| // |
| // ======================================================================== |
| // Copyright (c) 1995-2014 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.util.Arrays; |
| import java.util.List; |
| import java.util.concurrent.CopyOnWriteArrayList; |
| |
| import org.eclipse.jetty.util.component.Destroyable; |
| import org.eclipse.jetty.util.component.LifeCycle; |
| import org.eclipse.jetty.util.log.Log; |
| import org.eclipse.jetty.util.log.Logger; |
| |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * ShutdownThread is a shutdown hook thread implemented as |
| * singleton that maintains a list of lifecycle instances |
| * that are registered with it and provides ability to stop |
| * these lifecycles upon shutdown of the Java Virtual Machine |
| */ |
| public class ShutdownThread extends Thread |
| { |
| private static final Logger LOG = Log.getLogger(ShutdownThread.class); |
| private static final ShutdownThread _thread = new ShutdownThread(); |
| |
| private boolean _hooked; |
| private final List<LifeCycle> _lifeCycles = new CopyOnWriteArrayList<LifeCycle>(); |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * Default constructor for the singleton |
| * |
| * Registers the instance as shutdown hook with the Java Runtime |
| */ |
| private ShutdownThread() |
| { |
| } |
| |
| /* ------------------------------------------------------------ */ |
| private synchronized void hook() |
| { |
| try |
| { |
| if (!_hooked) |
| Runtime.getRuntime().addShutdownHook(this); |
| _hooked=true; |
| } |
| catch(Exception e) |
| { |
| LOG.ignore(e); |
| LOG.info("shutdown already commenced"); |
| } |
| } |
| |
| /* ------------------------------------------------------------ */ |
| private synchronized void unhook() |
| { |
| try |
| { |
| _hooked=false; |
| Runtime.getRuntime().removeShutdownHook(this); |
| } |
| catch(Exception e) |
| { |
| LOG.ignore(e); |
| LOG.debug("shutdown already commenced"); |
| } |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * Returns the instance of the singleton |
| * |
| * @return the singleton instance of the {@link ShutdownThread} |
| */ |
| public static ShutdownThread getInstance() |
| { |
| return _thread; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public static synchronized void register(LifeCycle... lifeCycles) |
| { |
| _thread._lifeCycles.addAll(Arrays.asList(lifeCycles)); |
| if (_thread._lifeCycles.size()>0) |
| _thread.hook(); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public static synchronized void register(int index, LifeCycle... lifeCycles) |
| { |
| _thread._lifeCycles.addAll(index,Arrays.asList(lifeCycles)); |
| if (_thread._lifeCycles.size()>0) |
| _thread.hook(); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public static synchronized void deregister(LifeCycle lifeCycle) |
| { |
| _thread._lifeCycles.remove(lifeCycle); |
| if (_thread._lifeCycles.size()==0) |
| _thread.unhook(); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| @Override |
| public void run() |
| { |
| for (LifeCycle lifeCycle : _thread._lifeCycles) |
| { |
| try |
| { |
| if (lifeCycle.isStarted()) |
| { |
| lifeCycle.stop(); |
| LOG.debug("Stopped {}",lifeCycle); |
| } |
| |
| if (lifeCycle instanceof Destroyable) |
| { |
| ((Destroyable)lifeCycle).destroy(); |
| LOG.debug("Destroyed {}",lifeCycle); |
| } |
| } |
| catch (Exception ex) |
| { |
| LOG.debug(ex); |
| } |
| } |
| } |
| } |