| 51 |
|
* dynamically adding, suspending, or resuming internal worker |
| 52 |
|
* threads, even if some tasks are stalled waiting to join |
| 53 |
|
* others. However, no such adjustments are guaranteed in the face of |
| 54 |
< |
* blocked IO or other unmanaged synchronization. The nested {@link |
| 54 |
> |
* blocked I/O or other unmanaged synchronization. The nested {@link |
| 55 |
|
* ManagedBlocker} interface enables extension of the kinds of |
| 56 |
|
* synchronization accommodated. |
| 57 |
|
* |
| 1129 |
|
private static final long FAST_IDLE_TIMEOUT = 200L * 1000L * 1000L; |
| 1130 |
|
|
| 1131 |
|
/** |
| 1132 |
+ |
* Tolerance for idle timeouts, to cope with timer undershoots |
| 1133 |
+ |
*/ |
| 1134 |
+ |
private static final long TIMEOUT_SLOP = 2000000L; // 20ms |
| 1135 |
+ |
|
| 1136 |
+ |
/** |
| 1137 |
|
* The maximum stolen->joining link depth allowed in method |
| 1138 |
|
* tryHelpStealer. Must be a power of two. Depths for legitimate |
| 1139 |
|
* chains are unbounded, but we use a fixed constant to avoid |
| 1331 |
|
* wrap around zero, this method harmlessly fails to reinitialize |
| 1332 |
|
* if workQueues exists, while still advancing plock. |
| 1333 |
|
* |
| 1334 |
< |
* Additonally tries to create the first worker. |
| 1334 |
> |
* Additionally tries to create the first worker. |
| 1335 |
|
*/ |
| 1336 |
|
private void initWorkers() { |
| 1337 |
|
WorkQueue[] ws, nws; int ps; |
| 1355 |
|
} |
| 1356 |
|
|
| 1357 |
|
/** |
| 1358 |
< |
* Tries to create and start one worker. Adjusts counts etc on |
| 1359 |
< |
* failure. |
| 1358 |
> |
* Tries to create and start one worker if fewer than target |
| 1359 |
> |
* parallelism level exist. Adjusts counts etc on failure. |
| 1360 |
|
*/ |
| 1361 |
|
private void tryAddWorker() { |
| 1362 |
|
long c; int u; |
| 1472 |
|
((c - TC_UNIT) & TC_MASK) | |
| 1473 |
|
(c & ~(AC_MASK|TC_MASK))))); |
| 1474 |
|
|
| 1475 |
< |
if (!tryTerminate(false, false) && w != null) { |
| 1475 |
> |
if (!tryTerminate(false, false) && w != null && w.array != null) { |
| 1476 |
|
w.cancelAll(); // cancel remaining tasks |
| 1477 |
< |
if (w.array != null) // suppress signal if never ran |
| 1478 |
< |
tryAddWorker(); // create replacement |
| 1479 |
< |
if (ex == null) // help clean refs on way out |
| 1480 |
< |
ForkJoinTask.helpExpungeStaleExceptions(); |
| 1477 |
> |
int e, u, i, n; WorkQueue[] ws; WorkQueue v; Thread p; |
| 1478 |
> |
while ((u = (int)((c = ctl) >>> 32)) < 0) { |
| 1479 |
> |
if ((e = (int)c) > 0) { // activate or create replacement |
| 1480 |
> |
if ((ws = workQueues) != null && |
| 1481 |
> |
ws.length > (i = e & SMASK) && |
| 1482 |
> |
(v = ws[i]) != null && v.eventCount == (e | INT_SIGN)) { |
| 1483 |
> |
long nc = (((long)(v.nextWait & E_MASK)) | |
| 1484 |
> |
((long)(u + UAC_UNIT) << 32)); |
| 1485 |
> |
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
| 1486 |
> |
v.eventCount = (e + E_SEQ) & E_MASK; |
| 1487 |
> |
if ((p = v.parker) != null) |
| 1488 |
> |
U.unpark(p); |
| 1489 |
> |
break; |
| 1490 |
> |
} |
| 1491 |
> |
} |
| 1492 |
> |
else |
| 1493 |
> |
break; |
| 1494 |
> |
} |
| 1495 |
> |
else { |
| 1496 |
> |
if ((short)u < 0) |
| 1497 |
> |
tryAddWorker(); |
| 1498 |
> |
break; |
| 1499 |
> |
} |
| 1500 |
> |
} |
| 1501 |
|
} |
| 1502 |
< |
|
| 1503 |
< |
if (ex != null) // rethrow |
| 1502 |
> |
if (ex == null) // help clean refs on way out |
| 1503 |
> |
ForkJoinTask.helpExpungeStaleExceptions(); |
| 1504 |
> |
else // rethrow |
| 1505 |
|
ForkJoinTask.rethrow(ex); |
| 1506 |
|
} |
| 1507 |
|
