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Comparing jsr166/src/jsr166y/ForkJoinTask.java (file contents):
Revision 1.9 by jsr166, Mon Jul 20 22:26:03 2009 UTC vs.
Revision 1.21 by jsr166, Sun Jul 26 06:26:37 2009 UTC

# Line 5 | Line 5
5   */
6  
7   package jsr166y;
8 < import java.io.Serializable;
9 < import java.util.*;
8 >
9   import java.util.concurrent.*;
10 < import java.util.concurrent.atomic.*;
11 < import sun.misc.Unsafe;
12 < import java.lang.reflect.*;
10 >
11 > import java.io.Serializable;
12 > import java.util.Collection;
13 > import java.util.Collections;
14 > import java.util.List;
15 > import java.util.Map;
16 > import java.util.WeakHashMap;
17  
18   /**
19   * Abstract base class for tasks that run within a {@link
# Line 81 | Line 84 | import java.lang.reflect.*;
84   * class. While these methods have {@code public} access (to allow
85   * instances of different task subclasses to call each others
86   * methods), some of them may only be called from within other
87 < * ForkJoinTasks. Attempts to invoke them in other contexts result in
88 < * exceptions or errors possibly including ClassCastException.
87 > * ForkJoinTasks (as may be determined using method {@link
88 > * #inForkJoinPool}).  Attempts to invoke them in other contexts
89 > * result in exceptions or errors, possibly including
90 > * ClassCastException.
91   *
92   * <p>Most base support methods are {@code final} because their
93   * implementations are intrinsically tied to the underlying
# Line 107 | Line 112 | import java.lang.reflect.*;
112   * in general sensible to serialize tasks only before or after, but
113   * not during execution. Serialization is not relied on during
114   * execution itself.
115 + *
116 + * @since 1.7
117 + * @author Doug Lea
118   */
119   public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
120  
# Line 141 | Line 149 | public abstract class ForkJoinTask<V> im
149      /**
150       * Table of exceptions thrown by tasks, to enable reporting by
151       * callers. Because exceptions are rare, we don't directly keep
152 <     * them with task objects, but instead us a weak ref table.  Note
152 >     * them with task objects, but instead use a weak ref table.  Note
153       * that cancellation exceptions don't appear in the table, but are
154       * instead recorded as status values.
155 <     * Todo: Use ConcurrentReferenceHashMap
155 >     * TODO: Use ConcurrentReferenceHashMap
156       */
157      static final Map<ForkJoinTask<?>, Throwable> exceptionMap =
158          Collections.synchronizedMap
# Line 153 | Line 161 | public abstract class ForkJoinTask<V> im
161      // within-package utilities
162  
163      /**
164 <     * Get current worker thread, or null if not a worker thread
164 >     * Gets current worker thread, or null if not a worker thread.
165       */
166      static ForkJoinWorkerThread getWorker() {
167          Thread t = Thread.currentThread();
168 <        return ((t instanceof ForkJoinWorkerThread)?
169 <                (ForkJoinWorkerThread)t : null);
168 >        return ((t instanceof ForkJoinWorkerThread) ?
169 >                (ForkJoinWorkerThread) t : null);
170      }
171  
172      final boolean casStatus(int cmp, int val) {
173 <        return _unsafe.compareAndSwapInt(this, statusOffset, cmp, val);
173 >        return UNSAFE.compareAndSwapInt(this, statusOffset, cmp, val);
174      }
175  
176      /**
# Line 170 | Line 178 | public abstract class ForkJoinTask<V> im
178       */
179      static void rethrowException(Throwable ex) {
180          if (ex != null)
181 <            _unsafe.throwException(ex);
181 >            UNSAFE.throwException(ex);
182      }
183  
184      // Setting completion status
185  
186      /**
187 <     * Mark completion and wake up threads waiting to join this task.
187 >     * Marks completion and wakes up threads waiting to join this task.
