bpo-39947: Add _PyThreadState_GetDict()

Include/cpython/pystate.h

@@ -149,6 +149,8 @@ PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *);
  * if it is NULL. */
 PyAPI_FUNC(PyThreadState *) _PyThreadState_UncheckedGet(void);
 
+PyAPI_FUNC(PyObject *) _PyThreadState_GetDict(PyThreadState *tstate);
+
 /* PyGILState */
 
 /* Helper/diagnostic function - return 1 if the current thread

Modules/_asynciomodule.c

@@ -236,12 +236,13 @@ get_running_loop(PyObject **loop)
         rl = cached_running_holder;  // borrowed
     }
     else {
-        if (ts->dict == NULL) {
+        PyObject *ts_dict = _PyThreadState_GetDict(ts);  // borrowed
+        if (ts_dict == NULL) {
             goto not_found;
         }
 
         rl = _PyDict_GetItemIdWithError(
-            ts->dict, &PyId___asyncio_running_event_loop__);  // borrowed
+            ts_dict, &PyId___asyncio_running_event_loop__);  // borrowed
         if (rl == NULL) {
             if (PyErr_Occurred()) {
                 goto error;

Python/pystate.c

@@ -4,9 +4,10 @@
 #include "Python.h"
 #include "pycore_ceval.h"
 #include "pycore_initconfig.h"
+#include "pycore_pyerrors.h"
+#include "pycore_pylifecycle.h"
 #include "pycore_pymem.h"
 #include "pycore_pystate.h"
-#include "pycore_pylifecycle.h"
 
 /* --------------------------------------------------------------------------
 CAUTION
@@ -979,20 +980,28 @@ PyThreadState_Swap(PyThreadState *newts)
    PyThreadState_GetDict() returns NULL, an exception has *not* been raised
    and the caller should assume no per-thread state is available. */
 
+PyObject *
+_PyThreadState_GetDict(PyThreadState *tstate)
+{
+    assert(tstate != NULL);
+    if (tstate->dict == NULL) {
+        tstate->dict = PyDict_New();
+        if (tstate->dict == NULL) {
+            _PyErr_Clear(tstate);
+        }
+    }
+    return tstate->dict;
+}
+
+
 PyObject *
 PyThreadState_GetDict(void)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    if (tstate == NULL)
+    if (tstate == NULL) {
         return NULL;
-
-    if (tstate->dict == NULL) {
-        PyObject *d;
-        tstate->dict = d = PyDict_New();
-        if (d == NULL)
-            PyErr_Clear();
     }
-    return tstate->dict;
+    return _PyThreadState_GetDict(tstate);
 }