Bounded delay timing analysis of a class of CSP programs with choice

Abstract

We extend our technique for determining exact time separation of events in systems with just concurrency to a restricted but still useful class of systems with both choice and concurrency. Such a system is described using a CSP program (including Martin's probe operator) with the restrictions that the communication behavior is data-independent, that there is no OR-causality, and that guard selection is either completely free or mutually exclusive. Such a CSP program is transformed into a safe Petri net. Interval time delays are specified on the places of the net. The timing analysis we perform is, for all possible timed executions of the system, determine the extreme separations in time for all occurrences of specified events. We formally define this problem, propose an algorithm for its solution, and apply the algorithm to an example program.