5 |
|
*/ |
6 |
|
|
7 |
|
package jsr166y; |
8 |
< |
import java.io.Serializable; |
9 |
< |
import java.util.*; |
8 |
> |
|
9 |
|
import java.util.concurrent.*; |
10 |
< |
import java.util.concurrent.atomic.*; |
11 |
< |
import sun.misc.Unsafe; |
12 |
< |
import java.lang.reflect.*; |
10 |
> |
|
11 |
> |
import java.io.Serializable; |
12 |
> |
import java.util.Collection; |
13 |
> |
import java.util.Collections; |
14 |
> |
import java.util.List; |
15 |
> |
import java.util.Map; |
16 |
> |
import java.util.WeakHashMap; |
17 |
|
|
18 |
|
/** |
19 |
|
* Abstract base class for tasks that run within a {@link |
25 |
|
* <p> A "main" ForkJoinTask begins execution when submitted to a |
26 |
|
* {@link ForkJoinPool}. Once started, it will usually in turn start |
27 |
|
* other subtasks. As indicated by the name of this class, many |
28 |
< |
* programs using ForkJoinTasks employ only methods {@code fork} |
29 |
< |
* and {@code join}, or derivatives such as |
30 |
< |
* {@code invokeAll}. However, this class also provides a number |
31 |
< |
* of other methods that can come into play in advanced usages, as |
32 |
< |
* well as extension mechanics that allow support of new forms of |
30 |
< |
* fork/join processing. |
28 |
> |
* programs using ForkJoinTasks employ only methods {@code fork} and |
29 |
> |
* {@code join}, or derivatives such as {@code invokeAll}. However, |
30 |
> |
* this class also provides a number of other methods that can come |
31 |
> |
* into play in advanced usages, as well as extension mechanics that |
32 |
> |
* allow support of new forms of fork/join processing. |
33 |
|
* |
34 |
|
* <p>A ForkJoinTask is a lightweight form of {@link Future}. The |
35 |
|
* efficiency of ForkJoinTasks stems from a set of restrictions (that |
83 |
|
* class. While these methods have {@code public} access (to allow |
84 |
|
* instances of different task subclasses to call each others |
85 |
|
* methods), some of them may only be called from within other |
86 |
< |
* ForkJoinTasks. Attempts to invoke them in other contexts result in |
87 |
< |
* exceptions or errors possibly including ClassCastException. |
86 |
> |
* ForkJoinTasks (as may be determined using method {@link |
87 |
> |
* #inForkJoinPool}). Attempts to invoke them in other contexts |
88 |
> |
* result in exceptions or errors, possibly including |
89 |
> |
* ClassCastException. |
90 |
|
* |
91 |
|
* <p>Most base support methods are {@code final} because their |
92 |
|
* implementations are intrinsically tied to the underlying |
93 |
|
* lightweight task scheduling framework, and so cannot be overridden. |
94 |
|
* Developers creating new basic styles of fork/join processing should |
95 |
|
* minimally implement {@code protected} methods |
96 |
< |
* {@code exec}, {@code setRawResult}, and |
97 |
< |
* {@code getRawResult}, while also introducing an abstract |
96 |
> |
* {@link #exec}, {@link #setRawResult}, and |
97 |
> |
* {@link #getRawResult}, while also introducing an abstract |
98 |
|
* computational method that can be implemented in its subclasses, |
99 |
|
* possibly relying on other {@code protected} methods provided |
100 |
|
* by this class. |
164 |
|
*/ |
165 |
|
static ForkJoinWorkerThread getWorker() { |
166 |
|
Thread t = Thread.currentThread(); |
167 |
< |
return ((t instanceof ForkJoinWorkerThread)? |
168 |
< |
(ForkJoinWorkerThread)t : null); |
167 |
> |
return ((t instanceof ForkJoinWorkerThread) ? |
168 |
> |
(ForkJoinWorkerThread) t : null); |
169 |
|
} |
170 |
|
|
171 |
|
final boolean casStatus(int cmp, int val) { |
191 |
|
ForkJoinPool pool = getPool(); |
192 |
|
if (pool != null) { |
193 |
|
int s; // Clear signal bits while setting completion status |
194 |
< |
do;while ((s = status) >= 0 && !casStatus(s, completion)); |
194 |
> |
do {} while ((s = status) >= 0 && !casStatus(s, completion)); |
195 |
|
|
196 |
|
if ((s & SIGNAL_MASK) != 0) { |
197 |
|
if ((s &= INTERNAL_SIGNAL_MASK) != 0) |
198 |
|
pool.updateRunningCount(s); |
199 |
< |
synchronized(this) { notifyAll(); } |
199 |
> |
synchronized (this) { notifyAll(); } |
