Is "Just in Time" = "Better Late than Never"?

Abstract

The World-Wide Web is emerging as a medium for distributing platform-independent, intermediate-form programs. Most Java vendors have recently announced plans to construct "just-in-time" systems, which translate the intermediate text into native code on demand. In this paper, we present experiments that show the benefits of just-in-time systems as compared with the traditional (compile prior to execution) systems. We introduce a new method--the continuous compiler-- that can outperform just-in-time systems by overlapping compilation with program interpretation and native execution. Based on those results, we then present a smart just-in-time system that blends interpretation with native-code execution, thereby obtaining improved performance.