D. Jefferson
Abstract
This paper describes the Time Warp Operating System, under development for three years at the Jet Propulsion Laboratory for the Caltech Mark III Hypercube multi-processor. Its primary goal is concurrent execution of large, irregular discrete event simulations at maximum speed. It also supports any other distributed applications that are synchronized by virtual time.
The Time Warp Operating System includes a complete implementation of the Time Warp mechanism, and is a substantial departure from conventional operating systems in that it performs synchronization by a general distributed process rollback mechanism. The use of general rollback forces a rethinking of many aspects of operating system design, including programming interface, scheduling, message routing and queueing, storage management, flow control, and commitment.
In this paper we review the mechanics of Time Warp, describe the TWOS operating system, show how to construct simulations in object-oriented form to run under TWOS, and offer a qualitative comparison of Time Warp to the Chandy-Misra method of distributed simulation. We also include details of two benchmark simulations and preliminary measurements of time-to-completion, speedup, rollback rate, and antimessage rate, all as functions of the number of processors used.
- Berry 86 Berry, Orna, "Performance Evaluation of the Time Warp Distributed Simulation Mechanism'', Ph.D. Dissertation, Dept. of Computer Science, University of Southern California, May 1986 Google Scholar
Digital Library
- Chandy 81 Chandy, K.M., and Misra, Jayadev, "Asynchronous distributed simulation via a sequence of parallel computations", Communications of the ACM, Vol. 24, No. 4, April 1981 Google ScholarDigital Library
- Fox, 85 Fox, Geoffrey, "Use of the Caltech Hypercube", IEEE Software, Vol. 2, p. 73, July 1985Google Scholar
- Gafni 85 Gafni, Anat, "Space Management and Cancellation Mechanisms for Time Warp", Ph.D. Dissertation, Dept. of Computer Science, University of Southern California, TR-85-341, December 1985Google Scholar
- Jefferson 85 Jefferson, David, "Virtual Time", ACM Transactions on Programming Languages and Systems, Vol. 7, No. 3, July 1985 Google ScholarDigital Library
- Jefferson 82 Jefferson, David and Sowizral, Henry, "Fast Concurrent Simulation Using the Time Warp Mechanism, Part I: Local Control", Rand Note N-1906AF, the Rand Corporation, Santa Monica, California, Dec. 1982Google Scholar
- Joyce 87 Joyce, J., Lomow, G.A., Slind, K., Unger, B.W., "Monitoring Distributed Systems", ACM Transactions on Computer Systems, Vol. 5, No. 2, May 1987 Google ScholarDigital Library
- Lamport 78 Lamport, Leslie, "Time, clocks and the ordering of events in a distributed system", Communications of the ACM, Vol. 21, No. 7, July 1978 Google ScholarDigital Library
- Li 87 Li, X., Unger, B. W., "Languages for Distributed Simulation", Proceedings of the Conference on Simulation and AI, Simulation Series, Vol 18, No. 3, January 1987Google Scholar
- Misra 86 Misra, Jayadev, "Distributed Discrete Event Simulation", Computing Surveys, Vol 18, No. 1, March 1986 Google ScholarDigital Library
- Peterson 85 Peterson, J.C., J. Tuazon, D. Lieberman, M. PineI, "Caltech/JPL Hypercube Concurrent Processor'', Proceedings of 1985 International Conference on Parallel Processing, St. Charles, Ill., Aug. 1985Google Scholar
- Reynolds 82 Reynolds, Paul, "A Shared Resource Algorithm for Distributed Simulation", Proceedings of the 9th International Symposium on Computer Architecture, Austin, Texas, IEEE, New York Google ScholarDigital Library
- West 87 West, D., Lomow, G., Unger, B.W., "Optimizing Time Warp Using the Semantics of Abstract Data Types", Proceedings of the Conference on Simulation and AI ,Simulation Series, Vol 18, No. 3, January 1987Google Scholar
- Xiao 86 Xiao, Z., Unger, B.W., Cleary, J., Lomow, G., Li, X., Slind, K., "Jade Virtual Time Implementation Manual", Research Report No. 86/242/16, Dept. of Computer Science, University of Calgary, Calgary, AlbertaGoogle Scholar
Index Terms
- Time warp operating system
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