Runtime系统综述

Runtime systems play an important role in parallel programming and parallel compilation. In this paper,goals and key techniques of runtime systems are presented. And some experiences and its trend are given in the end.     

并行程序设计语言发展现状

In this paper we introduce the history of the parallel programming language and list some of currently parallel programming languages. Then according to the classified principle. We analyze some of the representative parallel programming languages in detail. Finally, we show a further feature to the parallel programming language.     

Shared Variable Oriented Parallel Precompiler for SPMD Model

For the moment,commercial parallel computer systems with distributed memory architecture are usually provided with parallel FORTRAN or parallel C compliers,which are just traditional sequential FORTRAN or C compilers expanded with communication statements.Programmers suffer from writing parallel programs with communication statements. The Shared Variable Oriented Parallel Precompiler (SVOPP) proposed in this paper can automatically generate appropriate communication statements based on shared variables for SPMD(Single Program Multiple Data) computation model and greatly ease the parallel programming with high communication efficiency.The core function of parallel C precompiler has been successfully verified on a transputer-based parallel computer.Its prominent performance shows that SVOPP is probably a break-through in parallel programming technique.     

Parallel solution for finite element linear systems of equations on workstation cluster

With the advances in the high speed computers network technologies, a workstation cluster is becoming the main environment for parallel processing. Finite element linear systems of equations are common throughout structural analysis in Civil Engineering. The preconditioned conjugate gradient method （PCGM） is an iterative method used to solve the finite element systems of equations with symmetric positive definite system matrices. In this paper, the algorithm of PCGM is parallelized and implemented on DELL workstation cluster. Optimization techniques for the sparse matrix vector multiplication are adopted in programming. The storage scheme is analyzed in detail. The experiment result shows that the designed parallel algorithm has high speedup and good efficiency on the high performance workstation cluster. This illustrates the power of parallel computing in solving large problems much faster than on a single processor.     

DGLa: A Distributed Graphics Language

A distributed graphics programming language called DGLa is presented,which facilitates the development of distributed graphics application.Facilities for distributed programming and graphics support are included in it,It not only supports synchronous and asynchronous communication but also provides programmer with multiple control mechanism for process communication.The graphics support of DGLa is powerful,for both sequential graphics library and parallel graphics library are provided.The design consideration and implementation experience are discussed in detail in this paper.Application examples are also given.     

The Distributed Logical Reasoning Language D_Tuili and Its Implementation on Microcomputer Network

D－Tuili,having been implemented on microcompute network,is a distributed logical reasoning programming language.D-Tuili supports parallel programming on the language level,and couples loosely with the distributed database management system,so data in distributed databases can be used in the distributed logic programs.In this paper,we mainly introduce the components of D-Tuili used to design distributed logic programs.Furthermore,the main principles to implement D-Tuili and the main technologies adopted in the implemented system of D-Tuili are described.     

Approximate Dynamic Programming for Self-Learning Control

This paper introduces a self-learning control approach based on approximate dynamic programming. Dynamic programming was introduced by Bellman in the 1950’s for solving optimal control problems of nonlinear dynamical systems. Due to its high computational complexity, the applications of dynamic programming have been limited to simple and small problems. The key step in finding approximate solutions to dynamic programming is to estimate the performance index in dynamic programming. The optimal control signal can then be determined by minimizing (or maximizing) the performance index. Artificial neural networks are very efficient tools in representing the performance index in dynamic programming. This paper assumes the use of neural networks for estimating the performance index in dynamic programming and for generating optimal control signals, thus to achieve optimal control through self-learning.     

Parallel Error Detection for Leading Zero Anticipation

The algorithm and its implementation of the leading zero anticipation （LZA） are very vital for the performance of a high-speed floating-point adder in today＇s state of art microprocessor design. Unfortunately, in predicting ＂shift amount＂ by a conventional LZA design, the result could be off by one position. This paper presents a novel parallel error detection algorithm for a general-case LZA. The proposed approach enables parallel execution of conventional LZA and its error detection, so that the error-indicatlon signal can be generated earlier in the stage of normalization, thus reducing the critical path and improving overall performance. The circuit implementation of this algorithm also shows its advantages of area and power compared with other previous work.     

Lane of parallel through carry in ternary optical adder

At the present 50 to 100 microseconds are necessary for a liquid crystal to change its state from opacity to clarity; 1.14×10-5 microseconds are however proved to be enough for light to pass through a clarity liquid crystal device. Rooted from this great difference in time, an optical adder was constructed with parallel through carry lanes (PTCL) composed of liquid crystals. Because all carries in PTCL process in parallel, the carry delay in the ternary optical computer's adder is avoided. Eliminating the carry delay in adder of ternary optical computer by physical means, the PTCL is also applicable for other types of optical adders. Moreover a light diagram of the adder and one PTCL structure are provided.     

Evolution of MPP SoC architecture techniques

The evolution of chip architecture is discussed in this paper. Then MPP SoC architectures according to three kinds of computing paradigms are analyzed. Based on these discussions and analyses, array processor architecture for unified change is presented, which could implement the simplification, effectiveness and versatility of both data level and non-data level parallel algorithm＇s programming.     

