[issue40255] Fixing Copy on Writes from reference counting

[Carl Meyer]

Carl Meyer <carl at oddbird.net> added the comment:

> This may break the garbage collector algorithm that relies on the balance between strong references between objects and its reference count to do the calculation of the isolated cycles.

I don't think it really breaks anything. What happens is that the immortal object appears to the GC to have a very large reference count, even after adjusting for within-cycle references. So cycles including an immortal object are always kept alive, which is exactly the behavior one should expect from an immortal object.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue40255>
_______________________________________