using autorelease in apple's CF

[Alexey Perevalov]

Hello gnustep developers!

I'm interesting in using autorelease pool from apple's CF (http://www.opensource.apple.com/source/CF/, http://www.opensource.apple.com/source/CFNetwork/).
In gnustep implementation autorelease message ([(object) autorelease]) for allocated object is sending. I'm talking about svn.gna.org/svn/gnustep/libs/base/trunk, whole implementation was made on objective C. But CF published on opensource.apple.com written on C.
So the question how they are putting objects into autorelease pool? My assumption, somewhere should be objc_autorelease invocation, but where?

BR
Alexey