[rygel] core: Allow owned refs to parent container

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 9efb735a3f86755004f9f189cd6846bd28b64aba
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Tue Jun 23 14:57:28 2009 +0300

    core: Allow owned refs to parent container

 src/rygel/rygel-media-object.vala |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/src/rygel/rygel-media-object.vala b/src/rygel/rygel-media-object.vala
index 719b9e1..2c37223 100644
--- a/src/rygel/rygel-media-object.vala
+++ b/src/rygel/rygel-media-object.vala
@@ -29,5 +29,14 @@ public abstract class Rygel.MediaObject : GLib.Object {
     public string id;
     public string title;
 
+    // You can keep both a unowned and owned ref to parent of this MediaObject.
+    // In most cases, one will only need to keep an unowned ref to avoid cyclic
+    // references since usually parent container will keep refs to child items.
+    // However in some cases, one only wants the parent to exist as long as the
+    // child exists and it is in those cases, you will want to use 'parent_ref'.
+    //
+    // You must set 'parent' if you set 'parent_ref' but the opposite is not
+    // mandatory.
     public unowned MediaContainer parent;
+    public MediaContainer parent_ref;
 }