Parallel Programming and Complexity Analysis using Actors

We describe Actors, a exible, scalable and eÆcient model of computation, and develop a framework for analyzing the parallel complexity of programs written in it. Actors are asynchronous, autonomous objects which interact by message-passing. The data and process decomposition inherent in Actors simpli es modeling realworld systems. High-level concurrent programming abstractions have been developed to simplify program development using actors; such abstractions do not compromise an eÆcient and portable implementation. In this paper, we de ne a parallel complexity model for actors. The model we develop gives an accurate measure of performance on realistic architectures. We illustrate its use by analyzing a number of examples.