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package jsr166y; |
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import java.util.concurrent.*; |
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import java.io.Serializable; |
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import java.util.Collection; |
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import java.util.Collections; |
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* start other subtasks. As indicated by the name of this class, |
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* many programs using {@code ForkJoinTask} employ only methods |
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* {@link #fork} and {@link #join}, or derivatives such as {@link |
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* #invokeAll}. However, this class also provides a number of other |
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* methods that can come into play in advanced usages, as well as |
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* extension mechanics that allow support of new forms of fork/join |
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* processing. |
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* #invokeAll(ForkJoinTask...) invokeAll}. However, this class also |
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* provides a number of other methods that can come into play in |
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* advanced usages, as well as extension mechanics that allow |
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* support of new forms of fork/join processing. |
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* |
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* <p>A {@code ForkJoinTask} is a lightweight form of {@link Future}. |
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* The efficiency of {@code ForkJoinTask}s stems from a set of |
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/** |
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* Records exception and sets exceptional completion. |
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* |
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* |
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* @return status on exit |
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*/ |
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private void setExceptionalCompletion(Throwable rex) { |
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int s; // the odd construction reduces lock bias effects |
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while ((s = status) >= 0) { |
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try { |
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synchronized(this) { |
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synchronized (this) { |
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if (UNSAFE.compareAndSwapInt(this, statusOffset, s,SIGNAL)) |
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wait(); |
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} |
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int s; |
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if ((s = status) >= 0) { |
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try { |
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synchronized(this) { |
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synchronized (this) { |
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if (UNSAFE.compareAndSwapInt(this, statusOffset, s,SIGNAL)) |
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wait(millis, 0); |
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} |
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private void externalAwaitDone() { |
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int s; |
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while ((s = status) >= 0) { |
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synchronized(this) { |
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synchronized (this) { |
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if (UNSAFE.compareAndSwapInt(this, statusOffset, s, SIGNAL)){ |
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boolean interrupted = false; |
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while (status >= 0) { |
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setCompletion(NORMAL); |
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} |
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/** |
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* Waits if necessary for the computation to complete, and then |
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* retrieves its result. |
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* |
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* @return the computed result |
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* @throws CancellationException if the computation was cancelled |
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* @throws ExecutionException if the computation threw an |
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* exception |
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* @throws InterruptedException if the current thread is not a |
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* member of a ForkJoinPool and was interrupted while waiting |
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*/ |
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public final V get() throws InterruptedException, ExecutionException { |
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quietlyJoin(); |
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if (Thread.interrupted()) |
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throw new InterruptedException(); |
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int s = status; |
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int s; |
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if (Thread.currentThread() instanceof ForkJoinWorkerThread) { |
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quietlyJoin(); |
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s = status; |
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} |
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else { |
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while ((s = status) >= 0) { |
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synchronized (this) { // interruptible form of awaitDone |
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if (UNSAFE.compareAndSwapInt(this, statusOffset, |
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s, SIGNAL)) { |
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while (status >= 0) |
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wait(); |
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} |
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} |
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} |
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} |
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if (s < NORMAL) { |
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Throwable ex; |
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if (s == CANCELLED) |
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return getRawResult(); |
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} |
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/** |
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* Waits if necessary for at most the given time for the computation |
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* to complete, and then retrieves its result, if available. |
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* |
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* @param timeout the maximum time to wait |
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* @param unit the time unit of the timeout argument |
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* @return the computed result |
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* @throws CancellationException if the computation was cancelled |
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* @throws ExecutionException if the computation threw an |
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* exception |
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* @throws InterruptedException if the current thread is not a |
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* member of a ForkJoinPool and was interrupted while waiting |
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* @throws TimeoutException if the wait timed out |
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*/ |
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public final V get(long timeout, TimeUnit unit) |
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throws InterruptedException, ExecutionException, TimeoutException { |
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Thread t = Thread.currentThread(); |
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long ms = nt / 1000000; |
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int ns = (int) (nt % 1000000); |
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try { |
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synchronized(this) { |
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synchronized (this) { |
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if (status >= 0) |
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wait(ms, ns); |
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} |