Using Reflection for Flexibility and Extensibility in a Metacomputing Environment

We present system developers with a reflective model, the Reflective Graph and Event model (RGE), for building metacomputing applications, incorporating our design goals of flexibility, extensibility, reusability, and composability. The model uses graphs and events to specify computations and enables first-class program graphs as event handlers. We demonstrate the RGE model in several areas of interest to metacomputing using Legion as our experimental testbed. We unify the concepts of exceptions and events; by making exceptions a special case of events. Furthermore, using RGE, we demonstrate how to build generic, composable and reusable components that can be shared across development environments such as MPI, PVM, NetSolve, C++, and Fortran.