A Runtime Implementation of OpenMP Tasks

Many task-based programming models have been developed and refined in recent years to support application development for shared memory platforms. Asynchronous tasks are a powerful programming abstraction that offer flexibility in conjunction with great expressivity. Research involving standardized tasking models like OpenMP and nonstandardized models like Cilk facilitate improvements in many tasking implementations. While the asynchronous task is arguably a fundamental element of parallel programming, it is the implementation, not the concept, that makes all the difference with respect to the performance that is obtained by a program that is parallelized using tasks. There are many approaches to implementing tasking constructs, but few have also given attention to providing the user with some capabilities for fine tuning the execution of their code. This paper provides an overview of one OpenMP implementation, highlights its main features, discusses the implementation, and demonstrates its performance with user controlled runtime variables.