https://github.com/python/cpython/commit/1f16b4ce569f222af74fcbb7b2ef98eee23... commit: 1f16b4ce569f222af74fcbb7b2ef98eee2398d20 branch: main author: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> committer: iritkatriel <1055913+iritkatriel@users.noreply.github.com> date: 2024-04-30T19:32:25+01:00 summary: gh-118272: Clear generator frame's locals when the generator is closed (#118277) Co-authored-by: Thomas Grainger <tagrain@gmail.com> files: A Misc/NEWS.d/next/Core and Builtins/2024-04-25-12-55-47.gh-issue-118272.5ptjk_.rst M Include/internal/pycore_frame.h M Lib/test/test_generators.py M Objects/genobject.c M Python/frame.c diff --git a/Include/internal/pycore_frame.h b/Include/internal/pycore_frame.h index f913928f38bd05..37ae5ae850389b 100644 --- a/Include/internal/pycore_frame.h +++ b/Include/internal/pycore_frame.h @@ -227,6 +227,9 @@ _PyFrame_GetFrameObject(_PyInterpreterFrame *frame) return _PyFrame_MakeAndSetFrameObject(frame); } +void +_PyFrame_ClearLocals(_PyInterpreterFrame *frame); + /* Clears all references in the frame. * If take is non-zero, then the _PyInterpreterFrame frame * may be transferred to the frame object it references diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index d48f0d47ba1962..6d36df2c7413e0 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -532,6 +532,26 @@ def f(): with self.assertRaises(RuntimeError): gen.close() + def test_close_releases_frame_locals(self): + # See gh-118272 + + class Foo: + pass + + f = Foo() + f_wr = weakref.ref(f) + + def genfn(): + a = f + yield + + g = genfn() + next(g) + del f + g.close() + support.gc_collect() + self.assertIsNone(f_wr()) + class GeneratorThrowTest(unittest.TestCase): diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-04-25-12-55-47.gh-issue-118272.5ptjk_.rst b/Misc/NEWS.d/next/Core and Builtins/2024-04-25-12-55-47.gh-issue-118272.5ptjk_.rst new file mode 100644 index 00000000000000..32043440fd0365 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2024-04-25-12-55-47.gh-issue-118272.5ptjk_.rst @@ -0,0 +1,2 @@ +Fix bug where ``generator.close`` does not free the generator frame's +locals. diff --git a/Objects/genobject.c b/Objects/genobject.c index 5d7da49cfca166..04736a04562e14 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -380,6 +380,7 @@ gen_close(PyGenObject *gen, PyObject *args) // RESUME after YIELD_VALUE and exception depth is 1 assert((oparg & RESUME_OPARG_LOCATION_MASK) != RESUME_AT_FUNC_START); gen->gi_frame_state = FRAME_COMPLETED; + _PyFrame_ClearLocals((_PyInterpreterFrame *)gen->gi_iframe); Py_RETURN_NONE; } } diff --git a/Python/frame.c b/Python/frame.c index db9d13359a23ca..ec390e7426ad47 100644 --- a/Python/frame.c +++ b/Python/frame.c @@ -94,6 +94,17 @@ take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame) } } +void +_PyFrame_ClearLocals(_PyInterpreterFrame *frame) +{ + assert(frame->stacktop >= 0); + for (int i = 0; i < frame->stacktop; i++) { + Py_XDECREF(frame->localsplus[i]); + } + frame->stacktop = 0; + Py_CLEAR(frame->f_locals); +} + void _PyFrame_ClearExceptCode(_PyInterpreterFrame *frame) { @@ -114,11 +125,7 @@ _PyFrame_ClearExceptCode(_PyInterpreterFrame *frame) } Py_DECREF(f); } - assert(frame->stacktop >= 0); - for (int i = 0; i < frame->stacktop; i++) { - Py_XDECREF(frame->localsplus[i]); - } - Py_XDECREF(frame->f_locals); + _PyFrame_ClearLocals(frame); Py_DECREF(frame->f_funcobj); }