diff options
Diffstat (limited to 'Python/gc_free_threading.c')
| -rw-r--r-- | Python/gc_free_threading.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/Python/gc_free_threading.c b/Python/gc_free_threading.c index 5aaa68c5b51..d46598b23b3 100644 --- a/Python/gc_free_threading.c +++ b/Python/gc_free_threading.c @@ -1492,9 +1492,9 @@ move_legacy_finalizer_reachable(struct collection_state *state) } // Clear all weakrefs to unreachable objects. Weakrefs with callbacks are -// enqueued in `wrcb_to_call`, but not invoked yet. +// optionally enqueued in `wrcb_to_call`, but not invoked yet. static void -clear_weakrefs(struct collection_state *state) +clear_weakrefs(struct collection_state *state, bool enqueue_callbacks) { PyObject *op; WORKSTACK_FOR_EACH(&state->unreachable, op) { @@ -1526,6 +1526,10 @@ clear_weakrefs(struct collection_state *state) _PyWeakref_ClearRef(wr); _PyObject_ASSERT((PyObject *)wr, wr->wr_object == Py_None); + if (!enqueue_callbacks) { + continue; + } + // We do not invoke callbacks for weakrefs that are themselves // unreachable. This is partly for historical reasons: weakrefs // predate safe object finalization, and a weakref that is itself @@ -2211,7 +2215,7 @@ gc_collect_internal(PyInterpreterState *interp, struct collection_state *state, interp->gc.long_lived_total = state->long_lived_total; // Clear weakrefs and enqueue callbacks (but do not call them). - clear_weakrefs(state); + clear_weakrefs(state, true); _PyEval_StartTheWorld(interp); // Deallocate any object from the refcount merge step @@ -2222,11 +2226,19 @@ gc_collect_internal(PyInterpreterState *interp, struct collection_state *state, call_weakref_callbacks(state); finalize_garbage(state); - // Handle any objects that may have resurrected after the finalization. _PyEval_StopTheWorld(interp); + // Handle any objects that may have resurrected after the finalization. err = handle_resurrected_objects(state); // Clear free lists in all threads _PyGC_ClearAllFreeLists(interp); + if (err == 0) { + // Clear weakrefs to objects in the unreachable set. No Python-level + // code must be allowed to access those unreachable objects. During + // delete_garbage(), finalizers outside the unreachable set might + // run and create new weakrefs. If those weakrefs were not cleared, + // they could reveal unreachable objects. + clear_weakrefs(state, false); + } _PyEval_StartTheWorld(interp); if (err < 0) { |