Theoretical Computer Science
The algorithmic analysis of hybrid systems
Theoretical Computer Science - Special issue on hybrid systems
An algebraic framework for urgency
Information and Computation
On the Construction of Live Timed Systems
TACAS '00 Proceedings of the 6th International Conference on Tools and Algorithms for Construction and Analysis of Systems: Held as Part of the European Joint Conferences on the Theory and Practice of Software, ETAPS 2000
Almost ASAP semantics: from timed models to timed implementations
Formal Aspects of Computing
Modeling Heterogeneous Real-time Components in BIP
SEFM '06 Proceedings of the Fourth IEEE International Conference on Software Engineering and Formal Methods
Symbolic quality control for multimedia applications
Real-Time Systems
Dynamical properties of timed automata revisited
FORMATS'07 Proceedings of the 5th international conference on Formal modeling and analysis of timed systems
Implementation of timed automata: an issue of semantics or modeling?
FORMATS'05 Proceedings of the Third international conference on Formal Modeling and Analysis of Timed Systems
Static timing analysis for hard real-time systems
VMCAI'10 Proceedings of the 11th international conference on Verification, Model Checking, and Abstract Interpretation
Automated addition of fault recovery to cyber-physical component-based models
EMSOFT '11 Proceedings of the ninth ACM international conference on Embedded software
Synchronous interface theories and time triggered scheduling
FMOODS'12/FORTE'12 Proceedings of the 14th joint IFIP WG 6.1 international conference and Proceedings of the 32nd IFIP WG 6.1 international conference on Formal Techniques for Distributed Systems
Rigorous design of robot software: A formal component-based approach
Robotics and Autonomous Systems
A theory of fault recovery for component-based models
SSS'12 Proceedings of the 14th international conference on Stabilization, Safety, and Security of Distributed Systems
Model-Based implementation of parallel real-time systems
FASE'13 Proceedings of the 16th international conference on Fundamental Approaches to Software Engineering
Shrinktech: a tool for the robustness analysis of timed automata
CAV'13 Proceedings of the 25th international conference on Computer Aided Verification
Information and Computation
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Correct and efficient implementation of general real-time applications remains by far an open problem. A key issue is meeting timing constraints whose satisfaction depends on features of the execution platform, in particular its speed. Existing rigorous implementation techniques are applicable to specific classes of systems e.g. with periodic tasks, time deterministic systems. We present a general model-based implementation method for real-time systems based on the use of two models. An abstract model representing the behavior of real-time software as a timed automaton. The latter describes user-defined platform-independent timing constraints. Its transitions are timeless and correspond to the execution of statements of the real-time software. A physical model representing the behavior of the real-time software running on a given platform. It is obtained by assigning execution times to the transitions of the abstract model. A necessary condition for implementability is time-safety, that is, any (timed) execution sequence of the physical model is also an execution sequence of the abstract model. Time-safety simply means that the platform is fast enough to meet the timing requirements. As execution times of actions are not known exactly, time-safety is checked for worst-case execution times of actions by making an assumption of time-robustness: time-safety is preserved when speed of the execution platform increases. We show that as a rule, physical models are not time-robust and show that time-determinism is a sufficient condition for time-robustness. For given real-time software and execution platform corresponding to a time-robust model, we define an Execution Engine that coordinates the execution of the application software so as to meet its timing constraints. Furthermore, in case of non-robustness, the Execution Engine can detect violations of time-safety and stop execution. We have implemented the Execution Engine for BIP programs with real-time constraints. We have validated the implementation method for an adaptive MPEG video encoder. Experimental results reveal the existence of timing anomalies seriously degrading performance for increasing platform execution speed.