多线程体系结构的几个核心问题

多线程计算机是控制流计计算机发展的融合,它是一种多指令流多数据流（ＭＩＭＤ）计算机,其特征首先表现在体系结构上。本文分析了多线程体系结构若干核心问题,并对多线程计算机的性能评价方法展开了初步的探讨。     

用Java程序演示程的并行执行

线程是现代计算机操作系统中的最重要概念之一,本文利用Java支持多线程编程的特性,设计出了两个演示多线程并行执行的Java程序,对地理解线程的概念起到非常好的帮助。     

多线程安全问题

Delphi VCL的多线程安全问题$安徽大学@胡学联     

多线程技术与并行计算

1 引言自七十年代以来,多线程技术已逐渐渗透到计算机体系结构的方方面面。出现了多线程结构的并行机,如Tera(1990),Stanford的DASH(1988),MIT的Alewife(1989),等;在操作系统方面,CMU的Mach/OS(1986),Solaris、AIX、Linux等Unix操作系统,以及目前流行的PC机操作系统Windows系列等,都已不同程度地采用了多线程技     

基于通用计算机的实时数字信号处理仿真系统

软件实现对信号的实时处理是基于通用的计算机信号处理仿真系统的一个重要发展方向。该文在通用计算机系统中通过对实时信号处理中块处理技术的应用，使用双缓冲满足数据的实时传输，利用多线程实现多任务的并行处理，给出了基于通用的计算机实现实时信号处理仿真系统的设计思想，并对块处理、双缓冲以及多线程在实现过程中的关键点进行了深入的剖析。该系统在处理诸如基带信号、下变频信号等速率满足要求的场合下，可使用通用计算机替代DSP系统。该仿真系统具有允许用户扩充或修改信号处理算法的特性。最后给出了对语音信号进行实时DSB实时调制的仿真实例。     

Linux多线程的互斥与同步控制及实践

随着计算机软硬件的发展,对计算机的执行效率的要求不断提高,多线程技术应运而生,现在被许多操作系统所支持。本文介绍了多线程系统中互斥与同步机制,在Linux系统下利用信号量操作及利用pthread多线程函数编程实现多线程间的互斥与同步控制,并以生产者和消费者问题为例进行分析与实践。     

一种新的多线程实现技术

本文提出了一种实现多线程机制的简单有效的新方案，它利用多机系统中原有的Ｃａｃｈｅ实现多线程功能，在很低的代价下实现了多机系统的多线程化，使应用程序的执行效率得到大幅度提高。     

多信息管理计算机远程集中控制系统研究

随着计算机技术的不断发展,我国计算机的应用上已经得到了长足的进步,计算机也开始取得了较好的使用.为了较好地解决计算机在使用过程中出现的多种问题,对计算机远程集中控制的系统进行研究就显得尤为重要.分析了多信息管理计算机远程集中控制系统的建立以及应用.     

Linux多线程的互斥与同步控制及实践

随着计算机软硬件的发展，对计算机的执行效率的要求不断提高，多线程技术应运而生，现在被许多操作系统所支持。本文介绍了多线程系统中互斥与同步机制，在Linux系统下利用信号量操作及利用pthread多线程函数编程实现多线程间的互斥与同步控制，并以生产者和消费者问题为例进行分析与实践。     

大数据文件和混合文件的多线程并行下载

在应用计算机模拟病例训练与考试系统的过程中,客户端时常需要在线下载许多大数据文件、音频和视频混合文件,系统响应速度是一个关键问题。研究了在RIA中实现多线程的技术方案,提出在多核计算机上有效实现多线程并行下载大数据文件、音频和视频混合文件的优化方法。算法分析与实验结果表明,提出的多线程并行下载技术能够加速计算机模拟病例系统模块的在线下载,显著优化了系统运行性能。     

多线程技术基于VB．NET的实现

多线程技术是实现需要并发执行的应用程序的较好选择,具有不可替代的作用。文中介绍了进程、线程以及应用程序域的概念及其相互之间的关系,讨论了VisualBasic.NET对多线程的支持。并从线程的创建与管理、线程取消、线程的优先级、线程的状态、线程池、线程的同步等方面展示了如何使用多线程编程技术来创建多线程应用程序。每个线程都需要资源,创建的线程过多,反而会降低应用程序的性能。在设计多线程应用程序时,应慎重对待,建立合理的系统模型,才能使应用程序获得最佳的性能。     

Analyzing and enhancing the parallel sort operation on multithreaded architectures

The sort operation is a core part of many critical applications (e.g., database management systems). Despite the large efforts to parallelize it, the fact that it suffers from high data-dependencies vastly limits its performance. Multithreaded architectures are emerging as the most demanding technology in leading-edge processors. These architectures include simultaneous multithreading, chip multiprocessors, and machines combining different multithreading technologies. In this paper, we analyze the memory behavior and improve the performance of the most recent parallel radix and quick integer sort algorithms on modern multithreaded architectures. We achieve speedups up to 4.69× for radix sort and up to 4.17× for quicksort on a machine with 4 multithreaded processors compared to single threaded versions, respectively. We find that since radix sort is CPU-intensive, it exhibits better results on chip multiprocessors where multiple CPUs are available. While quicksort is accomplishing speedups on all types of multithreading processers due to its ability to overlap memory miss latencies with other useful processing.     

