| 68 |
|
* execute other tasks while awaiting joins, which is sometimes more |
| 69 |
|
* efficient but only applies when all subtasks are known to be |
| 70 |
|
* strictly tree-structured. Method {@link #invoke} is semantically |
| 71 |
< |
* equivalent to {@code fork(); join()} but always attempts to |
| 72 |
< |
* begin execution in the current thread. The "<em>quiet</em>" forms |
| 73 |
< |
* of these methods do not extract results or report exceptions. These |
| 71 |
> |
* equivalent to {@code fork(); join()} but always attempts to begin |
| 72 |
> |
* execution in the current thread. The "<em>quiet</em>" forms of |
| 73 |
> |
* these methods do not extract results or report exceptions. These |
| 74 |
|
* may be useful when a set of tasks are being executed, and you need |
| 75 |
|
* to delay processing of results or exceptions until all complete. |
| 76 |
|
* Method {@code invokeAll} (available in multiple versions) |
| 77 |
|
* performs the most common form of parallel invocation: forking a set |
| 78 |
|
* of tasks and joining them all. |
| 79 |
|
* |
| 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; |
| 84 |
+ |
* {@link #isCompletedNormally} is true if a task completed without |
| 85 |
+ |
* cancellation or encountering an exception; {@link |
| 86 |
+ |
* #isCompletedExceptionally} is true if if the task encountered an |
| 87 |
+ |
* exception (in which case {@link #getException} returns the |
| 88 |
+ |
* exception); {@link #isCancelled} is true if the task was cancelled |
| 89 |
+ |
* (in which case {@link #getException} returns a {@link |
| 90 |
+ |
* java.util.concurrent.CancellationException}); and {@link |
| 91 |
+ |
* #isCompletedAbnormally} is true if a task was either cancelled or |
| 92 |
+ |
* encountered an exception. |
| 93 |
+ |
* |
| 94 |
|
* <p>The ForkJoinTask class is not usually directly subclassed. |
| 95 |
|
* Instead, you subclass one of the abstract classes that support a |
| 96 |
|
* particular style of fork/join processing, typically {@link |
| 125 |
|
* improve throughput. If too small, then memory and internal task |
| 126 |
|
* maintenance overhead may overwhelm processing. |
| 127 |
|
* |
| 128 |
< |
* <p>This class provides {@code adapt} methods for {@link |
| 129 |
< |
* java.lang.Runnable} and {@link java.util.concurrent.Callable}, that |
| 130 |
< |
* may be of use when mixing execution of ForkJoinTasks with other |
| 131 |
< |
* kinds of tasks. When all tasks are of this form, consider using a |
| 132 |
< |
* pool in {@link ForkJoinPool#setAsyncMode async mode}. |
| 128 |
> |
* <p>This class provides {@code adapt} methods for {@link Runnable} |
| 129 |
> |
* and {@link Callable}, that may be of use when mixing execution of |
| 130 |
> |
* {@code ForkJoinTasks} with other kinds of tasks. When all tasks |
| 131 |
> |
* are of this form, consider using a pool in |
| 132 |
> |
* {@linkplain ForkJoinPool#setAsyncMode async mode}. |
| 133 |
|
* |
| 134 |
|
* <p>ForkJoinTasks are {@code Serializable}, which enables them to be |
| 135 |
|
* used in extensions such as remote execution frameworks. It is |
| 392 |
|
|
| 393 |
|
/** |
| 394 |
|
* Returns result or throws exception using j.u.c.Future conventions. |
| 395 |
< |
* Only call when {@code isDone} known to be true. |
| 395 |
> |
* Only call when {@code isDone} known to be true or thread known |
| 396 |
> |
* to be interrupted. |
| 397 |
|
*/ |
| 398 |
|
private V reportFutureResult() |
| 399 |
< |
throws ExecutionException, InterruptedException { |
| 399 |
> |
throws InterruptedException, ExecutionException { |
| 400 |
|
if (Thread.interrupted()) |
| 401 |
|
throw new InterruptedException(); |
| 402 |
|
int s = status & COMPLETION_MASK; |
| 422 |
|
int s = status & COMPLETION_MASK; |
| 423 |
|
if (s == NORMAL) |
| 424 |
|
return getRawResult(); |
| 425 |
< |
if (s == CANCELLED) |
| 425 |
> |
else if (s == CANCELLED) |
| 426 |
|
throw new CancellationException(); |
| 427 |
< |
if (s == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
| 427 |
> |
else if (s == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
| 428 |
|
throw new ExecutionException(ex); |
| 429 |
< |
throw new TimeoutException(); |
| 429 |
> |
else |
| 430 |
> |
throw new TimeoutException(); |
| 431 |
|
} |
| 432 |
|
|
| 433 |
|
// internal execution methods |
| 560 |
|
/** |
| 561 |
|
* Forks the given tasks, returning when {@code isDone} holds for |
| 562 |
|
* each task or an (unchecked) exception is encountered, in which |
| 563 |
< |
* case the exception is rethrown. If more than one task |
| 564 |
< |
* encounters an exception, then this method throws any one of |
| 565 |
< |
* these exceptions. The individual status of each task may be |
| 563 |
> |
* case the exception is rethrown. If either task encounters an |
| 564 |
> |
* exception, the other one may be, but is not guaranteed to be, |
| 565 |
> |
* cancelled. If both tasks throw an exception, then this method |
| 566 |
> |
* throws one of them. The individual status of each task may be |
| 567 |
|
* checked using {@link #getException()} and related methods. |
| 568 |
|
* |
| 569 |
|
* <p>This method may be invoked only from within {@code |
| 783 |
|
*/ |
| 784 |
|
public final Throwable getException() { |
| 785 |
|
int s = status & COMPLETION_MASK; |
| 786 |
< |
if (s >= NORMAL) |
| 787 |
< |
return null; |
| 788 |
< |
if (s == CANCELLED) |
| 772 |
< |
return new CancellationException(); |
| 773 |
< |
return exceptionMap.get(this); |
| 786 |
> |
return ((s >= NORMAL) ? null : |
| 787 |
> |
(s == CANCELLED) ? new CancellationException() : |
| 788 |
> |
exceptionMap.get(this)); |
| 789 |
|
} |
| 790 |
|
|
| 791 |
|
/** |
