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root/jsr166/jsr166/src/jsr166y/ForkJoinPool.java

Comparing jsr166/src/jsr166y/ForkJoinPool.java (file contents):
Revision 1.166 by jsr166, Sun Dec 30 00:03:36 2012 UTC vs.
Revision 1.173 by jsr166, Wed Jan 9 02:51:37 2013 UTC

#	Line 440 | Line 440 | public class ForkJoinPool extends Abstra
440		* Common Pool
441		* ===========
442		*
443	<	* The static commonPool always exists after static
443	>	* The static common Pool always exists after static
444		* initialization.  Since it (or any other created pool) need
445		* never be used, we minimize initial construction overhead and
446		* footprint to the setup of about a dozen fields, with no nested
#	Line 1074 | Line 1074 | public class ForkJoinPool extends Abstra
1074		* to paranoically avoid potential initialization circularities
1075		* as well as to simplify generated code.
1076		*/
1077	<	static final ForkJoinPool commonPool;
1077	>	static final ForkJoinPool common;
1078
1079		/**
1080	<	* Common pool parallelism. Must equal commonPool.parallelism.
1080	>	* Common pool parallelism. Must equal common.parallelism.
1081		*/
1082	<	static final int commonPoolParallelism;
1082	>	static final int commonParallelism;
1083
1084		/**
1085		* Sequence number for creating workerNamePrefix.
#	Line 1661 | Line 1661 | public class ForkJoinPool extends Abstra
1661		* park awaiting signal, else lingering to help scan and signal.
1662		*
1663		* * If a non-empty queue discovered or left as a hint,
1664	<	* help wake up other workers before return
1664	>	* help wake up other workers before return.
1665		*
1666		* @param w the worker (via its WorkQueue)
1667		* @return a task or null if none found
#	Line 1932 | Line 1932 | public class ForkJoinPool extends Abstra
1932		* @param task the task to join
1933		* @param mode if shared, exit upon completing any task
1934		* if all workers are active
1935	–	*
1935		*/
1936		private int helpComplete(ForkJoinTask<?> task, int mode) {
1937		WorkQueue[] ws; WorkQueue q; int m, n, s, u;
#	Line 2241 | Line 2240 | public class ForkJoinPool extends Abstra
2240		*/
2241		private boolean tryTerminate(boolean now, boolean enable) {
2242		int ps;
2243	<	if (this == commonPool)                    // cannot shut down
2243	>	if (this == common)                    // cannot shut down
2244		return false;
2245		if ((ps = plock) >= 0) {                   // enable by setting plock
2246		if (!enable)
#	Line 2332 | Line 2331 | public class ForkJoinPool extends Abstra
2331		static WorkQueue commonSubmitterQueue() {
2332		ForkJoinPool p; WorkQueue[] ws; int m; Submitter z;
2333		return ((z = submitters.get()) != null &&
2334	<	(p = commonPool) != null &&
2334	>	(p = common) != null &&
2335		(ws = p.workQueues) != null &&
2336		(m = ws.length - 1) >= 0) ?
2337		ws[m & z.seed & SQMASK] : null;
#	Line 2346 | Line 2345 | public class ForkJoinPool extends Abstra
2345		ForkJoinTask<?>[] a;  int m, s;
2346		if (t != null &&
2347		(z = submitters.get()) != null &&
2348	<	(p = commonPool) != null &&
2348	>	(p = common) != null &&
2349		(ws = p.workQueues) != null &&
2350		(m = ws.length - 1) >= 0 &&
2351		(q = ws[m & z.seed & SQMASK]) != null &&
#	Line 2423 | Line 2422 | public class ForkJoinPool extends Abstra
2422		ForkJoinTask<?>[] a;  int m, s, n;
2423		if (t != null &&
2424		(z = submitters.get()) != null &&
2425	<	(p = commonPool) != null &&
2425	>	(p = common) != null &&
2426		(ws = p.workQueues) != null &&
2427		(m = ws.length - 1) >= 0 &&
2428		(q = ws[m & z.seed & SQMASK]) != null &&
#	Line 2452 | Line 2451 | public class ForkJoinPool extends Abstra
2451		}
2452		}
2453
2455	–	/**
2456	–	* Restricted version of helpQuiescePool for external callers
2457	–	*/
2458	–	static void externalHelpQuiescePool() {
2459	–	ForkJoinPool p; ForkJoinTask<?> t; WorkQueue q; int b;
2460	–	if ((p = commonPool) != null &&
2461	–	(q = p.findNonEmptyStealQueue(1)) != null &&
2462	–	(b = q.base) - q.top < 0 &&
2463	–	(t = q.pollAt(b)) != null) {
2464	–	if (q.base - q.top < 0)
2465	–	p.signalWork(q);
2466	–	t.doExec();
2467	–	}
2468	–	}
2469	–
2454		// Exported methods
2455
2456		// Constructors
#	Line 2566 | Line 2550 | public class ForkJoinPool extends Abstra
2550
2551		/**
2552		* Returns the common pool instance. This pool is statically
2553	<	* constructed; its run state is unaffected by attempts to
2554	<	* {@link #shutdown} or {@link #shutdownNow}.
