/*
* 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 java.util.Arrays;
import java.util.concurrent.atomic.AtomicIntegerArray;
import junit.framework.Test;
import junit.framework.TestSuite;
public class AtomicIntegerArrayTest extends JSR166TestCase {
// android-note: Removed because the CTS runner does a bad job of
// retrying tests that have suite() declarations.
//
// public static void main(String[] args) {
// main(suite(), args);
// }
// public static Test suite() {
// return new TestSuite(...);
// }
/**
* constructor creates array of given size with all elements zero
*/
public void testConstructor() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++)
assertEquals(0, aa.get(i));
}
/**
* constructor with null array throws NPE
*/
public void testConstructor2NPE() {
try {
int[] a = null;
new AtomicIntegerArray(a);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* constructor with array is of same size and has all elements
*/
public void testConstructor2() {
int[] a = { 17, 3, -42, 99, -7 };
AtomicIntegerArray aa = new AtomicIntegerArray(a);
assertEquals(a.length, aa.length());
for (int i = 0; i < a.length; i++)
assertEquals(a[i], aa.get(i));
}
/**
* get and set for out of bound indices throw IndexOutOfBoundsException
*/
public void testIndexing() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int index : new int[] { -1, SIZE }) {
try {
aa.get(index);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.set(index, 1);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.lazySet(index, 1);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.compareAndSet(index, 1, 2);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.weakCompareAndSet(index, 1, 2);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.getAndAdd(index, 1);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.addAndGet(index, 1);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
}
}
/**
* get returns the last value set at index
*/
public void testGetSet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(1, aa.get(i));
aa.set(i, 2);
assertEquals(2, aa.get(i));
aa.set(i, -3);
assertEquals(-3, aa.get(i));
}
}
/**
* get returns the last value lazySet at index by same thread
*/
public void testGetLazySet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.lazySet(i, 1);
assertEquals(1, aa.get(i));
aa.lazySet(i, 2);
assertEquals(2, aa.get(i));
aa.lazySet(i, -3);
assertEquals(-3, aa.get(i));
}
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertTrue(aa.compareAndSet(i, 1, 2));
assertTrue(aa.compareAndSet(i, 2, -4));
assertEquals(-4, aa.get(i));
assertFalse(aa.compareAndSet(i, -5, 7));
assertEquals(-4, aa.get(i));
assertTrue(aa.compareAndSet(i, -4, 7));
assertEquals(7, aa.get(i));
}
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
final AtomicIntegerArray a = new AtomicIntegerArray(1);
a.set(0, 1);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!a.compareAndSet(0, 2, 3))
Thread.yield();
}});
t.start();
assertTrue(a.compareAndSet(0, 1, 2));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertEquals(3, a.get(0));
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
do {} while (!aa.weakCompareAndSet(i, 1, 2));
do {} while (!aa.weakCompareAndSet(i, 2, -4));
assertEquals(-4, aa.get(i));
do {} while (!aa.weakCompareAndSet(i, -4, 7));
assertEquals(7, aa.get(i));
}
}
/**
* getAndSet returns previous value and sets to given value at given index
*/
public void testGetAndSet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(1, aa.getAndSet(i, 0));
assertEquals(0, aa.getAndSet(i, -10));
assertEquals(-10, aa.getAndSet(i, 1));
}
}
/**
* getAndAdd returns previous value and adds given value
*/
public void testGetAndAdd() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(1, aa.getAndAdd(i, 2));
assertEquals(3, aa.get(i));
assertEquals(3, aa.getAndAdd(i, -4));
assertEquals(-1, aa.get(i));
}
}
/**
* getAndDecrement returns previous value and decrements
*/
public void testGetAndDecrement() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(1, aa.getAndDecrement(i));
assertEquals(0, aa.getAndDecrement(i));
assertEquals(-1, aa.getAndDecrement(i));
}
}
/**
* getAndIncrement returns previous value and increments
*/
public void testGetAndIncrement() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(1, aa.getAndIncrement(i));
assertEquals(2, aa.get(i));
aa.set(i, -2);
assertEquals(-2, aa.getAndIncrement(i));
assertEquals(-1, aa.getAndIncrement(i));
assertEquals(0, aa.getAndIncrement(i));
assertEquals(1, aa.get(i));
}
}
/**
* addAndGet adds given value to current, and returns current value
*/
public void testAddAndGet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(3, aa.addAndGet(i, 2));
assertEquals(3, aa.get(i));
assertEquals(-1, aa.addAndGet(i, -4));
assertEquals(-1, aa.get(i));
}
}
/**
* decrementAndGet decrements and returns current value
*/
public void testDecrementAndGet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(0, aa.decrementAndGet(i));
assertEquals(-1, aa.decrementAndGet(i));
assertEquals(-2, aa.decrementAndGet(i));
assertEquals(-2, aa.get(i));
}
}
/**
* incrementAndGet increments and returns current value
*/
public void testIncrementAndGet() {
AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, 1);
assertEquals(2, aa.incrementAndGet(i));
assertEquals(2, aa.get(i));
aa.set(i, -2);
assertEquals(-1, aa.incrementAndGet(i));
assertEquals(0, aa.incrementAndGet(i));
assertEquals(1, aa.incrementAndGet(i));
assertEquals(1, aa.get(i));
}
}
class Counter extends CheckedRunnable {
final AtomicIntegerArray aa;
volatile int counts;
Counter(AtomicIntegerArray a) { aa = a; }
public void realRun() {
for (;;) {
boolean done = true;
for (int i = 0; i < aa.length(); i++) {
int v = aa.get(i);
assertTrue(v >= 0);
if (v != 0) {
done = false;
if (aa.compareAndSet(i, v, v-1))
++counts;
}
}
if (done)
break;
}
}
}
/**
* Multiple threads using same array of counters successfully
* update a number of times equal to total count
*/
public void testCountingInMultipleThreads() throws InterruptedException {
final AtomicIntegerArray aa = new AtomicIntegerArray(SIZE);
int countdown = 10000;
for (int i = 0; i < SIZE; i++)
aa.set(i, countdown);
Counter c1 = new Counter(aa);
Counter c2 = new Counter(aa);
Thread t1 = new Thread(c1);
Thread t2 = new Thread(c2);
t1.start();
t2.start();
t1.join();
t2.join();
assertEquals(c1.counts+c2.counts, SIZE * countdown);
}
/**
* a deserialized serialized array holds same values
*/
public void testSerialization() throws Exception {
AtomicIntegerArray x = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; i++)
x.set(i, -i);
AtomicIntegerArray y = serialClone(x);
assertNotSame(x, y);
assertEquals(x.length(), y.length());
for (int i = 0; i < SIZE; i++) {
assertEquals(x.get(i), y.get(i));
}
}
/**
* toString returns current value.
*/
public void testToString() {
int[] a = { 17, 3, -42, 99, -7 };
AtomicIntegerArray aa = new AtomicIntegerArray(a);
assertEquals(Arrays.toString(a), aa.toString());
}
}