200 |
|
} |
201 |
|
} |
202 |
|
else |
209 |
|
*/ |
210 |
|
private void externallySetCompletion(int completion) { |
211 |
|
int s; |
212 |
< |
do;while ((s = status) >= 0 && |
213 |
< |
!casStatus(s, (s & SIGNAL_MASK) | completion)); |
214 |
< |
synchronized(this) { notifyAll(); } |
212 |
> |
do {} while ((s = status) >= 0 && |
213 |
> |
!casStatus(s, (s & SIGNAL_MASK) | completion)); |
214 |
> |
synchronized (this) { notifyAll(); } |
215 |
|
} |
216 |
|
|
217 |
|
/** |
218 |
< |
* Sets status to indicate normal completion |
218 |
> |
* Sets status to indicate normal completion. |
219 |
|
*/ |
220 |
|
final void setNormalCompletion() { |
221 |
|
// Try typical fast case -- single CAS, no signal, not already done. |
227 |
|
// internal waiting and notification |
228 |
|
|
229 |
|
/** |
230 |
< |
* Performs the actual monitor wait for awaitDone |
230 |
> |
* Performs the actual monitor wait for awaitDone. |
231 |
|
*/ |
232 |
|
private void doAwaitDone() { |
233 |
|
// Minimize lock bias and in/de-flation effects by maximizing |
234 |
|
// chances of waiting inside sync |
235 |
|
try { |
236 |
|
while (status >= 0) |
237 |
< |
synchronized(this) { if (status >= 0) wait(); } |
237 |
> |
synchronized (this) { if (status >= 0) wait(); } |
238 |
|
} catch (InterruptedException ie) { |
239 |
|
onInterruptedWait(); |
240 |
|
} |
241 |
|
} |
242 |
|
|
243 |
|
/** |
244 |
< |
* Performs the actual monitor wait for awaitDone |
244 |
> |
* Performs the actual timed monitor wait for awaitDone. |
245 |
|
*/ |
246 |
|
private void doAwaitDone(long startTime, long nanos) { |
247 |
< |
synchronized(this) { |
247 |
> |
synchronized (this) { |
248 |
|
try { |
249 |
|
while (status >= 0) { |
250 |
|
long nt = nanos - System.nanoTime() - startTime; |
251 |
|
if (nt <= 0) |
252 |
|
break; |
253 |
< |
wait(nt / 1000000, (int)(nt % 1000000)); |
253 |
> |
wait(nt / 1000000, (int) (nt % 1000000)); |
254 |
|
} |
255 |
|
} catch (InterruptedException ie) { |
256 |
|
onInterruptedWait(); |
266 |
|
* |
267 |
|
* @return status upon exit |
268 |
|
*/ |
269 |
< |
private int awaitDone(ForkJoinWorkerThread w, boolean maintainParallelism) { |
270 |
< |
ForkJoinPool pool = w == null? null : w.pool; |
269 |
> |
private int awaitDone(ForkJoinWorkerThread w, |
270 |
> |
boolean maintainParallelism) { |
271 |
> |
ForkJoinPool pool = (w == null) ? null : w.pool; |
272 |
|
int s; |
273 |
|
while ((s = status) >= 0) { |
274 |
< |
if (casStatus(s, pool == null? s|EXTERNAL_SIGNAL : s+1)) { |
274 |
> |
if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) { |
275 |
|
if (pool == null || !pool.preJoin(this, maintainParallelism)) |
276 |
|
doAwaitDone(); |
277 |
|
if (((s = status) & INTERNAL_SIGNAL_MASK) != 0) |
284 |
|
|
285 |
|
/** |
286 |
|
* Timed version of awaitDone |
287 |
+ |
* |
288 |
|
* @return status upon exit |
289 |
|
*/ |
290 |
|
private int awaitDone(ForkJoinWorkerThread w, long nanos) { |
291 |
< |
ForkJoinPool pool = w == null? null : w.pool; |
291 |
> |
ForkJoinPool pool = (w == null) ? null : w.pool; |
292 |
|
int s; |
293 |
|
while ((s = status) >= 0) { |
294 |
< |
if (casStatus(s, pool == null? s|EXTERNAL_SIGNAL : s+1)) { |
294 |
> |
if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) { |
295 |
|
long startTime = System.nanoTime(); |
296 |
|
if (pool == null || !pool.preJoin(this, false)) |
297 |
|
doAwaitDone(startTime, nanos); |
313 |
|
*/ |
314 |
|
private void adjustPoolCountsOnUnblock(ForkJoinPool pool) { |
315 |
|
int s; |
316 |
< |
do;while ((s = status) < 0 && !casStatus(s, s & COMPLETION_MASK)); |
316 |
> |
do {} while ((s = status) < 0 && !casStatus(s, s & COMPLETION_MASK)); |
317 |
|
if (pool != null && (s &= INTERNAL_SIGNAL_MASK) != 0) |
318 |
|
pool.updateRunningCount(s); |
319 |
|
} |
368 |
|
|
369 |
|
/** |
370 |
|
* Returns result or throws exception using j.u.c.Future conventions. |
371 |
< |
* Only call when isDone known to be true. |
371 |
> |
* Only call when {@code isDone} known to be true. |
372 |
|
*/ |
373 |
|
private V reportFutureResult() |
374 |
|
