/*
* 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.Collection;
import java.util.Deque;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.Random;
import java.util.concurrent.ConcurrentLinkedDeque;
import junit.framework.Test;
import junit.framework.TestSuite;
public class ConcurrentLinkedDequeTest 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(ConcurrentLinkedDequeTest.class);
// }
/**
* Returns a new deque of given size containing consecutive
* Integers 0 ... n.
*/
private ConcurrentLinkedDeque<Integer> populatedDeque(int n) {
ConcurrentLinkedDeque<Integer> q = new ConcurrentLinkedDeque<Integer>();
assertTrue(q.isEmpty());
for (int i = 0; i < n; ++i)
assertTrue(q.offer(new Integer(i)));
assertFalse(q.isEmpty());
assertEquals(n, q.size());
return q;
}
/**
* new deque is empty
*/
public void testConstructor1() {
assertTrue(new ConcurrentLinkedDeque().isEmpty());
assertEquals(0, new ConcurrentLinkedDeque().size());
}
/**
* Initializing from null Collection throws NPE
*/
public void testConstructor3() {
try {
new ConcurrentLinkedDeque((Collection)null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Initializing from Collection of null elements throws NPE
*/
public void testConstructor4() {
try {
new ConcurrentLinkedDeque(Arrays.asList(new Integer[SIZE]));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Initializing from Collection with some null elements throws NPE
*/
public void testConstructor5() {
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE - 1; ++i)
ints[i] = new Integer(i);
try {
new ConcurrentLinkedDeque(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Deque contains all elements of collection used to initialize
*/
public void testConstructor6() {
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE; ++i)
ints[i] = new Integer(i);
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque(Arrays.asList(ints));
for (int i = 0; i < SIZE; ++i)
assertEquals(ints[i], q.poll());
}
/**
* isEmpty is true before add, false after
*/
public void testEmpty() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertTrue(q.isEmpty());
q.add(one);
assertFalse(q.isEmpty());
q.add(two);
q.remove();
q.remove();
assertTrue(q.isEmpty());
}
/**
* size() changes when elements added and removed
*/
public void testSize() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(SIZE - i, q.size());
q.remove();
}
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.size());
q.add(new Integer(i));
}
}
/**
* push(null) throws NPE
*/
public void testPushNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.push(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* peekFirst() returns element inserted with push
*/
public void testPush() {
ConcurrentLinkedDeque q = populatedDeque(3);
q.pollLast();
q.push(four);
assertSame(four, q.peekFirst());
}
/**
* pop() removes first element, or throws NSEE if empty
*/
public void testPop() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.pop());
}
try {
q.pop();
shouldThrow();
} catch (NoSuchElementException success) {}
}
/**
* offer(null) throws NPE
*/
public void testOfferNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.offer(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* offerFirst(null) throws NPE
*/
public void testOfferFirstNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.offerFirst(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* offerLast(null) throws NPE
*/
public void testOfferLastNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.offerLast(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* offer(x) succeeds
*/
public void testOffer() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertTrue(q.offer(zero));
assertTrue(q.offer(one));
assertSame(zero, q.peekFirst());
assertSame(one, q.peekLast());
}
/**
* offerFirst(x) succeeds
*/
public void testOfferFirst() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertTrue(q.offerFirst(zero));
assertTrue(q.offerFirst(one));
assertSame(one, q.peekFirst());
assertSame(zero, q.peekLast());
}
/**
* offerLast(x) succeeds
*/
public void testOfferLast() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertTrue(q.offerLast(zero));
assertTrue(q.offerLast(one));
assertSame(zero, q.peekFirst());
assertSame(one, q.peekLast());
}
/**
* add(null) throws NPE
*/
public void testAddNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.add(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addFirst(null) throws NPE
*/
public void testAddFirstNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.addFirst(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addLast(null) throws NPE
*/
