[pulseaudio-discuss] [PATCH v2 4/8] core: move sink-inputs conditionally when update default_sink

[Georg Chini]

On 01.07.19 08:03, Georg Chini wrote:
> On 01.07.19 07:08, Tanu Kaskinen wrote:
>> On Sun, 2019-06-30 at 13:52 +0200, Georg Chini wrote:
>>> On 17.01.19 07:53, Hui Wang wrote:
>>>> When the default sink changes, the streams from the old default sink
>>>> should be moved to the new default sink, unless the preferred_sink
>>>> string is set to the old default sink and the active port of the old
>>>> default sink is not unavailable



>>>>    +
>>>> +void pa_sink_move_streams_to_default_sink(pa_core *core, pa_sink 
>>>> *old_sink, bool from_user) {
>>>> +    pa_sink_input *i;
>>>> +    uint32_t idx;
>>>> +    bool old_sink_is_unavailable;
>>> Does this not give a warning about using uninitialized variables?
>>>> +
>>>> +    pa_assert(core);
>>>> +    pa_assert(old_sink);
>>>> +
>>>> +    if (old_sink == core->default_sink)
>>>> +        return;
>>>> +
>>>> +    if (old_sink->active_port && old_sink->active_port->available 
>>>> == PA_AVAILABLE_NO)
>>>> +        old_sink_is_unavailable = true;
>>> This is not sufficient to determine if the old sink is still available.
>>> There are sinks
>>> that do not have ports (null-sink, virtual sinks). I think you will 
>>> need
>>> another boolean
>>> argument to the function which indicates availability of the old sink.
>> The definition of an unavailable sink is that its active port is
>> unavailable. I don't know what kind of sinks you're thinking about
>> here, maybe virtual sinks that are on top of an unavailable hardware
>> sink? There are many places where we check the availability of a sink
>> this way, and I don't think it makes sense to be different here.
>
> I don't understand. Virtual sinks don't have ports. So checking only
> sinks that have an active port excludes all sinks that don't have
> ports like the null-sink and virtual sinks. Following your definition
> above, those sinks are never available.
>
>
Checking the code, only alsa, bluetooth and raop sinks define ports and
the "many places" you are referring to are compare_sinks() and
compare_sources() in core.c and a check in module-switch-on-connect,
which is used to determine the availability of the default sink.