Mac OS X: add semaphore implementation

Mac OS X: add semaphore implementation

On Wed, Sep 16, 2009 at 11:57:04PM +0200, Lennart Poettering wrote:
> On Wed, 16.09.09 15:15, Daniel Mack (daniel@caiaq.de) wrote:
>
> > +    s = pa_xnew(pa_semaphore, 1);
> > +    MPCreateSemaphore(UINT_MAX, value, &(s->sema));
> > +    pa_assert(s->sema != 0);
>
> Hmm, I'd prefer if the ret val of MPCreateSemaphore() would be checked
> here.
>
> Also I find it a bit weird checking for s->sema, though not
> initializing it to 0 in the beginning. If the call actually failed,
> then the assert will check uninitialized memory. Also, comparing
> pointers with 0 sucks. That should be NULL.
>
> Given that this can not realisitically fail, only in OOM or OOM-like
> situations in which case we abort anyway it mght be enough just writing:
>
> pa_assert_se(MPCreateSemaphore(UINT_MAX, value, &s->sema) == 0);
>
> (Assuming that success is signalled by retval == 0 on MacOSX)
>
> > +void pa_semaphore_free(pa_semaphore *s) {
> > +    pa_assert(s);
> > +    MPDeleteSemaphore(s->sema);
>
> Same here.
>
> > +    pa_xfree(s);
> > +}
> > +
> > +void pa_semaphore_post(pa_semaphore *s) {
> > +    pa_assert(s);
> > +    MPSignalSemaphore(s->sema);
>
> And here.
>
> > +}
> > +
> > +void pa_semaphore_wait(pa_semaphore *s) {
> > +    pa_assert(s);
> > +    /* should probably check return value (-ve is error), noErr is ok. */
> > +    MPWaitOnSemaphore(s->sema, kDurationForever);
>
> And here.

Ok, done. See the patch below.

Daniel

>From 26df2fbae6d9215a3ae084876fb5f79e4d9cf4f0 Mon Sep 17 00:00:00 2001
From: Kim Lester <kim@dfusion.com.au>
Date: Wed, 16 Sep 2009 09:23:39 +0800
Subject: [PATCH] Mac OS X: add semaphore implementation