188 >     *
189       * @param completion one of NORMAL, CANCELLED, EXCEPTIONAL
190       */
191      final void setCompletion(int completion) {
192          ForkJoinPool pool = getPool();
193          if (pool != null) {
194              int s; // Clear signal bits while setting completion status
195 <            do;while ((s = status) >= 0 && !casStatus(s, completion));
195 >            do {} while ((s = status) >= 0 && !casStatus(s, completion));
196  
197              if ((s & SIGNAL_MASK) != 0) {
198                  if ((s &= INTERNAL_SIGNAL_MASK) != 0)
199                      pool.updateRunningCount(s);
200 <                synchronized(this) { notifyAll(); }
200 >                synchronized (this) { notifyAll(); }
201              }
202          }
203          else
# Line 201 | Line 210 | public abstract class ForkJoinTask<V> im
210       */
211      private void externallySetCompletion(int completion) {
212          int s;
213 <        do;while ((s = status) >= 0 &&
214 <                  !casStatus(s, (s & SIGNAL_MASK) | completion));
215 <        synchronized(this) { notifyAll(); }
213 >        do {} while ((s = status) >= 0 &&
214 >                     !casStatus(s, (s & SIGNAL_MASK) | completion));
215 >        synchronized (this) { notifyAll(); }
216      }
217  
218      /**
219 <     * Sets status to indicate normal completion
219 >     * Sets status to indicate normal completion.
220       */
221      final void setNormalCompletion() {
222          // Try typical fast case -- single CAS, no signal, not already done.
223          // Manually expand casStatus to improve chances of inlining it
224 <        if (!_unsafe.compareAndSwapInt(this, statusOffset, 0, NORMAL))
224 >        if (!UNSAFE.compareAndSwapInt(this, statusOffset, 0, NORMAL))
225              setCompletion(NORMAL);
226      }
227  
228      // internal waiting and notification
229  
230      /**
231 <     * Performs the actual monitor wait for awaitDone
231 >     * Performs the actual monitor wait for awaitDone.
232       */
233      private void doAwaitDone() {
234          // Minimize lock bias and in/de-flation effects by maximizing
235          // chances of waiting inside sync
236          try {
237              while (status >= 0)
238 <                synchronized(this) { if (status >= 0) wait(); }
238 >                synchronized (this) { if (status >= 0) wait(); }
239          } catch (InterruptedException ie) {
240              onInterruptedWait();
241          }
242      }
243  
244      /**
245 <     * Performs the actual monitor wait for awaitDone
245 >     * Performs the actual timed monitor wait for awaitDone.
246       */
247      private void doAwaitDone(long startTime, long nanos) {
248 <        synchronized(this) {
248 >        synchronized (this) {
249              try {
250                  while (status >= 0) {
251                      long nt = nanos - System.nanoTime() - startTime;
252                      if (nt <= 0)
253                          break;
254 <                    wait(nt / 1000000, (int)(nt % 1000000));
254 >                    wait(nt / 1000000, (int) (nt % 1000000));
255                  }
256              } catch (InterruptedException ie) {
257                  onInterruptedWait();
# Line 255 | Line 264 | public abstract class ForkJoinTask<V> im
264      /**
265       * Sets status to indicate there is joiner, then waits for join,
266       * surrounded with pool notifications.
267 +     *
268       * @return status upon exit
269       */
270 <    private int awaitDone(ForkJoinWorkerThread w, boolean maintainParallelism) {
271 <        ForkJoinPool pool = w == null? null : w.pool;
270 >    private int awaitDone(ForkJoinWorkerThread w,
271 >                          boolean maintainParallelism) {
272 >        ForkJoinPool pool = (w == null) ? null : w.pool;
273          int s;
274          while ((s = status) >= 0) {
275 <            if (casStatus(s, pool == null? s|EXTERNAL_SIGNAL : s+1)) {
275 >            if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) {
276                  if (pool == null || !pool.preJoin(this, maintainParallelism))
277                      doAwaitDone();
278                  if (((s = status) & INTERNAL_SIGNAL_MASK) != 0)
# Line 274 | Line 285 | public abstract class ForkJoinTask<V> im
285  
286      /**
287       * Timed version of awaitDone
288 +     *
289       * @return status upon exit
290       */
291      private int awaitDone(ForkJoinWorkerThread w, long nanos) {
292 <        ForkJoinPool pool = w == null? null : w.pool;
292 >        ForkJoinPool pool = (w == null) ? null : w.pool;
293          int s;
294          while ((s = status) >= 0) {
295 <            if (casStatus(s, pool == null? s|EXTERNAL_SIGNAL : s+1)) {
295 >            if (casStatus(s, (pool == null) ? s|EXTERNAL_SIGNAL : s+1)) {
296                  long startTime = System.nanoTime();
297                  if (pool == null || !pool.preJoin(this, false))
298                      doAwaitDone(startTime, nanos);
# Line 297 | Line 309 | public abstract class ForkJoinTask<V> im
309      }
310  
311      /**
312 <     * Notify pool that thread is unblocked. Called by signalled
312 >     * Notifies pool that thread is unblocked. Called by signalled
313       * threads when woken by non-FJ threads (which is atypical).
