93 |
|
* performs the most common form of parallel invocation: forking a set |
94 |
|
* of tasks and joining them all. |
95 |
|
* |
96 |
< |
* <p>In the most typical usages, a fork-join pair act like a a call |
96 |
> |
* <p>In the most typical usages, a fork-join pair act like a call |
97 |
|
* (fork) and return (join) from a parallel recursive function. As is |
98 |
|
* the case with other forms of recursive calls, returns (joins) |
99 |
|
* should be performed innermost-first. For example, {@code a.fork(); |
137 |
|
* {@link Phaser}, {@link #helpQuiesce}, and {@link #complete}) that |
138 |
|
* may be of use in constructing custom subclasses for problems that |
139 |
|
* are not statically structured as DAGs. To support such usages a |
140 |
< |
* ForkJoinTask may be atomically <em>marked</em> using {@link |
141 |
< |
* #markForkJoinTask} and checked for marking using {@link |
142 |
< |
* #isMarkedForkJoinTask}. The ForkJoinTask implementation does not |
143 |
< |
* use these {@code protected} methods or marks for any purpose, but |
140 |
> |
* ForkJoinTask may be atomically <em>tagged</em> with a {@code |
141 |
> |
* short} value using {@link #setForkJoinTaskTag} or {@link |
142 |
> |
* #compareAndSetForkJoinTaskTag} and checked using {@link |
143 |
> |
* #getForkJoinTaskTag}. The ForkJoinTask implementation does not |
144 |
> |
* use these {@code protected} methods or tags for any purpose, but |
145 |
|
* they may be of use in the construction of specialized subclasses. |
146 |
|
* For example, parallel graph traversals can use the supplied methods |
147 |
< |
* to avoid revisiting nodes/tasks that have already been |
148 |
< |
* processed. Also, completion based designs can use them to record |
149 |
< |
* that one subtask has completed. (Method names for marking are bulky |
150 |
< |
* in part to encourage definition of methods that reflect their usage |
150 |
< |
* patterns.) |
147 |
> |
* to avoid revisiting nodes/tasks that have already been processed. |
148 |
> |
* Also, completion based designs can use them to record that subtasks |
149 |
> |
* have completed. (Method names for tagging are bulky in part to |
150 |
> |
* encourage definition of methods that reflect their usage patterns.) |
151 |
|
* |
152 |
|
* <p>Most base support methods are {@code final}, to prevent |
153 |
|
* overriding of implementations that are intrinsically tied to the |
197 |
|
* methods in a way that flows well in javadocs. |
198 |
|
*/ |
199 |
|
|
200 |
– |
/** |
201 |
– |
* The number of times to try to help join a task without any |
202 |
– |
* apparent progress before giving up and blocking. The value is |
203 |
– |
* arbitrary but should be large enough to cope with transient |
204 |
– |
* stalls (due to GC etc) that can cause helping methods not to be |
205 |
– |
* able to proceed because other workers have not progressed to |
206 |
– |
* the point where subtasks can be found or taken. |
207 |
– |
*/ |
208 |
– |
private static final int HELP_RETRIES = 32; |
209 |
– |
|
200 |
|
/* |
201 |
|
* The status field holds run control status bits packed into a |
202 |
|
* single int to minimize footprint and to ensure atomicity (via |
203 |
|
* CAS). Status is initially zero, and takes on nonnegative |
204 |
< |
* values until completed, upon which status holds value |
205 |
< |
* NORMAL, CANCELLED, or EXCEPTIONAL. Tasks undergoing blocking |
206 |
< |
* waits by other threads have the SIGNAL bit set. Completion of |
207 |
< |
* a stolen task with SIGNAL set awakens any waiters via |