throws ExecutionException, InterruptedException { |
434 |
|
try { |
435 |
|
if (!exec()) |
436 |
|
return; |
437 |
< |
} catch(Throwable rex) { |
437 |
> |
} catch (Throwable rex) { |
438 |
|
setDoneExceptionally(rex); |
439 |
|
return; |
440 |
|
} |
466 |
|
final void cancelIgnoringExceptions() { |
467 |
|
try { |
468 |
|
cancel(false); |
469 |
< |
} catch(Throwable ignore) { |
469 |
> |
} catch (Throwable ignore) { |
470 |
|
} |
471 |
|
} |
472 |
|
|
478 |
|
ForkJoinTask<?> t; |
479 |
|
while ((s = status) >= 0 && (t = w.scanWhileJoining(this)) != null) |
480 |
|
t.quietlyExec(); |
481 |
< |
return (s >= 0)? awaitDone(w, false) : s; // block if no work |
481 |
> |
return (s >= 0) ? awaitDone(w, false) : s; // block if no work |
482 |
|
} |
483 |
|
|
484 |
|
// public methods |
488 |
|
* necessarily enforced, it is a usage error to fork a task more |
489 |
|
* than once unless it has completed and been reinitialized. This |
490 |
|
* method may be invoked only from within ForkJoinTask |
491 |
< |
* computations. Attempts to invoke in other contexts result in |
492 |
< |
* exceptions or errors possibly including ClassCastException. |
493 |
< |
*/ |
494 |
< |
public final void fork() { |
495 |
< |
((ForkJoinWorkerThread)(Thread.currentThread())).pushTask(this); |
491 |
> |
* computations (as may be determined using method {@link |
492 |
> |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
493 |
> |
* in exceptions or errors, possibly including ClassCastException. |
494 |
> |
* |
495 |
> |
* @return {@code this}, to simplify usage. |
496 |
> |
*/ |
497 |
> |
public final ForkJoinTask<V> fork() { |
498 |
> |
((ForkJoinWorkerThread) Thread.currentThread()) |
499 |
> |
.pushTask(this); |
500 |
> |
return this; |
501 |
|
} |
502 |
|
|
503 |
|
/** |
533 |
|
/** |
534 |
|
* Forks both tasks, returning when {@code isDone} holds for |
535 |
|
* both of them or an exception is encountered. This method may be |
536 |
< |
* invoked only from within ForkJoinTask computations. Attempts to |
537 |
< |
* invoke in other contexts result in exceptions or errors |
536 |
> |
* invoked only from within ForkJoinTask computations (as may be |
537 |
> |
* determined using method {@link #inForkJoinPool}). Attempts to |
538 |
> |
* invoke in other contexts result in exceptions or errors, |
539 |
|
* possibly including ClassCastException. |
540 |
|
* |
541 |
|
* @param t1 one task |
553 |
|
* Forks the given tasks, returning when {@code isDone} holds |
554 |
|
* for all of them. If any task encounters an exception, others |
555 |
|
* may be cancelled. This method may be invoked only from within |
556 |
< |
* ForkJoinTask computations. Attempts to invoke in other contexts |
557 |
< |
* result in exceptions or errors possibly including ClassCastException. |
556 |
> |
* ForkJoinTask computations (as may be determined using method |
557 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
558 |
> |
* result in exceptions or errors, possibly including |
559 |
> |
* ClassCastException. |
560 |
|
* |
561 |
|
* @param tasks the array of tasks |
562 |
|
* @throws NullPointerException if tasks or any element are null |
599 |
|
* Forks all tasks in the collection, returning when |
600 |
|
* {@code isDone} holds for all of them. If any task |
601 |
|
* encounters an exception, others may be cancelled. This method |
602 |
< |
* may be invoked only from within ForkJoinTask |
603 |
< |
* computations. Attempts to invoke in other contexts result in |
604 |
< |
* exceptions or errors possibly including ClassCastException. |
602 |
> |
* may be invoked only from within ForkJoinTask computations (as |
603 |
> |
* may be determined using method {@link |
604 |
> |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
605 |
> |
* in exceptions or errors, possibly including ClassCastException. |
606 |
|
* |
607 |
|
* @param tasks the collection of tasks |
608 |
+ |
* @return the tasks argument, to simplify usage |
609 |
|
* @throws NullPointerException if tasks or any element are null |
610 |
|
* @throws RuntimeException or Error if any task did so |