public void testAddLastNull() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.addLast(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* add(x) succeeds
*/
public void testAdd() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertTrue(q.add(zero));
assertTrue(q.add(one));
assertSame(zero, q.peekFirst());
assertSame(one, q.peekLast());
}
/**
* addFirst(x) succeeds
*/
public void testAddFirst() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
q.addFirst(zero);
q.addFirst(one);
assertSame(one, q.peekFirst());
assertSame(zero, q.peekLast());
}
/**
* addLast(x) succeeds
*/
public void testAddLast() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
q.addLast(zero);
q.addLast(one);
assertSame(zero, q.peekFirst());
assertSame(one, q.peekLast());
}
/**
* addAll(null) throws NPE
*/
public void testAddAll1() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.addAll(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addAll(this) throws IAE
*/
public void testAddAllSelf() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
try {
q.addAll(q);
shouldThrow();
} catch (IllegalArgumentException success) {}
}
/**
* addAll of a collection with null elements throws NPE
*/
public void testAddAll2() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
try {
q.addAll(Arrays.asList(new Integer[SIZE]));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addAll of a collection with any null elements throws NPE after
* possibly adding some elements
*/
public void testAddAll3() {
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE - 1; ++i)
ints[i] = new Integer(i);
try {
q.addAll(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Deque contains all elements, in traversal order, of successful addAll
*/
public void testAddAll5() {
Integer[] empty = new Integer[0];
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE; ++i)
ints[i] = new Integer(i);
ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
assertFalse(q.addAll(Arrays.asList(empty)));
assertTrue(q.addAll(Arrays.asList(ints)));
for (int i = 0; i < SIZE; ++i)
assertEquals(ints[i], q.poll());
}
/**
* pollFirst() succeeds unless empty
*/
public void testPollFirst() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.pollFirst());
}
assertNull(q.pollFirst());
}
/**
* pollLast() succeeds unless empty
*/
public void testPollLast() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = SIZE - 1; i >= 0; --i) {
assertEquals(i, q.pollLast());
}
assertNull(q.pollLast());
}
/**
* poll() succeeds unless empty
*/
public void testPoll() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.poll());
}
assertNull(q.poll());
}
/**
* peek() returns next element, or null if empty
*/
public void testPeek() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.peek());
assertEquals(i, q.poll());
assertTrue(q.peek() == null ||
!q.peek().equals(i));
}
assertNull(q.peek());
}
/**
* element() returns first element, or throws NSEE if empty
*/
public void testElement() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.element());
assertEquals(i, q.poll());
}
try {
q.element();
shouldThrow();
} catch (NoSuchElementException success) {}
}
/**
* remove() removes next element, or throws NSEE if empty
*/
public void testRemove() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.remove());
}
try {
q.remove();
shouldThrow();
} catch (NoSuchElementException success) {}
}
/**
* remove(x) removes x and returns true if present
*/
public void testRemoveElement() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 1; i < SIZE; i += 2) {
assertTrue(q.contains(i));
assertTrue(q.remove(i));
assertFalse(q.contains(i));
assertTrue(q.contains(i - 1));
}
for (int i = 0; i < SIZE; i += 2) {
assertTrue(q.contains(i));
assertTrue(q.remove(i));
assertFalse(q.contains(i));
assertFalse(q.remove(i + 1));
assertFalse(q.contains(i + 1));
}
assertTrue(q.isEmpty());
}
/**
* peekFirst() returns next element, or null if empty
*/
public void testPeekFirst() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.peekFirst());
assertEquals(i, q.pollFirst());
assertTrue(q.peekFirst() == null ||
!q.peekFirst().equals(i));
}
assertNull(q.peekFirst());
}
/**
* peekLast() returns next element, or null if empty
*/
public void testPeekLast() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = SIZE - 1; i >= 0; --i) {
assertEquals(i, q.peekLast());
assertEquals(i, q.pollLast());
assertTrue(q.peekLast() == null ||
!q.peekLast().equals(i));
}
assertNull(q.peekLast());
}
/**
* getFirst() returns first element, or throws NSEE if empty
*/
public void testFirstElement() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.getFirst());
assertEquals(i, q.pollFirst());
}
