A Distributed Object-Oriented Graphical Programming System

This report presents the design of a distributed parallel object system (DPOS) and its implementation using a graphical editing interface. DPOS brings together concepts of object-oriented programming and graphical programming with aspects of modern functional lan guages. Programs are defined as networks of active processes called “Process Objects ” and interconnecting communications lines. These active objects are independent single threaded programs that employ much of the modularity, encapsulation of function, and encapsulation of data found in sequential object-oriented programming. The system defines a clear and simple approach to generating and managing parallelism and interprocess communication in a distributed parallel environment. DPOS contributes several new solutions to the prob lems of distributed parallel programming that are improvements over existing systems. The key improvements of this system include: a more complete and versatile means of dynamic process creation; the specification of complex network topologies in an intuitively clear and understandable way; seperation of the management of parallelism from the definition of com putation; automatic resolution of low level critical section issues; the ability to design an