Bug 229749 – [CoordinatedGraphics] Schedule rendering after setLayerTreeStateIsFrozen(false) in non-AC mode

• Component: WebKit2
• Status: CLOSED FIXED

[Tomoki Imai]

We should schedule another rendering when the setLayerTreeStateIsFrozen(false) is called in non-AC mode.

In some rare cases, the browser only shows the white page after the page transition, because the rendering is skipped while the layer tree is frozen and there was no guarantee that there is another rendering after setLayerTreeStateIsFrozen(false).

[Tomoki Imai]

Created attachment 436991 [details]
patch

Patch to schedule rendering when setLayerTreeStateIsFrozen(false) is called.

[Fujii Hironori]

Do you have a test case?

[Carlos Garcia Campos]

Comment on attachment 436991 [details]
patch

Wait, do we know for sure we are not in AC mode at that point?

[Carlos Garcia Campos]

Comment on attachment 436991 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=436991&action=review

> Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp:246
> +    else
> +        scheduleDisplay();

I think we should only call this if m_layerTreeHost is nullptr

[Tomoki Imai]

(In reply to Fujii Hironori from comment #2)
> Do you have a test case?

Unfortunately no. 
On PlayStation, the issue is reproducible with the specific webpage (and sorry, I cannot paste url here..) but WinCairo/GTK cannot reproduce the issue even with the same page.
I believe there is a chance where the GTK/WinCairo encounter the same issue, but it seems to depend on the timing.

[Tomoki Imai]

Created attachment 437000 [details]
patch

(In reply to Carlos Garcia Campos from comment #4)
> Comment on attachment 436991 [details]
> patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=436991&action=review
> 
> > Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp:246
> > +    else
> > +        scheduleDisplay();
> 
> I think we should only call this if m_layerTreeHost is nullptr

Thanks for pointing!
You're correct, I added "if (!m_layerTreeHost)" guard there.

[EWS]

[e-mail] does not have reviewer permissions according to https://raw.githubusercontent.com/WebKit/WebKit/main/Tools/Scripts/webkitpy/common/config/contributors.json.

Rejecting attachment 437000 [details] from commit queue.

[EWS]

Committed r281841 (241174@main): <https://commits.webkit.org/241174@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 437000 [details].

[Radar WebKit Bug Importer]

<rdar://problem/82617490>

[Tomoki Imai]

Thanks for your review and cq+!
(Sorry, I should not have r+)