gh-129824: Fix data races in type_ready with subinterpreters

Also add test_interpreters to the list of TSAN tests. The test_running
and test_is_running test cases are skipped for now as they have file
descriptor races.

Author: colesbury

Lib/test/libregrtest/tsan.py

@@ -11,6 +11,7 @@
     'test_httpservers',
     'test_imaplib',
     'test_importlib',
+    'test_interpreters',
     'test_io',
     'test_logging',
     'test_queue',

Lib/test/test_interpreters/test_api.py

@@ -703,6 +703,7 @@ def test_not_shareable(self):
         with self.assertRaises(ExecutionFailed):
             interp.exec('print(spam)')
 
+    @support.skip_if_sanitizer('gh-129824: file descriptor race', thread=True)
     def test_running(self):
         interp = interpreters.create()
         interp.prepare_main({'spam': True})
@@ -1530,6 +1531,7 @@ def test_whence(self):
             whence = eval(text)
             self.assertEqual(whence, _interpreters.WHENCE_LEGACY_CAPI)
 
+    @support.skip_if_sanitizer('gh-129824: file descriptor race', thread=True)
     def test_is_running(self):
         def check(interpid, expected):
             with self.assertRaisesRegex(InterpreterError, 'unrecognized'):

Objects/typeobject.c

@@ -8506,7 +8506,12 @@ type_ready_set_new(PyTypeObject *type, int initial)
         && base == &PyBaseObject_Type
         && !(type->tp_flags & Py_TPFLAGS_HEAPTYPE))
     {
-        type->tp_flags |= Py_TPFLAGS_DISALLOW_INSTANTIATION;
+        if (initial) {
+            type->tp_flags |= Py_TPFLAGS_DISALLOW_INSTANTIATION;
+        }
+        else {
+            assert(_PyType_HasFeature(type, Py_TPFLAGS_DISALLOW_INSTANTIATION));
+        }
     }
 
     if (!(type->tp_flags & Py_TPFLAGS_DISALLOW_INSTANTIATION)) {
@@ -8526,7 +8531,12 @@ type_ready_set_new(PyTypeObject *type, int initial)
     }
     else {
         // Py_TPFLAGS_DISALLOW_INSTANTIATION sets tp_new to NULL
-        type->tp_new = NULL;
+        if (initial) {
+            type->tp_new = NULL;
+        }
+        else {
+            assert(type->tp_new == NULL);
+        }
     }
     return 0;
 }
@@ -8659,7 +8669,12 @@ type_ready(PyTypeObject *type, int initial)
     }
 
     /* All done -- set the ready flag */
-    type->tp_flags |= Py_TPFLAGS_READY;
+    if (initial) {
+        type->tp_flags |= Py_TPFLAGS_READY;
+    }
+    else {
+        assert(_PyType_HasFeature(type, Py_TPFLAGS_READY));
+    }
     stop_readying(type);
 
     assert(_PyType_CheckConsistency(type));