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Forcing enabling the GIL doesn't seem to work with PEP 793 initialization #141780
Description
Bug report
Bug description:
#include <Python.h>
static int
examplemodule_exec(PyObject *module) {
// Yes I know there's no error checking...
PyObject *gil_enabled = PySys_GetObject("_is_gil_enabled");
PyObject *result = PyObject_CallNoArgs(gil_enabled);
printf("gil enabled: ");
PyObject_Print(result, stdout, 0);
printf("\n");
Py_DECREF(result);
return 0;
}
static PyModuleDef_Slot examplemodule_slots[] = {
{Py_mod_name, "examplemodule"},
{Py_mod_gil, Py_MOD_GIL_USED},
{Py_mod_exec, (void*)examplemodule_exec},
{0}
};
PyMODEXPORT_FUNC
PyModExport_examplemodule(void)
{
return examplemodule_slots;
}I believe that the code above should print "gil enabled: True". However when I run it on Python 3.15.0a2 freethreading it prints "gil enabled: False".
I don't believe this is an issue in the old style PyInit_ initialization.
CPython versions tested on:
3.15
Operating systems tested on:
Linux
Activity
[-]Disabling the GIL doesn't seem to work with PEP 793 initialization[/-][+]Forcing enabling the GIL doesn't seem to work with PEP 793 initialization[/+]da-woods commentedon Nov 20, 2025
@encukou
pythongh-141780: Make PyModule_FromSlotsAndSpec enable GIL if needed
encukou commentedon Nov 20, 2025
Thanks for the catch!
gh-141780: Make PyModule_FromSlotsAndSpec enable GIL if needed (GH-1…
da-woods commentedon Nov 24, 2025
Thanks
pythongh-141780: Make PyModule_FromSlotsAndSpec enable GIL if needed (…
pythongh-141780: Make PyModule_FromSlotsAndSpec enable GIL if needed (…