Method and system for aggregating objects

A method in a computer system of reference counting for an enclosing object and an enclosed object, the enclosing object having a reference count, the enclosing object having an add reference function member and a release reference function member, the enclosed object having an add reference function member and a release reference function member, the enclosing object having an implementation of an object management interface, the enclosed object having an implementation of an external interface, wherein the add reference function member of the enclosing object is part of the object management interface implementation, wherein the add reference function member of the enclosed object is part of the external interface implementation, the method comprising the steps of:

• under control of the add reference function member of the enclosed object, invoking the add reference function member of the enclosing object, wherein the add reference function member of the enclosing object increments the reference count, and wherein the external interface implementation of the enclosed object invokes the object management interface implementation of the enclosing object to increment the reference count;
• and
• under control of the release reference function member of the enclosed object, invoking the release reference function member of the enclosing object, wherein the release reference function member of the enclosing object decrements the reference count.

A method in a computer system of reference counting for an enclosing object and an enclosed object, the enclosing object having a reference count, the enclosing object having an add reference function member and a release reference function member, the enclosed object having an add reference function member and a release reference function member, the enclosing object having an implementation of an object management interface, the enclosed object having an implementation of an external interface, wherein the release reference function member of the enclosing object is part of the object management interface implementation, wherein the release reference function member of the enclosed object is part of the external interface implementation, the method comprising the steps of:

• under control of the add reference function member of the enclosed object, invoking the add reference function member of the enclosing object, wherein the add reference function member of the enclosing object increments the reference count;
• and
• under control of the release reference function member of the enclosed object, invoking the release reference function member of the enclosing object, wherein the release reference function member of the enclosing object decrements the reference count and wherein the external interface implementation of the enclosed object invokes the object management interface implementation of the enclosing object to decrement the reference count.

A method in a computer system of reference counting for an enclosed object aggregated within an enclosing object, the enclosed object having an object management interface and an external interface, the enclosing object having a controlling object management interface, each interface having a query function member for receiving an identifier of an interface and for returning a reference to the identified interface, the controlling object management interface having an add reference function member and a release reference function member for maintaining a reference count, the method comprising the steps of:

• creating an instance of the enclosing object;
• creating an instance of the enclosed object;
• upon executing the query function member of the controlling object management interface of the instantiated enclosing object,
• receiving an identifier of the external interface of the instantiated enclosed object;
• invoking the add reference function member of the controlling object management interface to increment the reference count;
• and
• returning a reference to the external interface;
• and
• upon executing the query function member of the external interface of the instantiated enclosed object,
• receiving an identifier of an interface;
• invoking the query function member of the controlling object management interface of the instantiated enclosing object passing the received identifier;
• and
• returning a reference returned by the invoked query function member of the controlling object management interface of the instantiated enclosing object as a reference to the identified interface.

A method in a computer system of implementing a class defining an aggregatable object, the class having an object management interface and an external interface, the object management interface and external interface having an add reference function member for providing reference counting, the method comprising the steps of:

• generating a create instance function member for instantiating an object of the class, wherein the create instance function member stores in a data member of the class a reference to the object management interface of the class when the object is not aggregated and stores in the data member of the class a reference to a controlling object management interface of an enclosing object when the object is aggregated, the controlling object management interface having an add reference function member;
• generating an add reference function member of the object management interface, the add reference function member for incrementing a local reference count of the object;
• and
• generating an add reference function member of the external interface, the add reference function member for invoking the add reference function member of the object management interface referenced by the data member.

A method in a computer system of creating an aggregate object, the aggregate object having an enclosed object, the enclosed object having an external interface that is exposed by the aggregate object, the method comprising the steps of:

• instantiating the aggregate object, the aggregate object having a query function member for retrieving references to interfaces exposed by the aggregate object and having an add reference counting function member and a release reference counting function member for maintaining a count of references to the aggregate object;
• instantiating the enclosed object, the enclosed object having a query function member of the external interface for retrieving references to interfaces exposed by the aggregate object;
• storing a reference to the enclosed object, wherein the query function member of the aggregate object uses the stored reference to the enclosed object to retrieve a reference to the exposed external interface and wherein the release reference counting function member uses the stored reference to the enclosed object to delete the enclosed object when no references to the aggregate object exist;
• and
• storing a reference to the aggregate object, wherein the query function member of the external interface uses the stored reference to the aggregate object to invoke the add reference counting function member of the aggregate object to increment the count of references to the aggregate object when returning a reference to the exposed external interface.

