Efficient execution of nondeterministic parallel programs on asynchronous systems

We consider the problem of asynchronous execution of parallel programs. The original program is assumed to be designed for a synchronous system, while the actual system may be asynchronous. We seek an automatic execution scheme, which allows the asynchronous system to execute the synchronous program. Previous solutions to this problem provide a solution only for the case where the original program is deterministic. Here, we provide the first solution for the nondeterministic case (e.g. randomized programs). Our scheme is based on a novel agreement protocol for this setting. Our protocol allows n asynchronous processors to agree on n word-sized values in O(n log n log log n) total work. Total work is defined to be the summation of the number of steps performed by all processes (including busy waiting).