1963019 - Add a way of verifying post barriers

Status: RESOLVED FIXED

(Core :: JavaScript: GC, task, P2)

Description

[Jon Coppeard (:jonco)]

The original post barrier verifier was removed in bug 1161353 because it wasn't catching many bugs and was cumbersome to maintain. However I now find myself trying to find a presumed missing post barrier and wishing we had this feature.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1963019 - Add a way of verifying post barriers r?sfink

This adds a zeal mode that triggers minor GC periodically and then walks the
heap looking for pointers into the nursery that should have been updated. It's
a slow but simple approach.

I tested this by changing CyclicModuleFields::metaObject to be PreBarriered
rather than HeapPtr and this caught it when running the jittests.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Bug 1963019 - Hook up the post barrier verification mode to the existing testing function r?sfink

I realised we had a function to enable/disable this before the previous
impelementation was removed. Update it to use the new implementation.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ca706c73b207
Add a way of verifying post barriers r=sfink
https://hg.mozilla.org/integration/autoland/rev/71ed4365f9d2
Hook up the post barrier verification mode to the existing testing function r=sfink

Comment 4

[amarc]

https://hg.mozilla.org/mozilla-central/rev/ca706c73b207
https://hg.mozilla.org/mozilla-central/rev/71ed4365f9d2