1357 lines
52 KiB
Java
1357 lines
52 KiB
Java
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* This file is available under and governed by the GNU General Public
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* License version 2 only, as published by the Free Software Foundation.
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* However, the following notice accompanied the original version of this
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* file:
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*
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* Written by Doug Lea with assistance from members of JCP JSR-166
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* Expert Group and released to the public domain, as explained at
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* http://creativecommons.org/publicdomain/zero/1.0/
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*/
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package java.util.concurrent;
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import static java.util.concurrent.TimeUnit.MILLISECONDS;
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import static java.util.concurrent.TimeUnit.NANOSECONDS;
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import java.util.AbstractQueue;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.Iterator;
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import java.util.List;
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import java.util.NoSuchElementException;
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import java.util.Objects;
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import java.util.concurrent.atomic.AtomicLong;
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import java.util.concurrent.locks.Condition;
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import java.util.concurrent.locks.ReentrantLock;
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// BEGIN android-note
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// omit class-level docs on setRemoveOnCancelPolicy()
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// END android-note
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/**
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* A {@link ThreadPoolExecutor} that can additionally schedule
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* commands to run after a given delay, or to execute periodically.
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* This class is preferable to {@link java.util.Timer} when multiple
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* worker threads are needed, or when the additional flexibility or
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* capabilities of {@link ThreadPoolExecutor} (which this class
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* extends) are required.
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*
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* <p>Delayed tasks execute no sooner than they are enabled, but
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* without any real-time guarantees about when, after they are
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* enabled, they will commence. Tasks scheduled for exactly the same
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* execution time are enabled in first-in-first-out (FIFO) order of
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* submission.
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*
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* <p>When a submitted task is cancelled before it is run, execution
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* is suppressed. By default, such a cancelled task is not
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* automatically removed from the work queue until its delay elapses.
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* While this enables further inspection and monitoring, it may also
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* cause unbounded retention of cancelled tasks.
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*
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* <p>Successive executions of a periodic task scheduled via
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* {@link #scheduleAtFixedRate scheduleAtFixedRate} or
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* {@link #scheduleWithFixedDelay scheduleWithFixedDelay}
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* do not overlap. While different executions may be performed by
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* different threads, the effects of prior executions
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* <a href="package-summary.html#MemoryVisibility"><i>happen-before</i></a>
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* those of subsequent ones.
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*
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* <p>While this class inherits from {@link ThreadPoolExecutor}, a few
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* of the inherited tuning methods are not useful for it. In
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* particular, because it acts as a fixed-sized pool using
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* {@code corePoolSize} threads and an unbounded queue, adjustments
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* to {@code maximumPoolSize} have no useful effect. Additionally, it
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* is almost never a good idea to set {@code corePoolSize} to zero or
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* use {@code allowCoreThreadTimeOut} because this may leave the pool
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* without threads to handle tasks once they become eligible to run.
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*
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* <p>As with {@code ThreadPoolExecutor}, if not otherwise specified,
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* this class uses {@link Executors#defaultThreadFactory} as the
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* default thread factory, and {@link ThreadPoolExecutor.AbortPolicy}
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* as the default rejected execution handler.
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*
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* <p><b>Extension notes:</b> This class overrides the
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* {@link ThreadPoolExecutor#execute(Runnable) execute} and
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* {@link AbstractExecutorService#submit(Runnable) submit}
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* methods to generate internal {@link ScheduledFuture} objects to
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* control per-task delays and scheduling. To preserve
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* functionality, any further overrides of these methods in
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* subclasses must invoke superclass versions, which effectively
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* disables additional task customization. However, this class
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* provides alternative protected extension method
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* {@code decorateTask} (one version each for {@code Runnable} and
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* {@code Callable}) that can be used to customize the concrete task
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* types used to execute commands entered via {@code execute},
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* {@code submit}, {@code schedule}, {@code scheduleAtFixedRate},
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* and {@code scheduleWithFixedDelay}. By default, a
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* {@code ScheduledThreadPoolExecutor} uses a task type extending
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* {@link FutureTask}. However, this may be modified or replaced using
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* subclasses of the form:
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*
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* <pre> {@code
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* public class CustomScheduledExecutor extends ScheduledThreadPoolExecutor {
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*
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* static class CustomTask<V> implements RunnableScheduledFuture<V> { ... }
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*
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* protected <V> RunnableScheduledFuture<V> decorateTask(
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* Runnable r, RunnableScheduledFuture<V> task) {
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* return new CustomTask<V>(r, task);
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* }
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*
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* protected <V> RunnableScheduledFuture<V> decorateTask(
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* Callable<V> c, RunnableScheduledFuture<V> task) {
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* return new CustomTask<V>(c, task);
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* }
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* // ... add constructors, etc.
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* }}</pre>
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*
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* @since 1.5
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* @author Doug Lea
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*/
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public class ScheduledThreadPoolExecutor
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extends ThreadPoolExecutor
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implements ScheduledExecutorService {
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/*
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* This class specializes ThreadPoolExecutor implementation by
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*
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* 1. Using a custom task type ScheduledFutureTask, even for tasks
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* that don't require scheduling because they are submitted
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* using ExecutorService rather than ScheduledExecutorService
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* methods, which are treated as tasks with a delay of zero.
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*
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* 2. Using a custom queue (DelayedWorkQueue), a variant of
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* unbounded DelayQueue. The lack of capacity constraint and
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* the fact that corePoolSize and maximumPoolSize are
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* effectively identical simplifies some execution mechanics
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* (see delayedExecute) compared to ThreadPoolExecutor.
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*
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* 3. Supporting optional run-after-shutdown parameters, which
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* leads to overrides of shutdown methods to remove and cancel
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* tasks that should NOT be run after shutdown, as well as
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* different recheck logic when task (re)submission overlaps
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* with a shutdown.
