test: cgroup: test moving to the root cg

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

tests/cgroup.rs

@@ -0,0 +1,29 @@
+//! Simple unit tests about the control groups system.
+extern crate cgroups;
+use cgroups::{Cgroup, CgroupPid};
+
+extern crate nix;
+extern crate libc;
+
+#[test]
+fn test_tasks_iterator() {
+    let hier = cgroups::hierarchies::V1::new();
+    let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
+    let cg = Cgroup::new(&hier, String::from("test_tasks_iterator"));
+    {
+        // Add a task to the control group.
+        cg.add_task(CgroupPid::from(pid));
+        let mut tasks = cg.tasks().into_iter();
+        // Verify that the task is indeed in the control group
+        assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(tasks.next(), None);
+        
+        // Now, try removing it.
+        cg.remove_task(CgroupPid::from(pid));
+        tasks = cg.tasks().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(tasks.next(), None);
+    }
+    cg.delete();
+}