[Spice-devel] [spice-server] playback: Don't lose client connection after migration

[Frediano Ziglio]

Merged.

Would be great to have some lower level (lower than having to do a migration) test
(like unit testing) of this stuff.

I was thinking (time ago) of removing the connection field in favour of
also supporting multiple clients too (at least for playback).

Is there a reason to have separate on_new_* functions? They are
called just from constructors.

I noted that these on_new_* functions use client->active however looking
at code it seems that this field is initialized only later basically
having a dead code. Is it really dead code? Were these lines always
dead code?

Frediano

> 
> Acked-by: Jonathon Jongsma <jjongsma at redhat.com>
> 
> 
> On Fri, 2017-04-14 at 09:02 +0200, Christophe Fergeau wrote:
> > Commit 590acf3c556 introduced a regression after migration:
> > PlaybackChannel::connection is never set even if a client is
> > connected,
> > which means the playback channel is non-functional until a client
> > reconnects as all the snd_channel_set_xxx() method checks for a non-
> > NULL
> > PlaybackChannel::connection before sending data to the client.
> > 
> > This commit slightly changes the code flow in
> > on_new_playback_channel_client()/playback_channel_client_constructed(
> > )
> > so that PlaybackChannel::connection is set regardless of what
> > red_client_during_migrate_at_target() returns. This is what was done
> > prior to 590acf3c556.
> > 
> > This resolves https://bugs.freedesktop.org/show_bug.cgi?id=100136
> > 
> > Signed-off-by: Christophe Fergeau <cfergeau at redhat.com>
> > ---
> >  server/sound.c | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > diff --git a/server/sound.c b/server/sound.c
> > index 6a6d965..b50f9fc 100644
> > --- a/server/sound.c
> > +++ b/server/sound.c
> > @@ -991,10 +991,14 @@ static int snd_desired_audio_mode(bool
> > playback_compression, int frequency,
> >  static void on_new_playback_channel_client(SndChannel *channel,
> > SndChannelClient *client)
> >  {
> >      RedsState *reds = red_channel_get_server(RED_CHANNEL(channel));
> > +    RedClient *red_client =
> > red_channel_client_get_client(RED_CHANNEL_CLIENT(client));
> >  
> >      spice_assert(client);
> >  
> >      channel->connection = client;
> > +    if (red_client_during_migrate_at_target(red_client)) {
> > +        return;
> > +    }
> >      snd_set_command(client, SND_PLAYBACK_MODE_MASK);
> >      if (client->active) {
> >          snd_set_command(client, SND_CTRL_MASK);
> > @@ -1036,7 +1040,6 @@ playback_channel_client_constructed(GObject
> > *object)
> >  {
> >      PlaybackChannelClient *playback_client =
> > PLAYBACK_CHANNEL_CLIENT(object);
> >      RedChannel *red_channel =
> > red_channel_client_get_channel(RED_CHANNEL_CLIENT(playback_client));
> > -    RedClient *client =
> > red_channel_client_get_client(RED_CHANNEL_CLIENT(playback_client));
> >      SndChannel *channel = SND_CHANNEL(red_channel);
> >  
> >      G_OBJECT_CLASS(playback_channel_client_parent_class)-
> > >constructed(object);
> > @@ -1061,9 +1064,7 @@ playback_channel_client_constructed(GObject
> > *object)
> >          }
> >      }
> >  
> > -    if (!red_client_during_migrate_at_target(client)) {
> > -        on_new_playback_channel_client(channel,
> > SND_CHANNEL_CLIENT(playback_client));
> > -    }
> > +    on_new_playback_channel_client(channel,
> > SND_CHANNEL_CLIENT(playback_client));
> >  
> >      if (channel->active) {
> >          snd_playback_start(channel);