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*
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* 4. Task decoration methods to allow interception and
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* instrumentation, which are needed because subclasses cannot
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* otherwise override submit methods to get this effect. These
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* don't have any impact on pool control logic though.
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*/
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/**
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* False if should cancel/suppress periodic tasks on shutdown.
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*/
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private volatile boolean continueExistingPeriodicTasksAfterShutdown;
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// Android-changed: Preserving behaviour on expired tasks (b/202927404)
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/**
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* False if should cancel non-periodic tasks on shutdown.
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*/
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private volatile boolean executeExistingDelayedTasksAfterShutdown = true;
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/**
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* True if ScheduledFutureTask.cancel should remove from queue.
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*/
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volatile boolean removeOnCancel;
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/**
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* Sequence number to break scheduling ties, and in turn to
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* guarantee FIFO order among tied entries.
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*/
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private static final AtomicLong sequencer = new AtomicLong();
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private class ScheduledFutureTask<V>
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extends FutureTask<V> implements RunnableScheduledFuture<V> {
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/** Sequence number to break ties FIFO */
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private final long sequenceNumber;
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/** The nanoTime-based time when the task is enabled to execute. */
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private volatile long time;
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/**
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* Period for repeating tasks, in nanoseconds.
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* A positive value indicates fixed-rate execution.
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* A negative value indicates fixed-delay execution.
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* A value of 0 indicates a non-repeating (one-shot) task.
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*/
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private final long period;
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/** The actual task to be re-enqueued by reExecutePeriodic */
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RunnableScheduledFuture<V> outerTask = this;
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/**
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* Index into delay queue, to support faster cancellation.
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*/
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int heapIndex;
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/**
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* Creates a one-shot action with given nanoTime-based trigger time.
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*/
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ScheduledFutureTask(Runnable r, V result, long triggerTime,
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long sequenceNumber) {
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super(r, result);
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this.time = triggerTime;
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this.period = 0;
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this.sequenceNumber = sequenceNumber;
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}
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/**
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* Creates a periodic action with given nanoTime-based initial
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* trigger time and period.
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*/
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ScheduledFutureTask(Runnable r, V result, long triggerTime,
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long period, long sequenceNumber) {
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super(r, result);
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this.time = triggerTime;
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this.period = period;
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this.sequenceNumber = sequenceNumber;
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}
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/**
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* Creates a one-shot action with given nanoTime-based trigger time.
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*/
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ScheduledFutureTask(Callable<V> callable, long triggerTime,
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long sequenceNumber) {
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super(callable);
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this.time = triggerTime;
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this.period = 0;
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this.sequenceNumber = sequenceNumber;
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}
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public long getDelay(TimeUnit unit) {
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return unit.convert(time - System.nanoTime(), NANOSECONDS);
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}
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public int compareTo(Delayed other) {
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if (other == this) // compare zero if same object
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return 0;
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if (other instanceof ScheduledFutureTask) {
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ScheduledFutureTask<?> x = (ScheduledFutureTask<?>)other;
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long diff = time - x.time;
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if (diff < 0)
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return -1;
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else if (diff > 0)
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return 1;
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else if (sequenceNumber < x.sequenceNumber)
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return -1;
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else
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return 1;
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}
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long diff = getDelay(NANOSECONDS) - other.getDelay(NANOSECONDS);
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return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
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}
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/**
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* Returns {@code true} if this is a periodic (not a one-shot) action.
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*
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* @return {@code true} if periodic
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*/
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public boolean isPeriodic() {
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return period != 0;
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}
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/**
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* Sets the next time to run for a periodic task.
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*/
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private void setNextRunTime() {
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long p = period;
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if (p > 0)
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time += p;
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else
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time = triggerTime(-p);
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}
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public boolean cancel(boolean mayInterruptIfRunning) {
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// The racy read of heapIndex below is benign:
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// if heapIndex < 0, then OOTA guarantees that we have surely
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// been removed; else we recheck under lock in remove()
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boolean cancelled = super.cancel(mayInterruptIfRunning);
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if (cancelled && removeOnCancel && heapIndex >= 0)
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remove(this);
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return cancelled;
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}
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/**
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* Overrides FutureTask version so as to reset/requeue if periodic.
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*/
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public void run() {
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if (!canRunInCurrentRunState(this))
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cancel(false);
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else if (!isPeriodic())
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super.run();
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else if (super.runAndReset()) {
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setNextRunTime();
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reExecutePeriodic(outerTask);
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}
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}
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}
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/**
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* Returns true if can run a task given current run state and
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* run-after-shutdown parameters.
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*/
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boolean canRunInCurrentRunState(RunnableScheduledFuture<?> task) {
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if (!isShutdown())
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return true;
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if (isStopped())
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return false;
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return task.isPeriodic()
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? continueExistingPeriodicTasksAfterShutdown
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: (executeExistingDelayedTasksAfterShutdown
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// Android-changed: Preserving behaviour on expired tasks (b/202927404)
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// || task.getDelay(NANOSECONDS) <= 0);
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);
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}
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/**
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* Main execution method for delayed or periodic tasks. If pool
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* is shut down, rejects the task. Otherwise adds task to queue
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* and starts a thread, if necessary, to run it. (We cannot
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* prestart the thread to run the task because the task (probably)
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* shouldn't be run yet.) If the pool is shut down while the task
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* is being added, cancel and remove it if required by state and
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* run-after-shutdown parameters.
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*
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* @param task the task
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*/
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private void delayedExecute(RunnableScheduledFuture<?> task) {
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if (isShutdown())
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reject(task);
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else {
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super.getQueue().add(task);
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if (!canRunInCurrentRunState(task) && remove(task))
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task.cancel(false);
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else
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ensurePrestart();
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}
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}
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/**
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* Requeues a periodic task unless current run state precludes it.
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* Same idea as delayedExecute except drops task rather than rejecting.
