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
|
/*
* 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.AtomicReference;
import junit.framework.Test;
import junit.framework.TestSuite;
public class AtomicReferenceTest extends JSR166TestCase {
public static void main(String[] args) {
main(suite(), args);
}
public static Test suite() {
return new TestSuite(AtomicReferenceTest.class);
}
/**
* constructor initializes to given value
*/
public void testConstructor() {
AtomicReference ai = new AtomicReference(one);
assertSame(one, ai.get());
}
/**
* default constructed initializes to null
*/
public void testConstructor2() {
AtomicReference ai = new AtomicReference();
assertNull(ai.get());
}
/**
* get returns the last value set
*/
public void testGetSet() {
AtomicReference ai = new AtomicReference(one);
assertSame(one, ai.get());
ai.set(two);
assertSame(two, ai.get());
ai.set(m3);
assertSame(m3, ai.get());
}
/**
* get returns the last value lazySet in same thread
*/
public void testGetLazySet() {
AtomicReference ai = new AtomicReference(one);
assertSame(one, ai.get());
ai.lazySet(two);
assertSame(two, ai.get());
ai.lazySet(m3);
assertSame(m3, ai.get());
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicReference ai = new AtomicReference(one);
assertTrue(ai.compareAndSet(one, two));
assertTrue(ai.compareAndSet(two, m4));
assertSame(m4, ai.get());
assertFalse(ai.compareAndSet(m5, seven));
assertSame(m4, ai.get());
assertTrue(ai.compareAndSet(m4, seven));
assertSame(seven, ai.get());
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
final AtomicReference ai = new AtomicReference(one);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!ai.compareAndSet(two, three))
Thread.yield();
}});
t.start();
assertTrue(ai.compareAndSet(one, two));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertSame(three, ai.get());
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicReference ai = new AtomicReference(one);
do {} while (!ai.weakCompareAndSet(one, two));
do {} while (!ai.weakCompareAndSet(two, m4));
assertSame(m4, ai.get());
do {} while (!ai.weakCompareAndSet(m4, seven));
assertSame(seven, ai.get());
}
/**
* getAndSet returns previous value and sets to given value
*/
public void testGetAndSet() {
AtomicReference ai = new AtomicReference(one);
assertSame(one, ai.getAndSet(zero));
assertSame(zero, ai.getAndSet(m10));
assertSame(m10, ai.getAndSet(one));
}
/**
* a deserialized/reserialized atomic holds same value
*/
public void testSerialization() throws Exception {
AtomicReference x = new AtomicReference();
AtomicReference y = serialClone(x);
assertNotSame(x, y);
x.set(one);
AtomicReference z = serialClone(x);
assertNotSame(y, z);
assertEquals(one, x.get());
assertNull(y.get());
assertEquals(one, z.get());
}
/**
* toString returns current value.
*/
public void testToString() {
AtomicReference<Integer> ai = new AtomicReference<>(one);
assertEquals(one.toString(), ai.toString());
ai.set(two);
assertEquals(two.toString(), ai.toString());
}
}
|
