645442 - XPCWrappedNative::FlatJSObjectFinalized manipulates map without acquiring map lock

Status: RESOLVED FIXED

(Core :: XPConnect, defect)

Description

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

XPCWrappedNative::FlatJSObjectFinalized has the following code (which I noticed while further investigating bug 629610 comment 312):

        GetScope()->GetWrappedNativeMap()->Remove(this);

This seems to be the one of the very few things that manipulates a Native2WrappedNativeMap without acquiring the map lock.  (I was noticing because I was comparing the code there to ~XPCWrappedNative, which is very similar, but does acquire the map lock.)

The other things (which worry me somewhat less) are:

XPCWrappedNativeScope::MarkAllWrappedNativesAndProtos, XPCWrappedNativeScope::ASSERT_NoInterfaceSetsAreMarked, and XPCWrappedNativeScope::SweepAllWrappedNativeTearOffs, which all run under the JSGC_FINALIZE_END callback (though maybe that doesn't really help?).

XPCWrappedNativeScope::DebugDump, which is #ifdef DEBUG.

Comment 1

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

The patch I put in bug 629610 fixes this.