314       */
315      private void adjustPoolCountsOnUnblock(ForkJoinPool pool) {
316          int s;
317 <        do;while ((s = status) < 0 && !casStatus(s, s & COMPLETION_MASK));
317 >        do {} while ((s = status) < 0 && !casStatus(s, s & COMPLETION_MASK));
318          if (pool != null && (s &= INTERNAL_SIGNAL_MASK) != 0)
319              pool.updateRunningCount(s);
320      }
321  
322      /**
323 <     * Notify pool to adjust counts on cancelled or timed out wait
323 >     * Notifies pool to adjust counts on cancelled or timed out wait.
324       */
325      private void adjustPoolCountsOnCancelledWait(ForkJoinPool pool) {
326          if (pool != null) {
# Line 323 | Line 335 | public abstract class ForkJoinTask<V> im
335      }
336  
337      /**
338 <     * Handle interruptions during waits.
338 >     * Handles interruptions during waits.
339       */
340      private void onInterruptedWait() {
341          ForkJoinWorkerThread w = getWorker();
# Line 342 | Line 354 | public abstract class ForkJoinTask<V> im
354      }
355  
356      /**
357 <     * Throws the exception associated with status s;
357 >     * Throws the exception associated with status s.
358 >     *
359       * @throws the exception
360       */
361      private void reportException(int s) {
# Line 355 | Line 368 | public abstract class ForkJoinTask<V> im
368      }
369  
370      /**
371 <     * Returns result or throws exception using j.u.c.Future conventions
372 <     * Only call when isDone known to be true.
371 >     * Returns result or throws exception using j.u.c.Future conventions.
372 >     * Only call when {@code isDone} known to be true.
373       */
374      private V reportFutureResult()
375          throws ExecutionException, InterruptedException {
# Line 375 | Line 388 | public abstract class ForkJoinTask<V> im
388  
389      /**
390       * Returns result or throws exception using j.u.c.Future conventions
391 <     * with timeouts
391 >     * with timeouts.
392       */
393      private V reportTimedFutureResult()
394          throws InterruptedException, ExecutionException, TimeoutException {
# Line 396 | Line 409 | public abstract class ForkJoinTask<V> im
409  
410      /**
411       * Calls exec, recording completion, and rethrowing exception if
412 <     * encountered. Caller should normally check status before calling
412 >     * encountered. Caller should normally check status before calling.
413 >     *
414       * @return true if completed normally
415       */
416      private boolean tryExec() {
# Line 414 | Line 428 | public abstract class ForkJoinTask<V> im
428  
429      /**
430       * Main execution method used by worker threads. Invokes
431 <     * base computation unless already complete
431 >     * base computation unless already complete.
432       */
433      final void quietlyExec() {
434          if (status >= 0) {
435              try {
436                  if (!exec())
437                      return;
438 <            } catch(Throwable rex) {
438 >            } catch (Throwable rex) {
439                  setDoneExceptionally(rex);
440                  return;
441              }
# Line 430 | Line 444 | public abstract class ForkJoinTask<V> im
444      }
445  
446      /**
447 <     * Calls exec, recording but not rethrowing exception
448 <     * Caller should normally check status before calling
447 >     * Calls exec(), recording but not rethrowing exception.
448 >     * Caller should normally check status before calling.
449 >     *
450       * @return true if completed normally
451       */
452      private boolean tryQuietlyInvoke() {
# Line 447 | Line 462 | public abstract class ForkJoinTask<V> im
462      }
463  
464      /**
465 <     * Cancel, ignoring any exceptions it throws
465 >     * Cancels, ignoring any exceptions it throws.
466       */
467      final void cancelIgnoringExceptions() {
468          try {
469              cancel(false);
470 <        } catch(Throwable ignore) {
470 >        } catch (Throwable ignore) {
471          }
472      }
473  
# Line 464 | Line 479 | public abstract class ForkJoinTask<V> im
479          ForkJoinTask<?> t;
480          while ((s = status) >= 0 && (t = w.scanWhileJoining(this)) != null)
481              t.quietlyExec();
482 <        return (s >= 0)? awaitDone(w, false) : s; // block if no work
482 >        return (s >= 0) ? awaitDone(w, false) : s; // block if no work
483      }
484  
485      // public methods
# Line 474 | Line 489 | public abstract class ForkJoinTask<V> im
489       * necessarily enforced, it is a usage error to fork a task more
490       * than once unless it has completed and been reinitialized.  This
491       * method may be invoked only from within ForkJoinTask
492 <     * computations. Attempts to invoke in other contexts result in
493 <     * exceptions or errors possibly including ClassCastException.
