139 |
|
*/ |
140 |
|
public abstract class ForkJoinTask<V> implements Future<V>, Serializable { |
141 |
|
|
142 |
+ |
/* |
143 |
+ |
* See the internal documentation of class ForkJoinPool for a |
144 |
+ |
* general implementation overview. ForkJoinTasks are mainly |
145 |
+ |
* responsible for maintaining their "status" field amidst relays |
146 |
+ |
* to methods in ForkJoinWorkerThread and ForkJoinPool. The |
147 |
+ |
* methods of this class are more-or-less layered into (1) basic |
148 |
+ |
* status maintenance (2) execution and awaiting completion (3) |
149 |
+ |
* user-level methods that additionally report results. This is |
150 |
+ |
* sometimes hard to see because this file orders exported methods |
151 |
+ |
* in a way that flows well in javadocs. |
152 |
+ |
*/ |
153 |
+ |
|
154 |
|
/** |
155 |
|
* Run control status bits packed into a single int to minimize |
156 |
|
* footprint and to ensure atomicity (via CAS). Status is |
157 |
|
* initially zero, and takes on nonnegative values until |
158 |
|
* completed, upon which status holds COMPLETED. CANCELLED, or |
159 |
|
* EXCEPTIONAL, which use the top 3 bits. Tasks undergoing |
160 |
< |
* blocking waits by other threads have SIGNAL_MASK bits set -- |
161 |
< |
* bit 15 for external (nonFJ) waits, and the rest a count of |
162 |
< |
* waiting FJ threads. (This representation relies on |
163 |
< |
* ForkJoinPool max thread limits). Completion of a stolen task |
164 |
< |
* with SIGNAL_MASK bits set awakens waiter via notifyAll. Even |
165 |
< |
* though suboptimal for some purposes, we use basic builtin |
166 |
< |
* wait/notify to take advantage of "monitor inflation" in JVMs |
167 |
< |
* that we would otherwise need to emulate to avoid adding further |
168 |
< |
* per-task bookkeeping overhead. Note that bits 16-28 are |
169 |
< |
* currently unused. Also value 0x80000000 is available as spare |
170 |
< |
* completion value. |
160 |
> |
* blocking waits by other threads have the SIGNAL bit set. |
161 |
> |
* |
162 |
> |
* Completion of a stolen task with SIGNAL set awakens any waiters |
163 |
> |
* via notifyAll. Even though suboptimal for some purposes, we use |
164 |
> |
* basic builtin wait/notify to take advantage of "monitor |
165 |
> |
* inflation" in JVMs that we would otherwise need to emulate to |
166 |
> |
* avoid adding further per-task bookkeeping overhead. We want |
167 |
> |
* these monitors to be "fat", i.e., not use biasing or thin-lock |
168 |
> |
* techniques, so use some odd coding idioms that tend to avoid |
169 |
> |
* them. |
170 |
> |
* |
171 |
> |
* Note that bits 1-28 are currently unused. Also value |
172 |
> |
* 0x80000000 is available as spare completion value. |
173 |
|
*/ |
174 |
|
volatile int status; // accessed directly by pool and workers |
175 |
|
|
176 |
< |
static final int COMPLETION_MASK = 0xe0000000; |
177 |
< |
static final int NORMAL = 0xe0000000; // == mask |
178 |
< |
static final int CANCELLED = 0xc0000000; |
179 |
< |
static final int EXCEPTIONAL = 0xa0000000; |
180 |
< |
static final int SIGNAL_MASK = 0x0000ffff; |
167 |
< |
static final int INTERNAL_SIGNAL_MASK = 0x00007fff; |
168 |
< |
static final int EXTERNAL_SIGNAL = 0x00008000; // top bit of low word |
176 |
> |
private static final int COMPLETION_MASK = 0xe0000000; |
177 |
> |
private static final int NORMAL = 0xe0000000; // == mask |
178 |
> |
private static final int CANCELLED = 0xc0000000; |
179 |
> |
private static final int EXCEPTIONAL = 0xa0000000; |
180 |
> |
private static final int SIGNAL = 0x00000001; |
181 |
|
|
182 |
|
/** |
183 |
|
* Table of exceptions thrown by tasks, to enable reporting by |
191 |
|
Collections.synchronizedMap |
192 |
|
(new WeakHashMap<ForkJoinTask<?>, Throwable>()); |
