Anup Rao

A technique for dynamic updating of Java software

During maintenance, systems are updated to correct faults, improve functionality, and adapt the software to changes in its execution environment. The typical software update process consists of stopping the system to be updated, performing the update of the code, and restarting the system. For systems such as banking and telecommunication software, however the cost of downtime can be prohibitive. The situation is even worse for systems such as air-traffic controllers and life-support software, for which a shut-down is in general not an option. In those cases, the use of some form of on-the-fly program modification is required. In this paper, we present a new technique for dynamic updating of Java software. Our technique is based oil the use of proxy classes and requires no support from the runtime system. The technique allows for updating a running Java program by substituting, adding, and deleting classes. We also present DUSC (dynamic updating through swapping of classes), a tool that we developed and that implements our technique. Finally, we describe an empirical study that we performed to validate the technique of a real Java subject. The results of the study show that our technique can be effectively applied to Java software with only little overhead in both execution time and program size.

How to Compress Interactive Communication

We describe new ways to simulate two-party communication protocols to get protocols with potentially less communication. We show that every communication protocol that communicates

How to compress interactive communication

C

Information Equals Amortized Communication

bits and reveals

Extractors for a constant number of polynomially small min-entropy independent sources

I

Towards coding for maximum errors in interactive communication

bits of information about the inputs to the participating parties can be simulated by a new protocol involving at most

Deterministic extractors for small-space sources

\tilde{O}(\sqrt{CI})

Extractors for Low-Weight Affine Sources

bits of communication. If the protocol reveals

Direct Products in Communication Complexity

I

2-Source Extractors under Computational Assumptions and Cryptography with Defective Randomness

bits of information about the inputs to an observer that watches the communication in the protocol, we show how to carry out the simulation with