UNIX系统C语言联机帮助系统的设计与实现

本文较详细地介绍了ＵＮＩＸ环境下Ｃ语言的联机帮助系统ｃｈｅｌｐ的设计与实现。该系统由一个辅助的ｓｈｅｌｌ程序和联机帮助系统自身构成。前者的作用在于加速系统的开发，使得在增删及修正帮助信息时系统的更新得以自动完成，后者包括各类帮助信息的正文，涉及ＡＮＳＩＣ与ＵＮＩＸＣ标准库函数的用法以及可被程序员任意剪裁的示例程序。     

对UNIX实时扩充的一点研究

本文讨论了实时应用中传统ＵＮＩＸ存在的一些不足，并且从实现机制上分析了产生这些不足的原因，以及常用的实时性扩充方法。另外，本文还较详细地介绍了一个典型的实时ＵＮＩＸ版本是如何对传统ＵＮＩＸ进行实时化扩充的。     

多机UNIX核心中的指令流控制结构—thread

Ｔｈｒｅａｄｓ－指令流结构成为多处理机ＵＮＩＸ操作系统中的一个基本结构。随着ＵＮＩＸ在多机环境下的不断开发，细颗粒开发，或者说指令级并发对提高系统的总处理能力显得越来越重要，并已从传统ＵＮＩＸ中的进程概念，发展为多处理机ＵＮＩＸ中的指令流／进程的概念。本文介绍了ｔｈｒｅａｄ的基本概念，ｔｈｒｅａｄ的构造，ｔｈｒｅａｄ的各种操作和多机ＵＮＩＸ中的一些实现算法。     

Digital UNIX 网络内核接口研究

该文介绍了ＤｉｇｉｔａｌＵＮＩＸ网络内核的组成,数据链路接口,应用程序接口以及ＳＴＲＥＡＭＳ与Ｓｏｃｋｅｔｓ的通信桥梁。各种接口都有一组系统调用和库函数,供应用程序调用实现网络通信。     

DOS／UNIX环境焉X.28通信平台及应用程序的设计与实现

本文介绍了我们设计开发的ＤＯＳ／ＵＮＩＸ环境下带ＭＯＤＥＭ控制的串行口驱动程序，驱动程序之上的Ｘ．２８通信平台以及平台的应用。ＤＯＳ下的底层驱动程序用驻留中断实现，ＵＮＩＸ下的驱动程序用ＵＮＩＸ的流机制实现，数据接收采用硬件中断，有效地防止了漏字符现象的发生。     

DOS／UNIX环境下X．28通信平台及应用程序的设计与实现

本文介绍了我们设计开发的ＤＯＳ／ＵＮＩＸ环境下带ＭＯＤＥＭ控制的串行口驱动程序、驱动程序之上的Ｘ．２８通信平台以及平台的应用。ＤＯＳ下的底层驱动程序用驻留中断实现，ＵＮＩＸ下的驱动程序用ＵＮＩＸ的流机制实现，数据接收均采用硬件中断，有效地防止了漏字符现象的发生。ＤＯＳ、ＵＮＩＸ下串行口驱动程序之上的Ｘ．２８通行平台提供了一致的可用于二次开发的编程原语。利用该平台可以实现ＤＯＳ／ＵＮＩＸ应用程序通过Ｘ．２５公共数据网或公共电话网的数据传输。本文还介绍了我们在平台上开发的Ｘ．２５ＰＤＮ上ＳｐｒｉｎｔＭａｉｌ用户端应用程序。     

COSIX BC的设计与实现

ＢＣ是一种支持任意精度算术运算的Ｃ风格语言。本文介绍在国产ＵＮＩＸ版本运行的ＣＯＳＩＸ ＢＣ的设计及其实现，着重描述了它的主要设计特点以及对传统ＢＣ的改进。并对它的一个实现版本进行性能方面的评价。     

用socket实现UNIX网络的数据广播

本文首先介绍了在ＵＮＩＸ系统中，ｓｏｃｋｅｔ通信原理，以及ｓｏｃｋｅｔ常用的系统调用，并在此基础上，给出用ｓｏｃｋｅｔ实现ＵＮＩＸ网络数据广播的一个程序实例。     

一种支持线索迁移的分布式存储结构

本文介绍一种基于ＵＮＩＸ的分布式存储结构，用于支持分布多系统中的机间线索迁移，同一地址空间中的多个线索实现为共享地址空间的多个轻权进程，这些进程核心视为普通的ＵＮＩＸ进程，本文主要讨论分式存储和线索迁移的实现机制。     

UNIX系统调用的实现技术

ＵＮＩＸ操作系统是目前较为广泛使用的操作系统，本文详细分析了ＵＮＩＸ系统调用的实现技术，提出了拦截和增加ＵＮＩＸ系统调用的方法，为改造ＵＮＩＸ操作系统提供了有效途径。     

基于POSIX线程库的线程池反馈算法的设计与实现

本文提出了一种基于POSIX线程库的线程池反馈算法,通过对线程池响应进间和吞吐量进行监控,对线程池的下一步行为进行决策,调整线程池中的线程数及线程单次处理的任务数。实验结果显示,这种算法能很好地稳定线程池吞吐量和响应时间,避免性能出现大幅波动。     

基于uClinux的NPTL线程库移植

在Linux2．6中,NPTL（native posix thread library）已取代Limux Threads成为glibc的首选线程库,但是在嵌入式操作系统中普遍使用的基于POSIX标准的线程库仍是Linux Threads。分析了NPTL线程库的内存管理机制,基于嵌入式操作系统uClinux无MMU的特性,修改了线程栈及uClibc库,实现了NPTL无uClinux上的移植,并在兼容性与效率两方面相对于Linux Threads线程库进行了测试。     

