multi-threaded c++ callback problem

[Ames Andreas]

> -----Original Message-----
> From: python-list-bounces+andreas.ames=comergo.com at python.org 
> [mailto:python-list-bounces+andreas.ames=comergo.com at python.or
> g] On Behalf Of pydev
> Sent: Tuesday, April 11, 2006 9:23 PM
> Subject: multi-threaded c++ callback problem
> 
> void pyCallEventCallback(  CALL hCall, 
>                                     LINE hLine, 
>                                     CALLSTATE_MAJOR eMajor,
>                                     CALLSTATE_MINOR eMinor,  
>                                     PyObject* def )
> {
>     if( !PyCallable_Check( def ) ) 
>     {
>         PyErr_SetString( PyExc_TypeError, "Need a callable object!" );
>         return;
>     }
>     printf( "EventCallback hCall: %i, hLine: %i, eMajor: %i, 
> eMinor: %i\n", hCall, hLine, eMajor, eMinor);
>     PyObject* arglist = Py_BuildValue("(iiii)", hCall, hLine, 
> eMajor, eMinor);
>  
>     // if i comment out next  line it works!
>     PyEval_CallObject( def, arglist ); 
>  
>     Py_XDECREF(arglist);    
> }
> //-----------------------------------------------------------//

Wild guess because of lack of context:

It's a race condition because you haven't acquired the GIL before calling pyCallEventCallback.  You can do so by using PyEval_SaveThread and friends.  You have to make sure to call PyEval_InitThreads somewhere, e.g. when embedding from within the interpreter initialisation boilerplate, when extending for instance from within the extension module initialisation.


cheers,

aa

-- 
Andreas Ames | Programmer | Comergo GmbH |
Voice:  +49 69 7505 3213 | ames AT avaya . com