[Python-Dev] update on memory leaks in 2.2

Tim Peters tim.one@home.com
Fri, 7 Dec 2001 12:35:21 -0500

[Fred L. Drake, Jr.]
>   Free'd weakref objects are stored in a free list, so it makes sense
> that these are labelled potential leaks.
>   We could either give up using a free list for these, or we could
> allocate blocks of these rather than allocating them individually.
> The latter would allow still better performance and would reduce the
> malloc overhead.

-0.  When we turn on pymalloc in 2.3, blocks will get allocated by magic,
and more space-efficiently than you're going to do by hand (it bites one
malloc overhead per 256KB).  pymalloc will likely be a little slower than a
wholly customized free list, but it will get all the memory benefit, and
unlike type-specific free lists allows memory to be recycled across types as
programs progress.

>  That change would be a higher risk than tossing the free list, and
> tossing it would be a higher risk than keeping it this close to the
> release.  But we're probably far enough away that any of the options
> (no free list, blocking allocation, and leaving it alone) are
> manageable.

There's another possibility:  as float objects do, add a module xxx_fini()
routine to clear the free list at shutdown.