Section: New Results

Formal Modeling of Concurrent Implementations

Participant : Dumitru Potop Butucaru.

Concurrent programming is notoriously difficult, especially in constrained embedded contexts. Threads, in particular, are wildly non-deterministic as a model of computation, and difficult to analyze in the general case. Fortunately, it is often the case that multi-threaded, semaphore-synchronized embedded software implements high-level functional specifications written in a deterministic data-flow language such as Scade or (safe subsets of) Simulink. We claim that in this case the implementation process should build not just the multi-threaded C code, but (first and foremost) a richer model exposing the data-flow organization of the computations performed by the implementation. From this model, the C code is extracted through selective pretty-printing, while knowledge of the data-flow organization facilitates analysis.

This year, we have proposes a language for describing such implementation models that expose the data-flow behavior hiding under the form of a multi-threaded program. The language allows the representation of efficient implementations featuring pipelined scheduling and optimized memory allocation and synchronization. We showed applicability on a large-scale industrial avionics case study and on a commercial many-core [24].