/*
* 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/licenses/publicdomain
* Other contributors include Andrew Wright, Jeffrey Hayes,
* Pat Fisher, Mike Judd.
*/
import junit.framework.*;
import java.util.concurrent.atomic.*;
import java.io.*;
import java.util.*;
public class AtomicIntegerArrayTest extends JSR166TestCase {
public static void main (String[] args) {
junit.textui.TestRunner.run (suite());
}
public static Test suite() {
return new TestSuite(AtomicIntegerArrayTest.class);
}
/**
* constructor creates array of given size with all elements zero
*/
public void testConstructor() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i)
assertEquals(0,ai.get(i));
}
/**
* constructor with null array throws NPE
*/
public void testConstructor2NPE() {
try {
int[] a = null;
AtomicIntegerArray ai = new AtomicIntegerArray(a);
} catch (NullPointerException success) {
} catch (Exception ex) {
unexpectedException();
}
}
/**
* constructor with array is of same size and has all elements
*/
public void testConstructor2() {
int[] a = { 17, 3, -42, 99, -7};
AtomicIntegerArray ai = new AtomicIntegerArray(a);
assertEquals(a.length, ai.length());
for (int i = 0; i < a.length; ++i)
assertEquals(a[i], ai.get(i));
}
/**
* get and set for out of bound indices throw IndexOutOfBoundsException
*/
public void testIndexing(){
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
try {
ai.get(SIZE);
} catch(IndexOutOfBoundsException success){
}
try {
ai.get(-1);
} catch(IndexOutOfBoundsException success){
}
try {
ai.set(SIZE, 0);
} catch(IndexOutOfBoundsException success){
}
try {
ai.set(-1, 0);
} catch(IndexOutOfBoundsException success){
}
}
/**
* get returns the last value set at index
*/
public void testGetSet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(1,ai.get(i));
ai.set(i, 2);
assertEquals(2,ai.get(i));
ai.set(i, -3);
assertEquals(-3,ai.get(i));
}
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertTrue(ai.compareAndSet(i, 1,2));
assertTrue(ai.compareAndSet(i, 2,-4));
assertEquals(-4,ai.get(i));
assertFalse(ai.compareAndSet(i, -5,7));
assertFalse((7 == ai.get(i)));
assertTrue(ai.compareAndSet(i, -4,7));
assertEquals(7,ai.get(i));
}
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() {
final AtomicIntegerArray a = new AtomicIntegerArray(1);
a.set(0, 1);
Thread t = new Thread(new Runnable() {
public void run() {
while(!a.compareAndSet(0, 2, 3)) Thread.yield();
}});
try {
t.start();
assertTrue(a.compareAndSet(0, 1, 2));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertEquals(a.get(0), 3);
}
catch(Exception e) {
unexpectedException();
}
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
while(!ai.weakCompareAndSet(i, 1,2));
while(!ai.weakCompareAndSet(i, 2,-4));
assertEquals(-4,ai.get(i));
while(!ai.weakCompareAndSet(i, -4,7));
assertEquals(7,ai.get(i));
}
}
/**
* getAndSet returns previous value and sets to given value at given index
*/
public void testGetAndSet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(1,ai.getAndSet(i,0));
assertEquals(0,ai.getAndSet(i,-10));
assertEquals(-10,ai.getAndSet(i,1));
}
}
/**
* getAndAdd returns previous value and adds given value
*/
public void testGetAndAdd() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(1,ai.getAndAdd(i,2));
assertEquals(3,ai.get(i));
assertEquals(3,ai.getAndAdd(i,-4));
assertEquals(-1,ai.get(i));
}
}
/**
* getAndDecrement returns previous value and decrements
*/
public void testGetAndDecrement() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(1,ai.getAndDecrement(i));
assertEquals(0,ai.getAndDecrement(i));
assertEquals(-1,ai.getAndDecrement(i));
}
}
/**
* getAndIncrement returns previous value and increments
*/
public void testGetAndIncrement() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(1,ai.getAndIncrement(i));
assertEquals(2,ai.get(i));
ai.set(i,-2);
assertEquals(-2,ai.getAndIncrement(i));
assertEquals(-1,ai.getAndIncrement(i));
assertEquals(0,ai.getAndIncrement(i));
assertEquals(1,ai.get(i));
}
}
/**
* addAndGet adds given value to current, and returns current value
*/
public void testAddAndGet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(3,ai.addAndGet(i,2));
assertEquals(3,ai.get(i));
assertEquals(-1,ai.addAndGet(i,-4));
assertEquals(-1,ai.get(i));
}
}
/**
* decrementAndGet decrements and returns current value
*/
public void testDecrementAndGet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(0,ai.decrementAndGet(i));
assertEquals(-1,ai.decrementAndGet(i));
assertEquals(-2,ai.decrementAndGet(i));
assertEquals(-2,ai.get(i));
}
}
/**
* incrementAndGet increments and returns current value
*/
public void testIncrementAndGet() {
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i) {
ai.set(i, 1);
assertEquals(2,ai.incrementAndGet(i));
assertEquals(2,ai.get(i));
ai.set(i, -2);
assertEquals(-1,ai.incrementAndGet(i));
assertEquals(0,ai.incrementAndGet(i));
assertEquals(1,ai.incrementAndGet(i));
assertEquals(1,ai.get(i));
}
}
static final int COUNTDOWN = 100000;
class Counter implements Runnable {
final AtomicIntegerArray ai;
volatile int counts;
Counter(AtomicIntegerArray a) { ai = a; }
public void run() {
for (;;) {
boolean done = true;
for (int i = 0; i < ai.length(); ++i) {
int v = ai.get(i);
threadAssertTrue(v >= 0);
if (v != 0) {
done = false;
if (ai.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() {
try {
final AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i)
ai.set(i, COUNTDOWN);
Counter c1 = new Counter(ai);
Counter c2 = new Counter(ai);
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);
}
catch(InterruptedException ie) {
unexpectedException();
}
}
/**
* a deserialized serialized array holds same values
*/
public void testSerialization() {
AtomicIntegerArray l = new AtomicIntegerArray(SIZE);
for (int i = 0; i < SIZE; ++i)
l.set(i, -i);
try {
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));
AtomicIntegerArray r = (AtomicIntegerArray) in.readObject();
for (int i = 0; i < SIZE; ++i) {
assertEquals(l.get(i), r.get(i));
}
} catch(Exception e){
e.printStackTrace();
unexpectedException();
}
}
/**
* toString returns current value.
*/
public void testToString() {
int[] a = { 17, 3, -42, 99, -7};
AtomicIntegerArray ai = new AtomicIntegerArray(a);
assertEquals(Arrays.toString(a), ai.toString());
}
}