cpython/Modules/atexitmodule.c
2008-09-23 00:52:29 +00:00

269 lines
6.5 KiB
C

/*
* atexit - allow programmer to define multiple exit functions to be executed
* upon normal program termination.
*
* Translated from atexit.py by Collin Winter.
+ Copyright 2007 Python Software Foundation.
*/
#include "Python.h"
/* Forward declaration (for atexit_cleanup) */
static PyObject *atexit_clear(PyObject*);
/* Forward declaration (for atexit_callfuncs) */
static void atexit_cleanup(void);
/* ===================================================================== */
/* Callback machinery. */
typedef struct {
PyObject *func;
PyObject *args;
PyObject *kwargs;
} atexit_callback;
static atexit_callback **atexit_callbacks;
static int ncallbacks = 0;
static int callback_len = 32;
/* Installed into pythonrun.c's atexit mechanism */
static void
atexit_callfuncs(void)
{
PyObject *exc_type = NULL, *exc_value, *exc_tb, *r;
atexit_callback *cb;
int i;
if (ncallbacks == 0)
return;
for (i = ncallbacks - 1; i >= 0; i--)
{
cb = atexit_callbacks[i];
if (cb == NULL)
continue;
r = PyObject_Call(cb->func, cb->args, cb->kwargs);
Py_XDECREF(r);
if (r == NULL) {
/* Maintain the last exception, but don't leak if there are
multiple exceptions. */
if (exc_type) {
Py_DECREF(exc_type);
Py_XDECREF(exc_value);
Py_XDECREF(exc_tb);
}
PyErr_Fetch(&exc_type, &exc_value, &exc_tb);
if (!PyErr_ExceptionMatches(PyExc_SystemExit)) {
PySys_WriteStderr("Error in atexit._run_exitfuncs:\n");
PyErr_Display(exc_type, exc_value, exc_tb);
}
}
}
atexit_cleanup();
if (exc_type)
PyErr_Restore(exc_type, exc_value, exc_tb);
}
static void
atexit_delete_cb(int i)
{
atexit_callback *cb = atexit_callbacks[i];
atexit_callbacks[i] = NULL;
Py_DECREF(cb->func);
Py_DECREF(cb->args);
Py_XDECREF(cb->kwargs);
PyMem_Free(cb);
}
static void
atexit_cleanup(void)
{
PyObject *r = atexit_clear(NULL);
Py_DECREF(r);
}
/* ===================================================================== */
/* Module methods. */
PyDoc_STRVAR(atexit_register__doc__,
"register(func, *args, **kwargs) -> func\n\
\n\
Register a function to be executed upon normal program termination\n\
\n\
func - function to be called at exit\n\
args - optional arguments to pass to func\n\
kwargs - optional keyword arguments to pass to func\n\
\n\
func is returned to facilitate usage as a decorator.");
static PyObject *
atexit_register(PyObject *self, PyObject *args, PyObject *kwargs)
{
atexit_callback *new_callback;
PyObject *func = NULL;
if (ncallbacks >= callback_len) {
atexit_callback **r;
callback_len += 16;
r = (atexit_callback**)PyMem_Realloc(atexit_callbacks,
sizeof(atexit_callback*) * callback_len);
if (r == NULL)
return PyErr_NoMemory();
atexit_callbacks = r;
}
if (PyTuple_GET_SIZE(args) == 0) {
PyErr_SetString(PyExc_TypeError,
"register() takes at least 1 argument (0 given)");
return NULL;
}
func = PyTuple_GET_ITEM(args, 0);
if (!PyCallable_Check(func)) {
PyErr_SetString(PyExc_TypeError,
"the first argument must be callable");
return NULL;
}
new_callback = PyMem_Malloc(sizeof(atexit_callback));
if (new_callback == NULL)
return PyErr_NoMemory();
new_callback->args = PyTuple_GetSlice(args, 1, PyTuple_GET_SIZE(args));
if (new_callback->args == NULL) {
PyMem_Free(new_callback);
return NULL;
}
new_callback->func = func;
new_callback->kwargs = kwargs;
Py_INCREF(func);
Py_XINCREF(kwargs);
atexit_callbacks[ncallbacks++] = new_callback;
Py_INCREF(func);
return func;
}
PyDoc_STRVAR(atexit_run_exitfuncs__doc__,
"_run_exitfuncs() -> None\n\
\n\
Run all registered exit functions.");
static PyObject *
atexit_run_exitfuncs(PyObject *self)
{
atexit_callfuncs();
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
PyDoc_STRVAR(atexit_clear__doc__,
"_clear() -> None\n\
\n\
Clear the list of previously registered exit functions.");
static PyObject *
atexit_clear(PyObject *self)
{
atexit_callback *cb;
int i;
for (i = 0; i < ncallbacks; i++)
{
cb = atexit_callbacks[i];
if (cb == NULL)
continue;
atexit_delete_cb(i);
}
ncallbacks = 0;
Py_RETURN_NONE;
}
PyDoc_STRVAR(atexit_unregister__doc__,
"unregister(func) -> None\n\
\n\
Unregister a exit function which was previously registered using\n\
atexit.register\n\
\n\
func - function to be unregistered");
static PyObject *
atexit_unregister(PyObject *self, PyObject *func)
{
atexit_callback *cb;
int i, eq;
for (i = 0; i < ncallbacks; i++)
{
cb = atexit_callbacks[i];
if (cb == NULL)
continue;
eq = PyObject_RichCompareBool(cb->func, func, Py_EQ);
if (eq < 0)
return NULL;
if (eq)
atexit_delete_cb(i);
}
Py_RETURN_NONE;
}
static PyMethodDef atexit_methods[] = {
{"register", (PyCFunction) atexit_register, METH_VARARGS|METH_KEYWORDS,
atexit_register__doc__},
{"_clear", (PyCFunction) atexit_clear, METH_NOARGS,
atexit_clear__doc__},
{"unregister", (PyCFunction) atexit_unregister, METH_O,
atexit_unregister__doc__},
{"_run_exitfuncs", (PyCFunction) atexit_run_exitfuncs, METH_NOARGS,
atexit_run_exitfuncs__doc__},
{NULL, NULL} /* sentinel */
};
/* ===================================================================== */
/* Initialization function. */
PyDoc_STRVAR(atexit__doc__,
"allow programmer to define multiple exit functions to be executed\
upon normal program termination.\n\
\n\
Two public functions, register and unregister, are defined.\n\
");
static struct PyModuleDef atexitmodule = {
PyModuleDef_HEAD_INIT,
"atexit",
atexit__doc__,
-1,
atexit_methods,
NULL,
NULL,
NULL,
NULL
};
PyMODINIT_FUNC
PyInit_atexit(void)
{
PyObject *m;
atexit_callbacks = PyMem_New(atexit_callback*, callback_len);
if (atexit_callbacks == NULL)
return NULL;
m = PyModule_Create(&atexitmodule);
if (m == NULL)
return NULL;
_Py_PyAtExit(atexit_callfuncs);
return m;
}