Real time clocks versus virtual clocks

Symmetric distributed termination algorithms are systematically developed. Solution are first presented in an abstract setting of Dijkstra, Feijen and Van Gasteren [DFG] and then gradually transformed into solutions to the distributed termination problem of Francez [F]. The initially used global real time clock is eventually replaced by local virtual clocks. A dependence between the degree of clock synchronization and the efficiency of the solutions is indicated.