A Graph-based Operational Semantics for a Machine Model with Actor-based Concurrency

This paper introduces an extension to an existing delegation-based machine model that offers support for multi- dimensional separation of concerns (MDSOC). More specifically, we add concurrency primitives based on the well- known actor model of computation and specify an operational semantics for this extended machine model using graph rewrite rules. Apart from being inherently suitable for dealing with parallelism, graph rewriting has the advantage of decent tool support, allowing for visual simulation. We validate our work by demonstrating a practical example in which the concurrency primitives are combined with existing MDSOC features.