Weak reference support for codon native objects

[lowsfer]

I'm trying to use codon to accelerate a python project. But I wonder if there is an alternative of python weakref / C++ weak_ptr for Codon native objects. It's a resource-management components requiring weak ref for: 1. non-owning observer; 2. breaking circular reference.

Does codon support this? In my case, the weak reference is used purely internally, inside the component. And only a few specified classes needs it. In CPython, I enable weakref support by adding __weakref__ into __slots__.

[lowsfer]

Oh, I just realized that Codon uses tracing GC, not ref-count, so there is no deterministic cleanup even if user code has no ref cycles. Also, __del__ is silently ignored.

And I found this in the official roadmap "Optional alternative memory management modes like reference counting". Does that mean we will eventually have deterministic cleanup when there is no ref cycles? Will __del__ be supported when we have that?

[arshajii]

Hi @lowsfer, actually __del__() should work with Codon, but there is a regression that's preventing the registration of finalizers with the GC. This will be fixed in the upcoming release.