HPMR在并行矩阵计算中的应用

为了解决传统并行编程难度大、效率低的问题,提出一种基于MapReduce模型的并行编程方法,在高性能MapReduce平台上实现矩阵并行LU分解。实验结果表明,相比传统并行编程模型,MapReduce模型并行程序可较好满足高性能数值计算需求,其编程简洁性和可读性能有效提升并行编程效率。     

COUPL+:并行PDE求解函数库

COUPL＋是一种基于消息传递模型的并行库,它将并行程序巾需要处理的数据划分、消息传递函数的调用等都封装在其函数中。COUPL＋可以简化在分布式存储结构并行机上编写基于网格的应用程序的任务。该文简要介绍了COUPL＋的基本原理,以及它与MPI、OpenMP和HPF的特性对比;并且使用COUPL＋实现了共轭梯度法和结构化网格计算两种并行计算中常用的任务,也对比了使用MPI和HPF的性能差异。     

并行程序设计模型和语言

并行计算技术的发展已有20多年的历史了.时至今日,高性能并行计算仍然缺乏有效的并行程序设计方法和工具,使得编写并行程序、理解并行程序的行为、调试和优化并行程序的性能都很困难.从分析并行程序设计困难的原因入手,指出了当前各种高性能并行机系统支持的并行程序设计方法存在的诸多问题,综述了并行程序设计模型和语言的研究现状,给出了并行程序设计模型的评价标准,并提出了这一研究领域所面临的挑战性问题,指出了一些未来可能的发展方向.     

多层次并行体绘制算法的研究与应用

三维数据场的体绘制技术是科学可视化中一个重要的研究方向,本文在研究和总结体绘制的发展历程与关键技术的基础之上,着重研究了体绘制中的光线投射算法,结合多核处理器机群系统,提出并实现了一种基于多层次并行编程模型的并行光线投射体绘制算法,并成功地将该算法应用于三维城市浅层地质模型,取得了良好的可视化效果。分别对MPI环境和多层次并行编程MPI+OpenMP环境下的光线投射算法进行了不同计算规模的性能比较实验。实验和分析表明,多层次并行光线投射体绘制算法加快了体绘制的速度,MPI+OpenMP多层次并行模型性能高于纯MPI编程模型的性能。     

Distributed Parallel Computing Using Navigational Programming

Message Passing (MP) and Distributed Shared Memory (DSM) are the two most common approaches to distributed parallel computing. MP is difficult to use, whereas DSM is not scalable. Performance scalability and ease of programming can be achieved at the same time by using navigational programming (NavP). This approach combines the advantages of MP and DSM, and it balances convenience and flexibility. Similar to MP, NavP suggests to its programmers the principle of pivot-computes and hence is efficient and scalable. Like DSM, NavP supports incremental parallelization and shared variable programming and is therefore easy to use. The implementation and performance analysis of real-world algorithms, namely parallel Jacobi iteration and parallel Cholesky factorization, presented in this paper supports the claim that the NavP approach is better suited for general-purpose parallel distributed programming than either MP or DSM.     

可预测扩展并行性能的并行程序设计模型

ＢＳＰ（Ｂｕｌｋ－Ｓｙｎｃｈｒｏｎｏｕｓ）模型是独立于并行体系结构的,即可作为并行计算模型又可看作并地程序设计模型,该模型使程序员在算法设计阶段和编程调试阶段可精确地分析和预测并行程序性能。ＢＳＰ程序可移植性强,可在多种并行系统发ＰＶＭ,ＭＰＩ等上实现。     

Experience with parallel programming using code templates

For almost a decade we have been working at developing and using template-based models for parallel computing. Template-based models separate the specification of the parallel structuring aspects from the application code that is to be parallelized. A user provides the application code and specifies the parallel structure of the application using high-level icons, called templates. The parallel programming system then generates the code necessary for parallelizing the application. The goal here is to provide a mechanism for quick and reliable development of coarse-grain parallel applications that employ frequently occurring parallel structures. Our initial template-based system, FrameWorks, was positively received but had a number of shortcomings. The Enterprise parallel programming environment evolved out of this work. Now, after several years of experience with the system, its shortcomings are becoming evident. Controlled experiments have been conducted to assess the usability of our system in comparison with other systems. The paper outlines our experiences in developing and using these systems. A list of desirable characteristics of template-based models is given. The FrameWorks and Enterprise systems are discussed in the context of these characteristics and the results of our usability experiments. Many of our observations are relevant to other parallel programming systems, even though they may be based on different assumptions. Although template-base models have the potential for simplifying the complexities of parallel programming, they have yet to realize these expectations for high-performance applications. © 1998 John Wiley & Sons, Ltd.     

任务并行编程模型研究与进展

任务并行编程模型是近年来多核平台上广泛研究和使用的并行编程模型,旨在简化并行编程和提高多核利用率.首先,介绍了任务并行编程模型的基本编程接口和支持机制;然后,从3个角度,即并行性表达、数据管理和任务调度介绍任务并行编程模型的研究问题、困难和最新研究成果;最后展望了任务并行未来的研究方向.     

MPI并行编程环境的研究

以RISC工作站或高档微机通过LAN连接的机群系统已经成为并行计算的主流技术，研究适应机群系统的并行编程环境自然重要起来。在众多的并行编程环境中，应用较为广泛的有消息传递接口(MPI)标准和并行虚拟机(PVM)环境。本文重点分析了MPI编程环境，并出给了MPI并行程序设计的基本方法。     

并行测试技术在自动测试系统中的应用

并行测试拥有减少测试时间、降低测试成本的强大优势,正成为研究热点之一。首先详细分析了并行测试的基本概念,介绍了目前实现并行测试可以采用的两大类4种结构,对这4种结构各自的优缺点进行了比较。接着以多线程并行测试程序为例描述了并行测试程序中同步、异步和单线程的三种模型,最后重点对多线程并行测试实现中几个值得注意的重要问题进行了讨论。