Win32中多进程间的内存共享数据通信方法

支持多任务操作是 Windows 操作系统的主要优点之一。本文针对32位 Windows 的技术特点,提出了基于共享内存的多进程间数据传输方法,并详细讨论了通过内存映射文件的内存共享实现技术。给出编程实例之后,本文对共享内存技术做了总结。     

Win32中多进程间的内存共享数据通信方法

支持多任务操作是Windows操作系统的主要优点之一。本文针对32位Windows的技术特点,提出了基于共享内存的多进程间数据传输方法,并详细讨论了通过内存映射文件的内存共享实现技术。给出编程实例之后,本文对共享内存技术做了总结。     

共享内存在高效进程间通信中的应用研究

在Linux系统中两个或多个进程间通信,是实现计算机内部传递信息的机制,它们之间是同步的关系,多个协作进程间完成数据的共享、消息的交换。文章基于Ubuntu 12操作系统环境,通过共享内存通信的方式设计一种基于多进程的同步关系,它们共享内存的同步通信机制。文章详细描述了该机制的设计原理和实现方式,并采用内核文件shm.h实现了进程同步,通过内存片段共享机制减少多个进程之间的切换时间,实现了共享内存在多进程间的高效通信。     

基于内存映射文件的数据交换技术及其在测控软件中的应用

系统介绍了在Windows98下，通过使用内存映射方式，实现应用程序间信息实时交互的原理，同时，给出了使用这种方法实现应用程序通信的实例。     

Linux中多种内存共享机制及其应用探究

Linux操作系统广泛运用在服务器运维、嵌入式软件设计和移动端应用开发中,而对于Linux进程间通信机制的理解和研究又决定了软件之间数据通信的效率。Linux有多种方式实现进程之间的通信,包括管道、消息队列、信号量、socket、内存共享等,其中内存共享是效率最高的一种方式,实现了不同进程对同一块物理内存的访问,不需要陷入内核态中进行内核空间和用户空间的数据拷贝,大大提高了通信效率。文章介绍了在Linux操作系统中内存共享的4种不同实现方式,同时介绍了不同实现方式在原理和应用场景上的区别。     

如何提高WinNT/2000的安全性--内核加固实现一个真正强壮的操作系统

Windows 2000支持多处理器系 统、安全性文件系统(例如目录的读 写限制),从Windows NT 3.51开始 就已经支持C2级的安全测评,是一个 真正的32位操作系统,其核心不包含 16位代码(16位代码仅存在于支持16 位应用程序的代码中)、规定16位代 码运行在其独立的地址空间内,系统 是完全可重入的、规定共享的内存, 只对于有相同共享内存区域的进程是 可见的(在Win 32 API中称为"文件 映射对象")。以上这些特点构成了一 个强大的Windows 2000系统。     

管理网络共享文件夹

目前,越来越多的人使用Windows Server2003／2008操作系统,并且,在办公时经常需要使用文件的共享功能。笔者所在单位中有十几个部门需要采用不同的权限和方式来对办公文件等进行共享。     

基于内存映射文件的仿真系统进程间数据

针对某综合仿真系统进程间进行大数据量快速实时传输的需求,在分析进程间数据传输方法的基础上,采用内存映射文件技术,实现了进程间大数据量的实时传输。结果表明,基于内存映射文件技术的进程间大数据量的快速实时传输,在某综合仿真系统中工作可靠、稳定。     

内存映射文件及其在广义舒适度仿真中的应用

本文分析了win32系统下的虚拟内存系统模式及内存映射文件的工作机理,介绍了如何用windows API将文件映射至内存,利用原型页表入口技术实现了多个进程之间的数据共享。通过实验数据得出,采用内存映射文件读取高速服役列车的广义舒适度仿真中的超大数据文件,其效率远远高于传统的基于文件I/O方式的数据存取。     

