Controlling (virtual) multicomputers

A multicomputer is a number of interconnected heterogeneous computing systems being used as a single computing system. To factor out the actual number and kinds of the resources available in any one (physical) multicomputer we propose the virtual multicomputer in which an abstract archetype of each kind (workstation, shared-memory multiprocessor, distributed-memory multiprocessor, array processor) can be instantiated at will. In turn, this raises the issues of how to control such a machine and, a fortiori, how to communicate within such a machine. While these problems can readily be solved in each program by using low-level techniques, it seems desirable to search for higher level abstractions which capture patterns of communication and control in concurrent programs in an architecture-independent manner. We outline some steps in this direction based on the use of EuLisp and its object system in a distributed environment