208 |
< |
* notifyAll. Even though suboptimal for some purposes, we use |
209 |
< |
* basic builtin wait/notify to take advantage of "monitor |
210 |
< |
* inflation" in JVMs that we would otherwise need to emulate to |
211 |
< |
* avoid adding further per-task bookkeeping overhead. We want |
212 |
< |
* these monitors to be "fat", i.e., not use biasing or thin-lock |
213 |
< |
* techniques, so use some odd coding idioms that tend to avoid |
214 |
< |
* them. |
204 |
> |
* values until completed, upon which status (anded with |
205 |
> |
* DONE_MASK) holds value NORMAL, CANCELLED, or EXCEPTIONAL. Tasks |
206 |
> |
* undergoing blocking waits by other threads have the SIGNAL bit |
207 |
> |
* set. Completion of a stolen task with SIGNAL set awakens any |
208 |
> |
* waiters via notifyAll. Even though suboptimal for some |
209 |
> |
* purposes, we use basic builtin wait/notify to take advantage of |
210 |
> |
* "monitor inflation" in JVMs that we would otherwise need to |
211 |
> |
* emulate to avoid adding further per-task bookkeeping overhead. |
212 |
> |
* We want these monitors to be "fat", i.e., not use biasing or |
213 |
> |
* thin-lock techniques, so use some odd coding idioms that tend |
214 |
> |
* to avoid them, mainly by arranging that every synchronized |
215 |
> |
* block performs a wait, notifyAll or both. |
216 |
> |
* |
217 |
> |
* These control bits occupy only (some of) the upper half (16 |
218 |
> |
* bits) of status field. The lower bits are used for user-defined |
219 |
> |
* tags. |
220 |
|
*/ |
221 |
|
|
222 |
|
/** The run status of this task */ |
223 |
|
volatile int status; // accessed directly by pool and workers |
224 |
< |
static final int NORMAL = 0xfffffffc; // negative with low 2 bits 0 |
225 |
< |
static final int CANCELLED = 0xfffffff8; // must be < NORMAL |
226 |
< |
static final int EXCEPTIONAL = 0xfffffff4; // must be < CANCELLED |
227 |
< |
static final int SIGNAL = 0x00000001; |
228 |
< |
static final int MARKED = 0x00000002; |
224 |
> |
static final int DONE_MASK = 0xf0000000; // mask out non-completion bits |
225 |
> |
static final int NORMAL = 0xf0000000; // must be negative |
226 |
> |
static final int CANCELLED = 0xc0000000; // must be < NORMAL |
227 |
> |
static final int EXCEPTIONAL = 0x80000000; // must be < CANCELLED |
228 |
> |
static final int SIGNAL = 0x00010000; // must be >= 1 << 16 |
229 |
> |
static final int SMASK = 0x0000ffff; // short bits for tags |
230 |
|
|
231 |
|
/** |
232 |
|
* Marks completion and wakes up threads waiting to join this |
233 |
< |
* task, also clearing signal request bits. A specialization for |
238 |
< |
* NORMAL completion is in method doExec |
233 |
> |
* task. |
234 |
|
* |
235 |
|
* @param completion one of NORMAL, CANCELLED, EXCEPTIONAL |
236 |
|
* @return completion status on exit |
239 |
|
for (int s;;) { |
240 |
|
if ((s = status) < 0) |
241 |
|
return s; |
242 |
< |
if (U.compareAndSwapInt(this, STATUS, s, (s & ~SIGNAL)|completion)) { |
243 |
< |
if ((s & SIGNAL) != 0) |
242 |
> |
if (U.compareAndSwapInt(this, STATUS, s, s | completion)) { |
243 |
> |
if ((s >>> 16) != 0) |
244 |
|
synchronized (this) { notifyAll(); } |
245 |
|
return completion; |
246 |
|
} |
262 |
|
} catch (Throwable rex) { |
263 |
|
return setExceptionalCompletion(rex); |
264 |
|
} |
265 |
< |
while ((s = status) >= 0 && completed) { |
266 |
< |
if (U.compareAndSwapInt(this, STATUS, s, (s & ~SIGNAL)|NORMAL)) { |
272 |
< |
if ((s & SIGNAL) != 0) |
273 |
< |
synchronized (this) { notifyAll(); } |