193 |
|
|
194 |
< |
// within-package utilities |
183 |
< |
|
184 |
< |
/** |
185 |
< |
* Gets current worker thread, or null if not a worker thread. |
186 |
< |
*/ |
187 |
< |
static ForkJoinWorkerThread getWorker() { |
188 |
< |
Thread t = Thread.currentThread(); |
189 |
< |
return ((t instanceof ForkJoinWorkerThread) ? |
190 |
< |
(ForkJoinWorkerThread) t : null); |
191 |
< |
} |
192 |
< |
|
193 |
< |
final boolean casStatus(int cmp, int val) { |
194 |
< |
return UNSAFE.compareAndSwapInt(this, statusOffset, cmp, val); |
195 |
< |
} |
196 |
< |
|
197 |
< |
/** |
198 |
< |
* Workaround for not being able to rethrow unchecked exceptions. |
199 |
< |
*/ |
200 |
< |
static void rethrowException(Throwable ex) { |
201 |
< |
if (ex != null) |
202 |
< |
UNSAFE.throwException(ex); |
203 |
< |
} |
204 |
< |
|
205 |
< |
// Setting completion status |
194 |
> |
// Maintaining completion status |
195 |
|
|
196 |
|
/** |
197 |
< |
* Marks completion and wakes up threads waiting to join this task. |
197 |
> |
* Marks completion and wakes up threads waiting to join this task, |
198 |
> |
* also clearing signal request bits. |
199 |
|
* |
200 |
|
* @param completion one of NORMAL, CANCELLED, EXCEPTIONAL |
201 |
+ |
* @return status on exit |
202 |
|
*/ |
203 |
< |
final void setCompletion(int completion) { |
213 |
< |
ForkJoinPool pool = getPool(); |
214 |
< |
if (pool != null) { |
215 |
< |
int s; // Clear signal bits while setting completion status |
216 |
< |
do {} while ((s = status) >= 0 && !casStatus(s, completion)); |
217 |
< |
|
218 |
< |
if ((s & SIGNAL_MASK) != 0) { |
219 |
< |
if ((s &= INTERNAL_SIGNAL_MASK) != 0) |
220 |
< |
pool.updateRunningCount(s); |
221 |
< |
synchronized (this) { notifyAll(); } |
222 |
< |
} |
223 |
< |
} |
224 |
< |
else |
225 |
< |
externallySetCompletion(completion); |
226 |
< |
} |
227 |
< |
|
228 |
< |
/** |
229 |
< |
* Version of setCompletion for non-FJ threads. Leaves signal |
230 |
< |
* bits for unblocked threads to adjust, and always notifies. |
231 |
< |
*/ |
232 |
< |
private void externallySetCompletion(int completion) { |
203 |
> |
private int setCompletion(int completion) { |
204 |
|
int s; |
205 |
< |
do {} while ((s = status) >= 0 && |
206 |
< |
!casStatus(s, (s & SIGNAL_MASK) | completion)); |
207 |
< |
synchronized (this) { notifyAll(); } |
208 |
< |
} |
209 |
< |
|
239 |
< |
/** |
240 |
< |
* Sets status to indicate normal completion. |
241 |
< |
*/ |
242 |
< |
final void setNormalCompletion() { |
243 |
< |
// Try typical fast case -- single CAS, no signal, not already done. |
244 |
< |
// Manually expand casStatus to improve chances of inlining it |
245 |
< |
if (!UNSAFE.compareAndSwapInt(this, statusOffset, 0, NORMAL)) |
246 |
< |
setCompletion(NORMAL); |
247 |
< |
} |
248 |
< |
|
249 |
< |
// internal waiting and notification |
250 |
< |
|
251 |
< |
/** |
252 |
< |
* Performs the actual monitor wait for awaitDone. |
253 |
< |
*/ |
254 |
< |
private void doAwaitDone() { |
255 |
< |
// Minimize lock bias and in/de-flation effects by maximizing |
256 |
< |
// chances of waiting inside sync |
257 |
< |
try { |
258 |
< |
while (status >= 0) |
259 |
< |
synchronized (this) { if (status >= 0) wait(); } |
260 |
< |
} catch (InterruptedException ie) { |
261 |
< |
onInterruptedWait(); |
262 |
< |
} |
263 |
< |
} |
264 |
< |
|
265 |
< |
/** |
266 |
< |
* Performs the actual timed monitor wait for awaitDone. |
267 |
< |
*/ |
268 |
< |
private void doAwaitDone(long startTime, long nanos) { |
269 |
< |
synchronized (this) { |
270 |
< |
try { |
271 |
< |
while (status >= 0) { |
272 |
< |
long nt = nanos - (System.nanoTime() - startTime); |
273 |
< |
if (nt <= 0) |
274 |
< |
break; |
275 |
< |
