python & c-c++扩展模块案例段错误

Question

C++代码

extern "C" PyObject * test(){
    PyObject *oplist = PyList_New(10000);
    for(uint32_t j = 0; j < 10000; j++){
        PyObject* pTuple = PyTuple_New(3);
        assert(PyTuple_Check(pTuple));
        assert(PyTuple_Size(pTuple) == 3);
        PyTuple_SetItem(pTuple, 0, Py_BuildValue("s", "b"));
        PyTuple_SetItem(pTuple, 1, Py_BuildValue("i", 1)); 
        PyTuple_SetItem(pTuple, 2, Py_BuildValue("s", "a"));
        PyList_SetItem(oplist, j, pTuple);
    }    
    return oplist;
}

Python代码

LID = ctypes.CDLL('%s/token2map_lib.so' % '.')
LID.test.restype = py_object
LID.test()

构建cmd
g++ -fPIC token2map.cpp -I/usr/local/app/service/virtualenvs/NLP/include/python2.7 -shared -o token2map_lib.so
我只展示了部分代码，请原谅我，总代码太长

问题:在c++代码中，这个函数返回的res_list很小，一切正常。永远，结果集超过 215(j = 215) 个情况段falut。我找不到问题，希望现在的 friend 能给我一些建议，我将非常感激。

我有办法解决这个问题

extern "C" PyObject * test(){
    PyGILState_STATE gstate = PyGILState_Ensure();
    PyObject *oplist = PyTuple_New(10000);
    for(int32_t j = 0; j < 10000; j++){
        PyObject * pTuple = PyTuple_New(3);
        assert(PyTuple_Check(pTuple));
        assert(PyTuple_Size(pTuple) == 3);
        PyTuple_SetItem(pTuple, 0, Py_BuildValue("s", "b"));
        PyTuple_SetItem(pTuple, 1, Py_BuildValue("i", 1)); 
        PyTuple_SetItem(pTuple, 2, Py_BuildValue("s", "a"));
        PyTuple_SetItem(oplist, j, pTuple);
    }    
    PyGILState_Release(gstate);
    return oplist;
}

但是有其他方法可以解决这个问题吗？我不认为获得 GIL locak 是一个好方法

Answer 1

我无法向您解释为什么您的代码会出现段错误。我确实发现有趣的是，您能够使用不带参数的函数构建扩展。不过，我可以提供可以构建和工作的代码:

#define Py_SSIZE_T_CLEAN
#include <Python.h>
#include <inttypes.h>
#ifdef __cplusplus
extern "C" {
#endif

static PyObject *test(PyObject *self, PyObject *ignorethis)
{
    PyObject *oplist = PyList_New(10000);
    for(uint32_t j = 0; j < 10000; ++j){
        PyObject *pTuple = PyTuple_New(3);
        PyTuple_SetItem(pTuple, 0, Py_BuildValue("s", "b"));
        PyTuple_SetItem(pTuple, 1, Py_BuildValue("i", 1));
        PyTuple_SetItem(pTuple, 2, Py_BuildValue("s", "a"));
        PyList_SetItem(oplist, j, pTuple);
    }
    return oplist;
}

static PyMethodDef methods[] = {
    {"test", test, METH_NOARGS, "function given by so"}
};

static PyModuleDef foobar = {
    PyModuleDef_HEAD_INIT,
    "foobar",
    "so question module",
    -1,
    methods
};

PyMODINIT_FUNC PyInit_foobar(void){
    PyObject *module;
    module = PyModule_Create(&foobar);
    return module;
}

#ifdef __cplusplus
}
#endif

您可以使用import foobar加载此模块，然后使用foobar.test()运行