try {
q.getFirst();
shouldThrow();
} catch (NoSuchElementException success) {}
}
/**
* getLast() returns last element, or throws NSEE if empty
*/
public void testLastElement() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = SIZE - 1; i >= 0; --i) {
assertEquals(i, q.getLast());
assertEquals(i, q.pollLast());
}
try {
q.getLast();
shouldThrow();
} catch (NoSuchElementException success) {}
assertNull(q.peekLast());
}
/**
* removeFirst() removes first element, or throws NSEE if empty
*/
public void testRemoveFirst() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.removeFirst());
}
try {
q.removeFirst();
shouldThrow();
} catch (NoSuchElementException success) {}
assertNull(q.peekFirst());
}
/**
* removeLast() removes last element, or throws NSEE if empty
*/
public void testRemoveLast() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = SIZE - 1; i >= 0; --i) {
assertEquals(i, q.removeLast());
}
try {
q.removeLast();
shouldThrow();
} catch (NoSuchElementException success) {}
assertNull(q.peekLast());
}
/**
* removeFirstOccurrence(x) removes x and returns true if present
*/
public void testRemoveFirstOccurrence() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 1; i < SIZE; i += 2) {
assertTrue(q.removeFirstOccurrence(new Integer(i)));
}
for (int i = 0; i < SIZE; i += 2) {
assertTrue(q.removeFirstOccurrence(new Integer(i)));
assertFalse(q.removeFirstOccurrence(new Integer(i + 1)));
}
assertTrue(q.isEmpty());
}
/**
* removeLastOccurrence(x) removes x and returns true if present
*/
public void testRemoveLastOccurrence() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 1; i < SIZE; i += 2) {
assertTrue(q.removeLastOccurrence(new Integer(i)));
}
for (int i = 0; i < SIZE; i += 2) {
assertTrue(q.removeLastOccurrence(new Integer(i)));
assertFalse(q.removeLastOccurrence(new Integer(i + 1)));
}
assertTrue(q.isEmpty());
}
/**
* contains(x) reports true when elements added but not yet removed
*/
public void testContains() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertTrue(q.contains(new Integer(i)));
q.poll();
assertFalse(q.contains(new Integer(i)));
}
}
/**
* clear() removes all elements
*/
public void testClear() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
q.clear();
assertTrue(q.isEmpty());
assertEquals(0, q.size());
q.add(one);
assertFalse(q.isEmpty());
q.clear();
assertTrue(q.isEmpty());
}
/**
* containsAll(c) is true when c contains a subset of elements
*/
public void testContainsAll() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
ConcurrentLinkedDeque p = new ConcurrentLinkedDeque();
for (int i = 0; i < SIZE; ++i) {
assertTrue(q.containsAll(p));
assertFalse(p.containsAll(q));
p.add(new Integer(i));
}
assertTrue(p.containsAll(q));
}
/**
* retainAll(c) retains only those elements of c and reports true if change
*/
public void testRetainAll() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
ConcurrentLinkedDeque p = populatedDeque(SIZE);
for (int i = 0; i < SIZE; ++i) {
boolean changed = q.retainAll(p);
if (i == 0)
assertFalse(changed);
else
assertTrue(changed);
assertTrue(q.containsAll(p));
assertEquals(SIZE - i, q.size());
p.remove();
}
}
/**
* removeAll(c) removes only those elements of c and reports true if changed
*/
public void testRemoveAll() {
for (int i = 1; i < SIZE; ++i) {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
ConcurrentLinkedDeque p = populatedDeque(i);
assertTrue(q.removeAll(p));
assertEquals(SIZE - i, q.size());
for (int j = 0; j < i; ++j) {
Integer x = (Integer)(p.remove());
assertFalse(q.contains(x));
}
}
}
/**
* toArray() contains all elements in FIFO order
*/
public void testToArray() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
Object[] o = q.toArray();
for (int i = 0; i < o.length; i++)
assertSame(o[i], q.poll());
}
/**
* toArray(a) contains all elements in FIFO order
*/
public void testToArray2() {
ConcurrentLinkedDeque<Integer> q = populatedDeque(SIZE);
Integer[] ints = new Integer[SIZE];
Integer[] array = q.toArray(ints);
assertSame(ints, array);
for (int i = 0; i < ints.length; i++)
assertSame(ints[i], q.poll());
}
/**
* toArray(null) throws NullPointerException
*/
public void testToArray_NullArg() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
try {
q.toArray(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* toArray(incompatible array type) throws ArrayStoreException
*/
public void testToArray1_BadArg() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
try {
q.toArray(new String[10]);
shouldThrow();
} catch (ArrayStoreException success) {}
}
/**
* Iterator iterates through all elements
*/
public void testIterator() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