wait(nt / 1000000, (int) (nt % 1000000)); |
276 |
< |
} |
277 |
< |
} catch (InterruptedException ie) { |
278 |
< |
onInterruptedWait(); |
205 |
> |
while ((s = status) >= 0) { |
206 |
> |
if (UNSAFE.compareAndSwapInt(this, statusOffset, s, completion)) { |
207 |
> |
if ((s & SIGNAL) != 0) |
208 |
> |
synchronized (this) { notifyAll(); } |
209 |
> |
return completion; |
210 |
|
} |
211 |
|
} |
212 |
+ |
return s; |
213 |
|
} |
214 |
|
|
283 |
– |
// Awaiting completion |
284 |
– |
|
215 |
|
/** |
216 |
< |
* Sets status to indicate there is joiner, then waits for join, |
217 |
< |
* surrounded with pool notifications. |
288 |
< |
* |
289 |
< |
* @return status upon exit |
216 |
> |
* Record exception and set exceptional completion |
217 |
> |
* @return status on exit |
218 |
|
*/ |
219 |
< |
private int awaitDone(ForkJoinWorkerThread w, |
220 |
< |
boolean maintainParallelism) { |
221 |
< |
ForkJoinPool pool = (w == null) ? null : w.pool; |
294 |
< |
int s; |
295 |
< |
while ((s = status) >= 0) { |
296 |
< |
if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) { |
297 |
< |
if (pool == null || !pool.preJoin(this, maintainParallelism)) |
298 |
< |
doAwaitDone(); |
299 |
< |
if (((s = status) & INTERNAL_SIGNAL_MASK) != 0) |
300 |
< |
adjustPoolCountsOnUnblock(pool); |
301 |
< |
break; |
302 |
< |
} |
303 |
< |
} |
304 |
< |
return s; |
219 |
> |
private int setExceptionalCompletion(Throwable rex) { |
220 |
> |
exceptionMap.put(this, rex); |
221 |
> |
return setCompletion(EXCEPTIONAL); |
222 |
|
} |
223 |
|
|
224 |
|
/** |
225 |
< |
* Timed version of awaitDone |
309 |
< |
* |
310 |
< |
* @return status upon exit |
225 |
> |
* Blocks a worker thread until completion. Called only by pool. |
226 |
|
*/ |
227 |
< |
private int awaitDone(ForkJoinWorkerThread w, long nanos) { |
313 |
< |
ForkJoinPool pool = (w == null) ? null : w.pool; |
227 |
> |
final void internalAwaitDone() { |
228 |
|
int s; |
229 |
|
while ((s = status) >= 0) { |
230 |
< |
if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) { |
231 |
< |
long startTime = System.nanoTime(); |
232 |
< |
if (pool == null || !pool.preJoin(this, false)) |
233 |
< |
doAwaitDone(startTime, nanos); |
234 |
< |
if ((s = status) >= 0) { |
235 |
< |
adjustPoolCountsOnCancelledWait(pool); |
236 |
< |
s = status; |
230 |
> |
synchronized(this) { |
231 |
> |
if (UNSAFE.compareAndSwapInt(this, statusOffset, s, s|SIGNAL)){ |
232 |
> |
do { |
233 |
> |
try { |
234 |
> |
wait(); |
235 |
> |
} catch (InterruptedException ie) { |
236 |
> |
cancelIfTerminating(); |
237 |
> |
} |
238 |
> |
} while (status >= 0); |
239 |
> |
break; |
240 |
|
} |
324 |
– |
if (s < 0 && (s & INTERNAL_SIGNAL_MASK) != 0) |
325 |
– |
adjustPoolCountsOnUnblock(pool); |
326 |
– |
break; |
241 |
|
} |
242 |
|
} |
329 |
– |
return s; |
243 |
|
} |
244 |
|
|
245 |
|
/** |
246 |
< |
* Notifies pool that thread is unblocked. Called by signalled |
247 |
< |
* threads when woken by non-FJ threads (which is atypical). |
246 |
> |
* Blocks a non-worker-thread until completion. |
247 |
> |
* @return status on exit |
248 |
|
*/ |
249 |
< |
private void adjustPoolCountsOnUnblock(ForkJoinPool pool) { |
249 |
> |
private int externalAwaitDone() { |
250 |
|
int s; |
251 |
< |
do {} while ((s = status) < 0 && !casStatus(s, s & COMPLETION_MASK)); |
252 |
< |
if (pool != null && (s &= INTERNAL_SIGNAL_MASK) != 0) |
253 |
< |
pool.updateRunningCount(s); |
254 |
< |
} |
255 |
< |
|
256 |
< |
/** |
257 |
< |
* Notifies pool to adjust counts on cancelled or timed out wait. |
258 |
< |
*/ |
259 |
< |
private void adjustPoolCountsOnCancelledWait(ForkJoinPool pool) { |
260 |
< |
if (pool != null) { |
261 |
< |
int s; |
262 |
< |
while ((s = status) >= 0 && (s & INTERNAL_SIGNAL_MASK) != 0) { |
