fix(structseq): track struct_time and asyncgen_hooks in GC

Author: ashm-dev

Doc/c-api/tuple.rst

@@ -232,6 +232,10 @@ type.
    Creates an instance of *type*, which must have been created with
    :c:func:`PyStructSequence_NewType`.
 
+   The returned instance is not tracked by the garbage collector. If the
+   instance can contain objects that participate in reference cycles, call
+   :c:func:`PyObject_GC_Track` after populating its fields.
+
    Return ``NULL`` with an exception set on failure.
 
 

Lib/test/test_structseq.py

@@ -366,9 +366,11 @@ def test_replace_gc_tracked(self):
         self.assertTrue(gc.is_tracked(replaced_struct))
 
     def test_gc_tracked(self):
-        # PyStructSequence objects created via C API or Python should be GC-tracked
+        # Instances created via Python or stdlib callers that may participate
+        # in cycles are GC-tracked; simple instances like os.stat_result are not.
         self.assertTrue(gc.is_tracked(time.gmtime()))
-        self.assertTrue(gc.is_tracked(os.stat(__file__)))
+        self.assertTrue(gc.is_tracked(time.struct_time((2020, 1, 1, 0, 0, 0, 0, 1, 0))))
+        self.assertFalse(gc.is_tracked(os.stat(__file__)))
 
 if __name__ == "__main__":
     unittest.main()

Lib/test/test_sys.py

@@ -1969,6 +1969,7 @@ def test_asyncgen_hooks(self):
 
         sys.set_asyncgen_hooks(firstiter=firstiter)
         hooks = sys.get_asyncgen_hooks()
+        self.assertTrue(gc.is_tracked(hooks))
         self.assertIs(hooks.firstiter, firstiter)
         self.assertIs(hooks[0], firstiter)
         self.assertIs(hooks.finalizer, None)

Misc/NEWS.d/next/Core_and_Builtins/2026-09-08-15-55-00.gh-issue-157176.yZ8a1B.rst

@@ -1 +1 @@
-Fix GC tracking for :class:`!PyStructSequence` instances created via :c:func:`PyStructSequence_New`. Patch by Shamil Abdulaev.
+Track :func:`time.struct_time` and :func:`sys.get_asyncgen_hooks` objects in the garbage collector to prevent reference cycle leaks. Patch by Shamil Abdulaev.

Modules/timemodule.c

@@ -497,6 +497,7 @@ tmtotuple(time_module_state *state, struct tm *p
 #undef SET
 #undef SET_ITEM
 
+    PyObject_GC_Track(v);
     return v;
 }
 

Objects/structseq.c

@@ -84,7 +84,6 @@ PyStructSequence_New(PyTypeObject *type)
     for (i = 0; i < size; i++)
         obj->ob_item[i] = NULL;
 
-    _PyObject_GC_TRACK(obj);
     return (PyObject*)obj;
 }
 
@@ -266,6 +265,7 @@ structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
         }
     }
 
+    _PyObject_GC_TRACK(res);
     return (PyObject*) res;
 }
 
@@ -449,6 +449,7 @@ structseq_replace(PyObject *op, PyObject *args, PyObject *kwargs)
         }
     }
 
+    _PyObject_GC_TRACK(result);
     return (PyObject *)result;
 
 error:

Python/sysmodule.c

@@ -1531,6 +1531,7 @@ sys_get_asyncgen_hooks_impl(PyObject *module)
     PyStructSequence_SET_ITEM(res, 0, Py_NewRef(firstiter));
     PyStructSequence_SET_ITEM(res, 1, Py_NewRef(finalizer));
 
+    PyObject_GC_Track(res);
     return res;
 }