492 >     * computations (as may be determined using method {@link
493 >     * #inForkJoinPool}). Attempts to invoke in other contexts result
494 >     * in exceptions or errors, possibly including ClassCastException.
495 >     *
496 >     * @return {@code this}, to simplify usage.
497       */
498 <    public final void fork() {
499 <        ((ForkJoinWorkerThread)(Thread.currentThread())).pushTask(this);
498 >    public final ForkJoinTask<V> fork() {
499 >        ((ForkJoinWorkerThread) Thread.currentThread())
500 >            .pushTask(this);
501 >        return this;
502      }
503  
504      /**
# Line 499 | Line 519 | public abstract class ForkJoinTask<V> im
519      /**
520       * Commences performing this task, awaits its completion if
521       * necessary, and return its result.
522 +     *
523       * @throws Throwable (a RuntimeException, Error, or unchecked
524 <     * exception) if the underlying computation did so.
524 >     * exception) if the underlying computation did so
525       * @return the computed result
526       */
527      public final V invoke() {
# Line 513 | Line 534 | public abstract class ForkJoinTask<V> im
534      /**
535       * Forks both tasks, returning when {@code isDone} holds for
536       * both of them or an exception is encountered. This method may be
537 <     * invoked only from within ForkJoinTask computations. Attempts to
538 <     * invoke in other contexts result in exceptions or errors
537 >     * invoked only from within ForkJoinTask computations (as may be
538 >     * determined using method {@link #inForkJoinPool}). Attempts to
539 >     * invoke in other contexts result in exceptions or errors,
540       * possibly including ClassCastException.
541 +     *
542       * @param t1 one task
543       * @param t2 the other task
544       * @throws NullPointerException if t1 or t2 are null
545 <     * @throws RuntimeException or Error if either task did so.
545 >     * @throws RuntimeException or Error if either task did so
546       */
547      public static void invokeAll(ForkJoinTask<?>t1, ForkJoinTask<?> t2) {
548          t2.fork();
# Line 531 | Line 554 | public abstract class ForkJoinTask<V> im
554       * Forks the given tasks, returning when {@code isDone} holds
555       * for all of them. If any task encounters an exception, others
556       * may be cancelled.  This method may be invoked only from within
557 <     * ForkJoinTask computations. Attempts to invoke in other contexts
558 <     * result in exceptions or errors possibly including ClassCastException.
557 >     * ForkJoinTask computations (as may be determined using method
558 >     * {@link #inForkJoinPool}). Attempts to invoke in other contexts
559 >     * result in exceptions or errors, possibly including
560 >     * ClassCastException.
561 >     *
562       * @param tasks the array of tasks
563 <     * @throws NullPointerException if tasks or any element are null.
564 <     * @throws RuntimeException or Error if any task did so.
563 >     * @throws NullPointerException if tasks or any element are null
564 >     * @throws RuntimeException or Error if any task did so
565       */
566      public static void invokeAll(ForkJoinTask<?>... tasks) {
567          Throwable ex = null;
# Line 574 | Line 600 | public abstract class ForkJoinTask<V> im
600       * Forks all tasks in the collection, returning when
601       * {@code isDone} holds for all of them. If any task
602       * encounters an exception, others may be cancelled.  This method
603 <     * may be invoked only from within ForkJoinTask
604 <     * computations. Attempts to invoke in other contexts result in
605 <     * exceptions or errors possibly including ClassCastException.
603 >     * may be invoked only from within ForkJoinTask computations (as
604 >     * may be determined using method {@link
605 >     * #inForkJoinPool}). Attempts to invoke in other contexts result
606 >     * in exceptions or errors, possibly including ClassCastException.
607 >     *
608       * @param tasks the collection of tasks
609 <     * @throws NullPointerException if tasks or any element are null.
610 <     * @throws RuntimeException or Error if any task did so.
