Hybrid Java']Java Compilation and Optimization for Digital TV Software Platform

The Java software platform for the interactive digital TV (DTV) is composed of the system/middleware classes statically installed on the DTV set-top box and the xlet classes dynamically downloaded from the TV stations, where xlets are executed only when the TV viewer initiates the interaction. In order to achieve high performance on this dual-component, user-initiated system, existing just-in-time compilation is not enough, but idle-time compilation and optimization as well as ahead-of-time compilation are also needed, requiring a hybrid compilation and optimization environment. We constructed such a hybrid environment for a commercial DTV software platform and experimented with real, on-air xlet applications. Our experimental results show that the proposed hybrid environment can improve the DTV Java performance by as much as an average of 150%, compared to the JITC-only environment.