Achieving target-system independence in event visualisation

A process-time diagram showing the execution history of individual processes and the interactions between processes can be a very useful tool in understanding the behaviour of a distributed or concurrent application. Because of the variety of environments for writing distributed and concurrent applications, a tool that produces such diagrams is most useful if it is not tied to a particular environment. This paper [1] describes techniques that can be used to obtain such target-environment independence. Because target environments can differ in their conceptual model of process interactions, e.g., message passing versus remote-method invocation, it is important to provide a very general structure for such specifications, making as few assumptions as possible about characteristics that must be possessed by all target environments. By making reference to our experience with the implementation of the Partial-Order Event Tracer, we will suggest principles for effectively using table-driven implementations and appropriate means for dealing with odd situations that cannot reasonably be coded into a table or control file. We claim that appropriate use of such techniques need not compromise execution effciency, relative to a tool designed for only one environment, and also allows easy implementation for a new target environment.