The University of Arizona, Department of Computer Science

Joust

Overview

Joust is a small, fast JavaOS implemented in Scout. It includes an efficient Java virtual machine (including the AWT windowing toolkit) and a Java JIT compiler. We are exploring how Java's various features interact with Scout's modual approach to building systems.

Research Goals

• Safety. While one of the stated goals of Java is a secure network environment, Java provides no formal security model. We plan on integrating Java into Scout's path-based security model to provide greater assurance of security from malicious applets.
• Active Networks. We are exploring how Scout's paths can be integrated into (and exploited by) Java applications. For example, adding Scout's pathCreate operation to the Java API allows Java applications to create paths that exist entirely outside the Java VM. These paths can be scheduled according to realtime constraints without interference from Java garbage collection. In general, we are investigating the use of Joust, with path extensions, as the node OS for active networks.

Router Graph

Status

• The implementation of the Java JIT compiler, done as part of the Sumatra project, is complete.
• The port of the Toba runtime to Scout is complete, providing AWT, network, garbage collection, and file system services to Joust applications.
• We have integrated and measured the ANTS active network environment in Joust.

Papers

[Hart97] John Hartman, Larry Peterson, Andy Bavier, Peter Bigot, Patrick Bridges, Brady Montz, Rob Piltz, Todd Proebsting, and Oliver Spatscheck. Joust: A Platform for Communications-Oriented Liquid Software. Technical Report TR97-16, Department of Computer Science, University of Arizona (November 1997).

Contributors

• Patrick Bridges, Graduate Student
• Andy Bavier, Research Staff
• Peter Bigot, Research Staff
• Rob Piltz, Research Staff