<	* serialization compatibility
2317	>	* Stripped-down version of helper class used in previous version,
2318	>	* declared for the sake of serialization compatibility
2319		*/
2320	<	static class Segment<K,V> extends java.util.concurrent.locks.ReentrantLock
1521	<	implements Serializable {
2320	>	static class Segment<K,V> implements Serializable {
2321		private static final long serialVersionUID = 2249069246763182397L;
2322		final float loadFactor;
2323		Segment(float lf) { this.loadFactor = lf; }
#	Line 1540 | Line 2339 | public class ConcurrentHashMapV8<K, V>
2339		segments = (Segment<K,V>[])
2340		new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
2341		for (int i = 0; i < segments.length; ++i)
2342	<	segments[i] = new Segment<K,V>(loadFactor);
2342	>	segments[i] = new Segment<K,V>(LOAD_FACTOR);
2343		}
2344		s.defaultWriteObject();
2345	<	new HashIterator().writeEntries(s);
2345	>	InternalIterator it = new InternalIterator(table);
2346	>	while (it.next != null) {
2347	>	s.writeObject(it.nextKey);
2348	>	s.writeObject(it.nextVal);
2349	>	it.advance();
2350	>	}
2351		s.writeObject(null);
2352		s.writeObject(null);
2353		segments = null; // throw away
2354		}
2355
2356		/**
2357	<	* Reconstitutes the  instance from a
1554	<	* stream (i.e., deserializes it).
2357	>	* Reconstitutes the instance from a stream (that is, deserializes it).
2358		* @param s the stream
2359		*/
2360		@SuppressWarnings("unchecked")
2361		private void readObject(java.io.ObjectInputStream s)
2362		throws java.io.IOException, ClassNotFoundException {
2363		s.defaultReadObject();
1561	–	// find load factor in a segment, if one exists
1562	–	if (segments != null && segments.length != 0)
1563	–	this.loadFactor = segments[0].loadFactor;
1564	–	else
1565	–	this.loadFactor = DEFAULT_LOAD_FACTOR;
1566	–	this.initCap = DEFAULT_CAPACITY;
1567	–	LongAdder ct = new LongAdder(); // force final field write
1568	–	UNSAFE.putObjectVolatile(this, counterOffset, ct);
2364		this.segments = null; // unneeded
2365	+	// initialize transient final field
2366	+	UNSAFE.putObjectVolatile(this, counterOffset, new LongAdder());
2367
2368	<	// Read the keys and values, and put the mappings in the table
2368	>	// Create all nodes, then place in table once size is known
2369	>	long size = 0L;
2370	>	Node p = null;
2371		for (;;) {
2372	<	K key = (K) s.readObject();
2373	<	V value = (V) s.readObject();
2374	<	if (key == null)
2372	>	K k = (K) s.readObject();
2373	>	V v = (V) s.readObject();
2374	>	if (k != null && v != null) {
2375	>	p = new Node(spread(k.hashCode()), k, v, p);
2376	>	++size;
2377	>	}
2378	>	else
2379		break;
2380	<	put(key, value);
2380	>	}
2381	>	if (p != null) {
2382	>	boolean init = false;
2383	>	int n;
2384	>	if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
2385	>	n = MAXIMUM_CAPACITY;
2386	>	else {
2387	>	int sz = (int)size;
2388	>	n = tableSizeFor(sz + (sz >>> 1) + 1);
2389	>	}
2390	>	int sc = sizeCtl;
2391	>	if (n > sc &&
2392	>	UNSAFE.compareAndSwapInt(this, sizeCtlOffset, sc, -1)) {
2393	>	try {
2394	>	if (table == null) {
2395	>	init = true;
2396	>	Node[] tab = new Node[n];
2397	>	int mask = n - 1;
2398	>	while (p != null) {
2399	>	int j = p.hash & mask;
2400	>	Node next = p.next;
2401	>	p.next = tabAt(tab, j);
2402	>	setTabAt(tab, j, p);
2403	>	p = next;
2404	>	}
2405	>	table = tab;
2406	>	counter.add(size);
2407	>	sc = n - (n >>> 2);
2408	>	}
2409	>	} finally {
2410	>	sizeCtl = sc;
2411	>	}
2412	>	}
2413	>	if (!init) { // Can only happen if unsafely published.
2414	>	while (p != null) {
2415	>	internalPut(p.key, p.val);
2416	>	p = p.next;
2417	>	}
2418	>	}
2419		}
2420		}
2421
2422		// Unsafe mechanics
2423		private static final sun.misc.Unsafe UNSAFE;
2424		private static final long counterOffset;
2425	<	private static final long resizingOffset;
2425	>	private static final long sizeCtlOffset;
2426		private static final long ABASE;
2427		private static final int ASHIFT;
2428
#	Line 1592 | Line 2433 | public class ConcurrentHashMapV8<K, V>
2433		Class<?> k = ConcurrentHashMapV8.class;
2434		counterOffset = UNSAFE.objectFieldOffset
2435		(k.getDeclaredField("counter"));
2436	<	resizingOffset = UNSAFE.objectFieldOffset
2437	<	(k.getDeclaredField("resizing"));
2436	>	sizeCtlOffset = UNSAFE.objectFieldOffset
2437	>	(k.getDeclaredField("sizeCtl"));
2438		Class<?> sc = Node[].class;
2439		ABASE = UNSAFE.arrayBaseOffset(sc);
2440		ss = UNSAFE.arrayIndexScale(sc);

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