Asynchronous Testing of Synchronous Components in GALS Systems

International audienceGALS (Globally Asynchronous Locally Synchronous) systems, such as the Internet of Things or autonomous cars, integrate reactive synchronous components that interact asynchronously. The complexity induced by combining synchronous and asynchronous aspects makes GALS systems difficult to develop and debug. Ensuring their functional correctness and reliability requires rigorous design methodologies, based on formal methods and assisted by validation tools. In this paper we propose a testing methodology for GALS systems integrating: (1) synchronous and asynchronous concurrent models; (2) functional unit testing and behavioral conformance testing; and (3) various formal methods and their tool equipments. We leverage the conformance test generation for asynchronous systems to automatically derive realistic scenarios (input constraints and oracle), which are necessary ingredients for the unit testing of individual synchronous components, and are difficult and error-prone to design manually. We illustrate our approach on a simple, but relevant example inspired by autonomous cars

Loosely Time-Triggered Architectures: Improvements and Comparisons

International audienceLoosely Time-Triggered Architectures (LTTAs) are a proposal for constructing distributed embedded control systems. They build on the quasi-periodic architecture, where computing units execute 'almost periodically', by adding a thin layer of middleware that facilitates the implementation of synchronous applications.In this paper, we show how the deployment of a synchronous application on a quasi-periodic architecture can be modeled using a synchronous formalism. Then we detail two protocols, Back-Pressure LTTA, reminiscent of elastic circuits, and Time-Based LTTA, based on waiting. Compared to previous work, we present controller models that can be compiled for execution and a simplified version of the Time-Based protocol. We also compare the LTTA approach with architectures based on clock synchronization