O＆O CleverCache专业版＆服务器版

可以优化Windows2003／Windows7下内存和文件缓存管理,从而使得性能大幅度提高,加快系统的运行速度,不需要任何硬件上的更新,也不会降低系统的稳定性。安装时选择专业版或服务器版,无需任何的配置和重启动,只要5分钟就可以激活系统中未使用的资源。在服务器运行的较长时间中,由于主存储器超载或太多的进程的运行,往往会造成应用程序或操作系统的宕机与崩溃,通过服务器版的实时监控,     

基于小波变换的高分辨率遥感图像复原算法实现

为了促进遥感图像的后续研究,针对高分辨率遥感图像实现了基于小波变换的迭代收缩（IST）图像复原算法。考虑到算法在复原过程中对内存需求较大,实现过程中采用内存映射文件的方法,将高分辨率遥感图像映射到进程地址空间。针对分块复原图像时通常会伴有边缘跳变现象,影响拼接后的图像质量的问题,使用特殊分块策略对图像进行分块处理。复原算法在VC平台下实现,通过遥感图像复原实验,并对复原图像进行评价分析,复原性能和效率良好。     

A 512 Mb Two-Channel Mobile DRAM (OneDRAM) With Shared Memory Array

A 512 Mb two-channel mobile DRAM (OneDRAM) is developed with 90 nm technology. It can operate on a 1.8 V power supply as two separate mobile DDR or SDR DRAMs through each channel with maximum data rate of 333 Mbps/pin because of its exclusive accessibility from each channel to memory arrays. Data exchange between two channels is also possible by sharing one common memory array, and a new control scheme of DRAM for this sharing is proposed. The new control scheme is based on direct addressing mode to achieve compatibility with normal DRAM interface together with fast data transfer speed between two channels.      

Privacy-Preserving Public Auditing for Non-manager Group Shared Data

By the widespread use of cloud storage service, users get a lot of conveniences such as low-price file remote storage and flexible file sharing. The research points in cloud computing include the verification of data integrity, the protection of data privacy and flexible data access. The integrity of data is ensured by a challenge-and-response protocol based on the signatures generated by group users. Many existing schemes use group signatures to make sure that the data stored in cloud is intact for the purpose of privacy and anonymity. However, group signatures do not consider user equality and the problem of frameability caused by group managers. Therefore, we propose a data sharing scheme PSFS to support user equality and traceability meanwhile based on our previous work HA-DGSP. PSFS has some secure properties such as correctness, traceability, homomorphic authentication and practical data sharing. The practical data sharing ensures that the data owner won’t loss the control of the file data during the sharing and the data owner will get effective incentive of data sharing. The effective incentive is realized by the technology of blockchain. The experimental results show that the communication overhead and computational overhead of PSFS is acceptable.     

新型飞行控制系统总线数据处理方法优化设计

针对新型飞控采集器采集数据流数增多、试飞模式改变的问题,对原有飞行控制系统总线数据处理软件进行优化设计。使用内存影射技术管理原始数据的读写操作,同时优化设计校线文件管理模块和参数文件管理模块,实现了多流、多表号飞控数据的快速处理。通过工程使用验证,软件有效解决了多流、多表号飞行控制系统总线数据处理问题。     

安全高效的分布式加密存储系统设计

Proxy Re-encryption (PRE) is greatly concerned by researchers recently. It potentially has many useful applications in network communications and file sharing. Secure distributed cryptographic file system is one of its applications. But the practical applications of PRE are few. And even fewer of them are tested by systematically designed experiments. Appling a couple of representative algorithms proposed by BBS, Ateniese, Shao, et al., a distributed file system is designed. In the system, some substitute mechanisms such as data dispersal, dynamic file sharing, are well-applied. A lot of features such as flexible authorization and data redundancy are embraced in the system. The comparison evaluation justified that the system is more practical and efficient.     

