Windows95／98环境中的并行程序设计

介绍了进程、线程的概念和联系以及Windows95／98操作系统的多任务特点及在此环境下的并行程序设计;通过分析比较了Windows95/98进程与线程的生命周期与管理;讨论了进程、线程之间诸如同步等通信问题及相关编程方法;最后简要介绍了笔者参与设计的一个项目中涉及的多任务问题。     

第四讲 兼容性和可靠性

Windows 95被设计成可以提供一种安全和平稳转接方式的新操作系统,它通过对已有的设备驱动器和MS-DOS及Windows应用程序的支持,在已有的软硬件上工作。 Windows 95不但对基于MS-DOS、Win 16和Win 32的应用程序提供更多的支持,而且还对出错的应用程序提供高级的系统保护功能,从而在Windows 3.1的基础上进一步提高了系统可靠性。不仅在运行MS-DOS和Win 16应用程序时系统性能有很大提高,而且更突出的是为Win 32应用程序提供了一个可靠、高性能的运行平台。本讲的练习部分将向您展示Windows 95的增强保护模式如何帮助用户同时运行多个应用程序。 Windows 95是一个可靠的、多线程的、真正的抢先多任务系统。因此,Windows 95允许用户同时执行多项任务。例如,打印文档、格式化磁盘以及重算电子表格。Windows 95具备多线程能力,这意味着在单个任务中一次可以执行多个线程。一个线程实际上是在一段时间内正在执行的进程(代码单元)的一个组件。一个进程本质上是一个应用程序。在Windows 95中,MS-DOS应用程序和16位Windows应用程序的每一进程只有一个线程。32位Windows应用程序的每一进程可以有多个线程。换句话说,Windows 95允许一个应用程序在同一时间运行多个代码单元。     

Windows95下多线程应用分析

基于线程的多任务是Windows 95的新概念。一个Win32应用程序可以由不止一个进程组成,而一个进程可以由不止一个线程组成。线程是一个代码单元,在操作系统中运行时标志着代码运行流。程序员用户可定义独立的线程执行体,以便控制程序中每个片段的执行,从而管理程序的运行方式。与Windows 3.1下Win16应用程序的协同多任务方式不同,Windows 95中Win32应用程序采取的是抢占式多任务方式,即同时执行多个进程和多个线程。 每个进程都有私有的虚拟地址空间,进程的所有线程共享同一地址空间。线程是操作系统为其分配CPU时间的基本     

C＋＋Builder3.0编程技巧与实践（六）——多线程技术实现

线程作为Windows95抢先式多任务的基础,是Windows95程序分配CPU时间片的基本实体。每个进程都由一个或几个线程组成,各线程协同完成指定操作,并根据其调度优先级分配CPU。线程具有进程的许多特征,又称为轻量级进程。但线程自己基本上不拥有系统资源,仅占有一点在运行中必不可少的资源,例如：线程的机器寄存器、内核堆栈、线程环境块和用户推栈等。一个应用程序可以由不止一个进程组成,每个过程可以由多个线程组成（至少包括一个线程,称为主线程）,同一进程中线程的切换不会引起进程的切换。因此,线程调度的开销远小于进程调度…     

Windows95的稳固性

相对于Windows 3. x来说,Windows 95在系统稳定性方面作了很大的改进,使之成为当今PC机操作系统的主流。改进主要方面在于:局部重新引导、虚拟设备驱动程序的线程清除机制、线程状态的跟踪及虚拟设备驱动程序参数的有效性检查。     

Delphi VCL的多线程安全问题

多线程程序设计对于多数Windows用户和程序员来说,是一个新的技术,因此在Windows95以前的Windows并不支持线程的概念(WindowsNT除外).当Windows提供了对线程的支持时,将线程和Delphi语言联系起来时又会提出这样的问题:在Delphi中进行多线程编程时,要使用哪些VCL构件,这是安全的吗?换言之,DelphiVCL多线程是安全的吗?     

