Abstract: The present invention provides a novel method and apparatus for performing real-time computer garbage collection, in a manner that offers unprecedented low bounds on the worst-case frequency and duration of the collection task. The invention is used with a plurality of data objects and with one or more mutator programs. The mutators and a garbage collector run on one or more processors. The mutators each have a corresponding thread with a corresponding thread state. In the present invention, execution of all mutators is temporarily restricted at the start of each new garbage collection cycle. However, unrestricted execution of a mutator is quickly resumed, as soon as that mutator's thread state is processed. The remainder of the garbage collection cycle may be performed concurrently with the mutators.

Abstract: System resources are automatically assigned by a single resource conflict resolver to all functions on expansion buses in a computer system. Such system resources include, but are not limited to, memory ranges, input-output (I/O) register ranges, interrupt request lines and direct memory access (DMA) channels. Generally, the assignment is exclusive, however, in some cases, the assignment may be shared so that one or more resources will be shared between different functions. In order to prevent contention between two functions for the same resource, classes are provided which classes can be instantiated to construct resource lock objects. The resource lock objects provide an access control mechanism to synchronize access to the resources among the devices that use and, possibly, share the resources. The lock object contains methods which retrieve the resource assignments for an I/O function and acquire a lock on the resources.

Abstract: The present invention provides a novel method and apparatus for performing real-time computer garbage collection, in a manner that offers unprecedented low bounds on the worst-case frequency and duration of the collection task. The invention is used with a plurality of data objects and with one or more mutator programs. The mutators and a garbage collector run on one or more processors. The mutators each have a corresponding thread with a corresponding thread state. In the present invention, execution of all mutators is temporarily restricted at the start of each new garbage collection cycle. However, unrestricted execution of a mutator is quickly resumed, as soon as that mutator's thread state is processed. The remainder of the garbage collection cycle may be performed concurrently with the mutators.

Abstract: An apparatus for enabling an object-oriented application to access in an object-oriented manner a procedural operating system having a native procedural interface is disclosed. The apparatus includes a computer and a memory component in the computer. A code library is stored in the memory component. The code library includes computer program logic implementing an object-oriented class library. The object-oriented class library comprises related object-oriented classes for enabling the application to access in an object-oriented manner services provided by the operating system. The object-oriented classes include methods for accessing the operating system services using procedural function calls compatible with the native procedural interface of the operating system. The computer processes object-oriented statements contained in the application and defined by the class library by executing methods from the class library corresponding to the object-oriented statements.

Abstract: A computer system has a processor, a display, and a object-oriented application interface between a user input device such as a cursor placement device and an object-oriented application program. The cursor placement device has a user button for generating a device event signal for controlling a pointer graphic on the display. The object-oriented application program includes a plurality of objects with logic and data for performing particular functions. An interactor object is responsive to a device event signal to change the display from displaying an icon to a thumbnail display. An interactable object is instantiated in an application address space, and includes data and methods for manipulating the data. The interactor object is instantiated in a system address space and is responsive to the device event signal for calling a predetermined one of the interactable object's methods to change the data therein.

Abstract: A flexible system for changing the physical manifestation of an object in an object-oriented computer environment. An object to be manifested, denominated a "costume" object, is associated with a target object having a corresponding physical appearance. The costume object accepts a physical manifestation request and responds by transmitting to the target object a message requesting that the target object manifest itself. The target manifestation request message includes parameter values specifying the on-screen location and other properties of the costume object. In this fashion, the costume object can present itself wearing the appearance or "costume" of the target object.

Abstract: On a multi-node client server network, a client node obtains access to remote services by means of a communications directory service located in each node of the network. The communications directory service includes a tree structure to which existing directory services and other network services can be added. The tree structure has a plurality of nodes each of which includes specific methods that query and browse the associated directory service if such actions are supported by the underlying service. The communications directory service further includes shared libraries which store a service object associated with each service offered on the network. The service object, in turn, includes the service exchange address and communication link configuration information. A client desiring to access a remote service retrieves the appropriate service object from the communications directory service and uses the service object to set up the communications path.

Abstract: A graphics system enables an automatic choice between existing host rendering programs, existing hardware acceleration methods, and enhanced software acceleration programs for rendering graphic primitives. The graphics system accesses the speed and accuracy characterizations of a hardware accelerator attached to the system. Then, for each graphics primitive available from the enhanced software acceleration programs, the graphics system invention compares the speed and accuracy of the attached hardware accelerator with that of the enhanced software acceleration programs. The graphics system invention then selects which graphics primitives should be rendered by the enhanced software acceleration programs and which graphics primitives should be rendered by the attached hardware accelerator.

Abstract: A system for connecting a video object to various multimedia objects to enable an object-oriented simulation of a multimedia presentation using a computer with a storage and a display. A plurality of multimedia objects are created on the display including at least one connection object and at least one video object in the storage. Multimedia objects are displayed on the display, including at least one video object. The multimedia object and the video object are connected, and information is routed via the connection between the multimedia object and the video object to create a multimedia presentation.

Abstract: A flexible system for changing the physical manifestation of an object in an object-oriented computer environment is provided. The object to be manifested (a "costume" object) is associated with a target object having a corresponding physical appearance. The costume object responds to requests that it physically manifest itself by transmitting a message to the target object requesting that the target object manifest itself, but also including parameter values describing the costume objects on-screen location or similar properties. In this manner, a costume object is capable of presenting itself wearing the target object's "costume" or appearance.

