16 |
|
import java.util.WeakHashMap; |
17 |
|
|
18 |
|
/** |
19 |
< |
* Abstract base class for tasks that run within a {@link |
20 |
< |
* ForkJoinPool}. A ForkJoinTask is a thread-like entity that is much |
19 |
> |
* Abstract base class for tasks that run within a {@link ForkJoinPool}. |
20 |
> |
* A {@code ForkJoinTask} is a thread-like entity that is much |
21 |
|
* lighter weight than a normal thread. Huge numbers of tasks and |
22 |
|
* subtasks may be hosted by a small number of actual threads in a |
23 |
|
* ForkJoinPool, at the price of some usage limitations. |
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 |
33 |
< |
* 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 |
76 |
|
* |
77 |
|
* <p> The ForkJoinTask class is not usually directly subclassed. |
78 |
|
* Instead, you subclass one of the abstract classes that support a |
79 |
< |
* particular style of fork/join processing. Normally, a concrete |
79 |
> |
* particular style of fork/join processing, typically {@link |
80 |
> |
* RecursiveAction} for computations that do not return results, or |
81 |
> |
* {@link RecursiveTask} for those that do. Normally, a concrete |
82 |
|
* ForkJoinTask subclass declares fields comprising its parameters, |
83 |
|
* established in a constructor, and then defines a {@code compute} |
84 |
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* method that somehow uses the control methods supplied by this base |
95 |
|
* lightweight task scheduling framework, and so cannot be overridden. |
96 |
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* Developers creating new basic styles of fork/join processing should |
97 |
|
* minimally implement {@code protected} methods |
98 |
< |
* {@code exec}, {@code setRawResult}, and |
99 |
< |
* {@code getRawResult}, while also introducing an abstract |
98 |
> |
* {@link #exec}, {@link #setRawResult}, and |
99 |
> |
* {@link #getRawResult}, while also introducing an abstract |
100 |
|
* computational method that can be implemented in its subclasses, |
101 |
|
* possibly relying on other {@code protected} methods provided |
102 |
|
* by this class. |
108 |
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* parallelism cannot improve throughput. If too small, then memory |
109 |
|
* and internal task maintenance overhead may overwhelm processing. |
110 |
|
* |
111 |
+ |
* <p>This class provides {@code adapt} methods for {@link |
112 |
+ |
* java.lang.Runnable} and {@link java.util.concurrent.Callable}, that |
113 |
+ |
* may be of use when mixing execution of ForkJoinTasks with other |
114 |
+ |
* kinds of tasks. When all tasks are of this form, consider using a |
115 |
+ |
* pool in {@link ForkJoinPool#setAsyncMode}. |
116 |
+ |
* |
117 |
|
* <p>ForkJoinTasks are {@code Serializable}, which enables them |
118 |
|
* to be used in extensions such as remote execution frameworks. It is |
119 |
|
* in general sensible to serialize tasks only before or after, but |
255 |
|
synchronized (this) { |
256 |
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try { |
257 |
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while (status >= 0) { |
258 |
< |
long nt = nanos - System.nanoTime() - startTime; |
258 |
> |
long nt = nanos - (System.nanoTime() - startTime); |
259 |
|
if (nt <= 0) |
260 |
|
break; |
261 |
|
wait(nt / 1000000, (int) (nt % 1000000)); |
500 |
|
* #inForkJoinPool}). Attempts to invoke in other contexts result |
501 |
|
* in exceptions or errors, possibly including ClassCastException. |
502 |
|
* |
503 |
< |
* @return <code>this</code>, to simplify usage. |
503 |
> |
* @return {@code this}, to simplify usage. |
504 |
|
*/ |
505 |
|
public final ForkJoinTask<V> fork() { |
506 |
|
((ForkJoinWorkerThread) Thread.currentThread()) |
539 |
|
} |
540 |
|
|
541 |
|
/** |
542 |
< |
* Forks both tasks, returning when {@code isDone} holds for |
543 |
< |
* both of them or an exception is encountered. This method may be |
542 |
> |
* Forks the given tasks, returning when {@code isDone} holds for |