611 |
|
*/ |
612 |
< |
public static void invokeAll(Collection<? extends ForkJoinTask<?>> tasks) { |
613 |
< |
if (!(tasks instanceof List)) { |
614 |
< |
invokeAll(tasks.toArray(new ForkJoinTask[tasks.size()])); |
615 |
< |
return; |
612 |
> |
public static <T extends ForkJoinTask<?>> Collection<T> invokeAll(Collection<T> tasks) { |
613 |
> |
if (!(tasks instanceof List<?>)) { |
614 |
> |
invokeAll(tasks.toArray(new ForkJoinTask<?>[tasks.size()])); |
615 |
> |
return tasks; |
616 |
|
} |
617 |
+ |
@SuppressWarnings("unchecked") |
618 |
|
List<? extends ForkJoinTask<?>> ts = |
619 |
< |
(List<? extends ForkJoinTask<?>>)tasks; |
619 |
> |
(List<? extends ForkJoinTask<?>>) tasks; |
620 |
|
Throwable ex = null; |
621 |
|
int last = ts.size() - 1; |
622 |
|
for (int i = last; i >= 0; --i) { |
647 |
|
} |
648 |
|
if (ex != null) |
649 |
|
rethrowException(ex); |
650 |
+ |
return tasks; |
651 |
|
} |
652 |
|
|
653 |
|
/** |
654 |
< |
* Returns true if the computation performed by this task has |
655 |
< |
* completed (or has been cancelled). |
654 |
> |
* Returns {@code true} if the computation performed by this task |
655 |
> |
* has completed (or has been cancelled). |
656 |
|
* |
657 |
< |
* @return true if this computation has completed |
657 |
> |
* @return {@code true} if this computation has completed |
658 |
|
*/ |
659 |
|
public final boolean isDone() { |
660 |
|
return status < 0; |
661 |
|
} |
662 |
|
|
663 |
|
/** |
664 |
< |
* Returns true if this task was cancelled. |
664 |
> |
* Returns {@code true} if this task was cancelled. |
665 |
|
* |
666 |
< |
* @return true if this task was cancelled |
666 |
> |
* @return {@code true} if this task was cancelled |
667 |
|
*/ |
668 |
|
public final boolean isCancelled() { |
669 |
|
return (status & COMPLETION_MASK) == CANCELLED; |
672 |
|
/** |
673 |
|
* Asserts that the results of this task's computation will not be |
674 |
|
* used. If a cancellation occurs before attempting to execute this |
675 |
< |
* task, then execution will be suppressed, {@code isCancelled} |
676 |
< |
* will report true, and {@code join} will result in a |
675 |
> |
* task, execution will be suppressed, {@link #isCancelled} |
676 |
> |
* will report true, and {@link #join} will result in a |
677 |
|
* {@code CancellationException} being thrown. Otherwise, when |
678 |
|
* cancellation races with completion, there are no guarantees |
679 |
< |
* about whether {@code isCancelled} will report true, whether |
680 |
< |
* {@code join} will return normally or via an exception, or |
681 |
< |
* whether these behaviors will remain consistent upon repeated |
679 |
> |
* about whether {@code isCancelled} will report {@code true}, |
680 |
> |
* whether {@code join} will return normally or via an exception, |
681 |
> |
* or whether these behaviors will remain consistent upon repeated |
682 |
|
* invocation. |
683 |
|
* |
684 |
|
* <p>This method may be overridden in subclasses, but if so, must |
688 |
|
* <p> This method is designed to be invoked by <em>other</em> |
689 |
|
* tasks. To terminate the current task, you can just return or |
690 |
|
* throw an unchecked exception from its computation method, or |
691 |
< |
* invoke {@code completeExceptionally}. |
691 |
> |
* invoke {@link #completeExceptionally}. |
692 |
|
* |
693 |
|
* @param mayInterruptIfRunning this value is ignored in the |
694 |
|
* default implementation because tasks are not in general |
695 |
< |
* cancelled via interruption. |
695 |
> |
* cancelled via interruption |
696 |
|
* |
697 |
< |
* @return true if this task is now cancelled |
697 |
> |
* @return {@code true} if this task is now cancelled |
698 |
|
*/ |
699 |
|
public boolean cancel(boolean mayInterruptIfRunning) { |
700 |
|
setCompletion(CANCELLED); |
702 |
|
} |
703 |
|
|
704 |
|
/** |
705 |
< |
* Returns true if this task threw an exception or was cancelled. |
705 |
> |
* Returns {@code true} if this task threw an exception or was cancelled. |
706 |
|
* |
707 |
< |
* @return true if this task threw an exception or was cancelled |
