Abstract: Data may be manipulated directly in an object oriented programming system by providing a slot object which contains data within its frame. In contrast with conventional objects, the frames of which only contain attributes of the associated instances, the slot object contains actual data therein. Since this data is not contained in a separate object, a unique object identified need not be provided, thus simplifying object management. Unique messages also need not be provided so that message overhead is simplified. Memory fragmentation is also reduced because simple and tightly bound data may be encapsulated within a larger slot object. The data area in the slot object may be of fixed or variable size.

Abstract: A Unit of Work object class for an object oriented database management system provides concurrent processing through Unit of Work levels and instances while maintaining the integrity of the data in the database. Each new Unit of Work assigned to a task is an instance of the Unit of Work object class. A Unit of Work manager controls each step such that manipulation of the data occurs to the copies at that particular level for that particular instance. Only after all levels have been completed satisfactorily will a "Commit" occur to the data in the database. If completion is not satisfactory, Rollback of the levels occur, thus preserving data integrity. The Unit of Work manager can also switch control between Unit of Work instances, thus permitting simultaneous performance of tasks.

Abstract: A data structure and method for uniquely identifying, and optimizing access to, object instances in an object oriented programming environment on a data processor containing a memory. Objects are categorized into one or more classes which define the method of the categorized objects, and messages are sent by the data processor to objects to perform actions. The data structure consists of a persistent portion containing a unique object identifier and a non-persistent portion containing the access address of an instance data frame in memory. The access address is set to the address of the instance data frame control block when the message is sent in order to optimize subsequent messages to the same object instance. The instance data frame control blocks are not allocated in memory until a first message is sent to an instance.

Abstract: A system for implementing a messenger and object manager in an object oriented programming environment on a data processor containing a memory, in which objects are categorized into one or more classes which define methods of the objects categorized therein, and in which messages are sent by the data processor to objects to perform actions thereon. The system includes a message call processing procedure operating on the data processor for processing message calls to instances, including a method resolution segment for calling a loaded classes table to determine whether the class corresponding to a method of the instance is loaded, where the method corresponds to the action requested by the message. If the corresponding class is not loaded in main memory, then the system dynamically loads the class. A data resolution segment calls an object management table to resolve an indirection pointer which points to the address of a data frame corresponding to the instance.

Abstract: A persistent data interface for an object oriented programming system provides a persistent class object. Any object which must survive a run time session is arranged to inherit from the persistent class object. Any object which inherits from the persistent class automatically becomes a persistent object. The persistent class includes a "materialize" method for automatically retrieving a persistent object from nonvolatile memory and placing it in volatile memory if the persistent object cannot be located in volatile memory. A "dematerialize" method is also included for removing an object from volatile memory and storing it in nonvolatile memory. Data integrity of the system is thereby preserved.