611 <     */
612 <    public static void invokeAll(Collection<? extends ForkJoinTask<?>> tasks) {
613 <        if (!(tasks instanceof List)) {
614 <            invokeAll(tasks.toArray(new ForkJoinTask[tasks.size()]));
615 <            return;
609 >     * @return the tasks argument, to simplify usage
610 >     * @throws NullPointerException if tasks or any element are null
611 >     * @throws RuntimeException or Error if any task did so
612 >     */
613 >    public static <T extends ForkJoinTask<?>> Collection<T> invokeAll(Collection<T> tasks) {
614 >        if (!(tasks instanceof List<?>)) {
615 >            invokeAll(tasks.toArray(new ForkJoinTask<?>[tasks.size()]));
616 >            return tasks;
617          }
618 +        @SuppressWarnings("unchecked")
619          List<? extends ForkJoinTask<?>> ts =
620 <            (List<? extends ForkJoinTask<?>>)tasks;
620 >            (List<? extends ForkJoinTask<?>>) tasks;
621          Throwable ex = null;
622          int last = ts.size() - 1;
623          for (int i = last; i >= 0; --i) {
# Line 618 | Line 648 | public abstract class ForkJoinTask<V> im
648          }
649          if (ex != null)
650              rethrowException(ex);
651 +        return tasks;
652      }
653  
654      /**
655       * Returns true if the computation performed by this task has
656       * completed (or has been cancelled).
657 +     *
658       * @return true if this computation has completed
659       */
660      public final boolean isDone() {
# Line 631 | Line 663 | public abstract class ForkJoinTask<V> im
663  
664      /**
665       * Returns true if this task was cancelled.
666 +     *
667       * @return true if this task was cancelled
668       */
669      public final boolean isCancelled() {
# Line 660 | Line 693 | public abstract class ForkJoinTask<V> im
693       *
694       * @param mayInterruptIfRunning this value is ignored in the
695       * default implementation because tasks are not in general
696 <     * cancelled via interruption.
696 >     * cancelled via interruption
697       *
698       * @return true if this task is now cancelled
699       */
# Line 670 | Line 703 | public abstract class ForkJoinTask<V> im
703      }
704  
705      /**
706 <     * Returns true if this task threw an exception or was cancelled
706 >     * Returns true if this task threw an exception or was cancelled.
707 >     *
708       * @return true if this task threw an exception or was cancelled
709       */
710      public final boolean isCompletedAbnormally() {
# Line 681 | Line 715 | public abstract class ForkJoinTask<V> im
715       * Returns the exception thrown by the base computation, or a
716       * CancellationException if cancelled, or null if none or if the
717       * method has not yet completed.
718 +     *
719       * @return the exception, or null if none
720       */
721      public final Throwable getException() {
# Line 708 | Line 743 | public abstract class ForkJoinTask<V> im
743       */
744      public void completeExceptionally(Throwable ex) {
745          setDoneExceptionally((ex instanceof RuntimeException) ||
746 <                             (ex instanceof Error)? ex :
746 >                             (ex instanceof Error) ? ex :
747                               new RuntimeException(ex));
748      }
749  
# Line 722 | Line 757 | public abstract class ForkJoinTask<V> im
757       * overridable, but overridden versions must invoke {@code super}
758       * implementation to maintain guarantees.
759       *
760 <     * @param value the result value for this task.
760 >     * @param value the result value for this task
761       */
762      public void complete(V value) {
763          try {
764              setRawResult(value);
765 <        } catch(Throwable rex) {
765 >        } catch (Throwable rex) {
766              setDoneExceptionally(rex);
767              return;
768          }
# Line 757 | Line 792 | public abstract class ForkJoinTask<V> im
792       * current task and that of any other task that might be executed
793       * while helping. (This usually holds for pure divide-and-conquer
794       * tasks). This method may be invoked only from within
795 <     * ForkJoinTask computations. Attempts to invoke in other contexts
796 <     * result in exceptions or errors possibly including ClassCastException.
795 >     * ForkJoinTask computations (as may be determined using method
796 >     * {@link #inForkJoinPool}). Attempts to invoke in other contexts
797 >     * result in exceptions or errors, possibly including
798 >     * ClassCastException.
799 >     *
800       * @return the computed result
801       */
802      public final V helpJoin() {
803 <        ForkJoinWorkerThread w = (ForkJoinWorkerThread)(Thread.currentThread());
803 >        ForkJoinWorkerThread w = (ForkJoinWorkerThread) Thread.currentThread();
804          if (status < 0 || !w.unpushTask(this) || !tryExec())
805              reportException(busyJoin(w));
806          return getRawResult();
# Line 771 | Line 809 | public abstract class ForkJoinTask<V> im
809      /**
810       * Possibly executes other tasks until this task is ready.  This
811       * method may be invoked only from within ForkJoinTask
812 <     * computations. Attempts to invoke in other contexts result in
813 <     * exceptions or errors possibly including ClassCastException.
812 >     * computations (as may be determined using method {@link
813 >     * #inForkJoinPool}). Attempts to invoke in other contexts result
814 >     * in exceptions or errors, possibly including ClassCastException.
