getWaitQueueLength
Returns an estimate of the number of threads waiting on the given condition associated with this synchronizer. Note that because timeouts and interrupts may occur at any time, the estimate serves only as an upper bound on the actual number of waiters. This method is designed for use in monitoring system state, not for synchronization control.
Return
the estimated number of waiting threads
Parameters
condition
the condition
Throws
if exclusive synchronization is not held
if the given condition is not associated with this synchronizer
if the condition is null