Patch #1680961: remove sys.exitfunc and replace it with a private C API. Also, reimplement atexit in C so it can take advantage of this private API.

1 files changed, 217 insertions, 0 deletions

diff --git a/Modules/atexitmodule.c b/Modules/atexitmodule.c
new file mode 100644
index 0000000..b8a8bf6
--- /dev/null
+++ b/Modules/atexitmodule.c
@@ -0,0 +1,217 @@
+/*
+ *  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"
+
+/* ===================================================================== */
+/* Callback machinery. */
+
+typedef struct {
+    PyObject *func;
+    PyObject *args;
+    PyObject *kwargs;
+} atexit_callback;
+
+atexit_callback **atexit_callbacks;
+int ncallbacks = 0;
+int callback_len = 32;
+
+/* Installed into pythonrun.c's atexit mechanism */
+
+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) {
+            if (exc_type) {
+                Py_DECREF(exc_type);
+                Py_DECREF(exc_value);
+                Py_DECREF(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);
+            }
+        }
+    }
+    
+    if (exc_type)
+        PyErr_Restore(exc_type, exc_value, exc_tb);
+}
+
+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);    
+}
+
+/* ===================================================================== */
+/* 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) {
+        callback_len += 16;
+        atexit_callbacks = PyMem_Realloc(atexit_callbacks,
+                          sizeof(atexit_callback*) * callback_len);
+
+    }
+    
+    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;
+}
+
+static PyObject *
+atexit_run_exitfuncs(PyObject *self)
+{
+    atexit_callfuncs();
+    if (PyErr_Occurred())
+        return NULL;
+    Py_RETURN_NONE;
+}
+
+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;
+}
+
+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,
+        NULL},
+    {"unregister", (PyCFunction) atexit_unregister, METH_O,
+        NULL},
+    {"_run_exitfuncs", (PyCFunction) atexit_run_exitfuncs, METH_NOARGS,
+        NULL},
+    {NULL, NULL}        /* sentinel */
+};
+
+/* ===================================================================== */
+/* Initialization function. */
+
+PyDoc_STRVAR(atexit__doc__,
+"atexit.py - allow programmer to define multiple exit functions to be executed\
+upon normal program termination.\n\
+\n\
+One public function, register, is defined.\n\
+");
+
+PyMODINIT_FUNC
+initatexit(void)
+{
+    PyObject *m;
+    
+    atexit_callbacks = PyMem_New(atexit_callback*, callback_len);
+    if (atexit_callbacks == NULL)
+        return;
+
+    m = Py_InitModule3("atexit", atexit_methods, atexit__doc__);
+    if (m == NULL)
+        return;
+    
+    _Py_PyAtExit(atexit_callfuncs);
+}