bean/com/sun/star/comp/beans/CallWatchThread.java

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  30
  31 package com.sun.star.comp.beans;
  32
  33
  34 //---------------------------------------------------------------------------
  35 /** Helper class to watch calls into OOo with a timeout.
  36  */
  37 //Do not add the thread instances to a threadgroup. When testing the bean in
  38 //an applet it turned out the the ThreadGroup was in an inconsistent state
  39 //after navigating off the site that contains the applet and back to it.
  40 //That was tested with a Sun JRE 1.4.2_06
  41 public class CallWatchThread extends Thread
  42 {
  43     private static boolean DEBUG = false;
  44
  45     private Thread aWatchedThread;
  46     private String aTag;
  47     private boolean bAlive;
  48     private long nTimeout;
  49
  50     public CallWatchThread(long nTimeout)
  51     {
  52         this(nTimeout, "");
  53     }
  54
  55     public CallWatchThread( long nTimeout, String aTag )
  56     {
  57         super(aTag);
  58         this.aWatchedThread = Thread.currentThread();
  59         this.nTimeout = nTimeout;
  60
  61         this.aTag = aTag;
  62         setDaemon( true );
  63         dbgPrint( "CallWatchThread(" + this + ").start(" + aTag + ")" );
  64         start();
  65     }
  66
  67     public void cancel()
  68         throws java.lang.InterruptedException
  69     {
  70         dbgPrint( "CallWatchThread(" + this + ".cancel(" + aTag + ")" );
  71         if ( aWatchedThread != null && aWatchedThread != Thread.currentThread() )
  72             throw new RuntimeException( "wrong thread" );
  73         aWatchedThread = null;
  74         if ( interrupted() )
  75             throw new InterruptedException();
  76     }
  77
  78     public synchronized void restart()
  79         throws java.lang.InterruptedException
  80     {
  81         dbgPrint( "CallWatchThread(" + this + ".restart(" + aTag + ")" );
  82         if ( aWatchedThread != null && aWatchedThread != Thread.currentThread() )
  83             throw new RuntimeException( "wrong thread" );
  84         bAlive = true;
  85         if ( interrupted() )
  86             throw new InterruptedException();
  87         notify();
  88     }
  89
  90     public void run()
  91     {
  92         dbgPrint( "CallWatchThread(" + this + ".run(" + aTag + ") ***** STARTED *****" );
  93         long n = 0;
  94         while ( aWatchedThread != null )
  95         {
  96             dbgPrint( "CallWatchThread(" + this + ").run(" + aTag + ") running #" + ++n );
  97             synchronized(this)
  98             {
  99                 bAlive = false;
 100                 try
 101                 {
 102                     wait( nTimeout );
 103                 }
 104                 catch ( java.lang.InterruptedException aExc )
 105                 {
 106                     bAlive = false;
 107                 }
 108
 109                 // watched thread seems to be dead (not answering)?
 110                 if ( !bAlive && aWatchedThread != null )
 111                 {
 112                     dbgPrint( "CallWatchThread(" + this + ").run(" + aTag + ") interrupting" );
 113                     aWatchedThread.interrupt();
 114                     aWatchedThread = null;
 115                 }
 116             }
 117         }
 118
 119         dbgPrint( "CallWatchThread(" + this + ").run(" + aTag + ") terminated" );
 120     }
 121
 122     private void dbgPrint( String aMessage )
 123     {
 124         if (DEBUG)
 125             System.err.println( "OOoBean: " + aMessage );
 126     }
 127 }
 128
 129
 130
 131