707 |
> |
* @return {@code true} if this task threw an exception or was cancelled |
708 |
|
*/ |
709 |
|
public final boolean isCompletedAbnormally() { |
710 |
|
return (status & COMPLETION_MASK) < NORMAL; |
715 |
|
* CancellationException if cancelled, or null if none or if the |
716 |
|
* method has not yet completed. |
717 |
|
* |
718 |
< |
* @return the exception, or null if none |
718 |
> |
* @return the exception, or {@code null} if none |
719 |
|
*/ |
720 |
|
public final Throwable getException() { |
721 |
|
int s = status & COMPLETION_MASK; |
742 |
|
*/ |
743 |
|
public void completeExceptionally(Throwable ex) { |
744 |
|
setDoneExceptionally((ex instanceof RuntimeException) || |
745 |
< |
(ex instanceof Error)? ex : |
745 |
> |
(ex instanceof Error) ? ex : |
746 |
|
new RuntimeException(ex)); |
747 |
|
} |
748 |
|
|
761 |
|
public void complete(V value) { |
762 |
|
try { |
763 |
|
setRawResult(value); |
764 |
< |
} catch(Throwable rex) { |
764 |
> |
} catch (Throwable rex) { |
765 |
|
setDoneExceptionally(rex); |
766 |
|
return; |
767 |
|
} |
791 |
|
* current task and that of any other task that might be executed |
792 |
|
* while helping. (This usually holds for pure divide-and-conquer |
793 |
|
* tasks). This method may be invoked only from within |
794 |
< |
* ForkJoinTask computations. Attempts to invoke in other contexts |
795 |
< |
* result in exceptions or errors possibly including ClassCastException. |
794 |
> |
* ForkJoinTask computations (as may be determined using method |
795 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
796 |
> |
* result in exceptions or errors, possibly including |
797 |
> |
* ClassCastException. |
798 |
|
* |
799 |
|
* @return the computed result |
800 |
|
*/ |
801 |
|
public final V helpJoin() { |
802 |
< |
ForkJoinWorkerThread w = (ForkJoinWorkerThread)(Thread.currentThread()); |
802 |
> |
ForkJoinWorkerThread w = (ForkJoinWorkerThread) Thread.currentThread(); |
803 |
|
if (status < 0 || !w.unpushTask(this) || !tryExec()) |
804 |
|
reportException(busyJoin(w)); |
805 |
|
return getRawResult(); |
808 |
|
/** |
809 |
|
* Possibly executes other tasks until this task is ready. This |
810 |
|
* method may be invoked only from within ForkJoinTask |
811 |
< |
* computations. Attempts to invoke in other contexts result in |
812 |
< |
* exceptions or errors possibly including ClassCastException. |
811 |
> |
* computations (as may be determined using method {@link |
812 |
> |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
813 |
> |
* in exceptions or errors, possibly including ClassCastException. |
814 |
|
*/ |
815 |
|
public final void quietlyHelpJoin() { |
816 |
|
if (status >= 0) { |
817 |
|
ForkJoinWorkerThread w = |
818 |
< |
(ForkJoinWorkerThread)(Thread.currentThread()); |
818 |
> |
(ForkJoinWorkerThread) Thread.currentThread(); |
819 |
|
if (!w.unpushTask(this) || !tryQuietlyInvoke()) |
820 |
|
busyJoin(w); |
821 |
|
} |
854 |
|
* joined, instead executing them until all are processed. |
855 |
|
*/ |
856 |
|
public static void helpQuiesce() { |
857 |
< |
((ForkJoinWorkerThread)(Thread.currentThread())). |
858 |
< |
helpQuiescePool(); |
857 |
> |
((ForkJoinWorkerThread) Thread.currentThread()) |
858 |
> |
.helpQuiescePool(); |
859 |
|
} |
860 |
|
|
861 |
|
/** |
876 |
|
|
877 |
|
/** |
878 |
|
* Returns the pool hosting the current task execution, or null |
879 |
< |
* if this task is executing outside of any pool. |
879 |
> |
* if this task is executing outside of any ForkJoinPool. |
880 |
|
* |
881 |
< |
* @return the pool, or null if none |
881 |
> |
* @return the pool, or {@code null} if none |
882 |
|
*/ |
883 |
|
public static ForkJoinPool getPool() { |
884 |
|
Thread t = Thread.currentThread(); |
885 |
< |
return ((t instanceof ForkJoinWorkerThread)? |
886 |
< |
((ForkJoinWorkerThread)t).pool : null); |
885 |
> |
return (t instanceof ForkJoinWorkerThread) ? |
886 |
> |
((ForkJoinWorkerThread) t).pool : null; |
887 |
> |
} |
888 |
> |
|
889 |
> |
/** |
890 |
> |
* Returns {@code true} if the current thread is executing as a |
