[Python-Dev] cpython: Issue #3329: Add new APIs to customize memory allocators

[Antoine Pitrou]

On Sat, 15 Jun 2013 03:54:50 +0200
Victor Stinner <victor.stinner at gmail.com> wrote:
> The addition of PyMem_RawMalloc() is motivated by the issue #18203
> (Replace calls to malloc() with PyMem_Malloc()). The goal is to be
> able to setup a custom allocator for *all* allocation made by Python,
> so malloc() should not be called directly. PyMem_RawMalloc() is
> required in places where the GIL is not held (ex: in os.getcwd() on
> Windows).

We already had this discussion on IRC and this argument isn't very
convincing to me. If os.getcwd() doesn't hold the GIL while allocating
memory, then you should fix it to hold the GIL while allocating memory.

I don't like the idea of adding of third layer of allocation APIs. The
dichotomy between PyObject_Malloc and PyMem_Malloc is already a bit
gratuitous (i.e. not motivated by any actual real-world concern, as
far as I can tell).

As for the debug functions you added: PyMem_GetRawAllocators(),
PyMem_SetRawAllocators(), PyMem_GetAllocators(), PyMem_SetAllocators(),
PyMem_SetupDebugHooks(), _PyObject_GetArenaAllocators(),
_PyObject_SetArenaAllocators(). Well, do we need all *7* of them? Can't
you try to make that 2 or 3?

Regards

Antoine.