[PostDoc] Exploiting High-Level Design Information in WCET Estimation

supervisors : Claire Maiza, Pascal Raymomd

Postdoctoral reasearcher (6 to 18 months, from 2012 October)

Scientific context :

The advertised position will be funded by the ANR/INS project W-SEPT.

Critical embedded systems are generally composed of repetitive tasks that must meet drastic timing constraints, such as termination deadlines. Providing an upper bound of the worst-case execution time (WCET) of such tasks at design time is thus necessary to prove the correctness of the system. Dynamic methods based on testing give realistic but unsafe results : they are not guaranteed to pinpoint the worst-case execution. On the contrary, static timing analysis methods, compute safe WCET upper bounds, but at the cost of a potentially large over-approximation. Sources of over-estimation stem from the analysis of the hardware platform, but also from the unfeasible executions due to the semantics of the program itself. Much effort has been devoted to model the hardware precisely. In comparison, handling semantic aspects in timing analysis has been less studied. It has been mainly limited to determining loop bounds and rather simple infeasible paths.

Discovering and exploiting semantic information is particularly hard because WCET techniques are working at the very low level of assembly or byte code, missing the fact that the code actually comes from higher-level design and programming methods. Clearly, the real source code is (at least) given in a general-purposed structured language like C. Moreover, and very often in critical domains, the source application was designed with an even more high-level framework like Scade, Simulink etc.

Objectives of the Post-Doc The purpose of this position is to study the opportunities arising from a high-level design on the WCET analysis. Typically, what are the relevant information that can be identified at the top-level, passed through the compilation process, and then exploited in order to enhance the WCET estimation ?

Terms of employment

A full-time position as a postdoctoral researcher for a period of 6 to 18 months starting as soon as possible. The position will be funded by the ANR/INS project W-SEPT. The salary will be 2500 EUR gross per month depending on qualifications and experience.

Application

Send a detailed CV, a list of publications, a list of referees (persons that can recommend you), and a short letter explaining your motivations for this position, by email to :

Claire.Maiza@imag.fr, Pascal.Raymond@imag.fr

Please include [POSTDOC W-SEPT] in the subject of your mail, and only attach PDF files.