Returns the length of the queue of threads waiting to take instances from this deque. See disclaimer on accuracy
in {@link java.util.concurrent.locks.ReentrantLock#getWaitQueueLength(Condition)}.
@return number of threads waiting on this deque's notEmpty condition.
Returns the length of the queue of threads waiting to take instances from this deque. See disclaimer on accuracy in {@link java.util.concurrent.locks.ReentrantLock#getWaitQueueLength(Condition)}.
@return number of threads waiting on this deque's notEmpty condition.