Expansion And Improvement Of The Berkeley Upc Runtime Library

UPC is a parallel extension of the C programming language which uses a Single Program Multi-Data (SPMD) model and provides programmers with a shared global address space. As a descendant of Split-C, AC, and PCP, UPC has two primary objectives: 1) to provide efficient access to the underlying machine, and 2) to establish a common syntax and semantics for explicitly parallel programming in C. The quest for high performance means that UPC tries to minimize the overhead involved in communication among cooperating threads.However, efficient implementation of UPC is dependent on the use of low-latency, low-overhead, high-bandwidth communication systems. Unfortunately today most low-level high-performance communication interfaces are machine specific, which is a serious impediment to compiler portability. Therefore, we choose Berkeley UPC as the research target, which uses the GASNet communication as the underlying support. GASNet is a language-independent, low-level communication layer that provides high-performance communication primitives that are network-independent and aimed at supporting parallel languages. Because GASNet is a portable, high-performance Communication system, UPC based the GASNet is one promising system for large-scale clusters. But currently GASNet is only a experimental system, it has some potential to be improved. After analysis of the GASNet communication system, we found some locations that need to be improved and we optimized it. The experiment indicates that the optimization result is much obvious.In addition, for the other functions that the runtime library required, it is talked about in the article.