ViewVC Help

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

root/jsr166/jsr166/src/jsr166y/ForkJoinTask.java

Comparing jsr166/src/jsr166y/ForkJoinTask.java (file contents):
Revision 1.52 by dl, Sat Jul 24 20:28:18 2010 UTC vs.
Revision 1.53 by dl, Wed Aug 11 18:45:12 2010 UTC

#	Line 144 | Line 144 | public abstract class ForkJoinTask<V> im
144		* status maintenance (2) execution and awaiting completion (3)
145		* user-level methods that additionally report results. This is
146		* sometimes hard to see because this file orders exported methods
147	<	* in a way that flows well in javadocs.
147	>	* in a way that flows well in javadocs. In particular, most
148	>	* join mechanics are in method quietlyJoin, below.
149		*/
150
151		/*
#	Line 164 | Line 165 | public abstract class ForkJoinTask<V> im
165		* them.
166		*/
167
168	<	/** Run status of this task */
168	>	/** The run status of this task */
169		volatile int status; // accessed directly by pool and workers
170
171		private static final int NORMAL      = -1;
#	Line 191 | Line 192 | public abstract class ForkJoinTask<V> im
192		* also clearing signal request bits.
193		*
194		* @param completion one of NORMAL, CANCELLED, EXCEPTIONAL
194	–	* @return status on exit
195		*/
196	<	private int setCompletion(int completion) {
196	>	private void setCompletion(int completion) {
197		int s;
198		while ((s = status) >= 0) {
199		if (UNSAFE.compareAndSwapInt(this, statusOffset, s, completion)) {
200		if (s != 0)
201		synchronized (this) { notifyAll(); }
202	<	return completion;
202	>	break;
203		}
204		}
205	–	return s;
205		}
206
207		/**
208		* Record exception and set exceptional completion
209		* @return status on exit
210		*/
211	<	private int setExceptionalCompletion(Throwable rex) {
211	>	private void setExceptionalCompletion(Throwable rex) {
212		exceptionMap.put(this, rex);
213	<	return setCompletion(EXCEPTIONAL);
213	>	setCompletion(EXCEPTIONAL);
214		}
215
216		/**
#	Line 233 | Line 232 | public abstract class ForkJoinTask<V> im
232
233		/**
234		* Blocks a non-worker-thread until completion.
236	–	* @return status on exit
235		*/
236	<	private int externalAwaitDone() {
236	>	private void externalAwaitDone() {
237		int s;
238		while ((s = status) >= 0) {
239		synchronized(this) {
240		if (UNSAFE.compareAndSwapInt(this, statusOffset, s, SIGNAL)){
241		boolean interrupted = false;
242	<	while ((s = status) >= 0) {
242	>	while (status >= 0) {
243		try {
244		wait();
245		} catch (InterruptedException ie) {
#	Line 254 | Line 252 | public abstract class ForkJoinTask<V> im
252		}
253		}
254		}
257	–	return s;
255		}
256
257		/**
#	Line 262 | Line 259 | public abstract class ForkJoinTask<V> im
259		* doesn't wait for completion otherwise. Primary execution method
260		* for ForkJoinWorkerThread.
261		*/
262	<	final void tryExec() {
262	>	final void quietlyExec() {
263		try {
264		if (status < 0 || !exec())
265		return;
#	Line 273 | Line 270 | public abstract class ForkJoinTask<V> im
270		setCompletion(NORMAL); // must be outside try block
271		}
272
276	–	/**
277	–	* If not done and this task is next in worker queue, runs it,
278	–	* else waits for it.
279	–	* @return status on exit
280	–	*/
281	–	private int doJoin() {
282	–	int stat;
283	–	Thread t;
284	–	ForkJoinWorkerThread w;
285	–	if ((t = Thread.currentThread()) instanceof ForkJoinWorkerThread) {
286	–	if ((stat = status) < 0)
287	–	return stat;
288	–	if ((w = (ForkJoinWorkerThread) t).unpushTask(this)) {
289	–	boolean completed;
290	–	try {
291	–	completed = exec();
292	–	} catch (Throwable rex) {
293	–	return setExceptionalCompletion(rex);
294	–	}
295	–	if (completed)
296	–	return setCompletion(NORMAL);
297	–	}
298	–	return w.joinTask(this);
299	–	}
300	–	return externalAwaitDone();
301	–	}
302	–
303	–	/**
304	–	* Unless done, calls exec and records status if completed, or
305	–	* waits for completion otherwise.
306	–	* @return status on exit
307	–	*/
308	–	private int doInvoke() {
309	–	int stat;
310	–	if ((stat = status) >= 0) {
311	–	boolean completed;
312	–	try {
313	–	completed = exec();
314	–	} catch (Throwable rex) {
315	–	return setExceptionalCompletion(rex);
316	–	}
317	–	stat = completed ? setCompletion(NORMAL) : doJoin();
318	–	}
319	–	return stat;
320	–	}
321	–
322	–	/**
323	–	* Returns result or throws exception associated with given status.
324	–	* @param s the status
325	–	*/
326	–	private V reportResult(int s) {
327	–	Throwable ex;
328	–	if (s < NORMAL && (ex = getException()) != null)
329	–	UNSAFE.throwException(ex);
330	–	return getRawResult();
331	–	}
332	–
273		// public methods
274
275		/**
#	Line 365 | Line 305 | public abstract class ForkJoinTask<V> im
305		* @return the computed result
306		*/
