BasicProcessEvent

     NAME
	  basicprocessevent - Predefined events	generated by
	  ProcessManager

     DESCRIPTION
	  Events are the way external events are reported to
	  IOProcesses by the ProcessManager. There can also be user
	  defined events created and sent from IOProcess to IOProces.

     EXAMPLES
	  See the users	manual in simioprocess.ps

     AUTHOR
	  Boris	Magnusson, Lund	Institute of Technology.

     DETAILED INTERFACE
	  The Events are defined without attributes. It	should always
	  be clear from	the situation what the event indicates.	This
	  design choice	is consistent with the idea that IOProcess
	  should be rather small and do	one well-defined task. It is
	  thus not possible to have a IOPorcess	that waits for events
	  from two different external files, but one can have two
	  IOProcesses waiting for an external file each!.

     BasicProcessEvent
	     class BasicProcessEvent;
	  Abstract superclass of all Events, used  as  superclass  for
	  user defined events.

     ProcessEvent
	     BasicProcessEvent class ProcessEvent;
	  Abstract superclass of all Event classes  generated  by  the
	  Process Manager.

     InputEvent
	     ProcessEvent class	InputEvent;
	  Generated when an inimage (or	read) can safely be issued  on
	  the file for which EnableIOEvents has	been called.

     OutputEvent
	     ProcessEvent class	OutputEvent;
	  Generated when the output buffer is non-full and a write can
	  be  issued  on  the  file  for which EnableIOEvents has been
	  called.

     IOTimeoutEvent
	     ProcessEvent class	IOTimeoutEvent;
	  Generated  when  the	timeout	 period	 has  passed  with  no
	  InputEvent  generated. StartIOTimeout	must have been called.
	  A process will receive a IOTimeoutEvent or a InputEvent, but
	  never	both

     UpdateEvent
	     ProcessEvent class	UpdateEvent;
	  Generated when some other IOProcess have recieved some Event
	  and this process did not become active during	its processing

     PeriodicEvent
	     ProcessEvent class	PeriodicEvent;
	  Generated when the propper time interval has passed.

     CancelEvent
	     ProcessEvent class	CancelEvent;
	  Broadcasted to all IOProcess object that have	requested them
	  with a call to EnableCancelEvents. Events are	triggered by a
	  process calling the ProcessManager operation CancelAll.