bpo-42639: Cleanup atexitmodule.c (GH-23770)

* Rename "atexitmodule_state" to "struct atexit_state".
* Rename "modstate" to "state".
* Rename "self" parameter to "module".
* test_atexit uses textwrap.dedent().
* Remove _Py_PyAtExit() function: inline it into atexit_exec().
* PyInterpreterState: rename pyexitfunc to atexit_func, rename
  pyexitmodule to atexit_module.
This commit is contained in:
Victor Stinner 2020-12-14 22:40:40 +01:00 committed by GitHub
parent fdb9efce6a
commit 83d52044ae
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 126 additions and 159 deletions

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@ -35,11 +35,6 @@ PyAPI_FUNC(int) Py_RunMain(void);
PyAPI_FUNC(void) _Py_NO_RETURN Py_ExitStatusException(PyStatus err);
/* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
* exit functions.
*/
PyAPI_FUNC(void) _Py_PyAtExit(void (*func)(PyObject *), PyObject *);
/* Restore signals that the interpreter has called SIG_IGN on to SIG_DFL. */
PyAPI_FUNC(void) _Py_RestoreSignals(void);

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@ -234,8 +234,8 @@ struct _is {
PyObject *after_forkers_child;
#endif
/* AtExit module */
void (*pyexitfunc)(PyObject *);
PyObject *pyexitmodule;
void (*atexit_func)(PyObject *);
PyObject *atexit_module;
uint64_t tstate_next_unique_id;

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@ -1,8 +1,9 @@
import sys
import unittest
import io
import atexit
import io
import os
import sys
import textwrap
import unittest
from test import support
from test.support import script_helper
@ -156,7 +157,7 @@ class GeneralTest(unittest.TestCase):
def test_shutdown(self):
# Actually test the shutdown mechanism in a subprocess
code = """if 1:
code = textwrap.dedent("""
import atexit
def f(msg):
@ -164,7 +165,7 @@ class GeneralTest(unittest.TestCase):
atexit.register(f, "one")
atexit.register(f, "two")
"""
""")
res = script_helper.assert_python_ok("-c", code)
self.assertEqual(res.out.decode().splitlines(), ["two", "one"])
self.assertFalse(res.err)
@ -178,13 +179,13 @@ class SubinterpreterTest(unittest.TestCase):
# take care to free callbacks in its per-subinterpreter module
# state.
n = atexit._ncallbacks()
code = r"""if 1:
code = textwrap.dedent(r"""
import atexit
def f():
pass
atexit.register(f)
del atexit
"""
""")
ret = support.run_in_subinterp(code)
self.assertEqual(ret, 0)
self.assertEqual(atexit._ncallbacks(), n)
@ -193,13 +194,13 @@ class SubinterpreterTest(unittest.TestCase):
# Similar to the above, but with a refcycle through the atexit
# module.
n = atexit._ncallbacks()
code = r"""if 1:
code = textwrap.dedent(r"""
import atexit
def f():
pass
atexit.register(f)
atexit.__atexit = atexit
"""
""")
ret = support.run_in_subinterp(code)
self.assertEqual(ret, 0)
self.assertEqual(atexit._ncallbacks(), n)
@ -210,13 +211,13 @@ class SubinterpreterTest(unittest.TestCase):
expected = b"The test has passed!"
r, w = os.pipe()
code = r"""if 1:
code = textwrap.dedent(r"""
import os
import atexit
def callback():
os.write({:d}, b"The test has passed!")
