Handling of concurrent events

• Who defines the order of concurrent events?
  • often: a global event queue
  • in TBM: events are defined by blocks → order not well-defined
• Example testNullserver
  • 
  • leads to error message
  • undefined, what comes first at Set Attribute: new entity or new attribute value
• Solutions
  • ignore message → entities leave at the wrong port!
  • null server after Get Attribute → model works
• Old problem
  • BUFFER command of GPSS