kernel: handle: implement handle_table_destroy()

kernel/handle.c

@@ -12,7 +12,7 @@
 #define RESERVED_HANDLES 64
 
 static struct vm_cache handle_table_cache = {
-	.c_name = "handle_table",
+	.c_name = "handle-table",
 	.c_obj_size = sizeof(struct handle_table),
 };
 
@@ -33,8 +33,48 @@ struct handle_table *handle_table_create(void)
 	return out;
 }
 
+static void do_handle_table_destroy_leaf(struct handle_table *tab)
+{
+	while (1) {
+		unsigned int index = bitmap_lowest_set(
+			tab->t_handles.t_handle_map,
+			HANDLES_PER_TABLE);
+		if (index == BITMAP_NPOS) {
+			break;
+		}
+
+		struct handle *child = &tab->t_handles.t_handle_list[index];
+		bitmap_clear(tab->t_subtables.t_subtable_map, index);
+		if (child->h_object) {
+			object_remove_handle(child->h_object);
+			child->h_object = NULL;
+		}
+	}
+}
+
+static void do_handle_table_destroy(
+	struct handle_table *tab,
+	unsigned int depth)
+{
+	if (depth == MAX_TABLE_DEPTH - 1) {
+		do_handle_table_destroy_leaf(tab);
+		return;
+	}
+
+	for (size_t i = 0; i < REFS_PER_TABLE; i++) {
+		struct handle_table *child
+			= tab->t_subtables.t_subtable_list[i];
+		if (child) {
+			do_handle_table_destroy(child, depth + 1);
+		}
+	}
+
+	vm_cache_free(&handle_table_cache, tab);
+}
+
 void handle_table_destroy(struct handle_table *tab)
 {
+	do_handle_table_destroy(tab, 0);
 }
 
 static kern_status_t decode_handle_indices(