Bug 251977

Summary:	[GTK4] Enable threaded rendering again using 1 painting thread by default
Product:	WebKit	Reporter:	Carlos Garcia Campos <cgarcia>
Component:	WebKitGTK	Assignee:	Carlos Garcia Campos <cgarcia>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	bugs-noreply, mcatanzaro
Priority:	P2	Keywords:	Gtk
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=247628 https://bugs.webkit.org/show_bug.cgi?id=253108 https://bugs.webkit.org/show_bug.cgi?id=253953 https://bugs.webkit.org/show_bug.cgi?id=255923
Bug Depends on:
Bug Blocks:	210100

Description Carlos Garcia Campos 2023-02-09 01:05:43 PST

It seems the issues with threaded rendering were actually caused by using multiple painting threads, but we can still use a single thread to move the painting off the main thread.

Comment 1 Carlos Garcia Campos 2023-02-09 01:09:29 PST

Pull request: https://github.com/WebKit/WebKit/pull/9854

Comment 2 EWS 2023-02-09 04:09:21 PST

Committed 260059@main (4af5eb3490da): <https://commits.webkit.org/260059@main>

Reviewed commits have been landed. Closing PR #9854 and removing active labels.

Comment 3 Michael Catanzaro 2023-02-09 04:12:50 PST

Maybe should also change:

WTFLogAlways("The number of Nicosia painting threads is not between 1 and 8. Using the default value 4\n");
numThreads = 4;

Comment 4 Michael Catanzaro 2023-02-09 04:13:20 PST

Why can't WPE use one thread?

Comment 5 Carlos Garcia Campos 2023-02-09 04:32:07 PST

WPE doesn't enable threaded rendering by default.

Comment 6 Carlos Garcia Campos 2023-02-09 04:32:46 PST

The default is 4, for GTK we use 1 which is not the default value.

Comment 7 Michael Catanzaro 2023-02-09 04:56:28 PST

Just kind of weird for the "default" to be 4 when GTK uses 1 and WPE uses 0 and nothing uses 4. Whatever.

Comment 8 Michael Catanzaro 2023-02-28 13:59:52 PST

I think this was not safe to do after all. See bug #247628 and bug #253108.