307		public final V join() {
308	<	return reportResult(doJoin());
308	>	quietlyJoin();
309	>	Throwable ex;
310	>	if (status < NORMAL && (ex = getException()) != null)
311	>	UNSAFE.throwException(ex);
312	>	return getRawResult();
313		}
314
315		/**
#	Line 376 | Line 320 | public abstract class ForkJoinTask<V> im
320		* @return the computed result
321		*/
322		public final V invoke() {
323	<	return reportResult(doInvoke());
323	>	quietlyInvoke();
324	>	Throwable ex;
325	>	if (status < NORMAL && (ex = getException()) != null)
326	>	UNSAFE.throwException(ex);
327	>	return getRawResult();
328		}
329
330		/**
#	Line 434 | Line 382 | public abstract class ForkJoinTask<V> im
382		}
383		else if (i != 0)
384		t.fork();
385	<	else if (t.doInvoke() < NORMAL && ex == null)
386	<	ex = t.getException();
385	>	else {
386	>	t.quietlyInvoke();
387	>	if (ex == null && t.status < NORMAL)
388	>	ex = t.getException();
389	>	}
390		}
391		for (int i = 1; i <= last; ++i) {
392		ForkJoinTask<?> t = tasks[i];
393		if (t != null) {
394		if (ex != null)
395		t.cancel(false);
396	<	else if (t.doJoin() < NORMAL && ex == null)
397	<	ex = t.getException();
396	>	else {
397	>	t.quietlyJoin();
398	>	if (ex == null && t.status < NORMAL)
399	>	ex = t.getException();
400	>	}
401		}
402		}
403		if (ex != null)
#	Line 490 | Line 444 | public abstract class ForkJoinTask<V> im
444		}
445		else if (i != 0)
446		t.fork();
447	<	else if (t.doInvoke() < NORMAL && ex == null)
448	<	ex = t.getException();
447	>	else {
448	>	t.quietlyInvoke();
449	>	if (ex == null && t.status < NORMAL)
450	>	ex = t.getException();
451	>	}
452		}
453		for (int i = 1; i <= last; ++i) {
454		ForkJoinTask<?> t = ts.get(i);
455		if (t != null) {
456		if (ex != null)
457		t.cancel(false);
458	<	else if (t.doJoin() < NORMAL && ex == null)
459	<	ex = t.getException();
458	>	else {
459	>	t.quietlyJoin();
460	>	if (ex == null && t.status < NORMAL)
461	>	ex = t.getException();
462	>	}
463		}
464		}
465		if (ex != null)
#	Line 532 | Line 492 | public abstract class ForkJoinTask<V> im
492		* @return {@code true} if this task is now cancelled
493		*/
494		public boolean cancel(boolean mayInterruptIfRunning) {
495	<	return setCompletion(CANCELLED) == CANCELLED;
495	>	setCompletion(CANCELLED);
496	>	return status == CANCELLED;
497		}
498
499		/**
#	Line 647 | Line 608 | public abstract class ForkJoinTask<V> im
608		}
609
610		public final V get() throws InterruptedException, ExecutionException {
611	<	int s = doJoin();
611	>	quietlyJoin();
612		if (Thread.interrupted())
613		throw new InterruptedException();
614	+	int s = status;
615		if (s < NORMAL) {
616		Throwable ex;
617		if (s == CANCELLED)
#	Line 667 | Line 629 | public abstract class ForkJoinTask<V> im
629		if (t instanceof ForkJoinWorkerThread) {
630		ForkJoinWorkerThread w = (ForkJoinWorkerThread) t;
631		if (status >= 0 && w.unpushTask(this))
632	<	tryExec();
632	>	quietlyExec();
633		pool = w.pool;
634		}
635		else
#	Line 735 | Line 697 | public abstract class ForkJoinTask<V> im
697		}
698
699		/**
700	<	* Joins this task, without returning its result or throwing an
700	>	* Joins this task, without returning its result or throwing its
701		* exception. This method may be useful when processing
702		* collections of tasks when some have been cancelled or otherwise
703		* known to have aborted.
704		*/
705		public final void quietlyJoin() {
706	<	doJoin();
706	>	Thread t;
707	>	if ((t = Thread.currentThread()) instanceof ForkJoinWorkerThread) {
708	>	ForkJoinWorkerThread w = (ForkJoinWorkerThread) t;
709	>	if (status >= 0) {
710	>	if (w.unpushTask(this)) {
711	>	boolean completed;
712	>	try {
713	>	completed = exec();
714	>	} catch (Throwable rex) {
715	>	setExceptionalCompletion(rex);
716	>	return;
717	>	}
718	>	if (completed) {
719	>	setCompletion(NORMAL);
720	>	return;
721	>	}
722	>	}
723	>	w.joinTask(this);
724	>	}
725	>	}
726	>	else
727	>	externalAwaitDone();
728		}
729
730		/**
731		* Commences performing this task and awaits its completion if
732	<	* necessary, without returning its result or throwing an
732	>	* necessary, without returning its result or throwing its
733		* exception. This method may be useful when processing
734		* collections of tasks when some have been cancelled or otherwise
735		* known to have aborted.
736		*/
737		public final void quietlyInvoke() {
738	<	doInvoke();
738	>	if (status >= 0) {
739	>	boolean completed;
740	>	try {
741	>	completed = exec();
742	>	} catch (Throwable rex) {
743	>	setExceptionalCompletion(rex);
744	>	return;
745	>	}
746	>	if (completed)
747	>	setCompletion(NORMAL);
748	>	else
749	>	quietlyJoin();
750	>	}
751		}
752
753		/**

Diff Legend

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