Section: New Software and Platforms

The Polychrony toolset

Participants : Loïc Besnard, Thierry Gautier, Jean-Pierre Talpin.

The Polychrony toolset is an Open Source development environment for critical/embedded systems. It is based on Signal, a real-time polychronous data-flow language. It provides a unified model-driven environment to perform design exploration by using top-down and bottom-up design methodologies formally supported by design model transformations from specification to implementation and from synchrony to asynchrony. It can be included in heterogeneous design systems with various input formalisms and output languages. The Polychrony tool-set provides a formal framework to: validate a design at different levels, by the way of formal verification and/or simulation; refine descriptions in a top-down approach; abstract properties needed for black-box composition; compose heterogeneous components (bottom-up with COTS); generate executable code for various architectures. The Polychrony tool-set contains three main components and an experimental interface to GNU Compiler Collection (GCC):

• The Signal toolbox, a batch compiler for the Signal language, and a structured API that provides a set of program transformations. Itcan be installed without other components and is distributed under GPL V2 license.

• The Signal GUI, a Graphical User Interface to the Signal toolbox (editor + interactive access to compiling functionalities). It can be used either as a specific tool or as a graphical view under Eclipse. In 2015, it has been transformed and restructured, in order to get a more up-to-date interface allowing multi-window manipulation of programs. It is distributed under GPL V2 license.

• The SSME platform, a front-end to the Signal toolbox in the Eclipse environment. It is distributed under EPL license.

Figure 3. The Polychrony toolset high-level architecture

As part of its open-source release, the Polychrony tool-set not only comprises source code libraries but also an important corpus of structured documentation, whose aim is not only to document each functionality and service, but also to help a potential developer to package a subset of these functionalities and services, and adapt them to developing a new application-specific tool: a new language front-end, a new back-end compiler. This multi-scale, multi-purpose documentation aims to provide different views of the software, from a high-level structural view to low-level descriptions of basic modules. It supports a distribution of the software “by apartment” (a functionality or a set of functionalities) intended for developers who would only be interested by part of the services of the tool-set. The Polychrony tool-set also provides a large library of Signal programs and examples, user documentations and developer-oriented implementation documents, and facilities to generate new versions. The Polychrony tool-set can be freely downloaded from http://polychrony.inria.fr/. This site, intended for users and for developers, contains executable and source versions of the software for different platforms, user documentation, examples, libraries, scientific publications and implementation documentation. In particular, this is the site for the open-source distribution of Polychrony. The Inria GForge https://gforge.inria.fr contains the whole source of the environment and its documentation. It is intended for developers.