Real-Time Scheduling and Analysis of Processing Chains on Multi-threaded Executor in ROS 2

• Published in: 2022 IEEE Real-Time Systems Symposium (RTSS 2022) pp. 27 - 39
• Main Authors: Jiang, Xu, Ji, Dong, Guan, Nan, Li, Ruoxiang, Tang, Yue, Wang, Yi
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2022
• Series: Real-Time Systems Symposium-Proceedings
• Subjects: Analytical models; Behavioral sciences; Operating systems; Real-time systems; Software; Time factors; Timing
• ISBN: 9781665453462; 1665453478; 9781665453479; 166545346X
• ISSN: 2576-3172
• DOI: 10.1109/RTSS55097.2022.00013

ROS (Robot Operating System) is currently one of the most popular development frameworks for robotic software, which is usually subject to hard real-time constraints in safe-critical domains. Designers must formally model and analyze its timing behaviors to guarantee that real-time constraints are always honored at run-time. This paper studies real-time scheduling and analysis under a multi-threaded executor in ROS 2. We present a formal description of the scheduling model of multi-threaded executors, and develop response time analysis techniques for processing chains executing on it. Moreover, we identify a risk of increasing the response time of chains that may be caused by improper design when deploying systems on multi-threaded executors, which provides a useful guidance to designers. We conduct experiments with both randomly generated workloads and case studies on a realistic ROS 2 platform to evaluate and demonstrate our results.