Bug 197530 – [iOS Sim Debug] ASSERTION FAILED The atomic string comes from an other thread! Layout Test imported/w3c/web-platform-tests/workers/WorkerNavigator_appName.htm is a flaky crash

• Status: RESOLVED
• Resolution: FIXED
• Component: Tools / Tests

[Shawn Roberts]

The following layout test is flaky on iOS Simulator Debug

imported/w3c/web-platform-tests/workers/WorkerNavigator_appName.htm

Probable cause:

Test has been a flaky crash on its available history on the dashboard. Running the test by itself with 10000 iterations could not cause a crash.

When I use the test runners from the crashing runs I was able to narrow it down to two tests to reproduce this assertion:

run-webkit-tests imported/w3c/web-platform-tests/html/browsers/browsing-the-web/read-media/pageload-video.html imported/w3c/web-platform-tests/workers/WorkerNavigator_appName.htm --child-process 1 --ios-simulator --debug

When run in that order it will crash. Will crash with the oldest revision I can checkout which is r230021

Will attach full crash log to radar

Test was imported in https://trac.webkit.org/changeset/225593/webkit

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported%2Fw3c%2Fweb-platform-tests%2Fworkers%2FWorkerNavigator_appName.htm

Link to Assertion on bots:

https://build.webkit.org/results/Apple%20iOS%2012%20Simulator%20Debug%20WK2%20(Tests)/r244820%20(3520)/imported/w3c/web-platform-tests/workers/WorkerNavigator_appName-crash-log.txt

Local Crash Log clip:

Thread 32 Crashed:: WebCore: Worker
0   JavaScriptCore                	0x0000000114ed38d4 WTFCrash + 36
1   com.apple.WebCore             	0x00000007a833de49 WTF::AtomicStringImpl::add(WTF::AtomicStringTable&, WTF::StringImpl&) + 137
2   com.apple.WebCore             	0x00000007a833dd75 WTF::RefPtr<WTF::AtomicStringImpl, WTF::DumbPtrTraits<WTF::AtomicStringImpl> > WTF::AtomicStringImpl::addWithStringTableProvider<JSC::VM>(JSC::VM&, WTF::StringImpl*) + 85
3   com.apple.WebCore             	0x00000007a833dcbf JSC::Identifier::add(JSC::VM*, WTF::StringImpl*) + 63
4   com.apple.WebCore             	0x00000007a833dbb9 JSC::Identifier::Identifier(JSC::VM*, WTF::StringImpl*) + 73
5   com.apple.WebCore             	0x00000007a833db65 JSC::Identifier::Identifier(JSC::VM*, WTF::StringImpl*) + 37
6   com.apple.WebCore             	0x00000007a833d3c4 JSC::Identifier::fromString(JSC::ExecState*, WTF::String const&) + 68

[Radar WebKit Bug Importer]

<rdar://problem/50448285>

[Radar WebKit Bug Importer]

<rdar://problem/50448281>

[Chris Dumez]

Created attachment 368968 [details]
Patch

[Chris Dumez]

Created attachment 368969 [details]
Patch

[Geoffrey Garen]

Comment on attachment 368969 [details]
Patch

r=me

[Chris Dumez]

Comment on attachment 368969 [details]
Patch

Clearing flags on attachment: 368969

Committed r244927: <https://trac.webkit.org/changeset/244927>

[Chris Dumez]

All reviewed patches have been landed.  Closing bug.