Make itertools.tee and its internal teedataobject participate in GC. This

alone does not solve the leak in test_generators, unfortunately, but it is
part of test_generators' problem and it does solve other cycles.

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 49d241fcac1624b3dbfef1c0c3939c59dd6ff05e..71081fbe43b6f13b84265bbe75d4f0753efd4a03 100644 (file)
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -340,7 +340,7 @@ teedataobject_new(PyObject *it)
 {
        teedataobject *tdo;
 
-       tdo = PyObject_New(teedataobject, &teedataobject_type);
+       tdo = PyObject_GC_New(teedataobject, &teedataobject_type);
        if (tdo == NULL)
                return NULL;
 
@@ -348,6 +348,7 @@ teedataobject_new(PyObject *it)
        tdo->nextlink = NULL;
        Py_INCREF(it);
        tdo->it = it;
+       PyObject_GC_Track(tdo);
        return (PyObject *)tdo;
 }
 
@@ -381,16 +382,34 @@ teedataobject_getitem(teedataobject *tdo, int i)
        return value;
 }
 
-static void
-teedataobject_dealloc(teedataobject *tdo)
+static int
+teedataobject_traverse(teedataobject *tdo, visitproc visit, void * arg)
 {
        int i;
+       Py_VISIT(tdo->it);
+       for (i = 0; i < tdo->numread; i++)
+               Py_VISIT(tdo->values[i]);
+       Py_VISIT(tdo->nextlink);
+       return 0;
+}
 
+static int
+teedataobject_clear(teedataobject *tdo)
+{
+       int i;
+       Py_CLEAR(tdo->it);
        for (i=0 ; i<tdo->numread ; i++)
-               Py_DECREF(tdo->values[i]);
-       Py_XDECREF(tdo->it);
-       Py_XDECREF(tdo->nextlink);
-       PyObject_Del(tdo);
+               Py_CLEAR(tdo->values[i]);
+       Py_CLEAR(tdo->nextlink);
+       return 0;
+}
+
+static void
+teedataobject_dealloc(teedataobject *tdo)
+{
+       PyObject_GC_UnTrack(tdo);
+       teedataobject_clear(tdo);
+       PyObject_GC_Del(tdo);
 }
 
 PyDoc_STRVAR(teedataobject_doc, "Data container common to multiple tee objects.");
@@ -417,9 +436,26 @@ static PyTypeObject teedataobject_type = {
        PyObject_GenericGetAttr,                /* tp_getattro */
        0,                                      /* tp_setattro */
        0,                                      /* tp_as_buffer */
-       Py_TPFLAGS_DEFAULT,                     /* tp_flags */
+       Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,        /* tp_flags */
        teedataobject_doc,                      /* tp_doc */
-       0,                                      /* tp_traverse */
+       (traverseproc)teedataobject_traverse,   /* tp_traverse */
+       (inquiry)teedataobject_clear,           /* tp_clear */
+       0,                                      /* tp_richcompare */
+       0,                                      /* tp_weaklistoffset */
+       0,                                      /* tp_iter */
+       0,                                      /* tp_iternext */
+       0,                                      /* tp_methods */
+       0,                                      /* tp_members */
+       0,                                      /* tp_getset */
+       0,                                      /* tp_base */
+       0,                                      /* tp_dict */
+       0,                                      /* tp_descr_get */
+       0,                                      /* tp_descr_set */
+       0,                                      /* tp_dictoffset */
+       0,                                      /* tp_init */
+       0,                                      /* tp_alloc */
+       0,                                      /* tp_new */
+       PyObject_GC_Del,                        /* tp_free */
 };
 
 
@@ -443,12 +479,19 @@ tee_next(teeobject *to)
        return value;
 }
 
+static int
+tee_traverse(teeobject *to, visitproc visit, void *arg)
+{
+       Py_VISIT((PyObject *)to->dataobj);
+       return 0;
+}
+
 static PyObject *
 tee_copy(teeobject *to)
 {
        teeobject *newto;
 
-       newto = PyObject_New(teeobject, &tee_type);
+       newto = PyObject_GC_New(teeobject, &tee_type);
        if (newto == NULL)
                return NULL;
        Py_INCREF(to->dataobj);
@@ -474,12 +517,13 @@ tee_fromiterable(PyObject *iterable)
                goto done;
        }
 
-       to = PyObject_New(teeobject, &tee_type);
+       to = PyObject_GC_New(teeobject, &tee_type);
        if (to == NULL) 
                goto done;
        to->dataobj = (teedataobject *)teedataobject_new(it);
        to->index = 0;
        to->weakreflist = NULL;
+       PyObject_GC_Track(to);
 done:
        Py_XDECREF(it);
        return (PyObject *)to;
@@ -495,13 +539,21 @@ tee_new(PyTypeObject *type, PyObject *args, PyObject *kw)
        return tee_fromiterable(iterable);
 }
 
-static void
-tee_dealloc(teeobject *to)
+static int
+tee_clear(teeobject *to)
 {
        if (to->weakreflist != NULL)
                PyObject_ClearWeakRefs((PyObject *) to);
-       Py_XDECREF(to->dataobj);
-       PyObject_Del(to);
+       Py_CLEAR(to->dataobj);
+       return 0;
+}
+
+static void
+tee_dealloc(teeobject *to)
+{
+       PyObject_GC_UnTrack(to);
+       tee_clear(to);
+       PyObject_GC_Del(to);
 }
 
 PyDoc_STRVAR(teeobject_doc,
@@ -534,10 +586,10 @@ static PyTypeObject tee_type = {
        0,                              /* tp_getattro */
        0,                              /* tp_setattro */
        0,                              /* tp_as_buffer */
-       Py_TPFLAGS_DEFAULT,             /* tp_flags */
+       Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,        /* tp_flags */
        teeobject_doc,                  /* tp_doc */
-       0,                              /* tp_traverse */
-       0,                              /* tp_clear */
+       (traverseproc)tee_traverse,     /* tp_traverse */
+       (inquiry)tee_clear,             /* tp_clear */
        0,                              /* tp_richcompare */
        offsetof(teeobject, weakreflist),       /* tp_weaklistoffset */
        PyObject_SelfIter,              /* tp_iter */
@@ -553,7 +605,7 @@ static PyTypeObject tee_type = {
        0,                              /* tp_init */
        0,                              /* tp_alloc */
        tee_new,                        /* tp_new */
-       PyObject_Del,                   /* tp_free */
+       PyObject_GC_Del,                /* tp_free */
 };
 
 static PyObject *