001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * The contents of this file are subject to the terms of either the GNU
007: * General Public License Version 2 only ("GPL") or the Common Development
008: * and Distribution License("CDDL") (collectively, the "License"). You
009: * may not use this file except in compliance with the License. You can obtain
010: * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
011: * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
012: * language governing permissions and limitations under the License.
013: *
014: * When distributing the software, include this License Header Notice in each
015: * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
016: * Sun designates this particular file as subject to the "Classpath" exception
017: * as provided by Sun in the GPL Version 2 section of the License file that
018: * accompanied this code. If applicable, add the following below the License
019: * Header, with the fields enclosed by brackets [] replaced by your own
020: * identifying information: "Portions Copyrighted [year]
021: * [name of copyright owner]"
022: *
023: * Contributor(s):
024: *
025: * If you wish your version of this file to be governed by only the CDDL or
026: * only the GPL Version 2, indicate your decision by adding "[Contributor]
027: * elects to include this software in this distribution under the [CDDL or GPL
028: * Version 2] license." If you don't indicate a single choice of license, a
029: * recipient has the option to distribute your version of this file under
030: * either the CDDL, the GPL Version 2 or to extend the choice of license to
031: * its licensees as provided above. However, if you add GPL Version 2 code
032: * and therefore, elected the GPL Version 2 license, then the option applies
033: * only if the new code is made subject to such option by the copyright
034: * holder.
035: */
036:
037: /*
038: * @(#)EventQueue.java 1.11 07/05/04
039: */
040:
041: package javax.mail;
042:
043: import java.io.*;
044: import java.util.Vector;
045: import javax.mail.event.MailEvent;
046:
047: /**
048: * Package private class used by Store & Folder to dispatch events.
049: * This class implements an event queue, and a dispatcher thread that
050: * dequeues and dispatches events from the queue.
051: *
052: * Pieces stolen from sun.misc.Queue.
053: *
054: * @author Bill Shannon
055: */
056: class EventQueue implements Runnable {
057:
058: static class QueueElement {
059: QueueElement next = null;
060: QueueElement prev = null;
061: MailEvent event = null;
062: Vector vector = null;
063:
064: QueueElement(MailEvent event, Vector vector) {
065: this .event = event;
066: this .vector = vector;
067: }
068: }
069:
070: private QueueElement head = null;
071: private QueueElement tail = null;
072: private Thread qThread;
073:
074: public EventQueue() {
075: qThread = new Thread(this , "JavaMail-EventQueue");
076: qThread.setDaemon(true); // not a user thread
077: qThread.start();
078: }
079:
080: /**
081: * Enqueue an event.
082: */
083: public synchronized void enqueue(MailEvent event, Vector vector) {
084: QueueElement newElt = new QueueElement(event, vector);
085:
086: if (head == null) {
087: head = newElt;
088: tail = newElt;
089: } else {
090: newElt.next = head;
091: head.prev = newElt;
092: head = newElt;
093: }
094: notifyAll();
095: }
096:
097: /**
098: * Dequeue the oldest object on the queue.
099: * Used only by the run() method.
100: *
101: * @return the oldest object on the queue.
102: * @exception java.lang.InterruptedException if another thread has
103: * interrupted this thread.
104: */
105: private synchronized QueueElement dequeue()
106: throws InterruptedException {
107: while (tail == null)
108: wait();
109: QueueElement elt = tail;
110: tail = elt.prev;
111: if (tail == null) {
112: head = null;
113: } else {
114: tail.next = null;
115: }
116: elt.prev = elt.next = null;
117: return elt;
118: }
119:
120: /**
121: * Pull events off the queue and dispatch them.
122: */
123: public void run() {
124: QueueElement qe;
125:
126: try {
127: loop: while ((qe = dequeue()) != null) {
128: MailEvent e = qe.event;
129: Vector v = qe.vector;
130:
131: for (int i = 0; i < v.size(); i++)
132: try {
133: e.dispatch(v.elementAt(i));
134: } catch (Throwable t) {
135: if (t instanceof InterruptedException)
136: break loop;
137: // ignore anything else thrown by the listener
138: }
139:
140: qe = null;
141: e = null;
142: v = null;
143: }
144: } catch (InterruptedException e) {
145: // just die
146: }
147: }
148:
149: /**
150: * Stop the dispatcher so we can be destroyed.
151: */
152: void stop() {
153: if (qThread != null) {
154: qThread.interrupt(); // kill our thread
155: qThread = null;
156: }
157: }
158: }
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