Low overhead object adaptor

摘要

Data structures and various methods for invoking and creating objects are used in a distributed object system in order to implement subcontracts. A subcontract is a selected grouping of basic features or object mechanisms that a system provides for use in managing objects and has associated functions. A subcontract registry is used for creating object references for server objects. The subcontract registry has any number of subcontract objects within it, and each subcontract object may include: a subcontract identifier that identifies the subcontract object, a quality of service list that contains feature name-value pairs, and a create function unique to the subcontract object. An implementation registry is used for registering any number of implementation definitions. Each implementation definition defines an implementation for an interface within the system, and each implementation definition may include: an implementation identifier that identifies the implementation, a pointer to a subcontract object contained in the subcontract registry, an interface identifier that identifies the interface being implemented, and a set of functions used for creating and invoking a server object that are unique to that implementation. One method creates an object reference for a distributed server object by using the subcontract registry in order to identify the unique create function to be used that corresponds to the subcontract functionality desired. Another technique invokes a method defined on a server object by using an object reference to find the appropriate implementation definition in the implementation registry. Lookup and dispatch functions unique to this definition are used to invoke the method.