Hi all, We are having problems when creating numeric arrays in C extensions under windows. We narrowed the problem down to a very simple example (shown below) where we simply allocate some memory, create a Numeric array using PyArrayFromDimsAndData. If we call that function as soon as we delete the returned array the python interpreter crashes as it tries to free self->data. If we do not the the OWN_DATA flag in the array it works fine but we have a memory leak. We tried this using both release and Debug versions of Python1.5.2, and Numeric 17.1.1. I have been using this mechanism under Unix for a long time and have not had this problem before ! Using the same extension and test under unix works fine. Has something changed ? Any help is welcome ... Thank you I join the two files we are using. bug.c : a C module that create an array numeric with the flags set to own_data, so when the array is garbage collected, the memory is free. ################# bug.c##################################################### #ifdef WIN32 #include <stdlib.h> #include <malloc.h> #endif #include "Python.h" #include "arrayobject.h" static PyObject* createArray(PyObject* self, PyObject* args) { int *dims; float *data; PyArrayObject *out; dims = (int *)malloc(2 * sizeof(int)); dims[0] = 500; dims[1] = 2; data = (float *)malloc(100000 * sizeof(float)); out = (PyArrayObject *)PyArray_FromDimsAndData(2, dims, PyArray_FLOAT, (char *)data); if (!out) { PyErr_SetString(PyExc_RuntimeError, "Failed to allocate memory for normals"); return NULL; } out->flags |= OWN_DATA; /*so we'll free this memory when this array will be garbage collected */ return (PyObject *)out; } static PyMethodDef bug_methods[] = { {"createArray", createArray, 1}, {NULL, NULL} /* Sentinel */ }; static char bug_documentation[] = "No Doc"; #ifdef WIN32 extern __declspec(dllexport) #endif void initbug() { PyObject *m, *d; m = Py_InitModule4("bug", bug_methods, bug_documentation, (PyObject *)NULL, PYTHON_API_VERSION); d = PyModule_GetDict(m); import_array(); if (PyErr_Occurred()) Py_FatalError("can't initialize module bug"); } ##################################################################### ###############testbug.py############################################ import bug ar = bug.createArray() del ar # fatal if ar owns the data member ##################################################################### -- ********************************** Alexandre Gillet The Scripps Research Institute, tel: (858) 784-9557 Dept. Molecular Biology, MB-5, fax: (858) 784-2860 10550 North Torrey Pines Road, email: gillet@scripps.edu La Jolla, CA 92037-1000, USA.