Algorithm for finalizing cycles (Re: [Python-Dev] Garbage collecting closures) (original) (raw)

Greg Ewing greg@cosc.canterbury.ac.nz
Tue, 15 Apr 2003 17:41:40 +1200 (NZST)

If the object having a finalizer doesn't support references to arbitrary other objects, then the application cannot make this object be part of a cycle.

It could make a subclass, though...

If you need a finalizer, always make two objects. One carries the resource being encapsulated, and nothing else. The other one is the object exposed to applications, which has a reference to the resource.

That actually sounds like a reasonable solution. I was thinking that del methods on anything referenced from the cycle would prevent collection, not just in the cycle itself, but as you point out, that's not the case. Given that, many of my objections go away.

I still may write that Executors module, though, it could be fun...

Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | A citizen of NewZealandCorp, a | Christchurch, New Zealand | wholly-owned subsidiary of USA Inc. | greg@cosc.canterbury.ac.nz +--------------------------------------+