Abstract

This paper describes Omniware, a system for producing and executing mobile code. Next generation Web applications will use mobile code to specify dynamic behavior in Web pages, implement new Web protocols and data formats, and dynamically distribute computation between servers and browsers. Like all mobile code systems, Omniware provides portability and safety. The same compiled Omniware module can be executed transparently on different machines, and a module's access to host resources can be precisely controlled. In addition to portability and safety, Omniware has two unique features. First, Omniware is open. Omniware uses software fault isolation (SFI) to enforce safe execution of standard programming languages, enabling Web developers to leverage the vast store of existing software and programming expertise. For example, Omniware developers can use C++ to create programs for Web pages. Second, Omniware is fast. We evaluated Omniware under the Solaris 2.4 operating system on a SPARCstation 5 using eight C benchmark programs, including five programs from the C SPEC92 benchmark suite. We evaluated the performance of Omniware in two ways. First, we showed that Omniware modules can be represented compactly, reducing the space consumption compared to SunPro cc shared object files by an average of 38%. Second, we showed that Omniware modules execute at near native speeds. Including the runtime overhead necessary to ensure that Omniware modules are both portable and safe, our benchmark programs ran within 6% of native performance.

Citations