Make.1-A
Event channels handlers.
val program_start : event
represents an event which 'fired' when the program started
next 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