263 |
< |
if (casStatus(s, s - 1)) { |
351 |
< |
pool.updateRunningCount(1); |
251 |
> |
while ((s = status) >= 0) { |
252 |
> |
synchronized(this) { |
253 |
> |
if (UNSAFE.compareAndSwapInt(this, statusOffset, s, s|SIGNAL)){ |
254 |
> |
boolean interrupted = false; |
255 |
> |
do { |
256 |
> |
try { |
257 |
> |
wait(); |
258 |
> |
} catch (InterruptedException ie) { |
259 |
> |
interrupted = true; |
260 |
> |
} |
261 |
> |
} while ((s = status) >= 0); |
262 |
> |
if (interrupted) |
263 |
> |
Thread.currentThread().interrupt(); |
264 |
|
break; |
265 |
|
} |
266 |
|
} |
267 |
|
} |
268 |
+ |
return s; |
269 |
|
} |
270 |
|
|
271 |
|
/** |
272 |
< |
* Handles interruptions during waits. |
273 |
< |
*/ |
361 |
< |
private void onInterruptedWait() { |
362 |
< |
ForkJoinWorkerThread w = getWorker(); |
363 |
< |
if (w == null) |
364 |
< |
Thread.currentThread().interrupt(); // re-interrupt |
365 |
< |
else if (w.isTerminating()) |
366 |
< |
cancelIgnoringExceptions(); |
367 |
< |
// else if FJworker, ignore interrupt |
368 |
< |
} |
369 |
< |
|
370 |
< |
// Recording and reporting exceptions |
371 |
< |
|
372 |
< |
private void setDoneExceptionally(Throwable rex) { |
373 |
< |
exceptionMap.put(this, rex); |
374 |
< |
setCompletion(EXCEPTIONAL); |
375 |
< |
} |
376 |
< |
|
377 |
< |
/** |
378 |
< |
* Throws the exception associated with status s. |
379 |
< |
* |
380 |
< |
* @throws the exception |
272 |
> |
* Unless done, calls exec and records status if completed, but |
273 |
> |
* doesn't wait for completion otherwise. |
274 |
|
*/ |
275 |
< |
private void reportException(int s) { |
276 |
< |
if ((s &= COMPLETION_MASK) < NORMAL) { |
277 |
< |
if (s == CANCELLED) |
278 |
< |
throw new CancellationException(); |
279 |
< |
else |
280 |
< |
rethrowException(exceptionMap.get(this)); |
275 |
> |
final void tryExec() { |
276 |
> |
try { |
277 |
> |
if (status < 0 || !exec()) |
278 |
> |
return; |
279 |
> |
} catch (Throwable rex) { |
280 |
> |
setExceptionalCompletion(rex); |
281 |
> |
return; |
282 |
|
} |
283 |
+ |
setCompletion(NORMAL); // must be outside try block |
284 |
|
} |
285 |
|
|
286 |
|
/** |
287 |
< |
* Returns result or throws exception using j.u.c.Future conventions. |
288 |
< |
* Only call when {@code isDone} known to be true or thread known |
289 |
< |
* to be interrupted. |
287 |
> |
* If not done and this task is next in worker queue, runs it, |
288 |
> |
* else waits for it. |
289 |
> |
* @return status on exit |
290 |
|
*/ |
291 |
< |
private V reportFutureResult() |
292 |
< |
throws InterruptedException, ExecutionException { |
293 |
< |
if (Thread.interrupted()) |
294 |
< |
throw new InterruptedException(); |
295 |
< |
int s = status & COMPLETION_MASK; |
296 |
< |
if (s < NORMAL) { |
297 |
< |
Throwable ex; |
298 |
< |
if (s == CANCELLED) |
299 |
< |
throw new CancellationException(); |
300 |
< |
if (s == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
301 |
< |
throw new ExecutionException(ex); |
291 |
> |
private int waitingJoin() { |
292 |
> |
int s = status; |
293 |
> |
if (s < 0) |
294 |
> |
return s; |
295 |
> |
Thread t = Thread.currentThread(); |
296 |
> |
if (t instanceof ForkJoinWorkerThread) { |
297 |
> |
ForkJoinWorkerThread w = (ForkJoinWorkerThread) t; |
298 |
> |
if (w.unpushTask(this)) { |
299 |
> |
boolean completed; |
300 |
> |
try { |
301 |
> |
completed = exec(); |
302 |
> |
} catch (Throwable rex) { |
303 |
> |
return setExceptionalCompletion(rex); |
304 |
> |
} |
305 |
> |
if (completed) |
306 |
> |
return setCompletion(NORMAL); |
307 |
> |
} |
308 |
> |
return w.pool.awaitJoin(this); |
309 |
|
} |
408 |
– |
return getRawResult(); |
409 |
– |
} |
410 |
– |
|
411 |
– |
/** |
412 |
– |