891 |
> |
* ForkJoinPool computation. |
892 |
> |
* |
893 |
> |
* @return {@code true} if the current thread is executing as a |
894 |
> |
* ForkJoinPool computation, or false otherwise |
895 |
> |
*/ |
896 |
> |
public static boolean inForkJoinPool() { |
897 |
> |
return Thread.currentThread() instanceof ForkJoinWorkerThread; |
898 |
|
} |
899 |
|
|
900 |
|
/** |
904 |
|
* another thread. This method may be useful when arranging |
905 |
|
* alternative local processing of tasks that could have been, but |
906 |
|
* were not, stolen. This method may be invoked only from within |
907 |
< |
* ForkJoinTask computations. Attempts to invoke in other contexts |
908 |
< |
* result in exceptions or errors possibly including ClassCastException. |
907 |
> |
* ForkJoinTask computations (as may be determined using method |
908 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
909 |
> |
* result in exceptions or errors, possibly including |
910 |
> |
* ClassCastException. |
911 |
|
* |
912 |
< |
* @return true if unforked |
912 |
> |
* @return {@code true} if unforked |
913 |
|
*/ |
914 |
|
public boolean tryUnfork() { |
915 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())).unpushTask(this); |
915 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
916 |
> |
.unpushTask(this); |
917 |
|
} |
918 |
|
|
919 |
|
/** |
925 |
|
* @return the number of tasks |
926 |
|
*/ |
927 |
|
public static int getQueuedTaskCount() { |
928 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())). |
929 |
< |
getQueueSize(); |
928 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
929 |
> |
.getQueueSize(); |
930 |
|
} |
931 |
|
|
932 |
|
/** |
942 |
|
* @return the surplus number of tasks, which may be negative |
943 |
|
*/ |
944 |
|
public static int getSurplusQueuedTaskCount() { |
945 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())) |
945 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
946 |
|
.getEstimatedSurplusTaskCount(); |
947 |
|
} |
948 |
|
|
949 |
|
// Extension methods |
950 |
|
|
951 |
|
/** |
952 |
< |
* Returns the result that would be returned by {@code join}, |
953 |
< |
* even if this task completed abnormally, or null if this task is |
954 |
< |
* not known to have been completed. This method is designed to |
955 |
< |
* aid debugging, as well as to support extensions. Its use in any |
956 |
< |
* other context is discouraged. |
952 |
> |
* Returns the result that would be returned by {@link #join}, even |
953 |
> |
* if this task completed abnormally, or {@code null} if this task |
954 |
> |
* is not known to have been completed. This method is designed |
955 |
> |
* to aid debugging, as well as to support extensions. Its use in |
956 |
> |
* any other context is discouraged. |
957 |
|
* |
958 |
< |
* @return the result, or null if not completed |
958 |
> |
* @return the result, or {@code null} if not completed |
959 |
|
*/ |
960 |
|
public abstract V getRawResult(); |
961 |
|
|
974 |
|
* called otherwise. The return value controls whether this task |
975 |
|
* is considered to be done normally. It may return false in |
976 |
|
* asynchronous actions that require explicit invocations of |
977 |
< |
* {@code complete} to become joinable. It may throw exceptions |
977 |
> |
* {@link #complete} to become joinable. It may throw exceptions |
978 |
|
* to indicate abnormal exit. |
979 |
|
* |
980 |
< |
* @return true if completed normally |
980 |
> |
* @return {@code true} if completed normally |
981 |
|
* @throws Error or RuntimeException if encountered during computation |
982 |
|
*/ |
983 |
|
protected abstract boolean exec(); |
989 |
|
* be polled or executed next. This method is designed primarily |
990 |
|
* to support extensions, and is unlikely to be useful otherwise. |
991 |
|
* This method may be invoked only from within ForkJoinTask |
992 |
< |
* computations. Attempts to invoke in other contexts result in |
993 |
< |
* exceptions or errors possibly including ClassCastException. |
992 |
> |
* computations (as may be determined using method {@link |
993 |
