Signals that the calling thread has arrived at the synchronization point and block until all the participating threads have arrived.
Either the calling thread is one of the first N
threads to arrive at
*this since construction, where
N is the value of the
parameter to the constructor, or the calling thread is already
one of the set of participating threads for
Signal that the calling thread has arrived at the barrier. If this
is the last of the participating threads to arrive then all threads
are unblocked and the barrier is reset, otherwise block until all
the participating threads have arrived.