atexit.register(callback)
""".format(w)
""".format(w))
ret = support.run_in_subinterp(code)
os.close(w)
self.assertEqual(os.read(r, len(expected)), expected)

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@ -7,11 +7,8 @@
*/
#include "Python.h"
/* Forward declaration (for atexit_cleanup) */
static PyObject *atexit_clear(PyObject*, PyObject*);
/* Forward declaration of module object */
static struct PyModuleDef atexitmodule;
#include "pycore_interp.h" // PyInterpreterState.atexit_func
#include "pycore_pystate.h" // _PyInterpreterState_GET
/* ===================================================================== */
/* Callback machinery. */
@ -22,48 +19,47 @@ typedef struct {
PyObject *kwargs;
} atexit_callback;
typedef struct {
struct atexit_state {
atexit_callback **atexit_callbacks;
int ncallbacks;
int callback_len;
} atexitmodule_state;
};
static inline atexitmodule_state*
static inline struct atexit_state*
get_atexit_state(PyObject *module)
{
void *state = PyModule_GetState(module);
assert(state != NULL);
return (atexitmodule_state *)state;
return (struct atexit_state *)state;
}
static void
atexit_delete_cb(atexitmodule_state *modstate, int i)
atexit_delete_cb(struct atexit_state *state, int i)
{
atexit_callback *cb;
atexit_callback *cb = state->atexit_callbacks[i];
state->atexit_callbacks[i] = NULL;
cb = modstate->atexit_callbacks[i];
modstate->atexit_callbacks[i] = NULL;
Py_DECREF(cb->func);
Py_DECREF(cb->args);
Py_XDECREF(cb->kwargs);
PyMem_Free(cb);
}
/* Clear all callbacks without calling them */
static void
atexit_cleanup(atexitmodule_state *modstate)
atexit_cleanup(struct atexit_state *state)
{
atexit_callback *cb;
int i;
for (i = 0; i < modstate->ncallbacks; i++) {
cb = modstate->atexit_callbacks[i];
for (int i = 0; i < state->ncallbacks; i++) {
cb = state->atexit_callbacks[i];
if (cb == NULL)
continue;
atexit_delete_cb(modstate, i);
atexit_delete_cb(state, i);
}
modstate->ncallbacks = 0;
state->ncallbacks = 0;
}
/* Installed into pylifecycle.c's atexit mechanism */
@ -71,28 +67,26 @@ atexit_cleanup(atexitmodule_state *modstate)
static void
atexit_callfuncs(PyObject *module)
{
PyObject *exc_type = NULL, *exc_value, *exc_tb, *r;
atexit_callback *cb;
atexitmodule_state *modstate;
int i;
assert(!PyErr_Occurred());
if (module == NULL)
if (module == NULL) {
return;
modstate = get_atexit_state(module);
}
if (modstate->ncallbacks == 0)
struct atexit_state *state = get_atexit_state(module);
if (state->ncallbacks == 0) {
return;
}
for (i = modstate->ncallbacks - 1; i >= 0; i--)
{
cb = modstate->atexit_callbacks[i];
if (cb == NULL)
PyObject *exc_type = NULL, *exc_value, *exc_tb;
for (int i = state->ncallbacks - 1; i >= 0; i--) {
atexit_callback *cb = state->atexit_callbacks[i];
if (cb == NULL) {
continue;
}
r = PyObject_Call(cb->func, cb->args, cb->kwargs);
Py_XDECREF(r);
if (r == NULL) {
PyObject *res = PyObject_Call(cb->func, cb->args, cb->kwargs);
if (res == NULL) {
/* Maintain the last exception, but don't leak if there are
multiple exceptions. */
if (exc_type) {
@ -107,13 +101,17 @@ atexit_callfuncs(PyObject *module)
PyErr_Display(exc_type, exc_value, exc_tb);
}
}
else {
Py_DECREF(res);
}
}
atexit_cleanup(modstate);
atexit_cleanup(state);
if (exc_type)
if (exc_type) {
PyErr_Restore(exc_type, exc_value, exc_tb);
}
}
/* ===================================================================== */
/* Module methods. */
@ -130,55 +128,48 @@ Register a function to be executed upon normal program termination\n\
func is returned to facilitate usage as a decorator.");
static PyObject *
atexit_register(PyObject *self, PyObject *args, PyObject *kwargs)
