Hello, I think I have found a PR relating to my question:
http://gnats.netbsd.org/38554 I am implementing a semaphore system for applications. To wait on a semaphore to become ready, it does basically this: do { khs->khs_waiters++; error = cv_timedwait_sig(&khs->khs_cv, &khs->khs_interlock, mstohz((flags & SEM_RELATIVE_TIMEOUT) ? timeout : 0)); khs->khs_waiters--; [...] } while (khs->khs_count - count < 0); I have seen that cv_signal() on a CV unblocks all threads waiting on it, instead of just one. That this could happen is briefly mentioned in condvar(9). I think the problem is that when cv_timedwait_sig() is called repeatedly, the original timeout is used again and again, adding up to an unpredictable amount of time. If that is the case, how can it be solved best? Is cv_timedwaitbt_sig() suitable? Or should one track sleep and wakeup times and calculate a new timeout each time? Thanks, Stephan
