Abstract
Earliest Deadline First (EDF) and Fixed Priority (FP) scheduling represent the two main dispatching policies within the research domain of real-time systems engineering. Both dispatching policies are now supported by Ada. In this paper the two approaches are combined to maximize the advantages of both schemes. From EDF comes efficiency, from FP predictability. A system model is presented in which a relatively small number of high-integrity tasks are scheduled by FP, with the rest of the tasks being handled via an EDF domain of lower priority. Two aspects of integration are covered in this paper. Firstly, Response-Time Analysis (for FP) and Processor-Demand Analysis (for EDF) are brought together to provide a single analysis framework. Secondly, the programming of systems which combine FP and EDF is addressed within the facilities provided by Ada 2005. Both partitioned and dynamic schemes are covered.
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References
Audsley, N.C., Burns, A., Richardson, M., Tindell, K., Wellings, A.J.: Applying new scheduling theory to static priority preemptive scheduling. Software Engineering Journal 8(5), 284–292 (1993)
Baker, T.P.: Stack-based scheduling of realtime processes. Real-Time Systems 3(1) (March 1991)
Baruah, S.K., Burns, A.: Sustainable schedulability analysis. In: IEEE Real-Time Systems Symposium (RTSS), pp. 159–168 (2006)
Baruah, S.K., Howell, R.R., Rosier, L.E.: Feasibility problems for recurring tasks on one processor. Theorectical Computer Science 118, 3–20 (1993)
Baruah, S.K., Mok, A.K., Rosier, L.E.: Preemptive scheduling of hard real-time sporadic tasks on one processor. In: IEEE Real-Time Systems Symposium (RTSS), pp. 182–190 (1990)
Baruah, S.K., Mok, A.K., Rosier, L.E.: Hybrid-priority scheduling of resource-sharing sporadic task systems. In: IEEE Real-Time Systems and Applications Symposium, RTAS (2008)
Bernat, G., Burns, A.: Combining (n m)-hard deadlines with dual priority scheduling. In: Proceedings 18th IEEE Real-Time Systems Symposium, pp. 46–57 (1997)
Bril, R.J., Verhaegh, W.F.J., Pol, E.-J.D.: Initial values for on-line response time calculations. In: Proceedings of the 15th Euromicro Conference on Real-Time Systems (ECRTS), pp. 13–22 (2003)
Brukardt, R. (ed.): Ada 2005 reference manual. Technical report, ISO (2006)
Burns, A., Wellings, A.J.: Concurrency and Real-Time Programming in Ada 2005. Cambridge University Press, Cambridge (2007)
Burns, A., Wellings, A.J.: Real-Time Systems and Programming Languages, 4th edn. Addison-Wesley Longman, Amsterdam (2009)
Buttazzo, G.: Rate monotonic vs. EDF: Judgement day. Real-Time Systems Journal 29(1), 5–26 (2005)
Davis, R.I., Wellings, A.J.: Dual priority scheduling. In: Proceedings 16th IEEE Real-Time Systems Symposium, pp. 100–109 (1995)
Davis, R.I., Zabos, A., Burns, A.: Efficient exact schedulability tests for fixed priority pre-emptive systems. IEEE Transaction on Computers 57(9), 1261–1276 (2008)
Harbour, M.G., Gutirrez, J.C.P.: Response time analysis for tasks scheduled under EDF within fixed priorities. In: IEEE Real-Time Systems Symposium (RTSS), pp. 200–209 (2003)
Joseph, M., Pandya, P.: Finding response times in a real-time system. BCS Computer Journal 29(5), 390–395 (1986)
Lehoczky, J.P., Sha, L., Strosnider, J.K.: Enhanced aperiodic responsiveness in a hard real-time environment. In: Proceedings 8th IEEE Real-Time Systems Symposium, pp. 261–270 (1987)
Leung, J.Y.T., Whitehead, J.: On the complexity of fixed-priority scheduling of periodic, real-time tasks. Performance Evaluation (Netherlands) 2(4), 237–250 (1982)
Liu, C.L., Layland, J.W.: Scheduling algorithms for multiprogramming in a hard real-time environment. JACM 20(1), 46–61 (1973)
Ripoll, I., Mok, A.K.: Improvement in feasibilty testing for real-time tasks. Journal of Real-Time Systems 11(1), 19–39 (1996)
Sprunt, B., Sha, L., Lehoczky, J.P.: Aperiodic task scheduling for hard real-time systems. Real-Time Systems 1, 27–69 (1989)
Spuri, M.: Analysis of deadline schedule real-time systems. Technical Report 2772, INRIA, France (1996)
Zhang, F., Burns, A.: Analysis of hierarchical EDF preemptive scheduling. In: IEEE Real-Time Systems Symposium (RTSS), pp. 423–435 (2007)
Zhang, F., Burns, A.: Schedulability analysis for real-time systems with EDF scheduling. Technical Report YCS 426, University of York (2008)
Zhang, F., Burns, A.: Schedulability analysis for real-time systems with EDF scheduling. IEEE Transaction on Computers (to appear) (2008)
Zuberi, K.M., Pillai, P., Shin, K.G., Emeralds, K.G.: A small memory real-time microkernel. In: ACM Symposium on Operating Systems Principles, pp. 277–291 (1999)
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Burns, A., Wellings, A.J., Zhang, F. (2009). Combining EDF and FP Scheduling: Analysis and Implementation in Ada 2005. In: Kordon, F., Kermarrec, Y. (eds) Reliable Software Technologies – Ada-Europe 2009. Ada-Europe 2009. Lecture Notes in Computer Science, vol 5570. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-01924-1_9
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DOI: https://doi.org/10.1007/978-3-642-01924-1_9
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