274 |
< |
return NORMAL; |
275 |
< |
} |
276 |
< |
} |
265 |
> |
if (completed) |
266 |
> |
s = setCompletion(NORMAL); |
267 |
|
} |
268 |
|
return s; |
269 |
|
} |
270 |
|
|
271 |
|
/** |
272 |
+ |
* Tries to set SIGNAL status. Used by ForkJoinPool. Other |
273 |
+ |
* variants are directly incorporated into externalAwaitDone etc. |
274 |
+ |
* |
275 |
+ |
* @return true if successful |
276 |
+ |
*/ |
277 |
+ |
final boolean trySetSignal() { |
278 |
+ |
int s; |
279 |
+ |
return U.compareAndSwapInt(this, STATUS, s = status, s | SIGNAL); |
280 |
+ |
} |
281 |
+ |
|
282 |
+ |
/** |
283 |
|
* Blocks a non-worker-thread until completion. |
284 |
|
* @return status upon completion |
285 |
|
*/ |
286 |
|
private int externalAwaitDone() { |
287 |
+ |
boolean interrupted = false; |
288 |
|
int s; |
289 |
< |
if ((s = status) >= 0) { |
290 |
< |
boolean interrupted = false; |
291 |
< |
synchronized (this) { |
292 |
< |
while ((s = status) >= 0) { |
291 |
< |
if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) { |
289 |
> |
while ((s = status) >= 0) { |
290 |
> |
if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) { |
291 |
> |
synchronized (this) { |
292 |
> |
if (status >= 0) { |
293 |
|
try { |
294 |
|
wait(); |
295 |
|
} catch (InterruptedException ie) { |
296 |
|
interrupted = true; |
297 |
|
} |
298 |
|
} |
299 |
+ |
else |
300 |
+ |
notifyAll(); |
301 |
|
} |
302 |
|
} |
300 |
– |
if (interrupted) |
301 |
– |
Thread.currentThread().interrupt(); |
303 |
|
} |
304 |
+ |
if (interrupted) |
305 |
+ |
Thread.currentThread().interrupt(); |
306 |
|
return s; |
307 |
|
} |
308 |
|
|
309 |
|
/** |
310 |
< |
* Blocks a non-worker-thread until completion or interruption or timeout. |
310 |
> |
* Blocks a non-worker-thread until completion or interruption. |
311 |
|
*/ |
312 |
< |
private int externalInterruptibleAwaitDone(long millis) |
310 |
< |
throws InterruptedException { |
312 |
> |
private int externalInterruptibleAwaitDone() throws InterruptedException { |
313 |
|
int s; |
314 |
|
if (Thread.interrupted()) |
315 |
|
throw new InterruptedException(); |
316 |
< |
if ((s = status) >= 0) { |
317 |
< |
synchronized (this) { |
318 |
< |
while ((s = status) >= 0) { |
319 |
< |
if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) { |
320 |
< |
wait(millis); |
321 |
< |
if (millis > 0L) |
322 |
< |
break; |
321 |
< |
} |
316 |
> |
while ((s = status) >= 0) { |
317 |
> |
if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) { |
318 |
> |
synchronized (this) { |
319 |
> |
if (status >= 0) |
320 |
> |
wait(); |
321 |
> |
else |
322 |
> |
notifyAll(); |
323 |
|
} |
324 |
|
} |
325 |
|
} |
326 |
|
return s; |
327 |
|
} |
328 |
|
|
328 |
– |
|
329 |
|
/** |
330 |
|
* Implementation for join, get, quietlyJoin. Directly handles |
331 |
|
* only cases of already-completed, external wait, and |
332 |
< |
* unfork+exec. Others are relayed to awaitJoin. |
332 |
> |
* unfork+exec. Others are relayed to ForkJoinPool.awaitJoin. |
333 |
|
* |
334 |
|
* @return status upon completion |
335 |
|
*/ |
336 |
|
private int doJoin() { |
337 |
|
int s; Thread t; ForkJoinWorkerThread wt; ForkJoinPool.WorkQueue w; |
338 |
|
if ((s = status) >= 0) { |
339 |
< |
if (!((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)) |
340 |
< |
s = externalAwaitDone(); |
341 |
< |
else if (!(w = (wt = (ForkJoinWorkerThread)t).workQueue). |
342 |
< |
tryUnpush(this) || (s = doExec()) >= 0) |
343 |
< |
s = awaitJoin(w, wt.pool); |
344 |
< |
} |
345 |
< |
return s; |
346 |
