Move the _PyObject_InitState() call out of init_interpreter().

Objects/object.c

@@ -210,69 +210,19 @@ refchain_fini(PyInterpreterState *interp)
     if (has_own_refchain(interp)) {
         _Py_hashtable_destroy(REFCHAIN(interp));
     }
-    // This extra branch can be removed once we start setting
-    // interp->feature_flags *before* refchain_init() gets called.
-    else if (REFCHAIN(interp) != REFCHAIN(_PyInterpreterState_Main())) {
-        _Py_hashtable_destroy(REFCHAIN(interp));
-    }
     REFCHAIN(interp) = NULL;
 }
 
-/* Currently refchain_init() is called during interpreter initialization,
-   via _PyObject_InitState(), before interp->feature_flags is set,
-   so an interpreter may have its own refchain even though it shouldn't.
-   Until that gets fixed, we patch it all up wherever apprpriate.
-  maybe_fix_refchain() and move_refchain_item() can be dropped
-  once we sort out the init order problem. */
-
-static int
-copy_refchain_item(_Py_hashtable_t *ht,
-                   const void *key, const void *value,
-                   void *user_data)
-{
-    if (value != REFCHAIN_VALUE) {
-        assert(value == NULL);
-        return 0;
-    }
-    _Py_hashtable_t *new_chain = (_Py_hashtable_t *)user_data;
-    if (_Py_hashtable_set(new_chain, key, REFCHAIN_VALUE) < 0) {
-        Py_FatalError("_Py_hashtable_set() memory allocation failed");
-    }
-    return 0;
-}
-
-static void
-maybe_fix_refchain(PyInterpreterState *interp)
-{
-    if (has_own_refchain(interp)) {
-        // It's okay or we haven't set the feature flags correctly yet.
-        return;
-    }
-
-    _Py_hashtable_t *cur_chain = REFCHAIN(interp);
-    _Py_hashtable_t *main_chain = REFCHAIN(_PyInterpreterState_Main());
-    if (cur_chain == main_chain) {
-        // It was already fixed.
-        return;
-    }
-    REFCHAIN(interp) = main_chain;
-
-    (void)_Py_hashtable_foreach(cur_chain, copy_refchain_item, main_chain);
-    _Py_hashtable_destroy(cur_chain);
-}
-
 bool
 _PyRefchain_IsTraced(PyInterpreterState *interp, PyObject *obj)
 {
-    maybe_fix_refchain(interp);
     return (_Py_hashtable_get(REFCHAIN(interp), obj) == REFCHAIN_VALUE);
 }
 
 
 static void
 _PyRefchain_Trace(PyInterpreterState *interp, PyObject *obj)
 {
-    maybe_fix_refchain(interp);
     if (_Py_hashtable_set(REFCHAIN(interp), obj, REFCHAIN_VALUE) < 0) {
         // Use a fatal error because _Py_NewReference() cannot report
         // the error to the caller.
@@ -284,7 +234,6 @@ _PyRefchain_Trace(PyInterpreterState *interp, PyObject *obj)
 static void
 _PyRefchain_Remove(PyInterpreterState *interp, PyObject *obj)
 {
-    maybe_fix_refchain(interp);
     void *value = _Py_hashtable_steal(REFCHAIN(interp), obj);
 #ifndef NDEBUG
     assert(value == REFCHAIN_VALUE);
@@ -2630,7 +2579,6 @@ _Py_PrintReferences(PyInterpreterState *interp, FILE *fp)
         interp = _PyInterpreterState_Main();
     }
     fprintf(fp, "Remaining objects:\n");
-    maybe_fix_refchain(interp);
     _Py_hashtable_foreach(REFCHAIN(interp), _Py_PrintReference, fp);
 }
 
@@ -2659,7 +2607,6 @@ void
 _Py_PrintReferenceAddresses(PyInterpreterState *interp, FILE *fp)
 {
     fprintf(fp, "Remaining object addresses:\n");
-    maybe_fix_refchain(interp);
     _Py_hashtable_foreach(REFCHAIN(interp), _Py_PrintReferenceAddress, fp);
 }
 
@@ -2739,7 +2686,6 @@ _Py_GetObjects(PyObject *self, PyObject *args)
         .limit = limit,
     };
     PyInterpreterState *interp = _PyInterpreterState_GET();
-    maybe_fix_refchain(interp);
     int res = _Py_hashtable_foreach(REFCHAIN(interp), _Py_GetObject, &data);
     if (res == _PY_GETOBJECTS_ERROR) {
         Py_DECREF(list);

Python/pylifecycle.c

@@ -674,6 +674,13 @@ pycore_create_interpreter(_PyRuntimeState *runtime,
         return status;
     }
 
+    // This could be done in init_interpreter() (in pystate.c) if it
+    // didn't depend on interp->feature_flags being set already.
+    status = _PyObject_InitState(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
     // initialize the interp->obmalloc state.  This must be done after
     // the settings are loaded (so that feature_flags are set) but before
     // any calls are made to obmalloc functions.
@@ -2297,6 +2304,13 @@ new_interpreter(PyThreadState **tstate_p,
         goto error;
     }
 
+    // This could be done in init_interpreter() (in pystate.c) if it
+    // didn't depend on interp->feature_flags being set already.
+    status = _PyObject_InitState(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
     // initialize the interp->obmalloc state.  This must be done after
     // the settings are loaded (so that feature_flags are set) but before
     // any calls are made to obmalloc functions.

Python/pystate.c

@@ -629,13 +629,8 @@ init_interpreter(PyInterpreterState *interp,
     assert(next != NULL || (interp == runtime->interpreters.main));
     interp->next = next;
 
-    // This relies on interp->feature_flags being set already,
-    // but currently we don't set that by this point.
-    // That's something to fix.
-    PyStatus status = _PyObject_InitState(interp);
-    if (_PyStatus_EXCEPTION(status)) {
-        return status;
-    }
+    // We would call _PyObject_InitState() at this point
+    // if interp->feature_flags were alredy set.
 
     _PyEval_InitState(interp);
     _PyGC_InitState(&interp->gc);