Returns an estimate of the total number of tasks currently held
in queues by worker threads (but not including tasks submitted
to the pool that have not begun executing). This value is only
an approximation, obtained by iterating across all threads in
the pool. This method may be useful for tuning task
granularities.
Returns an estimate of the total number of tasks currently held in queues by worker threads (but not including tasks submitted to the pool that have not begun executing). This value is only an approximation, obtained by iterating across all threads in the pool. This method may be useful for tuning task granularities.
@return the number of queued tasks