Defining New Non-preemptive Dispatching and Locking Policies for Ada

  • Alan Burns
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2043)


In many high-integrity applications, non-preemptive execution is preferred. This paper motivates and defines such a dispatching policy for Ada. It also describes an associated locking policy for protected objects. To deliver non-preemptive execution a new processing resource is introduced – the execution token. In addition to defining these new policies the paper also reviews how non-preemptive tasking systems can be analysed for their schedulability.


Priority Task Preemptive Schedule High Priority Task Protected Object Ready Queue 
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  1. 1.
    A. Burns. Non-preemptive dispatching and locking policies. In M.G. Harbour, editor, Proceedings of the 10th International Real-Time Ada Workshop. ACM Ada Letters, 2001.Google Scholar
  2. 2.
    L. Asplund, B. Johnson, and K. Lundqvist. Session summary: The Ravenscar pro_le and implementation issues. In A. Burns, editor, Proceedings of the 9th International Real-Time Ada Workshop, volume XIX(2), pages 12–14. ACM Ada Letters, June 1999.Google Scholar
  3. 3.
    N. C. Audsley, A. Burns, M. Richardson, K. Tindell, and A. J. Wellings. Applying new scheduling theory to static priority pre-emptive scheduling. Software Engineering Journal, 8(5):284–292, 1993.CrossRefGoogle Scholar
  4. 4.
    T. Baker and T. Vardanega. Session summary: Tasking profiles. In A.J. Wellings, editor, Proceedings of the 8th International Real-Time Ada Workshop, pages 5–7. ACM Ada Letters, 1997.Google Scholar
  5. 5.
    A. Burns and A.J. Welling. Restricted tasking models. In A.J. Wellings, editor, Proceedings of the 8th International Real-Time Ada Workshop, pages 27–32. ACM Ada Letters, 1997.Google Scholar
  6. 6.
    A. Burns and A. J. Wellings. Real-Time Systems and Programming Languages. Addison Wesley Longman, 3rd edition, 2001.Google Scholar
  7. 7.
    M. Joseph and P. Pandya. Finding response times in a real-time system. BCS Computer Journal, 29(5):390–395, 1986.CrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Alan Burns
    • 1
  1. 1.Real-Time Systems Research Group Department of Computer ScienceUniversity of YorkUK

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