Importing upstream Jetty jetty-9.2.1.v20140609

[gigi.git] / lib / jetty / org / eclipse / jetty / util / thread / TimerScheduler.java

diff --git a/lib/jetty/org/eclipse/jetty/util/thread/TimerScheduler.java b/lib/jetty/org/eclipse/jetty/util/thread/TimerScheduler.java
new file mode 100644 (file)
index 0000000..c07390a
--- /dev/null
+++ b/lib/jetty/org/eclipse/jetty/util/thread/TimerScheduler.java
@@ -0,0 +1,129 @@
+//
+//  ========================================================================
+//  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.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import org.eclipse.jetty.util.component.AbstractLifeCycle;
+import org.eclipse.jetty.util.log.Log;
+import org.eclipse.jetty.util.log.Logger;
+
+
+/* ------------------------------------------------------------ */
+/** A scheduler based on the the JVM Timer class
+ */
+public class TimerScheduler extends AbstractLifeCycle implements Scheduler, Runnable
+{
+    private static final Logger LOG = Log.getLogger(TimerScheduler.class);
+
+    /*
+     * This class uses the Timer class rather than an ScheduledExecutionService because
+     * it uses the same algorithm internally and the signature is cheaper to use as there are no
+     * Futures involved (which we do not need).
+     * However, Timer is still locking and a concurrent queue would be better.
+     */
+
+    private final String _name;
+    private final boolean _daemon;
+    private Timer _timer;
+
+    public TimerScheduler()
+    {
+        this(null, false);
+    }
+
+    public TimerScheduler(String name, boolean daemon)
+    {
+        _name = name;
+        _daemon = daemon;
+    }
+
+    @Override
+    protected void doStart() throws Exception
+    {
+        _timer = _name == null ? new Timer() : new Timer(_name, _daemon);
+        run();
+        super.doStart();
+    }
+
+    @Override
+    protected void doStop() throws Exception
+    {
+        _timer.cancel();
+        super.doStop();
+        _timer = null;
+    }
+
+    @Override
+    public Task schedule(final Runnable task, final long delay, final TimeUnit units)
+    {
+        Timer timer = _timer;
+        if (timer == null)
+            throw new RejectedExecutionException("STOPPED: " + this);
+        SimpleTask t = new SimpleTask(task);
+        timer.schedule(t, units.toMillis(delay));
+        return t;
+    }
+
+    @Override
+    public void run()
+    {
+        Timer timer = _timer;
+        if (timer != null)
+        {
+            timer.purge();
+            schedule(this, 1, TimeUnit.SECONDS);
+        }
+    }
+
+    private static class SimpleTask extends TimerTask implements Task
+    {
+        private final Runnable _task;
+
+        private SimpleTask(Runnable runnable)
+        {
+            _task = runnable;
+        }
+
+        @Override
+        public void run()
+        {
+            try
+            {
+                _task.run();
+            }
+            catch (Throwable x)
+            {
+                LOG.debug("Exception while executing task " + _task, x);
+            }
+        }
+
+        @Override
+        public String toString()
+        {
+            return String.format("%s.%s@%x",
+                    TimerScheduler.class.getSimpleName(),
+                    SimpleTask.class.getSimpleName(),
+                    hashCode());
+        }
+    }
+}