java.util.concurrent.ConcurrentLinkedDeque#remove ( )源码实例Demo

/**
 * 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();
    }
}
 

/**
 * 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 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());
    }
}
 

/**
 * 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();
    }
}
 

/**
 * 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 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());
    }
}
 

@Override
void cancelAcquire(Borrower<POOLABLE> borrower) {
    if (!isDisposed()) { //ignore pool disposed
        ConcurrentLinkedDeque<Borrower<POOLABLE>> q = this.pending;
        if (q.remove(borrower)) {
            PENDING_COUNT.decrementAndGet(this);
        }
    }
}
 

/**
 * 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));
    }
}
 

/**
 * 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) {}
}
 

/**
 * 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));
        }
    }
}
 

/**
 * 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());
}
 

/**
 * 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));
    }
}
 

/**
 * 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) {}
}
 

/**
 * 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));
        }
    }
}
 

/**
 * 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());
}