diff options
| -rw-r--r-- | Lib/test/test_finalization.py | 23 | ||||
| -rw-r--r-- | Lib/test/test_gc.py | 6 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2020-10-14-16-19-43.bpo-41984.SEtKMr.rst | 2 | ||||
| -rw-r--r-- | Modules/_testcapimodule.c | 20 | ||||
| -rw-r--r-- | Objects/typeobject.c | 22 |
5 files changed, 52 insertions, 21 deletions
diff --git a/Lib/test/test_finalization.py b/Lib/test/test_finalization.py index 35d7913..1d13443 100644 --- a/Lib/test/test_finalization.py +++ b/Lib/test/test_finalization.py @@ -16,6 +16,15 @@ except ImportError: raise TypeError('requires _testcapi.with_tp_del') return C +try: + from _testcapi import without_gc +except ImportError: + def without_gc(cls): + class C: + def __new__(cls, *args, **kwargs): + raise TypeError('requires _testcapi.without_gc') + return C + from test import support @@ -94,9 +103,11 @@ class SimpleBase(NonGCSimpleBase): assert self.id_ == id(self) +@without_gc class NonGC(NonGCSimpleBase): __slots__ = () +@without_gc class NonGCResurrector(NonGCSimpleBase): __slots__ = () @@ -109,8 +120,14 @@ class NonGCResurrector(NonGCSimpleBase): class Simple(SimpleBase): pass -class SimpleResurrector(NonGCResurrector, SimpleBase): - pass +# Can't inherit from NonGCResurrector, in case importing without_gc fails. +class SimpleResurrector(SimpleBase): + + def side_effect(self): + """ + Resurrect self by storing self in a class-wide list. + """ + self.survivors.append(self) class TestBase: @@ -178,6 +195,7 @@ class SimpleFinalizationTest(TestBase, unittest.TestCase): self.assert_survivors([]) self.assertIs(wr(), None) + @support.cpython_only def test_non_gc(self): with SimpleBase.test(): s = NonGC() @@ -191,6 +209,7 @@ class SimpleFinalizationTest(TestBase, unittest.TestCase): self.assert_del_calls(ids) self.assert_survivors([]) + @support.cpython_only def test_non_gc_resurrect(self): with SimpleBase.test(): s = NonGCResurrector() diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py index f52db1e..58d4613 100644 --- a/Lib/test/test_gc.py +++ b/Lib/test/test_gc.py @@ -576,9 +576,9 @@ class GCTests(unittest.TestCase): self.assertTrue(gc.is_tracked(UserInt())) self.assertTrue(gc.is_tracked([])) self.assertTrue(gc.is_tracked(set())) - self.assertFalse(gc.is_tracked(UserClassSlots())) - self.assertFalse(gc.is_tracked(UserFloatSlots())) - self.assertFalse(gc.is_tracked(UserIntSlots())) + self.assertTrue(gc.is_tracked(UserClassSlots())) + self.assertTrue(gc.is_tracked(UserFloatSlots())) + self.assertTrue(gc.is_tracked(UserIntSlots())) def test_bug1055820b(self): # Corresponds to temp2b.py in the bug report. diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-10-14-16-19-43.bpo-41984.SEtKMr.rst b/Misc/NEWS.d/next/Core and Builtins/2020-10-14-16-19-43.bpo-41984.SEtKMr.rst new file mode 100644 index 0000000..e70d5dc --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-10-14-16-19-43.bpo-41984.SEtKMr.rst @@ -0,0 +1,2 @@ +The garbage collector now tracks all user-defined classes. Patch by Brandt +Bucher. diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c index af28af5..5089f59 100644 --- a/Modules/_testcapimodule.c +++ b/Modules/_testcapimodule.c @@ -3511,6 +3511,25 @@ with_tp_del(PyObject *self, PyObject *args) return obj; } +static PyObject * +without_gc(PyObject *Py_UNUSED(self), PyObject *obj) +{ + PyTypeObject *tp = (PyTypeObject*)obj; + if (!PyType_Check(obj) || !PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE)) { + return PyErr_Format(PyExc_TypeError, "heap type expected, got %R", obj); + } + if (PyType_IS_GC(tp)) { + // Don't try this at home, kids: + tp->tp_flags -= Py_TPFLAGS_HAVE_GC; + tp->tp_free = PyObject_Del; + tp->tp_traverse = NULL; + tp->tp_clear = NULL; + } + assert(!PyType_IS_GC(tp)); + Py_INCREF(obj); + return obj; +} + static PyMethodDef ml; static PyObject * @@ -5325,6 +5344,7 @@ static PyMethodDef TestMethods[] = { #endif {"write_unraisable_exc", test_write_unraisable_exc, METH_VARARGS}, {"pynumber_tobase", pynumber_tobase, METH_VARARGS}, + {"without_gc", without_gc, METH_O}, {NULL, NULL} /* sentinel */ }; diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 0acde71..21b1360 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -2577,10 +2577,10 @@ type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds) slots = NULL; /* Initialize tp_flags */ + // All heap types need GC, since we can create a reference cycle by storing + // an instance on one of its parents: type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HEAPTYPE | - Py_TPFLAGS_BASETYPE; - if (base->tp_flags & Py_TPFLAGS_HAVE_GC) - type->tp_flags |= Py_TPFLAGS_HAVE_GC; + Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC; /* Initialize essential fields */ type->tp_as_async = &et->as_async; @@ -2777,21 +2777,11 @@ type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds) } type->tp_dealloc = subtype_dealloc; - /* Enable GC unless this class is not adding new instance variables and - the base class did not use GC. */ - if ((base->tp_flags & Py_TPFLAGS_HAVE_GC) || - type->tp_basicsize > base->tp_basicsize) - type->tp_flags |= Py_TPFLAGS_HAVE_GC; - /* Always override allocation strategy to use regular heap */ type->tp_alloc = PyType_GenericAlloc; - if (type->tp_flags & Py_TPFLAGS_HAVE_GC) { - type->tp_free = PyObject_GC_Del; - type->tp_traverse = subtype_traverse; - type->tp_clear = subtype_clear; - } - else - type->tp_free = PyObject_Del; + type->tp_free = PyObject_GC_Del; + type->tp_traverse = subtype_traverse; + type->tp_clear = subtype_clear; /* store type in class' cell if one is supplied */ cell = _PyDict_GetItemIdWithError(dict, &PyId___classcell__); |