Iterator it = q.iterator();
int i;
for (i = 0; it.hasNext(); i++)
assertTrue(q.contains(it.next()));
assertEquals(i, SIZE);
assertIteratorExhausted(it);
}
/**
* iterator of empty collection has no elements
*/
public void testEmptyIterator() {
Deque c = new ConcurrentLinkedDeque();
assertIteratorExhausted(c.iterator());
assertIteratorExhausted(c.descendingIterator());
}
/**
* Iterator ordering is FIFO
*/
public void testIteratorOrdering() {
final ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
q.add(one);
q.add(two);
q.add(three);
int k = 0;
for (Iterator it = q.iterator(); it.hasNext();) {
assertEquals(++k, it.next());
}
assertEquals(3, k);
}
/**
* Modifications do not cause iterators to fail
*/
public void testWeaklyConsistentIteration() {
final ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
q.add(one);
q.add(two);
q.add(three);
for (Iterator it = q.iterator(); it.hasNext();) {
q.remove();
it.next();
}
assertEquals("deque should be empty again", 0, q.size());
}
/**
* iterator.remove() removes current element
*/
public void testIteratorRemove() {
final ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
final Random rng = new Random();
for (int iters = 0; iters < 100; ++iters) {
int max = rng.nextInt(5) + 2;
int split = rng.nextInt(max - 1) + 1;
for (int j = 1; j <= max; ++j)
q.add(new Integer(j));
Iterator it = q.iterator();
for (int j = 1; j <= split; ++j)
assertEquals(it.next(), new Integer(j));
it.remove();
assertEquals(it.next(), new Integer(split + 1));
for (int j = 1; j <= split; ++j)
q.remove(new Integer(j));
it = q.iterator();
for (int j = split + 1; j <= max; ++j) {
assertEquals(it.next(), new Integer(j));
it.remove();
}
assertFalse(it.hasNext());
assertTrue(q.isEmpty());
}
}
/**
* Descending iterator iterates through all elements
*/
public void testDescendingIterator() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
int i = 0;
Iterator it = q.descendingIterator();
while (it.hasNext()) {
assertTrue(q.contains(it.next()));
++i;
}
assertEquals(i, SIZE);
assertFalse(it.hasNext());
try {
it.next();
shouldThrow();
} catch (NoSuchElementException success) {}
}
/**
* Descending iterator ordering is reverse FIFO
*/
public void testDescendingIteratorOrdering() {
final ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
for (int iters = 0; iters < 100; ++iters) {
q.add(new Integer(3));
q.add(new Integer(2));
q.add(new Integer(1));
int k = 0;
for (Iterator it = q.descendingIterator(); it.hasNext();) {
assertEquals(++k, it.next());
}
assertEquals(3, k);
q.remove();
q.remove();
q.remove();
}
}
/**
* descendingIterator.remove() removes current element
*/
public void testDescendingIteratorRemove() {
final ConcurrentLinkedDeque q = new ConcurrentLinkedDeque();
final Random rng = new Random();
for (int iters = 0; iters < 100; ++iters) {
int max = rng.nextInt(5) + 2;
int split = rng.nextInt(max - 1) + 1;
for (int j = max; j >= 1; --j)
q.add(new Integer(j));
Iterator it = q.descendingIterator();
for (int j = 1; j <= split; ++j)
assertEquals(it.next(), new Integer(j));
it.remove();
assertEquals(it.next(), new Integer(split + 1));
for (int j = 1; j <= split; ++j)
q.remove(new Integer(j));
it = q.descendingIterator();
for (int j = split + 1; j <= max; ++j) {
assertEquals(it.next(), new Integer(j));
it.remove();
}
assertFalse(it.hasNext());
assertTrue(q.isEmpty());
}
}
/**
* toString() contains toStrings of elements
*/
public void testToString() {
ConcurrentLinkedDeque q = populatedDeque(SIZE);
String s = q.toString();
for (int i = 0; i < SIZE; ++i) {
assertTrue(s.contains(String.valueOf(i)));
}
}
/**
* A deserialized serialized deque has same elements in same order
*/
public void testSerialization() throws Exception {
Queue x = populatedDeque(SIZE);
Queue y = serialClone(x);
assertNotSame(x, y);
assertEquals(x.size(), y.size());
assertEquals(x.toString(), y.toString());
assertTrue(Arrays.equals(x.toArray(), y.toArray()));
while (!x.isEmpty()) {
assertFalse(y.isEmpty());
assertEquals(x.remove(), y.remove());
}
assertTrue(y.isEmpty());
}
/**
* contains(null) always return false.
* remove(null) always throws NullPointerException.
*/
public void testNeverContainsNull() {
Deque<?>[] qs = {
new ConcurrentLinkedDeque<Object>(),
populatedDeque(2),
};
for (Deque<?> q : qs) {
assertFalse(q.contains(null));
try {
assertFalse(q.remove(null));
shouldThrow();
} catch (NullPointerException success) {}
try {
assertFalse(q.removeFirstOccurrence(null));
shouldThrow();
} catch (NullPointerException success) {}
try {
assertFalse(q.removeLastOccurrence(null));
shouldThrow();
} catch (NullPointerException success) {}
}
}
}