Abstract: Transmitting data chunks in a computer system having different computing ring levels. A data chunk is accepted by a relatively low priority ring module from a relatively high priority ring source. The address of the data chunk is translated into the address space of the low priority ring module. The low priority ring module is notified of the availability of the data chunk.

Abstract: An improved method and apparatus for embedding a real-time multi-tasking kernel in a non-real-time operating system is disclosed. Through encapsulating a real-time kernel into the interrupt handling environment of a non-real-time operating system, such as Windows.RTM., the method of the present invention allows for an entire real-time environment to be supported within the operating system. The scheduler of the real-time kernel supports multiple threads of execution all running at higher priority than the application tasks. By using synchronization mechanisms of the operating system, e.g. VxD events in enhanced mode Windows.RTM., the real-time tasks are able to make use of system services of the operating system. Real-time tasks not requiring system services execute more quickly from interrupt mode. Real-time tasks requiring system services execute partially from interrupt mode and partially from event mode.

Abstract: A cross-domain data transfer technique is disclosed in which page remapping operations are eliminated in situations where physical memory addresses can be passed across domains. By passing physical memory addresses across domains instead of virtual memory addresses, the page remapping operations necessarily associated with passing virtual memory addresses across domains can be avoided in many cases. With the receipt of data across domains, page remapping operations are able to be deferred until the data is received in a domain that needs to touch the data. In certain cases, the transfer of data can be completed without ever having to map in the data to the receiving domain's address space. With the transmission of data across domains, where possible the pages are borrowed in their physical form. The invention can be embodied in many ways, including system, apparatus or method forms.

Abstract: A conversion methodology utilizes increasing microprocessor performance characteristics and System Management Mode ("SMM") to provide transparent support of hardware components that include features unsupported by executing application and operating system programs. In one embodiment, a PC system includes code that supports only conventional but unavailable communication interfaces. However, the PC system is equipped with a universal serial bus ("USB") controller. Although the USB controller is unsupported by the executing code by the application and operating system programs, the conversion methodology utilizes system management mode to facilitate transparent support for the USB controller. In SMM, a CPU executes SMM code independently of the operating system(s). The conversion methodology causes entry of SMM upon any I/O operation intended for the supported but unavailable conventional communication interfaces.

Abstract: A method for a computer compiler for an object-oriented programming language for implementing virtual functions and virtual base classes is provided. In preferred embodiments of the present invention, the data structure layout of an object includes a virtual function table pointer, a virtual base table pointer, occurrences of each non-virtual base class, the data members of the class, and occurrences of each virtual base class. If a class introduces a virtual function member and the class has a non-virtual base class with a virtual function table pointer, then the class shares the virtual function table pointer of the non-virtual base class that is first visited in a depth-first, left-to-right traversal of the inheritance tree. In preferred embodiments of the present invention, each instance of a given class shares a set of virtual function tables and virtual base tables for that class.

Abstract: A method and apparatus for providing per-instance data memory in a dynamic link library (DLL) linked to multiple tasks or to multiple instances of one task in the context of an operating system that does not provide such a feature. The invention includes providing a task switch enhancer DLL that allocates and manages a memory segment to store per-instance data of a DLL for a task as a substitute for an original per-instance data segment for that task.

Abstract: A metadisk driver functionally intermediate a computer operating system and one or more metadrivers and underlying layered drivers provides a driver rename/exchange function which does not depend on any particular driver having knowledge of the private data structures of any of the other drivers. The rename/exchange technique implemented thereby may be conducted while the underlying devices are on-line and comprise atomic operations which are, therefore, recoverable inasmuch as the operation will have either been completed or will not be committed in the event of any interruption.

Abstract: A method and system for coordinating software extensions by utilizing a central management system. One or more extensions register with the central manager, the extensions being capable of providing extended functionality to one or more lower level functions. As calls are made from an application program to a lower level function, the calls are intercepted at the central manager. Each of the appropriately registered extensions is then notified of the existence of the call, thereby allowing the extensions to provide extended functionality thereto.The call is then passed by the manager to the lower level function, which returns a result of the call to the manager. The extensions are then notified of the result of the call. This enables the registered extensions to modify the result of the call to provide its extended functionality.