2052894 - Webrender on Metal ANGLE crashes due to incorrect context type when attempting to migrate GPUs

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Jamie Nicol [:jnicol]]

We crash here due to aContext->mGL being a GLContextEGL rather than GLContextCGL.

This only occurs when running with the GPU process disabled, due to bug 2052891.

Long term we need to find an alternative to GPU switching on Metal ANGLE (something like "option B" in bug 1600178), but in the short term we're going to ship only on single-GPU devices. We should therefore check the context type before calling this function, avoiding the crash.

Comment 1

[Jamie Nicol [:jnicol]]

Attachment: Bug 2052894 - Avoid crash when attempting to migrate GPUs with ANGLE on macOS. r?#gfx-reviewers

With not yet landed patches to enable Metal ANGLE, we crash due to an
invalid GLContext cast when attempting to migrate GPUs. This only
occurs when the GPU process is disabled, due to bug 2052891.

Longer term, we need to find an alternative to GPU switching when
running on Metal ANGLE, as Metal does not have an equivalent API to
CGLSetVirtualScreen(). In the short term, however, we will keep Metal
ANGLE disabled on multi-GPU devices, so can simply avoid calling this
function for non-CGL contexts.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/df41d7417f64
https://hg.mozilla.org/integration/autoland/rev/e1ded6b37563
Avoid crash when attempting to migrate GPUs with ANGLE on macOS. r=gfx-reviewers,lsalzman

Comment 3

[amarc]

https://hg.mozilla.org/mozilla-central/rev/e1ded6b37563