Advertisement

Pre-Scheduling: Integrating Offline and Online Scheduling Techniques

  • Weirong Wang
  • Aloysius K. Mok
  • Gerhard Fohler
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2855)

Abstract

The issue of integrating event-driven workload into existing static schedules has been addressed by Fohler’s Slot Shifting method [5] [6]. Slot Shifting takes a static schedule for a time-driven workload as input, analyzes its slacks off-line, and makes use of the slacks to accommodate an event-driven workload on-line. The Slot Shifting method does not address how to produce a static schedule which it assumes as given. We propose an integrated approach with an off-line pre-scheduler and an on-line scheduler. The pre-scheduler produces a pre-schedule of the time-driven workload with sufficient embedded slacks to accommodate the event-driven workload. The on-line scheduler schedules all workloads by EDF with one extra constraint: the order of execution of the time-driven workload must follow the pre-schedule. Our pre-scheduler produces a valid pre-schedule if and only if one exists and is therefore optimal. We shall show that the choice of the pre-schedule cannot be considered independent of the event-driven workload.

Keywords

Execution Time Ready Time Early Deadline First Periodic Task Sporadic Task 
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.
    Baker, T.P., Shaw, A.: The cyclic executive model and Ada. Proceedings of IEEE Real-Time Systems Symposium, December 1988, pp.120–129 (1988)Google Scholar
  2. 2.
    Dantzig, G.B.: Linear Programming and Extensions. Princeton University Press, Princeton (1963)zbMATHGoogle Scholar
  3. 3.
    Deng, Z., Liu, J.: Scheduling Real-Time Applications in an Open Environment. In: Real-Time Systems Symposium, December 1997, pp. 308–319 (1997)Google Scholar
  4. 4.
    Erschler, J., Fontan, F., Merce, C., Roubellat, F.: A New Dominance Concept in Scheduling Jobs on a Single Machine with Ready Times and Due Dates. Operations Research 31, 114–127Google Scholar
  5. 5.
    Fohler, G.: Joint Scheduling of Distributed Complex Periodic and Hard Aperiodic Tasks in Statically Scheduled Systems. In: Real-Time Systems Symposium, December 1995, pp. 152– 161 (1995)Google Scholar
  6. 6.
    Isovic, D., Fohler, G.: Handling Sporadic Tasks in Off-line Scheduled Distributed Real-Time Systems. In: The 11th EUROMICRO Conference on Real-Time Systems, York, England, July 1999, pp. 60–67 (1999)Google Scholar
  7. 7.
    Gerber, R., Pugh, W., Saksena, M.: Parametric Dispatching of Hard Real-Time Tasks. IEEE Trans. on Computers 44(3), 471–479 (1995)zbMATHCrossRefGoogle Scholar
  8. 8.
    Liu, C.L., Layland, J.W.: Scheduling Algorithms for Multi-programming in Hard Real-time Environment. Journal of ACM 20(1) (1973)Google Scholar
  9. 9.
    Mok, A.K.: Fundamental Design Problems of Distributed Systems for the Hard- Real-Time Environment. Ph.D. thesis. MIT (1983)Google Scholar
  10. 10.
    Mok, A.K., Feng, X.: Towards Compositionality in Real-Time Resource Partitioning Based on Regularity Bounds. In: Real-Time Systems Symposium, pp. 129–138 (2001)Google Scholar
  11. 11.
    Regehr, J., Stankovic, J.A.: HLS: A Framework for Composing Soft Real-Time Schedulers. In: Real-Time Systems Symposium, pp. 3–14 (2001)Google Scholar
  12. 12.
    Tsou, D.-C.: Execution Environment for Real-Time Rule-Based Decision Systems. PhD thesis, Department of Computer Sciences, The University of Texas at Austin (1997); esting for Real-Time Tasks, Real-Time Systems, vol. 11, No. 1, pp. 19–39 (1996)Google Scholar
  13. 13.
    Wang, W., Mok, A.K., Fohler, G.: Pre-Scheduling: Integrating Off-line and On-line Scheduling Techniques, http://www.cs.utexas.edu/users/mok/RTS/pubs.html
  14. 14.
    Yuan, X., Saksena, M.C., Agrawala, A.K.: A Decomposition Approach to Non- Preemptive Real-Time Scheduling. Real-Time Systems 6(1), 7–35 (1994)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • Weirong Wang
    • 1
  • Aloysius K. Mok
    • 1
  • Gerhard Fohler
    • 2
  1. 1.Department of Computer SciencesUniversity of Texas at AustinAustin
  2. 2.Department of Computer EngineeringMalardalen UniversitySweden

Personalised recommendations