[m-rev.] for post-commit review: isolate all dependencies on POSIX unnamed semaphores

[Peter Wang]

On Thu, 29 Sep 2016 14:00:02 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> +#if defined(MR_MAC_OSX)
> +    #define MR_SEM_TIMED_WAIT(sem, abstime, from)                       \
> +        ( MR_debug_threads ?                                            \
> +            MR_sem_timed_wait((sem), (abstime), (from))                 \
> +        :                                                               \
> +            MR_fatal_error("sem_timedwait not supported on Mac OS X")   \
> +        )
> +#else
> +    #define MR_SEM_TIMED_WAIT(sem, abstime, from)                       \
> +        ( MR_debug_threads ?                                            \
> +            MR_sem_timed_wait((sem), (abstime), (from))                 \
> +        :                                                               \
> +            sem_timedwait((sem))                                        \
> +        )
> +#endif

Looks fine.  It's no big deal but IMHO we should have stuck to the
pthreads naming.

I see that we already have MR_WAIT, MR_TIMED_WAIT (with the underscore).
It might be worth renaming them to MR_COND_WAIT, MR_COND_TIMEDWAIT to
disambiguate them from the semaphore operations, and then do
MR_COND_SIGNAL and MR_COND_BROADCAST as well.

Peter