Close owned guards before deallocating the thread state, not after.

Author: ZeroIntensity

Modules/_testcapimodule.c

@@ -2709,10 +2709,7 @@ test_thread_state_ensure_crossinterp(PyObject *self, PyObject *unused)
     PyInterpreterGuard *guard = PyInterpreterGuard_FromCurrent();
     PyThreadState *save_tstate = PyThreadState_Swap(NULL);
     PyThreadState *interp_tstate = Py_NewInterpreter();
-    if (interp_tstate == NULL) {
-        PyInterpreterGuard_Close(guard);
-        return PyErr_NoMemory();
-    }
+    assert(interp_tstate != NULL);
 
     /* This should create a new thread state for the calling interpreter, *not*
        reactivate the old one. In a real-world scenario, this would arise in
@@ -2728,24 +2725,17 @@ test_thread_state_ensure_crossinterp(PyObject *self, PyObject *unused)
        interp.exec(some_func)
        */
     PyThreadState *thread_state = PyThreadState_Ensure(guard);
-    if (thread_state == NULL) {
-        PyInterpreterGuard_Close(guard);
-        return PyErr_NoMemory();
-    }
+    assert(thread_state != NULL);
 
     PyThreadState *ensured_tstate = PyThreadState_Get();
     assert(ensured_tstate != save_tstate);
     assert(PyGILState_GetThisThreadState() == ensured_tstate);
 
     // Now though, we should reactivate the thread state
     PyThreadState *other_thread_state = PyThreadState_Ensure(guard);
-    if (other_thread_state == NULL) {
-        PyThreadState_Release(thread_state);
-        PyInterpreterGuard_Close(guard);
-        return PyErr_NoMemory();
-    }
-
+    assert(other_thread_state != NULL);
     assert(PyThreadState_Get() == ensured_tstate);
+
     PyThreadState_Release(other_thread_state);
 
     // Ensure that we're restoring the prior thread state

Python/pystate.c

@@ -3595,14 +3595,18 @@ PyThreadState_Release(PyThreadState *old_tstate)
     assert(tstate->ensure.delete_on_release == 1 || tstate->ensure.delete_on_release == 0);
     if (tstate->ensure.delete_on_release) {
         PyThreadState_Clear(tstate);
-        PyThreadState_Swap(to_restore);
-        PyThreadState_Delete(tstate);
     } else {
         PyThreadState_Swap(to_restore);
     }
 
+    PyThreadState_Swap(to_restore);
+
     if (tstate->ensure.owned_guard != NULL) {
         PyInterpreterGuard_Close(tstate->ensure.owned_guard);
         tstate->ensure.owned_guard = NULL;
     }
+
+    if (tstate->ensure.delete_on_release) {
+        PyThreadState_Delete(tstate);
+    }
 }