On Thu, Dec 16, 2021 at 2:48 AM Petr Viktorin <[email protected]> wrote: > But does the sign bit need to stay intact, and do we actually need to > rely on the immortal bit to always be set for immortal objects? > If the refcount rolls over to zero, an immortal object's dealloc could > bump it back and give itself another few minutes. > Allowing such rollover would mean having to deal with negative > refcounts, but that might be acceptable.
FWIW, my original attempt at immortal objects (quite a while ago) used the sign bit as the marker (negative refcount meant immortal). However, this broke GC and Py_DECREF() and getting those to work right was a pain. It also made a few things harder to debug because a negative refcount no longer necessarily indicated something had gone wrong. In the end I switched to a really high bit as the marker and it was all much simpler. -eric _______________________________________________ Python-Dev mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/[email protected]/message/LJ2WVSUPJY2X3VVJW4EEEFNOBRJ7AB4V/ Code of Conduct: http://python.org/psf/codeofconduct/