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Java > Open Source Codes > com > protomatter > util > MutexObject


1 package com.protomatter.util;
2
3 /**
4  * {{{ The Protomatter Software License, Version 1.0
5  * derived from The Apache Software License, Version 1.1
6  *
7  * Copyright (c) 1998-2002 Nate Sammons. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  * notice, this list of conditions and the following disclaimer in
18  * the documentation and/or other materials provided with the
19  * distribution.
20  *
21  * 3. The end-user documentation included with the redistribution,
22  * if any, must include the following acknowledgment:
23  * "This product includes software developed for the
24  * Protomatter Software Project
25  * (http://protomatter.sourceforge.net/)."
26  * Alternately, this acknowledgment may appear in the software itself,
27  * if and wherever such third-party acknowledgments normally appear.
28  *
29  * 4. The names "Protomatter" and "Protomatter Software Project" must
30  * not be used to endorse or promote products derived from this
31  * software without prior written permission. For written
32  * permission, please contact support@protomatter.com.
33  *
34  * 5. Products derived from this software may not be called "Protomatter",
35  * nor may "Protomatter" appear in their name, without prior written
36  * permission of the Protomatter Software Project
37  * (support@protomatter.com).
38  *
39  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42  * DISCLAIMED. IN NO EVENT SHALL THE PROTOMATTER SOFTWARE PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE. }}}
51  */
52
53 import com.protomatter.pool.*;
54 import com.protomatter.syslog.Syslog;
55 import java.util.*;
56
57 /**
58  * This is the "meat" of the Mutex. It's just
59  * an object pool with 1 object in it.
60  */
61 class MutexObject
62 extends GrowingObjectPool
63 {
64   private boolean initialized = false;
65
66   public MutexObject()
67   {
68     Hashtable args = new Hashtable();
69     args.put("pool.initialSize", new Integer JavaDoc(0));
70     args.put("pool.maxSize", new Integer JavaDoc(1));
71     init(args);
72   }
73
74   /**
75    * Initialize the mutex. Don't call this -- it's already called
76    * by the constructor.
77    *
78    * @see com.protomatter.pool.GrowingObjectPool#init
79    * @exception Exception If there is a problem initializing the mutex.
80    */
81   public void init(Hashtable args)
82   {
83     // don't initialize twice
84 if (this.initialized == true)
85       return;
86     this.initialized = true;
87     try
88     {
89       super.init(args);
90     }
91     catch (Exception JavaDoc x)
92     {
93       ; // this can't happen since createObjectPoolObject()
94 // doesn't throw an exception.
95 }
96   }
97
98   /**
99    * Used internally for growing the pool.
100    *
101    * @exception Exception If there is a problem creating a token.
102    */
103   protected ObjectPoolObject createObjectPoolObject()
104   {
105     return new MutexToken();
106   }
107
108   /**
109    * Get the synchronization lock object.
110    */
111   public Object JavaDoc getSyncObject()
112   {
113     return super.getSyncObject();
114   }
115 }
116
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