< |
} |
347 |
< |
|
348 |
< |
/** |
349 |
< |
* Helps and/or blocks until joined. |
350 |
< |
* |
351 |
< |
* @param w the joiner |
352 |
< |
* @param p the pool |
353 |
< |
* @return status upon completion |
354 |
< |
*/ |
355 |
< |
private int awaitJoin(ForkJoinPool.WorkQueue w, ForkJoinPool p) { |
356 |
< |
int s; |
357 |
< |
ForkJoinTask<?> prevJoin = w.currentJoin; |
358 |
< |
w.currentJoin = this; |
359 |
< |
for (int k = HELP_RETRIES; (s = status) >= 0;) { |
360 |
< |
if ((w.queueSize() > 0) ? |
361 |
< |
w.tryRemoveAndExec(this) : // self-help |
362 |
< |
p.tryHelpStealer(w, this)) // help process tasks |
363 |
< |
k = HELP_RETRIES; // reset if made progress |
364 |
< |
else if ((s = status) < 0) // recheck |
365 |
< |
break; |
366 |
< |
else if (--k > 0) { |
367 |
< |
if ((k & 3) == 1) |
368 |
< |
Thread.yield(); // occasionally yield |
369 |
< |
} |
370 |
< |
else if (k == 0) |
371 |
< |
p.tryPollForAndExec(w, this); // uncommon self-help case |
372 |
< |
else if (p.tryCompensate()) { // true if can block |
373 |
< |
try { |
374 |
< |
int ss = status; |
375 |
< |
if (ss >= 0 && // assert need signal |
376 |
< |
U.compareAndSwapInt(this, STATUS, ss, ss | SIGNAL)) { |
377 |
< |
synchronized (this) { |
378 |
< |
if (status >= 0) // block |
379 |
< |
wait(); |
380 |
< |
} |
381 |
< |
} |
382 |
< |
} catch (InterruptedException ignore) { |
383 |
< |
} finally { |
384 |
< |
p.incrementActiveCount(); // re-activate |
385 |
< |
} |
339 |
> |
if (((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)) { |
340 |
> |
if (!(w = (wt = (ForkJoinWorkerThread)t).workQueue). |
341 |
> |
tryUnpush(this) || (s = doExec()) >= 0) |
342 |
> |
s = wt.pool.awaitJoin(w, this); |
343 |
|
} |
344 |
+ |
else |
345 |
+ |
s = externalAwaitDone(); |
346 |
|
} |
388 |
– |
w.currentJoin = prevJoin; |
347 |
|
return s; |
348 |
|
} |
349 |
|
|
353 |
|
* @return status upon completion |
354 |
|
*/ |
355 |
|
private int doInvoke() { |
356 |
< |
int s; Thread t; |
356 |
> |
int s; Thread t; ForkJoinWorkerThread wt; |
357 |
|
if ((s = doExec()) >= 0) { |
358 |
< |
if (!((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)) |
358 |
> |
if ((t = Thread.currentThread()) instanceof ForkJoinWorkerThread) |
359 |
> |
s = (wt = (ForkJoinWorkerThread)t).pool.awaitJoin(wt.workQueue, |
360 |
> |
this); |
361 |
> |
else |
362 |
|
s = externalAwaitDone(); |
402 |
– |
else { |
403 |
– |
ForkJoinWorkerThread wt = (ForkJoinWorkerThread)t; |
404 |
– |
s = awaitJoin(wt.workQueue, wt.pool); |
405 |
– |
} |
363 |
|
} |
364 |
|
return s; |
365 |
|
} |
396 |
|
* any ForkJoinPool will call helpExpungeStaleExceptions when its |
397 |
|
* pool becomes isQuiescent. |
398 |
|
*/ |
399 |
< |
static final class ExceptionNode extends WeakReference<ForkJoinTask<?>>{ |
399 |
> |
static final class ExceptionNode extends WeakReference<ForkJoinTask<?>> { |
400 |
|
final Throwable ex; |
401 |
|
ExceptionNode next; |
402 |
|
final long thrower; // use id not ref to avoid weak cycles |
496 |
|
* @return the exception, or null if none |
497 |
|
*/ |
498 |
|
private Throwable getThrowableException() { |
499 |
< |
if (status != EXCEPTIONAL) |
499 |
> |
if ((status & DONE_MASK) != EXCEPTIONAL) |
500 |
|
return null; |
501 |
|
int h = System.identityHashCode(this); |
502 |
|
ExceptionNode e; |
581 |
|
} |
582 |
|
|
583 |
|
/** |
584 |
< |
* Report the result of invoke or join; called only upon |
628 |
< |
* non-normal return of internal versions. |
584 |
> |
* Throws exception, if any, associated with the given status. |
