1323241 - Don't report that cells are gray when we don't know

Status: RESOLVED FIXED

(Core :: JavaScript: GC, defect)

Description

[Jon Coppeard (:jonco)]

Attachment: gray-marking-validity

The gray marking state can become invalid if we OOM while unmarking gray.  In that case we could report things as gray when they are not.  I guess that makes this s-s since the cycle collector may consider them for collection incorrectly.

This patch changes the API functions to just return false if the gray marking state is invalid.

I moved the validity flag from GCRuntime to the shadow runtime so that we could carry on inling the IsMarkedGray checks.  I'm not sure that's essential.

Comment 1

[Steve Fink [:sfink] [:s:]]

Comment on attachment 8818324 [details] [diff] [review]
gray-marking-validity

Review of attachment 8818324 [details] [diff] [review]:
-----------------------------------------------------------------

Finally noticing the review requests buried in my secure bugmail. Sorry for the delay. Looks good to me.

Comment 2

[Ryan VanderMeulen [:RyanVM]]

Backed out from inbound for causing frequent GC crashes as noted in bug 1329359.
https://hg.mozilla.org/integration/mozilla-inbound/rev/d57eaa1f1bd99363e66fc1fe9359c6189acbe26d

https://treeherder.mozilla.org/logviewer.html#?job_id=66966501&repo=mozilla-inbound
https://treeherder.mozilla.org/logviewer.html#?job_id=66975242&repo=mozilla-inbound
https://treeherder.mozilla.org/logviewer.html#?job_id=66981825&repo=mozilla-inbound
https://treeherder.mozilla.org/logviewer.html#?job_id=66969499&repo=mozilla-inbound
https://treeherder.mozilla.org/logviewer.html#?job_id=66966777&repo=mozilla-inbound
https://treeherder.mozilla.org/logviewer.html#?job_id=66965883&repo=mozilla-inbound

etc

Comment 3

[Jon Coppeard (:jonco)]

Re-landed:

https://hg.mozilla.org/integration/mozilla-inbound/rev/9b9d0cfd3fa3c93cf8a9a97c603176ece0b266e9

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/9b9d0cfd3fa3

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Should we take this on Beta as well?

Comment 6

[Jon Coppeard (:jonco)]

Attachment: bug1323241-beta

Approval Request Comment
[Feature/Bug causing the regression]: Since forever.
[User impact if declined]: Possible crashes / spurious assertion failures in testing.
[Is this code covered by automated tests?]: Yes.
[Has the fix been verified in Nightly?]: Yes.
[Needs manual test from QE? If yes, steps to reproduce]: No.
[List of other uplifts needed for the feature/fix]: None.
[Is the change risky?]: No.
[Why is the change risky/not risky?]: It's a fairly simple change to report GC things as gray less often.  It's been on m-c since 9th Jan.
[String changes made/needed]: None.

Comment 7

[Julien Cristau [:jcristau]]

Comment on attachment 8833269 [details] [diff] [review]
bug1323241-beta

gc fix for beta52

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/4ed3524d4d66

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr52/rev/4ed3524d4d66