1050582 - Is on main thread assertion in GMPTimer can fail first call into GMPTimer is off main thread.

Status: RESOLVED FIXED

(Core :: Audio/Video, defect)

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

SetTimerOnMainThread() calls GMPChild::GetGMPTimers(), which calls the GMPTimerChild constructor on its first call. SetTimer is supposed to be only called on the main thread. But the check to ensure we're on the main thread is inside the GMPTimerChild::SetTimer() function. So if the first time SetTimer is called is off main thread, the GMPTimerChild ctor will run off main thread, and will fail.

SetTimerOnMainThread() should check that it's called on the main thread only.

Comment 1

[Chris Pearce [:cpearce (Not reading bugmail)]]

Attachment: Patch

Comment 2

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

Comment on attachment 8469687 [details] [diff] [review]
Patch

Review of attachment 8469687 [details] [diff] [review]:
-----------------------------------------------------------------

::: content/media/gmp/GMPPlatform.cpp
@@ +168,5 @@
>  
>  GMPErr
>  SetTimerOnMainThread(GMPTask* aTask, int64_t aTimeoutMS)
>  {
> +  if (!aTask || !sMainLoop || sMainLoop != MessageLoop::current()) {

comment that this is a "isChildMainThread()" test, or create such a function if you see it being reused

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

I added a IsOnChildMainThread() function:
https://hg.mozilla.org/integration/mozilla-inbound/rev/8c4a1b3a2a8b

Comment 4

[Nigel Babu [:nigelb]]

https://hg.mozilla.org/mozilla-central/rev/8c4a1b3a2a8b