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1   /*
2    * Copyright 2000-2004 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.jetspeed.daemon.impl.util;
18  
19  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
20  import org.apache.jetspeed.services.logging.JetspeedLogger;
21  
22  /***
23  Util class for joining a ThreadGroup and joining all of its Threads and waiting
24  for completion.
25  
26  @author <A HREF="mailto:burton@apache.org">Kevin A. Burton</A>
27  @version $Id: ThreadGroupJoin.java,v 1.10 2004/02/23 02:47:43 jford Exp $
28  */
29  public class ThreadGroupJoin 
30  {    
31      /***
32       * Static initialization of the logger for this class
33       */
34      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(ThreadGroupJoin.class.getName());
35      
36      /***
37      Join a ThreadGroup and wait until it finishes
38      */
39      public static void join( ThreadGroup tg ) 
40      {
41          //join the threadgroup but don't have a source.
42          join( tg, null, 0 );
43      }
44  
45      /***
46      Join a ThreadGroup bug specify a source and use a default interval.
47      */
48      public static void join( ThreadGroup tg,
49                               String source ) 
50      {
51          join( tg, source, 100 );
52      }
53      
54      /***
55      Join a ThreadGroup except also log when interval number of Threads have 
56      finished.
57      */
58      public static void join( ThreadGroup tg, 
59                               String source, 
60                               int interval ) 
61      {
62  
63          Thread[] threads = new Thread[ tg.activeCount() ];
64          
65          tg.enumerate( threads );
66  
67          //keep waiting until all the DownloadThreads have stopped.
68  
69          long begin = System.currentTimeMillis();        
70          
71          for ( int i = 0; i < threads.length; ++i ) {
72  
73              if ( !threads[i].interrupted() ) 
74              {
75                  try 
76                  {
77                      if ( threads[i] != null ) 
78                      {
79                          threads[i].join();
80                          
81                          //if this is an even MOD of this interval and a source
82                          //is defined then log it
83                          if ( i != 0 && 
84                              i % interval == 0 && 
85                              source != null ) 
86                          {
87                              long seconds = ( System.currentTimeMillis() - begin ) / 1000;
88                              begin = System.currentTimeMillis();
89                              
90                              if ( logger.isInfoEnabled() )
91                              {
92                                  logger.info( source + ": has completed " + i + " threads in " + seconds + " second(s)" );
93                              }
94                              
95                          }
96                          
97                      }
98  
99                  } 
100                 catch (InterruptedException e) 
101                 {
102                     logger.info( "Thread: " + threads[i].getName() + " -> DONE");
103                     //noop.  this is standard.
104                 }
105            }
106 
107         }
108         
109         
110     }
111     
112 }
113     
114