On Tue, 05 Jul 2016 18:30:36 +0200,
Clemens Ladisch wrote:
>
> Takashi Iwai wrote:
> > --- a/src/pcm/pcm.c
> > +++ b/src/pcm/pcm.c
> > @@ -686,6 +686,8 @@ snd_pcm_stream_t snd_pcm_stream(snd_pcm_t *pcm)
> > *
> > * Closes the specified PCM handle and frees all associated
> > * resources.
> > + *
> > + * The function is thread-safe when built with the proper option.
> > */
> > int snd_pcm_close(snd_pcm_t *pcm)
> > {
> > @@ -697,6 +699,7 @@ int snd_pcm_close(snd_pcm_t *pcm)
> > if (err < 0)
> > res = err;
> > }
> > + snd_pcm_lock(pcm);
> > if (pcm->mmap_channels)
> > snd_pcm_munmap(pcm);
> > while (!list_empty(&pcm->async_handlers)) {
> > @@ -704,6 +707,7 @@ int snd_pcm_close(snd_pcm_t *pcm)
> > snd_async_del_handler(h);
> > }
> > err = pcm->ops->close(pcm->op_arg);
> > + snd_pcm_unlock(pcm);
> > if (err < 0)
> > res = err;
> > err = snd_pcm_free(pcm);
>
> Thread safety does not really make sense for a destructor like
> snd_pcm_close(). If any other code is accessing the device at the same
> time, the freeing will make it crash anyway.
That's true. OTOH, snd_pcm_close() does sync before closing, so I
thought it might be not too bad to be prepared for bad programmers.
But I'm fine to get rid of it.
> What would make sense would be to output a debug warning if the device
> is locked, and/or to poison the device (maybe ->ops = NULL).
Yes, more debugging option would be nicer. We can add it later.
thanks,
Takashi
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