[snake-farm] Re: [Python-Dev] Snake farm (original) (raw)

Martin v. Loewis martin@v.loewis.de
11 Nov 2002 13:43:57 +0100

Marc Recht <marc@informatik.uni-bremen.de> writes:

#0 0x080779c0 in PyObjectFree (p=0x800) at Objects/obmalloc.c:713 #1 0x080e00a0 in functioncall (func=0x82641ec, arg=0x8258b8c, kw=0x826bbdc) at Objects/funcobject.c:481

This looks like it is getting difficult. 0x800 is surely a garbage pointer, so it is not surprising that pymalloc crashes when it sees that pointer.

Now, the question is: where does that pointer come from? This should be from funcobject.c:457, which says

    k = PyMem_NEW(PyObject *, 2*nk);

Unless I'm mistaken, this expands to malloc(). Can you please try to confirm that malloc indeed return this 0x800? If so, it looks like the C library's malloc got confused. We would then need to find out why that happens.

If you can't come up with a debugging strategy, I recommend that you try out Tim's suggestion (ie. build with optimizations disabled). In addition, I also suggest that you build with threads disabled. Of course, if you then cannot reproduce the problem anymore, this is little proof that the problem has to do with optimization, or threads :-(

Regards, Martin