Enhancing O-O Middleware to Become Time-Aware

The general trend in middleware moves towards object-orientation. Implementation hiding, inheritance, and polymorphism are concepts, that have turned out to be well suited for the structuring of new complex distributed applications as well as for the integration of legacy systems. The existence of CORBA as a vendor-independent standard for object-oriented middleware has added another momentum to this development. Regarding real-time requirement, however, there exists an obvious trade-off. While implementation hiding isolates module implementations and eases their integration as it allows to simply match interfaces, it ignores the fact that in the real-time domain implementation does matter. To solve this problem, we need a system that is capable to adapt in a predictable manner to dynamic, unpredictable changes in its environment. In this paper we present our approach for an adaptive real-time system. It provides a run-time support system comprising run-time monitoring and on-line, fault-tolerant scheduling as its key components. It can be used to enhance emerging object-oriented de facto standards like CORBA with adequate features to integrate them as "time-aware'' components.