基于PVM的安全线程机制的研究

PVM并行虚拟机是一种广为使用的分布并行消息库,使用进程作为并行任务的基本单位。但是PVM不支持安全的线程机制。在研究借鉴先前研究经验的基础上,研究支持PVM线程安全的机制,在PVM库和POSIX线程库之上设计了支持PVM线程应用的库PTL,使基于进程的消息传递模型可以基于线程来实现。阐述了其设计原理,给出了程序设计示例,最后给出总结。     

基于面向对象技术重构遗留系统

针对目前正在运行中的部分遗留系统,通过面向对象的分析和设计方法,将其由面向过程的设计和实现重构改造成面向对象的实现,运用POSIX线程模式来取代遗留系统中的进程模式,以提升系统的功能、性能以及系统的可维护性,节省研发和维护成本。     

Thread Verification - An Experience Report

The paper details the author's thread verification experiences with four applications: Linux kernel code, the Red Hat Linux POSIX Thread library, a portable PThread library, which was developed by the author for NASA, and a HandyChecker prototype. Based on the author's experiences, the paper concludes with a list of challenges for the verification community.     

Integrating User-Level Threads with Processes in Scsh

Scsh, the Scheme shell, enables concurrent system programming with portable user-level threads. In scsh, threads behave like processes in many ways: each thread receives its own set of process resources; like Unix processes, new threads can inherit resources from the creating thread. The combination of scsh's interface to the POSIX API with user-level threads creates a number of design and implementation challenges: Scsh's abstractions for managing process resources raise interesting modularity issues, particularly in connection with first-class continuations. Scsh also provides an interface to the fork system call; its implementation must avoid common pitfalls that arise with a user-level thread system. This paper describes the design and implementation of the relevant abstractions and discusses the implications for programming-language and system design.     

基于Ninf-G的GridRPC系统的分析与改进

针对Ninf-G提出了改进方案,使得GridRPC系统能被用来实现局域网和网格环境下的并行编程,使用OpenMP来作为一个简单易用的编程环境,并采用POSIX线程创建基于GridRPC的多线程客户端,实现了此GridRPC系统的主要API,同时提出一个可持久化模型来提高系统的查询效率,并通过增加远程主机中的GridRPC代理来提供一个统一的接口,最后给出了在相关配置下对背包问题的求解效率分析.     

Monte Carlo implementation of financial simulation on Cell/B.E. multi-core processor

The processor evolution has reached a critical moment in time where it will soon be impossible to increase the frequency much further. Processor designers such as Motorola, Intel and IBM have all realised that the only way to improve the FLOP/Watt ratio is to develop multi-core devices. One of the most current examples of multi-core processors is the new Sony/Toshiba/IBM Cell/B.E. multi-core processor. For the suitability to run in parallel, Monte Carlo methods are often considered embarrassingly parallel. This paper describes how a common Monte Carlo based financial simulation can be calculated in parallel using the Cell/B.E. multi-core processor. The measured performance with the achieved multi-core speed-up is also presented. With the recent availability of this increasingly available technology, financial simulations can now be performed in a fraction of the time it used to. This can also be achieved with a limited power and volume budget using commercially available technology. The main challenge with multi-core devices is clearly the programmability. The work presented here describes how this challenge could be dealt with.A basic MPI library has been developed to handle the partitioning and communication of data. The thread creation follows a POSIX thread creation model. MPI together with POSIX make the application portable in between various multi-processor systems and multi-core devices. The conclusions made indicate that a function offload MPI implementation on the Cell/B.E. multi-core processor can efficiently be used to speed-up the Monte Carlo solution of financial simulations. The conclusions made herein are also applicable to other situations where an algorithm can be easily parallelized.     

Accelerating dissipative particle dynamics with multiple GPUs

Dissipative particle dynamics (DPD) simulation is implemented on multiple GPUs by using NVIDIA’s Compute Unified Device Architecture (CUDA) in this paper. Data communication between each GPU is executed based on the POSIX thread. Compared with the single-GPU implementation, this implementation can provide faster computation speed and more storage space to perform simulations on a significant larger system. In benchmark, the performance of GPUs is compared with that of Material Studio running on a single CPU core. We can achieve more than 90x speedup by using three C2050 GPUs to perform simulations on an 80∗80∗80 system. This implementation is applied to the study on the dispersancy of lubricant succinimide dispersants. A series of simulations are performed on lubricant–soot–dispersant systems to study the impact factors including concentration and interaction with lubricant on the dispersancy, and the simulation results are agreed with the study in our present work.     

The use of mTags for mandatory security: a case study

mTags is an efficient mechanism that augments inter‐thread messages with lightweight metadata. We introduce and discuss a case study that we have conducted in the use of mTags for realizing a kind of mandatory security. Although mTags can be implemented for any message passing thread‐based system, we consider an implementation of it in the POSIX‐compliant QNX Neutrino, a commercial microkernel‐based system. The approach to mandatory security that we adopt is Usable Mandatory Integrity Protection, which has been proposed in recent research. We call our adaptation of Usable Mandatory Integrity Protection using mTags, μMIP. We discuss the challenges we faced, and our design and implementation that overcomes these challenges. We discuss the performance of our implementation for well‐established benchmarks. We conclude with the observation that mTags can be useful and practical to realize mandatory security in realistic systems. Copyright © 2013 John Wiley & Sons, Ltd.