Scenarios: A model of non-determinate computation
Many researchers have sought a semantic theory that extends the history function model of determinate networks to a history relation model of non-determinate networks. By demonstrating that history relations are a fundamentally incomplete characterization of non-determinate computation, we have shown that no such extension exists. This demonstration was accomplished by constructing two networks which, though indistinguishable by history relations, cannot be substituted for each other in a larger network without changing the history relation of the larger network.
A few alternative theories for non-determinate networks have been proposed. Unfortunately, these theories offer complicated semantic models revealing many details of network computation, far more than is often relevant for an interface specification. We have introduced a relatively simple network model, the set of scenarios. This model is a straightforward extension of history relations, for a scenario is merely an element of a history relation whose constituent values are partially ordered by a relation representing causality; but it can reveal subtle, though important, distinctions unseen in history relations.
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- Ackerman, W. B., "Data Flow Languages", Proceedings of the 1979 National Computer Conference, AFIPS Conference Proceedings 48, June 1979, 1087–1095.Google Scholar
- Arvind, K. P. Gostelow, and W. Plouffe, "Indeterminacy, Monitors and Dataflow", Proceedings of the Sixth ACM Symposium on Operating Systems Principles, Operating Systems Review 11, 5(November 1977), 159–169.Google Scholar
- Brock, J. D., Formal Properties of a Non-Determinate Data Flow Language, Ph. D. thesis, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, expected September 1981.Google Scholar
- Dennis, J. B., "A Language Design for Structured Concurrency", Design and Implementation of Programming Languages: Proceedings of a DoD Sponsored Workshop (J. H. Williams and D. A. Fisher, Eds.), Lecture Notes in Computer Science 54, October 1976, 231–242.Google Scholar
- Hewitt, C. E., and H. Baker, "Actors and Continuous Functionals," Formal Description of Programming Concepts, (E. J. Neuhold, Ed.), August 1977, 367–390.Google Scholar
- Kahn, G., "The Semantics of a Simple Language for Parallel Programming", Information Processing 74: Proceeding of the IFIP Congress 74 (J. L. Rosenfeld, Ed.), 1974, 471–475.Google Scholar
- Kahn, G., and D. MacQueen, "Coroutines and Networks of Parallel Processes", Information Processing 77: Proceedings of IFIP Congress 77 (B. Gilchrist, Ed.), August 1977, 993–998.Google Scholar
- Keller, R. M., "Denotational Models for Parallel Programs with Indeterminate Operators", Formal Description of Programming Concepts (E. J. Neuhold, Ed.), August 1977, North-Holland Publishing Company, New York, New York, 337–366.Google Scholar
- Kosinski, P. R., "A Straightforward Denotational Semantics for Non-Determinate Data Flow Programs", Conference Record of the Fifth ACM Symposium on Principles of Programming Languages, January 1978, 214–221.Google Scholar
- Leung, C. K. C., "ADL: An Architecture Description Language for Packet Communication Systems", Proceedings of the 4th International Symposium on Computer Hardware Description Languages, October 1979, 6–13.Google Scholar
- McGraw, J. R., "Data Flow Computing — Software Development", IEEE Transactions on Computers C-29, 12(December 1980), 1095–1103.Google Scholar
- Milne, G., and R. Milner, "Concurrent Processes and Their Syntax", Journal of the ACM 26, 2(April 1979), 302–321.Google Scholar
- Park, D., ”On the Semantics of Fair parallelism“, Abstract Software Specifications: 1979 Copenhagen Winter School Proceedings (D. Bjørner, Ed.), Lecture Notes in Computer Science 86, February 1979, 504–526.Google Scholar
- Pratt, V. R., comment in published discussion on "Denotational Models with Indeterminate Operators" by R.M. Kelier, Formal Description of Programming Concepts (E. J. Neuhold, Ed.), August 1977, North-Holland Publishing Company, New York, New York, 366.Google Scholar