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gh-94401: Remove unneeded overlapped module state #94403

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Merged
merged 2 commits into from
Jun 29, 2022
Merged

gh-94401: Remove unneeded overlapped module state #94403

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79de37b
Remove unneeded overlapped module state
erlend-aasland Jun 28, 2022
333a541
Update Modules/overlapped.c
Jun 29, 2022
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49 changes: 6 additions & 43 deletions Modules/overlapped.c
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Original file line number Diff line number Diff line change
Expand Up @@ -105,18 +105,6 @@ typedef struct {
};
} OverlappedObject;

typedef struct {
PyTypeObject *overlapped_type;
} OverlappedState;

static inline OverlappedState*
overlapped_get_state(PyObject *module)
{
void *state = PyModule_GetState(module);
assert(state != NULL);
return (OverlappedState *)state;
}


static inline void
steal_buffer(Py_buffer * dst, Py_buffer * src)
Expand Down Expand Up @@ -1996,28 +1984,6 @@ static PyMethodDef overlapped_functions[] = {
{NULL}
};

static int
overlapped_traverse(PyObject *module, visitproc visit, void *arg)
{
OverlappedState *state = overlapped_get_state(module);
Py_VISIT(state->overlapped_type);
return 0;
}

static int
overlapped_clear(PyObject *module)
{
OverlappedState *state = overlapped_get_state(module);
Py_CLEAR(state->overlapped_type);
return 0;
}

static void
overlapped_free(void *module)
{
overlapped_clear((PyObject *)module);
}

#define WINAPI_CONSTANT(fmt, con) \
do { \
PyObject *value = Py_BuildValue(fmt, con); \
Expand Down Expand Up @@ -2045,14 +2011,15 @@ overlapped_exec(PyObject *module)
return -1;
}

OverlappedState *st = overlapped_get_state(module);
st->overlapped_type = (PyTypeObject *)PyType_FromModuleAndSpec(
PyTypeObject *overlapped_type = (PyTypeObject *)PyType_FromModuleAndSpec(
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Is PyType_FromModuleAndSpec the correct API to retrieve a type object from a module by spec? It calls PyType_FromMetaclass, which does a lot of extra work.

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All the PyType_From* APIs call PyType_FromMetaclass. The recent changes to the PyType_From* APIs should not result in a lot of extra work. If that is the case, PyType_FromMetaclass should be optimised, if possible.

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I was under the assumption that the PyType_From* APIs are used to create a new type object from a spec, not fetch an existing type. It may even leak memory . PyType_FromMetaclass calls PyMem_Malloc and eventually assigns it to type->tp_name eventually without a check.

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Each call allocates a whole new type on the heap memory.

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IMO, if there are issues with PEP-489 and the PyType_From* APIs they should be addressed in a separate issue and discussed there. Suggesting to mark this conversation as resolved and continue this discussion in an appropriate issue if needed.

module, &overlapped_type_spec, NULL);
if (st->overlapped_type == NULL) {
if (overlapped_type == NULL) {
return -1;
}

if (PyModule_AddType(module, st->overlapped_type) < 0) {
int rc = PyModule_AddType(module, overlapped_type);
Py_DECREF(overlapped_type);
if (rc < 0) {
return -1;
}

Expand All @@ -2077,14 +2044,10 @@ static PyModuleDef_Slot overlapped_slots[] = {
};

static struct PyModuleDef overlapped_module = {
PyModuleDef_HEAD_INIT,
.m_base = PyModuleDef_HEAD_INIT,
.m_name = "_overlapped",
.m_size = sizeof(OverlappedState),
.m_methods = overlapped_functions,
.m_slots = overlapped_slots,
.m_traverse = overlapped_traverse,
.m_clear = overlapped_clear,
.m_free = overlapped_free
};

PyMODINIT_FUNC
Expand Down