Abstract: An Input/output (I/O) measurement block facility is provided that creates subchannel measurement blocks (comprising device busy values) related to performance of an I/O operation of a subchannel, wherein a device busy time value is a sum of time intervals when the subchannel is device busy during an attempt to initiate any one of a start function or a resume function at the subchannel.

Abstract: A method of garbage collection of shared data in a system heap within a data processing system, the method comprising the steps of: (a) determining if the contents of the system heap has reached a predetermined threshold, the system heap storing shared objects which are shared amongst a plurality of processes running in a data processing system; (b) in a table identifying each of the plurality of processes with a status field, setting the status field of a process which has carried out determining step (a) to a mark initiator value; (c) triggering remaining processes to mark all objects in the system heap that each process is currently using; (d) determining that each of the remaining processes has completed the marking, at step (c); (e) releasing any unmarked objects in the system heap to an object pool.

Abstract: I/O measurement data for channels attached to logical control unit queues is obtained related to a plurality of logical control unit queues. A store secondary queue measurement data instruction specifies a range of queues for which extended secondary measurement blocks derived from the I/O measurement data are stored at a memory address specified by the store secondary queue measurement data instruction.

Abstract: I/O measurement data associated with the performance of an I/O operation process is gathered during the I/O process. The I/O measurement data is saved in an IRB memory location specified by a test subchannel instruction. An I/O interrupt signals the completion of the I/O operation process.

Abstract: This invention relates to memory management in a virtual machine or operating system and in particular to object creation and garbage collection. There is described a method and system of managing memory in a multi-threaded processing environment such as a java virtual machine comprising: creating an object in a thread heap; associating a status with the object and setting the status as local; using write barriers to change the status to global if the object is assigned to a static variable or if the object is assigned to a field in a global object; changing the status of all objects referenced by that object to global; and performing garbage collection by deleting from the thread heap, when memory space in the thread heap is required, one or more local objects which can not be traced to the thread stack.

Abstract: There is described a method of accurately scanning the C stack. One technique for solving these problems is to indirectly reference objects using handles however the some JVMs have removed handles to gain a performance improvement. The embodiment describes a solution in which 32 bit quantities are known to be object references by means of some side information. This avoids the problem of integer values masquerading as references causing objects to be needlessly retained. It also allows employment of a compacting collector which is allowed to move objects even if they are referenced from the stacks. Currently the compactor is prevented from moving such objects leading to reduced compaction efficiency.

Abstract: This invention relates to memory management in a virtual machine or operating system and in particular to object creation and garbage collection. There is described a method and system of managing memory in a multi-threaded processing environment such as a java virtual machine comprising: creating an object in a thread heap; associating a status with the object and setting the status as local; using write barriers to change the status to global if the object is assigned to a static variable or if the object is assigned to a field in any other object; and performing garbage collection by deleting from the thread heap, when memory space in the thread heap is required, one or more local objects which can not be traced to the thread stack.

Abstract: A computer system provides an object-based environment and includes storage. At least a portion of the storage is logically divided into two or more heaps in which objects can be stored. Each heap is subdivided into slices of memory. The system includes a two-level lookup structure for determining whether a given storage address corresponds to a particular heap. The lookup substructure involves a first level having one or more lookup substructures, each corresponding to a unit of memory representing a predetermined number of slices. The substructure indicates for each of these slices the particular heap, if any, that the slice belongs to. The two-level lookup structure further involves a second level for determining for a given memory address the first level lookup substructure that includes the slice containing that address.

Abstract: A computer-implemented method for reducing a computing overhead associated with objects that are local to a particular thread and can be accessed solely by that thread. Dynamically during run-time, an object is determined to be local to a particular thread and can be accessed solely by that thread, whereby a computing overhead associated with that object may be reduced. Likewise, cache locality may be optimized in respect of objects that are determined to be global so as to avoid putting them in the same cache line, whilst thread-local objects are preferably stored in a cache line associated with that thread.

Abstract: A method is provided for managing memory resources in a shared memory system. A point is identified (10) at which memory usage will be constrained. An object pertaining to an active user of the system is identified (20), and further objects related to this object are also found (30). A user memory footprint is then determined (40) from the footprints of the identified objects. Different constraint options are identified (50) and one of these is used to constrain (60) the user memory footprint. In this way the memory used by individual users may be tracked and constrained without having to place all the work from users into separate JVMs. Therefore the ‘bursty’ nature of memory consumption by multiple users can be summed to result in a JVM which exhibits much less bursty memory requirements and allows individual users to have relatively relaxed constraints.

