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Threads as an execution model are well understood by programmers. Nemesis' underlying activation model of execution was provided to enable application domains to control their own scheduling; however, it has the side effect of providing an environment in which it is possible to use a purely event driven execution model. To facilitate implementation of a system that conforms to such a model, a event toolkit will be built which isolates programmers from the synchronisation problems inherent in this model.

Pegasus-related research has demonstrated the feasibility of a ``client renders'' windowing system. Such a system aids resource accounting, removes the bottleneck of a shared window server process and provides tidy integration of video and conventional graphics. Pegasus II will provide a working prototype windowing system, to be accessible via a toolkit with a suitable high-level interface (e.g., in the spirit of Xlib and Motif).

Over this window system Pegasus II will provide the user interface to enable users to easily control the resource management policy being enforced by the operating system, and the toolkit to enable applications to interact with this user-controlled resource manager.

Simon Crosby
Thu Nov 7 11:56:58 GMT 1996