585 |
|
*/ |
586 |
< |
private V reportResult() { |
587 |
< |
int s; Throwable ex; |
588 |
< |
if ((s = status) == CANCELLED) |
589 |
< |
throw new CancellationException(); |
590 |
< |
if (s == EXCEPTIONAL && (ex = getThrowableException()) != null) |
586 |
> |
private void reportException(int s) { |
587 |
> |
Throwable ex = ((s == CANCELLED) ? new CancellationException() : |
588 |
> |
(s == EXCEPTIONAL) ? getThrowableException() : |
589 |
> |
null); |
590 |
> |
if (ex != null) |
591 |
|
U.throwException(ex); |
636 |
– |
return getRawResult(); |
592 |
|
} |
593 |
|
|
594 |
|
// public methods |
612 |
|
* @return {@code this}, to simplify usage |
613 |
|
*/ |
614 |
|
public final ForkJoinTask<V> fork() { |
615 |
< |
ForkJoinWorkerThread wt; |
661 |
< |
(wt = (ForkJoinWorkerThread)Thread.currentThread()). |
662 |
< |
workQueue.push(this, wt.pool); |
615 |
> |
((ForkJoinWorkerThread)Thread.currentThread()).workQueue.push(this); |
616 |
|
return this; |
617 |
|
} |
618 |
|
|
628 |
|
* @return the computed result |
629 |
|
*/ |
630 |
|
public final V join() { |
631 |
< |
if (doJoin() != NORMAL) |
632 |
< |
return reportResult(); |
633 |
< |
else |
634 |
< |
return getRawResult(); |
631 |
> |
int s; |
632 |
> |
if ((s = doJoin() & DONE_MASK) != NORMAL) |
633 |
> |
reportException(s); |
634 |
> |
return getRawResult(); |
635 |
|
} |
636 |
|
|
637 |
|
/** |
643 |
|
* @return the computed result |
644 |
|
*/ |
645 |
|
public final V invoke() { |
646 |
< |
if (doInvoke() != NORMAL) |
647 |
< |
return reportResult(); |
648 |
< |
else |
649 |
< |
return getRawResult(); |
646 |
> |
int s; |
647 |
> |
if ((s = doInvoke() & DONE_MASK) != NORMAL) |
648 |
> |
reportException(s); |
649 |
> |
return getRawResult(); |
650 |
|
} |
651 |
|
|
652 |
|
/** |
673 |
|
* @throws NullPointerException if any task is null |
674 |
|
*/ |
675 |
|
public static void invokeAll(ForkJoinTask<?> t1, ForkJoinTask<?> t2) { |
676 |
+ |
int s1, s2; |
677 |
|
t2.fork(); |
678 |
< |
t1.invoke(); |
679 |
< |
t2.join(); |
678 |
> |
if ((s1 = t1.doInvoke() & DONE_MASK) != NORMAL) |
679 |
> |
t1.reportException(s1); |
680 |
> |
if ((s2 = t2.doJoin() & DONE_MASK) != NORMAL) |
681 |
> |
t2.reportException(s2); |
682 |
|
} |
683 |
|
|
684 |
|
/** |
815 |
|
* @return {@code true} if this task is now cancelled |
816 |
|
*/ |
817 |
|
public boolean cancel(boolean mayInterruptIfRunning) { |
818 |
< |
return setCompletion(CANCELLED) == CANCELLED; |
818 |
> |
return (setCompletion(CANCELLED) & DONE_MASK) == CANCELLED; |
819 |
|
} |
820 |
|
|
821 |
|
public final boolean isDone() { |
823 |
|
} |
824 |
|
|
825 |
|
public final boolean isCancelled() { |
826 |
< |
return status == CANCELLED; |
826 |
> |
return (status & DONE_MASK) == CANCELLED; |
827 |
|
} |
828 |
|
|
829 |
|
/** |
843 |
|
* exception and was not cancelled |
844 |
|
*/ |
845 |
|
public final boolean isCompletedNormally() { |
846 |
< |
return status == NORMAL; |
846 |
> |
return (status & DONE_MASK) == NORMAL; |
847 |
|
} |
848 |
|
|
849 |
|
/** |
854 |
|
* @return the exception, or {@code null} if none |
855 |
|
*/ |
856 |
|
public final Throwable getException() { |
857 |
< |
int s = status; |
857 |
> |
int s = status & DONE_MASK; |
858 |
|
return ((s >= NORMAL) ? null : |
859 |
|
(s == CANCELLED) ? new CancellationException() : |
860 |
|
getThrowableException()); |
904 |
|
} |
905 |
|
|
906 |
|
/** |
907 |
+ |
* Completes this task. The most recent value established by |
908 |
+ |
* {@link #setRawResult} (or {@code null}) will be returned as the |
