302 |
|
* ONE_ARRIVAL|ONE_PARTY (for arriveAndDeregister) |
303 |
|
*/ |
304 |
|
private int doArrive(long adj) { |
305 |
< |
long s; |
306 |
< |
int phase, unarrived; |
307 |
< |
while ((phase = (int)((s = state) >>> PHASE_SHIFT)) >= 0) { |
308 |
< |
if ((unarrived = (int)(s & UNARRIVED_MASK)) != 0) { |
309 |
< |
if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s -= adj)) { |
310 |
< |
if (unarrived == 1) { |
311 |
< |
Phaser par; |
312 |
< |
long p = s & PARTIES_MASK; // unshifted parties field |
313 |
< |
long lu = p >>> PARTIES_SHIFT; |
314 |
< |
int u = (int)lu; |
315 |
< |
int nextPhase = (phase + 1) & MAX_PHASE; |
316 |
< |
long next = ((long)nextPhase << PHASE_SHIFT) | p | lu; |
317 |
< |
if ((par = parent) == null) { |
318 |
< |
UNSAFE.compareAndSwapLong |
319 |
< |
(this, stateOffset, s, onAdvance(phase, u)? |
320 |
< |
next | TERMINATION_PHASE : next); |
321 |
< |
releaseWaiters(phase); |
322 |
< |
} |
323 |
< |
else { |
324 |
< |
par.doArrive(u == 0? |
325 |
< |
ONE_ARRIVAL|ONE_PARTY : ONE_ARRIVAL); |
326 |
< |
if ((int)(par.state >>> PHASE_SHIFT) != nextPhase || |
327 |
< |
((int)(state >>> PHASE_SHIFT) != nextPhase && |
328 |
< |
!UNSAFE.compareAndSwapLong(this, stateOffset, |
329 |
< |
s, next))) |
330 |
< |
reconcileState(); |
331 |
< |
} |
305 |
> |
for (;;) { |
306 |
> |
long s; |
307 |
> |
int phase, unarrived; |
308 |
> |
if ((phase = (int)((s = state) >>> PHASE_SHIFT)) < 0) |
309 |
> |
return phase; |
310 |
> |
else if ((unarrived = (int)(s & UNARRIVED_MASK)) == 0) |
311 |
> |
checkBadArrive(s); |
312 |
> |
else if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s -= adj)){ |
313 |
> |
if (unarrived == 1) { |
314 |
> |
Phaser par; |
315 |
> |
long p = s & PARTIES_MASK; // unshifted parties field |
316 |
> |
long lu = p >>> PARTIES_SHIFT; |
317 |
> |
int u = (int)lu; |
318 |
> |
int nextPhase = (phase + 1) & MAX_PHASE; |
319 |
> |
long next = ((long)nextPhase << PHASE_SHIFT) | p | lu; |
320 |
> |
if ((par = parent) == null) { |
321 |
> |
UNSAFE.compareAndSwapLong |
322 |
> |
(this, stateOffset, s, onAdvance(phase, u)? |
323 |
> |
next | TERMINATION_PHASE : next); |
324 |
> |
releaseWaiters(phase); |
325 |
> |
} |
326 |
> |
else { |
327 |
> |
par.doArrive(u == 0? |
328 |
> |
ONE_ARRIVAL|ONE_PARTY : ONE_ARRIVAL); |
329 |
> |
if ((int)(par.state >>> PHASE_SHIFT) != nextPhase || |
330 |
> |
((int)(state >>> PHASE_SHIFT) != nextPhase && |
331 |
> |
!UNSAFE.compareAndSwapLong(this, stateOffset, |
332 |
> |
s, next))) |
333 |
> |
reconcileState(); |
334 |
|
} |
333 |
– |
break; |
335 |
|
} |
336 |
+ |
return phase; |
337 |
|
} |
336 |
– |
else if (state == s && reconcileState() == s) // recheck |
337 |
– |
throw new IllegalStateException(badArrive()); |
338 |
|
} |
339 |
– |
return phase; |
339 |
|
} |
340 |
|
|
341 |
|
/** |
342 |
< |
* Returns message string for bounds exceptions on arrival. |
343 |
< |
* Declared out of-line from doArrive to reduce string op bulk. |
342 |
> |