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*
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* @param task the task
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*/
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void reExecutePeriodic(RunnableScheduledFuture<?> task) {
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if (canRunInCurrentRunState(task)) {
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super.getQueue().add(task);
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if (canRunInCurrentRunState(task) || !remove(task)) {
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ensurePrestart();
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return;
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}
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}
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task.cancel(false);
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}
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/**
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* Cancels and clears the queue of all tasks that should not be run
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* due to shutdown policy. Invoked within super.shutdown.
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*/
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@Override void onShutdown() {
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BlockingQueue<Runnable> q = super.getQueue();
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boolean keepDelayed =
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getExecuteExistingDelayedTasksAfterShutdownPolicy();
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boolean keepPeriodic =
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getContinueExistingPeriodicTasksAfterShutdownPolicy();
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// Traverse snapshot to avoid iterator exceptions
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// TODO: implement and use efficient removeIf
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// super.getQueue().removeIf(...);
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for (Object e : q.toArray()) {
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if (e instanceof RunnableScheduledFuture) {
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RunnableScheduledFuture<?> t = (RunnableScheduledFuture<?>)e;
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if ((t.isPeriodic()
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? !keepPeriodic
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// Android-changed: Preserving behaviour on expired tasks (b/202927404)
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// : (!keepDelayed && t.getDelay(NANOSECONDS) > 0))
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: !keepDelayed)
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|| t.isCancelled()) { // also remove if already cancelled
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if (q.remove(t))
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t.cancel(false);
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}
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}
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}
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tryTerminate();
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}
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/**
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* Modifies or replaces the task used to execute a runnable.
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* This method can be used to override the concrete
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* class used for managing internal tasks.
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* The default implementation simply returns the given task.
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*
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* @param runnable the submitted Runnable
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* @param task the task created to execute the runnable
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* @param <V> the type of the task's result
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* @return a task that can execute the runnable
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* @since 1.6
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*/
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protected <V> RunnableScheduledFuture<V> decorateTask(
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Runnable runnable, RunnableScheduledFuture<V> task) {
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return task;
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}
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/**
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* Modifies or replaces the task used to execute a callable.
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* This method can be used to override the concrete
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* class used for managing internal tasks.
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* The default implementation simply returns the given task.
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*
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* @param callable the submitted Callable
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* @param task the task created to execute the callable
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* @param <V> the type of the task's result
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* @return a task that can execute the callable
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* @since 1.6
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*/
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protected <V> RunnableScheduledFuture<V> decorateTask(
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Callable<V> callable, RunnableScheduledFuture<V> task) {
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return task;
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}
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/**
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* The default keep-alive time for pool threads.
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*
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* Normally, this value is unused because all pool threads will be
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* core threads, but if a user creates a pool with a corePoolSize
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* of zero (against our advice), we keep a thread alive as long as
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* there are queued tasks. If the keep alive time is zero (the
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* historic value), we end up hot-spinning in getTask, wasting a
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* CPU. But on the other hand, if we set the value too high, and
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* users create a one-shot pool which they don't cleanly shutdown,
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* the pool's non-daemon threads will prevent JVM termination. A
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* small but non-zero value (relative to a JVM's lifetime) seems
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* best.
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*/
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private static final long DEFAULT_KEEPALIVE_MILLIS = 10L;
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|
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/**
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* Creates a new {@code ScheduledThreadPoolExecutor} with the
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* given core pool size.
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*
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* @param corePoolSize the number of threads to keep in the pool, even
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* if they are idle, unless {@code allowCoreThreadTimeOut} is set
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* @throws IllegalArgumentException if {@code corePoolSize < 0}
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*/
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public ScheduledThreadPoolExecutor(int corePoolSize) {
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super(corePoolSize, Integer.MAX_VALUE,
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DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS,
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new DelayedWorkQueue());
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}
|
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|
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/**
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|
* Creates a new {@code ScheduledThreadPoolExecutor} with the
|
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* given initial parameters.
|
|
*
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|
* @param corePoolSize the number of threads to keep in the pool, even
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* if they are idle, unless {@code allowCoreThreadTimeOut} is set
|
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* @param threadFactory the factory to use when the executor
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* creates a new thread
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* @throws IllegalArgumentException if {@code corePoolSize < 0}
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* @throws NullPointerException if {@code threadFactory} is null
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*/
|
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public ScheduledThreadPoolExecutor(int corePoolSize,
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ThreadFactory threadFactory) {
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super(corePoolSize, Integer.MAX_VALUE,
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DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS,
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new DelayedWorkQueue(), threadFactory);
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}
|
|
|
|
/**
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|
* Creates a new {@code ScheduledThreadPoolExecutor} with the
|
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* given initial parameters.
|
|
*
|
|
* @param corePoolSize the number of threads to keep in the pool, even
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set
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|
* @param handler the handler to use when execution is blocked
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* because the thread bounds and queue capacities are reached
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* @throws IllegalArgumentException if {@code corePoolSize < 0}
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* @throws NullPointerException if {@code handler} is null
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*/
|
|
public ScheduledThreadPoolExecutor(int corePoolSize,
|
|
RejectedExecutionHandler handler) {
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|
super(corePoolSize, Integer.MAX_VALUE,
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DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS,
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|
new DelayedWorkQueue(), handler);
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}
|
|
|
|
/**
|
|
* Creates a new {@code ScheduledThreadPoolExecutor} with the
|
|
* given initial parameters.
