Abstract: Systems and methods for obtaining access to database files m a computing system. A method may include receiving a first call from a database management system requesting access to a database file. The method may further include transmitting a second call to an operating system interface requesting that a memory-mapped data expanse file be created. The method may also include receiving a first address representing the database file in response to successful mapping of the database file to the memory-mapped data expanse file located at the operating system interface.

Abstract: Systems and methods for obtaining access to database files in a computing system. A method may include receiving a first call from a database management system requesting access to a database file. The method may further include transmitting a second call to an operating system interface requesting that a memory-mapped data expanse file be created. The method may also include receiving a first address representing the database file in response to successful mapping of the database file to the memory-mapped data expanse file located at the operating system interface.

Abstract: Systems and methods for obtaining access to database files in a computing system. A method may include receiving a first call from a database management system requesting access to a database file. The method may further include transmitting a second call to an operating system interface requesting that a memory-mapped data expanse file be created. The method may also include receiving a first address representing the database file in response to successful mapping of the database file to the memory-mapped data expanse file located at the operating system interface.

Abstract: An apparatus for providing a computing environment in a computing system includes a first node, a second node, an operations server, and a communication link. The first node is capable of supporting a production computing environment and 5 has a first disk storage. The second node is capable of supporting a second operational computing environment, independent of the production computing environment and has a second disk storage. A method of switching a production computing environment from a first node, having a first disk storage, to a second node in the event of a failure on the first 15 node includes determining if the first node had a failure and if the first node had a failure: reassigning ownership of the partition definition to the second node; restoring communications configuration on the second node; and booting the second node from the first disk storage.

Abstract: An apparatus for providing a computing environment in a computing system includes a first node, a second node, an operations server, and a communication link. The first node is capable of supporting a production computing environment and has a first disk storage. The second node is capable of supporting a second operational computing environment, independent of the production computing environment and has a second disk storage. The operations server manages the first and second node and can switch the production computing environment from the first node to the second node. The communications link allows communication between the first node, the second node, and the operations server. The second node can take over the production computing environment from the first node upon a failure of the first node by providing the second node with access to the first disk storage and rebooting the second node from the first disk storage.

Abstract: Systems and methods for testing and validation of translated memory banks used in an emulated system are disclosed. One method includes translating one or more banks of non-native instructions into one or more banks of native instructions executable in a computing system having a native instruction set architecture. The one or more banks of non-native instructions define one or more tests of execution of a non-native instruction set architecture. The method also includes loading a memory with instructions and data defined according to the non-native instruction set architecture and addressed by the one or more tests, and triggering, by an emulator, execution of the translated one or more banks of native instructions. The method further includes, upon detection of an error during execution of the translated one or more banks of native instructions, identifying an error in execution of the non-native instruction set architecture by the computing system.

Abstract: A computing system and method of executing a software program and translation of instructions for an emulated computing environment. The computing system includes a programmable circuit capable of executing native instructions of a first instruction set architecture and incapable of executing non-native instructions of a second instruction set architecture. The emulator operates within an interface layer and translates non-native applications hosted within an emulated operating system for execution. The computing system includes translated memory banks defined at least in part by the emulated operating system and capable of native execution on the programmable circuit, where the emulated operating system is incapable of execution on the programmable circuit.

Abstract: A method of and apparatus for efficiently providing video on demand services to a cable television subscriber. The provider system consists of two major subsystems. The first subsystem, called a video server, streams video to video on demand subscribers through the cable television network. The second subsystem, called the transaction server, performs virtually all remaining provider functions including, security, accounting, storage and spooling of video data, etc. The video server is preferably uses a Unisys CMP memory platform into which the transaction server spools requested video programs. One or more industry standard processors operating under a standard operating system stream the video data from the memory platform to the subscriber.

Abstract: An apparatus for providing a computing environment in a computing system includes a first node, a second node, an operations server, and a communication link. The first node is capable of supporting a production computing environment and has a first disk storage. The second node is capable of supporting a second operational computing environment, independent of the production computing environment and has a second disk storage. The operations server manages the first and second node and can switch the production computing environment from the first node to the second node. The communications link allows communication between the first node, the second node, and the operations server. The second node can take over the production computing environment from the first node upon a failure of the first node by providing the second node with access to the first disk storage and rebooting the second node from the first disk storage.

Abstract: A method of handing off connection requests from a file server to other receivers on a network includes receiving a connection request from a receiver, checking to see if the requested content is currently being provided by the file server to another receiver, and, if so, handing off the request to the another receiver.

Abstract: A method of and apparatus for efficiently providing video on demand services to a cable television subscriber. The provider system consists of two major subsystems. The first subsystem, called a video server, streams video to video on demand subscribers through the cable television network. The second subsystem, called the transaction server, performs virtually all remaining provider functions including, security, accounting, storage and spooling of video data, etc. The transaction server preferably uses a large scale mainframe computer. The video server subsystem may be a partitioned portion of same large scale mainframe computer.

