| 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 |
| 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. |
| 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 |
