Loosely-Coupled Processes

松耦合流程

• 批准号: 9111912
• 负责人: Jayadev Misra
• 金额: $ 28.48万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-12-01 至 1995-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9111912&HistoricalAwards=false
• 关键词: Loosely; Coupled; Processes

Large-scale distributed programming, where processes communicate via messages, is a reality whereas large-scale shared variable programming remains an ill-understood activity. It is postulated that the distinction between these two classes is the type of communication-it is disciplined in the former case and arbitrary in the latter case. Furthermore, implementations of shared-variable systems on multiprocessors with individual caches pose several problems, including cache-coherence. This work attempts to impose certain disciplines on shared variable programming so that large-scale system design becomes feasible and the implementations avoid most of the issues associated with cache coherence. The plan of research is to identify a substantial class of shared-variable systems that enjoy some of the advantages of distributed (i.e., message-passing) systems. The systems will be constrained to a class called loosely-coupled, in which the computations of different processes are largely non-interfering even though they share variables. Loosely-coupled systems will acquire certain properties-such as absence of "race conditions" -normally associated with distributed systems. Designs of loosely-coupled systems will be accomplished without extensive analysis of scenarios based on execution sequences, process interactions or deadlock. Compositional proof theories for such systems will be developed and the efficient implementation of such a system on multiple-memory multiprocessor architectures will be indicated.

大规模分布式编程(其中进程通过消息进行通信)是现实，而大规模共享变量编程仍然是一种难以理解的活动。据推测，这两类之间的区别在于通信的类型--在前一种情况下是受纪律约束的，在后一种情况下是武断的。此外，在具有单独高速缓存的多处理器上实现共享变量系统会带来几个问题，包括高速缓存一致性。这项工作试图对共享变量编程施加某些规则，以便大规模系统设计变得可行，并且实现避免了与高速缓存一致性相关的大多数问题。研究计划是确定一大类共享变量系统，它们享有分布式(即消息传递)系统的一些优势。这些系统将被限制在一个称为松散耦合的类，在这个类中，不同进程的计算在很大程度上是不干扰的，即使它们共享变量。松散耦合的系统将获得通常与分布式系统相关联的某些属性--例如，不存在“竞争条件”。松散耦合系统的设计将在不对基于执行序列、进程交互或死锁的场景进行广泛分析的情况下完成。将发展这种系统的组合证明理论，并指出这种系统在多存储器多处理器体系结构上的有效实现。