Software architectures for reducing priority inversion and non-determinism in real-time object request brokers

Abstract

There is increasing demand to extend Object Request Broker (ORB) middleware to support distributed applications with stringent real-time requirements. However, conventional ORB implementations, such as CORBA ORBs, exhibit substantial priority inversion and non-determinism, which makes them unsuitable for applications with deterministic real-time requirements. This paper provides two contributions to the study and design of real-time ORB middleware. First, it illustrates empirically why conventional ORBs do not yet support real-time quality of service. Second, it evaluates connection and concurrency software architectures to identify strategies that reduce priority inversion and non-determinism in real-time CORBA ORBs. The results presented in this paper demonstrate the feasibility of using standard OO middleware like CORBA to support certain types of real-time applications over the Internet.