* Returns result or throws exception using j.u.c.Future conventions |
413 |
– |
* with timeouts. |
414 |
– |
*/ |
415 |
– |
private V reportTimedFutureResult() |
416 |
– |
throws InterruptedException, ExecutionException, TimeoutException { |
417 |
– |
if (Thread.interrupted()) |
418 |
– |
throw new InterruptedException(); |
419 |
– |
Throwable ex; |
420 |
– |
int s = status & COMPLETION_MASK; |
421 |
– |
if (s == NORMAL) |
422 |
– |
return getRawResult(); |
423 |
– |
else if (s == CANCELLED) |
424 |
– |
throw new CancellationException(); |
425 |
– |
else if (s == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
426 |
– |
throw new ExecutionException(ex); |
310 |
|
else |
311 |
< |
throw new TimeoutException(); |
311 |
> |
return externalAwaitDone(); |
312 |
|
} |
313 |
|
|
431 |
– |
// internal execution methods |
432 |
– |
|
314 |
|
/** |
315 |
< |
* Calls exec, recording completion, and rethrowing exception if |
316 |
< |
* encountered. Caller should normally check status before calling. |
317 |
< |
* |
437 |
< |
* @return true if completed normally |
315 |
> |
* Unless done, calls exec and records status if completed, or |
316 |
> |
* waits for completion otherwise. |
317 |
> |
* @return status on exit |
318 |
|
*/ |
319 |
< |
private boolean tryExec() { |
320 |
< |
try { // try block must contain only call to exec |
321 |
< |
if (!exec()) |
322 |
< |
return false; |
319 |
> |
private int waitingInvoke() { |
320 |
> |
int s = status; |
321 |
> |
if (s < 0) |
322 |
> |
return s; |
323 |
> |
boolean completed; |
324 |
> |
try { |
325 |
> |
completed = exec(); |
326 |
|
} catch (Throwable rex) { |
327 |
< |
setDoneExceptionally(rex); |
445 |
< |
rethrowException(rex); |
446 |
< |
return false; // not reached |
327 |
> |
return setExceptionalCompletion(rex); |
328 |
|
} |
329 |
< |
setNormalCompletion(); |
330 |
< |
return true; |
329 |
> |
if (completed) |
330 |
> |
return setCompletion(NORMAL); |
331 |
> |
return waitingJoin(); |
332 |
|
} |
333 |
|
|
334 |
|
/** |
335 |
< |
* Main execution method used by worker threads. Invokes |
336 |
< |
* base computation unless already complete. |
335 |
> |
* If this task is next in worker queue, runs it, else processes other |
336 |
> |
* tasks until complete. |
337 |
> |
* @return status on exit |
338 |
|
*/ |
339 |
< |
final void quietlyExec() { |
340 |
< |
if (status >= 0) { |
339 |
> |
private int busyJoin() { |
340 |
> |
int s = status; |
341 |
> |
if (s < 0) |
342 |
> |
return s; |
343 |
> |
ForkJoinWorkerThread w = (ForkJoinWorkerThread) Thread.currentThread(); |
344 |
> |
if (w.unpushTask(this)) { |
345 |
> |
boolean completed; |
346 |
|
try { |
347 |
< |
if (!exec()) |
460 |
< |
return; |
347 |
> |
completed = exec(); |
348 |
|
} catch (Throwable rex) { |
349 |
< |
setDoneExceptionally(rex); |
463 |
< |
return; |
349 |
> |
return setExceptionalCompletion(rex); |
350 |
|
} |
351 |
< |
setNormalCompletion(); |
352 |
< |
} |
467 |
< |
} |
468 |
< |
|
469 |
< |
/** |
470 |
< |
* Calls exec(), recording but not rethrowing exception. |
471 |
< |
* Caller should normally check status before calling. |
472 |
< |
* |
473 |
< |
* @return true if completed normally |
474 |
< |
*/ |
475 |
< |
private boolean tryQuietlyInvoke() { |
476 |
< |
try { |
477 |
< |
if (!exec()) |
478 |
< |
return false; |
479 |
< |
} catch (Throwable rex) { |
480 |
< |
setDoneExceptionally(rex); |
481 |
< |
return false; |
482 |
< |
} |
483 |
< |
setNormalCompletion(); |
484 |
< |
return true; |
485 |
< |
} |
486 |
< |
|
487 |
< |
/** |
488 |
< |
* Cancels, ignoring any exceptions it throws. |
489 |
< |
*/ |
490 |
< |
final void cancelIgnoringExceptions() { |
491 |
< |
try { |
492 |
< |
cancel(false); |
493 |
< |
} catch (Throwable ignore) { |
351 |
> |
if (completed) |
