OK. Lets say you have a pthread_wait(). Or generally a wait() in a program. What exactly happens?
Lets say that a process is waiting a signal to wake up. What does the waiting mean? Meaning what does the system do to determine when the process is going to wake up?
In other words, how is a signal implemented? Does it use at all interrupts (do modern CPU have interrupts used by programs?) or it is all software?