Multiple concurrency control policies in an object-oriented programming system

Object-oriented systems have been generally recognized as a good choice for approaching a range of parallel and distributed programming problems. But different parallel and distributed applications have different consistency models, so multiple concurrency control policies are needed. When objects are shared among applications with different policies, multiple policies must operate simultaneously and compatibly. We have investigated two consistency models, critical sections on individual objects and classical serializable transactions, and the interactions both between these models and with “uncontrolled” concurrency, in the context of the MELD distributed object-oriented programming language. We present the relevant language constructs and discuss programming problems and implementation issues.