Subj : Re: Semaphores and pthreads
To   : comp.programming.threads
From : Jomu
Date : Sun Jan 09 2005 01:27 pm

As prev poster said - never mix sema with mutexes, unless you must :).
Sema are good for their async safety but this is probably not of
interest if you are threads newbie. Just keep them in mind, everyone
needs them sometimes :). As their man page says: "This is the only
thread synchronization  function  provided  by POSIX threads that is
async-signal safe." (This is from SEMAPHORES(3) manpage on Linux).

Another interesting difference is count - semaphores keep count, as
opposed to cond_ vars - they are signaled or not, nothing else.

dd

.