Aaron Klotz f06eb6d4d5 Bug 1433046: Use WeakReferenceSupport::StabilizeRefCount instead of regular kung-fu death grips when aggregating; r=Jamie ...

This fix is completely speculative, but I have strong reason to believe that
we are having lifetime issues, and that refcount stabilization might be coming
into play.

The situation is this:

Suppose we're aggregating an object, so we pass |this| as the outer IUnknown.
The inner object might perform AddRef() and Release() on |this| during its
initialization.

But if we're in the process of creating the outer object, that refcount might
not yet have been incremented by 1, so the inner object's invocation of the
outer object's Release() could trigger a deletion.

The way around this is to temporarily bump the refcount when aggregating another
object. The key, though, is to not do this via AddRef() and Release(), but by
direct maniuplation of the refcount variable, so that we don't trigger any of
the self-deletion stuff.

MozReview-Commit-ID: 3WA2AJvb6jY

2018-01-25 13:45:21 -07:00

5.5 KiB

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