A method in a computer system of enclosing an enclosed object within an enclosing object, the enclosing object having a query function member, the enclosed object having a query function member, the query function members for retrieving references to interfaces exposed by the enclosing object, the enclosed object having an external interface that is exposed by the enclosing object, the method comprising the steps of:

• instantiating the enclosing object;
• instantiating the enclosed object;
• storing a reference to the instantiated enclosed object within the instantiated enclosing object;
• and
• when executing the query function member of the instantiated enclosing object, using the stored reference to the instantiated enclosed object, invoking the query function member of the instantiated enclosed object to retrieve a reference to the exposed external interface of the instantiated enclosed object.

A method in a computer system of enclosing an enclosed object within an enclosing object, the enclosing object having an query function member, the enclosed object having an query function member, the query function members for retrieving references to interfaces exposed by the enclosing object, the enclosed object having an external interface that is exposed by the enclosing object, the method comprising the steps of:

• instantiating the enclosing object;
• instantiating the enclosed object;
• storing a reference to the instantiated enclosing object within the instantiated enclosed object;
• and
• when executing the query function member of the instantiated enclosed object, using the stored reference to the instantiated enclosing object, invoking the query function member of the instantiated enclosing object to retrieve a reference to an exposed interface of the instantiated enclosing object.

A method in a computer system of implementing a class that specifies an aggregatable object, the class having an object management interface and an external interface, the object management interface and the external interface having add reference function members for providing reference counting and query function members for providing access to the interfaces of the aggregatable object, the method comprising the steps of:

• declaring the external interface;
• and
• declaring the aggregatable class, the aggregatable class inheriting the declared external interface as a base class, the aggregatable class having an implementation of the add reference and query function members of the declared external interface,
• wherein the add reference function member of the declared external interface invokes the add reference function member of the object management interface when the object is not aggregated and invokes an add reference function member of an aggregating object when the aggregatable object is aggregated, and
• wherein the query function member of the declared external interface invokes the query function member of the object management interface when the object is not aggregated and invokes a query function member of an aggregating object when the aggregatable object is aggregated.

A computer-readable memory device that contains instructions for controlling a computer system to enclose an enclosed object within an enclosing object, the enclosing object having a query function member, the enclosed object having a query function member, the query function members for retrieving references to interfaces exposed by the enclosing object, the enclosed object having an external interface that is exposed by the enclosing object, by performing the steps of:

• instantiating the enclosing object;
• instantiating the enclosed object;
• storing a reference to the instantiated enclosed object within the instantiated enclosing object;
• and
• when executing the query function member of the instantiated enclosing object, using the stored reference to the instantiated enclosed object, invoking the query function member of the instantiated enclosed object to retrieve a reference to the exposed external interface of the instantiated enclosed object.

A computer-readable memory device that contains:

• a definition of an external interface of an aggregatable object having an add reference function member and a release reference function member;
• and
• a definition of an object management interface of the aggregatable object having an add reference function member and a release reference function member for providing reference counting
• a definition of an aggregatable class, the aggregatable class inheriting the defined external interface as a base class, the aggregatable class having an implementation of the add reference and release reference function members of the defined external interface,
• wherein the add reference function member of the defined external interface invokes the add reference function member of the object management interface when the object is not aggregated and invokes an add reference function member of an aggregating object when the aggregatable object is aggregated, and
• wherein the release reference function member of the defined external interface invokes the release reference function member of the object management interface when the object is not aggregated and invokes a release reference function member of an aggregating object when the aggregatable object is aggregated.