| /* EventDispatcher.java -- Dispatch events for prefs |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.util.prefs; |
| |
| import java.util.ArrayList; |
| |
| /** |
| * This is a helper class used for dispatching events for |
| * the prefs package. |
| */ |
| public class EventDispatcher extends Thread |
| { |
| // This is a singleton class. We dispatch all events via a |
| // new Thread which is created on demand. |
| private static final Thread dispatchThread = new EventDispatcher(); |
| |
| // This is a queue of events to dispatch. This thread waits on |
| // the queue and when notified will remove events until the queue |
| // is empty. |
| private static final ArrayList queue = new ArrayList(); |
| |
| // FIXME: this thread probably ought to go in some classpath-internal |
| // ThreadGroup. But we don't have that yet. |
| private EventDispatcher() |
| { |
| setDaemon(true); |
| start(); |
| } |
| |
| public void run() |
| { |
| while (true) |
| { |
| Runnable r; |
| synchronized (queue) |
| { |
| while (queue.size() == 0) |
| { |
| try |
| { |
| queue.wait(); |
| } |
| catch (InterruptedException _) |
| { |
| // Ignore. |
| } |
| } |
| r = (Runnable) queue.remove(0); |
| } |
| // Invoke outside the synchronization, so that |
| // we aren't blocking other threads from posting events. |
| try |
| { |
| r.run(); |
| } |
| catch (Throwable _) |
| { |
| // Ignore. |
| } |
| } |
| } |
| |
| /** |
| * Add a new runnable to the event dispatch queue. The |
| * runnable will be invoked in the event dispatch queue |
| * without any locks held. |
| * @param runner the Runnable to dispatch |
| */ |
| public static void dispatch(Runnable runner) |
| { |
| synchronized (queue) |
| { |
| queue.add(runner); |
| queue.notify(); |
| } |
| } |
| } |