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/*
* 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.
*/
package jsr166;
import junit.framework.*;
import java.util.concurrent.atomic.AtomicInteger;
public class AtomicIntegerTest extends JSR166TestCase {
final int[] VALUES = {
Integer.MIN_VALUE, -1, 0, 1, 42, Integer.MAX_VALUE,
};
/**
* constructor initializes to given value
*/
public void testConstructor() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.get());
}
/**
* default constructed initializes to zero
*/
public void testConstructor2() {
AtomicInteger ai = new AtomicInteger();
assertEquals(0, ai.get());
}
/**
* get returns the last value set
*/
public void testGetSet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.get());
ai.set(2);
assertEquals(2, ai.get());
ai.set(-3);
assertEquals(-3, ai.get());
}
/**
* get returns the last value lazySet in same thread
*/
public void testGetLazySet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.get());
ai.lazySet(2);
assertEquals(2, ai.get());
ai.lazySet(-3);
assertEquals(-3, ai.get());
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicInteger ai = new AtomicInteger(1);
assertTrue(ai.compareAndSet(1, 2));
assertTrue(ai.compareAndSet(2, -4));
assertEquals(-4, ai.get());
assertFalse(ai.compareAndSet(-5, 7));
assertEquals(-4, ai.get());
assertTrue(ai.compareAndSet(-4, 7));
assertEquals(7, ai.get());
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
final AtomicInteger ai = new AtomicInteger(1);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!ai.compareAndSet(2, 3))
Thread.yield();
}});
t.start();
assertTrue(ai.compareAndSet(1, 2));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertEquals(3, ai.get());
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicInteger ai = new AtomicInteger(1);
while (!ai.weakCompareAndSet(1, 2));
while (!ai.weakCompareAndSet(2, -4));
assertEquals(-4, ai.get());
while (!ai.weakCompareAndSet(-4, 7));
assertEquals(7, ai.get());
}
/**
* getAndSet returns previous value and sets to given value
*/
public void testGetAndSet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.getAndSet(0));
assertEquals(0, ai.getAndSet(-10));
assertEquals(-10, ai.getAndSet(1));
}
/**
* getAndAdd returns previous value and adds given value
*/
public void testGetAndAdd() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.getAndAdd(2));
assertEquals(3, ai.get());
assertEquals(3, ai.getAndAdd(-4));
assertEquals(-1, ai.get());
}
/**
* getAndDecrement returns previous value and decrements
*/
public void testGetAndDecrement() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.getAndDecrement());
assertEquals(0, ai.getAndDecrement());
assertEquals(-1, ai.getAndDecrement());
}
/**
* getAndIncrement returns previous value and increments
*/
public void testGetAndIncrement() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(1, ai.getAndIncrement());
assertEquals(2, ai.get());
ai.set(-2);
assertEquals(-2, ai.getAndIncrement());
assertEquals(-1, ai.getAndIncrement());
assertEquals(0, ai.getAndIncrement());
assertEquals(1, ai.get());
}
/**
* addAndGet adds given value to current, and returns current value
*/
public void testAddAndGet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(3, ai.addAndGet(2));
assertEquals(3, ai.get());
assertEquals(-1, ai.addAndGet(-4));
assertEquals(-1, ai.get());
}
/**
* decrementAndGet decrements and returns current value
*/
public void testDecrementAndGet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(0, ai.decrementAndGet());
assertEquals(-1, ai.decrementAndGet());
assertEquals(-2, ai.decrementAndGet());
assertEquals(-2, ai.get());
}
/**
* incrementAndGet increments and returns current value
*/
public void testIncrementAndGet() {
AtomicInteger ai = new AtomicInteger(1);
assertEquals(2, ai.incrementAndGet());
assertEquals(2, ai.get());
ai.set(-2);
assertEquals(-1, ai.incrementAndGet());
assertEquals(0, ai.incrementAndGet());
assertEquals(1, ai.incrementAndGet());
assertEquals(1, ai.get());
}
/**
* a deserialized serialized atomic holds same value
*/
public void testSerialization() throws Exception {
AtomicInteger x = new AtomicInteger();
AtomicInteger y = serialClone(x);
assertNotSame(x, y);
x.set(22);
AtomicInteger z = serialClone(x);
assertEquals(22, x.get());
assertEquals(0, y.get());
assertEquals(22, z.get());
}
/**
* toString returns current value.
*/
public void testToString() {
AtomicInteger ai = new AtomicInteger();
assertEquals("0", ai.toString());
for (int x : VALUES) {
ai.set(x);
assertEquals(Integer.toString(x), ai.toString());
}
}
/**
* intValue returns current value.
*/
public void testIntValue() {
AtomicInteger ai = new AtomicInteger();
assertEquals(0, ai.intValue());
for (int x : VALUES) {
ai.set(x);
assertEquals(x, ai.intValue());
}
}
/**
* longValue returns current value.
*/
public void testLongValue() {
AtomicInteger ai = new AtomicInteger();
assertEquals(0L, ai.longValue());
for (int x : VALUES) {
ai.set(x);
assertEquals((long)x, ai.longValue());
}
}
/**
* floatValue returns current value.
*/
public void testFloatValue() {
AtomicInteger ai = new AtomicInteger();
assertEquals(0.0f, ai.floatValue());
for (int x : VALUES) {
ai.set(x);
assertEquals((float)x, ai.floatValue());
}
}
/**
* doubleValue returns current value.
*/
public void testDoubleValue() {
AtomicInteger ai = new AtomicInteger();
assertEquals(0.0d, ai.doubleValue());
for (int x : VALUES) {
ai.set(x);
assertEquals((double)x, ai.doubleValue());
}
}
}
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