Scheduling Offset-Free Systems Under FIFO Priority Protocol

Matheus Ladeira (1, 2) , Emmanuel Grolleau (1, 2) , Fabien Bonneval (3) , Gautier Hattenberger (3) , Yassine Ouhammou (1, 2) , Yuri Hérouard (1, 4)

1 LIAS [Poitiers] - Laboratoire d'informatique et d'automatique pour les systèmes
2 SETR - Systèmes Embarqués Temps Réel
3 ENAC - Ecole Nationale de l'Aviation Civile
4 IDD - Ingénierie des Données et des moDèles

On UAVs, telemetry messages are often sent following a FIFO schedule, and some messages, depending on the FIFO queue state may suffer long delays, and can even be lost if the FIFO queue is full. Considering the high complexity of the problem of assigning offsets to periodic tasks, we propose a new heuristic, called GCD+, that we compare to the methods of the state of the art, showing that GCD+ significantly outperforms them on synthetic tasks sets. Then we use a real UAV use case, based on Paparazzi autopilot, to show that GCD+ behaves well. The proposed algorithm is meant to be the new Paparazzi's automatic offset assignment method for messages.

Mots clés: 2012 ACM Subject Classification Computer systems organization → Real-time system architecture; non-preemptible; heuristics; FIFO; autopilot

Domaines: Systèmes embarqués; Robotique [cs.RO]; Automatique / Robotique

Matheus Ladeira, Emmanuel Grolleau, Fabien Bonneval, Gautier Hattenberger, Yassine Ouhammou, et al.. Scheduling Offset-Free Systems Under FIFO Priority Protocol. 34th Euromicro Conference on Real-Time Systems (ECRTS 2022), Jul 2022, Modena, Italy. ⟨10.4230/DARTS.8.1.4⟩. ⟨hal-03716151⟩