Debugging and Verification Tools for Lingua Franca in Gemoc Studio

Abstract

LINGUA FRANCA (LF) is a polyglot coordination language designed for the composition of concurrent, timesensitive, and potentially distributed reactive components called reactors. The LF coordination layer facilitates the use of target languages (e.g., C, C++, Python, TypeScript) to realize the program logic, where each target language requires a separate runtime implementation that must correctly implement the reactor semantics. Verifying the correctness of runtime implementations is not a trivial task, and is currently done on the basis of regression testing. To provide a more formal verification tool for existing and future target runtimes, as well as to help verify properties of LF programs, we recruit the use of GEMOC Studio-an Eclipse-based workbench for the development, integration, and use of heterogeneous executable modeling languages. We present an operational model for LF, realized in GEMOC Studio, that is primed to interact with a rich set of analysis and verification tools. Our instrumentation provides the ability to navigate the execution of LF programs using an omniscient debugger with graphical model animation; to check assertions in particular execution runs, or exhaustively, using a model checker; and to validate or debug traces obtained from arbitrary LF runtime environments.

Pragmatics Twelve Years Later: A Report on Lingua Franca

“…We elaborate on this with several practical examples in Sect. 3. An important component of pragmatics is the choice of graphical syntax, including its amenability to automatic layout; case in point, we discuss some of our design choices for LF in Sect.…”

“…From the modelling perspective, this approach can be extended to include simulation, as in the GMOC debugging and simulation tool for LF [3] that feeds live data into the diagram, or visualizing intermediate steps in the compilation, such as dependencies determined by the compiler, e. g. as available in the KIELER tool for SCCharts [49]. With the support of the LSP and Visual Studio Code, the pragmatics-aware modeling support is also available in the latest IDEs (see Sect.…”

“…As an official project hosted at the Eclipse Foundation it has some visibility, leading to its adoption in quite a few downstream tools. Just recently, ELK has been adopted in the Graphical Language Server Platform (GLSP) 3 meta-framework for graphical modeling, which follows Microsoft's approach for a textual integrated development environment (IDE) with the language server protocol (LSP) 4 . It extends the LSP philosophy of having a clear separation between a backend for language and semantics and a frontend for GUI features to the domain of graphical modeling languages.…”

Language Design for Reactive Systems

“…Yet, CCSL not only provides patterns of classical synchronous clock constraints for multiclocking [GG10] or asynchronous clock relations [Lam78], but also real-time representations of physical time. For example, CCSL is used in a simulation and debugging tool for LF programs [DCB+21].…”

“…There are some initial efforts to combine multiclocked SCCharts with the CCSL by André [And09] to establish a formal specification for the relation of clocks [SHM+20]. CCSL was also used for the specification and validation of timing requirements in Esterel [AM09] and the simulation and debugging of LF programs [DCB+21]. Section 6.3.2 will discuss this topic in more detail.…”