543 |
> |
* each task or an exception is encountered. This method may be |
544 |
|
* invoked only from within ForkJoinTask computations (as may be |
545 |
|
* determined using method {@link #inForkJoinPool}). Attempts to |
546 |
|
* invoke in other contexts result in exceptions or errors, |
547 |
|
* possibly including ClassCastException. |
548 |
|
* |
549 |
< |
* @param t1 one task |
550 |
< |
* @param t2 the other task |
551 |
< |
* @throws NullPointerException if t1 or t2 are null |
552 |
< |
* @throws RuntimeException or Error if either task did so |
549 |
> |
* @param t1 the first task |
550 |
> |
* @param t2 the second task |
551 |
> |
* @throws NullPointerException if any task is null |
552 |
> |
* @throws RuntimeException or Error if a task did so |
553 |
|
*/ |
554 |
|
public static void invokeAll(ForkJoinTask<?>t1, ForkJoinTask<?> t2) { |
555 |
|
t2.fork(); |
558 |
|
} |
559 |
|
|
560 |
|
/** |
561 |
< |
* Forks the given tasks, returning when {@code isDone} holds |
562 |
< |
* for all of them. If any task encounters an exception, others |
563 |
< |
* may be cancelled. This method may be invoked only from within |
561 |
> |
* Forks the given tasks, returning when {@code isDone} holds for |
562 |
> |
* each task or an exception is encountered. If any task |
563 |
> |
* encounters an exception, others may be, but are not guaranteed |
564 |
> |
* to be, cancelled. This method may be invoked only from within |
565 |
|
* ForkJoinTask computations (as may be determined using method |
566 |
|
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
567 |
|
* result in exceptions or errors, possibly including |
568 |
|
* ClassCastException. |
569 |
|
* |
570 |
< |
* @param tasks the array of tasks |
570 |
> |
* Overloadings of this method exist for the special cases |
571 |
> |
* of one to four arguments. |
572 |
> |
* |
573 |
> |
* @param tasks the tasks |
574 |
|
* @throws NullPointerException if tasks or any element are null |
575 |
|
* @throws RuntimeException or Error if any task did so |
576 |
|
*/ |
608 |
|
} |
609 |
|
|
610 |
|
/** |
611 |
< |
* Forks all tasks in the collection, returning when |
612 |
< |
* {@code isDone} holds for all of them. If any task |
613 |
< |
* encounters an exception, others may be cancelled. This method |
614 |
< |
* may be invoked only from within ForkJoinTask computations (as |
615 |
< |
* may be determined using method {@link |
616 |
< |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
617 |
< |
* in exceptions or errors, possibly including ClassCastException. |
611 |
> |
* Forks all tasks in the collection, returning when {@code |
612 |
> |
* isDone} holds for each task or an exception is encountered. If |
613 |
> |
* any task encounters an exception, others may be, but are not |
614 |
> |
* guaranteed to be, cancelled. This method may be invoked only |
615 |
> |
* from within ForkJoinTask computations (as may be determined |
616 |
> |
* using method {@link #inForkJoinPool}). Attempts to invoke in |
617 |
> |
* other contexts result in exceptions or errors, possibly |
618 |
> |
* including ClassCastException. |
619 |
|
* |
620 |
|
* @param tasks the collection of tasks |
621 |
|
* @return the tasks argument, to simplify usage |
664 |
|
} |
665 |
|
|
666 |
|
/** |
667 |
< |
* Returns true if the computation performed by this task has |
668 |
< |
* completed (or has been cancelled). |
667 |
> |
* Returns {@code true} if the computation performed by this task |
668 |
> |
* has completed (or has been cancelled). |
669 |
|
* |
670 |
< |
* @return true if this computation has completed |
670 |
> |
* @return {@code true} if this computation has completed |
671 |
|
*/ |
672 |
|
public final boolean isDone() { |
673 |
|
return status < 0; |
674 |
|
} |
675 |
|
|
676 |
|
/** |
677 |
< |
* Returns true if this task was cancelled. |
677 |
> |
* Returns {@code true} if this task was cancelled. |
678 |
|
* |
679 |
< |
* @return true if this task was cancelled |
