Section: Scientific Foundations
Model-Driven Engineering for Real-time and Embedded systems
Participants : Charles André, Julien Deantoni, Frédéric Mallet, Marie-Agnès Peraldi-Frati, Robert de Simone, Yves Sorel.
In the embedded and real-time domain, the behavior of the system is a first-class concern that should enable validations and verifications. However, there are few tentatives to formally express the behavioral semantics of such models. Most of the time, Models bring the syntax while the related (application-specific) analysis tools bring their own behavioral semantics. This forbids a good interoperability between analysis tools and complexifies the understanding of a model behavioral semantics.
Lots of improvements are expected on the research field. To cite a few, the description of the semantics directly at the metamodel level is expected as well as a better definition of the link between the clock instants and the model events.
We promote a model-driven engineering approach for embedded system design based on formal semantics, models and methods. The range of models consists mainly of hierarchical state diagrams and dataflow/activity diagrams for behavior, and component diagrams with connection ports for compositional structure. This brought to light the idea of using the OMG UML formalisms for graphical representation of models, as it contains all these modeling views. We consider these kinds of models as purely syntactic.
In order to provide a formal and explicit behavioral semantics for such models, the idea developped this year was to use the notion of functional time as a first-class concern. Considering functional time makes it possible to specify events and relation between events of the model. While still based on the MARTE Time Model, the relation between the events of the model are now encapsulated in a semantic model.
The semantic model specifies constraints to be respected for the behavioral correctness of a model. It can be considered as the behavioral specification of the model in the same way than an OCL model specifies constraints to be respected for the static correctness of a model. The semantic model is expressed in CCSL and can be input to the TimeSquare prototype tool (Section 5.1 ), to simulate and animate the model according to its formal behavioral semantics.
Then common Models of Computation and Communication (MoCCs) can be built on top of these constructs, to be used directly by the final user. The advanced profile features are aimed primarily at advanced designers and semanticians willing to devise accurate time patterns.
Following the AAA (Algorithm-Architecture Adequation ) methodology [56] , MARTE promotes independent modeling of applications called algorithm and embedded platforms called architecture in a first step. The mapping (spatial and temporal) of applications onto embedded platforms is realized only in a subsequent step, through distributed and real-time scheduling analysis and optimizations, relative to the timing constraints and resource costs involved.
Marte was started as a joint action of Thales, CEA-List and INRIA in their CARROLL collaborative program. The profile RFP (Request For Proposals) was voted early 2005, the initial submission in June 2007, and the (first complete) revised version in middle 2008. After the Finalization Task Force phase (2008–2009), the UML profile MARTE was adopted in November 2009 [37] .
