OBJECT-BASED SUBCONTRACTING FOR PARALLEL PROGRAMMING ON LOOSELY-COUPLED DISTRIBUTED SYSTEMS

Several languages have been proposed to support concurrency in object- oriented programming. However, these languages do not address issues w hich are specific to parallel programming on loosely coupled distribut ed systems such as dynamic load variation, fault tolerance and scalabi lity. We propose a new paradigm called object-based subcontracting for parallel programming on loosely-coupled distributed systems. In this paradigm, a metaclass called Parclass is defined to create a metaobjec t. The metaobject aggregates objects belonging to a class. A member fu nction of the class, which can be executed concurrently on all the obj ects, is invoked as a subcontract on the metaobject. The metaobject ma nages the subcontract by employing various nodes of the network. The s ubcontract invocation is made fault tolerant and scalable.