[Python-Dev] Activating pymalloc (original) (raw)

Tim Peters tim.one@comcast.net
Fri, 15 Mar 2002 12:38:45 -0500

[M.-A. Lemburg, on PyMem_xxx still using malloc/free even when pymalloc is enabled]

Depends on how you define PyMem* ...

I could have guessed that .

If you are saying that these macros/functions are only intended to allocate memory blocks which Python will use, then it's probably OK to let pymalloc handle these as well.

If, for some reason, you intend to share the memory with some other process/DLL/whatever, then I'm not sure if this continues to work with pymalloc -- could be that the platform's malloc() uses flags/locks etc. to manage sharing. Just a thought, probably just FUD. ALAS, the only way to find out, is to try it.

It's not entirely FUD. At least on Windows, you can get into a state where using memory APIs "from the same family" can nevertheless end up using different heaps, and then passing addresses around is a nightmare when one DLL tries to free memory obtained in a different DLL. As a uniform way to spell "use the Python DLL's view of what 'the heap' is to allocate and free", PyMem_XXX serve a real purpose there. But extensions currently mix, e.g., PyMem_Malloc() with free() too.