[issue1635741] Py_Finalize() doesn't clear all Python objects at exit

[STINNER Victor]

STINNER Victor <vstinner at python.org> added the comment:

I tested on the master branch of Python:
---
#include <Python.h>

void func()
{
    Py_Initialize(); Py_Finalize();
    Py_ssize_t cnt = _Py_GetRefTotal();
    printf("sys.gettotalrefcount(): %zd\n", cnt);
}

int main(int argc, char *argv[])
{
    Py_SetProgramName(L"./_testembed");
    for (int i=0; i < 10; i++) {
        func();
    }
}
---

Each iteration leaks around 5,000 Python objects:
---
sys.gettotalrefcount(): 15113
sys.gettotalrefcount(): 19527
sys.gettotalrefcount(): 23941
sys.gettotalrefcount(): 28355
sys.gettotalrefcount(): 32769
sys.gettotalrefcount(): 37183
sys.gettotalrefcount(): 41597
sys.gettotalrefcount(): 46011
sys.gettotalrefcount(): 50425
sys.gettotalrefcount(): 54839
---

----------
nosy: +vstinner
title: Interpreter seems to leak references after finalization -> Py_Finalize() doesn't clear all Python objects at exit
versions: +Python 3.9 -Python 2.7, Python 3.1, Python 3.2

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue1635741>
_______________________________________