183 |
|
* }}</pre> |
184 |
|
* |
185 |
|
* |
186 |
< |
* <p>To create a set of tasks using a tree of phasers, |
187 |
< |
* you could use code of the following form, assuming a |
188 |
< |
* Task class with a constructor accepting a {@code Phaser} that |
189 |
< |
* it registers with upon construction: |
186 |
> |
* <p>To create a set of {@code n} tasks using a tree of phasers, you |
187 |
> |
* could use code of the following form, assuming a Task class with a |
188 |
> |
* constructor accepting a {@code Phaser} that it registers with upon |
189 |
> |
* construction. After invocation of {@code build(new Task[n], 0, n, |
190 |
> |
* new Phaser())}, these tasks could then be started, for example by |
191 |
> |
* submitting to a pool: |
192 |
|
* |
193 |
|
* <pre> {@code |
194 |
< |
* void build(Task[] actions, int lo, int hi, Phaser ph) { |
194 |
> |
* void build(Task[] tasks, int lo, int hi, Phaser ph) { |
195 |
|
* if (hi - lo > TASKS_PER_PHASER) { |
196 |
|
* for (int i = lo; i < hi; i += TASKS_PER_PHASER) { |
197 |
|
* int j = Math.min(i + TASKS_PER_PHASER, hi); |
198 |
< |
* build(actions, i, j, new Phaser(ph)); |
198 |
> |
* build(tasks, i, j, new Phaser(ph)); |
199 |
|
* } |
200 |
|
* } else { |
201 |
|
* for (int i = lo; i < hi; ++i) |
202 |
< |
* actions[i] = new Task(ph); |
202 |
> |
* tasks[i] = new Task(ph); |
203 |
|
* // assumes new Task(ph) performs ph.register() |
204 |
|
* } |
205 |
< |
* } |
204 |
< |
* // .. initially called, for n tasks via |
205 |
< |
* build(new Task[n], 0, n, new Phaser());}</pre> |
205 |
> |
* }}</pre> |
206 |
|
* |
207 |
|
* The best value of {@code TASKS_PER_PHASER} depends mainly on |
208 |
|
* expected synchronization rates. A value as low as four may |
233 |
|
* * phase -- the generation of the barrier (bits 32-62) |
234 |
|
* * terminated -- set if barrier is terminated (bit 63 / sign) |
235 |
|
* |
236 |
< |
* However, to efficiently maintain atomicity, these values are |
237 |
< |
* packed into a single (atomic) long. Termination uses the sign |
238 |
< |
* bit of 32 bit representation of phase, so phase is set to -1 on |
239 |
< |
* termination. Good performance relies on keeping state decoding |
240 |
< |
* and encoding simple, and keeping race windows short. |
236 |
> |
* Except that a phaser with no registered parties is |
237 |
> |
* distinguished with the otherwise illegal state of having zero |
238 |
> |
* parties and one unarrived parties (encoded as EMPTY below). |
239 |
> |
* |
240 |
> |
* To efficiently maintain atomicity, these values are packed into |
241 |
> |
* a single (atomic) long. Good performance relies on keeping |
242 |
> |
* state decoding and encoding simple, and keeping race windows |
243 |
> |
* short. |
244 |
> |
* |
245 |
> |
* All state updates are performed via CAS except initial |
246 |
> |
* registration of a sub-phaser (i.e., one with a non-null |
247 |
> |
* parent). In this (relatively rare) case, we use built-in |
248 |
> |
* synchronization to lock while first registering with its |
249 |
> |
* parent. |
