Abstract: The invention concerns a method for access to a transmission channel shared between several stations, characterised in that it includes iteratively: an operation (302) of estimating requirements of each of the stations for access to the transmission channel, an operation of determining groups (303 and 307) of stations taking into account the estimated access requirements of the stations, at least one of the groups of stations being said to be “collective”, an operation of allocating (308), to each of the groups, access rights each corresponding to an interval of time during which the stations which do not form part of the group are not authorised to access the transmission channel, and during which, if the group is collective, each station which it includes gains access to the transmission channel according to a contention method.

Abstract: A multi-port adapter and method for scheduling jobs at the adapter input/output ports. A plurality of queues are provided, each associated with one of the input/output ports. A processor arranges the jobs in each of the queues in a normal queued order for selection by the associated port. Upon selecting a next job for one of the ports, the processor determines the number of queued jobs of each of the queues for each of the other ports; and determines whether the number of queued jobs of each queue for the other ports is less than a threshold. If the number of jobs is less than the threshold, the processor selects the next job for the one port from the jobs in the queue for the one port identified as one that may be conducted in out of queue order, e.g., having attached heuristic information; else, selects the next job for the one port from the jobs in the queue for the one port on the normal queued basis.

Abstract: Disclosed is inhibiting process starvation in a multitasking operating system by providing a first type of scheduling event at periodic timer intervals, providing a second type of second scheduling event in response to a running processes voluntarily relinquishing the processor, and, in response to a scheduling event, replacing an old process with a new process only if the old process has run for more than a predetermined amount of time. The predetermined amount of time may be one half of the timer interval. The system described herein provides a small kernel that can run on a variety of hardware platforms, such as a PowerPC based Symmetrix adapter board used in a Symmetrix data storage device provided by EMC Corporation of Hopkinton, Mass. The core kernel code may be written for the general target platform, such as the PowerPC architecture.

Abstract: Methods and apparatus for locking an object using an efficient combination spinning and blocking process are disclosed. According to one aspect of the present invention, a method for acquiring ownership of an object in an object-based environment using a current thread includes determining when the object is owned by another thread, and locking the object when it is determined that the object is not owned by the another thread. A first spinning process, which is implemented when it is determined that the object is owned by the another thread, is arranged such that the current thread spins for up to a predetermined number of spin cycles associated with the current thread and the object. The predetermined number of spin cycles is determined using historical information, and is not based upon an overall system specification. When it is determined that the object has not been locked by the current thread during the first spinning process, a first blocking process is implemented.

Abstract: For use in time-limiting a request for information from a client to a resource, a timeout object, a method of operating the same and a real-time process control system employing the timeout object or the method. In one embodiment, the timeout object includes: (1) a client interface that receives, from the client, the request and a time-based parameter and (2) a resource interface that forwards the request to the resource and waits for the information an amount of time that is a function of the time-based parameter, the client interface: (2a) returning the information to the client if the timeout object receives the information within the amount of time and (2b) returning a timeout indicator to the client if the timeout object fails to receive the information within the amount of time.

Abstract: A basic message is derived from a message database file based on an identifier indicative of the sort of an event contained in event data under control of an event message forming program. A message component specific to the event contained in the event data is derived under control of an event data acquiring procedure. The event message forming program inserts the message component into the basic message to thereby complete a desired message. When the basic messages and the event data acquiring procedures are prepared in correspondence with the new sorts of events, these new sorts of events can be simply accepted in the conventional main structure.

Abstract: Systems, methods and computer program products are provided for sharing resources within an Extensible Markup Language (XML) document that defines a console (i.e., a graphical user interface or GUI) for managing a plurality of application programs and tasks associated therewith. Upon receiving a user request to perform a task associated with an application program managed by a console, resource containers at each scoping level within the XML document are searched for one or more resources required to perform the task. A search is initiated at the scoping level where a task to be performed is defined and proceeds in ascending order towards the root scoping level until the resource is located. When found, a clone of each located resource is generated. The task is then performed using the clone of the resource. The clone of the resource may be discarded after the task has been performed.

Abstract: Disclosed is a system, method, and program for implementing components of a user interface as an object. A user interface is implemented in a first user interface program object including elements compatible with a first user interface program. A standard application program interface (API) calling a first standard object to create a second standard object as an element of the first standard object is received. The standard API is a member of a set of standard APIs, such as the W3C APIs. A second user interface program API is generated to create a second user interface program object corresponding to the second standard object. The second user interface program object is embedded as an element in the first user interface program object.

Abstract: In a multi-processor system in which a plurality of threads to be simultaneously executed at a plurality of processors are stored as one thread set at a context area one-to-one corresponding to a thread set provided in a context save area on a main storage, the method of enabling a plurality of processors to start execution of threads simultaneously, in which exclusive arbitration is conducted during exception processing so as to temporarily allow only one processor among the plurality of processors constituting the multi-processor system to obtain kernel scheduler execution authority, and a processor obtaining kernel scheduler execution authority selects a thread set to be executed next and controls such that a plurality of threads in the selected thread set are executed simultaneously at a plurality of processors including its own processor.

Abstract: An access control method for drive units that can recognize drive units in specific groups, and drive units to which the method applies are disclosed. The method includes the steps of generating a device driver start request by a driver control program when the OS starts; sending a check command on the basis of the device driver start request; loading the specific device driver corresponding to the specific code contained in the response from the drive unit for the check command; and converting a predetermined host command by the specific device driver and sending the corresponding command to the drive unit under the specific device driver when the predetermined host command for the drive unit under the specific device driver is sent from the host device.

