| // |
| // ======================================================================== |
| // Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // All rights reserved. This program and the accompanying materials |
| // are made available under the terms of the Eclipse Public License v1.0 |
| // and Apache License v2.0 which accompanies this distribution. |
| // |
| // The Eclipse Public License is available at |
| // http://www.eclipse.org/legal/epl-v10.html |
| // |
| // The Apache License v2.0 is available at |
| // http://www.opensource.org/licenses/apache2.0.php |
| // |
| // You may elect to redistribute this code under either of these licenses. |
| // ======================================================================== |
| // |
| |
| package org.eclipse.jetty.util.thread; |
| |
| import java.io.IOException; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.concurrent.ScheduledFuture; |
| import java.util.concurrent.ScheduledThreadPoolExecutor; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.eclipse.jetty.util.component.AbstractLifeCycle; |
| import org.eclipse.jetty.util.component.ContainerLifeCycle; |
| import org.eclipse.jetty.util.component.Dumpable; |
| |
| /** |
| * Implementation of {@link Scheduler} based on JDK's {@link ScheduledThreadPoolExecutor}. |
| * <p /> |
| * While use of {@link ScheduledThreadPoolExecutor} creates futures that will not be used, |
| * it has the advantage of allowing to set a property to remove cancelled tasks from its |
| * queue even if the task did not fire, which provides a huge benefit in the performance |
| * of garbage collection in young generation. |
| */ |
| public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Scheduler, Dumpable |
| { |
| private final String name; |
| private final boolean daemon; |
| private final ClassLoader classloader; |
| private volatile ScheduledThreadPoolExecutor scheduler; |
| private volatile Thread thread; |
| |
| public ScheduledExecutorScheduler() |
| { |
| this(null, false); |
| } |
| |
| public ScheduledExecutorScheduler(String name, boolean daemon) |
| { |
| this (name,daemon, Thread.currentThread().getContextClassLoader()); |
| } |
| |
| public ScheduledExecutorScheduler(String name, boolean daemon, ClassLoader threadFactoryClassLoader) |
| { |
| this.name = name == null ? "Scheduler-" + hashCode() : name; |
| this.daemon = daemon; |
| this.classloader = threadFactoryClassLoader; |
| } |
| |
| @Override |
| protected void doStart() throws Exception |
| { |
| scheduler = new ScheduledThreadPoolExecutor(1, new ThreadFactory() |
| { |
| @Override |
| public Thread newThread(Runnable r) |
| { |
| Thread thread = ScheduledExecutorScheduler.this.thread = new Thread(r, name); |
| thread.setDaemon(daemon); |
| thread.setContextClassLoader(classloader); |
| return thread; |
| } |
| }); |
| scheduler.setRemoveOnCancelPolicy(true); |
| super.doStart(); |
| } |
| |
| @Override |
| protected void doStop() throws Exception |
| { |
| scheduler.shutdownNow(); |
| super.doStop(); |
| scheduler = null; |
| } |
| |
| @Override |
| public Task schedule(Runnable task, long delay, TimeUnit unit) |
| { |
| ScheduledThreadPoolExecutor s = scheduler; |
| if (s==null) |
| return new Task(){ |
| @Override |
| public boolean cancel() |
| { |
| return false; |
| }}; |
| |
| ScheduledFuture<?> result = s.schedule(task, delay, unit); |
| return new ScheduledFutureTask(result); |
| } |
| |
| @Override |
| public String dump() |
| { |
| return ContainerLifeCycle.dump(this); |
| } |
| |
| @Override |
| public void dump(Appendable out, String indent) throws IOException |
| { |
| ContainerLifeCycle.dumpObject(out, this); |
| Thread thread = this.thread; |
| if (thread != null) |
| { |
| List<StackTraceElement> frames = Arrays.asList(thread.getStackTrace()); |
| ContainerLifeCycle.dump(out, indent, frames); |
| } |
| } |
| |
| private class ScheduledFutureTask implements Task |
| { |
| private final ScheduledFuture<?> scheduledFuture; |
| |
| public ScheduledFutureTask(ScheduledFuture<?> scheduledFuture) |
| { |
| this.scheduledFuture = scheduledFuture; |
| } |
| |
| @Override |
| public boolean cancel() |
| { |
| return scheduledFuture.cancel(false); |
| } |
| } |
| } |