Accession Number : ADA555874
Title : Confluence Analysis for Distributed Programs: A Model-Theoretic Approach
Descriptive Note : Technical rept.
Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
Personal Author(s) : Marczak, William R ; Alvaro, Peter ; Conway, Neil ; Hellerstein, Joseph M ; Maier, David
Report Date : 18 Dec 2011
Pagination or Media Count : 15
Abstract : Building on recent interest in distributed logic programming, we take a model-theoretic approach to analyzing confluence of asynchronous distributed programs. We begin with a model-theoretic semantics for Dedalus and develop the concept of ultimate models to capture the non-deterministic eventual outcomes of distributed programs. After demonstrating the undecidability of checking confluence for Dedalus programs, we look for restricted sub-languages that guarantee confluence while providing adequate expressivity. We observe that a simple semipositive restriction called Dedalus+ guarantees confluence while capturing PTIME, but demonstrate that the limited use of negation in Dedalus+ makes certain simple and practical programs very difficult to express. To remedy this, we introduce DedalusS , a restriction of Dedalus that allows a natural use of negation in the spirit of stratified negation, but retains the confluence of Dedalus+ and similarly captures PTIME.
Descriptors : *COMPUTER PROGRAMMING , *DISTRIBUTED COMPUTING , CONFLUENCE , PROGRAMMING LANGUAGES , SEMANTICS
Subject Categories : Computer Programming and Software
Distribution Statement : APPROVED FOR PUBLIC RELEASE