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root/jsr166/jsr166/src/jsr166e/StampedLock.java

Comparing jsr166/src/jsr166e/StampedLock.java (file contents):
Revision 1.12 by jsr166, Sat Oct 13 23:05:13 2012 UTC vs.
Revision 1.18 by jsr166, Mon Oct 15 05:26:53 2012 UTC

#	Line 180 | Line 180 | public class StampedLock implements java
180		* read-locked.  The read count is ignored when validating
181		* "optimistic" seqlock-reader-style stamps.  Because we must use
182		* a small finite number of bits (currently 7) for readers, a
183	<	* supplementary reader overflow word is used when then number of
183	>	* supplementary reader overflow word is used when the number of
184		* readers exceeds the count field. We do this by treating the max
185		* reader count value (RBITS) as a spinlock protecting overflow
186		* updates.
#	Line 261 | Line 261 | public class StampedLock implements java
261		private static final int OVERFLOW_YIELD_RATE = 7; // must be power 2 - 1
262
263		/** The number of bits to use for reader count before overflowing */
264	<	private static final int  LG_READERS = 7;
264	>	private static final int LG_READERS = 7;
265
266		// Values for lock state and stamp operations
267		private static final long RUNIT = 1L;
#	Line 310 | Line 310 | public class StampedLock implements java
310		private transient int readerOverflow;
311
312		/**
313	<	* Creates a new lock initially in unlocked state.
313	>	* Creates a new lock, initially in unlocked state.
314		*/
315		public StampedLock() {
316		state = ORIGIN;
#	Line 334 | Line 334 | public class StampedLock implements java
334		* Exclusively acquires the lock if it is immediately available.
335		*
336		* @return a stamp that can be used to unlock or convert mode,
337	<	* or zero if the lock is not available.
337	>	* or zero if the lock is not available
338		*/
339		public long tryWriteLock() {
340		long s, next;
#	Line 667 | Line 667 | public class StampedLock implements java
667		else if (m == WBIT) {
668		if (a != m)
669		break;
670	<	next = state = s + (WBIT + RUNIT);
670	>	state = next = s + (WBIT + RUNIT);
671		readerPrefSignal();
672		return next;
673		}
#	Line 701 | Line 701 | public class StampedLock implements java
701		else if (m == WBIT) {
702		if (a != m)
703		break;
704	<	next = state = (s += WBIT) == 0L ? ORIGIN : s;
704	>	state = next = (s += WBIT) == 0L ? ORIGIN : s;
705		readerPrefSignal();
706		return next;
707		}

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