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Java > Open Source Codes > org > apache > geronimo > connector > work > pool > TimedOutPooledExecutor


1 /**
2  *
3  * Copyright 2003-2004 The Apache Software Foundation
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 package org.apache.geronimo.connector.work.pool;
19
20 import EDU.oswego.cs.dl.util.concurrent.Channel;
21 import EDU.oswego.cs.dl.util.concurrent.PooledExecutor;
22 import org.apache.geronimo.connector.work.WorkerContext;
23
24 /**
25  * PooledExecutor enforcing a timed out "blocked execution policy". The works
26  * submitted to this pooled executor MUST be a WorkWrapper.
27  *
28  * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
29  */
30 public class TimedOutPooledExecutor extends PooledExecutor {
31
32     /**
33      * Creates a pooled executor. The Channel used to enqueue the submitted
34      * Work instance is a queueless synchronous one.
35      */
36     public TimedOutPooledExecutor() {
37         setBlockedExecutionHandler(new TimedOutSpinHandler());
38     }
39
40     /**
41      * Creates a pooled executor, which uses the provided Channel as its
42      * queueing mechanism.
43      *
44      * @param aChannel Channel to be used to enqueue the submitted Work
45      * intances.
46      */
47     public TimedOutPooledExecutor(Channel aChannel) {
48         super(aChannel);
49         setBlockedExecutionHandler(new TimedOutSpinHandler());
50     }
51
52     /**
53      * Executes the provided task, which MUST be an instance of WorkWrapper.
54      *
55      * @throws IllegalArgumentException Indicates that the provided task is not
56      * a WorkWrapper instance.
57      */
58     public void execute(Runnable JavaDoc aTask) throws InterruptedException JavaDoc {
59         if (!(aTask instanceof WorkerContext)) {
60             throw new IllegalArgumentException JavaDoc("Please submit a WorkWrapper.");
61         }
62         super.execute(aTask);
63     }
64
65     /**
66      * This class implements a time out policy when a work is blocked: it offers
67      * the task to the pool until the work has timed out.
68      *
69      * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
70      */
71     private class TimedOutSpinHandler
72             implements PooledExecutor.BlockedExecutionHandler {
73
74         /* (non-Javadoc)
75          * @see EDU.oswego.cs.dl.util.concurrent.PooledExecutor.BlockedExecutionHandler#blockedAction(java.lang.Runnable)
76          */
77         public boolean blockedAction(Runnable JavaDoc arg0) throws InterruptedException JavaDoc {
78             WorkerContext work = (WorkerContext) arg0;
79             if (!handOff_.offer(arg0, work.getStartTimeout())) {
80                 // double check.
81 if (work.isTimedOut()) {
82                     return false;
83                 }
84                 return true;
85             }
86             return true;
87         }
88     }
89 }
90
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