- Add DEBUG_SAVEALL option. When enabled all garbage objects found by the
collector will be saved in gc.garbage. This is useful for debugging a
program that creates reference cycles.
- Fix else statements in gcmodule.c to conform to Python coding standards.
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 06f51ed..62bc58e 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -53,10 +53,12 @@
#define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */
#define DEBUG_INSTANCES (1<<3) /* print instances */
#define DEBUG_OBJECTS (1<<4) /* print other objects */
+#define DEBUG_SAVEALL (1<<5) /* save all garbage in gc.garbage */
#define DEBUG_LEAK DEBUG_COLLECTABLE | \
DEBUG_UNCOLLECTABLE | \
DEBUG_INSTANCES | \
- DEBUG_OBJECTS
+ DEBUG_OBJECTS | \
+ DEBUG_SAVEALL
static int debug;
/* list of uncollectable objects */
@@ -100,7 +102,8 @@
if (from->gc_next == from) {
/* empty from list */
gc_list_init(to);
- } else {
+ }
+ else {
to->gc_next = from->gc_next;
to->gc_next->gc_prev = to;
to->gc_prev = from->gc_prev;
@@ -290,7 +293,8 @@
{
if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) {
debug_instance(msg, (PyInstanceObject *)op);
- } else if (debug & DEBUG_OBJECTS) {
+ }
+ else if (debug & DEBUG_OBJECTS) {
PySys_WriteStderr("gc: %.100s <%.100s %p>\n",
msg, op->ob_type->tp_name, op);
}
@@ -307,19 +311,20 @@
for (gc = finalizers->gc_next; gc != finalizers;
gc = finalizers->gc_next) {
PyObject *op = PyObject_FROM_GC(gc);
- /* Add all instances to a Python accessible list of garbage */
- if (PyInstance_Check(op)) {
+ if ((debug & DEBUG_SAVEALL) || PyInstance_Check(op)) {
+ /* If SAVEALL is not set then just append
+ * instances to the list of garbage. We assume
+ * that all objects in the finalizers list are
+ * reachable from instances. */
PyList_Append(garbage, op);
}
- /* We assume that all objects in finalizers are reachable from
- * instances. Once we add the instances to the garbage list
- * everything is reachable from Python again. */
+ /* object is now reachable again */
gc_list_remove(gc);
gc_list_append(gc, old);
}
}
-/* Break reference cycles by clearing the containers involved. This is
+/* Break reference cycles by clearing the containers involved. This is
* tricky business as the lists can be changing and we don't know which
* objects may be freed. It is possible I screwed something up here. */
static void
@@ -330,17 +335,18 @@
while (unreachable->gc_next != unreachable) {
PyGC_Head *gc = unreachable->gc_next;
PyObject *op = PyObject_FROM_GC(gc);
- /*
- PyList_Append(garbage, op);
- */
- if ((clear = op->ob_type->tp_clear) != NULL) {
- Py_INCREF(op);
- clear((PyObject *)op);
- Py_DECREF(op);
+ if (debug & DEBUG_SAVEALL) {
+ PyList_Append(garbage, op);
}
- /* only try to call tp_clear once for each object */
+ else {
+ if ((clear = op->ob_type->tp_clear) != NULL) {
+ Py_INCREF(op);
+ clear((PyObject *)op);
+ Py_DECREF(op);
+ }
+ }
if (unreachable->gc_next == gc) {
- /* still alive, move it, it may die later */
+ /* object is still alive, move it, it may die later */
gc_list_remove(gc);
gc_list_append(gc, old);
}
@@ -425,7 +431,8 @@
if (debug & DEBUG_STATS) {
if (m == 0 && n == 0) {
PySys_WriteStderr("gc: done.\n");
- } else {
+ }
+ else {
PySys_WriteStderr(
"gc: done, %ld unreachable, %ld uncollectable.\n",
n+m, n);
@@ -438,6 +445,9 @@
handle_finalizers(&finalizers, old);
if (PyErr_Occurred()) {
+ if (gc_str == NULL) {
+ gc_str = PyString_FromString("garbage collection");
+ }
PyErr_WriteUnraisable(gc_str);
Py_FatalError("unexpected exception during garbage collection");
}
@@ -461,7 +471,8 @@
n = collect(&generation2, &generation2);
}
collections1 = 0;
- } else if (collections0 > threshold1) {
+ }
+ else if (collections0 > threshold1) {
generation = 1;
collections1++;
gc_list_merge(&generation0, &generation1);
@@ -469,7 +480,8 @@
n = collect(&generation1, &generation2);
}
collections0 = 0;
- } else {
+ }
+ else {
generation = 0;
collections0++;
if (generation0.gc_next != &generation0) {
@@ -603,6 +615,7 @@
" DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n"
" DEBUG_INSTANCES - Print instance objects.\n"
" DEBUG_OBJECTS - Print objects other than instances.\n"
+" DEBUG_SAVEALL - Save objects to gc.garbage rather than freeing them.\n"
" DEBUG_LEAK - Debug leaking programs (everything but STATS).\n"
;
@@ -679,14 +692,14 @@
;
static PyMethodDef GcMethods[] = {
- {"enable", gc_enable, METH_VARARGS, gc_enable__doc__},
- {"disable", gc_disable, METH_VARARGS, gc_disable__doc__},
+ {"enable", gc_enable, METH_VARARGS, gc_enable__doc__},
+ {"disable", gc_disable, METH_VARARGS, gc_disable__doc__},
{"isenabled", gc_isenabled, METH_VARARGS, gc_isenabled__doc__},
{"set_debug", gc_set_debug, METH_VARARGS, gc_set_debug__doc__},
{"get_debug", gc_get_debug, METH_VARARGS, gc_get_debug__doc__},
{"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__},
+ {"collect", gc_collect, METH_VARARGS, gc_collect__doc__},
{NULL, NULL} /* Sentinel */
};
@@ -705,9 +718,6 @@
if (garbage == NULL) {
garbage = PyList_New(0);
}
- if (gc_str == NULL) {
- gc_str = PyString_FromString("garbage collection");
- }
PyDict_SetItemString(d, "garbage", garbage);
PyDict_SetItemString(d, "DEBUG_STATS",
PyInt_FromLong(DEBUG_STATS));
@@ -719,6 +729,8 @@
PyInt_FromLong(DEBUG_INSTANCES));
PyDict_SetItemString(d, "DEBUG_OBJECTS",
PyInt_FromLong(DEBUG_OBJECTS));
+ PyDict_SetItemString(d, "DEBUG_SAVEALL",
+ PyInt_FromLong(DEBUG_SAVEALL));
PyDict_SetItemString(d, "DEBUG_LEAK",
PyInt_FromLong(DEBUG_LEAK));
}