It depends on how the GC inside the extension is built. If it is a drop-in replacement for malloc, then GC *must* be loaded and initialized upfront if possible. There is no need to memcpy anything between Python and the extension.
However, if GC does not replace malloc, etc., then GC-ed memory is only used within the extension. GC_INIT can be called when the extension is loaded and memcpy-ing between Python and the extension is mandatory. There are other details to consider. For example, on some platforms, GC *must* be initialized from the main executable. That may preclude both scenarios, altogether. /Jean Brouwers On Dec 25, 7:35 pm, Andrew MacIntyre <[EMAIL PROTECTED]> wrote: > malkarouri wrote: > > Is it possible to write a Python extension that uses the Boehm garbage > > collector? > > I have a C library written that makes use of boehm-gc for memory > > management. To use that, I have to call GC_INIT() at the start of the > > program that uses the library. Now I want to encapsulate the library > > as a CPython extension. The question is really is that possible? And > > will there be conflicts between the boehm-gc and Python memory > > management? And when should I call GC_INIT? > > It probably should be possible with some caveats: > - memory allocated by Python is never passed into the library such that > it also ends up being subject to boehm-gc; > - memory allocated by the library is never used by Python objects. > > So memcpy()ing between library allocated and Python allocated memory > would seem to be a way to achieve this. > > I would call GC_INIT in the extension's import routine > (init<module_name>()) for a C extension, and immediately after loading > the library if using ctypes. > > -- > ------------------------------------------------------------------------- > Andrew I MacIntyre "These thoughts are mine alone..." > E-mail: [EMAIL PROTECTED] (pref) | Snail: PO Box 370 > [EMAIL PROTECTED] (alt) | Belconnen ACT 2616 > Web: http://www.andymac.org/ | Australia -- http://mail.python.org/mailman/listinfo/python-list