Windows95/NT环境下MFC多线程编程技术Step By Step

我们在设计应用程序的时候,常常需要采用并行编程机制来完成各种各样的任务,在单GPU的机器上,也就是要将CPU时间按照一定的算法分配给各个任务,轮流处理各个任务。在Windows95/NT环境下能够同时运行多个应用程序,这也就是所谓的并行多任务。实际上,Windows95/NT支持所谓的多线程技术。在32位Windows95/NT下,我们可以用多线程编程技术来实现我们需要的并行编程技术。线程很类似于子程序。一个应用程序能够产生多个线程并同时执行。线程使得我们能够在多应用中进一步实现多任务。     

Windows NT的线程及其编程技术

线程(Thread)是Windows NT引入的先进技术之一。实际上,如果没有线程可能就不会有Windows NT的占先式(Preemptive)多任务。因为线程是Windows NT的唯一执行单元,Windows NT就是靠线程的优先级及分配给线程的CPU时间来调度线程,进而达到占先式多任务目的的。Windows NT本身的许多应用程序也利用了线程的特性来满足用户的需要,如Programm Manager、Task Manager等。为了使开发的应用程序可利用线程完成特定任务,Windows NT也为开发人员提供了编程接口。因线程对多数开发人员     

Windows95稳固性进一步增强

系统范围内稳固性增强 Windows 95在系统范围内进行改进,导致了一个比Windows 3.1更加坚固的操作系统环境。这些改进体现在: ·更佳的局部重新引导 ·进程结束时虚拟设备驱动程序(VxD)的线程清     

Solaris线程探讨

一般来说,计算机中正在执行的程序称作进程(process),线程(thread)是指进程中单一顺序的控制流。现在大多数操作系统。如Solaris 2.x、Mac、Windows NT/95等都支持线程的概念,把线程作为基本的执行单位。 Solaris 2.x操作系统是Sun公司较新的操作系统,它有基于SPARC的工作站版本和基于Intel微机的x86版本,线程是其中的一大特点,本文讲述了线程的基本概念和Solaris上线程程序的编写。     

多处理机环境下线程模型性能评测与分析

在线程环境设计中存在三种结构不同的线程模型:多对一、一对一和多对多,一直以来,线程模型的特性分析仍然主要位于感性层面,缺乏完整的测试数据验证。FreeBSD5提供了基于三种线程模型的线程环境,为评测不同线程环境的性能提供了条件。论文以FreeBSD5下的测试结果为基础,结合Linux下一对一模型线程库NPTL的测试结果,分析了三种模型的不同特点,指出一对一模型和多对多模型均具有良好的性能,同时,基于SchedulerActivations的多对多模型也有很大的发展空间。     

Parallel evolution strategy on grids for the protein threading problem

The protein threading problem is the problem of determining the three-dimensional structure of a given but arbitrary protein sequence from a set of known structures of other proteins. This problem is known to be NP-hard and current computational approaches to threading are unrealistic for long proteins and/or large template data sets. In this paper, we propose an evolution strategy for the solution of the protein threading problem. We also propose three parallel methods for fast threading. Our experiments produced encouraging preliminary results in term of threading energy as well as significant reduction in threading time.     

An Algorithm for Simultaneous Backbone Threading and Side-Chain Packing

To utilize fully all available information in protein structure prediction, including both backbone and side-chain structures, we present a novel algorithm for solving a generalized threading problem. In this problem we consider simultaneous backbone threading and side-chain packing during the process of a protein structure prediction. For a given query protein sequence and a template structure, our goal is to find a threading alignment between the query sequence and the template structure, along with a rotamer assignment for each side-chain of the query protein, which optimizes an energy function that combines a backbone threading energy and a side-chain packing energy. This highly computationally challenging problem is solved through first formulating this problem as a graph-based optimization problem. Various graph-theoretic techniques are employed to achieve the computational efficiency to make our algorithm practically useful, which takes advantage of a number of special properties of the graph representing this generalized threading problem. The overall framework of our algorithm is a dynamic programming algorithm implemented on an optimal tree decomposition of the graph representation of our problem. By using various additional heuristic techniques such as dead-end elimination, we have demonstrated that our algorithm can solve a generalized threading problem within a practically acceptable amount of time and space, the first of its kind.     

