Communication primitives supporting the execution of atomic actions at remote sites

A request manager is described that provides a set of communication primitives supporting the cooperation between processes requesting service and processes providing service. These communication primitives allow the initiation and termination of atomic actions at remote sites. They also maintain recoverable action state tables, which can be used to recall uncompleted actions during restart recovery. The presented request manager is a good foundation on which to develop application oriented high-level primitives as well as language level primitives. Besides a detailed description of the services offered by the request manager, the paper develops a request management protocol that, no matter what happens, insures the atomic property of actions. Evaluation nets, which are a modified form of Petri nets, are applied to describe this protocol.