Blog Main Page Template

import os import subprocess import sys import sysconfig import tempfile CSRC = r""" #include <Python.h>  static Py_ssize_t list_destroys = 0;  static int tracer(PyObject *obj, PyRefTracerEvent event, void *data) {  if (event == PyRefTracer_DESTROY && PyList_CheckExact(obj)) {  list_destroys++;  }  return 0; }  static PyObject * start(PyObject *self, PyObject *args) {  list_destroys = 0;  if (PyRefTracer_SetTracer(tracer, NULL) < 0) {  return NULL;  }  Py_RETURN_NONE; }  static PyObject * stop(PyObject *self, PyObject *args) {  if (PyRefTracer_SetTracer(NULL, NULL) < 0) {  return NULL;  }  return PyLong_FromSsize_t(list_destroys); }  static PyMethodDef methods[] = {  {"start", start, METH_NOARGS, NULL},  {"stop", stop, METH_NOARGS, NULL},  {NULL, NULL, 0, NULL}, };  static PyModuleDef_Slot slots[] = { #ifdef Py_GIL_DISABLED  {Py_mod_gil, Py_MOD_GIL_NOT_USED}, #endif  {0, NULL}, };  static struct PyModuleDef module = {  PyModuleDef_HEAD_INIT,  .m_name = "reftrace_repro",  .m_size = 0,  .m_methods = methods,  .m_slots = slots, };  PyMODINIT_FUNC PyInit_reftrace_repro(void) {  return PyModuleDef_Init(&module); } """ def build_module(): tmpdir = tempfile.mkdtemp(prefix="reftrace_repro_") src = os.path.join(tmpdir, "reftrace_repro.c") with open(src, "w") as f: f.write(CSRC) ext = os.path.join(tmpdir, "reftrace_repro.so") cmd = ["cc", "-O2", "-shared", "-fPIC", "-I", sysconfig.get_path("include"), "-I", sysconfig.get_path("platinclude"), "-o", ext, src] if sys.platform == "darwin": cmd.insert(3, "-undefined") cmd.insert(4, "dynamic_lookup") subprocess.run(cmd, check=True) sys.path.insert(0, tmpdir) def run(depth): import reftrace_repro chain = None for _ in range(depth): chain = [chain] reftrace_repro.start() del chain destroys = reftrace_repro.stop() missing = depth - destroys print(f"depth={depth:>7} DESTROY events={destroys:>7} " f"missing={missing:>5} [{'BUG' if missing else 'OK'}]") if __name__ == "__main__": print(sys.version) build_module() run(100) run(200_000)