From 2c71ba75d356b7c7cc988d40a4b334f1b7b5a4a7 Mon Sep 17 00:00:00 2001 From: Matt Page Date: Thu, 14 Mar 2024 15:37:43 -0700 Subject: [PATCH] Simplify weakref creation logic Since 3.12 allocating a GC object cannot immediately trigger GC. This allows us to simplify the logic for creating the canonical callback-less weakref. --- Objects/weakrefobject.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/Objects/weakrefobject.c b/Objects/weakrefobject.c index df74be6aba72445..5ef3689e33fded6 100644 --- a/Objects/weakrefobject.c +++ b/Objects/weakrefobject.c @@ -801,24 +801,14 @@ PyWeakref_NewRef(PyObject *ob, PyObject *callback) if (result != NULL) Py_INCREF(result); else { - /* Note: new_weakref() can trigger cyclic GC, so the weakref - list on ob can be mutated. This means that the ref and - proxy pointers we got back earlier may have been collected, - so we need to compute these values again before we use - them. */ + /* We do not need to recompute ref/proxy; new_weakref() cannot + trigger GC. + */ result = new_weakref(ob, callback); if (result != NULL) { - get_basic_refs(*list, &ref, &proxy); if (callback == NULL) { if (ref == NULL) insert_head(result, list); - else { - /* Someone else added a ref without a callback - during GC. Return that one instead of this one - to avoid violating the invariants of the list - of weakrefs for ob. */ - Py_SETREF(result, (PyWeakReference*)Py_NewRef(ref)); - } } else { PyWeakReference *prev;