[Python-Dev] PyObject_GC_UnTrack() no longer reliable in 2.7?

["Martin v. Löwis"]

Am 26.09.2010 12:54, schrieb Nick Coghlan:
> On Sat, Sep 25, 2010 at 9:20 AM, Tim Peters <tim.peters at gmail.com> wrote:
> [MvL]
>>> I think it would be possible to have two versions of
>>> _PyGC_REFS_UNTRACKED, one being, say, -5.
>>> _PyGC_REFS_UNTRACKED_AND_KEEP_IT_THAT_WAY would be what you get
>>> when you call PyObject_GC_UnTrack; the code to do automatic
>>> tracking/untracking based on contents would use some other
>>> new API (which would be non-public in 2.7.x).
>>
>> Looks like a promising idea!  gcmodule.c's IS_TRACKED macro would have
>> to change to check both states, and likewise the debug assert in
>> visit_reachable().
> 
> Given the intent is to restore the 2.6 state, perhaps it is the
> "UNTRACK_ALLOW_RETRACK" optimisation that should get the new special
> value? Other than that, MvL's suggestion looks like a good idea.

It would work either way, of course.

Regards,
Martin