Constructing object-oriented distributed simulations

An object-oriented method for the design and implementation of distributed, discrete-event simulations is presented. Two differing synchronization mechanisms, conservative and optimistic, are identified. These differing mechanisms give rise to significant differences in the resulting simulation models. Which kind of synchronization allows more flexibility in modeling and implementing application programs is discussed. The authors present three simulation problems: the game of life (J.H. Conway, 1970), a sequential circuit with feedback (A.D. Friedman et al., 1975) and a queueing network. They show that each problem can be naturally decomposed into communicating subsystems. They present the Simula code for an object representation of the key subsystem in each problem. The conservative and the optimistic synchronization strategies for each problem are also compared