|
| 1754 |
|
U.putObject(wt, PARKBLOCKER, null); |
| 1755 |
|
} |
| 1756 |
|
} |
| 1757 |
< |
if (h >= 0 || (h = w.hint) >= 0) { // signal others before retry |
| 1758 |
< |
w.hint = -1; // reset |
| 1733 |
< |
helpSignal(null, h, true); |
| 1734 |
< |
} |
| 1757 |
> |
if (h >= 0 || w.hint >= 0) // signal others before retry |
| 1758 |
> |
helpSignalHint(w); |
| 1759 |
|
} |
| 1760 |
|
return null; |
| 1761 |
|
} |
| 1777 |
|
!tryTerminate(false, false) && (int)prevCtl != 0) { |
| 1778 |
|
int dc = -(short)(currentCtl >>> TC_SHIFT); |
| 1779 |
|
long parkTime = dc < 0 ? FAST_IDLE_TIMEOUT: (dc + 1) * IDLE_TIMEOUT; |
| 1780 |
< |
long deadline = System.nanoTime() + parkTime - 100000L; // 1ms slop |
| 1780 |
> |
long deadline = System.nanoTime() + parkTime - TIMEOUT_SLOP; |
| 1781 |
|
Thread wt = Thread.currentThread(); |
| 1782 |
|
while (ctl == currentCtl) { |
| 1783 |
|
Thread.interrupted(); // timed variant of version in scan() |
| 1800 |
|
} |
| 1801 |
|
|
| 1802 |
|
/** |
| 1803 |
< |
* Scans through queues looking for work (optionally, while |
| 1804 |
< |
* joining a task); if any present, signals. May return early if |
| 1805 |
< |
* more signalling is detectably unneeded. |
| 1803 |
> |
* Scans through queues looking for work while joining a task; if |
| 1804 |
> |
* any present, signals. May return early if more signalling is |
| 1805 |
> |
* detectably unneeded. |
| 1806 |
|
* |
| 1807 |
< |
* @param task if non-null, return early if done |
| 1807 |
> |
* @param task return early if done |
| 1808 |
|
* @param origin an index to start scan |
| 1785 |
– |
* @param once if only the origin should be checked |
| 1809 |
|
*/ |
| 1810 |
< |
private void helpSignal(ForkJoinTask<?> task, int origin, boolean once) { |
| 1810 |
> |
private void helpSignal(ForkJoinTask<?> task, int origin) { |
| 1811 |
|
WorkQueue[] ws; WorkQueue w; Thread p; long c; int m, u, e, i, s; |
| 1812 |
< |
if ((u = (int)(ctl >>> 32)) < 0 && (u >> UAC_SHIFT) < 0 && |
| 1812 |
> |
if (task != null && task.status >= 0 && |
| 1813 |
> |
(u = (int)(ctl >>> 32)) < 0 && (u >> UAC_SHIFT) < 0 && |
| 1814 |
|
(ws = workQueues) != null && (m = ws.length - 1) >= 0) { |
| 1815 |
< |
outer: for (int k = origin, j = once ? 0 : m; j >= 0; --j) { |
| 1815 |
> |
outer: for (int k = origin, j = m; j >= 0; --j) { |
| 1816 |
|
WorkQueue q = ws[k++ & m]; |
| 1817 |
|
for (int n = m;;) { // limit to at most m signals |
| 1818 |
< |
if (task != null && task.status < 0) |
| 1818 |
> |
if (task.status < 0) |
| 1819 |
|
break outer; |
| 1820 |
|
if (q == null || |
| 1821 |
< |
((s = (task == null ? -1 : 0) - q.base + q.top) <= n && |
| 1798 |
< |
(n = s) <= 0)) |
| 1821 |
> |
((s = -q.base + q.top) <= n && (n = s) <= 0)) |
| 1822 |
|
break; |
| 1823 |
|
if ((u = (int)((c = ctl) >>> 32)) >= 0 || |
| 1824 |
|
(e = (int)c) <= 0 || m < (i = e & SMASK) || |
| 1840 |
|
} |
| 1841 |
|
|
| 1842 |
|
/** |
| 1843 |
+ |
* Signals other workers if tasks are present in hinted queue. |
| 1844 |
+ |
* |
| 1845 |
+ |
* @param caller the worker with the hint |
| 1846 |
+ |
*/ |
| 1847 |
+ |
private void helpSignalHint(WorkQueue caller) { |
| 1848 |
+ |
WorkQueue[] ws; WorkQueue q, w; Thread p; long c; int h, m, u, e, i, s; |
| 1849 |
+ |
if (caller != null && (h = caller.hint) >= 0) { |
| 1850 |
+ |
caller.hint = -1; |
| 1851 |
+ |
if ((u = (int)(ctl >>> 32)) < 0 && (u >> UAC_SHIFT) < 0 && |
| 1852 |
+ |
(ws = workQueues) != null && (m = ws.length - 1) >= 0 && |
| 1853 |
+ |
(q = ws[h & m]) != null) { |
| 1854 |
+ |
for (int n = 2;;) { // limit to at most 2 signals |