2553	>	* constructed; its run state is unaffected by attempts to {@link
2554	>	* #shutdown} or {@link #shutdownNow}. However this pool and any
2555	>	* ongoing processing are automatically terminated upon program
2556	>	* {@link System#exit}.  Any program that relies on asynchronous
2557	>	* task processing to complete before program termination should
2558	>	* invoke {@code commonPool().}{@link #awaitQuiescence}, before
2559	>	* exit.
2560		*
2561		* @return the common pool instance
2562	+	* @since 1.8
2563		*/
2564		public static ForkJoinPool commonPool() {
2565	<	// assert commonPool != null : "static init error";
2566	<	return commonPool;
2565	>	// assert common != null : "static init error";
2566	>	return common;
2567		}
2568
2569		// Execution methods
#	Line 2752 | Line 2742 | public class ForkJoinPool extends Abstra
2742		* Returns the targeted parallelism level of the common pool.
2743		*
2744		* @return the targeted parallelism level of the common pool
2745	+	* @since 1.8
2746		*/
2747		public static int getCommonPoolParallelism() {
2748	<	return commonPoolParallelism;
2748	>	return commonParallelism;
2749		}
2750
2751		/**
#	Line 3012 | Line 3003 | public class ForkJoinPool extends Abstra
3003		* Possibly initiates an orderly shutdown in which previously
3004		* submitted tasks are executed, but no new tasks will be
3005		* accepted. Invocation has no effect on execution state if this
3006	<	* is the {@link #commonPool}, and no additional effect if
3006	>	* is the {@link #commonPool()}, and no additional effect if
3007		* already shut down.  Tasks that are in the process of being
3008		* submitted concurrently during the course of this method may or
3009		* may not be rejected.
#	Line 3030 | Line 3021 | public class ForkJoinPool extends Abstra
3021		/**
3022		* Possibly attempts to cancel and/or stop all tasks, and reject
3023		* all subsequently submitted tasks.  Invocation has no effect on
3024	<	* execution state if this is the {@link #commonPool}, and no
3024	>	* execution state if this is the {@link #commonPool()}, and no
3025		* additional effect if already shut down. Otherwise, tasks that
3026		* are in the process of being submitted or executed concurrently
3027		* during the course of this method may or may not be
#	Line 3093 | Line 3084 | public class ForkJoinPool extends Abstra
3084		/**
3085		* Blocks until all tasks have completed execution after a
3086		* shutdown request, or the timeout occurs, or the current thread
3087	<	* is interrupted, whichever happens first. Note that the {@link
3088	<	* #commonPool()} never terminates until program shutdown so
3089	<	* this method will always time out.
3087	>	* is interrupted, whichever happens first. Because the {@link
3088	>	* #commonPool()} never terminates until program shutdown, when
3089	>	* applied to the common pool, this method is equivalent to {@link
3090	>	* #awaitQuiescence} but always returns {@code false}.
3091		*
3092		* @param timeout the maximum time to wait
3093		* @param unit the time unit of the timeout argument
#	Line 3105 | Line 3097 | public class ForkJoinPool extends Abstra
3097		*/
3098		public boolean awaitTermination(long timeout, TimeUnit unit)
3099		throws InterruptedException {
3100	+	if (Thread.interrupted())
3101	+	throw new InterruptedException();
3102	+	if (this == common) {
3103	+	awaitQuiescence(timeout, unit);
3104	+	return false;
3105	+	}
3106		long nanos = unit.toNanos(timeout);
3107		if (isTerminated())
3108		return true;
#	Line 3124 | Line 3122 | public class ForkJoinPool extends Abstra
3122		}
3123
3124		/**
3125	+	* If called by a ForkJoinTask operating in this pool, equivalent
3126	+	* in effect to {@link ForkJoinTask#helpQuiesce}. Otherwise,
3127	+	* waits and/or attempts to assist performing tasks until this
3128	+	* pool {@link #isQuiescent} or the indicated timeout elapses.
3129	+	*
3130	+	* @param timeout the maximum time to wait
3131	+	* @param unit the time unit of the timeout argument
3132	+	* @return {@code true} if quiescent; {@code false} if the
3133	+	* timeout elapsed.
