[Spice-devel] [spice-gtk PATCH v5 4/4] agent: sync guest audio with client values

[Marc-André Lureau]

Hi

----- Original Message -----
> Hi,
> On Fri, Apr 03, 2015 at 04:34:30PM +0200, Marc-André Lureau wrote:
> > Hi
> >
> > On Fri, Apr 3, 2015 at 3:53 PM, Victor Toso <victortoso at redhat.com> wrote:
> >
> > > +    SPICE_AUDIO_GET_CLASS(audio)->get_playback_volume_info_async(audio,
> > > +            audio_playback_volume_info_cb, main_channel);
> > >
> >
> > It would need to keep a reference on main_channel, and an
> > audio_sync_cancellable for the case where the channel is to be
> > disconnected.
> > 
> > Also, a channel may be recycled. The state should be reset in
> > channel_reset() for further usages.
> 
> Sorry, I did not understand why I need to keep a reference to
> main_channel in this case and what should be done when the
> channel-playback or channel-record is reset.
> 
> Could you please clarify?

If the main channel is destroyed before the async callback is called this will run into criticals (in the best case ;)

Using a cancellable and a reference on the channel will ensure that you can cancel the call and run the callback with a valid reference.

Finally, the channel_reset() is there to clean-up the channel state so it can be reused for a new connection (it's not the best design ever, but it avoids breaking API or moving the channel state in another structure). If the channel has been configured by the client, it should keep those values, but any channel state should be cleared (the agent_volume_playback_sync for instance)