352 |
> |
return setCompletion(NORMAL); |
353 |
|
} |
354 |
+ |
return w.execWhileJoining(this); |
355 |
|
} |
356 |
|
|
357 |
|
/** |
358 |
< |
* Main implementation of helpJoin |
358 |
> |
* Returns result or throws exception associated with given status. |
359 |
> |
* @param s the status |
360 |
|
*/ |
361 |
< |
private int busyJoin(ForkJoinWorkerThread w) { |
362 |
< |
int s; |
363 |
< |
ForkJoinTask<?> t; |
364 |
< |
while ((s = status) >= 0 && (t = w.scanWhileJoining(this)) != null) |
365 |
< |
t.quietlyExec(); |
505 |
< |
return (s >= 0) ? awaitDone(w, false) : s; // block if no work |
361 |
> |
private V reportResult(int s) { |
362 |
> |
Throwable ex; |
363 |
> |
if (s < NORMAL && (ex = getException()) != null) |
364 |
> |
UNSAFE.throwException(ex); |
365 |
> |
return getRawResult(); |
366 |
|
} |
367 |
|
|
368 |
|
// public methods |
400 |
|
* @return the computed result |
401 |
|
*/ |
402 |
|
public final V join() { |
403 |
< |
ForkJoinWorkerThread w = getWorker(); |
544 |
< |
if (w == null || status < 0 || !w.unpushTask(this) || !tryExec()) |
545 |
< |
reportException(awaitDone(w, true)); |
546 |
< |
return getRawResult(); |
403 |
> |
return reportResult(waitingJoin()); |
404 |
|
} |
405 |
|
|
406 |
|
/** |
411 |
|
* @return the computed result |
412 |
|
*/ |
413 |
|
public final V invoke() { |
414 |
< |
if (status >= 0 && tryExec()) |
558 |
< |
return getRawResult(); |
559 |
< |
else |
560 |
< |
return join(); |
414 |
> |
return reportResult(waitingInvoke()); |
415 |
|
} |
416 |
|
|
417 |
|
/** |
469 |
|
} |
470 |
|
else if (i != 0) |
471 |
|
t.fork(); |
472 |
< |
else { |
473 |
< |
t.quietlyInvoke(); |
620 |
< |
if (ex == null) |
621 |
< |
ex = t.getException(); |
622 |
< |
} |
472 |
> |
else if (t.waitingInvoke() < NORMAL && ex == null) |
473 |
> |
ex = t.getException(); |
474 |
|
} |
475 |
|
for (int i = 1; i <= last; ++i) { |
476 |
|
ForkJoinTask<?> t = tasks[i]; |
477 |
|
if (t != null) { |
478 |
|
if (ex != null) |
479 |
|
t.cancel(false); |
480 |
< |
else { |
481 |
< |
t.quietlyJoin(); |
631 |
< |
if (ex == null) |
632 |
< |
ex = t.getException(); |
633 |
< |
} |
480 |
> |
else if (t.waitingJoin() < NORMAL && ex == null) |
481 |
> |
ex = t.getException(); |
482 |
|
} |
483 |
|
} |
484 |
|
if (ex != null) |
485 |
< |
rethrowException(ex); |
485 |
> |
UNSAFE.throwException(ex); |
486 |
|
} |
487 |
|
|
488 |
|
/** |
525 |
|
} |
526 |
|
else if (i != 0) |
527 |
|
t.fork(); |
528 |
< |
else { |
529 |
< |
t.quietlyInvoke(); |
682 |
< |
if (ex == null) |
683 |
< |
ex = t.getException(); |
684 |
< |
} |
528 |
> |
else if (t.waitingInvoke() < NORMAL && ex == null) |
529 |
> |
ex = t.getException(); |
530 |
|
} |
531 |
|
for (int i = 1; i <= last; ++i) { |
532 |
|
ForkJoinTask<?> t = ts.get(i); |
533 |
|
if (t != null) { |
534 |
|
if (ex != null) |
535 |
|
t.cancel(false); |
536 |
< |
else { |
537 |
< |
t.quietlyJoin(); |
693 |
< |
if (ex == null) |
694 |
< |
ex = t.getException(); |
695 |
< |
} |
536 |
> |
else if (t.waitingJoin() < NORMAL && ex == null) |
537 |
> |
ex = t.getException(); |
538 |
|
} |
539 |
|
} |
540 |
|
if (ex != null) |
541 |
< |
rethrowException(ex); |
541 |
> |
UNSAFE.throwException(ex); |
542 |
|
return tasks; |
543 |
|
} |
544 |
|
|
571 |
|
return (status & COMPLETION_MASK) == CANCELLED; |
572 |
|
} |
573 |
|
|
574 |
+ |
/** |
575 |
+ |
* Cancels, ignoring any exceptions it throws. Used during worker |
576 |
+ |
* and pool shutdown. |
577 |
+ |
*/ |
578 |
+ |
final void cancelIgnoringExceptions() { |
579 |
+ |
try { |
580 |
+ |
cancel(false); |
581 |
+ |
} catch (Throwable ignore) { |
582 |
+ |
} |
583 |
+ |
} |
584 |
+ |
|
585 |
+ |
/** |
586 |
+ |
* Cancels ignoring exceptions if worker is terminating |
587 |
