Synthesis of Impartial Deadlock - free Programs for Concurrent Systems

This paper provides an algorithm for parallel program synthesi s. We study the particular but frequent case of sequential processes cooperation via shared resources. Given such a set of these processes (which may be non deterministic ones) , the algorithm outputs a parallel progra m which ensures safeness, liveness and fairness. The algorithm is divided in three parts: first it computes f or each process some sets of unavoidable local states, thus if possible it selects one of these sets for each pro cess-the selected sets must fulfill some constraints o f consistency-at last it builds the program by adding new cond itions on the local evolution of each process. The advantages of this algorithm are numerous: there is no cen tralized mechanism, the communication is organized through a virtual ring, and at last the algorithm is inc remental (i.e. some parts of the algorithm do not need to be computed again if another process is added). This work has been done while J. Ezpeleta was a researche r at the laboratory MASI under grant of the "Programa Nacional de becas de folmacion de Personal investi gador en el Extranjero" of the "Ministerio de Educacion y Ciencia" of Spain.It was partially supported b y the DEMON Esprit Basic Research Action 3148 and the PRONTIC-O358/89