Wide-Area and Distributed Computation Paradigm Based on Concurrent Logic Programming

并发逻辑语言通过在单赋值变量上引入同步来提供描述并发计算的自然机制。并发逻辑编程的前期工作主要集中在高效的并行计算上。相比之下，我们的研究集中在分布式广域计算上，并研究了（1）非均匀计算环境下的声明式编程和（2）安全分布式程序的静态分析。我们的研究结果可以概括如下：1.无缝分布式实现-我们设计并实现了网络透明的分布式逻辑变量（单分配通道），以使用套接字透明地互连在非统一计算节点上运行的KL 1程序。设计了用于分布式逻辑变量命名和解析的命名服务。设计并实现了异常处理机制.分布式环境下的资源管理-我们设计并实现了一个线性类型的并发逻辑程序，静态分析数据共享的逻辑变量的系统。提出了一种基于资源传递的并发计算的新观点，并设计了一种统一和推广模式系统和线性系统的能力型系统.代码移动的解释器技术--我们设计了一个中间代码，称为树码，以实现非均匀节点之间的代码移动，并使用Flat GHC描述其解释器。

Concurrent logic languages provide natural mechanisms for describing concurrent computation by introducing dataflow synchronization on single-assignment variables. Previous work on concurrent logic programming focused on efficient parallel computation. Our research, in contrast, focused on distributed, wide-area computation and studied (1) declarative programming under non-uniform computational environments and (2) static analysis for safe distributed programs. Our results can be summarized as follows :1. Seamless distributed implementation - We designed and implemented network-transparent distributed logical variables (single-assignment channels) to transparently interconnect KL1 programs running on non-uniform computational nodes using sockets. We also designed naming service used for the naming and resolution of distributed logical variables. An exception handling mechanism was also designed and implemented.2. Resource management under distributed environments - We designed and implemented a linear type system for concurrent logic programs that statically analyzes data sharing by logical variables. Furthemore, we proposed a novel view of concurrent computation in terms of resource passing, and designed a capability type system that unifies and generalizes mode systems and linearity systems.3. Interpreter technology for code mobility - We designed an intermediate code, called treecode, to realize code mobility between non-uniform nodes, and described its interpreter using Flat GHC.