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Java > Open Source Codes > org > apache > commons > pool > impl > FairGenericObjectPoolTest


1 /* FairGenericObjectPoolTest
2 *
3 * $Id: FairGenericObjectPoolTest.java,v 1.2.6.1 2007/01/13 01:31:05 stack-sf Exp $
4 *
5 * Created on Apr 7, 2006
6 *
7 * Copyright (C) 2006 Internet Archive.
8 *
9 */
10 package org.apache.commons.pool.impl;
11
12 import java.util.Arrays JavaDoc;
13 import java.util.Collections JavaDoc;
14 import java.util.LinkedList JavaDoc;
15 import java.util.List JavaDoc;
16
17 import junit.framework.TestCase;
18
19 import org.apache.commons.pool.BasePoolableObjectFactory;
20
21 /**
22  * Test for FairGenericObjectPool.
23  *
24  * @author gojomo
25  */
26 @SuppressWarnings JavaDoc("unchecked")
27 public class FairGenericObjectPoolTest extends TestCase {
28 // public void testUnfair() throws InterruptedException {
29 //// System.out.println("unfair");
30 // GenericObjectPool pool = new GenericObjectPool();
31 //
32 // Object[] borrowOrder = tryPool(pool);
33 //
34 // Object[] sortedOrder = (Object[]) borrowOrder.clone();
35 // Arrays.sort(sortedOrder);
36 // assertFalse("unexpectedly fair", Arrays.equals(borrowOrder,sortedOrder));
37 // }
38
39     public void testFair() throws InterruptedException JavaDoc {
40 // System.out.println("fair");
41 GenericObjectPool pool = new FairGenericObjectPool();
42         
43         Object JavaDoc[] borrowOrder = tryPool(pool);
44         
45         Object JavaDoc[] sortedOrder = (Object JavaDoc[]) borrowOrder.clone();
46         Arrays.sort(sortedOrder);
47         assertTrue("unexpectedly unfair", Arrays.equals(borrowOrder,sortedOrder));
48     }
49     
50     /**
51      * Test the given pool for fairness.
52      *
53      * @param pool GenericObjectPool to test
54      * @throws InterruptedException
55      */
56     private Object JavaDoc[] tryPool(GenericObjectPool pool) throws InterruptedException JavaDoc {
57         BlockerObjectFactory factory = new BlockerObjectFactory();
58         pool.setFactory(factory);
59         pool.setMaxActive(1);
60         List JavaDoc borrowOrder = Collections.synchronizedList(new LinkedList JavaDoc());
61         for(int i = 0; i < 10; i++) {
62             Contender c = new Contender(borrowOrder);
63             c.pool = pool;
64             c.ordinal = i;
65             (new Thread JavaDoc(c)).start();
66             Thread.sleep(500);
67         }
68         factory.single.release();
69         Thread.sleep(5000);
70         return borrowOrder.toArray();
71     }
72
73     class Contender implements Runnable JavaDoc {
74         public GenericObjectPool pool;
75         public int ordinal;
76         public List JavaDoc reportList;
77         
78         public Contender(List JavaDoc borrowOrder) {
79             reportList = borrowOrder;
80         }
81
82         public void run() {
83             try {
84                 Blocker block = (Blocker) pool.borrowObject();
85                 System.out.println("borrowed #"+ordinal);
86                 reportList.add(new Integer JavaDoc(ordinal));
87                 block.acquire();
88                 System.out.println("returning #"+ordinal);
89                 pool.returnObject(block);
90             } catch (Exception JavaDoc e) {
91                 throw new RuntimeException JavaDoc(e);
92             }
93         }
94         
95     }
96     
97     class BlockerObjectFactory extends BasePoolableObjectFactory {
98         public Blocker single = new Blocker();
99         public Object JavaDoc makeObject() throws Exception JavaDoc {
100             System.out.println("makeObject");
101             return single;
102         }
103     }
104     
105     class Blocker {
106         boolean block = true;
107         public synchronized void acquire() {
108             // only block first time through
109 if(block) {
110                 try {
111                     wait();
112                 } catch (InterruptedException JavaDoc e) {
113                     throw new RuntimeException JavaDoc(e);
114                 }
115             }
116             block = false;
117         }
118         public synchronized void release() {
119             notifyAll();
120         }
121     }
122 }
123
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