COMPENSATABLE ATOMIC OBJECTS IN OBJECT-ORIENTED OPERATING SYSTEMS.

This paper introduces the notion of compensatable atomic objects for object-oriented operating systems and discusses its effectiveness. First, we describe a concept of atomic object and address the limitations of the ordinary nested transaction and serializable transaction models by describing a 'travel agent' and a 'resource map' problem. We then define the compensatable object by using the notion of the abstract equivalence relations among possible object states. An object model, called 'arobject', is also explained as a vehicle for compensatable objects in an object-oriented paradigm using a new type of transaction, called 'compound' transaction. Finally, the effective use of such compensatable objects is demonstrated by showing a few examples in an operating system context.