250 |
> |
* |
251 |
> |
* The phase of a subphaser is allowed to lag that of its |
252 |
> |
* ancestors until it is actually accessed. Method reconcileState |
253 |
> |
* is usually attempted only only when the number of unarrived |
254 |
> |
* parties appears to be zero, which indicates a potential lag in |
255 |
> |
* updating phase after the root advanced. |
256 |
|
*/ |
257 |
|
private volatile long state; |
258 |
|
|
262 |
|
private static final int PHASE_SHIFT = 32; |
263 |
|
private static final int UNARRIVED_MASK = 0xffff; // to mask ints |
264 |
|
private static final long PARTIES_MASK = 0xffff0000L; // to mask longs |
250 |
– |
private static final long ONE_ARRIVAL = 1L; |
251 |
– |
private static final long ONE_PARTY = 1L << PARTIES_SHIFT; |
265 |
|
private static final long TERMINATION_BIT = 1L << 63; |
266 |
|
|
267 |
+ |
// some special values |
268 |
+ |
private static final int ONE_ARRIVAL = 1; |
269 |
+ |
private static final int ONE_PARTY = 1 << PARTIES_SHIFT; |
270 |
+ |
private static final int EMPTY = 1; |
271 |
+ |
|
272 |
|
// The following unpacking methods are usually manually inlined |
273 |
|
|
274 |
|
private static int unarrivedOf(long s) { |
275 |
< |
return (int)s & UNARRIVED_MASK; |
275 |
> |
int counts = (int)s; |
276 |
> |
return (counts == EMPTY)? 0 : counts & UNARRIVED_MASK; |
277 |
|
} |
278 |
|
|
279 |
|
private static int partiesOf(long s) { |
280 |
< |
return (int)s >>> PARTIES_SHIFT; |
280 |
> |
int counts = (int)s; |
281 |
> |
return (counts == EMPTY)? 0 : counts >>> PARTIES_SHIFT; |
282 |
|
} |
283 |
|
|
284 |
|
private static int phaseOf(long s) { |
286 |
|
} |
287 |
|
|
288 |
|
private static int arrivedOf(long s) { |
289 |
< |
return partiesOf(s) - unarrivedOf(s); |
289 |
> |
int counts = (int)s; |
290 |
> |
return (counts == EMPTY)? 0 : |
291 |
> |
(counts >>> PARTIES_SHIFT) - (counts & UNARRIVED_MASK); |
292 |
|
} |
293 |
|
|
294 |
|
/** |
297 |
|
private final Phaser parent; |
298 |
|
|
299 |
|
/** |
300 |
< |
* The root of phaser tree. Equals this if not in a tree. Used to |
279 |
< |
* support faster state push-down. |
300 |
> |
* The root of phaser tree. Equals this if not in a tree. |
301 |
|
*/ |
302 |
|
private final Phaser root; |
303 |
|
|
335 |
|
* Manually tuned to speed up and minimize race windows for the |
336 |
|
* common case of just decrementing unarrived field. |
337 |
|
* |
338 |
< |
* @param adj - adjustment to apply to state -- either |
318 |
< |
* ONE_ARRIVAL (for arrive) or |
319 |
< |
* ONE_ARRIVAL|ONE_PARTY (for arriveAndDeregister) |
338 |
> |
* @param deregister false for arrive, true for arriveAndDeregister |
339 |
|
*/ |
340 |
< |
private int doArrive(long adj) { |
341 |
< |
for (;;) { |
342 |
< |
long s = state; |
343 |
< |
int unarrived = (int)s & UNARRIVED_MASK; |
344 |
< |
int phase = (int)(s >>> PHASE_SHIFT); |
345 |
< |
if (phase < 0) |
346 |
< |
return phase; |
347 |
< |
else if (unarrived == 0) { |
348 |
< |
if (reconcileState() == s) // recheck |
340 |
> |
private int doArrive(boolean deregister) { |
