FWIIW, I built GC 6.7 on a RHEL 3 (Opteron) system using ./configure --prefix=... --enable-redirect-malloc --enable- threads=posix --enable-thread-local-alloc make; make check; make install
Then, I tried running a few examples with 3 different, existing Python binaries each pre-loaded with the libgc.so library env LD_PRELOAD=.../libgc.so <python> .... One is Python 2.2.3 included in RHEL 3, one is a Python 2.5.1 build and is a Python 3.0a2 build, all 64-bit. All seemed to work OK. These are 3 existing Python binaries without any call to GC_INIT(). AFAICT, on Linux, GC_INIT is a no-op anyway. /Jean Brouwers On Dec 26, 7:14 am, MrJean1 <[EMAIL PROTECTED]> wrote: > 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 ofboehm-gcfor 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 theboehm-gcand 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 toboehm-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
