Add get_referrents() helper function.

diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index c0c091e228028679f399daff6900421a81fd4e0c..fc834f2cf5e63b2e4f04d55933ca4343cc280ef2 100644 (file)
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -828,6 +828,34 @@ gc_get_referrers(PyObject *self, PyObject *args)
        return result;
 }
 
+static int
+referrentsvisit(PyObject *obj, PyObject *list)
+{
+       if (PyList_Append(list, obj) < 0)
+               return 1;
+       return 0;
+}
+
+PyDoc_STRVAR(gc_get_referrents__doc__,
+"get_referrents(*objs) -> list\n\
+Return the list of objects that directly refer to any of objs.");
+
+static PyObject *
+gc_get_referrents(PyObject *self, PyObject *args)
+{
+       int i;
+       PyObject *result = PyList_New(0);
+       for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
+               PyObject *obj = PyTuple_GET_ITEM(args, i); 
+               traverseproc traverse = obj->ob_type->tp_traverse;
+               if (!traverse)
+                       continue;
+               if (traverse(obj, (visitproc)referrentsvisit, result))
+                       return NULL;
+       }
+       return result;
+}
+
 PyDoc_STRVAR(gc_get_objects__doc__,
 "get_objects() -> [...]\n"
 "\n"
@@ -884,7 +912,8 @@ PyDoc_STRVAR(gc__doc__,
 "set_threshold() -- Set the collection thresholds.\n"
 "get_threshold() -- Return the current the collection thresholds.\n"
 "get_objects() -- Return a list of all objects tracked by the collector.\n"
-"get_referrers() -- Return the list of objects that refer to an object.\n");
+"get_referrers() -- Return the list of objects that refer to an object.\n"
+"get_referrents() -- Return the list of objects that an object refers to.\n");
 
 static PyMethodDef GcMethods[] = {
        {"enable",         gc_enable,     METH_VARARGS, gc_enable__doc__},
@@ -898,6 +927,8 @@ static PyMethodDef GcMethods[] = {
        {"get_objects",    gc_get_objects,METH_VARARGS, gc_get_objects__doc__},
        {"get_referrers",  gc_get_referrers, METH_VARARGS,
                gc_get_referrers__doc__},
+       {"get_referrents",  gc_get_referrents, METH_VARARGS,
+               gc_get_referrents__doc__},
        {NULL,  NULL}           /* Sentinel */
 };