| 1855 |
+ |
int idleCount = (caller.eventCount < 0) ? 0 : -1; |
| 1856 |
+ |
if (((s = idleCount - q.base + q.top) <= n && |
| 1857 |
+ |
(n = s) <= 0) || |
| 1858 |
+ |
(u = (int)((c = ctl) >>> 32)) >= 0 || |
| 1859 |
+ |
(e = (int)c) <= 0 || m < (i = e & SMASK) || |
| 1860 |
+ |
(w = ws[i]) == null) |
| 1861 |
+ |
break; |
| 1862 |
+ |
long nc = (((long)(w.nextWait & E_MASK)) | |
| 1863 |
+ |
((long)(u + UAC_UNIT) << 32)); |
| 1864 |
+ |
if (w.eventCount == (e | INT_SIGN) && |
| 1865 |
+ |
U.compareAndSwapLong(this, CTL, c, nc)) { |
| 1866 |
+ |
w.hint = h; |
| 1867 |
+ |
w.eventCount = (e + E_SEQ) & E_MASK; |
| 1868 |
+ |
if ((p = w.parker) != null) |
| 1869 |
+ |
U.unpark(p); |
| 1870 |
+ |
if (--n <= 0) |
| 1871 |
+ |
break; |
| 1872 |
+ |
} |
| 1873 |
+ |
} |
| 1874 |
+ |
} |
| 1875 |
+ |
} |
| 1876 |
+ |
} |
| 1877 |
+ |
|
| 1878 |
+ |
/** |
| 1879 |
|
* Tries to locate and execute tasks for a stealer of the given |
| 1880 |
|
* task, or in turn one of its stealers, Traces currentSteal -> |
| 1881 |
|
* currentJoin links looking for a thread working on a descendant |
| 2055 |
|
do {} while ((s = task.status) >= 0 && !joiner.isEmpty() && |
| 2056 |
|
joiner.tryRemoveAndExec(task)); // process local tasks |
| 2057 |
|
if (s >= 0 && (s = task.status) >= 0) { |
| 2058 |
< |
helpSignal(task, joiner.poolIndex, false); |
| 2058 |
> |
helpSignal(task, joiner.poolIndex); |
| 2059 |
|
if ((s = task.status) >= 0 && |
| 2060 |
|
(task instanceof CountedCompleter)) |
| 2061 |
|
s = helpComplete(task, LIFO_QUEUE); |
| 2064 |
|
if ((!joiner.isEmpty() || // try helping |
| 2065 |
|
(s = tryHelpStealer(joiner, task)) == 0) && |
| 2066 |
|
(s = task.status) >= 0) { |
| 2067 |
< |
helpSignal(task, joiner.poolIndex, false); |
| 2067 |
> |
helpSignal(task, joiner.poolIndex); |
| 2068 |
|
if ((s = task.status) >= 0 && tryCompensate()) { |
| 2069 |
|
if (task.trySetSignal() && (s = task.status) >= 0) { |
| 2070 |
|
synchronized (task) { |
| 2105 |
|
do {} while ((s = task.status) >= 0 && !joiner.isEmpty() && |
| 2106 |
|
joiner.tryRemoveAndExec(task)); |
| 2107 |
|
if (s >= 0 && (s = task.status) >= 0) { |
| 2108 |
< |
helpSignal(task, joiner.poolIndex, false); |
| 2108 |
> |
helpSignal(task, joiner.poolIndex); |
| 2109 |
|
if ((s = task.status) >= 0 && |
| 2110 |
|
(task instanceof CountedCompleter)) |
| 2111 |
|
s = helpComplete(task, LIFO_QUEUE); |
| 2437 |
|
(u = (int)(ctl >>> 32)) >= 0 || (u >> UAC_SHIFT) >= 0) |
| 2438 |
|
break; |
| 2439 |
|
if (task == null) { |
| 2440 |
< |
helpSignal(root, q.poolIndex, false); |
| 2440 |
> |
helpSignal(root, q.poolIndex); |
| 2441 |
|
if (root.status >= 0) |
| 2442 |
|
helpComplete(root, SHARED_QUEUE); |
| 2443 |
|
break; |
| 2480 |
|
if (t instanceof CountedCompleter) |
| 2481 |
|
p.externalHelpComplete(q, t); |
| 2482 |
|
else |
| 2483 |
< |
p.helpSignal(t, q.poolIndex, false); |
| 2483 |
> |
p.helpSignal(t, q.poolIndex); |
| 2484 |
|
} |
| 2485 |
|
} |
| 2486 |
|
} |
| 3095 |
|
* commenced but not yet completed. This method may be useful for |
| 3096 |
|
* debugging. A return of {@code true} reported a sufficient |
| 3097 |
|
* period after shutdown may indicate that submitted tasks have |
| 3098 |
< |
* ignored or suppressed interruption, or are waiting for IO, |
| 3098 |
> |
* ignored or suppressed interruption, or are waiting for I/O, |
| 3099 |
|
* causing this executor not to properly terminate. (See the |
| 3100 |
|
* advisory notes for class {@link ForkJoinTask} stating that |
| 3101 |
|
* tasks should not normally entail blocking operations. But if |