+ |
*/ |
588 |
+ |
private void cancelIfTerminating() { |
589 |
+ |
Thread t = Thread.currentThread(); |
590 |
+ |
if ((t instanceof ForkJoinWorkerThread) && |
591 |
+ |
((ForkJoinWorkerThread) t).isTerminating()) { |
592 |
+ |
try { |
593 |
+ |
cancel(false); |
594 |
+ |
} catch (Throwable ignore) { |
595 |
+ |
} |
596 |
+ |
} |
597 |
+ |
} |
598 |
+ |
|
599 |
|
public final boolean isDone() { |
600 |
|
return status < 0; |
601 |
|
} |
653 |
|
* thrown will be a {@code RuntimeException} with cause {@code ex}. |
654 |
|
*/ |
655 |
|
public void completeExceptionally(Throwable ex) { |
656 |
< |
setDoneExceptionally((ex instanceof RuntimeException) || |
657 |
< |
(ex instanceof Error) ? ex : |
658 |
< |
new RuntimeException(ex)); |
656 |
> |
setExceptionalCompletion((ex instanceof RuntimeException) || |
657 |
> |
(ex instanceof Error) ? ex : |
658 |
> |
new RuntimeException(ex)); |
659 |
|
} |
660 |
|
|
661 |
|
/** |
674 |
|
try { |
675 |
|
setRawResult(value); |
676 |
|
} catch (Throwable rex) { |
677 |
< |
setDoneExceptionally(rex); |
677 |
> |
setExceptionalCompletion(rex); |
678 |
|
return; |
679 |
|
} |
680 |
< |
setNormalCompletion(); |
680 |
> |
setCompletion(NORMAL); |
681 |
|
} |
682 |
|
|
683 |
|
public final V get() throws InterruptedException, ExecutionException { |
684 |
< |
ForkJoinWorkerThread w = getWorker(); |
685 |
< |
if (w == null || status < 0 || !w.unpushTask(this) || !tryQuietlyInvoke()) |
686 |
< |
awaitDone(w, true); |
687 |
< |
return reportFutureResult(); |
684 |
> |
int s = waitingJoin() & COMPLETION_MASK; |
685 |
> |
if (Thread.interrupted()) |
686 |
> |
throw new InterruptedException(); |
687 |
> |
if (s < NORMAL) { |
688 |
> |
Throwable ex; |
689 |
> |
if (s == CANCELLED) |
690 |
> |
throw new CancellationException(); |
691 |
> |
if (s == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
692 |
> |
throw new ExecutionException(ex); |
693 |
> |
} |
694 |
> |
return getRawResult(); |
695 |
|
} |
696 |
|
|
697 |
|
public final V get(long timeout, TimeUnit unit) |
698 |
|
throws InterruptedException, ExecutionException, TimeoutException { |
699 |
< |
long nanos = unit.toNanos(timeout); |
700 |
< |
ForkJoinWorkerThread w = getWorker(); |
701 |
< |
if (w == null || status < 0 || !w.unpushTask(this) || !tryQuietlyInvoke()) |
702 |
< |
awaitDone(w, nanos); |
703 |
< |
return reportTimedFutureResult(); |
699 |
> |
Thread t = Thread.currentThread(); |
700 |
> |
ForkJoinPool pool; |
701 |
> |
if (t instanceof ForkJoinWorkerThread) { |
702 |
> |
ForkJoinWorkerThread w = (ForkJoinWorkerThread) t; |
703 |
> |
if (status >= 0 && w.unpushTask(this)) |
704 |
> |
tryExec(); |
705 |
> |
pool = w.pool; |
706 |
> |
} |
707 |
> |
else |
708 |
> |
pool = null; |
709 |
> |
/* |
710 |
> |
* Timed wait loop intermixes cases for fj (pool != null) and |
711 |
> |
* non FJ threads. For FJ, decrement pool count but don't try |
712 |
> |
* for replacement; increment count on completion. For non-FJ, |
713 |
> |
* deal with interrupts. This is messy, but a little less so |
714 |
> |
* than is splitting the FJ and nonFJ cases. |
715 |
> |
*/ |
716 |
> |
boolean interrupted = false; |
717 |
> |
boolean dec = false; // true if pool count decremented |
718 |
> |
for (;;) { |
719 |
> |
if (Thread.interrupted() && pool == null) { |
720 |
> |
interrupted = true; |
721 |
> |
break; |
722 |
> |
} |
723 |
> |
int s = status; |
724 |
> |
if (s < 0) |
725 |
> |
break; |
726 |
> |
if (UNSAFE.compareAndSwapInt(this, statusOffset, |
727 |
> |
s, s | SIGNAL)) { |
728 |
> |
long startTime = System.nanoTime(); |
729 |
> |
long nanos = unit.toNanos(timeout); |
730 |
> |
long nt; // wait time |
731 |
> |
while (status >= 0 && |
732 |
> |
(nt = nanos - (System.nanoTime() - startTime)) > 0) { |
