/**
* Adds the specified element to this queue, waiting if necessary for another thread to receive
* it.
*
* @throws InterruptedException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
*/
public void put(E o) throws InterruptedException {
if (o == null) throw new NullPointerException();
if (transferer.transfer(o, false, 0) == null) {
Thread.interrupted();
throw new InterruptedException();
}
}
/**
* Retrieves and removes the head of this queue, if another thread is currently making an element
* available.
*
* @return the head of this queue, or <tt>null</tt> if no element is available.
*/
public E poll() {
return (E) transferer.transfer(null, true, 0);
}
/**
* Retrieves and removes the head of this queue, waiting if necessary up to the specified wait
* time, for another thread to insert it.
*
* @return the head of this queue, or <tt>null</tt> if the specified waiting time elapses before
* an element is present.
* @throws InterruptedException {@inheritDoc}
*/
public E poll(long timeout, TimeUnit unit) throws InterruptedException {
Object e = transferer.transfer(null, true, unit.toNanos(timeout));
if (e != null || !Thread.interrupted()) return (E) e;
throw new InterruptedException();
}
/**
* Retrieves and removes the head of this queue, waiting if necessary for another thread to insert
* it.
*
* @return the head of this queue
* @throws InterruptedException {@inheritDoc}
*/
public E take() throws InterruptedException {
Object e = transferer.transfer(null, false, 0);
if (e != null) return (E) e;
Thread.interrupted();
throw new InterruptedException();
}
/**
* Inserts the specified element into this queue, if another thread is waiting to receive it.
*
* @param e the element to add
* @return <tt>true</tt> if the element was added to this queue, else <tt>false</tt>
* @throws NullPointerException if the specified element is null
*/
public boolean offer(E e) {
if (e == null) throw new NullPointerException();
return transferer.transfer(e, true, 0) != null;
}
/**
* Inserts the specified element into this queue, waiting if necessary up to the specified wait
* time for another thread to receive it.
*
* @return <tt>true</tt> if successful, or <tt>false</tt> if the specified waiting time elapses
* before a consumer appears.
* @throws InterruptedException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
*/
public boolean offer(E o, long timeout, TimeUnit unit) throws InterruptedException {
if (o == null) throw new NullPointerException();
if (transferer.transfer(o, true, unit.toNanos(timeout)) != null) return true;
if (!Thread.interrupted()) return false;
throw new InterruptedException();
}
