1687002 - The incremental marking validator doesn't work

Status: RESOLVED FIXED

(Core :: JavaScript: GC, defect)

Description

[Jon Coppeard (:jonco)]

While working on refactoring the Chunk layout I noticed that the marking validator doesn't actually do anything. Although the ChunkBitmap methods to check mark bits are not static, they don't use |this| but find the bitmap from the cell pointer given. This means the marking validator effectively compares each mark bitmap against itself.

This is the code in question: https://searchfox.org/mozilla-central/source/js/src/gc/Verifier.cpp#704-726

This stems from the change to define GetGCThingMarkWordAndMask in HeapAPI.h so that it could be inlined externally to the engine.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1687002 - Fix incremental marking validator r?sfink

This patch makes ChunkBitmap::getMarkWordAndMask into an instance method so that the uses in MarkingValidator access the correct bitmap.

Depends on D101778

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/abdfa91676ff
Fix incremental marking validator r=sfink

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/abdfa91676ff