1237414 - Threadrace when starting/stopping cubeb for AudioCallbackDrivers

Status: RESOLVED FIXED

(Core :: Audio/Video: MediaStreamGraph, defect, P1)

Description

[Randell Jesup [:jesup] (needinfo me)]

AsyncCubebOperation (used for Init and Shutdown of drivers) spawns a new thread at every operation.  This is expensive (on Windows), and more importantly the code relies on Shutdown of a previous driver before another driver starts (i.e. reliable serialization).  Spawning a thread-per-operation does not provide such a guarantee.

The right solution is to use a SharedThreadPool (or even plain nsThreadPool) with a single thread max.  It will shut down idle threads and restart them as needed.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

Attachment: Switch AsyncCubebOperation to a SharedThreadPool

Comment 2

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/919961c56977

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

I had to back this (and everything else from this push) out for causing various crashes on WinXP. They all seem to mention "winmm_stream_init" or "cubeb_winmm.c".

https://treeherder.mozilla.org/logviewer.html#?job_id=20232505&repo=mozilla-inbound
https://hg.mozilla.org/integration/mozilla-inbound/rev/e33cecf8d2a5

Comment 4

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/7da3fd66093c

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/7da3fd66093c