Stanford Digital Library Testbed Development Department of Computer Science Stanford University Stanford, CA

Common Object Services:

Common Object Services are objects or groups of objects that provide the basic requirements which most objects need in order to function in a distributed environment. These services are designed to be generic; they do not depend on the type of client object or type of data passed. Note: this is hard to do in ILU since there is no concept of the Object or Any type.

Overview of these COS services (postscript compressed) (powerpoint compressed) (webify-ed gifs)

Naming Service

Provides a way to reference an object independent of its location, type, or state.

Event Communication Services

Provides the basic capabilities of push and pull event delivery models. Allows for asynchronous events, event "fan-in", notification "fan-out", and event channels.

Event Channel Administration Services

Provides mechanisms for setting up and breaking event channel.

Life Cycle Services

Provides services for creating, deleting, copying, and moving objects in a distributed environment.

Object Property Service

Provides services for managing properties of an object.

Factory Service

Provides services for creating and managing objects in a distributed environment.