Task automata: Schedulability, decidability and undecidability

We present a model, task automata, for real time systems with non-uniformly recurring computation tasks. It is an extended version of timed automata with asynchronous processes that are computation tasks generated (or triggered) by timed events. Compared with classical task models for real time systems, task automata may be used to describe tasks (1) that are generated non-deterministically according to timing constraints in timed automata, (2) that may have interval execution times representing the best case and the worst case execution times, and (3) whose completion times may influence the releases of task instances. We generalize the classical notion of schedulability to task automata. A task automaton is schedulable if there exists a scheduling strategy such that all possible sequences of events generated by the automaton are schedulable in the sense that all associated tasks can be computed within their deadlines. Our first technical result is that the schedulability for a giv...

• Type: Journal
• Year: 2007
• Where: IANDC
• Authors: Elena Fersman, Pavel Krcál, Paul Pettersson, Wang Yi
• Keywords: Execution Times, IANDC 2007, Real Time Systems, Task Automata