341 |
> |
int adj = deregister ? ONE_ARRIVAL|ONE_PARTY : ONE_ARRIVAL; |
342 |
> |
long s; |
343 |
> |
int phase; |
344 |
> |
while ((phase = (int)((s = state) >>> PHASE_SHIFT)) >= 0) { |
345 |
> |
int counts = (int)s; |
346 |
> |
int unarrived = counts & UNARRIVED_MASK; |
347 |
> |
if (counts == EMPTY || unarrived == 0) { |
348 |
> |
if (reconcileState() == s) |
349 |
|
throw new IllegalStateException(badArrive(s)); |
350 |
|
} |
351 |
|
else if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s-=adj)) { |
352 |
|
if (unarrived == 1) { |
353 |
< |
long p = s & PARTIES_MASK; // unshifted parties field |
354 |
< |
long lu = p >>> PARTIES_SHIFT; |
355 |
< |
int u = (int)lu; |
356 |
< |
int nextPhase = (phase + 1) & MAX_PHASE; |
357 |
< |
long next = ((long)nextPhase << PHASE_SHIFT) | p | lu; |
358 |
< |
final Phaser parent = this.parent; |
340 |
< |
if (parent == null) { |
341 |
< |
if (onAdvance(phase, u)) |
342 |
< |
next |= TERMINATION_BIT; |
343 |
< |
UNSAFE.compareAndSwapLong(this, stateOffset, s, next); |
344 |
< |
releaseWaiters(phase); |
353 |
> |
long n = s & PARTIES_MASK; // unshifted parties field |
354 |
> |
int u = ((int)n) >>> PARTIES_SHIFT; |
355 |
> |
Phaser par = parent; |
356 |
> |
if (par != null) { |
357 |
> |
par.doArrive(u == 0); |
358 |
> |
reconcileState(); |
359 |
|
} |
360 |
|
else { |
361 |
< |
parent.doArrive((u == 0) ? |
362 |
< |
ONE_ARRIVAL|ONE_PARTY : ONE_ARRIVAL); |
363 |
< |
if ((int)(parent.state >>> PHASE_SHIFT) != nextPhase) |
364 |
< |
reconcileState(); |
365 |
< |
else if (state == s) |
366 |
< |
UNSAFE.compareAndSwapLong(this, stateOffset, s, |
367 |
< |
next); |
361 |
> |
n |= (((long)((phase+1) & MAX_PHASE)) << PHASE_SHIFT); |
362 |
> |
if (onAdvance(phase, u)) |
363 |
> |
n |= TERMINATION_BIT; |
364 |
> |
else if (u == 0) |
365 |
> |
n |= EMPTY; // reset to unregistered |
366 |
> |
else |
367 |
> |
n |= (long)u; // reset unarr to parties |
368 |
> |
// assert state == s || isTerminated(); |
369 |
> |
UNSAFE.compareAndSwapLong(this, stateOffset, s, n); |
370 |
> |
releaseWaiters(phase); |
371 |
|
} |
372 |
|
} |
373 |
< |
return phase; |
373 |
> |
break; |
374 |
|
} |
375 |
|
} |
376 |
+ |
return phase; |
377 |
|
} |
378 |
|
|
379 |
|
/** |
385 |
|
private int doRegister(int registrations) { |
386 |
|
// adjustment to state |
387 |
|
long adj = ((long)registrations << PARTIES_SHIFT) | registrations; |
388 |
< |
final Phaser parent = this.parent; |
388 |
> |
Phaser par = parent; |
389 |
> |
int phase; |
390 |
|
for (;;) { |
391 |
< |
long s = (parent == null) ? state : reconcileState(); |
392 |
< |
int parties = (int)s >>> PARTIES_SHIFT; |
393 |
< |
int phase = (int)(s >>> PHASE_SHIFT); |
394 |
< |
if (phase < 0) |
395 |
< |
return phase; |
377 |
< |
else if (registrations > MAX_PARTIES - parties) |
391 |
> |
long s = state; |
392 |
> |
int counts = (int)s; |
393 |
> |
int parties = counts >>> PARTIES_SHIFT; |
394 |
> |
int unarrived = counts & UNARRIVED_MASK; |
395 |
> |
if (registrations > MAX_PARTIES - parties) |
396 |
|
