A simulation framework for concurrent object execution

The paper reports on an investigation into the requirements and development of a simulation framework and associated visualisation concerns for a concurrent object oriented programming model. The main focus has been the simulation of active objects, their communication interaction, the physical environment they run on (multiple processors) and the visualisation of the execution and interaction. The framework system has been designed using object oriented methods, and implemented in Visual C++ using the MFC running under Windows 3.1x. The model includes dynamic objects, broadcast communications and grouping. All objects belong to a group, and can move dynamically between groups. Groups are a collection of objects where each object is instructed to recognise both arbitrarily broadcast messages, but also messages pertaining to their specific group. Further flexibility is gained by allowing groups to overlap, with a particular object belonging to more than one group. When executing on a parallel system, groups (and objects) are related to a particular processor. A processor can hold more than one group, and a group can reside on more than one processor. Environments where processors can dynamically move in and out of the available processing pool are considered