base/common/src/main/com/thesett/common/util/concurrent/BatchSynchQueueBase.java
public E poll()
    {
        ReentrantLock lock = this.lock;

        lock.lock();

        try
        {
            if (count == 0)
            {
                return null;
            }

            return extract(true, true).getElement();
        }
        finally
        {
            lock.unlock();
        }
    }
public E poll()
    {
        ReentrantLock lock = this.lock;

        lock.lock();

        try
        {
            if (count == 0)
            {
                return null;
            }

            return extract(true, true).getElement();
        }
        finally
        {
            lock.unlock();
        }
    }
Retrieves and removes the head of this queue, or <tt>null</tt> if this queue is empty.

@return The head of this queue, or <tt>null</tt> if this queue is empty.