0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * This file is available under and governed by the GNU General Public 0N/A * License version 2 only, as published by the Free Software Foundation. 0N/A * However, the following notice accompanied the original version of this 0N/A * Written by Doug Lea with assistance from members of JCP JSR-166 0N/A * Expert Group and released to the public domain, as explained at 0N/A * An object that executes submitted {@link Runnable} tasks. This 0N/A * interface provides a way of decoupling task submission from the 0N/A * mechanics of how each task will be run, including details of thread 0N/A * use, scheduling, etc. An <tt>Executor</tt> is normally used 0N/A * instead of explicitly creating threads. For example, rather than 0N/A * invoking <tt>new Thread(new(RunnableTask())).start()</tt> for each 0N/A * of a set of tasks, you might use: 0N/A * Executor executor = <em>anExecutor</em>; 0N/A * executor.execute(new RunnableTask1()); 0N/A * executor.execute(new RunnableTask2()); 0N/A * However, the <tt>Executor</tt> interface does not strictly 0N/A * require that execution be asynchronous. In the simplest case, an 0N/A * executor can run the submitted task immediately in the caller's 0N/A * class DirectExecutor implements Executor { 0N/A * public void execute(Runnable r) { 0N/A * More typically, tasks are executed in some thread other 0N/A * than the caller's thread. The executor below spawns a new thread 0N/A * class ThreadPerTaskExecutor implements Executor { 0N/A * public void execute(Runnable r) { 0N/A * new Thread(r).start(); 0N/A * Many <tt>Executor</tt> implementations impose some sort of 0N/A * limitation on how and when tasks are scheduled. The executor below 0N/A * serializes the submission of tasks to a second executor, 0N/A * illustrating a composite executor. 0N/A * class SerialExecutor implements Executor { 3203N/A * final Queue<Runnable> tasks = new ArrayDeque<Runnable>(); 3203N/A * SerialExecutor(Executor executor) { 3203N/A * this.executor = executor; 3203N/A * public synchronized void execute(final Runnable r) { 3203N/A * tasks.offer(new Runnable() { 3203N/A * protected synchronized void scheduleNext() { 3203N/A * if ((active = tasks.poll()) != null) { 3203N/A * executor.execute(active); 0N/A * The <tt>Executor</tt> implementations provided in this package 0N/A * implement {@link ExecutorService}, which is a more extensive 0N/A * interface. The {@link ThreadPoolExecutor} class provides an 0N/A * extensible thread pool implementation. The {@link Executors} class 0N/A * provides convenient factory methods for these Executors. 0N/A * <p>Memory consistency effects: Actions in a thread prior to 0N/A * submitting a {@code Runnable} object to an {@code Executor} 0N/A * its execution begins, perhaps in another thread. 0N/A * Executes the given command at some time in the future. The command 0N/A * may execute in a new thread, in a pooled thread, or in the calling 0N/A * thread, at the discretion of the <tt>Executor</tt> implementation. 0N/A * @param command the runnable task 0N/A * @throws RejectedExecutionException if this task cannot be 0N/A * accepted for execution. 0N/A * @throws NullPointerException if command is null