第十三章共享存储系统编程

第十三章共享存储系统编程内容摘要：

pthread_mutex_lock(amp。 slot_lock nslots++。 cond_signal(amp。 slots)。 pthread_mutex_unlock(amp。 slot_lock)。 } return NULL。 } 国家高性能计算中心（合肥） 共享存储系统编程  ANSI X3H5共享存储模型  POSIX 线程模型  OpenMP模型 国家高性能计算中心（合肥）  The History of OpenMP  What is directive/pragma?  Directivebased general purpose parallel programming API with emphasis on the ability to parallelize existing serial programs  Why a new standard?  Who’s Involved?  Parallelism model and basic directives  Fortran77, Fortran90  C, C++ OpenMP标准 国家高性能计算中心（合肥） The History of OpenMP  A key intermediate step was X3H5 in the late 80’s.  An official standards effort to agree on a parallel dialect of Fortran for shared memory puters.  The X3H5 effort failed. It was too big and too late.  OpenMP is born:  In 1996 a group formed to create an industry standard set of directives for SMP programming  This group called itself the OpenMP Architecture Review Board(the ARB) who takes care of OpenMP 国家高性能计算中心（合肥） The History of OpenMP(cont.)  The ARB has released the following specifications:  OpenMP for Fortran, Nov. 1997  OpenMP for C/C++, Nov. 1998  OpenMP Fortran Interpretations, Spring 1999  OpenMP (soon)  OpenMP is an evolving standard. Send ments over the feedback link on the OpenMP web site( 国家高性能计算中心（合肥） 为什么要建立新标准 ?  ANSI X3H5, 1994  时机不好 , 分布式机器流行  只支持循环级并行性，粒度太细  Pthreads(IEEE Posix )  是为低端 (low end)的共享机器 (如 SMP)的标准  对 FORTRAN的支持不够  适合任务并行 , 而不适合数据并行  MPI 消息传递的编程标准 , 对程序员要求高  HPF 主要用于 分布式存储机器  大量已有的科学应用程序需要很好地被继承和移植 国家高性能计算中心（合肥） In a Nutshell  A set of directives(library routines, and environment variables) used to annotate a sequential program to indicate how it should be executed in parallel— 继承 X3H5的许多概念  Portable, Simple and Scalable Shared Memory Multiprocessing API  not a new language  not automatic parallelization  extend base languages: Fortran77, Fortran90, C and C++  Multivendor Support, for both UNIX and NT  Standardizes Fine Grained(Loop) Parallelism, also Supports Coarse Grained Algorithms 国家高性能计算中心（合肥） OpenMP是什么。  一组编译制导语句和可调用的运行 (runtime)库函数 , 扩充到基本语言中用来表达程序中的并行性。