1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
* Other contributors include Andrew Wright, Jeffrey Hayes,
* Pat Fisher, Mike Judd.
*/
import java.util.concurrent.atomic.AtomicStampedReference;
import junit.framework.Test;
import junit.framework.TestSuite;
public class AtomicStampedReferenceTest extends JSR166TestCase {
public static void main(String[] args) {
main(suite(), args);
}
public static Test suite() {
return new TestSuite(AtomicStampedReferenceTest.class);
}
/**
* constructor initializes to given reference and stamp
*/
public void testConstructor() {
AtomicStampedReference ai = new AtomicStampedReference(one, 0);
assertSame(one, ai.getReference());
assertEquals(0, ai.getStamp());
AtomicStampedReference a2 = new AtomicStampedReference(null, 1);
assertNull(a2.getReference());
assertEquals(1, a2.getStamp());
}
/**
* get returns the last values of reference and stamp set
*/
public void testGetSet() {
int[] mark = new int[1];
AtomicStampedReference ai = new AtomicStampedReference(one, 0);
assertSame(one, ai.getReference());
assertEquals(0, ai.getStamp());
assertSame(one, ai.get(mark));
assertEquals(0, mark[0]);
ai.set(two, 0);
assertSame(two, ai.getReference());
assertEquals(0, ai.getStamp());
assertSame(two, ai.get(mark));
assertEquals(0, mark[0]);
ai.set(one, 1);
assertSame(one, ai.getReference());
assertEquals(1, ai.getStamp());
assertSame(one, ai.get(mark));
assertEquals(1, mark[0]);
}
/**
* attemptStamp succeeds in single thread
*/
public void testAttemptStamp() {
int[] mark = new int[1];
AtomicStampedReference ai = new AtomicStampedReference(one, 0);
assertEquals(0, ai.getStamp());
assertTrue(ai.attemptStamp(one, 1));
assertEquals(1, ai.getStamp());
assertSame(one, ai.get(mark));
assertEquals(1, mark[0]);
}
/**
* compareAndSet succeeds in changing values if equal to expected reference
* and stamp else fails
*/
public void testCompareAndSet() {
int[] mark = new int[1];
AtomicStampedReference ai = new AtomicStampedReference(one, 0);
assertSame(one, ai.get(mark));
assertEquals(0, ai.getStamp());
assertEquals(0, mark[0]);
assertTrue(ai.compareAndSet(one, two, 0, 0));
assertSame(two, ai.get(mark));
assertEquals(0, mark[0]);
assertTrue(ai.compareAndSet(two, m3, 0, 1));
assertSame(m3, ai.get(mark));
assertEquals(1, mark[0]);
assertFalse(ai.compareAndSet(two, m3, 1, 1));
assertSame(m3, ai.get(mark));
assertEquals(1, mark[0]);
}
/**
* compareAndSet in one thread enables another waiting for reference value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
final AtomicStampedReference ai = new AtomicStampedReference(one, 0);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!ai.compareAndSet(two, three, 0, 0))
Thread.yield();
}});
t.start();
assertTrue(ai.compareAndSet(one, two, 0, 0));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertSame(three, ai.getReference());
assertEquals(0, ai.getStamp());
}
/**
* compareAndSet in one thread enables another waiting for stamp value
* to succeed
*/
public void testCompareAndSetInMultipleThreads2() throws Exception {
final AtomicStampedReference ai = new AtomicStampedReference(one, 0);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!ai.compareAndSet(one, one, 1, 2))
Thread.yield();
}});
t.start();
assertTrue(ai.compareAndSet(one, one, 0, 1));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertSame(one, ai.getReference());
assertEquals(2, ai.getStamp());
}
/**
* repeated weakCompareAndSet succeeds in changing values when equal
* to expected
*/
public void testWeakCompareAndSet() {
int[] mark = new int[1];
AtomicStampedReference ai = new AtomicStampedReference(one, 0);
assertSame(one, ai.get(mark));
assertEquals(0, ai.getStamp());
assertEquals(0, mark[0]);
do {} while (!ai.weakCompareAndSet(one, two, 0, 0));
assertSame(two, ai.get(mark));
assertEquals(0, mark[0]);
do {} while (!ai.weakCompareAndSet(two, m3, 0, 1));
assertSame(m3, ai.get(mark));
assertEquals(1, mark[0]);
}
}
|
