[vala] Add bindings to GLib.Once

[Maciej Marcin Piechotka <mpiechotka src gnome org>]

commit f5a54052d1f7fb263bb8363934fabdc845f3a934
Author: Maciej Piechotka <uzytkownik2 gmail com>
Date:   Tue Apr 16 13:53:13 2013 +0200

    Add bindings to GLib.Once

 vapi/glib-2.0.vapi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
---
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index ab686c5..163ffbb 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -1813,7 +1813,18 @@ namespace GLib {
                public bool timed_wait (Mutex mutex, TimeVal abs_time);
                public bool wait_until (Mutex mutex, int64 end_time);
        }
-       
+
+       [CCode (cname = "GThreadFunc")]
+       public delegate G OnceFunc<G> ();
+
+       [CCode (default_value = "G_ONCE_INIT")]
+       public struct Once<G> {
+               [CCode (cname = "g_once")]
+               public unowned G once (OnceFunc<G> function);
+               public static bool init_enter ([CCode (ctype="volatile gsize *")] size_t *value);
+               public static void init_leave ([CCode (ctype="volatile gsize *")] size_t *value, size_t 
set_value);
+       }
+
        /* Thread Pools */
 
        [CCode (cname = "GFunc")]