Suspending OpenMP Tasks on Asynchronous Events: Extending the Taskwait Construct

International audienceMany-core and heterogeneous architectures now require programmers to compose multiple asynchronous programming model to fully exploit hardware capabilities. As a shared-memory parallel programming model, OpenMP has the responsibility of orchestrating the suspension and progression of asynchronous operations occurring on a compute node, such as MPI communications or CUDA/HIP streams. Yet, specifications only come with the task detach(event) API to suspend tasks until an asynchronous operation is completed, which presents a few drawbacks. In this paper, we introduce the design and implementation of an extension on the taskwait construct to suspend a task until an asynchronous event completion. It aims to reduce runtime costs induced by the current solution, and to provide a standard API to automate portable task suspension solutions. The results show twice less overheads compared to the existing task detach clause