diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c index a879ef6c2d0..9c8125d1bf0 100644 --- a/Modules/gcmodule.c +++ b/Modules/gcmodule.c @@ -677,6 +677,53 @@ gc_get_thresh(PyObject *self, PyObject *args) return Py_BuildValue("(iii)", threshold0, threshold1, threshold2); } +struct referents{ + PyObject *objs; + int seen; +}; + +static int +referentsvisit(PyObject* obj, struct referents* refs) +{ + if (PySequence_Contains (refs->objs, obj)) { + refs->seen = 1; + return 1; + } + return 0; +} + +static void +gc_referents_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist) +{ + PyGC_Head *gc; + PyObject *obj; + traverseproc traverse; + struct referents refs = {objs, 0}; + for (gc = list->gc_next; gc != list; gc = gc->gc_next){ + obj = PyObject_FROM_GC(gc); + traverse = obj->ob_type->tp_traverse; + if (obj == objs || obj == resultlist) + continue; + if (traverse(obj, (visitproc)referentsvisit, &refs)) { + PyList_Append(resultlist, obj); + refs.seen = 0; + } + } +} + +static char gc_get_referents__doc__[]= +"get_referents(*objs) -> list\n\ +Return the list of objects that directly refer to any of objs."; + +static PyObject* +gc_get_referents(PyObject *self, PyObject* args) +{ + PyObject *result = PyList_New(0); + gc_referents_for(args, &generation0, result); + gc_referents_for(args, &generation1, result); + gc_referents_for(args, &generation2, result); + return result; +} static char gc__doc__ [] = "This module provides access to the garbage collector for reference cycles.\n" @@ -689,6 +736,7 @@ static char gc__doc__ [] = "get_debug() -- Get debugging flags.\n" "set_threshold() -- Set the collection thresholds.\n" "get_threshold() -- Return the current the collection thresholds.\n" +"get_referents() -- Return the list of objects that refer to an object.\n" ; static PyMethodDef GcMethods[] = { @@ -700,6 +748,8 @@ static PyMethodDef GcMethods[] = { {"set_threshold", gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__}, {"get_threshold", gc_get_thresh, METH_VARARGS, gc_get_thresh__doc__}, {"collect", gc_collect, METH_VARARGS, gc_collect__doc__}, + {"get_referents", gc_get_referents, METH_VARARGS, + gc_get_referents__doc__}, {NULL, NULL} /* Sentinel */ };