> |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
994 |
> |
* in exceptions or errors, possibly including ClassCastException. |
995 |
|
* |
996 |
< |
* @return the next task, or null if none are available |
996 |
> |
* @return the next task, or {@code null} if none are available |
997 |
|
*/ |
998 |
|
protected static ForkJoinTask<?> peekNextLocalTask() { |
999 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())).peekTask(); |
999 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1000 |
> |
.peekTask(); |
1001 |
|
} |
1002 |
|
|
1003 |
|
/** |
1005 |
|
* queued by the current thread but not yet executed. This method |
1006 |
|
* is designed primarily to support extensions, and is unlikely to |
1007 |
|
* be useful otherwise. This method may be invoked only from |
1008 |
< |
* within ForkJoinTask computations. Attempts to invoke in other |
1009 |
< |
* contexts result in exceptions or errors possibly including |
1008 |
> |
* within ForkJoinTask computations (as may be determined using |
1009 |
> |
* method {@link #inForkJoinPool}). Attempts to invoke in other |
1010 |
> |
* contexts result in exceptions or errors, possibly including |
1011 |
|
* ClassCastException. |
1012 |
|
* |
1013 |
< |
* @return the next task, or null if none are available |
1013 |
> |
* @return the next task, or {@code null} if none are available |
1014 |
|
*/ |
1015 |
|
protected static ForkJoinTask<?> pollNextLocalTask() { |
1016 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())).pollLocalTask(); |
1016 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1017 |
> |
.pollLocalTask(); |
1018 |
|
} |
1019 |
|
|
1020 |
|
/** |
1026 |
|
* of the pool this task is operating in. This method is designed |
1027 |
|
* primarily to support extensions, and is unlikely to be useful |
1028 |
|
* otherwise. This method may be invoked only from within |
1029 |
< |
* ForkJoinTask computations. Attempts to invoke in other contexts |
1030 |
< |
* result in exceptions or errors possibly including |
1029 |
> |
* ForkJoinTask computations (as may be determined using method |
1030 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
1031 |
> |
* result in exceptions or errors, possibly including |
1032 |
|
* ClassCastException. |
1033 |
|
* |
1034 |
< |
* @return a task, or null if none are available |
1034 |
> |
* @return a task, or {@code null} if none are available |
1035 |
|
*/ |
1036 |
|
protected static ForkJoinTask<?> pollTask() { |
1037 |
< |
return ((ForkJoinWorkerThread)(Thread.currentThread())). |
1038 |
< |
pollTask(); |
1037 |
> |
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1038 |
> |
.pollTask(); |
1039 |
> |
} |
1040 |
> |
|
1041 |
> |
// adaptors |
1042 |
> |
|
1043 |
> |
/** |
1044 |
> |
* Returns a new ForkJoinTask that performs the {@code run} |
1045 |
> |
* method of the given Runnable as its action, and returns a null |
1046 |
> |
* result upon {@code join}. |
1047 |
> |
* |
1048 |
> |
* @param runnable the runnable action |
1049 |
> |
* @return the task |
1050 |
> |
*/ |
1051 |
> |
public static ForkJoinTask<Void> adapt(Runnable runnable) { |
1052 |
> |
return new ForkJoinPool.AdaptedRunnable<Void>(runnable, null); |
1053 |
> |
} |
1054 |
> |
|
1055 |
> |
/** |
1056 |
> |
* Returns a new ForkJoinTask that performs the {@code run} |
1057 |
> |
* method of the given Runnable as its action, and returns the |
1058 |
> |
* given result upon {@code join}. |
1059 |
> |
* |
1060 |
> |
* @param runnable the runnable action |
1061 |
> |
* @param result the result upon completion |
1062 |
> |
* @return the task |
1063 |
> |
*/ |
1064 |
> |
public static <T> ForkJoinTask<T> adapt(Runnable runnable, T result) { |
1065 |
> |
return new ForkJoinPool.AdaptedRunnable<T>(runnable, result); |
1066 |
> |
} |
1067 |
> |
|
1068 |
> |
/** |
1069 |
> |
* Returns a new ForkJoinTask that performs the {@code call} |
1070 |
> |
* method of the given Callable as its action, and returns its |
1071 |
> |
* result upon {@code join}, translating any checked |
1072 |
> |
* exceptions encountered into {@code RuntimeException}. |
