Finish rebase against main.

Author: ZeroIntensity

Modules/_testcapimodule.c

@@ -3310,6 +3310,50 @@ test_critical_sections(PyObject *module, PyObject *Py_UNUSED(args))
     Py_RETURN_NONE;
 }
 
+
+// Used by `finalize_thread_hang`.
+#ifdef _POSIX_THREADS
+static void finalize_thread_hang_cleanup_callback(void *Py_UNUSED(arg)) {
+    // Should not reach here.
+    Py_FatalError("pthread thread termination was triggered unexpectedly");
+}
+#endif
+
+// Tests that finalization does not trigger pthread cleanup.
+//
+// Must be called with a single nullary callable function that should block
+// (with GIL released) until finalization is in progress.
+static PyObject *
+finalize_thread_hang(PyObject *self, PyObject *callback)
+{
+    // WASI builds some pthread stuff but doesn't have these APIs today?
+#if defined(_POSIX_THREADS) && !defined(__wasi__)
+    pthread_cleanup_push(finalize_thread_hang_cleanup_callback, NULL);
+#endif
+    PyObject_CallNoArgs(callback);
+    // Should not reach here.
+    Py_FatalError("thread unexpectedly did not hang");
+#if defined(_POSIX_THREADS) && !defined(__wasi__)
+    pthread_cleanup_pop(0);
+#endif
+    Py_RETURN_NONE;
+}
+
+
+static PyObject *
+type_freeze(PyObject *module, PyObject *args)
+{
+    PyTypeObject *type;
+    if (!PyArg_ParseTuple(args, "O!", &PyType_Type, &type)) {
+        return NULL;
+    }
+    if (PyType_Freeze(type) < 0) {
+        return NULL;
+    }
+    Py_RETURN_NONE;
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -3449,6 +3493,8 @@ static PyMethodDef TestMethods[] = {
     {"test_weakref_capi", test_weakref_capi, METH_NOARGS},
     {"function_set_warning", function_set_warning, METH_NOARGS},
     {"test_critical_sections", test_critical_sections, METH_NOARGS},
+    {"finalize_thread_hang", finalize_thread_hang, METH_O, NULL},
+    {"type_freeze", type_freeze, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };