Lawrence Berkeley National Laboratory, United States of America
UPC++ is a C++ library supporting Partitioned Global Address Space (PGAS) programming. The UPC++ API offers low-overhead one-sided Remote Memory Access (RMA) and Remote Procedure Calls (RPC), along with future/promise-based asynchrony to express dependencies between asynchronous computations and data movement. UPC++ supports simple, regular data structures as well as more elaborate distributed structures where communication is fine-grained, irregular, or both. UPC++'s support for aggressive asynchrony enables the application to overlap communication to reduce communication wait times, and the GASNet communication layer provides efficient low-overhead RMA/RPC on HPC networks.
This tutorial introduces basic concepts and advanced optimization techniques of UPC++. We discuss the UPC++ memory and execution models and examine basic algorithm implementations. Participants gain hands-on experience incorporating UPC++ features into several application examples. We also examine two irregular applications (metagenomic assembler and multifrontal sparse solver) and describe how they leverage UPC++ features to optimize communication performance.