815       */
816      public final void quietlyHelpJoin() {
817          if (status >= 0) {
818              ForkJoinWorkerThread w =
819 <                (ForkJoinWorkerThread)(Thread.currentThread());
819 >                (ForkJoinWorkerThread) Thread.currentThread();
820              if (!w.unpushTask(this) || !tryQuietlyInvoke())
821                  busyJoin(w);
822          }
# Line 816 | Line 855 | public abstract class ForkJoinTask<V> im
855       * joined, instead executing them until all are processed.
856       */
857      public static void helpQuiesce() {
858 <        ((ForkJoinWorkerThread)(Thread.currentThread())).
859 <            helpQuiescePool();
858 >        ((ForkJoinWorkerThread) Thread.currentThread())
859 >            .helpQuiescePool();
860      }
861  
862      /**
# Line 838 | Line 877 | public abstract class ForkJoinTask<V> im
877  
878      /**
879       * Returns the pool hosting the current task execution, or null
880 <     * if this task is executing outside of any pool.
881 <     * @return the pool, or null if none.
880 >     * if this task is executing outside of any ForkJoinPool.
881 >     *
882 >     * @return the pool, or null if none
883       */
884      public static ForkJoinPool getPool() {
885          Thread t = Thread.currentThread();
886 <        return ((t instanceof ForkJoinWorkerThread)?
887 <                ((ForkJoinWorkerThread)t).pool : null);
886 >        return (t instanceof ForkJoinWorkerThread) ?
887 >            ((ForkJoinWorkerThread) t).pool : null;
888 >    }
889 >
890 >    /**
891 >     * Returns {@code true} if the current thread is executing as a
892 >     * ForkJoinPool computation.
893 >     *
894 >     * @return {@code true} if the current thread is executing as a
895 >     * ForkJoinPool computation, or false otherwise
896 >     */
897 >    public static boolean inForkJoinPool() {
898 >        return Thread.currentThread() instanceof ForkJoinWorkerThread;
899      }
900  
901      /**
# Line 854 | Line 905 | public abstract class ForkJoinTask<V> im
905       * another thread.  This method may be useful when arranging
906       * alternative local processing of tasks that could have been, but
907       * were not, stolen. This method may be invoked only from within
908 <     * ForkJoinTask computations. Attempts to invoke in other contexts
909 <     * result in exceptions or errors possibly including ClassCastException.
908 >     * ForkJoinTask computations (as may be determined using method
909 >     * {@link #inForkJoinPool}). Attempts to invoke in other contexts
910 >     * result in exceptions or errors, possibly including
911 >     * ClassCastException.
912 >     *
913       * @return true if unforked
914       */
915      public boolean tryUnfork() {
916 <        return ((ForkJoinWorkerThread)(Thread.currentThread())).unpushTask(this);
916 >        return ((ForkJoinWorkerThread) Thread.currentThread())
917 >            .unpushTask(this);
918      }
919  
920      /**
# Line 867 | Line 922 | public abstract class ForkJoinTask<V> im
922       * forked by the current worker thread but not yet executed. This
923       * value may be useful for heuristic decisions about whether to
924       * fork other tasks.
925 +     *
926       * @return the number of tasks
927       */
928      public static int getQueuedTaskCount() {
929 <        return ((ForkJoinWorkerThread)(Thread.currentThread())).
930 <            getQueueSize();
929 >        return ((ForkJoinWorkerThread) Thread.currentThread())
930 >            .getQueueSize();
931      }
932  
933      /**
934 <     * Returns a estimate of how many more locally queued tasks are
934 >     * Returns an estimate of how many more locally queued tasks are
935       * held by the current worker thread than there are other worker
936       * threads that might steal them.  This value may be useful for
937       * heuristic decisions about whether to fork other tasks. In many
# Line 883 | Line 939 | public abstract class ForkJoinTask<V> im
939       * aim to maintain a small constant surplus (for example, 3) of
940       * tasks, and to process computations locally if this threshold is
941       * exceeded.
942 +     *
943       * @return the surplus number of tasks, which may be negative
944       */
945      public static int getSurplusQueuedTaskCount() {
946 <        return ((ForkJoinWorkerThread)(Thread.currentThread()))
946 >        return ((ForkJoinWorkerThread) Thread.currentThread())
947              .getEstimatedSurplusTaskCount();
948      }
949  
# Line 899 | Line 956 | public abstract class ForkJoinTask<V> im
956       * aid debugging, as well as to support extensions. Its use in any
957       * other context is discouraged.