throw new IllegalStateException(badRegister(s)); |
397 |
< |
else if ((parties == 0 && parent == null) || // first reg of root |
398 |
< |
((int)s & UNARRIVED_MASK) != 0) { // not advancing |
399 |
< |
if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s + adj)) |
400 |
< |
return phase; |
401 |
< |
} |
402 |
< |
else if (parties != 0) // wait for onAdvance |
403 |
< |
root.internalAwaitAdvance(phase, null); |
404 |
< |
else { // 1st registration of child |
405 |
< |
synchronized (this) { // register parent first |
406 |
< |
if (reconcileState() == s) { // recheck under lock |
407 |
< |
parent.doRegister(1); // OK if throws IllegalState |
408 |
< |
for (;;) { // simpler form of outer loop |
409 |
< |
s = reconcileState(); |
410 |
< |
phase = (int)(s >>> PHASE_SHIFT); |
411 |
< |
if (phase < 0 || |
412 |
< |
UNSAFE.compareAndSwapLong(this, stateOffset, |
413 |
< |
s, s + adj)) |
414 |
< |
return phase; |
415 |
< |
} |
397 |
> |
else if ((phase = (int)(s >>> PHASE_SHIFT)) < 0) |
398 |
> |
break; |
399 |
> |
else if (counts != EMPTY) { // not 1st registration |
400 |
> |
if (par == null || reconcileState() == s) { |
401 |
> |
if (unarrived == 0) // wait out advance |
402 |
> |
root.internalAwaitAdvance(phase, null); |
403 |
> |
else if (UNSAFE.compareAndSwapLong(this, stateOffset, |
404 |
> |
s, s + adj)) |
405 |
> |
break; |
406 |
> |
} |
407 |
> |
} |
408 |
> |
else if (par == null) { // 1st root registration |
409 |
> |
long next = (((long) phase) << PHASE_SHIFT) | adj; |
410 |
> |
if (UNSAFE.compareAndSwapLong(this, stateOffset, s, next)) |
411 |
> |
break; |
412 |
> |
} |
413 |
> |
else { |
414 |
> |
synchronized(this) { // 1st sub registration |
415 |
> |
if (state == s) { // recheck under lock |
416 |
> |
par.doRegister(1); |
417 |
> |
do { // force current phase |
418 |
> |
phase = (int)(root.state >>> PHASE_SHIFT); |
419 |
> |
// assert phase < 0 || (int)state == EMPTY; |
420 |
> |
} while (!UNSAFE.compareAndSwapLong |
421 |
> |
(this, stateOffset, state, |
422 |
> |
(((long) phase) << PHASE_SHIFT) | adj)); |
423 |
> |
break; |
424 |
|
} |
425 |
|
} |
426 |
|
} |
427 |
|
} |
428 |
+ |
return phase; |
429 |
|
} |
430 |
|
|
431 |
|
/** |
432 |
< |
* Recursively resolves lagged phase propagation from root if necessary. |
432 |
> |
* Resolves lagged phase propagation from root if necessary. |
433 |
|
*/ |
434 |
|
private long reconcileState() { |
435 |
< |
Phaser par = parent; |
435 |
> |
Phaser rt = root; |
436 |
|
long s = state; |
437 |
< |
if (par != null) { |
438 |
< |
Phaser rt = root; |
439 |
< |
int phase, rPhase; |
440 |
< |
while ((phase = (int)(s >>> PHASE_SHIFT)) >= 0 && |
441 |
< |
(rPhase = (int)(rt.state >>> PHASE_SHIFT)) != phase) { |
442 |
< |
if (par != rt && (int)(par.state >>> PHASE_SHIFT) != rPhase) |
443 |
< |
par.reconcileState(); |
444 |
< |
else if (rPhase < 0 || ((int)s & UNARRIVED_MASK) == 0) { |
445 |
< |
long u = s & PARTIES_MASK; // reset unarrived to parties |
446 |
< |
long next = ((((long) rPhase) << PHASE_SHIFT) | u | |
447 |
< |
(u >>> PARTIES_SHIFT)); |
448 |
