libcgroup: Introduce post order walk

With the introduction of the flags, we now actually make use of them.
This patch adds a post mode and modifies the test case to also do a post
order walk.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Bharata B Rao <bharata@linux.vnet.ibm.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/walk_test.c b/tests/walk_test.c
index 2e16ecd..e09f705 100644
--- a/tests/walk_test.c
+++ b/tests/walk_test.c
@@ -41,6 +41,7 @@ int main(int argc, char *argv[])
 		exit(EXIT_FAILURE);
 	}
 	strcpy(root, info.full_path);
+	printf("Begin pre-order walk\n");
 	printf("root is %s\n", root);
 	visit_node(&info, root);
 	while ((ret = cgroup_walk_tree_next(0, &handle, &info, lvl)) !=
@@ -49,6 +50,32 @@ int main(int argc, char *argv[])
 	}
 	cgroup_walk_tree_end(&handle);
 
+	printf("pre-order walk finished\n");
+	ret = cgroup_walk_tree_begin(controller, "/", 0, &handle, &info, &lvl);
+
+	if (ret != 0) {
+		fprintf(stderr, "Walk failed\n");
+		exit(EXIT_FAILURE);
+	}
+
+	ret = cgroup_walk_tree_set_flags(&handle, CGROUP_WALK_TYPE_POST_DIR);
+
+	if (ret) {
+		fprintf(stderr, "Walk failed with %s\n", cgroup_strerror(ret));
+		exit(EXIT_FAILURE);
+	}
+
+	strcpy(root, info.full_path);
+	printf("Begin post-order walk\n");
+	printf("root is %s\n", root);
+	visit_node(&info, root);
+	while ((ret = cgroup_walk_tree_next(0, &handle, &info, lvl)) !=
+			ECGEOF) {
+		visit_node(&info, root);
+	}
+	cgroup_walk_tree_end(&handle);
+	printf("post order walk finished\n");
+
 	ret = cgroup_walk_tree_begin(controller, "/a", 2, &handle, &info, &lvl);
 
 	if (ret != 0) {