|
|
*
|
|
* @param corePoolSize the number of threads to keep in the pool, even
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set
|
|
* @param threadFactory the factory to use when the executor
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|
* creates a new thread
|
|
* @param handler the handler to use when execution is blocked
|
|
* because the thread bounds and queue capacities are reached
|
|
* @throws IllegalArgumentException if {@code corePoolSize < 0}
|
|
* @throws NullPointerException if {@code threadFactory} or
|
|
* {@code handler} is null
|
|
*/
|
|
public ScheduledThreadPoolExecutor(int corePoolSize,
|
|
ThreadFactory threadFactory,
|
|
RejectedExecutionHandler handler) {
|
|
super(corePoolSize, Integer.MAX_VALUE,
|
|
DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS,
|
|
new DelayedWorkQueue(), threadFactory, handler);
|
|
}
|
|
|
|
/**
|
|
* Returns the nanoTime-based trigger time of a delayed action.
|
|
*/
|
|
private long triggerTime(long delay, TimeUnit unit) {
|
|
return triggerTime(unit.toNanos((delay < 0) ? 0 : delay));
|
|
}
|
|
|
|
/**
|
|
* Returns the nanoTime-based trigger time of a delayed action.
|
|
*/
|
|
long triggerTime(long delay) {
|
|
return System.nanoTime() +
|
|
((delay < (Long.MAX_VALUE >> 1)) ? delay : overflowFree(delay));
|
|
}
|
|
|
|
/**
|
|
* Constrains the values of all delays in the queue to be within
|
|
* Long.MAX_VALUE of each other, to avoid overflow in compareTo.
|
|
* This may occur if a task is eligible to be dequeued, but has
|
|
* not yet been, while some other task is added with a delay of
|
|
* Long.MAX_VALUE.
|
|
*/
|
|
private long overflowFree(long delay) {
|
|
Delayed head = (Delayed) super.getQueue().peek();
|
|
if (head != null) {
|
|
long headDelay = head.getDelay(NANOSECONDS);
|
|
if (headDelay < 0 && (delay - headDelay < 0))
|
|
delay = Long.MAX_VALUE + headDelay;
|
|
}
|
|
return delay;
|
|
}
|
|
|
|
/**
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public ScheduledFuture<?> schedule(Runnable command,
|
|
long delay,
|
|
TimeUnit unit) {
|
|
if (command == null || unit == null)
|
|
throw new NullPointerException();
|
|
RunnableScheduledFuture<Void> t = decorateTask(command,
|
|
new ScheduledFutureTask<Void>(command, null,
|
|
triggerTime(delay, unit),
|
|
sequencer.getAndIncrement()));
|
|
delayedExecute(t);
|
|
return t;
|
|
}
|
|
|
|
/**
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public <V> ScheduledFuture<V> schedule(Callable<V> callable,
|
|
long delay,
|
|
TimeUnit unit) {
|
|
if (callable == null || unit == null)
|
|
throw new NullPointerException();
|
|
RunnableScheduledFuture<V> t = decorateTask(callable,
|
|
new ScheduledFutureTask<V>(callable,
|
|
triggerTime(delay, unit),
|
|
sequencer.getAndIncrement()));
|
|
delayedExecute(t);
|
|
return t;
|
|
}
|
|
|
|
/**
|
|
* Submits a periodic action that becomes enabled first after the
|
|
* given initial delay, and subsequently with the given period;
|
|
* that is, executions will commence after
|
|
* {@code initialDelay}, then {@code initialDelay + period}, then
|
|
* {@code initialDelay + 2 * period}, and so on.
|
|
*
|
|
* <p>The sequence of task executions continues indefinitely until
|
|
* one of the following exceptional completions occur:
|
|
* <ul>
|
|
* <li>The task is {@linkplain Future#cancel explicitly cancelled}
|
|
* via the returned future.
|
|
* <li>Method {@link #shutdown} is called and the {@linkplain
|
|
* #getContinueExistingPeriodicTasksAfterShutdownPolicy policy on
|
|
* whether to continue after shutdown} is not set true, or method
|
|
* {@link #shutdownNow} is called; also resulting in task
|
|
* cancellation.
|
|
* <li>An execution of the task throws an exception. In this case
|
|
* calling {@link Future#get() get} on the returned future will throw
|
|
* {@link ExecutionException}, holding the exception as its cause.
|
|
* </ul>
|
|
* Subsequent executions are suppressed. Subsequent calls to
|
|
* {@link Future#isDone isDone()} on the returned future will
|
|
* return {@code true}.
|
|
*
|
|
* <p>If any execution of this task takes longer than its period, then
|
|
* subsequent executions may start late, but will not concurrently
|
|
* execute.
|
|
*
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
* @throws IllegalArgumentException {@inheritDoc}
|
|
*/
|
|
public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,
|
|
long initialDelay,
|
|
long period,
|
|
TimeUnit unit) {
|
|
if (command == null || unit == null)
|
|
throw new NullPointerException();
|
|
if (period <= 0L)
|
|
throw new IllegalArgumentException();
|
|
ScheduledFutureTask<Void> sft =
|
|
new ScheduledFutureTask<Void>(command,
|
|
null,
|
|
triggerTime(initialDelay, unit),
|
|
unit.toNanos(period),
|
|
sequencer.getAndIncrement());
|
|
RunnableScheduledFuture<Void> t = decorateTask(command, sft);
|
|
sft.outerTask = t;
|
|
delayedExecute(t);
|
|
return t;
|
|
}
|
|
|
|
/**
|
|
* Submits a periodic action that becomes enabled first after the
|
|
* given initial delay, and subsequently with the given delay
|
|
* between the termination of one execution and the commencement of
|
|
* the next.
|
|
*
|
|
* <p>The sequence of task executions continues indefinitely until
|
|
* one of the following exceptional completions occur:
|
|
* <ul>
|
|
* <li>The task is {@linkplain Future#cancel explicitly cancelled}
|
|
* via the returned future.
|
|
* <li>Method {@link #shutdown} is called and the {@linkplain
|
|
* #getContinueExistingPeriodicTasksAfterShutdownPolicy policy on
|
|
* whether to continue after shutdown} is not set true, or method
|
|
* {@link #shutdownNow} is called; also resulting in task
|
|
* cancellation.
