Section: New Results

Evaluation and optimal dimensioning of real-time systems

Code analyses and advanced visualization of software in real-time

Participants : Damien Bodenes, Pierre Caserta, Olivier Zendra.

Last years, strong developments for our instrumentation, tracer and analyzer, had been performed, allowing us to really enter the experimental phase and getting first interesting results. A thorough state of the art had also been written.

This year, in 2011, this state of the art paper was finally published in TVCG, a leading journal in computer visualization [10] . Thanks to the experimental setup efforts of previous years, we were in 2011 able to conduct good experiments. We designed and implemented a new way to visualize relations between software elements These relations include static relations (is-a, direct heir, caller, callee, etc.) and dynamic ones (runtime caller, runtime callee). Our new relation visualization comprises a new way of placing way points so as to significantly decrease spatial and visual clutter when visualizing software systems with large numbers (thousands up to millions) of relations. This lead to a publication in VISSOFT, one of the most recognized conferences in the software visualization domain [23] , as well as a Best Poster in ECOOP, one of the most recognized conferences in the object-oriented domain [46] The important design and implementation work realized on the tracing and analysis software also lead to the publication of our method in ICOOOLPS 2011 [24]

Work is going onto analyze polymorphism in Java programs, answering an apparently simple yet so far unanswered question: how much polymorphism is there actually in Java programs. This is of paramount importance, since a lot of work occur around polymorphism, which is an important concept, but no one is currently able to tell how much it impact programs in real life. We have begun writing this paper in cooperation with the LIRMM lab in Montpellier. In addition, we are in the process of finishing work pertaining to analyzing program evolutions, looking at differences between versions, and analyzing how dynamic metrics and static metrics correlate to evolution rate.

Open Power and Energy Optimization PLatform and Estimator

Participants : Sophie Alexandre, Jonathan Ponroy, Kévin Roussel, Olivier Zendra.

Work in this domain was performed in the context of the ANR Open-PEOPLE (Open Power and Energy Optimization PLatform and Estimator) project, financed since the very end of 2008. INRIA Nancy Grand Est is responsible for the software part of the platform and is involved in memory management for low-power issues. Work in this project begun in April 2009 (kick-off meeting). We have finished setting up the very important infrastructure for the software part of the Open-PEOPLE platform. We have finished expressing the requirements for the platform, in order to start the actual developments and the actual integration of tools provided by the different partners. In 2011, we have finished expressing the platform architecture and user interface (GUI). We have also finished implementing the part of the software platform that is the remote control to the hardware platform. We finally have finished implementing the core of the software platform and canonical models handling. Several technical reports were written in relation to this work [38] , [39] , [40] , [42] , [43] , [44] .

We are now in the process of finishing the design and implementation of the PCMD (Power Consumption Model Development) and the PCAO (Power Consumption Analysis and Optimization) parts of the software platform, as well as the external tools integration work. The very first release of the whole Open-PEOPE platform is expected early 2012. This lead to the several presentations and posters in conferences [51] , [47] , [52] .

Robustness evaluation for a critical distributed system

Participants : Adrien Guénard, Lionel Havet, Françoise Simonot-Lion.

Wireless Sensor and Actuator Networks (WSANs) combine sensors and actuators interconnected by wireless networks in order to perform distributed sensing and acting tasks. Closed-loop controllers can therefore be deployed on WSANs; such systems have to meet specific requirements in terms of performance, dependability, energy and cost which raises great challenges due to the unreliability of wireless communications. A way to ensure that a system meets the required properties is to model it and go through its analysis. Building a model requires both deep knowledge on the system as well as on the used framework. Therefore there is a need for frameworks well-suited to the targeted systems and to the properties to verify. We proposed an approach meeting these conditions and a simulation framework, Samovar, based on Matlab / Simulink, allowing the modeling of the network protocols (Mac and routing services) and the resources sharing policy thanks to the TrueTime toolbox. Several classes of components (application, nodes, networks and middleware) and a clear semantics for their composition are identified. Furthermore, the design of Samovar was also driven by the need to transfer easily software components model between the concrete systems and its simulated model. The modeling and simulation method as well as the Samovar framework were assessed on several case studies. This work is supported by INRIA through the ADT SAMOVAR.