33 |
|
* <p>A "main" {@code ForkJoinTask} begins execution when it is |
34 |
|
* explicitly submitted to a {@link ForkJoinPool}, or, if not already |
35 |
|
* engaged in a ForkJoin computation, commenced in the {@link |
36 |
< |
* ForkJoinPool#commonPool} via {@link #fork}, {@link #invoke}, or |
36 |
> |
* ForkJoinPool#commonPool()} via {@link #fork}, {@link #invoke}, or |
37 |
|
* related methods. Once started, it will usually in turn start other |
38 |
|
* subtasks. As indicated by the name of this class, many programs |
39 |
|
* using {@code ForkJoinTask} employ only methods {@link #fork} and |
55 |
|
* minimize other blocking synchronization apart from joining other |
56 |
|
* tasks or using synchronizers such as Phasers that are advertised to |
57 |
|
* cooperate with fork/join scheduling. Subdividable tasks should also |
58 |
< |
* not perform blocking IO, and should ideally access variables that |
58 |
> |
* not perform blocking I/O, and should ideally access variables that |
59 |
|
* are completely independent of those accessed by other running |
60 |
|
* tasks. These guidelines are loosely enforced by not permitting |
61 |
|
* checked exceptions such as {@code IOExceptions} to be |
73 |
|
* <p>It is possible to define and use ForkJoinTasks that may block, |
74 |
|
* but doing do requires three further considerations: (1) Completion |
75 |
|
* of few if any <em>other</em> tasks should be dependent on a task |
76 |
< |
* that blocks on external synchronization or IO. Event-style async |
76 |
> |
* that blocks on external synchronization or I/O. Event-style async |
77 |
|
* tasks that are never joined (for example, those subclassing {@link |
78 |
|
* CountedCompleter}) often fall into this category. (2) To minimize |
79 |
|
* resource impact, tasks should be small; ideally performing only the |
435 |
|
} |
436 |
|
|
437 |
|
/** |
438 |
< |
* Records exception and possibly propagates |
438 |
> |
* Records exception and possibly propagates. |
439 |
|
* |
440 |
|
* @return status on exit |
441 |
|
*/ |
635 |
|
/** |
636 |
|
* Arranges to asynchronously execute this task in the pool the |
637 |
|
* current task is running in, if applicable, or using the {@link |
638 |
< |
* ForkJoinPool#commonPool} if not {@link #inForkJoinPool}. While |
638 |
> |
* ForkJoinPool#commonPool()} if not {@link #inForkJoinPool}. While |
639 |
|
* it is not necessarily enforced, it is a usage error to fork a |
640 |
|
* task more than once unless it has completed and been |
641 |
|
* reinitialized. Subsequent modifications to the state of this |
978 |
|
if (Thread.interrupted()) |
979 |
|
throw new InterruptedException(); |
980 |
|
// Messy in part because we measure in nanosecs, but wait in millisecs |
981 |
< |
int s; long ns, ms; |
982 |
< |
if ((s = status) >= 0 && (ns = unit.toNanos(timeout)) > 0L) { |
981 |
> |
int s; long ms; |
982 |
> |
long ns = unit.toNanos(timeout); |
983 |
> |
if ((s = status) >= 0 && ns > 0L) { |
984 |
|
long deadline = System.nanoTime() + ns; |
985 |
|
ForkJoinPool p = null; |
986 |
|
ForkJoinPool.WorkQueue w = null; |
1501 |
|
} |
1502 |
|
} |
1503 |
|
} |
1504 |
+ |
|
1505 |
|
} |