Parallel Exploration of Directed Acyclic Graphs using the Actor Model

In this paper we describe a generic scheme for the parallel exploration of directed acyclic graphs starting from one or more `roots' of the graph. Our scheme is designed for graphs with the following properties, (i) discovering neighbors at any node requires a non-trivial amount of computation, it is not a simple lookup; (ii) once a node is processed, all its neighbors are discovered; (iii) each node can be discovered through multiple paths, but should only be processed once. Several computational problems can be reduced to traversing such graphs, where the goal is to explore the graph and build a traversal roadmap. As a proof of concept for the effectiveness of our scheme at achieving speedup due to parallelism, we implement the scheme for the parallel exploration of assembly landscape using the EASAL methodology.