Bug 228120

Summary:	Layer tree unfreezing and rendering update scheduling need to work together
Product:	WebKit	Reporter:	Simon Fraser (smfr) <simon.fraser>
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	bfulgham, sam, simon.fraser, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	Safari Technology Preview
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=228121

Description Simon Fraser (smfr) 2021-07-20 12:31:27 PDT

We currently rely on timers to trigger style updates/render tree updates, and this is necessary to trigger unfreezing the layer tree (via visually empty threshold). Ideally the style system would not have any of its own timers; it would just schedule rendering updates. However, TiledCoreAnimationDrawingArea::triggerRenderingUpdate() just bails if the layer tree is frozen.

We need to somehow harmonize layer tree freezing with rendering updates.

Comment 1 Simon Fraser (smfr) 2021-07-20 12:32:00 PDT

See rdar://75362363 and http://trac.webkit.org/changeset/272300/webkit

Comment 2 Sam Weinig 2021-07-21 16:57:12 PDT

(In reply to Simon Fraser (smfr) from comment #1)
> See rdar://75362363 and http://trac.webkit.org/changeset/272300/webkit

... and https://trac.webkit.org/changeset/280112/webkit

Comment 3 Radar WebKit Bug Importer 2021-07-27 12:32:20 PDT

<rdar://problem/81176458>