733 |
> |
if (pool != null && !dec) |
734 |
> |
dec = pool.tryDecrementRunningCount(); |
735 |
> |
else { |
736 |
> |
long ms = nt / 1000000; |
737 |
> |
int ns = (int) (nt % 1000000); |
738 |
> |
try { |
739 |
> |
synchronized(this) { |
740 |
> |
if (status >= 0) |
741 |
> |
wait(ms, ns); |
742 |
> |
} |
743 |
> |
} catch (InterruptedException ie) { |
744 |
> |
if (pool != null) |
745 |
> |
cancelIfTerminating(); |
746 |
> |
else { |
747 |
> |
interrupted = true; |
748 |
> |
break; |
749 |
> |
} |
750 |
> |
} |
751 |
> |
} |
752 |
> |
} |
753 |
> |
break; |
754 |
> |
} |
755 |
> |
} |
756 |
> |
if (pool != null && dec) |
757 |
> |
pool.updateRunningCount(1); |
758 |
> |
if (interrupted) |
759 |
> |
throw new InterruptedException(); |
760 |
> |
int es = status & COMPLETION_MASK; |
761 |
> |
if (es != NORMAL) { |
762 |
> |
Throwable ex; |
763 |
> |
if (es == CANCELLED) |
764 |
> |
throw new CancellationException(); |
765 |
> |
if (es == EXCEPTIONAL && (ex = exceptionMap.get(this)) != null) |
766 |
> |
throw new ExecutionException(ex); |
767 |
> |
throw new TimeoutException(); |
768 |
> |
} |
769 |
> |
return getRawResult(); |
770 |
|
} |
771 |
|
|
772 |
|
/** |
787 |
|
* @return the computed result |
788 |
|
*/ |
789 |
|
public final V helpJoin() { |
790 |
< |
ForkJoinWorkerThread w = (ForkJoinWorkerThread) Thread.currentThread(); |
851 |
< |
if (status < 0 || !w.unpushTask(this) || !tryExec()) |
852 |
< |
reportException(busyJoin(w)); |
853 |
< |
return getRawResult(); |
790 |
> |
return reportResult(busyJoin()); |
791 |
|
} |
792 |
|
|
793 |
|
/** |
803 |
|
* ClassCastException}. |
804 |
|
*/ |
805 |
|
public final void quietlyHelpJoin() { |
806 |
< |
if (status >= 0) { |
870 |
< |
ForkJoinWorkerThread w = |
871 |
< |
(ForkJoinWorkerThread) Thread.currentThread(); |
872 |
< |
if (!w.unpushTask(this) || !tryQuietlyInvoke()) |
873 |
< |
busyJoin(w); |
874 |
< |
} |
806 |
> |
busyJoin(); |
807 |
|
} |
808 |
|
|
809 |
|
/** |
813 |
|
* known to have aborted. |
814 |
|
*/ |
815 |
|
public final void quietlyJoin() { |
816 |
< |
if (status >= 0) { |
885 |
< |
ForkJoinWorkerThread w = getWorker(); |
886 |
< |
if (w == null || !w.unpushTask(this) || !tryQuietlyInvoke()) |
887 |
< |
awaitDone(w, true); |
888 |
< |
} |
816 |
> |
waitingJoin(); |
817 |
|
} |
818 |
|
|
819 |
|
/** |
824 |
|
* known to have aborted. |
825 |
|
*/ |
826 |
|
public final void quietlyInvoke() { |
827 |
< |
if (status >= 0 && !tryQuietlyInvoke()) |
900 |
< |
quietlyJoin(); |
827 |
> |
waitingInvoke(); |
828 |
|
} |
829 |
|
|
830 |
|
/** |
1146 |
|
private static final long serialVersionUID = -7721805057305804111L; |
1147 |
|
|
1148 |
|
/** |
1149 |
< |
* Save the state to a stream. |
1149 |
> |
* Saves the state to a stream. |
1150 |
|
* |
1151 |
|
* @serialData the current run status and the exception thrown |
1152 |
|
* during execution, or {@code null} if none |
1159 |
|
} |
1160 |
|
|
1161 |
|
/** |
1162 |
< |
* Reconstitute the instance from a stream. |
1162 |
> |
* Reconstitutes the instance from a stream. |
1163 |
|
* |
1164 |
|
* @param s the stream |
1165 |
|
*/ |
1166 |
|
private void readObject(java.io.ObjectInputStream s) |
1167 |
|
throws java.io.IOException, ClassNotFoundException { |
1168 |
|
s.defaultReadObject(); |
1169 |
< |
status &= ~INTERNAL_SIGNAL_MASK; // clear internal signal counts |
1243 |
< |
status |= EXTERNAL_SIGNAL; // conservatively set external signal |
1169 |
> |
status |= SIGNAL; // conservatively set external signal |
1170 |
|
Object ex = s.readObject(); |
1171 |
|
if (ex != null) |
1172 |
< |
setDoneExceptionally((Throwable) ex); |
1172 |
> |
setExceptionalCompletion((Throwable) ex); |
1173 |
|
} |
1174 |
|
|
1175 |
|
// Unsafe mechanics |