< |
UNSAFE.compareAndSwapLong(this, stateOffset, s, next); |
437 |
> |
if (rt != this) { |
438 |
> |
int phase; |
439 |
> |
while ((phase = (int)(rt.state >>> PHASE_SHIFT)) != |
440 |
> |
(int)(s >>> PHASE_SHIFT)) { |
441 |
> |
// assert phase < 0 || unarrivedOf(s) == 0 |
442 |
> |
long t; // to reread s |
443 |
> |
long p = s & PARTIES_MASK; // unshifted parties field |
444 |
> |
long n = (((long) phase) << PHASE_SHIFT) | p; |
445 |
> |
if (phase >= 0) { |
446 |
> |
if (p == 0L) |
447 |
> |
n |= EMPTY; // reset to empty |
448 |
> |
else |
449 |
> |
n |= p >>> PARTIES_SHIFT; // set unarr to parties |
450 |
|
} |
451 |
< |
s = state; |
451 |
> |
if ((t = state) == s && |
452 |
> |
UNSAFE.compareAndSwapLong(this, stateOffset, s, s = n)) |
453 |
> |
break; |
454 |
> |
s = t; |
455 |
|
} |
456 |
|
} |
457 |
|
return s; |
509 |
|
public Phaser(Phaser parent, int parties) { |
510 |
|
if (parties >>> PARTIES_SHIFT != 0) |
511 |
|
throw new IllegalArgumentException("Illegal number of parties"); |
512 |
< |
long s = ((long) parties) | (((long) parties) << PARTIES_SHIFT); |
512 |
> |
int phase = 0; |
513 |
|
this.parent = parent; |
514 |
|
if (parent != null) { |
515 |
|
Phaser r = parent.root; |
517 |
|
this.evenQ = r.evenQ; |
518 |
|
this.oddQ = r.oddQ; |
519 |
|
if (parties != 0) |
520 |
< |
s |= ((long)(parent.doRegister(1))) << PHASE_SHIFT; |
520 |
> |
phase = parent.doRegister(1); |
521 |
|
} |
522 |
|
else { |
523 |
|
this.root = this; |
524 |
|
this.evenQ = new AtomicReference<QNode>(); |
525 |
|
this.oddQ = new AtomicReference<QNode>(); |
526 |
|
} |
527 |
< |
this.state = s; |
527 |
> |
this.state = (parties == 0)? ((long) EMPTY) : |
528 |
> |
((((long) phase) << PHASE_SHIFT) | |
529 |
> |
(((long) parties) << PARTIES_SHIFT) | |
530 |
> |
((long) parties)); |
531 |
|
} |
532 |
|
|
533 |
|
/** |
581 |
|
* of unarrived parties would become negative |
582 |
|
*/ |
583 |
|
public int arrive() { |
584 |
< |
return doArrive(ONE_ARRIVAL); |
584 |
> |
return doArrive(false); |
585 |
|
} |
586 |
|
|
587 |
|
/** |
601 |
|
* of registered or unarrived parties would become negative |
602 |
|
*/ |
603 |
|
public int arriveAndDeregister() { |
604 |
< |
return doArrive(ONE_ARRIVAL|ONE_PARTY); |
604 |
> |
return doArrive(true); |
605 |
|
} |
606 |
|
|
607 |
|
/** |
622 |
|
* of unarrived parties would become negative |
623 |
|
*/ |
624 |
|
public int arriveAndAwaitAdvance() { |
625 |
< |
return awaitAdvance(doArrive(ONE_ARRIVAL)); |
625 |
> |
return awaitAdvance(doArrive(false)); |
626 |
|
} |
627 |
|
|
628 |
|
/** |
641 |
|
int p = (int)(state >>> PHASE_SHIFT); |
642 |
|
if (phase < 0) |
643 |
|
return phase; |
644 |
< |
if (p == phase && |
645 |
< |
(p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) |
646 |
< |
return rt.internalAwaitAdvance(phase, null); |
644 |
> |
if (p == phase) { |
645 |
> |
if ((p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) |
646 |
> |
return rt.internalAwaitAdvance(phase, null); |
647 |
> |
reconcileState(); |
648 |
> |
} |
649 |
|
return p; |
650 |
|
} |
651 |
