1481152 - Restrict number of concurrent uses of an audio input device in a child process

Status: RESOLVED FIXED

(Core :: WebRTC: Audio/Video, enhancement, P2)

Description

[Andreas Pehrson [:pehrsons]]

Bug 1404977 made it possible to access an audio input device more than once per child process.

This has revealed issues (bug 1480348) with pulseaudio or our cubeb backend for pulseaudio or the combination thereof.

Try with [1]. The more open audio streams one has, the longer the next one takes to resolve, eventually busting pulseaudio.

For now we can try to relieve this issue by putting an artificial limit close to the old technical limit of 1 concurrent uses.

Note that it's always been possible to achieve the same symptoms by opening streams in different child processes. However with the possibility for an application to trigger this with windows and/or iframes the trigger surface has greatly increased.


[1] https://codepen.io/SingingTree/pen/BxWePB

Comment 1

[Eric Rescorla (:ekr)]

If you are going to add a restriction here, you should add it just to Linux. This creates an inconsistency in how various versions of Fx behave, but that's less important than having an inconsistency with the spec.

Comment 2

[Paul Adenot (:padenot)]

Attachment: Bug 1481152 - Allow up to one audio input stream per process on Linux, when using PulseAudio. r?pehrsons

Comment 3

[Paul Adenot (:padenot)]

Attachment: Bug 1481152 - Restrict to a single input stream per process on Linux, when using PulseAudio and audio remoting is enabled. r?pehrsons

Comment 4

[Andreas Pehrson [:pehrsons]]

Comment on attachment 9008080 [details]
Bug 1481152 - Restrict to a single input stream per process on Linux, when using PulseAudio and audio remoting is enabled. r?pehrsons

Andreas Pehrson [:pehrsons] has approved the revision.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ae4bb7377de2
Restrict to a single input stream per process on Linux, when using PulseAudio and audio remoting is enabled. r=pehrsons

Comment 6

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/ae4bb7377de2