|
|
* <li>An execution of the task throws an exception. In this case
|
|
* calling {@link Future#get() get} on the returned future will throw
|
|
* {@link ExecutionException}, holding the exception as its cause.
|
|
* </ul>
|
|
* Subsequent executions are suppressed. Subsequent calls to
|
|
* {@link Future#isDone isDone()} on the returned future will
|
|
* return {@code true}.
|
|
*
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
* @throws IllegalArgumentException {@inheritDoc}
|
|
*/
|
|
public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command,
|
|
long initialDelay,
|
|
long delay,
|
|
TimeUnit unit) {
|
|
if (command == null || unit == null)
|
|
throw new NullPointerException();
|
|
if (delay <= 0L)
|
|
throw new IllegalArgumentException();
|
|
ScheduledFutureTask<Void> sft =
|
|
new ScheduledFutureTask<Void>(command,
|
|
null,
|
|
triggerTime(initialDelay, unit),
|
|
-unit.toNanos(delay),
|
|
sequencer.getAndIncrement());
|
|
RunnableScheduledFuture<Void> t = decorateTask(command, sft);
|
|
sft.outerTask = t;
|
|
delayedExecute(t);
|
|
return t;
|
|
}
|
|
|
|
/**
|
|
* Executes {@code command} with zero required delay.
|
|
* This has effect equivalent to
|
|
* {@link #schedule(Runnable,long,TimeUnit) schedule(command, 0, anyUnit)}.
|
|
* Note that inspections of the queue and of the list returned by
|
|
* {@code shutdownNow} will access the zero-delayed
|
|
* {@link ScheduledFuture}, not the {@code command} itself.
|
|
*
|
|
* <p>A consequence of the use of {@code ScheduledFuture} objects is
|
|
* that {@link ThreadPoolExecutor#afterExecute afterExecute} is always
|
|
* called with a null second {@code Throwable} argument, even if the
|
|
* {@code command} terminated abruptly. Instead, the {@code Throwable}
|
|
* thrown by such a task can be obtained via {@link Future#get}.
|
|
*
|
|
* @throws RejectedExecutionException at discretion of
|
|
* {@code RejectedExecutionHandler}, if the task
|
|
* cannot be accepted for execution because the
|
|
* executor has been shut down
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public void execute(Runnable command) {
|
|
schedule(command, 0, NANOSECONDS);
|
|
}
|
|
|
|
// Override AbstractExecutorService methods
|
|
|
|
/**
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public Future<?> submit(Runnable task) {
|
|
return schedule(task, 0, NANOSECONDS);
|
|
}
|
|
|
|
/**
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public <T> Future<T> submit(Runnable task, T result) {
|
|
return schedule(Executors.callable(task, result), 0, NANOSECONDS);
|
|
}
|
|
|
|
/**
|
|
* @throws RejectedExecutionException {@inheritDoc}
|
|
* @throws NullPointerException {@inheritDoc}
|
|
*/
|
|
public <T> Future<T> submit(Callable<T> task) {
|
|
return schedule(task, 0, NANOSECONDS);
|
|
}
|
|
|
|
/**
|
|
* Sets the policy on whether to continue executing existing
|
|
* periodic tasks even when this executor has been {@code shutdown}.
|
|
* In this case, executions will continue until {@code shutdownNow}
|
|
* or the policy is set to {@code false} when already shutdown.
|
|
* This value is by default {@code false}.
|
|
*
|
|
* @param value if {@code true}, continue after shutdown, else don't
|
|
* @see #getContinueExistingPeriodicTasksAfterShutdownPolicy
|
|
*/
|
|
public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean value) {
|
|
continueExistingPeriodicTasksAfterShutdown = value;
|
|
if (!value && isShutdown())
|
|
onShutdown();
|
|
}
|
|
|
|
/**
|
|
* Gets the policy on whether to continue executing existing
|
|
* periodic tasks even when this executor has been {@code shutdown}.
|
|
* In this case, executions will continue until {@code shutdownNow}
|
|
* or the policy is set to {@code false} when already shutdown.
|
|
* This value is by default {@code false}.
|
|
*
|
|
* @return {@code true} if will continue after shutdown
|
|
* @see #setContinueExistingPeriodicTasksAfterShutdownPolicy
|
|
*/
|
|
public boolean getContinueExistingPeriodicTasksAfterShutdownPolicy() {
|
|
return continueExistingPeriodicTasksAfterShutdown;
|
|
}
|
|
|
|
/**
|
|
* Sets the policy on whether to execute existing delayed
|
|
* tasks even when this executor has been {@code shutdown}.
|
|
* In this case, these tasks will only terminate upon
|
|
* {@code shutdownNow}, or after setting the policy to
|
|
* {@code false} when already shutdown.
|
|
* This value is by default {@code true}.
|
|
*
|
|
* @param value if {@code true}, execute after shutdown, else don't
|
|
* @see #getExecuteExistingDelayedTasksAfterShutdownPolicy
|
|
*/
|
|
public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean value) {
|
|
executeExistingDelayedTasksAfterShutdown = value;
|
|
if (!value && isShutdown())
|
|
onShutdown();
|
|
}
|
|
|
|
/**
|
|
* Gets the policy on whether to execute existing delayed
|
|
* tasks even when this executor has been {@code shutdown}.
|
|
* In this case, these tasks will only terminate upon
|
|
* {@code shutdownNow}, or after setting the policy to
|
|
* {@code false} when already shutdown.
|
|
* This value is by default {@code true}.
|
|
*
|
|
* @return {@code true} if will execute after shutdown
|
|
* @see #setExecuteExistingDelayedTasksAfterShutdownPolicy
|
|
*/
|
|
public boolean getExecuteExistingDelayedTasksAfterShutdownPolicy() {
|
|
return executeExistingDelayedTasksAfterShutdown;
|
|
}
|
|
|
|
/**
|
|
* Sets the policy on whether cancelled tasks should be immediately
|
|
* removed from the work queue at time of cancellation. This value is
|
|
* by default {@code false}.