958       *
959 <     * @return the result, or null if not completed.
959 >     * @return the result, or null if not completed
960       */
961      public abstract V getRawResult();
962  
# Line 920 | Line 977 | public abstract class ForkJoinTask<V> im
977       * asynchronous actions that require explicit invocations of
978       * {@code complete} to become joinable. It may throw exceptions
979       * to indicate abnormal exit.
980 +     *
981       * @return true if completed normally
982       * @throws Error or RuntimeException if encountered during computation
983       */
# Line 932 | Line 990 | public abstract class ForkJoinTask<V> im
990       * be polled or executed next.  This method is designed primarily
991       * to support extensions, and is unlikely to be useful otherwise.
992       * This method may be invoked only from within ForkJoinTask
993 <     * computations. Attempts to invoke in other contexts result in
994 <     * exceptions or errors possibly including ClassCastException.
993 >     * computations (as may be determined using method {@link
994 >     * #inForkJoinPool}). Attempts to invoke in other contexts result
995 >     * in exceptions or errors, possibly including ClassCastException.
996       *
997       * @return the next task, or null if none are available
998       */
999      protected static ForkJoinTask<?> peekNextLocalTask() {
1000 <        return ((ForkJoinWorkerThread)(Thread.currentThread())).peekTask();
1000 >        return ((ForkJoinWorkerThread) Thread.currentThread())
1001 >            .peekTask();
1002      }
1003  
1004      /**
# Line 946 | Line 1006 | public abstract class ForkJoinTask<V> im
1006       * queued by the current thread but not yet executed.  This method
1007       * is designed primarily to support extensions, and is unlikely to
1008       * be useful otherwise.  This method may be invoked only from
1009 <     * within ForkJoinTask computations. Attempts to invoke in other
1010 <     * contexts result in exceptions or errors possibly including
1009 >     * within ForkJoinTask computations (as may be determined using
1010 >     * method {@link #inForkJoinPool}). Attempts to invoke in other
1011 >     * contexts result in exceptions or errors, possibly including
1012       * ClassCastException.
1013       *
1014       * @return the next task, or null if none are available
1015       */
1016      protected static ForkJoinTask<?> pollNextLocalTask() {
1017 <        return ((ForkJoinWorkerThread)(Thread.currentThread())).pollLocalTask();
1017 >        return ((ForkJoinWorkerThread) Thread.currentThread())
1018 >            .pollLocalTask();
1019      }
1020  
1021      /**
# Line 965 | Line 1027 | public abstract class ForkJoinTask<V> im
1027       * of the pool this task is operating in.  This method is designed
1028       * primarily to support extensions, and is unlikely to be useful
1029       * otherwise.  This method may be invoked only from within
1030 <     * ForkJoinTask computations. Attempts to invoke in other contexts
1031 <     * result in exceptions or errors possibly including
1030 >     * ForkJoinTask computations (as may be determined using method
1031 >     * {@link #inForkJoinPool}). Attempts to invoke in other contexts
1032 >     * result in exceptions or errors, possibly including
1033       * ClassCastException.
1034       *
1035       * @return a task, or null if none are available
1036       */
1037      protected static ForkJoinTask<?> pollTask() {
1038 <        return ((ForkJoinWorkerThread)(Thread.currentThread())).
1039 <            pollTask();
1038 >        return ((ForkJoinWorkerThread) Thread.currentThread())
1039 >            .pollTask();
1040 >    }
1041 >
1042 >    // adaptors
1043 >
1044 >    /**
1045 >     * Returns a new ForkJoinTask that performs the {@code run}
1046 >     * method of the given Runnable as its action, and returns a null
1047 >     * result upon {@code join}.
1048 >     *
1049 >     * @param runnable the runnable action
1050 >     * @return the task
1051 >     */
1052 >    public static ForkJoinTask<Void> adapt(Runnable runnable) {
1053 >        return new ForkJoinPool.AdaptedRunnable<Void>(runnable, null);
1054 >    }
1055 >
1056 >    /**
1057 >     * Returns a new ForkJoinTask that performs the {@code run}
1058 >     * method of the given Runnable as its action, and returns the
1059 >     * given result upon {@code join}.
1060 >     *
1061 >     * @param runnable the runnable action
1062 >     * @param result the result upon completion
1063 >     * @return the task
1064 >     */
1065 >    public static <T> ForkJoinTask<T> adapt(Runnable runnable, T result) {
1066 >        return new ForkJoinPool.AdaptedRunnable<T>(runnable, result);
1067 >    }
1068 >
1069 >    /**
1070 >     * Returns a new ForkJoinTask that performs the {@code call}
1071 >     * method of the given Callable as its action, and returns its
1072 >     * result upon {@code join}, translating any checked
1073 >     * exceptions encountered into {@code RuntimeException}.