3134	+	*/
3135	+	public boolean awaitQuiescence(long timeout, TimeUnit unit) {
3136	+	long nanos = unit.toNanos(timeout);
3137	+	ForkJoinWorkerThread wt;
3138	+	Thread thread = Thread.currentThread();
3139	+	if ((thread instanceof ForkJoinWorkerThread) &&
3140	+	(wt = (ForkJoinWorkerThread)thread).pool == this) {
3141	+	helpQuiescePool(wt.workQueue);
3142	+	return true;
3143	+	}
3144	+	long startTime = System.nanoTime();
3145	+	WorkQueue[] ws;
3146	+	int r = 0, m;
3147	+	boolean found = true;
3148	+	while (!isQuiescent() && (ws = workQueues) != null &&
3149	+	(m = ws.length - 1) >= 0) {
3150	+	if (!found) {
3151	+	if ((System.nanoTime() - startTime) > nanos)
3152	+	return false;
3153	+	Thread.yield(); // cannot block
3154	+	}
3155	+	found = false;
3156	+	for (int j = (m + 1) << 2; j >= 0; --j) {
3157	+	ForkJoinTask<?> t; WorkQueue q; int b;
3158	+	if ((q = ws[r++ & m]) != null && (b = q.base) - q.top < 0) {
3159	+	found = true;
3160	+	if ((t = q.pollAt(b)) != null) {
3161	+	if (q.base - q.top < 0)
3162	+	signalWork(q);
3163	+	t.doExec();
3164	+	}
3165	+	break;
3166	+	}
3167	+	}
3168	+	}
3169	+	return true;
3170	+	}
3171	+
3172	+	/**
3173	+	* Waits and/or attempts to assist performing tasks indefinitely
3174	+	* until the {@link #commonPool()} {@link #isQuiescent}
3175	+	*/
3176	+	static void quiesceCommonPool() {
3177	+	common.awaitQuiescence(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
3178	+	}
3179	+
3180	+	/**
3181		* Interface for extending managed parallelism for tasks running
3182		* in {@link ForkJoinPool}s.
3183		*
#	Line 3339 | Line 3393 | public class ForkJoinPool extends Abstra
3393		par = Runtime.getRuntime().availableProcessors();
3394		if (par > MAX_CAP)
3395		par = MAX_CAP;
3396	<	commonPoolParallelism = par;
3396	>	commonParallelism = par;
3397		long np = (long)(-par); // precompute initial ctl value
3398		long ct = ((np << AC_SHIFT) & AC_MASK) | ((np << TC_SHIFT) & TC_MASK);
3399
3400	<	commonPool = new ForkJoinPool(par, ct, fac, handler);
3400	>	common = new ForkJoinPool(par, ct, fac, handler);
3401		}
3402
3349	–
3403		/**
3404		* Returns a sun.misc.Unsafe.  Suitable for use in a 3rd party package.
3405		* Replace with a simple call to Unsafe.getUnsafe when integrating
#	Line 3357 | Line 3410 | public class ForkJoinPool extends Abstra
3410		private static sun.misc.Unsafe getUnsafe() {
3411		try {
3412		return sun.misc.Unsafe.getUnsafe();
3413	<	} catch (SecurityException se) {
3414	<	try {
3415	<	return java.security.AccessController.doPrivileged
3416	<	(new java.security
3417	<	.PrivilegedExceptionAction<sun.misc.Unsafe>() {
3418	<	public sun.misc.Unsafe run() throws Exception {
3419	<	java.lang.reflect.Field f = sun.misc
3420	<	.Unsafe.class.getDeclaredField("theUnsafe");
3421	<	f.setAccessible(true);
3422	<	return (sun.misc.Unsafe) f.get(null);
3423	<	}});
3424	<	} catch (java.security.PrivilegedActionException e) {
3425	<	throw new RuntimeException("Could not initialize intrinsics",
3426	<	e.getCause());
3427	<	}
3413	>	} catch (SecurityException tryReflectionInstead) {}
3414	>	try {
3415	>	return java.security.AccessController.doPrivileged
3416	>	(new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() {
3417	>	public sun.misc.Unsafe run() throws Exception {
3418	>	Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
3419	>	for (java.lang.reflect.Field f : k.getDeclaredFields()) {
3420	>	f.setAccessible(true);
3421	>	Object x = f.get(null);
3422	>	if (k.isInstance(x))
3423	>	return k.cast(x);
3424	>	}
3425	>	throw new NoSuchFieldError("the Unsafe");
3426	>	}});
3427	>	} catch (java.security.PrivilegedActionException e) {
3428	>	throw new RuntimeException("Could not initialize intrinsics",
3429	>	e.getCause());
3430		}
3431		}
3377	–
3432		}

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