Looking ahead in atomic actions with exception handling

An approach to introducing exception handling into object-oriented N is presented. A novel atomic action scheme is developed that does not impose any participant synchronisation on action exit. In order to use cooperative exception handling at the action level as the main fault tolerance mechanism, we develop a distributed protocol that finds, for any exception raised, an action containing all potentially erroneous information, aborts all of its nested actions, resolves multiple concurrent exceptions and involves all the action participants into cooperative handling of the resolved exception. In the scheme, no service messages are sent and no service synchronisation is introduced if there are no exceptions raised. This flexible scheme can be applied in a number of emerging areas in which entities of a different nature (including software tasks, people, plants, documents, organisations, etc.) participate in cooperative activities.