1074 >     *
1075 >     * @param callable the callable action
1076 >     * @return the task
1077 >     */
1078 >    public static <T> ForkJoinTask<T> adapt(Callable<T> callable) {
1079 >        return new ForkJoinPool.AdaptedCallable<T>(callable);
1080      }
1081  
1082      // Serialization support
# Line 984 | Line 1087 | public abstract class ForkJoinTask<V> im
1087       * Save the state to a stream.
1088       *
1089       * @serialData the current run status and the exception thrown
1090 <     * during execution, or null if none.
1090 >     * during execution, or null if none
1091       * @param s the stream
1092       */
1093      private void writeObject(java.io.ObjectOutputStream s)
# Line 995 | Line 1098 | public abstract class ForkJoinTask<V> im
1098  
1099      /**
1100       * Reconstitute the instance from a stream.
1101 +     *
1102       * @param s the stream
1103       */
1104      private void readObject(java.io.ObjectInputStream s)
# Line 1004 | Line 1108 | public abstract class ForkJoinTask<V> im
1108          status |= EXTERNAL_SIGNAL; // conservatively set external signal
1109          Object ex = s.readObject();
1110          if (ex != null)
1111 <            setDoneExceptionally((Throwable)ex);
1111 >            setDoneExceptionally((Throwable) ex);
1112      }
1113  
1114 <    // Temporary Unsafe mechanics for preliminary release
1115 <    private static Unsafe getUnsafe() throws Throwable {
1114 >    // Unsafe mechanics for jsr166y 3rd party package.
1115 >    private static sun.misc.Unsafe getUnsafe() {
1116          try {
1117 <            return Unsafe.getUnsafe();
1117 >            return sun.misc.Unsafe.getUnsafe();
1118          } catch (SecurityException se) {
1119              try {
1120                  return java.security.AccessController.doPrivileged
1121 <                    (new java.security.PrivilegedExceptionAction<Unsafe>() {
1122 <                        public Unsafe run() throws Exception {
1123 <                            return getUnsafePrivileged();
1121 >                    (new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() {
1122 >                        public sun.misc.Unsafe run() throws Exception {
1123 >                            return getUnsafeByReflection();
1124                          }});
1125              } catch (java.security.PrivilegedActionException e) {
1126 <                throw e.getCause();
1126 >                throw new RuntimeException("Could not initialize intrinsics",
1127 >                                           e.getCause());
1128              }
1129          }
1130      }
1131  
1132 <    private static Unsafe getUnsafePrivileged()
1132 >    private static sun.misc.Unsafe getUnsafeByReflection()
1133              throws NoSuchFieldException, IllegalAccessException {
1134 <        Field f = Unsafe.class.getDeclaredField("theUnsafe");
1134 >        java.lang.reflect.Field f =
1135 >            sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
1136          f.setAccessible(true);
1137 <        return (Unsafe) f.get(null);
1137 >        return (sun.misc.Unsafe) f.get(null);
1138      }
1139  
1140 <    private static long fieldOffset(String fieldName)
1035 <            throws NoSuchFieldException {
1036 <        return _unsafe.objectFieldOffset
1037 <            (ForkJoinTask.class.getDeclaredField(fieldName));
1038 <    }
1039 <
1040 <    static final Unsafe _unsafe;
1041 <    static final long statusOffset;
1042 <
1043 <    static {
1140 >    private static long fieldOffset(String fieldName, Class<?> klazz) {
1141          try {
1142 <            _unsafe = getUnsafe();
1143 <            statusOffset = fieldOffset("status");
1144 <        } catch (Throwable e) {
1145 <            throw new RuntimeException("Could not initialize intrinsics", e);
1142 >            return UNSAFE.objectFieldOffset(klazz.getDeclaredField(fieldName));
1143 >        } catch (NoSuchFieldException e) {
1144 >            // Convert Exception to Error
1145 >            NoSuchFieldError error = new NoSuchFieldError(fieldName);
1146 >            error.initCause(e);
1147 >            throw error;
1148          }
1149      }
1150  
1151 +    private static final sun.misc.Unsafe UNSAFE = getUnsafe();
1152 +    private static final long statusOffset =
1153 +        fieldOffset("status", ForkJoinTask.class);
1154 +
1155   }

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