Abstract: A computer-system fixed-priority process scheduler that is supported by an operating system (OS) and establishes fixed priorities respectively corresponding to a plurality of processes to be scheduled. Further, the priorities can be changed by designation from the user processes. The process scheduler allocates a central processing unit (CPU) to executable ones of the processes in the descending order of the priorities thereof. Moreover, a user-level process scheduler is provided in a fixed-priority process scheduler space, namely, in a real-time class process scheduler space. The user-level process scheduler has a first priority of a real time class. Furthermore, the user-level process scheduler performs the scheduling of a group of other user processes, which have priorities lower than the first priority, and causes the group of such user processes to operate or run.

Abstract: A system and method for implementing mutual exclusion locks (mutexes) is provided. Mutexes of the present invention designate whether they are to be synchronized using fast nonatomic load/store sequences or, alternatively, expensive atomic hardware instructions. When a requesting thread requests a target mutex, the target mutex is synchronized using the method designated by the target mutex. In some embodiments, the designated synchronization method may be changed to the atomic method when the requesting thread is not the thread associated with the target mutex. In other embodiments, the designated synchronization method may be determined by a heuristic function. For example, the synchronization method may be changed to the atomic method when a mutex request counter, which penalizes thread changes, underflows.

Abstract: The present invention provides for a method and an apparatus for performing remote system administration upon a standalone computer system, using a controlling computer system. A remote communication sequence is started. The remote communication sequence is used to initiate a Hyper-Media Managed Object (HMMO) request to a computer destination address. Communications between the controlling computer system and the standalone computer system is established by decoding the computer destination address. A diagnostic software application program on the standalone computer system is initiated using the established communication between the controlling computer system and the standalone computer system.

Abstract: A method in a multi-processor computing system is disclosed. The method is an object-oriented method that allows a user to make associations between processes to be executed and available CPUs of the system. In particular, the method includes the displaying of the associations for a user to manipulate. Responses are accepted by the method from a user for creating logical groupings of the CPUs, hereinafter referred to as affinity groups. Next, an affinity mask is accepted from the user for each of the affinity groups, which affinity mask assigns available ones of the CPUs. After this a determination is made as to whether or not there are more CPUs to be assigned to the affinity groups, and if not; specific rules that make associations between the processes and the affinity groups are then accepted by the method from the user.

Abstract: A system and methods for managing Internet e-mail address changes, particularly useful for situations where subscribers change Internet service providers. A computer system manages a database of stored records correlating a first e-mail address of an intended recipient, e.g. an old e-mail address, to a second e-mail address, e.g. a new e-mail address of the intended recipient. A program module in the computer system is responsive to an Internet query for accessing the database to determine whether a second e-mail address of the intended recipient is stored in association with a first e-mail address. Another program module is operative for providing the second e-mail address as a response to the query. The query response is communicated to the sender or to the sender's ISP so that an undeliverable message can be resent to the new e-mail address. Also provided are security and authentication measures for ensuring that address change requests are valid and authentic.

Abstract: A method and apparatus for a process in a computer for processing a method that performs a function. A determination is made as to whether the method is to be executed normally when the method is loaded. Responsive to an absence of a determination that the method is a method to be executed normally, instructions native to the computer are associated with the method, wherein the instructions perform the function.

Abstract: A method and apparatus for prioritizing the use of multifunctional printing system's basic processing resources to allow a high priority job to gain immediate access to a shared resource. The printing system employs a controller with an improved job contention manager (JCM). A plurality of basic resources of the printing system are provided with a queue. One or more job services, at desired times, provides a first signal to the JCM to carry out a sub-job of a given job. The signal for each of the sub-jobs includes information about the respective sub-job and its priority. Responsive to the signal from the job service the JCM adds a corresponding basic resource sub-job to the queues of each basic resource which the added sub-job will require to perform the sub-job. The resources are reassigned by the JCM according to the priority of the added sub-job in the queues.

Abstract: A small footprint device can securely run multiple programs from unrelated vendors by the inclusion of a context barrier isolating the execution of the programs. The context barrier performs security checks to see that principal and object are within the same context or to see that a requested action is authorized for an object to be operated upon. Each program or set of programs runs in a separate context. Access from one program to another program across the context barrier can be achieved under controlled circumstances by using an entry point object.

Abstract: A method and system for establishing a priority order of threads executed within a multiprocessor data processing system are disclosed. The priority order of threads is maintained on a global queue within the data processing system and the queue is ordered by selecting a most favored runnable thread from among either a current thread, a favored thread, or an affinity thread. Once the thread is chosen, be it the current thread, the most favored thread, or the affinity thread, the chosen thread is removed from a run queue and then is run on the data processing system on a selected processor. An affinity thread pointer is updated to the thread being run to select the next affinity thread or the thread having the greatest affinity.

Abstract: A computer system which permits deterministic and preemptive scheduling of threads in a software application. In one embodiment, a scheduler is utilized to schedule the threads in a queue. Once the threads are scheduled, they are divided up into instruction slices each consisting of a predetermined number of instructions. The scheduler executes each instruction slice. An instruction counter is utilized to keep track of the number of instructions executed. The thread is permitted to run the instruction slice until the predetermined number of instructions has been executed. Alternatively, the thread stops if it is blocked while waiting for an input, for example. The next thread is then executed for the same number of instructions. This process permits for the efficient debugging of software which utilizes traditional cyclic debugging.