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在分布式网络系统中,为了实现系统协调一致的工作,必须要有相应的同步互斥算法来保证临界资源的互斥访问和操作.介绍了Ricart & Agrawla算法的基本思想、卫星编队飞行系统层次网络环境结构的基本特点,针对系统结构背景,详细介绍了改进后算法的基本方法和消息处理实现流程. 相似文献
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一种基于消息槽的K资源互斥算法 总被引:1,自引:0,他引:1
在分布式操作系统等一些有多个进程同时活跃的应用中,必须妥善解决不同进程对资源的需求,即同步与互斥问题.文章提出了一种基于消息槽的K资源互斥算法,介绍了该算法的原理,详细描述了该算法的运作过程,并进行了深入的分析.分析结果表明,该算法能够有效地满足K资源分布式环境下同步与互斥的要求. 相似文献
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<正> 在Win32程序设计中,为了实现多个线程对某一共享资源的正确访问,常常需要多个线程协调运行,这就是线程间的同步。win32提供了几种同步对象,如事件对象、互斥对象、关键区对象等,这里,仅简单探讨使用关键区对象实现线程间同步的方法。 关键区对象是Win32提供的一种对共享资源进行互斥访问的同步对象,它类似于互斥对象,但其仅适用于单个进程中 相似文献
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在分布式网络系统中,为了实现系统协调一致的工作,必须要有相应的同步互斥算法来保证临界资源的互斥访问和操作。介绍了Ricart & Agrawla算法的基本思想、卫星编队飞行系统层次网络环境结构的基本特点,针对系统结构背景,详细介绍了改进后算法的基本方法和消息处理实现流程。 相似文献
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分布式共享存储体系结构是当今并行计算机的主要发展方向.在注重性能指标的多处理器系统中通常采用硬件手段解决高速缓存一致性问题.高速缓存的一致性设计成为共享存储多处理器系统的关键技术,直接关系到系统的性能、正确性和可用性.该文介绍几种典型的基于目录的一致性协议,并分析共享存储器多处理器系统中一致性协议的实现技术. 相似文献
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提高冗余服务性能的动态容错算法 总被引:12,自引:0,他引:12
针对分布式应用的性能要求,引入了负载平衡机制,以便对activere plication和primary backup容错算法进行权衡.提出一种基于冗余服务的动态容错算法RAWA(read-any-write-any),能根据系统负载状况动态改变请求的quorum,不但提高了请求的处理速度,而且以一种简单、有效的方式实现了负载平衡.结合所提出的一致性维护和互斥访问机制,该算法可以适用于嵌套访问和状态服务.另外,还分析了RAWA算法的性能,并通过在CORBA平台上与其他容错算法的对比测试,证明RAWA算法在 相似文献
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The classification of various types of processes is an important factor in large-scale distributed systems such as, grid and cloud platforms. Moreover, the coordination and control of distributed processes are research challenges in presence of unpredictable network partitioning and distributed semaphores. The process classification is important in order to allocate and schedule distributed processes enhancing overall resource utilization and throughput. The schedulers employ patterns of resource affinities of concurrent processes in order to make scheduling decisions affecting overall resource utilization in a system, where resource affinity patterns of a process may not be static. This paper proposes an estimation model and a classifier algorithm to queuing processes based on respective resource affinities. The kernel-level software architecture is designed to control scheduling of distributed processes based on classification for enhanced throughput. The classifier algorithm tracks the resource affinities of processes based on execution traces and the control algorithm performs process scheduling. Experimental results indicate that the classifier algorithm successfully manages process queues based on resource affinities of processes and, the control algorithm successfully monitors scheduler activation for a set of processes. 相似文献
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在操作系统中实现分布共享存储、存储管理和文件系统的集成 总被引:3,自引:0,他引:3
开发分布共享存储系统的目的是为了在分布式存储器的基础上构造逻辑上的共享存储器模型,对于如何在共享存储器模型的基础上为用户进程构造虚拟空间,传统的分布共享系统并未给予足够的重视。只有在操作系统中把分布共享存储技术、存储器管理和文件系统结合起来,才能充分发挥分布共享存储技术具有的能力。基于以上思想,在文中提出了一个实现了分布共享存储的操作系统模型,并分析了该模型一个实现原型,讨论该原型具有的优缺点。通过在操作系统中取消进程的逻辑空间,使进程直接在文件上运行,该模型不仅能够实现分布共享存储,而且和许多传统操作系统以及传统分布共享存储系统相比,具有许多优点。该操作系统实现了分布共享存储技术和操作系统中的存储管理以及文件系统的完美结合。 相似文献
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《IEEE transactions on pattern analysis and machine intelligence》1985,(4):396-416
A distributed program is a collection of several processes which execute concurrently, possibly in different nodes of a distributed system, and which cooperate with each other to realize a common goal. In this paper, we present a design of communication and synchronization primitives for distributed programs. The primitives are designed such that they can be provided by a kernel of a distributed operating system. An important feature of the design is that the configuration of a process, i.e., identities of processes with which the process communicates, is specified separately from the computation performed by the process. This permits easy configuration and reconfiguration of processes. We identify different kinds of communication failures, and provide distinct mechanisms for handling them. The communication primitives are not atomic actions. To enable the construction of atomic actions, two new program components, atomic agent and manager are introduced. These are devoid of policy decisions regarding concurrency control and atomic commitment. We introduce the notion of conflicts relation using which a designer can construct either an optimistic or a pessimistic concurrency control scheme. The design also incorporates primitives for constructing nested atomic actions. 相似文献
