Event channels handlers.
val program_start : eventrepresents an event which 'fired' when the program started
val after : Eventchn.t -> event -> event Lwt.tnext channel event blocks until the system receives an event newer than event on channel channel. If an event is received while we aren't looking then this will be remembered and the next call to after will immediately unblock. If the system is suspended and then resumed, all event channel bindings are invalidated and this function will fail with Generation.Invalid
val wait : Eventchn.t -> unit Lwt.twait evtchn is a cancellable thread that will wake up when evtchn is notified. Cancel it if you are no longer interested in waiting on evtchn. Note that if the notification is sent before wait is called then the notification is lost.
val run : Eventchn.handle -> unitrun () goes through the event mask and activate any events, potentially spawning new threads. This function is called by Main.run. Do not call it unless you know what you are doing.
resume needs to be called after the unikernel is resumed. However, this function is automatically called by Sched.suspend. Do NOT use it unless you know what you are doing.