Compositional schedulability analysis of real-time actor-based systems
Résumé
We present an extension of the actor model with real-time, including deadlines
associated with messages, and explicit application-level scheduling policies, e.g.,“earliest
deadline first” which can be associated with individual actors. Schedulability analysis in this
setting amounts to checking whether, given a scheduling policy for each actor, every task is
processed within its designated deadline. To check schedulability, we introduce a compositional
automata-theoretic approach, based on maximal use of model checking combined
with testing. Behavioral interfaces definewhat an actor expects from the environment, and the
deadlines for messages given these assumptions.We use model checking to verify that actors
match their behavioral interfaces. We extend timed automata refinement with the notion of
deadlines and use it to define compatibility of actor environments with the behavioral interfaces.
Model checking of compatibility is computationally hard, so we propose a special
testing process. We show that the analyses are decidable and automate the process using the
Uppaal model checker.