|
|
669 |
|
int p = (int)(state >>> PHASE_SHIFT); |
670 |
|
if (phase < 0) |
671 |
|
return phase; |
672 |
< |
if (p == phase && |
673 |
< |
(p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) { |
674 |
< |
QNode node = new QNode(this, phase, true, false, 0L); |
675 |
< |
p = rt.internalAwaitAdvance(phase, node); |
676 |
< |
if (node.wasInterrupted) |
677 |
< |
throw new InterruptedException(); |
672 |
> |
if (p == phase) { |
673 |
> |
if ((p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) { |
674 |
> |
QNode node = new QNode(this, phase, true, false, 0L); |
675 |
> |
p = rt.internalAwaitAdvance(phase, node); |
676 |
> |
if (node.wasInterrupted) |
677 |
> |
throw new InterruptedException(); |
678 |
> |
} |
679 |
> |
else |
680 |
> |
reconcileState(); |
681 |
|
} |
682 |
|
return p; |
683 |
|
} |
709 |
|
int p = (int)(state >>> PHASE_SHIFT); |
710 |
|
if (phase < 0) |
711 |
|
return phase; |
712 |
< |
if (p == phase && |
713 |
< |
(p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) { |
714 |
< |
QNode node = new QNode(this, phase, true, true, nanos); |
715 |
< |
p = rt.internalAwaitAdvance(phase, node); |
716 |
< |
if (node.wasInterrupted) |
717 |
< |
throw new InterruptedException(); |
718 |
< |
else if (p == phase) |
719 |
< |
throw new TimeoutException(); |
712 |
> |
if (p == phase) { |
713 |
> |
if ((p = (int)((rt = root).state >>> PHASE_SHIFT)) == phase) { |
714 |
> |
QNode node = new QNode(this, phase, true, true, nanos); |
715 |
> |
p = rt.internalAwaitAdvance(phase, node); |
716 |
> |
if (node.wasInterrupted) |
717 |
> |
throw new InterruptedException(); |
718 |
> |
else if (p == phase) |
719 |
> |
throw new TimeoutException(); |
720 |
> |
} |
721 |
> |
else |
722 |
> |
reconcileState(); |
723 |
|
} |
724 |
|
return p; |
725 |
|
} |
726 |
|
|
727 |
|
/** |
728 |
|
* Forces this phaser to enter termination state. Counts of |
729 |
< |
* arrived and registered parties are unaffected. If this phaser |
730 |
< |
* is a member of a tiered set of phasers, then all of the phasers |
731 |
< |
* in the set are terminated. If this phaser is already |
732 |
< |
* terminated, this method has no effect. This method may be |
733 |
< |
* useful for coordinating recovery after one or more tasks |
734 |
< |
* encounter unexpected exceptions. |
729 |
> |
* registered parties are unaffected. If this phaser is a member |
730 |
> |
* of a tiered set of phasers, then all of the phasers in the set |
731 |
> |
* are terminated. If this phaser is already terminated, this |
732 |
> |
* method has no effect. This method may be useful for |
733 |
> |
* coordinating recovery after one or more tasks encounter |
734 |
> |
* unexpected exceptions. |
735 |
|
*/ |
736 |
|
public void forceTermination() { |
737 |
|
// Only need to change root state |
738 |
|
final Phaser root = this.root; |
739 |
|
long s; |
740 |
|
while ((s = root.state) >= 0) { |
741 |
< |
if (UNSAFE.compareAndSwapLong(root, stateOffset, |
742 |
< |
s, s | TERMINATION_BIT)) { |
741 |
> |
long next = (s & ~(long)(MAX_PARTIES)) | TERMINATION_BIT; |
