Wakes up all the threads blocked on the condition variable.
#include <synch.h>
int cond_broadcast (
cond_t *cvp );
(IN) Points to the condition variable to signal.
Returns 0. No error conditions have been defined.
Condition variables are stateless. Calling cond_broadcast on a condition variable that does not have any waiting threads has no effect and is not remembered; a subsequent call to cond_wait or cond_timedwait blocks the calling thread.