atexit_register(PyObject *module, PyObject *args, PyObject *kwargs)
{
atexitmodule_state *modstate;
atexit_callback *new_callback;
PyObject *func = NULL;
modstate = get_atexit_state(self);
if (modstate->ncallbacks >= modstate->callback_len) {
atexit_callback **r;
modstate->callback_len += 16;
r = (atexit_callback**)PyMem_Realloc(modstate->atexit_callbacks,
sizeof(atexit_callback*) * modstate->callback_len);
if (r == NULL)
return PyErr_NoMemory();
modstate->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);
PyObject *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)
struct atexit_state *state = get_atexit_state(module);
if (state->ncallbacks >= state->callback_len) {
atexit_callback **r;
state->callback_len += 16;
r = (atexit_callback**)PyMem_Realloc(state->atexit_callbacks,
sizeof(atexit_callback*) * state->callback_len);
if (r == NULL)
return PyErr_NoMemory();
state->atexit_callbacks = r;
}
new_callback->args = PyTuple_GetSlice(args, 1, PyTuple_GET_SIZE(args));
if (new_callback->args == NULL) {
PyMem_Free(new_callback);
atexit_callback *callback = PyMem_Malloc(sizeof(atexit_callback));
if (callback == NULL) {
return PyErr_NoMemory();
}
callback->args = PyTuple_GetSlice(args, 1, PyTuple_GET_SIZE(args));
if (callback->args == NULL) {
PyMem_Free(callback);
return NULL;
}
new_callback->func = func;
new_callback->kwargs = kwargs;
Py_INCREF(func);
Py_XINCREF(kwargs);
callback->func = Py_NewRef(func);
callback->kwargs = Py_XNewRef(kwargs);
modstate->atexit_callbacks[modstate->ncallbacks++] = new_callback;
state->atexit_callbacks[state->ncallbacks++] = callback;
Py_INCREF(func);
return func;
return Py_NewRef(func);
}
PyDoc_STRVAR(atexit_run_exitfuncs__doc__,
@ -187,11 +178,12 @@ PyDoc_STRVAR(atexit_run_exitfuncs__doc__,
Run all registered exit functions.");
static PyObject *
atexit_run_exitfuncs(PyObject *self, PyObject *unused)
atexit_run_exitfuncs(PyObject *module, PyObject *unused)
{
atexit_callfuncs(self);
if (PyErr_Occurred())
atexit_callfuncs(module);
if (PyErr_Occurred()) {
return NULL;
}
Py_RETURN_NONE;
}
@ -201,9 +193,9 @@ PyDoc_STRVAR(atexit_clear__doc__,
Clear the list of previously registered exit functions.");
static PyObject *
atexit_clear(PyObject *self, PyObject *unused)
atexit_clear(PyObject *module, PyObject *unused)
{
atexit_cleanup(get_atexit_state(self));
atexit_cleanup(get_atexit_state(module));
Py_RETURN_NONE;
}
@ -213,25 +205,18 @@ PyDoc_STRVAR(atexit_ncallbacks__doc__,
Return the number of registered exit functions.");
static PyObject *
atexit_ncallbacks(PyObject *self, PyObject *unused)
atexit_ncallbacks(PyObject *module, PyObject *unused)
{
atexitmodule_state *modstate;
modstate = get_atexit_state(self);
return PyLong_FromSsize_t(modstate->ncallbacks);
struct atexit_state *state = get_atexit_state(module);
return PyLong_FromSsize_t(state->ncallbacks);
}
static int
atexit_m_traverse(PyObject *self, visitproc visit, void *arg)
atexit_m_traverse(PyObject *module, visitproc visit, void *arg)
{
int i;
atexitmodule_state *modstate;
modstate = (atexitmodule_state *)PyModule_GetState(self);
for (i = 0; i < modstate->ncallbacks; i++) {
atexit_callback *cb = modstate->atexit_callbacks[i];
struct atexit_state *state = (struct atexit_state *)PyModule_GetState(module);
for (int i = 0; i < state->ncallbacks; i++) {
atexit_callback *cb = state->atexit_callbacks[i];
if (cb == NULL)
continue;
Py_VISIT(cb->func);
@ -242,21 +227,19 @@ atexit_m_traverse(PyObject *self, visitproc visit, void *arg)
}
static int
atexit_m_clear(PyObject *self)
atexit_m_clear(PyObject *module)
{
atexitmodule_state *modstate;