* Rechecks state and throws bounds exceptions on arrival -- called |
343 |
> |
* only if unarrived is apparently zero. |
344 |
|
*/ |
345 |
< |
private String badArrive() { |
346 |
< |
return ("Attempted arrival of unregistered party for " + |
347 |
< |
this.toString()); |
345 |
> |
private void checkBadArrive(long s) { |
346 |
> |
if (reconcileState() == s) |
347 |
> |
throw new IllegalStateException |
348 |
> |
("Attempted arrival of unregistered party for " + |
349 |
> |
stateToString(s)); |
350 |
|
} |
351 |
|
|
352 |
|
/** |
358 |
|
long adj = (long)registrations; // adjustment to state |
359 |
|
adj |= adj << PARTIES_SHIFT; |
360 |
|
Phaser par = parent; |
361 |
< |
long s; |
362 |
< |
int phase; |
363 |
< |
while ((phase = (int)((s = (par == null? state : reconcileState())) |
364 |
< |
>>> PHASE_SHIFT)) >= 0) { |
365 |
< |
int parties = ((int)(s & PARTIES_MASK)) >>> PARTIES_SHIFT; |
366 |
< |
if (parties != 0 && (s & UNARRIVED_MASK) == 0) |
361 |
> |
for (;;) { |
362 |
> |
int phase, parties; |
363 |
> |
long s = par == null? state : reconcileState(); |
364 |
> |
if ((phase = (int)(s >>> PHASE_SHIFT)) < 0) |
365 |
> |
return phase; |
366 |
> |
if ((parties = ((int)(s & PARTIES_MASK)) >>> PARTIES_SHIFT) != 0 && |
367 |
> |
(s & UNARRIVED_MASK) == 0) |
368 |
|
internalAwaitAdvance(phase, null); // wait for onAdvance |
369 |
|
else if (parties + registrations > MAX_COUNT) |
370 |
< |
throw new IllegalStateException(badRegister()); |
370 |
> |
throw new IllegalStateException(badRegister(s)); |
371 |
|
else if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s + adj)) |
372 |
< |
break; |
372 |
> |
return phase; |
373 |
|
} |
372 |
– |
return phase; |
374 |
|
} |
375 |
|
|
376 |
|
/** |
377 |
|
* Returns message string for bounds exceptions on registration |
378 |
|
*/ |
379 |
< |
private String badRegister() { |
380 |
< |
return ("Attempt to register more than " + MAX_COUNT + " parties for "+ |
381 |
< |
this.toString()); |
379 |
> |
private String badRegister(long s) { |
380 |
> |
return "Attempt to register more than " + |
381 |
> |
MAX_COUNT + " parties for " + stateToString(s); |
382 |
|
} |
383 |
|
|
384 |
|
/** |
390 |
|
if (par == null) |
391 |
|
return state; |
392 |
|
Phaser rt = root; |
393 |
< |
long s; |
394 |
< |
int phase, rPhase; |
395 |
< |
while ((phase = (int)((s = state) >>> PHASE_SHIFT)) >= 0 && |
396 |
< |
(rPhase = (int)(rt.state >>> PHASE_SHIFT)) != phase) { |
397 |
< |
if (rPhase < 0 || (s & UNARRIVED_MASK) == 0) { |
398 |
< |
long ps = par.parent == null? par.state : par.reconcileState(); |
399 |
< |
int pPhase = (int)(ps >>> PHASE_SHIFT); |
400 |
< |
if (pPhase < 0 || pPhase == ((phase + 1) & MAX_PHASE)) { |
401 |
< |
if (state != s) |
402 |
< |
continue; |
403 |
< |
long p = s & PARTIES_MASK; |
404 |
< |
long next = ((((long) pPhase) << PHASE_SHIFT) | |
405 |
< |
(p >>> PARTIES_SHIFT) | p); |
406 |
< |
if (UNSAFE.compareAndSwapLong(this, stateOffset, s, next)) |
407 |
< |
return next; |
408 |
< |
} |
393 |
> |
for (;;) { |
