| 260 |
|
* parent. |
| 261 |
|
* |
| 262 |
|
* The phase of a subphaser is allowed to lag that of its |
| 263 |
< |
* ancestors until it is actually accessed. Method reconcileState |
| 264 |
< |
* is usually attempted only only when the number of unarrived |
| 265 |
< |
* parties appears to be zero, which indicates a potential lag in |
| 266 |
< |
* updating phase after the root advanced. |
| 263 |
> |
* ancestors until it is actually accessed -- see method |
| 264 |
> |
* reconcileState. |
| 265 |
|
*/ |
| 266 |
|
private volatile long state; |
| 267 |
|
|
| 269 |
|
private static final int MAX_PHASE = 0x7fffffff; |
| 270 |
|
private static final int PARTIES_SHIFT = 16; |
| 271 |
|
private static final int PHASE_SHIFT = 32; |
| 272 |
+ |
private static final long PHASE_MASK = -1L << PHASE_SHIFT; |
| 273 |
|
private static final int UNARRIVED_MASK = 0xffff; // to mask ints |
| 274 |
|
private static final long PARTIES_MASK = 0xffff0000L; // to mask longs |
| 275 |
|
private static final long TERMINATION_BIT = 1L << 63; |
| 435 |
|
|
| 436 |
|
/** |
| 437 |
|
* Resolves lagged phase propagation from root if necessary. |
| 438 |
+ |
* Reconciliation normally occurs when root has advanced but |
| 439 |
+ |
* subphasers have not yet done so, in which case they must finish |
| 440 |
+ |
* their own advance by setting unarrived to parties (or if |
| 441 |
+ |
* parties is zero, resetting to unregistered EMPTY state). |
| 442 |
+ |
* However, this method may also be called when "floating" |
| 443 |
+ |
* subphasers with possibly some unarrived parties are merely |
| 444 |
+ |
* catching up to current phase, in which case counts are |
| 445 |
+ |
* unaffected. |
| 446 |
+ |
* |
| 447 |
+ |
* @return reconciled state |
| 448 |
|
*/ |
| 449 |
|
private long reconcileState() { |
| 450 |
< |
Phaser rt = root; |
| 450 |
> |
final Phaser root = this.root; |
| 451 |
|
long s = state; |
| 452 |
< |
if (rt != this) { |
| 453 |
< |
int phase; |
| 454 |
< |
while ((phase = (int)(rt.state >>> PHASE_SHIFT)) != |
| 455 |
< |
(int)(s >>> PHASE_SHIFT)) { |
| 456 |
< |
// assert phase < 0 || unarrivedOf(s) == 0 |
| 457 |
< |
long t; // to reread s |
| 458 |
< |
long p = s & PARTIES_MASK; // unshifted parties field |
| 459 |
< |
long n = (((long) phase) << PHASE_SHIFT) | p; |
| 460 |
< |
if (phase >= 0) { |
| 461 |
< |
if (p == 0L) |
| 462 |
< |
n |= EMPTY; // reset to empty |
| 454 |
< |
else |
| 455 |
< |
n |= p >>> PARTIES_SHIFT; // set unarr to parties |
| 456 |
< |
} |
| 457 |
< |
if ((t = state) == s && |
| 458 |
< |
UNSAFE.compareAndSwapLong(this, stateOffset, s, s = n)) |
| 459 |
< |
break; |
| 460 |
< |
s = t; |
| 461 |
< |
} |
| 452 |
> |
if (root != this) { |
| 453 |
> |
int phase, u, p; |
| 454 |
> |
// CAS root phase with current parties; possibly trip unarrived |
| 455 |
> |
while ((phase = (int)(root.state >>> PHASE_SHIFT)) != |
| 456 |
> |
(int)(s >>> PHASE_SHIFT) && |
| 457 |
> |
!UNSAFE.compareAndSwapLong |
| 458 |
> |
(this, stateOffset, s, |
| 459 |
> |
s = ((((long) phase) << PHASE_SHIFT) | (s & PARTIES_MASK) | |
| 460 |
> |
((p = (int)s >>> PARTIES_SHIFT) == 0 ? EMPTY : |
| 461 |
> |
(u = (int)s & UNARRIVED_MASK) == 0 ? p : u)))) |
| 462 |
> |
s = state; |
| 463 |
|
} |
| 464 |
|
return s; |
| 465 |
|
} |
| 777 |
|
final Phaser root = this.root; |
| 778 |
|
long s; |
| 779 |
|
while ((s = root.state) >= 0) { |
| 780 |
< |
long next = (s & ~((long)UNARRIVED_MASK)) | TERMINATION_BIT; |
| 781 |
< |
if (UNSAFE.compareAndSwapLong(root, stateOffset, s, next)) { |
| 780 |
> |
if (UNSAFE.compareAndSwapLong(root, stateOffset, |
| 781 |
> |
s, s | TERMINATION_BIT)) { |
| 782 |
|
// signal all threads |
| 783 |
|
releaseWaiters(0); |
| 784 |
|
releaseWaiters(1); |
| 811 |
|
|
| 812 |
|
/** |
| 813 |
|
* Returns the number of registered parties that have arrived at |
| 814 |
< |
* the current phase of this phaser. |
| 814 |
> |
* the current phase of this phaser. If this phaser has terminated, |
| 815 |
> |
* the returned value is meaningless and arbitrary. |
| 816 |
|
* |
| 817 |
|
* @return the number of arrived parties |
| 818 |
|
*/ |
| 822 |
|
|
| 823 |
|
/** |
| 824 |
|
* Returns the number of registered parties that have not yet |
| 825 |
< |
* arrived at the current phase of this phaser. |
| 825 |
> |
* arrived at the current phase of this phaser. If this phaser has |
| 826 |
> |
* terminated, the returned value is meaningless and arbitrary. |
| 827 |
|
* |
| 828 |
|
* @return the number of unarrived parties |
| 829 |
|
*/ |