679 |
> |
* @return {@code true} if this task was cancelled |
680 |
|
*/ |
681 |
|
public final boolean isCancelled() { |
682 |
|
return (status & COMPLETION_MASK) == CANCELLED; |
685 |
|
/** |
686 |
|
* Asserts that the results of this task's computation will not be |
687 |
|
* used. If a cancellation occurs before attempting to execute this |
688 |
< |
* task, then execution will be suppressed, {@code isCancelled} |
689 |
< |
* will report true, and {@code join} will result in a |
688 |
> |
* task, execution will be suppressed, {@link #isCancelled} |
689 |
> |
* will report true, and {@link #join} will result in a |
690 |
|
* {@code CancellationException} being thrown. Otherwise, when |
691 |
|
* cancellation races with completion, there are no guarantees |
692 |
< |
* about whether {@code isCancelled} will report true, whether |
693 |
< |
* {@code join} will return normally or via an exception, or |
694 |
< |
* whether these behaviors will remain consistent upon repeated |
692 |
> |
* about whether {@code isCancelled} will report {@code true}, |
693 |
> |
* whether {@code join} will return normally or via an exception, |
694 |
> |
* or whether these behaviors will remain consistent upon repeated |
695 |
|
* invocation. |
696 |
|
* |
697 |
|
* <p>This method may be overridden in subclasses, but if so, must |
701 |
|
* <p> This method is designed to be invoked by <em>other</em> |
702 |
|
* tasks. To terminate the current task, you can just return or |
703 |
|
* throw an unchecked exception from its computation method, or |
704 |
< |
* invoke {@code completeExceptionally}. |
704 |
> |
* invoke {@link #completeExceptionally}. |
705 |
|
* |
706 |
|
* @param mayInterruptIfRunning this value is ignored in the |
707 |
|
* default implementation because tasks are not in general |
708 |
|
* cancelled via interruption |
709 |
|
* |
710 |
< |
* @return true if this task is now cancelled |
710 |
> |
* @return {@code true} if this task is now cancelled |
711 |
|
*/ |
712 |
|
public boolean cancel(boolean mayInterruptIfRunning) { |
713 |
|
setCompletion(CANCELLED); |
715 |
|
} |
716 |
|
|
717 |
|
/** |
718 |
< |
* Returns true if this task threw an exception or was cancelled. |
718 |
> |
* Returns {@code true} if this task threw an exception or was cancelled. |
719 |
|
* |
720 |
< |
* @return true if this task threw an exception or was cancelled |
720 |
> |
* @return {@code true} if this task threw an exception or was cancelled |
721 |
|
*/ |
722 |
|
public final boolean isCompletedAbnormally() { |
723 |
|
return (status & COMPLETION_MASK) < NORMAL; |
728 |
|
* CancellationException if cancelled, or null if none or if the |
729 |
|
* method has not yet completed. |
730 |
|
* |
731 |
< |
* @return the exception, or null if none |
731 |
> |
* @return the exception, or {@code null} if none |
732 |
|
*/ |
733 |
|
public final Throwable getException() { |
734 |
|
int s = status & COMPLETION_MASK; |
745 |
|
* {@code join} and related operations. This method may be used |
746 |
|
* to induce exceptions in asynchronous tasks, or to force |
747 |
|
* completion of tasks that would not otherwise complete. Its use |
748 |
< |
* in other situations is likely to be wrong. This method is |
748 |
> |
* in other situations is discouraged. This method is |
749 |
|
* overridable, but overridden versions must invoke {@code super} |
750 |
|
* implementation to maintain guarantees. |
751 |
|
* |
765 |
|
* operations. This method may be used to provide results for |
766 |
|
* asynchronous tasks, or to provide alternative handling for |
767 |
|
* tasks that would not otherwise complete normally. Its use in |
768 |
< |
* other situations is likely to be wrong. This method is |
768 |
> |
* other situations is discouraged. This method is |
769 |
|
* overridable, but overridden versions must invoke {@code super} |
770 |
|
* implementation to maintain guarantees. |
771 |
|
* |
790 |
|
|
791 |
|
public final V get(long timeout, TimeUnit unit) |
792 |
|
