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Java > Open Source Codes > org > apache > mina > common > ExecutorThreadModel


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License. You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied. See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  *
19  */
20 package org.apache.mina.common;
21
22 import java.util.HashMap JavaDoc;
23 import java.util.Map JavaDoc;
24 import java.util.concurrent.Executor JavaDoc;
25 import java.util.concurrent.ThreadFactory JavaDoc;
26 import java.util.concurrent.ThreadPoolExecutor JavaDoc;
27 import java.util.concurrent.atomic.AtomicInteger JavaDoc;
28
29 import org.apache.mina.filter.executor.ExecutorFilter;
30
31 /**
32  * A {@link ThreadModel} which represents a thread model with an {@link Executor}
33  * per service. The default underlying {@link Executor} is {@link ThreadPoolExecutor},
34  * so you can safely downcast the returned {@link Executor} of {@link #getExecutor()} to
35  * {@link ThreadPoolExecutor} by default.
36  *
37  * @author The Apache Directory Project (mina-dev@directory.apache.org)
38  * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (금, 13 7월 2007) $
39  */
40 public class ExecutorThreadModel implements ThreadModel {
41     /**
42      * Maps a service name to a PooledThreadModel instance.
43      * Without this map, we might create extremely many thread pools that leads the system to
44      * coma. */
45     private static final Map JavaDoc<String JavaDoc, ExecutorThreadModel> service2model = new HashMap JavaDoc<String JavaDoc, ExecutorThreadModel>();
46
47     /**
48      * Returns a {@link ExecutorThreadModel} instance for the specified <tt>serviceName</tt>.
49      * Please note that all returned instances will be managed globally; the same instance
50      * will be returned if you specified the same service name. Please try to specify
51      * different names for different services.
52      *
53      * @param serviceName the name of the service that needs thread pooling
54      */
55     public static ExecutorThreadModel getInstance(String JavaDoc serviceName) {
56         if (serviceName == null) {
57             throw new NullPointerException JavaDoc("serviceName");
58         }
59
60         ExecutorThreadModel model;
61         synchronized (service2model) {
62             model = service2model.get(serviceName);
63             if (model == null) {
64                 model = new ExecutorThreadModel(serviceName);
65                 service2model.put(serviceName, model);
66             }
67         }
68
69         return model;
70     }
71
72     private final String JavaDoc threadNamePrefix;
73
74     private final ExecutorFilter defaultFilter;
75
76     private ExecutorFilter filter = new ExecutorFilter();
77
78     private ExecutorThreadModel(String JavaDoc threadNamePrefix) {
79         this.threadNamePrefix = threadNamePrefix;
80
81         // Create the default filter
82 defaultFilter = new ExecutorFilter();
83         ThreadPoolExecutor JavaDoc tpe = (ThreadPoolExecutor JavaDoc) defaultFilter
84                 .getExecutor();
85         final ThreadFactory JavaDoc originalThreadFactory = tpe.getThreadFactory();
86         ThreadFactory JavaDoc newThreadFactory = new ThreadFactory JavaDoc() {
87             private final AtomicInteger JavaDoc threadId = new AtomicInteger JavaDoc(0);
88
89             public Thread JavaDoc newThread(Runnable JavaDoc runnable) {
90                 Thread JavaDoc t = originalThreadFactory.newThread(runnable);
91                 t.setName(ExecutorThreadModel.this.threadNamePrefix + '-'
92                         + threadId.incrementAndGet());
93                 t.setDaemon(true);
94                 return t;
95             }
96         };
97         tpe.setThreadFactory(newThreadFactory);
98
99         // Set to default.
100 setExecutor(null);
101     }
102
103     /**
104      * Returns the underlying {@link Executor} of this model.
105      * You can change various properties such as the number of threads
106      * by calling methods of the {@link Executor} implementation.
107      */
108     public Executor JavaDoc getExecutor() {
109         return filter.getExecutor();
110     }
111
112     /**
113      * Changes the underlying {@link Executor} of this model.
114      * Previous settings such as the number of threads should be configured again.
115      * Only newly created {@link IoSession}s will be affected.
116      *
117      * @param executor <tt>null</tt> to revert to the default setting
118      */
119     public void setExecutor(Executor JavaDoc executor) {
120         if (executor == null) {
121             filter = defaultFilter;
122         } else {
123             filter = new ExecutorFilter(executor);
124         }
125     }
126
127     public void buildFilterChain(IoFilterChain chain) throws Exception JavaDoc {
128         chain.addFirst(ExecutorThreadModel.class.getName(), filter);
129     }
130 }
131
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