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Efficient data flow between orthogonal C extensions?

Pierre Schnizer P.Schnizer at nospam.gsi.de
Fri Jun 6 03:11:48 EDT 2003 
mlh at furu.idi.ntnu.no (Magnus Lie Hetland) writes:
> What am I doing wrong?
Now you also have to wrap the callback which has to have the signature:
void callback(char *);

This will result in a "variable" 0x......._p_f_p_char__void, basically the
pointer to the function and the adress. Swig uses the appendix
_p_f_p_char__void to "typecheck" the input. 


I uploaded an example at:
	http://www.itp.tu-graz.ac.at/~pierre/swig_example.tar.gz

I added also the swig generated files, so you can run the test.
You will need swig1.3 to generate the interface files yourself. Note that the
shared object must be named _foo.so

Here a short summary. I changed the signature of the functions. The return
values are considered as error flags. Also a void * pointer was included for
additional arguments. If you are interested I could show you how to convert
them to Py exceptions using typemaps. 

I need a struct to pass the callback and its argument to the python function.
Swig can generate the constructor and destructor aided with the extend
structure. 
In foo.c you will find the c callback "bar" and the helper
function "py_bar". 

test_foo.py executes the functions. 

py_bar needs to get a handle for the PyObject to call. 


Yours sincerely 
	Pierre
> -- 
> Magnus Lie Hetland                "In this house we obey the laws of
> http://hetland.org                 thermodynamics!"    Homer Simpson
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