TC: Medium: Collaborative Research: Rewriting Logic Foundations for Verification and Programming of Next-Generation Trustworthy Web-Based Systems

分布式并发模型（Distributed Concurrent Maude, DCMaude）计算重写模型简单，但具有通用性和灵活性。任何类型的系统，例如算法、数据库、硬件系统、编程语言、网络协议、传感器网络或细胞的分子生物学动力学，都可以通过一组描述系统行为的重写规则来建模。计算的重写模型本质上是并发的，不需要显式的并发构造。应用于非重叠系统组件的任何规则集都可以并发执行。对于大型分布式系统（如网络或单元），这意味着在任何给定的时间，都可能有数千或数百万个并发转换并行发生。Maude是一种基于重写逻辑的语言。当前的Maude实现提供了一个高性能的重写引擎，以及内置的搜索、统一和模型检查工具，以支持Maude中指定的系统的执行和分析。为了实现重写的固有并发性，提议的项目将开发一种称为分布式和并发Maude （DCMaude）的Maude实现，该实现将利用多核/多处理器机器中的并发性，并支持分布式计算和系统编程。Maude的重写语义支持系统并发执行和分布式执行之间的无缝转换：在一个进程、多个进程/核心或多台机器中执行。除了内置的并发策略外，DCMaude的设计还将包括一种方法，使程序员能够以声明的方式在高层次的抽象上控制并发性。DC Maude将提供新的方法和工具，可以显著改善开放式分布式系统的设计和实现，包括基于web的系统和下一代网络。

Distributed Concurrent Maude ( DCMaude ) The rewriting model of computation is simple , yet general and flexible . A system of any kind , for example , an algorithm , a database , a hardware system , a programming language , a network protocol , a sensor network , or the molecular biology dynamics of a cell , can be modeled by a set of rewrite rules that describe the systems behavior . The rewriting model of computation is intrinsically concurrent , without any need for explicit concurrency constructs . Any set of rules that apply to nonoverlapping system components can execute concurrently . For a large distributed system such as a network or a cell , this means that at any given time thousands or millions of concurrent transitions may be happening in parallel . Maude is a language based on rewriting logic . The current Maude implementation provides a high performance rewrite engine , as well as builtin search , unification , and model checking tools to support execution and analysis of systems specified in Maude . To realize inherent concurrency of rewriting , the proposed project will develop an implementation of Maude called Distributed and Concurrent Maude ( DCMaude ) that will exploit the concurrency available in multicore/multiprocessor machines , and support distributed computing and systems programming . The rewriting semantics of Maude supports seamless transition between concurrent and distributed execution of a system : execution in one process , multiple processes/cores , or multiple machines . In addition to built in strategies for concurrency , the design of DCMaude will include a means for the programmer to control concurrency at a high level of abstraction in a declarative way . DC Maude will provide new methods and tools that can significantly improve both the design and the implementation of open distributed systems , including web-based systems and next-generation networks .