throws InterruptedException, ExecutionException, TimeoutException { |
793 |
+ |
long nanos = unit.toNanos(timeout); |
794 |
|
ForkJoinWorkerThread w = getWorker(); |
795 |
|
if (w == null || status < 0 || !w.unpushTask(this) || !tryQuietlyInvoke()) |
796 |
< |
awaitDone(w, unit.toNanos(timeout)); |
796 |
> |
awaitDone(w, nanos); |
797 |
|
return reportTimedFutureResult(); |
798 |
|
} |
799 |
|
|
865 |
|
* Possibly executes tasks until the pool hosting the current task |
866 |
|
* {@link ForkJoinPool#isQuiescent}. This method may be of use in |
867 |
|
* designs in which many tasks are forked, but none are explicitly |
868 |
< |
* joined, instead executing them until all are processed. |
868 |
> |
* joined, instead executing them until all are processed. This |
869 |
> |
* method may be invoked only from within ForkJoinTask |
870 |
> |
* computations (as may be determined using method {@link |
871 |
> |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
872 |
> |
* in exceptions or errors, possibly including ClassCastException. |
873 |
|
*/ |
874 |
|
public static void helpQuiesce() { |
875 |
|
((ForkJoinWorkerThread) Thread.currentThread()) |
883 |
|
* never been forked, or has been forked, then completed and all |
884 |
|
* outstanding joins of this task have also completed. Effects |
885 |
|
* under any other usage conditions are not guaranteed, and are |
886 |
< |
* almost surely wrong. This method may be useful when executing |
886 |
> |
* discouraged. This method may be useful when executing |
887 |
|
* pre-constructed trees of subtasks in loops. |
888 |
|
*/ |
889 |
|
public void reinitialize() { |
896 |
|
* Returns the pool hosting the current task execution, or null |
897 |
|
* if this task is executing outside of any ForkJoinPool. |
898 |
|
* |
899 |
< |
* @return the pool, or null if none |
899 |
> |
* @see #inForkJoinPool |
900 |
> |
* @return the pool, or {@code null} if none |
901 |
|
*/ |
902 |
|
public static ForkJoinPool getPool() { |
903 |
|
Thread t = Thread.currentThread(); |
928 |
|
* result in exceptions or errors, possibly including |
929 |
|
* ClassCastException. |
930 |
|
* |
931 |
< |
* @return true if unforked |
931 |
> |
* @return {@code true} if unforked |
932 |
|
*/ |
933 |
|
public boolean tryUnfork() { |
934 |
|
return ((ForkJoinWorkerThread) Thread.currentThread()) |
939 |
|
* Returns an estimate of the number of tasks that have been |
940 |
|
* forked by the current worker thread but not yet executed. This |
941 |
|
* value may be useful for heuristic decisions about whether to |
942 |
< |
* fork other tasks. |
943 |
< |
* |
942 |
> |
* fork other tasks. This method may be invoked only from within |
943 |
> |
* ForkJoinTask computations (as may be determined using method |
944 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
945 |
> |
* result in exceptions or errors, possibly including |
946 |
> |
* ClassCastException. |
947 |
|
* @return the number of tasks |
948 |
|
*/ |
949 |
|
public static int getQueuedTaskCount() { |
959 |
|
* usages of ForkJoinTasks, at steady state, each worker should |
960 |
|
* aim to maintain a small constant surplus (for example, 3) of |
961 |
|
* tasks, and to process computations locally if this threshold is |
962 |
< |
* exceeded. |
963 |
< |
* |
962 |
> |
* exceeded. This method may be invoked only from within |
963 |
> |
* ForkJoinTask computations (as may be determined using method |
964 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
965 |
> |
* result in exceptions or errors, possibly including |
966 |
> |
* ClassCastException. * |
967 |
|
* @return the surplus number of tasks, which may be negative |
968 |
|
*/ |
969 |
|
public static int getSurplusQueuedTaskCount() { |
974 |
|
// Extension methods |
975 |
|
|
976 |
|
/** |
977 |
< |
* Returns the result that would be returned by {@code join}, |
978 |
< |
* even if this task completed abnormally, or null if this task is |
979 |
< |
* not known to have been completed. This method is designed to |
