(An) improved algorithm for protocol validation by extended circular exploration

Abstract

In this thesis, to improve the efficiency of state exploration and to solve (or relieve) the problem of state explosion, we propose another method of state exploration called the extended circular exploration (ECE), which does not need to explore all the reachable global states and can be applied to N-party protocol with alternative routes, i.e., it is applicable to the protocol in which adaptive routing mechanism can be performed. Using this ECE, we can eliminate the topology restriction of the CE through extending the notions of circular exploration. That is to say, in this thesis, we explore only those global states which are reachable, provided that the participant processes of any group of transitions proceed at the same speed, and that they can be formed as a cycle. The state space thus explored is not exhaustive. The algorithm presented can detect deadlock error and unspecified reception error. It requires stotage space and/or execution time much less than those of the CP but, a little more than those of Hwang``s technique. However the results of validation are more correct than those of Hwang``s with this generalized network topology. It can be viewed as a solution of the N-process collision and the interference mechanism [Rubi82].