Make traceback objects collectable.

This should eliminate the traceback returned by sys.exc_info() as a
common source of memory leaks.

diff --git a/Python/traceback.c b/Python/traceback.c
index 539483d585b8b4fcf38b5b207b5066d94b920848..7bbf852cdc72e8c5143d9ac27ee022b093ed0cc5 100644 (file)
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -36,12 +36,36 @@ static void
 tb_dealloc(tracebackobject *tb)
 {
        Py_TRASHCAN_SAFE_BEGIN(tb)
+       _PyObject_GC_UNTRACK(tb);
        Py_XDECREF(tb->tb_next);
        Py_XDECREF(tb->tb_frame);
-       PyObject_DEL(tb);
+       PyObject_GC_Del(tb);
        Py_TRASHCAN_SAFE_END(tb)
 }
 
+static int
+tb_traverse(tracebackobject *tb, visitproc visit, void *arg)
+{
+       int err = 0;
+       if (tb->tb_next) {
+               err = visit((PyObject *)tb->tb_next, arg);
+               if (err)
+                       return err;
+       }
+       if (tb->tb_frame) 
+               err = visit((PyObject *)tb->tb_frame, arg);
+       return err;
+}
+
+static void
+tb_clear(tracebackobject *tb)
+{
+       Py_XDECREF(tb->tb_next);
+       Py_XDECREF(tb->tb_frame);
+       tb->tb_next = NULL;
+       tb->tb_frame = NULL;
+}
+
 PyTypeObject PyTraceBack_Type = {
        PyObject_HEAD_INIT(&PyType_Type)
        0,
@@ -57,6 +81,25 @@ PyTypeObject PyTraceBack_Type = {
        0,              /*tp_as_number*/
        0,              /*tp_as_sequence*/
        0,              /*tp_as_mapping*/
+       0,              /* tp_hash */
+       0,              /* tp_call */
+       0,              /* tp_str */
+       0,              /* tp_getattro */
+       0,              /* tp_setattro */
+       0,                                      /* tp_as_buffer */
+       Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+       0,                                      /* tp_doc */
+       (traverseproc)tb_traverse,              /* tp_traverse */
+       (inquiry)tb_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 */
 };
 
 static tracebackobject *
@@ -69,7 +112,7 @@ newtracebackobject(tracebackobject *next, PyFrameObject *frame, int lasti,
                PyErr_BadInternalCall();
                return NULL;
        }
-       tb = PyObject_NEW(tracebackobject, &PyTraceBack_Type);
+       tb = PyObject_GC_New(tracebackobject, &PyTraceBack_Type);
        if (tb != NULL) {
                Py_XINCREF(next);
                tb->tb_next = next;
@@ -77,6 +120,7 @@ newtracebackobject(tracebackobject *next, PyFrameObject *frame, int lasti,
                tb->tb_frame = frame;
                tb->tb_lasti = lasti;
                tb->tb_lineno = lineno;
+               _PyObject_GC_TRACK(tb);
        }
        return tb;
 }