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ConcurrentLinkedQueueTest.javaAPI DocAndroid 1.5 API15260Wed May 06 22:41:02 BST 2009tests.api.java.util.concurrent

ConcurrentLinkedQueueTest

public class ConcurrentLinkedQueueTest extends JSR166TestCase

Fields Summary
Constructors Summary
Methods Summary
public static voidmain(java.lang.String[] args)

        junit.textui.TestRunner.run (suite());        
    
private java.util.concurrent.ConcurrentLinkedQueuepopulatedQueue(int n)
Create a queue of given size containing consecutive Integers 0 ... n.

        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        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;
    
public static junit.framework.Testsuite()

        return new TestSuite(ConcurrentLinkedQueueTest.class);
    
public voidtestAdd()
add returns true

        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            assertTrue(q.add(new Integer(i)));
        }
    
public voidtestAddAll1()
addAll(null) throws NPE

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            q.addAll(null);
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestAddAll2()
addAll of a collection with null elements throws NPE

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            Integer[] ints = new Integer[SIZE];
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestAddAll3()
addAll of a collection with any null elements throws NPE after possibly adding some elements

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new Integer(i);
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestAddAll5()
Queue contains all elements, in traversal order, of successful addAll

        try {
            Integer[] empty = new Integer[0];
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE; ++i)
                ints[i] = new Integer(i);
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            assertFalse(q.addAll(Arrays.asList(empty)));
            assertTrue(q.addAll(Arrays.asList(ints)));
            for (int i = 0; i < SIZE; ++i)
                assertEquals(ints[i], q.poll());
        }
        finally {}
    
public voidtestAddAllSelf()
addAll(this) throws IAE

        try {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            q.addAll(q);
            shouldThrow();
        }
        catch (IllegalArgumentException success) {}
    
public voidtestAddNull()
add(null) throws NPE

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            q.add(null);
            shouldThrow();
        } catch (NullPointerException success) { }   
    
public voidtestClear()
clear removes all elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        q.add(one);
        assertFalse(q.isEmpty());
        q.clear();
        assertTrue(q.isEmpty());
    
public voidtestConstructor1()
new queue is empty

        assertEquals(0, new ConcurrentLinkedQueue().size());
    
public voidtestConstructor3()
Initializing from null Collection throws NPE

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue((Collection)null);
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestConstructor4()
Initializing from Collection of null elements throws NPE

        try {
            Integer[] ints = new Integer[SIZE];
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestConstructor5()
Initializing from Collection with some null elements throws NPE

        try {
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new Integer(i);
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    
public voidtestConstructor6()
Queue contains all elements of collection used to initialize

        try {
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE; ++i)
                ints[i] = new Integer(i);
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            for (int i = 0; i < SIZE; ++i)
                assertEquals(ints[i], q.poll());
        }
        finally {}
    
public voidtestContains()
contains(x) reports true when elements added but not yet removed

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.contains(new Integer(i)));
            q.poll();
            assertFalse(q.contains(new Integer(i)));
        }
    
public voidtestContainsAll()
containsAll(c) is true when c contains a subset of elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            p.add(new Integer(i));
        }
        assertTrue(p.containsAll(q));
    
public voidtestElement()
element returns next element, or throws NSEE if empty

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, ((Integer)q.element()).intValue());
            q.poll();
        }
        try {
            q.element();
            shouldThrow();
        }
        catch (NoSuchElementException success) {}
    
public voidtestEmpty()
isEmpty is true before add, false after

        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertTrue(q.isEmpty());
        q.add(one);
        assertFalse(q.isEmpty());
        q.add(two);
        q.remove();
        q.remove();
        assertTrue(q.isEmpty());
    
public voidtestIterator()
iterator iterates through all elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.iterator();
        while(it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
    
public voidtestIteratorOrdering()
iterator ordering is FIFO

        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);

        int k = 0;
        for (Iterator it = q.iterator(); it.hasNext();) {
            int i = ((Integer)(it.next())).intValue();
            assertEquals(++k, i);
        }

        assertEquals(3, k);
    
public voidtestIteratorRemove()
iterator.remove removes current element

        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);
        Iterator it = q.iterator();
        it.next();
        it.remove();
        it = q.iterator();
        assertEquals(it.next(), two);
        assertEquals(it.next(), three);
        assertFalse(it.hasNext());
    
public voidtestOffer()
Offer returns true

        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertTrue(q.offer(zero));
        assertTrue(q.offer(one));
    
public voidtestOfferNull()
offer(null) throws NPE

        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            q.offer(null);
            shouldThrow();
        } catch (NullPointerException success) { }   
    
public voidtestPeek()
peek returns next element, or null if empty

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, ((Integer)q.peek()).intValue());
            q.poll();
            assertTrue(q.peek() == null ||
                       i != ((Integer)q.peek()).intValue());
        }
        assertNull(q.peek());
    
public voidtestPoll()
poll succeeds unless empty

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, ((Integer)q.poll()).intValue());
        }
        assertNull(q.poll());
    
public voidtestRemove()
remove removes next element, or throws NSEE if empty

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, ((Integer)q.remove()).intValue());
        }
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success){
        }   
    
public voidtestRemoveAll()
removeAll(c) removes only those elements of c and reports true if changed

        for (int i = 1; i < SIZE; ++i) {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            ConcurrentLinkedQueue p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE-i, q.size());
            for (int j = 0; j < i; ++j) {
                Integer I = (Integer)(p.remove());
                assertFalse(q.contains(I));
            }
        }
    
public voidtestRemoveElement()
remove(x) removes x and returns true if present

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.remove(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.remove(new Integer(i)));
            assertFalse(q.remove(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    
public voidtestRetainAll()
retainAll(c) retains only those elements of c and reports true if change

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        ConcurrentLinkedQueue p = populatedQueue(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();
        }
    
public voidtestSerialization()
A deserialized serialized queue has same elements in same order

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        try {
            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
            out.writeObject(q);
            out.close();

            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
            ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
            assertEquals(q.size(), r.size());
            while (!q.isEmpty()) 
                assertEquals(q.remove(), r.remove());
        } catch(Exception e){
            unexpectedException();
        }
    
public voidtestSize()
size changes when elements added and removed

        ConcurrentLinkedQueue q = populatedQueue(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));
        }
    
public voidtestToArray()
toArray contains all elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        Arrays.sort(o);
        for(int i = 0; i < o.length; i++)
            assertEquals(o[i], q.poll());
    
public voidtestToArray1_BadArg()
toArray with incompatible array type throws CCE

        try {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            Object o[] = q.toArray(new String[10] );
            shouldThrow();
        } catch(ArrayStoreException  success){}
    
public voidtestToArray2()
toArray(a) contains all elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        ints = (Integer[])q.toArray(ints);
        Arrays.sort(ints);
        for(int i = 0; i < ints.length; i++)
            assertEquals(ints[i], q.poll());
    
public voidtestToArray_BadArg()
toArray(null) throws NPE

        try {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            Object o[] = q.toArray(null);
            shouldThrow();
        } catch(NullPointerException success){}
    
public voidtestToString()
toString contains toStrings of elements

        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        String s = q.toString();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
        }
    
public voidtestWeaklyConsistentIteration()
Modifications do not cause iterators to fail

        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);

        try {
            for (Iterator it = q.iterator(); it.hasNext();) {
                q.remove();
                it.next();
            }
        }
        catch (ConcurrentModificationException e) {
            shouldThrow();
        }

        assertEquals("queue should be empty again", 0, q.size());