980 |
< |
* aid debugging, as well as to support extensions. Its use in any |
981 |
< |
* other context is discouraged. |
977 |
> |
* Returns the result that would be returned by {@link #join}, even |
978 |
> |
* if this task completed abnormally, or {@code null} if this task |
979 |
> |
* is not known to have been completed. This method is designed |
980 |
> |
* to aid debugging, as well as to support extensions. Its use in |
981 |
> |
* any other context is discouraged. |
982 |
|
* |
983 |
< |
* @return the result, or null if not completed |
983 |
> |
* @return the result, or {@code null} if not completed |
984 |
|
*/ |
985 |
|
public abstract V getRawResult(); |
986 |
|
|
999 |
|
* called otherwise. The return value controls whether this task |
1000 |
|
* is considered to be done normally. It may return false in |
1001 |
|
* asynchronous actions that require explicit invocations of |
1002 |
< |
* {@code complete} to become joinable. It may throw exceptions |
1002 |
> |
* {@link #complete} to become joinable. It may throw exceptions |
1003 |
|
* to indicate abnormal exit. |
1004 |
|
* |
1005 |
< |
* @return true if completed normally |
1005 |
> |
* @return {@code true} if completed normally |
1006 |
|
* @throws Error or RuntimeException if encountered during computation |
1007 |
|
*/ |
1008 |
|
protected abstract boolean exec(); |
1009 |
|
|
1010 |
|
/** |
1011 |
< |
* Returns, but does not unschedule or execute, the task queued by |
1012 |
< |
* the current thread but not yet executed, if one is |
1011 |
> |
* Returns, but does not unschedule or execute, a task queued by |
1012 |
> |
* the current thread but not yet executed, if one is immediately |
1013 |
|
* available. There is no guarantee that this task will actually |
1014 |
< |
* be polled or executed next. This method is designed primarily |
1015 |
< |
* to support extensions, and is unlikely to be useful otherwise. |
1016 |
< |
* This method may be invoked only from within ForkJoinTask |
1017 |
< |
* computations (as may be determined using method {@link |
1018 |
< |
* #inForkJoinPool}). Attempts to invoke in other contexts result |
1019 |
< |
* in exceptions or errors, possibly including ClassCastException. |
1014 |
> |
* be polled or executed next. Conversely, this method may return |
1015 |
> |
* null even if a task exists but cannot be accessed without |
1016 |
> |
* contention with other threads. This method is designed |
1017 |
> |
* primarily to support extensions, and is unlikely to be useful |
1018 |
> |
* otherwise. This method may be invoked only from within |
1019 |
> |
* ForkJoinTask computations (as may be determined using method |
1020 |
> |
* {@link #inForkJoinPool}). Attempts to invoke in other contexts |
1021 |
> |
* result in exceptions or errors, possibly including |
1022 |
> |
* ClassCastException. |
1023 |
|
* |
1024 |
< |
* @return the next task, or null if none are available |
1024 |
> |
* @return the next task, or {@code null} if none are available |
1025 |
|
*/ |
1026 |
|
protected static ForkJoinTask<?> peekNextLocalTask() { |
1027 |
|
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1038 |
|
* contexts result in exceptions or errors, possibly including |
1039 |
|
* ClassCastException. |
1040 |
|
* |
1041 |
< |
* @return the next task, or null if none are available |
1041 |
> |
* @return the next task, or {@code null} if none are available |
1042 |
|
*/ |
1043 |
|
protected static ForkJoinTask<?> pollNextLocalTask() { |
1044 |
|
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1059 |
|
* result in exceptions or errors, possibly including |
1060 |
|
* ClassCastException. |
1061 |
|
* |
1062 |
< |
* @return a task, or null if none are available |
1062 |
> |
* @return a task, or {@code null} if none are available |
1063 |
|
*/ |
1064 |
|
protected static ForkJoinTask<?> pollTask() { |
1065 |
|
return ((ForkJoinWorkerThread) Thread.currentThread()) |
1066 |
|
.pollTask(); |
1067 |
|
} |
1068 |
|
|
1069 |
< |
// adaptors |
1069 |
