bpo-36427: Document that PyEval_RestoreThread and PyGILState_Ensure can terminate the calling thread (GH-12541)
Calling these function from a thread when the runtime is finalizing will terminate
the thread, even if the thread was not created by Python. Users can use
_Py_IsFinalizing or sys.is_finalizing to check if the interpreter is in the process of
being finalized before calling this function to avoid unwanted termination.
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index 7c1f0ff..7ef1122 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -856,6 +856,12 @@
created, the current thread must not have acquired it, otherwise deadlock
ensues.
+ .. note::
+ Calling this function from a thread when the runtime is finalizing
+ will terminate the thread, even if the thread was not created by Python.
+ You can use :c:func:`_Py_IsFinalizing` or :func:`sys.is_finalizing` to
+ check if the interpreter is in process of being finalized before calling
+ this function to avoid unwanted termination.
.. c:function:: PyThreadState* PyThreadState_Get()
@@ -903,6 +909,12 @@
When the function returns, the current thread will hold the GIL and be able
to call arbitrary Python code. Failure is a fatal error.
+ .. note::
+ Calling this function from a thread when the runtime is finalizing
+ will terminate the thread, even if the thread was not created by Python.
+ You can use :c:func:`_Py_IsFinalizing` or :func:`sys.is_finalizing` to
+ check if the interpreter is in process of being finalized before calling
+ this function to avoid unwanted termination.
.. c:function:: void PyGILState_Release(PyGILState_STATE)