|
|
*
|
|
* @param value if {@code true}, remove on cancellation, else don't
|
|
* @see #getRemoveOnCancelPolicy
|
|
* @since 1.7
|
|
*/
|
|
public void setRemoveOnCancelPolicy(boolean value) {
|
|
removeOnCancel = value;
|
|
}
|
|
|
|
/**
|
|
* Gets the policy on whether cancelled tasks should be immediately
|
|
* removed from the work queue at time of cancellation. This value is
|
|
* by default {@code false}.
|
|
*
|
|
* @return {@code true} if cancelled tasks are immediately removed
|
|
* from the queue
|
|
* @see #setRemoveOnCancelPolicy
|
|
* @since 1.7
|
|
*/
|
|
public boolean getRemoveOnCancelPolicy() {
|
|
return removeOnCancel;
|
|
}
|
|
|
|
/**
|
|
* Initiates an orderly shutdown in which previously submitted
|
|
* tasks are executed, but no new tasks will be accepted.
|
|
* Invocation has no additional effect if already shut down.
|
|
*
|
|
* <p>This method does not wait for previously submitted tasks to
|
|
* complete execution. Use {@link #awaitTermination awaitTermination}
|
|
* to do that.
|
|
*
|
|
* <p>If the {@code ExecuteExistingDelayedTasksAfterShutdownPolicy}
|
|
* has been set {@code false}, existing delayed tasks whose delays
|
|
* have not yet elapsed are cancelled. And unless the {@code
|
|
* ContinueExistingPeriodicTasksAfterShutdownPolicy} has been set
|
|
* {@code true}, future executions of existing periodic tasks will
|
|
* be cancelled.
|
|
*/
|
|
// android-note: Removed "throws SecurityException" doc.
|
|
public void shutdown() {
|
|
super.shutdown();
|
|
}
|
|
|
|
/**
|
|
* Attempts to stop all actively executing tasks, halts the
|
|
* processing of waiting tasks, and returns a list of the tasks
|
|
* that were awaiting execution. These tasks are drained (removed)
|
|
* from the task queue upon return from this method.
|
|
*
|
|
* <p>This method does not wait for actively executing tasks to
|
|
* terminate. Use {@link #awaitTermination awaitTermination} to
|
|
* do that.
|
|
*
|
|
* <p>There are no guarantees beyond best-effort attempts to stop
|
|
* processing actively executing tasks. This implementation
|
|
* interrupts tasks via {@link Thread#interrupt}; any task that
|
|
* fails to respond to interrupts may never terminate.
|
|
*
|
|
* @return list of tasks that never commenced execution.
|
|
* Each element of this list is a {@link ScheduledFuture}.
|
|
* For tasks submitted via one of the {@code schedule}
|
|
* methods, the element will be identical to the returned
|
|
* {@code ScheduledFuture}. For tasks submitted using
|
|
* {@link #execute execute}, the element will be a
|
|
* zero-delay {@code ScheduledFuture}.
|
|
*/
|
|
// android-note: Removed "throws SecurityException" doc.
|
|
public List<Runnable> shutdownNow() {
|
|
return super.shutdownNow();
|
|
}
|
|
|
|
/**
|
|
* Returns the task queue used by this executor. Access to the
|
|
* task queue is intended primarily for debugging and monitoring.
|
|
* This queue may be in active use. Retrieving the task queue
|
|
* does not prevent queued tasks from executing.
|
|
*
|
|
* <p>Each element of this queue is a {@link ScheduledFuture}.
|
|
* For tasks submitted via one of the {@code schedule} methods, the
|
|
* element will be identical to the returned {@code ScheduledFuture}.
|
|
* For tasks submitted using {@link #execute execute}, the element
|
|
* will be a zero-delay {@code ScheduledFuture}.
|
|
*
|
|
* <p>Iteration over this queue is <em>not</em> guaranteed to traverse
|
|
* tasks in the order in which they will execute.
|
|
*
|
|
* @return the task queue
|
|
*/
|
|
public BlockingQueue<Runnable> getQueue() {
|
|
return super.getQueue();
|
|
}
|
|
|
|
/**
|
|
* Specialized delay queue. To mesh with TPE declarations, this
|
|
* class must be declared as a BlockingQueue<Runnable> even though
|
|
* it can only hold RunnableScheduledFutures.
|
|
*/
|
|
static class DelayedWorkQueue extends AbstractQueue<Runnable>
|
|
implements BlockingQueue<Runnable> {
|
|
|
|
/*
|
|
* A DelayedWorkQueue is based on a heap-based data structure
|
|
* like those in DelayQueue and PriorityQueue, except that
|
|
* every ScheduledFutureTask also records its index into the
|
|
* heap array. This eliminates the need to find a task upon
|
|
* cancellation, greatly speeding up removal (down from O(n)
|
|
* to O(log n)), and reducing garbage retention that would
|
|
* otherwise occur by waiting for the element to rise to top
|
|
* before clearing. But because the queue may also hold
|
|
* RunnableScheduledFutures that are not ScheduledFutureTasks,
|
|
* we are not guaranteed to have such indices available, in
|
|
* which case we fall back to linear search. (We expect that
|
|
* most tasks will not be decorated, and that the faster cases
|
|
* will be much more common.)
|
|
*
|
|
* All heap operations must record index changes -- mainly
|
|
* within siftUp and siftDown. Upon removal, a task's
|
|
* heapIndex is set to -1. Note that ScheduledFutureTasks can
|
|
* appear at most once in the queue (this need not be true for
|
|
* other kinds of tasks or work queues), so are uniquely
|
|
* identified by heapIndex.