基于NET的网络文件存储管理系统设计与实现

随着网络技术的发展,网络文件存储系统日益普及。为了实现网络资源共享,提高资源利用率,通过ASP.NET技术,采用ASP.NET 2.0和C#开发语言,以Microsoft Visual Studio 2008作为集成开发环境,结合SQL Server 2005数据库软件,设计实现了一个相对完善的网络文件存储管理系统。系统利用B/S模式结构,实现了用户登录、文件夹管理以及文件管理等功能,为网络文件管理提供了高效便捷的资源交换手段,具有一定的实用价值。     

A new buffer management scheme for hierarchical shared memoryswitches

We study a multistage hierarchical asynchronous transfer mode (ATM) switch in which each switching element has its own local cell buffer memory that is shared among all its output ports. We propose a novel buffer management technique called delayed pushout that combines a pushout mechanism (for sharing memory efficiently among queues within the same switching element) and a backpressure mechanism (for sharing memory across switch stages). The backpressure component has a threshold to restrict the amount of sharing between stages. A synergy emerges when pushout, backpressure, and this threshold are all employed together. Using a computer simulation of the switch under symmetric but bursty traffic, we study delayed pushout as well as several simpler pushout and backpressure schemes under a wide range of loads. At every load level, we find that the delayed pushout scheme has a lower cell loss rate than its competitors. Finally, we show how delayed pushout can be extended to share buffer space between traffic classes with different space priorities     

Error counter-based negative acknowledgement mode in CCSDS file delivery protocol

Deep space communication has its own features such as long propagation delays,heavy noise,asymmetric link rates,and intermittent connectivity in space,therefore TCP/IP protocol cannot perform as well as it does in terrestrial communications.Accordingly,the Consultative Committee for Space Data Systems (CCSDS) developed CCSDS File Delivery Protocol (CFDP),which sets standards of efficient file delivery service capable of transferring files to and from mass memory located in the space segment.In CFDP,four optional acknowledge modes are supported to make the communication more reliable.In this paper,we gave a general introduction of typical communication process in CFDP and analysis of its four Negative Acknowledgement (NAK) modes on the respect of file delivery delay and times of retransmission.We found out that despite the shortest file delivery delay,immediate NAK mode suffers from the problem that frequent retransmission may probably lead to network congestion.Thus,we proposed a new mode,the error counter-based NAK mode.By simulation of the case focused on the link between a deep space probe on Mars and a terrestrial station on Earth,we concluded that error counter-based NAK mode has successfully reduced the retransmission times at negligible cost of certain amount of file delivery delay.     

Memory-a RAM link for high speed

Work on an open standard that defines a ring for linking fast memories and processors is discussed. The interface, called RamLink, will provide high performance even when dynamic RAMs (DRAMs) with internal caching mechanisms are ineffective. In addition to RAM, RamLink will support flash nonvolatile memory, read-only memory, and even memory-mapped disks. Mismatching, collision avoidance, and problems that must be addressed by RamLink are examined. A detailed simulation model for RamLink written in Simula, an object-oriented language, is briefly described     

Intelligent file transfer for smart handheld devices based on mobile cloud computing

Most methods of file transfer between mobile devices have to take considerable time to obtain and input target identifiers. To speed up file sharing of mobile devices, an intelligent file transfer framework is designed based on mobile cloud computing. Only single‐finger action is performed in the proposed framework, which just drags the file to the target face on the touchscreen of a mobile device. The dragged file can be transmitted to the target receiver who can either get the file immediately as her/his mobile device is online or receive the file later after connecting to the Internet. Our framework provides the following features: (i) users do not need to know the target identifier in advance; (ii) users do not need to input identity information by themselves; and (iii) users can select a specific target among multiple candidates from the camera of a mobile device. The intelligent file transfer framework reveals an efficient architecture and innovative user interfaces to transfer files between mobile devices, which can significantly reduce the complexity and difficulty of file sharing. An Android‐based prototype is implemented to verify the feasibility and superiority of our framework. Experimental results show that our approach outperforms existing schemes and can save large amounts of time in file sharing for mobile users. Copyright © 2015 John Wiley & Sons, Ltd.