> |
/** |
1070 |
> |
* Adaptor for Runnables. This implements RunnableFuture |
1071 |
> |
* to be compliant with AbstractExecutorService constraints |
1072 |
> |
* when used in ForkJoinPool. |
1073 |
> |
*/ |
1074 |
> |
static final class AdaptedRunnable<T> extends ForkJoinTask<T> |
1075 |
> |
implements RunnableFuture<T> { |
1076 |
> |
final Runnable runnable; |
1077 |
> |
final T resultOnCompletion; |
1078 |
> |
T result; |
1079 |
> |
AdaptedRunnable(Runnable runnable, T result) { |
1080 |
> |
if (runnable == null) throw new NullPointerException(); |
1081 |
> |
this.runnable = runnable; |
1082 |
> |
this.resultOnCompletion = result; |
1083 |
> |
} |
1084 |
> |
public T getRawResult() { return result; } |
1085 |
> |
public void setRawResult(T v) { result = v; } |
1086 |
> |
public boolean exec() { |
1087 |
> |
runnable.run(); |
1088 |
> |
result = resultOnCompletion; |
1089 |
> |
return true; |
1090 |
> |
} |
1091 |
> |
public void run() { invoke(); } |
1092 |
> |
private static final long serialVersionUID = 5232453952276885070L; |
1093 |
> |
} |
1094 |
> |
|
1095 |
> |
/** |
1096 |
> |
* Adaptor for Callables |
1097 |
> |
*/ |
1098 |
> |
static final class AdaptedCallable<T> extends ForkJoinTask<T> |
1099 |
> |
implements RunnableFuture<T> { |
1100 |
> |
final Callable<? extends T> callable; |
1101 |
> |
T result; |
1102 |
> |
AdaptedCallable(Callable<? extends T> callable) { |
1103 |
> |
if (callable == null) throw new NullPointerException(); |
1104 |
> |
this.callable = callable; |
1105 |
> |
} |
1106 |
> |
public T getRawResult() { return result; } |
1107 |
> |
public void setRawResult(T v) { result = v; } |
1108 |
> |
public boolean exec() { |
1109 |
> |
try { |
1110 |
> |
result = callable.call(); |
1111 |
> |
return true; |
1112 |
> |
} catch (Error err) { |
1113 |
> |
throw err; |
1114 |
> |
} catch (RuntimeException rex) { |
1115 |
> |
throw rex; |
1116 |
> |
} catch (Exception ex) { |
1117 |
> |
throw new RuntimeException(ex); |
1118 |
> |
} |
1119 |
> |
} |
1120 |
> |
public void run() { invoke(); } |
1121 |
> |
private static final long serialVersionUID = 2838392045355241008L; |
1122 |
> |
} |
1123 |
|
|
1124 |
|
/** |
1125 |
< |
* Returns a new ForkJoinTask that performs the <code>run</code> |
1125 |
> |
* Returns a new ForkJoinTask that performs the {@code run} |
1126 |
|
* method of the given Runnable as its action, and returns a null |
1127 |
< |
* result upon <code>join</code>. |
1127 |
> |
* result upon {@code join}. |
1128 |
|
* |
1129 |
|
* @param runnable the runnable action |
1130 |
|
* @return the task |
1131 |
|
*/ |
1132 |
< |
public static ForkJoinTask<Void> adapt(Runnable runnable) { |
1133 |
< |
return new ForkJoinPool.AdaptedRunnable<Void>(runnable, null); |
1132 |
> |
public static ForkJoinTask<?> adapt(Runnable runnable) { |
1133 |
> |
return new AdaptedRunnable<Void>(runnable, null); |
1134 |
|
} |
1135 |
|
|
1136 |
|
/** |
1137 |
< |
* Returns a new ForkJoinTask that performs the <code>run</code> |
1137 |
> |
* Returns a new ForkJoinTask that performs the {@code run} |
1138 |
|
* method of the given Runnable as its action, and returns the |
1139 |
< |
* given result upon <code>join</code>. |
1139 |
> |
* given result upon {@code join}. |
1140 |
|
* |
1141 |
|
* @param runnable the runnable action |
1142 |
|
* @param result the result upon completion |
1143 |
|
* @return the task |
1144 |
|
*/ |
1145 |
|
public static <T> ForkJoinTask<T> adapt(Runnable runnable, T result) { |
1146 |
< |
return new ForkJoinPool.AdaptedRunnable<T>(runnable, result); |
1146 |
> |
return new AdaptedRunnable<T>(runnable, result); |
1147 |
|
} |
1148 |
|
|
1149 |
|
/** |
1150 |
< |
* Returns a new ForkJoinTask that performs the <code>call</code> |
1150 |
> |
* Returns a new ForkJoinTask that performs the {@code call} |
1151 |
|
* method of the given Callable as its action, and returns its |
1152 |
< |
* result upon <code>join</code>, translating any checked |
1153 |
< |
* exceptions encountered into <code>RuntimeException<code>. |
