1 /***
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Exoffice Technologies. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Exoffice Technologies. Exolab is a registered
23 * trademark of Exoffice Technologies.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 2000-2002 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: ThreadPoolManager.java,v 1.4 2003/08/07 13:33:10 tanderson Exp $
44 *
45 * Date Author Changes
46 * 11/23/00 jima Created
47 */
48 package org.exolab.jms.threads;
49
50
51
52 import java.util.HashMap;
53
54 import org.exolab.core.service.BasicService;
55 import org.exolab.core.service.ServiceException;
56 import org.exolab.core.service.ServiceState;
57 import org.exolab.core.threadPool.ThreadPool;
58
59
60 /***
61 * The thread pool manager manages all the required {@link ThreadPool}
62 * objects.
63 * The clients can obtain a ThreadPool from the {@link ThreadPoolManager} with
64 * a given number of Threads.
65 * <p>
66 * The manager keeps a list of all The ThreadPools it has dished out with a
67 * unique client provided name. Client can then re-request the already created
68 * ThreadPool or share common ThreadPools if required.
69 * <p>
70 * The ThreadPool manager will attempt to shutdown all ThreadPools and
71 * stop all Threads when it receives a stop request.
72 * <p>
73 * If a client attempts to create a ThreadPool with a name that already
74 * exists a ThreadPoolExistsException will be raised and the creation
75 * will fail.
76 *
77 * @version $Revision: 1.4 $ $Date: 2003/08/07 13:33:10 $
78 * @author <a href="mailto:mourikis@intalio.com">Jim Mourikis</a>
79 **/
80 public class ThreadPoolManager extends BasicService {
81
82
83 private static HashMap _pools = null;
84
85
86 private static ThreadPoolManager _instance = null;
87
88
89 private static final String THREADPOOLMGR_NAME = "ThreadPoolManager";
90
91
92 /***
93 * The constructor initialises the parent, and creates an empty container
94 * to hold the thread pools, as they are requested.
95 *
96 * <P> Entry into this constructor is only through the intialise method
97 * below. Note only one instance of this mgr is created.
98 */
99 private ThreadPoolManager() {
100 super(THREADPOOLMGR_NAME);
101 _pools = new HashMap();
102 }
103
104 /***
105 * Return the one and only instance of the ThreadPoolManager.
106 *
107 * <P>Note: Initiase must be called above to initialise the pool, else
108 * a null object will be returned.
109 */
110 static public ThreadPoolManager instance() {
111 if (_instance == null) {
112 _instance = new ThreadPoolManager();
113 }
114 return _instance;
115 }
116
117 /***
118 * A client has requested a new thread pool creation with the given name.
119 * if the named Pool has not already been created, then create it
120 * add it to the list, and return it to the client.
121 *
122 * @param name The unique name given to this ThreadPool
123 * @param size The maximum nuber of Threads this pool contains.
124 * @throws ThreadPoolExistsException if the pool with the given name
125 * already exists.
126 */
127 public ThreadPool createThreadPool(String name, int size)
128 throws ThreadPoolExistsException {
129 synchronized (_pools) {
130 if (_pools.containsKey(name)) {
131 throw new ThreadPoolExistsException("ThreadPool with name " +
132 name + " exists");
133 }
134 ThreadPool pool = new ThreadPool(name, size, true);
135
136 _pools.put(name, pool);
137 return pool;
138 }
139 }
140
141 /***
142 * Get the ThreadPool with the given name. if the named pool does not exist
143 * throw an exception.
144 *
145 * @param name The unique name of the requested ThreadPool
146 * @throws UnknownThreadPoolException if the pool with the given name
147 * does not exist.
148 */
149 public ThreadPool getThreadPool(String name)
150 throws UnknownThreadPoolException {
151 ThreadPool pool = null;
152
153 synchronized (_pools) {
154 pool = (ThreadPool) _pools.get(name);
155 }
156
157 if (pool == null) {
158 throw new UnknownThreadPoolException("ThreadPool with name " +
159 name + " does not exist");
160 }
161
162 return pool;
163 }
164
165 /***
166 * Attempts to shutdown all the threads in the pool and removes the given
167 * ThreadPool.
168 *
169 * @param name The unique name of the requested ThreadPool
170 * @throws UnknownThreadPoolException if the pool with the given name
171 * does not exist.
172 */
173 public void deleteThreadPool(String name)
174 throws UnknownThreadPoolException {
175 ThreadPool pool = null;
176
177 synchronized (_pools) {
178 pool = (ThreadPool) _pools.remove(name);
179 }
180
181 if (pool == null) {
182 throw new UnknownThreadPoolException("ThreadPool with name " +
183 name + " does not exist");
184 }
185 pool.stopRequestAllWorkers();
186 }
187
188 /***
189 * This starts the ThreadPoolManager's thread
190 */
191 public synchronized void run() {
192 while (getState() != ServiceState.STOPPED) {
193 try {
194
195 wait();
196 } catch (InterruptedException ignore) {
197 }
198 }
199 }
200
201 /***
202 * Overide BasicService.stop. Clean up all thread pools,
203 * by calling their stop methods.
204 *
205 * @throws ServiceException
206 */
207 public void stop() throws ServiceException {
208 synchronized (_pools) {
209 Object[] ob = _pools.values().toArray();
210
211 for (int i = 0, j = _pools.size(); i < j; i++) {
212 ((ThreadPool) ob[i]).stopRequestAllWorkers();
213 }
214 _pools.clear();
215 }
216 super.stop();
217
218 _pools = null;
219 _instance = null;
220 }
221
222 }