/** addAndGet adds given value to current, and returns current value */
public void testAddAndGet() {
AtomicLong ai = new AtomicLong(1);
assertEquals(3, ai.addAndGet(2));
assertEquals(3, ai.get());
assertEquals(-1, ai.addAndGet(-4));
assertEquals(-1, ai.get());
}
/** getAndAdd returns previous value and adds given value */
public void testGetAndAdd() {
AtomicLong ai = new AtomicLong(1);
assertEquals(1, ai.getAndAdd(2));
assertEquals(3, ai.get());
assertEquals(3, ai.getAndAdd(-4));
assertEquals(-1, ai.get());
}
/** repeated weakCompareAndSet succeeds in changing value when equal to expected */
public void testWeakCompareAndSet() {
AtomicLong ai = new AtomicLong(1);
while (!ai.weakCompareAndSet(1, 2)) ;
while (!ai.weakCompareAndSet(2, -4)) ;
assertEquals(-4, ai.get());
while (!ai.weakCompareAndSet(-4, 7)) ;
assertEquals(7, ai.get());
}
/** get returns the last value lazySet in same thread */
public void testGetLazySet() {
AtomicLong ai = new AtomicLong(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() {
AtomicLong ai = new AtomicLong(1);
assertTrue(ai.compareAndSet(1, 2));
assertTrue(ai.compareAndSet(2, -4));
assertEquals(-4, ai.get());
assertFalse(ai.compareAndSet(-5, 7));
assertFalse((7 == ai.get()));
assertTrue(ai.compareAndSet(-4, 7));
assertEquals(7, ai.get());
}
/** incrementAndGet increments and returns current value */
public void testIncrementAndGet() {
AtomicLong ai = new AtomicLong(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());
}
/** decrementAndGet decrements and returns current value */
public void testDecrementAndGet() {
AtomicLong ai = new AtomicLong(1);
assertEquals(0, ai.decrementAndGet());
assertEquals(-1, ai.decrementAndGet());
assertEquals(-2, ai.decrementAndGet());
assertEquals(-2, ai.get());
}
/** a deserialized serialized atomic holds same value */
public void testSerialization() {
AtomicLong l = new AtomicLong();
try {
l.set(-22);
ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
out.writeObject(l);
out.close();
ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
AtomicLong r = (AtomicLong) in.readObject();
assertEquals(l.get(), r.get());
} catch (Exception e) {
unexpectedException();
}
}
/** compareAndSet in one thread enables another waiting for value to succeed */
public void testCompareAndSetInMultipleThreads() {
final AtomicLong ai = new AtomicLong(1);
Thread t =
new Thread(
new Runnable() {
public void run() {
while (!ai.compareAndSet(2, 3)) Thread.yield();
}
});
try {
t.start();
assertTrue(ai.compareAndSet(1, 2));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertEquals(ai.get(), 3);
} catch (Exception e) {
unexpectedException();
}
}
/** default constructed initializes to zero */
public void testConstructor2() {
AtomicLong ai = new AtomicLong();
assertEquals(0, ai.get());
}