Regression r252209: Layout Test fast/workers/worker-close-more.html is failing

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Aakash Jain]

The following layout test is failing on all the platforms: fast/workers/worker-close-more.html

Flakiness Dashboard:
https://results.webkit.org/?suite=layout-tests&test=fast%2Fworkers%2Fworker-close-more.html
https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fworkers%2Fworker-close-more.html


Probable cause:
It passed in r252208 and failed in r252210. Most likely a regression from r252209 https://trac.webkit.org/changeset/252209/webkit 
https://bugs.webkit.org/show_bug.cgi?id=203960 'Port MessagePort to the HTML5 event loop'

[Aakash Jain]

Sample failure:
https://ews-build.webkit.org/results/macOS-High-Sierra-Debug-WK1-Tests-EWS/r383034-6067-clean-tree/results.html

Diff:
 PASS: workerThreadCount = 0
 PASS: MessagePort multiple message test, received message: echo_ping1
+FAIL: The MessagePort message was dispatched after a JS fragment that called 'close()' exited.
+PASS: MessagePort messages were not delivered asfter close().
+DONE
 PASS: MessagePort messages were not delivered asfter close().
 DONE

[Radar WebKit Bug Importer]

<rdar://problem/57020558>

[Chris Dumez]

Looking.

[Chris Dumez]

I think WorkerMessagingProxy::workerGlobalScopeClosed() needs to be ported to the Event Loop too, or the ordering between posting a message and closing the worker global scope is no longer correct. I will confirm.

[Chris Dumez]

Created attachment 383130 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 383130 [details]
Patch

Clearing flags on attachment: 383130

Committed r252242: <https://trac.webkit.org/changeset/252242>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.