1152 |
> |
* result upon {@code join}, translating any checked |
1153 |
> |
* exceptions encountered into {@code RuntimeException}. |
1154 |
|
* |
1155 |
|
* @param callable the callable action |
1156 |
|
* @return the task |
1157 |
|
*/ |
1158 |
< |
public static <T> ForkJoinTask<T> adapt(Callable<T> callable) { |
1159 |
< |
return new ForkJoinPool.AdaptedCallable<T>(callable); |
1158 |
> |
public static <T> ForkJoinTask<T> adapt(Callable<? extends T> callable) { |
1159 |
> |
return new AdaptedCallable<T>(callable); |
1160 |
|
} |
1161 |
|
|
1162 |
|
// Serialization support |
1167 |
|
* Save the state to a stream. |
1168 |
|
* |
1169 |
|
* @serialData the current run status and the exception thrown |
1170 |
< |
* during execution, or null if none |
1170 |
> |
* during execution, or {@code null} if none |
1171 |
|
* @param s the stream |
1172 |
|
*/ |
1173 |
|
private void writeObject(java.io.ObjectOutputStream s) |
1191 |
|
setDoneExceptionally((Throwable) ex); |
1192 |
|
} |
1193 |
|
|
1194 |
< |
// Unsafe mechanics for jsr166y 3rd party package. |
1194 |
> |
// Unsafe mechanics |
1195 |
> |
|
1196 |
> |
private static final sun.misc.Unsafe UNSAFE = getUnsafe(); |
1197 |
> |
private static final long statusOffset = |
1198 |
> |
objectFieldOffset("status", ForkJoinTask.class); |
1199 |
> |
|
1200 |
> |
private static long objectFieldOffset(String field, Class<?> klazz) { |
1201 |
> |
try { |
1202 |
> |
return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field)); |
1203 |
> |
} catch (NoSuchFieldException e) { |
1204 |
> |
// Convert Exception to corresponding Error |
1205 |
> |
NoSuchFieldError error = new NoSuchFieldError(field); |
1206 |
> |
error.initCause(e); |
1207 |
> |
throw error; |
1208 |
> |
} |
1209 |
> |
} |
1210 |
> |
|
1211 |
> |
/** |
1212 |
> |
* Returns a sun.misc.Unsafe. Suitable for use in a 3rd party package. |
1213 |
> |
* Replace with a simple call to Unsafe.getUnsafe when integrating |
1214 |
> |
* into a jdk. |
1215 |
> |
* |
1216 |
> |
* @return a sun.misc.Unsafe |
1217 |
> |
*/ |
1218 |
|
private static sun.misc.Unsafe getUnsafe() { |
1219 |
|
try { |
1220 |
|
return sun.misc.Unsafe.getUnsafe(); |
1221 |
|
} catch (SecurityException se) { |
1222 |
|
try { |
1223 |
|
return java.security.AccessController.doPrivileged |
1224 |
< |
(new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() { |
1224 |
> |
(new java.security |
1225 |
> |
.PrivilegedExceptionAction<sun.misc.Unsafe>() { |
1226 |
|
public sun.misc.Unsafe run() throws Exception { |
1227 |
< |
return getUnsafeByReflection(); |
1227 |
> |
java.lang.reflect.Field f = sun.misc |
1228 |
> |
.Unsafe.class.getDeclaredField("theUnsafe"); |
1229 |
> |
f.setAccessible(true); |
1230 |
> |
return (sun.misc.Unsafe) f.get(null); |
1231 |
|
}}); |
1232 |
|
} catch (java.security.PrivilegedActionException e) { |
1233 |
|
throw new RuntimeException("Could not initialize intrinsics", |
1235 |
|
} |
1236 |
|
} |
1237 |
|
} |
1131 |
– |
|
1132 |
– |
private static sun.misc.Unsafe getUnsafeByReflection() |
1133 |
– |
throws NoSuchFieldException, IllegalAccessException { |
1134 |
– |
java.lang.reflect.Field f = |
1135 |
– |
sun.misc.Unsafe.class.getDeclaredField("theUnsafe"); |
1136 |
– |
f.setAccessible(true); |
1137 |
– |
return (sun.misc.Unsafe) f.get(null); |
1138 |
– |
} |
1139 |
– |
|
1140 |
– |
private static long fieldOffset(String fieldName, Class<?> klazz) { |
1141 |
– |
try { |
1142 |
– |
return UNSAFE.objectFieldOffset(klazz.getDeclaredField(fieldName)); |
1143 |
– |
} catch (NoSuchFieldException e) { |
1144 |
– |
// Convert Exception to Error |
1145 |
– |
NoSuchFieldError error = new NoSuchFieldError(fieldName); |
1146 |
– |
error.initCause(e); |
1147 |
– |
throw error; |
1148 |
– |
} |
1149 |
– |
} |
1150 |
– |
|
1151 |
– |
private static final sun.misc.Unsafe UNSAFE = getUnsafe(); |
1152 |
– |
private static final long statusOffset = |
1153 |
– |
fieldOffset("status", ForkJoinTask.class); |
1154 |
– |
|
1238 |
|
} |