Finally, signaling functionality completes pthread_cond_wait functionality.
The first option there is to signal to one individual threads blocked on a pthread_cond_wait.
A peculiarity of this operation is that if there is not any threads blocked on the condition variable,
then the signal is lost.
int pthread_cond_signal(pthread_cond_t *cond);
Another useful feature allows you to wake up all threads that are blocked
on a condition variable, signaling an operation by flooding (i.e. broadcasting):
int pthread_cond_broadcast(pthread_cond_t *cond);
