| Methods Summary |
|---|
| public boolean | add(E e)Inserts the specified element into this delay queue.
return offer(e);
|
| public void | clear()Atomically removes all of the elements from this delay queue.
The queue will be empty after this call returns.
Elements with an unexpired delay are not waited for; they are
simply discarded from the queue.
final ReentrantLock lock = this.lock;
lock.lock();
try {
q.clear();
} finally {
lock.unlock();
}
|
| public int | drainTo(java.util.Collection c)
if (c == null)
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
int n = 0;
for (;;) {
E first = q.peek();
if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
break;
c.add(q.poll());
++n;
}
if (n > 0)
available.signalAll();
return n;
} finally {
lock.unlock();
}
|
| public int | drainTo(java.util.Collection c, int maxElements)
if (c == null)
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
if (maxElements <= 0)
return 0;
final ReentrantLock lock = this.lock;
lock.lock();
try {
int n = 0;
while (n < maxElements) {
E first = q.peek();
if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
break;
c.add(q.poll());
++n;
}
if (n > 0)
available.signalAll();
return n;
} finally {
lock.unlock();
}
|
| public java.util.Iterator | iterator()Returns an iterator over all the elements (both expired and
unexpired) in this queue. The iterator does not return the
elements in any particular order. The returned
Iterator is a "weakly consistent" iterator that will
never throw {@link ConcurrentModificationException}, and
guarantees to traverse elements as they existed upon
construction of the iterator, and may (but is not guaranteed
to) reflect any modifications subsequent to construction.
return new Itr(toArray());
|
| public boolean | offer(E e)Inserts the specified element into this delay queue.
final ReentrantLock lock = this.lock;
lock.lock();
try {
E first = q.peek();
q.offer(e);
if (first == null || e.compareTo(first) < 0)
available.signalAll();
return true;
} finally {
lock.unlock();
}
|
| public boolean | offer(E e, long timeout, java.util.concurrent.TimeUnit unit)Inserts the specified element into this delay queue. As the queue is
unbounded this method will never block.
return offer(e);
|
| public E | peek()Retrieves, but does not remove, the head of this queue, or
returns null if this queue is empty. Unlike
poll, if no expired elements are available in the queue,
this method returns the element that will expire next,
if one exists.
final ReentrantLock lock = this.lock;
lock.lock();
try {
return q.peek();
} finally {
lock.unlock();
}
|
| public E | poll()Retrieves and removes the head of this queue, or returns null
if this queue has no elements with an expired delay.
final ReentrantLock lock = this.lock;
lock.lock();
try {
E first = q.peek();
if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
return null;
else {
E x = q.poll();
assert x != null;
if (q.size() != 0)
available.signalAll();
return x;
}
} finally {
lock.unlock();
}
|
| public E | poll(long timeout, java.util.concurrent.TimeUnit unit)Retrieves and removes the head of this queue, waiting if necessary
until an element with an expired delay is available on this queue,
or the specified wait time expires.
long nanos = unit.toNanos(timeout);
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
E first = q.peek();
if (first == null) {
if (nanos <= 0)
return null;
else
nanos = available.awaitNanos(nanos);
} else {
long delay = first.getDelay(TimeUnit.NANOSECONDS);
if (delay > 0) {
if (nanos <= 0)
return null;
if (delay > nanos)
delay = nanos;
long timeLeft = available.awaitNanos(delay);
nanos -= delay - timeLeft;
} else {
E x = q.poll();
assert x != null;
if (q.size() != 0)
available.signalAll();
return x;
}
}
}
} finally {
lock.unlock();
}
|
| public void | put(E e)Inserts the specified element into this delay queue. As the queue is
unbounded this method will never block.
offer(e);
|
| public int | remainingCapacity()Always returns Integer.MAX_VALUE because
a DelayQueue is not capacity constrained.
return Integer.MAX_VALUE;
|
| public boolean | remove(java.lang.Object o)Removes a single instance of the specified element from this
queue, if it is present, whether or not it has expired.
final ReentrantLock lock = this.lock;
lock.lock();
try {
return q.remove(o);
} finally {
lock.unlock();
}
|
| public int | size()
final ReentrantLock lock = this.lock;
lock.lock();
try {
return q.size();
} finally {
lock.unlock();
}
|
| public E | take()Retrieves and removes the head of this queue, waiting if necessary
until an element with an expired delay is available on this queue.
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
E first = q.peek();
if (first == null) {
available.await();
} else {
long delay = first.getDelay(TimeUnit.NANOSECONDS);
if (delay > 0) {
long tl = available.awaitNanos(delay);
} else {
E x = q.poll();
assert x != null;
if (q.size() != 0)
available.signalAll(); // wake up other takers
return x;
}
}
}
} finally {
lock.unlock();
}
|
| public java.lang.Object[] | toArray()Returns an array containing all of the elements in this queue.
The returned array elements are in no particular order.
The returned array will be "safe" in that no references to it are
maintained by this queue. (In other words, this method must allocate
a new array). The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based
APIs.
final ReentrantLock lock = this.lock;
lock.lock();
try {
return q.toArray();
} finally {
lock.unlock();
}
|
| public T[] | toArray(T[] a)Returns an array containing all of the elements in this queue; the
runtime type of the returned array is that of the specified array.
The returned array elements are in no particular order.
If the queue fits in the specified array, it is returned therein.
Otherwise, a new array is allocated with the runtime type of the
specified array and the size of this queue.
If this queue fits in the specified array with room to spare
(i.e., the array has more elements than this queue), the element in
the array immediately following the end of the queue is set to
null.
Like the {@link #toArray()} method, this method acts as bridge between
array-based and collection-based APIs. Further, this method allows
precise control over the runtime type of the output array, and may,
under certain circumstances, be used to save allocation costs.
The following code can be used to dump a delay queue into a newly
allocated array of Delayed:
Delayed[] a = q.toArray(new Delayed[0]);
Note that toArray(new Object[0]) is identical in function to
toArray().
final ReentrantLock lock = this.lock;
lock.lock();
try {
return q.toArray(a);
} finally {
lock.unlock();
}
|