|
|
*/
|
|
|
|
private static final int INITIAL_CAPACITY = 16;
|
|
private RunnableScheduledFuture<?>[] queue =
|
|
new RunnableScheduledFuture<?>[INITIAL_CAPACITY];
|
|
private final ReentrantLock lock = new ReentrantLock();
|
|
private int size;
|
|
|
|
/**
|
|
* Thread designated to wait for the task at the head of the
|
|
* queue. This variant of the Leader-Follower pattern
|
|
* (http://www.cs.wustl.edu/~schmidt/POSA/POSA2/) serves to
|
|
* minimize unnecessary timed waiting. When a thread becomes
|
|
* the leader, it waits only for the next delay to elapse, but
|
|
* other threads await indefinitely. The leader thread must
|
|
* signal some other thread before returning from take() or
|
|
* poll(...), unless some other thread becomes leader in the
|
|
* interim. Whenever the head of the queue is replaced with a
|
|
* task with an earlier expiration time, the leader field is
|
|
* invalidated by being reset to null, and some waiting
|
|
* thread, but not necessarily the current leader, is
|
|
* signalled. So waiting threads must be prepared to acquire
|
|
* and lose leadership while waiting.
|
|
*/
|
|
private Thread leader;
|
|
|
|
/**
|
|
* Condition signalled when a newer task becomes available at the
|
|
* head of the queue or a new thread may need to become leader.
|
|
*/
|
|
private final Condition available = lock.newCondition();
|
|
|
|
/**
|
|
* Sets f's heapIndex if it is a ScheduledFutureTask.
|
|
*/
|
|
private static void setIndex(RunnableScheduledFuture<?> f, int idx) {
|
|
if (f instanceof ScheduledFutureTask)
|
|
((ScheduledFutureTask)f).heapIndex = idx;
|
|
}
|
|
|
|
/**
|
|
* Sifts element added at bottom up to its heap-ordered spot.
|
|
* Call only when holding lock.
|
|
*/
|
|
private void siftUp(int k, RunnableScheduledFuture<?> key) {
|
|
while (k > 0) {
|
|
int parent = (k - 1) >>> 1;
|
|
RunnableScheduledFuture<?> e = queue[parent];
|
|
if (key.compareTo(e) >= 0)
|
|
break;
|
|
queue[k] = e;
|
|
setIndex(e, k);
|
|
k = parent;
|
|
}
|
|
queue[k] = key;
|
|
setIndex(key, k);
|
|
}
|
|
|
|
/**
|
|
* Sifts element added at top down to its heap-ordered spot.
|
|
* Call only when holding lock.
|
|
*/
|
|
private void siftDown(int k, RunnableScheduledFuture<?> key) {
|
|
int half = size >>> 1;
|
|
while (k < half) {
|
|
int child = (k << 1) + 1;
|
|
RunnableScheduledFuture<?> c = queue[child];
|
|
int right = child + 1;
|
|
if (right < size && c.compareTo(queue[right]) > 0)
|
|
c = queue[child = right];
|
|
if (key.compareTo(c) <= 0)
|
|
break;
|
|
queue[k] = c;
|
|
setIndex(c, k);
|
|
k = child;
|
|
}
|
|
queue[k] = key;
|
|
setIndex(key, k);
|
|
}
|
|
|
|
/**
|
|
* Resizes the heap array. Call only when holding lock.
|
|
*/
|
|
private void grow() {
|
|
int oldCapacity = queue.length;
|
|
int newCapacity = oldCapacity + (oldCapacity >> 1); // grow 50%
|
|
if (newCapacity < 0) // overflow
|
|
newCapacity = Integer.MAX_VALUE;
|
|
queue = Arrays.copyOf(queue, newCapacity);
|
|
}
|
|
|
|
/**
|
|
* Finds index of given object, or -1 if absent.
|
|
*/
|
|
private int indexOf(Object x) {
|
|
if (x != null) {
|
|
if (x instanceof ScheduledFutureTask) {
|
|
int i = ((ScheduledFutureTask) x).heapIndex;
|
|
// Sanity check; x could conceivably be a
|
|
// ScheduledFutureTask from some other pool.
|
|
if (i >= 0 && i < size && queue[i] == x)
|
|
return i;
|
|
} else {
|
|
for (int i = 0; i < size; i++)
|
|
if (x.equals(queue[i]))
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
public boolean contains(Object x) {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
return indexOf(x) != -1;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public boolean remove(Object x) {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
int i = indexOf(x);
|
|
if (i < 0)
|
|
return false;
|
|
|
|
setIndex(queue[i], -1);
|
|
int s = --size;
|
|
RunnableScheduledFuture<?> replacement = queue[s];
|
|
queue[s] = null;
|
|
if (s != i) {
|
|
siftDown(i, replacement);
|
|
if (queue[i] == replacement)
|
|
siftUp(i, replacement);
|
|
}
|
|
return true;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public int size() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
return size;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public boolean isEmpty() {
|
|
return size() == 0;
|
|
}
|
|
|
|
public int remainingCapacity() {
|
|
return Integer.MAX_VALUE;
|
|
}
|
|
|
|
public RunnableScheduledFuture<?> peek() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
return queue[0];
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public boolean offer(Runnable x) {
|
|
if (x == null)
|
|
throw new NullPointerException();
|
|
RunnableScheduledFuture<?> e = (RunnableScheduledFuture<?>)x;
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
int i = size;
|
|
if (i >= queue.length)
|
|
grow();
|
|
size = i + 1;
|
|
if (i == 0) {
|
|
queue[0] = e;
|
|
setIndex(e, 0);
|
|
} else {
|
|
siftUp(i, e);
|
|
}
|
|
if (queue[0] == e) {
|
|
leader = null;
|
|
available.signal();
|
|
}
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
public void put(Runnable e) {
|
|
offer(e);
|
|
}
|
|
|
|
public boolean add(Runnable e) {
|
|
return offer(e);
|
|
}
|
|
|
|
public boolean offer(Runnable e, long timeout, TimeUnit unit) {
|
|
return offer(e);
|
|
}
|
|
|
|
/**
|
|
* Performs common bookkeeping for poll and take: Replaces
|
|
* first element with last and sifts it down. Call only when
|
|
* holding lock.
