Ubuntu
compiz package

  1. Bug #758248
  2. Comment #21

Comment 21 for bug 758248

Revision history for this message
Daniel van Vugt (vanvugt) wrote :

I've lost count of the leaks in unity I've looked at today (to fix bug 769957). My plan is to only fix what I need to to resolve that bug and leave the others to this bug (or others).

The most common cause I've found is total misuse of the nux::Object referencing model throughout the unity code. So often a floating reference is created (one not marked as owned via SinkReference etc) with refcount==1, and the author just calls UnReference which will always fail in that situation. Because nux::Object::UnReference is actually designed to fail in that situation (!)

I think the root cause really is the design of nux::Object. It is far too confusing and dangerous for an object with refcount==1 to fail UnReference. Programmers really don't expect that and it is not obvious why initially (if you even bother to check the return value of UnReference).

For now in bug 769957, I'm just working with the nux API as it is and changing only unity to minimize potential side effects. But it feels inelegant...

Would it ever be safe to make nux::Object::UnReference behave how people expect it should?