Abstract: A method of and apparatus for efficiently communicating between a provider of video on demand services and a cable television subscriber. The communication is implemented using a message protocol specifically optimized to communicate between a multimedia application server and a set top subscriber box. The message format includes unique identifiers for addressing and synchronization to permit the multimedia application server to manage the communication process.

Abstract: Streaming media servers are used to provide data streams of streaming media data to network devices across a communications network. In order to allow the servers to scale its processing as the number of data streams increases, these servers use a delay timer determination module for determining when a given CPU is to transfer its streaming media data corresponding to its group of data streams, a CPU wake up module for initiating an acceleration process for each CPU upon receipt of a signal from the delay timer determination module, and a plurality of CPU processing modules for transferring streaming media data corresponding to its group of data streams.

Abstract: A method of and apparatus for efficiently managing video programming services by a provider of video on demand services in response to requests from cable television subscribers. The system is controlled by a multimedia application server. Upon receipt of a request, the multimedia application server searches for the most appropriate means of satisfying the request. If the requested program is already being provided, the streaming occurs from the same video server, if capacity is available. If the program already exists in streamable form, it is streamed from that location. If the requested program must be transferred to video server memory, the available space is found to accommodate the transfer or existing programming is swapped out.

Abstract: A system and method for adding a queue entry containing message data to a queue shared by communicating, sequential processes includes an enqueue instruction. The enqueue instruction attaches a queue entry to either the tail or the head of the shared queue, as specified by an application programmer. Execution of the enqueue instruction includes blocking access to the queue by other processes, updating queue linkages, activating processes waiting on entries being made to the queue, monitoring interrupts, and validating the appropriate queue data structures. If desired, in lieu of adding a queue entry containing message data to the queue, the enqueue instruction inserts an event indicator into the shared queue structure, thereby providing synchronization capabilities between communicating processes.

Abstract: A system and method for interprocess communication between concurrently executing, cooperating sequential processes in a digital computer system uses a shared memory queue as a mechanism for message passing and process synchronization. Data to be transferred from a sending process to a receiving process is stored in a queue entry which is visible in the virtual address space of the first process. The queue entry is added to a queue by the sending process directing the processor to execute an enqueue instruction. The receiving process removes the queue entry from the queue by directing the processor to execute a dequeue instruction. The receiving process then has direct access and visibility to the contents of the queue entry without having to copy the data into its virtual address space. Instead of sending data in a queue entry, a sending process may send an event indicator and no data.

Abstract: An Internet checksum for use by TCP/IP is generated in a single macro-instruction called a Block Add Octets instruction. Extraneous overhead of macro-instruction looping and bit masking is eliminated by combining checksum operations into a single macro-instruction using a block add approach. The programmer specifies the address in memory and the number of double-words of message data to be added together within a single instance of the Block Add Octets instruction so that looping and jump/branch instructions are not needed. The Block Add Octets instruction fetches all octets (8-bit data segments) contained in full double words from memory and adds them into the checksum. The method handles partial double words of data, full double words, and odd numbers of double words, whereby a double word consists of four octets. The checksum is calculated using one's complement arithmetic rather than two's complement, thereby increasing the speed of checksum calculation because the "end around carry" is eliminated.

Abstract: A network input/output processing system for sending and receiving messages between a large scale computer system and associated communications networks. Executive operating system services provide access to a control table, an input queue, and an output queue stored in the computer system's main memory. A network input/output processor responds to requests by application programs, through a communications program, for receiving input from and sending output to a network, concurrently with requests to communicate with directly attached peripheral devices such as disk drives, tape drives, and printers. The network input/output processor receives initialization, reset, and termination requests via the control table. Requests to receive input are received from the input queue. Input data is stored into buffers as directed by the input request. Requests to send output are received from the output queue. Output data is read from the buffers as directed by the output request.

Abstract: A system and method for removing a queue entry containing message data from a queue shared by communicating, sequential processes includes dequeue (DEQ) and dequeue or wait (DEQW) instructions. The dequeue instruction removes a queue entry from the head of the shared queue, thereby providing access to the message data contained in the queue entry to the dequeuing process. The dequeue or wait instruction removes a queue entry from the shared queue if there is one, otherwise it suspends the execution of the dequeuing process until an entry is enqueued to the queue. If an event is selected by the dequeuing process, the dequeuing process is suspended until notification of the event is detected in the shared queue. Execution of the dequeue and dequeue or wait instructions include blocking access to the queue by other processes, updating queue linkages, deactivating processes waiting on entries or events being made to the queue, monitoring interrupts, and validating the appropriate queue data structures.

Abstract: A system and method for interprocess communication between concurrently executing, cooperating sequential processes in a digital computer system uses a shared memory queue as a mechanism for message passing and process synchronization. Data to be transferred from a sending process to a receiving process is stored in a queue entry on the shared memory queue. Hierarchical queuing allows a sending process to collect multiple message segments as entries in a local sub-queue, which is enqueued as a single entity to the shared memory queue when all message segments are present. The receiving process dequeues the sub-queue in one operation, thereby increasing the efficiency of message transfer while preventing the erroneous dequeuing of message segments when multiple receiving processes are waiting on the same shared memory queue. In this manner, the logical maximum size of a message being passed between processes is expanded.