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

[Greg Ewing]

> 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	   +--------------------------------------+