742 |
> |
if (UNSAFE.compareAndSwapLong(root, stateOffset, s, next)) { |
743 |
|
releaseWaiters(0); // signal all threads |
744 |
|
releaseWaiters(1); |
745 |
|
return; |
776 |
|
* @return the number of arrived parties |
777 |
|
*/ |
778 |
|
public int getArrivedParties() { |
779 |
< |
long s = state; |
738 |
< |
int u = unarrivedOf(s); // only reconcile if possibly needed |
739 |
< |
return (u != 0 || parent == null) ? |
740 |
< |
partiesOf(s) - u : |
741 |
< |
arrivedOf(reconcileState()); |
779 |
> |
return arrivedOf(reconcileState()); |
780 |
|
} |
781 |
|
|
782 |
|
/** |
786 |
|
* @return the number of unarrived parties |
787 |
|
*/ |
788 |
|
public int getUnarrivedParties() { |
789 |
< |
int u = unarrivedOf(state); |
752 |
< |
return (u != 0 || parent == null) ? u : unarrivedOf(reconcileState()); |
789 |
> |
return unarrivedOf(reconcileState()); |
790 |
|
} |
791 |
|
|
792 |
|
/** |
822 |
|
* advance, and to control termination. This method is invoked |
823 |
|
* upon arrival of the party advancing this phaser (when all other |
824 |
|
* waiting parties are dormant). If this method returns {@code |
825 |
< |
* true}, then, rather than advance the phase number, this phaser |
826 |
< |
* will be set to a final termination state, and subsequent calls |
827 |
< |
* to {@link #isTerminated} will return true. Any (unchecked) |
828 |
< |
* Exception or Error thrown by an invocation of this method is |
829 |
< |
* propagated to the party attempting to advance this phaser, in |
830 |
< |
* which case no advance occurs. |
825 |
> |
* true}, this phaser will be set to a final termination state |
826 |
> |
* upon advance, and subsequent calls to {@link #isTerminated} |
827 |
> |
* will return true. Any (unchecked) Exception or Error thrown by |
828 |
> |
* an invocation of this method is propagated to the party |
829 |
> |
* attempting to advance this phaser, in which case no advance |
830 |
> |
* occurs. |
831 |
|
* |
832 |
|
* <p>The arguments to this method provide the state of the phaser |
833 |
|
* prevailing for the current transition. The effects of invoking |
893 |
|
QNode q; // first element of queue |
894 |
|
int p; // its phase |
895 |
|
Thread t; // its thread |
896 |
+ |
// assert phase != phaseOf(root.state); |
897 |
|
AtomicReference<QNode> head = (phase & 1) == 0 ? evenQ : oddQ; |
898 |
|
while ((q = head.get()) != null && |
899 |
< |
((p = q.phase) == phase || |
862 |
< |
(int)(root.state >>> PHASE_SHIFT) != p)) { |
899 |
> |
q.phase != (int)(root.state >>> PHASE_SHIFT)) { |
900 |
|
if (head.compareAndSet(q, q.next) && |
901 |
|
(t = q.thread) != null) { |
902 |
|
q.thread = null; |
972 |
|
node.thread = null; // avoid need for unpark() |
973 |
|
if (node.wasInterrupted && !node.interruptible) |
974 |
|
Thread.currentThread().interrupt(); |
975 |
< |
if ((p = (int)(state >>> PHASE_SHIFT)) == phase) |
975 |
> |
if (p == phase && (p = (int)(state >>> PHASE_SHIFT)) == phase) |
976 |
|
return p; // recheck abort |
977 |
|
} |
978 |
|
releaseWaiters(phase); |