909 |
+ |
* result of subsequent invocations of {@code join} and related |
910 |
+ |
* operations. This method may be useful when processing sets of |
911 |
+ |
* tasks when some do not otherwise complete normally. Its use in |
912 |
+ |
* other situations is discouraged. |
913 |
+ |
*/ |
914 |
+ |
public final void quietlyComplete() { |
915 |
+ |
setCompletion(NORMAL); |
916 |
+ |
} |
917 |
+ |
|
918 |
+ |
/** |
919 |
|
* Waits if necessary for the computation to complete, and then |
920 |
|
* retrieves its result. |
921 |
|
* |
928 |
|
*/ |
929 |
|
public final V get() throws InterruptedException, ExecutionException { |
930 |
|
int s = (Thread.currentThread() instanceof ForkJoinWorkerThread) ? |
931 |
< |
doJoin() : externalInterruptibleAwaitDone(0L); |
931 |
> |
doJoin() : externalInterruptibleAwaitDone(); |
932 |
|
Throwable ex; |
933 |
< |
if (s == CANCELLED) |
933 |
> |
if ((s &= DONE_MASK) == CANCELLED) |
934 |
|
throw new CancellationException(); |
935 |
|
if (s == EXCEPTIONAL && (ex = getThrowableException()) != null) |
936 |
|
throw new ExecutionException(ex); |
953 |
|
*/ |
954 |
|
public final V get(long timeout, TimeUnit unit) |
955 |
|
throws InterruptedException, ExecutionException, TimeoutException { |
956 |
< |
// Messy in part because we measure in nanos, but wait in millis |
957 |
< |
int s; long millis, nanos; |
958 |
< |
Thread t = Thread.currentThread(); |
959 |
< |
if (!(t instanceof ForkJoinWorkerThread)) { |
960 |
< |
if ((millis = unit.toMillis(timeout)) > 0L) |
961 |
< |
s = externalInterruptibleAwaitDone(millis); |
962 |
< |
else |
963 |
< |
s = status; |
964 |
< |
} |
965 |
< |
else if ((s = status) >= 0 && (nanos = unit.toNanos(timeout)) > 0L) { |
966 |
< |
long deadline = System.nanoTime() + nanos; |
967 |
< |
ForkJoinWorkerThread wt = (ForkJoinWorkerThread)t; |
968 |
< |
ForkJoinPool.WorkQueue w = wt.workQueue; |
969 |
< |
ForkJoinPool p = wt.pool; |
970 |
< |
if (w.tryUnpush(this)) |
971 |
< |
doExec(); |
972 |
< |
boolean blocking = false; |
956 |
> |
if (Thread.interrupted()) |
957 |
> |
throw new InterruptedException(); |
958 |
> |
// Messy in part because we measure in nanosecs, but wait in millisecs |
959 |
> |
int s; long ns, ms; |
960 |
> |
if ((s = status) >= 0 && (ns = unit.toNanos(timeout)) > 0L) { |
961 |
> |
long deadline = System.nanoTime() + ns; |
962 |
> |
ForkJoinPool p = null; |
963 |
> |
ForkJoinPool.WorkQueue w = null; |
964 |
> |
Thread t = Thread.currentThread(); |
965 |
> |
if (t instanceof ForkJoinWorkerThread) { |
966 |
> |
ForkJoinWorkerThread wt = (ForkJoinWorkerThread)t; |
967 |
> |
p = wt.pool; |
968 |
> |
w = wt.workQueue; |
969 |
> |
s = p.helpJoinOnce(w, this); // no retries on failure |
970 |
> |
} |
971 |
> |
boolean canBlock = false; |
972 |
> |
boolean interrupted = false; |
973 |
|
try { |
974 |
|
while ((s = status) >= 0) { |
975 |
< |
if (w.runState < 0) |
975 |
> |
if (w != null && w.runState < 0) |
976 |
|
cancelIgnoringExceptions(this); |
977 |
< |
else if (!blocking) |
978 |
< |
blocking = p.tryCompensate(); |
977 |
> |
else if (!canBlock) { |
978 |
> |
if (p == null || p.tryCompensate(this, null)) |
979 |
> |
canBlock = true; |
980 |
> |
} |
981 |
|
else { |
982 |
< |
millis = TimeUnit.NANOSECONDS.toMillis(nanos); |
1013 |
< |
if (millis > 0L && |
982 |
> |
if ((ms = TimeUnit.NANOSECONDS.toMillis(ns)) > 0L && |
983 |
|
U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) { |
984 |
< |
try { |
985 |
< |
synchronized (this) { |
986 |
< |
if (status >= 0) |
987 |
< |
