[pulseaudio-discuss] Releasing stream resources when the client receives SIGSTOP

[Ricardo Salveti]

Hey,

When investigating the issue we had on Ubuntu Touch, described by bug
https://bugs.launchpad.net/ubuntu-rtm/+source/pulseaudio/+bug/1391230,
I noticed that PulseAudio never releases the resources used by an
active stream if the app gets a SIGSTOP, keeping pulse busy and
consuming cpu until the app resumes or is closed by the user.

On Ubuntu Touch that happens when the application is active playing
audio/video, and the user moves back to the home scopes (Ubuntu Touch
lifecycle will automatically send a SIGSTOP after 5 seconds). When
checking that on my desktop, I also noticed that the same happens (by
forcing a SIGSTOP against mplayer, for example). Pulse only releases
the stream when the app pauses the stream, not necessarily when the
app stops after receiving the signal.

I raised this first with David to understand if it was indeed a valid
use case, and he said that it was indeed something that it was
probably never really considered
(https://bugs.launchpad.net/ubuntu-rtm/+source/pulseaudio/+bug/1391230/comments/8).

So before going and trying to deep dive and find a fix for the issue,
I first wanted to understand from you guys if this is indeed a valid
issue and what would be the best way to get this fixed. I know we're
still using Pulse 4.0 on Ubuntu, but wanted to make sure to get
something that would also be compatible with upstream.

Thanks,
-- 
Ricardo Salveti de Araujo