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

Tanu Kaskinen tanuk at iki.fi
Fri Jul 5 07:41:55 UTC 2019


On Tue, 2019-07-02 at 09:08 +0200, Georg Chini wrote:
> On 02.07.19 08:43, Tanu Kaskinen wrote:
> > On Mon, 2019-07-01 at 08:03 +0200, 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
> > > > > > 
> > > > > > Signed-off-by: Hui Wang <hui.wang at canonical.com>
> > > > > > ---
> > > > > >     src/modules/dbus/iface-core.c               |  2 +-
> > > > > >     src/modules/module-default-device-restore.c |  2 +-
> > > > > >     src/modules/module-switch-on-connect.c      | 27 ++--------------
> > > > > >     src/pulsecore/cli-command.c                 |  2 +-
> > > > > >     src/pulsecore/core.c                        | 10 ++++--
> > > > > >     src/pulsecore/core.h                        |  4 +--
> > > > > >     src/pulsecore/device-port.c                 |  2 +-
> > > > > >     src/pulsecore/protocol-native.c             |  2 +-
> > > > > >     src/pulsecore/sink.c                        | 35 +++++++++++++++++++--
> > > > > >     src/pulsecore/sink.h                        |  6 ++++
> > > > > >     10 files changed, 54 insertions(+), 38 deletions(-)
> > > > > > 
> > > > > > diff --git a/src/modules/dbus/iface-core.c b/src/modules/dbus/iface-core.c
> > > > > > index 5229c0467..9763480d2 100644
> > > > > > --- a/src/modules/dbus/iface-core.c
> > > > > > +++ b/src/modules/dbus/iface-core.c
> > > > > > @@ -721,7 +721,7 @@ static void handle_set_fallback_sink(DBusConnection *conn, DBusMessage *msg, DBu
> > > > > >             return;
> > > > > >         }
> > > > > >     
> > > > > > -    pa_core_set_configured_default_sink(c->core, pa_dbusiface_device_get_sink(fallback_sink)->name);
> > > > > > +    pa_core_set_configured_default_sink(c->core, pa_dbusiface_device_get_sink(fallback_sink)->name, true);
> > > > > >     
> > > > > >         pa_dbus_send_empty_reply(conn, msg);
> > > > > >     }
> > > > > > diff --git a/src/modules/module-default-device-restore.c b/src/modules/module-default-device-restore.c
> > > > > > index c4dbad99f..33e74c071 100644
> > > > > > --- a/src/modules/module-default-device-restore.c
> > > > > > +++ b/src/modules/module-default-device-restore.c
> > > > > > @@ -69,7 +69,7 @@ static void load(struct userdata *u) {
> > > > > >                 pa_log_warn("Invalid sink name: %s", ln);
> > > > > >             else {
> > > > > >                 pa_log_info("Restoring default sink '%s'.", ln);
> > > > > > -            pa_core_set_configured_default_sink(u->core, ln);
> > > > > > +            pa_core_set_configured_default_sink(u->core, ln, false);
> > > > > >             }
> > > > > >     
> > > > > >         } else if (errno != ENOENT)
> > > > > > diff --git a/src/modules/module-switch-on-connect.c b/src/modules/module-switch-on-connect.c
> > > > > > index f0cb29a7c..3ceac8b4f 100644
> > > > > > --- a/src/modules/module-switch-on-connect.c
> > > > > > +++ b/src/modules/module-switch-on-connect.c
> > > > > > @@ -54,9 +54,6 @@ struct userdata {
> > > > > >     };
> > > > > >     
> > > > > >     static pa_hook_result_t sink_put_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
> > > > > > -    pa_sink_input *i;
> > > > > > -    uint32_t idx;
> > > > > > -    pa_sink *old_default_sink;
> > > > > >         const char *s;
> > > > > >         struct userdata *u = userdata;
> > > > > >     
> > > > > > @@ -88,7 +85,7 @@ static pa_hook_result_t sink_put_hook_callback(pa_core *c, pa_sink *sink, void*
> > > > > >     
> > > > > >         /* No default sink, nothing to move away, just set the new default */
> > > > > >         if (!c->default_sink) {
> > > > > > -        pa_core_set_configured_default_sink(c, sink->name);
> > > > > > +        pa_core_set_configured_default_sink(c, sink->name, false);
> > > > > >             return PA_HOOK_OK;
> > > > > >         }
> > > > > >     
> > > > > > @@ -103,28 +100,8 @@ static pa_hook_result_t sink_put_hook_callback(pa_core *c, pa_sink *sink, void*
> > > > > >                 return PA_HOOK_OK;
> > > > > >             }
> > > > > >     
> > > > > > -    old_default_sink = c->default_sink;
> > > > > > -
> > > > > >         /* Actually do the switch to the new sink */
> > > > > > -    pa_core_set_configured_default_sink(c, sink->name);
> > > > > > -
> > > > > > -    /* Now move all old inputs over */
> > > > > > -    if (pa_idxset_size(old_default_sink->inputs) <= 0) {
> > > > > > -        pa_log_debug("No sink inputs to move away.");
> > > > > > -        return PA_HOOK_OK;
> > > > > > -    }
> > > > > > -
> > > > > > -    PA_IDXSET_FOREACH(i, old_default_sink->inputs, idx) {
> > > > > > -        if (pa_safe_streq(i->sink->name, i->preferred_sink) || !PA_SINK_INPUT_IS_LINKED(i->state))
> > > > > > -            continue;
> > > > > > -
> > > > > > -        if (pa_sink_input_move_to(i, sink, false) < 0)
> > > > > > -            pa_log_info("Failed to move sink input %u \"%s\" to %s.", i->index,
> > > > > > -                        pa_strnull(pa_proplist_gets(i->proplist, PA_PROP_APPLICATION_NAME)), sink->name);
> > > > > > -        else
> > > > > > -            pa_log_info("Successfully moved sink input %u \"%s\" to %s.", i->index,
> > > > > > -                        pa_strnull(pa_proplist_gets(i->proplist, PA_PROP_APPLICATION_NAME)), sink->name);
> > > > > > -    }
> > > > > > +    pa_core_set_configured_default_sink(c, sink->name, false);
> > > > > I wonder if we could use something like
> > > > > pa_core_set_temporary_default_sink() here
> > > > > and have a variable core->temporary_default_sink that has even higher
> > > > > priority
> > > > > than core->configured_default_sink in the default sink selection
> > > > > process. The temporary
> > > > > default sink could be reset when the sink vanishes again or replaced
> > > > > when another new
> > > > > sink turns up. What module-switch-on-connect does is to temporarily
> > > > > override the default
> > > > > sink that the user configured. If we save this in another variable we
> > > > > would not overwrite
> > > > > the user configured default sink by a sink that is not expected to be
> > > > > present the next
> > > > > time PA is started. But that would be just nice to have.
> > > > I'm against adding that kind of extra complexity without a very good
> > > > justification. module-switch-on-connect should become nearly obsolete
> > > > anyway after this patch set has been merged.
> > > We already talked about this some time ago and you agreed
> > > that this would be useful. Maybe you remember that discussion.
> > I remember that we discussed my initial attempt at implementing what
> > this patch set does. I probably should go back to that discussion to
> > find out why I agreed that we should add a separate "temporary default
> > sink" variable.
> 
> You did not exactly agree to adding a temporary_default_sink
> variable. You agreed however (after some discussion) that
> what module-switch-on-connect does is a temporary override
> of the configured default sink and that there should be a way
> to restore the original default sink. (The user may have set
> another than the highest priority sink as default, see also
> below).
> 
> It seems quite simple to add such a variable and replace it
> when a new sink turns up or set it to NULL if the current
> temporary default sink is removed. This would then make
> it really easy to implement the module-switch-on-connect
> functionality in the core at some later point.

