Portable Conditional Wait for Inter-Process?

[Pierre-Luc Drouin]

Hi,

I am looking for a portable solution to put a process into a timed wait 
(a la pthread_cond_timedwait) such that it can be waken up by another 
process using something similar to pthread_cond_broadcast (there might 
be many waiters). I guess shared pthread condition variables are not 
supported by FreeBSD, right? Is there a portable way to do this? The 
only solution I can think of right now is to use  alarm and sigwait on 
the waiters side and kill(wpid,SIGCONT) on the other side with a list of 
pids.

Thanks!