In a system employing an object-oriented operating system, the invention improves
the performance in execution of the overall system while flexibility of the system
is maintained. A plurality of objects communicating messages among them are each
constituted by any of a composite object made up of one or more objects and a standard
object that is an object other than a composite object. An identifier is attached
to each of the standard object and the component objects so that each standard
object and each component object can be referenced from any object. For the composite
object, one composite object is executed by one execution thread, and the execution
thread is shared by each component object of the composite object.
