Dag consistent parallel simulation: a predictable and robust conservative algorithm

We present a novel approach to parallel discrete event simulation based on the Cilk model of multithreaded computation. Cilk's runtime system not only manages the low-level aspects of program execution, but also provides the user with an algorithmic model of performance which can be used to predict the execution time of a parallel simulation. Moreover, a Cilk application can "scale down" to run on a single processor with nearly the same performance as that of serial code. A conservative parallel discrete event simulation algorithm has been developed in which communication between logical processes is achieved using Cilk's virtual memory model, dag consistent shared memory. The simulation executes in cycles, where each cycle involves a divide and conquer computation. Although local lookahead information can be exploited, the algorithm is robust in that it also calculates a global simulation time for each cycle. It can therefore be used for applications where zero lookahead may occur.