Um Simulador Distribuído Baseado No Paradigma De Eventos Condicionais

of Thesis presented to COPPE as partia1 fulfillment of the requirements for the degree of Master of Science (M.Sc.) A Distributed S i d a t o r Based on the Coiiditional Event Paradigm Luis Carlos Alves Pereira Quintela December 1992 Thesis Supervisor : Valmir Carneiro Barbosa Department: Programa de Engenharia de Sistemas e Computação Tlie attempt to study the behavior of complex real systems ailalytically comes up against the uarrow limits of representation models that can be mathematically treated. The computational s i d a t i o n of such systerns, through the use of prograins which implement representative models, appeass as a viable study alternative. The ernergence of parde l computer architectures, particularly distributed architectures, stiinulates the simulation field by allowing, as it offers computer capacity boosts, the analysis of even more cornplex systems. Nevertlieless, tlie use of parallelism briugs some problems which did not exist in sequential niachines. If the guarantee of respect to causality relationships among events was before trivially managed, simulatiou paradigms must be created in order to avoid the occurrence of causal errors when the simulation progresses concurrently in distributed spaces. Tliis work describes tlie implernentation of the conditonal event approach to distributed simulation conservative paradigm, elaborated by I<. M. Chandy and R. Shermaii. A simulator, based in such paradigm, is presented which allows the construction of logical systems for the simulation of real systems whicli can be represented by a specific inodel. Concerning this simulator, performance measures were taken through the simulation of a queuing network with parametric topology. A hypercubic transputer network and the parallel laiiguage Occam 2 were used iii the implementation.