Overlapping Execution with Transfer Using Non-Strict Execution for Mobile Programs

Chandra Krintz, Brad Calder, Han Bok Lee, and Benjamin G. Zorn

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In order to execute a program on a remote computer, it must first be transferred over a network. This transmission incurs the overhead of network latency before execution can begin. This latency can vary greatly depending upon the size of the program, where it is located (e.g., on a local network or across the Internet), and the bandwidth available to retrieve the program. Existing technologies, like Java, require that a file be fully transferred before it can start executing. For large files and low bandwidth lines, this delay can be significant.

In this paper we propose and evaluate a non-strict form of mobile program execution. A mobile program is any program that is transferred to a different machine and executed. The goal of non-strict execution is to overlap execution with transfer, allowing the program to start executing as soon as possible. Non-strict execution allows a procedure in the program to start executing as soon as its code and data have transferred. To enable this technology, we examine several techniques for rearranging procedures and reorganizing the data inside Java class files. Our results show that non-strict execution decreases the initial transfer delay between 31% and 56% on average, with an average reduction in overall execution time between 25% and 40%.