From 5580f9513f914396172a40f0dc0d2c056843bfe5 Mon Sep 17 00:00:00 2001 From: mpage Date: Fri, 15 Mar 2024 06:58:40 -0700 Subject: [PATCH] gh-111926: Simplify proxy creation logic (#116844) Since 3.12, allocating a GC-able object cannot trigger GC. This allows us to simplify the logic for creating the canonical callback-less proxy object. --- Objects/weakrefobject.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/Objects/weakrefobject.c b/Objects/weakrefobject.c index 6264b1825eda731..b7b29064151609f 100644 --- a/Objects/weakrefobject.c +++ b/Objects/weakrefobject.c @@ -848,11 +848,9 @@ PyWeakref_NewProxy(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) { PyWeakReference *prev; @@ -863,16 +861,7 @@ PyWeakref_NewProxy(PyObject *ob, PyObject *callback) else { Py_SET_TYPE(result, &_PyWeakref_ProxyType); } - get_basic_refs(*list, &ref, &proxy); if (callback == NULL) { - if (proxy != NULL) { - /* Someone else added a proxy 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(proxy)); - goto skip_insert; - } prev = ref; } else @@ -882,8 +871,6 @@ PyWeakref_NewProxy(PyObject *ob, PyObject *callback) insert_head(result, list); else insert_after(result, prev); - skip_insert: - ; } } return (PyObject *) result;