/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License").  You * may not use this file except in compliance with the License. You can obtain * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. * Sun designates this particular file as subject to the "Classpath" exception * as provided by Sun in the GPL Version 2 section of the License file that * accompanied this code.  If applicable, add the following below the License * Header, with the fields enclosed by brackets [] replaced by your own * identifying information: "Portions Copyrighted [year] * [name of copyright owner]" * * Contributor(s): * * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license."  If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above.  However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. *//* * @(#)EventQueue.java	1.11 07/05/04 */package javax.mail;import java.io.*;import java.util.Vector;import javax.mail.event.MailEvent;/** * Package private class used by Store & Folder to dispatch events. * This class implements an event queue, and a dispatcher thread that * dequeues and dispatches events from the queue. * * Pieces stolen from sun.misc.Queue. * * @author	Bill Shannon */class EventQueue implements Runnable {    static class QueueElement {	QueueElement next = null;	QueueElement prev = null;	MailEvent event = null;	Vector vector = null;	QueueElement(MailEvent event, Vector vector) {	    this.event = event;	    this.vector = vector;	}    }    private QueueElement head = null;    private QueueElement tail = null;    private Thread qThread;    public EventQueue() {	qThread = new Thread(this, "JavaMail-EventQueue");	qThread.setDaemon(true);  // not a user thread	qThread.start();    }    /**     * Enqueue an event.     */    public synchronized void enqueue(MailEvent event, Vector vector) {	QueueElement newElt = new QueueElement(event, vector);	if (head == null) {	    head = newElt;	    tail = newElt;	} else {	    newElt.next = head;	    head.prev = newElt;	    head = newElt;	}	notifyAll();    }    /**     * Dequeue the oldest object on the queue.     * Used only by the run() method.     *     * @return    the oldest object on the queue.     * @exception java.lang.InterruptedException if another thread has     *              interrupted this thread.     */    private synchronized QueueElement dequeue()				throws InterruptedException {	while (tail == null)	    wait();	QueueElement elt = tail;	tail = elt.prev;	if (tail == null) {	    head = null;	} else {	    tail.next = null;	}	elt.prev = elt.next = null;	return elt;    }    /**     * Pull events off the queue and dispatch them.     */    public void run() {	QueueElement qe;	try {	    loop:	    while ((qe = dequeue()) != null) {		MailEvent e = qe.event;		Vector v = qe.vector;		for (int i = 0; i < v.size(); i++)		    try {			e.dispatch(v.elementAt(i));		    } catch (Throwable t) {			if (t instanceof InterruptedException)			    break loop;			// ignore anything else thrown by the listener		    }		qe = null; e = null; v = null;	    }	} catch (InterruptedException e) {	    // just die	}    }    /**     * Stop the dispatcher so we can be destroyed.     */    void stop() {	if (qThread != null) {	    qThread.interrupt();	// kill our thread	    qThread = null;	}    }}