Bug 253868 – REGRESSION(261559@main) [Win] js/ShadowRealm-iframe-detach.html is randomly timing out

• Component: WebCore JavaScript
• Status: REOPENED

[Fujii Hironori]

REGRESSION(261559@main) [Win] js/ShadowRealm-iframe-detach.html is randomly timing out

After 261559@main (bug#175336) disabled USE_CF for WinCairo, the following tests are randomly timing out.

js/ShadowRealm-iframe-detach.html
js/ShadowRealm-importValue.html

The timeout is more likely happening in the first time. --run-singly switch is useful to reproduce the timeout.
  
> python.exe ./Tools/Scripts/run-webkit-tests --wincairo --debug js/ShadowRealm-iframe-detach.html --iterations=30 -v --no-retry-failures --run-singly

The reproduction rate is 8/30.

[Fujii Hironori]

Created attachment 465428 [details]
WIP patch

This patch resolves the problem. I don't understand reportAbandonedObjectGraph at all.

[Fujii Hironori]

Test gardening by 261667@main.

[Fujii Hironori]

If I keep 'realm' in the 'window' object, the timeout problem doesn't happen. The realm is garbage collected!?

diff --git a/LayoutTests/js/ShadowRealm-iframe-detach.html b/LayoutTests/js/ShadowRealm-iframe-detach.html
index d4651f0897d2..1c0e3721705b 100644
--- a/LayoutTests/js/ShadowRealm-iframe-detach.html
+++ b/LayoutTests/js/ShadowRealm-iframe-detach.html
@@ -22,6 +22,7 @@
  frame.onload = async () => {
      debug(frame);
      let realm = frame.realm;
+     window.xxx = realm;
      debug("detaching iframe");
      document.getElementsByTagName("iframe")[0].remove()
      $vm.gc();

[Fujii Hironori]

Pull request: https://github.com/WebKit/WebKit/pull/11639

[Fujii Hironori]

Created attachment 465511 [details]
patch to reproduce the timeout for Mac port

This timeout is reproducible with Mac port if I apply this patch to take the garbageCollectOnNextRunLoop code path.

> Tools/Scripts/run-webkit-tests --debug js/ShadowRealm-iframe-detach.html --iterations=30 --no-retry-failures --run-singly

The reproduction rate is 25/30.

[Radar WebKit Bug Importer]

<rdar://problem/106974546>

[EWS]

Committed 262136@main (6c72fadf79d3): <https://commits.webkit.org/262136@main>

Reviewed commits have been landed. Closing PR #11639 and removing active labels.

[Fujii Hironori]

The test is still timing out on a Buildbot tester even after 262136@main. Reopened.

https://results.webkit.org/?suite=layout-tests&test=js%2FShadowRealm-importValue.html

[Fujii Hironori]

It's a wrong URL.

js/ShadowRealm-iframe-detach.html is still timing out.
https://results.webkit.org/?platform=wincairo&suite=layout-tests&test=js%2FShadowRealm-iframe-detach.html

js/ShadowRealm-importValue.html and http/tests/misc/iframe-shadow-realm.html doesn't seem to time out after the change.
https://results.webkit.org/?platform=wincairo&suite=layout-tests&suite=layout-tests&test=js%2FShadowRealm-importValue.html&test=http%2Ftests%2Fmisc%2Fiframe-shadow-realm.html