Graphs for Mining-Based Defect Localization in Multithreaded Programs

Trends in modern multicore architecture design requires software developers to develop and debug multithreaded programs. Consequently, software developers must face new challenges because of bug patterns occurring at runtime and due to the non-deterministic behavior of multi-threaded program executions. This calls for new defect-localization techniques. There has been much work in the field of defect localization for sequential programs on the one side and on the localization of specific multithreading bugs on the other side, but we are not aware of any general technique for multithreaded programs. This paper proposes such an approach. It generalizes data mining-based defect-localization techniques for sequential programs. The techniques work by analyzing call graphs. More specifically, we propose new graph representations of multithreaded program executions as well as two mining-based localization approaches based on these representations. Our evaluation shows that our technique yields good results and is able to find defects that other approaches cannot localize.     

Recovering distributed objects

Distributed multithreaded applications operating in shared-nothing environments present challenges to classical fault tolerance mechanisms. The piecewise determinism assumption is lost (due to multithreading), and data must be replicated (because of the shared-nothing environment). In this paper, we explore a systematic approach to providing fault tolerance, by considering data-race-free programs that have the benefits of piecewise determinism and yet allow multithreading. We base our logging and recovery algorithm on a logical ring structure that allows the underlying distributed system to migrate threads, migrate and replicate objects, and perform multi-object transactions.     

多线程计算模型、体系结构与编译技术

1 引言在过去的30年里,计算机体系结构经历了长足的发展,超标量、超流水线、VLIW等先进思想显著地提高了计算机的性能,但这些单线程的体系结构在提高指令级并行度方面也面临着巨大的困难。多线程体系结构被认为是一种提高并行度的有效模型,它结合了数据流结构和传统的冯·诺依曼控制流结构,既保持了指令执行的高性能,又实现了处理器的高     

Power-efficient error tolerance in chip multiprocessors

The microprocessor industry is rapidly moving to the use of multicore chips as general-purpose processors. Whereas the current generation of chip multiprocessors (CMPs) target server applications, future desktop processors likely have tens of multithreaded cores on a single die. Various redundant multithreading (RMT) approaches exploit the multithreaded capability of current general-purpose microprocessors. These approaches replicate the entire program, running it as a separate thread using time or space redundancy. This guards the processor core against all errors, including those in combinational logic. Because RMT exploits the existing multithreaded hardware, it requires only a modest amount of additional hardware support for comparing results and, depending on the implementation, duplicating inputs.     

Real-Time Garbage Collection for a Multithreaded Java Microcontroller

We envision the upcoming of microcontrollers and systems-on-chip that are based on multithreaded processor kernels due to the fast context switching ability of hardware multithreading. Moreover we envision an extensive market for Java-based applications in embedded real-time systems. This paper introduces two new garbage collection algorithms that are dedicated to real-time garbage collection on a multithreaded Java microcontroller. Our garbage collector runs in a thread slot in parallel to real-time applications. We show that our algorithms require only about 5–10% of the processor time for an effective garbage collection concerning our real-time benchmarks.     

基于多线程结构的编译优化技术

编码优化是多线程技术中的一个重要组成部分,也是目前多线程研究中比较薄弱的环节。本文讨论了初步多线程换型中相关的编译优化技术,并给出了基本的分析和比较结果     

Helper threads via virtual multithreading

Memory latency dominates the performance of many applications on modern processors, despite advances in caches and prefetching techniques. Numerous prefetching techniques, both in hardware and software, try to alleviate the memory bottleneck. One such technique, known as helper threading improves single-thread performance on a simultaneous multithreaded architecture (SMT), which shares processor resources, including caches, among logical threads. It uses otherwise idle hardware thread contexts to execute speculative threads on behalf of the main thread. Helper threading accelerates a program by exploiting a processor's multithreading capability to run assist threads. Based on the helper threading usage model, virtual multithreading (VMT), a form of switch-on-event user-level multithreading, can improve performance for real-world workloads with a wall-clock speedup of 5.0 to 38.5 percent     

多线索DBMS设计环境构造及实验研究

文中介绍了一个多线索ＤＢＭＳ核心，它具有一般ＤＢＭＳ的基本功能，为不同的ＤＢＭＳ提供统一的设计环境。