|
|
* @param f the task to remove and return
|
|
*/
|
|
private RunnableScheduledFuture<?> finishPoll(RunnableScheduledFuture<?> f) {
|
|
int s = --size;
|
|
RunnableScheduledFuture<?> x = queue[s];
|
|
queue[s] = null;
|
|
if (s != 0)
|
|
siftDown(0, x);
|
|
setIndex(f, -1);
|
|
return f;
|
|
}
|
|
|
|
public RunnableScheduledFuture<?> poll() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
RunnableScheduledFuture<?> first = queue[0];
|
|
return (first == null || first.getDelay(NANOSECONDS) > 0)
|
|
? null
|
|
: finishPoll(first);
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public RunnableScheduledFuture<?> take() throws InterruptedException {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lockInterruptibly();
|
|
try {
|
|
for (;;) {
|
|
RunnableScheduledFuture<?> first = queue[0];
|
|
if (first == null)
|
|
available.await();
|
|
else {
|
|
long delay = first.getDelay(NANOSECONDS);
|
|
if (delay <= 0L)
|
|
return finishPoll(first);
|
|
first = null; // don't retain ref while waiting
|
|
if (leader != null)
|
|
available.await();
|
|
else {
|
|
Thread thisThread = Thread.currentThread();
|
|
leader = thisThread;
|
|
try {
|
|
available.awaitNanos(delay);
|
|
} finally {
|
|
if (leader == thisThread)
|
|
leader = null;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} finally {
|
|
if (leader == null && queue[0] != null)
|
|
available.signal();
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public RunnableScheduledFuture<?> poll(long timeout, TimeUnit unit)
|
|
throws InterruptedException {
|
|
long nanos = unit.toNanos(timeout);
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lockInterruptibly();
|
|
try {
|
|
for (;;) {
|
|
RunnableScheduledFuture<?> first = queue[0];
|
|
if (first == null) {
|
|
if (nanos <= 0L)
|
|
return null;
|
|
else
|
|
nanos = available.awaitNanos(nanos);
|
|
} else {
|
|
long delay = first.getDelay(NANOSECONDS);
|
|
if (delay <= 0L)
|
|
return finishPoll(first);
|
|
if (nanos <= 0L)
|
|
return null;
|
|
first = null; // don't retain ref while waiting
|
|
if (nanos < delay || leader != null)
|
|
nanos = available.awaitNanos(nanos);
|
|
else {
|
|
Thread thisThread = Thread.currentThread();
|
|
leader = thisThread;
|
|
try {
|
|
long timeLeft = available.awaitNanos(delay);
|
|
nanos -= delay - timeLeft;
|
|
} finally {
|
|
if (leader == thisThread)
|
|
leader = null;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} finally {
|
|
if (leader == null && queue[0] != null)
|
|
available.signal();
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public void clear() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
for (int i = 0; i < size; i++) {
|
|
RunnableScheduledFuture<?> t = queue[i];
|
|
if (t != null) {
|
|
queue[i] = null;
|
|
setIndex(t, -1);
|
|
}
|
|
}
|
|
size = 0;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public int drainTo(Collection<? super Runnable> c) {
|
|
return drainTo(c, Integer.MAX_VALUE);
|
|
}
|
|
|
|
public int drainTo(Collection<? super Runnable> c, int maxElements) {
|
|
Objects.requireNonNull(c);
|
|
if (c == this)
|
|
throw new IllegalArgumentException();
|
|
if (maxElements <= 0)
|
|
return 0;
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
int n = 0;
|
|
for (RunnableScheduledFuture<?> first;
|
|
n < maxElements
|
|
&& (first = queue[0]) != null
|
|
&& first.getDelay(NANOSECONDS) <= 0;) {
|
|
c.add(first); // In this order, in case add() throws.
|
|
finishPoll(first);
|
|
++n;
|
|
}
|
|
return n;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public Object[] toArray() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
return Arrays.copyOf(queue, size, Object[].class);
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
@SuppressWarnings("unchecked")
|
|
public <T> T[] toArray(T[] a) {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
if (a.length < size)
|
|
return (T[]) Arrays.copyOf(queue, size, a.getClass());
|
|
System.arraycopy(queue, 0, a, 0, size);
|
|
if (a.length > size)
|
|
a[size] = null;
|
|
return a;
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
public Iterator<Runnable> iterator() {
|
|
final ReentrantLock lock = this.lock;
|
|
lock.lock();
|
|
try {
|
|
return new Itr(Arrays.copyOf(queue, size));
|
|
} finally {
|
|
lock.unlock();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Snapshot iterator that works off copy of underlying q array.
|
|
*/
|
|
private class Itr implements Iterator<Runnable> {
|
|
final RunnableScheduledFuture<?>[] array;
|
|
int cursor; // index of next element to return; initially 0
|
|
int lastRet = -1; // index of last element returned; -1 if no such
|
|
|
|
Itr(RunnableScheduledFuture<?>[] array) {
|
|
this.array = array;
|
|
}
|
|
|
|
public boolean hasNext() {
|
|
return cursor < array.length;
|
|
}
|
|
|
|
public Runnable next() {
|
|
if (cursor >= array.length)
|
|
throw new NoSuchElementException();
|
|
return array[lastRet = cursor++];
|
|
}
|
|
|
|
public void remove() {
|
|
if (lastRet < 0)
|
|
throw new IllegalStateException();
|
|
DelayedWorkQueue.this.remove(array[lastRet]);
|
|
lastRet = -1;
|
|
}
|
|
}
|
|
}
|
|
}
|