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Java > Open Source Codes > com > jcorporate > expresso > services > asyncprocess > ProcessThread


1 /* ====================================================================
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61  * Portions of this software are based upon other open source
62  * products and are subject to their respective licenses.
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64
65 package com.jcorporate.expresso.services.asyncprocess;
66
67 /**
68  * Thread that processes asynchronous requests.
69  * @author Michael Rimov
70  * @version $Revision: 1.7 $ on $Date: 2004/11/17 20:48:17 $
71  */
72
73 import com.jcorporate.expresso.core.registry.ExpressoThread;
74
75 import java.util.LinkedList JavaDoc;
76
77 public class ProcessThread extends ExpressoThread {
78     private boolean done = false;
79
80     /**
81      * Our parent
82      */
83     DefaultAsyncProcessor parent;
84
85     /**
86      * The current process. null if none current
87      */
88     DefaultAsyncProcessor.ProcessWrapper curProcess = null;
89
90     /**
91      * USed to make sure curProcess doesn't turn null midst of our manipulation
92      * of it.
93      */
94     Object JavaDoc writeLock = new Object JavaDoc();
95
96     /**
97      * Constructor
98      *
99      * @param processor the processor that launched the thread
100      * @param group the threadgroup that this thread belongs to
101      * @param name the name of the process thread
102      */
103     public ProcessThread(DefaultAsyncProcessor processor, ThreadGroup JavaDoc group, String JavaDoc name) {
104         super(group, name);
105         parent = processor;
106     }
107
108     /**
109      * Interrupt and cause the thread to exit.
110      */
111     public void interrupt() {
112         done = true;
113         synchronized (writeLock) {
114             if (curProcess != null) {
115                 curProcess.getWrappedObject().kill();
116             }
117         }
118
119         super.interrupt();
120     }
121
122     /**
123      * Run the process wrapper in this thread. If we get interrupted then
124      * we exit.
125      */
126     public void run() {
127         super.run();
128
129         LinkedList JavaDoc queue = parent.getQueue();
130         while (!done) {
131             synchronized (queue) {
132                 if (queue.size() == 0) {
133                     try {
134                         queue.wait();
135                     } catch (InterruptedException JavaDoc ex) {
136                         if (done) {
137                             return;
138                         }
139
140                         continue;
141                     }
142                     synchronized (writeLock) {
143                         curProcess = (DefaultAsyncProcessor.ProcessWrapper) queue.removeFirst();
144                     }
145                 }
146             }
147
148             curProcess.process();
149
150             synchronized (writeLock) {
151                 curProcess = null;
152             }
153         }
154     }
155 }
156
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