1544434 - Canvas sometimes flashes black, on profiler.firefox.com

Status: RESOLVED WORKSFORME

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

Description

[Markus Stange [:mstange]]

Attachment: screen recording

Steps to reproduce:

1. On Windows 10, with WebRender enabled, go to https://perfht.ml/2DemxDI .
2. After the profile has loaded, press and hold the down arrow key on your keyboard.

Expected results:
The selection should move through the treeview and the canvas should update its highlighted areas based on the selection.

Actual results:
The canvas shows intermittent black flashing, see the screen recording.

This reproduces on a local build from revision ec1f3a922d56 with a fresh profile. I can not reproduce it on today's Nightly with my main profile. I have not tested other permutations.

Comment 1

[Markus Stange [:mstange]]

Attachment: about:support

Comment 2

[Sotaro Ikeda [:sotaro]]

On windows, we always use PersistentBufferProviderBasic instead of PersistentBufferProviderShared by Bug 1285271.

https://searchfox.org/mozilla-central/source/dom/canvas/CanvasRenderingContext2D.cpp#1411

TextureClient handling happens at CanvasClient2D::Update()
https://searchfox.org/mozilla-central/source/gfx/layers/client/CanvasClient.cpp#90

Comment 3

[Mayank Bansal]

Can you still reproduce this?

Comment 4

[Markus Stange [:mstange]]

I have not seen anything like this in quite some time.