1073 |
> |
* |
1074 |
> |
* @param callable the callable action |
1075 |
> |
* @return the task |
1076 |
> |
*/ |
1077 |
> |
public static <T> ForkJoinTask<T> adapt(Callable<T> callable) { |
1078 |
> |
return new ForkJoinPool.AdaptedCallable<T>(callable); |
1079 |
|
} |
1080 |
|
|
1081 |
|
// Serialization support |
1086 |
|
* Save the state to a stream. |
1087 |
|
* |
1088 |
|
* @serialData the current run status and the exception thrown |
1089 |
< |
* during execution, or null if none |
1089 |
> |
* during execution, or {@code null} if none |
1090 |
|
* @param s the stream |
1091 |
|
*/ |
1092 |
|
private void writeObject(java.io.ObjectOutputStream s) |
1107 |
|
status |= EXTERNAL_SIGNAL; // conservatively set external signal |
1108 |
|
Object ex = s.readObject(); |
1109 |
|
if (ex != null) |
1110 |
< |
setDoneExceptionally((Throwable)ex); |
1110 |
> |
setDoneExceptionally((Throwable) ex); |
1111 |
> |
} |
1112 |
> |
|
1113 |
> |
// Unsafe mechanics |
1114 |
> |
|
1115 |
> |
private static final sun.misc.Unsafe UNSAFE = getUnsafe(); |
1116 |
> |
private static final long statusOffset = |
1117 |
> |
objectFieldOffset("status", ForkJoinTask.class); |
1118 |
> |
|
1119 |
> |
private static long objectFieldOffset(String field, Class<?> klazz) { |
1120 |
> |
try { |
1121 |
> |
return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field)); |
1122 |
> |
} catch (NoSuchFieldException e) { |
1123 |
> |
// Convert Exception to corresponding Error |
1124 |
> |
NoSuchFieldError error = new NoSuchFieldError(field); |
1125 |
> |
error.initCause(e); |
1126 |
> |
throw error; |
1127 |
> |
} |
1128 |
|
} |
1129 |
|
|
1130 |
< |
// Temporary Unsafe mechanics for preliminary release |
1131 |
< |
private static Unsafe getUnsafe() throws Throwable { |
1130 |
> |
/** |
1131 |
> |
* Returns a sun.misc.Unsafe. Suitable for use in a 3rd party package. |
1132 |
> |
* Replace with a simple call to Unsafe.getUnsafe when integrating |
1133 |
> |
* into a jdk. |
1134 |
> |
* |
1135 |
> |
* @return a sun.misc.Unsafe |
1136 |
> |
*/ |
1137 |
> |
private static sun.misc.Unsafe getUnsafe() { |
1138 |
|
try { |
1139 |
< |
return Unsafe.getUnsafe(); |
1139 |
> |
return sun.misc.Unsafe.getUnsafe(); |
1140 |
|
} catch (SecurityException se) { |
1141 |
|
try { |
1142 |
|
return java.security.AccessController.doPrivileged |
1143 |
< |
(new java.security.PrivilegedExceptionAction<Unsafe>() { |
1144 |
< |
public Unsafe run() throws Exception { |
1145 |
< |
return getUnsafePrivileged(); |
1143 |
> |
(new java.security |
1144 |
> |
.PrivilegedExceptionAction<sun.misc.Unsafe>() { |
1145 |
> |
public sun.misc.Unsafe run() throws Exception { |
1146 |
> |
java.lang.reflect.Field f = sun.misc |
1147 |
> |
.Unsafe.class.getDeclaredField("theUnsafe"); |
1148 |
> |
f.setAccessible(true); |
1149 |
> |
return (sun.misc.Unsafe) f.get(null); |
1150 |
|
}}); |
1151 |
|
} catch (java.security.PrivilegedActionException e) { |
1152 |
< |
throw e.getCause(); |
1152 |
> |
throw new RuntimeException("Could not initialize intrinsics", |
1153 |
> |
e.getCause()); |
1154 |
|
} |
1155 |
|
} |
1156 |
|
} |
1049 |
– |
|
1050 |
– |
private static Unsafe getUnsafePrivileged() |
1051 |
– |
throws NoSuchFieldException, IllegalAccessException { |
1052 |
– |
Field f = Unsafe.class.getDeclaredField("theUnsafe"); |
1053 |
– |
f.setAccessible(true); |
1054 |
– |
return (Unsafe) f.get(null); |
1055 |
– |
} |
1056 |
– |
|
1057 |
– |
private static long fieldOffset(String fieldName) |
1058 |
– |
throws NoSuchFieldException { |
1059 |
– |
return UNSAFE.objectFieldOffset |
1060 |
– |
(ForkJoinTask.class.getDeclaredField(fieldName)); |
1061 |
– |
} |
1062 |
– |
|
1063 |
– |
static final Unsafe UNSAFE; |
1064 |
– |
static final long statusOffset; |
1065 |
– |
|
1066 |
– |
static { |
1067 |
– |
try { |
1068 |
– |
UNSAFE = getUnsafe(); |
1069 |
– |
statusOffset = fieldOffset("status"); |
1070 |
– |
} catch (Throwable e) { |
1071 |
– |
throw new RuntimeException("Could not initialize intrinsics", e); |
1072 |
– |
} |
1073 |
– |
} |
1074 |
– |
|
1157 |
|
} |