19 |
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* |
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* <ul> |
21 |
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* |
22 |
< |
* <li> The number of parties synchronizing on a phaser may vary over |
23 |
< |
* time. A task may register to be a party at any time, and may |
24 |
< |
* deregister upon arriving at the barrier. As is the case with most |
25 |
< |
* basic synchronization constructs, registration and deregistration |
26 |
< |
* affect only internal counts; they do not establish any further |
27 |
< |
* internal bookkeeping, so tasks cannot query whether they are |
22 |
> |
* <li> The number of parties <em>registered</em> to synchronize on a |
23 |
> |
* phaser may vary over time. Tasks may be registered at any time |
24 |
> |
* (using methods {@link #register}, {@link #bulkRegister}, or forms |
25 |
> |
* of constructors establishing initial numbers of parties), and may |
26 |
> |
* optionally be deregistered upon any arrival (using {@link |
27 |
> |
* #arriveAndDeregister}). As is the case with most basic |
28 |
> |
* synchronization constructs, registration and deregistration affect |
29 |
> |
* only internal counts; they do not establish any further internal |
30 |
> |
* bookkeeping, so tasks cannot query whether they are |
31 |
|
* registered. (However, you can introduce such bookkeeping by |
32 |
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* subclassing this class.) |
33 |
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* |
34 |
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* <li> Each generation has an associated phase value, starting at |
35 |
< |
* zero, and advancing when all parties reach the barrier (wrapping |
36 |
< |
* around to zero after reaching {@code Integer.MAX_VALUE}). |
35 |
> |
* zero, and advancing when all parties arrive at the barrier |
36 |
> |
* (wrapping around to zero after reaching {@code Integer.MAX_VALUE}). |
37 |
|
* |
38 |
|
* <li> Like a {@code CyclicBarrier}, a phaser may be repeatedly |
39 |
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* awaited. Method {@link #arriveAndAwaitAdvance} has effect |
45 |
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* |
46 |
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* <li> Arriving at a barrier. Methods {@link #arrive} and |
47 |
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* {@link #arriveAndDeregister} do not block, but return |
48 |
< |
* the phase value current upon entry to the method. |
48 |
> |
* an associated <em>arrival phase number</em>; |
49 |
> |
* that is, the phase number of the barrier to which the |
50 |
> |
* arrival applied. |
51 |
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* |
52 |
|
* <li> Awaiting others. Method {@link #awaitAdvance} requires an |
53 |
< |
* argument indicating the entry phase, and returns when the |
54 |
< |
* barrier advances to a new phase. |
53 |
> |
* argument indicating an arrival phase number, and returns |
54 |
> |
* when the barrier advances to a new phase. |
55 |
|
* </ul> |
56 |
|
* |
57 |
|
* |
371 |
|
/** |
372 |
|
* Adds a new unarrived party to this phaser. |
373 |
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* |
374 |
< |
* @return the current barrier phase number upon registration |
374 |
> |
* @return the arrival phase number to which this registration applied |
375 |
|
* @throws IllegalStateException if attempting to register more |
376 |
|
* than the maximum supported number of parties |
377 |
|
*/ |
383 |
|
* Adds the given number of new unarrived parties to this phaser. |
384 |
|
* |
385 |
|
* @param parties the number of parties required to trip barrier |
386 |
< |
* @return the current barrier phase number upon registration |
386 |
> |
* @return the arrival phase number to which this registration applied |
387 |
|
* @throws IllegalStateException if attempting to register more |
388 |
|
* than the maximum supported number of parties |
389 |
|
*/ |
420 |
|
* Arrives at the barrier, but does not wait for others. (You can |
421 |
|
* in turn wait for others via {@link #awaitAdvance}). |
422 |
|
* |
423 |
< |
* @return the barrier phase number upon entry to this method, or a |
419 |
< |
* negative value if terminated |
423 |
> |
* @return the arrival phase number, or a negative value if terminated |
424 |
|
* @throws IllegalStateException if not terminated and the number |
425 |
|
* of unarrived parties would become negative |
426 |
|
*/ |
472 |
|
* zero parties, this phaser also arrives at and is deregistered |
473 |
|
* from its parent. |
474 |
|
* |
475 |
< |
* @return the current barrier phase number upon entry to |
472 |
< |
* this method, or a negative value if terminated |
475 |
> |
* @return the arrival phase number, or a negative value if terminated |
476 |
|
* @throws IllegalStateException if not terminated and the number |
477 |
|
* of registered or unarrived parties would become negative |
478 |
|
*/ |
528 |
|
* method. If instead you need to deregister upon arrival use |
529 |
|
* {@code arriveAndDeregister}. |
530 |
|
* |
531 |
< |
* @return the phase on entry to this method |
531 |
> |
* @return the arrival phase number, or a negative number if terminated |
532 |
|
* @throws IllegalStateException if not terminated and the number |
533 |
|
* of unarrived parties would become negative |
534 |
|
*/ |
542 |
|
* barrier is not equal to the given phase value or this barrier |
543 |
|
* is terminated. |
544 |
|
* |
545 |
< |
* @param phase the phase on entry to this method |
546 |
< |
* @return the phase on exit from this method |
545 |
> |
* @param phase an arrival phase number, or negative value if |
546 |
> |
* terminated; this argument is normally the value returned by a |
547 |
> |
* previous call to {@code arrive} or its variants |
548 |
> |
* @return the next arrival phase number, or a negative value |
549 |
> |
* if terminated or argument is negative |
550 |
|
*/ |
551 |
|
public int awaitAdvance(int phase) { |
552 |
|
if (phase < 0) |
568 |
|
* barrier is not equal to the given phase value or this barrier |
569 |
|
* is terminated. |
570 |
|
* |
571 |
< |
* @param phase the phase on entry to this method |
572 |
< |
* @return the phase on exit from this method |
571 |
> |
* @param phase an arrival phase number, or negative value if |
572 |
> |
* terminated; this argument is normally the value returned by a |
573 |
> |
* previous call to {@code arrive} or its variants |
574 |
> |
* @return the next arrival phase number, or a negative value |
575 |
> |
* if terminated or argument is negative |
576 |
|
* @throws InterruptedException if thread interrupted while waiting |
577 |
|
*/ |
578 |
|
public int awaitAdvanceInterruptibly(int phase) |
595 |
|
* returning immediately if the current phase of the barrier is not |
596 |
|
* equal to the given phase value or this barrier is terminated. |
597 |
|
* |
598 |
< |
* @param phase the phase on entry to this method |
598 |
> |
* @param phase an arrival phase number, or negative value if |
599 |
> |
* terminated; this argument is normally the value returned by a |
600 |
> |
* previous call to {@code arrive} or its variants |
601 |
|
* @param timeout how long to wait before giving up, in units of |
602 |
|
* {@code unit} |
603 |
|
* @param unit a {@code TimeUnit} determining how to interpret the |
604 |
|
* {@code timeout} parameter |
605 |
< |
* @return the phase on exit from this method |
605 |
> |
* @return the next arrival phase number, or a negative value |
606 |
> |
* if terminated or argument is negative |
607 |
|
* @throws InterruptedException if thread interrupted while waiting |
608 |
|
* @throws TimeoutException if timed out while waiting |
609 |
|
*/ |