wait(millis); |
984 |
> |
synchronized (this) { |
985 |
> |
if (status >= 0) { |
986 |
> |
try { |
987 |
> |
wait(ms); |
988 |
> |
} catch (InterruptedException ie) { |
989 |
> |
if (p == null) |
990 |
> |
interrupted = true; |
991 |
> |
} |
992 |
|
} |
993 |
< |
} catch (InterruptedException ie) { |
993 |
> |
else |
994 |
> |
notifyAll(); |
995 |
|
} |
996 |
|
} |
997 |
< |
if ((s = status) < 0 || |
998 |
< |
(nanos = deadline - System.nanoTime()) <= 0L) |
997 |
> |
if ((s = status) < 0 || interrupted || |
998 |
> |
(ns = deadline - System.nanoTime()) <= 0L) |
999 |
|
break; |
1000 |
|
} |
1001 |
|
} |
1002 |
|
} finally { |
1003 |
< |
if (blocking) |
1003 |
> |
if (p != null && canBlock) |
1004 |
|
p.incrementActiveCount(); |
1005 |
|
} |
1006 |
+ |
if (interrupted) |
1007 |
+ |
throw new InterruptedException(); |
1008 |
|
} |
1009 |
< |
if (s != NORMAL) { |
1009 |
> |
if ((s &= DONE_MASK) != NORMAL) { |
1010 |
|
Throwable ex; |
1011 |
|
if (s == CANCELLED) |
1012 |
|
throw new CancellationException(); |
1073 |
|
* setRawResult(null)}. |
1074 |
|
*/ |
1075 |
|
public void reinitialize() { |
1076 |
< |
if (status == EXCEPTIONAL) |
1076 |
> |
if ((status & DONE_MASK) == EXCEPTIONAL) |
1077 |
|
clearExceptionalCompletion(); |
1078 |
|
else |
1079 |
|
status = 0; |
1311 |
|
return wt.pool.nextTaskFor(wt.workQueue); |
1312 |
|
} |
1313 |
|
|
1314 |
< |
// Mark-bit operations |
1314 |
> |
// tag operations |
1315 |
|
|
1316 |
|
/** |
1317 |
< |
* Returns true if this task is marked. |
1317 |
> |
* Returns the tag for this task. |
1318 |
|
* |
1319 |
< |
* @return true if this task is marked |
1319 |
> |
* @return the tag for this task |
1320 |
|
* @since 1.8 |
1321 |
|
*/ |
1322 |
< |
public final boolean isMarkedForkJoinTask() { |
1323 |
< |
return (status & MARKED) != 0; |
1322 |
> |
public final short getForkJoinTaskTag() { |
1323 |
> |
return (short)status; |
1324 |
|
} |
1325 |
|
|
1326 |
|
/** |
1327 |
< |
* Atomically sets the mark on this task. |
1327 |
> |
* Atomically sets the tag value for this task. |
1328 |
|
* |
1329 |
< |
* @return true if this task was previously unmarked |
1329 |
> |
* @param tag the tag value |
1330 |
> |
* @return the previous value of the tag |
1331 |
|
* @since 1.8 |
1332 |
|
*/ |
1333 |
< |
public final boolean markForkJoinTask() { |
1333 |
> |
public final short setForkJoinTaskTag(short tag) { |
1334 |
|
for (int s;;) { |
1335 |
< |
if (((s = status) & MARKED) != 0) |
1336 |
< |
return false; |
1337 |
< |
if (U.compareAndSwapInt(this, STATUS, s, s | MARKED)) |
1361 |
< |
return true; |
1335 |
> |
if (U.compareAndSwapInt(this, STATUS, s = status, |
1336 |
> |
(s & ~SMASK) | (tag & SMASK))) |
1337 |
> |
return (short)s; |
1338 |
|
} |
1339 |
|
} |
1340 |
|
|
1341 |
|
/** |
1342 |
< |
* Atomically clears the mark on this task. |
1342 |
> |
* Atomically conditionally sets the tag value for this task. |
1343 |
> |
* Among other applications, tags can be used as visit markers |
1344 |
> |
* in tasks operating on graphs, as in methods that check: {@code |
1345 |
> |
* if (task.compareAndSetForkJoinTaskTag((short)0, (short)1))} |
1346 |
> |
* before processing, otherwise exiting because the node has |
1347 |
> |
* already been visited. |
1348 |
|
* |
1349 |
< |
* @return true if this task was previously marked |
1349 |
> |
* @param e the expected tag value |
1350 |
> |
* @param tag the new tag value |
1351 |
> |
* @return true if successful; i.e., the current value was |
1352 |
> |
* equal to e and is now tag. |
1353 |
|
