Callback help

Hi all,

I apologize if this has already been answered or if it's a dumb question...=
I tried looking through the archives and haven't found =

anything similar so far.  I'm trying to wrap a C API that makes use of =

callbacks, and I looked at the cheesefinder callback demo code in the =

Pyrex distribution.  If I write my code to match the cheesefinder =

example, it works fine.  However, it appears that the cheesefinder =

example passes the Python function pointer as the user_data itself, but =

what if I want to ALSO pass user data to my Python callback?   I should =

point out that it's been several years since I did any serious C coding =

(which is why I'm trying to wrap the thing in Python), so I'm hoping =

it's just a simple n00b-level  solution.   I tried various permutations =

of using PyCObject_AsVoidPtr instead of just casts, but to no avail.  =

Essentially it compiles fine, but Bus Errors/Seg Faults when it goes to cal=
l the python callback.  Here's the gist of what I tried.

Thanks in =

advance,
Dale

cdef extern from "cheesefinder.h":
    =

ctypedef void (*cheesefunc)(char *name, void *user_data)
    void =

find_cheeses(cheesefunc user_func, void *user_data)

ctypedef =

struct my_cheese_data:
       void *py_callback
       void =

*py_data

def find(f, data):
    cdef my_cheese_data user_data
    my_cheese_data.py_callback =3D <void *>f
    =

my_cheese_data.py_data =3D <void *>data

    =

find_cheeses(super_callback, <void*>&user_data)
    =

cdef void callback(char *name, void *f):
    (<object>f)(name)

cdef void super_callback(char *name, void *cheese_data):
    cdef void *f
    cdef void *user_data

    f =3D <void =

*>cheese_data.py_callback
    user_data =3D <void =

*>cheese_data.py_data
       (<object>f)(name, user_data)


      =