Beyond the Threaded Programming Model on Real-Time Operating Systems

Authors Erling Rennemo Jellum , Shaokai Lin , Peter Donovan , Efsane Soyer , Fuzail Shakir , Torleiv Bryne , Milica Orlandic , Marten Lohstroh , Edward A. Lee

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Erling Rennemo Jellum
  • NTNU, Trondheim, Norway
Shaokai Lin
  • University of California at Berkeley, CA, USA
Peter Donovan
  • University of California at Berkeley, CA, USA
Efsane Soyer
  • University of California at Berkeley, CA, USA
Fuzail Shakir
  • University of California at Berkeley, CA, USA
Torleiv Bryne
  • NTNU, Trondheim, Norway
Milica Orlandic
  • NTNU, Trondheim, Norway
Marten Lohstroh
  • University of California at Berkeley, CA, USA
Edward A. Lee
  • University of California at Berkeley, CA, USA


We want to thank Matthew Chorlian, Arthur Deng, Abanob Bostouros and Christian Menard for their work on porting the Savina benchmark to the Lingua Franca C target, as well as Hannes Klein and Felix Wittwer for their work on the original port of the Savina benchmark to the Lingua Franca C++ target. We would also like to acknowledge Soroush Bateni and Alexander Schulz-Rosengarten for their work on the Lingua Franca C runtime.

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Erling Rennemo Jellum, Shaokai Lin, Peter Donovan, Efsane Soyer, Fuzail Shakir, Torleiv Bryne, Milica Orlandic, Marten Lohstroh, and Edward A. Lee. Beyond the Threaded Programming Model on Real-Time Operating Systems. In Fourth Workshop on Next Generation Real-Time Embedded Systems (NG-RES 2023). Open Access Series in Informatics (OASIcs), Volume 108, pp. 3:1-3:13, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


The use of a real-time operating system (RTOS) raises the abstraction level for embedded systems design when compared to traditional bare-metal programming, resulting in simpler and more reusable application code. Modern RTOSes for resource-constrained platforms, like Zephyr and FreeRTOS, also offer threading support, but this kind of shared memory concurrency is a poor fit for expressing the reactive and interactive behaviors that are common in embedded systems. To address this, alternative concurrency models like the actor model or communicating sequential processes have been proposed. While those alternatives enable reactive design patterns, they fail to deliver determinism and do not address timing. This makes it difficult to verify that implemented behavior is as intended and impossible to specify timing constraints in a portable way. This makes it hard to create reusable library components out of common embedded design patterns, forcing developers to keep reinventing the wheel for each application and each platform. In this paper, we introduce the embedded target of Lingua Franca (LF) as a means to move beyond the threaded programming model provided by RTOSes and improve the state of the art in embedded programming. LF is based on the reactor model of computation, which is reactive, deterministic, and timed, providing a means to express concurrency and timing in a platform-independent way. We compare the performance of LF versus threaded C code - both running on Zephyr - in terms of response time, timing precision, throughput, and memory footprint.

Subject Classification

ACM Subject Classification
  • Computer systems organization → Embedded software
  • Real time
  • concurrency
  • reactors
  • Lingua Franca
  • RTOS


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