* @since 1.8 |
1354 |
|
*/ |
1355 |
< |
public final boolean unmarkForkJoinTask() { |
1355 |
> |
public final boolean compareAndSetForkJoinTaskTag(short e, short tag) { |
1356 |
|
for (int s;;) { |
1357 |
< |
if (((s = status) & MARKED) == 0) |
1357 |
> |
if ((short)(s = status) != e) |
1358 |
|
return false; |
1359 |
< |
if (U.compareAndSwapInt(this, STATUS, s, s & ~MARKED)) |
1359 |
> |
if (U.compareAndSwapInt(this, STATUS, s, |
1360 |
> |
(s & ~SMASK) | (tag & SMASK))) |
1361 |
|
return true; |
1362 |
|
} |
1363 |
|
} |
1370 |
|
static final class AdaptedRunnable<T> extends ForkJoinTask<T> |
1371 |
|
implements RunnableFuture<T> { |
1372 |
|
final Runnable runnable; |
1388 |
– |
final T resultOnCompletion; |
1373 |
|
T result; |
1374 |
|
AdaptedRunnable(Runnable runnable, T result) { |
1375 |
|
if (runnable == null) throw new NullPointerException(); |
1376 |
|
this.runnable = runnable; |
1377 |
< |
this.resultOnCompletion = result; |
1377 |
> |
this.result = result; // OK to set this even before completion |
1378 |
|
} |
1379 |
< |
public T getRawResult() { return result; } |
1380 |
< |
public void setRawResult(T v) { result = v; } |
1381 |
< |
public boolean exec() { |
1382 |
< |
runnable.run(); |
1383 |
< |
result = resultOnCompletion; |
1384 |
< |
return true; |
1379 |
> |
public final T getRawResult() { return result; } |
1380 |
> |
public final void setRawResult(T v) { result = v; } |
1381 |
> |
public final boolean exec() { runnable.run(); return true; } |
1382 |
> |
public final void run() { invoke(); } |
1383 |
> |
private static final long serialVersionUID = 5232453952276885070L; |
1384 |
> |
} |
1385 |
> |
|
1386 |
> |
/** |
1387 |
> |
* Adaptor for Runnables without results |
1388 |
> |
*/ |
1389 |
> |
static final class AdaptedRunnableAction extends ForkJoinTask<Void> |
1390 |
> |
implements RunnableFuture<Void> { |
1391 |
> |
final Runnable runnable; |
1392 |
> |
AdaptedRunnableAction(Runnable runnable) { |
1393 |
> |
if (runnable == null) throw new NullPointerException(); |
1394 |
> |
this.runnable = runnable; |
1395 |
|
} |
1396 |
< |
public void run() { invoke(); } |
1396 |
> |
public final Void getRawResult() { return null; } |
1397 |
> |
public final void setRawResult(Void v) { } |
1398 |
> |
public final boolean exec() { runnable.run(); return true; } |
1399 |
> |
public final void run() { invoke(); } |
1400 |
|
private static final long serialVersionUID = 5232453952276885070L; |
1401 |
|
} |
1402 |
|
|
1411 |
|
if (callable == null) throw new NullPointerException(); |
1412 |
|
this.callable = callable; |
1413 |
|
} |
1414 |
< |
public T getRawResult() { return result; } |
1415 |
< |
public void setRawResult(T v) { result = v; } |
1416 |
< |
public boolean exec() { |
1414 |
> |
public final T getRawResult() { return result; } |
1415 |
> |
public final void setRawResult(T v) { result = v; } |
1416 |
> |
public final boolean exec() { |
1417 |
|
try { |
1418 |
|
result = callable.call(); |
1419 |
|
return true; |
1425 |
|
throw new RuntimeException(ex); |
1426 |
|
} |
1427 |
|
} |
1428 |
< |
public void run() { invoke(); } |
1428 |
> |
public final void run() { invoke(); } |
1429 |
|
private static final long serialVersionUID = 2838392045355241008L; |
1430 |
|
} |
1431 |
|
|
1438 |
|
* @return the task |
1439 |
|
*/ |
1440 |
|
public static ForkJoinTask<?> adapt(Runnable runnable) { |
1441 |
< |
return new AdaptedRunnable<Void>(runnable, null); |
1441 |
> |
return new AdaptedRunnableAction(runnable); |
1442 |
|
} |
1443 |
|
|
1444 |
|
/** |