Subj : Re: Predicate for pthread_cond_timedwait() ??
To   : comp.programming.threads
From : David Schwartz
Date : Wed Mar 16 2005 06:02 pm


<recvfrom@gmail.com> wrote in message 
news:1111022385.023902.120750@l41g2000cwc.googlegroups.com...

> Rather than mess with timers and signals in a threaded app,
> I tried using pthread_cond_timedwait() for a condvar that
> will never be signaled.  Is this a good approach?  It seems
> to work fine.

    It's adequate, but usleep/nanosleep would be cleaner.

> Also, I assume this call should be wrapped
> in a loop, since there is no guarantee that the call could
> return for some 'other' reason (whatever that might be, I'm
> not sure).

    Right.

> What should be the predicate for this loop?  A
> zero return value?  E.g.:
>
> r = 0;
> while (r == 0)
>  {
>    r = pthread_cond_timedwait (&x->condvar, &x->mutex, &ts);
>  }

More like:

int ret;
pthread_mutex_lock(&x->mutex);
do
  ret=pthread_cond_timedwait(&x->condvar, &x->mutex, &ts);
   while(ret!=ETIMEDOUT);
pthread_mutex_unlock(&x->mutex);

    DS

.