- Overview, p1
- Real-Time, p2
- Execution Environment, p3
Real-Time
The behavior layer of BIP is extended to timed automata (and timed Petri nets). We consider discrete time semantics for clocks and urgency types (i.e. lazy, delayable, or eager [1]) for transitions. Our methodology relies on two models of the application [2]:
- The abstract model is defined without considering a specific execution platform. It provides timing constraints for transitions that are only user requirements, and it considers instantaneous interactions execution.
- Given execution times for interactions, the abstract model is modified into a corresponding physical model such as to take into account platform characteristics. A physical model is time-safe (i.e. deadlines are met) if its execution traces are included in the execution traces of the abstract model. It is time-robust if reducing the execution times preserves this property.
We implemented a Real-Time BIP Execution Engine that performs the real-time execution of BIP programs on a target platform, that is, execution times are obtained from the actual execution of the interactions on the platform, using a real-time clock of the target platform. It also checks for time-safety violation during the execution when time-robustness cannot be guaranteed for worst-case execution times.