1352475 - Ensure critical notes on the render thread actually get saved in time

Status: NEW

(Core :: Graphics: WebRender, defect, P3)

Description

[Kartikaya Gupta (email:[e-mail])]

In bug 1350986 I added some calls to gfxCriticalNote to diagnose webrender startup crashes. However those notes don't appear in crash reports. I suspect what is happening is that the critical note is created on the GPU Process/RenderThread, which means it gets reposted as a runnable to the GPU Process/main thread at [1]. Meanwhile, the RenderThread unwinds back to the compositor thread which then crashes. This effectively means there is a race between the main thread actually saving that critical note (by sending it over PGPU to the parent process) and the compositor thread crashing at [2] because api is null, and this might explain the missing critical note.

[1] http://searchfox.org/mozilla-central/rev/7419b368156a6efa24777b21b0e5706be89a9c2f/gfx/thebes/gfxPlatform.cpp#355
[2] http://searchfox.org/mozilla-central/rev/7419b368156a6efa24777b21b0e5706be89a9c2f/gfx/layers/ipc/CompositorBridgeParent.cpp#1599

Comment 1

[Kartikaya Gupta (email:[e-mail])]

I wrote a patch and pushed it to try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=fd1d1a2f7bfba6eb9778aa6cdcd83ef58f585e2b

Hopefully using that try build I can generate some crash reports and see what pops out.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Unassigning things I'm not really working on