394 |
> |
long s, u; |
395 |
> |
int phase, rPhase, pPhase; |
396 |
> |
if ((phase = (int)((s = state)>>> PHASE_SHIFT)) < 0 || |
397 |
> |
(rPhase = (int)(rt.state >>> PHASE_SHIFT)) == phase) |
398 |
> |
return s; |
399 |
> |
long pState = par.parent == null? par.state : par.reconcileState(); |
400 |
> |
if (state == s) { |
401 |
> |
if ((rPhase < 0 || (s & UNARRIVED_MASK) == 0) && |
402 |
> |
((pPhase = (int)(pState >>> PHASE_SHIFT)) < 0 || |
403 |
> |
pPhase == ((phase + 1) & MAX_PHASE))) |
404 |
> |
UNSAFE.compareAndSwapLong |
405 |
> |
(this, stateOffset, s, |
406 |
> |
(((long) pPhase) << PHASE_SHIFT) | |
407 |
> |
(u = s & PARTIES_MASK) | |
408 |
> |
(u >>> PARTIES_SHIFT)); // reset unarrived to parties |
409 |
> |
else |
410 |
> |
releaseWaiters(phase); // help release others |
411 |
|
} |
409 |
– |
if (state == s) |
410 |
– |
releaseWaiters(phase); // help release others |
412 |
|
} |
412 |
– |
return s; |
413 |
|
} |
414 |
|
|
415 |
|
/** |
506 |
|
if (parties < 0) |
507 |
|
throw new IllegalArgumentException(); |
508 |
|
if (parties > MAX_COUNT) |
509 |
< |
throw new IllegalStateException(badRegister()); |
509 |
> |
throw new IllegalStateException(badRegister(state)); |
510 |
|
if (parties == 0) |
511 |
|
return getPhase(); |
512 |
|
return doRegister(parties); |
674 |
|
* @return the phase number, or a negative value if terminated |
675 |
|
*/ |
676 |
|
public final int getPhase() { |
677 |
< |
return (int)((parent == null? state : reconcileState()) >>> PHASE_SHIFT); |
677 |
> |
return (int)((parent==null? state : reconcileState()) >>> PHASE_SHIFT); |
678 |
|
} |
679 |
|
|
680 |
|
/** |
683 |
|
* @return the number of parties |
684 |
|
*/ |
685 |
|
public int getRegisteredParties() { |
686 |
< |
return partiesOf(parent == null? state : reconcileState()); |
686 |
> |
return partiesOf(parent==null? state : reconcileState()); |
687 |
|
} |
688 |
|
|
689 |
|
/** |
693 |
|
* @return the number of arrived parties |
694 |
|
*/ |
695 |
|
public int getArrivedParties() { |
696 |
< |
return arrivedOf(parent == null? state : reconcileState()); |
696 |
> |
return arrivedOf(parent==null? state : reconcileState()); |
697 |
|
} |
698 |
|
|
699 |
|
/** |
703 |
|
* @return the number of unarrived parties |
704 |
|
*/ |
705 |
|
public int getUnarrivedParties() { |
706 |
< |
return unarrivedOf(parent == null? state : reconcileState()); |
706 |
> |
return unarrivedOf(parent==null? state : reconcileState()); |
707 |
|
} |
708 |
|
|
709 |
|
/** |
779 |
|
* @return a string identifying this barrier, as well as its state |
780 |
|
*/ |
781 |
|
public String toString() { |
782 |
< |
long s = reconcileState(); |
782 |
> |
return stateToString(reconcileState()); |
783 |
> |
} |
784 |
> |
|
785 |
> |
/** |
786 |
> |
* Implementation of toString and string-based error messages |
787 |
> |
*/ |
788 |
> |
private String stateToString(long s) { |
789 |
|
return super.toString() + |
790 |
|
"[phase = " + phaseOf(s) + |
791 |
|
" parties = " + partiesOf(s) + |
