Non-Simultaneity as a Design Constraint

Authors Jean Guyomarc'h , François Guerret, Bilal El Mejjati, Emmanuel Ohayon, Bastien Vincke, Alain Mérigot

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Author Details

Jean Guyomarc'h
  • Krono-Safe, Massy, France
  • Université Paris-Saclay, CNRS, Systèmes et Applications des Technologies de l'Information et de l'Energie, Orsay, France
François Guerret
  • Krono-Safe, Massy, France
Bilal El Mejjati
  • Krono-Safe, Massy, France
Emmanuel Ohayon
  • Krono-Safe, Massy, France
Bastien Vincke
  • Université Paris-Saclay, CNRS, Systèmes et Applications des Technologies de l'Information et de l'Energie, Orsay, France
Alain Mérigot
  • Université Paris-Saclay, CNRS, Systèmes et Applications des Technologies de l'Information et de l'Energie, Orsay, France


We would like to thank Fabien Siron, Matthieu Texier for their interesting and constructive discussions and other engineers from Krono-Safe who helped contributing to this paper. We would also like to thank the anonymous reviewers for their feedback and suggestions.

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Jean Guyomarc'h, François Guerret, Bilal El Mejjati, Emmanuel Ohayon, Bastien Vincke, and Alain Mérigot. Non-Simultaneity as a Design Constraint. In 27th International Symposium on Temporal Representation and Reasoning (TIME 2020). Leibniz International Proceedings in Informatics (LIPIcs), Volume 178, pp. 13:1-13:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Whether one or multiple hardware execution units are activated (i.e. CPU cores), invalid resource sharing, notably due to simultaneous accesses, proves to be problematic as it can yield to unexpected runtime behaviors with negative implications such as security or safety issues. The growing interest for off-the-shelf multi-core architectures in sensitive applications motivates the need for safe resources sharing. If critical sections are a well-known solution from imperative and non-temporized programming models, they fail to provide safety guarantees. By leveraging the time-triggered programming model, this paper aims at enforcing that identified critical windows of computations can never be simultaneously executed. We achieve this result by determining, before an application is compiled, the exact dates during which a task accesses a shared resource, which enables the off-line validation of non-simultaneity constraints.

Subject Classification

ACM Subject Classification
  • Theory of computation → Models of computation
  • Temporal reasoning
  • Temporal constraints
  • Specification and verification of systems


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