modstate = (atexitmodule_state *)PyModule_GetState(self);
atexit_cleanup(modstate);
struct atexit_state *state = (struct atexit_state *)PyModule_GetState(module);
atexit_cleanup(state);
return 0;
}
static void
atexit_free(PyObject *m)
atexit_free(PyObject *module)
{
atexitmodule_state *modstate;
modstate = (atexitmodule_state *)PyModule_GetState(m);
atexit_cleanup(modstate);
PyMem_Free(modstate->atexit_callbacks);
struct atexit_state *state = (struct atexit_state *)PyModule_GetState(module);
atexit_cleanup(state);
PyMem_Free(state->atexit_callbacks);
}
PyDoc_STRVAR(atexit_unregister__doc__,
@ -268,29 +251,28 @@ atexit.register\n\
func - function to be unregistered");
static PyObject *
atexit_unregister(PyObject *self, PyObject *func)
atexit_unregister(PyObject *module, PyObject *func)
{
atexitmodule_state *modstate;
atexit_callback *cb;
int i, eq;
modstate = get_atexit_state(self);
for (i = 0; i < modstate->ncallbacks; i++)
struct atexit_state *state = get_atexit_state(module);
for (int i = 0; i < state->ncallbacks; i++)
{
cb = modstate->atexit_callbacks[i];
if (cb == NULL)
atexit_callback *cb = state->atexit_callbacks[i];
if (cb == NULL) {
continue;
}
eq = PyObject_RichCompareBool(cb->func, func, Py_EQ);
if (eq < 0)
int eq = PyObject_RichCompareBool(cb->func, func, Py_EQ);
if (eq < 0) {
return NULL;
if (eq)
atexit_delete_cb(modstate, i);
}
if (eq) {
atexit_delete_cb(state, i);
}
}
Py_RETURN_NONE;
}
static PyMethodDef atexit_methods[] = {
{"register", (PyCFunction)(void(*)(void)) atexit_register, METH_VARARGS|METH_KEYWORDS,
atexit_register__doc__},
@ -316,18 +298,19 @@ Two public functions, register and unregister, are defined.\n\
");
static int
atexit_exec(PyObject *m) {
atexitmodule_state *modstate;
modstate = get_atexit_state(m);
modstate->callback_len = 32;
modstate->ncallbacks = 0;
modstate->atexit_callbacks = PyMem_New(atexit_callback*,
modstate->callback_len);
if (modstate->atexit_callbacks == NULL)
atexit_exec(PyObject *module)
{
struct atexit_state *state = get_atexit_state(module);
state->callback_len = 32;
state->ncallbacks = 0;
state->atexit_callbacks = PyMem_New(atexit_callback*, state->callback_len);
if (state->atexit_callbacks == NULL) {
return -1;
}
_Py_PyAtExit(atexit_callfuncs, m);
PyInterpreterState *is = _PyInterpreterState_GET();
is->atexit_func = atexit_callfuncs;
is->atexit_module = module;
return 0;
}
@ -338,14 +321,14 @@ static PyModuleDef_Slot atexit_slots[] = {
static struct PyModuleDef atexitmodule = {
PyModuleDef_HEAD_INIT,
"atexit",
atexit__doc__,
sizeof(atexitmodule_state),
atexit_methods,
atexit_slots,
atexit_m_traverse,
atexit_m_clear,
(freefunc)atexit_free
.m_name = "atexit",
.m_doc = atexit__doc__,
.m_size = sizeof(struct atexit_state),
.m_methods = atexit_methods,
.m_slots = atexit_slots,
.m_traverse = atexit_m_traverse,
.m_clear = atexit_m_clear,
.m_free = (freefunc)atexit_free
};
PyMODINIT_FUNC

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@ -2634,26 +2634,14 @@ Py_ExitStatusException(PyStatus status)
/* Clean up and exit */
/* For the atexit module. */
void _Py_PyAtExit(void (*func)(PyObject *), PyObject *module)
{
PyInterpreterState *is = _PyInterpreterState_GET();
/* Guard against API misuse (see bpo-17852) */
assert(is->pyexitfunc == NULL || is->pyexitfunc == func);
is->pyexitfunc = func;
is->pyexitmodule = module;
}
static void
call_py_exitfuncs(PyThreadState *tstate)
{
PyInterpreterState *interp = tstate->interp;
if (interp->pyexitfunc == NULL)
if (interp->atexit_func == NULL)
return;
(*interp->pyexitfunc)(interp->pyexitmodule);
interp->atexit_func(interp->atexit_module);
_PyErr_Clear(tstate);
}