Technical Report: DCC-97-17

VisAll: A new Tool to Visualise the Parallel Execution of Logic Programs

Nuno Fonseca, Vítor Santos Costa and Inês de Castro Dutra

DCC-FC & LIACC and COPPE/Sistemas
Universidade do Porto and Universidade Federal do Rio de Janeiro

December 1997

Abstract

One of the most important advantages of logic programming systems is that they allow the transparent exploitation of parallelism. The different forms of parallelism available and the complex nature of logic programming applications present interesting problems to both the users and the developers of these systems. Graphical visualisation tools can give a particularly important contribution, as they are easier to understand than text based tools, and allow both for a general overview of an execution and for focusing on its important details.

Towards these goals, we propose VisAll, a new tool to visualise the parallel execution of logic programs. VisAll benefits from a modular design centered in a graph that represents a parallel execution. A main graphical shell commands the different modules and presents VisAll as an unified system. Several input components, or translators, support the well-known VisAndor and VACE trace formats, plus a new format designed for independent and-parallel plus or-parallel execution in the SBA. Several output components, or visualisers, allow for different visualisations of the same execution. These visualisaters can operate simultaneously and can collaborate by using the execution graph.

Keywords: logic programming, parallelism, visualisation tool.