An Algorithm for Simultaneous Backbone Threading and Side-Chain Packing

To fully utilize all available information in protein structure prediction, including both backbone and side-chain structures, we present a novel algorithm for solving a generalized threading problem. In this problem, we consider simultaneously backbone threading and side-chain packing during the process of a protein structure prediction. For a given query protein sequence and a template structure, our goal is to find a threading alignment between the query sequence and the template structure, along with a rotamer assignment for each side-chain of the query protein, which optimizes an energy function that combines a backbone threading energy and a side-chain packing energy. This highly computationally challenging problem is solved through first formulating this problem as a graph-based optimization problem. Various graph-theoretic techniques are employed to achieve the computational efficiency to make our algorithm practically useful, which takes advantage of a number of special properties of the graph representing this generalized threading problem. The overall framework of our algorithm is a dynamic programming algorithm implemented on an optimal tree decomposition of the graph representation of our problem. By using various additional heuristic techniques such as the dead-end elimination, we have demonstrated that our algorithm can solve a generalized threading problem within practically acceptable amount of time and space, the first of its kind.     

利用Java的多线程技术在Web站点的主页中的实现动画

越来越多的Web站点的主页引入了动画技术。本文针对Java的多线程技术,详细论述了它的概念和原理,并提出了在主页中利用多线程技术实现动画的方法。     

操作系统多线程实现技术研究

本文详细描述了二种进程内我线程实现技术 核心线程实现技术,多线库实现技术,并对比分析了产的优缺点,在此基础上,总结了现代操作系统采用的多线程实用技术一混合实现技术。     

多核多线程处理器的发展及其软件系统架构

首先介绍了关于multi—cole（多核）、multi—threading（多线程，特指硬件线程）处理器的最新发展情况，然后介绍了基于MIPS体系结构的多核处理器的特点。针对多核处理器，给出了在路由器中软件的架构，并探讨了在发展多核系统软件方面给中国的系统软件业带来的机遇。     

Amino acid residue environments and predictions of residue type.

The determination of a protein's structure from the knowledge of its linear chain is one of the important problems that remains as a bottleneck in interpreting the rapidly increasing repository of genetic sequence data. One approach to this problem that has shown promise and given a measure of success is threading. In this approach contact energies between different amino acids are first determined by statistical methods applied to known structures. These contact energies are then applied to a sequence whose structure is to be determined by threading it through various known structures and determining the total threading energy for each candidate structure. That structure that yields the lowest total energy is then considered the leading candidate among all the structures tested. Additional information is often needed in order to support the results of threading studies, as it is well known in the field that the contact potentials used are not sufficiently sensitive to allow definitive conclusions. Here, we investigate the hypothesis that the environment of an amino acid residue realized as all those residues not local to it on the chain but sufficiently close spatially can supply information predictive of the type of that residue that is not adequately reflected in the individual contact energies. We present evidence that confirms this hypothesis and suggests a high order cooperativity between the residues that surround a given residue and how they interact with it. We suggest a possible application to threading.     

一种基于VC++的电子体温计读数自动识别方法

介绍了一种基于VC++的医用电子体温计的自动识别方法。根据电子体温计显示的特点,提出了一种利用机器视觉识别电子体温计读数的一种新方法。该方法利用扫描法进行字符区域的定位和单个字符的分割;利用穿线法识别数字字符;利用穿线法和模板匹配相结合的方法识别小数点。实验结果表明,该算法识别率高,识别速度快。