Couple of comments.

git-svn-id: svn://localhost/ardour2/branches/3.0@6851 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/gtkmm2ext/gtk_ui.cc

@@ -369,6 +369,10 @@ UI::idle_add (int (*func)(void *), void *arg)
 
 /* END abstract_ui interfaces */
 
+/** Create a PBD::EventLoop::InvalidationRecord and attach a callback
+ *  to a given sigc::trackable so that PBD::EventLoop::invalidate_request
+ *  is called when that trackable is destroyed.
+ */
 PBD::EventLoop::InvalidationRecord*
 __invalidator (sigc::trackable& trackable, const char* file, int line)
 {

libs/pbd/event_loop.cc

@@ -20,6 +20,9 @@ EventLoop::set_event_loop_for_thread (EventLoop* loop)
 	thread_event_loop.set (loop, do_not_delete_the_loop_pointer); 
 }
 
+/** Called when a sigc::trackable that was connected to using the invalidator() macro
+ *  is destroyed.
+ */
 void* 
 EventLoop::invalidate_request (void* data)
 {