Use cond_broadcast(3C) to unblock all threads that are blocked on the condition variable pointed to by cv. When no threads are blocked on the condition variable, then cond_broadcast() has no effect.
#include <thread.h> int cond_broadcast(cond_t *cv);
cond_broadcast() returns 0 if successful. When the following condition is detected, cond_broadcast() fails and returns the corresponding value.
EFAULT
Description:cv points to an illegal address.