TestWebKitAPI.WebKit.CustomDisplayName is a flaky timeout

[Ryan Haddad]

After a fix for flaky failures landed in https://trac.webkit.org/changeset/260971/webkit, TestWebKitAPI.WebKit.CustomDisplayName appears to now be a flaky timeout on macOS Release bots

https://build.webkit.org/builders/Apple-Catalina-Release-WK1-Tests/builds/5418

https://results.webkit.org/?suite=api-tests&suite=api-tests&test=TestWebKitAPI.WebKit.CustomDisplayName&test=TestWebKitAPI.WebKit.DefaultDisplayName

[Radar WebKit Bug Importer]

<rdar://problem/62734802>

[Alex Christensen]

Created attachment 398255 [details]
Patch

[EWS]

Committed r261090: <https://trac.webkit.org/changeset/261090>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 398255 [details].

[Alex Christensen]

This test still times out on the bots sometimes after this fix.

[Alex Christensen]

Created attachment 398404 [details]
Patch

[EWS]

Committed r261112: <https://trac.webkit.org/changeset/261112>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 398404 [details].

[Alex Christensen]

Reopening to attach new patch.

[Alex Christensen]

Created attachment 398425 [details]
Patch

[Chris Dumez]

Comment on attachment 398425 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=398425&action=review

> Source/WebKit/WebProcess/WebPage/Cocoa/WebPageCocoa.mm:301
> +    dispatch_async(dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0), makeBlockPtr([completionHandler = WTFMove(completionHandler)] () mutable {

I think the issue is that dispatch_get_global_queue() returns a concurrent queue, not a serial queue, so ordering is not guaranteed.

[Alex Christensen]

Created attachment 398429 [details]
Patch

[EWS]

Committed r261145: <https://trac.webkit.org/changeset/261145>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 398429 [details].

[Alex Christensen]

results.webkit.org indicates this is fixed!  hooray!