Title: A Conservative Extension of Synchronous Data-flow with State Machines
Speaker: Marc Pouzet

Slides: .pdf

Abstract:
In this talk, we present an extension of a synchronous data-flow language such as Scade/Lustre with imperative features expressed in terms of powerful state machine. This extension is fully conservative in the sense that all the programs from the basic language still make sense in the extended language and their semantics is preserved.

From a syntactical point of view this extension consists in hierarchical state machines that may carry at each hierarchy level a bunch of equations. This proposition is an alternative to the joint use of Simulink and Stateflow but improves it by allowing a fine grain mix of both styles.

The central idea is to base this extension on the use of clocks, translating imperative constructs into well clocked data-flow programs from the basic language. This clock directed approach is an easy way to define a semantics for the extension, it is light to implement in an existing compiler and experiments show that the generated code compete favorably with ad-hoc techniques. The proposed extension has been implemented in the Reluc compiler of Scade/Lustre developped at Esterel-Technologies and in the Lucid Synchrone compiler.