@@ -215,21 +215,36 @@ multiple interpreters correctly. If this is not yet the case for your
215215module, you can explicitly make your module loadable only once per
216216process. For example::
217217
218+ // A process-wide flag
218219 static int loaded = 0;
219220
221+ // Mutex to provide thread safety (only needed for free-threaded Python)
222+ static PyMutex modinit_mutex = {0};
223+
220224 static int
221225 exec_module(PyObject* module)
222226 {
227+ PyMutex_Lock(&modinit_mutex);
223228 if (loaded) {
229+ PyMutex_Unlock(&modinit_mutex);
224230 PyErr_SetString(PyExc_ImportError,
225231 "cannot load module more than once per process");
226232 return -1;
227233 }
228234 loaded = 1;
235+ PyMutex_Unlock(&modinit_mutex);
229236 // ... rest of initialization
230237 }
231238
232239
240+ If your module's:c:member: `PyModuleDef.m_clear ` function is able to prepare
241+ for future re-initialization, it should clear the ``loaded `` flag.
242+ In this case, your module won't support multiple instances existing
243+ *concurrently *, but it will, for example, support being loaded after
244+ Python runtime shutdown (:c:func: `Py_FinalizeEx `) and re-initialization
245+ (:c:func: `Py_Initialize `).
246+
247+
233248Module State Access from Functions
234249----------------------------------
235250