Abstract: A system and method provide a cursor tool framework and tool server with support for multiple cursors on any given system, and supports the selection of a cursor tool utilizing a cursor. The framework and server facilitate the association of cursor tools to a cursor in a process independent space such that tools can be used cross-process and cross-document. The framework also provides default functionality for communication among cursor tools and the canvas on which they are used. This high degree of interaction allows any cursor tool and any document to function together such that the cursor tool can be written without the knowledge of the document developer.

Abstract: A method for rendering two-dimensional shapes and two-dimensional projections of three-dimensional shapes on a projection plane uses a sorting table to determine which shapes overlap other shapes. For each two-dimensional shape, the shorting table includes an order attribute specifying the front to back ordering of the two-dimensional shapes on the projection plane. For each three-dimensional shape the sorting table includes a Z-value specifying a position along a coordinate perpendicular to the projection plane. The position specified is dependent on whether the three-dimensional shape is perceived to be in front of the projection plane or behind the projection plane. The values in the sorting table are sorted to produce a composite ordering of the shapes and a drawing is created by sequentially rendering each shape in the composite order of the sorting table to depict an overlapped appearance of the shapes.

Abstract: A method and system for providing services in an object oriented system. The method and system are in the form of an interface reference framework of objects which create services in response to requests. Clients request services which are created in response to the requests. In response to the request the framework first develops a description of the service. The description is in the form of a stack of descriptions of services. From the stack descriptions the actual services are created by maker objects.

Abstract: An object-oriented framework is used to create multimedia application programs which route multimedia data from a multimedia source, such as a storage, to a multimedia presentation device for presentation. A variety of multimedia objects are defined in the storage, each of which has input and output ports, and a display is used to create the presentations by means of interactive graphics. Each of the objects generates its own graphic image and the application program is created by positioning the graphic images on the display and connecting them together with other connecting objects that generate graphic images, such as line segments. When the graphic images are connected, the underlying objects connect their input and output ports together to form the multimedia application program. The connecting objects can also perform data processing in the process of passing information from one object to another.

Abstract: Remote procedure call (RPC) objects are provided in both a client node and a server node of a client-server network for invoking and responding to service requests generated by calls to local service objects. Specifically, the RPC objects comprise a "caller" object which, once instantiated, accepts service requests from client objects. A service request made by calling a function in the local service object is automatically routed by the caller object to a local service program if the requests can be serviced locally, or to a remote server node if the appropriate service program is located on the remote node. The RPC objects also include a "dispatcher" object which is located at the remote service node and receives incoming service requests. The service requests are actually satisfied by means of service functions which are part of service objects in the server node, but these latter service functions are associated with the local service objects by means of a "dictionary" located in the dispatcher object.

Abstract: A data-driven global registry method for use to extend a framework in an object oriented programming (OOP) based computer system is provided. The method includes providing a new class defined in a shared class library which has data members and member functions related to a particular task. In addition, a new class attributes file which specifies attributes associated with the new class is generated. The new class attributes file is placed in a global registry configuration directory in a computer system such that a plurality of client applications can access the global registry configuration directory to determine if the new class has been installed in the class library. In an alternative embodiment, an object-based global registry method is provided. In addition, a storage device readable by a computer system for implementing either OOP-based global registry method and OOP-based global registries themselves are provided.

Abstract: A human oriented object programming system provides an interactive and dynamic process for debugging computer programs which facilitates the development of complex computer programs such as operating systems and large applications with graphic user interfaces (GUIs). The debugging system uses a database of information relating machine executable code to source code. The database is developed during the compilation process using an extensible object-oriented set of tools. The tools standardize the information developed during compilation into an information format which the debugging system can utilize to provide the user with a powerful source code view of the corresponding executing code.

Abstract: An object-oriented printing system includes objects that provide query, data transfer, and control methods. The inventive object-oriented printing system communicates with the remainder of the operating system by means of a standard interface such as a grafport and printer drivers are provided for each printer type within the operating system. Thus, an application not only need not worry about the particular printer/computer combination with which it is to operate, but also need not have a built in document formatting capability. The printing system includes objects that provide queries for device identification, optimized imaging, and printer status. Other objects are also provided for data transfer to bracket connections prior to sending and receiving information. Still other objects are provided for cancelling a print job, pausing a job, and clearing out a job. Finally, an object is also provided for supporting multiple streams of communication to an imaging task.

Abstract: A method and system for providing synchronization of the timing of various multimedia events, including a visual event is disclosed. Clock objects are defined in the storage and associated with an internal or external source of current time. The clock objects are able to be displayed on the display, but can be hidden once their linkages are defined. One or more multimedia objects representative of audio, visual or other multimedia events, including an audio object, are defined and linked to a particular clock object or clock objects. Then, a processor synchronizes the multimedia objects, including a visual object, with the associated clock object or objects. Finally, the various multimedia events are performed in synchronization with their associated clocks. The multimedia objects, including the visual object, may include external multimedia sources managed by the computer system.

Abstract: User interface objects are stored in a user interface object archive which is a database physically located in the shared library of an associated application program. In order to facilitate “localization”, or preparation of an application developed in one language for use in an “area” or a locale which uses another language, the user interface objects are stored in a hierarchical locale tree within the archive. All objects are stored in the base or root of the hierarchy, but only those objects which require a translation are stored in an area associated with a more specific locale. At runtime, a complete collection of objects is assembled by starting at the desired locale and proceeding up the hierarchy level-by-level. Translated objects at lower levels of the hierarchy “override” those at higher levels so that the most complete translations of each object are obtained during this search.