A parlog based real-time distributed logic environment

Abstract

The high complexity of distributed computer systems requires new programming languages and tools which will avoid many of the details that are necessary to take into account with the traditional languages. The new proposals of declarative languages and the advances in compilation techniques will make these languages an alternative to imperative languages in some areas. We propose a real-time distributed environment based on a concurrent logic language. With this approach we try to provide the advantages of a declarative language to real-time distributed system. Because of the interactive features of the distributed systems, these cannot be distributed systems, these cannot be described in usual logical or functional terms and it is necessary to use reactive languages. There is a class of logic languages with a reactive behaviour named Concurrent Logic Languages which are well suited for this kind of problem. We have extended one of these languages (Parlog) with real-time and communications primitives, and we have developed a distributed environment which can create and control remote processes in a very easy and efficient way. The remote execution of processes is based on a remote metacall that we have developed. A prototype of the environment has been implemented using metainterpretation. The real-time extension includes the definition of real-time primitives and the modification of the execution model of Concurrent Logic Languages. We give a new operational semantics for the extended language. We also describe a tool for translating extended state machine specifications to the environment. This will allow the creation of executable prototypes on distributed computer systems and the validation of complex system specifications in an easy way.