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1 /*
2  * Copyright 1999,2005 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.log4j;
18
19 import org.apache.log4j.helpers.AppenderAttachableImpl;
20 import org.apache.log4j.spi.LoggingEvent;
21
22
23 /**
24  * Obsolete AsyncAppender dispatcher provided for compatibility only.
25  *
26  * @deprecated Since 1.3.
27  */
28 class Dispatcher extends Thread JavaDoc {
29     /**
30      * @deprecated
31      */
32   private org.apache.log4j.helpers.BoundedFIFO bf;
33   private AppenderAttachableImpl aai;
34   private boolean interrupted = false;
35   AsyncAppender container;
36
37     /**
38      *
39      * @param bf
40      * @param container
41      * @deprecated
42      */
43   Dispatcher(org.apache.log4j.helpers.BoundedFIFO bf, AsyncAppender container) {
44     this.bf = bf;
45     this.container = container;
46     this.aai = container.aai;
47
48     // It is the user's responsibility to close appenders before
49 // exiting.
50 this.setDaemon(true);
51
52     // set the dispatcher priority to lowest possible value
53 this.setPriority(Thread.MIN_PRIORITY);
54     this.setName("Dispatcher-" + getName());
55
56     // set the dispatcher priority to MIN_PRIORITY plus or minus 2
57 // depending on the direction of MIN to MAX_PRIORITY.
58 //+ (Thread.MAX_PRIORITY > Thread.MIN_PRIORITY ? 1 : -1)*2);
59 }
60
61   void close() {
62     synchronized (bf) {
63       interrupted = true;
64
65       // We have a waiting dispacther if and only if bf.length is
66 // zero. In that case, we need to give it a death kiss.
67 if (bf.length() == 0) {
68         bf.notify();
69       }
70     }
71   }
72
73   /**
74    * The dispatching strategy is to wait until there are events in the buffer
75    * to process. After having processed an event, we release the monitor
76    * (variable bf) so that new events can be placed in the buffer, instead of
77    * keeping the monitor and processing the remaining events in the buffer.
78    *
79    * <p>
80    * Other approaches might yield better results.
81    * </p>
82    */
83   public void run() {
84     //Category cat = Category.getInstance(Dispatcher.class.getName());
85 LoggingEvent event;
86
87     while (true) {
88       synchronized (bf) {
89         if (bf.length() == 0) {
90           // Exit loop if interrupted but only if the the buffer is empty.
91 if (interrupted) {
92             //cat.info("Exiting.");
93 break;
94           }
95
96           try {
97             //LogLog.debug("Waiting for new event to dispatch.");
98 bf.wait();
99           } catch (InterruptedException JavaDoc e) {
100             break;
101           }
102         }
103
104         event = bf.get();
105
106         if (bf.wasFull()) {
107           //LogLog.debug("Notifying AsyncAppender about freed space.");
108 bf.notify();
109         }
110       }
111
112       // synchronized
113 synchronized (container.aai) {
114         if ((aai != null) && (event != null)) {
115           aai.appendLoopOnAppenders(event);
116         }
117       }
118     }
119
120     // while
121 // close and remove all appenders
122 aai.removeAllAppenders();
123   }
124 }
125
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