Re: sending notifications in -dealloc

[Helge Hess]

Richard Frith-Macdonald wrote:
> Interesting ... GNUstep implements the documented behavior -
> retain increments the retain count (by calling 
> NSIncrementExtraReefCount(), release decrements it
> (by calling NSDecrementExtraRefCountWasZero()), and when it reaches zero 
> dealloc is called.

Well, this is the documented behaviour NSDecrementExtraRefCount*. The 
full implementation of -release actually isn't documented ?!

> So a retain within the dealloc will increment the retain count to 1, the 
> release will decrement it to
> zero, and dealloc will get called again.

Exactly.

> Presumably MacOS-X  actually differs slightly from the documented 
> behavior and does something like ignoring
> any retain/release when the retain count is zero?

Hm, I don't yet understand why the libFoundation implementation works (I 
can retain/release as much as I like). I need to think more about that.

> We could change GNUstep to work the same way for compatibility - though 
> I think it would be a little less
> efficient when built to user a map table for the extra reference counts.

I'll check the MacOSX implementation in detail this evening ;-)

Greetings
  Helge