| 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/licenses/publicdomain |
| 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.*; |
| 11 |
import java.io.*; |
| 12 |
|
| 13 |
public class AtomicReferenceTest extends JSR166TestCase { |
| 14 |
public static void main (String[] args) { |
| 15 |
junit.textui.TestRunner.run (suite()); |
| 16 |
} |
| 17 |
public static Test suite() { |
| 18 |
return new TestSuite(AtomicReferenceTest.class); |
| 19 |
} |
| 20 |
|
| 21 |
/** |
| 22 |
* constructor initializes to given value |
| 23 |
*/ |
| 24 |
public void testConstructor(){ |
| 25 |
AtomicReference ai = new AtomicReference(one); |
| 26 |
assertEquals(one,ai.get()); |
| 27 |
} |
| 28 |
|
| 29 |
/** |
| 30 |
* default constructed initializes to null |
| 31 |
*/ |
| 32 |
public void testConstructor2(){ |
| 33 |
AtomicReference ai = new AtomicReference(); |
| 34 |
assertNull(ai.get()); |
| 35 |
} |
| 36 |
|
| 37 |
/** |
| 38 |
* get returns the last value set |
| 39 |
*/ |
| 40 |
public void testGetSet(){ |
| 41 |
AtomicReference ai = new AtomicReference(one); |
| 42 |
assertEquals(one,ai.get()); |
| 43 |
ai.set(two); |
| 44 |
assertEquals(two,ai.get()); |
| 45 |
ai.set(m3); |
| 46 |
assertEquals(m3,ai.get()); |
| 47 |
|
| 48 |
} |
| 49 |
/** |
| 50 |
* compareAndSet succeeds in changing value if equal to expected else fails |
| 51 |
*/ |
| 52 |
public void testCompareAndSet(){ |
| 53 |
AtomicReference ai = new AtomicReference(one); |
| 54 |
assertTrue(ai.compareAndSet(one,two)); |
| 55 |
assertTrue(ai.compareAndSet(two,m4)); |
| 56 |
assertEquals(m4,ai.get()); |
| 57 |
assertFalse(ai.compareAndSet(m5,seven)); |
| 58 |
assertFalse((seven.equals(ai.get()))); |
| 59 |
assertTrue(ai.compareAndSet(m4,seven)); |
| 60 |
assertEquals(seven,ai.get()); |
| 61 |
} |
| 62 |
|
| 63 |
/** |
| 64 |
* compareAndSet in one thread enables another waiting for value |
| 65 |
* to succeed |
| 66 |
*/ |
| 67 |
public void testCompareAndSetInMultipleThreads() { |
| 68 |
final AtomicReference ai = new AtomicReference(one); |
| 69 |
Thread t = new Thread(new Runnable() { |
| 70 |
public void run() { |
| 71 |
while(!ai.compareAndSet(two, three)) Thread.yield(); |
| 72 |
}}); |
| 73 |
try { |
| 74 |
t.start(); |
| 75 |
assertTrue(ai.compareAndSet(one, two)); |
| 76 |
t.join(LONG_DELAY_MS); |
| 77 |
assertFalse(t.isAlive()); |
| 78 |
assertEquals(ai.get(), three); |
| 79 |
} |
| 80 |
catch(Exception e) { |
| 81 |
unexpectedException(); |
| 82 |
} |
| 83 |
} |
| 84 |
|
| 85 |
/** |
| 86 |
* repeated weakCompareAndSet succeeds in changing value when equal |
| 87 |
* to expected |
| 88 |
*/ |
| 89 |
public void testWeakCompareAndSet(){ |
| 90 |
AtomicReference ai = new AtomicReference(one); |
| 91 |
while(!ai.weakCompareAndSet(one,two)); |
| 92 |
while(!ai.weakCompareAndSet(two,m4)); |
| 93 |
assertEquals(m4,ai.get()); |
| 94 |
while(!ai.weakCompareAndSet(m4,seven)); |
| 95 |
assertEquals(seven,ai.get()); |
| 96 |
} |
| 97 |
|
| 98 |
/** |
| 99 |
* getAndSet returns previous value and sets to given value |
| 100 |
*/ |
| 101 |
public void testGetAndSet(){ |
| 102 |
AtomicReference ai = new AtomicReference(one); |
| 103 |
assertEquals(one,ai.getAndSet(zero)); |
| 104 |
assertEquals(zero,ai.getAndSet(m10)); |
| 105 |
assertEquals(m10,ai.getAndSet(one)); |
| 106 |
} |
| 107 |
|
| 108 |
/** |
| 109 |
* a deserialized serialized atomic holds same value |
| 110 |
*/ |
| 111 |
public void testSerialization() { |
| 112 |
AtomicReference l = new AtomicReference(); |
| 113 |
|
| 114 |
try { |
| 115 |
l.set(one); |
| 116 |
ByteArrayOutputStream bout = new ByteArrayOutputStream(10000); |
| 117 |
ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout)); |
| 118 |
out.writeObject(l); |
| 119 |
out.close(); |
| 120 |
|
| 121 |
ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray()); |
| 122 |
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); |
| 123 |
AtomicReference r = (AtomicReference) in.readObject(); |
| 124 |
assertEquals(l.get(), r.get()); |
| 125 |
} catch(Exception e){ |
| 126 |
unexpectedException(); |
| 127 |
} |
| 128 |
} |
| 129 |
|
| 130 |
/** |
| 131 |
* toString returns current value. |
| 132 |
*/ |
| 133 |
public void testToString() { |
| 134 |
AtomicReference<Integer> ai = new AtomicReference<Integer>(one); |
| 135 |
assertEquals(ai.toString(), one.toString()); |
| 136 |
ai.set(two); |
| 137 |
assertEquals(ai.toString(), two.toString()); |
| 138 |
} |
| 139 |
|
| 140 |
} |
| 141 |
|
