DefaultThreadControl


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17  
18  package org.apache.james.util.thread;
19  
20  import org.apache.avalon.excalibur.thread.ThreadControl;
21  
22  /**
23   * Default implementation of ThreadControl interface.
24   *
25   */
26  final class DefaultThreadControl
27     implements ThreadControl
28  {
29      ///Thread that this control is associated with
30         private Thread   m_thread;
31  
32      ///Throwable that caused thread to terminate
33         private Throwable   m_throwable;
34  
35      /**
36       * Construct thread control for a specific thread.
37       *
38       * @param thread the thread to control
39       */
40         protected DefaultThreadControl( final Thread   thread )
41         {
42             m_thread = thread;
43         }
44  
45      /**
46       * Wait for specified time for thread to complete it's work.
47       *
48       * @param milliSeconds the duration in milliseconds to wait until the thread has finished work
49       * @throws IllegalStateException if isValid() == false
50       * @throws InterruptedException if another thread has interrupted the current thread.
51       *            The interrupted status of the current thread is cleared when this exception
52       *            is thrown.
53       */
54         public synchronized void join( final long milliSeconds )
55                 throws IllegalStateException  , InterruptedException  
56         {
57          //final long start = System.currentTimeMillis();
58             wait( milliSeconds );
59          /*
60            if( !isFinished() )
61            {
62            final long now = System.currentTimeMillis();
63            if( start + milliSeconds > now )
64            {
65            final long remaining = milliSeconds - (now - start);
66            join( remaining );
67            }
68            }
69          */
70         }
71  
72      /**
73       * Call Thread.interrupt() on thread being controlled.
74       *
75       * @throws IllegalStateException if isValid() == false
76       * @throws SecurityException if caller does not have permission to call interupt()
77       */
78         public synchronized void interupt()
79                 throws IllegalStateException  , SecurityException  
80         {
81             if( !isFinished() )
82             {
83                 m_thread.interrupt();
84             }
85         }
86  
87      /**
88       * Determine if thread has finished execution
89       *
90       * @return true if thread is finished, false otherwise
91       */
92         public synchronized boolean isFinished()
93         {
94             return ( null == m_thread );
95         }
96  
97      /**
98       * Retrieve throwable that caused thread to cease execution.
99       * Only valid when true == isFinished()
100      *
101      * @return the throwable that caused thread to finish execution
102      */
103        public Throwable   getThrowable()
104        {
105            return m_throwable;
106        }
107 
108     /**
109      * Method called by thread to release control.
110      *
111      * @param throwable Throwable that caused thread to complete (may be null)
112      */
113        protected synchronized void finish( final Throwable   throwable )
114        {
115            m_thread = null;
116            m_throwable = throwable;
117            notifyAll();
118        }
119 }
120
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