Mailman 3 September 2007 - capi-sig

Announcing project PyBindGen
by Gustavo Carneiro Sept. 25, 2007

Sept. 25, 2007

Hello all, I'd like to announce a new project for producing python extensions, called PyBindGen. It follows a radical new path for Python bindings generation: it is itself written in (gasp!) Python! And it does not even use C++ templates at all! :-) The project is young but has been slowly developed for a few months now, so it has already reached a point where it is useful for many tasks. For now, it has only a Python interface. No interface description file or header scanning supported yet. It also has been focused more on C++ code for now, although it was designed to also support pure C from the start. More information in: https://launchpad.net/pybindgen/ -- Gustavo J. A. M. Carneiro INESC Porto, Telecommunications and Multimedia Unit "The universe is always one step beyond logic." -- Frank Herbert

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capi-sig missing in http://www.python.org/community/sigs/
by Gustavo Carneiro Sept. 25, 2007

Sept. 25, 2007

Hi, This list, capi-sig, is not listed in the list of SIGs in python.org: http://www.python.org/community/sigs/ Just so you know. -- Gustavo J. A. M. Carneiro INESC Porto, Telecommunications and Multimedia Unit "The universe is always one step beyond logic." -- Frank Herbert

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Threading
by Pablo Yabo Sept. 9, 2007

Sept. 9, 2007

Hello, I want to embed Python in an application and use an API of the application from Python. The application uses a library that creates several threads and I the users of the application will write Python scripts handling this events. The problem is that I having problems with threads. I saw that I have to PyEval_InitThreads and then PyThreadState_New and PyThreadState_Swap from the new thread but this way to solve the problem doesn't work for me because I need to let 2 or more threads run at the SAME time. The interpreter lock doesn't let them run at the same time so I'm looking for another solution. I saw Py_NewInterpreter and I tried to use it but it doesn't work if I don't keep the lock. Can anyone help me to solve this issue or tell me 'Forget it!'? Thanks on advance, Pablo Yabo -- http://www.nektra.com

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_PyObject_GC_Malloc
by Hrvoje Niksic Sept. 4, 2007

Sept. 4, 2007

Does anyone know why the functionality of _PyObject_GC_Malloc isn't available in a public function? I need to create a GCable object whose size is computed at instance creation time, but which is not a classic VAR_ object (it doesn't have an ob_size field). Currently I call _PyObject_GC_Malloc directly, but I don't like the dependence on a private API. If there is no good reason for keeping gc_malloc private, I'd like to propose on python-dev that it be made public as PyObject_GC_Malloc.

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Extension Problem
by Ali Alhakim Sept. 4, 2007

Sept. 4, 2007

Hello! I'm quite new to Python and definitely a beginner in implementing Python extensions in C/C++. I've followed the structure given in the formal Python documentation to write the following code block: =========== //cmatmod.c #include static unsigned int eigenvect_calc(double *min_eps) { return 5; } static PyObject *cmat_eigv(PyObject *self, PyObject *args) { double *min_eps; unsigned int m; if(!PyArg_ParseTuple(args, "d", &min_eps)) return NULL; m=eigenvect_calc(min_eps); return Py_BuildValue("I", m); } static PyMethodDef cmat_methods[]= { { "eigenvect", cmat_eigv, METH_VARARGS, "Comment"},{NULL, NULL, 0, NULL} }; void initcmat(void) { (void) Py_InitModule("cmat", cmat_methods); } =========== I have succeeded to build and install this extension using disutils package in the setup.py file below: =========== from distutils.core import setup from distutils.extension import Extension setup(name='eigenvect', version='1.0', ext_modules=[Extension('cmat', ['cmatmod.c'])], ) ========== But when I try to call eigenvect(3.0) from Python I would receive a core dump: ========== 6 [main] python 2336 _cygtls::handle_exceptions: Error while dumping state (probably corrupted stack) Segmentation fault (core dumped) ========== My question is what is wrong with the extension code above? Is it something with reference counting? I don't know which method is suitable for debugging extension codes. I've tried gdb but I didn't understand the debug information: ========== (gdb) >>> eigenvect(4.0) Program received signal SIGSEGV, Segmentation fault. ---Type to continue, or q to quit--- 0x6abb248e in libpython2!PyEval_EvalFrameEx () from /usr/bin/libpython2.5dll (gdb) ========== /best regards Gå in och titta på nätets roligaste filmer just nu eller ladda upp ditt eget bidrag på Spray Crazy. http://crazy.spray.se/

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