Abstract: A Channel Association method and apparatus for a wireless Network increases data throughput by intelligently associating clients to channels. Data rates are assigned to channels and clients with a similar data rate are associated to the same channel. The association is based on the client's distance from a host, the received power of each client and the performance of the client at the host.

Abstract: A video teleconferencing and multimedia presentation system is provided. The system is integrated and network-ready to facilitate ease of set-up and operation, and also utilizes IP and/or wireless networking to provide advanced features and functionality, such as remote access and control and the ability to perform secure archiving and retrieval of recorded video and audio data. The system further utilizes a unique peer-to-peer conference network solution in order to address the bandwidth limitations that plague conventional systems and allow enhanced viewing of high-bandwidth applications.

Abstract: A control server, or similar central processor, manages the distribution of data (including audio and video), voice, and control signals among a plurality of devices connected via a wired and/or wireless communications network. The devices include audio/visual devices (such as, televisions, monitors, PDAs, notepads, notebooks, MP3, portable stereo, etc.) as well as household appliances (such as, lighting, ovens, alarm clocks, etc.). The control server supports video/audio serving, telephony, messaging, file sharing, internetworking, and security. A portable controller allows a user to access and control the network devices from any location within a controlled residential and/or non-residential environment, including its surrounding areas. The controllers are enhanced to support location-awareness and user-awareness functionality.

Abstract: A method of garbage collection of shared data in a system heap within a data processing system, the method comprising the steps of: (a) determining if the contents of the system heap has reached a predetermined threshold, the system heap storing shared objects which are shared amongst a plurality of processes running in a data processing system; (b) in a table identifying each of the plurality of processes with a status field, setting the status field of a process which has carried out determining step (a) to a mark initiator value; (c) triggering remaining processes to mark all objects in the system heap that each process is currently using; (d) determining that each of the remaining processes has completed the marking, at step (c); (e) releasing any unmarked objects in the system heap to an object pool.

Abstract: The invention relates to a method of operating a computer system supporting multiple processes having potentially different priorities. The system provides a wait-notify mechanism, whereby a first process can be suspended pending notification from a second process. The mechanism is controlled via a predetermined resource which-must be-owned by the first process when suspension is initiated, and the second process at the time of notification. During the suspension of the first process, the priority of a process that acquires ownership of said predetermined resource is increased, typically to a level equal to that of the first process. This ensures that the first process does not wait an unduly long time to be notified for resumption.

Abstract: A computer system provides an object-based virtual machine environment for running successive applications. The computer system includes storage, at least a portion of which is logically divided into two or more heaps in which objects can be stored. A first heap is reset between successive applications, and a second heap persists from one application to the next. A card table is provided which comprises multiple cards, each corresponding to a region of said storage. Each card in the card table is set to null when the first heap is reset between successive applications. A card is marked whenever an object in its corresponding storage region is created or updated. It is then possible to detect potential references from the second heap to the first heap at reset by scanning the cards in the card table corresponding to the second heap, and detecting any cards which have been marked.

Abstract: A computer system provides an object-based environment and includes storage. At least a portion of the storage is logically divided into two or more heaps in which objects can be stored. Each heap is subdivided into slices of memory. The system includes a two-level lookup structure for determining whether a given storage address corresponds to a particular heap. The lookup substructure involves a first level having one or more lookup substructures, each corresponding to a unit of memory representing a predetermined number of slices. The substructure indicates for each of these slices the particular heap, if any, that the slice belongs to. The two-level lookup structure further involves a second level for determining for a given memory address the first level lookup substructure that includes the slice containing that address.

Abstract: A semantic network is described in which data is stored in data storage areas at nodes of the network, there being a root node from which all other nodes depend, in a branched structure, and in which data stored at each node includes relationship information about related nodes other than nodes linked by a branch from said node. The relationship information includes a token identifying the type of relationship. The other node in a relationship may be a virtual node, which does not actually exist, but whose data content is stored within the relationship information.

Abstract: The present invention relates to the solution of sets of linear equations by microprocessors. In particular, when the process for solving a set of linear equations can be resolved into a set of tasks, each of which can be processed by a processing element in a multiprocessor computer, embodiments of the present invention determine the scheduling of the processing of respective tasks by each processing element. In an exemplary embodiment, the order in which each processing element should process those tasks distributed to it is determined by computing a cost metric indicative of the amount of time required to process the task and a completion time metric, indicative of the amount of time required to process all remaining tasks after that task is completed. Consequently, the tasks distributed to a given processing element are processed in an order based on the completion time metrics computed for the respective tasks.