792 |
|
" arrived = " + arrivedOf(s) + "]"; |
793 |
|
} |
794 |
|
|
795 |
+ |
// Waiting mechanics |
796 |
+ |
|
797 |
|
/** |
798 |
|
* Removes and signals threads from queue for phase |
799 |
|
*/ |
850 |
|
*/ |
851 |
|
private int internalAwaitAdvance(int phase, QNode node) { |
852 |
|
Phaser current = this; // to eventually wait at root if tiered |
853 |
< |
Phaser par = parent; |
846 |
< |
boolean queued = false; |
847 |
< |
int spins = SPINS_PER_ARRIVAL; |
853 |
> |
boolean queued = false; // true when node is enqueued |
854 |
|
int lastUnarrived = -1; // to increase spins upon change |
855 |
< |
long s; |
856 |
< |
int p; |
857 |
< |
while ((p = (int)((s = current.state) >>> PHASE_SHIFT)) == phase) { |
858 |
< |
int unarrived = (int)(s & UNARRIVED_MASK); |
859 |
< |
if (unarrived != lastUnarrived) { |
855 |
> |
int spins = SPINS_PER_ARRIVAL; |
856 |
> |
for (;;) { |
857 |
> |
int p, unarrived; |
858 |
> |
Phaser par; |
859 |
> |
long s = current.state; |
860 |
> |
if ((p = (int)(s >>> PHASE_SHIFT)) != phase) { |
861 |
> |
if (node != null) |
862 |
> |
node.onRelease(); |
863 |
> |
releaseWaiters(phase); |
864 |
> |
return p; |
865 |
> |
} |
866 |
> |
else if ((unarrived = (int)(s & UNARRIVED_MASK)) != lastUnarrived) { |
867 |
|
if ((lastUnarrived = unarrived) < NCPU) |
868 |
|
spins += SPINS_PER_ARRIVAL; |
869 |
|
} |
870 |
< |
else if (unarrived == 0 && par != null) { |
870 |
> |
else if (unarrived == 0 && (par = current.parent) != null) { |
871 |
|
current = par; // if all arrived, use parent |
872 |
|
par = par.parent; |
873 |
+ |
lastUnarrived = -1; |
874 |
|
} |
875 |
|
else if (spins > 0) |
876 |
|
--spins; |
877 |
< |
else if (node == null) |
877 |
> |
else if (node == null) // must be noninterruptible |
878 |
|
node = new QNode(this, phase, false, false, 0L); |
879 |
< |
else if (node.isReleasable()) |
880 |
< |
break; |
879 |
> |
else if (node.isReleasable()) { |
880 |
> |
if ((int)(reconcileState() >>> PHASE_SHIFT) == phase) |
881 |
> |
return phase; // aborted |
882 |
> |
} |
883 |
|
else if (!queued) |
884 |
|
queued = tryEnqueue(phase, node); |
885 |
|
else { |
890 |
|
} |
891 |
|
} |
892 |
|
} |
877 |
– |
if (node != null) { |
878 |
– |
if (node.thread != null) |
879 |
– |
node.thread = null; |
880 |
– |
if (!node.interruptible && node.wasInterrupted) |
881 |
– |
Thread.currentThread().interrupt(); |
882 |
– |
} |
883 |
– |
if (p == phase) |
884 |
– |
p = (int)(reconcileState() >>> PHASE_SHIFT); |
885 |
– |
if (p != phase) |
886 |
– |
releaseWaiters(phase); |
887 |
– |
return p; |
893 |
|
} |
894 |
|
|
895 |
|
/** |
961 |
|
LockSupport.unpark(t); |
962 |
|
} |
963 |
|
} |
964 |
+ |
|
965 |
+ |
void onRelease() { // actions upon return from internalAwaitAdvance |
966 |
+ |
if (!interruptible && wasInterrupted) |
967 |
+ |
Thread.currentThread().interrupt(); |
968 |
+ |
if (thread != null) |
969 |
+ |
thread = null; |
970 |
+ |
} |
971 |
+ |
|
972 |
|
} |
973 |
|
|
974 |
|
// Unsafe mechanics |