https://github.com/python/cpython/commit/9cef5c1f65d884f73f5ed1d7191a5621232e17b0 commit: 9cef5c1f65d884f73f5ed1d7191a5621232e17b0 branch: 3.14 author: Miss Islington (bot) <[email protected]> committer: encukou <[email protected]> date: 2025-05-22T10:20:11+02:00 summary:
[3.14] Add notes on nogil & reinitialization to the Opt-Out section in Module Isolation HOWTO (GH-134141) (GH-134492) Add notes on nogil & reinitialization to the Opt-Out section in Module Isolation HOWTO (GH-134141) (cherry picked from commit 1f0a294e8c2ff009c6b74ca5aa71da6269aec0dd) Co-authored-by: Petr Viktorin <[email protected]> Co-authored-by: Sam Gross <[email protected]> files: M Doc/howto/isolating-extensions.rst diff --git a/Doc/howto/isolating-extensions.rst b/Doc/howto/isolating-extensions.rst index a636e06bda8344..5513cd7367519f 100644 --- a/Doc/howto/isolating-extensions.rst +++ b/Doc/howto/isolating-extensions.rst @@ -215,21 +215,36 @@ multiple interpreters correctly. If this is not yet the case for your module, you can explicitly make your module loadable only once per process. For example:: + // A process-wide flag static int loaded = 0; + // Mutex to provide thread safety (only needed for free-threaded Python) + static PyMutex modinit_mutex = {0}; + static int exec_module(PyObject* module) { + PyMutex_Lock(&modinit_mutex); if (loaded) { + PyMutex_Unlock(&modinit_mutex); PyErr_SetString(PyExc_ImportError, "cannot load module more than once per process"); return -1; } loaded = 1; + PyMutex_Unlock(&modinit_mutex); // ... rest of initialization } +If your module's :c:member:`PyModuleDef.m_clear` function is able to prepare +for future re-initialization, it should clear the ``loaded`` flag. +In this case, your module won't support multiple instances existing +*concurrently*, but it will, for example, support being loaded after +Python runtime shutdown (:c:func:`Py_FinalizeEx`) and re-initialization +(:c:func:`Py_Initialize`). + + Module State Access from Functions ---------------------------------- _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
