Exploiting advanced task parallelism in high performance fortran via a task library

Abstract

As task parallelism has been proven to be useful for applications like real-time signal processing, branch and bound problems, and multidisciplinary applications, the new standard HPF 2.0 of the data parallel language High Performance Fortran (HPF) provides approved extensions for task parallelism that allow nested task and data parallelism. Unfortunately, these extensions allow the spawning of tasks but do not allow interaction like synchronization and communication between tasks during their execution and therefore might be too restrictive for certain application classes. E.g., they are not suitable for expressing the complex interactions among asynchronous tasks as required by multidis-ciplinary applications. They do not support any parallel programming style that is based on non-deterministic communication patterns. This paper discusses the extension of the task model provided by HPF 2.0 with a task library that allows interaction between tasks during their lifetime, mainly by message passing with an user-friendly HPF binding. The same library with the same interface can also be used for single processors in the local HPF model. The task model of HPF 2.0 and the task library have been implemented in the ADAPTOR HPF compilation system that is available in the public domain. Some experimental results show the easy use of the concepts and the efficiency of the chosen approach. © Springer-Verlag Berlin Heidelberg 1999.