[Python-Dev] GC Proposal

[Adam Olsen]

On Sun, Jun 29, 2008 at 11:49 AM, "Martin v. Löwis" <martin at v.loewis.de> wrote:
>
>>> What precisely would be the "deleted" count? If it counts deallocations,
>>> is it relevant what generation the deallocated object was from?
>>> If so, how do you determine the generation? If not, wouldn't
>>>
>>> while 1:
>>>  x=[]
>>>
>>> trigger a full garbage collection fairly quickly?
>>
>> "deleted" means deallocated survivors.
>
> So when an object gets deallocated, how do you find out whether it
> survived a middle collection?

Reusing gc_refs for another flag.


>> I could imagine wanting to move survivors and deleted up to the first
>> generation, to give a stronger guarantee of how often it'd run, but
>> that'd require a much smaller deleted factor.
>
> This I don't understand. What is the first generation? Generation 0
> (i.e. the youngest objects)? Why would you want to move objects
> surviving a garbage collection back to the youngest generation? That
> totally defeats the purpose of generational garbage collection.
>
> Also, why would you want to move deleted objects anywhere? Their
> storage is reclaimed, and they don't occur in any list of objects.

Sorry, really poor wording on my part.  I meant to move the
*counters*, so that even the first generation qualifies as a
"survivor", and thus contributes to the "deleted" count.


-- 
Adam Olsen, aka Rhamphoryncus