Evaluating MSRP and MrsP with the Multiprocessor Ravenscar Profile

  • Jorge GarridoEmail author
  • Juan Zamorano
  • Alejandro Alonso
  • Juan A. de la Puente
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10300)


One of the main challenges of developing real-time systems with Ada on multiprocessor platforms is finding an appropriate scheduling policy and locking policy for shared objects. Some modifications of the standard Ceiling_Locking policy have been proposed for multiprocessor architectures, among which MSRP and MrsP have raised most interest. In this paper the possible uses of both policies in full Ada and Ravenscar programs are explored. To this purpose, classical response time analysis is extended in the paper to deal with heterogeneous access costs in multiprocessor systems. A case study has been used to validate the approach, and an extensive test bench for comparing MSRP and MrsP has been run in order to compare the schedulability properties of both methods. The conclusion is that, although MrsP provides a better overall performance, in many practical situations the simpler MSRP protocol provides comparable results when considering heterogeneous access costs, while being compatible with the Ravenscar restrictions.


Real-time systems Multiprocessor systems Ada Ravenscar profile Schedulability analysis 



The authors would like to acknowledge the fruitful discussion with Guillem Bernat who provided some initial ideas for the paper.

We would also like to acknowledge the helpful comments by anonymous reviewers, which have contributed to improve the quality of the paper.


  1. 1.
    ISO/IEC 8652:2012(E): Information Technology – Programming Languages – Ada (2012)Google Scholar
  2. 2.
    Audsley, N.C., Burns, A., Richardson, M., Tindell, K., Wellings, A.: Applying new scheduling theory to static priority preemptive scheduling. Softw. Eng. J. 8(5), 284–292 (1993)CrossRefGoogle Scholar
  3. 3.
    Brandenburg, B.B.: Scheduling and locking in multiprocessor real-time operating systems. Ph.D. thesis, The University of North Carolina at Chapel Hill (2011)Google Scholar
  4. 4.
    Burns, A., Wellings, A.J.: Locking policies for multiprocessor Ada. Ada Lett. 33(2), 59–65 (2013)CrossRefGoogle Scholar
  5. 5.
    Burns, A., Dobbing, B., Vardanega, T.: Guide for the use of the Ada Ravenscar profile in high integrity systems. Ada Lett. XXIV, 1–74 (2004)CrossRefGoogle Scholar
  6. 6.
    Burns, A., Wellings, A.J.: A schedulability compatible multiprocessor resource sharing protocol-MrsP. In: 2013 25th Euromicro Conference on Real-Time Systems (ECRTS), pp. 282–291. IEEE (2013)Google Scholar
  7. 7.
    Davis, R.I., Burns, A.: A survey of hard real-time scheduling algorithms and schedulability analysis techniques for multiprocessor systems. ACM Computing Surveys 43(4) (2011)Google Scholar
  8. 8.
    Dobbing, B., Burns, A.: The Ravenscar profile for high-integrity real-time programs. Ada Lett. XVII(6), 1–6 (1998). Proceedings of the ACM SIGAda International Conference – SIGAda 1998CrossRefGoogle Scholar
  9. 9.
    Gai, P., Lipari, G., Natale, M.D.: Minimizing memory utilization of real-time task sets in single and multi-processor systems-on-a-chip. In: Proceedings of the 22nd IEEE Real-Time Systems Symposium. IEEE Computer Society (2001)Google Scholar
  10. 10.
    Garrido, J., Lacruz, B., Zamorano, J., de la Puente, J.A.: In support of extending the Ravenscar profile. Ada Lett. 36(1), 63–67 (2016)CrossRefGoogle Scholar
  11. 11.
    Leung, J.Y.T., Whitehead, J.: On the complexity of fixed-priority scheduling of periodic real-time tasks. Perform. Eval. 2(4), 237–250 (1982)MathSciNetCrossRefzbMATHGoogle Scholar
  12. 12.
    Lin, S., Wellings, A.J., Burns, A.: Ada 2012: resource sharing and multiprocessors. Ada Lett. 33(1), 32–44 (2013)CrossRefGoogle Scholar
  13. 13.
    de la Puente, J.A., Zamorano, J., Alonso, A., Garrido, J., Salazar, E., de Miguel, M.A.: Experience in spacecraft on-board software development. Ada User J. 35(1), 55–60 (2014)Google Scholar
  14. 14.
    Rajkumar, R., Sha, L., Lehoczky, J.P.: Real-time synchronization protocols for multiprocessors. In: IEEE Real-Time Systems Symposium (1988)Google Scholar
  15. 15.
    Rajkumar, R.: Real-time synchronization protocols for shared memory multiprocessors. In: Proceedings of the 10th International Conference on Distributed Computing Systems, pp. 116–123. IEEE (1990)Google Scholar
  16. 16.
    Rajkumar, R.: Synchronization in Real-Time Systems: A priority Inheritance Approach. Kluwer Academic Publishers, Dordrecht (1991)CrossRefzbMATHGoogle Scholar
  17. 17.
    Zamorano, J., Garrido, J.: Schedulability analysis of PWM tasks for the UPMSat-2 ADCS. In: de la Puente, J.A., Vardanega, T. (eds.) Ada-Europe 2015. LNCS, vol. 9111, pp. 85–99. Springer, Cham (2015). doi: 10.1007/978-3-319-19584-1_6 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Jorge Garrido
    • 1
    Email author
  • Juan Zamorano
    • 1
  • Alejandro Alonso
    • 1
  • Juan A. de la Puente
    • 1
  1. 1.Sistemas de Tiempo Real e Ingeniería de Servicios Telemáticos (STRAST)Universidad Politécnica de Madrid (UPM)MadridSpain

Personalised recommendations