80 |
|
* <p>The execution status of tasks may be queried at several levels |
81 |
|
* of detail: {@link #isDone} is true if a task completed in any way |
82 |
|
* (including the case where a task was cancelled without executing); |
83 |
– |
* {@link #isCancelled} is true if completion was due to cancellation; |
83 |
|
* {@link #isCompletedNormally} is true if a task completed without |
84 |
< |
* cancellation or encountering an exception; {@link |
85 |
< |
* #isCompletedExceptionally} is true if if the task encountered an |
86 |
< |
* exception (in which case {@link #getException} returns the |
87 |
< |
* exception); {@link #isCancelled} is true if the task was cancelled |
88 |
< |
* (in which case {@link #getException} returns a {@link |
89 |
< |
* java.util.concurrent.CancellationException}); and {@link |
90 |
< |
* #isCompletedAbnormally} is true if a task was either cancelled or |
92 |
< |
* encountered an exception. |
84 |
> |
* cancellation or encountering an exception; {@link #isCancelled} is |
85 |
> |
* true if the task was cancelled (in which case {@link #getException} |
86 |
> |
* returns a {@link java.util.concurrent.CancellationException}); and |
87 |
> |
* {@link #isCompletedAbnormally} is true if a task was either |
88 |
> |
* cancelled or encountered an exception, in which case {@link |
89 |
> |
* #getException} will return either the encountered exception or |
90 |
> |
* {@link java.util.concurrent.CancellationException}. |
91 |
|
* |
92 |
|
* <p>The ForkJoinTask class is not usually directly subclassed. |
93 |
|
* Instead, you subclass one of the abstract classes that support a |
390 |
|
|
391 |
|
/** |
392 |
|
* Returns result or throws exception using j.u.c.Future conventions. |
393 |
< |
* Only call when {@code isDone} known to be true. |
393 |
> |
* Only call when {@code isDone} known to be true or thread known |
394 |
> |
* to be interrupted. |
395 |
|
*/ |
396 |
|
private V reportFutureResult() |
397 |
|
throws InterruptedException, ExecutionException { |
527 |
|
} |
528 |
|
|
529 |
|
/** |
530 |
< |
* Returns the result of the computation when it is ready. |
530 |
> |
* Returns the result of the computation when it {@link #isDone is done}. |
531 |
|
* This method differs from {@link #get()} in that |
532 |
|
* abnormal completion results in {@code RuntimeException} or |
533 |
|
* {@code Error}, not {@code ExecutionException}. |
558 |
|
/** |
559 |
|
* Forks the given tasks, returning when {@code isDone} holds for |
560 |
|
* each task or an (unchecked) exception is encountered, in which |
561 |
< |
* case the exception is rethrown. If more than one task |
562 |
< |
* encounters an exception, then this method throws any one of |
563 |
< |
* these exceptions. The individual status of each task may be |
561 |
> |
* case the exception is rethrown. If either task encounters an |
562 |
> |
* exception, the other one may be, but is not guaranteed to be, |
563 |
> |
* cancelled. If both tasks throw an exception, then this method |
564 |
> |
* throws one of them. The individual status of each task may be |
565 |
|
* checked using {@link #getException()} and related methods. |
566 |
|
* |
567 |
|
* <p>This method may be invoked only from within {@code |
724 |
|
return (status & COMPLETION_MASK) == CANCELLED; |
725 |
|
} |
726 |
|
|
727 |
– |
/** |
728 |
– |
* Returns {@code true} if the computation performed by this task |
729 |
– |
* has completed (or has been cancelled). |
730 |
– |
* |
731 |
– |
* @return {@code true} if this computation has completed |
732 |
– |
*/ |
727 |
|
public final boolean isDone() { |
728 |
|
return status < 0; |
729 |
|
} |
730 |
|
|
737 |
– |
/** |
738 |
– |
* Returns {@code true} if this task was cancelled. |
739 |
– |
* |
740 |
– |
* @return {@code true} if this task was cancelled |
741 |
– |
*/ |
731 |
|
public final boolean isCancelled() { |
732 |
|
return (status & COMPLETION_MASK) == CANCELLED; |
733 |
|
} |
753 |
|
} |
754 |
|
|
755 |
|
/** |
767 |
– |
* Returns {@code true} if this task threw an exception. |
768 |
– |
* |
769 |
– |
* @return {@code true} if this task threw an exception |
770 |
– |
*/ |
771 |
– |
public final boolean isCompletedExceptionally() { |
772 |
– |
return (status & COMPLETION_MASK) == EXCEPTIONAL; |
773 |
– |
} |
774 |
– |
|
775 |
– |
/** |
756 |
|
* Returns the exception thrown by the base computation, or a |
757 |
|
* {@code CancellationException} if cancelled, or {@code null} if |
758 |
|
* none or if the method has not yet completed. |
825 |
|
} |
826 |
|
|
827 |
|
/** |
828 |
< |
* Possibly executes other tasks until this task is ready, then |
829 |
< |
* returns the result of the computation. This method may be more |
830 |
< |
* efficient than {@code join}, but is only applicable when |
831 |
< |
* there are no potential dependencies between continuation of the |
832 |
< |
* current task and that of any other task that might be executed |
833 |
< |
* while helping. (This usually holds for pure divide-and-conquer |
834 |
< |
* tasks). |
828 |
> |
* Possibly executes other tasks until this task {@link #isDone is |
829 |
> |
* done}, then returns the result of the computation. This method |
830 |
> |
* may be more efficient than {@code join}, but is only applicable |
831 |
> |
* when there are no potential dependencies between continuation |
832 |
> |
* of the current task and that of any other task that might be |
833 |
> |
* executed while helping. (This usually holds for pure |
834 |
> |
* divide-and-conquer tasks). |
835 |
|
* |
836 |
|
* <p>This method may be invoked only from within {@code |
837 |
|
* ForkJoinTask} computations (as may be determined using method |
849 |
|
} |
850 |
|
|
851 |
|
/** |
852 |
< |
* Possibly executes other tasks until this task is ready. This |
853 |
< |
* method may be useful when processing collections of tasks when |
854 |
< |
* some have been cancelled or otherwise known to have aborted. |
852 |
> |
* Possibly executes other tasks until this task {@link #isDone is |
853 |
> |
* done}. This method may be useful when processing collections |
854 |
> |
* of tasks when some have been cancelled or otherwise known to |
855 |
> |
* have aborted. |
856 |
|
* |
857 |
|
* <p>This method may be invoked only from within {@code |
858 |
|
* ForkJoinTask} computations (as may be determined using method |