Advertisement

The Ceiling Protocol in Multi-moded Real-Time Systems1

  • Jorge Real
  • Andy Wellings
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1622)

Abstract

Fixed-priority scheduling has become a very important approach for implementing real-time systems. Two key aspects of the method are its support for resource management using priority inheritance protocols and its ability to model modes of operation. In this paper, we discuss the impact of mode changes on the immediate inheritance priority ceiling protocol. We show that the approach adopted in Ada can result in an increased blocking time for tasks that can unnecessarily jeopardise their schedulability. We propose several solutions to help solve this problem.

Keywords

Operating Mode Mode Change Priority Assignment Sporadic Task Schedulability Analysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    C.L. Liu and J.W. Layland. Scheduling algorithms for multiprogramming in a hard realtime environment. Journal of the ACM 20(1), pp 46–61. 1973.zbMATHCrossRefMathSciNetGoogle Scholar
  2. 2.
    L. Sha, R. Rajkumar and J.P. Lehoczky. Priority inheritance protocols: an approach to realtime synchronisation. Technical report CMU-CS-87-181. Computer Science Department, Carnegie-Mellon University. Pittsburgh, Pennsylvania. 1987.Google Scholar
  3. 3.
    R. Rajkumar, L. Sha and J.P. Lehoczky. An experimental investigation of synchronisation protocols. Proceedings of the 6th IEEE Workshop on Real-Time Operating Systems and Software, pp. 11–17. May, 1989.Google Scholar
  4. 4.
    Information Technology — Programming Languages Ada 95. International standard ISO/IEC 8652:1995. (Ada Reference Manual). 1995.Google Scholar
  5. 5.
    Information technology — Portable Operating System Interface (POSIX®) ISO/IEC 9945-1:1996(E) ANSI/IEEE Std 1003.1, 1996 Edition.Google Scholar
  6. 6.
    K.W. Tindell, A. Burns and A.J. Wellings. Mode changes in priority pre-emptively scheduled systems. Proceedings of the Real Time Systems Symposium, Phoenix, Arizona. 1992.Google Scholar
  7. 7.
    Private comments from Offer Pazy and Ted Baker.Google Scholar
  8. 8.
    L. Sha, R. Rajkumar, J.P. Lehoczky and R. Ramamritham. Mode change protocols for priority-driven preemptive scheduling. The Journal of Real-Time Systems, 1, 243–264. 1989.CrossRefGoogle Scholar
  9. 9.
    J. Real, A. Espinosa and A. Crespo. Using Ada 95 for prototyping real-time systems. In A. Strohmeier (Ed.) Reliable Software Technologies. Proceedings of the Ada-Europe’96 Conference. Lecture Notes in Computer Science vol. 1088, pp. 262–274. Springer Verlag.CrossRefGoogle Scholar
  10. 10.
    C.D. Locke, D.R. Vogel and T.J. Mesler. Building a predictable avionics platform in Ada: a case study. Proc. of the IEEE 12th Real Time Systems Symposium. Dec 1991.Google Scholar
  11. 11.
    N. Audsley, A. Burns, M. Richardson, K. Tindell, A.J. Wellings. Applying new scheduling theory to static priority pre-emptive scheduling. Software Engineering Journal. 8(5) pp. 284–292. 1993.CrossRefGoogle Scholar
  12. 12.
    P. Pedro and A. Burns. Schedulability Analysis for Mode Changes in Flexible Real-Time Systems. Proceedings 10th Euromicro Workshop on Real-Time Systems. Berlin, June 1998.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Jorge Real
    • 1
  • Andy Wellings
    • 2
  1. 1.Dept. de Informática de Sistemas y ComputadoresUniversidad Politécnica de ValenciaSpain
  2. 2.Department of Computer ScienceUniversity of YorkUK

Personalised recommendations