Bug 36514 – [v8] Failed assertion in V8Proxy::setDOMException() if worker is shutting down

• Component: WebCore JavaScript
• Status: RESOLVED FIXED

[Andrew Wilson]

The SharedWorkerHttpAuth test results in the worker being shutdown in the middle of an importScript() call, which results in an exception being generated and passed to V8Proxy::setDOMException().

There's a race condition that occurs - if WorkerScriptController::forbidExecution() is invoked before the importScript() call returns and calls setDOMException(), then a failed assertion happens.

It seems that this line in setDOMException() yields an empty exception object:

        exception = toV8(EventException::create(description));

Which causes this to fail further on in the function.

    ASSERT(!exception.IsEmpty());

I suspect the issue is that toV8() can't create an object if the worker context is shutting down.

I think the right thing to do is to get rid of that assertion, and instead have a failed assertion in the default: case statement (failing if setDOMException() is passed an unknown exception type), and then quietly return without throwing the exception.

[Andrew Wilson]

Created attachment 51516 [details]
Patch

[WebKit Review Bot]

Attachment 51516 [details] did not pass style-queue:

Failed to run "WebKitTools/Scripts/check-webkit-style" exit_code: 1
WebCore/ChangeLog:8:  Line contains tab character.  [whitespace/tab] [5]
WebCore/ChangeLog:12:  Line contains tab character.  [whitespace/tab] [5]
Total errors found: 2 in 2 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Dmitry Titov]

Comment on attachment 51516 [details]
Patch

r=me 

Please change tabs to spaces, per style bot note.

It is a good rule to have [v8] in front of title of the bug if the change only affects v8-specific files. Some people use it to immediately see if the change is relevant or not relevant for them (having filters etc). I've changed the bug title.

[Andrew Wilson]

Created attachment 51527 [details]
Patch

[Andrew Wilson]

Created attachment 51528 [details]
Patch

[Dmitry Titov]

Comment on attachment 51528 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 51528 [details]
Patch

Clearing flags on attachment: 51528

Committed r56461: <http://trac.webkit.org/changeset/56461>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.