| 1 |
/* |
| 2 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
| 3 |
* Expert Group and released to the public domain, as explained at |
| 4 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
| 5 |
* Other contributors include Andrew Wright, Jeffrey Hayes, |
| 6 |
* Pat Fisher, Mike Judd. |
| 7 |
*/ |
| 8 |
|
| 9 |
import junit.framework.*; |
| 10 |
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater; |
| 11 |
|
| 12 |
public class AtomicReferenceFieldUpdaterTest extends JSR166TestCase { |
| 13 |
volatile Integer x = null; |
| 14 |
Object z; |
| 15 |
Integer w; |
| 16 |
volatile int i; |
| 17 |
|
| 18 |
public static void main(String[] args) { |
| 19 |
junit.textui.TestRunner.run(suite()); |
| 20 |
} |
| 21 |
public static Test suite() { |
| 22 |
return new TestSuite(AtomicReferenceFieldUpdaterTest.class); |
| 23 |
} |
| 24 |
|
| 25 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> updaterFor(String fieldName) { |
| 26 |
return AtomicReferenceFieldUpdater.newUpdater |
| 27 |
(AtomicReferenceFieldUpdaterTest.class, Integer.class, fieldName); |
| 28 |
} |
| 29 |
|
| 30 |
/** |
| 31 |
* Construction with non-existent field throws RuntimeException |
| 32 |
*/ |
| 33 |
public void testConstructor() { |
| 34 |
try { |
| 35 |
updaterFor("y"); |
| 36 |
shouldThrow(); |
| 37 |
} catch (RuntimeException success) { |
| 38 |
assertTrue(success.getCause() != null); |
| 39 |
} |
| 40 |
} |
| 41 |
|
| 42 |
/** |
| 43 |
* construction with field not of given type throws ClassCastException |
| 44 |
*/ |
| 45 |
public void testConstructor2() { |
| 46 |
try { |
| 47 |
updaterFor("z"); |
| 48 |
shouldThrow(); |
| 49 |
} catch (ClassCastException success) {} |
| 50 |
} |
| 51 |
|
| 52 |
/** |
| 53 |
* Constructor with non-volatile field throws IllegalArgumentException |
| 54 |
*/ |
| 55 |
public void testConstructor3() { |
| 56 |
try { |
| 57 |
updaterFor("w"); |
| 58 |
shouldThrow(); |
| 59 |
} catch (IllegalArgumentException success) {} |
| 60 |
} |
| 61 |
|
| 62 |
/** |
| 63 |
* Constructor with non-reference field throws ClassCastException |
| 64 |
*/ |
| 65 |
public void testConstructor4() { |
| 66 |
try { |
| 67 |
updaterFor("i"); |
| 68 |
shouldThrow(); |
| 69 |
} catch (ClassCastException success) {} |
| 70 |
} |
| 71 |
|
| 72 |
/** |
| 73 |
* get returns the last value set or assigned |
| 74 |
*/ |
| 75 |
public void testGetSet() { |
| 76 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 77 |
a = updaterFor("x"); |
| 78 |
x = one; |
| 79 |
assertSame(one, a.get(this)); |
| 80 |
a.set(this, two); |
| 81 |
assertSame(two, a.get(this)); |
| 82 |
a.set(this, m3); |
| 83 |
assertSame(m3, a.get(this)); |
| 84 |
} |
| 85 |
|
| 86 |
/** |
| 87 |
* get returns the last value lazySet by same thread |
| 88 |
*/ |
| 89 |
public void testGetLazySet() { |
| 90 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 91 |
a = updaterFor("x"); |
| 92 |
x = one; |
| 93 |
assertSame(one, a.get(this)); |
| 94 |
a.lazySet(this, two); |
| 95 |
assertSame(two, a.get(this)); |
| 96 |
a.lazySet(this, m3); |
| 97 |
assertSame(m3, a.get(this)); |
| 98 |
} |
| 99 |
|
| 100 |
/** |
| 101 |
* compareAndSet succeeds in changing value if equal to expected else fails |
| 102 |
*/ |
| 103 |
public void testCompareAndSet() { |
| 104 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 105 |
a = updaterFor("x"); |
| 106 |
x = one; |
| 107 |
assertTrue(a.compareAndSet(this, one, two)); |
| 108 |
assertTrue(a.compareAndSet(this, two, m4)); |
| 109 |
assertSame(m4, a.get(this)); |
| 110 |
assertFalse(a.compareAndSet(this, m5, seven)); |
| 111 |
assertFalse(seven == a.get(this)); |
| 112 |
assertTrue(a.compareAndSet(this, m4, seven)); |
| 113 |
assertSame(seven, a.get(this)); |
| 114 |
} |
| 115 |
|
| 116 |
/** |
| 117 |
* compareAndSet in one thread enables another waiting for value |
| 118 |
* to succeed |
| 119 |
*/ |
| 120 |
public void testCompareAndSetInMultipleThreads() throws Exception { |
| 121 |
x = one; |
| 122 |
final AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 123 |
a = updaterFor("x"); |
| 124 |
|
| 125 |
Thread t = new Thread(new CheckedRunnable() { |
| 126 |
public void realRun() { |
| 127 |
while (!a.compareAndSet(AtomicReferenceFieldUpdaterTest.this, two, three)) |
| 128 |
Thread.yield(); |
| 129 |
}}); |
| 130 |
|
| 131 |
t.start(); |
| 132 |
assertTrue(a.compareAndSet(this, one, two)); |
| 133 |
t.join(LONG_DELAY_MS); |
| 134 |
assertFalse(t.isAlive()); |
| 135 |
assertSame(three, a.get(this)); |
| 136 |
} |
| 137 |
|
| 138 |
/** |
| 139 |
* repeated weakCompareAndSet succeeds in changing value when equal |
| 140 |
* to expected |
| 141 |
*/ |
| 142 |
public void testWeakCompareAndSet() { |
| 143 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 144 |
a = updaterFor("x"); |
| 145 |
x = one; |
| 146 |
while (!a.weakCompareAndSet(this, one, two)); |
| 147 |
while (!a.weakCompareAndSet(this, two, m4)); |
| 148 |
assertSame(m4, a.get(this)); |
| 149 |
while (!a.weakCompareAndSet(this, m4, seven)); |
| 150 |
assertSame(seven, a.get(this)); |
| 151 |
} |
| 152 |
|
| 153 |
/** |
| 154 |
* getAndSet returns previous value and sets to given value |
| 155 |
*/ |
| 156 |
public void testGetAndSet() { |
| 157 |
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a; |
| 158 |
a = updaterFor("x"); |
| 159 |
x = one; |
| 160 |
assertSame(one, a.getAndSet(this, zero)); |
| 161 |
assertSame(zero, a.getAndSet(this, m10)); |
| 162 |
assertSame(m10, a.getAndSet(this, 1)); |
| 163 |
} |
| 164 |
|
| 165 |
} |