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针对在多目标交互系统中,因查询方式致使交互节点资源受限的问题,提出了由事件触发的分布式控制方案。设计了分布式多目标虚拟交互系统,并采用Phantom Omni设备作为交互主端进行了仿真实验。在事件触发机制的情况下,系统每次单个对象交互视为完成一次事件触发,多个对象交互产生的触发事件采用分布式处理。在交互过程中,交互对象依据自身节点信息向控制系统发送交互过程中的采样值,并在Phantom Omni设备完成再现,操作者经由Phantom 0mni设备对交互状态进行感知。实验结果表明,该控制方案能够充分利用系统的节点资源,系统的动态特性能满足交互控制需求。 相似文献
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《IEEE transactions on pattern analysis and machine intelligence》1985,(8):774-783
A distributed system is viewed as a set of objects and processes utilizing the objects. If a shared object, known as a resource, is accessed concurrently, some mechanism is necessary to control use of the resource in order to satisfy the consistency and fairness requirements associated with the resource. These mechanisms are termed resource controllers. 相似文献
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《Journal of Parallel and Distributed Computing》1999,58(2):260-300
High-level parallel programming models supporting dynamic fine-grained threads in a global object space are becoming increasingly popular for expressing irregular applications based on sophisticated adaptive algorithms and pointer-based data structures. However, implementing these multithreaded computations on scalable parallel machines poses significant challenges, particularly with respect to object caching. Object caching techniques must be able to tolerate unresponsive processors and protocol handler occupancy delays. This paper examines whether these challenges can be offset by leveraging responsive general-purpose communication architectural features (such as remote memory access and atomic operations), possibly compensating for the lack of more sophisticated hardware primitives by relying upon increased involvement of the run-time system and the compiler. A detailed performance analysis of four irregular applications, using the Illinois Concert System on the Cray T3D and the SGI Origin 2000, finds that existing software distributed shared memory (DSM) systems are capable of delivering good performance only in the presence of a high level of responsive communication architecture support (specifically, support for remote atomic operations). Recognizing that this situation stems from the synchronous request–reply nature of DSM protocols, we present a composable object caching framework, called view caching, which exploits knowledge of application data access semantics to construct custom protocols that require reduced processor synchronization. View caching protocols are more tolerant to responsiveness and occupancy delays and are able to exploit even lower level responsive communication primitives (such as nonatomic remote memory accesses) for a performance benefit. 相似文献
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Atomic broadcast is a fundamental problem of distributed systems: It states that messages must be delivered in the same order to their destination processes. This paper describes a solution to this problem in asynchronous distributed systems in which processes can crash and recover. A consensus-based solution to atomic broadcast problem has been designed by Chandra and Toueg for asynchronous distributed systems where crashed processes do not recover. We extend this approach: it transforms any consensus protocol suited to the crash-recovery model into an atomic broadcast protocol suited to the same model. We show that atomic broadcast can be implemented requiring few additional log operations in excess of those required by the consensus. The paper also discusses how additional log operations can improve the protocol in terms of faster recovery and better throughput. To illustrate the use of the protocol, the paper also describes a solution to the replica management problem in asynchronous distributed systems in which processes can crash and recover. The proposed technique makes a bridge between established results on weighted voting and recent results on the consensus problem. 相似文献