Methods and apparatus for managing collections of objects

A variety of methods, apparatus and data structures for managing collections of objects are described. In one aspect of the invention, an object that is intended for use in a distributed object operating environment has a structure including a group designation, a co-activation designation and a co-process designation. The group designation is arranged to identify a group to which the object belongs. The group is defined as a collection of objects which share a common persistent state. The co-activation designation is arranged to identify a co-activation set to which the object belongs. The co-activation set is a collection of objects which are to be activated at the same time. The co-process designation is arranged to identify a co-process set to which the object belongs. The co-process set is a collection of objects which are to be activated within a single process. A various embodiments, a variety of methods of utilizing one or more of these designations to facilitate efficient operation of a distributed computing system are also described. In some applications, a particular object may be conceptually divided into a plurality of sub-objects, with each sub-object having its own portion of persistent memory. In this embodiment, the particular object may only be invoked as a whole, but the object is provided with a mechanism for accessing the selected sub-object in response to a call from a client object that invokes the object and identifies the sub-object in a sub-object field of an object reference that refers to the object. When sub-objects are use, the object references may be arranged to include a host identifier, an object identifier and a sub-object field.