Highly responsive implementation of the BTRON2 window system

The authors describe the implementation mechanism of a window system for BTRON2 is an operating system that realizes advanced human-machine interfaces (HMIs). The include groupwares, gestures, assistive technology, post-it metaphor, and so on. The main purpose is to clarify mechanisms for highly-responsive implementation of the BRON2 window system. To increase its responsiveness, the authors propose adopting the following mechanisms: an R-tree for the data structure of a set of interaction objects in a window, fully-replaced data approach when sharing a window among multiple users on different machines, implementation with multiple concurrent tasks sharing the same data structures, priority-based real-time scheduling among these tasks. The authors describe the result of performance evaluations on the prototype system implemented using these mechanisms.