An Overview of the Opus Language and Runtime System

We have recently introduced a new language, called Opus, which provides a set of Fortran language extensions that Mlow for integrated support of task and data parMlelism. It also provides shared data abstractions (SDAs) as a method for communication and synchronization among these tasks. In this paper, we first provide a brief description of the language features and then focus on both the language-dependent and language-independent parts of the runtime system that support the language. The language-independent portion of the runtime system supports lightweight threads across multiple address spaces, and is built upon existing lightweight thread and communication systems. The lafiguage-dependent portion of the runtime system supports conditional invocation of SDA methods and distributed SDA argument handling. *This research supported by the National Aeronautics and Space Administration under NASA Contract No. NASA-19480, while the authors were in residence at ICASE, NASA Langley Research Center, Hampton, VA 2368].