I'm concerned about the complexity of answering the question "how is
the default sink determined". The fact that "default sink" and
"configured default sink" are different things is already bothersome.
Your point about restoring the old configured default sink is
definitely valid, although that problem seems to be not specific to
module-switch-on-connect: if there are 3 sinks, the user can't specify
which of them is the second most preferred sink in case the configured
default sink goes away. Having a priority list of sinks based on manual
configuration history might be a better way to solve this (although I'm
afraid it's not that simple if there are sink with multiple ports).

> > > Consider you add your BT speakers and module-switch-on-connect
> > > makes them the default sink. When you remove them, there is
> > > no guarantee that the default sink will revert to what the user
> > > configured before. Instead PA will choose the sink which it thinks
> > > is best. Also, if you remove the device after a shutdown, PA will
> > > still keep it as the configured default sink and the user will loose
> > > what was configured.
> > > 
> > > So in my opinion we should distinguish if the server changed the
> > > default sink or the user did, though as already said above, it is
> > > not mandatory but only nice to have.
> > > 
> > > I do not see why module-switch-on-connect would become obsolete
> > > - it switches the default sink to a newly appeared sink and there is
> > > nothing in these patches which does that (unless the newly appeared
> > > sink is the configured default sink).
> > When a new sink appears, pa_core_update_default_sink() is called. Since
> > PulseAudio 11.1, bluetooth and USB sinks have higher priority than the
> > internal sound card, so pa_core_update_default_sink() will switch to
> > the BT speakers in your example. The main benefit of module-switch-on-
> > connect was that it moved existing streams to the new sink, but after
> > this patch set that's handled by the core. Therefore there's much less
> > need for module-switch-on-connect.
> > 
> This is true, but only relevant if there is no configured default
> sink. If the configured default sink is set, there will be no switch
> to a newly appearing sink because the configured default sink
> is prioritized over all other sinks. In this case you still need
> module-switch-on-connect.

My estimation is that this is very rarely a problem.

If you have manually selected an external sound card as the default
sink and you then plug in another external sound card, then you may or
may not want to automatically switch to the new sound card. If you
fiddle a lot with two external sound cards and you always want to use
the last one plugged in, then module-switch-on-connect is still useful,
but in this case it doesn't really matter that your old default device
choice is forgotten, because PulseAudio will anyway prefer the
remaining external sound card.

If you have an external sound card and you have manually selected the
internal sound card as the default sink, then module-switch-on-connect
seems like a bad idea, because you probably want to keep the internal
sound card as the default even after plugging out the external sound
card and plugging it back in. If your preference has changed, then it's
expected that you have to restate your preference by manually selecting
the external sound card.

-- 
Tanu

https://www.patreon.com/tanuk
https://liberapay.com/tanuk



More information about the pulseaudio-discuss mailing list